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 #endif /* not lint */
43
44 #include <sys/types.h>
45 #include <sys/param.h>
46 #include <sys/socket.h>
47 #include <netinet/in.h>
48 #include <netinet/tcp.h>
49 #include <arpa/inet.h>
50 #include <errno.h>
51
52 #include <unistd.h>
53 #include <syslog.h>
54 #include <libutil.h>
55 #include <netdb.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include "pathnames.h"
60 #ifdef USE_BLACKLIST
61 #include <blacklist.h>
62 #endif
63
64 void logerr(const char *, ...) __printflike(1, 2) __dead2;
65
66 int
main(int argc,char * argv[])67 main(int argc, char *argv[])
68 {
69 FILE *fp;
70 int ch;
71 char *lp;
72 struct sockaddr_storage ss;
73 socklen_t sval;
74 int p[2], debug, kflag, logging, pflag, secure;
75 #define ENTRIES 50
76 char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog;
77 char rhost[MAXHOSTNAMELEN];
78
79 prog = _PATH_FINGER;
80 debug = logging = kflag = pflag = secure = 0;
81 openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON);
82 opterr = 0;
83 while ((ch = getopt(argc, argv, "dklp:s")) != -1)
84 switch (ch) {
85 case 'd':
86 debug = 1;
87 break;
88 case 'k':
89 kflag = 1;
90 break;
91 case 'l':
92 logging = 1;
93 break;
94 case 'p':
95 prog = optarg;
96 pflag = 1;
97 break;
98 case 's':
99 secure = 1;
100 break;
101 case '?':
102 default:
103 logerr("illegal option -- %c", optopt);
104 }
105
106 /*
107 * Enable server-side Transaction TCP.
108 */
109 if (!debug) {
110 int one = 1;
111 if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one,
112 sizeof one) < 0) {
113 logerr("setsockopt(TCP_NOPUSH) failed: %m");
114 }
115 }
116
117 if (!fgets(line, sizeof(line), stdin))
118 exit(1);
119
120 if (!debug && (logging || pflag)) {
121 sval = sizeof(ss);
122 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0)
123 logerr("getpeername: %s", strerror(errno));
124 realhostname_sa(rhost, sizeof rhost - 1,
125 (struct sockaddr *)&ss, sval);
126 rhost[sizeof(rhost) - 1] = '\0';
127 if (pflag)
128 setenv("FINGERD_REMOTE_HOST", rhost, 1);
129 }
130
131 if (logging) {
132 char *t;
133 char *end;
134
135 end = memchr(line, 0, sizeof(line));
136 if (end == NULL) {
137 if ((t = malloc(sizeof(line) + 1)) == NULL)
138 logerr("malloc: %s", strerror(errno));
139 memcpy(t, line, sizeof(line));
140 t[sizeof(line)] = 0;
141 } else {
142 if ((t = strdup(line)) == NULL)
143 logerr("strdup: %s", strerror(errno));
144 }
145 for (end = t; *end; end++)
146 if (*end == '\n' || *end == '\r')
147 *end = ' ';
148 syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t);
149 }
150
151 comp = &av[2];
152 av[3] = "--";
153 if (kflag)
154 *comp-- = "-k";
155 for (lp = line, ap = &av[4];;) {
156 *ap = strtok(lp, " \t\r\n");
157 if (!*ap) {
158 if (secure && ap == &av[4]) {
159 #ifdef USE_BLACKLIST
160 blacklist(1, STDIN_FILENO, "nousername");
161 #endif
162 puts("must provide username\r\n");
163 exit(1);
164 }
165 break;
166 }
167 if (secure && strchr(*ap, '@')) {
168 #ifdef USE_BLACKLIST
169 blacklist(1, STDIN_FILENO, "noforwarding");
170 #endif
171 puts("forwarding service denied\r\n");
172 exit(1);
173 }
174
175 /* RFC742: "/[Ww]" == "-l" */
176 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
177 *comp-- = "-l";
178 }
179 else if (++ap == av + ENTRIES) {
180 *ap = NULL;
181 break;
182 }
183 lp = NULL;
184 }
185
186 if ((lp = strrchr(prog, '/')) != NULL)
187 *comp = ++lp;
188 else
189 *comp = prog;
190 if (pipe(p) < 0)
191 logerr("pipe: %s", strerror(errno));
192
193 if (debug) {
194 fprintf(stderr, "%s", prog);
195 for (ap = comp; *ap != NULL; ++ap)
196 fprintf(stderr, " %s", *ap);
197 fprintf(stderr, "\n");
198 }
199
200 switch(vfork()) {
201 case 0:
202 (void)close(p[0]);
203 if (p[1] != STDOUT_FILENO) {
204 (void)dup2(p[1], STDOUT_FILENO);
205 (void)close(p[1]);
206 }
207 dup2(STDOUT_FILENO, STDERR_FILENO);
208
209 #ifdef USE_BLACKLIST
210 blacklist(0, STDIN_FILENO, "success");
211 #endif
212 execv(prog, comp);
213 write(STDERR_FILENO, prog, strlen(prog));
214 #define MSG ": cannot execute\n"
215 write(STDERR_FILENO, MSG, strlen(MSG));
216 #undef MSG
217 _exit(1);
218 case -1:
219 logerr("fork: %s", strerror(errno));
220 }
221 (void)close(p[1]);
222 if (!(fp = fdopen(p[0], "r")))
223 logerr("fdopen: %s", strerror(errno));
224 while ((ch = getc(fp)) != EOF) {
225 if (ch == '\n')
226 putchar('\r');
227 putchar(ch);
228 }
229 exit(0);
230 }
231
232 #include <stdarg.h>
233
234 void
logerr(const char * fmt,...)235 logerr(const char *fmt, ...)
236 {
237 va_list ap;
238 va_start(ap, fmt);
239 (void)vsyslog(LOG_ERR, fmt, ap);
240 va_end(ap);
241 exit(1);
242 /* NOTREACHED */
243 }
244