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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> | |
26 | #include <asm/uaccess.h> | |
27 | #include <asm/system.h> | |
28 | #include <linux/fcntl.h> | |
29 | #include <linux/termios.h> /* For TIOCINQ/OUTQ */ | |
30 | #include <linux/mm.h> | |
31 | #include <linux/interrupt.h> | |
32 | #include <linux/notifier.h> | |
33 | #include <linux/proc_fs.h> | |
34 | #include <linux/stat.h> | |
35 | #include <linux/netfilter.h> | |
36 | #include <linux/sysctl.h> | |
37 | #include <net/ip.h> | |
38 | #include <net/arp.h> | |
39 | ||
40 | /* | |
41 | * IP over AX.25 encapsulation. | |
42 | */ | |
43 | ||
44 | /* | |
45 | * Shove an AX.25 UI header on an IP packet and handle ARP | |
46 | */ | |
47 | ||
48 | #ifdef CONFIG_INET | |
49 | ||
3b04ddde SH |
50 | int ax25_hard_header(struct sk_buff *skb, struct net_device *dev, |
51 | unsigned short type, const void *daddr, | |
52 | const void *saddr, unsigned len) | |
1da177e4 LT |
53 | { |
54 | unsigned char *buff; | |
55 | ||
56 | /* they sometimes come back to us... */ | |
57 | if (type == ETH_P_AX25) | |
58 | return 0; | |
59 | ||
528930b9 YH |
60 | /* header is an AX.25 UI frame from us to them */ |
61 | buff = skb_push(skb, AX25_HEADER_LEN); | |
62 | *buff++ = 0x00; /* KISS DATA */ | |
1da177e4 LT |
63 | |
64 | if (daddr != NULL) | |
65 | memcpy(buff, daddr, dev->addr_len); /* Address specified */ | |
66 | ||
528930b9 YH |
67 | buff[6] &= ~AX25_CBIT; |
68 | buff[6] &= ~AX25_EBIT; | |
69 | buff[6] |= AX25_SSSID_SPARE; | |
70 | buff += AX25_ADDR_LEN; | |
71 | ||
72 | if (saddr != NULL) | |
73 | memcpy(buff, saddr, dev->addr_len); | |
74 | else | |
75 | memcpy(buff, dev->dev_addr, dev->addr_len); | |
76 | ||
77 | buff[6] &= ~AX25_CBIT; | |
78 | buff[6] |= AX25_EBIT; | |
79 | buff[6] |= AX25_SSSID_SPARE; | |
80 | buff += AX25_ADDR_LEN; | |
81 | ||
82 | *buff++ = AX25_UI; /* UI */ | |
83 | ||
84 | /* Append a suitable AX.25 PID */ | |
85 | switch (type) { | |
86 | case ETH_P_IP: | |
87 | *buff++ = AX25_P_IP; | |
88 | break; | |
89 | case ETH_P_ARP: | |
90 | *buff++ = AX25_P_ARP; | |
91 | break; | |
92 | default: | |
93 | printk(KERN_ERR "AX.25: ax25_hard_header - wrong protocol type 0x%2.2x\n", type); | |
94 | *buff++ = 0; | |
95 | break; | |
96 | } | |
1da177e4 LT |
97 | |
98 | if (daddr != NULL) | |
528930b9 | 99 | return AX25_HEADER_LEN; |
1da177e4 LT |
100 | |
101 | return -AX25_HEADER_LEN; /* Unfinished header */ | |
102 | } | |
103 | ||
104 | int ax25_rebuild_header(struct sk_buff *skb) | |
105 | { | |
106 | struct sk_buff *ourskb; | |
107 | unsigned char *bp = skb->data; | |
006f68b8 RBD |
108 | ax25_route *route; |
109 | struct net_device *dev = NULL; | |
1da177e4 | 110 | ax25_address *src, *dst; |
006f68b8 | 111 | ax25_digi *digipeat = NULL; |
1da177e4 | 112 | ax25_dev *ax25_dev; |
1da177e4 | 113 | ax25_cb *ax25; |
006f68b8 | 114 | char ip_mode = ' '; |
1da177e4 LT |
115 | |
116 | dst = (ax25_address *)(bp + 1); | |
117 | src = (ax25_address *)(bp + 8); | |
118 | ||
528930b9 YH |
119 | if (arp_find(bp + 1, skb)) |
120 | return 1; | |
1da177e4 | 121 | |
006f68b8 RBD |
122 | route = ax25_get_route(dst, NULL); |
123 | if (route) { | |
124 | digipeat = route->digipeat; | |
125 | dev = route->dev; | |
126 | ip_mode = route->ip_mode; | |
3ff50b79 | 127 | } |
1da177e4 LT |
128 | |
129 | if (dev == NULL) | |
130 | dev = skb->dev; | |
131 | ||
528930b9 YH |
132 | if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) { |
133 | goto put; | |
