aboutsummaryrefslogtreecommitdiffstats
path: root/net/caif/cfpkt_skbuff.c
diff options
context:
space:
mode:
authorSjur Braendeland <sjur.brandeland@stericsson.com>2010-03-30 09:56:24 -0400
committerDavid S. Miller <davem@davemloft.net>2010-03-30 22:08:47 -0400
commit15c9ac0c80e390df09ce5730a7b08b13e07a8dd5 (patch)
treea8dc92bdf8564839e6837d003ddc76cf2d1ee7d8 /net/caif/cfpkt_skbuff.c
parentb482cd2053e3b90a7b33a78c63cdb6badf2ec383 (diff)
net-caif: add CAIF generic caif support functions
Support functions for the caif protocol stack: cfcnfg.c - CAIF Configuration Module used for adding and removing drivers and connection cfpkt_skbuff.c - CAIF Packet layer (SKB helper functions) Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/caif/cfpkt_skbuff.c')
-rw-r--r--net/caif/cfpkt_skbuff.c571
1 files changed, 571 insertions, 0 deletions
diff --git a/net/caif/cfpkt_skbuff.c b/net/caif/cfpkt_skbuff.c
new file mode 100644
index 000000000000..83fff2ff6658
--- /dev/null
+++ b/net/caif/cfpkt_skbuff.c
@@ -0,0 +1,571 @@
1/*
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
12#define PKT_PREFIX CAIF_NEEDED_HEADROOM
13#define PKT_POSTFIX CAIF_NEEDED_TAILROOM
14#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;
241 if (unlikely(is_erronous(pkt)))
242 return -EPROTO;
243 if (unlikely(skb_headroom(skb) < len)) {
244 PKT_ERROR(pkt, "cfpkt_add_head: no headroom\n");
245 return -EPROTO;
246 }
247
248 /* Make sure data is writable */
249 if (unlikely(skb_cow_data(skb, 0, &lastskb) < 0)) {
250 PKT_ERROR(pkt, "cfpkt_add_head: cow failed\n");
251 return -EPROTO;
252 }
253
254 to = skb_push(skb, len);
255 memcpy(to, data, len);
256 return 0;
257}
258EXPORT_SYMBOL(cfpkt_add_head);
259
260inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len)
261{
262 return cfpkt_add_body(pkt, data, len);
263}
264EXPORT_SYMBOL(cfpkt_add_trail);
265
266inline u16 cfpkt_getlen(struct cfpkt *pkt)
267{
268 struct sk_buff *skb = pkt_to_skb(pkt);
269 return skb->len;
270}
271EXPORT_SYMBOL(cfpkt_getlen);
272
273inline u16 cfpkt_iterate(struct cfpkt *pkt,
274 u16 (*iter_func)(u16, void *, u16),
275 u16 data)
276{
277 /*
278 * Don't care about the performance hit of linearizing,
279 * Checksum should not be used on high-speed interfaces anyway.
280 */
281 if (unlikely(is_erronous(pkt)))
282 return -EPROTO;
283 if (unlikely(skb_linearize(&pkt->skb) != 0)) {
284 PKT_ERROR(pkt, "cfpkt_iterate: linearize failed\n");
285 return -EPROTO;
286 }
287 return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt));
288}
289EXPORT_SYMBOL(cfpkt_iterate);
290
291int cfpkt_setlen(struct cfpkt *pkt, u16 len)
292{
293 struct sk_buff *skb = pkt_to_skb(pkt);
294
295
296 if (unlikely(is_erronous(pkt)))
297 return -EPROTO;
298
299 if (likely(len <= skb->len)) {
300 if (unlikely(skb->data_len))
301 ___pskb_trim(skb, len);
302 else
303 skb_trim(skb, len);
304
305 return cfpkt_getlen(pkt);
306 }
307
308 /* Need to expand SKB */
309 if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len)))
310 PKT_ERROR(pkt, "cfpkt_setlen: skb_pad_trail failed\n");
311
312 return cfpkt_getlen(pkt);
313}
314EXPORT_SYMBOL(cfpkt_setlen);
315
316struct cfpkt *cfpkt_create_uplink(const unsigned char *data, unsigned int len)
317{
318 struct cfpkt *pkt = cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
