include/rdma/uverbs_ioctl.h

   1 /*
   2  * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32
  33 #ifndef _UVERBS_IOCTL_
  34 #define _UVERBS_IOCTL_
  35
  36 #include <rdma/uverbs_types.h>
  37 #include <linux/uaccess.h>
  38 #include <rdma/rdma_user_ioctl.h>
  39 #include <rdma/ib_user_ioctl_verbs.h>
  40 #include <rdma/ib_user_ioctl_cmds.h>
  41
  42 /*
  43  * =======================================
  44  *      Verbs action specifications
  45  * =======================================
  46  */
  47
  48 enum uverbs_attr_type {
  49         UVERBS_ATTR_TYPE_NA,
  50         UVERBS_ATTR_TYPE_PTR_IN,
  51         UVERBS_ATTR_TYPE_PTR_OUT,
  52         UVERBS_ATTR_TYPE_IDR,
  53         UVERBS_ATTR_TYPE_FD,
  54         UVERBS_ATTR_TYPE_ENUM_IN,
  55         UVERBS_ATTR_TYPE_IDRS_ARRAY,
  56 };
  57
  58 enum uverbs_obj_access {
  59         UVERBS_ACCESS_READ,
  60         UVERBS_ACCESS_WRITE,
  61         UVERBS_ACCESS_NEW,
  62         UVERBS_ACCESS_DESTROY
  63 };
  64
  65 /* Specification of a single attribute inside the ioctl message */
  66 /* good size 16 */
  67 struct uverbs_attr_spec {
  68         u8 type;
  69
  70         /*
  71          * Support extending attributes by length. Allow the user to provide
  72          * more bytes than ptr.len, but check that everything after is zero'd
  73          * by the user.
  74          */
  75         u8 zero_trailing:1;
  76         /*
  77          * Valid only for PTR_IN. Allocate and copy the data inside
  78          * the parser
  79          */
  80         u8 alloc_and_copy:1;
  81         u8 mandatory:1;
  82
  83         union {
  84                 struct {
  85                         /* Current known size to kernel */
  86                         u16 len;
  87                         /* User isn't allowed to provide something < min_len */
  88                         u16 min_len;
  89                 } ptr;
  90
  91                 struct {
  92                         /*
  93                          * higher bits mean the namespace and lower bits mean
  94                          * the type id within the namespace.
  95                          */
  96                         u16 obj_type;
  97                         u8 access;
  98                 } obj;
  99
 100                 struct {
 101                         u8 num_elems;
 102                 } enum_def;
 103         } u;
 104
 105         /* This weird split lets us remove some padding */
 106         union {
 107                 struct {
 108                         /*
 109                          * The enum attribute can select one of the attributes
 110                          * contained in the ids array. Currently only PTR_IN
 111                          * attributes are supported in the ids array.
 112                          */
 113                         const struct uverbs_attr_spec *ids;
 114                 } enum_def;
 115
 116                 struct {
 117                         /*
 118                          * higher bits mean the namespace and lower bits mean
 119                          * the type id within the namespace.
 120                          */
 121                         u16                             obj_type;
 122                         u16                             min_len;
 123                         u16                             max_len;
 124                         u8                              access;
 125                 } objs_arr;
 126         } u2;
 127 };
 128
 129 /*
 130  * Information about the API is loaded into a radix tree. For IOCTL we start
 131  * with a tuple of:
 132  *  object_id, attr_id, method_id
 133  *
 134  * Which is a 48 bit value, with most of the bits guaranteed to be zero. Based
 135  * on the current kernel support this is compressed into 16 bit key for the
 136  * radix tree. Since this compression is entirely internal to the kernel the
 137  * below limits can be revised if the kernel gains additional data.
 138  *
 139  * With 64 leafs per node this is a 3 level radix tree.
 140  *
 141  * The tree encodes multiple types, and uses a scheme where OBJ_ID,0,0 returns
 142  * the object slot, and OBJ_ID,METH_ID,0 and returns the method slot.
 143  *
 144  * This also encodes the tables for the write() and write() extended commands
 145  * using the coding
 146  *   OBJ_ID,UVERBS_API_METHOD_IS_WRITE,command #
 147  *   OBJ_ID,UVERBS_API_METHOD_IS_WRITE_EX,command_ex #
 148  * ie the WRITE path is treated as a special method type in the ioctl
 149  * framework.
