/* $NetBSD: shmtest.c,v 1.2 2001/02/19 22:44:41 cgd Exp $ */ /*- * Copyright (c) 1999 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, * NASA Ames Research Center. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * Test the SVID-compatible Shared Memory facility. */ #include #include #include #include #include #include #include #include #include #include #include #include int main(int, char *[]); void print_shmid_ds(struct shmid_ds *, mode_t); void sigsys_handler(int); void sigchld_handler(int); void cleanup(void); void receiver(void); const char *m_str = "The quick brown fox jumped over the lazy dog."; int sender_shmid = -1; pid_t child_pid; key_t shmkey; char keyname[] = "/tmp/msgtestXXXXXXXX"; int verbose; size_t pgsize; int main(argc, argv) int argc; char *argv[]; { struct sigaction sa; struct shmid_ds s_ds; sigset_t sigmask; char *shm_buf; int fd, ch; if ((fd = mkstemp(keyname)) < 0) err(1, "mkstemp"); close(fd); while ((ch = getopt(argc, argv, "v")) != -1) { switch (ch) { case 'v': verbose = 1; break; default: fprintf(stderr, "Usage: shmtest [-v]\n"); exit(1); } } /* * Install a SIGSYS handler so that we can exit gracefully if * System V Shared Memory support isn't in the kernel. */ sa.sa_handler = sigsys_handler; sigemptyset(&sa.sa_mask); sa.sa_flags = 0; if (sigaction(SIGSYS, &sa, NULL) == -1) err(1, "sigaction SIGSYS"); /* * Install and SIGCHLD handler to deal with all possible exit * conditions of the receiver. */ sa.sa_handler = sigchld_handler; sigemptyset(&sa.sa_mask); sa.sa_flags = 0; if (sigaction(SIGCHLD, &sa, NULL) == -1) err(1, "sigaction SIGCHLD"); pgsize = sysconf(_SC_PAGESIZE); shmkey = ftok(argv[1], 4160); /* * Initialize child_pid to ourselves to that the cleanup function * works before we create the receiver. */ child_pid = getpid(); /* * Make sure that when the sender exits, the message queue is * removed. */ if (atexit(cleanup) == -1) err(1, "atexit"); if ((sender_shmid = shmget(shmkey, pgsize, IPC_CREAT | 0640)) == -1) err(1, "shmget"); if (shmctl(sender_shmid, IPC_STAT, &s_ds) == -1) err(1, "shmctl IPC_STAT"); if (verbose) print_shmid_ds(&s_ds, 0640); s_ds.shm_perm.mode = (s_ds.shm_perm.mode & ~0777) | 0600; if (shmctl(sender_shmid, IPC_SET, &s_ds) == -1) err(1, "shmctl IPC_SET"); memset(&s_ds, 0, sizeof(s_ds)); if (shmctl(sender_shmid, IPC_STAT, &s_ds) == -1) err(1, "shmctl IPC_STAT"); if ((s_ds.shm_perm.mode & 0777) != 0600) err(1, "IPC_SET of mode didn't hold"); if (verbose) print_shmid_ds(&s_ds, 0600); if ((shm_buf = shmat(sender_shmid, NULL, 0)) == (void *) -1) err(1, "sender: shmat"); /* * Write the test pattern into the shared memory buffer. */ strlcpy(shm_buf, m_str, pgsize); switch ((child_pid = fork())) { case -1: err(1, "fork"); /* NOTREACHED */ case 0: receiver(); break; default: break; } /* * Suspend forever; when we get SIGCHLD, the handler will exit. */ sigemptyset(&sigmask); (void) sigsuspend(&sigmask); /* * ...and any other signal is an unexpected error. */ errx(1, "sender: received unexpected signal"); } void sigsys_handler(signo) int signo; { errx(1, "System V Shared Memory support is not present in the kernel"); } void sigchld_handler(signo) int signo; { struct shmid_ds s_ds; int cstatus; /* * Reap the child; if it exited successfully, then the test passed! */ if (waitpid(child_pid, &cstatus, 0) != child_pid) err(1, "waitpid"); if (WIFEXITED(cstatus) == 0) errx(1, "receiver exited abnormally"); if (WEXITSTATUS(cstatus) != 0) errx(1, "receiver exited with status %d", WEXITSTATUS(cstatus)); /* * If we get here, the child has exited normally, and thus * we should exit normally too. First, tho, we print out * the final stats for the message queue. */ if (shmctl(sender_shmid, IPC_STAT, &s_ds) == -1) err(1, "shmctl IPC_STAT"); if (verbose) print_shmid_ds(&s_ds, 0600); exit(0); } void cleanup() { /* * If we're the sender, and it exists, remove the shared memory area. */ if (child_pid != 0 && sender_shmid != -1) { if (shmctl(sender_shmid, IPC_RMID, NULL) == -1) warn("shmctl IPC_RMID"); } remove(keyname); } void print_shmid_ds(sp, mode) struct shmid_ds *sp; mode_t mode; { uid_t uid = geteuid(); gid_t gid = getegid(); printf("PERM: uid %u, gid %u, cuid %u, cgid %u, mode 0%o\n", sp->shm_perm.uid, sp->shm_perm.gid, sp->shm_perm.cuid, sp->shm_perm.cgid, sp->shm_perm.mode & 0777); printf("segsz %lu, lpid %d, cpid %d, nattch %u\n", (u_long)sp->shm_segsz, sp->shm_lpid, sp->shm_cpid, sp->shm_nattch); printf("atime: %s", ctime(&sp->shm_atime)); printf("dtime: %s", ctime(&sp->shm_dtime)); printf("ctime: %s", ctime(&sp->shm_ctime)); /* * Sanity check a few things. */ if (sp->shm_perm.uid != uid || sp->shm_perm.cuid != uid) errx(1, "uid mismatch"); if (sp->shm_perm.gid != gid || sp->shm_perm.cgid != gid) errx(1, "gid mismatch"); if ((sp->shm_perm.mode & 0777) != mode) errx(1, "mode mismatch"); } void receiver() { int shmid; void *shm_buf; void *block; if ((shmid = shmget(shmkey, pgsize, 0)) == -1) err(1, "receiver: shmget"); if ((shm_buf = shmat(shmid, NULL, 0)) == (void *) -1) err(1, "receiver: shmat"); if (verbose) printf("%.*s\n", (int)pgsize, (const char *)shm_buf); if (strcmp((const char *)shm_buf, m_str) != 0) errx(1, "receiver: data isn't correct"); /* mmap() a page to get a distinct, freeable address */ block = mmap(NULL, pgsize, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0); if (block == MAP_FAILED) err(1, "receiver: mmap"); /* detach, then try to attach, conflicting with the mmap() */ if (shmdt(shm_buf) == -1) err(1, "receiver: shmdt"); if ((shm_buf = shmat(shmid, block, 0)) != (void *) -1) errx(1, "receiver: shmat(conflict) succeeded!"); if (errno != ENOMEM) err(1, "receiver: shmat(conflict) wrong error"); /* free up that address and try again */ if (munmap(block, pgsize) == -1) err(1, "receiver: munmap"); if ((shm_buf = shmat(shmid, block, 0)) == (void *) -1) err(1, "receiver: shmat(fixed)"); if (shm_buf != block) errx(1, "receiver: shmat not at expected address: %p != %p", shm_buf, block); if (verbose) printf("%.*s\n", (int)pgsize, (const char *)shm_buf); if (strcmp((const char *)shm_buf, m_str) != 0) errx(1, "receiver: data isn't correct second time"); exit(0); }