From 1d436885b23bf4474617914d7eb15e039c83ed99 Mon Sep 17 00:00:00 2001 From: Andrey Ignatov Date: Fri, 30 Mar 2018 15:08:08 -0700 Subject: [PATCH] selftests/bpf: Selftest for sys_bind post-hooks. Add selftest for attach types `BPF_CGROUP_INET4_POST_BIND` and `BPF_CGROUP_INET6_POST_BIND`. The main things tested are: * prog load behaves as expected (valid/invalid accesses in prog); * prog attach behaves as expected (load- vs attach-time attach types); * `BPF_CGROUP_INET_SOCK_CREATE` can be attached in a backward compatible way; * post-hooks return expected result and errno. Example: # ./test_sock Test case: bind4 load with invalid access: src_ip6 .. [PASS] Test case: bind4 load with invalid access: mark .. [PASS] Test case: bind6 load with invalid access: src_ip4 .. [PASS] Test case: sock_create load with invalid access: src_port .. [PASS] Test case: sock_create load w/o expected_attach_type (compat mode) .. [PASS] Test case: sock_create load w/ expected_attach_type .. [PASS] Test case: attach type mismatch bind4 vs bind6 .. [PASS] Test case: attach type mismatch bind6 vs bind4 .. [PASS] Test case: attach type mismatch default vs bind4 .. [PASS] Test case: attach type mismatch bind6 vs sock_create .. [PASS] Test case: bind4 reject all .. [PASS] Test case: bind6 reject all .. [PASS] Test case: bind6 deny specific IP & port .. [PASS] Test case: bind4 allow specific IP & port .. [PASS] Test case: bind4 allow all .. [PASS] Test case: bind6 allow all .. [PASS] Summary: 16 PASSED, 0 FAILED Signed-off-by: Andrey Ignatov Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann --- tools/include/uapi/linux/bpf.h | 11 + tools/testing/selftests/bpf/Makefile | 4 +- tools/testing/selftests/bpf/test_sock.c | 479 ++++++++++++++++++++++++ 3 files changed, 493 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/test_sock.c diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 71051d01e8dd..9d07465023a2 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -152,6 +152,8 @@ enum bpf_attach_type { BPF_CGROUP_INET6_BIND, BPF_CGROUP_INET4_CONNECT, BPF_CGROUP_INET6_CONNECT, + BPF_CGROUP_INET4_POST_BIND, + BPF_CGROUP_INET6_POST_BIND, __MAX_BPF_ATTACH_TYPE }; @@ -947,6 +949,15 @@ struct bpf_sock { __u32 protocol; __u32 mark; __u32 priority; + __u32 src_ip4; /* Allows 1,2,4-byte read. + * Stored in network byte order. + */ + __u32 src_ip6[4]; /* Allows 1,2,4-byte read. + * Stored in network byte order. + */ + __u32 src_port; /* Allows 4-byte read. + * Stored in host byte order + */ }; #define XDP_PACKET_HEADROOM 256 diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index c64d4ebc77ff..0a315ddabbf4 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -23,7 +23,8 @@ urandom_read: urandom_read.c # Order correspond to 'make run_tests' order TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs \ - test_align test_verifier_log test_dev_cgroup test_tcpbpf_user test_sock_addr + test_align test_verifier_log test_dev_cgroup test_tcpbpf_user \ + test_sock test_sock_addr TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test_obj_id.o \ test_pkt_md_access.o test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o \ @@ -52,6 +53,7 @@ $(TEST_GEN_PROGS): $(BPFOBJ) $(TEST_GEN_PROGS_EXTENDED): $(OUTPUT)/libbpf.a $(OUTPUT)/test_dev_cgroup: cgroup_helpers.c +$(OUTPUT)/test_sock: cgroup_helpers.c $(OUTPUT)/test_sock_addr: cgroup_helpers.c .PHONY: force diff --git a/tools/testing/selftests/bpf/test_sock.c b/tools/testing/selftests/bpf/test_sock.c new file mode 100644 index 000000000000..73bb20cfb9b7 --- /dev/null +++ b/tools/testing/selftests/bpf/test_sock.c @@ -0,0 +1,479 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Facebook + +#include +#include + +#include +#include +#include + +#include + +#include + +#include "cgroup_helpers.h" + +#ifndef ARRAY_SIZE +# define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) +#endif + +#define CG_PATH "/foo" +#define MAX_INSNS 512 + +char bpf_log_buf[BPF_LOG_BUF_SIZE]; + +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; + + 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"; + + return bpf_load_program_xattr(&attr, bpf_log_buf, BPF_LOG_BUF_SIZE); +} + +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) + 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; +}