net/vmw_vsock/virtio_transport_common.c

   1 /*
   2  * common code for virtio vsock
   3  *
   4  * Copyright (C) 2013-2015 Red Hat, Inc.
   5  * Author: Asias He <asias@redhat.com>
   6  *         Stefan Hajnoczi <stefanha@redhat.com>
   7  *
   8  * This work is licensed under the terms of the GNU GPL, version 2.
   9  */
  10 #include <linux/spinlock.h>
  11 #include <linux/module.h>
  12 #include <linux/sched/signal.h>
  13 #include <linux/ctype.h>
  14 #include <linux/list.h>
  15 #include <linux/virtio.h>
  16 #include <linux/virtio_ids.h>
  17 #include <linux/virtio_config.h>
  18 #include <linux/virtio_vsock.h>
  19
  20 #include <net/sock.h>
  21 #include <net/af_vsock.h>
  22
  23 #define CREATE_TRACE_POINTS
  24 #include <trace/events/vsock_virtio_transport_common.h>
  25
  26 /* How long to wait for graceful shutdown of a connection */
  27 #define VSOCK_CLOSE_TIMEOUT (8 * HZ)
  28
  29 static const struct virtio_transport *virtio_transport_get_ops(void)
  30 {
  31         const struct vsock_transport *t = vsock_core_get_transport();
  32
  33         return container_of(t, struct virtio_transport, transport);
  34 }
  35
  36 static struct virtio_vsock_pkt *
  37 virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,
  38                            size_t len,
  39                            u32 src_cid,
  40                            u32 src_port,
  41                            u32 dst_cid,
  42                            u32 dst_port)
  43 {
  44         struct virtio_vsock_pkt *pkt;
  45         int err;
  46
  47         pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
  48         if (!pkt)
  49                 return NULL;
  50
  51         pkt->hdr.type           = cpu_to_le16(info->type);
  52         pkt->hdr.op             = cpu_to_le16(info->op);
  53         pkt->hdr.src_cid        = cpu_to_le64(src_cid);
  54         pkt->hdr.dst_cid        = cpu_to_le64(dst_cid);
  55         pkt->hdr.src_port       = cpu_to_le32(src_port);
  56         pkt->hdr.dst_port       = cpu_to_le32(dst_port);
  57         pkt->hdr.flags          = cpu_to_le32(info->flags);
  58         pkt->len                = len;
  59         pkt->hdr.len            = cpu_to_le32(len);
  60         pkt->reply              = info->reply;
  61         pkt->vsk                = info->vsk;
  62
  63         if (info->msg && len > 0) {
  64                 pkt->buf = kmalloc(len, GFP_KERNEL);
  65                 if (!pkt->buf)
  66                         goto out_pkt;
  67                 err = memcpy_from_msg(pkt->buf, info->msg, len);
  68                 if (err)
  69                         goto out;
  70         }
  71
  72         trace_virtio_transport_alloc_pkt(src_cid, src_port,
  73                                          dst_cid, dst_port,
  74                                          len,
  75                                          info->type,
  76                                          info->op,
  77                                          info->flags);
  78
  79         return pkt;
  80
  81 out:
  82         kfree(pkt->buf);
  83 out_pkt:
  84         kfree(pkt);
  85         return NULL;
  86 }
  87
  88 static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
  89                                           struct virtio_vsock_pkt_info *info)
  90 {
  91         u32 src_cid, src_port, dst_cid, dst_port;
  92         struct virtio_vsock_sock *vvs;
  93         struct virtio_vsock_pkt *pkt;
  94         u32 pkt_len = info->pkt_len;
  95
  96         src_cid = vm_sockets_get_local_cid();
  97         src_port = vsk->local_addr.svm_port;
  98         if (!info->remote_cid) {
  99                 dst_cid = vsk->remote_addr.svm_cid;
 100                 dst_port = vsk->remote_addr.svm_port;
 101         } else {
 102                 dst_cid = info->remote_cid;
 103                 dst_port = info->remote_port;
 104         }
 105
 106         vvs = vsk->trans;
 107
 108         /* we can send less than pkt_len bytes */
 109         if (pkt_len > VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE)
 110                 pkt_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
 111
 112         /* virtio_transport_get_credit might return less than pkt_len credit */
 113         pkt_len = virtio_transport_get_credit(vvs, pkt_len);
 114
 115         /* Do not send zero length OP_RW pkt */
 116         if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
 117                 return pkt_len;
 118
 119         pkt = virtio_transport_alloc_pkt(info, pkt_len,
 120                                          src_cid, src_port,
 121                                          dst_cid, dst_port);
 122         if (!pkt) {
 123                 virtio_transport_put_credit(vvs, pkt_len);
 124                 return -ENOMEM;
 125         }
 126
 127         virtio_transport_inc_tx_pkt(vvs, pkt);
 128
 129         return virtio_transport_get_ops()->send_pkt(pkt);
 130 }
 131
 132 static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
 133                                         struct virtio_vsock_pkt *pkt)
 134 {
 135         vvs->rx_bytes += pkt->len;
 136 }
 137
 138 static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
 139                                         struct virtio_vsock_pkt *pkt)
 140 {
 141         vvs->rx_bytes -= pkt->len;
 142         vvs->fwd_cnt += pkt->len;
 143 }
 144
 145 void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
 146 {
 147         spin_lock_bh(&vvs->tx_lock);
 148         pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
 149         pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
 150         spin_unlock_bh(&vvs->tx_lock);
 151 }
 152 EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
 153
 154 u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit)
 155 {
 156         u32 ret;
 157
 158         spin_lock_bh(&vvs->tx_lock);
 159         ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
 160         if (ret > credit)
 161                 ret = credit;
 162         vvs->tx_cnt += ret;
 163         spin_unlock_bh(&vvs->tx_lock);
 164
 165         return ret;
 166 }
 167 EXPORT_SYMBOL_GPL(virtio_transport_get_credit);
 168
 169 void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit)
 170 {
 171         spin_lock_bh(&vvs->tx_lock);
 172         vvs->tx_cnt -= credit;
 173         spin_unlock_bh(&vvs->tx_lock);
 174 }
 175 EXPORT_SYMBOL_GPL(virtio_transport_put_credit);
 176
 177 static int virtio_transport_send_credit_update(struct vsock_sock *vsk,
 178                                                int type,
 179                                                struct virtio_vsock_hdr *hdr)
 180 {
 181         struct virtio_vsock_pkt_info info = {
 182                 .op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
 183                 .type = type,
 184                 .vsk = vsk,
 185         };
 186
 187         return virtio_transport_send_pkt_info(vsk, &info);
 188 }
 189
 190 static ssize_t
 191 virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
 192                                    struct msghdr *msg,
 193                                    size_t len)
 194 {
 195         struct virtio_vsock_sock *vvs = vsk->trans;
 196         struct virtio_vsock_pkt *pkt;
 197         size_t bytes, total = 0;
 198         int err = -EFAULT;
 199
 200         spin_lock_bh(&vvs->rx_lock);
 201         while (total < len && !list_empty(&vvs->rx_queue)) {
 202                 pkt = list_first_entry(&vvs->rx_queue,
 203                                        struct virtio_vsock_pkt, list);
 204
 205                 bytes = len - total;
 206                 if (bytes > pkt->len - pkt->off)
 207                         bytes = pkt->len - pkt->off;
 208
 209                 /* sk_lock is held by caller so no one else can dequeue.
 210                  * Unlock rx_lock since memcpy_to_msg() may sleep.
