1 /* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)process.c 8.2 (Berkeley) 11/16/93 34 * $FreeBSD: src/libexec/talkd/process.c,v 1.9 1999/08/28 00:10:16 peter Exp $ 35 */ 36 37 /* 38 * process.c handles the requests, which can be of three types: 39 * ANNOUNCE - announce to a user that a talk is wanted 40 * LEAVE_INVITE - insert the request into the table 41 * LOOK_UP - look up to see if a request is waiting in 42 * in the table for the local user 43 * DELETE - delete invitation 44 */ 45 #include <sys/param.h> 46 #include <sys/stat.h> 47 #include <sys/socket.h> 48 #include <netinet/in.h> 49 #include <protocols/talkd.h> 50 #include <ctype.h> 51 #include <err.h> 52 #include <netdb.h> 53 #include <paths.h> 54 #include <stdio.h> 55 #include <string.h> 56 #include <syslog.h> 57 #include "utmpentry.h" 58 59 #include "extern.h" 60 61 extern int debug; 62 63 void 64 process_request(CTL_MSG *mp, CTL_RESPONSE *rp) 65 { 66 CTL_MSG *ptr; 67 char *s; 68 69 rp->vers = TALK_VERSION; 70 rp->type = mp->type; 71 rp->id_num = htonl(0); 72 if (mp->vers != TALK_VERSION) { 73 syslog(LOG_WARNING, "bad protocol version %d", mp->vers); 74 rp->answer = BADVERSION; 75 return; 76 } 77 mp->id_num = ntohl(mp->id_num); 78 mp->addr.sa_family = ntohs(mp->addr.sa_family); 79 if (mp->addr.sa_family != AF_INET) { 80 syslog(LOG_WARNING, "bad address, family %d", 81 mp->addr.sa_family); 82 rp->answer = BADADDR; 83 return; 84 } 85 mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family); 86 if (mp->ctl_addr.sa_family != AF_INET) { 87 syslog(LOG_WARNING, "bad control address, family %d", 88 mp->ctl_addr.sa_family); 89 rp->answer = BADCTLADDR; 90 return; 91 } 92 for (s = mp->l_name; *s; s++) 93 if (!isprint(*s)) { 94 syslog(LOG_NOTICE, "illegal user name. Aborting"); 95 rp->answer = FAILED; 96 return; 97 } 98 mp->pid = ntohl(mp->pid); 99 if (debug) 100 print_request("process_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 != NULL) { 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 != NULL) { 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", rp); 137 } 138 139 void 140 do_announce(CTL_MSG *mp, 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 *)(void *)(sa)) 153 hp = gethostbyaddr(&satosin(&mp->ctl_addr)->sin_addr, 154 sizeof (struct in_addr), AF_INET); 155 if (hp == NULL) { 156 rp->answer = MACHINE_UNKNOWN; 157 return; 158 } 159 ptr = find_request(mp); 160 if (ptr == NULL) { 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 /* 181 * Search utmp for the local user 182 */ 183 int 184 find_user(const char *name, char *tty) 185 { 186 struct utmpentry *ep; 187 int status; 188 struct stat statb; 189 time_t best = 0; 190 char ftty[sizeof(_PATH_DEV) + sizeof(ep->line)]; 191 192 getutentries(NULL, &ep); 193 194 #define SCMPN(a, b) strncmp(a, b, sizeof (a)) 195 status = NOT_HERE; 196 (void) strcpy(ftty, _PATH_DEV); 197 for (; ep; ep = ep->next) 198 if (SCMPN(ep->name, name) == 0) { 199 if (*tty == '\0' || best != 0) { 200 if (best == 0) 201 status = PERMISSION_DENIED; 202 /* no particular tty was requested */ 203 (void) strcpy(ftty + sizeof(_PATH_DEV) - 1, 204 ep->line); 205 if (stat(ftty, &statb) == 0) { 206 if (!(statb.st_mode & 020)) 207 continue; 208 if (statb.st_atime > best) { 209 best = statb.st_atime; 210 (void) strcpy(tty, ep->line); 211 status = SUCCESS; 212 continue; 213 } 214 } 215 } 216 if (strcmp(ep->line, tty) == 0) { 217 status = SUCCESS; 218 break; 219 } 220 } 221 222 return (status); 223 } 224