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
  29 #include <vnet/devices/af_packet/af_packet.h>
  30
  31 #define foreach_af_packet_input_error
  32
  33 typedef enum
  34 {
  35 #define _(f,s) AF_PACKET_INPUT_ERROR_##f,
  36   foreach_af_packet_input_error
  37 #undef _
  38     AF_PACKET_INPUT_N_ERROR,
  39 } af_packet_input_error_t;
  40
  41 static char *af_packet_input_error_strings[] = {
  42 #define _(n,s) s,
  43   foreach_af_packet_input_error
  44 #undef _
  45 };
  46
  47 typedef struct
  48 {
  49   u32 next_index;
  50   u32 hw_if_index;
  51   int block;
  52   struct tpacket2_hdr tph;
  53 } af_packet_input_trace_t;
  54
  55 static u8 *
  56 format_af_packet_input_trace (u8 * s, va_list * args)
  57 {
  58   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  59   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  60   af_packet_input_trace_t *t = va_arg (*args, af_packet_input_trace_t *);
  61   uword indent = format_get_indent (s);
  62
  63   s = format (s, "af_packet: hw_if_index %d next-index %d",
  64               t->hw_if_index, t->next_index);
  65
  66   s =
  67     format (s,
  68             "\n%Utpacket2_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
  69             "\n%Usec 0x%x nsec 0x%x vlan %U"
  70 #ifdef TP_STATUS_VLAN_TPID_VALID
  71             " vlan_tpid %u"
  72 #endif
  73             ,
  74             format_white_space, indent + 2,
  75             format_white_space, indent + 4,
  76             t->tph.tp_status,
  77             t->tph.tp_len,
  78             t->tph.tp_snaplen,
  79             t->tph.tp_mac,
  80             t->tph.tp_net,
  81             format_white_space, indent + 4,
  82             t->tph.tp_sec,
  83             t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.tp_vlan_tci
  84 #ifdef TP_STATUS_VLAN_TPID_VALID
  85             , t->tph.tp_vlan_tpid
  86 #endif
  87     );
  88   return s;
  89 }
  90
  91 always_inline void
  92 buffer_add_to_chain (vlib_main_t * vm, u32 bi, u32 first_bi, u32 prev_bi)
  93 {
  94   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
  95   vlib_buffer_t *first_b = vlib_get_buffer (vm, first_bi);
  96   vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_bi);
  97
  98   /* update first buffer */
  99   first_b->total_length_not_including_first_buffer += b->current_length;
 100
 101   /* update previous buffer */
 102   prev_b->next_buffer = bi;
 103   prev_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
 104
 105   /* update current buffer */
 106   b->next_buffer = 0;
 107 }
 108
 109 always_inline uword
 110 af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 111                            vlib_frame_t * frame, u32 device_idx)
 112 {
 113   af_packet_main_t *apm = &af_packet_main;
 114   af_packet_if_t *apif = pool_elt_at_index (apm->interfaces, device_idx);
 115   struct tpacket2_hdr *tph;
 116   u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
 117   u32 block = 0;
 118   u32 rx_frame;
 119   u32 n_free_bufs;
 120   u32 n_rx_packets = 0;
 121   u32 n_rx_bytes = 0;
 122   u32 *to_next = 0;
 123   u32 block_size = apif->rx_req->tp_block_size;
 124   u32 frame_size = apif->rx_req->tp_frame_size;
 125   u32 frame_num = apif->rx_req->tp_frame_nr;
 126   u8 *block_start = apif->rx_ring + block * block_size;
 127   uword n_trace = vlib_get_trace_count (vm, node);
 128   u32 n_buffer_bytes = vlib_buffer_free_list_buffer_size (vm,
 129                                                           VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
 130   u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
 131   int cpu_index = node->cpu_index;
 132
 133   if (apif->per_interface_next_index != ~0)
 134     next_index = apif->per_interface_next_index;
 135
 136   n_free_bufs = vec_len (apm->rx_buffers[cpu_index]);
 137   if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
 138     {
 139       vec_validate (apm->rx_buffers[cpu_index],
 140                     VLIB_FRAME_SIZE + n_free_bufs - 1);
 141       n_free_bufs +=
 142         vlib_buffer_alloc (vm, &apm->rx_buffers[cpu_index][n_free_bufs],
 143                            VLIB_FRAME_SIZE);
 144       _vec_len (apm->rx_buffers[cpu_index]) = n_free_bufs;
 145     }
 146
 147   rx_frame = apif->next_rx_frame;
 148   tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
 149   while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
 150     {
 151       vlib_buffer_t *b0 = 0, *first_b0 = 0;
 152       u32 next0 = next_index;
 153
 154       u32 n_left_to_next;
 155       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 156       while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
 157              n_left_to_next)
 158         {
 159           u32 data_len = tph->tp_snaplen;
 160           u32 offset = 0;
