1 files changed, 283 insertions, 0 deletions

diff --git a/net/netrom/nr_subr.c b/net/netrom/nr_subr.c
new file mode 100644
index 000000000000..0627347b14b8
--- /dev/null
+++ b/net/netrom/nr_subr.c
@@ -0,0 +1,283 @@
+/*
+ * 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)
+ */
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/kernel.h>
+#include <linux/sched.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.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <net/netrom.h>
+
+/*
+ *      This routine purges all of the queues of frames.
+ */
+void nr_clear_queues(struct sock *sk)
+{
+        struct nr_sock *nr = nr_sk(sk);
+
+        skb_queue_purge(&sk->sk_write_queue);
+        skb_queue_purge(&nr->ack_queue);
+        skb_queue_purge(&nr->reseq_queue);
+        skb_queue_purge(&nr->frag_queue);
+}
+
+/*
+ * This routine purges the input queue of those frames that have been
+ * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the
+ * SDL diagram.
+ */
+void nr_frames_acked(struct sock *sk, unsigned short nr)
+{
+        struct nr_sock *nrom = nr_sk(sk);
+        struct sk_buff *skb;
+
+        /*
+         * Remove all the ack-ed frames from the ack queue.
+         */
+        if (nrom->va != nr) {
+                while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) {
+                        skb = skb_dequeue(&nrom->ack_queue);
+                        kfree_skb(skb);
+                        nrom->va = (nrom->va + 1) % NR_MODULUS;
+                }
+        }
+}
+
+/*
+ * Requeue all the un-ack-ed frames on the output queue to be picked
+ * up by nr_kick called from the timer. This arrangement handles the
+ * possibility of an empty output queue.
+ */
+void nr_requeue_frames(struct sock *sk)
+{
+        struct sk_buff *skb, *skb_prev = NULL;
+
+        while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) {
+                if (skb_prev == NULL)
+                        skb_queue_head(&sk->sk_write_queue, skb);
+                else
+                        skb_append(skb_prev, skb);
+                skb_prev = skb;
+        }
+}
+
+/*
+ *      Validate that the value of nr is between va and vs. Return true or
+ *      false for testing.
+ */
+int nr_validate_nr(struct sock *sk, unsigned short nr)
+{
+        struct nr_sock *nrom = nr_sk(sk);
+        unsigned short vc = nrom->va;
+
+        while (vc != nrom->vs) {
+                if (nr == vc) return 1;
+                vc = (vc + 1) % NR_MODULUS;
+        }
+
+        return nr == nrom->vs;
+}
+
+/*
+ *      Check that ns is within the receive window.
+ */
+int nr_in_rx_window(struct sock *sk, unsigned short ns)
+{
+        struct nr_sock *nr = nr_sk(sk);
+        unsigned short vc = nr->vr;
+        unsigned short vt = (nr->vl + nr->window) % NR_MODULUS;
+
+        while (vc != vt) {
+                if (ns == vc) return 1;
+                vc = (vc + 1) % NR_MODULUS;
+        }
+
+        return 0;
+}
+
+/*
+ *  This routine is called when the HDLC layer internally generates a
+ *  control frame.
