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