 211                  */
 212                 spin_unlock_bh(&vvs->rx_lock);
 213
 214                 err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes);
 215                 if (err)
 216                         goto out;
 217
 218                 spin_lock_bh(&vvs->rx_lock);
 219
 220                 total += bytes;
 221                 pkt->off += bytes;
 222                 if (pkt->off == pkt->len) {
 223                         virtio_transport_dec_rx_pkt(vvs, pkt);
 224                         list_del(&pkt->list);
 225                         virtio_transport_free_pkt(pkt);
 226                 }
 227         }
 228         spin_unlock_bh(&vvs->rx_lock);
 229
 230         /* Send a credit pkt to peer */
 231         virtio_transport_send_credit_update(vsk, VIRTIO_VSOCK_TYPE_STREAM,
 232                                             NULL);
 233
 234         return total;
 235
 236 out:
 237         if (total)
 238                 err = total;
 239         return err;
 240 }
 241
 242 ssize_t
 243 virtio_transport_stream_dequeue(struct vsock_sock *vsk,
 244                                 struct msghdr *msg,
 245                                 size_t len, int flags)
 246 {
 247         if (flags & MSG_PEEK)
 248                 return -EOPNOTSUPP;
 249
 250         return virtio_transport_stream_do_dequeue(vsk, msg, len);
 251 }
 252 EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
 253
 254 int
 255 virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
 256                                struct msghdr *msg,
 257                                size_t len, int flags)
 258 {
 259         return -EOPNOTSUPP;
 260 }
 261 EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
 262
 263 s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
 264 {
 265         struct virtio_vsock_sock *vvs = vsk->trans;
 266         s64 bytes;
 267
 268         spin_lock_bh(&vvs->rx_lock);
 269         bytes = vvs->rx_bytes;
 270         spin_unlock_bh(&vvs->rx_lock);
 271
 272         return bytes;
 273 }
 274 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data);
 275
 276 static s64 virtio_transport_has_space(struct vsock_sock *vsk)
 277 {
 278         struct virtio_vsock_sock *vvs = vsk->trans;
 279         s64 bytes;
 280
 281         bytes = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
 282         if (bytes < 0)
 283                 bytes = 0;
 284
 285         return bytes;
 286 }
 287
 288 s64 virtio_transport_stream_has_space(struct vsock_sock *vsk)
 289 {
 290         struct virtio_vsock_sock *vvs = vsk->trans;
 291         s64 bytes;
 292
 293         spin_lock_bh(&vvs->tx_lock);
 294         bytes = virtio_transport_has_space(vsk);
 295         spin_unlock_bh(&vvs->tx_lock);
 296
 297         return bytes;
 298 }
 299 EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space);
 300
 301 int virtio_transport_do_socket_init(struct vsock_sock *vsk,
 302                                     struct vsock_sock *psk)
 303 {
 304         struct virtio_vsock_sock *vvs;
 305
 306         vvs = kzalloc(sizeof(*vvs), GFP_KERNEL);
 307         if (!vvs)
 308                 return -ENOMEM;
 309
 310         vsk->trans = vvs;
 311         vvs->vsk = vsk;
 312         if (psk) {
 313                 struct virtio_vsock_sock *ptrans = psk->trans;
 314
 315                 vvs->buf_size   = ptrans->buf_size;
 316                 vvs->buf_size_min = ptrans->buf_size_min;
 317                 vvs->buf_size_max = ptrans->buf_size_max;
 318                 vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
 319         } else {
 320                 vvs->buf_size = VIRTIO_VSOCK_DEFAULT_BUF_SIZE;
 321                 vvs->buf_size_min = VIRTIO_VSOCK_DEFAULT_MIN_BUF_SIZE;
 322                 vvs->buf_size_max = VIRTIO_VSOCK_DEFAULT_MAX_BUF_SIZE;
 323         }
 324
 325         vvs->buf_alloc = vvs->buf_size;
 326
 327         spin_lock_init(&vvs->rx_lock);
 328         spin_lock_init(&vvs->tx_lock);
 329         INIT_LIST_HEAD(&vvs->rx_queue);
 330
 331         return 0;
 332 }
 333 EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init);
 334
 335 u64 virtio_transport_get_buffer_size(struct vsock_sock *vsk)
 336 {
 337         struct virtio_vsock_sock *vvs = vsk->trans;
 338
 339         return vvs->buf_size;
 340 }
 341 EXPORT_SYMBOL_GPL(virtio_transport_get_buffer_size);
 342
 343 u64 virtio_transport_get_min_buffer_size(struct vsock_sock *vsk)
 344 {
 345         struct virtio_vsock_sock *vvs = vsk->trans;
 346
 347         return vvs->buf_size_min;
 348 }
 349 EXPORT_SYMBOL_GPL(virtio_transport_get_min_buffer_size);
 350
 351 u64 virtio_transport_get_max_buffer_size(struct vsock_sock *vsk)
 352 {
 353         struct virtio_vsock_sock *vvs = vsk->trans;
 354
 355         return vvs->buf_size_max;
 356 }
 357 EXPORT_SYMBOL_GPL(virtio_transport_get_max_buffer_size);
 358
 359 void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val)
 360 {
 361         struct virtio_vsock_sock *vvs = vsk->trans;
 362
 363         if (val > VIRTIO_VSOCK_MAX_BUF_SIZE)
 364                 val = VIRTIO_VSOCK_MAX_BUF_SIZE;
 365         if (val < vvs->buf_size_min)
 366                 vvs->buf_size_min = val;
 367         if (val > vvs->buf_size_max)
 368                 vvs->buf_size_max = val;
 369         vvs->buf_size = val;
 370         vvs->buf_alloc = val;
 371 }
 372 EXPORT_SYMBOL_GPL(virtio_transport_set_buffer_size);
 373
