1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* RxRPC recvmsg() implementation 3 * 4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/net.h> 11 #include <linux/skbuff.h> 12 #include <linux/export.h> 13 #include <linux/sched/signal.h> 14 15 #include <net/sock.h> 16 #include <net/af_rxrpc.h> 17 #include "ar-internal.h" 18 19 /* 20 * Post a call for attention by the socket or kernel service. Further 21 * notifications are suppressed by putting recvmsg_link on a dummy queue. 22 */ 23 void rxrpc_notify_socket(struct rxrpc_call *call) 24 { 25 struct rxrpc_sock *rx; 26 struct sock *sk; 27 28 _enter("%d", call->debug_id); 29 30 if (!list_empty(&call->recvmsg_link)) 31 return; 32 33 rcu_read_lock(); 34 35 rx = rcu_dereference(call->socket); 36 sk = &rx->sk; 37 if (rx && sk->sk_state < RXRPC_CLOSE) { 38 if (call->notify_rx) { 39 spin_lock_bh(&call->notify_lock); 40 call->notify_rx(sk, call, call->user_call_ID); 41 spin_unlock_bh(&call->notify_lock); 42 } else { 43 write_lock_bh(&rx->recvmsg_lock); 44 if (list_empty(&call->recvmsg_link)) { 45 rxrpc_get_call(call, rxrpc_call_got); 46 list_add_tail(&call->recvmsg_link, &rx->recvmsg_q); 47 } 48 write_unlock_bh(&rx->recvmsg_lock); 49 50 if (!sock_flag(sk, SOCK_DEAD)) { 51 _debug("call %ps", sk->sk_data_ready); 52 sk->sk_data_ready(sk); 53 } 54 } 55 } 56 57 rcu_read_unlock(); 58 _leave(""); 59 } 60 61 /* 62 * Pass a call terminating message to userspace. 63 */ 64 static int rxrpc_recvmsg_term(struct rxrpc_call *call, struct msghdr *msg) 65 { 66 u32 tmp = 0; 67 int ret; 68 69 switch (call->completion) { 70 case RXRPC_CALL_SUCCEEDED: 71 ret = 0; 72 if (rxrpc_is_service_call(call)) 73 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ACK, 0, &tmp); 74 break; 75 case RXRPC_CALL_REMOTELY_ABORTED: 76 tmp = call->abort_code; 77 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp); 78 break; 79 case RXRPC_CALL_LOCALLY_ABORTED: 80 tmp = call->abort_code; 81 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp); 82 break; 83 case RXRPC_CALL_NETWORK_ERROR: 84 tmp = -call->error; 85 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NET_ERROR, 4, &tmp); 86 break; 87 case RXRPC_CALL_LOCAL_ERROR: 88 tmp = -call->error; 89 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_LOCAL_ERROR, 4, &tmp); 90 break; 91 default: 92 pr_err("Invalid terminal call state %u\n", call->state); 93 BUG(); 94 break; 95 } 96 97 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_terminal, call->rx_hard_ack, 98 call->rx_pkt_offset, call->rx_pkt_len, ret); 99 return ret; 100 } 101 102 /* 103 * Pass back notification of a new call. The call is added to the 104 * to-be-accepted list. This means that the next call to be accepted might not 105 * be the last call seen awaiting acceptance, but unless we leave this on the 106 * front of the queue and block all other messages until someone gives us a 107 * user_ID for it, there's not a lot we can do. 108 */ 109 static int rxrpc_recvmsg_new_call(struct rxrpc_sock *rx, 110 struct rxrpc_call *call, 111 struct msghdr *msg, int flags) 112 { 113 int tmp = 0, ret; 114 115 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NEW_CALL, 0, &tmp); 116 117 if (ret == 0 && !