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
  34 typedef enum
  35 {
  36 #define _(f,s) AF_PACKET_INPUT_ERROR_##f,
  37   foreach_af_packet_input_error
  38 #undef _
  39     AF_PACKET_INPUT_N_ERROR,
  40 } af_packet_input_error_t;
  41
  42 static char *af_packet_input_error_strings[] = {
  43 #define _(n,s) s,
  44   foreach_af_packet_input_error
  45 #undef _
  46 };
  47
  48 typedef struct
  49 {
  50   u32 next_index;
  51   u32 hw_if_index;
  52   int block;
  53   struct tpacket2_hdr tph;
  54 } af_packet_input_trace_t;
  55
  56 static u8 *
  57 format_af_packet_input_trace (u8 * s, va_list * args)
  58 {
  59   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  60   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  61   af_packet_input_trace_t *t = va_arg (*args, af_packet_input_trace_t *);
  62   u32 indent = format_get_indent (s);
  63
  64   s = format (s, "af_packet: hw_if_index %d next-index %d",
  65               t->hw_if_index, t->next_index);
  66
  67   s =
  68     format (s,
  69             "\n%Utpacket2_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
  70             "\n%Usec 0x%x nsec 0x%x vlan %U"
  71 #ifdef TP_STATUS_VLAN_TPID_VALID
  72             " vlan_tpid %u"
  73 #endif
  74             ,
  75             format_white_space, indent + 2,
  76             format_white_space, indent + 4,
  77             t->tph.tp_status,
  78             t->tph.tp_len,
  79             t->tph.tp_snaplen,
  80             t->tph.tp_mac,
  81             t->tph.tp_net,
  82             format_white_space, indent + 4,
  83             t->tph.tp_sec,
  84             t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.tp_vlan_tci
  85 #ifdef TP_STATUS_VLAN_TPID_VALID
  86             , t->tph.tp_vlan_tpid
  87 #endif
  88     );
  89   return s;
  90 }
  91
  92 always_inline void
  93 buffer_add_to_chain (vlib_main_t * vm, u32 bi, u32 first_bi, u32 prev_bi)
  94 {
  95   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
  96   vlib_buffer_t *first_b = vlib_get_buffer (vm, first_bi);
  97   vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_bi);
  98
  99   /* update first buffer */
 100   first_b->total_length_not_including_first_buffer += b->current_length;
 101
 102   /* update previous buffer */
 103   prev_b->next_buffer = bi;
 104   prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 105
 106   /* update current buffer */
 107   b->next_buffer = 0;
 108 }
 109
 110 static_always_inline void
 111 mark_tcp_udp_cksum_calc (vlib_buffer_t * b)
 112 {
 113   ethernet_header_t *eth = vlib_buffer_get_current (b);
 114   if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP4)
 115     {
 116       ip4_header_t *ip4 =
 117         (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
 118       b->flags |= VNET_BUFFER_F_IS_IP4;
 119       if (ip4->protocol == IP_PROTOCOL_TCP)
 120         {
 121           b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
 122           ((tcp_header_t
 123             *) (vlib_buffer_get_current (b) +
 124                 sizeof (ethernet_header_t) +
 125                 ip4_header_bytes (ip4)))->checksum = 0;
 126         }
 127       else if (ip4->protocol == IP_PROTOCOL_UDP)
 128         {
 129           b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
 130           ((udp_header_t
 131             *) (vlib_buffer_get_current (b) +
 132                 sizeof (ethernet_header_t) +
 133                 ip4_header_bytes (ip4)))->checksum = 0;
 134         }
 135       vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
 136       vnet_buffer (b)->l4_hdr_offset =
 137         sizeof (ethernet_header_t) + ip4_header_bytes (ip4);
 138     }
 139   else if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP6)
 140     {
 141       ip6_header_t *ip6 =
 142         (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
 143       b->flags |= VNET_BUFFER_F_IS_IP6;
 144       u16 ip6_hdr_len = sizeof (ip6_header_t);
 145       if (ip6_ext_hdr (ip6->protocol))
 146         {
 147           ip6_ext_header_t *p = (void *) (ip6 + 1);
 148           ip6_hdr_len += ip6_ext_header_len (p);
 149           while (ip6_ext_hdr (p->next_hdr))
 150             {
 151               ip6_hdr_len += ip6_ext_header_len (p);
 152               p = ip6_ext_next_header (p);
 153             }
 154         }
 155       if (ip6->protocol == IP_PROTOCOL_TCP)
 156         {
 157           b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
 158           ((tcp_header_t
 159             *) (vlib_buffer_get_current (b) +
 160                 sizeof (ethernet_header_t) + ip6_hdr_len))->checksum = 0;
 161         }
 162       else if (ip6->protocol == IP_PROTOCOL_UDP)
 163         {
 164           b->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
