1/*
2 * Copyright (c) 1980, 1993
3 *	The Regents of the University of California.  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 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35#if 0
36static char sccsid[] = "@(#)popen.c	8.1 (Berkeley) 6/6/93";
37#endif
38static const char rcsid[] =
39  "$FreeBSD: src/usr.bin/mail/popen.c,v 1.7 2002/06/30 05:25:06 obrien Exp $";
40#endif /* not lint */
41#include <sys/cdefs.h>
42
43
44#include "rcv.h"
45#include <sys/wait.h>
46#include <fcntl.h>
47#include "extern.h"
48
49#define READ 0
50#define WRITE 1
51
52struct fp {
53	FILE	*fp;
54	int	pipe;
55	int	pid;
56	struct	fp *link;
57};
58static struct fp *fp_head;
59
60struct child {
61	int	pid;
62	char	done;
63	char	free;
64	int	status;
65	struct	child *link;
66};
67static struct child *child;
68static struct child *findchild(int);
69static void delchild(struct child *);
70static int file_pid(FILE *);
71
72FILE *
73Fopen(path, mode)
74	const char *path, *mode;
75{
76	FILE *fp;
77
78	if ((fp = fopen(path, mode)) != NULL) {
79		register_file(fp, 0, 0);
80		(void)fcntl(fileno(fp), F_SETFD, 1);
81	}
82	return (fp);
83}
84
85FILE *
86Fdopen(fd, mode)
87	int fd;
88	const char *mode;
89{
90	FILE *fp;
91
92	if ((fp = fdopen(fd, mode)) != NULL) {
93		register_file(fp, 0, 0);
94		(void)fcntl(fileno(fp), F_SETFD, 1);
95	}
96	return (fp);
97}
98
99int
100Fclose(fp)
101	FILE *fp;
102{
103	unregister_file(fp);
104	return (fclose(fp));
105}
106
107FILE *
108Popen(cmd, mode)
109	char *cmd;
110	const char *mode;
111{
112	int p[2];
113	int myside, hisside, fd0, fd1;
114	int pid;
115	sigset_t nset;
116	FILE *fp;
117
118	if (pipe(p) < 0)
119		return (NULL);
120	(void)fcntl(p[READ], F_SETFD, 1);
121	(void)fcntl(p[WRITE], F_SETFD, 1);
122	if (*mode == 'r') {
123		myside = p[READ];
124		fd0 = -1;
125		hisside = fd1 = p[WRITE];
126	} else {
127		myside = p[WRITE];
128		hisside = fd0 = p[READ];
129		fd1 = -1;
130	}
131	(void)sigemptyset(&nset);
132	if ((pid = start_command(cmd, &nset, fd0, fd1, NULL, NULL, NULL)) < 0) {
133		(void)close(p[READ]);
134		(void)close(p[WRITE]);
135		return (NULL);
136	}
137	(void)close(hisside);
138	if ((fp = fdopen(myside, mode)) != NULL)
139		register_file(fp, 1, pid);
140	return (fp);
141}
142
143int
144Pclose(ptr)
145	FILE *ptr;
146{
147	int i;
148	sigset_t nset, oset;
149
150	i = file_pid(ptr);
151	unregister_file(ptr);
152	(void)fclose(ptr);
153	(void)sigemptyset(&nset);
154	(void)sigaddset(&nset, SIGINT);
155	(void)sigaddset(&nset, SIGHUP);
156	(void)sigprocmask(SIG_BLOCK, &nset, &oset);
157	i = wait_child(i);
158	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
159	return (i);
160}
161
162void
163close_all_files()
164{
165
166	while (fp_head != NULL)
167		if (fp_head->pipe)
168			(void)Pclose(fp_head->fp);
169		else
170			(void)Fclose(fp_head->fp);
171}
172
173void
174register_file(fp, pipe, pid)
175	FILE *fp;
176	int pipe, pid;
177{
178	struct fp *fpp;
179
180	if ((fpp = malloc(sizeof(*fpp))) == NULL)
181		err(1, "Out of memory");
182	fpp->fp = fp;
183	fpp->pipe = pipe;
184	fpp->pid = pid;
185	fpp->link = fp_head;
186	fp_head = fpp;
187}
188
189void
190unregister_file(fp)
191	FILE *fp;
192{
193	struct fp **pp, *p;
194
195	for (pp = &fp_head; (p = *pp) != NULL; pp = &p->link)
196		if (p->fp == fp) {
197			*pp = p->link;
198			(void)free(p);
199			return;
200		}
201	errx(1, "Invalid file pointer");
202	/*NOTREACHED*/
203}
204
205int
206file_pid(fp)
207	FILE *fp;
208{
209	struct fp *p;
210
211	for (p = fp_head; p != NULL; p = p->link)
212		if (p->fp == fp)
213			return (p->pid);
214	errx(1, "Invalid file pointer");
215	/*NOTREACHED*/
216}
217
218/*
219 * Run a command without a shell, with optional arguments and splicing
220 * of stdin and stdout.  The command name can be a sequence of words.
