1 /* $OpenBSD: popen.c,v 1.31 2019/06/28 13:32:47 deraadt Exp $ */
2
3 /*
4 * Copyright (c) 1988, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software written by Ken Arnold and
8 * published in UNIX Review, Vol. 6, No. 8.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 */
35
36 /* this came out of the ftpd sources; it's been modified to avoid the
37 * globbing stuff since we don't need it. also execvp instead of execv.
38 */
39
40 #include <sys/types.h>
41 #include <sys/wait.h>
42
43 #include <bitstring.h> /* for structs.h */
44 #include <err.h>
45 #include <errno.h>
46 #include <login_cap.h>
47 #include <pwd.h>
48 #include <signal.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <syslog.h>
53 #include <unistd.h>
54 #include <time.h> /* for structs.h */
55
56 #include "macros.h"
57 #include "structs.h"
58 #include "funcs.h"
59
60 #define MAX_ARGV 100
61 #define MAX_GARGV 1000
62
63 /*
64 * Special version of popen which avoids call to shell
65 */
66 FILE *
cron_popen(char * program,char * type,struct passwd * pw,pid_t * pidptr)67 cron_popen(char *program, char *type, struct passwd *pw, pid_t *pidptr)
68 {
69 char *cp;
70 FILE *iop;
71 int argc, pdes[2];
72 pid_t pid;
73 char *argv[MAX_ARGV];
74
75 if ((*type != 'r' && *type != 'w') || type[1] != '\0')
76 return (NULL);
77
78 if (pipe(pdes) == -1)
79 return (NULL);
80
81 /* break up string into pieces */
82 for (argc = 0, cp = program; argc < MAX_ARGV - 1; cp = NULL)
83 if (!(argv[argc++] = strtok(cp, " \t\n")))
84 break;
85 argv[MAX_ARGV-1] = NULL;
86
87 switch (pid = fork()) {
88 case -1: /* error */
89 (void)close(pdes[0]);
90 (void)close(pdes[1]);
91 return (NULL);
92 /* NOTREACHED */
93 case 0: /* child */
94 if (pw) {
95 if (setusercontext(0, pw, pw->pw_uid, LOGIN_SETALL) == -1) {
96 syslog(LOG_ERR,
97 "(%s) SETUSERCONTEXT FAILED (%m)",
98 pw->pw_name);
99 warn("setusercontext failed for %s",
100 pw->pw_name);
101 _exit(EXIT_FAILURE);
102 }
103 }
104 if (*type == 'r') {
105 if (pdes[1] != STDOUT_FILENO) {
106 dup2(pdes[1], STDOUT_FILENO);
107 (void)close(pdes[1]);
108 }
109 dup2(STDOUT_FILENO, STDERR_FILENO);
110 (void)close(pdes[0]);
111 } else {
112 if (pdes[0] != STDIN_FILENO) {
113 dup2(pdes[0], STDIN_FILENO);
114 (void)close(pdes[0]);
115 }
116 (void)close(pdes[1]);
117 }
118 execvp(argv[0], argv);
119 _exit(1);
120 }
121
122 /* parent; assume fdopen can't fail... */
123 if (*type == 'r') {
124 iop = fdopen(pdes[0], type);
125 (void)close(pdes[1]);
126 } else {
127 iop = fdopen(pdes[1], type);
128 (void)close(pdes[0]);
129 }
130 *pidptr = pid;
131
132 return (iop);
133 }
134
135 int
cron_pclose(FILE * iop,pid_t pid)136 cron_pclose(FILE *iop, pid_t pid)
137 {
138 int rv;
139 int status;
140 sigset_t sigset, osigset;
141
142 (void)fclose(iop);
143 sigemptyset(&sigset);
144 sigaddset(&sigset, SIGINT);
145 sigaddset(&sigset, SIGQUIT);
146 sigaddset(&sigset, SIGHUP);
147 sigprocmask(SIG_BLOCK, &sigset, &osigset);
148 while ((rv = waitpid(pid, &status, 0)) == -1 && errno == EINTR)
149 continue;
150 sigprocmask(SIG_SETMASK, &osigset, NULL);
151 if (rv == -1)
152 return (rv);
153 if (WIFEXITED(status))
154 return (WEXITSTATUS(status));
155 return (1);
156 }
157