lib/classifier-private.h

   1 /*
   2  * Copyright (c) 2014, 2015 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];  /* u64 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 "cls_match"es. */
  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     bool visible;
  83     const struct cls_rule *cls_rule;
  84     OVSRCU_TYPE(struct cls_conjunction_set *) conj_set;
  85     const struct miniflow flow; /* Matching rule. Mask is in the subtable. */
  86     /* 'flow' must be the last field. */
  87 };
  88
  89 /* A longest-prefix match tree. */
  90 struct trie_node {
  91     uint32_t prefix;           /* Prefix bits for this node, MSB first. */
  92     uint8_t  n_bits;           /* Never zero, except for the root node. */
  93     unsigned int n_rules;      /* Number of rules that have this prefix. */
  94     rcu_trie_ptr edges[2];     /* Both NULL if leaf. */
  95 };
  96
  97 /* Max bits per node.  Must fit in struct trie_node's 'prefix'.
  98  * Also tested with 16, 8, and 5 to stress the implementation. */
  99 #define TRIE_PREFIX_BITS 32
 100 \f
 101 /* flow/miniflow/minimask/minimatch utilities.
 102  * These are only used by the classifier, so place them here to allow
 103  * for better optimization. */
 104
 105 static inline uint64_t
 106 miniflow_get_map_in_range(const struct miniflow *miniflow,
 107                           uint8_t start, uint8_t end, unsigned int *offset)
 108 {
 109     uint64_t map = miniflow->map;
 110     *offset = 0;
 111
 112     if (start > 0) {
 113         uint64_t msk = (UINT64_C(1) << start) - 1; /* 'start' LSBs set */
 114         *offset = count_1bits(map & msk);
 115         map &= ~msk;
 116     }
 117     if (end < FLOW_U64S) {
 118         uint64_t msk = (UINT64_C(1) << end) - 1; /* 'end' LSBs set */
 119         map &= msk;
 120     }
 121     return map;
 122 }
 123
 124 /* Returns a hash value for the bits of 'flow' where there are 1-bits in
 125  * 'mask', given 'basis'.
 126  *
 127  * The hash values returned by this function are the same as those returned by
 128  * miniflow_hash_in_minimask(), only the form of the arguments differ. */
 129 static inline uint32_t
 130 flow_hash_in_minimask(const struct flow *flow, const struct minimask *mask,
 131                       uint32_t basis)
 132 {
 133     const uint64_t *mask_values = miniflow_get_values(&mask->masks);
 134     const uint64_t *flow_u64 = (const uint64_t *)flow;
 135     const uint64_t *p = mask_values;
 136     uint32_t hash;
 137     int idx;
 138
 139     hash = basis;
 140     MAP_FOR_EACH_INDEX(idx, mask->masks.map) {
 141         hash = hash_add64(hash, flow_u64[idx] & *p++);
 142     }
 143
 144     return hash_finish(hash, (p - mask_values) * 8);
 145 }
 146
 147 /* Returns a hash value for the bits of 'flow' where there are 1-bits in
 148  * 'mask', given 'basis'.
 149  *
 150  * The hash values returned by this function are the same as those returned by
 151  * flow_hash_in_minimask(), only the form of the arguments differ. */
 152 static inline uint32_t
 153 miniflow_hash_in_minimask(const struct miniflow *flow,
 154                           const struct minimask *mask, uint32_t basis)
 155 {
 156     const uint64_t *mask_values = miniflow_get_values(&mask->masks);
 157     const uint64_t *p = mask_values;
 158     uint32_t hash = basis;
 159     uint64_t flow_u64;
 160
 161     MINIFLOW_FOR_EACH_IN_MAP(flow_u64, flow, mask->masks.map) {
 162         hash = hash_add64(hash, flow_u64 & *p++);
 163     }
 164
 165     return hash_finish(hash, (p - mask_values) * 8);
 166 }
 167
 168 /* Returns a hash value for the bits of range [start, end) in 'flow',
 169  * where there are 1-bits in 'mask', given 'hash'.
