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lwip/core/tcp.c@0:ac21159e27f4, 2010-07-02 (annotated)

Committer:: darran
Date:: Fri Jul 02 17:21:58 2010 +0000
Revision:: 0:ac21159e27f4

Who changed what in which revision?

User	Revision	Line number	New contents of line
darran	0:ac21159e27f4	1	/**
darran	0:ac21159e27f4	2	* @file
darran	0:ac21159e27f4	3	* Transmission Control Protocol for IP
darran	0:ac21159e27f4	4	*
darran	0:ac21159e27f4	5	* This file contains common functions for the TCP implementation, such as functinos
darran	0:ac21159e27f4	6	* for manipulating the data structures and the TCP timer functions. TCP functions
darran	0:ac21159e27f4	7	* related to input and output is found in tcp_in.c and tcp_out.c respectively.
darran	0:ac21159e27f4	8	*
darran	0:ac21159e27f4	9	*/
darran	0:ac21159e27f4	10
darran	0:ac21159e27f4	11	/*
darran	0:ac21159e27f4	12	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
darran	0:ac21159e27f4	13	* All rights reserved.
darran	0:ac21159e27f4	14	*
darran	0:ac21159e27f4	15	* Redistribution and use in source and binary forms, with or without modification,
darran	0:ac21159e27f4	16	* are permitted provided that the following conditions are met:
darran	0:ac21159e27f4	17	*
darran	0:ac21159e27f4	18	* 1. Redistributions of source code must retain the above copyright notice,
darran	0:ac21159e27f4	19	* this list of conditions and the following disclaimer.
darran	0:ac21159e27f4	20	* 2. Redistributions in binary form must reproduce the above copyright notice,
darran	0:ac21159e27f4	21	* this list of conditions and the following disclaimer in the documentation
darran	0:ac21159e27f4	22	* and/or other materials provided with the distribution.
darran	0:ac21159e27f4	23	* 3. The name of the author may not be used to endorse or promote products
darran	0:ac21159e27f4	24	* derived from this software without specific prior written permission.
darran	0:ac21159e27f4	25	*
darran	0:ac21159e27f4	26	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
darran	0:ac21159e27f4	27	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
darran	0:ac21159e27f4	28	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
darran	0:ac21159e27f4	29	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
darran	0:ac21159e27f4	30	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
darran	0:ac21159e27f4	31	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
darran	0:ac21159e27f4	32	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
darran	0:ac21159e27f4	33	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
darran	0:ac21159e27f4	34	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
darran	0:ac21159e27f4	35	* OF SUCH DAMAGE.
darran	0:ac21159e27f4	36	*
darran	0:ac21159e27f4	37	* This file is part of the lwIP TCP/IP stack.
darran	0:ac21159e27f4	38	*
darran	0:ac21159e27f4	39	* Author: Adam Dunkels <adam@sics.se>
darran	0:ac21159e27f4	40	*
darran	0:ac21159e27f4	41	*/
darran	0:ac21159e27f4	42
darran	0:ac21159e27f4	43	#include "lwip/opt.h"
darran	0:ac21159e27f4	44
darran	0:ac21159e27f4	45	#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
darran	0:ac21159e27f4	46
darran	0:ac21159e27f4	47	#include "lwip/def.h"
darran	0:ac21159e27f4	48	#include "lwip/mem.h"
darran	0:ac21159e27f4	49	#include "lwip/memp.h"
darran	0:ac21159e27f4	50	#include "lwip/snmp.h"
darran	0:ac21159e27f4	51	#include "lwip/tcp.h"
darran	0:ac21159e27f4	52	#include "lwip/tcp_impl.h"
darran	0:ac21159e27f4	53	#include "lwip/debug.h"
darran	0:ac21159e27f4	54	#include "lwip/stats.h"
darran	0:ac21159e27f4	55
darran	0:ac21159e27f4	56	#include <string.h>
darran	0:ac21159e27f4	57
darran	0:ac21159e27f4	58	const char *tcp_state_str[] = {
darran	0:ac21159e27f4	59	"CLOSED",
darran	0:ac21159e27f4	60	"LISTEN",
darran	0:ac21159e27f4	61	"SYN_SENT",
darran	0:ac21159e27f4	62	"SYN_RCVD",
darran	0:ac21159e27f4	63	"ESTABLISHED",
darran	0:ac21159e27f4	64	"FIN_WAIT_1",
darran	0:ac21159e27f4	65	"FIN_WAIT_2",
darran	0:ac21159e27f4	66	"CLOSE_WAIT",
darran	0:ac21159e27f4	67	"CLOSING",
darran	0:ac21159e27f4	68	"LAST_ACK",
darran	0:ac21159e27f4	69	"TIME_WAIT"
darran	0:ac21159e27f4	70	};
darran	0:ac21159e27f4	71
darran	0:ac21159e27f4	72	/* Incremented every coarse grained timer shot (typically every 500 ms). */
darran	0:ac21159e27f4	73	u32_t tcp_ticks;
darran	0:ac21159e27f4	74	const u8_t tcp_backoff[13] =
darran	0:ac21159e27f4	75	{ 1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7};
darran	0:ac21159e27f4	76	/* Times per slowtmr hits */
darran	0:ac21159e27f4	77	const u8_t tcp_persist_backoff[7] = { 3, 6, 12, 24, 48, 96, 120 };
darran	0:ac21159e27f4	78
darran	0:ac21159e27f4	79	/* The TCP PCB lists. */
darran	0:ac21159e27f4	80
darran	0:ac21159e27f4	81	/** List of all TCP PCBs bound but not yet (connected \|\| listening) */
darran	0:ac21159e27f4	82	struct tcp_pcb *tcp_bound_pcbs;
darran	0:ac21159e27f4	83	/** List of all TCP PCBs in LISTEN state */
darran	0:ac21159e27f4	84	union tcp_listen_pcbs_t tcp_listen_pcbs;
darran	0:ac21159e27f4	85	/** List of all TCP PCBs that are in a state in which
darran	0:ac21159e27f4	86	* they accept or send data. */
darran	0:ac21159e27f4	87	struct tcp_pcb *tcp_active_pcbs;
darran	0:ac21159e27f4	88	/** List of all TCP PCBs in TIME-WAIT state */
darran	0:ac21159e27f4	89	struct tcp_pcb *tcp_tw_pcbs;
darran	0:ac21159e27f4	90
darran	0:ac21159e27f4	91	/** Only used for temporary storage. */
darran	0:ac21159e27f4	92	struct tcp_pcb *tcp_tmp_pcb;
darran	0:ac21159e27f4	93
darran	0:ac21159e27f4	94	/** Timer counter to handle calling slow-timer from tcp_tmr() */
darran	0:ac21159e27f4	95	static u8_t tcp_timer;
darran	0:ac21159e27f4	96	static u16_t tcp_new_port(void);
darran	0:ac21159e27f4	97
darran	0:ac21159e27f4	98	/**
darran	0:ac21159e27f4	99	* Called periodically to dispatch TCP timers.
darran	0:ac21159e27f4	100	*
darran	0:ac21159e27f4	101	*/
darran	0:ac21159e27f4	102	void
darran	0:ac21159e27f4	103	tcp_tmr(void)
darran	0:ac21159e27f4	104	{
darran	0:ac21159e27f4	105	/* Call tcp_fasttmr() every 250 ms */
darran	0:ac21159e27f4	106	tcp_fasttmr();
darran	0:ac21159e27f4	107
darran	0:ac21159e27f4	108	if (++tcp_timer & 1) {
darran	0:ac21159e27f4	109	/* Call tcp_tmr() every 500 ms, i.e., every other timer
darran	0:ac21159e27f4	110	tcp_tmr() is called. */
darran	0:ac21159e27f4	111	tcp_slowtmr();
darran	0:ac21159e27f4	112	}
darran	0:ac21159e27f4	113	}
darran	0:ac21159e27f4	114
darran	0:ac21159e27f4	115	/**
darran	0:ac21159e27f4	116	* Closes the TX side of a connection held by the PCB.
darran	0:ac21159e27f4	117	* For tcp_close(), a RST is sent if the application didn't receive all data
darran	0:ac21159e27f4	118	* (tcp_recved() not called for all data passed to recv callback).
darran	0:ac21159e27f4	119	*
darran	0:ac21159e27f4	120	* Listening pcbs are freed and may not be referenced any more.
darran	0:ac21159e27f4	121	* Connection pcbs are freed if not yet connected and may not be referenced
darran	0:ac21159e27f4	122	* any more. If a connection is established (at least SYN received or in
darran	0:ac21159e27f4	123	* a closing state), the connection is closed, and put in a closing state.
darran	0:ac21159e27f4	124	* The pcb is then automatically freed in tcp_slowtmr(). It is therefore
darran	0:ac21159e27f4	125	* unsafe to reference it.
darran	0:ac21159e27f4	126	*
darran	0:ac21159e27f4	127	* @param pcb the tcp_pcb to close
darran	0:ac21159e27f4	128	* @return ERR_OK if connection has been closed
darran	0:ac21159e27f4	129	* another err_t if closing failed and pcb is not freed
darran	0:ac21159e27f4	130	*/
darran	0:ac21159e27f4	131	static err_t
darran	0:ac21159e27f4	132	tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
darran	0:ac21159e27f4	133	{
darran	0:ac21159e27f4	134	err_t err;
darran	0:ac21159e27f4	135
darran	0:ac21159e27f4	136	if (rst_on_unacked_data && (pcb->state != LISTEN)) {
darran	0:ac21159e27f4	137	if ((pcb->refused_data != NULL) \|\| (pcb->rcv_wnd != TCP_WND)) {
darran	0:ac21159e27f4	138	/* Not all data received by application, send RST to tell the remote
darran	0:ac21159e27f4	139	side about this. */
darran	0:ac21159e27f4	140	tcp_rst(pcb->snd_nxt, pcb->rcv_nxt, &pcb->local_ip, &pcb->remote_ip,
darran	0:ac21159e27f4	141	pcb->local_port, pcb->remote_port);
darran	0:ac21159e27f4	142	}
darran	0:ac21159e27f4	143	}
darran	0:ac21159e27f4	144
darran	0:ac21159e27f4	145	switch (pcb->state) {
darran	0:ac21159e27f4	146	case CLOSED:
darran	0:ac21159e27f4	147	/* Closing a pcb in the CLOSED state might seem erroneous,
darran	0:ac21159e27f4	148	* however, it is in this state once allocated and as yet unused
darran	0:ac21159e27f4	149	* and the user needs some way to free it should the need arise.
darran	0:ac21159e27f4	150	* Calling tcp_close() with a pcb that has already been closed, (i.e. twice)
darran	0:ac21159e27f4	151	* or for a pcb that has been used and then entered the CLOSED state
darran	0:ac21159e27f4	152	* is erroneous, but this should never happen as the pcb has in those cases
darran	0:ac21159e27f4	153	* been freed, and so any remaining handles are bogus. */
darran	0:ac21159e27f4	154	err = ERR_OK;
darran	0:ac21159e27f4	155	TCP_RMV(&tcp_bound_pcbs, pcb);
darran	0:ac21159e27f4	156	memp_free(MEMP_TCP_PCB, pcb);
darran	0:ac21159e27f4	157	pcb = NULL;
darran	0:ac21159e27f4	158	break;
darran	0:ac21159e27f4	159	case LISTEN:
darran	0:ac21159e27f4	160	err = ERR_OK;
darran	0:ac21159e27f4	161	tcp_pcb_remove((struct tcp_pcb **)&tcp_listen_pcbs.pcbs, pcb);
darran	0:ac21159e27f4	162	memp_free(MEMP_TCP_PCB_LISTEN, pcb);
darran	0:ac21159e27f4	163	pcb = NULL;
darran	0:ac21159e27f4	164	break;
darran	0:ac21159e27f4	165	case SYN_SENT:
darran	0:ac21159e27f4	166	err = ERR_OK;
darran	0:ac21159e27f4	167	tcp_pcb_remove(&tcp_active_pcbs, pcb);
darran	0:ac21159e27f4	168	memp_free(MEMP_TCP_PCB, pcb);
darran	0:ac21159e27f4	169	pcb = NULL;
darran	0:ac21159e27f4	170	snmp_inc_tcpattemptfails();
darran	0:ac21159e27f4	171	break;
darran	0:ac21159e27f4	172	case SYN_RCVD:
darran	0:ac21159e27f4	173	err = tcp_send_fin(pcb);
darran	0:ac21159e27f4	174	if (err == ERR_OK) {
darran	0:ac21159e27f4	175	snmp_inc_tcpattemptfails();
darran	0:ac21159e27f4	176	pcb->state = FIN_WAIT_1;
darran	0:ac21159e27f4	177	}
darran	0:ac21159e27f4	178	break;
darran	0:ac21159e27f4	179	case ESTABLISHED:
darran	0:ac21159e27f4	180	err = tcp_send_fin(pcb);
darran	0:ac21159e27f4	181	if (err == ERR_OK) {
darran	0:ac21159e27f4	182	snmp_inc_tcpestabresets();
darran	0:ac21159e27f4	183	pcb->state = FIN_WAIT_1;
darran	0:ac21159e27f4	184	}
darran	0:ac21159e27f4	185	break;
darran	0:ac21159e27f4	186	case CLOSE_WAIT:
darran	0:ac21159e27f4	187	err = tcp_send_fin(pcb);
darran	0:ac21159e27f4	188	if (err == ERR_OK) {
darran	0:ac21159e27f4	189	snmp_inc_tcpestabresets();
darran	0:ac21159e27f4	190	pcb->state = LAST_ACK;
darran	0:ac21159e27f4	191	}
darran	0:ac21159e27f4	192	break;
darran	0:ac21159e27f4	193	default:
darran	0:ac21159e27f4	194	/* Has already been closed, do nothing. */
darran	0:ac21159e27f4	195	err = ERR_OK;
darran	0:ac21159e27f4	196	pcb = NULL;
darran	0:ac21159e27f4	197	break;
darran	0:ac21159e27f4	198	}
darran	0:ac21159e27f4	199
darran	0:ac21159e27f4	200	if (pcb != NULL && err == ERR_OK) {
darran	0:ac21159e27f4	201	/* To ensure all data has been sent when tcp_close returns, we have
darran	0:ac21159e27f4	202	to make sure tcp_output doesn't fail.
