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 <linux/export.h>
13 #include <net/caif/cfpkt.h>
17 #define PKT_LEN_WHEN_EXTENDING 128
18 #define PKT_ERROR(pkt, errmsg) \
20 cfpkt_priv(pkt)->erronous = true; \
21 skb_reset_tail_pointer(&pkt->skb); \
26 struct sk_buff_head head;
28 /* Lock protects count updates */
33 * net/caif/ is generic and does not
34 * understand SKB, so we do this typecast
40 /* Private data inside SKB */
41 struct cfpkt_priv_data {
42 struct dev_info dev_info;
46 static inline struct cfpkt_priv_data *cfpkt_priv(struct cfpkt *pkt)
48 return (struct cfpkt_priv_data *) pkt->skb.cb;
51 static inline bool is_erronous(struct cfpkt *pkt)
53 return cfpkt_priv(pkt)->erronous;
56 static inline struct sk_buff *pkt_to_skb(struct cfpkt *pkt)
61 static inline struct cfpkt *skb_to_pkt(struct sk_buff *skb)
63 return (struct cfpkt *) skb;
67 struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt)
69 struct cfpkt *pkt = skb_to_pkt(nativepkt);
70 cfpkt_priv(pkt)->erronous = false;
73 EXPORT_SYMBOL(cfpkt_fromnative);
75 void *cfpkt_tonative(struct cfpkt *pkt)
79 EXPORT_SYMBOL(cfpkt_tonative);
81 static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx)
85 if (likely(in_interrupt()))
86 skb = alloc_skb(len + pfx, GFP_ATOMIC);
88 skb = alloc_skb(len + pfx, GFP_KERNEL);
90 if (unlikely(skb == NULL))
93 skb_reserve(skb, pfx);
94 return skb_to_pkt(skb);
97 inline struct cfpkt *cfpkt_create(u16 len)
99 return cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
102 void cfpkt_destroy(struct cfpkt *pkt)
104 struct sk_buff *skb = pkt_to_skb(pkt);
109 inline bool cfpkt_more(struct cfpkt *pkt)
111 struct sk_buff *skb = pkt_to_skb(pkt);
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);
127 int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len)
129 struct sk_buff *skb = pkt_to_skb(pkt);
131 if (unlikely(is_erronous(pkt)))
134 if (unlikely(len > skb->len)) {
135 PKT_ERROR(pkt, "read beyond end of packet\n");
139 if (unlikely(len > skb_headlen(skb))) {
140 if (unlikely(skb_linearize(skb) != 0)) {
141 PKT_ERROR(pkt, "linearize failed\n");
145 from = skb_pull(skb, len);
148 memcpy(data, from, len);
152 int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len)
154 struct sk_buff *skb = pkt_to_skb(pkt);
157 if (unlikely(is_erronous(pkt)))
160 if (unlikely(skb_linearize(skb) != 0)) {
161 PKT_ERROR(pkt, "linearize failed\n");
164 if (unlikely(skb->data + len > skb_tail_pointer(skb))) {
165 PKT_ERROR(pkt, "read beyond end of packet\n");
168 from = skb_tail_pointer(skb) - len;
169 skb_trim(skb, skb->len - len);
170 memcpy(data, from, len);
175 int cfpkt_pad_trail(struct cfpkt *pkt, u16 len)
177 return cfpkt_add_body(pkt, NULL, len);
181 int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len)
183 struct sk_buff *skb = pkt_to_skb(pkt);
184 struct sk_buff *lastskb;
189 if (unlikely(is_erronous(pkt)))
194 /* Check whether we need to add space at the tail */
195 if (unlikely(skb_tailroom(skb) < len)) {
196 if (likely(len < PKT_LEN_WHEN_EXTENDING))
197 addlen = PKT_LEN_WHEN_EXTENDING;
202 /* Check whether we need to change the SKB before writing to the tail */
203 if (unlikely((addlen > 0) || skb_cloned(skb) || skb_shared(skb))) {
205 /* Make sure data is writable */
206 if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) {
207 PKT_ERROR(pkt, "cow failed\n");
211 * Is the SKB non-linear after skb_cow_data()? If so, we are
212 * going to add data to the last SKB, so we need to adjust
213 * lengths of the top SKB.
