lib/classifier-private.h

   1 /*
   2  * Copyright (c) 2014 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #ifndef CLASSIFIER_PRIVATE_H
  18 #define CLASSIFIER_PRIVATE_H 1
  19
  20 #include "cmap.h"
  21 #include "flow.h"
  22 #include "hash.h"
  23 #include "rculist.h"
  24 #include "tag.h"
  25
  26 /* Classifier internal definitions, subject to change at any time. */
  27
  28 /* A set of rules that all have the same fields wildcarded. */
  29 struct cls_subtable {
  30     struct cmap_node cmap_node;    /* Within classifier's 'subtables_map'. */
  31
  32     /* These fields are only used by writers. */
  33     int max_priority;              /* Max priority of any rule in subtable. */
  34     unsigned int max_count;        /* Count of max_priority rules. */
  35
  36     /* Accessed by iterators. */
  37     struct rculist rules_list;              /* Unordered. */
  38
  39     /* Identical, but lower priority rules are not inserted to any of the
  40      * following data structures. */
  41
  42     /* These fields are accessed by readers who care about wildcarding. */
  43     const tag_type tag;       /* Tag generated from mask for partitioning. */
  44     const uint8_t n_indices;                   /* How many indices to use. */
  45     const uint8_t index_ofs[CLS_MAX_INDICES];  /* u32 segment boundaries. */
  46     unsigned int trie_plen[CLS_MAX_TRIES];  /* Trie prefix length in 'mask'
  47                                              * (runtime configurable). */
  48     const int ports_mask_len;
  49     struct cmap indices[CLS_MAX_INDICES];   /* Staged lookup indices. */
  50     rcu_trie_ptr ports_trie;                /* NULL if none. */
  51
  52     /* These fields are accessed by all readers. */
  53     struct cmap rules;                      /* Contains 'cls_match'es. */
  54     const struct minimask mask;             /* Wildcards for fields. */
  55     /* 'mask' must be the last field. */
  56 };
  57
  58 /* Associates a metadata value (that is, a value of the OpenFlow 1.1+ metadata
  59  * field) with tags for the "cls_subtable"s that contain rules that match that
  60  * metadata value.  */
  61 struct cls_partition {
  62     struct cmap_node cmap_node; /* In struct classifier's 'partitions' map. */
  63     ovs_be64 metadata;          /* metadata value for this partition. */
  64     tag_type tags;              /* OR of each flow's cls_subtable tag. */
  65     struct tag_tracker tracker; /* Tracks the bits in 'tags'. */
  66 };
  67
  68 /* Internal representation of a rule in a "struct cls_subtable". */
  69 struct cls_match {
  70     /* Accessed by everybody. */
  71     struct rculist list; /* Identical, lower-priority rules. */
  72
  73     /* Accessed only by writers. */
  74     struct cls_partition *partition;
  75
  76     /* Accessed by readers interested in wildcarding. */
  77     const int priority;         /* Larger numbers are higher priorities. */
  78     struct cmap_node index_nodes[CLS_MAX_INDICES]; /* Within subtable's
  79                                                     * 'indices'. */
  80     /* Accessed by all readers. */
  81     struct cmap_node cmap_node; /* Within struct cls_subtable 'rules'. */
  82     const struct cls_rule *cls_rule;
  83     const struct miniflow flow; /* Matching rule. Mask is in the subtable. */
  84     /* 'flow' must be the last field. */
  85 };
  86
  87 /* A longest-prefix match tree. */
  88 struct trie_node {
  89     uint32_t prefix;           /* Prefix bits for this node, MSB first. */
  90     uint8_t  n_bits;           /* Never zero, except for the root node. */
  91     unsigned int n_rules;      /* Number of rules that have this prefix. */
  92     rcu_trie_ptr edges[2];     /* Both NULL if leaf. */
  93 };
  94
  95 /* Max bits per node.  Must fit in struct trie_node's 'prefix'.
