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
51static void cleanup(int sig);
52static int do_protocol(const char *name, const struct addrinfo *ai);
53static void trying(const struct addrinfo *ai);
54
55void
56netfinger(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
100static int
101do_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
211static void
212trying(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
223static void
224cleanup(int sig __unused)
225{
226#define	ERRSTR	"Timed out.\n"
227	write(STDERR_FILENO, ERRSTR, sizeof ERRSTR);
228	exit(1);
229}
230
231