Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * SUCS NET3: | |
3 | * | |
4 | * Generic datagram handling routines. These are generic for all | |
5 | * protocols. Possibly a generic IP version on top of these would | |
6 | * make sense. Not tonight however 8-). | |
7 | * This is used because UDP, RAW, PACKET, DDP, IPX, AX.25 and | |
8 | * NetROM layer all have identical poll code and mostly | |
9 | * identical recvmsg() code. So we share it here. The poll was | |
10 | * shared before but buried in udp.c so I moved it. | |
11 | * | |
113aa838 | 12 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>. (datagram_poll() from old |
1da177e4 LT |
13 | * udp.c code) |
14 | * | |
15 | * Fixes: | |
16 | * Alan Cox : NULL return from skb_peek_copy() | |
17 | * understood | |
18 | * Alan Cox : Rewrote skb_read_datagram to avoid the | |
19 | * skb_peek_copy stuff. | |
20 | * Alan Cox : Added support for SOCK_SEQPACKET. | |
21 | * IPX can no longer use the SO_TYPE hack | |
22 | * but AX.25 now works right, and SPX is | |
23 | * feasible. | |
24 | * Alan Cox : Fixed write poll of non IP protocol | |
25 | * crash. | |
26 | * Florian La Roche: Changed for my new skbuff handling. | |
27 | * Darryl Miles : Fixed non-blocking SOCK_SEQPACKET. | |
28 | * Linus Torvalds : BSD semantic fixes. | |
29 | * Alan Cox : Datagram iovec handling | |
30 | * Darryl Miles : Fixed non-blocking SOCK_STREAM. | |
31 | * Alan Cox : POSIXisms | |
32 | * Pete Wyckoff : Unconnected accept() fix. | |
33 | * | |
34 | */ | |
35 | ||
36 | #include <linux/module.h> | |
37 | #include <linux/types.h> | |
38 | #include <linux/kernel.h> | |
39 | #include <asm/uaccess.h> | |
40 | #include <asm/system.h> | |
41 | #include <linux/mm.h> | |
42 | #include <linux/interrupt.h> | |
43 | #include <linux/errno.h> | |
44 | #include <linux/sched.h> | |
45 | #include <linux/inet.h> | |
1da177e4 LT |
46 | #include <linux/netdevice.h> |
47 | #include <linux/rtnetlink.h> | |
48 | #include <linux/poll.h> | |
49 | #include <linux/highmem.h> | |
3305b80c | 50 | #include <linux/spinlock.h> |
1da177e4 LT |
51 | |
52 | #include <net/protocol.h> | |
53 | #include <linux/skbuff.h> | |
1da177e4 | 54 | |
c752f073 ACM |
55 | #include <net/checksum.h> |
56 | #include <net/sock.h> | |
57 | #include <net/tcp_states.h> | |
1da177e4 LT |
58 | |
59 | /* | |
60 | * Is a socket 'connection oriented' ? | |
61 | */ | |
62 | static inline int connection_based(struct sock *sk) | |
63 | { | |
64 | return sk->sk_type == SOCK_SEQPACKET || sk->sk_type == SOCK_STREAM; | |
65 | } | |
66 | ||
67 | /* | |
68 | * Wait for a packet.. | |
69 | */ | |
70 | static int wait_for_packet(struct sock *sk, int *err, long *timeo_p) | |
71 | { | |
72 | int error; | |
73 | DEFINE_WAIT(wait); | |
74 | ||
75 | prepare_to_wait_exclusive(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); | |
76 | ||
77 | /* Socket errors? */ | |
78 | error = sock_error(sk); | |
79 | if (error) | |
80 | goto out_err; | |
81 | ||
82 | if (!skb_queue_empty(&sk->sk_receive_queue)) | |
83 | goto out; | |
84 | ||
85 | /* Socket shut down? */ | |
86 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
87 | goto out_noerr; | |
88 | ||
