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openairinterface5g/openair3/NAS/COMMON/API/NETWORK/network_api.c
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/*
* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The OpenAirInterface Software Alliance licenses this file to You under
* the OAI Public License, Version 1.1 (the "License"); you may not use this file
* except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.openairinterface.org/?page_id=698
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*-------------------------------------------------------------------------------
* For more information about the OpenAirInterface (OAI) Software Alliance:
* contact@openairinterface.org
*/
/*****************************************************************************
Source network_api.c
Version 0.1
Date 2012/03/01
Product NAS stack
Subsystem Application Programming Interface
Author Frederic Maurel
Description Implements the API used by the NAS layer to send/receive
message to/from the network sublayer
*****************************************************************************/
#include "network_api.h"
#include "commonDef.h"
#include "nas_log.h"
#include "socket.h"
#include "as_message.h"
#include <string.h> // strerror, memset
#include <netdb.h> // gai_strerror
#include <errno.h> // errno
#include <unistd.h> // gethostname
/****************************************************************************/
/**************** E X T E R N A L D E F I N I T I O N S ****************/
/****************************************************************************/
/****************************************************************************/
/******************* L O C A L D E F I N I T I O N S *******************/
/****************************************************************************/
/* -------------------
* Connection endpoint
* -------------------
* The connection endpoint is used to send/receive data to/from the
* network sublayer. Its definition depends on the underlaying mechanism
* chosen to communicate (network socket, I/O terminal device, async FIFO).
* A connection endpoint is handled using an identifier, and functions
* used to retreive the file descriptor actually allocated by the system,
* to receive data, to send data, and to perform clean up when connection
* is shut down.
* Only one single end to end connection with the network sublayer is
* managed at a time.
*/
static struct {
/* Connection endpoint reference */
void* endpoint;
/* Connection endpoint handlers */
void* (*open) (int, const char*, const char*);
int (*getfd)(const void*);
ssize_t (*recv) (void*, char*, size_t);
ssize_t (*send) (const void*, const char*, size_t);
void (*close)(void*);
} _network_api_id;
#define NETWORK_API_OPEN(a, b, c) _network_api_id.open(a, b, c)
#define NETWORK_API_GETFD() _network_api_id.getfd(_network_api_id.endpoint)
#define NETWORK_API_RECV(a, b) _network_api_id.recv(_network_api_id.endpoint, a, b)
#define NETWORK_API_SEND(a, b) _network_api_id.send(_network_api_id.endpoint, a, b)
#define NETWORK_API_CLOSE() _network_api_id.close(_network_api_id.endpoint)
/*
* The buffer used to receive data from the network sublayer
*/
#define NETWORK_API_RECV_BUFFER_SIZE 4096
/*
* The buffer used to send data to the network sublayer
*/
#define NETWORK_API_SEND_BUFFER_SIZE NETWORK_API_RECV_BUFFER_SIZE
/****************************************************************************/
/****************** E X P O R T E D F U N C T I O N S ******************/
/****************************************************************************/
/****************************************************************************
** **
** Name: network_api_initialize() **
** **
** Description: Initializes the network API from which the NAS layer **
** will send/receive messages to/from the network sublayer **
** **
** Inputs: host: The name of the host from which the net- **
** work sublayer will connect **
** port: The local port number **
** Others: None **
** **
** Outputs: Return: RETURNerror, RETURNok **
** Others: _network_api_id **
** **
***************************************************************************/
int network_api_initialize(const char* host, const char* port)
{
LOG_FUNC_IN;
