fingerd.c revision 12728 
1/*
2 * Copyright (c) 1983, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35static char copyright[] =
36"@(#) Copyright (c) 1983, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41static char sccsid[] = "@(#)fingerd.c	8.1 (Berkeley) 6/4/93";
42#endif /* not lint */
43
44#include <sys/types.h>
45#include <sys/socket.h>
46#include <netinet/in.h>
47#include <arpa/inet.h>
48#include <errno.h>
49
50#include <unistd.h>
51#include <syslog.h>
52#include <netdb.h>
53#include <stdio.h>
54#include <stdlib.h>
55#include <strings.h>
56#include "pathnames.h"
57
58void err __P((const char *, ...));
59
60int
61main(argc, argv)
62	int argc;
63	char *argv[];
64{
65	register FILE *fp;
66	register int ch;
67	register char *lp;
68	struct hostent *hp;
69	struct sockaddr_in sin;
70	int p[2], logging, secure, sval;
71#define	ENTRIES	50
72	char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog;
73
74	prog = _PATH_FINGER;
75	logging = secure = 0;
76	openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON);
77	opterr = 0;
78	while ((ch = getopt(argc, argv, "slp:")) != EOF)
79		switch (ch) {
80		case 'l':
81			logging = 1;
82			break;
83		case 'p':
84			prog = optarg;
85			break;
86		case 's':
87			secure = 1;
88			break;
89		case '?':
90		default:
91			err("illegal option -- %c", ch);
92		}
93
94	if (logging) {
95		sval = sizeof(sin);
96		if (getpeername(0, (struct sockaddr *)&sin, &sval) < 0)
97			err("getpeername: %s", strerror(errno));
98		if (hp = gethostbyaddr((char *)&sin.sin_addr.s_addr,
99		    sizeof(sin.sin_addr.s_addr), AF_INET))
100			lp = hp->h_name;
101		else
102			lp = inet_ntoa(sin.sin_addr);
103		syslog(LOG_NOTICE, "query from %s", lp);
104	}
105
106	if (!fgets(line, sizeof(line), stdin))
107		exit(1);
108
109	comp = &av[1];
110	av[2] = "--";
111	for (lp = line, ap = &av[3];;) {
112		*ap = strtok(lp, " \t\r\n");
113		if (!*ap) {
114			if (secure && ap == &av[3]) {
115				puts("must provide username\r\n");
116				exit(1);
117			}
118			break;
119		}
120		if (secure && strchr(*ap, '@')) {
121			puts("forwarding service denied\r\n");
122			exit(1);
123		}
124
125		/* RFC742: "/[Ww]" == "-l" */
126		if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
127			av[1] = "-l";
128			comp = &av[0];
129		}
130		else if (++ap == av + ENTRIES)
131			break;
132		lp = NULL;
133	}
134
135	if (lp = strrchr(prog, '/'))
136		*comp = ++lp;
137	else
138		*comp = prog;
139	if (pipe(p) < 0)
140		err("pipe: %s", strerror(errno));
141
142	switch(vfork()) {
143	case 0:
144		(void)close(p[0]);
145		if (p[1] != 1) {
146			(void)dup2(p[1], 1);
147			(void)close(p[1]);
148		}
149		execv(prog, comp);
150		err("execv: %s: %s", prog, strerror(errno));
151		_exit(1);
152	case -1:
153		err("fork: %s", strerror(errno));
154	}
155	(void)close(p[1]);
156	if (!(fp = fdopen(p[0], "r")))
157		err("fdopen: %s", strerror(errno));
158	while ((ch = getc(fp)) != EOF) {
159		if (ch == '\n')
160			putchar('\r');
161		putchar(ch);
162	}
163	exit(0);
164}
165
166#if __STDC__
167#include <stdarg.h>
168#else
169#include <varargs.h>
170#endif
171
172void
173#if __STDC__
174err(const char *fmt, ...)
175#else
176err(fmt, va_alist)
177	char *fmt;
178        va_dcl
179#endif
180{
181	va_list ap;
182#if __STDC__
183	va_start(ap, fmt);
184#else
185	va_start(ap);
186#endif
187	(void)vsyslog(LOG_ERR, fmt, ap);
188	va_end(ap);
189	exit(1);
190	/* NOTREACHED */
191}
192