--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#include <linux/filter.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include "bpf_rlimit.h"
+#include "bpf_util.h"
+#include "cgroup_helpers.h"
+
+#define CG_PATH "/sockopt"
+
+static char bpf_log_buf[4096];
+static bool verbose;
+
+enum sockopt_test_error {
+ OK = 0,
+ DENY_LOAD,
+ DENY_ATTACH,
+ EPERM_GETSOCKOPT,
+ EFAULT_GETSOCKOPT,
+ EPERM_SETSOCKOPT,
+ EFAULT_SETSOCKOPT,
+};
+
+static struct sockopt_test {
+ const char *descr;
+ const struct bpf_insn insns[64];
+ enum bpf_attach_type attach_type;
+ enum bpf_attach_type expected_attach_type;
+
+ int set_optname;
+ int set_level;
+ const char set_optval[64];
+ socklen_t set_optlen;
+
+ int get_optname;
+ int get_level;
+ const char get_optval[64];
+ socklen_t get_optlen;
+ socklen_t get_optlen_ret;
+
+ enum sockopt_test_error error;
+} tests[] = {
+
+ /* ==================== getsockopt ==================== */
+
+ {
+ .descr = "getsockopt: no expected_attach_type",
+ .insns = {
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = 0,
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "getsockopt: wrong expected_attach_type",
+ .insns = {
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+ .error = DENY_ATTACH,
+ },
+ {
+ .descr = "getsockopt: bypass bpf hook",
+ .insns = {
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_level = SOL_IP,
+ .set_level = SOL_IP,
+
+ .get_optname = IP_TOS,
+ .set_optname = IP_TOS,
+
+ .set_optval = { 1 << 3 },
+ .set_optlen = 1,
+
+ .get_optval = { 1 << 3 },
+ .get_optlen = 1,
+ },
+ {
+ .descr = "getsockopt: return EPERM from bpf hook",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_level = SOL_IP,
+ .get_optname = IP_TOS,
+
+ .get_optlen = 1,
+ .error = EPERM_GETSOCKOPT,
+ },
+ {
+ .descr = "getsockopt: no optval bounds check, deny loading",
+ .insns = {
+ /* r6 = ctx->optval */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval)),
+
+ /* ctx->optval[0] = 0x80 */
+ BPF_MOV64_IMM(BPF_REG_0, 0x80),
+ BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_0, 0),
+
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "getsockopt: read ctx->level",
+ .insns = {
+ /* r6 = ctx->level */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, level)),
+
+ /* if (ctx->level == 123) { */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 4),
+ /* ctx->retval = 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, retval)),
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_JMP_A(1),
+ /* } else { */
+ /* return 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_level = 123,
+
+ .get_optlen = 1,
+ },
+ {
+ .descr = "getsockopt: deny writing to ctx->level",
+ .insns = {
+ /* ctx->level = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, level)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "getsockopt: read ctx->optname",
+ .insns = {
+ /* r6 = ctx->optname */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optname)),
+
+ /* if (ctx->optname == 123) { */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 4),
+ /* ctx->retval = 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, retval)),
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_JMP_A(1),
+ /* } else { */
+ /* return 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_optname = 123,
+
+ .get_optlen = 1,
+ },
+ {
+ .descr = "getsockopt: read ctx->retval",
+ .insns = {
+ /* r6 = ctx->retval */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, retval)),
+
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_level = SOL_IP,
+ .get_optname = IP_TOS,
+ .get_optlen = 1,
+ },
+ {
+ .descr = "getsockopt: deny writing to ctx->optname",
+ .insns = {
