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* [conntrack-tools PATCH v2] conntrack: Fix CIDR to mask conversion on Big Endian
@ 2019-09-04  9:37 Phil Sutter
  2019-09-04  9:55 ` Pablo Neira Ayuso
  0 siblings, 1 reply; 2+ messages in thread
From: Phil Sutter @ 2019-09-04  9:37 UTC (permalink / raw)
  To: Pablo Neira Ayuso; +Cc: netfilter-devel, Florian Westphal

Code assumed host architecture to be Little Endian. Instead produce a
proper mask by pushing the set bits into most significant position and
apply htonl() on the result.

Fixes: 3f6a2e90936bb ("conntrack: add support for CIDR notation")
Signed-off-by: Phil Sutter <phil@nwl.cc>
---
Changes since v1:
- Simplify bitshift operation as per Florian's suggestion.
---
 src/conntrack.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/conntrack.c b/src/conntrack.c
index c980a13f33d2c..f65926b298ad3 100644
--- a/src/conntrack.c
+++ b/src/conntrack.c
@@ -2210,7 +2210,7 @@ nfct_build_netmask(uint32_t *dst, int b, int n)
 			dst[i] = 0xffffffff;
 			b -= 32;
 		} else if (b > 0) {
-			dst[i] = (1 << b) - 1;
+			dst[i] = htonl(~0u << (32 - b));
 			b = 0;
 		} else {
 			dst[i] = 0;
-- 
2.22.0


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [conntrack-tools PATCH v2] conntrack: Fix CIDR to mask conversion on Big Endian
  2019-09-04  9:37 [conntrack-tools PATCH v2] conntrack: Fix CIDR to mask conversion on Big Endian Phil Sutter
@ 2019-09-04  9:55 ` Pablo Neira Ayuso
  0 siblings, 0 replies; 2+ messages in thread
From: Pablo Neira Ayuso @ 2019-09-04  9:55 UTC (permalink / raw)
  To: Phil Sutter; +Cc: netfilter-devel, Florian Westphal

On Wed, Sep 04, 2019 at 11:37:32AM +0200, Phil Sutter wrote:
> Code assumed host architecture to be Little Endian. Instead produce a
> proper mask by pushing the set bits into most significant position and
> apply htonl() on the result.
> 
> Fixes: 3f6a2e90936bb ("conntrack: add support for CIDR notation")
> Signed-off-by: Phil Sutter <phil@nwl.cc>

Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2019-09-04  9:37 [conntrack-tools PATCH v2] conntrack: Fix CIDR to mask conversion on Big Endian Phil Sutter
2019-09-04  9:55 ` Pablo Neira Ayuso

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