89 | /* Sequenced packets can come disconnected. | |
90 | * If so we report the problem | |
91 | */ | |
92 | error = -ENOTCONN; | |
93 | if (connection_based(sk) && | |
94 | !(sk->sk_state == TCP_ESTABLISHED || sk->sk_state == TCP_LISTEN)) | |
95 | goto out_err; | |
96 | ||
97 | /* handle signals */ | |
98 | if (signal_pending(current)) | |
99 | goto interrupted; | |
100 | ||
101 | error = 0; | |
102 | *timeo_p = schedule_timeout(*timeo_p); | |
103 | out: | |
104 | finish_wait(sk->sk_sleep, &wait); | |
105 | return error; | |
106 | interrupted: | |
107 | error = sock_intr_errno(*timeo_p); | |
108 | out_err: | |
109 | *err = error; | |
110 | goto out; | |
111 | out_noerr: | |
112 | *err = 0; | |
113 | error = 1; | |
114 | goto out; | |
115 | } | |
116 | ||
117 | /** | |
a59322be | 118 | * __skb_recv_datagram - Receive a datagram skbuff |
4dc3b16b PP |
119 | * @sk: socket |
120 | * @flags: MSG_ flags | |
a59322be | 121 | * @peeked: returns non-zero if this packet has been seen before |
4dc3b16b | 122 | * @err: error code returned |
1da177e4 LT |
123 | * |
124 | * Get a datagram skbuff, understands the peeking, nonblocking wakeups | |
125 | * and possible races. This replaces identical code in packet, raw and | |
126 | * udp, as well as the IPX AX.25 and Appletalk. It also finally fixes | |
127 | * the long standing peek and read race for datagram sockets. If you | |
128 | * alter this routine remember it must be re-entrant. | |
129 | * | |
130 | * This function will lock the socket if a skb is returned, so the caller | |
131 | * needs to unlock the socket in that case (usually by calling | |
132 | * skb_free_datagram) | |
133 | * | |
134 | * * It does not lock socket since today. This function is | |
135 | * * free of race conditions. This measure should/can improve | |
136 | * * significantly datagram socket latencies at high loads, | |
137 | * * when data copying to user space takes lots of time. | |
138 | * * (BTW I've just killed the last cli() in IP/IPv6/core/netlink/packet | |
139 | * * 8) Great win.) | |
140 | * * --ANK (980729) | |
141 | * | |
142 | * The order of the tests when we find no data waiting are specified | |
143 | * quite explicitly by POSIX 1003.1g, don't change them without having | |
144 | * the standard around please. | |
145 | */ | |
a59322be HX |
146 | struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, |
147 | int *peeked, int *err) | |
1da177e4 LT |
148 | { |
149 | struct sk_buff *skb; | |
150 | long timeo; | |
151 | /* | |
152 | * Caller is allowed not to check sk->sk_err before skb_recv_datagram() | |
153 | */ | |
154 | int error = sock_error(sk); | |
155 | ||
156 | if (error) | |
157 | goto no_packet; | |
158 | ||
a59322be | 159 | timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); |
1da177e4 LT |
160 | |
161 | do { | |
162 | /* Again only user level code calls this function, so nothing | |
163 | * interrupt level will suddenly eat the receive_queue. | |
164 | * | |
165 | * Look at current nfs client by the way... | |
166 | * However, this function was corrent in any case. 8) | |
167 | */ | |
a59322be HX |
168 | unsigned long cpu_flags; |
169 | ||
170 | spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags); | |
