linux/net/vmw_vsock/virtio_transport_common.c
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   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#include <uapi/linux/vsockmon.h>
  20
  21#include <net/sock.h>
  22#include <net/af_vsock.h>
  23
  24#define CREATE_TRACE_POINTS
  25#include <trace/events/vsock_virtio_transport_common.h>
  26
  27/* How long to wait for graceful shutdown of a connection */
  28#define VSOCK_CLOSE_TIMEOUT (8 * HZ)
  29
  30static const struct virtio_transport *virtio_transport_get_ops(void)
  31{
  32        const struct vsock_transport *t = vsock_core_get_transport();
  33
  34        return container_of(t, struct virtio_transport, transport);
  35}
  36
  37static struct virtio_vsock_pkt *
  38virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,
  39                           size_t len,
  40                           u32 src_cid,
  41                           u32 src_port,
  42                           u32 dst_cid,
  43                           u32 dst_port)
  44{
  45        struct virtio_vsock_pkt *pkt;
  46        int err;
  47
  48        pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
  49        if (!pkt)
  50                return NULL;
  51
  52        pkt->hdr.type           = cpu_to_le16(info->type);
  53        pkt->hdr.op             = cpu_to_le16(info->op);
  54        pkt->hdr.src_cid        = cpu_to_le64(src_cid);
  55        pkt->hdr.dst_cid        = cpu_to_le64(dst_cid);
  56        pkt->hdr.src_port       = cpu_to_le32(src_port);
  57        pkt->hdr.dst_port       = cpu_to_le32(dst_port);
  58        pkt->hdr.flags          = cpu_to_le32(info->flags);
  59        pkt->len                = len;
  60        pkt->hdr.len            = cpu_to_le32(len);
  61        pkt->reply              = info->reply;
  62        pkt->vsk                = info->vsk;
  63
  64        if (info->msg && len > 0) {
  65                pkt->buf = kmalloc(len, GFP_KERNEL);
  66                if (!pkt->buf)
  67                        goto out_pkt;
  68                err = memcpy_from_msg(pkt->buf, info->msg, len);
  69                if (err)
  70                        goto out;
  71        }
  72
  73        trace_virtio_transport_alloc_pkt(src_cid, src_port,
  74                                         dst_cid, dst_port,
  75                                         len,
  76                                         info->type,
  77                                         info->op,
  78                                         info->flags);
  79
  80        return pkt;
  81
  82out:
  83        kfree(pkt->buf);
  84out_pkt:
  85        kfree(pkt);
  86        return NULL;
  87}
  88
  89/* Packet capture */
  90static struct sk_buff *virtio_transport_build_skb(void *opaque)
  91{
  92        struct virtio_vsock_pkt *pkt = opaque;
  93        struct af_vsockmon_hdr *hdr;
  94        struct sk_buff *skb;
  95
  96        skb = alloc_skb(sizeof(*hdr) + sizeof(pkt->hdr) + pkt->len,
  97                        GFP_ATOMIC);
  98        if (!skb)
  99                return NULL;
 100
 101        hdr = skb_put(skb, sizeof(*hdr));
 102
 103        /* pkt->hdr is little-endian so no need to byteswap here */
 104        hdr->src_cid = pkt->hdr.src_cid;
 105        hdr->src_port = pkt->hdr.src_port;
 106        hdr->dst_cid = pkt->hdr.dst_cid;
 107        hdr->dst_port = pkt->hdr.dst_port;
 108
 109        hdr->transport = cpu_to_le16(AF_VSOCK_TRANSPORT_VIRTIO);
 110        hdr->len = cpu_to_le16(sizeof(pkt->hdr));
 111        memset(hdr->reserved, 0, sizeof(hdr->reserved));
 112
 113        switch (le16_to_cpu(pkt->hdr.op)) {
 114        case VIRTIO_VSOCK_OP_REQUEST:
 115        case VIRTIO_VSOCK_OP_RESPONSE:
 116                hdr->op = cpu_to_le16(AF_VSOCK_OP_CONNECT);
 117                break;
 118        case VIRTIO_VSOCK_OP_RST:
 119        case VIRTIO_VSOCK_OP_SHUTDOWN:
 120                hdr->op = cpu_to_le16(AF_VSOCK_OP_DISCONNECT);
 121                break;
 122        case VIRTIO_VSOCK_OP_RW:
 123                hdr->op = cpu_to_le16(AF_VSOCK_OP_PAYLOAD);
 124                break;
 125        case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
 126        case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
 127                hdr->op = cpu_to_le16(AF_VSOCK_OP_CONTROL);
 128                break;
 129        default:
 130                hdr->op = cpu_to_le16(AF_VSOCK_OP_UNKNOWN);
 131                break;
 132        }
 133
 134        skb_put_data(skb, &pkt->hdr, sizeof(pkt->hdr));
 135
 136        if (pkt->len) {
 137                skb_put_data(skb, pkt->buf, pkt->len);
 138        }
 139
 140        return skb;
 141}
 142
 143void virtio_transport_deliver_tap_pkt(struct virtio_vsock_pkt *pkt)
