src/vnet/devices/virtio/node.c

   1 /*
   2  *------------------------------------------------------------------
   3  * Copyright (c) 2016 Cisco and/or its affiliates.
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  *------------------------------------------------------------------
  16  */
  17
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20 #include <fcntl.h>
  21 #include <net/if.h>
  22 #ifdef __linux__
  23 #include <linux/if_tun.h>
  24 #elif __FreeBSD__
  25 #include <net/if_tun.h>
  26 #endif /* __linux */
  27 #include <sys/ioctl.h>
  28 #include <sys/eventfd.h>
  29
  30 #include <vlib/vlib.h>
  31 #include <vlib/unix/unix.h>
  32 #include <vnet/ethernet/ethernet.h>
  33 #include <vnet/feature/feature.h>
  34 #include <vnet/interface/rx_queue_funcs.h>
  35 #include <vnet/ip/ip4_packet.h>
  36 #include <vnet/ip/ip6_packet.h>
  37 #include <vnet/udp/udp_packet.h>
  38 #include <vnet/tcp/tcp_packet.h>
  39 #include <vnet/devices/virtio/virtio.h>
  40 #include <vnet/devices/virtio/virtio_inline.h>
  41
  42 static char *virtio_input_error_strings[] = {
  43 #define _(n, s) s,
  44   foreach_virtio_input_error
  45 #undef _
  46 };
  47
  48 typedef struct
  49 {
  50   u32 next_index;
  51   u32 hw_if_index;
  52   u16 ring;
  53   u16 len;
  54   vnet_virtio_net_hdr_v1_t hdr;
  55 } virtio_input_trace_t;
  56
  57 static u8 *
  58 format_virtio_input_trace (u8 * s, va_list * args)
  59 {
  60   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  61   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  62   virtio_input_trace_t *t = va_arg (*args, virtio_input_trace_t *);
  63   u32 indent = format_get_indent (s);
  64
  65   s = format (s, "virtio: hw_if_index %d next-index %d vring %u len %u",
  66               t->hw_if_index, t->next_index, t->ring, t->len);
  67   s = format (s, "\n%Uhdr: flags 0x%02x gso_type 0x%02x hdr_len %u "
  68               "gso_size %u csum_start %u csum_offset %u num_buffers %u",
  69               format_white_space, indent + 2,
  70               t->hdr.flags, t->hdr.gso_type, t->hdr.hdr_len, t->hdr.gso_size,
  71               t->hdr.csum_start, t->hdr.csum_offset, t->hdr.num_buffers);
  72   return s;
  73 }
  74
  75 static_always_inline void
  76 virtio_needs_csum (vlib_buffer_t *b0, vnet_virtio_net_hdr_v1_t *hdr,
  77                    u8 *l4_proto, u8 *l4_hdr_sz, virtio_if_type_t type)
  78 {
  79   if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
  80     {
  81       u16 ethertype = 0, l2hdr_sz = 0;
  82       vnet_buffer_oflags_t oflags = 0;
  83
  84       if (type == VIRTIO_IF_TYPE_TUN)
  85         {
  86           switch (b0->data[0] & 0xf0)
  87             {
  88             case 0x40:
  89               ethertype = ETHERNET_TYPE_IP4;
  90               break;
  91             case 0x60:
  92               ethertype = ETHERNET_TYPE_IP6;
  93               break;
  94             }
  95         }
  96       else
  97         {
  98           ethernet_header_t *eh = (ethernet_header_t *) b0->data;
  99           ethertype = clib_net_to_host_u16 (eh->type);
 100           l2hdr_sz = sizeof (ethernet_header_t);
 101
 102           if (ethernet_frame_is_tagged (ethertype))
 103             {
 104               ethernet_vlan_header_t *vlan =
 105                 (ethernet_vlan_header_t *) (eh + 1);
 106
 107               ethertype = clib_net_to_host_u16 (vlan->type);
 108               l2hdr_sz += sizeof (*vlan);
 109               if (ethertype == ETHERNET_TYPE_VLAN)
 110                 {
 111                   vlan++;
 112                   ethertype = clib_net_to_host_u16 (vlan->type);
 113                   l2hdr_sz += sizeof (*vlan);
 114                 }
 115             }
 116         }
 117
 118       vnet_buffer (b0)->l2_hdr_offset = 0;
 119       vnet_buffer (b0)->l3_hdr_offset = l2hdr_sz;
 120
 121       if (PREDICT_TRUE (ethertype == ETHERNET_TYPE_IP4))
 122         {
 123           ip4_header_t *ip4 = (ip4_header_t *) (b0->data + l2hdr_sz);
 124           vnet_buffer (b0)->l4_hdr_offset = l2hdr_sz + ip4_header_bytes (ip4);
 125           *l4_proto = ip4->protocol;
 126           oflags |= VNET_BUFFER_OFFLOAD_F_IP_CKSUM;
 127           b0->flags |=
 128             (VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_L2_HDR_OFFSET_VALID |
 129              VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
