Re: [PATCH] scpt: Allow struct sctp_event_subscribe to grow without breaking binaries

[David Miller <davem@davemloft.net>]

From: Vladislav Yasevich <vladislav.yasevich@hp.com>
Date: Wed, 04 Apr 2012 09:52:04 -0400

> On 04/04/2012 04:17 AM, Thomas Graf wrote:
>> getsockopt(..., SCTP_EVENTS, ...) performs a length check and returns
>> an error if the user provides less bytes than the size of struct
>> sctp_event_subscribe.
>> 
>> Struct sctp_event_subscribe needs to be extended by an u8 for every
>> new event or notification type that is added.
>> 
>> This obviously makes getsockopt fail for binaries that are compiled
>> against an older versions of <net/sctp/user.h> which do not contain
>> all event types.
>> 
>> This patch changes getsockopt behaviour to no longer return an error
>> if not enough bytes are being provided by the user. Instead, it
>> returns as much of sctp_event_subscribe as fits into the provided buffer.
>> 
>> This leads to the new behavior that users see what they have been aware
>> of at compile time.
>> 
>> The setsockopt(..., SCTP_EVENTS, ...) API is already behaving like this.
>> 
>> Signed-off-by: Thomas Graf <tgraf@suug.ch>
> 
> Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com>

Applied, but I had to fix the Subject to read "sctp: " not "scpt: " :-)