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A version of LWIP, provided for backwards compatibility.

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trunk/Core/lwIP/core/tcp.c@0:5e1631496985, 2012-05-08 (annotated)

Committer:: root@mbed.org
Date:: Tue May 08 15:32:10 2012 +0100
Revision:: 0:5e1631496985

initial commit

Who changed what in which revision?

User	Revision	Line number	New contents of line
root@mbed.org	0:5e1631496985	1	/**
root@mbed.org	0:5e1631496985	2	* @file
root@mbed.org	0:5e1631496985	3	* Transmission Control Protocol for IP
root@mbed.org	0:5e1631496985	4	*
root@mbed.org	0:5e1631496985	5	* This file contains common functions for the TCP implementation, such as functinos
root@mbed.org	0:5e1631496985	6	* for manipulating the data structures and the TCP timer functions. TCP functions
root@mbed.org	0:5e1631496985	7	* related to input and output is found in tcp_in.c and tcp_out.c respectively.
root@mbed.org	0:5e1631496985	8	*
root@mbed.org	0:5e1631496985	9	*/
root@mbed.org	0:5e1631496985	10
root@mbed.org	0:5e1631496985	11	/*
root@mbed.org	0:5e1631496985	12	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
root@mbed.org	0:5e1631496985	13	* All rights reserved.
root@mbed.org	0:5e1631496985	14	*
root@mbed.org	0:5e1631496985	15	* Redistribution and use in source and binary forms, with or without modification,
root@mbed.org	0:5e1631496985	16	* are permitted provided that the following conditions are met:
root@mbed.org	0:5e1631496985	17	*
root@mbed.org	0:5e1631496985	18	* 1. Redistributions of source code must retain the above copyright notice,
root@mbed.org	0:5e1631496985	19	* this list of conditions and the following disclaimer.
root@mbed.org	0:5e1631496985	20	* 2. Redistributions in binary form must reproduce the above copyright notice,
root@mbed.org	0:5e1631496985	21	* this list of conditions and the following disclaimer in the documentation
root@mbed.org	0:5e1631496985	22	* and/or other materials provided with the distribution.
root@mbed.org	0:5e1631496985	23	* 3. The name of the author may not be used to endorse or promote products
root@mbed.org	0:5e1631496985	24	* derived from this software without specific prior written permission.
root@mbed.org	0:5e1631496985	25	*
root@mbed.org	0:5e1631496985	26	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
root@mbed.org	0:5e1631496985	27	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
root@mbed.org	0:5e1631496985	28	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
root@mbed.org	0:5e1631496985	29	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
root@mbed.org	0:5e1631496985	30	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
root@mbed.org	0:5e1631496985	31	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
root@mbed.org	0:5e1631496985	32	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
root@mbed.org	0:5e1631496985	33	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
root@mbed.org	0:5e1631496985	34	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
root@mbed.org	0:5e1631496985	35	* OF SUCH DAMAGE.
root@mbed.org	0:5e1631496985	36	*
root@mbed.org	0:5e1631496985	37	* This file is part of the lwIP TCP/IP stack.
root@mbed.org	0:5e1631496985	38	*
root@mbed.org	0:5e1631496985	39	* Author: Adam Dunkels <adam@sics.se>
root@mbed.org	0:5e1631496985	40	*
root@mbed.org	0:5e1631496985	41	*/
root@mbed.org	0:5e1631496985	42
root@mbed.org	0:5e1631496985	43	#include "lwip/opt.h"
root@mbed.org	0:5e1631496985	44
root@mbed.org	0:5e1631496985	45	#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
root@mbed.org	0:5e1631496985	46
root@mbed.org	0:5e1631496985	47	#include "lwip/def.h"
root@mbed.org	0:5e1631496985	48	#include "lwip/mem.h"
root@mbed.org	0:5e1631496985	49	#include "lwip/memp.h"
root@mbed.org	0:5e1631496985	50	#include "lwip/snmp.h"
root@mbed.org	0:5e1631496985	51	#include "lwip/tcp.h"
root@mbed.org	0:5e1631496985	52	#include "lwip/debug.h"
root@mbed.org	0:5e1631496985	53
root@mbed.org	0:5e1631496985	54	#include <string.h>
root@mbed.org	0:5e1631496985	55
root@mbed.org	0:5e1631496985	56	const char *tcp_state_str[] = {
root@mbed.org	0:5e1631496985	57	"CLOSED",
root@mbed.org	0:5e1631496985	58	"LISTEN",
root@mbed.org	0:5e1631496985	59	"SYN_SENT",
root@mbed.org	0:5e1631496985	60	"SYN_RCVD",
root@mbed.org	0:5e1631496985	61	"ESTABLISHED",
root@mbed.org	0:5e1631496985	62	"FIN_WAIT_1",
root@mbed.org	0:5e1631496985	63	"FIN_WAIT_2",
root@mbed.org	0:5e1631496985	64	"CLOSE_WAIT",
root@mbed.org	0:5e1631496985	65	"CLOSING",
root@mbed.org	0:5e1631496985	66	"LAST_ACK",
root@mbed.org	0:5e1631496985	67	"TIME_WAIT"
root@mbed.org	0:5e1631496985	68	};
root@mbed.org	0:5e1631496985	69
root@mbed.org	0:5e1631496985	70	/* Incremented every coarse grained timer shot (typically every 500 ms). */
root@mbed.org	0:5e1631496985	71	u32_t tcp_ticks;
root@mbed.org	0:5e1631496985	72	const u8_t tcp_backoff[13] =
root@mbed.org	0:5e1631496985	73	{ 1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7};
root@mbed.org	0:5e1631496985	74	/* Times per slowtmr hits */
root@mbed.org	0:5e1631496985	75	const u8_t tcp_persist_backoff[7] = { 3, 6, 12, 24, 48, 96, 120 };
root@mbed.org	0:5e1631496985	76
root@mbed.org	0:5e1631496985	77	/* The TCP PCB lists. */
root@mbed.org	0:5e1631496985	78
root@mbed.org	0:5e1631496985	79	/** List of all TCP PCBs bound but not yet (connected \|\| listening) */
root@mbed.org	0:5e1631496985	80	struct tcp_pcb *tcp_bound_pcbs;
root@mbed.org	0:5e1631496985	81	/** List of all TCP PCBs in LISTEN state */
root@mbed.org	0:5e1631496985	82	union tcp_listen_pcbs_t tcp_listen_pcbs;
root@mbed.org	0:5e1631496985	83	/** List of all TCP PCBs that are in a state in which
root@mbed.org	0:5e1631496985	84	* they accept or send data. */
root@mbed.org	0:5e1631496985	85	struct tcp_pcb *tcp_active_pcbs;
root@mbed.org	0:5e1631496985	86	/** List of all TCP PCBs in TIME-WAIT state */
root@mbed.org	0:5e1631496985	87	struct tcp_pcb *tcp_tw_pcbs;
root@mbed.org	0:5e1631496985	88
root@mbed.org	0:5e1631496985	89	struct tcp_pcb *tcp_tmp_pcb;
root@mbed.org	0:5e1631496985	90
root@mbed.org	0:5e1631496985	91	static u8_t tcp_timer;
root@mbed.org	0:5e1631496985	92	static u16_t tcp_new_port(void);
root@mbed.org	0:5e1631496985	93
root@mbed.org	0:5e1631496985	94	/**
root@mbed.org	0:5e1631496985	95	* Called periodically to dispatch TCP timers.
root@mbed.org	0:5e1631496985	96	*
root@mbed.org	0:5e1631496985	97	*/
root@mbed.org	0:5e1631496985	98	void
root@mbed.org	0:5e1631496985	99	tcp_tmr(void)
root@mbed.org	0:5e1631496985	100	{
root@mbed.org	0:5e1631496985	101	/* Call tcp_fasttmr() every 250 ms */
root@mbed.org	0:5e1631496985	102	tcp_fasttmr();
root@mbed.org	0:5e1631496985	103
root@mbed.org	0:5e1631496985	104	if (++tcp_timer & 1) {
root@mbed.org	0:5e1631496985	105	/* Call tcp_tmr() every 500 ms, i.e., every other timer
root@mbed.org	0:5e1631496985	106	tcp_tmr() is called. */
root@mbed.org	0:5e1631496985	107	tcp_slowtmr();
root@mbed.org	0:5e1631496985	108	}
root@mbed.org	0:5e1631496985	109	}
root@mbed.org	0:5e1631496985	110
root@mbed.org	0:5e1631496985	111	/**
root@mbed.org	0:5e1631496985	112	* Closes the connection held by the PCB.
root@mbed.org	0:5e1631496985	113	*
root@mbed.org	0:5e1631496985	114	* Listening pcbs are freed and may not be referenced any more.
root@mbed.org	0:5e1631496985	115	* Connection pcbs are freed if not yet connected and may not be referenced
root@mbed.org	0:5e1631496985	116	* any more. If a connection is established (at least SYN received or in
root@mbed.org	0:5e1631496985	117	* a closing state), the connection is closed, and put in a closing state.
root@mbed.org	0:5e1631496985	118	* The pcb is then automatically freed in tcp_slowtmr(). It is therefore
root@mbed.org	0:5e1631496985	119	* unsafe to reference it.
root@mbed.org	0:5e1631496985	120	*
root@mbed.org	0:5e1631496985	121	* @param pcb the tcp_pcb to close
root@mbed.org	0:5e1631496985	122	* @return ERR_OK if connection has been closed
root@mbed.org	0:5e1631496985	123	* another err_t if closing failed and pcb is not freed
root@mbed.org	0:5e1631496985	124	*/
root@mbed.org	0:5e1631496985	125	err_t
root@mbed.org	0:5e1631496985	126	tcp_close(struct tcp_pcb *pcb)
root@mbed.org	0:5e1631496985	127	{
root@mbed.org	0:5e1631496985	128	err_t err;
root@mbed.org	0:5e1631496985	129
root@mbed.org	0:5e1631496985	130	#if TCP_DEBUG
root@mbed.org	0:5e1631496985	131	LWIP_DEBUGF(TCP_DEBUG, ("tcp_close: closing in "));
root@mbed.org	0:5e1631496985	132	tcp_debug_print_state(pcb->state);
root@mbed.org	0:5e1631496985	133	#endif /* TCP_DEBUG */
root@mbed.org	0:5e1631496985	134
root@mbed.org	0:5e1631496985	135	switch (pcb->state) {
root@mbed.org	0:5e1631496985	136	case CLOSED:
root@mbed.org	0:5e1631496985	137	/* Closing a pcb in the CLOSED state might seem erroneous,
root@mbed.org	0:5e1631496985	138	* however, it is in this state once allocated and as yet unused
root@mbed.org	0:5e1631496985	139	* and the user needs some way to free it should the need arise.
root@mbed.org	0:5e1631496985	140	* Calling tcp_close() with a pcb that has already been closed, (i.e. twice)
root@mbed.org	0:5e1631496985	141	* or for a pcb that has been used and then entered the CLOSED state
root@mbed.org	0:5e1631496985	142	* is erroneous, but this should never happen as the pcb has in those cases
root@mbed.org	0:5e1631496985	143	* been freed, and so any remaining handles are bogus. */
root@mbed.org	0:5e1631496985	144	err = ERR_OK;
root@mbed.org	0:5e1631496985	145	TCP_RMV(&tcp_bound_pcbs, pcb);
root@mbed.org	0:5e1631496985	146	memp_free(MEMP_TCP_PCB, pcb);
root@mbed.org	0:5e1631496985	147	pcb = NULL;
root@mbed.org	0:5e1631496985	148	break;
root@mbed.org	0:5e1631496985	149	case LISTEN:
root@mbed.org	0:5e1631496985	150	err = ERR_OK;
root@mbed.org	0:5e1631496985	151	tcp_pcb_remove((struct tcp_pcb **)&tcp_listen_pcbs.pcbs, pcb);
root@mbed.org	0:5e1631496985	152	memp_free(MEMP_TCP_PCB_LISTEN, pcb);
root@mbed.org	0:5e1631496985	153	pcb = NULL;
root@mbed.org	0:5e1631496985	154	break;
root@mbed.org	0:5e1631496985	155	case SYN_SENT:
root@mbed.org	0:5e1631496985	156	err = ERR_OK;
root@mbed.org	0:5e1631496985	157	tcp_pcb_remove(&tcp_active_pcbs, pcb);
root@mbed.org	0:5e1631496985	158	memp_free(MEMP_TCP_PCB, pcb);
root@mbed.org	0:5e1631496985	159	pcb = NULL;
root@mbed.org	0:5e1631496985	160	snmp_inc_tcpattemptfails();
root@mbed.org	0:5e1631496985	161	break;
root@mbed.org	0:5e1631496985	162	case SYN_RCVD:
root@mbed.org	0:5e1631496985	163	err = tcp_send_ctrl(pcb, TCP_FIN);
root@mbed.org	0:5e1631496985	164	if (err == ERR_OK) {
root@mbed.org	0:5e1631496985	165	snmp_inc_tcpattemptfails();
root@mbed.org	0:5e1631496985	166	pcb->state = FIN_WAIT_1;
root@mbed.org	0:5e1631496985	167	}
root@mbed.org	0:5e1631496985	168	break;
root@mbed.org	0:5e1631496985	169	case ESTABLISHED:
root@mbed.org	0:5e1631496985	170	err = tcp_send_ctrl(pcb, TCP_FIN);
root@mbed.org	0:5e1631496985	171	if (err == ERR_OK) {
root@mbed.org	0:5e1631496985	172	snmp_inc_tcpestabresets();
root@mbed.org	0:5e1631496985	173	pcb->state = FIN_WAIT_1;
root@mbed.org	0:5e1631496985	174	}
root@mbed.org	0:5e1631496985	175	break;
root@mbed.org	0:5e1631496985	176	case CLOSE_WAIT:
root@mbed.org	0:5e1631496985	177	err = tcp_send_ctrl(pcb, TCP_FIN);
root@mbed.org	0:5e1631496985	178	if (err == ERR_OK) {
root@mbed.org	0:5e1631496985	179	snmp_inc_tcpestabresets();
root@mbed.org	0:5e1631496985	180	pcb->state = LAST_ACK;
root@mbed.org	0:5e1631496985	181	}
root@mbed.org	0:5e1631496985	182	break;
root@mbed.org	0:5e1631496985	183	default:
root@mbed.org	0:5e1631496985	184	/* Has already been closed, do nothing. */
root@mbed.org	0:5e1631496985	185	err = ERR_OK;
root@mbed.org	0:5e1631496985	186	pcb = NULL;
root@mbed.org	0:5e1631496985	187	break;
root@mbed.org	0:5e1631496985	188	}
root@mbed.org	0:5e1631496985	189
root@mbed.org	0:5e1631496985	190	if (pcb != NULL && err == ERR_OK) {
root@mbed.org	0:5e1631496985	191	/* To ensure all data has been sent when tcp_close returns, we have
root@mbed.org	0:5e1631496985	192	to make sure tcp_output doesn't fail.
