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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> |
5a0e3ad6 | 51 | #include <linux/slab.h> |
1da177e4 LT |
52 | |
53 | #include <net/protocol.h> | |
54 | #include <linux/skbuff.h> | |
1da177e4 | 55 | |
c752f073 ACM |
56 | #include <net/checksum.h> |
57 | #include <net/sock.h> | |
58 | #include <net/tcp_states.h> | |
e9b3cc1b | 59 | #include <trace/events/skb.h> |
1da177e4 LT |
60 | |
61 | /* | |
62 | * Is a socket 'connection oriented' ? | |
63 | */ | |
64 | static inline int connection_based(struct sock *sk) | |
65 | { | |
66 | return sk->sk_type == SOCK_SEQPACKET || sk->sk_type == SOCK_STREAM; | |
67 | } | |
68 | ||
bf368e4e ED |
69 | static int receiver_wake_function(wait_queue_t *wait, unsigned mode, int sync, |
70 | void *key) | |
71 | { | |
72 | unsigned long bits = (unsigned long)key; | |
73 | ||
74 | /* | |
75 | * Avoid a wakeup if event not interesting for us | |
76 | */ | |
77 | if (bits && !(bits & (POLLIN | POLLERR))) | |
78 | return 0; | |
79 | return autoremove_wake_function(wait, mode, sync, key); | |
80 | } | |
1da177e4 LT |
81 | /* |
82 | * Wait for a packet.. | |
83 | */ | |
84 | static int wait_for_packet(struct sock *sk, int *err, long *timeo_p) | |
85 | { | |
86 | int error; | |
bf368e4e | 87 | DEFINE_WAIT_FUNC(wait, receiver_wake_function); |
1da177e4 | 88 | |
aa395145 | 89 | prepare_to_wait_exclusive(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); |
1da177e4 LT |
90 | |
91 | /* Socket errors? */ | |
92 | error = sock_error(sk); | |
93 | if (error) | |
94 | goto out_err; | |
95 | ||
96 | if (!skb_queue_empty(&sk->sk_receive_queue)) | |
97 | goto out; | |
98 | ||
99 | /* Socket shut down? */ | |
100 | if (sk->sk_shutdown & RCV_SHUTDOWN) | |
101 | goto out_noerr; | |
102 | ||
103 | /* Sequenced packets can come disconnected. | |
104 | * If so we report the problem | |
105 | */ | |
106 | error = -ENOTCONN; | |
107 | if (connection_based(sk) && | |
108 | !(sk->sk_state == TCP_ESTABLISHED || sk->sk_state == TCP_LISTEN)) | |
109 | goto out_err; | |
110 | ||
111 | /* handle signals */ | |
112 | if (signal_pending(current)) | |
113 | goto interrupted; | |
114 | ||
115 | error = 0; | |
116 | *timeo_p = schedule_timeout(*timeo_p); | |
117 | out: | |
aa395145 | 118 | finish_wait(sk_sleep(sk), &wait); |
1da177e4 LT |
119 | return error; |
120 | interrupted: | |
121 | error = sock_intr_errno(*timeo_p); | |
122 | out_err: | |
123 | *err = error; | |
124 | goto out; | |
125 | out_noerr: | |
126 | *err = 0; | |
127 | error = 1; | |
128 | goto out; | |
129 | } | |
130 | ||
131 | /** | |
a59322be | 132 | * __skb_recv_datagram - Receive a datagram skbuff |
4dc3b16b PP |
133 | * @sk: socket |
134 | * @flags: MSG_ flags | |
a59322be | 135 | * @peeked: returns non-zero if this packet has been seen before |
4dc3b16b | 136 | * @err: error code returned |
1da177e4 LT |
137 | * |
138 | * Get a datagram skbuff, understands the peeking, nonblocking wakeups | |
139 | * and possible races. This replaces identical code in packet, raw and | |
140 | * udp, as well as the IPX AX.25 and Appletalk. It also finally fixes | |
