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lwip/core/tcp.c@0:632c9925f013, 2010-06-11 (annotated)

Committer:: donatien
Date:: Fri Jun 11 16:05:15 2010 +0000
Revision:: 0:632c9925f013
Child:: 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	0:632c9925f013	58	const char *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	0:632c9925f013	91	/** Only used for temporary storage. */
donatien	0:632c9925f013	92	struct tcp_pcb *tcp_tmp_pcb;
donatien	0:632c9925f013	93
donatien	0:632c9925f013	94	/** Timer counter to handle calling slow-timer from tcp_tmr() */
donatien	0:632c9925f013	95	static u8_t tcp_timer;
donatien	0:632c9925f013	96	static u16_t tcp_new_port(void);
donatien	0:632c9925f013	97
donatien	0:632c9925f013	98	/**
donatien	0:632c9925f013	99	* Called periodically to dispatch TCP timers.
donatien	0:632c9925f013	100	*
donatien	0:632c9925f013	101	*/
donatien	0:632c9925f013	102	void
donatien	0:632c9925f013	103	tcp_tmr(void)
donatien	0:632c9925f013	104	{
donatien	0:632c9925f013	105	/* Call tcp_fasttmr() every 250 ms */
donatien	0:632c9925f013	106	tcp_fasttmr();
donatien	0:632c9925f013	107
donatien	0:632c9925f013	108	if (++tcp_timer & 1) {
donatien	0:632c9925f013	109	/* Call tcp_tmr() every 500 ms, i.e., every other timer
donatien	0:632c9925f013	110	tcp_tmr() is called. */
donatien	0:632c9925f013	111	tcp_slowtmr();
donatien	0:632c9925f013	112	}
donatien	0:632c9925f013	113	}
donatien	0:632c9925f013	114
donatien	0:632c9925f013	115	/**
donatien	0:632c9925f013	116	* Closes the TX side of a connection held by the PCB.
donatien	0:632c9925f013	117	* For tcp_close(), a RST is sent if the application didn't receive all data
donatien	0:632c9925f013	118	* (tcp_recved() not called for all data passed to recv callback).
donatien	0:632c9925f013	119	*
donatien	0:632c9925f013	120	* Listening pcbs are freed and may not be referenced any more.
donatien	0:632c9925f013	121	* Connection pcbs are freed if not yet connected and may not be referenced
donatien	0:632c9925f013	122	* any more. If a connection is established (at least SYN received or in
donatien	0:632c9925f013	123	* a closing state), the connection is closed, and put in a closing state.
donatien	0:632c9925f013	124	* The pcb is then automatically freed in tcp_slowtmr(). It is therefore
donatien	0:632c9925f013	125	* unsafe to reference it.
donatien	0:632c9925f013	126	*
donatien	0:632c9925f013	127	* @param pcb the tcp_pcb to close
donatien	0:632c9925f013	128	* @return ERR_OK if connection has been closed
donatien	0:632c9925f013	129	* another err_t if closing failed and pcb is not freed
donatien	0:632c9925f013	130	*/
donatien	0:632c9925f013	131	static err_t
donatien	0:632c9925f013	132	tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
donatien	0:632c9925f013	133	{
donatien	0:632c9925f013	134	err_t err;
donatien	0:632c9925f013	135
donatien	0:632c9925f013	136	if (rst_on_unacked_data && (pcb->state != LISTEN)) {
donatien	0:632c9925f013	137	if ((pcb->refused_data != NULL) \|\| (pcb->rcv_wnd != TCP_WND)) {
donatien	0:632c9925f013	138	/* Not all data received by application, send RST to tell the remote
donatien	0:632c9925f013	139	side about this. */
donatien	0:632c9925f013	140	tcp_rst(pcb->snd_nxt, pcb->rcv_nxt, &pcb->local_ip, &pcb->remote_ip,
donatien	0:632c9925f013	141	pcb->local_port, pcb->remote_port);
donatien	0:632c9925f013	142	}
donatien	0:632c9925f013	143	}
donatien	0:632c9925f013	144
donatien	0:632c9925f013	145	switch (pcb->state) {
donatien	0:632c9925f013	146	case CLOSED:
donatien	0:632c9925f013	147	/* Closing a pcb in the CLOSED state might seem erroneous,
donatien	0:632c9925f013	148	* however, it is in this state once allocated and as yet unused
donatien	0:632c9925f013	149	* and the user needs some way to free it should the need arise.
donatien	0:632c9925f013	150	* Calling tcp_close() with a pcb that has already been closed, (i.e. twice)
donatien	0:632c9925f013	151	* or for a pcb that has been used and then entered the CLOSED state
donatien	0:632c9925f013	152	* is erroneous, but this should never happen as the pcb has in those cases
donatien	0:632c9925f013	153	* been freed, and so any remaining handles are bogus. */
donatien	0:632c9925f013	154	err = ERR_OK;
donatien	0:632c9925f013	155	TCP_RMV(&tcp_bound_pcbs, pcb);
donatien	0:632c9925f013	156	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	157	pcb = NULL;
donatien	0:632c9925f013	158	break;
donatien	0:632c9925f013	159	case LISTEN:
donatien	0:632c9925f013	160	err = ERR_OK;
donatien	0:632c9925f013	161	tcp_pcb_remove((struct tcp_pcb **)&tcp_listen_pcbs.pcbs, pcb);
donatien	0:632c9925f013	162	memp_free(MEMP_TCP_PCB_LISTEN, pcb);
donatien	0:632c9925f013	163	pcb = NULL;
donatien	0:632c9925f013	164	break;
donatien	0:632c9925f013	165	case SYN_SENT:
donatien	0:632c9925f013	166	err = ERR_OK;
donatien	0:632c9925f013	167	tcp_pcb_remove(&tcp_active_pcbs, pcb);
donatien	0:632c9925f013	168	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	169	pcb = NULL;
donatien	0:632c9925f013	170	snmp_inc_tcpattemptfails();
donatien	0:632c9925f013	171	break;
donatien	0:632c9925f013	172	case SYN_RCVD:
donatien	0:632c9925f013	173	err = tcp_send_fin(pcb);
donatien	0:632c9925f013	174	if (err == ERR_OK) {
donatien	0:632c9925f013	175	snmp_inc_tcpattemptfails();
donatien	0:632c9925f013	176	pcb->state = FIN_WAIT_1;
donatien	0:632c9925f013	177	}
donatien	0:632c9925f013	178	break;
donatien	0:632c9925f013	179	case ESTABLISHED:
donatien	0:632c9925f013	180	err = tcp_send_fin(pcb);
donatien	0:632c9925f013	181	if (err == ERR_OK) {
donatien	0:632c9925f013	182	snmp_inc_tcpestabresets();
donatien	0:632c9925f013	183	pcb->state = FIN_WAIT_1;
donatien	0:632c9925f013	184	}
donatien	0:632c9925f013	185	break;
donatien	0:632c9925f013	186	case CLOSE_WAIT:
donatien	0:632c9925f013	187	err = tcp_send_fin(pcb);
donatien	0:632c9925f013	188	if (err == ERR_OK) {
donatien	0:632c9925f013	189	snmp_inc_tcpestabresets();
donatien	0:632c9925f013	190	pcb->state = LAST_ACK;
donatien	0:632c9925f013	191	}
donatien	0:632c9925f013	192	break;
donatien	0:632c9925f013	193	default:
donatien	0:632c9925f013	194	/* Has already been closed, do nothing. */
donatien	0:632c9925f013	195	err = ERR_OK;
donatien	0:632c9925f013	196	pcb = NULL;
donatien	0:632c9925f013	197	break;
donatien	0:632c9925f013	198	}
donatien	0:632c9925f013	199
donatien	0:632c9925f013	200	if (pcb != NULL && err == ERR_OK) {
donatien	0:632c9925f013	201	/* To ensure all data has been sent when tcp_close returns, we have
donatien	0:632c9925f013	202	to make sure tcp_output doesn't fail.
donatien	0:632c9925f013	203	Since we don't really have to ensure all data has been sent when tcp_close
donatien	0:632c9925f013	204	returns (unsent data is sent from tcp timer functions, also), we don't care
donatien	0:632c9925f013	205	for the return value of tcp_output for now. */
donatien	0:632c9925f013	206	/* @todo: When implementing SO_LINGER, this must be changed somehow:
donatien	0:632c9925f013	207	If SOF_LINGER is set, the data should be sent and acked before close returns.
donatien	0:632c9925f013	208	This can only be valid for sequential APIs, not for the raw API. */
donatien	0:632c9925f013	209	tcp_output(pcb);
donatien	0:632c9925f013	210	}
donatien	0:632c9925f013	211	return err;
donatien	0:632c9925f013	212	}
donatien	0:632c9925f013	213
donatien	0:632c9925f013	214	/**
donatien	0:632c9925f013	215	* Closes the connection held by the PCB.
donatien	0:632c9925f013	216	*
donatien	0:632c9925f013	217	* Listening pcbs are freed and may not be referenced any more.
donatien	0:632c9925f013	218	* Connection pcbs are freed if not yet connected and may not be referenced
donatien	0:632c9925f013	219	* any more. If a connection is established (at least SYN received or in
donatien	0:632c9925f013	220	* a closing state), the connection is closed, and put in a closing state.
