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/*
* 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 (C) 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/module.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/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <linux/uaccess.h>
#include <linux/fcntl.h>
#include <linux/termios.h> /* For TIOCINQ/OUTQ */
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/sysctl.h>
#include <net/ip.h>
#include <net/arp.h>
/*
* IP over AX.25 encapsulation.
*/
/*
* Shove an AX.25 UI header on an IP packet and handle ARP
*/
#ifdef CONFIG_INET
static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type, const void *daddr,
const void *saddr, unsigned int len)
{
unsigned char *buff;
/* they sometimes come back to us... */
if (type == ETH_P_AX25)
return 0;
/* header is an AX.25 UI frame from us to them */
buff = skb_push(skb, AX25_HEADER_LEN);
*buff++ = 0x00; /* KISS DATA */
if (daddr != NULL)
memcpy(buff, daddr, dev->addr_len); /* Address specified */
buff[6] &= ~AX25_CBIT;
buff[6] &= ~AX25_EBIT;
buff[6] |= AX25_SSSID_SPARE;
buff += AX25_ADDR_LEN;
if (saddr != NULL)
memcpy(buff, saddr, dev->addr_len);
else
memcpy(buff, dev->dev_addr, dev->addr_len);
buff[6] &= ~AX25_CBIT;
buff[6] |= AX25_EBIT;
buff[6] |= AX25_SSSID_SPARE;
buff += AX25_ADDR_LEN;
*buff++ = AX25_UI; /* UI */
/* Append a suitable AX.25 PID */
switch (type) {
case ETH_P_IP:
*buff++ = AX25_P_IP;
break;
case ETH_P_ARP:
*buff++ = AX25_P_ARP;
break;
default:
printk(KERN_ERR "AX.25: ax25_hard_header - wrong protocol type 0x%2.2x\n", type);
*buff++ = 0;
break;
}
if (daddr != NULL)
return AX25_HEADER_LEN;
return -AX25_HEADER_LEN; /* Unfinished header */
}
netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
{
struct sk_buff *ourskb;
unsigned char *bp = skb->data;
ax25_route *route;
struct net_device *dev = NULL;
ax25_address *src, *dst;
ax25_digi *digipeat = NULL;
ax25_dev *ax25_dev;
ax25_cb *ax25;
char ip_mode = ' ';
dst = (ax25_address *)(bp + 1);
src = (ax25_address *)(bp + 8);
route = ax25_get_route(dst, NULL);
if (route) {
digipeat = route->digipeat;
dev = route->dev;
ip_mode = route->ip_mode;
}
if (dev == NULL)
dev = skb->dev;
if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
kfree_skb(skb);
goto put;
}
if (bp[16] == AX25_P_IP) {
if (ip_mode == 'V' || (ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) {
/*
* We copy the buffer and release the original thereby
* keeping it straight
*
* Note: we report 1 back so the caller will
* not feed the frame direct to the physical device
* We don't want that to happen. (It won't be upset
* as we have pulled the frame from the queue by
* freeing it).
*
* NB: TCP modifies buffers that are still
* on a device queue, thus we use skb_copy()
* instead of using skb_clone() unless this
* gets fixed.
*/
ax25_address src_c;
ax25_address dst_c;
if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) {
kfree_skb(skb);
goto put;
}
if (skb->sk != NULL)
skb_set_owner_w(ourskb, skb->sk);
kfree_skb(skb);
/* dl9sau: bugfix
* after kfree_skb(), dst and src which were pointer
* to bp which is part of skb->data would not be valid
* anymore hope that after skb_pull(ourskb, ..) our
* dsc_c and src_c will not become invalid
*/
bp = ourskb->data;
dst_c = *(ax25_address *)(bp + 1);
src_c = *(ax25_address *)(bp + 8);
skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */
skb_reset_network_header(ourskb);
ax25=ax25_send_frame(
ourskb,
ax25_dev->values[AX25_VALUES_PACLEN],
&src_c,
&dst_c, digipeat, dev);
if (ax25) {
ax25_cb_put(ax25);
}
goto put;
}
}
bp[7] &= ~AX25_CBIT;
bp[7] &= ~AX25_EBIT;
bp[7] |= AX25_SSSID_SPARE;
bp[14] &= ~AX25_CBIT;
bp[14] |= AX25_EBIT;
bp[14] |= AX25_SSSID_SPARE;
skb_pull(skb, AX25_KISS_HEADER_LEN);
if (digipeat != NULL) {
if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) {
kfree_skb(skb);
goto put;
}
skb = ourskb;
}
ax25_queue_xmit(skb, dev);
put:
if (route)
ax25_put_route(route);
return NETDEV_TX_OK;
}
#else /* INET */
static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type, const void *daddr,
const void *saddr, unsigned int len)
{
return -AX25_HEADER_LEN;
}
netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
{
kfree_skb(skb);
return NETDEV_TX_OK;
}
#endif
static bool ax25_validate_header(const char *header, unsigned int len)
{
ax25_digi digi;
if (!len)
return false;
if (header[0])
return true;
return ax25_addr_parse(header + 1, len - 1, NULL, NULL, &digi, NULL,
NULL);
}
const struct header_ops ax25_header_ops = {
.create = ax25_hard_header,
.validate = ax25_validate_header,
};
EXPORT_SYMBOL(ax25_header_ops);
EXPORT_SYMBOL(ax25_ip_xmit);
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