+ /* ctx->optname = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optname)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "getsockopt: read ctx->optlen",
+ .insns = {
+ /* r6 = ctx->optlen */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optlen)),
+
+ /* if (ctx->optlen == 64) { */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 64, 4),
+ /* ctx->retval = 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, retval)),
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_JMP_A(1),
+ /* } else { */
+ /* return 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_optlen = 64,
+ },
+ {
+ .descr = "getsockopt: deny bigger ctx->optlen",
+ .insns = {
+ /* ctx->optlen = 65 */
+ BPF_MOV64_IMM(BPF_REG_0, 65),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optlen)),
+
+ /* ctx->retval = 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, retval)),
+
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_optlen = 64,
+
+ .error = EFAULT_GETSOCKOPT,
+ },
+ {
+ .descr = "getsockopt: deny arbitrary ctx->retval",
+ .insns = {
+ /* ctx->retval = 123 */
+ BPF_MOV64_IMM(BPF_REG_0, 123),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, retval)),
+
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_optlen = 64,
+
+ .error = EFAULT_GETSOCKOPT,
+ },
+ {
+ .descr = "getsockopt: support smaller ctx->optlen",
+ .insns = {
+ /* ctx->optlen = 32 */
+ BPF_MOV64_IMM(BPF_REG_0, 32),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optlen)),
+ /* ctx->retval = 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, retval)),
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_optlen = 64,
+ .get_optlen_ret = 32,
+ },
+ {
+ .descr = "getsockopt: deny writing to ctx->optval",
+ .insns = {
+ /* ctx->optval = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optval)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "getsockopt: deny writing to ctx->optval_end",
+ .insns = {
+ /* ctx->optval_end = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optval_end)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "getsockopt: rewrite value",
+ .insns = {
+ /* r6 = ctx->optval */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval)),
+ /* r2 = ctx->optval */
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_6),
+ /* r6 = ctx->optval + 1 */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 1),
+
+ /* r7 = ctx->optval_end */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval_end)),
+
+ /* if (ctx->optval + 1 <= ctx->optval_end) { */
+ BPF_JMP_REG(BPF_JGT, BPF_REG_6, BPF_REG_7, 1),
+ /* ctx->optval[0] = 0xF0 */
+ BPF_ST_MEM(BPF_B, BPF_REG_2, 0, 0xF0),
+ /* } */
+
+ /* ctx->retval = 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, retval)),
+
+ /* return 1*/
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_level = SOL_IP,
+ .get_optname = IP_TOS,
+
+ .get_optval = { 0xF0 },
+ .get_optlen = 1,
+ },
+
+ /* ==================== setsockopt ==================== */
+
+ {
+ .descr = "setsockopt: no expected_attach_type",
+ .insns = {
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = 0,
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: wrong expected_attach_type",
+ .insns = {
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+ .error = DENY_ATTACH,
+ },
+ {
+ .descr = "setsockopt: bypass bpf hook",
+ .insns = {
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .get_level = SOL_IP,
+ .set_level = SOL_IP,
+
+ .get_optname = IP_TOS,
+ .set_optname = IP_TOS,
+
+ .set_optval = { 1 << 3 },
+ .set_optlen = 1,
+
+ .get_optval = { 1 << 3 },
+ .get_optlen = 1,
+ },
+ {
+ .descr = "setsockopt: return EPERM from bpf hook",
+ .insns = {
+ /* return 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .set_level = SOL_IP,