 130              VNET_BUFFER_F_L4_HDR_OFFSET_VALID);
 131         }
 132       else if (PREDICT_TRUE (ethertype == ETHERNET_TYPE_IP6))
 133         {
 134           ip6_header_t *ip6 = (ip6_header_t *) (b0->data + l2hdr_sz);
 135           vnet_buffer (b0)->l4_hdr_offset = l2hdr_sz + sizeof (ip6_header_t);
 136           /* FIXME IPv6 EH traversal */
 137           *l4_proto = ip6->protocol;
 138           b0->flags |= (VNET_BUFFER_F_IS_IP6 |
 139                         VNET_BUFFER_F_L2_HDR_OFFSET_VALID
 140                         | VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
 141                         VNET_BUFFER_F_L4_HDR_OFFSET_VALID);
 142         }
 143       if (*l4_proto == IP_PROTOCOL_TCP)
 144         {
 145           oflags |= VNET_BUFFER_OFFLOAD_F_TCP_CKSUM;
 146           tcp_header_t *tcp =
 147             (tcp_header_t *) (b0->data + vnet_buffer (b0)->l4_hdr_offset);
 148           *l4_hdr_sz = tcp_header_bytes (tcp);
 149         }
 150       else if (*l4_proto == IP_PROTOCOL_UDP)
 151         {
 152           oflags |= VNET_BUFFER_OFFLOAD_F_UDP_CKSUM;
 153           *l4_hdr_sz = sizeof (udp_header_t);
 154         }
 155       if (oflags)
 156         vnet_buffer_offload_flags_set (b0, oflags);
 157     }
 158 }
 159
 160 static_always_inline void
 161 fill_gso_buffer_flags (vlib_buffer_t *b0, vnet_virtio_net_hdr_v1_t *hdr,
 162                        u8 l4_proto, u8 l4_hdr_sz)
 163 {
 164   if (hdr->gso_type == VIRTIO_NET_HDR_GSO_TCPV4)
 165     {
 166       ASSERT (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM);
 167       vnet_buffer2 (b0)->gso_size = hdr->gso_size;
 168       vnet_buffer2 (b0)->gso_l4_hdr_sz = l4_hdr_sz;
 169       b0->flags |= VNET_BUFFER_F_GSO | VNET_BUFFER_F_IS_IP4;
 170     }
 171   if (hdr->gso_type == VIRTIO_NET_HDR_GSO_TCPV6)
 172     {
 173       ASSERT (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM);
 174       vnet_buffer2 (b0)->gso_size = hdr->gso_size;
 175       vnet_buffer2 (b0)->gso_l4_hdr_sz = l4_hdr_sz;
 176       b0->flags |= VNET_BUFFER_F_GSO | VNET_BUFFER_F_IS_IP6;
 177     }
 178 }
 179
 180 static_always_inline u16
 181 virtio_n_left_to_process (vnet_virtio_vring_t *vring, const int packed)
 182 {
 183   if (packed)
 184     return vring->desc_in_use;
 185   else
 186     return vring->used->idx - vring->last_used_idx;
 187 }
 188
 189 static_always_inline u16
 190 virtio_get_slot_id (vnet_virtio_vring_t *vring, const int packed, u16 last,
 191                     u16 mask)
 192 {
 193   if (packed)
 194     return vring->packed_desc[last].id;
 195   else
 196     return vring->used->ring[last & mask].id;
 197 }
 198
 199 static_always_inline u16
 200 virtio_get_len (vnet_virtio_vring_t *vring, const int packed, const int hdr_sz,
 201                 u16 last, u16 mask)
 202 {
 203   if (packed)
 204     return vring->packed_desc[last].len - hdr_sz;
 205   else
 206     return vring->used->ring[last & mask].len - hdr_sz;
 207 }
 208
 209 #define virtio_packed_check_n_left(vring, last)                               \
 210   do                                                                          \
 211     {                                                                         \
 212       vnet_virtio_vring_packed_desc_t *d = &vring->packed_desc[last];         \
 213       u16 flags = d->flags;                                                   \
 214       if ((flags & VRING_DESC_F_AVAIL) != (vring->used_wrap_counter << 7) ||  \
 215           (flags & VRING_DESC_F_USED) != (vring->used_wrap_counter << 15))    \
 216         {                                                                     \
 217           n_left = 0;                                                         \
 218         }                                                                     \
 219     }                                                                         \
 220   while (0)
 221
 222 #define increment_last(last, packed, vring)                                   \
 223   do                                                                          \
 224     {                                                                         \
 225       last++;                                                                 \
 226       if (packed && last >= vring->queue_size)                                \
