// SPDX-License-Identifier: GPL-2.0 /* Test that sockets listening on a specific address are preferred * over sockets listening on addr_any. */ #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef SOL_DCCP #define SOL_DCCP 269 #endif static const char *IP4_ADDR = "127.0.0.1"; static const char *IP6_ADDR = "::1"; static const char *IP4_MAPPED6 = "::ffff:127.0.0.1"; static const int PORT = 8888; static void build_rcv_fd(int family, int proto, int *rcv_fds, int count, const char *addr_str) { struct sockaddr_in addr4 = {0}; struct sockaddr_in6 addr6 = {0}; struct sockaddr *addr; int opt, i, sz; memset(&addr, 0, sizeof(addr)); switch (family) { case AF_INET: addr4.sin_family = family; if (!addr_str) addr4.sin_addr.s_addr = htonl(INADDR_ANY); else if (!inet_pton(family, addr_str, &addr4.sin_addr.s_addr)) error(1, errno, "inet_pton failed: %s", addr_str); addr4.sin_port = htons(PORT); sz = sizeof(addr4); addr = (struct sockaddr *)&addr4; break; case AF_INET6: addr6.sin6_family = AF_INET6; if (!addr_str) addr6.sin6_addr = in6addr_any; else if (!inet_pton(family, addr_str, &addr6.sin6_addr)) error(1, errno, "inet_pton failed: %s", addr_str); addr6.sin6_port = htons(PORT); sz = sizeof(addr6); addr = (struct sockaddr *)&addr6; break; default: error(1, 0, "Unsupported family %d", family); /* clang does not recognize error() above as terminating * the program, so it complains that saddr, sz are * not initialized when this code path is taken. Silence it. */ return; } for (i = 0; i < count; ++i) { rcv_fds[i] = socket(family, proto, 0); if (rcv_fds[i] < 0) error(1, errno, "failed to create receive socket"); opt = 1; if (setsockopt(rcv_fds[i], SOL_SOCKET, SO_REUSEPORT, &opt, sizeof(opt))) error(1, errno, "failed to set SO_REUSEPORT"); if (bind(rcv_fds[i], addr, sz)) error(1, errno, "failed to bind receive socket"); if (proto == SOCK_STREAM && listen(rcv_fds[i], 10)) error(1, errno, "tcp: failed to listen on receive port"); else if (proto == SOCK_DCCP) { if (setsockopt(rcv_fds[i], SOL_DCCP, DCCP_SOCKOPT_SERVICE, &(int) {htonl(42)}, sizeof(int))) error(1, errno, "failed to setsockopt"); if (listen(rcv_fds[i], 10)) error(1, errno, "dccp: failed to listen on receive port"); } } } static int connect_and_send(int family, int proto) { struct sockaddr_in saddr4 = {0}; struct sockaddr_in daddr4 = {0}; struct sockaddr_in6 saddr6 = {0}; struct sockaddr_in6 daddr6 = {0}; struct sockaddr *saddr, *daddr; int fd, sz; switch (family) { case AF_INET: saddr4.sin_family = AF_INET; saddr4.sin_addr.s_addr = htonl(INADDR_ANY); saddr4.sin_port = 0; daddr4.sin_family = AF_INET; if (!inet_pton(family, IP4_ADDR, &daddr4.sin_addr.s_addr)) error(1, errno, "inet_pton failed: %s", IP4_ADDR); daddr4.sin_port = htons(PORT); sz = sizeof(saddr4); saddr = (struct sockaddr *)&saddr4; daddr = (struct sockaddr *)&daddr4; break; case AF_INET6: saddr6.sin6_family = AF_INET6; saddr6.sin6_addr = in6addr_any; daddr6.sin6_family = AF_INET6; if (!inet_pton(family, IP6_ADDR, &daddr6.sin6_addr)) error(1, errno, "inet_pton failed: %s", IP6_ADDR); daddr6.sin6_port = htons(PORT); sz = sizeof(saddr6); saddr = (struct sockaddr *)&saddr6; daddr = (struct sockaddr *)&daddr6; break; default: error(1, 0, "Unsupported family %d", family); /* clang does not recognize error() above as terminating * the program, so it complains that saddr, daddr, sz are * not initialized when this code path is taken. Silence it. */ return -1; } fd = socket(family, proto, 0); if (fd < 0) error(1, errno, "failed to create send socket"); if (proto == SOCK_DCCP && setsockopt(fd, SOL_DCCP, DCCP_SOCKOPT_SERVICE, &(int){htonl(42)}, sizeof(int))) error(1, errno, "failed to setsockopt"); if (bind(fd, saddr, sz)) error(1, errno, "failed to bind send socket"); if (connect(fd, daddr, sz)) error(1, errno, "failed to connect send socket"); if (send(fd, "a", 1, 0) < 0) error(1, errno, "failed to send message"); return fd; } static int receive_once(int epfd, int proto) { struct epoll_event ev; int i, fd; char buf[8]; i = epoll_wait(epfd, &ev, 1, 3); if (i < 0) error(1, errno, "epoll_wait failed"); if (proto == SOCK_STREAM || proto == SOCK_DCCP) { fd = accept(ev.data.fd, NULL, NULL); if (fd < 0) error(1, errno, "failed to accept"); i = recv(fd, buf, sizeof(buf), 0); close(fd); } else { i = recv(ev.data.fd, buf, sizeof(buf), 0); } if (i < 0) error(1, errno, "failed to recv"); return ev.data.fd; } static void test(int *rcv_fds, int count, int family, int proto, int fd) { struct epoll_event ev; int epfd, i, send_fd, recv_fd; epfd = epoll_create(1); if (epfd < 0) error(1, errno, "failed to create epoll"); ev.events = EPOLLIN; for (i = 0; i < count; ++i) { ev.data.fd = rcv_fds[i]; if (epoll_ctl(epfd, EPOLL_CTL_ADD, rcv_fds[i], &ev)) error(1, errno, "failed to register sock epoll"); } send_fd = connect_and_send(family, proto); recv_fd = receive_once(epfd, proto); if (recv_fd != fd) error(1, 0, "received on an unexpected socket"); close(send_fd); close(epfd); } static void run_one_test(int fam_send, int fam_rcv, int proto, const char *addr_str) { /* Below we test that a socket listening on a specific address * is always selected in preference over a socket listening * on addr_any. Bugs where this is not the case often result * in sockets created first or last to get picked. So below * we make sure that there are always addr_any sockets created * before and after a specific socket is created. */ int rcv_fds[10], i; build_rcv_fd(AF_INET, proto, rcv_fds, 2, NULL); build_rcv_fd(AF_INET6, proto, rcv_fds + 2, 2, NULL); build_rcv_fd(fam_rcv, proto, rcv_fds + 4, 1, addr_str); build_rcv_fd(AF_INET, proto, rcv_fds + 5, 2, NULL); build_rcv_fd(AF_INET6, proto, rcv_fds + 7, 2, NULL); test(rcv_fds, 9, fam_send, proto, rcv_fds[4]); for (i = 0; i < 9; ++i) close(rcv_fds[i]); fprintf(stderr, "pass\n"); } static void test_proto(int proto, const char *proto_str) { if (proto == SOCK_DCCP) { int test_fd; test_fd = socket(AF_INET, proto, 0); if (test_fd < 0) { if (errno == ESOCKTNOSUPPORT) { fprintf(stderr, "DCCP not supported: skipping DCCP tests\n"); return; } else error(1, errno, "failed to create a DCCP socket"); } close(test_fd); } fprintf(stderr, "%s IPv4 ... ", proto_str); run_one_test(AF_INET, AF_INET, proto, IP4_ADDR); fprintf(stderr, "%s IPv6 ... ", proto_str); run_one_test(AF_INET6, AF_INET6, proto, IP6_ADDR); fprintf(stderr, "%s IPv4 mapped to IPv6 ... ", proto_str); run_one_test(AF_INET, AF_INET6, proto, IP4_MAPPED6); } int main(void) { test_proto(SOCK_DGRAM, "UDP"); test_proto(SOCK_STREAM, "TCP"); test_proto(SOCK_DCCP, "DCCP"); fprintf(stderr, "SUCCESS\n"); return 0; }