bird/nest/route.h

303 lines
10 KiB
C

/*
* BIRD Internet Routing Daemon -- Routing Table
*
* (c) 1998 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#ifndef _BIRD_ROUTE_H_
#define _BIRD_ROUTE_H_
#include "lib/resource.h"
#include "lib/timer.h"
struct protocol;
struct proto;
/*
* 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 pxlen;
byte flags; /* User-defined */
byte x0, x1; /* User-defined */
ip_addr prefix; /* In host order */
};
struct fib_iterator { /* See lib/slists.h for an explanation */
struct fib_iterator *prev, *next; /* Must be synced with struct fib_node! */
struct fib_node *node; /* Or NULL if freshly merged */
byte efef; /* 0xff to distinguish between iterator and node */
byte pad[3];
unsigned int hash;
};
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 */
unsigned int hash_size; /* Number of hash table entries (a power of two) */
unsigned int hash_order; /* Binary logarithm of hash_size */
unsigned int hash_shift; /* 16 - hash_log */
unsigned int entries; /* Number of entries */
unsigned int entries_min, entries_max;/* Entry count limits (else start rehashing) */
void (*init)(struct fib_node *); /* Constructor */
};
void fib_init(struct fib *, pool *, unsigned node_size, unsigned hash_order, void (*init)(struct fib_node *));
void *fib_find(struct fib *, ip_addr *, int); /* Find or return NULL if doesn't exist */
void *fib_get(struct fib *, ip_addr *, int); /* Find or create new if nonexistent */
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 *);
#define FIB_WALK(fib, z) do { \
struct fib_node *z, **ff = (fib)->hash_table; \
unsigned int count = (fib)->hash_size; \
while (count--) \
for(z = *ff++; z; z=z->next)
#define FIB_WALK_END } while (0)
#define FIB_ITERATE_INIT(it, fib) fit_init(it, fib)
#define FIB_ITERATE_START(fib, it, z) do { \
struct fib_node *z = fit_get(fib, it); \
unsigned int count = (fib)->hash_size; \
unsigned int hpos = (it)->hash; \
for(;;) { \
fis_again: if (!z) { \
if (++hpos >= count) \
break; \
z = (fib)->hash_table[hpos]; \
goto fis_again; \
}
#define FIB_ITERATE_END(z) z = z->next; } } while(0)
#define FIB_ITERATE_PUT(it, z) fit_put(it, z)
/*
* Master Routing Tables. Generally speaking, each of them is a list
* of FIB (one per TOS) with each entry pointing to a list of route entries
* representing routes to given network.
* 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,source) triplet.
*/
typedef struct rtable {
struct rtable *sibling; /* Our sibling for different TOS */
byte tos; /* TOS for this table */
struct fib fib;
char *name; /* Name of this table */
} rtable;
typedef struct network {
struct fib_node n; /* FIB flags reserved for kernel syncer */
struct rte *routes; /* Available routes for this network */
} net;
typedef struct rte {
struct rte *next;
net *net; /* Network this RTE belongs to */
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 {
node garbage; /* List for garbage collection */
byte 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 */
} ospf;
#endif
#ifdef CONFIG_BGP
struct {
} bgp;
#endif
struct { /* Routes internally generated by krt sync */
int src; /* Alleged route source (see krt.h) */
} krt_sync;
} u;
} rte;
#define REF_CHOSEN 1 /* Currently chosen route */
extern rtable master_table;
void rt_init(void);
void rt_setup(rtable *, char *);
net *net_find(rtable *tab, unsigned tos, ip_addr addr, unsigned len);
net *net_get(rtable *tab, unsigned tos, ip_addr addr, unsigned len);
rte *rte_find(net *net, struct proto *p);
rte *rte_get_temp(struct rta *);
void rte_update(net *net, struct proto *p, rte *new);
void rte_discard(rte *old);
void rte_dump(rte *);
void rte_free(rte *);
void rt_dump(rtable *);
void rt_dump_all(void);
void rt_feed_baby(struct proto *p);
void rt_prune(rtable *tab);
/*
* 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.
