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 static const char *IP4_ADDR = "127.0.0.1"; 25 static const char *IP6_ADDR = "::1"; 26 static const char *IP4_MAPPED6 = "::ffff:127.0.0.1"; 27 28 static const int PORT = 8888; 29 30 static void build_rcv_fd(int family, int proto, int *rcv_fds, int count, 31 const char *addr_str) 32 { 33 struct sockaddr_in addr4 = {0}; 34 struct sockaddr_in6 addr6 = {0}; 35 struct sockaddr *addr; 36 int opt, i, sz; 37 38 memset(&addr, 0, sizeof(addr)); 39 40 switch (family) { 41 case AF_INET: 42 addr4.sin_family = family; 43 if (!addr_str) 44 addr4.sin_addr.s_addr = htonl(INADDR_ANY); 45 else if (!inet_pton(family, addr_str, &addr4.sin_addr.s_addr)) 46 error(1, errno, "inet_pton failed: %s", addr_str); 47 addr4.sin_port = htons(PORT); 48 sz = sizeof(addr4); 49 addr = (struct sockaddr *)&addr4; 50 break; 51 case AF_INET6: 52 addr6.sin6_family = AF_INET6; 53 if (!addr_str) 54 addr6.sin6_addr = in6addr_any; 55 else if (!inet_pton(family, addr_str, &addr6.sin6_addr)) 56 error(1, errno, "inet_pton failed: %s", addr_str); 57 addr6.sin6_port = htons(PORT); 58 sz = sizeof(addr6); 59 addr = (struct sockaddr *)&addr6; 60 break; 61 default: 62 error(1, 0, "Unsupported family %d", family); 63 } 64 65 for (i = 0; i < count; ++i) { 66 rcv_fds[i] = socket(family, proto, 0); 67 if (rcv_fds[i] < 0) 68 error(1, errno, "failed to create receive socket"); 69 70 opt = 1; 71 if (setsockopt(rcv_fds[i], SOL_SOCKET, SO_REUSEPORT, &opt, 72 sizeof(opt))) 73 error(1, errno, "failed to set SO_REUSEPORT"); 74 75 if (bind(rcv_fds[i], addr, sz)) 76 error(1, errno, "failed to bind receive socket"); 77 78 if (proto == SOCK_STREAM && listen(rcv_fds[i], 10)) 79 error(1, errno, "tcp: failed to listen on receive port"); 80 else if (proto == SOCK_DCCP) { 81 if (setsockopt(rcv_fds[i], SOL_DCCP, 82 DCCP_SOCKOPT_SERVICE, 83 &(int) {htonl(42)}, sizeof(int))) 84 error(1, errno, "failed to setsockopt"); 85 86 if (listen(rcv_fds[i], 10)) 87 error(1, errno, "dccp: failed to listen on receive port"); 88 } 89 } 90 } 91 92 static int connect_and_send(int family, int proto) 93 { 94 struct sockaddr_in saddr4 = {0}; 95 struct sockaddr_in daddr4 = {0}; 96 struct sockaddr_in6 saddr6 = {0}; 97 struct sockaddr_in6 daddr6 = {0}; 98 struct sockaddr *saddr, *daddr; 99 int fd, sz; 100 101 switch (family) { 102 case AF_INET: 103 saddr4.sin_family = AF_INET; 104 saddr4.sin_addr.s_addr = htonl(INADDR_ANY); 105 saddr4.sin_port = 0; 106 107 daddr4.sin_family = AF_INET; 108 if (!inet_pton(family, IP4_ADDR, &daddr4.sin_addr.s_addr)) 109 error(1, errno, "inet_pton failed: %s", IP4_ADDR); 110 daddr4.sin_port = htons(PORT); 111 112 sz = sizeof(saddr4); 113 saddr = (struct sockaddr *)&saddr4; 114 daddr = (struct sockaddr *)&daddr4; 115 break; 116 case AF_INET6: 117 saddr6.sin6_family = AF_INET6; 118 saddr6.sin6_addr = in6addr_any; 119 120 daddr6.sin6_family = AF_INET6; 121 if (!inet_pton(family, IP6_ADDR, &daddr6.sin6_addr)) 122 error(1, errno, "inet_pton failed: %s", IP6_ADDR); 123 daddr6.sin6_port = htons(PORT); 124 125 sz = sizeof(saddr6); 126 saddr = (struct sockaddr *)&saddr6; 127 daddr = (struct sockaddr *)&daddr6; 128 break; 129 default: 130 error(1, 0, "Unsupported family %d", family); 131 } 132 133 fd = socket(family, proto, 