/*
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/*
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* X.25 Packet Layer release 002
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* X.25 Packet Layer release 002
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*
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*
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* This is ALPHA test software. This code may break your machine, randomly fail to work with new
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* This is ALPHA test software. This code may break your machine, randomly fail to work with new
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* releases, misbehave and/or generally screw up. It might even work.
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* releases, misbehave and/or generally screw up. It might even work.
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*
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*
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* This code REQUIRES 2.1.15 or higher
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* This code REQUIRES 2.1.15 or higher
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*
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*
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* This module:
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* This module:
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* This module is free software; you can redistribute it and/or
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* This module is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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* 2 of the License, or (at your option) any later version.
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*
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*
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* History
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* History
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* X.25 001 Jonathan Naylor Started coding.
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* X.25 001 Jonathan Naylor Started coding.
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* X.25 002 Jonathan Naylor New timer architecture.
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* X.25 002 Jonathan Naylor New timer architecture.
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* 2000-09-04 Henner Eisen Prevented x25_output() skb leakage.
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* 2000-09-04 Henner Eisen Prevented x25_output() skb leakage.
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* 2000-10-27 Henner Eisen MSG_DONTWAIT for fragment allocation.
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* 2000-10-27 Henner Eisen MSG_DONTWAIT for fragment allocation.
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* 2000-11-10 Henner Eisen x25_send_iframe(): re-queued frames
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* 2000-11-10 Henner Eisen x25_send_iframe(): re-queued frames
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* needed cleaned seq-number fields.
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* needed cleaned seq-number fields.
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*/
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*/
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#include <linux/errno.h>
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/types.h>
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#include <linux/socket.h>
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#include <linux/socket.h>
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#include <linux/in.h>
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#include <linux/in.h>
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#include <linux/kernel.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/sched.h>
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#include <linux/timer.h>
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#include <linux/timer.h>
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#include <linux/string.h>
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#include <linux/string.h>
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#include <linux/sockios.h>
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#include <linux/sockios.h>
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#include <linux/net.h>
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#include <linux/net.h>
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#include <linux/inet.h>
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#include <linux/inet.h>
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#include <linux/netdevice.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include <linux/skbuff.h>
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#include <net/sock.h>
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#include <net/sock.h>
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#include <asm/segment.h>
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#include <asm/segment.h>
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#include <asm/system.h>
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#include <asm/system.h>
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#include <linux/fcntl.h>
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#include <linux/fcntl.h>
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#include <linux/mm.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/interrupt.h>
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#include <net/x25.h>
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#include <net/x25.h>
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static int x25_pacsize_to_bytes(unsigned int pacsize)
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static int x25_pacsize_to_bytes(unsigned int pacsize)
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{
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{
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int bytes = 1;
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int bytes = 1;
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if (pacsize == 0)
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if (pacsize == 0)
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return 128;
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return 128;
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while (pacsize-- > 0)
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while (pacsize-- > 0)
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bytes *= 2;
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bytes *= 2;
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return bytes;
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return bytes;
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}
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}
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/*
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/*
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* This is where all X.25 information frames pass.
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* This is where all X.25 information frames pass.
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*
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*
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* Returns the amount of user data bytes sent on success
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* Returns the amount of user data bytes sent on success
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* or a negative error code on failure.
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* or a negative error code on failure.
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*/
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*/
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int x25_output(struct sock *sk, struct sk_buff *skb)
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int x25_output(struct sock *sk, struct sk_buff *skb)
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{
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{
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struct sk_buff *skbn;
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struct sk_buff *skbn;
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unsigned char header[X25_EXT_MIN_LEN];
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unsigned char header[X25_EXT_MIN_LEN];
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int err, frontlen, len, header_len, max_len;
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int err, frontlen, len, header_len, max_len;
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int sent=0, noblock = X25_SKB_CB(skb)->flags & MSG_DONTWAIT;
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int sent=0, noblock = X25_SKB_CB(skb)->flags & MSG_DONTWAIT;
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header_len = (sk->protinfo.x25->neighbour->extended) ? X25_EXT_MIN_LEN : X25_STD_MIN_LEN;
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header_len = (sk->protinfo.x25->neighbour->extended) ? X25_EXT_MIN_LEN : X25_STD_MIN_LEN;
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max_len = x25_pacsize_to_bytes(sk->protinfo.x25->facilities.pacsize_out);
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max_len = x25_pacsize_to_bytes(sk->protinfo.x25->facilities.pacsize_out);
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if (skb->len - header_len > max_len) {
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if (skb->len - header_len > max_len) {
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/* Save a copy of the Header */
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/* Save a copy of the Header */
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memcpy(header, skb->data, header_len);
