Commit | Line | Data |
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15c9ac0c SB |
1 | /* |
2 | * Copyright (C) ST-Ericsson AB 2010 | |
26ee65e6 | 3 | * Author: Sjur Brendeland |
15c9ac0c SB |
4 | * License terms: GNU General Public License (GPL) version 2 |
5 | */ | |
6 | ||
b31fa5ba JP |
7 | #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ |
8 | ||
15c9ac0c SB |
9 | #include <linux/string.h> |
10 | #include <linux/skbuff.h> | |
11 | #include <linux/hardirq.h> | |
bc3b2d7f | 12 | #include <linux/export.h> |
15c9ac0c SB |
13 | #include <net/caif/cfpkt.h> |
14 | ||
24e263ad | 15 | #define PKT_PREFIX 48 |
2aa40aef | 16 | #define PKT_POSTFIX 2 |
15c9ac0c | 17 | #define PKT_LEN_WHEN_EXTENDING 128 |
b31fa5ba JP |
18 | #define PKT_ERROR(pkt, errmsg) \ |
19 | do { \ | |
20 | cfpkt_priv(pkt)->erronous = true; \ | |
21 | skb_reset_tail_pointer(&pkt->skb); \ | |
22 | pr_warn(errmsg); \ | |
23 | } while (0) | |
15c9ac0c SB |
24 | |
25 | struct cfpktq { | |
26 | struct sk_buff_head head; | |
27 | atomic_t count; | |
28 | /* Lock protects count updates */ | |
29 | spinlock_t lock; | |
30 | }; | |
31 | ||
32 | /* | |
33 | * net/caif/ is generic and does not | |
34 | * understand SKB, so we do this typecast | |
35 | */ | |
36 | struct cfpkt { | |
37 | struct sk_buff skb; | |
38 | }; | |
39 | ||
40 | /* Private data inside SKB */ | |
41 | struct cfpkt_priv_data { | |
42 | struct dev_info dev_info; | |
43 | bool erronous; | |
44 | }; | |
45 | ||
73d6ac63 | 46 | static inline struct cfpkt_priv_data *cfpkt_priv(struct cfpkt *pkt) |
15c9ac0c SB |
47 | { |
48 | return (struct cfpkt_priv_data *) pkt->skb.cb; | |
49 | } | |
50 | ||
73d6ac63 | 51 | static inline bool is_erronous(struct cfpkt *pkt) |
15c9ac0c SB |
52 | { |
53 | return cfpkt_priv(pkt)->erronous; | |
54 | } | |
55 | ||
73d6ac63 | 56 | static inline struct sk_buff *pkt_to_skb(struct cfpkt *pkt) |
15c9ac0c SB |
57 | { |
58 | return &pkt->skb; | |
59 | } | |
60 | ||
73d6ac63 | 61 | static inline struct cfpkt *skb_to_pkt(struct sk_buff *skb) |
15c9ac0c SB |
62 | { |
63 | return (struct cfpkt *) skb; | |
64 | } | |
65 | ||
15c9ac0c SB |
66 | struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt) |
67 | { | |
68 | struct cfpkt *pkt = skb_to_pkt(nativepkt); | |
69 | cfpkt_priv(pkt)->erronous = false; | |
70 | return pkt; | |
71 | } | |
72 | EXPORT_SYMBOL(cfpkt_fromnative); | |
73 | ||
74 | void *cfpkt_tonative(struct cfpkt *pkt) | |
75 | { | |
76 | return (void *) pkt; | |
77 | } | |
78 | EXPORT_SYMBOL(cfpkt_tonative); | |
79 | ||
80 | static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx) | |
81 | { | |
82 | struct sk_buff *skb; | |
83 | ||
84 | if (likely(in_interrupt())) | |
85 | skb = alloc_skb(len + pfx, GFP_ATOMIC); | |
86 | else | |
87 | skb = alloc_skb(len + pfx, GFP_KERNEL); | |
88 | ||
89 | if (unlikely(skb == NULL)) | |
90 | return NULL; | |
91 | ||
92 | skb_reserve(skb, pfx); | |
93 | return skb_to_pkt(skb); | |
94 | } | |
95 | ||
96 | inline struct cfpkt *cfpkt_create(u16 len) | |
97 | { | |
98 | return cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX); | |
99 | } | |
15c9ac0c SB |
100 | |
