net/vmw_vsock/virtio_transport_common.c

   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 const struct virtio_transport *
  30 virtio_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
  40 static struct virtio_vsock_pkt *
  41 virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,
  42                            size_t len,
  43                            u32 src_cid,
  44                            u32 src_port,
  45                            u32 dst_cid,
  46                            u32 dst_port)
  47 {
  48         struct virtio_vsock_pkt *pkt;
  49         int err;
  50
  51         pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
  52         if (!pkt)
  53                 return NULL;
  54
  55         pkt->hdr.type           = cpu_to_le16(info->type);
  56         pkt->hdr.op             = cpu_to_le16(info->op);
  57         pkt->hdr.src_cid        = cpu_to_le64(src_cid);
  58         pkt->hdr.dst_cid        = cpu_to_le64(dst_cid);
  59         pkt->hdr.src_port       = cpu_to_le32(src_port);
  60         pkt->hdr.dst_port       = cpu_to_le32(dst_port);
  61         pkt->hdr.flags          = cpu_to_le32(info->flags);
  62         pkt->len                = len;
  63         pkt->hdr.len            = cpu_to_le32(len);
  64         pkt->reply              = info->reply;
  65         pkt->vsk                = info->vsk;
  66
  67         if (info->msg && len > 0) {
  68                 pkt->buf = kmalloc(len, GFP_KERNEL);
  69                 if (!pkt->buf)
  70                         goto out_pkt;
  71
  72                 pkt->buf_len = len;
  73
  74                 err = memcpy_from_msg(pkt->buf, info->msg, len);
  75                 if (err)
  76                         goto out;
  77
  78                 if (msg_data_left(info->msg) == 0 &&
  79                     info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) {
  80                         pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
  81
  82                         if (info->msg->msg_flags & MSG_EOR)
  83                                 pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
  84                 }
  85         }
  86
  87         trace_virtio_transport_alloc_pkt(src_cid, src_port,
  88                                          dst_cid, dst_port,
  89                                          len,
  90                                          info->type,
  91                                          info->op,
  92                                          info->flags);
  93
  94         return pkt;
  95
  96 out:
  97         kfree(pkt->buf);
  98 out_pkt:
  99         kfree(pkt);
 100         return NULL;
 101 }
 102
 103 /* Packet capture */
 104 static struct sk_buff *virtio_transport_build_skb(void *opaque)
 105 {
 106         struct virtio_vsock_pkt *pkt = opaque;
 107         struct af_vsockmon_hdr *hdr;
 108         struct sk_buff *skb;
 109         size_t payload_len;
 110         void *payload_buf;
 111
 112         /* A packet could be split to fit the RX buffer, so we can retrieve
 113          * the payload length from the header and the buffer pointer taking
 114          * care of the offset in the original packet.
 115          */
 116         payload_len = le32_to_cpu(pkt->hdr.len);
 117         payload_buf = pkt->buf + pkt->off;
 118
 119         skb = alloc_skb(sizeof(*hdr) + sizeof(pkt->hdr) + payload_len,
 120                         GFP_ATOMIC);
 121         if (!skb)
 122                 return NULL;
 123
 124         hdr = skb_put(skb, sizeof(*hdr));
 125
 126         /* pkt->hdr is little-endian so no need to byteswap here */
 127         hdr->src_cid = pkt->hdr.src_cid;
 128         hdr->src_port = pkt->hdr.src_port;
 129         hdr->dst_cid = pkt->hdr.dst_cid;
 130         hdr->dst_port = pkt->hdr.dst_port;
 131
 132         hdr->transport = cpu_to_le16(AF_VSOCK_TRANSPORT_VIRTIO);
 133         hdr->len = cpu_to_le16(sizeof(pkt->hdr));
 134         memset(hdr->reserved, 0, sizeof(hdr->reserved));
 135
 136         switch (le16_to_cpu(pkt->hdr.op)) {
 137         case VIRTIO_VSOCK_OP_REQUEST:
 138         case VIRTIO_VSOCK_OP_RESPONSE:
 139                 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONNECT);
 140                 break;
 141         case VIRTIO_VSOCK_OP_RST:
 142         case VIRTIO_VSOCK_OP_SHUTDOWN:
 143                 hdr->op = cpu_to_le16(AF_VSOCK_OP_DISCONNECT);
 144                 break;
 145         case VIRTIO_VSOCK_OP_RW:
 146                 hdr->op = cpu_to_le16(AF_VSOCK_OP_PAYLOAD);
 147                 break;
 148         case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
 149         case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
 150                 hdr->op = cpu_to_le16(AF_VSOCK_OP_CONTROL);
 151                 break;
 152         default:
 153                 hdr->op = cpu_to_le16(AF_VSOCK_OP_UNKNOWN);
 154                 break;
 155         }
 156
 157         skb_put_data(skb, &pkt->hdr, sizeof(pkt->hdr));
 158
 159         if (payload_len) {
 160                 skb_put_data(skb, payload_buf, payload_len);
 161         }
 162
 163         return skb;
 164 }
 165
 166 void virtio_transport_deliver_tap_pkt(struct virtio_vsock_pkt *pkt)
 167 {
 168         if (pkt->tap_delivered)
 169                 return;
 170
 171         vsock_deliver_tap(virtio_transport_build_skb, pkt);
 172         pkt->tap_delivered = true;
 173 }
 174 EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);
 175
 176 static u16 virtio_transport_get_type(struct sock *sk)
 177 {
 178         if (sk->sk_type == SOCK_STREAM)
 179                 return VIRTIO_VSOCK_TYPE_STREAM;
 180         else
 181                 return VIRTIO_VSOCK_TYPE_SEQPACKET;
 182 }
 183
 184 /* This function can only be used on connecting/connected sockets,
 185  * since a socket assigned to a transport is required.
