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/**************************************************************************/
/* */
/* Copyright (c) Microsoft Corporation. All rights reserved. */
/* */
/* This software is licensed under the Microsoft Software License */
/* Terms for Microsoft Azure RTOS. Full text of the license can be */
/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
/* and in the root directory of this software. */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** NetX Secure Component */
/** */
/** Datagram Transport Layer Security (DTLS) */
/** */
/**************************************************************************/
/**************************************************************************/
#define NX_SECURE_SOURCE_CODE
#include "nx_secure_dtls.h"
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_secure_dtls_server_create PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* Timothy Stapko, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function creates an instance of a DTLS server to handle */
/* incoming DTLS requests on a particular UDP port. Due to the fact */
/* that UDP is stateless, DTLS requests from multiple clients can come */
/* in on a single port while other DTLS sessions are active. Thus, the */
/* server is needed to maintain active sessions and properly route */
/* incoming messages to the proper handler. */
/* */
/* The session buffer parameter is used to hold the control blocks for */
/* all the possible simultaneous DTLS sessions for the DTLS server. It */
/* should be allocated with a size that is an even multiple of the */
/* size of the NX_SECURE_DTLS_SESSION control block structure. */
/* */
/* To calculate the necessary metadata size, the API */
/* nx_secure_tls_metadata_size_calculate may be used. */
/* */
/* INPUT */
/* */
/* server_ptr DTLS server control block */
/* ip_ptr Pointer to IP instance */
/* port Server port */
/* timeout Timeout value */
/* session_buffer DTLS sessions buffer */
/* session_buffer_size Size of DTLS sessions buffer */
/* crypto_table Crypto table */
/* crypto_metadata_buffer Encryption metadata buffer */
/* crypto_metadata_size Encryption metadata size */
/* packet_reassembly_buffer DTLS reassembly buffer */
/* packet_reassembly_buffer_size Size of reassembly buffer */
/* connect_notify Callback for new connections */
/* receive_notify Callback for received data */
/* */
/* OUTPUT */
/* */
/* status Completion status */
/* */
/* CALLS */
/* */
/* _nx_secure_dtls_session_create Initialize DTLS control block */
/* nx_udp_socket_create Set up UDP socket */
/* tx_mutex_get Get protection mutex */
/* tx_mutex_put Put protection mutex */
/* */
/* CALLED BY */
/* */
/* Application Code */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 Timothy Stapko Initial Version 6.0 */
/* 09-30-2020 Timothy Stapko Modified comment(s), */
/* resulting in version 6.1 */
/* */
/**************************************************************************/
UINT _nx_secure_dtls_server_create(NX_SECURE_DTLS_SERVER *server_ptr, NX_IP *ip_ptr, UINT port, ULONG timeout,
VOID *session_buffer, UINT session_buffer_size,
const NX_SECURE_TLS_CRYPTO *crypto_table,
VOID *crypto_metadata_buffer, ULONG crypto_metadata_size,
UCHAR *packet_reassembly_buffer, UINT packet_reassembly_buffer_size,
UINT (*connect_notify)(NX_SECURE_DTLS_SESSION *dtls_session, NXD_ADDRESS *ip_address, UINT port),
UINT (*receive_notify)(NX_SECURE_DTLS_SESSION *dtls_session))
{
#ifdef NX_SECURE_ENABLE_DTLS
UINT status;
UINT i;
NX_SECURE_DTLS_SESSION *current_session;
ULONG session_metadata_size;
UINT session_pkt_buffer_size;
UCHAR *session_pkt_buffer;
UCHAR *session_metadata;
UINT num_sessions;
NX_SECURE_DTLS_SERVER *tail_ptr;
/* Figure out number of sessions. */
num_sessions = session_buffer_size / sizeof(NX_SECURE_DTLS_SESSION);
/* Check sessions buffer size. */
if(num_sessions == 0)
{
return(NX_INVALID_PARAMETERS);
}
/* Set server parameters. */
server_ptr->nx_dtls_server_ip_ptr = ip_ptr;
server_ptr->nx_dtls_server_listen_port = port;
server_ptr->nx_dtls_server_sessions_count = num_sessions;
server_ptr->nx_dtls_server_timeout = timeout;
/* Set up session buffer. */
server_ptr->nx_dtls_server_sessions = (NX_SECURE_DTLS_SESSION*)session_buffer;
/* Setup per-session packet buffer. */
session_pkt_buffer_size = packet_reassembly_buffer_size / num_sessions;
session_pkt_buffer = packet_reassembly_buffer;
/* Get our per-session metadata. */
session_metadata = crypto_metadata_buffer;
session_metadata_size = crypto_metadata_size / num_sessions;
/* Set up UDP socket. */
status = nx_udp_socket_create(ip_ptr, &(server_ptr->nx_dtls_server_udp_socket), "DTLS Server",
NX_IP_NORMAL, NX_FRAGMENT_OKAY, timeout, 8192);
/* Store a pointer to our DTLS server instance in our UDP socket.
