4.3BSD-Reno/src/usr.bin/finger/net.c

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Tony Nardo of the Johns Hopkins University/Applied Physics Lab.
 *
 * Redistribution and use in source and binary forms are permitted provided
 * that: (1) source distributions retain this entire copyright notice and
 * comment, and (2) distributions including binaries display the following
 * acknowledgement:  ``This product includes software developed by the
 * University of California, Berkeley and its contributors'' in the
 * documentation or other materials provided with the distribution and in
 * all advertising materials mentioning features or use of this software.
 * Neither the name of the University nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
static char sccsid[] = "@(#)net.c	5.5 (Berkeley) 6/1/90";
#endif /* not lint */

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdio.h>
#include <ctype.h>

netfinger(name)
	char *name;
{
	extern int lflag;
	register FILE *fp;
	register int c, lastc;
	struct in_addr defaddr;
	struct hostent *hp, def;
	struct servent *sp;
	struct sockaddr_in sin;
	int s;
	char *alist[1], *host, *rindex();
	u_long inet_addr();

	if (!(host = rindex(name, '@')))
		return;
	*host++ = NULL;
	if (!(hp = gethostbyname(host))) {
		defaddr.s_addr = inet_addr(host);
		if (defaddr.s_addr == -1) {
			(void)fprintf(stderr,
			    "finger: unknown host: %s\n", host);
			return;
		}
		def.h_name = host;
		def.h_addr_list = alist;
		def.h_addr = (char *)&defaddr;
		def.h_length = sizeof(struct in_addr);
		def.h_addrtype = AF_INET;
		def.h_aliases = 0;
		hp = &def;
	}
	if (!(sp = getservbyname("finger", "tcp"))) {
		(void)fprintf(stderr, "finger: tcp/finger: unknown service\n");
		return;
	}
	sin.sin_family = hp->h_addrtype;
	bcopy(hp->h_addr, (char *)&sin.sin_addr, hp->h_length);
	sin.sin_port = sp->s_port;
	if ((s = socket(hp->h_addrtype, SOCK_STREAM, 0)) < 0) {
		perror("finger: socket");
		return;
	}

	/* have network connection; identify the host connected with */
	(void)printf("[%s]\n", hp->h_name);
	if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
		perror("finger: connect");
		(void)close(s);
		return;
	}

	/* -l flag for remote fingerd  */
	if (lflag)
		write(s, "/W ", 3);
	/* send the name followed by <CR><LF> */
	(void)write(s, name, strlen(name));
	(void)write(s, "\r\n", 2);

	/*
	 * Read from the remote system; once we're connected, we assume some
	 * data.  If none arrives, we hang until the user interrupts.
	 *
	 * If we see a <CR> or a <CR> with the high bit set, treat it as
	 * a newline; if followed by a newline character, only output one
	 * newline.
	 *
	 * Otherwise, all high bits are stripped; if it isn't printable and
	 * it isn't a space, we can simply set the 7th bit.  Every ASCII
	 * character with bit 7 set is printable.
	 */ 
	if (fp = fdopen(s, "r"))
		while ((c = getc(fp)) != EOF) {
			c &= 0x7f;
			if (c == 0x0d) {
				c = '\n';
				lastc = '\r';
			} else {
				if (!isprint(c) && !isspace(c))
					c |= 0x40;
				if (lastc != '\r' || c != '\n')
					lastc = c;
				else {
					lastc = '\n';
					continue;
				}
			}
			putchar(c);
		}
	if (lastc != '\n')
		putchar('\n');
	(void)fclose(fp);
}