donatien	0:632c9925f013	221	* The pcb is then automatically freed in tcp_slowtmr(). It is therefore
donatien	0:632c9925f013	222	* unsafe to reference it (unless an error is returned).
donatien	0:632c9925f013	223	*
donatien	0:632c9925f013	224	* @param pcb the tcp_pcb to close
donatien	0:632c9925f013	225	* @return ERR_OK if connection has been closed
donatien	0:632c9925f013	226	* another err_t if closing failed and pcb is not freed
donatien	0:632c9925f013	227	*/
donatien	0:632c9925f013	228	err_t
donatien	0:632c9925f013	229	tcp_close(struct tcp_pcb *pcb)
donatien	0:632c9925f013	230	{
donatien	0:632c9925f013	231	#if TCP_DEBUG
donatien	0:632c9925f013	232	LWIP_DEBUGF(TCP_DEBUG, ("tcp_close: closing in "));
donatien	0:632c9925f013	233	tcp_debug_print_state(pcb->state);
donatien	0:632c9925f013	234	#endif /* TCP_DEBUG */
donatien	0:632c9925f013	235
donatien	0:632c9925f013	236	if (pcb->state != LISTEN) {
donatien	0:632c9925f013	237	/* Set a flag not to receive any more data... */
donatien	0:632c9925f013	238	pcb->flags \|= TF_RXCLOSED;
donatien	0:632c9925f013	239	}
donatien	0:632c9925f013	240	/* ... and close */
donatien	0:632c9925f013	241	return tcp_close_shutdown(pcb, 1);
donatien	0:632c9925f013	242	}
donatien	0:632c9925f013	243
donatien	0:632c9925f013	244	/**
donatien	0:632c9925f013	245	* Causes all or part of a full-duplex connection of this PCB to be shut down.
donatien	0:632c9925f013	246	* This doesn't deallocate the PCB!
donatien	0:632c9925f013	247	*
donatien	0:632c9925f013	248	* @param pcb PCB to shutdown
donatien	0:632c9925f013	249	* @param shut_rx shut down receive side if this is != 0
donatien	0:632c9925f013	250	* @param shut_tx shut down send side if this is != 0
donatien	0:632c9925f013	251	* @return ERR_OK if shutdown succeeded (or the PCB has already been shut down)
donatien	0:632c9925f013	252	* another err_t on error.
donatien	0:632c9925f013	253	*/
donatien	0:632c9925f013	254	err_t
donatien	0:632c9925f013	255	tcp_shutdown(struct tcp_pcb *pcb, int shut_rx, int shut_tx)
donatien	0:632c9925f013	256	{
donatien	0:632c9925f013	257	if (pcb->state == LISTEN) {
donatien	0:632c9925f013	258	return ERR_CONN;
donatien	0:632c9925f013	259	}
donatien	0:632c9925f013	260	if (shut_rx) {
donatien	0:632c9925f013	261	/* shut down the receive side: free buffered data... */
donatien	0:632c9925f013	262	if (pcb->refused_data != NULL) {
donatien	0:632c9925f013	263	pbuf_free(pcb->refused_data);
donatien	0:632c9925f013	264	pcb->refused_data = NULL;
donatien	0:632c9925f013	265	}
donatien	0:632c9925f013	266	/* ... and set a flag not to receive any more data */
donatien	0:632c9925f013	267	pcb->flags \|= TF_RXCLOSED;
donatien	0:632c9925f013	268	}
donatien	0:632c9925f013	269	if (shut_tx) {
donatien	0:632c9925f013	270	/* This can't happen twice since if it succeeds, the pcb's state is changed.
donatien	0:632c9925f013	271	Only close in these states as the others directly deallocate the PCB */
donatien	0:632c9925f013	272	switch (pcb->state) {
donatien	0:632c9925f013	273	case SYN_RCVD:
donatien	0:632c9925f013	274	case ESTABLISHED:
donatien	0:632c9925f013	275	case CLOSE_WAIT:
donatien	0:632c9925f013	276	return tcp_close_shutdown(pcb, 0);
donatien	0:632c9925f013	277	default:
donatien	0:632c9925f013	278	/* don't shut down other states */
donatien	0:632c9925f013	279	break;
donatien	0:632c9925f013	280	}
donatien	0:632c9925f013	281	}
donatien	0:632c9925f013	282	/* @todo: return another err_t if not in correct state or already shut? */
donatien	0:632c9925f013	283	return ERR_OK;
donatien	0:632c9925f013	284	}
donatien	0:632c9925f013	285
donatien	0:632c9925f013	286	/**
donatien	0:632c9925f013	287	* Abandons a connection and optionally sends a RST to the remote
donatien	0:632c9925f013	288	* host. Deletes the local protocol control block. This is done when
donatien	0:632c9925f013	289	* a connection is killed because of shortage of memory.
donatien	0:632c9925f013	290	*
donatien	0:632c9925f013	291	* @param pcb the tcp_pcb to abort
donatien	0:632c9925f013	292	* @param reset boolean to indicate whether a reset should be sent
donatien	0:632c9925f013	293	*/
donatien	0:632c9925f013	294	void
donatien	0:632c9925f013	295	tcp_abandon(struct tcp_pcb *pcb, int reset)
donatien	0:632c9925f013	296	{
donatien	0:632c9925f013	297	u32_t seqno, ackno;
donatien	0:632c9925f013	298	u16_t remote_port, local_port;
donatien	0:632c9925f013	299	ip_addr_t remote_ip, local_ip;
donatien	0:632c9925f013	300	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	301	tcp_err_fn errf;
donatien	0:632c9925f013	302	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	303	void *errf_arg;
donatien	0:632c9925f013	304
donatien	0:632c9925f013	305
donatien	0:632c9925f013	306	/* Figure out on which TCP PCB list we are, and remove us. If we
donatien	0:632c9925f013	307	are in an active state, call the receive function associated with
donatien	0:632c9925f013	308	the PCB with a NULL argument, and send an RST to the remote end. */
donatien	0:632c9925f013	309	if (pcb->state == TIME_WAIT) {
donatien	0:632c9925f013	310	tcp_pcb_remove(&tcp_tw_pcbs, pcb);
donatien	0:632c9925f013	311	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	312	} else {
donatien	0:632c9925f013	313	/* @todo: pcb->state, LISTEN not allowed */
donatien	0:632c9925f013	314	seqno = pcb->snd_nxt;
donatien	0:632c9925f013	315	ackno = pcb->rcv_nxt;
donatien	0:632c9925f013	316	ip_addr_copy(local_ip, pcb->local_ip);
donatien	0:632c9925f013	317	ip_addr_copy(remote_ip, pcb->remote_ip);
donatien	0:632c9925f013	318	local_port = pcb->local_port;
donatien	0:632c9925f013	319	remote_port = pcb->remote_port;
donatien	0:632c9925f013	320	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	321	errf = pcb->errf;
donatien	0:632c9925f013	322	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	323	errf_arg = pcb->callback_arg;
donatien	0:632c9925f013	324	tcp_pcb_remove(&tcp_active_pcbs, pcb);
donatien	0:632c9925f013	325	if (pcb->unacked != NULL) {
donatien	0:632c9925f013	326	tcp_segs_free(pcb->unacked);
donatien	0:632c9925f013	327	}
donatien	0:632c9925f013	328	if (pcb->unsent != NULL) {
donatien	0:632c9925f013	329	tcp_segs_free(pcb->unsent);
donatien	0:632c9925f013	330	}
donatien	0:632c9925f013	331	#if TCP_QUEUE_OOSEQ
donatien	0:632c9925f013	332	if (pcb->ooseq != NULL) {
donatien	0:632c9925f013	333	tcp_segs_free(pcb->ooseq);
donatien	0:632c9925f013	334	}
donatien	0:632c9925f013	335	#endif /* TCP_QUEUE_OOSEQ */
donatien	0:632c9925f013	336	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	337	TCP_EVENT_ERR(errf, errf_arg, ERR_ABRT);
donatien	0:632c9925f013	338	if (reset) {
donatien	0:632c9925f013	339	LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_abandon: sending RST\n"));
donatien	0:632c9925f013	340	tcp_rst(seqno, ackno, &local_ip, &remote_ip, local_port, remote_port);
donatien	0:632c9925f013	341	}
donatien	0:632c9925f013	342	}
donatien	0:632c9925f013	343	}
donatien	0:632c9925f013	344
donatien	0:632c9925f013	345	/**
donatien	0:632c9925f013	346	* Aborts the connection by sending a RST (reset) segment to the remote
donatien	0:632c9925f013	347	* host. The pcb is deallocated. This function never fails.
donatien	0:632c9925f013	348	*
donatien	0:632c9925f013	349	* ATTENTION: When calling this from one of the TCP callbacks, make
donatien	0:632c9925f013	350	* sure you always return ERR_ABRT (and never return ERR_ABRT otherwise
donatien	0:632c9925f013	351	* or you will risk accessing deallocated memory or memory leaks!