 150  */
 151 enum uapi_radix_data {
 152         UVERBS_API_NS_FLAG = 1U << UVERBS_ID_NS_SHIFT,
 153
 154         UVERBS_API_ATTR_KEY_BITS = 6,
 155         UVERBS_API_ATTR_KEY_MASK = GENMASK(UVERBS_API_ATTR_KEY_BITS - 1, 0),
 156         UVERBS_API_ATTR_BKEY_LEN = (1 << UVERBS_API_ATTR_KEY_BITS) - 1,
 157         UVERBS_API_WRITE_KEY_NUM = 1 << UVERBS_API_ATTR_KEY_BITS,
 158
 159         UVERBS_API_METHOD_KEY_BITS = 5,
 160         UVERBS_API_METHOD_KEY_SHIFT = UVERBS_API_ATTR_KEY_BITS,
 161         UVERBS_API_METHOD_KEY_NUM_CORE = 22,
 162         UVERBS_API_METHOD_IS_WRITE = 30 << UVERBS_API_METHOD_KEY_SHIFT,
 163         UVERBS_API_METHOD_IS_WRITE_EX = 31 << UVERBS_API_METHOD_KEY_SHIFT,
 164         UVERBS_API_METHOD_KEY_NUM_DRIVER =
 165                 (UVERBS_API_METHOD_IS_WRITE >> UVERBS_API_METHOD_KEY_SHIFT) -
 166                 UVERBS_API_METHOD_KEY_NUM_CORE,
 167         UVERBS_API_METHOD_KEY_MASK = GENMASK(
 168                 UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT - 1,
 169                 UVERBS_API_METHOD_KEY_SHIFT),
 170
 171         UVERBS_API_OBJ_KEY_BITS = 5,
 172         UVERBS_API_OBJ_KEY_SHIFT =
 173                 UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT,
 174         UVERBS_API_OBJ_KEY_NUM_CORE = 24,
 175         UVERBS_API_OBJ_KEY_NUM_DRIVER =
 176                 (1 << UVERBS_API_OBJ_KEY_BITS) - UVERBS_API_OBJ_KEY_NUM_CORE,
 177         UVERBS_API_OBJ_KEY_MASK = GENMASK(31, UVERBS_API_OBJ_KEY_SHIFT),
 178
 179         /* This id guaranteed to not exist in the radix tree */
 180         UVERBS_API_KEY_ERR = 0xFFFFFFFF,
 181 };
 182
 183 static inline __attribute_const__ u32 uapi_key_obj(u32 id)
 184 {
 185         if (id & UVERBS_API_NS_FLAG) {
 186                 id &= ~UVERBS_API_NS_FLAG;
 187                 if (id >= UVERBS_API_OBJ_KEY_NUM_DRIVER)
 188                         return UVERBS_API_KEY_ERR;
 189                 id = id + UVERBS_API_OBJ_KEY_NUM_CORE;
 190         } else {
 191                 if (id >= UVERBS_API_OBJ_KEY_NUM_CORE)
 192                         return UVERBS_API_KEY_ERR;
 193         }
 194
 195         return id << UVERBS_API_OBJ_KEY_SHIFT;
 196 }
 197
 198 static inline __attribute_const__ bool uapi_key_is_object(u32 key)
 199 {
 200         return (key & ~UVERBS_API_OBJ_KEY_MASK) == 0;
 201 }
 202
 203 static inline __attribute_const__ u32 uapi_key_ioctl_method(u32 id)
 204 {
 205         if (id & UVERBS_API_NS_FLAG) {
 206                 id &= ~UVERBS_API_NS_FLAG;
 207                 if (id >= UVERBS_API_METHOD_KEY_NUM_DRIVER)
 208                         return UVERBS_API_KEY_ERR;
 209                 id = id + UVERBS_API_METHOD_KEY_NUM_CORE;
 210         } else {
 211                 id++;
 212                 if (id >= UVERBS_API_METHOD_KEY_NUM_CORE)
 213                         return UVERBS_API_KEY_ERR;
 214         }
 215
 216         return id << UVERBS_API_METHOD_KEY_SHIFT;
 217 }
 218
 219 static inline __attribute_const__ u32 uapi_key_write_method(u32 id)
 220 {
 221         if (id >= UVERBS_API_WRITE_KEY_NUM)
 222                 return UVERBS_API_KEY_ERR;
 223         return UVERBS_API_METHOD_IS_WRITE | id;
 224 }
 225
 226 static inline __attribute_const__ u32 uapi_key_write_ex_method(u32 id)
 227 {
 228         if (id >= UVERBS_API_WRITE_KEY_NUM)
 229                 return UVERBS_API_KEY_ERR;
 230         return UVERBS_API_METHOD_IS_WRITE_EX | id;
 231 }
 232
 233 static inline __attribute_const__ u32
 234 uapi_key_attr_to_ioctl_method(u32 attr_key)
 235 {
 236         return attr_key &
 237                (UVERBS_API_OBJ_KEY_MASK | UVERBS_API_METHOD_KEY_MASK);
 238 }
 239
 240 static inline __attribute_const__ bool uapi_key_is_ioctl_method(u32 key)
 241 {
 242         unsigned int method = key & UVERBS_API_METHOD_KEY_MASK;
 243
 244         return method != 0 && method < UVERBS_API_METHOD_IS_WRITE &&
 245                (key & UVERBS_API_ATTR_KEY_MASK) == 0;
 246 }
 247
 248 static inline __attribute_const__ bool uapi_key_is_write_method(u32 key)
 249 {
 250         return (key & UVERBS_API_METHOD_KEY_MASK) == UVERBS_API_METHOD_IS_WRITE;
 251 }
 252
 253 static inline __attribute_const__ bool uapi_key_is_write_ex_method(u32 key)
 254 {
 255         return (key & UVERBS_API_METHOD_KEY_MASK) ==
 256                UVERBS_API_METHOD_IS_WRITE_EX;
 257 }
 258
 259 static inline __attribute_const__ u32 uapi_key_attrs_start(u32 ioctl_method_key)
 260 {
 261         /* 0 is the method slot itself */
 262         return ioctl_method_key + 1;
 263 }
 264
 265 static inline __attribute_const__ u32 uapi_key_attr(u32 id)
 266 {
 267         /*
 268          * The attr is designed to fit in the typical single radix tree node
 269          * of 64 entries. Since allmost all methods have driver attributes we
 270          * organize things so that the driver and core attributes interleave to
