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
  32 #define foreach_af_packet_input_error \
  33   _(PARTIAL_PKT, "partial packet")
  34
  35 typedef enum
  36 {
  37 #define _(f,s) AF_PACKET_INPUT_ERROR_##f,
  38   foreach_af_packet_input_error
  39 #undef _
  40     AF_PACKET_INPUT_N_ERROR,
  41 } af_packet_input_error_t;
  42
  43 static char *af_packet_input_error_strings[] = {
  44 #define _(n,s) s,
  45   foreach_af_packet_input_error
  46 #undef _
  47 };
  48
  49 typedef struct
  50 {
  51   u32 next_index;
  52   u32 hw_if_index;
  53   int block;
  54   struct tpacket2_hdr tph;
  55 } af_packet_input_trace_t;
  56
  57 static u8 *
  58 format_af_packet_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   af_packet_input_trace_t *t = va_arg (*args, af_packet_input_trace_t *);
  63   u32 indent = format_get_indent (s);
  64
  65   s = format (s, "af_packet: hw_if_index %d next-index %d",
  66               t->hw_if_index, t->next_index);
  67
  68   s =
  69     format (s,
  70             "\n%Utpacket2_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
  71             "\n%Usec 0x%x nsec 0x%x vlan %U"
  72 #ifdef TP_STATUS_VLAN_TPID_VALID
  73             " vlan_tpid %u"
  74 #endif
  75             ,
  76             format_white_space, indent + 2,
  77             format_white_space, indent + 4,
  78             t->tph.tp_status,
  79             t->tph.tp_len,
  80             t->tph.tp_snaplen,
  81             t->tph.tp_mac,
  82             t->tph.tp_net,
  83             format_white_space, indent + 4,
  84             t->tph.tp_sec,
  85             t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.tp_vlan_tci
  86 #ifdef TP_STATUS_VLAN_TPID_VALID
  87             , t->tph.tp_vlan_tpid
  88 #endif
  89     );
  90   return s;
  91 }
  92
  93 always_inline void
  94 buffer_add_to_chain (vlib_main_t * vm, u32 bi, u32 first_bi, u32 prev_bi)
  95 {
  96   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
  97   vlib_buffer_t *first_b = vlib_get_buffer (vm, first_bi);
  98   vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_bi);
  99
 100   /* update first buffer */
 101   first_b->total_length_not_including_first_buffer += b->current_length;
 102
 103   /* update previous buffer */
 104   prev_b->next_buffer = bi;
 105   prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 106
 107   /* update current buffer */
 108   b->next_buffer = 0;
 109 }
 110
 111 static_always_inline void
 112 fill_gso_buffer_flags (vlib_buffer_t *b, u32 gso_size, u8 l4_hdr_sz)
 113 {
 114   b->flags |= VNET_BUFFER_F_GSO;
 115   vnet_buffer2 (b)->gso_size = gso_size;
 116   vnet_buffer2 (b)->gso_l4_hdr_sz = l4_hdr_sz;
 117 }
 118
 119 static_always_inline void
 120 mark_tcp_udp_cksum_calc (vlib_buffer_t *b, u8 *l4_hdr_sz)
 121 {
 122   ethernet_header_t *eth = vlib_buffer_get_current (b);
 123   vnet_buffer_oflags_t oflags = 0;
 124   if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP4)
 125     {
 126       ip4_header_t *ip4 =
 127         (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
 128       b->flags |= VNET_BUFFER_F_IS_IP4;
 129       if (ip4->protocol == IP_PROTOCOL_TCP)
 130         {
 131           oflags |= VNET_BUFFER_OFFLOAD_F_TCP_CKSUM;
 132           tcp_header_t *tcp = (tcp_header_t *) (vlib_buffer_get_current (b) +
 133                                                 sizeof (ethernet_header_t) +
 134                                                 ip4_header_bytes (ip4));
 135           *l4_hdr_sz = tcp_header_bytes (tcp);
 136         }
 137       else if (ip4->protocol == IP_PROTOCOL_UDP)
 138         {
 139           oflags |= VNET_BUFFER_OFFLOAD_F_UDP_CKSUM;
 140           udp_header_t *udp = (udp_header_t *) (vlib_buffer_get_current (b) +
 141                                                 sizeof (ethernet_header_t) +
 142                                                 ip4_header_bytes (ip4));
 143           *l4_hdr_sz = sizeof (*udp);
 144         }
 145       vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
 146       vnet_buffer (b)->l4_hdr_offset =
