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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 | * |
12 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>. (datagram_poll() from old |
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> |
46 | #include <linux/netdevice.h> |
47 | #include <linux/rtnetlink.h> |
48 | #include <linux/poll.h> |
49 | #include <linux/highmem.h> |
50 | #include <linux/spinlock.h> |
51 | |
52 | #include <net/protocol.h> |
53 | #include <linux/skbuff.h> |
54 | |
55 | #include <net/checksum.h> |
56 | #include <net/sock.h> |
57 | #include <net/tcp_states.h> |
58 | #include <trace/events/skb.h> |
59 | |
60 | /* |
61 | * Is a socket 'connection oriented' ? |
62 | */ |
63 | static inline int connection_based(struct sock *sk) |
64 | { |
65 | return sk->sk_type == SOCK_SEQPACKET || sk->sk_type == SOCK_STREAM; |
66 | } |
67 | |
68 | static int receiver_wake_function(wait_queue_t *wait, unsigned mode, int sync, |
69 | void *key) |
70 | { |
71 | unsigned long bits = (unsigned long)key; |
72 | |
73 | /* |
74 | * Avoid a wakeup if event not interesting for us |
75 | */ |
76 | if (bits && !(bits & (POLLIN | POLLERR))) |
77 | return 0; |
78 | return autoremove_wake_function(wait, mode, sync, key); |
79 | } |
80 | /* |
81 | * Wait for a packet.. |
82 | */ |
83 | static int wait_for_packet(struct sock *sk, int *err, long *timeo_p) |
84 | { |
85 | int error; |
86 | DEFINE_WAIT_FUNC(wait, receiver_wake_function); |
87 | |
88 | prepare_to_wait_exclusive(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); |
89 | |
90 | /* Socket errors? */ |
91 | error = sock_error(sk); |
92 | if (error) |
93 | goto out_err; |
94 | |
95 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
96 | goto out; |
97 | |
98 | /* Socket shut down? */ |
99 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
100 | goto out_noerr; |
101 | |
102 | /* Sequenced packets can come disconnected. |
103 | * If so we report the problem |
104 | */ |
105 | error = -ENOTCONN; |
106 | if (connection_based(sk) && |
107 | !(sk->sk_state == TCP_ESTABLISHED || sk->sk_state == TCP_LISTEN)) |
108 | goto out_err; |
109 | |
110 | /* handle signals */ |
111 | if (signal_pending(current)) |
112 | goto interrupted; |
113 | |
114 | error = 0; |
115 | *timeo_p = schedule_timeout(*timeo_p); |
116 | out: |
117 | finish_wait(sk->sk_sleep, &wait); |
118 | return error; |
119 | interrupted: |
120 | error = sock_intr_errno(*timeo_p); |
121 | out_err: |
122 | *err = error; |
123 | goto out; |
124 | out_noerr: |
125 | *err = 0; |
126 | error = 1; |
127 | goto out; |
128 | } |
129 | |
130 | /** |
131 | * __skb_recv_datagram - Receive a datagram skbuff |
132 | * @sk: socket |
133 | * @flags: MSG_ flags |
134 | * @peeked: returns non-zero if this packet has been seen before |
135 | * @err: error code returned |
136 | * |
137 | * Get a datagram skbuff, understands the peeking, nonblocking wakeups |
138 | * and possible races. This replaces identical code in packet, raw and |
139 | * udp, as well as the IPX AX.25 and Appletalk. It also finally fixes |
140 | * the long standing peek and read race for datagram sockets. If you |
141 | * alter this routine remember it must be re-entrant. |
142 | * |
143 | * This function will lock the socket if a skb is returned, so the caller |
144 | * needs to unlock the socket in that case (usually by calling |
145 | * skb_free_datagram) |
146 | * |
147 | * * It does not lock socket since today. This function is |
148 | * * free of race conditions. This measure should/can improve |
149 | * * significantly datagram socket latencies at high loads, |
