lib/flow.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010 Nicira Networks.
   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 "openvswitch/datapath-protocol.h"
  28 #include "util.h"
  29
  30 struct ds;
  31 struct ofp_match;
  32 struct ofpbuf;
  33
  34 struct flow {
  35     uint32_t tun_id;            /* Encapsulating tunnel ID. */
  36     uint32_t nw_src;            /* IP source address. */
  37     uint32_t nw_dst;            /* IP destination address. */
  38     uint16_t in_port;           /* Input switch port. */
  39     uint16_t dl_vlan;           /* Input VLAN. */
  40     uint16_t dl_type;           /* Ethernet frame type. */
  41     uint16_t tp_src;            /* TCP/UDP source port. */
  42     uint16_t tp_dst;            /* TCP/UDP destination port. */
  43     uint8_t dl_src[6];          /* Ethernet source address. */
  44     uint8_t dl_dst[6];          /* Ethernet destination address. */
  45     uint8_t nw_proto;           /* IP protocol or low 8 bits of ARP opcode. */
  46     uint8_t dl_vlan_pcp;        /* Input VLAN priority. */
  47     uint8_t nw_tos;             /* IP ToS (DSCP field, 6 bits). */
  48 };
  49
  50 /* Assert that there are FLOW_SIG_SIZE bytes of significant data in "struct
  51  * flow", followed by FLOW_PAD_SIZE bytes of padding. */
  52 #define FLOW_SIG_SIZE 37
  53 #define FLOW_PAD_SIZE 3
  54 BUILD_ASSERT_DECL(offsetof(struct flow, nw_tos) == FLOW_SIG_SIZE - 1);
  55 BUILD_ASSERT_DECL(sizeof(((struct flow *)0)->nw_tos) == 1);
  56 BUILD_ASSERT_DECL(sizeof(struct flow) == FLOW_SIG_SIZE + FLOW_PAD_SIZE);
  57
  58 int flow_extract(struct ofpbuf *, uint32_t tun_id, uint16_t in_port,
  59                  struct flow *);
  60 void flow_extract_stats(const struct flow *flow, struct ofpbuf *packet,
  61         struct odp_flow_stats *stats);
  62 void flow_to_match(const struct flow *, uint32_t wildcards, bool tun_id_cookie,
  63                    struct ofp_match *);
  64 void flow_from_match(const struct ofp_match *, bool tun_id_from_cookie,
  65                      uint64_t cookie, struct flow *, uint32_t *wildcards);
  66 char *flow_to_string(const struct flow *);
  67 void flow_format(struct ds *, const struct flow *);
  68 void flow_print(FILE *, const struct flow *);
  69 static inline int flow_compare(const struct flow *, const struct flow *);
  70 static inline bool flow_equal(const struct flow *, const struct flow *);
  71 static inline size_t flow_hash(const struct flow *, uint32_t basis);
  72
  73 static inline int
  74 flow_compare(const struct flow *a, const struct flow *b)
  75 {
  76     return memcmp(a, b, FLOW_SIG_SIZE);
  77 }
  78
  79 static inline bool
  80 flow_equal(const struct flow *a, const struct flow *b)
  81 {
  82     return !flow_compare(a, b);
  83 }
  84
  85 static inline size_t
  86 flow_hash(const struct flow *flow, uint32_t basis)
  87 {
  88     return hash_bytes(flow, FLOW_SIG_SIZE, basis);
  89 }
  90
  91 /* Information on wildcards for a flow, as a supplement to struct flow. */
  92 struct flow_wildcards {
  93     uint32_t wildcards;         /* enum ofp_flow_wildcards (in host order). */
  94     uint32_t nw_src_mask;       /* 1-bit in each significant nw_src bit. */
  95     uint32_t nw_dst_mask;       /* 1-bit in each significant nw_dst bit. */
  96 };
  97
  98 /* Given the wildcard bit count in bits 'shift' through 'shift + 5' (inclusive)
  99  * of 'wildcards', returns a 32-bit bit mask with a 1 in each bit that must
 100  * match and a 0 in each bit that is wildcarded.
 101  *
 102  * The bits in 'wildcards' are in the format used in enum ofp_flow_wildcards: 0
 103  * is exact match, 1 ignores the LSB, 2 ignores the 2 least-significant bits,
 104  * ..., 32 and higher wildcard the entire field.  This is the *opposite* of the
 105  * usual convention where e.g. /24 indicates that 8 bits (not 24 bits) are
 106  * wildcarded.
 107  *
 108  * 'wildcards' is in host byte order.  The return value is in network byte
 109  * order. */
 110 static inline uint32_t
 111 flow_nw_bits_to_mask(uint32_t wildcards, int shift)
 112 {
 113     wildcards = (wildcards >> shift) & 0x3f;
 114     return wildcards < 32 ? htonl(~((1u << wildcards) - 1)) : 0;
 115 }
 116
 117 static inline void
 118 flow_wildcards_init(struct flow_wildcards *wc, uint32_t wildcards)
 119 {
 120     wc->wildcards = wildcards & OVSFW_ALL;
 121     wc->nw_src_mask = flow_nw_bits_to_mask(wc->wildcards, OFPFW_NW_SRC_SHIFT);
 122     wc->nw_dst_mask = flow_nw_bits_to_mask(wc->wildcards, OFPFW_NW_DST_SHIFT);
 123 }
 124
 125 #endif /* flow.h */