src/vnet/devices/af_packet/node.c

   1 /*
   2  *------------------------------------------------------------------
   3  * af_packet.c - linux kernel packet interface
   4  *
   5  * Copyright (c) 2016 Cisco and/or its affiliates.
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at:
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  *------------------------------------------------------------------
  18  */
  19
  20 #include <linux/if_packet.h>
  21
  22 #include <vlib/vlib.h>
  23 #include <vlib/unix/unix.h>
  24 #include <vnet/ip/ip.h>
  25 #include <vnet/ethernet/ethernet.h>
  26 #include <vnet/interface/rx_queue_funcs.h>
  27 #include <vnet/feature/feature.h>
  28 #include <vnet/ethernet/packet.h>
  29
  30 #include <vnet/devices/af_packet/af_packet.h>
  31 #include <vnet/devices/virtio/virtio_std.h>
  32
  33 #define foreach_af_packet_input_error \
  34   _(PARTIAL_PKT, "partial packet")
  35
  36 typedef enum
  37 {
  38 #define _(f,s) AF_PACKET_INPUT_ERROR_##f,
  39   foreach_af_packet_input_error
  40 #undef _
  41     AF_PACKET_INPUT_N_ERROR,
  42 } af_packet_input_error_t;
  43
  44 static char *af_packet_input_error_strings[] = {
  45 #define _(n,s) s,
  46   foreach_af_packet_input_error
  47 #undef _
  48 };
  49
  50 typedef struct
  51 {
  52   u32 next_index;
  53   u32 hw_if_index;
  54   int block;
  55   u32 pkt_num;
  56   void *block_start;
  57   block_desc_t bd;
  58   tpacket3_hdr_t tph;
  59   vnet_virtio_net_hdr_t vnet_hdr;
  60 } af_packet_input_trace_t;
  61
  62 static u8 *
  63 format_af_packet_input_trace (u8 * s, va_list * args)
  64 {
  65   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  66   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  67   af_packet_input_trace_t *t = va_arg (*args, af_packet_input_trace_t *);
  68   u32 indent = format_get_indent (s);
  69
  70   s = format (s, "af_packet: hw_if_index %d next-index %d",
  71               t->hw_if_index, t->next_index);
  72
  73   s = format (
  74     s, "\n%Ublock %u:\n%Uaddress %p version %u seq_num %lu pkt_num %u",
  75     format_white_space, indent + 2, t->block, format_white_space, indent + 4,
  76     t->block_start, t->bd.version, t->bd.hdr.bh1.seq_num, t->pkt_num);
  77   s =
  78     format (s,
  79             "\n%Utpacket3_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
  80             "\n%Usec 0x%x nsec 0x%x vlan %U"
  81 #ifdef TP_STATUS_VLAN_TPID_VALID
  82             " vlan_tpid %u"
  83 #endif
  84             ,
  85             format_white_space, indent + 2, format_white_space, indent + 4,
  86             t->tph.tp_status, t->tph.tp_len, t->tph.tp_snaplen, t->tph.tp_mac,
  87             t->tph.tp_net, format_white_space, indent + 4, t->tph.tp_sec,
  88             t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.hv1.tp_vlan_tci
  89 #ifdef TP_STATUS_VLAN_TPID_VALID
  90             ,
  91             t->tph.hv1.tp_vlan_tpid
  92 #endif
  93     );
  94
  95   s = format (s,
  96               "\n%Uvnet-hdr:\n%Uflags 0x%02x gso_type 0x%02x hdr_len %u"
  97               "\n%Ugso_size %u csum_start %u csum_offset %u",
  98               format_white_space, indent + 2, format_white_space, indent + 4,
  99               t->vnet_hdr.flags, t->vnet_hdr.gso_type, t->vnet_hdr.hdr_len,
 100               format_white_space, indent + 4, t->vnet_hdr.gso_size,
 101               t->vnet_hdr.csum_start, t->vnet_hdr.csum_offset);
 102   return s;
 103 }
 104
 105 always_inline void
 106 buffer_add_to_chain (vlib_buffer_t *b, vlib_buffer_t *first_b,
 107                      vlib_buffer_t *prev_b, u32 bi)
 108 {
 109   /* update first buffer */
 110   first_b->total_length_not_including_first_buffer += b->current_length;
 111
 112   /* update previous buffer */
 113   prev_b->next_buffer = bi;
 114   prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 115
 116   /* update current buffer */
 117   b->next_buffer = ~0;
 118 }
 119
 120 static_always_inline void
 121 fill_gso_offload (vlib_buffer_t *b, u32 gso_size, u8 l4_hdr_sz)
 122 {
 123   b->flags |= VNET_BUFFER_F_GSO;
 124   vnet_buffer2 (b)->gso_size = gso_size;
 125   vnet_buffer2 (b)->gso_l4_hdr_sz = l4_hdr_sz;
 126 }
 127
 128 static_always_inline void
 129 fill_cksum_offload (vlib_buffer_t *b, u8 *l4_hdr_sz, u8 is_ip)
