1/* $NetBSD: process.c,v 1.13 2009/03/16 01:04:32 lukem Exp $ */ 2 3/* 4 * Copyright (c) 1983, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32#include <sys/cdefs.h> 33#ifndef lint 34#if 0 35static char sccsid[] = "@(#)process.c 8.2 (Berkeley) 11/16/93"; 36#else 37__RCSID("$NetBSD: process.c,v 1.13 2009/03/16 01:04:32 lukem Exp $"); 38#endif 39#endif /* not lint */ 40 41/* 42 * process.c handles the requests, which can be of three types: 43 * ANNOUNCE - announce to a user that a talk is wanted 44 * LEAVE_INVITE - insert the request into the table 45 * LOOK_UP - look up to see if a request is waiting in 46 * in the table for the local user 47 * DELETE - delete invitation 48 */ 49 50#include <sys/param.h> 51#include <sys/stat.h> 52#include <sys/socket.h> 53 54#include <netinet/in.h> 55 56#include <protocols/talkd.h> 57 58#include <netdb.h> 59#include <syslog.h> 60#include <stdio.h> 61#include <string.h> 62#include <paths.h> 63 64#include "extern.h" 65 66#include "utmpentry.h" 67 68void 69process_request(CTL_MSG *mp, CTL_RESPONSE *rp) 70{ 71 CTL_MSG *ptr; 72 73 rp->vers = TALK_VERSION; 74 rp->type = mp->type; 75 rp->id_num = htonl(0); 76 mp->id_num = ntohl(mp->id_num); 77 mp->addr.sa_family = ntohs(mp->addr.sa_family); 78 mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family); 79 mp->pid = ntohl(mp->pid); 80 if (mp->vers != TALK_VERSION) { 81 syslog(LOG_WARNING, "Bad protocol version %d", mp->vers); 82 rp->answer = BADVERSION; 83 return; 84 } 85 if (mp->addr.sa_family != AF_INET) { 86 syslog(LOG_WARNING, "Bad address, family %d", 87 mp->addr.sa_family); 88 rp->answer = BADADDR; 89 return; 90 } 91 if (mp->ctl_addr.sa_family != AF_INET) { 92 syslog(LOG_WARNING, "Bad control address, family %d", 93 mp->ctl_addr.sa_family); 94 rp->answer = BADCTLADDR; 95 return; 96 } 97 if (debug || logging) 98 print_request("request", mp); 99 switch (mp->type) { 100 101 case ANNOUNCE: 102 do_announce(mp, rp); 103 break; 104 105 case LEAVE_INVITE: 106 ptr = find_request(mp); 107 if (ptr != (CTL_MSG *)0) { 108 rp->id_num = htonl(ptr->id_num); 109 rp->answer = SUCCESS; 110 } else 111 insert_table(mp, rp); 112 break; 113 114 case LOOK_UP: 115 ptr = find_match(mp); 116 if (ptr != (CTL_MSG *)0) { 117 rp->id_num = htonl(ptr->id_num); 118 rp->addr = ptr->addr; 119 rp->addr.sa_family = htons(ptr->addr.sa_family); 120 rp->answer = SUCCESS; 121 } else 122 rp->answer = NOT_HERE; 123 break; 124 125 case DELETE: 126 rp->answer = delete_invite(mp->id_num); 127 break; 128 129 default: 130 rp->answer = UNKNOWN_REQUEST; 131 break; 132 } 133 if (debug) 134 print_response("process_request done", rp); 135} 136 137void 138do_announce(CTL_MSG *mp, CTL_RESPONSE *rp) 139{ 140 CTL_MSG *ptr; 141 int result; 142 char hostname[NI_MAXHOST]; 143 struct sockaddr sa; 144 145 tsa2sa(&sa, &mp->ctl_addr); 146 147 /* see if the user is logged */ 148 result = find_user(mp->r_name, mp->r_tty, sizeof(mp->r_tty)); 149 if (result != SUCCESS) { 150 rp->answer = result; 151 return; 152 } 153 if (getnameinfo(&sa, sa.sa_len, hostname, sizeof(hostname), NULL, 154 0, 0)) { 155 rp->answer = MACHINE_UNKNOWN; 156 return; 157 } 158 ptr = find_request(mp); 159 if (ptr == (CTL_MSG *) 0) { 160 insert_table(mp, rp); 161 rp->answer = announce(mp, hostname); 162 return; 163 } 164 if (mp->id_num > ptr->id_num) { 165 /* 166 * This is an explicit re-announce, so update the id_num 167 * field to avoid duplicates and re-announce the talk. 168 */ 169 ptr->id_num = new_id(); 170 rp->id_num = htonl(ptr->id_num); 171 rp->answer = announce(mp, hostname); 172 } else { 173 /* a duplicated request, so ignore it */ 174 rp->id_num = htonl(ptr->id_num); 175 rp->answer = SUCCESS; 176 } 177} 178 179/* 180 * Search utmp for the local user 181 */ 182int 183find_user(const char *name, char *tty, size_t ttysize) 184{ 185 int status; 186 struct stat statb; 187 struct utmpentry *ep; 188 char ftty[sizeof(_PATH_DEV) + sizeof(ep->line)]; 189 time_t atime = 0; 190 int anytty = 0; 191 192 (void)getutentries(NULL, &ep); 193 194 status = NOT_HERE; 195 (void) strlcpy(ftty, _PATH_DEV, sizeof(ftty)); 196 197 if (*tty == '\0') 198 anytty = 1; 199 200 for (; ep; ep = ep->next) { 201 if (strcmp(ep->name, name) != 0) 202 continue; 203 if (anytty) { 204 /* no particular tty was requested */ 205 (void)strlcpy(ftty + sizeof(_PATH_DEV) - 1, ep->line, 206 sizeof(ftty) - sizeof(_PATH_DEV) + 1); 207 if (stat(ftty, &statb) != 0) 208 continue; 209 210 if (!(statb.st_mode & S_IWGRP)) { 211 if (status != SUCCESS) 212 status = PERMISSION_DENIED; 213 continue; 214 } 215 if (statb.st_atime > atime && 216 strlcpy(tty, ep->line, ttysize) < ttysize) { 217 atime = statb.st_atime; 218 status = SUCCESS; 219 } 220 } else if (strcmp(ep->line, tty) == 0) { 221 status = SUCCESS; 222 break; 223 } 224 } 225 return (status); 226} 227