WebSockets2 - Embedded WebSockets Experiment

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Embedded WebSockets Experiment

Core/lwIP/core/tcp.c@0:6dee052a3fa4, 2011-07-26 (annotated)

Committer:: nandgate
Date:: Tue Jul 26 05:30:53 2011 +0000
Revision:: 0:6dee052a3fa4

Who changed what in which revision?

User	Revision	Line number	New contents of line
nandgate	0:6dee052a3fa4	1	/**
nandgate	0:6dee052a3fa4	2	* @file
nandgate	0:6dee052a3fa4	3	* Transmission Control Protocol for IP
nandgate	0:6dee052a3fa4	4	*
nandgate	0:6dee052a3fa4	5	* This file contains common functions for the TCP implementation, such as functinos
nandgate	0:6dee052a3fa4	6	* for manipulating the data structures and the TCP timer functions. TCP functions
nandgate	0:6dee052a3fa4	7	* related to input and output is found in tcp_in.c and tcp_out.c respectively.
nandgate	0:6dee052a3fa4	8	*
nandgate	0:6dee052a3fa4	9	*/
nandgate	0:6dee052a3fa4	10
nandgate	0:6dee052a3fa4	11	/*
nandgate	0:6dee052a3fa4	12	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
nandgate	0:6dee052a3fa4	13	* All rights reserved.
nandgate	0:6dee052a3fa4	14	*
nandgate	0:6dee052a3fa4	15	* Redistribution and use in source and binary forms, with or without modification,
nandgate	0:6dee052a3fa4	16	* are permitted provided that the following conditions are met:
nandgate	0:6dee052a3fa4	17	*
nandgate	0:6dee052a3fa4	18	* 1. Redistributions of source code must retain the above copyright notice,
nandgate	0:6dee052a3fa4	19	* this list of conditions and the following disclaimer.
nandgate	0:6dee052a3fa4	20	* 2. Redistributions in binary form must reproduce the above copyright notice,
nandgate	0:6dee052a3fa4	21	* this list of conditions and the following disclaimer in the documentation
nandgate	0:6dee052a3fa4	22	* and/or other materials provided with the distribution.
nandgate	0:6dee052a3fa4	23	* 3. The name of the author may not be used to endorse or promote products
nandgate	0:6dee052a3fa4	24	* derived from this software without specific prior written permission.
nandgate	0:6dee052a3fa4	25	*
nandgate	0:6dee052a3fa4	26	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
nandgate	0:6dee052a3fa4	27	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
nandgate	0:6dee052a3fa4	28	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
nandgate	0:6dee052a3fa4	29	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
nandgate	0:6dee052a3fa4	30	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
nandgate	0:6dee052a3fa4	31	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
nandgate	0:6dee052a3fa4	32	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
nandgate	0:6dee052a3fa4	33	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
nandgate	0:6dee052a3fa4	34	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
nandgate	0:6dee052a3fa4	35	* OF SUCH DAMAGE.
nandgate	0:6dee052a3fa4	36	*
nandgate	0:6dee052a3fa4	37	* This file is part of the lwIP TCP/IP stack.
nandgate	0:6dee052a3fa4	38	*
nandgate	0:6dee052a3fa4	39	* Author: Adam Dunkels <adam@sics.se>
nandgate	0:6dee052a3fa4	40	*
nandgate	0:6dee052a3fa4	41	*/
nandgate	0:6dee052a3fa4	42
nandgate	0:6dee052a3fa4	43	#include "lwip/opt.h"
nandgate	0:6dee052a3fa4	44
nandgate	0:6dee052a3fa4	45	#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
nandgate	0:6dee052a3fa4	46
nandgate	0:6dee052a3fa4	47	#include "lwip/def.h"
nandgate	0:6dee052a3fa4	48	#include "lwip/mem.h"
nandgate	0:6dee052a3fa4	49	#include "lwip/memp.h"
nandgate	0:6dee052a3fa4	50	#include "lwip/snmp.h"
nandgate	0:6dee052a3fa4	51	#include "lwip/tcp.h"
nandgate	0:6dee052a3fa4	52	#include "lwip/debug.h"
nandgate	0:6dee052a3fa4	53
nandgate	0:6dee052a3fa4	54	#include <string.h>
nandgate	0:6dee052a3fa4	55
nandgate	0:6dee052a3fa4	56	const char *tcp_state_str[] = {
nandgate	0:6dee052a3fa4	57	"CLOSED",
nandgate	0:6dee052a3fa4	58	"LISTEN",
nandgate	0:6dee052a3fa4	59	"SYN_SENT",
nandgate	0:6dee052a3fa4	60	"SYN_RCVD",
nandgate	0:6dee052a3fa4	61	"ESTABLISHED",
nandgate	0:6dee052a3fa4	62	"FIN_WAIT_1",
nandgate	0:6dee052a3fa4	63	"FIN_WAIT_2",
nandgate	0:6dee052a3fa4	64	"CLOSE_WAIT",
nandgate	0:6dee052a3fa4	65	"CLOSING",
nandgate	0:6dee052a3fa4	66	"LAST_ACK",
nandgate	0:6dee052a3fa4	67	"TIME_WAIT"
nandgate	0:6dee052a3fa4	68	};
nandgate	0:6dee052a3fa4	69
nandgate	0:6dee052a3fa4	70	/* Incremented every coarse grained timer shot (typically every 500 ms). */
nandgate	0:6dee052a3fa4	71	u32_t tcp_ticks;
nandgate	0:6dee052a3fa4	72	const u8_t tcp_backoff[13] =
nandgate	0:6dee052a3fa4	73	{ 1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7};
nandgate	0:6dee052a3fa4	74	/* Times per slowtmr hits */
nandgate	0:6dee052a3fa4	75	const u8_t tcp_persist_backoff[7] = { 3, 6, 12, 24, 48, 96, 120 };
nandgate	0:6dee052a3fa4	76
nandgate	0:6dee052a3fa4	77	/* The TCP PCB lists. */
nandgate	0:6dee052a3fa4	78
nandgate	0:6dee052a3fa4	79	/** List of all TCP PCBs bound but not yet (connected \|\| listening) */
nandgate	0:6dee052a3fa4	80	struct tcp_pcb *tcp_bound_pcbs;
nandgate	0:6dee052a3fa4	81	/** List of all TCP PCBs in LISTEN state */
nandgate	0:6dee052a3fa4	82	union tcp_listen_pcbs_t tcp_listen_pcbs;
nandgate	0:6dee052a3fa4	83	/** List of all TCP PCBs that are in a state in which
nandgate	0:6dee052a3fa4	84	* they accept or send data. */
nandgate	0:6dee052a3fa4	85	struct tcp_pcb *tcp_active_pcbs;
nandgate	0:6dee052a3fa4	86	/** List of all TCP PCBs in TIME-WAIT state */
nandgate	0:6dee052a3fa4	87	struct tcp_pcb *tcp_tw_pcbs;
nandgate	0:6dee052a3fa4	88
nandgate	0:6dee052a3fa4	89	struct tcp_pcb *tcp_tmp_pcb;
nandgate	0:6dee052a3fa4	90
nandgate	0:6dee052a3fa4	91	static u8_t tcp_timer;
nandgate	0:6dee052a3fa4	92	static u16_t tcp_new_port(void);
nandgate	0:6dee052a3fa4	93
nandgate	0:6dee052a3fa4	94	/**
nandgate	0:6dee052a3fa4	95	* Called periodically to dispatch TCP timers.
nandgate	0:6dee052a3fa4	96	*
nandgate	0:6dee052a3fa4	97	*/
nandgate	0:6dee052a3fa4	98	void
nandgate	0:6dee052a3fa4	99	tcp_tmr(void)
nandgate	0:6dee052a3fa4	100	{
nandgate	0:6dee052a3fa4	101	/* Call tcp_fasttmr() every 250 ms */
nandgate	0:6dee052a3fa4	102	tcp_fasttmr();
nandgate	0:6dee052a3fa4	103
nandgate	0:6dee052a3fa4	104	if (++tcp_timer & 1) {
nandgate	0:6dee052a3fa4	105	/* Call tcp_tmr() every 500 ms, i.e., every other timer
nandgate	0:6dee052a3fa4	106	tcp_tmr() is called. */
nandgate	0:6dee052a3fa4	107	tcp_slowtmr();
nandgate	0:6dee052a3fa4	108	}
nandgate	0:6dee052a3fa4	109	}
nandgate	0:6dee052a3fa4	110
nandgate	0:6dee052a3fa4	111	/**
nandgate	0:6dee052a3fa4	112	* Closes the connection held by the PCB.
nandgate	0:6dee052a3fa4	113	*
nandgate	0:6dee052a3fa4	114	* Listening pcbs are freed and may not be referenced any more.
nandgate	0:6dee052a3fa4	115	* Connection pcbs are freed if not yet connected and may not be referenced
nandgate	0:6dee052a3fa4	116	* any more. If a connection is established (at least SYN received or in
nandgate	0:6dee052a3fa4	117	* a closing state), the connection is closed, and put in a closing state.
nandgate	0:6dee052a3fa4	118	* The pcb is then automatically freed in tcp_slowtmr(). It is therefore
nandgate	0:6dee052a3fa4	119	* unsafe to reference it.
nandgate	0:6dee052a3fa4	120	*
nandgate	0:6dee052a3fa4	121	* @param pcb the tcp_pcb to close
nandgate	0:6dee052a3fa4	122	* @return ERR_OK if connection has been closed
nandgate	0:6dee052a3fa4	123	* another err_t if closing failed and pcb is not freed
nandgate	0:6dee052a3fa4	124	*/
nandgate	0:6dee052a3fa4	125	err_t
nandgate	0:6dee052a3fa4	126	tcp_close(struct tcp_pcb *pcb)
nandgate	0:6dee052a3fa4	127	{
nandgate	0:6dee052a3fa4	128	err_t err;
nandgate	0:6dee052a3fa4	129
nandgate	0:6dee052a3fa4	130	#if TCP_DEBUG
nandgate	0:6dee052a3fa4	131	LWIP_DEBUGF(TCP_DEBUG, ("tcp_close: closing in "));
nandgate	0:6dee052a3fa4	132	tcp_debug_print_state(pcb->state);
nandgate	0:6dee052a3fa4	133	#endif /* TCP_DEBUG */
nandgate	0:6dee052a3fa4	134
nandgate	0:6dee052a3fa4	135	switch (pcb->state) {
nandgate	0:6dee052a3fa4	136	case CLOSED:
nandgate	0:6dee052a3fa4	137	/* Closing a pcb in the CLOSED state might seem erroneous,
nandgate	0:6dee052a3fa4	138	* however, it is in this state once allocated and as yet unused
nandgate	0:6dee052a3fa4	139	* and the user needs some way to free it should the need arise.
nandgate	0:6dee052a3fa4	140	* Calling tcp_close() with a pcb that has already been closed, (i.e. twice)
nandgate	0:6dee052a3fa4	141	* or for a pcb that has been used and then entered the CLOSED state
nandgate	0:6dee052a3fa4	142	* is erroneous, but this should never happen as the pcb has in those cases
nandgate	0:6dee052a3fa4	143	* been freed, and so any remaining handles are bogus. */
nandgate	0:6dee052a3fa4	144	err = ERR_OK;
nandgate	0:6dee052a3fa4	145	TCP_RMV(&tcp_bound_pcbs, pcb);
nandgate	0:6dee052a3fa4	146	memp_free(MEMP_TCP_PCB, pcb);
nandgate	0:6dee052a3fa4	147	pcb = NULL;
nandgate	0:6dee052a3fa4	148	break;
nandgate	0:6dee052a3fa4	149	case LISTEN:
nandgate	0:6dee052a3fa4	150	err = ERR_OK;
nandgate	0:6dee052a3fa4	151	tcp_pcb_remove((struct tcp_pcb **)&tcp_listen_pcbs.pcbs, pcb);
nandgate	0:6dee052a3fa4	152	memp_free(MEMP_TCP_PCB_LISTEN, pcb);
nandgate	0:6dee052a3fa4	153	pcb = NULL;
nandgate	0:6dee052a3fa4	154	break;
nandgate	0:6dee052a3fa4	155	case SYN_SENT:
nandgate	0:6dee052a3fa4	156	err = ERR_OK;
nandgate	0:6dee052a3fa4	157	tcp_pcb_remove(&tcp_active_pcbs, pcb);
nandgate	0:6dee052a3fa4	158	memp_free(MEMP_TCP_PCB, pcb);
nandgate	0:6dee052a3fa4	159	pcb = NULL;
nandgate	0:6dee052a3fa4	160	snmp_inc_tcpattemptfails();
nandgate	0:6dee052a3fa4	161	break;
nandgate	0:6dee052a3fa4	162	case SYN_RCVD:
nandgate	0:6dee052a3fa4	163	err = tcp_send_ctrl(pcb, TCP_FIN);
nandgate	0:6dee052a3fa4	164	if (err == ERR_OK) {
nandgate	0:6dee052a3fa4	165	snmp_inc_tcpattemptfails();
nandgate	0:6dee052a3fa4	166	pcb->state = FIN_WAIT_1;
nandgate	0:6dee052a3fa4	167	}
nandgate	0:6dee052a3fa4	168	break;
nandgate	0:6dee052a3fa4	169	case ESTABLISHED:
nandgate	0:6dee052a3fa4	170	err = tcp_send_ctrl(pcb, TCP_FIN);
nandgate	0:6dee052a3fa4	171	if (err == ERR_OK) {
nandgate	0:6dee052a3fa4	172	snmp_inc_tcpestabresets();
nandgate	0:6dee052a3fa4	173	pcb->state = FIN_WAIT_1;
nandgate	0:6dee052a3fa4	174	}
nandgate	0:6dee052a3fa4	175	break;
nandgate	0:6dee052a3fa4	176	case CLOSE_WAIT:
nandgate	0:6dee052a3fa4	177	err = tcp_send_ctrl(pcb, TCP_FIN);
nandgate	0:6dee052a3fa4	178	if (err == ERR_OK) {
nandgate	0:6dee052a3fa4	179	snmp_inc_tcpestabresets();
nandgate	0:6dee052a3fa4	180	pcb->state = LAST_ACK;
nandgate	0:6dee052a3fa4	181	}
nandgate	0:6dee052a3fa4	182	break;
nandgate	0:6dee052a3fa4	183	default:
nandgate	0:6dee052a3fa4	184	/* Has already been closed, do nothing. */
nandgate	0:6dee052a3fa4	185	err = ERR_OK;
nandgate	0:6dee052a3fa4	186	pcb = NULL;
nandgate	0:6dee052a3fa4	187	break;
nandgate	0:6dee052a3fa4	188	}
nandgate	0:6dee052a3fa4	189
nandgate	0:6dee052a3fa4	190	if (pcb != NULL && err == ERR_OK) {
nandgate	0:6dee052a3fa4	191	/* To ensure all data has been sent when tcp_close returns, we have
nandgate	0:6dee052a3fa4	192	to make sure tcp_output doesn't fail.