darran	0:ac21159e27f4	203	Since we don't really have to ensure all data has been sent when tcp_close
darran	0:ac21159e27f4	204	returns (unsent data is sent from tcp timer functions, also), we don't care
darran	0:ac21159e27f4	205	for the return value of tcp_output for now. */
darran	0:ac21159e27f4	206	/* @todo: When implementing SO_LINGER, this must be changed somehow:
darran	0:ac21159e27f4	207	If SOF_LINGER is set, the data should be sent and acked before close returns.
darran	0:ac21159e27f4	208	This can only be valid for sequential APIs, not for the raw API. */
darran	0:ac21159e27f4	209	tcp_output(pcb);
darran	0:ac21159e27f4	210	}
darran	0:ac21159e27f4	211	return err;
darran	0:ac21159e27f4	212	}
darran	0:ac21159e27f4	213
darran	0:ac21159e27f4	214	/**
darran	0:ac21159e27f4	215	* Closes the connection held by the PCB.
darran	0:ac21159e27f4	216	*
darran	0:ac21159e27f4	217	* Listening pcbs are freed and may not be referenced any more.
darran	0:ac21159e27f4	218	* Connection pcbs are freed if not yet connected and may not be referenced
darran	0:ac21159e27f4	219	* any more. If a connection is established (at least SYN received or in
darran	0:ac21159e27f4	220	* a closing state), the connection is closed, and put in a closing state.
darran	0:ac21159e27f4	221	* The pcb is then automatically freed in tcp_slowtmr(). It is therefore
darran	0:ac21159e27f4	222	* unsafe to reference it (unless an error is returned).
darran	0:ac21159e27f4	223	*
darran	0:ac21159e27f4	224	* @param pcb the tcp_pcb to close
darran	0:ac21159e27f4	225	* @return ERR_OK if connection has been closed
darran	0:ac21159e27f4	226	* another err_t if closing failed and pcb is not freed
darran	0:ac21159e27f4	227	*/
darran	0:ac21159e27f4	228	err_t
darran	0:ac21159e27f4	229	tcp_close(struct tcp_pcb *pcb)
darran	0:ac21159e27f4	230	{
darran	0:ac21159e27f4	231	#if TCP_DEBUG
darran	0:ac21159e27f4	232	LWIP_DEBUGF(TCP_DEBUG, ("tcp_close: closing in "));
darran	0:ac21159e27f4	233	tcp_debug_print_state(pcb->state);
darran	0:ac21159e27f4	234	#endif /* TCP_DEBUG */
darran	0:ac21159e27f4	235
darran	0:ac21159e27f4	236	if (pcb->state != LISTEN) {
darran	0:ac21159e27f4	237	/* Set a flag not to receive any more data... */
darran	0:ac21159e27f4	238	pcb->flags \|= TF_RXCLOSED;
darran	0:ac21159e27f4	239	}
darran	0:ac21159e27f4	240	/* ... and close */
darran	0:ac21159e27f4	241	return tcp_close_shutdown(pcb, 1);
darran	0:ac21159e27f4	242	}
darran	0:ac21159e27f4	243
darran	0:ac21159e27f4	244	/**
darran	0:ac21159e27f4	245	* Causes all or part of a full-duplex connection of this PCB to be shut down.
darran	0:ac21159e27f4	246	* This doesn't deallocate the PCB!
darran	0:ac21159e27f4	247	*
darran	0:ac21159e27f4	248	* @param pcb PCB to shutdown
darran	0:ac21159e27f4	249	* @param shut_rx shut down receive side if this is != 0
darran	0:ac21159e27f4	250	* @param shut_tx shut down send side if this is != 0
darran	0:ac21159e27f4	251	* @return ERR_OK if shutdown succeeded (or the PCB has already been shut down)
darran	0:ac21159e27f4	252	* another err_t on error.
darran	0:ac21159e27f4	253	*/
darran	0:ac21159e27f4	254	err_t
darran	0:ac21159e27f4	255	tcp_shutdown(struct tcp_pcb *pcb, int shut_rx, int shut_tx)
darran	0:ac21159e27f4	256	{
darran	0:ac21159e27f4	257	if (pcb->state == LISTEN) {
darran	0:ac21159e27f4	258	return ERR_CONN;
darran	0:ac21159e27f4	259	}
darran	0:ac21159e27f4	260	if (shut_rx) {
darran	0:ac21159e27f4	261	/* shut down the receive side: free buffered data... */
darran	0:ac21159e27f4	262	if (pcb->refused_data != NULL) {
darran	0:ac21159e27f4	263	pbuf_free(pcb->refused_data);
darran	0:ac21159e27f4	264	pcb->refused_data = NULL;
darran	0:ac21159e27f4	265	}
darran	0:ac21159e27f4	266	/* ... and set a flag not to receive any more data */
darran	0:ac21159e27f4	267	pcb->flags \|= TF_RXCLOSED;
darran	0:ac21159e27f4	268	}
darran	0:ac21159e27f4	269	if (shut_tx) {
darran	0:ac21159e27f4	270	/* This can't happen twice since if it succeeds, the pcb's state is changed.
darran	0:ac21159e27f4	271	Only close in these states as the others directly deallocate the PCB */
darran	0:ac21159e27f4	272	switch (pcb->state) {
darran	0:ac21159e27f4	273	case SYN_RCVD:
darran	0:ac21159e27f4	274	case ESTABLISHED:
darran	0:ac21159e27f4	275	case CLOSE_WAIT:
darran	0:ac21159e27f4	276	return tcp_close_shutdown(pcb, 0);
darran	0:ac21159e27f4	277	default:
darran	0:ac21159e27f4	278	/* don't shut down other states */
darran	0:ac21159e27f4	279	break;
darran	0:ac21159e27f4	280	}
darran	0:ac21159e27f4	281	}
darran	0:ac21159e27f4	282	/* @todo: return another err_t if not in correct state or already shut? */
darran	0:ac21159e27f4	283	return ERR_OK;
darran	0:ac21159e27f4	284	}
darran	0:ac21159e27f4	285
darran	0:ac21159e27f4	286	/**
darran	0:ac21159e27f4	287	* Abandons a connection and optionally sends a RST to the remote
darran	0:ac21159e27f4	288	* host. Deletes the local protocol control block. This is done when
darran	0:ac21159e27f4	289	* a connection is killed because of shortage of memory.
darran	0:ac21159e27f4	290	*
darran	0:ac21159e27f4	291	* @param pcb the tcp_pcb to abort
darran	0:ac21159e27f4	292	* @param reset boolean to indicate whether a reset should be sent
darran	0:ac21159e27f4	293	*/
darran	0:ac21159e27f4	294	void
darran	0:ac21159e27f4	295	tcp_abandon(struct tcp_pcb *pcb, int reset)
darran	0:ac21159e27f4	296	{
darran	0:ac21159e27f4	297	u32_t seqno, ackno;
darran	0:ac21159e27f4	298	u16_t remote_port, local_port;
darran	0:ac21159e27f4	299	ip_addr_t remote_ip, local_ip;
darran	0:ac21159e27f4	300	#if LWIP_CALLBACK_API
darran	0:ac21159e27f4	301	tcp_err_fn errf;
darran	0:ac21159e27f4	302	#endif /* LWIP_CALLBACK_API */
darran	0:ac21159e27f4	303	void *errf_arg;
darran	0:ac21159e27f4	304
darran	0:ac21159e27f4	305
darran	0:ac21159e27f4	306	/* Figure out on which TCP PCB list we are, and remove us. If we
darran	0:ac21159e27f4	307	are in an active state, call the receive function associated with
darran	0:ac21159e27f4	308	the PCB with a NULL argument, and send an RST to the remote end. */
darran	0:ac21159e27f4	309	if (pcb->state == TIME_WAIT) {
darran	0:ac21159e27f4	310	tcp_pcb_remove(&tcp_tw_pcbs, pcb);
darran	0:ac21159e27f4	311	memp_free(MEMP_TCP_PCB, pcb);
darran	0:ac21159e27f4	312	} else {
darran	0:ac21159e27f4	313	/* @todo: pcb->state, LISTEN not allowed */
darran	0:ac21159e27f4	314	seqno = pcb->snd_nxt;
darran	0:ac21159e27f4	315	ackno = pcb->rcv_nxt;
darran	0:ac21159e27f4	316	ip_addr_copy(local_ip, pcb->local_ip);
darran	0:ac21159e27f4	317	ip_addr_copy(remote_ip, pcb->remote_ip);
darran	0:ac21159e27f4	318	local_port = pcb->local_port;
darran	0:ac21159e27f4	319	remote_port = pcb->remote_port;
darran	0:ac21159e27f4	320	#if LWIP_CALLBACK_API
darran	0:ac21159e27f4	321	errf = pcb->errf;
darran	0:ac21159e27f4	322	#endif /* LWIP_CALLBACK_API */
darran	0:ac21159e27f4	323	errf_arg = pcb->callback_arg;
darran	0:ac21159e27f4	324	tcp_pcb_remove(&tcp_active_pcbs, pcb);
darran	0:ac21159e27f4	325	if (pcb->unacked != NULL) {
darran	0:ac21159e27f4	326	tcp_segs_free(pcb->unacked);
darran	0:ac21159e27f4	327	}
darran	0:ac21159e27f4	328	if (pcb->unsent != NULL) {
darran	0:ac21159e27f4	329	tcp_segs_free(pcb->unsent);
darran	0:ac21159e27f4	330	}
darran	0:ac21159e27f4	331	#if TCP_QUEUE_OOSEQ
darran	0:ac21159e27f4	332	if (pcb->ooseq != NULL) {
darran	0:ac21159e27f4	333	tcp_segs_free(pcb->ooseq);
darran	0:ac21159e27f4	334	}
darran	0:ac21159e27f4	335	#endif /* TCP_QUEUE_OOSEQ */
darran	0:ac21159e27f4	336	memp_free(MEMP_TCP_PCB, pcb);
darran	0:ac21159e27f4	337	TCP_EVENT_ERR(errf, errf_arg, ERR_ABRT);
darran	0:ac21159e27f4	338	if (reset) {
darran	0:ac21159e27f4	339	LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_abandon: sending RST\n"));
darran	0:ac21159e27f4	340	tcp_rst(seqno, ackno, &local_ip, &remote_ip, local_port, remote_port);
darran	0:ac21159e27f4	341	}
darran	0:ac21159e27f4	342	}
darran	0:ac21159e27f4	343	}
darran	0:ac21159e27f4	344
darran	0:ac21159e27f4	345	/**
darran	0:ac21159e27f4	346	* Aborts the connection by sending a RST (reset) segment to the remote
darran	0:ac21159e27f4	347	* host. The pcb is deallocated. This function never fails.
darran	0:ac21159e27f4	348	*
darran	0:ac21159e27f4	349	* ATTENTION: When calling this from one of the TCP callbacks, make
darran	0:ac21159e27f4	350	* sure you always return ERR_ABRT (and never return ERR_ABRT otherwise
darran	0:ac21159e27f4	351	* or you will risk accessing deallocated memory or memory leaks!
darran	0:ac21159e27f4	352	*
darran	0:ac21159e27f4	353	* @param pcb the tcp pcb to abort
darran	0:ac21159e27f4	354	*/
darran	0:ac21159e27f4	355	void
darran	0:ac21159e27f4	356	tcp_abort(struct tcp_pcb *pcb)
darran	0:ac21159e27f4	357	{
darran	0:ac21159e27f4	358	tcp_abandon(pcb, 1);
darran	0:ac21159e27f4	359	}
darran	0:ac21159e27f4	360
darran	0:ac21159e27f4	361	/**
darran	0:ac21159e27f4	362	* Binds the connection to a local portnumber and IP address. If the
darran	0:ac21159e27f4	363	* IP address is not given (i.e., ipaddr == NULL), the IP address of
darran	0:ac21159e27f4	364	* the outgoing network interface is used instead.
darran	0:ac21159e27f4	365	*
darran	0:ac21159e27f4	366	* @param pcb the tcp_pcb to bind (no check is done whether this pcb is
darran	0:ac21159e27f4	367	* already bound!)
