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   if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP4)
 124     {
 125       ip4_header_t *ip4 =
 126         (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
 127       b->flags |= VNET_BUFFER_F_IS_IP4;
 128       if (ip4->protocol == IP_PROTOCOL_TCP)
 129         {
 130           b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
 131           tcp_header_t *tcp = (tcp_header_t *) (vlib_buffer_get_current (b) +
 132                                                 sizeof (ethernet_header_t) +
 133                                                 ip4_header_bytes (ip4));
 134           tcp->checksum = 0;
 135           *l4_hdr_sz = tcp_header_bytes (tcp);
 136         }
 137       else if (ip4->protocol == IP_PROTOCOL_UDP)
 138         {
 139           b->flags |= VNET_BUFFER_F_OFFLOAD_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           udp->checksum = 0;
 144           *l4_hdr_sz = sizeof (*udp);
 145         }
 146       vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
 147       vnet_buffer (b)->l4_hdr_offset =
 148         sizeof (ethernet_header_t) + ip4_header_bytes (ip4);
 149     }
 150   else if (clib_net_to_host_u16 (eth->type) == ETHERNET_TYPE_IP6)
 151     {
 152       ip6_header_t *ip6 =
 153         (vlib_buffer_get_current (b) + sizeof (ethernet_header_t));
 154       b->flags |= VNET_BUFFER_F_IS_IP6;
 155       u16 ip6_hdr_len = sizeof (ip6_header_t);
 156       if (ip6_ext_hdr (ip6->protocol))
 157         {
 158           ip6_ext_header_t *p = (void *) (ip6 + 1);
 159           ip6_hdr_len += ip6_ext_header_len (p);
 160           while (ip6_ext_hdr (p->next_hdr))
 161             {
 162               ip6_hdr_len += ip6_ext_header_len (p);
 163               p = ip6_ext_next_header (p);
 164             }
 165         }
 166       if (ip6->protocol == IP_PROTOCOL_TCP)
 167         {
 168           b->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
 169           tcp_header_t *tcp =
 170             (tcp_header_t *) (vlib_buffer_get_current (b) +
 171                               sizeof (ethernet_header_t) + ip6_hdr_len);
 172           tcp->checksum = 0;
 173           *l4_hdr_sz = tcp_header_bytes (tcp);
 174         }
 175       else if (ip6->protocol == IP_PROTOCOL_UDP)
 176         {
 177           b->flags |= VNET_BUFFER_F_OFFLOAD_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           udp->checksum = 0;
 182           *l4_hdr_sz = sizeof (*udp);
 183         }
 184       vnet_buffer (b)->l3_hdr_offset = sizeof (ethernet_header_t);
 185       vnet_buffer (b)->l4_hdr_offset =
 186         sizeof (ethernet_header_t) + ip6_hdr_len;
 187     }
 188 }
 189
 190 always_inline uword
 191 af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 192                            vlib_frame_t * frame, af_packet_if_t * apif)
 193 {
 194   af_packet_main_t *apm = &af_packet_main;
 195   struct tpacket2_hdr *tph;
 196   u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
 197   u32 block = 0;
 198   u32 rx_frame;
 199   u32 n_free_bufs;
 200   u32 n_rx_packets = 0;
 201   u32 n_rx_bytes = 0;
 202   u32 *to_next = 0;
 203   u32 block_size = apif->rx_req->tp_block_size;
 204   u32 frame_size = apif->rx_req->tp_frame_size;
 205   u32 frame_num = apif->rx_req->tp_frame_nr;
 206   u8 *block_start = apif->rx_ring + block * block_size;
 207   uword n_trace = vlib_get_trace_count (vm, node);
 208   u32 thread_index = vm->thread_index;
 209   u32 n_buffer_bytes = vlib_buffer_get_default_data_size (vm);
 210   u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
 211
 212   n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
 213   if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
 214     {
 215       vec_validate (apm->rx_buffers[thread_index],
 216                     VLIB_FRAME_SIZE + n_free_bufs - 1);
 217       n_free_bufs +=
 218         vlib_buffer_alloc (vm, &apm->rx_buffers[thread_index][n_free_bufs],
