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 #include <asm/hyperv-tlfs.h> 17 18 /* Older (VMBUS version 'VERSION_WIN10' or before) Windows hosts have some 19 * stricter requirements on the hv_sock ring buffer size of six 4K pages. 20 * hyperv-tlfs defines HV_HYP_PAGE_SIZE as 4K. Newer hosts don't have this 21 * limitation; but, keep the defaults the same for compat. 22 */ 23 #define RINGBUFFER_HVS_RCV_SIZE (HV_HYP_PAGE_SIZE * 6) 24 #define RINGBUFFER_HVS_SND_SIZE (HV_HYP_PAGE_SIZE * 6) 25 #define RINGBUFFER_HVS_MAX_SIZE (HV_HYP_PAGE_SIZE * 64) 26 27 /* The MTU is 16KB per the host side's design */ 28 #define HVS_MTU_SIZE (1024 * 16) 29 30 /* How long to wait for graceful shutdown of a connection */ 31 #define HVS_CLOSE_TIMEOUT (8 * HZ) 32 33 struct vmpipe_proto_header { 34 u32 pkt_type; 35 u32 data_size; 36 }; 37 38 /* For recv, we use the VMBus in-place packet iterator APIs to directly copy 39 * data from the ringbuffer into the userspace buffer. 40 */ 41 struct hvs_recv_buf { 42 /* The header before the payload data */ 43 struct vmpipe_proto_header hdr; 44 45 /* The payload */ 46 u8 data[HVS_MTU_SIZE]; 47 }; 48 49 /* We can send up to HVS_MTU_SIZE bytes of payload to the host, but let's use 50 * a smaller size, i.e. HVS_SEND_BUF_SIZE, to maximize concurrency between the 51 * guest and the host processing as one VMBUS packet is the smallest processing 52 * unit. 53 * 54 * Note: the buffer can be eliminated in the future when we add new VMBus 55 * ringbuffer APIs that allow us to directly copy data from userspace buffer 56 * to VMBus ringbuffer. 57 */ 58 #define HVS_SEND_BUF_SIZE \ 59 (HV_HYP_PAGE_SIZE - sizeof(struct vmpipe_proto_header)) 60 61 struct hvs_send_buf { 62 /* The header before the payload data */ 63 struct vmpipe_proto_header hdr; 64 65 /* The payload */ 66 u8 data[HVS_SEND_BUF_SIZE]; 67 }; 68 69 #define HVS_HEADER_LEN (sizeof(struct vmpacket_descriptor) + \ 70 sizeof(struct vmpipe_proto_header)) 71 72 /* See 'prev_indices' in hv_ringbuffer_read(), hv_ringbuffer_write(), and 73 * __hv_pkt_iter_next(). 74 */ 75 #define VMBUS_PKT_TRAILER_SIZE (sizeof(u64)) 76 77 #define HVS_PKT_LEN(payload_len) (HVS_HEADER_LEN + \ 78 ALIGN((payload_len), 8) + \ 79 VMBUS_PKT_TRAILER_SIZE) 80 81 union hvs_service_id { 82 guid_t srv_id; 83 84 struct { 85 unsigned int svm_port; 86 unsigned char b[sizeof(guid_t) - sizeof(unsigned int)]; 87 }; 88 }; 89 90 /* Per-socket state (accessed via vsk->trans) */ 91 struct hvsock { 92 struct vsock_sock *vsk; 93 94 guid_t vm_srv_id; 95 guid_t host_srv_id; 96 97 struct vmbus_channel *chan; 98 struct vmpacket_descriptor *recv_desc; 99 100 /* The length of the payload not delivered to userland yet */ 101 u32 recv_data_len; 102 /* The offset of the payload */ 103 u32 recv_data_off; 104 105 /* Have we sent the zero-length packet (FIN)? */ 106 bool fin_sent; 107 }; 108 109 /* In the VM, we support Hyper-V Sockets with AF_VSOCK, and the endpoint is 110 * <cid, port> (see struct sockaddr_vm). Note: cid is not really used here: 111 * when we write apps to connect to the host, we can only use VMADDR_CID_ANY 112 * or VMADDR_CID_HOST (both are equivalent) as the remote cid, and when we 113 * write apps to bind() & listen() in the VM, we