1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
|
/*
* AX.25 release 037
*
* This code REQUIRES 2.1.15 or higher/ NET3.038
*
* This module:
* This module 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.
*
* History
* AX.25 036 Jonathan(G4KLX) Split from af_ax25.c.
*/
#include <linux/config.h>
#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.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/firewall.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_encapsulate(struct sk_buff *skb, struct device *dev, unsigned short type, void *daddr, void *saddr, unsigned len)
{
/* header is an AX.25 UI frame from us to them */
unsigned char *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_encapsulate - wrong protocol type 0x%x2.2\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 device *dev = skb->dev;
ax25_address *src, *dst;
ax25_route *route;
ax25_dev *ax25_dev;
dst = (ax25_address *)(bp + 1);
src = (ax25_address *)(bp + 8);
if (arp_find(bp + 1, skb))
return 1;
if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
return 1;
route = ax25_rt_find_route(dst, dev);
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.
*/
if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) {
kfree_skb(skb, FREE_WRITE);
return 1;
}
if (skb->sk != NULL)
skb_set_owner_w(ourskb, skb->sk);
kfree_skb(skb, FREE_WRITE);
skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */
ax25_send_frame(ourskb, ax25_dev->values[AX25_VALUES_PACLEN], src, dst, route->digipeat, dev);
return 1;
}
}
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;
if (route->digipeat != NULL) {
if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) {
kfree_skb(skb, FREE_WRITE);
return 1;
}
skb = ourskb;
}
skb->dev = dev;
skb->priority = SOPRI_NORMAL;
ax25_queue_xmit(skb);
return 1;
}
#endif
#endif
|