171 | skb = skb_peek(&sk->sk_receive_queue); | |
172 | if (skb) { | |
173 | *peeked = skb->peeked; | |
174 | if (flags & MSG_PEEK) { | |
175 | skb->peeked = 1; | |
1da177e4 | 176 | atomic_inc(&skb->users); |
a59322be HX |
177 | } else |
178 | __skb_unlink(skb, &sk->sk_receive_queue); | |
179 | } | |
180 | spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags); | |
1da177e4 LT |
181 | |
182 | if (skb) | |
183 | return skb; | |
184 | ||
185 | /* User doesn't want to wait */ | |
186 | error = -EAGAIN; | |
187 | if (!timeo) | |
188 | goto no_packet; | |
189 | ||
190 | } while (!wait_for_packet(sk, err, &timeo)); | |
191 | ||
192 | return NULL; | |
193 | ||
194 | no_packet: | |
195 | *err = error; | |
196 | return NULL; | |
197 | } | |
a59322be HX |
198 | EXPORT_SYMBOL(__skb_recv_datagram); |
199 | ||
200 | struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, | |
201 | int noblock, int *err) | |
202 | { | |
203 | int peeked; | |
204 | ||
205 | return __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), | |
206 | &peeked, err); | |
207 | } | |
1da177e4 LT |
208 | |
209 | void skb_free_datagram(struct sock *sk, struct sk_buff *skb) | |
210 | { | |
211 | kfree_skb(skb); | |
3ab224be | 212 | sk_mem_reclaim(sk); |
1da177e4 LT |
213 | } |
214 | ||
3305b80c HX |
215 | /** |
216 | * skb_kill_datagram - Free a datagram skbuff forcibly | |
217 | * @sk: socket | |
218 | * @skb: datagram skbuff | |
219 | * @flags: MSG_ flags | |
220 | * | |
221 | * This function frees a datagram skbuff that was received by | |
222 | * skb_recv_datagram. The flags argument must match the one | |
223 | * used for skb_recv_datagram. | |
224 | * | |
225 | * If the MSG_PEEK flag is set, and the packet is still on the | |
226 | * receive queue of the socket, it will be taken off the queue | |
227 | * before it is freed. | |
228 | * | |
229 | * This function currently only disables BH when acquiring the | |
230 | * sk_receive_queue lock. Therefore it must not be used in a | |
231 | * context where that lock is acquired in an IRQ context. | |
27ab2568 HX |
232 | * |
233 | * It returns 0 if the packet was removed by us. | |
3305b80c HX |
234 | */ |
235 | ||
27ab2568 | 236 | int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags) |
3305b80c | 237 | { |
27ab2568 HX |
238 | int err = 0; |
239 | ||
3305b80c | 240 | if (flags & MSG_PEEK) { |
27ab2568 | 241 | err = -ENOENT; |
3305b80c HX |
242 | spin_lock_bh(&sk->sk_receive_queue.lock); |
243 | if (skb == skb_peek(&sk->sk_receive_queue)) { | |
244 | __skb_unlink(skb, &sk->sk_receive_queue); | |
245 | atomic_dec(&skb->users); | |
27ab2568 | 246 | err = 0; |
3305b80c HX |
247 | } |
248 | spin_unlock_bh(&sk->sk_receive_queue.lock); | |
249 | } | |
250 | ||
251 | kfree_skb(skb); | |
3ab224be | 252 | sk_mem_reclaim(sk); |
27ab2568 | 253 | return err; |
3305b80c HX |
254 | } |
255 | ||
256 | EXPORT_SYMBOL(skb_kill_datagram); | |
257 | ||
1da177e4 LT |
258 | /** |
259 | * skb_copy_datagram_iovec - Copy a datagram to an iovec. | |
4dc3b16b PP |
260 | * @skb: buffer to copy |
261 | * @offset: offset in the buffer to start copying from | |
67be2dd1 | 262 | * @to: io vector to copy to |
