net: dns: fix the sizeof the inet_ntop buffer with a sizeof macro

From the manpage for inet_ntop

  This function converts the network address structure src in the af
  address family into a character string.  The resulting string is
  copied to the buffer pointed to by dst, which must be a non-null
  pointer.  The caller specifies the number of bytes available in
  this buffer in the argument size.

In an unintended misconfiguration the resolve max string ended up
being 20 and tracking thru some wierd code issues determined some
stack corruption which came back to the shell command. So, just
fix the size argument to be the sizeof which then led to the next
problem that the size is being ignored by inet_ntop.

Signed-off-by: Charles Hardin <[email protected]>

Author: ckhardin

subsys/net/lib/shell/dns.c

@@ -38,13 +38,13 @@ static void dns_result_cb(enum dns_resolve_status status,
 		case AF_INET:
 			net_addr_ntop(AF_INET,
 				      &net_sin(&info->ai_addr)->sin_addr,
-				      str, NET_IPV4_ADDR_LEN);
+				      str, sizeof(str));
 			break;
 
 		case AF_INET6:
 			net_addr_ntop(AF_INET6,
 				      &net_sin6(&info->ai_addr)->sin6_addr,
-				      str, NET_IPV6_ADDR_LEN);
+				      str, sizeof(str));
 			break;
 
 		case AF_LOCAL: