process.c revision 1.4
1 /* $NetBSD: process.c,v 1.4 1997/06/29 19:13:04 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 1.4 1997/06/29 19:13:04 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 #include "extern.h" 64 65 void 66 process_request(mp, rp) 67 CTL_MSG *mp; 68 CTL_RESPONSE *rp; 69 { 70 CTL_MSG *ptr; 71 extern int debug; 72 73 rp->vers = TALK_VERSION; 74 rp->type = mp->type; 75 rp->id_num = htonl(0); 76 if (mp->vers != TALK_VERSION) { 77 syslog(LOG_WARNING, "Bad protocol version %d", mp->vers); 78 rp->answer = BADVERSION; 79 return; 80 } 81 mp->id_num = ntohl(mp->id_num); 82 mp->addr.sa_family = ntohs(mp->addr.sa_family); 83 if (mp->addr.sa_family != AF_INET) { 84 syslog(LOG_WARNING, "Bad address, family %d", 85 mp->addr.sa_family); 86 rp->answer = BADADDR; 87 return; 88 } 89 mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family); 90 if (mp->ctl_addr.sa_family != AF_INET) { 91 syslog(LOG_WARNING, "Bad control address, family %d", 92 mp->ctl_addr.sa_family); 93 rp->answer = BADCTLADDR; 94 return; 95 } 96 mp->pid = ntohl(mp->pid); 97 if (debug) 98 print_request("process_request", mp); 99 switch (mp->type) { 100 101 case ANNOUNCE: 102 do_announce(mp, rp); 103 break; 104 105 case LEAVE_INVITE: 106 ptr = find_request(mp); 107 if (ptr != (CTL_MSG *)0) { 108 rp->id_num = htonl(ptr->id_num); 109 rp->answer = SUCCESS; 110 } else 111 insert_table(mp, rp); 112 break; 113 114 case LOOK_UP: 115 ptr = find_match(mp); 116 if (ptr != (CTL_MSG *)0) { 117 rp->id_num = htonl(ptr->id_num); 118 rp->addr = ptr->addr; 119 rp->addr.sa_family = htons(ptr->addr.sa_family); 120 rp->answer = SUCCESS; 121 } else 122 rp->answer = NOT_HERE; 123 break; 124 125 case DELETE: 126 rp->answer = delete_invite(mp->id_num); 127 break; 128 129 default: 130 rp->answer = UNKNOWN_REQUEST; 131 break; 132 } 133 if (debug) 134 print_response("process_request", rp); 135 } 136 137 void 138 do_announce(mp, rp) 139 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 int 186 find_user(name, tty) 187 char *name, *tty; 188 { 189 struct utmp ubuf; 190 int status; 191 FILE *fd; 192 struct stat statb; 193 char line[sizeof(ubuf.ut_line) + 1]; 194 char ftty[sizeof(_PATH_DEV) - 1 + sizeof(line)]; 195 time_t atime = 0; 196 int anytty = 0; 197 198 if ((fd = fopen(_PATH_UTMP, "r")) == NULL) { 199 fprintf(stderr, "talkd: can't read %s.\n", _PATH_UTMP); 200 return (FAILED); 201 } 202 #define SCMPN(a, b) strncmp(a, b, sizeof (a)) 203 status = NOT_HERE; 204 (void) strcpy(ftty, _PATH_DEV); 205 206 if (*tty == '\0') 207 anytty = 1; 208 209 while (fread((char *) &ubuf, sizeof ubuf, 1, fd) == 1) { 210 if (SCMPN(ubuf.ut_name, name) != 0) 211 continue; 212 (void)strncpy(line, ubuf.ut_line, sizeof(ubuf.ut_line)); 213 line[sizeof(ubuf.ut_line)] = '\0'; 214 if (anytty) { 215 /* no particular tty was requested */ 216 (void)strcpy(ftty + sizeof(_PATH_DEV) - 1, line); 217 if (stat(ftty, &statb) == 0) { 218 if (!(statb.st_mode & 020)) { 219 if (status != SUCCESS) 220 status = PERMISSION_DENIED; 221 continue; 222 } 223 if (statb.st_atime > atime) { 224 atime = statb.st_atime; 225 (void) strcpy(tty, line); 226 status = SUCCESS; 227 } 228 } 229 } else if (strcmp(line, tty) == 0) { 230 status = SUCCESS; 231 break; 232 } 233 } 234 (void)fclose(fd); 235 return (status); 236 } 237
Indexes created Thu Sep 25 16:09:42 GMT 2025