 130 {
 131   vnet_buffer_oflags_t oflags = 0;
 132   u16 l2hdr_sz = 0;
 133   u16 ethertype = 0;
 134   u8 l4_proto = 0;
 135
 136   if (is_ip)
 137     {
 138       switch (b->data[0] & 0xf0)
 139         {
 140         case 0x40:
 141           ethertype = ETHERNET_TYPE_IP4;
 142           break;
 143         case 0x60:
 144           ethertype = ETHERNET_TYPE_IP6;
 145           break;
 146         }
 147     }
 148   else
 149     {
 150       ethernet_header_t *eth = vlib_buffer_get_current (b);
 151       ethertype = clib_net_to_host_u16 (eth->type);
 152       l2hdr_sz = sizeof (ethernet_header_t);
 153       if (ethernet_frame_is_tagged (ethertype))
 154         {
 155           ethernet_vlan_header_t *vlan = (ethernet_vlan_header_t *) (eth + 1);
 156
 157           ethertype = clib_net_to_host_u16 (vlan->type);
 158           l2hdr_sz += sizeof (*vlan);
 159           if (ethertype == ETHERNET_TYPE_VLAN)
 160             {
 161               vlan++;
 162               ethertype = clib_net_to_host_u16 (vlan->type);
 163               l2hdr_sz += sizeof (*vlan);
 164             }
 165         }
 166     }
 167
 168   vnet_buffer (b)->l2_hdr_offset = 0;
 169   vnet_buffer (b)->l3_hdr_offset = l2hdr_sz;
 170
 171   if (ethertype == ETHERNET_TYPE_IP4)
 172     {
 173       ip4_header_t *ip4 = (vlib_buffer_get_current (b) + l2hdr_sz);
 174       vnet_buffer (b)->l4_hdr_offset = l2hdr_sz + ip4_header_bytes (ip4);
 175       b->flags |= (VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_L2_HDR_OFFSET_VALID |
 176                    VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
 177                    VNET_BUFFER_F_L4_HDR_OFFSET_VALID);
 178
 179       l4_proto = ip4->protocol;
 180     }
 181   else if (ethertype == ETHERNET_TYPE_IP6)
 182     {
 183       ip6_header_t *ip6 = (vlib_buffer_get_current (b) + l2hdr_sz);
 184       b->flags |= (VNET_BUFFER_F_IS_IP6 | VNET_BUFFER_F_L2_HDR_OFFSET_VALID |
 185                    VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
 186                    VNET_BUFFER_F_L4_HDR_OFFSET_VALID);
 187       u16 ip6_hdr_len = sizeof (ip6_header_t);
 188
 189       if (ip6_ext_hdr (ip6->protocol))
 190         {
 191           ip6_ext_header_t *p = (void *) (ip6 + 1);
 192           ip6_hdr_len += ip6_ext_header_len (p);
 193           while (ip6_ext_hdr (p->next_hdr))
 194             {
 195               ip6_hdr_len += ip6_ext_header_len (p);
 196               p = ip6_ext_next_header (p);
 197             }
 198           l4_proto = p->next_hdr;
 199         }
 200       else
 201         l4_proto = ip6->protocol;
 202       vnet_buffer (b)->l4_hdr_offset = l2hdr_sz + ip6_hdr_len;
 203     }
 204
 205   if (l4_proto == IP_PROTOCOL_TCP)
 206     {
 207       oflags |= VNET_BUFFER_OFFLOAD_F_TCP_CKSUM;
 208       tcp_header_t *tcp = (tcp_header_t *) (vlib_buffer_get_current (b) +
 209                                             vnet_buffer (b)->l4_hdr_offset);
 210       *l4_hdr_sz = tcp_header_bytes (tcp);
 211     }
 212   else if (l4_proto == IP_PROTOCOL_UDP)
 213     {
 214       oflags |= VNET_BUFFER_OFFLOAD_F_UDP_CKSUM;
 215       *l4_hdr_sz = sizeof (udp_header_t);
 216     }
 217
 218   if (oflags)
 219     vnet_buffer_offload_flags_set (b, oflags);
 220 }
 221
 222 always_inline uword
 223 af_packet_device_input_fn (vlib_main_t *vm, vlib_node_runtime_t *node,
 224                            vlib_frame_t *frame, af_packet_if_t *apif,
 225                            u8 is_cksum_gso_enabled)
 226 {
 227   af_packet_main_t *apm = &af_packet_main;
 228   tpacket3_hdr_t *tph;
 229   u32 next_index;
 230   u32 n_free_bufs;
 231   u32 n_rx_packets = 0;
 232   u32 n_rx_bytes = 0;
 233   u32 *to_next = 0;
 234   u32 block = apif->next_rx_block;
 235   u32 block_nr = apif->rx_req->tp_block_nr;
 236   u8 *block_start = 0;
 237   uword n_trace = vlib_get_trace_count (vm, node);
 238   u32 thread_index = vm->thread_index;
 239   u32 n_buffer_bytes = vlib_buffer_get_default_data_size (vm);
 240   u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
 241   u32 num_pkts = 0;
 242   u32 rx_frame_offset = 0;
 243   block_desc_t *bd = 0;
 244   vlib_buffer_t bt;
 245   u8 is_ip = (apif->mode == AF_PACKET_IF_MODE_IP);
 246
 247   if (is_ip)