+ */
+void nr_write_internal(struct sock *sk, int frametype)
+{
+        struct nr_sock *nr = nr_sk(sk);
+        struct sk_buff *skb;
+        unsigned char  *dptr;
+        int len, timeout;
+
+        len = NR_NETWORK_LEN + NR_TRANSPORT_LEN;
+
+        switch (frametype & 0x0F) {
+        case NR_CONNREQ:
+                len += 17;
+                break;
+        case NR_CONNACK:
+                len += (nr->bpqext) ? 2 : 1;
+                break;
+        case NR_DISCREQ:
+        case NR_DISCACK:
+        case NR_INFOACK:
+                break;
+        default:
+                printk(KERN_ERR "NET/ROM: nr_write_internal - invalid frame type %d\n", frametype);
+                return;
+        }
+
+        if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL)
+                return;
+
+        /*
+         *      Space for AX.25 and NET/ROM network header
+         */
+        skb_reserve(skb, NR_NETWORK_LEN);
+
+        dptr = skb_put(skb, skb_tailroom(skb));
+
+        switch (frametype & 0x0F) {
+        case NR_CONNREQ:
+                timeout  = nr->t1 / HZ;
+                *dptr++  = nr->my_index;
+                *dptr++  = nr->my_id;
+                *dptr++  = 0;
+                *dptr++  = 0;
+                *dptr++  = frametype;
+                *dptr++  = nr->window;
+                memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN);
+                dptr[6] &= ~AX25_CBIT;
+                dptr[6] &= ~AX25_EBIT;
+                dptr[6] |= AX25_SSSID_SPARE;
+                dptr    += AX25_ADDR_LEN;
+                memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN);
+                dptr[6] &= ~AX25_CBIT;
+                dptr[6] &= ~AX25_EBIT;
+                dptr[6] |= AX25_SSSID_SPARE;
+                dptr    += AX25_ADDR_LEN;
+                *dptr++  = timeout % 256;
+                *dptr++  = timeout / 256;
+                break;
+
+        case NR_CONNACK:
+                *dptr++ = nr->your_index;
+                *dptr++ = nr->your_id;
+                *dptr++ = nr->my_index;
+                *dptr++ = nr->my_id;
+                *dptr++ = frametype;
+                *dptr++ = nr->window;
+                if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser;
+                break;
+
+        case NR_DISCREQ:
+        case NR_DISCACK:
+                *dptr++ = nr->your_index;
+                *dptr++ = nr->your_id;
+                *dptr++ = 0;
+                *dptr++ = 0;
+                *dptr++ = frametype;
+                break;
+
+        case NR_INFOACK:
+                *dptr++ = nr->your_index;
+                *dptr++ = nr->your_id;
+                *dptr++ = 0;
+                *dptr++ = nr->vr;
+                *dptr++ = frametype;
+                break;
+        }
+
+        nr_transmit_buffer(sk, skb);
+}
+
+/*
+ * This routine is called when a Connect Acknowledge with the Choke Flag
+ * set is needed to refuse a connection.
+ */
+void nr_transmit_refusal(struct sk_buff *skb, int mine)
+{
+        struct sk_buff *skbn;
+        unsigned char *dptr;
+        int len;
+
+        len = NR_NETWORK_LEN + NR_TRANSPORT_LEN + 1;
+
+        if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL)
+                return;
+
+        skb_reserve(skbn, 0);
+
+        dptr = skb_put(skbn, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
+
+        memcpy(dptr, skb->data + 7, AX25_ADDR_LEN);
+        dptr[6] &= ~AX25_CBIT;
+        dptr[6] &= ~AX25_EBIT;
+        dptr[6] |= AX25_SSSID_SPARE;
+        dptr += AX25_ADDR_LEN;
+
+        memcpy(dptr, skb->data + 0, AX25_ADDR_LEN);
+        dptr[6] &= ~AX25_CBIT;
+        dptr[6] |= AX25_EBIT;
+        dptr[6] |= AX25_SSSID_SPARE;
+        dptr += AX25_ADDR_LEN;
+
+        *dptr++ = sysctl_netrom_network_ttl_initialiser;
+
+        if (mine) {
+                *dptr++ = 0;
+                *dptr++ = 0;
+                *dptr++ = skb->data[15];
+                *dptr++ = skb->data[16];
+        } else {
+                *dptr++ = skb->data[15];
+                *dptr++ = skb->data[16];
+                *dptr++ = 0;
+                *dptr++ = 0;
+        }
+
+        *dptr++ = NR_CONNACK | NR_CHOKE_FLAG;
+        *dptr++ = 0;
+
+        if (!nr_route_frame(skbn, NULL))
+                kfree_skb(skbn);
+}
+
+void nr_disconnect(struct sock *sk, int reason)
+{
+        nr_stop_t1timer(sk);
+        nr_stop_t2timer(sk);
+        nr_stop_t4timer(sk);
+        nr_stop_idletimer(sk);
+
+        nr_clear_queues(sk);
+
+        nr_sk(sk)->state = NR_STATE_0;
+
+        sk->sk_state     = TCP_CLOSE;
+        sk->sk_err       = reason;
+        sk->sk_shutdown |= SEND_SHUTDOWN;
+
+        if (!sock_flag(sk, SOCK_DEAD)) {
+                sk->sk_state_change(sk);
+                sock_set_flag(sk, SOCK_DEAD);
+        }
+}