/* Initialize network socket handlers */
_network_api_id.open = socket_udp_open;
_network_api_id.getfd = socket_get_fd;
_network_api_id.recv = socket_recv;
_network_api_id.send = socket_send;
_network_api_id.close = socket_close;
/* Initialize UDP communication channel with the network layer */
_network_api_id.endpoint = NETWORK_API_OPEN(SOCKET_CLIENT, host, port);
if (_network_api_id.endpoint == NULL) {
LOG_TRACE(ERROR, "NET-API - Failed to open connection endpoint, %s",
((errno < 0) ? gai_strerror(errno) : strerror(errno)));
LOG_FUNC_RETURN (RETURNerror);
}
char _network_api_send_buffer[NETWORK_API_SEND_BUFFER_SIZE];
gethostname(_network_api_send_buffer, NETWORK_API_SEND_BUFFER_SIZE);
LOG_TRACE(INFO, "NET-API - Network's UDP socket %d is BOUND to %s/%s",
network_api_get_fd(), _network_api_send_buffer, port);
LOG_FUNC_RETURN (RETURNok);
}
/****************************************************************************
** **
** Name: network_api_get_fd() **
** **
** Description: Get the file descriptor of the connection endpoint used **
** to send/receive messages to/from the network sublayer **
** **
** Inputs: None **
** Others: _network_api_id **
** **
** Outputs: Return: The file descriptor of the connection end- **
** point used by the network sublayer **
** Others: None **
** **
***************************************************************************/
int network_api_get_fd(void)
{
LOG_FUNC_IN;
LOG_FUNC_RETURN (NETWORK_API_GETFD());
}
/****************************************************************************
** **
** Name: network_api_read_data() **
** **
** Description: Read data received from the network sublayer **
** **
** Inputs: fd: File descriptor of the connection endpoint **
** from which data have been received **
** Others: _network_api_id **
** **
** Outputs: Return: The number of bytes read when success; **
** RETURNerror otherwise **
** Others: _network_api_recv_buffer, _network_api_id **
** **
***************************************************************************/
int network_api_read_data(int fd, char* _network_api_recv_buffer)
{
LOG_FUNC_IN;
int rbytes;
/* Sanity check */
int sfd = network_api_get_fd();
if (fd != sfd) {
LOG_TRACE(ERROR, "NET-API - Endpoint %d is not the one created for communication with the network sublayer (%d)", fd, sfd);
LOG_FUNC_RETURN (RETURNerror);
}
memset(_network_api_recv_buffer, 0, NETWORK_API_RECV_BUFFER_SIZE);
/* Receive data from the network sublayer */
rbytes = NETWORK_API_RECV(_network_api_recv_buffer,
NETWORK_API_RECV_BUFFER_SIZE);
if (rbytes == RETURNerror) {
LOG_TRACE(ERROR, "NET-API - recv() failed, %s", strerror(errno));
LOG_FUNC_RETURN (RETURNerror);
} else if (rbytes == 0) {
LOG_TRACE(WARNING, "NET-API - A signal was caught");
} else {
LOG_TRACE(INFO, "NET-API - %d bytes received from the network "
"sublayer", rbytes);
LOG_DUMP(_network_api_recv_buffer, rbytes);
}
LOG_FUNC_RETURN (rbytes);
}
/****************************************************************************
** **
** Name: network_api_send_data() **
** **
** Description: Send data to the network sublayer **
** **
** Inputs: fd: File descriptor of the connection endpoint **
** to which data have to be sent **
** length: Number of bytes to send **
** Others: _network_api_send_buffer, _network_api_id **
** **
** Outputs: Return: The number of bytes sent when success; **
** RETURNerror otherwise **
** Others: None **
** **
***************************************************************************/
static int network_api_send_data(int fd, int length, char* _network_api_send_buffer)
{
LOG_FUNC_IN;
int sbytes;
/* Sanity check */
int sfd = network_api_get_fd();
if (fd != sfd) {
LOG_TRACE(ERROR, "NET-API - Endpoint %d is not the one created for communication with the network sublayer (%d)", fd, sfd);
LOG_FUNC_RETURN (RETURNerror);
}
/* Send data to the network sublayer */
sbytes = NETWORK_API_SEND(_network_api_send_buffer, length);
if (sbytes == RETURNerror) {
LOG_TRACE(ERROR, "NET-API - send() failed, %s", strerror(errno));
LOG_FUNC_RETURN (RETURNerror);
} else if (sbytes == 0) {
LOG_TRACE(WARNING, "NET-API - A signal was caught");
} else {
LOG_TRACE(INFO, "NET-API - %d bytes sent to the network sublayer",
sbytes);
LOG_DUMP(_network_api_send_buffer, sbytes);
