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17926a79 DH |
1 | /* RxRPC recvmsg() implementation |
2 | * | |
3 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/net.h> | |
13 | #include <linux/skbuff.h> | |
14 | #include <net/sock.h> | |
15 | #include <net/af_rxrpc.h> | |
16 | #include "ar-internal.h" | |
17 | ||
18 | /* | |
19 | * removal a call's user ID from the socket tree to make the user ID available | |
20 | * again and so that it won't be seen again in association with that call | |
21 | */ | |
651350d1 | 22 | void rxrpc_remove_user_ID(struct rxrpc_sock *rx, struct rxrpc_call *call) |
17926a79 DH |
23 | { |
24 | _debug("RELEASE CALL %d", call->debug_id); | |
25 | ||
26 | if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { | |
27 | write_lock_bh(&rx->call_lock); | |
28 | rb_erase(&call->sock_node, &call->socket->calls); | |
29 | clear_bit(RXRPC_CALL_HAS_USERID, &call->flags); | |
30 | write_unlock_bh(&rx->call_lock); | |
31 | } | |
32 | ||
33 | read_lock_bh(&call->state_lock); | |
34 | if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && | |
35 | !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) | |
651350d1 | 36 | rxrpc_queue_call(call); |
17926a79 DH |
37 | read_unlock_bh(&call->state_lock); |
38 | } | |
39 | ||
40 | /* | |
41 | * receive a message from an RxRPC socket | |
42 | * - we need to be careful about two or more threads calling recvmsg | |
43 | * simultaneously | |
44 | */ | |
45 | int rxrpc_recvmsg(struct kiocb *iocb, struct socket *sock, | |
46 | struct msghdr *msg, size_t len, int flags) | |
47 | { | |
48 | struct rxrpc_skb_priv *sp; | |
49 | struct rxrpc_call *call = NULL, *continue_call = NULL; | |
50 | struct rxrpc_sock *rx = rxrpc_sk(sock->sk); | |
51 | struct sk_buff *skb; | |
52 | long timeo; | |
53 | int copy, ret, ullen, offset, copied = 0; | |
54 | u32 abort_code; | |
55 | ||
56 | DEFINE_WAIT(wait); | |
57 | ||
58 | _enter(",,,%zu,%d", len, flags); | |
59 | ||
60 | if (flags & (MSG_OOB | MSG_TRUNC)) | |
61 | return -EOPNOTSUPP; | |
62 | ||
63 | ullen = msg->msg_flags & MSG_CMSG_COMPAT ? 4 : sizeof(unsigned long); | |
64 | ||
65 | timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT); | |
66 | msg->msg_flags |= MSG_MORE; | |
67 | ||
68 | lock_sock(&rx->sk); | |
69 | ||
70 | for (;;) { | |
71 | /* return immediately if a client socket has no outstanding | |
72 | * calls */ | |
73 | if (RB_EMPTY_ROOT(&rx->calls)) { | |
74 | if (copied) | |
75 | goto out; | |
76 | if (rx->sk.sk_state != RXRPC_SERVER_LISTENING) { | |
77 | release_sock(&rx->sk); | |
78 | if (continue_call) | |
79 | rxrpc_put_call(continue_call); | |
80 | return -ENODATA; | |
81 | } | |
82 | } | |
83 | ||
84 | /* get the next message on the Rx queue */ | |
85 | skb = skb_peek(&rx->sk.sk_receive_queue); | |
86 | if (!skb) { | |
87 | /* nothing remains on the queue */ | |
88 | if (copied && | |
89 | (msg->msg_flags & MSG_PEEK || timeo == 0)) | |
90 | goto out; | |
91 | ||
92 | /* wait for a message to turn up */ | |
93 | release_sock(&rx->sk); | |
94 | prepare_to_wait_exclusive(rx->sk.sk_sleep, &wait, | |
95 | TASK_INTERRUPTIBLE); | |
96 | ret = sock_error(&rx->sk); | |
97 | if (ret) | |
98 | goto wait_error; | |
99 | ||
100 | if (skb_queue_empty(&rx->sk.sk_receive_queue)) { | |
101 | if (signal_pending(current)) | |
102 | goto wait_interrupted; | |
103 | timeo = schedule_timeout(timeo); | |
104 | } | |
105 | finish_wait(rx->sk.sk_sleep, &wait); | |
106 | lock_sock(&rx->sk); | |
107 | continue; | |
108 | } | |
109 | ||
110 | peek_next_packet: | |
111 | sp = rxrpc_skb(skb); | |
112 | call = sp->call; | |
113 | ASSERT(call != NULL); | |
114 | ||
115 | _debug("next pkt %s", rxrpc_pkts[sp->hdr.type]); | |
116 | ||
117 | /* make sure we wait for the state to be updated in this call */ | |
118 | spin_lock_bh(&call->lock); | |
119 | spin_unlock_bh(&call->lock); | |
120 | ||
121 | if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) { | |
122 | _debug("packet from released call"); | |
123 | if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) | |
124 | BUG(); | |
125 | rxrpc_free_skb(skb); | |
126 | continue; | |
127 | } | |
128 | ||
129 | /* determine whether to continue last data receive */ | |
130 | if (continue_call) { | |
131 | _debug("maybe cont"); | |
132 | if (call != continue_call || | |
133 | skb->mark != RXRPC_SKB_MARK_DATA) { | |
134 | release_sock(&rx->sk); | |
135 | rxrpc_put_call(continue_call); | |
136 | _leave(" = %d [noncont]", copied); | |
137 | return copied; | |
138 | } | |
139 | } | |
140 | ||
141 | rxrpc_get_call(call); | |
142 | ||
143 | /* copy the peer address and timestamp */ | |
144 | if (!continue_call) { | |
145 | if (msg->msg_name && msg->msg_namelen > 0) | |
146 | memcpy(&msg->msg_name, &call->conn->trans->peer->srx, | |
147 | sizeof(call->conn->trans->peer->srx)); | |
148 | sock_recv_timestamp(msg, &rx->sk, skb); | |
149 | } | |
150 | ||
151 | /* receive the message */ | |
152 | if (skb->mark != RXRPC_SKB_MARK_DATA) | |
153 | goto receive_non_data_message; | |
154 | ||
155 | _debug("recvmsg DATA #%u { %d, %d }", | |
156 | ntohl(sp->hdr.seq), skb->len, sp->offset); | |
157 | ||
158 | if (!continue_call) { | |
159 | /* only set the control data once per recvmsg() */ | |
160 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, | |
161 | ullen, &call->user_call_ID); | |
162 | if (ret < 0) | |
163 | goto copy_error; | |
164 | ASSERT(test_bit(RXRPC_CALL_HAS_USERID, &call->flags)); | |
165 | } | |
166 | ||
167 | ASSERTCMP(ntohl(sp->hdr.seq), >=, call->rx_data_recv); | |
168 | ASSERTCMP(ntohl(sp->hdr.seq), <=, call->rx_data_recv + 1); | |
169 | call->rx_data_recv = ntohl(sp->hdr.seq); | |
170 | ||
171 | ASSERTCMP(ntohl(sp->hdr.seq), >, call->rx_data_eaten); | |
172 | ||
173 | offset = sp->offset; | |
174 | copy = skb->len - offset; | |
175 | if (copy > len - copied) | |
176 | copy = len - copied; | |
177 | ||
178 | if (skb->ip_summed == CHECKSUM_UNNECESSARY) { | |
179 | ret = skb_copy_datagram_iovec(skb, offset, | |
180 | msg->msg_iov, copy); | |
181 | } else { | |
182 | ret = skb_copy_and_csum_datagram_iovec(skb, offset, | |
183 | msg->msg_iov); | |
184 | if (ret == -EINVAL) | |
185 | goto csum_copy_error; | |
186 | } | |
187 | ||
188 | if (ret < 0) | |
189 | goto copy_error; | |
190 | ||
191 | /* handle piecemeal consumption of data packets */ | |
192 | _debug("copied %d+%d", copy, copied); | |
193 | ||
194 | offset += copy; | |
195 | copied += copy; | |
196 | ||
197 | if (!(flags & MSG_PEEK)) | |
198 | sp->offset = offset; | |
199 | ||
200 | if (sp->offset < skb->len) { | |
201 | _debug("buffer full"); | |
202 | ASSERTCMP(copied, ==, len); | |
203 | break; | |
204 | } | |
205 | ||
206 | /* we transferred the whole data packet */ | |
207 | if (sp->hdr.flags & RXRPC_LAST_PACKET) { | |
208 | _debug("last"); | |
209 | if (call->conn->out_clientflag) { | |
210 | /* last byte of reply received */ | |
211 | ret = copied; | |
212 | goto terminal_message; | |
213 | } | |
214 | ||
215 | /* last bit of request received */ | |
216 | if (!(flags & MSG_PEEK)) { | |
217 | _debug("eat packet"); | |
218 | if (skb_dequeue(&rx->sk.sk_receive_queue) != | |