(flags & MSG_PEEK)) { 118 _debug("to be accepted"); 119 write_lock_bh(&rx->recvmsg_lock); 120 list_del_init(&call->recvmsg_link); 121 write_unlock_bh(&rx->recvmsg_lock); 122 123 rxrpc_get_call(call, rxrpc_call_got); 124 write_lock(&rx->call_lock); 125 list_add_tail(&call->accept_link, &rx->to_be_accepted); 126 write_unlock(&rx->call_lock); 127 } 128 129 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_to_be_accepted, 1, 0, 0, ret); 130 return ret; 131 } 132 133 /* 134 * End the packet reception phase. 135 */ 136 static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial) 137 { 138 _enter("%d,%s", call->debug_id, rxrpc_call_states[call->state]); 139 140 trace_rxrpc_receive(call, rxrpc_receive_end, 0, call->rx_top); 141 ASSERTCMP(call->rx_hard_ack, ==, call->rx_top); 142 143 if (call->state == RXRPC_CALL_CLIENT_RECV_REPLY) { 144 rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, serial, false, true, 145 rxrpc_propose_ack_terminal_ack); 146 //rxrpc_send_ack_packet(call, false, NULL); 147 } 148 149 write_lock_bh(&call->state_lock); 150 151 switch (call->state) { 152 case RXRPC_CALL_CLIENT_RECV_REPLY: 153 __rxrpc_call_completed(call); 154 write_unlock_bh(&call->state_lock); 155 break; 156 157 case RXRPC_CALL_SERVER_RECV_REQUEST: 158 call->tx_phase = true; 159 call->state = RXRPC_CALL_SERVER_ACK_REQUEST; 160 call->expect_req_by = jiffies + MAX_JIFFY_OFFSET; 161 write_unlock_bh(&call->state_lock); 162 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial, false, true, 163 rxrpc_propose_ack_processing_op); 164 break; 165 default: 166 write_unlock_bh(&call->state_lock); 167 break; 168 } 169 } 170 171 /* 172 * Discard a packet we've used up and advance the Rx window by one. 173 */ 174 static void rxrpc_rotate_rx_window(struct rxrpc_call *call) 175 { 176 struct rxrpc_skb_priv *sp; 177 struct sk_buff *skb; 178 rxrpc_serial_t serial; 179 rxrpc_seq_t hard_ack, top; 180 bool last = false; 181 u8 subpacket; 182 int ix; 183 184 _enter("%d", call->debug_id); 185 186 hard_ack = call->rx_hard_ack; 187 top = smp_load_acquire(&call->rx_top); 188 ASSERT(before(hard_ack, top)); 189 190 hard_ack++; 191 ix = hard_ack & RXRPC_RXTX_BUFF_MASK; 192 skb = call->rxtx_buffer[ix]; 193 rxrpc_see_skb(skb, rxrpc_skb_rotated); 194 sp = rxrpc_skb(skb); 195 196 subpacket = call->rxtx_annotations[ix] & RXRPC_RX_ANNO_SUBPACKET; 197 serial = sp->hdr.serial + subpacket; 198 199 if (subpacket == sp->nr_subpackets - 1 && 200 sp->rx_flags & RXRPC_SKB_INCL_LAST) 201 last = true; 202 203 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); 207 208 rxrpc_free_skb(skb, rxrpc_skb_freed); 209 210 trace_rxrpc_receive(call, rxrpc_receive_rotate, serial, hard_ack); 211 if (last) { 212 rxrpc_end_rx_phase(call, serial); 213 } else { 214 /* Check to see if there's an ACK that needs sending. */ 215 if (after_eq(hard_ack, call->ackr_consumed + 2) || 216 after_eq(top, call->ackr_seen + 2) || 217 (hard_ack == top && after(hard_ack, call->ackr_consumed))) 218 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial, 219 true, true, 220 rxrpc_propose_ack_rotate_rx); 221 if (call->ackr_reason && call->ackr_reason != RXRPC_ACK_DELAY) 222 rxrpc_send_ack_packet(call, false, NULL); 223 } 224 } 225 226 /* 227 * Decrypt and verify a (sub)packet. The packet's length may be changed due to 228 * padding, but if this is the case, the packet length will be resident in the 229 * socket buffer. Note that we can't modify the master skb info as the skb may 230 * be the home to multiple subpackets. 