279 lines · c
1// SPDX-License-Identifier: GPL-2.02 3/* Test that sockets listening on a specific address are preferred4 * over sockets listening on addr_any.5 */6 7#define _GNU_SOURCE8 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_DCCP25#define SOL_DCCP 26926#endif27 28static const char *IP4_ADDR = "127.0.0.1";29static const char *IP6_ADDR = "::1";30static const char *IP4_MAPPED6 = "::ffff:127.0.0.1";31 32static const int PORT = 8888;33 34static 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 terminating68 * the program, so it complains that saddr, sz are69 * 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 101static 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 terminating141 * the program, so it complains that saddr, daddr, sz are142 * 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 168static 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 194static 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 221static 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 address225 * is always selected in preference over a socket listening226 * on addr_any. Bugs where this is not the case often result227 * in sockets created first or last to get picked. So below228 * we make sure that there are always addr_any sockets created229 * 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 244static 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 } else255 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 270int 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