Improve error reporting when parsing dhcp info for virtual networks

This is partially in response to

  https://bugzilla.redhat.com/show_bug.cgi?id=653300

The crash in that report was coincidentally fixed when we switched
from using inet_pton() to using virSocketParseAddr(), but the absence
of an ip address in a dhcp static host definition was still silently
ignored (and that entry discarded from the saved XML). This patch
turns that into a logged failure; likewise if the entry has neither a
mac address nor a name attribute (the entry is useless without at
least one of those, plus an ip address).

Since the network name is now pulled into this function in order for
those error logs to be more informative, the other error messages in
the function have also been changed to take advantage.

src/conf/network_conf.c

@@ -295,7 +295,8 @@ int virNetworkIpDefNetmask(const virNetworkIpDefPtr def,
 
 
 static int
-virNetworkDHCPRangeDefParseXML(virNetworkIpDefPtr def,
+virNetworkDHCPRangeDefParseXML(const char *networkName,
+                               virNetworkIpDefPtr def,
                                xmlNodePtr node)
 {
 
@@ -333,8 +334,8 @@ virNetworkDHCPRangeDefParseXML(virNetworkIpDefPtr def,
             range = virSocketGetRange(&saddr, &eaddr);
             if (range < 0) {
                 virNetworkReportError(VIR_ERR_XML_ERROR,
-                                      _("dhcp range '%s' to '%s' invalid"),
-                                      start, end);
+                                      _("Invalid dhcp range '%s' to '%s' in network '%s'"),
+                                      start, end, networkName);
                 VIR_FREE(start);
                 VIR_FREE(end);
                 return -1;
@@ -359,33 +360,36 @@ virNetworkDHCPRangeDefParseXML(virNetworkIpDefPtr def,
             if ((mac != NULL) &&
                 (virParseMacAddr(mac, &addr[0]) != 0)) {
                 virNetworkReportError(VIR_ERR_INTERNAL_ERROR,
-                                      _("cannot parse MAC address '%s'"),
-                                      mac);
+                                      _("Cannot parse MAC address '%s' in network '%s'"),
+                                      mac, networkName);
                 VIR_FREE(mac);
             }
             name = virXMLPropString(cur, "name");
             if ((name != NULL) && (!c_isalpha(name[0]))) {
                 virNetworkReportError(VIR_ERR_INTERNAL_ERROR,
-                                      _("cannot use name address '%s'"),
-                                      name);
+                                      _("Cannot use name address '%s' in network '%s'"),
+                                      name, networkName);
                 VIR_FREE(name);
             }
             /*
              * You need at least one MAC address or one host name
              */
             if ((mac == NULL) && (name == NULL)) {
-                VIR_FREE(mac);
-                VIR_FREE(name);
-                cur = cur->next;
-                continue;
+                virNetworkReportError(VIR_ERR_XML_ERROR,
+                                      _("Static host definition in network '%s' must have mac or name attribute"),
+                                      networkName);
+                return -1;
             }
             ip = virXMLPropString(cur, "ip");
-            if (virSocketParseAddr(ip, &inaddr, AF_UNSPEC) < 0) {
+            if ((ip == NULL) ||
+                (virSocketParseAddr(ip, &inaddr, AF_UNSPEC) < 0)) {
+                virNetworkReportError(VIR_ERR_XML_ERROR,
+                                      _("Missing IP address in static host definition for network '%s'"),
+                                      networkName);
                 VIR_FREE(ip);
                 VIR_FREE(mac);
                 VIR_FREE(name);
-                cur = cur->next;
-                continue;
+                return -1;
             }
             VIR_FREE(ip);
             if (VIR_REALLOC_N(def->hosts, def->nhosts + 1) < 0) {
@@ -541,7 +545,7 @@ virNetworkIPParseXML(const char *networkName,
         while (cur != NULL) {
             if (cur->type == XML_ELEMENT_NODE &&
                 xmlStrEqual(cur->name, BAD_CAST "dhcp")) {
-                result = virNetworkDHCPRangeDefParseXML(def, cur);
+                result = virNetworkDHCPRangeDefParseXML(networkName, def, cur);
                 if (result)
                     goto error;