nest/protocol.h

   1 /*
   2  *      BIRD Internet Routing Daemon -- Protocols
   3  *
   4  *      (c) 1998--2000 Martin Mares <mj@ucw.cz>
   5  *
   6  *      Can be freely distributed and used under the terms of the GNU GPL.
   7  */
   8
   9 #ifndef _BIRD_PROTOCOL_H_
  10 #define _BIRD_PROTOCOL_H_
  11
  12 #include "lib/lists.h"
  13 #include "lib/resource.h"
  14 #include "lib/event.h"
  15 #include "nest/route.h"
  16 #include "conf/conf.h"
  17
  18 struct iface;
  19 struct ifa;
  20 struct rtable;
  21 struct rte;
  22 struct neighbor;
  23 struct rta;
  24 struct network;
  25 struct proto_config;
  26 struct channel_limit;
  27 struct channel_config;
  28 struct config;
  29 struct proto;
  30 struct channel;
  31 struct ea_list;
  32 struct eattr;
  33 struct symbol;
  34
  35
  36 /*
  37  *      Routing Protocol
  38  */
  39
  40 enum protocol_class {
  41   PROTOCOL_NONE,
  42   PROTOCOL_BABEL,
  43   PROTOCOL_BFD,
  44   PROTOCOL_BGP,
  45   PROTOCOL_DEVICE,
  46   PROTOCOL_DIRECT,
  47   PROTOCOL_KERNEL,
  48   PROTOCOL_OSPF,
  49   PROTOCOL_PIPE,
  50   PROTOCOL_RADV,
  51   PROTOCOL_RIP,
  52   PROTOCOL_RPKI,
  53   PROTOCOL_STATIC,
  54   PROTOCOL__MAX
  55 };
  56
  57 extern struct protocol *class_to_protocol[PROTOCOL__MAX];
  58
  59 struct protocol {
  60   node n;
  61   char *name;
  62   char *template;                       /* Template for automatic generation of names */
  63   int name_counter;                     /* Counter for automatic name generation */
  64   enum protocol_class class;            /* Machine readable protocol class */
  65   uint preference;                      /* Default protocol preference */
  66   uint channel_mask;                    /* Mask of accepted channel types (NB_*) */
  67   uint proto_size;                      /* Size of protocol data structure */
  68   uint config_size;                     /* Size of protocol config data structure */
  69
  70   void (*preconfig)(struct protocol *, struct config *);        /* Just before configuring */
  71   void (*postconfig)(struct proto_config *);                    /* After configuring each instance */
  72   struct proto * (*init)(struct proto_config *);                /* Create new instance */
  73   int (*reconfigure)(struct proto *, struct proto_config *);    /* Try to reconfigure instance, returns success */
  74   void (*dump)(struct proto *);                 /* Debugging dump */
  75   void (*dump_attrs)(struct rte *);             /* Dump protocol-dependent attributes */
  76   int (*start)(struct proto *);                 /* Start the instance */
  77   int (*shutdown)(struct proto *);              /* Stop the instance */
  78   void (*cleanup)(struct proto *);              /* Called after shutdown when protocol became hungry/down */
  79   void (*get_status)(struct proto *, byte *buf); /* Get instance status (for `show protocols' command) */
  80   void (*get_route_info)(struct rte *, byte *buf); /* Get route information (for `show route' command) */
  81   int (*get_attr)(struct eattr *, byte *buf, int buflen);       /* ASCIIfy dynamic attribute (returns GA_*) */
  82   void (*show_proto_info)(struct proto *);      /* Show protocol info (for `show protocols all' command) */
  83   void (*copy_config)(struct proto_config *, struct proto_config *);    /* Copy config from given protocol instance */
  84 };
  85
  86 void protos_build(void);
  87 void proto_build(struct protocol *);
  88 void protos_preconfig(struct config *);
  89 void protos_commit(struct config *new, struct config *old, int force_restart, int type);
  90 void protos_dump_all(void);
  91
  92 #define GA_UNKNOWN      0               /* Attribute not recognized */
  93 #define GA_NAME         1               /* Result = name */
  94 #define GA_FULL         2               /* Result = both name and value */
  95
  96 /*
  97  *      Known protocols
  98  */
  99
 100 extern struct protocol
 101   proto_device, proto_radv, proto_rip, proto_static,
 102   proto_ospf, proto_pipe, proto_bgp, proto_bfd, proto_babel, proto_rpki;
 103
 104 /*
 105  *      Routing Protocol Instance
 106  */
 107
 108 struct proto_config {
 109   node n;
 110   struct config *global;                /* Global configuration data */
 111   struct protocol *protocol;            /* Protocol */
 112   struct proto *proto;                  /* Instance we've created */
 113   char *name;
 114   char *dsc;
 115   int class;                            /* SYM_PROTO or SYM_TEMPLATE */
 116   u8 net_type;                          /* Protocol network type (NET_*), 0 for undefined */
 117   u8 disabled;                          /* Protocol enabled/disabled by default */
 118   u32 debug, mrtdump;                   /* Debugging bitfields, both use D_* constants */
