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bird/lib/route.h
2024-06-26 17:19:24 +02:00

611 lines
19 KiB
C

/*
* BIRD Internet Routing Daemon -- Routing data structures
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
* (c) 2022 Maria Matejka <mq@jmq.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#ifndef _BIRD_LIB_ROUTE_H_
#define _BIRD_LIB_ROUTE_H_
#undef RT_SOURCE_DEBUG
#include "lib/type.h"
#include "lib/rcu.h"
#include "lib/hash.h"
#include "lib/event.h"
#include "lib/lockfree.h"
struct network;
struct proto;
struct cli;
struct rtable_private;
struct rte_storage;
#define RTE_IN_TABLE_WRITABLE \
byte pflags; /* Protocol-specific flags; may change in-table (!) */ \
byte flags; /* Table-specific flags */ \
u8 stale_cycle; /* Auxiliary value for route refresh; may change in-table (!) */ \
typedef struct rte {
RTE_IN_TABLE_WRITABLE;
u8 generation; /* If this route import is based on other previously exported route,
this value should be 1 + MAX(generation of the parent routes).
Otherwise the route is independent and this value is zero. */
u32 id; /* Table specific route id */
struct ea_list *attrs; /* Attributes of this route */
const net_addr *net; /* Network this RTE belongs to */
struct rte_src *src; /* Route source that created the route */
struct rt_import_hook *sender; /* Import hook used to send the route to the routing table */
btime lastmod; /* Last modified (set by table) */
} rte;
#define REF_FILTERED 2 /* Route is rejected by import filter */
#define REF_OBSOLETE 16 /* Route is obsolete, pending propagation */
#define REF_PENDING 32 /* Route has not propagated completely yet */
/* Route is valid for propagation (may depend on other flags in the future), accepts NULL */
static inline int rte_is_valid(const rte *r) { return r && !(r->flags & REF_FILTERED); }
/* Route just has REF_FILTERED flag */
static inline int rte_is_filtered(const rte *r) { return !!(r->flags & REF_FILTERED); }
/* Strip the route of the table-specific values */
static inline rte rte_init_from(const rte *r)
{
return (rte) {
.attrs = r->attrs,
.net = r->net,
.src = r->src,
};
}
int rte_same(const rte *, const rte *);
struct rte_src {
struct rte_src *next; /* Hash chain */
struct rte_owner *owner; /* Route source owner */
u64 private_id; /* Private ID, assigned by the protocol */
u32 global_id; /* Globally unique ID of the source */
struct lfuc uc; /* Use count */
};
struct rte_owner_class {
void (*get_route_info)(const rte *, byte *buf); /* Get route information (for `show route' command) */
int (*rte_better)(const rte *, const rte *);
int (*rte_mergable)(const rte *, const rte *);
u32 (*rte_igp_metric)(const rte *);
};
struct rte_owner {
struct rte_owner_class *class;
int (*rte_recalculate)(struct rtable_private *, struct network *, struct rte_storage *new, struct rte_storage *, struct rte_storage *);
HASH(struct rte_src) hash;
const char *name;
u32 hash_key;
u32 uc;
u32 debug;
event_list *list;
event *prune;
event *stop;
};
extern DOMAIN(attrs) attrs_domain;
#define RTA_LOCK LOCK_DOMAIN(attrs, attrs_domain)
#define RTA_UNLOCK UNLOCK_DOMAIN(attrs, attrs_domain)
#define RTE_SRC_PU_SHIFT 44
#define RTE_SRC_IN_PROGRESS (1ULL << RTE_SRC_PU_SHIFT)
