[mirror_ubuntu-artful-kernel.git] / net / ax25 / ax25_ip.c

/*
 * 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/config.h>
#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/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/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <asm/system.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/netfilter.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

int ax25_hard_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, void *daddr, void *saddr, unsigned 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 */
}

int ax25_rebuild_header(struct sk_buff *skb)
{
	struct sk_buff *ourskb;
	unsigned char *bp  = skb->data;
	struct net_device *dev;
	ax25_address *src, *dst;
	ax25_dev *ax25_dev;
	ax25_route _route, *route = &_route;
	ax25_cb *ax25;

	dst = (ax25_address *)(bp + 1);
	src = (ax25_address *)(bp + 8);

  	if (arp_find(bp + 1, skb))
  		return 1;

	route = ax25_rt_find_route(route, dst, NULL);
	dev      = route->dev;

	if (dev == NULL)
		dev = skb->dev;

        if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
                goto put;
	}

	if (bp[16] == AX25_P_IP) {
		if (route->ip_mode == 'V' || (route->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 */
			ourskb->nh.raw = ourskb->data;

			ax25=ax25_send_frame(
			    ourskb, 
			    ax25_dev->values[AX25_VALUES_PACLEN], 
			    &src_c,
			    &dst_c, route->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 (route->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_put_route(route);

  	return 1;
}

#else	/* INET */

int ax25_hard_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, void *daddr, void *saddr, unsigned len)
{
	return -AX25_HEADER_LEN;
}