nandgate	0:6dee052a3fa4	193	Since we don't really have to ensure all data has been sent when tcp_close
nandgate	0:6dee052a3fa4	194	returns (unsent data is sent from tcp timer functions, also), we don't care
nandgate	0:6dee052a3fa4	195	for the return value of tcp_output for now. */
nandgate	0:6dee052a3fa4	196	/* @todo: When implementing SO_LINGER, this must be changed somehow:
nandgate	0:6dee052a3fa4	197	If SOF_LINGER is set, the data should be sent when tcp_close returns. */
nandgate	0:6dee052a3fa4	198	tcp_output(pcb);
nandgate	0:6dee052a3fa4	199	}
nandgate	0:6dee052a3fa4	200	return err;
nandgate	0:6dee052a3fa4	201	}
nandgate	0:6dee052a3fa4	202
nandgate	0:6dee052a3fa4	203	/**
nandgate	0:6dee052a3fa4	204	* Abandons a connection and optionally sends a RST to the remote
nandgate	0:6dee052a3fa4	205	* host. Deletes the local protocol control block. This is done when
nandgate	0:6dee052a3fa4	206	* a connection is killed because of shortage of memory.
nandgate	0:6dee052a3fa4	207	*
nandgate	0:6dee052a3fa4	208	* @param pcb the tcp_pcb to abort
nandgate	0:6dee052a3fa4	209	* @param reset boolean to indicate whether a reset should be sent
nandgate	0:6dee052a3fa4	210	*/
nandgate	0:6dee052a3fa4	211	void
nandgate	0:6dee052a3fa4	212	tcp_abandon(struct tcp_pcb *pcb, int reset)
nandgate	0:6dee052a3fa4	213	{
nandgate	0:6dee052a3fa4	214	u32_t seqno, ackno;
nandgate	0:6dee052a3fa4	215	u16_t remote_port, local_port;
nandgate	0:6dee052a3fa4	216	struct ip_addr remote_ip, local_ip;
nandgate	0:6dee052a3fa4	217	#if LWIP_CALLBACK_API
nandgate	0:6dee052a3fa4	218	void (* errf)(void *arg, err_t err);
nandgate	0:6dee052a3fa4	219	#endif /* LWIP_CALLBACK_API */
nandgate	0:6dee052a3fa4	220	void *errf_arg;
nandgate	0:6dee052a3fa4	221
nandgate	0:6dee052a3fa4	222
nandgate	0:6dee052a3fa4	223	/* Figure out on which TCP PCB list we are, and remove us. If we
nandgate	0:6dee052a3fa4	224	are in an active state, call the receive function associated with
nandgate	0:6dee052a3fa4	225	the PCB with a NULL argument, and send an RST to the remote end. */
nandgate	0:6dee052a3fa4	226	if (pcb->state == TIME_WAIT) {
nandgate	0:6dee052a3fa4	227	tcp_pcb_remove(&tcp_tw_pcbs, pcb);
nandgate	0:6dee052a3fa4	228	memp_free(MEMP_TCP_PCB, pcb);
nandgate	0:6dee052a3fa4	229	} else {
nandgate	0:6dee052a3fa4	230	seqno = pcb->snd_nxt;
nandgate	0:6dee052a3fa4	231	ackno = pcb->rcv_nxt;
nandgate	0:6dee052a3fa4	232	ip_addr_set(&local_ip, &(pcb->local_ip));
nandgate	0:6dee052a3fa4	233	ip_addr_set(&remote_ip, &(pcb->remote_ip));
nandgate	0:6dee052a3fa4	234	local_port = pcb->local_port;
nandgate	0:6dee052a3fa4	235	remote_port = pcb->remote_port;
nandgate	0:6dee052a3fa4	236	#if LWIP_CALLBACK_API
nandgate	0:6dee052a3fa4	237	errf = pcb->errf;
nandgate	0:6dee052a3fa4	238	#endif /* LWIP_CALLBACK_API */
nandgate	0:6dee052a3fa4	239	errf_arg = pcb->callback_arg;
nandgate	0:6dee052a3fa4	240	tcp_pcb_remove(&tcp_active_pcbs, pcb);
nandgate	0:6dee052a3fa4	241	if (pcb->unacked != NULL) {
nandgate	0:6dee052a3fa4	242	tcp_segs_free(pcb->unacked);
nandgate	0:6dee052a3fa4	243	}
nandgate	0:6dee052a3fa4	244	if (pcb->unsent != NULL) {
nandgate	0:6dee052a3fa4	245	tcp_segs_free(pcb->unsent);
nandgate	0:6dee052a3fa4	246	}
nandgate	0:6dee052a3fa4	247	#if TCP_QUEUE_OOSEQ
nandgate	0:6dee052a3fa4	248	if (pcb->ooseq != NULL) {
nandgate	0:6dee052a3fa4	249	tcp_segs_free(pcb->ooseq);
nandgate	0:6dee052a3fa4	250	}
nandgate	0:6dee052a3fa4	251	#endif /* TCP_QUEUE_OOSEQ */
nandgate	0:6dee052a3fa4	252	memp_free(MEMP_TCP_PCB, pcb);
nandgate	0:6dee052a3fa4	253	TCP_EVENT_ERR(errf, errf_arg, ERR_ABRT);
nandgate	0:6dee052a3fa4	254	if (reset) {
nandgate	0:6dee052a3fa4	255	LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_abandon: sending RST\n"));
nandgate	0:6dee052a3fa4	256	tcp_rst(seqno, ackno, &local_ip, &remote_ip, local_port, remote_port);
nandgate	0:6dee052a3fa4	257	}
nandgate	0:6dee052a3fa4	258	}
nandgate	0:6dee052a3fa4	259	}
nandgate	0:6dee052a3fa4	260
nandgate	0:6dee052a3fa4	261	/**
nandgate	0:6dee052a3fa4	262	* Binds the connection to a local portnumber and IP address. If the
nandgate	0:6dee052a3fa4	263	* IP address is not given (i.e., ipaddr == NULL), the IP address of
nandgate	0:6dee052a3fa4	264	* the outgoing network interface is used instead.
nandgate	0:6dee052a3fa4	265	*
nandgate	0:6dee052a3fa4	266	* @param pcb the tcp_pcb to bind (no check is done whether this pcb is
nandgate	0:6dee052a3fa4	267	* already bound!)
nandgate	0:6dee052a3fa4	268	* @param ipaddr the local ip address to bind to (use IP_ADDR_ANY to bind
nandgate	0:6dee052a3fa4	269	* to any local address
nandgate	0:6dee052a3fa4	270	* @param port the local port to bind to
nandgate	0:6dee052a3fa4	271	* @return ERR_USE if the port is already in use
nandgate	0:6dee052a3fa4	272	* ERR_OK if bound
nandgate	0:6dee052a3fa4	273	*/
nandgate	0:6dee052a3fa4	274	err_t
nandgate	0:6dee052a3fa4	275	tcp_bind(struct tcp_pcb pcb, struct ip_addr ipaddr, u16_t port)
nandgate	0:6dee052a3fa4	276	{
nandgate	0:6dee052a3fa4	277	struct tcp_pcb *cpcb;
nandgate	0:6dee052a3fa4	278
nandgate	0:6dee052a3fa4	279	LWIP_ERROR("tcp_bind: can only bind in state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
nandgate	0:6dee052a3fa4	280
nandgate	0:6dee052a3fa4	281	if (port == 0) {
nandgate	0:6dee052a3fa4	282	port = tcp_new_port();
nandgate	0:6dee052a3fa4	283	}
nandgate	0:6dee052a3fa4	284	/* Check if the address already is in use. */
nandgate	0:6dee052a3fa4	285	/* Check the listen pcbs. */
nandgate	0:6dee052a3fa4	286	for(cpcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs;
nandgate	0:6dee052a3fa4	287	cpcb != NULL; cpcb = cpcb->next) {
nandgate	0:6dee052a3fa4	288	if (cpcb->local_port == port) {
nandgate	0:6dee052a3fa4	289	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
nandgate	0:6dee052a3fa4	290	ip_addr_isany(ipaddr) \|\|
nandgate	0:6dee052a3fa4	291	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
nandgate	0:6dee052a3fa4	292	return ERR_USE;
nandgate	0:6dee052a3fa4	293	}
nandgate	0:6dee052a3fa4	294	}
nandgate	0:6dee052a3fa4	295	}
nandgate	0:6dee052a3fa4	296	/* Check the connected pcbs. */
nandgate	0:6dee052a3fa4	297	for(cpcb = tcp_active_pcbs;
nandgate	0:6dee052a3fa4	298	cpcb != NULL; cpcb = cpcb->next) {
nandgate	0:6dee052a3fa4	299	if (cpcb->local_port == port) {
nandgate	0:6dee052a3fa4	300	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
nandgate	0:6dee052a3fa4	301	ip_addr_isany(ipaddr) \|\|
nandgate	0:6dee052a3fa4	302	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
nandgate	0:6dee052a3fa4	303	return ERR_USE;
nandgate	0:6dee052a3fa4	304	}
nandgate	0:6dee052a3fa4	305	}
nandgate	0:6dee052a3fa4	306	}
nandgate	0:6dee052a3fa4	307	/* Check the bound, not yet connected pcbs. */
nandgate	0:6dee052a3fa4	308	for(cpcb = tcp_bound_pcbs; cpcb != NULL; cpcb = cpcb->next) {
nandgate	0:6dee052a3fa4	309	if (cpcb->local_port == port) {
nandgate	0:6dee052a3fa4	310	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
nandgate	0:6dee052a3fa4	311	ip_addr_isany(ipaddr) \|\|
nandgate	0:6dee052a3fa4	312	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
nandgate	0:6dee052a3fa4	313	return ERR_USE;
nandgate	0:6dee052a3fa4	314	}
nandgate	0:6dee052a3fa4	315	}
nandgate	0:6dee052a3fa4	316	}
nandgate	0:6dee052a3fa4	317	/* @todo: until SO_REUSEADDR is implemented (see task #6995 on savannah),
nandgate	0:6dee052a3fa4	318	* we have to check the pcbs in TIME-WAIT state, also: */
nandgate	0:6dee052a3fa4	319	for(cpcb = tcp_tw_pcbs; cpcb != NULL; cpcb = cpcb->next) {
nandgate	0:6dee052a3fa4	320	if (cpcb->local_port == port) {
nandgate	0:6dee052a3fa4	321	if (ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
nandgate	0:6dee052a3fa4	322	return ERR_USE;
nandgate	0:6dee052a3fa4	323	}
nandgate	0:6dee052a3fa4	324	}
nandgate	0:6dee052a3fa4	325	}
nandgate	0:6dee052a3fa4	326
nandgate	0:6dee052a3fa4	327	if (!ip_addr_isany(ipaddr)) {
nandgate	0:6dee052a3fa4	328	pcb->local_ip = *ipaddr;
nandgate	0:6dee052a3fa4	329	}
nandgate	0:6dee052a3fa4	330	pcb->local_port = port;
nandgate	0:6dee052a3fa4	331	TCP_REG(&tcp_bound_pcbs, pcb);
nandgate	0:6dee052a3fa4	332	LWIP_DEBUGF(TCP_DEBUG, ("tcp_bind: bind to port %"U16_F"\n", port));
nandgate	0:6dee052a3fa4	333	return ERR_OK;
nandgate	0:6dee052a3fa4	334	}
nandgate	0:6dee052a3fa4	335	#if LWIP_CALLBACK_API
nandgate	0:6dee052a3fa4	336	/**
nandgate	0:6dee052a3fa4	337	* Default accept callback if no accept callback is specified by the user.
nandgate	0:6dee052a3fa4	338	*/
nandgate	0:6dee052a3fa4	339	static err_t
nandgate	0:6dee052a3fa4	340	tcp_accept_null(void arg, struct tcp_pcb pcb, err_t err)
nandgate	0:6dee052a3fa4	341	{
nandgate	0:6dee052a3fa4	342	LWIP_UNUSED_ARG(arg);
nandgate	0:6dee052a3fa4	343	LWIP_UNUSED_ARG(pcb);
nandgate	0:6dee052a3fa4	344	LWIP_UNUSED_ARG(err);
nandgate	0:6dee052a3fa4	345
nandgate	0:6dee052a3fa4	346	return ERR_ABRT;
nandgate	0:6dee052a3fa4	347	}
nandgate	0:6dee052a3fa4	348	#endif /* LWIP_CALLBACK_API */
nandgate	0:6dee052a3fa4	349
nandgate	0:6dee052a3fa4	350	/**
nandgate	0:6dee052a3fa4	351	* Set the state of the connection to be LISTEN, which means that it
nandgate	0:6dee052a3fa4	352	* is able to accept incoming connections. The protocol control block
nandgate	0:6dee052a3fa4	353	* is reallocated in order to consume less memory. Setting the
nandgate	0:6dee052a3fa4	354	* connection to LISTEN is an irreversible process.
nandgate	0:6dee052a3fa4	355	*
nandgate	0:6dee052a3fa4	356	* @param pcb the original tcp_pcb
nandgate	0:6dee052a3fa4	357	* @param backlog the incoming connections queue limit
nandgate	0:6dee052a3fa4	358	* @return tcp_pcb used for listening, consumes less memory.
nandgate	0:6dee052a3fa4	359	*
nandgate	0:6dee052a3fa4	360	* @note The original tcp_pcb is freed. This function therefore has to be
nandgate	0:6dee052a3fa4	361	* called like this:
nandgate	0:6dee052a3fa4	362	* tpcb = tcp_listen(tpcb);
nandgate	0:6dee052a3fa4	363	*/
nandgate	0:6dee052a3fa4	364	struct tcp_pcb *
nandgate	0:6dee052a3fa4	365	tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog)
nandgate	0:6dee052a3fa4	366	{
nandgate	0:6dee052a3fa4	367	struct tcp_pcb_listen *lpcb;
nandgate	0:6dee052a3fa4	368
nandgate	0:6dee052a3fa4	369	LWIP_UNUSED_ARG(backlog);
nandgate	0:6dee052a3fa4	370	LWIP_ERROR("tcp_listen: pcb already connected", pcb->state == CLOSED, return NULL);
nandgate	0:6dee052a3fa4	371
nandgate	0:6dee052a3fa4	372	/* already listening? */
nandgate	0:6dee052a3fa4	373	if (pcb->state == LISTEN) {
nandgate	0:6dee052a3fa4	374	return pcb;
nandgate	0:6dee052a3fa4	375	}
nandgate	0:6dee052a3fa4	376	lpcb = (struct tcp_pcb_listen *)memp_malloc(MEMP_TCP_PCB_LISTEN);
nandgate	0:6dee052a3fa4	377	if (lpcb == NULL) {
nandgate	0:6dee052a3fa4	378	return NULL;
nandgate	0:6dee052a3fa4	379	}
nandgate	0:6dee052a3fa4	380	lpcb->callback_arg = pcb->callback_arg;
nandgate	0:6dee052a3fa4	381	lpcb->local_port = pcb->local_port;
nandgate	0:6dee052a3fa4	382	lpcb->state = LISTEN;
nandgate	0:6dee052a3fa4	383	lpcb->so_options = pcb->so_options;
nandgate	0:6dee052a3fa4	384	lpcb->so_options \|= SOF_ACCEPTCONN;
nandgate	0:6dee052a3fa4	385	lpcb->ttl = pcb->ttl;
nandgate	0:6dee052a3fa4	386	lpcb->tos = pcb->tos;
nandgate	0:6dee052a3fa4	387	ip_addr_set(&lpcb->local_ip, &pcb->local_ip);
nandgate	0:6dee052a3fa4	388	TCP_RMV(&tcp_bound_pcbs, pcb);
nandgate	0:6dee052a3fa4	389	memp_free(MEMP_TCP_PCB, pcb);
nandgate	0:6dee052a3fa4	390	#if LWIP_CALLBACK_API
nandgate	0:6dee052a3fa4	391	lpcb->accept = tcp_accept_null;
nandgate	0:6dee052a3fa4	392	#endif /* LWIP_CALLBACK_API */
nandgate	0:6dee052a3fa4	393	#if TCP_LISTEN_BACKLOG
nandgate	0:6dee052a3fa4	394	lpcb->accepts_pending = 0;
nandgate	0:6dee052a3fa4	395	lpcb->backlog = (backlog ? backlog : 1);
nandgate	0:6dee052a3fa4	396	#endif /* TCP_LISTEN_BACKLOG */
nandgate	0:6dee052a3fa4	397	TCP_REG(&tcp_listen_pcbs.listen_pcbs, lpcb);
nandgate	0:6dee052a3fa4	398	return (struct tcp_pcb *)lpcb;
nandgate	0:6dee052a3fa4	399	}
nandgate	0:6dee052a3fa4	400
nandgate	0:6dee052a3fa4	401	/**
nandgate	0:6dee052a3fa4	402	* Update the state that tracks the available window space to advertise.
nandgate	0:6dee052a3fa4	403	*
nandgate	0:6dee052a3fa4	404	* Returns how much extra window would be advertised if we sent an
nandgate	0:6dee052a3fa4	405	* update now.
nandgate	0:6dee052a3fa4	406	*/
nandgate	0:6dee052a3fa4	407	u32_t tcp_update_rcv_ann_wnd(struct tcp_pcb *pcb)
nandgate	0:6dee052a3fa4	408	{
nandgate	0:6dee052a3fa4	409	u32_t new_right_edge = pcb->rcv_nxt + pcb->rcv_wnd;
nandgate	0:6dee052a3fa4	410
nandgate	0:6dee052a3fa4	411	if (TCP_SEQ_GEQ(new_right_edge, pcb->rcv_ann_right_edge + LWIP_MIN((TCP_WND / 2), pcb->mss))) {
nandgate	0:6dee052a3fa4	412	/* we can advertise more window */
nandgate	0:6dee052a3fa4	413	pcb->rcv_ann_wnd = pcb->rcv_wnd;
nandgate	0:6dee052a3fa4	414	return new_right_edge - pcb->rcv_ann_right_edge;
nandgate	0:6dee052a3fa4	415	} else {
nandgate	0:6dee052a3fa4	416	if (TCP_SEQ_GT(pcb->rcv_nxt, pcb->rcv_ann_right_edge)) {
nandgate	0:6dee052a3fa4	417	/* Can happen due to other end sending out of advertised window,
nandgate	0:6dee052a3fa4	418	* but within actual available (but not yet advertised) window */
nandgate	0:6dee052a3fa4	419	pcb->rcv_ann_wnd = 0;
nandgate	0:6dee052a3fa4	420	} else {
nandgate	0:6dee052a3fa4	421	/* keep the right edge of window constant */
nandgate	0:6dee052a3fa4	422	pcb->rcv_ann_wnd = pcb->rcv_ann_right_edge - pcb->rcv_nxt;
nandgate	0:6dee052a3fa4	423	}
nandgate	0:6dee052a3fa4	424	return 0;
nandgate	0:6dee052a3fa4	425	}
nandgate	0:6dee052a3fa4	426	}
nandgate	0:6dee052a3fa4	427
nandgate	0:6dee052a3fa4	428	/**
nandgate	0:6dee052a3fa4	429	* This function should be called by the application when it has
nandgate	0:6dee052a3fa4	430	* processed the data. The purpose is to advertise a larger window
nandgate	0:6dee052a3fa4	431	* when the data has been processed.
nandgate	0:6dee052a3fa4	432	*
nandgate	0:6dee052a3fa4	433	* @param pcb the tcp_pcb for which data is read
nandgate	0:6dee052a3fa4	434	* @param len the amount of bytes that have been read by the application
nandgate	0:6dee052a3fa4	435	*/
nandgate	0:6dee052a3fa4	436	void
nandgate	0:6dee052a3fa4	437	tcp_recved(struct tcp_pcb *pcb, u16_t len)
nandgate	0:6dee052a3fa4	438	{
nandgate	0:6dee052a3fa4	439	int wnd_inflation;
nandgate	0:6dee052a3fa4	440
nandgate	0:6dee052a3fa4	441	LWIP_ASSERT("tcp_recved: len would wrap rcv_wnd\n",
nandgate	0:6dee052a3fa4	442	len <= 0xffff - pcb->rcv_wnd );
nandgate	0:6dee052a3fa4	443
nandgate	0:6dee052a3fa4	444	pcb->rcv_wnd += len;
nandgate	0:6dee052a3fa4	445	if (pcb->rcv_wnd > TCP_WND)
nandgate	0:6dee052a3fa4	446	pcb->rcv_wnd = TCP_WND;
nandgate	0:6dee052a3fa4	447
nandgate	0:6dee052a3fa4	448	wnd_inflation = tcp_update_rcv_ann_wnd(pcb);
nandgate	0:6dee052a3fa4	449
nandgate	0:6dee052a3fa4	450	/* If the change in the right edge of window is significant (default
nandgate	0:6dee052a3fa4	451	* watermark is TCP_WND/2), then send an explicit update now.
nandgate	0:6dee052a3fa4	452	* Otherwise wait for a packet to be sent in the normal course of
nandgate	0:6dee052a3fa4	453	* events (or more window to be available later) */
nandgate	0:6dee052a3fa4	454	if (wnd_inflation >= TCP_WND_UPDATE_THRESHOLD)
nandgate	0:6dee052a3fa4	455	tcp_ack_now(pcb);
nandgate	0:6dee052a3fa4	456
nandgate	0:6dee052a3fa4	457	LWIP_DEBUGF(TCP_DEBUG, ("tcp_recved: recveived %"U16_F" bytes, wnd %"U16_F" (%"U16_F").\n",
nandgate	0:6dee052a3fa4	458	len, pcb->rcv_wnd, TCP_WND - pcb->rcv_wnd));
nandgate	0:6dee052a3fa4	459	}
nandgate	0:6dee052a3fa4	460
nandgate	0:6dee052a3fa4	461	/**
nandgate	0:6dee052a3fa4	462	* A nastly hack featuring 'goto' statements that allocates a
nandgate	0:6dee052a3fa4	463	* new TCP local port.
nandgate	0:6dee052a3fa4	464	*
nandgate	0:6dee052a3fa4	465	* @return a new (free) local TCP port number
nandgate	0:6dee052a3fa4	466	*/
nandgate	0:6dee052a3fa4	467	static u16_t
nandgate	0:6dee052a3fa4	468	tcp_new_port(void)
nandgate	0:6dee052a3fa4	469	{
nandgate	0:6dee052a3fa4	470	struct tcp_pcb *pcb;
nandgate	0:6dee052a3fa4	471	#ifndef TCP_LOCAL_PORT_RANGE_START
nandgate	0:6dee052a3fa4	472	#define TCP_LOCAL_PORT_RANGE_START 4096
nandgate	0:6dee052a3fa4	473	#define TCP_LOCAL_PORT_RANGE_END 0x7fff
nandgate	0:6dee052a3fa4	474	#endif
nandgate	0:6dee052a3fa4	475	static u16_t port = TCP_LOCAL_PORT_RANGE_START;
nandgate	0:6dee052a3fa4	476
nandgate	0:6dee052a3fa4	477	again:
nandgate	0:6dee052a3fa4	478	if (++port > TCP_LOCAL_PORT_RANGE_END) {
nandgate	0:6dee052a3fa4	479	port = TCP_LOCAL_PORT_RANGE_START;
nandgate	0:6dee052a3fa4	480	}
nandgate	0:6dee052a3fa4	481
nandgate	0:6dee052a3fa4	482	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
nandgate	0:6dee052a3fa4	483	if (pcb->local_port == port) {
nandgate	0:6dee052a3fa4	484	goto again;
nandgate	0:6dee052a3fa4	485	}
nandgate	0:6dee052a3fa4	486	}
nandgate	0:6dee052a3fa4	487	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
nandgate	0:6dee052a3fa4	488	if (pcb->local_port == port) {
nandgate	0:6dee052a3fa4	489	goto again;
nandgate	0:6dee052a3fa4	490	}
nandgate	0:6dee052a3fa4	491	}
nandgate	0:6dee052a3fa4	492	for(pcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs; pcb != NULL; pcb = pcb->next) {
nandgate	0:6dee052a3fa4	493	if (pcb->local_port == port) {
nandgate	0:6dee052a3fa4	494	goto again;
nandgate	0:6dee052a3fa4	495	}
nandgate	0:6dee052a3fa4	496	}
nandgate	0:6dee052a3fa4	497	return port;
nandgate	0:6dee052a3fa4	498	}
nandgate	0:6dee052a3fa4	499
nandgate	0:6dee052a3fa4	500	/**
nandgate	0:6dee052a3fa4	501	* Connects to another host. The function given as the "connected"
nandgate	0:6dee052a3fa4	502	* argument will be called when the connection has been established.
nandgate	0:6dee052a3fa4	503	*
nandgate	0:6dee052a3fa4	504	* @param pcb the tcp_pcb used to establish the connection
nandgate	0:6dee052a3fa4	505	* @param ipaddr the remote ip address to connect to
nandgate	0:6dee052a3fa4	506	* @param port the remote tcp port to connect to
nandgate	0:6dee052a3fa4	507	* @param connected callback function to call when connected (or on error)
nandgate	0:6dee052a3fa4	508	* @return ERR_VAL if invalid arguments are given
nandgate	0:6dee052a3fa4	509	* ERR_OK if connect request has been sent
nandgate	0:6dee052a3fa4	510	* other err_t values if connect request couldn't be sent
nandgate	0:6dee052a3fa4	511	*/
nandgate	0:6dee052a3fa4	512	err_t
nandgate	0:6dee052a3fa4	513	tcp_connect(struct tcp_pcb pcb, struct ip_addr ipaddr, u16_t port,
nandgate	0:6dee052a3fa4	514	err_t (* connected)(void arg, struct tcp_pcb tpcb, err_t err))
nandgate	0:6dee052a3fa4	515	{
nandgate	0:6dee052a3fa4	516	err_t ret;
nandgate	0:6dee052a3fa4	517	u32_t iss;
nandgate	0:6dee052a3fa4	518
nandgate	0:6dee052a3fa4	519	LWIP_ERROR("tcp_connect: can only connected from state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
nandgate	0:6dee052a3fa4	520
nandgate	0:6dee052a3fa4	521	LWIP_DEBUGF(TCP_DEBUG, ("tcp_connect to port %"U16_F"\n", port));
nandgate	0:6dee052a3fa4	522	if (ipaddr != NULL) {
nandgate	0:6dee052a3fa4	523	pcb->remote_ip = *ipaddr;
nandgate	0:6dee052a3fa4	524	} else {
nandgate	0:6dee052a3fa4	525	return ERR_VAL;
nandgate	0:6dee052a3fa4	526	}
nandgate	0:6dee052a3fa4	527	pcb->remote_port = port;
nandgate	0:6dee052a3fa4	528	if (pcb->local_port == 0) {
nandgate	0:6dee052a3fa4	529	pcb->local_port = tcp_new_port();
nandgate	0:6dee052a3fa4	530	}
nandgate	0:6dee052a3fa4	531	iss = tcp_next_iss();
nandgate	0:6dee052a3fa4	532	pcb->rcv_nxt = 0;
nandgate	0:6dee052a3fa4	533	pcb->snd_nxt = iss;
nandgate	0:6dee052a3fa4	534	pcb->lastack = iss - 1;
nandgate	0:6dee052a3fa4	535	pcb->snd_lbb = iss - 1;
nandgate	0:6dee052a3fa4	536	pcb->rcv_wnd = TCP_WND;
nandgate	0:6dee052a3fa4	537	pcb->rcv_ann_wnd = TCP_WND;
nandgate	0:6dee052a3fa4	538	pcb->rcv_ann_right_edge = pcb->rcv_nxt;
nandgate	0:6dee052a3fa4	539	pcb->snd_wnd = TCP_WND;
nandgate	0:6dee052a3fa4	540	/* As initial send MSS, we use TCP_MSS but limit it to 536.
