xref: /illumos-gate/usr/src/cmd/cmd-inet/usr.sbin/in.talkd/in.talkd.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  *
22  * Copyright 2002 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T
28  * All Rights Reserved.
29  */
30 
31 /*
32  * University Copyright- Copyright (c) 1982, 1986, 1988
33  * The Regents of the University of California.
34  * All Rights Reserved.
35  *
36  * University Acknowledgment- Portions of this document are derived from
37  * software developed by the University of California, Berkeley, and its
38  * contributors.
39  */
40 
41 /*
42  * Invoked by the Internet daemon to handle talk requests
43  * Processes talk requests until MAX_LIFE seconds go by with
44  * no action, then dies.
45  */
46 
47 #include <stdio.h>
48 #include <errno.h>
49 #include <sys/ioctl.h>
50 #include <sys/time.h>
51 #include <sys/systeminfo.h>
52 #include <sys/wait.h>
53 #include <unistd.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include "talkd_impl.h"
57 
58 static CTL_MSG request;
59 static CTL_RESPONSE response;
60 
61 char hostname[HOST_NAME_LENGTH];
62 int debug = 0;
63 
64 static CTL_MSG swapmsg(CTL_MSG req);
65 
66 int
67 main()
68 {
69 	struct sockaddr_in from;
70 	socklen_t from_size = (socklen_t)sizeof (from);
71 	int cc;
72 	int name_length = sizeof (hostname);
73 	fd_set rfds;
74 	struct timeval tv;
75 
76 	(void) sysinfo(SI_HOSTNAME, hostname, name_length);
77 
78 	for (;;) {
79 		tv.tv_sec = MAX_LIFE;
80 		tv.tv_usec = 0;
81 		FD_ZERO(&rfds);
82 		FD_SET(0, &rfds);
83 		if (select(1, &rfds, 0, 0, &tv) <= 0)
84 			return (0);
85 		cc = recvfrom(0, (char *)&request, sizeof (request), 0,
86 		    (struct sockaddr *)&from, &from_size);
87 
88 		if (cc != sizeof (request)) {
89 			if (cc < 0 && errno != EINTR) {
90 				print_error("receive");
91 			}
92 		} else {
93 
94 			if (debug) {
95 				(void) printf("Request received : \n");
96 				(void) print_request(&request);
97 			}
98 
99 			request = swapmsg(request);
100 			process_request(&request, &response);
101 
102 			if (debug) {
103 				(void) printf("Response sent : \n");
104 				print_response(&response);
105 			}
106 
107 			/*
108 			 * Can block here, is this what I want?
109 			 */
110 			cc = sendto(0, (char *)&response, sizeof (response), 0,
111 			    (struct sockaddr *)&request.ctl_addr,
112 			    (socklen_t)sizeof (request.ctl_addr));
113 
114 			if (cc != sizeof (response)) {
115 				print_error("Send");
116 			}
117 		}
118 	}
119 }
120 
121 void
122 print_error(char *string)
123 {
124 	FILE *cons;
125 	char *err_dev = "/dev/console";
126 	char *sys;
127 	pid_t val, pid;
128 
129 	if (debug)
130 		err_dev = "/dev/tty";
131 
132 	if ((sys = strerror(errno)) == (char *)NULL)
133 	    sys = "Unknown error";
134 
135 	/* don't ever open tty's directly, let a child do it */
136 	if ((pid = fork()) == 0) {
137 		cons = fopen(err_dev, "a");
138 		if (cons != NULL) {
139 			(void) fprintf(cons, "Talkd : %s : %s(%d)\n\r", string,
140 			    sys, errno);
141 			(void) fclose(cons);
142 		}
143 		exit(0);
144 	} else {
145 		/* wait for the child process to return */
146 		do {
147 			val = wait(0);
148 			if (val == (pid_t)-1) {
149 				if (errno == EINTR) {
150 					continue;
151 				} else if (errno == ECHILD) {
152 					break;
153 				}
154 			}
155 		} while (val != pid);
156 	}
157 }
158 
159 #define	swapshort(a) (((a << 8) | ((unsigned short) a >> 8)) & 0xffff)
160 #define	swaplong(a) ((swapshort(a) << 16) | (swapshort(((unsigned)a >> 16))))
161 
162 /*
163  * Heuristic to detect if need to swap bytes.
164  */
165 
166 static CTL_MSG
167 swapmsg(CTL_MSG req)
168 {
169 	CTL_MSG swapreq;
170 
171 	if (req.ctl_addr.sin_family == swapshort(AF_INET)) {
172 		swapreq = req;
173 		swapreq.id_num = swaplong(req.id_num);
174 		swapreq.pid = swaplong(req.pid);
175 		swapreq.addr.sin_family = swapshort(req.addr.sin_family);
176 		swapreq.ctl_addr.sin_family =
177 			swapshort(req.ctl_addr.sin_family);
178 		return (swapreq);
179 	} else {
180 		return (req);
181 	}
182 }
183