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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <linux/net.h> 15 #include <linux/skbuff.h> 16 #include <linux/export.h> 17 #include <linux/sched/signal.h> 18 19 #include <net/sock.h> 20 #include <net/af_rxrpc.h> 21 #include "ar-internal.h" 22 23 /* 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. 26 */ 27 void rxrpc_notify_socket(struct rxrpc_call *call) 28 { 29 struct rxrpc_sock *rx; 30 struct sock *sk; 31 32 _enter("%d", call->debug_id); 33 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) { 43 spin_lock_bh(&call->notify_lock); 44 call->notify_rx(sk, call, call->user_call_ID); 45 spin_unlock_bh(&call->notify_lock); 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); 53 54 if (!sock_flag(sk, SOCK_DEAD)) { 55 _debug("call %ps", sk->sk_data_ready); 56 sk->sk_data_ready(sk); 57 } 58 } 59 } 60 61 rcu_read_unlock(); 62 _leave(""); 63 } 64 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; 72 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: 88 tmp = -call->error; 89 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NET_ERROR, 4, &tmp); 90 break; 91 case RXRPC_CALL_LOCAL_ERROR: 92 tmp = -call->error; 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 } 100 101 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_terminal, call->rx_hard_ack, 102 call->rx_pkt_offset, call->rx_pkt_len, ret); 103 return ret; 104 } 105 106 /* 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; 118 119 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NEW_CALL, 0, &tmp); 120 121 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); 126 127 rxrpc_get_call(call, rxrpc_call_got); 128 write_lock(&rx->call_lock); 129 list_add_tail(&call->accept_link, &rx->to_be_accepted); 130 write_unlock(&rx->call_lock); 131 } 132 133 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_to_be_accepted, 1, 0, 0, ret); 134 return ret; 135 } 136 137 /* 138 * End the packet reception phase. 139 */ 140 static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial) 141 { 142 _enter("%d,%s", call->debug_id, rxrpc_call_states[call->state]); 143 144 trace_rxrpc_receive(call, rxrpc_receive_end, 0, call->rx_top); 145 ASSERTCMP(call->rx_hard_ack, ==, call->rx_top); 146 147 if (call->state == RXRPC_CALL_CLIENT_RECV_REPLY) { 148 rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, serial, false, true, 149 rxrpc_propose_ack_terminal_ack); 150 //rxrpc_send_ack_packet(call, false, NULL); 151 } 152 153 write_lock_bh(&call->state_lock); 154 155 switch (call->state) { 156 case RXRPC_CALL_CLIENT_RECV_REPLY: 157 __rxrpc_call_completed(call); 158 write_unlock_bh(&call->state_lock); 159 break; 160 161 case RXRPC_CALL_SERVER_RECV_REQUEST: 162 call->tx_phase = true; 163 call->state = RXRPC_CALL_SERVER_ACK_REQUEST; 164 call->expect_req_by = jiffies + MAX_JIFFY_OFFSET; 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); 168 break; 169 default: 170 write_unlock_bh(&call->state_lock); 171 break; 172 } 173 } 174 175 /* 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 { 180 struct rxrpc_skb_priv *sp; 181 struct sk_buff *skb; 182 rxrpc_serial_t serial; 183 rxrpc_seq_t hard_ack, top; 184 u8 flags; 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]; 196 rxrpc_see_skb(skb, rxrpc_skb_rx_rotated); 197 sp = rxrpc_skb(skb); 198 flags = sp->hdr.flags; 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; 202 203 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_rx_freed); 209 210 _debug("%u,%u,%02x", hard_ack, top, flags); 211 trace_rxrpc_receive(call, rxrpc_receive_rotate, serial, hard_ack); 212 if (flags & RXRPC_LAST_PACKET) { 213 rxrpc_end_rx_phase(call, serial); 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, true, 221 rxrpc_propose_ack_rotate_rx); 222 if (call->ackr_reason && call->ackr_reason != RXRPC_ACK_DELAY) 223 rxrpc_send_ack_packet(call, false, NULL); 224 } 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 { 272 unsigned int offset = sizeof(struct rxrpc_wire_header); 273 unsigned int len; 274 int ret; 275 u8 annotation = *_annotation; 276 277 /* Locate the subpacket */ 278 len = skb->len - offset; 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); 288 if (ret < 0) 289 return ret; 290 *_annotation |= RXRPC_RX_ANNO_VERIFIED; 291 } 292 293 *_offset = offset; 294 *_len = len; 295 call->conn->security->locate_data(call, skb, _offset, _len); 296 return 0; 297 } 298 299 /* 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; 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_rx_seen); 344 sp = rxrpc_skb(skb); 345 346 if (!(flags & MSG_PEEK)) 347 trace_rxrpc_receive(call, rxrpc_receive_front, 348 sp->hdr.serial, seq); 349 350 if (msg) 351 sock_recv_timestamp(msg, sock->sk, skb); 352 353 if (rx_pkt_offset == 0) { 354 ret2 = rxrpc_locate_data(call, skb, 355 &call->rxtx_annotations[ix], 356 &rx_pkt_offset, &rx_pkt_len); 357 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_next, seq, 358 rx_pkt_offset, rx_pkt_len, ret2); 359 if (ret2 < 0) { 360 ret = ret2; 361 goto out; 362 } 363 } else { 364 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_cont, seq, 365 rx_pkt_offset, rx_pkt_len, 0); 366 } 367 368 /* We have to handle short, empty and used-up DATA packets. */ 369 remain = len - *_offset; 370 copy = rx_pkt_len; 371 if (copy > remain) 372 copy = remain; 373 if (copy > 0) { 374 ret2 = skb_copy_datagram_iter(skb, rx_pkt_offset, iter, 375 copy); 376 if (ret2 < 0) { 377 ret = ret2; 378 goto out; 379 } 380 381 /* handle piecemeal consumption of data packets */ 382 rx_pkt_offset += copy; 383 rx_pkt_len -= copy; 384 *_offset += copy; 385 } 386 387 if (rx_pkt_len > 0) { 388 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_full, seq, 389 rx_pkt_offset, rx_pkt_len, 0); 390 ASSERTCMP(*_offset, ==, len); 391 ret = 0; 392 break; 393 } 394 395 /* The whole packet has been transferred. */ 396 last = sp->hdr.flags & RXRPC_LAST_PACKET; 397 if (!(flags & MSG_PEEK)) 398 rxrpc_rotate_rx_window(call); 399 rx_pkt_offset = 0; 400 rx_pkt_len = 0; 401 402 if (last) { 403 ASSERTCMP(seq, ==, READ_ONCE(call->rx_top)); 404 ret = 1; 405 goto out; 406 } 407 408 seq++; 409 } 410 411 out: 412 if (!(flags & MSG_PEEK)) { 413 call->rx_pkt_offset = rx_pkt_offset; 414 call->rx_pkt_len = rx_pkt_len; 415 } 416 done: 417 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_data_return, seq, 418 rx_pkt_offset, rx_pkt_len, ret); 419 if (ret == -EAGAIN) 420 set_bit(RXRPC_CALL_RX_UNDERRUN, &call->flags); 421 return ret; 422 } 423 424 /* 425 * Receive a message from an RxRPC socket 426 * - we need to be careful about two or more threads calling recvmsg 427 * simultaneously 428 */ 429 int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 430 int flags) 431 { 432 struct rxrpc_call *call; 433 struct rxrpc_sock *rx = rxrpc_sk(sock->sk); 434 struct list_head *l; 435 size_t copied = 0; 436 long timeo; 437 int ret; 438 439 DEFINE_WAIT(wait); 440 441 trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_enter, 0, 0, 0, 0); 442 443 if (flags & (MSG_OOB | MSG_TRUNC)) 444 return -EOPNOTSUPP; 445 446 timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT); 447 448 try_again: 449 lock_sock(&rx->sk); 450 451 /* Return immediately if a client socket has no outstanding calls */ 452 if (RB_EMPTY_ROOT(&rx->calls) && 453 list_empty(&rx->recvmsg_q) && 454 rx->sk.sk_state != RXRPC_SERVER_LISTENING) { 455 release_sock(&rx->sk); 456 return -ENODATA; 457 } 458 459 if (list_empty(&rx->recvmsg_q)) { 460 ret = -EWOULDBLOCK; 461 if (timeo == 0) { 462 call = NULL; 463 goto error_no_call; 464 } 465 466 release_sock(&rx->sk); 467 468 /* Wait for something to happen */ 469 prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait, 470 TASK_INTERRUPTIBLE); 471 ret = sock_error(&rx->sk); 472 if (ret) 473 goto wait_error; 474 475 if (list_empty(&rx->recvmsg_q)) { 476 if (signal_pending(current)) 477 goto wait_interrupted; 478 trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_wait, 479 0, 0, 0, 0); 480 timeo = schedule_timeout(timeo); 481 } 482 finish_wait(sk_sleep(&rx->sk), &wait); 483 goto try_again; 484 } 485 486 /* Find the next call and dequeue it if we're not just peeking. If we 487 * do dequeue it, that comes with a ref that we will need to release. 