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/*
* 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.
*
* $Id$
*/
#ifndef lint
static char sccsid[] = "@(#)process.c 8.2 (Berkeley) 11/16/93";
#endif /* not lint */
/*
* 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 <netdb.h>
#include <syslog.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <paths.h>
CTL_MSG *find_request();
CTL_MSG *find_match();
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);
}
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 <utmp.h>
/*
* Search utmp for the local user
*/
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) {
fprintf(stderr, "talkd: can't read %s.\n", _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);
}
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