 119   u32 router_id;                        /* Protocol specific router ID */
 120
 121   list channels;                        /* List of channel configs (struct channel_config) */
 122   struct iface *vrf;                    /* Related VRF instance, NULL if global */
 123
 124   /* Check proto_reconfigure() and proto_copy_config() after changing struct proto_config */
 125
 126   /* Protocol-specific data follow... */
 127 };
 128
 129 /* Protocol statistics */
 130 struct proto_stats {
 131   /* Import - from protocol to core */
 132   u32 imp_routes;               /* Number of routes successfully imported to the (adjacent) routing table */
 133   u32 filt_routes;              /* Number of routes rejected in import filter but kept in the routing table */
 134   u32 imp_updates_received;     /* Number of route updates received */
 135   u32 imp_updates_invalid;      /* Number of route updates rejected as invalid */
 136   u32 imp_updates_filtered;     /* Number of route updates rejected by filters */
 137   u32 imp_updates_ignored;      /* Number of route updates rejected as already in route table */
 138   u32 imp_updates_accepted;     /* Number of route updates accepted and imported */
 139   u32 imp_withdraws_received;   /* Number of route withdraws received */
 140   u32 imp_withdraws_invalid;    /* Number of route withdraws rejected as invalid */
 141   u32 imp_withdraws_ignored;    /* Number of route withdraws rejected as already not in route table */
 142   u32 imp_withdraws_accepted;   /* Number of route withdraws accepted and processed */
 143
 144   /* Export - from core to protocol */
 145   u32 exp_routes;               /* Number of routes successfully exported to the protocol */
 146   u32 exp_updates_received;     /* Number of route updates received */
 147   u32 exp_updates_rejected;     /* Number of route updates rejected by protocol */
 148   u32 exp_updates_filtered;     /* Number of route updates rejected by filters */
 149   u32 exp_updates_accepted;     /* Number of route updates accepted and exported */
 150   u32 exp_withdraws_received;   /* Number of route withdraws received */
 151   u32 exp_withdraws_accepted;   /* Number of route withdraws accepted and processed */
 152 };
 153
 154 struct proto {
 155   node n;                               /* Node in global proto_list */
 156   struct protocol *proto;               /* Protocol */
 157   struct proto_config *cf;              /* Configuration data */
 158   struct proto_config *cf_new;          /* Configuration we want to switch to after shutdown (NULL=delete) */
 159   pool *pool;                           /* Pool containing local objects */
 160   event *event;                         /* Protocol event */
 161
 162   list channels;                        /* List of channels to rtables (struct channel) */
 163   struct channel *main_channel;         /* Primary channel */
 164   struct rte_src *main_source;          /* Primary route source */
 165   struct iface *vrf;                    /* Related VRF instance, NULL if global */
 166
 167   char *name;                           /* Name of this instance (== cf->name) */
 168   u32 debug;                            /* Debugging flags */
 169   u32 mrtdump;                          /* MRTDump flags */
 170   uint active_channels;                 /* Number of active channels */
 171   byte net_type;                        /* Protocol network type (NET_*), 0 for undefined */
 172   byte disabled;                        /* Manually disabled */
 173   byte proto_state;                     /* Protocol state machine (PS_*, see below) */
 174   byte active;                          /* From PS_START to cleanup after PS_STOP */
 175   byte do_start;                        /* Start actions are scheduled */
 176   byte do_stop;                         /* Stop actions are scheduled */
 177   byte reconfiguring;                   /* We're shutting down due to reconfiguration */
 178   byte gr_recovery;                     /* Protocol should participate in graceful restart recovery */
 179   byte down_sched;                      /* Shutdown is scheduled for later (PDS_*) */
 180   byte down_code;                       /* Reason for shutdown (PDC_* codes) */
 181   u32 hash_key;                         /* Random key used for hashing of neighbors */
 182   btime last_state_change;              /* Time of last state transition */
 183   char *last_state_name_announced;      /* Last state name we've announced to the user */
 184   char *message;                        /* State-change message, allocated from proto_pool */
 185
 186   /*
 187    *    General protocol hooks:
 188    *
 189    *       if_notify    Notify protocol about interface state changes.
