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 #include <linux/if_tun.h>
  23 #include <sys/ioctl.h>
  24 #include <sys/eventfd.h>
  25
  26 #include <vlib/vlib.h>
  27 #include <vlib/unix/unix.h>
  28 #include <vnet/ethernet/ethernet.h>
  29 #include <vnet/feature/feature.h>
  30 #include <vnet/interface/rx_queue_funcs.h>
  31 #include <vnet/ip/ip4_packet.h>
  32 #include <vnet/ip/ip6_packet.h>
  33 #include <vnet/udp/udp_packet.h>
  34 #include <vnet/tcp/tcp_packet.h>
  35 #include <vnet/devices/virtio/virtio.h>
  36 #include <vnet/devices/virtio/virtio_inline.h>
  37
  38 static char *virtio_input_error_strings[] = {
  39 #define _(n, s) s,
  40   foreach_virtio_input_error
  41 #undef _
  42 };
  43
  44 typedef struct
  45 {
  46   u32 next_index;
  47   u32 hw_if_index;
  48   u16 ring;
  49   u16 len;
  50   vnet_virtio_net_hdr_v1_t hdr;
  51 } virtio_input_trace_t;
  52
  53 static u8 *
  54 format_virtio_input_trace (u8 * s, va_list * args)
  55 {
  56   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  57   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  58   virtio_input_trace_t *t = va_arg (*args, virtio_input_trace_t *);
  59   u32 indent = format_get_indent (s);
  60
  61   s = format (s, "virtio: hw_if_index %d next-index %d vring %u len %u",
  62               t->hw_if_index, t->next_index, t->ring, t->len);
  63   s = format (s, "\n%Uhdr: flags 0x%02x gso_type 0x%02x hdr_len %u "
  64               "gso_size %u csum_start %u csum_offset %u num_buffers %u",
  65               format_white_space, indent + 2,
  66               t->hdr.flags, t->hdr.gso_type, t->hdr.hdr_len, t->hdr.gso_size,
  67               t->hdr.csum_start, t->hdr.csum_offset, t->hdr.num_buffers);
  68   return s;
  69 }
  70
  71 static_always_inline void
  72 virtio_needs_csum (vlib_buffer_t *b0, vnet_virtio_net_hdr_v1_t *hdr,
  73                    u8 *l4_proto, u8 *l4_hdr_sz, virtio_if_type_t type)
  74 {
  75   if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
  76     {
  77       u16 ethertype = 0, l2hdr_sz = 0;
  78       vnet_buffer_oflags_t oflags = 0;
  79
  80       if (type == VIRTIO_IF_TYPE_TUN)
  81         {
  82           switch (b0->data[0] & 0xf0)
  83             {
  84             case 0x40:
  85               ethertype = ETHERNET_TYPE_IP4;
  86               break;
  87             case 0x60:
  88               ethertype = ETHERNET_TYPE_IP6;
  89               break;
  90             }
  91         }
  92       else
  93         {
  94           ethernet_header_t *eh =
  95             (ethernet_header_t *) vlib_buffer_get_current (b0);
  96           ethertype = clib_net_to_host_u16 (eh->type);
  97           l2hdr_sz = sizeof (ethernet_header_t);
  98
  99           if (ethernet_frame_is_tagged (ethertype))
 100             {
 101               ethernet_vlan_header_t *vlan =
 102                 (ethernet_vlan_header_t *) (eh + 1);
 103
 104               ethertype = clib_net_to_host_u16 (vlan->type);
 105               l2hdr_sz += sizeof (*vlan);
 106               if (ethertype == ETHERNET_TYPE_VLAN)
 107                 {
 108                   vlan++;
 109                   ethertype = clib_net_to_host_u16 (vlan->type);
 110                   l2hdr_sz += sizeof (*vlan);
 111                 }
 112             }
 113         }
 114
 115       vnet_buffer (b0)->l2_hdr_offset = 0;
 116       vnet_buffer (b0)->l3_hdr_offset = l2hdr_sz;
 117
 118       if (PREDICT_TRUE (ethertype == ETHERNET_TYPE_IP4))
 119         {
 120           ip4_header_t *ip4 =
 121             (ip4_header_t *) (vlib_buffer_get_current (b0) + l2hdr_sz);
 122           vnet_buffer (b0)->l4_hdr_offset = l2hdr_sz + ip4_header_bytes (ip4);
 123           *l4_proto = ip4->protocol;
 124           oflags |= VNET_BUFFER_OFFLOAD_F_IP_CKSUM;
 125           b0->flags |=