219 | skb) | |
220 | BUG(); | |
221 | rxrpc_free_skb(skb); | |
222 | } | |
223 | msg->msg_flags &= ~MSG_MORE; | |
224 | break; | |
225 | } | |
226 | ||
227 | /* move on to the next data message */ | |
228 | _debug("next"); | |
229 | if (!continue_call) | |
230 | continue_call = sp->call; | |
231 | else | |
232 | rxrpc_put_call(call); | |
233 | call = NULL; | |
234 | ||
235 | if (flags & MSG_PEEK) { | |
236 | _debug("peek next"); | |
237 | skb = skb->next; | |
238 | if (skb == (struct sk_buff *) &rx->sk.sk_receive_queue) | |
239 | break; | |
240 | goto peek_next_packet; | |
241 | } | |
242 | ||
243 | _debug("eat packet"); | |
244 | if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) | |
245 | BUG(); | |
246 | rxrpc_free_skb(skb); | |
247 | } | |
248 | ||
249 | /* end of non-terminal data packet reception for the moment */ | |
250 | _debug("end rcv data"); | |
251 | out: | |
252 | release_sock(&rx->sk); | |
253 | if (call) | |
254 | rxrpc_put_call(call); | |
255 | if (continue_call) | |
256 | rxrpc_put_call(continue_call); | |
257 | _leave(" = %d [data]", copied); | |
258 | return copied; | |
259 | ||
260 | /* handle non-DATA messages such as aborts, incoming connections and | |
261 | * final ACKs */ | |
262 | receive_non_data_message: | |
263 | _debug("non-data"); | |
264 | ||
265 | if (skb->mark == RXRPC_SKB_MARK_NEW_CALL) { | |
266 | _debug("RECV NEW CALL"); | |
267 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NEW_CALL, 0, &abort_code); | |
268 | if (ret < 0) | |
269 | goto copy_error; | |
270 | if (!(flags & MSG_PEEK)) { | |
271 | if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) | |
272 | BUG(); | |
273 | rxrpc_free_skb(skb); | |
274 | } | |
275 | goto out; | |
276 | } | |
277 | ||
278 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, | |
279 | ullen, &call->user_call_ID); | |
280 | if (ret < 0) | |
281 | goto copy_error; | |
282 | ASSERT(test_bit(RXRPC_CALL_HAS_USERID, &call->flags)); | |
283 | ||
284 | switch (skb->mark) { | |
285 | case RXRPC_SKB_MARK_DATA: | |
286 | BUG(); | |
287 | case RXRPC_SKB_MARK_FINAL_ACK: | |
288 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ACK, 0, &abort_code); | |
289 | break; | |
290 | case RXRPC_SKB_MARK_BUSY: | |
291 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_BUSY, 0, &abort_code); | |
292 | break; | |
293 | case RXRPC_SKB_MARK_REMOTE_ABORT: | |
294 | abort_code = call->abort_code; | |
295 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &abort_code); | |
296 | break; | |
297 | case RXRPC_SKB_MARK_NET_ERROR: | |
298 | _debug("RECV NET ERROR %d", sp->error); | |
299 | abort_code = sp->error; | |
300 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NET_ERROR, 4, &abort_code); | |
301 | break; | |
302 | case RXRPC_SKB_MARK_LOCAL_ERROR: | |
303 | _debug("RECV LOCAL ERROR %d", sp->error); | |
304 | abort_code = sp->error; | |
305 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_LOCAL_ERROR, 4, | |
306 | &abort_code); | |
307 | break; | |
308 | default: | |
309 | BUG(); | |
310 | break; | |
311 | } | |
312 | ||
313 | if (ret < 0) | |
314 | goto copy_error; | |
315 | ||
316 | terminal_message: | |
317 | _debug("terminal"); | |
318 | msg->msg_flags &= ~MSG_MORE; | |
319 | msg->msg_flags |= MSG_EOR; | |
320 | ||
321 | if (!(flags & MSG_PEEK)) { | |
322 | _net("free terminal skb %p", skb); | |
323 | if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) | |
324 | BUG(); | |
325 | rxrpc_free_skb(skb); | |
326 | rxrpc_remove_user_ID(rx, call); | |
327 | } | |
328 | ||
329 | release_sock(&rx->sk); | |
330 | rxrpc_put_call(call); | |
