freebsd-src/usr.bin/mail/popen.c
Bruce Evans db6b691087 vfork -> fork. This home made popen() had the same bug as the library
popen(), but worse.  The child calls execvp(), which calls malloc()
a bit more than execl(), and it calls non-library functions that call
malloc() and who-knows-what else (stdio is called in at least some
error cases).
1998-10-10 19:18:30 +00:00

374 lines
7.2 KiB
C

/*
* 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
static char sccsid[] = "@(#)popen.c 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
#include "rcv.h"
#include <sys/wait.h>
#include <fcntl.h>
#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;
union wait status;
struct child *link;
};
static struct child *child;
static struct child *findchild __P((int));
static void delchild __P((struct child *));
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;
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;
}
if ((pid = start_command(cmd, 0, fd0, fd1, NOSTR, NOSTR, NOSTR)) < 0) {
close(p[READ]);
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;
int omask;
i = file_pid(ptr);
unregister_file(ptr);
(void) fclose(ptr);
omask = sigblock(sigmask(SIGINT)|sigmask(SIGHUP));
i = wait_child(i);
sigsetmask(omask);
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)
panic("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; pp = &p->link)
if (p->fp == fp) {
*pp = p->link;
free((char *) p);
return;
}
panic("Invalid file pointer");
}
file_pid(fp)
FILE *fp;
{
struct fp *p;
for (p = fp_head; p; p = p->link)
if (p->fp == fp)
return (p->pid);
panic("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, mask, infd, outfd, a0, a1, a2)
char *cmd;
int mask, infd, outfd;
char *a0, *a1, *a2;
{
int pid;
if ((pid = start_command(cmd, mask, infd, outfd, a0, a1, a2)) < 0)
return -1;
return wait_command(pid);
}
/*VARARGS4*/
int
start_command(cmd, mask, infd, outfd, a0, a1, a2)
char *cmd;
int mask, infd, outfd;
char *a0, *a1, *a2;
{
int pid;
if ((pid = fork()) < 0) {
perror("fork");
return -1;
}
if (pid == 0) {
char *argv[100];
int i = getrawlist(cmd, argv, sizeof argv / sizeof *argv);
if ((argv[i++] = a0) != NOSTR &&
(argv[i++] = a1) != NOSTR &&
(argv[i++] = a2) != NOSTR)
argv[i] = NOSTR;
prepare_child(mask, infd, outfd);
execvp(argv[0], argv);
perror(argv[0]);
_exit(1);
}
return pid;
}
void
prepare_child(mask, infd, outfd)
int mask, infd, outfd;
{
int i;
/*
* 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);
for (i = 1; i <= NSIG; i++)
if (mask & sigmask(i))
(void) signal(i, SIG_IGN);
if ((mask & sigmask(SIGINT)) == 0)
(void) signal(SIGINT, SIG_DFL);
(void) sigsetmask(0);
}
int
wait_command(pid)
int pid;
{
if (wait_child(pid) < 0) {
printf("Fatal error in process.\n");
return -1;
}
return 0;
}
static struct child *
findchild(pid)
int pid;
{
register struct child **cpp;
for (cpp = &child; *cpp != NULL && (*cpp)->pid != pid;
cpp = &(*cpp)->link)
;
if (*cpp == NULL) {
*cpp = (struct child *) malloc(sizeof (struct child));
(*cpp)->pid = pid;
(*cpp)->done = (*cpp)->free = 0;
(*cpp)->link = NULL;
}
return *cpp;
}
static void
delchild(cp)
register struct child *cp;
{
register struct child **cpp;
for (cpp = &child; *cpp != cp; cpp = &(*cpp)->link)
;
*cpp = cp->link;
free((char *) cp);
}
void
sigchild(signo)
int signo;
{
int pid;
union wait status;
register struct child *cp;
while ((pid =
wait3((int *)&status, WNOHANG, (struct rusage *)0)) > 0) {
cp = findchild(pid);
if (cp->free)
delchild(cp);
else {
cp->done = 1;
cp->status = status;
}
}
}
union wait wait_status;
/*
* Wait for a specific child to die.
*/
int
wait_child(pid)
int pid;
{
int mask = sigblock(sigmask(SIGCHLD));
register struct child *cp = findchild(pid);
while (!cp->done)
sigpause(mask);
wait_status = cp->status;
delchild(cp);
sigsetmask(mask);
return wait_status.w_status ? -1 : 0;
}
/*
* Mark a child as don't care.
*/
void
free_child(pid)
int pid;
{
int mask = sigblock(sigmask(SIGCHLD));
register struct child *cp = findchild(pid);
if (cp->done)
delchild(cp);
else
cp->free = 1;
sigsetmask(mask);
}