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bird/nest/protocol.h

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/*
* BIRD Internet Routing Daemon -- Protocols
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#ifndef _BIRD_PROTOCOL_H_
#define _BIRD_PROTOCOL_H_
#include "lib/lists.h"
#include "lib/resource.h"
#include "lib/event.h"
#include "nest/route.h"
#include "conf/conf.h"
struct iface;
struct ifa;
struct rtable;
struct rte;
struct neighbor;
struct rta;
struct network;
struct proto_config;
struct channel_limit;
struct channel_config;
struct config;
struct proto;
struct channel;
struct ea_list;
struct eattr;
struct symbol;
/*
* Routing Protocol
*/
struct protocol {
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node n;
char *name;
char *template; /* Template for automatic generation of names */
int name_counter; /* Counter for automatic name generation */
int attr_class; /* Attribute class known to this protocol */
uint preference; /* Default protocol preference */
uint channel_mask; /* Mask of accepted channel types (NB_*) */
uint proto_size; /* Size of protocol data structure */
uint config_size; /* Size of protocol config data structure */
void (*preconfig)(struct protocol *, struct config *); /* Just before configuring */
void (*postconfig)(struct proto_config *); /* After configuring each instance */
struct proto * (*init)(struct proto_config *); /* Create new instance */
int (*reconfigure)(struct proto *, struct proto_config *); /* Try to reconfigure instance, returns success */
void (*dump)(struct proto *); /* Debugging dump */
void (*dump_attrs)(struct rte *); /* Dump protocol-dependent attributes */
int (*start)(struct proto *); /* Start the instance */
int (*shutdown)(struct proto *); /* Stop the instance */
void (*cleanup)(struct proto *); /* Called after shutdown when protocol became hungry/down */
void (*get_status)(struct proto *, byte *buf); /* Get instance status (for `show protocols' command) */
void (*get_route_info)(struct rte *, byte *buf, struct ea_list *attrs); /* Get route information (for `show route' command) */
int (*get_attr)(struct eattr *, byte *buf, int buflen); /* ASCIIfy dynamic attribute (returns GA_*) */
void (*show_proto_info)(struct proto *); /* Show protocol info (for `show protocols all' command) */
void (*copy_config)(struct proto_config *, struct proto_config *); /* Copy config from given protocol instance */
};
void protos_build(void);
void proto_build(struct protocol *);
void protos_preconfig(struct config *);
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void protos_commit(struct config *new, struct config *old, int force_restart, int type);
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void protos_dump_all(void);
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#define GA_UNKNOWN 0 /* Attribute not recognized */
#define GA_NAME 1 /* Result = name */
#define GA_FULL 2 /* Result = both name and value */
/*
* Known protocols
*/
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extern struct protocol
proto_device, proto_radv, proto_rip, proto_static,
proto_ospf, proto_pipe, proto_bgp, proto_bfd, proto_babel, proto_rpki;
/*
* Routing Protocol Instance
*/
struct proto_config {
node n;
struct config *global; /* Global configuration data */
struct protocol *protocol; /* Protocol */
struct proto *proto; /* Instance we've created */
char *name;
char *dsc;
int class; /* SYM_PROTO or SYM_TEMPLATE */
u8 net_type; /* Protocol network type (NET_*), 0 for undefined */
u8 disabled; /* Protocol enabled/disabled by default */
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u32 debug, mrtdump; /* Debugging bitfields, both use D_* constants */
u32 router_id; /* Protocol specific router ID */
list channels; /* List of channel configs (struct channel_config) */
Basic VRF support Add basic VRF (virtual routing and forwarding) support. Protocols can be associated with VRFs, such protocols will be restricted to interfaces assigned to the VRF (as reported by Linux kernel) and will use sockets bound to the VRF. E.g., different multihop BGP instances can use diffent kernel routing tables to handle BGP TCP connections. The VRF support is preliminary, currently there are several limitations: - Recent Linux kernels (4.11) do not handle correctly sockets bound to interaces that are part of VRF, so most protocols other than multihop BGP do not work. This will be fixed by future kernel versions. - Neighbor cache ignores VRFs. Breaks config with the same prefix on local interfaces in different VRFs. Not much problem as single hop protocols do not work anyways. - Olock code ignores VRFs. Breaks config with multiple BGP peers with the same IP address in different VRFs. - Incoming BGP connections are not dispatched according to VRFs. Breaks config with multiple BGP peers with the same IP address in different VRFs. Perhaps we would need some kernel API to read VRF of incoming connection? Or probably use multiple listening sockets in int-new branch. - We should handle master VRF interface up/down events and perhaps disable associated protocols when VRF goes down. Or at least disable associated interfaces. - Also we should check if the master iface is really VRF iface and not some other kind of master iface. - BFD session request dispatch should be aware of VRFs. - Perhaps kernel protocol should read default kernel table ID from VRF iface so it is not necessary to configure it. - Perhaps we should have per-VRF default table.