 190    *       ifa_notify   Notify protocol about interface address changes.
 191    *       rt_notify    Notify protocol about routing table updates.
 192    *       neigh_notify Notify protocol about neighbor cache events.
 193    *       make_tmp_attrs  Construct ea_list from private attrs stored in rte.
 194    *       store_tmp_attrs Store private attrs back to rta. The route MUST NOT be cached.
 195    *       import_control  Called as the first step of the route importing process.
 196    *                    It can construct a new rte, add private attributes and
 197    *                    decide whether the route shall be imported: 1=yes, -1=no,
 198    *                    0=process it through the import filter set by the user.
 199    *       reload_routes   Request channel to reload all its routes to the core
 200    *                    (using rte_update()). Returns: 0=reload cannot be done,
 201    *                    1= reload is scheduled and will happen (asynchronously).
 202    *       feed_begin   Notify channel about beginning of route feeding.
 203    *       feed_end     Notify channel about finish of route feeding.
 204    */
 205
 206   void (*if_notify)(struct proto *, unsigned flags, struct iface *i);
 207   void (*ifa_notify)(struct proto *, unsigned flags, struct ifa *a);
 208   void (*rt_notify)(struct proto *, struct channel *, struct network *net, struct rte *new, struct rte *old);
 209   void (*neigh_notify)(struct neighbor *neigh);
 210   struct ea_list *(*make_tmp_attrs)(struct rte *rt, struct linpool *pool);
 211   void (*store_tmp_attrs)(struct rte *rt);
 212   int (*import_control)(struct proto *, struct rte **rt, struct linpool *pool);
 213   void (*reload_routes)(struct channel *);
 214   void (*feed_begin)(struct channel *, int initial);
 215   void (*feed_end)(struct channel *);
 216
 217   /*
 218    *    Routing entry hooks (called only for routes belonging to this protocol):
 219    *
 220    *       rte_recalculate Called at the beginning of the best route selection
 221    *       rte_better   Compare two rte's and decide which one is better (1=first, 0=second).
 222    *       rte_same     Compare two rte's and decide whether they are identical (1=yes, 0=no).
 223    *       rte_mergable Compare two rte's and decide whether they could be merged (1=yes, 0=no).
 224    *       rte_insert   Called whenever a rte is inserted to a routing table.
 225    *       rte_remove   Called whenever a rte is removed from the routing table.
 226    */
 227
 228   int (*rte_recalculate)(struct rtable *, struct network *, struct rte *, struct rte *, struct rte *);
 229   int (*rte_better)(struct rte *, struct rte *);
 230   int (*rte_same)(struct rte *, struct rte *);
 231   int (*rte_mergable)(struct rte *, struct rte *);
 232   void (*rte_insert)(struct network *, struct rte *);
 233   void (*rte_remove)(struct network *, struct rte *);
 234
 235   /* Hic sunt protocol-specific data */
 236 };
 237
 238 struct proto_spec {
 239   void *ptr;
 240   int patt;
 241 };
 242
 243
 244 #define PDS_DISABLE             1       /* Proto disable scheduled */
 245 #define PDS_RESTART             2       /* Proto restart scheduled */
 246
 247 #define PDC_CF_REMOVE           0x01    /* Removed in new config */
 248 #define PDC_CF_DISABLE          0x02    /* Disabled in new config */
 249 #define PDC_CF_RESTART          0x03    /* Restart due to reconfiguration */
 250 #define PDC_CMD_DISABLE         0x11    /* Result of disable command */
 251 #define PDC_CMD_RESTART         0x12    /* Result of restart command */
 252 #define PDC_CMD_SHUTDOWN        0x13    /* Result of global shutdown */
 253 #define PDC_RX_LIMIT_HIT        0x21    /* Route receive limit reached */
 254 #define PDC_IN_LIMIT_HIT        0x22    /* Route import limit reached */
 255 #define PDC_OUT_LIMIT_HIT       0x23    /* Route export limit reached */
 256
 257
 258 void *proto_new(struct proto_config *);
 259 void *proto_config_new(struct protocol *, int class);
 260 void proto_copy_config(struct proto_config *dest, struct proto_config *src);
