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findfor.c
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findfor.c
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/* This program is free software; you can redistribute it
* and/or modify it under the terms of the GNU General
* Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include "all.h"
extern int Max_devices;
extern struct xot_device *Devices;
/*
* Find a xot to handle an incoming call
*
*/
/* xot must be locked before use */
//static
void busy_xot (struct xot *xot) {
++xot->busy;
Printfe(8,xot->lci,"\t\tbusy (%d)\n", xot->busy);
}
struct xot_device *
find_dev_on_ip (struct sockaddr_in *addr) {
struct xot_device *dev;
for (dev = Devices; dev < Devices + Max_devices; ++dev) {
struct sockaddr *a;
for (a = dev->addr; a < dev->addr + dev->max_addr; ++a) {
if (((struct sockaddr_in *)a)->sin_addr.s_addr == addr->sin_addr.s_addr)
return(dev);
//goto found_device;
}
}
return(NULL);
}
int
find_free_xot(struct xot_device *dev) {
int lci;
// Fixme - doesn't allow LCI0 Fix it:
// for (lci = dev->max_xot - 1;lci; --lci) {
for (lci = dev->max_xot - 1;lci > 1; --lci) {
if (!dev->xot [lci]) return(lci);
}
return(-1);
}
struct xot *create_new_xot (int fd, struct sockaddr_in *addr) {
struct xot_device *dev;
struct xot *xot;
int lci;
/* First find the device */
Printf(2,"Call from %s\n", inet_ntoa (addr->sin_addr));
if ( (dev = find_dev_on_ip(addr)) == NULL) {
//Printf(3,"Call from %s\n", inet_ntoa (addr->sin_addr));
//return NULL;
//Printf(6,"Accept it!\n");
dev = Devices;
}
//found_device:
/* Now look for a free lci. Count down like a DCE */
pthread_mutex_lock (&dev->lock);
lci = find_free_xot(dev);
pthread_mutex_unlock (&dev->lock);
if (lci == -1) {
Printf(0,"Too many vc's from %s\n", inet_ntoa (addr->sin_addr));
return NULL;
}
//found_lci:
//found free xot
Printfe(3,lci,"Create new xot.\n");
xot = calloc (sizeof *xot, 1);
xot->device = dev;
xot->sock = fd;
xot->lci = lci;
pthread_mutex_init (&xot->lock, NULL);
dev->xot [lci] = xot;
pthread_mutex_unlock (&dev->lock);
return xot;
}
void
force_clear(int tap,unsigned char *tap_packet) {
//unsigned char *tap_packet = packet - 1;
Printf(5,"fake clear\n");
tap_packet[3] = CLEAR_REQUEST;
tap_packet[4] = 0x05;
tap_packet[5] = 0;
write (tap, tap_packet, 1 + 5);
//dump_packet(tap_packet,6,TO_TAP);
Printf(5,"xotd -> tap %i\n",6);
hex_dump(8,10,tap_packet,6);
}
/*
* Find the xot connection for an outbound packet
*
*/
struct xot *find_xot_for_packet (struct xot_device *dev,unsigned char *packet,int len) {
struct xot *xot;
unsigned char *tap_packet = packet - 1;
int lci = get_lci (packet);
Printfe(6,lci,"\t\tfind xot for packet from tap\n");
//force_clear0(dev->tap,tap_packet);
if (lci == 0) {/* ignore this one, see 6.4 in RFC */
if (packet[2] == RESTART_REQUEST) {
packet [2] = RESTART_CONFIRMATION;
write (dev->tap, packet - 1, 1 + 3);
//dump_packet(packet,4,TO_TAP);
Printfe(6,lci,"xotd -> tap %i\n",4);
hex_dump(8,10,packet,4);
}
Printf(0,"Drop packet, lci=0\n");
return NULL;
}
if (lci >= dev->max_xot) {
Printfe(0,lci,"Bad lci - max %d\n", dev->max_xot);
//goto force_clear;
force_clear(dev->tap,tap_packet);
return(NULL);
}
pthread_mutex_lock (&dev->lock);
if (!(xot = dev->xot [lci])) {
/* Not connected */
switch (packet [2]) {
case CLEAR_CONFIRMATION:
/* discard the message */
pthread_mutex_unlock (&dev->lock);
return NULL;
default:
pthread_mutex_unlock (&dev->lock);
Printfe(0,lci,"no connection and packet not CALL\n");
//goto force_clear;
force_clear(dev->tap,tap_packet);
return(NULL);
case CALL_REQUEST:
break;
/* All is good, make the call */
}
Printfe(5,lci,"\t\tCreate new xot.\n");
xot = dev->xot [lci] = calloc (sizeof *xot, 1);
xot->device = dev;
xot->sock = -1;
xot->lci = lci;
pthread_mutex_init (&xot->lock, NULL);
pthread_mutex_unlock (&dev->lock);
/* Save call packet 'till connected to remote */
if (len > sizeof xot->call) {
len = sizeof xot->call;
}
memcpy (xot->call, packet, len);
xot->head.length = htons (len);
xot->head.version = htons (XOT_VERSION);
/* Create thread for TCP->X.25, it'll make the call */
create_inbound (xot);
return NULL; /* send call after connected */
}
//xot with lci exist
/* DANGER - locked device, then xot - always in that order! */
pthread_mutex_lock (&xot->lock);
pthread_mutex_unlock (&dev->lock);
if (xot->sock == -1) {
/* Not yet connected, only legal thing is CLEAR REQUEST */
xot->cleared = packet [2];
pthread_mutex_unlock (&xot->lock);
return NULL;
}
if (xot->closing) {
/* It's being closed */
pthread_mutex_unlock (&xot->lock);
return NULL;
}
busy_xot (xot);
pthread_mutex_unlock (&xot->lock);
if (packet [2] == CALL_REQUEST) {
Printf(0,"call request on active channel\n");
idle_xot (xot);
//goto force_clear;
force_clear(dev->tap,tap_packet);
return(NULL);
}
xot->cleared = packet [2];
/* Copy GFI, LCI from call packet */
packet [0] = (packet [0] & 0xa0) | (xot->call [0] & 0x3f);
packet [1] = xot->call [1];
return xot;
}