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 /* Unfortunately, a "struct flow" sometimes has to handle OpenFlow port
  72  * numbers and other times datapath (dpif) port numbers.  This union allows
  73  * access to both. */
  74 union flow_in_port {
  75     ofp_port_t ofp_port;
  76     odp_port_t odp_port;
  77 };
  78
  79 /*
  80 * A flow in the network.
  81 *
  82 * The meaning of 'in_port' is context-dependent.  In most cases, it is a
  83 * 16-bit OpenFlow 1.0 port number.  In the software datapath interface (dpif)
  84 * layer and its implementations (e.g. dpif-linux, dpif-netdev), it is instead
  85 * a 32-bit datapath port number.
  86 */
  87 struct flow {
  88     struct flow_tnl tunnel;     /* Encapsulating tunnel parameters. */
  89     ovs_be64 metadata;          /* OpenFlow Metadata. */
  90     struct in6_addr ipv6_src;   /* IPv6 source address. */
  91     struct in6_addr ipv6_dst;   /* IPv6 destination address. */
  92     struct in6_addr nd_target;  /* IPv6 neighbor discovery (ND) target. */
  93     uint32_t skb_priority;      /* Packet priority for QoS. */
  94     uint32_t regs[FLOW_N_REGS]; /* Registers. */
  95     ovs_be32 nw_src;            /* IPv4 source address. */
  96     ovs_be32 nw_dst;            /* IPv4 destination address. */
  97     ovs_be32 ipv6_label;        /* IPv6 flow label. */
  98     union flow_in_port in_port; /* Input port.*/
  99     uint32_t pkt_mark;          /* Packet mark. */
 100     ovs_be32 mpls_lse;          /* MPLS label stack entry. */
 101     uint16_t mpls_depth;        /* Depth of MPLS stack. */
 102     ovs_be16 vlan_tci;          /* If 802.1Q, TCI | VLAN_CFI; otherwise 0. */
 103     ovs_be16 dl_type;           /* Ethernet frame type. */
 104     ovs_be16 tp_src;            /* TCP/UDP/SCTP source port. */
 105     ovs_be16 tp_dst;            /* TCP/UDP/SCTP destination port. */
 106     uint8_t dl_src[6];          /* Ethernet source address. */
 107     uint8_t dl_dst[6];          /* Ethernet destination address. */
 108     uint8_t nw_proto;           /* IP protocol or low 8 bits of ARP opcode. */
 109     uint8_t nw_tos;             /* IP ToS (including DSCP and ECN). */
 110     uint8_t arp_sha[6];         /* ARP/ND source hardware address. */
 111     uint8_t arp_tha[6];         /* ARP/ND target hardware address. */
 112     uint8_t nw_ttl;             /* IP TTL/Hop Limit. */
 113     uint8_t nw_frag;            /* FLOW_FRAG_* flags. */
 114     uint8_t zeros[6];
 115 };
 116 BUILD_ASSERT_DECL(sizeof(struct flow) % 4 == 0);
 117
 118 #define FLOW_U32S (sizeof(struct flow) / 4)
 119
 120 /* Remember to update FLOW_WC_SEQ when changing 'struct flow'. */
 121 BUILD_ASSERT_DECL(sizeof(struct flow) == sizeof(struct flow_tnl) + 160 &&
 122                   FLOW_WC_SEQ == 20);
 123
 124 /* Represents the metadata fields of struct flow. */
 125 struct flow_metadata {
 126     ovs_be64 tun_id;                 /* Encapsulating tunnel ID. */
 127     ovs_be32 tun_src;                /* Tunnel outer IPv4 src addr */
 128     ovs_be32 tun_dst;                /* Tunnel outer IPv4 dst addr */
 129     ovs_be64 metadata;               /* OpenFlow 1.1+ metadata field. */
 130     uint32_t regs[FLOW_N_REGS];      /* Registers. */
 131     uint32_t pkt_mark;               /* Packet mark. */
 132     ofp_port_t in_port;              /* OpenFlow port or zero. */
 133 };
 134
 135 void flow_extract(struct ofpbuf *, uint32_t priority, uint32_t mark,
 136                   const struct flow_tnl *, const union flow_in_port *in_port,
 137                   struct flow *);
 138
 139 void flow_zero_wildcards(struct flow *, const struct flow_wildcards *);
 140 void flow_get_metadata(const struct flow *, struct flow_metadata *);
 141
 142 char *flow_to_string(const struct flow *);
 143 void format_flags(struct ds *ds, const char *(*bit_to_string)(uint32_t),
 144                   uint32_t flags, char del);
 145
 146 void flow_format(struct ds *, const struct flow *);
 147 void flow_print(FILE *, const struct flow *);
 148 static inline int flow_compare_3way(const struct flow *, const struct flow *);
 149 static inline bool flow_equal(const struct flow *, const struct flow *);
 150 static inline size_t flow_hash(const struct flow *, uint32_t basis);
 151
 152 void flow_set_dl_vlan(struct flow *, ovs_be16 vid);
 153 void flow_set_vlan_vid(struct flow *, ovs_be16 vid);
 154 void flow_set_vlan_pcp(struct flow *, uint8_t pcp);
 155
