From: Josh Hunt <johunt@akamai•com>
To: Sergei Shtylyov <sergei.shtylyov@cogentembedded•com>,
davem@davemloft•net
Cc: netdev@vger•kernel.org, tom@herbertland•com
Subject: Re: [PATCH v2] ipv6: Fix protocol resubmission
Date: Fri, 29 May 2015 16:43:31 -0500 [thread overview]
Message-ID: <5568DD83.8020600@akamai.com> (raw)
In-Reply-To: <5568CBCC.1080503@cogentembedded.com>
On 05/29/2015 03:27 PM, Sergei Shtylyov wrote:
> Hello.
>
> On 05/29/2015 11:04 PM, Josh Hunt wrote:
>
>> I came across this problem while trying to use UDP encapsulation with
>> IPv6. The
>> change below fixes that, but it was not immediately apparent if there
>> are any
>> other protocols relying on this broken behavior. FWIW the behavior
>> below now
>> matches IPv4.
>
>> Josh
>
> Need "Signed-off-by:" line insted of this.
>
>> v2: Actually sets nexthdr so we can use it ;)
>
> Normally goes after ---, not before.
>
>> ---
>
>> UDP encapsulation is broken on IPv6 because it expects when it returns
>> a negative
>> value that the packet will be resubmitted to the stack with the
>> handler corresponding
>> to the return value. The check currently looks for return values > 0
>> and then resubmits.
>
>> This patch fixes that check and also moves the resubmit label to take
>> advantage of
>> the return code identifying the next protocol we want to process.
>
>> Signed-off-by: Josh Hunt <johunt@akamai•com>
>> ---
>> net/ipv6/ip6_input.c | 7 ++++---
>> 1 file changed, 4 insertions(+), 3 deletions(-)
>
>> diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
>> index f2e464e..e16c289 100644
>> --- a/net/ipv6/ip6_input.c
>> +++ b/net/ipv6/ip6_input.c
> [...]
>> @@ -246,9 +246,10 @@ resubmit:
>> goto discard;
>>
>> ret = ipprot->handler(skb);
>> - if (ret > 0)
>> + if (ret < 0) {
>> + nexthdr = -ret;
>> goto resubmit;
>> - else if (ret == 0)
>> + } else if (ret == 0)
>> IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
>
> The CodingStyle dictates that all branches must have {} if at least
> one has them.
Thanks Sergei, I appreciate the review. I will make these changes in a
v3 after I get feedback this is the correct fix for the problem.
Josh
next prev parent reply other threads:[~2015-05-29 21:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-29 20:04 [PATCH v2] ipv6: Fix protocol resubmission Josh Hunt
2015-05-29 20:27 ` Sergei Shtylyov
2015-05-29 21:43 ` Josh Hunt [this message]
2015-05-29 21:48 ` Tom Herbert
2015-05-30 2:37 ` Josh Hunt
2015-06-02 14:32 ` Josh Hunt
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