1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * common code for virtio vsock 4 * 5 * Copyright (C) 2013-2015 Red Hat, Inc. 6 * Author: Asias He <asias@redhat.com> 7 * Stefan Hajnoczi <stefanha@redhat.com> 8 */ 9#include <linux/spinlock.h> 10#include <linux/module.h> 11#include <linux/sched/signal.h> 12#include <linux/ctype.h> 13#include <linux/list.h> 14#include <linux/virtio_vsock.h> 15#include <uapi/linux/vsockmon.h> 16 17#include <net/sock.h> 18#include <net/af_vsock.h> 19 20#define CREATE_TRACE_POINTS 21#include <trace/events/vsock_virtio_transport_common.h> 22 23/* How long to wait for graceful shutdown of a connection */ 24#define VSOCK_CLOSE_TIMEOUT (8 * HZ) 25 26/* Threshold for detecting small packets to copy */ 27#define GOOD_COPY_LEN 128 28 29static const struct virtio_transport * 30virtio_transport_get_ops(struct vsock_sock *vsk) 31{ 32 const struct vsock_transport *t = vsock_core_get_transport(vsk); 33 34 if (WARN_ON(!t)) 35 return NULL; 36 37 return container_of(t, struct virtio_transport, transport); 38} 39 40static bool virtio_transport_can_zcopy(const struct virtio_transport *t_ops, 41 struct virtio_vsock_pkt_info *info, 42 size_t pkt_len) 43{ 44 struct iov_iter *iov_iter; 45 46 if (!info->msg) 47 return false; 48 49 iov_iter = &info->msg->msg_iter; 50 51 if (iov_iter->iov_offset) 52 return false; 53 54 /* We can't send whole iov. */ 55 if (iov_iter->count > pkt_len) 56 return false; 57 58 /* Check that transport can send data in zerocopy mode. */ 59 t_ops = virtio_transport_get_ops(info->vsk); 60 61 if (t_ops->can_msgzerocopy) { 62 int pages_to_send = iov_iter_npages(iov_iter, MAX_SKB_FRAGS); 63 64 /* +1 is for packet header. */ 65 return t_ops->can_msgzerocopy(pages_to_send + 1); 66 } 67 68 return true; 69} 70 71static int virtio_transport_init_zcopy_skb(struct vsock_sock *vsk, 72 struct sk_buff *skb, 73 struct msghdr *msg, 74 bool zerocopy) 75{ 76 struct ubuf_info *uarg; 77 78 if (msg->msg_ubuf) { 79 uarg = msg->msg_ubuf; 80 net_zcopy_get(uarg); 81 } else { 82 struct iov_iter *iter = &msg->msg_iter; 83 struct ubuf_info_msgzc *uarg_zc; 84 85 uarg = msg_zerocopy_realloc(sk_vsock(vsk), 86 iter->count, 87 NULL); 88 if (!uarg) 89 return -1; 90 91 uarg_zc = uarg_to_msgzc(uarg); 92 uarg_zc->zerocopy = zerocopy ? 1 : 0; 93 } 94 95 skb_zcopy_init(skb, uarg); 96 97 return 0; 98} 99 100static int virtio_transport_fill_skb(struct sk_buff *skb, 101 struct virtio_vsock_pkt_info *info, 102 size_t len, 103 bool zcopy) 104{ 105 if (zcopy) 106 return __zerocopy_sg_from_iter(info->msg, NULL, skb, 107 &info->msg->msg_iter, 108 len); 109 110 return memcpy_from_msg(skb_put(skb, len), info->msg, len); 111} 112 113static void virtio_transport_init_hdr(struct sk_buff *skb, 114 struct virtio_vsock_pkt_info *info, 115 size_t payload_len, 116 u32 src_cid, 117 u32 src_port, 118 u32 dst_cid, 119 u32 dst_port) 120{ 121 struct virtio_vsock_hdr *hdr; 122 123 hdr = virtio_vsock_hdr(skb); 124 hdr->type = cpu_to_le16(info->type); 125 hdr->op = cpu_to_le16(info->op); 126 hdr->src_cid = cpu_to_le64(src_cid); 127 hdr->dst_cid = cpu_to_le64(dst_cid); 128 hdr->src_port = cpu_to_le32(src_port); 129 hdr->dst_port = cpu_to_le32(dst_port); 130 hdr->flags = cpu_to_le32(info->flags); 131 hdr->len = cpu_to_le32(payload_len); 132 hdr->buf_alloc = cpu_to_le32(0); 133 hdr->fwd_cnt = cpu_to_le32(0); 134} 135 136static void virtio_transport_copy_nonlinear_skb(const struct sk_buff *skb, 137 void *dst, 138 size_t len) 139{ 140 struct iov_iter iov_iter = { 0 }; 141 struct kvec kvec; 142 size_t to_copy; 143 144 kvec.iov_base = dst; 145 kvec.iov_len = len; 146 147 iov_iter.iter_type = ITER_KVEC; 148 iov_iter.kvec = &kvec; 149 iov_iter.nr_segs = 1; 150 151 to_copy = min_t(size_t, len, skb->len); 152 153 skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset, 154 &iov_iter, to_copy); 155} 156 157/* Packet capture */ 158static struct sk_buff *virtio_transport_build_skb(void *opaque) 159{ 160 struct virtio_vsock_hdr *pkt_hdr; 161 struct sk_buff *pkt = opaque; 162 struct af_vsockmon_hdr *hdr; 163 struct sk_buff *skb; 164 size_t payload_len; 165 166 /* A packet could be split to fit the RX buffer, so we can retrieve 167 * the payload length from the header and the buffer pointer taking 168 * care of the offset in the original packet. 169 */ 170 pkt_hdr = virtio_vsock_hdr(pkt); 171 payload_len = pkt->len; 172 173 skb = alloc_skb(sizeof(*hdr) + sizeof(*pkt_hdr) + payload_len, 174 GFP_ATOMIC); 175 if (!skb) 176 return NULL; 177 178 hdr = skb_put(skb, sizeof(*hdr)); 179 180 /* pkt->hdr is little-endian so no need to byteswap here */ 181 hdr->src_cid = pkt_hdr->src_cid; 182 hdr->src_port = pkt_hdr->src_port; 183 hdr->dst_cid = pkt_hdr->dst_cid; 184 hdr->dst_port = pkt_hdr->dst_port; 185 186 hdr->transport = cpu_to_le16(AF_VSOCK_TRANSPORT_VIRTIO); 187 hdr->len = cpu_to_le16(sizeof(*pkt_hdr)); 188 memset(hdr->reserved, 0, sizeof(hdr->reserved)); 189 190 switch (le16_to_cpu(pkt_hdr->op)) { 191 case VIRTIO_VSOCK_OP_REQUEST: 192 case VIRTIO_VSOCK_OP_RESPONSE: 193 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONNECT); 194 break; 195 case VIRTIO_VSOCK_OP_RST: 196 case VIRTIO_VSOCK_OP_SHUTDOWN: 197 hdr->op = cpu_to_le16(AF_VSOCK_OP_DISCONNECT); 198 break; 199 case VIRTIO_VSOCK_OP_RW: 200 hdr->op = cpu_to_le16(AF_VSOCK_OP_PAYLOAD); 201 break; 202 case VIRTIO_VSOCK_OP_CREDIT_UPDATE: 203 case VIRTIO_VSOCK_OP_CREDIT_REQUEST: 204 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONTROL); 205 break; 206 default: 207 hdr->op = cpu_to_le16(AF_VSOCK_OP_UNKNOWN); 208 break; 209 } 210 211 skb_put_data(skb, pkt_hdr, sizeof(*pkt_hdr)); 212 213 if (payload_len) { 214 if (skb_is_nonlinear(pkt)) { 215 void *data = skb_put(skb, payload_len); 216 217 virtio_transport_copy_nonlinear_skb(pkt, data, payload_len); 218 } else { 219 skb_put_data(skb, pkt->data, payload_len); 220 } 221 } 222 223 return skb; 224} 225 226void virtio_transport_deliver_tap_pkt(struct sk_buff *skb) 227{ 228 if (virtio_vsock_skb_tap_delivered(skb)) 229 return; 230 231 vsock_deliver_tap(virtio_transport_build_skb, skb); 232 virtio_vsock_skb_set_tap_delivered(skb); 233} 234EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt); 235 236static u16 virtio_transport_get_type(struct sock *sk) 237{ 238 if (sk->sk_type == SOCK_STREAM) 239 return VIRTIO_VSOCK_TYPE_STREAM; 240 else 241 return VIRTIO_VSOCK_TYPE_SEQPACKET; 242} 243 244/* Returns new sk_buff on success, otherwise returns NULL. */ 245static struct sk_buff *virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *info, 246 size_t payload_len, 247 bool zcopy, 248 u32 src_cid, 249 u32 src_port, 250 u32 dst_cid, 251 u32 dst_port) 252{ 253 struct vsock_sock *vsk; 254 struct sk_buff *skb; 255 size_t skb_len; 256 257 skb_len = VIRTIO_VSOCK_SKB_HEADROOM; 258 259 if (!zcopy) 260 skb_len += payload_len; 261 262 skb = virtio_vsock_alloc_skb(skb_len, GFP_KERNEL); 263 if (!skb) 264 return NULL; 265 266 virtio_transport_init_hdr(skb, info, payload_len, src_cid, src_port, 267 dst_cid, dst_port); 268 269 vsk = info->vsk; 270 271 /* If 'vsk' != NULL then payload is always present, so we 272 * will never call '__zerocopy_sg_from_iter()' below without 273 * setting skb owner in 'skb_set_owner_w()'. The only case 274 * when 'vsk' == NULL is VIRTIO_VSOCK_OP_RST control message 275 * without payload. 276 */ 277 WARN_ON_ONCE(!(vsk && (info->msg && payload_len)) && zcopy); 278 279 /* Set owner here, because '__zerocopy_sg_from_iter()' uses 280 * owner of skb without check to update 'sk_wmem_alloc'. 281 */ 282 if (vsk) 283 skb_set_owner_w(skb, sk_vsock(vsk)); 284 285 if (info->msg && payload_len > 0) { 286 int err; 287 288 err = virtio_transport_fill_skb(skb, info, payload_len, zcopy); 289 if (err) 290 goto out; 291 292 if (msg_data_left(info->msg) == 0 && 293 info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) { 294 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 295 296 hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM); 297 298 if (info->msg->msg_flags & MSG_EOR) 299 hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR); 300 } 301 } 302 303 if (info->reply) 304 virtio_vsock_skb_set_reply(skb); 305 306 trace_virtio_transport_alloc_pkt(src_cid, src_port, 307 dst_cid, dst_port, 308 payload_len, 309 info->type, 310 info->op, 311 info->flags, 312 zcopy); 313 314 return skb; 315out: 316 kfree_skb(skb); 317 return NULL; 318} 319 320/* This function can only be used on connecting/connected sockets, 321 * since a socket assigned to a transport is required. 322 * 323 * Do not use on listener sockets! 324 */ 325static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, 326 struct virtio_vsock_pkt_info *info) 327{ 328 u32 max_skb_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE; 329 u32 src_cid, src_port, dst_cid, dst_port; 330 const struct virtio_transport *t_ops; 331 struct virtio_vsock_sock *vvs; 332 u32 pkt_len = info->pkt_len; 333 bool can_zcopy = false; 334 u32 rest_len; 335 int ret; 336 337 info->type = virtio_transport_get_type(sk_vsock(vsk)); 338 339 t_ops = virtio_transport_get_ops(vsk); 340 if (unlikely(!t_ops)) 341 return -EFAULT; 342 343 src_cid = t_ops->transport.get_local_cid(); 344 src_port = vsk->local_addr.svm_port; 345 if (!info->remote_cid) { 346 dst_cid = vsk->remote_addr.svm_cid; 347 dst_port = vsk->remote_addr.svm_port; 348 } else { 349 dst_cid = info->remote_cid; 350 dst_port = info->remote_port; 351 } 352 353 vvs = vsk->trans; 354 355 /* virtio_transport_get_credit might return less than pkt_len credit */ 356 pkt_len = virtio_transport_get_credit(vvs, pkt_len); 357 358 /* Do not send zero length OP_RW pkt */ 359 if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW) 360 return pkt_len; 361 362 if (info->msg) { 363 /* If zerocopy is not enabled by 'setsockopt()', we behave as 364 * there is no MSG_ZEROCOPY flag set. 365 */ 366 if (!sock_flag(sk_vsock(vsk), SOCK_ZEROCOPY)) 367 info->msg->msg_flags &= ~MSG_ZEROCOPY; 368 369 if (info->msg->msg_flags & MSG_ZEROCOPY) 370 can_zcopy = virtio_transport_can_zcopy(t_ops, info, pkt_len); 371 372 if (can_zcopy) 373 max_skb_len = min_t(u32, VIRTIO_VSOCK_MAX_PKT_BUF_SIZE, 374 (MAX_SKB_FRAGS * PAGE_SIZE)); 375 } 376 377 rest_len = pkt_len; 378 379 do { 380 struct sk_buff *skb; 381 size_t skb_len; 382 383 skb_len = min(max_skb_len, rest_len); 384 385 skb = virtio_transport_alloc_skb(info, skb_len, can_zcopy, 386 src_cid, src_port, 387 dst_cid, dst_port); 388 if (!skb) { 389 ret = -ENOMEM; 390 break; 391 } 392 393 /* We process buffer part by part, allocating skb on 394 * each iteration. If this is last skb for this buffer 395 * and MSG_ZEROCOPY mode is in use - we must allocate 396 * completion for the current syscall. 397 */ 398 if (info->msg && info->msg->msg_flags & MSG_ZEROCOPY && 399 skb_len == rest_len && info->op == VIRTIO_VSOCK_OP_RW) { 400 if (virtio_transport_init_zcopy_skb(vsk, skb, 401 info->msg, 402 can_zcopy)) { 403 ret = -ENOMEM; 404 break; 405 } 406 } 407 408 virtio_transport_inc_tx_pkt(vvs, skb); 409 410 ret = t_ops->send_pkt(skb); 411 if (ret < 0) 412 break; 413 414 /* Both virtio and vhost 'send_pkt()' returns 'skb_len', 415 * but for reliability use 'ret' instead of 'skb_len'. 416 * Also if partial send happens (e.g. 'ret' != 'skb_len') 417 * somehow, we break this loop, but account such returned 418 * value in 'virtio_transport_put_credit()'. 