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lwip/core/tcp.c@11:da4498f591ee, 2010-08-05 (annotated)

Committer:: donatien
Date:: Thu Aug 05 15:01:33 2010 +0000
Revision:: 11:da4498f591ee
Parent:: 5:dd63a1e02b1b

Who changed what in which revision?

User	Revision	Line number	New contents of line
donatien	0:632c9925f013	1	/**
donatien	0:632c9925f013	2	* @file
donatien	0:632c9925f013	3	* Transmission Control Protocol for IP
donatien	0:632c9925f013	4	*
donatien	0:632c9925f013	5	* This file contains common functions for the TCP implementation, such as functinos
donatien	0:632c9925f013	6	* for manipulating the data structures and the TCP timer functions. TCP functions
donatien	0:632c9925f013	7	* related to input and output is found in tcp_in.c and tcp_out.c respectively.
donatien	0:632c9925f013	8	*
donatien	0:632c9925f013	9	*/
donatien	0:632c9925f013	10
donatien	0:632c9925f013	11	/*
donatien	0:632c9925f013	12	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
donatien	0:632c9925f013	13	* All rights reserved.
donatien	0:632c9925f013	14	*
donatien	0:632c9925f013	15	* Redistribution and use in source and binary forms, with or without modification,
donatien	0:632c9925f013	16	* are permitted provided that the following conditions are met:
donatien	0:632c9925f013	17	*
donatien	0:632c9925f013	18	* 1. Redistributions of source code must retain the above copyright notice,
donatien	0:632c9925f013	19	* this list of conditions and the following disclaimer.
donatien	0:632c9925f013	20	* 2. Redistributions in binary form must reproduce the above copyright notice,
donatien	0:632c9925f013	21	* this list of conditions and the following disclaimer in the documentation
donatien	0:632c9925f013	22	* and/or other materials provided with the distribution.
donatien	0:632c9925f013	23	* 3. The name of the author may not be used to endorse or promote products
donatien	0:632c9925f013	24	* derived from this software without specific prior written permission.
donatien	0:632c9925f013	25	*
donatien	0:632c9925f013	26	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
donatien	0:632c9925f013	27	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
donatien	0:632c9925f013	28	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
donatien	0:632c9925f013	29	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
donatien	0:632c9925f013	30	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
donatien	0:632c9925f013	31	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
donatien	0:632c9925f013	32	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
donatien	0:632c9925f013	33	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
donatien	0:632c9925f013	34	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
donatien	0:632c9925f013	35	* OF SUCH DAMAGE.
donatien	0:632c9925f013	36	*
donatien	0:632c9925f013	37	* This file is part of the lwIP TCP/IP stack.
donatien	0:632c9925f013	38	*
donatien	0:632c9925f013	39	* Author: Adam Dunkels <adam@sics.se>
donatien	0:632c9925f013	40	*
donatien	0:632c9925f013	41	*/
donatien	0:632c9925f013	42
donatien	0:632c9925f013	43	#include "lwip/opt.h"
donatien	0:632c9925f013	44
donatien	0:632c9925f013	45	#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
donatien	0:632c9925f013	46
donatien	0:632c9925f013	47	#include "lwip/def.h"
donatien	0:632c9925f013	48	#include "lwip/mem.h"
donatien	0:632c9925f013	49	#include "lwip/memp.h"
donatien	0:632c9925f013	50	#include "lwip/snmp.h"
donatien	0:632c9925f013	51	#include "lwip/tcp.h"
donatien	0:632c9925f013	52	#include "lwip/tcp_impl.h"
donatien	0:632c9925f013	53	#include "lwip/debug.h"
donatien	0:632c9925f013	54	#include "lwip/stats.h"
donatien	0:632c9925f013	55
donatien	0:632c9925f013	56	#include <string.h>
donatien	0:632c9925f013	57
donatien	5:dd63a1e02b1b	58	const char * const tcp_state_str[] = {
donatien	0:632c9925f013	59	"CLOSED",
donatien	0:632c9925f013	60	"LISTEN",
donatien	0:632c9925f013	61	"SYN_SENT",
donatien	0:632c9925f013	62	"SYN_RCVD",
donatien	0:632c9925f013	63	"ESTABLISHED",
donatien	0:632c9925f013	64	"FIN_WAIT_1",
donatien	0:632c9925f013	65	"FIN_WAIT_2",
donatien	0:632c9925f013	66	"CLOSE_WAIT",
donatien	0:632c9925f013	67	"CLOSING",
donatien	0:632c9925f013	68	"LAST_ACK",
donatien	0:632c9925f013	69	"TIME_WAIT"
donatien	0:632c9925f013	70	};
donatien	0:632c9925f013	71
donatien	0:632c9925f013	72	/* Incremented every coarse grained timer shot (typically every 500 ms). */
donatien	0:632c9925f013	73	u32_t tcp_ticks;
donatien	0:632c9925f013	74	const u8_t tcp_backoff[13] =
donatien	0:632c9925f013	75	{ 1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7};
donatien	0:632c9925f013	76	/* Times per slowtmr hits */
donatien	0:632c9925f013	77	const u8_t tcp_persist_backoff[7] = { 3, 6, 12, 24, 48, 96, 120 };
donatien	0:632c9925f013	78
donatien	0:632c9925f013	79	/* The TCP PCB lists. */
donatien	0:632c9925f013	80
donatien	0:632c9925f013	81	/** List of all TCP PCBs bound but not yet (connected \|\| listening) */
donatien	0:632c9925f013	82	struct tcp_pcb *tcp_bound_pcbs;
donatien	0:632c9925f013	83	/** List of all TCP PCBs in LISTEN state */
donatien	0:632c9925f013	84	union tcp_listen_pcbs_t tcp_listen_pcbs;
donatien	0:632c9925f013	85	/** List of all TCP PCBs that are in a state in which
donatien	0:632c9925f013	86	* they accept or send data. */
donatien	0:632c9925f013	87	struct tcp_pcb *tcp_active_pcbs;
donatien	0:632c9925f013	88	/** List of all TCP PCBs in TIME-WAIT state */
donatien	0:632c9925f013	89	struct tcp_pcb *tcp_tw_pcbs;
donatien	0:632c9925f013	90
donatien	5:dd63a1e02b1b	91	#define NUM_TCP_PCB_LISTS 4
donatien	5:dd63a1e02b1b	92	#define NUM_TCP_PCB_LISTS_NO_TIME_WAIT 3
donatien	5:dd63a1e02b1b	93	/** An array with all (non-temporary) PCB lists, mainly used for smaller code size */
donatien	5:dd63a1e02b1b	94	struct tcp_pcb **tcp_pcb_lists[] = {&tcp_listen_pcbs.pcbs, &tcp_bound_pcbs,
donatien	5:dd63a1e02b1b	95	&tcp_active_pcbs, &tcp_tw_pcbs};
donatien	5:dd63a1e02b1b	96
donatien	0:632c9925f013	97	/** Only used for temporary storage. */
donatien	0:632c9925f013	98	struct tcp_pcb *tcp_tmp_pcb;
donatien	0:632c9925f013	99
donatien	0:632c9925f013	100	/** Timer counter to handle calling slow-timer from tcp_tmr() */
donatien	0:632c9925f013	101	static u8_t tcp_timer;
donatien	0:632c9925f013	102	static u16_t tcp_new_port(void);
donatien	0:632c9925f013	103
donatien	0:632c9925f013	104	/**
donatien	0:632c9925f013	105	* Called periodically to dispatch TCP timers.
donatien	0:632c9925f013	106	*
donatien	0:632c9925f013	107	*/
donatien	0:632c9925f013	108	void
donatien	0:632c9925f013	109	tcp_tmr(void)
donatien	0:632c9925f013	110	{
donatien	0:632c9925f013	111	/* Call tcp_fasttmr() every 250 ms */
donatien	0:632c9925f013	112	tcp_fasttmr();
donatien	0:632c9925f013	113
donatien	0:632c9925f013	114	if (++tcp_timer & 1) {
donatien	0:632c9925f013	115	/* Call tcp_tmr() every 500 ms, i.e., every other timer
donatien	0:632c9925f013	116	tcp_tmr() is called. */
donatien	0:632c9925f013	117	tcp_slowtmr();
donatien	0:632c9925f013	118	}
donatien	0:632c9925f013	119	}
donatien	0:632c9925f013	120
donatien	0:632c9925f013	121	/**
donatien	0:632c9925f013	122	* Closes the TX side of a connection held by the PCB.
donatien	0:632c9925f013	123	* For tcp_close(), a RST is sent if the application didn't receive all data
donatien	0:632c9925f013	124	* (tcp_recved() not called for all data passed to recv callback).
donatien	0:632c9925f013	125	*
donatien	0:632c9925f013	126	* Listening pcbs are freed and may not be referenced any more.
donatien	0:632c9925f013	127	* Connection pcbs are freed if not yet connected and may not be referenced
donatien	0:632c9925f013	128	* any more. If a connection is established (at least SYN received or in
donatien	0:632c9925f013	129	* a closing state), the connection is closed, and put in a closing state.
donatien	0:632c9925f013	130	* The pcb is then automatically freed in tcp_slowtmr(). It is therefore
donatien	0:632c9925f013	131	* unsafe to reference it.
donatien	0:632c9925f013	132	*
donatien	0:632c9925f013	133	* @param pcb the tcp_pcb to close
donatien	0:632c9925f013	134	* @return ERR_OK if connection has been closed
donatien	0:632c9925f013	135	* another err_t if closing failed and pcb is not freed
donatien	0:632c9925f013	136	*/
donatien	0:632c9925f013	137	static err_t
donatien	0:632c9925f013	138	tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
donatien	0:632c9925f013	139	{
donatien	0:632c9925f013	140	err_t err;
donatien	0:632c9925f013	141
donatien	0:632c9925f013	142	if (rst_on_unacked_data && (pcb->state != LISTEN)) {
donatien	5:dd63a1e02b1b	143	if ((pcb->refused_data != NULL) \|\| (pcb->rcv_wnd != TCP_WND)) {
donatien	0:632c9925f013	144	/* Not all data received by application, send RST to tell the remote
donatien	0:632c9925f013	145	side about this. */
donatien	5:dd63a1e02b1b	146	LWIP_ASSERT("pcb->flags & TF_RXCLOSED", pcb->flags & TF_RXCLOSED);
donatien	5:dd63a1e02b1b	147
donatien	5:dd63a1e02b1b	148	/* don't call tcp_abort here: we must not deallocate the pcb since
donatien	5:dd63a1e02b1b	149	that might not be expected when calling tcp_close */
donatien	0:632c9925f013	150	tcp_rst(pcb->snd_nxt, pcb->rcv_nxt, &pcb->local_ip, &pcb->remote_ip,
donatien	0:632c9925f013	151	pcb->local_port, pcb->remote_port);
donatien	5:dd63a1e02b1b	152
donatien	5:dd63a1e02b1b	153	tcp_pcb_purge(pcb);
donatien	5:dd63a1e02b1b	154
donatien	5:dd63a1e02b1b	155	/* TODO: to which state do we move now? */
donatien	5:dd63a1e02b1b	156
donatien	5:dd63a1e02b1b	157	/* move to TIME_WAIT since we close actively */
donatien	5:dd63a1e02b1b	158	TCP_RMV(&tcp_active_pcbs, pcb);
donatien	5:dd63a1e02b1b	159	pcb->state = TIME_WAIT;
donatien	5:dd63a1e02b1b	160	TCP_REG(&tcp_tw_pcbs, pcb);
donatien	5:dd63a1e02b1b	161
donatien	5:dd63a1e02b1b	162	return ERR_OK;
donatien	0:632c9925f013	163	}
donatien	0:632c9925f013	164	}
donatien	0:632c9925f013	165
donatien	0:632c9925f013	166	switch (pcb->state) {
donatien	0:632c9925f013	167	case CLOSED:
donatien	0:632c9925f013	168	/* Closing a pcb in the CLOSED state might seem erroneous,
donatien	0:632c9925f013	169	* however, it is in this state once allocated and as yet unused
donatien	0:632c9925f013	170	* and the user needs some way to free it should the need arise.
donatien	0:632c9925f013	171	* Calling tcp_close() with a pcb that has already been closed, (i.e. twice)
donatien	0:632c9925f013	172	* or for a pcb that has been used and then entered the CLOSED state
donatien	0:632c9925f013	173	* is erroneous, but this should never happen as the pcb has in those cases
donatien	0:632c9925f013	174	* been freed, and so any remaining handles are bogus. */
donatien	0:632c9925f013	175	err = ERR_OK;
donatien	0:632c9925f013	176	TCP_RMV(&tcp_bound_pcbs, pcb);
donatien	0:632c9925f013	177	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	178	pcb = NULL;
donatien	0:632c9925f013	179	break;
donatien	0:632c9925f013	180	case LISTEN:
donatien	0:632c9925f013	181	err = ERR_OK;
donatien	5:dd63a1e02b1b	182	tcp_pcb_remove(&tcp_listen_pcbs.pcbs, pcb);
donatien	0:632c9925f013	183	memp_free(MEMP_TCP_PCB_LISTEN, pcb);
donatien	0:632c9925f013	184	pcb = NULL;
donatien	0:632c9925f013	185	break;
donatien	0:632c9925f013	186	case SYN_SENT:
donatien	0:632c9925f013	187	err = ERR_OK;
donatien	0:632c9925f013	188	tcp_pcb_remove(&tcp_active_pcbs, pcb);
donatien	0:632c9925f013	189	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	190	pcb = NULL;
donatien	0:632c9925f013	191	snmp_inc_tcpattemptfails();
donatien	0:632c9925f013	192	break;
donatien	0:632c9925f013	193	case SYN_RCVD:
donatien	0:632c9925f013	194	err = tcp_send_fin(pcb);
donatien	0:632c9925f013	195	if (err == ERR_OK) {
donatien	0:632c9925f013	196	snmp_inc_tcpattemptfails();
donatien	0:632c9925f013	197	pcb->state = FIN_WAIT_1;
donatien	0:632c9925f013	198	}
donatien	0:632c9925f013	199	break;
donatien	0:632c9925f013	200	case ESTABLISHED:
donatien	0:632c9925f013	201	err = tcp_send_fin(pcb);
donatien	0:632c9925f013	202	if (err == ERR_OK) {
donatien	0:632c9925f013	203	snmp_inc_tcpestabresets();
donatien	0:632c9925f013	204	pcb->state = FIN_WAIT_1;
donatien	0:632c9925f013	205	}
donatien	0:632c9925f013	206	break;
donatien	0:632c9925f013	207	case CLOSE_WAIT:
donatien	0:632c9925f013	208	err = tcp_send_fin(pcb);
donatien	0:632c9925f013	209	if (err == ERR_OK) {
donatien	0:632c9925f013	210	snmp_inc_tcpestabresets();
donatien	0:632c9925f013	211	pcb->state = LAST_ACK;
donatien	0:632c9925f013	212	}
donatien	0:632c9925f013	213	break;
donatien	0:632c9925f013	214	default:
donatien	0:632c9925f013	215	/* Has already been closed, do nothing. */
donatien	0:632c9925f013	216	err = ERR_OK;
donatien	0:632c9925f013	217	pcb = NULL;
donatien	0:632c9925f013	218	break;
donatien	0:632c9925f013	219	}
donatien	0:632c9925f013	220
donatien	0:632c9925f013	221	if (pcb != NULL && err == ERR_OK) {
donatien	0:632c9925f013	222	/* To ensure all data has been sent when tcp_close returns, we have
donatien	0:632c9925f013	223	to make sure tcp_output doesn't fail.
