xref: /freebsd/crypto/heimdal/appl/ftp/ftpd/popen.c (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
1 /*
2  * Copyright (c) 1988, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software written by Ken Arnold and
6  * published in UNIX Review, Vol. 6, No. 8.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  */
37 
38 #ifdef HAVE_CONFIG_H
39 #include <config.h>
40 RCSID("$Id: popen.c,v 1.19 1999/09/16 20:38:45 assar Exp $");
41 #endif
42 
43 #include <sys/types.h>
44 #ifdef TIME_WITH_SYS_TIME
45 #include <sys/time.h>
46 #include <time.h>
47 #elif defined(HAVE_SYS_TIME_H)
48 #include <sys/time.h>
49 #else
50 #include <time.h>
51 #endif
52 #ifdef HAVE_SYS_RESOURCE_H
53 #include <sys/resource.h>
54 #endif
55 #include <sys/wait.h>
56 
57 #include <errno.h>
58 #include <glob.h>
59 #include <signal.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 #include <unistd.h>
64 
65 #include "extern.h"
66 
67 #include <roken.h>
68 
69 /*
70  * Special version of popen which avoids call to shell.  This ensures
71  * no one may create a pipe to a hidden program as a side effect of a
72  * list or dir command.
73  */
74 static int *pids;
75 static int fds;
76 
77 extern int dochroot;
78 
79 /* return path prepended with ~ftp if that file exists, otherwise
80  * return path unchanged
81  */
82 
83 const char *
84 ftp_rooted(const char *path)
85 {
86     static char home[MaxPathLen] = "";
87     static char newpath[MaxPathLen];
88     struct passwd *pwd;
89 
90     if(!home[0])
91 	if((pwd = k_getpwnam("ftp")))
92 	    strlcpy(home, pwd->pw_dir, sizeof(home));
93     snprintf(newpath, sizeof(newpath), "%s/%s", home, path);
94     if(access(newpath, X_OK))
95 	strlcpy(newpath, path, sizeof(newpath));
96     return newpath;
97 }
98 
99 
100 FILE *
101 ftpd_popen(char *program, char *type, int do_stderr, int no_glob)
102 {
103 	char *cp;
104 	FILE *iop;
105 	int argc, gargc, pdes[2], pid;
106 	char **pop, *argv[100], *gargv[1000];
107 	char *foo;
108 
109 	if (strcmp(type, "r") && strcmp(type, "w"))
110 		return (NULL);
111 
112 	if (!pids) {
113 
114 	    /* This function is ugly and should be rewritten, in
115 	     * modern unices there is no such thing as a maximum
116 	     * filedescriptor.
117 	     */
118 
119 	    fds = getdtablesize();
120 	    pids = (int*)calloc(fds, sizeof(int));
121 	    if(!pids)
122 		return NULL;
123 	}
124 	if (pipe(pdes) < 0)
125 		return (NULL);
126 
127 	/* break up string into pieces */
128 	foo = NULL;
129 	for (argc = 0, cp = program;; cp = NULL) {
130 		if (!(argv[argc++] = strtok_r(cp, " \t\n", &foo)))
131 			break;
132 	}
133 
134 	gargv[0] = (char*)ftp_rooted(argv[0]);
135 	/* glob each piece */
136 	for (gargc = argc = 1; argv[argc]; argc++) {
137 		glob_t gl;
138 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE;
139 
140 		memset(&gl, 0, sizeof(gl));
141 		if (no_glob || glob(argv[argc], flags, NULL, &gl))
142 			gargv[gargc++] = strdup(argv[argc]);
143 		else
144 			for (pop = gl.gl_pathv; *pop; pop++)
145 				gargv[gargc++] = strdup(*pop);
146 		globfree(&gl);
147 	}
148 	gargv[gargc] = NULL;
149 
150 	iop = NULL;
151 	switch(pid = fork()) {
152 	case -1:			/* error */
153 		close(pdes[0]);
154 		close(pdes[1]);
155 		goto pfree;
156 		/* NOTREACHED */
157 	case 0:				/* child */
158 		if (*type == 'r') {
159 			if (pdes[1] != STDOUT_FILENO) {
160 				dup2(pdes[1], STDOUT_FILENO);
161 				close(pdes[1]);
162 			}
163 			if(do_stderr)
164 			    dup2(STDOUT_FILENO, STDERR_FILENO);
165 			close(pdes[0]);
166 		} else {
167 			if (pdes[0] != STDIN_FILENO) {
168 				dup2(pdes[0], STDIN_FILENO);
169 				close(pdes[0]);
170 			}
171 			close(pdes[1]);
172 		}
173 		execv(gargv[0], gargv);
174 		gargv[0] = argv[0];
175 		execv(gargv[0], gargv);
176 		_exit(1);
177 	}
178 	/* parent; assume fdopen can't fail...  */
179 	if (*type == 'r') {
180 		iop = fdopen(pdes[0], type);
181 		close(pdes[1]);
182 	} else {
183 		iop = fdopen(pdes[1], type);
184 		close(pdes[0]);
185 	}
186 	pids[fileno(iop)] = pid;
187 
188 pfree:
189 	for (argc = 1; gargv[argc] != NULL; argc++)
190 	    free(gargv[argc]);
191 
192 
193 	return (iop);
194 }
195 
196 int
197 ftpd_pclose(FILE *iop)
198 {
199 	int fdes, status;
200 	pid_t pid;
201 	sigset_t sigset, osigset;
202 
203 	/*
204 	 * pclose returns -1 if stream is not associated with a
205 	 * `popened' command, or, if already `pclosed'.
206 	 */
207 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
208 		return (-1);
209 	fclose(iop);
210 	sigemptyset(&sigset);
211 	sigaddset(&sigset, SIGINT);
212 	sigaddset(&sigset, SIGQUIT);
213 	sigaddset(&sigset, SIGHUP);
214 	sigprocmask(SIG_BLOCK, &sigset, &osigset);
215 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
216 		continue;
217 	sigprocmask(SIG_SETMASK, &osigset, NULL);
218 	pids[fdes] = 0;
219 	if (pid < 0)
220 		return (pid);
221 	if (WIFEXITED(status))
222 		return (WEXITSTATUS(status));
223 	return (1);
224 }
225