lib/flow.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 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 20
  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
  60 const char *flow_tun_flag_to_string(uint32_t flags);
  61
  62 struct flow_tnl {
  63     ovs_be64 tun_id;
  64     ovs_be32 ip_src;
  65     ovs_be32 ip_dst;
  66     uint16_t flags;
  67     uint8_t ip_tos;
  68     uint8_t ip_ttl;
  69 };
  70
  71 /*
  72 * A flow in the network.
  73 *
  74 * The meaning of 'in_port' is context-dependent.  In most cases, it is a
  75 * 16-bit OpenFlow 1.0 port number.  In the software datapath interface (dpif)
  76 * layer and its implementations (e.g. dpif-linux, dpif-netdev), it is instead
  77 * a 32-bit datapath port number.
  78 */
  79 struct flow {
  80     struct flow_tnl tunnel;     /* Encapsulating tunnel parameters. */
  81     ovs_be64 metadata;          /* OpenFlow Metadata. */
  82     struct in6_addr ipv6_src;   /* IPv6 source address. */
  83     struct in6_addr ipv6_dst;   /* IPv6 destination address. */
  84     struct in6_addr nd_target;  /* IPv6 neighbor discovery (ND) target. */
  85     uint32_t skb_priority;      /* Packet priority for QoS. */
  86     uint32_t regs[FLOW_N_REGS]; /* Registers. */
  87     ovs_be32 nw_src;            /* IPv4 source address. */
  88     ovs_be32 nw_dst;            /* IPv4 destination address. */
  89     ovs_be32 ipv6_label;        /* IPv6 flow label. */
  90     uint32_t in_port;           /* Input port. OpenFlow port number
  91                                    unless in DPIF code, in which case it
  92                                    is the datapath port number. */
  93     uint32_t skb_mark;          /* Packet mark. */
  94     ovs_be32 mpls_lse;          /* MPLS label stack entry. */
  95     uint16_t mpls_depth;        /* Depth of MPLS stack. */
  96     ovs_be16 vlan_tci;          /* If 802.1Q, TCI | VLAN_CFI; otherwise 0. */
  97     ovs_be16 dl_type;           /* Ethernet frame type. */
  98     ovs_be16 tp_src;            /* TCP/UDP source port. */
  99     ovs_be16 tp_dst;            /* TCP/UDP destination port. */
 100     uint8_t dl_src[6];          /* Ethernet source address. */
 101     uint8_t dl_dst[6];          /* Ethernet destination address. */
 102     uint8_t nw_proto;           /* IP protocol or low 8 bits of ARP opcode. */
 103     uint8_t nw_tos;             /* IP ToS (including DSCP and ECN). */
 104     uint8_t arp_sha[6];         /* ARP/ND source hardware address. */
 105     uint8_t arp_tha[6];         /* ARP/ND target hardware address. */
 106     uint8_t nw_ttl;             /* IP TTL/Hop Limit. */
 107     uint8_t nw_frag;            /* FLOW_FRAG_* flags. */
 108     uint8_t zeros[6];
 109 };
 110 BUILD_ASSERT_DECL(sizeof(struct flow) % 4 == 0);
 111
 112 #define FLOW_U32S (sizeof(struct flow) / 4)
 113
 114 /* Remember to update FLOW_WC_SEQ when changing 'struct flow'. */
 115 BUILD_ASSERT_DECL(sizeof(struct flow) == sizeof(struct flow_tnl) + 160 &&
 116                   FLOW_WC_SEQ == 20);
 117
 118 /* Represents the metadata fields of struct flow. */
 119 struct flow_metadata {
 120     ovs_be64 tun_id;                 /* Encapsulating tunnel ID. */
 121     ovs_be32 tun_src;                /* Tunnel outer IPv4 src addr */
 122     ovs_be32 tun_dst;                /* Tunnel outer IPv4 dst addr */
 123     ovs_be64 metadata;               /* OpenFlow 1.1+ metadata field. */
 124     uint32_t regs[FLOW_N_REGS];      /* Registers. */
 125     uint16_t in_port;                /* OpenFlow port or zero. */
 126 };
 127
 128 void flow_extract(struct ofpbuf *, uint32_t priority, uint32_t mark,
 129                   const struct flow_tnl *, uint16_t in_port, struct flow *);
 130
 131 void flow_zero_wildcards(struct flow *, const struct flow_wildcards *);
 132 void flow_get_metadata(const struct flow *, struct flow_metadata *);
 133
 134 char *flow_to_string(const struct flow *);
 135 void format_flags(struct ds *ds, const char *(*bit_to_string)(uint32_t),
