1 /*
2 * Copyright (c) 1988 The Regents of the University of California.
3 * 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 #ifndef lint
39 static char sccsid[] = "@(#)popen.c 5.9 (Berkeley) 2/25/91";
40 #endif /* not lint */
41
42 #include <sys/types.h>
43 #include <sys/wait.h>
44 #include <signal.h>
45 #include <unistd.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49
50 /*
51 * Special version of popen which avoids call to shell. This insures noone
52 * may create a pipe to a hidden program as a side effect of a list or dir
53 * command.
54 */
55 static int *pids;
56 static int fds;
57
58 FILE *
ftpd_popen(program,type)59 ftpd_popen(program, type)
60 char *program, *type;
61 {
62 register char *cp;
63 FILE *iop;
64 int argc, gargc, pdes[2], pid;
65 char **pop, *argv[100], *gargv[1000], *vv[2];
66 extern char **ftpglob(), **copyblk();
67
68 if (*type != 'r' && *type != 'w' || type[1])
69 return(NULL);
70
71 if (!pids) {
72 if ((fds = getdtablesize()) <= 0)
73 return(NULL);
74 if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
75 return(NULL);
76 bzero((char *)pids, fds * sizeof(int));
77 }
78 if (pipe(pdes) < 0)
79 return(NULL);
80
81 /* break up string into pieces */
82 for (argc = 0, cp = program;; cp = NULL)
83 if (!(argv[argc++] = strtok(cp, " \t\n")))
84 break;
85
86 /* glob each piece */
87 gargv[0] = argv[0];
88 for (gargc = argc = 1; argv[argc]; argc++) {
89 if (!(pop = ftpglob(argv[argc]))) { /* globbing failed */
90 vv[0] = argv[argc];
91 vv[1] = NULL;
92 pop = copyblk(vv);
93 }
94 argv[argc] = (char *)pop; /* save to free later */
95 while (*pop && gargc < 1000)
96 gargv[gargc++] = *pop++;
97 }
98 gargv[gargc] = NULL;
99
100 iop = NULL;
101 switch(pid = vfork()) {
102 case -1: /* error */
103 (void)close(pdes[0]);
104 (void)close(pdes[1]);
105 goto pfree;
106 /* NOTREACHED */
107 case 0: /* child */
108 if (*type == 'r') {
109 if (pdes[1] != 1) {
110 dup2(pdes[1], 1);
111 dup2(pdes[1], 2); /* stderr, too! */
112 (void)close(pdes[1]);
113 }
114 (void)close(pdes[0]);
115 } else {
116 if (pdes[0] != 0) {
117 dup2(pdes[0], 0);
118 (void)close(pdes[0]);
119 }
120 (void)close(pdes[1]);
121 }
122 execv(gargv[0], gargv);
123 _exit(1);
124 }
125 /* parent; assume fdopen can't fail... */
126 if (*type == 'r') {
127 iop = fdopen(pdes[0], type);
128 (void)close(pdes[1]);
129 } else {
130 iop = fdopen(pdes[1], type);
131 (void)close(pdes[0]);
132 }
133 pids[fileno(iop)] = pid;
134
135 pfree: for (argc = 1; argv[argc] != NULL; argc++) {
136 blkfree((char **)argv[argc]);
137 free((char *)argv[argc]);
138 }
139 return(iop);
140 }
141
ftpd_pclose(iop)142 ftpd_pclose(iop)
143 FILE *iop;
144 {
145 register int fdes;
146 int omask;
147 union wait stat_loc;
148 int pid;
149
150 /*
151 * pclose returns -1 if stream is not associated with a
152 * `popened' command, or, if already `pclosed'.
153 */
154 if (pids == 0 || pids[fdes = fileno(iop)] == 0)
155 return(-1);
156 (void)fclose(iop);
157 omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
158 while ((pid = wait((int *)&stat_loc)) != pids[fdes] && pid != -1);
159 (void)sigsetmask(omask);
160 pids[fdes] = 0;
161 return(pid == -1 ? -1 : stat_loc.w_status);
162 }
163