 261 void proto_set_message(struct proto *p, char *msg, int len);
 262
 263 void graceful_restart_recovery(void);
 264 void graceful_restart_init(void);
 265 void graceful_restart_show_status(void);
 266 void channel_graceful_restart_lock(struct channel *c);
 267 void channel_graceful_restart_unlock(struct channel *c);
 268
 269 #define DEFAULT_GR_WAIT 240
 270
 271 void channel_show_limit(struct channel_limit *l, const char *dsc);
 272 void channel_show_info(struct channel *c);
 273
 274 void proto_cmd_show(struct proto *, uintptr_t, int);
 275 void proto_cmd_disable(struct proto *, uintptr_t, int);
 276 void proto_cmd_enable(struct proto *, uintptr_t, int);
 277 void proto_cmd_restart(struct proto *, uintptr_t, int);
 278 void proto_cmd_reload(struct proto *, uintptr_t, int);
 279 void proto_cmd_debug(struct proto *, uintptr_t, int);
 280 void proto_cmd_mrtdump(struct proto *, uintptr_t, int);
 281
 282 void proto_apply_cmd(struct proto_spec ps, void (* cmd)(struct proto *, uintptr_t, int), int restricted, uintptr_t arg);
 283 struct proto *proto_get_named(struct symbol *, struct protocol *);
 284
 285 #define CMD_RELOAD      0
 286 #define CMD_RELOAD_IN   1
 287 #define CMD_RELOAD_OUT  2
 288
 289 static inline u32
 290 proto_get_router_id(struct proto_config *pc)
 291 {
 292   return pc->router_id ? pc->router_id : pc->global->router_id;
 293 }
 294
 295 static inline void
 296 rte_make_tmp_attrs(struct rte **rt, struct linpool *pool)
 297 {
 298   struct ea_list *(*mta)(struct rte *rt, struct linpool *pool);
 299   mta = (*rt)->attrs->src->proto->make_tmp_attrs;
 300   if (!mta) return;
 301   *rt = rte_cow_rta(*rt, pool);
 302   struct ea_list *ea = mta(*rt, pool);
 303   ea->next = (*rt)->attrs->eattrs;
 304   (*rt)->attrs->eattrs = ea;
 305 }
 306
 307 /* Moved from route.h to avoid dependency conflicts */
 308 static inline void rte_update(struct proto *p, const net_addr *n, rte *new) { rte_update2(p->main_channel, n, new, p->main_source); }
 309
 310 extern pool *proto_pool;
 311 extern list proto_list;
 312
 313 /*
 314  *  Each protocol instance runs two different state machines:
 315  *
 316  *  [P] The protocol machine: (implemented inside protocol)
 317  *
 318  *              DOWN    ---->    START
 319  *                ^                |
 320  *                |                V
 321  *              STOP    <----     UP
 322  *
 323  *      States: DOWN    Protocol is down and it's waiting for the core
 324  *                      requesting protocol start.
 325  *              START   Protocol is waiting for connection with the rest
 326  *                      of the network and it's not willing to accept
 327  *                      packets. When it connects, it goes to UP state.
 328  *              UP      Protocol is up and running. When the network
 329  *                      connection breaks down or the core requests
 330  *                      protocol to be terminated, it goes to STOP state.
 331  *              STOP    Protocol is disconnecting from the network.
 332  *                      After it disconnects, it returns to DOWN state.
 333  *
 334  *      In:     start() Called in DOWN state to request protocol startup.
 335  *                      Returns new state: either UP or START (in this
 336  *                      case, the protocol will notify the core when it
 337  *                      finally comes UP).
 338  *              stop()  Called in START, UP or STOP state to request
 339  *                      protocol shutdown. Returns new state: either
 340  *                      DOWN or STOP (in this case, the protocol will
 341  *                      notify the core when it finally comes DOWN).
 342  *
 343  *      Out:    proto_notify_state() -- called by protocol instance when
 344  *                      it does any state transition not covered by
 345  *                      return values of start() and stop(). This includes
 346  *                      START->UP (delayed protocol startup), UP->STOP
 347  *                      (spontaneous shutdown) and STOP->DOWN (delayed
 348  *                      shutdown).