 374 void virtio_transport_set_min_buffer_size(struct vsock_sock *vsk, u64 val)
 375 {
 376         struct virtio_vsock_sock *vvs = vsk->trans;
 377
 378         if (val > VIRTIO_VSOCK_MAX_BUF_SIZE)
 379                 val = VIRTIO_VSOCK_MAX_BUF_SIZE;
 380         if (val > vvs->buf_size)
 381                 vvs->buf_size = val;
 382         vvs->buf_size_min = val;
 383 }
 384 EXPORT_SYMBOL_GPL(virtio_transport_set_min_buffer_size);
 385
 386 void virtio_transport_set_max_buffer_size(struct vsock_sock *vsk, u64 val)
 387 {
 388         struct virtio_vsock_sock *vvs = vsk->trans;
 389
 390         if (val > VIRTIO_VSOCK_MAX_BUF_SIZE)
 391                 val = VIRTIO_VSOCK_MAX_BUF_SIZE;
 392         if (val < vvs->buf_size)
 393                 vvs->buf_size = val;
 394         vvs->buf_size_max = val;
 395 }
 396 EXPORT_SYMBOL_GPL(virtio_transport_set_max_buffer_size);
 397
 398 int
 399 virtio_transport_notify_poll_in(struct vsock_sock *vsk,
 400                                 size_t target,
 401                                 bool *data_ready_now)
 402 {
 403         if (vsock_stream_has_data(vsk))
 404                 *data_ready_now = true;
 405         else
 406                 *data_ready_now = false;
 407
 408         return 0;
 409 }
 410 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in);
 411
 412 int
 413 virtio_transport_notify_poll_out(struct vsock_sock *vsk,
 414                                  size_t target,
 415                                  bool *space_avail_now)
 416 {
 417         s64 free_space;
 418
 419         free_space = vsock_stream_has_space(vsk);
 420         if (free_space > 0)
 421                 *space_avail_now = true;
 422         else if (free_space == 0)
 423                 *space_avail_now = false;
 424
 425         return 0;
 426 }
 427 EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out);
 428
 429 int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
 430         size_t target, struct vsock_transport_recv_notify_data *data)
 431 {
 432         return 0;
 433 }
 434 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init);
 435
 436 int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
 437         size_t target, struct vsock_transport_recv_notify_data *data)
 438 {
 439         return 0;
 440 }
 441 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block);
 442
 443 int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
 444         size_t target, struct vsock_transport_recv_notify_data *data)
 445 {
 446         return 0;
 447 }
 448 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue);
 449
 450 int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
 451         size_t target, ssize_t copied, bool data_read,
 452         struct vsock_transport_recv_notify_data *data)
 453 {
 454         return 0;
 455 }
 456 EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue);
 457
 458 int virtio_transport_notify_send_init(struct vsock_sock *vsk,
 459         struct vsock_transport_send_notify_data *data)
 460 {
 461         return 0;
 462 }
 463 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init);
 464
 465 int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
 466         struct vsock_transport_send_notify_data *data)
 467 {
 468         return 0;
 469 }
 470 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block);
 471
 472 int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
 473         struct vsock_transport_send_notify_data *data)
 474 {
 475         return 0;
 476 }
 477 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue);
 478
 479 int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
 480         ssize_t written, struct vsock_transport_send_notify_data *data)
 481 {
 482         return 0;
 483 }
 484 EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue);
 485
 486 u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk)
 487 {
 488         struct virtio_vsock_sock *vvs = vsk->trans;
 489
 490         return vvs->buf_size;
 491 }
 492 EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat);
 493
 494 bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
 495 {
 496         return true;
 497 }
 498 EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
 499
 500 bool virtio_transport_stream_allow(u32 cid, u32 port)
 501 {
 502         return true;
 503 }
 504 EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
 505
 506 int virtio_transport_dgram_bind(struct vsock_sock *vsk,
 507                                 struct sockaddr_vm *addr)
 508 {
 509         return -EOPNOTSUPP;
 510 }
 511 EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
 512
 513 bool virtio_transport_dgram_allow(u32 cid, u32 port)
 514 {
 515         return false;
 516 }
 517 EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
 518
 519 int virtio_transport_connect(struct vsock_sock *vsk)
 520 {
 521         struct virtio_vsock_pkt_info info = {
 522                 .op = VIRTIO_VSOCK_OP_REQUEST,
 523                 .type = VIRTIO_VSOCK_TYPE_STREAM,
 524                 .vsk = vsk,
 525         };
 526
 527         return virtio_transport_send_pkt_info(vsk, &info);
 528 }
 529 EXPORT_SYMBOL_GPL(virtio_transport_connect);
 530
 531 int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
 532 {
 533         struct virtio_vsock_pkt_info info = {
 534                 .op = VIRTIO_VSOCK_OP_SHUTDOWN,
 535                 .type = VIRTIO_VSOCK_TYPE_STREAM,
 536                 .flags = (mode & RCV_SHUTDOWN ?
