Commit | Line | Data |
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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 | ||
9b6d5398 JP |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | ||
17926a79 DH |
14 | #include <linux/net.h> |
15 | #include <linux/skbuff.h> | |
bc3b2d7f | 16 | #include <linux/export.h> |
17926a79 DH |
17 | #include <net/sock.h> |
18 | #include <net/af_rxrpc.h> | |
19 | #include "ar-internal.h" | |
20 | ||
21 | /* | |
22 | * removal a call's user ID from the socket tree to make the user ID available | |
23 | * again and so that it won't be seen again in association with that call | |
24 | */ | |
651350d1 | 25 | void rxrpc_remove_user_ID(struct rxrpc_sock *rx, struct rxrpc_call *call) |
17926a79 DH |
26 | { |
27 | _debug("RELEASE CALL %d", call->debug_id); | |
28 | ||
29 | if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { | |
30 | write_lock_bh(&rx->call_lock); | |
31 | rb_erase(&call->sock_node, &call->socket->calls); | |
32 | clear_bit(RXRPC_CALL_HAS_USERID, &call->flags); | |
33 | write_unlock_bh(&rx->call_lock); | |
34 | } | |
35 | ||
36 | read_lock_bh(&call->state_lock); | |
37 | if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && | |
4c198ad1 | 38 | !test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events)) |
651350d1 | 39 | rxrpc_queue_call(call); |
17926a79 DH |
40 | read_unlock_bh(&call->state_lock); |
41 | } | |
42 | ||
43 | /* | |
44 | * receive a message from an RxRPC socket | |
45 | * - we need to be careful about two or more threads calling recvmsg | |
46 | * simultaneously | |
47 | */ | |
1b784140 YX |
48 | int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, |
49 | int flags) | |
17926a79 DH |
50 | { |
51 | struct rxrpc_skb_priv *sp; | |
52 | struct rxrpc_call *call = NULL, *continue_call = NULL; | |
53 | struct rxrpc_sock *rx = rxrpc_sk(sock->sk); | |
54 | struct sk_buff *skb; | |
55 | long timeo; | |
56 | int copy, ret, ullen, offset, copied = 0; | |
57 | u32 abort_code; | |
58 | ||
59 | DEFINE_WAIT(wait); | |
60 | ||
61 | _enter(",,,%zu,%d", len, flags); | |
62 | ||
63 | if (flags & (MSG_OOB | MSG_TRUNC)) | |
64 | return -EOPNOTSUPP; | |
65 | ||
66 | ullen = msg->msg_flags & MSG_CMSG_COMPAT ? 4 : sizeof(unsigned long); | |
67 | ||
68 | timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT); | |
69 | msg->msg_flags |= MSG_MORE; | |
70 | ||
71 | lock_sock(&rx->sk); | |
72 | ||
73 | for (;;) { | |
74 | /* return immediately if a client socket has no outstanding | |
75 | * calls */ | |
76 | if (RB_EMPTY_ROOT(&rx->calls)) { | |
77 | if (copied) | |
78 | goto out; | |
79 | if (rx->sk.sk_state != RXRPC_SERVER_LISTENING) { | |
80 | release_sock(&rx->sk); | |
81 | if (continue_call) | |
82 | rxrpc_put_call(continue_call); | |
83 | return -ENODATA; | |
84 | } | |
85 | } | |
86 | ||
87 | /* get the next message on the Rx queue */ | |
88 | skb = skb_peek(&rx->sk.sk_receive_queue); | |
89 | if (!skb) { | |
90 | /* nothing remains on the queue */ | |
91 | if (copied && | |
7d985ed1 | 92 | (flags & MSG_PEEK || timeo == 0)) |
17926a79 DH |
93 | goto out; |
94 | ||
95 | /* wait for a message to turn up */ | |
96 | release_sock(&rx->sk); | |
4a4771a5 | 97 | prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait, |
17926a79 DH |
98 | TASK_INTERRUPTIBLE); |
99 | ret = sock_error(&rx->sk); | |
100 | if (ret) | |
101 | goto wait_error; | |
102 | ||
103 | if (skb_queue_empty(&rx->sk.sk_receive_queue)) { | |
104 | if (signal_pending(current)) | |