nandgate	0:6dee052a3fa4	541	The send MSS is updated when an MSS option is received. */
nandgate	0:6dee052a3fa4	542	pcb->mss = (TCP_MSS > 536) ? 536 : TCP_MSS;
nandgate	0:6dee052a3fa4	543	#if TCP_CALCULATE_EFF_SEND_MSS
nandgate	0:6dee052a3fa4	544	pcb->mss = tcp_eff_send_mss(pcb->mss, ipaddr);
nandgate	0:6dee052a3fa4	545	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
nandgate	0:6dee052a3fa4	546	pcb->cwnd = 1;
nandgate	0:6dee052a3fa4	547	pcb->ssthresh = pcb->mss * 10;
nandgate	0:6dee052a3fa4	548	pcb->state = SYN_SENT;
nandgate	0:6dee052a3fa4	549	#if LWIP_CALLBACK_API
nandgate	0:6dee052a3fa4	550	pcb->connected = connected;
nandgate	0:6dee052a3fa4	551	#endif /* LWIP_CALLBACK_API */
nandgate	0:6dee052a3fa4	552	TCP_RMV(&tcp_bound_pcbs, pcb);
nandgate	0:6dee052a3fa4	553	TCP_REG(&tcp_active_pcbs, pcb);
nandgate	0:6dee052a3fa4	554
nandgate	0:6dee052a3fa4	555	snmp_inc_tcpactiveopens();
nandgate	0:6dee052a3fa4	556
nandgate	0:6dee052a3fa4	557	ret = tcp_enqueue(pcb, NULL, 0, TCP_SYN, 0, TF_SEG_OPTS_MSS
nandgate	0:6dee052a3fa4	558	#if LWIP_TCP_TIMESTAMPS
nandgate	0:6dee052a3fa4	559	\| TF_SEG_OPTS_TS
nandgate	0:6dee052a3fa4	560	#endif
nandgate	0:6dee052a3fa4	561	);
nandgate	0:6dee052a3fa4	562	if (ret == ERR_OK) {
nandgate	0:6dee052a3fa4	563	tcp_output(pcb);
nandgate	0:6dee052a3fa4	564	}
nandgate	0:6dee052a3fa4	565	return ret;
nandgate	0:6dee052a3fa4	566	}
nandgate	0:6dee052a3fa4	567
nandgate	0:6dee052a3fa4	568	/**
nandgate	0:6dee052a3fa4	569	* Called every 500 ms and implements the retransmission timer and the timer that
nandgate	0:6dee052a3fa4	570	* removes PCBs that have been in TIME-WAIT for enough time. It also increments
nandgate	0:6dee052a3fa4	571	* various timers such as the inactivity timer in each PCB.
nandgate	0:6dee052a3fa4	572	*
nandgate	0:6dee052a3fa4	573	* Automatically called from tcp_tmr().
nandgate	0:6dee052a3fa4	574	*/
nandgate	0:6dee052a3fa4	575	void
nandgate	0:6dee052a3fa4	576	tcp_slowtmr(void)
nandgate	0:6dee052a3fa4	577	{
nandgate	0:6dee052a3fa4	578	struct tcp_pcb pcb, pcb2, *prev;
nandgate	0:6dee052a3fa4	579	u16_t eff_wnd;
nandgate	0:6dee052a3fa4	580	u8_t pcb_remove; /* flag if a PCB should be removed */
nandgate	0:6dee052a3fa4	581	err_t err;
nandgate	0:6dee052a3fa4	582
nandgate	0:6dee052a3fa4	583	err = ERR_OK;
nandgate	0:6dee052a3fa4	584
nandgate	0:6dee052a3fa4	585	++tcp_ticks;
nandgate	0:6dee052a3fa4	586
nandgate	0:6dee052a3fa4	587	/* Steps through all of the active PCBs. */
nandgate	0:6dee052a3fa4	588	prev = NULL;
nandgate	0:6dee052a3fa4	589	pcb = tcp_active_pcbs;
nandgate	0:6dee052a3fa4	590	if (pcb == NULL) {
nandgate	0:6dee052a3fa4	591	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: no active pcbs\n"));
nandgate	0:6dee052a3fa4	592	}
nandgate	0:6dee052a3fa4	593	while (pcb != NULL) {
nandgate	0:6dee052a3fa4	594	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: processing active pcb\n"));
nandgate	0:6dee052a3fa4	595	LWIP_ASSERT("tcp_slowtmr: active pcb->state != CLOSED\n", pcb->state != CLOSED);
nandgate	0:6dee052a3fa4	596	LWIP_ASSERT("tcp_slowtmr: active pcb->state != LISTEN\n", pcb->state != LISTEN);
nandgate	0:6dee052a3fa4	597	LWIP_ASSERT("tcp_slowtmr: active pcb->state != TIME-WAIT\n", pcb->state != TIME_WAIT);
nandgate	0:6dee052a3fa4	598
nandgate	0:6dee052a3fa4	599	pcb_remove = 0;
nandgate	0:6dee052a3fa4	600
nandgate	0:6dee052a3fa4	601	if (pcb->state == SYN_SENT && pcb->nrtx == TCP_SYNMAXRTX) {
nandgate	0:6dee052a3fa4	602	++pcb_remove;
nandgate	0:6dee052a3fa4	603	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max SYN retries reached\n"));
nandgate	0:6dee052a3fa4	604	}
nandgate	0:6dee052a3fa4	605	else if (pcb->nrtx == TCP_MAXRTX) {
nandgate	0:6dee052a3fa4	606	++pcb_remove;
nandgate	0:6dee052a3fa4	607	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max DATA retries reached\n"));
nandgate	0:6dee052a3fa4	608	} else {
nandgate	0:6dee052a3fa4	609	if (pcb->persist_backoff > 0) {
nandgate	0:6dee052a3fa4	610	/* If snd_wnd is zero, use persist timer to send 1 byte probes
nandgate	0:6dee052a3fa4	611	* instead of using the standard retransmission mechanism. */
nandgate	0:6dee052a3fa4	612	pcb->persist_cnt++;
nandgate	0:6dee052a3fa4	613	if (pcb->persist_cnt >= tcp_persist_backoff[pcb->persist_backoff-1]) {
nandgate	0:6dee052a3fa4	614	pcb->persist_cnt = 0;
nandgate	0:6dee052a3fa4	615	if (pcb->persist_backoff < sizeof(tcp_persist_backoff)) {
nandgate	0:6dee052a3fa4	616	pcb->persist_backoff++;
nandgate	0:6dee052a3fa4	617	}
nandgate	0:6dee052a3fa4	618	tcp_zero_window_probe(pcb);
nandgate	0:6dee052a3fa4	619	}
nandgate	0:6dee052a3fa4	620	} else {
nandgate	0:6dee052a3fa4	621	/* Increase the retransmission timer if it is running */
nandgate	0:6dee052a3fa4	622	if(pcb->rtime >= 0)
nandgate	0:6dee052a3fa4	623	++pcb->rtime;
nandgate	0:6dee052a3fa4	624
nandgate	0:6dee052a3fa4	625	if (pcb->unacked != NULL && pcb->rtime >= pcb->rto) {
nandgate	0:6dee052a3fa4	626	/* Time for a retransmission. */
nandgate	0:6dee052a3fa4	627	LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_slowtmr: rtime %"S16_F
nandgate	0:6dee052a3fa4	628	" pcb->rto %"S16_F"\n",
nandgate	0:6dee052a3fa4	629	pcb->rtime, pcb->rto));
nandgate	0:6dee052a3fa4	630
nandgate	0:6dee052a3fa4	631	/* Double retransmission time-out unless we are trying to
nandgate	0:6dee052a3fa4	632	* connect to somebody (i.e., we are in SYN_SENT). */
nandgate	0:6dee052a3fa4	633	if (pcb->state != SYN_SENT) {
nandgate	0:6dee052a3fa4	634	pcb->rto = ((pcb->sa >> 3) + pcb->sv) << tcp_backoff[pcb->nrtx];
nandgate	0:6dee052a3fa4	635	}
nandgate	0:6dee052a3fa4	636
nandgate	0:6dee052a3fa4	637	/* Reset the retransmission timer. */
nandgate	0:6dee052a3fa4	638	pcb->rtime = 0;
nandgate	0:6dee052a3fa4	639
nandgate	0:6dee052a3fa4	640	/* Reduce congestion window and ssthresh. */
nandgate	0:6dee052a3fa4	641	eff_wnd = LWIP_MIN(pcb->cwnd, pcb->snd_wnd);
nandgate	0:6dee052a3fa4	642	pcb->ssthresh = eff_wnd >> 1;
nandgate	0:6dee052a3fa4	643	if (pcb->ssthresh < pcb->mss) {
nandgate	0:6dee052a3fa4	644	pcb->ssthresh = pcb->mss * 2;
nandgate	0:6dee052a3fa4	645	}
nandgate	0:6dee052a3fa4	646	pcb->cwnd = pcb->mss;
nandgate	0:6dee052a3fa4	647	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: cwnd %"U16_F
nandgate	0:6dee052a3fa4	648	" ssthresh %"U16_F"\n",
nandgate	0:6dee052a3fa4	649	pcb->cwnd, pcb->ssthresh));
nandgate	0:6dee052a3fa4	650
nandgate	0:6dee052a3fa4	651	/* The following needs to be called AFTER cwnd is set to one
nandgate	0:6dee052a3fa4	652	mss - STJ */
nandgate	0:6dee052a3fa4	653	tcp_rexmit_rto(pcb);
nandgate	0:6dee052a3fa4	654	}
nandgate	0:6dee052a3fa4	655	}
nandgate	0:6dee052a3fa4	656	}
nandgate	0:6dee052a3fa4	657	/* Check if this PCB has stayed too long in FIN-WAIT-2 */
nandgate	0:6dee052a3fa4	658	if (pcb->state == FIN_WAIT_2) {
nandgate	0:6dee052a3fa4	659	if ((u32_t)(tcp_ticks - pcb->tmr) >
nandgate	0:6dee052a3fa4	660	TCP_FIN_WAIT_TIMEOUT / TCP_SLOW_INTERVAL) {
nandgate	0:6dee052a3fa4	661	++pcb_remove;
nandgate	0:6dee052a3fa4	662	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in FIN-WAIT-2\n"));
nandgate	0:6dee052a3fa4	663	}
nandgate	0:6dee052a3fa4	664	}
nandgate	0:6dee052a3fa4	665
nandgate	0:6dee052a3fa4	666	/* Check if KEEPALIVE should be sent */
nandgate	0:6dee052a3fa4	667	if((pcb->so_options & SOF_KEEPALIVE) &&
nandgate	0:6dee052a3fa4	668	((pcb->state == ESTABLISHED) \|\|
nandgate	0:6dee052a3fa4	669	(pcb->state == CLOSE_WAIT))) {
nandgate	0:6dee052a3fa4	670	#if LWIP_TCP_KEEPALIVE
nandgate	0:6dee052a3fa4	671	if((u32_t)(tcp_ticks - pcb->tmr) >
nandgate	0:6dee052a3fa4	672	(pcb->keep_idle + (pcb->keep_cnt*pcb->keep_intvl))
nandgate	0:6dee052a3fa4	673	/ TCP_SLOW_INTERVAL)
nandgate	0:6dee052a3fa4	674	#else
nandgate	0:6dee052a3fa4	675	if((u32_t)(tcp_ticks - pcb->tmr) >
nandgate	0:6dee052a3fa4	676	(pcb->keep_idle + TCP_MAXIDLE) / TCP_SLOW_INTERVAL)
nandgate	0:6dee052a3fa4	677	#endif /* LWIP_TCP_KEEPALIVE */
nandgate	0:6dee052a3fa4	678	{
nandgate	0:6dee052a3fa4	679	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: KEEPALIVE timeout. Aborting connection to %"U16_F".%"U16_F".%"U16_F".%"U16_F".\n",
nandgate	0:6dee052a3fa4	680	ip4_addr1(&pcb->remote_ip), ip4_addr2(&pcb->remote_ip),
nandgate	0:6dee052a3fa4	681	ip4_addr3(&pcb->remote_ip), ip4_addr4(&pcb->remote_ip)));
nandgate	0:6dee052a3fa4	682
nandgate	0:6dee052a3fa4	683	tcp_abort(pcb);
nandgate	0:6dee052a3fa4	684	}
nandgate	0:6dee052a3fa4	685	#if LWIP_TCP_KEEPALIVE
nandgate	0:6dee052a3fa4	686	else if((u32_t)(tcp_ticks - pcb->tmr) >
nandgate	0:6dee052a3fa4	687	(pcb->keep_idle + pcb->keep_cnt_sent * pcb->keep_intvl)
nandgate	0:6dee052a3fa4	688	/ TCP_SLOW_INTERVAL)
nandgate	0:6dee052a3fa4	689	#else
nandgate	0:6dee052a3fa4	690	else if((u32_t)(tcp_ticks - pcb->tmr) >
nandgate	0:6dee052a3fa4	691	(pcb->keep_idle + pcb->keep_cnt_sent * TCP_KEEPINTVL_DEFAULT)
nandgate	0:6dee052a3fa4	692	/ TCP_SLOW_INTERVAL)
nandgate	0:6dee052a3fa4	693	#endif /* LWIP_TCP_KEEPALIVE */
nandgate	0:6dee052a3fa4	694	{
nandgate	0:6dee052a3fa4	695	tcp_keepalive(pcb);
nandgate	0:6dee052a3fa4	696	pcb->keep_cnt_sent++;
nandgate	0:6dee052a3fa4	697	}
nandgate	0:6dee052a3fa4	698	}
nandgate	0:6dee052a3fa4	699
nandgate	0:6dee052a3fa4	700	/* If this PCB has queued out of sequence data, but has been
nandgate	0:6dee052a3fa4	701	inactive for too long, will drop the data (it will eventually
nandgate	0:6dee052a3fa4	702	be retransmitted). */
nandgate	0:6dee052a3fa4	703	#if TCP_QUEUE_OOSEQ
nandgate	0:6dee052a3fa4	704	if (pcb->ooseq != NULL &&
nandgate	0:6dee052a3fa4	705	(u32_t)tcp_ticks - pcb->tmr >= pcb->rto * TCP_OOSEQ_TIMEOUT) {
nandgate	0:6dee052a3fa4	706	tcp_segs_free(pcb->ooseq);
nandgate	0:6dee052a3fa4	707	pcb->ooseq = NULL;
nandgate	0:6dee052a3fa4	708	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: dropping OOSEQ queued data\n"));
nandgate	0:6dee052a3fa4	709	}
nandgate	0:6dee052a3fa4	710	#endif /* TCP_QUEUE_OOSEQ */
nandgate	0:6dee052a3fa4	711
nandgate	0:6dee052a3fa4	712	/* Check if this PCB has stayed too long in SYN-RCVD */
nandgate	0:6dee052a3fa4	713	if (pcb->state == SYN_RCVD) {
nandgate	0:6dee052a3fa4	714	if ((u32_t)(tcp_ticks - pcb->tmr) >
