From 04b6ab731209eac1e130fa00281a29278eca2f57 Mon Sep 17 00:00:00 2001 From: Andrey Ignatov Date: Fri, 25 May 2018 08:55:27 -0700 Subject: [PATCH] selftests/bpf: Selftest for sys_sendmsg hooks Add selftest for BPF_CGROUP_UDP4_SENDMSG and BPF_CGROUP_UDP6_SENDMSG attach types. Try to sendmsg(2) to specific IP:port and test that: * source IP is overridden as expected. * remote IP:port pair is overridden as expected; Both UDPv4 and UDPv6 are tested. Output: # test_sock_addr.sh 2>/dev/null Wait for testing IPv4/IPv6 to become available ... OK ... pre-existing test-cases skipped ... Test case: sendmsg4: load prog with wrong expected attach type .. [PASS] Test case: sendmsg4: attach prog with wrong attach type .. [PASS] Test case: sendmsg4: rewrite IP & port (asm) .. [PASS] Test case: sendmsg4: rewrite IP & port (C) .. [PASS] Test case: sendmsg4: deny call .. [PASS] Test case: sendmsg6: load prog with wrong expected attach type .. [PASS] Test case: sendmsg6: attach prog with wrong attach type .. [PASS] Test case: sendmsg6: rewrite IP & port (asm) .. [PASS] Test case: sendmsg6: rewrite IP & port (C) .. [PASS] Test case: sendmsg6: IPv4-mapped IPv6 .. [PASS] Test case: sendmsg6: deny call .. [PASS] Summary: 27 PASSED, 0 FAILED Signed-off-by: Andrey Ignatov Acked-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/Makefile | 2 +- tools/testing/selftests/bpf/sendmsg4_prog.c | 49 +++ tools/testing/selftests/bpf/sendmsg6_prog.c | 60 ++++ tools/testing/selftests/bpf/test_sock_addr.c | 518 +++++++++++++++++++++++++++ 4 files changed, 628 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/sendmsg4_prog.c create mode 100644 tools/testing/selftests/bpf/sendmsg6_prog.c diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 8504444..a1b66da 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -34,7 +34,7 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o test_adjust_tail.o \ test_btf_haskv.o test_btf_nokv.o test_sockmap_kern.o test_tunnel_kern.o \ test_get_stack_rawtp.o test_sockmap_kern.o test_sockhash_kern.o \ - test_lwt_seg6local.o + test_lwt_seg6local.o sendmsg4_prog.o sendmsg6_prog.o # Order correspond to 'make run_tests' order TEST_PROGS := test_kmod.sh \ diff --git a/tools/testing/selftests/bpf/sendmsg4_prog.c b/tools/testing/selftests/bpf/sendmsg4_prog.c new file mode 100644 index 0000000..a91536b --- /dev/null +++ b/tools/testing/selftests/bpf/sendmsg4_prog.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Facebook + +#include +#include +#include + +#include "bpf_helpers.h" +#include "bpf_endian.h" + +#define SRC1_IP4 0xAC100001U /* 172.16.0.1 */ +#define SRC2_IP4 0x00000000U +#define SRC_REWRITE_IP4 0x7f000004U +#define DST_IP4 0xC0A801FEU /* 192.168.1.254 */ +#define DST_REWRITE_IP4 0x7f000001U +#define DST_PORT 4040 +#define DST_REWRITE_PORT4 4444 + +int _version SEC("version") = 1; + +SEC("cgroup/sendmsg4") +int sendmsg_v4_prog(struct bpf_sock_addr *ctx) +{ + if (ctx->type != SOCK_DGRAM) + return 0; + + /* Rewrite source. */ + if (ctx->msg_src_ip4 == bpf_htonl(SRC1_IP4) || + ctx->msg_src_ip4 == bpf_htonl(SRC2_IP4)) { + ctx->msg_src_ip4 = bpf_htonl(SRC_REWRITE_IP4); + } else { + /* Unexpected source. Reject sendmsg. */ + return 0; + } + + /* Rewrite destination. */ + if ((ctx->user_ip4 >> 24) == (bpf_htonl(DST_IP4) >> 24) && + ctx->user_port == bpf_htons(DST_PORT)) { + ctx->user_ip4 = bpf_htonl(DST_REWRITE_IP4); + ctx->user_port = bpf_htons(DST_REWRITE_PORT4); + } else { + /* Unexpected source. Reject sendmsg. */ + return 0; + } + + return 1; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/sendmsg6_prog.c b/tools/testing/selftests/bpf/sendmsg6_prog.c new file mode 100644 index 0000000..5aeaa28 --- /dev/null +++ b/tools/testing/selftests/bpf/sendmsg6_prog.