fingerd.c revision 21673 
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
41/*
42static char sccsid[] = "@(#)fingerd.c	8.1 (Berkeley) 6/4/93";
43*/
44static const char rcsid[] =
45	"$FreeBSD: head/libexec/fingerd/fingerd.c 21673 1997-01-14 07:20:47Z jkh $";
46#endif /* not lint */
47
48#include <sys/types.h>
49#include <sys/socket.h>
50#include <netinet/in.h>
51#include <netinet/tcp.h>
52#include <arpa/inet.h>
53#include <errno.h>
54
55#include <unistd.h>
56#include <syslog.h>
57#include <netdb.h>
58#include <stdio.h>
59#include <stdlib.h>
60#include <strings.h>
61#include "pathnames.h"
62
63void logerr __P((const char *, ...));
64
65int
66main(argc, argv)
67	int argc;
68	char *argv[];
69{
70	register FILE *fp;
71	register int ch;
72	register char *lp;
73	struct hostent *hp;
74	struct sockaddr_in sin;
75	int p[2], logging, secure, sval;
76#define	ENTRIES	50
77	char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog;
78
79	prog = _PATH_FINGER;
80	logging = secure = 0;
81	openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON);
82	opterr = 0;
83	while ((ch = getopt(argc, argv, "slp:")) != EOF)
84		switch (ch) {
85		case 'l':
86			logging = 1;
87			break;
88		case 'p':
89			prog = optarg;
90			break;
91		case 's':
92			secure = 1;
93			break;
94		case '?':
95		default:
96			logerr("illegal option -- %c", ch);
97		}
98
99	if (logging) {
100		sval = sizeof(sin);
101		if (getpeername(0, (struct sockaddr *)&sin, &sval) < 0)
102			logerr("getpeername: %s", strerror(errno));
103		if (hp = gethostbyaddr((char *)&sin.sin_addr.s_addr,
104		    sizeof(sin.sin_addr.s_addr), AF_INET))
105			lp = hp->h_name;
106		else
107			lp = inet_ntoa(sin.sin_addr);
108		syslog(LOG_NOTICE, "query from %s", lp);
109	}
110
111	/*
112	 * Enable server-side Transaction TCP.
113	 */
114	{
115		int one = 1;
116		if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one,
117			       sizeof one) < 0) {
118			logerr("setsockopt(TCP_NOPUSH) failed: %m");
119		}
120	}
121
122	if (!fgets(line, sizeof(line), stdin))
123		exit(1);
124
125	comp = &av[1];
126	av[2] = "--";
127	for (lp = line, ap = &av[3];;) {
128		*ap = strtok(lp, " \t\r\n");
129		if (!*ap) {
130			if (secure && ap == &av[3]) {
131				puts("must provide username\r\n");
132				exit(1);
133			}
134			break;
135		}
136		if (secure && strchr(*ap, '@')) {
137			puts("forwarding service denied\r\n");
138			exit(1);
139		}
140
141		/* RFC742: "/[Ww]" == "-l" */
142		if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
143			av[1] = "-l";
144			comp = &av[0];
145		}
146		else if (++ap == av + ENTRIES)
147			break;
148		lp = NULL;
149	}
150
151	if (lp = strrchr(prog, '/'))
152		*comp = ++lp;
153	else
154		*comp = prog;
155	if (pipe(p) < 0)
156		logerr("pipe: %s", strerror(errno));
157
158	switch(vfork()) {
159	case 0:
160		(void)close(p[0]);
161		if (p[1] != 1) {
162			(void)dup2(p[1], 1);
163			(void)close(p[1]);
164		}
165		execv(prog, comp);
166		logerr("execv: %s: %s", prog, strerror(errno));
167		_exit(1);
168	case -1:
169		logerr("fork: %s", strerror(errno));
170	}
171	(void)close(p[1]);
172	if (!(fp = fdopen(p[0], "r")))
173		logerr("fdopen: %s", strerror(errno));
174	while ((ch = getc(fp)) != EOF) {
175		if (ch == '\n')
176			putchar('\r');
177		putchar(ch);
178	}
179	exit(0);
180}
181
182#if __STDC__
183#include <stdarg.h>
184#else
185#include <varargs.h>
186#endif
187
188void
189#if __STDC__
190logerr(const char *fmt, ...)
191#else
192logerr(fmt, va_alist)
193	char *fmt;
194        va_dcl
195#endif
196{
197	va_list ap;
198#if __STDC__
199	va_start(ap, fmt);
200#else
201	va_start(ap);
202#endif
203	(void)vsyslog(LOG_ERR, fmt, ap);
204	va_end(ap);
205	exit(1);
206	/* NOTREACHED */
207}
208