Initial import

1 files changed, 419 insertions, 0 deletions

diff --git a/net/x25/x25_in.c b/net/x25/x25_in.c
new file mode 100644
index 000000000..7ac50098a
--- /dev/null
+++ b/net/x25/x25_in.c
@@ -0,0 +1,419 @@
+/*
+ *	X.25 Packet Layer release 002
+ *
+ *	This is ALPHA test software. This code may break your machine,
+ *	randomly fail to work with new releases, misbehave and/or generally
+ *	screw up. It might even work.
+ *
+ *	This code REQUIRES 2.1.15 or higher
+ *
+ *	This module:
+ *		This module 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.
+ *
+ *	History
+ *	X.25 001	Jonathan Naylor	  Started coding.
+ *	X.25 002	Jonathan Naylor	  Centralised disconnection code.
+ *					  New timer architecture.
+ *	2000-03-20	Daniela Squassoni Disabling/enabling of facilities
+ *					  negotiation.
+ *	2000-11-10	Henner Eisen	  Check and reset for out-of-sequence
+ *					  i-frames.
+ */
+
+#define pr_fmt(fmt) "X25: " fmt
+
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/tcp_states.h>
+#include <net/x25.h>
+
+static int x25_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more)
+{
+	struct sk_buff *skbo, *skbn = skb;
+	struct x25_sock *x25 = x25_sk(sk);
+
+	if (more) {
+		x25->fraglen += skb->len;
+		skb_queue_tail(&x25->fragment_queue, skb);
+		skb_set_owner_r(skb, sk);
+		return 0;
+	}
+
+	if (!more && x25->fraglen > 0) {	/* End of fragment */
+		int len = x25->fraglen + skb->len;
+
+		if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL){
+			kfree_skb(skb);
+			return 1;
+		}
+
+		skb_queue_tail(&x25->fragment_queue, skb);
+
+		skb_reset_transport_header(skbn);
+
+		skbo = skb_dequeue(&x25->fragment_queue);
+		skb_copy_from_linear_data(skbo, skb_put(skbn, skbo->len),
+					  skbo->len);
+		kfree_skb(skbo);
+
+		while ((skbo =
+			skb_dequeue(&x25->fragment_queue)) != NULL) {
+			skb_pull(skbo, (x25->neighbour->extended) ?
+					X25_EXT_MIN_LEN : X25_STD_MIN_LEN);
+			skb_copy_from_linear_data(skbo,
+						  skb_put(skbn, skbo->len),
+						  skbo->len);
+			kfree_skb(skbo);
+		}
+
+		x25->fraglen = 0;
+	}
+
+	skb_set_owner_r(skbn, sk);
+	skb_queue_tail(&sk->sk_receive_queue, skbn);
+	if (!sock_flag(sk, SOCK_DEAD))
+		sk->sk_data_ready(sk);
+
+	return 0;
+}
+
+/*
+ * State machine for state 1, Awaiting Call Accepted State.
+ * The handling of the timer(s) is in file x25_timer.c.
+ * Handling of state 0 and connection release is in af_x25.c.
+ */
+static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype)
+{
+	struct x25_address source_addr, dest_addr;
+	int len;
+	struct x25_sock *x25 = x25_sk(sk);
+
+	switch (frametype) {
+	case X25_CALL_ACCEPTED: {
+
+		x25_stop_timer(sk);
+		x25->condition = 0x00;
+		x25->vs        = 0;
+		x25->va        = 0;
+		x25->vr        = 0;
+		x25->vl        = 0;
+		x25->state     = X25_STATE_3;
+		sk->sk_state   = TCP_ESTABLISHED;
+		/*
+		 *	Parse the data in the frame.
+		 */
+		if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
+			goto out_clear;
+		skb_pull(skb, X25_STD_MIN_LEN);
+
+		len = x25_parse_address_block(skb, &source_addr,
+					      &dest_addr);
+		if (len > 0)
+			skb_pull(skb, len);
+		else if (len < 0)
+			goto out_clear;
+
+		len = x25_parse_facilities(skb, &x25->facilities,
+					   &x25->dte_facilities,
+					   &x25->vc_facil_mask);
+		if (len > 0)
+			skb_pull(skb, len);
+		else if (len < 0)
+			goto out_clear;
+		/*
+		 *	Copy any Call User Data.
