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Functions for matching paths added, tested lightly.

Functions for working with community lists added, they compile.

This should not be definitive place for this stuff.
This commit is contained in:
Pavel Machek 2000-04-10 15:07:43 +00:00
parent 73e03bce66
commit 7f77e25002
2 changed files with 229 additions and 23 deletions

View File

@ -11,6 +11,8 @@
FIXME: IP addresses in ipv6
FIXME: check messages for \n at the end
(1) Cesty
AS paths budtez interne reprezentovany stejne jako v BGP (viz RFC 1771),
@ -22,17 +24,22 @@ mnozina cisel ASu. Na cestach nadefinuji nasledujici operace:
Filtry by mely podporovat:
- operator pridani AS k ceste
- operator pridani AS k ceste [bgp_path_prepend]
- matchovani na pritomnost podposloupnosti v ceste (pricemz vyskytne-li
se tam mnozina, tak si ji lze predstavit prerovnanou v libovolnem
poradi)
- operator zjisteni delky cesty (pro vypocet metrik)
Byl bych rad, kdyby se samotne matchovaci funkce objevily v proto/bgp/attrs.c.
Jsou v sitove endianite. [lib/unaligned.h]
(2) Community-listy
posloupnost 32bitovych cisel s delkou.
Community list budiz interne reprezentovan jako posloupnost 32-bitovych cisel.
Filtry by se mely na communities divat jako na usporadane dvojice 16-bitovych
@ -40,33 +47,14 @@ cisel (prvni je cislo AS, ktery community definoval, druhe pak community ID
v ramci AS) a melo by byt mozne definovat si konstanty typu community.
K dispozici by mely byt nasledujici operace:
- zjisteni pritomnosti community v listu
- pridani community do listu
- odebrani community z listu
- zjisteni pritomnosti community v listu [linearni pruchod]
- pridani community do listu [s kopii]
- odebrani community z listu [s kopii]
- zresetovani listu
Pro operace na cestach i na community listech by se mela pouzivat `teckova'
notace pouzita v mem puvodnim navrhu syntaxe.
(3) Zmeny v semantice dynamickych atributu
Aby se nemusely neustale kopirovat seznamy atributu, rad bych provedl jeste
jednu zmenu v tom, jak filtry nakladaji s atributy (pevne doufam, ze posledni,
ale uznavam, ze u te predchozi jsem to take tvrdil): Funkci f_run budiz
pridan jeste jeden parametr, ktery prepina mezi dvema mody:
(a) [incoming filter mode] Jako nyni.
(b) [outgoing filter mode] Pokud se hleda atribut, hleda se nejdrive
v tmp_attrs a pokud to selze, tak v rta->attrs. Pokud se nastavuje,
dava se _vzdy_ do tmp_attrs.
Diky tomu filtry pri exportu routes nebudou vubec muset modifikovat rta a
protokoly, ktere v import_control potrebuji nastavovat i non-temporary
atributy, je budou moci pridat do tmp_attrs, aniz by sahly na rta.
*/
CF_HDR
@ -83,6 +71,8 @@ CF_KEYWORDS(FUNCTION, PRINT, PRINTN, UNSET, RETURN,
FROM, GW, NET, MASK, SOURCE,
LEN,
DEFINED,
ADD, DELETE, CONTAINS, RESET,
APPEND, MATCH,
FILTER, WHERE)
%nonassoc THEN
@ -400,6 +390,19 @@ term:
| term '.' IP { $$ = f_new_inst(); $$->code = P('c','p'); $$->a1.p = $1; $$->aux = T_IP; }
| term '.' LEN { $$ = f_new_inst(); $$->code = P('c','p'); $$->a1.p = $1; $$->aux = T_INT; }
| term '.' MASK '(' term ')' { $$ = f_new_inst(); $$->code = P('i','M'); $$->a1.p = $1; $$->a2.p = $5; }
/* Communities */
| term '.' ADD '(' term ')' { }
| term '.' DELETE '(' term ')' { }
| term '.' CONTAINS '(' term ')' { }
| term '.' RESET { }
/* Paths */
| term '.' APPEND '(' term ')' { }
/* | term '.' LEN { } Hmm, this would colide with ip.len. What to do with that? */
| term '.' MATCH '(' term ')' { }
/* function_call is inlined here */
| SYM '(' var_list ')' {
struct symbol *sym;

