lib/odp-util.h

   1 /*
   2  * Copyright (c) 2009, 2010, 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 ODP_UTIL_H
  18 #define ODP_UTIL_H 1
  19
  20 #include <stdbool.h>
  21 #include <stddef.h>
  22 #include <stdint.h>
  23 #include <string.h>
  24 #include <linux/openvswitch.h>
  25 #include "hash.h"
  26 #include "openflow/openflow.h"
  27 #include "util.h"
  28
  29 struct ds;
  30 struct flow;
  31 struct nlattr;
  32 struct ofpbuf;
  33 struct simap;
  34
  35 #define OVSP_NONE ((uint16_t) -1)
  36
  37 static inline uint16_t
  38 ofp_port_to_odp_port(uint16_t ofp_port)
  39 {
  40     switch (ofp_port) {
  41     case OFPP_LOCAL:
  42         return OVSP_LOCAL;
  43     case OFPP_NONE:
  44         return OVSP_NONE;
  45     default:
  46         return ofp_port;
  47     }
  48 }
  49
  50 static inline uint16_t
  51 odp_port_to_ofp_port(uint16_t odp_port)
  52 {
  53     switch (odp_port) {
  54     case OVSP_LOCAL:
  55         return OFPP_LOCAL;
  56     case OVSP_NONE:
  57         return OFPP_NONE;
  58     default:
  59         return odp_port;
  60     }
  61 }
  62
  63 void format_odp_actions(struct ds *, const struct nlattr *odp_actions,
  64                         size_t actions_len);
  65 int odp_actions_from_string(const char *, const struct simap *port_names,
  66                             struct ofpbuf *odp_actions);
  67
  68 /* The maximum number of bytes that odp_flow_key_from_flow() appends to a
  69  * buffer.  This is the upper bound on the length of a nlattr-formatted flow
  70  * key that ovs-vswitchd fully understands.
  71  *
  72  * OVS doesn't insist that ovs-vswitchd and the datapath have exactly the same
  73  * idea of a flow, so therefore this value isn't necessarily an upper bound on
  74  * the length of a flow key that the datapath can pass to ovs-vswitchd.
  75  *
  76  * The longest nlattr-formatted flow key appended by odp_flow_key_from_flow()
  77  * would be:
  78  *
  79  *                         struct  pad  nl hdr  total
  80  *                         ------  ---  ------  -----
  81  *  OVS_KEY_ATTR_PRIORITY      4    --     4      8
  82  *  OVS_KEY_ATTR_TUN_ID        8    --     4     12
  83  *  OVS_KEY_ATTR_IN_PORT       4    --     4      8
  84  *  OVS_KEY_ATTR_ETHERNET     12    --     4     16
  85  *  OVS_KEY_ATTR_ETHERTYPE     2     2     4      8  (outer VLAN ethertype)
  86  *  OVS_KEY_ATTR_8021Q         4    --     4      8
  87  *  OVS_KEY_ATTR_ENCAP         0    --     4      4  (VLAN encapsulation)
  88  *  OVS_KEY_ATTR_ETHERTYPE     2     2     4      8  (inner VLAN ethertype)
  89  *  OVS_KEY_ATTR_IPV6         40    --     4     44
  90  *  OVS_KEY_ATTR_ICMPV6        2     2     4      8
  91  *  OVS_KEY_ATTR_ND           28    --     4     32
  92  *  -------------------------------------------------
  93  *  total                                       156
  94  *
  95  * We include some slack space in case the calculation isn't quite right or we
  96  * add another field and forget to adjust this value.
  97  */
  98 #define ODPUTIL_FLOW_KEY_BYTES 200
  99
 100 /* A buffer with sufficient size and alignment to hold an nlattr-formatted flow
 101  * key.  An array of "struct nlattr" might not, in theory, be sufficiently
 102  * aligned because it only contains 16-bit types. */
 103 struct odputil_keybuf {
 104     uint32_t keybuf[DIV_ROUND_UP(ODPUTIL_FLOW_KEY_BYTES, 4)];
 105 };
 106
 107 void odp_flow_key_format(const struct nlattr *, size_t, struct ds *);
 108 int odp_flow_key_from_string(const char *s, const struct simap *port_names,
 109                              struct ofpbuf *);
 110
 111 void odp_flow_key_from_flow(struct ofpbuf *, const struct flow *);
 112
 113 uint32_t odp_flow_key_hash(const struct nlattr *, size_t);
 114
 115 /* How well a kernel-provided flow key (a sequence of OVS_KEY_ATTR_*
 116  * attributes) matches OVS userspace expectations.