donatien	0:632c9925f013	224	Since we don't really have to ensure all data has been sent when tcp_close
donatien	0:632c9925f013	225	returns (unsent data is sent from tcp timer functions, also), we don't care
donatien	0:632c9925f013	226	for the return value of tcp_output for now. */
donatien	0:632c9925f013	227	/* @todo: When implementing SO_LINGER, this must be changed somehow:
donatien	0:632c9925f013	228	If SOF_LINGER is set, the data should be sent and acked before close returns.
donatien	0:632c9925f013	229	This can only be valid for sequential APIs, not for the raw API. */
donatien	0:632c9925f013	230	tcp_output(pcb);
donatien	0:632c9925f013	231	}
donatien	0:632c9925f013	232	return err;
donatien	0:632c9925f013	233	}
donatien	0:632c9925f013	234
donatien	0:632c9925f013	235	/**
donatien	0:632c9925f013	236	* Closes the connection held by the PCB.
donatien	0:632c9925f013	237	*
donatien	0:632c9925f013	238	* Listening pcbs are freed and may not be referenced any more.
donatien	0:632c9925f013	239	* Connection pcbs are freed if not yet connected and may not be referenced
donatien	0:632c9925f013	240	* any more. If a connection is established (at least SYN received or in
donatien	0:632c9925f013	241	* a closing state), the connection is closed, and put in a closing state.
donatien	0:632c9925f013	242	* The pcb is then automatically freed in tcp_slowtmr(). It is therefore
donatien	0:632c9925f013	243	* unsafe to reference it (unless an error is returned).
donatien	0:632c9925f013	244	*
donatien	0:632c9925f013	245	* @param pcb the tcp_pcb to close
donatien	0:632c9925f013	246	* @return ERR_OK if connection has been closed
donatien	0:632c9925f013	247	* another err_t if closing failed and pcb is not freed
donatien	0:632c9925f013	248	*/
donatien	0:632c9925f013	249	err_t
donatien	0:632c9925f013	250	tcp_close(struct tcp_pcb *pcb)
donatien	0:632c9925f013	251	{
donatien	0:632c9925f013	252	#if TCP_DEBUG
donatien	0:632c9925f013	253	LWIP_DEBUGF(TCP_DEBUG, ("tcp_close: closing in "));
donatien	0:632c9925f013	254	tcp_debug_print_state(pcb->state);
donatien	0:632c9925f013	255	#endif /* TCP_DEBUG */
donatien	0:632c9925f013	256
donatien	0:632c9925f013	257	if (pcb->state != LISTEN) {
donatien	0:632c9925f013	258	/* Set a flag not to receive any more data... */
donatien	0:632c9925f013	259	pcb->flags \|= TF_RXCLOSED;
donatien	0:632c9925f013	260	}
donatien	0:632c9925f013	261	/* ... and close */
donatien	0:632c9925f013	262	return tcp_close_shutdown(pcb, 1);
donatien	0:632c9925f013	263	}
donatien	0:632c9925f013	264
donatien	0:632c9925f013	265	/**
donatien	0:632c9925f013	266	* Causes all or part of a full-duplex connection of this PCB to be shut down.
donatien	0:632c9925f013	267	* This doesn't deallocate the PCB!
donatien	0:632c9925f013	268	*
donatien	0:632c9925f013	269	* @param pcb PCB to shutdown
donatien	0:632c9925f013	270	* @param shut_rx shut down receive side if this is != 0
donatien	0:632c9925f013	271	* @param shut_tx shut down send side if this is != 0
donatien	0:632c9925f013	272	* @return ERR_OK if shutdown succeeded (or the PCB has already been shut down)
donatien	0:632c9925f013	273	* another err_t on error.
donatien	0:632c9925f013	274	*/
donatien	0:632c9925f013	275	err_t
donatien	0:632c9925f013	276	tcp_shutdown(struct tcp_pcb *pcb, int shut_rx, int shut_tx)
donatien	0:632c9925f013	277	{
donatien	0:632c9925f013	278	if (pcb->state == LISTEN) {
donatien	0:632c9925f013	279	return ERR_CONN;
donatien	0:632c9925f013	280	}
donatien	0:632c9925f013	281	if (shut_rx) {
donatien	0:632c9925f013	282	/* shut down the receive side: free buffered data... */
donatien	0:632c9925f013	283	if (pcb->refused_data != NULL) {
donatien	0:632c9925f013	284	pbuf_free(pcb->refused_data);
donatien	0:632c9925f013	285	pcb->refused_data = NULL;
donatien	0:632c9925f013	286	}
donatien	0:632c9925f013	287	/* ... and set a flag not to receive any more data */
donatien	0:632c9925f013	288	pcb->flags \|= TF_RXCLOSED;
donatien	0:632c9925f013	289	}
donatien	0:632c9925f013	290	if (shut_tx) {
donatien	0:632c9925f013	291	/* This can't happen twice since if it succeeds, the pcb's state is changed.
donatien	0:632c9925f013	292	Only close in these states as the others directly deallocate the PCB */
donatien	0:632c9925f013	293	switch (pcb->state) {
donatien	0:632c9925f013	294	case SYN_RCVD:
donatien	0:632c9925f013	295	case ESTABLISHED:
donatien	0:632c9925f013	296	case CLOSE_WAIT:
donatien	0:632c9925f013	297	return tcp_close_shutdown(pcb, 0);
donatien	0:632c9925f013	298	default:
donatien	0:632c9925f013	299	/* don't shut down other states */
donatien	0:632c9925f013	300	break;
donatien	0:632c9925f013	301	}
donatien	0:632c9925f013	302	}
donatien	0:632c9925f013	303	/* @todo: return another err_t if not in correct state or already shut? */
donatien	0:632c9925f013	304	return ERR_OK;
donatien	0:632c9925f013	305	}
donatien	0:632c9925f013	306
donatien	0:632c9925f013	307	/**
donatien	0:632c9925f013	308	* Abandons a connection and optionally sends a RST to the remote
donatien	0:632c9925f013	309	* host. Deletes the local protocol control block. This is done when
donatien	0:632c9925f013	310	* a connection is killed because of shortage of memory.
donatien	0:632c9925f013	311	*
donatien	0:632c9925f013	312	* @param pcb the tcp_pcb to abort
donatien	0:632c9925f013	313	* @param reset boolean to indicate whether a reset should be sent
donatien	0:632c9925f013	314	*/
donatien	0:632c9925f013	315	void
donatien	0:632c9925f013	316	tcp_abandon(struct tcp_pcb *pcb, int reset)
donatien	0:632c9925f013	317	{
donatien	0:632c9925f013	318	u32_t seqno, ackno;
donatien	0:632c9925f013	319	u16_t remote_port, local_port;
donatien	0:632c9925f013	320	ip_addr_t remote_ip, local_ip;
donatien	0:632c9925f013	321	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	322	tcp_err_fn errf;
donatien	0:632c9925f013	323	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	324	void *errf_arg;
donatien	0:632c9925f013	325
donatien	5:dd63a1e02b1b	326	/* pcb->state LISTEN not allowed here */
donatien	5:dd63a1e02b1b	327	LWIP_ASSERT("don't call tcp_abort/tcp_abandon for listen-pcbs",
donatien	5:dd63a1e02b1b	328	pcb->state != LISTEN);
donatien	0:632c9925f013	329	/* Figure out on which TCP PCB list we are, and remove us. If we
donatien	0:632c9925f013	330	are in an active state, call the receive function associated with
donatien	0:632c9925f013	331	the PCB with a NULL argument, and send an RST to the remote end. */
donatien	0:632c9925f013	332	if (pcb->state == TIME_WAIT) {
donatien	0:632c9925f013	333	tcp_pcb_remove(&tcp_tw_pcbs, pcb);
donatien	0:632c9925f013	334	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	335	} else {
donatien	0:632c9925f013	336	seqno = pcb->snd_nxt;
donatien	0:632c9925f013	337	ackno = pcb->rcv_nxt;
donatien	0:632c9925f013	338	ip_addr_copy(local_ip, pcb->local_ip);
donatien	0:632c9925f013	339	ip_addr_copy(remote_ip, pcb->remote_ip);
donatien	0:632c9925f013	340	local_port = pcb->local_port;
donatien	0:632c9925f013	341	remote_port = pcb->remote_port;
donatien	0:632c9925f013	342	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	343	errf = pcb->errf;
donatien	0:632c9925f013	344	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	345	errf_arg = pcb->callback_arg;
donatien	0:632c9925f013	346	tcp_pcb_remove(&tcp_active_pcbs, pcb);
donatien	0:632c9925f013	347	if (pcb->unacked != NULL) {
donatien	0:632c9925f013	348	tcp_segs_free(pcb->unacked);
donatien	0:632c9925f013	349	}
donatien	0:632c9925f013	350	if (pcb->unsent != NULL) {
donatien	0:632c9925f013	351	tcp_segs_free(pcb->unsent);
donatien	0:632c9925f013	352	}
donatien	0:632c9925f013	353	#if TCP_QUEUE_OOSEQ
donatien	0:632c9925f013	354	if (pcb->ooseq != NULL) {
donatien	0:632c9925f013	355	tcp_segs_free(pcb->ooseq);
donatien	0:632c9925f013	356	}
donatien	0:632c9925f013	357	#endif /* TCP_QUEUE_OOSEQ */
donatien	0:632c9925f013	358	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	359	TCP_EVENT_ERR(errf, errf_arg, ERR_ABRT);
donatien	0:632c9925f013	360	if (reset) {
donatien	0:632c9925f013	361	LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_abandon: sending RST\n"));
donatien	0:632c9925f013	362	tcp_rst(seqno, ackno, &local_ip, &remote_ip, local_port, remote_port);
donatien	0:632c9925f013	363	}
donatien	0:632c9925f013	364	}
donatien	0:632c9925f013	365	}
donatien	0:632c9925f013	366
donatien	0:632c9925f013	367	/**
donatien	0:632c9925f013	368	* Aborts the connection by sending a RST (reset) segment to the remote
donatien	0:632c9925f013	369	* host. The pcb is deallocated. This function never fails.
donatien	0:632c9925f013	370	*
donatien	0:632c9925f013	371	* ATTENTION: When calling this from one of the TCP callbacks, make
donatien	0:632c9925f013	372	* sure you always return ERR_ABRT (and never return ERR_ABRT otherwise
donatien	0:632c9925f013	373	* or you will risk accessing deallocated memory or memory leaks!
donatien	0:632c9925f013	374	*
donatien	0:632c9925f013	375	* @param pcb the tcp pcb to abort
donatien	0:632c9925f013	376	*/
donatien	0:632c9925f013	377	void
donatien	0:632c9925f013	378	tcp_abort(struct tcp_pcb *pcb)
donatien	0:632c9925f013	379	{
donatien	0:632c9925f013	380	tcp_abandon(pcb, 1);
donatien	0:632c9925f013	381	}
donatien	0:632c9925f013	382
donatien	0:632c9925f013	383	/**
donatien	0:632c9925f013	384	* Binds the connection to a local portnumber and IP address. If the
donatien	0:632c9925f013	385	* IP address is not given (i.e., ipaddr == NULL), the IP address of
donatien	0:632c9925f013	386	* the outgoing network interface is used instead.
donatien	0:632c9925f013	387	*
donatien	0:632c9925f013	388	* @param pcb the tcp_pcb to bind (no check is done whether this pcb is
donatien	0:632c9925f013	389	* already bound!)
donatien	0:632c9925f013	390	* @param ipaddr the local ip address to bind to (use IP_ADDR_ANY to bind
donatien	0:632c9925f013	391	* to any local address
donatien	0:632c9925f013	392	* @param port the local port to bind to
donatien	0:632c9925f013	393	* @return ERR_USE if the port is already in use
donatien	0:632c9925f013	394	* ERR_OK if bound
donatien	0:632c9925f013	395	*/
donatien	0:632c9925f013	396	err_t
donatien	0:632c9925f013	397	tcp_bind(struct tcp_pcb pcb, ip_addr_t ipaddr, u16_t port)
donatien	0:632c9925f013	398	{
donatien	5:dd63a1e02b1b	399	int i;
donatien	5:dd63a1e02b1b	400	int max_pcb_list = NUM_TCP_PCB_LISTS;
donatien	0:632c9925f013	401	struct tcp_pcb *cpcb;
donatien	0:632c9925f013	402
donatien	0:632c9925f013	403	LWIP_ERROR("tcp_bind: can only bind in state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
donatien	0:632c9925f013	404
donatien	5:dd63a1e02b1b	405	#if SO_REUSE
donatien	5:dd63a1e02b1b	406	/* Unless the REUSEADDR flag is set,
donatien	5:dd63a1e02b1b	407	we have to check the pcbs in TIME-WAIT state, also.
donatien	5:dd63a1e02b1b	408	We do not dump TIME_WAIT pcb's; they can still be matched by incoming
donatien	5:dd63a1e02b1b	409	packets using both local and remote IP addresses and ports to distinguish.
donatien	5:dd63a1e02b1b	410	*/
donatien	5:dd63a1e02b1b	411	#if SO_REUSE
donatien	5:dd63a1e02b1b	412	if ((pcb->so_options & SOF_REUSEADDR) != 0) {
donatien	5:dd63a1e02b1b	413	max_pcb_list = NUM_TCP_PCB_LISTS_NO_TIME_WAIT;
donatien	5:dd63a1e02b1b	414	}
donatien	5:dd63a1e02b1b	415	#endif /* SO_REUSE */
donatien	5:dd63a1e02b1b	416	#endif /* SO_REUSE */
donatien	5:dd63a1e02b1b	417
donatien	0:632c9925f013	418	if (port == 0) {
donatien	0:632c9925f013	419	port = tcp_new_port();
donatien	0:632c9925f013	420	}
donatien	5:dd63a1e02b1b	421
donatien	5:dd63a1e02b1b	422	/* Check if the address already is in use (on all lists) */
donatien	5:dd63a1e02b1b	423	for (i = 0; i < max_pcb_list; i++) {
donatien	5:dd63a1e02b1b	424	for(cpcb = *tcp_pcb_lists[i]; cpcb != NULL; cpcb = cpcb->next) {
donatien	0:632c9925f013	425	if (cpcb->local_port == port) {
donatien	5:dd63a1e02b1b	426	#if SO_REUSE
donatien	5:dd63a1e02b1b	427	/* Omit checking for the same port if both pcbs have REUSEADDR set.
donatien	5:dd63a1e02b1b	428	For SO_REUSEADDR, the duplicate-check for a 5-tuple is done in
donatien	5:dd63a1e02b1b	429	tcp_connect. */
donatien	5:dd63a1e02b1b	430	if (((pcb->so_options & SOF_REUSEADDR) == 0) \|\|
donatien	5:dd63a1e02b1b	431	((cpcb->so_options & SOF_REUSEADDR) == 0))
donatien	5:dd63a1e02b1b	432	#endif /* SO_REUSE */
donatien	5:dd63a1e02b1b	433	{
donatien	5:dd63a1e02b1b	434	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
donatien	5:dd63a1e02b1b	435	ip_addr_isany(ipaddr) \|\|
donatien	5:dd63a1e02b1b	436	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
donatien	5:dd63a1e02b1b	437	return ERR_USE;
donatien	5:dd63a1e02b1b	438	}
donatien	0:632c9925f013	439	}
donatien	0:632c9925f013	440	}
donatien	0:632c9925f013	441	}
donatien	0:632c9925f013	442	}
donatien	0:632c9925f013	443
donatien	0:632c9925f013	444	if (!ip_addr_isany(ipaddr)) {
donatien	0:632c9925f013	445	pcb->local_ip = *ipaddr;
donatien	0:632c9925f013	446	}
donatien	0:632c9925f013	447	pcb->local_port = port;
donatien	0:632c9925f013	448	TCP_REG(&tcp_bound_pcbs, pcb);
donatien	0:632c9925f013	449	LWIP_DEBUGF(TCP_DEBUG, ("tcp_bind: bind to port %"U16_F"\n", port));
donatien	0:632c9925f013	450	return ERR_OK;
donatien	0:632c9925f013	451	}
donatien	0:632c9925f013	452	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	453	/**
donatien	0:632c9925f013	454	* Default accept callback if no accept callback is specified by the user.
donatien	0:632c9925f013	455	*/
donatien	0:632c9925f013	456	static err_t
donatien	0:632c9925f013	457	tcp_accept_null(void arg, struct tcp_pcb pcb, err_t err)
donatien	0:632c9925f013	458	{
donatien	0:632c9925f013	459	LWIP_UNUSED_ARG(arg);
donatien	0:632c9925f013	460	LWIP_UNUSED_ARG(pcb);
donatien	0:632c9925f013	461	LWIP_UNUSED_ARG(err);
donatien	0:632c9925f013	462
donatien	0:632c9925f013	463	return ERR_ABRT;
donatien	0:632c9925f013	464	}
donatien	0:632c9925f013	465	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	466
donatien	0:632c9925f013	467	/**
donatien	0:632c9925f013	468	* Set the state of the connection to be LISTEN, which means that it
donatien	0:632c9925f013	469	* is able to accept incoming connections. The protocol control block
donatien	0:632c9925f013	470	* is reallocated in order to consume less memory. Setting the
donatien	0:632c9925f013	471	* connection to LISTEN is an irreversible process.
donatien	0:632c9925f013	472	*
donatien	0:632c9925f013	473	* @param pcb the original tcp_pcb
donatien	0:632c9925f013	474	* @param backlog the incoming connections queue limit
donatien	0:632c9925f013	475	* @return tcp_pcb used for listening, consumes less memory.
donatien	0:632c9925f013	476	*
donatien	0:632c9925f013	477	* @note The original tcp_pcb is freed. This function therefore has to be
donatien	0:632c9925f013	478	* called like this:
donatien	0:632c9925f013	479	* tpcb = tcp_listen(tpcb);
donatien	0:632c9925f013	480	*/
donatien	0:632c9925f013	481	struct tcp_pcb *
donatien	0:632c9925f013	482	tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog)
donatien	0:632c9925f013	483	{
donatien	0:632c9925f013	484	struct tcp_pcb_listen *lpcb;
donatien	0:632c9925f013	485
donatien	0:632c9925f013	486	LWIP_UNUSED_ARG(backlog);
donatien	0:632c9925f013	487	LWIP_ERROR("tcp_listen: pcb already connected", pcb->state == CLOSED, return NULL);
donatien	0:632c9925f013	488
donatien	0:632c9925f013	489	/* already listening? */
donatien	0:632c9925f013	490	if (pcb->state == LISTEN) {
donatien	0:632c9925f013	491	return pcb;
donatien	0:632c9925f013	492	}
donatien	5:dd63a1e02b1b	493	#if SO_REUSE
donatien	5:dd63a1e02b1b	494	if ((pcb->so_options & SOF_REUSEADDR) != 0) {
donatien	5:dd63a1e02b1b	495	/* Since SOF_REUSEADDR allows reusing a local address before the pcb's usage
donatien	5:dd63a1e02b1b	496	is declared (listen-/connection-pcb), we have to make sure now that
donatien	5:dd63a1e02b1b	497	this port is only used once for every local IP. */
donatien	5:dd63a1e02b1b	498	for(lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
donatien	5:dd63a1e02b1b	499	if (lpcb->local_port == pcb->local_port) {
donatien	5:dd63a1e02b1b	500	if (ip_addr_cmp(&lpcb->local_ip, &pcb->local_ip)) {
donatien	5:dd63a1e02b1b	501	/* this address/port is already used */
donatien	5:dd63a1e02b1b	502	return NULL;
donatien	5:dd63a1e02b1b	503	}
donatien	5:dd63a1e02b1b	504	}
donatien	5:dd63a1e02b1b	505	}
donatien	5:dd63a1e02b1b	506	}
donatien	5:dd63a1e02b1b	507	#endif /* SO_REUSE */
donatien	0:632c9925f013	508	lpcb = (struct tcp_pcb_listen *)memp_malloc(MEMP_TCP_PCB_LISTEN);
donatien	0:632c9925f013	509	if (lpcb == NULL) {
donatien	0:632c9925f013	510	return NULL;
donatien	0:632c9925f013	511	}
donatien	0:632c9925f013	512	lpcb->callback_arg = pcb->callback_arg;
donatien	0:632c9925f013	513	lpcb->local_port = pcb->local_port;
donatien	0:632c9925f013	514	lpcb->state = LISTEN;
donatien	5:dd63a1e02b1b	515	lpcb->prio = pcb->prio;
donatien	0:632c9925f013	516	lpcb->so_options = pcb->so_options;
donatien	0:632c9925f013	517	lpcb->so_options \|= SOF_ACCEPTCONN;
donatien	0:632c9925f013	518	lpcb->ttl = pcb->ttl;
donatien	0:632c9925f013	519	lpcb->tos = pcb->tos;
donatien	0:632c9925f013	520	ip_addr_copy(lpcb->local_ip, pcb->local_ip);
donatien	0:632c9925f013	521	TCP_RMV(&tcp_bound_pcbs, pcb);
donatien	0:632c9925f013	522	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	523	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	524	lpcb->accept = tcp_accept_null;
donatien	0:632c9925f013	525	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	526	#if TCP_LISTEN_BACKLOG
donatien	0:632c9925f013	527	lpcb->accepts_pending = 0;
donatien	0:632c9925f013	528	lpcb->backlog = (backlog ? backlog : 1);
donatien	0:632c9925f013	529	#endif /* TCP_LISTEN_BACKLOG */
donatien	5:dd63a1e02b1b	530	TCP_REG(&tcp_listen_pcbs.pcbs, (struct tcp_pcb *)lpcb);
donatien	0:632c9925f013	531	return (struct tcp_pcb *)lpcb;
donatien	0:632c9925f013	532	}
donatien	0:632c9925f013	533
donatien	0:632c9925f013	534	/**
donatien	0:632c9925f013	535	* Update the state that tracks the available window space to advertise.
donatien	0:632c9925f013	536	*
donatien	0:632c9925f013	537	* Returns how much extra window would be advertised if we sent an
donatien	0:632c9925f013	538	* update now.
donatien	0:632c9925f013	539	*/
donatien	0:632c9925f013	540	u32_t tcp_update_rcv_ann_wnd(struct tcp_pcb *pcb)
donatien	0:632c9925f013	541	{
donatien	0:632c9925f013	542	u32_t new_right_edge = pcb->rcv_nxt + pcb->rcv_wnd;
donatien	0:632c9925f013	543
donatien	0:632c9925f013	544	if (TCP_SEQ_GEQ(new_right_edge, pcb->rcv_ann_right_edge + LWIP_MIN((TCP_WND / 2), pcb->mss))) {
donatien	0:632c9925f013	545	/* we can advertise more window */
donatien	0:632c9925f013	546	pcb->rcv_ann_wnd = pcb->rcv_wnd;
donatien	0:632c9925f013	547	return new_right_edge - pcb->rcv_ann_right_edge;
donatien	0:632c9925f013	548	} else {
donatien	0:632c9925f013	549	if (TCP_SEQ_GT(pcb->rcv_nxt, pcb->rcv_ann_right_edge)) {
donatien	0:632c9925f013	550	/* Can happen due to other end sending out of advertised window,
donatien	0:632c9925f013	551	* but within actual available (but not yet advertised) window */
donatien	0:632c9925f013	552	pcb->rcv_ann_wnd = 0;
donatien	0:632c9925f013	553	} else {
donatien	0:632c9925f013	554	/* keep the right edge of window constant */
donatien	0:632c9925f013	555	u32_t new_rcv_ann_wnd = pcb->rcv_ann_right_edge - pcb->rcv_nxt;
donatien	0:632c9925f013	556	LWIP_ASSERT("new_rcv_ann_wnd <= 0xffff", new_rcv_ann_wnd <= 0xffff);
donatien	0:632c9925f013	557	pcb->rcv_ann_wnd = (u16_t)new_rcv_ann_wnd;
donatien	0:632c9925f013	558	}
donatien	0:632c9925f013	559	return 0;
donatien	0:632c9925f013	560	}
donatien	0:632c9925f013	561	}
donatien	0:632c9925f013	562
donatien	0:632c9925f013	563	/**
donatien	0:632c9925f013	564	* This function should be called by the application when it has
donatien	0:632c9925f013	565	* processed the data. The purpose is to advertise a larger window
donatien	0:632c9925f013	566	* when the data has been processed.
donatien	0:632c9925f013	567	*
donatien	0:632c9925f013	568	* @param pcb the tcp_pcb for which data is read
donatien	0:632c9925f013	569	* @param len the amount of bytes that have been read by the application
donatien	0:632c9925f013	570	*/
donatien	0:632c9925f013	571	void
donatien	0:632c9925f013	572	tcp_recved(struct tcp_pcb *pcb, u16_t len)
donatien	0:632c9925f013	573	{
donatien	0:632c9925f013	574	int wnd_inflation;
donatien	0:632c9925f013	575
donatien	0:632c9925f013	576	LWIP_ASSERT("tcp_recved: len would wrap rcv_wnd\n",
donatien	0:632c9925f013	577	len <= 0xffff - pcb->rcv_wnd );
donatien	0:632c9925f013	578
donatien	0:632c9925f013	579	pcb->rcv_wnd += len;
donatien	0:632c9925f013	580	if (pcb->rcv_wnd > TCP_WND) {
donatien	0:632c9925f013	581	pcb->rcv_wnd = TCP_WND;
donatien	0:632c9925f013	582	}
donatien	0:632c9925f013	583
donatien	0:632c9925f013	584	wnd_inflation = tcp_update_rcv_ann_wnd(pcb);
donatien	0:632c9925f013	585
donatien	0:632c9925f013	586	/* If the change in the right edge of window is significant (default
donatien	0:632c9925f013	587	* watermark is TCP_WND/4), then send an explicit update now.
donatien	0:632c9925f013	588	* Otherwise wait for a packet to be sent in the normal course of
donatien	0:632c9925f013	589	* events (or more window to be available later) */
donatien	0:632c9925f013	590	if (wnd_inflation >= TCP_WND_UPDATE_THRESHOLD) {
donatien	0:632c9925f013	591	tcp_ack_now(pcb);
donatien	0:632c9925f013	592	tcp_output(pcb);
donatien	0:632c9925f013	593	}
donatien	0:632c9925f013	594
donatien	0:632c9925f013	595	LWIP_DEBUGF(TCP_DEBUG, ("tcp_recved: recveived %"U16_F" bytes, wnd %"U16_F" (%"U16_F").\n",
donatien	0:632c9925f013	596	len, pcb->rcv_wnd, TCP_WND - pcb->rcv_wnd));
donatien	0:632c9925f013	597	}
donatien	0:632c9925f013	598
donatien	0:632c9925f013	599	/**
donatien	0:632c9925f013	600	* A nastly hack featuring 'goto' statements that allocates a
donatien	0:632c9925f013	601	* new TCP local port.