 144{
 145        vsock_deliver_tap(virtio_transport_build_skb, pkt);
 146}
 147EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);
 148
 149static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
 150                                          struct virtio_vsock_pkt_info *info)
 151{
 152        u32 src_cid, src_port, dst_cid, dst_port;
 153        struct virtio_vsock_sock *vvs;
 154        struct virtio_vsock_pkt *pkt;
 155        u32 pkt_len = info->pkt_len;
 156
 157        src_cid = vm_sockets_get_local_cid();
 158        src_port = vsk->local_addr.svm_port;
 159        if (!info->remote_cid) {
 160                dst_cid = vsk->remote_addr.svm_cid;
 161                dst_port = vsk->remote_addr.svm_port;
 162        } else {
 163                dst_cid = info->remote_cid;
 164                dst_port = info->remote_port;
 165        }
 166
 167        vvs = vsk->trans;
 168
 169        /* we can send less than pkt_len bytes */
 170        if (pkt_len > VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE)
 171                pkt_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
 172
 173        /* virtio_transport_get_credit might return less than pkt_len credit */
 174        pkt_len = virtio_transport_get_credit(vvs, pkt_len);
 175
 176        /* Do not send zero length OP_RW pkt */
 177        if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
 178                return pkt_len;
 179
 180        pkt = virtio_transport_alloc_pkt(info, pkt_len,
 181                                         src_cid, src_port,
 182                                         dst_cid, dst_port);
 183        if (!pkt) {
 184                virtio_transport_put_credit(vvs, pkt_len);
 185                return -ENOMEM;
 186        }
 187
 188        virtio_transport_inc_tx_pkt(vvs, pkt);
 189
 190        return virtio_transport_get_ops()->send_pkt(pkt);
 191}
 192
 193static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
 194                                        struct virtio_vsock_pkt *pkt)
 195{
 196        vvs->rx_bytes += pkt->len;
 197}
 198
 199static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
 200                                        struct virtio_vsock_pkt *pkt)
 201{
 202        vvs->rx_bytes -= pkt->len;
 203        vvs->fwd_cnt += pkt->len;
 204}
 205
 206void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
 207{
 208        spin_lock_bh(&vvs->tx_lock);
 209        pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
 210        pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
 211        spin_unlock_bh(&vvs->tx_lock);
 212}
 213EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
 214
 215u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit)
 216{
 217        u32 ret;
 218
 219        spin_lock_bh(&vvs->tx_lock);
 220        ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
 221        if (ret > credit)
 222                ret = credit;
 223        vvs->tx_cnt += ret;
 224        spin_unlock_bh(&vvs->tx_lock);
 225
 226        return ret;
 227}
 228EXPORT_SYMBOL_GPL(virtio_transport_get_credit);
 229
 230void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit)
 231{
 232        spin_lock_bh(&vvs->tx_lock);
 233        vvs->tx_cnt -= credit;
 234        spin_unlock_bh(&vvs->tx_lock);
 235}
 236EXPORT_SYMBOL_GPL(virtio_transport_put_credit);
 237
 238static int virtio_transport_send_credit_update(struct vsock_sock *vsk,
 239                                               int type,
 240                                               struct virtio_vsock_hdr *hdr)
 241{
 242        struct virtio_vsock_pkt_info info = {
 243                .op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
 244                .type = type,
 245                .vsk = vsk,
 246        };
 247
 248        return virtio_transport_send_pkt_info(vsk, &info);
 249}
 250
 251static ssize_t
 252virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
 253                                   struct msghdr *msg,
 254                                   size_t len)
 255{
 256        struct virtio_vsock_sock *vvs = vsk->trans;
 257        struct virtio_vsock_pkt *pkt;
 258        size_t bytes, total = 0;
 259        int err = -EFAULT;
 260
 261        spin_lock_bh(&vvs->rx_lock);
 262        while (total < len && !list_empty(&vvs->rx_queue)) {
 263                pkt = list_first_entry(&vvs->rx_queue,
 264                                       struct virtio_vsock_pkt, list);
 265
 266                bytes = len - total;
 267                if (bytes > pkt->len - pkt->off)
 268                        bytes = pkt->len - pkt->off;
 269
 270                /* sk_lock is held by caller so no one else can dequeue.