root@mbed.org	0:5e1631496985	193	Since we don't really have to ensure all data has been sent when tcp_close
root@mbed.org	0:5e1631496985	194	returns (unsent data is sent from tcp timer functions, also), we don't care
root@mbed.org	0:5e1631496985	195	for the return value of tcp_output for now. */
root@mbed.org	0:5e1631496985	196	/* @todo: When implementing SO_LINGER, this must be changed somehow:
root@mbed.org	0:5e1631496985	197	If SOF_LINGER is set, the data should be sent when tcp_close returns. */
root@mbed.org	0:5e1631496985	198	tcp_output(pcb);
root@mbed.org	0:5e1631496985	199	}
root@mbed.org	0:5e1631496985	200	return err;
root@mbed.org	0:5e1631496985	201	}
root@mbed.org	0:5e1631496985	202
root@mbed.org	0:5e1631496985	203	/**
root@mbed.org	0:5e1631496985	204	* Abandons a connection and optionally sends a RST to the remote
root@mbed.org	0:5e1631496985	205	* host. Deletes the local protocol control block. This is done when
root@mbed.org	0:5e1631496985	206	* a connection is killed because of shortage of memory.
root@mbed.org	0:5e1631496985	207	*
root@mbed.org	0:5e1631496985	208	* @param pcb the tcp_pcb to abort
root@mbed.org	0:5e1631496985	209	* @param reset boolean to indicate whether a reset should be sent
root@mbed.org	0:5e1631496985	210	*/
root@mbed.org	0:5e1631496985	211	void
root@mbed.org	0:5e1631496985	212	tcp_abandon(struct tcp_pcb *pcb, int reset)
root@mbed.org	0:5e1631496985	213	{
root@mbed.org	0:5e1631496985	214	u32_t seqno, ackno;
root@mbed.org	0:5e1631496985	215	u16_t remote_port, local_port;
root@mbed.org	0:5e1631496985	216	struct ip_addr remote_ip, local_ip;
root@mbed.org	0:5e1631496985	217	#if LWIP_CALLBACK_API
root@mbed.org	0:5e1631496985	218	void (* errf)(void *arg, err_t err);
root@mbed.org	0:5e1631496985	219	#endif /* LWIP_CALLBACK_API */
root@mbed.org	0:5e1631496985	220	void *errf_arg;
root@mbed.org	0:5e1631496985	221
root@mbed.org	0:5e1631496985	222
root@mbed.org	0:5e1631496985	223	/* Figure out on which TCP PCB list we are, and remove us. If we
root@mbed.org	0:5e1631496985	224	are in an active state, call the receive function associated with
root@mbed.org	0:5e1631496985	225	the PCB with a NULL argument, and send an RST to the remote end. */
root@mbed.org	0:5e1631496985	226	if (pcb->state == TIME_WAIT) {
root@mbed.org	0:5e1631496985	227	tcp_pcb_remove(&tcp_tw_pcbs, pcb);
root@mbed.org	0:5e1631496985	228	memp_free(MEMP_TCP_PCB, pcb);
root@mbed.org	0:5e1631496985	229	} else {
root@mbed.org	0:5e1631496985	230	seqno = pcb->snd_nxt;
root@mbed.org	0:5e1631496985	231	ackno = pcb->rcv_nxt;
root@mbed.org	0:5e1631496985	232	ip_addr_set(&local_ip, &(pcb->local_ip));
root@mbed.org	0:5e1631496985	233	ip_addr_set(&remote_ip, &(pcb->remote_ip));
root@mbed.org	0:5e1631496985	234	local_port = pcb->local_port;
root@mbed.org	0:5e1631496985	235	remote_port = pcb->remote_port;
root@mbed.org	0:5e1631496985	236	#if LWIP_CALLBACK_API
root@mbed.org	0:5e1631496985	237	errf = pcb->errf;
root@mbed.org	0:5e1631496985	238	#endif /* LWIP_CALLBACK_API */
root@mbed.org	0:5e1631496985	239	errf_arg = pcb->callback_arg;
root@mbed.org	0:5e1631496985	240	tcp_pcb_remove(&tcp_active_pcbs, pcb);
root@mbed.org	0:5e1631496985	241	if (pcb->unacked != NULL) {
root@mbed.org	0:5e1631496985	242	tcp_segs_free(pcb->unacked);
root@mbed.org	0:5e1631496985	243	}
root@mbed.org	0:5e1631496985	244	if (pcb->unsent != NULL) {
root@mbed.org	0:5e1631496985	245	tcp_segs_free(pcb->unsent);
root@mbed.org	0:5e1631496985	246	}
root@mbed.org	0:5e1631496985	247	#if TCP_QUEUE_OOSEQ
root@mbed.org	0:5e1631496985	248	if (pcb->ooseq != NULL) {
root@mbed.org	0:5e1631496985	249	tcp_segs_free(pcb->ooseq);
root@mbed.org	0:5e1631496985	250	}
root@mbed.org	0:5e1631496985	251	#endif /* TCP_QUEUE_OOSEQ */
root@mbed.org	0:5e1631496985	252	memp_free(MEMP_TCP_PCB, pcb);
root@mbed.org	0:5e1631496985	253	TCP_EVENT_ERR(errf, errf_arg, ERR_ABRT);
root@mbed.org	0:5e1631496985	254	if (reset) {
root@mbed.org	0:5e1631496985	255	LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_abandon: sending RST\n"));
root@mbed.org	0:5e1631496985	256	tcp_rst(seqno, ackno, &local_ip, &remote_ip, local_port, remote_port);
root@mbed.org	0:5e1631496985	257	}
root@mbed.org	0:5e1631496985	258	}
root@mbed.org	0:5e1631496985	259	}
root@mbed.org	0:5e1631496985	260
root@mbed.org	0:5e1631496985	261	/**
root@mbed.org	0:5e1631496985	262	* Binds the connection to a local portnumber and IP address. If the
root@mbed.org	0:5e1631496985	263	* IP address is not given (i.e., ipaddr == NULL), the IP address of
root@mbed.org	0:5e1631496985	264	* the outgoing network interface is used instead.
root@mbed.org	0:5e1631496985	265	*
root@mbed.org	0:5e1631496985	266	* @param pcb the tcp_pcb to bind (no check is done whether this pcb is
root@mbed.org	0:5e1631496985	267	* already bound!)
root@mbed.org	0:5e1631496985	268	* @param ipaddr the local ip address to bind to (use IP_ADDR_ANY to bind
root@mbed.org	0:5e1631496985	269	* to any local address
root@mbed.org	0:5e1631496985	270	* @param port the local port to bind to
root@mbed.org	0:5e1631496985	271	* @return ERR_USE if the port is already in use
root@mbed.org	0:5e1631496985	272	* ERR_OK if bound
root@mbed.org	0:5e1631496985	273	*/
root@mbed.org	0:5e1631496985	274	err_t
root@mbed.org	0:5e1631496985	275	tcp_bind(struct tcp_pcb pcb, struct ip_addr ipaddr, u16_t port)
root@mbed.org	0:5e1631496985	276	{
root@mbed.org	0:5e1631496985	277	struct tcp_pcb *cpcb;
root@mbed.org	0:5e1631496985	278
root@mbed.org	0:5e1631496985	279	LWIP_ERROR("tcp_bind: can only bind in state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
root@mbed.org	0:5e1631496985	280
root@mbed.org	0:5e1631496985	281	if (port == 0) {
root@mbed.org	0:5e1631496985	282	port = tcp_new_port();
root@mbed.org	0:5e1631496985	283	}
root@mbed.org	0:5e1631496985	284	/* Check if the address already is in use. */
root@mbed.org	0:5e1631496985	285	/* Check the listen pcbs. */
root@mbed.org	0:5e1631496985	286	for(cpcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs;
root@mbed.org	0:5e1631496985	287	cpcb != NULL; cpcb = cpcb->next) {
root@mbed.org	0:5e1631496985	288	if (cpcb->local_port == port) {
root@mbed.org	0:5e1631496985	289	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
root@mbed.org	0:5e1631496985	290	ip_addr_isany(ipaddr) \|\|
root@mbed.org	0:5e1631496985	291	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
root@mbed.org	0:5e1631496985	292	return ERR_USE;
root@mbed.org	0:5e1631496985	293	}
root@mbed.org	0:5e1631496985	294	}
root@mbed.org	0:5e1631496985	295	}
root@mbed.org	0:5e1631496985	296	/* Check the connected pcbs. */
root@mbed.org	0:5e1631496985	297	for(cpcb = tcp_active_pcbs;
root@mbed.org	0:5e1631496985	298	cpcb != NULL; cpcb = cpcb->next) {
root@mbed.org	0:5e1631496985	299	if (cpcb->local_port == port) {
root@mbed.org	0:5e1631496985	300	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
root@mbed.org	0:5e1631496985	301	ip_addr_isany(ipaddr) \|\|
root@mbed.org	0:5e1631496985	302	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
root@mbed.org	0:5e1631496985	303	return ERR_USE;
root@mbed.org	0:5e1631496985	304	}
root@mbed.org	0:5e1631496985	305	}
root@mbed.org	0:5e1631496985	306	}
root@mbed.org	0:5e1631496985	307	/* Check the bound, not yet connected pcbs. */
root@mbed.org	0:5e1631496985	308	for(cpcb = tcp_bound_pcbs; cpcb != NULL; cpcb = cpcb->next) {
root@mbed.org	0:5e1631496985	309	if (cpcb->local_port == port) {
root@mbed.org	0:5e1631496985	310	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
root@mbed.org	0:5e1631496985	311	ip_addr_isany(ipaddr) \|\|
root@mbed.org	0:5e1631496985	312	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
root@mbed.org	0:5e1631496985	313	return ERR_USE;
root@mbed.org	0:5e1631496985	314	}
root@mbed.org	0:5e1631496985	315	}
root@mbed.org	0:5e1631496985	316	}
root@mbed.org	0:5e1631496985	317	/* @todo: until SO_REUSEADDR is implemented (see task #6995 on savannah),
root@mbed.org	0:5e1631496985	318	* we have to check the pcbs in TIME-WAIT state, also: */
root@mbed.org	0:5e1631496985	319	for(cpcb = tcp_tw_pcbs; cpcb != NULL; cpcb = cpcb->next) {
root@mbed.org	0:5e1631496985	320	if (cpcb->local_port == port) {
root@mbed.org	0:5e1631496985	321	if (ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
root@mbed.org	0:5e1631496985	322	return ERR_USE;
root@mbed.org	0:5e1631496985	323	}
root@mbed.org	0:5e1631496985	324	}
root@mbed.org	0:5e1631496985	325	}
root@mbed.org	0:5e1631496985	326
root@mbed.org	0:5e1631496985	327	if (!ip_addr_isany(ipaddr)) {
root@mbed.org	0:5e1631496985	328	pcb->local_ip = *ipaddr;
root@mbed.org	0:5e1631496985	329	}
root@mbed.org	0:5e1631496985	330	pcb->local_port = port;
root@mbed.org	0:5e1631496985	331	TCP_REG(&tcp_bound_pcbs, pcb);
root@mbed.org	0:5e1631496985	332	LWIP_DEBUGF(TCP_DEBUG, ("tcp_bind: bind to port %"U16_F"\n", port));
root@mbed.org	0:5e1631496985	333	return ERR_OK;
root@mbed.org	0:5e1631496985	334	}
root@mbed.org	0:5e1631496985	335	#if LWIP_CALLBACK_API
root@mbed.org	0:5e1631496985	336	/**
root@mbed.org	0:5e1631496985	337	* Default accept callback if no accept callback is specified by the user.
root@mbed.org	0:5e1631496985	338	*/
root@mbed.org	0:5e1631496985	339	static err_t
root@mbed.org	0:5e1631496985	340	tcp_accept_null(void arg, struct tcp_pcb pcb, err_t err)
root@mbed.org	0:5e1631496985	341	{
root@mbed.org	0:5e1631496985	342	LWIP_UNUSED_ARG(arg);
root@mbed.org	0:5e1631496985	343	LWIP_UNUSED_ARG(pcb);
root@mbed.org	0:5e1631496985	344	LWIP_UNUSED_ARG(err);
root@mbed.org	0:5e1631496985	345
root@mbed.org	0:5e1631496985	346	return ERR_ABRT;
root@mbed.org	0:5e1631496985	347	}
root@mbed.org	0:5e1631496985	348	#endif /* LWIP_CALLBACK_API */
root@mbed.org	0:5e1631496985	349
root@mbed.org	0:5e1631496985	350	/**
root@mbed.org	0:5e1631496985	351	* Set the state of the connection to be LISTEN, which means that it
root@mbed.org	0:5e1631496985	352	* is able to accept incoming connections. The protocol control block
root@mbed.org	0:5e1631496985	353	* is reallocated in order to consume less memory. Setting the
root@mbed.org	0:5e1631496985	354	* connection to LISTEN is an irreversible process.
root@mbed.org	0:5e1631496985	355	*
root@mbed.org	0:5e1631496985	356	* @param pcb the original tcp_pcb
root@mbed.org	0:5e1631496985	357	* @param backlog the incoming connections queue limit
root@mbed.org	0:5e1631496985	358	* @return tcp_pcb used for listening, consumes less memory.