donatien	0:632c9925f013	602	*
donatien	0:632c9925f013	603	* @return a new (free) local TCP port number
donatien	0:632c9925f013	604	*/
donatien	0:632c9925f013	605	static u16_t
donatien	0:632c9925f013	606	tcp_new_port(void)
donatien	0:632c9925f013	607	{
donatien	5:dd63a1e02b1b	608	int i;
donatien	0:632c9925f013	609	struct tcp_pcb *pcb;
donatien	0:632c9925f013	610	#ifndef TCP_LOCAL_PORT_RANGE_START
donatien	0:632c9925f013	611	#define TCP_LOCAL_PORT_RANGE_START 4096
donatien	0:632c9925f013	612	#define TCP_LOCAL_PORT_RANGE_END 0x7fff
donatien	0:632c9925f013	613	#endif
donatien	0:632c9925f013	614	static u16_t port = TCP_LOCAL_PORT_RANGE_START;
donatien	0:632c9925f013	615
donatien	0:632c9925f013	616	again:
donatien	0:632c9925f013	617	if (++port > TCP_LOCAL_PORT_RANGE_END) {
donatien	0:632c9925f013	618	port = TCP_LOCAL_PORT_RANGE_START;
donatien	0:632c9925f013	619	}
donatien	5:dd63a1e02b1b	620	/* Check all PCB lists. */
donatien	5:dd63a1e02b1b	621	for (i = 1; i < NUM_TCP_PCB_LISTS; i++) {
donatien	5:dd63a1e02b1b	622	for(pcb = *tcp_pcb_lists[i]; pcb != NULL; pcb = pcb->next) {
donatien	5:dd63a1e02b1b	623	if (pcb->local_port == port) {
donatien	5:dd63a1e02b1b	624	goto again;
donatien	5:dd63a1e02b1b	625	}
donatien	0:632c9925f013	626	}
donatien	0:632c9925f013	627	}
donatien	0:632c9925f013	628	return port;
donatien	0:632c9925f013	629	}
donatien	0:632c9925f013	630
donatien	0:632c9925f013	631	/**
donatien	0:632c9925f013	632	* Connects to another host. The function given as the "connected"
donatien	0:632c9925f013	633	* argument will be called when the connection has been established.
donatien	0:632c9925f013	634	*
donatien	0:632c9925f013	635	* @param pcb the tcp_pcb used to establish the connection
donatien	0:632c9925f013	636	* @param ipaddr the remote ip address to connect to
donatien	0:632c9925f013	637	* @param port the remote tcp port to connect to
donatien	0:632c9925f013	638	* @param connected callback function to call when connected (or on error)
donatien	0:632c9925f013	639	* @return ERR_VAL if invalid arguments are given
donatien	0:632c9925f013	640	* ERR_OK if connect request has been sent
donatien	0:632c9925f013	641	* other err_t values if connect request couldn't be sent
donatien	0:632c9925f013	642	*/
donatien	0:632c9925f013	643	err_t
donatien	0:632c9925f013	644	tcp_connect(struct tcp_pcb pcb, ip_addr_t ipaddr, u16_t port,
donatien	0:632c9925f013	645	tcp_connected_fn connected)
donatien	0:632c9925f013	646	{
donatien	0:632c9925f013	647	err_t ret;
donatien	0:632c9925f013	648	u32_t iss;
donatien	0:632c9925f013	649
donatien	0:632c9925f013	650	LWIP_ERROR("tcp_connect: can only connected from state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
donatien	0:632c9925f013	651
donatien	0:632c9925f013	652	LWIP_DEBUGF(TCP_DEBUG, ("tcp_connect to port %"U16_F"\n", port));
donatien	0:632c9925f013	653	if (ipaddr != NULL) {
donatien	0:632c9925f013	654	pcb->remote_ip = *ipaddr;
donatien	0:632c9925f013	655	} else {
donatien	0:632c9925f013	656	return ERR_VAL;
donatien	0:632c9925f013	657	}
donatien	0:632c9925f013	658	pcb->remote_port = port;
donatien	5:dd63a1e02b1b	659
donatien	5:dd63a1e02b1b	660	/* check if we have a route to the remote host */
donatien	5:dd63a1e02b1b	661	if (ip_addr_isany(&(pcb->local_ip))) {
donatien	5:dd63a1e02b1b	662	/* no local IP address set, yet. */
donatien	5:dd63a1e02b1b	663	struct netif *netif = ip_route(&(pcb->remote_ip));
donatien	5:dd63a1e02b1b	664	if (netif == NULL) {
donatien	5:dd63a1e02b1b	665	/* Don't even try to send a SYN packet if we have no route
donatien	5:dd63a1e02b1b	666	since that will fail. */
donatien	5:dd63a1e02b1b	667	return ERR_RTE;
donatien	5:dd63a1e02b1b	668	}
donatien	5:dd63a1e02b1b	669	/* Use the netif's IP address as local address. */
donatien	5:dd63a1e02b1b	670	ip_addr_copy(pcb->local_ip, netif->ip_addr);
donatien	5:dd63a1e02b1b	671	}
donatien	5:dd63a1e02b1b	672
donatien	0:632c9925f013	673	if (pcb->local_port == 0) {
donatien	0:632c9925f013	674	pcb->local_port = tcp_new_port();
donatien	0:632c9925f013	675	}
donatien	5:dd63a1e02b1b	676	#if SO_REUSE
donatien	5:dd63a1e02b1b	677	if ((pcb->so_options & SOF_REUSEADDR) != 0) {
donatien	5:dd63a1e02b1b	678	/* Since SOF_REUSEADDR allows reusing a local address, we have to make sure
donatien	5:dd63a1e02b1b	679	now that the 5-tuple is unique. */
donatien	5:dd63a1e02b1b	680	struct tcp_pcb *cpcb;
donatien	5:dd63a1e02b1b	681	int i;
donatien	5:dd63a1e02b1b	682	/* Don't check listen PCBs, check bound-, active- and TIME-WAIT PCBs. */
donatien	5:dd63a1e02b1b	683	for (i = 1; i < NUM_TCP_PCB_LISTS; i++) {
donatien	5:dd63a1e02b1b	684	for(cpcb = *tcp_pcb_lists[i]; cpcb != NULL; cpcb = cpcb->next) {
donatien	5:dd63a1e02b1b	685	if ((cpcb->local_port == pcb->local_port) &&
donatien	5:dd63a1e02b1b	686	(cpcb->remote_port == port) &&
donatien	5:dd63a1e02b1b	687	ip_addr_cmp(&cpcb->local_ip, &pcb->local_ip) &&
donatien	5:dd63a1e02b1b	688	ip_addr_cmp(&cpcb->remote_ip, ipaddr)) {
donatien	5:dd63a1e02b1b	689	/* linux returns EISCONN here, but ERR_USE should be OK for us */
donatien	5:dd63a1e02b1b	690	return ERR_USE;
donatien	5:dd63a1e02b1b	691	}
donatien	5:dd63a1e02b1b	692	}
donatien	5:dd63a1e02b1b	693	}
donatien	5:dd63a1e02b1b	694	}
donatien	5:dd63a1e02b1b	695	#endif /* SO_REUSE */
donatien	0:632c9925f013	696	iss = tcp_next_iss();
donatien	0:632c9925f013	697	pcb->rcv_nxt = 0;
donatien	0:632c9925f013	698	pcb->snd_nxt = iss;
donatien	0:632c9925f013	699	pcb->lastack = iss - 1;
donatien	0:632c9925f013	700	pcb->snd_lbb = iss - 1;
donatien	0:632c9925f013	701	pcb->rcv_wnd = TCP_WND;
donatien	0:632c9925f013	702	pcb->rcv_ann_wnd = TCP_WND;
donatien	0:632c9925f013	703	pcb->rcv_ann_right_edge = pcb->rcv_nxt;
donatien	0:632c9925f013	704	pcb->snd_wnd = TCP_WND;
donatien	0:632c9925f013	705	/* As initial send MSS, we use TCP_MSS but limit it to 536.
donatien	0:632c9925f013	706	The send MSS is updated when an MSS option is received. */
donatien	0:632c9925f013	707	pcb->mss = (TCP_MSS > 536) ? 536 : TCP_MSS;
donatien	0:632c9925f013	708	#if TCP_CALCULATE_EFF_SEND_MSS
donatien	0:632c9925f013	709	pcb->mss = tcp_eff_send_mss(pcb->mss, ipaddr);
donatien	0:632c9925f013	710	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
donatien	0:632c9925f013	711	pcb->cwnd = 1;
donatien	0:632c9925f013	712	pcb->ssthresh = pcb->mss * 10;
donatien	0:632c9925f013	713	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	714	pcb->connected = connected;
donatien	5:dd63a1e02b1b	715	#else /* LWIP_CALLBACK_API */
donatien	5:dd63a1e02b1b	716	LWIP_UNUSED_ARG(connected);
donatien	0:632c9925f013	717	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	718
donatien	5:dd63a1e02b1b	719	LWIP_DEBUGF(TCP_DEBUG, ("tcp_connect: tcp_ticks=%"U32_F" iss=%"U32_F"\n", tcp_ticks, iss));
donatien	5:dd63a1e02b1b	720
donatien	0:632c9925f013	721	/* Send a SYN together with the MSS option. */
donatien	0:632c9925f013	722	ret = tcp_enqueue_flags(pcb, TCP_SYN);
donatien	0:632c9925f013	723	if (ret == ERR_OK) {
donatien	0:632c9925f013	724	/* SYN segment was enqueued, changed the pcbs state now */
donatien	0:632c9925f013	725	pcb->state = SYN_SENT;
donatien	0:632c9925f013	726	TCP_RMV(&tcp_bound_pcbs, pcb);
donatien	0:632c9925f013	727	TCP_REG(&tcp_active_pcbs, pcb);
donatien	0:632c9925f013	728	snmp_inc_tcpactiveopens();
donatien	0:632c9925f013	729
donatien	0:632c9925f013	730	tcp_output(pcb);
donatien	0:632c9925f013	731	}
donatien	0:632c9925f013	732	return ret;
donatien	0:632c9925f013	733	}
donatien	0:632c9925f013	734
donatien	0:632c9925f013	735	/**
donatien	0:632c9925f013	736	* Called every 500 ms and implements the retransmission timer and the timer that
donatien	0:632c9925f013	737	* removes PCBs that have been in TIME-WAIT for enough time. It also increments
donatien	0:632c9925f013	738	* various timers such as the inactivity timer in each PCB.
donatien	0:632c9925f013	739	*
donatien	0:632c9925f013	740	* Automatically called from tcp_tmr().
donatien	0:632c9925f013	741	*/
donatien	0:632c9925f013	742	void
donatien	0:632c9925f013	743	tcp_slowtmr(void)
donatien	0:632c9925f013	744	{
donatien	0:632c9925f013	745	struct tcp_pcb pcb, pcb2, *prev;
donatien	0:632c9925f013	746	u16_t eff_wnd;
donatien	0:632c9925f013	747	u8_t pcb_remove; /* flag if a PCB should be removed */
donatien	0:632c9925f013	748	u8_t pcb_reset; /* flag if a RST should be sent when removing */
donatien	0:632c9925f013	749	err_t err;
donatien	5:dd63a1e02b1b	750
donatien	5:dd63a1e02b1b	751	tcp_debug_print_pcbs(); //DG
donatien	0:632c9925f013	752
donatien	0:632c9925f013	753	err = ERR_OK;
donatien	0:632c9925f013	754
donatien	0:632c9925f013	755	++tcp_ticks;
donatien	5:dd63a1e02b1b	756	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: tcp_ticks=%"U32_F"\n", tcp_ticks));
donatien	0:632c9925f013	757
donatien	0:632c9925f013	758	/* Steps through all of the active PCBs. */
donatien	0:632c9925f013	759	prev = NULL;
donatien	0:632c9925f013	760	pcb = tcp_active_pcbs;
donatien	0:632c9925f013	761	if (pcb == NULL) {
donatien	0:632c9925f013	762	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: no active pcbs\n"));
donatien	0:632c9925f013	763	}
donatien	0:632c9925f013	764	while (pcb != NULL) {
donatien	0:632c9925f013	765	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: processing active pcb\n"));
donatien	0:632c9925f013	766	LWIP_ASSERT("tcp_slowtmr: active pcb->state != CLOSED\n", pcb->state != CLOSED);
donatien	0:632c9925f013	767	LWIP_ASSERT("tcp_slowtmr: active pcb->state != LISTEN\n", pcb->state != LISTEN);
donatien	0:632c9925f013	768	LWIP_ASSERT("tcp_slowtmr: active pcb->state != TIME-WAIT\n", pcb->state != TIME_WAIT);
donatien	0:632c9925f013	769
donatien	0:632c9925f013	770	pcb_remove = 0;
donatien	0:632c9925f013	771	pcb_reset = 0;
donatien	0:632c9925f013	772
donatien	0:632c9925f013	773	if (pcb->state == SYN_SENT && pcb->nrtx == TCP_SYNMAXRTX) {
donatien	0:632c9925f013	774	++pcb_remove;
donatien	0:632c9925f013	775	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max SYN retries reached\n"));
donatien	0:632c9925f013	776	}
donatien	0:632c9925f013	777	else if (pcb->nrtx == TCP_MAXRTX) {
donatien	0:632c9925f013	778	++pcb_remove;
donatien	0:632c9925f013	779	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max DATA retries reached\n"));
donatien	0:632c9925f013	780	} else {
donatien	0:632c9925f013	781	if (pcb->persist_backoff > 0) {
donatien	0:632c9925f013	782	/* If snd_wnd is zero, use persist timer to send 1 byte probes
donatien	0:632c9925f013	783	* instead of using the standard retransmission mechanism. */
donatien	0:632c9925f013	784	pcb->persist_cnt++;
donatien	0:632c9925f013	785	if (pcb->persist_cnt >= tcp_persist_backoff[pcb->persist_backoff-1]) {
donatien	0:632c9925f013	786	pcb->persist_cnt = 0;
donatien	0:632c9925f013	787	if (pcb->persist_backoff < sizeof(tcp_persist_backoff)) {
donatien	0:632c9925f013	788	pcb->persist_backoff++;
donatien	0:632c9925f013	789	}
donatien	0:632c9925f013	790	tcp_zero_window_probe(pcb);
donatien	0:632c9925f013	791	}
donatien	0:632c9925f013	792	} else {
donatien	0:632c9925f013	793	/* Increase the retransmission timer if it is running */
donatien	0:632c9925f013	794	if(pcb->rtime >= 0)
donatien	0:632c9925f013	795	++pcb->rtime;
donatien	0:632c9925f013	796
donatien	0:632c9925f013	797	if (pcb->unacked != NULL && pcb->rtime >= pcb->rto) {
donatien	0:632c9925f013	798	/* Time for a retransmission. */
donatien	0:632c9925f013	799	LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_slowtmr: rtime %"S16_F
donatien	0:632c9925f013	800	" pcb->rto %"S16_F"\n",
donatien	0:632c9925f013	801	pcb->rtime, pcb->rto));
donatien	0:632c9925f013	802
donatien	0:632c9925f013	803	/* Double retransmission time-out unless we are trying to
donatien	0:632c9925f013	804	* connect to somebody (i.e., we are in SYN_SENT). */
donatien	0:632c9925f013	805	if (pcb->state != SYN_SENT) {
