]>
Commit | Line | Data |
---|---|---|
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> |
174cd4b1 IM |
17 | #include <linux/sched/signal.h> |
18 | ||
17926a79 DH |
19 | #include <net/sock.h> |
20 | #include <net/af_rxrpc.h> | |
21 | #include "ar-internal.h" | |
22 | ||
17926a79 | 23 | /* |
248f219c DH |
24 | * Post a call for attention by the socket or kernel service. Further |
25 | * notifications are suppressed by putting recvmsg_link on a dummy queue. | |
17926a79 | 26 | */ |
248f219c | 27 | void rxrpc_notify_socket(struct rxrpc_call *call) |
17926a79 | 28 | { |
248f219c DH |
29 | struct rxrpc_sock *rx; |
30 | struct sock *sk; | |
17926a79 | 31 | |
248f219c | 32 | _enter("%d", call->debug_id); |
17926a79 | 33 | |
248f219c DH |
34 | if (!list_empty(&call->recvmsg_link)) |
35 | return; | |
36 | ||
37 | rcu_read_lock(); | |
38 | ||
39 | rx = rcu_dereference(call->socket); | |
40 | sk = &rx->sk; | |
41 | if (rx && sk->sk_state < RXRPC_CLOSE) { | |
42 | if (call->notify_rx) { | |
20acbd9a | 43 | spin_lock_bh(&call->notify_lock); |
248f219c | 44 | call->notify_rx(sk, call, call->user_call_ID); |
20acbd9a | 45 | spin_unlock_bh(&call->notify_lock); |
248f219c DH |
46 | } else { |
47 | write_lock_bh(&rx->recvmsg_lock); | |
48 | if (list_empty(&call->recvmsg_link)) { | |
49 | rxrpc_get_call(call, rxrpc_call_got); | |
50 | list_add_tail(&call->recvmsg_link, &rx->recvmsg_q); | |
51 | } | |
52 | write_unlock_bh(&rx->recvmsg_lock); | |
17926a79 | 53 | |
248f219c DH |
54 | if (!sock_flag(sk, SOCK_DEAD)) { |
55 | _debug("call %ps", sk->sk_data_ready); | |
56 | sk->sk_data_ready(sk); | |
57 | } | |
58 | } | |
59 | } | |
17926a79 | 60 | |
248f219c DH |
61 | rcu_read_unlock(); |
62 | _leave(""); | |
63 | } | |
17926a79 | 64 | |
248f219c DH |
65 | /* |
66 | * Pass a call terminating message to userspace. | |
67 | */ | |
68 | static int rxrpc_recvmsg_term(struct rxrpc_call *call, struct msghdr *msg) | |
69 | { | |
70 | u32 tmp = 0; | |
71 | int ret; | |
17926a79 | 72 | |
248f219c DH |
73 | switch (call->completion) { |
74 | case RXRPC_CALL_SUCCEEDED: | |
75 | ret = 0; | |
76 | if (rxrpc_is_service_call(call)) | |
77 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ACK, 0, &tmp); | |
78 | break; | |
79 | case RXRPC_CALL_REMOTELY_ABORTED: | |
80 | tmp = call->abort_code; | |
81 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp); | |
82 | break; | |
83 | case RXRPC_CALL_LOCALLY_ABORTED: | |
84 | tmp = call->abort_code; | |
85 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp); | |
86 | break; | |
87 | case RXRPC_CALL_NETWORK_ERROR: | |
3a92789a | 88 | tmp = -call->error; |
248f219c DH |
89 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NET_ERROR, 4, &tmp); |
90 | break; | |
91 | case RXRPC_CALL_LOCAL_ERROR: | |
3a92789a | 92 | tmp = -call->error; |
248f219c DH |
93 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_LOCAL_ERROR, 4, &tmp); |
94 | break; | |
95 | default: | |
96 | pr_err("Invalid terminal call state %u\n", call->state); | |
97 | BUG(); | |
98 | break; | |
99 | } | |
17926a79 | 100 | |
84997905 DH |
101 | trace_rxrpc_recvmsg(call, rxrpc_recvmsg_terminal, call->rx_hard_ack, |
102 | call->rx_pkt_offset, call->rx_pkt_len, ret); | |
248f219c DH |
103 | return ret; |
104 | } | |
17926a79 | 105 | |
248f219c DH |
106 | /* |
107 | * Pass back notification of a new call. The call is added to the | |
