process.c revision 1.5
1 /* $NetBSD: process.c,v 1.5 1998/07/03 11:54:08 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 1.5 1998/07/03 11:54:08 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 extern int debug; 78 79 rp->vers = TALK_VERSION; 80 rp->type = mp->type; 81 rp->id_num = htonl(0); 82 if (mp->vers != TALK_VERSION) { 83 syslog(LOG_WARNING, "Bad protocol version %d", mp->vers); 84 rp->answer = BADVERSION; 85 return; 86 } 87 mp->id_num = ntohl(mp->id_num); 88 mp->addr.sa_family = ntohs(mp->addr.sa_family); 89 if (mp->addr.sa_family != AF_INET) { 90 syslog(LOG_WARNING, "Bad address, family %d", 91 mp->addr.sa_family); 92 rp->answer = BADADDR; 93 return; 94 } 95 mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family); 96 if (mp->ctl_addr.sa_family != AF_INET) { 97 syslog(LOG_WARNING, "Bad control address, family %d", 98 mp->ctl_addr.sa_family); 99 rp->answer = BADCTLADDR; 100 return; 101 } 102 mp->pid = ntohl(mp->pid); 103 if (debug) 104 print_request("process_request", mp); 105 switch (mp->type) { 106 107 case ANNOUNCE: 108 do_announce(mp, rp); 109 break; 110 111 case LEAVE_INVITE: 112 ptr = find_request(mp); 113 if (ptr != (CTL_MSG *)0) { 114 rp->id_num = htonl(ptr->id_num); 115 rp->answer = SUCCESS; 116 } else 117 insert_table(mp, rp); 118 break; 119 120 case LOOK_UP: 121 ptr = find_match(mp); 122 if (ptr != (CTL_MSG *)0) { 123 rp->id_num = htonl(ptr->id_num); 124 rp->addr = ptr->addr; 125 rp->addr.sa_family = htons(ptr->addr.sa_family); 126 rp->answer = SUCCESS; 127 } else 128 rp->answer = NOT_HERE; 129 break; 130 131 case DELETE: 132 rp->answer = delete_invite(mp->id_num); 133 break; 134 135 default: 136 rp->answer = UNKNOWN_REQUEST; 137 break; 138 } 139 if (debug) 140 print_response("process_request", rp); 141 } 142 143 void 144 do_announce(mp, rp) 145 CTL_MSG *mp; 146 CTL_RESPONSE *rp; 147 { 148 struct hostent *hp; 149 CTL_MSG *ptr; 150 int result; 151 152 /* see if the user is logged */ 153 result = find_user(mp->r_name, mp->r_tty); 154 if (result != SUCCESS) { 155 rp->answer = result; 156 return; 157 } 158 #define satosin(sa) ((struct sockaddr_in *)(sa)) 159 hp = gethostbyaddr((char *)&satosin(&mp->ctl_addr)->sin_addr, 160 sizeof (struct in_addr), AF_INET); 161 if (hp == (struct hostent *)0) { 162 rp->answer = MACHINE_UNKNOWN; 163 return; 164 } 165 ptr = find_request(mp); 166 if (ptr == (CTL_MSG *) 0) { 167 insert_table(mp, rp); 168 rp->answer = announce(mp, hp->h_name); 169 return; 170 } 171 if (mp->id_num > ptr->id_num) { 172 /* 173 * This is an explicit re-announce, so update the id_num 174 * field to avoid duplicates and re-announce the talk. 175 */ 176 ptr->id_num = new_id(); 177 rp->id_num = htonl(ptr->id_num); 178 rp->answer = announce(mp, hp->h_name); 179 } else { 180 /* a duplicated request, so ignore it */ 181 rp->id_num = htonl(ptr->id_num); 182 rp->answer = SUCCESS; 183 } 184 } 185 186 /* 187 * Search utmp for the local user 188 */ 189 int 190 find_user(name, tty) 191 char *name, *tty; 192 { 193 struct utmp ubuf; 194 int status; 195 FILE *fd; 196 struct stat statb; 197 char line[sizeof(ubuf.ut_line) + 1]; 198 char ftty[sizeof(_PATH_DEV) - 1 + sizeof(line)]; 199 time_t atime = 0; 200 int anytty = 0; 201 202 if ((fd = fopen(_PATH_UTMP, "r")) == NULL) { 203 fprintf(stderr, "talkd: can't read %s.\n", _PATH_UTMP); 204 return (FAILED); 205 } 206 #define SCMPN(a, b) strncmp(a, b, sizeof (a)) 207 status = NOT_HERE; 208 (void) strcpy(ftty, _PATH_DEV); 209 210 if (*tty == '\0') 211 anytty = 1; 212 213 while (fread((char *) &ubuf, sizeof ubuf, 1, fd) == 1) { 214 if (SCMPN(ubuf.ut_name, name) != 0) 215 continue; 216 (void)strncpy(line, ubuf.ut_line, sizeof(ubuf.ut_line)); 217 line[sizeof(ubuf.ut_line)] = '\0'; 218 if (anytty) { 219 /* no particular tty was requested */ 220 /* XXX strcpy is safe */ 221 (void)strcpy(ftty + sizeof(_PATH_DEV) - 1, line); 222 if (stat(ftty, &statb) == 0) { 223 if (!(statb.st_mode & S_IWGRP)) { 224 if (status != SUCCESS) 225 status = PERMISSION_DENIED; 226 continue; 227 } 228 if (statb.st_atime > atime) { 229 atime = statb.st_atime; 230 (void)strcpy(tty, line); 231 status = SUCCESS; 232 } 233 } 234 } else if (strcmp(line, tty) == 0) { 235 status = SUCCESS; 236 break; 237 } 238 } 239 (void)fclose(fd); 240 return (status); 241 } 242
Indexes created Thu Sep 25 16:09:42 GMT 2025