/* Get a route source. This also locks the source, therefore the caller has to
* unlock the source after the route has been propagated. */
struct rte_src *rt_get_source_o(struct rte_owner *o, u32 id);
#define rt_get_source(p, id) rt_get_source_o(&(p)->sources, (id))
struct rte_src *rt_find_source_global(u32 id);
#ifdef RT_SOURCE_DEBUG
#define rt_lock_source _rt_lock_source_internal
#define rt_unlock_source _rt_unlock_source_internal
#endif
static inline void rt_lock_source(struct rte_src *src)
{
lfuc_lock(&src->uc);
}
static inline void rt_unlock_source(struct rte_src *src)
{
lfuc_unlock(&src->uc, src->owner->list, src->owner->prune);
}
#ifdef RT_SOURCE_DEBUG
#undef rt_lock_source
#undef rt_unlock_source
#define rt_lock_source(x) ( log(L_INFO "Lock source %uG at %s:%d", (x)->global_id, __FILE__, __LINE__), _rt_lock_source_internal(x) )
#define rt_unlock_source(x) ( log(L_INFO "Unlock source %uG at %s:%d", (x)->global_id, __FILE__, __LINE__), _rt_unlock_source_internal(x) )
#endif
void rt_init_sources(struct rte_owner *, const char *name, event_list *list);
void rt_destroy_sources(struct rte_owner *, event *);
void rt_dump_sources(struct rte_owner *);
/*
* 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 */
byte flags;
byte weight;
byte labels; /* Number of all labels */
u32 label[0];
};
/* For packing one into eattrs */
struct nexthop_adata {
struct adata ad;
/* There is either a set of nexthops or a special destination (RTD_*) */
union {
struct nexthop nh;
uint dest;
};
};
/* For MPLS label stack generation */
struct nexthop_adata_mpls {
struct nexthop_adata nhad;
u32 label_space[MPLS_MAX_LABEL_STACK];
};
#define NEXTHOP_DEST_SIZE (OFFSETOF(struct nexthop_adata, dest) + sizeof(uint) - OFFSETOF(struct adata, data))
#define NEXTHOP_DEST_LITERAL(x) ((struct nexthop_adata) { \
.ad.length = NEXTHOP_DEST_SIZE, .dest = (x), })
#define RNF_ONLINK 0x1 /* Gateway is onlink regardless of IP ranges */
#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_L3VPN 16 /* MPLS L3VPN */
#define RTS_AGGREGATED 17 /* Aggregated route */
#define RTS_MAX 18
#define RTD_NONE 0 /* Undefined next hop */
#define RTD_UNICAST 1 /* A standard next hop */
#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] : "???"; }
/*
* 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 stored:5; /* enum ea_stored */
byte rfu:3;
word count; /* Number of attributes */
eattr attrs[0]; /* Attribute definitions themselves */
} ea_list;
enum ea_stored {
EALS_NONE = 0, /* This is a temporary ea_list */
EALS_PREIMPORT = 1, /* State when route entered rte_update() */
EALS_FILTERED = 2, /* State after filters */
EALS_IN_TABLE = 3, /* State in table */
EALS_KEY = 4, /* EA list used as key */
EALS_CUSTOM = 0x10, /* OR this with custom values */
EALS_MAX = 0x20,
};
struct ea_storage {
struct ea_storage *next_hash; /* Next in hash chain */
_Atomic u64 uc; /* Use count */
u32 hash_key; /* List hash */
PADDING(unused, 0, 4); /* Sorry, we need u64 for the usecount */
ea_list l[0]; /* The list itself */
};
#define EALF_SORTED 1 /* Attributes are sorted by code */
#define EALF_BISECT 2 /* Use interval bisection for searching */
#define EALF_HUGE 8 /* List is too big to fit into slab */