105 | goto wait_interrupted; | |
106 | timeo = schedule_timeout(timeo); | |
107 | } | |
4a4771a5 | 108 | finish_wait(sk_sleep(&rx->sk), &wait); |
17926a79 DH |
109 | lock_sock(&rx->sk); |
110 | continue; | |
111 | } | |
112 | ||
113 | peek_next_packet: | |
114 | sp = rxrpc_skb(skb); | |
115 | call = sp->call; | |
116 | ASSERT(call != NULL); | |
117 | ||
118 | _debug("next pkt %s", rxrpc_pkts[sp->hdr.type]); | |
119 | ||
120 | /* make sure we wait for the state to be updated in this call */ | |
121 | spin_lock_bh(&call->lock); | |
122 | spin_unlock_bh(&call->lock); | |
123 | ||
124 | if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) { | |
125 | _debug("packet from released call"); | |
126 | if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) | |
127 | BUG(); | |
128 | rxrpc_free_skb(skb); | |
129 | continue; | |
130 | } | |
131 | ||
132 | /* determine whether to continue last data receive */ | |
133 | if (continue_call) { | |
134 | _debug("maybe cont"); | |
135 | if (call != continue_call || | |
136 | skb->mark != RXRPC_SKB_MARK_DATA) { | |
137 | release_sock(&rx->sk); | |
138 | rxrpc_put_call(continue_call); | |
139 | _leave(" = %d [noncont]", copied); | |
140 | return copied; | |
141 | } | |
142 | } | |
143 | ||
144 | rxrpc_get_call(call); | |
145 | ||
146 | /* copy the peer address and timestamp */ | |
147 | if (!continue_call) { | |
f3d33426 HFS |
148 | if (msg->msg_name) { |
149 | size_t len = | |
85f32278 | 150 | sizeof(call->conn->params.peer->srx); |
1ff82fe0 | 151 | memcpy(msg->msg_name, |
85f32278 | 152 | &call->conn->params.peer->srx, len); |
f3d33426 HFS |
153 | msg->msg_namelen = len; |
154 | } | |
2cfdf9fc | 155 | sock_recv_timestamp(msg, &rx->sk, skb); |
17926a79 DH |
156 | } |
157 | ||
158 | /* receive the message */ | |
159 | if (skb->mark != RXRPC_SKB_MARK_DATA) | |
160 | goto receive_non_data_message; | |
161 | ||
162 | _debug("recvmsg DATA #%u { %d, %d }", | |
0d12f8a4 | 163 | sp->hdr.seq, skb->len, sp->offset); |
17926a79 DH |
164 | |
165 | if (!continue_call) { | |
166 | /* only set the control data once per recvmsg() */ | |
167 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, | |
168 | ullen, &call->user_call_ID); | |
169 | if (ret < 0) | |
170 | goto copy_error; | |
171 | ASSERT(test_bit(RXRPC_CALL_HAS_USERID, &call->flags)); | |
172 | } | |
173 | ||
0d12f8a4 DH |
174 | ASSERTCMP(sp->hdr.seq, >=, call->rx_data_recv); |
175 | ASSERTCMP(sp->hdr.seq, <=, call->rx_data_recv + 1); | |
176 | call->rx_data_recv = sp->hdr.seq; | |
17926a79 | 177 | |
0d12f8a4 | 178 | ASSERTCMP(sp->hdr.seq, >, call->rx_data_eaten); |
17926a79 DH |
179 | |
180 | offset = sp->offset; | |
181 | copy = skb->len - offset; | |
182 | if (copy > len - copied) | |
183 | copy = len - copied; | |
184 | ||
51f3d02b | 185 | ret = skb_copy_datagram_msg(skb, offset, msg, copy); |
17926a79 DH |
186 | |
187 | if (ret < 0) | |
188 | goto copy_error; | |
189 | ||
190 | /* handle piecemeal consumption of data packets */ | |
191 | _debug("copied %d+%d", copy, copied); | |
192 | ||
193 | offset += copy; | |
194 | copied += copy; | |
195 | ||
196 | if (!(flags & MSG_PEEK)) | |
197 | sp->offset = offset; | |
198 | ||
199 | if (sp->offset < skb->len) { | |
200 | _debug("buffer full"); | |
201 | ASSERTCMP(copied, ==, len); | |
202 | break; | |
203 | } | |
204 | ||
205 | /* we transferred the whole data packet */ | |
372ee163 DH |
206 | if (!(flags & MSG_PEEK)) |
207 | rxrpc_kernel_data_consumed(call, skb); | |