 271          * reduce the length of the attributes array in typical cases.
 272          */
 273         if (id & UVERBS_API_NS_FLAG) {
 274                 id &= ~UVERBS_API_NS_FLAG;
 275                 id++;
 276                 if (id >= 1 << (UVERBS_API_ATTR_KEY_BITS - 1))
 277                         return UVERBS_API_KEY_ERR;
 278                 id = (id << 1) | 0;
 279         } else {
 280                 if (id >= 1 << (UVERBS_API_ATTR_KEY_BITS - 1))
 281                         return UVERBS_API_KEY_ERR;
 282                 id = (id << 1) | 1;
 283         }
 284
 285         return id;
 286 }
 287
 288 /* Only true for ioctl methods */
 289 static inline __attribute_const__ bool uapi_key_is_attr(u32 key)
 290 {
 291         unsigned int method = key & UVERBS_API_METHOD_KEY_MASK;
 292
 293         return method != 0 && method < UVERBS_API_METHOD_IS_WRITE &&
 294                (key & UVERBS_API_ATTR_KEY_MASK) != 0;
 295 }
 296
 297 /*
 298  * This returns a value in the range [0 to UVERBS_API_ATTR_BKEY_LEN),
 299  * basically it undoes the reservation of 0 in the ID numbering. attr_key
 300  * must already be masked with UVERBS_API_ATTR_KEY_MASK, or be the output of
 301  * uapi_key_attr().
 302  */
 303 static inline __attribute_const__ u32 uapi_bkey_attr(u32 attr_key)
 304 {
 305         return attr_key - 1;
 306 }
 307
 308 static inline __attribute_const__ u32 uapi_bkey_to_key_attr(u32 attr_bkey)
 309 {
 310         return attr_bkey + 1;
 311 }
 312
 313 /*
 314  * =======================================
 315  *      Verbs definitions
 316  * =======================================
 317  */
 318
 319 struct uverbs_attr_def {
 320         u16                           id;
 321         struct uverbs_attr_spec       attr;
 322 };
 323
 324 struct uverbs_method_def {
 325         u16                                  id;
 326         /* Combination of bits from enum UVERBS_ACTION_FLAG_XXXX */
 327         u32                                  flags;
 328         size_t                               num_attrs;
 329         const struct uverbs_attr_def * const (*attrs)[];
 330         int (*handler)(struct uverbs_attr_bundle *attrs);
 331 };
 332
 333 struct uverbs_object_def {
 334         u16                                      id;
 335         const struct uverbs_obj_type            *type_attrs;
 336         size_t                                   num_methods;
 337         const struct uverbs_method_def * const (*methods)[];
 338 };
 339
 340 enum uapi_definition_kind {
 341         UAPI_DEF_END = 0,
 342         UAPI_DEF_OBJECT_START,
 343         UAPI_DEF_WRITE,
 344         UAPI_DEF_CHAIN_OBJ_TREE,
 345         UAPI_DEF_CHAIN,
 346         UAPI_DEF_IS_SUPPORTED_FUNC,
 347         UAPI_DEF_IS_SUPPORTED_DEV_FN,
 348 };
 349
 350 enum uapi_definition_scope {
 351         UAPI_SCOPE_OBJECT = 1,
 352         UAPI_SCOPE_METHOD = 2,
 353 };
 354
 355 struct uapi_definition {
 356         u8 kind;
 357         u8 scope;
 358         union {
 359                 struct {
 360                         u16 object_id;
 361                 } object_start;
 362                 struct {
 363                         u8 is_ex;
 364                         u16 command_num;
 365                 } write;
 366         };
 367
 368         union {
 369                 bool (*func_is_supported)(struct ib_device *device);
 370                 int (*func_write)(struct uverbs_attr_bundle *attrs,
 371                                   const char __user *buf, int in_len,
 372                                   int out_len);
 373                 int (*func_write_ex)(struct uverbs_attr_bundle *attrs,
 374                                      struct ib_udata *ucore,
 375                                      struct ib_udata *uhw);
 376                 const struct uapi_definition *chain;
 377                 const struct uverbs_object_def *chain_obj_tree;
 378                 size_t needs_fn_offset;
 379         };
 380 };
 381
 382 /* Define things connected to object_id */
 383 #define DECLARE_UVERBS_OBJECT(_object_id, ...)                                 \
 384         {                                                                      \
 385                 .kind = UAPI_DEF_OBJECT_START,                                 \
 386                 .object_start = { .object_id = _object_id },                   \
 387         },                                                                     \
 388                 ##__VA_ARGS__
 389
 390 /* Use in a var_args of DECLARE_UVERBS_OBJECT */
 391 #define DECLARE_UVERBS_WRITE(_command_num, _func, ...)                         \
 392         {                                                                      \
 393                 .kind = UAPI_DEF_WRITE,                                        \
 394                 .scope = UAPI_SCOPE_OBJECT,                                    \
