zephyr/net/ip/tinydtls/netq.h

104 lines
2.7 KiB
C

/* netq.h -- Simple packet queue
*
* Copyright (C) 2010--2012 Olaf Bergmann <bergmann@tzi.org>
*
* This file is part of the library tinyDTLS. Please see the file
* LICENSE for terms of use.
*/
#ifndef _DTLS_NETQ_H_
#define _DTLS_NETQ_H_
#include "tinydtls.h"
#include "global.h"
#include "dtls.h"
#include "dtls_time.h"
/**
* \defgroup netq Network Packet Queue
* The netq utility functions implement an ordered queue of data packets
* to send over the network and can also be used to queue received packets
* from the network.
* @{
*/
#ifndef NETQ_MAXCNT
#ifdef DTLS_ECC
#define NETQ_MAXCNT 5 /**< maximum number of elements in netq structure */
#elif defined(DTLS_PSK)
#define NETQ_MAXCNT 3 /**< maximum number of elements in netq structure */
#endif
#endif
/**
* Datagrams in the netq_t structure have a fixed maximum size of
* DTLS_MAX_BUF to simplify memory management on constrained nodes. */
typedef unsigned char netq_packet_t[DTLS_MAX_BUF];
typedef struct netq_t {
struct netq_t *next;
clock_time_t t; /**< when to send PDU for the next time */
unsigned int timeout; /**< randomized timeout value */
dtls_peer_t *peer; /**< remote address */
uint16_t epoch;
uint8_t type;
unsigned char retransmit_cnt; /**< retransmission counter, will be removed when zero */
size_t length; /**< actual length of data */
#ifndef WITH_CONTIKI
unsigned char data[]; /**< the datagram to send */
#else
netq_packet_t data; /**< the datagram to send */
#endif
} netq_t;
#ifndef WITH_CONTIKI
static inline void netq_init()
{ }
#else
void netq_init();
#endif
/**
* Adds a node to the given queue, ordered by their time-stamp t.
* This function returns @c 0 on error, or non-zero if @p node has
* been added successfully.
*
* @param queue A pointer to the queue head where @p node will be added.
* @param node The new item to add.
* @return @c 0 on error, or non-zero if the new item was added.
*/
int netq_insert_node(list_t queue, netq_t *node);
/** Destroys specified node and releases any memory that was allocated
* for the associated datagram. */
void netq_node_free(netq_t *node);
/** Removes all items from given queue and frees the allocated storage */
void netq_delete_all(list_t queue);
/** Creates a new node suitable for adding to a netq_t queue. */
netq_t *netq_node_new(size_t size);
/**
* Returns a pointer to the first item in given queue or NULL if
* empty.
*/
netq_t *netq_head(list_t queue);
netq_t *netq_next(netq_t *p);
void netq_remove(list_t queue, netq_t *p);
/**
* Removes the first item in given queue and returns a pointer to the
* removed element. If queue is empty when netq_pop_first() is called,
* this function returns NULL.
*/
netq_t *netq_pop_first(list_t queue);
/**@}*/
#endif /* _DTLS_NETQ_H_ */