208 | ||
17926a79 DH |
209 | if (sp->hdr.flags & RXRPC_LAST_PACKET) { |
210 | _debug("last"); | |
19ffa01c | 211 | if (rxrpc_conn_is_client(call->conn)) { |
17926a79 DH |
212 | /* last byte of reply received */ |
213 | ret = copied; | |
214 | goto terminal_message; | |
215 | } | |
216 | ||
217 | /* last bit of request received */ | |
218 | if (!(flags & MSG_PEEK)) { | |
219 | _debug("eat packet"); | |
220 | if (skb_dequeue(&rx->sk.sk_receive_queue) != | |
221 | skb) | |
222 | BUG(); | |
223 | rxrpc_free_skb(skb); | |
224 | } | |
225 | msg->msg_flags &= ~MSG_MORE; | |
226 | break; | |
227 | } | |
228 | ||
229 | /* move on to the next data message */ | |
230 | _debug("next"); | |
231 | if (!continue_call) | |
232 | continue_call = sp->call; | |
233 | else | |
234 | rxrpc_put_call(call); | |
235 | call = NULL; | |
236 | ||
237 | if (flags & MSG_PEEK) { | |
238 | _debug("peek next"); | |
239 | skb = skb->next; | |
240 | if (skb == (struct sk_buff *) &rx->sk.sk_receive_queue) | |
241 | break; | |
242 | goto peek_next_packet; | |
243 | } | |
244 | ||
245 | _debug("eat packet"); | |
246 | if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) | |
247 | BUG(); | |
248 | rxrpc_free_skb(skb); | |
249 | } | |
250 | ||
251 | /* end of non-terminal data packet reception for the moment */ | |
252 | _debug("end rcv data"); | |
253 | out: | |
254 | release_sock(&rx->sk); | |
255 | if (call) | |
256 | rxrpc_put_call(call); | |
257 | if (continue_call) | |
258 | rxrpc_put_call(continue_call); | |
259 | _leave(" = %d [data]", copied); | |
260 | return copied; | |
261 | ||
262 | /* handle non-DATA messages such as aborts, incoming connections and | |
263 | * final ACKs */ | |
264 | receive_non_data_message: | |
265 | _debug("non-data"); | |
266 | ||
267 | if (skb->mark == RXRPC_SKB_MARK_NEW_CALL) { | |
268 | _debug("RECV NEW CALL"); | |
269 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NEW_CALL, 0, &abort_code); | |
270 | if (ret < 0) | |
271 | goto copy_error; | |
272 | if (!(flags & MSG_PEEK)) { | |
273 | if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) | |
274 | BUG(); | |
275 | rxrpc_free_skb(skb); | |
276 | } | |
277 | goto out; | |
278 | } | |
279 | ||
280 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, | |
281 | ullen, &call->user_call_ID); | |
282 | if (ret < 0) | |
283 | goto copy_error; | |
284 | ASSERT(test_bit(RXRPC_CALL_HAS_USERID, &call->flags)); | |
285 | ||
286 | switch (skb->mark) { | |
287 | case RXRPC_SKB_MARK_DATA: | |
288 | BUG(); | |
289 | case RXRPC_SKB_MARK_FINAL_ACK: | |
290 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ACK, 0, &abort_code); | |
291 | break; | |
292 | case RXRPC_SKB_MARK_BUSY: | |
293 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_BUSY, 0, &abort_code); | |
294 | break; | |
295 | case RXRPC_SKB_MARK_REMOTE_ABORT: | |
dc44b3a0 DH |
296 | abort_code = call->remote_abort; |
297 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &abort_code); | |
298 | break; | |
299 | case RXRPC_SKB_MARK_LOCAL_ABORT: | |
300 | abort_code = call->local_abort; | |
17926a79 DH |
301 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &abort_code); |
302 | break; | |
303 | case RXRPC_SKB_MARK_NET_ERROR: | |
304 | _debug("RECV NET ERROR %d", sp->error); | |
305 | abort_code = sp->error; | |
306 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NET_ERROR, 4, &abort_code); | |
307 | break; | |
308 | case RXRPC_SKB_MARK_LOCAL_ERROR: | |
