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