150 | * * when data copying to user space takes lots of time. |
151 | * * (BTW I've just killed the last cli() in IP/IPv6/core/netlink/packet |
152 | * * 8) Great win.) |
153 | * * --ANK (980729) |
154 | * |
155 | * The order of the tests when we find no data waiting are specified |
156 | * quite explicitly by POSIX 1003.1g, don't change them without having |
157 | * the standard around please. |
158 | */ |
159 | struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, |
160 | int *peeked, int *err) |
161 | { |
162 | struct sk_buff *skb; |
163 | long timeo; |
164 | /* |
165 | * Caller is allowed not to check sk->sk_err before skb_recv_datagram() |
166 | */ |
167 | int error = sock_error(sk); |
168 | |
169 | if (error) |
170 | goto no_packet; |
171 | |
172 | timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); |
173 | |
174 | do { |
175 | /* Again only user level code calls this function, so nothing |
176 | * interrupt level will suddenly eat the receive_queue. |
177 | * |
178 | * Look at current nfs client by the way... |
179 | * However, this function was corrent in any case. 8) |
180 | */ |
181 | unsigned long cpu_flags; |
182 | |
183 | spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags); |
184 | skb = skb_peek(&sk->sk_receive_queue); |
185 | if (skb) { |
186 | *peeked = skb->peeked; |
187 | if (flags & MSG_PEEK) { |
188 | skb->peeked = 1; |
189 | atomic_inc(&skb->users); |
190 | } else |
191 | __skb_unlink(skb, &sk->sk_receive_queue); |
192 | } |
193 | spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags); |
194 | |
195 | if (skb) |
196 | return skb; |
197 | |
198 | /* User doesn't want to wait */ |
199 | error = -EAGAIN; |
200 | if (!timeo) |
201 | goto no_packet; |
202 | |
203 | } while (!wait_for_packet(sk, err, &timeo)); |
204 | |
205 | return NULL; |
206 | |
207 | no_packet: |
208 | *err = error; |
209 | return NULL; |
210 | } |
211 | EXPORT_SYMBOL(__skb_recv_datagram); |
212 | |
213 | struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, |
214 | int noblock, int *err) |
215 | { |
216 | int peeked; |
217 | |
218 | return __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), |
219 | &peeked, err); |
220 | } |
221 | |
222 | void skb_free_datagram(struct sock *sk, struct sk_buff *skb) |
223 | { |
224 | consume_skb(skb); |
225 | sk_mem_reclaim_partial(sk); |
226 | } |
227 | EXPORT_SYMBOL(skb_free_datagram); |
228 | |
229 | void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb) |
230 | { |
231 | lock_sock(sk); |
232 | skb_free_datagram(sk, skb); |
233 | release_sock(sk); |
234 | } |
235 | EXPORT_SYMBOL(skb_free_datagram_locked); |
236 | |
237 | /** |
238 | * skb_kill_datagram - Free a datagram skbuff forcibly |
239 | * @sk: socket |
240 | * @skb: datagram skbuff |
241 | * @flags: MSG_ flags |
242 | * |
243 | * This function frees a datagram skbuff that was received by |
244 | * skb_recv_datagram. The flags argument must match the one |
245 | * used for skb_recv_datagram. |
246 | * |
247 | * If the MSG_PEEK flag is set, and the packet is still on the |
248 | * receive queue of the socket, it will be taken off the queue |
249 | * before it is freed. |
250 | * |
251 | * This function currently only disables BH when acquiring the |
252 | * sk_receive_queue lock. Therefore it must not be used in a |
253 | * context where that lock is acquired in an IRQ context. |
254 | * |
255 | * It returns 0 if the packet was removed by us. |
256 | */ |
257 | |
258 | int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags) |
259 | { |
260 | int err = 0; |
261 | |