108 | * to-be-accepted list. This means that the next call to be accepted might not | |
109 | * be the last call seen awaiting acceptance, but unless we leave this on the | |
110 | * front of the queue and block all other messages until someone gives us a | |
111 | * user_ID for it, there's not a lot we can do. | |
112 | */ | |
113 | static int rxrpc_recvmsg_new_call(struct rxrpc_sock *rx, | |
114 | struct rxrpc_call *call, | |
115 | struct msghdr *msg, int flags) | |
116 | { | |
117 | int tmp = 0, ret; | |
17926a79 | 118 | |
248f219c | 119 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NEW_CALL, 0, &tmp); |
17926a79 | 120 | |
248f219c DH |
121 | if (ret == 0 && !(flags & MSG_PEEK)) { |
122 | _debug("to be accepted"); | |
123 | write_lock_bh(&rx->recvmsg_lock); | |
124 | list_del_init(&call->recvmsg_link); | |
125 | write_unlock_bh(&rx->recvmsg_lock); | |
17926a79 | 126 | |
3432a757 | 127 | rxrpc_get_call(call, rxrpc_call_got); |
248f219c DH |
128 | write_lock(&rx->call_lock); |
129 | list_add_tail(&call->accept_link, &rx->to_be_accepted); | |
130 | write_unlock(&rx->call_lock); | |
131 | } | |
17926a79 | 132 | |
84997905 | 133 | trace_rxrpc_recvmsg(call, rxrpc_recvmsg_to_be_accepted, 1, 0, 0, ret); |
248f219c DH |
134 | return ret; |
135 | } | |
17926a79 | 136 | |
248f219c DH |
137 | /* |
138 | * End the packet reception phase. | |
139 | */ | |
b69d94d7 | 140 | static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial) |
248f219c DH |
141 | { |
142 | _enter("%d,%s", call->debug_id, rxrpc_call_states[call->state]); | |
17926a79 | 143 | |
58dc63c9 | 144 | trace_rxrpc_receive(call, rxrpc_receive_end, 0, call->rx_top); |
816c9fce DH |
145 | ASSERTCMP(call->rx_hard_ack, ==, call->rx_top); |
146 | ||
248f219c | 147 | if (call->state == RXRPC_CALL_CLIENT_RECV_REPLY) { |
b69d94d7 | 148 | rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, serial, true, false, |
9c7ad434 | 149 | rxrpc_propose_ack_terminal_ack); |
a5af7e1f | 150 | rxrpc_send_ack_packet(call, false); |
248f219c | 151 | } |
17926a79 | 152 | |
248f219c | 153 | write_lock_bh(&call->state_lock); |
17926a79 | 154 | |
248f219c DH |
155 | switch (call->state) { |
156 | case RXRPC_CALL_CLIENT_RECV_REPLY: | |
157 | __rxrpc_call_completed(call); | |
9749fd2b | 158 | write_unlock_bh(&call->state_lock); |
248f219c | 159 | break; |
17926a79 | 160 | |
248f219c | 161 | case RXRPC_CALL_SERVER_RECV_REQUEST: |
71f3ca40 | 162 | call->tx_phase = true; |
248f219c | 163 | call->state = RXRPC_CALL_SERVER_ACK_REQUEST; |
9749fd2b DH |
164 | call->ack_at = call->expire_at; |
165 | write_unlock_bh(&call->state_lock); | |
166 | rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, 0, serial, false, true, | |
167 | rxrpc_propose_ack_processing_op); | |
248f219c DH |
168 | break; |
169 | default: | |
9749fd2b | 170 | write_unlock_bh(&call->state_lock); |
248f219c DH |
171 | break; |
172 | } | |
248f219c | 173 | } |
17926a79 | 174 | |
248f219c DH |
175 | /* |
176 | * Discard a packet we've used up and advance the Rx window by one. | |
177 | */ | |
178 | static void rxrpc_rotate_rx_window(struct rxrpc_call *call) | |
179 | { | |
816c9fce | 180 | struct rxrpc_skb_priv *sp; |
248f219c | 181 | struct sk_buff *skb; |
58dc63c9 | 182 | rxrpc_serial_t serial; |
248f219c | 183 | rxrpc_seq_t hard_ack, top; |
816c9fce | 184 | u8 flags; |
248f219c DH |
185 | int ix; |
186 | ||
187 | _enter("%d", call->debug_id); | |
188 | ||
189 | hard_ack = call->rx_hard_ack; | |
190 | top = smp_load_acquire(&call->rx_top); | |
191 | ASSERT(before(hard_ack, top)); | |
192 | ||
193 | hard_ack++; | |
194 | ix = hard_ack & RXRPC_RXTX_BUFF_MASK; | |
195 | skb = call->rxtx_buffer[ix]; | |
71f3ca40 | 196 | rxrpc_see_skb(skb, rxrpc_skb_rx_rotated); |
816c9fce DH |
197 | sp = rxrpc_skb(skb); |
198 | flags = sp->hdr.flags; | |
58dc63c9 DH |
199 | serial = sp->hdr.serial; |
200 | if (call->rxtx_annotations[ix] & RXRPC_RX_ANNO_JUMBO) | |
201 | serial += (call->rxtx_annotations[ix] & RXRPC_RX_ANNO_JUMBO) - 1; | |
202 | ||
248f219c DH |
203 | call->rxtx_buffer[ix] = NULL; |
204 | call->rxtx_annotations[ix] = 0; | |
205 | /* Barrier against rxrpc_input_data(). */ | |
206 | smp_store_release(&call->rx_hard_ack, hard_ack); | |
17926a79 | 207 | |
71f3ca40 | 208 | rxrpc_free_skb(skb, rxrpc_skb_rx_freed); |
17926a79 | 209 | |
816c9fce | 210 | _debug("%u,%u,%02x", hard_ack, top, flags); |
58dc63c9 | 211 | trace_rxrpc_receive(call, rxrpc_receive_rotate, serial, hard_ack); |
805b21b9 | 212 | if (flags & RXRPC_LAST_PACKET) { |
b69d94d7 | 213 | rxrpc_end_rx_phase(call, serial); |
805b21b9 DH |
214 | } else { |
215 | /* Check to see if there's an ACK that needs sending. */ | |
216 | if (after_eq(hard_ack, call->ackr_consumed + 2) || | |
217 | after_eq(top, call->ackr_seen + 2) || | |
218 | (hard_ack == top && after(hard_ack, call->ackr_consumed))) | |
219 | rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, 0, serial, | |
220 | true, false, | |
221 | rxrpc_propose_ack_rotate_rx); | |
222 | if (call->ackr_reason) | |
a5af7e1f | 223 | rxrpc_send_ack_packet(call, false); |
805b21b9 | 224 | } |
248f219c DH |
225 | } |
226 | ||
227 | /* | |
228 | * Decrypt and verify a (sub)packet. The packet's length may be changed due to | |
229 | * padding, but if this is the case, the packet length will be resident in the | |
230 | * socket buffer. Note that we can't modify the master skb info as the skb may | |
231 | * be the home to multiple subpackets. | |
232 | */ | |
233 | static int rxrpc_verify_packet(struct rxrpc_call *call, struct sk_buff *skb, | |
234 | u8 annotation, | |
235 | unsigned int offset, unsigned int len) | |
236 | { | |
237 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
238 | rxrpc_seq_t seq = sp->hdr.seq; | |
239 | u16 cksum = sp->hdr.cksum; | |
240 | ||
241 | _enter(""); | |
242 | ||
243 | /* For all but the head jumbo subpacket, the security checksum is in a | |
244 | * jumbo header immediately prior to the data. | |
245 | */ | |
246 | if ((annotation & RXRPC_RX_ANNO_JUMBO) > 1) { | |
247 | __be16 tmp; | |
248 | if (skb_copy_bits(skb, offset - 2, &tmp, 2) < 0) | |
249 | BUG(); | |
250 | cksum = ntohs(tmp); | |
251 | seq += (annotation & RXRPC_RX_ANNO_JUMBO) - 1; | |
252 | } | |
253 | ||
254 | return call->conn->security->verify_packet(call, skb, offset, len, | |
255 | seq, cksum); | |
256 | } | |
257 | ||
258 | /* | |
259 | * Locate the data within a packet. This is complicated by: | |
260 | * | |
261 | * (1) An skb may contain a jumbo packet - so we have to find the appropriate | |
262 | * subpacket. | |
263 | * | |
264 | * (2) The (sub)packets may be encrypted and, if so, the encrypted portion | |
