WIP: platform: properly handle same routes in platform cacheth/platform-route-identity

From kernels point of view, you can add a new routes as long as
there is no existing route that is exactly identical. That effectively
means, that every field of the route is part of the ID.

Currently, we handle that wrong, thus when kernel notifies platform
about two such routes, we would wrongly merge them together.
For example:

    ip link add dev0 type dummy
    ip link add dev1 type dummy
    ip link set dev0 up
    ip link set dev1 up
    ip addr add 192.168.200.4/24 dev dev0
    ip addr add 192.168.201.4/24 dev dev1

    ip route add    10.132.5.0/24 dev dev0
    ip route append 10.132.5.0/24 via 192.168.212.1 dev dev0
    ip route append 10.132.5.0/24 via 192.168.212.1 dev dev0 proto 5
    ip route show dev dev0

    ip route add    1:2:3:4:5::/64 via fe80::1:a dev dev0
    ip route append 1:2:3:4:5::/64 via fe80::1:b dev dev0
    ip route append 1:2:3:4:5::/64 via fe80::1:b dev dev0 proto 5
    ip -6 route show dev dev0

Note the difference here are the netlink flags:
  `ip route append`  (NLM_F_CREATE|NLM_F_APPEND)
  `ip route prepend` (NLM_F_CREATE)
  `ip route add`     (NLM_F_CREATE|NLM_F_EXCL)
  `ip route change`  (NLM_F_REPLACE)
  `ip route replace` (NLM_F_CREATE|NLM_F_REPLACE)

Extend platform to consider every property of a route to be part
of the ID. Also update the API like route_add(), route_get() and
route_delete() to accept full route structures as arguments.
For delete, that means you can only delete a route that you know
about. But that isn't really actually a problem.

1 files changed, 62 insertions, 38 deletions

diff --git a/src/platform/nm-platform.h b/src/platform/nm-platform.h
index ae12aa8e95..28d7b39689 100644
--- a/src/platform/nm-platform.h
+++ b/src/platform/nm-platform.h
@@ -338,13 +338,20 @@ struct _NMPlatformIP4Route {
 	in_addr_t network;
 	in_addr_t gateway;
 
-	/* The bitwise inverse of the route scope. It is inverted so that the
-	 * default value (RT_SCOPE_NOWHERE) is nul. */
-	guint8 scope_inv;
-
 	/* RTA_PREFSRC/rtnl_route_get_pref_src(). A value of zero means that
 	 * no pref-src is set.  */
 	in_addr_t pref_src;
+
+	/* The route scope rtm_scope.
+	 *
+	 * Note, that for IPv4, the scope is part of the ID for a route.
+	 * That means, when we receive a route from kernel, we set rt_scope
+	 * and rt_scope_is_set=1 to indicate that the scope is fully determined.
+	 *
+	 * When adding a route, we allow the user to autodetect the scope based
+	 * on the gateway. That is controlled by leaving rt_scope_is_set=0. */
+	guint8 rt_scope;
+	bool rt_scope_is_set:1;
 };
 
 struct _NMPlatformIP6Route {
@@ -372,9 +379,8 @@ typedef struct {
 	int (*route_cmp) (const NMPlatformIPXRoute *a, const NMPlatformIPXRoute *b);
 	const char *(*route_to_string) (const NMPlatformIPXRoute *route, char *buf, gsize len);
 	GArray *(*route_get_all) (NMPlatform *self, int ifindex, NMPlatformGetRouteFlags flags);
-	gboolean (*route_add) (NMPlatform *self, int ifindex, const NMPlatformIPXRoute *route, gint64 metric);
-	gboolean (*route_delete) (NMPlatform *self, int ifindex, const NMPlatformIPXRoute *route);
-	gboolean (*route_delete_default) (NMPlatform *self, int ifindex, guint32 metric);
+	gboolean (*route_add) (NMPlatform *self, const NMPlatformIPXRoute *route, int ifindex, gint64 metric);
+	gboolean (*route_delete) (NMPlatform *self, const NMPlatformIPXRoute *route);
 	guint32 (*metric_normalize) (guint32 metric);
 } NMPlatformVTableRoute;
 
