1 /* $NetBSD: process.c,v 1.11 2004/10/01 12:27:09 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 1.11 2004/10/01 12:27:09 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 struct hostent *hp; 145 CTL_MSG *ptr; 146 int result; 147 148 /* see if the user is logged */ 149 result = find_user(mp->r_name, mp->r_tty, sizeof(mp->r_tty)); 150 if (result != SUCCESS) { 151 rp->answer = result; 152 return; 153 } 154 #define satosin(sa) ((struct sockaddr_in *)(sa)) 155 hp = gethostbyaddr((char *)&satosin(&mp->ctl_addr)->sin_addr, 156 sizeof (struct in_addr), AF_INET); 157 if (hp == (struct hostent *)0) { 158 rp->answer = MACHINE_UNKNOWN; 159 return; 160 } 161 ptr = find_request(mp); 162 if (ptr == (CTL_MSG *) 0) { 163 insert_table(mp, rp); 164 rp->answer = announce(mp, hp->h_name); 165 return; 166 } 167 if (mp->id_num > ptr->id_num) { 168 /* 169 * This is an explicit re-announce, so update the id_num 170 * field to avoid duplicates and re-announce the talk. 171 */ 172 ptr->id_num = new_id(); 173 rp->id_num = htonl(ptr->id_num); 174 rp->answer = announce(mp, hp->h_name); 175 } else { 176 /* a duplicated request, so ignore it */ 177 rp->id_num = htonl(ptr->id_num); 178 rp->answer = SUCCESS; 179 } 180 } 181 182 /* 183 * Search utmp for the local user 184 */ 185 int 186 find_user(name, tty, ttysize) 187 char *name, *tty; 188 size_t ttysize; 189 { 190 int status; 191 struct stat statb; 192 struct utmpentry *ep; 193 char ftty[sizeof(_PATH_DEV) + sizeof(ep->line)]; 194 time_t atime = 0; 195 int anytty = 0; 196 197 (void)getutentries(NULL, &ep); 198 199 status = NOT_HERE; 200 (void) strlcpy(ftty, _PATH_DEV, sizeof(ftty)); 201 202 if (*tty == '\0') 203 anytty = 1; 204 205 for (; ep; ep = ep->next) { 206 if (strcmp(ep->name, name) != 0) 207 continue; 208 if (anytty) { 209 /* no particular tty was requested */ 210 (void)strlcpy(ftty + sizeof(_PATH_DEV) - 1, ep->line, 211 sizeof(ftty) - sizeof(_PATH_DEV) + 1); 212 if (stat(ftty, &statb) != 0) 213 continue; 214 215 if (!(statb.st_mode & S_IWGRP)) { 216 if (status != SUCCESS) 217 status = PERMISSION_DENIED; 218 continue; 219 } 220 if (statb.st_atime > atime && 221 strlcpy(tty, ep->line, ttysize) < ttysize) { 222 atime = statb.st_atime; 223 status = SUCCESS; 224 } 225 } else if (strcmp(ep->line, tty) == 0) { 226 status = SUCCESS; 227 break; 228 } 229 } 230 return (status); 231 } 232