231 */ 232 static int rxrpc_verify_packet(struct rxrpc_call *call, struct sk_buff *skb, 233 u8 annotation, 234 unsigned int offset, unsigned int len) 235 { 236 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 237 rxrpc_seq_t seq = sp->hdr.seq; 238 u16 cksum = sp->hdr.cksum; 239 u8 subpacket = annotation & RXRPC_RX_ANNO_SUBPACKET; 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 (subpacket > 0) { 247 __be16 tmp; 248 if (skb_copy_bits(skb, offset - 2, &tmp, 2) < 0) 249 BUG(); 250 cksum = ntohs(tmp); 251 seq += subpacket; 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 { 272 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 273 unsigned int offset = sizeof(struct rxrpc_wire_header); 274 unsigned int len; 275 int ret; 276 u8 annotation = *_annotation; 277 u8 subpacket = annotation & RXRPC_RX_ANNO_SUBPACKET; 278 279 /* Locate the subpacket */ 280 offset += subpacket * RXRPC_JUMBO_SUBPKTLEN; 281 len = skb->len - offset; 282 if (subpacket < sp->nr_subpackets - 1) 283 len = RXRPC_JUMBO_DATALEN; 284 285 if (!(annotation & RXRPC_RX_ANNO_VERIFIED)) { 286 ret = rxrpc_verify_packet(call, skb, annotation, offset, len); 287 if (ret < 0) 288 return ret; 289 *_annotation |= RXRPC_RX_ANNO_VERIFIED; 290 } 291 292 *_offset = offset; 293 *_len = len; 294 call->conn->security->locate_data(call, skb, _offset, _len); 295 return 0; 296 } 297 298 /* 299 * Deliver messages to a call. This keeps processing packets until the buffer 300 * is filled and we find either more DATA (returns 0) or the end of the DATA 301 * (returns 1). If more packets are required, it returns -EAGAIN. 302 */ 303 static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call, 304 struct msghdr *msg, struct iov_iter *iter, 305 size_t len, int flags, size_t *_offset) 306 { 307 struct rxrpc_skb_priv *sp; 308 struct sk_buff *skb; 309 rxrpc_serial_t serial; 310 rxrpc_seq_t hard_ack, top, seq; 311 size_t remain; 312 bool last; 313 unsigned int rx_pkt_offset, rx_pkt_len; 314 int ix, copy, ret = -EAGAIN, ret2; 315 316 if (test_and_clear_bit(RXRPC_CALL_RX_UNDERRUN, &call->flags) && 317 call->ackr_reason) 318 rxrpc_send_ack_packet(call, false, NULL); 319 320 rx_pkt_offset = call->rx_pkt_offset; 321 rx_pkt_len = call->rx_pkt_len; 322 323 if (call->state >= RXRPC_CALL_SERVER_ACK_REQUEST) { 324 seq = call->rx_hard_ack; 325 ret = 1; 326 goto done; 327 } 328 329 /* Barriers against rxrpc_input_data(). */ 330 hard_ack = call->rx_hard_ack; 331 seq = hard_ack + 1; 332 while (top = smp_load_acquire(&call->rx_top), 333 before_eq(seq, top) 334 ) { 335 ix = seq & RXRPC_RXTX_BUFF_MASK; 336 skb = call->rxtx_buffer[ix]; 337 if (!skb) { 338 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_hole, seq, 339 rx_pkt_offset, rx_pkt_len, 0); 340 break; 341 } 342 smp_rmb(); 343 rxrpc_see_skb(skb, rxrpc_skb_seen); 344 sp = rxrpc_skb(skb); 345 346 if (!(flags & MSG_PEEK)) { 347 serial = sp->hdr.serial; 348 serial += call->rxtx_annotations[ix] & RXRPC_RX_ANNO_SUBPACKET; 349 trace_rxrpc_receive(call, rxrpc_receive_front, 350 serial, seq); 351 } 352 353 if (msg) 354 sock_recv_timestamp(msg, sock->sk, skb); 355 356 if (rx_pkt_offset == 0) { 357 ret2 = rxrpc_locate_data(call, skb, 358 &call->rxtx_annotations[ix], 359 &rx_pkt_offset, &rx_pkt_len); 360 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_next, seq, 361 rx_pkt_offset, rx_pkt_len, ret2); 362 if (ret2 < 0) { 363 ret = ret2; 364 goto out; 365 } 366 } else { 367 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_cont, seq, 368 rx_pkt_offset, rx_pkt_len, 0); 369 } 370 371 /* We have to handle short, empty and used-up DATA