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Sjur Braendeland15c9ac02010-03-30 13:56:24 +00001/*
2 * Copyright (C) ST-Ericsson AB 2010
3 * Author: Sjur Brendeland/sjur.brandeland@stericsson.com
4 * License terms: GNU General Public License (GPL) version 2
5 */
6
7#include <linux/string.h>
8#include <linux/skbuff.h>
9#include <linux/hardirq.h>
10#include <net/caif/cfpkt.h>
11
Sjur Braendeland24e263a2010-08-10 07:36:46 +000012#define PKT_PREFIX 48
Sjur Braendeland2aa40ae2010-06-17 06:55:40 +000013#define PKT_POSTFIX 2
Sjur Braendeland15c9ac02010-03-30 13:56:24 +000014#define PKT_LEN_WHEN_EXTENDING 128
15#define PKT_ERROR(pkt, errmsg) do { \
16 cfpkt_priv(pkt)->erronous = true; \
17 skb_reset_tail_pointer(&pkt->skb); \
18 pr_warning("CAIF: " errmsg);\
19 } while (0)
20
21struct cfpktq {
22 struct sk_buff_head head;
23 atomic_t count;
24 /* Lock protects count updates */
25 spinlock_t lock;
26};
27
28/*
29 * net/caif/ is generic and does not
30 * understand SKB, so we do this typecast
31 */
32struct cfpkt {
33 struct sk_buff skb;
34};
35
36/* Private data inside SKB */
37struct cfpkt_priv_data {
38 struct dev_info dev_info;
39 bool erronous;
40};
41
42inline struct cfpkt_priv_data *cfpkt_priv(struct cfpkt *pkt)
43{
44 return (struct cfpkt_priv_data *) pkt->skb.cb;
45}
46
47inline bool is_erronous(struct cfpkt *pkt)
48{
49 return cfpkt_priv(pkt)->erronous;
50}
51
52inline struct sk_buff *pkt_to_skb(struct cfpkt *pkt)
53{
54 return &pkt->skb;
55}
56
57inline struct cfpkt *skb_to_pkt(struct sk_buff *skb)
58{
59 return (struct cfpkt *) skb;
60}
61
62
63struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt)
64{
65 struct cfpkt *pkt = skb_to_pkt(nativepkt);
66 cfpkt_priv(pkt)->erronous = false;
67 return pkt;
68}
69EXPORT_SYMBOL(cfpkt_fromnative);
70
71void *cfpkt_tonative(struct cfpkt *pkt)
72{
73 return (void *) pkt;
74}
75EXPORT_SYMBOL(cfpkt_tonative);
76
77static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx)
78{
79 struct sk_buff *skb;
80
81 if (likely(in_interrupt()))
82 skb = alloc_skb(len + pfx, GFP_ATOMIC);
83 else
84 skb = alloc_skb(len + pfx, GFP_KERNEL);
85
86 if (unlikely(skb == NULL))
87 return NULL;
88
89 skb_reserve(skb, pfx);
90 return skb_to_pkt(skb);
91}
92
93inline struct cfpkt *cfpkt_create(u16 len)
94{
95 return cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
96}
97EXPORT_SYMBOL(cfpkt_create);
98
99void cfpkt_destroy(struct cfpkt *pkt)
100{
101 struct sk_buff *skb = pkt_to_skb(pkt);
102 kfree_skb(skb);
103}
104EXPORT_SYMBOL(cfpkt_destroy);
105
106inline bool cfpkt_more(struct cfpkt *pkt)
107{
108 struct sk_buff *skb = pkt_to_skb(pkt);
109 return skb->len > 0;
110}
111EXPORT_SYMBOL(cfpkt_more);
112
113int cfpkt_peek_head(struct cfpkt *pkt, void *data, u16 len)
114{
115 struct sk_buff *skb = pkt_to_skb(pkt);
116 if (skb_headlen(skb) >= len) {
117 memcpy(data, skb->data, len);
118 return 0;
119 }
120 return !cfpkt_extr_head(pkt, data, len) &&
121 !cfpkt_add_head(pkt, data, len);
122}
123EXPORT_SYMBOL(cfpkt_peek_head);
124
125int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len)
126{
127 struct sk_buff *skb = pkt_to_skb(pkt);
128 u8 *from;
129 if (unlikely(is_erronous(pkt)))
130 return -EPROTO;
131
132 if (unlikely(len > skb->len)) {
133 PKT_ERROR(pkt, "cfpkt_extr_head read beyond end of packet\n");
134 return -EPROTO;
135 }
136
137 if (unlikely(len > skb_headlen(skb))) {
138 if (unlikely(skb_linearize(skb) != 0)) {
139 PKT_ERROR(pkt, "cfpkt_extr_head linearize failed\n");
140 return -EPROTO;
141 }
142 }
143 from = skb_pull(skb, len);
144 from -= len;
145 memcpy(data, from, len);
146 return 0;
147}
148EXPORT_SYMBOL(cfpkt_extr_head);
149
150int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len)
151{
