xref: /freebsd/libexec/fingerd/fingerd.c (revision 1b6c76a2fe091c74f08427e6c870851025a9cf67)
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
35 static 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
42 static char sccsid[] = "@(#)fingerd.c	8.1 (Berkeley) 6/4/93";
43 #endif
44 static const char rcsid[] =
45   "$FreeBSD$";
46 #endif /* not lint */
47 
48 #include <sys/types.h>
49 #include <sys/param.h>
50 #include <sys/socket.h>
51 #include <netinet/in.h>
52 #include <netinet/tcp.h>
53 #include <arpa/inet.h>
54 #include <errno.h>
55 
56 #include <unistd.h>
57 #include <syslog.h>
58 #include <libutil.h>
59 #include <netdb.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <strings.h>
63 #include "pathnames.h"
64 
65 void logerr __P((const char *, ...));
66 
67 int
68 main(argc, argv)
69 	int argc;
70 	char *argv[];
71 {
72 	register FILE *fp;
73 	register int ch;
74 	register char *lp;
75 	struct sockaddr_storage ss;
76 	int p[2], logging, secure, sval;
77 #define	ENTRIES	50
78 	char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog;
79 	char rhost[MAXHOSTNAMELEN];
80 
81 	prog = _PATH_FINGER;
82 	logging = secure = 0;
83 	openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON);
84 	opterr = 0;
85 	while ((ch = getopt(argc, argv, "slp:")) != -1)
86 		switch (ch) {
87 		case 'l':
88 			logging = 1;
89 			break;
90 		case 'p':
91 			prog = optarg;
92 			break;
93 		case 's':
94 			secure = 1;
95 			break;
96 		case '?':
97 		default:
98 			logerr("illegal option -- %c", optopt);
99 		}
100 
101 	/*
102 	 * Enable server-side Transaction TCP.
103 	 */
104 	{
105 #if	!defined(__alpha__) /* XXX FIXME */
106 		int one = 1;
107 		if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one,
108 			       sizeof one) < 0) {
109 			logerr("setsockopt(TCP_NOPUSH) failed: %m");
110 		}
111 #endif
112 	}
113 
114 	if (!fgets(line, sizeof(line), stdin))
115 		exit(1);
116 
117 	if (logging) {
118 		char *t;
119 		char *end;
120 
121 		end = memchr(line, 0, sizeof(line));
122 		if (end == NULL) {
123 			if ((t = malloc(sizeof(line) + 1)) == NULL)
124 				logerr("malloc: %s", strerror(errno));
125 			memcpy(t, line, sizeof(line));
126 			t[sizeof(line)] = 0;
127 		} else {
128 			if ((t = strdup(line)) == NULL)
129 				logerr("strdup: %s", strerror(errno));
130 		}
131 		for (end = t; *end; end++)
132 			if (*end == '\n' || *end == '\r')
133 				*end = ' ';
134 		sval = sizeof(ss);
135 		if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0)
136 			logerr("getpeername: %s", strerror(errno));
137 		realhostname_sa(rhost, sizeof rhost - 1,
138 				(struct sockaddr *)&ss, sval);
139 		rhost[sizeof(rhost) - 1] = '\0';
140 		syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t);
141 	}
142 
143 	comp = &av[1];
144 	av[2] = "--";
145 	for (lp = line, ap = &av[3];;) {
146 		*ap = strtok(lp, " \t\r\n");
147 		if (!*ap) {
148 			if (secure && ap == &av[3]) {
149 				puts("must provide username\r\n");
150 				exit(1);
151 			}
152 			break;
153 		}
154 		if (secure && strchr(*ap, '@')) {
155 			puts("forwarding service denied\r\n");
156 			exit(1);
157 		}
158 
159 		/* RFC742: "/[Ww]" == "-l" */
160 		if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
161 			av[1] = "-l";
162 			comp = &av[0];
163 		}
164 		else if (++ap == av + ENTRIES)
165 			break;
166 		lp = NULL;
167 	}
168 
169 	if (lp = strrchr(prog, '/'))
170 		*comp = ++lp;
171 	else
172 		*comp = prog;
173 	if (pipe(p) < 0)
174 		logerr("pipe: %s", strerror(errno));
175 
176 	switch(vfork()) {
177 	case 0:
178 		(void)close(p[0]);
179 		if (p[1] != 1) {
180 			(void)dup2(p[1], 1);
181 			(void)close(p[1]);
182 		}
183 		execv(prog, comp);
184 		logerr("execv: %s: %s", prog, strerror(errno));
185 		_exit(1);
186 	case -1:
187 		logerr("fork: %s", strerror(errno));
188 	}
189 	(void)close(p[1]);
190 	if (!(fp = fdopen(p[0], "r")))
191 		logerr("fdopen: %s", strerror(errno));
192 	while ((ch = getc(fp)) != EOF) {
193 		if (ch == '\n')
194 			putchar('\r');
195 		putchar(ch);
196 	}
197 	exit(0);
198 }
199 
200 #if __STDC__
201 #include <stdarg.h>
202 #else
203 #include <varargs.h>
204 #endif
205 
206 void
207 #if __STDC__
208 logerr(const char *fmt, ...)
209 #else
210 logerr(fmt, va_alist)
211 	char *fmt;
212         va_dcl
213 #endif
214 {
215 	va_list ap;
216 #if __STDC__
217 	va_start(ap, fmt);
218 #else
219 	va_start(ap);
220 #endif
221 	(void)vsyslog(LOG_ERR, fmt, ap);
222 	va_end(ap);
223 	exit(1);
224 	/* NOTREACHED */
225 }
226