 219                            VLIB_FRAME_SIZE);
 220       _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
 221     }
 222
 223   rx_frame = apif->next_rx_frame;
 224   tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
 225   while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
 226     {
 227       vlib_buffer_t *b0 = 0, *first_b0 = 0;
 228       u32 next0 = next_index;
 229
 230       u32 n_left_to_next;
 231       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 232       while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
 233              n_left_to_next)
 234         {
 235           u32 data_len = tph->tp_snaplen;
 236           u32 offset = 0;
 237           u32 bi0 = 0, first_bi0 = 0, prev_bi0;
 238           u8 l4_hdr_sz = 0;
 239
 240           while (data_len)
 241             {
 242               /* grab free buffer */
 243               u32 last_empty_buffer =
 244                 vec_len (apm->rx_buffers[thread_index]) - 1;
 245               prev_bi0 = bi0;
 246               bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
 247               b0 = vlib_get_buffer (vm, bi0);
 248               _vec_len (apm->rx_buffers[thread_index]) = last_empty_buffer;
 249               n_free_bufs--;
 250
 251               /* copy data */
 252               u32 bytes_to_copy =
 253                 data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
 254               u32 vlan_len = 0;
 255               u32 bytes_copied = 0;
 256               b0->current_data = 0;
 257               /* Kernel removes VLAN headers, so reconstruct VLAN */
 258               if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
 259                 {
 260                   if (PREDICT_TRUE (offset == 0))
 261                     {
 262                       clib_memcpy_fast (vlib_buffer_get_current (b0),
 263                                         (u8 *) tph + tph->tp_mac,
 264                                         sizeof (ethernet_header_t));
 265                       ethernet_header_t *eth = vlib_buffer_get_current (b0);
 266                       ethernet_vlan_header_t *vlan =
 267                         (ethernet_vlan_header_t *) (eth + 1);
 268                       vlan->priority_cfi_and_id =
 269                         clib_host_to_net_u16 (tph->tp_vlan_tci);
 270                       vlan->type = eth->type;
 271                       eth->type = clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
 272                       vlan_len = sizeof (ethernet_vlan_header_t);
 273                       bytes_copied = sizeof (ethernet_header_t);
 274                     }
 275                 }
 276               clib_memcpy_fast (((u8 *) vlib_buffer_get_current (b0)) +
 277                                 bytes_copied + vlan_len,
 278                                 (u8 *) tph + tph->tp_mac + offset +
 279                                 bytes_copied, (bytes_to_copy - bytes_copied));
 280
 281               /* fill buffer header */
 282               b0->current_length = bytes_to_copy + vlan_len;
 283
 284               if (offset == 0)
 285                 {
 286                   b0->total_length_not_including_first_buffer = 0;
 287                   b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
 288                   vnet_buffer (b0)->sw_if_index[VLIB_RX] = apif->sw_if_index;
 289                   vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 290                   first_bi0 = bi0;
 291                   first_b0 = vlib_get_buffer (vm, first_bi0);
 292                   if (tph->tp_status & TP_STATUS_CSUMNOTREADY)
 293                     mark_tcp_udp_cksum_calc (first_b0, &l4_hdr_sz);
 294                   if (tph->tp_snaplen > apif->host_mtu)
 295                     fill_gso_buffer_flags (first_b0, apif->host_mtu,
 296                                            l4_hdr_sz);
 297                 }
 298               else
 299                 buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0);
 300
