1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Hyper-V transport for vsock 4 * 5 * Hyper-V Sockets supplies a byte-stream based communication mechanism 6 * between the host and the VM. This driver implements the necessary 7 * support in the VM by introducing the new vsock transport. 8 * 9 * Copyright (c) 2017, Microsoft Corporation. 10 */ 11 #include <linux/module.h> 12 #include <linux/vmalloc.h> 13 #include <linux/hyperv.h> 14 #include <net/sock.h> 15 #include <net/af_vsock.h> 16 17 /* Older (VMBUS version 'VERSION_WIN10' or before) Windows hosts have some 18 * stricter requirements on the hv_sock ring buffer size of six 4K pages. Newer 19 * hosts don't have this limitation; but, keep the defaults the same for compat. 20 */ 21 #define PAGE_SIZE_4K 4096 22 #define RINGBUFFER_HVS_RCV_SIZE (PAGE_SIZE_4K * 6) 23 #define RINGBUFFER_HVS_SND_SIZE (PAGE_SIZE_4K * 6) 24 #define RINGBUFFER_HVS_MAX_SIZE (PAGE_SIZE_4K * 64) 25 26 /* The MTU is 16KB per the host side's design */ 27 #define HVS_MTU_SIZE (1024 * 16) 28 29 /* How long to wait for graceful shutdown of a connection */ 30 #define HVS_CLOSE_TIMEOUT (8 * HZ) 31 32 struct vmpipe_proto_header { 33 u32 pkt_type; 34 u32 data_size; 35 }; 36 37 /* For recv, we use the VMBus in-place packet iterator APIs to directly copy 38 * data from the ringbuffer into the userspace buffer. 39 */ 40 struct hvs_recv_buf { 41 /* The header before the payload data */ 42 struct vmpipe_proto_header hdr; 43 44 /* The payload */ 45 u8 data[HVS_MTU_SIZE]; 46 }; 47 48 /* We can send up to HVS_MTU_SIZE bytes of payload to the host, but let's use 49 * a smaller size, i.e. HVS_SEND_BUF_SIZE, to maximize concurrency between the 50 * guest and the host processing as one VMBUS packet is the smallest processing 51 * unit. 52 * 53 * Note: the buffer can be eliminated in the future when we add new VMBus 54 * ringbuffer APIs that allow us to directly copy data from userspace buffer 55 * to VMBus ringbuffer. 56 */ 57 #define HVS_SEND_BUF_SIZE (PAGE_SIZE_4K - sizeof(struct vmpipe_proto_header)) 58 59 struct hvs_send_buf { 60 /* The header before the payload data */ 61 struct vmpipe_proto_header hdr; 62 63 /* The payload */ 64 u8 data[HVS_SEND_BUF_SIZE]; 65 }; 66 67 #define HVS_HEADER_LEN (sizeof(struct vmpacket_descriptor) + \ 68 sizeof(struct vmpipe_proto_header)) 69 70 /* See 'prev_indices' in hv_ringbuffer_read(), hv_ringbuffer_write(), and 71 * __hv_pkt_iter_next(). 72 */ 73 #define VMBUS_PKT_TRAILER_SIZE (sizeof(u64)) 74 75 #define HVS_PKT_LEN(payload_len) (HVS_HEADER_LEN + \ 76 ALIGN((payload_len), 8) + \ 77 VMBUS_PKT_TRAILER_SIZE) 78 79 union hvs_service_id { 80 guid_t srv_id; 81 82 struct { 83 unsigned int svm_port; 84 unsigned char b[sizeof(guid_t) - sizeof(unsigned int)]; 85 }; 86 }; 87 88 /* Per-socket state (accessed via vsk->trans) */ 89 struct hvsock { 90 struct vsock_sock *vsk; 91 92 guid_t vm_srv_id; 93 guid_t host_srv_id; 94 95 struct vmbus_channel *chan; 96 struct vmpacket_descriptor *recv_desc; 97 98 /* The length of the payload not delivered to userland yet */ 99 u32 recv_data_len; 100 /* The offset of the payload */ 101 u32 recv_data_off; 102 103 /* Have we sent the zero-length packet (FIN)? */ 104 bool fin_sent; 105 }; 106 107 /* In the VM, we support Hyper-V Sockets with AF_VSOCK, and the endpoint is 108 * <cid, port> (see struct sockaddr_vm). Note: cid is not really used here: 109 * when we write apps to connect to the host, we can only use VMADDR_CID_ANY 110 * or VMADDR_CID_HOST (both are equivalent) as the remote cid, and when we 111 * write apps to bind() & listen() in the VM, we can only use VMADDR_CID_ANY 112 * as the local cid. 113 * 114 * On the host, Hyper-V Sockets are supported by Winsock AF_HYPERV: 115 * https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user- 116 * guide/make-integration-service, and the endpoint is <VmID, ServiceId> with 117 * the below sockaddr: 118 * 119 * struct SOCKADDR_HV 120 * { 121 * ADDRESS_FAMILY Family; 122 * USHORT Reserved; 123 * GUID VmId; 124 * GUID ServiceId; 125 * }; 126 * Note: VmID is not used by Linux VM and actually it isn't transmitted via 127 * VMBus, because here it's obvious the host and the VM can easily identify 128 * each other. Though the VmID is useful on the host, especially in the case 129 * of Windows container, Linux VM doesn't need it at all. 130 * 131 * To make use of the AF_VSOCK infrastructure in Linux VM, we have to limit 132 * the available GUID space of SOCKADDR_HV so that we can create a mapping 133 * between AF_VSOCK port and SOCKADDR_HV Service GUID. The rule of writing 134 * Hyper-V Sockets apps on the host and in Linux VM is: 135 * 136 **************************************************************************** 137 * The only valid Service GUIDs, from the perspectives of both the host and * 138 * Linux VM, that can be connected by the other end, must conform to this * 139 * format: <port>-facb-11e6-bd58-64006a7986d3, and the "port" must be in * 140 * this range [0, 0x7FFFFFFF]. * 141 **************************************************************************** 142 * 143 * When we write apps on the host to connect(), the GUID ServiceID is used. 144 * When we write apps in Linux VM to connect(), we only need to specify the 145 * port and the driver will form the GUID and use that to request the host. 146 * 147 * From the perspective of Linux VM: 148 * 1. the local ephemeral port (i.e. the local auto-bound port when we call 149 * connect() without explicit bind()) is generated by __vsock_bind_stream(), 150 * and the range is [1024, 0xFFFFFFFF). 151 * 2. the remote ephemeral port (i.e. the auto-generated remote port for 152 * a connect request initiated by the host's connect()) is generated by 153 * hvs_remote_addr_init() and the range is [0x80000000, 0xFFFFFFFF). 154 */ 155 156 #define MAX_LISTEN_PORT ((u32)0x7FFFFFFF) 157 #define MAX_VM_LISTEN_PORT MAX_LISTEN_PORT 158 #define MAX_HOST_LISTEN_PORT MAX_LISTEN_PORT 159 #define MIN_HOST_EPHEMERAL_PORT (MAX_HOST_LISTEN_PORT + 1) 160 161 /* 00000000-facb-11e6-bd58-64006a7986d3 */ 162 static const guid_t srv_id_template = 163 GUID_INIT(0x00000000, 0xfacb, 0x11e6, 0xbd, 0x58, 164 0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3); 165 166 static bool is_valid_srv_id(const guid_t *id) 167 { 168 return !memcmp(&id->b[4], &srv_id_template.b[4], sizeof(guid_t) - 4); 169 } 170 171 static unsigned int get_port_by_srv_id(const guid_t *svr_id) 172 { 173 return *((unsigned int *)svr_id); 174 } 175 176 static void hvs_addr_init(struct sockaddr_vm *addr, const guid_t *svr_id) 177 { 178 unsigned int port = get_port_by_srv_id(svr_id); 179 180 vsock_addr_init(addr, VMADDR_CID_ANY, port); 181 } 182 183 static void hvs_remote_addr_init(struct sockaddr_vm *remote, 184 struct sockaddr_vm *local) 185 { 186 static u32 host_ephemeral_port = MIN_HOST_EPHEMERAL_PORT; 187 struct sock *sk; 188 189 vsock_addr_init(remote, VMADDR_CID_ANY, VMADDR_PORT_ANY); 190 191 while (1) { 192 /* Wrap around ? */ 193 if (host_ephemeral_port < MIN_HOST_EPHEMERAL_PORT || 194 host_ephemeral_port == VMADDR_PORT_ANY) 195 host_ephemeral_port = MIN_HOST_EPHEMERAL_PORT; 196 197 remote->svm_port = host_ephemeral_port++; 198 199 sk = vsock_find_connected_socket(remote, local); 200 if (!sk) { 201 /* Found an available ephemeral port */ 202 return; 203 } 204 205 /* Release refcnt got in vsock_find_connected_socket */ 206 sock_put(sk); 207 } 208 } 209 210 static void hvs_set_channel_pending_send_size(struct vmbus_channel *chan) 211 { 212 set_channel_pending_send_size(chan, 213 HVS_PKT_LEN(HVS_SEND_BUF_SIZE)); 214 215 virt_mb(); 216 } 217 218 static bool hvs_channel_readable(struct vmbus_channel *chan) 219 { 220 u32 readable = hv_get_bytes_to_read(&chan->inbound); 221 222 /* 0-size payload means FIN */ 223 return readable >= HVS_PKT_LEN(0); 224 } 225 226 static int hvs_channel_readable_payload(struct vmbus_channel *chan) 227 { 228 u32 readable = hv_get_bytes_to_read(&chan->inbound); 229 230 if (readable > HVS_PKT_LEN(0)) { 231 /* At least we have 1 byte to read. We don't need to return 232 * the exact readable bytes: see vsock_stream_recvmsg() -> 233 * vsock_stream_has_data(). 234 */ 235 return 1; 236 } 237 238 if (readable == HVS_PKT_LEN(0)) { 239 /* 0-size payload means FIN */ 240 return 0; 241 } 242 243 /* No payload or FIN */ 244 return -1; 245 } 246 247 static size_t hvs_channel_writable_bytes(struct vmbus_channel *chan) 248 { 249 u32 writeable = hv_get_bytes_to_write(&chan->outbound); 250 size_t ret; 251 252 /* The ringbuffer mustn't be 100% full, and we should reserve a 253 * zero-length-payload packet for the FIN: see hv_ringbuffer_write() 254 * and hvs_shutdown(). 255 */ 256 if (writeable <= HVS_PKT_LEN(1) + HVS_PKT_LEN(0)) 257 return 0; 258 259 ret = writeable - HVS_PKT_LEN(1) - HVS_PKT_LEN(0); 260 261 return round_down(ret, 8); 262 } 263 264 static int hvs_send_data(struct vmbus_channel *chan, 265 struct hvs_send_buf *send_buf, size_t to_write) 266 { 267 send_buf->hdr.pkt_type = 1; 268 send_buf->hdr.data_size = to_write; 269 return vmbus_sendpacket(chan, &send_buf->hdr, 270 sizeof(send_buf->hdr) + to_write, 271 0, VM_PKT_DATA_INBAND, 0); 272 } 273 274 static void hvs_channel_cb(void *ctx) 275 { 276 struct sock *sk = (struct sock *)ctx; 277 struct vsock_sock *vsk = vsock_sk(sk); 278 struct hvsock *hvs = vsk->trans; 279 struct vmbus_channel *chan = hvs->chan; 280 281 if (hvs_channel_readable(chan)) 282 sk->sk_data_ready(sk); 283 284 if (hv_get_bytes_to_write(&chan->outbound) > 0) 285 sk->sk_write_space(sk); 286 } 287 288 static void hvs_do_close_lock_held(struct vsock_sock *vsk, 289 bool cancel_timeout) 290 { 291 struct sock *sk = sk_vsock(vsk); 292 293 sock_set_flag(sk, SOCK_DONE); 294 vsk->peer_shutdown = SHUTDOWN_MASK; 295 if (vsock_stream_has_data(vsk) <= 0) 296 sk->sk_state = TCP_CLOSING; 297 sk->sk_state_change(sk); 298 if (vsk->close_work_scheduled && 299 (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) { 300 vsk->close_work_scheduled = false; 301 vsock_remove_sock(vsk); 302 303 /* Release the reference taken while scheduling the timeout */ 304 sock_put(sk); 305 } 306 } 307 308 static void hvs_close_connection(struct vmbus_channel *chan) 309 { 310 struct sock *sk = get_per_channel_state(chan); 311 312 lock_sock(sk); 313 hvs_do_close_lock_held(vsock_sk(sk), true); 314 release_sock(sk); 315 316 /* Release the refcnt for the channel that's opened in 317 * hvs_open_connection(). 318 */ 319 sock_put(sk); 320 } 321 322 static void hvs_open_connection(struct vmbus_channel *chan) 323 { 324 guid_t *if_instance, *if_type; 325 unsigned char conn_from_host; 326 327 struct sockaddr_vm addr; 328 struct sock *sk, *new = NULL; 329 struct vsock_sock *vnew = NULL; 330 struct hvsock *hvs = NULL; 331 struct hvsock *hvs_new = NULL; 332 int rcvbuf; 333 int ret; 334 int sndbuf; 335 336 if_type = &chan->offermsg.offer.if_type; 337 if_instance = &chan->offermsg.offer.if_instance; 338 conn_from_host = chan->offermsg.offer.u.pipe.user_def[0]; 339 340 /* The host or the VM should only listen on a port in 341 * [0, MAX_LISTEN_PORT] 342 */ 343 if (!is_valid_srv_id(if_type) || 344 get_port_by_srv_id(if_type) > MAX_LISTEN_PORT) 345 return; 346 347 hvs_addr_init(&addr, conn_from_host ? if_type : if_instance); 348 sk = vsock_find_bound_socket(&addr); 349 if (!sk) 350 return; 351 352 lock_sock(sk); 353 if ((conn_from_host && sk->sk_state != TCP_LISTEN) || 354 (!conn_from_host && sk->sk_state != TCP_SYN_SENT)) 355 goto out; 356 357 if (conn_from_host) { 358 if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog) 359 goto out; 360 361 new = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL, 362 sk->sk_type, 0); 363 if (!new) 364 goto out; 365 366 new->sk_state = TCP_SYN_SENT; 367 vnew = vsock_sk(new); 368 hvs_new = vnew->trans; 369 hvs_new->chan = chan; 370 } else { 371 hvs = vsock_sk(sk)->trans; 372 hvs->chan = chan; 373 } 374 375 set_channel_read_mode(chan, HV_CALL_DIRECT); 376 377 /* Use the socket buffer sizes as hints for the VMBUS ring size. For 378 * server side sockets, 'sk' is the parent socket and thus, this will 379 * allow the child sockets to inherit the size from the parent. Keep 380 * the mins to the default value and align to page size as per VMBUS 381 * requirements. 382 * For the max, the socket core library will limit the socket buffer 383 * size that can be set by the user, but, since currently, the hv_sock 384 * VMBUS ring buffer is physically contiguous allocation, restrict it 385 * further. 386 * Older versions of hv_sock host side code cannot handle bigger VMBUS 387 * ring buffer size. Use the version number to limit the change to newer 388 * versions. 389 */ 390 if (vmbus_proto_version < VERSION_WIN10_V5) { 391 sndbuf = RINGBUFFER_HVS_SND_SIZE; 392 rcvbuf = RINGBUFFER_HVS_RCV_SIZE; 393 } else { 394 sndbuf = max_t(int, sk->sk_sndbuf, RINGBUFFER_HVS_SND_SIZE); 395 sndbuf = min_t(int, sndbuf, RINGBUFFER_HVS_MAX_SIZE); 396 sndbuf = ALIGN(sndbuf, PAGE_SIZE); 397 rcvbuf = max_t(int, sk->sk_rcvbuf, RINGBUFFER_HVS_RCV_SIZE); 398 rcvbuf = min_t(int, rcvbuf, RINGBUFFER_HVS_MAX_SIZE); 399 rcvbuf = ALIGN(rcvbuf, PAGE_SIZE); 400 } 401 402 ret = vmbus_open(chan, sndbuf, rcvbuf, NULL, 0, hvs_channel_cb, 403 conn_from_host ? new : sk); 404 if (ret != 0) { 405 if (conn_from_host) { 406 hvs_new->chan = NULL; 407 sock_put(new); 408 } else { 409 hvs->chan = NULL; 410 } 411 goto out; 412 } 413 414 set_per_channel_state(chan, conn_from_host ? new : sk); 415 416 /* This reference will be dropped by hvs_close_connection(). */ 417 sock_hold(conn_from_host ? new : sk); 418 vmbus_set_chn_rescind_callback(chan, hvs_close_connection); 419 420 /* Set the pending send size to max packet size to always get 421 * notifications from the host when there is enough writable space. 422 * The host is optimized to send notifications only when the pending 423 * size boundary is crossed, and not always. 