xref: /minix3/libexec/fingerd/fingerd.c (revision 1d842c6a572919b97a89b154c4c3a6d5f11575ef)
1 /*	$NetBSD: fingerd.c,v 1.27 2012/03/15 02:02:21 joerg Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\
35  The Regents of the University of California.  All rights reserved.");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "from: @(#)fingerd.c	8.1 (Berkeley) 6/4/93";
41 #else
42 __RCSID("$NetBSD: fingerd.c,v 1.27 2012/03/15 02:02:21 joerg Exp $");
43 #endif
44 #endif /* not lint */
45 
46 #include <sys/param.h>
47 #include <sys/socket.h>
48 #include <netinet/in.h>
49 #include <arpa/inet.h>
50 #include <errno.h>
51 
52 #include <unistd.h>
53 #include <syslog.h>
54 #include <netdb.h>
55 #include <stdarg.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include "pathnames.h"
60 
61 __dead static void my_err(const char *, ...) __printflike(1, 2);
62 
63 int
main(int argc,char * argv[])64 main(int argc, char *argv[])
65 {
66 	FILE *fp;
67 	int ch, ac = 2;
68 	char *lp = NULL /* XXX gcc */;
69 	struct sockaddr_storage ss;
70 	int p[2], logging, no_forward, user_required, short_list;
71 	socklen_t sval;
72 #define	ENTRIES	50
73 	char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog, *s;
74 #if 0
75 	const char *av[ENTRIES + 1], **comp;
76 	const char *prog;
77 #endif
78 	char hostbuf[MAXHOSTNAMELEN];
79 
80 	prog = __UNCONST(_PATH_FINGER);
81 	logging = no_forward = user_required = short_list = 0;
82 	openlog("fingerd", LOG_PID, LOG_DAEMON);
83 	opterr = 0;
84 	while ((ch = getopt(argc, argv, "gsluShmpP:8")) != -1) {
85 		switch (ch) {
86 		case 'l':
87 			logging = 1;
88 			break;
89 		case 'P':
90 			prog = optarg;
91 			break;
92 		case 's':
93 			no_forward = 1;
94 			break;
95 		case 'u':
96 			user_required = 1;
97 			break;
98 		case 'S':
99 			short_list = 1;
100 			av[ac++] = __UNCONST("-s");
101 			break;
102 		case 'h':
103 			av[ac++] = __UNCONST("-h");
104 			break;
105 		case 'm':
106 			av[ac++] = __UNCONST("-m");
107 			break;
108 		case 'p':
109 			av[ac++] = __UNCONST("-p");
110 			break;
111 		case 'g':
112 			av[ac++] = __UNCONST("-g");
113 			break;
114 		case '8':
115 			av[ac++] = __UNCONST("-8");
116 			break;
117 		case '?':
118 		default:
119 			my_err("illegal option -- %c", optopt);
120 		}
121 		if (ac >= ENTRIES)
122 			my_err("Too many options provided");
123 	}
124 
125 
126 	if (logging) {
127 		sval = sizeof(ss);
128 		if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0)
129 			my_err("getpeername: %s", strerror(errno));
130 		(void)getnameinfo((struct sockaddr *)&ss, sval,
131 				hostbuf, sizeof(hostbuf), NULL, 0, 0);
132 		lp = hostbuf;
133 	}
134 
135 	if (!fgets(line, sizeof(line), stdin)) {
136 		if (logging)
137 			syslog(LOG_NOTICE, "query from %s", lp);
138 		exit(1);
139 	}
140 	while ((s = strrchr(line, '\n')) != NULL ||
141 	    (s = strrchr(line, '\r')) != NULL)
142 		*s = '\0';
143 
144 	if (logging) {
145 		if (*line == '\0')
146 			syslog(LOG_NOTICE, "query from %s", lp);
147 		else
148 			syslog(LOG_NOTICE, "query from %s: %s", lp, line);
149 	}
150 
151 	if (ac >= ENTRIES)
152 		my_err("Too many options provided");
153 	av[ac++] = __UNCONST("--");
154 	comp = &av[1];
155 	for (lp = line, ap = &av[ac]; ac < ENTRIES;) {
156 		if ((*ap = strtok(lp, " \t\r\n")) == NULL)
157 			break;
158 		lp = NULL;
159 		if (no_forward && strchr(*ap, '@')) {
160 			(void) puts("forwarding service denied\r\n");
161 			exit(1);
162 		}
163 
164 		ch = strlen(*ap);
165 		while ((*ap)[ch-1] == '@')
166 			(*ap)[--ch] = '\0';
167 		if (**ap == '\0')
168 			continue;
169 
170 		/* RFC1196: "/[Ww]" == "-l" */
171 		if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
172 			if (!short_list) {
173 				av[1] = __UNCONST("-l");
174 				comp = &av[0];
175 			}
176 		} else {
177 			ap++;
178 			ac++;
179 		}
180 	}
181 	av[ENTRIES - 1] = NULL;
182 
183 	if ((lp = strrchr(prog, '/')))
184 		*comp = ++lp;
185 	else
186 		*comp = prog;
187 
188 	if (user_required) {
189 		for (ap = comp + 1; strcmp("--", *(ap++)); );
190 		if (*ap == NULL) {
191 			(void) puts("must provide username\r\n");
192 			exit(1);
193 		}
194 	}
195 
196 	if (pipe(p) < 0)
197 		my_err("pipe: %s", strerror(errno));
198 
199 	switch(fork()) {
200 	case 0:
201 		(void) close(p[0]);
202 		if (p[1] != 1) {
203 			(void) dup2(p[1], 1);
204 			(void) close(p[1]);
205 		}
206 		execv(prog, comp);
207 		my_err("execv: %s: %s", prog, strerror(errno));
208 		_exit(1);
209 	case -1:
210 		my_err("fork: %s", strerror(errno));
211 	}
212 	(void) close(p[1]);
213 	if (!(fp = fdopen(p[0], "r")))
214 		my_err("fdopen: %s", strerror(errno));
215 	while ((ch = getc(fp)) != EOF) {
216 		if (ch == '\n')
217 			putchar('\r');
218 		putchar(ch);
219 	}
220 	exit(0);
221 }
222 
223 static void
my_err(const char * fmt,...)224 my_err(const char *fmt, ...)
225 {
226 	va_list ap;
227 
228 	va_start(ap, fmt);
229 	(void) vsyslog(LOG_ERR, fmt, ap);
230 	va_end(ap);
231 	exit(1);
232 	/* NOTREACHED */
233 }
234