donatien	0:632c9925f013	352	*
donatien	0:632c9925f013	353	* @param pcb the tcp pcb to abort
donatien	0:632c9925f013	354	*/
donatien	0:632c9925f013	355	void
donatien	0:632c9925f013	356	tcp_abort(struct tcp_pcb *pcb)
donatien	0:632c9925f013	357	{
donatien	0:632c9925f013	358	tcp_abandon(pcb, 1);
donatien	0:632c9925f013	359	}
donatien	0:632c9925f013	360
donatien	0:632c9925f013	361	/**
donatien	0:632c9925f013	362	* Binds the connection to a local portnumber and IP address. If the
donatien	0:632c9925f013	363	* IP address is not given (i.e., ipaddr == NULL), the IP address of
donatien	0:632c9925f013	364	* the outgoing network interface is used instead.
donatien	0:632c9925f013	365	*
donatien	0:632c9925f013	366	* @param pcb the tcp_pcb to bind (no check is done whether this pcb is
donatien	0:632c9925f013	367	* already bound!)
donatien	0:632c9925f013	368	* @param ipaddr the local ip address to bind to (use IP_ADDR_ANY to bind
donatien	0:632c9925f013	369	* to any local address
donatien	0:632c9925f013	370	* @param port the local port to bind to
donatien	0:632c9925f013	371	* @return ERR_USE if the port is already in use
donatien	0:632c9925f013	372	* ERR_OK if bound
donatien	0:632c9925f013	373	*/
donatien	0:632c9925f013	374	err_t
donatien	0:632c9925f013	375	tcp_bind(struct tcp_pcb pcb, ip_addr_t ipaddr, u16_t port)
donatien	0:632c9925f013	376	{
donatien	0:632c9925f013	377	struct tcp_pcb *cpcb;
donatien	0:632c9925f013	378
donatien	0:632c9925f013	379	LWIP_ERROR("tcp_bind: can only bind in state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
donatien	0:632c9925f013	380
donatien	0:632c9925f013	381	if (port == 0) {
donatien	0:632c9925f013	382	port = tcp_new_port();
donatien	0:632c9925f013	383	}
donatien	0:632c9925f013	384	/* Check if the address already is in use. */
donatien	0:632c9925f013	385	/* Check the listen pcbs. */
donatien	0:632c9925f013	386	for(cpcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs;
donatien	0:632c9925f013	387	cpcb != NULL; cpcb = cpcb->next) {
donatien	0:632c9925f013	388	if (cpcb->local_port == port) {
donatien	0:632c9925f013	389	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
donatien	0:632c9925f013	390	ip_addr_isany(ipaddr) \|\|
donatien	0:632c9925f013	391	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
donatien	0:632c9925f013	392	return ERR_USE;
donatien	0:632c9925f013	393	}
donatien	0:632c9925f013	394	}
donatien	0:632c9925f013	395	}
donatien	0:632c9925f013	396	/* Check the connected pcbs. */
donatien	0:632c9925f013	397	for(cpcb = tcp_active_pcbs;
donatien	0:632c9925f013	398	cpcb != NULL; cpcb = cpcb->next) {
donatien	0:632c9925f013	399	if (cpcb->local_port == port) {
donatien	0:632c9925f013	400	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
donatien	0:632c9925f013	401	ip_addr_isany(ipaddr) \|\|
donatien	0:632c9925f013	402	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
donatien	0:632c9925f013	403	return ERR_USE;
donatien	0:632c9925f013	404	}
donatien	0:632c9925f013	405	}
donatien	0:632c9925f013	406	}
donatien	0:632c9925f013	407	/* Check the bound, not yet connected pcbs. */
donatien	0:632c9925f013	408	for(cpcb = tcp_bound_pcbs; cpcb != NULL; cpcb = cpcb->next) {
donatien	0:632c9925f013	409	if (cpcb->local_port == port) {
donatien	0:632c9925f013	410	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
donatien	0:632c9925f013	411	ip_addr_isany(ipaddr) \|\|
donatien	0:632c9925f013	412	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
donatien	0:632c9925f013	413	return ERR_USE;
donatien	0:632c9925f013	414	}
donatien	0:632c9925f013	415	}
donatien	0:632c9925f013	416	}
donatien	0:632c9925f013	417	/* Unless the REUSEADDR flag is set,
donatien	0:632c9925f013	418	* we have to check the pcbs in TIME-WAIT state, also: */
donatien	0:632c9925f013	419	if ((pcb->so_options & SOF_REUSEADDR) == 0) {
donatien	0:632c9925f013	420	for(cpcb = tcp_tw_pcbs; cpcb != NULL; cpcb = cpcb->next) {
donatien	0:632c9925f013	421	if (cpcb->local_port == port) {
donatien	0:632c9925f013	422	if (ip_addr_isany(&(cpcb->local_ip)) \|\|
donatien	0:632c9925f013	423	ip_addr_isany(ipaddr) \|\|
donatien	0:632c9925f013	424	ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
donatien	0:632c9925f013	425	return ERR_USE;
donatien	0:632c9925f013	426	}
donatien	0:632c9925f013	427	}
donatien	0:632c9925f013	428	}
donatien	0:632c9925f013	429	}
donatien	0:632c9925f013	430
donatien	0:632c9925f013	431	if (!ip_addr_isany(ipaddr)) {
donatien	0:632c9925f013	432	pcb->local_ip = *ipaddr;
donatien	0:632c9925f013	433	}
donatien	0:632c9925f013	434	pcb->local_port = port;
donatien	0:632c9925f013	435	TCP_REG(&tcp_bound_pcbs, pcb);
donatien	0:632c9925f013	436	LWIP_DEBUGF(TCP_DEBUG, ("tcp_bind: bind to port %"U16_F"\n", port));
donatien	0:632c9925f013	437	return ERR_OK;
donatien	0:632c9925f013	438	}
donatien	0:632c9925f013	439	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	440	/**
donatien	0:632c9925f013	441	* Default accept callback if no accept callback is specified by the user.
donatien	0:632c9925f013	442	*/
donatien	0:632c9925f013	443	static err_t
donatien	0:632c9925f013	444	tcp_accept_null(void arg, struct tcp_pcb pcb, err_t err)
donatien	0:632c9925f013	445	{
donatien	0:632c9925f013	446	LWIP_UNUSED_ARG(arg);
donatien	0:632c9925f013	447	LWIP_UNUSED_ARG(pcb);
donatien	0:632c9925f013	448	LWIP_UNUSED_ARG(err);
donatien	0:632c9925f013	449
donatien	0:632c9925f013	450	return ERR_ABRT;
donatien	0:632c9925f013	451	}
donatien	0:632c9925f013	452	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	453
donatien	0:632c9925f013	454	/**
donatien	0:632c9925f013	455	* Set the state of the connection to be LISTEN, which means that it
donatien	0:632c9925f013	456	* is able to accept incoming connections. The protocol control block
donatien	0:632c9925f013	457	* is reallocated in order to consume less memory. Setting the
donatien	0:632c9925f013	458	* connection to LISTEN is an irreversible process.
donatien	0:632c9925f013	459	*
donatien	0:632c9925f013	460	* @param pcb the original tcp_pcb
donatien	0:632c9925f013	461	* @param backlog the incoming connections queue limit
donatien	0:632c9925f013	462	* @return tcp_pcb used for listening, consumes less memory.
donatien	0:632c9925f013	463	*
donatien	0:632c9925f013	464	* @note The original tcp_pcb is freed. This function therefore has to be
donatien	0:632c9925f013	465	* called like this:
donatien	0:632c9925f013	466	* tpcb = tcp_listen(tpcb);
donatien	0:632c9925f013	467	*/
donatien	0:632c9925f013	468	struct tcp_pcb *
donatien	0:632c9925f013	469	tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog)
donatien	0:632c9925f013	470	{
donatien	0:632c9925f013	471	struct tcp_pcb_listen *lpcb;
donatien	0:632c9925f013	472
donatien	0:632c9925f013	473	LWIP_UNUSED_ARG(backlog);
donatien	0:632c9925f013	474	LWIP_ERROR("tcp_listen: pcb already connected", pcb->state == CLOSED, return NULL);
donatien	0:632c9925f013	475
donatien	0:632c9925f013	476	/* already listening? */
donatien	0:632c9925f013	477	if (pcb->state == LISTEN) {
donatien	0:632c9925f013	478	return pcb;
donatien	0:632c9925f013	479	}
donatien	0:632c9925f013	480	lpcb = (struct tcp_pcb_listen *)memp_malloc(MEMP_TCP_PCB_LISTEN);
donatien	0:632c9925f013	481	if (lpcb == NULL) {
donatien	0:632c9925f013	482	return NULL;
donatien	0:632c9925f013	483	}
donatien	0:632c9925f013	484	lpcb->callback_arg = pcb->callback_arg;
donatien	0:632c9925f013	485	lpcb->local_port = pcb->local_port;
donatien	0:632c9925f013	486	lpcb->state = LISTEN;
donatien	0:632c9925f013	487	lpcb->so_options = pcb->so_options;
donatien	0:632c9925f013	488	lpcb->so_options \|= SOF_ACCEPTCONN;
donatien	0:632c9925f013	489	lpcb->ttl = pcb->ttl;
donatien	0:632c9925f013	490	lpcb->tos = pcb->tos;
donatien	0:632c9925f013	491	ip_addr_copy(lpcb->local_ip, pcb->local_ip);
donatien	0:632c9925f013	492	TCP_RMV(&tcp_bound_pcbs, pcb);
donatien	0:632c9925f013	493	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	494	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	495	lpcb->accept = tcp_accept_null;
donatien	0:632c9925f013	496	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	497	#if TCP_LISTEN_BACKLOG
donatien	0:632c9925f013	498	lpcb->accepts_pending = 0;
donatien	0:632c9925f013	499	lpcb->backlog = (backlog ? backlog : 1);
donatien	0:632c9925f013	500	#endif /* TCP_LISTEN_BACKLOG */
donatien	0:632c9925f013	501	TCP_REG(&tcp_listen_pcbs.listen_pcbs, lpcb);
donatien	0:632c9925f013	502	return (struct tcp_pcb *)lpcb;
donatien	0:632c9925f013	503	}
donatien	0:632c9925f013	504
donatien	0:632c9925f013	505	/**
donatien	0:632c9925f013	506	* Update the state that tracks the available window space to advertise.