 349  */
 350
 351 #define PS_DOWN 0
 352 #define PS_START 1
 353 #define PS_UP 2
 354 #define PS_STOP 3
 355
 356 void proto_notify_state(struct proto *p, unsigned state);
 357
 358 /*
 359  *  [F] The feeder machine: (implemented in core routines)
 360  *
 361  *              HUNGRY    ---->   FEEDING
 362  *               ^                   |
 363  *               |                   V
 364  *              FLUSHING  <----   HAPPY
 365  *
 366  *      States: HUNGRY  Protocol either administratively down (i.e.,
 367  *                      disabled by the user) or temporarily down
 368  *                      (i.e., [P] is not UP)
 369  *              FEEDING The protocol came up and we're feeding it
 370  *                      initial routes. [P] is UP.
 371  *              HAPPY   The protocol is up and it's receiving normal
 372  *                      routing updates. [P] is UP.
 373  *              FLUSHING The protocol is down and we're removing its
 374  *                      routes from the table. [P] is STOP or DOWN.
 375  *
 376  *      Normal lifecycle of a protocol looks like:
 377  *
 378  *              HUNGRY/DOWN --> HUNGRY/START --> HUNGRY/UP -->
 379  *              FEEDING/UP --> HAPPY/UP --> FLUSHING/STOP|DOWN -->
 380  *              HUNGRY/STOP|DOWN --> HUNGRY/DOWN
 381  *
 382  *      Sometimes, protocol might switch from HAPPY/UP to FEEDING/UP
 383  *      if it wants to refeed the routes (for example BGP does so
 384  *      as a result of received ROUTE-REFRESH request).
 385  */
 386
 387
 388
 389 /*
 390  *      Debugging flags
 391  */
 392
 393 #define D_STATES 1              /* [core] State transitions */
 394 #define D_ROUTES 2              /* [core] Routes passed by the filters */
 395 #define D_FILTERS 4             /* [core] Routes rejected by the filters */
 396 #define D_IFACES 8              /* [core] Interface events */
 397 #define D_EVENTS 16             /* Protocol events */
 398 #define D_PACKETS 32            /* Packets sent/received */
 399
 400 #ifndef PARSER
 401 #define TRACE(flags, msg, args...) \
 402   do { if (p->p.debug & flags) log(L_TRACE "%s: " msg, p->p.name , ## args ); } while(0)
 403 #endif
 404
 405
 406 /*
 407  *      MRTDump flags
 408  */
 409
 410 #define MD_STATES       1               /* Protocol state changes (BGP4MP_MESSAGE_AS4) */
 411 #define MD_MESSAGES     2               /* Protocol packets (BGP4MP_MESSAGE_AS4) */
 412
 413 /*
 414  *      Known unique protocol instances as referenced by config routines
 415  */
 416
 417 extern struct proto_config *cf_dev_proto;
 418
 419
 420 /*
 421  * Protocol limits
 422  */
 423
 424 #define PLD_RX          0       /* Receive limit */
 425 #define PLD_IN          1       /* Import limit */
 426 #define PLD_OUT         2       /* Export limit */
 427 #define PLD_MAX         3
 428
 429 #define PLA_NONE        0       /* No limit */
 430 #define PLA_WARN        1       /* Issue log warning */
 431 #define PLA_BLOCK       2       /* Block new routes */
 432 #define PLA_RESTART     4       /* Force protocol restart */
 433 #define PLA_DISABLE     5       /* Shutdown and disable protocol */
 434
 435 #define PLS_INITIAL     0       /* Initial limit state after protocol start */
 436 #define PLS_ACTIVE      1       /* Limit was hit */
 437 #define PLS_BLOCKED     2       /* Limit is active and blocking new routes */
 438
 439 struct channel_limit {
 440   u32 limit;                    /* Maximum number of prefixes */
 441   u8 action;                    /* Action to take (PLA_*) */
 442   u8 state;                     /* State of limit (PLS_*) */
 443 };
 444
 445 void channel_notify_limit(struct channel *c, struct channel_limit *l, int dir, u32 rt_count);
 446
 447
 448 /*
 449  *      Channels
 450  */
 451
 452 struct channel_class {
 453   uint channel_size;                    /* Size of channel data structure */
 454   uint config_size;                     /* Size of channel config data structure */
 455
 456   void (*init)(struct channel *, struct channel_config *);      /* Create new instance */
 457   int (*reconfigure)(struct channel *, struct channel_config *);        /* Try to reconfigure instance, returns success */
 458   int (*start)(struct channel *);       /* Start the instance */
 459   void (*shutdown)(struct channel *);   /* Stop the instance */
 460   void (*cleanup)(struct channel *);    /* Channel finished flush */
 461
 462   void (*copy_config)(struct channel_config *, struct channel_config *); /* Copy config from given channel instance */
 463 #if 0
 464   XXXX;
 465   void (*preconfig)(struct protocol *, struct config *);        /* Just before configuring */
