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/devices/devices.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 mark_tcp_udp_cksum_calc (vlib_buffer_t * b)
 113 {
 114   ethernet_header_t *eth = vlib_buffer_get_current (b);
 115   if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP4)
 116     {
 117       ip4_header_t *ip4 =
 118         (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
 119       b->flags |= VNET_BUFFER_F_IS_IP4;
 120       if (ip4->protocol == IP_PROTOCOL_TCP)
 121         {
 122           b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
 123           ((tcp_header_t
 124             *) (vlib_buffer_get_current (b) +
 125                 sizeof (ethernet_header_t) +
 126                 ip4_header_bytes (ip4)))->checksum = 0;
 127         }
 128       else if (ip4->protocol == IP_PROTOCOL_UDP)
 129         {
 130           b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
 131           ((udp_header_t
 132             *) (vlib_buffer_get_current (b) +
 133                 sizeof (ethernet_header_t) +
 134                 ip4_header_bytes (ip4)))->checksum = 0;
 135         }
 136       vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
 137       vnet_buffer (b)->l4_hdr_offset =
 138         sizeof (ethernet_header_t) + ip4_header_bytes (ip4);
 139     }
 140   else if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP6)
 141     {
 142       ip6_header_t *ip6 =
 143         (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
 144       b->flags |= VNET_BUFFER_F_IS_IP6;
 145       u16 ip6_hdr_len = sizeof (ip6_header_t);
 146       if (ip6_ext_hdr (ip6->protocol))
 147         {
 148           ip6_ext_header_t *p = (void *) (ip6 + 1);
 149           ip6_hdr_len += ip6_ext_header_len (p);
 150           while (ip6_ext_hdr (p->next_hdr))
 151             {
 152               ip6_hdr_len += ip6_ext_header_len (p);
 153               p = ip6_ext_next_header (p);
 154             }
 155         }
 156       if (ip6->protocol == IP_PROTOCOL_TCP)
 157         {
 158           b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
 159           ((tcp_header_t
 160             *) (vlib_buffer_get_current (b) +
 161                 sizeof (ethernet_header_t) + ip6_hdr_len))->checksum = 0;
 162         }
 163       else if (ip6->protocol == IP_PROTOCOL_UDP)
 164         {
 165           b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
 166           ((udp_header_t
 167             *) (vlib_buffer_get_current (b) +
 168                 sizeof (ethernet_header_t) + ip6_hdr_len))->checksum = 0;
 169         }
 170       vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
 171       vnet_buffer (b)->l4_hdr_offset =
 172         sizeof (ethernet_header_t) + ip6_hdr_len;
 173     }
 174 }
 175
 176 always_inline uword
 177 af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 178                            vlib_frame_t * frame, af_packet_if_t * apif)
 179 {
 180   af_packet_main_t *apm = &af_packet_main;
 181   struct tpacket2_hdr *tph;
 182   u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
 183   u32 block = 0;
 184   u32 rx_frame;
 185   u32 n_free_bufs;
 186   u32 n_rx_packets = 0;
 187   u32 n_rx_bytes = 0;
 188   u32 *to_next = 0;
 189   u32 block_size = apif->rx_req->tp_block_size;
 190   u32 frame_size = apif->rx_req->tp_frame_size;
 191   u32 frame_num = apif->rx_req->tp_frame_nr;
 192   u8 *block_start = apif->rx_ring + block * block_size;
 193   uword n_trace = vlib_get_trace_count (vm, node);
 194   u32 thread_index = vm->thread_index;
 195   u32 n_buffer_bytes = VLIB_BUFFER_DATA_SIZE;
 196   u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
 197
 198   if (apif->per_interface_next_index != ~0)
 199     next_index = apif->per_interface_next_index;
 200
 201   n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
 202   if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
 203     {
 204       vec_validate (apm->rx_buffers[thread_index],
 205                     VLIB_FRAME_SIZE + n_free_bufs - 1);
 206       n_free_bufs +=
 207         vlib_buffer_alloc (vm, &apm->rx_buffers[thread_index][n_free_bufs],
 208                            VLIB_FRAME_SIZE);
 209       _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
 210     }
 211
 212   rx_frame = apif->next_rx_frame;
 213   tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
 214   while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
 215     {
 216       vlib_buffer_t *b0 = 0, *first_b0 = 0;
 217       u32 next0 = next_index;
 218
 219       u32 n_left_to_next;
 220       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 221       while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
 222              n_left_to_next)
 223         {
 224           u32 data_len = tph->tp_snaplen;
 225           u32 offset = 0;
 226           u32 bi0 = 0, first_bi0 = 0, prev_bi0;
 227
 228           while (data_len)
 229             {
 230               /* grab free buffer */
 231               u32 last_empty_buffer =
 232                 vec_len (apm->rx_buffers[thread_index]) - 1;
 233               prev_bi0 = bi0;
 234               bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
 235               b0 = vlib_get_buffer (vm, bi0);
 236               _vec_len (apm->rx_buffers[thread_index]) = last_empty_buffer;
 237               n_free_bufs--;
 238
 239               /* copy data */
 240               u32 bytes_to_copy =
 241                 data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
 242               u32 vlan_len = 0;
 243               u32 bytes_copied = 0;
 244               b0->current_data = 0;
 245               /* Kernel removes VLAN headers, so reconstruct VLAN */
 246               if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
 247                 {
 248                   if (PREDICT_TRUE (offset == 0))
 249                     {