donatien	0:632c9925f013	507	*
donatien	0:632c9925f013	508	* Returns how much extra window would be advertised if we sent an
donatien	0:632c9925f013	509	* update now.
donatien	0:632c9925f013	510	*/
donatien	0:632c9925f013	511	u32_t tcp_update_rcv_ann_wnd(struct tcp_pcb *pcb)
donatien	0:632c9925f013	512	{
donatien	0:632c9925f013	513	u32_t new_right_edge = pcb->rcv_nxt + pcb->rcv_wnd;
donatien	0:632c9925f013	514
donatien	0:632c9925f013	515	if (TCP_SEQ_GEQ(new_right_edge, pcb->rcv_ann_right_edge + LWIP_MIN((TCP_WND / 2), pcb->mss))) {
donatien	0:632c9925f013	516	/* we can advertise more window */
donatien	0:632c9925f013	517	pcb->rcv_ann_wnd = pcb->rcv_wnd;
donatien	0:632c9925f013	518	return new_right_edge - pcb->rcv_ann_right_edge;
donatien	0:632c9925f013	519	} else {
donatien	0:632c9925f013	520	if (TCP_SEQ_GT(pcb->rcv_nxt, pcb->rcv_ann_right_edge)) {
donatien	0:632c9925f013	521	/* Can happen due to other end sending out of advertised window,
donatien	0:632c9925f013	522	* but within actual available (but not yet advertised) window */
donatien	0:632c9925f013	523	pcb->rcv_ann_wnd = 0;
donatien	0:632c9925f013	524	} else {
donatien	0:632c9925f013	525	/* keep the right edge of window constant */
donatien	0:632c9925f013	526	u32_t new_rcv_ann_wnd = pcb->rcv_ann_right_edge - pcb->rcv_nxt;
donatien	0:632c9925f013	527	LWIP_ASSERT("new_rcv_ann_wnd <= 0xffff", new_rcv_ann_wnd <= 0xffff);
donatien	0:632c9925f013	528	pcb->rcv_ann_wnd = (u16_t)new_rcv_ann_wnd;
donatien	0:632c9925f013	529	}
donatien	0:632c9925f013	530	return 0;
donatien	0:632c9925f013	531	}
donatien	0:632c9925f013	532	}
donatien	0:632c9925f013	533
donatien	0:632c9925f013	534	/**
donatien	0:632c9925f013	535	* This function should be called by the application when it has
donatien	0:632c9925f013	536	* processed the data. The purpose is to advertise a larger window
donatien	0:632c9925f013	537	* when the data has been processed.
donatien	0:632c9925f013	538	*
donatien	0:632c9925f013	539	* @param pcb the tcp_pcb for which data is read
donatien	0:632c9925f013	540	* @param len the amount of bytes that have been read by the application
donatien	0:632c9925f013	541	*/
donatien	0:632c9925f013	542	void
donatien	0:632c9925f013	543	tcp_recved(struct tcp_pcb *pcb, u16_t len)
donatien	0:632c9925f013	544	{
donatien	0:632c9925f013	545	int wnd_inflation;
donatien	0:632c9925f013	546
donatien	0:632c9925f013	547	LWIP_ASSERT("tcp_recved: len would wrap rcv_wnd\n",
donatien	0:632c9925f013	548	len <= 0xffff - pcb->rcv_wnd );
donatien	0:632c9925f013	549
donatien	0:632c9925f013	550	pcb->rcv_wnd += len;
donatien	0:632c9925f013	551	if (pcb->rcv_wnd > TCP_WND) {
donatien	0:632c9925f013	552	pcb->rcv_wnd = TCP_WND;
donatien	0:632c9925f013	553	}
donatien	0:632c9925f013	554
donatien	0:632c9925f013	555	wnd_inflation = tcp_update_rcv_ann_wnd(pcb);
donatien	0:632c9925f013	556
donatien	0:632c9925f013	557	/* If the change in the right edge of window is significant (default
donatien	0:632c9925f013	558	* watermark is TCP_WND/4), then send an explicit update now.
donatien	0:632c9925f013	559	* Otherwise wait for a packet to be sent in the normal course of
donatien	0:632c9925f013	560	* events (or more window to be available later) */
donatien	0:632c9925f013	561	if (wnd_inflation >= TCP_WND_UPDATE_THRESHOLD) {
donatien	0:632c9925f013	562	tcp_ack_now(pcb);
donatien	0:632c9925f013	563	tcp_output(pcb);
donatien	0:632c9925f013	564	}
donatien	0:632c9925f013	565
donatien	0:632c9925f013	566	LWIP_DEBUGF(TCP_DEBUG, ("tcp_recved: recveived %"U16_F" bytes, wnd %"U16_F" (%"U16_F").\n",
donatien	0:632c9925f013	567	len, pcb->rcv_wnd, TCP_WND - pcb->rcv_wnd));
donatien	0:632c9925f013	568	}
donatien	0:632c9925f013	569
donatien	0:632c9925f013	570	/**
donatien	0:632c9925f013	571	* A nastly hack featuring 'goto' statements that allocates a
donatien	0:632c9925f013	572	* new TCP local port.
donatien	0:632c9925f013	573	*
donatien	0:632c9925f013	574	* @return a new (free) local TCP port number
donatien	0:632c9925f013	575	*/
donatien	0:632c9925f013	576	static u16_t
donatien	0:632c9925f013	577	tcp_new_port(void)
donatien	0:632c9925f013	578	{
donatien	0:632c9925f013	579	struct tcp_pcb *pcb;
donatien	0:632c9925f013	580	#ifndef TCP_LOCAL_PORT_RANGE_START
donatien	0:632c9925f013	581	#define TCP_LOCAL_PORT_RANGE_START 4096
donatien	0:632c9925f013	582	#define TCP_LOCAL_PORT_RANGE_END 0x7fff
donatien	0:632c9925f013	583	#endif
donatien	0:632c9925f013	584	static u16_t port = TCP_LOCAL_PORT_RANGE_START;
donatien	0:632c9925f013	585
donatien	0:632c9925f013	586	again:
donatien	0:632c9925f013	587	if (++port > TCP_LOCAL_PORT_RANGE_END) {
donatien	0:632c9925f013	588	port = TCP_LOCAL_PORT_RANGE_START;
donatien	0:632c9925f013	589	}
donatien	0:632c9925f013	590
donatien	0:632c9925f013	591	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	592	if (pcb->local_port == port) {
donatien	0:632c9925f013	593	goto again;
donatien	0:632c9925f013	594	}
donatien	0:632c9925f013	595	}
donatien	0:632c9925f013	596	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	597	if (pcb->local_port == port) {
donatien	0:632c9925f013	598	goto again;
donatien	0:632c9925f013	599	}
donatien	0:632c9925f013	600	}
donatien	0:632c9925f013	601	for(pcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	602	if (pcb->local_port == port) {
donatien	0:632c9925f013	603	goto again;
donatien	0:632c9925f013	604	}
donatien	0:632c9925f013	605	}
donatien	0:632c9925f013	606	return port;
donatien	0:632c9925f013	607	}
donatien	0:632c9925f013	608
donatien	0:632c9925f013	609	/**
donatien	0:632c9925f013	610	* Connects to another host. The function given as the "connected"
donatien	0:632c9925f013	611	* argument will be called when the connection has been established.