141 | * the long standing peek and read race for datagram sockets. If you | |
142 | * alter this routine remember it must be re-entrant. | |
143 | * | |
144 | * This function will lock the socket if a skb is returned, so the caller | |
145 | * needs to unlock the socket in that case (usually by calling | |
146 | * skb_free_datagram) | |
147 | * | |
148 | * * It does not lock socket since today. This function is | |
149 | * * free of race conditions. This measure should/can improve | |
150 | * * significantly datagram socket latencies at high loads, | |
151 | * * when data copying to user space takes lots of time. | |
152 | * * (BTW I've just killed the last cli() in IP/IPv6/core/netlink/packet | |
153 | * * 8) Great win.) | |
154 | * * --ANK (980729) | |
155 | * | |
156 | * The order of the tests when we find no data waiting are specified | |
157 | * quite explicitly by POSIX 1003.1g, don't change them without having | |
158 | * the standard around please. | |
159 | */ | |
a59322be HX |
160 | struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, |
161 | int *peeked, int *err) | |
1da177e4 LT |
162 | { |
163 | struct sk_buff *skb; | |
164 | long timeo; | |
165 | /* | |
166 | * Caller is allowed not to check sk->sk_err before skb_recv_datagram() | |
167 | */ | |
168 | int error = sock_error(sk); | |
169 | ||
170 | if (error) | |
171 | goto no_packet; | |
172 | ||
a59322be | 173 | timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); |
1da177e4 LT |
174 | |
175 | do { | |
176 | /* Again only user level code calls this function, so nothing | |
177 | * interrupt level will suddenly eat the receive_queue. | |
178 | * | |
179 | * Look at current nfs client by the way... | |
8917a3c0 | 180 | * However, this function was correct in any case. 8) |
1da177e4 | 181 | */ |
a59322be HX |
182 | unsigned long cpu_flags; |
183 | ||
184 | spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags); | |
185 | skb = skb_peek(&sk->sk_receive_queue); | |
186 | if (skb) { | |
187 | *peeked = skb->peeked; | |
188 | if (flags & MSG_PEEK) { | |
189 | skb->peeked = 1; | |
1da177e4 | 190 | atomic_inc(&skb->users); |
a59322be HX |
191 | } else |
192 | __skb_unlink(skb, &sk->sk_receive_queue); | |
193 | } | |
194 | spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags); | |
1da177e4 LT |
195 | |
196 | if (skb) | |
197 | return skb; | |
198 | ||
199 | /* User doesn't want to wait */ | |
200 | error = -EAGAIN; | |
201 | if (!timeo) | |
202 | goto no_packet; | |
203 | ||
204 | } while (!wait_for_packet(sk, err, &timeo)); | |
205 | ||
206 | return NULL; | |
207 | ||
208 | no_packet: | |
209 | *err = error; | |
210 | return NULL; | |
211 | } | |
a59322be HX |
212 | EXPORT_SYMBOL(__skb_recv_datagram); |
213 | ||
214 | struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, | |
215 | int noblock, int *err) | |
216 | { | |
217 | int peeked; | |
218 | ||
219 | return __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), | |
220 | &peeked, err); | |
221 | } | |
9e34a5b5 | 222 | EXPORT_SYMBOL(skb_recv_datagram); |
1da177e4 LT |
223 | |
224 | void skb_free_datagram(struct sock *sk, struct sk_buff *skb) | |
