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 #include <sys/param.h>
36 #include <sys/socket.h>
37 #include <sys/uio.h>
38 #include <wctype.h>
39 #include <db.h>
40 #include <err.h>
41 #include <netdb.h>
42 #include <pwd.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 #include <utmpx.h>
48 #include <wchar.h>
49 #include "finger.h"
50
51 static void cleanup(int sig);
52 static int do_protocol(const char *name, const struct addrinfo *ai);
53 static void trying(const struct addrinfo *ai);
54
55 void
netfinger(char * name)56 netfinger(char *name)
57 {
58 int error, multi;
59 char *host;
60 struct addrinfo *ai, *ai0;
61 static struct addrinfo hint;
62
63 host = strrchr(name, '@');
64 if (host == NULL)
65 return;
66 *host++ = '\0';
67 signal(SIGALRM, cleanup);
68 alarm(TIME_LIMIT);
69
70 hint.ai_flags = AI_CANONNAME;
71 hint.ai_family = family;
72 hint.ai_socktype = SOCK_STREAM;
73
74 error = getaddrinfo(host, "finger", &hint, &ai0);
75 if (error) {
76 warnx("%s: %s", host, gai_strerror(error));
77 return;
78 }
79
80 multi = (ai0->ai_next) != 0;
81
82 /* ai_canonname may not be filled in if the user specified an IP. */
83 if (ai0->ai_canonname == 0)
84 printf("[%s]\n", host);
85 else
86 printf("[%s]\n", ai0->ai_canonname);
87
88 for (ai = ai0; ai != NULL; ai = ai->ai_next) {
89 if (multi)
90 trying(ai);
91
92 error = do_protocol(name, ai);
93 if (!error)
94 break;
95 }
96 alarm(0);
97 freeaddrinfo(ai0);
98 }
99
100 static int
do_protocol(const char * name,const struct addrinfo * ai)101 do_protocol(const char *name, const struct addrinfo *ai)
102 {
103 int cnt, line_len, s;
104 FILE *fp;
105 wint_t c, lastc;
106 struct iovec iov[3];
107 struct msghdr msg;
108 static char slash_w[] = "/W ";
109 static char neteol[] = "\r\n";
110
111 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
112 if (s < 0) {
113 warn("socket(%d, %d, %d)", ai->ai_family, ai->ai_socktype,
114 ai->ai_protocol);
115 return -1;
116 }
117
118 msg.msg_name = (void *)ai->ai_addr;
119 msg.msg_namelen = ai->ai_addrlen;
120 msg.msg_iov = iov;
121 msg.msg_iovlen = 0;
122 msg.msg_control = 0;
123 msg.msg_controllen = 0;
124 msg.msg_flags = 0;
125
126 /* -l flag for remote fingerd */
127 if (lflag) {
128 iov[msg.msg_iovlen].iov_base = slash_w;
129 iov[msg.msg_iovlen++].iov_len = 3;
130 }
131 /* send the name followed by <CR><LF> */
132 iov[msg.msg_iovlen].iov_base = strdup(name);
133 iov[msg.msg_iovlen++].iov_len = strlen(name);
134 iov[msg.msg_iovlen].iov_base = neteol;
135 iov[msg.msg_iovlen++].iov_len = 2;
136
137 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0) {
138 warn("connect");
139 close(s);
140 return -1;
141 }
142
143 if (sendmsg(s, &msg, 0) < 0) {
144 warn("sendmsg");
145 close(s);
146 return -1;
147 }
148
149 /*
150 * Read from the remote system; once we're connected, we assume some
151 * data. If none arrives, we hang until the user interrupts.
152 *
153 * If we see a <CR> or a <CR> with the high bit set, treat it as
154 * a newline; if followed by a newline character, only output one
155 * newline.
156 *
157 * Otherwise, all high bits are stripped; if it isn't printable and
158 * it isn't a space, we can simply set the 7th bit. Every ASCII
159 * character with bit 7 set is printable.
160 */
161 lastc = 0;
162 if ((fp = fdopen(s, "r")) != NULL) {
163 cnt = 0;
164 line_len = 0;
165 while ((c = getwc(fp)) != EOF) {
166 if (++cnt > OUTPUT_MAX) {
167 printf("\n\n Output truncated at %d bytes...\n",
168 cnt - 1);
169 break;
170 }
171 if (c == 0x0d) {
172 if (lastc == '\r') /* ^M^M - skip dupes */
173 continue;
174 c = '\n';
175 lastc = '\r';
176 } else {
177 if (!iswprint(c) && !iswspace(c)) {
178 c &= 0x7f;
179 c |= 0x40;
180 }
181 if (lastc != '\r' || c != '\n')
182 lastc = c;
183 else {
184 lastc = '\n';
185 continue;
186 }
187 }
188 putwchar(c);
189 if (c != '\n' && ++line_len > _POSIX2_LINE_MAX) {
190 putchar('\\');
191 putchar('\n');
192 lastc = '\r';
193 }
194 if (lastc == '\n' || lastc == '\r')
195 line_len = 0;
196 }
197 if (ferror(fp)) {
198 /*
199 * Assume that whatever it was set errno...
200 */
201 warn("reading from network");
202 }
203 if (lastc != L'\n')
204 putchar('\n');
205
206 fclose(fp);
207 }
208 return 0;
209 }
210
211 static void
trying(const struct addrinfo * ai)212 trying(const struct addrinfo *ai)
213 {
214 char buf[NI_MAXHOST];
215
216 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, buf, sizeof buf,
217 (char *)0, 0, NI_NUMERICHOST) != 0)
218 return; /* XXX can't happen */
219
220 printf("Trying %s...\n", buf);
221 }
222
223 static void
cleanup(int sig __unused)224 cleanup(int sig __unused)
225 {
226 #define ERRSTR "Timed out.\n"
227 write(STDERR_FILENO, ERRSTR, sizeof ERRSTR);
228 exit(1);
229 }
230
231