Initial import

1 files changed, 305 insertions, 0 deletions

diff --git a/net/netrom/nr_in.c b/net/netrom/nr_in.c
new file mode 100644
index 000000000..80dbd0beb
--- /dev/null
+++ b/net/netrom/nr_in.c
@@ -0,0 +1,305 @@
+/*
+ * 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 Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
+ * Copyright Darryl Miles G7LED (dlm@g7led.demon.co.uk)
+ */
+#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 <linux/slab.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/uaccess.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <net/netrom.h>
+
+static int nr_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more)
+{
+	struct sk_buff *skbo, *skbn = skb;
+	struct nr_sock *nr = nr_sk(sk);
+
+	skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
+
+	nr_start_idletimer(sk);
+
+	if (more) {
+		nr->fraglen += skb->len;
+		skb_queue_tail(&nr->frag_queue, skb);
+		return 0;
+	}
+
+	if (!more && nr->fraglen > 0) {	/* End of fragment */
+		nr->fraglen += skb->len;
+		skb_queue_tail(&nr->frag_queue, skb);
+
+		if ((skbn = alloc_skb(nr->fraglen, GFP_ATOMIC)) == NULL)
+			return 1;
+
+		skb_reset_transport_header(skbn);
+
+		while ((skbo = skb_dequeue(&nr->frag_queue)) != NULL) {
+			skb_copy_from_linear_data(skbo,
+						  skb_put(skbn, skbo->len),
+						  skbo->len);
+			kfree_skb(skbo);
+		}
+
+		nr->fraglen = 0;
+	}
+
+	return sock_queue_rcv_skb(sk, skbn);
+}
+
+/*
+ * State machine for state 1, Awaiting Connection State.
+ * The handling of the timer(s) is in file nr_timer.c.
+ * Handling of state 0 and connection release is in netrom.c.
+ */
+static int nr_state1_machine(struct sock *sk, struct sk_buff *skb,
+	int frametype)
+{
+	switch (frametype) {
+	case NR_CONNACK: {
+		struct nr_sock *nr = nr_sk(sk);
+
+		nr_stop_t1timer(sk);
+		nr_start_idletimer(sk);
+		nr->your_index = skb->data[17];
+		nr->your_id    = skb->data[18];
+		nr->vs	       = 0;
+		nr->va	       = 0;
+		nr->vr	       = 0;
+		nr->vl	       = 0;
+		nr->state      = NR_STATE_3;
+		nr->n2count    = 0;
+		nr->window     = skb->data[20];
+		sk->sk_state   = TCP_ESTABLISHED;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk->sk_state_change(sk);
+		break;
+	}
+
+	case NR_CONNACK | NR_CHOKE_FLAG:
+		nr_disconnect(sk, ECONNREFUSED);
+		break;
+
+	case NR_RESET:
+		if (sysctl_netrom_reset_circuit)
+			nr_disconnect(sk, ECONNRESET);
+		break;
+
+	default:
+		break;
+	}
+	return 0;
+}
+
+/*
+ * State machine for state 2, Awaiting Release State.
+ * The handling of the timer(s) is in file nr_timer.c
+ * Handling of state 0 and connection release is in netrom.c.
+ */
+static int nr_state2_machine(struct sock *sk, struct sk_buff *skb,
+	int frametype)
+{
+	switch (frametype) {
+	case NR_CONNACK | NR_CHOKE_FLAG:
+		nr_disconnect(sk, ECONNRESET);
+		break;
+
+	case NR_DISCREQ:
+		nr_write_internal(sk, NR_DISCACK);
+
+	case NR_DISCACK:
+		nr_disconnect(sk, 0);
+		break;
+
+	case NR_RESET:
+		if (sysctl_netrom_reset_circuit)
+			nr_disconnect(sk, ECONNRESET);
+		break;
+
+	default:
+		break;
+	}
+	return 0;
+}
+
+/*
+ * State machine for state 3, Connected State.
+ * The handling of the timer(s) is in file nr_timer.c
+ * Handling of state 0 and connection release is in netrom.c.
