src/examples/sample-plugin/sample/node.c

   1 /*
   2  * Copyright (c) 2015 Cisco and/or its affiliates.
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15 #include <vlib/vlib.h>
  16 #include <vnet/vnet.h>
  17 #include <vnet/pg/pg.h>
  18 #include <vppinfra/error.h>
  19 #include <sample/sample.h>
  20
  21 typedef struct {
  22   u32 next_index;
  23   u32 sw_if_index;
  24   u8 new_src_mac[6];
  25   u8 new_dst_mac[6];
  26 } sample_trace_t;
  27
  28 static u8 *
  29 format_mac_address (u8 * s, va_list * args)
  30 {
  31   u8 *a = va_arg (*args, u8 *);
  32   return format (s, "%02x:%02x:%02x:%02x:%02x:%02x",
  33                  a[0], a[1], a[2], a[3], a[4], a[5]);
  34 }
  35
  36 /* packet trace format function */
  37 static u8 * format_sample_trace (u8 * s, va_list * args)
  38 {
  39   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  40   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  41   sample_trace_t * t = va_arg (*args, sample_trace_t *);
  42
  43   s = format (s, "SAMPLE: sw_if_index %d, next index %d\n",
  44               t->sw_if_index, t->next_index);
  45   s = format (s, "  new src %U -> new dst %U",
  46               format_mac_address, t->new_src_mac,
  47               format_mac_address, t->new_dst_mac);
  48
  49   return s;
  50 }
  51
  52 vlib_node_registration_t sample_node;
  53
  54 #define foreach_sample_error \
  55 _(SWAPPED, "Mac swap packets processed")
  56
  57 typedef enum {
  58 #define _(sym,str) SAMPLE_ERROR_##sym,
  59   foreach_sample_error
  60 #undef _
  61   SAMPLE_N_ERROR,
  62 } sample_error_t;
  63
  64 static char * sample_error_strings[] = {
  65 #define _(sym,string) string,
  66   foreach_sample_error
  67 #undef _
  68 };
  69
  70 typedef enum {
  71   SAMPLE_NEXT_INTERFACE_OUTPUT,
  72   SAMPLE_N_NEXT,
  73 } sample_next_t;
  74
  75 #define foreach_mac_address_offset              \
  76 _(0)                                            \
  77 _(1)                                            \
  78 _(2)                                            \
  79 _(3)                                            \
  80 _(4)                                            \
  81 _(5)
  82
  83 static uword
  84 sample_node_fn (vlib_main_t * vm,
  85                   vlib_node_runtime_t * node,
  86                   vlib_frame_t * frame)
  87 {
  88   u32 n_left_from, * from, * to_next;
  89   sample_next_t next_index;
  90   u32 pkts_swapped = 0;
  91
  92   from = vlib_frame_vector_args (frame);
  93   n_left_from = frame->n_vectors;
  94   next_index = node->cached_next_index;
  95
  96   while (n_left_from > 0)
  97     {
  98       u32 n_left_to_next;
  99
 100       vlib_get_next_frame (vm, node, next_index,
 101                            to_next, n_left_to_next);
 102
 103       while (n_left_from >= 4 && n_left_to_next >= 2)
 104         {
 105           u32 next0 = SAMPLE_NEXT_INTERFACE_OUTPUT;
 106           u32 next1 = SAMPLE_NEXT_INTERFACE_OUTPUT;
 107           u32 sw_if_index0, sw_if_index1;
 108           u8 tmp0[6], tmp1[6];
 109           ethernet_header_t *en0, *en1;
 110           u32 bi0, bi1;
 111           vlib_buffer_t * b0, * b1;
 112
 113           /* Prefetch next iteration. */
 114           {
 115             vlib_buffer_t * p2, * p3;
 116
 117             p2 = vlib_get_buffer (vm, from[2]);
 118             p3 = vlib_get_buffer (vm, from[3]);
 119
 120             vlib_prefetch_buffer_header (p2, LOAD);
 121             vlib_prefetch_buffer_header (p3, LOAD);
 122
 123             CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE);
 124             CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE);
 125           }
 126
 127           /* speculatively enqueue b0 and b1 to the current next frame */
 128           to_next[0] = bi0 = from[0];
 129           to_next[1] = bi1 = from[1];
 130           from += 2;
 131           to_next += 2;
 132           n_left_from -= 2;
 133           n_left_to_next -= 2;
 134
 135           b0 = vlib_get_buffer (vm, bi0);
 136           b1 = vlib_get_buffer (vm, bi1);
 137
 138           ASSERT (b0->current_data == 0);
 139           ASSERT (b1->current_data == 0);
 140
 141           en0 = vlib_buffer_get_current (b0);
 142           en1 = vlib_buffer_get_current (b1);
 143
 144           /* This is not the fastest way to swap src + dst mac addresses */
 145 #define _(a) tmp0[a] = en0->src_address[a];
 146           foreach_mac_address_offset;
 147 #undef _
 148 #define _(a) en0->src_address[a] = en0->dst_address[a];
 149           foreach_mac_address_offset;
 150 #undef _
 151 #define _(a) en0->dst_address[a] = tmp0[a];
 152           foreach_mac_address_offset;
 153 #undef _
 154
 155 #define _(a) tmp1[a] = en1->src_address[a];
 156           foreach_mac_address_offset;
 157 #undef _
 158 #define _(a) en1->src_address[a] = en1->dst_address[a];
 159           foreach_mac_address_offset;
 160 #undef _
 161 #define _(a) en1->dst_address[a] = tmp1[a];
 162           foreach_mac_address_offset;
 163 #undef _
 164
 165
 166
 167           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