 136                   uint32_t flags, char del);
 137
 138 void flow_format(struct ds *, const struct flow *);
 139 void flow_print(FILE *, const struct flow *);
 140 static inline int flow_compare_3way(const struct flow *, const struct flow *);
 141 static inline bool flow_equal(const struct flow *, const struct flow *);
 142 static inline size_t flow_hash(const struct flow *, uint32_t basis);
 143
 144 void flow_set_dl_vlan(struct flow *, ovs_be16 vid);
 145 void flow_set_vlan_vid(struct flow *, ovs_be16 vid);
 146 void flow_set_vlan_pcp(struct flow *, uint8_t pcp);
 147
 148 void flow_set_mpls_label(struct flow *flow, ovs_be32 label);
 149 void flow_set_mpls_ttl(struct flow *flow, uint8_t ttl);
 150 void flow_set_mpls_tc(struct flow *flow, uint8_t tc);
 151 void flow_set_mpls_bos(struct flow *flow, uint8_t stack);
 152
 153 void flow_compose(struct ofpbuf *, const struct flow *);
 154
 155 static inline int
 156 flow_compare_3way(const struct flow *a, const struct flow *b)
 157 {
 158     return memcmp(a, b, sizeof *a);
 159 }
 160
 161 static inline bool
 162 flow_equal(const struct flow *a, const struct flow *b)
 163 {
 164     return !flow_compare_3way(a, b);
 165 }
 166
 167 static inline size_t
 168 flow_hash(const struct flow *flow, uint32_t basis)
 169 {
 170     return hash_words((const uint32_t *) flow, sizeof *flow / 4, basis);
 171 }
 172
 173 uint32_t flow_hash_in_minimask(const struct flow *, const struct minimask *,
 174                                uint32_t basis);
 175 \f
 176 /* Wildcards for a flow.
 177  *
 178  * A 1-bit in each bit in 'masks' indicates that the corresponding bit of
 179  * the flow is significant (must match).  A 0-bit indicates that the
 180  * corresponding bit of the flow is wildcarded (need not match). */
 181 struct flow_wildcards {
 182     struct flow masks;
 183 };
 184
 185 void flow_wildcards_init_catchall(struct flow_wildcards *);
 186 void flow_wildcards_init_exact(struct flow_wildcards *);
 187
 188 bool flow_wildcards_is_catchall(const struct flow_wildcards *);
 189
 190 void flow_wildcards_set_reg_mask(struct flow_wildcards *,
 191                                  int idx, uint32_t mask);
 192
 193 void flow_wildcards_and(struct flow_wildcards *dst,
 194                         const struct flow_wildcards *src1,
 195                         const struct flow_wildcards *src2);
 196 void flow_wildcards_or(struct flow_wildcards *dst,
 197                        const struct flow_wildcards *src1,
 198                        const struct flow_wildcards *src2);
 199 bool flow_wildcards_has_extra(const struct flow_wildcards *,
 200                               const struct flow_wildcards *);
 201
 202 void flow_wildcards_fold_minimask(struct flow_wildcards *,
 203                                   const struct minimask *);
 204
 205 uint32_t flow_wildcards_hash(const struct flow_wildcards *, uint32_t basis);
 206 bool flow_wildcards_equal(const struct flow_wildcards *,
 207                           const struct flow_wildcards *);
 208 uint32_t flow_hash_symmetric_l4(const struct flow *flow, uint32_t basis);
 209
 210 void flow_mask_hash_fields(struct flow_wildcards *, enum nx_hash_fields);
 211 uint32_t flow_hash_fields(const struct flow *, enum nx_hash_fields,
 212                           uint16_t basis);
 213 const char *flow_hash_fields_to_str(enum nx_hash_fields);
 214 bool flow_hash_fields_valid(enum nx_hash_fields);
 215
 216 uint32_t flow_hash_in_wildcards(const struct flow *,
 217                                 const struct flow_wildcards *,
 218                                 uint32_t basis);
 219
 220 bool flow_equal_except(const struct flow *a, const struct flow *b,
 221                        const struct flow_wildcards *);
 222 \f
 223 /* Compressed flow. */
 224
 225 #define MINI_N_INLINE (sizeof(void *) == 4 ? 7 : 8)
 226 #define MINI_N_MAPS DIV_ROUND_UP(FLOW_U32S, 32)
 227
 228 /* A sparse representation of a "struct flow".
