// SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2018 Facebook #include #include #include #include #include #include #include #include "cgroup_helpers.h" #include "bpf_rlimit.h" #include "bpf_util.h" #define CG_PATH "/foo" #define MAX_INSNS 512 char bpf_log_buf[BPF_LOG_BUF_SIZE]; static bool verbose = false; struct sock_test { const char *descr; /* BPF prog properties */ struct bpf_insn insns[MAX_INSNS]; enum bpf_attach_type expected_attach_type; enum bpf_attach_type attach_type; /* Socket properties */ int domain; int type; /* Endpoint to bind() to */ const char *ip; unsigned short port; /* Expected test result */ enum { LOAD_REJECT, ATTACH_REJECT, BIND_REJECT, SUCCESS, } result; }; static struct sock_test tests[] = { { "bind4 load with invalid access: src_ip6", .insns = { BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, offsetof(struct bpf_sock, src_ip6[0])), BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, BPF_CGROUP_INET4_POST_BIND, BPF_CGROUP_INET4_POST_BIND, 0, 0, NULL, 0, LOAD_REJECT, }, { "bind4 load with invalid access: mark", .insns = { BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, offsetof(struct bpf_sock, mark)), BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, BPF_CGROUP_INET4_POST_BIND, BPF_CGROUP_INET4_POST_BIND, 0, 0, NULL, 0, LOAD_REJECT, }, { "bind6 load with invalid access: src_ip4", .insns = { BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, offsetof(struct bpf_sock, src_ip4)), BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, BPF_CGROUP_INET6_POST_BIND, BPF_CGROUP_INET6_POST_BIND, 0, 0, NULL, 0, LOAD_REJECT, }, { "sock_create load with invalid access: src_port", .insns = { BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, offsetof(struct bpf_sock, src_port)), BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, BPF_CGROUP_INET_SOCK_CREATE, BPF_CGROUP_INET_SOCK_CREATE, 0, 0, NULL, 0, LOAD_REJECT, }, { "sock_create load w/o expected_attach_type (compat mode)", .insns = { BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, 0, BPF_CGROUP_INET_SOCK_CREATE, AF_INET, SOCK_STREAM, "127.0.0.1", 8097, SUCCESS, }, { "sock_create load w/ expected_attach_type", .insns = { BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, BPF_CGROUP_INET_SOCK_CREATE, BPF_CGROUP_INET_SOCK_CREATE, AF_INET, SOCK_STREAM, "127.0.0.1", 8097, SUCCESS, }, { "attach type mismatch bind4 vs bind6", .insns = { BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, BPF_CGROUP_INET4_POST_BIND, BPF_CGROUP_INET6_POST_BIND, 0, 0, NULL, 0, ATTACH_REJECT, }, { "attach type mismatch bind6 vs bind4", .insns = { BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, BPF_CGROUP_INET6_POST_BIND, BPF_CGROUP_INET4_POST_BIND, 0, 0, NULL, 0, ATTACH_REJECT, }, { "attach type mismatch default vs bind4", .insns = { BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, 0, BPF_CGROUP_INET4_POST_BIND, 0, 0, NULL, 0, ATTACH_REJECT, }, { "attach type mismatch bind6 vs sock_create", .insns = { BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, BPF_CGROUP_INET6_POST_BIND, BPF_CGROUP_INET_SOCK_CREATE, 0, 0, NULL, 0, ATTACH_REJECT, }, { "bind4 reject all", .insns = { BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, BPF_CGROUP_INET4_POST_BIND, BPF_CGROUP_INET4_POST_BIND, AF_INET, SOCK_STREAM, "0.0.0.0", 0, BIND_REJECT, }, { "bind6 reject all", .insns = { BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }, BPF_CGROUP_INET6_POST_BIND, BPF_CGROUP_INET6_POST_BIND, AF_INET6, SOCK_STREAM, "::", 0, BIND_REJECT, }, { "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, 