 537                           VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
 538                          (mode & SEND_SHUTDOWN ?
 539                           VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
 540                 .vsk = vsk,
 541         };
 542
 543         return virtio_transport_send_pkt_info(vsk, &info);
 544 }
 545 EXPORT_SYMBOL_GPL(virtio_transport_shutdown);
 546
 547 int
 548 virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
 549                                struct sockaddr_vm *remote_addr,
 550                                struct msghdr *msg,
 551                                size_t dgram_len)
 552 {
 553         return -EOPNOTSUPP;
 554 }
 555 EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
 556
 557 ssize_t
 558 virtio_transport_stream_enqueue(struct vsock_sock *vsk,
 559                                 struct msghdr *msg,
 560                                 size_t len)
 561 {
 562         struct virtio_vsock_pkt_info info = {
 563                 .op = VIRTIO_VSOCK_OP_RW,
 564                 .type = VIRTIO_VSOCK_TYPE_STREAM,
 565                 .msg = msg,
 566                 .pkt_len = len,
 567                 .vsk = vsk,
 568         };
 569
 570         return virtio_transport_send_pkt_info(vsk, &info);
 571 }
 572 EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);
 573
 574 void virtio_transport_destruct(struct vsock_sock *vsk)
 575 {
 576         struct virtio_vsock_sock *vvs = vsk->trans;
 577
 578         kfree(vvs);
 579 }
 580 EXPORT_SYMBOL_GPL(virtio_transport_destruct);
 581
 582 static int virtio_transport_reset(struct vsock_sock *vsk,
 583                                   struct virtio_vsock_pkt *pkt)
 584 {
 585         struct virtio_vsock_pkt_info info = {
 586                 .op = VIRTIO_VSOCK_OP_RST,
 587                 .type = VIRTIO_VSOCK_TYPE_STREAM,
 588                 .reply = !!pkt,
 589                 .vsk = vsk,
 590         };
 591
 592         /* Send RST only if the original pkt is not a RST pkt */
 593         if (pkt && le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
 594                 return 0;
 595
 596         return virtio_transport_send_pkt_info(vsk, &info);
 597 }
 598
 599 /* Normally packets are associated with a socket.  There may be no socket if an
 600  * attempt was made to connect to a socket that does not exist.
 601  */
 602 static int virtio_transport_reset_no_sock(struct virtio_vsock_pkt *pkt)
 603 {
 604         struct virtio_vsock_pkt_info info = {
 605                 .op = VIRTIO_VSOCK_OP_RST,
 606                 .type = le16_to_cpu(pkt->hdr.type),
 607                 .reply = true,
 608         };
 609
 610         /* Send RST only if the original pkt is not a RST pkt */
 611         if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
 612                 return 0;
 613
 614         pkt = virtio_transport_alloc_pkt(&info, 0,
 615                                          le64_to_cpu(pkt->hdr.dst_cid),
 616                                          le32_to_cpu(pkt->hdr.dst_port),
 617                                          le64_to_cpu(pkt->hdr.src_cid),
 618                                          le32_to_cpu(pkt->hdr.src_port));
 619         if (!pkt)
 620                 return -ENOMEM;
 621
 622         return virtio_transport_get_ops()->send_pkt(pkt);
 623 }
 624
 625 static void virtio_transport_wait_close(struct sock *sk, long timeout)
 626 {
 627         if (timeout) {
 628                 DEFINE_WAIT_FUNC(wait, woken_wake_function);
 629
 630                 add_wait_queue(sk_sleep(sk), &wait);
 631
 632                 do {
 633                         if (sk_wait_event(sk, &timeout,
 634                                           sock_flag(sk, SOCK_DONE), &wait))
 635                                 break;
 636                 } while (!signal_pending(current) && timeout);
 637
 638                 remove_wait_queue(sk_sleep(sk), &wait);
 639         }
 640 }
 641
 642 static void virtio_transport_do_close(struct vsock_sock *vsk,
 643                                       bool cancel_timeout)
 644 {
 645         struct sock *sk = sk_vsock(vsk);
 646
 647         sock_set_flag(sk, SOCK_DONE);
 648         vsk->peer_shutdown = SHUTDOWN_MASK;
 649         if (vsock_stream_has_data(vsk) <= 0)
 650                 sk->sk_state = SS_DISCONNECTING;
 651         sk->sk_state_change(sk);
 652
 653         if (vsk->close_work_scheduled &&
 654             (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