 156 void flow_set_mpls_label(struct flow *flow, ovs_be32 label);
 157 void flow_set_mpls_ttl(struct flow *flow, uint8_t ttl);
 158 void flow_set_mpls_tc(struct flow *flow, uint8_t tc);
 159 void flow_set_mpls_bos(struct flow *flow, uint8_t stack);
 160
 161 void flow_compose(struct ofpbuf *, const struct flow *);
 162
 163 static inline int
 164 flow_compare_3way(const struct flow *a, const struct flow *b)
 165 {
 166     return memcmp(a, b, sizeof *a);
 167 }
 168
 169 static inline bool
 170 flow_equal(const struct flow *a, const struct flow *b)
 171 {
 172     return !flow_compare_3way(a, b);
 173 }
 174
 175 static inline size_t
 176 flow_hash(const struct flow *flow, uint32_t basis)
 177 {
 178     return hash_words((const uint32_t *) flow, sizeof *flow / 4, basis);
 179 }
 180
 181 static inline uint16_t
 182 ofp_to_u16(ofp_port_t ofp_port)
 183 {
 184     return (OVS_FORCE uint16_t) ofp_port;
 185 }
 186
 187 static inline uint32_t
 188 odp_to_u32(odp_port_t odp_port)
 189 {
 190     return (OVS_FORCE uint32_t) odp_port;
 191 }
 192
 193 static inline uint32_t
 194 ofp11_to_u32(ofp11_port_t ofp11_port)
 195 {
 196     return (OVS_FORCE uint32_t) ofp11_port;
 197 }
 198
 199 static inline ofp_port_t
 200 u16_to_ofp(uint16_t port)
 201 {
 202     return OFP_PORT_C(port);
 203 }
 204
 205 static inline odp_port_t
 206 u32_to_odp(uint32_t port)
 207 {
 208     return ODP_PORT_C(port);
 209 }
 210
 211 static inline ofp11_port_t
 212 u32_to_ofp11(uint32_t port)
 213 {
 214     return OFP11_PORT_C(port);
 215 }
 216
 217 static inline uint32_t
 218 hash_ofp_port(ofp_port_t ofp_port)
 219 {
 220     return hash_int(ofp_to_u16(ofp_port), 0);
 221 }
 222
 223 static inline uint32_t
 224 hash_odp_port(odp_port_t odp_port)
 225 {
 226     return hash_int(odp_to_u32(odp_port), 0);
 227 }
 228
 229 uint32_t flow_hash_in_minimask(const struct flow *, const struct minimask *,
 230                                uint32_t basis);
 231 \f
 232 /* Wildcards for a flow.
 233  *
 234  * A 1-bit in each bit in 'masks' indicates that the corresponding bit of
 235  * the flow is significant (must match).  A 0-bit indicates that the
 236  * corresponding bit of the flow is wildcarded (need not match). */
 237 struct flow_wildcards {
 238     struct flow masks;
 239 };
 240
 241 void flow_wildcards_init_catchall(struct flow_wildcards *);
 242 void flow_wildcards_init_exact(struct flow_wildcards *);
 243
 244 bool flow_wildcards_is_catchall(const struct flow_wildcards *);
 245
 246 void flow_wildcards_set_reg_mask(struct flow_wildcards *,
 247                                  int idx, uint32_t mask);
 248
 249 void flow_wildcards_and(struct flow_wildcards *dst,
 250                         const struct flow_wildcards *src1,
 251                         const struct flow_wildcards *src2);
 252 void flow_wildcards_or(struct flow_wildcards *dst,
 253                        const struct flow_wildcards *src1,
 254                        const struct flow_wildcards *src2);
 255 bool flow_wildcards_has_extra(const struct flow_wildcards *,
 256                               const struct flow_wildcards *);
 257
 258 void flow_wildcards_fold_minimask(struct flow_wildcards *,
 259                                   const struct minimask *);
 260
 261 uint32_t flow_wildcards_hash(const struct flow_wildcards *, uint32_t basis);
 262 bool flow_wildcards_equal(const struct flow_wildcards *,
 263                           const struct flow_wildcards *);
 264 uint32_t flow_hash_symmetric_l4(const struct flow *flow, uint32_t basis);
 265
 266 void flow_mask_hash_fields(const struct flow *, struct flow_wildcards *,
 267                            enum nx_hash_fields);
 268 uint32_t flow_hash_fields(const struct flow *, enum nx_hash_fields,
 269                           uint16_t basis);
 270 const char *flow_hash_fields_to_str(enum nx_hash_fields);
 271 bool flow_hash_fields_valid(enum nx_hash_fields);
 272
 273 uint32_t flow_hash_in_wildcards(const struct flow *,
 274                                 const struct flow_wildcards *,
 275                                 uint32_t basis);
 276
 277 bool flow_equal_except(const struct flow *a, const struct flow *b,
 278                        const struct flow_wildcards *);
 279 \f
 280 /* Compressed flow. */
 281
 282 #define MINI_N_INLINE (sizeof(void *) == 4 ? 7 : 8)
 283 #define MINI_N_MAPS DIV_ROUND_UP(FLOW_U32S, 32)
 284
 285 /* A sparse representation of a "struct flow".
