Re: [Qemu-devel] [PATCH v2 3/4] sockets: add AF_VSOCK support

[Stefan Hajnoczi <stefanha@redhat.com>]

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On Mon, Oct 17, 2016 at 09:25:46AM -0500, Eric Blake wrote:
> On 10/16/2016 08:35 AM, Stefan Hajnoczi wrote:
> 
> >>> +
> >>> +    if (sscanf(str, "%32[^:]:%32[^,]%n", cid, port, &n) != 2) {
> >>
> >> This says stop at the first comma after the colon...
> >>
> >>> +        error_setg(errp, "error parsing address '%s'", str);
> >>> +        return NULL;
> >>> +    }
> >>> +    if (str[n] != '\0') {
> >>> +        error_setg(errp, "trailing characters in address '%s'", str);
> >>
> >> ...but this rejects a trailing comma.  Is a trailing comma possible base
> >> on how QemuOpts work? If so, do you need to handle it here?
> > 
> > Actually I just wanted to grab characters up until the end of string.
> > It wasn't clear from the sscanf(3) man page what the best way to do that
> > was, so I kept the comma which is also used in tcp addresses (because
> > they support additional comma-separated options).
> 
> %32s instead of %32[^,] should grab up to all 32 remaining characters in
> the string; your %n trick then ensures there is no garbage.  I guess
> it's still a question of whether we want to always treat a comma as
> trailing garbage.

No comma options are currently accepted.  Treating comma as garbage
seems okay.

Mike: Please change %32[^,] to %32s when merging.  Thanks!

Stefan

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