 655                 vsk->close_work_scheduled = false;
 656
 657                 vsock_remove_sock(vsk);
 658
 659                 /* Release refcnt obtained when we scheduled the timeout */
 660                 sock_put(sk);
 661         }
 662 }
 663
 664 static void virtio_transport_close_timeout(struct work_struct *work)
 665 {
 666         struct vsock_sock *vsk =
 667                 container_of(work, struct vsock_sock, close_work.work);
 668         struct sock *sk = sk_vsock(vsk);
 669
 670         sock_hold(sk);
 671         lock_sock(sk);
 672
 673         if (!sock_flag(sk, SOCK_DONE)) {
 674                 (void)virtio_transport_reset(vsk, NULL);
 675
 676                 virtio_transport_do_close(vsk, false);
 677         }
 678
 679         vsk->close_work_scheduled = false;
 680
 681         release_sock(sk);
 682         sock_put(sk);
 683 }
 684
 685 /* User context, vsk->sk is locked */
 686 static bool virtio_transport_close(struct vsock_sock *vsk)
 687 {
 688         struct sock *sk = &vsk->sk;
 689
 690         if (!(sk->sk_state == SS_CONNECTED ||
 691               sk->sk_state == SS_DISCONNECTING))
 692                 return true;
 693
 694         /* Already received SHUTDOWN from peer, reply with RST */
 695         if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) {
 696                 (void)virtio_transport_reset(vsk, NULL);
 697                 return true;
 698         }
 699
 700         if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
 701                 (void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
 702
 703         if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
 704                 virtio_transport_wait_close(sk, sk->sk_lingertime);
 705
 706         if (sock_flag(sk, SOCK_DONE)) {
 707                 return true;
 708         }
 709
 710         sock_hold(sk);
 711         INIT_DELAYED_WORK(&vsk->close_work,
 712                           virtio_transport_close_timeout);
 713         vsk->close_work_scheduled = true;
 714         schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT);
 715         return false;
 716 }
 717
 718 void virtio_transport_release(struct vsock_sock *vsk)
 719 {
 720         struct sock *sk = &vsk->sk;
 721         bool remove_sock = true;
 722
 723         lock_sock(sk);
 724         if (sk->sk_type == SOCK_STREAM)
 725                 remove_sock = virtio_transport_close(vsk);
 726         release_sock(sk);
 727
 728         if (remove_sock)
 729                 vsock_remove_sock(vsk);
 730 }
 731 EXPORT_SYMBOL_GPL(virtio_transport_release);
 732
 733 static int
 734 virtio_transport_recv_connecting(struct sock *sk,
 735                                  struct virtio_vsock_pkt *pkt)
 736 {
 737         struct vsock_sock *vsk = vsock_sk(sk);
 738         int err;
 739         int skerr;
 740
 741         switch (le16_to_cpu(pkt->hdr.op)) {
 742         case VIRTIO_VSOCK_OP_RESPONSE:
 743                 sk->sk_state = SS_CONNECTED;
 744                 sk->sk_socket->state = SS_CONNECTED;
 745                 vsock_insert_connected(vsk);
 746                 sk->sk_state_change(sk);
 747                 break;
 748         case VIRTIO_VSOCK_OP_INVALID:
 749                 break;
 750         case VIRTIO_VSOCK_OP_RST:
 751                 skerr = ECONNRESET;
 752                 err = 0;
 753                 goto destroy;
 754         default:
 755                 skerr = EPROTO;
 756                 err = -EINVAL;
 757                 goto destroy;
 758         }
 759         return 0;
 760
 761 destroy:
 762         virtio_transport_reset(vsk, pkt);
 763         sk->sk_state = SS_UNCONNECTED;
 764         sk->sk_err = skerr;
 765         sk->sk_error_report(sk);
 766         return err;
 767 }
 768
 769 static int
 770 virtio_transport_recv_connected(struct sock *sk,
 771                                 struct virtio_vsock_pkt *pkt)
 772 {
 773         struct vsock_sock *vsk = vsock_sk(sk);
 774         struct virtio_vsock_sock *vvs = vsk->trans;
 775         int err = 0;
 776
 777         switch (le16_to_cpu(pkt->hdr.op)) {
 778         case VIRTIO_VSOCK_OP_RW:
 779                 pkt->len = le32_to_cpu(pkt->hdr.len);
 780                 pkt->off = 0;
 781
 782                 spin_lock_bh(&vvs->rx_lock);
 783                 virtio_transport_inc_rx_pkt(vvs, pkt);
 784                 list_add_tail(&pkt->list, &vvs->rx_queue);
 785                 spin_unlock_bh(&vvs->rx_lock);
 786
