net.c revision 14472 
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#ifndef lint
38static char sccsid[] = "@(#)net.c	8.3 (Berkeley) 1/2/94";
39#endif /* not lint */
40
41#include <sys/types.h>
42#include <sys/socket.h>
43#include <netinet/in.h>
44#include <arpa/inet.h>
45#include <netdb.h>
46#include <db.h>
47#include <unistd.h>
48#include <pwd.h>
49#include <utmp.h>
50#include <stdio.h>
51#include <ctype.h>
52#include <string.h>
53#include <sys/uio.h>
54#include "finger.h"
55
56void
57netfinger(name)
58	char *name;
59{
60	extern int lflag;
61	register FILE *fp;
62	register int c, lastc;
63	struct in_addr defaddr;
64	struct hostent *hp, def;
65	struct servent *sp;
66	struct sockaddr_in sin;
67	int s;
68	char *alist[1], *host;
69	struct iovec iov[3];
70	struct msghdr msg;
71
72	if (!(host = rindex(name, '@')))
73		return;
74	*host++ = NULL;
75	if (isdigit(*host) && (defaddr.s_addr = inet_addr(host)) != -1) {
76		def.h_name = host;
77		def.h_addr_list = alist;
78		def.h_addr = (char *)&defaddr;
79		def.h_length = sizeof(struct in_addr);
80		def.h_addrtype = AF_INET;
81		def.h_aliases = 0;
82		hp = &def;
83	} else if (!(hp = gethostbyname(host))) {
84		(void)fprintf(stderr,
85		    "finger: unknown host: %s\n", host);
86		return;
87	}
88	if (!(sp = getservbyname("finger", "tcp"))) {
89		(void)fprintf(stderr, "finger: tcp/finger: unknown service\n");
90		return;
91	}
92	sin.sin_family = hp->h_addrtype;
93	bcopy(hp->h_addr, (char *)&sin.sin_addr, hp->h_length);
94	sin.sin_port = sp->s_port;
95	if ((s = socket(hp->h_addrtype, SOCK_STREAM, 0)) < 0) {
96		perror("finger: socket");
97		return;
98	}
99
100	/* have network connection; identify the host connected with */
101	(void)printf("[%s]\n", hp->h_name);
102
103	msg.msg_name = (void *)&sin;
104	msg.msg_namelen = sizeof sin;
105	msg.msg_iov = iov;
106	msg.msg_iovlen = 0;
107	msg.msg_control = 0;
108	msg.msg_controllen = 0;
109	msg.msg_flags = MSG_EOF;
110
111	/* -l flag for remote fingerd  */
112	if (lflag) {
113		iov[msg.msg_iovlen].iov_base = "/W ";
114		iov[msg.msg_iovlen++].iov_len = 3;
115	}
116	/* send the name followed by <CR><LF> */
117	iov[msg.msg_iovlen].iov_base = name;
118	iov[msg.msg_iovlen++].iov_len = strlen(name);
119	iov[msg.msg_iovlen].iov_base = "\r\n";
120	iov[msg.msg_iovlen++].iov_len = 2;
121
122	if (sendmsg(s, &msg, MSG_EOF) < 0) {
123		perror("finger: sendmsg");
124		close(s);
125		return;
126	}
127
128	/*
129	 * Read from the remote system; once we're connected, we assume some
130	 * data.  If none arrives, we hang until the user interrupts.
131	 *
132	 * If we see a <CR> or a <CR> with the high bit set, treat it as
133	 * a newline; if followed by a newline character, only output one
134	 * newline.
135	 *
136	 * Otherwise, all high bits are stripped; if it isn't printable and
137	 * it isn't a space, we can simply set the 7th bit.  Every ASCII
138	 * character with bit 7 set is printable.
139	 */
140	if (fp = fdopen(s, "r")) {
141		int lastc = '\n';
142
143		while ((c = getc(fp)) != EOF) {
144			if (c == 0x0d) {
145				if (lastc == '\r')	/* ^M^M - skip dupes */
146					continue;
147				c = '\n';
148				lastc = '\r';
149			} else {
150				if (!isprint(c) && !isspace(c)) {
151					c &= 0x7f;
152					c |= 0x40;
153				}
154				if (lastc != '\r' || c != '\n')
155					lastc = c;
156				else {
157					lastc = '\n';
158					continue;
159				}
160			}
161			putchar(c);
162		}
163		if (lastc != '\n')
164			putchar('\n');
165
166		if (ferror(fp)) {
167			/*
168			 * Assume that whatever it was set errno...
169			 */
170			perror("finger: read");
171		}
172		(void)fclose(fp);
173	}
174}
175