packets. */ 372 remain = len - *_offset; 373 copy = rx_pkt_len; 374 if (copy > remain) 375 copy = remain; 376 if (copy > 0) { 377 ret2 = skb_copy_datagram_iter(skb, rx_pkt_offset, iter, 378 copy); 379 if (ret2 < 0) { 380 ret = ret2; 381 goto out; 382 } 383 384 /* handle piecemeal consumption of data packets */ 385 rx_pkt_offset += copy; 386 rx_pkt_len -= copy; 387 *_offset += copy; 388 } 389 390 if (rx_pkt_len > 0) { 391 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_full, seq, 392 rx_pkt_offset, rx_pkt_len, 0); 393 ASSERTCMP(*_offset, ==, len); 394 ret = 0; 395 break; 396 } 397 398 /* The whole packet has been transferred. */ 399 last = sp->hdr.flags & RXRPC_LAST_PACKET; 400 if (!(flags & MSG_PEEK)) 401 rxrpc_rotate_rx_window(call); 402 rx_pkt_offset = 0; 403 rx_pkt_len = 0; 404 405 if (last) { 406 ASSERTCMP(seq, ==, READ_ONCE(call->rx_top)); 407 ret = 1; 408 goto out; 409 } 410 411 seq++; 412 } 413 414 out: 415 if (!(flags & MSG_PEEK)) { 416 call->rx_pkt_offset = rx_pkt_offset; 417 call->rx_pkt_len = rx_pkt_len; 418 } 419 done: 420 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_data_return, seq, 421 rx_pkt_offset, rx_pkt_len, ret); 422 if (ret == -EAGAIN) 423 set_bit(RXRPC_CALL_RX_UNDERRUN, &call->flags); 424 return ret; 425 } 426 427 /* 428 * Receive a message from an RxRPC socket 429 * - we need to be careful about two or more threads calling recvmsg 430 * simultaneously 431 */ 432 int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 433 int flags) 434 { 435 struct rxrpc_call *call; 436 struct rxrpc_sock *rx = rxrpc_sk(sock->sk); 437 struct list_head *l; 438 size_t copied = 0; 439 long timeo; 440 int ret; 441 442 DEFINE_WAIT(wait); 443 444 trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_enter, 0, 0, 0, 0); 445 446 if (flags & (MSG_OOB | MSG_TRUNC)) 447 return -EOPNOTSUPP; 448 449 timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT); 450 451 try_again: 452 lock_sock(&rx->sk); 453 454 /* Return immediately if a client socket has no outstanding calls */ 455 if (RB_EMPTY_ROOT(&rx->calls) && 456 list_empty(&rx->recvmsg_q) && 457 rx->sk.sk_state != RXRPC_SERVER_LISTENING) { 458 release_sock(&rx->sk); 459 return -ENODATA; 460 } 461 462 if (list_empty(&rx->recvmsg_q)) { 463 ret = -EWOULDBLOCK; 464 if (timeo == 0) { 465 call = NULL; 466 goto error_no_call; 467 } 468 469 release_sock(&rx->sk); 470 471 /* Wait for something to happen */ 472 prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait, 473 TASK_INTERRUPTIBLE); 474 ret = sock_error(&rx->sk); 475 if (ret) 476 goto wait_error; 477 478 if (list_empty(&rx->recvmsg_q)) { 479 if (signal_pending(current)) 480 goto wait_interrupted; 481 trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_wait, 482 0, 0, 0, 0); 483 timeo = schedule_timeout(timeo); 484 } 485 finish_wait(sk_sleep(&rx->sk), &wait); 486 goto try_again; 487 } 488 489 /* Find the next call and dequeue it if we're not just peeking. If we 490 * do dequeue it, that comes with a ref that we will need to release. 491 */ 492 write_lock_bh(&rx->recvmsg_lock); 493 l = rx->recvmsg_q.next; 494 call = list_entry(l, struct rxrpc_call, recvmsg_link); 495 if (!(flags & MSG_PEEK)) 496 list_del_init(&call->recvmsg_link); 497 else 498 rxrpc_get_call(call, rxrpc_call_got); 499 write_unlock_bh(&rx->recvmsg_lock); 500 501 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_dequeue, 0, 0, 0, 0); 502 503 /* We're going to drop the socket lock, so we need to lock the call 504 * against interference by sendmsg. 