donatien	0:632c9925f013	806	pcb->rto = ((pcb->sa >> 3) + pcb->sv) << tcp_backoff[pcb->nrtx];
donatien	0:632c9925f013	807	}
donatien	0:632c9925f013	808
donatien	0:632c9925f013	809	/* Reset the retransmission timer. */
donatien	0:632c9925f013	810	pcb->rtime = 0;
donatien	0:632c9925f013	811
donatien	0:632c9925f013	812	/* Reduce congestion window and ssthresh. */
donatien	0:632c9925f013	813	eff_wnd = LWIP_MIN(pcb->cwnd, pcb->snd_wnd);
donatien	0:632c9925f013	814	pcb->ssthresh = eff_wnd >> 1;
donatien	0:632c9925f013	815	if (pcb->ssthresh < (pcb->mss << 1)) {
donatien	0:632c9925f013	816	pcb->ssthresh = (pcb->mss << 1);
donatien	0:632c9925f013	817	}
donatien	0:632c9925f013	818	pcb->cwnd = pcb->mss;
donatien	0:632c9925f013	819	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: cwnd %"U16_F
donatien	0:632c9925f013	820	" ssthresh %"U16_F"\n",
donatien	0:632c9925f013	821	pcb->cwnd, pcb->ssthresh));
donatien	0:632c9925f013	822
donatien	0:632c9925f013	823	/* The following needs to be called AFTER cwnd is set to one
donatien	0:632c9925f013	824	mss - STJ */
donatien	0:632c9925f013	825	tcp_rexmit_rto(pcb);
donatien	0:632c9925f013	826	}
donatien	0:632c9925f013	827	}
donatien	0:632c9925f013	828	}
donatien	0:632c9925f013	829	/* Check if this PCB has stayed too long in FIN-WAIT-2 */
donatien	0:632c9925f013	830	if (pcb->state == FIN_WAIT_2) {
donatien	0:632c9925f013	831	if ((u32_t)(tcp_ticks - pcb->tmr) >
donatien	0:632c9925f013	832	TCP_FIN_WAIT_TIMEOUT / TCP_SLOW_INTERVAL) {
donatien	0:632c9925f013	833	++pcb_remove;
donatien	0:632c9925f013	834	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in FIN-WAIT-2\n"));
donatien	0:632c9925f013	835	}
donatien	0:632c9925f013	836	}
donatien	0:632c9925f013	837
donatien	0:632c9925f013	838	/* Check if KEEPALIVE should be sent */
donatien	0:632c9925f013	839	if((pcb->so_options & SOF_KEEPALIVE) &&
donatien	0:632c9925f013	840	((pcb->state == ESTABLISHED) \|\|
donatien	0:632c9925f013	841	(pcb->state == CLOSE_WAIT))) {
donatien	0:632c9925f013	842	#if LWIP_TCP_KEEPALIVE
donatien	0:632c9925f013	843	if((u32_t)(tcp_ticks - pcb->tmr) >
donatien	0:632c9925f013	844	(pcb->keep_idle + (pcb->keep_cnt*pcb->keep_intvl))
donatien	0:632c9925f013	845	/ TCP_SLOW_INTERVAL)
donatien	0:632c9925f013	846	#else
donatien	0:632c9925f013	847	if((u32_t)(tcp_ticks - pcb->tmr) >
donatien	0:632c9925f013	848	(pcb->keep_idle + TCP_MAXIDLE) / TCP_SLOW_INTERVAL)
donatien	0:632c9925f013	849	#endif /* LWIP_TCP_KEEPALIVE */
donatien	0:632c9925f013	850	{
donatien	0:632c9925f013	851	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: KEEPALIVE timeout. Aborting connection to %"U16_F".%"U16_F".%"U16_F".%"U16_F".\n",
donatien	0:632c9925f013	852	ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip),
donatien	0:632c9925f013	853	ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip)));
donatien	0:632c9925f013	854
donatien	0:632c9925f013	855	++pcb_remove;
donatien	0:632c9925f013	856	++pcb_reset;
donatien	0:632c9925f013	857	}
donatien	0:632c9925f013	858	#if LWIP_TCP_KEEPALIVE
donatien	0:632c9925f013	859	else if((u32_t)(tcp_ticks - pcb->tmr) >
donatien	0:632c9925f013	860	(pcb->keep_idle + pcb->keep_cnt_sent * pcb->keep_intvl)
donatien	0:632c9925f013	861	/ TCP_SLOW_INTERVAL)
donatien	0:632c9925f013	862	#else
donatien	0:632c9925f013	863	else if((u32_t)(tcp_ticks - pcb->tmr) >
donatien	0:632c9925f013	864	(pcb->keep_idle + pcb->keep_cnt_sent * TCP_KEEPINTVL_DEFAULT)
donatien	0:632c9925f013	865	/ TCP_SLOW_INTERVAL)
donatien	0:632c9925f013	866	#endif /* LWIP_TCP_KEEPALIVE */
donatien	0:632c9925f013	867	{
donatien	0:632c9925f013	868	tcp_keepalive(pcb);
donatien	0:632c9925f013	869	pcb->keep_cnt_sent++;
donatien	0:632c9925f013	870	}
donatien	0:632c9925f013	871	}
donatien	0:632c9925f013	872
donatien	0:632c9925f013	873	/* If this PCB has queued out of sequence data, but has been
donatien	0:632c9925f013	874	inactive for too long, will drop the data (it will eventually
donatien	0:632c9925f013	875	be retransmitted). */
donatien	0:632c9925f013	876	#if TCP_QUEUE_OOSEQ
donatien	0:632c9925f013	877	if (pcb->ooseq != NULL &&
donatien	0:632c9925f013	878	(u32_t)tcp_ticks - pcb->tmr >= pcb->rto * TCP_OOSEQ_TIMEOUT) {
donatien	0:632c9925f013	879	tcp_segs_free(pcb->ooseq);
donatien	0:632c9925f013	880	pcb->ooseq = NULL;
donatien	0:632c9925f013	881	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: dropping OOSEQ queued data\n"));
donatien	0:632c9925f013	882	}
donatien	0:632c9925f013	883	#endif /* TCP_QUEUE_OOSEQ */
donatien	0:632c9925f013	884
donatien	0:632c9925f013	885	/* Check if this PCB has stayed too long in SYN-RCVD */
donatien	0:632c9925f013	886	if (pcb->state == SYN_RCVD) {
donatien	0:632c9925f013	887	if ((u32_t)(tcp_ticks - pcb->tmr) >
donatien	0:632c9925f013	888	TCP_SYN_RCVD_TIMEOUT / TCP_SLOW_INTERVAL) {
donatien	0:632c9925f013	889	++pcb_remove;
donatien	0:632c9925f013	890	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in SYN-RCVD\n"));
donatien	0:632c9925f013	891	}
donatien	0:632c9925f013	892	}
donatien	0:632c9925f013	893
donatien	0:632c9925f013	894	/* Check if this PCB has stayed too long in LAST-ACK */
donatien	0:632c9925f013	895	if (pcb->state == LAST_ACK) {
donatien	0:632c9925f013	896	if ((u32_t)(tcp_ticks - pcb->tmr) > 2 * TCP_MSL / TCP_SLOW_INTERVAL) {
donatien	0:632c9925f013	897	++pcb_remove;
donatien	0:632c9925f013	898	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in LAST-ACK\n"));
donatien	0:632c9925f013	899	}
donatien	0:632c9925f013	900	}
donatien	0:632c9925f013	901
donatien	0:632c9925f013	902	/* If the PCB should be removed, do it. */
donatien	0:632c9925f013	903	if (pcb_remove) {
donatien	0:632c9925f013	904	tcp_pcb_purge(pcb);
donatien	0:632c9925f013	905	/* Remove PCB from tcp_active_pcbs list. */
donatien	0:632c9925f013	906	if (prev != NULL) {
donatien	0:632c9925f013	907	LWIP_ASSERT("tcp_slowtmr: middle tcp != tcp_active_pcbs", pcb != tcp_active_pcbs);
donatien	0:632c9925f013	908	prev->next = pcb->next;
donatien	0:632c9925f013	909	} else {
donatien	0:632c9925f013	910	/* This PCB was the first. */
donatien	0:632c9925f013	911	LWIP_ASSERT("tcp_slowtmr: first pcb == tcp_active_pcbs", tcp_active_pcbs == pcb);
donatien	0:632c9925f013	912	tcp_active_pcbs = pcb->next;
donatien	0:632c9925f013	913	}
donatien	0:632c9925f013	914
donatien	0:632c9925f013	915	TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_ABRT);
donatien	0:632c9925f013	916	if (pcb_reset) {
donatien	0:632c9925f013	917	tcp_rst(pcb->snd_nxt, pcb->rcv_nxt, &pcb->local_ip, &pcb->remote_ip,
donatien	0:632c9925f013	918	pcb->local_port, pcb->remote_port);
donatien	0:632c9925f013	919	}
donatien	0:632c9925f013	920
donatien	0:632c9925f013	921	pcb2 = pcb->next;
donatien	0:632c9925f013	922	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	923	pcb = pcb2;
donatien	0:632c9925f013	924	} else {
donatien	0:632c9925f013	925	/* get the 'next' element now and work with 'prev' below (in case of abort) */
donatien	0:632c9925f013	926	prev = pcb;
donatien	0:632c9925f013	927	pcb = pcb->next;
donatien	0:632c9925f013	928
donatien	0:632c9925f013	929	/* We check if we should poll the connection. */
donatien	0:632c9925f013	930	++prev->polltmr;
donatien	0:632c9925f013	931	if (prev->polltmr >= prev->pollinterval) {
donatien	0:632c9925f013	932	prev->polltmr = 0;
donatien	0:632c9925f013	933	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: polling application\n"));
donatien	0:632c9925f013	934	TCP_EVENT_POLL(prev, err);
donatien	0:632c9925f013	935	/* if err == ERR_ABRT, 'prev' is already deallocated */
donatien	0:632c9925f013	936	if (err == ERR_OK) {
donatien	0:632c9925f013	937	tcp_output(prev);
donatien	0:632c9925f013	938	}
donatien	0:632c9925f013	939	}
donatien	0:632c9925f013	940	}
donatien	0:632c9925f013	941	}
donatien	0:632c9925f013	942
donatien	0:632c9925f013	943
donatien	0:632c9925f013	944	/* Steps through all of the TIME-WAIT PCBs. */
donatien	0:632c9925f013	945	prev = NULL;
donatien	0:632c9925f013	946	pcb = tcp_tw_pcbs;
donatien	0:632c9925f013	947	while (pcb != NULL) {
donatien	0:632c9925f013	948	LWIP_ASSERT("tcp_slowtmr: TIME-WAIT pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
donatien	0:632c9925f013	949	pcb_remove = 0;
donatien	0:632c9925f013	950
donatien	0:632c9925f013	951	/* Check if this PCB has stayed long enough in TIME-WAIT */
donatien	0:632c9925f013	952	if ((u32_t)(tcp_ticks - pcb->tmr) > 2 * TCP_MSL / TCP_SLOW_INTERVAL) {
donatien	0:632c9925f013	953	++pcb_remove;
donatien	0:632c9925f013	954	}
donatien	0:632c9925f013	955
donatien	0:632c9925f013	956
donatien	0:632c9925f013	957
donatien	0:632c9925f013	958	/* If the PCB should be removed, do it. */
donatien	0:632c9925f013	959	if (pcb_remove) {
donatien	0:632c9925f013	960	tcp_pcb_purge(pcb);
donatien	0:632c9925f013	961	/* Remove PCB from tcp_tw_pcbs list. */
donatien	0:632c9925f013	962	if (prev != NULL) {
donatien	0:632c9925f013	963	LWIP_ASSERT("tcp_slowtmr: middle tcp != tcp_tw_pcbs", pcb != tcp_tw_pcbs);
donatien	0:632c9925f013	964	prev->next = pcb->next;
donatien	0:632c9925f013	965	} else {
donatien	0:632c9925f013	966	/* This PCB was the first. */
donatien	0:632c9925f013	967	LWIP_ASSERT("tcp_slowtmr: first pcb == tcp_tw_pcbs", tcp_tw_pcbs == pcb);
donatien	0:632c9925f013	968	tcp_tw_pcbs = pcb->next;
donatien	0:632c9925f013	969	}
donatien	0:632c9925f013	970	pcb2 = pcb->next;
donatien	0:632c9925f013	971	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	972	pcb = pcb2;
donatien	0:632c9925f013	973	} else {
donatien	0:632c9925f013	974	prev = pcb;
donatien	0:632c9925f013	975	pcb = pcb->next;
donatien	0:632c9925f013	976	}
donatien	0:632c9925f013	977	}
donatien	0:632c9925f013	978	}
donatien	0:632c9925f013	979
donatien	0:632c9925f013	980	/**
donatien	0:632c9925f013	981	* Is called every TCP_FAST_INTERVAL (250 ms) and process data previously
donatien	0:632c9925f013	982	* "refused" by upper layer (application) and sends delayed ACKs.
donatien	0:632c9925f013	983	*
donatien	0:632c9925f013	984	* Automatically called from tcp_tmr().
donatien	0:632c9925f013	985	*/
donatien	0:632c9925f013	986	void
donatien	0:632c9925f013	987	tcp_fasttmr(void)
donatien	0:632c9925f013	988	{
donatien	0:632c9925f013	989	struct tcp_pcb *pcb = tcp_active_pcbs;
donatien	0:632c9925f013	990
donatien	0:632c9925f013	991	while(pcb != NULL) {
donatien	0:632c9925f013	992	struct tcp_pcb *next = pcb->next;
donatien	0:632c9925f013	993	/* If there is data which was previously "refused" by upper layer */
donatien	0:632c9925f013	994	if (pcb->refused_data != NULL) {
donatien	0:632c9925f013	995	/* Notify again application with data previously received. */
donatien	0:632c9925f013	996	err_t err;
donatien	0:632c9925f013	997	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_fasttmr: notify kept packet\n"));
donatien	0:632c9925f013	998	TCP_EVENT_RECV(pcb, pcb->refused_data, ERR_OK, err);
donatien	0:632c9925f013	999	if (err == ERR_OK) {
donatien	0:632c9925f013	1000	pcb->refused_data = NULL;
donatien	0:632c9925f013	1001	} else if (err == ERR_ABRT) {
donatien	0:632c9925f013	1002	/* if err == ERR_ABRT, 'pcb' is already deallocated */
donatien	0:632c9925f013	1003	pcb = NULL;
donatien	0:632c9925f013	1004	}
donatien	0:632c9925f013	1005	}
donatien	0:632c9925f013	1006
donatien	0:632c9925f013	1007	/* send delayed ACKs */
donatien	0:632c9925f013	1008	if (pcb && (pcb->flags & TF_ACK_DELAY)) {
donatien	0:632c9925f013	1009	LWIP_DEBUGF(TCP_DEBUG, ("tcp_fasttmr: delayed ACK\n"));
donatien	0:632c9925f013	1010	tcp_ack_now(pcb);
donatien	0:632c9925f013	1011	tcp_output(pcb);
donatien	0:632c9925f013	1012	pcb->flags &= ~(TF_ACK_DELAY \| TF_ACK_NOW);
donatien	0:632c9925f013	1013	}
donatien	0:632c9925f013	1014
donatien	0:632c9925f013	1015	pcb = next;
donatien	0:632c9925f013	1016	}
donatien	0:632c9925f013	1017	}
donatien	0:632c9925f013	1018
donatien	0:632c9925f013	1019	/**
donatien	0:632c9925f013	1020	* Deallocates a list of TCP segments (tcp_seg structures).