225 | { | |
ead2ceb0 | 226 | consume_skb(skb); |
270acefa | 227 | sk_mem_reclaim_partial(sk); |
1da177e4 | 228 | } |
9d410c79 ED |
229 | EXPORT_SYMBOL(skb_free_datagram); |
230 | ||
231 | void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb) | |
232 | { | |
8a74ad60 ED |
233 | bool slow; |
234 | ||
93bb64ea ED |
235 | if (likely(atomic_read(&skb->users) == 1)) |
236 | smp_rmb(); | |
237 | else if (likely(!atomic_dec_and_test(&skb->users))) | |
238 | return; | |
239 | ||
8a74ad60 | 240 | slow = lock_sock_fast(sk); |
4b0b72f7 ED |
241 | skb_orphan(skb); |
242 | sk_mem_reclaim_partial(sk); | |
8a74ad60 | 243 | unlock_sock_fast(sk, slow); |
4b0b72f7 | 244 | |
93bb64ea | 245 | /* skb is now orphaned, can be freed outside of locked section */ |
07dc22e7 | 246 | trace_kfree_skb(skb, skb_free_datagram_locked); |
93bb64ea | 247 | __kfree_skb(skb); |
9d410c79 ED |
248 | } |
249 | EXPORT_SYMBOL(skb_free_datagram_locked); | |
1da177e4 | 250 | |
3305b80c HX |
251 | /** |
252 | * skb_kill_datagram - Free a datagram skbuff forcibly | |
253 | * @sk: socket | |
254 | * @skb: datagram skbuff | |
255 | * @flags: MSG_ flags | |
256 | * | |
257 | * This function frees a datagram skbuff that was received by | |
258 | * skb_recv_datagram. The flags argument must match the one | |
259 | * used for skb_recv_datagram. | |
260 | * | |
261 | * If the MSG_PEEK flag is set, and the packet is still on the | |
262 | * receive queue of the socket, it will be taken off the queue | |
263 | * before it is freed. | |
264 | * | |
265 | * This function currently only disables BH when acquiring the | |
266 | * sk_receive_queue lock. Therefore it must not be used in a | |
267 | * context where that lock is acquired in an IRQ context. | |
27ab2568 HX |
268 | * |
269 | * It returns 0 if the packet was removed by us. | |
3305b80c HX |
270 | */ |
271 | ||
27ab2568 | 272 | int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags) |
3305b80c | 273 | { |
27ab2568 HX |
274 | int err = 0; |
275 | ||
3305b80c | 276 | if (flags & MSG_PEEK) { |
27ab2568 | 277 | err = -ENOENT; |
3305b80c HX |
278 | spin_lock_bh(&sk->sk_receive_queue.lock); |
279 | if (skb == skb_peek(&sk->sk_receive_queue)) { | |
280 | __skb_unlink(skb, &sk->sk_receive_queue); | |
281 | atomic_dec(&skb->users); | |
27ab2568 | 282 | err = 0; |
3305b80c HX |
283 | } |
284 | spin_unlock_bh(&sk->sk_receive_queue.lock); | |
285 | } | |
286 | ||
61de71c6 | 287 | kfree_skb(skb); |
8edf19c2 | 288 | atomic_inc(&sk->sk_drops); |
61de71c6 JD |
289 | sk_mem_reclaim_partial(sk); |
290 | ||
27ab2568 | 291 | return err; |
3305b80c | 292 | } |
3305b80c HX |
293 | EXPORT_SYMBOL(skb_kill_datagram); |
294 | ||
1da177e4 LT |
295 | /** |
296 | * skb_copy_datagram_iovec - Copy a datagram to an iovec. | |
4dc3b16b PP |
297 | * @skb: buffer to copy |
298 | * @offset: offset in the buffer to start copying from | |
67be2dd1 | 299 | * @to: io vector to copy to |
4dc3b16b | 300 | * @len: amount of data to copy from buffer to iovec |
1da177e4 LT |
301 | * |
302 | * Note: the iovec is modified during the copy. | |
303 | */ | |
