linux/net/ax25/ax25_ip.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

249 lines
5.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* 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);
ax25_route_lock_use();
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:
ax25_route_lock_unuse();
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);