lib/ofp-util.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
  17 #ifndef OFP_UTIL_H
  18 #define OFP_UTIL_H 1
  19
  20 #include <assert.h>
  21 #include <stdbool.h>
  22 #include <stddef.h>
  23 #include <stdint.h>
  24 #include "flow.h"
  25 #include "openvswitch/types.h"
  26
  27 struct cls_rule;
  28 struct ofpbuf;
  29 struct ofp_action_header;
  30
  31 /* Alignment of ofp_actions. */
  32 #define OFP_ACTION_ALIGN 8
  33
  34 /* Converting OFPFW_NW_SRC_MASK and OFPFW_NW_DST_MASK wildcard bit counts to
  35  * and from IP bitmasks. */
  36 ovs_be32 ofputil_wcbits_to_netmask(int wcbits);
  37 int ofputil_netmask_to_wcbits(ovs_be32 netmask);
  38
  39 /* Work with OpenFlow 1.0 ofp_match. */
  40 void ofputil_cls_rule_from_match(const struct ofp_match *,
  41                                  unsigned int priority, int flow_format,
  42                                  uint64_t cookie, struct cls_rule *);
  43 void ofputil_cls_rule_to_match(const struct cls_rule *, int flow_format,
  44                                struct ofp_match *);
  45 void normalize_match(struct ofp_match *);
  46 char *ofp_match_to_literal_string(const struct ofp_match *match);
  47
  48 /* OpenFlow protocol utility functions. */
  49 void *make_openflow(size_t openflow_len, uint8_t type, struct ofpbuf **);
  50 void *make_nxmsg(size_t openflow_len, uint32_t subtype, struct ofpbuf **);
  51 void *make_openflow_xid(size_t openflow_len, uint8_t type,
  52                         ovs_be32 xid, struct ofpbuf **);
  53 void *make_nxmsg_xid(size_t openflow_len, uint32_t subtype, ovs_be32 xid,
  54                      struct ofpbuf **);
  55 void *put_openflow(size_t openflow_len, uint8_t type, struct ofpbuf *);
  56 void *put_openflow_xid(size_t openflow_len, uint8_t type, ovs_be32 xid,
  57                        struct ofpbuf *);
  58 void update_openflow_length(struct ofpbuf *);
  59 struct ofpbuf *make_flow_mod(uint16_t command, const struct flow *,
  60                              size_t actions_len);
  61 struct ofpbuf *make_add_flow(const struct flow *, uint32_t buffer_id,
  62                              uint16_t max_idle, size_t actions_len);
  63 struct ofpbuf *make_del_flow(const struct flow *);
  64 struct ofpbuf *make_add_simple_flow(const struct flow *,
  65                                     uint32_t buffer_id, uint16_t out_port,
  66                                     uint16_t max_idle);
  67 struct ofpbuf *make_packet_in(uint32_t buffer_id, uint16_t in_port,
  68                               uint8_t reason,
  69                               const struct ofpbuf *payload, int max_send_len);
  70 struct ofpbuf *make_packet_out(const struct ofpbuf *packet, uint32_t buffer_id,
  71                                uint16_t in_port,
  72                                const struct ofp_action_header *,
  73                                size_t n_actions);
  74 struct ofpbuf *make_buffered_packet_out(uint32_t buffer_id,
  75                                         uint16_t in_port, uint16_t out_port);
  76 struct ofpbuf *make_unbuffered_packet_out(const struct ofpbuf *packet,
  77                                           uint16_t in_port, uint16_t out_port);
  78 struct ofpbuf *make_echo_request(void);
  79 struct ofpbuf *make_echo_reply(const struct ofp_header *rq);
  80 int check_ofp_message(const struct ofp_header *, uint8_t type, size_t size);
  81 int check_ofp_message_array(const struct ofp_header *, uint8_t type,
  82                             size_t size, size_t array_elt_size,
  83                             size_t *n_array_elts);
  84
  85 struct flow_stats_iterator {
  86     const uint8_t *pos, *end;
  87 };
  88 const struct ofp_flow_stats *flow_stats_first(struct flow_stats_iterator *,
  89                                               const struct ofp_stats_reply *);
  90 const struct ofp_flow_stats *flow_stats_next(struct flow_stats_iterator *);
  91
  92 struct actions_iterator {
  93     const union ofp_action *pos, *end;
  94 };
  95 const union ofp_action *actions_first(struct actions_iterator *,
  96                                       const union ofp_action *,
  97                                       size_t n_actions);
  98 const union ofp_action *actions_next(struct actions_iterator *);
  99 int validate_actions(const union ofp_action *, size_t n_actions,
 100                      const struct flow *, int max_ports);
 101 bool action_outputs_to_port(const union ofp_action *, uint16_t port);
 102
 103 int ofputil_pull_actions(struct ofpbuf *, unsigned int actions_len,
 104                          union ofp_action **, size_t *);
 105 \f
 106 /* OpenFlow vendors.
 107  *
 108  * These functions map OpenFlow 32-bit vendor IDs (as used in struct
 109  * ofp_vendor_header) into 4-bit values to embed in an "int".  The 4-bit values
 110  * are only used internally in Open vSwitch and never appear on the wire, so
 111  * particular codes used are not important.