root@mbed.org	0:5e1631496985	359	*
root@mbed.org	0:5e1631496985	360	* @note The original tcp_pcb is freed. This function therefore has to be
root@mbed.org	0:5e1631496985	361	* called like this:
root@mbed.org	0:5e1631496985	362	* tpcb = tcp_listen(tpcb);
root@mbed.org	0:5e1631496985	363	*/
root@mbed.org	0:5e1631496985	364	struct tcp_pcb *
root@mbed.org	0:5e1631496985	365	tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog)
root@mbed.org	0:5e1631496985	366	{
root@mbed.org	0:5e1631496985	367	struct tcp_pcb_listen *lpcb;
root@mbed.org	0:5e1631496985	368
root@mbed.org	0:5e1631496985	369	LWIP_UNUSED_ARG(backlog);
root@mbed.org	0:5e1631496985	370	LWIP_ERROR("tcp_listen: pcb already connected", pcb->state == CLOSED, return NULL);
root@mbed.org	0:5e1631496985	371
root@mbed.org	0:5e1631496985	372	/* already listening? */
root@mbed.org	0:5e1631496985	373	if (pcb->state == LISTEN) {
root@mbed.org	0:5e1631496985	374	return pcb;
root@mbed.org	0:5e1631496985	375	}
root@mbed.org	0:5e1631496985	376	lpcb = (struct tcp_pcb_listen *)memp_malloc(MEMP_TCP_PCB_LISTEN);
root@mbed.org	0:5e1631496985	377	if (lpcb == NULL) {
root@mbed.org	0:5e1631496985	378	return NULL;
root@mbed.org	0:5e1631496985	379	}
root@mbed.org	0:5e1631496985	380	lpcb->callback_arg = pcb->callback_arg;
root@mbed.org	0:5e1631496985	381	lpcb->local_port = pcb->local_port;
root@mbed.org	0:5e1631496985	382	lpcb->state = LISTEN;
root@mbed.org	0:5e1631496985	383	lpcb->so_options = pcb->so_options;
root@mbed.org	0:5e1631496985	384	lpcb->so_options \|= SOF_ACCEPTCONN;
root@mbed.org	0:5e1631496985	385	lpcb->ttl = pcb->ttl;
root@mbed.org	0:5e1631496985	386	lpcb->tos = pcb->tos;
root@mbed.org	0:5e1631496985	387	ip_addr_set(&lpcb->local_ip, &pcb->local_ip);
root@mbed.org	0:5e1631496985	388	TCP_RMV(&tcp_bound_pcbs, pcb);
root@mbed.org	0:5e1631496985	389	memp_free(MEMP_TCP_PCB, pcb);
root@mbed.org	0:5e1631496985	390	#if LWIP_CALLBACK_API
root@mbed.org	0:5e1631496985	391	lpcb->accept = tcp_accept_null;
root@mbed.org	0:5e1631496985	392	#endif /* LWIP_CALLBACK_API */
root@mbed.org	0:5e1631496985	393	#if TCP_LISTEN_BACKLOG
root@mbed.org	0:5e1631496985	394	lpcb->accepts_pending = 0;
root@mbed.org	0:5e1631496985	395	lpcb->backlog = (backlog ? backlog : 1);
root@mbed.org	0:5e1631496985	396	#endif /* TCP_LISTEN_BACKLOG */
root@mbed.org	0:5e1631496985	397	TCP_REG(&tcp_listen_pcbs.listen_pcbs, lpcb);
root@mbed.org	0:5e1631496985	398	return (struct tcp_pcb *)lpcb;
root@mbed.org	0:5e1631496985	399	}
root@mbed.org	0:5e1631496985	400
root@mbed.org	0:5e1631496985	401	/**
root@mbed.org	0:5e1631496985	402	* Update the state that tracks the available window space to advertise.
root@mbed.org	0:5e1631496985	403	*
root@mbed.org	0:5e1631496985	404	* Returns how much extra window would be advertised if we sent an
root@mbed.org	0:5e1631496985	405	* update now.
root@mbed.org	0:5e1631496985	406	*/
root@mbed.org	0:5e1631496985	407	u32_t tcp_update_rcv_ann_wnd(struct tcp_pcb *pcb)
root@mbed.org	0:5e1631496985	408	{
root@mbed.org	0:5e1631496985	409	u32_t new_right_edge = pcb->rcv_nxt + pcb->rcv_wnd;
root@mbed.org	0:5e1631496985	410
root@mbed.org	0:5e1631496985	411	if (TCP_SEQ_GEQ(new_right_edge, pcb->rcv_ann_right_edge + LWIP_MIN((TCP_WND / 2), pcb->mss))) {
root@mbed.org	0:5e1631496985	412	/* we can advertise more window */
root@mbed.org	0:5e1631496985	413	pcb->rcv_ann_wnd = pcb->rcv_wnd;
root@mbed.org	0:5e1631496985	414	return new_right_edge - pcb->rcv_ann_right_edge;
root@mbed.org	0:5e1631496985	415	} else {
root@mbed.org	0:5e1631496985	416	if (TCP_SEQ_GT(pcb->rcv_nxt, pcb->rcv_ann_right_edge)) {
root@mbed.org	0:5e1631496985	417	/* Can happen due to other end sending out of advertised window,
root@mbed.org	0:5e1631496985	418	* but within actual available (but not yet advertised) window */
root@mbed.org	0:5e1631496985	419	pcb->rcv_ann_wnd = 0;
root@mbed.org	0:5e1631496985	420	} else {
root@mbed.org	0:5e1631496985	421	/* keep the right edge of window constant */
root@mbed.org	0:5e1631496985	422	pcb->rcv_ann_wnd = pcb->rcv_ann_right_edge - pcb->rcv_nxt;
root@mbed.org	0:5e1631496985	423	}
root@mbed.org	0:5e1631496985	424	return 0;
root@mbed.org	0:5e1631496985	425	}
root@mbed.org	0:5e1631496985	426	}
root@mbed.org	0:5e1631496985	427
root@mbed.org	0:5e1631496985	428	/**
root@mbed.org	0:5e1631496985	429	* This function should be called by the application when it has
root@mbed.org	0:5e1631496985	430	* processed the data. The purpose is to advertise a larger window
root@mbed.org	0:5e1631496985	431	* when the data has been processed.
root@mbed.org	0:5e1631496985	432	*
root@mbed.org	0:5e1631496985	433	* @param pcb the tcp_pcb for which data is read
root@mbed.org	0:5e1631496985	434	* @param len the amount of bytes that have been read by the application
root@mbed.org	0:5e1631496985	435	*/
root@mbed.org	0:5e1631496985	436	void
root@mbed.org	0:5e1631496985	437	tcp_recved(struct tcp_pcb *pcb, u16_t len)
root@mbed.org	0:5e1631496985	438	{
root@mbed.org	0:5e1631496985	439	int wnd_inflation;
root@mbed.org	0:5e1631496985	440
root@mbed.org	0:5e1631496985	441	LWIP_ASSERT("tcp_recved: len would wrap rcv_wnd\n",
root@mbed.org	0:5e1631496985	442	len <= 0xffff - pcb->rcv_wnd );
root@mbed.org	0:5e1631496985	443
root@mbed.org	0:5e1631496985	444	pcb->rcv_wnd += len;
root@mbed.org	0:5e1631496985	445	if (pcb->rcv_wnd > TCP_WND)
root@mbed.org	0:5e1631496985	446	pcb->rcv_wnd = TCP_WND;
root@mbed.org	0:5e1631496985	447
root@mbed.org	0:5e1631496985	448	wnd_inflation = tcp_update_rcv_ann_wnd(pcb);
root@mbed.org	0:5e1631496985	449
root@mbed.org	0:5e1631496985	450	/* If the change in the right edge of window is significant (default
root@mbed.org	0:5e1631496985	451	* watermark is TCP_WND/2), then send an explicit update now.
root@mbed.org	0:5e1631496985	452	* Otherwise wait for a packet to be sent in the normal course of
root@mbed.org	0:5e1631496985	453	* events (or more window to be available later) */
root@mbed.org	0:5e1631496985	454	if (wnd_inflation >= TCP_WND_UPDATE_THRESHOLD)
root@mbed.org	0:5e1631496985	455	tcp_ack_now(pcb);
root@mbed.org	0:5e1631496985	456
root@mbed.org	0:5e1631496985	457	LWIP_DEBUGF(TCP_DEBUG, ("tcp_recved: recveived %"U16_F" bytes, wnd %"U16_F" (%"U16_F").\n",
root@mbed.org	0:5e1631496985	458	len, pcb->rcv_wnd, TCP_WND - pcb->rcv_wnd));
root@mbed.org	0:5e1631496985	459	}
root@mbed.org	0:5e1631496985	460
root@mbed.org	0:5e1631496985	461	/**
root@mbed.org	0:5e1631496985	462	* A nastly hack featuring 'goto' statements that allocates a
root@mbed.org	0:5e1631496985	463	* new TCP local port.
root@mbed.org	0:5e1631496985	464	*
root@mbed.org	0:5e1631496985	465	* @return a new (free) local TCP port number
root@mbed.org	0:5e1631496985	466	*/
root@mbed.org	0:5e1631496985	467	static u16_t
root@mbed.org	0:5e1631496985	468	tcp_new_port(void)
root@mbed.org	0:5e1631496985	469	{
root@mbed.org	0:5e1631496985	470	struct tcp_pcb *pcb;
root@mbed.org	0:5e1631496985	471	#ifndef TCP_LOCAL_PORT_RANGE_START
root@mbed.org	0:5e1631496985	472	#define TCP_LOCAL_PORT_RANGE_START 4096
root@mbed.org	0:5e1631496985	473	#define TCP_LOCAL_PORT_RANGE_END 0x7fff
root@mbed.org	0:5e1631496985	474	#endif
root@mbed.org	0:5e1631496985	475	static u16_t port = TCP_LOCAL_PORT_RANGE_START;
root@mbed.org	0:5e1631496985	476
root@mbed.org	0:5e1631496985	477	again:
root@mbed.org	0:5e1631496985	478	if (++port > TCP_LOCAL_PORT_RANGE_END) {
root@mbed.org	0:5e1631496985	479	port = TCP_LOCAL_PORT_RANGE_START;
root@mbed.org	0:5e1631496985	480	}
root@mbed.org	0:5e1631496985	481
root@mbed.org	0:5e1631496985	482	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
root@mbed.org	0:5e1631496985	483	if (pcb->local_port == port) {
root@mbed.org	0:5e1631496985	484	goto again;
root@mbed.org	0:5e1631496985	485	}
root@mbed.org	0:5e1631496985	486	}
root@mbed.org	0:5e1631496985	487	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
root@mbed.org	0:5e1631496985	488	if (pcb->local_port == port) {
root@mbed.org	0:5e1631496985	489	goto again;
root@mbed.org	0:5e1631496985	490	}
root@mbed.org	0:5e1631496985	491	}
root@mbed.org	0:5e1631496985	492	for(pcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs; pcb != NULL; pcb = pcb->next) {
root@mbed.org	0:5e1631496985	493	if (pcb->local_port == port) {
root@mbed.org	0:5e1631496985	494	goto again;
root@mbed.org	0:5e1631496985	495	}
root@mbed.org	0:5e1631496985	496	}
root@mbed.org	0:5e1631496985	497	return port;
root@mbed.org	0:5e1631496985	498	}
root@mbed.org	0:5e1631496985	499
root@mbed.org	0:5e1631496985	500	/**
root@mbed.org	0:5e1631496985	501	* Connects to another host. The function given as the "connected"
root@mbed.org	0:5e1631496985	502	* argument will be called when the connection has been established.
root@mbed.org	0:5e1631496985	503	*
root@mbed.org	0:5e1631496985	504	* @param pcb the tcp_pcb used to establish the connection
root@mbed.org	0:5e1631496985	505	* @param ipaddr the remote ip address to connect to
root@mbed.org	0:5e1631496985	506	* @param port the remote tcp port to connect to
root@mbed.org	0:5e1631496985	507	* @param connected callback function to call when connected (or on error)
root@mbed.org	0:5e1631496985	508	* @return ERR_VAL if invalid arguments are given
root@mbed.org	0:5e1631496985	509	* ERR_OK if connect request has been sent
root@mbed.org	0:5e1631496985	510	* other err_t values if connect request couldn't be sent
root@mbed.org	0:5e1631496985	511	*/
root@mbed.org	0:5e1631496985	512	err_t
root@mbed.org	0:5e1631496985	513	tcp_connect(struct tcp_pcb pcb, struct ip_addr ipaddr, u16_t port,
root@mbed.org	0:5e1631496985	514	err_t (* connected)(void arg, struct tcp_pcb tpcb, err_t err))
root@mbed.org	0:5e1631496985	515	{
root@mbed.org	0:5e1631496985	516	err_t ret;
root@mbed.org	0:5e1631496985	517	u32_t iss;
root@mbed.org	0:5e1631496985	518
root@mbed.org	0:5e1631496985	519	LWIP_ERROR("tcp_connect: can only connected from state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
root@mbed.org	0:5e1631496985	520
root@mbed.org	0:5e1631496985	521	LWIP_DEBUGF(TCP_DEBUG, ("tcp_connect to port %"U16_F"\n", port));
root@mbed.org	0:5e1631496985	522	if (ipaddr != NULL) {
root@mbed.org	0:5e1631496985	523	pcb->remote_ip = *ipaddr;
root@mbed.org	0:5e1631496985	524	} else {
root@mbed.org	0:5e1631496985	525	return ERR_VAL;
root@mbed.org	0:5e1631496985	526	}
root@mbed.org	0:5e1631496985	527	pcb->remote_port = port;
root@mbed.org	0:5e1631496985	528	if (pcb->local_port == 0) {
root@mbed.org	0:5e1631496985	529	pcb->local_port = tcp_new_port();
root@mbed.org	0:5e1631496985	530	}
root@mbed.org	0:5e1631496985	531	iss = tcp_next_iss();
root@mbed.org	0:5e1631496985	532	pcb->rcv_nxt = 0;
root@mbed.org	0:5e1631496985	533	pcb->snd_nxt = iss;
root@mbed.org	0:5e1631496985	534	pcb->lastack = iss - 1;
root@mbed.org	0:5e1631496985	535	pcb->snd_lbb = iss - 1;
root@mbed.org	0:5e1631496985	536	pcb->rcv_wnd = TCP_WND;
root@mbed.org	0:5e1631496985	537	pcb->rcv_ann_wnd = TCP_WND;
root@mbed.org	0:5e1631496985	538	pcb->rcv_ann_right_edge = pcb->rcv_nxt;
root@mbed.org	0:5e1631496985	539	pcb->snd_wnd = TCP_WND;
root@mbed.org	0:5e1631496985	540	/* As initial send MSS, we use TCP_MSS but limit it to 536.