215 if (lastskb != skb) {
216 pr_warn("Packet is non-linear\n");
218 skb->data_len += len;
222 /* All set to put the last SKB and optionally write data there. */
223 to = skb_put(lastskb, len);
225 memcpy(to, data, len);
229 inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data)
231 return cfpkt_add_body(pkt, &data, 1);
234 int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len)
236 struct sk_buff *skb = pkt_to_skb(pkt);
237 struct sk_buff *lastskb;
239 const u8 *data = data2;
241 if (unlikely(is_erronous(pkt)))
243 if (unlikely(skb_headroom(skb) < len)) {
244 PKT_ERROR(pkt, "no headroom\n");
248 /* Make sure data is writable */
249 ret = skb_cow_data(skb, 0, &lastskb);
250 if (unlikely(ret < 0)) {
251 PKT_ERROR(pkt, "cow failed\n");
255 to = skb_push(skb, len);
256 memcpy(to, data, len);
261 inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len)
263 return cfpkt_add_body(pkt, data, len);
267 inline u16 cfpkt_getlen(struct cfpkt *pkt)
269 struct sk_buff *skb = pkt_to_skb(pkt);
274 inline u16 cfpkt_iterate(struct cfpkt *pkt,
275 u16 (*iter_func)(u16, void *, u16),
279 * Don't care about the performance hit of linearizing,
280 * Checksum should not be used on high-speed interfaces anyway.
282 if (unlikely(is_erronous(pkt)))
284 if (unlikely(skb_linearize(&pkt->skb) != 0)) {
285 PKT_ERROR(pkt, "linearize failed\n");
288 return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt));
292 int cfpkt_setlen(struct cfpkt *pkt, u16 len)
294 struct sk_buff *skb = pkt_to_skb(pkt);
297 if (unlikely(is_erronous(pkt)))
300 if (likely(len <= skb->len)) {
301 if (unlikely(skb->data_len))
302 ___pskb_trim(skb, len);
306 return cfpkt_getlen(pkt);
309 /* Need to expand SKB */
310 if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len)))
311 PKT_ERROR(pkt, "skb_pad_trail failed\n");
313 return cfpkt_getlen(pkt);
316 struct cfpkt *cfpkt_append(struct cfpkt *dstpkt,
317 struct cfpkt *addpkt,
320 struct sk_buff *dst = pkt_to_skb(dstpkt);
321 struct sk_buff *add = pkt_to_skb(addpkt);
322 u16 addlen = skb_headlen(add);
327 if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) {
330 if (expectlen > addlen)
331 neededtailspace = expectlen;
333 neededtailspace = addlen;
335 if (dst->tail + neededtailspace > dst->end) {
336 /* Create a dumplicate of 'dst' with more tail space */
337 struct cfpkt *tmppkt;
338 dstlen = skb_headlen(dst);
339 createlen = dstlen + neededtailspace;
340 tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX);
343 tmp = pkt_to_skb(tmppkt);
344 skb_set_tail_pointer(tmp, dstlen);
346 memcpy(tmp->data, dst->data, dstlen);
347 cfpkt_destroy(dstpkt);
350 memcpy(skb_tail_pointer(dst), add->data, skb_headlen(add));
351 cfpkt_destroy(addpkt);
354 return skb_to_pkt(dst);
357 struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos)
359 struct sk_buff *skb2;
360 struct sk_buff *skb = pkt_to_skb(pkt);
361 struct cfpkt *tmppkt;
362 u8 *split = skb->data + pos;
363 u16 len2nd = skb_tail_pointer(skb) - split;
365 if (unlikely(is_erronous(pkt)))
368 if (skb->data + pos > skb_tail_pointer(skb)) {
369 PKT_ERROR(pkt, "trying to split beyond end of packet\n");
373 /* Create a new packet for the second part of the data */
374 tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX,
378 skb2 = pkt_to_skb(tmppkt);
384 /* Reduce the length of the original packet */
385 skb_set_tail_pointer(skb, pos);
388 memcpy(skb2->data, split, len2nd);
389 skb2->tail += len2nd;
391 return skb_to_pkt(skb2);
394 bool cfpkt_erroneous(struct cfpkt *pkt)
396 return cfpkt_priv(pkt)->erronous;
399 struct caif_payload_info *cfpkt_info(struct cfpkt *pkt)
401 return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb;