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16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/errno.h>
19#include <linux/types.h>
20#include <linux/socket.h>
21#include <linux/in.h>
22#include <linux/kernel.h>
23#include <linux/timer.h>
24#include <linux/string.h>
25#include <linux/sockios.h>
26#include <linux/net.h>
27#include <linux/inet.h>
28#include <linux/skbuff.h>
29#include <linux/slab.h>
30#include <net/sock.h>
31#include <asm/uaccess.h>
32#include <linux/fcntl.h>
33#include <linux/mm.h>
34#include <linux/interrupt.h>
35#include <net/lapb.h>
36
37
38
39
40void lapb_clear_queues(struct lapb_cb *lapb)
41{
42 skb_queue_purge(&lapb->write_queue);
43 skb_queue_purge(&lapb->ack_queue);
44}
45
46
47
48
49
50
51void lapb_frames_acked(struct lapb_cb *lapb, unsigned short nr)
52{
53 struct sk_buff *skb;
54 int modulus;
55
56 modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
57
58
59
60
61 if (lapb->va != nr)
62 while (skb_peek(&lapb->ack_queue) && lapb->va != nr) {
63 skb = skb_dequeue(&lapb->ack_queue);
64 kfree_skb(skb);
65 lapb->va = (lapb->va + 1) % modulus;
66 }
67}
68
69void lapb_requeue_frames(struct lapb_cb *lapb)
70{
71 struct sk_buff *skb, *skb_prev = NULL;
72
73
74
75
76
77
78 while ((skb = skb_dequeue(&lapb->ack_queue)) != NULL) {
79 if (!skb_prev)
80 skb_queue_head(&lapb->write_queue, skb);
81 else
82 skb_append(skb_prev, skb, &lapb->write_queue);
83 skb_prev = skb;
84 }
85}
86
87
88
89
90
91int lapb_validate_nr(struct lapb_cb *lapb, unsigned short nr)
92{
93 unsigned short vc = lapb->va;
94 int modulus;
95
96 modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
97
98 while (vc != lapb->vs) {
99 if (nr == vc)
100 return 1;
101 vc = (vc + 1) % modulus;
102 }
103
104 return nr == lapb->vs;
105}
106
107
108
109
110
111int lapb_decode(struct lapb_cb *lapb, struct sk_buff *skb,
112 struct lapb_frame *frame)
113{
114 frame->type = LAPB_ILLEGAL;
115
116 lapb_dbg(2, "(%p) S%d RX %02X %02X %02X\n",
117 lapb->dev, lapb->state,
118 skb->data[0], skb->data[1], skb->data[2]);
119
120
121
122
123 if (!pskb_may_pull(skb, 2))
124 return -1;
125
126 if (lapb->mode & LAPB_MLP) {
127 if (lapb->mode & LAPB_DCE) {
128 if (skb->data[0] == LAPB_ADDR_D)
129 frame->cr = LAPB_COMMAND;
130 if (skb->data[0] == LAPB_ADDR_C)
131 frame->cr = LAPB_RESPONSE;
132 } else {
133 if (skb->data[0] == LAPB_ADDR_C)
134 frame->cr = LAPB_COMMAND;
135 if (skb->data[0] == LAPB_ADDR_D)
136 frame->cr = LAPB_RESPONSE;
137 }
138 } else {
139 if (lapb->mode & LAPB_DCE) {
140 if (skb->data[0] == LAPB_ADDR_B)
141 frame->cr = LAPB_COMMAND;
142 if (skb->data[0] == LAPB_ADDR_A)
143 frame->cr = LAPB_RESPONSE;
144 } else {
145 if (skb->data[0] == LAPB_ADDR_A)
146 frame->cr = LAPB_COMMAND;
147 if (skb->data[0] == LAPB_ADDR_B)
148 frame->cr = LAPB_RESPONSE;
149 }
150 }
151
152 skb_pull(skb, 1);
153
154 if (lapb->mode & LAPB_EXTENDED) {
155 if (!(skb->data[0] & LAPB_S)) {
156 if (!pskb_may_pull(skb, 2))
157 return -1;
158
159
160
161 frame->type = LAPB_I;
162 frame->ns = (skb->data[0] >> 1) & 0x7F;
163 frame->nr = (skb->data[1] >> 1) & 0x7F;
164 frame->pf = skb->data[1] & LAPB_EPF;
165 frame->control[0] = skb->data[0];
166 frame->control[1] = skb->data[1];
167 skb_pull(skb, 2);
168 } else if ((skb->data[0] & LAPB_U) == 1) {
169 if (!pskb_may_pull(skb, 2))
