diff options
Diffstat (limited to '')
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/sockopt.c | 985 |
1 files changed, 985 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/sockopt.c b/tools/testing/selftests/bpf/prog_tests/sockopt.c new file mode 100644 index 000000000..3e8517a83 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/sockopt.c @@ -0,0 +1,985 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include "cgroup_helpers.h" + +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; +} + +void test_sockopt(void) +{ + int cgroup_fd, i; + + cgroup_fd = test__join_cgroup("/sockopt"); + if (CHECK_FAIL(cgroup_fd < 0)) + return; + + for (i = 0; i < ARRAY_SIZE(tests); i++) { + test__start_subtest(tests[i].descr); + CHECK_FAIL(run_test(cgroup_fd, &tests[i])); + } + + close(cgroup_fd); +} |