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 29 static void virtio_transport_cancel_close_work(struct vsock_sock *vsk, 30 bool cancel_timeout); 31 static s64 virtio_transport_has_space(struct virtio_vsock_sock *vvs); 32 33 static const struct virtio_transport * 34 virtio_transport_get_ops(struct vsock_sock *vsk) 35 { 36 const struct vsock_transport *t = vsock_core_get_transport(vsk); 37 38 if (WARN_ON(!t)) 39 return NULL; 40 41 return container_of(t, struct virtio_transport, transport); 42 } 43 44 static bool virtio_transport_can_zcopy(const struct virtio_transport *t_ops, 45 struct virtio_vsock_pkt_info *info, 46 size_t pkt_len) 47 { 48 struct iov_iter *iov_iter; 49 50 if (!info->msg) 51 return false; 52 53 iov_iter = &info->msg->msg_iter; 54 55 if (iov_iter->iov_offset) 56 return false; 57 58 /* We can't send whole iov. */ 59 if (iov_iter->count > pkt_len) 60 return false; 61 62 /* Check that transport can send data in zerocopy mode. */ 63 t_ops = virtio_transport_get_ops(info->vsk); 64 65 if (t_ops->can_msgzerocopy) { 66 int pages_to_send = iov_iter_npages(iov_iter, MAX_SKB_FRAGS); 67 68 /* +1 is for packet header. */ 69 return t_ops->can_msgzerocopy(pages_to_send + 1); 70 } 71 72 return true; 73 } 74 75 static int virtio_transport_init_zcopy_skb(struct vsock_sock *vsk, 76 struct sk_buff *skb, 77 struct msghdr *msg, 78 bool zerocopy) 79 { 80 struct ubuf_info *uarg; 81 82 if (msg->msg_ubuf) { 83 uarg = msg->msg_ubuf; 84 net_zcopy_get(uarg); 85 } else { 86 struct iov_iter *iter = &msg->msg_iter; 87 struct ubuf_info_msgzc *uarg_zc; 88 89 uarg = msg_zerocopy_realloc(sk_vsock(vsk), 90 iter->count, 91 NULL, false); 92 if (!uarg) 93 return -1; 94 95 uarg_zc = uarg_to_msgzc(uarg); 96 uarg_zc->zerocopy = zerocopy ? 1 : 0; 97 } 98 99 skb_zcopy_init(skb, uarg); 100 101 return 0; 102 } 103 104 static int virtio_transport_fill_skb(struct sk_buff *skb, 105 struct virtio_vsock_pkt_info *info, 106 size_t len, 107 bool zcopy) 108 { 109 struct msghdr *msg = info->msg; 110 111 if (zcopy) 112 return __zerocopy_sg_from_iter(msg, NULL, skb, 113 &msg->msg_iter, len, NULL); 114 115 virtio_vsock_skb_put(skb, len); 116 return skb_copy_datagram_from_iter_full(skb, 0, &msg->msg_iter, len); 117 } 118 119 static void virtio_transport_init_hdr(struct sk_buff *skb, 120 struct virtio_vsock_pkt_info *info, 121 size_t payload_len, 122 u32 src_cid, 123 u32 src_port, 124 u32 dst_cid, 125 u32 dst_port) 126 { 127 struct virtio_vsock_hdr *hdr; 128 129 hdr = virtio_vsock_hdr(skb); 130 hdr->type = cpu_to_le16(info->type); 131 hdr->op = cpu_to_le16(info->op); 132 hdr->src_cid = cpu_to_le64(src_cid); 133 hdr->dst_cid = cpu_to_le64(dst_cid); 134 hdr->src_port = cpu_to_le32(src_port); 135 hdr->dst_port = cpu_to_le32(dst_port); 136 hdr->flags = cpu_to_le32(info->flags); 137 hdr->len = cpu_to_le32(payload_len); 138 hdr->buf_alloc = cpu_to_le32(0); 139 hdr->fwd_cnt = cpu_to_le32(0); 140 } 141 142 static void virtio_transport_copy_nonlinear_skb(const struct sk_buff *skb, 143 void *dst, 144 size_t len) 145 { 146 struct iov_iter iov_iter = { 0 }; 147 struct kvec kvec; 148 size_t to_copy; 149 150 kvec.iov_base = dst; 151 kvec.iov_len = len; 152 153 iov_iter.iter_type = ITER_KVEC; 154 iov_iter.kvec = &kvec; 155 iov_iter.nr_segs = 1; 156 157 to_copy = min_t(size_t, len, skb->len); 158 159 skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset, 160 &iov_iter, to_copy); 161 } 162 163 /* Packet capture */ 164 static struct sk_buff *virtio_transport_build_skb(void *opaque) 165 { 166 struct virtio_vsock_hdr *pkt_hdr; 167 struct sk_buff *pkt = opaque; 168 struct af_vsockmon_hdr *hdr; 169 struct sk_buff *skb; 170 size_t payload_len; 171 172 /* A packet could be split to fit the RX buffer, so we can retrieve 173 * the payload length from the header and the buffer pointer taking 174 * care of the offset in the original packet. 175 */ 176 pkt_hdr = virtio_vsock_hdr(pkt); 177 payload_len = pkt->len; 178 179 skb = alloc_skb(sizeof(*hdr) + sizeof(*pkt_hdr) + payload_len, 180 GFP_ATOMIC); 181 if (!skb) 182 return NULL; 183 184 hdr = skb_put(skb, sizeof(*hdr)); 185 186 /* pkt->hdr is little-endian so no need to byteswap here */ 187 hdr->src_cid = pkt_hdr->src_cid; 188 hdr->src_port = pkt_hdr->src_port; 189 hdr->dst_cid = pkt_hdr->dst_cid; 190 hdr->dst_port = pkt_hdr->dst_port; 191 192 hdr->transport = cpu_to_le16(AF_VSOCK_TRANSPORT_VIRTIO); 193 hdr->len = cpu_to_le16(sizeof(*pkt_hdr)); 194 memset(hdr->reserved, 0, sizeof(hdr->reserved)); 195 196 switch (le16_to_cpu(pkt_hdr->op)) { 197 case VIRTIO_VSOCK_OP_REQUEST: 198 case VIRTIO_VSOCK_OP_RESPONSE: 199 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONNECT); 200 break; 201 case VIRTIO_VSOCK_OP_RST: 202 case VIRTIO_VSOCK_OP_SHUTDOWN: 203 hdr->op = cpu_to_le16(AF_VSOCK_OP_DISCONNECT); 204 break; 205 case VIRTIO_VSOCK_OP_RW: 206 hdr->op = cpu_to_le16(AF_VSOCK_OP_PAYLOAD); 207 break; 208 case VIRTIO_VSOCK_OP_CREDIT_UPDATE: 209 case VIRTIO_VSOCK_OP_CREDIT_REQUEST: 210 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONTROL); 211 break; 212 default: 213 hdr->op = cpu_to_le16(AF_VSOCK_OP_UNKNOWN); 214 break; 215 } 216 217 skb_put_data(skb, pkt_hdr, sizeof(*pkt_hdr)); 218 219 if (payload_len) { 220 if (skb_is_nonlinear(pkt)) { 221 void *data = skb_put(skb, payload_len); 222 223 virtio_transport_copy_nonlinear_skb(pkt, data, payload_len); 224 } else { 225 skb_put_data(skb, pkt->data, payload_len); 226 } 227 } 228 229 return skb; 230 } 231 232 void virtio_transport_deliver_tap_pkt(struct sk_buff *skb) 233 { 234 if (virtio_vsock_skb_tap_delivered(skb)) 235 return; 236 237 vsock_deliver_tap(virtio_transport_build_skb, skb); 238 virtio_vsock_skb_set_tap_delivered(skb); 239 } 240 EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt); 241 242 static u16 virtio_transport_get_type(struct sock *sk) 243 { 244 if (sk->sk_type == SOCK_STREAM) 245 return VIRTIO_VSOCK_TYPE_STREAM; 246 else 247 return VIRTIO_VSOCK_TYPE_SEQPACKET; 248 } 249 250 /* Returns new sk_buff on success, otherwise returns NULL. */ 251 static struct sk_buff *virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *info, 252 size_t payload_len, 253 bool zcopy, 254 u32 src_cid, 255 u32 src_port, 256 u32 dst_cid, 257 u32 dst_port) 258 { 259 struct vsock_sock *vsk; 260 struct sk_buff *skb; 261 size_t skb_len; 262 263 skb_len = VIRTIO_VSOCK_SKB_HEADROOM; 264 265 if (!zcopy) 266 skb_len += payload_len; 267 268 skb = virtio_vsock_alloc_skb(skb_len, GFP_KERNEL); 269 if (!skb) 270 return NULL; 271 272 virtio_transport_init_hdr(skb, info, payload_len, src_cid, src_port, 273 dst_cid, dst_port); 274 275 vsk = info->vsk; 276 277 /* If 'vsk' != NULL then payload is always present, so we 278 * will never call '__zerocopy_sg_from_iter()' below without 279 * setting skb owner in 'skb_set_owner_w()'. The only case 280 * when 'vsk' == NULL is VIRTIO_VSOCK_OP_RST control message 281 * without payload. 