This enables the receive callback to access the right server. */
server_ptr->nx_dtls_server_udp_socket.nx_udp_socket_reserved_ptr = server_ptr;
if(status != NX_SUCCESS)
{
return(status);
}
/* Assign callbacks. */
server_ptr->nx_secure_dtls_receive_notify = receive_notify;
server_ptr->nx_secure_dtls_connect_notify = connect_notify;
/* Reset the protocol version override. */
server_ptr -> nx_dtls_server_protocol_version_override = 0;
/* Initialize sessions. */
for(i = 0; i < num_sessions; ++i)
{
/* Get the current session. */
current_session = &(server_ptr->nx_dtls_server_sessions[i]);
/* Initialize each DTLS session - don't add remote certificate data here. */
status = _nx_secure_dtls_session_create(current_session, crypto_table, session_metadata, session_metadata_size,
session_pkt_buffer, session_pkt_buffer_size, 0, NX_NULL, 0);
if(status != NX_SUCCESS)
{
/* Delete the created UDP socket. */
nx_udp_socket_delete(&(server_ptr->nx_dtls_server_udp_socket));
return(status);
}
/* Assign the parent server instance. */
current_session->nx_secure_dtls_server_parent = server_ptr;
/* Assign other parameters. */
current_session->nx_secure_dtls_local_port = port;
current_session->nx_secure_dtls_udp_socket = &(server_ptr->nx_dtls_server_udp_socket);
/* Advance metadata buffer. */
session_metadata = &session_metadata[session_metadata_size];
/* Advance packet buffer. */
session_pkt_buffer = &session_pkt_buffer[session_pkt_buffer_size];
}
/* Get the protection. */
tx_mutex_get(&_nx_secure_tls_protection, TX_WAIT_FOREVER);
/* Place the new DTLS server control block on the list of created DTLS server. */
if (_nx_secure_dtls_server_created_ptr)
{
/* Pickup tail pointer. */
tail_ptr = _nx_secure_dtls_server_created_ptr -> nx_dtls_server_created_previous;
/* Place the new DTLS server control block in the list. */
_nx_secure_dtls_server_created_ptr -> nx_dtls_server_created_previous = server_ptr;
tail_ptr -> nx_dtls_server_created_next = server_ptr;
/* Setup this DTLS server's created links. */
server_ptr -> nx_dtls_server_created_previous = tail_ptr;
server_ptr -> nx_dtls_server_created_next = _nx_secure_dtls_server_created_ptr;
}
else
{
/* The created DTLS server list is empty. Add DTLS server control block to empty list. */
_nx_secure_dtls_server_created_ptr = server_ptr;
server_ptr -> nx_dtls_server_created_previous = server_ptr;
server_ptr -> nx_dtls_server_created_next = server_ptr;
}
_nx_secure_dtls_server_created_count++;
/* Release the protection. */
tx_mutex_put(&_nx_secure_tls_protection);
return(NX_SUCCESS);
#else
NX_PARAMETER_NOT_USED(server_ptr);
NX_PARAMETER_NOT_USED(ip_ptr);
NX_PARAMETER_NOT_USED(port);
NX_PARAMETER_NOT_USED(timeout);
NX_PARAMETER_NOT_USED(session_buffer);
NX_PARAMETER_NOT_USED(session_buffer_size);
NX_PARAMETER_NOT_USED(crypto_table);
NX_PARAMETER_NOT_USED(crypto_metadata_buffer);
NX_PARAMETER_NOT_USED(crypto_metadata_size);
NX_PARAMETER_NOT_USED(packet_reassembly_buffer);
NX_PARAMETER_NOT_USED(packet_reassembly_buffer_size);
NX_PARAMETER_NOT_USED(connect_notify);
NX_PARAMETER_NOT_USED(receive_notify);
return(NX_NOT_SUPPORTED);
#endif /* NX_SECURE_ENABLE_DTLS */
}