419 */ 420 rest_len -= ret; 421 422 if (WARN_ONCE(ret != skb_len, 423 "'send_pkt()' returns %i, but %zu expected\n", 424 ret, skb_len)) 425 break; 426 } while (rest_len); 427 428 virtio_transport_put_credit(vvs, rest_len); 429 430 /* Return number of bytes, if any data has been sent. */ 431 if (rest_len != pkt_len) 432 ret = pkt_len - rest_len; 433 434 return ret; 435} 436 437static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs, 438 u32 len) 439{ 440 if (vvs->rx_bytes + len > vvs->buf_alloc) 441 return false; 442 443 vvs->rx_bytes += len; 444 return true; 445} 446 447static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs, 448 u32 len) 449{ 450 vvs->rx_bytes -= len; 451 vvs->fwd_cnt += len; 452} 453 454void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct sk_buff *skb) 455{ 456 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 457 458 spin_lock_bh(&vvs->rx_lock); 459 vvs->last_fwd_cnt = vvs->fwd_cnt; 460 hdr->fwd_cnt = cpu_to_le32(vvs->fwd_cnt); 461 hdr->buf_alloc = cpu_to_le32(vvs->buf_alloc); 462 spin_unlock_bh(&vvs->rx_lock); 463} 464EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt); 465 466u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit) 467{ 468 u32 ret; 469 470 if (!credit) 471 return 0; 472 473 spin_lock_bh(&vvs->tx_lock); 474 ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt); 475 if (ret > credit) 476 ret = credit; 477 vvs->tx_cnt += ret; 478 spin_unlock_bh(&vvs->tx_lock); 479 480 return ret; 481} 482EXPORT_SYMBOL_GPL(virtio_transport_get_credit); 483 484void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit) 485{ 486 if (!credit) 487 return; 488 489 spin_lock_bh(&vvs->tx_lock); 490 vvs->tx_cnt -= credit; 491 spin_unlock_bh(&vvs->tx_lock); 492} 493EXPORT_SYMBOL_GPL(virtio_transport_put_credit); 494 495static int virtio_transport_send_credit_update(struct vsock_sock *vsk) 496{ 497 struct virtio_vsock_pkt_info info = { 498 .op = VIRTIO_VSOCK_OP_CREDIT_UPDATE, 499 .vsk = vsk, 500 }; 501 502 return virtio_transport_send_pkt_info(vsk, &info); 503} 504 505static ssize_t 506virtio_transport_stream_do_peek(struct vsock_sock *vsk, 507 struct msghdr *msg, 508 size_t len) 509{ 510 struct virtio_vsock_sock *vvs = vsk->trans; 511 struct sk_buff *skb; 512 size_t total = 0; 513 int err; 514 515 spin_lock_bh(&vvs->rx_lock); 516 517 skb_queue_walk(&vvs->rx_queue, skb) { 518 size_t bytes; 519 520 bytes = len - total; 521 if (bytes > skb->len) 522 bytes = skb->len; 523 524 spin_unlock_bh(&vvs->rx_lock); 525 526 /* sk_lock is held by caller so no one else can dequeue. 527 * Unlock rx_lock since skb_copy_datagram_iter() may sleep. 528 */ 529 err = skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset, 530 &msg->msg_iter, bytes); 531 if (err) 532 goto out; 533 534 total += bytes; 535 536 spin_lock_bh(&vvs->rx_lock); 537 538 if (total == len) 539 break; 540 } 541 542 spin_unlock_bh(&vvs->rx_lock); 543 544 return total; 545 546out: 547 if (total) 548 err = total; 549 return err; 550} 551 552static ssize_t 553virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, 554 struct msghdr *msg, 555 size_t len) 556{ 557 struct virtio_vsock_sock *vvs = vsk->trans; 558 size_t bytes, total = 0; 559 struct sk_buff *skb; 560 u32 fwd_cnt_delta; 561 bool low_rx_bytes; 562 int err = -EFAULT; 563 u32 free_space; 564 565 spin_lock_bh(&vvs->rx_lock); 566 567 if (WARN_ONCE(skb_queue_empty(&vvs->rx_queue) && vvs->rx_bytes, 568 "rx_queue is empty, but rx_bytes is non-zero\n")) { 569 spin_unlock_bh(&vvs->rx_lock); 570 return err; 571 } 572 573 while (total < len && !skb_queue_empty(&vvs->rx_queue)) { 574 skb = skb_peek(&vvs->rx_queue); 575 576 bytes = min_t(size_t, len - total, 577 skb->len - VIRTIO_VSOCK_SKB_CB(skb)->offset); 578 579 /* sk_lock is held by caller so no one else can dequeue. 580 * Unlock rx_lock since skb_copy_datagram_iter() may sleep. 581 */ 582 spin_unlock_bh(&vvs->rx_lock); 583 584 err = skb_copy_datagram_iter(skb, 585 VIRTIO_VSOCK_SKB_CB(skb)->offset, 586 &msg->msg_iter, bytes); 587 if (err) 588 goto out; 589 590 spin_lock_bh(&vvs->rx_lock); 591 592 total += bytes; 593 594 VIRTIO_VSOCK_SKB_CB(skb)->offset += bytes; 595 596 if (skb->len == VIRTIO_VSOCK_SKB_CB(skb)->offset) { 597 u32 pkt_len = le32_to_cpu(virtio_vsock_hdr(skb)->len); 598 599 virtio_transport_dec_rx_pkt(vvs, pkt_len); 600 __skb_unlink(skb, &vvs->rx_queue); 601 consume_skb(skb); 602 } 603 } 604 605 fwd_cnt_delta = vvs->fwd_cnt - vvs->last_fwd_cnt; 606 free_space = vvs->buf_alloc - fwd_cnt_delta; 607 low_rx_bytes = (vvs->rx_bytes < 608 sock_rcvlowat(sk_vsock(vsk), 0, INT_MAX)); 609 610 spin_unlock_bh(&vvs->rx_lock); 611 612 /* To reduce the number of credit update messages, 613 * don't update credits as long as lots of space is available. 614 * Note: the limit chosen here is arbitrary. Setting the limit 615 * too high causes extra messages. Too low causes transmitter 616 * stalls. As stalls are in theory more expensive than extra 617 * messages, we set the limit to a high value. TODO: experiment 618 * with different values. Also send credit update message when 619 * number of bytes in rx queue is not enough to wake up reader. 620 */ 621 if (fwd_cnt_delta && 622 (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE || low_rx_bytes)) 623 virtio_transport_send_credit_update(vsk); 624 625 return total; 626 627out: 628 if (total) 629 err = total; 630 return err; 631} 632 633static ssize_t 634virtio_transport_seqpacket_do_peek(struct vsock_sock *vsk, 635 struct msghdr *msg) 636{ 637 struct virtio_vsock_sock *vvs = vsk->trans; 638 struct sk_buff *skb; 639 size_t total, len; 640 641 spin_lock_bh(&vvs->rx_lock); 642 643 if (!vvs->msg_count) { 644 spin_unlock_bh(&vvs->rx_lock); 645 return 0; 646 } 647 648 total = 0; 649 len = msg_data_left(msg); 650 651 skb_queue_walk(&vvs->rx_queue, skb) { 652 struct virtio_vsock_hdr *hdr; 653 654 if (total < len) { 655 size_t bytes; 656 int err; 657 658 bytes = len - total; 659 if (bytes > skb->len) 660 bytes = skb->len; 661 662 spin_unlock_bh(&vvs->rx_lock); 663 664 /* sk_lock is held by caller so no one else can dequeue. 665 * Unlock rx_lock since skb_copy_datagram_iter() may sleep. 