xref: /freebsd/libexec/fingerd/fingerd.c (revision 5ebc7e6281887681c3a348a5a4c902e262ccd656)
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 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 static 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 
58 void err __P((const char *, ...));
59 
60 int
61 main(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 	for (lp = line, ap = &av[2];;) {
111 		*ap = strtok(lp, " \t\r\n");
112 		if (!*ap) {
113 			if (secure && ap == &av[2]) {
114 				puts("must provide username\r\n");
115 				exit(1);
116 			}
117 			break;
118 		}
119 		if (secure && strchr(*ap, '@')) {
120 			puts("forwarding service denied\r\n");
121 			exit(1);
122 		}
123 
124 		/* RFC742: "/[Ww]" == "-l" */
125 		if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
126 			av[1] = "-l";
127 			comp = &av[0];
128 		}
129 		else if (++ap == av + ENTRIES)
130 			break;
131 		lp = NULL;
132 	}
133 
134 	if (lp = strrchr(prog, '/'))
135 		*comp = ++lp;
136 	else
137 		*comp = prog;
138 	if (pipe(p) < 0)
139 		err("pipe: %s", strerror(errno));
140 
141 	switch(vfork()) {
142 	case 0:
143 		(void)close(p[0]);
144 		if (p[1] != 1) {
145 			(void)dup2(p[1], 1);
146 			(void)close(p[1]);
147 		}
148 		execv(prog, comp);
149 		err("execv: %s: %s", prog, strerror(errno));
150 		_exit(1);
151 	case -1:
152 		err("fork: %s", strerror(errno));
153 	}
154 	(void)close(p[1]);
155 	if (!(fp = fdopen(p[0], "r")))
156 		err("fdopen: %s", strerror(errno));
157 	while ((ch = getc(fp)) != EOF) {
158 		if (ch == '\n')
159 			putchar('\r');
160 		putchar(ch);
161 	}
162 	exit(0);
163 }
164 
165 #if __STDC__
166 #include <stdarg.h>
167 #else
168 #include <varargs.h>
169 #endif
170 
171 void
172 #if __STDC__
173 err(const char *fmt, ...)
174 #else
175 err(fmt, va_alist)
176 	char *fmt;
177         va_dcl
178 #endif
179 {
180 	va_list ap;
181 #if __STDC__
182 	va_start(ap, fmt);
183 #else
184 	va_start(ap);
185 #endif
186 	(void)vsyslog(LOG_ERR, fmt, ap);
187 	va_end(ap);
188 	exit(1);
189 	/* NOTREACHED */
190 }
191