root@mbed.org	0:5e1631496985	541	The send MSS is updated when an MSS option is received. */
root@mbed.org	0:5e1631496985	542	pcb->mss = (TCP_MSS > 536) ? 536 : TCP_MSS;
root@mbed.org	0:5e1631496985	543	#if TCP_CALCULATE_EFF_SEND_MSS
root@mbed.org	0:5e1631496985	544	pcb->mss = tcp_eff_send_mss(pcb->mss, ipaddr);
root@mbed.org	0:5e1631496985	545	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
root@mbed.org	0:5e1631496985	546	pcb->cwnd = 1;
root@mbed.org	0:5e1631496985	547	pcb->ssthresh = pcb->mss * 10;
root@mbed.org	0:5e1631496985	548	pcb->state = SYN_SENT;
root@mbed.org	0:5e1631496985	549	#if LWIP_CALLBACK_API
root@mbed.org	0:5e1631496985	550	pcb->connected = connected;
root@mbed.org	0:5e1631496985	551	#endif /* LWIP_CALLBACK_API */
root@mbed.org	0:5e1631496985	552	TCP_RMV(&tcp_bound_pcbs, pcb);
root@mbed.org	0:5e1631496985	553	TCP_REG(&tcp_active_pcbs, pcb);
root@mbed.org	0:5e1631496985	554
root@mbed.org	0:5e1631496985	555	snmp_inc_tcpactiveopens();
root@mbed.org	0:5e1631496985	556
root@mbed.org	0:5e1631496985	557	ret = tcp_enqueue(pcb, NULL, 0, TCP_SYN, 0, TF_SEG_OPTS_MSS
root@mbed.org	0:5e1631496985	558	#if LWIP_TCP_TIMESTAMPS
root@mbed.org	0:5e1631496985	559	\| TF_SEG_OPTS_TS
root@mbed.org	0:5e1631496985	560	#endif
root@mbed.org	0:5e1631496985	561	);
root@mbed.org	0:5e1631496985	562	if (ret == ERR_OK) {
root@mbed.org	0:5e1631496985	563	tcp_output(pcb);
root@mbed.org	0:5e1631496985	564	}
root@mbed.org	0:5e1631496985	565	return ret;
root@mbed.org	0:5e1631496985	566	}
root@mbed.org	0:5e1631496985	567
root@mbed.org	0:5e1631496985	568	/**
root@mbed.org	0:5e1631496985	569	* Called every 500 ms and implements the retransmission timer and the timer that
root@mbed.org	0:5e1631496985	570	* removes PCBs that have been in TIME-WAIT for enough time. It also increments
root@mbed.org	0:5e1631496985	571	* various timers such as the inactivity timer in each PCB.
root@mbed.org	0:5e1631496985	572	*
root@mbed.org	0:5e1631496985	573	* Automatically called from tcp_tmr().
root@mbed.org	0:5e1631496985	574	*/
root@mbed.org	0:5e1631496985	575	void
root@mbed.org	0:5e1631496985	576	tcp_slowtmr(void)
root@mbed.org	0:5e1631496985	577	{
root@mbed.org	0:5e1631496985	578	struct tcp_pcb pcb, pcb2, *prev;
root@mbed.org	0:5e1631496985	579	u16_t eff_wnd;
root@mbed.org	0:5e1631496985	580	u8_t pcb_remove; /* flag if a PCB should be removed */
root@mbed.org	0:5e1631496985	581	err_t err;
root@mbed.org	0:5e1631496985	582
root@mbed.org	0:5e1631496985	583	err = ERR_OK;
root@mbed.org	0:5e1631496985	584
root@mbed.org	0:5e1631496985	585	++tcp_ticks;
root@mbed.org	0:5e1631496985	586
root@mbed.org	0:5e1631496985	587	/* Steps through all of the active PCBs. */
root@mbed.org	0:5e1631496985	588	prev = NULL;
root@mbed.org	0:5e1631496985	589	pcb = tcp_active_pcbs;
root@mbed.org	0:5e1631496985	590	if (pcb == NULL) {
root@mbed.org	0:5e1631496985	591	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: no active pcbs\n"));
root@mbed.org	0:5e1631496985	592	}
root@mbed.org	0:5e1631496985	593	while (pcb != NULL) {
root@mbed.org	0:5e1631496985	594	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: processing active pcb\n"));
root@mbed.org	0:5e1631496985	595	LWIP_ASSERT("tcp_slowtmr: active pcb->state != CLOSED\n", pcb->state != CLOSED);
root@mbed.org	0:5e1631496985	596	LWIP_ASSERT("tcp_slowtmr: active pcb->state != LISTEN\n", pcb->state != LISTEN);
root@mbed.org	0:5e1631496985	597	LWIP_ASSERT("tcp_slowtmr: active pcb->state != TIME-WAIT\n", pcb->state != TIME_WAIT);
root@mbed.org	0:5e1631496985	598
root@mbed.org	0:5e1631496985	599	pcb_remove = 0;
root@mbed.org	0:5e1631496985	600
root@mbed.org	0:5e1631496985	601	if (pcb->state == SYN_SENT && pcb->nrtx == TCP_SYNMAXRTX) {
root@mbed.org	0:5e1631496985	602	++pcb_remove;
root@mbed.org	0:5e1631496985	603	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max SYN retries reached\n"));
root@mbed.org	0:5e1631496985	604	}
root@mbed.org	0:5e1631496985	605	else if (pcb->nrtx == TCP_MAXRTX) {
root@mbed.org	0:5e1631496985	606	++pcb_remove;
root@mbed.org	0:5e1631496985	607	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max DATA retries reached\n"));
root@mbed.org	0:5e1631496985	608	} else {
root@mbed.org	0:5e1631496985	609	if (pcb->persist_backoff > 0) {
root@mbed.org	0:5e1631496985	610	/* If snd_wnd is zero, use persist timer to send 1 byte probes
root@mbed.org	0:5e1631496985	611	* instead of using the standard retransmission mechanism. */
root@mbed.org	0:5e1631496985	612	pcb->persist_cnt++;
root@mbed.org	0:5e1631496985	613	if (pcb->persist_cnt >= tcp_persist_backoff[pcb->persist_backoff-1]) {
root@mbed.org	0:5e1631496985	614	pcb->persist_cnt = 0;
root@mbed.org	0:5e1631496985	615	if (pcb->persist_backoff < sizeof(tcp_persist_backoff)) {
root@mbed.org	0:5e1631496985	616	pcb->persist_backoff++;
root@mbed.org	0:5e1631496985	617	}
root@mbed.org	0:5e1631496985	618	tcp_zero_window_probe(pcb);
root@mbed.org	0:5e1631496985	619	}
root@mbed.org	0:5e1631496985	620	} else {
root@mbed.org	0:5e1631496985	621	/* Increase the retransmission timer if it is running */
root@mbed.org	0:5e1631496985	622	if(pcb->rtime >= 0)
root@mbed.org	0:5e1631496985	623	++pcb->rtime;
root@mbed.org	0:5e1631496985	624
root@mbed.org	0:5e1631496985	625	if (pcb->unacked != NULL && pcb->rtime >= pcb->rto) {
root@mbed.org	0:5e1631496985	626	/* Time for a retransmission. */
root@mbed.org	0:5e1631496985	627	LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_slowtmr: rtime %"S16_F
root@mbed.org	0:5e1631496985	628	" pcb->rto %"S16_F"\n",
root@mbed.org	0:5e1631496985	629	pcb->rtime, pcb->rto));
root@mbed.org	0:5e1631496985	630
root@mbed.org	0:5e1631496985	631	/* Double retransmission time-out unless we are trying to
root@mbed.org	0:5e1631496985	632	* connect to somebody (i.e., we are in SYN_SENT). */
root@mbed.org	0:5e1631496985	633	if (pcb->state != SYN_SENT) {
root@mbed.org	0:5e1631496985	634	pcb->rto = ((pcb->sa >> 3) + pcb->sv) << tcp_backoff[pcb->nrtx];
root@mbed.org	0:5e1631496985	635	}
root@mbed.org	0:5e1631496985	636
root@mbed.org	0:5e1631496985	637	/* Reset the retransmission timer. */
root@mbed.org	0:5e1631496985	638	pcb->rtime = 0;
root@mbed.org	0:5e1631496985	639
root@mbed.org	0:5e1631496985	640	/* Reduce congestion window and ssthresh. */
root@mbed.org	0:5e1631496985	641	eff_wnd = LWIP_MIN(pcb->cwnd, pcb->snd_wnd);
root@mbed.org	0:5e1631496985	642	pcb->ssthresh = eff_wnd >> 1;
root@mbed.org	0:5e1631496985	643	if (pcb->ssthresh < pcb->mss) {
root@mbed.org	0:5e1631496985	644	pcb->ssthresh = pcb->mss * 2;
root@mbed.org	0:5e1631496985	645	}
root@mbed.org	0:5e1631496985	646	pcb->cwnd = pcb->mss;
root@mbed.org	0:5e1631496985	647	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: cwnd %"U16_F
root@mbed.org	0:5e1631496985	648	" ssthresh %"U16_F"\n",
root@mbed.org	0:5e1631496985	649	pcb->cwnd, pcb->ssthresh));
root@mbed.org	0:5e1631496985	650
root@mbed.org	0:5e1631496985	651	/* The following needs to be called AFTER cwnd is set to one
root@mbed.org	0:5e1631496985	652	mss - STJ */
root@mbed.org	0:5e1631496985	653	tcp_rexmit_rto(pcb);
root@mbed.org	0:5e1631496985	654	}
root@mbed.org	0:5e1631496985	655	}
root@mbed.org	0:5e1631496985	656	}
root@mbed.org	0:5e1631496985	657	/* Check if this PCB has stayed too long in FIN-WAIT-2 */
root@mbed.org	0:5e1631496985	658	if (pcb->state == FIN_WAIT_2) {
root@mbed.org	0:5e1631496985	659	if ((u32_t)(tcp_ticks - pcb->tmr) >
root@mbed.org	0:5e1631496985	660	TCP_FIN_WAIT_TIMEOUT / TCP_SLOW_INTERVAL) {
root@mbed.org	0:5e1631496985	661	++pcb_remove;
root@mbed.org	0:5e1631496985	662	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in FIN-WAIT-2\n"));
root@mbed.org	0:5e1631496985	663	}
root@mbed.org	0:5e1631496985	664	}
root@mbed.org	0:5e1631496985	665
root@mbed.org	0:5e1631496985	666	/* Check if KEEPALIVE should be sent */
root@mbed.org	0:5e1631496985	667	if((pcb->so_options & SOF_KEEPALIVE) &&
root@mbed.org	0:5e1631496985	668	((pcb->state == ESTABLISHED) \|\|
root@mbed.org	0:5e1631496985	669	(pcb->state == CLOSE_WAIT))) {
root@mbed.org	0:5e1631496985	670	#if LWIP_TCP_KEEPALIVE
root@mbed.org	0:5e1631496985	671	if((u32_t)(tcp_ticks - pcb->tmr) >
root@mbed.org	0:5e1631496985	672	(pcb->keep_idle + (pcb->keep_cnt*pcb->keep_intvl))
root@mbed.org	0:5e1631496985	673	/ TCP_SLOW_INTERVAL)
root@mbed.org	0:5e1631496985	674	#else
root@mbed.org	0:5e1631496985	675	if((u32_t)(tcp_ticks - pcb->tmr) >
root@mbed.org	0:5e1631496985	676	(pcb->keep_idle + TCP_MAXIDLE) / TCP_SLOW_INTERVAL)
root@mbed.org	0:5e1631496985	677	#endif /* LWIP_TCP_KEEPALIVE */
root@mbed.org	0:5e1631496985	678	{
root@mbed.org	0:5e1631496985	679	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: KEEPALIVE timeout. Aborting connection to %"U16_F".%"U16_F".%"U16_F".%"U16_F".\n",
root@mbed.org	0:5e1631496985	680	ip4_addr1(&pcb->remote_ip), ip4_addr2(&pcb->remote_ip),
root@mbed.org	0:5e1631496985	681	ip4_addr3(&pcb->remote_ip), ip4_addr4(&pcb->remote_ip)));
root@mbed.org	0:5e1631496985	682
root@mbed.org	0:5e1631496985	683	tcp_abort(pcb);
root@mbed.org	0:5e1631496985	684	}
root@mbed.org	0:5e1631496985	685	#if LWIP_TCP_KEEPALIVE
root@mbed.org	0:5e1631496985	686	else if((u32_t)(tcp_ticks - pcb->tmr) >
root@mbed.org	0:5e1631496985	687	(pcb->keep_idle + pcb->keep_cnt_sent * pcb->keep_intvl)
root@mbed.org	0:5e1631496985	688	/ TCP_SLOW_INTERVAL)
root@mbed.org	0:5e1631496985	689	#else
root@mbed.org	0:5e1631496985	690	else if((u32_t)(tcp_ticks - pcb->tmr) >
root@mbed.org	0:5e1631496985	691	(pcb->keep_idle + pcb->keep_cnt_sent * TCP_KEEPINTVL_DEFAULT)
root@mbed.org	0:5e1631496985	692	/ TCP_SLOW_INTERVAL)
root@mbed.org	0:5e1631496985	693	#endif /* LWIP_TCP_KEEPALIVE */
root@mbed.org	0:5e1631496985	694	{
root@mbed.org	0:5e1631496985	695	tcp_keepalive(pcb);
root@mbed.org	0:5e1631496985	696	pcb->keep_cnt_sent++;
root@mbed.org	0:5e1631496985	697	}
root@mbed.org	0:5e1631496985	698	}
root@mbed.org	0:5e1631496985	699
root@mbed.org	0:5e1631496985	700	/* If this PCB has queued out of sequence data, but has been
root@mbed.org	0:5e1631496985	701	inactive for too long, will drop the data (it will eventually
root@mbed.org	0:5e1631496985	702	be retransmitted). */
root@mbed.org	0:5e1631496985	703	#if TCP_QUEUE_OOSEQ
root@mbed.org	0:5e1631496985	704	if (pcb->ooseq != NULL &&
root@mbed.org	0:5e1631496985	705	(u32_t)tcp_ticks - pcb->tmr >= pcb->rto * TCP_OOSEQ_TIMEOUT) {
root@mbed.org	0:5e1631496985	706	tcp_segs_free(pcb->ooseq);
root@mbed.org	0:5e1631496985	707	pcb->ooseq = NULL;
root@mbed.org	0:5e1631496985	708	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: dropping OOSEQ queued data\n"));
root@mbed.org	0:5e1631496985	709	}
root@mbed.org	0:5e1631496985	710	#endif /* TCP_QUEUE_OOSEQ */
root@mbed.org	0:5e1631496985	711
root@mbed.org	0:5e1631496985	712	/* Check if this PCB has stayed too long in SYN-RCVD */
root@mbed.org	0:5e1631496985	713	if (pcb->state == SYN_RCVD) {
root@mbed.org	0:5e1631496985	714	if ((u32_t)(tcp_ticks - pcb->tmr) >
root@mbed.org	0:5e1631496985	715	TCP_SYN_RCVD_TIMEOUT / TCP_SLOW_INTERVAL) {