304 | int skb_copy_datagram_iovec(const struct sk_buff *skb, int offset, | |
305 | struct iovec *to, int len) | |
306 | { | |
1a028e50 DM |
307 | int start = skb_headlen(skb); |
308 | int i, copy = start - offset; | |
5b1a002a | 309 | struct sk_buff *frag_iter; |
c75d721c | 310 | |
e9b3cc1b NH |
311 | trace_skb_copy_datagram_iovec(skb, len); |
312 | ||
b4d9eda0 DM |
313 | /* Copy header. */ |
314 | if (copy > 0) { | |
315 | if (copy > len) | |
316 | copy = len; | |
317 | if (memcpy_toiovec(to, skb->data + offset, copy)) | |
318 | goto fault; | |
319 | if ((len -= copy) == 0) | |
320 | return 0; | |
321 | offset += copy; | |
322 | } | |
c75d721c | 323 | |
b4d9eda0 DM |
324 | /* Copy paged appendix. Hmm... why does this look so complicated? */ |
325 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { | |
1a028e50 | 326 | int end; |
1da177e4 | 327 | |
547b792c | 328 | WARN_ON(start > offset + len); |
1a028e50 DM |
329 | |
330 | end = start + skb_shinfo(skb)->frags[i].size; | |
b4d9eda0 DM |
331 | if ((copy = end - offset) > 0) { |
332 | int err; | |
333 | u8 *vaddr; | |
334 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
ea2ab693 | 335 | struct page *page = skb_frag_page(frag); |
1da177e4 LT |
336 | |
337 | if (copy > len) | |
338 | copy = len; | |
b4d9eda0 | 339 | vaddr = kmap(page); |
1a028e50 DM |
340 | err = memcpy_toiovec(to, vaddr + frag->page_offset + |
341 | offset - start, copy); | |
b4d9eda0 | 342 | kunmap(page); |
1da177e4 LT |
343 | if (err) |
344 | goto fault; | |
345 | if (!(len -= copy)) | |
346 | return 0; | |
347 | offset += copy; | |
348 | } | |
1a028e50 | 349 | start = end; |
1da177e4 | 350 | } |
b4d9eda0 | 351 | |
5b1a002a DM |
352 | skb_walk_frags(skb, frag_iter) { |
353 | int end; | |
354 | ||
355 | WARN_ON(start > offset + len); | |
356 | ||
357 | end = start + frag_iter->len; | |
358 | if ((copy = end - offset) > 0) { | |
359 | if (copy > len) | |
360 | copy = len; | |
361 | if (skb_copy_datagram_iovec(frag_iter, | |
362 | offset - start, | |
363 | to, copy)) | |
364 | goto fault; | |
365 | if ((len -= copy) == 0) | |
366 | return 0; | |
367 | offset += copy; | |
b4d9eda0 | 368 | } |
5b1a002a | 369 | start = end; |
1da177e4 | 370 | } |
b4d9eda0 DM |
371 | if (!len) |
372 | return 0; | |
373 | ||
1da177e4 LT |
374 | fault: |
375 | return -EFAULT; | |
376 | } | |
9e34a5b5 | 377 | EXPORT_SYMBOL(skb_copy_datagram_iovec); |
1da177e4 | 378 | |
0a1ec07a MT |
379 | /** |
380 | * skb_copy_datagram_const_iovec - Copy a datagram to an iovec. | |
381 | * @skb: buffer to copy | |
382 | * @offset: offset in the buffer to start copying from | |
383 | * @to: io vector to copy to | |
384 | * @to_offset: offset in the io vector to start copying to | |
385 | * @len: amount of data to copy from buffer to iovec | |
386 | * | |
387 | * Returns 0 or -EFAULT. | |
388 | * Note: the iovec is not modified during the copy. | |
389 | */ | |
390 | int skb_copy_datagram_const_iovec(const struct sk_buff *skb, int offset, | |
391 | const struct iovec *to, int to_offset, | |
392 | int len) | |
393 | { | |
394 | int start = skb_headlen(skb); | |
395 | int i, copy = start - offset; | |
