xref: /freebsd/usr.bin/finger/net.c (revision df7f5d4de4592a8948a25ce01e5bddfbb7ce39dc)
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
38 static char sccsid[] = "@(#)net.c	8.4 (Berkeley) 4/28/95";
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 
56 void
57 netfinger(name)
58 	char *name;
59 {
60 	extern int lflag;
61 	extern int Tflag;
62 	register FILE *fp;
63 	register int c, lastc;
64 	struct in_addr defaddr;
65 	struct hostent *hp, def;
66 	struct servent *sp;
67 	struct sockaddr_in sin;
68 	int s;
69 	char *alist[1], *host;
70 	struct iovec iov[3];
71 	struct msghdr msg;
72 
73 	if (!(host = rindex(name, '@')))
74 		return;
75 	*host++ = NULL;
76 	if (isdigit(*host) && (defaddr.s_addr = inet_addr(host)) != -1) {
77 		def.h_name = host;
78 		def.h_addr_list = alist;
79 		def.h_addr = (char *)&defaddr;
80 		def.h_length = sizeof(struct in_addr);
81 		def.h_addrtype = AF_INET;
82 		def.h_aliases = 0;
83 		hp = &def;
84 	} else if (!(hp = gethostbyname(host))) {
85 		(void)fprintf(stderr,
86 		    "finger: unknown host: %s\n", host);
87 		return;
88 	}
89 	if (!(sp = getservbyname("finger", "tcp"))) {
90 		(void)fprintf(stderr, "finger: tcp/finger: unknown service\n");
91 		return;
92 	}
93 	sin.sin_family = hp->h_addrtype;
94 	bcopy(hp->h_addr, (char *)&sin.sin_addr, hp->h_length);
95 	sin.sin_port = sp->s_port;
96 	if ((s = socket(hp->h_addrtype, SOCK_STREAM, 0)) < 0) {
97 		perror("finger: socket");
98 		return;
99 	}
100 
101 	/* have network connection; identify the host connected with */
102 	(void)printf("[%s]\n", hp->h_name);
103 
104 	msg.msg_name = (void *)&sin;
105 	msg.msg_namelen = sizeof sin;
106 	msg.msg_iov = iov;
107 	msg.msg_iovlen = 0;
108 	msg.msg_control = 0;
109 	msg.msg_controllen = 0;
110 	msg.msg_flags = MSG_EOF;
111 
112 	/* -l flag for remote fingerd  */
113 	if (lflag) {
114 		iov[msg.msg_iovlen].iov_base = "/W ";
115 		iov[msg.msg_iovlen++].iov_len = 3;
116 	}
117 	/* send the name followed by <CR><LF> */
118 	iov[msg.msg_iovlen].iov_base = name;
119 	iov[msg.msg_iovlen++].iov_len = strlen(name);
120 	iov[msg.msg_iovlen].iov_base = "\r\n";
121 	iov[msg.msg_iovlen++].iov_len = 2;
122 
123 	/* -T disables T/TCP: compatibility option to finger broken hosts */
124 	if (Tflag && connect(s, (struct sockaddr *)&sin, sizeof (sin))) {
125 		perror("finger: connect");
126 		return;
127 	}
128 
129 	if (sendmsg(s, &msg, MSG_EOF) < 0) {
130 		perror("finger: sendmsg");
131 		close(s);
132 		return;
133 	}
134 
135 	/*
136 	 * Read from the remote system; once we're connected, we assume some
137 	 * data.  If none arrives, we hang until the user interrupts.
138 	 *
139 	 * If we see a <CR> or a <CR> with the high bit set, treat it as
140 	 * a newline; if followed by a newline character, only output one
141 	 * newline.
142 	 *
143 	 * Otherwise, all high bits are stripped; if it isn't printable and
144 	 * it isn't a space, we can simply set the 7th bit.  Every ASCII
145 	 * character with bit 7 set is printable.
146 	 */
147 	lastc = 0;
148 	if ((fp = fdopen(s, "r")) != NULL) {
149 		while ((c = getc(fp)) != EOF) {
150 			if (c == 0x0d) {
151 				if (lastc == '\r')	/* ^M^M - skip dupes */
152 					continue;
153 				c = '\n';
154 				lastc = '\r';
155 			} else {
156 				if (!isprint(c) && !isspace(c)) {
157 					c &= 0x7f;
158 					c |= 0x40;
159 				}
160 				if (lastc != '\r' || c != '\n')
161 					lastc = c;
162 				else {
163 					lastc = '\n';
164 					continue;
165 				}
166 			}
167 			putchar(c);
168 		}
169 		if (lastc != '\n')
170 			putchar('\n');
171 
172 		if (ferror(fp)) {
173 			/*
174 			 * Assume that whatever it was set errno...
175 			 */
176 			perror("finger: read");
177 		}
178 		(void)fclose(fp);
179 	}
180 }
181