 271                 * Unlock rx_lock since memcpy_to_msg() may sleep.
 272                 */
 273                spin_unlock_bh(&vvs->rx_lock);
 274
 275                err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes);
 276                if (err)
 277                        goto out;
 278
 279                spin_lock_bh(&vvs->rx_lock);
 280
 281                total += bytes;
 282                pkt->off += bytes;
 283                if (pkt->off == pkt->len) {
 284                        virtio_transport_dec_rx_pkt(vvs, pkt);
 285                        list_del(&pkt->list);
 286                        virtio_transport_free_pkt(pkt);
 287                }
 288        }
 289        spin_unlock_bh(&vvs->rx_lock);
 290
 291        /* Send a credit pkt to peer */
 292        virtio_transport_send_credit_update(vsk, VIRTIO_VSOCK_TYPE_STREAM,
 293                                            NULL);
 294
 295        return total;
 296
 297out:
 298        if (total)
 299                err = total;
 300        return err;
 301}
 302
 303ssize_t
 304virtio_transport_stream_dequeue(struct vsock_sock *vsk,
 305                                struct msghdr *msg,
 306                                size_t len, int flags)
 307{
 308        if (flags & MSG_PEEK)
 309                return -EOPNOTSUPP;
 310
 311        return virtio_transport_stream_do_dequeue(vsk, msg, len);
 312}
 313EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
 314
 315int
 316virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
 317                               struct msghdr *msg,
 318                               size_t len, int flags)
 319{
 320        return -EOPNOTSUPP;
 321}
 322EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
 323
 324s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
 325{
 326        struct virtio_vsock_sock *vvs = vsk->trans;
 327        s64 bytes;
 328
 329        spin_lock_bh(&vvs->rx_lock);
 330        bytes = vvs->rx_bytes;
 331        spin_unlock_bh(&vvs->rx_lock);
 332
 333        return bytes;
 334}
 335EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data);
 336
 337static s64 virtio_transport_has_space(struct vsock_sock *vsk)
 338{
 339        struct virtio_vsock_sock *vvs = vsk->trans;
 340        s64 bytes;
 341
 342        bytes = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
 343        if (bytes < 0)
 344                bytes = 0;
 345
 346        return bytes;
 347}
 348
 349s64 virtio_transport_stream_has_space(struct vsock_sock *vsk)
 350{
 351        struct virtio_vsock_sock *vvs = vsk->trans;
 352        s64 bytes;
 353
 354        spin_lock_bh(&vvs->tx_lock);
 355        bytes = virtio_transport_has_space(vsk);
 356        spin_unlock_bh(&vvs->tx_lock);
 357
 358        return bytes;
 359}
 360EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space);
 361
 362int virtio_transport_do_socket_init(struct vsock_sock *vsk,
 363                                    struct vsock_sock *psk)
 364{
 365        struct virtio_vsock_sock *vvs;
 366
 367        vvs = kzalloc(sizeof(*vvs), GFP_KERNEL);
 368        if (!vvs)
 369                return -ENOMEM;
 370
 371        vsk->trans = vvs;
 372        vvs->vsk = vsk;
 373        if (psk) {
 374                struct virtio_vsock_sock *ptrans = psk->trans;
 375
 376                vvs->buf_size   = ptrans->buf_size;
 377                vvs->buf_size_min = ptrans->buf_size_min;
 378                vvs->buf_size_max = ptrans->buf_size_max;
 379                vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
 380        } else {
 381                vvs->buf_size = VIRTIO_VSOCK_DEFAULT_BUF_SIZE;
 382                vvs->buf_size_min = VIRTIO_VSOCK_DEFAULT_MIN_BUF_SIZE;
 383                vvs->buf_size_max = VIRTIO_VSOCK_DEFAULT_MAX_BUF_SIZE;
 384        }
 385
 386        vvs->buf_alloc = vvs->buf_size;
 387
 388        spin_lock_init(&vvs->rx_lock);
 389        spin_lock_init(&vvs->tx_lock);
 390        INIT_LIST_HEAD(&vvs->rx_queue);
 391
 392        return 0;
 393}
 394EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init);
 395
 396u64 virtio_transport_get_buffer_size(struct vsock_sock *vsk)
 397{
 398        struct virtio_vsock_sock *vvs = vsk->trans;
 399
 400        return vvs->buf_size;
 401}
 402EXPORT_SYMBOL_GPL(virtio_transport_get_buffer_size);
 403