nandgate	0:6dee052a3fa4	715	TCP_SYN_RCVD_TIMEOUT / TCP_SLOW_INTERVAL) {
nandgate	0:6dee052a3fa4	716	++pcb_remove;
nandgate	0:6dee052a3fa4	717	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in SYN-RCVD\n"));
nandgate	0:6dee052a3fa4	718	}
nandgate	0:6dee052a3fa4	719	}
nandgate	0:6dee052a3fa4	720
nandgate	0:6dee052a3fa4	721	/* Check if this PCB has stayed too long in LAST-ACK */
nandgate	0:6dee052a3fa4	722	if (pcb->state == LAST_ACK) {
nandgate	0:6dee052a3fa4	723	if ((u32_t)(tcp_ticks - pcb->tmr) > 2 * TCP_MSL / TCP_SLOW_INTERVAL) {
nandgate	0:6dee052a3fa4	724	++pcb_remove;
nandgate	0:6dee052a3fa4	725	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in LAST-ACK\n"));
nandgate	0:6dee052a3fa4	726	}
nandgate	0:6dee052a3fa4	727	}
nandgate	0:6dee052a3fa4	728
nandgate	0:6dee052a3fa4	729	/* If the PCB should be removed, do it. */
nandgate	0:6dee052a3fa4	730	if (pcb_remove) {
nandgate	0:6dee052a3fa4	731	tcp_pcb_purge(pcb);
nandgate	0:6dee052a3fa4	732	/* Remove PCB from tcp_active_pcbs list. */
nandgate	0:6dee052a3fa4	733	if (prev != NULL) {
nandgate	0:6dee052a3fa4	734	LWIP_ASSERT("tcp_slowtmr: middle tcp != tcp_active_pcbs", pcb != tcp_active_pcbs);
nandgate	0:6dee052a3fa4	735	prev->next = pcb->next;
nandgate	0:6dee052a3fa4	736	} else {
nandgate	0:6dee052a3fa4	737	/* This PCB was the first. */
nandgate	0:6dee052a3fa4	738	LWIP_ASSERT("tcp_slowtmr: first pcb == tcp_active_pcbs", tcp_active_pcbs == pcb);
nandgate	0:6dee052a3fa4	739	tcp_active_pcbs = pcb->next;
nandgate	0:6dee052a3fa4	740	}
nandgate	0:6dee052a3fa4	741
nandgate	0:6dee052a3fa4	742	TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_ABRT);
nandgate	0:6dee052a3fa4	743
nandgate	0:6dee052a3fa4	744	pcb2 = pcb->next;
nandgate	0:6dee052a3fa4	745	memp_free(MEMP_TCP_PCB, pcb);
nandgate	0:6dee052a3fa4	746	pcb = pcb2;
nandgate	0:6dee052a3fa4	747	} else {
nandgate	0:6dee052a3fa4	748
nandgate	0:6dee052a3fa4	749	/* We check if we should poll the connection. */
nandgate	0:6dee052a3fa4	750	++pcb->polltmr;
nandgate	0:6dee052a3fa4	751	if (pcb->polltmr >= pcb->pollinterval) {
nandgate	0:6dee052a3fa4	752	pcb->polltmr = 0;
nandgate	0:6dee052a3fa4	753	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: polling application\n"));
nandgate	0:6dee052a3fa4	754	TCP_EVENT_POLL(pcb, err);
nandgate	0:6dee052a3fa4	755	if (err == ERR_OK) {
nandgate	0:6dee052a3fa4	756	tcp_output(pcb);
nandgate	0:6dee052a3fa4	757	}
nandgate	0:6dee052a3fa4	758	}
nandgate	0:6dee052a3fa4	759
nandgate	0:6dee052a3fa4	760	prev = pcb;
nandgate	0:6dee052a3fa4	761	pcb = pcb->next;
nandgate	0:6dee052a3fa4	762	}
nandgate	0:6dee052a3fa4	763	}
nandgate	0:6dee052a3fa4	764
nandgate	0:6dee052a3fa4	765
nandgate	0:6dee052a3fa4	766	/* Steps through all of the TIME-WAIT PCBs. */
nandgate	0:6dee052a3fa4	767	prev = NULL;
nandgate	0:6dee052a3fa4	768	pcb = tcp_tw_pcbs;
nandgate	0:6dee052a3fa4	769	while (pcb != NULL) {
nandgate	0:6dee052a3fa4	770	LWIP_ASSERT("tcp_slowtmr: TIME-WAIT pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
nandgate	0:6dee052a3fa4	771	pcb_remove = 0;
nandgate	0:6dee052a3fa4	772
nandgate	0:6dee052a3fa4	773	/* Check if this PCB has stayed long enough in TIME-WAIT */
nandgate	0:6dee052a3fa4	774	if ((u32_t)(tcp_ticks - pcb->tmr) > 2 * TCP_MSL / TCP_SLOW_INTERVAL) {
nandgate	0:6dee052a3fa4	775	++pcb_remove;
nandgate	0:6dee052a3fa4	776	}
nandgate	0:6dee052a3fa4	777
nandgate	0:6dee052a3fa4	778
nandgate	0:6dee052a3fa4	779
nandgate	0:6dee052a3fa4	780	/* If the PCB should be removed, do it. */
nandgate	0:6dee052a3fa4	781	if (pcb_remove) {
nandgate	0:6dee052a3fa4	782	tcp_pcb_purge(pcb);
nandgate	0:6dee052a3fa4	783	/* Remove PCB from tcp_tw_pcbs list. */
nandgate	0:6dee052a3fa4	784	if (prev != NULL) {
nandgate	0:6dee052a3fa4	785	LWIP_ASSERT("tcp_slowtmr: middle tcp != tcp_tw_pcbs", pcb != tcp_tw_pcbs);
nandgate	0:6dee052a3fa4	786	prev->next = pcb->next;
nandgate	0:6dee052a3fa4	787	} else {
nandgate	0:6dee052a3fa4	788	/* This PCB was the first. */
nandgate	0:6dee052a3fa4	789	LWIP_ASSERT("tcp_slowtmr: first pcb == tcp_tw_pcbs", tcp_tw_pcbs == pcb);
nandgate	0:6dee052a3fa4	790	tcp_tw_pcbs = pcb->next;
nandgate	0:6dee052a3fa4	791	}
nandgate	0:6dee052a3fa4	792	pcb2 = pcb->next;
nandgate	0:6dee052a3fa4	793	memp_free(MEMP_TCP_PCB, pcb);
nandgate	0:6dee052a3fa4	794	pcb = pcb2;
nandgate	0:6dee052a3fa4	795	} else {
nandgate	0:6dee052a3fa4	796	prev = pcb;
nandgate	0:6dee052a3fa4	797	pcb = pcb->next;
nandgate	0:6dee052a3fa4	798	}
nandgate	0:6dee052a3fa4	799	}
nandgate	0:6dee052a3fa4	800	}
nandgate	0:6dee052a3fa4	801
nandgate	0:6dee052a3fa4	802	/**
nandgate	0:6dee052a3fa4	803	* Is called every TCP_FAST_INTERVAL (250 ms) and process data previously
nandgate	0:6dee052a3fa4	804	* "refused" by upper layer (application) and sends delayed ACKs.
nandgate	0:6dee052a3fa4	805	*
nandgate	0:6dee052a3fa4	806	* Automatically called from tcp_tmr().
nandgate	0:6dee052a3fa4	807	*/
nandgate	0:6dee052a3fa4	808	void
nandgate	0:6dee052a3fa4	809	tcp_fasttmr(void)
nandgate	0:6dee052a3fa4	810	{
nandgate	0:6dee052a3fa4	811	struct tcp_pcb *pcb;
nandgate	0:6dee052a3fa4	812
nandgate	0:6dee052a3fa4	813	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
nandgate	0:6dee052a3fa4	814	/* If there is data which was previously "refused" by upper layer */
nandgate	0:6dee052a3fa4	815	if (pcb->refused_data != NULL) {
nandgate	0:6dee052a3fa4	816	/* Notify again application with data previously received. */
nandgate	0:6dee052a3fa4	817	err_t err;
nandgate	0:6dee052a3fa4	818	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_fasttmr: notify kept packet\n"));
nandgate	0:6dee052a3fa4	819	TCP_EVENT_RECV(pcb, pcb->refused_data, ERR_OK, err);
nandgate	0:6dee052a3fa4	820	if (err == ERR_OK) {
nandgate	0:6dee052a3fa4	821	pcb->refused_data = NULL;
nandgate	0:6dee052a3fa4	822	}
nandgate	0:6dee052a3fa4	823	}
nandgate	0:6dee052a3fa4	824
nandgate	0:6dee052a3fa4	825	/* send delayed ACKs */
nandgate	0:6dee052a3fa4	826	if (pcb->flags & TF_ACK_DELAY) {
nandgate	0:6dee052a3fa4	827	LWIP_DEBUGF(TCP_DEBUG, ("tcp_fasttmr: delayed ACK\n"));
nandgate	0:6dee052a3fa4	828	tcp_ack_now(pcb);
nandgate	0:6dee052a3fa4	829	pcb->flags &= ~(TF_ACK_DELAY \| TF_ACK_NOW);
nandgate	0:6dee052a3fa4	830	}
nandgate	0:6dee052a3fa4	831	}
nandgate	0:6dee052a3fa4	832	}
nandgate	0:6dee052a3fa4	833
nandgate	0:6dee052a3fa4	834	/**
nandgate	0:6dee052a3fa4	835	* Deallocates a list of TCP segments (tcp_seg structures).
nandgate	0:6dee052a3fa4	836	*
nandgate	0:6dee052a3fa4	837	* @param seg tcp_seg list of TCP segments to free
nandgate	0:6dee052a3fa4	838	* @return the number of pbufs that were deallocated
nandgate	0:6dee052a3fa4	839	*/
nandgate	0:6dee052a3fa4	840	u8_t
nandgate	0:6dee052a3fa4	841	tcp_segs_free(struct tcp_seg *seg)
nandgate	0:6dee052a3fa4	842	{
nandgate	0:6dee052a3fa4	843	u8_t count = 0;
nandgate	0:6dee052a3fa4	844	struct tcp_seg *next;
nandgate	0:6dee052a3fa4	845	while (seg != NULL) {
nandgate	0:6dee052a3fa4	846	next = seg->next;
nandgate	0:6dee052a3fa4	847	count += tcp_seg_free(seg);
nandgate	0:6dee052a3fa4	848	seg = next;
nandgate	0:6dee052a3fa4	849	}
nandgate	0:6dee052a3fa4	850	return count;
nandgate	0:6dee052a3fa4	851	}
nandgate	0:6dee052a3fa4	852
nandgate	0:6dee052a3fa4	853	/**
nandgate	0:6dee052a3fa4	854	* Frees a TCP segment (tcp_seg structure).
nandgate	0:6dee052a3fa4	855	*
nandgate	0:6dee052a3fa4	856	* @param seg single tcp_seg to free
nandgate	0:6dee052a3fa4	857	* @return the number of pbufs that were deallocated
nandgate	0:6dee052a3fa4	858	*/
nandgate	0:6dee052a3fa4	859	u8_t
nandgate	0:6dee052a3fa4	860	tcp_seg_free(struct tcp_seg *seg)
nandgate	0:6dee052a3fa4	861	{
nandgate	0:6dee052a3fa4	862	u8_t count = 0;
nandgate	0:6dee052a3fa4	863
nandgate	0:6dee052a3fa4	864	if (seg != NULL) {
nandgate	0:6dee052a3fa4	865	if (seg->p != NULL) {
nandgate	0:6dee052a3fa4	866	count = pbuf_free(seg->p);
nandgate	0:6dee052a3fa4	867	#if TCP_DEBUG
nandgate	0:6dee052a3fa4	868	seg->p = NULL;
nandgate	0:6dee052a3fa4	869	#endif /* TCP_DEBUG */
nandgate	0:6dee052a3fa4	870	}
nandgate	0:6dee052a3fa4	871	memp_free(MEMP_TCP_SEG, seg);
nandgate	0:6dee052a3fa4	872	}
nandgate	0:6dee052a3fa4	873	return count;
nandgate	0:6dee052a3fa4	874	}
nandgate	0:6dee052a3fa4	875
nandgate	0:6dee052a3fa4	876	/**
nandgate	0:6dee052a3fa4	877	* Sets the priority of a connection.
nandgate	0:6dee052a3fa4	878	*
nandgate	0:6dee052a3fa4	879	* @param pcb the tcp_pcb to manipulate
nandgate	0:6dee052a3fa4	880	* @param prio new priority
nandgate	0:6dee052a3fa4	881	*/
nandgate	0:6dee052a3fa4	882	void
nandgate	0:6dee052a3fa4	883	tcp_setprio(struct tcp_pcb *pcb, u8_t prio)
nandgate	0:6dee052a3fa4	884	{
nandgate	0:6dee052a3fa4	885	pcb->prio = prio;
nandgate	0:6dee052a3fa4	886	}
nandgate	0:6dee052a3fa4	887	#if TCP_QUEUE_OOSEQ
nandgate	0:6dee052a3fa4	888
nandgate	0:6dee052a3fa4	889	/**
nandgate	0:6dee052a3fa4	890	* Returns a copy of the given TCP segment.
nandgate	0:6dee052a3fa4	891	* The pbuf and data are not copied, only the pointers
nandgate	0:6dee052a3fa4	892	*
nandgate	0:6dee052a3fa4	893	* @param seg the old tcp_seg
nandgate	0:6dee052a3fa4	894	* @return a copy of seg
nandgate	0:6dee052a3fa4	895	*/
nandgate	0:6dee052a3fa4	896	struct tcp_seg *
nandgate	0:6dee052a3fa4	897	tcp_seg_copy(struct tcp_seg *seg)
nandgate	0:6dee052a3fa4	898	{
nandgate	0:6dee052a3fa4	899	struct tcp_seg *cseg;
nandgate	0:6dee052a3fa4	900
nandgate	0:6dee052a3fa4	901	cseg = (struct tcp_seg *)memp_malloc(MEMP_TCP_SEG);
nandgate	0:6dee052a3fa4	902	if (cseg == NULL) {
nandgate	0:6dee052a3fa4	903	return NULL;
nandgate	0:6dee052a3fa4	904	}
nandgate	0:6dee052a3fa4	905	SMEMCPY((u8_t )cseg, (const u8_t )seg, sizeof(struct tcp_seg));
nandgate	0:6dee052a3fa4	906	pbuf_ref(cseg->p);
nandgate	0:6dee052a3fa4	907	return cseg;
nandgate	0:6dee052a3fa4	908	}
nandgate	0:6dee052a3fa4	909	#endif
nandgate	0:6dee052a3fa4	910
nandgate	0:6dee052a3fa4	911	#if LWIP_CALLBACK_API
nandgate	0:6dee052a3fa4	912	/**
nandgate	0:6dee052a3fa4	913	* Default receive callback that is called if the user didn't register
nandgate	0:6dee052a3fa4	914	* a recv callback for the pcb.
