/* $NetBSD: popen.c,v 1.1 2018/01/09 03:31:15 christos Exp $ */
/*
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
* Copyright (c) 2017 The NetBSD Foundation, Inc.
* Copyright (c) 2016 The DragonFly Project
* Copyright (c) 2014 The FreeBSD Foundation
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Tomohiro Kusumi <
[email protected]>.
*
* This code is derived from software written by Ken Arnold and
* published in UNIX Review, Vol. 6, No. 8.
*
* Portions of this software were developed by Edward Tomasz Napierala
* under sponsorship from the FreeBSD Foundation.
*
* 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. 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.
*
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: popen.c,v 1.1 2018/01/09 03:31:15 christos Exp $");
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/wait.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "common.h"
extern char **environ;
struct pid {
SLIST_ENTRY(pid) next;
FILE *outfp;
pid_t pid;
char *command;
};
static SLIST_HEAD(, pid) pidlist = SLIST_HEAD_INITIALIZER(pidlist);
#define ARGV_LEN 42
/*
* Replacement for popen(3), without stdin (which we do not use), but with
* stderr, proper logging, and improved command line arguments passing.
* Error handling is built in - if it returns, then it succeeded.
*/
FILE *
auto_popen(const char *argv0, ...)
{
va_list ap;
struct pid *cur, *p;
pid_t pid;
int error, i, nullfd, outfds[2];
char *arg, *argv[ARGV_LEN], *command;
nullfd = open(_PATH_DEVNULL, O_RDWR, 0);
if (nullfd < 0)
log_err(1, "cannot open %s", _PATH_DEVNULL);
error = pipe(outfds);
if (error != 0)
log_err(1, "pipe");
cur = malloc(sizeof(struct pid));
if (cur == NULL)
log_err(1, "malloc");
argv[0] = checked_strdup(argv0);
command = argv[0];
va_start(ap, argv0);
for (i = 1;; i++) {
if (i >= ARGV_LEN)
log_errx(1, "too many arguments to auto_popen");
arg = va_arg(ap, char *);
argv[i] = arg;
if (arg == NULL)
break;
command = concat(command, ' ', arg);
}
va_end(ap);
cur->command = checked_strdup(command);
switch (pid = fork()) {
case -1: /* Error. */
log_err(1, "fork");
/* NOTREACHED */
case 0: /* Child. */
dup2(nullfd, STDIN_FILENO);
dup2(outfds[1], STDOUT_FILENO);
close(nullfd);
close(outfds[0]);
close(outfds[1]);
SLIST_FOREACH(p, &pidlist, next)
close(fileno(p->outfp));
execvp(argv[0], argv);
log_err(1, "failed to execute %s", argv[0]);
/* NOTREACHED */
}
log_debugx("executing \"%s\" as pid %d", command, pid);
/* Parent; assume fdopen cannot fail. */
cur->outfp = fdopen(outfds[0], "r");
close(nullfd);
close(outfds[1]);
/* Link into list of file descriptors. */
cur->pid = pid;
SLIST_INSERT_HEAD(&pidlist, cur, next);
return cur->outfp;
}
int
auto_pclose(FILE *iop)
{
struct pid *cur, *last = NULL;
int status;
pid_t pid;
/*
* Find the appropriate file pointer and remove it from the list.
*/
SLIST_FOREACH(cur, &pidlist, next) {
if (cur->outfp == iop)
break;
last = cur;
}
if (cur == NULL) {
return -1;
}
if (last == NULL)
SLIST_REMOVE_HEAD(&pidlist, next);
else
SLIST_REMOVE_AFTER(last, next);
fclose(cur->outfp);
do {
pid = wait4(cur->pid, &status, 0, NULL);
} while (pid == -1 && errno == EINTR);
if (WIFSIGNALED(status)) {
log_warnx("\"%s\", pid %d, terminated with signal %d",
cur->command, pid, WTERMSIG(status));
return status;
}
if (WEXITSTATUS(status) != 0) {
log_warnx("\"%s\", pid %d, terminated with exit status %d",
cur->command, pid, WEXITSTATUS(status));
return status;
}
log_debugx("\"%s\", pid %d, terminated gracefully", cur->command, pid);
free(cur->command);
free(cur);
return pid == -1 ? -1 : status;
}
