lib/flow.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011, 2012 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 #ifndef FLOW_H
  17 #define FLOW_H 1
  18
  19 #include <sys/types.h>
  20 #include <netinet/in.h>
  21 #include <stdbool.h>
  22 #include <stdint.h>
  23 #include <string.h>
  24 #include "openflow/nicira-ext.h"
  25 #include "openflow/openflow.h"
  26 #include "hash.h"
  27 #include "util.h"
  28
  29 struct dpif_flow_stats;
  30 struct ds;
  31 struct flow_wildcards;
  32 struct miniflow;
  33 struct minimask;
  34 struct ofpbuf;
  35
  36 /* This sequence number should be incremented whenever anything involving flows
  37  * or the wildcarding of flows changes.  This will cause build assertion
  38  * failures in places which likely need to be updated. */
  39 #define FLOW_WC_SEQ 18
  40
  41 #define FLOW_N_REGS 8
  42 BUILD_ASSERT_DECL(FLOW_N_REGS <= NXM_NX_MAX_REGS);
  43
  44 /* Used for struct flow's dl_type member for frames that have no Ethernet
  45  * type, that is, pure 802.2 frames. */
  46 #define FLOW_DL_TYPE_NONE 0x5ff
  47
  48 /* Fragment bits, used for IPv4 and IPv6, always zero for non-IP flows. */
  49 #define FLOW_NW_FRAG_ANY   (1 << 0) /* Set for any IP frag. */
  50 #define FLOW_NW_FRAG_LATER (1 << 1) /* Set for IP frag with nonzero offset. */
  51 #define FLOW_NW_FRAG_MASK  (FLOW_NW_FRAG_ANY | FLOW_NW_FRAG_LATER)
  52
  53 BUILD_ASSERT_DECL(FLOW_NW_FRAG_ANY == NX_IP_FRAG_ANY);
  54 BUILD_ASSERT_DECL(FLOW_NW_FRAG_LATER == NX_IP_FRAG_LATER);
  55
  56 #define FLOW_TNL_F_DONT_FRAGMENT (1 << 0)
  57 #define FLOW_TNL_F_CSUM (1 << 1)
  58 #define FLOW_TNL_F_KEY (1 << 2)
  59 struct flow_tnl {
  60     ovs_be64 tun_id;
  61     ovs_be32 ip_src;
  62     ovs_be32 ip_dst;
  63     uint16_t flags;
  64     uint8_t ip_tos;
  65     uint8_t ip_ttl;
  66 };
  67
  68 /*
  69 * A flow in the network.
  70 *
  71 * The meaning of 'in_port' is context-dependent.  In most cases, it is a
  72 * 16-bit OpenFlow 1.0 port number.  In the software datapath interface (dpif)
  73 * layer and its implementations (e.g. dpif-linux, dpif-netdev), it is instead
  74 * a 32-bit datapath port number.
  75 */
  76 struct flow {
  77     struct flow_tnl tunnel;     /* Encapsulating tunnel parameters. */
  78     ovs_be64 metadata;          /* OpenFlow Metadata. */
  79     struct in6_addr ipv6_src;   /* IPv6 source address. */
  80     struct in6_addr ipv6_dst;   /* IPv6 destination address. */
  81     struct in6_addr nd_target;  /* IPv6 neighbor discovery (ND) target. */
  82     uint32_t skb_priority;      /* Packet priority for QoS. */
  83     uint32_t regs[FLOW_N_REGS]; /* Registers. */
  84     ovs_be32 nw_src;            /* IPv4 source address. */
  85     ovs_be32 nw_dst;            /* IPv4 destination address. */
  86     ovs_be32 ipv6_label;        /* IPv6 flow label. */
  87     uint32_t in_port;           /* Input port. OpenFlow port number
  88                                    unless in DPIF code, in which case it
  89                                    is the datapath port number. */
  90     uint32_t skb_mark;          /* Packet mark. */
  91     ovs_be16 vlan_tci;          /* If 802.1Q, TCI | VLAN_CFI; otherwise 0. */
  92     ovs_be16 dl_type;           /* Ethernet frame type. */
  93     ovs_be16 tp_src;            /* TCP/UDP source port. */
  94     ovs_be16 tp_dst;            /* TCP/UDP destination port. */
  95     uint8_t dl_src[6];          /* Ethernet source address. */
  96     uint8_t dl_dst[6];          /* Ethernet destination address. */
  97     uint8_t nw_proto;           /* IP protocol or low 8 bits of ARP opcode. */
  98     uint8_t nw_tos;             /* IP ToS (including DSCP and ECN). */
  99     uint8_t arp_sha[6];         /* ARP/ND source hardware address. */
 100     uint8_t arp_tha[6];         /* ARP/ND target hardware address. */
 101     uint8_t nw_ttl;             /* IP TTL/Hop Limit. */
 102     uint8_t nw_frag;            /* FLOW_FRAG_* flags. */
 103 };
 104 BUILD_ASSERT_DECL(sizeof(struct flow) % 4 == 0);
 105