319 if (unlikely(data != NULL))
320 cfpkt_add_body(pkt, data, len);
321 return pkt;
322}
323EXPORT_SYMBOL(cfpkt_create_uplink);
324
325struct cfpkt *cfpkt_append(struct cfpkt *dstpkt,
326 struct cfpkt *addpkt,
327 u16 expectlen)
328{
329 struct sk_buff *dst = pkt_to_skb(dstpkt);
330 struct sk_buff *add = pkt_to_skb(addpkt);
331 u16 addlen = skb_headlen(add);
332 u16 neededtailspace;
333 struct sk_buff *tmp;
334 u16 dstlen;
335 u16 createlen;
336 if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) {
337 cfpkt_destroy(addpkt);
338 return dstpkt;
339 }
340 if (expectlen > addlen)
341 neededtailspace = expectlen;
342 else
343 neededtailspace = addlen;
344
345 if (dst->tail + neededtailspace > dst->end) {
346 /* Create a dumplicate of 'dst' with more tail space */
347 dstlen = skb_headlen(dst);
348 createlen = dstlen + neededtailspace;
349 tmp = pkt_to_skb(
350 cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX));
351 if (!tmp)
352 return NULL;
353 skb_set_tail_pointer(tmp, dstlen);
354 tmp->len = dstlen;
355 memcpy(tmp->data, dst->data, dstlen);
356 cfpkt_destroy(dstpkt);
357 dst = tmp;
358 }
359 memcpy(skb_tail_pointer(dst), add->data, skb_headlen(add));
360 cfpkt_destroy(addpkt);
361 dst->tail += addlen;
362 dst->len += addlen;
363 return skb_to_pkt(dst);
364}
365EXPORT_SYMBOL(cfpkt_append);
366
367struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos)
368{
369 struct sk_buff *skb2;
370 struct sk_buff *skb = pkt_to_skb(pkt);
371 u8 *split = skb->data + pos;
372 u16 len2nd = skb_tail_pointer(skb) - split;
373
374 if (unlikely(is_erronous(pkt)))
375 return NULL;
376
377 if (skb->data + pos > skb_tail_pointer(skb)) {
378 PKT_ERROR(pkt,
379 "cfpkt_split: trying to split beyond end of packet");
380 return NULL;
381 }
382
383 /* Create a new packet for the second part of the data */
384 skb2 = pkt_to_skb(
385 cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX,
386 PKT_PREFIX));
387
388 if (skb2 == NULL)
389 return NULL;
390
391 /* Reduce the length of the original packet */
392 skb_set_tail_pointer(skb, pos);
393 skb->len = pos;
394
395 memcpy(skb2->data, split, len2nd);
396 skb2->tail += len2nd;
397 skb2->len += len2nd;
398 return skb_to_pkt(skb2);
399}
400EXPORT_SYMBOL(cfpkt_split);
401
402char *cfpkt_log_pkt(struct cfpkt *pkt, char *buf, int buflen)
403{
404 struct sk_buff *skb = pkt_to_skb(pkt);
405 char *p = buf;
406 int i;
407
408 /*
409 * Sanity check buffer length, it needs to be at least as large as
410 * the header info: ~=50+ bytes
411 */
412 if (buflen < 50)
413 return NULL;
414
415 snprintf(buf, buflen, "%s: pkt:%p len:%ld(%ld+%ld) {%ld,%ld} data: [",
416 is_erronous(pkt) ? "ERRONOUS-SKB" :
417 (skb->data_len != 0 ? "COMPLEX-SKB" : "SKB"),
418 skb,
419 (long) skb->len,
420 (long) (skb_tail_pointer(skb) - skb->data),
421 (long) skb->data_len,
422 (long) (skb->data - skb->head),
423 (long) (skb_tail_pointer(skb) - skb->head));
424 p = buf + strlen(buf);
425
426 for (i = 0; i < skb_tail_pointer(skb) - skb->data && i < 300; i++) {
427 if (p > buf + buflen - 10) {
428 sprintf(p, "...");
429 p = buf + strlen(buf);
430 break;
431 }
432 sprintf(p, "%02x,", skb->data[i]);
433 p = buf + strlen(buf);
434 }
435 sprintf(p, "]\n");
436 return buf;
437}
438EXPORT_SYMBOL(cfpkt_log_pkt);
439
440int cfpkt_raw_append(struct cfpkt *pkt, void **buf, unsigned int buflen)
