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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 */
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>
14#include <linux/module.h>
15#include <linux/timer.h>
16#include <linux/string.h>
17#include <linux/sockios.h>
18#include <linux/net.h>
19#include <linux/slab.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
50int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
51 unsigned short type, const void *daddr,
52 const void *saddr, unsigned len)
53{
54 unsigned char *buff;
55
56 /* they sometimes come back to us... */
57 if (type == ETH_P_AX25)
58 return 0;
59
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 */
63
64 if (daddr != NULL)
65 memcpy(buff, daddr, dev->addr_len); /* Address specified */
66
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 }
97
98 if (daddr != NULL)
99 return AX25_HEADER_LEN;
100
101 return -AX25_HEADER_LEN; /* Unfinished header */
102}
103
104int ax25_rebuild_header(struct sk_buff *skb)
105{
106 struct sk_buff *ourskb;
107 unsigned char *bp = skb->data;
108 ax25_route *route;
109 struct net_device *dev = NULL;
110 ax25_address *src, *dst;
111 ax25_digi *digipeat = NULL;
112 ax25_dev *ax25_dev;
113 ax25_cb *ax25;
114 char ip_mode = ' ';
115
116 dst = (ax25_address *)(bp + 1);
117 src = (ax25_address *)(bp + 8);
118
119 if (arp_find(bp + 1, skb))
120 return 1;
121
122 route = ax25_get_route(dst, NULL);
123 if (route) {
124 digipeat = route->digipeat;
125 dev = route->dev;
126 ip_mode = route->ip_mode;
127 }
128
129 if (dev == NULL)
130 dev = skb->dev;
131
132 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
133 goto put;
134 }
135
136 if (bp[16] == AX25_P_IP) {
137 if (ip_mode == 'V' || (ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) {
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 */
177 skb_reset_network_header(ourskb);
178
179 ax25=ax25_send_frame(
180 ourskb,
181 ax25_dev->values[AX25_VALUES_PACLEN],
182 &src_c,
183 &dst_c, digipeat, dev);
184 if (ax25) {
185 ax25_cb_put(ax25);
186 }
187 goto put;
188 }
189 }
190
191 bp[7] &= ~AX25_CBIT;
192 bp[7] &= ~AX25_EBIT;
193 bp[7] |= AX25_SSSID_SPARE;
194
195 bp[14] &= ~AX25_CBIT;
196 bp[14] |= AX25_EBIT;
197 bp[14] |= AX25_SSSID_SPARE;
198
199 skb_pull(skb, AX25_KISS_HEADER_LEN);
200
201 if (digipeat != NULL) {
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
210 ax25_queue_xmit(skb, dev);
211
212put:
213 if (route)
214 ax25_put_route(route);
215
216 return 1;
217}
218
219#else /* INET */
220
221int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
222 unsigned short type, const void *daddr,
223 const void *saddr, unsigned len)
224{
225 return -AX25_HEADER_LEN;
226}
227
228int ax25_rebuild_header(struct sk_buff *skb)
229{
230 return 1;
231}
232
233#endif
234
235const struct header_ops ax25_header_ops = {
236 .create = ax25_hard_header,
237 .rebuild = ax25_rebuild_header,
238};
239
240EXPORT_SYMBOL(ax25_hard_header);
241EXPORT_SYMBOL(ax25_rebuild_header);
242EXPORT_SYMBOL(ax25_header_ops);
243
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
5 */
6#include <linux/errno.h>
7#include <linux/types.h>
8#include <linux/socket.h>
9#include <linux/in.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/timer.h>
13#include <linux/string.h>
14#include <linux/sockios.h>
15#include <linux/net.h>
16#include <linux/slab.h>
17#include <net/ax25.h>
18#include <linux/inet.h>
19#include <linux/netdevice.h>
20#include <linux/if_arp.h>
21#include <linux/skbuff.h>
22#include <net/sock.h>
23#include <linux/uaccess.h>
24#include <linux/fcntl.h>
25#include <linux/termios.h> /* For TIOCINQ/OUTQ */
26#include <linux/mm.h>
27#include <linux/interrupt.h>
28#include <linux/notifier.h>
29#include <linux/proc_fs.h>
30#include <linux/stat.h>
31#include <linux/sysctl.h>
32#include <net/ip.h>
33#include <net/arp.h>
34
35/*
36 * IP over AX.25 encapsulation.