root@mbed.org	0:5e1631496985	716	++pcb_remove;
root@mbed.org	0:5e1631496985	717	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in SYN-RCVD\n"));
root@mbed.org	0:5e1631496985	718	}
root@mbed.org	0:5e1631496985	719	}
root@mbed.org	0:5e1631496985	720
root@mbed.org	0:5e1631496985	721	/* Check if this PCB has stayed too long in LAST-ACK */
root@mbed.org	0:5e1631496985	722	if (pcb->state == LAST_ACK) {
root@mbed.org	0:5e1631496985	723	if ((u32_t)(tcp_ticks - pcb->tmr) > 2 * TCP_MSL / TCP_SLOW_INTERVAL) {
root@mbed.org	0:5e1631496985	724	++pcb_remove;
root@mbed.org	0:5e1631496985	725	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in LAST-ACK\n"));
root@mbed.org	0:5e1631496985	726	}
root@mbed.org	0:5e1631496985	727	}
root@mbed.org	0:5e1631496985	728
root@mbed.org	0:5e1631496985	729	/* If the PCB should be removed, do it. */
root@mbed.org	0:5e1631496985	730	if (pcb_remove) {
root@mbed.org	0:5e1631496985	731	tcp_pcb_purge(pcb);
root@mbed.org	0:5e1631496985	732	/* Remove PCB from tcp_active_pcbs list. */
root@mbed.org	0:5e1631496985	733	if (prev != NULL) {
root@mbed.org	0:5e1631496985	734	LWIP_ASSERT("tcp_slowtmr: middle tcp != tcp_active_pcbs", pcb != tcp_active_pcbs);
root@mbed.org	0:5e1631496985	735	prev->next = pcb->next;
root@mbed.org	0:5e1631496985	736	} else {
root@mbed.org	0:5e1631496985	737	/* This PCB was the first. */
root@mbed.org	0:5e1631496985	738	LWIP_ASSERT("tcp_slowtmr: first pcb == tcp_active_pcbs", tcp_active_pcbs == pcb);
root@mbed.org	0:5e1631496985	739	tcp_active_pcbs = pcb->next;
root@mbed.org	0:5e1631496985	740	}
root@mbed.org	0:5e1631496985	741
root@mbed.org	0:5e1631496985	742	TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_ABRT);
root@mbed.org	0:5e1631496985	743
root@mbed.org	0:5e1631496985	744	pcb2 = pcb->next;
root@mbed.org	0:5e1631496985	745	memp_free(MEMP_TCP_PCB, pcb);
root@mbed.org	0:5e1631496985	746	pcb = pcb2;
root@mbed.org	0:5e1631496985	747	} else {
root@mbed.org	0:5e1631496985	748
root@mbed.org	0:5e1631496985	749	/* We check if we should poll the connection. */
root@mbed.org	0:5e1631496985	750	++pcb->polltmr;
root@mbed.org	0:5e1631496985	751	if (pcb->polltmr >= pcb->pollinterval) {
root@mbed.org	0:5e1631496985	752	pcb->polltmr = 0;
root@mbed.org	0:5e1631496985	753	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: polling application\n"));
root@mbed.org	0:5e1631496985	754	TCP_EVENT_POLL(pcb, err);
root@mbed.org	0:5e1631496985	755	if (err == ERR_OK) {
root@mbed.org	0:5e1631496985	756	tcp_output(pcb);
root@mbed.org	0:5e1631496985	757	}
root@mbed.org	0:5e1631496985	758	}
root@mbed.org	0:5e1631496985	759
root@mbed.org	0:5e1631496985	760	prev = pcb;
root@mbed.org	0:5e1631496985	761	pcb = pcb->next;
root@mbed.org	0:5e1631496985	762	}
root@mbed.org	0:5e1631496985	763	}
root@mbed.org	0:5e1631496985	764
root@mbed.org	0:5e1631496985	765
root@mbed.org	0:5e1631496985	766	/* Steps through all of the TIME-WAIT PCBs. */
root@mbed.org	0:5e1631496985	767	prev = NULL;
root@mbed.org	0:5e1631496985	768	pcb = tcp_tw_pcbs;
root@mbed.org	0:5e1631496985	769	while (pcb != NULL) {
root@mbed.org	0:5e1631496985	770	LWIP_ASSERT("tcp_slowtmr: TIME-WAIT pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
root@mbed.org	0:5e1631496985	771	pcb_remove = 0;
root@mbed.org	0:5e1631496985	772
root@mbed.org	0:5e1631496985	773	/* Check if this PCB has stayed long enough in TIME-WAIT */
root@mbed.org	0:5e1631496985	774	if ((u32_t)(tcp_ticks - pcb->tmr) > 2 * TCP_MSL / TCP_SLOW_INTERVAL) {
root@mbed.org	0:5e1631496985	775	++pcb_remove;
root@mbed.org	0:5e1631496985	776	}
root@mbed.org	0:5e1631496985	777
root@mbed.org	0:5e1631496985	778
root@mbed.org	0:5e1631496985	779
root@mbed.org	0:5e1631496985	780	/* If the PCB should be removed, do it. */
root@mbed.org	0:5e1631496985	781	if (pcb_remove) {
root@mbed.org	0:5e1631496985	782	tcp_pcb_purge(pcb);
root@mbed.org	0:5e1631496985	783	/* Remove PCB from tcp_tw_pcbs list. */
root@mbed.org	0:5e1631496985	784	if (prev != NULL) {
root@mbed.org	0:5e1631496985	785	LWIP_ASSERT("tcp_slowtmr: middle tcp != tcp_tw_pcbs", pcb != tcp_tw_pcbs);
root@mbed.org	0:5e1631496985	786	prev->next = pcb->next;
root@mbed.org	0:5e1631496985	787	} else {
root@mbed.org	0:5e1631496985	788	/* This PCB was the first. */
root@mbed.org	0:5e1631496985	789	LWIP_ASSERT("tcp_slowtmr: first pcb == tcp_tw_pcbs", tcp_tw_pcbs == pcb);
root@mbed.org	0:5e1631496985	790	tcp_tw_pcbs = pcb->next;
root@mbed.org	0:5e1631496985	791	}
root@mbed.org	0:5e1631496985	792	pcb2 = pcb->next;
root@mbed.org	0:5e1631496985	793	memp_free(MEMP_TCP_PCB, pcb);
root@mbed.org	0:5e1631496985	794	pcb = pcb2;
root@mbed.org	0:5e1631496985	795	} else {
root@mbed.org	0:5e1631496985	796	prev = pcb;
root@mbed.org	0:5e1631496985	797	pcb = pcb->next;
root@mbed.org	0:5e1631496985	798	}
root@mbed.org	0:5e1631496985	799	}
root@mbed.org	0:5e1631496985	800	}
root@mbed.org	0:5e1631496985	801
root@mbed.org	0:5e1631496985	802	/**
root@mbed.org	0:5e1631496985	803	* Is called every TCP_FAST_INTERVAL (250 ms) and process data previously
root@mbed.org	0:5e1631496985	804	* "refused" by upper layer (application) and sends delayed ACKs.
root@mbed.org	0:5e1631496985	805	*
root@mbed.org	0:5e1631496985	806	* Automatically called from tcp_tmr().
root@mbed.org	0:5e1631496985	807	*/
root@mbed.org	0:5e1631496985	808	void
root@mbed.org	0:5e1631496985	809	tcp_fasttmr(void)
root@mbed.org	0:5e1631496985	810	{
root@mbed.org	0:5e1631496985	811	struct tcp_pcb *pcb;
root@mbed.org	0:5e1631496985	812
root@mbed.org	0:5e1631496985	813	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
root@mbed.org	0:5e1631496985	814	/* If there is data which was previously "refused" by upper layer */
root@mbed.org	0:5e1631496985	815	if (pcb->refused_data != NULL) {
root@mbed.org	0:5e1631496985	816	/* Notify again application with data previously received. */
root@mbed.org	0:5e1631496985	817	err_t err;
root@mbed.org	0:5e1631496985	818	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_fasttmr: notify kept packet\n"));
root@mbed.org	0:5e1631496985	819	TCP_EVENT_RECV(pcb, pcb->refused_data, ERR_OK, err);
root@mbed.org	0:5e1631496985	820	if (err == ERR_OK) {
root@mbed.org	0:5e1631496985	821	pcb->refused_data = NULL;
root@mbed.org	0:5e1631496985	822	}
root@mbed.org	0:5e1631496985	823	}
root@mbed.org	0:5e1631496985	824
root@mbed.org	0:5e1631496985	825	/* send delayed ACKs */
root@mbed.org	0:5e1631496985	826	if (pcb->flags & TF_ACK_DELAY) {
root@mbed.org	0:5e1631496985	827	LWIP_DEBUGF(TCP_DEBUG, ("tcp_fasttmr: delayed ACK\n"));
root@mbed.org	0:5e1631496985	828	tcp_ack_now(pcb);
root@mbed.org	0:5e1631496985	829	pcb->flags &= ~(TF_ACK_DELAY \| TF_ACK_NOW);
root@mbed.org	0:5e1631496985	830	}
root@mbed.org	0:5e1631496985	831	}
root@mbed.org	0:5e1631496985	832	}
root@mbed.org	0:5e1631496985	833
root@mbed.org	0:5e1631496985	834	/**
root@mbed.org	0:5e1631496985	835	* Deallocates a list of TCP segments (tcp_seg structures).
root@mbed.org	0:5e1631496985	836	*
root@mbed.org	0:5e1631496985	837	* @param seg tcp_seg list of TCP segments to free
root@mbed.org	0:5e1631496985	838	* @return the number of pbufs that were deallocated
root@mbed.org	0:5e1631496985	839	*/
root@mbed.org	0:5e1631496985	840	u8_t
root@mbed.org	0:5e1631496985	841	tcp_segs_free(struct tcp_seg *seg)
root@mbed.org	0:5e1631496985	842	{
root@mbed.org	0:5e1631496985	843	u8_t count = 0;
root@mbed.org	0:5e1631496985	844	struct tcp_seg *next;
root@mbed.org	0:5e1631496985	845	while (seg != NULL) {
root@mbed.org	0:5e1631496985	846	next = seg->next;
root@mbed.org	0:5e1631496985	847	count += tcp_seg_free(seg);
root@mbed.org	0:5e1631496985	848	seg = next;
root@mbed.org	0:5e1631496985	849	}
root@mbed.org	0:5e1631496985	850	return count;
root@mbed.org	0:5e1631496985	851	}
root@mbed.org	0:5e1631496985	852
root@mbed.org	0:5e1631496985	853	/**
root@mbed.org	0:5e1631496985	854	* Frees a TCP segment (tcp_seg structure).
root@mbed.org	0:5e1631496985	855	*
root@mbed.org	0:5e1631496985	856	* @param seg single tcp_seg to free
root@mbed.org	0:5e1631496985	857	* @return the number of pbufs that were deallocated
root@mbed.org	0:5e1631496985	858	*/
root@mbed.org	0:5e1631496985	859	u8_t
root@mbed.org	0:5e1631496985	860	tcp_seg_free(struct tcp_seg *seg)
root@mbed.org	0:5e1631496985	861	{
root@mbed.org	0:5e1631496985	862	u8_t count = 0;
root@mbed.org	0:5e1631496985	863
root@mbed.org	0:5e1631496985	864	if (seg != NULL) {
root@mbed.org	0:5e1631496985	865	if (seg->p != NULL) {
root@mbed.org	0:5e1631496985	866	count = pbuf_free(seg->p);
root@mbed.org	0:5e1631496985	867	#if TCP_DEBUG
root@mbed.org	0:5e1631496985	868	seg->p = NULL;
root@mbed.org	0:5e1631496985	869	#endif /* TCP_DEBUG */
root@mbed.org	0:5e1631496985	870	}
root@mbed.org	0:5e1631496985	871	memp_free(MEMP_TCP_SEG, seg);
root@mbed.org	0:5e1631496985	872	}
root@mbed.org	0:5e1631496985	873	return count;
root@mbed.org	0:5e1631496985	874	}
root@mbed.org	0:5e1631496985	875
root@mbed.org	0:5e1631496985	876	/**
root@mbed.org	0:5e1631496985	877	* Sets the priority of a connection.
root@mbed.org	0:5e1631496985	878	*
root@mbed.org	0:5e1631496985	879	* @param pcb the tcp_pcb to manipulate
root@mbed.org	0:5e1631496985	880	* @param prio new priority
root@mbed.org	0:5e1631496985	881	*/
root@mbed.org	0:5e1631496985	882	void
root@mbed.org	0:5e1631496985	883	tcp_setprio(struct tcp_pcb *pcb, u8_t prio)
root@mbed.org	0:5e1631496985	884	{
root@mbed.org	0:5e1631496985	885	pcb->prio = prio;
root@mbed.org	0:5e1631496985	886	}
root@mbed.org	0:5e1631496985	887	#if TCP_QUEUE_OOSEQ
root@mbed.org	0:5e1631496985	888
root@mbed.org	0:5e1631496985	889	/**
root@mbed.org	0:5e1631496985	890	* Returns a copy of the given TCP segment.
root@mbed.org	0:5e1631496985	891	* The pbuf and data are not copied, only the pointers
root@mbed.org	0:5e1631496985	892	*
root@mbed.org	0:5e1631496985	893	* @param seg the old tcp_seg
root@mbed.org	0:5e1631496985	894	* @return a copy of seg
root@mbed.org	0:5e1631496985	895	*/
root@mbed.org	0:5e1631496985	896	struct tcp_seg *
root@mbed.org	0:5e1631496985	897	tcp_seg_copy(struct tcp_seg *seg)
root@mbed.org	0:5e1631496985	898	{
root@mbed.org	0:5e1631496985	899	struct tcp_seg *cseg;
root@mbed.org	0:5e1631496985	900
root@mbed.org	0:5e1631496985	901	cseg = (struct tcp_seg *)memp_malloc(MEMP_TCP_SEG);
root@mbed.org	0:5e1631496985	902	if (cseg == NULL) {
root@mbed.org	0:5e1631496985	903	return NULL;
root@mbed.org	0:5e1631496985	904	}
root@mbed.org	0:5e1631496985	905	SMEMCPY((u8_t )cseg, (const u8_t )seg, sizeof(struct tcp_seg));
root@mbed.org	0:5e1631496985	906	pbuf_ref(cseg->p);
root@mbed.org	0:5e1631496985	907	return cseg;
root@mbed.org	0:5e1631496985	908	}
root@mbed.org	0:5e1631496985	909	#endif
root@mbed.org	0:5e1631496985	910
root@mbed.org	0:5e1631496985	911	#if LWIP_CALLBACK_API
root@mbed.org	0:5e1631496985	912	/**
root@mbed.org	0:5e1631496985	913	* Default receive callback that is called if the user didn't register
root@mbed.org	0:5e1631496985	914	* a recv callback for the pcb.
