// SPDX-License-Identifier: GPL-2.0 #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef ETH_MAX_MTU #define ETH_MAX_MTU 0xFFFFU #endif #ifndef UDP_SEGMENT #define UDP_SEGMENT 103 #endif #ifndef UDP_MAX_SEGMENTS #define UDP_MAX_SEGMENTS (1 << 7UL) #endif #define CONST_MTU_TEST 1500 #define CONST_HDRLEN_V4 (sizeof(struct iphdr) + sizeof(struct udphdr)) #define CONST_HDRLEN_V6 (sizeof(struct ip6_hdr) + sizeof(struct udphdr)) #define CONST_MSS_V4 (CONST_MTU_TEST - CONST_HDRLEN_V4) #define CONST_MSS_V6 (CONST_MTU_TEST - CONST_HDRLEN_V6) #define CONST_MAX_SEGS_V4 (ETH_MAX_MTU / CONST_MSS_V4) #define CONST_MAX_SEGS_V6 (ETH_MAX_MTU / CONST_MSS_V6) static bool cfg_do_ipv4; static bool cfg_do_ipv6; static bool cfg_do_connected; static bool cfg_do_connectionless; static bool cfg_do_msgmore; static bool cfg_do_setsockopt; static int cfg_specific_test_id = -1; static unsigned short cfg_port = 9000; static char buf[ETH_MAX_MTU]; struct testcase { int tlen; /* send() buffer size, may exceed mss */ bool tfail; /* send() call is expected to fail */ int gso_len; /* mss after applying gso */ int r_num_mss; /* recv(): number of calls of full mss */ int r_len_last; /* recv(): size of last non-mss dgram, if any */ }; const struct in6_addr addr6 = { { { 0xfd, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 } }, /* fd00::1 */ }; const struct in_addr addr4 = { __constant_htonl(0x0a000001), /* 10.0.0.1 */ }; struct testcase testcases_v4[] = { { /* no GSO: send a single byte */ .tlen = 1, .r_len_last = 1, }, { /* no GSO: send a single MSS */ .tlen = CONST_MSS_V4, .r_num_mss = 1, }, { /* no GSO: send a single MSS + 1B: fail */ .tlen = CONST_MSS_V4 + 1, .tfail = true, }, { /* send a single MSS: will fall back to no GSO */ .tlen = CONST_MSS_V4, .gso_len = CONST_MSS_V4, .r_num_mss = 1, }, { /* send a single MSS + 1B */ .tlen = CONST_MSS_V4 + 1, .gso_len = CONST_MSS_V4, .r_num_mss = 1, .r_len_last = 1, }, { /* send exactly 2 MSS */ .tlen = CONST_MSS_V4 * 2, .gso_len = CONST_MSS_V4, .r_num_mss = 2, }, { /* send 2 MSS + 1B */ .tlen = (CONST_MSS_V4 * 2) + 1, .gso_len = CONST_MSS_V4, .r_num_mss = 2, .r_len_last = 1, }, { /* send MAX segs */ .tlen = (ETH_MAX_MTU / CONST_MSS_V4) * CONST_MSS_V4, .gso_len = CONST_MSS_V4, .r_num_mss = (ETH_MAX_MTU / CONST_MSS_V4), }, { /* send MAX bytes */ .tlen = ETH_MAX_MTU - CONST_HDRLEN_V4, .gso_len = CONST_MSS_V4, .r_num_mss = CONST_MAX_SEGS_V4, .r_len_last = ETH_MAX_MTU - CONST_HDRLEN_V4 - (CONST_MAX_SEGS_V4 * CONST_MSS_V4), }, { /* send MAX + 1: fail */ .tlen = ETH_MAX_MTU - CONST_HDRLEN_V4 + 1, .gso_len = CONST_MSS_V4, .tfail = true, }, { /* send a single 1B MSS: will fall back to no GSO */ .tlen = 1, .gso_len = 1, .r_num_mss = 1, }, { /* send 2 1B segments */ .tlen = 2, .gso_len = 1, .r_num_mss = 2, }, { /* send 2B + 2B + 1B segments */ .tlen = 5, .gso_len = 2, .r_num_mss = 2, .r_len_last = 1, }, { /* send max number of min sized segments */ .tlen = UDP_MAX_SEGMENTS, .gso_len = 1, .r_num_mss = UDP_MAX_SEGMENTS, }, { /* send max number + 1 of min sized segments: fail */ .tlen = UDP_MAX_SEGMENTS + 1, .gso_len = 1, .tfail = true, }, { /* EOL */ } }; #ifndef IP6_MAX_MTU #define IP6_MAX_MTU (ETH_MAX_MTU + sizeof(struct ip6_hdr)) #endif struct testcase testcases_v6[] = { { /* no GSO: send a single byte */ .tlen = 1, .r_len_last = 1, }, { /* no GSO: send a single MSS */ .tlen = CONST_MSS_V6, .r_num_mss = 1, }, { /* no GSO: send a single MSS + 1B: fail */ .tlen = CONST_MSS_V6 + 1, .tfail = true, }, { /* send a single MSS: will fall back to no GSO */ .tlen = CONST_MSS_V6, .gso_len = CONST_MSS_V6, .r_num_mss = 1, }, { /* send a single MSS + 