101 | void cfpkt_destroy(struct cfpkt *pkt) | |
102 | { | |
103 | struct sk_buff *skb = pkt_to_skb(pkt); | |
104 | kfree_skb(skb); | |
105 | } | |
3f874adc | 106 | |
15c9ac0c SB |
107 | inline bool cfpkt_more(struct cfpkt *pkt) |
108 | { | |
109 | struct sk_buff *skb = pkt_to_skb(pkt); | |
110 | return skb->len > 0; | |
111 | } | |
3f874adc | 112 | |
15c9ac0c SB |
113 | int 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 | } | |
15c9ac0c SB |
123 | |
124 | int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len) | |
125 | { | |
126 | struct sk_buff *skb = pkt_to_skb(pkt); | |
127 | u8 *from; | |
128 | if (unlikely(is_erronous(pkt))) | |
129 | return -EPROTO; | |
130 | ||
131 | if (unlikely(len > skb->len)) { | |
b31fa5ba | 132 | PKT_ERROR(pkt, "read beyond end of packet\n"); |
15c9ac0c SB |
133 | return -EPROTO; |
134 | } | |
135 | ||
136 | if (unlikely(len > skb_headlen(skb))) { | |
137 | if (unlikely(skb_linearize(skb) != 0)) { | |
b31fa5ba | 138 | PKT_ERROR(pkt, "linearize failed\n"); |
15c9ac0c SB |
139 | return -EPROTO; |
140 | } | |
141 | } | |
142 | from = skb_pull(skb, len); | |
143 | from -= len; | |
200c5a3b | 144 | if (data) |
145 | memcpy(data, from, len); | |
15c9ac0c SB |
146 | return 0; |
147 | } | |
7ad65bf6 | 148 | EXPORT_SYMBOL(cfpkt_extr_head); |
15c9ac0c SB |
149 | |
150 | int 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)) { | |
b31fa5ba | 159 | PKT_ERROR(pkt, "linearize failed\n"); |
15c9ac0c SB |
160 | return -EPROTO; |
161 | } | |
162 | if (unlikely(skb->data + len > skb_tail_pointer(skb))) { | |
b31fa5ba | 163 | PKT_ERROR(pkt, "read beyond end of packet\n"); |
15c9ac0c SB |
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 | } | |
3f874adc | 171 | |
15c9ac0c SB |
172 | int cfpkt_pad_trail(struct cfpkt *pkt, u16 len) |
173 | { | |
174 | return cfpkt_add_body(pkt, NULL, len); | |
175 | } | |
3f874adc | 176 | |
15c9ac0c SB |
177 | int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len) |
178 | { | |
179 | struct sk_buff *skb = pkt_to_skb(pkt); | |
180 | struct sk_buff *lastskb; | |
181 | u8 *to; | |
182 | u16 addlen = 0; | |
183 | ||
184 | ||
185 | if (unlikely(is_erronous(pkt))) | |
186 | return -EPROTO; | |
187 | ||
188 | lastskb = skb; | |
189 | ||
190 | /* Check whether we need to add space at the tail */ | |
191 | if (unlikely(skb_tailroom(skb) < len)) { | |
192 | if (likely(len < PKT_LEN_WHEN_EXTENDING)) | |
193 | addlen = PKT_LEN_WHEN_EXTENDING; | |
194 | else | |
195 | addlen = len; | |
196 | } | |
197 | ||
198 | /* Check whether we need to change the SKB before writing to the tail */ | |
199 | if (unlikely((addlen > 0) || skb_cloned(skb) || skb_shared(skb))) { | |
200 | ||
201 | /* Make sure data is writable */ | |
202 | if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) { | |
b31fa5ba | 203 | PKT_ERROR(pkt, "cow failed\n"); |
15c9ac0c SB |
204 | return -EPROTO; |
205 | } | |
15c9ac0c SB |
206 | } |
207 | ||
208 | /* All set to put the last SKB and optionally write data there. */ | |
253c6daa | 209 | to = pskb_put(skb, lastskb, len); |
15c9ac0c SB |
210 | if (likely(data)) |
211 | memcpy(to, data, len); | |