262 | if (flags & MSG_PEEK) { |
263 | err = -ENOENT; |
264 | spin_lock_bh(&sk->sk_receive_queue.lock); |
265 | if (skb == skb_peek(&sk->sk_receive_queue)) { |
266 | __skb_unlink(skb, &sk->sk_receive_queue); |
267 | atomic_dec(&skb->users); |
268 | err = 0; |
269 | } |
270 | spin_unlock_bh(&sk->sk_receive_queue.lock); |
271 | } |
272 | |
273 | kfree_skb(skb); |
274 | sk_mem_reclaim_partial(sk); |
275 | |
276 | return err; |
277 | } |
278 | |
279 | EXPORT_SYMBOL(skb_kill_datagram); |
280 | |
281 | /** |
282 | * skb_copy_datagram_iovec - Copy a datagram to an iovec. |
283 | * @skb: buffer to copy |
284 | * @offset: offset in the buffer to start copying from |
285 | * @to: io vector to copy to |
286 | * @len: amount of data to copy from buffer to iovec |
287 | * |
288 | * Note: the iovec is modified during the copy. |
289 | */ |
290 | int skb_copy_datagram_iovec(const struct sk_buff *skb, int offset, |
291 | struct iovec *to, int len) |
292 | { |
293 | int start = skb_headlen(skb); |
294 | int i, copy = start - offset; |
295 | struct sk_buff *frag_iter; |
296 | |
297 | trace_skb_copy_datagram_iovec(skb, len); |
298 | |
299 | /* Copy header. */ |
300 | if (copy > 0) { |
301 | if (copy > len) |
302 | copy = len; |
303 | if (memcpy_toiovec(to, skb->data + offset, copy)) |
304 | goto fault; |
305 | if ((len -= copy) == 0) |
306 | return 0; |
307 | offset += copy; |
308 | } |
309 | |
310 | /* Copy paged appendix. Hmm... why does this look so complicated? */ |
311 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
312 | int end; |
313 | |
314 | WARN_ON(start > offset + len); |
315 | |
316 | end = start + skb_shinfo(skb)->frags[i].size; |
317 | if ((copy = end - offset) > 0) { |
318 | int err; |
319 | u8 *vaddr; |
320 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
321 | struct page *page = frag->page; |
322 | |
323 | if (copy > len) |
324 | copy = len; |
325 | vaddr = kmap(page); |
326 | err = memcpy_toiovec(to, vaddr + frag->page_offset + |
327 | offset - start, copy); |
328 | kunmap(page); |
329 | if (err) |
330 | goto fault; |
331 | if (!(len -= copy)) |
332 | return 0; |
333 | offset += copy; |
334 | } |
335 | start = end; |
336 | } |
337 | |
338 | skb_walk_frags(skb, frag_iter) { |
339 | int end; |
340 | |
341 | WARN_ON(start > offset + len); |
342 | |
343 | end = start + frag_iter->len; |
344 | if ((copy = end - offset) > 0) { |
345 | if (copy > len) |
346 | copy = len; |
347 | if (skb_copy_datagram_iovec(frag_iter, |
348 | offset - start, |
349 | to, copy)) |
350 | goto fault; |
351 | if ((len -= copy) == 0) |
352 | return 0; |
353 | offset += copy; |
354 | } |
355 | start = end; |
356 | } |
357 | if (!len) |
358 | return 0; |
359 | |
360 | fault: |
361 | return -EFAULT; |
362 | } |
363 | |
364 | /** |
365 | * skb_copy_datagram_const_iovec - Copy a datagram to an iovec. |
366 | * @skb: buffer to copy |
367 | * @offset: offset in the buffer to start copying from |
368 | * @to: io vector to copy to |
369 | * @to_offset: offset in the io vector to start copying to |
370 | * @len: amount of data to copy from buffer to iovec |
371 | * |
372 | * Returns 0 or -EFAULT. |
373 | * Note: the iovec is not modified during the copy. |
374 | */ |
375 | int skb_copy_datagram_const_iovec(const struct sk_buff *skb, int offset, |
376 | const struct iovec *to, int to_offset, |
377 | int len) |
378 | { |
379 | int start = skb_headlen(skb); |
380 | int i, copy = start - offset; |
381 | struct sk_buff *frag_iter; |
382 | |
383 | /* Copy header. */ |
384 | if (copy > 0) { |
385 | if (copy > len) |
386 | copy = len; |