666 */ 667 err = skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset, 668 &msg->msg_iter, bytes); 669 if (err) 670 return err; 671 672 spin_lock_bh(&vvs->rx_lock); 673 } 674 675 total += skb->len; 676 hdr = virtio_vsock_hdr(skb); 677 678 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) { 679 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR) 680 msg->msg_flags |= MSG_EOR; 681 682 break; 683 } 684 } 685 686 spin_unlock_bh(&vvs->rx_lock); 687 688 return total; 689} 690 691static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk, 692 struct msghdr *msg, 693 int flags) 694{ 695 struct virtio_vsock_sock *vvs = vsk->trans; 696 int dequeued_len = 0; 697 size_t user_buf_len = msg_data_left(msg); 698 bool msg_ready = false; 699 struct sk_buff *skb; 700 701 spin_lock_bh(&vvs->rx_lock); 702 703 if (vvs->msg_count == 0) { 704 spin_unlock_bh(&vvs->rx_lock); 705 return 0; 706 } 707 708 while (!msg_ready) { 709 struct virtio_vsock_hdr *hdr; 710 size_t pkt_len; 711 712 skb = __skb_dequeue(&vvs->rx_queue); 713 if (!skb) 714 break; 715 hdr = virtio_vsock_hdr(skb); 716 pkt_len = (size_t)le32_to_cpu(hdr->len); 717 718 if (dequeued_len >= 0) { 719 size_t bytes_to_copy; 720 721 bytes_to_copy = min(user_buf_len, pkt_len); 722 723 if (bytes_to_copy) { 724 int err; 725 726 /* sk_lock is held by caller so no one else can dequeue. 727 * Unlock rx_lock since skb_copy_datagram_iter() may sleep. 728 */ 729 spin_unlock_bh(&vvs->rx_lock); 730 731 err = skb_copy_datagram_iter(skb, 0, 732 &msg->msg_iter, 733 bytes_to_copy); 734 if (err) { 735 /* Copy of message failed. Rest of 736 * fragments will be freed without copy. 737 */ 738 dequeued_len = err; 739 } else { 740 user_buf_len -= bytes_to_copy; 741 } 742 743 spin_lock_bh(&vvs->rx_lock); 744 } 745 746 if (dequeued_len >= 0) 747 dequeued_len += pkt_len; 748 } 749 750 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) { 751 msg_ready = true; 752 vvs->msg_count--; 753 754 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR) 755 msg->msg_flags |= MSG_EOR; 756 } 757 758 virtio_transport_dec_rx_pkt(vvs, pkt_len); 759 kfree_skb(skb); 760 } 761 762 spin_unlock_bh(&vvs->rx_lock); 763 764 virtio_transport_send_credit_update(vsk); 765 766 return dequeued_len; 767} 768 769ssize_t 770virtio_transport_stream_dequeue(struct vsock_sock *vsk, 771 struct msghdr *msg, 772 size_t len, int flags) 773{ 774 if (flags & MSG_PEEK) 775 return virtio_transport_stream_do_peek(vsk, msg, len); 776 else 777 return virtio_transport_stream_do_dequeue(vsk, msg, len); 778} 779EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue); 780 781ssize_t 782virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk, 783 struct msghdr *msg, 784 int flags) 785{ 786 if (flags & MSG_PEEK) 787 return virtio_transport_seqpacket_do_peek(vsk, msg); 788 else 789 return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags); 790} 791EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue); 792 793int 794virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk, 795 struct msghdr *msg, 796 size_t len) 797{ 798 struct virtio_vsock_sock *vvs = vsk->trans; 799 800 spin_lock_bh(&vvs->tx_lock); 801 802 if (len > vvs->peer_buf_alloc) { 803 spin_unlock_bh(&vvs->tx_lock); 804 return -EMSGSIZE; 805 } 806 807 spin_unlock_bh(&vvs->tx_lock); 808 809 return virtio_transport_stream_enqueue(vsk, msg, len); 810} 811EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_enqueue); 812 813int 814virtio_transport_dgram_dequeue(struct vsock_sock *vsk, 815 struct msghdr *msg, 816 size_t len, int flags) 817{ 818 return -EOPNOTSUPP; 819} 820EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue); 821 822s64 virtio_transport_stream_has_data(struct vsock_sock *vsk) 823{ 824 struct virtio_vsock_sock *vvs = vsk->trans; 825 s64 bytes; 826 827 spin_lock_bh(&vvs->rx_lock); 828 bytes = vvs->rx_bytes; 829 spin_unlock_bh(&vvs->rx_lock); 830 831 return bytes; 832} 833EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data); 834 835u32 virtio_transport_seqpacket_has_data(struct vsock_sock *vsk) 836{ 837 struct virtio_vsock_sock *vvs = vsk->trans; 838 u32 msg_count; 839 840 spin_lock_bh(&vvs->rx_lock); 841 msg_count = vvs->msg_count; 842 spin_unlock_bh(&vvs->rx_lock); 843 844 return msg_count; 845} 846EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_has_data); 847 848static s64 virtio_transport_has_space(struct vsock_sock *vsk) 849{ 850 struct virtio_vsock_sock *vvs = vsk->trans; 851 s64 bytes; 852 853 bytes = (s64)vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt); 854 if (bytes < 0) 855 bytes = 0; 856 857 return bytes; 858} 859 860s64 virtio_transport_stream_has_space(struct vsock_sock *vsk) 861{ 862 struct virtio_vsock_sock *vvs = vsk->trans; 863 s64 bytes; 864 865 spin_lock_bh(&vvs->tx_lock); 866 bytes = virtio_transport_has_space(vsk); 867 spin_unlock_bh(&vvs->tx_lock); 868 869 return bytes; 870} 871EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space); 872 873int virtio_transport_do_socket_init(struct vsock_sock *vsk, 874 struct vsock_sock *psk) 875{ 876 struct virtio_vsock_sock *vvs; 877 878 vvs = kzalloc(sizeof(*vvs), GFP_KERNEL); 879 if (!vvs) 880 return -ENOMEM; 881 882 vsk->trans = vvs; 883 vvs->vsk = vsk; 884 if (psk && psk->trans) { 885 struct virtio_vsock_sock *ptrans = psk->trans; 886 887 vvs->peer_buf_alloc = ptrans->peer_buf_alloc; 888 } 889 890 if (vsk->buffer_size > VIRTIO_VSOCK_MAX_BUF_SIZE) 891 vsk->buffer_size = VIRTIO_VSOCK_MAX_BUF_SIZE; 892 893 vvs->buf_alloc = vsk->buffer_size; 894 895 spin_lock_init(&vvs->rx_lock); 896 spin_lock_init(&vvs->tx_lock); 897 skb_queue_head_init(&vvs->rx_queue); 898 899 return 0; 900} 901EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init); 902 903/* sk_lock held by the caller */ 904void virtio_transport_notify_buffer_size(struct