152 struct sk_buff *skb = pkt_to_skb(pkt);
153 u8 *data = dta;
154 u8 *from;
155 if (unlikely(is_erronous(pkt)))
156 return -EPROTO;
157
158 if (unlikely(skb_linearize(skb) != 0)) {
159 PKT_ERROR(pkt, "cfpkt_extr_trail linearize failed\n");
160 return -EPROTO;
161 }
162 if (unlikely(skb->data + len > skb_tail_pointer(skb))) {
163 PKT_ERROR(pkt, "cfpkt_extr_trail read beyond end of packet\n");
164 return -EPROTO;
165 }
166 from = skb_tail_pointer(skb) - len;
167 skb_trim(skb, skb->len - len);
168 memcpy(data, from, len);
169 return 0;
170}
171EXPORT_SYMBOL(cfpkt_extr_trail);
172
173int cfpkt_pad_trail(struct cfpkt *pkt, u16 len)
174{
175 return cfpkt_add_body(pkt, NULL, len);
176}
177EXPORT_SYMBOL(cfpkt_pad_trail);
178
179int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len)
180{
181 struct sk_buff *skb = pkt_to_skb(pkt);
182 struct sk_buff *lastskb;
183 u8 *to;
184 u16 addlen = 0;
185
186
187 if (unlikely(is_erronous(pkt)))
188 return -EPROTO;
189
190 lastskb = skb;
191
192 /* Check whether we need to add space at the tail */
193 if (unlikely(skb_tailroom(skb) < len)) {
194 if (likely(len < PKT_LEN_WHEN_EXTENDING))
195 addlen = PKT_LEN_WHEN_EXTENDING;
196 else
197 addlen = len;
198 }
199
200 /* Check whether we need to change the SKB before writing to the tail */
201 if (unlikely((addlen > 0) || skb_cloned(skb) || skb_shared(skb))) {
202
203 /* Make sure data is writable */
204 if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) {
205 PKT_ERROR(pkt, "cfpkt_add_body: cow failed\n");
206 return -EPROTO;
207 }
208 /*
209 * Is the SKB non-linear after skb_cow_data()? If so, we are
210 * going to add data to the last SKB, so we need to adjust
211 * lengths of the top SKB.
212 */
213 if (lastskb != skb) {
214 pr_warning("CAIF: %s(): Packet is non-linear\n",
215 __func__);
216 skb->len += len;
217 skb->data_len += len;
218 }
219 }
220
221 /* All set to put the last SKB and optionally write data there. */
222 to = skb_put(lastskb, len);
223 if (likely(data))
224 memcpy(to, data, len);
225 return 0;
226}
227EXPORT_SYMBOL(cfpkt_add_body);
228
229inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data)
230{
231 return cfpkt_add_body(pkt, &data, 1);
232}
233EXPORT_SYMBOL(cfpkt_addbdy);
234
235int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len)
236{
237 struct sk_buff *skb = pkt_to_skb(pkt);
238 struct sk_buff *lastskb;
239 u8 *to;
240 const u8 *data = data2;
Sjur Braendeland638e6282010-05-21 02:16:09 +0000241 int ret;
Sjur Braendeland15c9ac02010-03-30 13:56:24 +0000242 if (unlikely(is_erronous(pkt)))
243 return -EPROTO;
244 if (unlikely(skb_headroom(skb) < len)) {
245 PKT_ERROR(pkt, "cfpkt_add_head: no headroom\n");
246 return -EPROTO;
247 }
248
249 /* Make sure data is writable */
Sjur Braendeland638e6282010-05-21 02:16:09 +0000250 ret = skb_cow_data(skb, 0, &lastskb);
251 if (unlikely(ret < 0)) {
Sjur Braendeland15c9ac02010-03-30 13:56:24 +0000252 PKT_ERROR(pkt, "cfpkt_add_head: cow failed\n");
Sjur Braendeland638e6282010-05-21 02:16:09 +0000253 return ret;
Sjur Braendeland15c9ac02010-03-30 13:56:24 +0000254 }
255
256 to = skb_push(skb, len);
257 memcpy(to, data, len);
258 return 0;
259}
260EXPORT_SYMBOL(cfpkt_add_head);
261
262inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len)
263{
264 return cfpkt_add_body(pkt, data, len);
265}
266EXPORT_SYMBOL(cfpkt_add_trail);
267
268inline u16 cfpkt_getlen(struct cfpkt *pkt)
269{
270 struct sk_buff *skb = pkt_to_skb(pkt);
271 return skb->len;
272}
273EXPORT_SYMBOL(cfpkt_getlen);
274
275inline u16 cfpkt_iterate(struct cfpkt *pkt,
276 u16 (*iter_func)(u16, void *, u16),
277 u16 data)
278{
279 /*
280 * Don't care about the performance hit of linearizing,
281 * Checksum should not be used on high-speed interfaces anyway.
