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> | |
bc3b2d7f | 11 | #include <linux/export.h> |
15c9ac0c SB |
12 | #include <net/caif/cfpkt.h> |
13 | ||
24e263ad | 14 | #define PKT_PREFIX 48 |
2aa40aef | 15 | #define PKT_POSTFIX 2 |
15c9ac0c | 16 | #define PKT_LEN_WHEN_EXTENDING 128 |
b31fa5ba JP |
17 | #define PKT_ERROR(pkt, errmsg) \ |
18 | do { \ | |
19 | cfpkt_priv(pkt)->erronous = true; \ | |
20 | skb_reset_tail_pointer(&pkt->skb); \ | |
21 | pr_warn(errmsg); \ | |
22 | } while (0) | |
15c9ac0c SB |
23 | |
24 | struct cfpktq { | |
25 | struct sk_buff_head head; | |
26 | atomic_t count; | |
27 | /* Lock protects count updates */ | |
28 | spinlock_t lock; | |
29 | }; | |
30 | ||
31 | /* | |
32 | * net/caif/ is generic and does not | |
33 | * understand SKB, so we do this typecast | |
34 | */ | |
35 | struct cfpkt { | |
36 | struct sk_buff skb; | |
37 | }; | |
38 | ||
39 | /* Private data inside SKB */ | |
40 | struct cfpkt_priv_data { | |
41 | struct dev_info dev_info; | |
42 | bool erronous; | |
43 | }; | |
44 | ||
73d6ac63 | 45 | static inline struct cfpkt_priv_data *cfpkt_priv(struct cfpkt *pkt) |
15c9ac0c SB |
46 | { |
47 | return (struct cfpkt_priv_data *) pkt->skb.cb; | |
48 | } | |
49 | ||
73d6ac63 | 50 | static inline bool is_erronous(struct cfpkt *pkt) |
15c9ac0c SB |
51 | { |
52 | return cfpkt_priv(pkt)->erronous; | |
53 | } | |
54 | ||
73d6ac63 | 55 | static inline struct sk_buff *pkt_to_skb(struct cfpkt *pkt) |
15c9ac0c SB |
56 | { |
57 | return &pkt->skb; | |
58 | } | |
59 | ||
73d6ac63 | 60 | static inline struct cfpkt *skb_to_pkt(struct sk_buff *skb) |
15c9ac0c SB |
61 | { |
62 | return (struct cfpkt *) skb; | |
63 | } | |
64 | ||
15c9ac0c SB |
65 | struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt) |
66 | { | |
67 | struct cfpkt *pkt = skb_to_pkt(nativepkt); | |
68 | cfpkt_priv(pkt)->erronous = false; | |
69 | return pkt; | |
70 | } | |
71 | EXPORT_SYMBOL(cfpkt_fromnative); | |
72 | ||
73 | void *cfpkt_tonative(struct cfpkt *pkt) | |
74 | { | |
75 | return (void *) pkt; | |
76 | } | |
77 | EXPORT_SYMBOL(cfpkt_tonative); | |
78 | ||
79 | static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx) | |
80 | { | |
81 | struct sk_buff *skb; | |
82 | ||
f146e872 | 83 | skb = alloc_skb(len + pfx, GFP_ATOMIC); |
15c9ac0c SB |
84 | if (unlikely(skb == NULL)) |
85 | return NULL; | |
86 | ||
87 | skb_reserve(skb, pfx); | |
88 | return skb_to_pkt(skb); | |
89 | } | |
90 | ||
91 | inline struct cfpkt *cfpkt_create(u16 len) | |
92 | { | |
93 | return cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX); | |
94 | } | |
15c9ac0c SB |
95 | |
96 | void cfpkt_destroy(struct cfpkt *pkt) | |
97 | { | |
98 | struct sk_buff *skb = pkt_to_skb(pkt); | |
99 | kfree_skb(skb); | |
100 | } | |
3f874adc | 101 | |
15c9ac0c SB |
102 | inline bool cfpkt_more(struct cfpkt *pkt) |
103 | { | |
104 | struct sk_buff *skb = pkt_to_skb(pkt); | |
105 | return skb->len > 0; | |
106 | } | |
3f874adc | 107 | |
15c9ac0c SB |
108 | int cfpkt_peek_head(struct cfpkt *pkt, void *data, u16 len) |
109 | { | |
110 | struct sk_buff *skb = pkt_to_skb(pkt); | |
