You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

150 lines
4.8 KiB

/*
* Copyright (C) 2015-2017 Simon Brummer
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @defgroup net_gnrc_tcp TCP
* @ingroup net_gnrc
* @brief RIOT's tcp implementation for the gnrc stack
*
* @{
*
* @file
* @brief TCP paket handling declarations
*
* @author Simon Brummer <simon.brummer@posteo.de>
*/
#ifndef GNRC_TCP_INTERNAL_PKT_H
#define GNRC_TCP_INTERNAL_PKT_H
#include "net/conn/tcp.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Build a reset packet from an incomming packet.
*
* This function builds a reset from an incomming packet
* for cases where the connection has not been established
*
* @param[out] out_pkt outgoing reset packet
* @param[in] in_pkt incomming packet
*
* @return Zero on success
* @return -ENOMEM if pktbuf is full.
*/
int _pkt_build_reset_from_pkt(gnrc_pktsnip_t **out_pkt, gnrc_pktsnip_t *in_pkt);
/**
* @brief Build and allocate a tcp paket in paketbuffer, conn stores pointer to new paket.
*
* @param[in,out] tcb This connections Transmission control block.
* @param[out] out_pkt Pointer to paket to build
* @param[out] seq_con Number of Bytes, the packet will consume in sequence number spce
* @param[in] ctl control bits to set in pkt
* @param[in] seq_num sequence number to use in new paket
* @param[in] ack_num acknowledgment number to use in new paket
* @param[in] payload pointer to payload buffer
* @param[in] payload_len payload size
*
* @return Zero on success.
* @return -ENOMEM if pktbuf is full.
*/
int _pkt_build(gnrc_tcp_tcb_t *tcb, gnrc_pktsnip_t **out_pkt, uint16_t *seq_con,
const uint16_t ctl, const uint32_t seq_num, const uint32_t ack_num,
void *payload, const size_t payload_len);
/**
* @brief Sends a packet to the peer
*
* @param[in,out] tcb This connections Transmission control block.
* @param[in] out_pkt pointer to paket to send
* @param[in] seq_con sequence number consumption of the paket to send
* @param[in] retransmit is this a retransmission ?
*
* @return Zero on success.
* @return -EINVAL if out_pkt was NULL
*/
int _pkt_send(gnrc_tcp_tcb_t *tcb, gnrc_pktsnip_t *out_pkt, const uint16_t seq_con,
const bool retransmit);
/**
* @brief Checks sequence number
*
* @param[in,out] tcb This connections Transmission control block.
* @param[in] seq_num sequence number from the segment
* @param[in] seg_len length of a segments payload
*
* @return Zero if the sequence number is invalid
* @return Non-zero if the sequence number is acceptable
*/
int _pkt_chk_seq_num(const gnrc_tcp_tcb_t *tcb, const uint32_t seq_num, const uint32_t seg_len);
/**
* @brief Extracts the length of a segment
*
* @param[in] pkt Packet to calculate payload length
*
* @return number consumption in sequence number space
*/
uint32_t _pkt_get_seg_len(gnrc_pktsnip_t *pkt);
/**
* @brief Calculates a segments payload length
*
* @param[in] pkt Packet to calculate payload length
*
* @return the segments payload length in bytes
*/
uint32_t _pkt_get_pay_len(gnrc_pktsnip_t *pkt);
/**
* @brief Adds a paket to the retransmission mechanism
*
* @param[in,out] tcb This connections Transmission control block.
* @param[in] pkt paket to add to the retransmission mechanism
* @param[in] retransmit is this a retransmission ?
*
* @return Zero on success
* @return -ENOMEM if the retransmission queue is full
* @return -EINVAL if pkt is null
*/
int _pkt_setup_retransmit(gnrc_tcp_tcb_t *tcb, gnrc_pktsnip_t *pkt, const bool retransmit);
/**
* @brief Acknowledges and removes packet from the retransmission mechanism
*
* @param[in,out] tcb This connections Transmission control block.
* @param[in] ack Acknowldegment number used to acknowledge packets
*
* @return Zero on success
* @return -ENODATA if there is nothing to acknowledge
*/
int _pkt_acknowledge(gnrc_tcp_tcb_t *tcb, const uint32_t ack);
/**
* @brief Calculates checksum over payload, tcp-header and network layer header
*
* @param[in] hdr gnrc_pktsnip_t to tcp-header
* @param[in] pseudo_hdr gnrc_pktsnip_t to network layer header
* @param[in] payload gnrc_pktsnip_t to payload
*
* @return non zero checksum if given network layer is supported
* @return zero if given network layer is not supported
*/
uint16_t _pkt_calc_csum(const gnrc_pktsnip_t *hdr, const gnrc_pktsnip_t *pseudo_hdr,
const gnrc_pktsnip_t *payload);
#ifdef __cplusplus
}
#endif
#endif /* GNRC_TCP_INTERNAL_PKT_H */
/** @} */