@@ -630,16 +636,12 @@ typedef struct {
 
 	GArray * (*ip4_route_get_all) (NMPlatform *, int ifindex, NMPlatformGetRouteFlags flags);
 	GArray * (*ip6_route_get_all) (NMPlatform *, int ifindex, NMPlatformGetRouteFlags flags);
-	gboolean (*ip4_route_add) (NMPlatform *, int ifindex, NMIPConfigSource source,
-	                           in_addr_t network, guint8 plen, in_addr_t gateway,
-	                           in_addr_t pref_src, guint32 metric, guint32 mss);
-	gboolean (*ip6_route_add) (NMPlatform *, int ifindex, NMIPConfigSource source,
-	                           struct in6_addr network, guint8 plen, struct in6_addr gateway,
-	                           guint32 metric, guint32 mss);
-	gboolean (*ip4_route_delete) (NMPlatform *, int ifindex, in_addr_t network, guint8 plen, guint32 metric);
-	gboolean (*ip6_route_delete) (NMPlatform *, int ifindex, struct in6_addr network, guint8 plen, guint32 metric);
-	const NMPlatformIP4Route *(*ip4_route_get) (NMPlatform *, int ifindex, in_addr_t network, guint8 plen, guint32 metric);
-	const NMPlatformIP6Route *(*ip6_route_get) (NMPlatform *, int ifindex, struct in6_addr network, guint8 plen, guint32 metric);
+	gboolean (*ip4_route_add) (NMPlatform *, const NMPlatformIP4Route *route);
+	gboolean (*ip6_route_add) (NMPlatform *, const NMPlatformIP6Route *route);
+	gboolean (*ip4_route_delete) (NMPlatform *, const NMPlatformIP4Route *route);
+	gboolean (*ip6_route_delete) (NMPlatform *, const NMPlatformIP6Route *route);
+	const NMPlatformIP4Route *(*ip4_route_get) (NMPlatform *, const NMPlatformIP4Route *route);
+	const NMPlatformIP6Route *(*ip6_route_get) (NMPlatform *, const NMPlatformIP6Route *route);
 
 	gboolean (*check_support_kernel_extended_ifa_flags) (NMPlatform *);
 	gboolean (*check_support_user_ipv6ll) (NMPlatform *);
@@ -676,23 +678,37 @@ NMPlatform *nm_platform_try_get (void);
 
 /******************************************************************/
 
-/**
- * nm_platform_route_scope_inv:
- * @scope: the route scope, either its original value, or its inverse.
- *
- * This function is useful, because the constants such as RT_SCOPE_NOWHERE
- * are 'int', so ~scope also gives an 'int'. This function gets the type
- * casts to guint8 right.
- *
- * Returns: the bitwise inverse of the route scope.
- * */
-#define nm_platform_route_scope_inv _nm_platform_uint8_inv
 static inline guint8
 _nm_platform_uint8_inv (guint8 scope)
 {
 	return (guint8) ~scope;
 }
 
+static inline guint8
+nm_platform_route_scope_for_ip4_gateway (guint32 gateway)
+{
+	return gateway
+	       ? 0   /* RT_SCOPE_UNIVERSE */
+	       : 253 /* RT_SCOPE_LINK */;
+}
+
+static inline guint8
+nm_platform_route_scope_for_ip6_gateway (const struct in6_addr *gateway)
+{
+	return gateway && !IN6_IS_ADDR_UNSPECIFIED (gateway)
+	       ? 0   /* RT_SCOPE_UNIVERSE */
+	       : 253 /* RT_SCOPE_LINK */;
+}
+
+static inline guint8
+nm_platform_route_scope_from_ip4_route (const NMPlatformIP4Route *route)
+{
+	nm_assert (route);
+	return route->rt_scope_is_set
+	       ? route->rt_scope
+	       : nm_platform_route_scope_for_ip4_gateway (route->gateway);
+}
+
 NMPNetns *nm_platform_netns_get (NMPlatform *self);
 gboolean nm_platform_netns_push (NMPlatform *platform, NMPNetns **netns);
 
@@ -907,18 +923,14 @@ gboolean nm_platform_ip4_address_sync (NMPlatform *self, int ifindex, const GArr
 gboolean nm_platform_ip6_address_sync (NMPlatform *self, int ifindex, const GArray *known_addresses, gboolean keep_link_local);
 gboolean nm_platform_address_flush (NMPlatform *self, int ifindex);
 