root@mbed.org	0:5e1631496985	915	*/
root@mbed.org	0:5e1631496985	916	static err_t
root@mbed.org	0:5e1631496985	917	tcp_recv_null(void arg, struct tcp_pcb pcb, struct pbuf *p, err_t err)
root@mbed.org	0:5e1631496985	918	{
root@mbed.org	0:5e1631496985	919	arg = arg;
root@mbed.org	0:5e1631496985	920	if (p != NULL) {
root@mbed.org	0:5e1631496985	921	pbuf_free(p);
root@mbed.org	0:5e1631496985	922	} else if (err == ERR_OK) {
root@mbed.org	0:5e1631496985	923	return tcp_close(pcb);
root@mbed.org	0:5e1631496985	924	}
root@mbed.org	0:5e1631496985	925	return ERR_OK;
root@mbed.org	0:5e1631496985	926	}
root@mbed.org	0:5e1631496985	927	#endif /* LWIP_CALLBACK_API */
root@mbed.org	0:5e1631496985	928
root@mbed.org	0:5e1631496985	929	/**
root@mbed.org	0:5e1631496985	930	* Kills the oldest active connection that has lower priority than prio.
root@mbed.org	0:5e1631496985	931	*
root@mbed.org	0:5e1631496985	932	* @param prio minimum priority
root@mbed.org	0:5e1631496985	933	*/
root@mbed.org	0:5e1631496985	934	static void
root@mbed.org	0:5e1631496985	935	tcp_kill_prio(u8_t prio)
root@mbed.org	0:5e1631496985	936	{
root@mbed.org	0:5e1631496985	937	struct tcp_pcb pcb, inactive;
root@mbed.org	0:5e1631496985	938	u32_t inactivity;
root@mbed.org	0:5e1631496985	939	u8_t mprio;
root@mbed.org	0:5e1631496985	940
root@mbed.org	0:5e1631496985	941
root@mbed.org	0:5e1631496985	942	mprio = TCP_PRIO_MAX;
root@mbed.org	0:5e1631496985	943
root@mbed.org	0:5e1631496985	944	/* We kill the oldest active connection that has lower priority than prio. */
root@mbed.org	0:5e1631496985	945	inactivity = 0;
root@mbed.org	0:5e1631496985	946	inactive = NULL;
root@mbed.org	0:5e1631496985	947	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
root@mbed.org	0:5e1631496985	948	if (pcb->prio <= prio &&
root@mbed.org	0:5e1631496985	949	pcb->prio <= mprio &&
root@mbed.org	0:5e1631496985	950	(u32_t)(tcp_ticks - pcb->tmr) >= inactivity) {
root@mbed.org	0:5e1631496985	951	inactivity = tcp_ticks - pcb->tmr;
root@mbed.org	0:5e1631496985	952	inactive = pcb;
root@mbed.org	0:5e1631496985	953	mprio = pcb->prio;
root@mbed.org	0:5e1631496985	954	}
root@mbed.org	0:5e1631496985	955	}
root@mbed.org	0:5e1631496985	956	if (inactive != NULL) {
root@mbed.org	0:5e1631496985	957	LWIP_DEBUGF(TCP_DEBUG, ("tcp_kill_prio: killing oldest PCB %p (%"S32_F")\n",
root@mbed.org	0:5e1631496985	958	(void *)inactive, inactivity));
root@mbed.org	0:5e1631496985	959	tcp_abort(inactive);
root@mbed.org	0:5e1631496985	960	}
root@mbed.org	0:5e1631496985	961	}
root@mbed.org	0:5e1631496985	962
root@mbed.org	0:5e1631496985	963	/**
root@mbed.org	0:5e1631496985	964	* Kills the oldest connection that is in TIME_WAIT state.
root@mbed.org	0:5e1631496985	965	* Called from tcp_alloc() if no more connections are available.
root@mbed.org	0:5e1631496985	966	*/
root@mbed.org	0:5e1631496985	967	static void
root@mbed.org	0:5e1631496985	968	tcp_kill_timewait(void)
root@mbed.org	0:5e1631496985	969	{
root@mbed.org	0:5e1631496985	970	struct tcp_pcb pcb, inactive;
root@mbed.org	0:5e1631496985	971	u32_t inactivity;
root@mbed.org	0:5e1631496985	972
root@mbed.org	0:5e1631496985	973	inactivity = 0;
root@mbed.org	0:5e1631496985	974	inactive = NULL;
root@mbed.org	0:5e1631496985	975	/* Go through the list of TIME_WAIT pcbs and get the oldest pcb. */
root@mbed.org	0:5e1631496985	976	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
root@mbed.org	0:5e1631496985	977	if ((u32_t)(tcp_ticks - pcb->tmr) >= inactivity) {
root@mbed.org	0:5e1631496985	978	inactivity = tcp_ticks - pcb->tmr;
root@mbed.org	0:5e1631496985	979	inactive = pcb;
root@mbed.org	0:5e1631496985	980	}
root@mbed.org	0:5e1631496985	981	}
root@mbed.org	0:5e1631496985	982	if (inactive != NULL) {
root@mbed.org	0:5e1631496985	983	LWIP_DEBUGF(TCP_DEBUG, ("tcp_kill_timewait: killing oldest TIME-WAIT PCB %p (%"S32_F")\n",
root@mbed.org	0:5e1631496985	984	(void *)inactive, inactivity));
root@mbed.org	0:5e1631496985	985	tcp_abort(inactive);
root@mbed.org	0:5e1631496985	986	}
root@mbed.org	0:5e1631496985	987	}
root@mbed.org	0:5e1631496985	988
root@mbed.org	0:5e1631496985	989	/**
root@mbed.org	0:5e1631496985	990	* Allocate a new tcp_pcb structure.
root@mbed.org	0:5e1631496985	991	*
root@mbed.org	0:5e1631496985	992	* @param prio priority for the new pcb
root@mbed.org	0:5e1631496985	993	* @return a new tcp_pcb that initially is in state CLOSED
root@mbed.org	0:5e1631496985	994	*/
root@mbed.org	0:5e1631496985	995	struct tcp_pcb *
root@mbed.org	0:5e1631496985	996	tcp_alloc(u8_t prio)
root@mbed.org	0:5e1631496985	997	{
root@mbed.org	0:5e1631496985	998	struct tcp_pcb *pcb;
root@mbed.org	0:5e1631496985	999	u32_t iss;
root@mbed.org	0:5e1631496985	1000
root@mbed.org	0:5e1631496985	1001	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
root@mbed.org	0:5e1631496985	1002	if (pcb == NULL) {
root@mbed.org	0:5e1631496985	1003	/* Try killing oldest connection in TIME-WAIT. */
root@mbed.org	0:5e1631496985	1004	LWIP_DEBUGF(TCP_DEBUG, ("tcp_alloc: killing off oldest TIME-WAIT connection\n"));
root@mbed.org	0:5e1631496985	1005	tcp_kill_timewait();
root@mbed.org	0:5e1631496985	1006	/* Try to allocate a tcp_pcb again. */
root@mbed.org	0:5e1631496985	1007	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
root@mbed.org	0:5e1631496985	1008	if (pcb == NULL) {
root@mbed.org	0:5e1631496985	1009	/* Try killing active connections with lower priority than the new one. */
root@mbed.org	0:5e1631496985	1010	tcp_kill_prio(prio);
root@mbed.org	0:5e1631496985	1011	/* Try to allocate a tcp_pcb again. */
root@mbed.org	0:5e1631496985	1012	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
root@mbed.org	0:5e1631496985	1013	}
root@mbed.org	0:5e1631496985	1014	}
root@mbed.org	0:5e1631496985	1015	if (pcb != NULL) {
root@mbed.org	0:5e1631496985	1016	memset(pcb, 0, sizeof(struct tcp_pcb));
root@mbed.org	0:5e1631496985	1017	pcb->prio = TCP_PRIO_NORMAL;
root@mbed.org	0:5e1631496985	1018	pcb->snd_buf = TCP_SND_BUF;
root@mbed.org	0:5e1631496985	1019	pcb->snd_queuelen = 0;
root@mbed.org	0:5e1631496985	1020	pcb->rcv_wnd = TCP_WND;
root@mbed.org	0:5e1631496985	1021	pcb->rcv_ann_wnd = TCP_WND;
root@mbed.org	0:5e1631496985	1022	pcb->tos = 0;
root@mbed.org	0:5e1631496985	1023	pcb->ttl = TCP_TTL;
root@mbed.org	0:5e1631496985	1024	/* As initial send MSS, we use TCP_MSS but limit it to 536.
root@mbed.org	0:5e1631496985	1025	The send MSS is updated when an MSS option is received. */
root@mbed.org	0:5e1631496985	1026	pcb->mss = (TCP_MSS > 536) ? 536 : TCP_MSS;
root@mbed.org	0:5e1631496985	1027	pcb->rto = 3000 / TCP_SLOW_INTERVAL;
root@mbed.org	0:5e1631496985	1028	pcb->sa = 0;
root@mbed.org	0:5e1631496985	1029	pcb->sv = 3000 / TCP_SLOW_INTERVAL;
root@mbed.org	0:5e1631496985	1030	pcb->rtime = -1;
root@mbed.org	0:5e1631496985	1031	pcb->cwnd = 1;
root@mbed.org	0:5e1631496985	1032	iss = tcp_next_iss();
root@mbed.org	0:5e1631496985	1033	pcb->snd_wl2 = iss;
root@mbed.org	0:5e1631496985	1034	pcb->snd_nxt = iss;
root@mbed.org	0:5e1631496985	1035	pcb->lastack = iss;
root@mbed.org	0:5e1631496985	1036	pcb->snd_lbb = iss;
root@mbed.org	0:5e1631496985	1037	pcb->tmr = tcp_ticks;
root@mbed.org	0:5e1631496985	1038
root@mbed.org	0:5e1631496985	1039	pcb->polltmr = 0;
root@mbed.org	0:5e1631496985	1040
root@mbed.org	0:5e1631496985	1041	#if LWIP_CALLBACK_API
root@mbed.org	0:5e1631496985	1042	pcb->recv = tcp_recv_null;
root@mbed.org	0:5e1631496985	1043	#endif /* LWIP_CALLBACK_API */
root@mbed.org	0:5e1631496985	1044
root@mbed.org	0:5e1631496985	1045	/* Init KEEPALIVE timer */
root@mbed.org	0:5e1631496985	1046	pcb->keep_idle = TCP_KEEPIDLE_DEFAULT;
root@mbed.org	0:5e1631496985	1047
root@mbed.org	0:5e1631496985	1048	#if LWIP_TCP_KEEPALIVE
root@mbed.org	0:5e1631496985	1049	pcb->keep_intvl = TCP_KEEPINTVL_DEFAULT;
root@mbed.org	0:5e1631496985	1050	pcb->keep_cnt = TCP_KEEPCNT_DEFAULT;
root@mbed.org	0:5e1631496985	1051	#endif /* LWIP_TCP_KEEPALIVE */
root@mbed.org	0:5e1631496985	1052
root@mbed.org	0:5e1631496985	1053	pcb->keep_cnt_sent = 0;
root@mbed.org	0:5e1631496985	1054	}
root@mbed.org	0:5e1631496985	1055	return pcb;
root@mbed.org	0:5e1631496985	1056	}
root@mbed.org	0:5e1631496985	1057
root@mbed.org	0:5e1631496985	1058	/**
root@mbed.org	0:5e1631496985	1059	* Creates a new TCP protocol control block but doesn't place it on
root@mbed.org	0:5e1631496985	1060	* any of the TCP PCB lists.
root@mbed.org	0:5e1631496985	1061	* The pcb is not put on any list until binding using tcp_bind().
root@mbed.org	0:5e1631496985	1062	*
root@mbed.org	0:5e1631496985	1063	* @internal: Maybe there should be a idle TCP PCB list where these
root@mbed.org	0:5e1631496985	1064	* PCBs are put on. Port reservation using tcp_bind() is implemented but
root@mbed.org	0:5e1631496985	1065	* allocated pcbs that are not bound can't be killed automatically if wanting
root@mbed.org	0:5e1631496985	1066	* to allocate a pcb with higher prio (@see tcp_kill_prio())
root@mbed.org	0:5e1631496985	1067	*
root@mbed.org	0:5e1631496985	1068	* @return a new tcp_pcb that initially is in state CLOSED
root@mbed.org	0:5e1631496985	1069	*/
root@mbed.org	0:5e1631496985	1070	struct tcp_pcb *
root@mbed.org	0:5e1631496985	1071	tcp_new(void)
root@mbed.org	0:5e1631496985	1072	{
root@mbed.org	0:5e1631496985	1073	return tcp_alloc(TCP_PRIO_NORMAL);
root@mbed.org	0:5e1631496985	1074	}
root@mbed.org	0:5e1631496985	1075
root@mbed.org	0:5e1631496985	1076	/**
root@mbed.org	0:5e1631496985	1077	* Used to specify the argument that should be passed callback
root@mbed.org	0:5e1631496985	1078	* functions.
root@mbed.org	0:5e1631496985	1079	*
root@mbed.org	0:5e1631496985	1080	* @param pcb tcp_pcb to set the callback argument
root@mbed.org	0:5e1631496985	1081	* @param arg void pointer argument to pass to callback functions
root@mbed.org	0:5e1631496985	1082	*/
root@mbed.org	0:5e1631496985	1083	void
root@mbed.org	0:5e1631496985	1084	tcp_arg(struct tcp_pcb pcb, void arg)
root@mbed.org	0:5e1631496985	1085	{
root@mbed.org	0:5e1631496985	1086	pcb->callback_arg = arg;
root@mbed.org	0:5e1631496985	1087	}
root@mbed.org	0:5e1631496985	1088	#if LWIP_CALLBACK_API
root@mbed.org	0:5e1631496985	1089
root@mbed.org	0:5e1631496985	1090	/**
root@mbed.org	0:5e1631496985	1091	* Used to specify the function that should be called when a TCP
root@mbed.org	0:5e1631496985	1092	* connection receives data.
