lib/meta-flow.h

   1 /*
   2  * Copyright (c) 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
  17 #ifndef META_FLOW_H
  18 #define META_FLOW_H 1
  19
  20 #include <sys/types.h>
  21 #include <netinet/in.h>
  22 #include <netinet/ip6.h>
  23 #include "flow.h"
  24 #include "ofp-errors.h"
  25 #include "packets.h"
  26
  27 struct cls_rule;
  28 struct ds;
  29
  30 /* The comment on each of these indicates the member in "union mf_value" used
  31  * to represent its value. */
  32 enum mf_field_id {
  33     /* Metadata. */
  34     MFF_TUN_ID,                 /* be64 */
  35     MFF_METADATA,               /* be64 */
  36     MFF_IN_PORT,                /* be16 */
  37
  38 #if FLOW_N_REGS > 0
  39     MFF_REG0,                   /* be32 */
  40 #endif
  41 #if FLOW_N_REGS > 1
  42     MFF_REG1,                   /* be32 */
  43 #endif
  44 #if FLOW_N_REGS > 2
  45     MFF_REG2,                   /* be32 */
  46 #endif
  47 #if FLOW_N_REGS > 3
  48     MFF_REG3,                   /* be32 */
  49 #endif
  50 #if FLOW_N_REGS > 4
  51     MFF_REG4,                   /* be32 */
  52 #endif
  53 #if FLOW_N_REGS > 5
  54     MFF_REG5,                   /* be32 */
  55 #endif
  56 #if FLOW_N_REGS > 6
  57     MFF_REG6,                   /* be32 */
  58 #endif
  59 #if FLOW_N_REGS > 7
  60     MFF_REG7,                   /* be32 */
  61 #endif
  62
  63     /* L2. */
  64     MFF_ETH_SRC,                /* mac */
  65     MFF_ETH_DST,                /* mac */
  66     MFF_ETH_TYPE,               /* be16 */
  67
  68     MFF_VLAN_TCI,               /* be16 */
  69     MFF_VLAN_VID,               /* be16 */
  70     MFF_VLAN_PCP,               /* u8 */
  71
  72     /* L3. */
  73     MFF_IPV4_SRC,               /* be32 */
  74     MFF_IPV4_DST,               /* be32 */
  75
  76     MFF_IPV6_SRC,               /* ipv6 */
  77     MFF_IPV6_DST,               /* ipv6 */
  78     MFF_IPV6_LABEL,             /* be32 */
  79
  80     MFF_IP_PROTO,               /* u8 (used for IPv4 or IPv6) */
  81     MFF_IP_DSCP,                /* u8 (used for IPv4 or IPv6) */
  82     MFF_IP_ECN,                 /* u8 (used for IPv4 or IPv6) */
  83     MFF_IP_TTL,                 /* u8 (used for IPv4 or IPv6) */
  84     MFF_IP_FRAG,                /* u8 (used for IPv4 or IPv6) */
  85
  86     MFF_ARP_OP,                 /* be16 */
  87     MFF_ARP_SPA,                /* be32 */
  88     MFF_ARP_TPA,                /* be32 */
  89     MFF_ARP_SHA,                /* mac */
  90     MFF_ARP_THA,                /* mac */
  91
  92     /* L4. */
  93     MFF_TCP_SRC,                /* be16 (used for IPv4 or IPv6) */
  94     MFF_TCP_DST,                /* be16 (used for IPv4 or IPv6) */
  95
  96     MFF_UDP_SRC,                /* be16 (used for IPv4 or IPv6) */
  97     MFF_UDP_DST,                /* be16 (used for IPv4 or IPv6) */
  98
  99     MFF_ICMPV4_TYPE,            /* u8 */
 100     MFF_ICMPV4_CODE,            /* u8 */
 101
 102     MFF_ICMPV6_TYPE,            /* u8 */
 103     MFF_ICMPV6_CODE,            /* u8 */
 104
 105     /* ICMPv6 Neighbor Discovery. */
 106     MFF_ND_TARGET,              /* ipv6 */
 107     MFF_ND_SLL,                 /* mac */
 108     MFF_ND_TLL,                 /* mac */
 109
 110     MFF_N_IDS
 111 };
 112
 113 /* Use this macro as CASE_MFF_REGS: in a switch statement to choose all of the
 114  * MFF_REGx cases. */
 115 #if FLOW_N_REGS == 1
 116 # define CASE_MFF_REGS                                          \
 117     case MFF_REG0
 118 #elif FLOW_N_REGS == 2
 119 # define CASE_MFF_REGS                                          \
 120     case MFF_REG0: case MFF_REG1
 121 #elif FLOW_N_REGS == 3
 122 # define CASE_MFF_REGS                                          \
 123     case MFF_REG0: case MFF_REG1: case MFF_REG2
 124 #elif FLOW_N_REGS == 4
 125 # define CASE_MFF_REGS                                          \
 126     case MFF_REG0: case MFF_REG1: case MFF_REG2: case MFF_REG3
 127 #elif FLOW_N_REGS == 5
 128 # define CASE_MFF_REGS                                          \
 129     case MFF_REG0: case MFF_REG1: case MFF_REG2: case MFF_REG3: \
 130     case MFF_REG4
 131 #elif FLOW_N_REGS == 6
 132 # define CASE_MFF_REGS                                          \
 133     case MFF_REG0: case MFF_REG1: case MFF_REG2: case MFF_REG3: \
 134     case MFF_REG4: case MFF_REG5
 135 #elif FLOW_N_REGS == 7
 136 # define CASE_MFF_REGS                                          \
 137     case MFF_REG0: case MFF_REG1: case MFF_REG2: case MFF_REG3: \
 138     case MFF_REG4: case MFF_REG5: case MFF_REG6
 139 #elif FLOW_N_REGS == 8
 140 # define CASE_MFF_REGS                                          \
 141     case MFF_REG0: case MFF_REG1: case MFF_REG2: case MFF_REG3: \
 142     case MFF_REG4: case MFF_REG5: case MFF_REG6: case MFF_REG7
 143 #else
 144 # error
 145 #endif
 146
 147 /* Prerequisites for matching a field.
 148  *
 149  * A field may only be matched if the correct lower-level protocols are also
 150  * matched.  For example, the TCP port may be matched only if the Ethernet type
 151  * matches ETH_TYPE_IP and the IP protocol matches IPPROTO_TCP. */
 152 enum mf_prereqs {
 153     MFP_NONE,
 154
 155     /* L2 requirements. */
 156     MFP_ARP,
 157     MFP_IPV4,
 158     MFP_IPV6,
 159     MFP_IP_ANY,
 160
 161     /* L2+L3 requirements. */
 162     MFP_TCP,                    /* On IPv4 or IPv6. */
 163     MFP_UDP,                    /* On IPv4 or IPv6. */
 164     MFP_ICMPV4,
 165     MFP_ICMPV6,
 166
 167     /* L2+L3+L4 requirements. */
 168     MFP_ND,
 169     MFP_ND_SOLICIT,
 170     MFP_ND_ADVERT
 171 };
 172
 173 /* Forms of partial-field masking allowed for a field.
 174  *
 175  * Every field may be masked as a whole. */
 176 enum mf_maskable {
 177     MFM_NONE,                   /* No sub-field masking. */
 178     MFM_FULLY,                  /* Every bit is individually maskable. */
 179 };
 180
 181 /* How to format or parse a field's value. */
 182 enum mf_string {
 183     /* Integer formats.
 184      *
 185      * The particular MFS_* constant sets the output format.  On input, either
 186      * decimal or hexadecimal (prefixed with 0x) is accepted. */
 187     MFS_DECIMAL,
 188     MFS_HEXADECIMAL,
 189
 190     /* Other formats. */
 191     MFS_ETHERNET,
 192     MFS_IPV4,
 193     MFS_IPV6,
 194     MFS_OFP_PORT,               /* An OpenFlow port number or name. */
 195     MFS_FRAG                    /* no, yes, first, later, not_later */
 196 };
 197
 198 struct mf_field {
 199     /* Identification. */
 200     enum mf_field_id id;        /* MFF_*. */
 201     const char *name;           /* Name of this field, e.g. "eth_type". */
 202     const char *extra_name;     /* Alternate name, e.g. "dl_type", or NULL. */
 203
 204     /* Size.
 205      *
 206      * Most fields have n_bytes * 8 == n_bits.  There are a few exceptions:
 207      *
 208      *     - "dl_vlan" is 2 bytes but only 12 bits.
 209      *     - "dl_vlan_pcp" is 1 byte but only 3 bits.
 210      *     - "is_frag" is 1 byte but only 2 bits.
 211      *     - "ipv6_label" is 4 bytes but only 20 bits.
 212      */
 213     unsigned int n_bytes;       /* Width of the field in bytes. */
 214     unsigned int n_bits;        /* Number of significant bits in field. */
 215
 216     /* Properties. */
 217     enum mf_maskable maskable;
 218     flow_wildcards_t fww_bit;   /* Either 0 or exactly one FWW_* bit. */
 219     enum mf_string string;
 220     enum mf_prereqs prereqs;
 221     bool writable;              /* May be written by actions? */
 222
 223     /* NXM and OXM properties.
 224      *
 225      * There are the following possibilities for these members for a given
 226      * mf_field:
 227      *
 228      *   - Neither NXM nor OXM defines such a field: these members will all be
 229      *     zero or NULL.
 230      *
 231      *   - NXM and OXM both define such a field: nxm_header and oxm_header will
 232      *     both be nonzero and different, similarly for nxm_name and oxm_name.
 233      *
 234      *   - Only NXM or only OXM defines such a field: nxm_header and oxm_header
 235      *     will both have the same value (either an OXM_* or NXM_* value) and
 236      *     similarly for nxm_name and oxm_name.