331 | if (continue_call) | |
332 | rxrpc_put_call(continue_call); | |
333 | _leave(" = %d", ret); | |
334 | return ret; | |
335 | ||
336 | copy_error: | |
337 | _debug("copy error"); | |
338 | release_sock(&rx->sk); | |
339 | rxrpc_put_call(call); | |
340 | if (continue_call) | |
341 | rxrpc_put_call(continue_call); | |
342 | _leave(" = %d", ret); | |
343 | return ret; | |
344 | ||
345 | csum_copy_error: | |
346 | _debug("csum error"); | |
347 | release_sock(&rx->sk); | |
348 | if (continue_call) | |
349 | rxrpc_put_call(continue_call); | |
350 | rxrpc_kill_skb(skb); | |
351 | skb_kill_datagram(&rx->sk, skb, flags); | |
352 | rxrpc_put_call(call); | |
353 | return -EAGAIN; | |
354 | ||
355 | wait_interrupted: | |
356 | ret = sock_intr_errno(timeo); | |
357 | wait_error: | |
358 | finish_wait(rx->sk.sk_sleep, &wait); | |
359 | if (continue_call) | |
360 | rxrpc_put_call(continue_call); | |
361 | if (copied) | |
362 | copied = ret; | |
363 | _leave(" = %d [waitfail %d]", copied, ret); | |
364 | return copied; | |
365 | ||
366 | } | |
651350d1 DH |
367 | |
368 | /** | |
369 | * rxrpc_kernel_data_delivered - Record delivery of data message | |
370 | * @skb: Message holding data | |
371 | * | |
372 | * Record the delivery of a data message. This permits RxRPC to keep its | |
373 | * tracking correct. The socket buffer will be deleted. | |
374 | */ | |
375 | void rxrpc_kernel_data_delivered(struct sk_buff *skb) | |
376 | { | |
377 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
378 | struct rxrpc_call *call = sp->call; | |
379 | ||
380 | ASSERTCMP(ntohl(sp->hdr.seq), >=, call->rx_data_recv); | |
381 | ASSERTCMP(ntohl(sp->hdr.seq), <=, call->rx_data_recv + 1); | |
382 | call->rx_data_recv = ntohl(sp->hdr.seq); | |
383 | ||
384 | ASSERTCMP(ntohl(sp->hdr.seq), >, call->rx_data_eaten); | |
385 | rxrpc_free_skb(skb); | |
386 | } | |
387 | ||
388 | EXPORT_SYMBOL(rxrpc_kernel_data_delivered); | |
389 | ||
390 | /** | |
391 | * rxrpc_kernel_is_data_last - Determine if data message is last one | |
392 | * @skb: Message holding data | |
393 | * | |
394 | * Determine if data message is last one for the parent call. | |
395 | */ | |
396 | bool rxrpc_kernel_is_data_last(struct sk_buff *skb) | |
397 | { | |
398 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
399 | ||
400 | ASSERTCMP(skb->mark, ==, RXRPC_SKB_MARK_DATA); | |
401 | ||
402 | return sp->hdr.flags & RXRPC_LAST_PACKET; | |
403 | } | |
404 | ||
405 | EXPORT_SYMBOL(rxrpc_kernel_is_data_last); | |
406 | ||
407 | /** | |
408 | * rxrpc_kernel_get_abort_code - Get the abort code from an RxRPC abort message | |
409 | * @skb: Message indicating an abort | |
410 | * | |
411 | * Get the abort code from an RxRPC abort message. | |
412 | */ | |
413 | u32 rxrpc_kernel_get_abort_code(struct sk_buff *skb) | |
414 | { | |
415 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
416 | ||
417 | ASSERTCMP(skb->mark, ==, RXRPC_SKB_MARK_REMOTE_ABORT); | |
418 | ||
419 | return sp->call->abort_code; | |
420 | } | |
421 | ||
422 | EXPORT_SYMBOL(rxrpc_kernel_get_abort_code); | |
423 | ||
424 | /** | |
425 | * rxrpc_kernel_get_error - Get the error number from an RxRPC error message | |
426 | * @skb: Message indicating an error | |
427 | * | |
428 | * Get the error number from an RxRPC error message. | |
429 | */ | |
430 | int rxrpc_kernel_get_error_number(struct sk_buff *skb) | |
431 | { | |
432 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
433 | ||
434 | return sp->error; | |
435 | } | |
436 | ||
437 | EXPORT_SYMBOL(rxrpc_kernel_get_error_number); |