xref: /openbsd/usr.bin/finger/net.c (revision db3296cf)
1 /*	$OpenBSD: net.c,v 1.9 2003/06/03 02:56:08 millert Exp $	*/
2 
3 /*
4  * Copyright (c) 1989 The Regents of the University of California.
5  * 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 #ifndef lint
36 /*static char sccsid[] = "from: @(#)net.c	5.5 (Berkeley) 6/1/90";*/
37 static char rcsid[] = "$OpenBSD: net.c,v 1.9 2003/06/03 02:56:08 millert Exp $";
38 #endif /* not lint */
39 
40 #include <sys/types.h>
41 #include <sys/socket.h>
42 #include <netinet/in.h>
43 #include <arpa/inet.h>
44 #include <netdb.h>
45 #include <stdio.h>
46 #include <string.h>
47 #include <ctype.h>
48 #include <unistd.h>
49 #include <err.h>
50 #include "finger.h"
51 #include "extern.h"
52 
53 void
54 netfinger(name)
55 	char *name;
56 {
57 	FILE *fp;
58 	int c, lastc;
59 	int s;
60 	char *host;
61 	struct addrinfo hints, *res0, *res;
62 	int error;
63 	char hbuf[NI_MAXHOST];
64 
65 	lastc = 0;
66 	if (!(host = strrchr(name, '@')))
67 		return;
68 	*host++ = '\0';
69 	memset(&hints, 0, sizeof(hints));
70 	hints.ai_family = PF_UNSPEC;
71 	hints.ai_socktype = SOCK_STREAM;
72 	error = getaddrinfo(host, "finger", &hints, &res0);
73 	if (error) {
74 		warnx("%s", gai_strerror(error));
75 		return;
76 	}
77 
78 	s = -1;
79 	for (res = res0; res; res = res->ai_next) {
80 		if ((s = socket(res->ai_family, res->ai_socktype,
81 				res->ai_protocol)) < 0) {
82 			continue;
83 		}
84 		if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
85 			(void)close(s);
86 			s = -1;
87 			continue;
88 		}
89 
90 		break;
91 	}
92 
93 	if (s < 0) {
94 		perror("finger");
95 		freeaddrinfo(res0);
96 		return;
97 	}
98 
99 	/* have network connection; identify the host connected with */
100 	if (getnameinfo(res->ai_addr, res->ai_addrlen, hbuf, sizeof(hbuf),
101 	    NULL, 0, NI_NUMERICHOST) != 0) {
102 		strlcpy(hbuf, "(invalid)", sizeof hbuf);
103 	}
104 	(void)printf("[%s/%s]\n", host, hbuf);
105 
106 	freeaddrinfo(res0);
107 
108 	/* -l flag for remote fingerd  */
109 	if (lflag)
110 		write(s, "/W ", 3);
111 	/* send the name followed by <CR><LF> */
112 	(void)write(s, name, strlen(name));
113 	(void)write(s, "\r\n", 2);
114 
115 	/*
116 	 * Read from the remote system; once we're connected, we assume some
117 	 * data.  If none arrives, we hang until the user interrupts.
118 	 *
119 	 * If we see a <CR> or a <CR> with the high bit set, treat it as
120 	 * a newline; if followed by a newline character, only output one
121 	 * newline.
122 	 *
123 	 * Otherwise, all high bits are stripped; if it isn't printable and
124 	 * it isn't a space, we can simply set the 7th bit.  Every ASCII
125 	 * character with bit 7 set is printable.
126 	 */
127 	if ((fp = fdopen(s, "r")) != NULL)
128 		while ((c = getc(fp)) != EOF) {
129 			c &= 0x7f;
130 			if (c == '\r') {
131 				if (lastc == '\r')
132 					continue;
133 				c = '\n';
134 				lastc = '\r';
135 			} else {
136 				if (!isprint(c) && !isspace(c))
137 					c |= 0x40;
138 				if (lastc != '\r' || c != '\n')
139 					lastc = c;
140 				else {
141 					lastc = '\n';
142 					continue;
143 				}
144 			}
145 			putchar(c);
146 		}
147 	if (lastc != '\n')
148 		putchar('\n');
149 	(void)fclose(fp);
150 }
151