265 | * contains an extra header which includes the true length of the data, | |
266 | * excluding any encrypted padding. | |
267 | */ | |
268 | static int rxrpc_locate_data(struct rxrpc_call *call, struct sk_buff *skb, | |
269 | u8 *_annotation, | |
270 | unsigned int *_offset, unsigned int *_len) | |
271 | { | |
775e5b71 | 272 | unsigned int offset = sizeof(struct rxrpc_wire_header); |
248f219c DH |
273 | unsigned int len = *_len; |
274 | int ret; | |
275 | u8 annotation = *_annotation; | |
276 | ||
248f219c | 277 | /* Locate the subpacket */ |
775e5b71 | 278 | len = skb->len - offset; |
248f219c DH |
279 | if ((annotation & RXRPC_RX_ANNO_JUMBO) > 0) { |
280 | offset += (((annotation & RXRPC_RX_ANNO_JUMBO) - 1) * | |
281 | RXRPC_JUMBO_SUBPKTLEN); | |
282 | len = (annotation & RXRPC_RX_ANNO_JLAST) ? | |
283 | skb->len - offset : RXRPC_JUMBO_SUBPKTLEN; | |
284 | } | |
285 | ||
286 | if (!(annotation & RXRPC_RX_ANNO_VERIFIED)) { | |
287 | ret = rxrpc_verify_packet(call, skb, annotation, offset, len); | |
17926a79 | 288 | if (ret < 0) |
248f219c DH |
289 | return ret; |
290 | *_annotation |= RXRPC_RX_ANNO_VERIFIED; | |
291 | } | |
17926a79 | 292 | |
248f219c DH |
293 | *_offset = offset; |
294 | *_len = len; | |
295 | call->conn->security->locate_data(call, skb, _offset, _len); | |
296 | return 0; | |
297 | } | |
17926a79 | 298 | |
248f219c DH |
299 | /* |
300 | * Deliver messages to a call. This keeps processing packets until the buffer | |
301 | * is filled and we find either more DATA (returns 0) or the end of the DATA | |
302 | * (returns 1). If more packets are required, it returns -EAGAIN. | |
303 | */ | |
304 | static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call, | |
305 | struct msghdr *msg, struct iov_iter *iter, | |
306 | size_t len, int flags, size_t *_offset) | |
307 | { | |
308 | struct rxrpc_skb_priv *sp; | |
309 | struct sk_buff *skb; | |
310 | rxrpc_seq_t hard_ack, top, seq; | |
311 | size_t remain; | |
312 | bool last; | |
313 | unsigned int rx_pkt_offset, rx_pkt_len; | |
816c9fce | 314 | int ix, copy, ret = -EAGAIN, ret2; |
248f219c | 315 | |
248f219c DH |
316 | rx_pkt_offset = call->rx_pkt_offset; |
317 | rx_pkt_len = call->rx_pkt_len; | |
318 | ||
816c9fce DH |
319 | if (call->state >= RXRPC_CALL_SERVER_ACK_REQUEST) { |
320 | seq = call->rx_hard_ack; | |
321 | ret = 1; | |
322 | goto done; | |
323 | } | |
324 | ||
248f219c DH |
325 | /* Barriers against rxrpc_input_data(). */ |
326 | hard_ack = call->rx_hard_ack; | |
d7e15835 DH |
327 | seq = hard_ack + 1; |
328 | while (top = smp_load_acquire(&call->rx_top), | |
329 | before_eq(seq, top) | |
330 | ) { | |
248f219c DH |
331 | ix = seq & RXRPC_RXTX_BUFF_MASK; |
332 | skb = call->rxtx_buffer[ix]; | |
84997905 DH |
333 | if (!skb) { |
334 | trace_rxrpc_recvmsg(call, rxrpc_recvmsg_hole, seq, | |
335 | rx_pkt_offset, rx_pkt_len, 0); | |
248f219c | 336 | break; |
84997905 | 337 | } |
248f219c | 338 | smp_rmb(); |
71f3ca40 | 339 | rxrpc_see_skb(skb, rxrpc_skb_rx_seen); |
248f219c | 340 | sp = rxrpc_skb(skb); |
17926a79 | 341 | |
58dc63c9 DH |
342 | if (!(flags & MSG_PEEK)) |
343 | trace_rxrpc_receive(call, rxrpc_receive_front, | |
344 | sp->hdr.serial, seq); | |
345 | ||
248f219c DH |
346 | if (msg) |
347 | sock_recv_timestamp(msg, sock->sk, skb); | |
348 | ||
2e2ea51d | 349 | if (rx_pkt_offset == 0) { |
816c9fce DH |
350 | ret2 = rxrpc_locate_data(call, skb, |