 404u64 virtio_transport_get_min_buffer_size(struct vsock_sock *vsk)
 405{
 406        struct virtio_vsock_sock *vvs = vsk->trans;
 407
 408        return vvs->buf_size_min;
 409}
 410EXPORT_SYMBOL_GPL(virtio_transport_get_min_buffer_size);
 411
 412u64 virtio_transport_get_max_buffer_size(struct vsock_sock *vsk)
 413{
 414        struct virtio_vsock_sock *vvs = vsk->trans;
 415
 416        return vvs->buf_size_max;
 417}
 418EXPORT_SYMBOL_GPL(virtio_transport_get_max_buffer_size);
 419
 420void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val)
 421{
 422        struct virtio_vsock_sock *vvs = vsk->trans;
 423
 424        if (val > VIRTIO_VSOCK_MAX_BUF_SIZE)
 425                val = VIRTIO_VSOCK_MAX_BUF_SIZE;
 426        if (val < vvs->buf_size_min)
 427                vvs->buf_size_min = val;
 428        if (val > vvs->buf_size_max)
 429                vvs->buf_size_max = val;
 430        vvs->buf_size = val;
 431        vvs->buf_alloc = val;
 432}
 433EXPORT_SYMBOL_GPL(virtio_transport_set_buffer_size);
 434
 435void virtio_transport_set_min_buffer_size(struct vsock_sock *vsk, u64 val)
 436{
 437        struct virtio_vsock_sock *vvs = vsk->trans;
 438
 439        if (val > VIRTIO_VSOCK_MAX_BUF_SIZE)
 440                val = VIRTIO_VSOCK_MAX_BUF_SIZE;
 441        if (val > vvs->buf_size)
 442                vvs->buf_size = val;
 443        vvs->buf_size_min = val;
 444}
 445EXPORT_SYMBOL_GPL(virtio_transport_set_min_buffer_size);
 446
 447void virtio_transport_set_max_buffer_size(struct vsock_sock *vsk, u64 val)
 448{
 449        struct virtio_vsock_sock *vvs = vsk->trans;
 450
 451        if (val > VIRTIO_VSOCK_MAX_BUF_SIZE)
 452                val = VIRTIO_VSOCK_MAX_BUF_SIZE;
 453        if (val < vvs->buf_size)
 454                vvs->buf_size = val;
 455        vvs->buf_size_max = val;
 456}
 457EXPORT_SYMBOL_GPL(virtio_transport_set_max_buffer_size);
 458
 459int
 460virtio_transport_notify_poll_in(struct vsock_sock *vsk,
 461                                size_t target,
 462                                bool *data_ready_now)
 463{
 464        if (vsock_stream_has_data(vsk))
 465                *data_ready_now = true;
 466        else
 467                *data_ready_now = false;
 468
 469        return 0;
 470}
 471EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in);
 472
 473int
 474virtio_transport_notify_poll_out(struct vsock_sock *vsk,
 475                                 size_t target,
 476                                 bool *space_avail_now)
 477{
 478        s64 free_space;
 479
 480        free_space = vsock_stream_has_space(vsk);
 481        if (free_space > 0)
 482                *space_avail_now = true;
 483        else if (free_space == 0)
 484                *space_avail_now = false;
 485
 486        return 0;
 487}
 488EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out);
 489
 490int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
 491        size_t target, struct vsock_transport_recv_notify_data *data)
 492{
 493        return 0;
 494}
 495EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init);
 496
 497int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
 498        size_t target, struct vsock_transport_recv_notify_data *data)
 499{
 500        return 0;
 501}
 502EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block);
 503
 504int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
 505        size_t target, struct vsock_transport_recv_notify_data *data)
 506{
 507        return 0;
 508}
 509EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue);
 510
 511int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
 512        size_t target, ssize_t copied, bool data_read,
 513        struct vsock_transport_recv_notify_data *data)
 514{
 515        return 0;
 516}
 517EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue);
 518
 519int virtio_transport_notify_send_init(struct vsock_sock *vsk,
 520        struct vsock_transport_send_notify_data *data)
 521{
 522        return 0;
 523}
 524EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init);
 525
 526int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
 527        struct vsock_transport_send_notify_data *data)
 528{
 529        return 0;
 530}
 531EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block);
 532
 533int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