 106 #define FLOW_U32S (sizeof(struct flow) / 4)
 107
 108 /* Remember to update FLOW_WC_SEQ when changing 'struct flow'. */
 109 BUILD_ASSERT_DECL(sizeof(struct flow) == sizeof(struct flow_tnl) + 152 &&
 110                   FLOW_WC_SEQ == 18);
 111
 112 /* Represents the metadata fields of struct flow. */
 113 struct flow_metadata {
 114     ovs_be64 tun_id;                 /* Encapsulating tunnel ID. */
 115     ovs_be64 metadata;               /* OpenFlow 1.1+ metadata field. */
 116     uint32_t regs[FLOW_N_REGS];      /* Registers. */
 117     uint16_t in_port;                /* OpenFlow port or zero. */
 118 };
 119
 120 void flow_extract(struct ofpbuf *, uint32_t priority, uint32_t mark,
 121                   const struct flow_tnl *, uint16_t in_port, struct flow *);
 122 void flow_zero_wildcards(struct flow *, const struct flow_wildcards *);
 123 void flow_get_metadata(const struct flow *, struct flow_metadata *);
 124
 125 char *flow_to_string(const struct flow *);
 126 void flow_format(struct ds *, const struct flow *);
 127 void flow_print(FILE *, const struct flow *);
 128 static inline int flow_compare_3way(const struct flow *, const struct flow *);
 129 static inline bool flow_equal(const struct flow *, const struct flow *);
 130 static inline size_t flow_hash(const struct flow *, uint32_t basis);
 131
 132 void flow_set_dl_vlan(struct flow *, ovs_be16 vid);
 133 void flow_set_vlan_vid(struct flow *, ovs_be16 vid);
 134 void flow_set_vlan_pcp(struct flow *, uint8_t pcp);
 135
 136 void flow_compose(struct ofpbuf *, const struct flow *);
 137
 138 static inline int
 139 flow_compare_3way(const struct flow *a, const struct flow *b)
 140 {
 141     return memcmp(a, b, sizeof *a);
 142 }
 143
 144 static inline bool
 145 flow_equal(const struct flow *a, const struct flow *b)
 146 {
 147     return !flow_compare_3way(a, b);
 148 }
 149
 150 static inline size_t
 151 flow_hash(const struct flow *flow, uint32_t basis)
 152 {
 153     return hash_words((const uint32_t *) flow, sizeof *flow / 4, basis);
 154 }
 155
 156 uint32_t flow_hash_in_minimask(const struct flow *, const struct minimask *,
 157                                uint32_t basis);
 158 \f
 159 /* Wildcards for a flow.
 160  *
 161  * A 1-bit in each bit in 'masks' indicates that the corresponding bit of
 162  * the flow is significant (must match).  A 0-bit indicates that the
 163  * corresponding bit of the flow is wildcarded (need not match). */
 164 struct flow_wildcards {
 165     struct flow masks;
 166 };
 167
 168 void flow_wildcards_init_catchall(struct flow_wildcards *);
 169 void flow_wildcards_init_exact(struct flow_wildcards *);
 170
 171 bool flow_wildcards_is_catchall(const struct flow_wildcards *);
 172
 173 void flow_wildcards_set_reg_mask(struct flow_wildcards *,
 174                                  int idx, uint32_t mask);
 175
 176 void flow_wildcards_combine(struct flow_wildcards *dst,
 177                             const struct flow_wildcards *src1,
 178                             const struct flow_wildcards *src2);
 179 bool flow_wildcards_has_extra(const struct flow_wildcards *,
 180                               const struct flow_wildcards *);
 181
 182 uint32_t flow_wildcards_hash(const struct flow_wildcards *, uint32_t basis);
 183 bool flow_wildcards_equal(const struct flow_wildcards *,
 184                           const struct flow_wildcards *);
 185 uint32_t flow_hash_symmetric_l4(const struct flow *flow, uint32_t basis);
 186
 187 uint32_t flow_hash_fields(const struct flow *, enum nx_hash_fields,
 188                           uint16_t basis);
 189 const char *flow_hash_fields_to_str(enum nx_hash_fields);
 190 bool flow_hash_fields_valid(enum nx_hash_fields);
 191
 192 bool flow_equal_except(const struct flow *a, const struct flow *b,
 193                        const struct flow_wildcards *);
 194 \f
 195 /* Compressed flow. */
 196
 197 #define MINI_N_INLINE (sizeof(void *) == 4 ? 7 : 8)
 198 #define MINI_N_MAPS DIV_ROUND_UP(FLOW_U32S, 32)
 199
 200 /* A sparse representation of a "struct flow".