 227         {                                                                     \
 228           last = 0;                                                           \
 229           vring->used_wrap_counter ^= 1;                                      \
 230         }                                                                     \
 231     }                                                                         \
 232   while (0)
 233
 234 static_always_inline void
 235 virtio_device_input_ethernet (vlib_main_t *vm, vlib_node_runtime_t *node,
 236                               const u32 next_index, const u32 sw_if_index,
 237                               const u32 hw_if_index)
 238 {
 239   vlib_next_frame_t *nf;
 240   vlib_frame_t *f;
 241   ethernet_input_frame_t *ef;
 242
 243   if (PREDICT_FALSE (VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT != next_index))
 244     return;
 245
 246   nf = vlib_node_runtime_get_next_frame (
 247     vm, node, VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT);
 248   f = vlib_get_frame (vm, nf->frame);
 249   f->flags = ETH_INPUT_FRAME_F_SINGLE_SW_IF_IDX;
 250
 251   ef = vlib_frame_scalar_args (f);
 252   ef->sw_if_index = sw_if_index;
 253   ef->hw_if_index = hw_if_index;
 254   vlib_frame_no_append (f);
 255 }
 256
 257 static_always_inline uword
 258 virtio_device_input_gso_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
 259                                 vlib_frame_t *frame, virtio_if_t *vif,
 260                                 vnet_virtio_vring_t *vring,
 261                                 virtio_if_type_t type, int gso_enabled,
 262                                 int checksum_offload_enabled, int packed)
 263 {
 264   vnet_main_t *vnm = vnet_get_main ();
 265   u32 thread_index = vm->thread_index;
 266   uword n_trace = vlib_get_trace_count (vm, node);
 267   u32 next_index;
 268   const int hdr_sz = vif->virtio_net_hdr_sz;
 269   u32 *to_next = 0;
 270   u32 n_rx_packets = 0;
 271   u32 n_rx_bytes = 0;
 272   u16 mask = vring->queue_size - 1;
 273   u16 last = vring->last_used_idx;
 274   u16 n_left = virtio_n_left_to_process (vring, packed);
 275   vlib_buffer_t bt = {};
 276
 277   if (packed)
 278     {
 279       virtio_packed_check_n_left (vring, last);
 280     }
 281
 282   if (n_left == 0)
 283     return 0;
 284
 285   if (PREDICT_FALSE (n_left == vring->queue_size))
 286     {
 287       /*
 288        * Informational error logging when VPP is not pulling packets fast
 289        * enough.
 290        */
 291       vlib_error_count (vm, node->node_index, VIRTIO_INPUT_ERROR_FULL_RX_QUEUE,
 292                         1);
 293     }
 294
 295   if (type == VIRTIO_IF_TYPE_TUN)
 296     {
 297       next_index = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
 298     }
 299   else
 300     {
 301       next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
 302       if (PREDICT_FALSE (vif->per_interface_next_index != ~0))
 303         next_index = vif->per_interface_next_index;
 304
 305       /* only for l2, redirect if feature path enabled */
 306       vnet_feature_start_device_input (vif->sw_if_index, &next_index, &bt);
 307     }
 308
 309   while (n_left)
 310     {
 311       u32 n_left_to_next;
 312       u32 next0 = next_index;
 313
 314       vlib_get_new_next_frame (vm, node, next_index, to_next, n_left_to_next);
 315
 316       while (n_left && n_left_to_next)
 317         {
 318           if (packed)
 319             {
 320               vnet_virtio_vring_packed_desc_t *d = &vring->packed_desc[last];
 321               u16 flags = d->flags;
 322               if ((flags & VRING_DESC_F_AVAIL) !=
 323                   (vring->used_wrap_counter << 7)
 324                   || (flags & VRING_DESC_F_USED) !=
 325                   (vring->used_wrap_counter << 15))
 326                 {
 327                   n_left = 0;
 328                   break;
 329                 }
 330             }
 331           u8 l4_proto = 0, l4_hdr_sz = 0;
 332           u16 num_buffers = 1;
 333           vnet_virtio_net_hdr_v1_t *hdr;
 334           u16 slot = virtio_get_slot_id (vring, packed, last, mask);
 335           u16 len = virtio_get_len (vring, packed, hdr_sz, last, mask);
 336           u32 bi0 = vring->buffers[slot];
 337           vlib_buffer_t *b0 = vlib_get_buffer (vm, bi0);