 534        struct vsock_transport_send_notify_data *data)
 535{
 536        return 0;
 537}
 538EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue);
 539
 540int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
 541        ssize_t written, struct vsock_transport_send_notify_data *data)
 542{
 543        return 0;
 544}
 545EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue);
 546
 547u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk)
 548{
 549        struct virtio_vsock_sock *vvs = vsk->trans;
 550
 551        return vvs->buf_size;
 552}
 553EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat);
 554
 555bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
 556{
 557        return true;
 558}
 559EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
 560
 561bool virtio_transport_stream_allow(u32 cid, u32 port)
 562{
 563        return true;
 564}
 565EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
 566
 567int virtio_transport_dgram_bind(struct vsock_sock *vsk,
 568                                struct sockaddr_vm *addr)
 569{
 570        return -EOPNOTSUPP;
 571}
 572EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
 573
 574bool virtio_transport_dgram_allow(u32 cid, u32 port)
 575{
 576        return false;
 577}
 578EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
 579
 580int virtio_transport_connect(struct vsock_sock *vsk)
 581{
 582        struct virtio_vsock_pkt_info info = {
 583                .op = VIRTIO_VSOCK_OP_REQUEST,
 584                .type = VIRTIO_VSOCK_TYPE_STREAM,
 585                .vsk = vsk,
 586        };
 587
 588        return virtio_transport_send_pkt_info(vsk, &info);
 589}
 590EXPORT_SYMBOL_GPL(virtio_transport_connect);
 591
 592int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
 593{
 594        struct virtio_vsock_pkt_info info = {
 595                .op = VIRTIO_VSOCK_OP_SHUTDOWN,
 596                .type = VIRTIO_VSOCK_TYPE_STREAM,
 597                .flags = (mode & RCV_SHUTDOWN ?
 598                          VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
 599                         (mode & SEND_SHUTDOWN ?
 600                          VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
 601                .vsk = vsk,
 602        };
 603
 604        return virtio_transport_send_pkt_info(vsk, &info);
 605}
 606EXPORT_SYMBOL_GPL(virtio_transport_shutdown);
 607
 608int
 609virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
 610                               struct sockaddr_vm *remote_addr,
 611                               struct msghdr *msg,
 612                               size_t dgram_len)
 613{
 614        return -EOPNOTSUPP;
 615}
 616EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
 617
 618ssize_t
 619virtio_transport_stream_enqueue(struct vsock_sock *vsk,
 620                                struct msghdr *msg,
 621                                size_t len)
 622{
 623        struct virtio_vsock_pkt_info info = {
 624                .op = VIRTIO_VSOCK_OP_RW,
 625                .type = VIRTIO_VSOCK_TYPE_STREAM,
 626                .msg = msg,
 627                .pkt_len = len,
 628                .vsk = vsk,
 629        };
 630
 631        return virtio_transport_send_pkt_info(vsk, &info);
 632}
 633EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);
 634
 635void virtio_transport_destruct(struct vsock_sock *vsk)
 636{
 637        struct virtio_vsock_sock *vvs = vsk->trans;
 638
 639        kfree(vvs);
 640}
 641EXPORT_SYMBOL_GPL(virtio_transport_destruct);
 642
 643static int virtio_transport_reset(struct vsock_sock *vsk,
 644                                  struct virtio_vsock_pkt *pkt)
 645{
 646        struct virtio_vsock_pkt_info info = {
 647                .op = VIRTIO_VSOCK_OP_RST,
 648                .type = VIRTIO_VSOCK_TYPE_STREAM,
 649                .reply = !!pkt,
 650                .vsk = vsk,
 651        };
 652
 653        /* Send RST only if the original pkt is not a RST pkt */
 654        if (pkt && le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
 655                return 0;
 656
 657        return virtio_transport_send_pkt_info(vsk, &info);
 658}
 659
 660/* Normally packets are associated with a socket.  There may be no socket if an
 661 * attempt was made to connect to a socket that does not exist.