1B */ .tlen = CONST_MSS_V6 + 1, .gso_len = CONST_MSS_V6, .r_num_mss = 1, .r_len_last = 1, }, { /* send exactly 2 MSS */ .tlen = CONST_MSS_V6 * 2, .gso_len = CONST_MSS_V6, .r_num_mss = 2, }, { /* send 2 MSS + 1B */ .tlen = (CONST_MSS_V6 * 2) + 1, .gso_len = CONST_MSS_V6, .r_num_mss = 2, .r_len_last = 1, }, { /* send MAX segs */ .tlen = (IP6_MAX_MTU / CONST_MSS_V6) * CONST_MSS_V6, .gso_len = CONST_MSS_V6, .r_num_mss = (IP6_MAX_MTU / CONST_MSS_V6), }, { /* send MAX bytes */ .tlen = IP6_MAX_MTU - CONST_HDRLEN_V6, .gso_len = CONST_MSS_V6, .r_num_mss = CONST_MAX_SEGS_V6, .r_len_last = IP6_MAX_MTU - CONST_HDRLEN_V6 - (CONST_MAX_SEGS_V6 * CONST_MSS_V6), }, { /* send MAX + 1: fail */ .tlen = IP6_MAX_MTU - CONST_HDRLEN_V6 + 1, .gso_len = CONST_MSS_V6, .tfail = true, }, { /* send a single 1B MSS: will fall back to no GSO */ .tlen = 1, .gso_len = 1, .r_num_mss = 1, }, { /* send 2 1B segments */ .tlen = 2, .gso_len = 1, .r_num_mss = 2, }, { /* send 2B + 2B + 1B segments */ .tlen = 5, .gso_len = 2, .r_num_mss = 2, .r_len_last = 1, }, { /* send max number of min sized segments */ .tlen = UDP_MAX_SEGMENTS, .gso_len = 1, .r_num_mss = UDP_MAX_SEGMENTS, }, { /* send max number + 1 of min sized segments: fail */ .tlen = UDP_MAX_SEGMENTS + 1, .gso_len = 1, .tfail = true, }, { /* EOL */ } }; static void set_pmtu_discover(int fd, bool is_ipv4) { int level, name, val; if (is_ipv4) { level = SOL_IP; name = IP_MTU_DISCOVER; val = IP_PMTUDISC_DO; } else { level = SOL_IPV6; name = IPV6_MTU_DISCOVER; val = IPV6_PMTUDISC_DO; } if (setsockopt(fd, level, name, &val, sizeof(val))) error(1, errno, "setsockopt path mtu"); } static unsigned int get_path_mtu(int fd, bool is_ipv4) { socklen_t vallen; unsigned int mtu; int ret; vallen = sizeof(mtu); if (is_ipv4) ret = getsockopt(fd, SOL_IP, IP_MTU, &mtu, &vallen); else ret = getsockopt(fd, SOL_IPV6, IPV6_MTU, &mtu, &vallen); if (ret) error(1, errno, "getsockopt mtu"); fprintf(stderr, "path mtu (read): %u\n", mtu); return mtu; } static bool __send_one(int fd, struct msghdr *msg, int flags) { int ret; ret = sendmsg(fd, msg, flags); if (ret == -1 && (errno == EMSGSIZE || errno == ENOMEM || errno == EINVAL)) return false; if (ret == -1) error(1, errno, "sendmsg"); if (ret != msg->msg_iov->iov_len) error(1, 0, "sendto: %d != %llu", ret, (unsigned long long)msg->msg_iov->iov_len); if (msg->msg_flags) error(1, 0, "sendmsg: return flags 0x%x\n", msg->msg_flags); return true; } static bool send_one(int fd, int len, int gso_len, struct sockaddr *addr, socklen_t alen) { char control[CMSG_SPACE(sizeof(uint16_t))] = {0}; struct msghdr msg = {0}; struct iovec iov = {0}; struct cmsghdr *cm; iov.iov_base = buf; iov.iov_len = len; msg.msg_iov = &iov; msg.msg_iovlen = 1; msg.msg_name = addr; msg.msg_namelen = alen; if (gso_len && !cfg_do_setsockopt) { msg.msg_control = control; msg.msg_controllen = sizeof(control); cm = CMSG_FIRSTHDR(&msg); cm->cmsg_level = SOL_UDP; cm->cmsg_type = UDP_SEGMENT; cm->cmsg_len = CMSG_LEN(sizeof(uint16_t)); *((uint16_t *) CMSG_DATA(cm)) = gso_len; } /* If MSG_MORE, send 1 byte followed by remainder */ if (cfg_do_msgmore && len > 1) { iov.iov_len = 1; if (!__send_one(fd, &msg, MSG_MORE)) error(1, 0, "send 1B failed"); iov.iov_base++; iov.iov_len = len - 1; } return __send_one(fd, &msg, 0); } static int recv_one(int fd, int flags) { int ret; ret = recv(fd, buf, sizeof(buf), flags); if (ret == -1 && errno == EAGAIN && (flags & MSG_DONTWAIT)) return 0; if (ret == -1) error(1, errno, "recv"); return ret; } static void run_one(struct testcase *test, int fdt, int fdr, struct sockaddr *addr, socklen_t alen) { int i, ret, val, mss; bool sent; fprintf(stderr, "ipv%d tx:%d gso:%d %s\n", addr->sa_family == AF_INET ? 