From 874b868544c3a6ba45ace062091cc3aee007b719 Mon Sep 17 00:00:00 2001
From: Ondrej Zajicek <santiago@crfreenet.org>
Date: Fri, 29 May 2009 22:49:30 +0200
Subject: [PATCH] Implements primary address selection base on 'primary'
 option.

---
 conf/confbase.Y   |  6 +++++
 nest/iface.c      | 46 ++++++++++++++++++++++++--------------
 nest/iface.h      |  1 +
 sysdep/unix/krt.Y |  2 +-
 sysdep/unix/krt.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 94 insertions(+), 17 deletions(-)

diff --git a/conf/confbase.Y b/conf/confbase.Y
index 43854623..a2df85dc 100644
--- a/conf/confbase.Y
+++ b/conf/confbase.Y
@@ -57,6 +57,7 @@ CF_DECLS
 %type <time> datetime
 %type <a> ipa
 %type <px> prefix prefix_or_ipa
+%type <t> text_or_none
 
 %nonassoc PREFIX_DUMMY
 %nonassoc '=' '<' '>' '~' '.' GEQ LEQ NEQ AND OR PO PC
@@ -153,6 +154,11 @@ datetime:
    }
  ;
 
+text_or_none:
+   TEXT { $$ = $1; }
+ |      { $$ = NULL; }
+ ;
+
 CF_CODE
 
 CF_END
diff --git a/nest/iface.c b/nest/iface.c
index 01f25810..5e88b21b 100644
--- a/nest/iface.c
+++ b/nest/iface.c
@@ -399,29 +399,43 @@ if_find_by_name(char *name)
   return NULL;
 }
 
+struct ifa *kif_choose_primary(struct iface *i);
+
 static int
 ifa_recalc_primary(struct iface *i)
 {
-  struct ifa *a, *b = NULL;
-  int res;
+  struct ifa *a = kif_choose_primary(i);
 
-  WALK_LIST(a, i->addrs)
+  if (a == i->addr)
+    return 0;
+
+  if (i->addr)
+    i->addr->flags &= ~IA_PRIMARY;
+
+  if (a)
     {
-      if (!(a->flags & IA_SECONDARY) && (!b || a->scope > b->scope))
-	b = a;
-      a->flags &= ~IA_PRIMARY;
+      a->flags |= IA_PRIMARY;
+      rem_node(&a->n);
+      add_head(&i->addrs, &a->n);
     }
-  res = (b != i->addr);
-  i->addr = b;
-  if (b)
-    {
-      b->flags |= IA_PRIMARY;
-      rem_node(&b->n);
-      add_head(&i->addrs, &b->n);
-    }
-  return res;
+
+  i->addr = a;
+  return 1;
 }
 
+void
+ifa_recalc_all_primary_addresses(void)
+{
+  struct iface *i;
+
+  WALK_LIST(i, iface_list)
+    {
+      if (ifa_recalc_primary(i))
+	if_change_flags(i, i->flags | IF_TMP_DOWN);
+    }
+}
+
+
 /**
  * ifa_update - update interface address
  * @a: new interface address
@@ -464,7 +478,7 @@ ifa_update(struct ifa *a)
   memcpy(b, a, sizeof(struct ifa));
   add_tail(&i->addrs, &b->n);
   b->flags = (i->flags & ~IA_FLAGS) | (a->flags & IA_FLAGS);
-  if ((!i->addr || i->addr->scope < b->scope) && ifa_recalc_primary(i))
+  if (ifa_recalc_primary(i))
     if_change_flags(i, i->flags | IF_TMP_DOWN);
   if (b->flags & IF_UP)
     ifa_notify_change(IF_CHANGE_CREATE | IF_CHANGE_UP, b);
diff --git a/nest/iface.h b/nest/iface.h
index f884dd90..af98a761 100644
--- a/nest/iface.h
+++ b/nest/iface.h
@@ -80,6 +80,7 @@ void if_end_partial_update(struct iface *);
 void if_feed_baby(struct proto *);
 struct iface *if_find_by_index(unsigned);
 struct iface *if_find_by_name(char *);
+void ifa_recalc_all_primary_addresses(void);
 
 /* The Neighbor Cache */
 
diff --git a/sysdep/unix/krt.Y b/sysdep/unix/krt.Y
index 24f2dd27..40f1af9f 100644
--- a/sysdep/unix/krt.Y
+++ b/sysdep/unix/krt.Y
@@ -82,7 +82,7 @@ kif_item:
       /* Scan time of 0 means scan on startup only */
       THIS_KIF->scan_time = $3;
    }
- | PRIMARY TEXT prefix_or_ipa {
+ | PRIMARY text_or_none prefix_or_ipa {
      struct kif_primary_item *kpi = cfg_alloc(sizeof (struct kif_primary_item));
      kpi->pattern = $2;
      kpi->prefix = $3.addr;
diff --git a/sysdep/unix/krt.c b/sysdep/unix/krt.c
index 6208f689..a60e7f91 100644
--- a/sysdep/unix/krt.c
+++ b/sysdep/unix/krt.c
@@ -151,6 +151,49 @@ kif_shutdown(struct proto *P)
   return PS_DOWN;
 }
 
+
+static inline int
+prefer_scope(struct ifa *a, struct ifa *b)
+{ return (a->scope > SCOPE_LINK) && (b->scope <= SCOPE_LINK); }
+
+static inline int
+prefer_addr(struct ifa *a, struct ifa *b)
+{ return ipa_compare(a->ip, b->ip) < 0; }
+
+static inline struct ifa *
+find_preferred_ifa(struct iface *i, ip_addr prefix, ip_addr mask)
+{
+  struct ifa *a, *b = NULL;
+
+  WALK_LIST(a, i->addrs)
+    {
+      if (!(a->flags & IA_SECONDARY) &&
+	  ipa_equal(ipa_and(a->ip, mask), prefix) &&
+	  (!b || prefer_scope(a, b) || prefer_addr(a, b)))
+	b = a;
+    }
+
+  return b;
+}
+
+struct ifa *
+kif_choose_primary(struct iface *i)
+{
+  struct kif_config *cf = (struct kif_config *) (kif_proto->p.cf);
+  struct kif_primary_item *it;
+  struct ifa *a;
+
+  WALK_LIST(it, cf->primary)
+    {
+      if (!it->pattern || patmatch(it->pattern, i->name))
+	if (a = find_preferred_ifa(i, it->prefix, ipa_mkmask(it->pxlen)))
+	  return a;
+    }
+
+  return find_preferred_ifa(i, IPA_NONE, IPA_NONE);
+}
+
+
 static int
 kif_reconfigure(struct proto *p, struct proto_config *new)
 {
@@ -159,6 +202,7 @@ kif_reconfigure(struct proto *p, struct proto_config *new)
 
   if (!kif_params_same(&o->iface, &n->iface))
     return 0;
+
   if (o->scan_time != n->scan_time)
     {
       tm_stop(kif_scan_timer);
@@ -166,6 +210,18 @@ kif_reconfigure(struct proto *p, struct proto_config *new)
       kif_scan(kif_scan_timer);
       tm_start(kif_scan_timer, n->scan_time);
     }
+
+  if (!EMPTY_LIST(o->primary) || !EMPTY_LIST(n->primary))
+    {
+      /* This is hack, we have to update a configuration
+       * to the new value just now, because it is used
+       * for recalculation of primary addresses.
+       */
+      p->cf = new;
+
+      ifa_recalc_all_primary_addresses();
+    }
+
   return 1;
 }