 395                 .write = { .is_ex = 0, .command_num = _command_num },          \
 396                 .func_write = _func,                                           \
 397         },                                                                     \
 398                 ##__VA_ARGS__
 399
 400 /* Use in a var_args of DECLARE_UVERBS_OBJECT */
 401 #define DECLARE_UVERBS_WRITE_EX(_command_num, _func, ...)                      \
 402         {                                                                      \
 403                 .kind = UAPI_DEF_WRITE,                                        \
 404                 .scope = UAPI_SCOPE_OBJECT,                                    \
 405                 .write = { .is_ex = 1, .command_num = _command_num },          \
 406                 .func_write_ex = _func,                                        \
 407         },                                                                     \
 408                 ##__VA_ARGS__
 409
 410 /*
 411  * Object is only supported if the function pointer named ibdev_fn in struct
 412  * ib_device is not NULL.
 413  */
 414 #define UAPI_DEF_OBJ_NEEDS_FN(ibdev_fn)                                        \
 415         {                                                                      \
 416                 .kind = UAPI_DEF_IS_SUPPORTED_DEV_FN,                          \
 417                 .scope = UAPI_SCOPE_OBJECT,                                    \
 418                 .needs_fn_offset =                                             \
 419                         offsetof(struct ib_device, ibdev_fn) +                 \
 420                         BUILD_BUG_ON_ZERO(                                     \
 421                                 sizeof(((struct ib_device *)0)->ibdev_fn) !=   \
 422                                 sizeof(void *)),                               \
 423         }
 424
 425 /*
 426  * Method is only supported if the function pointer named ibdev_fn in struct
 427  * ib_device is not NULL.
 428  */
 429 #define UAPI_DEF_METHOD_NEEDS_FN(ibdev_fn)                                     \
 430         {                                                                      \
 431                 .kind = UAPI_DEF_IS_SUPPORTED_DEV_FN,                          \
 432                 .scope = UAPI_SCOPE_METHOD,                                    \
 433                 .needs_fn_offset =                                             \
 434                         offsetof(struct ib_device, ibdev_fn) +                 \
 435                         BUILD_BUG_ON_ZERO(                                     \
 436                                 sizeof(((struct ib_device *)0)->ibdev_fn) !=   \
 437                                 sizeof(void *)),                               \
 438         }
 439
 440 /* Call a function to determine if the entire object is supported or not */
 441 #define UAPI_DEF_IS_OBJ_SUPPORTED(_func)                                       \
 442         {                                                                      \
 443                 .kind = UAPI_DEF_IS_SUPPORTED_FUNC,                            \
 444                 .scope = UAPI_SCOPE_OBJECT, .func_is_supported = _func,        \
 445         }
 446
 447 /* Include another struct uapi_definition in this one */
 448 #define UAPI_DEF_CHAIN(_def_var)                                               \
 449         {                                                                      \
 450                 .kind = UAPI_DEF_CHAIN, .chain = _def_var,                     \
 451         }
 452
 453 /* Temporary until the tree base description is replaced */
 454 #define UAPI_DEF_CHAIN_OBJ_TREE(_object_enum, _object_ptr)                     \
 455         {                                                                      \
 456                 .kind = UAPI_DEF_CHAIN_OBJ_TREE,                               \
 457                 .object_start = { .object_id = _object_enum },                 \
 458                 .chain_obj_tree = _object_ptr,                                 \
 459         }
 460 #define UAPI_DEF_CHAIN_OBJ_TREE_NAMED(_object_enum, ...)                       \
 461         UAPI_DEF_CHAIN_OBJ_TREE(_object_enum, &UVERBS_OBJECT(_object_enum)),   \
 462                 ##__VA_ARGS__
 463
 464 /*
 465  * =======================================
 466  *      Attribute Specifications
 467  * =======================================
 468  */
 469
 470 #define UVERBS_ATTR_SIZE(_min_len, _len)                        \
 471         .u.ptr.min_len = _min_len, .u.ptr.len = _len
 472
 473 #define UVERBS_ATTR_NO_DATA() UVERBS_ATTR_SIZE(0, 0)
 474
 475 /*
 476  * Specifies a uapi structure that cannot be extended. The user must always
 477  * supply the whole structure and nothing more. The structure must be declared
 478  * in a header under include/uapi/rdma.