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struct iface *vrf; /* Related VRF instance, NULL if global */
/* Check proto_reconfigure() and proto_copy_config() after changing struct proto_config */
/* Protocol-specific data follow... */
};
/* Protocol statistics */
struct proto_stats {
/* Import - from protocol to core */
u32 imp_routes; /* Number of routes successfully imported to the (adjacent) routing table */
u32 filt_routes; /* Number of routes rejected in import filter but kept in the routing table */
u32 imp_updates_received; /* Number of route updates received */
u32 imp_updates_invalid; /* Number of route updates rejected as invalid */
u32 imp_updates_filtered; /* Number of route updates rejected by filters */
u32 imp_updates_ignored; /* Number of route updates rejected as already in route table */
u32 imp_updates_accepted; /* Number of route updates accepted and imported */
u32 imp_withdraws_received; /* Number of route withdraws received */
u32 imp_withdraws_invalid; /* Number of route withdraws rejected as invalid */
u32 imp_withdraws_ignored; /* Number of route withdraws rejected as already not in route table */
u32 imp_withdraws_accepted; /* Number of route withdraws accepted and processed */
/* Export - from core to protocol */
u32 exp_routes; /* Number of routes successfully exported to the protocol */
u32 exp_updates_received; /* Number of route updates received */
u32 exp_updates_rejected; /* Number of route updates rejected by protocol */
u32 exp_updates_filtered; /* Number of route updates rejected by filters */
u32 exp_updates_accepted; /* Number of route updates accepted and exported */
u32 exp_withdraws_received; /* Number of route withdraws received */
u32 exp_withdraws_accepted; /* Number of route withdraws accepted and processed */
};
struct proto {
node n; /* Node in global proto_list */
struct protocol *proto; /* Protocol */
struct proto_config *cf; /* Configuration data */
struct proto_config *cf_new; /* Configuration we want to switch to after shutdown (NULL=delete) */
pool *pool; /* Pool containing local objects */
event *event; /* Protocol event */
list channels; /* List of channels to rtables (struct channel) */
struct channel *main_channel; /* Primary channel */
struct rte_src *main_source; /* Primary route source */
struct iface *vrf; /* Related VRF instance, NULL if global */
char *name; /* Name of this instance (== cf->name) */
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u32 debug; /* Debugging flags */
u32 mrtdump; /* MRTDump flags */
uint active_channels; /* Number of active channels */
byte net_type; /* Protocol network type (NET_*), 0 for undefined */
byte disabled; /* Manually disabled */
byte proto_state; /* Protocol state machine (PS_*, see below) */
byte active; /* From PS_START to cleanup after PS_STOP */
byte do_start; /* Start actions are scheduled */
byte do_stop; /* Stop actions are scheduled */
byte reconfiguring; /* We're shutting down due to reconfiguration */
byte gr_recovery; /* Protocol should participate in graceful restart recovery */
byte down_sched; /* Shutdown is scheduled for later (PDS_*) */
byte down_code; /* Reason for shutdown (PDC_* codes) */
u32 hash_key; /* Random key used for hashing of neighbors */
btime last_state_change; /* Time of last state transition */
char *last_state_name_announced; /* Last state name we've announced to the user */
char *message; /* State-change message, allocated from proto_pool */
/*
* General protocol hooks:
*
* if_notify Notify protocol about interface state changes.