 186  *
 187  * Do not use on listener sockets!
 188  */
 189 static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
 190                                           struct virtio_vsock_pkt_info *info)
 191 {
 192         u32 src_cid, src_port, dst_cid, dst_port;
 193         const struct virtio_transport *t_ops;
 194         struct virtio_vsock_sock *vvs;
 195         struct virtio_vsock_pkt *pkt;
 196         u32 pkt_len = info->pkt_len;
 197
 198         info->type = virtio_transport_get_type(sk_vsock(vsk));
 199
 200         t_ops = virtio_transport_get_ops(vsk);
 201         if (unlikely(!t_ops))
 202                 return -EFAULT;
 203
 204         src_cid = t_ops->transport.get_local_cid();
 205         src_port = vsk->local_addr.svm_port;
 206         if (!info->remote_cid) {
 207                 dst_cid = vsk->remote_addr.svm_cid;
 208                 dst_port = vsk->remote_addr.svm_port;
 209         } else {
 210                 dst_cid = info->remote_cid;
 211                 dst_port = info->remote_port;
 212         }
 213
 214         vvs = vsk->trans;
 215
 216         /* we can send less than pkt_len bytes */
 217         if (pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE)
 218                 pkt_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
 219
 220         /* virtio_transport_get_credit might return less than pkt_len credit */
 221         pkt_len = virtio_transport_get_credit(vvs, pkt_len);
 222
 223         /* Do not send zero length OP_RW pkt */
 224         if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
 225                 return pkt_len;
 226
 227         pkt = virtio_transport_alloc_pkt(info, pkt_len,
 228                                          src_cid, src_port,
 229                                          dst_cid, dst_port);
 230         if (!pkt) {
 231                 virtio_transport_put_credit(vvs, pkt_len);
 232                 return -ENOMEM;
 233         }
 234
 235         virtio_transport_inc_tx_pkt(vvs, pkt);
 236
 237         return t_ops->send_pkt(pkt);
 238 }
 239
 240 static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
 241                                         struct virtio_vsock_pkt *pkt)
 242 {
 243         if (vvs->rx_bytes + pkt->len > vvs->buf_alloc)
 244                 return false;
 245
 246         vvs->rx_bytes += pkt->len;
 247         return true;
 248 }
 249
 250 static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
 251                                         struct virtio_vsock_pkt *pkt)
 252 {
 253         vvs->rx_bytes -= pkt->len;
 254         vvs->fwd_cnt += pkt->len;
 255 }
 256
 257 void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
 258 {
 259         spin_lock_bh(&vvs->rx_lock);
 260         vvs->last_fwd_cnt = vvs->fwd_cnt;
 261         pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
 262         pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
 263         spin_unlock_bh(&vvs->rx_lock);
 264 }
 265 EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
 266
 267 u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit)
 268 {
 269         u32 ret;
 270
 271         spin_lock_bh(&vvs->tx_lock);
 272         ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
 273         if (ret > credit)
 274                 ret = credit;
 275         vvs->tx_cnt += ret;
 276         spin_unlock_bh(&vvs->tx_lock);
 277
 278         return ret;
 279 }
 280 EXPORT_SYMBOL_GPL(virtio_transport_get_credit);
 281
 282 void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit)
 283 {
 284         spin_lock_bh(&vvs->tx_lock);
 285         vvs->tx_cnt -= credit;
 286         spin_unlock_bh(&vvs->tx_lock);
 287 }
 288 EXPORT_SYMBOL_GPL(virtio_transport_put_credit);
 289
 290 static int virtio_transport_send_credit_update(struct vsock_sock *vsk)
 291 {
 292         struct virtio_vsock_pkt_info info = {
 293                 .op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
 294                 .vsk = vsk,
 295         };
 296
 297         return virtio_transport_send_pkt_info(vsk, &info);
 298 }
 299
 300 static ssize_t
 301 virtio_transport_stream_do_peek(struct vsock_sock *vsk,
 302                                 struct msghdr *msg,
 303                                 size_t len)
 304 {
 305         struct virtio_vsock_sock *vvs = vsk->trans;
 306         struct virtio_vsock_pkt *pkt;
 307         size_t bytes, total = 0, off;
 308         int err = -EFAULT;
 309
 310         spin_lock_bh(&vvs->rx_lock);
 311
 312         list_for_each_entry(pkt, &vvs->rx_queue, list) {
 313                 off = pkt->off;
 314
 315                 if (total == len)
 316                         break;
 317
 318                 while (total < len && off < pkt->len) {
 319                         bytes = len - total;
 320                         if (bytes > pkt->len - off)
 321                                 bytes = pkt->len - off;
 322
 323                         /* sk_lock is held by caller so no one else can dequeue.
 324                          * Unlock rx_lock since memcpy_to_msg() may sleep.
 325                          */
 326                         spin_unlock_bh(&vvs->rx_lock);
 327
 328                         err = memcpy_to_msg(msg, pkt->buf + off, bytes);
 329                         if (err)
 330                                 goto out;
 331
 332                         spin_lock_bh(&vvs->rx_lock);
 333
 334                         total += bytes;
 335                         off += bytes;
 336                 }
 337         }
 338
 339         spin_unlock_bh(&vvs->rx_lock);
 340
 341         return total;
 342
 343 out:
 344         if (total)
 345                 err = total;
 346         return err;
 347 }
 348
 349 static ssize_t
 350 virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
 351                                    struct msghdr *msg,
 352                                    size_t len)
 353 {
 354         struct virtio_vsock_sock *vvs = vsk->trans;
 355         struct virtio_vsock_pkt *pkt;
 356         size_t bytes, total = 0;
 357         u32 free_space;
 358         int err = -EFAULT;
 359
 360         spin_lock_bh(&vvs->rx_lock);
 361         while (total < len && !list_empty(&vvs->rx_queue)) {
 362                 pkt = list_first_entry(&vvs->rx_queue,
 363                                        struct virtio_vsock_pkt, list);
 364
 365                 bytes = len - total;
 366                 if (bytes > pkt->len - pkt->off)
 367                         bytes = pkt->len - pkt->off;
 368
 369                 /* sk_lock is held by caller so no one else can dequeue.