 112  */
 113
 114 /* Vendor error numbers currently used in Open vSwitch. */
 115 #define OFPUTIL_VENDORS                                     \
 116     /*             vendor name              vendor value */ \
 117     OFPUTIL_VENDOR(OFPUTIL_VENDOR_OPENFLOW, 0x00000000)     \
 118     OFPUTIL_VENDOR(OFPUTIL_VENDOR_NICIRA,   NX_VENDOR_ID)
 119
 120 /* OFPUTIL_VENDOR_* definitions. */
 121 enum ofputil_vendor_codes {
 122 #define OFPUTIL_VENDOR(NAME, VENDOR_ID) NAME,
 123     OFPUTIL_VENDORS
 124     OFPUTIL_N_VENDORS
 125 #undef OFPUTIL_VENDOR
 126 };
 127 \f
 128 /* Error codes.
 129  *
 130  * We embed system errno values and OpenFlow standard and vendor extension
 131  * error codes into a single 31-bit space using the following encoding.
 132  * (Bit 31 is unused and assumed 0 to avoid negative "int" values.)
 133  *
 134  *   30                                                   0
 135  *  +------------------------------------------------------+
 136  *  |                           0                          |  success
 137  *  +------------------------------------------------------+
 138  *
 139  *   30 29                                                0
 140  *  +--+---------------------------------------------------+
 141  *  | 0|                    errno value                    |  errno value
 142  *  +--+---------------------------------------------------+
 143  *
 144  *   30 29   26 25            16 15                       0
 145  *  +--+-------+----------------+--------------------------+
 146  *  | 1|   0   |      type      |           code           |  standard OpenFlow
 147  *  +--+-------+----------------+--------------------------+  error
 148  *
 149  *   30 29   26 25            16 15                       0
 150  *  +--+-------+----------------+--------------------------+  Nicira
 151  *  | 1| vendor|      type      |           code           |  NXET_VENDOR
 152  *  +--+-------+----------------+--------------------------+  error extension
 153  *
 154  * C and POSIX say that errno values are positive.  We assume that they are
 155  * less than 2**29.  They are actually less than 65536 on at least Linux,
 156  * FreeBSD, OpenBSD, and Windows.
 157  *
 158  * The 'vendor' field holds one of the OFPUTIL_VENDOR_* codes defined above.
 159  * It must be nonzero.
 160  *
 161  * Negative values are not defined.
 162  */
 163
 164 /* Currently 4 bits are allocated to the "vendor" field.  Make sure that all
 165  * the vendor codes can fit. */
 166 BUILD_ASSERT_DECL(OFPUTIL_N_VENDORS <= 16);
 167
 168 /* These are macro versions of the functions defined below.  The macro versions
 169  * are intended for use in contexts where function calls are not allowed,
 170  * e.g. static initializers and case labels. */
 171 #define OFP_MKERR(TYPE, CODE) ((1 << 30) | ((TYPE) << 16) | (CODE))
 172 #define OFP_MKERR_VENDOR(VENDOR, TYPE, CODE) \
 173         ((1 << 30) | ((VENDOR) << 26) | ((TYPE) << 16) | (CODE))
 174 #define OFP_MKERR_NICIRA(TYPE, CODE) \
 175         OFP_MKERR_VENDOR(OFPUTIL_VENDOR_NICIRA, TYPE, CODE)
 176
 177 /* Returns the standard OpenFlow error with the specified 'type' and 'code' as
 178  * an integer. */
 179 static inline int
 180 ofp_mkerr(uint16_t type, uint16_t code)
 181 {
 182     return OFP_MKERR(type, code);
 183 }
 184
 185 /* Returns the OpenFlow vendor error with the specified 'vendor', 'type', and
 186  * 'code' as an integer.  'vendor' must be an OFPUTIL_VENDOR_* constant. */
 187 static inline int
 188 ofp_mkerr_vendor(uint8_t vendor, uint16_t type, uint16_t code)
 189 {
 190     assert(vendor < OFPUTIL_N_VENDORS);
 191     return OFP_MKERR_VENDOR(vendor, type, code);
 192 }
 193
 194 /* Returns the OpenFlow vendor error with Nicira as vendor, with the specific
 195  * 'type' and 'code', as an integer. */
 196 static inline int
 197 ofp_mkerr_nicira(uint16_t type, uint16_t code)
 198 {
 199     return OFP_MKERR_NICIRA(type, code);
 200 }
 201
 202 /* Returns true if 'error' encodes an OpenFlow standard or vendor extension
 203  * error codes as documented above. */
 204 static inline bool
 205 is_ofp_error(int error)
 206 {
 207     return (error & (1 << 30)) != 0;
 208 }
 209
 210 /* Returns true if 'error' appears to be a system errno value. */
 211 static inline bool
 212 is_errno(int error)
 213 {
 214     return !is_ofp_error(error);
 215 }
 216
 217 /* Returns the "vendor" part of the OpenFlow error code 'error' (which must be
 218  * in the format explained above).  This is normally one of the
 219  * OFPUTIL_VENDOR_* constants.  Returns OFPUTIL_VENDOR_OPENFLOW (0) for a
 220  * standard OpenFlow error. */
 221 static inline uint8_t
 222 get_ofp_err_vendor(int error)
 223 {
 224     return (error >> 26) & 0xf;
 225 }
 226
 227 /* Returns the "type" part of the OpenFlow error code 'error' (which must be in
 228  * the format explained above). */
 229 static inline uint16_t
 230 get_ofp_err_type(int error)
 231 {
 232     return (error >> 16) & 0x3ff;
 233 }
 234
 235 /* Returns the "code" part of the OpenFlow error code 'error' (which must be in
 236  * the format explained above). */
 237 static inline uint16_t
 238 get_ofp_err_code(int error)
 239 {
 240     return error & 0xffff;
 241 }
 242
 243 struct ofpbuf *make_ofp_error_msg(int error, const struct ofp_header *);
 244
 245 #endif /* ofp-util.h */