Add macro to define clusterNode.ip buffer size.

Add REDIS_CLUSTER_IPLEN macro to define the size of the clusterNode ip
character array. Additionally use this macro in inet_ntop(3) calls where
the size of the array was being defined manually.

The REDIS_CLUSTER_IPLEN is defined as INET_ADDRSTRLEN which defines the
correct size of a buffer to store an IPv4 address in. The
INET_ADDRSTRLEN macro itself is defined in the <netinet/in.h> header
file and should be portable across the majority of systems.

2 files changed, 4 insertions, 3 deletions

diff --git a/src/cluster.c b/src/cluster.c
index e60d82a64..dacddbcc0 100644
--- a/src/cluster.c
+++ b/src/cluster.c
@@ -758,7 +758,7 @@ void nodeIp2String(char *buf, clusterLink *link) {
 
     if (getpeername(link->fd, (struct sockaddr*) &sa, &salen) == -1)
         redisPanic("getpeername() failed.");
-    inet_ntop(sa.sin_family,(void*)&(sa.sin_addr),buf,16);
+    inet_ntop(sa.sin_family,(void*)&(sa.sin_addr),buf,REDIS_CLUSTER_IPLEN);
 }
 
 
@@ -2084,7 +2084,7 @@ void clusterCommand(redisClient *c) {
         /* Finally add the node to the cluster with a random name, this 
          * will get fixed in the first handshake (ping/pong). */
         n = createClusterNode(NULL,REDIS_NODE_HANDSHAKE|REDIS_NODE_MEET);
-        inet_ntop(sa.sin_family,(void*)&(sa.sin_addr),n->ip,16);
+        inet_ntop(sa.sin_family,(void*)&(sa.sin_addr),n->ip,REDIS_CLUSTER_IPLEN);
         n->port = port;
         clusterAddNode(n);
         addReply(c,shared.ok);
diff --git a/src/redis.h b/src/redis.h
index e3542967f..2cfcce356 100644
--- a/src/redis.h
+++ b/src/redis.h
@@ -120,7 +120,7 @@
 #define REDIS_DEFAULT_AOF_REWRITE_INCREMENTAL_FSYNC 1
 #define REDIS_DEFAULT_MIN_SLAVES_TO_WRITE 0
 #define REDIS_DEFAULT_MIN_SLAVES_MAX_LAG 10
-#define REDIS_IP_STR_LEN 16
+#define REDIS_IP_STR_LEN INET6_ADDRSTRLEN
 #define REDIS_BINDADDR_MAX 16
 
 /* Protocol and I/O related defines */
@@ -564,6 +564,7 @@ typedef struct redisOpArray {
 #define REDIS_CLUSTER_FAIL 1        /* The cluster can't work */
 #define REDIS_CLUSTER_NAMELEN 40    /* sha1 hex length */
 #define REDIS_CLUSTER_PORT_INCR 10000 /* Cluster port = baseport + PORT_INCR */
+#define REDIS_CLUSTER_IPLEN INET_ADDRSTRLEN /* IPv4 address string length */
 
 /* The following defines are amunt of time, sometimes expressed as
  * multiplicators of the node timeout value (when ending with MULT). */