1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Tony Nardo of the Johns Hopkins University/Applied Physics Lab.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #if 0
36 #ifndef lint
37 static char sccsid[] = "@(#)net.c 8.4 (Berkeley) 4/28/95";
38 #endif
39 #endif
40
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD: stable/12/usr.bin/finger/net.c 326025 2017-11-20 19:49:47Z pfg $");
43
44 #include <sys/param.h>
45 #include <sys/socket.h>
46 #include <sys/uio.h>
47 #include <wctype.h>
48 #include <db.h>
49 #include <err.h>
50 #include <netdb.h>
51 #include <pwd.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 #include <utmpx.h>
57 #include <wchar.h>
58 #include "finger.h"
59
60 static void cleanup(int sig);
61 static int do_protocol(const char *name, const struct addrinfo *ai);
62 static void trying(const struct addrinfo *ai);
63
64 void
netfinger(char * name)65 netfinger(char *name)
66 {
67 int error, multi;
68 char *host;
69 struct addrinfo *ai, *ai0;
70 static struct addrinfo hint;
71
72 host = strrchr(name, '@');
73 if (host == NULL)
74 return;
75 *host++ = '\0';
76 signal(SIGALRM, cleanup);
77 alarm(TIME_LIMIT);
78
79 hint.ai_flags = AI_CANONNAME;
80 hint.ai_family = family;
81 hint.ai_socktype = SOCK_STREAM;
82
83 error = getaddrinfo(host, "finger", &hint, &ai0);
84 if (error) {
85 warnx("%s: %s", host, gai_strerror(error));
86 return;
87 }
88
89 multi = (ai0->ai_next) != 0;
90
91 /* ai_canonname may not be filled in if the user specified an IP. */
92 if (ai0->ai_canonname == 0)
93 printf("[%s]\n", host);
94 else
95 printf("[%s]\n", ai0->ai_canonname);
96
97 for (ai = ai0; ai != NULL; ai = ai->ai_next) {
98 if (multi)
99 trying(ai);
100
101 error = do_protocol(name, ai);
102 if (!error)
103 break;
104 }
105 alarm(0);
106 freeaddrinfo(ai0);
107 }
108
109 static int
do_protocol(const char * name,const struct addrinfo * ai)110 do_protocol(const char *name, const struct addrinfo *ai)
111 {
112 int cnt, line_len, s;
113 FILE *fp;
114 wint_t c, lastc;
115 struct iovec iov[3];
116 struct msghdr msg;
117 static char slash_w[] = "/W ";
118 static char neteol[] = "\r\n";
119
120 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
121 if (s < 0) {
122 warn("socket(%d, %d, %d)", ai->ai_family, ai->ai_socktype,
123 ai->ai_protocol);
124 return -1;
125 }
126
127 msg.msg_name = (void *)ai->ai_addr;
128 msg.msg_namelen = ai->ai_addrlen;
129 msg.msg_iov = iov;
130 msg.msg_iovlen = 0;
131 msg.msg_control = 0;
132 msg.msg_controllen = 0;
133 msg.msg_flags = 0;
134
135 /* -l flag for remote fingerd */
136 if (lflag) {
137 iov[msg.msg_iovlen].iov_base = slash_w;
138 iov[msg.msg_iovlen++].iov_len = 3;
139 }
140 /* send the name followed by <CR><LF> */
141 iov[msg.msg_iovlen].iov_base = strdup(name);
142 iov[msg.msg_iovlen++].iov_len = strlen(name);
143 iov[msg.msg_iovlen].iov_base = neteol;
144 iov[msg.msg_iovlen++].iov_len = 2;
145
146 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0) {
147 warn("connect");
148 close(s);
149 return -1;
150 }
151
152 if (sendmsg(s, &msg, 0) < 0) {
153 warn("sendmsg");
154 close(s);
155 return -1;
156 }
157
158 /*
159 * Read from the remote system; once we're connected, we assume some
160 * data. If none arrives, we hang until the user interrupts.
161 *
162 * If we see a <CR> or a <CR> with the high bit set, treat it as
163 * a newline; if followed by a newline character, only output one
164 * newline.
165 *
166 * Otherwise, all high bits are stripped; if it isn't printable and
167 * it isn't a space, we can simply set the 7th bit. Every ASCII
168 * character with bit 7 set is printable.
169 */
170 lastc = 0;
171 if ((fp = fdopen(s, "r")) != NULL) {
172 cnt = 0;
173 line_len = 0;
174 while ((c = getwc(fp)) != EOF) {
175 if (++cnt > OUTPUT_MAX) {
176 printf("\n\n Output truncated at %d bytes...\n",
177 cnt - 1);
178 break;
179 }
180 if (c == 0x0d) {
181 if (lastc == '\r') /* ^M^M - skip dupes */
182 continue;
183 c = '\n';
184 lastc = '\r';
185 } else {
186 if (!iswprint(c) && !iswspace(c)) {
187 c &= 0x7f;
188 c |= 0x40;
189 }
190 if (lastc != '\r' || c != '\n')
191 lastc = c;
192 else {
193 lastc = '\n';
194 continue;
195 }
196 }
197 putwchar(c);
198 if (c != '\n' && ++line_len > _POSIX2_LINE_MAX) {
199 putchar('\\');
200 putchar('\n');
201 lastc = '\r';
202 }
203 if (lastc == '\n' || lastc == '\r')
204 line_len = 0;
205 }
206 if (ferror(fp)) {
207 /*
208 * Assume that whatever it was set errno...
209 */
210 warn("reading from network");
211 }
212 if (lastc != L'\n')
213 putchar('\n');
214
215 fclose(fp);
216 }
217 return 0;
218 }
219
220 static void
trying(const struct addrinfo * ai)221 trying(const struct addrinfo *ai)
222 {
223 char buf[NI_MAXHOST];
224
225 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, buf, sizeof buf,
226 (char *)0, 0, NI_NUMERICHOST) != 0)
227 return; /* XXX can't happen */
228
229 printf("Trying %s...\n", buf);
230 }
231
232 static void
cleanup(int sig __unused)233 cleanup(int sig __unused)
234 {
235 #define ERRSTR "Timed out.\n"
236 write(STDERR_FILENO, ERRSTR, sizeof ERRSTR);
237 exit(1);
238 }
239
240