can only use VMADDR_CID_ANY 114 * as the local cid. 115 * 116 * On the host, Hyper-V Sockets are supported by Winsock AF_HYPERV: 117 * https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user- 118 * guide/make-integration-service, and the endpoint is <VmID, ServiceId> with 119 * the below sockaddr: 120 * 121 * struct SOCKADDR_HV 122 * { 123 * ADDRESS_FAMILY Family; 124 * USHORT Reserved; 125 * GUID VmId; 126 * GUID ServiceId; 127 * }; 128 * Note: VmID is not used by Linux VM and actually it isn't transmitted via 129 * VMBus, because here it's obvious the host and the VM can easily identify 130 * each other. Though the VmID is useful on the host, especially in the case 131 * of Windows container, Linux VM doesn't need it at all. 132 * 133 * To make use of the AF_VSOCK infrastructure in Linux VM, we have to limit 134 * the available GUID space of SOCKADDR_HV so that we can create a mapping 135 * between AF_VSOCK port and SOCKADDR_HV Service GUID. The rule of writing 136 * Hyper-V Sockets apps on the host and in Linux VM is: 137 * 138 **************************************************************************** 139 * The only valid Service GUIDs, from the perspectives of both the host and * 140 * Linux VM, that can be connected by the other end, must conform to this * 141 * format: <port>-facb-11e6-bd58-64006a7986d3. * 142 **************************************************************************** 143 * 144 * When we write apps on the host to connect(), the GUID ServiceID is used. 145 * When we write apps in Linux VM to connect(), we only need to specify the 146 * port and the driver will form the GUID and use that to request the host. 147 * 148 */ 149 150 /* 00000000-facb-11e6-bd58-64006a7986d3 */ 151 static const guid_t srv_id_template = 152 GUID_INIT(0x00000000, 0xfacb, 0x11e6, 0xbd, 0x58, 153 0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3); 154 155 static bool hvs_check_transport(struct vsock_sock *vsk); 156 157 static bool is_valid_srv_id(const guid_t *id) 158 { 159 return !memcmp(&id->b[4], &srv_id_template.b[4], sizeof(guid_t) - 4); 160 } 161 162 static unsigned int get_port_by_srv_id(const guid_t *svr_id) 163 { 164 return *((unsigned int *)svr_id); 165 } 166 167 static void hvs_addr_init(struct sockaddr_vm *addr, const guid_t *svr_id) 168 { 169 unsigned int port = get_port_by_srv_id(svr_id); 170 171 vsock_addr_init(addr, VMADDR_CID_ANY, port); 172 } 173 174 static void hvs_set_channel_pending_send_size(struct vmbus_channel *chan) 175 { 176 set_channel_pending_send_size(chan, 177 HVS_PKT_LEN(HVS_SEND_BUF_SIZE)); 178 179 virt_mb(); 180 } 181 182 static bool hvs_channel_readable(struct vmbus_channel *chan) 183 { 184 u32 readable = hv_get_bytes_to_read(&chan->inbound); 185 186 /* 0-size payload means FIN */ 187 return readable >= HVS_PKT_LEN(0); 188 } 189 190 static int hvs_channel_readable_payload(struct vmbus_channel *chan) 191 { 192 u32 readable = hv_get_bytes_to_read(&chan->inbound); 193 194 if (readable > HVS_PKT_LEN(0)) { 195 /* At least we have 1 byte to read. We don't need to return 196 * the exact readable bytes: see vsock_stream_recvmsg() -> 197 * vsock_stream_has_data(). 