Commit ee76a92a authored by Martin Mareš's avatar Martin Mareš

Implemented real attribute cache.

parent d4d75628
Core
~~~~
- better memory allocators
- real attribute cache
- static: check validity of route destination?
- static: allow specifying a per-route filter program for setting route attributes?
......@@ -16,6 +15,7 @@ Core
Commands
~~~~~~~~
- showing of routing table as seen by given protocol
- printing of dynamic attributes
Documentation
~~~~~~~~~~~~~
......@@ -69,23 +69,3 @@ OSPF
- RFC1587 NSSA areas
- RFC2370 opaque LSA's
- respect interface MTU and try not to create larger packets unless unavoidable
BGP
~~~
- aggregation, ATOMIC_AGGREGATE
- communities
- attributes must be sorted!
- re-export of NEXT_HOP attribute
- BGP session over currently down interface
- LOCAL_PREF attribute
- error notification received -> log error
- set TTL to 1 (configurable?)
- consulting IGP for next-hop information? (what if it changes?)
- inter-advertisement delay???!
- normalize (sort) incoming AS-SET's
- maximum length of AS paths
- expected neighbor AS
- hold time
- idle timer after error: initial value, exponential growth, maximum value
- import of IGP routes (use external route tags from OSPF)
- Use IP_RECVERR for BGP TCP sockets?
......@@ -215,8 +215,7 @@ void rt_show(struct rt_show_data *);
*/
typedef struct rta {
struct rta *next, *prev; /* Hash chain */
struct rta *garbage; /* Garbage collector chain */
struct rta *next, **pprev; /* Hash chain */
struct proto *proto; /* Protocol instance */
unsigned uc; /* Use count */
byte source; /* Route source (RTS_...) */
......@@ -225,7 +224,7 @@ typedef struct rta {
byte dest; /* Route destination type (RTD_...) */
byte flags; /* Route flags (RTF_...), now unused */
byte aflags; /* Attribute cache flags (RTAF_...) */
byte rfu, rfu2; /* Padding */
u16 hash_key; /* Hash over important fields */
ip_addr gw; /* Next hop */
ip_addr from; /* Advertising router */
struct iface *iface; /* Outgoing interface */
......
/*
* BIRD -- Route Attribute Cache
*
* (c) 1998--1999 Martin Mares <mj@ucw.cz>
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
......@@ -16,11 +16,6 @@
#include "nest/cli.h"
#include "lib/resource.h"
/*
* FIXME: Implement hash tables and garbage collection!
*/
static rta *first_rta;
static slab *rta_slab;
static pool *rta_pool;
......@@ -150,9 +145,7 @@ ea_sort(ea_list *e)
ea_do_prune(e);
e->flags |= EALF_SORTED;
}
#if 0 /* FIXME: Remove this after some testing */
if (e->count > 5)
#endif
e->flags |= EALF_BISECT;
e = e->next;
}
......@@ -278,10 +271,70 @@ ea_dump(ea_list *e)
}
}
static inline unsigned int
ea_hash(ea_list *e)
{
u32 h = 0;
int i;
if (e) /* Assuming chain of length 1 */
{
for(i=0; i<e->count; i++)
{
struct eattr *a = &e->attrs[i];
h ^= a->id;
if (a->type & EAF_EMBEDDED)
h ^= a->u.data;
else
{
struct adata *d = a->u.ptr;
int size = d->length;
byte *z = d->data;
while (size >= 4)
{
h ^= *(u32 *)z;
z += 4;
size -= 4;
}
while (size--)
h = (h >> 24) ^ (h << 8) ^ *z++;
}
}
