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Diffstat (limited to 'nest/rt.h')
| -rw-r--r-- | nest/rt.h | 589 |
1 files changed, 589 insertions, 0 deletions
diff --git a/nest/rt.h b/nest/rt.h new file mode 100644 index 00000000..1a6b7a93 --- /dev/null +++ b/nest/rt.h @@ -0,0 +1,589 @@ +/* + * BIRD Internet Routing Daemon -- Routing Table + * + * (c) 1998--2000 Martin Mares <mj@ucw.cz> + * (c) 2019--2021 Maria Matejka <mq@jmq.cz> + * + * Can be freely distributed and used under the terms of the GNU GPL. + */ + +#ifndef _BIRD_NEST_RT_H_ +#define _BIRD_NEST_RT_H_ + +#include "lib/lists.h" +#include "lib/bitmap.h" +#include "lib/resource.h" +#include "lib/net.h" +#include "lib/type.h" +#include "lib/fib.h" +#include "lib/route.h" +#include "lib/event.h" +#include "lib/rcu.h" + +#include <stdatomic.h> + +struct ea_list; +struct protocol; +struct proto; +struct channel; +struct rte_src; +struct symbol; +struct timer; +struct filter; +struct f_trie; +struct f_trie_walk_state; +struct cli; + +struct rt_cork_threshold { + u64 low, high; +}; + +/* + * Master Routing Tables. Generally speaking, each of them contains a FIB + * with each entry pointing to a list of route entries representing routes + * to given network (with the selected one at the head). + * + * Each of the RTE's contains variable data (the preference and protocol-dependent + * metrics) and a pointer to a route attribute block common for many routes). + * + * It's guaranteed that there is at most one RTE for every (prefix,proto) pair. + */ + +struct rtable_config { + node n; + char *name; + struct rtable *table; + struct proto_config *krt_attached; /* Kernel syncer attached to this table */ + uint addr_type; /* Type of address data stored in table (NET_*) */ + uint gc_threshold; /* Maximum number of operations before GC is run */ + uint gc_period; /* Approximate time between two consecutive GC runs */ + byte sorted; /* Routes of network are sorted according to rte_better() */ + byte trie_used; /* Rtable has attached trie */ + btime min_settle_time; /* Minimum settle time for notifications */ + btime max_settle_time; /* Maximum settle time for notifications */ + btime export_settle_time; /* Delay before exports are announced */ + struct rt_cork_threshold cork_threshold; /* Cork threshold values */ +}; + +struct rt_export_hook; +struct rt_export_request; + +struct rt_exporter { + list hooks; /* Registered route export hooks */ + uint addr_type; /* Type of address data exported (NET_*) */ + + struct rt_export_hook *(*start)(struct rt_exporter *, struct rt_export_request *); + void (*stop)(struct rt_export_hook *); + void (*done)(struct rt_export_hook *); + void (*used)(struct rt_exporter *); + + list pending; /* List of packed struct rt_pending_export */ + struct timer *export_timer; + + struct rt_pending_export *first; /* First export to announce */ + u64 next_seq; /* The next export will have this ID */ +}; + +typedef struct rtable { + resource r; + node n; /* Node in list of all tables */ + pool *rp; /* Resource pool to allocate everything from, including itself */ + struct slab *rte_slab; /* Slab to allocate route objects */ + struct fib fib; + struct f_trie *trie; /* Trie of prefixes defined in fib */ + char *name; /* Name of this table */ + uint addr_type; /* Type of address data stored in table (NET_*) */ + int use_count; /* Number of protocols using this table */ + u32 rt_count; /* Number of routes in the table */ + + list imports; /* Registered route importers */ + struct rt_exporter exporter; /* Exporter API structure */ + + struct hmap id_map; + struct hostcache *hostcache; + struct rtable_config *config; /* Configuration of this table */ + struct config *deleted; /* Table doesn't exist in current configuration, + * delete as soon as