1 /* $NetBSD: shmtest.c,v 1.2 2001/02/19 22:44:41 cgd Exp $ */ 2 3 /*- 4 * Copyright (c) 1999 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * Test the SVID-compatible Shared Memory facility. 35 */ 36 37 #include <sys/param.h> 38 #include <sys/ipc.h> 39 #include <sys/mman.h> 40 #include <sys/shm.h> 41 #include <sys/wait.h> 42 43 #include <err.h> 44 #include <errno.h> 45 #include <signal.h> 46 #include <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <time.h> 50 #include <unistd.h> 51 52 int main(int, char *[]); 53 void print_shmid_ds(struct shmid_ds *, mode_t); 54 void sigsys_handler(int); 55 void sigchld_handler(int); 56 void cleanup(void); 57 void receiver(void); 58 59 const char *m_str = "The quick brown fox jumped over the lazy dog."; 60 61 int sender_shmid = -1; 62 pid_t child_pid; 63 64 key_t shmkey; 65 66 char keyname[] = "/tmp/msgtestXXXXXXXX"; 67 68 int verbose; 69 70 size_t pgsize; 71 72 int 73 main(argc, argv) 74 int argc; 75 char *argv[]; 76 { 77 struct sigaction sa; 78 struct shmid_ds s_ds; 79 sigset_t sigmask; 80 char *shm_buf; 81 int fd, ch; 82 83 if ((fd = mkstemp(keyname)) < 0) 84 err(1, "mkstemp"); 85 86 close(fd); 87 88 while ((ch = getopt(argc, argv, "v")) != -1) { 89 switch (ch) { 90 case 'v': 91 verbose = 1; 92 break; 93 default: 94 fprintf(stderr, "Usage: shmtest [-v]\n"); 95 exit(1); 96 } 97 } 98 99 /* 100 * Install a SIGSYS handler so that we can exit gracefully if 101 * System V Shared Memory support isn't in the kernel. 102 */ 103 sa.sa_handler = sigsys_handler; 104 sigemptyset(&sa.sa_mask); 105 sa.sa_flags = 0; 106 if (sigaction(SIGSYS, &sa, NULL) == -1) 107 err(1, "sigaction SIGSYS"); 108 109 /* 110 * Install and SIGCHLD handler to deal with all possible exit 111 * conditions of the receiver. 112 */ 113 sa.sa_handler = sigchld_handler; 114 sigemptyset(&sa.sa_mask); 115 sa.sa_flags = 0; 116 if (sigaction(SIGCHLD, &sa, NULL) == -1) 117 err(1, "sigaction SIGCHLD"); 118 119 pgsize = sysconf(_SC_PAGESIZE); 120 121 shmkey = ftok(argv[1], 4160); 122 123 /* 124 * Initialize child_pid to ourselves to that the cleanup function 125 * works before we create the receiver. 126 */ 127 child_pid = getpid(); 128 129 /* 130 * Make sure that when the sender exits, the message queue is 131 * removed. 132 */ 133 if (atexit(cleanup) == -1) 134 err(1, "atexit"); 135 136 if ((sender_shmid = shmget(shmkey, pgsize, IPC_CREAT | 0640)) == -1) 137 err(1, "shmget"); 138 139 if (shmctl(sender_shmid, IPC_STAT, &s_ds) == -1) 140 err(1, "shmctl IPC_STAT"); 141 142 if (verbose) 143 print_shmid_ds(&s_ds, 0640); 144 145 s_ds.shm_perm.mode = (s_ds.shm_perm.mode & ~0777) | 0600; 146 147 if (shmctl(sender_shmid, IPC_SET, &s_ds) == -1) 148 err(1, "shmctl IPC_SET"); 149 150 memset(&s_ds, 0, sizeof(s_ds)); 151 152 if (shmctl(sender_shmid, IPC_STAT, &s_ds) == -1) 153 err(1, "shmctl IPC_STAT"); 154 155 if ((s_ds.shm_perm.mode & 0777) != 0600) 156 err(1, "IPC_SET of mode didn't hold"); 157 158 if (verbose) 159 print_shmid_ds(&s_ds, 0600); 160 161 if ((shm_buf = shmat(sender_shmid, NULL, 0)) == (void *) -1) 162 err(1, "sender: shmat"); 163 164 /* 165 * Write the test pattern into the shared memory buffer. 166 */ 167 strlcpy(shm_buf, m_str, pgsize); 168 169 switch ((child_pid = fork())) { 170 case -1: 171 err(1, "fork"); 172 /* NOTREACHED */ 173 174 case 0: 175 receiver(); 176 break; 177 178 default: 179 break; 180 } 181 182 /* 183 * Suspend forever; when we get SIGCHLD, the handler will exit. 184 */ 185 sigemptyset(&sigmask); 186 (void) sigsuspend(&sigmask); 187 188 /* 189 * ...and any other signal is an unexpected error. 