 201  *
 202  * A "struct flow" is fairly large and tends to be mostly zeros.  Sparse
 203  * representation has two advantages.  First, it saves memory.  Second, it
 204  * saves time when the goal is to iterate over only the nonzero parts of the
 205  * struct.
 206  *
 207  * The 'map' member holds one bit for each uint32_t in a "struct flow".  Each
 208  * 0-bit indicates that the corresponding uint32_t is zero, each 1-bit that it
 209  * is nonzero.
 210  *
 211  * 'values' points to the start of an array that has one element for each 1-bit
 212  * in 'map'.  The least-numbered 1-bit is in values[0], the next 1-bit is in
 213  * values[1], and so on.
 214  *
 215  * 'values' may point to a few different locations:
 216  *
 217  *     - If 'map' has MINI_N_INLINE or fewer 1-bits, it may point to
 218  *       'inline_values'.  One hopes that this is the common case.
 219  *
 220  *     - If 'map' has more than MINI_N_INLINE 1-bits, it may point to memory
 221  *       allocated with malloc().
 222  *
 223  *     - The caller could provide storage on the stack for situations where
 224  *       that makes sense.  So far that's only proved useful for
 225  *       minimask_combine(), but the principle works elsewhere.
 226  *
 227  * The implementation maintains and depends on the invariant that every element
 228  * in 'values' is nonzero; that is, wherever a 1-bit appears in 'map', the
 229  * corresponding element of 'values' must be nonzero.
 230  */
 231 struct miniflow {
 232     uint32_t *values;
 233     uint32_t inline_values[MINI_N_INLINE];
 234     uint32_t map[MINI_N_MAPS];
 235 };
 236
 237 void miniflow_init(struct miniflow *, const struct flow *);
 238 void miniflow_clone(struct miniflow *, const struct miniflow *);
 239 void miniflow_destroy(struct miniflow *);
 240
 241 void miniflow_expand(const struct miniflow *, struct flow *);
 242
 243 uint32_t miniflow_get(const struct miniflow *, unsigned int u32_ofs);
 244 uint16_t miniflow_get_vid(const struct miniflow *);
 245
 246 bool miniflow_equal(const struct miniflow *a, const struct miniflow *b);
 247 bool miniflow_equal_in_minimask(const struct miniflow *a,
 248                                 const struct miniflow *b,
 249                                 const struct minimask *);
 250 bool miniflow_equal_flow_in_minimask(const struct miniflow *a,
 251                                      const struct flow *b,
 252                                      const struct minimask *);
 253 uint32_t miniflow_hash(const struct miniflow *, uint32_t basis);
 254 uint32_t miniflow_hash_in_minimask(const struct miniflow *,
 255                                    const struct minimask *, uint32_t basis);
 256 \f
 257 /* Compressed flow wildcards. */
 258
 259 /* A sparse representation of a "struct flow_wildcards".
 260  *
 261  * See the large comment on struct miniflow for details. */
 262 struct minimask {
 263     struct miniflow masks;
 264 };
 265
 266 void minimask_init(struct minimask *, const struct flow_wildcards *);
 267 void minimask_clone(struct minimask *, const struct minimask *);
 268 void minimask_combine(struct minimask *dst,
 269                       const struct minimask *a, const struct minimask *b,
 270                       uint32_t storage[FLOW_U32S]);
 271 void minimask_destroy(struct minimask *);
 272
 273 void minimask_expand(const struct minimask *, struct flow_wildcards *);
 274
 275 uint32_t minimask_get(const struct minimask *, unsigned int u32_ofs);
 276 uint16_t minimask_get_vid_mask(const struct minimask *);
 277
 278 bool minimask_equal(const struct minimask *a, const struct minimask *b);
 279 uint32_t minimask_hash(const struct minimask *, uint32_t basis);
 280
 281 bool minimask_has_extra(const struct minimask *, const struct minimask *);
 282 bool minimask_is_catchall(const struct minimask *);
 283
 284 #endif /* flow.h */