[PATCH 1/3] virNetSocketCheckProtocols: Separate out checking family via getaddrinfo()

[Michal Privoznik]

The virNetSocketCheckProtocols() function is supposed to tell
caller whether IPv4 and/or IPv6 is supported on the system. In
the initial round, it uses getifaddrs() to see if an interface
has IPv4/IPv6 address assigned and then to double check IPv6 it
uses getaddrinfo() to lookup IPv6 loopback address. Separate out
this latter code because it is going to be reused.

Since the original code lived under an #ifdef and the new
function doesn't it is marked as unused - because on some systems
it may be so.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 src/rpc/virnetsocket.c | 63 ++++++++++++++++++++++++++----------------
 1 file changed, 39 insertions(+), 24 deletions(-)

diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c
index d1f4c531aa..b6bc3edc3b 100644
--- a/src/rpc/virnetsocket.c
+++ b/src/rpc/virnetsocket.c
@@ -141,16 +141,48 @@ static int virNetSocketForkDaemon(const char *binary)
 }
 #endif
 
+
+static int G_GNUC_UNUSED
+virNetSocketCheckProtocolByLookup(const char *address,
+                                  int family,
+                                  bool *hasFamily)
+{
+    struct addrinfo hints;
+    struct addrinfo *ai = NULL;
+    int gaierr;
+
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_family = family;
+    hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
+    hints.ai_socktype = SOCK_STREAM;
+
+    if ((gaierr = getaddrinfo(address, NULL, &hints, &ai)) != 0) {
+        *hasFamily = false;
+
+        if (gaierr == EAI_FAMILY ||
+#ifdef EAI_ADDRFAMILY
+            gaierr == EAI_ADDRFAMILY ||
+#endif
+            gaierr == EAI_NONAME) {
+        } else {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("Cannot resolve ::1 address: %s"),
+                           gai_strerror(gaierr));
+            return -1;
+        }
+    } else {
+        *hasFamily = true;
+    }
+
+    freeaddrinfo(ai);
+    return 0;
+}
+
 int virNetSocketCheckProtocols(bool *hasIPv4,
                                bool *hasIPv6)
 {
 #ifdef HAVE_IFADDRS_H
     struct ifaddrs *ifaddr = NULL, *ifa;
-    struct addrinfo hints;
-    struct addrinfo *ai = NULL;
-    int gaierr;
-
-    memset(&hints, 0, sizeof(hints));
 
     *hasIPv4 = *hasIPv6 = false;
 
@@ -172,26 +204,9 @@ int virNetSocketCheckProtocols(bool *hasIPv4,
 
     freeifaddrs(ifaddr);
 
-    hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
-    hints.ai_family = AF_INET6;
-    hints.ai_socktype = SOCK_STREAM;
 
-    if ((gaierr = getaddrinfo("::1", NULL, &hints, &ai)) != 0) {
-        if (gaierr == EAI_FAMILY ||
-# ifdef EAI_ADDRFAMILY
-            gaierr == EAI_ADDRFAMILY ||
-# endif
-            gaierr == EAI_NONAME) {
-            *hasIPv6 = false;
-        } else {
-            virReportError(VIR_ERR_INTERNAL_ERROR,
-                           _("Cannot resolve ::1 address: %s"),
-                           gai_strerror(gaierr));
-            return -1;
-        }
-    }
-
-    freeaddrinfo(ai);
+    if (virNetSocketCheckProtocolByLookup("::1", AF_INET6, hasIPv6) < 0)
+        return -1;
 
     VIR_DEBUG("Protocols: v4 %d v6 %d", *hasIPv4, *hasIPv6);
 
-- 
2.26.2