From: Stephen Hemminger <shemminger@vyatta•com>
To: Pavel Emelyanov <xemul@parallels•com>
Cc: Stephen Hemminger <shemminger@linux-foundation•org>,
Linux Netdev List <netdev@vger•kernel.org>
Subject: Re: [PATCH] iproute: Fix errno propagation from rtnl_talk
Date: Mon, 20 Aug 2012 12:55:22 -0700 [thread overview]
Message-ID: <20120820125522.2e5eb519@nehalam.linuxnetplumber.net> (raw)
In-Reply-To: <5031F088.1030404@parallels.com>
On Mon, 20 Aug 2012 12:08:40 +0400
Pavel Emelyanov <xemul@parallels•com> wrote:
> Callers of rtnl_talk check errno value for their needs. In particular, the addrs
> and routes restoring code validly reports success if the EEXISTS is in there.
>
> However, the errno value can be sometimes screwed up by the perror call. Thus
> we should only set it _after_ the message was emitted.
>
> Signed-off-by: Pavel Emelyanov <xemul@parallels•com>
>
> ---
>
> diff --git a/lib/libnetlink.c b/lib/libnetlink.c
> index 878911e..8e8c8b9 100644
> --- a/lib/libnetlink.c
> +++ b/lib/libnetlink.c
> @@ -360,13 +360,14 @@ int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
> if (l < sizeof(struct nlmsgerr)) {
> fprintf(stderr, "ERROR truncated\n");
> } else {
> - errno = -err->error;
> - if (errno == 0) {
> + if (!err->error) {
> if (answer)
> memcpy(answer, h, h->nlmsg_len);
> return 0;
> }
> - perror("RTNETLINK answers");
> +
> + fprintf(stderr, "RTNETLINK answers: %s\n", strerror(-err->error));
> + errno = -err->error;
> }
> return -1;
> }
Applied
prev parent reply other threads:[~2012-08-20 19:55 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-20 8:08 [PATCH] iproute: Fix errno propagation from rtnl_talk Pavel Emelyanov
2012-08-20 19:55 ` Stephen Hemminger [this message]
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