282 */
283 if (unlikely(is_erronous(pkt)))
284 return -EPROTO;
285 if (unlikely(skb_linearize(&pkt->skb) != 0)) {
286 PKT_ERROR(pkt, "cfpkt_iterate: linearize failed\n");
287 return -EPROTO;
288 }
289 return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt));
290}
291EXPORT_SYMBOL(cfpkt_iterate);
292
293int cfpkt_setlen(struct cfpkt *pkt, u16 len)
294{
295 struct sk_buff *skb = pkt_to_skb(pkt);
296
297
298 if (unlikely(is_erronous(pkt)))
299 return -EPROTO;
300
301 if (likely(len <= skb->len)) {
302 if (unlikely(skb->data_len))
303 ___pskb_trim(skb, len);
304 else
305 skb_trim(skb, len);
306
307 return cfpkt_getlen(pkt);
308 }
309
310 /* Need to expand SKB */
311 if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len)))
312 PKT_ERROR(pkt, "cfpkt_setlen: skb_pad_trail failed\n");
313
314 return cfpkt_getlen(pkt);
315}
316EXPORT_SYMBOL(cfpkt_setlen);
317
318struct cfpkt *cfpkt_create_uplink(const unsigned char *data, unsigned int len)
319{
320 struct cfpkt *pkt = cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
Sjur Braendeland638e6282010-05-21 02:16:09 +0000321 if (!pkt)
322 return NULL;
Sjur Braendeland15c9ac02010-03-30 13:56:24 +0000323 if (unlikely(data != NULL))
324 cfpkt_add_body(pkt, data, len);
325 return pkt;
326}
327EXPORT_SYMBOL(cfpkt_create_uplink);
328
329struct cfpkt *cfpkt_append(struct cfpkt *dstpkt,
330 struct cfpkt *addpkt,
331 u16 expectlen)
332{
333 struct sk_buff *dst = pkt_to_skb(dstpkt);
334 struct sk_buff *add = pkt_to_skb(addpkt);
335 u16 addlen = skb_headlen(add);
336 u16 neededtailspace;
337 struct sk_buff *tmp;
338 u16 dstlen;
339 u16 createlen;
340 if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) {
Sjur Braendeland15c9ac02010-03-30 13:56:24 +0000341 return dstpkt;
342 }
343 if (expectlen > addlen)
344 neededtailspace = expectlen;
345 else
346 neededtailspace = addlen;
347
348 if (dst->tail + neededtailspace > dst->end) {
349 /* Create a dumplicate of 'dst' with more tail space */
Sjur Braendeland638e6282010-05-21 02:16:09 +0000350 struct cfpkt *tmppkt;
Sjur Braendeland15c9ac02010-03-30 13:56:24 +0000351 dstlen = skb_headlen(dst);
352 createlen = dstlen + neededtailspace;
Sjur Braendeland638e6282010-05-21 02:16:09 +0000353 tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX);
354 if (tmppkt == NULL)
Sjur Braendeland15c9ac02010-03-30 13:56:24 +0000355 return NULL;
Sjur Braendeland638e6282010-05-21 02:16:09 +0000356 tmp = pkt_to_skb(tmppkt);
Sjur Braendeland15c9ac02010-03-30 13:56:24 +0000357 skb_set_tail_pointer(tmp, dstlen);
358 tmp->len = dstlen;
359 memcpy(tmp->data, dst->data, dstlen);
360 cfpkt_destroy(dstpkt);
361 dst = tmp;
362 }
363 memcpy(skb_tail_pointer(dst), add->data, skb_headlen(add));
364 cfpkt_destroy(addpkt);
365 dst->tail += addlen;
366 dst->len += addlen;
367 return skb_to_pkt(dst);
368}
369EXPORT_SYMBOL(cfpkt_append);
370
371struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos)
372{
373 struct sk_buff *skb2;
374 struct sk_buff *skb = pkt_to_skb(pkt);
Sjur Braendeland638e6282010-05-21 02:16:09 +0000375 struct cfpkt *tmppkt;
Sjur Braendeland15c9ac02010-03-30 13:56:24 +0000376 u8 *split = skb->data + pos;
377 u16 len2nd = skb_tail_pointer(skb) - split;
378
379 if (unlikely(is_erronous(pkt)))
380 return NULL;
381
382 if (skb->data + pos > skb_tail_pointer(skb)) {
383 PKT_ERROR(pkt,
384 "cfpkt_split: trying to split beyond end of packet");
385 return NULL;
386 }
387
388 /* Create a new packet for the second part of the data */
Sjur Braendeland638e6282010-05-21 02:16:09 +0000389 tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX,
390 PKT_PREFIX);
391 if (tmppkt == NULL)
392 return NULL;
393 skb2 = pkt_to_skb(tmppkt);
394
Sjur Braendeland15c9ac02010-03-30 13:56:24 +0000395
396 if (skb2 == NULL)
397 return NULL;
398
399 /* Reduce the length of the original packet */
400 skb_set_tail_pointer(skb, pos);
401 skb->len = pos;
402
403 memcpy(skb2->data, split, len2nd);
404 skb2->tail += len2nd;
405 skb2->len += len2nd;
406 return skb_to_pkt(skb2);
407}
408EXPORT_SYMBOL(cfpkt_split);
409
410char *cfpkt_log_pkt(struct cfpkt *pkt, char *buf, int buflen)
411{
412 struct sk_buff *skb = pkt_to_skb(pkt);
413 char *p = buf;
414 int i;
415
416 /*
417 * Sanity check buffer length, it needs to be at least as large as
418 * the header info: ~=50+ bytes
419 */
420 if (buflen < 50)
421 return NULL;
422
423 snprintf(buf, buflen, "%s: pkt:%p len:%ld(%ld+%ld) {%ld,%ld} data: [",
424 is_erronous(pkt) ? "ERRONOUS-SKB" :
425 (skb->data_len != 0 ? "COMPLEX-SKB" : "SKB"),
426 skb,
427 (long) skb->len,
428 (long) (skb_tail_pointer(skb) - skb->data),
429 (long) skb->data_len,
430 (long) (skb->data - skb->head),
431 (long) (skb_tail_pointer(skb) - skb->head));
432 p = buf + strlen(buf);
433
434 for (i = 0; i < skb_tail_pointer(skb) - skb->data && i < 300; i++) {
435 if (p > buf + buflen - 10) {
436 sprintf(p, "...");
437 p = buf + strlen(buf);
438 break;
439 }
440 sprintf(p, "%02x,", skb->data[i]);
441 p = buf + strlen(buf);
442 }
443 sprintf(p, "]\n");
444 return buf;
445}
446EXPORT_SYMBOL(cfpkt_log_pkt);
447
448int cfpkt_raw_append(struct cfpkt *pkt, void **buf, unsigned int buflen)
449{
450 struct sk_buff *skb = pkt_to_skb(pkt);
451 struct sk_buff *lastskb;
452
453 caif_assert(buf != NULL);
454 if (unlikely(is_erronous(pkt)))
455 return -EPROTO;
456 /* Make sure SKB is writable */
457 if (unlikely(skb_cow_data(skb, 0, &lastskb) < 0)) {
458 PKT_ERROR(pkt, "cfpkt_raw_append: skb_cow_data failed\n");
459 return -EPROTO;
460 }
461
462 if (unlikely(skb_linearize(skb) != 0)) {
463 PKT_ERROR(pkt, "cfpkt_raw_append: linearize failed\n");