282 */ 283 WARN_ON_ONCE(!(vsk && (info->msg && payload_len)) && zcopy); 284 285 /* Set owner here, because '__zerocopy_sg_from_iter()' uses 286 * owner of skb without check to update 'sk_wmem_alloc'. 287 */ 288 if (vsk) 289 skb_set_owner_w(skb, sk_vsock(vsk)); 290 291 if (info->msg && payload_len > 0) { 292 int err; 293 294 err = virtio_transport_fill_skb(skb, info, payload_len, zcopy); 295 if (err) 296 goto out; 297 298 if (msg_data_left(info->msg) == 0 && 299 info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) { 300 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 301 302 hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM); 303 304 if (info->msg->msg_flags & MSG_EOR) 305 hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR); 306 } 307 } 308 309 if (info->reply) 310 virtio_vsock_skb_set_reply(skb); 311 312 trace_virtio_transport_alloc_pkt(src_cid, src_port, 313 dst_cid, dst_port, 314 payload_len, 315 info->type, 316 info->op, 317 info->flags, 318 zcopy); 319 320 return skb; 321 out: 322 kfree_skb(skb); 323 return NULL; 324 } 325 326 /* This function can only be used on connecting/connected sockets, 327 * since a socket assigned to a transport is required. 328 * 329 * Do not use on listener sockets! 330 */ 331 static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, 332 struct virtio_vsock_pkt_info *info) 333 { 334 u32 max_skb_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE; 335 u32 src_cid, src_port, dst_cid, dst_port; 336 const struct virtio_transport *t_ops; 337 struct virtio_vsock_sock *vvs; 338 u32 pkt_len = info->pkt_len; 339 bool can_zcopy = false; 340 u32 rest_len; 341 int ret; 342 343 info->type = virtio_transport_get_type(sk_vsock(vsk)); 344 345 t_ops = virtio_transport_get_ops(vsk); 346 if (unlikely(!t_ops)) 347 return -EFAULT; 348 349 src_cid = t_ops->transport.get_local_cid(); 350 src_port = vsk->local_addr.svm_port; 351 if (!info->remote_cid) { 352 dst_cid = vsk->remote_addr.svm_cid; 353 dst_port = vsk->remote_addr.svm_port; 354 } else { 355 dst_cid = info->remote_cid; 356 dst_port = info->remote_port; 357 } 358 359 vvs = vsk->trans; 360 361 /* virtio_transport_get_credit might return less than pkt_len credit */ 362 pkt_len = virtio_transport_get_credit(vvs, pkt_len); 363 364 /* Do not send zero length OP_RW pkt */ 365 if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW) 366 return pkt_len; 367 368 if (info->msg) { 369 /* If zerocopy is not enabled by 'setsockopt()', we behave as 370 * there is no MSG_ZEROCOPY flag set. 371 */ 372 if (!sock_flag(sk_vsock(vsk), SOCK_ZEROCOPY)) 373 info->msg->msg_flags &= ~MSG_ZEROCOPY; 374 375 if (info->msg->msg_flags & MSG_ZEROCOPY) 376 can_zcopy = virtio_transport_can_zcopy(t_ops, info, pkt_len); 377 378 if (can_zcopy) 379 max_skb_len = min_t(u32, VIRTIO_VSOCK_MAX_PKT_BUF_SIZE, 380 (MAX_SKB_FRAGS * PAGE_SIZE)); 381 } 382 383 rest_len = pkt_len; 384 385 do { 386 struct sk_buff *skb; 387 size_t skb_len; 388 389 skb_len = min(max_skb_len, rest_len); 390 391 skb = virtio_transport_alloc_skb(info, skb_len, can_zcopy, 392 src_cid, src_port, 393 dst_cid, dst_port); 394 if (!skb) { 395 ret = -ENOMEM; 396 break; 397 } 398 399 /* We process buffer part by part, allocating skb on 400 * each iteration. If this is last skb for this buffer 401 * and MSG_ZEROCOPY mode is in use - we must allocate 402 * completion for the current syscall. 403 */ 404 if (info->msg && info->msg->msg_flags & MSG_ZEROCOPY && 405 skb_len == rest_len && info->op == VIRTIO_VSOCK_OP_RW) { 406 if (virtio_transport_init_zcopy_skb(vsk, skb, 407 info->msg, 408 can_zcopy)) { 409 kfree_skb(skb); 410 ret = -ENOMEM; 411 break; 412 } 413 } 414 415 virtio_transport_inc_tx_pkt(vvs, skb); 416 417 ret = t_ops->send_pkt(skb); 418 if (ret < 0) 419 break; 420 421 /* Both virtio and vhost 'send_pkt()' returns 'skb_len', 422 * but for reliability use 'ret' instead of 'skb_len'. 423 * Also if partial send happens (e.g. 'ret' != 'skb_len') 424 * somehow, we break this loop, but account such returned 425 * value in 'virtio_transport_put_credit()'. 426 */ 427 rest_len -= ret; 428 429 if (WARN_ONCE(ret != skb_len, 430 "'send_pkt()' returns %i, but %zu expected\n", 431 ret, skb_len)) 432 break; 433 } while (rest_len); 434 435 virtio_transport_put_credit(vvs, rest_len); 436 437 /* Return number of bytes, if any data has been sent. */ 438 if (rest_len != pkt_len) 439 ret = pkt_len - rest_len; 440 441 return ret; 442 } 443 444 static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs, 445 u32 len) 446 { 447 if (vvs->buf_used + len > vvs->buf_alloc) 448 return false; 449 450 vvs->rx_bytes += len; 451 vvs->buf_used += len; 452 return true; 453 } 454 455 static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs, 456 u32 bytes_read, u32 bytes_dequeued) 457 { 458 vvs->rx_bytes -= bytes_read; 459 vvs->buf_used -= bytes_dequeued; 460 vvs->fwd_cnt += bytes_dequeued; 461 } 462 463 void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct sk_buff *skb) 464 { 465 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 466 467 spin_lock_bh(&vvs->rx_lock); 468 vvs->last_fwd_cnt = vvs->fwd_cnt; 469 hdr->fwd_cnt = cpu_to_le32(vvs->fwd_cnt); 470 hdr->buf_alloc = cpu_to_le32(vvs->buf_alloc); 471 spin_unlock_bh(&vvs->rx_lock); 472 } 473 EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt); 