387 | if (memcpy_toiovecend(to, skb->data + offset, to_offset, copy)) |
388 | goto fault; |
389 | if ((len -= copy) == 0) |
390 | return 0; |
391 | offset += copy; |
392 | to_offset += copy; |
393 | } |
394 | |
395 | /* Copy paged appendix. Hmm... why does this look so complicated? */ |
396 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
397 | int end; |
398 | |
399 | WARN_ON(start > offset + len); |
400 | |
401 | end = start + skb_shinfo(skb)->frags[i].size; |
402 | if ((copy = end - offset) > 0) { |
403 | int err; |
404 | u8 *vaddr; |
405 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
406 | struct page *page = frag->page; |
407 | |
408 | if (copy > len) |
409 | copy = len; |
410 | vaddr = kmap(page); |
411 | err = memcpy_toiovecend(to, vaddr + frag->page_offset + |
412 | offset - start, to_offset, copy); |
413 | kunmap(page); |
414 | if (err) |
415 | goto fault; |
416 | if (!(len -= copy)) |
417 | return 0; |
418 | offset += copy; |
419 | to_offset += copy; |
420 | } |
421 | start = end; |
422 | } |
423 | |
424 | skb_walk_frags(skb, frag_iter) { |
425 | int end; |
426 | |
427 | WARN_ON(start > offset + len); |
428 | |
429 | end = start + frag_iter->len; |
430 | if ((copy = end - offset) > 0) { |
431 | if (copy > len) |
432 | copy = len; |
433 | if (skb_copy_datagram_const_iovec(frag_iter, |
434 | offset - start, |
435 | to, to_offset, |
436 | copy)) |
437 | goto fault; |
438 | if ((len -= copy) == 0) |
439 | return 0; |
440 | offset += copy; |
441 | to_offset += copy; |
442 | } |
443 | start = end; |
444 | } |
445 | if (!len) |
446 | return 0; |
447 | |
448 | fault: |
449 | return -EFAULT; |
450 | } |
451 | EXPORT_SYMBOL(skb_copy_datagram_const_iovec); |
452 | |
453 | /** |
454 | * skb_copy_datagram_from_iovec - Copy a datagram from an iovec. |
455 | * @skb: buffer to copy |
456 | * @offset: offset in the buffer to start copying to |
457 | * @from: io vector to copy to |
458 | * @from_offset: offset in the io vector to start copying from |
459 | * @len: amount of data to copy to buffer from iovec |
460 | * |
461 | * Returns 0 or -EFAULT. |
462 | * Note: the iovec is not modified during the copy. |
463 | */ |
464 | int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset, |
465 | const struct iovec *from, int from_offset, |
466 | int len) |
467 | { |
468 | int start = skb_headlen(skb); |
469 | int i, copy = start - offset; |
470 | struct sk_buff *frag_iter; |
471 | |
472 | /* Copy header. */ |
473 | if (copy > 0) { |
474 | if (copy > len) |
475 | copy = len; |
476 | if (memcpy_fromiovecend(skb->data + offset, from, from_offset, |
477 | copy)) |
478 | goto fault; |
479 | if ((len -= copy) == 0) |
480 | return 0; |
481 | offset += copy; |
482 | from_offset += copy; |
483 | } |
484 | |
485 | /* Copy paged appendix. Hmm... why does this look so complicated? */ |
486 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
487 | int end; |
488 | |
489 | WARN_ON(start > offset + len); |
490 | |
491 | end = start + skb_shinfo(skb)->frags[i].size; |
492 | if ((copy = end - offset) > 0) { |
493 | int err; |
494 | u8 *vaddr; |
495 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
496 | struct page *page = frag->page; |
497 | |
498 | if (copy > len) |
499 | copy = len; |
500 | vaddr = kmap(page); |
501 | err = memcpy_fromiovecend(vaddr + frag->page_offset + |
502 | offset - start, |
503 | from, from_offset, copy); |
504 | kunmap(page); |
505 | if (err) |
506 | goto fault; |
507 | |
508 | if (!(len -= copy)) |
509 | return 0; |
510 | offset += copy; |
511 | from_offset += copy; |
512 | } |
513 | start = end; |
514 | } |
515 | |