+		 */
+		if (skb->len > 0) {
+			if (skb->len > X25_MAX_CUD_LEN)
+				goto out_clear;
+
+			skb_copy_bits(skb, 0, x25->calluserdata.cuddata,
+				skb->len);
+			x25->calluserdata.cudlength = skb->len;
+		}
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk->sk_state_change(sk);
+		break;
+	}
+	case X25_CLEAR_REQUEST:
+		if (!pskb_may_pull(skb, X25_STD_MIN_LEN + 2))
+			goto out_clear;
+
+		x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
+		x25_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]);
+		break;
+
+	default:
+		break;
+	}
+
+	return 0;
+
+out_clear:
+	x25_write_internal(sk, X25_CLEAR_REQUEST);
+	x25->state = X25_STATE_2;
+	x25_start_t23timer(sk);
+	return 0;
+}
+
+/*
+ * State machine for state 2, Awaiting Clear Confirmation State.
+ * The handling of the timer(s) is in file x25_timer.c
+ * Handling of state 0 and connection release is in af_x25.c.
+ */
+static int x25_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype)
+{
+	switch (frametype) {
+
+		case X25_CLEAR_REQUEST:
+			if (!pskb_may_pull(skb, X25_STD_MIN_LEN + 2))
+				goto out_clear;
+
+			x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
+			x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
+			break;
+
+		case X25_CLEAR_CONFIRMATION:
+			x25_disconnect(sk, 0, 0, 0);
+			break;
+
+		default:
+			break;
+	}
+
+	return 0;
+
+out_clear:
+	x25_write_internal(sk, X25_CLEAR_REQUEST);
+	x25_start_t23timer(sk);
+	return 0;
+}
+
+/*
+ * State machine for state 3, Connected State.
+ * The handling of the timer(s) is in file x25_timer.c
+ * Handling of state 0 and connection release is in af_x25.c.
+ */
+static int x25_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m)
+{
+	int queued = 0;
+	int modulus;
+	struct x25_sock *x25 = x25_sk(sk);
+
+	modulus = (x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS;
+
+	switch (frametype) {
+
+		case X25_RESET_REQUEST:
+			x25_write_internal(sk, X25_RESET_CONFIRMATION);
+			x25_stop_timer(sk);
+			x25->condition = 0x00;
+			x25->vs        = 0;
+			x25->vr        = 0;
+			x25->va        = 0;
+			x25->vl        = 0;
+			x25_requeue_frames(sk);
+			break;
+
+		case X25_CLEAR_REQUEST:
+			if (!pskb_may_pull(skb, X25_STD_MIN_LEN + 2))
+				goto out_clear;
+
+			x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
+			x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
+			break;
+
+		case X25_RR:
+		case X25_RNR:
+			if (!x25_validate_nr(sk, nr)) {
+				x25_clear_queues(sk);
+				x25_write_internal(sk, X25_RESET_REQUEST);
+				x25_start_t22timer(sk);
+				x25->condition = 0x00;
+				x25->vs        = 0;
+				x25->vr        = 0;
+				x25->va        = 0;
+				x25->vl        = 0;
+				x25->state     = X25_STATE_4;
+			} else {
+				x25_frames_acked(sk, nr);
+				if (frametype == X25_RNR) {
+					x25->condition |= X25_COND_PEER_RX_BUSY;
+				} else {
+					x25->condition &= ~X25_COND_PEER_RX_BUSY;
+				}
+			}
+			break;
+
+		case X25_DATA:	/* XXX */
+			x25->condition &= ~X25_COND_PEER_RX_BUSY;
+			if ((ns != x25->vr) || !x25_validate_nr(sk, nr)) {
+				x25_clear_queues(sk);
+				x25_write_internal(sk, X25_RESET_REQUEST);
+				x25_start_t22timer(sk);
+				x25->condition = 0x00;
+				x25->vs        = 0;
+				x25->vr        = 0;
+				x25->va        = 0;
+				x25->vl        = 0;
+				x25->state     = X25_STATE_4;
+				break;
+			}
+			x25_frames_acked(sk, nr);
+			if (ns == x25->vr) {
+				if (x25_queue_rx_frame(sk, skb, m) == 0) {
+					x25->vr = (x25->vr + 1) % modulus;
+					queued = 1;
+				} else {
+					/* Should never happen */
+					x25_clear_queues(sk);
+					x25_write_internal(sk, X25_RESET_REQUEST);
+					x25_start_t22timer(sk);
+					x25->condition = 0x00;
+					x25->vs        = 0;
+					x25->vr        = 0;
+					x25->va        = 0;
+					x25->vl        = 0;
+					x25->state     = X25_STATE_4;
+					break;
+				}
+				if (atomic_read(&sk->sk_rmem_alloc) >
+				    (sk->sk_rcvbuf >> 1))
+					x25->condition |= X25_COND_OWN_RX_BUSY;
+			}
+			/*
+			 *	If the window is full Ack it immediately, else
+			 *	start the holdback timer.
+			 */
+			if (((x25->vl + x25->facilities.winsize_in) % modulus) == x25->vr) {
+				x25->condition &= ~X25_COND_ACK_PENDING;
+				x25_stop_timer(sk);
+				x25_enquiry_response(sk);
+			} else {
+				x25->condition |= X25_COND_ACK_PENDING;
+				x25_start_t2timer(sk);
+			}
+			break;
+
+		case X25_INTERRUPT_CONFIRMATION:
+			clear_bit(X25_INTERRUPT_FLAG, &x25->flags);
+			break;
+
+		case X25_INTERRUPT:
+			if (sock_flag(sk, SOCK_URGINLINE))
+				queued = !sock_queue_rcv_skb(sk, skb);
+			else {
+				skb_set_owner_r(skb, sk);
+				skb_queue_tail(&x25->interrupt_in_queue, skb);
+				queued = 1;
+			}
+			sk_send_sigurg(sk);
+			x25_write_internal(sk, X25_INTERRUPT_CONFIRMATION);
+			break;
+
+		default:
+			pr_warn("unknown %02X in state 3\n", frametype);
+			break;
+	}
+
+	return queued;
+
+out_clear:
+	x25_write_internal(sk, X25_CLEAR_REQUEST);
+	x25->state = X25_STATE_2;
+	x25_start_t23timer(sk);
+	return 0;
+}
+
+/*
+ * State machine for state 4, Awaiting Reset Confirmation State.
+ * The handling of the timer(s) is in file x25_timer.c
+ * Handling of state 0 and connection release is in af_x25.c.
+ */
+static int x25_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype)
+{
+	struct x25_sock *x25 = x25_sk(sk);
+
+	switch (frametype) {
+
+		case X25_RESET_REQUEST:
+			x25_write_internal(sk, X25_RESET_CONFIRMATION);
+		case X25_RESET_CONFIRMATION: {
+			x25_stop_timer(sk);
+			x25->condition = 0x00;
+			x25->va        = 0;
+			x25->vr        = 0;
+			x25->vs        = 0;
+			x25->vl        = 0;
+			x25->state     = X25_STATE_3;
+			x25_requeue_frames(sk);
+			break;
+		}
+		case X25_CLEAR_REQUEST:
+			if (!pskb_may_pull(skb, X25_STD_MIN_LEN + 2))
+				goto out_clear;
+
+			x25_write_internal(sk, X25_CLEAR_CONFIRMATION);
+			x25_disconnect(sk, 0, skb->data[3], skb->data[4]);
+			break;
+
+		default:
+			break;
+	}
+
+	return 0;
+
+out_clear:
+	x25_write_internal(sk, X25_CLEAR_REQUEST);
+	x25->state = X25_STATE_2;
+	x25_start_t23timer(sk);
+	return 0;
+}
+
+/* Higher level upcall for a LAPB frame */
+int x25_process_rx_frame(struct sock *sk, struct sk_buff *skb)
+{
+	struct x25_sock *x25 = x25_sk(sk);
+	int queued = 0, frametype, ns, nr, q, d, m;
+
+	if (x25->state == X25_STATE_0)
+		return 0;
+
+	frametype = x25_decode(sk, skb, &ns, &nr, &q, &d, &m);
+
+	switch (x25->state) {
+	case X25_STATE_1:
+		queued = x25_state1_machine(sk, skb, frametype);
+		break;
+	case X25_STATE_2:
+		queued = x25_state2_machine(sk, skb, frametype);
+		break;
+	case X25_STATE_3:
+		queued = x25_state3_machine(sk, skb, frametype, ns, nr, q, d, m);
+		break;
+	case X25_STATE_4:
+		queued = x25_state4_machine(sk, skb, frametype);
+		break;
+	}
+
+	x25_kick(sk);
+
+	return queued;
+}
+
+int x25_backlog_rcv(struct sock *sk, struct sk_buff *skb)
+{
+	int queued = x25_process_rx_frame(sk, skb);
+
+	if (!queued)
+		kfree_skb(skb);
+
+	return 0;
+}