 170  *
 171  * The hash values returned by this function are the same as those returned by
 172  * minimatch_hash_range(), only the form of the arguments differ. */
 173 static inline uint32_t
 174 flow_hash_in_minimask_range(const struct flow *flow,
 175                             const struct minimask *mask,
 176                             uint8_t start, uint8_t end, uint32_t *basis)
 177 {
 178     const uint64_t *mask_values = miniflow_get_values(&mask->masks);
 179     const uint64_t *flow_u64 = (const uint64_t *)flow;
 180     unsigned int offset;
 181     uint64_t map;
 182     const uint64_t *p;
 183     uint32_t hash = *basis;
 184     int idx;
 185
 186     map = miniflow_get_map_in_range(&mask->masks, start, end, &offset);
 187     p = mask_values + offset;
 188     MAP_FOR_EACH_INDEX(idx, map) {
 189         hash = hash_add64(hash, flow_u64[idx] & *p++);
 190     }
 191
 192     *basis = hash; /* Allow continuation from the unfinished value. */
 193     return hash_finish(hash, (p - mask_values) * 8);
 194 }
 195
 196 /* Fold minimask 'mask''s wildcard mask into 'wc's wildcard mask. */
 197 static inline void
 198 flow_wildcards_fold_minimask(struct flow_wildcards *wc,
 199                              const struct minimask *mask)
 200 {
 201     flow_union_with_miniflow(&wc->masks, &mask->masks);
 202 }
 203
 204 /* Fold minimask 'mask''s wildcard mask into 'wc's wildcard mask
 205  * in range [start, end). */
 206 static inline void
 207 flow_wildcards_fold_minimask_range(struct flow_wildcards *wc,
 208                                    const struct minimask *mask,
 209                                    uint8_t start, uint8_t end)
 210 {
 211     uint64_t *dst_u64 = (uint64_t *)&wc->masks;
 212     unsigned int offset;
 213     uint64_t map;
 214     const uint64_t *p;
 215     int idx;
 216
 217     map = miniflow_get_map_in_range(&mask->masks, start, end, &offset);
 218     p = miniflow_get_values(&mask->masks) + offset;
 219     MAP_FOR_EACH_INDEX(idx, map) {
 220         dst_u64[idx] |= *p++;
 221     }
 222 }
 223
 224 /* Returns a hash value for 'flow', given 'basis'. */
 225 static inline uint32_t
 226 miniflow_hash(const struct miniflow *flow, uint32_t basis)
 227 {
 228     const uint64_t *values = miniflow_get_values(flow);
 229     const uint64_t *p = values;
 230     uint32_t hash = basis;
 231     uint64_t hash_map = 0;
 232     uint64_t map;
 233
 234     for (map = flow->map; map; map = zero_rightmost_1bit(map)) {
 235         if (*p) {
 236             hash = hash_add64(hash, *p);
 237             hash_map |= rightmost_1bit(map);
 238         }
 239         p++;
 240     }
 241     hash = hash_add64(hash, hash_map);
 242
 243     return hash_finish(hash, p - values);
 244 }
 245
 246 /* Returns a hash value for 'mask', given 'basis'. */
 247 static inline uint32_t
 248 minimask_hash(const struct minimask *mask, uint32_t basis)
 249 {
 250     return miniflow_hash(&mask->masks, basis);
 251 }
 252
 253 /* Returns a hash value for 'match', given 'basis'. */
 254 static inline uint32_t
 255 minimatch_hash(const struct minimatch *match, uint32_t basis)
 256 {
 257     return miniflow_hash(&match->flow, minimask_hash(&match->mask, basis));
 258 }
 259
 260 /* Returns a hash value for the bits of range [start, end) in 'minimatch',
 261  * given 'basis'.
 262  *
 263  * The hash values returned by this function are the same as those returned by
 264  * flow_hash_in_minimask_range(), only the form of the arguments differ. */
 265 static inline uint32_t
 266 minimatch_hash_range(const struct minimatch *match, uint8_t start, uint8_t end,
 267                      uint32_t *basis)
 268 {
 269     unsigned int offset;
 270     const uint64_t *p, *q;
 271     uint32_t hash = *basis;
 272     int n, i;
 273
 274     n = count_1bits(miniflow_get_map_in_range(&match->mask.masks, start, end,
 275                                               &offset));
 276     q = miniflow_get_values(&match->mask.masks) + offset;
 277     p = miniflow_get_values(&match->flow) + offset;
 278
 279     for (i = 0; i < n; i++) {
 280         hash = hash_add64(hash, p[i] & q[i]);
 281     }
 282     *basis = hash; /* Allow continuation from the unfinished value. */
 283     return hash_finish(hash, (offset + n) * 8);
 284 }
 285
 286 #endif