309 | _debug("RECV LOCAL ERROR %d", sp->error); | |
310 | abort_code = sp->error; | |
311 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_LOCAL_ERROR, 4, | |
312 | &abort_code); | |
313 | break; | |
314 | default: | |
9b6d5398 | 315 | pr_err("Unknown packet mark %u\n", skb->mark); |
17926a79 DH |
316 | BUG(); |
317 | break; | |
318 | } | |
319 | ||
320 | if (ret < 0) | |
321 | goto copy_error; | |
322 | ||
323 | terminal_message: | |
324 | _debug("terminal"); | |
325 | msg->msg_flags &= ~MSG_MORE; | |
326 | msg->msg_flags |= MSG_EOR; | |
327 | ||
328 | if (!(flags & MSG_PEEK)) { | |
329 | _net("free terminal skb %p", skb); | |
330 | if (skb_dequeue(&rx->sk.sk_receive_queue) != skb) | |
331 | BUG(); | |
332 | rxrpc_free_skb(skb); | |
333 | rxrpc_remove_user_ID(rx, call); | |
334 | } | |
335 | ||
336 | release_sock(&rx->sk); | |
337 | rxrpc_put_call(call); | |
338 | if (continue_call) | |
339 | rxrpc_put_call(continue_call); | |
340 | _leave(" = %d", ret); | |
341 | return ret; | |
342 | ||
343 | copy_error: | |
344 | _debug("copy error"); | |
345 | release_sock(&rx->sk); | |
346 | rxrpc_put_call(call); | |
347 | if (continue_call) | |
348 | rxrpc_put_call(continue_call); | |
349 | _leave(" = %d", ret); | |
350 | return ret; | |
351 | ||
17926a79 DH |
352 | wait_interrupted: |
353 | ret = sock_intr_errno(timeo); | |
354 | wait_error: | |
4a4771a5 | 355 | finish_wait(sk_sleep(&rx->sk), &wait); |
17926a79 DH |
356 | if (continue_call) |
357 | rxrpc_put_call(continue_call); | |
358 | if (copied) | |
359 | copied = ret; | |
360 | _leave(" = %d [waitfail %d]", copied, ret); | |
361 | return copied; | |
362 | ||
363 | } | |
651350d1 | 364 | |
651350d1 DH |
365 | /** |
366 | * rxrpc_kernel_is_data_last - Determine if data message is last one | |
367 | * @skb: Message holding data | |
368 | * | |
369 | * Determine if data message is last one for the parent call. | |
370 | */ | |
371 | bool rxrpc_kernel_is_data_last(struct sk_buff *skb) | |
372 | { | |
373 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
374 | ||
375 | ASSERTCMP(skb->mark, ==, RXRPC_SKB_MARK_DATA); | |
376 | ||
377 | return sp->hdr.flags & RXRPC_LAST_PACKET; | |
378 | } | |
379 | ||
380 | EXPORT_SYMBOL(rxrpc_kernel_is_data_last); | |
381 | ||
382 | /** | |
383 | * rxrpc_kernel_get_abort_code - Get the abort code from an RxRPC abort message | |
384 | * @skb: Message indicating an abort | |
385 | * | |
386 | * Get the abort code from an RxRPC abort message. | |
387 | */ | |
388 | u32 rxrpc_kernel_get_abort_code(struct sk_buff *skb) | |
389 | { | |
390 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
391 | ||
dc44b3a0 DH |
392 | switch (skb->mark) { |
393 | case RXRPC_SKB_MARK_REMOTE_ABORT: | |
394 | return sp->call->remote_abort; | |
395 | case RXRPC_SKB_MARK_LOCAL_ABORT: | |
396 | return sp->call->local_abort; | |
397 | default: | |
398 | BUG(); | |
399 | } | |
651350d1 DH |
400 | } |
401 | ||
402 | EXPORT_SYMBOL(rxrpc_kernel_get_abort_code); | |
403 | ||
404 | /** | |
405 | * rxrpc_kernel_get_error - Get the error number from an RxRPC error message | |
406 | * @skb: Message indicating an error | |
407 | * | |
408 | * Get the error number from an RxRPC error message. | |
409 | */ | |
410 | int rxrpc_kernel_get_error_number(struct sk_buff *skb) | |
411 | { | |
412 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
413 | ||
414 | return sp->error; | |
415 | } | |
416 | ||
417 | EXPORT_SYMBOL(rxrpc_kernel_get_error_number); |