tools/lib/bpf/libbpf.c

   1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
   2
   3 /*
   4  * Common eBPF ELF object loading operations.
   5  *
   6  * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
   7  * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
   8  * Copyright (C) 2015 Huawei Inc.
   9  * Copyright (C) 2017 Nicira, Inc.
  10  * Copyright (C) 2019 Isovalent, Inc.
  11  */
  12
  13 #ifndef _GNU_SOURCE
  14 #define _GNU_SOURCE
  15 #endif
  16 #include <stdlib.h>
  17 #include <stdio.h>
  18 #include <stdarg.h>
  19 #include <libgen.h>
  20 #include <inttypes.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include <fcntl.h>
  24 #include <errno.h>
  25 #include <asm/unistd.h>
  26 #include <linux/err.h>
  27 #include <linux/kernel.h>
  28 #include <linux/bpf.h>
  29 #include <linux/btf.h>
  30 #include <linux/filter.h>
  31 #include <linux/list.h>
  32 #include <linux/limits.h>
  33 #include <linux/perf_event.h>
  34 #include <linux/ring_buffer.h>
  35 #include <sys/stat.h>
  36 #include <sys/types.h>
  37 #include <sys/vfs.h>
  38 #include <tools/libc_compat.h>
  39 #include <libelf.h>
  40 #include <gelf.h>
  41
  42 #include "libbpf.h"
  43 #include "bpf.h"
  44 #include "btf.h"
  45 #include "str_error.h"
  46 #include "libbpf_internal.h"
  47
  48 #ifndef EM_BPF
  49 #define EM_BPF 247
  50 #endif
  51
  52 #ifndef BPF_FS_MAGIC
  53 #define BPF_FS_MAGIC            0xcafe4a11
  54 #endif
  55
  56 /* vsprintf() in __base_pr() uses nonliteral format string. It may break
  57  * compilation if user enables corresponding warning. Disable it explicitly.
  58  */
  59 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
  60
  61 #define __printf(a, b)  __attribute__((format(printf, a, b)))
  62
  63 static int __base_pr(enum libbpf_print_level level, const char *format,
  64                      va_list args)
  65 {
  66         if (level == LIBBPF_DEBUG)
  67                 return 0;
  68
  69         return vfprintf(stderr, format, args);
  70 }
  71
  72 static libbpf_print_fn_t __libbpf_pr = __base_pr;
  73
  74 void libbpf_set_print(libbpf_print_fn_t fn)
  75 {
  76         __libbpf_pr = fn;
  77 }
  78
  79 __printf(2, 3)
  80 void libbpf_print(enum libbpf_print_level level, const char *format, ...)
  81 {
  82         va_list args;
  83
  84         if (!__libbpf_pr)
  85                 return;
  86
  87         va_start(args, format);
  88         __libbpf_pr(level, format, args);
  89         va_end(args);
  90 }
  91
  92 #define STRERR_BUFSIZE  128
  93
  94 #define CHECK_ERR(action, err, out) do {        \
  95         err = action;                   \
  96         if (err)                        \
  97                 goto out;               \
  98 } while(0)
  99
 100
 101 /* Copied from tools/perf/util/util.h */
 102 #ifndef zfree
 103 # define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
 104 #endif
 105
 106 #ifndef zclose
 107 # define zclose(fd) ({                  \
 108         int ___err = 0;                 \
 109         if ((fd) >= 0)                  \
 110                 ___err = close((fd));   \
 111         fd = -1;                        \
 112         ___err; })
 113 #endif
 114
 115 #ifdef HAVE_LIBELF_MMAP_SUPPORT
 116 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP
 117 #else
 118 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
 119 #endif
 120
 121 static inline __u64 ptr_to_u64(const void *ptr)
 122 {
 123         return (__u64) (unsigned long) ptr;
 124 }
 125
 126 struct bpf_capabilities {
 127         /* v4.14: kernel support for program & map names. */
 128         __u32 name:1;
 129         /* v5.2: kernel support for global data sections. */
 130         __u32 global_data:1;
 131         /* BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO support */
 132         __u32 btf_func:1;
 133         /* BTF_KIND_VAR and BTF_KIND_DATASEC support */
 134         __u32 btf_datasec:1;
 135 };
 136
 137 /*
 138  * bpf_prog should be a better name but it has been used in
 139  * linux/filter.h.
 140  */
 141 struct bpf_program {
 142         /* Index in elf obj file, for relocation use. */
 143         int idx;
 144         char *name;
 145         int prog_ifindex;
 146         char *section_name;
 147         /* section_name with / replaced by _; makes recursive pinning
 148          * in bpf_object__pin_programs easier
 149          */
 150         char *pin_name;
 151         struct bpf_insn *insns;
 152         size_t insns_cnt, main_prog_cnt;
 153         enum bpf_prog_type type;
 154
 155         struct reloc_desc {
 156                 enum {
 157                         RELO_LD64,
 158                         RELO_CALL,
 159                         RELO_DATA,
 160                 } type;
 161                 int insn_idx;
 162                 union {
 163                         int map_idx;
 164                         int text_off;
 165                 };
 166         } *reloc_desc;
 167         int nr_reloc;
 168         int log_level;
 169
 170         struct {
 171                 int nr;
 172                 int *fds;
 173         } instances;
 174         bpf_program_prep_t preprocessor;
 175
 176         struct bpf_object *obj;
 177         void *priv;
 178         bpf_program_clear_priv_t clear_priv;
 179
 180         enum bpf_attach_type expected_attach_type;
 181         int btf_fd;
 182         void *func_info;
 183         __u32 func_info_rec_size;
 184         __u32 func_info_cnt;
 185
 186         struct bpf_capabilities *caps;
 187
 188         void *line_info;
 189         __u32 line_info_rec_size;
 190         __u32 line_info_cnt;
 191         __u32 prog_flags;
 192 };
 193
 194 enum libbpf_map_type {
 195         LIBBPF_MAP_UNSPEC,
 196         LIBBPF_MAP_DATA,
 197         LIBBPF_MAP_BSS,
 198         LIBBPF_MAP_RODATA,
 199 };
 200
 201 static const char * const libbpf_type_to_btf_name[] = {
 202         [LIBBPF_MAP_DATA]       = ".data",
 203         [LIBBPF_MAP_BSS]        = ".bss",
 204         [LIBBPF_MAP_RODATA]     = ".rodata",
 205 };
 206
 207 struct bpf_map {
 208         int fd;
 209         char *name;
 210         size_t offset;
 211         int map_ifindex;
 212         int inner_map_fd;
 213         struct bpf_map_def def;
 214         __u32 btf_key_type_id;
 215         __u32 btf_value_type_id;
 216         void *priv;
 217         bpf_map_clear_priv_t clear_priv;
 218         enum libbpf_map_type libbpf_type;
 219 };
 220
 221 struct bpf_secdata {
 222         void *rodata;
 223         void *data;
 224 };
 225
 226 static LIST_HEAD(bpf_objects_list);
 227
 228 struct bpf_object {
 229         char name[BPF_OBJ_NAME_LEN];
 230         char license[64];
 231         __u32 kern_version;
 232
 233         struct bpf_program *programs;
 234         size_t nr_programs;
 235         struct bpf_map *maps;
 236         size_t nr_maps;
 237         struct bpf_secdata sections;
 238
 239         bool loaded;
 240         bool has_pseudo_calls;
 241
 242         /*
 243          * Information when doing elf related work. Only valid if fd
 244          * is valid.
 245          */
 246         struct {
 247                 int fd;
 248                 void *obj_buf;
 249                 size_t obj_buf_sz;
 250                 Elf *elf;
 251                 GElf_Ehdr ehdr;
 252                 Elf_Data *symbols;
 253                 Elf_Data *data;
 254                 Elf_Data *rodata;
 255                 Elf_Data *bss;
 256                 size_t strtabidx;
 257                 struct {
 258                         GElf_Shdr shdr;
 259                         Elf_Data *data;
 260                 } *reloc;
 261                 int nr_reloc;
 262                 int maps_shndx;
 263                 int text_shndx;
 264                 int data_shndx;
 265                 int rodata_shndx;
 266                 int bss_shndx;
 267         } efile;
 268         /*
 269          * All loaded bpf_object is linked in a list, which is
 270          * hidden to caller. bpf_objects__<func> handlers deal with
 271          * all objects.
 272          */
 273         struct list_head list;
 274
 275         struct btf *btf;
 276         struct btf_ext *btf_ext;
 277
 278         void *priv;
 279         bpf_object_clear_priv_t clear_priv;
 280
 281         struct bpf_capabilities caps;
 282
 283         char path[];
 284 };
 285 #define obj_elf_valid(o)        ((o)->efile.elf)
 286
 287 void bpf_program__unload(struct bpf_program *prog)
 288 {
 289         int i;
 290
 291         if (!prog)
 292                 return;
 293
 294         /*
 295          * If the object is opened but the program was never loaded,
 296          * it is possible that prog->instances.nr == -1.
 297          */
 298         if (prog->instances.nr > 0) {
 299                 for (i = 0; i < prog->instances.nr; i++)
 300                         zclose(prog->instances.fds[i]);
 301         } else if (prog->instances.nr != -1) {
 302                 pr_warning("Internal error: instances.nr is %d\n",
 303                            prog->instances.nr);
 304         }
 305
 306         prog->instances.nr = -1;
 307         zfree(&prog->instances.fds);
 308
 309         zclose(prog->btf_fd);
 310         zfree(&prog->func_info);
 311         zfree(&prog->line_info);
 312 }
 313
 314 static void bpf_program__exit(struct bpf_program *prog)
 315 {
 316         if (!prog)
 317                 return;
 318
 319         if (prog->clear_priv)
 320                 prog->clear_priv(prog, prog->priv);
 321
 322         prog->priv = NULL;
 323         prog->clear_priv = NULL;
 324
 325         bpf_program__unload(prog);
 326         zfree(&prog->name);
 327         zfree(&prog->section_name);
 328         zfree(&prog->pin_name);
 329         zfree(&prog->insns);
 330         zfree(&prog->reloc_desc);
 331
 332         prog->nr_reloc = 0;
 333         prog->insns_cnt = 0;
 334         prog->idx = -1;
 335 }
 336
 337 static char *__bpf_program__pin_name(struct bpf_program *prog)
 338 {
 339         char *name, *p;
 340
 341         name = p = strdup(prog->section_name);
 342         while ((p = strchr(p, '/')))
 343                 *p = '_';
 344
 345         return name;
 346 }
 347
 348 static int
 349 bpf_program__init(void *data, size_t size, char *section_name, int idx,
 350                   struct bpf_program *prog)
 351 {
 352         const size_t bpf_insn_sz = sizeof(struct bpf_insn);
 353
 354         if (size == 0 || size % bpf_insn_sz) {
 355                 pr_warning("corrupted section '%s', size: %zu\n",
 356                            section_name, size);
 357                 return -EINVAL;
 358         }
 359
 360         memset(prog, 0, sizeof(*prog));
 361
 362         prog->section_name = strdup(section_name);
 363         if (!prog->section_name) {
 364                 pr_warning("failed to alloc name for prog under section(%d) %s\n",
 365                            idx, section_name);
 366                 goto errout;
 367         }
 368
 369         prog->pin_name = __bpf_program__pin_name(prog);
 370         if (!prog->pin_name) {
 371                 pr_warning("failed to alloc pin name for prog under section(%d) %s\n",
 372                            idx, section_name);
 373                 goto errout;
 374         }
 375
 376         prog->insns = malloc(size);
 377         if (!prog->insns) {
 378                 pr_warning("failed to alloc insns for prog under section %s\n",
 379                            section_name);
 380                 goto errout;
 381         }
 382         prog->insns_cnt = size / bpf_insn_sz;
 383         memcpy(prog->insns, data, size);
 384         prog->idx = idx;
 385         prog->instances.fds = NULL;
 386         prog->instances.nr = -1;
 387         prog->type = BPF_PROG_TYPE_UNSPEC;
 388         prog->btf_fd = -1;
 389
 390         return 0;
 391 errout:
 392         bpf_program__exit(prog);
 393         return -ENOMEM;
 394 }
 395
 396 static int
 397 bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
 398                         char *section_name, int idx)
 399 {
 400         struct bpf_program prog, *progs;
 401         int nr_progs, err;
 402
 403         err = bpf_program__init(data, size, section_name, idx, &prog);
 404         if (err)
 405                 return err;
 406
 407         prog.caps = &obj->caps;
 408         progs = obj->programs;
 409         nr_progs = obj->nr_programs;
 410
 411         progs = reallocarray(progs, nr_progs + 1, sizeof(progs[0]));
 412         if (!progs) {
 413                 /*
 414                  * In this case the original obj->programs
 415                  * is still valid, so don't need special treat for
 416                  * bpf_close_object().
 417                  */
 418                 pr_warning("failed to alloc a new program under section '%s'\n",
 419                            section_name);
 420                 bpf_program__exit(&prog);
 421                 return -ENOMEM;
 422         }
 423
 424         pr_debug("found program %s\n", prog.section_name);
 425         obj->programs = progs;
 426         obj->nr_programs = nr_progs + 1;
 427         prog.obj = obj;
 428         progs[nr_progs] = prog;
 429         return 0;
 430 }
 431
 432 static int
 433 bpf_object__init_prog_names(struct bpf_object *obj)
 434 {
 435         Elf_Data *symbols = obj->efile.symbols;
 436         struct bpf_program *prog;
 437         size_t pi, si;
 438
 439         for (pi = 0; pi < obj->nr_programs; pi++) {
 440                 const char *name = NULL;
 441
 442                 prog = &obj->programs[pi];
 443
 444                 for (si = 0; si < symbols->d_size / sizeof(GElf_Sym) && !name;
 445                      si++) {
 446                         GElf_Sym sym;
 447
 448                         if (!gelf_getsym(symbols, si, &sym))
 449                                 continue;
 450                         if (sym.st_shndx != prog->idx)
 451                                 continue;
 452                         if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL)
 453                                 continue;
 454
 455                         name = elf_strptr(obj->efile.elf,
 456                                           obj->efile.strtabidx,
 457                                           sym.st_name);
 458                         if (!name) {
 459                                 pr_warning("failed to get sym name string for prog %s\n",
 460                                            prog->section_name);
 461                                 return -LIBBPF_ERRNO__LIBELF;
 462                         }
 463                 }
 464
 465                 if (!name && prog->idx == obj->efile.text_shndx)
 466                         name = ".text";
 467
 468                 if (!name) {
 469                         pr_warning("failed to find sym for prog %s\n",
 470                                    prog->section_name);
 471                         return -EINVAL;
 472                 }
 473
 474                 prog->name = strdup(name);
 475                 if (!prog->name) {
 476                         pr_warning("failed to allocate memory for prog sym %s\n",
 477                                    name);
 478                         return -ENOMEM;
 479                 }
 480         }
 481
 482         return 0;
 483 }
 484
 485 static struct bpf_object *bpf_object__new(const char *path,
 486                                           void *obj_buf,
 487                                           size_t obj_buf_sz)
 488 {
 489         struct bpf_object *obj;
 490         char *end;
 491
 492         obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
 493         if (!obj) {
 494                 pr_warning("alloc memory failed for %s\n", path);
 495                 return ERR_PTR(-ENOMEM);
 496         }
 497
 498         strcpy(obj->path, path);
 499         /* Using basename() GNU version which doesn't modify arg. */
 500         strncpy(obj->name, basename((void *)path), sizeof(obj->name) - 1);
 501         end = strchr(obj->name, '.');
 502         if (end)
 503                 *end = 0;
 504
 505         obj->efile.fd = -1;
 506         /*
 507          * Caller of this function should also call
 508          * bpf_object__elf_finish() after data collection to return
 509          * obj_buf to user. If not, we should duplicate the buffer to
 510          * avoid user freeing them before elf finish.
 511          */
 512         obj->efile.obj_buf = obj_buf;
 513         obj->efile.obj_buf_sz = obj_buf_sz;
 514         obj->efile.maps_shndx = -1;
 515         obj->efile.data_shndx = -1;
 516         obj->efile.rodata_shndx = -1;
 517         obj->efile.bss_shndx = -1;
 518
 519         obj->loaded = false;
 520
 521         INIT_LIST_HEAD(&obj->list);
 522         list_add(&obj->list, &bpf_objects_list);
 523         return obj;
 524 }
 525
 526 static void bpf_object__elf_finish(struct bpf_object *obj)
 527 {
 528         if (!obj_elf_valid(obj))
 529                 return;
 530
 531         if (obj->efile.elf) {
 532                 elf_end(obj->efile.elf);
 533                 obj->efile.elf = NULL;
 534         }
 535         obj->efile.symbols = NULL;
 536         obj->efile.data = NULL;
 537         obj->efile.rodata = NULL;
 538         obj->efile.bss = NULL;
 539
 540         zfree(&obj->efile.reloc);
 541         obj->efile.nr_reloc = 0;
 542         zclose(obj->efile.fd);
 543         obj->efile.obj_buf = NULL;
 544         obj->efile.obj_buf_sz = 0;
 545 }
 546
 547 static int bpf_object__elf_init(struct bpf_object *obj)
 548 {
 549         int err = 0;
 550         GElf_Ehdr *ep;
 551
 552         if (obj_elf_valid(obj)) {
 553                 pr_warning("elf init: internal error\n");
 554                 return -LIBBPF_ERRNO__LIBELF;
 555         }
 556
 557         if (obj->efile.obj_buf_sz > 0) {
 558                 /*
 559                  * obj_buf should have been validated by
 560                  * bpf_object__open_buffer().