 370                  * Unlock rx_lock since memcpy_to_msg() may sleep.
 371                  */
 372                 spin_unlock_bh(&vvs->rx_lock);
 373
 374                 err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes);
 375                 if (err)
 376                         goto out;
 377
 378                 spin_lock_bh(&vvs->rx_lock);
 379
 380                 total += bytes;
 381                 pkt->off += bytes;
 382                 if (pkt->off == pkt->len) {
 383                         virtio_transport_dec_rx_pkt(vvs, pkt);
 384                         list_del(&pkt->list);
 385                         virtio_transport_free_pkt(pkt);
 386                 }
 387         }
 388
 389         free_space = vvs->buf_alloc - (vvs->fwd_cnt - vvs->last_fwd_cnt);
 390
 391         spin_unlock_bh(&vvs->rx_lock);
 392
 393         /* To reduce the number of credit update messages,
 394          * don't update credits as long as lots of space is available.
 395          * Note: the limit chosen here is arbitrary. Setting the limit
 396          * too high causes extra messages. Too low causes transmitter
 397          * stalls. As stalls are in theory more expensive than extra
 398          * messages, we set the limit to a high value. TODO: experiment
 399          * with different values.
 400          */
 401         if (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE)
 402                 virtio_transport_send_credit_update(vsk);
 403
 404         return total;
 405
 406 out:
 407         if (total)
 408                 err = total;
 409         return err;
 410 }
 411
 412 static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
 413                                                  struct msghdr *msg,
 414                                                  int flags)
 415 {
 416         struct virtio_vsock_sock *vvs = vsk->trans;
 417         struct virtio_vsock_pkt *pkt;
 418         int dequeued_len = 0;
 419         size_t user_buf_len = msg_data_left(msg);
 420         bool msg_ready = false;
 421
 422         spin_lock_bh(&vvs->rx_lock);
 423
 424         if (vvs->msg_count == 0) {
 425                 spin_unlock_bh(&vvs->rx_lock);
 426                 return 0;
 427         }
 428
 429         while (!msg_ready) {
 430                 pkt = list_first_entry(&vvs->rx_queue, struct virtio_vsock_pkt, list);
 431
 432                 if (dequeued_len >= 0) {
 433                         size_t pkt_len;
 434                         size_t bytes_to_copy;
 435
 436                         pkt_len = (size_t)le32_to_cpu(pkt->hdr.len);
 437                         bytes_to_copy = min(user_buf_len, pkt_len);
 438
 439                         if (bytes_to_copy) {
 440                                 int err;
 441
 442                                 /* sk_lock is held by caller so no one else can dequeue.
 443                                  * Unlock rx_lock since memcpy_to_msg() may sleep.
 444                                  */
 445                                 spin_unlock_bh(&vvs->rx_lock);
 446
 447                                 err = memcpy_to_msg(msg, pkt->buf, bytes_to_copy);
 448                                 if (err) {
 449                                         /* Copy of message failed. Rest of
 450                                          * fragments will be freed without copy.
 451                                          */
 452                                         dequeued_len = err;
 453                                 } else {
 454                                         user_buf_len -= bytes_to_copy;
 455                                 }
 456
 457                                 spin_lock_bh(&vvs->rx_lock);
 458                         }
 459
 460                         if (dequeued_len >= 0)
 461                                 dequeued_len += pkt_len;
 462                 }
 463
 464                 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM) {
 465                         msg_ready = true;
 466                         vvs->msg_count--;
 467
 468                         if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR)
 469                                 msg->msg_flags |= MSG_EOR;
 470                 }
 471
 472                 virtio_transport_dec_rx_pkt(vvs, pkt);
 473                 list_del(&pkt->list);
 474                 virtio_transport_free_pkt(pkt);
 475         }
 476
 477         spin_unlock_bh(&vvs->rx_lock);
 478
 479         virtio_transport_send_credit_update(vsk);
 480
 481         return dequeued_len;
 482 }
 483
 484 ssize_t
 485 virtio_transport_stream_dequeue(struct vsock_sock *vsk,
 486                                 struct msghdr *msg,
 487                                 size_t len, int flags)
 488 {
 489         if (flags & MSG_PEEK)
 490                 return virtio_transport_stream_do_peek(vsk, msg, len);
 491         else
 492                 return virtio_transport_stream_do_dequeue(vsk, msg, len);
 493 }
 494 EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
 495
 496 ssize_t
 497 virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk,
 498                                    struct msghdr *msg,
 499                                    int flags)
 500 {
 501         if (flags & MSG_PEEK)
 502                 return -EOPNOTSUPP;
 503
 504         return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
 505 }
 506 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue);
 507
 508 int
 509 virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
 510                                    struct msghdr *msg,
 511                                    size_t len)
 512 {
 513         struct virtio_vsock_sock *vvs = vsk->trans;
 514
 515         spin_lock_bh(&vvs->tx_lock);
 516
 517         if (len > vvs->peer_buf_alloc) {
 518                 spin_unlock_bh(&vvs->tx_lock);
 519                 return -EMSGSIZE;
 520         }
 521
 522         spin_unlock_bh(&vvs->tx_lock);
 523
 524         return virtio_transport_stream_enqueue(vsk, msg, len);
 525 }
 526 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_enqueue);
 527
 528 int
 529 virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
 530                                struct msghdr *msg,
 531                                size_t len, int flags)
 532 {
 533         return -EOPNOTSUPP;
 534 }
 535 EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
 536
 537 s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
 538 {
 539         struct virtio_vsock_sock *vvs = vsk->trans;
 540         s64 bytes;
 541
 542         spin_lock_bh(&vvs->rx_lock);
 543         bytes = vvs->rx_bytes;
 544         spin_unlock_bh(&vvs->rx_lock);
 545
 546         return bytes;
 547 }
 548 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data);
 549
 550 u32 virtio_transport_seqpacket_has_data(struct vsock_sock *vsk)
 551 {
 552         struct virtio_vsock_sock *vvs = vsk->trans;
