1 /* $NetBSD: process.c,v 1.12 2007/01/08 17:51:34 christos 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 35 static char sccsid[] = "@(#)process.c 8.2 (Berkeley) 11/16/93"; 36 #else 37 __RCSID("$NetBSD: process.c,v 1.12 2007/01/08 17:51:34 christos 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 68 void 69 process_request(mp, rp) 70 CTL_MSG *mp; 71 CTL_RESPONSE *rp; 72 { 73 CTL_MSG *ptr; 74 75 rp->vers = TALK_VERSION; 76 rp->type = mp->type; 77 rp->id_num = htonl(0); 78 mp->id_num = ntohl(mp->id_num); 79 mp->addr.sa_family = ntohs(mp->addr.sa_family); 80 mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family); 81 mp->pid = ntohl(mp->pid); 82 if (mp->vers != TALK_VERSION) { 83 syslog(LOG_WARNING, "Bad protocol version %d", mp->vers); 84 rp->answer = BADVERSION; 85 return; 86 } 87 if (mp->addr.sa_family != AF_INET) { 88 syslog(LOG_WARNING, "Bad address, family %d", 89 mp->addr.sa_family); 90 rp->answer = BADADDR; 91 return; 92 } 93 if (mp->ctl_addr.sa_family != AF_INET) { 94 syslog(LOG_WARNING, "Bad control address, family %d", 95 mp->ctl_addr.sa_family); 96 rp->answer = BADCTLADDR; 97 return; 98 } 99 if (debug || logging) 100 print_request("request", mp); 101 switch (mp->type) { 102 103 case ANNOUNCE: 104 do_announce(mp, rp); 105 break; 106 107 case LEAVE_INVITE: 108 ptr = find_request(mp); 109 if (ptr != (CTL_MSG *)0) { 110 rp->id_num = htonl(ptr->id_num); 111 rp->answer = SUCCESS; 112 } else 113 insert_table(mp, rp); 114 break; 115 116 case LOOK_UP: 117 ptr = find_match(mp); 118 if (ptr != (CTL_MSG *)0) { 119 rp->id_num = htonl(ptr->id_num); 120 rp->addr = ptr->addr; 121 rp->addr.sa_family = htons(ptr->addr.sa_family); 122 rp->answer = SUCCESS; 123 } else 124 rp->answer = NOT_HERE; 125 break; 126 127 case DELETE: 128 rp->answer = delete_invite(mp->id_num); 129 break; 130 131 default: 132 rp->answer = UNKNOWN_REQUEST; 133 break; 134 } 135 if (debug) 136 print_response("process_request done", rp); 137 } 138 139 void 140 do_announce(mp, rp) 141 CTL_MSG *mp; 142 CTL_RESPONSE *rp; 143 { 144 CTL_MSG *ptr; 145 int result; 146 char hostname[NI_MAXHOST]; 147 struct sockaddr sa; 148 149 tsa2sa(&sa, &mp->ctl_addr); 150 151 /* see if the user is logged */ 152 result = find_user(mp->r_name, mp->r_tty, sizeof(mp->r_tty)); 153 if (result != SUCCESS) { 154 rp->answer = result; 155 return; 156 } 157 if (getnameinfo(&sa, sa.sa_len, hostname, sizeof(hostname), NULL, 158 0, 0)) { 159 rp->answer = MACHINE_UNKNOWN; 160 return; 161 } 162 ptr = find_request(mp); 163 if (ptr == (CTL_MSG *) 0) { 164 insert_table(mp, rp); 165 rp->answer = announce(mp, hostname); 166 return; 167 } 168 if (mp->id_num > ptr->id_num) { 169 /* 170 * This is an explicit re-announce, so update the id_num 171 * field to avoid duplicates and re-announce the talk. 172 */ 173 ptr->id_num = new_id(); 174 rp->id_num = htonl(ptr->id_num); 175 rp->answer = announce(mp, hostname); 176 } else { 177 /* a duplicated request, so ignore it */ 178 rp->id_num = htonl(ptr->id_num); 179 rp->answer = SUCCESS; 180 } 181 } 182 183 /* 184 * Search utmp for the local user 185 */ 186 int 187 find_user(name, tty, ttysize) 188 char *name, *tty; 189 size_t ttysize; 190 { 191 int status; 192 struct stat statb; 193 struct utmpentry *ep; 194 char ftty[sizeof(_PATH_DEV) + sizeof(ep->line)]; 195 time_t atime = 0; 196 int anytty = 0; 197 198 (void)getutentries(NULL, &ep); 199 200 status = NOT_HERE; 201 (void) strlcpy(ftty, _PATH_DEV, sizeof(ftty)); 202 203 if (*tty == '\0') 204 anytty = 1; 205 206 for (; ep; ep = ep->next) { 207 if (strcmp(ep->name, name) != 0) 208 continue; 209 if (anytty) { 210 /* no particular tty was requested */ 211 (void)strlcpy(ftty + sizeof(_PATH_DEV) - 1, ep->line, 212 sizeof(ftty) - sizeof(_PATH_DEV) + 1); 213 if (stat(ftty, &statb) != 0) 214 continue; 215 216 if (!(statb.st_mode & S_IWGRP)) { 217 if (status != SUCCESS) 218 status = PERMISSION_DENIED; 219 continue; 220 } 221 if (statb.st_atime > atime && 222 strlcpy(tty, ep->line, ttysize) < ttysize) { 223 atime = statb.st_atime; 224 status = SUCCESS; 225 } 226 } else if (strcmp(ep->line, tty) == 0) { 227 status = SUCCESS; 228 break; 229 } 230 } 231 return (status); 232 } 233