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Jun 2019 09:59:53 -0700 In-Reply-To: <20190619165957.235580-1-sdf@google.com> Message-Id: <20190619165957.235580-6-sdf@google.com> Mime-Version: 1.0 References: <20190619165957.235580-1-sdf@google.com> X-Mailer: git-send-email 2.22.0.410.gd8fdbe21b5-goog Subject: [PATCH bpf-next v7 5/9] selftests/bpf: add sockopt test From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, Stanislav Fomichev , Martin Lau Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Add sockopt selftests: * require proper expected_attach_type * enforce context field read/write access * test bpf_sockopt_handled handler * test EPERM * test limiting optlen from getsockopt * test out-of-bounds access v7: * remove return 2; test retval=0 and optlen=-1 v3: * use DW for optval{,_end} loads v2: * use return code 2 for kernel bypass Cc: Martin Lau Signed-off-by: Stanislav Fomichev --- tools/testing/selftests/bpf/.gitignore | 1 + tools/testing/selftests/bpf/Makefile | 3 +- tools/testing/selftests/bpf/test_sockopt.c | 892 +++++++++++++++++++++ 3 files changed, 895 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/test_sockopt.c diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore index 7470327edcfe..3fe92601223d 100644 --- a/tools/testing/selftests/bpf/.gitignore +++ b/tools/testing/selftests/bpf/.gitignore @@ -39,3 +39,4 @@ libbpf.so.* test_hashmap test_btf_dump xdping +test_sockopt diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 44fb61f4d502..4ff4401a4024 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -26,7 +26,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test test_sock test_btf test_sockmap test_lirc_mode2_user get_cgroup_id_user \ test_socket_cookie test_cgroup_storage test_select_reuseport test_section_names \ test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \ - test_btf_dump test_cgroup_attach xdping + test_btf_dump test_cgroup_attach xdping test_sockopt BPF_OBJ_FILES = $(patsubst %.c,%.o, $(notdir $(wildcard progs/*.c))) TEST_GEN_FILES = $(BPF_OBJ_FILES) @@ -101,6 +101,7 @@ $(OUTPUT)/test_netcnt: cgroup_helpers.c $(OUTPUT)/test_sock_fields: cgroup_helpers.c $(OUTPUT)/test_sysctl: cgroup_helpers.c $(OUTPUT)/test_cgroup_attach: cgroup_helpers.c +$(OUTPUT)/test_sockopt: cgroup_helpers.c .PHONY: force diff --git a/tools/testing/selftests/bpf/test_sockopt.c b/tools/testing/selftests/bpf/test_sockopt.c new file mode 100644 index 000000000000..0c4196eecc45 --- /dev/null +++ b/tools/testing/selftests/bpf/test_sockopt.c @@ -0,0 +1,892 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#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 level; + int optname; + + const char set_optval[64]; + socklen_t set_optlen; + + 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, + + .level = SOL_IP, + .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, + + .level = SOL_IP, + .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, + + .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, + + .optname = 123, + + .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, + + .level = SOL_IP, + .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, + + .level = SOL_IP, + .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, + + .level = SOL_IP, + .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, + + .level = 123, + + .set_optlen = 1, + }, + { + .descr = "setsockopt: 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_SETSOCKOPT, + .expected_attach_type = BPF_CGROUP_SETSOCKOPT, + + .error = DENY_LOAD, + }, + { + .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, + + .optname = 123, + + .set_optlen = 1, + }, + { + .descr = "setsockopt: 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_SETSOCKOPT, + .expected_attach_type = BPF_CGROUP_SETSOCKOPT, + + .error = DENY_LOAD, + }, + { + .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 != input 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)), + 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: deny 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, + + .get_optlen = 64, + + .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, + + .level = SOL_IP, + .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, + + .level = SOL_IP, + .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->level, test->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->level, test->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; +} -- 2.22.0.410.gd8fdbe21b5-goog