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
parent
73e03bce66
commit
7f77e25002
2 changed files with 229 additions and 23 deletions
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@ -11,6 +11,8 @@
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FIXME: IP addresses in ipv6
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FIXME: check messages for \n at the end
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(1) Cesty
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AS paths budtez interne reprezentovany stejne jako v BGP (viz RFC 1771),
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@ -22,17 +24,22 @@ mnozina cisel ASu. Na cestach nadefinuji nasledujici operace:
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Filtry by mely podporovat:
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- operator pridani AS k ceste
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- operator pridani AS k ceste [bgp_path_prepend]
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- matchovani na pritomnost podposloupnosti v ceste (pricemz vyskytne-li
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se tam mnozina, tak si ji lze predstavit prerovnanou v libovolnem
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poradi)
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- operator zjisteni delky cesty (pro vypocet metrik)
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Byl bych rad, kdyby se samotne matchovaci funkce objevily v proto/bgp/attrs.c.
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Jsou v sitove endianite. [lib/unaligned.h]
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(2) Community-listy
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posloupnost 32bitovych cisel s delkou.
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Community list budiz interne reprezentovan jako posloupnost 32-bitovych cisel.
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Filtry by se mely na communities divat jako na usporadane dvojice 16-bitovych
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@ -40,33 +47,14 @@ cisel (prvni je cislo AS, ktery community definoval, druhe pak community ID
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v ramci AS) a melo by byt mozne definovat si konstanty typu community.
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K dispozici by mely byt nasledujici operace:
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- zjisteni pritomnosti community v listu
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- pridani community do listu
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- odebrani community z listu
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- zjisteni pritomnosti community v listu [linearni pruchod]
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- pridani community do listu [s kopii]
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- odebrani community z listu [s kopii]
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- zresetovani listu
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Pro operace na cestach i na community listech by se mela pouzivat `teckova'
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notace pouzita v mem puvodnim navrhu syntaxe.
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(3) Zmeny v semantice dynamickych atributu
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Aby se nemusely neustale kopirovat seznamy atributu, rad bych provedl jeste
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jednu zmenu v tom, jak filtry nakladaji s atributy (pevne doufam, ze posledni,
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ale uznavam, ze u te predchozi jsem to take tvrdil): Funkci f_run budiz
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pridan jeste jeden parametr, ktery prepina mezi dvema mody:
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(a) [incoming filter mode] Jako nyni.
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(b) [outgoing filter mode] Pokud se hleda atribut, hleda se nejdrive
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v tmp_attrs a pokud to selze, tak v rta->attrs. Pokud se nastavuje,
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dava se _vzdy_ do tmp_attrs.
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Diky tomu filtry pri exportu routes nebudou vubec muset modifikovat rta a
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protokoly, ktere v import_control potrebuji nastavovat i non-temporary
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atributy, je budou moci pridat do tmp_attrs, aniz by sahly na rta.
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*/
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CF_HDR
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@ -83,6 +71,8 @@ CF_KEYWORDS(FUNCTION, PRINT, PRINTN, UNSET, RETURN,
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FROM, GW, NET, MASK, SOURCE,
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LEN,
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DEFINED,
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ADD, DELETE, CONTAINS, RESET,
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APPEND, MATCH,
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FILTER, WHERE)
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%nonassoc THEN
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@ -400,6 +390,19 @@ term:
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| term '.' IP { $$ = f_new_inst(); $$->code = P('c','p'); $$->a1.p = $1; $$->aux = T_IP; }
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| term '.' LEN { $$ = f_new_inst(); $$->code = P('c','p'); $$->a1.p = $1; $$->aux = T_INT; }
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| term '.' MASK '(' term ')' { $$ = f_new_inst(); $$->code = P('i','M'); $$->a1.p = $1; $$->a2.p = $5; }
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/* Communities */
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| term '.' ADD '(' term ')' { }
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| term '.' DELETE '(' term ')' { }
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| term '.' CONTAINS '(' term ')' { }
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| term '.' RESET { }
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/* Paths */
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| term '.' APPEND '(' term ')' { }
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/* | term '.' LEN { } Hmm, this would colide with ip.len. What to do with that? */
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| term '.' MATCH '(' term ')' { }
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/* function_call is inlined here */
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| SYM '(' var_list ')' {
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struct symbol *sym;
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203
filter/filter.c
203
filter/filter.c
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@ -16,6 +16,7 @@
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#include "lib/resource.h"
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#include "lib/socket.h"
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#include "lib/string.h"
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#include "lib/unaligned.h"
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#include "nest/route.h"
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#include "nest/protocol.h"
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#include "nest/iface.h"
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@ -133,6 +134,7 @@ val_print(struct f_val v)
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case T_SET: tree_print( v.val.t ); PRINTF( "\n" ); break;
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case T_ENUM: PRINTF( "(enum %x)%d", v.type, v.val.i ); break;
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default: PRINTF( "[unknown type %x]", v.type );
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#undef PRINTF
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}
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debug( buf );
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}
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@ -554,6 +556,7 @@ filters_postconfig(void)
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die( "Startup function resulted in error." );
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debug( "done\n" );
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}
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self_test();
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}
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int
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@ -566,3 +569,203 @@ filter_same(struct filter *new, struct filter *old)
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return 0;
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return i_same(new->root, old->root);
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}
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/* This should end up far away from here! */
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int
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path_getlen(u8 *p, int len)
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{
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int res = 0;
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u8 *q = p+len;
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while (p<q) {
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switch (*p++) {
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case 1: len = *p++; res++; p += 2*len; break;
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case 2: len = *p++; res+=len; p += 2*len; break;
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default: bug("This should not be in path");
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}
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}
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return res;
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}
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#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); }
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#define COMMA if (first) first = 0; else PRINTF( ", " );
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char *
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path_format(u8 *p, int len)
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{
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char bigbuf[4096]; /* Keep it smaller than buf */
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char *s = bigbuf+4095;
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char buf[8000];
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int first = 1;
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int i;