 561                  */
 562                 obj->efile.elf = elf_memory(obj->efile.obj_buf,
 563                                             obj->efile.obj_buf_sz);
 564         } else {
 565                 obj->efile.fd = open(obj->path, O_RDONLY);
 566                 if (obj->efile.fd < 0) {
 567                         char errmsg[STRERR_BUFSIZE], *cp;
 568
 569                         err = -errno;
 570                         cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
 571                         pr_warning("failed to open %s: %s\n", obj->path, cp);
 572                         return err;
 573                 }
 574
 575                 obj->efile.elf = elf_begin(obj->efile.fd,
 576                                            LIBBPF_ELF_C_READ_MMAP, NULL);
 577         }
 578
 579         if (!obj->efile.elf) {
 580                 pr_warning("failed to open %s as ELF file\n", obj->path);
 581                 err = -LIBBPF_ERRNO__LIBELF;
 582                 goto errout;
 583         }
 584
 585         if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
 586                 pr_warning("failed to get EHDR from %s\n", obj->path);
 587                 err = -LIBBPF_ERRNO__FORMAT;
 588                 goto errout;
 589         }
 590         ep = &obj->efile.ehdr;
 591
 592         /* Old LLVM set e_machine to EM_NONE */
 593         if (ep->e_type != ET_REL ||
 594             (ep->e_machine && ep->e_machine != EM_BPF)) {
 595                 pr_warning("%s is not an eBPF object file\n", obj->path);
 596                 err = -LIBBPF_ERRNO__FORMAT;
 597                 goto errout;
 598         }
 599
 600         return 0;
 601 errout:
 602         bpf_object__elf_finish(obj);
 603         return err;
 604 }
 605
 606 static int bpf_object__check_endianness(struct bpf_object *obj)
 607 {
 608 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 609         if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2LSB)
 610                 return 0;
 611 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 612         if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2MSB)
 613                 return 0;
 614 #else
 615 # error "Unrecognized __BYTE_ORDER__"
 616 #endif
 617         pr_warning("endianness mismatch.\n");
 618         return -LIBBPF_ERRNO__ENDIAN;
 619 }
 620
 621 static int
 622 bpf_object__init_license(struct bpf_object *obj, void *data, size_t size)
 623 {
 624         memcpy(obj->license, data, min(size, sizeof(obj->license) - 1));
 625         pr_debug("license of %s is %s\n", obj->path, obj->license);
 626         return 0;
 627 }
 628
 629 static int
 630 bpf_object__init_kversion(struct bpf_object *obj, void *data, size_t size)
 631 {
 632         __u32 kver;
 633
 634         if (size != sizeof(kver)) {
 635                 pr_warning("invalid kver section in %s\n", obj->path);
 636                 return -LIBBPF_ERRNO__FORMAT;
 637         }
 638         memcpy(&kver, data, sizeof(kver));
 639         obj->kern_version = kver;
 640         pr_debug("kernel version of %s is %x\n", obj->path, obj->kern_version);
 641         return 0;
 642 }
 643
 644 static int compare_bpf_map(const void *_a, const void *_b)
 645 {
 646         const struct bpf_map *a = _a;
 647         const struct bpf_map *b = _b;
 648
 649         return a->offset - b->offset;
 650 }
 651
 652 static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
 653 {
 654         if (type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
 655             type == BPF_MAP_TYPE_HASH_OF_MAPS)
 656                 return true;
 657         return false;
 658 }
 659
 660 static int bpf_object_search_section_size(const struct bpf_object *obj,
 661                                           const char *name, size_t *d_size)
 662 {
 663         const GElf_Ehdr *ep = &obj->efile.ehdr;
 664         Elf *elf = obj->efile.elf;
 665         Elf_Scn *scn = NULL;
 666         int idx = 0;
 667
 668         while ((scn = elf_nextscn(elf, scn)) != NULL) {
 669                 const char *sec_name;
 670                 Elf_Data *data;
 671                 GElf_Shdr sh;
 672
 673                 idx++;
 674                 if (gelf_getshdr(scn, &sh) != &sh) {
 675                         pr_warning("failed to get section(%d) header from %s\n",
 676                                    idx, obj->path);
 677                         return -EIO;
 678                 }
 679
 680                 sec_name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
 681                 if (!sec_name) {
 682                         pr_warning("failed to get section(%d) name from %s\n",
 683                                    idx, obj->path);
 684                         return -EIO;
 685                 }
 686
 687                 if (strcmp(name, sec_name))
 688                         continue;
 689
 690                 data = elf_getdata(scn, 0);
 691                 if (!data) {
 692                         pr_warning("failed to get section(%d) data from %s(%s)\n",
 693                                    idx, name, obj->path);
 694                         return -EIO;
 695                 }
 696
 697                 *d_size = data->d_size;
 698                 return 0;
 699         }
 700
 701         return -ENOENT;
 702 }
 703
 704 int bpf_object__section_size(const struct bpf_object *obj, const char *name,
 705                              __u32 *size)
 706 {
 707         int ret = -ENOENT;
 708         size_t d_size;
 709
 710         *size = 0;
 711         if (!name) {
 712                 return -EINVAL;
 713         } else if (!strcmp(name, ".data")) {
 714                 if (obj->efile.data)
 715                         *size = obj->efile.data->d_size;
 716         } else if (!strcmp(name, ".bss")) {
 717                 if (obj->efile.bss)
 718                         *size = obj->efile.bss->d_size;
 719         } else if (!strcmp(name, ".rodata")) {
 720                 if (obj->efile.rodata)
 721                         *size = obj->efile.rodata->d_size;
 722         } else {
 723                 ret = bpf_object_search_section_size(obj, name, &d_size);
 724                 if (!ret)
 725                         *size = d_size;
 726         }
 727
 728         return *size ? 0 : ret;
 729 }
 730
 731 int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
 732                                 __u32 *off)
 733 {
 734         Elf_Data *symbols = obj->efile.symbols;
 735         const char *sname;
 736         size_t si;
 737
 738         if (!name || !off)
 739                 return -EINVAL;
 740
 741         for (si = 0; si < symbols->d_size / sizeof(GElf_Sym); si++) {
 742                 GElf_Sym sym;
 743
 744                 if (!gelf_getsym(symbols, si, &sym))
 745                         continue;
 746                 if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL ||
 747                     GELF_ST_TYPE(sym.st_info) != STT_OBJECT)
 748                         continue;
 749
 750                 sname = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
 751                                    sym.st_name);
 752                 if (!sname) {
 753                         pr_warning("failed to get sym name string for var %s\n",
 754                                    name);
 755                         return -EIO;
 756                 }
 757                 if (strcmp(name, sname) == 0) {
 758                         *off = sym.st_value;
 759                         return 0;
 760                 }
 761         }
 762
 763         return -ENOENT;
 764 }
 765
 766 static bool bpf_object__has_maps(const struct bpf_object *obj)
 767 {
 768         return obj->efile.maps_shndx >= 0 ||
 769                obj->efile.data_shndx >= 0 ||
 770                obj->efile.rodata_shndx >= 0 ||
 771                obj->efile.bss_shndx >= 0;
 772 }
 773
 774 static int
 775 bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map,
 776                               enum libbpf_map_type type, Elf_Data *data,
 777                               void **data_buff)
 778 {
 779         struct bpf_map_def *def = &map->def;
 780         char map_name[BPF_OBJ_NAME_LEN];
 781
 782         map->libbpf_type = type;
 783         map->offset = ~(typeof(map->offset))0;
 784         snprintf(map_name, sizeof(map_name), "%.8s%.7s", obj->name,
 785                  libbpf_type_to_btf_name[type]);
 786         map->name = strdup(map_name);
 787         if (!map->name) {
 788                 pr_warning("failed to alloc map name\n");
 789                 return -ENOMEM;
 790         }
 791
 792         def->type = BPF_MAP_TYPE_ARRAY;
 793         def->key_size = sizeof(int);
 794         def->value_size = data->d_size;
 795         def->max_entries = 1;
 796         def->map_flags = type == LIBBPF_MAP_RODATA ? BPF_F_RDONLY_PROG : 0;
 797         if (data_buff) {
 798                 *data_buff = malloc(data->d_size);
 799                 if (!*data_buff) {
 800                         zfree(&map->name);
 801                         pr_warning("failed to alloc map content buffer\n");
 802                         return -ENOMEM;
 803                 }
 804                 memcpy(*data_buff, data->d_buf, data->d_size);
 805         }
 806
 807         pr_debug("map %td is \"%s\"\n", map - obj->maps, map->name);
 808         return 0;
 809 }
 810
 811 static int bpf_object__init_maps(struct bpf_object *obj, int flags)
 812 {
 813         int i, map_idx, map_def_sz = 0, nr_syms, nr_maps = 0, nr_maps_glob = 0;
 814         bool strict = !(flags & MAPS_RELAX_COMPAT);
 815         Elf_Data *symbols = obj->efile.symbols;
 816         Elf_Data *data = NULL;
 817         int ret = 0;
 818
 819         if (!symbols)
 820                 return -EINVAL;
 821         nr_syms = symbols->d_size / sizeof(GElf_Sym);
 822
 823         if (obj->efile.maps_shndx >= 0) {
 824                 Elf_Scn *scn = elf_getscn(obj->efile.elf,
 825                                           obj->efile.maps_shndx);
 826
 827                 if (scn)
 828                         data = elf_getdata(scn, NULL);
 829                 if (!scn || !data) {
 830                         pr_warning("failed to get Elf_Data from map section %d\n",
 831                                    obj->efile.maps_shndx);
 832                         return -EINVAL;
 833                 }
 834         }
 835
 836         /*
 837          * Count number of maps. Each map has a name.
 838          * Array of maps is not supported: only the first element is
 839          * considered.
 840          *
 841          * TODO: Detect array of map and report error.
 842          */
 843         if (obj->caps.global_data) {
 844                 if (obj->efile.data_shndx >= 0)
 845                         nr_maps_glob++;
 846                 if (obj->efile.rodata_shndx >= 0)
 847                         nr_maps_glob++;
 848                 if (obj->efile.bss_shndx >= 0)
 849                         nr_maps_glob++;
 850         }
 851
 852         for (i = 0; data && i < nr_syms; i++) {
 853                 GElf_Sym sym;
 854
 855                 if (!gelf_getsym(symbols, i, &sym))
 856                         continue;
 857                 if (sym.st_shndx != obj->efile.maps_shndx)
 858                         continue;
 859                 nr_maps++;
 860         }
 861
 862         if (!nr_maps && !nr_maps_glob)
 863                 return 0;
 864
 865         /* Assume equally sized map definitions */
 866         if (data) {
 867                 pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path,
 868                          nr_maps, data->d_size);
 869
 870                 map_def_sz = data->d_size / nr_maps;
 871                 if (!data->d_size || (data->d_size % nr_maps) != 0) {
 872                         pr_warning("unable to determine map definition size "
 873                                    "section %s, %d maps in %zd bytes\n",
 874                                    obj->path, nr_maps, data->d_size);
 875                         return -EINVAL;
 876                 }
 877         }
 878
 879         nr_maps += nr_maps_glob;
 880         obj->maps = calloc(nr_maps, sizeof(obj->maps[0]));
 881         if (!obj->maps) {
 882                 pr_warning("alloc maps for object failed\n");
 883                 return -ENOMEM;
 884         }
 885         obj->nr_maps = nr_maps;
 886
 887         for (i = 0; i < nr_maps; i++) {
 888                 /*
 889                  * fill all fd with -1 so won't close incorrect
 890                  * fd (fd=0 is stdin) when failure (zclose won't close
 891                  * negative fd)).
 892                  */
 893                 obj->maps[i].fd = -1;
 894                 obj->maps[i].inner_map_fd = -1;
 895         }
 896
 897         /*
 898          * Fill obj->maps using data in "maps" section.
 899          */
 900         for (i = 0, map_idx = 0; data && i < nr_syms; i++) {
 901                 GElf_Sym sym;
 902                 const char *map_name;
 903                 struct bpf_map_def *def;
 904
 905                 if (!gelf_getsym(symbols, i, &sym))
 906                         continue;
 907                 if (sym.st_shndx != obj->efile.maps_shndx)
 908                         continue;
 909
 910                 map_name = elf_strptr(obj->efile.elf,
 911                                       obj->efile.strtabidx,
 912                                       sym.st_name);
 913                 if (!map_name) {
 914                         pr_warning("failed to get map #%d name sym string for obj %s\n",
 915                                    map_idx, obj->path);
 916                         return -LIBBPF_ERRNO__FORMAT;
 917                 }
 918
 919                 obj->maps[map_idx].libbpf_type = LIBBPF_MAP_UNSPEC;
 920                 obj->maps[map_idx].offset = sym.st_value;
 921                 if (sym.st_value + map_def_sz > data->d_size) {
 922                         pr_warning("corrupted maps section in %s: last map \"%s\" too small\n",
 923                                    obj->path, map_name);
 924                         return -EINVAL;
 925                 }
 926
 927                 obj->maps[map_idx].name = strdup(map_name);
 928                 if (!obj->maps[map_idx].name) {
 929                         pr_warning("failed to alloc map name\n");
 930                         return -ENOMEM;
 931                 }
 932                 pr_debug("map %d is \"%s\"\n", map_idx,
 933                          obj->maps[map_idx].name);
 934                 def = (struct bpf_map_def *)(data->d_buf + sym.st_value);
 935                 /*
 936                  * If the definition of the map in the object file fits in
 937                  * bpf_map_def, copy it.  Any extra fields in our version
 938                  * of bpf_map_def will default to zero as a result of the
 939                  * calloc above.
 940                  */
 941                 if (map_def_sz <= sizeof(struct bpf_map_def)) {
 942                         memcpy(&obj->maps[map_idx].def, def, map_def_sz);
 943                 } else {
 944                         /*
 945                          * Here the map structure being read is bigger than what
 946                          * we expect, truncate if the excess bits are all zero.
 947                          * If they are not zero, reject this map as
 948                          * incompatible.
 949                          */
 950                         char *b;
 951                         for (b = ((char *)def) + sizeof(struct bpf_map_def);
 952                              b < ((char *)def) + map_def_sz; b++) {
 953                                 if (*b != 0) {
 954                                         pr_warning("maps section in %s: \"%s\" "
 955                                                    "has unrecognized, non-zero "
 956                                                    "options\n",
 957                                                    obj->path, map_name);
 958                                         if (strict)
 959                                                 return -EINVAL;
 960                                 }
 961                         }
 962                         memcpy(&obj->maps[map_idx].def, def,
 963                                sizeof(struct bpf_map_def));
 964                 }
 965                 map_idx++;
 966         }
 967
 968         if (!obj->caps.global_data)
 969                 goto finalize;
 970
 971         /*
 972          * Populate rest of obj->maps with libbpf internal maps.
 973          */
 974         if (obj->efile.data_shndx >= 0)
 975                 ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
 976                                                     LIBBPF_MAP_DATA,
 977                                                     obj->efile.data,
 978                                                     &obj->sections.data);
 979         if (!ret && obj->efile.rodata_shndx >= 0)
 980                 ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
 981                                                     LIBBPF_MAP_RODATA,
 982                                                     obj->efile.rodata,
 983                                                     &obj->sections.rodata);
 984         if (!ret && obj->efile.bss_shndx >= 0)
 985                 ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
 986                                                     LIBBPF_MAP_BSS,
 987                                                     obj->efile.bss, NULL);
 988 finalize:
 989         if (!ret)
 990                 qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]),
 991                       compare_bpf_map);
 992         return ret;
 993 }
 994
 995 static bool section_have_execinstr(struct bpf_object *obj, int idx)
 996 {
 997         Elf_Scn *scn;
 998         GElf_Shdr sh;
 999
1000         scn = elf_getscn(obj->efile.elf, idx);
1001         if (!scn)
1002                 return false;
1003
1004         if (gelf_getshdr(scn, &sh) != &sh)
1005                 return false;
1006
1007         if (sh.sh_flags & SHF_EXECINSTR)
1008                 return true;
1009
1010         return false;
1011 }
1012
1013 static void bpf_object__sanitize_btf(struct bpf_object *obj)
1014 {
1015         bool has_datasec = obj->caps.btf_datasec;
1016         bool has_func = obj->caps.btf_func;
1017         struct btf *btf = obj->btf;
1018         struct btf_type *t;
1019         int i, j, vlen;
1020         __u16 kind;
1021
1022         if (!obj->btf || (has_func && has_datasec))
1023                 return;
1024
1025         for (i = 1; i <= btf__get_nr_types(btf); i++) {
1026                 t = (struct btf_type *)btf__type_by_id(btf, i);
1027                 kind = BTF_INFO_KIND(t->info);
1028
1029                 if (!has_datasec && kind == BTF_KIND_VAR) {
1030                         /* replace VAR with INT */
1031                         t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
1032                         t->size = sizeof(int);
1033                         *(int *)(t+1) = BTF_INT_ENC(0, 0, 32);
1034                 } else if (!has_datasec && kind == BTF_KIND_DATASEC) {
1035                         /* replace DATASEC with STRUCT */
1036                         struct btf_var_secinfo *v = (void *)(t + 1);
1037                         struct btf_member *m = (void *)(t + 1);
1038                         struct btf_type *vt;
1039                         char *name;
1040
1041                         name = (char *)btf__name_by_offset(btf, t->name_off);
1042                         while (*name) {
1043                                 if (*name == '.')