5b1a002a | 396 | struct sk_buff *frag_iter; |
0a1ec07a MT |
397 | |
398 | /* Copy header. */ | |
399 | if (copy > 0) { | |
400 | if (copy > len) | |
401 | copy = len; | |
402 | if (memcpy_toiovecend(to, skb->data + offset, to_offset, copy)) | |
403 | goto fault; | |
404 | if ((len -= copy) == 0) | |
405 | return 0; | |
406 | offset += copy; | |
407 | to_offset += copy; | |
408 | } | |
409 | ||
410 | /* Copy paged appendix. Hmm... why does this look so complicated? */ | |
411 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { | |
412 | int end; | |
413 | ||
414 | WARN_ON(start > offset + len); | |
415 | ||
416 | end = start + skb_shinfo(skb)->frags[i].size; | |
417 | if ((copy = end - offset) > 0) { | |
418 | int err; | |
419 | u8 *vaddr; | |
420 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
ea2ab693 | 421 | struct page *page = skb_frag_page(frag); |
0a1ec07a MT |
422 | |
423 | if (copy > len) | |
424 | copy = len; | |
425 | vaddr = kmap(page); | |
426 | err = memcpy_toiovecend(to, vaddr + frag->page_offset + | |
427 | offset - start, to_offset, copy); | |
428 | kunmap(page); | |
429 | if (err) | |
430 | goto fault; | |
431 | if (!(len -= copy)) | |
432 | return 0; | |
433 | offset += copy; | |
434 | to_offset += copy; | |
435 | } | |
436 | start = end; | |
437 | } | |
438 | ||
5b1a002a DM |
439 | skb_walk_frags(skb, frag_iter) { |
440 | int end; | |
441 | ||
442 | WARN_ON(start > offset + len); | |
443 | ||
444 | end = start + frag_iter->len; | |
445 | if ((copy = end - offset) > 0) { | |
446 | if (copy > len) | |
447 | copy = len; | |
448 | if (skb_copy_datagram_const_iovec(frag_iter, | |
449 | offset - start, | |
450 | to, to_offset, | |
451 | copy)) | |
452 | goto fault; | |
453 | if ((len -= copy) == 0) | |
454 | return 0; | |
455 | offset += copy; | |
456 | to_offset += copy; | |
0a1ec07a | 457 | } |
5b1a002a | 458 | start = end; |
0a1ec07a MT |
459 | } |
460 | if (!len) | |
461 | return 0; | |
462 | ||
463 | fault: | |
464 | return -EFAULT; | |
465 | } | |
466 | EXPORT_SYMBOL(skb_copy_datagram_const_iovec); | |
467 | ||
db543c1f RR |
468 | /** |
469 | * skb_copy_datagram_from_iovec - Copy a datagram from an iovec. | |
470 | * @skb: buffer to copy | |
471 | * @offset: offset in the buffer to start copying to | |
472 | * @from: io vector to copy to | |
6f26c9a7 | 473 | * @from_offset: offset in the io vector to start copying from |
db543c1f RR |
474 | * @len: amount of data to copy to buffer from iovec |
475 | * | |
476 | * Returns 0 or -EFAULT. | |
6f26c9a7 | 477 | * Note: the iovec is not modified during the copy. |
db543c1f RR |
478 | */ |
479 | int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset, | |
6f26c9a7 MT |
480 | const struct iovec *from, int from_offset, |
481 | int len) | |
db543c1f RR |
482 | { |
483 | int start = skb_headlen(skb); | |
484 | int i, copy = start - offset; | |
5b1a002a | 485 | struct sk_buff *frag_iter; |
db543c1f RR |
486 | |
487 | /* Copy header. */ | |
488 | if (copy > 0) { | |
489 | if (copy > len) | |
490 | copy = len; | |
d2d27bfd SS |
491 | if (memcpy_fromiovecend(skb->data + offset, from, from_offset, |