474 475 void virtio_transport_consume_skb_sent(struct sk_buff *skb, bool consume) 476 { 477 struct sock *s = skb->sk; 478 479 if (s && skb->len) { 480 struct vsock_sock *vs = vsock_sk(s); 481 struct virtio_vsock_sock *vvs; 482 483 vvs = vs->trans; 484 485 spin_lock_bh(&vvs->tx_lock); 486 vvs->bytes_unsent -= skb->len; 487 spin_unlock_bh(&vvs->tx_lock); 488 } 489 490 if (consume) 491 consume_skb(skb); 492 } 493 EXPORT_SYMBOL_GPL(virtio_transport_consume_skb_sent); 494 495 u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit) 496 { 497 u32 ret; 498 499 if (!credit) 500 return 0; 501 502 spin_lock_bh(&vvs->tx_lock); 503 ret = min_t(u32, credit, virtio_transport_has_space(vvs)); 504 vvs->tx_cnt += ret; 505 vvs->bytes_unsent += ret; 506 spin_unlock_bh(&vvs->tx_lock); 507 508 return ret; 509 } 510 EXPORT_SYMBOL_GPL(virtio_transport_get_credit); 511 512 void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit) 513 { 514 if (!credit) 515 return; 516 517 spin_lock_bh(&vvs->tx_lock); 518 vvs->tx_cnt -= credit; 519 vvs->bytes_unsent -= credit; 520 spin_unlock_bh(&vvs->tx_lock); 521 } 522 EXPORT_SYMBOL_GPL(virtio_transport_put_credit); 523 524 static int virtio_transport_send_credit_update(struct vsock_sock *vsk) 525 { 526 struct virtio_vsock_pkt_info info = { 527 .op = VIRTIO_VSOCK_OP_CREDIT_UPDATE, 528 .vsk = vsk, 529 }; 530 531 return virtio_transport_send_pkt_info(vsk, &info); 532 } 533 534 static ssize_t 535 virtio_transport_stream_do_peek(struct vsock_sock *vsk, 536 struct msghdr *msg, 537 size_t len) 538 { 539 struct virtio_vsock_sock *vvs = vsk->trans; 540 struct sk_buff *skb; 541 size_t total = 0; 542 int err; 543 544 spin_lock_bh(&vvs->rx_lock); 545 546 skb_queue_walk(&vvs->rx_queue, skb) { 547 size_t bytes; 548 549 bytes = len - total; 550 if (bytes > skb->len) 551 bytes = skb->len; 552 553 spin_unlock_bh(&vvs->rx_lock); 554 555 /* sk_lock is held by caller so no one else can dequeue. 556 * Unlock rx_lock since skb_copy_datagram_iter() may sleep. 557 */ 558 err = skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset, 559 &msg->msg_iter, bytes); 560 if (err) 561 goto out; 562 563 total += bytes; 564 565 spin_lock_bh(&vvs->rx_lock); 566 567 if (total == len) 568 break; 569 } 570 571 spin_unlock_bh(&vvs->rx_lock); 572 573 return total; 574 575 out: 576 if (total) 577 err = total; 578 return err; 579 } 580 581 static ssize_t 582 virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, 583 struct msghdr *msg, 584 size_t len) 585 { 586 struct virtio_vsock_sock *vvs = vsk->trans; 587 struct sk_buff *skb; 588 u32 fwd_cnt_delta; 589 bool low_rx_bytes; 590 int err = -EFAULT; 591 size_t total = 0; 592 u32 free_space; 593 594 spin_lock_bh(&vvs->rx_lock); 595 596 if (WARN_ONCE(skb_queue_empty(&vvs->rx_queue) && vvs->rx_bytes, 597 "rx_queue is empty, but rx_bytes is non-zero\n")) { 598 spin_unlock_bh(&vvs->rx_lock); 599 return err; 600 } 601 602 while (total < len && !skb_queue_empty(&vvs->rx_queue)) { 603 size_t bytes, dequeued = 0; 604 605 skb = skb_peek(&vvs->rx_queue); 606 607 bytes = min_t(size_t, len - total, 608 skb->len - VIRTIO_VSOCK_SKB_CB(skb)->offset); 609 610 /* sk_lock is held by caller so no one else can dequeue. 611 * Unlock rx_lock since skb_copy_datagram_iter() may sleep. 612 */ 613 spin_unlock_bh(&vvs->rx_lock); 614 615 err = skb_copy_datagram_iter(skb, 616 VIRTIO_VSOCK_SKB_CB(skb)->offset, 617 &msg->msg_iter, bytes); 618 if (err) 619 goto out; 620 621 spin_lock_bh(&vvs->rx_lock); 622 623 total += bytes; 624 625 VIRTIO_VSOCK_SKB_CB(skb)->offset += bytes; 626 627 if (skb->len == VIRTIO_VSOCK_SKB_CB(skb)->offset) { 628 dequeued = le32_to_cpu(virtio_vsock_hdr(skb)->len); 629 __skb_unlink(skb, &vvs->rx_queue); 630 consume_skb(skb); 631 } 632 633 virtio_transport_dec_rx_pkt(vvs, bytes, dequeued); 634 } 635 636 fwd_cnt_delta = vvs->fwd_cnt - vvs->last_fwd_cnt; 637 free_space = vvs->buf_alloc - fwd_cnt_delta; 638 low_rx_bytes = (vvs->rx_bytes < 639 sock_rcvlowat(sk_vsock(vsk), 0, INT_MAX)); 640 641 spin_unlock_bh(&vvs->rx_lock); 642 643 /* To reduce the number of credit update messages, 644 * don't update credits as long as lots of space is available. 645 * Note: the limit chosen here is arbitrary. Setting the limit 646 * too high causes extra messages. Too low causes transmitter 647 * stalls. As stalls are in theory more expensive than extra 648 * messages, we set the limit to a high value. TODO: experiment 649 * with different values. Also send credit update message when 650 * number of bytes in rx queue is not enough to wake up reader. 651 */ 652 if (fwd_cnt_delta && 653 (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE || low_rx_bytes)) 654 virtio_transport_send_credit_update(vsk); 655 656 return total; 657 658 out: 659 if (total) 660 err = total; 661 return err; 662 } 663 664 static ssize_t 665 virtio_transport_seqpacket_do_peek(struct vsock_sock *vsk, 666 struct msghdr *msg) 667 { 668 struct virtio_vsock_sock *vvs = vsk->trans; 669 struct sk_buff *skb; 670 size_t total, len; 671 672 spin_lock_bh(&vvs->rx_lock); 673 674 if (!vvs->msg_count) { 675 spin_unlock_bh(&vvs->rx_lock); 676 return 0; 677 } 678 679 total = 0; 680 len = msg_data_left(msg); 681 682 skb_queue_walk(&vvs->rx_queue, skb) { 683 struct virtio_vsock_hdr *hdr; 684 685 if (total < len) { 686 size_t bytes; 687 int err; 688 689 bytes = len - total; 690 if (bytes > skb->len) 691 bytes = skb->len; 692 693 spin_unlock_bh(&vvs->rx_lock); 694 695 /* sk_lock is held by caller so no one else can dequeue. 696 * Unlock rx_lock since skb_copy_datagram_iter() may sleep. 