Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 226 insertions, 0 deletions

diff --git a/net/x25/x25_out.c b/net/x25/x25_out.c
new file mode 100644
index 000000000000..a2e62cea819a
--- /dev/null
+++ b/net/x25/x25_out.c
@@ -0,0 +1,226 @@
+/*
+ *	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	New timer architecture.
+ *	2000-09-04	Henner Eisen	Prevented x25_output() skb leakage.
+ *	2000-10-27	Henner Eisen	MSG_DONTWAIT for fragment allocation.
+ *	2000-11-10	Henner Eisen	x25_send_iframe(): re-queued frames
+ *					needed cleaned seq-number fields.
+ */
+
+#include <linux/socket.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/x25.h>
+
+static int x25_pacsize_to_bytes(unsigned int pacsize)
+{
+	int bytes = 1;
+
+	if (!pacsize)
+		return 128;
+
+	while (pacsize-- > 0)
+		bytes *= 2;
+
+	return bytes;
+}
+
+/*
+ *	This is where all X.25 information frames pass.
+ *
+ *      Returns the amount of user data bytes sent on success
+ *      or a negative error code on failure.
+ */
+int x25_output(struct sock *sk, struct sk_buff *skb)
+{
+	struct sk_buff *skbn;
+	unsigned char header[X25_EXT_MIN_LEN];
+	int err, frontlen, len;
+	int sent=0, noblock = X25_SKB_CB(skb)->flags & MSG_DONTWAIT;
+	struct x25_sock *x25 = x25_sk(sk);
+	int header_len = x25->neighbour->extended ? X25_EXT_MIN_LEN :
+						    X25_STD_MIN_LEN;
+	int max_len = x25_pacsize_to_bytes(x25->facilities.pacsize_out);
+
+	if (skb->len - header_len > max_len) {
+		/* Save a copy of the Header */
+		memcpy(header, skb->data, header_len);
+		skb_pull(skb, header_len);
+
+		frontlen = skb_headroom(skb);
+
+		while (skb->len > 0) {
+			if ((skbn = sock_alloc_send_skb(sk, frontlen + max_len,
+							noblock, &err)) == NULL){
+				if (err == -EWOULDBLOCK && noblock){
+					kfree_skb(skb);
+					return sent;
+				}
+				SOCK_DEBUG(sk, "x25_output: fragment alloc"
+					       " failed, err=%d, %d bytes "
+					       "sent\n", err, sent);
+				return err;
+			}
+				
+			skb_reserve(skbn, frontlen);
+
+			len = max_len > skb->len ? skb->len : max_len;
+
+			/* Copy the user data */
+			memcpy(skb_put(skbn, len), skb->data, len);
+			skb_pull(skb, len);
+
+			/* Duplicate the Header */
+			skb_push(skbn, header_len);
+			memcpy(skbn->data, header, header_len);
+
+			if (skb->len > 0) {
+				if (x25->neighbour->extended)
+					skbn->data[3] |= X25_EXT_M_BIT;
+				else
+					skbn->data[2] |= X25_STD_M_BIT;
+			}
+
+			skb_queue_tail(&sk->sk_write_queue, skbn);
+			sent += len;
+		}
+		
+		kfree_skb(skb);
+	} else {
+		skb_queue_tail(&sk->sk_write_queue, skb);
+		sent = skb->len - header_len;
+	}
+	return sent;
+}
+
+/* 
+ *	This procedure is passed a buffer descriptor for an iframe. It builds
+ *	the rest of the control part of the frame and then writes it out.
+ */
+static void x25_send_iframe(struct sock *sk, struct sk_buff *skb)
+{
+	struct x25_sock *x25 = x25_sk(sk);
+
+	if (!skb)
+		return;
+
+	if (x25->neighbour->extended) {
+		skb->data[2]  = (x25->vs << 1) & 0xFE;
+		skb->data[3] &= X25_EXT_M_BIT;
+		skb->data[3] |= (x25->vr << 1) & 0xFE;
+	} else {
+		skb->data[2] &= X25_STD_M_BIT;
+		skb->data[2] |= (x25->vs << 1) & 0x0E;
+		skb->data[2] |= (x25->vr << 5) & 0xE0;
+	}
+
+	x25_transmit_link(skb, x25->neighbour);	
+}
+
+void x25_kick(struct sock *sk)
+{
+	struct sk_buff *skb, *skbn;
+	unsigned short start, end;
+	int modulus;
+	struct x25_sock *x25 = x25_sk(sk);
+
+	if (x25->state != X25_STATE_3)
+		return;
+
+	/*
+	 *	Transmit interrupt data.
+	 */
+	if (!x25->intflag && skb_peek(&x25->interrupt_out_queue) != NULL) {
+		x25->intflag = 1;
+		skb = skb_dequeue(&x25->interrupt_out_queue);
+		x25_transmit_link(skb, x25->neighbour);
+	}
+
+	if (x25->condition & X25_COND_PEER_RX_BUSY)
+		return;
+
+	if (!skb_peek(&sk->sk_write_queue))
+		return;
+
+	modulus = x25->neighbour->extended ? X25_EMODULUS : X25_SMODULUS;
+
+	start   = skb_peek(&x25->ack_queue) ? x25->vs : x25->va;
+	end     = (x25->va + x25->facilities.winsize_out) % modulus;
+
+	if (start == end)
+		return;
+
+	x25->vs = start;
+
+	/*
+	 * Transmit data until either we're out of data to send or
+	 * the window is full.
+	 */
+
+	skb = skb_dequeue(&sk->sk_write_queue);
+
+	do {
+		if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
+			skb_queue_head(&sk->sk_write_queue, skb);
+			break;
+		}
+
+		skb_set_owner_w(skbn, sk);
+
+		/*
+		 * Transmit the frame copy.
+		 */
+		x25_send_iframe(sk, skbn);
+
+		x25->vs = (x25->vs + 1) % modulus;
+
+		/*
+		 * Requeue the original data frame.
+		 */
+		skb_queue_tail(&x25->ack_queue, skb);
+
+	} while (x25->vs != end &&
+		 (skb = skb_dequeue(&sk->sk_write_queue)) != NULL);
+
+	x25->vl         = x25->vr;
+	x25->condition &= ~X25_COND_ACK_PENDING;
+
+	x25_stop_timer(sk);
+}
+
+/*
+ * The following routines are taken from page 170 of the 7th ARRL Computer
+ * Networking Conference paper, as is the whole state machine.
+ */
+
+void x25_enquiry_response(struct sock *sk)
+{
+	struct x25_sock *x25 = x25_sk(sk);
+
+	if (x25->condition & X25_COND_OWN_RX_BUSY)
+		x25_write_internal(sk, X25_RNR);
+	else
+		x25_write_internal(sk, X25_RR);
+
+	x25->vl         = x25->vr;
+	x25->condition &= ~X25_COND_ACK_PENDING;
+
+	x25_stop_timer(sk);
+}