505 */ 506 if (!mutex_trylock(&call->user_mutex)) { 507 ret = -EWOULDBLOCK; 508 if (flags & MSG_DONTWAIT) 509 goto error_requeue_call; 510 ret = -ERESTARTSYS; 511 if (mutex_lock_interruptible(&call->user_mutex) < 0) 512 goto error_requeue_call; 513 } 514 515 release_sock(&rx->sk); 516 517 if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) 518 BUG(); 519 520 if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { 521 if (flags & MSG_CMSG_COMPAT) { 522 unsigned int id32 = call->user_call_ID; 523 524 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, 525 sizeof(unsigned int), &id32); 526 } else { 527 unsigned long idl = call->user_call_ID; 528 529 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, 530 sizeof(unsigned long), &idl); 531 } 532 if (ret < 0) 533 goto error_unlock_call; 534 } 535 536 if (msg->msg_name) { 537 struct sockaddr_rxrpc *srx = msg->msg_name; 538 size_t len = sizeof(call->peer->srx); 539 540 memcpy(msg->msg_name, &call->peer->srx, len); 541 srx->srx_service = call->service_id; 542 msg->msg_namelen = len; 543 } 544 545 switch (READ_ONCE(call->state)) { 546 case RXRPC_CALL_SERVER_ACCEPTING: 547 ret = rxrpc_recvmsg_new_call(rx, call, msg, flags); 548 break; 549 case RXRPC_CALL_CLIENT_RECV_REPLY: 550 case RXRPC_CALL_SERVER_RECV_REQUEST: 551 case RXRPC_CALL_SERVER_ACK_REQUEST: 552 ret = rxrpc_recvmsg_data(sock, call, msg, &msg->msg_iter, len, 553 flags, &copied); 554 if (ret == -EAGAIN) 555 ret = 0; 556 557 if (after(call->rx_top, call->rx_hard_ack) && 558 call->rxtx_buffer[(call->rx_hard_ack + 1) & RXRPC_RXTX_BUFF_MASK]) 559 rxrpc_notify_socket(call); 560 break; 561 default: 562 ret = 0; 563 break; 564 } 565 566 if (ret < 0) 567 goto error_unlock_call; 568 569 if (call->state == RXRPC_CALL_COMPLETE) { 570 ret = rxrpc_recvmsg_term(call, msg); 571 if (ret < 0) 572 goto error_unlock_call; 573 if (!(flags & MSG_PEEK)) 574 rxrpc_release_call(rx, call); 575 msg->msg_flags |= MSG_EOR; 576 ret = 1; 577 } 578 579 if (ret == 0) 580 msg->msg_flags |= MSG_MORE; 581 else 582 msg->msg_flags &= ~MSG_MORE; 583 ret = copied; 584 585 error_unlock_call: 586 mutex_unlock(&call->user_mutex); 587 rxrpc_put_call(call, rxrpc_call_put); 588 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, 0, 0, 0, ret); 589 return ret; 590 591 error_requeue_call: 592 if (!(flags & MSG_PEEK)) { 593 write_lock_bh(&rx->recvmsg_lock); 594 list_add(&call->recvmsg_link, &rx->recvmsg_q); 595 write_unlock_bh(&rx->recvmsg_lock); 596 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_requeue, 0, 0, 0, 0); 597 } else { 598 rxrpc_put_call(call, rxrpc_call_put); 599 } 600 error_no_call: 601 release_sock(&rx->sk); 602 error_trace: 603 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, 0, 0, 0, ret); 604 return ret; 605 606 wait_interrupted: 607 ret = sock_intr_errno(timeo); 608 wait_error: 609 finish_wait(sk_sleep(&rx->sk), &wait); 610 call = NULL; 611 goto error_trace; 612 } 613 614 /** 615 * rxrpc_kernel_recv_data - Allow a kernel service to receive data/info 616 * @sock: The socket that the call exists on 617 * @call: The call to send data through 618 * @iter: The buffer to receive into 619 * @want_more: True if more data is expected to be read 620 * @_abort: Where the abort code is stored if -ECONNABORTED is returned 621 * @_service: Where to store the actual service ID (may be upgraded) 622 * 623 * Allow a kernel service to receive data and pick up information about the 624 * state of a call. Returns 0 if got what was asked for and there's more 625 * available, 1 if we got what was asked for and we're at the end of the data 626 * and -EAGAIN if we need more data. 627 * 628 * Note that we may return -EAGAIN to drain empty packets at the end of the 629 * data, even if we've already copied over the requested data. 630 * 631 * *_abort should also be initialised to 0. 