xref: /netbsd/libexec/fingerd/fingerd.c (revision c4a72b64)
1 /*	$NetBSD: fingerd.c,v 1.19 2002/09/12 01:40:54 kim 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT(
39 "@(#) Copyright (c) 1983, 1993\n\
40 	The Regents of the University of California.  All rights reserved.\n");
41 #endif /* not lint */
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "from: @(#)fingerd.c	8.1 (Berkeley) 6/4/93";
46 #else
47 __RCSID("$NetBSD: fingerd.c,v 1.19 2002/09/12 01:40:54 kim Exp $");
48 #endif
49 #endif /* not lint */
50 
51 #include <sys/param.h>
52 #include <sys/socket.h>
53 #include <netinet/in.h>
54 #include <arpa/inet.h>
55 #include <errno.h>
56 
57 #include <unistd.h>
58 #include <syslog.h>
59 #include <netdb.h>
60 #include <stdarg.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 #include "pathnames.h"
65 
66 void err __P((const char *, ...));
67 int main __P((int, char *[]));
68 
69 int
70 main(argc, argv)
71 	int argc;
72 	char *argv[];
73 {
74 	register FILE *fp;
75 	register int ch, ac = 2;
76 	register char *lp = NULL /* XXX gcc */;
77 	struct sockaddr_storage ss;
78 	int p[2], logging, no_forward, user_required, short_list, sval;
79 #define	ENTRIES	50
80 	char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog, *s;
81 	char hostbuf[MAXHOSTNAMELEN];
82 
83 	prog = _PATH_FINGER;
84 	logging = no_forward = user_required = short_list = 0;
85 	openlog("fingerd", LOG_PID, LOG_DAEMON);
86 	opterr = 0;
87 	while ((ch = getopt(argc, argv, "gsluShmpP:8")) != -1)
88 		switch (ch) {
89 		case 'l':
90 			logging = 1;
91 			break;
92 		case 'P':
93 			prog = optarg;
94 			break;
95 		case 's':
96 			no_forward = 1;
97 			break;
98 		case 'u':
99 			user_required = 1;
100 			break;
101 		case 'S':
102 			short_list = 1;
103 			av[ac++] = "-s";
104 			break;
105 		case 'h':
106 			av[ac++] = "-h";
107 			break;
108 		case 'm':
109 			av[ac++] = "-m";
110 			break;
111 		case 'p':
112 			av[ac++] = "-p";
113 			break;
114 		case 'g':
115 			av[ac++] = "-g";
116 			break;
117 		case '8':
118 			av[ac++] = "-8";
119 			break;
120 		case '?':
121 		default:
122 			err("illegal option -- %c", ch);
123 		}
124 
125 
126 	if (logging) {
127 		sval = sizeof(ss);
128 		if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0)
129 			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 	av[ac++] = "--";
152 	comp = &av[1];
153 	for (lp = line, ap = &av[ac]; ac < ENTRIES;) {
154 		if ((*ap = strtok(lp, " \t\r\n")) == NULL)
155 			break;
156 		lp = NULL;
157 		if (no_forward && strchr(*ap, '@')) {
158 			(void) puts("forwarding service denied\r\n");
159 			exit(1);
160 		}
161 
162 		ch = strlen(*ap);
163 		while ((*ap)[ch-1] == '@')
164 			(*ap)[--ch] = '\0';
165 		if (**ap == '\0')
166 			continue;
167 
168 		/* RFC1196: "/[Ww]" == "-l" */
169 		if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
170 			if (!short_list) {
171 				av[1] = "-l";
172 				comp = &av[0];
173 			}
174 		} else {
175 			ap++;
176 			ac++;
177 		}
178 	}
179 	av[ENTRIES - 1] = NULL;
180 
181 	if ((lp = strrchr(prog, '/')))
182 		*comp = ++lp;
183 	else
184 		*comp = prog;
185 
186 	if (user_required) {
187 		for (ap = comp + 1; strcmp("--", *(ap++)); );
188 		if (*ap == NULL) {
189 			(void) puts("must provide username\r\n");
190 			exit(1);
191 		}
192 	}
193 
194 	if (pipe(p) < 0)
195 		err("pipe: %s", strerror(errno));
196 
197 	switch(fork()) {
198 	case 0:
199 		(void) close(p[0]);
200 		if (p[1] != 1) {
201 			(void) dup2(p[1], 1);
202 			(void) close(p[1]);
203 		}
204 		execv(prog, comp);
205 		err("execv: %s: %s", prog, strerror(errno));
206 		_exit(1);
207 	case -1:
208 		err("fork: %s", strerror(errno));
209 	}
210 	(void) close(p[1]);
211 	if (!(fp = fdopen(p[0], "r")))
212 		err("fdopen: %s", strerror(errno));
213 	while ((ch = getc(fp)) != EOF) {
214 		if (ch == '\n')
215 			putchar('\r');
216 		putchar(ch);
217 	}
218 	exit(0);
219 }
220 
221 void
222 err(const char *fmt, ...)
223 {
224 	va_list ap;
225 
226 	va_start(ap, fmt);
227 	(void) vsyslog(LOG_ERR, fmt, ap);
228 	va_end(ap);
229 	exit(1);
230 	/* NOTREACHED */
231 }
232