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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>
34#include <linux/netfilter.h>
35#include <linux/sysctl.h>
36#include <net/ip.h>
37#include <net/arp.h>
38
39/*
40 * IP over AX.25 encapsulation.
41 */
42
43/*
44 * Shove an AX.25 UI header on an IP packet and handle ARP
45 */
46
47#ifdef CONFIG_INET
48
Eric W. Biederman46d4e472015-03-02 00:04:31 -060049static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
50 unsigned short type, const void *daddr,
51 const void *saddr, unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052{
53 unsigned char *buff;
54
55 /* they sometimes come back to us... */
56 if (type == ETH_P_AX25)
57 return 0;
58
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090059 /* header is an AX.25 UI frame from us to them */
60 buff = skb_push(skb, AX25_HEADER_LEN);
61 *buff++ = 0x00; /* KISS DATA */
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
63 if (daddr != NULL)
64 memcpy(buff, daddr, dev->addr_len); /* Address specified */
65
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090066 buff[6] &= ~AX25_CBIT;
67 buff[6] &= ~AX25_EBIT;
68 buff[6] |= AX25_SSSID_SPARE;
69 buff += AX25_ADDR_LEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090071 if (saddr != NULL)
72 memcpy(buff, saddr, dev->addr_len);
73 else
74 memcpy(buff, dev->dev_addr, dev->addr_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090076 buff[6] &= ~AX25_CBIT;
77 buff[6] |= AX25_EBIT;
78 buff[6] |= AX25_SSSID_SPARE;
79 buff += AX25_ADDR_LEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090081 *buff++ = AX25_UI; /* UI */
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090083 /* Append a suitable AX.25 PID */
84 switch (type) {
85 case ETH_P_IP:
86 *buff++ = AX25_P_IP;
87 break;
88 case ETH_P_ARP:
89 *buff++ = AX25_P_ARP;
90 break;
91 default:
92 printk(KERN_ERR "AX.25: ax25_hard_header - wrong protocol type 0x%2.2x\n", type);
93 *buff++ = 0;
94 break;
95 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97 if (daddr != NULL)
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +090098 return AX25_HEADER_LEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099
100 return -AX25_HEADER_LEN; /* Unfinished header */
101}
102
Eric W. Biederman1d5da752015-03-03 09:41:47 -0600103netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104{
105 struct sk_buff *ourskb;
106 unsigned char *bp = skb->data;
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700107 ax25_route *route;
108 struct net_device *dev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 ax25_address *src, *dst;
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700110 ax25_digi *digipeat = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 ax25_dev *ax25_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 ax25_cb *ax25;
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700113 char ip_mode = ' ';
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
115 dst = (ax25_address *)(bp + 1);
116 src = (ax25_address *)(bp + 8);
117
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700118 route = ax25_get_route(dst, NULL);
119 if (route) {
120 digipeat = route->digipeat;
121 dev = route->dev;
122 ip_mode = route->ip_mode;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700123 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
125 if (dev == NULL)
126 dev = skb->dev;
127
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +0900128 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
Eric W. Biedermane18dbd02015-03-01 23:59:57 -0600129 kfree_skb(skb);
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +0900130 goto put;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 }
132
133 if (bp[16] == AX25_P_IP) {
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700134 if (ip_mode == 'V' || (ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 /*
136 * We copy the buffer and release the original thereby
137 * keeping it straight
138 *
139 * Note: we report 1 back so the caller will
140 * not feed the frame direct to the physical device
141 * We don't want that to happen. (It won't be upset
142 * as we have pulled the frame from the queue by
143 * freeing it).
144 *
145 * NB: TCP modifies buffers that are still
146 * on a device queue, thus we use skb_copy()
147 * instead of using skb_clone() unless this
148 * gets fixed.
149 */
150
151 ax25_address src_c;
152 ax25_address dst_c;
153
154 if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) {
155 kfree_skb(skb);
156 goto put;
157 }
158
159 if (skb->sk != NULL)
160 skb_set_owner_w(ourskb, skb->sk);
161
162 kfree_skb(skb);
163 /* dl9sau: bugfix
164 * after kfree_skb(), dst and src which were pointer
165 * to bp which is part of skb->data would not be valid
166 * anymore hope that after skb_pull(ourskb, ..) our
167 * dsc_c and src_c will not become invalid
168 */
169 bp = ourskb->data;
170 dst_c = *(ax25_address *)(bp + 1);
171 src_c = *(ax25_address *)(bp + 8);
172
173 skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -0700174 skb_reset_network_header(ourskb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
176 ax25=ax25_send_frame(
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +0900177 ourskb,
178 ax25_dev->values[AX25_VALUES_PACLEN],
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 &src_c,
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700180 &dst_c, digipeat, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 if (ax25) {
182 ax25_cb_put(ax25);
183 }
184 goto put;
185 }
186 }
187
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +0900188 bp[7] &= ~AX25_CBIT;
189 bp[7] &= ~AX25_EBIT;
190 bp[7] |= AX25_SSSID_SPARE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
YOSHIFUJI Hideaki528930b2007-02-09 23:24:31 +0900192 bp[14] &= ~AX25_CBIT;
193 bp[14] |= AX25_EBIT;
194 bp[14] |= AX25_SSSID_SPARE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
196 skb_pull(skb, AX25_KISS_HEADER_LEN);
197
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700198 if (digipeat != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) {
200 kfree_skb(skb);
201 goto put;
202 }
203
204 skb = ourskb;
205 }
206
Arnaldo Carvalho de Melo29c4be52005-04-21 16:46:56 -0700207 ax25_queue_xmit(skb, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
209put:
Ralf Baechle DL5RB006f68b2006-07-03 19:30:18 -0700210 if (route)
211 ax25_put_route(route);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212
Eric W. Biederman1d5da752015-03-03 09:41:47 -0600213 return NETDEV_TX_OK;
Eric W. Biederman3b6a94b2015-03-02 00:05:28 -0600214}
215
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216#else /* INET */
217
Eric W. Biederman46d4e472015-03-02 00:04:31 -0600218static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
219 unsigned short type, const void *daddr,
220 const void *saddr, unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221{
222 return -AX25_HEADER_LEN;
223}
224
kbuild test robot787fb2b2015-03-05 06:54:00 -0600225netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
Eric W. Biederman3b6a94b2015-03-02 00:05:28 -0600226{
Eric W. Biederman1d5da752015-03-03 09:41:47 -0600227 kfree_skb(skb);
228 return NETDEV_TX_OK;
Eric W. Biederman3b6a94b2015-03-02 00:05:28 -0600229}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230#endif
231
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700232const struct header_ops ax25_header_ops = {
233 .create = ax25_hard_header,
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700234};
235
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700236EXPORT_SYMBOL(ax25_header_ops);
Eric W. Biederman1d5da752015-03-03 09:41:47 -0600237EXPORT_SYMBOL(ax25_ip_xmit);
Stephen Hemminger3b04ddd2007-10-09 01:40:57 -0700238