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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#include <linux/errno.h>
10#include <linux/types.h>
11#include <linux/socket.h>
12#include <linux/in.h>
13#include <linux/kernel.h>
Ralf Baechle70868ea2006-05-03 23:25:17 -070014#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/timer.h>
16#include <linux/string.h>
17#include <linux/sockios.h>
18#include <linux/net.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090019#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/fcntl.h>
28#include <linux/termios.h> /* For TIOCINQ/OUTQ */
29#include <linux/mm.h>
30#include <linux/interrupt.h>
31#include <linux/notifier.h>
32#include <linux/proc_fs.h>
33#include <linux/stat.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/sysctl.h>
35#include <net/ip.h>
36#include <net/arp.h>
37
38/*
39 * IP over AX.25 encapsulation.
40 */
41
42/*
43 * Shove an AX.25 UI header on an IP packet and handle ARP
44 */
45
46#ifdef CONFIG_INET
47
Eric W. Biederman46d4e472015-03-02 00:04:31 -060048static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
49 unsigned short type, const void *daddr,
50 const void *saddr, unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -070051{
52 unsigned char *buff;
53
54 /* they sometimes come back to us... */
55 if (type == ETH_P_AX25)
56 return 0;
57
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090058 /* header is an AX.25 UI frame from us to them */
59 buff = skb_push(skb, AX25_HEADER_LEN);
60 *buff++ = 0x00; /* KISS DATA */
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
62 if (daddr != NULL)
63 memcpy(buff, daddr, dev->addr_len); /* Address specified */
64
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090065 buff[6] &= ~AX25_CBIT;
66 buff[6] &= ~AX25_EBIT;
67 buff[6] |= AX25_SSSID_SPARE;
68 buff += AX25_ADDR_LEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090070 if (saddr != NULL)
71 memcpy(buff, saddr, dev->addr_len);
72 else
73 memcpy(buff, dev->dev_addr, dev->addr_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090075 buff[6] &= ~AX25_CBIT;
76 buff[6] |= AX25_EBIT;
77 buff[6] |= AX25_SSSID_SPARE;
78 buff += AX25_ADDR_LEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090080 *buff++ = AX25_UI; /* UI */
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090082 /* 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:
91 printk(KERN_ERR "AX.25: ax25_hard_header - wrong protocol type 0x%2.2x\n", type);
92 *buff++ = 0;
93 break;
94 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
96 if (daddr != NULL)
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090097 return AX25_HEADER_LEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
99 return -AX25_HEADER_LEN; /* Unfinished header */
100}
101
Eric W. Biederman1d5da752015-03-03 09:41:47 -0600102netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103{
104 struct sk_buff *ourskb;
105 unsigned char *bp = skb->data;
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700106 ax25_route *route;
107 struct net_device *dev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 ax25_address *src, *dst;
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700109 ax25_digi *digipeat = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 ax25_dev *ax25_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 ax25_cb *ax25;
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700112 char ip_mode = ' ';
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113
114 dst = (ax25_address *)(bp + 1);
115 src = (ax25_address *)(bp + 8);
116
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700117 route = ax25_get_route(dst, NULL);
118 if (route) {
119 digipeat = route->digipeat;
120 dev = route->dev;
121 ip_mode = route->ip_mode;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700122 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
124 if (dev == NULL)
125 dev = skb->dev;
126
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +0900127 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
Eric W. Biedermane18dbd02015-03-01 23:59:57 -0600128 kfree_skb(skb);
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +0900129 goto put;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 }
131
132 if (bp[16] == AX25_P_IP) {
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700133 if (ip_mode == 'V' || (ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 /*
135 * We copy the buffer and release the original thereby
136 * keeping it straight
137 *
138 * Note: we report 1 back so the caller will
139 * not feed the frame direct to the physical device
140 * We don't want that to happen. (It won't be upset
141 * as we have pulled the frame from the queue by
142 * freeing it).
143 *
144 * NB: TCP modifies buffers that are still
145 * on a device queue, thus we use skb_copy()
146 * instead of using skb_clone() unless this
147 * gets fixed.
148 */
149
150 ax25_address src_c;
151 ax25_address dst_c;
152
153 if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) {
154 kfree_skb(skb);
155 goto put;
156 }
157
158 if (skb->sk != NULL)
159 skb_set_owner_w(ourskb, skb->sk);
160
161 kfree_skb(skb);
162 /* dl9sau: bugfix
163 * after kfree_skb(), dst and src which were pointer
164 * to bp which is part of skb->data would not be valid
165 * anymore hope that after skb_pull(ourskb, ..) our
166 * dsc_c and src_c will not become invalid
167 */
168 bp = ourskb->data;
169 dst_c = *(ax25_address *)(bp + 1);
170 src_c = *(ax25_address *)(bp + 8);
171
172 skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700173 skb_reset_network_header(ourskb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174
175 ax25=ax25_send_frame(
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +0900176 ourskb,
177 ax25_dev->values[AX25_VALUES_PACLEN],
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 &src_c,
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700179 &dst_c, digipeat, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 if (ax25) {
181 ax25_cb_put(ax25);
182 }
183 goto put;
184 }
185 }
186
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +0900187 bp[7] &= ~AX25_CBIT;
188 bp[7] &= ~AX25_EBIT;
189 bp[7] |= AX25_SSSID_SPARE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +0900191 bp[14] &= ~AX25_CBIT;
192 bp[14] |= AX25_EBIT;
193 bp[14] |= AX25_SSSID_SPARE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
195 skb_pull(skb, AX25_KISS_HEADER_LEN);
196
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700197 if (digipeat != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) {
199 kfree_skb(skb);
200 goto put;
201 }
202
203 skb = ourskb;
204 }
205
Arnaldo Carvalho de Melo29c4be52005-04-21 16:46:56 -0700206 ax25_queue_xmit(skb, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207
208put:
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700209 if (route)
210 ax25_put_route(route);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
Eric W. Biederman1d5da752015-03-03 09:41:47 -0600212 return NETDEV_TX_OK;
Eric W. Biederman3b6a94b2015-03-02 00:05:28 -0600213}
214
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215#else /* INET */
216
Eric W. Biederman46d4e472015-03-02 00:04:31 -0600217static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
218 unsigned short type, const void *daddr,
219 const void *saddr, unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220{
221 return -AX25_HEADER_LEN;
222}
223
kbuild test robot787fb2b2015-03-05 06:54:00 -0600224netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
Eric W. Biederman3b6a94b2015-03-02 00:05:28 -0600225{
Eric W. Biederman1d5da752015-03-03 09:41:47 -0600226 kfree_skb(skb);
227 return NETDEV_TX_OK;
Eric W. Biederman3b6a94b2015-03-02 00:05:28 -0600228}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229#endif
230
Willem de Bruijnea477812016-03-09 21:58:33 -0500231static bool ax25_validate_header(const char *header, unsigned int len)
232{
233 ax25_digi digi;
234
235 if (!len)
236 return false;
237
238 if (header[0])
239 return true;
240
241 return ax25_addr_parse(header + 1, len - 1, NULL, NULL, &digi, NULL,
242 NULL);
243}
244
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700245const struct header_ops ax25_header_ops = {
246 .create = ax25_hard_header,
Willem de Bruijnea477812016-03-09 21:58:33 -0500247 .validate = ax25_validate_header,
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700248};
249
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700250EXPORT_SYMBOL(ax25_header_ops);
Eric W. Biederman1d5da752015-03-03 09:41:47 -0600251EXPORT_SYMBOL(ax25_ip_xmit);
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700252