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Minor changes in prefix trie.

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This commit is contained in:
Ondrej Zajicek 2010-07-27 17:17:11 +02:00
parent f2b76f2c45
commit 7f0d245a5e
4 changed files with 70 additions and 58 deletions
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4
filter/config.Y
View file

@ -284,8 +284,8 @@ fprefix:
;
fprefix_set:
fprefix { $$ = f_new_trie(); trie_add_prefix($$, &($1.val.px)); }
| fprefix_set ',' fprefix { $$ = $1; trie_add_prefix($$, &($3.val.px)); }
fprefix { $$ = f_new_trie(cfg_mem); trie_add_fprefix($$, &($1.val.px)); }
| fprefix_set ',' fprefix { $$ = $1; trie_add_fprefix($$, &($3.val.px)); }
;
switch_body: /* EMPTY */ { $$ = NULL; }

4
filter/filter.c
View file

@ -186,7 +186,7 @@ tree_compare(const void *p1, const void *p2)
}
void
f_prefix_get_bounds(struct f_prefix *px, int *l, int *h)
fprefix_get_bounds(struct f_prefix *px, int *l, int *h)
{
*l = *h = px->len & LEN_MASK;
@ -319,7 +319,7 @@ val_in_range(struct f_val v1, struct f_val v2)
return res;
if ((v1.type == T_PREFIX) && (v2.type == T_PREFIX_SET))
return trie_match_prefix(v2.val.ti, &v1.val.px);
return trie_match_fprefix(v2.val.ti, &v1.val.px);
if ((v1.type == T_CLIST) && (v2.type == T_SET))
return clist_match_set(v1.val.ad, v2.val.t);

26
filter/filter.h
View file

@ -70,12 +70,29 @@ struct f_tree *build_tree(struct f_tree *);
struct f_tree *find_tree(struct f_tree *t, struct f_val val);
int same_tree(struct f_tree *t1, struct f_tree *t2);
struct f_trie *f_new_trie(void);
void trie_add_prefix(struct f_trie *t, struct f_prefix *px);
int trie_match_prefix(struct f_trie *t, struct f_prefix *px);
struct f_trie *f_new_trie(linpool *lp);
void trie_add_prefix(struct f_trie *t, ip_addr px, int plen, int l, int h);
int trie_match_prefix(struct f_trie *t, ip_addr px, int plen);
int trie_same(struct f_trie *t1, struct f_trie *t2);
int trie_print(struct f_trie *t, char *buf, int blen);
void fprefix_get_bounds(struct f_prefix *px, int *l, int *h);
static inline void
trie_add_fprefix(struct f_trie *t, struct f_prefix *px)
{
int l, h;
fprefix_get_bounds(px, &l, &h);
trie_add_prefix(t, px->ip, px->len & LEN_MASK, l, h);
}
static inline int
trie_match_fprefix(struct f_trie *t, struct f_prefix *px)
{
return trie_match_prefix(t, px->ip, px->len & LEN_MASK);
}
struct ea_list;
struct rte;
@ -87,9 +104,7 @@ char *filter_name(struct filter *filter);
int filter_same(struct filter *new, struct filter *old);
int i_same(struct f_inst *f1, struct f_inst *f2);
void f_prefix_get_bounds(struct f_prefix *px, int *l, int *h);
void f_prefix_get_bounds(struct f_prefix *px, int *l, int *h);
int val_compare(struct f_val v1, struct f_val v2);
int tree_compare(const void *p1, const void *p2);
void val_print(struct f_val v);
@ -158,6 +173,7 @@ struct f_trie_node
struct f_trie
{
linpool *lp;
int zero;
struct f_trie_node root;
};

