vnet/vnet/l2/feat_bitmap.c

   1 /*
   2  * feat_bitmap.c: bitmap for managing feature invocation
   3  *
   4  * Copyright (c) 2013 Cisco and/or its affiliates.
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at:
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #include <vlib/vlib.h>
  19 #include <vnet/vnet.h>
  20 #include <vnet/pg/pg.h>
  21 #include <vnet/ethernet/ethernet.h>
  22 #include <vnet/ethernet/packet.h>
  23 #include <vlib/cli.h>
  24 #include <vnet/l2/l2_input.h>
  25 #include <vnet/l2/feat_bitmap.h>
  26
  27 #include <vppinfra/error.h>
  28 #include <vppinfra/hash.h>
  29 #include <vppinfra/cache.h>
  30
  31
  32 // Drop node for feature bitmaps
  33 // For features that just do a drop, or are not yet implemented.
  34 // Initial feature dispatch nodes don't need to set b0->error
  35 // in case of a possible drop because that will be done here.
  36 // The next node is always error-drop.
  37
  38
  39 static vlib_node_registration_t feat_bitmap_drop_node;
  40
  41 #define foreach_feat_bitmap_drop_error          \
  42 _(NO_FWD,     "L2 feature forwarding disabled") \
  43 _(NYI,        "L2 feature not implemented")
  44
  45 typedef enum {
  46 #define _(sym,str) FEAT_BITMAP_DROP_ERROR_##sym,
  47   foreach_feat_bitmap_drop_error
  48 #undef _
  49   FEAT_BITMAP_DROP_N_ERROR,
  50 } feat_bitmap_drop_error_t;
  51
  52 static char * feat_bitmap_drop_error_strings[] = {
  53 #define _(sym,string) string,
  54   foreach_feat_bitmap_drop_error
  55 #undef _
  56 };
  57
  58 typedef enum {
  59   FEAT_BITMAP_DROP_NEXT_DROP,
  60   FEAT_BITMAP_DROP_N_NEXT,
  61 } feat_bitmap_drop_next_t;
  62
  63 typedef struct {
  64   u32 feature_bitmap;
  65 } feat_bitmap_drop_trace_t;
  66
  67 /* packet trace format function */
  68 static u8 * format_feat_bitmap_drop_trace (u8 * s, va_list * args)
  69 {
  70   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  71   CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  72   feat_bitmap_drop_trace_t * t = va_arg (*args, feat_bitmap_drop_trace_t *);
  73
  74   s = format (s, "feat_bitmap_drop: feature bitmap 0x%08x", t->feature_bitmap);
  75   return s;
  76 }
  77
  78 static uword
  79 feat_bitmap_drop_node_fn (vlib_main_t * vm,
  80                        vlib_node_runtime_t * node,
  81                        vlib_frame_t * frame)
  82 {
  83   u32 n_left_from, * from, * to_next;
  84   feat_bitmap_drop_next_t next_index;
  85
  86   from = vlib_frame_vector_args (frame);
  87   n_left_from = frame->n_vectors; /* number of packets to process */
  88   next_index = node->cached_next_index;
  89
  90   while (n_left_from > 0)
  91     {
  92       u32 n_left_to_next;
  93
  94       /* get space to enqueue frame to graph node "next_index" */
  95       vlib_get_next_frame (vm, node, next_index,
  96                            to_next, n_left_to_next);
  97
  98       while (n_left_from > 0 && n_left_to_next > 0)
  99         {
 100           u32 bi0;
 101           vlib_buffer_t * b0;
 102           u32 next0;
 103
 104           /* speculatively enqueue b0 to the current next frame */
 105           bi0 = from[0];
 106           to_next[0] = bi0;
 107           from += 1;
 108           to_next += 1;
 109           n_left_from -= 1;
 110           n_left_to_next -= 1;
 111
 112           b0 = vlib_get_buffer (vm, bi0);
 113
 114           if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE)
 115                             && (b0->flags & VLIB_BUFFER_IS_TRACED))) {
 116             feat_bitmap_drop_trace_t *t =
 117                vlib_add_trace (vm, node, b0, sizeof (*t));
 118             t->feature_bitmap = vnet_buffer(b0)->l2.feature_bitmap;
 119           }
 120
 121           if (vnet_buffer(b0)->l2.feature_bitmap == 1) {
 122             // If we are executing the last feature, this is the
 123             // No forwarding catch-all
 124             b0->error = node->errors[FEAT_BITMAP_DROP_ERROR_NO_FWD];
 125           } else {
 126             b0->error = node->errors[FEAT_BITMAP_DROP_ERROR_NYI];
 127           }
 128           next0 = FEAT_BITMAP_DROP_NEXT_DROP;
 129
 130           /* verify speculative enqueue, maybe switch current next frame */
 131           vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 132                                            to_next, n_left_to_next,
 133                                            bi0, next0);
 134         }
 135
 136       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 137     }
 138   return frame->n_vectors;
 139 }
 140
 141 clib_error_t *feat_bitmap_drop_init (vlib_main_t *vm)
 142 {
 143   return 0;
 144 }
 145
 146 VLIB_INIT_FUNCTION (feat_bitmap_drop_init);
 147
 148 VLIB_REGISTER_NODE (feat_bitmap_drop_node,static) = {
 149   .function = feat_bitmap_drop_node_fn,
 150   .name = "feature-bitmap-drop",
 151   .vector_size = sizeof (u32),
 152   .format_trace = format_feat_bitmap_drop_trace,
 153   .type = VLIB_NODE_TYPE_INTERNAL,
 154
 155   .n_errors = ARRAY_LEN(feat_bitmap_drop_error_strings),
 156   .error_strings = feat_bitmap_drop_error_strings,
 157
 158   .n_next_nodes = FEAT_BITMAP_DROP_N_NEXT,
 159
 160   /* edit / add dispositions here */
 161   .next_nodes = {
 162        [FEAT_BITMAP_DROP_NEXT_DROP]  = "error-drop",
 163   },
 164 };
 165
 166