424 */ 425 hvs_set_channel_pending_send_size(chan); 426 427 if (conn_from_host) { 428 new->sk_state = TCP_ESTABLISHED; 429 sk->sk_ack_backlog++; 430 431 hvs_addr_init(&vnew->local_addr, if_type); 432 hvs_remote_addr_init(&vnew->remote_addr, &vnew->local_addr); 433 434 hvs_new->vm_srv_id = *if_type; 435 hvs_new->host_srv_id = *if_instance; 436 437 vsock_insert_connected(vnew); 438 439 vsock_enqueue_accept(sk, new); 440 } else { 441 sk->sk_state = TCP_ESTABLISHED; 442 sk->sk_socket->state = SS_CONNECTED; 443 444 vsock_insert_connected(vsock_sk(sk)); 445 } 446 447 sk->sk_state_change(sk); 448 449 out: 450 /* Release refcnt obtained when we called vsock_find_bound_socket() */ 451 sock_put(sk); 452 453 release_sock(sk); 454 } 455 456 static u32 hvs_get_local_cid(void) 457 { 458 return VMADDR_CID_ANY; 459 } 460 461 static int hvs_sock_init(struct vsock_sock *vsk, struct vsock_sock *psk) 462 { 463 struct hvsock *hvs; 464 struct sock *sk = sk_vsock(vsk); 465 466 hvs = kzalloc(sizeof(*hvs), GFP_KERNEL); 467 if (!hvs) 468 return -ENOMEM; 469 470 vsk->trans = hvs; 471 hvs->vsk = vsk; 472 sk->sk_sndbuf = RINGBUFFER_HVS_SND_SIZE; 473 sk->sk_rcvbuf = RINGBUFFER_HVS_RCV_SIZE; 474 return 0; 475 } 476 477 static int hvs_connect(struct vsock_sock *vsk) 478 { 479 union hvs_service_id vm, host; 480 struct hvsock *h = vsk->trans; 481 482 vm.srv_id = srv_id_template; 483 vm.svm_port = vsk->local_addr.svm_port; 484 h->vm_srv_id = vm.srv_id; 485 486 host.srv_id = srv_id_template; 487 host.svm_port = vsk->remote_addr.svm_port; 488 h->host_srv_id = host.srv_id; 489 490 return vmbus_send_tl_connect_request(&h->vm_srv_id, &h->host_srv_id); 491 } 492 493 static void hvs_shutdown_lock_held(struct hvsock *hvs, int mode) 494 { 495 struct vmpipe_proto_header hdr; 496 497 if (hvs->fin_sent || !hvs->chan) 498 return; 499 500 /* It can't fail: see hvs_channel_writable_bytes(). */ 501 (void)hvs_send_data(hvs->chan, (struct hvs_send_buf *)&hdr, 0); 502 hvs->fin_sent = true; 503 } 504 505 static int hvs_shutdown(struct vsock_sock *vsk, int mode) 506 { 507 struct sock *sk = sk_vsock(vsk); 508 509 if (!(mode & SEND_SHUTDOWN)) 510 return 0; 511 512 lock_sock(sk); 513 hvs_shutdown_lock_held(vsk->trans, mode); 514 release_sock(sk); 515 return 0; 516 } 517 518 static void hvs_close_timeout(struct work_struct *work) 519 { 520 struct vsock_sock *vsk = 521 container_of(work, struct vsock_sock, close_work.work); 522 struct sock *sk = sk_vsock(vsk); 523 524 sock_hold(sk); 525 lock_sock(sk); 526 if (!sock_flag(sk, SOCK_DONE)) 527 hvs_do_close_lock_held(vsk, false); 528 529 vsk->close_work_scheduled = false; 530 release_sock(sk); 531 sock_put(sk); 532 } 533 534 /* Returns true, if it is safe to remove socket; false otherwise */ 535 static bool hvs_close_lock_held(struct vsock_sock *vsk) 536 { 537 struct sock *sk = sk_vsock(vsk); 538 539 if (!(sk->sk_state == TCP_ESTABLISHED || 540 sk->sk_state == TCP_CLOSING)) 541 return true; 542 543 if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK) 544 hvs_shutdown_lock_held(vsk->trans, SHUTDOWN_MASK); 545 546 if (sock_flag(sk, SOCK_DONE)) 547 return true; 548 549 /* This reference will be dropped by the delayed close routine */ 550 sock_hold(sk); 551 INIT_DELAYED_WORK(&vsk->close_work, hvs_close_timeout); 552 vsk->close_work_scheduled = true; 553 schedule_delayed_work(&vsk->close_work, HVS_CLOSE_TIMEOUT); 554 return false; 555 } 556 557 static void hvs_release(struct vsock_sock *vsk) 558 { 559 struct sock *sk = sk_vsock(vsk); 560 bool remove_sock; 561 562 lock_sock_nested(sk, SINGLE_DEPTH_NESTING); 