 466   void (*postconfig)(struct proto_config *);                    /* After configuring each instance */
 467
 468
 469   void (*dump)(struct proto *);                 /* Debugging dump */
 470   void (*dump_attrs)(struct rte *);             /* Dump protocol-dependent attributes */
 471
 472   void (*get_status)(struct proto *, byte *buf); /* Get instance status (for `show protocols' command) */
 473   void (*get_route_info)(struct rte *, byte *buf); /* Get route information (for `show route' command) */
 474   int (*get_attr)(struct eattr *, byte *buf, int buflen);       /* ASCIIfy dynamic attribute (returns GA_*) */
 475   void (*show_proto_info)(struct proto *);      /* Show protocol info (for `show protocols all' command) */
 476
 477 #endif
 478 };
 479
 480 extern struct channel_class channel_bgp;
 481
 482 struct channel_config {
 483   node n;
 484   const char *name;
 485   const struct channel_class *channel;
 486
 487   struct proto_config *parent;          /* Where channel is defined (proto or template) */
 488   struct rtable_config *table;          /* Table we're attached to */
 489   struct filter *in_filter, *out_filter; /* Attached filters */
 490   struct channel_limit rx_limit;        /* Limit for receiving routes from protocol
 491                                            (relevant when in_keep_filtered is active) */
 492   struct channel_limit in_limit;        /* Limit for importing routes from protocol */
 493   struct channel_limit out_limit;       /* Limit for exporting routes to protocol */
 494
 495   u8 net_type;                          /* Routing table network type (NET_*), 0 for undefined */
 496   u8 ra_mode;                           /* Mode of received route advertisements (RA_*) */
 497   u16 preference;                       /* Default route preference */
 498   u8 merge_limit;                       /* Maximal number of nexthops for RA_MERGED */
 499   u8 in_keep_filtered;                  /* Routes rejected in import filter are kept */
 500 };
 501
 502 struct channel {
 503   node n;                               /* Node in proto->channels */
 504   node table_node;                      /* Node in table->channels */
 505
 506   const char *name;                     /* Channel name (may be NULL) */
 507   const struct channel_class *channel;
 508   struct proto *proto;
 509
 510   struct rtable *table;
 511   struct filter *in_filter;             /* Input filter */
 512   struct filter *out_filter;            /* Output filter */
 513   struct channel_limit rx_limit;        /* Receive limit (for in_keep_filtered) */
 514   struct channel_limit in_limit;        /* Input limit */
 515   struct channel_limit out_limit;       /* Output limit */
 516
 517   struct event *feed_event;             /* Event responsible for feeding */
 518   struct fib_iterator feed_fit;         /* Routing table iterator used during feeding */
 519   struct proto_stats stats;             /* Per-channel protocol statistics */
 520
 521   u8 net_type;                          /* Routing table network type (NET_*), 0 for undefined */
 522   u8 ra_mode;                           /* Mode of received route advertisements (RA_*) */
 523   u16 preference;                       /* Default route preference */
 524   u8 merge_limit;                       /* Maximal number of nexthops for RA_MERGED */
 525   u8 in_keep_filtered;                  /* Routes rejected in import filter are kept */
 526   u8 disabled;
 527   u8 stale;                             /* Used in reconfiguration */
 528
 529   u8 channel_state;
 530   u8 export_state;                      /* Route export state (ES_*, see below) */
 531   u8 feed_active;
 532   u8 flush_active;
 533   u8 refeeding;                         /* We are refeeding (valid only if export_state == ES_FEEDING) */
 534   u8 reloadable;                        /* Hook reload_routes() is allowed on the channel */
 535   u8 gr_lock;                           /* Graceful restart mechanism should wait for this channel */
 536   u8 gr_wait;                           /* Route export to channel is postponed until graceful restart */
 537
 538   btime last_state_change;              /* Time of last state transition */
 539 };
 540
 541
 542 /*
 543  * Channel states
 544  *
 545  * CS_DOWN - The initial and the final state of a channel. There is no route
 546  * exchange between the protocol and the table. Channel is not counted as
 547  * active. Channel keeps a ptr to the table, but do not lock the table and is
 548  * not linked in the table. Generally, new closed channels are created in
 549  * protocols' init() hooks. The protocol is expected to explicitly activate its
 550  * channels (by calling channel_init() or channel_open()).
