ignore "eth0." dns prefixes

Some people use "eth0.machine.example.com" instead of
"machine.example.com" as reverse dns names.

Signed-off-by: Joern Engel <joern@logfs.org>

1 files changed, 8 insertions, 4 deletions

diff --git a/cancd.c b/cancd.c
index 96f7182..e640efe 100644
--- a/cancd.c
+++ b/cancd.c
@@ -742,7 +742,7 @@ static void dns_visitor(void *_sip, long unused, u32 ip, size_t unused2)
 	struct source_ip *sip = _sip;
 	struct hostent *he;
 	const char *old;
-	char *new, *c;
+	char *new, *c, *name;
 
 	/*
 	 * Close idle logfiles.  Maybe the machine no longer exists,
@@ -755,7 +755,11 @@ static void dns_visitor(void *_sip, long unused, u32 ip, size_t unused2)
 	he = gethostbyaddr(&ip, 4, AF_INET);
 	if (!he)
 		return;
-	new = strdup(he->h_name);
+	/* Ignore "eth0." prefix - some people use this */
+	name = he->h_name;
+	if (!strncmp(name, "eth0.", strlen("eth0.")))
+		name += strlen("eth0.");
+	new = strdup(name);
 	if (!new)
 		return;
 	for (c = new; c; c++) {
@@ -769,12 +773,12 @@ static void dns_visitor(void *_sip, long unused, u32 ip, size_t unused2)
 	old = sip->filename;
 	sip->filename = new;
 	if (!old || !new || strcmp(old, new))
-		syslog(LOG_INFO, "resolved %u.%u.%u.%u to %s",
+		syslog(LOG_INFO, "resolved %u.%u.%u.%u to %s (%s)",
 			(ip >> 0) & 0xff,
 			(ip >> 8) & 0xff,
 			(ip >> 16) & 0xff,
 			(ip >> 24) & 0xff,
-			sip->filename);
+			sip->filename, he->h_name);
 	free((void *)old);
 }