697 */ 698 err = skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset, 699 &msg->msg_iter, bytes); 700 if (err) 701 return err; 702 703 spin_lock_bh(&vvs->rx_lock); 704 } 705 706 total += skb->len; 707 hdr = virtio_vsock_hdr(skb); 708 709 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) { 710 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR) 711 msg->msg_flags |= MSG_EOR; 712 713 break; 714 } 715 } 716 717 spin_unlock_bh(&vvs->rx_lock); 718 719 return total; 720 } 721 722 static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk, 723 struct msghdr *msg, 724 int flags) 725 { 726 struct virtio_vsock_sock *vvs = vsk->trans; 727 int dequeued_len = 0; 728 size_t user_buf_len = msg_data_left(msg); 729 bool msg_ready = false; 730 struct sk_buff *skb; 731 732 spin_lock_bh(&vvs->rx_lock); 733 734 if (vvs->msg_count == 0) { 735 spin_unlock_bh(&vvs->rx_lock); 736 return 0; 737 } 738 739 while (!msg_ready) { 740 struct virtio_vsock_hdr *hdr; 741 size_t pkt_len; 742 743 skb = __skb_dequeue(&vvs->rx_queue); 744 if (!skb) 745 break; 746 hdr = virtio_vsock_hdr(skb); 747 pkt_len = (size_t)le32_to_cpu(hdr->len); 748 749 if (dequeued_len >= 0) { 750 size_t bytes_to_copy; 751 752 bytes_to_copy = min(user_buf_len, pkt_len); 753 754 if (bytes_to_copy) { 755 int err; 756 757 /* sk_lock is held by caller so no one else can dequeue. 758 * Unlock rx_lock since skb_copy_datagram_iter() may sleep. 759 */ 760 spin_unlock_bh(&vvs->rx_lock); 761 762 err = skb_copy_datagram_iter(skb, 0, 763 &msg->msg_iter, 764 bytes_to_copy); 765 if (err) { 766 /* Copy of message failed. Rest of 767 * fragments will be freed without copy. 768 */ 769 dequeued_len = err; 770 } else { 771 user_buf_len -= bytes_to_copy; 772 } 773 774 spin_lock_bh(&vvs->rx_lock); 775 } 776 777 if (dequeued_len >= 0) 778 dequeued_len += pkt_len; 779 } 780 781 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) { 782 msg_ready = true; 783 vvs->msg_count--; 784 785 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR) 786 msg->msg_flags |= MSG_EOR; 787 } 788 789 virtio_transport_dec_rx_pkt(vvs, pkt_len, pkt_len); 790 kfree_skb(skb); 791 } 792 793 spin_unlock_bh(&vvs->rx_lock); 794 795 virtio_transport_send_credit_update(vsk); 796 797 return dequeued_len; 798 } 799 800 ssize_t 801 virtio_transport_stream_dequeue(struct vsock_sock *vsk, 802 struct msghdr *msg, 803 size_t len, int flags) 804 { 805 if (flags & MSG_PEEK) 806 return virtio_transport_stream_do_peek(vsk, msg, len); 807 else 808 return virtio_transport_stream_do_dequeue(vsk, msg, len); 809 } 810 EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue); 811 812 ssize_t 813 virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk, 814 struct msghdr *msg, 815 int flags) 816 { 817 if (flags & MSG_PEEK) 818 return virtio_transport_seqpacket_do_peek(vsk, msg); 819 else 820 return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags); 821 } 822 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue); 823 824 static u32 virtio_transport_tx_buf_size(struct virtio_vsock_sock *vvs) 825 { 826 /* The peer advertises its receive buffer via peer_buf_alloc, but we 827 * cap it to our local buf_alloc so a remote peer cannot force us to 828 * queue more data than our own buffer configuration allows. 829 */ 830 return min(vvs->peer_buf_alloc, vvs->buf_alloc); 831 } 832 833 int 834 virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk, 835 struct msghdr *msg, 836 size_t len) 837 { 838 struct virtio_vsock_sock *vvs = vsk->trans; 839 840 spin_lock_bh(&vvs->tx_lock); 841 842 if (len > virtio_transport_tx_buf_size(vvs)) { 843 spin_unlock_bh(&vvs->tx_lock); 844 return -EMSGSIZE; 845 } 846 847 spin_unlock_bh(&vvs->tx_lock); 848 849 return virtio_transport_stream_enqueue(vsk, msg, len); 850 } 851 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_enqueue); 852 853 int 854 virtio_transport_dgram_dequeue(struct vsock_sock *vsk, 855 struct msghdr *msg, 856 size_t len, int flags) 857 { 858 return -EOPNOTSUPP; 859 } 860 EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue); 861 862 s64 virtio_transport_stream_has_data(struct vsock_sock *vsk) 863 { 864 struct virtio_vsock_sock *vvs = vsk->trans; 865 s64 bytes; 866 867 spin_lock_bh(&vvs->rx_lock); 868 bytes = vvs->rx_bytes; 869 spin_unlock_bh(&vvs->rx_lock); 870 871 return bytes; 872 } 873 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data); 874 875 u32 virtio_transport_seqpacket_has_data(struct vsock_sock *vsk) 876 { 877 struct virtio_vsock_sock *vvs = vsk->trans; 878 u32 msg_count; 879 880 spin_lock_bh(&vvs->rx_lock); 881 msg_count = vvs->msg_count; 882 spin_unlock_bh(&vvs->rx_lock); 883 884 return msg_count; 885 } 886 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_has_data); 887 888 static s64 virtio_transport_has_space(struct virtio_vsock_sock *vvs) 889 { 890 s64 bytes; 891 892 /* Use s64 arithmetic so if the peer shrinks peer_buf_alloc while 893 * we have bytes in flight (tx_cnt - peer_fwd_cnt), the subtraction 894 * does not underflow. 895 */ 896 bytes = (s64)virtio_transport_tx_buf_size(vvs) - 897 (vvs->tx_cnt - vvs->peer_fwd_cnt); 898 if (bytes < 0) 899 bytes = 0; 900 901 return bytes; 902 } 903 904 s64 virtio_transport_stream_has_space(struct vsock_sock *vsk) 905 { 906 struct virtio_vsock_sock *vvs = vsk->trans; 907 s64 bytes; 908 909 spin_lock_bh(&vvs->tx_lock); 910 bytes = virtio_transport_has_space(vvs); 911 spin_unlock_bh(&vvs->tx_lock); 912 913 return bytes; 914 } 915 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space); 916 917 int virtio_transport_do_socket_init(struct vsock_sock *vsk, 918 struct vsock_sock *psk) 919 { 920 struct virtio_vsock_sock *vvs; 921 922 vvs = kzalloc(sizeof(*vvs), GFP_KERNEL); 923 if (!vvs) 924 return -ENOMEM; 925 926 vsk->trans = vvs; 927 vvs->vsk = vsk; 928 if (psk && psk->trans) { 929 struct virtio_vsock_sock *ptrans = psk->trans; 930 931 vvs->peer_buf_alloc = ptrans->peer_buf_alloc; 932 } 933 934 if (vsk->buffer_size > VIRTIO_VSOCK_MAX_BUF_SIZE) 935 vsk->buffer_size = VIRTIO_VSOCK_MAX_BUF_SIZE; 936 937 vvs->buf_alloc = vsk->buffer_size; 938 939 spin_lock_init(&vvs->rx_lock); 940 spin_lock_init(&vvs->tx_lock); 941 skb_queue_head_init(&vvs->rx_queue); 942 943 return 0; 944 } 945 EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init); 946 947 /* sk_lock held by the caller */ 948 void virtio_transport_notify_buffer_size(struct vsock_sock *vsk, u64 *val) 949 { 950 struct virtio_vsock_sock *vvs = vsk->trans; 951 952 if (*val > VIRTIO_VSOCK_MAX_BUF_SIZE) 953 *val = VIRTIO_VSOCK_MAX_BUF_SIZE; 954 955 vvs->buf_alloc = *val; 956 957 