4dc3b16b | 263 | * @len: amount of data to copy from buffer to iovec |
1da177e4 LT |
264 | * |
265 | * Note: the iovec is modified during the copy. | |
266 | */ | |
267 | int skb_copy_datagram_iovec(const struct sk_buff *skb, int offset, | |
268 | struct iovec *to, int len) | |
269 | { | |
1a028e50 DM |
270 | int start = skb_headlen(skb); |
271 | int i, copy = start - offset; | |
c75d721c | 272 | |
b4d9eda0 DM |
273 | /* Copy header. */ |
274 | if (copy > 0) { | |
275 | if (copy > len) | |
276 | copy = len; | |
277 | if (memcpy_toiovec(to, skb->data + offset, copy)) | |
278 | goto fault; | |
279 | if ((len -= copy) == 0) | |
280 | return 0; | |
281 | offset += copy; | |
282 | } | |
c75d721c | 283 | |
b4d9eda0 DM |
284 | /* Copy paged appendix. Hmm... why does this look so complicated? */ |
285 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { | |
1a028e50 | 286 | int end; |
1da177e4 | 287 | |
547b792c | 288 | WARN_ON(start > offset + len); |
1a028e50 DM |
289 | |
290 | end = start + skb_shinfo(skb)->frags[i].size; | |
b4d9eda0 DM |
291 | if ((copy = end - offset) > 0) { |
292 | int err; | |
293 | u8 *vaddr; | |
294 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
295 | struct page *page = frag->page; | |
1da177e4 LT |
296 | |
297 | if (copy > len) | |
298 | copy = len; | |
b4d9eda0 | 299 | vaddr = kmap(page); |
1a028e50 DM |
300 | err = memcpy_toiovec(to, vaddr + frag->page_offset + |
301 | offset - start, copy); | |
b4d9eda0 | 302 | kunmap(page); |
1da177e4 LT |
303 | if (err) |
304 | goto fault; | |
305 | if (!(len -= copy)) | |
306 | return 0; | |
307 | offset += copy; | |
308 | } | |
1a028e50 | 309 | start = end; |
1da177e4 | 310 | } |
b4d9eda0 DM |
311 | |
312 | if (skb_shinfo(skb)->frag_list) { | |
313 | struct sk_buff *list = skb_shinfo(skb)->frag_list; | |
314 | ||
315 | for (; list; list = list->next) { | |
1a028e50 DM |
316 | int end; |
317 | ||
547b792c | 318 | WARN_ON(start > offset + len); |
b4d9eda0 | 319 | |
1a028e50 | 320 | end = start + list->len; |
b4d9eda0 DM |
321 | if ((copy = end - offset) > 0) { |
322 | if (copy > len) | |
323 | copy = len; | |
1a028e50 DM |
324 | if (skb_copy_datagram_iovec(list, |
325 | offset - start, | |
326 | to, copy)) | |
b4d9eda0 DM |
327 | goto fault; |
328 | if ((len -= copy) == 0) | |
329 | return 0; | |
330 | offset += copy; | |
331 | } | |
1a028e50 | 332 | start = end; |
b4d9eda0 | 333 | } |
1da177e4 | 334 | } |
b4d9eda0 DM |
335 | if (!len) |
336 | return 0; | |
337 | ||
1da177e4 LT |
338 | fault: |
339 | return -EFAULT; | |
340 | } | |
341 | ||
db543c1f RR |
342 | /** |
343 | * skb_copy_datagram_from_iovec - Copy a datagram from an iovec. | |
344 | * @skb: buffer to copy | |
345 | * @offset: offset in the buffer to start copying to | |
346 | * @from: io vector to copy to | |
347 | * @len: amount of data to copy to buffer from iovec | |
348 | * | |
349 | * Returns 0 or -EFAULT. | |
350 | * Note: the iovec is modified during the copy. | |
351 | */ | |
352 | int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset, | |
353 | struct iovec *from, int len) | |
354 | { | |
355 | int start = skb_headlen(skb); | |
356 | int i, copy = start - offset; | |
