예제 #1
0
void ax25_std_heartbeat_expiry(ax25_cb *ax25)
{
	struct sock *sk=ax25->sk;
	
	if (sk)
		bh_lock_sock(sk);

	switch (ax25->state) {
	case AX25_STATE_0:
		/* Magic here: If we listen() and a new link dies before it
		   is accepted() it isn't 'dead' so doesn't get removed. */
		if (!sk || sock_flag(sk, SOCK_DESTROY) ||
		    (sk->sk_state == TCP_LISTEN &&
		     sock_flag(sk, SOCK_DEAD))) {
			if (sk) {
				sock_hold(sk);
				ax25_destroy_socket(ax25);
				bh_unlock_sock(sk);
				sock_put(sk);
			} else
				ax25_destroy_socket(ax25);
			return;
		}
		break;

	case AX25_STATE_3:
	case AX25_STATE_4:
		/*
		 * Check the state of the receive buffer.
		 */
		if (sk != NULL) {
			if (atomic_read(&sk->sk_rmem_alloc) <
			    (sk->sk_rcvbuf / 2) &&
			    (ax25->condition & AX25_COND_OWN_RX_BUSY)) {
				ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
				ax25->condition &= ~AX25_COND_ACK_PENDING;
				ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
				break;
			}
		}
	}

	if (sk)
		bh_unlock_sock(sk);

	ax25_start_heartbeat(ax25);
}
예제 #2
0
파일: ax25_in.c 프로젝트: robacklin/nxc2620
static int ax25_rcv(struct sk_buff *skb, struct net_device *dev,
	ax25_address *dev_addr, struct packet_type *ptype)
{
	ax25_address src, dest, *next_digi = NULL;
	int type = 0, mine = 0, dama;
	struct sock *make, *sk;
	ax25_digi dp, reverse_dp;
	ax25_cb *ax25;
	ax25_dev *ax25_dev;

	/*
	 *	Process the AX.25/LAPB frame.
	 */

	skb_reset_transport_header(skb);

	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
		kfree_skb(skb);
		return 0;
	}

	/*
	 *	Parse the address header.
	 */

	if (ax25_addr_parse(skb->data, skb->len, &src, &dest, &dp, &type, &dama) == NULL) {
		kfree_skb(skb);
		return 0;
	}

	/*
	 *	Ours perhaps ?
	 */
	if (dp.lastrepeat + 1 < dp.ndigi)		/* Not yet digipeated completely */
		next_digi = &dp.calls[dp.lastrepeat + 1];

	/*
	 *	Pull of the AX.25 headers leaving the CTRL/PID bytes
	 */
	skb_pull(skb, ax25_addr_size(&dp));

	/* For our port addresses ? */
	if (ax25cmp(&dest, dev_addr) == 0 && dp.lastrepeat + 1 == dp.ndigi)
		mine = 1;

	/* Also match on any registered callsign from L3/4 */
	if (!mine && ax25_listen_mine(&dest, dev) && dp.lastrepeat + 1 == dp.ndigi)
		mine = 1;

	/* UI frame - bypass LAPB processing */
	if ((*skb->data & ~0x10) == AX25_UI && dp.lastrepeat + 1 == dp.ndigi) {
		skb_set_transport_header(skb, 2); /* skip control and pid */

		ax25_send_to_raw(&dest, skb, skb->data[1]);

		if (!mine && ax25cmp(&dest, (ax25_address *)dev->broadcast) != 0) {
			kfree_skb(skb);
			return 0;
		}

		/* Now we are pointing at the pid byte */
		switch (skb->data[1]) {
		case AX25_P_IP:
			skb_pull(skb,2);		/* drop PID/CTRL */
			skb_reset_transport_header(skb);
			skb_reset_network_header(skb);
			skb->dev      = dev;
			skb->pkt_type = PACKET_HOST;
			skb->protocol = htons(ETH_P_IP);
			netif_rx(skb);
			break;

		case AX25_P_ARP:
			skb_pull(skb,2);
			skb_reset_transport_header(skb);
			skb_reset_network_header(skb);
			skb->dev      = dev;
			skb->pkt_type = PACKET_HOST;
			skb->protocol = htons(ETH_P_ARP);
			netif_rx(skb);
			break;
		case AX25_P_TEXT:
			/* Now find a suitable dgram socket */
			sk = ax25_get_socket(&dest, &src, SOCK_DGRAM);
			if (sk != NULL) {
				bh_lock_sock(sk);
				if (atomic_read(&sk->sk_rmem_alloc) >=
				    sk->sk_rcvbuf) {
					kfree_skb(skb);
				} else {
					/*
					 *	Remove the control and PID.
					 */
					skb_pull(skb, 2);
					if (sock_queue_rcv_skb(sk, skb) != 0)
						kfree_skb(skb);
				}
				bh_unlock_sock(sk);
				sock_put(sk);
			} else {
				kfree_skb(skb);
			}
			break;

		default:
			kfree_skb(skb);	/* Will scan SOCK_AX25 RAW sockets */
			break;
		}

		return 0;
	}

	/*
	 *	Is connected mode supported on this device ?
	 *	If not, should we DM the incoming frame (except DMs) or
	 *	silently ignore them. For now we stay quiet.
	 */
	if (ax25_dev->values[AX25_VALUES_CONMODE] == 0) {
		kfree_skb(skb);
		return 0;
	}