94
filter/trie.c
View file

@ -14,7 +14,7 @@
* indicates the index of the bit in the address that is used to
* branch at the node. If we need to represent just a set of
* prefixes, it would be simple, but we have to represent a
* set of prefix pattern. Each prefix pattern consists of
* set of prefix patterns. Each prefix pattern consists of
* &ppaddr/&pplen and two integers: &low and &high, and a prefix
* &paddr/&plen matches that pattern if the first MIN(&plen, &pplen)
* bits of &paddr and &ppaddr are the same and &low <= &plen <= &high.
@ -65,8 +65,8 @@
* - we are beyond the end of path (node length > &plen)
* - we are still on path and keep walking (node length < &plen)
*
* The walking code in add_node_to_trie() and trie_match_prefix()
* is structured according to these cases.
* The walking code in trie_match_prefix() is structured according to
* these cases.
*/
#include "nest/bird.h"
@ -80,17 +80,18 @@
* Allocates and returns a new empty trie.
*/
struct f_trie *
f_new_trie(void)
f_new_trie(linpool *lp)
{
struct f_trie * ret;
ret = cfg_allocz(sizeof(struct f_trie));
ret = lp_allocz(lp, sizeof(struct f_trie));
ret->lp = lp;
return ret;
}
static inline struct f_trie_node *
new_node(int plen, ip_addr paddr, ip_addr pmask, ip_addr amask)
new_node(struct f_trie *t, int plen, ip_addr paddr, ip_addr pmask, ip_addr amask)
{
struct f_trie_node *n = cfg_allocz(sizeof(struct f_trie_node));
struct f_trie_node *n = lp_allocz(t->lp, sizeof(struct f_trie_node));
n->plen = plen;
n->addr = paddr;
n->mask = pmask;
@ -104,11 +105,33 @@ attach_node(struct f_trie_node *parent, struct f_trie_node *child)
parent->c[ipa_getbit(child->addr, parent->plen) ? 1 : 0] = child;
}
static void
add_node_to_trie(struct f_trie *t, int plen, ip_addr ip, ip_addr amask)
/**
* trie_add_prefix
* @t: trie to add to
* @px: prefix address
* @plen: prefix length
* @l: prefix lower bound
* @h: prefix upper bound
*
* Adds prefix (prefix pattern) @px/@plen to trie @t. @l and @h are lower
* and upper bounds on accepted prefix lengths, both inclusive. 0 <=
* l, h <= 32 (128 for IPv6).
*/
void
trie_add_prefix(struct f_trie *t, ip_addr px, int plen, int l, int h)
{
if (l == 0)
t->zero = 1;
else
l--;
if (h < plen)
plen = h;
ip_addr amask = ipa_xor(ipa_mkmask(l), ipa_mkmask(h));
ip_addr pmask = ipa_mkmask(plen);
ip_addr paddr = ipa_and(ip, pmask);
ip_addr paddr = ipa_and(px, pmask);
struct f_trie_node *o = NULL;
struct f_trie_node *n = &t->root;
@ -123,13 +146,13 @@ add_node_to_trie(struct f_trie *t, int plen, ip_addr ip, ip_addr amask)
as the other child of 'b'. */
int blen = ipa_pxlen(paddr, n->addr);
ip_addr bmask = ipa_mkmask(blen);
ip_addr baddr = ipa_and(ip, bmask);
ip_addr baddr = ipa_and(px, bmask);
/* Merge accept masks from children to get accept mask for node 'b' */
ip_addr baccm = ipa_and(ipa_or(amask, n->accept), bmask);
struct f_trie_node *a = new_node(plen, paddr, pmask, amask);
struct f_trie_node *b = new_node(blen, baddr, bmask, baccm);
struct f_trie_node *a = new_node(t, plen, paddr, pmask, amask);
struct f_trie_node *b = new_node(t, blen, baddr, bmask, baccm);
attach_node(o, b);
attach_node(b, n);
attach_node(b, a);
@ -140,7 +163,7 @@ add_node_to_trie(struct f_trie *t, int plen, ip_addr ip, ip_addr amask)
{
/* We add new node 'a' between node 'o' and node 'n' */
amask = ipa_or(amask, ipa_and(n->accept, pmask));
struct f_trie_node *a = new_node(plen, paddr, pmask, amask);
struct f_trie_node *a = new_node(t, plen, paddr, pmask, amask);
attach_node(o, a);
attach_node(a, n);
return;
@ -156,58 +179,31 @@ add_node_to_trie(struct f_trie *t, int plen, ip_addr ip, ip_addr amask)
/* Update accept mask part M2 and go deeper */
n->accept = ipa_or(n->accept, ipa_and(amask, n->mask));
/* n->plen < plen and plen <= 32 */
/* n->plen < plen and plen <= 32 (128) */
o = n;
n = n->c[ipa_getbit(paddr, n->plen) ? 1 : 0];
}
/* We add new tail node 'a' after node 'o' */
struct f_trie_node *a = new_node(plen, paddr, pmask, amask);
struct f_trie_node *a = new_node(t, plen, paddr, pmask, amask);
attach_node(o, a);
}
/**
* trie_add_prefix
* @t: trie to add to
* @px: prefix to add
*
* Adds prefix (prefix pattern) @px to trie @t.
*/
void
trie_add_prefix(struct f_trie *t, struct f_prefix *px)
{
int l, h;
int plen = px->len & LEN_MASK;
/* 'l' and 'h' are lower and upper bounds on accepted
prefix lengths, both inclusive. 0 <= l, h <= 32 */
f_prefix_get_bounds(px, &l, &h);
if (l == 0)
t->zero = 1;
else
l--;
ip_addr amask = ipa_xor(ipa_mkmask(l), ipa_mkmask(h));
/* MIN(plen, h) instead of just plen is a little trick. */
add_node_to_trie(t, MIN(plen, h), px->ip, amask);
}
/**
* trie_match_prefix
* trie_match
* @t: trie
* @px: prefix
* @px: prefix address
* @plen: prefix length
*
* Tries to find a matching prefix pattern in the trie such that
* prefix @px matches that prefix pattern. Returns 1 if there
* prefix @px/@plen matches that prefix pattern. Returns 1 if there
* is such prefix pattern in the trie.
*/
int
trie_match_prefix(struct f_trie *t, struct f_prefix *px)
trie_match_prefix(struct f_trie *t, ip_addr px, int plen)
{
int plen = px->len & LEN_MASK;
ip_addr pmask = ipa_mkmask(plen);
ip_addr paddr = ipa_and(px->ip, pmask);
ip_addr paddr = ipa_and(px, pmask);
if (plen == 0)
return t->zero;