donatien	0:632c9925f013	612	*
donatien	0:632c9925f013	613	* @param pcb the tcp_pcb used to establish the connection
donatien	0:632c9925f013	614	* @param ipaddr the remote ip address to connect to
donatien	0:632c9925f013	615	* @param port the remote tcp port to connect to
donatien	0:632c9925f013	616	* @param connected callback function to call when connected (or on error)
donatien	0:632c9925f013	617	* @return ERR_VAL if invalid arguments are given
donatien	0:632c9925f013	618	* ERR_OK if connect request has been sent
donatien	0:632c9925f013	619	* other err_t values if connect request couldn't be sent
donatien	0:632c9925f013	620	*/
donatien	0:632c9925f013	621	err_t
donatien	0:632c9925f013	622	tcp_connect(struct tcp_pcb pcb, ip_addr_t ipaddr, u16_t port,
donatien	0:632c9925f013	623	tcp_connected_fn connected)
donatien	0:632c9925f013	624	{
donatien	0:632c9925f013	625	err_t ret;
donatien	0:632c9925f013	626	u32_t iss;
donatien	0:632c9925f013	627
donatien	0:632c9925f013	628	LWIP_ERROR("tcp_connect: can only connected from state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
donatien	0:632c9925f013	629
donatien	0:632c9925f013	630	LWIP_DEBUGF(TCP_DEBUG, ("tcp_connect to port %"U16_F"\n", port));
donatien	0:632c9925f013	631	if (ipaddr != NULL) {
donatien	0:632c9925f013	632	pcb->remote_ip = *ipaddr;
donatien	0:632c9925f013	633	} else {
donatien	0:632c9925f013	634	return ERR_VAL;
donatien	0:632c9925f013	635	}
donatien	0:632c9925f013	636	pcb->remote_port = port;
donatien	0:632c9925f013	637	if (pcb->local_port == 0) {
donatien	0:632c9925f013	638	pcb->local_port = tcp_new_port();
donatien	0:632c9925f013	639	}
donatien	0:632c9925f013	640	iss = tcp_next_iss();
donatien	0:632c9925f013	641	pcb->rcv_nxt = 0;
donatien	0:632c9925f013	642	pcb->snd_nxt = iss;
donatien	0:632c9925f013	643	pcb->lastack = iss - 1;
donatien	0:632c9925f013	644	pcb->snd_lbb = iss - 1;
donatien	0:632c9925f013	645	pcb->rcv_wnd = TCP_WND;
donatien	0:632c9925f013	646	pcb->rcv_ann_wnd = TCP_WND;
donatien	0:632c9925f013	647	pcb->rcv_ann_right_edge = pcb->rcv_nxt;
donatien	0:632c9925f013	648	pcb->snd_wnd = TCP_WND;
donatien	0:632c9925f013	649	/* As initial send MSS, we use TCP_MSS but limit it to 536.
donatien	0:632c9925f013	650	The send MSS is updated when an MSS option is received. */
donatien	0:632c9925f013	651	pcb->mss = (TCP_MSS > 536) ? 536 : TCP_MSS;
donatien	0:632c9925f013	652	#if TCP_CALCULATE_EFF_SEND_MSS
donatien	0:632c9925f013	653	pcb->mss = tcp_eff_send_mss(pcb->mss, ipaddr);
donatien	0:632c9925f013	654	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
donatien	0:632c9925f013	655	pcb->cwnd = 1;
donatien	0:632c9925f013	656	pcb->ssthresh = pcb->mss * 10;
donatien	0:632c9925f013	657	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	658	pcb->connected = connected;
donatien	0:632c9925f013	659	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	660
donatien	0:632c9925f013	661	/* Send a SYN together with the MSS option. */
donatien	0:632c9925f013	662	ret = tcp_enqueue_flags(pcb, TCP_SYN);
donatien	0:632c9925f013	663	if (ret == ERR_OK) {
donatien	0:632c9925f013	664	/* SYN segment was enqueued, changed the pcbs state now */
donatien	0:632c9925f013	665	pcb->state = SYN_SENT;
donatien	0:632c9925f013	666	TCP_RMV(&tcp_bound_pcbs, pcb);
donatien	0:632c9925f013	667	TCP_REG(&tcp_active_pcbs, pcb);
donatien	0:632c9925f013	668	snmp_inc_tcpactiveopens();
donatien	0:632c9925f013	669
donatien	0:632c9925f013	670	tcp_output(pcb);
donatien	0:632c9925f013	671	}
donatien	0:632c9925f013	672	return ret;
donatien	0:632c9925f013	673	}
donatien	0:632c9925f013	674
donatien	0:632c9925f013	675	/**
donatien	0:632c9925f013	676	* Called every 500 ms and implements the retransmission timer and the timer that
donatien	0:632c9925f013	677	* removes PCBs that have been in TIME-WAIT for enough time. It also increments
donatien	0:632c9925f013	678	* various timers such as the inactivity timer in each PCB.
donatien	0:632c9925f013	679	*
donatien	0:632c9925f013	680	* Automatically called from tcp_tmr().
donatien	0:632c9925f013	681	*/
donatien	0:632c9925f013	682	void
donatien	0:632c9925f013	683	tcp_slowtmr(void)
donatien	0:632c9925f013	684	{
donatien	0:632c9925f013	685	struct tcp_pcb pcb, pcb2, *prev;
donatien	0:632c9925f013	686	u16_t eff_wnd;
donatien	0:632c9925f013	687	u8_t pcb_remove; /* flag if a PCB should be removed */
donatien	0:632c9925f013	688	u8_t pcb_reset; /* flag if a RST should be sent when removing */
donatien	0:632c9925f013	689	err_t err;
donatien	0:632c9925f013	690
donatien	0:632c9925f013	691	err = ERR_OK;
donatien	0:632c9925f013	692
donatien	0:632c9925f013	693	++tcp_ticks;
donatien	0:632c9925f013	694
donatien	0:632c9925f013	695	/* Steps through all of the active PCBs. */
donatien	0:632c9925f013	696	prev = NULL;
donatien	0:632c9925f013	697	pcb = tcp_active_pcbs;
donatien	0:632c9925f013	698	if (pcb == NULL) {
donatien	0:632c9925f013	699	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: no active pcbs\n"));
donatien	0:632c9925f013	700	}
donatien	0:632c9925f013	701	while (pcb != NULL) {
donatien	0:632c9925f013	702	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: processing active pcb\n"));
donatien	0:632c9925f013	703	LWIP_ASSERT("tcp_slowtmr: active pcb->state != CLOSED\n", pcb->state != CLOSED);
donatien	0:632c9925f013	704	LWIP_ASSERT("tcp_slowtmr: active pcb->state != LISTEN\n", pcb->state != LISTEN);
donatien	0:632c9925f013	705	LWIP_ASSERT("tcp_slowtmr: active pcb->state != TIME-WAIT\n", pcb->state != TIME_WAIT);
donatien	0:632c9925f013	706
donatien	0:632c9925f013	707	pcb_remove = 0;
donatien	0:632c9925f013	708	pcb_reset = 0;
donatien	0:632c9925f013	709
donatien	0:632c9925f013	710	if (pcb->state == SYN_SENT && pcb->nrtx == TCP_SYNMAXRTX) {
donatien	0:632c9925f013	711	++pcb_remove;
donatien	0:632c9925f013	712	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max SYN retries reached\n"));
donatien	0:632c9925f013	713	}
donatien	0:632c9925f013	714	else if (pcb->nrtx == TCP_MAXRTX) {
donatien	0:632c9925f013	715	++pcb_remove;
donatien	0:632c9925f013	716	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max DATA retries reached\n"));
donatien	0:632c9925f013	717	} else {
donatien	0:632c9925f013	718	if (pcb->persist_backoff > 0) {
donatien	0:632c9925f013	719	/* If snd_wnd is zero, use persist timer to send 1 byte probes
donatien	0:632c9925f013	720	* instead of using the standard retransmission mechanism. */
donatien	0:632c9925f013	721	pcb->persist_cnt++;
donatien	0:632c9925f013	722	if (pcb->persist_cnt >= tcp_persist_backoff[pcb->persist_backoff-1]) {
donatien	0:632c9925f013	723	pcb->persist_cnt = 0;
donatien	0:632c9925f013	724	if (pcb->persist_backoff < sizeof(tcp_persist_backoff)) {
donatien	0:632c9925f013	725	pcb->persist_backoff++;
donatien	0:632c9925f013	726	}
donatien	0:632c9925f013	727	tcp_zero_window_probe(pcb);
donatien	0:632c9925f013	728	}
donatien	0:632c9925f013	729	} else {
donatien	0:632c9925f013	730	/* Increase the retransmission timer if it is running */
donatien	0:632c9925f013	731	if(pcb->rtime >= 0)
donatien	0:632c9925f013	732	++pcb->rtime;
donatien	0:632c9925f013	733
donatien	0:632c9925f013	734	if (pcb->unacked != NULL && pcb->rtime >= pcb->rto) {
donatien	0:632c9925f013	735	/* Time for a retransmission. */
donatien	0:632c9925f013	736	LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_slowtmr: rtime %"S16_F
donatien	0:632c9925f013	737	" pcb->rto %"S16_F"\n",
donatien	0:632c9925f013	738	pcb->rtime, pcb->rto));
donatien	0:632c9925f013	739
donatien	0:632c9925f013	740	/* Double retransmission time-out unless we are trying to
