From 5dfc665931b0e8a7242c2fb982f899e98d9c3c24 Mon Sep 17 00:00:00 2001
From: Florian Forster <octo@verplant.org>
Date: Sat, 3 Jun 2006 10:33:47 +0200
Subject: [PATCH] Use `AI_CANONNAME' if it's defined.

This will follow PTR records. `www.verplant.org' is changed to `verplant.org',
for example. It's not what I intended (I wanted a reverse lookup of
IP-addresses), but still better than what we had originally. I don't know if
I'll leave it like this. Might be though..
---
 src/liboping.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/src/liboping.c b/src/liboping.c
index debd432..6131107 100644
--- a/src/liboping.c
+++ b/src/liboping.c
@@ -927,6 +927,9 @@ int ping_host_add (pingobj_t *obj, const char *host)
 	ai_hints.ai_flags     = 0;
 #ifdef AI_ADDRCONFIG
 	ai_hints.ai_flags    |= AI_ADDRCONFIG;
+#endif
+#ifdef AI_CANONNAME
+	ai_hints.ai_flags    |= AI_CANONNAME;
 #endif
 	ai_hints.ai_family    = obj->addrfamily;
 	ai_hints.ai_socktype  = SOCK_RAW;
@@ -1043,6 +1046,28 @@ int ping_host_add (pingobj_t *obj, const char *host)
 		ph->addrlen = ai_ptr->ai_addrlen;
 		ph->addrfamily = ai_ptr->ai_family;
 
+#ifdef AI_CANONNAME
+		if ((ai_ptr->ai_canonname != NULL)
+				&& (strcmp (ph->hostname, ai_ptr->ai_canonname) != 0))
+		{
+			char *old_hostname;
+
+			dprintf ("ph->hostname = %s; ai_ptr->ai_canonname = %s;\n",
+					ph->hostname, ai_ptr->ai_canonname);
+
+			old_hostname = ph->hostname;
+			if ((ph->hostname = strdup (ai_ptr->ai_canonname)) == NULL)
+			{
+				/* strdup failed, falling back to old hostname */
+				ph->hostname = old_hostname;
+			}
+			else if (old_hostname != NULL)
+			{
+				free (old_hostname);
+			}
+		}
+#endif /* AI_CANONNAME */
+
 		break;
 	}
 
-- 
2.30.2