 479  */
 480 #define UVERBS_ATTR_TYPE(_type)                                 \
 481         .u.ptr.min_len = sizeof(_type), .u.ptr.len = sizeof(_type)
 482 /*
 483  * Specifies a uapi structure where the user must provide at least up to
 484  * member 'last'.  Anything after last and up until the end of the structure
 485  * can be non-zero, anything longer than the end of the structure must be
 486  * zero. The structure must be declared in a header under include/uapi/rdma.
 487  */
 488 #define UVERBS_ATTR_STRUCT(_type, _last)                                       \
 489         .zero_trailing = 1,                                                    \
 490         UVERBS_ATTR_SIZE(((uintptr_t)(&((_type *)0)->_last + 1)),              \
 491                          sizeof(_type))
 492 /*
 493  * Specifies at least min_len bytes must be passed in, but the amount can be
 494  * larger, up to the protocol maximum size. No check for zeroing is done.
 495  */
 496 #define UVERBS_ATTR_MIN_SIZE(_min_len) UVERBS_ATTR_SIZE(_min_len, USHRT_MAX)
 497
 498 /* Must be used in the '...' of any UVERBS_ATTR */
 499 #define UA_ALLOC_AND_COPY .alloc_and_copy = 1
 500 #define UA_MANDATORY .mandatory = 1
 501 #define UA_OPTIONAL .mandatory = 0
 502
 503 /*
 504  * min_len must be bigger than 0 and _max_len must be smaller than 4095.  Only
 505  * READ\WRITE accesses are supported.
 506  */
 507 #define UVERBS_ATTR_IDRS_ARR(_attr_id, _idr_type, _access, _min_len, _max_len, \
 508                              ...)                                              \
 509         (&(const struct uverbs_attr_def){                                      \
 510                 .id = (_attr_id) +                                             \
 511                       BUILD_BUG_ON_ZERO((_min_len) == 0 ||                     \
 512                                         (_max_len) >                           \
 513                                                 PAGE_SIZE / sizeof(void *) ||  \
 514                                         (_min_len) > (_max_len) ||             \
 515                                         (_access) == UVERBS_ACCESS_NEW ||      \
 516                                         (_access) == UVERBS_ACCESS_DESTROY),   \
 517                 .attr = { .type = UVERBS_ATTR_TYPE_IDRS_ARRAY,                 \
 518                           .u2.objs_arr.obj_type = _idr_type,                   \
 519                           .u2.objs_arr.access = _access,                       \
 520                           .u2.objs_arr.min_len = _min_len,                     \
 521                           .u2.objs_arr.max_len = _max_len,                     \
 522                           __VA_ARGS__ } })
 523
 524 #define UVERBS_ATTR_IDR(_attr_id, _idr_type, _access, ...)                     \
 525         (&(const struct uverbs_attr_def){                                      \
 526                 .id = _attr_id,                                                \
 527                 .attr = { .type = UVERBS_ATTR_TYPE_IDR,                        \
 528                           .u.obj.obj_type = _idr_type,                         \
 529                           .u.obj.access = _access,                             \
 530                           __VA_ARGS__ } })
 531
 532 #define UVERBS_ATTR_FD(_attr_id, _fd_type, _access, ...)                       \
 533         (&(const struct uverbs_attr_def){                                      \
 534                 .id = (_attr_id) +                                             \
 535                       BUILD_BUG_ON_ZERO((_access) != UVERBS_ACCESS_NEW &&      \
 536                                         (_access) != UVERBS_ACCESS_READ),      \
 537                 .attr = { .type = UVERBS_ATTR_TYPE_FD,                         \
 538                           .u.obj.obj_type = _fd_type,                          \
 539                           .u.obj.access = _access,                             \
 540                           __VA_ARGS__ } })
 541
 542 #define UVERBS_ATTR_PTR_IN(_attr_id, _type, ...)                               \
