Re: [PATCH net-next] ipcomp: Convert struct xt_ipcomp spis into 16bits
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2014-01-18 12:24:53
Also in:
netfilter-devel
On Sat, Jan 18, 2014 at 10:16:14AM +0800, Fan Du wrote:
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sparse warnings: (new ones prefixed by >>)quoted
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net/netfilter/xt_ipcomp.c:63:26: sparse: restricted __be16 degrades to integer net/netfilter/xt_ipcomp.c:63:26: sparse: cast to restricted __be32Fix this by using 16bits long spi, as IPcomp CPI is only valid for 16bits. Signed-off-by: Fan Du <redacted> --- 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 */
This changes the binary interface so it break userspace (iptables needs to be recompiled), we're still in time to make such change as this is net-next stuff, but what I understand from the patch description is that this aims to fix a sparse warning, which is a bit of intrusive change. Didn't you find any way to fix this without change the layout of xt_ipcomp?
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__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