1044                                         *name = '_';
1045                                 name++;
1046                         }
1047
1048                         vlen = BTF_INFO_VLEN(t->info);
1049                         t->info = BTF_INFO_ENC(BTF_KIND_STRUCT, 0, vlen);
1050                         for (j = 0; j < vlen; j++, v++, m++) {
1051                                 /* order of field assignments is important */
1052                                 m->offset = v->offset * 8;
1053                                 m->type = v->type;
1054                                 /* preserve variable name as member name */
1055                                 vt = (void *)btf__type_by_id(btf, v->type);
1056                                 m->name_off = vt->name_off;
1057                         }
1058                 } else if (!has_func && kind == BTF_KIND_FUNC_PROTO) {
1059                         /* replace FUNC_PROTO with ENUM */
1060                         vlen = BTF_INFO_VLEN(t->info);
1061                         t->info = BTF_INFO_ENC(BTF_KIND_ENUM, 0, vlen);
1062                         t->size = sizeof(__u32); /* kernel enforced */
1063                 } else if (!has_func && kind == BTF_KIND_FUNC) {
1064                         /* replace FUNC with TYPEDEF */
1065                         t->info = BTF_INFO_ENC(BTF_KIND_TYPEDEF, 0, 0);
1066                 }
1067         }
1068 }
1069
1070 static void bpf_object__sanitize_btf_ext(struct bpf_object *obj)
1071 {
1072         if (!obj->btf_ext)
1073                 return;
1074
1075         if (!obj->caps.btf_func) {
1076                 btf_ext__free(obj->btf_ext);
1077                 obj->btf_ext = NULL;
1078         }
1079 }
1080
1081 static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
1082 {
1083         Elf *elf = obj->efile.elf;
1084         GElf_Ehdr *ep = &obj->efile.ehdr;
1085         Elf_Data *btf_ext_data = NULL;
1086         Elf_Data *btf_data = NULL;
1087         Elf_Scn *scn = NULL;
1088         int idx = 0, err = 0;
1089
1090         /* Elf is corrupted/truncated, avoid calling elf_strptr. */
1091         if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) {
1092                 pr_warning("failed to get e_shstrndx from %s\n", obj->path);
1093                 return -LIBBPF_ERRNO__FORMAT;
1094         }
1095
1096         while ((scn = elf_nextscn(elf, scn)) != NULL) {
1097                 char *name;
1098                 GElf_Shdr sh;
1099                 Elf_Data *data;
1100
1101                 idx++;
1102                 if (gelf_getshdr(scn, &sh) != &sh) {
1103                         pr_warning("failed to get section(%d) header from %s\n",
1104                                    idx, obj->path);
1105                         err = -LIBBPF_ERRNO__FORMAT;
1106                         goto out;
1107                 }
1108
1109                 name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
1110                 if (!name) {
1111                         pr_warning("failed to get section(%d) name from %s\n",
1112                                    idx, obj->path);
1113                         err = -LIBBPF_ERRNO__FORMAT;
1114                         goto out;
1115                 }
1116
1117                 data = elf_getdata(scn, 0);
1118                 if (!data) {
1119                         pr_warning("failed to get section(%d) data from %s(%s)\n",
1120                                    idx, name, obj->path);
1121                         err = -LIBBPF_ERRNO__FORMAT;
1122                         goto out;
1123                 }
1124                 pr_debug("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n",
1125                          idx, name, (unsigned long)data->d_size,
1126                          (int)sh.sh_link, (unsigned long)sh.sh_flags,
1127                          (int)sh.sh_type);
1128
1129                 if (strcmp(name, "license") == 0) {
1130                         err = bpf_object__init_license(obj,
1131                                                        data->d_buf,
1132                                                        data->d_size);
1133                 } else if (strcmp(name, "version") == 0) {
1134                         err = bpf_object__init_kversion(obj,
1135                                                         data->d_buf,
1136                                                         data->d_size);
1137                 } else if (strcmp(name, "maps") == 0) {
1138                         obj->efile.maps_shndx = idx;
1139                 } else if (strcmp(name, BTF_ELF_SEC) == 0) {
1140                         btf_data = data;
1141                 } else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
1142                         btf_ext_data = data;
1143                 } else if (sh.sh_type == SHT_SYMTAB) {
1144                         if (obj->efile.symbols) {
1145                                 pr_warning("bpf: multiple SYMTAB in %s\n",
1146                                            obj->path);
1147                                 err = -LIBBPF_ERRNO__FORMAT;
1148                         } else {
1149                                 obj->efile.symbols = data;
1150                                 obj->efile.strtabidx = sh.sh_link;
1151                         }
1152                 } else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) {
1153                         if (sh.sh_flags & SHF_EXECINSTR) {
1154                                 if (strcmp(name, ".text") == 0)
1155                                         obj->efile.text_shndx = idx;
1156                                 err = bpf_object__add_program(obj, data->d_buf,
1157                                                               data->d_size, name, idx);
1158                                 if (err) {
1159                                         char errmsg[STRERR_BUFSIZE];
1160                                         char *cp = libbpf_strerror_r(-err, errmsg,
1161                                                                      sizeof(errmsg));
1162
1163                                         pr_warning("failed to alloc program %s (%s): %s",
1164                                                    name, obj->path, cp);
1165                                 }
1166                         } else if (strcmp(name, ".data") == 0) {
1167                                 obj->efile.data = data;
1168                                 obj->efile.data_shndx = idx;
1169                         } else if (strcmp(name, ".rodata") == 0) {
1170                                 obj->efile.rodata = data;
1171                                 obj->efile.rodata_shndx = idx;
1172                         } else {
1173                                 pr_debug("skip section(%d) %s\n", idx, name);
1174                         }
1175                 } else if (sh.sh_type == SHT_REL) {
1176                         void *reloc = obj->efile.reloc;
1177                         int nr_reloc = obj->efile.nr_reloc + 1;
1178                         int sec = sh.sh_info; /* points to other section */
1179
1180                         /* Only do relo for section with exec instructions */
1181                         if (!section_have_execinstr(obj, sec)) {
1182                                 pr_debug("skip relo %s(%d) for section(%d)\n",
1183                                          name, idx, sec);
1184                                 continue;
1185                         }
1186
1187                         reloc = reallocarray(reloc, nr_reloc,
1188                                              sizeof(*obj->efile.reloc));
1189                         if (!reloc) {
1190                                 pr_warning("realloc failed\n");
1191                                 err = -ENOMEM;
1192                         } else {
1193                                 int n = nr_reloc - 1;
1194
1195                                 obj->efile.reloc = reloc;
1196                                 obj->efile.nr_reloc = nr_reloc;
1197
1198                                 obj->efile.reloc[n].shdr = sh;
1199                                 obj->efile.reloc[n].data = data;
1200                         }
1201                 } else if (sh.sh_type == SHT_NOBITS && strcmp(name, ".bss") == 0) {
1202                         obj->efile.bss = data;
1203                         obj->efile.bss_shndx = idx;
1204                 } else {
1205                         pr_debug("skip section(%d) %s\n", idx, name);
1206                 }
1207                 if (err)
1208                         goto out;
1209         }
1210
1211         if (!obj->efile.strtabidx || obj->efile.strtabidx >= idx) {
1212                 pr_warning("Corrupted ELF file: index of strtab invalid\n");
1213                 return -LIBBPF_ERRNO__FORMAT;
1214         }
1215         if (btf_data) {
1216                 obj->btf = btf__new(btf_data->d_buf, btf_data->d_size);
1217                 if (IS_ERR(obj->btf)) {
1218                         pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
1219                                    BTF_ELF_SEC, PTR_ERR(obj->btf));
1220                         obj->btf = NULL;
1221                 } else {
1222                         err = btf__finalize_data(obj, obj->btf);
1223                         if (!err) {
1224                                 bpf_object__sanitize_btf(obj);
1225                                 err = btf__load(obj->btf);
1226                         }
1227                         if (err) {
1228                                 pr_warning("Error finalizing and loading %s into kernel: %d. Ignored and continue.\n",
1229                                            BTF_ELF_SEC, err);
1230                                 btf__free(obj->btf);
1231                                 obj->btf = NULL;
1232                                 err = 0;
1233                         }
1234                 }
1235         }
1236         if (btf_ext_data) {
1237                 if (!obj->btf) {
1238                         pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
1239                                  BTF_EXT_ELF_SEC, BTF_ELF_SEC);
1240                 } else {
1241                         obj->btf_ext = btf_ext__new(btf_ext_data->d_buf,
1242                                                     btf_ext_data->d_size);
1243                         if (IS_ERR(obj->btf_ext)) {
1244                                 pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
1245                                            BTF_EXT_ELF_SEC,
1246                                            PTR_ERR(obj->btf_ext));
1247                                 obj->btf_ext = NULL;
1248                         } else {
1249                                 bpf_object__sanitize_btf_ext(obj);
1250                         }
1251                 }
1252         }
1253         if (bpf_object__has_maps(obj)) {
1254                 err = bpf_object__init_maps(obj, flags);
1255                 if (err)
1256                         goto out;
1257         }
1258         err = bpf_object__init_prog_names(obj);
1259 out:
1260         return err;
1261 }
1262
1263 static struct bpf_program *
1264 bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx)
1265 {
1266         struct bpf_program *prog;
1267         size_t i;
1268
1269         for (i = 0; i < obj->nr_programs; i++) {
1270                 prog = &obj->programs[i];
1271                 if (prog->idx == idx)
1272                         return prog;
1273         }
1274         return NULL;
1275 }
1276
1277 struct bpf_program *
1278 bpf_object__find_program_by_title(struct bpf_object *obj, const char *title)
1279 {
1280         struct bpf_program *pos;
1281
1282         bpf_object__for_each_program(pos, obj) {
1283                 if (pos->section_name && !strcmp(pos->section_name, title))
1284                         return pos;
1285         }
1286         return NULL;
1287 }
1288
1289 static bool bpf_object__shndx_is_data(const struct bpf_object *obj,
1290                                       int shndx)
1291 {
1292         return shndx == obj->efile.data_shndx ||
1293                shndx == obj->efile.bss_shndx ||
1294                shndx == obj->efile.rodata_shndx;
1295 }
1296
1297 static bool bpf_object__shndx_is_maps(const struct bpf_object *obj,
1298                                       int shndx)
1299 {
1300         return shndx == obj->efile.maps_shndx;
1301 }
1302
1303 static bool bpf_object__relo_in_known_section(const struct bpf_object *obj,
1304                                               int shndx)
1305 {
1306         return shndx == obj->efile.text_shndx ||
1307                bpf_object__shndx_is_maps(obj, shndx) ||
1308                bpf_object__shndx_is_data(obj, shndx);
1309 }
1310
1311 static enum libbpf_map_type
1312 bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx)
1313 {
1314         if (shndx == obj->efile.data_shndx)
1315                 return LIBBPF_MAP_DATA;
1316         else if (shndx == obj->efile.bss_shndx)
1317                 return LIBBPF_MAP_BSS;
1318         else if (shndx == obj->efile.rodata_shndx)
1319                 return LIBBPF_MAP_RODATA;
1320         else
1321                 return LIBBPF_MAP_UNSPEC;
1322 }
1323
1324 static int
1325 bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
1326                            Elf_Data *data, struct bpf_object *obj)
1327 {
1328         Elf_Data *symbols = obj->efile.symbols;
1329         struct bpf_map *maps = obj->maps;
1330         size_t nr_maps = obj->nr_maps;
1331         int i, nrels;
1332
1333         pr_debug("collecting relocating info for: '%s'\n", prog->section_name);
1334         nrels = shdr->sh_size / shdr->sh_entsize;
1335
1336         prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels);
1337         if (!prog->reloc_desc) {
1338                 pr_warning("failed to alloc memory in relocation\n");
1339                 return -ENOMEM;
1340         }
1341         prog->nr_reloc = nrels;
1342
1343         for (i = 0; i < nrels; i++) {
1344                 GElf_Sym sym;
1345                 GElf_Rel rel;
1346                 unsigned int insn_idx;
1347                 unsigned int shdr_idx;
1348                 struct bpf_insn *insns = prog->insns;
1349                 enum libbpf_map_type type;
1350                 const char *name;
1351                 size_t map_idx;
1352
1353                 if (!gelf_getrel(data, i, &rel)) {
1354                         pr_warning("relocation: failed to get %d reloc\n", i);
1355                         return -LIBBPF_ERRNO__FORMAT;
1356                 }
1357
1358                 if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
1359                         pr_warning("relocation: symbol %"PRIx64" not found\n",
1360                                    GELF_R_SYM(rel.r_info));
1361                         return -LIBBPF_ERRNO__FORMAT;
1362                 }
1363
1364                 name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
1365                                   sym.st_name) ? : "<?>";
1366
1367                 pr_debug("relo for %lld value %lld name %d (\'%s\')\n",
1368                          (long long) (rel.r_info >> 32),
1369                          (long long) sym.st_value, sym.st_name, name);
1370
1371                 shdr_idx = sym.st_shndx;
1372                 if (!bpf_object__relo_in_known_section(obj, shdr_idx)) {
1373                         pr_warning("Program '%s' contains unrecognized relo data pointing to section %u\n",
1374                                    prog->section_name, shdr_idx);
1375                         return -LIBBPF_ERRNO__RELOC;
1376                 }
1377
1378                 insn_idx = rel.r_offset / sizeof(struct bpf_insn);
1379                 pr_debug("relocation: insn_idx=%u\n", insn_idx);
1380
1381                 if (insns[insn_idx].code == (BPF_JMP | BPF_CALL)) {
1382                         if (insns[insn_idx].src_reg != BPF_PSEUDO_CALL) {
1383                                 pr_warning("incorrect bpf_call opcode\n");
1384                                 return -LIBBPF_ERRNO__RELOC;
1385                         }
1386                         prog->reloc_desc[i].type = RELO_CALL;
1387                         prog->reloc_desc[i].insn_idx = insn_idx;
1388                         prog->reloc_desc[i].text_off = sym.st_value;
1389                         obj->has_pseudo_calls = true;
1390                         continue;
1391                 }
1392
1393                 if (insns[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
1394                         pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n",
1395                                    insn_idx, insns[insn_idx].code);
1396                         return -LIBBPF_ERRNO__RELOC;
1397                 }
1398
1399                 if (bpf_object__shndx_is_maps(obj, shdr_idx) ||
1400                     bpf_object__shndx_is_data(obj, shdr_idx)) {
1401                         type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx);
1402                         if (type != LIBBPF_MAP_UNSPEC) {
1403                                 if (GELF_ST_BIND(sym.st_info) == STB_GLOBAL) {
1404                                         pr_warning("bpf: relocation: not yet supported relo for non-static global \'%s\' variable found in insns[%d].code 0x%x\n",
1405                                                    name, insn_idx, insns[insn_idx].code);
1406                                         return -LIBBPF_ERRNO__RELOC;
1407                                 }
1408                                 if (!obj->caps.global_data) {
1409                                         pr_warning("bpf: relocation: kernel does not support global \'%s\' variable access in insns[%d]\n",
1410                                                    name, insn_idx);
1411                                         return -LIBBPF_ERRNO__RELOC;
1412                                 }
1413                         }
1414
1415                         for (map_idx = 0; map_idx < nr_maps; map_idx++) {
1416                                 if (maps[map_idx].libbpf_type != type)
1417                                         continue;
1418                                 if (type != LIBBPF_MAP_UNSPEC ||
1419                                     maps[map_idx].offset == sym.st_value) {
1420                                         pr_debug("relocation: find map %zd (%s) for insn %u\n",
1421                                                  map_idx, maps[map_idx].name, insn_idx);
1422                                         break;
1423                                 }
1424                         }
1425
1426                         if (map_idx >= nr_maps) {
1427                                 pr_warning("bpf relocation: map_idx %d larger than %d\n",
1428                                            (int)map_idx, (int)nr_maps - 1);
1429                                 return -LIBBPF_ERRNO__RELOC;
1430                         }
1431
1432                         prog->reloc_desc[i].type = type != LIBBPF_MAP_UNSPEC ?