 248     next_index = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
 249   else
 250     {
 251       next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
 252       if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
 253         next_index = apif->per_interface_next_index;
 254
 255       /* redirect if feature path enabled */
 256       vnet_feature_start_device_input_x1 (apif->sw_if_index, &next_index, &bt);
 257     }
 258
 259   while ((((block_desc_t *) (block_start = apif->rx_ring[block]))
 260             ->hdr.bh1.block_status &
 261           TP_STATUS_USER) != 0)
 262     {
 263       u32 n_required = 0;
 264
 265       if (PREDICT_FALSE (num_pkts == 0))
 266         {
 267           bd = (block_desc_t *) block_start;
 268           num_pkts = bd->hdr.bh1.num_pkts;
 269           rx_frame_offset = sizeof (block_desc_t);
 270         }
 271
 272       n_required = clib_max (num_pkts, VLIB_FRAME_SIZE);
 273       n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
 274       if (PREDICT_FALSE (n_free_bufs < n_required))
 275         {
 276           vec_validate (apm->rx_buffers[thread_index],
 277                         n_required + n_free_bufs - 1);
 278           n_free_bufs += vlib_buffer_alloc (
 279             vm, &apm->rx_buffers[thread_index][n_free_bufs], n_required);
 280           _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
 281         }
 282
 283       while (num_pkts && (n_free_bufs > min_bufs))
 284         {
 285           u32 next0 = next_index;
 286           u32 n_left_to_next;
 287
 288           vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 289
 290           while (num_pkts && n_left_to_next && (n_free_bufs > min_bufs))
 291             {
 292               tph = (tpacket3_hdr_t *) (block_start + rx_frame_offset);
 293
 294               if (num_pkts > 1)
 295                 CLIB_PREFETCH (block_start + rx_frame_offset +
 296                                  tph->tp_next_offset,
 297                                2 * CLIB_CACHE_LINE_BYTES, LOAD);
 298
 299               vlib_buffer_t *b0 = 0, *first_b0 = 0, *prev_b0 = 0;
 300               vnet_virtio_net_hdr_t *vnet_hdr = 0;
 301               u32 data_len = tph->tp_snaplen;
 302               u32 offset = 0;
 303               u32 bi0 = ~0, first_bi0 = ~0;
 304               u8 l4_hdr_sz = 0;
 305
 306               if (is_cksum_gso_enabled)
 307                 vnet_hdr =
 308                   (vnet_virtio_net_hdr_t *) ((u8 *) tph + tph->tp_mac -
 309                                              sizeof (vnet_virtio_net_hdr_t));
 310
 311               if (PREDICT_FALSE (((data_len / n_buffer_bytes) + 1) >
 312                                  vec_len (apm->rx_buffers[thread_index])))
 313                 {
 314                   vec_validate (apm->rx_buffers[thread_index],
 315                                 VLIB_FRAME_SIZE + n_free_bufs - 1);
 316                   n_free_bufs += vlib_buffer_alloc (
 317                     vm, &apm->rx_buffers[thread_index][n_free_bufs],
 318                     VLIB_FRAME_SIZE);
 319                   _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
 320                 }
 321
 322               while (data_len)
 323                 {
 324                   /* grab free buffer */
 325                   u32 last_empty_buffer =
 326                     vec_len (apm->rx_buffers[thread_index]) - 1;
 327                   bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
 328                   _vec_len (apm->rx_buffers[thread_index]) = last_empty_buffer;
 329                   n_free_bufs--;
 330
 331                   /* copy data */
 332                   u32 bytes_to_copy =
 333                     data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
 334                   u32 vlan_len = 0;
 335                   u32 bytes_copied = 0;
 336
 337                   b0 = vlib_get_buffer (vm, bi0);
 338                   b0->current_data = 0;
 339
 340                   /* Kernel removes VLAN headers, so reconstruct VLAN */
 341                   if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
 342                     {
 343                       if (PREDICT_TRUE (offset == 0))
 344                         {
 345                           clib_memcpy_fast (vlib_buffer_get_current (b0),