441{
442 struct sk_buff *skb = pkt_to_skb(pkt);
443 struct sk_buff *lastskb;
444
445 caif_assert(buf != NULL);
446 if (unlikely(is_erronous(pkt)))
447 return -EPROTO;
448 /* Make sure SKB is writable */
449 if (unlikely(skb_cow_data(skb, 0, &lastskb) < 0)) {
450 PKT_ERROR(pkt, "cfpkt_raw_append: skb_cow_data failed\n");
451 return -EPROTO;
452 }
453
454 if (unlikely(skb_linearize(skb) != 0)) {
455 PKT_ERROR(pkt, "cfpkt_raw_append: linearize failed\n");
456 return -EPROTO;
457 }
458
459 if (unlikely(skb_tailroom(skb) < buflen)) {
460 PKT_ERROR(pkt, "cfpkt_raw_append: buffer too short - failed\n");
461 return -EPROTO;
462 }
463
464 *buf = skb_put(skb, buflen);
465 return 1;
466}
467EXPORT_SYMBOL(cfpkt_raw_append);
468
469int cfpkt_raw_extract(struct cfpkt *pkt, void **buf, unsigned int buflen)
470{
471 struct sk_buff *skb = pkt_to_skb(pkt);
472
473 caif_assert(buf != NULL);
474 if (unlikely(is_erronous(pkt)))
475 return -EPROTO;
476
477 if (unlikely(buflen > skb->len)) {
478 PKT_ERROR(pkt, "cfpkt_raw_extract: buflen too large "
479 "- failed\n");
480 return -EPROTO;
481 }
482
483 if (unlikely(buflen > skb_headlen(skb))) {
484 if (unlikely(skb_linearize(skb) != 0)) {
485 PKT_ERROR(pkt, "cfpkt_raw_extract: linearize failed\n");
486 return -EPROTO;
487 }
488 }
489
490 *buf = skb->data;
491 skb_pull(skb, buflen);
492
493 return 1;
494}
495EXPORT_SYMBOL(cfpkt_raw_extract);
496
497inline bool cfpkt_erroneous(struct cfpkt *pkt)
498{
499 return cfpkt_priv(pkt)->erronous;
500}
501EXPORT_SYMBOL(cfpkt_erroneous);
502
503struct cfpktq *cfpktq_create(void)
504{
505 struct cfpktq *q = kmalloc(sizeof(struct cfpktq), GFP_ATOMIC);
506 if (!q)
507 return NULL;
508 skb_queue_head_init(&q->head);
509 atomic_set(&q->count, 0);
510 spin_lock_init(&q->lock);
511 return q;
512}
513EXPORT_SYMBOL(cfpktq_create);
514
515void cfpkt_queue(struct cfpktq *pktq, struct cfpkt *pkt, unsigned short prio)
516{
517 atomic_inc(&pktq->count);
518 spin_lock(&pktq->lock);
519 skb_queue_tail(&pktq->head, pkt_to_skb(pkt));
520 spin_unlock(&pktq->lock);
521
522}
523EXPORT_SYMBOL(cfpkt_queue);
524
525struct cfpkt *cfpkt_qpeek(struct cfpktq *pktq)
526{
527 struct cfpkt *tmp;
528 spin_lock(&pktq->lock);
529 tmp = skb_to_pkt(skb_peek(&pktq->head));
530 spin_unlock(&pktq->lock);
531 return tmp;
532}
533EXPORT_SYMBOL(cfpkt_qpeek);
534
535struct cfpkt *cfpkt_dequeue(struct cfpktq *pktq)
536{
537 struct cfpkt *pkt;
538 spin_lock(&pktq->lock);
539 pkt = skb_to_pkt(skb_dequeue(&pktq->head));
540 if (pkt) {
541 atomic_dec(&pktq->count);
542 caif_assert(atomic_read(&pktq->count) >= 0);
543 }
544 spin_unlock(&pktq->lock);
545 return pkt;
546}
547EXPORT_SYMBOL(cfpkt_dequeue);
548
549int cfpkt_qcount(struct cfpktq *pktq)
550{
551 return atomic_read(&pktq->count);
552}
553EXPORT_SYMBOL(cfpkt_qcount);
554
555struct cfpkt *cfpkt_clone_release(struct cfpkt *pkt)
556{
557 struct cfpkt *clone;
558 clone = skb_to_pkt(skb_clone(pkt_to_skb(pkt), GFP_ATOMIC));
559 /* Free original packet. */
560 cfpkt_destroy(pkt);
561 if (!clone)
562 return NULL;
563 return clone;
564}
565EXPORT_SYMBOL(cfpkt_clone_release);
566
567struct caif_payload_info *cfpkt_info(struct cfpkt *pkt)
568{
569 return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb;
570}
571EXPORT_SYMBOL(cfpkt_info);