632 */ 633 int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call, 634 struct iov_iter *iter, 635 bool want_more, u32 *_abort, u16 *_service) 636 { 637 size_t offset = 0; 638 int ret; 639 640 _enter("{%d,%s},%zu,%d", 641 call->debug_id, rxrpc_call_states[call->state], 642 iov_iter_count(iter), want_more); 643 644 ASSERTCMP(call->state, !=, RXRPC_CALL_SERVER_ACCEPTING); 645 646 mutex_lock(&call->user_mutex); 647 648 switch (READ_ONCE(call->state)) { 649 case RXRPC_CALL_CLIENT_RECV_REPLY: 650 case RXRPC_CALL_SERVER_RECV_REQUEST: 651 case RXRPC_CALL_SERVER_ACK_REQUEST: 652 ret = rxrpc_recvmsg_data(sock, call, NULL, iter, 653 iov_iter_count(iter), 0, 654 &offset); 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 (iov_iter_count(iter) > 0) 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: 679 ret = -EINPROGRESS; 680 goto out; 681 } 682 683 read_phase_complete: 684 ret = 1; 685 out: 686 switch (call->ackr_reason) { 687 case RXRPC_ACK_IDLE: 688 break; 689 case RXRPC_ACK_DELAY: 690 if (ret != -EAGAIN) 691 break; 692 /* Fall through */ 693 default: 694 rxrpc_send_ack_packet(call, false, NULL); 695 } 696 697 if (_service) 698 *_service = call->service_id; 699 mutex_unlock(&call->user_mutex); 700 _leave(" = %d [%zu,%d]", ret, iov_iter_count(iter), *_abort); 701 return ret; 702 703 short_data: 704 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("short_data")); 705 ret = -EBADMSG; 706 goto out; 707 excess_data: 708 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("excess_data")); 709 ret = -EMSGSIZE; 710 goto out; 711 call_complete: 712 *_abort = call->abort_code; 713 ret = call->error; 714 if (call->completion == RXRPC_CALL_SUCCEEDED) { 715 ret = 1; 716 if (iov_iter_count(iter) > 0) 717 ret = -ECONNRESET; 718 } 719 goto out; 720 } 721 EXPORT_SYMBOL(rxrpc_kernel_recv_data); 722 723 /** 724 * rxrpc_kernel_get_reply_time - Get timestamp on first reply packet 725 * @sock: The socket that the call exists on 726 * @call: The call to query 727 * @_ts: Where to put the timestamp 728 * 729 * Retrieve the timestamp from the first DATA packet of the reply if it is 730 * in the ring. Returns true if successful, false if not. 731 */ 732 bool rxrpc_kernel_get_reply_time(struct socket *sock, struct rxrpc_call *call, 733 ktime_t *_ts) 734 { 735 struct sk_buff *skb; 736 rxrpc_seq_t hard_ack, top, seq; 737 bool success = false; 738 739 mutex_lock(&call->user_mutex); 740 741 if (READ_ONCE(call->state) != RXRPC_CALL_CLIENT_RECV_REPLY) 742 goto out; 743 744 hard_ack = call->rx_hard_ack; 745 if (hard_ack != 0) 746 goto out; 747 748 seq = hard_ack + 1; 749 top = smp_load_acquire(&call->rx_top); 750 if (after(seq, top)) 751 goto out; 752 753 skb = call->rxtx_buffer[seq & RXRPC_RXTX_BUFF_MASK]; 754 if (!skb) 755 goto out; 756 757 *_ts = skb_get_ktime(skb); 758 success = true; 759 760 out: 761 mutex_unlock(&call->user_mutex); 762 return success; 763 } 764 EXPORT_SYMBOL(rxrpc_kernel_get_reply_time); 765