darran	0:ac21159e27f4	368	* @param ipaddr the local ip address to bind to (use IP_ADDR_ANY to bind
darran	0:ac21159e27f4	369	* to any local address
darran	0:ac21159e27f4	370	* @param port the local port to bind to
darran	0:ac21159e27f4	371	* @return ERR_USE if the port is already in use
darran	0:ac21159e27f4	372	* ERR_OK if bound
darran	0:ac21159e27f4	373	*/
darran	0:ac21159e27f4	374	err_t
darran	0:ac21159e27f4	375	tcp_bind(struct tcp_pcb pcb, ip_addr_t ipaddr, u16_t port)
darran	0:ac21159e27f4	376	{
darran	0:ac21159e27f4	377	struct tcp_pcb *cpcb;
darran	0:ac21159e27f4	378
darran	0:ac21159e27f4	379	LWIP_ERROR("tcp_bind: can only bind in state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
darran	0:ac21159e27f4	380
darran	0:ac21159e27f4	381	if (port == 0) {
darran	0:ac21159e27f4	382	port = tcp_new_port();
darran	0:ac21159e27f4	383	}
darran	0:ac21159e27f4	384	/* Check if the address already is in use. */
darran	0:ac21159e27f4	385	/* Check the listen pcbs. */
darran	0:ac21159e27f4	386	for(cpcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs;
darran	0:ac21159e27f4	387	cpcb != NULL; cpcb = cpcb->next) {
darran	0:ac21159e27f4	388	if (cpcb->local_port == port) {
darran	0:ac21159e27f4	389	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
darran	0:ac21159e27f4	390	ip_addr_isany(ipaddr) \|\|
darran	0:ac21159e27f4	391	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
darran	0:ac21159e27f4	392	return ERR_USE;
darran	0:ac21159e27f4	393	}
darran	0:ac21159e27f4	394	}
darran	0:ac21159e27f4	395	}
darran	0:ac21159e27f4	396	/* Check the connected pcbs. */
darran	0:ac21159e27f4	397	for(cpcb = tcp_active_pcbs;
darran	0:ac21159e27f4	398	cpcb != NULL; cpcb = cpcb->next) {
darran	0:ac21159e27f4	399	if (cpcb->local_port == port) {
darran	0:ac21159e27f4	400	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
darran	0:ac21159e27f4	401	ip_addr_isany(ipaddr) \|\|
darran	0:ac21159e27f4	402	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
darran	0:ac21159e27f4	403	return ERR_USE;
darran	0:ac21159e27f4	404	}
darran	0:ac21159e27f4	405	}
darran	0:ac21159e27f4	406	}
darran	0:ac21159e27f4	407	/* Check the bound, not yet connected pcbs. */
darran	0:ac21159e27f4	408	for(cpcb = tcp_bound_pcbs; cpcb != NULL; cpcb = cpcb->next) {
darran	0:ac21159e27f4	409	if (cpcb->local_port == port) {
darran	0:ac21159e27f4	410	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
darran	0:ac21159e27f4	411	ip_addr_isany(ipaddr) \|\|
darran	0:ac21159e27f4	412	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
darran	0:ac21159e27f4	413	return ERR_USE;
darran	0:ac21159e27f4	414	}
darran	0:ac21159e27f4	415	}
darran	0:ac21159e27f4	416	}
darran	0:ac21159e27f4	417	/* Unless the REUSEADDR flag is set,
darran	0:ac21159e27f4	418	* we have to check the pcbs in TIME-WAIT state, also: */
darran	0:ac21159e27f4	419	if ((pcb->so_options & SOF_REUSEADDR) == 0) {
darran	0:ac21159e27f4	420	for(cpcb = tcp_tw_pcbs; cpcb != NULL; cpcb = cpcb->next) {
darran	0:ac21159e27f4	421	if (cpcb->local_port == port) {
darran	0:ac21159e27f4	422	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
darran	0:ac21159e27f4	423	ip_addr_isany(ipaddr) \|\|
darran	0:ac21159e27f4	424	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
darran	0:ac21159e27f4	425	return ERR_USE;
darran	0:ac21159e27f4	426	}
darran	0:ac21159e27f4	427	}
darran	0:ac21159e27f4	428	}
darran	0:ac21159e27f4	429	}
darran	0:ac21159e27f4	430
darran	0:ac21159e27f4	431	if (!ip_addr_isany(ipaddr)) {
darran	0:ac21159e27f4	432	pcb->local_ip = *ipaddr;
darran	0:ac21159e27f4	433	}
darran	0:ac21159e27f4	434	pcb->local_port = port;
darran	0:ac21159e27f4	435	TCP_REG(&tcp_bound_pcbs, pcb);
darran	0:ac21159e27f4	436	LWIP_DEBUGF(TCP_DEBUG, ("tcp_bind: bind to port %"U16_F"\n", port));
darran	0:ac21159e27f4	437	return ERR_OK;
darran	0:ac21159e27f4	438	}
darran	0:ac21159e27f4	439	#if LWIP_CALLBACK_API
darran	0:ac21159e27f4	440	/**
darran	0:ac21159e27f4	441	* Default accept callback if no accept callback is specified by the user.
darran	0:ac21159e27f4	442	*/
darran	0:ac21159e27f4	443	static err_t
darran	0:ac21159e27f4	444	tcp_accept_null(void arg, struct tcp_pcb pcb, err_t err)
darran	0:ac21159e27f4	445	{
darran	0:ac21159e27f4	446	LWIP_UNUSED_ARG(arg);
darran	0:ac21159e27f4	447	LWIP_UNUSED_ARG(pcb);
darran	0:ac21159e27f4	448	LWIP_UNUSED_ARG(err);
darran	0:ac21159e27f4	449
darran	0:ac21159e27f4	450	return ERR_ABRT;
darran	0:ac21159e27f4	451	}
darran	0:ac21159e27f4	452	#endif /* LWIP_CALLBACK_API */
darran	0:ac21159e27f4	453
darran	0:ac21159e27f4	454	/**
darran	0:ac21159e27f4	455	* Set the state of the connection to be LISTEN, which means that it
darran	0:ac21159e27f4	456	* is able to accept incoming connections. The protocol control block
darran	0:ac21159e27f4	457	* is reallocated in order to consume less memory. Setting the
darran	0:ac21159e27f4	458	* connection to LISTEN is an irreversible process.
darran	0:ac21159e27f4	459	*
darran	0:ac21159e27f4	460	* @param pcb the original tcp_pcb
darran	0:ac21159e27f4	461	* @param backlog the incoming connections queue limit
darran	0:ac21159e27f4	462	* @return tcp_pcb used for listening, consumes less memory.
darran	0:ac21159e27f4	463	*
darran	0:ac21159e27f4	464	* @note The original tcp_pcb is freed. This function therefore has to be
darran	0:ac21159e27f4	465	* called like this:
darran	0:ac21159e27f4	466	* tpcb = tcp_listen(tpcb);
darran	0:ac21159e27f4	467	*/
darran	0:ac21159e27f4	468	struct tcp_pcb *
darran	0:ac21159e27f4	469	tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog)
darran	0:ac21159e27f4	470	{
darran	0:ac21159e27f4	471	struct tcp_pcb_listen *lpcb;
darran	0:ac21159e27f4	472
darran	0:ac21159e27f4	473	LWIP_UNUSED_ARG(backlog);
darran	0:ac21159e27f4	474	LWIP_ERROR("tcp_listen: pcb already connected", pcb->state == CLOSED, return NULL);
darran	0:ac21159e27f4	475
darran	0:ac21159e27f4	476	/* already listening? */
darran	0:ac21159e27f4	477	if (pcb->state == LISTEN) {
darran	0:ac21159e27f4	478	return pcb;
darran	0:ac21159e27f4	479	}
darran	0:ac21159e27f4	480	lpcb = (struct tcp_pcb_listen *)memp_malloc(MEMP_TCP_PCB_LISTEN);
darran	0:ac21159e27f4	481	if (lpcb == NULL) {
darran	0:ac21159e27f4	482	return NULL;
darran	0:ac21159e27f4	483	}
darran	0:ac21159e27f4	484	lpcb->callback_arg = pcb->callback_arg;
darran	0:ac21159e27f4	485	lpcb->local_port = pcb->local_port;
darran	0:ac21159e27f4	486	lpcb->state = LISTEN;
darran	0:ac21159e27f4	487	lpcb->so_options = pcb->so_options;
darran	0:ac21159e27f4	488	lpcb->so_options \|= SOF_ACCEPTCONN;
darran	0:ac21159e27f4	489	lpcb->ttl = pcb->ttl;
darran	0:ac21159e27f4	490	lpcb->tos = pcb->tos;
darran	0:ac21159e27f4	491	ip_addr_copy(lpcb->local_ip, pcb->local_ip);
darran	0:ac21159e27f4	492	TCP_RMV(&tcp_bound_pcbs, pcb);
darran	0:ac21159e27f4	493	memp_free(MEMP_TCP_PCB, pcb);
darran	0:ac21159e27f4	494	#if LWIP_CALLBACK_API
darran	0:ac21159e27f4	495	lpcb->accept = tcp_accept_null;
darran	0:ac21159e27f4	496	#endif /* LWIP_CALLBACK_API */
darran	0:ac21159e27f4	497	#if TCP_LISTEN_BACKLOG
darran	0:ac21159e27f4	498	lpcb->accepts_pending = 0;
darran	0:ac21159e27f4	499	lpcb->backlog = (backlog ? backlog : 1);
darran	0:ac21159e27f4	500	#endif /* TCP_LISTEN_BACKLOG */
darran	0:ac21159e27f4	501	TCP_REG(&tcp_listen_pcbs.listen_pcbs, lpcb);
darran	0:ac21159e27f4	502	return (struct tcp_pcb *)lpcb;
darran	0:ac21159e27f4	503	}
darran	0:ac21159e27f4	504
darran	0:ac21159e27f4	505	/**
darran	0:ac21159e27f4	506	* Update the state that tracks the available window space to advertise.
darran	0:ac21159e27f4	507	*
darran	0:ac21159e27f4	508	* Returns how much extra window would be advertised if we sent an
darran	0:ac21159e27f4	509	* update now.
darran	0:ac21159e27f4	510	*/
darran	0:ac21159e27f4	511	u32_t tcp_update_rcv_ann_wnd(struct tcp_pcb *pcb)
darran	0:ac21159e27f4	512	{
darran	0:ac21159e27f4	513	u32_t new_right_edge = pcb->rcv_nxt + pcb->rcv_wnd;
darran	0:ac21159e27f4	514
darran	0:ac21159e27f4	515	if (TCP_SEQ_GEQ(new_right_edge, pcb->rcv_ann_right_edge + LWIP_MIN((TCP_WND / 2), pcb->mss))) {
darran	0:ac21159e27f4	516	/* we can advertise more window */
darran	0:ac21159e27f4	517	pcb->rcv_ann_wnd = pcb->rcv_wnd;
darran	0:ac21159e27f4	518	return new_right_edge - pcb->rcv_ann_right_edge;
darran	0:ac21159e27f4	519	} else {
darran	0:ac21159e27f4	520	if (TCP_SEQ_GT(pcb->rcv_nxt, pcb->rcv_ann_right_edge)) {
darran	0:ac21159e27f4	521	/* Can happen due to other end sending out of advertised window,
darran	0:ac21159e27f4	522	* but within actual available (but not yet advertised) window */
darran	0:ac21159e27f4	523	pcb->rcv_ann_wnd = 0;
darran	0:ac21159e27f4	524	} else {
darran	0:ac21159e27f4	525	/* keep the right edge of window constant */
darran	0:ac21159e27f4	526	u32_t new_rcv_ann_wnd = pcb->rcv_ann_right_edge - pcb->rcv_nxt;
darran	0:ac21159e27f4	527	LWIP_ASSERT("new_rcv_ann_wnd <= 0xffff", new_rcv_ann_wnd <= 0xffff);
darran	0:ac21159e27f4	528	pcb->rcv_ann_wnd = (u16_t)new_rcv_ann_wnd;
darran	0:ac21159e27f4	529	}
darran	0:ac21159e27f4	530	return 0;
darran	0:ac21159e27f4	531	}
darran	0:ac21159e27f4	532	}
darran	0:ac21159e27f4	533
darran	0:ac21159e27f4	534	/**
darran	0:ac21159e27f4	535	* This function should be called by the application when it has
darran	0:ac21159e27f4	536	* processed the data. The purpose is to advertise a larger window
darran	0:ac21159e27f4	537	* when the data has been processed.
darran	0:ac21159e27f4	538	*
darran	0:ac21159e27f4	539	* @param pcb the tcp_pcb for which data is read
darran	0:ac21159e27f4	540	* @param len the amount of bytes that have been read by the application
darran	0:ac21159e27f4	541	*/
darran	0:ac21159e27f4	542	void
darran	0:ac21159e27f4	543	tcp_recved(struct tcp_pcb *pcb, u16_t len)
darran	0:ac21159e27f4	544	{
darran	0:ac21159e27f4	545	int wnd_inflation;
darran	0:ac21159e27f4	546
darran	0:ac21159e27f4	547	LWIP_ASSERT("tcp_recved: len would wrap rcv_wnd\n",
darran	0:ac21159e27f4	548	len <= 0xffff - pcb->rcv_wnd );
darran	0:ac21159e27f4	549
darran	0:ac21159e27f4	550	pcb->rcv_wnd += len;
darran	0:ac21159e27f4	551	if (pcb->rcv_wnd > TCP_WND) {
darran	0:ac21159e27f4	552	pcb->rcv_wnd = TCP_WND;
darran	0:ac21159e27f4	553	}
darran	0:ac21159e27f4	554
darran	0:ac21159e27f4	555	wnd_inflation = tcp_update_rcv_ann_wnd(pcb);
darran	0:ac21159e27f4	556
darran	0:ac21159e27f4	557	/* If the change in the right edge of window is significant (default
darran	0:ac21159e27f4	558	* watermark is TCP_WND/4), then send an explicit update now.
darran	0:ac21159e27f4	559	* Otherwise wait for a packet to be sent in the normal course of
darran	0:ac21159e27f4	560	* events (or more window to be available later) */
darran	0:ac21159e27f4	561	if (wnd_inflation >= TCP_WND_UPDATE_THRESHOLD) {
darran	0:ac21159e27f4	562	tcp_ack_now(pcb);
darran	0:ac21159e27f4	563	tcp_output(pcb);
darran	0:ac21159e27f4	564	}
darran	0:ac21159e27f4	565
darran	0:ac21159e27f4	566	LWIP_DEBUGF(TCP_DEBUG, ("tcp_recved: recveived %"U16_F" bytes, wnd %"U16_F" (%"U16_F").\n",
darran	0:ac21159e27f4	567	len, pcb->rcv_wnd, TCP_WND - pcb->rcv_wnd));
darran	0:ac21159e27f4	568	}
darran	0:ac21159e27f4	569
darran	0:ac21159e27f4	570	/**
darran	0:ac21159e27f4	571	* A nastly hack featuring 'goto' statements that allocates a
darran	0:ac21159e27f4	572	* new TCP local port.
darran	0:ac21159e27f4	573	*
darran	0:ac21159e27f4	574	* @return a new (free) local TCP port number
darran	0:ac21159e27f4	575	*/
darran	0:ac21159e27f4	576	static u16_t
darran	0:ac21159e27f4	577	tcp_new_port(void)
darran	0:ac21159e27f4	578	{
darran	0:ac21159e27f4	579	struct tcp_pcb *pcb;
darran	0:ac21159e27f4	580	#ifndef TCP_LOCAL_PORT_RANGE_START
darran	0:ac21159e27f4	581	#define TCP_LOCAL_PORT_RANGE_START 4096
darran	0:ac21159e27f4	582	#define TCP_LOCAL_PORT_RANGE_END 0x7fff
darran	0:ac21159e27f4	583	#endif
darran	0:ac21159e27f4	584	static u16_t port = TCP_LOCAL_PORT_RANGE_START;
darran	0:ac21159e27f4	585
darran	0:ac21159e27f4	586	again:
darran	0:ac21159e27f4	587	if (++port > TCP_LOCAL_PORT_RANGE_END) {
darran	0:ac21159e27f4	588	port = TCP_LOCAL_PORT_RANGE_START;
darran	0:ac21159e27f4	589	}
darran	0:ac21159e27f4	590
darran	0:ac21159e27f4	591	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
darran	0:ac21159e27f4	592	if (pcb->local_port == port) {
darran	0:ac21159e27f4	593	goto again;
darran	0:ac21159e27f4	594	}
darran	0:ac21159e27f4	595	}
darran	0:ac21159e27f4	596	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
darran	0:ac21159e27f4	597	if (pcb->local_port == port) {
darran	0:ac21159e27f4	598	goto again;
darran	0:ac21159e27f4	599	}
darran	0:ac21159e27f4	600	}
darran	0:ac21159e27f4	601	for(pcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs; pcb != NULL; pcb = pcb->next) {
darran	0:ac21159e27f4	602	if (pcb->local_port == port) {
darran	0:ac21159e27f4	603	goto again;
darran	0:ac21159e27f4	604	}
darran	0:ac21159e27f4	605	}
darran	0:ac21159e27f4	606	return port;
darran	0:ac21159e27f4	607	}
darran	0:ac21159e27f4	608
darran	0:ac21159e27f4	609	/**
darran	0:ac21159e27f4	610	* Connects to another host. The function given as the "connected"
darran	0:ac21159e27f4	611	* argument will be called when the connection has been established.
