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
7 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
9 #include <linux/string.h>
10 #include <linux/skbuff.h>
11 #include <linux/hardirq.h>
12 #include <net/caif/cfpkt.h>
16 #define PKT_LEN_WHEN_EXTENDING 128
17 #define PKT_ERROR(pkt, errmsg) \
19 cfpkt_priv(pkt)->erronous = true; \
20 skb_reset_tail_pointer(&pkt->skb); \
25 struct sk_buff_head head;
27 /* Lock protects count updates */
32 * net/caif/ is generic and does not
33 * understand SKB, so we do this typecast
39 /* Private data inside SKB */
40 struct cfpkt_priv_data {
41 struct dev_info dev_info;
45 static inline struct cfpkt_priv_data *cfpkt_priv(struct cfpkt *pkt)
47 return (struct cfpkt_priv_data *) pkt->skb.cb;
50 static inline bool is_erronous(struct cfpkt *pkt)
52 return cfpkt_priv(pkt)->erronous;
55 static inline struct sk_buff *pkt_to_skb(struct cfpkt *pkt)
60 static inline struct cfpkt *skb_to_pkt(struct sk_buff *skb)
62 return (struct cfpkt *) skb;
66 struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt)
68 struct cfpkt *pkt = skb_to_pkt(nativepkt);
69 cfpkt_priv(pkt)->erronous = false;
72 EXPORT_SYMBOL(cfpkt_fromnative);
74 void *cfpkt_tonative(struct cfpkt *pkt)
78 EXPORT_SYMBOL(cfpkt_tonative);
80 static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx)
84 if (likely(in_interrupt()))
85 skb = alloc_skb(len + pfx, GFP_ATOMIC);
87 skb = alloc_skb(len + pfx, GFP_KERNEL);
89 if (unlikely(skb == NULL))
92 skb_reserve(skb, pfx);
93 return skb_to_pkt(skb);
96 inline struct cfpkt *cfpkt_create(u16 len)
98 return cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
100 EXPORT_SYMBOL(cfpkt_create);
102 void cfpkt_destroy(struct cfpkt *pkt)
104 struct sk_buff *skb = pkt_to_skb(pkt);
107 EXPORT_SYMBOL(cfpkt_destroy);
109 inline bool cfpkt_more(struct cfpkt *pkt)
111 struct sk_buff *skb = pkt_to_skb(pkt);
114 EXPORT_SYMBOL(cfpkt_more);
116 int cfpkt_peek_head(struct cfpkt *pkt, void *data, u16 len)
118 struct sk_buff *skb = pkt_to_skb(pkt);
119 if (skb_headlen(skb) >= len) {
120 memcpy(data, skb->data, len);
123 return !cfpkt_extr_head(pkt, data, len) &&
124 !cfpkt_add_head(pkt, data, len);
126 EXPORT_SYMBOL(cfpkt_peek_head);
128 int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len)
130 struct sk_buff *skb = pkt_to_skb(pkt);
132 if (unlikely(is_erronous(pkt)))
135 if (unlikely(len > skb->len)) {
136 PKT_ERROR(pkt, "read beyond end of packet\n");
140 if (unlikely(len > skb_headlen(skb))) {
141 if (unlikely(skb_linearize(skb) != 0)) {
142 PKT_ERROR(pkt, "linearize failed\n");
146 from = skb_pull(skb, len);
148 memcpy(data, from, len);
151 EXPORT_SYMBOL(cfpkt_extr_head);
153 int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len)
155 struct sk_buff *skb = pkt_to_skb(pkt);
158 if (unlikely(is_erronous(pkt)))
161 if (unlikely(skb_linearize(skb) != 0)) {
162 PKT_ERROR(pkt, "linearize failed\n");
165 if (unlikely(skb->data + len > skb_tail_pointer(skb))) {
166 PKT_ERROR(pkt, "read beyond end of packet\n");
169 from = skb_tail_pointer(skb) - len;
170 skb_trim(skb, skb->len - len);
171 memcpy(data, from, len);
174 EXPORT_SYMBOL(cfpkt_extr_trail);
176 int cfpkt_pad_trail(struct cfpkt *pkt, u16 len)
178 return cfpkt_add_body(pkt, NULL, len);
180 EXPORT_SYMBOL(cfpkt_pad_trail);
182 int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len)
184 struct sk_buff *skb = pkt_to_skb(pkt);
185 struct sk_buff *lastskb;
190 if (unlikely(is_erronous(pkt)))
195 /* Check whether we need to add space at the tail */
196 if (unlikely(skb_tailroom(skb) < len)) {
197 if (likely(len < PKT_LEN_WHEN_EXTENDING))
198 addlen = PKT_LEN_WHEN_EXTENDING;
203 /* Check whether we need to change the SKB before writing to the tail */
204 if (unlikely((addlen > 0) || skb_cloned(skb) || skb_shared(skb))) {
206 /* Make sure data is writable */
207 if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) {
208 PKT_ERROR(pkt, "cow failed\n");
212 * Is the SKB non-linear after skb_cow_data()? If so, we are
213 * going to add data to the last SKB, so we need to adjust
214 * lengths of the top SKB.
