xref: /netbsd-src/usr.bin/finger/net.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: net.c,v 1.21 2004/06/03 18:33:57 kleink Exp $	*/
2 
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/cdefs.h>
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)net.c	8.4 (Berkeley) 4/28/95";
39 #else
40 __RCSID("$NetBSD: net.c,v 1.21 2004/06/03 18:33:57 kleink Exp $");
41 #endif
42 #endif /* not lint */
43 
44 #include <sys/types.h>
45 #include <sys/socket.h>
46 
47 #include <netinet/in.h>
48 
49 #include <arpa/inet.h>
50 
51 #include <netdb.h>
52 #include <time.h>
53 #include <db.h>
54 #include <unistd.h>
55 #include <pwd.h>
56 #include <stdio.h>
57 #include <string.h>
58 #include <ctype.h>
59 #include <err.h>
60 
61 #include "utmpentry.h"
62 
63 #include "finger.h"
64 #include "extern.h"
65 
66 void
67 netfinger(name)
68 	char *name;
69 {
70 	FILE *fp;
71 	int c, lastc;
72 	int s;
73 	char *host;
74 	struct addrinfo hints, *res, *res0;
75 	int error;
76 	char *emsg = NULL;
77 
78 	lastc = 0;
79 	if (!(host = strrchr(name, '@')))
80 		return;
81 	*host++ = '\0';
82 	memset(&hints, 0, sizeof(hints));
83 	hints.ai_family = PF_UNSPEC;
84 	hints.ai_socktype = SOCK_STREAM;
85 	hints.ai_flags = AI_CANONNAME;
86 	error = getaddrinfo(host, "finger", &hints, &res0);
87 	if (error) {
88 		warnx("%s: %s", gai_strerror(error), host);
89 		return;
90 	}
91 
92 	s = -1;
93 	for (res = res0; res; res = res->ai_next) {
94 		s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
95 		if (s < 0) {
96 			emsg = "socket";
97 			continue;
98 		}
99 
100 		if (connect(s, res->ai_addr, res->ai_addrlen)) {
101 			close(s);
102 			s = -1;
103 			emsg = "connect";
104 			continue;
105 		}
106 
107 		break;
108 	}
109 	if (s < 0) {
110 		if (emsg != NULL)
111 			warn("%s", emsg);
112 		return;
113 	}
114 
115 	/* have network connection; identify the host connected with */
116 	(void)printf("[%s]\n", res0->ai_canonname ? res0->ai_canonname : host);
117 
118 	/* -l flag for remote fingerd  */
119 	if (lflag)
120 		write(s, "/W ", 3);
121 	/* send the name followed by <CR><LF> */
122 	(void)write(s, name, strlen(name));
123 	(void)write(s, "\r\n", 2);
124 
125 	/*
126 	 * Read from the remote system; once we're connected, we assume some
127 	 * data.  If none arrives, we hang until the user interrupts.
128 	 *
129 	 * If we see a <CR> followed by a newline character, only output
130 	 * one newline.
131 	 *
132 	 * If a character isn't printable and it isn't a space, we strip the
133 	 * 8th bit and set the 7th bit.  Every ASCII character with bit 7 set
134 	 * is printable.
135 	 */
136 	if ((fp = fdopen(s, "r")) != NULL)
137 		while ((c = getc(fp)) != EOF) {
138 			if (c == '\r') {
139 				if (lastc == '\r')	/* ^M^M - skip dupes */
140 					continue;
141 				c = '\n';
142 				lastc = '\r';
143 			} else {
144 				if (!(eightflag || isprint(c) || isspace(c))) {
145 					c &= 0x7f;
146 					c |= 0x40;
147 				}
148 				if (lastc != '\r' || c != '\n')
149 					lastc = c;
150 				else {
151 					lastc = '\n';
152 					continue;
153 				}
154 			}
155 			putchar(c);
156 		}
157 	if (lastc != '\n')
158 		putchar('\n');
159 	(void)fclose(fp);
160 }
161