virtio_transport_send_credit_update(vsk); 958 } 959 EXPORT_SYMBOL_GPL(virtio_transport_notify_buffer_size); 960 961 int 962 virtio_transport_notify_poll_in(struct vsock_sock *vsk, 963 size_t target, 964 bool *data_ready_now) 965 { 966 *data_ready_now = vsock_stream_has_data(vsk) >= target; 967 968 return 0; 969 } 970 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in); 971 972 int 973 virtio_transport_notify_poll_out(struct vsock_sock *vsk, 974 size_t target, 975 bool *space_avail_now) 976 { 977 s64 free_space; 978 979 free_space = vsock_stream_has_space(vsk); 980 if (free_space > 0) 981 *space_avail_now = true; 982 else if (free_space == 0) 983 *space_avail_now = false; 984 985 return 0; 986 } 987 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out); 988 989 int virtio_transport_notify_recv_init(struct vsock_sock *vsk, 990 size_t target, struct vsock_transport_recv_notify_data *data) 991 { 992 return 0; 993 } 994 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init); 995 996 int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk, 997 size_t target, struct vsock_transport_recv_notify_data *data) 998 { 999 return 0; 1000 } 1001 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block); 1002 1003 int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk, 1004 size_t target, struct vsock_transport_recv_notify_data *data) 1005 { 1006 return 0; 1007 } 1008 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue); 1009 1010 int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk, 1011 size_t target, ssize_t copied, bool data_read, 1012 struct vsock_transport_recv_notify_data *data) 1013 { 1014 return 0; 1015 } 1016 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue); 1017 1018 int virtio_transport_notify_send_init(struct vsock_sock *vsk, 1019 struct vsock_transport_send_notify_data *data) 1020 { 1021 return 0; 1022 } 1023 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init); 1024 1025 int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk, 1026 struct vsock_transport_send_notify_data *data) 1027 { 1028 return 0; 1029 } 1030 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block); 1031 1032 int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk, 1033 struct vsock_transport_send_notify_data *data) 1034 { 1035 return 0; 1036 } 1037 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue); 1038 1039 int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk, 1040 ssize_t written, struct vsock_transport_send_notify_data *data) 1041 { 1042 return 0; 1043 } 1044 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue); 1045 1046 u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk) 1047 { 1048 return vsk->buffer_size; 1049 } 1050 EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat); 1051 1052 bool virtio_transport_stream_is_active(struct vsock_sock *vsk) 1053 { 1054 return true; 1055 } 1056 EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active); 1057 1058 bool virtio_transport_stream_allow(u32 cid, u32 port) 1059 { 1060 return true; 1061 } 1062 EXPORT_SYMBOL_GPL(virtio_transport_stream_allow); 1063 1064 int virtio_transport_dgram_bind(struct vsock_sock *vsk, 1065 struct sockaddr_vm *addr) 1066 { 1067 return -EOPNOTSUPP; 1068 } 1069 EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind); 1070 1071 bool virtio_transport_dgram_allow(u32 cid, u32 port) 1072 { 1073 return false; 1074 } 1075 EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow); 1076 1077 int virtio_transport_connect(struct vsock_sock *vsk) 1078 { 1079 struct virtio_vsock_pkt_info info = { 1080 .op = VIRTIO_VSOCK_OP_REQUEST, 1081 .vsk = vsk, 1082 }; 1083 1084 return virtio_transport_send_pkt_info(vsk, &info); 1085 } 1086 EXPORT_SYMBOL_GPL(virtio_transport_connect); 1087 1088 int virtio_transport_shutdown(struct vsock_sock *vsk, int mode) 1089 { 1090 struct virtio_vsock_pkt_info info = { 1091 .op = VIRTIO_VSOCK_OP_SHUTDOWN, 1092 .flags = (mode & RCV_SHUTDOWN ? 1093 VIRTIO_VSOCK_SHUTDOWN_RCV : 0) | 1094 (mode & SEND_SHUTDOWN ? 1095 VIRTIO_VSOCK_SHUTDOWN_SEND : 0), 1096 .vsk = vsk, 1097 }; 1098 1099 return virtio_transport_send_pkt_info(vsk, &info); 1100 } 1101 EXPORT_SYMBOL_GPL(virtio_transport_shutdown); 1102 1103 int 1104 virtio_transport_dgram_enqueue(struct vsock_sock *vsk, 1105 struct sockaddr_vm *remote_addr, 1106 struct msghdr *msg, 1107 size_t dgram_len) 1108 { 1109 return -EOPNOTSUPP; 1110 } 1111 EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue); 1112 1113 ssize_t 1114 virtio_transport_stream_enqueue(struct vsock_sock *vsk, 1115 struct msghdr *msg, 1116 size_t len) 1117 { 1118 struct virtio_vsock_pkt_info info = { 1119 .op = VIRTIO_VSOCK_OP_RW, 1120 .msg = msg, 1121 .pkt_len = len, 1122 .vsk = vsk, 1123 }; 1124 1125 return virtio_transport_send_pkt_info(vsk, &info); 1126 } 1127 EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue); 1128 1129 void virtio_transport_destruct(struct vsock_sock *vsk) 1130 { 1131 struct virtio_vsock_sock *vvs = vsk->trans; 1132 1133 virtio_transport_cancel_close_work(vsk, true); 1134 1135 kfree(vvs); 1136 vsk->trans = NULL; 1137 } 1138 EXPORT_SYMBOL_GPL(virtio_transport_destruct); 1139 1140 ssize_t virtio_transport_unsent_bytes(struct vsock_sock *vsk) 1141 { 1142 struct virtio_vsock_sock *vvs = vsk->trans; 1143 size_t ret; 1144 1145 spin_lock_bh(&vvs->tx_lock); 1146 ret = vvs->bytes_unsent; 1147 spin_unlock_bh(&vvs->tx_lock); 1148 1149 return ret; 1150 } 1151 EXPORT_SYMBOL_GPL(virtio_transport_unsent_bytes); 1152 1153 static int virtio_transport_reset(struct vsock_sock *vsk, 1154 struct sk_buff *skb) 1155 { 1156 struct virtio_vsock_pkt_info info = { 1157 .op = VIRTIO_VSOCK_OP_RST, 1158 .reply = !!skb, 1159 .vsk = vsk, 1160 }; 1161 1162 /* Send RST only if the original pkt is not a RST pkt */ 1163 if (skb && le16_to_cpu(virtio_vsock_hdr(skb)->op) == VIRTIO_VSOCK_OP_RST) 1164 return 0; 1165 1166 return virtio_transport_send_pkt_info(vsk, &info); 1167 } 1168 1169 /* Normally packets are associated with a socket. There may be no socket if an 1170 * attempt was made to connect to a socket that does not exist. 