0); 134 if (fd < 0) 135 error(1, errno, "failed to create send socket"); 136 137 if (proto == SOCK_DCCP && 138 setsockopt(fd, SOL_DCCP, DCCP_SOCKOPT_SERVICE, 139 &(int){htonl(42)}, sizeof(int))) 140 error(1, errno, "failed to setsockopt"); 141 142 if (bind(fd, saddr, sz)) 143 error(1, errno, "failed to bind send socket"); 144 145 if (connect(fd, daddr, sz)) 146 error(1, errno, "failed to connect send socket"); 147 148 if (send(fd, "a", 1, 0) < 0) 149 error(1, errno, "failed to send message"); 150 151 return fd; 152 } 153 154 static int receive_once(int epfd, int proto) 155 { 156 struct epoll_event ev; 157 int i, fd; 158 char buf[8]; 159 160 i = epoll_wait(epfd, &ev, 1, 3); 161 if (i < 0) 162 error(1, errno, "epoll_wait failed"); 163 164 if (proto == SOCK_STREAM || proto == SOCK_DCCP) { 165 fd = accept(ev.data.fd, NULL, NULL); 166 if (fd < 0) 167 error(1, errno, "failed to accept"); 168 i = recv(fd, buf, sizeof(buf), 0); 169 close(fd); 170 } else { 171 i = recv(ev.data.fd, buf, sizeof(buf), 0); 172 } 173 174 if (i < 0) 175 error(1, errno, "failed to recv"); 176 177 return ev.data.fd; 178 } 179 180 static void test(int *rcv_fds, int count, int family, int proto, int fd) 181 { 182 struct epoll_event ev; 183 int epfd, i, send_fd, recv_fd; 184 185 epfd = epoll_create(1); 186 if (epfd < 0) 187 error(1, errno, "failed to create epoll"); 188 189 ev.events = EPOLLIN; 190 for (i = 0; i < count; ++i) { 191 ev.data.fd = rcv_fds[i]; 192 if (epoll_ctl(epfd, EPOLL_CTL_ADD, rcv_fds[i], &ev)) 193 error(1, errno, "failed to register sock epoll"); 194 } 195 196 send_fd = connect_and_send(family, proto); 197 198 recv_fd = receive_once(epfd, proto); 199 if (recv_fd != fd) 200 error(1, 0, "received on an unexpected socket"); 201 202 close(send_fd); 203 close(epfd); 204 } 205 206 int main(void) 207 { 208 /* Below we test that a socket listening on a specific address 209 * is always selected in preference over a socket listening 210 * on addr_any. Bugs where this is not the case often result 211 * in sockets created first or last to get picked. So below 212 * we make sure that there are always addr_any sockets created 213 * before and after a specific socket is created. 214 */ 215 int rcv_fds[10], i; 216 217 fprintf(stderr, "---- UDP IPv4 ----\n"); 218 build_rcv_fd(AF_INET, SOCK_DGRAM, rcv_fds, 2, NULL); 219 build_rcv_fd(AF_INET6, SOCK_DGRAM, rcv_fds + 2, 2, NULL); 220 build_rcv_fd(AF_INET, SOCK_DGRAM, rcv_fds + 4, 1, IP4_ADDR); 221 build_rcv_fd(AF_INET, SOCK_DGRAM, rcv_fds + 5, 2, NULL); 222 build_rcv_fd(AF_INET6, SOCK_DGRAM, rcv_fds + 7, 2, NULL); 223 test(rcv_fds, 9, AF_INET, SOCK_DGRAM, rcv_fds[4]); 224 for (i = 0; i < 9; ++i) 225 close(rcv_fds[i]); 226 227 fprintf(stderr, "---- UDP IPv6 ----\n"); 228 build_rcv_fd(AF_INET, SOCK_DGRAM, rcv_fds, 2, NULL); 229 build_rcv_fd(AF_INET6, SOCK_DGRAM, rcv_fds + 2, 2, NULL); 230 build_rcv_fd(AF_INET6, SOCK_DGRAM, rcv_fds + 4, 1, IP6_ADDR); 231 build_rcv_fd(AF_INET, SOCK_DGRAM, rcv_fds + 5, 2, NULL); 232 build_rcv_fd(AF_INET6, SOCK_DGRAM, rcv_fds + 7, 2, NULL); 233 test(rcv_fds, 9, AF_INET6, SOCK_DGRAM, rcv_fds[4]); 234 for (i = 0; i < 9; ++i) 235 close(rcv_fds[i]); 236 237 fprintf(stderr, "---- UDP IPv4 mapped to IPv6 ----\n"); 238 build_rcv_fd(AF_INET, SOCK_DGRAM, rcv_fds, 