diff options
Diffstat (limited to 'libexec/talkd/process.c')
| -rw-r--r-- | libexec/talkd/process.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/libexec/talkd/process.c b/libexec/talkd/process.c new file mode 100644 index 000000000000..39ef14a37be1 --- /dev/null +++ b/libexec/talkd/process.c @@ -0,0 +1,215 @@ +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * 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. 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 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 <sys/param.h> +#include <sys/stat.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <protocols/talkd.h> +#include <ctype.h> +#include <err.h> +#include <netdb.h> +#include <paths.h> +#include <stdio.h> +#include <string.h> +#include <syslog.h> +#include <utmpx.h> + +#include "extern.h" + +void +process_request(CTL_MSG *mp, CTL_RESPONSE *rp) +{ + CTL_MSG *ptr; + 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(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 *)(void *)(sa)) + hp = gethostbyaddr(&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; + } +} + +/* + * Search utmp for the local user + */ +int +find_user(const char *name, char *tty) +{ + struct utmpx *ut; + int status; + struct stat statb; + time_t best = 0; + char ftty[sizeof(_PATH_DEV) - 1 + sizeof(ut->ut_line)]; + + setutxent(); + status = NOT_HERE; + (void) strcpy(ftty, _PATH_DEV); + while ((ut = getutxent()) != NULL) + if (ut->ut_type == USER_PROCESS && + strcmp(ut->ut_user, name) == 0) { + if (*tty == '\0' || best != 0) { + if (best == 0) + status = PERMISSION_DENIED; + /* no particular tty was requested */ + (void) strcpy(ftty + sizeof(_PATH_DEV) - 1, + ut->ut_line); + if (stat(ftty, &statb) == 0) { + if (!(statb.st_mode & 020)) + continue; + if (statb.st_atime > best) { + best = statb.st_atime; + (void) strcpy(tty, ut->ut_line); + status = SUCCESS; + continue; + } + } + } + if (strcmp(ut->ut_line, tty) == 0) { + status = SUCCESS; + break; + } + } + endutxent(); + return (status); +} |