xref: /netbsd-src/libexec/fingerd/fingerd.c (revision a5a68ff5f29de57339ca14f6c671c0a87714f1f8)
1 /*	$NetBSD: fingerd.c,v 1.6 1997/09/09 05:38:26 mrg 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 #ifndef lint
37 static char const copyright[] =
38 "@(#) Copyright (c) 1983, 1993\n\
39 	The Regents of the University of California.  All rights reserved.\n";
40 #endif /* not lint */
41 
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "from: @(#)fingerd.c	8.1 (Berkeley) 6/4/93";
45 #else
46 static char const rcsid[] = "$NetBSD: fingerd.c,v 1.6 1997/09/09 05:38:26 mrg Exp $";
47 #endif
48 #endif /* not lint */
49 
50 #include <sys/types.h>
51 #include <sys/socket.h>
52 #include <netinet/in.h>
53 #include <arpa/inet.h>
54 #include <errno.h>
55 
56 #include <unistd.h>
57 #include <syslog.h>
58 #include <netdb.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <strings.h>
62 #include "pathnames.h"
63 
64 void err __P((const char *, ...));
65 int main __P((int, char *[]));
66 
67 int
68 main(argc, argv)
69 	int argc;
70 	char *argv[];
71 {
72 	register FILE *fp;
73 	register int ch, ac = 2;
74 	register char *lp = NULL /* XXX gcc */;
75 	struct hostent *hp;
76 	struct sockaddr_in sin;
77 	int p[2], logging, no_forward, user_required, short_list, sval;
78 #define	ENTRIES	50
79 	char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog, *s;
80 
81 	prog = _PATH_FINGER;
82 	logging = no_forward = user_required = short_list = 0;
83 	openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON);
84 	opterr = 0;
85 	while ((ch = getopt(argc, argv, "gsluSmpP:")) != EOF)
86 		switch (ch) {
87 		case 'l':
88 			logging = 1;
89 			break;
90 		case 'P':
91 			prog = optarg;
92 			break;
93 		case 's':
94 			no_forward = 1;
95 			break;
96 		case 'u':
97 			user_required = 1;
98 			break;
99 		case 'S':
100 			short_list = 1;
101 			av[ac++] = "-s";
102 			break;
103 		case 'm':
104 			av[ac++] = "-m";
105 			break;
106 		case 'p':
107 			av[ac++] = "-p";
108 			break;
109 		case 'g':
110 			av[ac++] = "-g";
111 			break;
112 		case '?':
113 		default:
114 			err("illegal option -- %c", ch);
115 		}
116 
117 
118 	if (logging) {
119 		sval = sizeof(sin);
120 		if (getpeername(0, (struct sockaddr *)&sin, &sval) < 0)
121 			err("getpeername: %s", strerror(errno));
122 		if ((hp = gethostbyaddr((char *)&sin.sin_addr.s_addr,
123 		    sizeof(sin.sin_addr.s_addr), AF_INET)))
124 			lp = hp->h_name;
125 		else
126 			lp = inet_ntoa(sin.sin_addr);
127 	}
128 
129 	if (!fgets(line, sizeof(line), stdin)) {
130 		if (logging)
131 			syslog(LOG_NOTICE, "query from %s", lp);
132 		exit(1);
133 	}
134 	while ((s = strrchr(line, '\n')) != NULL ||
135 	    (s = strrchr(line, '\r')) != NULL)
136 		*s = '\0';
137 
138 	if (logging) {
139 		if (*line == '\0')
140 			syslog(LOG_NOTICE, "query from %s", lp);
141 		else
142 			syslog(LOG_NOTICE, "query from %s: %s", lp, line);
143 	}
144 
145 	av[ac++] = "--";
146 	comp = &av[1];
147 	for (lp = line, ap = &av[ac]; ac < ENTRIES;) {
148 		if ((*ap = strtok(lp, " \t\r\n")) == NULL)
149 			break;
150 		lp = NULL;
151 		if (no_forward && strchr(*ap, '@')) {
152 			(void) puts("fowarding service denied\r\n");
153 			exit(1);
154 		}
155 
156 		ch = strlen(*ap);
157 		while ((*ap)[ch-1] == '@')
158 			(*ap)[--ch] = '\0';
159 		if (**ap == '\0')
160 			continue;
161 
162 		/* RFC1196: "/[Ww]" == "-l" */
163 		if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
164 			if (!short_list) {
165 				av[1] = "-l";
166 				comp = &av[0];
167 			}
168 		} else {
169 			ap++;
170 			ac++;
171 		}
172 	}
173 	av[ENTRIES - 1] = NULL;
174 
175 	if ((lp = strrchr(prog, '/')))
176 		*comp = ++lp;
177 	else
178 		*comp = prog;
179 
180 	if (user_required) {
181 		for (ap = comp + 1; strcmp("--", *(ap++)); );
182 		if (*ap == NULL) {
183 			(void) puts("must provide username\r\n");
184 			exit(1);
185 		}
186 	}
187 
188 	if (pipe(p) < 0)
189 		err("pipe: %s", strerror(errno));
190 
191 	switch(fork()) {
192 	case 0:
193 		(void) close(p[0]);
194 		if (p[1] != 1) {
195 			(void) dup2(p[1], 1);
196 			(void) close(p[1]);
197 		}
198 		execv(prog, comp);
199 		err("execv: %s: %s", prog, strerror(errno));
200 		_exit(1);
201 	case -1:
202 		err("fork: %s", strerror(errno));
203 	}
204 	(void) close(p[1]);
205 	if (!(fp = fdopen(p[0], "r")))
206 		err("fdopen: %s", strerror(errno));
207 	while ((ch = getc(fp)) != EOF) {
208 		if (ch == '\n')
209 			putchar('\r');
210 		putchar(ch);
211 	}
212 	exit(0);
213 }
214 
215 #if __STDC__
216 #include <stdarg.h>
217 #else
218 #include <varargs.h>
219 #endif
220 
221 void
222 #if __STDC__
223 err(const char *fmt, ...)
224 #else
225 err(fmt, va_alist)
226 	char *fmt;
227         va_dcl
228 #endif
229 {
230 	va_list ap;
231 #if __STDC__
232 	va_start(ap, fmt);
233 #else
234 	va_start(ap);
235 #endif
236 	(void) vsyslog(LOG_ERR, fmt, ap);
237 	va_end(ap);
238 	exit(1);
239 	/* NOTREACHED */
240 }
241