 662 */
 663static int virtio_transport_reset_no_sock(struct virtio_vsock_pkt *pkt)
 664{
 665        struct virtio_vsock_pkt_info info = {
 666                .op = VIRTIO_VSOCK_OP_RST,
 667                .type = le16_to_cpu(pkt->hdr.type),
 668                .reply = true,
 669        };
 670
 671        /* Send RST only if the original pkt is not a RST pkt */
 672        if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
 673                return 0;
 674
 675        pkt = virtio_transport_alloc_pkt(&info, 0,
 676                                         le64_to_cpu(pkt->hdr.dst_cid),
 677                                         le32_to_cpu(pkt->hdr.dst_port),
 678                                         le64_to_cpu(pkt->hdr.src_cid),
 679                                         le32_to_cpu(pkt->hdr.src_port));
 680        if (!pkt)
 681                return -ENOMEM;
 682
 683        return virtio_transport_get_ops()->send_pkt(pkt);
 684}
 685
 686static void virtio_transport_wait_close(struct sock *sk, long timeout)
 687{
 688        if (timeout) {
 689                DEFINE_WAIT_FUNC(wait, woken_wake_function);
 690
 691                add_wait_queue(sk_sleep(sk), &wait);
 692
 693                do {
 694                        if (sk_wait_event(sk, &timeout,
 695                                          sock_flag(sk, SOCK_DONE), &wait))
 696                                break;
 697                } while (!signal_pending(current) && timeout);
 698
 699                remove_wait_queue(sk_sleep(sk), &wait);
 700        }
 701}
 702
 703static void virtio_transport_do_close(struct vsock_sock *vsk,
 704                                      bool cancel_timeout)
 705{
 706        struct sock *sk = sk_vsock(vsk);
 707
 708        sock_set_flag(sk, SOCK_DONE);
 709        vsk->peer_shutdown = SHUTDOWN_MASK;
 710        if (vsock_stream_has_data(vsk) <= 0)
 711                sk->sk_state = SS_DISCONNECTING;
 712        sk->sk_state_change(sk);
 713
 714        if (vsk->close_work_scheduled &&
 715            (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
 716                vsk->close_work_scheduled = false;
 717
 718                vsock_remove_sock(vsk);
 719
 720                /* Release refcnt obtained when we scheduled the timeout */
 721                sock_put(sk);
 722        }
 723}
 724
 725static void virtio_transport_close_timeout(struct work_struct *work)
 726{
 727        struct vsock_sock *vsk =
 728                container_of(work, struct vsock_sock, close_work.work);
 729        struct sock *sk = sk_vsock(vsk);
 730
 731        sock_hold(sk);
 732        lock_sock(sk);
 733
 734        if (!sock_flag(sk, SOCK_DONE)) {
 735                (void)virtio_transport_reset(vsk, NULL);
 736
 737                virtio_transport_do_close(vsk, false);
 738        }
 739
 740        vsk->close_work_scheduled = false;
 741
 742        release_sock(sk);
 743        sock_put(sk);
 744}
 745
 746/* User context, vsk->sk is locked */
 747static bool virtio_transport_close(struct vsock_sock *vsk)
 748{
 749        struct sock *sk = &vsk->sk;
 750
 751        if (!(sk->sk_state == SS_CONNECTED ||
 752              sk->sk_state == SS_DISCONNECTING))
 753                return true;
 754
 755        /* Already received SHUTDOWN from peer, reply with RST */
 756        if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) {
 757                (void)virtio_transport_reset(vsk, NULL);
 758                return true;
 759        }
 760
 761        if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
 762                (void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
 763
 764        if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
 765                virtio_transport_wait_close(sk, sk->sk_lingertime);
 766
 767        if (sock_flag(sk, SOCK_DONE)) {
 768                return true;
 769        }
 770
 771        sock_hold(sk);
 772        INIT_DELAYED_WORK(&vsk->close_work,
 773                          virtio_transport_close_timeout);
 774        vsk->close_work_scheduled = true;
 775        schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT);
 776        return false;
 777}
 778
 779void virtio_transport_release(struct vsock_sock *vsk)
 780{
 781        struct sock *sk = &vsk->sk;
 782        bool remove_sock = true;
 783
 784        lock_sock(sk);
 785        if (sk->sk_type == SOCK_STREAM)
 786                remove_sock = virtio_transport_close(vsk);
 787        release_sock(sk);
 788
 789        if (remove_sock)
 790                vsock_remove_sock(vsk);
 791}
 792EXPORT_SYMBOL_GPL(virtio_transport_release);
 793
 794static int
 795virtio_transport_recv_connecting(struct sock *sk,
 796                                 struct virtio_vsock_pkt *pkt)
 797{
 798        struct vsock_sock *vsk = vsock_sk(sk);
 799        int err;
 800        int skerr;
 801
 802        switch (le16_to_cpu(pkt->hdr.op)) {
 803        case VIRTIO_VSOCK_OP_RESPONSE:
 804                sk->sk_state = SS_CONNECTED;
 805                sk->sk_socket->state = SS_CONNECTED;
 806                vsock_insert_connected(vsk);
 807                sk->sk_state_change(sk);
 808                break;
 809        case VIRTIO_VSOCK_OP_INVALID:
 810                break;
 811        case VIRTIO_VSOCK_OP_RST:
 812                skerr = ECONNRESET;
 813                err = 0;
 814                goto destroy;
 815        default:
