| // 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; |
| unsigned short port_retry; |
| /* Expected test result */ |
| enum { |
| LOAD_REJECT, |
| ATTACH_REJECT, |
| BIND_REJECT, |
| SUCCESS, |
| RETRY_SUCCESS, |
| RETRY_REJECT |
| } result; |
| }; |
| |
| static struct sock_test tests[] = { |
| { |
| .descr = "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(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .result = LOAD_REJECT, |
| }, |
| { |
| .descr = "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(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .attach_type = BPF_CGROUP_INET4_POST_BIND, |
| .result = LOAD_REJECT, |
| }, |
| { |
| .descr = "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(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .attach_type = BPF_CGROUP_INET6_POST_BIND, |
| .result = LOAD_REJECT, |
| }, |
| { |
| .descr = "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(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE, |
| .attach_type = BPF_CGROUP_INET_SOCK_CREATE, |
| .result = LOAD_REJECT, |
| }, |
| { |
| .descr = "sock_create load w/o expected_attach_type (compat mode)", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = 0, |
| .attach_type = BPF_CGROUP_INET_SOCK_CREATE, |
| .domain = AF_INET, |
| .type = SOCK_STREAM, |
| .ip = "127.0.0.1", |
| .port = 8097, |
| .result = SUCCESS, |
| }, |
| { |
| .descr = "sock_create load w/ expected_attach_type", |
| .insns = { |
| BPF_MOV64_IMM(BPF_REG_0, 1), |
| BPF_EXIT_INSN(), |
| }, |
| .expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE, |
| .attach_type = BPF_CGROUP_INET_SOCK_CREATE, |
| .domain = AF_INET, |
| .type = SOCK_STREAM, |
| .ip = "127.0.0.1", |
| .port = 8097, |
| .result = SUCCESS, |
| }, |
| { |
| .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 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) |
| { |
| LIBBPF_OPTS(bpf_prog_load_opts, opts); |
| int ret, insn_cnt; |
| |
| insn_cnt = probe_prog_length(prog); |
| |
| opts.expected_attach_type = attach_type; |
| opts.log_buf = bpf_log_buf; |
| opts.log_size = BPF_LOG_BUF_SIZE; |
| opts.log_level = 2; |
| |
| ret = bpf_prog_load(BPF_PROG_TYPE_CGROUP_SOCK, NULL, "GPL", prog, insn_cnt, &opts); |
| 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, 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_case(int cgfd, const struct sock_test *test) |
| { |
| int progfd = -1; |
| int err = 0; |
| int res; |
| |
| 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; |
| } |
| |
| res = bind_sock(test->domain, test->type, test->ip, test->port, |
| test->port_retry); |
| if (res > 0 && test->result == res) |
| 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; |
| |
| cgfd = cgroup_setup_and_join(CG_PATH); |
| if (cgfd < 0) |
| goto err; |
| |
| if (run_tests(cgfd)) |
| goto err; |
| |
| goto out; |
| err: |
| err = -1; |
| out: |
| close(cgfd); |
| cleanup_cgroup_environment(); |
| return err; |
| } |
