/* $OpenBSD: popen.c,v 1.18 1998/06/12 18:07:58 millert Exp $ */ /* $NetBSD: popen.c,v 1.6 1997/05/13 06:48:42 mikel Exp $ */ /* * Copyright (c) 1980, 1993 * The Regents of the University of California. All rights reserved. * * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. */ #ifndef lint #if 0 static char sccsid[] = "@(#)popen.c 8.1 (Berkeley) 6/6/93"; #else static char rcsid[] = "$OpenBSD: popen.c,v 1.18 1998/06/12 18:07:58 millert Exp $"; #endif #endif /* not lint */ #include "rcv.h" #include #include #include #include "extern.h" #define READ 0 #define WRITE 1 struct fp { FILE *fp; int pipe; int pid; struct fp *link; }; static struct fp *fp_head; struct child { int pid; char done; char free; int status; struct child *link; }; static struct child *child, *child_freelist = NULL; static struct child *findchild __P((int, int)); static void delchild __P((struct child *)); static int file_pid __P((FILE *)); static int handle_spool_locks __P((int)); FILE * Fopen(file, mode) char *file, *mode; { FILE *fp; if ((fp = fopen(file, mode)) != NULL) { register_file(fp, 0, 0); (void)fcntl(fileno(fp), F_SETFD, 1); } return(fp); } FILE * Fdopen(fd, mode) int fd; char *mode; { FILE *fp; if ((fp = fdopen(fd, mode)) != NULL) { register_file(fp, 0, 0); (void)fcntl(fileno(fp), F_SETFD, 1); } return(fp); } int Fclose(fp) FILE *fp; { unregister_file(fp); return(fclose(fp)); } FILE * Popen(cmd, mode) char *cmd; char *mode; { int p[2]; int myside, hisside, fd0, fd1; int pid; sigset_t nset; FILE *fp; if (pipe(p) < 0) return(NULL); (void)fcntl(p[READ], F_SETFD, 1); (void)fcntl(p[WRITE], F_SETFD, 1); if (*mode == 'r') { myside = p[READ]; fd0 = -1; hisside = fd1 = p[WRITE]; } else { myside = p[WRITE]; hisside = fd0 = p[READ]; fd1 = -1; } sigemptyset(&nset); if ((pid = start_command(cmd, &nset, fd0, fd1, NULL, NULL, NULL)) < 0) { (void)close(p[READ]); (void)close(p[WRITE]); return(NULL); } (void)close(hisside); if ((fp = fdopen(myside, mode)) != NULL) register_file(fp, 1, pid); return(fp); } int Pclose(ptr) FILE *ptr; { int i; sigset_t nset, oset; i = file_pid(ptr); unregister_file(ptr); (void)fclose(ptr); sigemptyset(&nset); sigaddset(&nset, SIGINT); sigaddset(&nset, SIGHUP); sigprocmask(SIG_BLOCK, &nset, &oset); i = wait_child(i); sigprocmask(SIG_SETMASK, &oset, NULL); return(i); } void close_all_files() { while (fp_head) if (fp_head->pipe) (void)Pclose(fp_head->fp); else (void)Fclose(fp_head->fp); } void register_file(fp, pipe, pid) FILE *fp; int pipe, pid; { struct fp *fpp; if ((fpp = (struct fp *)malloc(sizeof(*fpp))) == NULL) errx(1, "Out of memory"); fpp->fp = fp; fpp->pipe = pipe; fpp->pid = pid; fpp->link = fp_head; fp_head = fpp; } void unregister_file(fp) FILE *fp; { struct fp **pp, *p; for (pp = &fp_head; (p = *pp) != NULL; pp = &p->link) if (p->fp == fp) { *pp = p->link; (void)free(p); return; } errx(1, "Invalid file pointer"); } static int file_pid(fp) FILE *fp; { struct fp *p; for (p = fp_head; p; p = p->link) if (p->fp == fp) return(p->pid); errx(1, "Invalid file pointer"); /*NOTREACHED*/ } /* * Run a command without a shell, with optional arguments and splicing * of stdin and stdout. The command name can be a sequence of words. * Signals must be handled by the caller. * "Mask" contains the signals to ignore in the new process. * SIGINT is enabled unless it's in the mask. */ /*VARARGS4*/ int run_command(cmd, nset, infd, outfd, a0, a1, a2) char *cmd; sigset_t *nset; int infd, outfd; char *a0, *a1, *a2; { int pid; if ((pid = start_command(cmd, nset, infd, outfd, a0, a1, a2)) < 0) return(-1); return(wait_command(pid)); } /*VARARGS4*/ int start_command(cmd, nset, infd, outfd, a0, a1, a2) char *cmd; sigset_t *nset; int infd, outfd; char *a0, *a1, *a2; { int