351 | &call->rxtx_annotations[ix], | |
352 | &rx_pkt_offset, &rx_pkt_len); | |
84997905 DH |
353 | trace_rxrpc_recvmsg(call, rxrpc_recvmsg_next, seq, |
354 | rx_pkt_offset, rx_pkt_len, ret2); | |
816c9fce DH |
355 | if (ret2 < 0) { |
356 | ret = ret2; | |
2e2ea51d | 357 | goto out; |
816c9fce | 358 | } |
84997905 DH |
359 | } else { |
360 | trace_rxrpc_recvmsg(call, rxrpc_recvmsg_cont, seq, | |
361 | rx_pkt_offset, rx_pkt_len, 0); | |
2e2ea51d | 362 | } |
248f219c DH |
363 | |
364 | /* We have to handle short, empty and used-up DATA packets. */ | |
365 | remain = len - *_offset; | |
366 | copy = rx_pkt_len; | |
367 | if (copy > remain) | |
368 | copy = remain; | |
369 | if (copy > 0) { | |
816c9fce DH |
370 | ret2 = skb_copy_datagram_iter(skb, rx_pkt_offset, iter, |
371 | copy); | |
372 | if (ret2 < 0) { | |
373 | ret = ret2; | |
248f219c | 374 | goto out; |
816c9fce | 375 | } |
248f219c DH |
376 | |
377 | /* handle piecemeal consumption of data packets */ | |
248f219c DH |
378 | rx_pkt_offset += copy; |
379 | rx_pkt_len -= copy; | |
380 | *_offset += copy; | |
381 | } | |
17926a79 | 382 | |
248f219c | 383 | if (rx_pkt_len > 0) { |
84997905 DH |
384 | trace_rxrpc_recvmsg(call, rxrpc_recvmsg_full, seq, |
385 | rx_pkt_offset, rx_pkt_len, 0); | |
248f219c | 386 | ASSERTCMP(*_offset, ==, len); |
816c9fce | 387 | ret = 0; |
17926a79 DH |
388 | break; |
389 | } | |
390 | ||
248f219c DH |
391 | /* The whole packet has been transferred. */ |
392 | last = sp->hdr.flags & RXRPC_LAST_PACKET; | |
372ee163 | 393 | if (!(flags & MSG_PEEK)) |
248f219c DH |
394 | rxrpc_rotate_rx_window(call); |
395 | rx_pkt_offset = 0; | |
396 | rx_pkt_len = 0; | |
17926a79 | 397 | |
816c9fce DH |
398 | if (last) { |
399 | ASSERTCMP(seq, ==, READ_ONCE(call->rx_top)); | |
248f219c | 400 | ret = 1; |
816c9fce DH |
401 | goto out; |
402 | } | |
d7e15835 DH |
403 | |
404 | seq++; | |
248f219c | 405 | } |
816c9fce | 406 | |
248f219c DH |
407 | out: |
408 | if (!(flags & MSG_PEEK)) { | |
409 | call->rx_pkt_offset = rx_pkt_offset; | |
410 | call->rx_pkt_len = rx_pkt_len; | |
411 | } | |
816c9fce | 412 | done: |
84997905 DH |
413 | trace_rxrpc_recvmsg(call, rxrpc_recvmsg_data_return, seq, |
414 | rx_pkt_offset, rx_pkt_len, ret); | |
248f219c DH |
415 | return ret; |
416 | } | |
17926a79 | 417 | |
248f219c DH |
418 | /* |
419 | * Receive a message from an RxRPC socket | |
420 | * - we need to be careful about two or more threads calling recvmsg | |
421 | * simultaneously | |
422 | */ | |
423 | int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, | |
424 | int flags) | |
425 | { | |
426 | struct rxrpc_call *call; | |
427 | struct rxrpc_sock *rx = rxrpc_sk(sock->sk); | |
428 | struct list_head *l; | |
429 | size_t copied = 0; | |
430 | long timeo; | |
431 | int ret; | |
432 | ||
433 | DEFINE_WAIT(wait); | |
434 | ||
84997905 | 435 | trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_enter, 0, 0, 0, 0); |
248f219c DH |
436 | |
437 | if (flags & (MSG_OOB | MSG_TRUNC)) | |
438 | return -EOPNOTSUPP; | |
439 | ||
440 | timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT); | |
441 | ||
442 | try_again: | |
443 | lock_sock(&rx->sk); | |
444 | ||
445 | /* Return immediately if a client socket has no outstanding calls */ | |
446 | if (RB_EMPTY_ROOT(&rx->calls) && | |
447 | list_empty(&rx->recvmsg_q) && | |