vsock_sock *vsk, u64 *val) 905{ 906 struct virtio_vsock_sock *vvs = vsk->trans; 907 908 if (*val > VIRTIO_VSOCK_MAX_BUF_SIZE) 909 *val = VIRTIO_VSOCK_MAX_BUF_SIZE; 910 911 vvs->buf_alloc = *val; 912 913 virtio_transport_send_credit_update(vsk); 914} 915EXPORT_SYMBOL_GPL(virtio_transport_notify_buffer_size); 916 917int 918virtio_transport_notify_poll_in(struct vsock_sock *vsk, 919 size_t target, 920 bool *data_ready_now) 921{ 922 *data_ready_now = vsock_stream_has_data(vsk) >= target; 923 924 return 0; 925} 926EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in); 927 928int 929virtio_transport_notify_poll_out(struct vsock_sock *vsk, 930 size_t target, 931 bool *space_avail_now) 932{ 933 s64 free_space; 934 935 free_space = vsock_stream_has_space(vsk); 936 if (free_space > 0) 937 *space_avail_now = true; 938 else if (free_space == 0) 939 *space_avail_now = false; 940 941 return 0; 942} 943EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out); 944 945int virtio_transport_notify_recv_init(struct vsock_sock *vsk, 946 size_t target, struct vsock_transport_recv_notify_data *data) 947{ 948 return 0; 949} 950EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init); 951 952int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk, 953 size_t target, struct vsock_transport_recv_notify_data *data) 954{ 955 return 0; 956} 957EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block); 958 959int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk, 960 size_t target, struct vsock_transport_recv_notify_data *data) 961{ 962 return 0; 963} 964EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue); 965 966int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk, 967 size_t target, ssize_t copied, bool data_read, 968 struct vsock_transport_recv_notify_data *data) 969{ 970 return 0; 971} 972EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue); 973 974int virtio_transport_notify_send_init(struct vsock_sock *vsk, 975 struct vsock_transport_send_notify_data *data) 976{ 977 return 0; 978} 979EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init); 980 981int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk, 982 struct vsock_transport_send_notify_data *data) 983{ 984 return 0; 985} 986EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block); 987 988int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk, 989 struct vsock_transport_send_notify_data *data) 990{ 991 return 0; 992} 993EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue); 994 995int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk, 996 ssize_t written, struct vsock_transport_send_notify_data *data) 997{ 998 return 0; 999} 1000EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue); 1001 1002u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk) 1003{ 1004 return vsk->buffer_size; 1005} 1006EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat); 1007 1008bool virtio_transport_stream_is_active(struct vsock_sock *vsk) 1009{ 1010 return true; 1011} 1012EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active); 1013 1014bool virtio_transport_stream_allow(u32 cid, u32 port) 1015{ 1016 return true; 1017} 1018EXPORT_SYMBOL_GPL(virtio_transport_stream_allow); 1019 1020int virtio_transport_dgram_bind(struct vsock_sock *vsk, 1021 struct sockaddr_vm *addr) 1022{ 1023 return -EOPNOTSUPP; 1024} 1025EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind); 1026 1027bool virtio_transport_dgram_allow(u32 cid, u32 port) 1028{ 1029 return false; 1030} 1031EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow); 1032 1033int virtio_transport_connect(struct vsock_sock *vsk) 1034{ 1035 struct virtio_vsock_pkt_info info = { 1036 .op = VIRTIO_VSOCK_OP_REQUEST, 1037 .vsk = vsk, 1038 }; 1039 1040 return virtio_transport_send_pkt_info(vsk, &info); 1041} 1042EXPORT_SYMBOL_GPL(virtio_transport_connect); 1043 1044int virtio_transport_shutdown(struct vsock_sock *vsk, int mode) 1045{ 1046 struct virtio_vsock_pkt_info info = { 1047 .op = VIRTIO_VSOCK_OP_SHUTDOWN, 1048 .flags = (mode & RCV_SHUTDOWN ? 1049 VIRTIO_VSOCK_SHUTDOWN_RCV : 0) | 1050 (mode & SEND_SHUTDOWN ? 1051 VIRTIO_VSOCK_SHUTDOWN_SEND : 0), 1052 .vsk = vsk, 1053 }; 1054 1055 return virtio_transport_send_pkt_info(vsk, &info); 1056} 1057EXPORT_SYMBOL_GPL(virtio_transport_shutdown); 1058 1059int 1060virtio_transport_dgram_enqueue(struct vsock_sock *vsk, 1061 struct sockaddr_vm *remote_addr, 1062 struct msghdr *msg, 1063 size_t dgram_len) 1064{ 1065 return -EOPNOTSUPP; 1066} 1067EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue); 1068 1069ssize_t 1070virtio_transport_stream_enqueue(struct vsock_sock *vsk, 1071 struct msghdr *msg, 1072 size_t len) 1073{ 1074 struct virtio_vsock_pkt_info info = { 1075 .op = VIRTIO_VSOCK_OP_RW, 1076 .msg = msg, 1077 .pkt_len = len, 1078 .vsk = vsk, 1079 }; 1080 1081 return virtio_transport_send_pkt_info(vsk, &info); 1082} 1083EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue); 1084 1085void virtio_transport_destruct(struct vsock_sock *vsk) 1086{ 1087 struct virtio_vsock_sock *vvs = vsk->trans; 1088 1089 kfree(vvs); 1090} 1091EXPORT_SYMBOL_GPL(virtio_transport_destruct); 1092 1093static int virtio_transport_reset(struct vsock_sock *vsk, 1094 struct sk_buff *skb) 1095{ 1096 struct virtio_vsock_pkt_info info = { 1097 .op = VIRTIO_VSOCK_OP_RST, 1098 .reply = !!skb, 1099 .vsk = vsk, 1100 }; 1101 1102 /* Send RST only if the original pkt is not a RST pkt */ 1103 if (skb && le16_to_cpu(virtio_vsock_hdr(skb)->op) == VIRTIO_VSOCK_OP_RST) 1104 return 0; 1105 1106 return virtio_transport_send_pkt_info(vsk, &info); 1107} 1108 1109/* Normally packets are associated with a socket. There may be no socket if an 1110 * attempt was made to connect to a socket that does not exist. 