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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 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
126 kfree_skb(skb);
127 goto put;
128 }
129
130 if (bp[16] == AX25_P_IP) {
131 if (ip_mode == 'V' || (ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) {
132 /*
133 * We copy the buffer and release the original thereby
134 * keeping it straight
135 *
136 * Note: we report 1 back so the caller will
137 * not feed the frame direct to the physical device
138 * We don't want that to happen. (It won't be upset
139 * as we have pulled the frame from the queue by
140 * freeing it).
141 *
142 * NB: TCP modifies buffers that are still
143 * on a device queue, thus we use skb_copy()
144 * instead of using skb_clone() unless this
145 * gets fixed.
146 */
147
148 ax25_address src_c;
149 ax25_address dst_c;
150
151 if ((ourskb = skb_copy(skb, GFP_ATOMIC)) == NULL) {
152 kfree_skb(skb);
153 goto put;
154 }
155
156 if (skb->sk != NULL)
157 skb_set_owner_w(ourskb, skb->sk);
158
159 kfree_skb(skb);
160 /* dl9sau: bugfix
161 * after kfree_skb(), dst and src which were pointer
162 * to bp which is part of skb->data would not be valid
163 * anymore hope that after skb_pull(ourskb, ..) our
164 * dsc_c and src_c will not become invalid
165 */
166 bp = ourskb->data;
167 dst_c = *(ax25_address *)(bp + 1);
168 src_c = *(ax25_address *)(bp + 8);
169
170 skb_pull(ourskb, AX25_HEADER_LEN - 1); /* Keep PID */
171 skb_reset_network_header(ourskb);
172
173 ax25=ax25_send_frame(
174 ourskb,
175 ax25_dev->values[AX25_VALUES_PACLEN],
176 &src_c,
177 &dst_c, digipeat, dev);
178 if (ax25) {
179 ax25_cb_put(ax25);
180 }
181 goto put;
182 }
183 }
184
185 bp[7] &= ~AX25_CBIT;
186 bp[7] &= ~AX25_EBIT;
187 bp[7] |= AX25_SSSID_SPARE;
188
189 bp[14] &= ~AX25_CBIT;
190 bp[14] |= AX25_EBIT;
191 bp[14] |= AX25_SSSID_SPARE;
192
193 skb_pull(skb, AX25_KISS_HEADER_LEN);
194
195 if (digipeat != NULL) {
196 if ((ourskb = ax25_rt_build_path(skb, src, dst, route->digipeat)) == NULL) {
197 kfree_skb(skb);
198 goto put;
199 }
200
201 skb = ourskb;
202 }
203
204 ax25_queue_xmit(skb, dev);
205
206put:
207
208 ax25_route_lock_unuse();
209 return NETDEV_TX_OK;
210}
211
212#else /* INET */
213
214static int ax25_hard_header(struct sk_buff *skb, struct net_device *dev,
215 unsigned short type, const void *daddr,
216 const void *saddr, unsigned int len)
217{
218 return -AX25_HEADER_LEN;
219}
220
221netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
222{
223 kfree_skb(skb);
224 return NETDEV_TX_OK;
225}
226#endif
227
228static bool ax25_validate_header(const char *header, unsigned int len)
229{
230 ax25_digi digi;
231
232 if (!len)
233 return false;
234
235 if (header[0])
236 return true;
237
238 return ax25_addr_parse(header + 1, len - 1, NULL, NULL, &digi, NULL,
239 NULL);
240}
241
242const struct header_ops ax25_header_ops = {
243 .create = ax25_hard_header,
244 .validate = ax25_validate_header,
245};
246
247EXPORT_SYMBOL(ax25_header_ops);
248EXPORT_SYMBOL(ax25_ip_xmit);
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 <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/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
48static 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)
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:
91 printk(KERN_ERR "AX.25: ax25_hard_header - wrong protocol type 0x%2.2x\n", type);
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
102netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
103{
104 struct sk_buff *ourskb;
105 unsigned char *bp = skb->data;
106 ax25_route *route;
107 struct net_device *dev = NULL;
108 ax25_address *src, *dst;
109 ax25_digi *digipeat = NULL;
110 ax25_dev *ax25_dev;
111 ax25_cb *ax25;
112 char ip_mode = ' ';
113
114 dst = (ax25_address *)(bp + 1);
115 src = (ax25_address *)(bp + 8);
116
117 route = ax25_get_route(dst, NULL);
118 if (route) {
119 digipeat = route->digipeat;
120 dev = route->dev;
121 ip_mode = route->ip_mode;
122 }
123
124 if (dev == NULL)
125 dev = skb->dev;
126
127 if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL) {
128 kfree_skb(skb);
129 goto put;
130 }
131
132 if (bp[16] == AX25_P_IP) {
133 if (ip_mode == 'V' || (ip_mode == ' ' && ax25_dev->values[AX25_VALUES_IPDEFMODE])) {
134 /*
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 */
173 skb_reset_network_header(ourskb);
174
175 ax25=ax25_send_frame(
176 ourskb,
177 ax25_dev->values[AX25_VALUES_PACLEN],
178 &src_c,
179 &dst_c, digipeat, dev);
180 if (ax25) {
181 ax25_cb_put(ax25);
182 }
183 goto put;
184 }
185 }
186
187 bp[7] &= ~AX25_CBIT;
188 bp[7] &= ~AX25_EBIT;
189 bp[7] |= AX25_SSSID_SPARE;
190
191 bp[14] &= ~AX25_CBIT;
192 bp[14] |= AX25_EBIT;
193 bp[14] |= AX25_SSSID_SPARE;
194
195 skb_pull(skb, AX25_KISS_HEADER_LEN);
196
197 if (digipeat != NULL) {
198 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
206 ax25_queue_xmit(skb, dev);
207
208put:
209 if (route)
210 ax25_put_route(route);
211
212 return NETDEV_TX_OK;
213}
214
215#else /* INET */
216
217static 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)
220{
221 return -AX25_HEADER_LEN;
222}
223
224netdev_tx_t ax25_ip_xmit(struct sk_buff *skb)
225{
226 kfree_skb(skb);
227 return NETDEV_TX_OK;
228}
229#endif
230
231static 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
245const struct header_ops ax25_header_ops = {
246 .create = ax25_hard_header,
247 .validate = ax25_validate_header,
248};
249
250EXPORT_SYMBOL(ax25_header_ops);
251EXPORT_SYMBOL(ax25_ip_xmit);
252