492 | copy)) | |
db543c1f RR |
493 | goto fault; |
494 | if ((len -= copy) == 0) | |
495 | return 0; | |
496 | offset += copy; | |
6f26c9a7 | 497 | from_offset += copy; |
db543c1f RR |
498 | } |
499 | ||
500 | /* Copy paged appendix. Hmm... why does this look so complicated? */ | |
501 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { | |
502 | int end; | |
503 | ||
504 | WARN_ON(start > offset + len); | |
505 | ||
506 | end = start + skb_shinfo(skb)->frags[i].size; | |
507 | if ((copy = end - offset) > 0) { | |
508 | int err; | |
509 | u8 *vaddr; | |
510 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
ea2ab693 | 511 | struct page *page = skb_frag_page(frag); |
db543c1f RR |
512 | |
513 | if (copy > len) | |
514 | copy = len; | |
515 | vaddr = kmap(page); | |
6f26c9a7 MT |
516 | err = memcpy_fromiovecend(vaddr + frag->page_offset + |
517 | offset - start, | |
518 | from, from_offset, copy); | |
db543c1f RR |
519 | kunmap(page); |
520 | if (err) | |
521 | goto fault; | |
522 | ||
523 | if (!(len -= copy)) | |
524 | return 0; | |
525 | offset += copy; | |
6f26c9a7 | 526 | from_offset += copy; |
db543c1f RR |
527 | } |
528 | start = end; | |
529 | } | |
530 | ||
5b1a002a DM |
531 | skb_walk_frags(skb, frag_iter) { |
532 | int end; | |
533 | ||
534 | WARN_ON(start > offset + len); | |
535 | ||
536 | end = start + frag_iter->len; | |
537 | if ((copy = end - offset) > 0) { | |
538 | if (copy > len) | |
539 | copy = len; | |
540 | if (skb_copy_datagram_from_iovec(frag_iter, | |
541 | offset - start, | |
542 | from, | |
543 | from_offset, | |
544 | copy)) | |
545 | goto fault; | |
546 | if ((len -= copy) == 0) | |
547 | return 0; | |
548 | offset += copy; | |
549 | from_offset += copy; | |
db543c1f | 550 | } |
5b1a002a | 551 | start = end; |
db543c1f RR |
552 | } |
553 | if (!len) | |
554 | return 0; | |
555 | ||
556 | fault: | |
557 | return -EFAULT; | |
558 | } | |
559 | EXPORT_SYMBOL(skb_copy_datagram_from_iovec); | |
560 | ||
1da177e4 LT |
561 | static int skb_copy_and_csum_datagram(const struct sk_buff *skb, int offset, |
562 | u8 __user *to, int len, | |
5084205f | 563 | __wsum *csump) |
1da177e4 | 564 | { |
1a028e50 | 565 | int start = skb_headlen(skb); |
1a028e50 | 566 | int i, copy = start - offset; |
5b1a002a DM |
567 | struct sk_buff *frag_iter; |
568 | int pos = 0; | |
1da177e4 LT |
569 | |
570 | /* Copy header. */ | |
571 | if (copy > 0) { | |
572 | int err = 0; | |
573 | if (copy > len) | |
574 | copy = len; | |
575 | *csump = csum_and_copy_to_user(skb->data + offset, to, copy, | |
576 | *csump, &err); | |
577 | if (err) | |
578 | goto fault; | |
579 | if ((len -= copy) == 0) | |
580 | return 0; | |
581 | offset += copy; | |
582 | to += copy; | |
583 | pos = copy; | |
584 | } | |
585 | ||
586 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { | |
1a028e50 | 587 | int end; |
1da177e4 | 588 | |
547b792c | 589 | WARN_ON(start > offset + len); |
1a028e50 DM |
590 | |
591 | end = start + skb_shinfo(skb)->frags[i].size; | |
1da177e4 | 592 | if ((copy = end - offset) > 0) { |
5084205f | 593 | __wsum csum2; |
1da177e4 LT |
594 | int err = 0; |