1111 */ 1112static int virtio_transport_reset_no_sock(const struct virtio_transport *t, 1113 struct sk_buff *skb) 1114{ 1115 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1116 struct virtio_vsock_pkt_info info = { 1117 .op = VIRTIO_VSOCK_OP_RST, 1118 .type = le16_to_cpu(hdr->type), 1119 .reply = true, 1120 }; 1121 struct sk_buff *reply; 1122 1123 /* Send RST only if the original pkt is not a RST pkt */ 1124 if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST) 1125 return 0; 1126 1127 if (!t) 1128 return -ENOTCONN; 1129 1130 reply = virtio_transport_alloc_skb(&info, 0, false, 1131 le64_to_cpu(hdr->dst_cid), 1132 le32_to_cpu(hdr->dst_port), 1133 le64_to_cpu(hdr->src_cid), 1134 le32_to_cpu(hdr->src_port)); 1135 if (!reply) 1136 return -ENOMEM; 1137 1138 return t->send_pkt(reply); 1139} 1140 1141/* This function should be called with sk_lock held and SOCK_DONE set */ 1142static void virtio_transport_remove_sock(struct vsock_sock *vsk) 1143{ 1144 struct virtio_vsock_sock *vvs = vsk->trans; 1145 1146 /* We don't need to take rx_lock, as the socket is closing and we are 1147 * removing it. 1148 */ 1149 __skb_queue_purge(&vvs->rx_queue); 1150 vsock_remove_sock(vsk); 1151} 1152 1153static void virtio_transport_wait_close(struct sock *sk, long timeout) 1154{ 1155 if (timeout) { 1156 DEFINE_WAIT_FUNC(wait, woken_wake_function); 1157 1158 add_wait_queue(sk_sleep(sk), &wait); 1159 1160 do { 1161 if (sk_wait_event(sk, &timeout, 1162 sock_flag(sk, SOCK_DONE), &wait)) 1163 break; 1164 } while (!signal_pending(current) && timeout); 1165 1166 remove_wait_queue(sk_sleep(sk), &wait); 1167 } 1168} 1169 1170static void virtio_transport_do_close(struct vsock_sock *vsk, 1171 bool cancel_timeout) 1172{ 1173 struct sock *sk = sk_vsock(vsk); 1174 1175 sock_set_flag(sk, SOCK_DONE); 1176 vsk->peer_shutdown = SHUTDOWN_MASK; 1177 if (vsock_stream_has_data(vsk) <= 0) 1178 sk->sk_state = TCP_CLOSING; 1179 sk->sk_state_change(sk); 1180 1181 if (vsk->close_work_scheduled && 1182 (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) { 1183 vsk->close_work_scheduled = false; 1184 1185 virtio_transport_remove_sock(vsk); 1186 1187 /* Release refcnt obtained when we scheduled the timeout */ 1188 sock_put(sk); 1189 } 1190} 1191 1192static void virtio_transport_close_timeout(struct work_struct *work) 1193{ 1194 struct vsock_sock *vsk = 1195 container_of(work, struct vsock_sock, close_work.work); 1196 struct sock *sk = sk_vsock(vsk); 1197 1198 sock_hold(sk); 1199 lock_sock(sk); 1200 1201 if (!sock_flag(sk, SOCK_DONE)) { 1202 (void)virtio_transport_reset(vsk, NULL); 1203 1204 virtio_transport_do_close(vsk, false); 1205 } 1206 1207 vsk->close_work_scheduled = false; 1208 1209 release_sock(sk); 1210 sock_put(sk); 1211} 1212 1213/* User context, vsk->sk is locked */ 1214static bool virtio_transport_close(struct vsock_sock *vsk) 1215{ 1216 struct sock *sk = &vsk->sk; 1217 1218 if (!(sk->sk_state == TCP_ESTABLISHED || 1219 sk->sk_state == TCP_CLOSING)) 1220 return true; 1221 1222 /* Already received SHUTDOWN from peer, reply with RST */ 1223 if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) { 1224 (void)virtio_transport_reset(vsk, NULL); 1225 return true; 1226 } 1227 1228 if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK) 1229 (void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK); 1230 1231 if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING)) 1232 virtio_transport_wait_close(sk, sk->sk_lingertime); 1233 1234 if (sock_flag(sk, SOCK_DONE)) { 1235 return true; 1236 } 1237 1238 sock_hold(sk); 1239 INIT_DELAYED_WORK(&vsk->close_work, 1240 virtio_transport_close_timeout); 1241 vsk->close_work_scheduled = true; 1242 schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT); 1243 return false; 1244} 1245 1246void virtio_transport_release(struct vsock_sock *vsk) 1247{ 1248 struct sock *sk = &vsk->sk; 1249 bool remove_sock = true; 1250 1251 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) 1252 remove_sock = virtio_transport_close(vsk); 1253 1254 if (remove_sock) { 1255 sock_set_flag(sk, SOCK_DONE); 1256 virtio_transport_remove_sock(vsk); 1257 } 1258} 1259EXPORT_SYMBOL_GPL(virtio_transport_release); 1260 1261static int 1262virtio_transport_recv_connecting(struct sock *sk, 1263 struct sk_buff *skb) 1264{ 1265 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1266 struct vsock_sock *vsk = vsock_sk(sk); 1267 int skerr; 1268 int err; 1269 1270 switch (le16_to_cpu(hdr->op)) { 1271 case VIRTIO_VSOCK_OP_RESPONSE: 1272 sk->sk_state = TCP_ESTABLISHED; 1273 sk->sk_socket->state = SS_CONNECTED; 1274 vsock_insert_connected(vsk); 1275 sk->sk_state_change(sk); 1276 break; 1277 case VIRTIO_VSOCK_OP_INVALID: 1278 break; 1279 case VIRTIO_VSOCK_OP_RST: 1280 skerr = ECONNRESET; 1281 err = 0; 1282 goto destroy; 1283 default: 1284 skerr = EPROTO; 1285 err = -EINVAL; 1286 goto destroy; 1287 } 1288 return 0; 1289 1290destroy: 1291 virtio_transport_reset(vsk, skb); 1292 sk->sk_state = TCP_CLOSE; 1293 sk->sk_err = skerr; 1294 sk_error_report(sk); 1295 return err; 1296} 1297 1298static void 1299virtio_transport_recv_enqueue(struct vsock_sock *vsk, 1300 struct sk_buff *skb) 1301{ 1302 struct virtio_vsock_sock *vvs = vsk->trans; 1303 bool can_enqueue, free_pkt = false; 1304 struct virtio_vsock_hdr *hdr; 1305 u32 len; 1306 1307 hdr = virtio_vsock_hdr(skb); 1308 len = le32_to_cpu(hdr->len); 1309 1310 spin_lock_bh(&vvs->rx_lock); 1311 1312 can_enqueue = virtio_transport_inc_rx_pkt(vvs, len); 1313 if (!can_enqueue) { 1314 free_pkt = true; 1315 goto out; 1316 } 1317 1318 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) 1319 vvs->msg_count++; 1320 1321 /* Try to copy small packets into the buffer of last packet queued, 1322 * to avoid wasting memory queueing the entire buffer with a small 1323 * payload. 