 165           ((udp_header_t
 166             *) (vlib_buffer_get_current (b) +
 167                 sizeof (ethernet_header_t) + ip6_hdr_len))->checksum = 0;
 168         }
 169       vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
 170       vnet_buffer (b)->l4_hdr_offset =
 171         sizeof (ethernet_header_t) + ip6_hdr_len;
 172     }
 173 }
 174
 175 always_inline uword
 176 af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 177                            vlib_frame_t * frame, af_packet_if_t * apif)
 178 {
 179   af_packet_main_t *apm = &af_packet_main;
 180   struct tpacket2_hdr *tph;
 181   u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
 182   u32 block = 0;
 183   u32 rx_frame;
 184   u32 n_free_bufs;
 185   u32 n_rx_packets = 0;
 186   u32 n_rx_bytes = 0;
 187   u32 *to_next = 0;
 188   u32 block_size = apif->rx_req->tp_block_size;
 189   u32 frame_size = apif->rx_req->tp_frame_size;
 190   u32 frame_num = apif->rx_req->tp_frame_nr;
 191   u8 *block_start = apif->rx_ring + block * block_size;
 192   uword n_trace = vlib_get_trace_count (vm, node);
 193   u32 thread_index = vlib_get_thread_index ();
 194   u32 n_buffer_bytes = vlib_buffer_free_list_buffer_size (vm,
 195                                                           VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
 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 (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 (((u8 *) vlib_buffer_get_current (b0)) +
 265                            bytes_copied + vlan_len,
 266                            (u8 *) tph + tph->tp_mac + offset + bytes_copied,
 267                            (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           /* trace */
 296           VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0);
 297           if (PREDICT_FALSE (n_trace > 0))
 298             {
 299               af_packet_input_trace_t *tr;
 300               vlib_trace_buffer (vm, node, next0, first_b0,     /* follow_chain */
 301                                  0);
 302               vlib_set_trace_count (vm, node, --n_trace);
 303               tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
 304               tr->next_index = next0;
 305               tr->hw_if_index = apif->hw_if_index;
 306               clib_memcpy (&tr->tph, tph, sizeof (struct tpacket2_hdr));
 307             }
 308
 309           /* redirect if feature path enabled */
 310           vnet_feature_start_device_input_x1 (apif->sw_if_index, &next0, b0);
 311
 312           /* enque and take next packet */
 313           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 314                                            n_left_to_next, first_bi0, next0);
 315
 316           /* next packet */
 317           tph->tp_status = TP_STATUS_KERNEL;
 318           rx_frame = (rx_frame + 1) % frame_num;
 319           tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
 320         }
 321
 322       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 323     }
 324
 325   apif->next_rx_frame = rx_frame;
 326
 327   vlib_increment_combined_counter
 328     (vnet_get_main ()->interface_main.combined_sw_if_counters
 329      + VNET_INTERFACE_COUNTER_RX,
 330      vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes);
 331
 332   vnet_device_increment_rx_packets (thread_index, n_rx_packets);
 333   return n_rx_packets;
 334 }
 335
 336 static uword
 337 af_packet_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 338                     vlib_frame_t * frame)
 339 {
 340   u32 n_rx_packets = 0;
 341   af_packet_main_t *apm = &af_packet_main;
 342   vnet_device_input_runtime_t *rt = (void *) node->runtime_data;
 343   vnet_device_and_queue_t *dq;
 344
 345   foreach_device_and_queue (dq, rt->devices_and_queues)
 346   {
 347     af_packet_if_t *apif;
 348     apif = vec_elt_at_index (apm->interfaces, dq->dev_instance);
 349     if (apif->is_admin_up)
 350       n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif);
 351   }
 352
 353   return n_rx_packets;
 354 }
 355
 356 /* *INDENT-OFF* */
 357 VLIB_REGISTER_NODE (af_packet_input_node) = {
 358   .function = af_packet_input_fn,
 359   .name = "af-packet-input",
 360   .sibling_of = "device-input",
 361   .format_trace = format_af_packet_input_trace,
 362   .type = VLIB_NODE_TYPE_INPUT,
 363   .state = VLIB_NODE_STATE_INTERRUPT,
 364   .n_errors = AF_PACKET_INPUT_N_ERROR,
 365   .error_strings = af_packet_input_error_strings,
 366 };
 367
 368 VLIB_NODE_FUNCTION_MULTIARCH (af_packet_input_node, af_packet_input_fn)
 369 /* *INDENT-ON* */
 370
 371
 372 /*
 373  * fd.io coding-style-patch-verification: ON
 374  *
 375  * Local Variables:
 376  * eval: (c-set-style "gnu")
 377  * End:
 378  */