37 */
38
39/*
40 * Shove an AX.25 UI header on an IP packet and handle ARP
41 */
42
43#ifdef CONFIG_INET
44
45static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
46 unsigned short type, const void *daddr,
47 const void *saddr, unsigned int len)
48{
49 unsigned char *buff;
50
51 /* they sometimes come back to us... */
52 if (type == ETH_P_AX25)
53 return 0;
54
55 /* header is an AX.25 UI frame from us to them */
56 buff = skb_push(skb, AX25_HEADER_LEN);
57 *buff++ = 0x00; /* KISS DATA */
58
59 if (daddr != NULL)
60 memcpy(buff, daddr, dev->addr_len); /* Address specified */
61
62 buff[6] &= ~AX25_CBIT;
63 buff[6] &= ~AX25_EBIT;
64 buff[6] |= AX25_SSSID_SPARE;
65 buff += AX25_ADDR_LEN;
66
67 if (saddr != NULL)
68 memcpy(buff, saddr, dev->addr_len);
69 else
70 memcpy(buff, dev->dev_addr, dev->addr_len);
71
72 buff[6] &= ~AX25_CBIT;
73 buff[6] |= AX25_EBIT;
74 buff[6] |= AX25_SSSID_SPARE;
75 buff += AX25_ADDR_LEN;
76
77 *buff++ = AX25_UI; /* UI */
78
79 /* Append a suitable AX.25 PID */
80 switch (type) {
81 case ETH_P_IP:
82 *buff++ = AX25_P_IP;
83 break;
84 case ETH_P_ARP:
85 *buff++ = AX25_P_ARP;
86 break;
87 default:
88 printk(KERN_ERR "AX.25: ax25_hard_header - wrong protocol type 0x%2.2x\n", type);
89 *buff++ = 0;
90 break;
91 }
92
93 if (daddr != NULL)
94 return AX25_HEADER_LEN;
95
96 return -AX25_HEADER_LEN; /* Unfinished header */
97}
98
99netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
100{
101 struct sk_buff *ourskb;
102 unsigned char *bp = skb->data;
103 ax25_route *route;
104 struct net_device *dev = NULL;
105 ax25_address *src, *dst;
106 ax25_digi *digipeat = NULL;
107 ax25_dev *ax25_dev;
108 ax25_cb *ax25;
109 char ip_mode = ' ';
110
111 dst = (ax25_address *)(bp + 1);
112 src = (ax25_address *)(bp + 8);
113
114 ax25_route_lock_use();
115 route = ax25_get_route(dst, NULL);
116 if (route) {
117 digipeat = route->digipeat;
118 dev = route->dev;
119 ip_mode = route->ip_mode;
120 }
121
122 if (dev == NULL)
123 dev = skb->dev;
124
125 rcu_read_lock();
126 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
127 kfree_skb(skb);
128 goto put;
129 }
130
131 if (bp[16] == AX25_P_IP) {
132 if (ip_mode == 'V' || (ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) {
133 /*
134 * We copy the buffer and release the original thereby
135 * keeping it straight
136 *
137 * Note: we report 1 back so the caller will
138 * not feed the frame direct to the physical device
139 * We don't want that to happen. (It won't be upset
140 * as we have pulled the frame from the queue by
141 * freeing it).
142 *
143 * NB: TCP modifies buffers that are still
144 * on a device queue, thus we use skb_copy()
145 * instead of using skb_clone() unless this
146 * gets fixed.
147 */
148
149 ax25_address src_c;
150 ax25_address dst_c;
151
152 if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) {
153 kfree_skb(skb);
154 goto put;
155 }
156
157 if (skb->sk != NULL)
158 skb_set_owner_w(ourskb, skb->sk);
159
160 kfree_skb(skb);
161 /* dl9sau: bugfix
162 * after kfree_skb(), dst and src which were pointer
163 * to bp which is part of skb->data would not be valid
164 * anymore hope that after skb_pull(ourskb, ..) our
165 * dsc_c and src_c will not become invalid
166 */
167 bp = ourskb->data;
168 dst_c = *(ax25_address *)(bp + 1);
169 src_c = *(ax25_address *)(bp + 8);
170
171 skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */
172 skb_reset_network_header(ourskb);
173
174 ax25=ax25_send_frame(
175 ourskb,
176 ax25_dev->values[AX25_VALUES_PACLEN],
177 &src_c,
178 &dst_c, digipeat, dev);
179 if (ax25) {
180 ax25_cb_put(ax25);
181 }
182 goto put;
183 }
184 }
185
186 bp[7] &= ~AX25_CBIT;
187 bp[7] &= ~AX25_EBIT;
188 bp[7] |= AX25_SSSID_SPARE;
189
190 bp[14] &= ~AX25_CBIT;
191 bp[14] |= AX25_EBIT;
192 bp[14] |= AX25_SSSID_SPARE;
193
194 skb_pull(skb, AX25_KISS_HEADER_LEN);
195
196 if (digipeat != NULL) {
197 if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL)
198 goto put;
199
200 skb = ourskb;
201 }
202
203 ax25_queue_xmit(skb, dev);
204
205put:
206 rcu_read_unlock();
207 ax25_route_lock_unuse();
208 return NETDEV_TX_OK;
209}
210
211#else /* INET */
212
213static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
214 unsigned short type, const void *daddr,
215 const void *saddr, unsigned int len)
216{
217 return -AX25_HEADER_LEN;
218}
219
220netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
221{
222 kfree_skb(skb);
223 return NETDEV_TX_OK;
224}
225#endif
226
227static bool ax25_validate_header(const char *header, unsigned int len)
228{
229 ax25_digi digi;
230
231 if (!len)
232 return false;
233
234 if (header[0])
235 return true;
236
237 return ax25_addr_parse(header + 1, len - 1, NULL, NULL, &digi, NULL,
238 NULL);
239}
240
241const struct header_ops ax25_header_ops = {
242 .create = ax25_hard_header,
243 .validate = ax25_validate_header,
244};
245
246EXPORT_SYMBOL(ax25_header_ops);
247EXPORT_SYMBOL(ax25_ip_xmit);