 161           u32 bi0 = 0, first_bi0 = 0, prev_bi0;
 162
 163           while (data_len)
 164             {
 165               /* grab free buffer */
 166               u32 last_empty_buffer =
 167                 vec_len (apm->rx_buffers[cpu_index]) - 1;
 168               prev_bi0 = bi0;
 169               bi0 = apm->rx_buffers[cpu_index][last_empty_buffer];
 170               b0 = vlib_get_buffer (vm, bi0);
 171               _vec_len (apm->rx_buffers[cpu_index]) = last_empty_buffer;
 172               n_free_bufs--;
 173
 174               /* copy data */
 175               u32 bytes_to_copy =
 176                 data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
 177               b0->current_data = 0;
 178               clib_memcpy (vlib_buffer_get_current (b0),
 179                            (u8 *) tph + tph->tp_mac + offset, bytes_to_copy);
 180
 181               /* fill buffer header */
 182               b0->current_length = bytes_to_copy;
 183
 184               if (offset == 0)
 185                 {
 186                   b0->total_length_not_including_first_buffer = 0;
 187                   b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
 188                   vnet_buffer (b0)->sw_if_index[VLIB_RX] = apif->sw_if_index;
 189                   vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
 190                   first_bi0 = bi0;
 191                   first_b0 = vlib_get_buffer (vm, first_bi0);
 192                 }
 193               else
 194                 buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0);
 195
 196               offset += bytes_to_copy;
 197               data_len -= bytes_to_copy;
 198             }
 199           n_rx_packets++;
 200           n_rx_bytes += tph->tp_snaplen;
 201           to_next[0] = first_bi0;
 202           to_next += 1;
 203           n_left_to_next--;
 204
 205           /* trace */
 206           VLIB_BUFFER_TRACE_TRAJECTORY_INIT (first_b0);
 207           if (PREDICT_FALSE (n_trace > 0))
 208             {
 209               af_packet_input_trace_t *tr;
 210               vlib_trace_buffer (vm, node, next0, first_b0,     /* follow_chain */
 211                                  0);
 212               vlib_set_trace_count (vm, node, --n_trace);
 213               tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
 214               tr->next_index = next0;
 215               tr->hw_if_index = apif->hw_if_index;
 216               clib_memcpy (&tr->tph, tph, sizeof (struct tpacket2_hdr));
 217             }
 218
 219           /* redirect if feature path enabled */
 220           vnet_feature_start_device_input_x1 (apif->sw_if_index, &next0, b0,
 221                                               0);
 222
 223           /* enque and take next packet */
 224           vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
 225                                            n_left_to_next, first_bi0, next0);
 226
 227           /* next packet */
 228           tph->tp_status = TP_STATUS_KERNEL;
 229           rx_frame = (rx_frame + 1) % frame_num;
 230           tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
 231         }
 232
 233       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 234     }
 235
 236   apif->next_rx_frame = rx_frame;
 237
 238   vlib_increment_combined_counter
 239     (vnet_get_main ()->interface_main.combined_sw_if_counters
 240      + VNET_INTERFACE_COUNTER_RX,
 241      os_get_cpu_number (), apif->hw_if_index, n_rx_packets, n_rx_bytes);
 242
 243   return n_rx_packets;
 244 }
 245
 246 static uword
 247 af_packet_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 248                     vlib_frame_t * frame)
 249 {
 250   int i;
 251   u32 n_rx_packets = 0;
 252
 253   af_packet_main_t *apm = &af_packet_main;
 254
 255   /* *INDENT-OFF* */
 256   clib_bitmap_foreach (i, apm->pending_input_bitmap,
 257     ({
 258       clib_bitmap_set (apm->pending_input_bitmap, i, 0);
 259       n_rx_packets += af_packet_device_input_fn(vm, node, frame, i);
 260     }));
 261   /* *INDENT-ON* */
 262
 263   return n_rx_packets;
 264 }
 265
 266 /* *INDENT-OFF* */
 267 VLIB_REGISTER_NODE (af_packet_input_node) = {
 268   .function = af_packet_input_fn,
 269   .name = "af-packet-input",
 270   .sibling_of = "device-input",
 271   .format_trace = format_af_packet_input_trace,
 272   .type = VLIB_NODE_TYPE_INPUT,
 273   .state = VLIB_NODE_STATE_INTERRUPT,
 274   .n_errors = AF_PACKET_INPUT_N_ERROR,
 275   .error_strings = af_packet_input_error_strings,
 276 };
 277
 278 VLIB_NODE_FUNCTION_MULTIARCH (af_packet_input_node, af_packet_input_fn)
 279 /* *INDENT-ON* */
 280
 281
 282 /*
 283  * fd.io coding-style-patch-verification: ON
 284  *
 285  * Local Variables:
 286  * eval: (c-set-style "gnu")
 287  * End:
 288  */