1171 */ 1172 static int virtio_transport_reset_no_sock(const struct virtio_transport *t, 1173 struct sk_buff *skb) 1174 { 1175 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1176 struct virtio_vsock_pkt_info info = { 1177 .op = VIRTIO_VSOCK_OP_RST, 1178 .type = le16_to_cpu(hdr->type), 1179 .reply = true, 1180 }; 1181 struct sk_buff *reply; 1182 1183 /* Send RST only if the original pkt is not a RST pkt */ 1184 if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST) 1185 return 0; 1186 1187 if (!t) 1188 return -ENOTCONN; 1189 1190 reply = virtio_transport_alloc_skb(&info, 0, false, 1191 le64_to_cpu(hdr->dst_cid), 1192 le32_to_cpu(hdr->dst_port), 1193 le64_to_cpu(hdr->src_cid), 1194 le32_to_cpu(hdr->src_port)); 1195 if (!reply) 1196 return -ENOMEM; 1197 1198 return t->send_pkt(reply); 1199 } 1200 1201 /* This function should be called with sk_lock held and SOCK_DONE set */ 1202 static void virtio_transport_remove_sock(struct vsock_sock *vsk) 1203 { 1204 struct virtio_vsock_sock *vvs = vsk->trans; 1205 1206 /* We don't need to take rx_lock, as the socket is closing and we are 1207 * removing it. 1208 */ 1209 __skb_queue_purge(&vvs->rx_queue); 1210 vsock_remove_sock(vsk); 1211 } 1212 1213 static void virtio_transport_cancel_close_work(struct vsock_sock *vsk, 1214 bool cancel_timeout) 1215 { 1216 struct sock *sk = sk_vsock(vsk); 1217 1218 if (vsk->close_work_scheduled && 1219 (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) { 1220 vsk->close_work_scheduled = false; 1221 1222 virtio_transport_remove_sock(vsk); 1223 1224 /* Release refcnt obtained when we scheduled the timeout */ 1225 sock_put(sk); 1226 } 1227 } 1228 1229 static void virtio_transport_do_close(struct vsock_sock *vsk, 1230 bool cancel_timeout) 1231 { 1232 struct sock *sk = sk_vsock(vsk); 1233 1234 sock_set_flag(sk, SOCK_DONE); 1235 vsk->peer_shutdown = SHUTDOWN_MASK; 1236 if (vsock_stream_has_data(vsk) <= 0) 1237 sk->sk_state = TCP_CLOSING; 1238 sk->sk_state_change(sk); 1239 1240 virtio_transport_cancel_close_work(vsk, cancel_timeout); 1241 } 1242 1243 static void virtio_transport_close_timeout(struct work_struct *work) 1244 { 1245 struct vsock_sock *vsk = 1246 container_of(work, struct vsock_sock, close_work.work); 1247 struct sock *sk = sk_vsock(vsk); 1248 1249 sock_hold(sk); 1250 lock_sock(sk); 1251 1252 if (!sock_flag(sk, SOCK_DONE)) { 1253 (void)virtio_transport_reset(vsk, NULL); 1254 1255 virtio_transport_do_close(vsk, false); 1256 } 1257 1258 vsk->close_work_scheduled = false; 1259 1260 release_sock(sk); 1261 sock_put(sk); 1262 } 1263 1264 /* User context, vsk->sk is locked */ 1265 static bool virtio_transport_close(struct vsock_sock *vsk) 1266 { 1267 struct sock *sk = &vsk->sk; 1268 1269 if (!(sk->sk_state == TCP_ESTABLISHED || 1270 sk->sk_state == TCP_CLOSING)) 1271 return true; 1272 1273 /* Already received SHUTDOWN from peer, reply with RST */ 1274 if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) { 1275 (void)virtio_transport_reset(vsk, NULL); 1276 return true; 1277 } 1278 1279 if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK) 1280 (void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK); 1281 1282 if (!(current->flags & PF_EXITING)) 1283 vsock_linger(sk); 1284 1285 if (sock_flag(sk, SOCK_DONE)) { 1286 return true; 1287 } 1288 1289 sock_hold(sk); 1290 INIT_DELAYED_WORK(&vsk->close_work, 1291 virtio_transport_close_timeout); 1292 vsk->close_work_scheduled = true; 1293 schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT); 1294 return false; 1295 } 1296 1297 void virtio_transport_release(struct vsock_sock *vsk) 1298 { 1299 struct sock *sk = &vsk->sk; 1300 bool remove_sock = true; 1301 1302 if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) 1303 remove_sock = virtio_transport_close(vsk); 1304 1305 if (remove_sock) { 1306 sock_set_flag(sk, SOCK_DONE); 1307 virtio_transport_remove_sock(vsk); 1308 } 1309 } 1310 EXPORT_SYMBOL_GPL(virtio_transport_release); 1311 1312 static int 1313 virtio_transport_recv_connecting(struct sock *sk, 1314 struct sk_buff *skb) 1315 { 1316 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1317 struct vsock_sock *vsk = vsock_sk(sk); 1318 int skerr; 1319 int err; 1320 1321 switch (le16_to_cpu(hdr->op)) { 1322 case VIRTIO_VSOCK_OP_RESPONSE: 1323 sk->sk_state = TCP_ESTABLISHED; 1324 sk->sk_socket->state = SS_CONNECTED; 1325 vsock_insert_connected(vsk); 1326 sk->sk_state_change(sk); 1327 break; 1328 case VIRTIO_VSOCK_OP_INVALID: 1329 break; 1330 case VIRTIO_VSOCK_OP_RST: 1331 skerr = ECONNRESET; 1332 err = 0; 1333 goto destroy; 1334 default: 1335 skerr = EPROTO; 1336 err = -EINVAL; 1337 goto destroy; 1338 } 1339 return 0; 1340 1341 destroy: 1342 virtio_transport_reset(vsk, skb); 1343 sk->sk_state = TCP_CLOSE; 1344 sk->sk_err = skerr; 1345 sk_error_report(sk); 1346 return err; 1347 } 1348 1349 static void 1350 virtio_transport_recv_enqueue(struct vsock_sock *vsk, 1351 struct sk_buff *skb) 1352 { 1353 struct virtio_vsock_sock *vvs = vsk->trans; 1354 bool can_enqueue, free_pkt = false; 1355 struct virtio_vsock_hdr *hdr; 1356 u32 len; 1357 1358 hdr = virtio_vsock_hdr(skb); 1359 len = le32_to_cpu(hdr->len); 1360 1361 spin_lock_bh(&vvs->rx_lock); 1362 1363 can_enqueue = virtio_transport_inc_rx_pkt(vvs, len); 1364 if (!can_enqueue) { 1365 free_pkt = true; 1366 goto out; 1367 } 1368 1369 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) 1370 vvs->msg_count++; 1371 1372 /* Try to copy small packets into the buffer of last packet queued, 1373 * to avoid wasting memory queueing the entire buffer with a small 1374 * payload. Skip non-linear (e.g. zerocopy) skbs; these carry payload 1375 * in skb_shinfo. 1376 */ 1377 if (len <= GOOD_COPY_LEN && !skb_queue_empty(&vvs->rx_queue) && 1378 !skb_is_nonlinear(skb)) { 1379 struct virtio_vsock_hdr *last_hdr; 1380 struct sk_buff *last_skb; 1381 1382 last_skb = skb_peek_tail(&vvs->rx_queue); 1383 last_hdr = virtio_vsock_hdr(last_skb); 1384 1385 /* If there is space in the last packet queued, we copy the 1386 * new packet in its buffer. We avoid this if the last packet 1387 * queued has VIRTIO_VSOCK_SEQ_EOM set, because this is 1388 * delimiter of SEQPACKET message, so 'pkt' is the first packet 1389 * of a new message. 