[PATCH net-next] ipcomp: Convert struct xt_ipcomp spis into 16bits

[Fan Du <fan.du@windriver.com>]

sparse warnings: (new ones prefixed by >>)

>> >> net/netfilter/xt_ipcomp.c:63:26: sparse: restricted __be16 degrades to integer
>> >> net/netfilter/xt_ipcomp.c:63:26: sparse: cast to restricted __be32

Fix this by using 16bits long spi, as IPcomp CPI is only valid for 16bits.

Signed-off-by: Fan Du <fan.du@windriver.com>
---
 include/uapi/linux/netfilter/xt_ipcomp.h |    2 +-
 net/netfilter/xt_ipcomp.c                |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/uapi/linux/netfilter/xt_ipcomp.h b/include/uapi/linux/netfilter/xt_ipcomp.h
index 45c7e40..ca82ebb 100644
--- a/include/uapi/linux/netfilter/xt_ipcomp.h
+++ b/include/uapi/linux/netfilter/xt_ipcomp.h
@@ -4,7 +4,7 @@
 #include <linux/types.h>
 
 struct xt_ipcomp {
-	__u32 spis[2];	/* Security Parameter Index */
+	__u16 spis[2];	/* Security Parameter Index */
 	__u8 invflags;	/* Inverse flags */
 	__u8 hdrres;	/* Test of the Reserved Filed */
 };
diff --git a/net/netfilter/xt_ipcomp.c b/net/netfilter/xt_ipcomp.c
index a4c7561..5542cb2 100644
--- a/net/netfilter/xt_ipcomp.c
+++ b/net/netfilter/xt_ipcomp.c
@@ -29,7 +29,7 @@ MODULE_DESCRIPTION("Xtables: IPv4/6 IPsec-IPComp SPI match");
 
 /* Returns 1 if the spi is matched by the range, 0 otherwise */
 static inline bool
-spi_match(u_int32_t min, u_int32_t max, u_int32_t spi, bool invert)
+spi_match(u_int16_t min, u_int16_t max, u_int16_t spi, bool invert)
 {
 	bool r;
 	pr_debug("spi_match:%c 0x%x <= 0x%x <= 0x%x\n",
@@ -60,7 +60,7 @@ static bool comp_mt(const struct sk_buff *skb, struct xt_action_param *par)
 	}
 
 	return spi_match(compinfo->spis[0], compinfo->spis[1],
-			 ntohl(chdr->cpi << 16),
+			 ntohl(chdr->cpi),
 			 !!(compinfo->invflags & XT_IPCOMP_INV_SPI));
 }
 
-- 
1.7.9.5