darran	0:ac21159e27f4	612	*
darran	0:ac21159e27f4	613	* @param pcb the tcp_pcb used to establish the connection
darran	0:ac21159e27f4	614	* @param ipaddr the remote ip address to connect to
darran	0:ac21159e27f4	615	* @param port the remote tcp port to connect to
darran	0:ac21159e27f4	616	* @param connected callback function to call when connected (or on error)
darran	0:ac21159e27f4	617	* @return ERR_VAL if invalid arguments are given
darran	0:ac21159e27f4	618	* ERR_OK if connect request has been sent
darran	0:ac21159e27f4	619	* other err_t values if connect request couldn't be sent
darran	0:ac21159e27f4	620	*/
darran	0:ac21159e27f4	621	err_t
darran	0:ac21159e27f4	622	tcp_connect(struct tcp_pcb pcb, ip_addr_t ipaddr, u16_t port,
darran	0:ac21159e27f4	623	tcp_connected_fn connected)
darran	0:ac21159e27f4	624	{
darran	0:ac21159e27f4	625	err_t ret;
darran	0:ac21159e27f4	626	u32_t iss;
darran	0:ac21159e27f4	627
darran	0:ac21159e27f4	628	LWIP_ERROR("tcp_connect: can only connected from state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
darran	0:ac21159e27f4	629
darran	0:ac21159e27f4	630	LWIP_DEBUGF(TCP_DEBUG, ("tcp_connect to port %"U16_F"\n", port));
darran	0:ac21159e27f4	631	if (ipaddr != NULL) {
darran	0:ac21159e27f4	632	pcb->remote_ip = *ipaddr;
darran	0:ac21159e27f4	633	} else {
darran	0:ac21159e27f4	634	return ERR_VAL;
darran	0:ac21159e27f4	635	}
darran	0:ac21159e27f4	636	pcb->remote_port = port;
darran	0:ac21159e27f4	637	if (pcb->local_port == 0) {
darran	0:ac21159e27f4	638	pcb->local_port = tcp_new_port();
darran	0:ac21159e27f4	639	}
darran	0:ac21159e27f4	640	iss = tcp_next_iss();
darran	0:ac21159e27f4	641	pcb->rcv_nxt = 0;
darran	0:ac21159e27f4	642	pcb->snd_nxt = iss;
darran	0:ac21159e27f4	643	pcb->lastack = iss - 1;
darran	0:ac21159e27f4	644	pcb->snd_lbb = iss - 1;
darran	0:ac21159e27f4	645	pcb->rcv_wnd = TCP_WND;
darran	0:ac21159e27f4	646	pcb->rcv_ann_wnd = TCP_WND;
darran	0:ac21159e27f4	647	pcb->rcv_ann_right_edge = pcb->rcv_nxt;
darran	0:ac21159e27f4	648	pcb->snd_wnd = TCP_WND;
darran	0:ac21159e27f4	649	/* As initial send MSS, we use TCP_MSS but limit it to 536.
darran	0:ac21159e27f4	650	The send MSS is updated when an MSS option is received. */
darran	0:ac21159e27f4	651	pcb->mss = (TCP_MSS > 536) ? 536 : TCP_MSS;
darran	0:ac21159e27f4	652	#if TCP_CALCULATE_EFF_SEND_MSS
darran	0:ac21159e27f4	653	pcb->mss = tcp_eff_send_mss(pcb->mss, ipaddr);
darran	0:ac21159e27f4	654	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
darran	0:ac21159e27f4	655	pcb->cwnd = 1;
darran	0:ac21159e27f4	656	pcb->ssthresh = pcb->mss * 10;
darran	0:ac21159e27f4	657	#if LWIP_CALLBACK_API
darran	0:ac21159e27f4	658	pcb->connected = connected;
darran	0:ac21159e27f4	659	#endif /* LWIP_CALLBACK_API */
darran	0:ac21159e27f4	660
darran	0:ac21159e27f4	661	/* Send a SYN together with the MSS option. */
darran	0:ac21159e27f4	662	ret = tcp_enqueue_flags(pcb, TCP_SYN);
darran	0:ac21159e27f4	663	if (ret == ERR_OK) {
darran	0:ac21159e27f4	664	/* SYN segment was enqueued, changed the pcbs state now */
darran	0:ac21159e27f4	665	pcb->state = SYN_SENT;
darran	0:ac21159e27f4	666	TCP_RMV(&tcp_bound_pcbs, pcb);
darran	0:ac21159e27f4	667	TCP_REG(&tcp_active_pcbs, pcb);
darran	0:ac21159e27f4	668	snmp_inc_tcpactiveopens();
darran	0:ac21159e27f4	669
darran	0:ac21159e27f4	670	tcp_output(pcb);
darran	0:ac21159e27f4	671	}
darran	0:ac21159e27f4	672	return ret;
darran	0:ac21159e27f4	673	}
darran	0:ac21159e27f4	674
darran	0:ac21159e27f4	675	/**
darran	0:ac21159e27f4	676	* Called every 500 ms and implements the retransmission timer and the timer that
darran	0:ac21159e27f4	677	* removes PCBs that have been in TIME-WAIT for enough time. It also increments
darran	0:ac21159e27f4	678	* various timers such as the inactivity timer in each PCB.
darran	0:ac21159e27f4	679	*
darran	0:ac21159e27f4	680	* Automatically called from tcp_tmr().
darran	0:ac21159e27f4	681	*/
darran	0:ac21159e27f4	682	void
darran	0:ac21159e27f4	683	tcp_slowtmr(void)
darran	0:ac21159e27f4	684	{
darran	0:ac21159e27f4	685	struct tcp_pcb pcb, pcb2, *prev;
darran	0:ac21159e27f4	686	u16_t eff_wnd;
darran	0:ac21159e27f4	687	u8_t pcb_remove; /* flag if a PCB should be removed */
darran	0:ac21159e27f4	688	u8_t pcb_reset; /* flag if a RST should be sent when removing */
darran	0:ac21159e27f4	689	err_t err;
darran	0:ac21159e27f4	690
darran	0:ac21159e27f4	691	err = ERR_OK;
darran	0:ac21159e27f4	692
darran	0:ac21159e27f4	693	++tcp_ticks;
darran	0:ac21159e27f4	694
darran	0:ac21159e27f4	695	/* Steps through all of the active PCBs. */
darran	0:ac21159e27f4	696	prev = NULL;
darran	0:ac21159e27f4	697	pcb = tcp_active_pcbs;
darran	0:ac21159e27f4	698	if (pcb == NULL) {
darran	0:ac21159e27f4	699	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: no active pcbs\n"));
darran	0:ac21159e27f4	700	}
darran	0:ac21159e27f4	701	while (pcb != NULL) {
darran	0:ac21159e27f4	702	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: processing active pcb\n"));
darran	0:ac21159e27f4	703	LWIP_ASSERT("tcp_slowtmr: active pcb->state != CLOSED\n", pcb->state != CLOSED);
darran	0:ac21159e27f4	704	LWIP_ASSERT("tcp_slowtmr: active pcb->state != LISTEN\n", pcb->state != LISTEN);
darran	0:ac21159e27f4	705	LWIP_ASSERT("tcp_slowtmr: active pcb->state != TIME-WAIT\n", pcb->state != TIME_WAIT);
darran	0:ac21159e27f4	706
darran	0:ac21159e27f4	707	pcb_remove = 0;
darran	0:ac21159e27f4	708	pcb_reset = 0;
darran	0:ac21159e27f4	709
darran	0:ac21159e27f4	710	if (pcb->state == SYN_SENT && pcb->nrtx == TCP_SYNMAXRTX) {
darran	0:ac21159e27f4	711	++pcb_remove;
darran	0:ac21159e27f4	712	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max SYN retries reached\n"));
darran	0:ac21159e27f4	713	}
darran	0:ac21159e27f4	714	else if (pcb->nrtx == TCP_MAXRTX) {
darran	0:ac21159e27f4	715	++pcb_remove;
darran	0:ac21159e27f4	716	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max DATA retries reached\n"));
darran	0:ac21159e27f4	717	} else {
darran	0:ac21159e27f4	718	if (pcb->persist_backoff > 0) {
darran	0:ac21159e27f4	719	/* If snd_wnd is zero, use persist timer to send 1 byte probes
darran	0:ac21159e27f4	720	* instead of using the standard retransmission mechanism. */
darran	0:ac21159e27f4	721	pcb->persist_cnt++;
darran	0:ac21159e27f4	722	if (pcb->persist_cnt >= tcp_persist_backoff[pcb->persist_backoff-1]) {
darran	0:ac21159e27f4	723	pcb->persist_cnt = 0;
darran	0:ac21159e27f4	724	if (pcb->persist_backoff < sizeof(tcp_persist_backoff)) {
darran	0:ac21159e27f4	725	pcb->persist_backoff++;
darran	0:ac21159e27f4	726	}
darran	0:ac21159e27f4	727	tcp_zero_window_probe(pcb);
darran	0:ac21159e27f4	728	}
darran	0:ac21159e27f4	729	} else {
darran	0:ac21159e27f4	730	/* Increase the retransmission timer if it is running */
darran	0:ac21159e27f4	731	if(pcb->rtime >= 0)
darran	0:ac21159e27f4	732	++pcb->rtime;
darran	0:ac21159e27f4	733
darran	0:ac21159e27f4	734	if (pcb->unacked != NULL && pcb->rtime >= pcb->rto) {
darran	0:ac21159e27f4	735	/* Time for a retransmission. */
darran	0:ac21159e27f4	736	LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_slowtmr: rtime %"S16_F
darran	0:ac21159e27f4	737	" pcb->rto %"S16_F"\n",
darran	0:ac21159e27f4	738	pcb->rtime, pcb->rto));
darran	0:ac21159e27f4	739
darran	0:ac21159e27f4	740	/* Double retransmission time-out unless we are trying to
darran	0:ac21159e27f4	741	* connect to somebody (i.e., we are in SYN_SENT). */
darran	0:ac21159e27f4	742	if (pcb->state != SYN_SENT) {
darran	0:ac21159e27f4	743	pcb->rto = ((pcb->sa >> 3) + pcb->sv) << tcp_backoff[pcb->nrtx];
darran	0:ac21159e27f4	744	}
darran	0:ac21159e27f4	745
darran	0:ac21159e27f4	746	/* Reset the retransmission timer. */
darran	0:ac21159e27f4	747	pcb->rtime = 0;
darran	0:ac21159e27f4	748
darran	0:ac21159e27f4	749	/* Reduce congestion window and ssthresh. */
darran	0:ac21159e27f4	750	eff_wnd = LWIP_MIN(pcb->cwnd, pcb->snd_wnd);
darran	0:ac21159e27f4	751	pcb->ssthresh = eff_wnd >> 1;
darran	0:ac21159e27f4	752	if (pcb->ssthresh < (pcb->mss << 1)) {
darran	0:ac21159e27f4	753	pcb->ssthresh = (pcb->mss << 1);
darran	0:ac21159e27f4	754	}
darran	0:ac21159e27f4	755	pcb->cwnd = pcb->mss;
darran	0:ac21159e27f4	756	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: cwnd %"U16_F
darran	0:ac21159e27f4	757	" ssthresh %"U16_F"\n",
darran	0:ac21159e27f4	758	pcb->cwnd, pcb->ssthresh));
darran	0:ac21159e27f4	759
darran	0:ac21159e27f4	760	/* The following needs to be called AFTER cwnd is set to one
darran	0:ac21159e27f4	761	mss - STJ */
darran	0:ac21159e27f4	762	tcp_rexmit_rto(pcb);
darran	0:ac21159e27f4	763	}
darran	0:ac21159e27f4	764	}
darran	0:ac21159e27f4	765	}
darran	0:ac21159e27f4	766	/* Check if this PCB has stayed too long in FIN-WAIT-2 */
darran	0:ac21159e27f4	767	if (pcb->state == FIN_WAIT_2) {
darran	0:ac21159e27f4	768	if ((u32_t)(tcp_ticks - pcb->tmr) >
darran	0:ac21159e27f4	769	TCP_FIN_WAIT_TIMEOUT / TCP_SLOW_INTERVAL) {
darran	0:ac21159e27f4	770	++pcb_remove;
darran	0:ac21159e27f4	771	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in FIN-WAIT-2\n"));
darran	0:ac21159e27f4	772	}
darran	0:ac21159e27f4	773	}
darran	0:ac21159e27f4	774
darran	0:ac21159e27f4	775	/* Check if KEEPALIVE should be sent */
darran	0:ac21159e27f4	776	if((pcb->so_options & SOF_KEEPALIVE) &&
darran	0:ac21159e27f4	777	((pcb->state == ESTABLISHED) \|\|
darran	0:ac21159e27f4	778	(pcb->state == CLOSE_WAIT))) {
darran	0:ac21159e27f4	779	#if LWIP_TCP_KEEPALIVE
darran	0:ac21159e27f4	780	if((u32_t)(tcp_ticks - pcb->tmr) >
darran	0:ac21159e27f4	781	(pcb->keep_idle + (pcb->keep_cnt*pcb->keep_intvl))
darran	0:ac21159e27f4	782	/ TCP_SLOW_INTERVAL)
darran	0:ac21159e27f4	783	#else
darran	0:ac21159e27f4	784	if((u32_t)(tcp_ticks - pcb->tmr) >
darran	0:ac21159e27f4	785	(pcb->keep_idle + TCP_MAXIDLE) / TCP_SLOW_INTERVAL)