563 remove_sock = hvs_close_lock_held(vsk); 564 release_sock(sk); 565 if (remove_sock) 566 vsock_remove_sock(vsk); 567 } 568 569 static void hvs_destruct(struct vsock_sock *vsk) 570 { 571 struct hvsock *hvs = vsk->trans; 572 struct vmbus_channel *chan = hvs->chan; 573 574 if (chan) 575 vmbus_hvsock_device_unregister(chan); 576 577 kfree(hvs); 578 } 579 580 static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr) 581 { 582 return -EOPNOTSUPP; 583 } 584 585 static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg, 586 size_t len, int flags) 587 { 588 return -EOPNOTSUPP; 589 } 590 591 static int hvs_dgram_enqueue(struct vsock_sock *vsk, 592 struct sockaddr_vm *remote, struct msghdr *msg, 593 size_t dgram_len) 594 { 595 return -EOPNOTSUPP; 596 } 597 598 static bool hvs_dgram_allow(u32 cid, u32 port) 599 { 600 return false; 601 } 602 603 static int hvs_update_recv_data(struct hvsock *hvs) 604 { 605 struct hvs_recv_buf *recv_buf; 606 u32 payload_len; 607 608 recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1); 609 payload_len = recv_buf->hdr.data_size; 610 611 if (payload_len > HVS_MTU_SIZE) 612 return -EIO; 613 614 if (payload_len == 0) 615 hvs->vsk->peer_shutdown |= SEND_SHUTDOWN; 616 617 hvs->recv_data_len = payload_len; 618 hvs->recv_data_off = 0; 619 620 return 0; 621 } 622 623 static ssize_t hvs_stream_dequeue(struct vsock_sock *vsk, struct msghdr *msg, 624 size_t len, int flags) 625 { 626 struct hvsock *hvs = vsk->trans; 627 bool need_refill = !hvs->recv_desc; 628 struct hvs_recv_buf *recv_buf; 629 u32 to_read; 630 int ret; 631 632 if (flags & MSG_PEEK) 633 return -EOPNOTSUPP; 634 635 if (need_refill) { 636 hvs->recv_desc = hv_pkt_iter_first(hvs->chan); 637 ret = hvs_update_recv_data(hvs); 638 if (ret) 639 return ret; 640 } 641 642 recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1); 643 to_read = min_t(u32, len, hvs->recv_data_len); 644 ret = memcpy_to_msg(msg, recv_buf->data + hvs->recv_data_off, to_read); 645 if (ret != 0) 646 return ret; 647 648 hvs->recv_data_len -= to_read; 649 if (hvs->recv_data_len == 0) { 650 hvs->recv_desc = hv_pkt_iter_next(hvs->chan, hvs->recv_desc); 651 if (hvs->recv_desc) { 652 ret = hvs_update_recv_data(hvs); 653 if (ret) 654 return ret; 655 } 656 } else { 657 hvs->recv_data_off += to_read; 658 } 659 660 return to_read; 661 } 662 663 static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg, 664 size_t len) 665 { 666 struct hvsock *hvs = vsk->trans; 667 struct vmbus_channel *chan = hvs->chan; 668 struct hvs_send_buf *send_buf; 669 ssize_t to_write, max_writable; 670 ssize_t ret = 0; 671 ssize_t bytes_written = 0; 672 673 BUILD_BUG_ON(sizeof(*send_buf) != PAGE_SIZE_4K); 674 675 send_buf = kmalloc(sizeof(*send_buf), GFP_KERNEL); 676 if (!send_buf) 677 return -ENOMEM; 678 679 /* Reader(s) could be draining data from the channel as we write. 680 * Maximize bandwidth, by iterating until the channel is found to be 681 * full. 682 */ 683 while (len) { 684 max_writable = hvs_channel_writable_bytes(chan); 685 if (!max_writable) 686 break; 687 to_write = min_t(ssize_t, len, max_writable); 688 to_write = min_t(ssize_t, to_write, HVS_SEND_BUF_SIZE); 689 /* memcpy_from_msg is safe for loop as it advances the offsets 690 * within the message iterator. 