 553         u32 msg_count;
 554
 555         spin_lock_bh(&vvs->rx_lock);
 556         msg_count = vvs->msg_count;
 557         spin_unlock_bh(&vvs->rx_lock);
 558
 559         return msg_count;
 560 }
 561 EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_has_data);
 562
 563 static s64 virtio_transport_has_space(struct vsock_sock *vsk)
 564 {
 565         struct virtio_vsock_sock *vvs = vsk->trans;
 566         s64 bytes;
 567
 568         bytes = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
 569         if (bytes < 0)
 570                 bytes = 0;
 571
 572         return bytes;
 573 }
 574
 575 s64 virtio_transport_stream_has_space(struct vsock_sock *vsk)
 576 {
 577         struct virtio_vsock_sock *vvs = vsk->trans;
 578         s64 bytes;
 579
 580         spin_lock_bh(&vvs->tx_lock);
 581         bytes = virtio_transport_has_space(vsk);
 582         spin_unlock_bh(&vvs->tx_lock);
 583
 584         return bytes;
 585 }
 586 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space);
 587
 588 int virtio_transport_do_socket_init(struct vsock_sock *vsk,
 589                                     struct vsock_sock *psk)
 590 {
 591         struct virtio_vsock_sock *vvs;
 592
 593         vvs = kzalloc(sizeof(*vvs), GFP_KERNEL);
 594         if (!vvs)
 595                 return -ENOMEM;
 596
 597         vsk->trans = vvs;
 598         vvs->vsk = vsk;
 599         if (psk && psk->trans) {
 600                 struct virtio_vsock_sock *ptrans = psk->trans;
 601
 602                 vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
 603         }
 604
 605         if (vsk->buffer_size > VIRTIO_VSOCK_MAX_BUF_SIZE)
 606                 vsk->buffer_size = VIRTIO_VSOCK_MAX_BUF_SIZE;
 607
 608         vvs->buf_alloc = vsk->buffer_size;
 609
 610         spin_lock_init(&vvs->rx_lock);
 611         spin_lock_init(&vvs->tx_lock);
 612         INIT_LIST_HEAD(&vvs->rx_queue);
 613
 614         return 0;
 615 }
 616 EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init);
 617
 618 /* sk_lock held by the caller */
 619 void virtio_transport_notify_buffer_size(struct vsock_sock *vsk, u64 *val)
 620 {
 621         struct virtio_vsock_sock *vvs = vsk->trans;
 622
 623         if (*val > VIRTIO_VSOCK_MAX_BUF_SIZE)
 624                 *val = VIRTIO_VSOCK_MAX_BUF_SIZE;
 625
 626         vvs->buf_alloc = *val;
 627
 628         virtio_transport_send_credit_update(vsk);
 629 }
 630 EXPORT_SYMBOL_GPL(virtio_transport_notify_buffer_size);
 631
 632 int
 633 virtio_transport_notify_poll_in(struct vsock_sock *vsk,
 634                                 size_t target,
 635                                 bool *data_ready_now)
 636 {
 637         if (vsock_stream_has_data(vsk))
 638                 *data_ready_now = true;
 639         else
 640                 *data_ready_now = false;
 641
 642         return 0;
 643 }
 644 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in);
 645
 646 int
 647 virtio_transport_notify_poll_out(struct vsock_sock *vsk,
 648                                  size_t target,
 649                                  bool *space_avail_now)
 650 {
 651         s64 free_space;
 652
 653         free_space = vsock_stream_has_space(vsk);
 654         if (free_space > 0)
 655                 *space_avail_now = true;
 656         else if (free_space == 0)
 657                 *space_avail_now = false;
 658
 659         return 0;
 660 }
 661 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out);
 662
 663 int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
 664         size_t target, struct vsock_transport_recv_notify_data *data)
 665 {
 666         return 0;
 667 }
 668 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init);
 669
 670 int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
 671         size_t target, struct vsock_transport_recv_notify_data *data)
 672 {
 673         return 0;
 674 }
 675 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block);
 676
 677 int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
 678         size_t target, struct vsock_transport_recv_notify_data *data)
 679 {
 680         return 0;
 681 }
 682 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue);
 683
 684 int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
 685         size_t target, ssize_t copied, bool data_read,
 686         struct vsock_transport_recv_notify_data *data)
 687 {
 688         return 0;
 689 }
 690 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue);
 691
 692 int virtio_transport_notify_send_init(struct vsock_sock *vsk,
 693         struct vsock_transport_send_notify_data *data)
 694 {
 695         return 0;
 696 }
 697 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init);
 698
 699 int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
 700         struct vsock_transport_send_notify_data *data)
 701 {
 702         return 0;
 703 }
 704 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block);
 705
 706 int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
 707         struct vsock_transport_send_notify_data *data)
 708 {
 709         return 0;
 710 }
 711 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue);
 712
 713 int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
 714         ssize_t written, struct vsock_transport_send_notify_data *data)
 715 {
 716         return 0;
 717 }
 718 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue);
 719
 720 u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk)
 721 {
 722         return vsk->buffer_size;
 723 }
 724 EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat);
 725
 726 bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
 727 {
 728         return true;
 729 }
 730 EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
 731
 732 bool virtio_transport_stream_allow(u32 cid, u32 port)
 733 {
 734         return true;
 735 }
 736 EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
 737
 738 int virtio_transport_dgram_bind(struct vsock_sock *vsk,
 739                                 struct sockaddr_vm *addr)
 740 {
 741         return -EOPNOTSUPP;
 742 }
 743 EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
 744
 745 bool virtio_transport_dgram_allow(u32 cid, u32 port)
 746 {
 747         return false;
 748 }
 749 EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
 750
 751 int virtio_transport_connect(struct vsock_sock *vsk)
 752 {
 753         struct virtio_vsock_pkt_info info = {
 754                 .op = VIRTIO_VSOCK_OP_REQUEST,
 755                 .vsk = vsk,
 756         };
 757
 758         return virtio_transport_send_pkt_info(vsk, &info);
 759 }
 760 EXPORT_SYMBOL_GPL(virtio_transport_connect);
 761
 762 int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
 763 {
 764         struct virtio_vsock_pkt_info info = {
 765                 .op = VIRTIO_VSOCK_OP_SHUTDOWN,
 766                 .flags = (mode & RCV_SHUTDOWN ?