* ifa_notify Notify protocol about interface address changes.
* rt_notify Notify protocol about routing table updates.
* neigh_notify Notify protocol about neighbor cache events.
* make_tmp_attrs Construct ea_list from private attrs stored in rte.
* store_tmp_attrs Store private attrs back to the rte.
* import_control Called as the first step of the route importing process.
* It can construct a new rte, add private attributes and
* decide whether the route shall be imported: 1=yes, -1=no,
* 0=process it through the import filter set by the user.
* reload_routes Request channel to reload all its routes to the core
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* (using rte_update()). Returns: 0=reload cannot be done,
* 1= reload is scheduled and will happen (asynchronously).
* feed_begin Notify channel about beginning of route feeding.
* feed_end Notify channel about finish of route feeding.
*/
void (*if_notify)(struct proto *, unsigned flags, struct iface *i);
void (*ifa_notify)(struct proto *, unsigned flags, struct ifa *a);
void (*rt_notify)(struct proto *, struct channel *, struct network *net, struct rte *new, struct rte *old, struct ea_list *attrs);
void (*neigh_notify)(struct neighbor *neigh);
struct ea_list *(*make_tmp_attrs)(struct rte *rt, struct linpool *pool);
void (*store_tmp_attrs)(struct rte *rt, struct ea_list *attrs);
int (*import_control)(struct proto *, struct rte **rt, struct ea_list **attrs, struct linpool *pool);
void (*reload_routes)(struct channel *);
void (*feed_begin)(struct channel *, int initial);
void (*feed_end)(struct channel *);
/*
* Routing entry hooks (called only for routes belonging to this protocol):
*
* rte_recalculate Called at the beginning of the best route selection
* rte_better Compare two rte's and decide which one is better (1=first, 0=second).
* rte_same Compare two rte's and decide whether they are identical (1=yes, 0=no).
* rte_mergable Compare two rte's and decide whether they could be merged (1=yes, 0=no).
* rte_insert Called whenever a rte is inserted to a routing table.
* rte_remove Called whenever a rte is removed from the routing table.
*/
int (*rte_recalculate)(struct rtable *, struct network *, struct rte *, struct rte *, struct rte *);
int (*rte_better)(struct rte *, struct rte *);
int (*rte_same)(struct rte *, struct rte *);
int (*rte_mergable)(struct rte *, struct rte *);
void (*rte_insert)(struct network *, struct rte *);
void (*rte_remove)(struct network *, struct rte *);
/* Hic sunt protocol-specific data */
};
struct proto_spec {
void *ptr;
int patt;
};
#define PDS_DISABLE 1 /* Proto disable scheduled */
#define PDS_RESTART 2 /* Proto restart scheduled */
#define PDC_CF_REMOVE 0x01 /* Removed in new config */
#define PDC_CF_DISABLE 0x02 /* Disabled in new config */
#define PDC_CF_RESTART 0x03 /* Restart due to reconfiguration */
#define PDC_CMD_DISABLE 0x11 /* Result of disable command */
#define PDC_CMD_RESTART 0x12 /* Result of restart command */
#define PDC_CMD_SHUTDOWN 0x13 /* Result of global shutdown */
#define PDC_RX_LIMIT_HIT 0x21 /* Route receive limit reached */
#define PDC_IN_LIMIT_HIT 0x22 /* Route import limit reached */
#define PDC_OUT_LIMIT_HIT 0x23 /* Route export limit reached */
void *proto_new(struct proto_config *);
void *proto_config_new(struct protocol *, int class);
void proto_copy_config(struct proto_config *dest, struct proto_config *src);
void proto_set_message(struct proto *p, char *msg, int len);
void graceful_restart_recovery(void);
void graceful_restart_init(void);
void graceful_restart_show_status(void);
void channel_graceful_restart_lock(struct channel *c);
void channel_graceful_restart_unlock(struct channel *c);
#define DEFAULT_GR_WAIT 240
void channel_show_limit(struct channel_limit *l, const char *dsc);
void channel_show_info(struct channel *c);
