xref: /freebsd/crypto/heimdal/appl/ftp/ftpd/popen.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
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("$Id$");
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 #include <roken.h>
65 #include "extern.h"
66 
67 
68 /*
69  * Special version of popen which avoids call to shell.  This ensures
70  * no one may create a pipe to a hidden program as a side effect of a
71  * list or dir command.
72  */
73 static int *pids;
74 static int fds;
75 
76 /* return path prepended with ~ftp if that file exists, otherwise
77  * return path unchanged
78  */
79 
80 const char *
81 ftp_rooted(const char *path)
82 {
83     static char home[MaxPathLen] = "";
84     static char newpath[MaxPathLen];
85     struct passwd *pwd;
86 
87     if(!home[0])
88 	if((pwd = k_getpwnam("ftp")))
89 	    strlcpy(home, pwd->pw_dir, sizeof(home));
90     snprintf(newpath, sizeof(newpath), "%s/%s", home, path);
91     if(access(newpath, X_OK))
92 	strlcpy(newpath, path, sizeof(newpath));
93     return newpath;
94 }
95 
96 
97 #define MAXARGS	100
98 #define MAXGLOBS 1000
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[MAXARGS], *gargv[MAXGLOBS];
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; argc < MAXARGS - 1; cp = NULL) {
130 		if (!(argv[argc++] = strtok_r(cp, " \t\n", &foo)))
131 			break;
132 	}
133 	argv[MAXARGS - 1] = NULL;
134 
135 	gargv[0] = (char*)ftp_rooted(argv[0]);
136 	/* glob each piece */
137 	for (gargc = argc = 1; argv[argc] && gargc < MAXGLOBS - 1; argc++) {
138 		glob_t gl;
139 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE
140 		    |
141 #ifdef GLOB_MAXPATH
142 	GLOB_MAXPATH
143 #else
144 	GLOB_LIMIT
145 #endif
146 		    ;
147 
148 		memset(&gl, 0, sizeof(gl));
149 		if (no_glob ||
150 		    glob(argv[argc], flags, NULL, &gl) ||
151 		    gl.gl_pathc == 0)
152 			gargv[gargc++] = strdup(argv[argc]);
153 		else
154 			for (pop = gl.gl_pathv;
155 			     *pop && gargc < MAXGLOBS - 1;
156 			     pop++)
157 				gargv[gargc++] = strdup(*pop);
158 		globfree(&gl);
159 	}
160 	gargv[gargc] = NULL;
161 
162 	iop = NULL;
163 	switch(pid = fork()) {
164 	case -1:			/* error */
165 		close(pdes[0]);
166 		close(pdes[1]);
167 		goto pfree;
168 		/* NOTREACHED */
169 	case 0:				/* child */
170 		if (*type == 'r') {
171 			if (pdes[1] != STDOUT_FILENO) {
172 				dup2(pdes[1], STDOUT_FILENO);
173 				close(pdes[1]);
174 			}
175 			if(do_stderr)
176 			    dup2(STDOUT_FILENO, STDERR_FILENO);
177 			close(pdes[0]);
178 		} else {
179 			if (pdes[0] != STDIN_FILENO) {
180 				dup2(pdes[0], STDIN_FILENO);
181 				close(pdes[0]);
182 			}
183 			close(pdes[1]);
184 		}
185 		execv(gargv[0], gargv);
186 		gargv[0] = argv[0];
187 		execv(gargv[0], gargv);
188 		_exit(1);
189 	}
190 	/* parent; assume fdopen can't fail...  */
191 	if (*type == 'r') {
192 		iop = fdopen(pdes[0], type);
193 		close(pdes[1]);
194 	} else {
195 		iop = fdopen(pdes[1], type);
196 		close(pdes[0]);
197 	}
198 	pids[fileno(iop)] = pid;
199 
200 pfree:
201 	for (argc = 1; gargv[argc] != NULL; argc++)
202 	    free(gargv[argc]);
203 
204 
205 	return (iop);
206 }
207 
208 int
209 ftpd_pclose(FILE *iop)
210 {
211 	int fdes, status;
212 	pid_t pid;
213 	sigset_t sigset, osigset;
214 
215 	/*
216 	 * pclose returns -1 if stream is not associated with a
217 	 * `popened' command, or, if already `pclosed'.
218 	 */
219 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
220 		return (-1);
221 	fclose(iop);
222 	sigemptyset(&sigset);
223 	sigaddset(&sigset, SIGINT);
224 	sigaddset(&sigset, SIGQUIT);
225 	sigaddset(&sigset, SIGHUP);
226 	sigprocmask(SIG_BLOCK, &sigset, &osigset);
227 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
228 		continue;
229 	sigprocmask(SIG_SETMASK, &osigset, NULL);
230 	pids[fdes] = 0;
231 	if (pid < 0)
232 		return (pid);
233 	if (WIFEXITED(status))
234 		return (WEXITSTATUS(status));
235 	return (1);
236 }
237