 816                skerr = EPROTO;
 817                err = -EINVAL;
 818                goto destroy;
 819        }
 820        return 0;
 821
 822destroy:
 823        virtio_transport_reset(vsk, pkt);
 824        sk->sk_state = SS_UNCONNECTED;
 825        sk->sk_err = skerr;
 826        sk->sk_error_report(sk);
 827        return err;
 828}
 829
 830static int
 831virtio_transport_recv_connected(struct sock *sk,
 832                                struct virtio_vsock_pkt *pkt)
 833{
 834        struct vsock_sock *vsk = vsock_sk(sk);
 835        struct virtio_vsock_sock *vvs = vsk->trans;
 836        int err = 0;
 837
 838        switch (le16_to_cpu(pkt->hdr.op)) {
 839        case VIRTIO_VSOCK_OP_RW:
 840                pkt->len = le32_to_cpu(pkt->hdr.len);
 841                pkt->off = 0;
 842
 843                spin_lock_bh(&vvs->rx_lock);
 844                virtio_transport_inc_rx_pkt(vvs, pkt);
 845                list_add_tail(&pkt->list, &vvs->rx_queue);
 846                spin_unlock_bh(&vvs->rx_lock);
 847
 848                sk->sk_data_ready(sk);
 849                return err;
 850        case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
 851                sk->sk_write_space(sk);
 852                break;
 853        case VIRTIO_VSOCK_OP_SHUTDOWN:
 854                if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
 855                        vsk->peer_shutdown |= RCV_SHUTDOWN;
 856                if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
 857                        vsk->peer_shutdown |= SEND_SHUTDOWN;
 858                if (vsk->peer_shutdown == SHUTDOWN_MASK &&
 859                    vsock_stream_has_data(vsk) <= 0)
 860                        sk->sk_state = SS_DISCONNECTING;
 861                if (le32_to_cpu(pkt->hdr.flags))
 862                        sk->sk_state_change(sk);
 863                break;
 864        case VIRTIO_VSOCK_OP_RST:
 865                virtio_transport_do_close(vsk, true);
 866                break;
 867        default:
 868                err = -EINVAL;
 869                break;
 870        }
 871
 872        virtio_transport_free_pkt(pkt);
 873        return err;
 874}
 875
 876static void
 877virtio_transport_recv_disconnecting(struct sock *sk,
 878                                    struct virtio_vsock_pkt *pkt)
 879{
 880        struct vsock_sock *vsk = vsock_sk(sk);
 881
 882        if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
 883                virtio_transport_do_close(vsk, true);
 884}
 885
 886static int
 887virtio_transport_send_response(struct vsock_sock *vsk,
 888                               struct virtio_vsock_pkt *pkt)
 889{
 890        struct virtio_vsock_pkt_info info = {
 891                .op = VIRTIO_VSOCK_OP_RESPONSE,
 892                .type = VIRTIO_VSOCK_TYPE_STREAM,
 893                .remote_cid = le64_to_cpu(pkt->hdr.src_cid),
 894                .remote_port = le32_to_cpu(pkt->hdr.src_port),
 895                .reply = true,
 896                .vsk = vsk,
 897        };
 898
 899        return virtio_transport_send_pkt_info(vsk, &info);
 900}
 901
 902/* Handle server socket */
 903static int
 904virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt)
 905{
 906        struct vsock_sock *vsk = vsock_sk(sk);
 907        struct vsock_sock *vchild;
 908        struct sock *child;
 909
 910        if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_REQUEST) {
 911                virtio_transport_reset(vsk, pkt);
 912                return -EINVAL;
 913        }
 914
 915        if (sk_acceptq_is_full(sk)) {
 916                virtio_transport_reset(vsk, pkt);
 917                return -ENOMEM;
 918        }
 919
 920        child = __vsock_create(sock_net(sk), NULL, sk, GFP_KERNEL,
 921                               sk->sk_type, 0);
 922        if (!child) {
 923                virtio_transport_reset(vsk, pkt);
 924                return -ENOMEM;
 925        }
 926
 927        sk->sk_ack_backlog++;
 928
 929        lock_sock_nested(child, SINGLE_DEPTH_NESTING);
 930
 931        child->sk_state = SS_CONNECTED;
 932
 933        vchild = vsock_sk(child);
 934        vsock_addr_init(&vchild->local_addr, le64_to_cpu(pkt->hdr.dst_cid),
 935                        le32_to_cpu(pkt->hdr.dst_port));
 936        vsock_addr_init(&vchild->remote_addr, le64_to_cpu(pkt->hdr.src_cid),
 937                        le32_to_cpu(pkt->hdr.src_port));
 938
 939        vsock_insert_connected(vchild);
 940        vsock_enqueue_accept(sk, child);
 941        virtio_transport_send_response(vchild, pkt);
 942
 943        release_sock(child);
 944
 945        sk->sk_data_ready(sk);
 946        return 0;
 947}
 948
 949static bool virtio_transport_space_update(struct sock *sk,
 950                                          struct virtio_vsock_pkt *pkt)
 951{
 952        struct vsock_sock *vsk = vsock_sk(sk);
 953        struct virtio_vsock_sock *vvs = vsk->trans;
 954        bool space_available;
 955
 956        /* buf_alloc and fwd_cnt is always included in the hdr */
 957        spin_lock_bh(&vvs->tx_lock);
 958        vvs->peer_buf_alloc = le32_to_cpu(pkt->hdr.buf_alloc);
 959        vvs->peer_fwd_cnt = le32_to_cpu(pkt->hdr.fwd_cnt);
 960        space_available = virtio_transport_has_space(vsk);
 961        spin_unlock_bh(&vvs->tx_lock);
 962        return space_available;
 963}
 964
 965/* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
 966 * lock.
