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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> | |
bc3b2d7f | 14 | #include <linux/export.h> |
17926a79 DH |
15 | #include <net/sock.h> |
16 | #include <net/af_rxrpc.h> | |
17 | #include "ar-internal.h" | |
18 | ||
19 | /* | |
20 | * removal a call's user ID from the socket tree to make the user ID available | |
21 | * again and so that it won't be seen again in association with that call | |
22 | */ | |
651350d1 | 23 | void rxrpc_remove_user_ID(struct rxrpc_sock *rx, struct rxrpc_call *call) |
17926a79 DH |
24 | { |
25 | _debug("RELEASE CALL %d", call->debug_id); | |
26 | ||
27 | if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { | |
28 | write_lock_bh(&rx->call_lock); | |
29 | rb_erase(&call->sock_node, &call->socket->calls); | |
30 | clear_bit(RXRPC_CALL_HAS_USERID, &call->flags); | |
31 | write_unlock_bh(&rx->call_lock); | |
32 | } | |
33 | ||
34 | read_lock_bh(&call->state_lock); | |
35 | if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && | |
36 | !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) | |
651350d1 | 37 | rxrpc_queue_call(call); |
17926a79 DH |
38 | read_unlock_bh(&call->state_lock); |
39 | } | |
40 | ||
41 | /* | |
42 | * receive a message from an RxRPC socket | |
43 | * - we need to be careful about two or more threads calling recvmsg | |
44 | * simultaneously | |
45 | */ | |
46 | int rxrpc_recvmsg(struct kiocb *iocb, struct socket *sock, | |
47 | struct msghdr *msg, size_t len, int flags) | |
48 | { | |
49 | struct rxrpc_skb_priv *sp; | |
50 | struct rxrpc_call *call = NULL, *continue_call = NULL; | |
51 | struct rxrpc_sock *rx = rxrpc_sk(sock->sk); | |
52 | struct sk_buff *skb; | |
53 | long timeo; | |
54 | int copy, ret, ullen, offset, copied = 0; | |
55 | u32 abort_code; | |
56 | ||
57 | DEFINE_WAIT(wait); | |
58 | ||
59 | _enter(",,,%zu,%d", len, flags); | |
60 | ||
61 | if (flags & (MSG_OOB | MSG_TRUNC)) | |
62 | return -EOPNOTSUPP; | |
63 | ||
64 | ullen = msg->msg_flags & MSG_CMSG_COMPAT ? 4 : sizeof(unsigned long); | |
65 | ||
66 | timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT); | |
67 | msg->msg_flags |= MSG_MORE; | |
68 | ||
69 | lock_sock(&rx->sk); | |
70 | ||
71 | for (;;) { | |
72 | /* return immediately if a client socket has no outstanding | |
73 | * calls */ | |
74 | if (RB_EMPTY_ROOT(&rx->calls)) { | |
75 | if (copied) | |
76 | goto out; | |
77 | if (rx->sk.sk_state != RXRPC_SERVER_LISTENING) { | |
78 | release_sock(&rx->sk); | |
79 | if (continue_call) | |
80 | rxrpc_put_call(continue_call); | |
81 | return -ENODATA; | |
82 | } | |
83 | } | |
84 | ||
85 | /* get the next message on the Rx queue */ | |
86 | skb = skb_peek(&rx->sk.sk_receive_queue); | |
87 | if (!skb) { | |
88 | /* nothing remains on the queue */ | |
89 | if (copied && | |
90 | (msg->msg_flags & MSG_PEEK || timeo == 0)) | |
91 | goto out; | |
92 | ||
93 | /* wait for a message to turn up */ | |
94 | release_sock(&rx->sk); | |
4a4771a5 | 95 | prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait, |
17926a79 DH |
96 | TASK_INTERRUPTIBLE); |
97 | ret = sock_error(&rx->sk); | |
98 | if (ret) | |
99 | goto wait_error; | |
100 | ||
101 | if (skb_queue_empty(&rx->sk.sk_receive_queue)) { | |
102 | if (signal_pending(current)) | |
103 | goto wait_interrupted; | |
104 | timeo = schedule_timeout(timeo); | |
105 | } | |
4a4771a5 | 106 | finish_wait(sk_sleep(&rx->sk), &wait); |
17926a79 DH |
107 | lock_sock(&rx->sk); |
108 | continue; | |
109 | } | |
110 | ||
111 | peek_next_packet: | |
112 | sp = rxrpc_skb(skb); | |
113 | call = sp->call; | |