357 | ||
358 | /* Copy header. */ | |
359 | if (copy > 0) { | |
360 | if (copy > len) | |
361 | copy = len; | |
362 | if (memcpy_fromiovec(skb->data + offset, from, copy)) | |
363 | goto fault; | |
364 | if ((len -= copy) == 0) | |
365 | return 0; | |
366 | offset += copy; | |
367 | } | |
368 | ||
369 | /* Copy paged appendix. Hmm... why does this look so complicated? */ | |
370 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { | |
371 | int end; | |
372 | ||
373 | WARN_ON(start > offset + len); | |
374 | ||
375 | end = start + skb_shinfo(skb)->frags[i].size; | |
376 | if ((copy = end - offset) > 0) { | |
377 | int err; | |
378 | u8 *vaddr; | |
379 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
380 | struct page *page = frag->page; | |
381 | ||
382 | if (copy > len) | |
383 | copy = len; | |
384 | vaddr = kmap(page); | |
385 | err = memcpy_fromiovec(vaddr + frag->page_offset + | |
386 | offset - start, from, copy); | |
387 | kunmap(page); | |
388 | if (err) | |
389 | goto fault; | |
390 | ||
391 | if (!(len -= copy)) | |
392 | return 0; | |
393 | offset += copy; | |
394 | } | |
395 | start = end; | |
396 | } | |
397 | ||
398 | if (skb_shinfo(skb)->frag_list) { | |
399 | struct sk_buff *list = skb_shinfo(skb)->frag_list; | |
400 | ||
401 | for (; list; list = list->next) { | |
402 | int end; | |
403 | ||
404 | WARN_ON(start > offset + len); | |
405 | ||
406 | end = start + list->len; | |
407 | if ((copy = end - offset) > 0) { | |
408 | if (copy > len) | |
409 | copy = len; | |
410 | if (skb_copy_datagram_from_iovec(list, | |
411 | offset - start, | |
412 | from, copy)) | |
413 | goto fault; | |
414 | if ((len -= copy) == 0) | |
415 | return 0; | |
416 | offset += copy; | |
417 | } | |
418 | start = end; | |
419 | } | |
420 | } | |
421 | if (!len) | |
422 | return 0; | |
423 | ||
424 | fault: | |
425 | return -EFAULT; | |
426 | } | |
427 | EXPORT_SYMBOL(skb_copy_datagram_from_iovec); | |
428 | ||
1da177e4 LT |
429 | static int skb_copy_and_csum_datagram(const struct sk_buff *skb, int offset, |
430 | u8 __user *to, int len, | |
5084205f | 431 | __wsum *csump) |
1da177e4 | 432 | { |
1a028e50 | 433 | int start = skb_headlen(skb); |
1da177e4 | 434 | int pos = 0; |
1a028e50 | 435 | int i, copy = start - offset; |
1da177e4 LT |
436 | |
437 | /* Copy header. */ | |
438 | if (copy > 0) { | |
439 | int err = 0; | |
440 | if (copy > len) | |
441 | copy = len; | |
442 | *csump = csum_and_copy_to_user(skb->data + offset, to, copy, | |
443 | *csump, &err); | |
444 | if (err) | |
445 | goto fault; | |
446 | if ((len -= copy) == 0) | |
447 | return 0; | |
448 | offset += copy; | |
449 | to += copy; | |
450 | pos = copy; | |
451 | } | |
452 | ||
453 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { | |
1a028e50 | 454 | int end; |
1da177e4 | 455 | |
547b792c | 456 | WARN_ON(start > offset + len); |
1a028e50 DM |
457 | |
458 | end = start + skb_shinfo(skb)->frags[i].size; | |
1da177e4 | 459 | if ((copy = end - offset) > 0) { |
5084205f | 460 | __wsum csum2; |
1da177e4 LT |
461 | int err = 0; |
462 | u8 *vaddr; | |
463 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
464 | struct page *page = frag->page; | |