void proto_cmd_show(struct proto *, uintptr_t, int);
void proto_cmd_disable(struct proto *, uintptr_t, int);
void proto_cmd_enable(struct proto *, uintptr_t, int);
void proto_cmd_restart(struct proto *, uintptr_t, int);
void proto_cmd_reload(struct proto *, uintptr_t, int);
void proto_cmd_debug(struct proto *, uintptr_t, int);
void proto_cmd_mrtdump(struct proto *, uintptr_t, int);
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void proto_apply_cmd(struct proto_spec ps, void (* cmd)(struct proto *, uintptr_t, int), int restricted, uintptr_t arg);
struct proto *proto_get_named(struct symbol *, struct protocol *);
#define CMD_RELOAD 0
#define CMD_RELOAD_IN 1
#define CMD_RELOAD_OUT 2
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static inline u32
proto_get_router_id(struct proto_config *pc)
{
return pc->router_id ? pc->router_id : pc->global->router_id;
}
static inline struct ea_list *
rte_make_tmp_attrs(struct rte *rt, struct linpool *pool)
{
struct ea_list *(*mta)(struct rte *rt, struct linpool *pool);
mta = rt->attrs->src->proto->make_tmp_attrs;
return mta ? mta(rt, pool) : NULL;
}
/* Moved from route.h to avoid dependency conflicts */
static inline void rte_update(struct proto *p, const net_addr *n, rte *new) { rte_update2(p->main_channel, n, new, p->main_source); }
extern pool *proto_pool;
extern list proto_list;
/*
* Each protocol instance runs two different state machines:
*
* [P] The protocol machine: (implemented inside protocol)
*
* DOWN ----> START
* ^ |
* | V
* STOP <---- UP
*
* States: DOWN Protocol is down and it's waiting for the core
* requesting protocol start.
* START Protocol is waiting for connection with the rest
* of the network and it's not willing to accept
* packets. When it connects, it goes to UP state.
* UP Protocol is up and running. When the network
* connection breaks down or the core requests
* protocol to be terminated, it goes to STOP state.
* STOP Protocol is disconnecting from the network.
* After it disconnects, it returns to DOWN state.
*
* In: start() Called in DOWN state to request protocol startup.
* Returns new state: either UP or START (in this
* case, the protocol will notify the core when it
* finally comes UP).
* stop() Called in START, UP or STOP state to request
* protocol shutdown. Returns new state: either
* DOWN or STOP (in this case, the protocol will
* notify the core when it finally comes DOWN).
*
* Out: proto_notify_state() -- called by protocol instance when
* it does any state transition not covered by
* return values of start() and stop(). This includes
* START->UP (delayed protocol startup), UP->STOP
* (spontaneous shutdown) and STOP->DOWN (delayed
* shutdown).
*/
#define PS_DOWN 0
#define PS_START 1
#define PS_UP 2
#define PS_STOP 3
void proto_notify_state(struct proto *p, unsigned state);
/*
* [F] The feeder machine: (implemented in core routines)
*
* HUNGRY ----> FEEDING
* ^ |
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* | V
* FLUSHING <---- HAPPY
*
* States: HUNGRY Protocol either administratively down (i.e.,
* disabled by the user) or temporarily down
* (i.e., [P] is not UP)
* FEEDING The protocol came up and we're feeding it
* initial routes. [P] is UP.
* HAPPY The protocol is up and it's receiving normal
* routing updates. [P] is UP.
* FLUSHING The protocol is down and we're removing its
* routes from the table. [P] is STOP or DOWN.
*
* Normal lifecycle of a protocol looks like:
*
* HUNGRY/DOWN --> HUNGRY/START --> HUNGRY/UP -->
* FEEDING/UP --> HAPPY/UP --> FLUSHING/STOP|DOWN -->
* HUNGRY/STOP|DOWN --> HUNGRY/DOWN
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*
* Sometimes, protocol might switch from HAPPY/UP to FEEDING/UP
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* if it wants to refeed the routes (for example BGP does so
* as a result of received ROUTE-REFRESH request).