 767                           VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
 768                          (mode & SEND_SHUTDOWN ?
 769                           VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
 770                 .vsk = vsk,
 771         };
 772
 773         return virtio_transport_send_pkt_info(vsk, &info);
 774 }
 775 EXPORT_SYMBOL_GPL(virtio_transport_shutdown);
 776
 777 int
 778 virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
 779                                struct sockaddr_vm *remote_addr,
 780                                struct msghdr *msg,
 781                                size_t dgram_len)
 782 {
 783         return -EOPNOTSUPP;
 784 }
 785 EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
 786
 787 ssize_t
 788 virtio_transport_stream_enqueue(struct vsock_sock *vsk,
 789                                 struct msghdr *msg,
 790                                 size_t len)
 791 {
 792         struct virtio_vsock_pkt_info info = {
 793                 .op = VIRTIO_VSOCK_OP_RW,
 794                 .msg = msg,
 795                 .pkt_len = len,
 796                 .vsk = vsk,
 797         };
 798
 799         return virtio_transport_send_pkt_info(vsk, &info);
 800 }
 801 EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);
 802
 803 void virtio_transport_destruct(struct vsock_sock *vsk)
 804 {
 805         struct virtio_vsock_sock *vvs = vsk->trans;
 806
 807         kfree(vvs);
 808 }
 809 EXPORT_SYMBOL_GPL(virtio_transport_destruct);
 810
 811 static int virtio_transport_reset(struct vsock_sock *vsk,
 812                                   struct virtio_vsock_pkt *pkt)
 813 {
 814         struct virtio_vsock_pkt_info info = {
 815                 .op = VIRTIO_VSOCK_OP_RST,
 816                 .reply = !!pkt,
 817                 .vsk = vsk,
 818         };
 819
 820         /* Send RST only if the original pkt is not a RST pkt */
 821         if (pkt && le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
 822                 return 0;
 823
 824         return virtio_transport_send_pkt_info(vsk, &info);
 825 }
 826
 827 /* Normally packets are associated with a socket.  There may be no socket if an
 828  * attempt was made to connect to a socket that does not exist.
 829  */
 830 static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
 831                                           struct virtio_vsock_pkt *pkt)
 832 {
 833         struct virtio_vsock_pkt *reply;
 834         struct virtio_vsock_pkt_info info = {
 835                 .op = VIRTIO_VSOCK_OP_RST,
 836                 .type = le16_to_cpu(pkt->hdr.type),
 837                 .reply = true,
 838         };
 839
 840         /* Send RST only if the original pkt is not a RST pkt */
 841         if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
 842                 return 0;
 843
 844         reply = virtio_transport_alloc_pkt(&info, 0,
 845                                            le64_to_cpu(pkt->hdr.dst_cid),
 846                                            le32_to_cpu(pkt->hdr.dst_port),
 847                                            le64_to_cpu(pkt->hdr.src_cid),
 848                                            le32_to_cpu(pkt->hdr.src_port));
 849         if (!reply)
 850                 return -ENOMEM;
 851
 852         if (!t) {
 853                 virtio_transport_free_pkt(reply);
 854                 return -ENOTCONN;
 855         }
 856
 857         return t->send_pkt(reply);
 858 }
 859
 860 /* This function should be called with sk_lock held and SOCK_DONE set */
 861 static void virtio_transport_remove_sock(struct vsock_sock *vsk)
 862 {
 863         struct virtio_vsock_sock *vvs = vsk->trans;
 864         struct virtio_vsock_pkt *pkt, *tmp;
 865
 866         /* We don't need to take rx_lock, as the socket is closing and we are
 867          * removing it.
