[linux-block.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/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);
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	*/
1da177e4 LT	9	#include <linux/errno.h>
	10	#include <linux/types.h>
	11	#include <linux/socket.h>
	12	#include <linux/in.h>
	13	#include <linux/kernel.h>
70868eac	14	#include <linux/module.h>
1da177e4 LT	15	#include <linux/timer.h>
	16	#include <linux/string.h>
	17	#include <linux/sockios.h>
	18	#include <linux/net.h>
5a0e3ad6	19	#include <linux/slab.h>
1da177e4 LT	20	#include <net/ax25.h>
	21	#include <linux/inet.h>
	22	#include <linux/netdevice.h>
	23	#include <linux/if_arp.h>
	24	#include <linux/skbuff.h>
	25	#include <net/sock.h>
7c0f6ba6	26	#include <linux/uaccess.h>
1da177e4 LT	27	#include <linux/fcntl.h>
	28	#include <linux/termios.h> /* For TIOCINQ/OUTQ */
	29	#include <linux/mm.h>
	30	#include <linux/interrupt.h>
	31	#include <linux/notifier.h>
	32	#include <linux/proc_fs.h>
	33	#include <linux/stat.h>
1da177e4 LT	34	#include <linux/sysctl.h>
	35	#include <net/ip.h>
	36	#include <net/arp.h>
	37
	38	/*
	39	* IP over AX.25 encapsulation.
	40	*/
	41
	42	/*
	43	* Shove an AX.25 UI header on an IP packet and handle ARP
	44	*/
	45
	46	#ifdef CONFIG_INET
	47
46d4e47a EB	48	static int ax25_hard_header(struct sk_buff skb, struct net_device dev,
	49	unsigned short type, const void *daddr,
	50	const void *saddr, unsigned int len)
1da177e4 LT	51	{
	52	unsigned char *buff;
	53
	54	/* they sometimes come back to us... */
	55	if (type == ETH_P_AX25)
	56	return 0;
	57
528930b9 YH	58	/* header is an AX.25 UI frame from us to them */
	59	buff = skb_push(skb, AX25_HEADER_LEN);
	60	buff++ = 0x00; / KISS DATA */
1da177e4 LT	61
	62	if (daddr != NULL)
	63	memcpy(buff, daddr, dev->addr_len); /* Address specified */
	64
528930b9 YH	65	buff[6] &= ~AX25_CBIT;
	66	buff[6] &= ~AX25_EBIT;
	67	buff[6] \|= AX25_SSSID_SPARE;
	68	buff += AX25_ADDR_LEN;
	69
	70	if (saddr != NULL)
	71	memcpy(buff, saddr, dev->addr_len);
	72	else
	73	memcpy(buff, dev->dev_addr, dev->addr_len);
	74
	75	buff[6] &= ~AX25_CBIT;
	76	buff[6] \|= AX25_EBIT;
	77	buff[6] \|= AX25_SSSID_SPARE;
	78	buff += AX25_ADDR_LEN;
	79
	80	buff++ = AX25_UI; / UI */
	81
	82	/* Append a suitable AX.25 PID */
	83	switch (type) {
	84	case ETH_P_IP:
	85	*buff++ = AX25_P_IP;
	86	break;
	87	case ETH_P_ARP:
	88	*buff++ = AX25_P_ARP;
	89	break;
	90	default:
	91	printk(KERN_ERR "AX.25: ax25_hard_header - wrong protocol type 0x%2.2x\n", type);
	92	*buff++ = 0;
	93	break;
	94	}
1da177e4 LT	95
1da177e4 LT	96	if (daddr != NULL)
528930b9	97	return AX25_HEADER_LEN;
1da177e4 LT	98
	99	return -AX25_HEADER_LEN; /* Unfinished header */
	100	}
	101
1d5da757	102	netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
1da177e4 LT	103	{
	104	struct sk_buff *ourskb;
	105	unsigned char *bp = skb->data;
006f68b8 RBD	106	ax25_route *route;
006f68b8 RBD	107	struct net_device *dev = NULL;
1da177e4	108	ax25_address src, dst;
006f68b8	109	ax25_digi *digipeat = NULL;
1da177e4	110	ax25_dev *ax25_dev;
1da177e4	111	ax25_cb *ax25;
006f68b8	112	char ip_mode = ' ';
1da177e4 LT	113
	114	dst = (ax25_address *)(bp + 1);
	115	src = (ax25_address *)(bp + 8);
	116
63530aba	117	ax25_route_lock_use();
006f68b8 RBD	118	route = ax25_get_route(dst, NULL);
	119	if (route) {
	120	digipeat = route->digipeat;
	121	dev = route->dev;
	122	ip_mode = route->ip_mode;
3ff50b79	123	}
1da177e4 LT	124
	125	if (dev == NULL)
	126	dev = skb->dev;
	127
528930b9	128	if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
e18dbd05	129	kfree_skb(skb);
528930b9	130	goto put;
1da177e4 LT	131	}
	132
	133	if (bp[16] == AX25_P_IP) {
006f68b8	134	if (ip_mode == 'V' \|\| (ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) {
1da177e4 LT	135	/*
	136	* We copy the buffer and release the original thereby
	137	* keeping it straight
	138	*
	139	* Note: we report 1 back so the caller will
	140	* not feed the frame direct to the physical device
	141	* We don't want that to happen. (It won't be upset
	142	* as we have pulled the frame from the queue by
	143	* freeing it).