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memcpy(header, skb->data, header_len);
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skb_pull(skb, header_len);
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skb_pull(skb, header_len);
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frontlen = skb_headroom(skb);
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frontlen = skb_headroom(skb);
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while (skb->len > 0) {
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while (skb->len > 0) {
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if ((skbn = sock_alloc_send_skb(sk, frontlen + max_len, noblock, &err)) == NULL){
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if ((skbn = sock_alloc_send_skb(sk, frontlen + max_len, noblock, &err)) == NULL){
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if(err == -EWOULDBLOCK && noblock){
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if(err == -EWOULDBLOCK && noblock){
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kfree_skb(skb);
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kfree_skb(skb);
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return sent;
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return sent;
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}
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}
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SOCK_DEBUG(sk, "x25_output: fragment allocation failed, err=%d, %d bytes sent\n", err, sent);
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SOCK_DEBUG(sk, "x25_output: fragment allocation failed, err=%d, %d bytes sent\n", err, sent);
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return err;
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return err;
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}
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}
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skb_reserve(skbn, frontlen);
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skb_reserve(skbn, frontlen);
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len = (max_len > skb->len) ? skb->len : max_len;
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len = (max_len > skb->len) ? skb->len : max_len;
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/* Copy the user data */
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/* Copy the user data */
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memcpy(skb_put(skbn, len), skb->data, len);
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memcpy(skb_put(skbn, len), skb->data, len);
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skb_pull(skb, len);
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skb_pull(skb, len);
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/* Duplicate the Header */
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/* Duplicate the Header */
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skb_push(skbn, header_len);
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skb_push(skbn, header_len);
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memcpy(skbn->data, header, header_len);
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memcpy(skbn->data, header, header_len);
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if (skb->len > 0) {
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if (skb->len > 0) {
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if (sk->protinfo.x25->neighbour->extended)
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if (sk->protinfo.x25->neighbour->extended)
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skbn->data[3] |= X25_EXT_M_BIT;
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skbn->data[3] |= X25_EXT_M_BIT;
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else
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else
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skbn->data[2] |= X25_STD_M_BIT;
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skbn->data[2] |= X25_STD_M_BIT;
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}
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}
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skb_queue_tail(&sk->write_queue, skbn);
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skb_queue_tail(&sk->write_queue, skbn);
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sent += len;
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sent += len;
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}
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}
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kfree_skb(skb);
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kfree_skb(skb);
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} else {
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} else {
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skb_queue_tail(&sk->write_queue, skb);
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skb_queue_tail(&sk->write_queue, skb);
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sent = skb->len - header_len;
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sent = skb->len - header_len;
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}
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}
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return sent;
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return sent;
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}
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}
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/*
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/*
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* This procedure is passed a buffer descriptor for an iframe. It builds
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* This procedure is passed a buffer descriptor for an iframe. It builds
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* the rest of the control part of the frame and then writes it out.
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* the rest of the control part of the frame and then writes it out.
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*/
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*/
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static void x25_send_iframe(struct sock *sk, struct sk_buff *skb)
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static void x25_send_iframe(struct sock *sk, struct sk_buff *skb)
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{
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{
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if (skb == NULL)
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if (skb == NULL)
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return;
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return;
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if (sk->protinfo.x25->neighbour->extended) {
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if (sk->protinfo.x25->neighbour->extended) {
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skb->data[2] = (sk->protinfo.x25->vs << 1) & 0xFE;
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skb->data[2] = (sk->protinfo.x25->vs << 1) & 0xFE;
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skb->data[3] &= X25_EXT_M_BIT;
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skb->data[3] &= X25_EXT_M_BIT;
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skb->data[3] |= (sk->protinfo.x25->vr << 1) & 0xFE;
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skb->data[3] |= (sk->protinfo.x25->vr << 1) & 0xFE;
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} else {
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} else {
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skb->data[2] &= X25_STD_M_BIT;
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skb->data[2] &= X25_STD_M_BIT;
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skb->data[2] |= (sk->protinfo.x25->vs << 1) & 0x0E;
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skb->data[2] |= (sk->protinfo.x25->vs << 1) & 0x0E;
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skb->data[2] |= (sk->protinfo.x25->vr << 5) & 0xE0;
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skb->data[2] |= (sk->protinfo.x25->vr << 5) & 0xE0;
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}
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}
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x25_transmit_link(skb, sk->protinfo.x25->neighbour);
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x25_transmit_link(skb, sk->protinfo.x25->neighbour);
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}
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}
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void x25_kick(struct sock *sk)
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void x25_kick(struct sock *sk)
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{
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{
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struct sk_buff *skb, *skbn;
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struct sk_buff *skb, *skbn;
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unsigned short start, end;
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unsigned short start, end;
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int modulus;
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int modulus;
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if (sk->protinfo.x25->state != X25_STATE_3)
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if (sk->protinfo.x25->state != X25_STATE_3)
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return;
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return;
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/*
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/*
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* Transmit interrupt data.
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* Transmit interrupt data.