 543         (&(const struct uverbs_attr_def){                                      \
 544                 .id = _attr_id,                                                \
 545                 .attr = { .type = UVERBS_ATTR_TYPE_PTR_IN,                     \
 546                           _type,                                               \
 547                           __VA_ARGS__ } })
 548
 549 #define UVERBS_ATTR_PTR_OUT(_attr_id, _type, ...)                              \
 550         (&(const struct uverbs_attr_def){                                      \
 551                 .id = _attr_id,                                                \
 552                 .attr = { .type = UVERBS_ATTR_TYPE_PTR_OUT,                    \
 553                           _type,                                               \
 554                           __VA_ARGS__ } })
 555
 556 /* _enum_arry should be a 'static const union uverbs_attr_spec[]' */
 557 #define UVERBS_ATTR_ENUM_IN(_attr_id, _enum_arr, ...)                          \
 558         (&(const struct uverbs_attr_def){                                      \
 559                 .id = _attr_id,                                                \
 560                 .attr = { .type = UVERBS_ATTR_TYPE_ENUM_IN,                    \
 561                           .u2.enum_def.ids = _enum_arr,                        \
 562                           .u.enum_def.num_elems = ARRAY_SIZE(_enum_arr),       \
 563                           __VA_ARGS__ },                                       \
 564         })
 565
 566 /* An input value that is a member in the enum _enum_type. */
 567 #define UVERBS_ATTR_CONST_IN(_attr_id, _enum_type, ...)                        \
 568         UVERBS_ATTR_PTR_IN(                                                    \
 569                 _attr_id,                                                      \
 570                 UVERBS_ATTR_SIZE(                                              \
 571                         sizeof(u64) + BUILD_BUG_ON_ZERO(!sizeof(_enum_type)),  \
 572                         sizeof(u64)),                                          \
 573                 __VA_ARGS__)
 574
 575 /*
 576  * An input value that is a bitwise combination of values of _enum_type.
 577  * This permits the flag value to be passed as either a u32 or u64, it must
 578  * be retrieved via uverbs_get_flag().
 579  */
 580 #define UVERBS_ATTR_FLAGS_IN(_attr_id, _enum_type, ...)                        \
 581         UVERBS_ATTR_PTR_IN(                                                    \
 582                 _attr_id,                                                      \
 583                 UVERBS_ATTR_SIZE(sizeof(u32) + BUILD_BUG_ON_ZERO(              \
 584                                                        !sizeof(_enum_type *)), \
 585                                  sizeof(u64)),                                 \
 586                 __VA_ARGS__)
 587
 588 /*
 589  * This spec is used in order to pass information to the hardware driver in a
 590  * legacy way. Every verb that could get driver specific data should get this
 591  * spec.
 592  */
 593 #define UVERBS_ATTR_UHW()                                                      \
 594         UVERBS_ATTR_PTR_IN(UVERBS_ATTR_UHW_IN,                                 \
 595                            UVERBS_ATTR_MIN_SIZE(0),                            \
 596                            UA_OPTIONAL),                                       \
 597         UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_UHW_OUT,                               \
 598                             UVERBS_ATTR_MIN_SIZE(0),                           \
 599                             UA_OPTIONAL)
 600
 601 /* =================================================
 602  *              Parsing infrastructure
 603  * =================================================
 604  */
 605
 606
 607 struct uverbs_ptr_attr {
 608         /*
 609          * If UVERBS_ATTR_SPEC_F_ALLOC_AND_COPY is set then the 'ptr' is
 610          * used.