*/
Added protocol debugging flags (protocol.h: D_xxx), parsing of them in configuration files and commands for manipulating them. Current debug message policy: o D_STATES, D_ROUTES and D_FILTERS are handled in generic code. o Other debug flags should be handled in the protocols and whenever the flag is set, the corresponding messages should be printed using calls to log(L_TRACE, ...), each message prefixed with the name of the protocol instance. These messages should cover the whole normal operation of the protocol and should be useful for an administrator trying to understand what does the protocol behave on his network or who is attempting to diagnose network problems. If your messages don't fit to the categories I've defined, feel free to add your own ones (by adding them to protocol.h and on two places in nest/config.Y), but please try to keep the categories as general as possible (i.e., not tied to your protocol). o Internal debug messages not interesting even to an experienced user should be printed by calling DBG() which is either void or a call to debug() depending on setting of the LOCAL_DEBUG symbol at the top of your source. o Dump functions (proto->dump etc.) should call debug() to print their messages. o If you are doing any internal consistency checks, use ASSERT or bug(). o Nobody shall ever call printf() or any other stdio functions. Also please try to log any protocol errors you encounter and tag them with the appropriate message category (usually L_REMOTE or L_AUTH). Always carefully check contents of any message field you receive and verify all IP addresses you work with (by calling ipa_classify() or by using the neighbour cache if you want to check direct connectedness as well).
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/*
* Debugging flags
*/
#define D_STATES 1 /* [core] State transitions */
#define D_ROUTES 2 /* [core] Routes passed by the filters */
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#define D_FILTERS 4 /* [core] Routes rejected by the filters */
#define D_IFACES 8 /* [core] Interface events */
#define D_EVENTS 16 /* Protocol events */
#define D_PACKETS 32 /* Packets sent/received */
Added protocol debugging flags (protocol.h: D_xxx), parsing of them in configuration files and commands for manipulating them. Current debug message policy: o D_STATES, D_ROUTES and D_FILTERS are handled in generic code. o Other debug flags should be handled in the protocols and whenever the flag is set, the corresponding messages should be printed using calls to log(L_TRACE, ...), each message prefixed with the name of the protocol instance. These messages should cover the whole normal operation of the protocol and should be useful for an administrator trying to understand what does the protocol behave on his network or who is attempting to diagnose network problems. If your messages don't fit to the categories I've defined, feel free to add your own ones (by adding them to protocol.h and on two places in nest/config.Y), but please try to keep the categories as general as possible (i.e., not tied to your protocol). o Internal debug messages not interesting even to an experienced user should be printed by calling DBG() which is either void or a call to debug() depending on setting of the LOCAL_DEBUG symbol at the top of your source. o Dump functions (proto->dump etc.) should call debug() to print their messages. o If you are doing any internal consistency checks, use ASSERT or bug(). o Nobody shall ever call printf() or any other stdio functions. Also please try to log any protocol errors you encounter and tag them with the appropriate message category (usually L_REMOTE or L_AUTH). Always carefully check contents of any message field you receive and verify all IP addresses you work with (by calling ipa_classify() or by using the neighbour cache if you want to check direct connectedness as well).