516 | skb_walk_frags(skb, frag_iter) { |
517 | int end; |
518 | |
519 | WARN_ON(start > offset + len); |
520 | |
521 | end = start + frag_iter->len; |
522 | if ((copy = end - offset) > 0) { |
523 | if (copy > len) |
524 | copy = len; |
525 | if (skb_copy_datagram_from_iovec(frag_iter, |
526 | offset - start, |
527 | from, |
528 | from_offset, |
529 | copy)) |
530 | goto fault; |
531 | if ((len -= copy) == 0) |
532 | return 0; |
533 | offset += copy; |
534 | from_offset += copy; |
535 | } |
536 | start = end; |
537 | } |
538 | if (!len) |
539 | return 0; |
540 | |
541 | fault: |
542 | return -EFAULT; |
543 | } |
544 | EXPORT_SYMBOL(skb_copy_datagram_from_iovec); |
545 | |
546 | static int skb_copy_and_csum_datagram(const struct sk_buff *skb, int offset, |
547 | u8 __user *to, int len, |
548 | __wsum *csump) |
549 | { |
550 | int start = skb_headlen(skb); |
551 | int i, copy = start - offset; |
552 | struct sk_buff *frag_iter; |
553 | int pos = 0; |
554 | |
555 | /* Copy header. */ |
556 | if (copy > 0) { |
557 | int err = 0; |
558 | if (copy > len) |
559 | copy = len; |
560 | *csump = csum_and_copy_to_user(skb->data + offset, to, copy, |
561 | *csump, &err); |
562 | if (err) |
563 | goto fault; |
564 | if ((len -= copy) == 0) |
565 | return 0; |
566 | offset += copy; |
567 | to += copy; |
568 | pos = copy; |
569 | } |
570 | |
571 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
572 | int end; |
573 | |
574 | WARN_ON(start > offset + len); |
575 | |
576 | end = start + skb_shinfo(skb)->frags[i].size; |
577 | if ((copy = end - offset) > 0) { |
578 | __wsum csum2; |
579 | int err = 0; |
580 | u8 *vaddr; |
581 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
582 | struct page *page = frag->page; |
583 | |
584 | if (copy > len) |
585 | copy = len; |
586 | vaddr = kmap(page); |
587 | csum2 = csum_and_copy_to_user(vaddr + |
588 | frag->page_offset + |
589 | offset - start, |
590 | to, copy, 0, &err); |
591 | kunmap(page); |
592 | if (err) |
593 | goto fault; |
594 | *csump = csum_block_add(*csump, csum2, pos); |
595 | if (!(len -= copy)) |
596 | return 0; |
597 | offset += copy; |
598 | to += copy; |
599 | pos += copy; |
600 | } |
601 | start = end; |
602 | } |
603 | |
604 | skb_walk_frags(skb, frag_iter) { |
605 | int end; |
606 | |
607 | WARN_ON(start > offset + len); |
608 | |
609 | end = start + frag_iter->len; |
610 | if ((copy = end - offset) > 0) { |
611 | __wsum csum2 = 0; |
612 | if (copy > len) |
613 | copy = len; |
614 | if (skb_copy_and_csum_datagram(frag_iter, |
615 | offset - start, |
616 | to, copy, |
617 | &csum2)) |
618 | goto fault; |
619 | *csump = csum_block_add(*csump, csum2, pos); |
620 | if ((len -= copy) == 0) |
621 | return 0; |
622 | offset += copy; |
623 | to += copy; |
624 | pos += copy; |
625 | } |
626 | start = end; |
627 | } |
628 | if (!len) |
629 | return 0; |
630 | |
631 | fault: |
632 | return -EFAULT; |
633 | } |
634 | |
635 | __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len) |
636 | { |
637 | __sum16 sum; |
638 | |
639 | sum = csum_fold(skb_checksum(skb, 0, len, skb->csum)); |
640 | if (likely(!sum)) { |
641 | if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) |
642 | netdev_rx_csum_fault(skb->dev); |
643 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
644 | } |
645 | return sum; |
646 | } |
647 | EXPORT_SYMBOL(__skb_checksum_complete_head); |
648 | |
649 | __sum16 __skb_checksum_complete(struct sk_buff *skb) |
650 | { |
651 | return __skb_checksum_complete_head(skb, skb->len); |
652 | } |
653 | EXPORT_SYMBOL(__skb_checksum_complete); |
654 | |
655 | /** |