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 */ \
u16 flags; /* Protocol-dependent flags */ \
uint readonly:1; /* This attribute can't be changed by filters */ \
uint conf:1; /* Requested by config */ \
uint hidden:1; /* Technical attribute, do not show, do not expose to filters */ \
void (*format)(const eattr *ea, byte *buf, uint size); \
void (*stored)(const eattr *ea); /* When stored into global hash */ \
void (*freed)(const eattr *ea); /* When released from global hash */ \
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);
struct ea_class_ref *ea_ref_class(pool *, struct ea_class *); /* Reference for an attribute alias */
#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)); \
})
#define ea_get_adata(_l, _ident) ({ \
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.ptr : &null_adata); \
})
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 attributes 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(ea_list *e, u32 upto);
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)
{
if (!a.id)
bug("You have forgotten to register your EA class");
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, const void *data, uint len)
{ ea_set_attr(to, EA_LITERAL_STORE_ADATA(def, flags, data, len)); }
static inline void
ea_copy_attr(ea_list **to, ea_list *from, const struct ea_class *def)
{
eattr *e = ea_find_by_class(from, def);
if (e)
if (e->type & EAF_EMBEDDED)
ea_set_attr_u32(to, def, e->flags, e->u.data);
else
ea_set_attr_data(to, def, e->flags, e->u.ptr->data, e->u.ptr->length);
else
ea_unset_attr(to, 0, def);
}
/*
* Common route attributes
*/
/* Preference: first-order comparison */
extern struct ea_class ea_gen_preference;
static inline u32 rt_get_preference(const rte *rt)
{ return ea_get_int(rt->attrs, &ea_gen_preference, 0); }
/* IGP metric: second-order comparison */
extern struct ea_class ea_gen_igp_metric;
u32 rt_get_igp_metric(const 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;
/* MPLS Label, Policy and Class */
extern struct ea_class ea_gen_mpls_label,
ea_gen_mpls_policy, ea_gen_mpls_class;
/* 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(const rte *rt)
{ return ea_get_int(rt->attrs, &ea_gen_source, 0); }
/* Flowspec validation result */
enum flowspec_valid {
FLOWSPEC_UNKNOWN = 0,
FLOWSPEC_VALID = 1,
FLOWSPEC_INVALID = 2,
FLOWSPEC__MAX,
};
extern const char * flowspec_valid_names[FLOWSPEC__MAX];
static inline const char *flowspec_valid_name(enum flowspec_valid v)
{ return (v < FLOWSPEC__MAX) ? flowspec_valid_names[v] : "???"; }
extern struct ea_class ea_gen_flowspec_valid;
static inline enum flowspec_valid rt_get_flowspec_valid(const rte *rt)
{ return ea_get_int(rt->attrs, &ea_gen_flowspec_valid, FLOWSPEC_UNKNOWN); }
/* Next hop: For now, stored as adata */
extern struct ea_class ea_gen_nexthop;
static inline void ea_set_dest(struct ea_list **to, uint flags, uint dest)
{
struct nexthop_adata nhad = NEXTHOP_DEST_LITERAL(dest);
ea_set_attr_data(to, &ea_gen_nexthop, flags, &nhad.ad.data, nhad.ad.length);
}
/* Next hop structures */
#define NEXTHOP_ALIGNMENT (_Alignof(struct nexthop))
#define NEXTHOP_MAX_SIZE (sizeof(struct nexthop) + sizeof(u32)*MPLS_MAX_LABEL_STACK)
#define NEXTHOP_SIZE(_nh) NEXTHOP_SIZE_CNT(((_nh)->labels))