 868          */
 869         list_for_each_entry_safe(pkt, tmp, &vvs->rx_queue, list) {
 870                 list_del(&pkt->list);
 871                 virtio_transport_free_pkt(pkt);
 872         }
 873
 874         vsock_remove_sock(vsk);
 875 }
 876
 877 static void virtio_transport_wait_close(struct sock *sk, long timeout)
 878 {
 879         if (timeout) {
 880                 DEFINE_WAIT_FUNC(wait, woken_wake_function);
 881
 882                 add_wait_queue(sk_sleep(sk), &wait);
 883
 884                 do {
 885                         if (sk_wait_event(sk, &timeout,
 886                                           sock_flag(sk, SOCK_DONE), &wait))
 887                                 break;
 888                 } while (!signal_pending(current) && timeout);
 889
 890                 remove_wait_queue(sk_sleep(sk), &wait);
 891         }
 892 }
 893
 894 static void virtio_transport_do_close(struct vsock_sock *vsk,
 895                                       bool cancel_timeout)
 896 {
 897         struct sock *sk = sk_vsock(vsk);
 898
 899         sock_set_flag(sk, SOCK_DONE);
 900         vsk->peer_shutdown = SHUTDOWN_MASK;
 901         if (vsock_stream_has_data(vsk) <= 0)
 902                 sk->sk_state = TCP_CLOSING;
 903         sk->sk_state_change(sk);
 904
 905         if (vsk->close_work_scheduled &&
 906             (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
 907                 vsk->close_work_scheduled = false;
 908
 909                 virtio_transport_remove_sock(vsk);
 910
 911                 /* Release refcnt obtained when we scheduled the timeout */
 912                 sock_put(sk);
 913         }
 914 }
 915
 916 static void virtio_transport_close_timeout(struct work_struct *work)
 917 {
 918         struct vsock_sock *vsk =
 919                 container_of(work, struct vsock_sock, close_work.work);
 920         struct sock *sk = sk_vsock(vsk);
 921
 922         sock_hold(sk);
 923         lock_sock(sk);
 924
 925         if (!sock_flag(sk, SOCK_DONE)) {
 926                 (void)virtio_transport_reset(vsk, NULL);
 927
 928                 virtio_transport_do_close(vsk, false);
 929         }
 930
 931         vsk->close_work_scheduled = false;
 932
 933         release_sock(sk);
 934         sock_put(sk);
 935 }
 936
 937 /* User context, vsk->sk is locked */
 938 static bool virtio_transport_close(struct vsock_sock *vsk)
 939 {
 940         struct sock *sk = &vsk->sk;
 941
 942         if (!(sk->sk_state == TCP_ESTABLISHED ||
 943               sk->sk_state == TCP_CLOSING))
 944                 return true;
 945
 946         /* Already received SHUTDOWN from peer, reply with RST */
 947         if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) {
 948                 (void)virtio_transport_reset(vsk, NULL);
 949                 return true;
 950         }
 951
 952         if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
 953                 (void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
 954
 955         if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
 956                 virtio_transport_wait_close(sk, sk->sk_lingertime);
 957
 958         if (sock_flag(sk, SOCK_DONE)) {
 959                 return true;
 960         }
 961
 962         sock_hold(sk);
 963         INIT_DELAYED_WORK(&vsk->close_work,
 964                           virtio_transport_close_timeout);
 965         vsk->close_work_scheduled = true;
 966         schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT);
 967         return false;
 968 }
 969
 970 void virtio_transport_release(struct vsock_sock *vsk)
 971 {
 972         struct sock *sk = &vsk->sk;
 973         bool remove_sock = true;
 974
 975         if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)
 976                 remove_sock = virtio_transport_close(vsk);
 977
 978         if (remove_sock) {
 979                 sock_set_flag(sk, SOCK_DONE);
 980                 virtio_transport_remove_sock(vsk);
 981         }
 982 }
 983 EXPORT_SYMBOL_GPL(virtio_transport_release);
 984
 985 static int
 986 virtio_transport_recv_connecting(struct sock *sk,
 987                                  struct virtio_vsock_pkt *pkt)
 988 {
 989         struct vsock_sock *vsk = vsock_sk(sk);
 990         int err;
 991         int skerr;
 992
 993         switch (le16_to_cpu(pkt->hdr.op)) {
 994         case VIRTIO_VSOCK_OP_RESPONSE:
 995                 sk->sk_state = TCP_ESTABLISHED;
 996                 sk->sk_socket->state = SS_CONNECTED;
 997                 vsock_insert_connected(vsk);
 998                 sk->sk_state_change(sk);
 999                 break;
1000         case VIRTIO_VSOCK_OP_INVALID:
1001                 break;
1002         case VIRTIO_VSOCK_OP_RST:
1003                 skerr = ECONNRESET;
1004                 err = 0;
1005                 goto destroy;
1006         default:
1007                 skerr = EPROTO;
1008                 err = -EINVAL;
1009                 goto destroy;
1010         }
1011         return 0;
1012
1013 destroy:
1014         virtio_transport_reset(vsk, pkt);
1015         sk->sk_state = TCP_CLOSE;
1016         sk->sk_err = skerr;
1017         sk_error_report(sk);
1018         return err;
1019 }
1020
1021 static void
1022 virtio_transport_recv_enqueue(struct vsock_sock *vsk,
1023                               struct virtio_vsock_pkt *pkt)
1024 {
1025         struct virtio_vsock_sock *vvs = vsk->trans;
1026         bool can_enqueue, free_pkt = false;
1027
1028         pkt->len = le32_to_cpu(pkt->hdr.len);
1029         pkt->off = 0;
1030
1031         spin_lock_bh(&vvs->rx_lock);
1032
1033         can_enqueue = virtio_transport_inc_rx_pkt(vvs, pkt);
1034         if (!can_enqueue) {
1035                 free_pkt = true;
1036                 goto out;
1037         }
1038
1039         if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM)
1040                 vvs->msg_count++;
1041
1042         /* Try to copy small packets into the buffer of last packet queued,
1043          * to avoid wasting memory queueing the entire buffer with a small
1044          * payload.
1045          */
1046         if (pkt->len <= GOOD_COPY_LEN && !list_empty(&vvs->rx_queue)) {
1047                 struct virtio_vsock_pkt *last_pkt;
1048
1049                 last_pkt = list_last_entry(&vvs->rx_queue,
1050                                            struct virtio_vsock_pkt, list);
1051
1052                 /* If there is space in the last packet queued, we copy the
1053                  * new packet in its buffer. We avoid this if the last packet
1054                  * queued has VIRTIO_VSOCK_SEQ_EOM set, because this is
1055                  * delimiter of SEQPACKET message, so 'pkt' is the first packet
1056                  * of a new message.