nandgate	0:6dee052a3fa4	915	*/
nandgate	0:6dee052a3fa4	916	static err_t
nandgate	0:6dee052a3fa4	917	tcp_recv_null(void arg, struct tcp_pcb pcb, struct pbuf *p, err_t err)
nandgate	0:6dee052a3fa4	918	{
nandgate	0:6dee052a3fa4	919	arg = arg;
nandgate	0:6dee052a3fa4	920	if (p != NULL) {
nandgate	0:6dee052a3fa4	921	pbuf_free(p);
nandgate	0:6dee052a3fa4	922	} else if (err == ERR_OK) {
nandgate	0:6dee052a3fa4	923	return tcp_close(pcb);
nandgate	0:6dee052a3fa4	924	}
nandgate	0:6dee052a3fa4	925	return ERR_OK;
nandgate	0:6dee052a3fa4	926	}
nandgate	0:6dee052a3fa4	927	#endif /* LWIP_CALLBACK_API */
nandgate	0:6dee052a3fa4	928
nandgate	0:6dee052a3fa4	929	/**
nandgate	0:6dee052a3fa4	930	* Kills the oldest active connection that has lower priority than prio.
nandgate	0:6dee052a3fa4	931	*
nandgate	0:6dee052a3fa4	932	* @param prio minimum priority
nandgate	0:6dee052a3fa4	933	*/
nandgate	0:6dee052a3fa4	934	static void
nandgate	0:6dee052a3fa4	935	tcp_kill_prio(u8_t prio)
nandgate	0:6dee052a3fa4	936	{
nandgate	0:6dee052a3fa4	937	struct tcp_pcb pcb, inactive;
nandgate	0:6dee052a3fa4	938	u32_t inactivity;
nandgate	0:6dee052a3fa4	939	u8_t mprio;
nandgate	0:6dee052a3fa4	940
nandgate	0:6dee052a3fa4	941
nandgate	0:6dee052a3fa4	942	mprio = TCP_PRIO_MAX;
nandgate	0:6dee052a3fa4	943
nandgate	0:6dee052a3fa4	944	/* We kill the oldest active connection that has lower priority than prio. */
nandgate	0:6dee052a3fa4	945	inactivity = 0;
nandgate	0:6dee052a3fa4	946	inactive = NULL;
nandgate	0:6dee052a3fa4	947	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
nandgate	0:6dee052a3fa4	948	if (pcb->prio <= prio &&
nandgate	0:6dee052a3fa4	949	pcb->prio <= mprio &&
nandgate	0:6dee052a3fa4	950	(u32_t)(tcp_ticks - pcb->tmr) >= inactivity) {
nandgate	0:6dee052a3fa4	951	inactivity = tcp_ticks - pcb->tmr;
nandgate	0:6dee052a3fa4	952	inactive = pcb;
nandgate	0:6dee052a3fa4	953	mprio = pcb->prio;
nandgate	0:6dee052a3fa4	954	}
nandgate	0:6dee052a3fa4	955	}
nandgate	0:6dee052a3fa4	956	if (inactive != NULL) {
nandgate	0:6dee052a3fa4	957	LWIP_DEBUGF(TCP_DEBUG, ("tcp_kill_prio: killing oldest PCB %p (%"S32_F")\n",
nandgate	0:6dee052a3fa4	958	(void *)inactive, inactivity));
nandgate	0:6dee052a3fa4	959	tcp_abort(inactive);
nandgate	0:6dee052a3fa4	960	}
nandgate	0:6dee052a3fa4	961	}
nandgate	0:6dee052a3fa4	962
nandgate	0:6dee052a3fa4	963	/**
nandgate	0:6dee052a3fa4	964	* Kills the oldest connection that is in TIME_WAIT state.
nandgate	0:6dee052a3fa4	965	* Called from tcp_alloc() if no more connections are available.
nandgate	0:6dee052a3fa4	966	*/
nandgate	0:6dee052a3fa4	967	static void
nandgate	0:6dee052a3fa4	968	tcp_kill_timewait(void)
nandgate	0:6dee052a3fa4	969	{
nandgate	0:6dee052a3fa4	970	struct tcp_pcb pcb, inactive;
nandgate	0:6dee052a3fa4	971	u32_t inactivity;
nandgate	0:6dee052a3fa4	972
nandgate	0:6dee052a3fa4	973	inactivity = 0;
nandgate	0:6dee052a3fa4	974	inactive = NULL;
nandgate	0:6dee052a3fa4	975	/* Go through the list of TIME_WAIT pcbs and get the oldest pcb. */
nandgate	0:6dee052a3fa4	976	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
nandgate	0:6dee052a3fa4	977	if ((u32_t)(tcp_ticks - pcb->tmr) >= inactivity) {
nandgate	0:6dee052a3fa4	978	inactivity = tcp_ticks - pcb->tmr;
nandgate	0:6dee052a3fa4	979	inactive = pcb;
nandgate	0:6dee052a3fa4	980	}
nandgate	0:6dee052a3fa4	981	}
nandgate	0:6dee052a3fa4	982	if (inactive != NULL) {
nandgate	0:6dee052a3fa4	983	LWIP_DEBUGF(TCP_DEBUG, ("tcp_kill_timewait: killing oldest TIME-WAIT PCB %p (%"S32_F")\n",
nandgate	0:6dee052a3fa4	984	(void *)inactive, inactivity));
nandgate	0:6dee052a3fa4	985	tcp_abort(inactive);
nandgate	0:6dee052a3fa4	986	}
nandgate	0:6dee052a3fa4	987	}
nandgate	0:6dee052a3fa4	988
nandgate	0:6dee052a3fa4	989	/**
nandgate	0:6dee052a3fa4	990	* Allocate a new tcp_pcb structure.
nandgate	0:6dee052a3fa4	991	*
nandgate	0:6dee052a3fa4	992	* @param prio priority for the new pcb
nandgate	0:6dee052a3fa4	993	* @return a new tcp_pcb that initially is in state CLOSED
nandgate	0:6dee052a3fa4	994	*/
nandgate	0:6dee052a3fa4	995	struct tcp_pcb *
nandgate	0:6dee052a3fa4	996	tcp_alloc(u8_t prio)
nandgate	0:6dee052a3fa4	997	{
nandgate	0:6dee052a3fa4	998	struct tcp_pcb *pcb;
nandgate	0:6dee052a3fa4	999	u32_t iss;
nandgate	0:6dee052a3fa4	1000
nandgate	0:6dee052a3fa4	1001	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
nandgate	0:6dee052a3fa4	1002	if (pcb == NULL) {
nandgate	0:6dee052a3fa4	1003	/* Try killing oldest connection in TIME-WAIT. */
nandgate	0:6dee052a3fa4	1004	LWIP_DEBUGF(TCP_DEBUG, ("tcp_alloc: killing off oldest TIME-WAIT connection\n"));
nandgate	0:6dee052a3fa4	1005	tcp_kill_timewait();
nandgate	0:6dee052a3fa4	1006	/* Try to allocate a tcp_pcb again. */
nandgate	0:6dee052a3fa4	1007	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
nandgate	0:6dee052a3fa4	1008	if (pcb == NULL) {
nandgate	0:6dee052a3fa4	1009	/* Try killing active connections with lower priority than the new one. */
nandgate	0:6dee052a3fa4	1010	tcp_kill_prio(prio);
nandgate	0:6dee052a3fa4	1011	/* Try to allocate a tcp_pcb again. */
nandgate	0:6dee052a3fa4	1012	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
nandgate	0:6dee052a3fa4	1013	}
nandgate	0:6dee052a3fa4	1014	}
nandgate	0:6dee052a3fa4	1015	if (pcb != NULL) {
nandgate	0:6dee052a3fa4	1016	memset(pcb, 0, sizeof(struct tcp_pcb));
nandgate	0:6dee052a3fa4	1017	pcb->prio = TCP_PRIO_NORMAL;
nandgate	0:6dee052a3fa4	1018	pcb->snd_buf = TCP_SND_BUF;
nandgate	0:6dee052a3fa4	1019	pcb->snd_queuelen = 0;
nandgate	0:6dee052a3fa4	1020	pcb->rcv_wnd = TCP_WND;
nandgate	0:6dee052a3fa4	1021	pcb->rcv_ann_wnd = TCP_WND;
nandgate	0:6dee052a3fa4	1022	pcb->tos = 0;
nandgate	0:6dee052a3fa4	1023	pcb->ttl = TCP_TTL;
nandgate	0:6dee052a3fa4	1024	/* As initial send MSS, we use TCP_MSS but limit it to 536.
nandgate	0:6dee052a3fa4	1025	The send MSS is updated when an MSS option is received. */
nandgate	0:6dee052a3fa4	1026	pcb->mss = (TCP_MSS > 536) ? 536 : TCP_MSS;
nandgate	0:6dee052a3fa4	1027	pcb->rto = 3000 / TCP_SLOW_INTERVAL;
nandgate	0:6dee052a3fa4	1028	pcb->sa = 0;
nandgate	0:6dee052a3fa4	1029	pcb->sv = 3000 / TCP_SLOW_INTERVAL;
nandgate	0:6dee052a3fa4	1030	pcb->rtime = -1;
nandgate	0:6dee052a3fa4	1031	pcb->cwnd = 1;
nandgate	0:6dee052a3fa4	1032	iss = tcp_next_iss();
nandgate	0:6dee052a3fa4	1033	pcb->snd_wl2 = iss;
nandgate	0:6dee052a3fa4	1034	pcb->snd_nxt = iss;
nandgate	0:6dee052a3fa4	1035	pcb->lastack = iss;
nandgate	0:6dee052a3fa4	1036	pcb->snd_lbb = iss;
nandgate	0:6dee052a3fa4	1037	pcb->tmr = tcp_ticks;
nandgate	0:6dee052a3fa4	1038
nandgate	0:6dee052a3fa4	1039	pcb->polltmr = 0;
nandgate	0:6dee052a3fa4	1040
nandgate	0:6dee052a3fa4	1041	#if LWIP_CALLBACK_API
nandgate	0:6dee052a3fa4	1042	pcb->recv = tcp_recv_null;
nandgate	0:6dee052a3fa4	1043	#endif /* LWIP_CALLBACK_API */
nandgate	0:6dee052a3fa4	1044
nandgate	0:6dee052a3fa4	1045	/* Init KEEPALIVE timer */
nandgate	0:6dee052a3fa4	1046	pcb->keep_idle = TCP_KEEPIDLE_DEFAULT;
nandgate	0:6dee052a3fa4	1047
nandgate	0:6dee052a3fa4	1048	#if LWIP_TCP_KEEPALIVE
nandgate	0:6dee052a3fa4	1049	pcb->keep_intvl = TCP_KEEPINTVL_DEFAULT;
nandgate	0:6dee052a3fa4	1050	pcb->keep_cnt = TCP_KEEPCNT_DEFAULT;
nandgate	0:6dee052a3fa4	1051	#endif /* LWIP_TCP_KEEPALIVE */
nandgate	0:6dee052a3fa4	1052
nandgate	0:6dee052a3fa4	1053	pcb->keep_cnt_sent = 0;
nandgate	0:6dee052a3fa4	1054	}
nandgate	0:6dee052a3fa4	1055	return pcb;
nandgate	0:6dee052a3fa4	1056	}
nandgate	0:6dee052a3fa4	1057
nandgate	0:6dee052a3fa4	1058	/**
nandgate	0:6dee052a3fa4	1059	* Creates a new TCP protocol control block but doesn't place it on
nandgate	0:6dee052a3fa4	1060	* any of the TCP PCB lists.
nandgate	0:6dee052a3fa4	1061	* The pcb is not put on any list until binding using tcp_bind().
nandgate	0:6dee052a3fa4	1062	*
nandgate	0:6dee052a3fa4	1063	* @internal: Maybe there should be a idle TCP PCB list where these
nandgate	0:6dee052a3fa4	1064	* PCBs are put on. Port reservation using tcp_bind() is implemented but
nandgate	0:6dee052a3fa4	1065	* allocated pcbs that are not bound can't be killed automatically if wanting
nandgate	0:6dee052a3fa4	1066	* to allocate a pcb with higher prio (@see tcp_kill_prio())
nandgate	0:6dee052a3fa4	1067	*
nandgate	0:6dee052a3fa4	1068	* @return a new tcp_pcb that initially is in state CLOSED
nandgate	0:6dee052a3fa4	1069	*/
nandgate	0:6dee052a3fa4	1070	struct tcp_pcb *
nandgate	0:6dee052a3fa4	1071	tcp_new(void)
nandgate	0:6dee052a3fa4	1072	{
nandgate	0:6dee052a3fa4	1073	return tcp_alloc(TCP_PRIO_NORMAL);
nandgate	0:6dee052a3fa4	1074	}
nandgate	0:6dee052a3fa4	1075
nandgate	0:6dee052a3fa4	1076	/**
nandgate	0:6dee052a3fa4	1077	* Used to specify the argument that should be passed callback
nandgate	0:6dee052a3fa4	1078	* functions.
nandgate	0:6dee052a3fa4	1079	*
nandgate	0:6dee052a3fa4	1080	* @param pcb tcp_pcb to set the callback argument
nandgate	0:6dee052a3fa4	1081	* @param arg void pointer argument to pass to callback functions
nandgate	0:6dee052a3fa4	1082	*/
nandgate	0:6dee052a3fa4	1083	void
nandgate	0:6dee052a3fa4	1084	tcp_arg(struct tcp_pcb pcb, void arg)
nandgate	0:6dee052a3fa4	1085	{
nandgate	0:6dee052a3fa4	1086	pcb->callback_arg = arg;
nandgate	0:6dee052a3fa4	1087	}
nandgate	0:6dee052a3fa4	1088	#if LWIP_CALLBACK_API
nandgate	0:6dee052a3fa4	1089
nandgate	0:6dee052a3fa4	1090	/**
nandgate	0:6dee052a3fa4	1091	* Used to specify the function that should be called when a TCP
nandgate	0:6dee052a3fa4	1092	* connection receives data.