 117  *
 118  * These values are arranged so that greater values are "more important" than
 119  * lesser ones.  In particular, a single flow key can fit the descriptions for
 120  * both ODP_FIT_TOO_LITTLE and ODP_FIT_TOO_MUCH.  Such a key is treated as
 121  * ODP_FIT_TOO_LITTLE. */
 122 enum odp_key_fitness {
 123     ODP_FIT_PERFECT,            /* The key had exactly the fields we expect. */
 124     ODP_FIT_TOO_MUCH,           /* The key had fields we don't understand. */
 125     ODP_FIT_TOO_LITTLE,         /* The key lacked fields we expected to see. */
 126     ODP_FIT_ERROR,              /* The key was invalid. */
 127 };
 128 enum odp_key_fitness odp_flow_key_to_flow(const struct nlattr *, size_t,
 129                                           struct flow *);
 130 const char *odp_key_fitness_to_string(enum odp_key_fitness);
 131
 132 void commit_odp_actions(const struct flow *, struct flow *base,
 133                         struct ofpbuf *odp_actions);
 134 \f
 135 /* ofproto-dpif interface.
 136  *
 137  * The following types and functions are logically part of ofproto-dpif.
 138  * ofproto-dpif puts values of these types into the flows that it installs in
 139  * the kernel datapath, though, so ovs-dpctl needs to interpret them so that
 140  * it can print flows in a more human-readable manner. */
 141
 142 enum user_action_cookie_type {
 143     USER_ACTION_COOKIE_UNSPEC,
 144     USER_ACTION_COOKIE_SFLOW,        /* Packet for sFlow sampling. */
 145     USER_ACTION_COOKIE_SLOW_PATH     /* Userspace must process this flow. */
 146 };
 147
 148 /* user_action_cookie is passed as argument to OVS_ACTION_ATTR_USERSPACE.
 149  * Since it is passed to kernel as u64, its size has to be 8 bytes. */
 150 union user_action_cookie {
 151     uint16_t type;              /* enum user_action_cookie_type. */
 152
 153     struct {
 154         uint16_t type;          /* USER_ACTION_COOKIE_SFLOW. */
 155         ovs_be16 vlan_tci;      /* Destination VLAN TCI. */
 156         uint32_t output;        /* SFL_FLOW_SAMPLE_TYPE 'output' value. */
 157     } sflow;
 158
 159     struct {
 160         uint16_t type;          /* USER_ACTION_COOKIE_SLOW_PATH. */
 161         uint16_t unused;
 162         uint32_t reason;        /* enum slow_path_reason. */
 163     } slow_path;
 164 };
 165 BUILD_ASSERT_DECL(sizeof(union user_action_cookie) == 8);
 166
 167 size_t odp_put_userspace_action(uint32_t pid,
 168                                 const union user_action_cookie *,
 169                                 struct ofpbuf *odp_actions);
 170
 171 /* Reasons why a subfacet might not be fast-pathable. */
 172 enum slow_path_reason {
 173     /* These reasons are mutually exclusive. */
 174     SLOW_CFM = 1 << 0,          /* CFM packets need per-packet processing. */
 175     SLOW_LACP = 1 << 1,         /* LACP packets need per-packet processing. */
 176     SLOW_STP = 1 << 2,          /* STP packets need per-packet processing. */
 177     SLOW_IN_BAND = 1 << 3,      /* In-band control needs every packet. */
 178
 179     /* Mutually exclusive with SLOW_CFM, SLOW_LACP, SLOW_STP.
 180      * Could possibly appear with SLOW_IN_BAND. */
 181     SLOW_CONTROLLER = 1 << 4,   /* Packets must go to OpenFlow controller. */
 182
 183     /* This can appear on its own, or, theoretically at least, along with any
 184      * other combination of reasons. */
 185     SLOW_MATCH = 1 << 5,        /* Datapath can't match specifically enough. */
 186 };
 187
 188 #endif /* odp-util.h */