| // SPDX-License-Identifier: GPL-2.0 |
| #include <linux/bpf.h> |
| #include <test_progs.h> |
| #include "cgroup_helpers.h" |
| |
| #define TEST_NS "sock_post_bind" |
| |
| static char bpf_log_buf[4096]; |
| |
| static struct sock_post_bind_test { |
| const char *descr; |
| /* BPF prog properties */ |
| const struct bpf_insn insns[64]; |
| enum bpf_attach_type attach_type; |
| enum bpf_attach_type expected_attach_type; |
| /* Socket properties */ |
| int domain; |
| int type; |
| /* Endpoint to bind() to */ |
| const char *ip; |
| unsigned short port; |
| unsigned short port_retry; |
| |
| /* Expected test result */ |
| enum { |
| ATTACH_REJECT, |
| BIND_REJECT, |
| SUCCESS, |
| RETRY_SUCCESS, |
| RETRY_REJECT |
| } result; |
| } tests[] = { |
| { |
| .descr = "attach type mismatch bind4 vs bind6", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .result = ATTACH_REJECT, |
| }, |
| { |
| .descr = "attach type mismatch bind6 vs bind4", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .result = ATTACH_REJECT, |
| }, |
| { |
| .descr = "attach type mismatch default vs bind4", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = 0, |
| .attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .result = ATTACH_REJECT, |
| }, |
| { |
| .descr = "attach type mismatch bind6 vs sock_create", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .attach_type = BPF_CGROUP_INET_SOCK_CREATE, |
| .result = ATTACH_REJECT, |
| }, |
| { |
| .descr = "bind4 reject all", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .domain = AF_INET, |
| .type = SOCK_STREAM, |
| .ip = "0.0.0.0", |
| .result = BIND_REJECT, |
| }, |
| { |
| .descr = "bind6 reject all", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .domain = AF_INET6, |
| .type = SOCK_STREAM, |
| .ip = "::", |
| .result = BIND_REJECT, |
| }, |
| { |
| .descr = "bind6 deny specific IP & port", |
| .insns = { |
| BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
| |
| /* if (ip == expected && port == expected) */ |
| BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
| offsetof(struct bpf_sock, src_ip6[3])), |
| BPF_JMP_IMM(BPF_JNE, BPF_REG_7, |
| __bpf_constant_ntohl(0x00000001), 4), |
| BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
| offsetof(struct bpf_sock, src_port)), |
| BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2), |
| |
| /* return DENY; */ |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_JMP_A(1), |
| |
| /* else return ALLOW; */ |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .domain = AF_INET6, |
| .type = SOCK_STREAM, |
| .ip = "::1", |
| .port = 8193, |
| .result = BIND_REJECT, |
| }, |
| { |
| .descr = "bind4 allow specific IP & port", |
| .insns = { |
| BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
| |
| /* if (ip == expected && port == expected) */ |
| BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
| offsetof(struct bpf_sock, src_ip4)), |
| BPF_JMP_IMM(BPF_JNE, BPF_REG_7, |
| __bpf_constant_ntohl(0x7F000001), 4), |
| BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
| offsetof(struct bpf_sock, src_port)), |
| BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2), |
| |
| /* return ALLOW; */ |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_JMP_A(1), |
| |
| /* else return DENY; */ |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .domain = AF_INET, |
| .type = SOCK_STREAM, |
| .ip = "127.0.0.1", |
| .port = 4098, |
| .result = SUCCESS, |
| }, |
| { |
| .descr = "bind4 deny specific IP & port of TCP, and retry", |
| .insns = { |
| BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
| |
| /* if (ip == expected && port == expected) */ |
| BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
| offsetof(struct bpf_sock, src_ip4)), |
| BPF_JMP_IMM(BPF_JNE, BPF_REG_7, |
| __bpf_constant_ntohl(0x7F000001), 4), |
| BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
| offsetof(struct bpf_sock, src_port)), |
| BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2), |
| |
| /* return DENY; */ |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_JMP_A(1), |
| |
| /* else return ALLOW; */ |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .domain = AF_INET, |
| .type = SOCK_STREAM, |
| .ip = "127.0.0.1", |
| .port = 4098, |
| .port_retry = 5000, |
| .result = RETRY_SUCCESS, |
| }, |
| { |
| .descr = "bind4 deny specific IP & port of UDP, and retry", |
| .insns = { |
| BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
| |
| /* if (ip == expected && port == expected) */ |
| BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
| offsetof(struct bpf_sock, src_ip4)), |
| BPF_JMP_IMM(BPF_JNE, BPF_REG_7, |
| __bpf_constant_ntohl(0x7F000001), 4), |
| BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
| offsetof(struct bpf_sock, src_port)), |
| BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2), |
| |
| /* return DENY; */ |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_JMP_A(1), |
| |
| /* else return ALLOW; */ |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .domain = AF_INET, |