198 */ 199 return 1; 200 } 201 202 if (readable == HVS_PKT_LEN(0)) { 203 /* 0-size payload means FIN */ 204 return 0; 205 } 206 207 /* No payload or FIN */ 208 return -1; 209 } 210 211 static size_t hvs_channel_writable_bytes(struct vmbus_channel *chan) 212 { 213 u32 writeable = hv_get_bytes_to_write(&chan->outbound); 214 size_t ret; 215 216 /* The ringbuffer mustn't be 100% full, and we should reserve a 217 * zero-length-payload packet for the FIN: see hv_ringbuffer_write() 218 * and hvs_shutdown(). 219 */ 220 if (writeable <= HVS_PKT_LEN(1) + HVS_PKT_LEN(0)) 221 return 0; 222 223 ret = writeable - HVS_PKT_LEN(1) - HVS_PKT_LEN(0); 224 225 return round_down(ret, 8); 226 } 227 228 static int __hvs_send_data(struct vmbus_channel *chan, 229 struct vmpipe_proto_header *hdr, 230 size_t to_write) 231 { 232 hdr->pkt_type = 1; 233 hdr->data_size = to_write; 234 return vmbus_sendpacket(chan, hdr, sizeof(*hdr) + to_write, 235 0, VM_PKT_DATA_INBAND, 0); 236 } 237 238 static int hvs_send_data(struct vmbus_channel *chan, 239 struct hvs_send_buf *send_buf, size_t to_write) 240 { 241 return __hvs_send_data(chan, &send_buf->hdr, to_write); 242 } 243 244 static void hvs_channel_cb(void *ctx) 245 { 246 struct sock *sk = (struct sock *)ctx; 247 struct vsock_sock *vsk = vsock_sk(sk); 248 struct hvsock *hvs = vsk->trans; 249 struct vmbus_channel *chan = hvs->chan; 250 251 if (hvs_channel_readable(chan)) 252 sk->sk_data_ready(sk); 253 254 if (hv_get_bytes_to_write(&chan->outbound) > 0) 255 sk->sk_write_space(sk); 256 } 257 258 static void hvs_do_close_lock_held(struct vsock_sock *vsk, 259 bool cancel_timeout) 260 { 261 struct sock *sk = sk_vsock(vsk); 262 263 sock_set_flag(sk, SOCK_DONE); 264 vsk->peer_shutdown = SHUTDOWN_MASK; 265 if (vsock_stream_has_data(vsk) <= 0) 266 sk->sk_state = TCP_CLOSING; 267 sk->sk_state_change(sk); 268 if (vsk->close_work_scheduled && 269 (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) { 270 vsk->close_work_scheduled = false; 271 vsock_remove_sock(vsk); 272 273 /* Release the reference taken while scheduling the timeout */ 274 sock_put(sk); 275 } 276 } 277 278 static void hvs_close_connection(struct vmbus_channel *chan) 279 { 280 struct sock *sk = get_per_channel_state(chan); 281 282 lock_sock(sk); 283 hvs_do_close_lock_held(vsock_sk(sk), true); 284 release_sock(sk); 285 286 /* Release the refcnt for the channel that's opened in 287 * hvs_open_connection(). 288 */ 289 sock_put(sk); 290 } 291 292 static void hvs_open_connection(struct vmbus_channel *chan) 293 { 294 guid_t *if_instance, *if_type; 295 unsigned char conn_from_host; 296 297 struct sockaddr_vm addr; 298 struct sock *sk, *new = NULL; 299 struct vsock_sock *vnew = NULL; 300 struct hvsock *hvs = NULL; 301 struct hvsock *hvs_new = NULL; 302 int rcvbuf; 303 int ret; 304 int sndbuf; 305 306 if_type = &chan->offermsg.offer.if_type; 307 if_instance = &chan->offermsg.offer.if_instance; 308 conn_from_host = chan->offermsg.offer.u.pipe.user_def[0]; 309 if (!is_valid_srv_id(if_type)) 310 return; 311 312 hvs_addr_init(&addr, conn_from_host ? if_type : if_instance); 313 sk = vsock_find_bound_socket(&addr); 314 if (!sk) 315 return; 316 317 lock_sock(sk); 318 if ((conn_from_host && sk->sk_state != TCP_LISTEN) || 319 (!conn_from_host && sk->sk_state != TCP_SYN_SENT)) 