darran	0:ac21159e27f4	786	#endif /* LWIP_TCP_KEEPALIVE */
darran	0:ac21159e27f4	787	{
darran	0:ac21159e27f4	788	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: KEEPALIVE timeout. Aborting connection to %"U16_F".%"U16_F".%"U16_F".%"U16_F".\n",
darran	0:ac21159e27f4	789	ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip),
darran	0:ac21159e27f4	790	ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip)));
darran	0:ac21159e27f4	791
darran	0:ac21159e27f4	792	++pcb_remove;
darran	0:ac21159e27f4	793	++pcb_reset;
darran	0:ac21159e27f4	794	}
darran	0:ac21159e27f4	795	#if LWIP_TCP_KEEPALIVE
darran	0:ac21159e27f4	796	else if((u32_t)(tcp_ticks - pcb->tmr) >
darran	0:ac21159e27f4	797	(pcb->keep_idle + pcb->keep_cnt_sent * pcb->keep_intvl)
darran	0:ac21159e27f4	798	/ TCP_SLOW_INTERVAL)
darran	0:ac21159e27f4	799	#else
darran	0:ac21159e27f4	800	else if((u32_t)(tcp_ticks - pcb->tmr) >
darran	0:ac21159e27f4	801	(pcb->keep_idle + pcb->keep_cnt_sent * TCP_KEEPINTVL_DEFAULT)
darran	0:ac21159e27f4	802	/ TCP_SLOW_INTERVAL)
darran	0:ac21159e27f4	803	#endif /* LWIP_TCP_KEEPALIVE */
darran	0:ac21159e27f4	804	{
darran	0:ac21159e27f4	805	tcp_keepalive(pcb);
darran	0:ac21159e27f4	806	pcb->keep_cnt_sent++;
darran	0:ac21159e27f4	807	}
darran	0:ac21159e27f4	808	}
darran	0:ac21159e27f4	809
darran	0:ac21159e27f4	810	/* If this PCB has queued out of sequence data, but has been
darran	0:ac21159e27f4	811	inactive for too long, will drop the data (it will eventually
darran	0:ac21159e27f4	812	be retransmitted). */
darran	0:ac21159e27f4	813	#if TCP_QUEUE_OOSEQ
darran	0:ac21159e27f4	814	if (pcb->ooseq != NULL &&
darran	0:ac21159e27f4	815	(u32_t)tcp_ticks - pcb->tmr >= pcb->rto * TCP_OOSEQ_TIMEOUT) {
darran	0:ac21159e27f4	816	tcp_segs_free(pcb->ooseq);
darran	0:ac21159e27f4	817	pcb->ooseq = NULL;
darran	0:ac21159e27f4	818	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: dropping OOSEQ queued data\n"));
darran	0:ac21159e27f4	819	}
darran	0:ac21159e27f4	820	#endif /* TCP_QUEUE_OOSEQ */
darran	0:ac21159e27f4	821
darran	0:ac21159e27f4	822	/* Check if this PCB has stayed too long in SYN-RCVD */
darran	0:ac21159e27f4	823	if (pcb->state == SYN_RCVD) {
darran	0:ac21159e27f4	824	if ((u32_t)(tcp_ticks - pcb->tmr) >
darran	0:ac21159e27f4	825	TCP_SYN_RCVD_TIMEOUT / TCP_SLOW_INTERVAL) {
darran	0:ac21159e27f4	826	++pcb_remove;
darran	0:ac21159e27f4	827	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in SYN-RCVD\n"));
darran	0:ac21159e27f4	828	}
darran	0:ac21159e27f4	829	}
darran	0:ac21159e27f4	830
darran	0:ac21159e27f4	831	/* Check if this PCB has stayed too long in LAST-ACK */
darran	0:ac21159e27f4	832	if (pcb->state == LAST_ACK) {
darran	0:ac21159e27f4	833	if ((u32_t)(tcp_ticks - pcb->tmr) > 2 * TCP_MSL / TCP_SLOW_INTERVAL) {
darran	0:ac21159e27f4	834	++pcb_remove;
darran	0:ac21159e27f4	835	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in LAST-ACK\n"));
darran	0:ac21159e27f4	836	}
darran	0:ac21159e27f4	837	}
darran	0:ac21159e27f4	838
darran	0:ac21159e27f4	839	/* If the PCB should be removed, do it. */
darran	0:ac21159e27f4	840	if (pcb_remove) {
darran	0:ac21159e27f4	841	tcp_pcb_purge(pcb);
darran	0:ac21159e27f4	842	/* Remove PCB from tcp_active_pcbs list. */
darran	0:ac21159e27f4	843	if (prev != NULL) {
darran	0:ac21159e27f4	844	LWIP_ASSERT("tcp_slowtmr: middle tcp != tcp_active_pcbs", pcb != tcp_active_pcbs);
darran	0:ac21159e27f4	845	prev->next = pcb->next;
darran	0:ac21159e27f4	846	} else {
darran	0:ac21159e27f4	847	/* This PCB was the first. */
darran	0:ac21159e27f4	848	LWIP_ASSERT("tcp_slowtmr: first pcb == tcp_active_pcbs", tcp_active_pcbs == pcb);
darran	0:ac21159e27f4	849	tcp_active_pcbs = pcb->next;
darran	0:ac21159e27f4	850	}
darran	0:ac21159e27f4	851
darran	0:ac21159e27f4	852	TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_ABRT);
darran	0:ac21159e27f4	853	if (pcb_reset) {
darran	0:ac21159e27f4	854	tcp_rst(pcb->snd_nxt, pcb->rcv_nxt, &pcb->local_ip, &pcb->remote_ip,
darran	0:ac21159e27f4	855	pcb->local_port, pcb->remote_port);
darran	0:ac21159e27f4	856	}
darran	0:ac21159e27f4	857
darran	0:ac21159e27f4	858	pcb2 = pcb->next;
darran	0:ac21159e27f4	859	memp_free(MEMP_TCP_PCB, pcb);
darran	0:ac21159e27f4	860	pcb = pcb2;
darran	0:ac21159e27f4	861	} else {
darran	0:ac21159e27f4	862	/* get the 'next' element now and work with 'prev' below (in case of abort) */
darran	0:ac21159e27f4	863	prev = pcb;
darran	0:ac21159e27f4	864	pcb = pcb->next;
darran	0:ac21159e27f4	865
darran	0:ac21159e27f4	866	/* We check if we should poll the connection. */
darran	0:ac21159e27f4	867	++prev->polltmr;
darran	0:ac21159e27f4	868	if (prev->polltmr >= prev->pollinterval) {
darran	0:ac21159e27f4	869	prev->polltmr = 0;
darran	0:ac21159e27f4	870	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: polling application\n"));
darran	0:ac21159e27f4	871	TCP_EVENT_POLL(prev, err);
darran	0:ac21159e27f4	872	/* if err == ERR_ABRT, 'prev' is already deallocated */
darran	0:ac21159e27f4	873	if (err == ERR_OK) {
darran	0:ac21159e27f4	874	tcp_output(prev);
darran	0:ac21159e27f4	875	}
darran	0:ac21159e27f4	876	}
darran	0:ac21159e27f4	877	}
darran	0:ac21159e27f4	878	}
darran	0:ac21159e27f4	879
darran	0:ac21159e27f4	880
darran	0:ac21159e27f4	881	/* Steps through all of the TIME-WAIT PCBs. */
darran	0:ac21159e27f4	882	prev = NULL;
darran	0:ac21159e27f4	883	pcb = tcp_tw_pcbs;
darran	0:ac21159e27f4	884	while (pcb != NULL) {
darran	0:ac21159e27f4	885	LWIP_ASSERT("tcp_slowtmr: TIME-WAIT pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
darran	0:ac21159e27f4	886	pcb_remove = 0;
darran	0:ac21159e27f4	887
darran	0:ac21159e27f4	888	/* Check if this PCB has stayed long enough in TIME-WAIT */
darran	0:ac21159e27f4	889	if ((u32_t)(tcp_ticks - pcb->tmr) > 2 * TCP_MSL / TCP_SLOW_INTERVAL) {
darran	0:ac21159e27f4	890	++pcb_remove;
darran	0:ac21159e27f4	891	}
darran	0:ac21159e27f4	892
darran	0:ac21159e27f4	893
darran	0:ac21159e27f4	894
darran	0:ac21159e27f4	895	/* If the PCB should be removed, do it. */
darran	0:ac21159e27f4	896	if (pcb_remove) {
darran	0:ac21159e27f4	897	tcp_pcb_purge(pcb);
darran	0:ac21159e27f4	898	/* Remove PCB from tcp_tw_pcbs list. */
darran	0:ac21159e27f4	899	if (prev != NULL) {
darran	0:ac21159e27f4	900	LWIP_ASSERT("tcp_slowtmr: middle tcp != tcp_tw_pcbs", pcb != tcp_tw_pcbs);
darran	0:ac21159e27f4	901	prev->next = pcb->next;
darran	0:ac21159e27f4	902	} else {
darran	0:ac21159e27f4	903	/* This PCB was the first. */
darran	0:ac21159e27f4	904	LWIP_ASSERT("tcp_slowtmr: first pcb == tcp_tw_pcbs", tcp_tw_pcbs == pcb);
darran	0:ac21159e27f4	905	tcp_tw_pcbs = pcb->next;
darran	0:ac21159e27f4	906	}
darran	0:ac21159e27f4	907	pcb2 = pcb->next;
darran	0:ac21159e27f4	908	memp_free(MEMP_TCP_PCB, pcb);
darran	0:ac21159e27f4	909	pcb = pcb2;
darran	0:ac21159e27f4	910	} else {
darran	0:ac21159e27f4	911	prev = pcb;
darran	0:ac21159e27f4	912	pcb = pcb->next;
darran	0:ac21159e27f4	913	}
darran	0:ac21159e27f4	914	}
darran	0:ac21159e27f4	915	}
darran	0:ac21159e27f4	916
darran	0:ac21159e27f4	917	/**
darran	0:ac21159e27f4	918	* Is called every TCP_FAST_INTERVAL (250 ms) and process data previously
darran	0:ac21159e27f4	919	* "refused" by upper layer (application) and sends delayed ACKs.
darran	0:ac21159e27f4	920	*
darran	0:ac21159e27f4	921	* Automatically called from tcp_tmr().
darran	0:ac21159e27f4	922	*/
darran	0:ac21159e27f4	923	void
darran	0:ac21159e27f4	924	tcp_fasttmr(void)
darran	0:ac21159e27f4	925	{
darran	0:ac21159e27f4	926	struct tcp_pcb *pcb = tcp_active_pcbs;
darran	0:ac21159e27f4	927
darran	0:ac21159e27f4	928	while(pcb != NULL) {
darran	0:ac21159e27f4	929	struct tcp_pcb *next = pcb->next;
darran	0:ac21159e27f4	930	/* If there is data which was previously "refused" by upper layer */
darran	0:ac21159e27f4	931	if (pcb->refused_data != NULL) {
darran	0:ac21159e27f4	932	/* Notify again application with data previously received. */
darran	0:ac21159e27f4	933	err_t err;
darran	0:ac21159e27f4	934	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_fasttmr: notify kept packet\n"));
darran	0:ac21159e27f4	935	TCP_EVENT_RECV(pcb, pcb->refused_data, ERR_OK, err);
darran	0:ac21159e27f4	936	if (err == ERR_OK) {
darran	0:ac21159e27f4	937	pcb->refused_data = NULL;
darran	0:ac21159e27f4	938	} else if (err == ERR_ABRT) {
darran	0:ac21159e27f4	939	/* if err == ERR_ABRT, 'pcb' is already deallocated */
darran	0:ac21159e27f4	940	pcb = NULL;
darran	0:ac21159e27f4	941	}
darran	0:ac21159e27f4	942	}
darran	0:ac21159e27f4	943
darran	0:ac21159e27f4	944	/* send delayed ACKs */
darran	0:ac21159e27f4	945	if (pcb && (pcb->flags & TF_ACK_DELAY)) {
darran	0:ac21159e27f4	946	LWIP_DEBUGF(TCP_DEBUG, ("tcp_fasttmr: delayed ACK\n"));
darran	0:ac21159e27f4	947	tcp_ack_now(pcb);
darran	0:ac21159e27f4	948	tcp_output(pcb);
darran	0:ac21159e27f4	949	pcb->flags &= ~(TF_ACK_DELAY \| TF_ACK_NOW);
darran	0:ac21159e27f4	950	}
darran	0:ac21159e27f4	951
darran	0:ac21159e27f4	952	pcb = next;
darran	0:ac21159e27f4	953	}
darran	0:ac21159e27f4	954	}
darran	0:ac21159e27f4	955
darran	0:ac21159e27f4	956	/**
darran	0:ac21159e27f4	957	* Deallocates a list of TCP segments (tcp_seg structures).
darran	0:ac21159e27f4	958	*
darran	0:ac21159e27f4	959	* @param seg tcp_seg list of TCP segments to free
darran	0:ac21159e27f4	960	*/
darran	0:ac21159e27f4	961	void
darran	0:ac21159e27f4	962	tcp_segs_free(struct tcp_seg *seg)
darran	0:ac21159e27f4	963	{
darran	0:ac21159e27f4	964	while (seg != NULL) {
darran	0:ac21159e27f4	965	struct tcp_seg *next = seg->next;
darran	0:ac21159e27f4	966	tcp_seg_free(seg);
darran	0:ac21159e27f4	967	seg = next;
darran	0:ac21159e27f4	968	}
darran	0:ac21159e27f4	969	}
darran	0:ac21159e27f4	970
darran	0:ac21159e27f4	971	/**
darran	0:ac21159e27f4	972	* Frees a TCP segment (tcp_seg structure).