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*/
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*/
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if (!sk->protinfo.x25->intflag && skb_peek(&sk->protinfo.x25->interrupt_out_queue) != NULL) {
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if (!sk->protinfo.x25->intflag && skb_peek(&sk->protinfo.x25->interrupt_out_queue) != NULL) {
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sk->protinfo.x25->intflag = 1;
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sk->protinfo.x25->intflag = 1;
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skb = skb_dequeue(&sk->protinfo.x25->interrupt_out_queue);
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skb = skb_dequeue(&sk->protinfo.x25->interrupt_out_queue);
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x25_transmit_link(skb, sk->protinfo.x25->neighbour);
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x25_transmit_link(skb, sk->protinfo.x25->neighbour);
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}
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}
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if (sk->protinfo.x25->condition & X25_COND_PEER_RX_BUSY)
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if (sk->protinfo.x25->condition & X25_COND_PEER_RX_BUSY)
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return;
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return;
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if (skb_peek(&sk->write_queue) == NULL)
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if (skb_peek(&sk->write_queue) == NULL)
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return;
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return;
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modulus = (sk->protinfo.x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS;
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modulus = (sk->protinfo.x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS;
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start = (skb_peek(&sk->protinfo.x25->ack_queue) == NULL) ? sk->protinfo.x25->va : sk->protinfo.x25->vs;
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start = (skb_peek(&sk->protinfo.x25->ack_queue) == NULL) ? sk->protinfo.x25->va : sk->protinfo.x25->vs;
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end = (sk->protinfo.x25->va + sk->protinfo.x25->facilities.winsize_out) % modulus;
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end = (sk->protinfo.x25->va + sk->protinfo.x25->facilities.winsize_out) % modulus;
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if (start == end)
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if (start == end)
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return;
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return;
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sk->protinfo.x25->vs = start;
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sk->protinfo.x25->vs = start;
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/*
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/*
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* Transmit data until either we're out of data to send or
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* Transmit data until either we're out of data to send or
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* the window is full.
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* the window is full.
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*/
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*/
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skb = skb_dequeue(&sk->write_queue);
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skb = skb_dequeue(&sk->write_queue);
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do {
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do {
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if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
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if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
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skb_queue_head(&sk->write_queue, skb);
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skb_queue_head(&sk->write_queue, skb);
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break;
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break;
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}
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}
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skb_set_owner_w(skbn, sk);
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skb_set_owner_w(skbn, sk);
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/*
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/*
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* Transmit the frame copy.
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* Transmit the frame copy.
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*/
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*/
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x25_send_iframe(sk, skbn);
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x25_send_iframe(sk, skbn);
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sk->protinfo.x25->vs = (sk->protinfo.x25->vs + 1) % modulus;
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sk->protinfo.x25->vs = (sk->protinfo.x25->vs + 1) % modulus;
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/*
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/*
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* Requeue the original data frame.
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* Requeue the original data frame.
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*/
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*/
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skb_queue_tail(&sk->protinfo.x25->ack_queue, skb);
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skb_queue_tail(&sk->protinfo.x25->ack_queue, skb);
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} while (sk->protinfo.x25->vs != end && (skb = skb_dequeue(&sk->write_queue)) != NULL);
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} while (sk->protinfo.x25->vs != end && (skb = skb_dequeue(&sk->write_queue)) != NULL);
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sk->protinfo.x25->vl = sk->protinfo.x25->vr;
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sk->protinfo.x25->vl = sk->protinfo.x25->vr;
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sk->protinfo.x25->condition &= ~X25_COND_ACK_PENDING;
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sk->protinfo.x25->condition &= ~X25_COND_ACK_PENDING;
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x25_stop_timer(sk);
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x25_stop_timer(sk);
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}
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}
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/*
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/*
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* The following routines are taken from page 170 of the 7th ARRL Computer
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* The following routines are taken from page 170 of the 7th ARRL Computer
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* Networking Conference paper, as is the whole state machine.
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* Networking Conference paper, as is the whole state machine.
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*/
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*/
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void x25_enquiry_response(struct sock *sk)
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void x25_enquiry_response(struct sock *sk)
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{
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{
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if (sk->protinfo.x25->condition & X25_COND_OWN_RX_BUSY)
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if (sk->protinfo.x25->condition & X25_COND_OWN_RX_BUSY)
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x25_write_internal(sk, X25_RNR);
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x25_write_internal(sk, X25_RNR);
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else
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else
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x25_write_internal(sk, X25_RR);
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x25_write_internal(sk, X25_RR);
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sk->protinfo.x25->vl = sk->protinfo.x25->vr;
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sk->protinfo.x25->vl = sk->protinfo.x25->vr;
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sk->protinfo.x25->condition &= ~X25_COND_ACK_PENDING;
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sk->protinfo.x25->condition &= ~X25_COND_ACK_PENDING;
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x25_stop_timer(sk);
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x25_stop_timer(sk);
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}
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}
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