 346                                             (u8 *) tph + tph->tp_mac,
 347                                             sizeof (ethernet_header_t));
 348                           ethernet_header_t *eth =
 349                             vlib_buffer_get_current (b0);
 350                           ethernet_vlan_header_t *vlan =
 351                             (ethernet_vlan_header_t *) (eth + 1);
 352                           vlan->priority_cfi_and_id =
 353                             clib_host_to_net_u16 (tph->hv1.tp_vlan_tci);
 354                           vlan->type = eth->type;
 355                           eth->type =
 356                             clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
 357                           vlan_len = sizeof (ethernet_vlan_header_t);
 358                           bytes_copied = sizeof (ethernet_header_t);
 359                         }
 360                     }
 361                   clib_memcpy_fast (((u8 *) vlib_buffer_get_current (b0)) +
 362                                       bytes_copied + vlan_len,
 363                                     (u8 *) tph + tph->tp_mac + offset +
 364                                       bytes_copied,
 365                                     (bytes_to_copy - bytes_copied));
 366
 367                   /* fill buffer header */
 368                   b0->current_length = bytes_to_copy + vlan_len;
 369
 370                   if (offset == 0)
 371                     {
 372                       b0->total_length_not_including_first_buffer = 0;
 373                       b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
 374                       vnet_buffer (b0)->sw_if_index[VLIB_RX] =
 375                         apif->sw_if_index;
 376                       vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~0;
 377                       first_b0 = b0;
 378                       first_bi0 = bi0;
 379                       if (is_cksum_gso_enabled)
 380                         {
 381                           if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
 382                             fill_cksum_offload (first_b0, &l4_hdr_sz, is_ip);
 383                           if (vnet_hdr->gso_type & (VIRTIO_NET_HDR_GSO_TCPV4 |
 384                                                     VIRTIO_NET_HDR_GSO_TCPV6))
 385                             fill_gso_offload (first_b0, vnet_hdr->gso_size,
 386                                               l4_hdr_sz);
 387                         }
 388                     }
 389                   else
 390                     buffer_add_to_chain (b0, first_b0, prev_b0, bi0);
 391
 392                   prev_b0 = b0;
 393                   offset += bytes_to_copy;
 394                   data_len -= bytes_to_copy;
 395                 }
 396               n_rx_packets++;
 397               n_rx_bytes += tph->tp_snaplen;
 398               to_next[0] = first_bi0;
 399               to_next += 1;
 400               n_left_to_next--;
 401
 402               /* drop partial packets */
 403               if (PREDICT_FALSE (tph->tp_len != tph->tp_snaplen))
 404                 {
 405                   next0 = VNET_DEVICE_INPUT_NEXT_DROP;
 406                   first_b0->error =
 407                     node->errors[AF_PACKET_INPUT_ERROR_PARTIAL_PKT];
 408                 }
 409               else
 410                 {
 411                   if (PREDICT_FALSE (apif->mode == AF_PACKET_IF_MODE_IP))
 412                     {
 413                       switch (first_b0->data[0] & 0xf0)
 414                         {
 415                         case 0x40:
 416                           next0 = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
 417                           break;
 418                         case 0x60:
 419                           next0 = VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
 420                           break;
 421                         default:
 422                           next0 = VNET_DEVICE_INPUT_NEXT_DROP;
 423                           break;
 424                         }
 425                       if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
 426                         next0 = apif->per_interface_next_index;