	/* LAPB */

	/* AX.25 state 1-4 */

	ax25_digi_invert(&dp, &reverse_dp);

	if ((ax25 = ax25_find_cb(&dest, &src, &reverse_dp, dev)) != NULL) {
		/*
		 *	Process the frame. If it is queued up internally it
		 *	returns one otherwise we free it immediately. This
		 *	routine itself wakes the user context layers so we do
		 *	no further work
		 */
		if (ax25_process_rx_frame(ax25, skb, type, dama) == 0)
			kfree_skb(skb);

		ax25_cb_put(ax25);
		return 0;
	}

	/* AX.25 state 0 (disconnected) */

	/* a) received not a SABM(E) */

	if ((*skb->data & ~AX25_PF) != AX25_SABM &&
	    (*skb->data & ~AX25_PF) != AX25_SABME) {
		/*
		 *	Never reply to a DM. Also ignore any connects for
		 *	addresses that are not our interfaces and not a socket.
		 */
		if ((*skb->data & ~AX25_PF) != AX25_DM && mine)
			ax25_return_dm(dev, &src, &dest, &dp);

		kfree_skb(skb);
		return 0;
	}

	/* b) received SABM(E) */

	if (dp.lastrepeat + 1 == dp.ndigi)
		sk = ax25_find_listener(&dest, 0, dev, SOCK_SEQPACKET);
	else
		sk = ax25_find_listener(next_digi, 1, dev, SOCK_SEQPACKET);

	if (sk != NULL) {
		bh_lock_sock(sk);
		if (sk_acceptq_is_full(sk) ||
		    (make = ax25_make_new(sk, ax25_dev)) == NULL) {
			if (mine)
				ax25_return_dm(dev, &src, &dest, &dp);
			kfree_skb(skb);
			bh_unlock_sock(sk);
			sock_put(sk);

			return 0;
		}

		ax25 = ax25_sk(make);
		skb_set_owner_r(skb, make);
		skb_queue_head(&sk->sk_receive_queue, skb);

		make->sk_state = TCP_ESTABLISHED;

		sk->sk_ack_backlog++;
		bh_unlock_sock(sk);
	} else {
		if (!mine) {
			kfree_skb(skb);
			return 0;
		}

		if ((ax25 = ax25_create_cb()) == NULL) {
			ax25_return_dm(dev, &src, &dest, &dp);
			kfree_skb(skb);
			return 0;
		}

		ax25_fillin_cb(ax25, ax25_dev);
	}

	ax25->source_addr = dest;
	ax25->dest_addr   = src;

	/*
	 *	Sort out any digipeated paths.
	 */
	if (dp.ndigi && !ax25->digipeat &&
	    (ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
		kfree_skb(skb);
		ax25_destroy_socket(ax25);
		if (sk)
			sock_put(sk);
		return 0;
	}

	if (dp.ndigi == 0) {
		kfree(ax25->digipeat);
		ax25->digipeat = NULL;
	} else {
		/* Reverse the source SABM's path */
		memcpy(ax25->digipeat, &reverse_dp, sizeof(ax25_digi));
	}

	if ((*skb->data & ~AX25_PF) == AX25_SABME) {
		ax25->modulus = AX25_EMODULUS;
		ax25->window  = ax25_dev->values[AX25_VALUES_EWINDOW];
	} else {
		ax25->modulus = AX25_MODULUS;
		ax25->window  = ax25_dev->values[AX25_VALUES_WINDOW];
	}

	ax25_send_control(ax25, AX25_UA, AX25_POLLON, AX25_RESPONSE);