 787                 sk->sk_data_ready(sk);
 788                 return err;
 789         case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
 790                 sk->sk_write_space(sk);
 791                 break;
 792         case VIRTIO_VSOCK_OP_SHUTDOWN:
 793                 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
 794                         vsk->peer_shutdown |= RCV_SHUTDOWN;
 795                 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
 796                         vsk->peer_shutdown |= SEND_SHUTDOWN;
 797                 if (vsk->peer_shutdown == SHUTDOWN_MASK &&
 798                     vsock_stream_has_data(vsk) <= 0)
 799                         sk->sk_state = SS_DISCONNECTING;
 800                 if (le32_to_cpu(pkt->hdr.flags))
 801                         sk->sk_state_change(sk);
 802                 break;
 803         case VIRTIO_VSOCK_OP_RST:
 804                 virtio_transport_do_close(vsk, true);
 805                 break;
 806         default:
 807                 err = -EINVAL;
 808                 break;
 809         }
 810
 811         virtio_transport_free_pkt(pkt);
 812         return err;
 813 }
 814
 815 static void
 816 virtio_transport_recv_disconnecting(struct sock *sk,
 817                                     struct virtio_vsock_pkt *pkt)
 818 {
 819         struct vsock_sock *vsk = vsock_sk(sk);
 820
 821         if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
 822                 virtio_transport_do_close(vsk, true);
 823 }
 824
 825 static int
 826 virtio_transport_send_response(struct vsock_sock *vsk,
 827                                struct virtio_vsock_pkt *pkt)
 828 {
 829         struct virtio_vsock_pkt_info info = {
 830                 .op = VIRTIO_VSOCK_OP_RESPONSE,
 831                 .type = VIRTIO_VSOCK_TYPE_STREAM,
 832                 .remote_cid = le64_to_cpu(pkt->hdr.src_cid),
 833                 .remote_port = le32_to_cpu(pkt->hdr.src_port),
 834                 .reply = true,
 835                 .vsk = vsk,
 836         };
 837
 838         return virtio_transport_send_pkt_info(vsk, &info);
 839 }
 840
 841 /* Handle server socket */
 842 static int
 843 virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt)
 844 {
 845         struct vsock_sock *vsk = vsock_sk(sk);
 846         struct vsock_sock *vchild;
 847         struct sock *child;
 848
 849         if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_REQUEST) {
 850                 virtio_transport_reset(vsk, pkt);
 851                 return -EINVAL;
 852         }
 853
 854         if (sk_acceptq_is_full(sk)) {
 855                 virtio_transport_reset(vsk, pkt);
 856                 return -ENOMEM;
 857         }
 858
 859         child = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL,
 860                                sk->sk_type, 0);
 861         if (!child) {
 862                 virtio_transport_reset(vsk, pkt);
 863                 return -ENOMEM;
 864         }
 865
 866         sk->sk_ack_backlog++;
 867
 868         lock_sock_nested(child, SINGLE_DEPTH_NESTING);
 869
 870         child->sk_state = SS_CONNECTED;
 871
 872         vchild = vsock_sk(child);
 873         vsock_addr_init(&vchild->local_addr, le64_to_cpu(pkt->hdr.dst_cid),
 874                         le32_to_cpu(pkt->hdr.dst_port));
 875         vsock_addr_init(&vchild->remote_addr, le64_to_cpu(pkt->hdr.src_cid),
 876                         le32_to_cpu(pkt->hdr.src_port));
 877
 878         vsock_insert_connected(vchild);
 879         vsock_enqueue_accept(sk, child);
 880         virtio_transport_send_response(vchild, pkt);
 881
 882         release_sock(child);
 883
 884         sk->sk_data_ready(sk);
 885         return 0;
 886 }
 887
 888 static bool virtio_transport_space_update(struct sock *sk,
 889                                           struct virtio_vsock_pkt *pkt)
 890 {
 891         struct vsock_sock *vsk = vsock_sk(sk);
 892         struct virtio_vsock_sock *vvs = vsk->trans;
 893         bool space_available;
 894
 895         /* buf_alloc and fwd_cnt is always included in the hdr */
 896         spin_lock_bh(&vvs->tx_lock);
 897         vvs->peer_buf_alloc = le32_to_cpu(pkt->hdr.buf_alloc);
 898         vvs->peer_fwd_cnt = le32_to_cpu(pkt->hdr.fwd_cnt);
 899         space_available = virtio_transport_has_space(vsk);
 900         spin_unlock_bh(&vvs->tx_lock);
 901         return space_available;
 902 }
 903
 904 /* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
 905  * lock.
