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authorMartin Mares <mj@ucw.cz>2000-03-04 22:09:14 +0100
committerMartin Mares <mj@ucw.cz>2000-03-04 22:09:14 +0100
commitee76a92a80a0241421f57fe332c251255d2af4f8 (patch)
tree597fbcff4e8dd94ee89c67162099e47d0ae9841a
parentd4d7562806b7306d6e5ed9b759906e264b743dc5 (diff)
downloadbird-ee76a92a80a0241421f57fe332c251255d2af4f8.tar
bird-ee76a92a80a0241421f57fe332c251255d2af4f8.zip
Implemented real attribute cache.
-rw-r--r--TODO22
-rw-r--r--nest/route.h5
-rw-r--r--nest/rt-attr.c139
3 files changed, 120 insertions, 46 deletions
diff --git a/TODO b/TODO
index 9989d89..ccbe59c 100644
--- a/TODO
+++ b/TODO
@@ -1,7 +1,6 @@
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?
diff --git a/nest/route.h b/nest/route.h
index 8b14c85..74fbf9c 100644
--- a/nest/route.h
+++ b/nest/route.h
@@ -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 */
diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index 99d063e..43bf5fe 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -1,7 +1,7 @@
/*
* 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();
}