	144	*
	145	* NB: TCP modifies buffers that are still
	146	* on a device queue, thus we use skb_copy()
	147	* instead of using skb_clone() unless this
	148	* gets fixed.
	149	*/
	150
	151	ax25_address src_c;
	152	ax25_address dst_c;
	153
	154	if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) {
	155	kfree_skb(skb);
	156	goto put;
	157	}
	158
	159	if (skb->sk != NULL)
	160	skb_set_owner_w(ourskb, skb->sk);
	161
	162	kfree_skb(skb);
	163	/* dl9sau: bugfix
	164	* after kfree_skb(), dst and src which were pointer
	165	* to bp which is part of skb->data would not be valid
	166	* anymore hope that after skb_pull(ourskb, ..) our
	167	* dsc_c and src_c will not become invalid
	168	*/
	169	bp = ourskb->data;
	170	dst_c = (ax25_address )(bp + 1);
	171	src_c = (ax25_address )(bp + 8);
	172
	173	skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */
c1d2bbe1	174	skb_reset_network_header(ourskb);
1da177e4 LT	175
1da177e4 LT	176	ax25=ax25_send_frame(
528930b9 YH	177	ourskb,
528930b9 YH	178	ax25_dev->values[AX25_VALUES_PACLEN],
1da177e4	179	&src_c,
006f68b8	180	&dst_c, digipeat, dev);
1da177e4 LT	181	if (ax25) {
	182	ax25_cb_put(ax25);
	183	}
	184	goto put;
	185	}
	186	}
	187
528930b9 YH	188	bp[7] &= ~AX25_CBIT;
	189	bp[7] &= ~AX25_EBIT;
	190	bp[7] \|= AX25_SSSID_SPARE;
1da177e4	191
528930b9 YH	192	bp[14] &= ~AX25_CBIT;
	193	bp[14] \|= AX25_EBIT;
	194	bp[14] \|= AX25_SSSID_SPARE;
1da177e4 LT	195
	196	skb_pull(skb, AX25_KISS_HEADER_LEN);
	197
006f68b8	198	if (digipeat != NULL) {
1da177e4 LT	199	if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) {
	200	kfree_skb(skb);
	201	goto put;
	202	}
	203
	204	skb = ourskb;
	205	}
	206
29c4be51	207	ax25_queue_xmit(skb, dev);
1da177e4 LT	208
1da177e4 LT	209	put:
1da177e4	210
63530aba	211	ax25_route_lock_unuse();
1d5da757	212	return NETDEV_TX_OK;
3b6a94be EB	213	}
3b6a94be EB	214
1da177e4 LT	215	#else /* INET */
1da177e4 LT	216
46d4e47a EB	217	static int ax25_hard_header(struct sk_buff skb, struct net_device dev,
	218	unsigned short type, const void *daddr,
	219	const void *saddr, unsigned int len)
1da177e4 LT	220	{
	221	return -AX25_HEADER_LEN;
	222	}
	223
787fb2bd	224	netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
3b6a94be	225	{
1d5da757 EB	226	kfree_skb(skb);
1d5da757 EB	227	return NETDEV_TX_OK;
3b6a94be	228	}
1da177e4 LT	229	#endif
1da177e4 LT	230
ea47781c WB	231	static bool ax25_validate_header(const char *header, unsigned int len)
	232	{
	233	ax25_digi digi;
	234
	235	if (!len)
	236	return false;
	237
	238	if (header[0])
	239	return true;
	240
	241	return ax25_addr_parse(header + 1, len - 1, NULL, NULL, &digi, NULL,
	242	NULL);
	243	}
	244
3b04ddde SH	245	const struct header_ops ax25_header_ops = {
3b04ddde SH	246	.create = ax25_hard_header,
ea47781c	247	.validate = ax25_validate_header,
3b04ddde SH	248	};
3b04ddde SH	249
3b04ddde	250	EXPORT_SYMBOL(ax25_header_ops);
1d5da757	251	EXPORT_SYMBOL(ax25_ip_xmit);