 906  */
 907 void virtio_transport_recv_pkt(struct virtio_vsock_pkt *pkt)
 908 {
 909         struct sockaddr_vm src, dst;
 910         struct vsock_sock *vsk;
 911         struct sock *sk;
 912         bool space_available;
 913
 914         vsock_addr_init(&src, le64_to_cpu(pkt->hdr.src_cid),
 915                         le32_to_cpu(pkt->hdr.src_port));
 916         vsock_addr_init(&dst, le64_to_cpu(pkt->hdr.dst_cid),
 917                         le32_to_cpu(pkt->hdr.dst_port));
 918
 919         trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
 920                                         dst.svm_cid, dst.svm_port,
 921                                         le32_to_cpu(pkt->hdr.len),
 922                                         le16_to_cpu(pkt->hdr.type),
 923                                         le16_to_cpu(pkt->hdr.op),
 924                                         le32_to_cpu(pkt->hdr.flags),
 925                                         le32_to_cpu(pkt->hdr.buf_alloc),
 926                                         le32_to_cpu(pkt->hdr.fwd_cnt));
 927
 928         if (le16_to_cpu(pkt->hdr.type) != VIRTIO_VSOCK_TYPE_STREAM) {
 929                 (void)virtio_transport_reset_no_sock(pkt);
 930                 goto free_pkt;
 931         }
 932
 933         /* The socket must be in connected or bound table
 934          * otherwise send reset back
 935          */
 936         sk = vsock_find_connected_socket(&src, &dst);
 937         if (!sk) {
 938                 sk = vsock_find_bound_socket(&dst);
 939                 if (!sk) {
 940                         (void)virtio_transport_reset_no_sock(pkt);
 941                         goto free_pkt;
 942                 }
 943         }
 944
 945         vsk = vsock_sk(sk);
 946
 947         space_available = virtio_transport_space_update(sk, pkt);
 948
 949         lock_sock(sk);
 950
 951         /* Update CID in case it has changed after a transport reset event */
 952         vsk->local_addr.svm_cid = dst.svm_cid;
 953
 954         if (space_available)
 955                 sk->sk_write_space(sk);
 956
 957         switch (sk->sk_state) {
 958         case VSOCK_SS_LISTEN:
 959                 virtio_transport_recv_listen(sk, pkt);
 960                 virtio_transport_free_pkt(pkt);
 961                 break;
 962         case SS_CONNECTING:
 963                 virtio_transport_recv_connecting(sk, pkt);
 964                 virtio_transport_free_pkt(pkt);
 965                 break;
 966         case SS_CONNECTED:
 967                 virtio_transport_recv_connected(sk, pkt);
 968                 break;
 969         case SS_DISCONNECTING:
 970                 virtio_transport_recv_disconnecting(sk, pkt);
 971                 virtio_transport_free_pkt(pkt);
 972                 break;
 973         default:
 974                 virtio_transport_free_pkt(pkt);
 975                 break;
 976         }
 977         release_sock(sk);
 978
 979         /* Release refcnt obtained when we fetched this socket out of the
 980          * bound or connected list.
 981          */
 982         sock_put(sk);
 983         return;
 984
 985 free_pkt:
 986         virtio_transport_free_pkt(pkt);
 987 }
 988 EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
 989
 990 void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
 991 {
 992         kfree(pkt->buf);
 993         kfree(pkt);
 994 }
 995 EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);
 996
 997 MODULE_LICENSE("GPL v2");
 998 MODULE_AUTHOR("Asias He");
 999 MODULE_DESCRIPTION("common code for virtio vsock");