process.c revision 1.3
1 /* $NetBSD: process.c,v 1.3 1997/06/29 18:01:14 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. 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 1.3 1997/06/29 18:01:14 christos 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 #include <sys/param.h> 54 #include <sys/stat.h> 55 #include <sys/socket.h> 56 #include <netinet/in.h> 57 #include <protocols/talkd.h> 58 #include <netdb.h> 59 #include <syslog.h> 60 #include <stdio.h> 61 #include <string.h> 62 #include <paths.h> 63 64 CTL_MSG *find_request(); 65 CTL_MSG *find_match(); 66 67 process_request(mp, rp) 68 register CTL_MSG *mp; 69 register CTL_RESPONSE *rp; 70 { 71 register CTL_MSG *ptr; 72 extern int debug; 73 74 rp->vers = TALK_VERSION; 75 rp->type = mp->type; 76 rp->id_num = htonl(0); 77 if (mp->vers != TALK_VERSION) { 78 syslog(LOG_WARNING, "Bad protocol version %d", mp->vers); 79 rp->answer = BADVERSION; 80 return; 81 } 82 mp->id_num = ntohl(mp->id_num); 83 mp->addr.sa_family = ntohs(mp->addr.sa_family); 84 if (mp->addr.sa_family != AF_INET) { 85 syslog(LOG_WARNING, "Bad address, family %d", 86 mp->addr.sa_family); 87 rp->answer = BADADDR; 88 return; 89 } 90 mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family); 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 mp->pid = ntohl(mp->pid); 98 if (debug) 99 print_request("process_request", mp); 100 switch (mp->type) { 101 102 case ANNOUNCE: 103 do_announce(mp, rp); 104 break; 105 106 case LEAVE_INVITE: 107 ptr = find_request(mp); 108 if (ptr != (CTL_MSG *)0) { 109 rp->id_num = htonl(ptr->id_num); 110 rp->answer = SUCCESS; 111 } else 112 insert_table(mp, rp); 113 break; 114 115 case LOOK_UP: 116 ptr = find_match(mp); 117 if (ptr != (CTL_MSG *)0) { 118 rp->id_num = htonl(ptr->id_num); 119 rp->addr = ptr->addr; 120 rp->addr.sa_family = htons(ptr->addr.sa_family); 121 rp->answer = SUCCESS; 122 } else 123 rp->answer = NOT_HERE; 124 break; 125 126 case DELETE: 127 rp->answer = delete_invite(mp->id_num); 128 break; 129 130 default: 131 rp->answer = UNKNOWN_REQUEST; 132 break; 133 } 134 if (debug) 135 print_response("process_request", rp); 136 } 137 138 do_announce(mp, rp) 139 register CTL_MSG *mp; 140 CTL_RESPONSE *rp; 141 { 142 struct hostent *hp; 143 CTL_MSG *ptr; 144 int result; 145 146 /* see if the user is logged */ 147 result = find_user(mp->r_name, mp->r_tty); 148 if (result != SUCCESS) { 149 rp->answer = result; 150 return; 151 } 152 #define satosin(sa) ((struct sockaddr_in *)(sa)) 153 hp = gethostbyaddr((char *)&satosin(&mp->ctl_addr)->sin_addr, 154 sizeof (struct in_addr), AF_INET); 155 if (hp == (struct hostent *)0) { 156 rp->answer = MACHINE_UNKNOWN; 157 return; 158 } 159 ptr = find_request(mp); 160 if (ptr == (CTL_MSG *) 0) { 161 insert_table(mp, rp); 162 rp->answer = announce(mp, hp->h_name); 163 return; 164 } 165 if (mp->id_num > ptr->id_num) { 166 /* 167 * This is an explicit re-announce, so update the id_num 168 * field to avoid duplicates and re-announce the talk. 169 */ 170 ptr->id_num = new_id(); 171 rp->id_num = htonl(ptr->id_num); 172 rp->answer = announce(mp, hp->h_name); 173 } else { 174 /* a duplicated request, so ignore it */ 175 rp->id_num = htonl(ptr->id_num); 176 rp->answer = SUCCESS; 177 } 178 } 179 180 #include <utmp.h> 181 182 /* 183 * Search utmp for the local user 184 */ 185 find_user(name, tty) 186 char *name, *tty; 187 { 188 struct utmp ubuf; 189 int status; 190 FILE *fd; 191 struct stat statb; 192 char line[sizeof(ubuf.ut_line) + 1]; 193 char ftty[sizeof(_PATH_DEV) - 1 + sizeof(line)]; 194 195 if ((fd = fopen(_PATH_UTMP, "r")) == NULL) { 196 fprintf(stderr, "talkd: can't read %s.\n", _PATH_UTMP); 197 return (FAILED); 198 } 199 #define SCMPN(a, b) strncmp(a, b, sizeof (a)) 200 status = NOT_HERE; 201 (void) strcpy(ftty, _PATH_DEV); 202 while (fread((char *) &ubuf, sizeof ubuf, 1, fd) == 1) 203 if (SCMPN(ubuf.ut_name, name) == 0) { 204 (void)strncpy(line, ubuf.ut_line, sizeof(ubuf.ut_line)); 205 line[sizeof(ubuf.ut_line)] = '\0'; 206 if (*tty == '\0') { 207 status = PERMISSION_DENIED; 208 /* no particular tty was requested */ 209 (void) strcpy(ftty + sizeof(_PATH_DEV) - 1, 210 line); 211 if (stat(ftty, &statb) == 0) { 212 if (!(statb.st_mode & 020)) 213 continue; 214 (void) strcpy(tty, line); 215 status = SUCCESS; 216 break; 217 } 218 } 219 if (strcmp(line, tty) == 0) { 220 status = SUCCESS; 221 break; 222 } 223 } 224 fclose(fd); 225 return (status); 226 } 227
Indexes created Sat Sep 27 14:09:57 GMT 2025