 611          */
 612         union {
 613                 void *ptr;
 614                 u64 data;
 615         };
 616         u16             len;
 617         u16             uattr_idx;
 618         u8              enum_id;
 619 };
 620
 621 struct uverbs_obj_attr {
 622         struct ib_uobject               *uobject;
 623         const struct uverbs_api_attr    *attr_elm;
 624 };
 625
 626 struct uverbs_objs_arr_attr {
 627         struct ib_uobject **uobjects;
 628         u16 len;
 629 };
 630
 631 struct uverbs_attr {
 632         union {
 633                 struct uverbs_ptr_attr  ptr_attr;
 634                 struct uverbs_obj_attr  obj_attr;
 635                 struct uverbs_objs_arr_attr objs_arr_attr;
 636         };
 637 };
 638
 639 struct uverbs_attr_bundle {
 640         struct ib_uverbs_file *ufile;
 641         DECLARE_BITMAP(attr_present, UVERBS_API_ATTR_BKEY_LEN);
 642         struct uverbs_attr attrs[];
 643 };
 644
 645 static inline bool uverbs_attr_is_valid(const struct uverbs_attr_bundle *attrs_bundle,
 646                                         unsigned int idx)
 647 {
 648         return test_bit(uapi_bkey_attr(uapi_key_attr(idx)),
 649                         attrs_bundle->attr_present);
 650 }
 651
 652 #define IS_UVERBS_COPY_ERR(_ret)                ((_ret) && (_ret) != -ENOENT)
 653
 654 static inline const struct uverbs_attr *uverbs_attr_get(const struct uverbs_attr_bundle *attrs_bundle,
 655                                                         u16 idx)
 656 {
 657         if (!uverbs_attr_is_valid(attrs_bundle, idx))
 658                 return ERR_PTR(-ENOENT);
 659
 660         return &attrs_bundle->attrs[uapi_bkey_attr(uapi_key_attr(idx))];
 661 }
 662
 663 static inline int uverbs_attr_get_enum_id(const struct uverbs_attr_bundle *attrs_bundle,
 664                                           u16 idx)
 665 {
 666         const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
 667
 668         if (IS_ERR(attr))
 669                 return PTR_ERR(attr);
 670
 671         return attr->ptr_attr.enum_id;
 672 }
 673
 674 static inline void *uverbs_attr_get_obj(const struct uverbs_attr_bundle *attrs_bundle,
 675                                         u16 idx)
 676 {
 677         const struct uverbs_attr *attr;
 678
 679         attr = uverbs_attr_get(attrs_bundle, idx);
 680         if (IS_ERR(attr))
 681                 return ERR_CAST(attr);
 682
 683         return attr->obj_attr.uobject->object;
 684 }
 685
 686 static inline struct ib_uobject *uverbs_attr_get_uobject(const struct uverbs_attr_bundle *attrs_bundle,
 687                                                          u16 idx)
 688 {
 689         const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
 690
 691         if (IS_ERR(attr))
 692                 return ERR_CAST(attr);
 693
 694         return attr->obj_attr.uobject;
 695 }
 696
 697 static inline int
 698 uverbs_attr_get_len(const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
 699 {
 700         const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
 701
 702         if (IS_ERR(attr))
 703                 return PTR_ERR(attr);
 704
 705         return attr->ptr_attr.len;
 706 }
 707
 708 /**
 709  * uverbs_attr_get_uobjs_arr() - Provides array's properties for attribute for
 710  * UVERBS_ATTR_TYPE_IDRS_ARRAY.
 711  * @arr: Returned pointer to array of pointers for uobjects or NULL if
 712  *       the attribute isn't provided.
 713  *
 714  * Return: The array length or 0 if no attribute was provided.
 715  */
 716 static inline int uverbs_attr_get_uobjs_arr(
 717         const struct uverbs_attr_bundle *attrs_bundle, u16 attr_idx,
 718         struct ib_uobject ***arr)
 719 {
 720         const struct uverbs_attr *attr =
 721                         uverbs_attr_get(attrs_bundle, attr_idx);
 722
 723         if (IS_ERR(attr)) {
 724                 *arr = NULL;
 725                 return 0;
 726         }
 727
 728         *arr = attr->objs_arr_attr.uobjects;
 729
 730         return attr->objs_arr_attr.len;
 731 }
 732
 733 static inline bool uverbs_attr_ptr_is_inline(const struct uverbs_attr *attr)
 734 {
 735         return attr->ptr_attr.len <= sizeof(attr->ptr_attr.data);
 736 }
 737
 738 static inline void *uverbs_attr_get_alloced_ptr(
 739         const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
 740 {
 741         const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
 742
 743         if (IS_ERR(attr))
 744                 return (void *)attr;
 745
 746         return uverbs_attr_ptr_is_inline(attr) ? (void *)&attr->ptr_attr.data :
 747                                                  attr->ptr_attr.ptr;
 748 }
 749
 750 static inline int _uverbs_copy_from(void *to,
 751                                     const struct uverbs_attr_bundle *attrs_bundle,
 752                                     size_t idx,
 753                                     size_t size)
 754 {
 755         const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
 756
 757         if (IS_ERR(attr))
 758                 return PTR_ERR(attr);
 759
 760         /*
 761          * Validation ensures attr->ptr_attr.len >= size. If the caller is
 762          * using UVERBS_ATTR_SPEC_F_MIN_SZ_OR_ZERO then it must call
 763          * uverbs_copy_from_or_zero.
