1 /*
2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Tony Nardo of the Johns Hopkins University/Applied Physics Lab.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)net.c 8.4 (Berkeley) 4/28/95
33 * $FreeBSD: src/usr.bin/finger/net.c,v 1.12.2.4 2002/12/16 08:41:28 roam Exp $
34 */
35
36 #include <sys/param.h>
37 #include <sys/socket.h>
38 #include <sys/uio.h>
39 #include <ctype.h>
40 #include <db.h>
41 #include <err.h>
42 #include <netdb.h>
43 #include <pwd.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 #include "finger.h"
49
50 static void cleanup(int sig);
51 static int do_protocol(const char *name, const struct addrinfo *ai);
52 static void trying(const struct addrinfo *ai);
53
54 void
netfinger(char * name)55 netfinger(char *name)
56 {
57 int error, multi;
58 char *host;
59 struct addrinfo *ai, *ai0;
60 static struct addrinfo hint;
61
62 host = strrchr(name, '@');
63 if (host == NULL)
64 return;
65 *host++ = '\0';
66 signal(SIGALRM, cleanup);
67 alarm(TIME_LIMIT);
68
69 hint.ai_flags = AI_CANONNAME;
70 hint.ai_family = family;
71 hint.ai_socktype = SOCK_STREAM;
72
73 error = getaddrinfo(host, "finger", &hint, &ai0);
74 if (error) {
75 warnx("%s: %s", host, gai_strerror(error));
76 return;
77 }
78
79 multi = (ai0->ai_next) != 0;
80
81 /* ai_canonname may not be filled in if the user specified an IP. */
82 if (ai0->ai_canonname == 0)
83 printf("[%s]\n", host);
84 else
85 printf("[%s]\n", ai0->ai_canonname);
86
87 for (ai = ai0; ai != NULL; ai = ai->ai_next) {
88 if (multi)
89 trying(ai);
90
91 error = do_protocol(name, ai);
92 if (!error)
93 break;
94 }
95 alarm(0);
96 freeaddrinfo(ai0);
97 }
98
99 static int
do_protocol(const char * name,const struct addrinfo * ai)100 do_protocol(const char *name, const struct addrinfo *ai)
101 {
102 int cnt, line_len, s;
103 FILE *fp;
104 int c, lastc;
105 struct iovec iov[3];
106 struct msghdr msg;
107 static char slash_w[] = "/W ";
108 static char neteol[] = "\r\n";
109
110 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
111 if (s < 0) {
112 warn("socket(%d, %d, %d)", ai->ai_family, ai->ai_socktype,
113 ai->ai_protocol);
114 return -1;
115 }
116
117 msg.msg_name = (void *)ai->ai_addr;
118 msg.msg_namelen = ai->ai_addrlen;
119 msg.msg_iov = iov;
120 msg.msg_iovlen = 0;
121 msg.msg_control = 0;
122 msg.msg_controllen = 0;
123 msg.msg_flags = 0;
124
125 /* -l flag for remote fingerd */
126 if (lflag) {
127 iov[msg.msg_iovlen].iov_base = slash_w;
128 iov[msg.msg_iovlen++].iov_len = 3;
129 }
130 /* send the name followed by <CR><LF> */
131 iov[msg.msg_iovlen].iov_base = strdup(name);
132 iov[msg.msg_iovlen++].iov_len = strlen(name);
133 iov[msg.msg_iovlen].iov_base = neteol;
134 iov[msg.msg_iovlen++].iov_len = 2;
135
136 /*
137 * -T disables data-on-SYN: compatibility option to finger broken
138 * hosts. Also, the implicit-open API is broken on IPv6, so do
139 * the explicit connect there, too.
140 */
141 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0) {
142 warn("connect");
143 close(s);
144 return -1;
145 }
146
147 if (sendmsg(s, &msg, 0) < 0) {
148 warn("sendmsg");
149 close(s);
150 return -1;
151 }
152
153 /*
154 * Read from the remote system; once we're connected, we assume some
155 * data. If none arrives, we hang until the user interrupts.
156 *
157 * If we see a <CR> or a <CR> with the high bit set, treat it as
158 * a newline; if followed by a newline character, only output one
159 * newline.
160 *
161 * Otherwise, all high bits are stripped; if it isn't printable and
162 * it isn't a space, we can simply set the 7th bit. Every ASCII
163 * character with bit 7 set is printable.
164 */
165 lastc = 0;
166 if ((fp = fdopen(s, "r")) != NULL) {
167 cnt = 0;
168 line_len = 0;
169 while ((c = getc(fp)) != EOF) {
170 if (++cnt > OUTPUT_MAX) {
171 printf("\n\n Output truncated at %d bytes...\n",
172 cnt - 1);
173 break;
174 }
175 if (c == 0x0d) {
176 if (lastc == '\r') /* ^M^M - skip dupes */
177 continue;
178 c = '\n';
179 lastc = '\r';
180 } else {
181 if (!(eightflag || isprint(c) || isspace(c))) {
182 c &= 0x7f;
183 c |= 0x40;
184 }
185 if (lastc != '\r' || c != '\n')
186 lastc = c;
187 else {
188 lastc = '\n';
189 continue;
190 }
191 }
192 putchar(c);
193 if (c != '\n' && ++line_len > _POSIX2_LINE_MAX) {
194 putchar('\\');
195 putchar('\n');
196 lastc = '\r';
197 }
198 if (lastc == '\n' || lastc == '\r')
199 line_len = 0;
200 }
201 if (ferror(fp)) {
202 /*
203 * Assume that whatever it was set errno...
204 */
205 warn("reading from network");
206 }
207 if (lastc != '\n')
208 putchar('\n');
209
210 fclose(fp);
211 }
212 return 0;
213 }
214
215 static void
trying(const struct addrinfo * ai)216 trying(const struct addrinfo *ai)
217 {
218 char buf[NI_MAXHOST];
219
220 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, buf, sizeof buf,
221 NULL, 0, NI_NUMERICHOST) != 0)
222 return; /* XXX can't happen */
223
224 printf("Trying %s...\n", buf);
225 }
226
227 void
cleanup(int sig __unused)228 cleanup(int sig __unused)
229 {
230 #define ERRSTR "Timed out.\n"
231 write(STDERR_FILENO, ERRSTR, sizeof ERRSTR);
232 exit(1);
233 }
234
235