 551  *
 552  * CS_START - The channel as a connection between the protocol and the table is
 553  * initialized (counted as active by the protocol, linked in the table and keeps
 554  * the table locked), but there is no current route exchange. There still may be
 555  * routes associated with the channel in the routing table if the channel falls
 556  * to CS_START from CS_UP. Generally, channels are initialized in protocols'
 557  * start() hooks when going to PS_START.
 558  *
 559  * CS_UP - The channel is initialized and the route exchange is allowed. Note
 560  * that even in CS_UP state, route export may still be down (ES_DOWN) by the
 561  * core decision (e.g. waiting for table convergence after graceful restart).
 562  * I.e., the protocol decides to open the channel but the core decides to start
 563  * route export. Route import (caused by rte_update() from the protocol) is not
 564  * restricted by that and is on volition of the protocol. Generally, channels
 565  * are opened in protocols' start() hooks when going to PS_UP.
 566  *
 567  * CS_FLUSHING - The transitional state between initialized channel and closed
 568  * channel. The channel is still initialized, but no route exchange is allowed.
 569  * Instead, the associated table is running flush loop to remove routes imported
 570  * through the channel. After that, the channel changes state to CS_DOWN and
 571  * is detached from the table (the table is unlocked and the channel is unlinked
 572  * from it). Unlike other states, the CS_FLUSHING state is not explicitly
 573  * entered or left by the protocol. A protocol may request to close a channel
 574  * (by calling channel_close()), which causes the channel to change state to
 575  * CS_FLUSHING and later to CS_DOWN. Also note that channels are closed
 576  * automatically by the core when the protocol is going down.
 577  *
 578  * Allowed transitions:
 579  *
 580  * CS_DOWN      -> CS_START / CS_UP
 581  * CS_START     -> CS_UP / CS_FLUSHING
 582  * CS_UP        -> CS_START / CS_FLUSHING
 583  * CS_FLUSHING  -> CS_DOWN (automatic)
 584  */
 585
 586 #define CS_DOWN         0
 587 #define CS_START        1
 588 #define CS_UP           2
 589 #define CS_FLUSHING     3
 590
 591 #define ES_DOWN         0
 592 #define ES_FEEDING      1
 593 #define ES_READY        2
 594
 595
 596 struct channel_config *proto_cf_find_channel(struct proto_config *p, uint net_type);
 597 static inline struct channel_config *proto_cf_main_channel(struct proto_config *pc)
 598 { struct channel_config *cc = HEAD(pc->channels); return NODE_VALID(cc) ? cc : NULL; }
 599
 600 struct channel *proto_find_channel_by_table(struct proto *p, struct rtable *t);
 601 struct channel *proto_find_channel_by_name(struct proto *p, const char *n);
 602 struct channel *proto_add_channel(struct proto *p, struct channel_config *cf);
 603 int proto_configure_channel(struct proto *p, struct channel **c, struct channel_config *cf);
 604
 605 void channel_set_state(struct channel *c, uint state);
 606
 607 static inline void channel_init(struct channel *c) { channel_set_state(c, CS_START); }
 608 static inline void channel_open(struct channel *c) { channel_set_state(c, CS_UP); }
 609 static inline void channel_close(struct channel *c) { channel_set_state(c, CS_FLUSHING); }
 610
 611 void channel_request_feeding(struct channel *c);
 612 void *channel_config_new(const struct channel_class *cc, const char *name, uint net_type, struct proto_config *proto);
 613 void *channel_config_get(const struct channel_class *cc, const char *name, uint net_type, struct proto_config *proto);
 614 int channel_reconfigure(struct channel *c, struct channel_config *cf);
 615
 616
 617 #endif