donatien	0:632c9925f013	1021	*
donatien	0:632c9925f013	1022	* @param seg tcp_seg list of TCP segments to free
donatien	0:632c9925f013	1023	*/
donatien	0:632c9925f013	1024	void
donatien	0:632c9925f013	1025	tcp_segs_free(struct tcp_seg *seg)
donatien	0:632c9925f013	1026	{
donatien	0:632c9925f013	1027	while (seg != NULL) {
donatien	0:632c9925f013	1028	struct tcp_seg *next = seg->next;
donatien	0:632c9925f013	1029	tcp_seg_free(seg);
donatien	0:632c9925f013	1030	seg = next;
donatien	0:632c9925f013	1031	}
donatien	0:632c9925f013	1032	}
donatien	0:632c9925f013	1033
donatien	0:632c9925f013	1034	/**
donatien	0:632c9925f013	1035	* Frees a TCP segment (tcp_seg structure).
donatien	0:632c9925f013	1036	*
donatien	0:632c9925f013	1037	* @param seg single tcp_seg to free
donatien	0:632c9925f013	1038	*/
donatien	0:632c9925f013	1039	void
donatien	0:632c9925f013	1040	tcp_seg_free(struct tcp_seg *seg)
donatien	0:632c9925f013	1041	{
donatien	0:632c9925f013	1042	if (seg != NULL) {
donatien	0:632c9925f013	1043	if (seg->p != NULL) {
donatien	0:632c9925f013	1044	pbuf_free(seg->p);
donatien	0:632c9925f013	1045	#if TCP_DEBUG
donatien	0:632c9925f013	1046	seg->p = NULL;
donatien	0:632c9925f013	1047	#endif /* TCP_DEBUG */
donatien	0:632c9925f013	1048	}
donatien	0:632c9925f013	1049	memp_free(MEMP_TCP_SEG, seg);
donatien	0:632c9925f013	1050	}
donatien	0:632c9925f013	1051	}
donatien	0:632c9925f013	1052
donatien	0:632c9925f013	1053	/**
donatien	0:632c9925f013	1054	* Sets the priority of a connection.
donatien	0:632c9925f013	1055	*
donatien	0:632c9925f013	1056	* @param pcb the tcp_pcb to manipulate
donatien	0:632c9925f013	1057	* @param prio new priority
donatien	0:632c9925f013	1058	*/
donatien	0:632c9925f013	1059	void
donatien	0:632c9925f013	1060	tcp_setprio(struct tcp_pcb *pcb, u8_t prio)
donatien	0:632c9925f013	1061	{
donatien	0:632c9925f013	1062	pcb->prio = prio;
donatien	0:632c9925f013	1063	}
donatien	5:dd63a1e02b1b	1064
donatien	0:632c9925f013	1065	#if TCP_QUEUE_OOSEQ
donatien	0:632c9925f013	1066	/**
donatien	0:632c9925f013	1067	* Returns a copy of the given TCP segment.
donatien	0:632c9925f013	1068	* The pbuf and data are not copied, only the pointers
donatien	0:632c9925f013	1069	*
donatien	0:632c9925f013	1070	* @param seg the old tcp_seg
donatien	0:632c9925f013	1071	* @return a copy of seg
donatien	0:632c9925f013	1072	*/
donatien	0:632c9925f013	1073	struct tcp_seg *
donatien	0:632c9925f013	1074	tcp_seg_copy(struct tcp_seg *seg)
donatien	0:632c9925f013	1075	{
donatien	0:632c9925f013	1076	struct tcp_seg *cseg;
donatien	0:632c9925f013	1077
donatien	0:632c9925f013	1078	cseg = (struct tcp_seg *)memp_malloc(MEMP_TCP_SEG);
donatien	0:632c9925f013	1079	if (cseg == NULL) {
donatien	0:632c9925f013	1080	return NULL;
donatien	0:632c9925f013	1081	}
donatien	0:632c9925f013	1082	SMEMCPY((u8_t )cseg, (const u8_t )seg, sizeof(struct tcp_seg));
donatien	0:632c9925f013	1083	pbuf_ref(cseg->p);
donatien	0:632c9925f013	1084	return cseg;
donatien	0:632c9925f013	1085	}
donatien	5:dd63a1e02b1b	1086	#endif /* TCP_QUEUE_OOSEQ */
donatien	0:632c9925f013	1087
donatien	0:632c9925f013	1088	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	1089	/**
donatien	0:632c9925f013	1090	* Default receive callback that is called if the user didn't register
donatien	0:632c9925f013	1091	* a recv callback for the pcb.
donatien	0:632c9925f013	1092	*/
donatien	0:632c9925f013	1093	err_t
donatien	0:632c9925f013	1094	tcp_recv_null(void arg, struct tcp_pcb pcb, struct pbuf *p, err_t err)
donatien	0:632c9925f013	1095	{
donatien	0:632c9925f013	1096	LWIP_UNUSED_ARG(arg);
donatien	0:632c9925f013	1097	if (p != NULL) {
donatien	0:632c9925f013	1098	tcp_recved(pcb, p->tot_len);
donatien	0:632c9925f013	1099	pbuf_free(p);
donatien	0:632c9925f013	1100	} else if (err == ERR_OK) {
donatien	0:632c9925f013	1101	return tcp_close(pcb);
donatien	0:632c9925f013	1102	}
donatien	0:632c9925f013	1103	return ERR_OK;
donatien	0:632c9925f013	1104	}
donatien	0:632c9925f013	1105	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	1106
donatien	0:632c9925f013	1107	/**
donatien	0:632c9925f013	1108	* Kills the oldest active connection that has lower priority than prio.
donatien	0:632c9925f013	1109	*
donatien	0:632c9925f013	1110	* @param prio minimum priority
donatien	0:632c9925f013	1111	*/
donatien	0:632c9925f013	1112	static void
donatien	0:632c9925f013	1113	tcp_kill_prio(u8_t prio)
donatien	0:632c9925f013	1114	{
donatien	0:632c9925f013	1115	struct tcp_pcb pcb, inactive;
donatien	0:632c9925f013	1116	u32_t inactivity;
donatien	0:632c9925f013	1117	u8_t mprio;
donatien	0:632c9925f013	1118
donatien	0:632c9925f013	1119
donatien	0:632c9925f013	1120	mprio = TCP_PRIO_MAX;
donatien	0:632c9925f013	1121
donatien	0:632c9925f013	1122	/* We kill the oldest active connection that has lower priority than prio. */
donatien	0:632c9925f013	1123	inactivity = 0;
donatien	0:632c9925f013	1124	inactive = NULL;
donatien	0:632c9925f013	1125	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1126	if (pcb->prio <= prio &&
donatien	0:632c9925f013	1127	pcb->prio <= mprio &&
donatien	0:632c9925f013	1128	(u32_t)(tcp_ticks - pcb->tmr) >= inactivity) {
donatien	0:632c9925f013	1129	inactivity = tcp_ticks - pcb->tmr;
donatien	0:632c9925f013	1130	inactive = pcb;
donatien	0:632c9925f013	1131	mprio = pcb->prio;
donatien	0:632c9925f013	1132	}
donatien	0:632c9925f013	1133	}
donatien	0:632c9925f013	1134	if (inactive != NULL) {
donatien	0:632c9925f013	1135	LWIP_DEBUGF(TCP_DEBUG, ("tcp_kill_prio: killing oldest PCB %p (%"S32_F")\n",
donatien	0:632c9925f013	1136	(void *)inactive, inactivity));
donatien	0:632c9925f013	1137	tcp_abort(inactive);
donatien	5:dd63a1e02b1b	1138	}
donatien	0:632c9925f013	1139	}
donatien	0:632c9925f013	1140
donatien	0:632c9925f013	1141	/**
donatien	0:632c9925f013	1142	* Kills the oldest connection that is in TIME_WAIT state.
donatien	0:632c9925f013	1143	* Called from tcp_alloc() if no more connections are available.
donatien	0:632c9925f013	1144	*/
donatien	0:632c9925f013	1145	static void
donatien	0:632c9925f013	1146	tcp_kill_timewait(void)
donatien	0:632c9925f013	1147	{
donatien	0:632c9925f013	1148	struct tcp_pcb pcb, inactive;
donatien	0:632c9925f013	1149	u32_t inactivity;
donatien	0:632c9925f013	1150
donatien	0:632c9925f013	1151	inactivity = 0;
donatien	0:632c9925f013	1152	inactive = NULL;
donatien	0:632c9925f013	1153	/* Go through the list of TIME_WAIT pcbs and get the oldest pcb. */
donatien	0:632c9925f013	1154	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1155	if ((u32_t)(tcp_ticks - pcb->tmr) >= inactivity) {
donatien	0:632c9925f013	1156	inactivity = tcp_ticks - pcb->tmr;
donatien	0:632c9925f013	1157	inactive = pcb;
donatien	0:632c9925f013	1158	}
donatien	0:632c9925f013	1159	}
donatien	0:632c9925f013	1160	if (inactive != NULL) {
donatien	0:632c9925f013	1161	LWIP_DEBUGF(TCP_DEBUG, ("tcp_kill_timewait: killing oldest TIME-WAIT PCB %p (%"S32_F")\n",
donatien	0:632c9925f013	1162	(void *)inactive, inactivity));
donatien	0:632c9925f013	1163	tcp_abort(inactive);
donatien	5:dd63a1e02b1b	1164	}
donatien	0:632c9925f013	1165	}
donatien	0:632c9925f013	1166
donatien	0:632c9925f013	1167	/**
donatien	0:632c9925f013	1168	* Allocate a new tcp_pcb structure.
donatien	0:632c9925f013	1169	*
donatien	0:632c9925f013	1170	* @param prio priority for the new pcb
donatien	0:632c9925f013	1171	* @return a new tcp_pcb that initially is in state CLOSED
donatien	0:632c9925f013	1172	*/
donatien	0:632c9925f013	1173	struct tcp_pcb *
donatien	0:632c9925f013	1174	tcp_alloc(u8_t prio)
donatien	0:632c9925f013	1175	{
donatien	0:632c9925f013	1176	struct tcp_pcb *pcb;
donatien	0:632c9925f013	1177	u32_t iss;
donatien	0:632c9925f013	1178
donatien	0:632c9925f013	1179	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
donatien	0:632c9925f013	1180	if (pcb == NULL) {
donatien	0:632c9925f013	1181	/* Try killing oldest connection in TIME-WAIT. */
donatien	0:632c9925f013	1182	LWIP_DEBUGF(TCP_DEBUG, ("tcp_alloc: killing off oldest TIME-WAIT connection\n"));
donatien	0:632c9925f013	1183	tcp_kill_timewait();
donatien	0:632c9925f013	1184	/* Try to allocate a tcp_pcb again. */
donatien	0:632c9925f013	1185	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
donatien	0:632c9925f013	1186	if (pcb == NULL) {
donatien	0:632c9925f013	1187	/* Try killing active connections with lower priority than the new one. */
donatien	0:632c9925f013	1188	LWIP_DEBUGF(TCP_DEBUG, ("tcp_alloc: killing connection with prio lower than %d\n", prio));
donatien	0:632c9925f013	1189	tcp_kill_prio(prio);
donatien	0:632c9925f013	1190	/* Try to allocate a tcp_pcb again. */
donatien	0:632c9925f013	1191	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
donatien	0:632c9925f013	1192	if (pcb != NULL) {
donatien	0:632c9925f013	1193	/* adjust err stats: memp_malloc failed twice before */
donatien	0:632c9925f013	1194	MEMP_STATS_DEC(err, MEMP_TCP_PCB);
donatien	0:632c9925f013	1195	}
donatien	0:632c9925f013	1196	}
donatien	0:632c9925f013	1197	if (pcb != NULL) {
donatien	0:632c9925f013	1198	/* adjust err stats: timewait PCB was freed above */
donatien	0:632c9925f013	1199	MEMP_STATS_DEC(err, MEMP_TCP_PCB);
donatien	0:632c9925f013	1200	}
donatien	0:632c9925f013	1201	}
donatien	0:632c9925f013	1202	if (pcb != NULL) {
donatien	0:632c9925f013	1203	memset(pcb, 0, sizeof(struct tcp_pcb));
donatien	0:632c9925f013	1204	pcb->prio = prio;
donatien	0:632c9925f013	1205	pcb->snd_buf = TCP_SND_BUF;
donatien	0:632c9925f013	1206	pcb->snd_queuelen = 0;
donatien	0:632c9925f013	1207	pcb->rcv_wnd = TCP_WND;
donatien	0:632c9925f013	1208	pcb->rcv_ann_wnd = TCP_WND;
donatien	0:632c9925f013	1209	pcb->tos = 0;
donatien	0:632c9925f013	1210	pcb->ttl = TCP_TTL;
donatien	0:632c9925f013	1211	/* As initial send MSS, we use TCP_MSS but limit it to 536.