 126             (VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_L2_HDR_OFFSET_VALID |
 127              VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
 128              VNET_BUFFER_F_L4_HDR_OFFSET_VALID);
 129         }
 130       else if (PREDICT_TRUE (ethertype == ETHERNET_TYPE_IP6))
 131         {
 132           ip6_header_t *ip6 =
 133             (ip6_header_t *) (vlib_buffer_get_current (b0) + l2hdr_sz);
 134           vnet_buffer (b0)->l4_hdr_offset = l2hdr_sz + sizeof (ip6_header_t);
 135           /* FIXME IPv6 EH traversal */
 136           *l4_proto = ip6->protocol;
 137           b0->flags |= (VNET_BUFFER_F_IS_IP6 |
 138                         VNET_BUFFER_F_L2_HDR_OFFSET_VALID
 139                         | VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
 140                         VNET_BUFFER_F_L4_HDR_OFFSET_VALID);
 141         }
 142       if (*l4_proto == IP_PROTOCOL_TCP)
 143         {
 144           oflags |= VNET_BUFFER_OFFLOAD_F_TCP_CKSUM;
 145           tcp_header_t *tcp = (tcp_header_t *) (vlib_buffer_get_current (b0) +
 146                                                 vnet_buffer
 147                                                 (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           udp_header_t *udp = (udp_header_t *) (vlib_buffer_get_current (b0) +
 154                                                 vnet_buffer
 155                                                 (b0)->l4_hdr_offset);
 156           *l4_hdr_sz = sizeof (*udp);
 157         }
 158       if (oflags)
 159         vnet_buffer_offload_flags_set (b0, oflags);
 160     }
 161 }
 162
 163 static_always_inline void
 164 fill_gso_buffer_flags (vlib_buffer_t *b0, vnet_virtio_net_hdr_v1_t *hdr,
 165                        u8 l4_proto, u8 l4_hdr_sz)
 166 {
 167   if (hdr->gso_type == VIRTIO_NET_HDR_GSO_TCPV4)
 168     {
 169       ASSERT (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM);
 170       vnet_buffer2 (b0)->gso_size = hdr->gso_size;
 171       vnet_buffer2 (b0)->gso_l4_hdr_sz = l4_hdr_sz;
 172       b0->flags |= VNET_BUFFER_F_GSO | VNET_BUFFER_F_IS_IP4;
 173     }
 174   if (hdr->gso_type == VIRTIO_NET_HDR_GSO_TCPV6)
 175     {
 176       ASSERT (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM);
 177       vnet_buffer2 (b0)->gso_size = hdr->gso_size;
 178       vnet_buffer2 (b0)->gso_l4_hdr_sz = l4_hdr_sz;
 179       b0->flags |= VNET_BUFFER_F_GSO | VNET_BUFFER_F_IS_IP6;
 180     }
 181 }
 182
 183 static_always_inline u16
 184 virtio_n_left_to_process (vnet_virtio_vring_t *vring, const int packed)
 185 {
 186   if (packed)
 187     return vring->desc_in_use;
 188   else
 189     return vring->used->idx - vring->last_used_idx;
 190 }
 191
 192 static_always_inline u16
 193 virtio_get_slot_id (vnet_virtio_vring_t *vring, const int packed, u16 last,
 194                     u16 mask)
 195 {
 196   if (packed)
 197     return vring->packed_desc[last].id;
 198   else
 199     return vring->used->ring[last & mask].id;
 200 }
 201
 202 static_always_inline u16
 203 virtio_get_len (vnet_virtio_vring_t *vring, const int packed, const int hdr_sz,
 204                 u16 last, u16 mask)
 205 {
 206   if (packed)
 207     return vring->packed_desc[last].len - hdr_sz;
 208   else
 209     return vring->used->ring[last & mask].len - hdr_sz;
 210 }
 211
 212 #define increment_last(last, packed, vring)                                   \
 213   do                                                                          \
 214     {                                                                         \
 215       last++;                                                                 \
 216       if (packed && last >= vring->queue_size)                                \
 217         {                                                                     \
