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. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#if 0
38#ifndef lint
39static char sccsid[] = "@(#)net.c	8.4 (Berkeley) 4/28/95";
40#endif
41#endif
42
43#include <sys/cdefs.h>
44__FBSDID("$FreeBSD: src/usr.bin/finger/net.c,v 1.23 2004/05/16 22:08:15 stefanf Exp $");
45
46#include <sys/param.h>
47#include <sys/socket.h>
48#include <sys/uio.h>
49#include <ctype.h>
50#include <db.h>
51#include <err.h>
52#include <netdb.h>
53#include <pwd.h>
54#include <stdio.h>
55#include <stdlib.h>
56#include <string.h>
57#include <unistd.h>
58#include <utmpx.h>
59#include "finger.h"
60
61static void cleanup(int sig);
62static int do_protocol(const char *name, const struct addrinfo *ai);
63static void trying(const struct addrinfo *ai);
64
65void
66netfinger(char *name)
67{
68	int error, multi;
69	char *host;
70	struct addrinfo *ai, *ai0;
71	static struct addrinfo hint;
72
73	host = strrchr(name, '@');
74	if (host == 0)
75		return;
76	*host++ = '\0';
77	signal(SIGALRM, cleanup);
78	alarm(TIME_LIMIT);
79
80	hint.ai_flags = AI_CANONNAME;
81	hint.ai_family = family;
82	hint.ai_socktype = SOCK_STREAM;
83
84	error = getaddrinfo(host, "finger", &hint, &ai0);
85	if (error) {
86		warnx("%s: %s", host, gai_strerror(error));
87		return;
88	}
89
90	multi = (ai0->ai_next) != 0;
91
92	/* ai_canonname may not be filled in if the user specified an IP. */
93	if (ai0->ai_canonname == 0)
94		printf("[%s]\n", host);
95	else
96		printf("[%s]\n", ai0->ai_canonname);
97
98	for (ai = ai0; ai != 0; ai = ai->ai_next) {
99		if (multi)
100			trying(ai);
101
102		error = do_protocol(name, ai);
103		if (!error)
104			break;
105	}
106	alarm(0);
107	freeaddrinfo(ai0);
108}
109
110static int
111do_protocol(const char *name, const struct addrinfo *ai)
112{
113	int cnt, line_len, s;
114	FILE *fp;
115	int c, lastc;
116	struct iovec iov[3];
117	struct msghdr msg;
118	static char slash_w[] = "/W ";
119	static char neteol[] = "\r\n";
120
121	s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
122	if (s < 0) {
123		warn("socket(%d, %d, %d)", ai->ai_family, ai->ai_socktype,
124		     ai->ai_protocol);
125		return -1;
126	}
127
128	msg.msg_name = (void *)ai->ai_addr;
129	msg.msg_namelen = ai->ai_addrlen;
130	msg.msg_iov = iov;
131	msg.msg_iovlen = 0;
132	msg.msg_control = 0;
133	msg.msg_controllen = 0;
134	msg.msg_flags = 0;
135
136	/* -l flag for remote fingerd  */
137	if (lflag) {
138		iov[msg.msg_iovlen].iov_base = slash_w;
139		iov[msg.msg_iovlen++].iov_len = 3;
140	}
141	/* send the name followed by <CR><LF> */
142	iov[msg.msg_iovlen].iov_base = strdup(name);
143	iov[msg.msg_iovlen++].iov_len = strlen(name);
144	iov[msg.msg_iovlen].iov_base = neteol;
145	iov[msg.msg_iovlen++].iov_len = 2;
146
147#ifdef __APPLE__
148	if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0) {
149#else
150	/*
151	 * -T disables data-on-SYN: compatibility option to finger broken
152	 * hosts.  Also, the implicit-open API is broken on IPv6, so do
153	 * the explicit connect there, too.
154	 */
155	if ((Tflag || ai->ai_addr->sa_family == AF_INET6)
156	    && connect(s, ai->ai_addr, ai->ai_addrlen) < 0) {
157#endif
158		warn("connect");
159		close(s);
160		return -1;
161	}
162
163	if (sendmsg(s, &msg, 0) < 0) {
164		warn("sendmsg");
165		close(s);
166		return -1;
167	}
168
169	/*
170	 * Read from the remote system; once we're connected, we assume some
171	 * data.  If none arrives, we hang until the user interrupts.
172	 *
173	 * If we see a <CR> or a <CR> with the high bit set, treat it as
174	 * a newline; if followed by a newline character, only output one
175	 * newline.
176	 *
177	 * Otherwise, all high bits are stripped; if it isn't printable and
178	 * it isn't a space, we can simply set the 7th bit.  Every ASCII
179	 * character with bit 7 set is printable.
180	 */
181	lastc = 0;
182	if ((fp = fdopen(s, "r")) != NULL) {
183		cnt = 0;
184		line_len = 0;
185		while ((c = getc(fp)) != EOF) {
186			if (++cnt > OUTPUT_MAX) {
187				printf("\n\n Output truncated at %d bytes...\n",
188					cnt - 1);
189				break;
190			}
191			if (c == 0x0d) {
192				if (lastc == '\r')	/* ^M^M - skip dupes */
193					continue;
194				c = '\n';
195				lastc = '\r';
196			} else {
197				if (!isprint(c) && !isspace(c)) {
198					c &= 0x7f;
199					c |= 0x40;
200				}
201				if (lastc != '\r' || c != '\n')
202					lastc = c;
203				else {
204					lastc = '\n';
205					continue;
206				}
207			}
208			putchar(c);
209			if (c != '\n' && ++line_len > _POSIX2_LINE_MAX) {
210				putchar('\\');
211				putchar('\n');
212				lastc = '\r';
213			}
214			if (lastc == '\n' || lastc == '\r')
215				line_len = 0;
216		}
217		if (ferror(fp)) {
218			/*
219			 * Assume that whatever it was set errno...
220			 */
221			warn("reading from network");
222		}
223		if (lastc != '\n')
224			putchar('\n');
225
226		fclose(fp);
227	}
228	return 0;
229}
230
231static void
232trying(const struct addrinfo *ai)
233{
234	char buf[NI_MAXHOST];
235
236	if (getnameinfo(ai->ai_addr, ai->ai_addrlen, buf, sizeof buf,
237			(char *)0, 0, NI_NUMERICHOST) != 0)
238		return;		/* XXX can't happen */
239
240	printf("Trying %s...\n", buf);
241}
242
243void
244cleanup(int sig __unused)
245{
246#define	ERRSTR	"Timed out.\n"
247	write(STDERR_FILENO, ERRSTR, sizeof ERRSTR);
248	exit(1);
249}
250
251