/* * BIRD Internet Routing Daemon -- Routing Table * * (c) 1998--2000 Martin Mares * * Can be freely distributed and used under the terms of the GNU GPL. */ #ifndef _BIRD_ROUTE_H_ #define _BIRD_ROUTE_H_ #include "lib/lists.h" #include "lib/resource.h" #include "sysdep/unix/timer.h" #include "lib/net.h" struct ea_list; struct protocol; struct proto; struct rte_src; struct symbol; struct filter; struct cli; /* * Generic data structure for storing network prefixes. Also used * for the master routing table. Currently implemented as a hash * table. * * Available operations: * - insertion of new entry * - deletion of entry * - searching for entry by network prefix * - asynchronous retrieval of fib contents */ struct fib_node { struct fib_node *next; /* Next in hash chain */ struct fib_iterator *readers; /* List of readers of this node */ byte flags; /* User-defined, will be removed */ net_addr addr[0]; }; struct fib_iterator { /* See lib/slists.h for an explanation */ struct fib_iterator *prev, *next; /* Must be synced with struct fib_node! */ byte efef; /* 0xff to distinguish between iterator and node */ byte pad[3]; struct fib_node *node; /* Or NULL if freshly merged */ uint hash; }; typedef void (*fib_init_fn)(void *); struct fib { pool *fib_pool; /* Pool holding all our data */ slab *fib_slab; /* Slab holding all fib nodes */ struct fib_node **hash_table; /* Node hash table */ uint hash_size; /* Number of hash table entries (a power of two) */ uint hash_order; /* Binary logarithm of hash_size */ uint hash_shift; /* 32 - hash_order */ uint addr_type; /* Type of address data stored in fib (NET_*) */ uint node_size; /* FIB node size, 0 for nonuniform */ uint node_offset; /* Offset of fib_node struct inside of user data */ uint entries; /* Number of entries */ uint entries_min, entries_max; /* Entry count limits (else start rehashing) */ fib_init_fn init; /* Constructor */ }; static inline void * fib_node_to_user(struct fib *f, struct fib_node *e) { return e ? (void *) ((char *) e - f->node_offset) : NULL; } static inline struct fib_node * fib_user_to_node(struct fib *f, void *e) { return e ? (void *) ((char *) e + f->node_offset) : NULL; } void fib_init(struct fib *f, pool *p, uint addr_type, uint node_size, uint node_offset, uint hash_order, fib_init_fn init); void *fib_find(struct fib *, const net_addr *); /* Find or return NULL if doesn't exist */ void *fib_get_chain(struct fib *f, const net_addr *a); /* Find first node in linked list from hash table */ void *fib_get(struct fib *, const net_addr *); /* Find or create new if nonexistent */ void *fib_route(struct fib *, const net_addr *); /* Longest-match routing lookup */ void fib_delete(struct fib *, void *); /* Remove fib entry */ void fib_free(struct fib *); /* Destroy the fib */ void fib_check(struct fib *); /* Consistency check for debugging */ void fit_init(struct fib_iterator *, struct fib *); /* Internal functions, don't call */ struct fib_node *fit_get(struct fib *, struct fib_iterator *); void fit_put(struct fib_iterator *, struct fib_node *); void fit_put_next(struct fib *f, struct fib_iterator *i, struct fib_node *n, uint hpos); #define FIB_WALK(fib, type, z) do { \ struct fib_node *fn_, **ff_ = (fib)->hash_table; \ uint count_ = (fib)->hash_size; \ type *z; \ while (count_--) \ for (fn_ = *ff_++; z = fib_node_to_user(fib, fn_); fn_=fn_->next) #define FIB_WALK_END } while (0) #define FIB_ITERATE_INIT(it, fib) fit_init(it, fib) #define FIB_ITERATE_START(fib, it, type, z) do { \ struct fib_node *fn_ = fit_get(fib, it); \ uint count_ = (fib)->hash_size; \ uint hpos_ = (it)->hash; \ type *z; \ for(;;) { \ if (!fn_) \ { \ if (++hpos_ >= count_) \ break; \ fn_ = (fib)->hash_table[hpos_]; \ continue; \ } \ z = fib_node_to_user(fib, fn_); #define FIB_ITERATE_END fn_ = fn_->next; } } while(0) #define FIB_ITERATE_PUT(it) fit_put(it, fn_) #define