| // SPDX-License-Identifier: GPL-2.0 |
| // Copyright (c) 2018 Facebook |
| |
| #include <stdio.h> |
| #include <unistd.h> |
| |
| #include <arpa/inet.h> |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| |
| #include <linux/filter.h> |
| |
| #include <bpf/bpf.h> |
| |
| #include "cgroup_helpers.h" |
| #include <bpf/bpf_endian.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, |
| __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(), |
| }, |
| 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, |
| __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(), |
| }, |
| 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; |
| } |