1433                                                    RELO_DATA : RELO_LD64;
1434                         prog->reloc_desc[i].insn_idx = insn_idx;
1435                         prog->reloc_desc[i].map_idx = map_idx;
1436                 }
1437         }
1438         return 0;
1439 }
1440
1441 static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf)
1442 {
1443         struct bpf_map_def *def = &map->def;
1444         __u32 key_type_id = 0, value_type_id = 0;
1445         int ret;
1446
1447         if (!bpf_map__is_internal(map)) {
1448                 ret = btf__get_map_kv_tids(btf, map->name, def->key_size,
1449                                            def->value_size, &key_type_id,
1450                                            &value_type_id);
1451         } else {
1452                 /*
1453                  * LLVM annotates global data differently in BTF, that is,
1454                  * only as '.data', '.bss' or '.rodata'.
1455                  */
1456                 ret = btf__find_by_name(btf,
1457                                 libbpf_type_to_btf_name[map->libbpf_type]);
1458         }
1459         if (ret < 0)
1460                 return ret;
1461
1462         map->btf_key_type_id = key_type_id;
1463         map->btf_value_type_id = bpf_map__is_internal(map) ?
1464                                  ret : value_type_id;
1465         return 0;
1466 }
1467
1468 int bpf_map__reuse_fd(struct bpf_map *map, int fd)
1469 {
1470         struct bpf_map_info info = {};
1471         __u32 len = sizeof(info);
1472         int new_fd, err;
1473         char *new_name;
1474
1475         err = bpf_obj_get_info_by_fd(fd, &info, &len);
1476         if (err)
1477                 return err;
1478
1479         new_name = strdup(info.name);
1480         if (!new_name)
1481                 return -errno;
1482
1483         new_fd = open("/", O_RDONLY | O_CLOEXEC);
1484         if (new_fd < 0)
1485                 goto err_free_new_name;
1486
1487         new_fd = dup3(fd, new_fd, O_CLOEXEC);
1488         if (new_fd < 0)
1489                 goto err_close_new_fd;
1490
1491         err = zclose(map->fd);
1492         if (err)
1493                 goto err_close_new_fd;
1494         free(map->name);
1495
1496         map->fd = new_fd;
1497         map->name = new_name;
1498         map->def.type = info.type;
1499         map->def.key_size = info.key_size;
1500         map->def.value_size = info.value_size;
1501         map->def.max_entries = info.max_entries;
1502         map->def.map_flags = info.map_flags;
1503         map->btf_key_type_id = info.btf_key_type_id;
1504         map->btf_value_type_id = info.btf_value_type_id;
1505
1506         return 0;
1507
1508 err_close_new_fd:
1509         close(new_fd);
1510 err_free_new_name:
1511         free(new_name);
1512         return -errno;
1513 }
1514
1515 int bpf_map__resize(struct bpf_map *map, __u32 max_entries)
1516 {
1517         if (!map || !max_entries)
1518                 return -EINVAL;
1519
1520         /* If map already created, its attributes can't be changed. */
1521         if (map->fd >= 0)
1522                 return -EBUSY;
1523
1524         map->def.max_entries = max_entries;
1525
1526         return 0;
1527 }
1528
1529 static int
1530 bpf_object__probe_name(struct bpf_object *obj)
1531 {
1532         struct bpf_load_program_attr attr;
1533         char *cp, errmsg[STRERR_BUFSIZE];
1534         struct bpf_insn insns[] = {
1535                 BPF_MOV64_IMM(BPF_REG_0, 0),
1536                 BPF_EXIT_INSN(),
1537         };
1538         int ret;
1539
1540         /* make sure basic loading works */
1541
1542         memset(&attr, 0, sizeof(attr));
1543         attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
1544         attr.insns = insns;
1545         attr.insns_cnt = ARRAY_SIZE(insns);
1546         attr.license = "GPL";
1547
1548         ret = bpf_load_program_xattr(&attr, NULL, 0);
1549         if (ret < 0) {
1550                 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
1551                 pr_warning("Error in %s():%s(%d). Couldn't load basic 'r0 = 0' BPF program.\n",
1552                            __func__, cp, errno);
1553                 return -errno;
1554         }
1555         close(ret);
1556
1557         /* now try the same program, but with the name */
1558
1559         attr.name = "test";
1560         ret = bpf_load_program_xattr(&attr, NULL, 0);
1561         if (ret >= 0) {
1562                 obj->caps.name = 1;
1563                 close(ret);
1564         }
1565
1566         return 0;
1567 }
1568
1569 static int
1570 bpf_object__probe_global_data(struct bpf_object *obj)
1571 {
1572         struct bpf_load_program_attr prg_attr;
1573         struct bpf_create_map_attr map_attr;
1574         char *cp, errmsg[STRERR_BUFSIZE];
1575         struct bpf_insn insns[] = {
1576                 BPF_LD_MAP_VALUE(BPF_REG_1, 0, 16),
1577                 BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 42),
1578                 BPF_MOV64_IMM(BPF_REG_0, 0),
1579                 BPF_EXIT_INSN(),
1580         };
1581         int ret, map;
1582
1583         memset(&map_attr, 0, sizeof(map_attr));
1584         map_attr.map_type = BPF_MAP_TYPE_ARRAY;
1585         map_attr.key_size = sizeof(int);
1586         map_attr.value_size = 32;
1587         map_attr.max_entries = 1;
1588
1589         map = bpf_create_map_xattr(&map_attr);
1590         if (map < 0) {
1591                 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
1592                 pr_warning("Error in %s():%s(%d). Couldn't create simple array map.\n",
1593                            __func__, cp, errno);
1594                 return -errno;
1595         }
1596
1597         insns[0].imm = map;
1598
1599         memset(&prg_attr, 0, sizeof(prg_attr));
1600         prg_attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
1601         prg_attr.insns = insns;
1602         prg_attr.insns_cnt = ARRAY_SIZE(insns);
1603         prg_attr.license = "GPL";
1604
1605         ret = bpf_load_program_xattr(&prg_attr, NULL, 0);
1606         if (ret >= 0) {
1607                 obj->caps.global_data = 1;
1608                 close(ret);
1609         }
1610
1611         close(map);
1612         return 0;
1613 }
1614
1615 static int bpf_object__probe_btf_func(struct bpf_object *obj)
1616 {
1617         const char strs[] = "\0int\0x\0a";
1618         /* void x(int a) {} */
1619         __u32 types[] = {
1620                 /* int */
1621                 BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4),  /* [1] */
1622                 /* FUNC_PROTO */                                /* [2] */
1623                 BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_FUNC_PROTO, 0, 1), 0),
1624                 BTF_PARAM_ENC(7, 1),
1625                 /* FUNC x */                                    /* [3] */
1626                 BTF_TYPE_ENC(5, BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0), 2),
1627         };
1628         int res;
1629
1630         res = libbpf__probe_raw_btf((char *)types, sizeof(types),
1631                                     strs, sizeof(strs));
1632         if (res < 0)
1633                 return res;
1634         if (res > 0)
1635                 obj->caps.btf_func = 1;
1636         return 0;
1637 }
1638
1639 static int bpf_object__probe_btf_datasec(struct bpf_object *obj)
1640 {
1641         const char strs[] = "\0x\0.data";
1642         /* static int a; */
1643         __u32 types[] = {
1644                 /* int */
1645                 BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),  /* [1] */
1646                 /* VAR x */                                     /* [2] */
1647                 BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
1648                 BTF_VAR_STATIC,
1649                 /* DATASEC val */                               /* [3] */
1650                 BTF_TYPE_ENC(3, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
1651                 BTF_VAR_SECINFO_ENC(2, 0, 4),
1652         };
1653         int res;
1654
1655         res = libbpf__probe_raw_btf((char *)types, sizeof(types),
1656                                     strs, sizeof(strs));
1657         if (res < 0)
1658                 return res;
1659         if (res > 0)
1660                 obj->caps.btf_datasec = 1;
1661         return 0;
1662 }
1663
1664 static int
1665 bpf_object__probe_caps(struct bpf_object *obj)
1666 {
1667         int (*probe_fn[])(struct bpf_object *obj) = {
1668                 bpf_object__probe_name,
1669                 bpf_object__probe_global_data,
1670                 bpf_object__probe_btf_func,
1671                 bpf_object__probe_btf_datasec,
1672         };
1673         int i, ret;
1674
1675         for (i = 0; i < ARRAY_SIZE(probe_fn); i++) {
1676                 ret = probe_fn[i](obj);
1677                 if (ret < 0)
1678                         pr_debug("Probe #%d failed with %d.\n", i, ret);
1679         }
1680
1681         return 0;
1682 }
1683
1684 static int
1685 bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
1686 {
1687         char *cp, errmsg[STRERR_BUFSIZE];
1688         int err, zero = 0;
1689         __u8 *data;
1690
1691         /* Nothing to do here since kernel already zero-initializes .bss map. */
1692         if (map->libbpf_type == LIBBPF_MAP_BSS)
1693                 return 0;
1694
1695         data = map->libbpf_type == LIBBPF_MAP_DATA ?
1696                obj->sections.data : obj->sections.rodata;
1697
1698         err = bpf_map_update_elem(map->fd, &zero, data, 0);
1699         /* Freeze .rodata map as read-only from syscall side. */
1700         if (!err && map->libbpf_type == LIBBPF_MAP_RODATA) {
1701                 err = bpf_map_freeze(map->fd);
1702                 if (err) {
1703                         cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
1704                         pr_warning("Error freezing map(%s) as read-only: %s\n",
1705                                    map->name, cp);
1706                         err = 0;
1707                 }
1708         }
1709         return err;
1710 }
1711
1712 static int
1713 bpf_object__create_maps(struct bpf_object *obj)
1714 {
1715         struct bpf_create_map_attr create_attr = {};
1716         unsigned int i;
1717         int err;
1718
1719         for (i = 0; i < obj->nr_maps; i++) {
1720                 struct bpf_map *map = &obj->maps[i];
1721                 struct bpf_map_def *def = &map->def;
1722                 char *cp, errmsg[STRERR_BUFSIZE];
1723                 int *pfd = &map->fd;
1724
1725                 if (map->fd >= 0) {
1726                         pr_debug("skip map create (preset) %s: fd=%d\n",
1727                                  map->name, map->fd);
1728                         continue;
1729                 }
1730
1731                 if (obj->caps.name)
1732                         create_attr.name = map->name;
1733                 create_attr.map_ifindex = map->map_ifindex;
1734                 create_attr.map_type = def->type;
1735                 create_attr.map_flags = def->map_flags;
1736                 create_attr.key_size = def->key_size;
1737                 create_attr.value_size = def->value_size;
1738                 create_attr.max_entries = def->max_entries;
1739                 create_attr.btf_fd = -1;
1740                 create_attr.btf_key_type_id = 0;
1741                 create_attr.btf_value_type_id = 0;
1742                 if (bpf_map_type__is_map_in_map(def->type) &&
1743                     map->inner_map_fd >= 0)
1744                         create_attr.inner_map_fd = map->inner_map_fd;
1745
1746                 if (obj->btf && !bpf_map_find_btf_info(map, obj->btf)) {
1747                         create_attr.btf_fd = btf__fd(obj->btf);
1748                         create_attr.btf_key_type_id = map->btf_key_type_id;
1749                         create_attr.btf_value_type_id = map->btf_value_type_id;
1750                 }
1751
1752                 *pfd = bpf_create_map_xattr(&create_attr);
1753                 if (*pfd < 0 && create_attr.btf_fd >= 0) {
1754                         cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
1755                         pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n",
1756                                    map->name, cp, errno);
1757                         create_attr.btf_fd = -1;
1758                         create_attr.btf_key_type_id = 0;
1759                         create_attr.btf_value_type_id = 0;
1760                         map->btf_key_type_id = 0;
1761                         map->btf_value_type_id = 0;
1762                         *pfd = bpf_create_map_xattr(&create_attr);
1763                 }
1764
1765                 if (*pfd < 0) {
1766                         size_t j;
1767
1768                         err = *pfd;
1769 err_out:
1770                         cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
1771                         pr_warning("failed to create map (name: '%s'): %s\n",
1772                                    map->name, cp);
1773                         for (j = 0; j < i; j++)
1774                                 zclose(obj->maps[j].fd);
1775                         return err;
1776                 }
1777
1778                 if (bpf_map__is_internal(map)) {
1779                         err = bpf_object__populate_internal_map(obj, map);
1780                         if (err < 0) {
1781                                 zclose(*pfd);
1782                                 goto err_out;
1783                         }
1784                 }
1785
1786                 pr_debug("created map %s: fd=%d\n", map->name, *pfd);
1787         }
1788
1789         return 0;
1790 }
1791
1792 static int
1793 check_btf_ext_reloc_err(struct bpf_program *prog, int err,
1794                         void *btf_prog_info, const char *info_name)
1795 {
1796         if (err != -ENOENT) {
1797                 pr_warning("Error in loading %s for sec %s.\n",
1798                            info_name, prog->section_name);
1799                 return err;
1800         }
1801
1802         /* err == -ENOENT (i.e. prog->section_name not found in btf_ext) */
1803
1804         if (btf_prog_info) {
1805                 /*
1806                  * Some info has already been found but has problem
1807                  * in the last btf_ext reloc. Must have to error out.
