From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Fan Du <fan.du@windriver.com>
Cc: steffen.klassert@secunet.com, davem@davemloft.net,
netdev@vger.kernel.org, netfilter-devel@vger.kernel.org
Subject: Re: [PATCH net-next] ipcomp: Convert struct xt_ipcomp spis into 16bits
Date: Sat, 18 Jan 2014 13:24:37 +0100 [thread overview]
Message-ID: <20140118122437.GA4309@localhost> (raw)
In-Reply-To: <1390011374-21760-1-git-send-email-fan.du@windriver.com>
On Sat, Jan 18, 2014 at 10:16:14AM +0800, Fan Du wrote:
> 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 */
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?
> __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
>
next prev parent reply other threads:[~2014-01-18 12:24 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-18 2:16 [PATCH net-next] ipcomp: Convert struct xt_ipcomp spis into 16bits Fan Du
2014-01-18 12:24 ` Pablo Neira Ayuso [this message]
2014-01-20 1:55 ` Fan Du
2014-02-19 10:14 ` Pablo Neira Ayuso
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