488 */ 489 write_lock_bh(&rx->recvmsg_lock); 490 l = rx->recvmsg_q.next; 491 call = list_entry(l, struct rxrpc_call, recvmsg_link); 492 if (!(flags & MSG_PEEK)) 493 list_del_init(&call->recvmsg_link); 494 else 495 rxrpc_get_call(call, rxrpc_call_got); 496 write_unlock_bh(&rx->recvmsg_lock); 497 498 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_dequeue, 0, 0, 0, 0); 499 500 /* We're going to drop the socket lock, so we need to lock the call 501 * against interference by sendmsg. 502 */ 503 if (!mutex_trylock(&call->user_mutex)) { 504 ret = -EWOULDBLOCK; 505 if (flags & MSG_DONTWAIT) 506 goto error_requeue_call; 507 ret = -ERESTARTSYS; 508 if (mutex_lock_interruptible(&call->user_mutex) < 0) 509 goto error_requeue_call; 510 } 511 512 release_sock(&rx->sk); 513 514 if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) 515 BUG(); 516 517 if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { 518 if (flags & MSG_CMSG_COMPAT) { 519 unsigned int id32 = call->user_call_ID; 520 521 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, 522 sizeof(unsigned int), &id32); 523 } else { 524 unsigned long idl = call->user_call_ID; 525 526 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, 527 sizeof(unsigned long), &idl); 528 } 529 if (ret < 0) 530 goto error_unlock_call; 531 } 532 533 if (msg->msg_name) { 534 struct sockaddr_rxrpc *srx = msg->msg_name; 535 size_t len = sizeof(call->peer->srx); 536 537 memcpy(msg->msg_name, &call->peer->srx, len); 538 srx->srx_service = call->service_id; 539 msg->msg_namelen = len; 540 } 541 542 switch (READ_ONCE(call->state)) { 543 case RXRPC_CALL_SERVER_ACCEPTING: 544 ret = rxrpc_recvmsg_new_call(rx, call, msg, flags); 545 break; 546 case RXRPC_CALL_CLIENT_RECV_REPLY: 547 case RXRPC_CALL_SERVER_RECV_REQUEST: 548 case RXRPC_CALL_SERVER_ACK_REQUEST: 549 ret = rxrpc_recvmsg_data(sock, call, msg, &msg->msg_iter, len, 550 flags, &copied); 551 if (ret == -EAGAIN) 552 ret = 0; 553 554 if (after(call->rx_top, call->rx_hard_ack) && 555 call->rxtx_buffer[(call->rx_hard_ack + 1) & RXRPC_RXTX_BUFF_MASK]) 556 rxrpc_notify_socket(call); 557 break; 558 default: 559 ret = 0; 560 break; 561 } 562 563 if (ret < 0) 564 goto error_unlock_call; 565 566 if (call->state == RXRPC_CALL_COMPLETE) { 567 ret = rxrpc_recvmsg_term(call, msg); 568 if (ret < 0) 569 goto error_unlock_call; 570 if (!(flags & MSG_PEEK)) 571 rxrpc_release_call(rx, call); 572 msg->msg_flags |= MSG_EOR; 573 ret = 1; 574 } 575 576 if (ret == 0) 577 msg->msg_flags |= MSG_MORE; 578 else 579 msg->msg_flags &= ~MSG_MORE; 580 ret = copied; 581 582 error_unlock_call: 583 mutex_unlock(&call->user_mutex); 584 rxrpc_put_call(call, rxrpc_call_put); 585 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, 0, 0, 0, ret); 586 return ret; 587 588 error_requeue_call: 589 if (!(flags & MSG_PEEK)) { 590 write_lock_bh(&rx->recvmsg_lock); 591 list_add(&call->recvmsg_link, &rx->recvmsg_q); 592 write_unlock_bh(&rx->recvmsg_lock); 593 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_requeue, 0, 0, 0, 0); 594 } else { 595 rxrpc_put_call(call, rxrpc_call_put); 596 } 597 error_no_call: 598 release_sock(&rx->sk); 599 error_trace: 600 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, 0, 0, 0, ret); 601 return ret; 602 603 wait_interrupted: 604 ret = sock_intr_errno(timeo); 605 wait_error: 606 finish_wait(sk_sleep(&rx->sk), &wait); 607 call = NULL; 608 goto error_trace; 609 } 610 611 /** 612 * rxrpc_kernel_recv_data - Allow a kernel service to receive data/info 613 * @sock: The socket that the call exists on 614 * @call: The call to send data through 615 * @iter: The buffer to receive into 616 * @want_more: True if more data is expected