nandgate	0:6dee052a3fa4	1093	*
nandgate	0:6dee052a3fa4	1094	* @param pcb tcp_pcb to set the recv callback
nandgate	0:6dee052a3fa4	1095	* @param recv callback function to call for this pcb when data is received
nandgate	0:6dee052a3fa4	1096	*/
nandgate	0:6dee052a3fa4	1097	void
nandgate	0:6dee052a3fa4	1098	tcp_recv(struct tcp_pcb *pcb,
nandgate	0:6dee052a3fa4	1099	err_t (* recv)(void arg, struct tcp_pcb tpcb, struct pbuf *p, err_t err))
nandgate	0:6dee052a3fa4	1100	{
nandgate	0:6dee052a3fa4	1101	pcb->recv = recv;
nandgate	0:6dee052a3fa4	1102	}
nandgate	0:6dee052a3fa4	1103
nandgate	0:6dee052a3fa4	1104	/**
nandgate	0:6dee052a3fa4	1105	* Used to specify the function that should be called when TCP data
nandgate	0:6dee052a3fa4	1106	* has been successfully delivered to the remote host.
nandgate	0:6dee052a3fa4	1107	*
nandgate	0:6dee052a3fa4	1108	* @param pcb tcp_pcb to set the sent callback
nandgate	0:6dee052a3fa4	1109	* @param sent callback function to call for this pcb when data is successfully sent
nandgate	0:6dee052a3fa4	1110	*/
nandgate	0:6dee052a3fa4	1111	void
nandgate	0:6dee052a3fa4	1112	tcp_sent(struct tcp_pcb *pcb,
nandgate	0:6dee052a3fa4	1113	err_t (* sent)(void arg, struct tcp_pcb tpcb, u16_t len))
nandgate	0:6dee052a3fa4	1114	{
nandgate	0:6dee052a3fa4	1115	pcb->sent = sent;
nandgate	0:6dee052a3fa4	1116	}
nandgate	0:6dee052a3fa4	1117
nandgate	0:6dee052a3fa4	1118	/**
nandgate	0:6dee052a3fa4	1119	* Used to specify the function that should be called when a fatal error
nandgate	0:6dee052a3fa4	1120	* has occured on the connection.
nandgate	0:6dee052a3fa4	1121	*
nandgate	0:6dee052a3fa4	1122	* @param pcb tcp_pcb to set the err callback
nandgate	0:6dee052a3fa4	1123	* @param errf callback function to call for this pcb when a fatal error
nandgate	0:6dee052a3fa4	1124	* has occured on the connection
nandgate	0:6dee052a3fa4	1125	*/
nandgate	0:6dee052a3fa4	1126	void
nandgate	0:6dee052a3fa4	1127	tcp_err(struct tcp_pcb *pcb,
nandgate	0:6dee052a3fa4	1128	void (* errf)(void *arg, err_t err))
nandgate	0:6dee052a3fa4	1129	{
nandgate	0:6dee052a3fa4	1130	pcb->errf = errf;
nandgate	0:6dee052a3fa4	1131	}
nandgate	0:6dee052a3fa4	1132
nandgate	0:6dee052a3fa4	1133	/**
nandgate	0:6dee052a3fa4	1134	* Used for specifying the function that should be called when a
nandgate	0:6dee052a3fa4	1135	* LISTENing connection has been connected to another host.
nandgate	0:6dee052a3fa4	1136	*
nandgate	0:6dee052a3fa4	1137	* @param pcb tcp_pcb to set the accept callback
nandgate	0:6dee052a3fa4	1138	* @param accept callback function to call for this pcb when LISTENing
nandgate	0:6dee052a3fa4	1139	* connection has been connected to another host
nandgate	0:6dee052a3fa4	1140	*/
nandgate	0:6dee052a3fa4	1141	void
nandgate	0:6dee052a3fa4	1142	tcp_accept(struct tcp_pcb *pcb,
nandgate	0:6dee052a3fa4	1143	err_t (* accept)(void arg, struct tcp_pcb newpcb, err_t err))
nandgate	0:6dee052a3fa4	1144	{
nandgate	0:6dee052a3fa4	1145	pcb->accept = accept;
nandgate	0:6dee052a3fa4	1146	}
nandgate	0:6dee052a3fa4	1147	#endif /* LWIP_CALLBACK_API */
nandgate	0:6dee052a3fa4	1148
nandgate	0:6dee052a3fa4	1149
nandgate	0:6dee052a3fa4	1150	/**
nandgate	0:6dee052a3fa4	1151	* Used to specify the function that should be called periodically
nandgate	0:6dee052a3fa4	1152	* from TCP. The interval is specified in terms of the TCP coarse
nandgate	0:6dee052a3fa4	1153	* timer interval, which is called twice a second.
nandgate	0:6dee052a3fa4	1154	*
nandgate	0:6dee052a3fa4	1155	*/
nandgate	0:6dee052a3fa4	1156	void
nandgate	0:6dee052a3fa4	1157	tcp_poll(struct tcp_pcb *pcb,
nandgate	0:6dee052a3fa4	1158	err_t (* poll)(void arg, struct tcp_pcb tpcb), u8_t interval)
nandgate	0:6dee052a3fa4	1159	{
nandgate	0:6dee052a3fa4	1160	#if LWIP_CALLBACK_API
nandgate	0:6dee052a3fa4	1161	pcb->poll = poll;
nandgate	0:6dee052a3fa4	1162	#endif /* LWIP_CALLBACK_API */
nandgate	0:6dee052a3fa4	1163	pcb->pollinterval = interval;
nandgate	0:6dee052a3fa4	1164	}
nandgate	0:6dee052a3fa4	1165
nandgate	0:6dee052a3fa4	1166	/**
nandgate	0:6dee052a3fa4	1167	* Purges a TCP PCB. Removes any buffered data and frees the buffer memory
nandgate	0:6dee052a3fa4	1168	* (pcb->ooseq, pcb->unsent and pcb->unacked are freed).
nandgate	0:6dee052a3fa4	1169	*
nandgate	0:6dee052a3fa4	1170	* @param pcb tcp_pcb to purge. The pcb itself is not deallocated!
nandgate	0:6dee052a3fa4	1171	*/
nandgate	0:6dee052a3fa4	1172	void
nandgate	0:6dee052a3fa4	1173	tcp_pcb_purge(struct tcp_pcb *pcb)
nandgate	0:6dee052a3fa4	1174	{
nandgate	0:6dee052a3fa4	1175	if (pcb->state != CLOSED &&
nandgate	0:6dee052a3fa4	1176	pcb->state != TIME_WAIT &&
nandgate	0:6dee052a3fa4	1177	pcb->state != LISTEN) {
nandgate	0:6dee052a3fa4	1178
nandgate	0:6dee052a3fa4	1179	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge\n"));
nandgate	0:6dee052a3fa4	1180
nandgate	0:6dee052a3fa4	1181	#if TCP_LISTEN_BACKLOG
nandgate	0:6dee052a3fa4	1182	if (pcb->state == SYN_RCVD) {
nandgate	0:6dee052a3fa4	1183	/* Need to find the corresponding listen_pcb and decrease its accepts_pending */
nandgate	0:6dee052a3fa4	1184	struct tcp_pcb_listen *lpcb;
nandgate	0:6dee052a3fa4	1185	LWIP_ASSERT("tcp_pcb_purge: pcb->state == SYN_RCVD but tcp_listen_pcbs is NULL",
nandgate	0:6dee052a3fa4	1186	tcp_listen_pcbs.listen_pcbs != NULL);
nandgate	0:6dee052a3fa4	1187	for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
nandgate	0:6dee052a3fa4	1188	if ((lpcb->local_port == pcb->local_port) &&
nandgate	0:6dee052a3fa4	1189	(ip_addr_isany(&lpcb->local_ip) \|\|
nandgate	0:6dee052a3fa4	1190	ip_addr_cmp(&pcb->local_ip, &lpcb->local_ip))) {
nandgate	0:6dee052a3fa4	1191	/* port and address of the listen pcb match the timed-out pcb */
nandgate	0:6dee052a3fa4	1192	LWIP_ASSERT("tcp_pcb_purge: listen pcb does not have accepts pending",
nandgate	0:6dee052a3fa4	1193	lpcb->accepts_pending > 0);
nandgate	0:6dee052a3fa4	1194	lpcb->accepts_pending--;
nandgate	0:6dee052a3fa4	1195	break;
nandgate	0:6dee052a3fa4	1196	}
nandgate	0:6dee052a3fa4	1197	}
nandgate	0:6dee052a3fa4	1198	}
nandgate	0:6dee052a3fa4	1199	#endif /* TCP_LISTEN_BACKLOG */
nandgate	0:6dee052a3fa4	1200
nandgate	0:6dee052a3fa4	1201
nandgate	0:6dee052a3fa4	1202	if (pcb->refused_data != NULL) {
nandgate	0:6dee052a3fa4	1203	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->refused_data\n"));
nandgate	0:6dee052a3fa4	1204	pbuf_free(pcb->refused_data);
nandgate	0:6dee052a3fa4	1205	pcb->refused_data = NULL;
nandgate	0:6dee052a3fa4	1206	}
nandgate	0:6dee052a3fa4	1207	if (pcb->unsent != NULL) {
nandgate	0:6dee052a3fa4	1208	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: not all data sent\n"));
nandgate	0:6dee052a3fa4	1209	}
nandgate	0:6dee052a3fa4	1210	if (pcb->unacked != NULL) {
nandgate	0:6dee052a3fa4	1211	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->unacked\n"));
nandgate	0:6dee052a3fa4	1212	}
nandgate	0:6dee052a3fa4	1213	#if TCP_QUEUE_OOSEQ /* LW */
nandgate	0:6dee052a3fa4	1214	if (pcb->ooseq != NULL) {
nandgate	0:6dee052a3fa4	1215	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->ooseq\n"));
nandgate	0:6dee052a3fa4	1216	}
nandgate	0:6dee052a3fa4	1217
nandgate	0:6dee052a3fa4	1218	/* Stop the retransmission timer as it will expect data on unacked
nandgate	0:6dee052a3fa4	1219	queue if it fires */
nandgate	0:6dee052a3fa4	1220	pcb->rtime = -1;
nandgate	0:6dee052a3fa4	1221
nandgate	0:6dee052a3fa4	1222	tcp_segs_free(pcb->ooseq);
nandgate	0:6dee052a3fa4	1223	pcb->ooseq = NULL;
nandgate	0:6dee052a3fa4	1224	#endif /* TCP_QUEUE_OOSEQ */
nandgate	0:6dee052a3fa4	1225	tcp_segs_free(pcb->unsent);
nandgate	0:6dee052a3fa4	1226	tcp_segs_free(pcb->unacked);
nandgate	0:6dee052a3fa4	1227	pcb->unacked = pcb->unsent = NULL;
nandgate	0:6dee052a3fa4	1228	}
nandgate	0:6dee052a3fa4	1229	}
nandgate	0:6dee052a3fa4	1230
nandgate	0:6dee052a3fa4	1231	/**
nandgate	0:6dee052a3fa4	1232	* Purges the PCB and removes it from a PCB list. Any delayed ACKs are sent first.
nandgate	0:6dee052a3fa4	1233	*
nandgate	0:6dee052a3fa4	1234	* @param pcblist PCB list to purge.
nandgate	0:6dee052a3fa4	1235	* @param pcb tcp_pcb to purge. The pcb itself is also deallocated!
nandgate	0:6dee052a3fa4	1236	*/
nandgate	0:6dee052a3fa4	1237	void
nandgate	0:6dee052a3fa4	1238	tcp_pcb_remove(struct tcp_pcb *pcblist, struct tcp_pcb pcb)
nandgate	0:6dee052a3fa4	1239	{
nandgate	0:6dee052a3fa4	1240	TCP_RMV(pcblist, pcb);
nandgate	0:6dee052a3fa4	1241
nandgate	0:6dee052a3fa4	1242	tcp_pcb_purge(pcb);
nandgate	0:6dee052a3fa4	1243
nandgate	0:6dee052a3fa4	1244	/* if there is an outstanding delayed ACKs, send it */
nandgate	0:6dee052a3fa4	1245	if (pcb->state != TIME_WAIT &&
nandgate	0:6dee052a3fa4	1246	pcb->state != LISTEN &&
nandgate	0:6dee052a3fa4	1247	pcb->flags & TF_ACK_DELAY) {
nandgate	0:6dee052a3fa4	1248	pcb->flags \|= TF_ACK_NOW;
nandgate	0:6dee052a3fa4	1249	tcp_output(pcb);
nandgate	0:6dee052a3fa4	1250	}
nandgate	0:6dee052a3fa4	1251
nandgate	0:6dee052a3fa4	1252	if (pcb->state != LISTEN) {
nandgate	0:6dee052a3fa4	1253	LWIP_ASSERT("unsent segments leaking", pcb->unsent == NULL);
nandgate	0:6dee052a3fa4	1254	LWIP_ASSERT("unacked segments leaking", pcb->unacked == NULL);
nandgate	0:6dee052a3fa4	1255	#if TCP_QUEUE_OOSEQ
nandgate	0:6dee052a3fa4	1256	LWIP_ASSERT("ooseq segments leaking", pcb->ooseq == NULL);
nandgate	0:6dee052a3fa4	1257	#endif /* TCP_QUEUE_OOSEQ */
nandgate	0:6dee052a3fa4	1258	}
nandgate	0:6dee052a3fa4	1259
nandgate	0:6dee052a3fa4	1260	pcb->state = CLOSED;
nandgate	0:6dee052a3fa4	1261
nandgate	0:6dee052a3fa4	1262	LWIP_ASSERT("tcp_pcb_remove: tcp_pcbs_sane()", tcp_pcbs_sane());
nandgate	0:6dee052a3fa4	1263	}
nandgate	0:6dee052a3fa4	1264
nandgate	0:6dee052a3fa4	1265	/**
nandgate	0:6dee052a3fa4	1266	* Calculates a new initial sequence number for new connections.