464 return -EPROTO;
465 }
466
467 if (unlikely(skb_tailroom(skb) < buflen)) {
468 PKT_ERROR(pkt, "cfpkt_raw_append: buffer too short - failed\n");
469 return -EPROTO;
470 }
471
472 *buf = skb_put(skb, buflen);
473 return 1;
474}
475EXPORT_SYMBOL(cfpkt_raw_append);
476
477int cfpkt_raw_extract(struct cfpkt *pkt, void **buf, unsigned int buflen)
478{
479 struct sk_buff *skb = pkt_to_skb(pkt);
480
481 caif_assert(buf != NULL);
482 if (unlikely(is_erronous(pkt)))
483 return -EPROTO;
484
485 if (unlikely(buflen > skb->len)) {
486 PKT_ERROR(pkt, "cfpkt_raw_extract: buflen too large "
487 "- failed\n");
488 return -EPROTO;
489 }
490
491 if (unlikely(buflen > skb_headlen(skb))) {
492 if (unlikely(skb_linearize(skb) != 0)) {
493 PKT_ERROR(pkt, "cfpkt_raw_extract: linearize failed\n");
494 return -EPROTO;
495 }
496 }
497
498 *buf = skb->data;
499 skb_pull(skb, buflen);
500
501 return 1;
502}
503EXPORT_SYMBOL(cfpkt_raw_extract);
504
505inline bool cfpkt_erroneous(struct cfpkt *pkt)
506{
507 return cfpkt_priv(pkt)->erronous;
508}
509EXPORT_SYMBOL(cfpkt_erroneous);
510
511struct cfpktq *cfpktq_create(void)
512{
513 struct cfpktq *q = kmalloc(sizeof(struct cfpktq), GFP_ATOMIC);
514 if (!q)
515 return NULL;
516 skb_queue_head_init(&q->head);
517 atomic_set(&q->count, 0);
518 spin_lock_init(&q->lock);
519 return q;
520}
521EXPORT_SYMBOL(cfpktq_create);
522
523void cfpkt_queue(struct cfpktq *pktq, struct cfpkt *pkt, unsigned short prio)
524{
525 atomic_inc(&pktq->count);
526 spin_lock(&pktq->lock);
527 skb_queue_tail(&pktq->head, pkt_to_skb(pkt));
528 spin_unlock(&pktq->lock);
529
530}
531EXPORT_SYMBOL(cfpkt_queue);
532
533struct cfpkt *cfpkt_qpeek(struct cfpktq *pktq)
534{
535 struct cfpkt *tmp;
536 spin_lock(&pktq->lock);
537 tmp = skb_to_pkt(skb_peek(&pktq->head));
538 spin_unlock(&pktq->lock);
539 return tmp;
540}
541EXPORT_SYMBOL(cfpkt_qpeek);
542
543struct cfpkt *cfpkt_dequeue(struct cfpktq *pktq)
544{
545 struct cfpkt *pkt;
546 spin_lock(&pktq->lock);
547 pkt = skb_to_pkt(skb_dequeue(&pktq->head));
548 if (pkt) {
549 atomic_dec(&pktq->count);
550 caif_assert(atomic_read(&pktq->count) >= 0);
551 }
552 spin_unlock(&pktq->lock);
553 return pkt;
554}
555EXPORT_SYMBOL(cfpkt_dequeue);
556
557int cfpkt_qcount(struct cfpktq *pktq)
558{
559 return atomic_read(&pktq->count);
560}
561EXPORT_SYMBOL(cfpkt_qcount);
562
563struct cfpkt *cfpkt_clone_release(struct cfpkt *pkt)
564{
565 struct cfpkt *clone;
566 clone = skb_to_pkt(skb_clone(pkt_to_skb(pkt), GFP_ATOMIC));
567 /* Free original packet. */
568 cfpkt_destroy(pkt);
569 if (!clone)
570 return NULL;
571 return clone;
572}
573EXPORT_SYMBOL(cfpkt_clone_release);
574
575struct caif_payload_info *cfpkt_info(struct cfpkt *pkt)
576{
577 return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb;
578}
579EXPORT_SYMBOL(cfpkt_info);