1808                  */
1809                 pr_warning("Error in relocating %s for sec %s.\n",
1810                            info_name, prog->section_name);
1811                 return err;
1812         }
1813
1814         /* Have problem loading the very first info. Ignore the rest. */
1815         pr_warning("Cannot find %s for main program sec %s. Ignore all %s.\n",
1816                    info_name, prog->section_name, info_name);
1817         return 0;
1818 }
1819
1820 static int
1821 bpf_program_reloc_btf_ext(struct bpf_program *prog, struct bpf_object *obj,
1822                           const char *section_name,  __u32 insn_offset)
1823 {
1824         int err;
1825
1826         if (!insn_offset || prog->func_info) {
1827                 /*
1828                  * !insn_offset => main program
1829                  *
1830                  * For sub prog, the main program's func_info has to
1831                  * be loaded first (i.e. prog->func_info != NULL)
1832                  */
1833                 err = btf_ext__reloc_func_info(obj->btf, obj->btf_ext,
1834                                                section_name, insn_offset,
1835                                                &prog->func_info,
1836                                                &prog->func_info_cnt);
1837                 if (err)
1838                         return check_btf_ext_reloc_err(prog, err,
1839                                                        prog->func_info,
1840                                                        "bpf_func_info");
1841
1842                 prog->func_info_rec_size = btf_ext__func_info_rec_size(obj->btf_ext);
1843         }
1844
1845         if (!insn_offset || prog->line_info) {
1846                 err = btf_ext__reloc_line_info(obj->btf, obj->btf_ext,
1847                                                section_name, insn_offset,
1848                                                &prog->line_info,
1849                                                &prog->line_info_cnt);
1850                 if (err)
1851                         return check_btf_ext_reloc_err(prog, err,
1852                                                        prog->line_info,
1853                                                        "bpf_line_info");
1854
1855                 prog->line_info_rec_size = btf_ext__line_info_rec_size(obj->btf_ext);
1856         }
1857
1858         if (!insn_offset)
1859                 prog->btf_fd = btf__fd(obj->btf);
1860
1861         return 0;
1862 }
1863
1864 static int
1865 bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
1866                         struct reloc_desc *relo)
1867 {
1868         struct bpf_insn *insn, *new_insn;
1869         struct bpf_program *text;
1870         size_t new_cnt;
1871         int err;
1872
1873         if (relo->type != RELO_CALL)
1874                 return -LIBBPF_ERRNO__RELOC;
1875
1876         if (prog->idx == obj->efile.text_shndx) {
1877                 pr_warning("relo in .text insn %d into off %d\n",
1878                            relo->insn_idx, relo->text_off);
1879                 return -LIBBPF_ERRNO__RELOC;
1880         }
1881
1882         if (prog->main_prog_cnt == 0) {
1883                 text = bpf_object__find_prog_by_idx(obj, obj->efile.text_shndx);
1884                 if (!text) {
1885                         pr_warning("no .text section found yet relo into text exist\n");
1886                         return -LIBBPF_ERRNO__RELOC;
1887                 }
1888                 new_cnt = prog->insns_cnt + text->insns_cnt;
1889                 new_insn = reallocarray(prog->insns, new_cnt, sizeof(*insn));
1890                 if (!new_insn) {
1891                         pr_warning("oom in prog realloc\n");
1892                         return -ENOMEM;
1893                 }
1894
1895                 if (obj->btf_ext) {
1896                         err = bpf_program_reloc_btf_ext(prog, obj,
1897                                                         text->section_name,
1898                                                         prog->insns_cnt);
1899                         if (err)
1900                                 return err;
1901                 }
1902
1903                 memcpy(new_insn + prog->insns_cnt, text->insns,
1904                        text->insns_cnt * sizeof(*insn));
1905                 prog->insns = new_insn;
1906                 prog->main_prog_cnt = prog->insns_cnt;
1907                 prog->insns_cnt = new_cnt;
1908                 pr_debug("added %zd insn from %s to prog %s\n",
1909                          text->insns_cnt, text->section_name,
1910                          prog->section_name);
1911         }
1912         insn = &prog->insns[relo->insn_idx];
1913         insn->imm += prog->main_prog_cnt - relo->insn_idx;
1914         return 0;
1915 }
1916
1917 static int
1918 bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
1919 {
1920         int i, err;
1921
1922         if (!prog)
1923                 return 0;
1924
1925         if (obj->btf_ext) {
1926                 err = bpf_program_reloc_btf_ext(prog, obj,
1927                                                 prog->section_name, 0);
1928                 if (err)
1929                         return err;
1930         }
1931
1932         if (!prog->reloc_desc)
1933                 return 0;
1934
1935         for (i = 0; i < prog->nr_reloc; i++) {
1936                 if (prog->reloc_desc[i].type == RELO_LD64 ||
1937                     prog->reloc_desc[i].type == RELO_DATA) {
1938                         bool relo_data = prog->reloc_desc[i].type == RELO_DATA;
1939                         struct bpf_insn *insns = prog->insns;
1940                         int insn_idx, map_idx;
1941
1942                         insn_idx = prog->reloc_desc[i].insn_idx;
1943                         map_idx = prog->reloc_desc[i].map_idx;
1944
1945                         if (insn_idx + 1 >= (int)prog->insns_cnt) {
1946                                 pr_warning("relocation out of range: '%s'\n",
1947                                            prog->section_name);
1948                                 return -LIBBPF_ERRNO__RELOC;
1949                         }
1950
1951                         if (!relo_data) {
1952                                 insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
1953                         } else {
1954                                 insns[insn_idx].src_reg = BPF_PSEUDO_MAP_VALUE;
1955                                 insns[insn_idx + 1].imm = insns[insn_idx].imm;
1956                         }
1957                         insns[insn_idx].imm = obj->maps[map_idx].fd;
1958                 } else if (prog->reloc_desc[i].type == RELO_CALL) {
1959                         err = bpf_program__reloc_text(prog, obj,
1960                                                       &prog->reloc_desc[i]);
1961                         if (err)
1962                                 return err;
1963                 }
1964         }
1965
1966         zfree(&prog->reloc_desc);
1967         prog->nr_reloc = 0;
1968         return 0;
1969 }
1970
1971
1972 static int
1973 bpf_object__relocate(struct bpf_object *obj)
1974 {
1975         struct bpf_program *prog;
1976         size_t i;
1977         int err;
1978
1979         for (i = 0; i < obj->nr_programs; i++) {
1980                 prog = &obj->programs[i];
1981
1982                 err = bpf_program__relocate(prog, obj);
1983                 if (err) {
1984                         pr_warning("failed to relocate '%s'\n",
1985                                    prog->section_name);
1986                         return err;
1987                 }
1988         }
1989         return 0;
1990 }
1991
1992 static int bpf_object__collect_reloc(struct bpf_object *obj)
1993 {
1994         int i, err;
1995
1996         if (!obj_elf_valid(obj)) {
1997                 pr_warning("Internal error: elf object is closed\n");
1998                 return -LIBBPF_ERRNO__INTERNAL;
1999         }
2000
2001         for (i = 0; i < obj->efile.nr_reloc; i++) {
2002                 GElf_Shdr *shdr = &obj->efile.reloc[i].shdr;
2003                 Elf_Data *data = obj->efile.reloc[i].data;
2004                 int idx = shdr->sh_info;
2005                 struct bpf_program *prog;
2006
2007                 if (shdr->sh_type != SHT_REL) {
2008                         pr_warning("internal error at %d\n", __LINE__);
2009                         return -LIBBPF_ERRNO__INTERNAL;
2010                 }
2011
2012                 prog = bpf_object__find_prog_by_idx(obj, idx);
2013                 if (!prog) {
2014                         pr_warning("relocation failed: no section(%d)\n", idx);
2015                         return -LIBBPF_ERRNO__RELOC;
2016                 }
2017
2018                 err = bpf_program__collect_reloc(prog, shdr, data, obj);
2019                 if (err)
2020                         return err;
2021         }
2022         return 0;
2023 }
2024
2025 static int
2026 load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
2027              char *license, __u32 kern_version, int *pfd)
2028 {
2029         struct bpf_load_program_attr load_attr;
2030         char *cp, errmsg[STRERR_BUFSIZE];
2031         int log_buf_size = BPF_LOG_BUF_SIZE;
2032         char *log_buf;
2033         int ret;
2034
2035         if (!insns || !insns_cnt)
2036                 return -EINVAL;
2037
2038         memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
2039         load_attr.prog_type = prog->type;
2040         load_attr.expected_attach_type = prog->expected_attach_type;
2041         if (prog->caps->name)
2042                 load_attr.name = prog->name;
2043         load_attr.insns = insns;
2044         load_attr.insns_cnt = insns_cnt;
2045         load_attr.license = license;
2046         load_attr.kern_version = kern_version;
2047         load_attr.prog_ifindex = prog->prog_ifindex;
2048         load_attr.prog_btf_fd = prog->btf_fd;
2049         load_attr.func_info = prog->func_info;
2050         load_attr.func_info_rec_size = prog->func_info_rec_size;
2051         load_attr.func_info_cnt = prog->func_info_cnt;
2052         load_attr.line_info = prog->line_info;
2053         load_attr.line_info_rec_size = prog->line_info_rec_size;
2054         load_attr.line_info_cnt = prog->line_info_cnt;
2055         load_attr.log_level = prog->log_level;
2056         load_attr.prog_flags = prog->prog_flags;
2057
2058 retry_load:
2059         log_buf = malloc(log_buf_size);
2060         if (!log_buf)
2061                 pr_warning("Alloc log buffer for bpf loader error, continue without log\n");
2062
2063         ret = bpf_load_program_xattr(&load_attr, log_buf, log_buf_size);
2064
2065         if (ret >= 0) {
2066                 if (load_attr.log_level)
2067                         pr_debug("verifier log:\n%s", log_buf);
2068                 *pfd = ret;
2069                 ret = 0;
2070                 goto out;
2071         }
2072
2073         if (errno == ENOSPC) {
2074                 log_buf_size <<= 1;
2075                 free(log_buf);
2076                 goto retry_load;
2077         }
2078         ret = -LIBBPF_ERRNO__LOAD;
2079         cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
2080         pr_warning("load bpf program failed: %s\n", cp);
2081
2082         if (log_buf && log_buf[0] != '\0') {
2083                 ret = -LIBBPF_ERRNO__VERIFY;
2084                 pr_warning("-- BEGIN DUMP LOG ---\n");
2085                 pr_warning("\n%s\n", log_buf);
2086                 pr_warning("-- END LOG --\n");
2087         } else if (load_attr.insns_cnt >= BPF_MAXINSNS) {
2088                 pr_warning("Program too large (%zu insns), at most %d insns\n",
2089                            load_attr.insns_cnt, BPF_MAXINSNS);
2090                 ret = -LIBBPF_ERRNO__PROG2BIG;
2091         } else {
2092                 /* Wrong program type? */
2093                 if (load_attr.prog_type != BPF_PROG_TYPE_KPROBE) {
2094                         int fd;
2095
2096                         load_attr.prog_type = BPF_PROG_TYPE_KPROBE;
2097                         load_attr.expected_attach_type = 0;
2098                         fd = bpf_load_program_xattr(&load_attr, NULL, 0);
2099                         if (fd >= 0) {
2100                                 close(fd);
2101                                 ret = -LIBBPF_ERRNO__PROGTYPE;
2102                                 goto out;
2103                         }
2104                 }
2105
2106                 if (log_buf)
2107                         ret = -LIBBPF_ERRNO__KVER;
2108         }
2109
2110 out:
2111         free(log_buf);
2112         return ret;
2113 }
2114
2115 int
2116 bpf_program__load(struct bpf_program *prog,
2117                   char *license, __u32 kern_version)
2118 {
2119         int err = 0, fd, i;
2120
2121         if (prog->instances.nr < 0 || !prog->instances.fds) {
2122                 if (prog->preprocessor) {
2123                         pr_warning("Internal error: can't load program '%s'\n",
2124                                    prog->section_name);
2125                         return -LIBBPF_ERRNO__INTERNAL;
2126                 }
2127
2128                 prog->instances.fds = malloc(sizeof(int));
2129                 if (!prog->instances.fds) {
2130                         pr_warning("Not enough memory for BPF fds\n");
2131                         return -ENOMEM;
2132                 }
2133                 prog->instances.nr = 1;
2134                 prog->instances.fds[0] = -1;
2135         }
2136
2137         if (!prog->preprocessor) {
2138                 if (prog->instances.nr != 1) {
2139                         pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n",
2140                                    prog->section_name, prog->instances.nr);
2141                 }
2142                 err = load_program(prog, prog->insns, prog->insns_cnt,
2143                                    license, kern_version, &fd);
2144                 if (!err)
2145                         prog->instances.fds[0] = fd;
2146                 goto out;
2147         }
2148
2149         for (i = 0; i < prog->instances.nr; i++) {
2150                 struct bpf_prog_prep_result result;
2151                 bpf_program_prep_t preprocessor = prog->preprocessor;
2152
2153                 memset(&result, 0, sizeof(result));
2154                 err = preprocessor(prog, i, prog->insns,
2155                                    prog->insns_cnt, &result);
2156                 if (err) {
2157                         pr_warning("Preprocessing the %dth instance of program '%s' failed\n",
2158                                    i, prog->section_name);
2159                         goto out;
2160                 }
2161
2162                 if (!result.new_insn_ptr || !result.new_insn_cnt) {
2163                         pr_debug("Skip loading the %dth instance of program '%s'\n",
2164                                  i, prog->section_name);
2165                         prog->instances.fds[i] = -1;
2166                         if (result.pfd)
2167                                 *result.pfd = -1;
2168                         continue;
2169                 }
2170
2171                 err = load_program(prog, result.new_insn_ptr,
2172                                    result.new_insn_cnt,
2173                                    license, kern_version, &fd);
2174
2175                 if (err) {
2176                         pr_warning("Loading the %dth instance of program '%s' failed\n",
2177                                         i, prog->section_name);
2178                         goto out;
2179                 }
2180
2181                 if (result.pfd)
2182                         *result.pfd = fd;
2183                 prog->instances.fds[i] = fd;
2184         }
2185 out:
2186         if (err)
2187                 pr_warning("failed to load program '%s'\n",
2188                            prog->section_name);
2189         zfree(&prog->insns);
2190         prog->insns_cnt = 0;
2191         return err;
2192 }
2193
2194 static bool bpf_program__is_function_storage(struct bpf_program *prog,
2195                                              struct bpf_object *obj)
2196 {
2197         return prog->idx == obj->efile.text_shndx && obj->has_pseudo_calls;
2198 }
2199
2200 static int
2201 bpf_object__load_progs(struct bpf_object *obj, int log_level)
2202 {
2203         size_t i;
2204         int err;
2205
2206         for (i = 0; i < obj->nr_programs; i++) {
2207                 if (bpf_program__is_function_storage(&obj->programs[i], obj))
2208                         continue;
2209                 obj->programs[i].log_level |= log_level;
2210                 err = bpf_program__load(&obj->programs[i],
2211                                         obj->license,
2212                                         obj->kern_version);
2213                 if (err)
2214                         return err;
2215         }
2216         return 0;
2217 }
2218
2219 static bool bpf_prog_type__needs_kver(enum bpf_prog_type type)
2220 {
2221         switch (type) {
2222         case BPF_PROG_TYPE_SOCKET_FILTER:
2223         case BPF_PROG_TYPE_SCHED_CLS:
2224         case BPF_PROG_TYPE_SCHED_ACT:
2225         case BPF_PROG_TYPE_XDP:
2226         case BPF_PROG_TYPE_CGROUP_SKB:
2227         case BPF_PROG_TYPE_CGROUP_SOCK:
2228         case BPF_PROG_TYPE_LWT_IN:
2229         case BPF_PROG_TYPE_LWT_OUT:
2230         case BPF_PROG_TYPE_LWT_XMIT:
2231         case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2232         case BPF_PROG_TYPE_SOCK_OPS:
2233         case BPF_PROG_TYPE_SK_SKB:
2234         case BPF_PROG_TYPE_CGROUP_DEVICE:
2235         case BPF_PROG_TYPE_SK_MSG:
2236         case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2237         case BPF_PROG_TYPE_LIRC_MODE2:
2238         case BPF_PROG_TYPE_SK_REUSEPORT:
2239         case BPF_PROG_TYPE_FLOW_DISSECTOR:
2240         case BPF_PROG_TYPE_UNSPEC:
2241         case BPF_PROG_TYPE_TRACEPOINT:
2242         case BPF_PROG_TYPE_RAW_TRACEPOINT:
2243         case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
2244         case BPF_PROG_TYPE_PERF_EVENT:
2245         case BPF_PROG_TYPE_CGROUP_SYSCTL:
2246                 return false;
2247         case BPF_PROG_TYPE_KPROBE:
2248         default:
2249                 return true;
2250         }
2251 }
2252
2253 static int bpf_object__validate(struct bpf_object *obj, bool needs_kver)
2254 {
2255         if (needs_kver && obj->kern_version == 0) {
2256                 pr_warning("%s doesn't provide kernel version\n",
2257                            obj->path);
2258                 return -LIBBPF_ERRNO__KVERSION;
2259         }
2260         return 0;
2261 }
2262
2263 static struct bpf_object *
2264 __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz,
2265                    bool needs_kver, int flags)
2266 {
2267         struct bpf_object *obj;
2268         int err;
2269
2270         if (elf_version(EV_CURRENT) == EV_NONE) {
2271                 pr_warning("failed to init libelf for %s\n", path);
2272                 return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
2273         }
2274
2275         obj = bpf_object__new(path, obj_buf, obj_buf_sz);
2276         if (IS_ERR(obj))
2277                 return obj;
2278
2279         CHECK_ERR(bpf_object__elf_init(obj), err, out);
2280         CHECK_ERR(bpf_object__check_endianness(obj), err, out);
2281         CHECK_ERR(bpf_object__probe_caps(obj), err, out);
2282         CHECK_ERR(bpf_object__elf_collect(obj, flags), err, out);
2283         CHECK_ERR(bpf_object__collect_reloc(obj), err, out);
2284         CHECK_ERR(bpf_object__validate(obj, needs_kver), err, out);
2285
2286         bpf_object__elf_finish(obj);
2287         return obj;
2288 out:
2289         bpf_object__close(obj);
2290         return ERR_PTR(err);
2291 }
2292
2293 struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr,
2294                                             int flags)
2295 {
2296         /* param validation */
2297         if (!attr->file)
2298                 return NULL;
2299
2300         pr_debug("loading %s\n", attr->file);
2301
2302         return __bpf_object__open(attr->file, NULL, 0,