  96  * Also tested with 16, 8, and 5 to stress the implementation. */
  97 #define TRIE_PREFIX_BITS 32
  98 \f
  99 /* flow/miniflow/minimask/minimatch utilities.
 100  * These are only used by the classifier, so place them here to allow
 101  * for better optimization. */
 102
 103 static inline uint64_t
 104 miniflow_get_map_in_range(const struct miniflow *miniflow,
 105                           uint8_t start, uint8_t end, unsigned int *offset)
 106 {
 107     uint64_t map = miniflow->map;
 108     *offset = 0;
 109
 110     if (start > 0) {
 111         uint64_t msk = (UINT64_C(1) << start) - 1; /* 'start' LSBs set */
 112         *offset = count_1bits(map & msk);
 113         map &= ~msk;
 114     }
 115     if (end < FLOW_U32S) {
 116         uint64_t msk = (UINT64_C(1) << end) - 1; /* 'end' LSBs set */
 117         map &= msk;
 118     }
 119     return map;
 120 }
 121
 122 /* Returns a hash value for the bits of 'flow' where there are 1-bits in
 123  * 'mask', given 'basis'.
 124  *
 125  * The hash values returned by this function are the same as those returned by
 126  * miniflow_hash_in_minimask(), only the form of the arguments differ. */
 127 static inline uint32_t
 128 flow_hash_in_minimask(const struct flow *flow, const struct minimask *mask,
 129                       uint32_t basis)
 130 {
 131     const uint32_t *mask_values = miniflow_get_u32_values(&mask->masks);
 132     const uint32_t *flow_u32 = (const uint32_t *)flow;
 133     const uint32_t *p = mask_values;
 134     uint32_t hash;
 135     int idx;
 136
 137     hash = basis;
 138     MAP_FOR_EACH_INDEX(idx, mask->masks.map) {
 139         hash = hash_add(hash, flow_u32[idx] & *p++);
 140     }
 141
 142     return hash_finish(hash, (p - mask_values) * 4);
 143 }
 144
 145 /* Returns a hash value for the bits of 'flow' where there are 1-bits in
 146  * 'mask', given 'basis'.
 147  *
 148  * The hash values returned by this function are the same as those returned by
 149  * flow_hash_in_minimask(), only the form of the arguments differ. */
 150 static inline uint32_t
 151 miniflow_hash_in_minimask(const struct miniflow *flow,
 152                           const struct minimask *mask, uint32_t basis)
 153 {
 154     const uint32_t *mask_values = miniflow_get_u32_values(&mask->masks);
 155     const uint32_t *p = mask_values;
 156     uint32_t hash = basis;
 157     uint32_t flow_u32;
 158
 159     MINIFLOW_FOR_EACH_IN_MAP(flow_u32, flow, mask->masks.map) {
 160         hash = hash_add(hash, flow_u32 & *p++);
 161     }
 162
 163     return hash_finish(hash, (p - mask_values) * 4);
 164 }
 165
 166 /* Returns a hash value for the bits of range [start, end) in 'flow',
 167  * where there are 1-bits in 'mask', given 'hash'.