 338           hdr = vlib_buffer_get_current (b0);
 339           if (hdr_sz == sizeof (vnet_virtio_net_hdr_v1_t))
 340             num_buffers = hdr->num_buffers;
 341
 342           b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
 343           b0->current_data = 0;
 344           b0->current_length = len;
 345
 346           if (checksum_offload_enabled)
 347             virtio_needs_csum (b0, hdr, &l4_proto, &l4_hdr_sz, type);
 348
 349           if (gso_enabled)
 350             fill_gso_buffer_flags (b0, hdr, l4_proto, l4_hdr_sz);
 351
 352           vnet_buffer (b0)->sw_if_index[VLIB_RX] = vif->sw_if_index;
 353           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 354
 355           /* if multisegment packet */
 356           if (PREDICT_FALSE (num_buffers > 1))
 357             {
 358               vlib_buffer_t *pb, *cb;
 359               pb = b0;
 360               b0->total_length_not_including_first_buffer = 0;
 361               while (num_buffers > 1)
 362                 {
 363                   increment_last (last, packed, vring);
 364                   u16 cslot = virtio_get_slot_id (vring, packed, last, mask);
 365                   /* hdr size is 0 after 1st packet in chain buffers */
 366                   u16 clen = virtio_get_len (vring, packed, 0, last, mask);
 367                   u32 cbi = vring->buffers[cslot];
 368                   cb = vlib_get_buffer (vm, cbi);
 369
 370                   /* current buffer */
 371                   cb->current_length = clen;
 372
 373                   /* previous buffer */
 374                   pb->next_buffer = cbi;
 375                   pb->flags |= VLIB_BUFFER_NEXT_PRESENT;
 376
 377                   /* first buffer */
 378                   b0->total_length_not_including_first_buffer += clen;
 379
 380                   pb = cb;
 381                   vring->desc_in_use--;
 382                   num_buffers--;
 383                   n_left--;
 384                 }
 385               len += b0->total_length_not_including_first_buffer;
 386             }
 387
 388           if (type == VIRTIO_IF_TYPE_TUN)
 389             {
 390               switch (b0->data[0] & 0xf0)
 391                 {
 392                 case 0x40:
 393                   next0 = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
 394                   break;
 395                 case 0x60:
 396                   next0 = VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
 397                   break;
 398                 default:
 399                   next0 = VNET_DEVICE_INPUT_NEXT_DROP;
 400                   break;
 401                 }
 402
 403               if (PREDICT_FALSE (vif->per_interface_next_index != ~0))
 404                 next0 = vif->per_interface_next_index;
 405             }
 406           else
 407             {
 408               /* copy feature arc data from template */
 409               b0->current_config_index = bt.current_config_index;
 410               vnet_buffer (b0)->feature_arc_index =
 411                 vnet_buffer (&bt)->feature_arc_index;
 412             }
 413
 414           /* trace */
 415           if (PREDICT_FALSE (n_trace > 0 && vlib_trace_buffer (vm, node, next0, b0,     /* follow_chain */
 416                                                                1)))
 417             {
 418               virtio_input_trace_t *tr;
 419               vlib_set_trace_count (vm, node, --n_trace);
 420               tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
 421               tr->next_index = next0;
 422               tr->hw_if_index = vif->hw_if_index;
 423               tr->len = len;
 424               clib_memcpy_fast (&tr->hdr, hdr, (hdr_sz == 12) ? 12 : 10);
 425             }
 426
 427           /* enqueue buffer */
 428           to_next[0] = bi0;
 429           vring->desc_in_use--;
 430           to_next += 1;
 431           n_left_to_next--;
 432           n_left--;
 433           increment_last (last, packed, vring);
 434
 435           /* only tun interfaces may have different next index */
 436           if (type == VIRTIO_IF_TYPE_TUN)
 437             vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 438                                              n_left_to_next, bi0, next0);
 439
 440           /* next packet */