 286  *
 287  * A "struct flow" is fairly large and tends to be mostly zeros.  Sparse
 288  * representation has two advantages.  First, it saves memory.  Second, it
 289  * saves time when the goal is to iterate over only the nonzero parts of the
 290  * struct.
 291  *
 292  * The 'map' member holds one bit for each uint32_t in a "struct flow".  Each
 293  * 0-bit indicates that the corresponding uint32_t is zero, each 1-bit that it
 294  * is nonzero.
 295  *
 296  * 'values' points to the start of an array that has one element for each 1-bit
 297  * in 'map'.  The least-numbered 1-bit is in values[0], the next 1-bit is in
 298  * values[1], and so on.
 299  *
 300  * 'values' may point to a few different locations:
 301  *
 302  *     - If 'map' has MINI_N_INLINE or fewer 1-bits, it may point to
 303  *       'inline_values'.  One hopes that this is the common case.
 304  *
 305  *     - If 'map' has more than MINI_N_INLINE 1-bits, it may point to memory
 306  *       allocated with malloc().
 307  *
 308  *     - The caller could provide storage on the stack for situations where
 309  *       that makes sense.  So far that's only proved useful for
 310  *       minimask_combine(), but the principle works elsewhere.
 311  *
 312  * The implementation maintains and depends on the invariant that every element
 313  * in 'values' is nonzero; that is, wherever a 1-bit appears in 'map', the
 314  * corresponding element of 'values' must be nonzero.
 315  */
 316 struct miniflow {
 317     uint32_t *values;
 318     uint32_t inline_values[MINI_N_INLINE];
 319     uint32_t map[MINI_N_MAPS];
 320 };
 321
 322 void miniflow_init(struct miniflow *, const struct flow *);
 323 void miniflow_clone(struct miniflow *, const struct miniflow *);
 324 void miniflow_destroy(struct miniflow *);
 325
 326 void miniflow_expand(const struct miniflow *, struct flow *);
 327
 328 uint32_t miniflow_get(const struct miniflow *, unsigned int u32_ofs);
 329 uint16_t miniflow_get_vid(const struct miniflow *);
 330
 331 bool miniflow_equal(const struct miniflow *a, const struct miniflow *b);
 332 bool miniflow_equal_in_minimask(const struct miniflow *a,
 333                                 const struct miniflow *b,
 334                                 const struct minimask *);
 335 bool miniflow_equal_flow_in_minimask(const struct miniflow *a,
 336                                      const struct flow *b,
 337                                      const struct minimask *);
 338 uint32_t miniflow_hash(const struct miniflow *, uint32_t basis);
 339 uint32_t miniflow_hash_in_minimask(const struct miniflow *,
 340                                    const struct minimask *, uint32_t basis);
 341 \f
 342 /* Compressed flow wildcards. */
 343
 344 /* A sparse representation of a "struct flow_wildcards".
 345  *
 346  * See the large comment on struct miniflow for details. */
 347 struct minimask {
 348     struct miniflow masks;
 349 };
 350
 351 void minimask_init(struct minimask *, const struct flow_wildcards *);
 352 void minimask_clone(struct minimask *, const struct minimask *);
 353 void minimask_combine(struct minimask *dst,
 354                       const struct minimask *a, const struct minimask *b,
 355                       uint32_t storage[FLOW_U32S]);
 356 void minimask_destroy(struct minimask *);
 357
 358 void minimask_expand(const struct minimask *, struct flow_wildcards *);
 359
 360 uint32_t minimask_get(const struct minimask *, unsigned int u32_ofs);
 361 uint16_t minimask_get_vid_mask(const struct minimask *);
 362
 363 bool minimask_equal(const struct minimask *a, const struct minimask *b);
 364 uint32_t minimask_hash(const struct minimask *, uint32_t basis);
 365
 366 bool minimask_has_extra(const struct minimask *, const struct minimask *);
 367 bool minimask_is_catchall(const struct minimask *);
 368
 369 #endif /* flow.h */