1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1983, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1983, 1993\n\
35 The Regents of the University of California. All rights reserved.\n";
36 #endif /* not lint */
37
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)fingerd.c 8.1 (Berkeley) 6/4/93";
41 #endif
42 static const char rcsid[] =
43 "$FreeBSD$";
44 #endif /* not lint */
45
46 #include <sys/types.h>
47 #include <sys/param.h>
48 #include <sys/socket.h>
49 #include <netinet/in.h>
50 #include <netinet/tcp.h>
51 #include <arpa/inet.h>
52 #include <errno.h>
53
54 #include <unistd.h>
55 #include <syslog.h>
56 #include <libutil.h>
57 #include <netdb.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include "pathnames.h"
62 #ifdef USE_BLACKLIST
63 #include <blacklist.h>
64 #endif
65
66 void logerr(const char *, ...) __printflike(1, 2) __dead2;
67
68 int
main(int argc,char * argv[])69 main(int argc, char *argv[])
70 {
71 FILE *fp;
72 int ch;
73 char *lp;
74 struct sockaddr_storage ss;
75 socklen_t sval;
76 int p[2], debug, kflag, logging, pflag, secure;
77 #define ENTRIES 50
78 char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog;
79 char rhost[MAXHOSTNAMELEN];
80
81 prog = _PATH_FINGER;
82 debug = logging = kflag = pflag = secure = 0;
83 openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON);
84 opterr = 0;
85 while ((ch = getopt(argc, argv, "dklp:s")) != -1)
86 switch (ch) {
87 case 'd':
88 debug = 1;
89 break;
90 case 'k':
91 kflag = 1;
92 break;
93 case 'l':
94 logging = 1;
95 break;
96 case 'p':
97 prog = optarg;
98 pflag = 1;
99 break;
100 case 's':
101 secure = 1;
102 break;
103 case '?':
104 default:
105 logerr("illegal option -- %c", optopt);
106 }
107
108 /*
109 * Enable server-side Transaction TCP.
110 */
111 if (!debug) {
112 int one = 1;
113 if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one,
114 sizeof one) < 0) {
115 logerr("setsockopt(TCP_NOPUSH) failed: %m");
116 }
117 }
118
119 if (!fgets(line, sizeof(line), stdin))
120 exit(1);
121
122 if (!debug && (logging || pflag)) {
123 sval = sizeof(ss);
124 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0)
125 logerr("getpeername: %s", strerror(errno));
126 realhostname_sa(rhost, sizeof rhost - 1,
127 (struct sockaddr *)&ss, sval);
128 rhost[sizeof(rhost) - 1] = '\0';
129 if (pflag)
130 setenv("FINGERD_REMOTE_HOST", rhost, 1);
131 }
132
133 if (logging) {
134 char *t;
135 char *end;
136
137 end = memchr(line, 0, sizeof(line));
138 if (end == NULL) {
139 if ((t = malloc(sizeof(line) + 1)) == NULL)
140 logerr("malloc: %s", strerror(errno));
141 memcpy(t, line, sizeof(line));
142 t[sizeof(line)] = 0;
143 } else {
144 if ((t = strdup(line)) == NULL)
145 logerr("strdup: %s", strerror(errno));
146 }
147 for (end = t; *end; end++)
148 if (*end == '\n' || *end == '\r')
149 *end = ' ';
150 syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t);
151 }
152
153 comp = &av[2];
154 av[3] = "--";
155 if (kflag)
156 *comp-- = "-k";
157 for (lp = line, ap = &av[4];;) {
158 *ap = strtok(lp, " \t\r\n");
159 if (!*ap) {
160 if (secure && ap == &av[4]) {
161 #ifdef USE_BLACKLIST
162 blacklist(1, STDIN_FILENO, "nousername");
163 #endif
164 puts("must provide username\r\n");
165 exit(1);
166 }
167 break;
168 }
169 if (secure && strchr(*ap, '@')) {
170 #ifdef USE_BLACKLIST
171 blacklist(1, STDIN_FILENO, "noforwarding");
172 #endif
173 puts("forwarding service denied\r\n");
174 exit(1);
175 }
176
177 /* RFC742: "/[Ww]" == "-l" */
178 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
179 *comp-- = "-l";
180 }
181 else if (++ap == av + ENTRIES) {
182 *ap = NULL;
183 break;
184 }
185 lp = NULL;
186 }
187
188 if ((lp = strrchr(prog, '/')) != NULL)
189 *comp = ++lp;
190 else
191 *comp = prog;
192 if (pipe(p) < 0)
193 logerr("pipe: %s", strerror(errno));
194
195 if (debug) {
196 fprintf(stderr, "%s", prog);
197 for (ap = comp; *ap != NULL; ++ap)
198 fprintf(stderr, " %s", *ap);
199 fprintf(stderr, "\n");
200 }
201
202 switch(vfork()) {
203 case 0:
204 (void)close(p[0]);
205 if (p[1] != STDOUT_FILENO) {
206 (void)dup2(p[1], STDOUT_FILENO);
207 (void)close(p[1]);
208 }
209 dup2(STDOUT_FILENO, STDERR_FILENO);
210
211 #ifdef USE_BLACKLIST
212 blacklist(0, STDIN_FILENO, "success");
213 #endif
214 execv(prog, comp);
215 write(STDERR_FILENO, prog, strlen(prog));
216 #define MSG ": cannot execute\n"
217 write(STDERR_FILENO, MSG, strlen(MSG));
218 #undef MSG
219 _exit(1);
220 case -1:
221 logerr("fork: %s", strerror(errno));
222 }
223 (void)close(p[1]);
224 if (!(fp = fdopen(p[0], "r")))
225 logerr("fdopen: %s", strerror(errno));
226 while ((ch = getc(fp)) != EOF) {
227 if (ch == '\n')
228 putchar('\r');
229 putchar(ch);
230 }
231 exit(0);
232 }
233
234 #include <stdarg.h>
235
236 void
logerr(const char * fmt,...)237 logerr(const char *fmt, ...)
238 {
239 va_list ap;
240 va_start(ap, fmt);
241 (void)vsyslog(LOG_ERR, fmt, ap);
242 va_end(ap);
243 exit(1);
244 /* NOTREACHED */
245 }
246