 301               offset += bytes_to_copy;
 302               data_len -= bytes_to_copy;
 303             }
 304           n_rx_packets++;
 305           n_rx_bytes += tph->tp_snaplen;
 306           to_next[0] = first_bi0;
 307           to_next += 1;
 308           n_left_to_next--;
 309
 310           /* drop partial packets */
 311           if (PREDICT_FALSE (tph->tp_len != tph->tp_snaplen))
 312             {
 313               next0 = VNET_DEVICE_INPUT_NEXT_DROP;
 314               first_b0->error =
 315                 node->errors[AF_PACKET_INPUT_ERROR_PARTIAL_PKT];
 316             }
 317           else
 318             {
 319               next0 = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
 320
 321               if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
 322                 next0 = apif->per_interface_next_index;
 323
 324               /* redirect if feature path enabled */
 325               vnet_feature_start_device_input_x1 (apif->sw_if_index, &next0,
 326                                                   first_b0);
 327             }
 328
 329           /* trace */
 330           VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0);
 331           if (PREDICT_FALSE
 332               (n_trace > 0 && vlib_trace_buffer (vm, node, next0, first_b0,
 333                                                  /* follow_chain */ 0)))
 334             {
 335               af_packet_input_trace_t *tr;
 336               vlib_set_trace_count (vm, node, --n_trace);
 337               tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
 338               tr->next_index = next0;
 339               tr->hw_if_index = apif->hw_if_index;
 340               clib_memcpy_fast (&tr->tph, tph, sizeof (struct tpacket2_hdr));
 341             }
 342
 343           /* enque and take next packet */
 344           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 345                                            n_left_to_next, first_bi0, next0);
 346
 347           /* next packet */
 348           tph->tp_status = TP_STATUS_KERNEL;
 349           rx_frame = (rx_frame + 1) % frame_num;
 350           tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
 351         }
 352
 353       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 354     }
 355
 356   apif->next_rx_frame = rx_frame;
 357
 358   vlib_increment_combined_counter
 359     (vnet_get_main ()->interface_main.combined_sw_if_counters
 360      + VNET_INTERFACE_COUNTER_RX,
 361      vlib_get_thread_index (), apif->hw_if_index, n_rx_packets, n_rx_bytes);
 362
 363   vnet_device_increment_rx_packets (thread_index, n_rx_packets);
 364   return n_rx_packets;
 365 }
 366
 367 VLIB_NODE_FN (af_packet_input_node) (vlib_main_t * vm,
 368                                      vlib_node_runtime_t * node,
 369                                      vlib_frame_t * frame)
 370 {
 371   u32 n_rx_packets = 0;
 372   af_packet_main_t *apm = &af_packet_main;
 373   vnet_hw_if_rxq_poll_vector_t *pv;
 374   pv = vnet_hw_if_get_rxq_poll_vector (vm, node);
 375   for (int i = 0; i < vec_len (pv); i++)
 376     {
 377       af_packet_if_t *apif;
 378       apif = vec_elt_at_index (apm->interfaces, pv[i].dev_instance);
 379       if (apif->is_admin_up)
 380         n_rx_packets += af_packet_device_input_fn (vm, node, frame, apif);
 381     }
 382
 383   return n_rx_packets;
 384 }
 385
 386 /* *INDENT-OFF* */
 387 VLIB_REGISTER_NODE (af_packet_input_node) = {
 388   .name = "af-packet-input",
 389   .flags = VLIB_NODE_FLAG_TRACE_SUPPORTED,
 390   .sibling_of = "device-input",
 391   .format_trace = format_af_packet_input_trace,
 392   .type = VLIB_NODE_TYPE_INPUT,
 393   .state = VLIB_NODE_STATE_INTERRUPT,
 394   .n_errors = AF_PACKET_INPUT_N_ERROR,
 395   .error_strings = af_packet_input_error_strings,
 396 };
 397 /* *INDENT-ON* */
 398
 399
 400 /*
 401  * fd.io coding-style-patch-verification: ON
 402  *
 403  * Local Variables:
 404  * eval: (c-set-style "gnu")
 405  * End:
 406  */