216 if (lastskb != skb) {
217 pr_warn("Packet is non-linear\n");
219 skb->data_len += len;
223 /* All set to put the last SKB and optionally write data there. */
224 to = skb_put(lastskb, len);
226 memcpy(to, data, len);
229 EXPORT_SYMBOL(cfpkt_add_body);
231 inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data)
233 return cfpkt_add_body(pkt, &data, 1);
235 EXPORT_SYMBOL(cfpkt_addbdy);
237 int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len)
239 struct sk_buff *skb = pkt_to_skb(pkt);
240 struct sk_buff *lastskb;
242 const u8 *data = data2;
244 if (unlikely(is_erronous(pkt)))
246 if (unlikely(skb_headroom(skb) < len)) {
247 PKT_ERROR(pkt, "no headroom\n");
251 /* Make sure data is writable */
252 ret = skb_cow_data(skb, 0, &lastskb);
253 if (unlikely(ret < 0)) {
254 PKT_ERROR(pkt, "cow failed\n");
258 to = skb_push(skb, len);
259 memcpy(to, data, len);
262 EXPORT_SYMBOL(cfpkt_add_head);
264 inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len)
266 return cfpkt_add_body(pkt, data, len);
268 EXPORT_SYMBOL(cfpkt_add_trail);
270 inline u16 cfpkt_getlen(struct cfpkt *pkt)
272 struct sk_buff *skb = pkt_to_skb(pkt);
275 EXPORT_SYMBOL(cfpkt_getlen);
277 inline u16 cfpkt_iterate(struct cfpkt *pkt,
278 u16 (*iter_func)(u16, void *, u16),
282 * Don't care about the performance hit of linearizing,
283 * Checksum should not be used on high-speed interfaces anyway.
285 if (unlikely(is_erronous(pkt)))
287 if (unlikely(skb_linearize(&pkt->skb) != 0)) {
288 PKT_ERROR(pkt, "linearize failed\n");
291 return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt));
293 EXPORT_SYMBOL(cfpkt_iterate);
295 int cfpkt_setlen(struct cfpkt *pkt, u16 len)
297 struct sk_buff *skb = pkt_to_skb(pkt);
300 if (unlikely(is_erronous(pkt)))
303 if (likely(len <= skb->len)) {
304 if (unlikely(skb->data_len))
305 ___pskb_trim(skb, len);
309 return cfpkt_getlen(pkt);
312 /* Need to expand SKB */
313 if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len)))
314 PKT_ERROR(pkt, "skb_pad_trail failed\n");
316 return cfpkt_getlen(pkt);
318 EXPORT_SYMBOL(cfpkt_setlen);
320 struct cfpkt *cfpkt_append(struct cfpkt *dstpkt,
321 struct cfpkt *addpkt,
324 struct sk_buff *dst = pkt_to_skb(dstpkt);
325 struct sk_buff *add = pkt_to_skb(addpkt);
326 u16 addlen = skb_headlen(add);
331 if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) {
334 if (expectlen > addlen)
335 neededtailspace = expectlen;
337 neededtailspace = addlen;
339 if (dst->tail + neededtailspace > dst->end) {
340 /* Create a dumplicate of 'dst' with more tail space */
341 struct cfpkt *tmppkt;
342 dstlen = skb_headlen(dst);
343 createlen = dstlen + neededtailspace;
344 tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX);
347 tmp = pkt_to_skb(tmppkt);
348 skb_set_tail_pointer(tmp, dstlen);
350 memcpy(tmp->data, dst->data, dstlen);
351 cfpkt_destroy(dstpkt);
354 memcpy(skb_tail_pointer(dst), add->data, skb_headlen(add));
355 cfpkt_destroy(addpkt);
358 return skb_to_pkt(dst);
360 EXPORT_SYMBOL(cfpkt_append);
362 struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos)
364 struct sk_buff *skb2;
365 struct sk_buff *skb = pkt_to_skb(pkt);
366 struct cfpkt *tmppkt;
367 u8 *split = skb->data + pos;
368 u16 len2nd = skb_tail_pointer(skb) - split;
370 if (unlikely(is_erronous(pkt)))
373 if (skb->data + pos > skb_tail_pointer(skb)) {
374 PKT_ERROR(pkt, "trying to split beyond end of packet\n");
378 /* Create a new packet for the second part of the data */
379 tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX,
383 skb2 = pkt_to_skb(tmppkt);
389 /* Reduce the length of the original packet */
390 skb_set_tail_pointer(skb, pos);
393 memcpy(skb2->data, split, len2nd);
394 skb2->tail += len2nd;
396 return skb_to_pkt(skb2);
398 EXPORT_SYMBOL(cfpkt_split);
400 bool cfpkt_erroneous(struct cfpkt *pkt)
402 return cfpkt_priv(pkt)->erronous;
404 EXPORT_SYMBOL(cfpkt_erroneous);
407 struct caif_payload_info *cfpkt_info(struct cfpkt *pkt)
409 return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb;
411 EXPORT_SYMBOL(cfpkt_info);