595 | u8 *vaddr; | |
596 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
ea2ab693 | 597 | struct page *page = skb_frag_page(frag); |
1da177e4 LT |
598 | |
599 | if (copy > len) | |
600 | copy = len; | |
601 | vaddr = kmap(page); | |
602 | csum2 = csum_and_copy_to_user(vaddr + | |
1a028e50 DM |
603 | frag->page_offset + |
604 | offset - start, | |
1da177e4 LT |
605 | to, copy, 0, &err); |
606 | kunmap(page); | |
607 | if (err) | |
608 | goto fault; | |
609 | *csump = csum_block_add(*csump, csum2, pos); | |
610 | if (!(len -= copy)) | |
611 | return 0; | |
612 | offset += copy; | |
613 | to += copy; | |
614 | pos += copy; | |
615 | } | |
1a028e50 | 616 | start = end; |
1da177e4 LT |
617 | } |
618 | ||
5b1a002a DM |
619 | skb_walk_frags(skb, frag_iter) { |
620 | int end; | |
621 | ||
622 | WARN_ON(start > offset + len); | |
623 | ||
624 | end = start + frag_iter->len; | |
625 | if ((copy = end - offset) > 0) { | |
626 | __wsum csum2 = 0; | |
627 | if (copy > len) | |
628 | copy = len; | |
629 | if (skb_copy_and_csum_datagram(frag_iter, | |
630 | offset - start, | |
631 | to, copy, | |
632 | &csum2)) | |
633 | goto fault; | |
634 | *csump = csum_block_add(*csump, csum2, pos); | |
635 | if ((len -= copy) == 0) | |
636 | return 0; | |
637 | offset += copy; | |
638 | to += copy; | |
639 | pos += copy; | |
1da177e4 | 640 | } |
5b1a002a | 641 | start = end; |
1da177e4 LT |
642 | } |
643 | if (!len) | |
644 | return 0; | |
645 | ||
646 | fault: | |
647 | return -EFAULT; | |
648 | } | |
649 | ||
759e5d00 | 650 | __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len) |
fb286bb2 | 651 | { |
d3bc23e7 | 652 | __sum16 sum; |
fb286bb2 | 653 | |
759e5d00 | 654 | sum = csum_fold(skb_checksum(skb, 0, len, skb->csum)); |
fb286bb2 | 655 | if (likely(!sum)) { |
84fa7933 | 656 | if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) |
fb286bb2 HX |
657 | netdev_rx_csum_fault(skb->dev); |
658 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
659 | } | |
660 | return sum; | |
661 | } | |
759e5d00 HX |
662 | EXPORT_SYMBOL(__skb_checksum_complete_head); |
663 | ||
664 | __sum16 __skb_checksum_complete(struct sk_buff *skb) | |
665 | { | |
666 | return __skb_checksum_complete_head(skb, skb->len); | |
667 | } | |
fb286bb2 HX |
668 | EXPORT_SYMBOL(__skb_checksum_complete); |
669 | ||
1da177e4 LT |
670 | /** |
671 | * skb_copy_and_csum_datagram_iovec - Copy and checkum skb to user iovec. | |
4dc3b16b PP |
672 | * @skb: skbuff |
673 | * @hlen: hardware length | |
67be2dd1 | 674 | * @iov: io vector |
4ec93edb | 675 | * |
1da177e4 LT |
676 | * Caller _must_ check that skb will fit to this iovec. |
677 | * | |
678 | * Returns: 0 - success. | |
679 | * -EINVAL - checksum failure. | |
680 | * -EFAULT - fault during copy. Beware, in this case iovec | |
681 | * can be modified! | |
682 | */ | |
fb286bb2 | 683 | int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, |
1da177e4 LT |
684 | int hlen, struct iovec *iov) |
685 | { | |
d3bc23e7 | 686 | __wsum csum; |
1da177e4 LT |
687 | int chunk = skb->len - hlen; |
688 | ||
ef8aef55 HX |
689 | if (!chunk) |
690 | return 0; | |
691 | ||
1da177e4 LT |