root@mbed.org	0:5e1631496985	1093	*
root@mbed.org	0:5e1631496985	1094	* @param pcb tcp_pcb to set the recv callback
root@mbed.org	0:5e1631496985	1095	* @param recv callback function to call for this pcb when data is received
root@mbed.org	0:5e1631496985	1096	*/
root@mbed.org	0:5e1631496985	1097	void
root@mbed.org	0:5e1631496985	1098	tcp_recv(struct tcp_pcb *pcb,
root@mbed.org	0:5e1631496985	1099	err_t (* recv)(void arg, struct tcp_pcb tpcb, struct pbuf *p, err_t err))
root@mbed.org	0:5e1631496985	1100	{
root@mbed.org	0:5e1631496985	1101	pcb->recv = recv;
root@mbed.org	0:5e1631496985	1102	}
root@mbed.org	0:5e1631496985	1103
root@mbed.org	0:5e1631496985	1104	/**
root@mbed.org	0:5e1631496985	1105	* Used to specify the function that should be called when TCP data
root@mbed.org	0:5e1631496985	1106	* has been successfully delivered to the remote host.
root@mbed.org	0:5e1631496985	1107	*
root@mbed.org	0:5e1631496985	1108	* @param pcb tcp_pcb to set the sent callback
root@mbed.org	0:5e1631496985	1109	* @param sent callback function to call for this pcb when data is successfully sent
root@mbed.org	0:5e1631496985	1110	*/
root@mbed.org	0:5e1631496985	1111	void
root@mbed.org	0:5e1631496985	1112	tcp_sent(struct tcp_pcb *pcb,
root@mbed.org	0:5e1631496985	1113	err_t (* sent)(void arg, struct tcp_pcb tpcb, u16_t len))
root@mbed.org	0:5e1631496985	1114	{
root@mbed.org	0:5e1631496985	1115	pcb->sent = sent;
root@mbed.org	0:5e1631496985	1116	}
root@mbed.org	0:5e1631496985	1117
root@mbed.org	0:5e1631496985	1118	/**
root@mbed.org	0:5e1631496985	1119	* Used to specify the function that should be called when a fatal error
root@mbed.org	0:5e1631496985	1120	* has occured on the connection.
root@mbed.org	0:5e1631496985	1121	*
root@mbed.org	0:5e1631496985	1122	* @param pcb tcp_pcb to set the err callback
root@mbed.org	0:5e1631496985	1123	* @param errf callback function to call for this pcb when a fatal error
root@mbed.org	0:5e1631496985	1124	* has occured on the connection
root@mbed.org	0:5e1631496985	1125	*/
root@mbed.org	0:5e1631496985	1126	void
root@mbed.org	0:5e1631496985	1127	tcp_err(struct tcp_pcb *pcb,
root@mbed.org	0:5e1631496985	1128	void (* errf)(void *arg, err_t err))
root@mbed.org	0:5e1631496985	1129	{
root@mbed.org	0:5e1631496985	1130	pcb->errf = errf;
root@mbed.org	0:5e1631496985	1131	}
root@mbed.org	0:5e1631496985	1132
root@mbed.org	0:5e1631496985	1133	/**
root@mbed.org	0:5e1631496985	1134	* Used for specifying the function that should be called when a
root@mbed.org	0:5e1631496985	1135	* LISTENing connection has been connected to another host.
root@mbed.org	0:5e1631496985	1136	*
root@mbed.org	0:5e1631496985	1137	* @param pcb tcp_pcb to set the accept callback
root@mbed.org	0:5e1631496985	1138	* @param accept callback function to call for this pcb when LISTENing
root@mbed.org	0:5e1631496985	1139	* connection has been connected to another host
root@mbed.org	0:5e1631496985	1140	*/
root@mbed.org	0:5e1631496985	1141	void
root@mbed.org	0:5e1631496985	1142	tcp_accept(struct tcp_pcb *pcb,
root@mbed.org	0:5e1631496985	1143	err_t (* accept)(void arg, struct tcp_pcb newpcb, err_t err))
root@mbed.org	0:5e1631496985	1144	{
root@mbed.org	0:5e1631496985	1145	pcb->accept = accept;
root@mbed.org	0:5e1631496985	1146	}
root@mbed.org	0:5e1631496985	1147	#endif /* LWIP_CALLBACK_API */
root@mbed.org	0:5e1631496985	1148
root@mbed.org	0:5e1631496985	1149
root@mbed.org	0:5e1631496985	1150	/**
root@mbed.org	0:5e1631496985	1151	* Used to specify the function that should be called periodically
root@mbed.org	0:5e1631496985	1152	* from TCP. The interval is specified in terms of the TCP coarse
root@mbed.org	0:5e1631496985	1153	* timer interval, which is called twice a second.
root@mbed.org	0:5e1631496985	1154	*
root@mbed.org	0:5e1631496985	1155	*/
root@mbed.org	0:5e1631496985	1156	void
root@mbed.org	0:5e1631496985	1157	tcp_poll(struct tcp_pcb *pcb,
root@mbed.org	0:5e1631496985	1158	err_t (* poll)(void arg, struct tcp_pcb tpcb), u8_t interval)
root@mbed.org	0:5e1631496985	1159	{
root@mbed.org	0:5e1631496985	1160	#if LWIP_CALLBACK_API
root@mbed.org	0:5e1631496985	1161	pcb->poll = poll;
root@mbed.org	0:5e1631496985	1162	#endif /* LWIP_CALLBACK_API */
root@mbed.org	0:5e1631496985	1163	pcb->pollinterval = interval;
root@mbed.org	0:5e1631496985	1164	}
root@mbed.org	0:5e1631496985	1165
root@mbed.org	0:5e1631496985	1166	/**
root@mbed.org	0:5e1631496985	1167	* Purges a TCP PCB. Removes any buffered data and frees the buffer memory
root@mbed.org	0:5e1631496985	1168	* (pcb->ooseq, pcb->unsent and pcb->unacked are freed).
root@mbed.org	0:5e1631496985	1169	*
root@mbed.org	0:5e1631496985	1170	* @param pcb tcp_pcb to purge. The pcb itself is not deallocated!
root@mbed.org	0:5e1631496985	1171	*/
root@mbed.org	0:5e1631496985	1172	void
root@mbed.org	0:5e1631496985	1173	tcp_pcb_purge(struct tcp_pcb *pcb)
root@mbed.org	0:5e1631496985	1174	{
root@mbed.org	0:5e1631496985	1175	if (pcb->state != CLOSED &&
root@mbed.org	0:5e1631496985	1176	pcb->state != TIME_WAIT &&
root@mbed.org	0:5e1631496985	1177	pcb->state != LISTEN) {
root@mbed.org	0:5e1631496985	1178
root@mbed.org	0:5e1631496985	1179	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge\n"));
root@mbed.org	0:5e1631496985	1180
root@mbed.org	0:5e1631496985	1181	#if TCP_LISTEN_BACKLOG
root@mbed.org	0:5e1631496985	1182	if (pcb->state == SYN_RCVD) {
root@mbed.org	0:5e1631496985	1183	/* Need to find the corresponding listen_pcb and decrease its accepts_pending */
root@mbed.org	0:5e1631496985	1184	struct tcp_pcb_listen *lpcb;
root@mbed.org	0:5e1631496985	1185	LWIP_ASSERT("tcp_pcb_purge: pcb->state == SYN_RCVD but tcp_listen_pcbs is NULL",
root@mbed.org	0:5e1631496985	1186	tcp_listen_pcbs.listen_pcbs != NULL);
root@mbed.org	0:5e1631496985	1187	for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
root@mbed.org	0:5e1631496985	1188	if ((lpcb->local_port == pcb->local_port) &&
root@mbed.org	0:5e1631496985	1189	(ip_addr_isany(&lpcb->local_ip) \|\|
root@mbed.org	0:5e1631496985	1190	ip_addr_cmp(&pcb->local_ip, &lpcb->local_ip))) {
root@mbed.org	0:5e1631496985	1191	/* port and address of the listen pcb match the timed-out pcb */
root@mbed.org	0:5e1631496985	1192	LWIP_ASSERT("tcp_pcb_purge: listen pcb does not have accepts pending",
root@mbed.org	0:5e1631496985	1193	lpcb->accepts_pending > 0);
root@mbed.org	0:5e1631496985	1194	lpcb->accepts_pending--;
root@mbed.org	0:5e1631496985	1195	break;
root@mbed.org	0:5e1631496985	1196	}
root@mbed.org	0:5e1631496985	1197	}
root@mbed.org	0:5e1631496985	1198	}
root@mbed.org	0:5e1631496985	1199	#endif /* TCP_LISTEN_BACKLOG */
root@mbed.org	0:5e1631496985	1200
root@mbed.org	0:5e1631496985	1201
root@mbed.org	0:5e1631496985	1202	if (pcb->refused_data != NULL) {
root@mbed.org	0:5e1631496985	1203	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->refused_data\n"));
root@mbed.org	0:5e1631496985	1204	pbuf_free(pcb->refused_data);
root@mbed.org	0:5e1631496985	1205	pcb->refused_data = NULL;
root@mbed.org	0:5e1631496985	1206	}
root@mbed.org	0:5e1631496985	1207	if (pcb->unsent != NULL) {
root@mbed.org	0:5e1631496985	1208	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: not all data sent\n"));
root@mbed.org	0:5e1631496985	1209	}
root@mbed.org	0:5e1631496985	1210	if (pcb->unacked != NULL) {
root@mbed.org	0:5e1631496985	1211	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->unacked\n"));
root@mbed.org	0:5e1631496985	1212	}
root@mbed.org	0:5e1631496985	1213	#if TCP_QUEUE_OOSEQ /* LW */
root@mbed.org	0:5e1631496985	1214	if (pcb->ooseq != NULL) {
root@mbed.org	0:5e1631496985	1215	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->ooseq\n"));
root@mbed.org	0:5e1631496985	1216	}
root@mbed.org	0:5e1631496985	1217
root@mbed.org	0:5e1631496985	1218	/* Stop the retransmission timer as it will expect data on unacked
root@mbed.org	0:5e1631496985	1219	queue if it fires */
root@mbed.org	0:5e1631496985	1220	pcb->rtime = -1;
root@mbed.org	0:5e1631496985	1221
root@mbed.org	0:5e1631496985	1222	tcp_segs_free(pcb->ooseq);
root@mbed.org	0:5e1631496985	1223	pcb->ooseq = NULL;
root@mbed.org	0:5e1631496985	1224	#endif /* TCP_QUEUE_OOSEQ */
root@mbed.org	0:5e1631496985	1225	tcp_segs_free(pcb->unsent);
root@mbed.org	0:5e1631496985	1226	tcp_segs_free(pcb->unacked);
root@mbed.org	0:5e1631496985	1227	pcb->unacked = pcb->unsent = NULL;
root@mbed.org	0:5e1631496985	1228	}
root@mbed.org	0:5e1631496985	1229	}
root@mbed.org	0:5e1631496985	1230
root@mbed.org	0:5e1631496985	1231	/**
root@mbed.org	0:5e1631496985	1232	* Purges the PCB and removes it from a PCB list. Any delayed ACKs are sent first.
root@mbed.org	0:5e1631496985	1233	*
root@mbed.org	0:5e1631496985	1234	* @param pcblist PCB list to purge.
root@mbed.org	0:5e1631496985	1235	* @param pcb tcp_pcb to purge. The pcb itself is also deallocated!
root@mbed.org	0:5e1631496985	1236	*/
root@mbed.org	0:5e1631496985	1237	void
root@mbed.org	0:5e1631496985	1238	tcp_pcb_remove(struct tcp_pcb *pcblist, struct tcp_pcb pcb)
root@mbed.org	0:5e1631496985	1239	{
root@mbed.org	0:5e1631496985	1240	TCP_RMV(pcblist, pcb);
root@mbed.org	0:5e1631496985	1241
root@mbed.org	0:5e1631496985	1242	tcp_pcb_purge(pcb);
root@mbed.org	0:5e1631496985	1243
root@mbed.org	0:5e1631496985	1244	/* if there is an outstanding delayed ACKs, send it */
root@mbed.org	0:5e1631496985	1245	if (pcb->state != TIME_WAIT &&
root@mbed.org	0:5e1631496985	1246	pcb->state != LISTEN &&
root@mbed.org	0:5e1631496985	1247	pcb->flags & TF_ACK_DELAY) {
root@mbed.org	0:5e1631496985	1248	pcb->flags \|= TF_ACK_NOW;
root@mbed.org	0:5e1631496985	1249	tcp_output(pcb);
root@mbed.org	0:5e1631496985	1250	}
root@mbed.org	0:5e1631496985	1251
root@mbed.org	0:5e1631496985	1252	if (pcb->state != LISTEN) {
root@mbed.org	0:5e1631496985	1253	LWIP_ASSERT("unsent segments leaking", pcb->unsent == NULL);
root@mbed.org	0:5e1631496985	1254	LWIP_ASSERT("unacked segments leaking", pcb->unacked == NULL);
root@mbed.org	0:5e1631496985	1255	#if TCP_QUEUE_OOSEQ
root@mbed.org	0:5e1631496985	1256	LWIP_ASSERT("ooseq segments leaking", pcb->ooseq == NULL);
root@mbed.org	0:5e1631496985	1257	#endif /* TCP_QUEUE_OOSEQ */
root@mbed.org	0:5e1631496985	1258	}
root@mbed.org	0:5e1631496985	1259
root@mbed.org	0:5e1631496985	1260	pcb->state = CLOSED;
root@mbed.org	0:5e1631496985	1261
root@mbed.org	0:5e1631496985	1262	LWIP_ASSERT("tcp_pcb_remove: tcp_pcbs_sane()", tcp_pcbs_sane());
root@mbed.org	0:5e1631496985	1263	}
root@mbed.org	0:5e1631496985	1264
root@mbed.org	0:5e1631496985	1265	/**
root@mbed.org	0:5e1631496985	1266	* Calculates a new initial sequence number for new connections.
