process.c revision 1.6
1 /* $NetBSD: process.c,v 1.6 1998/07/04 19:31:05 mrg 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 #if 0 39 static char sccsid[] = "@(#)process.c 8.2 (Berkeley) 11/16/93"; 40 #else 41 __RCSID("$NetBSD: process.c,v 1.6 1998/07/04 19:31:05 mrg Exp $"); 42 #endif 43 #endif /* not lint */ 44 45 /* 46 * process.c handles the requests, which can be of three types: 47 * ANNOUNCE - announce to a user that a talk is wanted 48 * LEAVE_INVITE - insert the request into the table 49 * LOOK_UP - look up to see if a request is waiting in 50 * in the table for the local user 51 * DELETE - delete invitation 52 */ 53 54 #include <sys/param.h> 55 #include <sys/stat.h> 56 #include <sys/socket.h> 57 58 #include <netinet/in.h> 59 60 #include <protocols/talkd.h> 61 62 #include <netdb.h> 63 #include <syslog.h> 64 #include <stdio.h> 65 #include <string.h> 66 #include <paths.h> 67 #include <utmp.h> 68 69 #include "extern.h" 70 71 void 72 process_request(mp, rp) 73 CTL_MSG *mp; 74 CTL_RESPONSE *rp; 75 { 76 CTL_MSG *ptr; 77 78 rp->vers = TALK_VERSION; 79 rp->type = mp->type; 80 rp->id_num = htonl(0); 81 if (mp->vers != TALK_VERSION) { 82 syslog(LOG_WARNING, "Bad protocol version %d", mp->vers); 83 rp->answer = BADVERSION; 84 return; 85 } 86 mp->id_num = ntohl(mp->id_num); 87 mp->addr.sa_family = ntohs(mp->addr.sa_family); 88 if (mp->addr.sa_family != AF_INET) { 89 syslog(LOG_WARNING, "Bad address, family %d", 90 mp->addr.sa_family); 91 rp->answer = BADADDR; 92 return; 93 } 94 mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family); 95 if (mp->ctl_addr.sa_family != AF_INET) { 96 syslog(LOG_WARNING, "Bad control address, family %d", 97 mp->ctl_addr.sa_family); 98 rp->answer = BADCTLADDR; 99 return; 100 } 101 mp->pid = ntohl(mp->pid); 102 if (debug || logging) 103 print_request("request", mp); 104 switch (mp->type) { 105 106 case ANNOUNCE: 107 do_announce(mp, rp); 108 break; 109 110 case LEAVE_INVITE: 111 ptr = find_request(mp); 112 if (ptr != (CTL_MSG *)0) { 113 rp->id_num = htonl(ptr->id_num); 114 rp->answer = SUCCESS; 115 } else 116 insert_table(mp, rp); 117 break; 118 119 case LOOK_UP: 120 ptr = find_match(mp); 121 if (ptr != (CTL_MSG *)0) { 122 rp->id_num = htonl(ptr->id_num); 123 rp->addr = ptr->addr; 124 rp->addr.sa_family = htons(ptr->addr.sa_family); 125 rp->answer = SUCCESS; 126 } else 127 rp->answer = NOT_HERE; 128 break; 129 130 case DELETE: 131 rp->answer = delete_invite(mp->id_num); 132 break; 133 134 default: 135 rp->answer = UNKNOWN_REQUEST; 136 break; 137 } 138 if (debug) 139 print_response("process_request done", rp); 140 } 141 142 void 143 do_announce(mp, rp) 144 CTL_MSG *mp; 145 CTL_RESPONSE *rp; 146 { 147 struct hostent *hp; 148 CTL_MSG *ptr; 149 int result; 150 151 /* see if the user is logged */ 152 result = find_user(mp->r_name, mp->r_tty); 153 if (result != SUCCESS) { 154 rp->answer = result; 155 return; 156 } 157 #define satosin(sa) ((struct sockaddr_in *)(sa)) 158 hp = gethostbyaddr((char *)&satosin(&mp->ctl_addr)->sin_addr, 159 sizeof (struct in_addr), AF_INET); 160 if (hp == (struct hostent *)0) { 161 rp->answer = MACHINE_UNKNOWN; 162 return; 163 } 164 ptr = find_request(mp); 165 if (ptr == (CTL_MSG *) 0) { 166 insert_table(mp, rp); 167 rp->answer = announce(mp, hp->h_name); 168 return; 169 } 170 if (mp->id_num > ptr->id_num) { 171 /* 172 * This is an explicit re-announce, so update the id_num 173 * field to avoid duplicates and re-announce the talk. 174 */ 175 ptr->id_num = new_id(); 176 rp->id_num = htonl(ptr->id_num); 177 rp->answer = announce(mp, hp->h_name); 178 } else { 179 /* a duplicated request, so ignore it */ 180 rp->id_num = htonl(ptr->id_num); 181 rp->answer = SUCCESS; 182 } 183 } 184 185 /* 186 * Search utmp for the local user 187 */ 188 int 189 find_user(name, tty) 190 char *name, *tty; 191 { 192 struct utmp ubuf; 193 int status; 194 FILE *fd; 195 struct stat statb; 196 char line[sizeof(ubuf.ut_line) + 1]; 197 char ftty[sizeof(_PATH_DEV) - 1 + sizeof(line)]; 198 time_t atime = 0; 199 int anytty = 0; 200 201 if ((fd = fopen(_PATH_UTMP, "r")) == NULL) { 202 fprintf(stderr, "talkd: can't read %s.\n", _PATH_UTMP); 203 return (FAILED); 204 } 205 #define SCMPN(a, b) strncmp(a, b, sizeof (a)) 206 status = NOT_HERE; 207 (void) strcpy(ftty, _PATH_DEV); 208 209 if (*tty == '\0') 210 anytty = 1; 211 212 while (fread((char *) &ubuf, sizeof ubuf, 1, fd) == 1) { 213 if (SCMPN(ubuf.ut_name, name) != 0) 214 continue; 215 (void)strncpy(line, ubuf.ut_line, sizeof(ubuf.ut_line)); 216 line[sizeof(ubuf.ut_line)] = '\0'; 217 if (anytty) { 218 /* no particular tty was requested */ 219 /* XXX strcpy is safe */ 220 (void)strcpy(ftty + sizeof(_PATH_DEV) - 1, line); 221 if (stat(ftty, &statb) == 0) { 222 if (!(statb.st_mode & S_IWGRP)) { 223 if (status != SUCCESS) 224 status = PERMISSION_DENIED; 225 continue; 226 } 227 if (statb.st_atime > atime) { 228 atime = statb.st_atime; 229 (void)strcpy(tty, line); 230 status = SUCCESS; 231 } 232 } 233 } else if (strcmp(line, tty) == 0) { 234 status = SUCCESS; 235 break; 236 } 237 } 238 (void)fclose(fd); 239 return (status); 240 } 241
Indexes created Thu Sep 25 16:09:42 GMT 2025