656 | * skb_copy_and_csum_datagram_iovec - Copy and checkum skb to user iovec. |
657 | * @skb: skbuff |
658 | * @hlen: hardware length |
659 | * @iov: io vector |
660 | * |
661 | * Caller _must_ check that skb will fit to this iovec. |
662 | * |
663 | * Returns: 0 - success. |
664 | * -EINVAL - checksum failure. |
665 | * -EFAULT - fault during copy. Beware, in this case iovec |
666 | * can be modified! |
667 | */ |
668 | int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, |
669 | int hlen, struct iovec *iov) |
670 | { |
671 | __wsum csum; |
672 | int chunk = skb->len - hlen; |
673 | |
674 | if (!chunk) |
675 | return 0; |
676 | |
677 | /* Skip filled elements. |
678 | * Pretty silly, look at memcpy_toiovec, though 8) |
679 | */ |
680 | while (!iov->iov_len) |
681 | iov++; |
682 | |
683 | if (iov->iov_len < chunk) { |
684 | if (__skb_checksum_complete(skb)) |
685 | goto csum_error; |
686 | if (skb_copy_datagram_iovec(skb, hlen, iov, chunk)) |
687 | goto fault; |
688 | } else { |
689 | csum = csum_partial(skb->data, hlen, skb->csum); |
690 | if (skb_copy_and_csum_datagram(skb, hlen, iov->iov_base, |
691 | chunk, &csum)) |
692 | goto fault; |
693 | if (csum_fold(csum)) |
694 | goto csum_error; |
695 | if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) |
696 | netdev_rx_csum_fault(skb->dev); |
697 | iov->iov_len -= chunk; |
698 | iov->iov_base += chunk; |
699 | } |
700 | return 0; |
701 | csum_error: |
702 | return -EINVAL; |
703 | fault: |
704 | return -EFAULT; |
705 | } |
706 | |
707 | /** |
708 | * datagram_poll - generic datagram poll |
709 | * @file: file struct |
710 | * @sock: socket |
711 | * @wait: poll table |
712 | * |
713 | * Datagram poll: Again totally generic. This also handles |
714 | * sequenced packet sockets providing the socket receive queue |
715 | * is only ever holding data ready to receive. |
716 | * |
717 | * Note: when you _don't_ use this routine for this protocol, |
718 | * and you use a different write policy from sock_writeable() |
719 | * then please supply your own write_space callback. |
720 | */ |
721 | unsigned int datagram_poll(struct file *file, struct socket *sock, |
722 | poll_table *wait) |
723 | { |
724 | struct sock *sk = sock->sk; |
725 | unsigned int mask; |
726 | |
727 | sock_poll_wait(file, sk->sk_sleep, wait); |
728 | mask = 0; |
729 | |
730 | /* exceptional events? */ |
731 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) |
732 | mask |= POLLERR; |
733 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
734 | mask |= POLLRDHUP; |
735 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
736 | mask |= POLLHUP; |
737 | |
738 | /* readable? */ |
739 | if (!skb_queue_empty(&sk->sk_receive_queue) || |
740 | (sk->sk_shutdown & RCV_SHUTDOWN)) |
741 | mask |= POLLIN | POLLRDNORM; |
742 | |
743 | /* Connection-based need to check for termination and startup */ |
744 | if (connection_based(sk)) { |
745 | if (sk->sk_state == TCP_CLOSE) |
746 | mask |= POLLHUP; |
747 | /* connection hasn't started yet? */ |
748 | if (sk->sk_state == TCP_SYN_SENT) |
749 | return mask; |
750 | } |
751 | |
752 | /* writable? */ |
753 | if (sock_writeable(sk)) |
754 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; |
755 | else |
756 | set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); |
757 | |
758 | return mask; |
759 | } |
760 | |
761 | EXPORT_SYMBOL(datagram_poll); |
762 | EXPORT_SYMBOL(skb_copy_and_csum_datagram_iovec); |
763 | EXPORT_SYMBOL(skb_copy_datagram_iovec); |
764 | EXPORT_SYMBOL(skb_recv_datagram); |
765 |
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