FIB_ITERATE_PUT_NEXT(it, fib) fit_put_next(fib, it, fn_, hpos_) #define FIB_ITERATE_UNLINK(it, fib) fit_get(fib, it) /* * 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_*) */ int gc_max_ops; /* Maximum number of operations before GC is run */ int gc_min_time; /* Minimum time between two consecutive GC runs */ byte sorted; /* Routes of network are sorted according to rte_better() */ }; typedef struct rtable { node n; /* Node in list of all tables */ struct fib fib; char *name; /* Name of this table */ list channels; /* List of attached channels (struct channel) */ uint addr_type; /* Type of address data stored in table (NET_*) */ int pipe_busy; /* Pipe loop detection */ int use_count; /* Number of protocols using this table */ 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 */ int gc_counter; /* Number of operations since last GC */ bird_clock_t gc_time; /* Time of last GC */ byte prune_state; /* Table prune state, 1 -> scheduled, 2-> running */ byte hcu_scheduled; /* Hostcache update is scheduled */ byte nhu_state; /* Next Hop Update state */ struct fib_iterator prune_fit; /* Rtable prune FIB iterator */ struct fib_iterator nhu_fit; /* Next Hop Update FIB iterator */ } rtable; typedef struct network { struct rte *routes; /* Available routes for this network */ 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 */ struct rta *src; /* Source rta entry */ struct nexthop *nh; /* Chosen next hop */ byte dest; /* Chosen route destination type (RTD_...) */ u32 igp_metric; /* Chosen route IGP metric */ }; typedef struct rte { struct rte *next; net *net; /* Network this RTE belongs to */ struct channel *sender; /* Channel used to send the route to the routing table */ struct rta *attrs; /* Attributes of this route */ byte flags; /* Flags (REF_...) */ byte pflags; /* Protocol-specific flags */ word pref; /* Route preference */ bird_clock_t lastmod; /* Last modified */ union { /* Protocol-dependent data (metrics etc.) */ #ifdef CONFIG_RIP struct { struct iface *from; /* Incoming iface */ u8 metric; /* RIP metric */ u16 tag; /* External route tag */ } rip; #endif #ifdef CONFIG_OSPF struct { u32 metric1, metric2; /* OSPF Type 1 and Type 2 metrics */ u32 tag; /* External route tag */ u32 router_id; /* Router that originated this route */ } ospf; #endif #ifdef CONFIG_BGP struct { u8 suppressed; /* Used for deterministic MED comparison */ } bgp; #endif #ifdef CONFIG_BABEL struct { u16 metric; /* Babel metric */ u64 router_id; /* Babel router id */ } babel; #endif struct { /* Routes generated by krt sync (both temporary and inherited ones) */ s8 src; /* Alleged route source (see krt.h) */ u8 proto; /* Kernel source protocol ID */ u8 seen; /* Seen during last scan */ u8 best; /* Best route in network, propagated to core */ u32 metric; /* Kernel metric */ } krt; } u; } rte; #define REF_COW 1 /* Copy this rte on write */ #define REF_FILTERED 2 /* Route is rejected by import filter */ #define REF_STALE 4 /* Route is stale in a refresh cycle */ #define REF_DISCARD 8 /* Route is scheduled for discard */ /* Route is valid for propagation (may depend on other flags in the future), accepts NULL */ static inline int rte_is_valid(rte *r) { return r && !(r->flags & REF_FILTERED); } /* Route just has REF_FILTERED flag */ static inline int rte_is_filtered(rte *r) { return !!