/* * Copyright (c) 1983, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)process.c 8.2 (Berkeley) 11/16/93 * $FreeBSD: src/libexec/talkd/process.c,v 1.9 1999/08/28 00:10:16 peter Exp $ * $DragonFly: src/libexec/talkd/process.c,v 1.3 2003/11/14 03:54:31 dillon Exp $ */ /* * process.c handles the requests, which can be of three types: * ANNOUNCE - announce to a user that a talk is wanted * LEAVE_INVITE - insert the request into the table * LOOK_UP - look up to see if a request is waiting in * in the table for the local user * DELETE - delete invitation */ #include #include #include #include #include #include #include #include #include #include #include #include int announce (CTL_MSG *, char *); int delete_invite (int); void do_announce (CTL_MSG *, CTL_RESPONSE *); CTL_MSG *find_request(); CTL_MSG *find_match(); int find_user (char *, char *); void insert_table (CTL_MSG *, CTL_RESPONSE *); int new_id (void); void print_request (char *, CTL_MSG *); void print_response (char *, CTL_RESPONSE *); void process_request(mp, rp) register CTL_MSG *mp; register CTL_RESPONSE *rp; { register CTL_MSG *ptr; extern int debug; char *s; rp->vers = TALK_VERSION; rp->type = mp->type; rp->id_num = htonl(0); if (mp->vers != TALK_VERSION) { syslog(LOG_WARNING, "bad protocol version %d", mp->vers); rp->answer = BADVERSION; return; } mp->id_num = ntohl(mp->id_num); mp->addr.sa_family = ntohs(mp->addr.sa_family); if (mp->addr.sa_family != AF_INET) { syslog(LOG_WARNING, "bad address, family %d", mp->addr.sa_family); rp->answer = BADADDR; return; } mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family); if (mp->ctl_addr.sa_family != AF_INET) { syslog(LOG_WARNING, "bad control address, family %d", mp->ctl_addr.sa_family); rp->answer = BADCTLADDR; return; } for (s = mp->l_name; *s; s++) if (!isprint(*s)) { syslog(LOG_NOTICE, "illegal user name. Aborting"); rp->answer = FAILED; return; } mp->pid = ntohl(mp->pid); if (debug) print_request("process_request", mp); switch (mp->type) { case ANNOUNCE: do_announce(mp, rp); break; case LEAVE_INVITE: ptr = find_request(mp); if (ptr != (CTL_MSG *)0) { rp->id_num = htonl(ptr->id_num); rp->answer = SUCCESS; } else insert_table(mp, rp); break; case LOOK_UP: ptr = find_match(mp); if (ptr != (CTL_MSG *)0) { rp->id_num = htonl(ptr->id_num); rp->addr = ptr->addr; rp->addr.sa_family = htons(ptr->addr.sa_family); rp->answer = SUCCESS; } else rp->answer = NOT_HERE; break; case DELETE: rp->answer = delete_invite(mp->id_num); break; default: rp->answer = UNKNOWN_REQUEST; break; } if (debug) print_response("process_request", rp); } void do_announce(mp, rp) register CTL_MSG *mp; CTL_RESPONSE *rp; { struct hostent *hp; CTL_MSG *ptr; int result; /* see if the user is logged */ result = find_user(mp->r_name, mp->r_tty); if (result != SUCCESS) { rp->answer = result; return; } #define satosin(sa) ((struct sockaddr_in *)(sa)) hp = gethostbyaddr((char *)&satosin(&mp->ctl_addr)->sin_addr, sizeof (struct in_addr), AF_INET); if (hp == (struct hostent *)0) { rp->answer = MACHINE_UNKNOWN; return; } ptr = find_request(mp); if (ptr == (CTL_MSG *) 0) { insert_table(mp, rp); rp->answer = announce(mp, hp->h_name); return; } if (mp->id_num > ptr->id_num) { /* * This is an explicit re-announce, so update the id_num * field to avoid duplicates and re-announce the talk. */ ptr->id_num = new_id(); rp->id_num = htonl(ptr->id_num); rp->answer = announce(mp, hp->h_name); } else { /* a duplicated request, so ignore it */ rp->id_num = htonl(ptr->id_num); rp->answer = SUCCESS; } } #include /* * Search utmp for the local user */ int find_user(name, tty) char *name, *tty; { struct utmp ubuf; int status; FILE *fd; struct stat statb; time_t best = 0; char line[sizeof(ubuf.ut_line) + 1]; char ftty[sizeof(_PATH_DEV) - 1 + sizeof(line)]; if ((fd = fopen(_PATH_UTMP, "r")) == NULL) { warnx("can't read %s", _PATH_UTMP); return (FAILED); } #define SCMPN(a, b) strncmp(a, b, sizeof (a)) status = NOT_HERE; (void) strcpy(ftty, _PATH_DEV); while (fread((char *) &ubuf, sizeof ubuf, 1, fd) == 1) if (SCMPN(ubuf.ut_name, name) == 0) { strncpy(line, ubuf.ut_line, sizeof(ubuf.ut_line)); line[sizeof(ubuf.ut_line)] = '\0'; if (*tty == '\0' || best != 0) { if (best == 0) status = PERMISSION_DENIED; /* no particular tty was requested */ (void) strcpy(ftty + sizeof(_PATH_DEV) - 1, line); if (stat(ftty, &statb) == 0) { if (!(statb.st_mode & 020)) continue; if (statb.st_atime > best) { best = statb.st_atime; (void) strcpy(tty, line); status = SUCCESS; continue; } } } if (strcmp(line, tty) == 0) { status = SUCCESS; break; } } fclose(fd); return (status); }