Re: [libvirt] Libvirt config converter can't handle file not ending with new line

On Tue, 7 Nov 2017 12:20:05 +0000 Wei Liu <wei.liu2(a)citrix.com&gt; wrote: > On Mon, Nov 06, 2017 at 09:41:01PM -0700, Jim Fehlig wrote: >> On 10/30/2017 06:17 AM, Wei Liu wrote: >>> Hi Jim >>> >>> I discover a problem when using xen_xl converter. When the file in >>> question doesn't end with a new line, I get the following error: >>> >>> error: configuration file syntax error: memory conf:53: expecting a value >> >> I'm not able to reproduce this issue. The libvirt.git tree I tried was a bit >> dated, but even after updating to latest master I can't reproduce. >> >>> After digging a bit (but haven't read libvirt code), it appears that the >>> file didn't end with a new line. >> >> I tried several files without ending new lines, going both directions >> (domxml-to-native and domxml-from-native), but didn't see the mentioned >> error. Perhaps your config is revealing another bug which is being >> improperly reported. Can you provide an example of the problematic config? >> > > I tried to get the exact file that caused the problem but it is already > destroyed by osstest. > > A similar file: > > http://logs.test-lab.xenproject.org/osstest/logs/115436/test-amd64-amd64-... > > If you hexdump -C it, you can see the last character is 0a. Remove it and > feed the file into the converter. > Wei. The phenonomem you point out is indeed weird. And my first response is that this is a bug parsing the cfg input. I did little explore and think that src/util/virconf.c (virConfParseLong(), virConfParseValue()) should be reworked as pointed out in below context diffs. <wtenhave@nina:140> git diff diff --git a/src/util/virconf.c b/src/util/virconf.c index 39c2bd917..bc8e57ec3 100644 --- a/src/util/virconf.c +++ b/src/util/virconf.c @@ -352,7 +352,7 @@ virConfParseLong(virConfParserCtxtPtr ctxt, long long *val) } else if (CUR == '+') { NEXT; } - if ((ctxt->cur >= ctxt->end) || (!c_isdigit(CUR))) { + if ((ctxt->cur > ctxt->end) || (!c_isdigit(CUR))) { virConfError(ctxt, VIR_ERR_CONF_SYNTAX, _("unterminated number")); return -1; } @@ -456,7 +456,7 @@ virConfParseValue(virConfParserCtxtPtr ctxt) long long l = 0; SKIP_BLANKS; - if (ctxt->cur >= ctxt->end) { + if (ctxt->cur > ctxt->end) { virConfError(ctxt, VIR_ERR_CONF_SYNTAX, _("expecting a value")); return NULL; } I did not go beyond this yet.