1 // SPDX-License-Identifier: GPL-2.0 2 3 /* Test that sockets listening on a specific address are preferred 4 * over sockets listening on addr_any. 5 */ 6 7 #define _GNU_SOURCE 8 9 #include <arpa/inet.h> 10 #include <errno.h> 11 #include <error.h> 12 #include <linux/dccp.h> 13 #include <linux/in.h> 14 #include <linux/unistd.h> 15 #include <stdbool.h> 16 #include <stdio.h> 17 #include <stdlib.h> 18 #include <string.h> 19 #include <sys/epoll.h> 20 #include <sys/types.h> 21 #include <sys/socket.h> 22 #include <unistd.h> 23 24 #ifndef SOL_DCCP 25 #define SOL_DCCP 269 26 #endif 27 28 static const char *IP4_ADDR = "127.0.0.1"; 29 static const char *IP6_ADDR = "::1"; 30 static const char *IP4_MAPPED6 = "::ffff:127.0.0.1"; 31 32 static const int PORT = 8888; 33 34 static void build_rcv_fd(int family, int proto, int *rcv_fds, int count, 35 const char *addr_str) 36 { 37 struct sockaddr_in addr4 = {0}; 38 struct sockaddr_in6 addr6 = {0}; 39 struct sockaddr *addr; 40 int opt, i, sz; 41 42 memset(&addr, 0, sizeof(addr)); 43 44 switch (family) { 45 case AF_INET: 46 addr4.sin_family = family; 47 if (!addr_str) 48 addr4.sin_addr.s_addr = htonl(INADDR_ANY); 49 else if (!inet_pton(family, addr_str, &addr4.sin_addr.s_addr)) 50 error(1, errno, "inet_pton failed: %s", addr_str); 51 addr4.sin_port = htons(PORT); 52 sz = sizeof(addr4); 53 addr = (struct sockaddr *)&addr4; 54 break; 55 case AF_INET6: 56 addr6.sin6_family = AF_INET6; 57 if (!addr_str) 58 addr6.sin6_addr = in6addr_any; 59 else if (!inet_pton(family, addr_str, &addr6.sin6_addr)) 60 error(1, errno, "inet_pton failed: %s", addr_str); 61 addr6.sin6_port = htons(PORT); 62 sz = sizeof(addr6); 63 addr = (struct sockaddr *)&addr6; 64 break; 65 default: 66 error(1, 0, "Unsupported family %d", family); 67 /* clang does not recognize error() above as terminating 68 * the program, so it complains that saddr, sz are 69 * not initialized when this code path is taken. Silence it. 70 */ 71 return; 72 } 73 74 for (i = 0; i < count; ++i) { 75 rcv_fds[i] = socket(family, proto, 0); 76 if (rcv_fds[i] < 0) 77 error(1, errno, "failed to create receive socket"); 78 79 opt = 1; 80 if (setsockopt(rcv_fds[i], SOL_SOCKET, SO_REUSEPORT, &opt, 81 sizeof(opt))) 82 error(1, errno, "failed to set SO_REUSEPORT"); 83 84 if (bind(rcv_fds[i], addr, sz)) 85 error(1, errno, "failed to bind receive socket"); 86 87 if (proto == SOCK_STREAM && listen(rcv_fds[i], 10)) 88 error(1, errno, "tcp: failed to listen on receive port"); 89 else if (proto == SOCK_DCCP) { 90 if (setsockopt(rcv_fds[i], SOL_DCCP, 91 DCCP_SOCKOPT_SERVICE, 92 &(int) {htonl(42)}, sizeof(int))) 93 error(1, errno, "failed to setsockopt"); 94 95 if (listen(rcv_fds[i], 10)) 96 error(1, errno, "dccp: failed to listen on receive port"); 97 } 98 } 99 } 100 101 static int connect_and_send(int family, int proto) 102 { 103 struct sockaddr_in saddr4 = {0}; 104 struct sockaddr_in daddr4 = {0}; 105 struct sockaddr_in6 saddr6 = {0}; 106 struct sockaddr_in6 daddr6 = {0}; 107 struct sockaddr *saddr, *daddr; 108 int fd, sz; 109 110 switch (family) { 111 case AF_INET: 112 saddr4.sin_family = AF_INET; 113 saddr4.sin_addr.s_addr = htonl(INADDR_ANY); 114 saddr4.sin_port = 0; 115 116 daddr4.sin_family = AF_INET; 117 if (!inet_pton(family, IP4_ADDR, &daddr4.sin_addr.s_addr)) 118 error(1, errno, "inet_pton failed: %s", IP4_ADDR); 119 daddr4.sin_port = htons(PORT); 120 121 sz = sizeof(saddr4); 122 saddr = (struct sockaddr *)&saddr4; 123 daddr = (struct sockaddr *)&daddr4; 124 break; 125 case AF_INET6: 126 saddr6.sin6_family = AF_INET6; 127 saddr6.sin6_addr = in6addr_any; 128 129 daddr6.sin6_family = AF_INET6; 130 if (!inet_pton(family, IP6_ADDR, &daddr6.sin6_addr)) 131 error(1, errno, "inet_pton failed: %s", IP6_ADDR); 132 daddr6.sin6_port = htons(PORT); 133 134 sz = sizeof(saddr6); 135 saddr = (struct sockaddr *)&saddr6; 136 daddr = (struct sockaddr *)&daddr6; 137 break; 138 default: 139 error(1, 0, "Unsupported