+ .set_optname = IP_TOS,
+
+ .set_optlen = 1,
+ .error = EPERM_SETSOCKOPT,
+ },
+ {
+ .descr = "setsockopt: no optval bounds check, deny loading",
+ .insns = {
+ /* r6 = ctx->optval */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval)),
+
+ /* r0 = ctx->optval[0] */
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6, 0),
+
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: read ctx->level",
+ .insns = {
+ /* r6 = ctx->level */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, level)),
+
+ /* if (ctx->level == 123) { */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 4),
+ /* ctx->optlen = -1 */
+ BPF_MOV64_IMM(BPF_REG_0, -1),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optlen)),
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_JMP_A(1),
+ /* } else { */
+ /* return 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .set_level = 123,
+
+ .set_optlen = 1,
+ },
+ {
+ .descr = "setsockopt: allow changing ctx->level",
+ .insns = {
+ /* ctx->level = SOL_IP */
+ BPF_MOV64_IMM(BPF_REG_0, SOL_IP),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, level)),
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .get_level = SOL_IP,
+ .set_level = 234, /* should be rewritten to SOL_IP */
+
+ .get_optname = IP_TOS,
+ .set_optname = IP_TOS,
+
+ .set_optval = { 1 << 3 },
+ .set_optlen = 1,
+ .get_optval = { 1 << 3 },
+ .get_optlen = 1,
+ },
+ {
+ .descr = "setsockopt: read ctx->optname",
+ .insns = {
+ /* r6 = ctx->optname */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optname)),
+
+ /* if (ctx->optname == 123) { */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 4),
+ /* ctx->optlen = -1 */
+ BPF_MOV64_IMM(BPF_REG_0, -1),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optlen)),
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_JMP_A(1),
+ /* } else { */
+ /* return 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .set_optname = 123,
+
+ .set_optlen = 1,
+ },
+ {
+ .descr = "setsockopt: allow changing ctx->optname",
+ .insns = {
+ /* ctx->optname = IP_TOS */
+ BPF_MOV64_IMM(BPF_REG_0, IP_TOS),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optname)),
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .get_level = SOL_IP,
+ .set_level = SOL_IP,
+
+ .get_optname = IP_TOS,
+ .set_optname = 456, /* should be rewritten to IP_TOS */
+
+ .set_optval = { 1 << 3 },
+ .set_optlen = 1,
+ .get_optval = { 1 << 3 },
+ .get_optlen = 1,
+ },
+ {
+ .descr = "setsockopt: read ctx->optlen",
+ .insns = {
+ /* r6 = ctx->optlen */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optlen)),
+
+ /* if (ctx->optlen == 64) { */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 64, 4),
+ /* ctx->optlen = -1 */
+ BPF_MOV64_IMM(BPF_REG_0, -1),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optlen)),
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_JMP_A(1),
+ /* } else { */
+ /* return 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .set_optlen = 64,
+ },
+ {
+ .descr = "setsockopt: ctx->optlen == -1 is ok",
+ .insns = {
+ /* ctx->optlen = -1 */
+ BPF_MOV64_IMM(BPF_REG_0, -1),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optlen)),
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .set_optlen = 64,
+ },
+ {
+ .descr = "setsockopt: deny ctx->optlen < 0 (except -1)",
+ .insns = {
+ /* ctx->optlen = -2 */
+ BPF_MOV64_IMM(BPF_REG_0, -2),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optlen)),
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .set_optlen = 4,
+
+ .error = EFAULT_SETSOCKOPT,
+ },
+ {
+ .descr = "setsockopt: deny ctx->optlen > input optlen",
+ .insns = {
+ /* ctx->optlen = 65 */
+ BPF_MOV64_IMM(BPF_REG_0, 65),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optlen)),
