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-rw-r--r--net/netrom/nr_in.c305
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..fbfdae452
--- /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);
+ /* fall through */
+ 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;
+}
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