| // 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); | |
| } |