 218           last = 0;                                                           \
 219           vring->used_wrap_counter ^= 1;                                      \
 220         }                                                                     \
 221     }                                                                         \
 222   while (0)
 223
 224 static_always_inline uword
 225 virtio_device_input_gso_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
 226                                 vlib_frame_t *frame, virtio_if_t *vif,
 227                                 vnet_virtio_vring_t *vring,
 228                                 virtio_if_type_t type, int gso_enabled,
 229                                 int checksum_offload_enabled, int packed)
 230 {
 231   vnet_main_t *vnm = vnet_get_main ();
 232   u32 thread_index = vm->thread_index;
 233   uword n_trace = vlib_get_trace_count (vm, node);
 234   u32 next_index;
 235   const int hdr_sz = vif->virtio_net_hdr_sz;
 236   u32 *to_next = 0;
 237   u32 n_rx_packets = 0;
 238   u32 n_rx_bytes = 0;
 239   u16 mask = vring->queue_size - 1;
 240   u16 last = vring->last_used_idx;
 241   u16 n_left = virtio_n_left_to_process (vring, packed);
 242   vlib_buffer_t bt = {};
 243
 244   if (n_left == 0)
 245     return 0;
 246
 247   if (type == VIRTIO_IF_TYPE_TUN)
 248     {
 249       next_index = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
 250     }
 251   else
 252     {
 253       next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
 254       if (PREDICT_FALSE (vif->per_interface_next_index != ~0))
 255         next_index = vif->per_interface_next_index;
 256
 257       /* only for l2, redirect if feature path enabled */
 258       vnet_feature_start_device_input_x1 (vif->sw_if_index, &next_index, &bt);
 259     }
 260
 261   while (n_left)
 262     {
 263       u32 n_left_to_next;
 264       u32 next0 = next_index;
 265
 266       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 267
 268       while (n_left && n_left_to_next)
 269         {
 270           if (packed)
 271             {
 272               vnet_virtio_vring_packed_desc_t *d = &vring->packed_desc[last];
 273               u16 flags = d->flags;
 274               if ((flags & VRING_DESC_F_AVAIL) !=
 275                   (vring->used_wrap_counter << 7)
 276                   || (flags & VRING_DESC_F_USED) !=
 277                   (vring->used_wrap_counter << 15))
 278                 {
 279                   n_left = 0;
 280                   break;
 281                 }
 282             }
 283           u8 l4_proto = 0, l4_hdr_sz = 0;
 284           u16 num_buffers = 1;
 285           vnet_virtio_net_hdr_v1_t *hdr;
 286           u16 slot = virtio_get_slot_id (vring, packed, last, mask);
 287           u16 len = virtio_get_len (vring, packed, hdr_sz, last, mask);
 288           u32 bi0 = vring->buffers[slot];
 289           vlib_buffer_t *b0 = vlib_get_buffer (vm, bi0);
 290           hdr = vlib_buffer_get_current (b0);
 291           if (hdr_sz == sizeof (vnet_virtio_net_hdr_v1_t))
 292             num_buffers = hdr->num_buffers;
 293
 294           b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
 295           b0->current_data = 0;
 296           b0->current_length = len;
 297
 298           if (checksum_offload_enabled)
 299             virtio_needs_csum (b0, hdr, &l4_proto, &l4_hdr_sz, type);
 300
 301           if (gso_enabled)
 302             fill_gso_buffer_flags (b0, hdr, l4_proto, l4_hdr_sz);
 303
 304           vnet_buffer (b0)->sw_if_index[VLIB_RX] = vif->sw_if_index;
 305           vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 306
 307           /* if multisegment packet */
 308           if (PREDICT_FALSE (num_buffers > 1))
 309             {
 310               vlib_buffer_t *pb, *cb;