465 | ||
466 | if (copy > len) | |
467 | copy = len; | |
468 | vaddr = kmap(page); | |
469 | csum2 = csum_and_copy_to_user(vaddr + | |
1a028e50 DM |
470 | frag->page_offset + |
471 | offset - start, | |
1da177e4 LT |
472 | to, copy, 0, &err); |
473 | kunmap(page); | |
474 | if (err) | |
475 | goto fault; | |
476 | *csump = csum_block_add(*csump, csum2, pos); | |
477 | if (!(len -= copy)) | |
478 | return 0; | |
479 | offset += copy; | |
480 | to += copy; | |
481 | pos += copy; | |
482 | } | |
1a028e50 | 483 | start = end; |
1da177e4 LT |
484 | } |
485 | ||
486 | if (skb_shinfo(skb)->frag_list) { | |
487 | struct sk_buff *list = skb_shinfo(skb)->frag_list; | |
488 | ||
489 | for (; list; list=list->next) { | |
1a028e50 DM |
490 | int end; |
491 | ||
547b792c | 492 | WARN_ON(start > offset + len); |
1da177e4 | 493 | |
1a028e50 | 494 | end = start + list->len; |
1da177e4 | 495 | if ((copy = end - offset) > 0) { |
5084205f | 496 | __wsum csum2 = 0; |
1da177e4 LT |
497 | if (copy > len) |
498 | copy = len; | |
1a028e50 DM |
499 | if (skb_copy_and_csum_datagram(list, |
500 | offset - start, | |
1da177e4 LT |
501 | to, copy, |
502 | &csum2)) | |
503 | goto fault; | |
504 | *csump = csum_block_add(*csump, csum2, pos); | |
505 | if ((len -= copy) == 0) | |
506 | return 0; | |
507 | offset += copy; | |
508 | to += copy; | |
509 | pos += copy; | |
510 | } | |
1a028e50 | 511 | start = end; |
1da177e4 LT |
512 | } |
513 | } | |
514 | if (!len) | |
515 | return 0; | |
516 | ||
517 | fault: | |
518 | return -EFAULT; | |
519 | } | |
520 | ||
759e5d00 | 521 | __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len) |
fb286bb2 | 522 | { |
d3bc23e7 | 523 | __sum16 sum; |
fb286bb2 | 524 | |
759e5d00 | 525 | sum = csum_fold(skb_checksum(skb, 0, len, skb->csum)); |
fb286bb2 | 526 | if (likely(!sum)) { |
84fa7933 | 527 | if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) |
fb286bb2 HX |
528 | netdev_rx_csum_fault(skb->dev); |
529 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
530 | } | |
531 | return sum; | |
532 | } | |
759e5d00 HX |
533 | EXPORT_SYMBOL(__skb_checksum_complete_head); |
534 | ||
535 | __sum16 __skb_checksum_complete(struct sk_buff *skb) | |
536 | { | |
537 | return __skb_checksum_complete_head(skb, skb->len); | |
538 | } | |
fb286bb2 HX |
539 | EXPORT_SYMBOL(__skb_checksum_complete); |
540 | ||
1da177e4 LT |
541 | /** |
542 | * skb_copy_and_csum_datagram_iovec - Copy and checkum skb to user iovec. | |
4dc3b16b PP |
543 | * @skb: skbuff |
544 | * @hlen: hardware length | |
67be2dd1 | 545 | * @iov: io vector |
4ec93edb | 546 | * |
1da177e4 LT |
547 | * Caller _must_ check that skb will fit to this iovec. |
548 | * | |
549 | * Returns: 0 - success. | |
550 | * -EINVAL - checksum failure. | |
551 | * -EFAULT - fault during copy. Beware, in this case iovec | |
552 | * can be modified! | |
553 | */ | |
fb286bb2 | 554 | int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, |
1da177e4 LT |
555 | int hlen, struct iovec *iov) |
556 | { | |
d3bc23e7 | 557 | __wsum csum; |
1da177e4 LT |
558 | int chunk = skb->len - hlen; |
559 | ||
ef8aef55 HX |
560 | if (!chunk) |
561 | return 0; | |
562 | ||
1da177e4 LT |