 250                       clib_memcpy_fast (vlib_buffer_get_current (b0),
 251                                         (u8 *) tph + tph->tp_mac,
 252                                         sizeof (ethernet_header_t));
 253                       ethernet_header_t *eth = vlib_buffer_get_current (b0);
 254                       ethernet_vlan_header_t *vlan =
 255                         (ethernet_vlan_header_t *) (eth + 1);
 256                       vlan->priority_cfi_and_id =
 257                         clib_host_to_net_u16 (tph->tp_vlan_tci);
 258                       vlan->type = eth->type;
 259                       eth->type = clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
 260                       vlan_len = sizeof (ethernet_vlan_header_t);
 261                       bytes_copied = sizeof (ethernet_header_t);
 262                     }
 263                 }
 264               clib_memcpy_fast (((u8 *) vlib_buffer_get_current (b0)) +
 265                                 bytes_copied + vlan_len,
 266                                 (u8 *) tph + tph->tp_mac + offset +
 267                                 bytes_copied, (bytes_to_copy - bytes_copied));
 268
 269               /* fill buffer header */
 270               b0->current_length = bytes_to_copy + vlan_len;
 271
 272               if (offset == 0)
 273                 {
 274                   b0->total_length_not_including_first_buffer = 0;
 275                   b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
 276                   vnet_buffer (b0)->sw_if_index[VLIB_RX] = apif->sw_if_index;
 277                   vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 278                   first_bi0 = bi0;
 279                   first_b0 = vlib_get_buffer (vm, first_bi0);
 280                   if (tph->tp_status & TP_STATUS_CSUMNOTREADY)
 281                     mark_tcp_udp_cksum_calc (first_b0);
 282                 }
 283               else
 284                 buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0);
 285
 286               offset += bytes_to_copy;
 287               data_len -= bytes_to_copy;
 288             }
 289           n_rx_packets++;
 290           n_rx_bytes += tph->tp_snaplen;
 291           to_next[0] = first_bi0;
 292           to_next += 1;
 293           n_left_to_next--;
 294
 295           /* drop partial packets */
 296           if (PREDICT_FALSE (tph->tp_len != tph->tp_snaplen))
 297             {
 298               next0 = VNET_DEVICE_INPUT_NEXT_DROP;
 299               first_b0->error =
 300                 node->errors[AF_PACKET_INPUT_ERROR_PARTIAL_PKT];
 301             }
 302           else
 303             {
 304               next0 = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
 305               /* redirect if feature path enabled */
 306               vnet_feature_start_device_input_x1 (apif->sw_if_index, &next0,
 307                                                   first_b0);
 308             }
 309
 310           /* trace */
 311           VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0);
 312           if (PREDICT_FALSE (n_trace > 0))
 313             {
 314               af_packet_input_trace_t *tr;
 315               vlib_trace_buffer (vm, node, next0, first_b0,     /* follow_chain */
 316                                  0);
 317               vlib_set_trace_count (vm, node, --n_trace);
 318               tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
 319               tr->next_index = next0;
 320               tr->hw_if_index = apif->hw_if_index;
 321               clib_memcpy_fast (&tr->tph, tph, sizeof (struct tpacket2_hdr));
 322             }
 323
 324           /* enque and take next packet */
 325           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 326                                            n_left_to_next, first_bi0, next0);
 327
 328           /* next packet */
 329           tph->tp_status = TP_STATUS_KERNEL;
 330           rx_frame = (rx_frame + 1) % frame_num;
 331           tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
 332         }
 333
 334       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 335     }
 336
 337   apif->next_rx_frame = rx_frame;
 338
 339   vlib_increment_combined_counter
 340     (vnet_get_main ()->interface_main.combined_sw_if_counters
 341      + VNET_INTERFACE_COUNTER_RX,
 342      vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes);
 343
 344   vnet_device_increment_rx_packets (thread_index, n_rx_packets);
 345   return n_rx_packets;
 346 }
 347
 348 static uword
 349 af_packet_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 350                     vlib_frame_t * frame)
 351 {
 352   u32 n_rx_packets = 0;
 353   af_packet_main_t *apm = &af_packet_main;
 354   vnet_device_input_runtime_t *rt = (void *) node->runtime_data;
 355   vnet_device_and_queue_t *dq;
 356
 357   foreach_device_and_queue (dq, rt->devices_and_queues)
 358   {
 359     af_packet_if_t *apif;
 360     apif = vec_elt_at_index (apm->interfaces, dq->dev_instance);
 361     if (apif->is_admin_up)
 362       n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif);
 363   }
 364
 365   return n_rx_packets;
 366 }
 367
 368 /* *INDENT-OFF* */
 369 VLIB_REGISTER_NODE (af_packet_input_node) = {
 370   .function = af_packet_input_fn,
 371   .name = "af-packet-input",
 372   .sibling_of = "device-input",
 373   .format_trace = format_af_packet_input_trace,
 374   .type = VLIB_NODE_TYPE_INPUT,
 375   .state = VLIB_NODE_STATE_INTERRUPT,
 376   .n_errors = AF_PACKET_INPUT_N_ERROR,
 377   .error_strings = af_packet_input_error_strings,
 378 };
 379
 380 VLIB_NODE_FUNCTION_MULTIARCH (af_packet_input_node, af_packet_input_fn)
 381 /* *INDENT-ON* */
 382
 383
 384 /*
 385  * fd.io coding-style-patch-verification: ON
 386  *
 387  * Local Variables:
 388  * eval: (c-set-style "gnu")
 389  * End:
 390  */