From 41874e85d6edda0cebdc84cb279c8de5cf88ba38 Mon Sep 17 00:00:00 2001
From: "Andrey V. Elsukov" <ae@FreeBSD.org>
Date: Thu, 11 Sep 2014 12:33:37 +0000
Subject: [PATCH] Introduce new scope related functions.

* new macro to remove magic number - IPV6_ADDR_SCOPES_COUNT;
* sa6_checkzone() - this function checks sockaddr_in6 structure
  for correctness of sin6_scope_id. It also can fill correct
  value sometimes.
* in6_getscopezone() - this function returns scope zone id for
  specified interface and scope.
* in6_getlinkifnet() - this function returns struct ifnet for
  corresponding zone id of link-local scope.

Obtained from:	Yandex LLC
Sponsored by:	Yandex LLC
---
 sys/netinet6/scope6.c     | 74 +++++++++++++++++++++++++++++++++++++++
 sys/netinet6/scope6_var.h |  6 +++-
 2 files changed, 79 insertions(+), 1 deletion(-)

diff --git a/sys/netinet6/scope6.c b/sys/netinet6/scope6.c
index 8139dcfc0da..c0eb0ca3a71 100644
--- a/sys/netinet6/scope6.c
+++ b/sys/netinet6/scope6.c
@@ -467,3 +467,77 @@ in6_getscope(struct in6_addr *in6)
 
 	return (0);
 }
+
+/*
+ * Return pointer to ifnet structure, corresponding to the zone id of
+ * link-local scope.
+ */
+struct ifnet*
+in6_getlinkifnet(uint32_t zoneid)
+{
+
+	return (ifnet_byindex((u_short)zoneid));
+}
+
+/*
+ * Return zone id for the specified scope.
+ */
+uint32_t
+in6_getscopezone(const struct ifnet *ifp, int scope)
+{
+
+	if (scope == IPV6_ADDR_SCOPE_INTFACELOCAL ||
+	    scope == IPV6_ADDR_SCOPE_LINKLOCAL)
+		return (ifp->if_index);
+	if (scope >= 0 && scope < IPV6_ADDR_SCOPES_COUNT)
+		return (SID(ifp)->s6id_list[scope]);
+	return (0);
+}
+
+/*
+ * This function is for checking sockaddr_in6 structure passed
+ * from the application level (usually).
+ *
+ * sin6_scope_id should be set for link-local unicast, link-local and
+ * interface-local  multicast addresses.
+ *
+ * If it is zero, then look into default zone ids. If default zone id is
+ * not set or disabled, then return error.
+ */
+int
+sa6_checkzone(struct sockaddr_in6 *sa6)
+{
+	int scope;
+
+	scope = in6_addrscope(&sa6->sin6_addr);
+	if (scope == IPV6_ADDR_SCOPE_GLOBAL)
+		return (sa6->sin6_scope_id ? EINVAL: 0);
+	if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr) &&
+	    scope != IPV6_ADDR_SCOPE_LINKLOCAL &&
+	    scope != IPV6_ADDR_SCOPE_INTFACELOCAL) {
+		if (sa6->sin6_scope_id == 0 && V_ip6_use_defzone != 0)
+			sa6->sin6_scope_id = V_sid_default.s6id_list[scope];
+		return (0);
+	}
+	/*
+	 * Since ::1 address always configured on the lo0, we can
+	 * automatically set its zone id, when it is not specified.
+	 * Return error, when specified zone id doesn't match with
+	 * actual value.
+	 */
+	if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr)) {
+		if (sa6->sin6_scope_id == 0)
+			sa6->sin6_scope_id = in6_getscopezone(V_loif, scope);
+		else if (sa6->sin6_scope_id != in6_getscopezone(V_loif, scope))
+			return (EADDRNOTAVAIL);
+	}
+	/* XXX: we can validate sin6_scope_id here */
+	if (sa6->sin6_scope_id != 0)
+		return (0);
+	if (V_ip6_use_defzone != 0)
+		sa6->sin6_scope_id = V_sid_default.s6id_list[scope];
+	/* Return error if we can't determine zone id */
+	return (sa6->sin6_scope_id ? 0: EADDRNOTAVAIL);
+}
+
+
diff --git a/sys/netinet6/scope6_var.h b/sys/netinet6/scope6_var.h
index 3398bbe6bd0..8a4b6fcf775 100644
--- a/sys/netinet6/scope6_var.h
+++ b/sys/netinet6/scope6_var.h
@@ -36,12 +36,13 @@
 #ifdef _KERNEL
 #include <net/vnet.h>
 
+#define	IPV6_ADDR_SCOPES_COUNT	16
 struct scope6_id {
 	/*
 	 * 16 is correspondent to 4bit multicast scope field.
 	 * i.e. from node-local to global with some reserved/unassigned types.
 	 */
-	u_int32_t s6id_list[16];
+	uint32_t s6id_list[IPV6_ADDR_SCOPES_COUNT];
 };
 
 VNET_DECLARE(int, deembed_scopeid);
@@ -56,9 +57,12 @@ int	scope6_get_default(struct scope6_id *);
 u_int32_t scope6_addr2default(struct in6_addr *);
 int	sa6_embedscope(struct sockaddr_in6 *, int);
 int	sa6_recoverscope(struct sockaddr_in6 *);
+int	sa6_checkzone(struct sockaddr_in6 *);
 int	in6_setscope(struct in6_addr *, struct ifnet *, u_int32_t *);
 int	in6_clearscope(struct in6_addr *);
 uint16_t in6_getscope(struct in6_addr *);
+uint32_t in6_getscopezone(const struct ifnet *, int);
+struct ifnet* in6_getlinkifnet(uint32_t);
 #endif /* _KERNEL */
 
 #endif /* _NETINET6_SCOPE6_VAR_H_ */