From c14f1ed20647f2c6d0ae14bf8c50234217d2a57b Mon Sep 17 00:00:00 2001
From: Michal Privoznik <mprivozn@redhat.com>
Date: Wed, 18 Oct 2017 14:59:01 +0200
Subject: [PATCH] conf: Parse user supplied aliases

If driver that is calling the parse supports user supplied
aliases, they can be parsed even for inactive XMLs. However, to
avoid any clashes with aliases that libvirt generates, the user
ones have to have "ua-" prefix.

Note, that some drivers don't have notion of device aliases at
all. Also, in order to support user supplied aliases some extra
checks need to be done (e.g. during hotplug). Therefore we can't
just enable this feature for all the drivers. Thus we need a flag
that drivers set to tell parsing code that they can handle user
supplied device aliases.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---
 src/conf/domain_conf.c | 18 +++++++++++++++---
 src/conf/domain_conf.h |  1 +
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index ce9b4ee7f0..40fcbc7dfa 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -6454,6 +6454,10 @@ virDomainDeviceAddressParseXML(xmlNodePtr address,
 }
 
 
+#define USER_ALIAS_PREFIX "ua-"
+#define USER_ALIAS_CHARS \
+    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-"
+
 /* Parse the XML definition for a device address
  * @param node XML nodeset to parse for device address definition
  */
@@ -6472,6 +6476,7 @@ virDomainDeviceInfoParseXML(virDomainXMLOptionPtr xmlopt ATTRIBUTE_UNUSED,
     xmlNodePtr rom = NULL;
     char *type = NULL;
     char *rombar = NULL;
+    char *aliasStr = NULL;
     int ret = -1;
 
     virDomainDeviceInfoClear(info);
@@ -6480,7 +6485,6 @@ virDomainDeviceInfoParseXML(virDomainXMLOptionPtr xmlopt ATTRIBUTE_UNUSED,
     while (cur != NULL) {
         if (cur->type == XML_ELEMENT_NODE) {
             if (alias == NULL &&
-                !(flags & VIR_DOMAIN_DEF_PARSE_INACTIVE) &&
                 virXMLNodeNameEqual(cur, "alias")) {
                 alias = cur;
             } else if (address == NULL &&
@@ -6502,8 +6506,15 @@ virDomainDeviceInfoParseXML(virDomainXMLOptionPtr xmlopt ATTRIBUTE_UNUSED,
         cur = cur->next;
     }
 
-    if (alias)
-        info->alias = virXMLPropString(alias, "name");
+    if (alias) {
+        aliasStr = virXMLPropString(alias, "name");
+
+        if (!(flags & VIR_DOMAIN_DEF_PARSE_INACTIVE) ||
+            (xmlopt->config.features & VIR_DOMAIN_DEF_FEATURE_USER_ALIAS &&
+             STRPREFIX(aliasStr, USER_ALIAS_PREFIX) &&
+             strspn(aliasStr, USER_ALIAS_CHARS) == strlen(aliasStr)))
+            VIR_STEAL_PTR(info->alias, aliasStr);
+    }
 
     if (master) {
         info->mastertype = VIR_DOMAIN_CONTROLLER_MASTER_USB;
@@ -6537,6 +6548,7 @@ virDomainDeviceInfoParseXML(virDomainXMLOptionPtr xmlopt ATTRIBUTE_UNUSED,
         virDomainDeviceInfoClear(info);
     VIR_FREE(type);
     VIR_FREE(rombar);
+    VIR_FREE(aliasStr);
     return ret;
 }
 
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index f251f390b7..1a3574aa72 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -2488,6 +2488,7 @@ typedef enum {
     VIR_DOMAIN_DEF_FEATURE_OFFLINE_VCPUPIN = (1 << 2),
     VIR_DOMAIN_DEF_FEATURE_NAME_SLASH = (1 << 3),
     VIR_DOMAIN_DEF_FEATURE_INDIVIDUAL_VCPUS = (1 << 4),
+    VIR_DOMAIN_DEF_FEATURE_USER_ALIAS = (1 << 5),
 } virDomainDefFeatures;