bird/nest/route.h
Ondrej Zajicek c0adf7e9fc Better support for multitable protocols.
The nest-protocol interaction is changed to better handle multitable
protocols. Multitable protocols now declare that by 'multitable' field,
which tells nest that a protocol handles things related to proto-rtable
interaction (table locking, announce hook adding, reconfiguration of
filters) itself.

Filters and stats are moved to announce hooks, a protocol could have
different filters and stats to different tables.

The patch is based on one from Alexander V. Chernikov, thanks.
2012-03-15 12:13:04 +01:00

459 lines
17 KiB
C

/*
* BIRD Internet Routing Daemon -- Routing Table
*
* (c) 1998--2000 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/lists.h"
#include "lib/resource.h"
#include "lib/timer.h"
#include "nest/protocol.h"
struct protocol;
struct proto;
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 pxlen;
byte flags; /* User-defined */
byte x0, x1; /* User-defined */
u32 uid; /* Unique ID based on hash */
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! */
byte efef; /* 0xff to distinguish between iterator and node */
byte pad[3];
struct fib_node *node; /* Or NULL if freshly merged */
unsigned int hash;
};
typedef void (*fib_init_func)(struct fib_node *);
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) */
fib_init_func init; /* Constructor */
};
void fib_init(struct fib *, pool *, unsigned node_size, unsigned hash_order, fib_init_func init);
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_route(struct fib *, ip_addr, int); /* 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 *);
#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(;;) { \
if (!z) \
{ \
if (++hpos >= count) \
break; \
z = (fib)->hash_table[hpos]; \
continue; \
}
#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 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 */
int gc_max_ops; /* Maximum number of operations before GC is run */
int gc_min_time; /* Minimum time between two consecutive GC runs */
};
typedef struct rtable {
node n; /* Node in list of all tables */
struct fib fib;
char *name; /* Name of this table */
list hooks; /* List of announcement hooks */
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 gc_scheduled; /* GC is scheduled */
byte hcu_scheduled; /* Hostcache update is scheduled */
byte nhu_state; /* Next Hop Update state */
struct fib_iterator nhu_fit; /* Next Hop Update FIB iterator */
} rtable;
typedef struct network {
struct fib_node n; /* FIB flags reserved for kernel syncer */
struct rte *routes; /* Available routes for this network */
} 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 */
ip_addr gw; /* 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 announce_hook *sender; /* Announce hook 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 {
node garbage; /* List for garbage collection */
byte metric; /* RIP metric */
u16 tag; /* External route tag */
struct rip_entry *entry;
} 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
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 type; /* Kernel route type */
u8 seen; /* Seen during last scan */
u32 metric; /* Kernel metric */
} krt;
} u;
} rte;
#define REF_COW 1 /* Copy this rte on write */
/* Types of route announcement, also used as flags */
#define RA_OPTIMAL 1 /* Announcement of optimal route change */
#define RA_ANY 2 /* Announcement of any route change */
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, ip_addr addr, unsigned len) { return (net *) fib_find(&tab->fib, &addr, len); }
static inline net *net_get(rtable *tab, ip_addr addr, unsigned len) { return (net *) fib_get(&tab->fib, &addr, len); }
rte *rte_find(net *net, struct proto *p);
rte *rte_get_temp(struct rta *);
void rte_update2(struct announce_hook *ah, net *net, rte *new, struct proto *src);
static inline void rte_update(rtable *tab, net *net, struct proto *p, struct proto *src, rte *new) { rte_update2(p->main_ahook, net, new, src); }
void rte_discard(rtable *tab, rte *old);
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; }
void rt_dump(rtable *);
void rt_dump_all(void);
int rt_feed_baby(struct proto *p);
void rt_feed_baby_abort(struct proto *p);
void rt_prune_all(void);
struct rtable_config *rt_new_table(struct symbol *s);
struct rt_show_data {
ip_addr prefix;
unsigned pxlen;
rtable *table;
struct filter *filter;
int verbose;
struct fib_iterator fit;
struct proto *show_protocol;
struct proto *export_protocol;
int export_mode, primary_only;
struct config *running_on_config;
int net_counter, rt_counter, show_counter;
int stats, show_for;
};
void rt_show(struct rt_show_data *);
/*
* 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.
*/
/* Multipath next-hop */
struct mpnh {
ip_addr gw; /* Next hop */
struct iface *iface; /* Outgoing interface */
struct mpnh *next;
unsigned char weight;
};
typedef struct rta {
struct rta *next, **pprev; /* Hash chain */
struct proto *proto; /* Protocol instance that originally created the route */
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 flags; /* Route flags (RTF_...), now unused */
byte aflags; /* Attribute cache flags (RTAF_...) */
u16 hash_key; /* Hash over important fields */
u32 igp_metric; /* IGP metric to next hop (for iBGP routes) */
ip_addr gw; /* Next hop */
ip_addr from; /* Advertising router */
struct hostentry *hostentry; /* Hostentry for recursive next-hops */
struct iface *iface; /* Outgoing interface */
struct mpnh *nexthops; /* Next-hops for multipath routes */
struct ea_list *eattrs; /* 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_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 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 RTD_MULTIPATH 5 /* Multipath route (nexthops != NULL) */
#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 */
/*
* 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_MAX 5
#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 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 */
#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_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_UNDEF 0x0f /* `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 0x40 /* The attribute has originated locally */
#define EAF_TEMP 0x80 /* A temporary attribute (the one stored in the tmp attr list) */
struct adata {
unsigned int length; /* Length of data */
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);
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 */
unsigned int ea_hash(ea_list *e); /* Calculate 16-bit hash value */
ea_list *ea_append(ea_list *to, ea_list *what);
int mpnh__same(struct mpnh *x, struct mpnh *y); /* Compare multipath nexthops */
static inline int mpnh_same(struct mpnh *x, struct mpnh *y)
{ return (x == y) || mpnh__same(x, y); }
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);
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. The protocol
* responsible for routes with recursive next hops should also hold a
* lock for a table governing that routes (argument tab to
* rta_set_recursive_next_hop()).
*/
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_RIP 120 /* RIP */
#define DEF_PREF_BGP 100 /* BGP */
#define DEF_PREF_PIPE 70 /* Routes piped from other tables */
#define DEF_PREF_INHERITED 10 /* Routes inherited from other routing daemons */
#endif