1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #ifndef lint 33 #if 0 34 static char sccsid[] = "@(#)process.c 8.2 (Berkeley) 11/16/93"; 35 #endif 36 static const char rcsid[] = 37 "$FreeBSD$"; 38 #endif /* not lint */ 39 40 /* 41 * process.c handles the requests, which can be of three types: 42 * ANNOUNCE - announce to a user that a talk is wanted 43 * LEAVE_INVITE - insert the request into the table 44 * LOOK_UP - look up to see if a request is waiting in 45 * in the table for the local user 46 * DELETE - delete invitation 47 */ 48 #include <sys/param.h> 49 #include <sys/stat.h> 50 #include <sys/socket.h> 51 #include <netinet/in.h> 52 #include <protocols/talkd.h> 53 #include <ctype.h> 54 #include <err.h> 55 #include <netdb.h> 56 #include <paths.h> 57 #include <stdio.h> 58 #include <string.h> 59 #include <syslog.h> 60 #include <utmpx.h> 61 62 #include "extern.h" 63 64 void 65 process_request(CTL_MSG *mp, CTL_RESPONSE *rp) 66 { 67 CTL_MSG *ptr; 68 char *s; 69 70 rp->vers = TALK_VERSION; 71 rp->type = mp->type; 72 rp->id_num = htonl(0); 73 if (mp->vers != TALK_VERSION) { 74 syslog(LOG_WARNING, "bad protocol version %d", mp->vers); 75 rp->answer = BADVERSION; 76 return; 77 } 78 mp->id_num = ntohl(mp->id_num); 79 mp->addr.sa_family = ntohs(mp->addr.sa_family); 80 if (mp->addr.sa_family != AF_INET) { 81 syslog(LOG_WARNING, "bad address, family %d", 82 mp->addr.sa_family); 83 rp->answer = BADADDR; 84 return; 85 } 86 mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family); 87 if (mp->ctl_addr.sa_family != AF_INET) { 88 syslog(LOG_WARNING, "bad control address, family %d", 89 mp->ctl_addr.sa_family); 90 rp->answer = BADCTLADDR; 91 return; 92 } 93 for (s = mp->l_name; *s; s++) 94 if (!isprint(*s)) { 95 syslog(LOG_NOTICE, "illegal user name. Aborting"); 96 rp->answer = FAILED; 97 return; 98 } 99 mp->pid = ntohl(mp->pid); 100 if (debug) 101 print_request("process_request", mp); 102 switch (mp->type) { 103 104 case ANNOUNCE: 105 do_announce(mp, rp); 106 break; 107 108 case LEAVE_INVITE: 109 ptr = find_request(mp); 110 if (ptr != (CTL_MSG *)0) { 111 rp->id_num = htonl(ptr->id_num); 112 rp->answer = SUCCESS; 113 } else 114 insert_table(mp, rp); 115 break; 116 117 case LOOK_UP: 118 ptr = find_match(mp); 119 if (ptr != (CTL_MSG *)0) { 120 rp->id_num = htonl(ptr->id_num); 121 rp->addr = ptr->addr; 122 rp->addr.sa_family = htons(ptr->addr.sa_family); 123 rp->answer = SUCCESS; 124 } else 125 rp->answer = NOT_HERE; 126 break; 127 128 case DELETE: 129 rp->answer = delete_invite(mp->id_num); 130 break; 131 132 default: 133 rp->answer = UNKNOWN_REQUEST; 134 break; 135 } 136 if (debug) 137 print_response("process_request", rp); 138 } 139 140 void 141 do_announce(CTL_MSG *mp, CTL_RESPONSE *rp) 142 { 143 struct hostent *hp; 144 CTL_MSG *ptr; 145 int result; 146 147 /* see if the user is logged */ 148 result = find_user(mp->r_name, mp->r_tty); 149 if (result != SUCCESS) { 150 rp->answer = result; 151 return; 152 } 153 #define satosin(sa) ((struct sockaddr_in *)(void *)(sa)) 154 hp = gethostbyaddr(&satosin(&mp->ctl_addr)->sin_addr, 155 sizeof (struct in_addr), AF_INET); 156 if (hp == (struct hostent *)0) { 157 rp->answer = MACHINE_UNKNOWN; 158 return; 159 } 160 ptr = find_request(mp); 161 if (ptr == (CTL_MSG *) 0) { 162 insert_table(mp, rp); 163 rp->answer = announce(mp, hp->h_name); 164 return; 165 } 166 if (mp->id_num > ptr->id_num) { 167 /* 168 * This is an explicit re-announce, so update the id_num 169 * field to avoid duplicates and re-announce the talk. 170 */ 171 ptr->id_num = new_id(); 172 rp->id_num = htonl(ptr->id_num); 173 rp->answer = announce(mp, hp->h_name); 174 } else { 175 /* a duplicated request, so ignore it */ 176 rp->id_num = htonl(ptr->id_num); 177 rp->answer = SUCCESS; 178 } 179 } 180 181 /* 182 * Search utmp for the local user 183 */ 184 int 185 find_user(const char *name, char *tty) 186 { 187 struct utmpx *ut; 188 int status; 189 struct stat statb; 190 time_t best = 0; 191 char ftty[sizeof(_PATH_DEV) - 1 + sizeof(ut->ut_line)]; 192 193 setutxent(); 194 status = NOT_HERE; 195 (void) strcpy(ftty, _PATH_DEV); 196 while ((ut = getutxent()) != NULL) 197 if (ut->ut_type == USER_PROCESS && 198 strcmp(ut->ut_user, 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 ut->ut_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, ut->ut_line); 211 status = SUCCESS; 212 continue; 213 } 214 } 215 } 216 if (strcmp(ut->ut_line, tty) == 0) { 217 status = SUCCESS; 218 break; 219 } 220 } 221 endutxent(); 222 return (status); 223 } 224