 967 */
 968void virtio_transport_recv_pkt(struct virtio_vsock_pkt *pkt)
 969{
 970        struct sockaddr_vm src, dst;
 971        struct vsock_sock *vsk;
 972        struct sock *sk;
 973        bool space_available;
 974
 975        vsock_addr_init(&src, le64_to_cpu(pkt->hdr.src_cid),
 976                        le32_to_cpu(pkt->hdr.src_port));
 977        vsock_addr_init(&dst, le64_to_cpu(pkt->hdr.dst_cid),
 978                        le32_to_cpu(pkt->hdr.dst_port));
 979
 980        trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
 981                                        dst.svm_cid, dst.svm_port,
 982                                        le32_to_cpu(pkt->hdr.len),
 983                                        le16_to_cpu(pkt->hdr.type),
 984                                        le16_to_cpu(pkt->hdr.op),
 985                                        le32_to_cpu(pkt->hdr.flags),
 986                                        le32_to_cpu(pkt->hdr.buf_alloc),
 987                                        le32_to_cpu(pkt->hdr.fwd_cnt));
 988
 989        if (le16_to_cpu(pkt->hdr.type) != VIRTIO_VSOCK_TYPE_STREAM) {
 990                (void)virtio_transport_reset_no_sock(pkt);
 991                goto free_pkt;
 992        }
 993
 994        /* The socket must be in connected or bound table
 995         * otherwise send reset back
 996         */
 997        sk = vsock_find_connected_socket(&src, &dst);
 998        if (!sk) {
 999                sk = vsock_find_bound_socket(&dst);
1000                if (!sk) {
1001                        (void)virtio_transport_reset_no_sock(pkt);
1002                        goto free_pkt;
1003                }
1004        }
1005
1006        vsk = vsock_sk(sk);
1007
1008        space_available = virtio_transport_space_update(sk, pkt);
1009
1010        lock_sock(sk);
1011
1012        /* Update CID in case it has changed after a transport reset event */
1013        vsk->local_addr.svm_cid = dst.svm_cid;
1014
1015        if (space_available)
1016                sk->sk_write_space(sk);
1017
1018        switch (sk->sk_state) {
1019        case VSOCK_SS_LISTEN:
1020                virtio_transport_recv_listen(sk, pkt);
1021                virtio_transport_free_pkt(pkt);
1022                break;
1023        case SS_CONNECTING:
1024                virtio_transport_recv_connecting(sk, pkt);
1025                virtio_transport_free_pkt(pkt);
1026                break;
1027        case SS_CONNECTED:
1028                virtio_transport_recv_connected(sk, pkt);
1029                break;
1030        case SS_DISCONNECTING:
1031                virtio_transport_recv_disconnecting(sk, pkt);
1032                virtio_transport_free_pkt(pkt);
1033                break;
1034        default:
1035                virtio_transport_free_pkt(pkt);
1036                break;
1037        }
1038        release_sock(sk);
1039
1040        /* Release refcnt obtained when we fetched this socket out of the
1041         * bound or connected list.
1042         */
1043        sock_put(sk);
1044        return;
1045
1046free_pkt:
1047        virtio_transport_free_pkt(pkt);
1048}
1049EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
1050
1051void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
1052{
1053        kfree(pkt->buf);
1054        kfree(pkt);
1055}
1056EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);
1057
1058MODULE_LICENSE("GPL v2");
1059MODULE_AUTHOR("Asias He");
1060MODULE_DESCRIPTION("common code for virtio vsock");
1061