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@ -16,6 +16,7 @@
#include "lib/resource.h"
#include "lib/socket.h"
#include "lib/string.h"
#include "lib/unaligned.h"
#include "nest/route.h"
#include "nest/protocol.h"
#include "nest/iface.h"
@ -133,6 +134,7 @@ val_print(struct f_val v)
case T_SET: tree_print( v.val.t ); PRINTF( "\n" ); break;
case T_ENUM: PRINTF( "(enum %x)%d", v.type, v.val.i ); break;
default: PRINTF( "[unknown type %x]", v.type );
#undef PRINTF
}
debug( buf );
}
@ -554,6 +556,7 @@ filters_postconfig(void)
die( "Startup function resulted in error." );
debug( "done\n" );
}
self_test();
}
int
@ -566,3 +569,203 @@ filter_same(struct filter *new, struct filter *old)
return 0;
return i_same(new->root, old->root);
}
/* This should end up far away from here! */
int
path_getlen(u8 *p, int len)
{
int res = 0;
u8 *q = p+len;
while (p<q) {
switch (*p++) {
case 1: len = *p++; res++; p += 2*len; break;
case 2: len = *p++; res+=len; p += 2*len; break;
default: bug("This should not be in path");
}
}
return res;
}
#define PRINTF(a...) { int l; bsnprintf( buf, 8000, a ); s -= (l = strlen(buf)); if (s<bigbuf) return "Path was much too long"; memcpy(s, buf, l); }
#define COMMA if (first) first = 0; else PRINTF( ", " );
char *
path_format(u8 *p, int len)
{
char bigbuf[4096]; /* Keep it smaller than buf */
char *s = bigbuf+4095;
char buf[8000];
int first = 1;
int i;
u8 *q = p+len;
*s-- = 0;
while (p<q) {
switch (*p++) {
case 1: /* This is a set */
len = *p++;
COMMA;
PRINTF( "}" );
{
int first = 1;
for (i=0; i<len; i++) {
COMMA;
PRINTF( "%d", get_u16(p));
p+=2;
}
}
PRINTF( "{" );
break;
case 2: /* This is a sequence */
len = *p++;
for (i=0; i<len; i++) {
int l;
COMMA;
PRINTF( "%d", get_u16(p));
p+=2;
}
break;
default:
bug("This should not be in path");
}
}
return strdup(s);
}
#undef PRINTF
#undef COMMA
#define PM_END -1
#define PM_ASTERIX -2
#define MASK_PLUS do { if (*++mask == PM_END) return next == q; \
asterix = (*mask == PM_ASTERIX); \
printf( "Asterix now %d\n", asterix ); \
if (asterix) { if (*++mask == PM_END) { printf( "Quick exit\n" ); return 1; } } \
} while(0)
int
path_match(u8 *p, int len, s32 *mask)
{
int i;
int asterix = 0;
u8 *q = p+len;
u8 *next;
while (p<q) {
switch (*p++) {
case 1: /* This is a set */
len = *p++;
{
u8 *p_save = p;
next = p_save + 2*len;
retry:
p = p_save;
for (i=0; i<len; i++) {
if (asterix && (get_u16(p) == *mask)) {
MASK_PLUS;
goto retry;
}
if (!asterix && (get_u16(p) == *mask)) {
p = next;
MASK_PLUS;
goto okay;
}
p+=2;
}
if (!asterix)
return 0;
okay:
}
break;
case 2: /* This is a sequence */
len = *p++;
for (i=0; i<len; i++) {
next = p+2;
if (asterix && (get_u16(p) == *mask))
MASK_PLUS;
else if (!asterix) {
if (get_u16(p) != *mask)
return 0;
MASK_PLUS;
}
p+=2;
}
break;
default:
bug("This should not be in path");
}
}
return 0;
}
struct adata *
comlist_add(struct linpool *pool, struct adata *list, u32 val)
{
struct adata *res = lp_alloc(pool, list->length + sizeof(struct adata) + 4);
res->length = list->length+4;
* (u32 *) res->data = val;
memcpy((char *) res->data + 4, list->data, list->length);
return res;
}
struct adata *
comlist_contains(struct adata *list, u32 val)
{
u32 *l = &(list->data);
int i;
for (i=0; i<list->length/4; i++)
if (*l++ == val)
return 1;
return 0;
}
struct adata *
comlist_del(struct linpool *pool, struct adata *list, u32 val)
{
struct adata *res;
u32 *l, *k;
int i;
if (!comlist_contains(list, val))
return list;
res = lp_alloc(pool, list->length + sizeof(struct adata) - 4);
res->length = list->length-4;
l = &(list->data);
k = &(res->data);
for (i=0; i<list->length/4; i++)
if (l[i] != val)
*k++ = l[i];
return res;
}
struct adata *
comlist_empty(struct linpool *pool)
{
struct adata *res = lp_alloc(pool, sizeof(struct adata));
res->length = 0;
return res;
}
void
self_test(void)
{
char path1[] = { 2, 5, 0, 5, 0, 4, 0, 3, 0, 2, 0, 1 };
char path2[] = { 2, 5, 0, 5, 0, 4, 0, 3, 0, 2, 0, 1, 1, 5, 0, 5, 0, 4, 0, 3, 0, 2, 0, 1 };
s32 match[] = { 5, PM_ASTERIX, 2, PM_ASTERIX, 1, 3, PM_END };
DBG( "Filters self-testing:\n" );
DBG( "%s\n", path_format(path1, sizeof(path1)) );
DBG( "%s\n", path_format(path2, sizeof(path2)) );
DBG( "5, 6 = %d, %d\n", path_getlen(path1, sizeof(path1)), path_getlen(path2, sizeof(path2)) );
DBG( "%d\n", path_match(path1, sizeof(path1), match));
DBG( "%d\n", path_match(path2, sizeof(path2), match));
// die( "okay" );
}