Bus error/invalid alignment on HP-UX (1.1.7) about freeradius-client HOT 4 OPEN

--- lib/sendserver.c.orig	2018-01-23 10:57:07.861253190 +0100
+++ lib/sendserver.c	2018-01-23 11:19:12.328861458 +0100
@@ -214,6 +214,15 @@
  *
  */
 
+/* Used to avoid casts between char buffers and the header struct since
+** this might cause alignment problems on some architectures.
+ */
+typedef union auth_buf_u
+{
+    AUTH_HDR hdr;
+    char buf[BUFFER_LEN];
+} auth_buf_t;
+
 int rc_send_server (rc_handle *rh, SEND_DATA *data, char *msg)
 {
 	int             sockfd;
@@ -230,8 +239,8 @@
 	size_t			secretlen;
 	char            secret[MAX_SECRET_LENGTH + 1];
 	unsigned char   vector[AUTH_VECTOR_LEN];
-	char            recv_buffer[BUFFER_LEN];
-	char            send_buffer[BUFFER_LEN];
+        auth_buf_t      recv_auth_buf;
+        auth_buf_t      send_auth_buf;
 	int		retries;
 	VALUE_PAIR 	*vp;
 	struct pollfd	pfd;
@@ -313,7 +322,7 @@
 	}
 
 	/* Build a request */
-	auth = (AUTH_HDR *) send_buffer;
+        auth = &send_auth_buf.hdr;
 	auth->code = data->code;
 	auth->id = data->seq_nbr;
 
@@ -345,7 +354,7 @@
 
 	for (;;)
 	{
-		sendto (sockfd, (char *) auth, (unsigned int) total_length, (int) 0,
+		sendto (sockfd, send_auth_buf.buf, (unsigned int) total_length, (int) 0,
 			SA(&sinremote), sizeof (struct sockaddr_in));
 
 		pfd.fd = sockfd;
@@ -383,8 +392,8 @@
 		}
 	}
 	salen = sizeof(sinremote);
-	length = recvfrom (sockfd, (char *) recv_buffer,
-			   (int) sizeof (recv_buffer),
+	length = recvfrom (sockfd, recv_auth_buf.buf,
+			   (int) sizeof (recv_auth_buf),
 			   (int) 0, SA(&sinremote), &salen);
 
 	if (length <= 0)
@@ -396,7 +405,7 @@
 		return ERROR_RC;
 	}
 
-	recv_auth = (AUTH_HDR *)recv_buffer;
+        recv_auth = &recv_auth_buf.hdr;
 
 	if (length < AUTH_HDR_LEN || length < ntohs(recv_auth->length)) {
 		rc_log(LOG_ERR, "rc_send_server: recvfrom: %s:%d: reply is too short",