 229  *
 230  * A "struct flow" is fairly large and tends to be mostly zeros.  Sparse
 231  * representation has two advantages.  First, it saves memory.  Second, it
 232  * saves time when the goal is to iterate over only the nonzero parts of the
 233  * struct.
 234  *
 235  * The 'map' member holds one bit for each uint32_t in a "struct flow".  Each
 236  * 0-bit indicates that the corresponding uint32_t is zero, each 1-bit that it
 237  * is nonzero.
 238  *
 239  * 'values' points to the start of an array that has one element for each 1-bit
 240  * in 'map'.  The least-numbered 1-bit is in values[0], the next 1-bit is in
 241  * values[1], and so on.
 242  *
 243  * 'values' may point to a few different locations:
 244  *
 245  *     - If 'map' has MINI_N_INLINE or fewer 1-bits, it may point to
 246  *       'inline_values'.  One hopes that this is the common case.
 247  *
 248  *     - If 'map' has more than MINI_N_INLINE 1-bits, it may point to memory
 249  *       allocated with malloc().
 250  *
 251  *     - The caller could provide storage on the stack for situations where
 252  *       that makes sense.  So far that's only proved useful for
 253  *       minimask_combine(), but the principle works elsewhere.
 254  *
 255  * The implementation maintains and depends on the invariant that every element
 256  * in 'values' is nonzero; that is, wherever a 1-bit appears in 'map', the
 257  * corresponding element of 'values' must be nonzero.
 258  */
 259 struct miniflow {
 260     uint32_t *values;
 261     uint32_t inline_values[MINI_N_INLINE];
 262     uint32_t map[MINI_N_MAPS];
 263 };
 264
 265 void miniflow_init(struct miniflow *, const struct flow *);
 266 void miniflow_clone(struct miniflow *, const struct miniflow *);
 267 void miniflow_destroy(struct miniflow *);
 268
 269 void miniflow_expand(const struct miniflow *, struct flow *);
 270
 271 uint32_t miniflow_get(const struct miniflow *, unsigned int u32_ofs);
 272 uint16_t miniflow_get_vid(const struct miniflow *);
 273
 274 bool miniflow_equal(const struct miniflow *a, const struct miniflow *b);
 275 bool miniflow_equal_in_minimask(const struct miniflow *a,
 276                                 const struct miniflow *b,
 277                                 const struct minimask *);
 278 bool miniflow_equal_flow_in_minimask(const struct miniflow *a,
 279                                      const struct flow *b,
 280                                      const struct minimask *);
 281 uint32_t miniflow_hash(const struct miniflow *, uint32_t basis);
 282 uint32_t miniflow_hash_in_minimask(const struct miniflow *,
 283                                    const struct minimask *, uint32_t basis);
 284 \f
 285 /* Compressed flow wildcards. */
 286
 287 /* A sparse representation of a "struct flow_wildcards".
 288  *
 289  * See the large comment on struct miniflow for details. */
 290 struct minimask {
 291     struct miniflow masks;
 292 };
 293
 294 void minimask_init(struct minimask *, const struct flow_wildcards *);
 295 void minimask_clone(struct minimask *, const struct minimask *);
 296 void minimask_combine(struct minimask *dst,
 297                       const struct minimask *a, const struct minimask *b,
 298                       uint32_t storage[FLOW_U32S]);
 299 void minimask_destroy(struct minimask *);
 300
 301 void minimask_expand(const struct minimask *, struct flow_wildcards *);
 302
 303 uint32_t minimask_get(const struct minimask *, unsigned int u32_ofs);
 304 uint16_t minimask_get_vid_mask(const struct minimask *);
 305
 306 bool minimask_equal(const struct minimask *a, const struct minimask *b);
 307 uint32_t minimask_hash(const struct minimask *, uint32_t basis);
 308
 309 bool minimask_has_extra(const struct minimask *, const struct minimask *);
 310 bool minimask_is_catchall(const struct minimask *);
 311
 312 #endif /* flow.h */