/* * BIRD Internet Routing Daemon -- Routing data structures * * (c) 1998--2000 Martin Mares * (c) 2022 Maria Matejka * * Can be freely distributed and used under the terms of the GNU GPL. */ #ifndef _BIRD_LIB_ROUTE_H_ #define _BIRD_LIB_ROUTE_H_ #include "lib/type.h" struct network; struct proto; struct cli; typedef struct rte { struct rte *next; struct network *net; /* Network this RTE belongs to */ struct rte_src *src; /* Route source that created the route */ struct channel *sender; /* Channel used to send the route to the routing table */ struct rta *attrs; /* Attributes of this route */ u32 id; /* Table specific route id */ byte flags; /* Flags (REF_...) */ byte pflags; /* Protocol-specific flags */ btime lastmod; /* Last modified */ } 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 */ #define REF_MODIFY 16 /* Route is scheduled for modify */ /* 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); } 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 */ }; 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); /* * 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 flags; byte weight; byte labels; /* Number of all labels */ u32 label[0]; }; #define RNF_ONLINK 0x1 /* Gateway is onlink regardless of IP ranges */ 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 hostentry *hostentry; /* Hostentry for recursive next-hops */ u16 cached:1; /* Are attributes cached? */ u16 dest:4; /* Route destination type (RTD_...) */ struct nexthop nh; /* Next hop */ } rta; #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 RTS_PERF 15 /* Perf checker */ #define RTS_MAX 16 #define RTD_NONE 0 /* Undefined next hop */ #define RTD_UNICAST 1 /* 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_MAX 5 extern const char * rta_dest_names[RTD_MAX]; static inline const char *rta_dest_name(uint n) { return (n < RTD_MAX) ? rta_dest_names[n] : "???"; } /* Route has regular, reachable nexthop (i.e. not RTD_UNREACHABLE and like) */ static inline int rte_is_reachable(rte *r) { return r->attrs->dest == RTD_UNICAST; } /* * Extended Route Attributes */ typedef struct eattr { word id; /* EA_CODE(PROTOCOL_..., protocol-dependent ID) */ byte flags; /* Protocol-dependent flags */ byte type; /* Attribute type */ byte rfu:5; byte originated:1; /* The attribute has originated locally */ byte fresh:1; /* An uncached attribute (e.g. modified in export filter) */ byte undef:1; /* Explicitly undefined */ PADDING(unused, 3, 3); union bval u; } eattr; #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 EA_BIT_GET(ea) ((ea) >> 24) 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 ea_class { #define EA_CLASS_INSIDE \ const char *name; /* Name (both print and filter) */ \ struct symbol *sym; /* Symbol to export to configs */ \ uint id; /* Autoassigned attribute ID */ \ uint uc; /* Reference count */ \ btype type; /* Data type ID */ \ uint readonly:1; /* This attribute can't be changed by filters */ \ uint conf:1; /* Requested by config */ \ void (*format)(const eattr *ea, byte *buf, uint size); \ EA_CLASS_INSIDE; }; struct ea_class_ref { resource r; struct ea_class *class; }; void ea_register_init(struct ea_class *); struct ea_class_ref *ea_register_alloc(pool *, struct ea_class); #define EA_REGISTER_ALL_HELPER(x) ea_register_init(x); #define EA_REGISTER_ALL(...) MACRO_FOREACH(EA_REGISTER_ALL_HELPER, __VA_ARGS__) struct ea_class *ea_class_find_by_id(uint id); struct ea_class *ea_class_find_by_name(const char *name); static inline struct ea_class *ea_class_self(struct ea_class *self) { return self; } #define ea_class_find(_arg) _Generic((_arg), \ uint: ea_class_find_by_id, \ word: ea_class_find_by_id, \ char *: ea_class_find_by_name, \ const char *: ea_class_find_by_name, \ struct ea_class *: ea_class_self)(_arg) 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 */ }; #define ea_find(_l, _arg) _Generic((_arg), uint: ea_find_by_id, struct ea_class *: ea_find_by_class, char *: ea_find_by_name)(_l, _arg) eattr *ea_find_by_id(ea_list *, unsigned ea); static inline eattr *ea_find_by_class(ea_list *l, const struct ea_class *def) { return ea_find_by_id(l, def->id); } static inline eattr *ea_find_by_name(ea_list *l, const char *name) { const struct ea_class *def = ea_class_find_by_name(name); return def ? ea_find_by_class(l, def) : NULL; } #define