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