2303                                   bpf_prog_type__needs_kver(attr->prog_type),
2304                                   flags);
2305 }
2306
2307 struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr)
2308 {
2309         return __bpf_object__open_xattr(attr, 0);
2310 }
2311
2312 struct bpf_object *bpf_object__open(const char *path)
2313 {
2314         struct bpf_object_open_attr attr = {
2315                 .file           = path,
2316                 .prog_type      = BPF_PROG_TYPE_UNSPEC,
2317         };
2318
2319         return bpf_object__open_xattr(&attr);
2320 }
2321
2322 struct bpf_object *bpf_object__open_buffer(void *obj_buf,
2323                                            size_t obj_buf_sz,
2324                                            const char *name)
2325 {
2326         char tmp_name[64];
2327
2328         /* param validation */
2329         if (!obj_buf || obj_buf_sz <= 0)
2330                 return NULL;
2331
2332         if (!name) {
2333                 snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
2334                          (unsigned long)obj_buf,
2335                          (unsigned long)obj_buf_sz);
2336                 name = tmp_name;
2337         }
2338         pr_debug("loading object '%s' from buffer\n", name);
2339
2340         return __bpf_object__open(name, obj_buf, obj_buf_sz, true, true);
2341 }
2342
2343 int bpf_object__unload(struct bpf_object *obj)
2344 {
2345         size_t i;
2346
2347         if (!obj)
2348                 return -EINVAL;
2349
2350         for (i = 0; i < obj->nr_maps; i++)
2351                 zclose(obj->maps[i].fd);
2352
2353         for (i = 0; i < obj->nr_programs; i++)
2354                 bpf_program__unload(&obj->programs[i]);
2355
2356         return 0;
2357 }
2358
2359 int bpf_object__load_xattr(struct bpf_object_load_attr *attr)
2360 {
2361         struct bpf_object *obj;
2362         int err;
2363
2364         if (!attr)
2365                 return -EINVAL;
2366         obj = attr->obj;
2367         if (!obj)
2368                 return -EINVAL;
2369
2370         if (obj->loaded) {
2371                 pr_warning("object should not be loaded twice\n");
2372                 return -EINVAL;
2373         }
2374
2375         obj->loaded = true;
2376
2377         CHECK_ERR(bpf_object__create_maps(obj), err, out);
2378         CHECK_ERR(bpf_object__relocate(obj), err, out);
2379         CHECK_ERR(bpf_object__load_progs(obj, attr->log_level), err, out);
2380
2381         return 0;
2382 out:
2383         bpf_object__unload(obj);
2384         pr_warning("failed to load object '%s'\n", obj->path);
2385         return err;
2386 }
2387
2388 int bpf_object__load(struct bpf_object *obj)
2389 {
2390         struct bpf_object_load_attr attr = {
2391                 .obj = obj,
2392         };
2393
2394         return bpf_object__load_xattr(&attr);
2395 }
2396
2397 static int check_path(const char *path)
2398 {
2399         char *cp, errmsg[STRERR_BUFSIZE];
2400         struct statfs st_fs;
2401         char *dname, *dir;
2402         int err = 0;
2403
2404         if (path == NULL)
2405                 return -EINVAL;
2406
2407         dname = strdup(path);
2408         if (dname == NULL)
2409                 return -ENOMEM;
2410
2411         dir = dirname(dname);
2412         if (statfs(dir, &st_fs)) {
2413                 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
2414                 pr_warning("failed to statfs %s: %s\n", dir, cp);
2415                 err = -errno;
2416         }
2417         free(dname);
2418
2419         if (!err && st_fs.f_type != BPF_FS_MAGIC) {
2420                 pr_warning("specified path %s is not on BPF FS\n", path);
2421                 err = -EINVAL;
2422         }
2423
2424         return err;
2425 }
2426
2427 int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
2428                               int instance)
2429 {
2430         char *cp, errmsg[STRERR_BUFSIZE];
2431         int err;
2432
2433         err = check_path(path);
2434         if (err)
2435                 return err;
2436
2437         if (prog == NULL) {
2438                 pr_warning("invalid program pointer\n");
2439                 return -EINVAL;
2440         }
2441
2442         if (instance < 0 || instance >= prog->instances.nr) {
2443                 pr_warning("invalid prog instance %d of prog %s (max %d)\n",
2444                            instance, prog->section_name, prog->instances.nr);
2445                 return -EINVAL;
2446         }
2447
2448         if (bpf_obj_pin(prog->instances.fds[instance], path)) {
2449                 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
2450                 pr_warning("failed to pin program: %s\n", cp);
2451                 return -errno;
2452         }
2453         pr_debug("pinned program '%s'\n", path);
2454
2455         return 0;
2456 }
2457
2458 int bpf_program__unpin_instance(struct bpf_program *prog, const char *path,
2459                                 int instance)
2460 {
2461         int err;
2462
2463         err = check_path(path);
2464         if (err)
2465                 return err;
2466
2467         if (prog == NULL) {
2468                 pr_warning("invalid program pointer\n");
2469                 return -EINVAL;
2470         }
2471
2472         if (instance < 0 || instance >= prog->instances.nr) {
2473                 pr_warning("invalid prog instance %d of prog %s (max %d)\n",
2474                            instance, prog->section_name, prog->instances.nr);
2475                 return -EINVAL;
2476         }
2477
2478         err = unlink(path);
2479         if (err != 0)
2480                 return -errno;
2481         pr_debug("unpinned program '%s'\n", path);
2482
2483         return 0;
2484 }
2485
2486 static int make_dir(const char *path)
2487 {
2488         char *cp, errmsg[STRERR_BUFSIZE];
2489         int err = 0;
2490
2491         if (mkdir(path, 0700) && errno != EEXIST)
2492                 err = -errno;
2493
2494         if (err) {
2495                 cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg));
2496                 pr_warning("failed to mkdir %s: %s\n", path, cp);
2497         }
2498         return err;
2499 }
2500
2501 int bpf_program__pin(struct bpf_program *prog, const char *path)
2502 {
2503         int i, err;
2504
2505         err = check_path(path);
2506         if (err)
2507                 return err;
2508
2509         if (prog == NULL) {
2510                 pr_warning("invalid program pointer\n");
2511                 return -EINVAL;
2512         }
2513
2514         if (prog->instances.nr <= 0) {
2515                 pr_warning("no instances of prog %s to pin\n",
2516                            prog->section_name);
2517                 return -EINVAL;
2518         }
2519
2520         if (prog->instances.nr == 1) {
2521                 /* don't create subdirs when pinning single instance */
2522                 return bpf_program__pin_instance(prog, path, 0);
2523         }
2524
2525         err = make_dir(path);
2526         if (err)
2527                 return err;
2528
2529         for (i = 0; i < prog->instances.nr; i++) {
2530                 char buf[PATH_MAX];
2531                 int len;
2532
2533                 len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
2534                 if (len < 0) {
2535                         err = -EINVAL;
2536                         goto err_unpin;
2537                 } else if (len >= PATH_MAX) {
2538                         err = -ENAMETOOLONG;
2539                         goto err_unpin;
2540                 }
2541
2542                 err = bpf_program__pin_instance(prog, buf, i);
2543                 if (err)
2544                         goto err_unpin;
2545         }
2546
2547         return 0;
2548
2549 err_unpin:
2550         for (i = i - 1; i >= 0; i--) {
2551                 char buf[PATH_MAX];
2552                 int len;
2553
2554                 len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
2555                 if (len < 0)
2556                         continue;
2557                 else if (len >= PATH_MAX)
2558                         continue;
2559
2560                 bpf_program__unpin_instance(prog, buf, i);
2561         }
2562
2563         rmdir(path);
2564
2565         return err;
2566 }
2567
2568 int bpf_program__unpin(struct bpf_program *prog, const char *path)
2569 {
2570         int i, err;
2571
2572         err = check_path(path);
2573         if (err)
2574                 return err;
2575
2576         if (prog == NULL) {
2577                 pr_warning("invalid program pointer\n");
2578                 return -EINVAL;
2579         }
2580
2581         if (prog->instances.nr <= 0) {
2582                 pr_warning("no instances of prog %s to pin\n",
2583                            prog->section_name);
2584                 return -EINVAL;
2585         }
2586
2587         if (prog->instances.nr == 1) {
2588                 /* don't create subdirs when pinning single instance */
2589                 return bpf_program__unpin_instance(prog, path, 0);
2590         }
2591
2592         for (i = 0; i < prog->instances.nr; i++) {
2593                 char buf[PATH_MAX];
2594                 int len;
2595
2596                 len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
2597                 if (len < 0)
2598                         return -EINVAL;
2599                 else if (len >= PATH_MAX)
2600                         return -ENAMETOOLONG;
2601
2602                 err = bpf_program__unpin_instance(prog, buf, i);
2603                 if (err)
2604                         return err;
2605         }
2606
2607         err = rmdir(path);
2608         if (err)
2609                 return -errno;
2610
2611         return 0;
2612 }
2613
2614 int bpf_map__pin(struct bpf_map *map, const char *path)
2615 {
2616         char *cp, errmsg[STRERR_BUFSIZE];
2617         int err;
2618
2619         err = check_path(path);
2620         if (err)
2621                 return err;
2622
2623         if (map == NULL) {
2624                 pr_warning("invalid map pointer\n");
2625                 return -EINVAL;
2626         }
2627
2628         if (bpf_obj_pin(map->fd, path)) {
2629                 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
2630                 pr_warning("failed to pin map: %s\n", cp);
2631                 return -errno;
2632         }
2633
2634         pr_debug("pinned map '%s'\n", path);
2635
2636         return 0;
2637 }
2638
2639 int bpf_map__unpin(struct bpf_map *map, const char *path)
2640 {
2641         int err;
2642
2643         err = check_path(path);
2644         if (err)
2645                 return err;
2646
2647         if (map == NULL) {
2648                 pr_warning("invalid map pointer\n");
2649                 return -EINVAL;
2650         }
2651
2652         err = unlink(path);
2653         if (err != 0)
2654                 return -errno;
2655         pr_debug("unpinned map '%s'\n", path);
2656
2657         return 0;
2658 }
2659
2660 int bpf_object__pin_maps(struct bpf_object *obj, const char *path)
2661 {
2662         struct bpf_map *map;
2663         int err;
2664
2665         if (!obj)
2666                 return -ENOENT;
2667
2668         if (!obj->loaded) {
2669                 pr_warning("object not yet loaded; load it first\n");
2670                 return -ENOENT;
2671         }
2672
2673         err = make_dir(path);
2674         if (err)
2675                 return err;
2676
2677         bpf_object__for_each_map(map, obj) {
2678                 char buf[PATH_MAX];
2679                 int len;
2680
2681                 len = snprintf(buf, PATH_MAX, "%s/%s", path,
2682                                bpf_map__name(map));
2683                 if (len < 0) {
2684                         err = -EINVAL;
2685                         goto err_unpin_maps;
2686                 } else if (len >= PATH_MAX) {
2687                         err = -ENAMETOOLONG;
2688                         goto err_unpin_maps;
2689                 }
2690
2691                 err = bpf_map__pin(map, buf);
2692                 if (err)
2693                         goto err_unpin_maps;
2694         }
2695
2696         return 0;
2697
2698 err_unpin_maps:
2699         while ((map = bpf_map__prev(map, obj))) {
2700                 char buf[PATH_MAX];
2701                 int len;
2702
2703                 len = snprintf(buf, PATH_MAX, "%s/%s", path,
2704                                bpf_map__name(map));
2705                 if (len < 0)
2706                         continue;
2707                 else if (len >= PATH_MAX)
2708                         continue;
2709
2710                 bpf_map__unpin(map, buf);
2711         }
2712
2713         return err;
2714 }
2715
2716 int bpf_object__unpin_maps(struct bpf_object *obj, const char *path)
2717 {
2718         struct bpf_map *map;
2719         int err;
2720
2721         if (!obj)
2722                 return -ENOENT;
2723
2724         bpf_object__for_each_map(map, obj) {
2725                 char buf[PATH_MAX];
2726                 int len;
2727
2728                 len = snprintf(buf, PATH_MAX, "%s/%s", path,
2729                                bpf_map__name(map));
2730                 if (len < 0)
2731                         return -EINVAL;
2732                 else if (len >= PATH_MAX)
2733                         return -ENAMETOOLONG;
2734
2735                 err = bpf_map__unpin(map, buf);
2736                 if (err)
2737                         return err;
2738         }
2739
2740         return 0;
2741 }
2742
2743 int bpf_object__pin_programs(struct bpf_object *obj, const char *path)
2744 {
2745         struct bpf_program *prog;
2746         int err;
2747
2748         if (!obj)
2749                 return -ENOENT;
2750
2751         if (!obj->loaded) {
2752                 pr_warning("object not yet loaded; load it first\n");
2753                 return -ENOENT;
2754         }
2755
2756         err = make_dir(path);
2757         if (err)
2758                 return err;
2759
2760         bpf_object__for_each_program(prog, obj) {
2761                 char buf[PATH_MAX];
2762                 int len;
2763
2764                 len = snprintf(buf, PATH_MAX, "%s/%s", path,
2765                                prog->pin_name);
2766                 if (len < 0) {
2767                         err = -EINVAL;
2768                         goto err_unpin_programs;
2769                 } else if (len >= PATH_MAX) {
2770                         err = -ENAMETOOLONG;
2771                         goto err_unpin_programs;
2772                 }
2773
2774                 err = bpf_program__pin(prog, buf);
2775                 if (err)
2776                         goto err_unpin_programs;
2777         }
2778
2779         return 0;
2780
2781 err_unpin_programs:
2782         while ((prog = bpf_program__prev(prog, obj))) {
2783                 char buf[PATH_MAX];
2784                 int len;
2785
2786                 len = snprintf(buf, PATH_MAX, "%s/%s", path,
2787                                prog->pin_name);
2788                 if (len < 0)
2789                         continue;
2790                 else if (len >= PATH_MAX)
2791                         continue;
2792
2793                 bpf_program__unpin(prog, buf);
2794         }
2795
2796         return err;
2797 }
2798
2799 int bpf_object__unpin_programs(struct bpf_object *obj, const char *path)
2800 {
2801         struct bpf_program *prog;
2802         int err;
2803
2804         if (!obj)
2805                 return -ENOENT;
2806
2807         bpf_object__for_each_program(prog, obj) {
2808                 char buf[PATH_MAX];
2809                 int len;
2810
2811                 len = snprintf(buf, PATH_MAX, "%s/%s", path,
2812                                prog->pin_name);
2813                 if (len < 0)
2814                         return -EINVAL;
2815                 else if (len >= PATH_MAX)
2816                         return -ENAMETOOLONG;
2817
2818                 err = bpf_program__unpin(prog, buf);
2819                 if (err)
2820                         return err;
2821         }
2822
2823         return 0;
2824 }
2825
2826 int bpf_object__pin(struct bpf_object *obj, const char *path)
2827 {
2828         int err;
2829
2830         err = bpf_object__pin_maps(obj, path);
2831         if (err)
2832                 return err;
2833
2834         err = bpf_object__pin_programs(obj, path);
2835         if (err) {
2836                 bpf_object__unpin_maps(obj, path);
2837                 return err;
2838         }
2839
2840         return 0;
2841 }
2842
2843 void bpf_object__close(struct bpf_object *obj)
2844 {
2845         size_t i;
2846
2847         if (!obj)
2848                 return;
2849
2850         if (obj->clear_priv)
2851                 obj->clear_priv(obj, obj->priv);
2852
2853         bpf_object__elf_finish(obj);
2854         bpf_object__unload(obj);
2855         btf__free(obj->btf);
2856         btf_ext__free(obj->btf_ext);
2857
2858         for (i = 0; i < obj->nr_maps; i++) {
2859                 zfree(&obj->maps[i].name);
2860                 if (obj->maps[i].clear_priv)
2861                         obj->maps[i].clear_priv(&obj->maps[i],
2862                                                 obj->maps[i].priv);
2863                 obj->maps[i].priv = NULL;
2864                 obj->maps[i].clear_priv = NULL;
2865         }
2866
2867         zfree(&obj->sections.rodata);
2868         zfree(&obj->sections.data);
2869         zfree(&obj->maps);
2870         obj->nr_maps = 0;
2871
2872         if (obj->programs && obj->nr_programs) {
2873                 for (i = 0; i < obj->nr_programs; i++)
2874                         bpf_program__exit(&obj->programs[i]);
2875         }
2876         zfree(&obj->programs);
2877
2878         list_del(&obj->list);
2879         free(obj);
2880 }
2881
2882 struct bpf_object *
2883 bpf_object__next(struct bpf_object *prev)
2884 {
2885         struct bpf_object *next;
2886
2887         if (!prev)
2888                 next = list_first_entry(&bpf_objects_list,
2889                                         struct bpf_object,
2890                                         list);
2891         else
2892                 next = list_next_entry(prev, list);
2893
2894         /* Empty list is noticed here so don't need checking on entry. */
2895         if (&next->list == &bpf_objects_list)
2896                 return NULL;
2897
2898         return next;
2899 }
2900
2901 const char *bpf_object__name(struct bpf_object *obj)
2902 {
2903         return obj ? obj->path : ERR_PTR(-EINVAL);
2904 }
2905
2906 unsigned int bpf_object__kversion(struct bpf_object *obj)
2907 {
2908         return obj ? obj->kern_version : 0;
2909 }
2910
2911 struct btf *bpf_object__btf(struct bpf_object *obj)
2912 {
2913         return obj ? obj->btf : NULL;
2914 }
2915
2916 int bpf_object__btf_fd(const struct bpf_object *obj)
2917 {
2918         return obj->btf ? btf__fd(obj->btf) : -1;
2919 }
2920
2921 int bpf_object__set_priv(struct bpf_object *obj, void *priv,
2922                          bpf_object_clear_priv_t clear_priv)
2923 {
2924         if (obj->priv && obj->clear_priv)
2925                 obj->clear_priv(obj, obj->priv);
2926
2927         obj->priv = priv;
2928         obj->clear_priv = clear_priv;
2929         return 0;
2930 }
2931
2932 void *bpf_object__priv(struct bpf_object *obj)
2933 {
2934         return obj ? obj->priv : ERR_PTR(-EINVAL);
2935 }
2936
2937 static struct bpf_program *
2938 __bpf_program__iter(struct bpf_program *p, struct bpf_object *obj, bool forward)
2939 {
2940         size_t nr_programs = obj->nr_programs;
2941         ssize_t idx;
2942
2943         if (!nr_programs)
2944                 return NULL;
2945
2946         if (!p)
2947                 /* Iter from the beginning */
2948                 return forward ? &obj->programs[0] :
2949                         &obj->programs[nr_programs - 1];
2950
2951         if (p->obj != obj) {
2952                 pr_warning("error: program handler doesn't match object\n");
2953                 return NULL;
2954         }
2955
2956         idx = (p - obj->programs) + (forward ? 1 : -1);
2957         if (idx >= obj->nr_programs || idx < 0)
2958                 return NULL;
2959         return &obj->programs[idx];