1390 */ 1391 if (skb->len < skb_tailroom(last_skb) && 1392 !(le32_to_cpu(last_hdr->flags) & VIRTIO_VSOCK_SEQ_EOM)) { 1393 memcpy(skb_put(last_skb, skb->len), skb->data, skb->len); 1394 free_pkt = true; 1395 last_hdr->flags |= hdr->flags; 1396 le32_add_cpu(&last_hdr->len, len); 1397 goto out; 1398 } 1399 } 1400 1401 __skb_queue_tail(&vvs->rx_queue, skb); 1402 1403 out: 1404 spin_unlock_bh(&vvs->rx_lock); 1405 if (free_pkt) 1406 kfree_skb(skb); 1407 } 1408 1409 static int 1410 virtio_transport_recv_connected(struct sock *sk, 1411 struct sk_buff *skb) 1412 { 1413 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1414 struct vsock_sock *vsk = vsock_sk(sk); 1415 int err = 0; 1416 1417 switch (le16_to_cpu(hdr->op)) { 1418 case VIRTIO_VSOCK_OP_RW: 1419 virtio_transport_recv_enqueue(vsk, skb); 1420 vsock_data_ready(sk); 1421 return err; 1422 case VIRTIO_VSOCK_OP_CREDIT_REQUEST: 1423 virtio_transport_send_credit_update(vsk); 1424 break; 1425 case VIRTIO_VSOCK_OP_CREDIT_UPDATE: 1426 sk->sk_write_space(sk); 1427 break; 1428 case VIRTIO_VSOCK_OP_SHUTDOWN: 1429 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_RCV) 1430 vsk->peer_shutdown |= RCV_SHUTDOWN; 1431 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_SEND) 1432 vsk->peer_shutdown |= SEND_SHUTDOWN; 1433 if (vsk->peer_shutdown == SHUTDOWN_MASK) { 1434 if (vsock_stream_has_data(vsk) <= 0 && !sock_flag(sk, SOCK_DONE)) { 1435 (void)virtio_transport_reset(vsk, NULL); 1436 virtio_transport_do_close(vsk, true); 1437 } 1438 /* Remove this socket anyway because the remote peer sent 1439 * the shutdown. This way a new connection will succeed 1440 * if the remote peer uses the same source port, 1441 * even if the old socket is still unreleased, but now disconnected. 1442 */ 1443 vsock_remove_sock(vsk); 1444 } 1445 if (le32_to_cpu(virtio_vsock_hdr(skb)->flags)) 1446 sk->sk_state_change(sk); 1447 break; 1448 case VIRTIO_VSOCK_OP_RST: 1449 virtio_transport_do_close(vsk, true); 1450 break; 1451 default: 1452 err = -EINVAL; 1453 break; 1454 } 1455 1456 kfree_skb(skb); 1457 return err; 1458 } 1459 1460 static void 1461 virtio_transport_recv_disconnecting(struct sock *sk, 1462 struct sk_buff *skb) 1463 { 1464 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1465 struct vsock_sock *vsk = vsock_sk(sk); 1466 1467 if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST) 1468 virtio_transport_do_close(vsk, true); 1469 } 1470 1471 static int 1472 virtio_transport_send_response(struct vsock_sock *vsk, 1473 struct sk_buff *skb) 1474 { 1475 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1476 struct virtio_vsock_pkt_info info = { 1477 .op = VIRTIO_VSOCK_OP_RESPONSE, 1478 .remote_cid = le64_to_cpu(hdr->src_cid), 1479 .remote_port = le32_to_cpu(hdr->src_port), 1480 .reply = true, 1481 .vsk = vsk, 1482 }; 1483 1484 return virtio_transport_send_pkt_info(vsk, &info); 1485 } 1486 1487 static bool virtio_transport_space_update(struct sock *sk, 1488 struct sk_buff *skb) 1489 { 1490 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1491 struct vsock_sock *vsk = vsock_sk(sk); 1492 struct virtio_vsock_sock *vvs = vsk->trans; 1493 bool space_available; 1494 1495 /* Listener sockets are not associated with any transport, so we are 1496 * not able to take the state to see if there is space available in the 1497 * remote peer, but since they are only used to receive requests, we 1498 * can assume that there is always space available in the other peer. 1499 */ 1500 if (!vvs) 1501 return true; 1502 1503 /* buf_alloc and fwd_cnt is always included in the hdr */ 1504 spin_lock_bh(&vvs->tx_lock); 1505 vvs->peer_buf_alloc = le32_to_cpu(hdr->buf_alloc); 1506 vvs->peer_fwd_cnt = le32_to_cpu(hdr->fwd_cnt); 1507 space_available = virtio_transport_has_space(vvs); 1508 spin_unlock_bh(&vvs->tx_lock); 1509 return space_available; 1510 } 1511 1512 /* Handle server socket */ 1513 static int 1514 virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb, 1515 struct virtio_transport *t) 1516 { 1517 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1518 struct vsock_sock *vsk = vsock_sk(sk); 1519 struct vsock_sock *vchild; 1520 struct sock *child; 1521 int ret; 1522 1523 if (le16_to_cpu(hdr->op) != VIRTIO_VSOCK_OP_REQUEST) { 1524 virtio_transport_reset_no_sock(t, skb); 1525 return -EINVAL; 1526 } 1527 1528 if (sk_acceptq_is_full(sk)) { 1529 virtio_transport_reset_no_sock(t, skb); 1530 return -ENOMEM; 1531 } 1532 1533 /* __vsock_release() might have already flushed accept_queue. 1534 * Subsequent enqueues would lead to a memory leak. 1535 */ 1536 if (sk->sk_shutdown == SHUTDOWN_MASK) { 1537 virtio_transport_reset_no_sock(t, skb); 1538 return -ESHUTDOWN; 1539 } 1540 1541 child = vsock_create_connected(sk); 1542 if (!child) { 1543 virtio_transport_reset_no_sock(t, skb); 1544 return -ENOMEM; 1545 } 1546 1547 sk_acceptq_added(sk); 1548 1549 lock_sock_nested(child, SINGLE_DEPTH_NESTING); 1550 1551 child->sk_state = TCP_ESTABLISHED; 1552 1553 vchild = vsock_sk(child); 1554 vsock_addr_init(&vchild->local_addr, le64_to_cpu(hdr->dst_cid), 1555 le32_to_cpu(hdr->dst_port)); 1556 vsock_addr_init(&vchild->remote_addr, le64_to_cpu(hdr->src_cid), 1557 le32_to_cpu(hdr->src_port)); 1558 1559 ret = vsock_assign_transport(vchild, vsk); 1560 /* Transport assigned (looking at remote_addr) must be the same 1561 * where we received the request. 