320 goto out; 321 322 if (conn_from_host) { 323 if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog) 324 goto out; 325 326 new = vsock_create_connected(sk); 327 if (!new) 328 goto out; 329 330 new->sk_state = TCP_SYN_SENT; 331 vnew = vsock_sk(new); 332 333 hvs_addr_init(&vnew->local_addr, if_type); 334 335 /* Remote peer is always the host */ 336 vsock_addr_init(&vnew->remote_addr, 337 VMADDR_CID_HOST, VMADDR_PORT_ANY); 338 vnew->remote_addr.svm_port = get_port_by_srv_id(if_instance); 339 ret = vsock_assign_transport(vnew, vsock_sk(sk)); 340 /* Transport assigned (looking at remote_addr) must be the 341 * same where we received the request. 342 */ 343 if (ret || !hvs_check_transport(vnew)) { 344 sock_put(new); 345 goto out; 346 } 347 hvs_new = vnew->trans; 348 hvs_new->chan = chan; 349 } else { 350 hvs = vsock_sk(sk)->trans; 351 hvs->chan = chan; 352 } 353 354 set_channel_read_mode(chan, HV_CALL_DIRECT); 355 356 /* Use the socket buffer sizes as hints for the VMBUS ring size. For 357 * server side sockets, 'sk' is the parent socket and thus, this will 358 * allow the child sockets to inherit the size from the parent. Keep 359 * the mins to the default value and align to page size as per VMBUS 360 * requirements. 361 * For the max, the socket core library will limit the socket buffer 362 * size that can be set by the user, but, since currently, the hv_sock 363 * VMBUS ring buffer is physically contiguous allocation, restrict it 364 * further. 365 * Older versions of hv_sock host side code cannot handle bigger VMBUS 366 * ring buffer size. Use the version number to limit the change to newer 367 * versions. 368 */ 369 if (vmbus_proto_version < VERSION_WIN10_V5) { 370 sndbuf = RINGBUFFER_HVS_SND_SIZE; 371 rcvbuf = RINGBUFFER_HVS_RCV_SIZE; 372 } else { 373 sndbuf = max_t(int, sk->sk_sndbuf, RINGBUFFER_HVS_SND_SIZE); 374 sndbuf = min_t(int, sndbuf, RINGBUFFER_HVS_MAX_SIZE); 375 sndbuf = ALIGN(sndbuf, HV_HYP_PAGE_SIZE); 376 rcvbuf = max_t(int, sk->sk_rcvbuf, RINGBUFFER_HVS_RCV_SIZE); 377 rcvbuf = min_t(int, rcvbuf, RINGBUFFER_HVS_MAX_SIZE); 378 rcvbuf = ALIGN(rcvbuf, HV_HYP_PAGE_SIZE); 379 } 380 381 ret = vmbus_open(chan, sndbuf, rcvbuf, NULL, 0, hvs_channel_cb, 382 conn_from_host ? new : sk); 383 if (ret != 0) { 384 if (conn_from_host) { 385 hvs_new->chan = NULL; 386 sock_put(new); 387 } else { 388 hvs->chan = NULL; 389 } 390 goto out; 391 } 392 393 set_per_channel_state(chan, conn_from_host ? new : sk); 394 395 /* This reference will be dropped by hvs_close_connection(). */ 396 sock_hold(conn_from_host ? new : sk); 397 vmbus_set_chn_rescind_callback(chan, hvs_close_connection); 398 399 /* Set the pending send size to max packet size to always get 400 * notifications from the host when there is enough writable space. 401 * The host is optimized to send notifications only when the pending 402 * size boundary is crossed, and not always. 