 237      *
 238      * Thus, 'nxm_header' is the appropriate header to use when outputting an
 239      * NXM formatted match, since it will be an NXM_* constant when possible
 240      * for compatibility with OpenFlow implementations that expect that, with
 241      * OXM_* constants used for fields that OXM adds.  Conversely, 'oxm_header'
 242      * is the header to use when outputting an OXM formatted match. */
 243     uint32_t nxm_header;        /* An NXM_* (or OXM_*) constant. */
 244     const char *nxm_name;       /* The nxm_header constant's name. */
 245     uint32_t oxm_header;        /* An OXM_* (or NXM_*) constant. */
 246     const char *oxm_name;           /* The oxm_header constant's name */
 247 };
 248
 249 /* The representation of a field's value. */
 250 union mf_value {
 251     uint8_t u8;
 252     ovs_be16 be16;
 253     ovs_be32 be32;
 254     ovs_be64 be64;
 255     uint8_t mac[ETH_ADDR_LEN];
 256     struct in6_addr ipv6;
 257 };
 258 BUILD_ASSERT_DECL(sizeof(union mf_value) == 16);
 259
 260 /* Part of a field. */
 261 struct mf_subfield {
 262     const struct mf_field *field;
 263     unsigned int ofs;           /* Bit offset. */
 264     unsigned int n_bits;        /* Number of bits. */
 265 };
 266
 267 /* Data for some part of an mf_field.
 268  *
 269  * The data is stored "right-justified".  For example, if "union mf_subvalue
 270  * value" contains NXM_OF_VLAN_TCI[0..11], then one could access the
 271  * corresponding data in value.be16[7] as the bits in the mask htons(0xfff). */
 272 union mf_subvalue {
 273     uint8_t u8[16];
 274     ovs_be16 be16[8];
 275     ovs_be32 be32[4];
 276     ovs_be64 be64[2];
 277 };
 278 BUILD_ASSERT_DECL(sizeof(union mf_value) == sizeof (union mf_subvalue));
 279
 280 /* Finding mf_fields. */
 281 const struct mf_field *mf_from_id(enum mf_field_id);
 282 const struct mf_field *mf_from_name(const char *name);
 283 const struct mf_field *mf_from_nxm_header(uint32_t nxm_header);
 284 const struct mf_field *mf_from_nxm_name(const char *nxm_name);
 285
 286 /* Inspecting wildcarded bits. */
 287 bool mf_is_all_wild(const struct mf_field *, const struct flow_wildcards *);
 288
 289 bool mf_is_mask_valid(const struct mf_field *, const union mf_value *mask);
 290 void mf_get_mask(const struct mf_field *, const struct flow_wildcards *,
 291                  union mf_value *mask);
 292
 293 /* Prerequisites. */
 294 bool mf_are_prereqs_ok(const struct mf_field *, const struct flow *);
 295 void mf_force_prereqs(const struct mf_field *, struct cls_rule *);
 296
 297 /* Field values. */
 298 bool mf_is_value_valid(const struct mf_field *, const union mf_value *value);
 299
 300 void mf_get_value(const struct mf_field *, const struct flow *,
 301                   union mf_value *value);
 302 void mf_set_value(const struct mf_field *, const union mf_value *value,
 303                   struct cls_rule *);
 304 void mf_set_flow_value(const struct mf_field *, const union mf_value *value,
 305                        struct flow *);
 306 bool mf_is_zero(const struct mf_field *, const struct flow *);
 307
 308 void mf_get(const struct mf_field *, const struct cls_rule *,
 309             union mf_value *value, union mf_value *mask);
 310 void mf_set(const struct mf_field *,
 311             const union mf_value *value, const union mf_value *mask,
 312             struct cls_rule *);
 313
 314 void mf_set_wild(const struct mf_field *, struct cls_rule *);
 315
 316 void mf_random_value(const struct mf_field *, union mf_value *value);
 317
 318 /* Subfields. */
 319 void mf_write_subfield(const struct mf_subfield *, const union mf_subvalue *,
 320                        struct cls_rule *);
 321
 322 void mf_read_subfield(const struct mf_subfield *, const struct flow *,
 323                       union mf_subvalue *);
 324 uint64_t mf_get_subfield(const struct mf_subfield *, const struct flow *);
 325
 326
 327 void mf_format_subfield(const struct mf_subfield *, struct ds *);
 328 char *mf_parse_subfield__(struct mf_subfield *sf, const char **s);
 329 const char *mf_parse_subfield(struct mf_subfield *, const char *);
 330
 331 enum ofperr mf_check_src(const struct mf_subfield *, const struct flow *);
 332 enum ofperr mf_check_dst(const struct mf_subfield *, const struct flow *);
 333
 334 /* Parsing and formatting. */
 335 char *mf_parse(const struct mf_field *, const char *,
 336                union mf_value *value, union mf_value *mask);
 337 char *mf_parse_value(const struct mf_field *, const char *, union mf_value *);
 338 void mf_format(const struct mf_field *,
 339                const union mf_value *value, const union mf_value *mask,
 340                struct ds *);
 341
 342 #endif /* meta-flow.h */