1da177e4 LT |
134 | } |
135 | ||
136 | if (bp[16] == AX25_P_IP) { | |
006f68b8 | 137 | if (ip_mode == 'V' || (ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) { |
1da177e4 LT |
138 | /* |
139 | * We copy the buffer and release the original thereby | |
140 | * keeping it straight | |
141 | * | |
142 | * Note: we report 1 back so the caller will | |
143 | * not feed the frame direct to the physical device | |
144 | * We don't want that to happen. (It won't be upset | |
145 | * as we have pulled the frame from the queue by | |
146 | * freeing it). | |
147 | * | |
148 | * NB: TCP modifies buffers that are still | |
149 | * on a device queue, thus we use skb_copy() | |
150 | * instead of using skb_clone() unless this | |
151 | * gets fixed. | |
152 | */ | |
153 | ||
154 | ax25_address src_c; | |
155 | ax25_address dst_c; | |
156 | ||
157 | if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) { | |
158 | kfree_skb(skb); | |
159 | goto put; | |
160 | } | |
161 | ||
162 | if (skb->sk != NULL) | |
163 | skb_set_owner_w(ourskb, skb->sk); | |
164 | ||
165 | kfree_skb(skb); | |
166 | /* dl9sau: bugfix | |
167 | * after kfree_skb(), dst and src which were pointer | |
168 | * to bp which is part of skb->data would not be valid | |
169 | * anymore hope that after skb_pull(ourskb, ..) our | |
170 | * dsc_c and src_c will not become invalid | |
171 | */ | |
172 | bp = ourskb->data; | |
173 | dst_c = *(ax25_address *)(bp + 1); | |
174 | src_c = *(ax25_address *)(bp + 8); | |
175 | ||
176 | skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */ | |
c1d2bbe1 | 177 | skb_reset_network_header(ourskb); |
1da177e4 LT |
178 | |
179 | ax25=ax25_send_frame( | |
528930b9 YH |
180 | ourskb, |
181 | ax25_dev->values[AX25_VALUES_PACLEN], | |
1da177e4 | 182 | &src_c, |
006f68b8 | 183 | &dst_c, digipeat, dev); |
1da177e4 LT |
184 | if (ax25) { |
185 | ax25_cb_put(ax25); | |
186 | } | |
187 | goto put; | |
188 | } | |
189 | } | |
190 | ||
528930b9 YH |
191 | bp[7] &= ~AX25_CBIT; |
192 | bp[7] &= ~AX25_EBIT; | |
193 | bp[7] |= AX25_SSSID_SPARE; | |
1da177e4 | 194 | |
528930b9 YH |
195 | bp[14] &= ~AX25_CBIT; |
196 | bp[14] |= AX25_EBIT; | |
197 | bp[14] |= AX25_SSSID_SPARE; | |
1da177e4 LT |
198 | |
199 | skb_pull(skb, AX25_KISS_HEADER_LEN); | |
200 | ||
006f68b8 | 201 | if (digipeat != NULL) { |
1da177e4 LT |
202 | if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) { |
203 | kfree_skb(skb); | |
204 | goto put; | |
205 | } | |
206 | ||
207 | skb = ourskb; | |
208 | } | |
209 | ||
29c4be51 | 210 | ax25_queue_xmit(skb, dev); |
1da177e4 LT |
211 | |
212 | put: | |
006f68b8 RBD |
213 | if (route) |
214 | ax25_put_route(route); | |
1da177e4 | 215 | |
528930b9 | 216 | return 1; |
1da177e4 LT |
217 | } |
218 | ||
219 | #else /* INET */ | |
220 | ||
3b04ddde SH |
221 | int ax25_hard_header(struct sk_buff *skb, struct net_device *dev, |
222 | unsigned short type, const void *daddr, | |
223 | const void *saddr, unsigned len) | |
1da177e4 LT |
224 | { |
225 | return -AX25_HEADER_LEN; | |
226 | } | |
227 | ||
228 | int ax25_rebuild_header(struct sk_buff *skb) | |
229 | { | |
230 | return 1; | |
231 | } | |
232 | ||
233 | #endif | |
234 | ||
3b04ddde SH |
235 | const struct header_ops ax25_header_ops = { |
236 | .create = ax25_hard_header, | |
237 | .rebuild = ax25_rebuild_header, | |
238 | }; | |
239 | ||
70868eac RB |
240 | EXPORT_SYMBOL(ax25_hard_header); |
241 | EXPORT_SYMBOL(ax25_rebuild_header); | |
3b04ddde SH |
242 | EXPORT_SYMBOL(ax25_header_ops); |
243 |