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/* $OpenBSD: popen.c,v 1.8 2001/02/18 19:48:36 millert Exp $ */
/*
* Copyright (c) 1988 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software written by Ken Arnold and
* published in UNIX Review, Vol. 6, No. 8.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
*/
/* this came out of the ftpd sources; it's been modified to avoid the
* globbing stuff since we don't need it. also execvp instead of execv.
*/
#ifndef lint
static char rcsid[] = "$OpenBSD: popen.c,v 1.8 2001/02/18 19:48:36 millert Exp $";
static char sccsid[] = "@(#)popen.c 5.7 (Berkeley) 2/14/89";
#endif /* not lint */
#include "cron.h"
#define MAX_ARGS 100
#define MAX_GARGS 1000
#define WANT_GLOBBING 0
/*
* Special version of popen which avoids call to shell. This insures noone
* may create a pipe to a hidden program as a side effect of a list or dir
* command.
*/
static PID_T *pids;
static int fds;
FILE *
cron_popen(program, type, e)
char *program;
char *type;
entry *e;
{
char *cp;
FILE * volatile iop;
int argc, pdes[2];
PID_T pid;
char *argv[MAX_ARGS + 1];
#if WANT_GLOBBING
char **pop, *vv[2];
int gargc;
char *gargv[MAX_GARGS];
extern char **glob(), **copyblk();
#endif
if ((*type != 'r' && *type != 'w') || type[1] != '\0')
return (NULL);
if (!pids) {
if ((fds = sysconf(_SC_OPEN_MAX)) <= 0)
return (NULL);
if (!(pids = (PID_T *)malloc((size_t)(fds * sizeof(PID_T)))))
return (NULL);
bzero((char *)pids, fds * sizeof(PID_T));
}
if (pipe(pdes) < 0)
return (NULL);
/* break up string into pieces */
for (argc = 0, cp = program; argc < MAX_ARGS; cp = NULL)
if (!(argv[argc++] = strtok(cp, " \t\n")))
break;
argv[MAX_ARGS] = NULL;
#if WANT_GLOBBING
/* glob each piece */
gargv[0] = argv[0];
for (gargc = argc = 1; argv[argc]; argc++) {
if (!(pop = glob(argv[argc]))) { /* globbing failed */
vv[0] = argv[argc];
vv[1] = NULL;
pop = copyblk(vv);
}
argv[argc] = (char *)pop; /* save to free later */
while (*pop && gargc < MAX_GARGS)
gargv[gargc++] = *pop++;
}
gargv[gargc] = NULL;
#endif
iop = NULL;
switch(pid = vfork()) {
case -1: /* error */
(void)close(pdes[0]);
(void)close(pdes[1]);
goto pfree;
/* NOTREACHED */
case 0: /* child */
closelog();
if (*type == 'r') {
if (pdes[1] != 1) {
dup2(pdes[1], 1);
dup2(pdes[1], 2); /* stderr, too! */
(void)close(pdes[1]);
}
(void)close(pdes[0]);
} else {
if (pdes[0] != 0) {
dup2(pdes[0], 0);
(void)close(pdes[0]);
}
(void)close(pdes[1]);
}
if (e) {
#if defined(LOGIN_CAP)
struct passwd *pwd;
pwd = getpwuid(e->uid);
if (pwd == NULL) {
fprintf(stderr, "getpwuid: couldn't get entry for %d\n", e->uid);
_exit(ERROR_EXIT);
}
if (setusercontext(0, pwd, e->uid, LOGIN_SETALL) < 0) {
fprintf(stderr, "setusercontext failed for %d\n", e->uid);
_exit(ERROR_EXIT);
}
#else
if (setgid(e->gid) ||
setgroups(0, NULL) ||
initgroups(env_get("LOGNAME", e->envp), e->gid))
_exit(1);
setlogin(env_get("LOGNAME", e->envp));
if (setuid(e->uid))
_exit(1);
chdir(env_get("HOME", e->envp));
#endif /* LOGIN_CAP */
}
#if WANT_GLOBBING
execvp(gargv[0], gargv);
#else
execvp(argv[0], argv);
#endif
_exit(1);
}
/* parent; assume fdopen can't fail... */
if (*type == 'r') {
iop = fdopen(pdes[0], type);
(void)close(pdes[1]);
} else {
iop = fdopen(pdes[1], type);
(void)close(pdes[0]);
}
pids[fileno(iop)] = pid;
pfree:
#if WANT_GLOBBING
for (argc = 1; argv[argc] != NULL; argc++) {
/* blkfree((char **)argv[argc]); */
free((char *)argv[argc]);
}
#endif
return (iop);
}
int
cron_pclose(iop)
FILE *iop;
{
int fdes;
int omask;
WAIT_T stat_loc;
PID_T pid;
/*
* pclose returns -1 if stream is not associated with a
* `popened' command, or, if already `pclosed'.
*/
if (pids == 0 || pids[fdes = fileno(iop)] == 0)
return (-1);
(void)fclose(iop);
omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
while ((pid = wait(&stat_loc)) != pids[fdes] && pid != -1)
;
(void)sigsetmask(omask);
pids[fdes] = 0;
return (pid == -1 ? -1 : WEXITSTATUS(stat_loc));
}
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