 441           n_rx_packets++;
 442           n_rx_bytes += len;
 443         }
 444       virtio_device_input_ethernet (vm, node, next_index, vif->sw_if_index,
 445                                     vif->hw_if_index);
 446       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 447     }
 448   vring->last_used_idx = last;
 449
 450   vring->total_packets += n_rx_packets;
 451   vlib_increment_combined_counter (vnm->interface_main.combined_sw_if_counters
 452                                    + VNET_INTERFACE_COUNTER_RX, thread_index,
 453                                    vif->sw_if_index, n_rx_packets,
 454                                    n_rx_bytes);
 455
 456   return n_rx_packets;
 457 }
 458
 459 static_always_inline uword
 460 virtio_device_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 461                             vlib_frame_t * frame, virtio_if_t * vif, u16 qid,
 462                             virtio_if_type_t type)
 463 {
 464   vnet_virtio_vring_t *vring = vec_elt_at_index (vif->rxq_vrings, qid);
 465   const int hdr_sz = vif->virtio_net_hdr_sz;
 466   uword rv;
 467
 468   if (vif->is_packed)
 469     {
 470       if (vif->gso_enabled)
 471         rv =
 472           virtio_device_input_gso_inline (vm, node, frame, vif, vring, type,
 473                                           1, 1, 1);
 474       else if (vif->csum_offload_enabled)
 475         rv =
 476           virtio_device_input_gso_inline (vm, node, frame, vif, vring, type,
 477                                           0, 1, 1);
 478       else
 479         rv =
 480           virtio_device_input_gso_inline (vm, node, frame, vif, vring, type,
 481                                           0, 0, 1);
 482
 483       virtio_refill_vring_packed (vm, vif, type, vring, hdr_sz,
 484                                   node->node_index);
 485     }
 486   else
 487     {
 488       if (vif->gso_enabled)
 489         rv =
 490           virtio_device_input_gso_inline (vm, node, frame, vif, vring, type,
 491                                           1, 1, 0);
 492       else if (vif->csum_offload_enabled)
 493         rv =
 494           virtio_device_input_gso_inline (vm, node, frame, vif, vring, type,
 495                                           0, 1, 0);
 496       else
 497         rv =
 498           virtio_device_input_gso_inline (vm, node, frame, vif, vring, type,
 499                                           0, 0, 0);
 500
 501       virtio_refill_vring_split (vm, vif, type, vring, hdr_sz,
 502                                  node->node_index);
 503     }
 504   return rv;
 505 }
 506
 507 VLIB_NODE_FN (virtio_input_node) (vlib_main_t * vm,
 508                                   vlib_node_runtime_t * node,
 509                                   vlib_frame_t * frame)
 510 {
 511   u32 n_rx = 0;
 512   virtio_main_t *vim = &virtio_main;
 513   vnet_hw_if_rxq_poll_vector_t *p,
 514     *pv = vnet_hw_if_get_rxq_poll_vector (vm, node);
 515
 516   vec_foreach (p, pv)
 517     {
 518       virtio_if_t *vif;
 519       vif = vec_elt_at_index (vim->interfaces, p->dev_instance);
 520       if (vif->flags & VIRTIO_IF_FLAG_ADMIN_UP)
 521         {
 522           if (vif->type == VIRTIO_IF_TYPE_TAP)
 523             n_rx += virtio_device_input_inline (
 524               vm, node, frame, vif, p->queue_id, VIRTIO_IF_TYPE_TAP);
 525           else if (vif->type == VIRTIO_IF_TYPE_PCI)
 526             n_rx += virtio_device_input_inline (
 527               vm, node, frame, vif, p->queue_id, VIRTIO_IF_TYPE_PCI);
 528           else if (vif->type == VIRTIO_IF_TYPE_TUN)
 529             n_rx += virtio_device_input_inline (
 530               vm, node, frame, vif, p->queue_id, VIRTIO_IF_TYPE_TUN);
 531         }
 532     }
 533
 534   return n_rx;
 535 }
 536
 537 VLIB_REGISTER_NODE (virtio_input_node) = {
 538   .name = "virtio-input",
 539   .sibling_of = "device-input",
 540   .format_trace = format_virtio_input_trace,
 541   .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
 542   .type = VLIB_NODE_TYPE_INPUT,
 543   .state = VLIB_NODE_STATE_INTERRUPT,
 544   .n_errors = VIRTIO_INPUT_N_ERROR,
 545   .error_strings = virtio_input_error_strings,
 546 };
 547
 548 /*
 549  * fd.io coding-style-patch-verification: ON
 550  *
 551  * Local Variables:
 552  * eval: (c-set-style "gnu")
 553  * End:
 554  */