2, NULL); 239 build_rcv_fd(AF_INET6, SOCK_DGRAM, rcv_fds + 2, 2, NULL); 240 build_rcv_fd(AF_INET6, SOCK_DGRAM, rcv_fds + 4, 1, IP4_MAPPED6); 241 build_rcv_fd(AF_INET, SOCK_DGRAM, rcv_fds + 5, 2, NULL); 242 build_rcv_fd(AF_INET6, SOCK_DGRAM, rcv_fds + 7, 2, NULL); 243 test(rcv_fds, 9, AF_INET, SOCK_DGRAM, rcv_fds[4]); 244 for (i = 0; i < 9; ++i) 245 close(rcv_fds[i]); 246 247 fprintf(stderr, "---- TCP IPv4 ----\n"); 248 build_rcv_fd(AF_INET, SOCK_STREAM, rcv_fds, 2, NULL); 249 build_rcv_fd(AF_INET6, SOCK_STREAM, rcv_fds + 2, 2, NULL); 250 build_rcv_fd(AF_INET, SOCK_STREAM, rcv_fds + 4, 1, IP4_ADDR); 251 build_rcv_fd(AF_INET, SOCK_STREAM, rcv_fds + 5, 2, NULL); 252 build_rcv_fd(AF_INET6, SOCK_STREAM, rcv_fds + 7, 2, NULL); 253 test(rcv_fds, 9, AF_INET, SOCK_STREAM, rcv_fds[4]); 254 for (i = 0; i < 9; ++i) 255 close(rcv_fds[i]); 256 257 fprintf(stderr, "---- TCP IPv6 ----\n"); 258 build_rcv_fd(AF_INET, SOCK_STREAM, rcv_fds, 2, NULL); 259 build_rcv_fd(AF_INET6, SOCK_STREAM, rcv_fds + 2, 2, NULL); 260 build_rcv_fd(AF_INET6, SOCK_STREAM, rcv_fds + 4, 1, IP6_ADDR); 261 build_rcv_fd(AF_INET, SOCK_STREAM, rcv_fds + 5, 2, NULL); 262 build_rcv_fd(AF_INET6, SOCK_STREAM, rcv_fds + 7, 2, NULL); 263 test(rcv_fds, 9, AF_INET6, SOCK_STREAM, rcv_fds[4]); 264 for (i = 0; i < 9; ++i) 265 close(rcv_fds[i]); 266 267 fprintf(stderr, "---- TCP IPv4 mapped to IPv6 ----\n"); 268 build_rcv_fd(AF_INET, SOCK_STREAM, rcv_fds, 2, NULL); 269 build_rcv_fd(AF_INET6, SOCK_STREAM, rcv_fds + 2, 2, NULL); 270 build_rcv_fd(AF_INET6, SOCK_STREAM, rcv_fds + 4, 1, IP4_MAPPED6); 271 build_rcv_fd(AF_INET, SOCK_STREAM, rcv_fds + 5, 2, NULL); 272 build_rcv_fd(AF_INET6, SOCK_STREAM, rcv_fds + 7, 2, NULL); 273 test(rcv_fds, 9, AF_INET, SOCK_STREAM, rcv_fds[4]); 274 for (i = 0; i < 9; ++i) 275 close(rcv_fds[i]); 276 277 fprintf(stderr, "---- DCCP IPv4 ----\n"); 278 build_rcv_fd(AF_INET, SOCK_DCCP, rcv_fds, 2, NULL); 279 build_rcv_fd(AF_INET6, SOCK_DCCP, rcv_fds + 2, 2, NULL); 280 build_rcv_fd(AF_INET, SOCK_DCCP, rcv_fds + 4, 1, IP4_ADDR); 281 build_rcv_fd(AF_INET, SOCK_DCCP, rcv_fds + 5, 2, NULL); 282 build_rcv_fd(AF_INET6, SOCK_DCCP, rcv_fds + 7, 2, NULL); 283 test(rcv_fds, 9, AF_INET, SOCK_DCCP, rcv_fds[4]); 284 for (i = 0; i < 9; ++i) 285 close(rcv_fds[i]); 286 287 fprintf(stderr, "---- DCCP IPv6 ----\n"); 288 build_rcv_fd(AF_INET, SOCK_DCCP, rcv_fds, 2, NULL); 289 build_rcv_fd(AF_INET6, SOCK_DCCP, rcv_fds + 2, 2, NULL); 290 build_rcv_fd(AF_INET6, SOCK_DCCP, rcv_fds + 4, 1, IP6_ADDR); 291 build_rcv_fd(AF_INET, SOCK_DCCP, rcv_fds + 5, 2, NULL); 292 build_rcv_fd(AF_INET6, SOCK_DCCP, rcv_fds + 7, 2, NULL); 293 test(rcv_fds, 9, AF_INET6, SOCK_DCCP, rcv_fds[4]); 294 for (i = 0; i < 9; ++i) 295 close(rcv_fds[i]); 296 297 fprintf(stderr, "---- DCCP IPv4 mapped to IPv6 ----\n"); 298 build_rcv_fd(AF_INET, SOCK_DCCP, rcv_fds, 2, NULL); 299 build_rcv_fd(AF_INET6, SOCK_DCCP, rcv_fds + 2, 2, NULL); 300 build_rcv_fd(AF_INET6, SOCK_DCCP, rcv_fds + 4, 1, IP4_MAPPED6); 301 build_rcv_fd(AF_INET, SOCK_DCCP, rcv_fds + 5, 2, NULL); 302 build_rcv_fd(AF_INET6, SOCK_DCCP, rcv_fds + 7, 2, NULL); 303 test(rcv_fds, 9, AF_INET, SOCK_DCCP, rcv_fds[4]); 304 for (i = 0; i < 9; ++i) 305 close(rcv_fds[i]); 306 307 fprintf(stderr, "SUCCESS\n"); 308 return 0; 309 } 310