 427                     }
 428                   else
 429                     {
 430                       /* copy feature arc data from template */
 431                       first_b0->current_config_index = bt.current_config_index;
 432                       vnet_buffer (first_b0)->feature_arc_index =
 433                         vnet_buffer (&bt)->feature_arc_index;
 434                     }
 435                 }
 436
 437               /* trace */
 438               if (PREDICT_FALSE (n_trace > 0 &&
 439                                  vlib_trace_buffer (vm, node, next0, first_b0,
 440                                                     /* follow_chain */ 0)))
 441                 {
 442                   af_packet_input_trace_t *tr;
 443                   vlib_set_trace_count (vm, node, --n_trace);
 444                   tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
 445                   tr->next_index = next0;
 446                   tr->hw_if_index = apif->hw_if_index;
 447                   tr->block = block;
 448                   tr->block_start = bd;
 449                   tr->pkt_num = bd->hdr.bh1.num_pkts - num_pkts;
 450                   clib_memcpy_fast (&tr->bd, bd, sizeof (block_desc_t));
 451                   clib_memcpy_fast (&tr->tph, tph, sizeof (tpacket3_hdr_t));
 452                   if (is_cksum_gso_enabled)
 453                     clib_memcpy_fast (&tr->vnet_hdr, vnet_hdr,
 454                                       sizeof (vnet_virtio_net_hdr_t));
 455                   else
 456                     clib_memset_u8 (&tr->vnet_hdr, 0,
 457                                     sizeof (vnet_virtio_net_hdr_t));
 458                 }
 459
 460               /* enque and take next packet */
 461               vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 462                                                n_left_to_next, first_bi0,
 463                                                next0);
 464
 465               /* next packet */
 466               num_pkts--;
 467               rx_frame_offset += tph->tp_next_offset;
 468             }
 469
 470           vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 471         }
 472
 473       if (PREDICT_TRUE (num_pkts == 0))
 474         {
 475           bd->hdr.bh1.block_status = TP_STATUS_KERNEL;
 476           block = (block + 1) % block_nr;
 477         }
 478     }
 479
 480   apif->next_rx_block = block;
 481   vlib_increment_combined_counter
 482     (vnet_get_main ()->interface_main.combined_sw_if_counters
 483      + VNET_INTERFACE_COUNTER_RX,
 484      vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes);
 485
 486   vnet_device_increment_rx_packets (thread_index, n_rx_packets);
 487   return n_rx_packets;
 488 }
 489
 490 VLIB_NODE_FN (af_packet_input_node) (vlib_main_t * vm,
 491                                      vlib_node_runtime_t * node,
 492                                      vlib_frame_t * frame)
 493 {
 494   u32 n_rx_packets = 0;
 495   af_packet_main_t *apm = &af_packet_main;
 496   vnet_hw_if_rxq_poll_vector_t *pv;
 497   pv = vnet_hw_if_get_rxq_poll_vector (vm, node);
 498   for (int i = 0; i < vec_len (pv); i++)
 499     {
 500       af_packet_if_t *apif;
 501       apif = vec_elt_at_index (apm->interfaces, pv[i].dev_instance);
 502       if (apif->is_admin_up)
 503         {
 504           if (apif->is_cksum_gso_enabled)
 505             n_rx_packets +=
 506               af_packet_device_input_fn (vm, node, frame, apif, 1);
 507           else
 508             n_rx_packets +=
 509               af_packet_device_input_fn (vm, node, frame, apif, 0);
 510         }
 511     }
 512   return n_rx_packets;
 513 }
 514
 515 VLIB_REGISTER_NODE (af_packet_input_node) = {
 516   .name = "af-packet-input",
 517   .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
 518   .sibling_of = "device-input",
 519   .format_trace = format_af_packet_input_trace,
 520   .type = VLIB_NODE_TYPE_INPUT,
 521   .state = VLIB_NODE_STATE_INTERRUPT,
 522   .n_errors = AF_PACKET_INPUT_N_ERROR,
 523   .error_strings = af_packet_input_error_strings,
 524 };
 525
 526
 527 /*
 528  * fd.io coding-style-patch-verification: ON
 529  *
 530  * Local Variables:
 531  * eval: (c-set-style "gnu")
 532  * End:
 533  */