darran	0:ac21159e27f4	973	*
darran	0:ac21159e27f4	974	* @param seg single tcp_seg to free
darran	0:ac21159e27f4	975	*/
darran	0:ac21159e27f4	976	void
darran	0:ac21159e27f4	977	tcp_seg_free(struct tcp_seg *seg)
darran	0:ac21159e27f4	978	{
darran	0:ac21159e27f4	979	if (seg != NULL) {
darran	0:ac21159e27f4	980	if (seg->p != NULL) {
darran	0:ac21159e27f4	981	pbuf_free(seg->p);
darran	0:ac21159e27f4	982	#if TCP_DEBUG
darran	0:ac21159e27f4	983	seg->p = NULL;
darran	0:ac21159e27f4	984	#endif /* TCP_DEBUG */
darran	0:ac21159e27f4	985	}
darran	0:ac21159e27f4	986	memp_free(MEMP_TCP_SEG, seg);
darran	0:ac21159e27f4	987	}
darran	0:ac21159e27f4	988	}
darran	0:ac21159e27f4	989
darran	0:ac21159e27f4	990	/**
darran	0:ac21159e27f4	991	* Sets the priority of a connection.
darran	0:ac21159e27f4	992	*
darran	0:ac21159e27f4	993	* @param pcb the tcp_pcb to manipulate
darran	0:ac21159e27f4	994	* @param prio new priority
darran	0:ac21159e27f4	995	*/
darran	0:ac21159e27f4	996	void
darran	0:ac21159e27f4	997	tcp_setprio(struct tcp_pcb *pcb, u8_t prio)
darran	0:ac21159e27f4	998	{
darran	0:ac21159e27f4	999	pcb->prio = prio;
darran	0:ac21159e27f4	1000	}
darran	0:ac21159e27f4	1001	#if TCP_QUEUE_OOSEQ
darran	0:ac21159e27f4	1002
darran	0:ac21159e27f4	1003	/**
darran	0:ac21159e27f4	1004	* Returns a copy of the given TCP segment.
darran	0:ac21159e27f4	1005	* The pbuf and data are not copied, only the pointers
darran	0:ac21159e27f4	1006	*
darran	0:ac21159e27f4	1007	* @param seg the old tcp_seg
darran	0:ac21159e27f4	1008	* @return a copy of seg
darran	0:ac21159e27f4	1009	*/
darran	0:ac21159e27f4	1010	struct tcp_seg *
darran	0:ac21159e27f4	1011	tcp_seg_copy(struct tcp_seg *seg)
darran	0:ac21159e27f4	1012	{
darran	0:ac21159e27f4	1013	struct tcp_seg *cseg;
darran	0:ac21159e27f4	1014
darran	0:ac21159e27f4	1015	cseg = (struct tcp_seg *)memp_malloc(MEMP_TCP_SEG);
darran	0:ac21159e27f4	1016	if (cseg == NULL) {
darran	0:ac21159e27f4	1017	return NULL;
darran	0:ac21159e27f4	1018	}
darran	0:ac21159e27f4	1019	SMEMCPY((u8_t )cseg, (const u8_t )seg, sizeof(struct tcp_seg));
darran	0:ac21159e27f4	1020	pbuf_ref(cseg->p);
darran	0:ac21159e27f4	1021	return cseg;
darran	0:ac21159e27f4	1022	}
darran	0:ac21159e27f4	1023	#endif
darran	0:ac21159e27f4	1024
darran	0:ac21159e27f4	1025	#if LWIP_CALLBACK_API
darran	0:ac21159e27f4	1026	/**
darran	0:ac21159e27f4	1027	* Default receive callback that is called if the user didn't register
darran	0:ac21159e27f4	1028	* a recv callback for the pcb.
darran	0:ac21159e27f4	1029	*/
darran	0:ac21159e27f4	1030	err_t
darran	0:ac21159e27f4	1031	tcp_recv_null(void arg, struct tcp_pcb pcb, struct pbuf *p, err_t err)
darran	0:ac21159e27f4	1032	{
darran	0:ac21159e27f4	1033	LWIP_UNUSED_ARG(arg);
darran	0:ac21159e27f4	1034	if (p != NULL) {
darran	0:ac21159e27f4	1035	tcp_recved(pcb, p->tot_len);
darran	0:ac21159e27f4	1036	pbuf_free(p);
darran	0:ac21159e27f4	1037	} else if (err == ERR_OK) {
darran	0:ac21159e27f4	1038	return tcp_close(pcb);
darran	0:ac21159e27f4	1039	}
darran	0:ac21159e27f4	1040	return ERR_OK;
darran	0:ac21159e27f4	1041	}
darran	0:ac21159e27f4	1042	#endif /* LWIP_CALLBACK_API */
darran	0:ac21159e27f4	1043
darran	0:ac21159e27f4	1044	/**
darran	0:ac21159e27f4	1045	* Kills the oldest active connection that has lower priority than prio.
darran	0:ac21159e27f4	1046	*
darran	0:ac21159e27f4	1047	* @param prio minimum priority
darran	0:ac21159e27f4	1048	*/
darran	0:ac21159e27f4	1049	static void
darran	0:ac21159e27f4	1050	tcp_kill_prio(u8_t prio)
darran	0:ac21159e27f4	1051	{
darran	0:ac21159e27f4	1052	struct tcp_pcb pcb, inactive;
darran	0:ac21159e27f4	1053	u32_t inactivity;
darran	0:ac21159e27f4	1054	u8_t mprio;
darran	0:ac21159e27f4	1055
darran	0:ac21159e27f4	1056
darran	0:ac21159e27f4	1057	mprio = TCP_PRIO_MAX;
darran	0:ac21159e27f4	1058
darran	0:ac21159e27f4	1059	/* We kill the oldest active connection that has lower priority than prio. */
darran	0:ac21159e27f4	1060	inactivity = 0;
darran	0:ac21159e27f4	1061	inactive = NULL;
darran	0:ac21159e27f4	1062	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
darran	0:ac21159e27f4	1063	if (pcb->prio <= prio &&
darran	0:ac21159e27f4	1064	pcb->prio <= mprio &&
darran	0:ac21159e27f4	1065	(u32_t)(tcp_ticks - pcb->tmr) >= inactivity) {
darran	0:ac21159e27f4	1066	inactivity = tcp_ticks - pcb->tmr;
darran	0:ac21159e27f4	1067	inactive = pcb;
darran	0:ac21159e27f4	1068	mprio = pcb->prio;
darran	0:ac21159e27f4	1069	}
darran	0:ac21159e27f4	1070	}
darran	0:ac21159e27f4	1071	if (inactive != NULL) {
darran	0:ac21159e27f4	1072	LWIP_DEBUGF(TCP_DEBUG, ("tcp_kill_prio: killing oldest PCB %p (%"S32_F")\n",
darran	0:ac21159e27f4	1073	(void *)inactive, inactivity));
darran	0:ac21159e27f4	1074	tcp_abort(inactive);
darran	0:ac21159e27f4	1075	}
darran	0:ac21159e27f4	1076	}
darran	0:ac21159e27f4	1077
darran	0:ac21159e27f4	1078	/**
darran	0:ac21159e27f4	1079	* Kills the oldest connection that is in TIME_WAIT state.
darran	0:ac21159e27f4	1080	* Called from tcp_alloc() if no more connections are available.
darran	0:ac21159e27f4	1081	*/
darran	0:ac21159e27f4	1082	static void
darran	0:ac21159e27f4	1083	tcp_kill_timewait(void)
darran	0:ac21159e27f4	1084	{
darran	0:ac21159e27f4	1085	struct tcp_pcb pcb, inactive;
darran	0:ac21159e27f4	1086	u32_t inactivity;
darran	0:ac21159e27f4	1087
darran	0:ac21159e27f4	1088	inactivity = 0;
darran	0:ac21159e27f4	1089	inactive = NULL;
darran	0:ac21159e27f4	1090	/* Go through the list of TIME_WAIT pcbs and get the oldest pcb. */
darran	0:ac21159e27f4	1091	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
darran	0:ac21159e27f4	1092	if ((u32_t)(tcp_ticks - pcb->tmr) >= inactivity) {
darran	0:ac21159e27f4	1093	inactivity = tcp_ticks - pcb->tmr;
darran	0:ac21159e27f4	1094	inactive = pcb;
darran	0:ac21159e27f4	1095	}
darran	0:ac21159e27f4	1096	}
darran	0:ac21159e27f4	1097	if (inactive != NULL) {
darran	0:ac21159e27f4	1098	LWIP_DEBUGF(TCP_DEBUG, ("tcp_kill_timewait: killing oldest TIME-WAIT PCB %p (%"S32_F")\n",
darran	0:ac21159e27f4	1099	(void *)inactive, inactivity));
darran	0:ac21159e27f4	1100	tcp_abort(inactive);
darran	0:ac21159e27f4	1101	}
darran	0:ac21159e27f4	1102	}
darran	0:ac21159e27f4	1103
darran	0:ac21159e27f4	1104	/**
darran	0:ac21159e27f4	1105	* Allocate a new tcp_pcb structure.
darran	0:ac21159e27f4	1106	*
darran	0:ac21159e27f4	1107	* @param prio priority for the new pcb
darran	0:ac21159e27f4	1108	* @return a new tcp_pcb that initially is in state CLOSED
darran	0:ac21159e27f4	1109	*/
darran	0:ac21159e27f4	1110	struct tcp_pcb *
darran	0:ac21159e27f4	1111	tcp_alloc(u8_t prio)
darran	0:ac21159e27f4	1112	{
darran	0:ac21159e27f4	1113	struct tcp_pcb *pcb;
darran	0:ac21159e27f4	1114	u32_t iss;
darran	0:ac21159e27f4	1115
darran	0:ac21159e27f4	1116	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
darran	0:ac21159e27f4	1117	if (pcb == NULL) {
darran	0:ac21159e27f4	1118	/* Try killing oldest connection in TIME-WAIT. */
darran	0:ac21159e27f4	1119	LWIP_DEBUGF(TCP_DEBUG, ("tcp_alloc: killing off oldest TIME-WAIT connection\n"));
darran	0:ac21159e27f4	1120	tcp_kill_timewait();
darran	0:ac21159e27f4	1121	/* Try to allocate a tcp_pcb again. */
darran	0:ac21159e27f4	1122	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
darran	0:ac21159e27f4	1123	if (pcb == NULL) {
darran	0:ac21159e27f4	1124	/* Try killing active connections with lower priority than the new one. */
darran	0:ac21159e27f4	1125	LWIP_DEBUGF(TCP_DEBUG, ("tcp_alloc: killing connection with prio lower than %d\n", prio));
darran	0:ac21159e27f4	1126	tcp_kill_prio(prio);
darran	0:ac21159e27f4	1127	/* Try to allocate a tcp_pcb again. */
darran	0:ac21159e27f4	1128	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
darran	0:ac21159e27f4	1129	if (pcb != NULL) {
darran	0:ac21159e27f4	1130	/* adjust err stats: memp_malloc failed twice before */
darran	0:ac21159e27f4	1131	MEMP_STATS_DEC(err, MEMP_TCP_PCB);
darran	0:ac21159e27f4	1132	}
darran	0:ac21159e27f4	1133	}
darran	0:ac21159e27f4	1134	if (pcb != NULL) {
darran	0:ac21159e27f4	1135	/* adjust err stats: timewait PCB was freed above */
darran	0:ac21159e27f4	1136	MEMP_STATS_DEC(err, MEMP_TCP_PCB);
darran	0:ac21159e27f4	1137	}
darran	0:ac21159e27f4	1138	}
darran	0:ac21159e27f4	1139	if (pcb != NULL) {
darran	0:ac21159e27f4	1140	memset(pcb, 0, sizeof(struct tcp_pcb));
darran	0:ac21159e27f4	1141	pcb->prio = prio;
darran	0:ac21159e27f4	1142	pcb->snd_buf = TCP_SND_BUF;
darran	0:ac21159e27f4	1143	pcb->snd_queuelen = 0;
darran	0:ac21159e27f4	1144	pcb->rcv_wnd = TCP_WND;
darran	0:ac21159e27f4	1145	pcb->rcv_ann_wnd = TCP_WND;
darran	0:ac21159e27f4	1146	pcb->tos = 0;
darran	0:ac21159e27f4	1147	pcb->ttl = TCP_TTL;
darran	0:ac21159e27f4	1148	/* As initial send MSS, we use TCP_MSS but limit it to 536.
darran	0:ac21159e27f4	1149	The send MSS is updated when an MSS option is received. */
darran	0:ac21159e27f4	1150	pcb->mss = (TCP_MSS > 536) ? 536 : TCP_MSS;
darran	0:ac21159e27f4	1151	pcb->rto = 3000 / TCP_SLOW_INTERVAL;
darran	0:ac21159e27f4	1152	pcb->sa = 0;
darran	0:ac21159e27f4	1153	pcb->sv = 3000 / TCP_SLOW_INTERVAL;
darran	0:ac21159e27f4	1154	pcb->rtime = -1;
darran	0:ac21159e27f4	1155	pcb->cwnd = 1;
darran	0:ac21159e27f4	1156	iss = tcp_next_iss();
darran	0:ac21159e27f4	1157	pcb->snd_wl2 = iss;
darran	0:ac21159e27f4	1158	pcb->snd_nxt = iss;
darran	0:ac21159e27f4	1159	pcb->lastack = iss;
darran	0:ac21159e27f4	1160	pcb->snd_lbb = iss;
darran	0:ac21159e27f4	1161	pcb->tmr = tcp_ticks;
darran	0:ac21159e27f4	1162
darran	0:ac21159e27f4	1163	pcb->polltmr = 0;
darran	0:ac21159e27f4	1164
darran	0:ac21159e27f4	1165	#if LWIP_CALLBACK_API
darran	0:ac21159e27f4	1166	pcb->recv = tcp_recv_null;
darran	0:ac21159e27f4	1167	#endif /* LWIP_CALLBACK_API */
darran	0:ac21159e27f4	1168
darran	0:ac21159e27f4	1169	/* Init KEEPALIVE timer */
darran	0:ac21159e27f4	1170	pcb->keep_idle = TCP_KEEPIDLE_DEFAULT;
darran	0:ac21159e27f4	1171
darran	0:ac21159e27f4	1172	#if LWIP_TCP_KEEPALIVE
darran	0:ac21159e27f4	1173	pcb->keep_intvl = TCP_KEEPINTVL_DEFAULT;
darran	0:ac21159e27f4	1174	pcb->keep_cnt = TCP_KEEPCNT_DEFAULT;
darran	0:ac21159e27f4	1175	#endif /* LWIP_TCP_KEEPALIVE */
darran	0:ac21159e27f4	1176
darran	0:ac21159e27f4	1177	pcb->keep_cnt_sent = 0;
darran	0:ac21159e27f4	1178	}
darran	0:ac21159e27f4	1179	return pcb;
darran	0:ac21159e27f4	1180	}
darran	0:ac21159e27f4	1181
darran	0:ac21159e27f4	1182	/**
darran	0:ac21159e27f4	1183	* Creates a new TCP protocol control block but doesn't place it on
darran	0:ac21159e27f4	1184	* any of the TCP PCB lists.