 147         sizeof (ethernet_header_t) + ip4_header_bytes (ip4);
 148       if (oflags)
 149         vnet_buffer_offload_flags_set (b, oflags);
 150     }
 151   else if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP6)
 152     {
 153       ip6_header_t *ip6 =
 154         (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
 155       b->flags |= VNET_BUFFER_F_IS_IP6;
 156       u16 ip6_hdr_len = sizeof (ip6_header_t);
 157       if (ip6_ext_hdr (ip6->protocol))
 158         {
 159           ip6_ext_header_t *p = (void *) (ip6 + 1);
 160           ip6_hdr_len += ip6_ext_header_len (p);
 161           while (ip6_ext_hdr (p->next_hdr))
 162             {
 163               ip6_hdr_len += ip6_ext_header_len (p);
 164               p = ip6_ext_next_header (p);
 165             }
 166         }
 167       if (ip6->protocol == IP_PROTOCOL_TCP)
 168         {
 169           oflags |= VNET_BUFFER_OFFLOAD_F_TCP_CKSUM;
 170           tcp_header_t *tcp =
 171             (tcp_header_t *) (vlib_buffer_get_current (b) +
 172                               sizeof (ethernet_header_t) + ip6_hdr_len);
 173           *l4_hdr_sz = tcp_header_bytes (tcp);
 174         }
 175       else if (ip6->protocol == IP_PROTOCOL_UDP)
 176         {
 177           oflags |= VNET_BUFFER_OFFLOAD_F_UDP_CKSUM;
 178           udp_header_t *udp =
 179             (udp_header_t *) (vlib_buffer_get_current (b) +
 180                               sizeof (ethernet_header_t) + ip6_hdr_len);
 181           *l4_hdr_sz = sizeof (*udp);
 182         }
 183       vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
 184       vnet_buffer (b)->l4_hdr_offset =
 185         sizeof (ethernet_header_t) + ip6_hdr_len;
 186       if (oflags)
 187         vnet_buffer_offload_flags_set (b, oflags);
 188     }
 189 }
 190
 191 always_inline uword
 192 af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 193                            vlib_frame_t * frame, af_packet_if_t * apif)
 194 {
 195   af_packet_main_t *apm = &af_packet_main;
 196   struct tpacket2_hdr *tph;
 197   u32 next_index;
 198   u32 block = 0;
 199   u32 rx_frame;
 200   u32 n_free_bufs;
 201   u32 n_rx_packets = 0;
 202   u32 n_rx_bytes = 0;
 203   u32 *to_next = 0;
 204   u32 block_size = apif->rx_req->tp_block_size;
 205   u32 frame_size = apif->rx_req->tp_frame_size;
 206   u32 frame_num = apif->rx_req->tp_frame_nr;
 207   u8 *block_start = apif->rx_ring + block * block_size;
 208   uword n_trace = vlib_get_trace_count (vm, node);
 209   u32 thread_index = vm->thread_index;
 210   u32 n_buffer_bytes = vlib_buffer_get_default_data_size (vm);
 211   u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
 212   vlib_buffer_t bt;
 213
 214   if (apif->mode == AF_PACKET_IF_MODE_IP)
 215     {
 216       next_index = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
 217     }
 218   else
 219     {
 220       next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
 221       if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
 222         next_index = apif->per_interface_next_index;
 223
 224       /* redirect if feature path enabled */
 225       vnet_feature_start_device_input_x1 (apif->sw_if_index, &next_index, &bt);
 226     }
 227
 228   n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
 229   if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
 230     {
 231       vec_validate (apm->rx_buffers[thread_index],
 232                     VLIB_FRAME_SIZE + n_free_bufs - 1);
 233       n_free_bufs +=
 234         vlib_buffer_alloc (vm, &apm->rx_buffers[thread_index][n_free_bufs],
 235                            VLIB_FRAME_SIZE);
 236       _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
 237     }
 238
 239   rx_frame = apif->next_rx_frame;
 240   tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
 241   while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
 242     {
 243       vlib_buffer_t *b0 = 0, *first_b0 = 0;
 244       u32 next0 = next_index;
 245
 246       u32 n_left_to_next;