root@mbed.org	0:5e1631496985	1267	*
root@mbed.org	0:5e1631496985	1268	* @return u32_t pseudo random sequence number
root@mbed.org	0:5e1631496985	1269	*/
root@mbed.org	0:5e1631496985	1270	u32_t
root@mbed.org	0:5e1631496985	1271	tcp_next_iss(void)
root@mbed.org	0:5e1631496985	1272	{
root@mbed.org	0:5e1631496985	1273	static u32_t iss = 6510;
root@mbed.org	0:5e1631496985	1274
root@mbed.org	0:5e1631496985	1275	iss += tcp_ticks; /* XXX */
root@mbed.org	0:5e1631496985	1276	return iss;
root@mbed.org	0:5e1631496985	1277	}
root@mbed.org	0:5e1631496985	1278
root@mbed.org	0:5e1631496985	1279	#if TCP_CALCULATE_EFF_SEND_MSS
root@mbed.org	0:5e1631496985	1280	/**
root@mbed.org	0:5e1631496985	1281	* Calcluates the effective send mss that can be used for a specific IP address
root@mbed.org	0:5e1631496985	1282	* by using ip_route to determin the netif used to send to the address and
root@mbed.org	0:5e1631496985	1283	* calculating the minimum of TCP_MSS and that netif's mtu (if set).
root@mbed.org	0:5e1631496985	1284	*/
root@mbed.org	0:5e1631496985	1285	u16_t
root@mbed.org	0:5e1631496985	1286	tcp_eff_send_mss(u16_t sendmss, struct ip_addr *addr)
root@mbed.org	0:5e1631496985	1287	{
root@mbed.org	0:5e1631496985	1288	u16_t mss_s;
root@mbed.org	0:5e1631496985	1289	struct netif *outif;
root@mbed.org	0:5e1631496985	1290
root@mbed.org	0:5e1631496985	1291	outif = ip_route(addr);
root@mbed.org	0:5e1631496985	1292	if ((outif != NULL) && (outif->mtu != 0)) {
root@mbed.org	0:5e1631496985	1293	mss_s = outif->mtu - IP_HLEN - TCP_HLEN;
root@mbed.org	0:5e1631496985	1294	/* RFC 1122, chap 4.2.2.6:
root@mbed.org	0:5e1631496985	1295	* Eff.snd.MSS = min(SendMSS+20, MMS_S) - TCPhdrsize - IPoptionsize
root@mbed.org	0:5e1631496985	1296	* We correct for TCP options in tcp_enqueue(), and don't support
root@mbed.org	0:5e1631496985	1297	* IP options
root@mbed.org	0:5e1631496985	1298	*/
root@mbed.org	0:5e1631496985	1299	sendmss = LWIP_MIN(sendmss, mss_s);
root@mbed.org	0:5e1631496985	1300	}
root@mbed.org	0:5e1631496985	1301	return sendmss;
root@mbed.org	0:5e1631496985	1302	}
root@mbed.org	0:5e1631496985	1303	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
root@mbed.org	0:5e1631496985	1304
root@mbed.org	0:5e1631496985	1305	const char*
root@mbed.org	0:5e1631496985	1306	tcp_debug_state_str(enum tcp_state s)
root@mbed.org	0:5e1631496985	1307	{
root@mbed.org	0:5e1631496985	1308	return tcp_state_str[s];
root@mbed.org	0:5e1631496985	1309	}
root@mbed.org	0:5e1631496985	1310
root@mbed.org	0:5e1631496985	1311	#if TCP_DEBUG \|\| TCP_INPUT_DEBUG \|\| TCP_OUTPUT_DEBUG
root@mbed.org	0:5e1631496985	1312	/**
root@mbed.org	0:5e1631496985	1313	* Print a tcp header for debugging purposes.
root@mbed.org	0:5e1631496985	1314	*
root@mbed.org	0:5e1631496985	1315	* @param tcphdr pointer to a struct tcp_hdr
root@mbed.org	0:5e1631496985	1316	*/
root@mbed.org	0:5e1631496985	1317	void
root@mbed.org	0:5e1631496985	1318	tcp_debug_print(struct tcp_hdr *tcphdr)
root@mbed.org	0:5e1631496985	1319	{
root@mbed.org	0:5e1631496985	1320	LWIP_DEBUGF(TCP_DEBUG, ("TCP header:\n"));
root@mbed.org	0:5e1631496985	1321	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
root@mbed.org	0:5e1631496985	1322	LWIP_DEBUGF(TCP_DEBUG, ("\| %5"U16_F" \| %5"U16_F" \| (src port, dest port)\n",
root@mbed.org	0:5e1631496985	1323	ntohs(tcphdr->src), ntohs(tcphdr->dest)));
root@mbed.org	0:5e1631496985	1324	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
root@mbed.org	0:5e1631496985	1325	LWIP_DEBUGF(TCP_DEBUG, ("\| %010"U32_F" \| (seq no)\n",
root@mbed.org	0:5e1631496985	1326	ntohl(tcphdr->seqno)));
root@mbed.org	0:5e1631496985	1327	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
root@mbed.org	0:5e1631496985	1328	LWIP_DEBUGF(TCP_DEBUG, ("\| %010"U32_F" \| (ack no)\n",
root@mbed.org	0:5e1631496985	1329	ntohl(tcphdr->ackno)));
root@mbed.org	0:5e1631496985	1330	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
root@mbed.org	0:5e1631496985	1331	LWIP_DEBUGF(TCP_DEBUG, ("\| %2"U16_F" \| \|%"U16_F"%"U16_F"%"U16_F"%"U16_F"%"U16_F"%"U16_F"\| %5"U16_F" \| (hdrlen, flags (",
root@mbed.org	0:5e1631496985	1332	TCPH_HDRLEN(tcphdr),
root@mbed.org	0:5e1631496985	1333	TCPH_FLAGS(tcphdr) >> 5 & 1,
root@mbed.org	0:5e1631496985	1334	TCPH_FLAGS(tcphdr) >> 4 & 1,
root@mbed.org	0:5e1631496985	1335	TCPH_FLAGS(tcphdr) >> 3 & 1,
root@mbed.org	0:5e1631496985	1336	TCPH_FLAGS(tcphdr) >> 2 & 1,
root@mbed.org	0:5e1631496985	1337	TCPH_FLAGS(tcphdr) >> 1 & 1,
root@mbed.org	0:5e1631496985	1338	TCPH_FLAGS(tcphdr) & 1,
root@mbed.org	0:5e1631496985	1339	ntohs(tcphdr->wnd)));
root@mbed.org	0:5e1631496985	1340	tcp_debug_print_flags(TCPH_FLAGS(tcphdr));
root@mbed.org	0:5e1631496985	1341	LWIP_DEBUGF(TCP_DEBUG, ("), win)\n"));
root@mbed.org	0:5e1631496985	1342	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
root@mbed.org	0:5e1631496985	1343	LWIP_DEBUGF(TCP_DEBUG, ("\| 0x%04"X16_F" \| %5"U16_F" \| (chksum, urgp)\n",
root@mbed.org	0:5e1631496985	1344	ntohs(tcphdr->chksum), ntohs(tcphdr->urgp)));
root@mbed.org	0:5e1631496985	1345	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
root@mbed.org	0:5e1631496985	1346	}
root@mbed.org	0:5e1631496985	1347
root@mbed.org	0:5e1631496985	1348	/**
root@mbed.org	0:5e1631496985	1349	* Print a tcp state for debugging purposes.
root@mbed.org	0:5e1631496985	1350	*
root@mbed.org	0:5e1631496985	1351	* @param s enum tcp_state to print
root@mbed.org	0:5e1631496985	1352	*/
root@mbed.org	0:5e1631496985	1353	void
root@mbed.org	0:5e1631496985	1354	tcp_debug_print_state(enum tcp_state s)
root@mbed.org	0:5e1631496985	1355	{
root@mbed.org	0:5e1631496985	1356	LWIP_DEBUGF(TCP_DEBUG, ("State: %s\n", tcp_state_str[s]));
root@mbed.org	0:5e1631496985	1357	}
root@mbed.org	0:5e1631496985	1358
root@mbed.org	0:5e1631496985	1359	/**
root@mbed.org	0:5e1631496985	1360	* Print tcp flags for debugging purposes.
root@mbed.org	0:5e1631496985	1361	*
root@mbed.org	0:5e1631496985	1362	* @param flags tcp flags, all active flags are printed
root@mbed.org	0:5e1631496985	1363	*/
root@mbed.org	0:5e1631496985	1364	void
root@mbed.org	0:5e1631496985	1365	tcp_debug_print_flags(u8_t flags)
root@mbed.org	0:5e1631496985	1366	{
root@mbed.org	0:5e1631496985	1367	if (flags & TCP_FIN) {
root@mbed.org	0:5e1631496985	1368	LWIP_DEBUGF(TCP_DEBUG, ("FIN "));
root@mbed.org	0:5e1631496985	1369	}
root@mbed.org	0:5e1631496985	1370	if (flags & TCP_SYN) {
root@mbed.org	0:5e1631496985	1371	LWIP_DEBUGF(TCP_DEBUG, ("SYN "));
root@mbed.org	0:5e1631496985	1372	}
root@mbed.org	0:5e1631496985	1373	if (flags & TCP_RST) {
root@mbed.org	0:5e1631496985	1374	LWIP_DEBUGF(TCP_DEBUG, ("RST "));
root@mbed.org	0:5e1631496985	1375	}
root@mbed.org	0:5e1631496985	1376	if (flags & TCP_PSH) {
root@mbed.org	0:5e1631496985	1377	LWIP_DEBUGF(TCP_DEBUG, ("PSH "));
root@mbed.org	0:5e1631496985	1378	}
root@mbed.org	0:5e1631496985	1379	if (flags & TCP_ACK) {
root@mbed.org	0:5e1631496985	1380	LWIP_DEBUGF(TCP_DEBUG, ("ACK "));
root@mbed.org	0:5e1631496985	1381	}
root@mbed.org	0:5e1631496985	1382	if (flags & TCP_URG) {
root@mbed.org	0:5e1631496985	1383	LWIP_DEBUGF(TCP_DEBUG, ("URG "));
root@mbed.org	0:5e1631496985	1384	}
root@mbed.org	0:5e1631496985	1385	if (flags & TCP_ECE) {
root@mbed.org	0:5e1631496985	1386	LWIP_DEBUGF(TCP_DEBUG, ("ECE "));
root@mbed.org	0:5e1631496985	1387	}
root@mbed.org	0:5e1631496985	1388	if (flags & TCP_CWR) {
root@mbed.org	0:5e1631496985	1389	LWIP_DEBUGF(TCP_DEBUG, ("CWR "));
root@mbed.org	0:5e1631496985	1390	}
root@mbed.org	0:5e1631496985	1391	LWIP_DEBUGF(TCP_DEBUG, ("\n"));
root@mbed.org	0:5e1631496985	1392	}
root@mbed.org	0:5e1631496985	1393
root@mbed.org	0:5e1631496985	1394	/**
root@mbed.org	0:5e1631496985	1395	* Print all tcp_pcbs in every list for debugging purposes.
root@mbed.org	0:5e1631496985	1396	*/
root@mbed.org	0:5e1631496985	1397	void
root@mbed.org	0:5e1631496985	1398	tcp_debug_print_pcbs(void)
root@mbed.org	0:5e1631496985	1399	{
root@mbed.org	0:5e1631496985	1400	struct tcp_pcb *pcb;
root@mbed.org	0:5e1631496985	1401	LWIP_DEBUGF(TCP_DEBUG, ("Active PCB states:\n"));
root@mbed.org	0:5e1631496985	1402	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
root@mbed.org	0:5e1631496985	1403	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
root@mbed.org	0:5e1631496985	1404	pcb->local_port, pcb->remote_port,
root@mbed.org	0:5e1631496985	1405	pcb->snd_nxt, pcb->rcv_nxt));
root@mbed.org	0:5e1631496985	1406	tcp_debug_print_state(pcb->state);
root@mbed.org	0:5e1631496985	1407	}
root@mbed.org	0:5e1631496985	1408	LWIP_DEBUGF(TCP_DEBUG, ("Listen PCB states:\n"));
root@mbed.org	0:5e1631496985	1409	for(pcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs; pcb != NULL; pcb = pcb->next) {
root@mbed.org	0:5e1631496985	1410	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
root@mbed.org	0:5e1631496985	1411	pcb->local_port, pcb->remote_port,
root@mbed.org	0:5e1631496985	1412	pcb->snd_nxt, pcb->rcv_nxt));
root@mbed.org	0:5e1631496985	1413	tcp_debug_print_state(pcb->state);
root@mbed.org	0:5e1631496985	1414	}
root@mbed.org	0:5e1631496985	1415	LWIP_DEBUGF(TCP_DEBUG, ("TIME-WAIT PCB states:\n"));
root@mbed.org	0:5e1631496985	1416	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
root@mbed.org	0:5e1631496985	1417	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
root@mbed.org	0:5e1631496985	1418	pcb->local_port, pcb->remote_port,
root@mbed.org	0:5e1631496985	1419	pcb->snd_nxt, pcb->rcv_nxt));
root@mbed.org	0:5e1631496985	1420	tcp_debug_print_state(pcb->state);
root@mbed.org	0:5e1631496985	1421	}
root@mbed.org	0:5e1631496985	1422	}
root@mbed.org	0:5e1631496985	1423
root@mbed.org	0:5e1631496985	1424	/**
root@mbed.org	0:5e1631496985	1425	* Check state consistency of the tcp_pcb lists.
root@mbed.org	0:5e1631496985	1426	*/
root@mbed.org	0:5e1631496985	1427	s16_t
root@mbed.org	0:5e1631496985	1428	tcp_pcbs_sane(void)
root@mbed.org	0:5e1631496985	1429	{
root@mbed.org	0:5e1631496985	1430	struct tcp_pcb *pcb;
root@mbed.org	0:5e1631496985	1431	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
root@mbed.org	0:5e1631496985	1432	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != CLOSED", pcb->state != CLOSED);
root@mbed.org	0:5e1631496985	1433	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != LISTEN", pcb->state != LISTEN);
root@mbed.org	0:5e1631496985	1434	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT);
root@mbed.org	0:5e1631496985	1435	}
root@mbed.org	0:5e1631496985	1436	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
root@mbed.org	0:5e1631496985	1437	LWIP_ASSERT("tcp_pcbs_sane: tw pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
root@mbed.org	0:5e1631496985	1438	}
root@mbed.org	0:5e1631496985	1439	return 1;
root@mbed.org	0:5e1631496985	1440	}
root@mbed.org	0:5e1631496985	1441	#endif /* TCP_DEBUG */
root@mbed.org	0:5e1631496985	1442
root@mbed.org	0:5e1631496985	1443	#endif /* LWIP_TCP */