111 | if (skb_headlen(skb) >= len) { | |
112 | memcpy(data, skb->data, len); | |
113 | return 0; | |
114 | } | |
115 | return !cfpkt_extr_head(pkt, data, len) && | |
116 | !cfpkt_add_head(pkt, data, len); | |
117 | } | |
15c9ac0c SB |
118 | |
119 | int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len) | |
120 | { | |
121 | struct sk_buff *skb = pkt_to_skb(pkt); | |
122 | u8 *from; | |
123 | if (unlikely(is_erronous(pkt))) | |
124 | return -EPROTO; | |
125 | ||
126 | if (unlikely(len > skb->len)) { | |
b31fa5ba | 127 | PKT_ERROR(pkt, "read beyond end of packet\n"); |
15c9ac0c SB |
128 | return -EPROTO; |
129 | } | |
130 | ||
131 | if (unlikely(len > skb_headlen(skb))) { | |
132 | if (unlikely(skb_linearize(skb) != 0)) { | |
b31fa5ba | 133 | PKT_ERROR(pkt, "linearize failed\n"); |
15c9ac0c SB |
134 | return -EPROTO; |
135 | } | |
136 | } | |
137 | from = skb_pull(skb, len); | |
138 | from -= len; | |
200c5a3b | 139 | if (data) |
140 | memcpy(data, from, len); | |
15c9ac0c SB |
141 | return 0; |
142 | } | |
7ad65bf6 | 143 | EXPORT_SYMBOL(cfpkt_extr_head); |
15c9ac0c SB |
144 | |
145 | int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len) | |
146 | { | |
147 | struct sk_buff *skb = pkt_to_skb(pkt); | |
148 | u8 *data = dta; | |
149 | u8 *from; | |
150 | if (unlikely(is_erronous(pkt))) | |
151 | return -EPROTO; | |
152 | ||
153 | if (unlikely(skb_linearize(skb) != 0)) { | |
b31fa5ba | 154 | PKT_ERROR(pkt, "linearize failed\n"); |
15c9ac0c SB |
155 | return -EPROTO; |
156 | } | |
157 | if (unlikely(skb->data + len > skb_tail_pointer(skb))) { | |
b31fa5ba | 158 | PKT_ERROR(pkt, "read beyond end of packet\n"); |
15c9ac0c SB |
159 | return -EPROTO; |
160 | } | |
161 | from = skb_tail_pointer(skb) - len; | |
162 | skb_trim(skb, skb->len - len); | |
163 | memcpy(data, from, len); | |
164 | return 0; | |
165 | } | |
3f874adc | 166 | |
15c9ac0c SB |
167 | int cfpkt_pad_trail(struct cfpkt *pkt, u16 len) |
168 | { | |
169 | return cfpkt_add_body(pkt, NULL, len); | |
170 | } | |
3f874adc | 171 | |
15c9ac0c SB |
172 | int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len) |
173 | { | |
174 | struct sk_buff *skb = pkt_to_skb(pkt); | |
175 | struct sk_buff *lastskb; | |
176 | u8 *to; | |
177 | u16 addlen = 0; | |
178 | ||
179 | ||
180 | if (unlikely(is_erronous(pkt))) | |
181 | return -EPROTO; | |
182 | ||
183 | lastskb = skb; | |
184 | ||
185 | /* Check whether we need to add space at the tail */ | |
186 | if (unlikely(skb_tailroom(skb) < len)) { | |
187 | if (likely(len < PKT_LEN_WHEN_EXTENDING)) | |
188 | addlen = PKT_LEN_WHEN_EXTENDING; | |
189 | else | |
190 | addlen = len; | |
191 | } | |
192 | ||
193 | /* Check whether we need to change the SKB before writing to the tail */ | |
194 | if (unlikely((addlen > 0) || skb_cloned(skb) || skb_shared(skb))) { | |
195 | ||
196 | /* Make sure data is writable */ | |
197 | if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) { | |
b31fa5ba | 198 | PKT_ERROR(pkt, "cow failed\n"); |
15c9ac0c SB |
199 | return -EPROTO; |
200 | } | |
15c9ac0c SB |
201 | } |
202 | ||
203 | /* All set to put the last SKB and optionally write data there. */ | |