2960 }
2961
2962 struct bpf_program *
2963 bpf_program__next(struct bpf_program *prev, struct bpf_object *obj)
2964 {
2965         struct bpf_program *prog = prev;
2966
2967         do {
2968                 prog = __bpf_program__iter(prog, obj, true);
2969         } while (prog && bpf_program__is_function_storage(prog, obj));
2970
2971         return prog;
2972 }
2973
2974 struct bpf_program *
2975 bpf_program__prev(struct bpf_program *next, struct bpf_object *obj)
2976 {
2977         struct bpf_program *prog = next;
2978
2979         do {
2980                 prog = __bpf_program__iter(prog, obj, false);
2981         } while (prog && bpf_program__is_function_storage(prog, obj));
2982
2983         return prog;
2984 }
2985
2986 int bpf_program__set_priv(struct bpf_program *prog, void *priv,
2987                           bpf_program_clear_priv_t clear_priv)
2988 {
2989         if (prog->priv && prog->clear_priv)
2990                 prog->clear_priv(prog, prog->priv);
2991
2992         prog->priv = priv;
2993         prog->clear_priv = clear_priv;
2994         return 0;
2995 }
2996
2997 void *bpf_program__priv(struct bpf_program *prog)
2998 {
2999         return prog ? prog->priv : ERR_PTR(-EINVAL);
3000 }
3001
3002 void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex)
3003 {
3004         prog->prog_ifindex = ifindex;
3005 }
3006
3007 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy)
3008 {
3009         const char *title;
3010
3011         title = prog->section_name;
3012         if (needs_copy) {
3013                 title = strdup(title);
3014                 if (!title) {
3015                         pr_warning("failed to strdup program title\n");
3016                         return ERR_PTR(-ENOMEM);
3017                 }
3018         }
3019
3020         return title;
3021 }
3022
3023 int bpf_program__fd(struct bpf_program *prog)
3024 {
3025         return bpf_program__nth_fd(prog, 0);
3026 }
3027
3028 int bpf_program__set_prep(struct bpf_program *prog, int nr_instances,
3029                           bpf_program_prep_t prep)
3030 {
3031         int *instances_fds;
3032
3033         if (nr_instances <= 0 || !prep)
3034                 return -EINVAL;
3035
3036         if (prog->instances.nr > 0 || prog->instances.fds) {
3037                 pr_warning("Can't set pre-processor after loading\n");
3038                 return -EINVAL;
3039         }
3040
3041         instances_fds = malloc(sizeof(int) * nr_instances);
3042         if (!instances_fds) {
3043                 pr_warning("alloc memory failed for fds\n");
3044                 return -ENOMEM;
3045         }
3046
3047         /* fill all fd with -1 */
3048         memset(instances_fds, -1, sizeof(int) * nr_instances);
3049
3050         prog->instances.nr = nr_instances;
3051         prog->instances.fds = instances_fds;
3052         prog->preprocessor = prep;
3053         return 0;
3054 }
3055
3056 int bpf_program__nth_fd(struct bpf_program *prog, int n)
3057 {
3058         int fd;
3059
3060         if (!prog)
3061                 return -EINVAL;
3062
3063         if (n >= prog->instances.nr || n < 0) {
3064                 pr_warning("Can't get the %dth fd from program %s: only %d instances\n",
3065                            n, prog->section_name, prog->instances.nr);
3066                 return -EINVAL;
3067         }
3068
3069         fd = prog->instances.fds[n];
3070         if (fd < 0) {
3071                 pr_warning("%dth instance of program '%s' is invalid\n",
3072                            n, prog->section_name);
3073                 return -ENOENT;
3074         }
3075
3076         return fd;
3077 }
3078
3079 void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type)
3080 {
3081         prog->type = type;
3082 }
3083
3084 static bool bpf_program__is_type(struct bpf_program *prog,
3085                                  enum bpf_prog_type type)
3086 {
3087         return prog ? (prog->type == type) : false;
3088 }
3089
3090 #define BPF_PROG_TYPE_FNS(NAME, TYPE)                   \
3091 int bpf_program__set_##NAME(struct bpf_program *prog)   \
3092 {                                                       \
3093         if (!prog)                                      \
3094                 return -EINVAL;                         \
3095         bpf_program__set_type(prog, TYPE);              \
3096         return 0;                                       \
3097 }                                                       \
3098                                                         \
3099 bool bpf_program__is_##NAME(struct bpf_program *prog)   \
3100 {                                                       \
3101         return bpf_program__is_type(prog, TYPE);        \
3102 }                                                       \
3103
3104 BPF_PROG_TYPE_FNS(socket_filter, BPF_PROG_TYPE_SOCKET_FILTER);
3105 BPF_PROG_TYPE_FNS(kprobe, BPF_PROG_TYPE_KPROBE);
3106 BPF_PROG_TYPE_FNS(sched_cls, BPF_PROG_TYPE_SCHED_CLS);
3107 BPF_PROG_TYPE_FNS(sched_act, BPF_PROG_TYPE_SCHED_ACT);
3108 BPF_PROG_TYPE_FNS(tracepoint, BPF_PROG_TYPE_TRACEPOINT);
3109 BPF_PROG_TYPE_FNS(raw_tracepoint, BPF_PROG_TYPE_RAW_TRACEPOINT);
3110 BPF_PROG_TYPE_FNS(xdp, BPF_PROG_TYPE_XDP);
3111 BPF_PROG_TYPE_FNS(perf_event, BPF_PROG_TYPE_PERF_EVENT);
3112
3113 void bpf_program__set_expected_attach_type(struct bpf_program *prog,
3114                                            enum bpf_attach_type type)
3115 {
3116         prog->expected_attach_type = type;
3117 }
3118
3119 #define BPF_PROG_SEC_IMPL(string, ptype, eatype, is_attachable, atype) \
3120         { string, sizeof(string) - 1, ptype, eatype, is_attachable, atype }
3121
3122 /* Programs that can NOT be attached. */
3123 #define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 0)
3124
3125 /* Programs that can be attached. */
3126 #define BPF_APROG_SEC(string, ptype, atype) \
3127         BPF_PROG_SEC_IMPL(string, ptype, 0, 1, atype)
3128
3129 /* Programs that must specify expected attach type at load time. */
3130 #define BPF_EAPROG_SEC(string, ptype, eatype) \
3131         BPF_PROG_SEC_IMPL(string, ptype, eatype, 1, eatype)
3132
3133 /* Programs that can be attached but attach type can't be identified by section
3134  * name. Kept for backward compatibility.
3135  */
3136 #define BPF_APROG_COMPAT(string, ptype) BPF_PROG_SEC(string, ptype)
3137
3138 static const struct {
3139         const char *sec;
3140         size_t len;
3141         enum bpf_prog_type prog_type;
3142         enum bpf_attach_type expected_attach_type;
3143         int is_attachable;
3144         enum bpf_attach_type attach_type;
3145 } section_names[] = {
3146         BPF_PROG_SEC("socket",                  BPF_PROG_TYPE_SOCKET_FILTER),
3147         BPF_PROG_SEC("kprobe/",                 BPF_PROG_TYPE_KPROBE),
3148         BPF_PROG_SEC("kretprobe/",              BPF_PROG_TYPE_KPROBE),
3149         BPF_PROG_SEC("classifier",              BPF_PROG_TYPE_SCHED_CLS),
3150         BPF_PROG_SEC("action",                  BPF_PROG_TYPE_SCHED_ACT),
3151         BPF_PROG_SEC("tracepoint/",             BPF_PROG_TYPE_TRACEPOINT),
3152         BPF_PROG_SEC("raw_tracepoint/",         BPF_PROG_TYPE_RAW_TRACEPOINT),
3153         BPF_PROG_SEC("xdp",                     BPF_PROG_TYPE_XDP),
3154         BPF_PROG_SEC("perf_event",              BPF_PROG_TYPE_PERF_EVENT),
3155         BPF_PROG_SEC("lwt_in",                  BPF_PROG_TYPE_LWT_IN),
3156         BPF_PROG_SEC("lwt_out",                 BPF_PROG_TYPE_LWT_OUT),
3157         BPF_PROG_SEC("lwt_xmit",                BPF_PROG_TYPE_LWT_XMIT),
3158         BPF_PROG_SEC("lwt_seg6local",           BPF_PROG_TYPE_LWT_SEG6LOCAL),
3159         BPF_APROG_SEC("cgroup_skb/ingress",     BPF_PROG_TYPE_CGROUP_SKB,
3160                                                 BPF_CGROUP_INET_INGRESS),
3161         BPF_APROG_SEC("cgroup_skb/egress",      BPF_PROG_TYPE_CGROUP_SKB,
3162                                                 BPF_CGROUP_INET_EGRESS),
3163         BPF_APROG_COMPAT("cgroup/skb",          BPF_PROG_TYPE_CGROUP_SKB),
3164         BPF_APROG_SEC("cgroup/sock",            BPF_PROG_TYPE_CGROUP_SOCK,
3165                                                 BPF_CGROUP_INET_SOCK_CREATE),
3166         BPF_EAPROG_SEC("cgroup/post_bind4",     BPF_PROG_TYPE_CGROUP_SOCK,
3167                                                 BPF_CGROUP_INET4_POST_BIND),
3168         BPF_EAPROG_SEC("cgroup/post_bind6",     BPF_PROG_TYPE_CGROUP_SOCK,
3169                                                 BPF_CGROUP_INET6_POST_BIND),
3170         BPF_APROG_SEC("cgroup/dev",             BPF_PROG_TYPE_CGROUP_DEVICE,
3171                                                 BPF_CGROUP_DEVICE),
3172         BPF_APROG_SEC("sockops",                BPF_PROG_TYPE_SOCK_OPS,
3173                                                 BPF_CGROUP_SOCK_OPS),
3174         BPF_APROG_SEC("sk_skb/stream_parser",   BPF_PROG_TYPE_SK_SKB,
3175                                                 BPF_SK_SKB_STREAM_PARSER),
3176         BPF_APROG_SEC("sk_skb/stream_verdict",  BPF_PROG_TYPE_SK_SKB,
3177                                                 BPF_SK_SKB_STREAM_VERDICT),
3178         BPF_APROG_COMPAT("sk_skb",              BPF_PROG_TYPE_SK_SKB),
3179         BPF_APROG_SEC("sk_msg",                 BPF_PROG_TYPE_SK_MSG,
3180                                                 BPF_SK_MSG_VERDICT),
3181         BPF_APROG_SEC("lirc_mode2",             BPF_PROG_TYPE_LIRC_MODE2,
3182                                                 BPF_LIRC_MODE2),
3183         BPF_APROG_SEC("flow_dissector",         BPF_PROG_TYPE_FLOW_DISSECTOR,
3184                                                 BPF_FLOW_DISSECTOR),
3185         BPF_EAPROG_SEC("cgroup/bind4",          BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
3186                                                 BPF_CGROUP_INET4_BIND),
3187         BPF_EAPROG_SEC("cgroup/bind6",          BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
3188                                                 BPF_CGROUP_INET6_BIND),
3189         BPF_EAPROG_SEC("cgroup/connect4",       BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
3190                                                 BPF_CGROUP_INET4_CONNECT),
3191         BPF_EAPROG_SEC("cgroup/connect6",       BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
3192                                                 BPF_CGROUP_INET6_CONNECT),
3193         BPF_EAPROG_SEC("cgroup/sendmsg4",       BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
3194                                                 BPF_CGROUP_UDP4_SENDMSG),
3195         BPF_EAPROG_SEC("cgroup/sendmsg6",       BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
3196                                                 BPF_CGROUP_UDP6_SENDMSG),
3197         BPF_EAPROG_SEC("cgroup/sysctl",         BPF_PROG_TYPE_CGROUP_SYSCTL,
3198                                                 BPF_CGROUP_SYSCTL),
3199 };
3200
3201 #undef BPF_PROG_SEC_IMPL
3202 #undef BPF_PROG_SEC
3203 #undef BPF_APROG_SEC
3204 #undef BPF_EAPROG_SEC
3205 #undef BPF_APROG_COMPAT
3206
3207 #define MAX_TYPE_NAME_SIZE 32
3208
3209 static char *libbpf_get_type_names(bool attach_type)
3210 {
3211         int i, len = ARRAY_SIZE(section_names) * MAX_TYPE_NAME_SIZE;
3212         char *buf;
3213
3214         buf = malloc(len);
3215         if (!buf)
3216                 return NULL;
3217
3218         buf[0] = '\0';
3219         /* Forge string buf with all available names */
3220         for (i = 0; i < ARRAY_SIZE(section_names); i++) {
3221                 if (attach_type && !section_names[i].is_attachable)
3222                         continue;
3223
3224                 if (strlen(buf) + strlen(section_names[i].sec) + 2 > len) {
3225                         free(buf);
3226                         return NULL;
3227                 }
3228                 strcat(buf, " ");
3229                 strcat(buf, section_names[i].sec);
3230         }
3231
3232         return buf;
3233 }
3234
3235 int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
3236                              enum bpf_attach_type *expected_attach_type)
3237 {
3238         char *type_names;
3239         int i;
3240
3241         if (!name)
3242                 return -EINVAL;
3243
3244         for (i = 0; i < ARRAY_SIZE(section_names); i++) {
3245                 if (strncmp(name, section_names[i].sec, section_names[i].len))
3246                         continue;
3247                 *prog_type = section_names[i].prog_type;
3248                 *expected_attach_type = section_names[i].expected_attach_type;
3249                 return 0;
3250         }
3251         pr_warning("failed to guess program type based on ELF section name '%s'\n", name);
3252         type_names = libbpf_get_type_names(false);
3253         if (type_names != NULL) {
3254                 pr_info("supported section(type) names are:%s\n", type_names);
3255                 free(type_names);
3256         }
3257
3258         return -EINVAL;
3259 }
3260
3261 int libbpf_attach_type_by_name(const char *name,
3262                                enum bpf_attach_type *attach_type)
3263 {
3264         char *type_names;
3265         int i;
3266
3267         if (!name)
3268                 return -EINVAL;
3269
3270         for (i = 0; i < ARRAY_SIZE(section_names); i++) {
3271                 if (strncmp(name, section_names[i].sec, section_names[i].len))
3272                         continue;
3273                 if (!section_names[i].is_attachable)
3274                         return -EINVAL;
3275                 *attach_type = section_names[i].attach_type;
3276                 return 0;
3277         }
3278         pr_warning("failed to guess attach type based on ELF section name '%s'\n", name);
3279         type_names = libbpf_get_type_names(true);
3280         if (type_names != NULL) {
3281                 pr_info("attachable section(type) names are:%s\n", type_names);
3282                 free(type_names);
3283         }
3284
3285         return -EINVAL;
3286 }
3287
3288 static int
3289 bpf_program__identify_section(struct bpf_program *prog,
3290                               enum bpf_prog_type *prog_type,
3291                               enum bpf_attach_type *expected_attach_type)
3292 {
3293         return libbpf_prog_type_by_name(prog->section_name, prog_type,
3294                                         expected_attach_type);
3295 }
3296
3297 int bpf_map__fd(struct bpf_map *map)
3298 {
3299         return map ? map->fd : -EINVAL;
3300 }
3301
3302 const struct bpf_map_def *bpf_map__def(struct bpf_map *map)
3303 {
3304         return map ? &map->def : ERR_PTR(-EINVAL);
3305 }
3306
3307 const char *bpf_map__name(struct bpf_map *map)
3308 {
3309         return map ? map->name : NULL;
3310 }
3311
3312 __u32 bpf_map__btf_key_type_id(const struct bpf_map *map)
3313 {
3314         return map ? map->btf_key_type_id : 0;
3315 }
3316
3317 __u32 bpf_map__btf_value_type_id(const struct bpf_map *map)
3318 {
3319         return map ? map->btf_value_type_id : 0;
3320 }
3321
3322 int bpf_map__set_priv(struct bpf_map *map, void *priv,
3323                      bpf_map_clear_priv_t clear_priv)
3324 {
3325         if (!map)
3326                 return -EINVAL;
3327
3328         if (map->priv) {
3329                 if (map->clear_priv)
3330                         map->clear_priv(map, map->priv);
3331         }
3332
3333         map->priv = priv;
3334         map->clear_priv = clear_priv;
3335         return 0;
3336 }
3337
3338 void *bpf_map__priv(struct bpf_map *map)
3339 {
3340         return map ? map->priv : ERR_PTR(-EINVAL);
3341 }
3342
3343 bool bpf_map__is_offload_neutral(struct bpf_map *map)
3344 {
3345         return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY;
3346 }
3347
3348 bool bpf_map__is_internal(struct bpf_map *map)
3349 {
3350         return map->libbpf_type != LIBBPF_MAP_UNSPEC;
3351 }
3352
3353 void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
3354 {
3355         map->map_ifindex = ifindex;
3356 }
3357
3358 int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd)
3359 {
3360         if (!bpf_map_type__is_map_in_map(map->def.type)) {
3361                 pr_warning("error: unsupported map type\n");
3362                 return -EINVAL;
3363         }
3364         if (map->inner_map_fd != -1) {
3365                 pr_warning("error: inner_map_fd already specified\n");
3366                 return -EINVAL;
3367         }
3368         map->inner_map_fd = fd;
3369         return 0;
3370 }
3371
3372 static struct bpf_map *
3373 __bpf_map__iter(struct bpf_map *m, struct bpf_object *obj, int i)
3374 {
3375         ssize_t idx;
3376         struct bpf_map *s, *e;
3377
3378         if (!obj || !obj->maps)
3379                 return NULL;
3380
3381         s = obj->maps;
3382         e = obj->maps + obj->nr_maps;
3383
3384         if ((m < s) || (m >= e)) {
3385                 pr_warning("error in %s: map handler doesn't belong to object\n",
3386                            __func__);
3387                 return NULL;
3388         }
3389
3390         idx = (m - obj->maps) + i;
3391         if (idx >= obj->nr_maps || idx < 0)
3392                 return NULL;
3393         return &obj->maps[idx];
3394 }
3395
3396 struct bpf_map *
3397 bpf_map__next(struct bpf_map *prev, struct bpf_object *obj)
3398 {
3399         if (prev == NULL)
3400                 return obj->maps;
3401
3402         return __bpf_map__iter(prev, obj, 1);
3403 }
3404
3405 struct bpf_map *
3406 bpf_map__prev(struct bpf_map *next, struct bpf_object *obj)
3407 {
3408         if (next == NULL) {
3409                 if (!obj->nr_maps)
3410                         return NULL;
3411                 return obj->maps + obj->nr_maps - 1;
3412         }
3413
3414         return __bpf_map__iter(next, obj, -1);
3415 }
3416
3417 struct bpf_map *
3418 bpf_object__find_map_by_name(struct bpf_object *obj, const char *name)
3419 {
3420         struct bpf_map *pos;
3421
3422         bpf_object__for_each_map(pos, obj) {
3423                 if (pos->name && !strcmp(pos->name, name))
3424                         return pos;
3425         }
3426         return NULL;
3427 }
3428
3429 int
3430 bpf_object__find_map_fd_by_name(struct bpf_object *obj, const char *name)
3431 {
3432         return bpf_map__fd(bpf_object__find_map_by_name(obj, name));
3433 }
3434
3435 struct bpf_map *
3436 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset)
3437 {
3438         int i;
3439
3440         for (i = 0; i < obj->nr_maps; i++) {
3441                 if (obj->maps[i].offset == offset)
3442                         return &obj->maps[i];
3443         }
3444         return ERR_PTR(-ENOENT);
3445 }
3446
3447 long libbpf_get_error(const void *ptr)
3448 {
3449         return PTR_ERR_OR_ZERO(ptr);
3450 }
3451
3452 int bpf_prog_load(const char *file, enum bpf_prog_type type,
3453                   struct bpf_object **pobj, int *prog_fd)
3454 {
3455         struct bpf_prog_load_attr attr;
3456
3457         memset(&attr, 0, sizeof(struct bpf_prog_load_attr));
3458         attr.file = file;
3459         attr.prog_type = type;
3460         attr.expected_attach_type = 0;
3461
3462         return bpf_prog_load_xattr(&attr, pobj, prog_fd);
3463 }
3464
3465 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
3466                         struct bpf_object **pobj, int *prog_fd)
3467 {
3468         struct bpf_object_open_attr open_attr = {
3469                 .file           = attr->file,
3470                 .prog_type      = attr->prog_type,
3471         };
3472         struct bpf_program *prog, *first_prog = NULL;
3473         enum bpf_attach_type expected_attach_type;
3474         enum bpf_prog_type prog_type;
3475         struct bpf_object *obj;
3476         struct bpf_map *map;
3477         int err;
3478
3479         if (!attr)
3480                 return -EINVAL;
3481         if (!attr->file)
3482                 return -EINVAL;
3483
3484         obj = bpf_object__open_xattr(&open_attr);
3485         if (IS_ERR_OR_NULL(obj))
3486                 return -ENOENT;
3487
3488         bpf_object__for_each_program(prog, obj) {
3489                 /*
3490                  * If type is not specified, try to guess it based on
3491                  * section name.
