fingerd.c revision 45393 
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 const 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#if 0
42static char sccsid[] = "@(#)fingerd.c	8.1 (Berkeley) 6/4/93";
43#endif
44static const char rcsid[] =
45	"$Id: fingerd.c,v 1.11 1998/05/15 03:23:28 jb Exp $";
46#endif /* not lint */
47
48#include <sys/param.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 sockaddr_in sin;
74	int p[2], logging, secure, sval;
75#define	ENTRIES	50
76	char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog;
77	char rhost[MAXHOSTNAMELEN + 1];
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:")) != -1)
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	/*
100	 * Enable server-side Transaction TCP.
101	 */
102	{
103#if	!defined(__alpha__) /* XXX FIXME */
104		int one = 1;
105		if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one,
106			       sizeof one) < 0) {
107			logerr("setsockopt(TCP_NOPUSH) failed: %m");
108		}
109#endif
110	}
111
112	if (!fgets(line, sizeof(line), stdin))
113		exit(1);
114
115	if (logging) {
116		char *t;
117		char *end;
118
119		end = memchr(line, 0, sizeof(line));
120		if (end == NULL) {
121			t = malloc(sizeof(line) + 1);
122			memcpy(t, line, sizeof(line));
123			t[sizeof(line)] = 0;
124		} else {
125			t = strdup(line);
126		}
127		for (end = t; *end; end++)
128			if (*end == '\n' || *end == '\r')
129				*end = ' ';
130		sval = sizeof(sin);
131		if (getpeername(0, (struct sockaddr *)&sin, &sval) < 0)
132			logerr("getpeername: %s", strerror(errno));
133		realhostname(rhost, sizeof rhost - 1, &sin.sin_addr);
134		syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t);
135	}
136
137	comp = &av[1];
138	av[2] = "--";
139	for (lp = line, ap = &av[3];;) {
140		*ap = strtok(lp, " \t\r\n");
141		if (!*ap) {
142			if (secure && ap == &av[3]) {
143				puts("must provide username\r\n");
144				exit(1);
145			}
146			break;
147		}
148		if (secure && strchr(*ap, '@')) {
149			puts("forwarding service denied\r\n");
150			exit(1);
151		}
152
153		/* RFC742: "/[Ww]" == "-l" */
154		if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
155			av[1] = "-l";
156			comp = &av[0];
157		}
158		else if (++ap == av + ENTRIES)
159			break;
160		lp = NULL;
161	}
162
163	if (lp = strrchr(prog, '/'))
164		*comp = ++lp;
165	else
166		*comp = prog;
167	if (pipe(p) < 0)
168		logerr("pipe: %s", strerror(errno));
169
170	switch(vfork()) {
171	case 0:
172		(void)close(p[0]);
173		if (p[1] != 1) {
174			(void)dup2(p[1], 1);
175			(void)close(p[1]);
176		}
177		execv(prog, comp);
178		logerr("execv: %s: %s", prog, strerror(errno));
179		_exit(1);
180	case -1:
181		logerr("fork: %s", strerror(errno));
182	}
183	(void)close(p[1]);
184	if (!(fp = fdopen(p[0], "r")))
185		logerr("fdopen: %s", strerror(errno));
186	while ((ch = getc(fp)) != EOF) {
187		if (ch == '\n')
188			putchar('\r');
189		putchar(ch);
190	}
191	exit(0);
192}
193
194#if __STDC__
195#include <stdarg.h>
196#else
197#include <varargs.h>
198#endif
199
200void
201#if __STDC__
202logerr(const char *fmt, ...)
203#else
204logerr(fmt, va_alist)
205	char *fmt;
206        va_dcl
207#endif
208{
209	va_list ap;
210#if __STDC__
211	va_start(ap, fmt);
212#else
213	va_start(ap);
214#endif
215	(void)vsyslog(LOG_ERR, fmt, ap);
216	va_end(ap);
217	exit(1);
218	/* NOTREACHED */
219}
220