pid; if ((pid = vfork()) < 0) { warn("fork"); return(-1); } if (pid == 0) { char *argv[100]; int i = getrawlist(cmd, argv, sizeof(argv)/ sizeof(*argv)); if ((argv[i++] = a0) != NULL && (argv[i++] = a1) != NULL && (argv[i++] = a2) != NULL) argv[i] = NULL; prepare_child(nset, infd, outfd); execvp(argv[0], argv); warn(argv[0]); _exit(1); } return(pid); } void prepare_child(nset, infd, outfd) sigset_t *nset; int infd, outfd; { int i; sigset_t eset; /* * All file descriptors other than 0, 1, and 2 are supposed to be * close-on-exec. */ if (infd >= 0) dup2(infd, 0); if (outfd >= 0) dup2(outfd, 1); if (nset == NULL) return; if (nset != NULL) { for (i = 1; i < NSIG; i++) if (sigismember(nset, i)) (void)signal(i, SIG_IGN); } if (nset == NULL || !sigismember(nset, SIGINT)) (void)signal(SIGINT, SIG_DFL); sigemptyset(&eset); (void)sigprocmask(SIG_SETMASK, &eset, NULL); } int wait_command(pid) int pid; { if (wait_child(pid) < 0) { puts("Fatal error in process."); return(-1); } return(0); } static struct child * findchild(pid, dont_alloc) int pid; int dont_alloc; { struct child **cpp; for (cpp = &child; *cpp != NULL && (*cpp)->pid != pid; cpp = &(*cpp)->link) ; if (*cpp == NULL) { if (dont_alloc) return(NULL); if (child_freelist) { *cpp = child_freelist; child_freelist = (*cpp)->link; } else *cpp = (struct child *)malloc(sizeof(struct child)); (*cpp)->pid = pid; (*cpp)->done = (*cpp)->free = 0; (*cpp)->link = NULL; } return(*cpp); } static void delchild(cp) struct child *cp; { struct child **cpp; for (cpp = &child; *cpp != cp; cpp = &(*cpp)->link) ; *cpp = cp->link; cp->link = child_freelist; child_freelist = cp; } void sigchild(signo) int signo; { int pid; int status; struct child *cp; int save_errno = errno; while ((pid = waitpid((pid_t)-1, &status, WNOHANG)) > 0) { cp = findchild(pid, 1); if (!cp) continue; if (cp->free) delchild(cp); else { cp->done = 1; cp->status = status; } } errno = save_errno; } int wait_status; /* * Wait for a specific child to die. */ int wait_child(pid) int pid; { struct child *cp = findchild(pid, 0); sigset_t nset, oset; if (cp == NULL) return(-1); sigemptyset(&nset); sigaddset(&nset, SIGCHLD); sigprocmask(SIG_BLOCK, &nset, &oset); while (!cp->done) sigsuspend(&oset); wait_status = cp->status; delchild(cp); sigprocmask(SIG_SETMASK, &oset, NULL); return((WIFEXITED(wait_status) && WEXITSTATUS(wait_status)) ? -1 : 0); } /* * Mark a child as don't care. */ void free_child(pid) int pid; { struct child *cp = findchild(pid, 0); sigset_t nset, oset; if (cp == NULL) return; sigemptyset(&nset); sigaddset(&nset, SIGCHLD); sigprocmask(SIG_BLOCK, &nset, &oset); if (cp->done) delchild(cp); else cp->free = 1; sigprocmask(SIG_SETMASK, &oset, NULL); } /* * Lock(1)/unlock(0) mail spool using mail.local's -H flag. * Returns 1 for success, 0 for failure, -1 for bad usage. */ static int handle_spool_locks(action) int action; { char *cmd; static FILE *lockfp = NULL; static int lock_pid; if (action == 0) { /* Clear the lock */ if (lockfp == NULL) { fputs("handle_spool_locks: no spool lock to remove.\n", stderr); return(-1); } (void)kill(lock_pid, SIGTERM); (void)Pclose(lockfp); lockfp = NULL; } else if (action == 1) { /* Create the lock */ if ((cmd = (char *)malloc(sizeof(_PATH_MAIL_LOCAL) + 3)) == NULL) errx(1, "Out of memory"); sprintf(cmd, "%s -H", _PATH_MAIL_LOCAL); if ((lockfp = Popen(cmd, "r")) == NULL || getc(lockfp) != '1') { lockfp = NULL; (void)free(cmd); return(0); } lock_pid = fp_head->pid; /* new entries added at head */ (void)free(cmd); } else { fprintf(stderr, "handle_spool_locks: unknown action %d\n", action); return(-1); } return(1); } int spool_lock() { return(handle_spool_locks(1)); } int spool_unlock() { return(handle_spool_locks(0)); }