4 : 6, test->tlen, test->gso_len, test->tfail ? "(fail)" : ""); val = test->gso_len; if (cfg_do_setsockopt) { if (setsockopt(fdt, SOL_UDP, UDP_SEGMENT, &val, sizeof(val))) error(1, errno, "setsockopt udp segment"); } sent = send_one(fdt, test->tlen, test->gso_len, addr, alen); if (sent && test->tfail) error(1, 0, "send succeeded while expecting failure"); if (!sent && !test->tfail) error(1, 0, "send failed while expecting success"); if (!sent) return; if (test->gso_len) mss = test->gso_len; else mss = addr->sa_family == AF_INET ? CONST_MSS_V4 : CONST_MSS_V6; /* Recv all full MSS datagrams */ for (i = 0; i < test->r_num_mss; i++) { ret = recv_one(fdr, 0); if (ret != mss) error(1, 0, "recv.%d: %d != %d", i, ret, mss); } /* Recv the non-full last datagram, if tlen was not a multiple of mss */ if (test->r_len_last) { ret = recv_one(fdr, 0); if (ret != test->r_len_last) error(1, 0, "recv.%d: %d != %d (last)", i, ret, test->r_len_last); } /* Verify received all data */ ret = recv_one(fdr, MSG_DONTWAIT); if (ret) error(1, 0, "recv: unexpected datagram"); } static void run_all(int fdt, int fdr, struct sockaddr *addr, socklen_t alen) { struct testcase *tests, *test; tests = addr->sa_family == AF_INET ? testcases_v4 : testcases_v6; for (test = tests; test->tlen; test++) { /* if a specific test is given, then skip all others */ if (cfg_specific_test_id == -1 || cfg_specific_test_id == test - tests) run_one(test, fdt, fdr, addr, alen); } } static void run_test(struct sockaddr *addr, socklen_t alen) { struct timeval tv = { .tv_usec = 100 * 1000 }; int fdr, fdt, val; fdr = socket(addr->sa_family, SOCK_DGRAM, 0); if (fdr == -1) error(1, errno, "socket r"); if (bind(fdr, addr, alen)) error(1, errno, "bind"); /* Have tests fail quickly instead of hang */ if (setsockopt(fdr, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv))) error(1, errno, "setsockopt rcv timeout"); fdt = socket(addr->sa_family, SOCK_DGRAM, 0); if (fdt == -1) error(1, errno, "socket t"); /* Do not fragment these datagrams: only succeed if GSO works */ set_pmtu_discover(fdt, addr->sa_family == AF_INET); if (cfg_do_connectionless) run_all(fdt, fdr, addr, alen); if (cfg_do_connected) { if (connect(fdt, addr, alen)) error(1, errno, "connect"); val = get_path_mtu(fdt, addr->sa_family == AF_INET); if (val != CONST_MTU_TEST) error(1, 0, "bad path mtu %u\n", val); run_all(fdt, fdr, addr, 0 /* use connected addr */); } if (close(fdt)) error(1, errno, "close t"); if (close(fdr)) error(1, errno, "close r"); } static void run_test_v4(void) { struct sockaddr_in addr = {0}; addr.sin_family = AF_INET; addr.sin_port = htons(cfg_port); addr.sin_addr = addr4; run_test((void *)&addr, sizeof(addr)); } static void run_test_v6(void) { struct sockaddr_in6 addr = {0}; addr.sin6_family = AF_INET6; addr.sin6_port = htons(cfg_port); addr.sin6_addr = addr6; run_test((void *)&addr, sizeof(addr)); } static void parse_opts(int argc, char **argv) { int c; while ((c = getopt(argc, argv, "46cCmst:")) != -1) { switch (c) { case '4': cfg_do_ipv4 = true; break; case '6': cfg_do_ipv6 = true; break; case 'c': cfg_do_connected = true; break; case 'C': cfg_do_connectionless = true; break; case 'm': cfg_do_msgmore = true; break; case 's': cfg_do_setsockopt = true; break; case 't': cfg_specific_test_id = strtoul(optarg, NULL, 0); break; default: error(1, 0, "%s: parse error", argv[0]); } } } int main(int argc, char **argv) { parse_opts(argc, argv); if (cfg_do_ipv4) run_test_v4(); if (cfg_do_ipv6) run_test_v6(); fprintf(stderr, "OK\n"); return 0; }