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u8 *q = p+len;
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*s-- = 0;
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while (p<q) {
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switch (*p++) {
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case 1: /* This is a set */
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len = *p++;
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COMMA;
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PRINTF( "}" );
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{
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int first = 1;
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for (i=0; i<len; i++) {
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COMMA;
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PRINTF( "%d", get_u16(p));
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p+=2;
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}
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}
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PRINTF( "{" );
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break;
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case 2: /* This is a sequence */
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len = *p++;
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for (i=0; i<len; i++) {
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int l;
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COMMA;
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PRINTF( "%d", get_u16(p));
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p+=2;
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}
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break;
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default:
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bug("This should not be in path");
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}
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}
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return strdup(s);
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}
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#undef PRINTF
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#undef COMMA
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#define PM_END -1
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#define PM_ASTERIX -2
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#define MASK_PLUS do { if (*++mask == PM_END) return next == q; \
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asterix = (*mask == PM_ASTERIX); \
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printf( "Asterix now %d\n", asterix ); \
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if (asterix) { if (*++mask == PM_END) { printf( "Quick exit\n" ); return 1; } } \
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} while(0)
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int
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path_match(u8 *p, int len, s32 *mask)
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{
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int i;
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int asterix = 0;
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u8 *q = p+len;
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u8 *next;
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while (p<q) {
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switch (*p++) {
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case 1: /* This is a set */
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len = *p++;
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{
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u8 *p_save = p;
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next = p_save + 2*len;
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retry:
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p = p_save;
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for (i=0; i<len; i++) {
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if (asterix && (get_u16(p) == *mask)) {
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MASK_PLUS;
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goto retry;
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}
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if (!asterix && (get_u16(p) == *mask)) {
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p = next;
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MASK_PLUS;
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goto okay;
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}
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p+=2;
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}
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if (!asterix)
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return 0;
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okay:
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}
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break;
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case 2: /* This is a sequence */
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len = *p++;
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for (i=0; i<len; i++) {
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next = p+2;
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if (asterix && (get_u16(p) == *mask))
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MASK_PLUS;
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else if (!asterix) {
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if (get_u16(p) != *mask)
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return 0;
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MASK_PLUS;
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}
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p+=2;
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}
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break;
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default:
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bug("This should not be in path");
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}
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}
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return 0;
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}
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struct adata *
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comlist_add(struct linpool *pool, struct adata *list, u32 val)
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{
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struct adata *res = lp_alloc(pool, list->length + sizeof(struct adata) + 4);
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res->length = list->length+4;
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* (u32 *) res->data = val;
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memcpy((char *) res->data + 4, list->data, list->length);
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return res;
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}
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struct adata *
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comlist_contains(struct adata *list, u32 val)
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{
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u32 *l = &(list->data);
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int i;
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for (i=0; i<list->length/4; i++)
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if (*l++ == val)
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return 1;
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return 0;
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}
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struct adata *
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comlist_del(struct linpool *pool, struct adata *list, u32 val)
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{
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struct adata *res;
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u32 *l, *k;
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int i;
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if (!comlist_contains(list, val))
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return list;
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res = lp_alloc(pool, list->length + sizeof(struct adata) - 4);
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res->length = list->length-4;
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l = &(list->data);
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k = &(res->data);
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for (i=0; i<list->length/4; i++)
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if (l[i] != val)
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*k++ = l[i];
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return res;
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}
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struct adata *
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comlist_empty(struct linpool *pool)
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{
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struct adata *res = lp_alloc(pool, sizeof(struct adata));
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res->length = 0;
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return res;
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}
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void
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self_test(void)
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{
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char path1[] = { 2, 5, 0, 5, 0, 4, 0, 3, 0, 2, 0, 1 };
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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 };
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s32 match[] = { 5, PM_ASTERIX, 2, PM_ASTERIX, 1, 3, PM_END };
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DBG( "Filters self-testing:\n" );
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DBG( "%s\n", path_format(path1, sizeof(path1)) );
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DBG( "%s\n", path_format(path2, sizeof(path2)) );
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DBG( "5, 6 = %d, %d\n", path_getlen(path1, sizeof(path1)), path_getlen(path2, sizeof(path2)) );
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DBG( "%d\n", path_match(path1, sizeof(path1), match));
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DBG( "%d\n", path_match(path2, sizeof(path2), match));
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// die( "okay" );
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}
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