692 | /* Skip filled elements. |
693 | * Pretty silly, look at memcpy_toiovec, though 8) | |
694 | */ | |
695 | while (!iov->iov_len) | |
696 | iov++; | |
697 | ||
698 | if (iov->iov_len < chunk) { | |
fb286bb2 | 699 | if (__skb_checksum_complete(skb)) |
1da177e4 LT |
700 | goto csum_error; |
701 | if (skb_copy_datagram_iovec(skb, hlen, iov, chunk)) | |
702 | goto fault; | |
703 | } else { | |
704 | csum = csum_partial(skb->data, hlen, skb->csum); | |
705 | if (skb_copy_and_csum_datagram(skb, hlen, iov->iov_base, | |
706 | chunk, &csum)) | |
707 | goto fault; | |
d3bc23e7 | 708 | if (csum_fold(csum)) |
1da177e4 | 709 | goto csum_error; |
84fa7933 | 710 | if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) |
fb286bb2 | 711 | netdev_rx_csum_fault(skb->dev); |
1da177e4 LT |
712 | iov->iov_len -= chunk; |
713 | iov->iov_base += chunk; | |
714 | } | |
715 | return 0; | |
716 | csum_error: | |
717 | return -EINVAL; | |
718 | fault: | |
719 | return -EFAULT; | |
720 | } | |
9e34a5b5 | 721 | EXPORT_SYMBOL(skb_copy_and_csum_datagram_iovec); |
1da177e4 LT |
722 | |
723 | /** | |
724 | * datagram_poll - generic datagram poll | |
4dc3b16b PP |
725 | * @file: file struct |
726 | * @sock: socket | |
727 | * @wait: poll table | |
1da177e4 LT |
728 | * |
729 | * Datagram poll: Again totally generic. This also handles | |
730 | * sequenced packet sockets providing the socket receive queue | |
731 | * is only ever holding data ready to receive. | |
732 | * | |
733 | * Note: when you _don't_ use this routine for this protocol, | |
734 | * and you use a different write policy from sock_writeable() | |
735 | * then please supply your own write_space callback. | |
736 | */ | |
737 | unsigned int datagram_poll(struct file *file, struct socket *sock, | |
738 | poll_table *wait) | |
739 | { | |
740 | struct sock *sk = sock->sk; | |
741 | unsigned int mask; | |
742 | ||
aa395145 | 743 | sock_poll_wait(file, sk_sleep(sk), wait); |
1da177e4 LT |
744 | mask = 0; |
745 | ||
746 | /* exceptional events? */ | |
747 | if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue)) | |
748 | mask |= POLLERR; | |
f348d70a | 749 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
db40980f | 750 | mask |= POLLRDHUP | POLLIN | POLLRDNORM; |
1da177e4 LT |
751 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
752 | mask |= POLLHUP; | |
753 | ||
754 | /* readable? */ | |
db40980f | 755 | if (!skb_queue_empty(&sk->sk_receive_queue)) |
1da177e4 LT |
756 | mask |= POLLIN | POLLRDNORM; |
757 | ||
758 | /* Connection-based need to check for termination and startup */ | |
759 | if (connection_based(sk)) { | |
760 | if (sk->sk_state == TCP_CLOSE) | |
761 | mask |= POLLHUP; | |
762 | /* connection hasn't started yet? */ | |
763 | if (sk->sk_state == TCP_SYN_SENT) | |
764 | return mask; | |
765 | } | |
766 | ||
767 | /* writable? */ | |
768 | if (sock_writeable(sk)) | |
769 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
770 | else | |
771 | set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); | |
772 | ||
773 | return mask; | |
774 | } | |
1da177e4 | 775 | EXPORT_SYMBOL(datagram_poll); |