1562 */ 1563 if (ret || vchild->transport != &t->transport) { 1564 release_sock(child); 1565 virtio_transport_reset_no_sock(t, skb); 1566 sock_put(child); 1567 return ret; 1568 } 1569 1570 if (virtio_transport_space_update(child, skb)) 1571 child->sk_write_space(child); 1572 1573 vsock_insert_connected(vchild); 1574 vsock_enqueue_accept(sk, child); 1575 virtio_transport_send_response(vchild, skb); 1576 1577 release_sock(child); 1578 1579 sk->sk_data_ready(sk); 1580 return 0; 1581 } 1582 1583 static bool virtio_transport_valid_type(u16 type) 1584 { 1585 return (type == VIRTIO_VSOCK_TYPE_STREAM) || 1586 (type == VIRTIO_VSOCK_TYPE_SEQPACKET); 1587 } 1588 1589 /* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex 1590 * lock. 1591 */ 1592 void virtio_transport_recv_pkt(struct virtio_transport *t, 1593 struct sk_buff *skb) 1594 { 1595 struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); 1596 struct sockaddr_vm src, dst; 1597 struct vsock_sock *vsk; 1598 struct sock *sk; 1599 bool space_available; 1600 1601 vsock_addr_init(&src, le64_to_cpu(hdr->src_cid), 1602 le32_to_cpu(hdr->src_port)); 1603 vsock_addr_init(&dst, le64_to_cpu(hdr->dst_cid), 1604 le32_to_cpu(hdr->dst_port)); 1605 1606 trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port, 1607 dst.svm_cid, dst.svm_port, 1608 le32_to_cpu(hdr->len), 1609 le16_to_cpu(hdr->type), 1610 le16_to_cpu(hdr->op), 1611 le32_to_cpu(hdr->flags), 1612 le32_to_cpu(hdr->buf_alloc), 1613 le32_to_cpu(hdr->fwd_cnt)); 1614 1615 if (!virtio_transport_valid_type(le16_to_cpu(hdr->type))) { 1616 (void)virtio_transport_reset_no_sock(t, skb); 1617 goto free_pkt; 1618 } 1619 1620 /* The socket must be in connected or bound table 1621 * otherwise send reset back 1622 */ 1623 sk = vsock_find_connected_socket(&src, &dst); 1624 if (!sk) { 1625 sk = vsock_find_bound_socket(&dst); 1626 if (!sk) { 1627 (void)virtio_transport_reset_no_sock(t, skb); 1628 goto free_pkt; 1629 } 1630 } 1631 1632 if (virtio_transport_get_type(sk) != le16_to_cpu(hdr->type)) { 1633 (void)virtio_transport_reset_no_sock(t, skb); 1634 sock_put(sk); 1635 goto free_pkt; 1636 } 1637 1638 if (!skb_set_owner_sk_safe(skb, sk)) { 1639 WARN_ONCE(1, "receiving vsock socket has sk_refcnt == 0\n"); 1640 goto free_pkt; 1641 } 1642 1643 vsk = vsock_sk(sk); 1644 1645 lock_sock(sk); 1646 1647 /* Check if sk has been closed or assigned to another transport before 1648 * lock_sock (note: listener sockets are not assigned to any transport) 1649 */ 1650 if (sock_flag(sk, SOCK_DONE) || 1651 (sk->sk_state != TCP_LISTEN && vsk->transport != &t->transport)) { 1652 (void)virtio_transport_reset_no_sock(t, skb); 1653 release_sock(sk); 1654 sock_put(sk); 1655 goto free_pkt; 1656 } 1657 1658 space_available = virtio_transport_space_update(sk, skb); 1659 1660 /* Update CID in case it has changed after a transport reset event */ 1661 if (vsk->local_addr.svm_cid != VMADDR_CID_ANY) 1662 vsk->local_addr.svm_cid = dst.svm_cid; 1663 1664 if (space_available) 1665 sk->sk_write_space(sk); 1666 1667 switch (sk->sk_state) { 1668 case TCP_LISTEN: 1669 virtio_transport_recv_listen(sk, skb, t); 1670 kfree_skb(skb); 1671 break; 1672 case TCP_SYN_SENT: 1673 virtio_transport_recv_connecting(sk, skb); 1674 kfree_skb(skb); 1675 break; 1676 case TCP_ESTABLISHED: 1677 virtio_transport_recv_connected(sk, skb); 1678 break; 1679 case TCP_CLOSING: 1680 virtio_transport_recv_disconnecting(sk, skb); 1681 kfree_skb(skb); 1682 break; 1683 default: 1684 (void)virtio_transport_reset_no_sock(t, skb); 1685 kfree_skb(skb); 1686 break; 1687 } 1688 1689 release_sock(sk); 1690 1691 /* Release refcnt obtained when we fetched this socket out of the 1692 * bound or connected list. 1693 */ 1694 sock_put(sk); 1695 return; 1696 1697 free_pkt: 1698 kfree_skb(skb); 1699 } 1700 EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt); 1701 1702 /* Remove skbs found in a queue that have a vsk that matches. 1703 * 1704 * Each skb is freed. 1705 * 1706 * Returns the count of skbs that were reply packets. 1707 */ 1708 int virtio_transport_purge_skbs(void *vsk, struct sk_buff_head *queue) 1709 { 1710 struct sk_buff_head freeme; 1711 struct sk_buff *skb, *tmp; 1712 int cnt = 0; 1713 1714 skb_queue_head_init(&freeme); 1715 1716 spin_lock_bh(&queue->lock); 1717 skb_queue_walk_safe(queue, skb, tmp) { 1718 if (vsock_sk(skb->sk) != vsk) 1719 continue; 1720 1721 __skb_unlink(skb, queue); 1722 __skb_queue_tail(&freeme, skb); 1723 1724 if (virtio_vsock_skb_reply(skb)) 1725 cnt++; 1726 } 1727 spin_unlock_bh(&queue->lock); 1728 1729 __skb_queue_purge(&freeme); 1730 1731 return cnt; 1732 } 1733 EXPORT_SYMBOL_GPL(virtio_transport_purge_skbs); 1734 1735 int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t recv_actor) 1736 { 1737 struct virtio_vsock_sock *vvs = vsk->trans; 1738 struct sock *sk = sk_vsock(vsk); 1739 struct virtio_vsock_hdr *hdr; 1740 struct sk_buff *skb; 1741 u32 pkt_len; 1742 int off = 0; 1743 int err; 1744 1745 spin_lock_bh(&vvs->rx_lock); 1746 /* Use __skb_recv_datagram() for race-free handling of the receive. It 1747 * works for types other than dgrams. 1748 */ 1749 skb = __skb_recv_datagram(sk, &vvs->rx_queue, MSG_DONTWAIT, &off, &err); 1750 if (!skb) { 1751 spin_unlock_bh(&vvs->rx_lock); 1752 return err; 1753 } 1754 1755 hdr = virtio_vsock_hdr(skb); 1756 if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) 1757 vvs->msg_count--; 1758 1759 pkt_len = le32_to_cpu(hdr->len); 1760 virtio_transport_dec_rx_pkt(vvs, pkt_len, pkt_len); 1761 spin_unlock_bh(&vvs->rx_lock); 1762 1763 virtio_transport_send_credit_update(vsk); 1764 1765 return recv_actor(sk, skb); 1766 } 1767 EXPORT_SYMBOL_GPL(virtio_transport_read_skb); 1768 1769 int virtio_transport_notify_set_rcvlowat(struct vsock_sock *vsk, int val) 1770 { 1771 struct virtio_vsock_sock *vvs = vsk->trans; 1772 bool send_update; 1773 1774 spin_lock_bh(&vvs->rx_lock); 1775 1776 /* If number of available bytes is less than new SO_RCVLOWAT value, 1777 * kick sender to send more data, because sender may sleep in its 1778 * 'send()' syscall waiting for enough space at our side. Also 1779 * don't send credit update when peer already knows actual value - 1780 * such transmission will be useless. 1781 */ 1782 send_update = (vvs->rx_bytes < val) && 1783 (vvs->fwd_cnt != vvs->last_fwd_cnt); 1784 1785 spin_unlock_bh(&vvs->rx_lock); 1786 1787 if (send_update) { 1788 int err; 1789 1790 err = virtio_transport_send_credit_update(vsk); 1791 if (err < 0) 1792 return err; 1793 } 1794 1795 return 0; 1796 } 1797 EXPORT_SYMBOL_GPL(virtio_transport_notify_set_rcvlowat); 1798 1799 MODULE_LICENSE("GPL v2"); 1800 MODULE_AUTHOR("Asias He"); 1801 MODULE_DESCRIPTION("common code for virtio vsock"); 1802