Subject: Re: [PATCH v2] tipc: set sk_err correctly when connection fails

From: Paul Gortmaker <[email-masked]>
Date: Thu, 29 Aug 2013 11:03:10 -0400

On 13-08-28 03:29 AM, [email-masked] wrote:
> From: Erik Hugne <[email-masked]>
> 
> Should a connect fail, if the publication/server is unavailable or
> due to some other error, a positive value will be returned and errno
> is never set. If the application code checks for an explicit zero
> return from connect (success) or a negative return (failure), it
> will not catch the error and subsequent send() calls will fail as
> shown from the strace snippet below.
> 
> socket(0x1e /* PF_??? */, SOCK_SEQPACKET, 0) = 3
> connect(3, {sa_family=0x1e /* AF_??? */, sa_data="\2\1\322\4\0\0\322\4\0\0\0\0\0\0"}, 16) = 111
> sendto(3, "test", 4, 0, NULL, 0)        = -1 EPIPE (Broken pipe)
> 
> The reason for this behaviour is that TIPC wrongly inverts error
> codes set in sk_err.
> 
> Signed-off-by: Erik Hugne <[email-masked]>
> ---
> 
> [v2: add more details to commit message]

Thanks -- this now conveys the required triplet: 1) user visible symptom,
2) underlying technical cause, and 3) the why and how of the fix.

Paul.
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