3492                  */
3493                 prog_type = attr->prog_type;
3494                 prog->prog_ifindex = attr->ifindex;
3495                 expected_attach_type = attr->expected_attach_type;
3496                 if (prog_type == BPF_PROG_TYPE_UNSPEC) {
3497                         err = bpf_program__identify_section(prog, &prog_type,
3498                                                             &expected_attach_type);
3499                         if (err < 0) {
3500                                 bpf_object__close(obj);
3501                                 return -EINVAL;
3502                         }
3503                 }
3504
3505                 bpf_program__set_type(prog, prog_type);
3506                 bpf_program__set_expected_attach_type(prog,
3507                                                       expected_attach_type);
3508
3509                 prog->log_level = attr->log_level;
3510                 prog->prog_flags = attr->prog_flags;
3511                 if (!first_prog)
3512                         first_prog = prog;
3513         }
3514
3515         bpf_object__for_each_map(map, obj) {
3516                 if (!bpf_map__is_offload_neutral(map))
3517                         map->map_ifindex = attr->ifindex;
3518         }
3519
3520         if (!first_prog) {
3521                 pr_warning("object file doesn't contain bpf program\n");
3522                 bpf_object__close(obj);
3523                 return -ENOENT;
3524         }
3525
3526         err = bpf_object__load(obj);
3527         if (err) {
3528                 bpf_object__close(obj);
3529                 return -EINVAL;
3530         }
3531
3532         *pobj = obj;
3533         *prog_fd = bpf_program__fd(first_prog);
3534         return 0;
3535 }
3536
3537 enum bpf_perf_event_ret
3538 bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
3539                            void **copy_mem, size_t *copy_size,
3540                            bpf_perf_event_print_t fn, void *private_data)
3541 {
3542         struct perf_event_mmap_page *header = mmap_mem;
3543         __u64 data_head = ring_buffer_read_head(header);
3544         __u64 data_tail = header->data_tail;
3545         void *base = ((__u8 *)header) + page_size;
3546         int ret = LIBBPF_PERF_EVENT_CONT;
3547         struct perf_event_header *ehdr;
3548         size_t ehdr_size;
3549
3550         while (data_head != data_tail) {
3551                 ehdr = base + (data_tail & (mmap_size - 1));
3552                 ehdr_size = ehdr->size;
3553
3554                 if (((void *)ehdr) + ehdr_size > base + mmap_size) {
3555                         void *copy_start = ehdr;
3556                         size_t len_first = base + mmap_size - copy_start;
3557                         size_t len_secnd = ehdr_size - len_first;
3558
3559                         if (*copy_size < ehdr_size) {
3560                                 free(*copy_mem);
3561                                 *copy_mem = malloc(ehdr_size);
3562                                 if (!*copy_mem) {
3563                                         *copy_size = 0;
3564                                         ret = LIBBPF_PERF_EVENT_ERROR;
3565                                         break;
3566                                 }
3567                                 *copy_size = ehdr_size;
3568                         }
3569
3570                         memcpy(*copy_mem, copy_start, len_first);
3571                         memcpy(*copy_mem + len_first, base, len_secnd);
3572                         ehdr = *copy_mem;
3573                 }
3574
3575                 ret = fn(ehdr, private_data);
3576                 data_tail += ehdr_size;
3577                 if (ret != LIBBPF_PERF_EVENT_CONT)
3578                         break;
3579         }
3580
3581         ring_buffer_write_tail(header, data_tail);
3582         return ret;
3583 }
3584
3585 struct bpf_prog_info_array_desc {
3586         int     array_offset;   /* e.g. offset of jited_prog_insns */
3587         int     count_offset;   /* e.g. offset of jited_prog_len */
3588         int     size_offset;    /* > 0: offset of rec size,
3589                                  * < 0: fix size of -size_offset
3590                                  */
3591 };
3592
3593 static struct bpf_prog_info_array_desc bpf_prog_info_array_desc[] = {
3594         [BPF_PROG_INFO_JITED_INSNS] = {
3595                 offsetof(struct bpf_prog_info, jited_prog_insns),
3596                 offsetof(struct bpf_prog_info, jited_prog_len),
3597                 -1,
3598         },
3599         [BPF_PROG_INFO_XLATED_INSNS] = {
3600                 offsetof(struct bpf_prog_info, xlated_prog_insns),
3601                 offsetof(struct bpf_prog_info, xlated_prog_len),
3602                 -1,
3603         },
3604         [BPF_PROG_INFO_MAP_IDS] = {
3605                 offsetof(struct bpf_prog_info, map_ids),
3606                 offsetof(struct bpf_prog_info, nr_map_ids),
3607                 -(int)sizeof(__u32),
3608         },
3609         [BPF_PROG_INFO_JITED_KSYMS] = {
3610                 offsetof(struct bpf_prog_info, jited_ksyms),
3611                 offsetof(struct bpf_prog_info, nr_jited_ksyms),
3612                 -(int)sizeof(__u64),
3613         },
3614         [BPF_PROG_INFO_JITED_FUNC_LENS] = {
3615                 offsetof(struct bpf_prog_info, jited_func_lens),
3616                 offsetof(struct bpf_prog_info, nr_jited_func_lens),
3617                 -(int)sizeof(__u32),
3618         },
3619         [BPF_PROG_INFO_FUNC_INFO] = {
3620                 offsetof(struct bpf_prog_info, func_info),
3621                 offsetof(struct bpf_prog_info, nr_func_info),
3622                 offsetof(struct bpf_prog_info, func_info_rec_size),
3623         },
3624         [BPF_PROG_INFO_LINE_INFO] = {
3625                 offsetof(struct bpf_prog_info, line_info),
3626                 offsetof(struct bpf_prog_info, nr_line_info),
3627                 offsetof(struct bpf_prog_info, line_info_rec_size),
3628         },
3629         [BPF_PROG_INFO_JITED_LINE_INFO] = {
3630                 offsetof(struct bpf_prog_info, jited_line_info),
3631                 offsetof(struct bpf_prog_info, nr_jited_line_info),
3632                 offsetof(struct bpf_prog_info, jited_line_info_rec_size),
3633         },
3634         [BPF_PROG_INFO_PROG_TAGS] = {
3635                 offsetof(struct bpf_prog_info, prog_tags),
3636                 offsetof(struct bpf_prog_info, nr_prog_tags),
3637                 -(int)sizeof(__u8) * BPF_TAG_SIZE,
3638         },
3639
3640 };
3641
3642 static __u32 bpf_prog_info_read_offset_u32(struct bpf_prog_info *info, int offset)
3643 {
3644         __u32 *array = (__u32 *)info;
3645
3646         if (offset >= 0)
3647                 return array[offset / sizeof(__u32)];
3648         return -(int)offset;
3649 }
3650
3651 static __u64 bpf_prog_info_read_offset_u64(struct bpf_prog_info *info, int offset)
3652 {
3653         __u64 *array = (__u64 *)info;
3654
3655         if (offset >= 0)
3656                 return array[offset / sizeof(__u64)];
3657         return -(int)offset;
3658 }
3659
3660 static void bpf_prog_info_set_offset_u32(struct bpf_prog_info *info, int offset,
3661                                          __u32 val)
3662 {
3663         __u32 *array = (__u32 *)info;
3664
3665         if (offset >= 0)
3666                 array[offset / sizeof(__u32)] = val;
3667 }
3668
3669 static void bpf_prog_info_set_offset_u64(struct bpf_prog_info *info, int offset,
3670                                          __u64 val)
3671 {
3672         __u64 *array = (__u64 *)info;
3673
3674         if (offset >= 0)
3675                 array[offset / sizeof(__u64)] = val;
3676 }
3677
3678 struct bpf_prog_info_linear *
3679 bpf_program__get_prog_info_linear(int fd, __u64 arrays)
3680 {
3681         struct bpf_prog_info_linear *info_linear;
3682         struct bpf_prog_info info = {};
3683         __u32 info_len = sizeof(info);
3684         __u32 data_len = 0;
3685         int i, err;
3686         void *ptr;
3687
3688         if (arrays >> BPF_PROG_INFO_LAST_ARRAY)
3689                 return ERR_PTR(-EINVAL);
3690
3691         /* step 1: get array dimensions */
3692         err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
3693         if (err) {
3694                 pr_debug("can't get prog info: %s", strerror(errno));
3695                 return ERR_PTR(-EFAULT);
3696         }
3697
3698         /* step 2: calculate total size of all arrays */
3699         for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
3700                 bool include_array = (arrays & (1UL << i)) > 0;
3701                 struct bpf_prog_info_array_desc *desc;
3702                 __u32 count, size;
3703
3704                 desc = bpf_prog_info_array_desc + i;
3705
3706                 /* kernel is too old to support this field */
3707                 if (info_len < desc->array_offset + sizeof(__u32) ||
3708                     info_len < desc->count_offset + sizeof(__u32) ||
3709                     (desc->size_offset > 0 && info_len < desc->size_offset))
3710                         include_array = false;
3711
3712                 if (!include_array) {
3713                         arrays &= ~(1UL << i);  /* clear the bit */
3714                         continue;
3715                 }
3716
3717                 count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
3718                 size  = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
3719
3720                 data_len += count * size;
3721         }
3722
3723         /* step 3: allocate continuous memory */
3724         data_len = roundup(data_len, sizeof(__u64));
3725         info_linear = malloc(sizeof(struct bpf_prog_info_linear) + data_len);
3726         if (!info_linear)
3727                 return ERR_PTR(-ENOMEM);
3728
3729         /* step 4: fill data to info_linear->info */
3730         info_linear->arrays = arrays;
3731         memset(&info_linear->info, 0, sizeof(info));
3732         ptr = info_linear->data;
3733
3734         for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
3735                 struct bpf_prog_info_array_desc *desc;
3736                 __u32 count, size;
3737
3738                 if ((arrays & (1UL << i)) == 0)
3739                         continue;
3740
3741                 desc  = bpf_prog_info_array_desc + i;
3742                 count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
3743                 size  = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
3744                 bpf_prog_info_set_offset_u32(&info_linear->info,
3745                                              desc->count_offset, count);
3746                 bpf_prog_info_set_offset_u32(&info_linear->info,
3747                                              desc->size_offset, size);
3748                 bpf_prog_info_set_offset_u64(&info_linear->info,
3749                                              desc->array_offset,
3750                                              ptr_to_u64(ptr));
3751                 ptr += count * size;
3752         }
3753
3754         /* step 5: call syscall again to get required arrays */
3755         err = bpf_obj_get_info_by_fd(fd, &info_linear->info, &info_len);
3756         if (err) {
3757                 pr_debug("can't get prog info: %s", strerror(errno));
3758                 free(info_linear);
3759                 return ERR_PTR(-EFAULT);
3760         }
3761
3762         /* step 6: verify the data */
3763         for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
3764                 struct bpf_prog_info_array_desc *desc;
3765                 __u32 v1, v2;
3766
3767                 if ((arrays & (1UL << i)) == 0)
3768                         continue;
3769
3770                 desc = bpf_prog_info_array_desc + i;
3771                 v1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
3772                 v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
3773                                                    desc->count_offset);
3774                 if (v1 != v2)
3775                         pr_warning("%s: mismatch in element count\n", __func__);
3776
3777                 v1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
3778                 v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
3779                                                    desc->size_offset);
3780                 if (v1 != v2)
3781                         pr_warning("%s: mismatch in rec size\n", __func__);
3782         }
3783
3784         /* step 7: update info_len and data_len */
3785         info_linear->info_len = sizeof(struct bpf_prog_info);
3786         info_linear->data_len = data_len;
3787
3788         return info_linear;
3789 }
3790
3791 void bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear)
3792 {
3793         int i;
3794
3795         for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
3796                 struct bpf_prog_info_array_desc *desc;
3797                 __u64 addr, offs;
3798
3799                 if ((info_linear->arrays & (1UL << i)) == 0)
3800                         continue;
3801
3802                 desc = bpf_prog_info_array_desc + i;
3803                 addr = bpf_prog_info_read_offset_u64(&info_linear->info,
3804                                                      desc->array_offset);
3805                 offs = addr - ptr_to_u64(info_linear->data);
3806                 bpf_prog_info_set_offset_u64(&info_linear->info,
3807                                              desc->array_offset, offs);
3808         }
3809 }
3810
3811 void bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear)
3812 {
3813         int i;
3814
3815         for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
3816                 struct bpf_prog_info_array_desc *desc;
3817                 __u64 addr, offs;
3818
3819                 if ((info_linear->arrays & (1UL << i)) == 0)
3820                         continue;
3821
3822                 desc = bpf_prog_info_array_desc + i;
3823                 offs = bpf_prog_info_read_offset_u64(&info_linear->info,
3824                                                      desc->array_offset);
3825                 addr = offs + ptr_to_u64(info_linear->data);
3826                 bpf_prog_info_set_offset_u64(&info_linear->info,
3827                                              desc->array_offset, addr);
3828         }
3829 }