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Facebook + +#include +#include +#include + +#include "bpf_helpers.h" +#include "bpf_endian.h" + +#define SRC_REWRITE_IP6_0 0 +#define SRC_REWRITE_IP6_1 0 +#define SRC_REWRITE_IP6_2 0 +#define SRC_REWRITE_IP6_3 6 + +#define DST_REWRITE_IP6_0 0 +#define DST_REWRITE_IP6_1 0 +#define DST_REWRITE_IP6_2 0 +#define DST_REWRITE_IP6_3 1 + +#define DST_REWRITE_PORT6 6666 + +int _version SEC("version") = 1; + +SEC("cgroup/sendmsg6") +int sendmsg_v6_prog(struct bpf_sock_addr *ctx) +{ + if (ctx->type != SOCK_DGRAM) + return 0; + + /* Rewrite source. */ + if (ctx->msg_src_ip6[3] == bpf_htonl(1) || + ctx->msg_src_ip6[3] == bpf_htonl(0)) { + ctx->msg_src_ip6[0] = bpf_htonl(SRC_REWRITE_IP6_0); + ctx->msg_src_ip6[1] = bpf_htonl(SRC_REWRITE_IP6_1); + ctx->msg_src_ip6[2] = bpf_htonl(SRC_REWRITE_IP6_2); + ctx->msg_src_ip6[3] = bpf_htonl(SRC_REWRITE_IP6_3); + } else { + /* Unexpected source. Reject sendmsg. */ + return 0; + } + + /* Rewrite destination. */ + if ((ctx->user_ip6[0] & 0xFFFF) == bpf_htons(0xFACE) && + ctx->user_ip6[0] >> 16 == bpf_htons(0xB00C)) { + ctx->user_ip6[0] = bpf_htonl(DST_REWRITE_IP6_0); + ctx->user_ip6[1] = bpf_htonl(DST_REWRITE_IP6_1); + ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_2); + ctx->user_ip6[3] = bpf_htonl(DST_REWRITE_IP6_3); + + ctx->user_port = bpf_htons(DST_REWRITE_PORT6); + } else { + /* Unexpected destination. Reject sendmsg. */ + return 0; + } + + return 1; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/test_sock_addr.c b/tools/testing/selftests/bpf/test_sock_addr.c index ed3e397..a5e76b9 100644 --- a/tools/testing/selftests/bpf/test_sock_addr.c +++ b/tools/testing/selftests/bpf/test_sock_addr.c @@ -1,12 +1,16 @@ // SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2018 Facebook +#define _GNU_SOURCE + #include #include #include #include +#include #include +#include #include #include @@ -17,6 +21,10 @@ #include "cgroup_helpers.h" #include "bpf_rlimit.h" +#ifndef ENOTSUPP +# define ENOTSUPP 524 +#endif + #ifndef ARRAY_SIZE # define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) #endif @@ -24,15 +32,20 @@ #define CG_PATH "/foo" #define CONNECT4_PROG_PATH "./connect4_prog.o" #define CONNECT6_PROG_PATH "./connect6_prog.o" +#define SENDMSG4_PROG_PATH "./sendmsg4_prog.o" +#define SENDMSG6_PROG_PATH "./sendmsg6_prog.o" #define SERV4_IP "192.168.1.254" #define SERV4_REWRITE_IP "127.0.0.1" +#define SRC4_IP "172.16.0.1" #define SRC4_REWRITE_IP "127.0.0.4" #define SERV4_PORT 4040 #define SERV4_REWRITE_PORT 4444 #define SERV6_IP "face:b00c:1234:5678::abcd" #define SERV6_REWRITE_IP "::1" +#define SERV6_V4MAPPED_IP "::ffff:192.168.0.4" +#define SRC6_IP "::1" #define SRC6_REWRITE_IP "::6" #define SERV6_PORT 6060 #define SERV6_REWRITE_PORT 6666 @@ -65,6 +78,8 @@ struct sock_addr_test { enum { LOAD_REJECT, ATTACH_REJECT, + SYSCALL_EPERM, + SYSCALL_ENOTSUPP, SUCCESS, } expected_result; }; @@ -73,6 +88,12 @@ static int bind4_prog_load(const struct sock_addr_test *test); static int bind6_prog_load(const struct sock_addr_test *test); static int connect4_prog_load(const struct sock_addr_test *test); static int connect6_prog_load(const struct sock_addr_test *test); +static int sendmsg_deny_prog_load(const struct sock_addr_test *test); +static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test); +static int sendmsg4_rw_c_prog_load(const struct sock_addr_test *test); +static int sendmsg6_rw_asm_prog_load(const struct sock_addr_test *test); +static int sendmsg6_rw_c_prog_load(const struct sock_addr_test *test); +static int sendmsg6_rw_v4mapped_prog_load(const struct sock_addr_test *test); static struct sock_addr_test tests[] = { /* bind */ @@ -302,6 +323,162 @@ static struct sock_addr_test tests[] = { SRC6_REWRITE_IP, SUCCESS, }, + + /* sendmsg */ + { + "sendmsg4: load prog with wrong expected attach type", + sendmsg4_rw_asm_prog_load, + BPF_CGROUP_UDP6_SENDMSG, + BPF_CGROUP_UDP4_SENDMSG, + AF_INET, + SOCK_DGRAM, + NULL, + 0, + NULL, + 0, + NULL, + LOAD_REJECT, + }, + { + "sendmsg4: attach prog with wrong attach type", + sendmsg4_rw_asm_prog_load, + BPF_CGROUP_UDP4_SENDMSG, + BPF_CGROUP_UDP6_SENDMSG, + AF_INET, + SOCK_DGRAM, + NULL, + 0, + NULL, + 0, + NULL, + ATTACH_REJECT, + }, + { + "sendmsg4: rewrite IP & port (asm)", + sendmsg4_rw_asm_prog_load, + BPF_CGROUP_UDP4_SENDMSG, + BPF_CGROUP_UDP4_SENDMSG, + AF_INET, + SOCK_DGRAM, + SERV4_IP, + SERV4_PORT, + SERV4_REWRITE_IP, + SERV4_REWRITE_PORT, + SRC4_REWRITE_IP, + SUCCESS, + }, + { + "sendmsg4: rewrite IP & port (C)", + sendmsg4_rw_c_prog_load, + BPF_CGROUP_UDP4_SENDMSG, + BPF_CGROUP_UDP4_SENDMSG, + AF_INET, + SOCK_DGRAM, + SERV4_IP, + SERV4_PORT, + SERV4_REWRITE_IP, + SERV4_REWRITE_PORT, + SRC4_REWRITE_IP, + SUCCESS, + }, + { + "sendmsg4: deny call", + sendmsg_deny_prog_load, + BPF_CGROUP_UDP4_SENDMSG, + BPF_CGROUP_UDP4_SENDMSG, + AF_INET, + SOCK_DGRAM, + SERV4_IP, + SERV4_PORT, + SERV4_REWRITE_IP, + SERV4_REWRITE_PORT, + SRC4_REWRITE_IP, + SYSCALL_EPERM, + }, + { + "sendmsg6: load prog with wrong expected attach type", + sendmsg6_rw_asm_prog_load, + BPF_CGROUP_UDP4_SENDMSG, + BPF_CGROUP_UDP6_SENDMSG, + AF_INET6, + SOCK_DGRAM, + NULL, + 0, + NULL, + 0, + NULL, + LOAD_REJECT, + }, + { + "sendmsg6: attach prog with wrong attach type", + sendmsg6_rw_asm_prog_load, + BPF_CGROUP_UDP6_SENDMSG, + BPF_CGROUP_UDP4_SENDMSG, + AF_INET6, + SOCK_DGRAM, + NULL, + 0, + NULL, + 0, + NULL, + ATTACH_REJECT, + }, + { + "sendmsg6: rewrite IP & port (asm)", + sendmsg6_rw_asm_prog_load, + BPF_CGROUP_UDP6_SENDMSG, + BPF_CGROUP_UDP6_SENDMSG, + AF_INET6, + SOCK_DGRAM, + SERV6_IP, + SERV6_PORT, + SERV6_REWRITE_IP, + SERV6_REWRITE_PORT, + SRC6_REWRITE_IP, + SUCCESS, + }, + { + "sendmsg6: rewrite IP & port (C)", + sendmsg6_rw_c_prog_load, + BPF_CGROUP_UDP6_SENDMSG, + BPF_CGROUP_UDP6_SENDMSG, + AF_INET6, + SOCK_DGRAM, + SERV6_IP, + SERV6_PORT, + SERV6_REWRITE_IP, + SERV6_REWRITE_PORT, + SRC6_REWRITE_IP, + SUCCESS, + }, + { + "sendmsg6: IPv4-mapped IPv6", + sendmsg6_rw_v4mapped_prog_load, + BPF_CGROUP_UDP6_SENDMSG, + BPF_CGROUP_UDP6_SENDMSG, + AF_INET6, + SOCK_DGRAM, + SERV6_IP, + SERV6_PORT, + SERV6_REWRITE_IP, + SERV6_REWRITE_PORT, + SRC6_REWRITE_IP, + SYSCALL_ENOTSUPP, + }, + { + "sendmsg6: deny