691 */ 692 ret = memcpy_from_msg(send_buf->data, msg, to_write); 693 if (ret < 0) 694 goto out; 695 696 ret = hvs_send_data(hvs->chan, send_buf, to_write); 697 if (ret < 0) 698 goto out; 699 700 bytes_written += to_write; 701 len -= to_write; 702 } 703 out: 704 /* If any data has been sent, return that */ 705 if (bytes_written) 706 ret = bytes_written; 707 kfree(send_buf); 708 return ret; 709 } 710 711 static s64 hvs_stream_has_data(struct vsock_sock *vsk) 712 { 713 struct hvsock *hvs = vsk->trans; 714 s64 ret; 715 716 if (hvs->recv_data_len > 0) 717 return 1; 718 719 switch (hvs_channel_readable_payload(hvs->chan)) { 720 case 1: 721 ret = 1; 722 break; 723 case 0: 724 vsk->peer_shutdown |= SEND_SHUTDOWN; 725 ret = 0; 726 break; 727 default: /* -1 */ 728 ret = 0; 729 break; 730 } 731 732 return ret; 733 } 734 735 static s64 hvs_stream_has_space(struct vsock_sock *vsk) 736 { 737 struct hvsock *hvs = vsk->trans; 738 739 return hvs_channel_writable_bytes(hvs->chan); 740 } 741 742 static u64 hvs_stream_rcvhiwat(struct vsock_sock *vsk) 743 { 744 return HVS_MTU_SIZE + 1; 745 } 746 747 static bool hvs_stream_is_active(struct vsock_sock *vsk) 748 { 749 struct hvsock *hvs = vsk->trans; 750 751 return hvs->chan != NULL; 752 } 753 754 static bool hvs_stream_allow(u32 cid, u32 port) 755 { 756 /* The host's port range [MIN_HOST_EPHEMERAL_PORT, 0xFFFFFFFF) is 757 * reserved as ephemeral ports, which are used as the host's ports 758 * when the host initiates connections. 759 * 760 * Perform this check in the guest so an immediate error is produced 761 * instead of a timeout. 762 */ 763 if (port > MAX_HOST_LISTEN_PORT) 764 return false; 765 766 if (cid == VMADDR_CID_HOST) 767 return true; 768 769 return false; 770 } 771 772 static 773 int hvs_notify_poll_in(struct vsock_sock *vsk, size_t target, bool *readable) 774 { 775 struct hvsock *hvs = vsk->trans; 776 777 *readable = hvs_channel_readable(hvs->chan); 778 return 0; 779 } 780 781 static 782 int hvs_notify_poll_out(struct vsock_sock *vsk, size_t target, bool *writable) 783 { 784 *writable = hvs_stream_has_space(vsk) > 0; 785 786 return 0; 787 } 788 789 static 790 int hvs_notify_recv_init(struct vsock_sock *vsk, size_t target, 791 struct vsock_transport_recv_notify_data *d) 792 { 793 return 0; 794 } 795 796 static 797 int hvs_notify_recv_pre_block(struct vsock_sock *vsk, size_t target, 798 struct vsock_transport_recv_notify_data *d) 799 { 800 return 0; 801 } 802 803 static 804 int hvs_notify_recv_pre_dequeue(struct vsock_sock *vsk, size_t target, 805 struct vsock_transport_recv_notify_data *d) 806 { 807 return 0; 808 } 809 810 static 811 int hvs_notify_recv_post_dequeue(struct vsock_sock *vsk, size_t target, 812 ssize_t copied, bool data_read, 813 struct vsock_transport_recv_notify_data *d) 814 { 815 return 0; 816 } 817 818 static 819 int hvs_notify_send_init(struct vsock_sock *vsk, 820 struct vsock_transport_send_notify_data *d) 821 { 822 return 0; 823 } 824 825 static 826 int hvs_notify_send_pre_block(struct vsock_sock *vsk, 827 struct vsock_transport_send_notify_data *d) 828 { 829 return 0; 830 } 831 832 static 833 int hvs_notify_send_pre_enqueue(struct vsock_sock *vsk, 834 struct vsock_transport_send_notify_data *d) 835 { 836 return 0; 837 } 838 839 static 840 int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written, 841 struct vsock_transport_send_notify_data *d) 842 { 843 return 0; 844 } 845 846 static void hvs_set_buffer_size(struct vsock_sock *vsk, u64 val) 847 { 848 /* Ignored. */ 849 } 850 851 static void hvs_set_min_buffer_size(struct vsock_sock *vsk, u64 val) 852 { 853 /* Ignored. */ 854 } 855 856 static void hvs_set_max_buffer_size(struct vsock_sock *vsk, u64 val) 