1057                  */
1058                 if ((pkt->len <= last_pkt->buf_len - last_pkt->len) &&
1059                     !(le32_to_cpu(last_pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM)) {
1060                         memcpy(last_pkt->buf + last_pkt->len, pkt->buf,
1061                                pkt->len);
1062                         last_pkt->len += pkt->len;
1063                         free_pkt = true;
1064                         last_pkt->hdr.flags |= pkt->hdr.flags;
1065                         goto out;
1066                 }
1067         }
1068
1069         list_add_tail(&pkt->list, &vvs->rx_queue);
1070
1071 out:
1072         spin_unlock_bh(&vvs->rx_lock);
1073         if (free_pkt)
1074                 virtio_transport_free_pkt(pkt);
1075 }
1076
1077 static int
1078 virtio_transport_recv_connected(struct sock *sk,
1079                                 struct virtio_vsock_pkt *pkt)
1080 {
1081         struct vsock_sock *vsk = vsock_sk(sk);
1082         int err = 0;
1083
1084         switch (le16_to_cpu(pkt->hdr.op)) {
1085         case VIRTIO_VSOCK_OP_RW:
1086                 virtio_transport_recv_enqueue(vsk, pkt);
1087                 sk->sk_data_ready(sk);
1088                 return err;
1089         case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
1090                 virtio_transport_send_credit_update(vsk);
1091                 break;
1092         case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
1093                 sk->sk_write_space(sk);
1094                 break;
1095         case VIRTIO_VSOCK_OP_SHUTDOWN:
1096                 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
1097                         vsk->peer_shutdown |= RCV_SHUTDOWN;
1098                 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
1099                         vsk->peer_shutdown |= SEND_SHUTDOWN;
1100                 if (vsk->peer_shutdown == SHUTDOWN_MASK &&
1101                     vsock_stream_has_data(vsk) <= 0 &&
1102                     !sock_flag(sk, SOCK_DONE)) {
1103                         (void)virtio_transport_reset(vsk, NULL);
1104
1105                         virtio_transport_do_close(vsk, true);
1106                 }
1107                 if (le32_to_cpu(pkt->hdr.flags))
1108                         sk->sk_state_change(sk);
1109                 break;
1110         case VIRTIO_VSOCK_OP_RST:
1111                 virtio_transport_do_close(vsk, true);
1112                 break;
1113         default:
1114                 err = -EINVAL;
1115                 break;
1116         }
1117
1118         virtio_transport_free_pkt(pkt);
1119         return err;
1120 }
1121
1122 static void
1123 virtio_transport_recv_disconnecting(struct sock *sk,
1124                                     struct virtio_vsock_pkt *pkt)
1125 {
1126         struct vsock_sock *vsk = vsock_sk(sk);
1127
1128         if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
1129                 virtio_transport_do_close(vsk, true);
1130 }
1131
1132 static int
1133 virtio_transport_send_response(struct vsock_sock *vsk,
1134                                struct virtio_vsock_pkt *pkt)
1135 {
1136         struct virtio_vsock_pkt_info info = {
1137                 .op = VIRTIO_VSOCK_OP_RESPONSE,
1138                 .remote_cid = le64_to_cpu(pkt->hdr.src_cid),
1139                 .remote_port = le32_to_cpu(pkt->hdr.src_port),
1140                 .reply = true,
1141                 .vsk = vsk,
1142         };
1143
1144         return virtio_transport_send_pkt_info(vsk, &info);
1145 }
1146
1147 static bool virtio_transport_space_update(struct sock *sk,
1148                                           struct virtio_vsock_pkt *pkt)
1149 {
1150         struct vsock_sock *vsk = vsock_sk(sk);
1151         struct virtio_vsock_sock *vvs = vsk->trans;
1152         bool space_available;
1153
1154         /* Listener sockets are not associated with any transport, so we are
1155          * not able to take the state to see if there is space available in the
1156          * remote peer, but since they are only used to receive requests, we
1157          * can assume that there is always space available in the other peer.
1158          */
1159         if (!vvs)
1160                 return true;
1161
1162         /* buf_alloc and fwd_cnt is always included in the hdr */
1163         spin_lock_bh(&vvs->tx_lock);
1164         vvs->peer_buf_alloc = le32_to_cpu(pkt->hdr.buf_alloc);
1165         vvs->peer_fwd_cnt = le32_to_cpu(pkt->hdr.fwd_cnt);
1166         space_available = virtio_transport_has_space(vsk);
1167         spin_unlock_bh(&vvs->tx_lock);
1168         return space_available;
1169 }
1170
1171 /* Handle server socket */
1172 static int
1173 virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt,
1174                              struct virtio_transport *t)
1175 {
1176         struct vsock_sock *vsk = vsock_sk(sk);
1177         struct vsock_sock *vchild;
1178         struct sock *child;
1179         int ret;
1180
1181         if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_REQUEST) {
1182                 virtio_transport_reset_no_sock(t, pkt);
1183                 return -EINVAL;
1184         }
1185
1186         if (sk_acceptq_is_full(sk)) {
1187                 virtio_transport_reset_no_sock(t, pkt);
1188                 return -ENOMEM;
1189         }
1190
1191         child = vsock_create_connected(sk);
1192         if (!child) {
1193                 virtio_transport_reset_no_sock(t, pkt);
1194                 return -ENOMEM;
1195         }
1196
1197         sk_acceptq_added(sk);
1198
1199         lock_sock_nested(child, SINGLE_DEPTH_NESTING);
1200
1201         child->sk_state = TCP_ESTABLISHED;
1202
1203         vchild = vsock_sk(child);
1204         vsock_addr_init(&vchild->local_addr, le64_to_cpu(pkt->hdr.dst_cid),
1205                         le32_to_cpu(pkt->hdr.dst_port));
1206         vsock_addr_init(&vchild->remote_addr, le64_to_cpu(pkt->hdr.src_cid),
1207                         le32_to_cpu(pkt->hdr.src_port));
1208
1209         ret = vsock_assign_transport(vchild, vsk);
1210         /* Transport assigned (looking at remote_addr) must be the same
1211          * where we received the request.