0x01000000, 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(), }, BPF_CGROUP_INET6_POST_BIND, BPF_CGROUP_INET6_POST_BIND, AF_INET6, SOCK_STREAM, "::1", 8193, BIND_REJECT, }, { "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, 0x0100007F, 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(), }, BPF_CGROUP_INET4_POST_BIND, BPF_CGROUP_INET4_POST_BIND, AF_INET, SOCK_STREAM, "127.0.0.1", 4098, SUCCESS, }, { "bind4 allow all", .insns = { BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, BPF_CGROUP_INET4_POST_BIND, BPF_CGROUP_INET4_POST_BIND, AF_INET, SOCK_STREAM, "0.0.0.0", 0, SUCCESS, }, { "bind6 allow all", .insns = { BPF_MOV64_IMM(BPF_REG_0, 1), BPF_EXIT_INSN(), }, BPF_CGROUP_INET6_POST_BIND, BPF_CGROUP_INET6_POST_BIND, AF_INET6, SOCK_STREAM, "::", 0, SUCCESS, }, }; static size_t probe_prog_length(const struct bpf_insn *fp) { size_t len; for (len = MAX_INSNS - 1; len > 0; --len) if (fp[len].code != 0 || fp[len].imm != 0) break; return len + 1; } static int load_sock_prog(const struct bpf_insn *prog, enum bpf_attach_type attach_type) { struct bpf_load_program_attr attr; int ret; memset(&attr, 0, sizeof(struct bpf_load_program_attr)); attr.prog_type = BPF_PROG_TYPE_CGROUP_SOCK; attr.expected_attach_type = attach_type; attr.insns = prog; attr.insns_cnt = probe_prog_length(attr.insns); attr.license = "GPL"; attr.log_level = 2; ret = bpf_load_program_xattr(&attr, bpf_log_buf, BPF_LOG_BUF_SIZE); if (verbose && ret < 0) fprintf(stderr, "%s\n", bpf_log_buf); return ret; } static int attach_sock_prog(int cgfd, int progfd, enum bpf_attach_type attach_type) { return bpf_prog_attach(progfd, cgfd, attach_type, BPF_F_ALLOW_OVERRIDE); } static int bind_sock(int domain, int type, const char *ip, unsigned short port) { struct sockaddr_storage addr; struct sockaddr_in6 *addr6; struct sockaddr_in *addr4; int sockfd = -1; socklen_t len; int err = 0; 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) goto err; goto out; err: err = -1; out: close(sockfd); return err; } static int run_test_case(int cgfd, const struct sock_test *test) { int progfd = -1; int err = 0; printf("Test case: %s .. ", test->descr); progfd = load_sock_prog(test->insns, test->expected_attach_type); if (progfd < 0) { if (test->result == LOAD_REJECT) goto out; else goto err; } if (attach_sock_prog(cgfd, progfd, test->attach_type) == -1) { if (test->result == ATTACH_REJECT) goto out; else goto err; } if (bind_sock(test->domain, test->type, test->ip, test->port) == -1) { /* sys_bind() may fail for different reasons, errno has to be * checked to confirm that BPF program rejected it. */ if (test->result == BIND_REJECT && errno == EPERM) goto out; else goto err; } if (test->result != SUCCESS) goto err; goto out; err: err = -1; out: /* Detaching w/o checking return code: best effort attempt. */ if (progfd != -1) bpf_prog_detach(cgfd, test->attach_type); close(progfd); printf("[%s]\n", err ? "FAIL" : "PASS"); return err; } static int run_tests(int cgfd) { int passes = 0; int fails = 0; int i; for (i = 0; i < ARRAY_SIZE(tests); ++i) { if (run_test_case(cgfd, &tests[i])) ++fails; else ++passes; } printf("Summary: %d PASSED, %d FAILED\n", passes, fails); return fails ? -1 : 0; } int main(int argc, char **argv) { int cgfd = -1; int err = 0; if (setup_cgroup_environment()) goto err; cgfd = create_and_get_cgroup(CG_PATH); if (cgfd < 0) goto err; if (join_cgroup(CG_PATH)) goto err; if (run_tests(cgfd)) goto err; goto out; err: err = -1; out: close(cgfd); cleanup_cgroup_environment(); return err; }