 311               pb = b0;
 312               b0->total_length_not_including_first_buffer = 0;
 313               while (num_buffers > 1)
 314                 {
 315                   increment_last (last, packed, vring);
 316                   u16 cslot = virtio_get_slot_id (vring, packed, last, mask);
 317                   /* hdr size is 0 after 1st packet in chain buffers */
 318                   u16 clen = virtio_get_len (vring, packed, 0, last, mask);
 319                   u32 cbi = vring->buffers[cslot];
 320                   cb = vlib_get_buffer (vm, cbi);
 321
 322                   /* current buffer */
 323                   cb->current_length = clen;
 324
 325                   /* previous buffer */
 326                   pb->next_buffer = cbi;
 327                   pb->flags |= VLIB_BUFFER_NEXT_PRESENT;
 328
 329                   /* first buffer */
 330                   b0->total_length_not_including_first_buffer += clen;
 331
 332                   pb = cb;
 333                   vring->desc_in_use--;
 334                   num_buffers--;
 335                   n_left--;
 336                 }
 337               len += b0->total_length_not_including_first_buffer;
 338             }
 339
 340           if (type == VIRTIO_IF_TYPE_TUN)
 341             {
 342               switch (b0->data[0] & 0xf0)
 343                 {
 344                 case 0x40:
 345                   next0 = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
 346                   break;
 347                 case 0x60:
 348                   next0 = VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
 349                   break;
 350                 default:
 351                   next0 = VNET_DEVICE_INPUT_NEXT_DROP;
 352                   break;
 353                 }
 354
 355               if (PREDICT_FALSE (vif->per_interface_next_index != ~0))
 356                 next0 = vif->per_interface_next_index;
 357             }
 358           else
 359             {
 360               /* copy feature arc data from template */
 361               b0->current_config_index = bt.current_config_index;
 362               vnet_buffer (b0)->feature_arc_index =
 363                 vnet_buffer (&bt)->feature_arc_index;
 364             }
 365
 366           /* trace */
 367           if (PREDICT_FALSE (n_trace > 0 && vlib_trace_buffer (vm, node, next0, b0,     /* follow_chain */
 368                                                                1)))
 369             {
 370               virtio_input_trace_t *tr;
 371               vlib_set_trace_count (vm, node, --n_trace);
 372               tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
 373               tr->next_index = next0;
 374               tr->hw_if_index = vif->hw_if_index;
 375               tr->len = len;
 376               clib_memcpy_fast (&tr->hdr, hdr, (hdr_sz == 12) ? 12 : 10);
 377             }
 378
 379           /* enqueue buffer */
 380           to_next[0] = bi0;
 381           vring->desc_in_use--;
 382           to_next += 1;
 383           n_left_to_next--;
 384           n_left--;
 385           increment_last (last, packed, vring);
 386
 387           /* only tun interfaces may have different next index */
 388           if (type == VIRTIO_IF_TYPE_TUN)
 389             vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 390                                              n_left_to_next, bi0, next0);
 391
 392           /* next packet */
 393           n_rx_packets++;
 394           n_rx_bytes += len;
 395         }
 396       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 397     }
 398   vring->last_used_idx = last;
 399
 400   vlib_increment_combined_counter (vnm->interface_main.combined_sw_if_counters
 401                                    + VNET_INTERFACE_COUNTER_RX, thread_index,