1212          */
1213         if (ret || vchild->transport != &t->transport) {
1214                 release_sock(child);
1215                 virtio_transport_reset_no_sock(t, pkt);
1216                 sock_put(child);
1217                 return ret;
1218         }
1219
1220         if (virtio_transport_space_update(child, pkt))
1221                 child->sk_write_space(child);
1222
1223         vsock_insert_connected(vchild);
1224         vsock_enqueue_accept(sk, child);
1225         virtio_transport_send_response(vchild, pkt);
1226
1227         release_sock(child);
1228
1229         sk->sk_data_ready(sk);
1230         return 0;
1231 }
1232
1233 static bool virtio_transport_valid_type(u16 type)
1234 {
1235         return (type == VIRTIO_VSOCK_TYPE_STREAM) ||
1236                (type == VIRTIO_VSOCK_TYPE_SEQPACKET);
1237 }
1238
1239 /* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
1240  * lock.
1241  */
1242 void virtio_transport_recv_pkt(struct virtio_transport *t,
1243                                struct virtio_vsock_pkt *pkt)
1244 {
1245         struct sockaddr_vm src, dst;
1246         struct vsock_sock *vsk;
1247         struct sock *sk;
1248         bool space_available;
1249
1250         vsock_addr_init(&src, le64_to_cpu(pkt->hdr.src_cid),
1251                         le32_to_cpu(pkt->hdr.src_port));
1252         vsock_addr_init(&dst, le64_to_cpu(pkt->hdr.dst_cid),
1253                         le32_to_cpu(pkt->hdr.dst_port));
1254
1255         trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
1256                                         dst.svm_cid, dst.svm_port,
1257                                         le32_to_cpu(pkt->hdr.len),
1258                                         le16_to_cpu(pkt->hdr.type),
1259                                         le16_to_cpu(pkt->hdr.op),
1260                                         le32_to_cpu(pkt->hdr.flags),
1261                                         le32_to_cpu(pkt->hdr.buf_alloc),
1262                                         le32_to_cpu(pkt->hdr.fwd_cnt));
1263
1264         if (!virtio_transport_valid_type(le16_to_cpu(pkt->hdr.type))) {
1265                 (void)virtio_transport_reset_no_sock(t, pkt);
1266                 goto free_pkt;
1267         }
1268
1269         /* The socket must be in connected or bound table
1270          * otherwise send reset back
1271          */
1272         sk = vsock_find_connected_socket(&src, &dst);
1273         if (!sk) {
1274                 sk = vsock_find_bound_socket(&dst);
1275                 if (!sk) {
1276                         (void)virtio_transport_reset_no_sock(t, pkt);
1277                         goto free_pkt;
1278                 }
1279         }
1280
1281         if (virtio_transport_get_type(sk) != le16_to_cpu(pkt->hdr.type)) {
1282                 (void)virtio_transport_reset_no_sock(t, pkt);
1283                 sock_put(sk);
1284                 goto free_pkt;
1285         }
1286
1287         vsk = vsock_sk(sk);
1288
1289         lock_sock(sk);
1290
1291         /* Check if sk has been closed before lock_sock */
1292         if (sock_flag(sk, SOCK_DONE)) {
1293                 (void)virtio_transport_reset_no_sock(t, pkt);
1294                 release_sock(sk);
1295                 sock_put(sk);
1296                 goto free_pkt;
1297         }
1298
1299         space_available = virtio_transport_space_update(sk, pkt);
1300
1301         /* Update CID in case it has changed after a transport reset event */
1302         vsk->local_addr.svm_cid = dst.svm_cid;
1303
1304         if (space_available)
1305                 sk->sk_write_space(sk);
1306
1307         switch (sk->sk_state) {
1308         case TCP_LISTEN:
1309                 virtio_transport_recv_listen(sk, pkt, t);
1310                 virtio_transport_free_pkt(pkt);
1311                 break;
1312         case TCP_SYN_SENT:
1313                 virtio_transport_recv_connecting(sk, pkt);
1314                 virtio_transport_free_pkt(pkt);
1315                 break;
1316         case TCP_ESTABLISHED:
1317                 virtio_transport_recv_connected(sk, pkt);
1318                 break;
1319         case TCP_CLOSING:
1320                 virtio_transport_recv_disconnecting(sk, pkt);
1321                 virtio_transport_free_pkt(pkt);
1322                 break;
1323         default:
1324                 (void)virtio_transport_reset_no_sock(t, pkt);
1325                 virtio_transport_free_pkt(pkt);
1326                 break;
1327         }
1328
1329         release_sock(sk);
1330
1331         /* Release refcnt obtained when we fetched this socket out of the
1332          * bound or connected list.
1333          */
1334         sock_put(sk);
1335         return;
1336
1337 free_pkt:
1338         virtio_transport_free_pkt(pkt);
1339 }
1340 EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
1341
1342 void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
1343 {
1344         kfree(pkt->buf);
1345         kfree(pkt);
1346 }
1347 EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);
1348
1349 MODULE_LICENSE("GPL v2");
1350 MODULE_AUTHOR("Asias He");
1351 MODULE_DESCRIPTION("common code for virtio vsock");