Contributors: 13
	  
        
          | Author | 
          Tokens | 
          Token Proportion | 
          Commits | 
          Commit Proportion | 
        
	  
	  
        
        
          | Linus Torvalds (pre-git) | 
          643 | 
          71.29% | 
          9 | 
          28.12% | 
        
        
          | Willem de Bruijn | 
          64 | 
          7.10% | 
          1 | 
          3.12% | 
        
        
          | Ralf Baechle | 
          61 | 
          6.76% | 
          5 | 
          15.62% | 
        
        
          | Eric W. Biedermann | 
          34 | 
          3.77% | 
          4 | 
          12.50% | 
        
        
          | Thomas Osterried | 
          27 | 
          2.99% | 
          1 | 
          3.12% | 
        
        
          | Stephen Hemminger | 
          21 | 
          2.33% | 
          1 | 
          3.12% | 
        
        
          | Jeroen Vreeken | 
          17 | 
          1.88% | 
          1 | 
          3.12% | 
        
        
          | Linus Torvalds | 
          17 | 
          1.88% | 
          3 | 
          9.38% | 
        
        
          | Eric Dumazet | 
          7 | 
          0.78% | 
          2 | 
          6.25% | 
        
        
          | Arnaldo Carvalho de Melo | 
          5 | 
          0.55% | 
          2 | 
          6.25% | 
        
        
          | Tejun Heo | 
          3 | 
          0.33% | 
          1 | 
          3.12% | 
        
        
          | Thomas Gleixner | 
          2 | 
          0.22% | 
          1 | 
          3.12% | 
        
        
          | Fengguang Wu | 
          1 | 
          0.11% | 
          1 | 
          3.12% | 
        
	  
	  
        
          | Total | 
          902 | 
           | 
          32 | 
           | 
	    
	  
    
 
// 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)
			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);