(r->flags & REF_FILTERED); } /* Types of route announcement, also used as flags */ #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 import_control() 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 */ struct config; void rt_init(void); void rt_preconfig(struct config *); void rt_commit(struct config *new, struct config *old); void rt_lock_table(rtable *); void rt_unlock_table(rtable *); void rt_setup(pool *, rtable *, char *, struct rtable_config *); static inline net *net_find(rtable *tab, const net_addr *addr) { return (net *) fib_find(&tab->fib, addr); } static inline net *net_get(rtable *tab, const net_addr *addr) { return (net *) fib_get(&tab->fib, addr); } void *net_route(rtable *tab, const net_addr *n); int net_roa_check(rtable *tab, const net_addr *n, u32 asn); rte *rte_find(net *net, struct rte_src *src); rte *rte_get_temp(struct rta *); void rte_update2(struct channel *c, const net_addr *n, rte *new, struct rte_src *src); /* rte_update() moved to protocol.h to avoid dependency conflicts */ int rt_examine(rtable *t, net_addr *a, struct proto *p, struct filter *filter); rte *rt_export_merged(struct channel *c, net *net, rte **rt_free, struct ea_list **tmpa, linpool *pool, int silent); void rt_refresh_begin(rtable *t, struct channel *c); void rt_refresh_end(rtable *t, struct channel *c); void rt_schedule_prune(rtable *t); void rte_dump(rte *); void rte_free(rte *); rte *rte_do_cow(rte *); static inline rte * rte_cow(rte *r) { return (r->flags & REF_COW) ? rte_do_cow(r) : r; } rte *rte_cow_rta(rte *r, linpool *lp); void rt_dump(rtable *); void rt_dump_all(void); int rt_feed_channel(struct channel *c); void rt_feed_channel_abort(struct channel *c); struct rtable_config *rt_new_table(struct symbol *s, uint addr_type); struct rt_show_data { net_addr *addr; rtable *table; struct filter *filter; int verbose; struct fib_iterator fit; struct proto *show_protocol; struct proto *export_protocol; struct channel *export_channel; int export_mode, primary_only, filtered; struct config *running_on_config; int net_counter, rt_counter, show_counter; int stats, show_for; }; void rt_show(struct rt_show_data *); /* 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 */ /* * Route Attributes * * Beware: All standard BGP attributes must be represented here instead * of making them local to the route. This is needed to ensure proper * construction of BGP route attribute lists. */ /* Nexthop structure */ struct nexthop { ip_addr gw; /* Next hop */ struct iface *iface; /* Outgoing interface */ struct nexthop *next; byte weight; }; struct rte_src { struct rte_src *next; /* Hash chain */ struct proto *proto; /* Protocol the source is based on */ u32 private_id; /* Private ID, assigned by the protocol */ u32 global_id; /* Globally unique ID of the source */ unsigned uc; /* Use count */ }; typedef struct rta { struct rta *next, **pprev; /* Hash chain */ u32 uc; /* Use count */ u32 hash_key; /* Hash over important fields */ struct ea_list *eattrs; /* Extended Attribute chain */ struct rte_src *src; /* Route source that created the route */ struct hostentry *hostentry; /* Hostentry for recursive next-hops */ ip_addr from; /* Advertising router */ u32 igp_metric; /* IGP metric to next hop (for iBGP routes) */ u32 bf[0]; u32 source:6; /* Route source (RTS_...) */ u32 scope:6; /* Route scope (SCOPE_... -- see ip.h) */ u32 cast:6; /* Casting type (RTC_...) */ u32 dest:6; /* Route destination type (RTD_...) */ // u32 eflags:8; /* Flags (RTAF_...) */ u32 aflags:8; struct nexthop nh; /* Next hop */ } rta; #define RTS_DUMMY 0 /* Dummy route to be removed soon */ #define RTS_STATIC 1 /* Normal static route */ #define RTS_INHERIT 2 /* Route inherited from kernel */ #define RTS_DEVICE 3 /* Device route */ #define RTS_STATIC_DEVICE 4 /* Static device route */ #define RTS_REDIRECT 5 /* Learned via redirect */ #define RTS_RIP 6 /* RIP route */ #define RTS_OSPF 7 /* OSPF route */ #define RTS_OSPF_IA 8 /* OSPF inter-area route */ #define RTS_OSPF_EXT1 9 /* OSPF external route type 1 */ #define RTS_OSPF_EXT2 10 /* OSPF external route type 2 */ #define RTS_BGP 11 /* BGP route */ #define RTS_PIPE 12 /* Inter-table wormhole */ #define RTS_BABEL 13 /* Babel route */ #define RTS_RPKI 14 /* Route Origin Authorization */ #define RTC_UNICAST 0 #define RTC_BROADCAST 1 #define RTC_MULTICAST 2 #define RTC_ANYCAST 3 /* IPv6 Anycast */ #define RTD_UNICAST 0 /* Next hop is neighbor router */ #define RTD_BLACKHOLE 2 /* Silently drop packets */ #define RTD_UNREACHABLE 3 /* Reject as unreachable */ #define RTD_PROHIBIT 4 /* Administratively prohibited */ #define RTD_NONE 6 /* Invalid RTD */ /* Flags for net->n.flags, used by kernel syncer */ #define KRF_INSTALLED 0x80 /* This route should be installed in the kernel */ #define KRF_SYNC_ERROR 0x40 /* Error during kernel table synchronization */ #define RTAF_CACHED 1 /* This is a cached rta */ #define IGP_METRIC_UNKNOWN 0x80000000 /* Default igp_metric used when no other protocol-specific metric is availabe */ /* Route has regular, reachable nexthop (i.e. not RTD_UNREACHABLE and like) */ static inline int rte_is_reachable(rte *r) { uint d = r->attrs->dest; return (d == RTD_UNICAST); } /* * Extended Route Attributes */ typedef struct eattr { word id; /* EA_CODE(EAP_..., protocol-dependent ID) */ byte flags; /* Protocol-dependent flags */ byte type; /* Attribute type and several flags (EAF_...) */ union { u32 data; struct adata *ptr; /* Attribute data elsewhere */ } u; } eattr; #define EAP_GENERIC 0 /* Generic attributes */ #define EAP_BGP 1 /* BGP attributes */ #define EAP_RIP 2 /* RIP */ #define EAP_OSPF 3 /* OSPF */ #define EAP_KRT 4 /* Kernel route attributes */ #define EAP_BABEL 5 /* Babel attributes */ #define EAP_MAX 6 #define EA_CODE(proto,id) (((proto) << 8) | (id)) #define EA_PROTO(ea) ((ea) >> 8) #define EA_ID(ea) ((ea) & 0xff) #define EA_GEN_IGP_METRIC EA_CODE(EAP_GENERIC, 0) #define EA_CODE_MASK 0xffff #define EA_ALLOW_UNDEF 0x10000 /* ea_find: allow EAF_TYPE_UNDEF */ #define EA_BIT(n) ((n) << 24) /* Used in bitfield accessors */ #define EAF_TYPE_MASK 0x1f /* Mask with this to get type */ #define EAF_TYPE_INT 0x01 /* 32-bit unsigned integer number */ #define EAF_TYPE_OPAQUE 0x02 /* Opaque byte string (not filterable) */ #define EAF_TYPE_IP_ADDRESS 0x04 /* IP address */ #define EAF_TYPE_ROUTER_ID 0x05 /* Router ID (IPv4 address) */ #define EAF_TYPE_AS_PATH 0x06 /* BGP AS path (encoding per RFC 1771:4.3) */ #define EAF_TYPE_BITFIELD 0x09 /* 32-bit embedded bitfield */ #define EAF_TYPE_INT_SET 0x0a /* Set of u32's (e.g., a community list) */ #define EAF_TYPE_EC_SET 0x0e /* Set of pairs of u32's - ext. community list */ #define EAF_TYPE_LC_SET 0x12 /* Set of triplets of u32's - large community list */ #define EAF_TYPE_UNDEF 0x1f /* `force undefined' entry */ #define EAF_EMBEDDED 0x01 /* Data stored in eattr.u.data (part of type spec) */ #define EAF_VAR_LENGTH 0x02 /* Attribute length is variable (part of type spec) */ #define EAF_ORIGINATED 0x20 /* The attribute has originated locally */ #define EAF_FRESH 0x40 /* An uncached attribute (e.g. modified in export filter) */ #define EAF_TEMP 0x80 /* A temporary attribute (the one stored in the tmp attr list) */ typedef struct adata { uint length; /* Length of data */ byte data[0]; } adata; static inline struct adata * lp_alloc_adata(struct linpool *pool, uint len) { struct adata *ad = lp_alloc(pool, sizeof(struct adata) + len); ad->length = len; return ad; } static inline int adata_same(struct adata *a, struct adata *b) { return (a->length == b->length && !memcmp(a->data, b->data, a->length)); } typedef struct ea_list { struct ea_list *next; /* In case we have an override list */ byte flags; /* Flags: EALF_... */ byte rfu; word count; /* Number of attributes */ eattr attrs[0]; /* Attribute definitions themselves */ } ea_list; #define EALF_SORTED 1 /* Attributes are sorted by code */ #define EALF_BISECT 2 /* Use interval bisection for searching */ #define EALF_CACHED 4 /* Attributes belonging to cached rta */ struct rte_src *rt_find_source(struct proto *p, u32 id); struct rte_src *rt_get_source(struct proto *p, u32 id); static inline void rt_lock_source(struct rte_src *src) { src->uc++; } static