403 */ 404 hvs_set_channel_pending_send_size(chan); 405 406 if (conn_from_host) { 407 new->sk_state = TCP_ESTABLISHED; 408 sk_acceptq_added(sk); 409 410 hvs_new->vm_srv_id = *if_type; 411 hvs_new->host_srv_id = *if_instance; 412 413 vsock_insert_connected(vnew); 414 415 vsock_enqueue_accept(sk, new); 416 } else { 417 sk->sk_state = TCP_ESTABLISHED; 418 sk->sk_socket->state = SS_CONNECTED; 419 420 vsock_insert_connected(vsock_sk(sk)); 421 } 422 423 sk->sk_state_change(sk); 424 425 out: 426 /* Release refcnt obtained when we called vsock_find_bound_socket() */ 427 sock_put(sk); 428 429 release_sock(sk); 430 } 431 432 static u32 hvs_get_local_cid(void) 433 { 434 return VMADDR_CID_ANY; 435 } 436 437 static int hvs_sock_init(struct vsock_sock *vsk, struct vsock_sock *psk) 438 { 439 struct hvsock *hvs; 440 struct sock *sk = sk_vsock(vsk); 441 442 hvs = kzalloc(sizeof(*hvs), GFP_KERNEL); 443 if (!hvs) 444 return -ENOMEM; 445 446 vsk->trans = hvs; 447 hvs->vsk = vsk; 448 sk->sk_sndbuf = RINGBUFFER_HVS_SND_SIZE; 449 sk->sk_rcvbuf = RINGBUFFER_HVS_RCV_SIZE; 450 return 0; 451 } 452 453 static int hvs_connect(struct vsock_sock *vsk) 454 { 455 union hvs_service_id vm, host; 456 struct hvsock *h = vsk->trans; 457 458 vm.srv_id = srv_id_template; 459 vm.svm_port = vsk->local_addr.svm_port; 460 h->vm_srv_id = vm.srv_id; 461 462 host.srv_id = srv_id_template; 463 host.svm_port = vsk->remote_addr.svm_port; 464 h->host_srv_id = host.srv_id; 465 466 return vmbus_send_tl_connect_request(&h->vm_srv_id, &h->host_srv_id); 467 } 468 469 static void hvs_shutdown_lock_held(struct hvsock *hvs, int mode) 470 { 471 struct vmpipe_proto_header hdr; 472 473 if (hvs->fin_sent || !hvs->chan) 474 return; 475 476 /* It can't fail: see hvs_channel_writable_bytes(). */ 477 (void)__hvs_send_data(hvs->chan, &hdr, 0); 478 hvs->fin_sent = true; 479 } 480 481 static int hvs_shutdown(struct vsock_sock *vsk, int mode) 482 { 483 if (!(mode & SEND_SHUTDOWN)) 484 return 0; 485 486 hvs_shutdown_lock_held(vsk->trans, mode); 487 return 0; 488 } 489 490 static void hvs_close_timeout(struct work_struct *work) 491 { 492 struct vsock_sock *vsk = 493 container_of(work, struct vsock_sock, close_work.work); 494 struct sock *sk = sk_vsock(vsk); 495 496 sock_hold(sk); 497 lock_sock(sk); 498 if (!sock_flag(sk, SOCK_DONE)) 499 hvs_do_close_lock_held(vsk, false); 500 501 vsk->close_work_scheduled = false; 502 release_sock(sk); 503 sock_put(sk); 504 } 505 506 /* Returns true, if it is safe to remove socket; false otherwise */ 507 static bool hvs_close_lock_held(struct vsock_sock *vsk) 508 { 509 struct sock *sk = sk_vsock(vsk); 510 511 if (!(sk->sk_state == TCP_ESTABLISHED || 512 sk->sk_state == TCP_CLOSING)) 513 return true; 514 515 if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK) 516 hvs_shutdown_lock_held(vsk->trans, SHUTDOWN_MASK); 517 518 if (sock_flag(sk, SOCK_DONE)) 519 return true; 520 521 /* This reference will be dropped by the delayed close routine */ 522 sock_hold(sk); 523 INIT_DELAYED_WORK(&vsk->close_work, hvs_close_timeout); 524 vsk->close_work_scheduled = true; 525 schedule_delayed_work(&vsk->close_work, HVS_CLOSE_TIMEOUT); 526 return false; 527 } 528 529 static void hvs_release(struct vsock_sock *vsk) 530 { 531 bool remove_sock; 532 533 remove_sock = hvs_close_lock_held(vsk); 534 if (remove_sock) 535 vsock_remove_sock(vsk); 536 } 537 538 static void hvs_destruct(struct vsock_sock *vsk) 539 { 540 struct hvsock *hvs = vsk->trans; 541 struct vmbus_channel *chan = hvs->chan; 542 543 if (chan) 544 vmbus_hvsock_device_unregister(chan); 