212 | return 0; | |
213 | } | |
15c9ac0c SB |
214 | |
215 | inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data) | |
216 | { | |
217 | return cfpkt_add_body(pkt, &data, 1); | |
218 | } | |
15c9ac0c SB |
219 | |
220 | int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len) | |
221 | { | |
222 | struct sk_buff *skb = pkt_to_skb(pkt); | |
223 | struct sk_buff *lastskb; | |
224 | u8 *to; | |
225 | const u8 *data = data2; | |
638e628a | 226 | int ret; |
15c9ac0c SB |
227 | if (unlikely(is_erronous(pkt))) |
228 | return -EPROTO; | |
229 | if (unlikely(skb_headroom(skb) < len)) { | |
b31fa5ba | 230 | PKT_ERROR(pkt, "no headroom\n"); |
15c9ac0c SB |
231 | return -EPROTO; |
232 | } | |
233 | ||
234 | /* Make sure data is writable */ | |
638e628a SB |
235 | ret = skb_cow_data(skb, 0, &lastskb); |
236 | if (unlikely(ret < 0)) { | |
b31fa5ba | 237 | PKT_ERROR(pkt, "cow failed\n"); |
638e628a | 238 | return ret; |
15c9ac0c SB |
239 | } |
240 | ||
241 | to = skb_push(skb, len); | |
242 | memcpy(to, data, len); | |
243 | return 0; | |
244 | } | |
7ad65bf6 | 245 | EXPORT_SYMBOL(cfpkt_add_head); |
15c9ac0c SB |
246 | |
247 | inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len) | |
248 | { | |
249 | return cfpkt_add_body(pkt, data, len); | |
250 | } | |
3f874adc | 251 | |
15c9ac0c SB |
252 | inline u16 cfpkt_getlen(struct cfpkt *pkt) |
253 | { | |
254 | struct sk_buff *skb = pkt_to_skb(pkt); | |
255 | return skb->len; | |
256 | } | |
3f874adc | 257 | |
278f7b4f DC |
258 | int cfpkt_iterate(struct cfpkt *pkt, |
259 | u16 (*iter_func)(u16, void *, u16), | |
260 | u16 data) | |
15c9ac0c SB |
261 | { |
262 | /* | |
263 | * Don't care about the performance hit of linearizing, | |
264 | * Checksum should not be used on high-speed interfaces anyway. | |
265 | */ | |
266 | if (unlikely(is_erronous(pkt))) | |
267 | return -EPROTO; | |
268 | if (unlikely(skb_linearize(&pkt->skb) != 0)) { | |
b31fa5ba | 269 | PKT_ERROR(pkt, "linearize failed\n"); |
15c9ac0c SB |
270 | return -EPROTO; |
271 | } | |
272 | return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt)); | |
273 | } | |
3f874adc | 274 | |
15c9ac0c SB |
275 | int cfpkt_setlen(struct cfpkt *pkt, u16 len) |
276 | { | |
277 | struct sk_buff *skb = pkt_to_skb(pkt); | |
278 | ||
279 | ||
280 | if (unlikely(is_erronous(pkt))) | |
281 | return -EPROTO; | |
282 | ||
283 | if (likely(len <= skb->len)) { | |
284 | if (unlikely(skb->data_len)) | |
285 | ___pskb_trim(skb, len); | |
286 | else | |
287 | skb_trim(skb, len); | |
288 | ||
289 | return cfpkt_getlen(pkt); | |
290 | } | |
291 | ||
292 | /* Need to expand SKB */ | |
293 | if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len))) | |
b31fa5ba | 294 | PKT_ERROR(pkt, "skb_pad_trail failed\n"); |
15c9ac0c SB |
295 | |
296 | return cfpkt_getlen(pkt); | |
297 | } | |
15c9ac0c | 298 | |
15c9ac0c | 299 | struct cfpkt *cfpkt_append(struct cfpkt *dstpkt, |
3bffc475 SMP |
300 | struct cfpkt *addpkt, |
301 | u16 expectlen) | |
15c9ac0c SB |
302 | { |
303 | struct sk_buff *dst = pkt_to_skb(dstpkt); | |
304 | struct sk_buff *add = pkt_to_skb(addpkt); | |
