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