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