Merge branch 'net-Add-route-offload-indication'

Ido Schimmel says:

====================
net: Add route offload indication

This patch set adds offload indication to IPv4 and IPv6 routes. So far
offload indication was only available for the nexthop via
'RTNH_F_OFFLOAD', which is problematic as a nexthop is usually shared
between multiple routes.

Based on feedback from Roopa and David on the RFC [1], the indication is
split to 'offload' and 'trap'. This is done because not all the routes
present in hardware actually offload traffic from the kernel. For
example, host routes merely trap packets to the kernel. The two flags
are dumped to user space via the 'rtm_flags' field in the ancillary
header of the rtnetlink message.

In addition, the patch set uses the new flags in order to test the FIB
offload API by adding a dummy FIB offload implementation to netdevsim.
The new tests are added to a shared library and can be therefore shared
between different drivers.

Patches #1-#3 add offload indication to IPv4 routes.
Patches #4 adds offload indication to IPv6 routes.
Patches #5-#6 add support for the offload indication in mlxsw.
Patch #7 adds dummy FIB offload implementation in netdevsim.
Patches #8-#10 add selftests.

v2 (feedback from David Ahern):
* Patch #2: Name last argument of fib_dump_info()
* Patch #2: Move 'struct fib_rt_info' to include/net/ip_fib.h so that it
  could later be passed to fib_alias_hw_flags_set()
* Patch #3: Make use of 'struct fib_rt_info' in fib_alias_hw_flags_set()
* Patch #6: Convert to new fib_alias_hw_flags_set() interface
* Patch #7: Convert to new fib_alias_hw_flags_set() interface

[1] https://patchwork.ozlabs.org/cover/1170530/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 25 insertions, 1 deletions

diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index b579faea41e9..fd60a8ac02ee 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -192,7 +192,9 @@ struct fib6_info {
 					dst_nopolicy:1,
 					dst_host:1,
 					fib6_destroying:1,
-					unused:3;
+					offload:1,
+					trap:1,
+					unused:1;
 
 	struct rcu_head			rcu;
 	struct nexthop			*nh;
@@ -329,6 +331,13 @@ static inline void fib6_info_release(struct fib6_info *f6i)
 		call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
 }
 
+static inline void fib6_info_hw_flags_set(struct fib6_info *f6i, bool offload,
+					  bool trap)
+{
+	f6i->offload = offload;
+	f6i->trap = trap;
+}
+
 enum fib6_walk_state {
 #ifdef CONFIG_IPV6_SUBTREES
 	FWS_S,
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index b9cba41c6d4f..6a1ae49809de 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -204,6 +204,18 @@ __be32 fib_result_prefsrc(struct net *net, struct fib_result *res);
 #define FIB_RES_DEV(res)	(FIB_RES_NHC(res)->nhc_dev)
 #define FIB_RES_OIF(res)	(FIB_RES_NHC(res)->nhc_oif)
 
+struct fib_rt_info {
+	struct fib_info		*fi;
+	u32			tb_id;
+	__be32			dst;
+	int			dst_len;
+	u8			tos;
+	u8			type;
+	u8			offload:1,
+				trap:1,
+				unused:6;
+};
+
 struct fib_entry_notifier_info {
 	struct fib_notifier_info info; /* must be first */
 	u32 dst;
@@ -464,6 +476,7 @@ int fib_nh_common_init(struct fib_nh_common *nhc, struct nlattr *fc_encap,
 void fib_nh_common_release(struct fib_nh_common *nhc);
 
 /* Exported by fib_trie.c */
+void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri);
 void fib_trie_init(void);
 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
 
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 1418a8362bb7..cd43321d20dd 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -309,6 +309,8 @@ enum rt_scope_t {
 #define RTM_F_PREFIX		0x800	/* Prefix addresses		*/
 #define RTM_F_LOOKUP_TABLE	0x1000	/* set rtm_table to FIB lookup result */
 #define RTM_F_FIB_MATCH	        0x2000	/* return full fib lookup match */
+#define RTM_F_OFFLOAD		0x4000	/* route is offloaded */
+#define RTM_F_TRAP		0x8000	/* route is trapping packets */
 
 /* Reserved table identifiers */