305 | u16 addlen = skb_headlen(add); | |
306 | u16 neededtailspace; | |
307 | struct sk_buff *tmp; | |
308 | u16 dstlen; | |
309 | u16 createlen; | |
310 | if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) { | |
15c9ac0c SB |
311 | return dstpkt; |
312 | } | |
313 | if (expectlen > addlen) | |
314 | neededtailspace = expectlen; | |
315 | else | |
316 | neededtailspace = addlen; | |
317 | ||
318 | if (dst->tail + neededtailspace > dst->end) { | |
319 | /* Create a dumplicate of 'dst' with more tail space */ | |
638e628a | 320 | struct cfpkt *tmppkt; |
15c9ac0c SB |
321 | dstlen = skb_headlen(dst); |
322 | createlen = dstlen + neededtailspace; | |
638e628a SB |
323 | tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX); |
324 | if (tmppkt == NULL) | |
15c9ac0c | 325 | return NULL; |
638e628a | 326 | tmp = pkt_to_skb(tmppkt); |
15c9ac0c SB |
327 | skb_set_tail_pointer(tmp, dstlen); |
328 | tmp->len = dstlen; | |
329 | memcpy(tmp->data, dst->data, dstlen); | |
330 | cfpkt_destroy(dstpkt); | |
331 | dst = tmp; | |
332 | } | |
333 | memcpy(skb_tail_pointer(dst), add->data, skb_headlen(add)); | |
334 | cfpkt_destroy(addpkt); | |
335 | dst->tail += addlen; | |
336 | dst->len += addlen; | |
337 | return skb_to_pkt(dst); | |
338 | } | |
15c9ac0c SB |
339 | |
340 | struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos) | |
341 | { | |
342 | struct sk_buff *skb2; | |
343 | struct sk_buff *skb = pkt_to_skb(pkt); | |
638e628a | 344 | struct cfpkt *tmppkt; |
15c9ac0c SB |
345 | u8 *split = skb->data + pos; |
346 | u16 len2nd = skb_tail_pointer(skb) - split; | |
347 | ||
348 | if (unlikely(is_erronous(pkt))) | |
349 | return NULL; | |
350 | ||
351 | if (skb->data + pos > skb_tail_pointer(skb)) { | |
b31fa5ba | 352 | PKT_ERROR(pkt, "trying to split beyond end of packet\n"); |
15c9ac0c SB |
353 | return NULL; |
354 | } | |
355 | ||
356 | /* Create a new packet for the second part of the data */ | |
638e628a SB |
357 | tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX, |
358 | PKT_PREFIX); | |
359 | if (tmppkt == NULL) | |
360 | return NULL; | |
361 | skb2 = pkt_to_skb(tmppkt); | |
362 | ||
15c9ac0c SB |
363 | |
364 | if (skb2 == NULL) | |
365 | return NULL; | |
366 | ||
367 | /* Reduce the length of the original packet */ | |
368 | skb_set_tail_pointer(skb, pos); | |
369 | skb->len = pos; | |
370 | ||
371 | memcpy(skb2->data, split, len2nd); | |
372 | skb2->tail += len2nd; | |
373 | skb2->len += len2nd; | |
44764812 | 374 | skb2->priority = skb->priority; |
15c9ac0c SB |
375 | return skb_to_pkt(skb2); |
376 | } | |
15c9ac0c | 377 | |
73d6ac63 | 378 | bool cfpkt_erroneous(struct cfpkt *pkt) |
15c9ac0c SB |
379 | { |
380 | return cfpkt_priv(pkt)->erronous; | |
381 | } | |
15c9ac0c SB |
382 | |
383 | struct caif_payload_info *cfpkt_info(struct cfpkt *pkt) | |
384 | { | |
385 | return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb; | |
386 | } | |
7ad65bf6 | 387 | EXPORT_SYMBOL(cfpkt_info); |
44764812 DT |
388 | |
389 | void cfpkt_set_prio(struct cfpkt *pkt, int prio) | |
390 | { | |
391 | pkt_to_skb(pkt)->priority = prio; | |
392 | } | |
393 | EXPORT_SYMBOL(cfpkt_set_prio); |