114 | ASSERT(call != NULL); | |
115 | ||
116 | _debug("next pkt %s", rxrpc_pkts[sp->hdr.type]); | |
117 | ||
118 | /* make sure we wait for the state to be updated in this call */ | |
119 | spin_lock_bh(&call->lock); | |
120 | spin_unlock_bh(&call->lock); | |
121 | ||
122 | if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) { | |
123 | _debug("packet from released call"); | |
124 | if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) | |
125 | BUG(); | |
126 | rxrpc_free_skb(skb); | |
127 | continue; | |
128 | } | |
129 | ||
130 | /* determine whether to continue last data receive */ | |
131 | if (continue_call) { | |
132 | _debug("maybe cont"); | |
133 | if (call != continue_call || | |
134 | skb->mark != RXRPC_SKB_MARK_DATA) { | |
135 | release_sock(&rx->sk); | |
136 | rxrpc_put_call(continue_call); | |
137 | _leave(" = %d [noncont]", copied); | |
138 | return copied; | |
139 | } | |
140 | } | |
141 | ||
142 | rxrpc_get_call(call); | |
143 | ||
144 | /* copy the peer address and timestamp */ | |
145 | if (!continue_call) { | |
f3d33426 HFS |
146 | if (msg->msg_name) { |
147 | size_t len = | |
148 | sizeof(call->conn->trans->peer->srx); | |
1ff82fe0 | 149 | memcpy(msg->msg_name, |
f3d33426 HFS |
150 | &call->conn->trans->peer->srx, len); |
151 | msg->msg_namelen = len; | |
152 | } | |
3b885787 | 153 | sock_recv_ts_and_drops(msg, &rx->sk, skb); |
17926a79 DH |
154 | } |
155 | ||
156 | /* receive the message */ | |
157 | if (skb->mark != RXRPC_SKB_MARK_DATA) | |
158 | goto receive_non_data_message; | |
159 | ||
160 | _debug("recvmsg DATA #%u { %d, %d }", | |
161 | ntohl(sp->hdr.seq), skb->len, sp->offset); | |
162 | ||
163 | if (!continue_call) { | |
164 | /* only set the control data once per recvmsg() */ | |
165 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, | |
166 | ullen, &call->user_call_ID); | |
167 | if (ret < 0) | |
168 | goto copy_error; | |
169 | ASSERT(test_bit(RXRPC_CALL_HAS_USERID, &call->flags)); | |
170 | } | |
171 | ||
172 | ASSERTCMP(ntohl(sp->hdr.seq), >=, call->rx_data_recv); | |
173 | ASSERTCMP(ntohl(sp->hdr.seq), <=, call->rx_data_recv + 1); | |
174 | call->rx_data_recv = ntohl(sp->hdr.seq); | |
175 | ||
176 | ASSERTCMP(ntohl(sp->hdr.seq), >, call->rx_data_eaten); | |
177 | ||
178 | offset = sp->offset; | |
179 | copy = skb->len - offset; | |
180 | if (copy > len - copied) | |
181 | copy = len - copied; | |
182 | ||
183 | if (skb->ip_summed == CHECKSUM_UNNECESSARY) { | |
184 | ret = skb_copy_datagram_iovec(skb, offset, | |
185 | msg->msg_iov, copy); | |
186 | } else { | |
187 | ret = skb_copy_and_csum_datagram_iovec(skb, offset, | |
188 | msg->msg_iov); | |
189 | if (ret == -EINVAL) | |
190 | goto csum_copy_error; | |
191 | } | |
192 | ||
193 | if (ret < 0) | |
194 | goto copy_error; | |
195 | ||
196 | /* handle piecemeal consumption of data packets */ | |
197 | _debug("copied %d+%d", copy, copied); | |
198 | ||
199 | offset += copy; | |
200 | copied += copy; | |
201 | ||
202 | if (!(flags & MSG_PEEK)) | |
203 | sp->offset = offset; | |
204 | ||
205 | if (sp->offset < skb->len) { | |
206 | _debug("buffer full"); | |
207 | ASSERTCMP(copied, ==, len); | |
208 | break; | |
209 | } | |
210 | ||
211 | /* we transferred the whole data packet */ | |
212 | if (sp->hdr.flags & RXRPC_LAST_PACKET) { | |
213 | _debug("last"); | |
214 | if (call->conn->out_clientflag) { | |
215 | /* last byte of reply received */ | |
216 | ret = copied; | |
217 | goto terminal_message; | |
218 | } | |
219 | ||
220 | /* last bit of request received */ | |
221 | if (!(flags & MSG_PEEK)) { | |
222 | _debug("eat packet"); | |
223 | if (skb_dequeue(&rx->sk.sk_receive_queue) != | |
224 | skb) | |
225 | BUG(); | |
226 | rxrpc_free_skb(skb); | |
227 | } | |
228 | msg->msg_flags &= ~MSG_MORE; | |
229 | break; | |
230 | } | |
231 | ||
232 | /* move on to the next data message */ | |
233 | _debug("next"); | |
234 | if (!continue_call) | |
235 | continue_call = sp->call; | |
236 | else | |
237 | rxrpc_put_call(call); | |
238 | call = NULL; | |
239 | ||
240 | if (flags & MSG_PEEK) { | |
241 | _debug("peek next"); | |
242 | skb = skb->next; | |
243 | if (skb == (struct sk_buff *) &rx->sk.sk_receive_queue) | |
244 | break; | |
245 | goto peek_next_packet; | |
246 | } | |
247 | ||
248 | _debug("eat packet"); | |
249 | if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) | |
250 | BUG(); | |
251 | rxrpc_free_skb(skb); | |
252 | } | |
253 | ||
254 | /* end of non-terminal data packet reception for the moment */ | |
255 | _debug("end rcv data"); | |
256 | out: | |
257 | release_sock(&rx->sk); | |
258 | if (call) | |
259 | rxrpc_put_call(call); | |
260 | if (continue_call) | |
261 | rxrpc_put_call(continue_call); | |
262 | _leave(" = %d [data]", copied); | |
263 | return copied; | |
264 | ||
265 | /* handle non-DATA messages such as aborts, incoming connections and | |
266 | * final ACKs */ | |
267 | receive_non_data_message: | |
268 | _debug("non-data"); | |
269 | ||
270 | if (skb->mark == RXRPC_SKB_MARK_NEW_CALL) { | |
271 | _debug("RECV NEW CALL"); | |
272 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NEW_CALL, 0, &abort_code); | |
273 | if (ret < 0) | |
274 | goto copy_error; | |
275 | if (!(flags & MSG_PEEK)) { | |
276 | if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) | |
277 | BUG(); | |
278 | rxrpc_free_skb(skb); | |
279 | } | |
280 | goto out; | |
281 | } | |
282 | ||
283 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, | |
284 | ullen, &call->user_call_ID); | |
285 | if (ret < 0) | |
286 | goto copy_error; | |
287 | ASSERT(test_bit(RXRPC_CALL_HAS_USERID, &call->flags)); | |
288 | ||
289 | switch (skb->mark) { | |
290 | case RXRPC_SKB_MARK_DATA: | |
291 | BUG(); | |
292 | case RXRPC_SKB_MARK_FINAL_ACK: | |
293 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ACK, 0, &abort_code); | |
294 | break; | |
295 | case RXRPC_SKB_MARK_BUSY: | |
296 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_BUSY, 0, &abort_code); | |
297 | break; | |
298 | case RXRPC_SKB_MARK_REMOTE_ABORT: | |
299 | abort_code = call->abort_code; | |
300 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &abort_code); | |
301 | break; | |
302 | case RXRPC_SKB_MARK_NET_ERROR: | |
303 | _debug("RECV NET ERROR %d", sp->error); | |
304 | abort_code = sp->error; | |
305 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NET_ERROR, 4, &abort_code); | |
306 | break; | |
307 | case RXRPC_SKB_MARK_LOCAL_ERROR: | |
308 | _debug("RECV LOCAL ERROR %d", sp->error); | |
309 | abort_code = sp->error; | |
310 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_LOCAL_ERROR, 4, | |
311 | &abort_code); | |
312 | break; | |
313 | default: | |
314 | BUG(); | |
315 | break; | |
316 | } | |
317 | ||
318 | if (ret < 0) | |
319 | goto copy_error; | |
320 | ||
321 | terminal_message: | |
322 | _debug("terminal"); | |
323 | msg->msg_flags &= ~MSG_MORE; | |
324 | msg->msg_flags |= MSG_EOR; | |
325 | ||
326 | if (!(flags & MSG_PEEK)) { | |
327 | _net("free terminal skb %p", skb); | |
328 | if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) | |
329 | BUG(); | |
330 | rxrpc_free_skb(skb); | |
331 | rxrpc_remove_user_ID(rx, call); | |
332 | } | |
333 | ||
334 | release_sock(&rx->sk); | |