545 546 kfree(hvs); 547 } 548 549 static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr) 550 { 551 return -EOPNOTSUPP; 552 } 553 554 static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg, 555 size_t len, int flags) 556 { 557 return -EOPNOTSUPP; 558 } 559 560 static int hvs_dgram_enqueue(struct vsock_sock *vsk, 561 struct sockaddr_vm *remote, struct msghdr *msg, 562 size_t dgram_len) 563 { 564 return -EOPNOTSUPP; 565 } 566 567 static bool hvs_dgram_allow(u32 cid, u32 port) 568 { 569 return false; 570 } 571 572 static int hvs_update_recv_data(struct hvsock *hvs) 573 { 574 struct hvs_recv_buf *recv_buf; 575 u32 payload_len; 576 577 recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1); 578 payload_len = recv_buf->hdr.data_size; 579 580 if (payload_len > HVS_MTU_SIZE) 581 return -EIO; 582 583 if (payload_len == 0) 584 hvs->vsk->peer_shutdown |= SEND_SHUTDOWN; 585 586 hvs->recv_data_len = payload_len; 587 hvs->recv_data_off = 0; 588 589 return 0; 590 } 591 592 static ssize_t hvs_stream_dequeue(struct vsock_sock *vsk, struct msghdr *msg, 593 size_t len, int flags) 594 { 595 struct hvsock *hvs = vsk->trans; 596 bool need_refill = !hvs->recv_desc; 597 struct hvs_recv_buf *recv_buf; 598 u32 to_read; 599 int ret; 600 601 if (flags & MSG_PEEK) 602 return -EOPNOTSUPP; 603 604 if (need_refill) { 605 hvs->recv_desc = hv_pkt_iter_first_raw(hvs->chan); 606 ret = hvs_update_recv_data(hvs); 607 if (ret) 608 return ret; 609 } 610 611 recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1); 612 to_read = min_t(u32, len, hvs->recv_data_len); 613 ret = memcpy_to_msg(msg, recv_buf->data + hvs->recv_data_off, to_read); 614 if (ret != 0) 615 return ret; 616 617 hvs->recv_data_len -= to_read; 618 if (hvs->recv_data_len == 0) { 619 hvs->recv_desc = hv_pkt_iter_next_raw(hvs->chan, hvs->recv_desc); 620 if (hvs->recv_desc) { 621 ret = hvs_update_recv_data(hvs); 622 if (ret) 623 return ret; 624 } 625 } else { 626 hvs->recv_data_off += to_read; 627 } 628 629 return to_read; 630 } 631 632 static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg, 633 size_t len) 634 { 635 struct hvsock *hvs = vsk->trans; 636 struct vmbus_channel *chan = hvs->chan; 637 struct hvs_send_buf *send_buf; 638 ssize_t to_write, max_writable; 639 ssize_t ret = 0; 640 ssize_t bytes_written = 0; 641 642 BUILD_BUG_ON(sizeof(*send_buf) != HV_HYP_PAGE_SIZE); 643 644 send_buf = kmalloc(sizeof(*send_buf), GFP_KERNEL); 645 if (!send_buf) 646 return -ENOMEM; 647 648 /* Reader(s) could be draining data from the channel as we write. 649 * Maximize bandwidth, by iterating until the channel is found to be 650 * full. 651 */ 652 while (len) { 653 max_writable = hvs_channel_writable_bytes(chan); 654 if (!max_writable) 655 break; 656 to_write = min_t(ssize_t, len, max_writable); 657 to_write = min_t(ssize_t, to_write, HVS_SEND_BUF_SIZE); 658 /* memcpy_from_msg is safe for loop as it advances the offsets 659 * within the message iterator. 