 168  *
 169  * The hash values returned by this function are the same as those returned by
 170  * minimatch_hash_range(), only the form of the arguments differ. */
 171 static inline uint32_t
 172 flow_hash_in_minimask_range(const struct flow *flow,
 173                             const struct minimask *mask,
 174                             uint8_t start, uint8_t end, uint32_t *basis)
 175 {
 176     const uint32_t *mask_values = miniflow_get_u32_values(&mask->masks);
 177     const uint32_t *flow_u32 = (const uint32_t *)flow;
 178     unsigned int offset;
 179     uint64_t map;
 180     const uint32_t *p;
 181     uint32_t hash = *basis;
 182     int idx;
 183
 184     map = miniflow_get_map_in_range(&mask->masks, start, end, &offset);
 185     p = mask_values + offset;
 186     MAP_FOR_EACH_INDEX(idx, map) {
 187         hash = hash_add(hash, flow_u32[idx] & *p++);
 188     }
 189
 190     *basis = hash; /* Allow continuation from the unfinished value. */
 191     return hash_finish(hash, (p - mask_values) * 4);
 192 }
 193
 194 /* Fold minimask 'mask''s wildcard mask into 'wc's wildcard mask. */
 195 static inline void
 196 flow_wildcards_fold_minimask(struct flow_wildcards *wc,
 197                              const struct minimask *mask)
 198 {
 199     flow_union_with_miniflow(&wc->masks, &mask->masks);
 200 }
 201
 202 /* Fold minimask 'mask''s wildcard mask into 'wc's wildcard mask
 203  * in range [start, end). */
 204 static inline void
 205 flow_wildcards_fold_minimask_range(struct flow_wildcards *wc,
 206                                    const struct minimask *mask,
 207                                    uint8_t start, uint8_t end)
 208 {
 209     uint32_t *dst_u32 = (uint32_t *)&wc->masks;
 210     unsigned int offset;
 211     uint64_t map;
 212     const uint32_t *p;
 213     int idx;
 214
 215     map = miniflow_get_map_in_range(&mask->masks, start, end, &offset);
 216     p = miniflow_get_u32_values(&mask->masks) + offset;
 217     MAP_FOR_EACH_INDEX(idx, map) {
 218         dst_u32[idx] |= *p++;
 219     }
 220 }
 221
 222 /* Returns a hash value for 'flow', given 'basis'. */
 223 static inline uint32_t
 224 miniflow_hash(const struct miniflow *flow, uint32_t basis)
 225 {
 226     const uint32_t *values = miniflow_get_u32_values(flow);
 227     const uint32_t *p = values;
 228     uint32_t hash = basis;
 229     uint64_t hash_map = 0;
 230     uint64_t map;
 231
 232     for (map = flow->map; map; map = zero_rightmost_1bit(map)) {
 233         if (*p) {
 234             hash = hash_add(hash, *p);
 235             hash_map |= rightmost_1bit(map);
 236         }
 237         p++;
 238     }
 239     hash = hash_add(hash, hash_map);
 240     hash = hash_add(hash, hash_map >> 32);
 241
 242     return hash_finish(hash, p - values);
 243 }
 244
 245 /* Returns a hash value for 'mask', given 'basis'. */
 246 static inline uint32_t
 247 minimask_hash(const struct minimask *mask, uint32_t basis)
 248 {
 249     return miniflow_hash(&mask->masks, basis);
 250 }
 251
 252 /* Returns a hash value for 'match', given 'basis'. */
 253 static inline uint32_t
 254 minimatch_hash(const struct minimatch *match, uint32_t basis)
 255 {
 256     return miniflow_hash(&match->flow, minimask_hash(&match->mask, basis));
 257 }
 258
 259 /* Returns a hash value for the bits of range [start, end) in 'minimatch',
 260  * given 'basis'.
 261  *
 262  * The hash values returned by this function are the same as those returned by
 263  * flow_hash_in_minimask_range(), only the form of the arguments differ. */
 264 static inline uint32_t
 265 minimatch_hash_range(const struct minimatch *match, uint8_t start, uint8_t end,
 266                      uint32_t *basis)
 267 {
 268     unsigned int offset;
 269     const uint32_t *p, *q;
 270     uint32_t hash = *basis;
 271     int n, i;
 272
 273     n = count_1bits(miniflow_get_map_in_range(&match->mask.masks, start, end,
 274                                               &offset));
 275     q = miniflow_get_u32_values(&match->mask.masks) + offset;
 276     p = miniflow_get_u32_values(&match->flow) + offset;
 277
 278     for (i = 0; i < n; i++) {
 279         hash = hash_add(hash, p[i] & q[i]);
 280     }
 281     *basis = hash; /* Allow continuation from the unfinished value. */
 282     return hash_finish(hash, (offset + n) * 4);
 283 }
 284
 285 #endif