donatien	0:632c9925f013	1212	The send MSS is updated when an MSS option is received. */
donatien	0:632c9925f013	1213	pcb->mss = (TCP_MSS > 536) ? 536 : TCP_MSS;
donatien	0:632c9925f013	1214	pcb->rto = 3000 / TCP_SLOW_INTERVAL;
donatien	0:632c9925f013	1215	pcb->sa = 0;
donatien	0:632c9925f013	1216	pcb->sv = 3000 / TCP_SLOW_INTERVAL;
donatien	0:632c9925f013	1217	pcb->rtime = -1;
donatien	0:632c9925f013	1218	pcb->cwnd = 1;
donatien	0:632c9925f013	1219	iss = tcp_next_iss();
donatien	0:632c9925f013	1220	pcb->snd_wl2 = iss;
donatien	0:632c9925f013	1221	pcb->snd_nxt = iss;
donatien	0:632c9925f013	1222	pcb->lastack = iss;
donatien	0:632c9925f013	1223	pcb->snd_lbb = iss;
donatien	0:632c9925f013	1224	pcb->tmr = tcp_ticks;
donatien	5:dd63a1e02b1b	1225
donatien	5:dd63a1e02b1b	1226	LWIP_DEBUGF(TCP_DEBUG, ("tcp_alloc: tcp_ticks=%"U32_F" iss=%"U32_F"\n", tcp_ticks, iss));
donatien	0:632c9925f013	1227
donatien	0:632c9925f013	1228	pcb->polltmr = 0;
donatien	0:632c9925f013	1229
donatien	0:632c9925f013	1230	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	1231	pcb->recv = tcp_recv_null;
donatien	0:632c9925f013	1232	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	1233
donatien	0:632c9925f013	1234	/* Init KEEPALIVE timer */
donatien	0:632c9925f013	1235	pcb->keep_idle = TCP_KEEPIDLE_DEFAULT;
donatien	0:632c9925f013	1236
donatien	0:632c9925f013	1237	#if LWIP_TCP_KEEPALIVE
donatien	0:632c9925f013	1238	pcb->keep_intvl = TCP_KEEPINTVL_DEFAULT;
donatien	0:632c9925f013	1239	pcb->keep_cnt = TCP_KEEPCNT_DEFAULT;
donatien	0:632c9925f013	1240	#endif /* LWIP_TCP_KEEPALIVE */
donatien	0:632c9925f013	1241
donatien	0:632c9925f013	1242	pcb->keep_cnt_sent = 0;
donatien	0:632c9925f013	1243	}
donatien	0:632c9925f013	1244	return pcb;
donatien	0:632c9925f013	1245	}
donatien	0:632c9925f013	1246
donatien	0:632c9925f013	1247	/**
donatien	0:632c9925f013	1248	* Creates a new TCP protocol control block but doesn't place it on
donatien	0:632c9925f013	1249	* any of the TCP PCB lists.
donatien	0:632c9925f013	1250	* The pcb is not put on any list until binding using tcp_bind().
donatien	0:632c9925f013	1251	*
donatien	0:632c9925f013	1252	* @internal: Maybe there should be a idle TCP PCB list where these
donatien	0:632c9925f013	1253	* PCBs are put on. Port reservation using tcp_bind() is implemented but
donatien	0:632c9925f013	1254	* allocated pcbs that are not bound can't be killed automatically if wanting
donatien	0:632c9925f013	1255	* to allocate a pcb with higher prio (@see tcp_kill_prio())
donatien	0:632c9925f013	1256	*
donatien	0:632c9925f013	1257	* @return a new tcp_pcb that initially is in state CLOSED
donatien	0:632c9925f013	1258	*/
donatien	0:632c9925f013	1259	struct tcp_pcb *
donatien	0:632c9925f013	1260	tcp_new(void)
donatien	0:632c9925f013	1261	{
donatien	0:632c9925f013	1262	return tcp_alloc(TCP_PRIO_NORMAL);
donatien	0:632c9925f013	1263	}
donatien	0:632c9925f013	1264
donatien	0:632c9925f013	1265	/**
donatien	0:632c9925f013	1266	* Used to specify the argument that should be passed callback
donatien	0:632c9925f013	1267	* functions.
donatien	0:632c9925f013	1268	*
donatien	0:632c9925f013	1269	* @param pcb tcp_pcb to set the callback argument
donatien	0:632c9925f013	1270	* @param arg void pointer argument to pass to callback functions
donatien	0:632c9925f013	1271	*/
donatien	0:632c9925f013	1272	void
donatien	0:632c9925f013	1273	tcp_arg(struct tcp_pcb pcb, void arg)
donatien	0:632c9925f013	1274	{
donatien	0:632c9925f013	1275	pcb->callback_arg = arg;
donatien	0:632c9925f013	1276	}
donatien	0:632c9925f013	1277	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	1278
donatien	0:632c9925f013	1279	/**
donatien	0:632c9925f013	1280	* Used to specify the function that should be called when a TCP
donatien	0:632c9925f013	1281	* connection receives data.
donatien	0:632c9925f013	1282	*
donatien	0:632c9925f013	1283	* @param pcb tcp_pcb to set the recv callback
donatien	0:632c9925f013	1284	* @param recv callback function to call for this pcb when data is received
donatien	0:632c9925f013	1285	*/
donatien	0:632c9925f013	1286	void
donatien	0:632c9925f013	1287	tcp_recv(struct tcp_pcb *pcb, tcp_recv_fn recv)
donatien	0:632c9925f013	1288	{
donatien	0:632c9925f013	1289	pcb->recv = recv;
donatien	0:632c9925f013	1290	}
donatien	0:632c9925f013	1291
donatien	0:632c9925f013	1292	/**
donatien	0:632c9925f013	1293	* Used to specify the function that should be called when TCP data
donatien	0:632c9925f013	1294	* has been successfully delivered to the remote host.
donatien	0:632c9925f013	1295	*
donatien	0:632c9925f013	1296	* @param pcb tcp_pcb to set the sent callback
donatien	0:632c9925f013	1297	* @param sent callback function to call for this pcb when data is successfully sent
donatien	0:632c9925f013	1298	*/
donatien	0:632c9925f013	1299	void
donatien	0:632c9925f013	1300	tcp_sent(struct tcp_pcb *pcb, tcp_sent_fn sent)
donatien	0:632c9925f013	1301	{
donatien	0:632c9925f013	1302	pcb->sent = sent;
donatien	0:632c9925f013	1303	}
donatien	0:632c9925f013	1304
donatien	0:632c9925f013	1305	/**
donatien	0:632c9925f013	1306	* Used to specify the function that should be called when a fatal error
donatien	0:632c9925f013	1307	* has occured on the connection.
donatien	0:632c9925f013	1308	*
donatien	0:632c9925f013	1309	* @param pcb tcp_pcb to set the err callback
donatien	0:632c9925f013	1310	* @param err callback function to call for this pcb when a fatal error
donatien	0:632c9925f013	1311	* has occured on the connection
donatien	0:632c9925f013	1312	*/
donatien	0:632c9925f013	1313	void
donatien	0:632c9925f013	1314	tcp_err(struct tcp_pcb *pcb, tcp_err_fn err)
donatien	0:632c9925f013	1315	{
donatien	0:632c9925f013	1316	pcb->errf = err;
donatien	0:632c9925f013	1317	}
donatien	0:632c9925f013	1318
donatien	0:632c9925f013	1319	/**
donatien	0:632c9925f013	1320	* Used for specifying the function that should be called when a
donatien	0:632c9925f013	1321	* LISTENing connection has been connected to another host.
donatien	0:632c9925f013	1322	*
donatien	0:632c9925f013	1323	* @param pcb tcp_pcb to set the accept callback
donatien	0:632c9925f013	1324	* @param accept callback function to call for this pcb when LISTENing
donatien	0:632c9925f013	1325	* connection has been connected to another host
donatien	0:632c9925f013	1326	*/
donatien	0:632c9925f013	1327	void
donatien	0:632c9925f013	1328	tcp_accept(struct tcp_pcb *pcb, tcp_accept_fn accept)
donatien	0:632c9925f013	1329	{
donatien	0:632c9925f013	1330	pcb->accept = accept;
donatien	0:632c9925f013	1331	}
donatien	0:632c9925f013	1332	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	1333
donatien	0:632c9925f013	1334
donatien	0:632c9925f013	1335	/**
donatien	0:632c9925f013	1336	* Used to specify the function that should be called periodically
donatien	0:632c9925f013	1337	* from TCP. The interval is specified in terms of the TCP coarse
donatien	0:632c9925f013	1338	* timer interval, which is called twice a second.
donatien	0:632c9925f013	1339	*
donatien	0:632c9925f013	1340	*/
donatien	0:632c9925f013	1341	void
donatien	0:632c9925f013	1342	tcp_poll(struct tcp_pcb *pcb, tcp_poll_fn poll, u8_t interval)
donatien	0:632c9925f013	1343	{
donatien	0:632c9925f013	1344	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	1345	pcb->poll = poll;
donatien	5:dd63a1e02b1b	1346	#else /* LWIP_CALLBACK_API */
donatien	5:dd63a1e02b1b	1347	LWIP_UNUSED_ARG(poll);
donatien	0:632c9925f013	1348	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	1349	pcb->pollinterval = interval;
donatien	0:632c9925f013	1350	}
donatien	0:632c9925f013	1351
donatien	0:632c9925f013	1352	/**
donatien	0:632c9925f013	1353	* Purges a TCP PCB. Removes any buffered data and frees the buffer memory
donatien	0:632c9925f013	1354	* (pcb->ooseq, pcb->unsent and pcb->unacked are freed).
donatien	0:632c9925f013	1355	*
donatien	0:632c9925f013	1356	* @param pcb tcp_pcb to purge. The pcb itself is not deallocated!
donatien	0:632c9925f013	1357	*/
donatien	0:632c9925f013	1358	void
donatien	0:632c9925f013	1359	tcp_pcb_purge(struct tcp_pcb *pcb)
donatien	0:632c9925f013	1360	{
donatien	0:632c9925f013	1361	if (pcb->state != CLOSED &&
donatien	0:632c9925f013	1362	pcb->state != TIME_WAIT &&
donatien	0:632c9925f013	1363	pcb->state != LISTEN) {
donatien	0:632c9925f013	1364
donatien	0:632c9925f013	1365	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge\n"));
donatien	0:632c9925f013	1366
donatien	0:632c9925f013	1367	#if TCP_LISTEN_BACKLOG
donatien	0:632c9925f013	1368	if (pcb->state == SYN_RCVD) {
donatien	0:632c9925f013	1369	/* Need to find the corresponding listen_pcb and decrease its accepts_pending */
donatien	0:632c9925f013	1370	struct tcp_pcb_listen *lpcb;
donatien	0:632c9925f013	1371	LWIP_ASSERT("tcp_pcb_purge: pcb->state == SYN_RCVD but tcp_listen_pcbs is NULL",
donatien	0:632c9925f013	1372	tcp_listen_pcbs.listen_pcbs != NULL);
donatien	0:632c9925f013	1373	for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
donatien	0:632c9925f013	1374	if ((lpcb->local_port == pcb->local_port) &&
donatien	0:632c9925f013	1375	(ip_addr_isany(&lpcb->local_ip) \|\|
donatien	0:632c9925f013	1376	ip_addr_cmp(&pcb->local_ip, &lpcb->local_ip))) {
donatien	0:632c9925f013	1377	/* port and address of the listen pcb match the timed-out pcb */
donatien	0:632c9925f013	1378	LWIP_ASSERT("tcp_pcb_purge: listen pcb does not have accepts pending",
donatien	0:632c9925f013	1379	lpcb->accepts_pending > 0);
donatien	0:632c9925f013	1380	lpcb->accepts_pending--;
donatien	0:632c9925f013	1381	break;
donatien	0:632c9925f013	1382	}
donatien	0:632c9925f013	1383	}
donatien	0:632c9925f013	1384	}
donatien	0:632c9925f013	1385	#endif /* TCP_LISTEN_BACKLOG */
donatien	0:632c9925f013	1386
donatien	0:632c9925f013	1387
donatien	0:632c9925f013	1388	if (pcb->refused_data != NULL) {
donatien	0:632c9925f013	1389	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->refused_data\n"));
donatien	0:632c9925f013	1390	pbuf_free(pcb->refused_data);
donatien	0:632c9925f013	1391	pcb->refused_data = NULL;
donatien	0:632c9925f013	1392	}
donatien	0:632c9925f013	1393	if (pcb->unsent != NULL) {
donatien	0:632c9925f013	1394	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: not all data sent\n"));
donatien	0:632c9925f013	1395	}
donatien	0:632c9925f013	1396	if (pcb->unacked != NULL) {
donatien	0:632c9925f013	1397	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->unacked\n"));
donatien	0:632c9925f013	1398	}
donatien	5:dd63a1e02b1b	1399	#if TCP_QUEUE_OOSEQ
donatien	0:632c9925f013	1400	if (pcb->ooseq != NULL) {
donatien	0:632c9925f013	1401	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->ooseq\n"));
donatien	0:632c9925f013	1402	}
donatien	0:632c9925f013	1403	tcp_segs_free(pcb->ooseq);
donatien	0:632c9925f013	1404	pcb->ooseq = NULL;
donatien	0:632c9925f013	1405	#endif /* TCP_QUEUE_OOSEQ */
donatien	0:632c9925f013	1406
donatien	0:632c9925f013	1407	/* Stop the retransmission timer as it will expect data on unacked
donatien	0:632c9925f013	1408	queue if it fires */
donatien	0:632c9925f013	1409	pcb->rtime = -1;
donatien	0:632c9925f013	1410
donatien	0:632c9925f013	1411	tcp_segs_free(pcb->unsent);
donatien	0:632c9925f013	1412	tcp_segs_free(pcb->unacked);
donatien	0:632c9925f013	1413	pcb->unacked = pcb->unsent = NULL;
donatien	0:632c9925f013	1414	#if TCP_OVERSIZE
donatien	0:632c9925f013	1415	pcb->unsent_oversize = 0;
donatien	0:632c9925f013	1416	#endif /* TCP_OVERSIZE */
donatien	0:632c9925f013	1417	}
donatien	0:632c9925f013	1418	}
donatien	0:632c9925f013	1419
donatien	0:632c9925f013	1420	/**
donatien	0:632c9925f013	1421	* Purges the PCB and removes it from a PCB list. Any delayed ACKs are sent first.
donatien	0:632c9925f013	1422	*
donatien	0:632c9925f013	1423	* @param pcblist PCB list to purge.
donatien	0:632c9925f013	1424	* @param pcb tcp_pcb to purge. The pcb itself is NOT deallocated!