int ax25_rebuild_header(struct sk_buff *skb)
{
	return 1;
}

#endif

EXPORT_SYMBOL(ax25_hard_header);
EXPORT_SYMBOL(ax25_rebuild_header);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This program is free software; you can redistribute it and/or modify
	3	* it under the terms of the GNU General Public License as published by
	4	* the Free Software Foundation; either version 2 of the License, or
	5	* (at your option) any later version.
	6	*
	7	* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
	8	*/
	9	#include <linux/config.h>
	10	#include <linux/errno.h>
	11	#include <linux/types.h>
	12	#include <linux/socket.h>
	13	#include <linux/in.h>
	14	#include <linux/kernel.h>
70868eac	15	#include <linux/module.h>
1da177e4 LT	16	#include <linux/sched.h>
	17	#include <linux/timer.h>
	18	#include <linux/string.h>
	19	#include <linux/sockios.h>
	20	#include <linux/net.h>
	21	#include <net/ax25.h>
	22	#include <linux/inet.h>
	23	#include <linux/netdevice.h>
	24	#include <linux/if_arp.h>
	25	#include <linux/skbuff.h>
	26	#include <net/sock.h>
	27	#include <asm/uaccess.h>
	28	#include <asm/system.h>
	29	#include <linux/fcntl.h>
	30	#include <linux/termios.h> /* For TIOCINQ/OUTQ */
	31	#include <linux/mm.h>
	32	#include <linux/interrupt.h>
	33	#include <linux/notifier.h>
	34	#include <linux/proc_fs.h>
	35	#include <linux/stat.h>
	36	#include <linux/netfilter.h>
	37	#include <linux/sysctl.h>
	38	#include <net/ip.h>
	39	#include <net/arp.h>
	40
	41	/*
	42	* IP over AX.25 encapsulation.
	43	*/
	44
	45	/*
	46	* Shove an AX.25 UI header on an IP packet and handle ARP
	47	*/
	48
	49	#ifdef CONFIG_INET
	50
6f74998e	51	int ax25_hard_header(struct sk_buff skb, struct net_device dev, unsigned short type, void daddr, void saddr, unsigned len)
1da177e4 LT	52	{
	53	unsigned char *buff;
	54
	55	/* they sometimes come back to us... */
	56	if (type == ETH_P_AX25)
	57	return 0;
	58
	59	/* header is an AX.25 UI frame from us to them */
	60	buff = skb_push(skb, AX25_HEADER_LEN);
	61	buff++ = 0x00; / KISS DATA */
	62
	63	if (daddr != NULL)
	64	memcpy(buff, daddr, dev->addr_len); /* Address specified */
	65
	66	buff[6] &= ~AX25_CBIT;
	67	buff[6] &= ~AX25_EBIT;
	68	buff[6] \|= AX25_SSSID_SPARE;
	69	buff += AX25_ADDR_LEN;
	70
	71	if (saddr != NULL)
	72	memcpy(buff, saddr, dev->addr_len);
	73	else
	74	memcpy(buff, dev->dev_addr, dev->addr_len);
	75
	76	buff[6] &= ~AX25_CBIT;
	77	buff[6] \|= AX25_EBIT;
	78	buff[6] \|= AX25_SSSID_SPARE;
	79	buff += AX25_ADDR_LEN;
	80
	81	buff++ = AX25_UI; / UI */
	82
	83	/* Append a suitable AX.25 PID */
	84	switch (type) {
	85	case ETH_P_IP:
	86	*buff++ = AX25_P_IP;
	87	break;
	88	case ETH_P_ARP:
	89	*buff++ = AX25_P_ARP;
	90	break;
	91	default:
6f74998e	92	printk(KERN_ERR "AX.25: ax25_hard_header - wrong protocol type 0x%2.2x\n", type);
1da177e4 LT	93	*buff++ = 0;
	94	break;
	95	}
	96
	97	if (daddr != NULL)
	98	return AX25_HEADER_LEN;
	99
	100	return -AX25_HEADER_LEN; /* Unfinished header */
	101	}
	102
	103	int ax25_rebuild_header(struct sk_buff *skb)
	104	{
	105	struct sk_buff *ourskb;
	106	unsigned char *bp = skb->data;
	107	struct net_device *dev;
	108	ax25_address src, dst;
	109	ax25_dev *ax25_dev;
	110	ax25_route _route, *route = &_route;
	111	ax25_cb *ax25;
	112
	113	dst = (ax25_address *)(bp + 1);
	114	src = (ax25_address *)(bp + 8);
	115
	116	if (arp_find(bp + 1, skb))
	117	return 1;
	118
	119	route = ax25_rt_find_route(route, dst, NULL);
	120	dev = route->dev;
	121
	122	if (dev == NULL)
	123	dev = skb->dev;
	124
	125	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
	126	goto put;
	127	}
	128
	129	if (bp[16] == AX25_P_IP) {
	130	if (route->ip_mode == 'V' \|\| (route->ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) {
	131	/*
	132	* We copy the buffer and release the original thereby
	133	* keeping it straight
	134	*
	135	* Note: we report 1 back so the caller will
	136	* not feed the frame direct to the physical device
	137	* We don't want that to happen. (It won't be upset
	138	* as we have pulled the frame from the queue by
	139	* freeing it).
	140	*
	141	* NB: TCP modifies buffers that are still
	142	* on a device queue, thus we use skb_copy()
	143	* instead of using skb_clone() unless this
	144	* gets fixed.
	145	*/
	146
	147	ax25_address src_c;
	148	ax25_address dst_c;
	149
	150	if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) {
	151	kfree_skb(skb);
	152	goto put;
	153	}
	154
	155	if (skb->sk != NULL)
	156	skb_set_owner_w(ourskb, skb->sk);
157
158	kfree_skb(skb);
159	/* dl9sau: bugfix
160	* after kfree_skb(), dst and src which were pointer
161	* to bp which is part of skb->data would not be valid
162	* anymore hope that after skb_pull(ourskb, ..) our
163	* dsc_c and src_c will not become invalid
164	*/
165	bp = ourskb->data;
166	dst_c = (ax25_address )(bp + 1);
167	src_c = (ax25_address )(bp + 8);
168
169	skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */
170	ourskb->nh.raw = ourskb->data;
171
172	ax25=ax25_send_frame(
173	ourskb,
174	ax25_dev->values[AX25_VALUES_PACLEN],
175	&src_c,
176	&dst_c, route->digipeat, dev);
177	if (ax25) {
178	ax25_cb_put(ax25);
179	}
180	goto put;
181	}
182	}
183
184	bp[7] &= ~AX25_CBIT;
185	bp[7] &= ~AX25_EBIT;
186	bp[7] \|= AX25_SSSID_SPARE;
187
188	bp[14] &= ~AX25_CBIT;
189	bp[14] \|= AX25_EBIT;
190	bp[14] \|= AX25_SSSID_SPARE;
191
192	skb_pull(skb, AX25_KISS_HEADER_LEN);
193
194	if (route->digipeat != NULL) {
195	if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) {
196	kfree_skb(skb);
197	goto put;
198	}
199
200	skb = ourskb;
201	}
202
29c4be51	203	ax25_queue_xmit(skb, dev);
1da177e4 LT	204
	205	put:
	206	ax25_put_route(route);
	207
	208	return 1;
	209	}
	210
	211	#else /* INET */
	212
6f74998e	213	int ax25_hard_header(struct sk_buff skb, struct net_device dev, unsigned short type, void daddr, void saddr, unsigned len)
1da177e4 LT	214	{
	215	return -AX25_HEADER_LEN;
	216	}
	217
	218	int ax25_rebuild_header(struct sk_buff *skb)
	219	{
	220	return 1;
	221	}
	222
	223	#endif
	224
70868eac RB	225	EXPORT_SYMBOL(ax25_hard_header);
70868eac RB	226	EXPORT_SYMBOL(ax25_rebuild_header);