857 { 858 /* Ignored. */ 859 } 860 861 static u64 hvs_get_buffer_size(struct vsock_sock *vsk) 862 { 863 return -ENOPROTOOPT; 864 } 865 866 static u64 hvs_get_min_buffer_size(struct vsock_sock *vsk) 867 { 868 return -ENOPROTOOPT; 869 } 870 871 static u64 hvs_get_max_buffer_size(struct vsock_sock *vsk) 872 { 873 return -ENOPROTOOPT; 874 } 875 876 static struct vsock_transport hvs_transport = { 877 .get_local_cid = hvs_get_local_cid, 878 879 .init = hvs_sock_init, 880 .destruct = hvs_destruct, 881 .release = hvs_release, 882 .connect = hvs_connect, 883 .shutdown = hvs_shutdown, 884 885 .dgram_bind = hvs_dgram_bind, 886 .dgram_dequeue = hvs_dgram_dequeue, 887 .dgram_enqueue = hvs_dgram_enqueue, 888 .dgram_allow = hvs_dgram_allow, 889 890 .stream_dequeue = hvs_stream_dequeue, 891 .stream_enqueue = hvs_stream_enqueue, 892 .stream_has_data = hvs_stream_has_data, 893 .stream_has_space = hvs_stream_has_space, 894 .stream_rcvhiwat = hvs_stream_rcvhiwat, 895 .stream_is_active = hvs_stream_is_active, 896 .stream_allow = hvs_stream_allow, 897 898 .notify_poll_in = hvs_notify_poll_in, 899 .notify_poll_out = hvs_notify_poll_out, 900 .notify_recv_init = hvs_notify_recv_init, 901 .notify_recv_pre_block = hvs_notify_recv_pre_block, 902 .notify_recv_pre_dequeue = hvs_notify_recv_pre_dequeue, 903 .notify_recv_post_dequeue = hvs_notify_recv_post_dequeue, 904 .notify_send_init = hvs_notify_send_init, 905 .notify_send_pre_block = hvs_notify_send_pre_block, 906 .notify_send_pre_enqueue = hvs_notify_send_pre_enqueue, 907 .notify_send_post_enqueue = hvs_notify_send_post_enqueue, 908 909 .set_buffer_size = hvs_set_buffer_size, 910 .set_min_buffer_size = hvs_set_min_buffer_size, 911 .set_max_buffer_size = hvs_set_max_buffer_size, 912 .get_buffer_size = hvs_get_buffer_size, 913 .get_min_buffer_size = hvs_get_min_buffer_size, 914 .get_max_buffer_size = hvs_get_max_buffer_size, 915 }; 916 917 static int hvs_probe(struct hv_device *hdev, 918 const struct hv_vmbus_device_id *dev_id) 919 { 920 struct vmbus_channel *chan = hdev->channel; 921 922 hvs_open_connection(chan); 923 924 /* Always return success to suppress the unnecessary error message 925 * in vmbus_probe(): on error the host will rescind the device in 926 * 30 seconds and we can do cleanup at that time in 927 * vmbus_onoffer_rescind(). 928 */ 929 return 0; 930 } 931 932 static int hvs_remove(struct hv_device *hdev) 933 { 934 struct vmbus_channel *chan = hdev->channel; 935 936 vmbus_close(chan); 937 938 return 0; 939 } 940 941 /* This isn't really used. See vmbus_match() and vmbus_probe() */ 942 static const struct hv_vmbus_device_id id_table[] = { 943 {}, 944 }; 945 946 static struct hv_driver hvs_drv = { 947 .name = "hv_sock", 948 .hvsock = true, 949 .id_table = id_table, 950 .probe = hvs_probe, 951 .remove = hvs_remove, 952 }; 953 954 static int __init hvs_init(void) 955 { 956 int ret; 957 958 if (vmbus_proto_version < VERSION_WIN10) 959 return -ENODEV; 960 961 ret = vmbus_driver_register(&hvs_drv); 962 if (ret != 0) 963 return ret; 964 965 ret = vsock_core_init(&hvs_transport); 966 if (ret) { 967 vmbus_driver_unregister(&hvs_drv); 968 return ret; 969 } 970 971 return 0; 972 } 973 974 static void __exit hvs_exit(void) 975 { 976 vsock_core_exit(); 977 vmbus_driver_unregister(&hvs_drv); 978 } 979 980 module_init(hvs_init); 981 module_exit(hvs_exit); 982 983 MODULE_DESCRIPTION("Hyper-V Sockets"); 984 MODULE_VERSION("1.0.0"); 985 MODULE_LICENSE("GPL"); 986 MODULE_ALIAS_NETPROTO(PF_VSOCK); 987