use_count becomes 0 and remove + * obstacle from this routing table. + */ + struct event *rt_event; /* Routing table event */ + struct event *uncork_event; /* Called when uncork happens */ + struct timer *prune_timer; /* Timer for periodic pruning / GC */ + btime last_rt_change; /* Last time when route changed */ + btime base_settle_time; /* Start time of rtable settling interval */ + btime gc_time; /* Time of last GC */ + uint gc_counter; /* Number of operations since last GC */ + byte prune_state; /* Table prune state, 1 -> scheduled, 2-> running */ + byte prune_trie; /* Prune prefix trie during next table prune */ + byte hcu_scheduled; /* Hostcache update is scheduled */ + byte hcu_corked; /* Hostcache update is corked with this state */ + byte nhu_state; /* Next Hop Update state */ + byte nhu_corked; /* Next Hop Update is corked with this state */ + byte export_used; /* Pending Export pruning is scheduled */ + byte cork_active; /* Cork has been activated */ + struct rt_cork_threshold cork_threshold; /* Threshold for table cork */ + struct fib_iterator prune_fit; /* Rtable prune FIB iterator */ + struct fib_iterator nhu_fit; /* Next Hop Update FIB iterator */ + struct f_trie *trie_new; /* New prefix trie defined during pruning */ + struct f_trie *trie_old; /* Old prefix trie waiting to be freed */ + u32 trie_lock_count; /* Prefix trie locked by walks */ + u32 trie_old_lock_count; /* Old prefix trie locked by walks */ + struct tbf rl_pipe; /* Rate limiting token buffer for pipe collisions */ + + list subscribers; /* Subscribers for notifications */ + struct timer *settle_timer; /* Settle time for notifications */ + list flowspec_links; /* List of flowspec links, src for NET_IPx and dst for NET_FLOWx */ + struct f_trie *flowspec_trie; /* Trie for evaluation of flowspec notifications */ +} rtable; + +struct rt_subscription { + node n; + rtable *tab; + event *event; + event_list *list; +}; + +struct rt_flowspec_link { + node n; + rtable *src; + rtable *dst; + u32 uc; +}; + +extern struct rt_cork { + _Atomic uint active; + event_list queue; + event run; +} rt_cork; + +static inline void rt_cork_acquire(void) +{ + atomic_fetch_add_explicit(&rt_cork.active, 1, memory_order_acq_rel); +} + +static inline void rt_cork_release(void) +{ + if (atomic_fetch_sub_explicit(&rt_cork.active, 1, memory_order_acq_rel) == 1) + { + synchronize_rcu(); + ev_schedule_work(&rt_cork.run); + } +} + +static inline int rt_cork_check(event *e) +{ + rcu_read_lock(); + + int corked = (atomic_load_explicit(&rt_cork.active, memory_order_acquire) > 0); + if (corked) + ev_send(&rt_cork.queue, e); + + rcu_read_unlock(); + + return corked; +} + + +#define NHU_CLEAN 0 +#define NHU_SCHEDULED 1 +#define NHU_RUNNING 2 +#define NHU_DIRTY 3 + +typedef struct network { + struct rte_storage *routes; /* Available routes for this network */ + struct rt_pending_export *first, *last; + struct fib_node n; /* FIB flags reserved for kernel syncer */ +} net; + +struct hostcache { + slab *slab; /* Slab holding all hostentries */ + struct hostentry **hash_table; /* Hash table for hostentries */ + unsigned hash_order, hash_shift; + unsigned hash_max, hash_min; + unsigned hash_items; + linpool *lp; /* Linpool for trie */ + struct f_trie *trie; /* Trie of prefixes that might affect hostentries */ + list hostentries; /* List of all hostentries */ + byte update_hostcache; +}; + +struct hostentry { + node ln; + ip_addr addr; /* IP address of host, part of key */ + ip_addr link; /* (link-local) IP address of host, used as gw + if host is directly attached */ + struct rtable *tab; /* Dependent table, part of key */ + struct hostentry *next; /* Next in hash chain */ + unsigned hash_key; /* Hash key */ + unsigned uc; /* Use count */ + ea_list *src; /* Source attributes */ + byte nexthop_linkable; /* Nexthop list is completely non-device */ + u32 igp_metric; /* Chosen route IGP metric */ +}; + +struct rte_storage { + struct rte_storage *next; /* Next in chain */ + struct rte rte; /* Route data */ +}; + +#define RTE_COPY(r) ((r) ? (r)->rte : (rte) {}) +#define RTE_COPY_VALID(r) (((r) && (rte_is_valid(&(r)->rte))) ? (r)->rte : (rte) {}) +#define RTE_OR_NULL(r) ((r) ? &((r)->rte) : NULL) +#define RTE_VALID_OR_NULL(r) (((r) && (rte_is_valid(&(r)->rte))) ? &((r)->rte) : NULL) + +/* Table-channel connections */ + +struct rt_import_request { + struct rt_import_hook *hook; /* The table part of importer */ + char *name; + u8 trace_routes; + + void (*dump_req)(struct rt_import_request *req); + void (*log_state_change)(struct rt_import_request *req, u8 state); + /* Preimport is called when the @new route is just-to-be inserted, replacing @old. + * Return a route (may be different or modified in-place) to continue or NULL to withdraw. */ + int (*preimport)(struct rt_import_request *req, struct rte *new, struct rte *old); +}; + +struct rt_import_hook { + node n; + rtable *table; /* The connected table */ + struct rt_import_request *req; /* The requestor */ + + struct rt_import_stats { + /* Import - from protocol to core */ + u32 pref; /* Number of routes selected as best in the (adjacent) routing table */ + u32 updates_ignored; /* Number of route updates rejected as already in route table */ + u32 updates_accepted; /* Number of route updates accepted and imported */ + u32 withdraws_ignored; /* Number of route withdraws rejected as already not in route table */ + u32 withdraws_accepted; /* Number of route withdraws accepted and processed */ + } stats; + + u64 flush_seq; /* Table export seq when the channel announced flushing */ + btime last_state_change; /* Time of last state transition */ + + u8 import_state; /* IS_* */ + u8 stale_set; /* Set this stale_cycle to imported routes */ + u8 stale_valid; /* Routes with this stale_cycle and bigger are considered valid */ + u8 stale_pruned; /* Last prune finished when this value was set at stale_valid */ + u8 stale_pruning; /* Last prune started when this value was set at stale_valid */ + + void (*stopped)(struct rt_import_request *); /* Stored callback when import is stopped */ +}; + +struct rt_pending_export { + struct rt_pending_export * _Atomic next; /* Next export for the same destination */ + struct rte_storage *new, *new_best, *old, *old_best; + u64 seq; /* Sequential ID (table-local) of the pending export */ +}; + +struct rt_export_request { + struct rt_export_hook *hook; /* Table part of the export */ + char *name; + const net_addr *addr; /* Network prefilter address */ + u8 trace_routes; + u8 addr_mode; /* Network prefilter mode (TE_ADDR_*) */ + + event_list *list; /* Where to schedule export events */ + + /* There are two methods of export. You can either request feeding every single change + * or feeding the whole route feed. In case of regular export, &export_one is preferred. + * Anyway, when feeding, &export_bulk is preferred, falling back to &export_one. + * Thus, for RA_OPTIMAL, &export_one is only set, + * for RA_MERGED and RA_ACCEPTED, &export_bulk is only set + * and for RA_ANY, both are set to accomodate for feeding all routes but receiving single changes + */ + void (*export_one)(struct rt_export_request *req, const net_addr *net, struct rt_pending_export *rpe); + void (*export_bulk)(struct rt_export_request *req, const net_addr *net, struct rt_pending_export *rpe, rte **feed, uint count); + + void (*dump_req)(struct rt_export_request *req); + void (*log_state_change)(struct rt_export_request *req, u8); +}; + +struct rt_export_hook { + node n; + struct rt_exporter *table; /* The connected table */ + + pool *pool; + + struct