bird/nest/route.h
Jan Moskyto Matejka 9a74622ca1 Updated RTA hashes to 32-bit values.
... and reworked the hashes a bit. Also added mem_hash function
which just computes a hash of given memory block.
2016-02-10 13:26:07 +01:00

566 lines
22 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 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 */
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 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
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 */
#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); }
rte *rte_find(net *net, struct rte_src *src);
rte *rte_get_temp(struct rta *);
void rte_update2(struct channel *c, net *net, rte *new, struct rte_src *src);
/* rte_update() moved to protocol.h to avoid dependency conflicts */
void rte_discard(rtable *tab, rte *old);
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, 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.
*/
/* Multipath next-hop */
struct mpnh {
ip_addr gw; /* Next hop */
struct iface *iface; /* Outgoing interface */
struct mpnh *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 mpnh *nexthops; /* Next-hops for multipath routes */
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 */
struct iface *iface; /* Outgoing interface */
ip_addr gw; /* Next hop */
ip_addr from; /* Advertising router */
u32 igp_metric; /* IGP metric to next hop (for iBGP routes) */
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_...) */
} 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 */
/* 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_ROUTER) || (d == RTD_DEVICE) || (d == RTD_MULTIPATH); }
/*
* 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 EA_BIT(n) ((n) << 24) /* Used in bitfield accessors */
#define EAF_TYPE_MASK 0x0f /* 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_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 {
uint length; /* Length of data */
byte data[0];
};
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 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); }
struct mpnh *mpnh_merge(struct mpnh *x, struct mpnh *y, int rx, int ry, int max, linpool *lp);
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_RIP 120 /* RIP */
#define DEF_PREF_BGP 100 /* BGP */
#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
byte net_roa_check(rtable *tab, const net_addr *n, u32 asn);
#endif