253c6daa | 204 | to = pskb_put(skb, lastskb, len); |
15c9ac0c SB |
205 | if (likely(data)) |
206 | memcpy(to, data, len); | |
207 | return 0; | |
208 | } | |
15c9ac0c SB |
209 | |
210 | inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data) | |
211 | { | |
212 | return cfpkt_add_body(pkt, &data, 1); | |
213 | } | |
15c9ac0c SB |
214 | |
215 | int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len) | |
216 | { | |
217 | struct sk_buff *skb = pkt_to_skb(pkt); | |
218 | struct sk_buff *lastskb; | |
219 | u8 *to; | |
220 | const u8 *data = data2; | |
638e628a | 221 | int ret; |
15c9ac0c SB |
222 | if (unlikely(is_erronous(pkt))) |
223 | return -EPROTO; | |
224 | if (unlikely(skb_headroom(skb) < len)) { | |
b31fa5ba | 225 | PKT_ERROR(pkt, "no headroom\n"); |
15c9ac0c SB |
226 | return -EPROTO; |
227 | } | |
228 | ||
229 | /* Make sure data is writable */ | |
638e628a SB |
230 | ret = skb_cow_data(skb, 0, &lastskb); |
231 | if (unlikely(ret < 0)) { | |
b31fa5ba | 232 | PKT_ERROR(pkt, "cow failed\n"); |
638e628a | 233 | return ret; |
15c9ac0c SB |
234 | } |
235 | ||
236 | to = skb_push(skb, len); | |
237 | memcpy(to, data, len); | |
238 | return 0; | |
239 | } | |
7ad65bf6 | 240 | EXPORT_SYMBOL(cfpkt_add_head); |
15c9ac0c SB |
241 | |
242 | inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len) | |
243 | { | |
244 | return cfpkt_add_body(pkt, data, len); | |
245 | } | |
3f874adc | 246 | |
15c9ac0c SB |
247 | inline u16 cfpkt_getlen(struct cfpkt *pkt) |
248 | { | |
249 | struct sk_buff *skb = pkt_to_skb(pkt); | |
250 | return skb->len; | |
251 | } | |
3f874adc | 252 | |
278f7b4f DC |
253 | int cfpkt_iterate(struct cfpkt *pkt, |
254 | u16 (*iter_func)(u16, void *, u16), | |
255 | u16 data) | |
15c9ac0c SB |
256 | { |
257 | /* | |
258 | * Don't care about the performance hit of linearizing, | |
259 | * Checksum should not be used on high-speed interfaces anyway. | |
260 | */ | |
261 | if (unlikely(is_erronous(pkt))) | |
262 | return -EPROTO; | |
263 | if (unlikely(skb_linearize(&pkt->skb) != 0)) { | |
b31fa5ba | 264 | PKT_ERROR(pkt, "linearize failed\n"); |
15c9ac0c SB |
265 | return -EPROTO; |
266 | } | |
267 | return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt)); | |
268 | } | |
3f874adc | 269 | |
15c9ac0c SB |
270 | int cfpkt_setlen(struct cfpkt *pkt, u16 len) |
271 | { | |
272 | struct sk_buff *skb = pkt_to_skb(pkt); | |
273 | ||
274 | ||
275 | if (unlikely(is_erronous(pkt))) | |
276 | return -EPROTO; | |
277 | ||
278 | if (likely(len <= skb->len)) { | |
279 | if (unlikely(skb->data_len)) | |
280 | ___pskb_trim(skb, len); | |
281 | else | |
282 | skb_trim(skb, len); | |
283 | ||
8e0cc8c3 | 284 | return cfpkt_getlen(pkt); |
15c9ac0c SB |
285 | } |
286 | ||
287 | /* Need to expand SKB */ | |
288 | if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len))) | |
b31fa5ba | 289 | PKT_ERROR(pkt, "skb_pad_trail failed\n"); |
15c9ac0c SB |
290 | |
291 | return cfpkt_getlen(pkt); | |
292 | } | |
15c9ac0c | 293 | |
15c9ac0c | 294 | struct cfpkt *cfpkt_append(struct cfpkt *dstpkt, |
3bffc475 SMP |
295 | struct cfpkt *addpkt, |
296 | u16 expectlen) | |