rt_export_request *req; /* The requestor */ + + struct rt_export_stats { + /* Export - from core to protocol */ + u32 updates_received; /* Number of route updates received */ + u32 withdraws_received; /* Number of route withdraws received */ + } stats; + + union { + struct fib_iterator feed_fit; /* Routing table iterator used during feeding */ + struct { + struct f_trie_walk_state *walk_state; /* Iterator over networks in trie */ + struct f_trie *walk_lock; /* Locked trie for walking */ + }; + u32 hash_iter; /* Iterator over hash */ + }; + + struct bmap seq_map; /* Keep track which exports were already procesed */ + + struct rt_pending_export * _Atomic last_export;/* Last export processed */ + struct rt_pending_export *rpe_next; /* Next pending export to process */ + + btime last_state_change; /* Time of last state transition */ + + u8 refeed_pending; /* Refeeding and another refeed is scheduled */ + _Atomic u8 export_state; /* Route export state (TES_*, see below) */ + u8 feed_type; /* Which feeding method is used (TFT_*, see below) */ + + struct event *event; /* Event running all the export operations */ + + void (*stopped)(struct rt_export_request *); /* Stored callback when export is stopped */ +}; + +#define TIS_DOWN 0 +#define TIS_UP 1 +#define TIS_STOP 2 +#define TIS_FLUSHING 3 +#define TIS_WAITING 4 +#define TIS_CLEARED 5 +#define TIS_MAX 6 + +#define TES_DOWN 0 +#define TES_FEEDING 2 +#define TES_READY 3 +#define TES_STOP 4 +#define TES_MAX 5 + +/* Value of addr_mode */ +#define TE_ADDR_NONE 0 /* No address matching */ +#define TE_ADDR_EQUAL 1 /* Exact query - show route <addr> */ +#define TE_ADDR_FOR 2 /* Longest prefix match - show route for <addr> */ +#define TE_ADDR_IN 3 /* Interval query - show route in <addr> */ + + +#define TFT_FIB 1 +#define TFT_TRIE 2 +#define TFT_HASH 3 + +void rt_request_import(rtable *tab, struct rt_import_request *req); +void rt_request_export(struct rt_exporter *tab, struct rt_export_request *req); + +void rt_export_once(struct rt_exporter *tab, struct rt_export_request *req); + +void rt_stop_import(struct rt_import_request *, void (*stopped)(struct rt_import_request *)); +void rt_stop_export(struct rt_export_request *, void (*stopped)(struct rt_export_request *)); + +const char *rt_import_state_name(u8 state); +const char *rt_export_state_name(u8 state); + +static inline u8 rt_import_get_state(struct rt_import_hook *ih) { return ih ? ih->import_state : TIS_DOWN; } +static inline u8 rt_export_get_state(struct rt_export_hook *eh) { return eh ? eh->export_state : TES_DOWN; } + +void rt_set_export_state(struct rt_export_hook *hook, u8 state); + +void rte_import(struct rt_import_request *req, const net_addr *net, rte *new, struct rte_src *src); + +/* Get next rpe. If src is given, it must match. */ +struct rt_pending_export *rpe_next(struct rt_pending_export *rpe, struct rte_src *src); + +/* Mark the pending export processed */ +void rpe_mark_seen(struct rt_export_hook *hook, struct rt_pending_export *rpe); + +/* Get pending export seen status */ +int rpe_get_seen(struct rt_export_hook *hook, struct rt_pending_export *rpe); + +/* Types of route announcement, also used as flags */ +#define RA_UNDEF 0 /* Undefined RA type */ +#define RA_OPTIMAL 1 /* Announcement of optimal route change */ +#define RA_ACCEPTED 2 /* Announcement of first accepted route */ +#define RA_ANY 3 /* Announcement of any route change */ +#define RA_MERGED 4 /* Announcement of optimal route merged with next ones */ + +/* Return value of preexport() callback */ +#define RIC_ACCEPT 1 /* Accepted by protocol */ +#define RIC_PROCESS 0 /* Process it through import filter */ +#define RIC_REJECT -1 /* Rejected by protocol */ +#define RIC_DROP -2 /* Silently dropped by protocol */ + +#define rte_update