mbedtls_net_accept: client_ip can be NULL
This is currently used in example programs, but not explicitly documented.
diff --git a/include/mbedtls/net_sockets.h b/include/mbedtls/net_sockets.h
index de33552..f09f8bf 100644
--- a/include/mbedtls/net_sockets.h
+++ b/include/mbedtls/net_sockets.h
@@ -117,9 +117,10 @@
*
* \param bind_ctx Relevant socket
* \param client_ctx Will contain the connected client socket
- * \param client_ip Will contain the client IP address
+ * \param client_ip Will contain the client IP address, can be NULL
* \param buf_size Size of the client_ip buffer
- * \param ip_len Will receive the size of the client IP written
+ * \param ip_len Will receive the size of the client IP written,
+ * can be NULL if client_ip == NULL
*
* \return 0 if successful, or
* MBEDTLS_ERR_NET_ACCEPT_FAILED, or