Initial import

1 files changed, 294 insertions, 0 deletions

diff --git a/net/rose/rose_in.c b/net/rose/rose_in.c
new file mode 100644
index 000000000..79c4abcfa
--- /dev/null
+++ b/net/rose/rose_in.c
@@ -0,0 +1,294 @@
+/*
+ * 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.
+ *
+ * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
+ *
+ * Most of this code is based on the SDL diagrams published in the 7th ARRL
+ * Computer Networking Conference papers. The diagrams have mistakes in them,
+ * but are mostly correct. Before you modify the code could you read the SDL
+ * diagrams as the code is not obvious and probably very easy to break.
+ */
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <net/ax25.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/tcp_states.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <net/rose.h>
+
+/*
+ * State machine for state 1, Awaiting Call Accepted State.
+ * The handling of the timer(s) is in file rose_timer.c.
+ * Handling of state 0 and connection release is in af_rose.c.
+ */
+static int rose_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype)
+{
+	struct rose_sock *rose = rose_sk(sk);
+
+	switch (frametype) {
+	case ROSE_CALL_ACCEPTED:
+		rose_stop_timer(sk);
+		rose_start_idletimer(sk);
+		rose->condition = 0x00;
+		rose->vs        = 0;
+		rose->va        = 0;
+		rose->vr        = 0;
+		rose->vl        = 0;
+		rose->state     = ROSE_STATE_3;
+		sk->sk_state	= TCP_ESTABLISHED;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk->sk_state_change(sk);
+		break;
+
+	case ROSE_CLEAR_REQUEST:
+		rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
+		rose_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]);
+		rose->neighbour->use--;
+		break;
+
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+/*
+ * State machine for state 2, Awaiting Clear Confirmation State.
+ * The handling of the timer(s) is in file rose_timer.c
+ * Handling of state 0 and connection release is in af_rose.c.
+ */
+static int rose_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype)
+{
+	struct rose_sock *rose = rose_sk(sk);
+
+	switch (frametype) {
+	case ROSE_CLEAR_REQUEST:
+		rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
+		rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
+		rose->neighbour->use--;
+		break;
+
+	case ROSE_CLEAR_CONFIRMATION:
+		rose_disconnect(sk, 0, -1, -1);
+		rose->neighbour->use--;
+		break;
+
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+/*
+ * State machine for state 3, Connected State.
+ * The handling of the timer(s) is in file rose_timer.c
+ * Handling of state 0 and connection release is in af_rose.c.
+ */
+static int rose_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m)
+{
+	struct rose_sock *rose = rose_sk(sk);
+	int queued = 0;
+
+	switch (frametype) {
+	case ROSE_RESET_REQUEST:
+		rose_stop_timer(sk);
+		rose_start_idletimer(sk);
+		rose_write_internal(sk, ROSE_RESET_CONFIRMATION);
+		rose->condition = 0x00;
+		rose->vs        = 0;
+		rose->vr        = 0;
+		rose->va        = 0;
+		rose->vl        = 0;
+		rose_requeue_frames(sk);
+		break;
+
+	case ROSE_CLEAR_REQUEST:
+		rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
+		rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
+		rose->neighbour->use--;
+		break;
+
+	case ROSE_RR:
+	case ROSE_RNR:
+		if (!rose_validate_nr(sk, nr)) {
+			rose_write_internal(sk, ROSE_RESET_REQUEST);
+			rose->condition = 0x00;
+			rose->vs        = 0;
+			rose->vr        = 0;
+			rose->va        = 0;
+			rose->vl        = 0;
+			rose->state     = ROSE_STATE_4;
+			rose_start_t2timer(sk);
+			rose_stop_idletimer(sk);
+		} else {
+			rose_frames_acked(sk, nr);
+			if (frametype == ROSE_RNR) {
+				rose->condition |= ROSE_COND_PEER_RX_BUSY;
+			} else {
+				rose->condition &= ~ROSE_COND_PEER_RX_BUSY;
+			}
+		}
+		break;
+
+	case ROSE_DATA:	/* XXX */
+		rose->condition &= ~ROSE_COND_PEER_RX_BUSY;
+		if (!rose_validate_nr(sk, nr)) {
+			rose_write_internal(sk, ROSE_RESET_REQUEST);
+			rose->condition = 0x00;
+			rose->vs        = 0;
+			rose->vr        = 0;
+			rose->va        = 0;
+			rose->vl        = 0;
+			rose->state     = ROSE_STATE_4;
+			rose_start_t2timer(sk);
+			rose_stop_idletimer(sk);
+			break;
+		}
+		rose_frames_acked(sk, nr);
+		if (ns == rose->vr) {
+			rose_start_idletimer(sk);
+			if (sock_queue_rcv_skb(sk, skb) == 0) {
+				rose->vr = (rose->vr + 1) % ROSE_MODULUS;
+				queued = 1;
+			} else {
+				/* Should never happen ! */
+				rose_write_internal(sk, ROSE_RESET_REQUEST);
+				rose->condition = 0x00;
+				rose->vs        = 0;
+				rose->vr        = 0;
+				rose->va        = 0;
+				rose->vl        = 0;
+				rose->state     = ROSE_STATE_4;
+				rose_start_t2timer(sk);
+				rose_stop_idletimer(sk);
+				break;
+			}
+			if (atomic_read(&sk->sk_rmem_alloc) >
+			    (sk->sk_rcvbuf >> 1))
+				rose->condition |= ROSE_COND_OWN_RX_BUSY;
+		}
+		/*
+		 * If the window is full, ack the frame, else start the
+		 * acknowledge hold back timer.