call", + sendmsg_deny_prog_load, + BPF_CGROUP_UDP6_SENDMSG, + BPF_CGROUP_UDP6_SENDMSG, + AF_INET6, + SOCK_DGRAM, + SERV6_IP, + SERV6_PORT, + SERV6_REWRITE_IP, + SERV6_REWRITE_PORT, + SRC6_REWRITE_IP, + SYSCALL_EPERM, + }, }; static int mk_sockaddr(int domain, const char *ip, unsigned short port, @@ -540,6 +717,141 @@ static int connect6_prog_load(const struct sock_addr_test *test) return load_path(test, CONNECT6_PROG_PATH); } +static int sendmsg_deny_prog_load(const struct sock_addr_test *test) +{ + struct bpf_insn insns[] = { + /* return 0 */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }; + return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn)); +} + +static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test) +{ + struct sockaddr_in dst4_rw_addr; + struct in_addr src4_rw_ip; + + if (inet_pton(AF_INET, SRC4_REWRITE_IP, (void *)&src4_rw_ip) != 1) { + log_err("Invalid IPv4: %s", SRC4_REWRITE_IP); + return -1; + } + + if (mk_sockaddr(AF_INET, SERV4_REWRITE_IP, SERV4_REWRITE_PORT, + (struct sockaddr *)&dst4_rw_addr, + sizeof(dst4_rw_addr)) == -1) + return -1; + + struct bpf_insn insns[] = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + + /* if (sk.family == AF_INET && */ + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, + offsetof(struct bpf_sock_addr, family)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET, 8), + + /* sk.type == SOCK_DGRAM) { */ + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, + offsetof(struct bpf_sock_addr, type)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, SOCK_DGRAM, 6), + + /* msg_src_ip4 = src4_rw_ip */ + BPF_MOV32_IMM(BPF_REG_7, src4_rw_ip.s_addr), + BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7, + offsetof(struct bpf_sock_addr, msg_src_ip4)), + + /* user_ip4 = dst4_rw_addr.sin_addr */ + BPF_MOV32_IMM(BPF_REG_7, dst4_rw_addr.sin_addr.s_addr), + BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7, + offsetof(struct bpf_sock_addr, user_ip4)), + + /* user_port = dst4_rw_addr.sin_port */ + BPF_MOV32_IMM(BPF_REG_7, dst4_rw_addr.sin_port), + BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7, + offsetof(struct bpf_sock_addr, user_port)), + /* } */ + + /* return 1 */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }; + + return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn)); +} + +static int sendmsg4_rw_c_prog_load(const struct sock_addr_test *test) +{ + return load_path(test, SENDMSG4_PROG_PATH); +} + +static int sendmsg6_rw_dst_asm_prog_load(const struct sock_addr_test *test, + const char *rw_dst_ip) +{ + struct sockaddr_in6 dst6_rw_addr; + struct in6_addr src6_rw_ip; + + if (inet_pton(AF_INET6, SRC6_REWRITE_IP, (void *)&src6_rw_ip) != 1) { + log_err("Invalid IPv6: %s", SRC6_REWRITE_IP); + return -1; + } + + if (mk_sockaddr(AF_INET6, rw_dst_ip, SERV6_REWRITE_PORT, + (struct sockaddr *)&dst6_rw_addr, + sizeof(dst6_rw_addr)) == -1) + return -1; + + struct bpf_insn insns[] = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + + /* if (sk.family == AF_INET6) { */ + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, + offsetof(struct bpf_sock_addr, family)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET6, 18), + +#define STORE_IPV6_WORD_N(DST, SRC, N) \ + BPF_MOV32_IMM(BPF_REG_7, SRC[N]), \ + BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7, \ + offsetof(struct bpf_sock_addr, DST[N])) + +#define STORE_IPV6(DST, SRC) \ + STORE_IPV6_WORD_N(DST, SRC, 0), \ + STORE_IPV6_WORD_N(DST, SRC, 1), \ + STORE_IPV6_WORD_N(DST, SRC, 2), \ + STORE_IPV6_WORD_N(DST, SRC, 3) + + STORE_IPV6(msg_src_ip6, src6_rw_ip.s6_addr32), + STORE_IPV6(user_ip6, dst6_rw_addr.sin6_addr.s6_addr32), + + /* user_port = dst6_rw_addr.sin6_port */ + BPF_MOV32_IMM(BPF_REG_7, dst6_rw_addr.sin6_port), + BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7, + offsetof(struct bpf_sock_addr, user_port)), + + /* } */ + + /* return 1 */ + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }; + + return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn)); +} + +static int sendmsg6_rw_asm_prog_load(const struct sock_addr_test *test) +{ + return sendmsg6_rw_dst_asm_prog_load(test, SERV6_REWRITE_IP); +} + +static int sendmsg6_rw_v4mapped_prog_load(const struct sock_addr_test *test) +{ + return sendmsg6_rw_dst_asm_prog_load(test, SERV6_V4MAPPED_IP); +} + +static int sendmsg6_rw_c_prog_load(const struct sock_addr_test *test) +{ + return load_path(test, SENDMSG6_PROG_PATH); +} + static int cmp_addr(const struct sockaddr_storage *addr1, const struct sockaddr_storage *addr2, int cmp_port) { @@ -656,6 +968,135 @@ out: return fd; } +int init_pktinfo(int domain, struct cmsghdr *cmsg) +{ + struct in6_pktinfo *pktinfo6; + struct in_pktinfo *pktinfo4; + + if (domain == AF_INET) { + cmsg->cmsg_level = SOL_IP; + cmsg->cmsg_type = IP_PKTINFO; + cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo)); + pktinfo4 = (struct in_pktinfo *)CMSG_DATA(cmsg); + memset(pktinfo4, 0, sizeof(struct in_pktinfo)); + if (inet_pton(domain, SRC4_IP, + (void *)&pktinfo4->ipi_spec_dst) != 1) + return -1; + } else if (domain == AF_INET6) { + cmsg->cmsg_level = SOL_IPV6; + cmsg->cmsg_type = IPV6_PKTINFO; + cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo)); + pktinfo6 = (struct in6_pktinfo *)CMSG_DATA(cmsg); + memset(pktinfo6, 0, sizeof(struct in6_pktinfo)); + if (inet_pton(domain, SRC6_IP, + (void *)&pktinfo6->ipi6_addr) != 1) + return -1; + } else { + return -1; + } + + return 0; +} + +static int sendmsg_to_server(const struct sockaddr_storage *addr, + socklen_t addr_len, int set_cmsg, int *syscall_err) +{ + union { + char buf[CMSG_SPACE(sizeof(struct in6_pktinfo))]; + struct cmsghdr align; + } control6; + union { + char buf[CMSG_SPACE(sizeof(struct in_pktinfo))]; + struct cmsghdr align; + } control4; + struct msghdr hdr; + struct iovec iov; + char data = 'a'; + int domain; + int fd = -1; + + domain = addr->ss_family; + + if (domain != AF_INET && domain != AF_INET6) { + log_err("Unsupported address family"); + goto err; + } + + fd = socket(domain, SOCK_DGRAM, 0); + if (fd == -1) { + log_err("Failed to create client socket"); + goto err; + } + + memset(&iov, 0, sizeof(iov)); + iov.iov_base = &data; + iov.iov_len = sizeof(data); + + memset(&hdr, 0, sizeof(hdr)); + hdr.msg_name = (void *)addr; + hdr.msg_namelen = addr_len; + hdr.msg_iov = &iov; + hdr.msg_iovlen = 1; + + if (set_cmsg) { + if (domain == AF_INET) { + hdr.msg_control = &control4; + hdr.msg_controllen = sizeof(control4.buf); + } else if (domain == AF_INET6) { + hdr.msg_control = &control6; + hdr.msg_controllen = sizeof(control6.buf); + } + if (init_pktinfo(domain, CMSG_FIRSTHDR(&hdr))) { + log_err("Fail to init pktinfo"); + goto err; + } + } + + if (sendmsg(fd, &hdr, 0) != sizeof(data)) { + log_err("Fail