*/
typedef struct rta {
struct rta *next, *prev; /* Hash chain */
struct rta *garbage; /* Garbage collector chain */
struct proto *proto; /* Protocol instance */
unsigned uc; /* Use count */
byte source; /* Route source (RTS_...) */
byte scope; /* Route scope (SCOPE_... -- see ip.h) */
byte cast; /* Casting type (RTC_...) */
byte dest; /* Route destination type (RTD_...) */
byte tos; /* TOS of this route */
byte flags; /* Route flags (RTF_...) */
byte aflags; /* Attribute cache flags (RTAF_...) */
byte rfu; /* Padding */
ip_addr gw; /* Next hop */
ip_addr from; /* Advertising router */
struct iface *iface; /* Outgoing interface */
struct ea_list *attrs; /* Extended Attribute chain */
} 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_RIP_EXT 7 /* RIP external route */
#define RTS_OSPF 8 /* OSPF route */
#define RTS_OSPF_EXT 9 /* OSPF external route */
#define RTS_OSPF_IA 10 /* OSPF inter-area route */
#define RTS_OSPF_BOUNDARY 11 /* OSPF route to boundary router (???) */
#define RTS_BGP 12 /* BGP route */
#define RTC_UNICAST 0
#define RTC_BROADCAST 1
#define RTC_MULTICAST 2
#define RTC_ANYCAST 3 /* IPv6 Anycast */
#define RTD_ROUTER 0 /* Next hop is neighbor router */
#define RTD_DEVICE 1 /* Points to device */
#define RTD_BLACKHOLE 2 /* Silently drop packets */
#define RTD_UNREACHABLE 3 /* Reject as unreachable */
#define RTD_PROHIBIT 4 /* Administratively prohibited */
#define RTF_EXTERIOR 1 /* Learned via exterior protocol */
#define RTF_TAGGED 2 /* Tagged external route learned via IGP */
#define RTAF_CACHED 1 /* This is a cached rta */
/*
* 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;
/* FIXME: Introduce real protocol numbers? */
#define EAP_GENERIC 0 /* Generic attributes */
#define EAP_BGP 1 /* BGP attributes */
#define EA_CODE(proto,id) (((proto) << 8) | (id))
#define EA_PROTO(ea) ((ea) >> 8)
#define EA_ID(ea) ((ea) & 0xff)
#define EAF_TYPE_MASK 0x0f /* Mask with this to get type */
#define EAF_TYPE_INT 0x01 /* 32-bit signed integer number */
#define EAF_TYPE_OPAQUE 0x02 /* Opaque byte string (not filterable) */
#define EAF_TYPE_IP_ADDRESS 0x04 /* IP address [FIXME: embed at least for IPv4?] */
#define EAF_TYPE_AS_PATH 0x06 /* BGP AS path [FIXME: define storage layout] */
#define EAF_TYPE_INT_SET 0x0a /* Set of integers (e.g., a community list) */
#define EAF_EMBEDDED 0x01 /* Data stored in eattr.u.data (part of type spec) */
#define EAF_VAR_LENGTH 0x02 /* Attribute length is variable */
#define EAF_INLINE 0x80 /* Copy of an attribute inlined in rte (temporary ea_lists only) */
struct adata {
unsigned int length;
byte data[0];
};
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 */
eattr *ea_find(ea_list *, unsigned ea);
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 (0=merge not needed) */
void ea_merge(ea_list *from, ea_list *to); /* Merge sub-lists to allocated buffer */
void rta_init(void);
rta *rta_lookup(rta *); /* Get rta equivalent to this one, uc++ */
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); }
void rta_dump(rta *);
void rta_dump_all(void);
static inline eattr * rta_find(rta *a, unsigned ea) { return ea_find(a->attrs, ea); }
/*
* Default protocol preferences
*/
#define DEF_PREF_DIRECT 240 /* Directly connected */
#define DEF_PREF_STATIC 200 /* Static route */
#define DEF_PREF_OSPF_INTERNAL 150 /* OSPF intra-area, inter-area and type 1 external routes */
#define DEF_PREF_RIP 120 /* RIP */
#define DEF_PREF_BGP 100 /* BGP */
#define DEF_PREF_OSPF_EXTERNAL 80 /* OSPF external routes */
#define DEF_PREF_RIP_EXTERNAL 70 /* RIP external routes */
#define DEF_PREF_UKR 50 /* Unidentified Kernel Route */
#define DEF_PREF_SINK 10 /* Sink route */
#endif