 247       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 248       while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
 249              n_left_to_next)
 250         {
 251           u32 data_len = tph->tp_snaplen;
 252           u32 offset = 0;
 253           u32 bi0 = 0, first_bi0 = 0, prev_bi0;
 254           u8 l4_hdr_sz = 0;
 255
 256           while (data_len)
 257             {
 258               /* grab free buffer */
 259               u32 last_empty_buffer =
 260                 vec_len (apm->rx_buffers[thread_index]) - 1;
 261               prev_bi0 = bi0;
 262               bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
 263               b0 = vlib_get_buffer (vm, bi0);
 264               _vec_len (apm->rx_buffers[thread_index]) = last_empty_buffer;
 265               n_free_bufs--;
 266
 267               /* copy data */
 268               u32 bytes_to_copy =
 269                 data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
 270               u32 vlan_len = 0;
 271               u32 bytes_copied = 0;
 272               b0->current_data = 0;
 273               /* Kernel removes VLAN headers, so reconstruct VLAN */
 274               if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
 275                 {
 276                   if (PREDICT_TRUE (offset == 0))
 277                     {
 278                       clib_memcpy_fast (vlib_buffer_get_current (b0),
 279                                         (u8 *) tph + tph->tp_mac,
 280                                         sizeof (ethernet_header_t));
 281                       ethernet_header_t *eth = vlib_buffer_get_current (b0);
 282                       ethernet_vlan_header_t *vlan =
 283                         (ethernet_vlan_header_t *) (eth + 1);
 284                       vlan->priority_cfi_and_id =
 285                         clib_host_to_net_u16 (tph->tp_vlan_tci);
 286                       vlan->type = eth->type;
 287                       eth->type = clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
 288                       vlan_len = sizeof (ethernet_vlan_header_t);
 289                       bytes_copied = sizeof (ethernet_header_t);
 290                     }
 291                 }
 292               clib_memcpy_fast (((u8 *) vlib_buffer_get_current (b0)) +
 293                                 bytes_copied + vlan_len,
 294                                 (u8 *) tph + tph->tp_mac + offset +
 295                                 bytes_copied, (bytes_to_copy - bytes_copied));
 296
 297               /* fill buffer header */
 298               b0->current_length = bytes_to_copy + vlan_len;
 299
 300               if (offset == 0)
 301                 {
 302                   b0->total_length_not_including_first_buffer = 0;
 303                   b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
 304                   vnet_buffer (b0)->sw_if_index[VLIB_RX] = apif->sw_if_index;
 305                   vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 306                   first_bi0 = bi0;
 307                   first_b0 = vlib_get_buffer (vm, first_bi0);
 308                   if (tph->tp_status & TP_STATUS_CSUMNOTREADY)
 309                     mark_tcp_udp_cksum_calc (first_b0, &l4_hdr_sz);
 310                   if (tph->tp_snaplen > apif->host_mtu)
 311                     fill_gso_buffer_flags (first_b0, apif->host_mtu,
 312                                            l4_hdr_sz);
 313                 }
 314               else
 315                 buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0);
 316
 317               offset += bytes_to_copy;
 318               data_len -= bytes_to_copy;
 319             }
 320           n_rx_packets++;
 321           n_rx_bytes += tph->tp_snaplen;
 322           to_next[0] = first_bi0;
 323           to_next += 1;
 324           n_left_to_next--;
 325
 326           /* drop partial packets */
 327           if (PREDICT_FALSE (tph->tp_len != tph->tp_snaplen))
 328             {
 329               next0 = VNET_DEVICE_INPUT_NEXT_DROP;
 330               first_b0->error =