donatien	0:632c9925f013	1425	*/
donatien	0:632c9925f013	1426	void
donatien	0:632c9925f013	1427	tcp_pcb_remove(struct tcp_pcb *pcblist, struct tcp_pcb pcb)
donatien	0:632c9925f013	1428	{
donatien	0:632c9925f013	1429	TCP_RMV(pcblist, pcb);
donatien	0:632c9925f013	1430
donatien	0:632c9925f013	1431	tcp_pcb_purge(pcb);
donatien	0:632c9925f013	1432
donatien	0:632c9925f013	1433	/* if there is an outstanding delayed ACKs, send it */
donatien	0:632c9925f013	1434	if (pcb->state != TIME_WAIT &&
donatien	0:632c9925f013	1435	pcb->state != LISTEN &&
donatien	0:632c9925f013	1436	pcb->flags & TF_ACK_DELAY) {
donatien	0:632c9925f013	1437	pcb->flags \|= TF_ACK_NOW;
donatien	0:632c9925f013	1438	tcp_output(pcb);
donatien	0:632c9925f013	1439	}
donatien	0:632c9925f013	1440
donatien	0:632c9925f013	1441	if (pcb->state != LISTEN) {
donatien	0:632c9925f013	1442	LWIP_ASSERT("unsent segments leaking", pcb->unsent == NULL);
donatien	0:632c9925f013	1443	LWIP_ASSERT("unacked segments leaking", pcb->unacked == NULL);
donatien	0:632c9925f013	1444	#if TCP_QUEUE_OOSEQ
donatien	0:632c9925f013	1445	LWIP_ASSERT("ooseq segments leaking", pcb->ooseq == NULL);
donatien	0:632c9925f013	1446	#endif /* TCP_QUEUE_OOSEQ */
donatien	0:632c9925f013	1447	}
donatien	0:632c9925f013	1448
donatien	0:632c9925f013	1449	pcb->state = CLOSED;
donatien	0:632c9925f013	1450
donatien	0:632c9925f013	1451	LWIP_ASSERT("tcp_pcb_remove: tcp_pcbs_sane()", tcp_pcbs_sane());
donatien	0:632c9925f013	1452	}
donatien	0:632c9925f013	1453
donatien	0:632c9925f013	1454	/**
donatien	0:632c9925f013	1455	* Calculates a new initial sequence number for new connections.
donatien	0:632c9925f013	1456	*
donatien	0:632c9925f013	1457	* @return u32_t pseudo random sequence number
donatien	0:632c9925f013	1458	*/
donatien	0:632c9925f013	1459	u32_t
donatien	0:632c9925f013	1460	tcp_next_iss(void)
donatien	0:632c9925f013	1461	{
donatien	0:632c9925f013	1462	static u32_t iss = 6510;
donatien	0:632c9925f013	1463
donatien	0:632c9925f013	1464	iss += tcp_ticks; /* XXX */
donatien	0:632c9925f013	1465	return iss;
donatien	0:632c9925f013	1466	}
donatien	0:632c9925f013	1467
donatien	0:632c9925f013	1468	#if TCP_CALCULATE_EFF_SEND_MSS
donatien	0:632c9925f013	1469	/**
donatien	0:632c9925f013	1470	* Calcluates the effective send mss that can be used for a specific IP address
donatien	0:632c9925f013	1471	* by using ip_route to determin the netif used to send to the address and
donatien	0:632c9925f013	1472	* calculating the minimum of TCP_MSS and that netif's mtu (if set).
donatien	0:632c9925f013	1473	*/
donatien	0:632c9925f013	1474	u16_t
donatien	0:632c9925f013	1475	tcp_eff_send_mss(u16_t sendmss, ip_addr_t *addr)
donatien	0:632c9925f013	1476	{
donatien	0:632c9925f013	1477	u16_t mss_s;
donatien	0:632c9925f013	1478	struct netif *outif;
donatien	0:632c9925f013	1479
donatien	0:632c9925f013	1480	outif = ip_route(addr);
donatien	0:632c9925f013	1481	if ((outif != NULL) && (outif->mtu != 0)) {
donatien	0:632c9925f013	1482	mss_s = outif->mtu - IP_HLEN - TCP_HLEN;
donatien	0:632c9925f013	1483	/* RFC 1122, chap 4.2.2.6:
donatien	0:632c9925f013	1484	* Eff.snd.MSS = min(SendMSS+20, MMS_S) - TCPhdrsize - IPoptionsize
donatien	0:632c9925f013	1485	* We correct for TCP options in tcp_write(), and don't support IP options.
donatien	0:632c9925f013	1486	*/
donatien	0:632c9925f013	1487	sendmss = LWIP_MIN(sendmss, mss_s);
donatien	0:632c9925f013	1488	}
donatien	0:632c9925f013	1489	return sendmss;
donatien	0:632c9925f013	1490	}
donatien	0:632c9925f013	1491	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
donatien	0:632c9925f013	1492
donatien	0:632c9925f013	1493	const char*
donatien	0:632c9925f013	1494	tcp_debug_state_str(enum tcp_state s)
donatien	0:632c9925f013	1495	{
donatien	0:632c9925f013	1496	return tcp_state_str[s];
donatien	0:632c9925f013	1497	}
donatien	0:632c9925f013	1498
donatien	0:632c9925f013	1499	#if TCP_DEBUG \|\| TCP_INPUT_DEBUG \|\| TCP_OUTPUT_DEBUG
donatien	0:632c9925f013	1500	/**
donatien	0:632c9925f013	1501	* Print a tcp header for debugging purposes.
donatien	0:632c9925f013	1502	*
donatien	0:632c9925f013	1503	* @param tcphdr pointer to a struct tcp_hdr
donatien	0:632c9925f013	1504	*/
donatien	0:632c9925f013	1505	void
donatien	0:632c9925f013	1506	tcp_debug_print(struct tcp_hdr *tcphdr)
donatien	0:632c9925f013	1507	{
donatien	0:632c9925f013	1508	LWIP_DEBUGF(TCP_DEBUG, ("TCP header:\n"));
donatien	0:632c9925f013	1509	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
donatien	0:632c9925f013	1510	LWIP_DEBUGF(TCP_DEBUG, ("\| %5"U16_F" \| %5"U16_F" \| (src port, dest port)\n",
donatien	0:632c9925f013	1511	ntohs(tcphdr->src), ntohs(tcphdr->dest)));
donatien	0:632c9925f013	1512	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
donatien	0:632c9925f013	1513	LWIP_DEBUGF(TCP_DEBUG, ("\| %010"U32_F" \| (seq no)\n",
donatien	0:632c9925f013	1514	ntohl(tcphdr->seqno)));
donatien	0:632c9925f013	1515	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
donatien	0:632c9925f013	1516	LWIP_DEBUGF(TCP_DEBUG, ("\| %010"U32_F" \| (ack no)\n",
donatien	0:632c9925f013	1517	ntohl(tcphdr->ackno)));
donatien	0:632c9925f013	1518	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
donatien	0:632c9925f013	1519	LWIP_DEBUGF(TCP_DEBUG, ("\| %2"U16_F" \| \|%"U16_F"%"U16_F"%"U16_F"%"U16_F"%"U16_F"%"U16_F"\| %5"U16_F" \| (hdrlen, flags (",
donatien	0:632c9925f013	1520	TCPH_HDRLEN(tcphdr),
donatien	0:632c9925f013	1521	TCPH_FLAGS(tcphdr) >> 5 & 1,
donatien	0:632c9925f013	1522	TCPH_FLAGS(tcphdr) >> 4 & 1,
donatien	0:632c9925f013	1523	TCPH_FLAGS(tcphdr) >> 3 & 1,
donatien	0:632c9925f013	1524	TCPH_FLAGS(tcphdr) >> 2 & 1,
donatien	0:632c9925f013	1525	TCPH_FLAGS(tcphdr) >> 1 & 1,
donatien	0:632c9925f013	1526	TCPH_FLAGS(tcphdr) & 1,
donatien	0:632c9925f013	1527	ntohs(tcphdr->wnd)));
donatien	0:632c9925f013	1528	tcp_debug_print_flags(TCPH_FLAGS(tcphdr));
donatien	0:632c9925f013	1529	LWIP_DEBUGF(TCP_DEBUG, ("), win)\n"));
donatien	0:632c9925f013	1530	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
donatien	0:632c9925f013	1531	LWIP_DEBUGF(TCP_DEBUG, ("\| 0x%04"X16_F" \| %5"U16_F" \| (chksum, urgp)\n",
donatien	0:632c9925f013	1532	ntohs(tcphdr->chksum), ntohs(tcphdr->urgp)));
donatien	0:632c9925f013	1533	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
donatien	0:632c9925f013	1534	}
donatien	0:632c9925f013	1535
donatien	0:632c9925f013	1536	/**
donatien	0:632c9925f013	1537	* Print a tcp state for debugging purposes.
donatien	0:632c9925f013	1538	*
donatien	0:632c9925f013	1539	* @param s enum tcp_state to print
donatien	0:632c9925f013	1540	*/
donatien	0:632c9925f013	1541	void
donatien	0:632c9925f013	1542	tcp_debug_print_state(enum tcp_state s)
donatien	0:632c9925f013	1543	{
donatien	0:632c9925f013	1544	LWIP_DEBUGF(TCP_DEBUG, ("State: %s\n", tcp_state_str[s]));
donatien	0:632c9925f013	1545	}
donatien	0:632c9925f013	1546
donatien	0:632c9925f013	1547	/**
donatien	0:632c9925f013	1548	* Print tcp flags for debugging purposes.
donatien	0:632c9925f013	1549	*
donatien	0:632c9925f013	1550	* @param flags tcp flags, all active flags are printed
donatien	0:632c9925f013	1551	*/
donatien	0:632c9925f013	1552	void
donatien	0:632c9925f013	1553	tcp_debug_print_flags(u8_t flags)
donatien	0:632c9925f013	1554	{
donatien	0:632c9925f013	1555	if (flags & TCP_FIN) {
donatien	0:632c9925f013	1556	LWIP_DEBUGF(TCP_DEBUG, ("FIN "));
donatien	0:632c9925f013	1557	}
donatien	0:632c9925f013	1558	if (flags & TCP_SYN) {
donatien	0:632c9925f013	1559	LWIP_DEBUGF(TCP_DEBUG, ("SYN "));
donatien	0:632c9925f013	1560	}
donatien	0:632c9925f013	1561	if (flags & TCP_RST) {
donatien	0:632c9925f013	1562	LWIP_DEBUGF(TCP_DEBUG, ("RST "));
donatien	0:632c9925f013	1563	}
donatien	0:632c9925f013	1564	if (flags & TCP_PSH) {
donatien	0:632c9925f013	1565	LWIP_DEBUGF(TCP_DEBUG, ("PSH "));
donatien	0:632c9925f013	1566	}
donatien	0:632c9925f013	1567	if (flags & TCP_ACK) {
donatien	0:632c9925f013	1568	LWIP_DEBUGF(TCP_DEBUG, ("ACK "));
donatien	0:632c9925f013	1569	}
donatien	0:632c9925f013	1570	if (flags & TCP_URG) {
donatien	0:632c9925f013	1571	LWIP_DEBUGF(TCP_DEBUG, ("URG "));
donatien	0:632c9925f013	1572	}
donatien	0:632c9925f013	1573	if (flags & TCP_ECE) {
donatien	0:632c9925f013	1574	LWIP_DEBUGF(TCP_DEBUG, ("ECE "));
donatien	0:632c9925f013	1575	}
donatien	0:632c9925f013	1576	if (flags & TCP_CWR) {
donatien	0:632c9925f013	1577	LWIP_DEBUGF(TCP_DEBUG, ("CWR "));
donatien	0:632c9925f013	1578	}
donatien	0:632c9925f013	1579	LWIP_DEBUGF(TCP_DEBUG, ("\n"));
donatien	0:632c9925f013	1580	}
donatien	0:632c9925f013	1581
donatien	0:632c9925f013	1582	/**
donatien	0:632c9925f013	1583	* Print all tcp_pcbs in every list for debugging purposes.
donatien	0:632c9925f013	1584	*/
donatien	0:632c9925f013	1585	void
donatien	0:632c9925f013	1586	tcp_debug_print_pcbs(void)
donatien	0:632c9925f013	1587	{
donatien	0:632c9925f013	1588	struct tcp_pcb *pcb;
donatien	0:632c9925f013	1589	LWIP_DEBUGF(TCP_DEBUG, ("Active PCB states:\n"));
donatien	0:632c9925f013	1590	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1591	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
donatien	0:632c9925f013	1592	pcb->local_port, pcb->remote_port,
donatien	0:632c9925f013	1593	pcb->snd_nxt, pcb->rcv_nxt));
donatien	0:632c9925f013	1594	tcp_debug_print_state(pcb->state);
donatien	0:632c9925f013	1595	}
donatien	0:632c9925f013	1596	LWIP_DEBUGF(TCP_DEBUG, ("Listen PCB states:\n"));
donatien	0:632c9925f013	1597	for(pcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1598	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
donatien	0:632c9925f013	1599	pcb->local_port, pcb->remote_port,
donatien	0:632c9925f013	1600	pcb->snd_nxt, pcb->rcv_nxt));
donatien	0:632c9925f013	1601	tcp_debug_print_state(pcb->state);
donatien	0:632c9925f013	1602	}
donatien	0:632c9925f013	1603	LWIP_DEBUGF(TCP_DEBUG, ("TIME-WAIT PCB states:\n"));
donatien	0:632c9925f013	1604	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1605	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
donatien	0:632c9925f013	1606	pcb->local_port, pcb->remote_port,
donatien	0:632c9925f013	1607	pcb->snd_nxt, pcb->rcv_nxt));
donatien	0:632c9925f013	1608	tcp_debug_print_state(pcb->state);
donatien	0:632c9925f013	1609	}
donatien	0:632c9925f013	1610	}
donatien	0:632c9925f013	1611
donatien	0:632c9925f013	1612	/**
donatien	0:632c9925f013	1613	* Check state consistency of the tcp_pcb lists.
donatien	0:632c9925f013	1614	*/
donatien	0:632c9925f013	1615	s16_t
donatien	0:632c9925f013	1616	tcp_pcbs_sane(void)
donatien	0:632c9925f013	1617	{
donatien	0:632c9925f013	1618	struct tcp_pcb *pcb;
donatien	0:632c9925f013	1619	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1620	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != CLOSED", pcb->state != CLOSED);
donatien	0:632c9925f013	1621	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != LISTEN", pcb->state != LISTEN);
donatien	0:632c9925f013	1622	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT);
donatien	0:632c9925f013	1623	}
donatien	0:632c9925f013	1624	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1625	LWIP_ASSERT("tcp_pcbs_sane: tw pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
donatien	0:632c9925f013	1626	}
donatien	0:632c9925f013	1627	return 1;
donatien	0:632c9925f013	1628	}
donatien	0:632c9925f013	1629	#endif /* TCP_DEBUG */
donatien	0:632c9925f013	1630
donatien	0:632c9925f013	1631	#endif /* LWIP_TCP */

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Type:	Program
Created:	11 Jun 2010
Imports:	2654
Forks:	0
Commits:	12
Dependents:	3
Dependencies:	0
Followers:	13

This repository is Public (Unlisted).

lwip/core/tcp.c@11:da4498f591ee, 2010-08-05 (annotated)

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