1324 */ 1325 if (len <= GOOD_COPY_LEN && !skb_queue_empty(&vvs->rx_queue)) { 1326 struct virtio_vsock_hdr *last_hdr; 1327 struct sk_buff *last_skb; 1328 1329 last_skb = skb_peek_tail(&vvs->rx_queue); 1330 last_hdr = virtio_vsock_hdr(last_skb); 1331 1332 /* If there is space in the last packet queued, we copy the 1333 * new packet in its buffer. We avoid this if the last packet 1334 * queued has VIRTIO_VSOCK_SEQ_EOM set, because this is 1335 * delimiter of SEQPACKET message, so 'pkt' is the first packet 1336 * of a new message. 1337 */ 1338 if (skb->len < skb_tailroom(last_skb) && 1339 !(le32_to_cpu(last_hdr->flags) & VIRTIO_VSOCK_SEQ_EOM)) { 1340 memcpy(skb_put(last_skb, skb->len), skb->data, skb->len); 1341 free_pkt = true; 1342 last_hdr->flags |= hdr->flags; 1343 le32_add_cpu(&last_hdr->len, len); 1344 goto out; 1345 } 1346 } 1347 1348 __skb_queue_tail(&vvs->rx_queue, skb); 1349 1350out: 1351 spin_unlock_bh(&vvs->rx_lock); 1352 if (free_pkt) 1353 kfree_skb(skb); 1354} 1355 1356static int 1357virtio_transport_recv_connected(struct sock *sk, 1358 struct sk_buff *skb) 1359{ 1360 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1361 struct vsock_sock *vsk = vsock_sk(sk); 1362 int err = 0; 1363 1364 switch (le16_to_cpu(hdr->op)) { 1365 case VIRTIO_VSOCK_OP_RW: 1366 virtio_transport_recv_enqueue(vsk, skb); 1367 vsock_data_ready(sk); 1368 return err; 1369 case VIRTIO_VSOCK_OP_CREDIT_REQUEST: 1370 virtio_transport_send_credit_update(vsk); 1371 break; 1372 case VIRTIO_VSOCK_OP_CREDIT_UPDATE: 1373 sk->sk_write_space(sk); 1374 break; 1375 case VIRTIO_VSOCK_OP_SHUTDOWN: 1376 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_RCV) 1377 vsk->peer_shutdown |= RCV_SHUTDOWN; 1378 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_SEND) 1379 vsk->peer_shutdown |= SEND_SHUTDOWN; 1380 if (vsk->peer_shutdown == SHUTDOWN_MASK) { 1381 if (vsock_stream_has_data(vsk) <= 0 && !sock_flag(sk, SOCK_DONE)) { 1382 (void)virtio_transport_reset(vsk, NULL); 1383 virtio_transport_do_close(vsk, true); 1384 } 1385 /* Remove this socket anyway because the remote peer sent 1386 * the shutdown. This way a new connection will succeed 1387 * if the remote peer uses the same source port, 1388 * even if the old socket is still unreleased, but now disconnected. 1389 */ 1390 vsock_remove_sock(vsk); 1391 } 1392 if (le32_to_cpu(virtio_vsock_hdr(skb)->flags)) 1393 sk->sk_state_change(sk); 1394 break; 1395 case VIRTIO_VSOCK_OP_RST: 1396 virtio_transport_do_close(vsk, true); 1397 break; 1398 default: 1399 err = -EINVAL; 1400 break; 1401 } 1402 1403 kfree_skb(skb); 1404 return err; 1405} 1406 1407static void 1408virtio_transport_recv_disconnecting(struct sock *sk, 1409 struct sk_buff *skb) 1410{ 1411 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1412 struct vsock_sock *vsk = vsock_sk(sk); 1413 1414 if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST) 1415 virtio_transport_do_close(vsk, true); 1416} 1417 1418static int 1419virtio_transport_send_response(struct vsock_sock *vsk, 1420 struct sk_buff *skb) 1421{ 1422 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1423 struct virtio_vsock_pkt_info info = { 1424 .op = VIRTIO_VSOCK_OP_RESPONSE, 1425 .remote_cid = le64_to_cpu(hdr->src_cid), 1426 .remote_port = le32_to_cpu(hdr->src_port), 1427 .reply = true, 1428 .vsk = vsk, 1429 }; 1430 1431 return virtio_transport_send_pkt_info(vsk, &info); 1432} 1433 1434static bool virtio_transport_space_update(struct sock *sk, 1435 struct sk_buff *skb) 1436{ 1437 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1438 struct vsock_sock *vsk = vsock_sk(sk); 1439 struct virtio_vsock_sock *vvs = vsk->trans; 1440 bool space_available; 1441 1442 /* Listener sockets are not associated with any transport, so we are 1443 * not able to take the state to see if there is space available in the 1444 * remote peer, but since they are only used to receive requests, we 1445 * can assume that there is always space available in the other peer. 1446 */ 1447 if (!vvs) 1448 return true; 1449 1450 /* buf_alloc and fwd_cnt is always included in the hdr */ 1451 spin_lock_bh(&vvs->tx_lock); 1452 vvs->peer_buf_alloc = le32_to_cpu(hdr->buf_alloc); 1453 vvs->peer_fwd_cnt = le32_to_cpu(hdr->fwd_cnt); 1454 space_available = virtio_transport_has_space(vsk); 1455 spin_unlock_bh(&vvs->tx_lock); 1456 return space_available; 1457} 1458 1459/* Handle server socket */ 1460static int 1461virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb, 1462 struct virtio_transport *t) 1463{ 1464 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1465 struct vsock_sock *vsk = vsock_sk(sk); 1466 struct vsock_sock *vchild; 1467 struct sock *child; 1468 int ret; 1469 1470 if (le16_to_cpu(hdr->op) != VIRTIO_VSOCK_OP_REQUEST) { 1471 virtio_transport_reset_no_sock(t, skb); 1472 return -EINVAL; 1473 } 1474 1475 if (sk_acceptq_is_full(sk)) { 1476 virtio_transport_reset_no_sock(t, skb); 1477 return -ENOMEM; 1478 } 1479 1480 child = vsock_create_connected(sk); 1481 if (!child) { 1482 virtio_transport_reset_no_sock(t, skb); 1483 return -ENOMEM; 1484 } 1485 1486 sk_acceptq_added(sk); 1487 1488 lock_sock_nested(child, SINGLE_DEPTH_NESTING); 1489 1490 child->sk_state = TCP_ESTABLISHED; 1491 1492 vchild = vsock_sk(child); 1493 vsock_addr_init(&vchild->local_addr, le64_to_cpu(hdr->dst_cid), 1494 le32_to_cpu(hdr->dst_port)); 1495 vsock_addr_init(&vchild->remote_addr, le64_to_cpu(hdr->src_cid), 1496 le32_to_cpu(hdr->src_port)); 1497 1498 ret = vsock_assign_transport(vchild, vsk); 1499 /* Transport assigned (looking at remote_addr) must be the same 1500 * where we received the request. 