448 | rx->sk.sk_state != RXRPC_SERVER_LISTENING) { | |
449 | release_sock(&rx->sk); | |
450 | return -ENODATA; | |
17926a79 DH |
451 | } |
452 | ||
248f219c DH |
453 | if (list_empty(&rx->recvmsg_q)) { |
454 | ret = -EWOULDBLOCK; | |
84997905 DH |
455 | if (timeo == 0) { |
456 | call = NULL; | |
248f219c | 457 | goto error_no_call; |
84997905 | 458 | } |
248f219c DH |
459 | |
460 | release_sock(&rx->sk); | |
461 | ||
462 | /* Wait for something to happen */ | |
463 | prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait, | |
464 | TASK_INTERRUPTIBLE); | |
465 | ret = sock_error(&rx->sk); | |
466 | if (ret) | |
467 | goto wait_error; | |
468 | ||
469 | if (list_empty(&rx->recvmsg_q)) { | |
470 | if (signal_pending(current)) | |
471 | goto wait_interrupted; | |
84997905 DH |
472 | trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_wait, |
473 | 0, 0, 0, 0); | |
248f219c | 474 | timeo = schedule_timeout(timeo); |
17926a79 | 475 | } |
248f219c DH |
476 | finish_wait(sk_sleep(&rx->sk), &wait); |
477 | goto try_again; | |
17926a79 DH |
478 | } |
479 | ||
248f219c DH |
480 | /* Find the next call and dequeue it if we're not just peeking. If we |
481 | * do dequeue it, that comes with a ref that we will need to release. | |
482 | */ | |
483 | write_lock_bh(&rx->recvmsg_lock); | |
484 | l = rx->recvmsg_q.next; | |
485 | call = list_entry(l, struct rxrpc_call, recvmsg_link); | |
486 | if (!(flags & MSG_PEEK)) | |
487 | list_del_init(&call->recvmsg_link); | |
488 | else | |
489 | rxrpc_get_call(call, rxrpc_call_got); | |
490 | write_unlock_bh(&rx->recvmsg_lock); | |
17926a79 | 491 | |
84997905 | 492 | trace_rxrpc_recvmsg(call, rxrpc_recvmsg_dequeue, 0, 0, 0, 0); |
248f219c | 493 | |
540b1c48 DH |
494 | /* We're going to drop the socket lock, so we need to lock the call |
495 | * against interference by sendmsg. | |
496 | */ | |
497 | if (!mutex_trylock(&call->user_mutex)) { | |
498 | ret = -EWOULDBLOCK; | |
499 | if (flags & MSG_DONTWAIT) | |
500 | goto error_requeue_call; | |
501 | ret = -ERESTARTSYS; | |
502 | if (mutex_lock_interruptible(&call->user_mutex) < 0) | |
503 | goto error_requeue_call; | |
504 | } | |
505 | ||
506 | release_sock(&rx->sk); | |
507 | ||
248f219c | 508 | if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) |
17926a79 | 509 | BUG(); |
248f219c DH |
510 | |
511 | if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { | |
512 | if (flags & MSG_CMSG_COMPAT) { | |
513 | unsigned int id32 = call->user_call_ID; | |
514 | ||
515 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, | |
516 | sizeof(unsigned int), &id32); | |
517 | } else { | |
518 | ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, | |
519 | sizeof(unsigned long), | |
520 | &call->user_call_ID); | |
f5c17aae | 521 | } |
248f219c | 522 | if (ret < 0) |
540b1c48 | 523 | goto error_unlock_call; |
248f219c DH |
524 | } |
525 | ||
526 | if (msg->msg_name) { | |
68d6d1ae DH |
527 | struct sockaddr_rxrpc *srx = msg->msg_name; |
528 | size_t len = sizeof(call->peer->srx); | |
529 | ||
530 | memcpy(msg->msg_name, &call->peer->srx, len); | |
531 | srx->srx_service = call->service_id; | |
248f219c DH |
532 | msg->msg_namelen = len; |
533 | } | |
534 | ||
146d8fef | 535 | switch (READ_ONCE(call->state)) { |
248f219c DH |
536 | case RXRPC_CALL_SERVER_ACCEPTING: |
537 | ret = rxrpc_recvmsg_new_call(rx, call, msg, flags); | |