660 */ 661 ret = memcpy_from_msg(send_buf->data, msg, to_write); 662 if (ret < 0) 663 goto out; 664 665 ret = hvs_send_data(hvs->chan, send_buf, to_write); 666 if (ret < 0) 667 goto out; 668 669 bytes_written += to_write; 670 len -= to_write; 671 } 672 out: 673 /* If any data has been sent, return that */ 674 if (bytes_written) 675 ret = bytes_written; 676 kfree(send_buf); 677 return ret; 678 } 679 680 static s64 hvs_stream_has_data(struct vsock_sock *vsk) 681 { 682 struct hvsock *hvs = vsk->trans; 683 s64 ret; 684 685 if (hvs->recv_data_len > 0) 686 return 1; 687 688 switch (hvs_channel_readable_payload(hvs->chan)) { 689 case 1: 690 ret = 1; 691 break; 692 case 0: 693 vsk->peer_shutdown |= SEND_SHUTDOWN; 694 ret = 0; 695 break; 696 default: /* -1 */ 697 ret = 0; 698 break; 699 } 700 701 return ret; 702 } 703 704 static s64 hvs_stream_has_space(struct vsock_sock *vsk) 705 { 706 struct hvsock *hvs = vsk->trans; 707 708 return hvs_channel_writable_bytes(hvs->chan); 709 } 710 711 static u64 hvs_stream_rcvhiwat(struct vsock_sock *vsk) 712 { 713 return HVS_MTU_SIZE + 1; 714 } 715 716 static bool hvs_stream_is_active(struct vsock_sock *vsk) 717 { 718 struct hvsock *hvs = vsk->trans; 719 720 return hvs->chan != NULL; 721 } 722 723 static bool hvs_stream_allow(u32 cid, u32 port) 724 { 725 if (cid == VMADDR_CID_HOST) 726 return true; 727 728 return false; 729 } 730 731 static 732 int hvs_notify_poll_in(struct vsock_sock *vsk, size_t target, bool *readable) 733 { 734 struct hvsock *hvs = vsk->trans; 735 736 *readable = hvs_channel_readable(hvs->chan); 737 return 0; 738 } 739 740 static 741 int hvs_notify_poll_out(struct vsock_sock *vsk, size_t target, bool *writable) 742 { 743 *writable = hvs_stream_has_space(vsk) > 0; 744 745 return 0; 746 } 747 748 static 749 int hvs_notify_recv_init(struct vsock_sock *vsk, size_t target, 750 struct vsock_transport_recv_notify_data *d) 751 { 752 return 0; 753 } 754 755 static 756 int hvs_notify_recv_pre_block(struct vsock_sock *vsk, size_t target, 757 struct vsock_transport_recv_notify_data *d) 758 { 759 return 0; 760 } 761 762 static 763 int hvs_notify_recv_pre_dequeue(struct vsock_sock *vsk, size_t target, 764 struct vsock_transport_recv_notify_data *d) 765 { 766 return 0; 767 } 768 769 static 770 int hvs_notify_recv_post_dequeue(struct vsock_sock *vsk, size_t target, 771 ssize_t copied, bool data_read, 772 struct vsock_transport_recv_notify_data *d) 773 { 774 return 0; 775 } 776 777 static 778 int hvs_notify_send_init(struct vsock_sock *vsk, 779 struct vsock_transport_send_notify_data *d) 780 { 781 return 0; 782 } 783 784 static 785 int hvs_notify_send_pre_block(struct vsock_sock *vsk, 786 struct vsock_transport_send_notify_data *d) 787 { 788 return 0; 789 } 790 791 static 792 int hvs_notify_send_pre_enqueue(struct vsock_sock *vsk, 793 struct vsock_transport_send_notify_data *d) 794 { 795 return 0; 796 } 797 798 static 799 int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written, 800 struct vsock_transport_send_notify_data *d) 801 { 802 return 0; 803 } 804 805 static struct vsock_transport hvs_transport = { 806 .module = THIS_MODULE, 807 808 .get_local_cid = hvs_get_local_cid, 809 810 .init = hvs_sock_init, 811 .destruct = hvs_destruct, 812 .release = hvs_release, 813 .connect = hvs_connect, 814 .shutdown = hvs_shutdown, 815 816 .dgram_bind = hvs_dgram_bind, 817 .dgram_dequeue = hvs_dgram_dequeue, 818 .dgram_enqueue = hvs_dgram_enqueue, 819 .dgram_allow = hvs_dgram_allow, 820 821 .stream_dequeue = hvs_stream_dequeue, 822 .stream_enqueue = hvs_stream_enqueue, 823 .stream_has_data = hvs_stream_has_data, 824 .stream_has_space = hvs_stream_has_space, 825 .stream_rcvhiwat = hvs_stream_rcvhiwat, 826 .stream_is_active = hvs_stream_is_active, 827 .stream_allow = hvs_stream_allow, 828 829 .notify_poll_in = hvs_notify_poll_in, 830 .notify_poll_out = hvs_notify_poll_out, 831 .notify_recv_init = hvs_notify_recv_init, 832 .notify_recv_pre_block = hvs_notify_recv_pre_block, 833 .notify_recv_pre_dequeue = hvs_notify_recv_pre_dequeue, 834 .notify_recv_post_dequeue = hvs_notify_recv_post_dequeue, 835 .notify_send_init = hvs_notify_send_init, 836 .notify_send_pre_block = hvs_notify_send_pre_block, 837 .notify_send_pre_enqueue = hvs_notify_send_pre_enqueue, 838 .notify_send_post_enqueue = hvs_notify_send_post_enqueue, 839 840 }; 841 842 static bool hvs_check_transport(struct vsock_sock *vsk) 843 { 844 return vsk->transport == &hvs_transport; 845 } 846 847 static int hvs_probe(struct hv_device *hdev, 848 const struct hv_vmbus_device_id *dev_id) 849 { 850 struct vmbus_channel *chan = hdev->channel; 851 852 hvs_open_connection(chan); 853 854 /* Always return success to suppress the unnecessary error message 855 * in vmbus_probe(): on error the host will rescind the device in 856 * 30 seconds and we can do cleanup at that time in 857 * vmbus_onoffer_rescind(). 858 */ 859 return 0; 860 } 861 862 static int hvs_remove(struct hv_device *hdev) 863 { 864 struct vmbus_channel *chan = hdev->channel; 865 866 vmbus_close(chan); 867 868 return 0; 869 } 870 871 /* hv_sock connections can not persist across hibernation, and all the hv_sock 872 * channels are forced to be rescinded before hibernation: see 873 * vmbus_bus_suspend(). Here the dummy hvs_suspend() and hvs_resume() 874 * are only needed because hibernation requires that every vmbus device's 875 * driver should have a .suspend and .resume callback: see vmbus_suspend(). 876 */ 877 static int hvs_suspend(struct hv_device *hv_dev) 878 { 879 /* Dummy */ 880 return 0; 881 } 882 883 static int hvs_resume(struct hv_device *dev) 884 { 885 /* Dummy */ 886 return 0; 887 } 888 889 /* This isn't really used. See vmbus_match() and vmbus_probe() */ 890 static const struct hv_vmbus_device_id id_table[] = { 891 {}, 892 }; 893 894 static struct hv_driver hvs_drv = { 895 .name = "hv_sock", 896 .hvsock = true, 897 .id_table = id_table, 898 .probe = hvs_probe, 899 .remove = hvs_remove, 900 .suspend = hvs_suspend, 901 .resume = hvs_resume, 902 }; 903 904 static int __init hvs_init(void) 905 { 906 int ret; 907 908 if (vmbus_proto_version < VERSION_WIN10) 909 return -ENODEV; 910 911 ret = vmbus_driver_register(&hvs_drv); 912 if (ret != 0) 913 return ret; 914 915 ret = vsock_core_register(&hvs_transport, VSOCK_TRANSPORT_F_G2H); 916 if (ret) { 917 vmbus_driver_unregister(&hvs_drv); 918 return ret; 919 } 920 921 return 0; 922 } 923 924 static void __exit hvs_exit(void) 925 { 926 vsock_core_unregister(&hvs_transport); 927 vmbus_driver_unregister(&hvs_drv); 928 } 929 930 module_init(hvs_init); 931 module_exit(hvs_exit); 932 933 MODULE_DESCRIPTION("Hyper-V Sockets"); 934 MODULE_VERSION("1.0.0"); 935 MODULE_LICENSE("GPL"); 936 MODULE_ALIAS_NETPROTO(PF_VSOCK); 937