Release 4.14 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 */
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
211
90.95%
2
28.57%
Linus Torvalds
15
6.47%
1
14.29%
Stephen Hemminger
2
0.86%
1
14.29%
Ralf Bächle
2
0.86%
1
14.29%
Eric W. Biedermann
1
0.43%
1
14.29%
Eric Dumazet
1
0.43%
1
14.29%
Total
232
100.00%
7
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
318
72.11%
8
42.11%
Ralf Bächle
63
14.29%
3
15.79%
Thomas Osterried
27
6.12%
1
5.26%
Jeroen Vreeken
17
3.85%
1
5.26%
Eric W. Biedermann
10
2.27%
3
15.79%
Arnaldo Carvalho de Melo
5
1.13%
2
10.53%
Linus Torvalds
1
0.23%
1
5.26%
Total
441
100.00%
19
100.00%

#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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
33
86.84%
2
33.33%
Stephen Hemminger
2
5.26%
1
16.67%
Eric Dumazet
1
2.63%
1
16.67%
Ralf Bächle
1
2.63%
1
16.67%
Eric W. Biedermann
1
2.63%
1
16.67%
Total
38
100.00%
6
100.00%



netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
{
	kfree_skb(skb);
	return NETDEV_TX_OK;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Eric W. Biedermann
17
94.44%
2
66.67%
Fengguang Wu
1
5.56%
1
33.33%
Total
18
100.00%
3
100.00%

#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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Willem de Bruijn
59
100.00%
1
100.00%
Total
59
100.00%
1
100.00%


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);

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
650
71.35%
9
29.03%
Ralf Bächle
70
7.68%
6
19.35%
Willem de Bruijn
64
7.03%
1
3.23%
Eric W. Biedermann
34
3.73%
4
12.90%
Thomas Osterried
27
2.96%
1
3.23%
Stephen Hemminger
21
2.31%
1
3.23%
Jeroen Vreeken
17
1.87%
1
3.23%
Linus Torvalds
17
1.87%
3
9.68%
Arnaldo Carvalho de Melo
5
0.55%
2
6.45%
Tejun Heo
3
0.33%
1
3.23%
Eric Dumazet
2
0.22%
1
3.23%
Fengguang Wu
1
0.11%
1
3.23%
Total
911
100.00%
31
100.00%
Directory: net/ax25

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