+		 */
+		if (((rose->vl + sysctl_rose_window_size) % ROSE_MODULUS) == rose->vr) {
+			rose->condition &= ~ROSE_COND_ACK_PENDING;
+			rose_stop_timer(sk);
+			rose_enquiry_response(sk);
+		} else {
+			rose->condition |= ROSE_COND_ACK_PENDING;
+			rose_start_hbtimer(sk);
+		}
+		break;
+
+	default:
+		printk(KERN_WARNING "ROSE: unknown %02X in state 3\n", frametype);
+		break;
+	}
+
+	return queued;
+}
+
+/*
+ * State machine for state 4, Awaiting Reset Confirmation State.
+ * The handling of the timer(s) is in file rose_timer.c
+ * Handling of state 0 and connection release is in af_rose.c.
+ */
+static int rose_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype)
+{
+	struct rose_sock *rose = rose_sk(sk);
+
+	switch (frametype) {
+	case ROSE_RESET_REQUEST:
+		rose_write_internal(sk, ROSE_RESET_CONFIRMATION);
+	case ROSE_RESET_CONFIRMATION:
+		rose_stop_timer(sk);
+		rose_start_idletimer(sk);
+		rose->condition = 0x00;
+		rose->va        = 0;
+		rose->vr        = 0;
+		rose->vs        = 0;
+		rose->vl        = 0;
+		rose->state     = ROSE_STATE_3;
+		rose_requeue_frames(sk);
+		break;
+
+	case ROSE_CLEAR_REQUEST:
+		rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
+		rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
+		rose->neighbour->use--;
+		break;
+
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+/*
+ * State machine for state 5, Awaiting Call Acceptance State.
+ * The handling of the timer(s) is in file rose_timer.c
+ * Handling of state 0 and connection release is in af_rose.c.
+ */
+static int rose_state5_machine(struct sock *sk, struct sk_buff *skb, int frametype)
+{
+	if (frametype == ROSE_CLEAR_REQUEST) {
+		rose_write_internal(sk, ROSE_CLEAR_CONFIRMATION);
+		rose_disconnect(sk, 0, skb->data[3], skb->data[4]);
+		rose_sk(sk)->neighbour->use--;
+	}
+
+	return 0;
+}
+
+/* Higher level upcall for a LAPB frame */
+int rose_process_rx_frame(struct sock *sk, struct sk_buff *skb)
+{
+	struct rose_sock *rose = rose_sk(sk);
+	int queued = 0, frametype, ns, nr, q, d, m;
+
+	if (rose->state == ROSE_STATE_0)
+		return 0;
+
+	frametype = rose_decode(skb, &ns, &nr, &q, &d, &m);
+
+	switch (rose->state) {
+	case ROSE_STATE_1:
+		queued = rose_state1_machine(sk, skb, frametype);
+		break;
+	case ROSE_STATE_2:
+		queued = rose_state2_machine(sk, skb, frametype);
+		break;
+	case ROSE_STATE_3:
+		queued = rose_state3_machine(sk, skb, frametype, ns, nr, q, d, m);
+		break;
+	case ROSE_STATE_4:
+		queued = rose_state4_machine(sk, skb, frametype);
+		break;
+	case ROSE_STATE_5:
+		queued = rose_state5_machine(sk, skb, frametype);
+		break;
+	}
+
+	rose_kick(sk);
+
+	return queued;
+}