| .type = SOCK_DGRAM, |
| .ip = "127.0.0.1", |
| .port = 4098, |
| .port_retry = 5000, |
| .result = RETRY_SUCCESS, |
| }, |
| { |
| .descr = "bind6 deny specific IP & port, and retry", |
| .insns = { |
| BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), |
| |
| /* if (ip == expected && port == expected) */ |
| BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
| offsetof(struct bpf_sock, src_ip6[3])), |
| BPF_JMP_IMM(BPF_JNE, BPF_REG_7, |
| __bpf_constant_ntohl(0x00000001), 4), |
| BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, |
| offsetof(struct bpf_sock, src_port)), |
| BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2), |
| |
| /* return DENY; */ |
| BPF_MOV64_IMM(BPF_REG_0, 0), |
| BPF_JMP_A(1), |
| |
| /* else return ALLOW; */ |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .domain = AF_INET6, |
| .type = SOCK_STREAM, |
| .ip = "::1", |
| .port = 8193, |
| .port_retry = 9000, |
| .result = RETRY_SUCCESS, |
| }, |
| { |
| .descr = "bind4 allow all", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .domain = AF_INET, |
| .type = SOCK_STREAM, |
| .ip = "0.0.0.0", |
| .result = SUCCESS, |
| }, |
| { |
| .descr = "bind6 allow all", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .domain = AF_INET6, |
| .type = SOCK_STREAM, |
| .ip = "::", |
| .result = SUCCESS, |
| }, |
| }; |
| |
| static int load_prog(const struct bpf_insn *insns, |
| enum bpf_attach_type expected_attach_type) |
| { |
| LIBBPF_OPTS(bpf_prog_load_opts, opts, |
| .expected_attach_type = expected_attach_type, |
| .log_level = 2, |
| .log_buf = bpf_log_buf, |
| .log_size = sizeof(bpf_log_buf), |
| ); |
| int fd, insns_cnt = 0; |
| |
| for (; |
| insns[insns_cnt].code != (BPF_JMP | BPF_EXIT); |
| insns_cnt++) { |
| } |
| insns_cnt++; |
| |
| fd = bpf_prog_load(BPF_PROG_TYPE_CGROUP_SOCK, NULL, "GPL", insns, |
| insns_cnt, &opts); |
| if (fd < 0) |
| fprintf(stderr, "%s\n", bpf_log_buf); |
| |
| return fd; |
| } |
| |
| static int bind_sock(int domain, int type, const char *ip, |
| unsigned short port, unsigned short port_retry) |
| { |
| struct sockaddr_storage addr; |
| struct sockaddr_in6 *addr6; |
| struct sockaddr_in *addr4; |
| int sockfd = -1; |
| socklen_t len; |
| int res = SUCCESS; |
| |
| sockfd = socket(domain, type, 0); |
| if (sockfd < 0) |
| goto err; |
| |
| memset(&addr, 0, sizeof(addr)); |
| |
| if (domain == AF_INET) { |
| len = sizeof(struct sockaddr_in); |
| addr4 = (struct sockaddr_in *)&addr; |
| addr4->sin_family = domain; |
| addr4->sin_port = htons(port); |
| if (inet_pton(domain, ip, (void *)&addr4->sin_addr) != 1) |
| goto err; |
| } else if (domain == AF_INET6) { |
| len = sizeof(struct sockaddr_in6); |
| addr6 = (struct sockaddr_in6 *)&addr; |
| addr6->sin6_family = domain; |
| addr6->sin6_port = htons(port); |
| if (inet_pton(domain, ip, (void *)&addr6->sin6_addr) != 1) |
| goto err; |
| } else { |
| goto err; |
| } |
| |
| if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1) { |
| /* sys_bind() may fail for different reasons, errno has to be |
| * checked to confirm that BPF program rejected it. |
| */ |
| if (errno != EPERM) |
| goto err; |
| if (port_retry) |
| goto retry; |
| res = BIND_REJECT; |
| goto out; |
| } |
| |
| goto out; |
| retry: |
| if (domain == AF_INET) |
| addr4->sin_port = htons(port_retry); |
| else |
| addr6->sin6_port = htons(port_retry); |
| if (bind(sockfd, (const struct sockaddr *)&addr, len) == -1) { |
| if (errno != EPERM) |
| goto err; |
| res = RETRY_REJECT; |
| } else { |
| res = RETRY_SUCCESS; |
| } |
| goto out; |
| err: |
| res = -1; |
| out: |
| close(sockfd); |
| return res; |
| } |
| |
| static int run_test(int cgroup_fd, struct sock_post_bind_test *test) |
| { |
| int err, prog_fd, res, ret = 0; |
| |
| prog_fd = load_prog(test->insns, test->expected_attach_type); |
| if (prog_fd < 0) |
| goto err; |
| |
| err = bpf_prog_attach(prog_fd, cgroup_fd, test->attach_type, 0); |
| if (err < 0) { |
| if (test->result == ATTACH_REJECT) |
| goto out; |
| else |
| goto err; |
| } |
| |
| res = bind_sock(test->domain, test->type, test->ip, test->port, |
| test->port_retry); |
| if (res > 0 && test->result == res) |
| goto out; |
| err: |
| ret = -1; |
| out: |
| /* Detaching w/o checking return code: best effort attempt. */ |
| if (prog_fd != -1) |
| bpf_prog_detach(cgroup_fd, test->attach_type); |
| close(prog_fd); |
| return ret; |
| } |
| |
| void test_sock_post_bind(void) |
| { |
| struct netns_obj *ns; |
| int cgroup_fd; |
| int i; |
| |
| cgroup_fd = test__join_cgroup("/post_bind"); |
| if (!ASSERT_OK_FD(cgroup_fd, "join_cgroup")) |
| return; |
| |
| ns = netns_new(TEST_NS, true); |
| if (!ASSERT_OK_PTR(ns, "netns_new")) |
| goto cleanup; |
| |
| for (i = 0; i < ARRAY_SIZE(tests); i++) { |
| if (!test__start_subtest(tests[i].descr)) |
| continue; |
| |
| ASSERT_OK(run_test(cgroup_fd, &tests[i]), tests[i].descr); |
| } |
| |
| cleanup: |
| netns_free(ns); |
| close(cgroup_fd); |
| } |