#define NEXTHOP_SIZE_CNT(cnt) BIRD_ALIGN((sizeof(struct nexthop) + sizeof(u32) * (cnt)), NEXTHOP_ALIGNMENT)
#define nexthop_size(nh) NEXTHOP_SIZE((nh))
#define NEXTHOP_NEXT(_nh) ((void *) (_nh) + NEXTHOP_SIZE(_nh))
#define NEXTHOP_END(_nhad) ((_nhad)->ad.data + (_nhad)->ad.length)
#define NEXTHOP_VALID(_nh, _nhad) ((void *) (_nh) < (void *) NEXTHOP_END(_nhad))
#define NEXTHOP_ONE(_nhad) (NEXTHOP_NEXT(&(_nhad)->nh) == NEXTHOP_END(_nhad))
#define NEXTHOP_WALK(_iter, _nhad) for ( \
struct nexthop *_iter = &(_nhad)->nh; \
(void *) _iter < (void *) NEXTHOP_END(_nhad); \
_iter = NEXTHOP_NEXT(_iter))
static inline int nexthop_same(struct nexthop_adata *x, struct nexthop_adata *y)
{ return adata_same(&x->ad, &y->ad); }
struct nexthop_adata *nexthop_merge(struct nexthop_adata *x, struct nexthop_adata *y, int max, linpool *lp);
struct nexthop_adata *nexthop_sort(struct nexthop_adata *x, linpool *lp);
int nexthop_is_sorted(struct nexthop_adata *x);
#define NEXTHOP_IS_REACHABLE(nhad) ((nhad)->ad.length > NEXTHOP_DEST_SIZE)
static inline struct nexthop_adata *
rte_get_nexthops(rte *r)
{
eattr *nhea = ea_find(r->attrs, &ea_gen_nexthop);
return nhea ? SKIP_BACK(struct nexthop_adata, ad, nhea->u.ptr) : NULL;
}
/* Route has regular, reachable nexthop (i.e. not RTD_UNREACHABLE and like) */
static inline int rte_is_reachable(rte *r)
{
struct nexthop_adata *nhad = rte_get_nexthops(r);
return nhad && NEXTHOP_IS_REACHABLE(nhad);
}
static inline int nhea_dest(eattr *nhea)
{
if (!nhea)
return RTD_NONE;
struct nexthop_adata *nhad = nhea ? (struct nexthop_adata *) nhea->u.ptr : NULL;
if (NEXTHOP_IS_REACHABLE(nhad))
return RTD_UNICAST;
else
return nhad->dest;
}
static inline int rte_dest(const rte *r)
{
return nhea_dest(ea_find(r->attrs, &ea_gen_nexthop));
}
void rta_init(void);
ea_list *ea_lookup_slow(ea_list *r, u32 squash_upto, enum ea_stored oid);
static inline struct ea_storage *ea_get_storage(ea_list *r)
{
ASSERT_DIE(r->stored);
return SKIP_BACK(struct ea_storage, l[0], r);
}
static inline ea_list *ea_ref(ea_list *r)
{
ASSERT_DIE(0 < atomic_fetch_add_explicit(&ea_get_storage(r)->uc, 1, memory_order_acq_rel));
return r;
}
static inline ea_list *ea_lookup(ea_list *r, u32 squash_upto, enum ea_stored oid)
{
ASSERT_DIE(oid);
if ((r->stored == oid) || BIT32_TEST(&squash_upto, r->stored))
return ea_ref(r);
else
return ea_lookup_slow(r, squash_upto, oid);
}
struct ea_free_deferred {
struct deferred_call dc;
ea_list *attrs;
};
void ea_free_deferred(struct deferred_call *dc);
static inline ea_list *ea_free_later(ea_list *r)
{
if (!r)
return NULL;
struct ea_free_deferred efd = {
.dc.hook = ea_free_deferred,
.attrs = r,
};
defer_call(&efd.dc, sizeof efd);
return r;
}
#define ea_free ea_free_later
static inline ea_list *ea_lookup_tmp(ea_list *r, u32 squash_upto, enum ea_stored oid)
{
return ea_free_later(ea_lookup(r, squash_upto, oid));
}
static inline ea_list *ea_ref_tmp(ea_list *r)
{
ASSERT_DIE(r->stored);
return ea_free_later(ea_ref(r));
}
static inline ea_list *ea_strip_to(ea_list *r, u32 strip_to)
{
ASSERT_DIE(strip_to);
while (r && !BIT32_TEST(&strip_to, r->stored))
r = r->next;
return r;
}
void ea_dump(ea_list *);
void ea_dump_all(void);
void ea_show_list(struct cli *, ea_list *);
#endif