ea_get_int(_l, _ident, _def) ({ \ struct ea_class *cls = ea_class_find((_ident)); \ ASSERT_DIE(cls->type & EAF_EMBEDDED); \ const eattr *ea = ea_find((_l), cls->id); \ (ea ? ea->u.data : (_def)); \ }) #define ea_get_ip(_l, _ident, _def) ({ \ struct ea_class *cls = ea_class_find((_ident)); \ ASSERT_DIE(cls->type == T_IP); \ const eattr *ea = ea_find((_l), cls->id); \ (ea ? *((const ip_addr *) ea->u.ptr->data) : (_def)); \ }) eattr *ea_walk(struct ea_walk_state *s, uint id, uint max); void ea_dump(ea_list *); 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(const struct eattr *a, byte *buf, int bufsize, const char **names, int min, int max); /* Normalize ea_list; allocates the result from tmp_linpool */ ea_list *ea_normalize(const ea_list *e); uint ea_list_size(ea_list *); void ea_list_copy(ea_list *dest, ea_list *src, uint size); #define EA_LOCAL_LIST(N) struct { ea_list l; eattr a[N]; } #define EA_LITERAL_EMBEDDED(_class, _flags, _val) ({ \ btype _type = (_class)->type; \ ASSERT_DIE(_type & EAF_EMBEDDED); \ EA_LITERAL_GENERIC((_class)->id, _type, _flags, .u.i = _val); \ }) #define EA_LITERAL_STORE_ADATA(_class, _flags, _buf, _len) ({ \ btype _type = (_class)->type; \ ASSERT_DIE(!(_type & EAF_EMBEDDED)); \ EA_LITERAL_GENERIC((_class)->id, _type, _flags, .u.ad = tmp_store_adata((_buf), (_len))); \ }) #define EA_LITERAL_DIRECT_ADATA(_class, _flags, _adata) ({ \ btype _type = (_class)->type; \ ASSERT_DIE(!(_type & EAF_EMBEDDED)); \ EA_LITERAL_GENERIC((_class)->id, _type, _flags, .u.ad = _adata); \ }) #define EA_LITERAL_GENERIC(_id, _type, _flags, ...) \ ((eattr) { .id = _id, .type = _type, .flags = _flags, __VA_ARGS__ }) static inline eattr * ea_set_attr(ea_list **to, eattr a) { EA_LOCAL_LIST(1) *ea = tmp_alloc(sizeof(*ea)); *ea = (typeof(*ea)) { .l.flags = EALF_SORTED, .l.count = 1, .l.next = *to, .a[0] = a, }; *to = &ea->l; return &ea->a[0]; } static inline void ea_unset_attr(ea_list **to, _Bool local, const struct ea_class *def) { ea_set_attr(to, EA_LITERAL_GENERIC(def->id, 0, 0, .fresh = local, .originated = local, .undef = 1)); } static inline void ea_set_attr_u32(ea_list **to, const struct ea_class *def, uint flags, u64 data) { ea_set_attr(to, EA_LITERAL_EMBEDDED(def, flags, data)); } static inline void ea_set_attr_data(ea_list **to, const struct ea_class *def, uint flags, void *data, uint len) { ea_set_attr(to, EA_LITERAL_STORE_ADATA(def, flags, data, len)); } /* * Common route attributes */ /* Preference: first-order comparison */ extern struct ea_class ea_gen_preference; static inline u32 rt_get_preference(rte *rt) { return ea_get_int(rt->attrs->eattrs, &ea_gen_preference, 0); } /* IGP metric: second-order comparison */ extern struct ea_class ea_gen_igp_metric; u32 rt_get_igp_metric(rte *rt); #define IGP_METRIC_UNKNOWN 0x80000000 /* Default igp_metric used when no other protocol-specific metric is availabe */ /* From: Advertising router */ extern struct ea_class ea_gen_from; /* Source: An old method to devise the route source protocol and kind. * To be superseded in a near future by something more informative. */ extern struct ea_class ea_gen_source; static inline u32 rt_get_source_attr(rte *rt) { return ea_get_int(rt->attrs->eattrs, &ea_gen_source, 0); } /* MPLS labels: Use with a recursive nexthop specification * to add additional labels to the resolved nexthop */ extern struct ea_class ea_mpls_labels; /* Next hop structures */ #define NEXTHOP_MAX_SIZE (sizeof(struct nexthop) + sizeof(u32)*MPLS_MAX_LABEL_STACK) static inline size_t nexthop_size(const struct nexthop *nh) { return sizeof(struct nexthop) + sizeof(u32)*nh->labels; } 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); struct nexthop *nexthop_sort(struct nexthop *x); static inline void nexthop_link(struct rta *a, struct nexthop *from) { memcpy(&a->nh, from, nexthop_size(from)); } void nexthop_insert(struct nexthop **n, struct nexthop *y); int nexthop_is_sorted(struct nexthop *x); void rta_init(void); static inline size_t rta_size(const rta *a) { return sizeof(rta) + sizeof(u32)*a->nh.labels; } #define RTA_MAX_SIZE (sizeof(rta) + sizeof(u32)*MPLS_MAX_LABEL_STACK) rta *rta_lookup(rta *); /* Get rta equivalent to this one, uc++ */ static inline int rta_is_cached(rta *r) { return r->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 *); #endif