h ^= h >> 16;
h ^= h >> 6;
h &= 0xffff;
}
return h;
}
/*
* rta's
*/
static unsigned int rta_cache_count;
static unsigned int rta_cache_size = 32;
static unsigned int rta_cache_limit;
static unsigned int rta_cache_mask;
static rta **rta_hash_table;
static void
rta_alloc_hash(void)
{
rta_hash_table = mb_alloc(rta_pool, sizeof(rta *) * rta_cache_size);
bzero(rta_hash_table, sizeof(rta *) * rta_cache_size);
if (rta_cache_size < 32768)
rta_cache_limit = rta_cache_size * 2;
else
rta_cache_limit = ~0;
rta_cache_mask = rta_cache_size - 1;
}
static inline unsigned int
rta_hash(rta *a)
{
return a->proto->hash_key ^ ipa_hash(a->gw) ^ ea_hash(a->eattrs);
}
static inline int
rta_same(rta *x, rta *y)
{
......@@ -308,10 +361,42 @@ rta_copy(rta *o)
return r;
}
static inline void
rta_insert(rta *r)
{
unsigned int h = r->hash_key & rta_cache_mask;
r->next = rta_hash_table[h];
if (r->next)
r->next->pprev = &r->next;
r->pprev = &rta_hash_table[h];
rta_hash_table[h] = r;
}
static void
rta_rehash(void)
{
unsigned int ohs = rta_cache_size;
unsigned int h;
rta *r, *n;
rta **oht = rta_hash_table;
rta_cache_size = 2*rta_cache_size;
DBG("Rehashing rta cache from %d to %d entries.\n", ohs, rta_cache_size);
rta_alloc_hash();
for(h=0; h<ohs; h++)
for(r=oht[h]; r; r=n)
{
n = r->next;
rta_insert(r);
}
mb_free(oht);
}
rta *
rta_lookup(rta *o)
{
rta *r;
unsigned int h;
ASSERT(!(o->aflags & RTAF_CACHED));
if (o->eattrs)
......@@ -325,20 +410,27 @@ rta_lookup(rta *o)
ea_sort(o->eattrs);
}
for(r=first_rta; r; r=r->next)
if (rta_same(r, o))
h = rta_hash(o);
for(r=rta_hash_table[h & rta_cache_mask]; r; r=r->next)
if (r->hash_key == h && rta_same(r, o))
return rta_clone(r);
r = rta_copy(o);
r->hash_key = h;
r->aflags = RTAF_CACHED;
r->next = first_rta;
first_rta = r;
rta_insert(r);
if (++rta_cache_count > rta_cache_limit)
rta_rehash();
return r;
}
void
rta__free(rta *a)
{
ASSERT(rta_cache_count && (a->aflags & RTAF_CACHED));
rta_cache_count--;
}
void
......@@ -351,9 +443,9 @@ rta_dump(rta *a)
static char *rtc[] = { "", " BC", " MC", " AC" };
static char *rtd[] = { "", " DEV", " HOLE", " UNREACH", " PROHIBIT" };
debug("p=%s uc=%d %s %s%s%s",
debug("p=%s uc=%d %s %s%s%s h=%04x",
a->proto->name, a->uc, rts[a->source], ip_scope_text(a->scope), rtc[a->cast],
rtd[a->dest]);
rtd[a->dest], a->hash_key);
if (!(a->aflags & RTAF_CACHED))
debug(" !CACHED");
debug(" <-%I", a->from);
......@@ -372,14 +464,16 @@ void
rta_dump_all(void)
{
rta *a;
debug("Route attribute cache:\n");
for(a=first_rta; a; a=a->next)
{
debug("%p ", a);
rta_dump(a);
debug("\n");
}
unsigned int h;
debug("Route attribute cache (%d entries, rehash at %d):\n", rta_cache_count, rta_cache_limit);
for(h=0; h<rta_cache_size; h++)
for(a=rta_hash_table[h]; a; a=a->next)
{
debug("%p ", a);
rta_dump(a);
debug("\n");
}
debug("\n");
}
......@@ -400,4 +494,5 @@ rta_init(void)
{
rta_pool = rp_new(&root_pool, "Attributes");
rta_slab = sl_new(rta_pool, sizeof(rta));
rta_alloc_hash();
}
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