}
LOG_FUNC_RETURN (sbytes);
}
/****************************************************************************
** **
** Name: network_api_close() **
** **
** Description: Clean the network API from which the NAS layer sent/recei-**
** ved messages to/from the network sublayer **
** **
** Inputs: fd: File descriptor of the connection endpoint **
** allocated by the system to communicate **
** with the network sublayer **
** Others: None **
** **
** Outputs: Return: None **
** Others: _network_api_id **
** **
***************************************************************************/
void network_api_close(int fd)
{
LOG_FUNC_IN;
/* Sanity check */
int sfd = network_api_get_fd();
if (fd != sfd) {
LOG_TRACE(ERROR, "NET-API - Endpoint %d is not the one created for communication with the network sublayer (%d)", fd, sfd);
LOG_FUNC_OUT;
return;
}
/* Cleanup the connection endpoint */
NETWORK_API_CLOSE();
_network_api_id.endpoint = NULL;
LOG_FUNC_OUT;
}
/****************************************************************************
** **
** Name: network_api_decode_data() **
** **
** Description: Decodes the message received from the network and fills **
** the corresponding network data structure. **
** **
** Inputs: length: Number of bytes to decode **
** Others: _network_api_recv_buffer **
** **
** Outputs: Return: The identifier of the received AS **
** message when successfully decoded; **
** RETURNerror otherwise **
** Others: _as_data **
** **
***************************************************************************/
int network_api_decode_data(char* _network_api_recv_buffer, int length, as_message_t* _as_data)
{
LOG_FUNC_IN;
/* Decode the Access Stratum message received from the network */
int as_id = as_message_decode(_network_api_recv_buffer, _as_data, length);
if (as_id != RETURNerror) {
LOG_TRACE(INFO, "NET-API - AS message id=0x%x successfully decoded",
as_id);
}
LOG_FUNC_RETURN (as_id);
}
/****************************************************************************
** **
** Name: network_api_encode_data() **
** **
** Description: Encodes Access Stratum message to be sent to the network **
** **
** Inputs data: Generic pointer to the AS data to encode **
** Others: None **
** **
** Outputs: Return: The number of characters that have been **
** successfully encoded; **
** RETURNerror otherwise. **
** Others: _network_api_send_buffer **
** **
***************************************************************************/
static int network_api_encode_data(void* data, char* _network_api_send_buffer)
{
LOG_FUNC_IN;
/* Encode the Access Stratum message */
int bytes = as_message_encode(_network_api_send_buffer,
(as_message_t*)(data),
NETWORK_API_SEND_BUFFER_SIZE);
if (bytes != RETURNerror) {
LOG_TRACE(INFO, "NET-API - %d bytes encoded", bytes);
}
LOG_FUNC_RETURN (bytes);
}
/****************************************************************************
** **
** Name: as_message_send() **
** **
** Description: Service provided to the EPS Mobility Management protocol **
** at the EMMAS Access Point (EMMAS-SAP) to send AS messages **
** to the Access Stratum sublayer. **
** **
** Inputs: as_msg: The AS message to send **
** Others: _network_api_send_buffer, _network_api_id **
** **
** Outputs: Return: The number of bytes sent when success; **
** RETURNerror Otherwise **
** Others: _network_api_send_buffer **
** **
***************************************************************************/
int as_message_send(as_message_t* as_msg)
{
int bytes;
LOG_FUNC_IN;
LOG_TRACE(INFO, "NET-API - Send message 0x%.4x to the Access Stratum "
"layer", as_msg->msgID);
char _network_api_send_buffer[NETWORK_API_SEND_BUFFER_SIZE];
/* Encode the AS message */
bytes = network_api_encode_data(as_msg, _network_api_send_buffer);
if (bytes > 0) {
/* Get the network file descriptor */
int fd = network_api_get_fd();
if (fd != RETURNerror) {
/* Send the AS message to the network */
bytes = network_api_send_data(fd, bytes, _network_api_send_buffer);
}
}
LOG_FUNC_RETURN (bytes);
}
/****************************************************************************/
/********************* L O C A L F U N C T I O N S *********************/
/****************************************************************************/