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .set_optlen = 64,
+
+ .error = EFAULT_SETSOCKOPT,
+ },
+ {
+ .descr = "setsockopt: allow changing ctx->optlen within bounds",
+ .insns = {
+ /* r6 = ctx->optval */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval)),
+ /* r2 = ctx->optval */
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_6),
+ /* r6 = ctx->optval + 1 */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 1),
+
+ /* r7 = ctx->optval_end */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval_end)),
+
+ /* if (ctx->optval + 1 <= ctx->optval_end) { */
+ BPF_JMP_REG(BPF_JGT, BPF_REG_6, BPF_REG_7, 1),
+ /* ctx->optval[0] = 1 << 3 */
+ BPF_ST_MEM(BPF_B, BPF_REG_2, 0, 1 << 3),
+ /* } */
+
+ /* ctx->optlen = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optlen)),
+
+ /* return 1*/
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .get_level = SOL_IP,
+ .set_level = SOL_IP,
+
+ .get_optname = IP_TOS,
+ .set_optname = IP_TOS,
+
+ .set_optval = { 1, 1, 1, 1 },
+ .set_optlen = 4,
+ .get_optval = { 1 << 3 },
+ .get_optlen = 1,
+ },
+ {
+ .descr = "setsockopt: deny write ctx->retval",
+ .insns = {
+ /* ctx->retval = 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, retval)),
+
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: deny read ctx->retval",
+ .insns = {
+ /* r6 = ctx->retval */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, retval)),
+
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: deny writing to ctx->optval",
+ .insns = {
+ /* ctx->optval = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optval)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: deny writing to ctx->optval_end",
+ .insns = {
+ /* ctx->optval_end = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optval_end)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: allow IP_TOS <= 128",
+ .insns = {
+ /* r6 = ctx->optval */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval)),
+ /* r7 = ctx->optval + 1 */
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_6),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1),
+
+ /* r8 = ctx->optval_end */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval_end)),
+
+ /* if (ctx->optval + 1 <= ctx->optval_end) { */
+ BPF_JMP_REG(BPF_JGT, BPF_REG_7, BPF_REG_8, 4),
+
+ /* r9 = ctx->optval[0] */
+ BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_6, 0),
+
+ /* if (ctx->optval[0] < 128) */
+ BPF_JMP_IMM(BPF_JGT, BPF_REG_9, 128, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_JMP_A(1),
+ /* } */
+
+ /* } else { */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .get_level = SOL_IP,
+ .set_level = SOL_IP,
+
+ .get_optname = IP_TOS,
+ .set_optname = IP_TOS,
+
+ .set_optval = { 0x80 },
+ .set_optlen = 1,
+ .get_optval = { 0x80 },
+ .get_optlen = 1,
+ },
+ {
+ .descr = "setsockopt: deny IP_TOS > 128",
+ .insns = {
+ /* r6 = ctx->optval */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval)),
+ /* r7 = ctx->optval + 1 */
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_6),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1),
+
+ /* r8 = ctx->optval_end */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval_end)),
+
+ /* if (ctx->optval + 1 <= ctx->optval_end) { */
+ BPF_JMP_REG(BPF_JGT, BPF_REG_7, BPF_REG_8, 4),
+
+ /* r9 = ctx->optval[0] */
+ BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_6, 0),
+
+ /* if (ctx->optval[0] < 128) */
+ BPF_JMP_IMM(BPF_JGT, BPF_REG_9, 128, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_JMP_A(1),
+ /* } */
+
+ /* } else { */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .get_level = SOL_IP,
+ .set_level = SOL_IP,
+
+ .get_optname = IP_TOS,
+ .set_optname = IP_TOS,
+
+ .set_optval = { 0x81 },
+ .set_optlen = 1,
+ .get_optval = { 0x00 },
+ .get_optlen = 1,
+
+ .error = EPERM_SETSOCKOPT,
+ },
+};
+
+static int load_prog(const struct bpf_insn *insns,
+ enum bpf_attach_type expected_attach_type)
+{
+ struct bpf_load_program_attr attr = {
+ .prog_type = BPF_PROG_TYPE_CGROUP_SOCKOPT,
+ .expected_attach_type = expected_attach_type,
+ .insns = insns,
+ .license = "GPL",
+ .log_level = 2,
+ };
+ int fd;
+
+ for (;
+ insns[attr.insns_cnt].code != (BPF_JMP | BPF_EXIT);
+ attr.insns_cnt++) {
+ }
+ attr.insns_cnt++;
+
+ fd = bpf_load_program_xattr(&attr, bpf_log_buf, sizeof(bpf_log_buf));
+ if (verbose && fd < 0)
+ fprintf(stderr, "%s\n", bpf_log_buf);
+
+ return fd;
+}
+
+static int run_test(int cgroup_fd, struct sockopt_test *test)
+{
+ int sock_fd, err, prog_fd;
+ void *optval = NULL;
+ int ret = 0;
+
+ prog_fd = load_prog(test->insns, test->expected_attach_type);
+ if (prog_fd < 0) {
+ if (test->error == DENY_LOAD)
+ return 0;
+
+ log_err("Failed to load BPF program");
+ return -1;
+ }
+
+ err = bpf_prog_attach(prog_fd, cgroup_fd, test->attach_type, 0);
+ if (err < 0) {
+ if (test->error == DENY_ATTACH)
+ goto close_prog_fd;
+
+ log_err("Failed to attach BPF program");
+ ret = -1;
+ goto close_prog_fd;
+ }
+
+ sock_fd = socket(AF_INET, SOCK_STREAM, 0);
+ if (sock_fd < 0) {
+ log_err("Failed to create AF_INET socket");
+ ret = -1;
+ goto detach_prog;
+ }
+
+ if (test->set_optlen) {
+ err = setsockopt(sock_fd, test->set_level, test->set_optname,
+ test->set_optval, test->set_optlen);
+ if (err) {
+ if (errno == EPERM && test->error == EPERM_SETSOCKOPT)
+ goto close_sock_fd;
+ if (errno == EFAULT && test->error == EFAULT_SETSOCKOPT)
+ goto free_optval;
+
+ log_err("Failed to call setsockopt");
+ ret = -1;
+ goto close_sock_fd;
+ }
+ }
+
+ if (test->get_optlen) {
+ optval = malloc(test->get_optlen);
+ socklen_t optlen = test->get_optlen;
+ socklen_t expected_get_optlen = test->get_optlen_ret ?:
+ test->get_optlen;
+
+ err = getsockopt(sock_fd, test->get_level, test->get_optname,
+ optval, &optlen);
+ if (err) {
+ if (errno == EPERM && test->error == EPERM_GETSOCKOPT)
+ goto free_optval;
+ if (errno == EFAULT && test->error == EFAULT_GETSOCKOPT)
+ goto free_optval;
+
+ log_err("Failed to call getsockopt");
+ ret = -1;
+ goto free_optval;
+ }
+
+ if (optlen != expected_get_optlen) {
+ errno = 0;
+ log_err("getsockopt returned unexpected optlen");
+ ret = -1;
+ goto free_optval;
+ }
+
+ if (memcmp(optval, test->get_optval, optlen) != 0) {
+ errno = 0;
+ log_err("getsockopt returned unexpected optval");
+ ret = -1;
+ goto free_optval;
+ }
+ }
+
+ ret = test->error != OK;
+
+free_optval:
+ free(optval);
+close_sock_fd:
+ close(sock_fd);
+detach_prog:
+ bpf_prog_detach2(prog_fd, cgroup_fd, test->attach_type);
+close_prog_fd:
+ close(prog_fd);
+ return ret;
+}
+
+int main(int args, char **argv)
+{
+ int err = EXIT_FAILURE, error_cnt = 0;
+ int cgroup_fd, i;
+
+ if (setup_cgroup_environment())
+ goto cleanup_obj;
+
+ cgroup_fd = create_and_get_cgroup(CG_PATH);
+ if (cgroup_fd < 0)
+ goto cleanup_cgroup_env;
+
+ if (join_cgroup(CG_PATH))
+ goto cleanup_cgroup;
+
+ for (i = 0; i < ARRAY_SIZE(tests); i++) {
+ int err = run_test(cgroup_fd, &tests[i]);
+
+ if (err)
+ error_cnt++;
+
+ printf("#%d %s: %s\n", i, err ? "FAIL" : "PASS",
+ tests[i].descr);
+ }
+
+ printf("Summary: %ld PASSED, %d FAILED\n",
+ ARRAY_SIZE(tests) - error_cnt, error_cnt);
+ err = error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;
+
+cleanup_cgroup:
+ close(cgroup_fd);
+cleanup_cgroup_env:
+ cleanup_cgroup_environment();
+cleanup_obj:
+ return err;
+}
projects / linux.git / commitdiff