inline void rt_unlock_source(struct rte_src *src) { src->uc--; } void rt_prune_sources(void); struct ea_walk_state { ea_list *eattrs; /* Ccurrent ea_list, initially set by caller */ eattr *ea; /* Current eattr, initially NULL */ u32 visited[4]; /* Bitfield, limiting max to 128 */ }; eattr *ea_find(ea_list *, unsigned ea); eattr *ea_walk(struct ea_walk_state *s, uint id, uint max); int ea_get_int(ea_list *, unsigned ea, int def); void ea_dump(ea_list *); void ea_sort(ea_list *); /* Sort entries in all sub-lists */ unsigned ea_scan(ea_list *); /* How many bytes do we need for merged ea_list */ void ea_merge(ea_list *from, ea_list *to); /* Merge sub-lists to allocated buffer */ int ea_same(ea_list *x, ea_list *y); /* Test whether two ea_lists are identical */ uint ea_hash(ea_list *e); /* Calculate 16-bit hash value */ ea_list *ea_append(ea_list *to, ea_list *what); void ea_format_bitfield(struct eattr *a, byte *buf, int bufsize, const char **names, int min, int max); int nexthop__same(struct nexthop *x, struct nexthop *y); /* Compare multipath nexthops */ static inline int nexthop_same(struct nexthop *x, struct nexthop *y) { return (x == y) || nexthop__same(x, y); } struct nexthop *nexthop_merge(struct nexthop *x, struct nexthop *y, int rx, int ry, int max, linpool *lp); static inline void nexthop_link(struct rta *a, struct nexthop *from) { a->nh.gw = from->gw; a->nh.iface = from->iface; a->nh.weight = from->weight; a->nh.next = from->next; } void nexthop_insert(struct nexthop *n, struct nexthop *y); int nexthop_is_sorted(struct nexthop *x); void rta_init(void); rta *rta_lookup(rta *); /* Get rta equivalent to this one, uc++ */ static inline int rta_is_cached(rta *r) { return r->aflags & RTAF_CACHED; } static inline rta *rta_clone(rta *r) { r->uc++; return r; } void rta__free(rta *r); static inline void rta_free(rta *r) { if (r && !--r->uc) rta__free(r); } rta *rta_do_cow(rta *o, linpool *lp); static inline rta * rta_cow(rta *r, linpool *lp) { return rta_is_cached(r) ? rta_do_cow(r, lp) : r; } void rta_dump(rta *); void rta_dump_all(void); void rta_show(struct cli *, rta *, ea_list *); void rta_set_recursive_next_hop(rtable *dep, rta *a, rtable *tab, ip_addr gw, ip_addr ll); /* * rta_set_recursive_next_hop() acquires hostentry from hostcache and fills * rta->hostentry field. New hostentry has zero use count. Cached rta locks its * hostentry (increases its use count), uncached rta does not lock it. Hostentry * with zero use count is removed asynchronously during host cache update, * therefore it is safe to hold such hostentry temorarily. Hostentry holds a * lock for a 'source' rta, mainly to share multipath nexthops. * * There is no need to hold a lock for hostentry->dep table, because that table * contains routes responsible for that hostentry, and therefore is non-empty if * given hostentry has non-zero use count. If the hostentry has zero use count, * the entry is removed before dep is referenced. * * The protocol responsible for routes with recursive next hops should hold a * lock for a 'source' table governing that routes (argument tab to * rta_set_recursive_next_hop()), because its routes reference hostentries * (through rta) related to the governing table. When all such routes are * removed, rtas are immediately removed achieving zero uc. Then the 'source' * table lock could be immediately released, although hostentries may still * exist - they will be freed together with the 'source' table. */ static inline void rt_lock_hostentry(struct hostentry *he) { if (he) he->uc++; } static inline void rt_unlock_hostentry(struct hostentry *he) { if (he) he->uc--; } extern struct protocol *attr_class_to_protocol[EAP_MAX]; /* * 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 */ /* * Route Origin Authorization */ #define ROA_UNKNOWN 0 #define ROA_VALID 1 #define ROA_INVALID 2 #endif