donatien	0:632c9925f013	741	* connect to somebody (i.e., we are in SYN_SENT). */
donatien	0:632c9925f013	742	if (pcb->state != SYN_SENT) {
donatien	0:632c9925f013	743	pcb->rto = ((pcb->sa >> 3) + pcb->sv) << tcp_backoff[pcb->nrtx];
donatien	0:632c9925f013	744	}
donatien	0:632c9925f013	745
donatien	0:632c9925f013	746	/* Reset the retransmission timer. */
donatien	0:632c9925f013	747	pcb->rtime = 0;
donatien	0:632c9925f013	748
donatien	0:632c9925f013	749	/* Reduce congestion window and ssthresh. */
donatien	0:632c9925f013	750	eff_wnd = LWIP_MIN(pcb->cwnd, pcb->snd_wnd);
donatien	0:632c9925f013	751	pcb->ssthresh = eff_wnd >> 1;
donatien	0:632c9925f013	752	if (pcb->ssthresh < (pcb->mss << 1)) {
donatien	0:632c9925f013	753	pcb->ssthresh = (pcb->mss << 1);
donatien	0:632c9925f013	754	}
donatien	0:632c9925f013	755	pcb->cwnd = pcb->mss;
donatien	0:632c9925f013	756	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: cwnd %"U16_F
donatien	0:632c9925f013	757	" ssthresh %"U16_F"\n",
donatien	0:632c9925f013	758	pcb->cwnd, pcb->ssthresh));
donatien	0:632c9925f013	759
donatien	0:632c9925f013	760	/* The following needs to be called AFTER cwnd is set to one
donatien	0:632c9925f013	761	mss - STJ */
donatien	0:632c9925f013	762	tcp_rexmit_rto(pcb);
donatien	0:632c9925f013	763	}
donatien	0:632c9925f013	764	}
donatien	0:632c9925f013	765	}
donatien	0:632c9925f013	766	/* Check if this PCB has stayed too long in FIN-WAIT-2 */
donatien	0:632c9925f013	767	if (pcb->state == FIN_WAIT_2) {
donatien	0:632c9925f013	768	if ((u32_t)(tcp_ticks - pcb->tmr) >
donatien	0:632c9925f013	769	TCP_FIN_WAIT_TIMEOUT / TCP_SLOW_INTERVAL) {
donatien	0:632c9925f013	770	++pcb_remove;
donatien	0:632c9925f013	771	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in FIN-WAIT-2\n"));
donatien	0:632c9925f013	772	}
donatien	0:632c9925f013	773	}
donatien	0:632c9925f013	774
donatien	0:632c9925f013	775	/* Check if KEEPALIVE should be sent */
donatien	0:632c9925f013	776	if((pcb->so_options & SOF_KEEPALIVE) &&
donatien	0:632c9925f013	777	((pcb->state == ESTABLISHED) \|\|
donatien	0:632c9925f013	778	(pcb->state == CLOSE_WAIT))) {
donatien	0:632c9925f013	779	#if LWIP_TCP_KEEPALIVE
donatien	0:632c9925f013	780	if((u32_t)(tcp_ticks - pcb->tmr) >
donatien	0:632c9925f013	781	(pcb->keep_idle + (pcb->keep_cnt*pcb->keep_intvl))
donatien	0:632c9925f013	782	/ TCP_SLOW_INTERVAL)
donatien	0:632c9925f013	783	#else
donatien	0:632c9925f013	784	if((u32_t)(tcp_ticks - pcb->tmr) >
donatien	0:632c9925f013	785	(pcb->keep_idle + TCP_MAXIDLE) / TCP_SLOW_INTERVAL)
donatien	0:632c9925f013	786	#endif /* LWIP_TCP_KEEPALIVE */
donatien	0:632c9925f013	787	{
donatien	0:632c9925f013	788	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: KEEPALIVE timeout. Aborting connection to %"U16_F".%"U16_F".%"U16_F".%"U16_F".\n",
donatien	0:632c9925f013	789	ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip),
donatien	0:632c9925f013	790	ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip)));
donatien	0:632c9925f013	791
donatien	0:632c9925f013	792	++pcb_remove;
donatien	0:632c9925f013	793	++pcb_reset;
donatien	0:632c9925f013	794	}
donatien	0:632c9925f013	795	#if LWIP_TCP_KEEPALIVE
donatien	0:632c9925f013	796	else if((u32_t)(tcp_ticks - pcb->tmr) >
donatien	0:632c9925f013	797	(pcb->keep_idle + pcb->keep_cnt_sent * pcb->keep_intvl)
donatien	0:632c9925f013	798	/ TCP_SLOW_INTERVAL)
donatien	0:632c9925f013	799	#else
donatien	0:632c9925f013	800	else if((u32_t)(tcp_ticks - pcb->tmr) >
donatien	0:632c9925f013	801	(pcb->keep_idle + pcb->keep_cnt_sent * TCP_KEEPINTVL_DEFAULT)
donatien	0:632c9925f013	802	/ TCP_SLOW_INTERVAL)
donatien	0:632c9925f013	803	#endif /* LWIP_TCP_KEEPALIVE */
donatien	0:632c9925f013	804	{
donatien	0:632c9925f013	805	tcp_keepalive(pcb);
donatien	0:632c9925f013	806	pcb->keep_cnt_sent++;
donatien	0:632c9925f013	807	}
donatien	0:632c9925f013	808	}
donatien	0:632c9925f013	809
donatien	0:632c9925f013	810	/* If this PCB has queued out of sequence data, but has been
donatien	0:632c9925f013	811	inactive for too long, will drop the data (it will eventually
donatien	0:632c9925f013	812	be retransmitted). */
donatien	0:632c9925f013	813	#if TCP_QUEUE_OOSEQ
donatien	0:632c9925f013	814	if (pcb->ooseq != NULL &&
donatien	0:632c9925f013	815	(u32_t)tcp_ticks - pcb->tmr >= pcb->rto * TCP_OOSEQ_TIMEOUT) {
donatien	0:632c9925f013	816	tcp_segs_free(pcb->ooseq);
donatien	0:632c9925f013	817	pcb->ooseq = NULL;
donatien	0:632c9925f013	818	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: dropping OOSEQ queued data\n"));
donatien	0:632c9925f013	819	}
donatien	0:632c9925f013	820	#endif /* TCP_QUEUE_OOSEQ */
donatien	0:632c9925f013	821
donatien	0:632c9925f013	822	/* Check if this PCB has stayed too long in SYN-RCVD */
donatien	0:632c9925f013	823	if (pcb->state == SYN_RCVD) {
donatien	0:632c9925f013	824	if ((u32_t)(tcp_ticks - pcb->tmr) >
donatien	0:632c9925f013	825	TCP_SYN_RCVD_TIMEOUT / TCP_SLOW_INTERVAL) {
donatien	0:632c9925f013	826	++pcb_remove;
donatien	0:632c9925f013	827	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in SYN-RCVD\n"));
donatien	0:632c9925f013	828	}
donatien	0:632c9925f013	829	}
donatien	0:632c9925f013	830
donatien	0:632c9925f013	831	/* Check if this PCB has stayed too long in LAST-ACK */
donatien	0:632c9925f013	832	if (pcb->state == LAST_ACK) {
donatien	0:632c9925f013	833	if ((u32_t)(tcp_ticks - pcb->tmr) > 2 * TCP_MSL / TCP_SLOW_INTERVAL) {
donatien	0:632c9925f013	834	++pcb_remove;
donatien	0:632c9925f013	835	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in LAST-ACK\n"));
donatien	0:632c9925f013	836	}
donatien	0:632c9925f013	837	}
donatien	0:632c9925f013	838
donatien	0:632c9925f013	839	/* If the PCB should be removed, do it. */
donatien	0:632c9925f013	840	if (pcb_remove) {
donatien	0:632c9925f013	841	tcp_pcb_purge(pcb);
donatien	0:632c9925f013	842	/* Remove PCB from tcp_active_pcbs list. */
donatien	0:632c9925f013	843	if (prev != NULL) {
donatien	0:632c9925f013	844	LWIP_ASSERT("tcp_slowtmr: middle tcp != tcp_active_pcbs", pcb != tcp_active_pcbs);
donatien	0:632c9925f013	845	prev->next = pcb->next;
donatien	0:632c9925f013	846	} else {
donatien	0:632c9925f013	847	/* This PCB was the first. */
donatien	0:632c9925f013	848	LWIP_ASSERT("tcp_slowtmr: first pcb == tcp_active_pcbs", tcp_active_pcbs == pcb);
donatien	0:632c9925f013	849	tcp_active_pcbs = pcb->next;
donatien	0:632c9925f013	850	}
donatien	0:632c9925f013	851
donatien	0:632c9925f013	852	TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_ABRT);
donatien	0:632c9925f013	853	if (pcb_reset) {
donatien	0:632c9925f013	854	tcp_rst(pcb->snd_nxt, pcb->rcv_nxt, &pcb->local_ip, &pcb->remote_ip,
donatien	0:632c9925f013	855	pcb->local_port, pcb->remote_port);
donatien	0:632c9925f013	856	}
donatien	0:632c9925f013	857
donatien	0:632c9925f013	858	pcb2 = pcb->next;
donatien	0:632c9925f013	859	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	860	pcb = pcb2;
donatien	0:632c9925f013	861	} else {
donatien	0:632c9925f013	862	/* get the 'next' element now and work with 'prev' below (in case of abort) */
donatien	0:632c9925f013	863	prev = pcb;
donatien	0:632c9925f013	864	pcb = pcb->next;
donatien	0:632c9925f013	865
donatien	0:632c9925f013	866	/* We check if we should poll the connection. */
donatien	0:632c9925f013	867	++prev->polltmr;
donatien	0:632c9925f013	868	if (prev->polltmr >= prev->pollinterval) {
donatien	0:632c9925f013	869	prev->polltmr = 0;
donatien	0:632c9925f013	870	LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: polling application\n"));
donatien	0:632c9925f013	871	TCP_EVENT_POLL(prev, err);
donatien	0:632c9925f013	872	/* if err == ERR_ABRT, 'prev' is already deallocated */
