[libvirt] [PATCH] network_conf: Forbid commas in DNS TXT

[Michal Privoznik]

https://bugzilla.redhat.com/show_bug.cgi?id=1151942

While the restriction doesn't have origin in any RFC, it matters
to us while constructing the dnsmasq config file (or command line
previously). For better picture, this is how the corresponding
part of network XML look like:

  <dns>
    <forwarder addr='8.8.4.4'/>
    <txt name='example' value='example value'/>
  </dns>

And this is how the config file looks like then:

  server=8.8.4.4
  txt-record=example,example value

Now we can see why there can't be any commas in the TXT name.
They are used by dnsmasq to separate @name and @value.

Funny, we have it in the documentation, but the code (which was
pushed back in 2011) didn't reflect that.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 src/conf/network_conf.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c
index dce3360..3d8bf05 100644
--- a/src/conf/network_conf.c
+++ b/src/conf/network_conf.c
@@ -1057,15 +1057,17 @@ virNetworkDNSTxtDefParseXML(const char *networkName,
                             virNetworkDNSTxtDefPtr def,
                             bool partialOkay)
 {
+    const char *bad = " ,";
+
     if (!(def->name = virXMLPropString(node, "name"))) {
         virReportError(VIR_ERR_XML_DETAIL,
                        _("missing required name attribute in DNS TXT record "
                          "of network %s"), networkName);
         goto error;
     }
-    if (strchr(def->name, ' ') != NULL) {
+    if (strcspn(def->name, bad) != strlen(def->name)) {
         virReportError(VIR_ERR_XML_DETAIL,
-                       _("prohibited space character in DNS TXT record "
+                       _("prohibited character in DNS TXT record "
                          "name '%s' of network %s"), def->name, networkName);
         goto error;
     }
-- 
2.0.5