221 * Signals must be handled by the caller.
222 * "Mask" contains the signals to ignore in the new process.
223 * SIGINT is enabled unless it's in the mask.
224 */
225/*VARARGS4*/
226int
227run_command(cmd, mask, infd, outfd, a0, a1, a2)
228	char *cmd;
229	sigset_t *mask;
230	int infd, outfd;
231	char *a0, *a1, *a2;
232{
233	int pid;
234
235	if ((pid = start_command(cmd, mask, infd, outfd, a0, a1, a2)) < 0)
236		return (-1);
237	return (wait_command(pid));
238}
239
240/*VARARGS4*/
241int
242start_command(cmd, mask, infd, outfd, a0, a1, a2)
243	char *cmd;
244	sigset_t *mask;
245	int infd, outfd;
246	char *a0, *a1, *a2;
247{
248	int pid;
249
250	if ((pid = fork()) < 0) {
251		warn("fork");
252		return (-1);
253	}
254	if (pid == 0) {
255		char *argv[100];
256		int i = getrawlist(cmd, argv, sizeof(argv) / sizeof(*argv));
257
258		if ((argv[i++] = a0) != NULL &&
259		    (argv[i++] = a1) != NULL &&
260		    (argv[i++] = a2) != NULL)
261			argv[i] = NULL;
262		prepare_child(mask, infd, outfd);
263		execvp(argv[0], argv);
264		warn("%s", argv[0]);
265		_exit(1);
266	}
267	return (pid);
268}
269
270void
271prepare_child(nset, infd, outfd)
272	sigset_t *nset;
273	int infd, outfd;
274{
275	int i;
276	sigset_t eset;
277
278	/*
279	 * All file descriptors other than 0, 1, and 2 are supposed to be
280	 * close-on-exec.
281	 */
282	if (infd >= 0)
283		dup2(infd, 0);
284	if (outfd >= 0)
285		dup2(outfd, 1);
286	for (i = 1; i < NSIG; i++)
287		if (nset != NULL && sigismember(nset, i))
288			(void)signal(i, SIG_IGN);
289	if (nset == NULL || !sigismember(nset, SIGINT))
290		(void)signal(SIGINT, SIG_DFL);
291	(void)sigemptyset(&eset);
292	(void)sigprocmask(SIG_SETMASK, &eset, NULL);
293}
294
295int
296wait_command(pid)
297	int pid;
298{
299
300	if (wait_child(pid) < 0) {
301		printf("Fatal error in process.\n");
302		return (-1);
303	}
304	return (0);
305}
306
307static struct child *
308findchild(pid)
309	int pid;
310{
311	struct child **cpp;
312
313	for (cpp = &child; *cpp != NULL && (*cpp)->pid != pid;
314	    cpp = &(*cpp)->link)
315			;
316	if (*cpp == NULL) {
317		*cpp = malloc(sizeof(struct child));
318		if (*cpp == NULL)
319			err(1, "Out of memory");
320		(*cpp)->pid = pid;
321		(*cpp)->done = (*cpp)->free = 0;
322		(*cpp)->link = NULL;
323	}
324	return (*cpp);
325}
326
327static void
328delchild(cp)
329	struct child *cp;
330{
331	struct child **cpp;
332
333	for (cpp = &child; *cpp != cp; cpp = &(*cpp)->link)
334		;
335	*cpp = cp->link;
336	(void)free(cp);
337}
338
339/*ARGSUSED*/
340void
341sigchild(signo)
342	int signo;
343{
344	int pid;
345	int status;
346	struct child *cp;
347
348	while ((pid = waitpid((pid_t)-1, &status, WNOHANG)) > 0) {
349		cp = findchild(pid);
350		if (cp->free)
351			delchild(cp);
352		else {
353			cp->done = 1;
354			cp->status = status;
355		}
356	}
357}
358
359int wait_status;
360
361/*
362 * Wait for a specific child to die.
363 */
364int
365wait_child(pid)
366	int pid;
367{
368	sigset_t nset, oset;
369	struct child *cp = findchild(pid);
370
371	(void)sigemptyset(&nset);
372	(void)sigaddset(&nset, SIGCHLD);
373	(void)sigprocmask(SIG_BLOCK, &nset, &oset);
374
375	while (!cp->done)
376		(void)sigsuspend(&oset);
377	wait_status = cp->status;
378	delchild(cp);
379	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
380	return ((WIFEXITED(wait_status) && WEXITSTATUS(wait_status)) ? -1 : 0);
381}
382
383/*
384 * Mark a child as don't care.
385 */
386void
387free_child(pid)
388	int pid;
389{
390	sigset_t nset, oset;
391	struct child *cp = findchild(pid);
392
393	(void)sigemptyset(&nset);
394	(void)sigaddset(&nset, SIGCHLD);
395	(void)sigprocmask(SIG_BLOCK, &nset, &oset);
396
397	if (cp->done)
398		delchild(cp);
399	else
400		cp->free = 1;
401	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
402}
403