family %d", family); 140 /* clang does not recognize error() above as terminating 141 * the program, so it complains that saddr, daddr, sz are 142 * not initialized when this code path is taken. Silence it. 143 */ 144 return -1; 145 } 146 147 fd = socket(family, proto, 0); 148 if (fd < 0) 149 error(1, errno, "failed to create send socket"); 150 151 if (proto == SOCK_DCCP && 152 setsockopt(fd, SOL_DCCP, DCCP_SOCKOPT_SERVICE, 153 &(int){htonl(42)}, sizeof(int))) 154 error(1, errno, "failed to setsockopt"); 155 156 if (bind(fd, saddr, sz)) 157 error(1, errno, "failed to bind send socket"); 158 159 if (connect(fd, daddr, sz)) 160 error(1, errno, "failed to connect send socket"); 161 162 if (send(fd, "a", 1, 0) < 0) 163 error(1, errno, "failed to send message"); 164 165 return fd; 166 } 167 168 static int receive_once(int epfd, int proto) 169 { 170 struct epoll_event ev; 171 int i, fd; 172 char buf[8]; 173 174 i = epoll_wait(epfd, &ev, 1, 3); 175 if (i < 0) 176 error(1, errno, "epoll_wait failed"); 177 178 if (proto == SOCK_STREAM || proto == SOCK_DCCP) { 179 fd = accept(ev.data.fd, NULL, NULL); 180 if (fd < 0) 181 error(1, errno, "failed to accept"); 182 i = recv(fd, buf, sizeof(buf), 0); 183 close(fd); 184 } else { 185 i = recv(ev.data.fd, buf, sizeof(buf), 0); 186 } 187 188 if (i < 0) 189 error(1, errno, "failed to recv"); 190 191 return ev.data.fd; 192 } 193 194 static void test(int *rcv_fds, int count, int family, int proto, int fd) 195 { 196 struct epoll_event ev; 197 int epfd, i, send_fd, recv_fd; 198 199 epfd = epoll_create(1); 200 if (epfd < 0) 201 error(1, errno, "failed to create epoll"); 202 203 ev.events = EPOLLIN; 204 for (i = 0; i < count; ++i) { 205 ev.data.fd = rcv_fds[i]; 206 if (epoll_ctl(epfd, EPOLL_CTL_ADD, rcv_fds[i], &ev)) 207 error(1, errno, "failed to register sock epoll"); 208 } 209 210 send_fd = connect_and_send(family, proto); 211 212 recv_fd = receive_once(epfd, proto); 213 if (recv_fd != fd) 214 error(1, 0, "received on an unexpected socket"); 215 216 close(send_fd); 217 close(epfd); 218 } 219 220 221 static void run_one_test(int fam_send, int fam_rcv, int proto, 222 const char *addr_str) 223 { 224 /* Below we test that a socket listening on a specific address 225 * is always selected in preference over a socket listening 226 * on addr_any. Bugs where this is not the case often result 227 * in sockets created first or last to get picked. So below 228 * we make sure that there are always addr_any sockets created 229 * before and after a specific socket is created. 230 */ 231 int rcv_fds[10], i; 232 233 build_rcv_fd(AF_INET, proto, rcv_fds, 2, NULL); 234 build_rcv_fd(AF_INET6, proto, rcv_fds + 2, 2, NULL); 235 build_rcv_fd(fam_rcv, proto, rcv_fds + 4, 1, addr_str); 236 build_rcv_fd(AF_INET, proto, rcv_fds + 5, 2, NULL); 237 build_rcv_fd(AF_INET6, proto, rcv_fds + 7, 2, NULL); 238 test(rcv_fds, 9, fam_send, proto, rcv_fds[4]); 239 for (i = 0; i < 9; ++i) 240 close(rcv_fds[i]); 241 fprintf(stderr, "pass\n"); 242 } 243 244 static void test_proto(int proto, const char *proto_str) 245 { 246 if (proto == SOCK_DCCP) { 247 int test_fd; 248 249 test_fd = socket(AF_INET, proto, 0); 250 if (test_fd < 0) { 251 if (errno == ESOCKTNOSUPPORT) { 252 fprintf(stderr, "DCCP not supported: skipping DCCP tests\n"); 253 return; 254 } else 255 error(1, errno, "failed to create a DCCP socket"); 256 } 257 close(test_fd); 258 } 259 260 fprintf(stderr, "%s IPv4 ... ", proto_str); 261 run_one_test(AF_INET, AF_INET, proto, IP4_ADDR); 262 263 fprintf(stderr, "%s IPv6 ... ", proto_str); 264 run_one_test(AF_INET6, AF_INET6, proto, IP6_ADDR); 265 266 fprintf(stderr, "%s IPv4 mapped to IPv6 ... ", proto_str); 267 run_one_test(AF_INET, AF_INET6, proto, IP4_MAPPED6); 268 } 269 270 int main(void) 271 { 272 test_proto(SOCK_DGRAM, "UDP"); 273 test_proto(SOCK_STREAM, "TCP"); 274 test_proto(SOCK_DCCP, "DCCP"); 275 276 fprintf(stderr, "SUCCESS\n"); 277 return 0; 278 } 279