15c9ac0c SB |
297 | { |
298 | struct sk_buff *dst = pkt_to_skb(dstpkt); | |
299 | struct sk_buff *add = pkt_to_skb(addpkt); | |
300 | u16 addlen = skb_headlen(add); | |
301 | u16 neededtailspace; | |
302 | struct sk_buff *tmp; | |
303 | u16 dstlen; | |
304 | u16 createlen; | |
305 | if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) { | |
15c9ac0c SB |
306 | return dstpkt; |
307 | } | |
308 | if (expectlen > addlen) | |
309 | neededtailspace = expectlen; | |
310 | else | |
311 | neededtailspace = addlen; | |
312 | ||
313 | if (dst->tail + neededtailspace > dst->end) { | |
314 | /* Create a dumplicate of 'dst' with more tail space */ | |
638e628a | 315 | struct cfpkt *tmppkt; |
15c9ac0c SB |
316 | dstlen = skb_headlen(dst); |
317 | createlen = dstlen + neededtailspace; | |
638e628a SB |
318 | tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX); |
319 | if (tmppkt == NULL) | |
15c9ac0c | 320 | return NULL; |
638e628a | 321 | tmp = pkt_to_skb(tmppkt); |
1eb00162 | 322 | skb_put_data(tmp, dst->data, dstlen); |
15c9ac0c SB |
323 | cfpkt_destroy(dstpkt); |
324 | dst = tmp; | |
325 | } | |
1eb00162 | 326 | skb_put_data(dst, add->data, skb_headlen(add)); |
15c9ac0c | 327 | cfpkt_destroy(addpkt); |
15c9ac0c SB |
328 | return skb_to_pkt(dst); |
329 | } | |
15c9ac0c SB |
330 | |
331 | struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos) | |
332 | { | |
333 | struct sk_buff *skb2; | |
334 | struct sk_buff *skb = pkt_to_skb(pkt); | |
638e628a | 335 | struct cfpkt *tmppkt; |
15c9ac0c SB |
336 | u8 *split = skb->data + pos; |
337 | u16 len2nd = skb_tail_pointer(skb) - split; | |
338 | ||
339 | if (unlikely(is_erronous(pkt))) | |
340 | return NULL; | |
341 | ||
342 | if (skb->data + pos > skb_tail_pointer(skb)) { | |
b31fa5ba | 343 | PKT_ERROR(pkt, "trying to split beyond end of packet\n"); |
15c9ac0c SB |
344 | return NULL; |
345 | } | |
346 | ||
347 | /* Create a new packet for the second part of the data */ | |
638e628a SB |
348 | tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX, |
349 | PKT_PREFIX); | |
350 | if (tmppkt == NULL) | |
351 | return NULL; | |
352 | skb2 = pkt_to_skb(tmppkt); | |
353 | ||
15c9ac0c SB |
354 | |
355 | if (skb2 == NULL) | |
356 | return NULL; | |
357 | ||
1eb00162 JH |
358 | skb_put_data(skb2, split, len2nd); |
359 | ||
15c9ac0c | 360 | /* Reduce the length of the original packet */ |
1eb00162 | 361 | skb_trim(skb, pos); |
15c9ac0c | 362 | |
44764812 | 363 | skb2->priority = skb->priority; |
15c9ac0c SB |
364 | return skb_to_pkt(skb2); |
365 | } | |
15c9ac0c | 366 | |
73d6ac63 | 367 | bool cfpkt_erroneous(struct cfpkt *pkt) |
15c9ac0c SB |
368 | { |
369 | return cfpkt_priv(pkt)->erronous; | |
370 | } | |
15c9ac0c SB |
371 | |
372 | struct caif_payload_info *cfpkt_info(struct cfpkt *pkt) | |
373 | { | |
374 | return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb; | |
375 | } | |
7ad65bf6 | 376 | EXPORT_SYMBOL(cfpkt_info); |
44764812 DT |
377 | |
378 | void cfpkt_set_prio(struct cfpkt *pkt, int prio) | |
379 | { | |
380 | pkt_to_skb(pkt)->priority = prio; | |
381 | } | |
382 | EXPORT_SYMBOL(cfpkt_set_prio); |