+ */
+static int nr_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype)
+{
+	struct nr_sock *nrom = nr_sk(sk);
+	struct sk_buff_head temp_queue;
+	struct sk_buff *skbn;
+	unsigned short save_vr;
+	unsigned short nr, ns;
+	int queued = 0;
+
+	nr = skb->data[18];
+	ns = skb->data[17];
+
+	switch (frametype) {
+	case NR_CONNREQ:
+		nr_write_internal(sk, NR_CONNACK);
+		break;
+
+	case NR_DISCREQ:
+		nr_write_internal(sk, NR_DISCACK);
+		nr_disconnect(sk, 0);
+		break;
+
+	case NR_CONNACK | NR_CHOKE_FLAG:
+	case NR_DISCACK:
+		nr_disconnect(sk, ECONNRESET);
+		break;
+
+	case NR_INFOACK:
+	case NR_INFOACK | NR_CHOKE_FLAG:
+	case NR_INFOACK | NR_NAK_FLAG:
+	case NR_INFOACK | NR_NAK_FLAG | NR_CHOKE_FLAG:
+		if (frametype & NR_CHOKE_FLAG) {
+			nrom->condition |= NR_COND_PEER_RX_BUSY;
+			nr_start_t4timer(sk);
+		} else {
+			nrom->condition &= ~NR_COND_PEER_RX_BUSY;
+			nr_stop_t4timer(sk);
+		}
+		if (!nr_validate_nr(sk, nr)) {
+			break;
+		}
+		if (frametype & NR_NAK_FLAG) {
+			nr_frames_acked(sk, nr);
+			nr_send_nak_frame(sk);
+		} else {
+			if (nrom->condition & NR_COND_PEER_RX_BUSY) {
+				nr_frames_acked(sk, nr);
+			} else {
+				nr_check_iframes_acked(sk, nr);
+			}
+		}
+		break;
+
+	case NR_INFO:
+	case NR_INFO | NR_NAK_FLAG:
+	case NR_INFO | NR_CHOKE_FLAG:
+	case NR_INFO | NR_MORE_FLAG:
+	case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG:
+	case NR_INFO | NR_CHOKE_FLAG | NR_MORE_FLAG:
+	case NR_INFO | NR_NAK_FLAG | NR_MORE_FLAG:
+	case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG | NR_MORE_FLAG:
+		if (frametype & NR_CHOKE_FLAG) {
+			nrom->condition |= NR_COND_PEER_RX_BUSY;
+			nr_start_t4timer(sk);
+		} else {
+			nrom->condition &= ~NR_COND_PEER_RX_BUSY;
+			nr_stop_t4timer(sk);
+		}
+		if (nr_validate_nr(sk, nr)) {
+			if (frametype & NR_NAK_FLAG) {
+				nr_frames_acked(sk, nr);
+				nr_send_nak_frame(sk);
+			} else {
+				if (nrom->condition & NR_COND_PEER_RX_BUSY) {
+					nr_frames_acked(sk, nr);
+				} else {
+					nr_check_iframes_acked(sk, nr);
+				}
+			}
+		}
+		queued = 1;
+		skb_queue_head(&nrom->reseq_queue, skb);
+		if (nrom->condition & NR_COND_OWN_RX_BUSY)
+			break;
+		skb_queue_head_init(&temp_queue);
+		do {
+			save_vr = nrom->vr;
+			while ((skbn = skb_dequeue(&nrom->reseq_queue)) != NULL) {
+				ns = skbn->data[17];
+				if (ns == nrom->vr) {
+					if (nr_queue_rx_frame(sk, skbn, frametype & NR_MORE_FLAG) == 0) {
+						nrom->vr = (nrom->vr + 1) % NR_MODULUS;
+					} else {
+						nrom->condition |= NR_COND_OWN_RX_BUSY;
+						skb_queue_tail(&temp_queue, skbn);
+					}
+				} else if (nr_in_rx_window(sk, ns)) {
+					skb_queue_tail(&temp_queue, skbn);
+				} else {
+					kfree_skb(skbn);
+				}
+			}
+			while ((skbn = skb_dequeue(&temp_queue)) != NULL) {
+				skb_queue_tail(&nrom->reseq_queue, skbn);
+			}
+		} while (save_vr != nrom->vr);
+		/*
+		 * Window is full, ack it immediately.
+		 */
+		if (((nrom->vl + nrom->window) % NR_MODULUS) == nrom->vr) {
+			nr_enquiry_response(sk);
+		} else {
+			if (!(nrom->condition & NR_COND_ACK_PENDING)) {
+				nrom->condition |= NR_COND_ACK_PENDING;
+				nr_start_t2timer(sk);
+			}
+		}
+		break;
+
+	case NR_RESET:
+		if (sysctl_netrom_reset_circuit)
+			nr_disconnect(sk, ECONNRESET);
+		break;
+
+	default:
+		break;
+	}
+	return queued;
+}
+
+/* Higher level upcall for a LAPB frame - called with sk locked */
+int nr_process_rx_frame(struct sock *sk, struct sk_buff *skb)
+{
+	struct nr_sock *nr = nr_sk(sk);
+	int queued = 0, frametype;
+
+	if (nr->state == NR_STATE_0)
+		return 0;
+
+	frametype = skb->data[19];
+
+	switch (nr->state) {
+	case NR_STATE_1:
+		queued = nr_state1_machine(sk, skb, frametype);
+		break;
+	case NR_STATE_2:
+		queued = nr_state2_machine(sk, skb, frametype);
+		break;
+	case NR_STATE_3:
+		queued = nr_state3_machine(sk, skb, frametype);
+		break;
+	}
+
+	nr_kick(sk);
+
+	return queued;
+}