17926a79 | 538 | break; |
248f219c DH |
539 | case RXRPC_CALL_CLIENT_RECV_REPLY: |
540 | case RXRPC_CALL_SERVER_RECV_REQUEST: | |
541 | case RXRPC_CALL_SERVER_ACK_REQUEST: | |
542 | ret = rxrpc_recvmsg_data(sock, call, msg, &msg->msg_iter, len, | |
543 | flags, &copied); | |
544 | if (ret == -EAGAIN) | |
545 | ret = 0; | |
33b603fd DH |
546 | |
547 | if (after(call->rx_top, call->rx_hard_ack) && | |
548 | call->rxtx_buffer[(call->rx_hard_ack + 1) & RXRPC_RXTX_BUFF_MASK]) | |
549 | rxrpc_notify_socket(call); | |
17926a79 DH |
550 | break; |
551 | default: | |
248f219c | 552 | ret = 0; |
17926a79 DH |
553 | break; |
554 | } | |
555 | ||
556 | if (ret < 0) | |
540b1c48 | 557 | goto error_unlock_call; |
17926a79 | 558 | |
248f219c DH |
559 | if (call->state == RXRPC_CALL_COMPLETE) { |
560 | ret = rxrpc_recvmsg_term(call, msg); | |
561 | if (ret < 0) | |
540b1c48 | 562 | goto error_unlock_call; |
248f219c DH |
563 | if (!(flags & MSG_PEEK)) |
564 | rxrpc_release_call(rx, call); | |
565 | msg->msg_flags |= MSG_EOR; | |
566 | ret = 1; | |
17926a79 DH |
567 | } |
568 | ||
248f219c DH |
569 | if (ret == 0) |
570 | msg->msg_flags |= MSG_MORE; | |
571 | else | |
572 | msg->msg_flags &= ~MSG_MORE; | |
573 | ret = copied; | |
17926a79 | 574 | |
540b1c48 DH |
575 | error_unlock_call: |
576 | mutex_unlock(&call->user_mutex); | |
fff72429 | 577 | rxrpc_put_call(call, rxrpc_call_put); |
540b1c48 DH |
578 | trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, 0, 0, 0, ret); |
579 | return ret; | |
580 | ||
581 | error_requeue_call: | |
582 | if (!(flags & MSG_PEEK)) { | |
583 | write_lock_bh(&rx->recvmsg_lock); | |
584 | list_add(&call->recvmsg_link, &rx->recvmsg_q); | |
585 | write_unlock_bh(&rx->recvmsg_lock); | |
586 | trace_rxrpc_recvmsg(call, rxrpc_recvmsg_requeue, 0, 0, 0, 0); | |
587 | } else { | |
588 | rxrpc_put_call(call, rxrpc_call_put); | |
589 | } | |
248f219c DH |
590 | error_no_call: |
591 | release_sock(&rx->sk); | |
84997905 | 592 | trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, 0, 0, 0, ret); |
17926a79 DH |
593 | return ret; |
594 | ||
17926a79 DH |
595 | wait_interrupted: |
596 | ret = sock_intr_errno(timeo); | |
597 | wait_error: | |
4a4771a5 | 598 | finish_wait(sk_sleep(&rx->sk), &wait); |
84997905 DH |
599 | call = NULL; |
600 | goto error_no_call; | |
d001648e | 601 | } |
651350d1 DH |
602 | |
603 | /** | |
d001648e DH |
604 | * rxrpc_kernel_recv_data - Allow a kernel service to receive data/info |
605 | * @sock: The socket that the call exists on | |
606 | * @call: The call to send data through | |
607 | * @buf: The buffer to receive into | |
608 | * @size: The size of the buffer, including data already read | |
609 | * @_offset: The running offset into the buffer. | |
610 | * @want_more: True if more data is expected to be read | |
611 | * @_abort: Where the abort code is stored if -ECONNABORTED is returned | |
a68f4a27 | 612 | * @_service: Where to store the actual service ID (may be upgraded) |
d001648e DH |
613 | * |
614 | * Allow a kernel service to receive data and pick up information about the | |
615 | * state of a call. Returns 0 if got what was asked for and there's more | |
616 | * available, 1 if we got what was asked for and we're at the end of the data | |
617 | * and -EAGAIN if we need more data. | |
618 | * | |
