From 0a06a9b8b3dbd59c850303c49eea97c12e1ac0ff Mon Sep 17 00:00:00 2001
From: Pavel Machek <pavel@ucw.cz>
Date: Wed, 29 Mar 2000 09:02:00 +0000
Subject: f_run gets one more parameter to distinguish between in and out
 modes.

---
 filter/config.Y | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 filter/filter.c | 13 ++++++++++---
 filter/filter.h |  4 +++-
 3 files changed, 71 insertions(+), 4 deletions(-)

(limited to 'filter')

diff --git a/filter/config.Y b/filter/config.Y
index 00aeefc..413e88c 100644
--- a/filter/config.Y
+++ b/filter/config.Y
@@ -9,6 +9,64 @@
 	FIXME (for BGP): whole system of paths, path ~ string, path.prepend(), path.originate
 	FIXME: create community lists
 	FIXME: IP addresses in ipv6
+
+
+(1) Cesty
+
+   AS paths budtez interne reprezentovany stejne jako v BGP (viz RFC 1771),
+to znamena jako posloupnost segmentu, z nichz kazdy je budto posloupnost nebo
+mnozina cisel ASu. Na cestach nadefinuji nasledujici operace:
+
+        - zformatovani do stringu
+        - append dalsiho AS k ceste
+
+Filtry by mely podporovat:
+
+        - operator pridani AS k ceste
+        - 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.
+
+
+(2) Community-listy
+
+Community list budiz interne reprezentovan jako posloupnost 32-bitovych cisel.
+
+Filtry by se mely na communities divat jako na usporadane dvojice 16-bitovych
+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
+        - 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
diff --git a/filter/filter.c b/filter/filter.c
index 5faabfe..6a59072 100644
--- a/filter/filter.c
+++ b/filter/filter.c
@@ -145,6 +145,7 @@ val_print(struct f_val v)
 static struct rte **f_rte, *f_rte_old;
 static struct linpool *f_pool;
 static struct ea_list **f_tmp_attrs;
+static int f_flags;
 
 #define runtime(x) do { \
     log( L_ERR x ); \
@@ -329,9 +330,14 @@ interpret(struct f_inst *what)
     break;
   case P('e','a'):	/* Access to extended attributes */
     {
-      eattr *e = ea_find( (*f_rte)->attrs->eattrs, what->a2.i );
+      eattr *e = NULL;
+      if (!(f_flags & FF_OUTGOING))
+	e = ea_find( (*f_rte)->attrs->eattrs, what->a2.i );
       if (!e) 
 	e = ea_find( (*f_tmp_attrs), what->a2.i );
+      if ((!e) && (f_flags & FF_OUTGOING))
+	e = ea_find( (*f_rte)->attrs->eattrs, what->a2.i );
+      
       if (!e) {
 	res.type = T_VOID;
 	break;
@@ -371,7 +377,7 @@ interpret(struct f_inst *what)
 	break;
       }
 
-      if (!(what->aux & EAF_TEMP)) {
+      if (!(what->aux & EAF_TEMP) && (!(f_flags & FF_OUTGOING))) {
 	*f_rte = rte_do_cow(*f_rte);
 	l->next = (*f_rte)->attrs->eattrs;
 	(*f_rte)->attrs->eattrs = l;
@@ -523,12 +529,13 @@ i_same(struct f_inst *f1, struct f_inst *f2)
 }
 
 int
-f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struct linpool *tmp_pool)
+f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struct linpool *tmp_pool, int flags)
 {
   struct f_inst *inst;
   struct f_val res;
   DBG( "Running filter `%s'...", filter->name );
 
+  f_flags = flags;
   f_tmp_attrs = tmp_attrs;
   f_rte = rte;
   f_rte_old = *rte;
diff --git a/filter/filter.h b/filter/filter.h
index 3f05f6a..b05e6a7 100644
--- a/filter/filter.h
+++ b/filter/filter.h
@@ -67,7 +67,7 @@ int same_tree(struct f_tree *t1, struct f_tree *t2);
 struct ea_list;
 struct rte;
 
-int f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struct linpool *tmp_pool);
+int f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struct linpool *tmp_pool, int flags);
 char *filter_name(struct filter *filter);
 int filter_same(struct filter *new, struct filter *old);
 
@@ -122,4 +122,6 @@ struct f_tree {
 
 #define NEW_F_VAL struct f_val * val; val = cfg_alloc(sizeof(struct f_val));
 
+#define FF_OUTGOING 1
+
 #endif
-- 
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