335 | rxrpc_put_call(call); | |
336 | if (continue_call) | |
337 | rxrpc_put_call(continue_call); | |
338 | _leave(" = %d", ret); | |
339 | return ret; | |
340 | ||
341 | copy_error: | |
342 | _debug("copy error"); | |
343 | release_sock(&rx->sk); | |
344 | rxrpc_put_call(call); | |
345 | if (continue_call) | |
346 | rxrpc_put_call(continue_call); | |
347 | _leave(" = %d", ret); | |
348 | return ret; | |
349 | ||
350 | csum_copy_error: | |
351 | _debug("csum error"); | |
352 | release_sock(&rx->sk); | |
353 | if (continue_call) | |
354 | rxrpc_put_call(continue_call); | |
355 | rxrpc_kill_skb(skb); | |
356 | skb_kill_datagram(&rx->sk, skb, flags); | |
357 | rxrpc_put_call(call); | |
358 | return -EAGAIN; | |
359 | ||
360 | wait_interrupted: | |
361 | ret = sock_intr_errno(timeo); | |
362 | wait_error: | |
4a4771a5 | 363 | finish_wait(sk_sleep(&rx->sk), &wait); |
17926a79 DH |
364 | if (continue_call) |
365 | rxrpc_put_call(continue_call); | |
366 | if (copied) | |
367 | copied = ret; | |
368 | _leave(" = %d [waitfail %d]", copied, ret); | |
369 | return copied; | |
370 | ||
371 | } | |
651350d1 DH |
372 | |
373 | /** | |
374 | * rxrpc_kernel_data_delivered - Record delivery of data message | |
375 | * @skb: Message holding data | |
376 | * | |
377 | * Record the delivery of a data message. This permits RxRPC to keep its | |
378 | * tracking correct. The socket buffer will be deleted. | |
379 | */ | |
380 | void rxrpc_kernel_data_delivered(struct sk_buff *skb) | |
381 | { | |
382 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
383 | struct rxrpc_call *call = sp->call; | |
384 | ||
385 | ASSERTCMP(ntohl(sp->hdr.seq), >=, call->rx_data_recv); | |
386 | ASSERTCMP(ntohl(sp->hdr.seq), <=, call->rx_data_recv + 1); | |
387 | call->rx_data_recv = ntohl(sp->hdr.seq); | |
388 | ||
389 | ASSERTCMP(ntohl(sp->hdr.seq), >, call->rx_data_eaten); | |
390 | rxrpc_free_skb(skb); | |
391 | } | |
392 | ||
393 | EXPORT_SYMBOL(rxrpc_kernel_data_delivered); | |
394 | ||
395 | /** | |
396 | * rxrpc_kernel_is_data_last - Determine if data message is last one | |
397 | * @skb: Message holding data | |
398 | * | |
399 | * Determine if data message is last one for the parent call. | |
400 | */ | |
401 | bool rxrpc_kernel_is_data_last(struct sk_buff *skb) | |
402 | { | |
403 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
404 | ||
405 | ASSERTCMP(skb->mark, ==, RXRPC_SKB_MARK_DATA); | |
406 | ||
407 | return sp->hdr.flags & RXRPC_LAST_PACKET; | |
408 | } | |
409 | ||
410 | EXPORT_SYMBOL(rxrpc_kernel_is_data_last); | |
411 | ||
412 | /** | |
413 | * rxrpc_kernel_get_abort_code - Get the abort code from an RxRPC abort message | |
414 | * @skb: Message indicating an abort | |
415 | * | |
416 | * Get the abort code from an RxRPC abort message. | |
417 | */ | |
418 | u32 rxrpc_kernel_get_abort_code(struct sk_buff *skb) | |
419 | { | |
420 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
421 | ||
422 | ASSERTCMP(skb->mark, ==, RXRPC_SKB_MARK_REMOTE_ABORT); | |
423 | ||
424 | return sp->call->abort_code; | |
425 | } | |
426 | ||
427 | EXPORT_SYMBOL(rxrpc_kernel_get_abort_code); | |
428 | ||
429 | /** | |
430 | * rxrpc_kernel_get_error - Get the error number from an RxRPC error message | |
431 | * @skb: Message indicating an error | |
432 | * | |
433 | * Get the error number from an RxRPC error message. | |
434 | */ | |
435 | int rxrpc_kernel_get_error_number(struct sk_buff *skb) | |
436 | { | |
437 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
438 | ||
439 | return sp->error; | |
440 | } | |
441 | ||
442 | EXPORT_SYMBOL(rxrpc_kernel_get_error_number); |