1 /*- 2 * Copyright (c) 2010 Mikolaj Golub 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 /* 30 * This regression test attempts to trigger a race that occurs when both 31 * endpoints of a connected UNIX domain socket are closed at once. The two 32 * close paths may run concurrently leading to a call to sodisconnect() on an 33 * already-closed socket in kernel. Before it was fixed, this might lead to 34 * ENOTCONN being returned improperly from close(). 35 * 36 * This race is fairly timing-dependent, so it effectively requires SMP, and 37 * may not even trigger then. 38 */ 39 40 #include <sys/types.h> 41 #include <sys/select.h> 42 #include <sys/socket.h> 43 #include <sys/sysctl.h> 44 #include <sys/un.h> 45 #include <netinet/in.h> 46 #include <arpa/inet.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <signal.h> 50 #include <stdlib.h> 51 #include <stdio.h> 52 #include <strings.h> 53 #include <string.h> 54 #include <unistd.h> 55 #include <err.h> 56 57 static char socket_path[] = "tmp.XXXXXXXX"; 58 59 #define USLEEP 100 60 #define LOOPS 100000 61 62 int 63 main(void) 64 { 65 struct sockaddr_un servaddr; 66 int listenfd, connfd, pid; 67 u_int counter, ncpus; 68 size_t len; 69 70 len = sizeof(ncpus); 71 if (sysctlbyname("kern.smp.cpus", &ncpus, &len, NULL, 0) < 0) 72 err(1, "kern.smp.cpus"); 73 if (len != sizeof(ncpus)) 74 errx(1, "kern.smp.cpus: invalid length"); 75 if (ncpus < 2) 76 warnx("SMP not present, test may be unable to trigger race"); 77 78 if (mkstemp(socket_path) == -1) 79 err(1, "mkstemp failed"); 80 unlink(socket_path); 81 82 /* 83 * Create a UNIX domain socket that the child will repeatedly 84 * accept() from, and that the parent will repeatedly connect() to. 85 */ 86 if ((listenfd = socket(AF_LOCAL, SOCK_STREAM, 0)) < 0) 87 err(1, "parent: socket error"); 88 (void)unlink(socket_path); 89 bzero(&servaddr, sizeof(servaddr)); 90 servaddr.sun_family = AF_LOCAL; 91 strcpy(servaddr.sun_path, socket_path); 92 if (bind(listenfd, (struct sockaddr *) &servaddr, 93 sizeof(servaddr)) < 0) 94 err(1, "parent: bind error"); 95 if (listen(listenfd, 1024) < 0) 96 err(1, "parent: listen error"); 97 98 pid = fork(); 99 if (pid == -1) 100 err(1, "fork()"); 101 if (pid != 0) { 102 /* 103 * In the parent, repeatedly connect and disconnect from the 104 * socket, attempting to induce the race. 105 */ 106 close(listenfd); 107 sleep(1); 108 bzero(&servaddr, sizeof(servaddr)); 109 servaddr.sun_family = AF_LOCAL; 110 strcpy(servaddr.sun_path, socket_path); 111 for (counter = 0; counter < LOOPS; counter++) { 112 if ((connfd = socket(AF_LOCAL, SOCK_STREAM, 0)) < 0) { 113 (void)kill(pid, SIGTERM); 114 err(1, "parent: socket error"); 115 } 116 if (connect(connfd, (struct sockaddr *)&servaddr, 117 sizeof(servaddr)) < 0) { 118 (void)kill(pid, SIGTERM); 119 err(1, "parent: connect error"); 120 } 121 if (close(connfd) < 0) { 122 (void)kill(pid, SIGTERM); 123 err(1, "parent: close error"); 124 } 125 usleep(USLEEP); 126 } 127 (void)kill(pid, SIGTERM); 128 } else { 129 /* 130 * In the child, loop accepting and closing. We may pick up 131 * the race here so report errors from close(). 132 */ 133 for ( ; ; ) { 134 if ((connfd = accept(listenfd, 135 (struct sockaddr *)NULL, NULL)) < 0) 136 err(1, "child: accept error"); 137 if (close(connfd) < 0) 138 err(1, "child: close error"); 139 } 140 } 141 printf("OK\n"); 142 exit(0); 143 } 144