 402                                    vif->sw_if_index, n_rx_packets,
 403                                    n_rx_bytes);
 404
 405   return n_rx_packets;
 406 }
 407
 408 static_always_inline uword
 409 virtio_device_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 410                             vlib_frame_t * frame, virtio_if_t * vif, u16 qid,
 411                             virtio_if_type_t type)
 412 {
 413   vnet_virtio_vring_t *vring = vec_elt_at_index (vif->rxq_vrings, qid);
 414   const int hdr_sz = vif->virtio_net_hdr_sz;
 415   uword rv;
 416
 417   if (vif->is_packed)
 418     {
 419       if (vif->gso_enabled)
 420         rv =
 421           virtio_device_input_gso_inline (vm, node, frame, vif, vring, type,
 422                                           1, 1, 1);
 423       else if (vif->csum_offload_enabled)
 424         rv =
 425           virtio_device_input_gso_inline (vm, node, frame, vif, vring, type,
 426                                           0, 1, 1);
 427       else
 428         rv =
 429           virtio_device_input_gso_inline (vm, node, frame, vif, vring, type,
 430                                           0, 0, 1);
 431
 432       virtio_refill_vring_packed (vm, vif, type, vring, hdr_sz,
 433                                   node->node_index);
 434     }
 435   else
 436     {
 437       if (vif->gso_enabled)
 438         rv =
 439           virtio_device_input_gso_inline (vm, node, frame, vif, vring, type,
 440                                           1, 1, 0);
 441       else if (vif->csum_offload_enabled)
 442         rv =
 443           virtio_device_input_gso_inline (vm, node, frame, vif, vring, type,
 444                                           0, 1, 0);
 445       else
 446         rv =
 447           virtio_device_input_gso_inline (vm, node, frame, vif, vring, type,
 448                                           0, 0, 0);
 449
 450       virtio_refill_vring_split (vm, vif, type, vring, hdr_sz,
 451                                  node->node_index);
 452     }
 453   return rv;
 454 }
 455
 456 VLIB_NODE_FN (virtio_input_node) (vlib_main_t * vm,
 457                                   vlib_node_runtime_t * node,
 458                                   vlib_frame_t * frame)
 459 {
 460   u32 n_rx = 0;
 461   virtio_main_t *vim = &virtio_main;
 462   vnet_hw_if_rxq_poll_vector_t *p,
 463     *pv = vnet_hw_if_get_rxq_poll_vector (vm, node);
 464
 465   vec_foreach (p, pv)
 466     {
 467       virtio_if_t *vif;
 468       vif = vec_elt_at_index (vim->interfaces, p->dev_instance);
 469       if (vif->flags & VIRTIO_IF_FLAG_ADMIN_UP)
 470         {
 471           if (vif->type == VIRTIO_IF_TYPE_TAP)
 472             n_rx += virtio_device_input_inline (
 473               vm, node, frame, vif, p->queue_id, VIRTIO_IF_TYPE_TAP);
 474           else if (vif->type == VIRTIO_IF_TYPE_PCI)
 475             n_rx += virtio_device_input_inline (
 476               vm, node, frame, vif, p->queue_id, VIRTIO_IF_TYPE_PCI);
 477           else if (vif->type == VIRTIO_IF_TYPE_TUN)
 478             n_rx += virtio_device_input_inline (
 479               vm, node, frame, vif, p->queue_id, VIRTIO_IF_TYPE_TUN);
 480         }
 481     }
 482
 483   return n_rx;
 484 }
 485
 486 /* *INDENT-OFF* */
 487 VLIB_REGISTER_NODE (virtio_input_node) = {
 488   .name = "virtio-input",
 489   .sibling_of = "device-input",
 490   .format_trace = format_virtio_input_trace,
 491   .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
 492   .type = VLIB_NODE_TYPE_INPUT,
 493   .state = VLIB_NODE_STATE_INTERRUPT,
 494   .n_errors = VIRTIO_INPUT_N_ERROR,
 495   .error_strings = virtio_input_error_strings,
 496 };
 497 /* *INDENT-ON* */
 498
 499 /*
 500  * fd.io coding-style-patch-verification: ON
 501  *
 502  * Local Variables:
 503  * eval: (c-set-style "gnu")
 504  * End:
 505  */