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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/sched.h> |
16 | #include <linux/timer.h> | |
17 | #include <linux/string.h> | |
18 | #include <linux/sockios.h> | |
19 | #include <linux/net.h> | |
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 | ||
6f74998e | 50 | int ax25_hard_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, void *daddr, void *saddr, unsigned 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 | ||
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 */ | |
61 | ||
62 | if (daddr != NULL) | |
63 | memcpy(buff, daddr, dev->addr_len); /* Address specified */ | |
64 | ||
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: | |
6f74998e | 91 | printk(KERN_ERR "AX.25: ax25_hard_header - wrong protocol type 0x%2.2x\n", type); |
1da177e4 LT |
92 | *buff++ = 0; |
93 | break; | |
94 | } | |
95 | ||
96 | if (daddr != NULL) | |
97 | return AX25_HEADER_LEN; | |
98 | ||
99 | return -AX25_HEADER_LEN; /* Unfinished header */ | |
100 | } | |
101 | ||
102 | int ax25_rebuild_header(struct sk_buff *skb) | |
103 | { | |
104 | struct sk_buff *ourskb; | |
105 | unsigned char *bp = skb->data; | |
006f68b8 RBD |
106 | ax25_route *route; |
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 | ||
117 | if (arp_find(bp + 1, skb)) | |
118 | return 1; | |
119 | ||
006f68b8 RBD |
120 | route = ax25_get_route(dst, NULL); |
121 | if (route) { | |
122 | digipeat = route->digipeat; | |
123 | dev = route->dev; | |
124 | ip_mode = route->ip_mode; | |
125 | }; | |
1da177e4 LT |
126 | |
127 | if (dev == NULL) | |
128 | dev = skb->dev; | |
129 | ||
130 | if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) { | |
131 | goto put; | |
132 | } | |
133 | ||
134 | if (bp[16] == AX25_P_IP) { | |
006f68b8 | 135 | if (ip_mode == 'V' || (ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) { |
1da177e4 LT |
136 | /* |
137 | * We copy the buffer and release the original thereby | |
138 | * keeping it straight | |
139 | * | |
140 | * Note: we report 1 back so the caller will | |
141 | * not feed the frame direct to the physical device | |
142 | * We don't want that to happen. (It won't be upset | |
143 | * as we have pulled the frame from the queue by | |
144 | * freeing it). | |
145 | * | |
146 | * NB: TCP modifies buffers that are still | |
147 | * on a device queue, thus we use skb_copy() | |
148 | * instead of using skb_clone() unless this | |
149 | * gets fixed. | |
150 | */ | |
151 | ||
152 | ax25_address src_c; | |
153 | ax25_address dst_c; | |
154 | ||
155 | if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) { | |
156 | kfree_skb(skb); | |
157 | goto put; | |
158 | } | |
159 | ||
160 | if (skb->sk != NULL) | |
161 | skb_set_owner_w(ourskb, skb->sk); | |
162 | ||
163 | kfree_skb(skb); | |
164 | /* dl9sau: bugfix | |
165 | * after kfree_skb(), dst and src which were pointer | |
166 | * to bp which is part of skb->data would not be valid | |
167 | * anymore hope that after skb_pull(ourskb, ..) our | |
168 | * dsc_c and src_c will not become invalid | |
169 | */ | |
170 | bp = ourskb->data; | |
171 | dst_c = *(ax25_address *)(bp + 1); | |
172 | src_c = *(ax25_address *)(bp + 8); | |
173 | ||
174 | skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */ | |
175 | ourskb->nh.raw = ourskb->data; | |
176 | ||
177 | ax25=ax25_send_frame( | |
178 | ourskb, | |
179 | ax25_dev->values[AX25_VALUES_PACLEN], | |
180 | &src_c, | |
006f68b8 | 181 | &dst_c, digipeat, dev); |
1da177e4 LT |
182 | if (ax25) { |
183 | ax25_cb_put(ax25); | |
184 | } | |
185 | goto put; | |
186 | } | |
187 | } | |
188 | ||
189 | bp[7] &= ~AX25_CBIT; | |
190 | bp[7] &= ~AX25_EBIT; | |
191 | bp[7] |= AX25_SSSID_SPARE; | |
192 | ||
193 | bp[14] &= ~AX25_CBIT; | |
194 | bp[14] |= AX25_EBIT; | |
195 | bp[14] |= AX25_SSSID_SPARE; | |
196 | ||
197 | skb_pull(skb, AX25_KISS_HEADER_LEN); | |
198 | ||
006f68b8 | 199 | if (digipeat != NULL) { |
1da177e4 LT |
200 | if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) { |
201 | kfree_skb(skb); | |
202 | goto put; | |
203 | } | |
204 | ||
205 | skb = ourskb; | |
206 | } | |
207 | ||
29c4be51 | 208 | ax25_queue_xmit(skb, dev); |
1da177e4 LT |
209 | |
210 | put: | |
006f68b8 RBD |
211 | if (route) |
212 | ax25_put_route(route); | |
1da177e4 LT |
213 | |
214 | return 1; | |
215 | } | |
216 | ||
217 | #else /* INET */ | |
218 | ||
6f74998e | 219 | int ax25_hard_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, void *daddr, void *saddr, unsigned len) |
1da177e4 LT |
220 | { |
221 | return -AX25_HEADER_LEN; | |
222 | } | |
223 | ||
224 | int ax25_rebuild_header(struct sk_buff *skb) | |
225 | { | |
226 | return 1; | |
227 | } | |
228 | ||
229 | #endif | |
230 | ||
70868eac RB |
231 | EXPORT_SYMBOL(ax25_hard_header); |
232 | EXPORT_SYMBOL(ax25_rebuild_header); |