channel_rte_import +/** + * rte_update - enter a new update to a routing table + * @c: channel doing the update + * @net: network address + * @rte: a &rte representing the new route + * @src: old route source identifier + * + * This function imports a new route to the appropriate table (via the channel). + * Table keys are @net (obligatory) and @rte->attrs->src. + * Both the @net and @rte pointers can be local. + * + * The route attributes (@rte->attrs) are obligatory. They can be also allocated + * locally. Anyway, if you use an already-cached attribute object, you shall + * call rta_clone() on that object yourself. (This semantics may change in future.) + * + * If the route attributes are local, you may set @rte->attrs->src to NULL, then + * the protocol's default route source will be supplied. + * + * When rte_update() gets a route, it automatically validates it. This includes + * checking for validity of the given network and next hop addresses and also + * checking for host-scope or link-scope routes. Then the import filters are + * processed and if accepted, the route is passed to route table recalculation. + * + * The accepted routes are then inserted into the table, replacing the old route + * for the same @net identified by @src. Then the route is announced + * to all the channels connected to the table using the standard export mechanism. + * Setting @rte to NULL makes this a withdraw, otherwise @rte->src must be the same + * as @src. + * + * All memory used for temporary allocations is taken from a special linpool + * @rte_update_pool and freed when rte_update() finishes. + */ +void rte_update(struct channel *c, const net_addr *net, struct rte *rte, struct rte_src *src); + +extern list routing_tables; +struct config; + +void rt_init(void); +void rt_preconfig(struct config *); +void rt_postconfig(struct config *); +void rt_commit(struct config *new, struct config *old); +void rt_lock_table(rtable *); +void rt_unlock_table(rtable *); +struct f_trie * rt_lock_trie(rtable *tab); +void rt_unlock_trie(rtable *tab, struct f_trie *trie); +void rt_subscribe(rtable *tab, struct rt_subscription *s); +void rt_unsubscribe(struct rt_subscription *s); +void rt_flowspec_link(rtable *src, rtable *dst); +void rt_flowspec_unlink(rtable *src, rtable *dst); +rtable *rt_setup(pool *, struct rtable_config *); +static inline void rt_shutdown(rtable *r) { rfree(r->rp); } + +static inline net *net_find(rtable *tab, const net_addr *addr) { return (net *) fib_find(&tab->fib, addr); } +static inline net *net_find_valid(rtable *tab, const net_addr *addr) +{ net *n = net_find(tab, addr); return (n && n->routes && rte_is_valid(&n->routes->rte)) ? n : NULL; } +static inline net *net_get(rtable *tab, const net_addr *addr) { return (net *) fib_get(&tab->fib, addr); } +net *net_get(rtable *tab, const net_addr *addr); +net *net_route(rtable *tab, const net_addr *n); +int rt_examine(rtable *t, net_addr *a, struct channel *c, const struct filter *filter); +rte *rt_export_merged(struct channel *c, rte ** feed, uint count, linpool *pool, int silent); +void rt_refresh_begin(struct rt_import_request *); +void rt_refresh_end(struct rt_import_request *); +void rt_modify_stale(rtable *t, struct rt_import_request *); +void rt_schedule_prune(rtable *t); +void rte_dump(struct rte_storage *); +void rte_free(struct rte_storage *); +struct rte_storage *rte_store(const rte *, net *net, rtable *); +void rt_dump(rtable *); +void rt_dump_all(void); +void rt_dump_hooks(rtable *); +void rt_dump_hooks_all(void); +int rt_reload_channel(struct channel *c); +void rt_reload_channel_abort(struct channel *c); +void rt_refeed_channel(struct channel *c); +void rt_prune_sync(rtable *t, int all); +struct rtable_config *rt_new_table(struct symbol *s, uint