#ifdef CONFIG_AX25_DAMA_SLAVE
	if (dama && ax25->ax25_dev->values[AX25_VALUES_PROTOCOL] == AX25_PROTO_DAMA_SLAVE)
		ax25_dama_on(ax25);
#endif

	ax25->state = AX25_STATE_3;

	ax25_cb_add(ax25);

	ax25_start_heartbeat(ax25);
	ax25_start_t3timer(ax25);
	ax25_start_idletimer(ax25);

	if (sk) {
		if (!sock_flag(sk, SOCK_DEAD))
			sk->sk_data_ready(sk, skb->len);
		sock_put(sk);
	} else
		kfree_skb(skb);

	return 0;
}
예제 #3
0
/*
 *	AX.25 TIMER 
 *
 *	This routine is called every 500ms. Decrement timer by this
 *	amount - if expired then process the event.
 */
static void ax25_timer(unsigned long param)
{
	ax25_cb *ax25 = (ax25_cb *)param;

	switch (ax25->state) {
		case AX25_STATE_0:
			/* Magic here: If we listen() and a new link dies before it
			   is accepted() it isn't 'dead' so doesn't get removed. */
			if (ax25->sk == NULL || ax25->sk->destroy || (ax25->sk->state == TCP_LISTEN && ax25->sk->dead)) {
				del_timer(&ax25->timer);
				ax25_destroy_socket(ax25);
				return;
			}
			break;

		case AX25_STATE_3:
		case AX25_STATE_4:
			/*
			 * Check the state of the receive buffer.
			 */
			if (ax25->sk != NULL) {
				if (ax25->sk->rmem_alloc < (ax25->sk->rcvbuf / 2) && (ax25->condition & OWN_RX_BUSY_CONDITION)) {
					ax25->condition &= ~OWN_RX_BUSY_CONDITION;
					if (!ax25->dama_slave)
						ax25_send_control(ax25, RR, POLLOFF, C_RESPONSE);
					ax25->condition &= ~ACK_PENDING_CONDITION;
					break;
				}
			}
			/*
			 * Check for frames to transmit.
			 */
			if (!ax25->dama_slave)
				ax25_kick(ax25);
			break;

		default:
			break;
	}

	if (ax25->t2timer > 0 && --ax25->t2timer == 0) {
		if (ax25->state == AX25_STATE_3 || ax25->state == AX25_STATE_4) {
			if (ax25->condition & ACK_PENDING_CONDITION) {
				ax25->condition &= ~ACK_PENDING_CONDITION;
				if (!ax25->dama_slave)
					ax25_timeout_response(ax25);
			}
		}
	}

	if (ax25->t3timer > 0 && --ax25->t3timer == 0) {
		/* dl1bke 960114: T3 expires and we are in DAMA mode:  */
		/*                send a DISC and abort the connection */
		if (ax25->dama_slave) {
#ifdef CONFIG_NETROM
			nr_link_failed(&ax25->dest_addr, ax25->device);
#endif
			ax25_clear_queues(ax25);
			ax25_send_control(ax25, DISC, POLLON, C_COMMAND);
				
			ax25->state = AX25_STATE_0;
			if (ax25->sk != NULL) {
				if (ax25->sk->debug)
					printk("T3 Timeout\n");
				ax25->sk->state = TCP_CLOSE;
				ax25->sk->err   = ETIMEDOUT;
				if (!ax25->sk->dead)
					ax25->sk->state_change(ax25->sk);
				ax25->sk->dead  = 1;
			}

			ax25_reset_timer(ax25);
			return;
		}
		
		if (ax25->state == AX25_STATE_3) {
			ax25->n2count = 0;
			ax25_transmit_enquiry(ax25);
			ax25->state   = AX25_STATE_4;
		}
		ax25->t3timer = ax25->t3;
	}
	
	if (ax25->idletimer > 0 && --ax25->idletimer == 0) {
		/* dl1bke 960228: close the connection when IDLE expires */
		/* 		  similar to DAMA T3 timeout but with    */
		/* 		  a "clean" disconnect of the connection */

		ax25_clear_queues(ax25);

		ax25->n2count = 0;
		if (!ax25->dama_slave) {
			ax25->t3timer = 0;
			ax25_send_control(ax25, DISC, POLLON, C_COMMAND);
		} else {
			ax25->t3timer = ax25->t3;
		}
		
		/* state 1 or 2 should not happen, but... */
		
		if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2)
			ax25->state = AX25_STATE_0;
		else
			ax25->state = AX25_STATE_2;

		ax25->t1timer = ax25->t1 = ax25_calculate_t1(ax25);

		if (ax25->sk != NULL) {
			ax25->sk->state = TCP_CLOSE;
			ax25->sk->err = 0;
			if (!ax25->sk->dead)
				ax25->sk->state_change(ax25->sk);
			ax25->sk->dead = 1;
			ax25->sk->destroy = 1;
		}
	}
		                                                                                                                                                                                                                                                                                                                                        
	/* dl1bke 960114: DAMA T1 timeouts are handled in ax25_dama_slave_transmit */
	/* 		  nevertheless we have to re-enqueue the timer struct...   */
	
	if (ax25->t1timer == 0 || --ax25->t1timer > 0) {
		ax25_reset_timer(ax25);
		return;
	}

	if (!ax25_dev_is_dama_slave(ax25->device)) {
		if (ax25->dama_slave)
			ax25->dama_slave = 0;
		ax25_t1_timeout(ax25);
	}
}