 168           sw_if_index1 = vnet_buffer(b1)->sw_if_index[VLIB_RX];
 169
 170           /* Send pkt back out the RX interface */
 171           vnet_buffer(b0)->sw_if_index[VLIB_TX] = sw_if_index0;
 172           vnet_buffer(b1)->sw_if_index[VLIB_TX] = sw_if_index1;
 173
 174           pkts_swapped += 2;
 175
 176           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)))
 177             {
 178               if (b0->flags & VLIB_BUFFER_IS_TRACED)
 179                 {
 180                     sample_trace_t *t =
 181                       vlib_add_trace (vm, node, b0, sizeof (*t));
 182                     t->sw_if_index = sw_if_index0;
 183                     t->next_index = next0;
 184                     clib_memcpy (t->new_src_mac, en0->src_address,
 185                                  sizeof (t->new_src_mac));
 186                     clib_memcpy (t->new_dst_mac, en0->dst_address,
 187                                  sizeof (t->new_dst_mac));
 188
 189                   }
 190                 if (b1->flags & VLIB_BUFFER_IS_TRACED)
 191                   {
 192                     sample_trace_t *t =
 193                       vlib_add_trace (vm, node, b1, sizeof (*t));
 194                     t->sw_if_index = sw_if_index1;
 195                     t->next_index = next1;
 196                     clib_memcpy (t->new_src_mac, en1->src_address,
 197                                  sizeof (t->new_src_mac));
 198                     clib_memcpy (t->new_dst_mac, en1->dst_address,
 199                                  sizeof (t->new_dst_mac));
 200                   }
 201               }
 202
 203             /* verify speculative enqueues, maybe switch current next frame */
 204             vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
 205                                              to_next, n_left_to_next,
 206                                              bi0, bi1, next0, next1);
 207         }
 208
 209       while (n_left_from > 0 && n_left_to_next > 0)
 210         {
 211           u32 bi0;
 212           vlib_buffer_t * b0;
 213           u32 next0 = SAMPLE_NEXT_INTERFACE_OUTPUT;
 214           u32 sw_if_index0;
 215           u8 tmp0[6];
 216           ethernet_header_t *en0;
 217
 218           /* speculatively enqueue b0 to the current next frame */
 219           bi0 = from[0];
 220           to_next[0] = bi0;
 221           from += 1;
 222           to_next += 1;
 223           n_left_from -= 1;
 224           n_left_to_next -= 1;
 225
 226           b0 = vlib_get_buffer (vm, bi0);
 227           /*
 228            * Direct from the driver, we should be at offset 0
 229            * aka at &b0->data[0]
 230            */
 231           ASSERT (b0->current_data == 0);
 232
 233           en0 = vlib_buffer_get_current (b0);
 234
 235           /* This is not the fastest way to swap src + dst mac addresses */
 236 #define _(a) tmp0[a] = en0->src_address[a];
 237           foreach_mac_address_offset;
 238 #undef _
 239 #define _(a) en0->src_address[a] = en0->dst_address[a];
 240           foreach_mac_address_offset;
 241 #undef _
 242 #define _(a) en0->dst_address[a] = tmp0[a];
 243           foreach_mac_address_offset;
 244 #undef _
 245
 246           sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
 247
 248           /* Send pkt back out the RX interface */
 249           vnet_buffer(b0)->sw_if_index[VLIB_TX] = sw_if_index0;
 250
 251           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
 252                             && (b0->flags & VLIB_BUFFER_IS_TRACED))) {
 253             sample_trace_t *t =
 254                vlib_add_trace (vm, node, b0, sizeof (*t));
 255             t->sw_if_index = sw_if_index0;
 256             t->next_index = next0;
 257             clib_memcpy (t->new_src_mac, en0->src_address,
 258                          sizeof (t->new_src_mac));
 259             clib_memcpy (t->new_dst_mac, en0->dst_address,
 260                          sizeof (t->new_dst_mac));
 261             }
 262
 263           pkts_swapped += 1;
 264
 265           /* verify speculative enqueue, maybe switch current next frame */
 266           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 267                                            to_next, n_left_to_next,
 268                                            bi0, next0);
 269         }
 270
 271       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 272     }
 273
 274   vlib_node_increment_counter (vm, sample_node.index,
 275                                SAMPLE_ERROR_SWAPPED, pkts_swapped);
 276   return frame->n_vectors;
 277 }
 278
 279 VLIB_REGISTER_NODE (sample_node) = {
 280   .function = sample_node_fn,
 281   .name = "sample",
 282   .vector_size = sizeof (u32),
 283   .format_trace = format_sample_trace,
 284   .type = VLIB_NODE_TYPE_INTERNAL,
 285
 286   .n_errors = ARRAY_LEN(sample_error_strings),
 287   .error_strings = sample_error_strings,
 288
 289   .n_next_nodes = SAMPLE_N_NEXT,
 290
 291   /* edit / add dispositions here */
 292   .next_nodes = {
 293         [SAMPLE_NEXT_INTERFACE_OUTPUT] = "interface-output",
 294   },
 295 };