to send message to server"); + *syscall_err = errno; + goto err; + } + + goto out; +err: + close(fd); + fd = -1; +out: + return fd; +} + +static int recvmsg_from_client(int sockfd, struct sockaddr_storage *src_addr) +{ + struct timeval tv; + struct msghdr hdr; + struct iovec iov; + char data[64]; + fd_set rfds; + + FD_ZERO(&rfds); + FD_SET(sockfd, &rfds); + + tv.tv_sec = 2; + tv.tv_usec = 0; + + if (select(sockfd + 1, &rfds, NULL, NULL, &tv) <= 0 || + !FD_ISSET(sockfd, &rfds)) + return -1; + + memset(&iov, 0, sizeof(iov)); + iov.iov_base = data; + iov.iov_len = sizeof(data); + + memset(&hdr, 0, sizeof(hdr)); + hdr.msg_name = src_addr; + hdr.msg_namelen = sizeof(struct sockaddr_storage); + hdr.msg_iov = &iov; + hdr.msg_iovlen = 1; + + return recvmsg(sockfd, &hdr, 0); +} + static int init_addrs(const struct sock_addr_test *test, struct sockaddr_storage *requested_addr, struct sockaddr_storage *expected_addr, @@ -753,6 +1194,69 @@ out: return err; } +static int run_sendmsg_test_case(const struct sock_addr_test *test) +{ + socklen_t addr_len = sizeof(struct sockaddr_storage); + struct sockaddr_storage expected_src_addr; + struct sockaddr_storage requested_addr; + struct sockaddr_storage expected_addr; + struct sockaddr_storage real_src_addr; + int clientfd = -1; + int servfd = -1; + int set_cmsg; + int err = 0; + + if (test->type != SOCK_DGRAM) + goto err; + + if (init_addrs(test, &requested_addr, &expected_addr, + &expected_src_addr)) + goto err; + + /* Prepare server to sendmsg to */ + servfd = start_server(test->type, &expected_addr, addr_len); + if (servfd == -1) + goto err; + + for (set_cmsg = 0; set_cmsg <= 1; ++set_cmsg) { + if (clientfd >= 0) + close(clientfd); + + clientfd = sendmsg_to_server(&requested_addr, addr_len, + set_cmsg, &err); + if (err) + goto out; + else if (clientfd == -1) + goto err; + + /* Try to receive message on server instead of using + * getpeername(2) on client socket, to check that client's + * destination address was rewritten properly, since + * getpeername(2) doesn't work with unconnected datagram + * sockets. + * + * Get source address from recvmsg(2) as well to make sure + * source was rewritten properly: getsockname(2) can't be used + * since socket is unconnected and source defined for one + * specific packet may differ from the one used by default and + * returned by getsockname(2). + */ + if (recvmsg_from_client(servfd, &real_src_addr) == -1) + goto err; + + if (cmp_addr(&real_src_addr, &expected_src_addr, /*cmp_port*/0)) + goto err; + } + + goto out; +err: + err = -1; +out: + close(clientfd); + close(servfd); + return err; +} + static int run_test_case(int cgfd, const struct sock_addr_test *test) { int progfd = -1; @@ -784,10 +1288,24 @@ static int run_test_case(int cgfd, const struct sock_addr_test *test) case BPF_CGROUP_INET6_CONNECT: err = run_connect_test_case(test); break; + case BPF_CGROUP_UDP4_SENDMSG: + case BPF_CGROUP_UDP6_SENDMSG: + err = run_sendmsg_test_case(test); + break; default: goto err; } + if (test->expected_result == SYSCALL_EPERM && err == EPERM) { + err = 0; /* error was expected, reset it */ + goto out; + } + + if (test->expected_result == SYSCALL_ENOTSUPP && err == ENOTSUPP) { + err = 0; /* error was expected, reset it */ + goto out; + } + if (err || test->expected_result != SUCCESS) goto err; -- 2.7.4