563 | /* Skip filled elements. |
564 | * Pretty silly, look at memcpy_toiovec, though 8) | |
565 | */ | |
566 | while (!iov->iov_len) | |
567 | iov++; | |
568 | ||
569 | if (iov->iov_len < chunk) { | |
fb286bb2 | 570 | if (__skb_checksum_complete(skb)) |
1da177e4 LT |
571 | goto csum_error; |
572 | if (skb_copy_datagram_iovec(skb, hlen, iov, chunk)) | |
573 | goto fault; | |
574 | } else { | |
575 | csum = csum_partial(skb->data, hlen, skb->csum); | |
576 | if (skb_copy_and_csum_datagram(skb, hlen, iov->iov_base, | |
577 | chunk, &csum)) | |
578 | goto fault; | |
d3bc23e7 | 579 | if (csum_fold(csum)) |
1da177e4 | 580 | goto csum_error; |
84fa7933 | 581 | if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) |
fb286bb2 | 582 | netdev_rx_csum_fault(skb->dev); |
1da177e4 LT |
583 | iov->iov_len -= chunk; |
584 | iov->iov_base += chunk; | |
585 | } | |
586 | return 0; | |
587 | csum_error: | |
588 | return -EINVAL; | |
589 | fault: | |
590 | return -EFAULT; | |
591 | } | |
592 | ||
593 | /** | |
594 | * datagram_poll - generic datagram poll | |
4dc3b16b PP |
595 | * @file: file struct |
596 | * @sock: socket | |
597 | * @wait: poll table | |
1da177e4 LT |
598 | * |
599 | * Datagram poll: Again totally generic. This also handles | |
600 | * sequenced packet sockets providing the socket receive queue | |
601 | * is only ever holding data ready to receive. | |
602 | * | |
603 | * Note: when you _don't_ use this routine for this protocol, | |
604 | * and you use a different write policy from sock_writeable() | |
605 | * then please supply your own write_space callback. | |
606 | */ | |
607 | unsigned int datagram_poll(struct file *file, struct socket *sock, | |
608 | poll_table *wait) | |
609 | { | |
610 | struct sock *sk = sock->sk; | |
611 | unsigned int mask; | |
612 | ||
613 | poll_wait(file, sk->sk_sleep, wait); | |
614 | mask = 0; | |
615 | ||
616 | /* exceptional events? */ | |
617 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) | |
618 | mask |= POLLERR; | |
f348d70a DL |
619 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
620 | mask |= POLLRDHUP; | |
1da177e4 LT |
621 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
622 | mask |= POLLHUP; | |
623 | ||
624 | /* readable? */ | |
625 | if (!skb_queue_empty(&sk->sk_receive_queue) || | |
626 | (sk->sk_shutdown & RCV_SHUTDOWN)) | |
627 | mask |= POLLIN | POLLRDNORM; | |
628 | ||
629 | /* Connection-based need to check for termination and startup */ | |
630 | if (connection_based(sk)) { | |
631 | if (sk->sk_state == TCP_CLOSE) | |
632 | mask |= POLLHUP; | |
633 | /* connection hasn't started yet? */ | |
634 | if (sk->sk_state == TCP_SYN_SENT) | |
635 | return mask; | |
636 | } | |
637 | ||
638 | /* writable? */ | |
639 | if (sock_writeable(sk)) | |
640 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
641 | else | |
642 | set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
643 | ||
644 | return mask; | |
645 | } | |
646 | ||
647 | EXPORT_SYMBOL(datagram_poll); | |
648 | EXPORT_SYMBOL(skb_copy_and_csum_datagram_iovec); | |
649 | EXPORT_SYMBOL(skb_copy_datagram_iovec); | |
650 | EXPORT_SYMBOL(skb_free_datagram); | |
651 | EXPORT_SYMBOL(skb_recv_datagram); |