donatien	0:632c9925f013	873	if (err == ERR_OK) {
donatien	0:632c9925f013	874	tcp_output(prev);
donatien	0:632c9925f013	875	}
donatien	0:632c9925f013	876	}
donatien	0:632c9925f013	877	}
donatien	0:632c9925f013	878	}
donatien	0:632c9925f013	879
donatien	0:632c9925f013	880
donatien	0:632c9925f013	881	/* Steps through all of the TIME-WAIT PCBs. */
donatien	0:632c9925f013	882	prev = NULL;
donatien	0:632c9925f013	883	pcb = tcp_tw_pcbs;
donatien	0:632c9925f013	884	while (pcb != NULL) {
donatien	0:632c9925f013	885	LWIP_ASSERT("tcp_slowtmr: TIME-WAIT pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
donatien	0:632c9925f013	886	pcb_remove = 0;
donatien	0:632c9925f013	887
donatien	0:632c9925f013	888	/* Check if this PCB has stayed long enough in TIME-WAIT */
donatien	0:632c9925f013	889	if ((u32_t)(tcp_ticks - pcb->tmr) > 2 * TCP_MSL / TCP_SLOW_INTERVAL) {
donatien	0:632c9925f013	890	++pcb_remove;
donatien	0:632c9925f013	891	}
donatien	0:632c9925f013	892
donatien	0:632c9925f013	893
donatien	0:632c9925f013	894
donatien	0:632c9925f013	895	/* If the PCB should be removed, do it. */
donatien	0:632c9925f013	896	if (pcb_remove) {
donatien	0:632c9925f013	897	tcp_pcb_purge(pcb);
donatien	0:632c9925f013	898	/* Remove PCB from tcp_tw_pcbs list. */
donatien	0:632c9925f013	899	if (prev != NULL) {
donatien	0:632c9925f013	900	LWIP_ASSERT("tcp_slowtmr: middle tcp != tcp_tw_pcbs", pcb != tcp_tw_pcbs);
donatien	0:632c9925f013	901	prev->next = pcb->next;
donatien	0:632c9925f013	902	} else {
donatien	0:632c9925f013	903	/* This PCB was the first. */
donatien	0:632c9925f013	904	LWIP_ASSERT("tcp_slowtmr: first pcb == tcp_tw_pcbs", tcp_tw_pcbs == pcb);
donatien	0:632c9925f013	905	tcp_tw_pcbs = pcb->next;
donatien	0:632c9925f013	906	}
donatien	0:632c9925f013	907	pcb2 = pcb->next;
donatien	0:632c9925f013	908	memp_free(MEMP_TCP_PCB, pcb);
donatien	0:632c9925f013	909	pcb = pcb2;
donatien	0:632c9925f013	910	} else {
donatien	0:632c9925f013	911	prev = pcb;
donatien	0:632c9925f013	912	pcb = pcb->next;
donatien	0:632c9925f013	913	}
donatien	0:632c9925f013	914	}
donatien	0:632c9925f013	915	}
donatien	0:632c9925f013	916
donatien	0:632c9925f013	917	/**
donatien	0:632c9925f013	918	* Is called every TCP_FAST_INTERVAL (250 ms) and process data previously
donatien	0:632c9925f013	919	* "refused" by upper layer (application) and sends delayed ACKs.
donatien	0:632c9925f013	920	*
donatien	0:632c9925f013	921	* Automatically called from tcp_tmr().
donatien	0:632c9925f013	922	*/
donatien	0:632c9925f013	923	void
donatien	0:632c9925f013	924	tcp_fasttmr(void)
donatien	0:632c9925f013	925	{
donatien	0:632c9925f013	926	struct tcp_pcb *pcb = tcp_active_pcbs;
donatien	0:632c9925f013	927
donatien	0:632c9925f013	928	while(pcb != NULL) {
donatien	0:632c9925f013	929	struct tcp_pcb *next = pcb->next;
donatien	0:632c9925f013	930	/* If there is data which was previously "refused" by upper layer */
donatien	0:632c9925f013	931	if (pcb->refused_data != NULL) {
donatien	0:632c9925f013	932	/* Notify again application with data previously received. */
donatien	0:632c9925f013	933	err_t err;
donatien	0:632c9925f013	934	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_fasttmr: notify kept packet\n"));
donatien	0:632c9925f013	935	TCP_EVENT_RECV(pcb, pcb->refused_data, ERR_OK, err);
donatien	0:632c9925f013	936	if (err == ERR_OK) {
donatien	0:632c9925f013	937	pcb->refused_data = NULL;
donatien	0:632c9925f013	938	} else if (err == ERR_ABRT) {
donatien	0:632c9925f013	939	/* if err == ERR_ABRT, 'pcb' is already deallocated */
donatien	0:632c9925f013	940	pcb = NULL;
donatien	0:632c9925f013	941	}
donatien	0:632c9925f013	942	}
donatien	0:632c9925f013	943
donatien	0:632c9925f013	944	/* send delayed ACKs */
donatien	0:632c9925f013	945	if (pcb && (pcb->flags & TF_ACK_DELAY)) {
donatien	0:632c9925f013	946	LWIP_DEBUGF(TCP_DEBUG, ("tcp_fasttmr: delayed ACK\n"));
donatien	0:632c9925f013	947	tcp_ack_now(pcb);
donatien	0:632c9925f013	948	tcp_output(pcb);
donatien	0:632c9925f013	949	pcb->flags &= ~(TF_ACK_DELAY \| TF_ACK_NOW);
donatien	0:632c9925f013	950	}
donatien	0:632c9925f013	951
donatien	0:632c9925f013	952	pcb = next;
donatien	0:632c9925f013	953	}
donatien	0:632c9925f013	954	}
donatien	0:632c9925f013	955
donatien	0:632c9925f013	956	/**
donatien	0:632c9925f013	957	* Deallocates a list of TCP segments (tcp_seg structures).
donatien	0:632c9925f013	958	*
donatien	0:632c9925f013	959	* @param seg tcp_seg list of TCP segments to free
donatien	0:632c9925f013	960	*/
donatien	0:632c9925f013	961	void
donatien	0:632c9925f013	962	tcp_segs_free(struct tcp_seg *seg)
donatien	0:632c9925f013	963	{
donatien	0:632c9925f013	964	while (seg != NULL) {
donatien	0:632c9925f013	965	struct tcp_seg *next = seg->next;
donatien	0:632c9925f013	966	tcp_seg_free(seg);
donatien	0:632c9925f013	967	seg = next;
donatien	0:632c9925f013	968	}
donatien	0:632c9925f013	969	}
donatien	0:632c9925f013	970
donatien	0:632c9925f013	971	/**
donatien	0:632c9925f013	972	* Frees a TCP segment (tcp_seg structure).
donatien	0:632c9925f013	973	*
donatien	0:632c9925f013	974	* @param seg single tcp_seg to free
donatien	0:632c9925f013	975	*/
donatien	0:632c9925f013	976	void
donatien	0:632c9925f013	977	tcp_seg_free(struct tcp_seg *seg)
donatien	0:632c9925f013	978	{
donatien	0:632c9925f013	979	if (seg != NULL) {
donatien	0:632c9925f013	980	if (seg->p != NULL) {
donatien	0:632c9925f013	981	pbuf_free(seg->p);
donatien	0:632c9925f013	982	#if TCP_DEBUG
donatien	0:632c9925f013	983	seg->p = NULL;
donatien	0:632c9925f013	984	#endif /* TCP_DEBUG */
donatien	0:632c9925f013	985	}
donatien	0:632c9925f013	986	memp_free(MEMP_TCP_SEG, seg);
donatien	0:632c9925f013	987	}
donatien	0:632c9925f013	988	}
donatien	0:632c9925f013	989
donatien	0:632c9925f013	990	/**
donatien	0:632c9925f013	991	* Sets the priority of a connection.
donatien	0:632c9925f013	992	*
donatien	0:632c9925f013	993	* @param pcb the tcp_pcb to manipulate
donatien	0:632c9925f013	994	* @param prio new priority
donatien	0:632c9925f013	995	*/
donatien	0:632c9925f013	996	void
donatien	0:632c9925f013	997	tcp_setprio(struct tcp_pcb *pcb, u8_t prio)
donatien	0:632c9925f013	998	{
donatien	0:632c9925f013	999	pcb->prio = prio;
donatien	0:632c9925f013	1000	}
donatien	0:632c9925f013	1001	#if TCP_QUEUE_OOSEQ
donatien	0:632c9925f013	1002
donatien	0:632c9925f013	1003	/**
donatien	0:632c9925f013	1004	* Returns a copy of the given TCP segment.
donatien	0:632c9925f013	1005	* The pbuf and data are not copied, only the pointers
donatien	0:632c9925f013	1006	*
donatien	0:632c9925f013	1007	* @param seg the old tcp_seg
donatien	0:632c9925f013	1008	* @return a copy of seg
donatien	0:632c9925f013	1009	*/
donatien	0:632c9925f013	1010	struct tcp_seg *
donatien	0:632c9925f013	1011	tcp_seg_copy(struct tcp_seg *seg)
donatien	0:632c9925f013	1012	{
donatien	0:632c9925f013	1013	struct tcp_seg *cseg;
donatien	0:632c9925f013	1014
donatien	0:632c9925f013	1015	cseg = (struct tcp_seg *)memp_malloc(MEMP_TCP_SEG);
donatien	0:632c9925f013	1016	if (cseg == NULL) {
donatien	0:632c9925f013	1017	return NULL;
donatien	0:632c9925f013	1018	}
donatien	0:632c9925f013	1019	SMEMCPY((u8_t )cseg, (const u8_t )seg, sizeof(struct tcp_seg));
donatien	0:632c9925f013	1020	pbuf_ref(cseg->p);
donatien	0:632c9925f013	1021	return cseg;
donatien	0:632c9925f013	1022	}
donatien	0:632c9925f013	1023	#endif
donatien	0:632c9925f013	1024
donatien	0:632c9925f013	1025	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	1026	/**
donatien	0:632c9925f013	1027	* Default receive callback that is called if the user didn't register
donatien	0:632c9925f013	1028	* a recv callback for the pcb.