addr_type); + +static inline int rt_is_ip(rtable *tab) +{ return (tab->addr_type == NET_IP4) || (tab->addr_type == NET_IP6); } + +static inline int rt_is_vpn(rtable *tab) +{ return (tab->addr_type == NET_VPN4) || (tab->addr_type == NET_VPN6); } + +static inline int rt_is_roa(rtable *tab) +{ return (tab->addr_type == NET_ROA4) || (tab->addr_type == NET_ROA6); } + +static inline int rt_is_flow(rtable *tab) +{ return (tab->addr_type == NET_FLOW4) || (tab->addr_type == NET_FLOW6); } + + +/* Default limit for ECMP next hops, defined in sysdep code */ +extern const int rt_default_ecmp; + +struct rt_show_data_rtable { + node n; + const char *name; + struct rt_exporter *table; + struct channel *export_channel; + struct channel *prefilter; + struct krt_proto *kernel; +}; + +struct rt_show_data { + struct cli *cli; /* Pointer back to the CLI */ + net_addr *addr; + list tables; + struct rt_show_data_rtable *tab; /* Iterator over table list */ + struct rt_show_data_rtable *last_table; /* Last table in output */ + struct rt_export_request req; /* Export request in use */ + int verbose, tables_defined_by; + const struct filter *filter; + struct proto *show_protocol; + struct proto *export_protocol; + struct channel *export_channel; + struct config *running_on_config; + struct rt_export_hook *kernel_export_hook; + int export_mode, addr_mode, primary_only, filtered, stats; + + int net_counter, rt_counter, show_counter, table_counter; + int net_counter_last, rt_counter_last, show_counter_last; + int show_counter_last_flush; +}; + +void rt_show(struct rt_show_data *); +struct rt_show_data_rtable * rt_show_add_exporter(struct rt_show_data *d, struct rt_exporter *t, const char *name); +struct rt_show_data_rtable * rt_show_add_table(struct rt_show_data *d, struct rtable *t); + +/* Value of table definition mode in struct rt_show_data */ +#define RSD_TDB_DEFAULT 0 /* no table specified */ +#define RSD_TDB_INDIRECT 0 /* show route ... protocol P ... */ +#define RSD_TDB_ALL RSD_TDB_SET /* show route ... table all ... */ +#define RSD_TDB_DIRECT RSD_TDB_SET | RSD_TDB_NMN /* show route ... table X table Y ... */ + +#define RSD_TDB_SET 0x1 /* internal: show empty tables */ +#define RSD_TDB_NMN 0x2 /* internal: need matching net */ + +/* Value of export_mode in struct rt_show_data */ +#define RSEM_NONE 0 /* Export mode not used */ +#define RSEM_PREEXPORT 1 /* Routes ready for export, before filtering */ +#define RSEM_EXPORT 2 /* Routes accepted by export filter */ +#define RSEM_NOEXPORT 3 /* Routes rejected by export filter */ +#define RSEM_EXPORTED 4 /* Routes marked in export map */ + +/* Host entry: Resolve hook for recursive nexthops */ +extern struct ea_class ea_gen_hostentry; +struct hostentry_adata { + adata ad; + struct hostentry *he; + u32 labels[0]; +}; + +void +ea_set_hostentry(ea_list **to, struct rtable *dep, struct rtable *tab, ip_addr gw, ip_addr ll, u32 lnum, u32 labels[lnum]); + +void ea_show_hostentry(const struct adata *ad, byte *buf, uint size); +void ea_show_nexthop_list(struct cli *c, struct nexthop_adata *nhad); + +/* + * Default protocol preferences + */ + +#define DEF_PREF_DIRECT 240 /* Directly connected */ +#define DEF_PREF_STATIC 200 /* Static route */ +#define DEF_PREF_OSPF 150 /* OSPF intra-area, inter-area and type 1 external routes */ +#define DEF_PREF_BABEL 130 /* Babel */ +#define DEF_PREF_RIP 120 /* RIP */ +#define DEF_PREF_BGP 100 /* BGP */ +#define DEF_PREF_RPKI 100 /* RPKI */ +#define DEF_PREF_INHERITED 10 /* Routes inherited from other routing daemons */ +#define DEF_PREF_UNKNOWN 0 /* Routes with no preference set */ + +/* + * Route Origin Authorization + */ + +#define ROA_UNKNOWN 0 +#define ROA_VALID 1 +#define ROA_INVALID 2 + +int net_roa_check(rtable *tab, const net_addr *n, u32 asn); + +#endif |