darran	0:ac21159e27f4	1185	* The pcb is not put on any list until binding using tcp_bind().
darran	0:ac21159e27f4	1186	*
darran	0:ac21159e27f4	1187	* @internal: Maybe there should be a idle TCP PCB list where these
darran	0:ac21159e27f4	1188	* PCBs are put on. Port reservation using tcp_bind() is implemented but
darran	0:ac21159e27f4	1189	* allocated pcbs that are not bound can't be killed automatically if wanting
darran	0:ac21159e27f4	1190	* to allocate a pcb with higher prio (@see tcp_kill_prio())
darran	0:ac21159e27f4	1191	*
darran	0:ac21159e27f4	1192	* @return a new tcp_pcb that initially is in state CLOSED
darran	0:ac21159e27f4	1193	*/
darran	0:ac21159e27f4	1194	struct tcp_pcb *
darran	0:ac21159e27f4	1195	tcp_new(void)
darran	0:ac21159e27f4	1196	{
darran	0:ac21159e27f4	1197	return tcp_alloc(TCP_PRIO_NORMAL);
darran	0:ac21159e27f4	1198	}
darran	0:ac21159e27f4	1199
darran	0:ac21159e27f4	1200	/**
darran	0:ac21159e27f4	1201	* Used to specify the argument that should be passed callback
darran	0:ac21159e27f4	1202	* functions.
darran	0:ac21159e27f4	1203	*
darran	0:ac21159e27f4	1204	* @param pcb tcp_pcb to set the callback argument
darran	0:ac21159e27f4	1205	* @param arg void pointer argument to pass to callback functions
darran	0:ac21159e27f4	1206	*/
darran	0:ac21159e27f4	1207	void
darran	0:ac21159e27f4	1208	tcp_arg(struct tcp_pcb pcb, void arg)
darran	0:ac21159e27f4	1209	{
darran	0:ac21159e27f4	1210	pcb->callback_arg = arg;
darran	0:ac21159e27f4	1211	}
darran	0:ac21159e27f4	1212	#if LWIP_CALLBACK_API
darran	0:ac21159e27f4	1213
darran	0:ac21159e27f4	1214	/**
darran	0:ac21159e27f4	1215	* Used to specify the function that should be called when a TCP
darran	0:ac21159e27f4	1216	* connection receives data.
darran	0:ac21159e27f4	1217	*
darran	0:ac21159e27f4	1218	* @param pcb tcp_pcb to set the recv callback
darran	0:ac21159e27f4	1219	* @param recv callback function to call for this pcb when data is received
darran	0:ac21159e27f4	1220	*/
darran	0:ac21159e27f4	1221	void
darran	0:ac21159e27f4	1222	tcp_recv(struct tcp_pcb *pcb, tcp_recv_fn recv)
darran	0:ac21159e27f4	1223	{
darran	0:ac21159e27f4	1224	pcb->recv = recv;
darran	0:ac21159e27f4	1225	}
darran	0:ac21159e27f4	1226
darran	0:ac21159e27f4	1227	/**
darran	0:ac21159e27f4	1228	* Used to specify the function that should be called when TCP data
darran	0:ac21159e27f4	1229	* has been successfully delivered to the remote host.
darran	0:ac21159e27f4	1230	*
darran	0:ac21159e27f4	1231	* @param pcb tcp_pcb to set the sent callback
darran	0:ac21159e27f4	1232	* @param sent callback function to call for this pcb when data is successfully sent
darran	0:ac21159e27f4	1233	*/
darran	0:ac21159e27f4	1234	void
darran	0:ac21159e27f4	1235	tcp_sent(struct tcp_pcb *pcb, tcp_sent_fn sent)
darran	0:ac21159e27f4	1236	{
darran	0:ac21159e27f4	1237	pcb->sent = sent;
darran	0:ac21159e27f4	1238	}
darran	0:ac21159e27f4	1239
darran	0:ac21159e27f4	1240	/**
darran	0:ac21159e27f4	1241	* Used to specify the function that should be called when a fatal error
darran	0:ac21159e27f4	1242	* has occured on the connection.
darran	0:ac21159e27f4	1243	*
darran	0:ac21159e27f4	1244	* @param pcb tcp_pcb to set the err callback
darran	0:ac21159e27f4	1245	* @param err callback function to call for this pcb when a fatal error
darran	0:ac21159e27f4	1246	* has occured on the connection
darran	0:ac21159e27f4	1247	*/
darran	0:ac21159e27f4	1248	void
darran	0:ac21159e27f4	1249	tcp_err(struct tcp_pcb *pcb, tcp_err_fn err)
darran	0:ac21159e27f4	1250	{
darran	0:ac21159e27f4	1251	pcb->errf = err;
darran	0:ac21159e27f4	1252	}
darran	0:ac21159e27f4	1253
darran	0:ac21159e27f4	1254	/**
darran	0:ac21159e27f4	1255	* Used for specifying the function that should be called when a
darran	0:ac21159e27f4	1256	* LISTENing connection has been connected to another host.
darran	0:ac21159e27f4	1257	*
darran	0:ac21159e27f4	1258	* @param pcb tcp_pcb to set the accept callback
darran	0:ac21159e27f4	1259	* @param accept callback function to call for this pcb when LISTENing
darran	0:ac21159e27f4	1260	* connection has been connected to another host
darran	0:ac21159e27f4	1261	*/
darran	0:ac21159e27f4	1262	void
darran	0:ac21159e27f4	1263	tcp_accept(struct tcp_pcb *pcb, tcp_accept_fn accept)
darran	0:ac21159e27f4	1264	{
darran	0:ac21159e27f4	1265	pcb->accept = accept;
darran	0:ac21159e27f4	1266	}
darran	0:ac21159e27f4	1267	#endif /* LWIP_CALLBACK_API */
darran	0:ac21159e27f4	1268
darran	0:ac21159e27f4	1269
darran	0:ac21159e27f4	1270	/**
darran	0:ac21159e27f4	1271	* Used to specify the function that should be called periodically
darran	0:ac21159e27f4	1272	* from TCP. The interval is specified in terms of the TCP coarse
darran	0:ac21159e27f4	1273	* timer interval, which is called twice a second.
darran	0:ac21159e27f4	1274	*
darran	0:ac21159e27f4	1275	*/
darran	0:ac21159e27f4	1276	void
darran	0:ac21159e27f4	1277	tcp_poll(struct tcp_pcb *pcb, tcp_poll_fn poll, u8_t interval)
darran	0:ac21159e27f4	1278	{
darran	0:ac21159e27f4	1279	#if LWIP_CALLBACK_API
darran	0:ac21159e27f4	1280	pcb->poll = poll;
darran	0:ac21159e27f4	1281	#endif /* LWIP_CALLBACK_API */
darran	0:ac21159e27f4	1282	pcb->pollinterval = interval;
darran	0:ac21159e27f4	1283	}
darran	0:ac21159e27f4	1284
darran	0:ac21159e27f4	1285	/**
darran	0:ac21159e27f4	1286	* Purges a TCP PCB. Removes any buffered data and frees the buffer memory
darran	0:ac21159e27f4	1287	* (pcb->ooseq, pcb->unsent and pcb->unacked are freed).
darran	0:ac21159e27f4	1288	*
darran	0:ac21159e27f4	1289	* @param pcb tcp_pcb to purge. The pcb itself is not deallocated!
darran	0:ac21159e27f4	1290	*/
darran	0:ac21159e27f4	1291	void
darran	0:ac21159e27f4	1292	tcp_pcb_purge(struct tcp_pcb *pcb)
darran	0:ac21159e27f4	1293	{
darran	0:ac21159e27f4	1294	if (pcb->state != CLOSED &&
darran	0:ac21159e27f4	1295	pcb->state != TIME_WAIT &&
darran	0:ac21159e27f4	1296	pcb->state != LISTEN) {
darran	0:ac21159e27f4	1297
darran	0:ac21159e27f4	1298	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge\n"));
darran	0:ac21159e27f4	1299
darran	0:ac21159e27f4	1300	#if TCP_LISTEN_BACKLOG
darran	0:ac21159e27f4	1301	if (pcb->state == SYN_RCVD) {
darran	0:ac21159e27f4	1302	/* Need to find the corresponding listen_pcb and decrease its accepts_pending */
darran	0:ac21159e27f4	1303	struct tcp_pcb_listen *lpcb;
darran	0:ac21159e27f4	1304	LWIP_ASSERT("tcp_pcb_purge: pcb->state == SYN_RCVD but tcp_listen_pcbs is NULL",
darran	0:ac21159e27f4	1305	tcp_listen_pcbs.listen_pcbs != NULL);
darran	0:ac21159e27f4	1306	for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
darran	0:ac21159e27f4	1307	if ((lpcb->local_port == pcb->local_port) &&
darran	0:ac21159e27f4	1308	(ip_addr_isany(&lpcb->local_ip) \|\|
darran	0:ac21159e27f4	1309	ip_addr_cmp(&pcb->local_ip, &lpcb->local_ip))) {
darran	0:ac21159e27f4	1310	/* port and address of the listen pcb match the timed-out pcb */
darran	0:ac21159e27f4	1311	LWIP_ASSERT("tcp_pcb_purge: listen pcb does not have accepts pending",
darran	0:ac21159e27f4	1312	lpcb->accepts_pending > 0);
darran	0:ac21159e27f4	1313	lpcb->accepts_pending--;
darran	0:ac21159e27f4	1314	break;
darran	0:ac21159e27f4	1315	}
darran	0:ac21159e27f4	1316	}
darran	0:ac21159e27f4	1317	}
darran	0:ac21159e27f4	1318	#endif /* TCP_LISTEN_BACKLOG */
darran	0:ac21159e27f4	1319
darran	0:ac21159e27f4	1320
darran	0:ac21159e27f4	1321	if (pcb->refused_data != NULL) {
darran	0:ac21159e27f4	1322	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->refused_data\n"));
darran	0:ac21159e27f4	1323	pbuf_free(pcb->refused_data);
darran	0:ac21159e27f4	1324	pcb->refused_data = NULL;
darran	0:ac21159e27f4	1325	}
darran	0:ac21159e27f4	1326	if (pcb->unsent != NULL) {
darran	0:ac21159e27f4	1327	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: not all data sent\n"));
darran	0:ac21159e27f4	1328	}
darran	0:ac21159e27f4	1329	if (pcb->unacked != NULL) {
darran	0:ac21159e27f4	1330	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->unacked\n"));
darran	0:ac21159e27f4	1331	}
darran	0:ac21159e27f4	1332	#if TCP_QUEUE_OOSEQ /* LW */
darran	0:ac21159e27f4	1333	if (pcb->ooseq != NULL) {
darran	0:ac21159e27f4	1334	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->ooseq\n"));
darran	0:ac21159e27f4	1335	}
darran	0:ac21159e27f4	1336	tcp_segs_free(pcb->ooseq);
darran	0:ac21159e27f4	1337	pcb->ooseq = NULL;
darran	0:ac21159e27f4	1338	#endif /* TCP_QUEUE_OOSEQ */
darran	0:ac21159e27f4	1339
darran	0:ac21159e27f4	1340	/* Stop the retransmission timer as it will expect data on unacked
darran	0:ac21159e27f4	1341	queue if it fires */
darran	0:ac21159e27f4	1342	pcb->rtime = -1;
darran	0:ac21159e27f4	1343
darran	0:ac21159e27f4	1344	tcp_segs_free(pcb->unsent);
darran	0:ac21159e27f4	1345	tcp_segs_free(pcb->unacked);
darran	0:ac21159e27f4	1346	pcb->unacked = pcb->unsent = NULL;
darran	0:ac21159e27f4	1347	#if TCP_OVERSIZE
darran	0:ac21159e27f4	1348	pcb->unsent_oversize = 0;
darran	0:ac21159e27f4	1349	#endif /* TCP_OVERSIZE */
darran	0:ac21159e27f4	1350	}
darran	0:ac21159e27f4	1351	}
darran	0:ac21159e27f4	1352
darran	0:ac21159e27f4	1353	/**
darran	0:ac21159e27f4	1354	* Purges the PCB and removes it from a PCB list. Any delayed ACKs are sent first.
darran	0:ac21159e27f4	1355	*
darran	0:ac21159e27f4	1356	* @param pcblist PCB list to purge.
darran	0:ac21159e27f4	1357	* @param pcb tcp_pcb to purge. The pcb itself is NOT deallocated!
darran	0:ac21159e27f4	1358	*/
darran	0:ac21159e27f4	1359	void
darran	0:ac21159e27f4	1360	tcp_pcb_remove(struct tcp_pcb *pcblist, struct tcp_pcb pcb)
darran	0:ac21159e27f4	1361	{
darran	0:ac21159e27f4	1362	TCP_RMV(pcblist, pcb);
darran	0:ac21159e27f4	1363
darran	0:ac21159e27f4	1364	tcp_pcb_purge(pcb);
darran	0:ac21159e27f4	1365
darran	0:ac21159e27f4	1366	/* if there is an outstanding delayed ACKs, send it */
darran	0:ac21159e27f4	1367	if (pcb->state != TIME_WAIT &&
darran	0:ac21159e27f4	1368	pcb->state != LISTEN &&
darran	0:ac21159e27f4	1369	pcb->flags & TF_ACK_DELAY) {
darran	0:ac21159e27f4	1370	pcb->flags \|= TF_ACK_NOW;
darran	0:ac21159e27f4	1371	tcp_output(pcb);
darran	0:ac21159e27f4	1372	}
darran	0:ac21159e27f4	1373
darran	0:ac21159e27f4	1374	if (pcb->state != LISTEN) {
darran	0:ac21159e27f4	1375	LWIP_ASSERT("unsent segments leaking", pcb->unsent == NULL);
darran	0:ac21159e27f4	1376	LWIP_ASSERT("unacked segments leaking", pcb->unacked == NULL);
darran	0:ac21159e27f4	1377	#if TCP_QUEUE_OOSEQ
darran	0:ac21159e27f4	1378	LWIP_ASSERT("ooseq segments leaking", pcb->ooseq == NULL);
darran	0:ac21159e27f4	1379	#endif /* TCP_QUEUE_OOSEQ */
darran	0:ac21159e27f4	1380	}
darran	0:ac21159e27f4	1381
darran	0:ac21159e27f4	1382	pcb->state = CLOSED;
darran	0:ac21159e27f4	1383
darran	0:ac21159e27f4	1384	LWIP_ASSERT("tcp_pcb_remove: tcp_pcbs_sane()", tcp_pcbs_sane());
darran	0:ac21159e27f4	1385	}
darran	0:ac21159e27f4	1386
darran	0:ac21159e27f4	1387	/**
darran	0:ac21159e27f4	1388	* Calculates a new initial sequence number for new connections.