 331                 node->errors[AF_PACKET_INPUT_ERROR_PARTIAL_PKT];
 332             }
 333           else
 334             {
 335               if (PREDICT_FALSE (apif->mode == AF_PACKET_IF_MODE_IP))
 336                 {
 337                   switch (first_b0->data[0] & 0xf0)
 338                     {
 339                     case 0x40:
 340                       next0 = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
 341                       break;
 342                     case 0x60:
 343                       next0 = VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
 344                       break;
 345                     default:
 346                       next0 = VNET_DEVICE_INPUT_NEXT_DROP;
 347                       break;
 348                     }
 349                   if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
 350                     next0 = apif->per_interface_next_index;
 351                 }
 352               else
 353                 {
 354                   /* copy feature arc data from template */
 355                   first_b0->current_config_index = bt.current_config_index;
 356                   vnet_buffer (first_b0)->feature_arc_index =
 357                     vnet_buffer (&bt)->feature_arc_index;
 358                 }
 359             }
 360
 361           /* trace */
 362           if (PREDICT_FALSE
 363               (n_trace > 0 && vlib_trace_buffer (vm, node, next0, first_b0,
 364                                                  /* follow_chain */ 0)))
 365             {
 366               af_packet_input_trace_t *tr;
 367               vlib_set_trace_count (vm, node, --n_trace);
 368               tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
 369               tr->next_index = next0;
 370               tr->hw_if_index = apif->hw_if_index;
 371               clib_memcpy_fast (&tr->tph, tph, sizeof (struct tpacket2_hdr));
 372             }
 373
 374           /* enque and take next packet */
 375           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 376                                            n_left_to_next, first_bi0, next0);
 377
 378           /* next packet */
 379           tph->tp_status = TP_STATUS_KERNEL;
 380           rx_frame = (rx_frame + 1) % frame_num;
 381           tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
 382         }
 383
 384       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 385     }
 386
 387   apif->next_rx_frame = rx_frame;
 388
 389   vlib_increment_combined_counter
 390     (vnet_get_main ()->interface_main.combined_sw_if_counters
 391      + VNET_INTERFACE_COUNTER_RX,
 392      vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes);
 393
 394   vnet_device_increment_rx_packets (thread_index, n_rx_packets);
 395   return n_rx_packets;
 396 }
 397
 398 VLIB_NODE_FN (af_packet_input_node) (vlib_main_t * vm,
 399                                      vlib_node_runtime_t * node,
 400                                      vlib_frame_t * frame)
 401 {
 402   u32 n_rx_packets = 0;
 403   af_packet_main_t *apm = &af_packet_main;
 404   vnet_hw_if_rxq_poll_vector_t *pv;
 405   pv = vnet_hw_if_get_rxq_poll_vector (vm, node);
 406   for (int i = 0; i < vec_len (pv); i++)
 407     {
 408       af_packet_if_t *apif;
 409       apif = vec_elt_at_index (apm->interfaces, pv[i].dev_instance);
 410       if (apif->is_admin_up)
 411         n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif);
 412     }
 413
 414   return n_rx_packets;
 415 }
 416
 417 VLIB_REGISTER_NODE (af_packet_input_node) = {
 418   .name = "af-packet-input",
 419   .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
 420   .sibling_of = "device-input",
 421   .format_trace = format_af_packet_input_trace,
 422   .type = VLIB_NODE_TYPE_INPUT,
 423   .state = VLIB_NODE_STATE_INTERRUPT,
 424   .n_errors = AF_PACKET_INPUT_N_ERROR,
 425   .error_strings = af_packet_input_error_strings,
 426 };
 427
 428
 429 /*
 430  * fd.io coding-style-patch-verification: ON
 431  *
 432  * Local Variables:
 433  * eval: (c-set-style "gnu")
 434  * End:
 435  */