170 return -1;
171
172
173
174 frame->type = skb->data[0] & 0x0F;
175 frame->nr = (skb->data[1] >> 1) & 0x7F;
176 frame->pf = skb->data[1] & LAPB_EPF;
177 frame->control[0] = skb->data[0];
178 frame->control[1] = skb->data[1];
179 skb_pull(skb, 2);
180 } else if ((skb->data[0] & LAPB_U) == 3) {
181
182
183
184 frame->type = skb->data[0] & ~LAPB_SPF;
185 frame->pf = skb->data[0] & LAPB_SPF;
186 frame->control[0] = skb->data[0];
187 frame->control[1] = 0x00;
188 skb_pull(skb, 1);
189 }
190 } else {
191 if (!(skb->data[0] & LAPB_S)) {
192
193
194
195 frame->type = LAPB_I;
196 frame->ns = (skb->data[0] >> 1) & 0x07;
197 frame->nr = (skb->data[0] >> 5) & 0x07;
198 frame->pf = skb->data[0] & LAPB_SPF;
199 } else if ((skb->data[0] & LAPB_U) == 1) {
200
201
202
203 frame->type = skb->data[0] & 0x0F;
204 frame->nr = (skb->data[0] >> 5) & 0x07;
205 frame->pf = skb->data[0] & LAPB_SPF;
206 } else if ((skb->data[0] & LAPB_U) == 3) {
207
208
209
210 frame->type = skb->data[0] & ~LAPB_SPF;
211 frame->pf = skb->data[0] & LAPB_SPF;
212 }
213
214 frame->control[0] = skb->data[0];
215
216 skb_pull(skb, 1);
217 }
218
219 return 0;
220}
221
222
223
224
225
226
227
228void lapb_send_control(struct lapb_cb *lapb, int frametype,
229 int poll_bit, int type)
230{
231 struct sk_buff *skb;
232 unsigned char *dptr;
233
234 if ((skb = alloc_skb(LAPB_HEADER_LEN + 3, GFP_ATOMIC)) == NULL)
235 return;
236
237 skb_reserve(skb, LAPB_HEADER_LEN + 1);
238
239 if (lapb->mode & LAPB_EXTENDED) {
240 if ((frametype & LAPB_U) == LAPB_U) {
241 dptr = skb_put(skb, 1);
242 *dptr = frametype;
243 *dptr |= poll_bit ? LAPB_SPF : 0;
244 } else {
245 dptr = skb_put(skb, 2);
246 dptr[0] = frametype;
247 dptr[1] = (lapb->vr << 1);
248 dptr[1] |= poll_bit ? LAPB_EPF : 0;
249 }
250 } else {
251 dptr = skb_put(skb, 1);
252 *dptr = frametype;
253 *dptr |= poll_bit ? LAPB_SPF : 0;
254 if ((frametype & LAPB_U) == LAPB_S)
255 *dptr |= (lapb->vr << 5);
256 }
257
258 lapb_transmit_buffer(lapb, skb, type);
259}
260
261
262
263
264
265void lapb_transmit_frmr(struct lapb_cb *lapb)
266{
267 struct sk_buff *skb;
268 unsigned char *dptr;
269
270 if ((skb = alloc_skb(LAPB_HEADER_LEN + 7, GFP_ATOMIC)) == NULL)
271 return;
272
273 skb_reserve(skb, LAPB_HEADER_LEN + 1);
274
275 if (lapb->mode & LAPB_EXTENDED) {
276 dptr = skb_put(skb, 6);
277 *dptr++ = LAPB_FRMR;
278 *dptr++ = lapb->frmr_data.control[0];
279 *dptr++ = lapb->frmr_data.control[1];
280 *dptr++ = (lapb->vs << 1) & 0xFE;
281 *dptr = (lapb->vr << 1) & 0xFE;
282 if (lapb->frmr_data.cr == LAPB_RESPONSE)
283 *dptr |= 0x01;
284 dptr++;
285 *dptr++ = lapb->frmr_type;
286
287 lapb_dbg(1, "(%p) S%d TX FRMR %02X %02X %02X %02X %02X\n",
288 lapb->dev, lapb->state,
289 skb->data[1], skb->data[2], skb->data[3],
290 skb->data[4], skb->data[5]);
291 } else {
292 dptr = skb_put(skb, 4);
293 *dptr++ = LAPB_FRMR;
294 *dptr++ = lapb->frmr_data.control[0];
295 *dptr = (lapb->vs << 1) & 0x0E;
296 *dptr |= (lapb->vr << 5) & 0xE0;
297 if (lapb->frmr_data.cr == LAPB_RESPONSE)
298 *dptr |= 0x10;
299 dptr++;
300 *dptr++ = lapb->frmr_type;
301
302 lapb_dbg(1, "(%p) S%d TX FRMR %02X %02X %02X\n",
303 lapb->dev, lapb->state, skb->data[1],
304 skb->data[2], skb->data[3]);
305 }
306
307 lapb_transmit_buffer(lapb, skb, LAPB_RESPONSE);
308}
309