-const NMPlatformIP4Route *nm_platform_ip4_route_get (NMPlatform *self, int ifindex, in_addr_t network, guint8 plen, guint32 metric);
-const NMPlatformIP6Route *nm_platform_ip6_route_get (NMPlatform *self, int ifindex, struct in6_addr network, guint8 plen, guint32 metric);
+const NMPlatformIP4Route *nm_platform_ip4_route_get (NMPlatform *self, const NMPlatformIP4Route *route);
+const NMPlatformIP6Route *nm_platform_ip6_route_get (NMPlatform *self, const NMPlatformIP6Route *route);
 GArray *nm_platform_ip4_route_get_all (NMPlatform *self, int ifindex, NMPlatformGetRouteFlags flags);
 GArray *nm_platform_ip6_route_get_all (NMPlatform *self, int ifindex, NMPlatformGetRouteFlags flags);
-gboolean nm_platform_ip4_route_add (NMPlatform *self, int ifindex, NMIPConfigSource source,
-                                    in_addr_t network, guint8 plen, in_addr_t gateway,
-                                    in_addr_t pref_src, guint32 metric, guint32 mss);
-gboolean nm_platform_ip6_route_add (NMPlatform *self, int ifindex, NMIPConfigSource source,
-                                    struct in6_addr network, guint8 plen, struct in6_addr gateway,
-                                    guint32 metric, guint32 mss);
-gboolean nm_platform_ip4_route_delete (NMPlatform *self, int ifindex, in_addr_t network, guint8 plen, guint32 metric);
-gboolean nm_platform_ip6_route_delete (NMPlatform *self, int ifindex, struct in6_addr network, guint8 plen, guint32 metric);
+gboolean nm_platform_ip4_route_add (NMPlatform *self, const NMPlatformIP4Route *route);
+gboolean nm_platform_ip6_route_add (NMPlatform *self, const NMPlatformIP6Route *route);
+gboolean nm_platform_ip4_route_delete (NMPlatform *self, const NMPlatformIP4Route *route);
+gboolean nm_platform_ip6_route_delete (NMPlatform *self, const NMPlatformIP6Route *route);
 
 const char *nm_platform_link_to_string (const NMPlatformLink *link, char *buf, gsize len);
 const char *nm_platform_lnk_gre_to_string (const NMPlatformLnkGre *lnk, char *buf, gsize len);
@@ -954,6 +966,18 @@ int nm_platform_ip6_address_cmp (const NMPlatformIP6Address *a, const NMPlatform
 int nm_platform_ip4_route_cmp (const NMPlatformIP4Route *a, const NMPlatformIP4Route *b);
 int nm_platform_ip6_route_cmp (const NMPlatformIP6Route *a, const NMPlatformIP6Route *b);
 
+typedef enum {
+	NM_PLATFORM_IP_ROUTE_ID_TYPE_ID,
+	NM_PLATFORM_IP_ROUTE_ID_TYPE_ALL,
+} NMPlatformIPRouteIdType;
+
+int nm_platform_ip4_route_cmp_full (const NMPlatformIP4Route *a, const NMPlatformIP4Route *b, NMPlatformIPRouteIdType id_type);
+int nm_platform_ip6_route_cmp_full (const NMPlatformIP6Route *a, const NMPlatformIP6Route *b, NMPlatformIPRouteIdType id_type);
+guint nm_platform_ip4_route_hash_full (const NMPlatformIP4Route *a, NMPlatformIPRouteIdType id_type);
+guint nm_platform_ip6_route_hash_full (const NMPlatformIP6Route *a, NMPlatformIPRouteIdType id_type);
+NMPlatformIP4Route *nm_platform_ip4_route_normalize (NMPlatformIP4Route *dst, const NMPlatformIP4Route *src, NMPlatformIPRouteIdType id_type);
+NMPlatformIP6Route *nm_platform_ip6_route_normalize (NMPlatformIP6Route *dst, const NMPlatformIP6Route *src, NMPlatformIPRouteIdType id_type);
+
 gboolean nm_platform_check_support_kernel_extended_ifa_flags (NMPlatform *self);
 gboolean nm_platform_check_support_user_ipv6ll (NMPlatform *self);