lib/cfm.h

   1 /*
   2  * Copyright (c) 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 CFM_H
  18 #define CFM_H 1
  19
  20 #include <stdint.h>
  21
  22 #include "hmap.h"
  23 #include "openvswitch/types.h"
  24
  25 struct flow;
  26 struct ofpbuf;
  27 struct ds;
  28
  29 /* Ethernet destination address of CCM packets. */
  30 static const uint8_t eth_addr_ccm[6] OVS_UNUSED
  31     = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x30 };
  32
  33 #define ETH_TYPE_CFM 0x8902
  34
  35 /* A 'ccm' represents a Continuity Check Message from the 802.1ag
  36  * specification.  Continuity Check Messages are broadcast periodically so that
  37  * hosts can determine who they have connectivity to. */
  38 #define CCM_LEN 74
  39 #define CCM_MAID_LEN 48
  40 struct ccm {
  41     uint8_t  mdlevel_version; /* MD Level and Version */
  42     uint8_t  opcode;
  43     uint8_t  flags;
  44     uint8_t  tlv_offset;
  45     ovs_be32 seq;
  46     ovs_be16 mpid;
  47     uint8_t  maid[CCM_MAID_LEN];
  48     uint8_t  zero[16]; /* Defined by ITU-T Y.1731 should be zero */
  49 } __attribute__((packed));
  50 BUILD_ASSERT_DECL(CCM_LEN == sizeof(struct ccm));
  51
  52 /* A 'cfm' represent a local Maintenance Point (MP) and its Connectivity Fault
  53  * Management (CFM) state machine.  Its configuration variables should be set
  54  * by clients of the CFM library. */
  55 struct cfm {
  56     /* Configuration Variables. */
  57     uint16_t mpid;              /* The MPID of this CFM. */
  58     uint8_t maid[CCM_MAID_LEN]; /* The MAID of this CFM. */
  59     int interval;               /* The requested transmission interval. */
  60
  61     /* Statistics. */
  62     struct hmap remote_mps;     /* Expected remote MPs. */
  63     bool fault;                 /* Indicates connectivity vaults. */
  64 };
  65
  66 /* Remote MPs represent foreign network entities that are configured to have
  67  * the same MAID as this CFM instance. */
  68 struct remote_mp {
  69     uint16_t mpid;         /* The Maintenance Point ID of this 'remote_mp'. */
  70     struct hmap_node node; /* In 'cfm' 'remote_mps' or 'x_remote_mps'. */
  71
  72     bool recv;           /* CCM was received since last fault check. */
  73     bool fault;          /* Indicates a connectivity fault. */
  74 };
  75
  76 struct cfm *cfm_create(void);
  77
  78 void cfm_destroy(struct cfm *);
  79
  80 void cfm_run(struct cfm *);
  81
  82 bool cfm_should_send_ccm(struct cfm *);
  83
  84 void cfm_compose_ccm(struct cfm *, struct ccm *);
  85
  86 void cfm_wait(struct cfm *);
  87
  88 bool cfm_configure(struct cfm *);
  89
  90 void cfm_update_remote_mps(struct cfm *, const uint16_t *mpid, size_t n_mpids);
  91
  92 const struct remote_mp *cfm_get_remote_mp(const struct cfm *, uint16_t mpid);
  93
  94 bool cfm_generate_maid(const char *md_name, const char *ma_name,
  95                        uint8_t maid[CCM_MAID_LEN]);
  96
  97 bool cfm_should_process_flow(const struct flow *);
  98
  99 void cfm_process_heartbeat(struct cfm *, const struct ofpbuf *packet);
 100
 101 void cfm_dump_ds(const struct cfm *, struct ds *);
 102
 103 #endif /* cfm.h */