1501 */ 1502 if (ret || vchild->transport != &t->transport) { 1503 release_sock(child); 1504 virtio_transport_reset_no_sock(t, skb); 1505 sock_put(child); 1506 return ret; 1507 } 1508 1509 if (virtio_transport_space_update(child, skb)) 1510 child->sk_write_space(child); 1511 1512 vsock_insert_connected(vchild); 1513 vsock_enqueue_accept(sk, child); 1514 virtio_transport_send_response(vchild, skb); 1515 1516 release_sock(child); 1517 1518 sk->sk_data_ready(sk); 1519 return 0; 1520} 1521 1522static bool virtio_transport_valid_type(u16 type) 1523{ 1524 return (type == VIRTIO_VSOCK_TYPE_STREAM) || 1525 (type == VIRTIO_VSOCK_TYPE_SEQPACKET); 1526} 1527 1528/* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex 1529 * lock. 1530 */ 1531void virtio_transport_recv_pkt(struct virtio_transport *t, 1532 struct sk_buff *skb) 1533{ 1534 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1535 struct sockaddr_vm src, dst; 1536 struct vsock_sock *vsk; 1537 struct sock *sk; 1538 bool space_available; 1539 1540 vsock_addr_init(&src, le64_to_cpu(hdr->src_cid), 1541 le32_to_cpu(hdr->src_port)); 1542 vsock_addr_init(&dst, le64_to_cpu(hdr->dst_cid), 1543 le32_to_cpu(hdr->dst_port)); 1544 1545 trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port, 1546 dst.svm_cid, dst.svm_port, 1547 le32_to_cpu(hdr->len), 1548 le16_to_cpu(hdr->type), 1549 le16_to_cpu(hdr->op), 1550 le32_to_cpu(hdr->flags), 1551 le32_to_cpu(hdr->buf_alloc), 1552 le32_to_cpu(hdr->fwd_cnt)); 1553 1554 if (!virtio_transport_valid_type(le16_to_cpu(hdr->type))) { 1555 (void)virtio_transport_reset_no_sock(t, skb); 1556 goto free_pkt; 1557 } 1558 1559 /* The socket must be in connected or bound table 1560 * otherwise send reset back 1561 */ 1562 sk = vsock_find_connected_socket(&src, &dst); 1563 if (!sk) { 1564 sk = vsock_find_bound_socket(&dst); 1565 if (!sk) { 1566 (void)virtio_transport_reset_no_sock(t, skb); 1567 goto free_pkt; 1568 } 1569 } 1570 1571 if (virtio_transport_get_type(sk) != le16_to_cpu(hdr->type)) { 1572 (void)virtio_transport_reset_no_sock(t, skb); 1573 sock_put(sk); 1574 goto free_pkt; 1575 } 1576 1577 if (!skb_set_owner_sk_safe(skb, sk)) { 1578 WARN_ONCE(1, "receiving vsock socket has sk_refcnt == 0\n"); 1579 goto free_pkt; 1580 } 1581 1582 vsk = vsock_sk(sk); 1583 1584 lock_sock(sk); 1585 1586 /* Check if sk has been closed before lock_sock */ 1587 if (sock_flag(sk, SOCK_DONE)) { 1588 (void)virtio_transport_reset_no_sock(t, skb); 1589 release_sock(sk); 1590 sock_put(sk); 1591 goto free_pkt; 1592 } 1593 1594 space_available = virtio_transport_space_update(sk, skb); 1595 1596 /* Update CID in case it has changed after a transport reset event */ 1597 if (vsk->local_addr.svm_cid != VMADDR_CID_ANY) 1598 vsk->local_addr.svm_cid = dst.svm_cid; 1599 1600 if (space_available) 1601 sk->sk_write_space(sk); 1602 1603 switch (sk->sk_state) { 1604 case TCP_LISTEN: 1605 virtio_transport_recv_listen(sk, skb, t); 1606 kfree_skb(skb); 1607 break; 1608 case TCP_SYN_SENT: 1609 virtio_transport_recv_connecting(sk, skb); 1610 kfree_skb(skb); 1611 break; 1612 case TCP_ESTABLISHED: 1613 virtio_transport_recv_connected(sk, skb); 1614 break; 1615 case TCP_CLOSING: 1616 virtio_transport_recv_disconnecting(sk, skb); 1617 kfree_skb(skb); 1618 break; 1619 default: 1620 (void)virtio_transport_reset_no_sock(t, skb); 1621 kfree_skb(skb); 1622 break; 1623 } 1624 1625 release_sock(sk); 1626 1627 /* Release refcnt obtained when we fetched this socket out of the 1628 * bound or connected list. 1629 */ 1630 sock_put(sk); 1631 return; 1632 1633free_pkt: 1634 kfree_skb(skb); 1635} 1636EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt); 1637 1638/* Remove skbs found in a queue that have a vsk that matches. 1639 * 1640 * Each skb is freed. 1641 * 1642 * Returns the count of skbs that were reply packets. 1643 */ 1644int virtio_transport_purge_skbs(void *vsk, struct sk_buff_head *queue) 1645{ 1646 struct sk_buff_head freeme; 1647 struct sk_buff *skb, *tmp; 1648 int cnt = 0; 1649 1650 skb_queue_head_init(&freeme); 1651 1652 spin_lock_bh(&queue->lock); 1653 skb_queue_walk_safe(queue, skb, tmp) { 1654 if (vsock_sk(skb->sk) != vsk) 1655 continue; 1656 1657 __skb_unlink(skb, queue); 1658 __skb_queue_tail(&freeme, skb); 1659 1660 if (virtio_vsock_skb_reply(skb)) 1661 cnt++; 1662 } 1663 spin_unlock_bh(&queue->lock); 1664 1665 __skb_queue_purge(&freeme); 1666 1667 return cnt; 1668} 1669EXPORT_SYMBOL_GPL(virtio_transport_purge_skbs); 1670 1671int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t recv_actor) 1672{ 1673 struct virtio_vsock_sock *vvs = vsk->trans; 1674 struct sock *sk = sk_vsock(vsk); 1675 struct sk_buff *skb; 1676 int off = 0; 1677 int err; 1678 1679 spin_lock_bh(&vvs->rx_lock); 1680 /* Use __skb_recv_datagram() for race-free handling of the receive. It 1681 * works for types other than dgrams. 1682 */ 1683 skb = __skb_recv_datagram(sk, &vvs->rx_queue, MSG_DONTWAIT, &off, &err); 1684 spin_unlock_bh(&vvs->rx_lock); 1685 1686 if (!skb) 1687 return err; 1688 1689 return recv_actor(sk, skb); 1690} 1691EXPORT_SYMBOL_GPL(virtio_transport_read_skb); 1692 1693int virtio_transport_notify_set_rcvlowat(struct vsock_sock *vsk, int val) 1694{ 1695 struct virtio_vsock_sock *vvs = vsk->trans; 1696 bool send_update; 1697 1698 spin_lock_bh(&vvs->rx_lock); 1699 1700 /* If number of available bytes is less than new SO_RCVLOWAT value, 1701 * kick sender to send more data, because sender may sleep in its 1702 * 'send()' syscall waiting for enough space at our side. Also 1703 * don't send credit update when peer already knows actual value - 1704 * such transmission will be useless. 1705 */ 1706 send_update = (vvs->rx_bytes < val) && 1707 (vvs->fwd_cnt != vvs->last_fwd_cnt); 1708 1709 spin_unlock_bh(&vvs->rx_lock); 1710 1711 if (send_update) { 1712 int err; 1713 1714 err = virtio_transport_send_credit_update(vsk); 1715 if (err < 0) 1716 return err; 1717 } 1718 1719 return 0; 1720} 1721EXPORT_SYMBOL_GPL(virtio_transport_notify_set_rcvlowat); 1722 1723MODULE_LICENSE("GPL v2"); 1724MODULE_AUTHOR("Asias He"); 1725MODULE_DESCRIPTION("common code for virtio vsock"); 1726