to be read 617 * @_abort: Where the abort code is stored if -ECONNABORTED is returned 618 * @_service: Where to store the actual service ID (may be upgraded) 619 * 620 * Allow a kernel service to receive data and pick up information about the 621 * state of a call. Returns 0 if got what was asked for and there's more 622 * available, 1 if we got what was asked for and we're at the end of the data 623 * and -EAGAIN if we need more data. 624 * 625 * Note that we may return -EAGAIN to drain empty packets at the end of the 626 * data, even if we've already copied over the requested data. 627 * 628 * *_abort should also be initialised to 0. 629 */ 630 int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call, 631 struct iov_iter *iter, 632 bool want_more, u32 *_abort, u16 *_service) 633 { 634 size_t offset = 0; 635 int ret; 636 637 _enter("{%d,%s},%zu,%d", 638 call->debug_id, rxrpc_call_states[call->state], 639 iov_iter_count(iter), want_more); 640 641 ASSERTCMP(call->state, !=, RXRPC_CALL_SERVER_ACCEPTING); 642 643 mutex_lock(&call->user_mutex); 644 645 switch (READ_ONCE(call->state)) { 646 case RXRPC_CALL_CLIENT_RECV_REPLY: 647 case RXRPC_CALL_SERVER_RECV_REQUEST: 648 case RXRPC_CALL_SERVER_ACK_REQUEST: 649 ret = rxrpc_recvmsg_data(sock, call, NULL, iter, 650 iov_iter_count(iter), 0, 651 &offset); 652 if (ret < 0) 653 goto out; 654 655 /* We can only reach here with a partially full buffer if we 656 * have reached the end of the data. We must otherwise have a 657 * full buffer or have been given -EAGAIN. 658 */ 659 if (ret == 1) { 660 if (iov_iter_count(iter) > 0) 661 goto short_data; 662 if (!want_more) 663 goto read_phase_complete; 664 ret = 0; 665 goto out; 666 } 667 668 if (!want_more) 669 goto excess_data; 670 goto out; 671 672 case RXRPC_CALL_COMPLETE: 673 goto call_complete; 674 675 default: 676 ret = -EINPROGRESS; 677 goto out; 678 } 679 680 read_phase_complete: 681 ret = 1; 682 out: 683 switch (call->ackr_reason) { 684 case RXRPC_ACK_IDLE: 685 break; 686 case RXRPC_ACK_DELAY: 687 if (ret != -EAGAIN) 688 break; 689 /* Fall through */ 690 default: 691 rxrpc_send_ack_packet(call, false, NULL); 692 } 693 694 if (_service) 695 *_service = call->service_id; 696 mutex_unlock(&call->user_mutex); 697 _leave(" = %d [%zu,%d]", ret, iov_iter_count(iter), *_abort); 698 return ret; 699 700 short_data: 701 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("short_data")); 702 ret = -EBADMSG; 703 goto out; 704 excess_data: 705 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("excess_data")); 706 ret = -EMSGSIZE; 707 goto out; 708 call_complete: 709 *_abort = call->abort_code; 710 ret = call->error; 711 if (call->completion == RXRPC_CALL_SUCCEEDED) { 712 ret = 1; 713 if (iov_iter_count(iter) > 0) 714 ret = -ECONNRESET; 715 } 716 goto out; 717 } 718 EXPORT_SYMBOL(rxrpc_kernel_recv_data); 719 720 /** 721 * rxrpc_kernel_get_reply_time - Get timestamp on first reply packet 722 * @sock: The socket that the call exists on 723 * @call: The call to query 724 * @_ts: Where to put the timestamp 725 * 726 * Retrieve the timestamp from the first DATA packet of the reply if it is 727 * in the ring. Returns true if successful, false if not. 728 */ 729 bool rxrpc_kernel_get_reply_time(struct socket *sock, struct rxrpc_call *call, 730 ktime_t *_ts) 731 { 732 struct sk_buff *skb; 733 rxrpc_seq_t hard_ack, top, seq; 734 bool success = false; 735 736 mutex_lock(&call->user_mutex); 737 738 if (READ_ONCE(call->state) != RXRPC_CALL_CLIENT_RECV_REPLY) 739 goto out; 740 741 hard_ack = call->rx_hard_ack; 742 if (hard_ack != 0) 743 goto out; 744 745 seq = hard_ack + 1; 746 top = smp_load_acquire(&call->rx_top); 747 if (after(seq, top)) 748 goto out; 749 750 skb = call->rxtx_buffer[seq & RXRPC_RXTX_BUFF_MASK]; 751 if (!skb) 752 goto out; 753 754 *_ts = skb_get_ktime(skb); 755 success = true; 756 757 out: 758 mutex_unlock(&call->user_mutex); 759 return success; 760 } 761 EXPORT_SYMBOL(rxrpc_kernel_get_reply_time); 762