619 | * Note that we may return -EAGAIN to drain empty packets at the end of the | |
620 | * data, even if we've already copied over the requested data. | |
651350d1 | 621 | * |
d001648e DH |
622 | * This function adds the amount it transfers to *_offset, so this should be |
623 | * precleared as appropriate. Note that the amount remaining in the buffer is | |
624 | * taken to be size - *_offset. | |
625 | * | |
626 | * *_abort should also be initialised to 0. | |
651350d1 | 627 | */ |
d001648e DH |
628 | int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call, |
629 | void *buf, size_t size, size_t *_offset, | |
a68f4a27 | 630 | bool want_more, u32 *_abort, u16 *_service) |
651350d1 | 631 | { |
d001648e DH |
632 | struct iov_iter iter; |
633 | struct kvec iov; | |
634 | int ret; | |
651350d1 | 635 | |
248f219c DH |
636 | _enter("{%d,%s},%zu/%zu,%d", |
637 | call->debug_id, rxrpc_call_states[call->state], | |
638 | *_offset, size, want_more); | |
d001648e DH |
639 | |
640 | ASSERTCMP(*_offset, <=, size); | |
641 | ASSERTCMP(call->state, !=, RXRPC_CALL_SERVER_ACCEPTING); | |
651350d1 | 642 | |
d001648e DH |
643 | iov.iov_base = buf + *_offset; |
644 | iov.iov_len = size - *_offset; | |
645 | iov_iter_kvec(&iter, ITER_KVEC | READ, &iov, 1, size - *_offset); | |
646 | ||
540b1c48 | 647 | mutex_lock(&call->user_mutex); |
d001648e | 648 | |
146d8fef | 649 | switch (READ_ONCE(call->state)) { |
d001648e DH |
650 | case RXRPC_CALL_CLIENT_RECV_REPLY: |
651 | case RXRPC_CALL_SERVER_RECV_REQUEST: | |
652 | case RXRPC_CALL_SERVER_ACK_REQUEST: | |
248f219c DH |
653 | ret = rxrpc_recvmsg_data(sock, call, NULL, &iter, size, 0, |
654 | _offset); | |
d001648e DH |
655 | if (ret < 0) |
656 | goto out; | |
657 | ||
658 | /* We can only reach here with a partially full buffer if we | |
659 | * have reached the end of the data. We must otherwise have a | |
660 | * full buffer or have been given -EAGAIN. | |
661 | */ | |
662 | if (ret == 1) { | |
663 | if (*_offset < size) | |
664 | goto short_data; | |
665 | if (!want_more) | |
666 | goto read_phase_complete; | |
667 | ret = 0; | |
668 | goto out; | |
669 | } | |
670 | ||
671 | if (!want_more) | |
672 | goto excess_data; | |
673 | goto out; | |
674 | ||
675 | case RXRPC_CALL_COMPLETE: | |
676 | goto call_complete; | |
677 | ||
678 | default: | |
d001648e DH |
679 | ret = -EINPROGRESS; |
680 | goto out; | |
681 | } | |
682 | ||
683 | read_phase_complete: | |
684 | ret = 1; | |
685 | out: | |
a68f4a27 DH |
686 | if (_service) |
687 | *_service = call->service_id; | |
540b1c48 | 688 | mutex_unlock(&call->user_mutex); |
d001648e DH |
689 | _leave(" = %d [%zu,%d]", ret, *_offset, *_abort); |
690 | return ret; | |
691 | ||
692 | short_data: | |
fb46f6ee | 693 | trace_rxrpc_rx_eproto(call, 0, tracepoint_string("short_data")); |
d001648e DH |
694 | ret = -EBADMSG; |
695 | goto out; | |
696 | excess_data: | |
fb46f6ee | 697 | trace_rxrpc_rx_eproto(call, 0, tracepoint_string("excess_data")); |
d001648e DH |
698 | ret = -EMSGSIZE; |
699 | goto out; | |
700 | call_complete: | |
701 | *_abort = call->abort_code; | |
3a92789a | 702 | ret = call->error; |
d001648e DH |
703 | if (call->completion == RXRPC_CALL_SUCCEEDED) { |
704 | ret = 1; | |
705 | if (size > 0) | |
706 | ret = -ECONNRESET; | |
707 | } | |
708 | goto out; | |
709 | } | |
710 | EXPORT_SYMBOL(rxrpc_kernel_recv_data); |