190 */ 191 errx(1, "sender: received unexpected signal"); 192 } 193 194 void 195 sigsys_handler(signo) 196 int signo; 197 { 198 199 errx(1, "System V Shared Memory support is not present in the kernel"); 200 } 201 202 void 203 sigchld_handler(signo) 204 int signo; 205 { 206 struct shmid_ds s_ds; 207 int cstatus; 208 209 /* 210 * Reap the child; if it exited successfully, then the test passed! 211 */ 212 if (waitpid(child_pid, &cstatus, 0) != child_pid) 213 err(1, "waitpid"); 214 215 if (WIFEXITED(cstatus) == 0) 216 errx(1, "receiver exited abnormally"); 217 218 if (WEXITSTATUS(cstatus) != 0) 219 errx(1, "receiver exited with status %d", 220 WEXITSTATUS(cstatus)); 221 222 /* 223 * If we get here, the child has exited normally, and thus 224 * we should exit normally too. First, tho, we print out 225 * the final stats for the message queue. 226 */ 227 228 if (shmctl(sender_shmid, IPC_STAT, &s_ds) == -1) 229 err(1, "shmctl IPC_STAT"); 230 231 if (verbose) 232 print_shmid_ds(&s_ds, 0600); 233 234 exit(0); 235 } 236 237 void 238 cleanup() 239 { 240 241 /* 242 * If we're the sender, and it exists, remove the shared memory area. 243 */ 244 if (child_pid != 0 && sender_shmid != -1) { 245 if (shmctl(sender_shmid, IPC_RMID, NULL) == -1) 246 warn("shmctl IPC_RMID"); 247 } 248 249 remove(keyname); 250 } 251 252 void 253 print_shmid_ds(sp, mode) 254 struct shmid_ds *sp; 255 mode_t mode; 256 { 257 uid_t uid = geteuid(); 258 gid_t gid = getegid(); 259 260 printf("PERM: uid %u, gid %u, cuid %u, cgid %u, mode 0%o\n", 261 sp->shm_perm.uid, sp->shm_perm.gid, 262 sp->shm_perm.cuid, sp->shm_perm.cgid, 263 sp->shm_perm.mode & 0777); 264 265 printf("segsz %lu, lpid %d, cpid %d, nattch %u\n", 266 (u_long)sp->shm_segsz, sp->shm_lpid, sp->shm_cpid, 267 sp->shm_nattch); 268 269 printf("atime: %s", ctime(&sp->shm_atime)); 270 printf("dtime: %s", ctime(&sp->shm_dtime)); 271 printf("ctime: %s", ctime(&sp->shm_ctime)); 272 273 /* 274 * Sanity check a few things. 275 */ 276 277 if (sp->shm_perm.uid != uid || sp->shm_perm.cuid != uid) 278 errx(1, "uid mismatch"); 279 280 if (sp->shm_perm.gid != gid || sp->shm_perm.cgid != gid) 281 errx(1, "gid mismatch"); 282 283 if ((sp->shm_perm.mode & 0777) != mode) 284 errx(1, "mode mismatch"); 285 } 286 287 void 288 receiver() 289 { 290 int shmid; 291 void *shm_buf; 292 void *block; 293 294 if ((shmid = shmget(shmkey, pgsize, 0)) == -1) 295 err(1, "receiver: shmget"); 296 297 if ((shm_buf = shmat(shmid, NULL, 0)) == (void *) -1) 298 err(1, "receiver: shmat"); 299 300 if (verbose) 301 printf("%.*s\n", (int)pgsize, (const char *)shm_buf); 302 if (strcmp((const char *)shm_buf, m_str) != 0) 303 errx(1, "receiver: data isn't correct"); 304 305 /* mmap() a page to get a distinct, freeable address */ 306 block = mmap(NULL, pgsize, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, 307 -1, 0); 308 if (block == MAP_FAILED) 309 err(1, "receiver: mmap"); 310 311 /* detach, then try to attach, conflicting with the mmap() */ 312 if (shmdt(shm_buf) == -1) 313 err(1, "receiver: shmdt"); 314 if ((shm_buf = shmat(shmid, block, 0)) != (void *) -1) 315 errx(1, "receiver: shmat(conflict) succeeded!"); 316 if (errno != ENOMEM) 317 err(1, "receiver: shmat(conflict) wrong error"); 318 319 /* free up that address and try again */ 320 if (munmap(block, pgsize) == -1) 321 err(1, "receiver: munmap"); 322 if ((shm_buf = shmat(shmid, block, 0)) == (void *) -1) 323 err(1, "receiver: shmat(fixed)"); 324 325 if (shm_buf != block) 326 errx(1, "receiver: shmat not at expected address: %p != %p", 327 shm_buf, block); 328 329 if (verbose) 330 printf("%.*s\n", (int)pgsize, (const char *)shm_buf); 331 if (strcmp((const char *)shm_buf, m_str) != 0) 332 errx(1, "receiver: data isn't correct second time"); 333 334 exit(0); 335 } 336