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#ifndef PARSER
#define TRACE(flags, msg, args...) \
do { if (p->p.debug & flags) log(L_TRACE "%s: " msg, p->p.name , ## args ); } while(0)
#endif
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/*
* MRTDump flags
*/
#define MD_STATES 1 /* Protocol state changes (BGP4MP_MESSAGE_AS4) */
#define MD_MESSAGES 2 /* Protocol packets (BGP4MP_MESSAGE_AS4) */
/*
* Known unique protocol instances as referenced by config routines
*/
extern struct proto_config *cf_dev_proto;
/*
* Protocol limits
*/
#define PLD_RX 0 /* Receive limit */
#define PLD_IN 1 /* Import limit */
#define PLD_OUT 2 /* Export limit */
#define PLD_MAX 3
#define PLA_NONE 0 /* No limit */
#define PLA_WARN 1 /* Issue log warning */
#define PLA_BLOCK 2 /* Block new routes */
#define PLA_RESTART 4 /* Force protocol restart */
#define PLA_DISABLE 5 /* Shutdown and disable protocol */
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#define PLS_INITIAL 0 /* Initial limit state after protocol start */
#define PLS_ACTIVE 1 /* Limit was hit */
#define PLS_BLOCKED 2 /* Limit is active and blocking new routes */
struct channel_limit {
u32 limit; /* Maximum number of prefixes */
u8 action; /* Action to take (PLA_*) */
u8 state; /* State of limit (PLS_*) */
};
void channel_notify_limit(struct channel *c, struct channel_limit *l, int dir, u32 rt_count);
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/*
* Channels
*/
struct channel_class {
uint channel_size; /* Size of channel data structure */
uint config_size; /* Size of channel config data structure */
void (*init)(struct channel *, struct channel_config *); /* Create new instance */
int (*reconfigure)(struct channel *, struct channel_config *); /* Try to reconfigure instance, returns success */
int (*start)(struct channel *); /* Start the instance */
void (*shutdown)(struct channel *); /* Stop the instance */
void (*cleanup)(struct channel *); /* Channel finished flush */
void (*copy_config)(struct channel_config *, struct channel_config *); /* Copy config from given channel instance */
#if 0
XXXX;
void (*preconfig)(struct protocol *, struct config *); /* Just before configuring */
void (*postconfig)(struct proto_config *); /* After configuring each instance */
void (*dump)(struct proto *); /* Debugging dump */
void (*dump_attrs)(struct rte *); /* Dump protocol-dependent attributes */
void (*get_status)(struct proto *, byte *buf); /* Get instance status (for `show protocols' command) */
void (*get_route_info)(struct rte *, byte *buf, struct ea_list *attrs); /* Get route information (for `show route' command) */
int (*get_attr)(struct eattr *, byte *buf, int buflen); /* ASCIIfy dynamic attribute (returns GA_*) */
void (*show_proto_info)(struct proto *); /* Show protocol info (for `show protocols all' command) */
#endif
};
extern struct channel_class channel_bgp;
struct channel_config {
node n;
const char *name;
const struct channel_class *channel;
struct proto_config *parent; /* Where channel is defined (proto or template) */
struct rtable_config *table; /* Table we're attached to */
struct filter *in_filter, *out_filter; /* Attached filters */
struct channel_limit rx_limit; /* Limit for receiving routes from protocol
(relevant when in_keep_filtered is active) */
struct channel_limit in_limit; /* Limit for importing routes from protocol */
struct channel_limit out_limit; /* Limit for exporting routes to protocol */
u8 net_type; /* Routing table network type (NET_*), 0 for undefined */
u8 ra_mode; /* Mode of received route advertisements (RA_*) */
u16 preference; /* Default route preference */
u8 merge_limit; /* Maximal number of nexthops for RA_MERGED */
u8 in_keep_filtered; /* Routes rejected in import filter are kept */
};
struct channel {
node n; /* Node in proto->channels */
node table_node; /* Node in table->channels */
const char *name; /* Channel name (may be NULL) */
const struct channel_class *channel;
struct proto *proto;
struct rtable *table;
struct filter *in_filter; /* Input filter */
struct filter *out_filter; /* Output filter */
struct channel_limit rx_limit; /* Receive limit (for in_keep_filtered) */
struct channel_limit in_limit; /* Input limit */
struct channel_limit out_limit; /* Output limit */
struct event *feed_event; /* Event responsible for feeding */
struct fib_iterator feed_fit; /* Routing table iterator used during feeding */
struct proto_stats stats; /* Per-channel protocol statistics */
u8 net_type; /* Routing table network type (NET_*), 0 for undefined */
u8 ra_mode; /* Mode of received route advertisements (RA_*) */
u16 preference; /* Default route preference */
u8 merge_limit; /* Maximal number of nexthops for RA_MERGED */
u8 in_keep_filtered; /* Routes rejected in import filter are kept */
u8 disabled;
u8 stale; /* Used in reconfiguration */
u8 channel_state;
u8 export_state; /* Route export state (ES_*, see below) */
u8 feed_active;
u8 flush_active;
u8 refeeding; /* We are refeeding (valid only if export_state == ES_FEEDING) */
u8 reloadable; /* Hook reload_routes() is allowed on the channel */
u8 gr_lock; /* Graceful restart mechanism should wait for this channel */
u8 gr_wait; /* Route export to channel is postponed until graceful restart */
btime last_state_change; /* Time of last state transition */
};
/*
* Channel states
*
* CS_DOWN - The initial and the final state of a channel. There is no route
* exchange between the protocol and the table. Channel is not counted as
* active. Channel keeps a ptr to the table, but do not lock the table and is
* not linked in the table. Generally, new closed channels are created in
* protocols' init() hooks. The protocol is expected to explicitly activate its
* channels (by calling channel_init() or channel_open()).