darran	0:ac21159e27f4	1389	*
darran	0:ac21159e27f4	1390	* @return u32_t pseudo random sequence number
darran	0:ac21159e27f4	1391	*/
darran	0:ac21159e27f4	1392	u32_t
darran	0:ac21159e27f4	1393	tcp_next_iss(void)
darran	0:ac21159e27f4	1394	{
darran	0:ac21159e27f4	1395	static u32_t iss = 6510;
darran	0:ac21159e27f4	1396
darran	0:ac21159e27f4	1397	iss += tcp_ticks; /* XXX */
darran	0:ac21159e27f4	1398	return iss;
darran	0:ac21159e27f4	1399	}
darran	0:ac21159e27f4	1400
darran	0:ac21159e27f4	1401	#if TCP_CALCULATE_EFF_SEND_MSS
darran	0:ac21159e27f4	1402	/**
darran	0:ac21159e27f4	1403	* Calcluates the effective send mss that can be used for a specific IP address
darran	0:ac21159e27f4	1404	* by using ip_route to determin the netif used to send to the address and
darran	0:ac21159e27f4	1405	* calculating the minimum of TCP_MSS and that netif's mtu (if set).
darran	0:ac21159e27f4	1406	*/
darran	0:ac21159e27f4	1407	u16_t
darran	0:ac21159e27f4	1408	tcp_eff_send_mss(u16_t sendmss, ip_addr_t *addr)
darran	0:ac21159e27f4	1409	{
darran	0:ac21159e27f4	1410	u16_t mss_s;
darran	0:ac21159e27f4	1411	struct netif *outif;
darran	0:ac21159e27f4	1412
darran	0:ac21159e27f4	1413	outif = ip_route(addr);
darran	0:ac21159e27f4	1414	if ((outif != NULL) && (outif->mtu != 0)) {
darran	0:ac21159e27f4	1415	mss_s = outif->mtu - IP_HLEN - TCP_HLEN;
darran	0:ac21159e27f4	1416	/* RFC 1122, chap 4.2.2.6:
darran	0:ac21159e27f4	1417	* Eff.snd.MSS = min(SendMSS+20, MMS_S) - TCPhdrsize - IPoptionsize
darran	0:ac21159e27f4	1418	* We correct for TCP options in tcp_write(), and don't support IP options.
darran	0:ac21159e27f4	1419	*/
darran	0:ac21159e27f4	1420	sendmss = LWIP_MIN(sendmss, mss_s);
darran	0:ac21159e27f4	1421	}
darran	0:ac21159e27f4	1422	return sendmss;
darran	0:ac21159e27f4	1423	}
darran	0:ac21159e27f4	1424	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
darran	0:ac21159e27f4	1425
darran	0:ac21159e27f4	1426	const char*
darran	0:ac21159e27f4	1427	tcp_debug_state_str(enum tcp_state s)
darran	0:ac21159e27f4	1428	{
darran	0:ac21159e27f4	1429	return tcp_state_str[s];
darran	0:ac21159e27f4	1430	}
darran	0:ac21159e27f4	1431
darran	0:ac21159e27f4	1432	#if TCP_DEBUG \|\| TCP_INPUT_DEBUG \|\| TCP_OUTPUT_DEBUG
darran	0:ac21159e27f4	1433	/**
darran	0:ac21159e27f4	1434	* Print a tcp header for debugging purposes.
darran	0:ac21159e27f4	1435	*
darran	0:ac21159e27f4	1436	* @param tcphdr pointer to a struct tcp_hdr
darran	0:ac21159e27f4	1437	*/
darran	0:ac21159e27f4	1438	void
darran	0:ac21159e27f4	1439	tcp_debug_print(struct tcp_hdr *tcphdr)
darran	0:ac21159e27f4	1440	{
darran	0:ac21159e27f4	1441	LWIP_DEBUGF(TCP_DEBUG, ("TCP header:\n"));
darran	0:ac21159e27f4	1442	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
darran	0:ac21159e27f4	1443	LWIP_DEBUGF(TCP_DEBUG, ("\| %5"U16_F" \| %5"U16_F" \| (src port, dest port)\n",
darran	0:ac21159e27f4	1444	ntohs(tcphdr->src), ntohs(tcphdr->dest)));
darran	0:ac21159e27f4	1445	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
darran	0:ac21159e27f4	1446	LWIP_DEBUGF(TCP_DEBUG, ("\| %010"U32_F" \| (seq no)\n",
darran	0:ac21159e27f4	1447	ntohl(tcphdr->seqno)));
darran	0:ac21159e27f4	1448	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
darran	0:ac21159e27f4	1449	LWIP_DEBUGF(TCP_DEBUG, ("\| %010"U32_F" \| (ack no)\n",
darran	0:ac21159e27f4	1450	ntohl(tcphdr->ackno)));
darran	0:ac21159e27f4	1451	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
darran	0:ac21159e27f4	1452	LWIP_DEBUGF(TCP_DEBUG, ("\| %2"U16_F" \| \|%"U16_F"%"U16_F"%"U16_F"%"U16_F"%"U16_F"%"U16_F"\| %5"U16_F" \| (hdrlen, flags (",
darran	0:ac21159e27f4	1453	TCPH_HDRLEN(tcphdr),
darran	0:ac21159e27f4	1454	TCPH_FLAGS(tcphdr) >> 5 & 1,
darran	0:ac21159e27f4	1455	TCPH_FLAGS(tcphdr) >> 4 & 1,
darran	0:ac21159e27f4	1456	TCPH_FLAGS(tcphdr) >> 3 & 1,
darran	0:ac21159e27f4	1457	TCPH_FLAGS(tcphdr) >> 2 & 1,
darran	0:ac21159e27f4	1458	TCPH_FLAGS(tcphdr) >> 1 & 1,
darran	0:ac21159e27f4	1459	TCPH_FLAGS(tcphdr) & 1,
darran	0:ac21159e27f4	1460	ntohs(tcphdr->wnd)));
darran	0:ac21159e27f4	1461	tcp_debug_print_flags(TCPH_FLAGS(tcphdr));
darran	0:ac21159e27f4	1462	LWIP_DEBUGF(TCP_DEBUG, ("), win)\n"));
darran	0:ac21159e27f4	1463	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
darran	0:ac21159e27f4	1464	LWIP_DEBUGF(TCP_DEBUG, ("\| 0x%04"X16_F" \| %5"U16_F" \| (chksum, urgp)\n",
darran	0:ac21159e27f4	1465	ntohs(tcphdr->chksum), ntohs(tcphdr->urgp)));
darran	0:ac21159e27f4	1466	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
darran	0:ac21159e27f4	1467	}
darran	0:ac21159e27f4	1468
darran	0:ac21159e27f4	1469	/**
darran	0:ac21159e27f4	1470	* Print a tcp state for debugging purposes.
darran	0:ac21159e27f4	1471	*
darran	0:ac21159e27f4	1472	* @param s enum tcp_state to print
darran	0:ac21159e27f4	1473	*/
darran	0:ac21159e27f4	1474	void
darran	0:ac21159e27f4	1475	tcp_debug_print_state(enum tcp_state s)
darran	0:ac21159e27f4	1476	{
darran	0:ac21159e27f4	1477	LWIP_DEBUGF(TCP_DEBUG, ("State: %s\n", tcp_state_str[s]));
darran	0:ac21159e27f4	1478	}
darran	0:ac21159e27f4	1479
darran	0:ac21159e27f4	1480	/**
darran	0:ac21159e27f4	1481	* Print tcp flags for debugging purposes.
darran	0:ac21159e27f4	1482	*
darran	0:ac21159e27f4	1483	* @param flags tcp flags, all active flags are printed
darran	0:ac21159e27f4	1484	*/
darran	0:ac21159e27f4	1485	void
darran	0:ac21159e27f4	1486	tcp_debug_print_flags(u8_t flags)
darran	0:ac21159e27f4	1487	{
darran	0:ac21159e27f4	1488	if (flags & TCP_FIN) {
darran	0:ac21159e27f4	1489	LWIP_DEBUGF(TCP_DEBUG, ("FIN "));
darran	0:ac21159e27f4	1490	}
darran	0:ac21159e27f4	1491	if (flags & TCP_SYN) {
darran	0:ac21159e27f4	1492	LWIP_DEBUGF(TCP_DEBUG, ("SYN "));
darran	0:ac21159e27f4	1493	}
darran	0:ac21159e27f4	1494	if (flags & TCP_RST) {
darran	0:ac21159e27f4	1495	LWIP_DEBUGF(TCP_DEBUG, ("RST "));
darran	0:ac21159e27f4	1496	}
darran	0:ac21159e27f4	1497	if (flags & TCP_PSH) {
darran	0:ac21159e27f4	1498	LWIP_DEBUGF(TCP_DEBUG, ("PSH "));
darran	0:ac21159e27f4	1499	}
darran	0:ac21159e27f4	1500	if (flags & TCP_ACK) {
darran	0:ac21159e27f4	1501	LWIP_DEBUGF(TCP_DEBUG, ("ACK "));
darran	0:ac21159e27f4	1502	}
darran	0:ac21159e27f4	1503	if (flags & TCP_URG) {
darran	0:ac21159e27f4	1504	LWIP_DEBUGF(TCP_DEBUG, ("URG "));
darran	0:ac21159e27f4	1505	}
darran	0:ac21159e27f4	1506	if (flags & TCP_ECE) {
darran	0:ac21159e27f4	1507	LWIP_DEBUGF(TCP_DEBUG, ("ECE "));
darran	0:ac21159e27f4	1508	}
darran	0:ac21159e27f4	1509	if (flags & TCP_CWR) {
darran	0:ac21159e27f4	1510	LWIP_DEBUGF(TCP_DEBUG, ("CWR "));
darran	0:ac21159e27f4	1511	}
darran	0:ac21159e27f4	1512	LWIP_DEBUGF(TCP_DEBUG, ("\n"));
darran	0:ac21159e27f4	1513	}
darran	0:ac21159e27f4	1514
darran	0:ac21159e27f4	1515	/**
darran	0:ac21159e27f4	1516	* Print all tcp_pcbs in every list for debugging purposes.
darran	0:ac21159e27f4	1517	*/
darran	0:ac21159e27f4	1518	void
darran	0:ac21159e27f4	1519	tcp_debug_print_pcbs(void)
darran	0:ac21159e27f4	1520	{
darran	0:ac21159e27f4	1521	struct tcp_pcb *pcb;
darran	0:ac21159e27f4	1522	LWIP_DEBUGF(TCP_DEBUG, ("Active PCB states:\n"));
darran	0:ac21159e27f4	1523	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
darran	0:ac21159e27f4	1524	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
darran	0:ac21159e27f4	1525	pcb->local_port, pcb->remote_port,
darran	0:ac21159e27f4	1526	pcb->snd_nxt, pcb->rcv_nxt));
darran	0:ac21159e27f4	1527	tcp_debug_print_state(pcb->state);
darran	0:ac21159e27f4	1528	}
darran	0:ac21159e27f4	1529	LWIP_DEBUGF(TCP_DEBUG, ("Listen PCB states:\n"));
darran	0:ac21159e27f4	1530	for(pcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs; pcb != NULL; pcb = pcb->next) {
darran	0:ac21159e27f4	1531	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
darran	0:ac21159e27f4	1532	pcb->local_port, pcb->remote_port,
darran	0:ac21159e27f4	1533	pcb->snd_nxt, pcb->rcv_nxt));
darran	0:ac21159e27f4	1534	tcp_debug_print_state(pcb->state);
darran	0:ac21159e27f4	1535	}
darran	0:ac21159e27f4	1536	LWIP_DEBUGF(TCP_DEBUG, ("TIME-WAIT PCB states:\n"));
darran	0:ac21159e27f4	1537	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
darran	0:ac21159e27f4	1538	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
darran	0:ac21159e27f4	1539	pcb->local_port, pcb->remote_port,
darran	0:ac21159e27f4	1540	pcb->snd_nxt, pcb->rcv_nxt));
darran	0:ac21159e27f4	1541	tcp_debug_print_state(pcb->state);
darran	0:ac21159e27f4	1542	}
darran	0:ac21159e27f4	1543	}
darran	0:ac21159e27f4	1544
darran	0:ac21159e27f4	1545	/**
darran	0:ac21159e27f4	1546	* Check state consistency of the tcp_pcb lists.
darran	0:ac21159e27f4	1547	*/
darran	0:ac21159e27f4	1548	s16_t
darran	0:ac21159e27f4	1549	tcp_pcbs_sane(void)
darran	0:ac21159e27f4	1550	{
darran	0:ac21159e27f4	1551	struct tcp_pcb *pcb;
darran	0:ac21159e27f4	1552	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
darran	0:ac21159e27f4	1553	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != CLOSED", pcb->state != CLOSED);
darran	0:ac21159e27f4	1554	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != LISTEN", pcb->state != LISTEN);
darran	0:ac21159e27f4	1555	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT);
darran	0:ac21159e27f4	1556	}
darran	0:ac21159e27f4	1557	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
darran	0:ac21159e27f4	1558	LWIP_ASSERT("tcp_pcbs_sane: tw pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
darran	0:ac21159e27f4	1559	}
darran	0:ac21159e27f4	1560	return 1;
darran	0:ac21159e27f4	1561	}
darran	0:ac21159e27f4	1562	#endif /* TCP_DEBUG */
darran	0:ac21159e27f4	1563
darran	0:ac21159e27f4	1564	#endif /* LWIP_TCP */

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	02 Jul 2010
Imports:	2
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	1

lwip/core/tcp.c@0:ac21159e27f4, 2010-07-02 (annotated)

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