 764          */
 765         if (unlikely(size < attr->ptr_attr.len))
 766                 return -EINVAL;
 767
 768         if (uverbs_attr_ptr_is_inline(attr))
 769                 memcpy(to, &attr->ptr_attr.data, attr->ptr_attr.len);
 770         else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
 771                                 attr->ptr_attr.len))
 772                 return -EFAULT;
 773
 774         return 0;
 775 }
 776
 777 static inline int _uverbs_copy_from_or_zero(void *to,
 778                                             const struct uverbs_attr_bundle *attrs_bundle,
 779                                             size_t idx,
 780                                             size_t size)
 781 {
 782         const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
 783         size_t min_size;
 784
 785         if (IS_ERR(attr))
 786                 return PTR_ERR(attr);
 787
 788         min_size = min_t(size_t, size, attr->ptr_attr.len);
 789
 790         if (uverbs_attr_ptr_is_inline(attr))
 791                 memcpy(to, &attr->ptr_attr.data, min_size);
 792         else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
 793                                 min_size))
 794                 return -EFAULT;
 795
 796         if (size > min_size)
 797                 memset(to + min_size, 0, size - min_size);
 798
 799         return 0;
 800 }
 801
 802 #define uverbs_copy_from(to, attrs_bundle, idx)                               \
 803         _uverbs_copy_from(to, attrs_bundle, idx, sizeof(*to))
 804
 805 #define uverbs_copy_from_or_zero(to, attrs_bundle, idx)                       \
 806         _uverbs_copy_from_or_zero(to, attrs_bundle, idx, sizeof(*to))
 807
 808 static inline struct ib_ucontext *
 809 ib_uverbs_get_ucontext(const struct uverbs_attr_bundle *attrs)
 810 {
 811         return ib_uverbs_get_ucontext_file(attrs->ufile);
 812 }
 813
 814 #if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS)
 815 int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
 816                        size_t idx, u64 allowed_bits);
 817 int uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
 818                        size_t idx, u64 allowed_bits);
 819 int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle, size_t idx,
 820                    const void *from, size_t size);
 821 __malloc void *_uverbs_alloc(struct uverbs_attr_bundle *bundle, size_t size,
 822                              gfp_t flags);
 823
 824 static inline __malloc void *uverbs_alloc(struct uverbs_attr_bundle *bundle,
 825                                           size_t size)
 826 {
 827         return _uverbs_alloc(bundle, size, GFP_KERNEL);
 828 }
 829
 830 static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle,
 831                                            size_t size)
 832 {
 833         return _uverbs_alloc(bundle, size, GFP_KERNEL | __GFP_ZERO);
 834 }
 835 int _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
 836                       size_t idx, s64 lower_bound, u64 upper_bound,
 837                       s64 *def_val);
 838 #else
 839 static inline int
 840 uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
 841                    size_t idx, u64 allowed_bits)
 842 {
 843         return -EINVAL;
 844 }
 845 static inline int
 846 uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
 847                    size_t idx, u64 allowed_bits)
 848 {
 849         return -EINVAL;
 850 }
 851 static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
 852                                  size_t idx, const void *from, size_t size)
 853 {
 854         return -EINVAL;
 855 }
 856 static inline __malloc void *uverbs_alloc(struct uverbs_attr_bundle *bundle,
 857                                           size_t size)
 858 {
 859         return ERR_PTR(-EINVAL);
 860 }
 861 static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle,
 862                                            size_t size)
 863 {
 864         return ERR_PTR(-EINVAL);
 865 }
 866 static inline int
 867 _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
 868                   size_t idx, s64 lower_bound, u64 upper_bound,
 869                   s64 *def_val)
 870 {
 871         return -EINVAL;
 872 }
 873 #endif
 874
 875 #define uverbs_get_const(_to, _attrs_bundle, _idx)                             \
 876         ({                                                                     \
 877                 s64 _val;                                                      \
 878                 int _ret = _uverbs_get_const(&_val, _attrs_bundle, _idx,       \
 879                                              type_min(typeof(*_to)),           \
 880                                              type_max(typeof(*_to)), NULL);    \
 881                 (*_to) = _val;                                                 \
 882                 _ret;                                                          \
 883         })
 884
 885 #define uverbs_get_const_default(_to, _attrs_bundle, _idx, _default)           \
 886         ({                                                                     \
 887                 s64 _val;                                                      \
 888                 s64 _def_val = _default;                                       \
 889                 int _ret =                                                     \
 890                         _uverbs_get_const(&_val, _attrs_bundle, _idx,          \
 891                                           type_min(typeof(*_to)),              \
 892                                           type_max(typeof(*_to)), &_def_val);  \
 893                 (*_to) = _val;                                                 \
 894                 _ret;                                                          \
 895         })
 896 #endif