nandgate	0:6dee052a3fa4	1267	*
nandgate	0:6dee052a3fa4	1268	* @return u32_t pseudo random sequence number
nandgate	0:6dee052a3fa4	1269	*/
nandgate	0:6dee052a3fa4	1270	u32_t
nandgate	0:6dee052a3fa4	1271	tcp_next_iss(void)
nandgate	0:6dee052a3fa4	1272	{
nandgate	0:6dee052a3fa4	1273	static u32_t iss = 6510;
nandgate	0:6dee052a3fa4	1274
nandgate	0:6dee052a3fa4	1275	iss += tcp_ticks; /* XXX */
nandgate	0:6dee052a3fa4	1276	return iss;
nandgate	0:6dee052a3fa4	1277	}
nandgate	0:6dee052a3fa4	1278
nandgate	0:6dee052a3fa4	1279	#if TCP_CALCULATE_EFF_SEND_MSS
nandgate	0:6dee052a3fa4	1280	/**
nandgate	0:6dee052a3fa4	1281	* Calcluates the effective send mss that can be used for a specific IP address
nandgate	0:6dee052a3fa4	1282	* by using ip_route to determin the netif used to send to the address and
nandgate	0:6dee052a3fa4	1283	* calculating the minimum of TCP_MSS and that netif's mtu (if set).
nandgate	0:6dee052a3fa4	1284	*/
nandgate	0:6dee052a3fa4	1285	u16_t
nandgate	0:6dee052a3fa4	1286	tcp_eff_send_mss(u16_t sendmss, struct ip_addr *addr)
nandgate	0:6dee052a3fa4	1287	{
nandgate	0:6dee052a3fa4	1288	u16_t mss_s;
nandgate	0:6dee052a3fa4	1289	struct netif *outif;
nandgate	0:6dee052a3fa4	1290
nandgate	0:6dee052a3fa4	1291	outif = ip_route(addr);
nandgate	0:6dee052a3fa4	1292	if ((outif != NULL) && (outif->mtu != 0)) {
nandgate	0:6dee052a3fa4	1293	mss_s = outif->mtu - IP_HLEN - TCP_HLEN;
nandgate	0:6dee052a3fa4	1294	/* RFC 1122, chap 4.2.2.6:
nandgate	0:6dee052a3fa4	1295	* Eff.snd.MSS = min(SendMSS+20, MMS_S) - TCPhdrsize - IPoptionsize
nandgate	0:6dee052a3fa4	1296	* We correct for TCP options in tcp_enqueue(), and don't support
nandgate	0:6dee052a3fa4	1297	* IP options
nandgate	0:6dee052a3fa4	1298	*/
nandgate	0:6dee052a3fa4	1299	sendmss = LWIP_MIN(sendmss, mss_s);
nandgate	0:6dee052a3fa4	1300	}
nandgate	0:6dee052a3fa4	1301	return sendmss;
nandgate	0:6dee052a3fa4	1302	}
nandgate	0:6dee052a3fa4	1303	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
nandgate	0:6dee052a3fa4	1304
nandgate	0:6dee052a3fa4	1305	const char*
nandgate	0:6dee052a3fa4	1306	tcp_debug_state_str(enum tcp_state s)
nandgate	0:6dee052a3fa4	1307	{
nandgate	0:6dee052a3fa4	1308	return tcp_state_str[s];
nandgate	0:6dee052a3fa4	1309	}
nandgate	0:6dee052a3fa4	1310
nandgate	0:6dee052a3fa4	1311	#if TCP_DEBUG \|\| TCP_INPUT_DEBUG \|\| TCP_OUTPUT_DEBUG
nandgate	0:6dee052a3fa4	1312	/**
nandgate	0:6dee052a3fa4	1313	* Print a tcp header for debugging purposes.
nandgate	0:6dee052a3fa4	1314	*
nandgate	0:6dee052a3fa4	1315	* @param tcphdr pointer to a struct tcp_hdr
nandgate	0:6dee052a3fa4	1316	*/
nandgate	0:6dee052a3fa4	1317	void
nandgate	0:6dee052a3fa4	1318	tcp_debug_print(struct tcp_hdr *tcphdr)
nandgate	0:6dee052a3fa4	1319	{
nandgate	0:6dee052a3fa4	1320	LWIP_DEBUGF(TCP_DEBUG, ("TCP header:\n"));
nandgate	0:6dee052a3fa4	1321	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
nandgate	0:6dee052a3fa4	1322	LWIP_DEBUGF(TCP_DEBUG, ("\| %5"U16_F" \| %5"U16_F" \| (src port, dest port)\n",
nandgate	0:6dee052a3fa4	1323	ntohs(tcphdr->src), ntohs(tcphdr->dest)));
nandgate	0:6dee052a3fa4	1324	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
nandgate	0:6dee052a3fa4	1325	LWIP_DEBUGF(TCP_DEBUG, ("\| %010"U32_F" \| (seq no)\n",
nandgate	0:6dee052a3fa4	1326	ntohl(tcphdr->seqno)));
nandgate	0:6dee052a3fa4	1327	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
nandgate	0:6dee052a3fa4	1328	LWIP_DEBUGF(TCP_DEBUG, ("\| %010"U32_F" \| (ack no)\n",
nandgate	0:6dee052a3fa4	1329	ntohl(tcphdr->ackno)));
nandgate	0:6dee052a3fa4	1330	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
nandgate	0:6dee052a3fa4	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 (",
nandgate	0:6dee052a3fa4	1332	TCPH_HDRLEN(tcphdr),
nandgate	0:6dee052a3fa4	1333	TCPH_FLAGS(tcphdr) >> 5 & 1,
nandgate	0:6dee052a3fa4	1334	TCPH_FLAGS(tcphdr) >> 4 & 1,
nandgate	0:6dee052a3fa4	1335	TCPH_FLAGS(tcphdr) >> 3 & 1,
nandgate	0:6dee052a3fa4	1336	TCPH_FLAGS(tcphdr) >> 2 & 1,
nandgate	0:6dee052a3fa4	1337	TCPH_FLAGS(tcphdr) >> 1 & 1,
nandgate	0:6dee052a3fa4	1338	TCPH_FLAGS(tcphdr) & 1,
nandgate	0:6dee052a3fa4	1339	ntohs(tcphdr->wnd)));
nandgate	0:6dee052a3fa4	1340	tcp_debug_print_flags(TCPH_FLAGS(tcphdr));
nandgate	0:6dee052a3fa4	1341	LWIP_DEBUGF(TCP_DEBUG, ("), win)\n"));
nandgate	0:6dee052a3fa4	1342	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
nandgate	0:6dee052a3fa4	1343	LWIP_DEBUGF(TCP_DEBUG, ("\| 0x%04"X16_F" \| %5"U16_F" \| (chksum, urgp)\n",
nandgate	0:6dee052a3fa4	1344	ntohs(tcphdr->chksum), ntohs(tcphdr->urgp)));
nandgate	0:6dee052a3fa4	1345	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
nandgate	0:6dee052a3fa4	1346	}
nandgate	0:6dee052a3fa4	1347
nandgate	0:6dee052a3fa4	1348	/**
nandgate	0:6dee052a3fa4	1349	* Print a tcp state for debugging purposes.
nandgate	0:6dee052a3fa4	1350	*
nandgate	0:6dee052a3fa4	1351	* @param s enum tcp_state to print
nandgate	0:6dee052a3fa4	1352	*/
nandgate	0:6dee052a3fa4	1353	void
nandgate	0:6dee052a3fa4	1354	tcp_debug_print_state(enum tcp_state s)
nandgate	0:6dee052a3fa4	1355	{
nandgate	0:6dee052a3fa4	1356	LWIP_DEBUGF(TCP_DEBUG, ("State: %s\n", tcp_state_str[s]));
nandgate	0:6dee052a3fa4	1357	}
nandgate	0:6dee052a3fa4	1358
nandgate	0:6dee052a3fa4	1359	/**
nandgate	0:6dee052a3fa4	1360	* Print tcp flags for debugging purposes.
nandgate	0:6dee052a3fa4	1361	*
nandgate	0:6dee052a3fa4	1362	* @param flags tcp flags, all active flags are printed
nandgate	0:6dee052a3fa4	1363	*/
nandgate	0:6dee052a3fa4	1364	void
nandgate	0:6dee052a3fa4	1365	tcp_debug_print_flags(u8_t flags)
nandgate	0:6dee052a3fa4	1366	{
nandgate	0:6dee052a3fa4	1367	if (flags & TCP_FIN) {
nandgate	0:6dee052a3fa4	1368	LWIP_DEBUGF(TCP_DEBUG, ("FIN "));
nandgate	0:6dee052a3fa4	1369	}
nandgate	0:6dee052a3fa4	1370	if (flags & TCP_SYN) {
nandgate	0:6dee052a3fa4	1371	LWIP_DEBUGF(TCP_DEBUG, ("SYN "));
nandgate	0:6dee052a3fa4	1372	}
nandgate	0:6dee052a3fa4	1373	if (flags & TCP_RST) {
nandgate	0:6dee052a3fa4	1374	LWIP_DEBUGF(TCP_DEBUG, ("RST "));
nandgate	0:6dee052a3fa4	1375	}
nandgate	0:6dee052a3fa4	1376	if (flags & TCP_PSH) {
nandgate	0:6dee052a3fa4	1377	LWIP_DEBUGF(TCP_DEBUG, ("PSH "));
nandgate	0:6dee052a3fa4	1378	}
nandgate	0:6dee052a3fa4	1379	if (flags & TCP_ACK) {
nandgate	0:6dee052a3fa4	1380	LWIP_DEBUGF(TCP_DEBUG, ("ACK "));
nandgate	0:6dee052a3fa4	1381	}
nandgate	0:6dee052a3fa4	1382	if (flags & TCP_URG) {
nandgate	0:6dee052a3fa4	1383	LWIP_DEBUGF(TCP_DEBUG, ("URG "));
nandgate	0:6dee052a3fa4	1384	}
nandgate	0:6dee052a3fa4	1385	if (flags & TCP_ECE) {
nandgate	0:6dee052a3fa4	1386	LWIP_DEBUGF(TCP_DEBUG, ("ECE "));
nandgate	0:6dee052a3fa4	1387	}
nandgate	0:6dee052a3fa4	1388	if (flags & TCP_CWR) {
nandgate	0:6dee052a3fa4	1389	LWIP_DEBUGF(TCP_DEBUG, ("CWR "));
nandgate	0:6dee052a3fa4	1390	}
nandgate	0:6dee052a3fa4	1391	LWIP_DEBUGF(TCP_DEBUG, ("\n"));
nandgate	0:6dee052a3fa4	1392	}
nandgate	0:6dee052a3fa4	1393
nandgate	0:6dee052a3fa4	1394	/**
nandgate	0:6dee052a3fa4	1395	* Print all tcp_pcbs in every list for debugging purposes.
nandgate	0:6dee052a3fa4	1396	*/
nandgate	0:6dee052a3fa4	1397	void
nandgate	0:6dee052a3fa4	1398	tcp_debug_print_pcbs(void)
nandgate	0:6dee052a3fa4	1399	{
nandgate	0:6dee052a3fa4	1400	struct tcp_pcb *pcb;
nandgate	0:6dee052a3fa4	1401	LWIP_DEBUGF(TCP_DEBUG, ("Active PCB states:\n"));
nandgate	0:6dee052a3fa4	1402	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
nandgate	0:6dee052a3fa4	1403	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
nandgate	0:6dee052a3fa4	1404	pcb->local_port, pcb->remote_port,
nandgate	0:6dee052a3fa4	1405	pcb->snd_nxt, pcb->rcv_nxt));
nandgate	0:6dee052a3fa4	1406	tcp_debug_print_state(pcb->state);
nandgate	0:6dee052a3fa4	1407	}
nandgate	0:6dee052a3fa4	1408	LWIP_DEBUGF(TCP_DEBUG, ("Listen PCB states:\n"));
nandgate	0:6dee052a3fa4	1409	for(pcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs; pcb != NULL; pcb = pcb->next) {
nandgate	0:6dee052a3fa4	1410	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
nandgate	0:6dee052a3fa4	1411	pcb->local_port, pcb->remote_port,
nandgate	0:6dee052a3fa4	1412	pcb->snd_nxt, pcb->rcv_nxt));
nandgate	0:6dee052a3fa4	1413	tcp_debug_print_state(pcb->state);
nandgate	0:6dee052a3fa4	1414	}
nandgate	0:6dee052a3fa4	1415	LWIP_DEBUGF(TCP_DEBUG, ("TIME-WAIT PCB states:\n"));
nandgate	0:6dee052a3fa4	1416	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
nandgate	0:6dee052a3fa4	1417	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
nandgate	0:6dee052a3fa4	1418	pcb->local_port, pcb->remote_port,
nandgate	0:6dee052a3fa4	1419	pcb->snd_nxt, pcb->rcv_nxt));
nandgate	0:6dee052a3fa4	1420	tcp_debug_print_state(pcb->state);
nandgate	0:6dee052a3fa4	1421	}
nandgate	0:6dee052a3fa4	1422	}
nandgate	0:6dee052a3fa4	1423
nandgate	0:6dee052a3fa4	1424	/**
nandgate	0:6dee052a3fa4	1425	* Check state consistency of the tcp_pcb lists.
nandgate	0:6dee052a3fa4	1426	*/
nandgate	0:6dee052a3fa4	1427	s16_t
nandgate	0:6dee052a3fa4	1428	tcp_pcbs_sane(void)
nandgate	0:6dee052a3fa4	1429	{
nandgate	0:6dee052a3fa4	1430	struct tcp_pcb *pcb;
nandgate	0:6dee052a3fa4	1431	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
nandgate	0:6dee052a3fa4	1432	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != CLOSED", pcb->state != CLOSED);
nandgate	0:6dee052a3fa4	1433	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != LISTEN", pcb->state != LISTEN);
nandgate	0:6dee052a3fa4	1434	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT);
nandgate	0:6dee052a3fa4	1435	}
nandgate	0:6dee052a3fa4	1436	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
nandgate	0:6dee052a3fa4	1437	LWIP_ASSERT("tcp_pcbs_sane: tw pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
nandgate	0:6dee052a3fa4	1438	}
nandgate	0:6dee052a3fa4	1439	return 1;
nandgate	0:6dee052a3fa4	1440	}
nandgate	0:6dee052a3fa4	1441	#endif /* TCP_DEBUG */
nandgate	0:6dee052a3fa4	1442
nandgate	0:6dee052a3fa4	1443	#endif /* LWIP_TCP */

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	26 Jul 2011
Imports:	159
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	2
Followers:	9

Core/lwIP/core/tcp.c@0:6dee052a3fa4, 2011-07-26 (annotated)

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