xref: /original-bsd/libexec/ftpd/popen.c (revision e58c8952)
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  * %sccs.include.redist.c%
9  *
10  */
11 
12 #ifndef lint
13 static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 04/06/94";
14 #endif /* not lint */
15 
16 #include <sys/types.h>
17 #include <sys/wait.h>
18 
19 #include <errno.h>
20 #include <glob.h>
21 #include <signal.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <unistd.h>
26 
27 #include "extern.h"
28 
29 /*
30  * Special version of popen which avoids call to shell.  This ensures noone
31  * may create a pipe to a hidden program as a side effect of a list or dir
32  * command.
33  */
34 static int *pids;
35 static int fds;
36 
37 FILE *
38 ftpd_popen(program, type)
39 	char *program, *type;
40 {
41 	char *cp;
42 	FILE *iop;
43 	int argc, gargc, pdes[2], pid;
44 	char **pop, *argv[100], *gargv[1000];
45 
46 	if (*type != 'r' && *type != 'w' || type[1])
47 		return (NULL);
48 
49 	if (!pids) {
50 		if ((fds = getdtablesize()) <= 0)
51 			return (NULL);
52 		if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
53 			return (NULL);
54 		memset(pids, 0, fds * sizeof(int));
55 	}
56 	if (pipe(pdes) < 0)
57 		return (NULL);
58 
59 	/* break up string into pieces */
60 	for (argc = 0, cp = program;; cp = NULL)
61 		if (!(argv[argc++] = strtok(cp, " \t\n")))
62 			break;
63 
64 	/* glob each piece */
65 	gargv[0] = argv[0];
66 	for (gargc = argc = 1; argv[argc]; argc++) {
67 		glob_t gl;
68 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE;
69 
70 		memset(&gl, 0, sizeof(gl));
71 		if (glob(argv[argc], flags, NULL, &gl))
72 			gargv[gargc++] = strdup(argv[argc]);
73 		else
74 			for (pop = gl.gl_pathv; *pop; pop++)
75 				gargv[gargc++] = strdup(*pop);
76 		globfree(&gl);
77 	}
78 	gargv[gargc] = NULL;
79 
80 	iop = NULL;
81 	switch(pid = vfork()) {
82 	case -1:			/* error */
83 		(void)close(pdes[0]);
84 		(void)close(pdes[1]);
85 		goto pfree;
86 		/* NOTREACHED */
87 	case 0:				/* child */
88 		if (*type == 'r') {
89 			if (pdes[1] != STDOUT_FILENO) {
90 				dup2(pdes[1], STDOUT_FILENO);
91 				(void)close(pdes[1]);
92 			}
93 			dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
94 			(void)close(pdes[0]);
95 		} else {
96 			if (pdes[0] != STDIN_FILENO) {
97 				dup2(pdes[0], STDIN_FILENO);
98 				(void)close(pdes[0]);
99 			}
100 			(void)close(pdes[1]);
101 		}
102 		execv(gargv[0], gargv);
103 		_exit(1);
104 	}
105 	/* parent; assume fdopen can't fail...  */
106 	if (*type == 'r') {
107 		iop = fdopen(pdes[0], type);
108 		(void)close(pdes[1]);
109 	} else {
110 		iop = fdopen(pdes[1], type);
111 		(void)close(pdes[0]);
112 	}
113 	pids[fileno(iop)] = pid;
114 
115 pfree:	for (argc = 1; gargv[argc] != NULL; argc++)
116 		free(gargv[argc]);
117 
118 	return (iop);
119 }
120 
121 int
122 ftpd_pclose(iop)
123 	FILE *iop;
124 {
125 	int fdes, omask, status;
126 	pid_t pid;
127 
128 	/*
129 	 * pclose returns -1 if stream is not associated with a
130 	 * `popened' command, or, if already `pclosed'.
131 	 */
132 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
133 		return (-1);
134 	(void)fclose(iop);
135 	omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
136 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
137 		continue;
138 	(void)sigsetmask(omask);
139 	pids[fdes] = 0;
140 	if (pid < 0)
141 		return (pid);
142 	if (WIFEXITED(status))
143 		return (WEXITSTATUS(status));
144 	return (1);
145 }
146