*
* CS_START - The channel as a connection between the protocol and the table is
* initialized (counted as active by the protocol, linked in the table and keeps
* the table locked), but there is no current route exchange. There still may be
* routes associated with the channel in the routing table if the channel falls
* to CS_START from CS_UP. Generally, channels are initialized in protocols'
* start() hooks when going to PS_START.
*
* CS_UP - The channel is initialized and the route exchange is allowed. Note
* that even in CS_UP state, route export may still be down (ES_DOWN) by the
* core decision (e.g. waiting for table convergence after graceful restart).
* I.e., the protocol decides to open the channel but the core decides to start
* route export. Route import (caused by rte_update() from the protocol) is not
* restricted by that and is on volition of the protocol. Generally, channels
* are opened in protocols' start() hooks when going to PS_UP.
*
* CS_FLUSHING - The transitional state between initialized channel and closed
* channel. The channel is still initialized, but no route exchange is allowed.
* Instead, the associated table is running flush loop to remove routes imported
* through the channel. After that, the channel changes state to CS_DOWN and
* is detached from the table (the table is unlocked and the channel is unlinked
* from it). Unlike other states, the CS_FLUSHING state is not explicitly
* entered or left by the protocol. A protocol may request to close a channel
* (by calling channel_close()), which causes the channel to change state to
* CS_FLUSHING and later to CS_DOWN. Also note that channels are closed
* automatically by the core when the protocol is going down.
*
* Allowed transitions:
*
* CS_DOWN -> CS_START / CS_UP
* CS_START -> CS_UP / CS_FLUSHING
* CS_UP -> CS_START / CS_FLUSHING
* CS_FLUSHING -> CS_DOWN (automatic)
*/
#define CS_DOWN 0
#define CS_START 1
#define CS_UP 2
#define CS_FLUSHING 3
#define ES_DOWN 0
#define ES_FEEDING 1
#define ES_READY 2
struct channel_config *proto_cf_find_channel(struct proto_config *p, uint net_type);
static inline struct channel_config *proto_cf_main_channel(struct proto_config *pc)
{ struct channel_config *cc = HEAD(pc->channels); return NODE_VALID(cc) ? cc : NULL; }
struct channel *proto_find_channel_by_table(struct proto *p, struct rtable *t);
struct channel *proto_find_channel_by_name(struct proto *p, const char *n);
struct channel *proto_add_channel(struct proto *p, struct channel_config *cf);
int proto_configure_channel(struct proto *p, struct channel **c, struct channel_config *cf);
void channel_set_state(struct channel *c, uint state);
static inline void channel_init(struct channel *c) { channel_set_state(c, CS_START); }
static inline void channel_open(struct channel *c) { channel_set_state(c, CS_UP); }
static inline void channel_close(struct channel *c) { channel_set_state(c, CS_FLUSHING); }
void channel_request_feeding(struct channel *c);
void *channel_config_new(const struct channel_class *cc, const char *name, uint net_type, struct proto_config *proto);
void *channel_config_get(const struct channel_class *cc, const char *name, uint net_type, struct proto_config *proto);
int channel_reconfigure(struct channel *c, struct channel_config *cf);
#endif