donatien	0:632c9925f013	1029	*/
donatien	0:632c9925f013	1030	err_t
donatien	0:632c9925f013	1031	tcp_recv_null(void arg, struct tcp_pcb pcb, struct pbuf *p, err_t err)
donatien	0:632c9925f013	1032	{
donatien	0:632c9925f013	1033	LWIP_UNUSED_ARG(arg);
donatien	0:632c9925f013	1034	if (p != NULL) {
donatien	0:632c9925f013	1035	tcp_recved(pcb, p->tot_len);
donatien	0:632c9925f013	1036	pbuf_free(p);
donatien	0:632c9925f013	1037	} else if (err == ERR_OK) {
donatien	0:632c9925f013	1038	return tcp_close(pcb);
donatien	0:632c9925f013	1039	}
donatien	0:632c9925f013	1040	return ERR_OK;
donatien	0:632c9925f013	1041	}
donatien	0:632c9925f013	1042	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	1043
donatien	0:632c9925f013	1044	/**
donatien	0:632c9925f013	1045	* Kills the oldest active connection that has lower priority than prio.
donatien	0:632c9925f013	1046	*
donatien	0:632c9925f013	1047	* @param prio minimum priority
donatien	0:632c9925f013	1048	*/
donatien	0:632c9925f013	1049	static void
donatien	0:632c9925f013	1050	tcp_kill_prio(u8_t prio)
donatien	0:632c9925f013	1051	{
donatien	0:632c9925f013	1052	struct tcp_pcb pcb, inactive;
donatien	0:632c9925f013	1053	u32_t inactivity;
donatien	0:632c9925f013	1054	u8_t mprio;
donatien	0:632c9925f013	1055
donatien	0:632c9925f013	1056
donatien	0:632c9925f013	1057	mprio = TCP_PRIO_MAX;
donatien	0:632c9925f013	1058
donatien	0:632c9925f013	1059	/* We kill the oldest active connection that has lower priority than prio. */
donatien	0:632c9925f013	1060	inactivity = 0;
donatien	0:632c9925f013	1061	inactive = NULL;
donatien	0:632c9925f013	1062	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1063	if (pcb->prio <= prio &&
donatien	0:632c9925f013	1064	pcb->prio <= mprio &&
donatien	0:632c9925f013	1065	(u32_t)(tcp_ticks - pcb->tmr) >= inactivity) {
donatien	0:632c9925f013	1066	inactivity = tcp_ticks - pcb->tmr;
donatien	0:632c9925f013	1067	inactive = pcb;
donatien	0:632c9925f013	1068	mprio = pcb->prio;
donatien	0:632c9925f013	1069	}
donatien	0:632c9925f013	1070	}
donatien	0:632c9925f013	1071	if (inactive != NULL) {
donatien	0:632c9925f013	1072	LWIP_DEBUGF(TCP_DEBUG, ("tcp_kill_prio: killing oldest PCB %p (%"S32_F")\n",
donatien	0:632c9925f013	1073	(void *)inactive, inactivity));
donatien	0:632c9925f013	1074	tcp_abort(inactive);
donatien	0:632c9925f013	1075	}
donatien	0:632c9925f013	1076	}
donatien	0:632c9925f013	1077
donatien	0:632c9925f013	1078	/**
donatien	0:632c9925f013	1079	* Kills the oldest connection that is in TIME_WAIT state.
donatien	0:632c9925f013	1080	* Called from tcp_alloc() if no more connections are available.
donatien	0:632c9925f013	1081	*/
donatien	0:632c9925f013	1082	static void
donatien	0:632c9925f013	1083	tcp_kill_timewait(void)
donatien	0:632c9925f013	1084	{
donatien	0:632c9925f013	1085	struct tcp_pcb pcb, inactive;
donatien	0:632c9925f013	1086	u32_t inactivity;
donatien	0:632c9925f013	1087
donatien	0:632c9925f013	1088	inactivity = 0;
donatien	0:632c9925f013	1089	inactive = NULL;
donatien	0:632c9925f013	1090	/* Go through the list of TIME_WAIT pcbs and get the oldest pcb. */
donatien	0:632c9925f013	1091	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1092	if ((u32_t)(tcp_ticks - pcb->tmr) >= inactivity) {
donatien	0:632c9925f013	1093	inactivity = tcp_ticks - pcb->tmr;
donatien	0:632c9925f013	1094	inactive = pcb;
donatien	0:632c9925f013	1095	}
donatien	0:632c9925f013	1096	}
donatien	0:632c9925f013	1097	if (inactive != NULL) {
donatien	0:632c9925f013	1098	LWIP_DEBUGF(TCP_DEBUG, ("tcp_kill_timewait: killing oldest TIME-WAIT PCB %p (%"S32_F")\n",
donatien	0:632c9925f013	1099	(void *)inactive, inactivity));
donatien	0:632c9925f013	1100	tcp_abort(inactive);
donatien	0:632c9925f013	1101	}
donatien	0:632c9925f013	1102	}
donatien	0:632c9925f013	1103
donatien	0:632c9925f013	1104	/**
donatien	0:632c9925f013	1105	* Allocate a new tcp_pcb structure.
donatien	0:632c9925f013	1106	*
donatien	0:632c9925f013	1107	* @param prio priority for the new pcb
donatien	0:632c9925f013	1108	* @return a new tcp_pcb that initially is in state CLOSED
donatien	0:632c9925f013	1109	*/
donatien	0:632c9925f013	1110	struct tcp_pcb *
donatien	0:632c9925f013	1111	tcp_alloc(u8_t prio)
donatien	0:632c9925f013	1112	{
donatien	0:632c9925f013	1113	struct tcp_pcb *pcb;
donatien	0:632c9925f013	1114	u32_t iss;
donatien	0:632c9925f013	1115
donatien	0:632c9925f013	1116	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
donatien	0:632c9925f013	1117	if (pcb == NULL) {
donatien	0:632c9925f013	1118	/* Try killing oldest connection in TIME-WAIT. */
donatien	0:632c9925f013	1119	LWIP_DEBUGF(TCP_DEBUG, ("tcp_alloc: killing off oldest TIME-WAIT connection\n"));
donatien	0:632c9925f013	1120	tcp_kill_timewait();
donatien	0:632c9925f013	1121	/* Try to allocate a tcp_pcb again. */
donatien	0:632c9925f013	1122	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
donatien	0:632c9925f013	1123	if (pcb == NULL) {
donatien	0:632c9925f013	1124	/* Try killing active connections with lower priority than the new one. */
donatien	0:632c9925f013	1125	LWIP_DEBUGF(TCP_DEBUG, ("tcp_alloc: killing connection with prio lower than %d\n", prio));
donatien	0:632c9925f013	1126	tcp_kill_prio(prio);
donatien	0:632c9925f013	1127	/* Try to allocate a tcp_pcb again. */
donatien	0:632c9925f013	1128	pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
donatien	0:632c9925f013	1129	if (pcb != NULL) {
donatien	0:632c9925f013	1130	/* adjust err stats: memp_malloc failed twice before */
donatien	0:632c9925f013	1131	MEMP_STATS_DEC(err, MEMP_TCP_PCB);
donatien	0:632c9925f013	1132	}
donatien	0:632c9925f013	1133	}
donatien	0:632c9925f013	1134	if (pcb != NULL) {
donatien	0:632c9925f013	1135	/* adjust err stats: timewait PCB was freed above */
donatien	0:632c9925f013	1136	MEMP_STATS_DEC(err, MEMP_TCP_PCB);
donatien	0:632c9925f013	1137	}
donatien	0:632c9925f013	1138	}
donatien	0:632c9925f013	1139	if (pcb != NULL) {
donatien	0:632c9925f013	1140	memset(pcb, 0, sizeof(struct tcp_pcb));
donatien	0:632c9925f013	1141	pcb->prio = prio;
donatien	0:632c9925f013	1142	pcb->snd_buf = TCP_SND_BUF;
donatien	0:632c9925f013	1143	pcb->snd_queuelen = 0;
donatien	0:632c9925f013	1144	pcb->rcv_wnd = TCP_WND;
donatien	0:632c9925f013	1145	pcb->rcv_ann_wnd = TCP_WND;
donatien	0:632c9925f013	1146	pcb->tos = 0;
donatien	0:632c9925f013	1147	pcb->ttl = TCP_TTL;
donatien	0:632c9925f013	1148	/* As initial send MSS, we use TCP_MSS but limit it to 536.
donatien	0:632c9925f013	1149	The send MSS is updated when an MSS option is received. */
donatien	0:632c9925f013	1150	pcb->mss = (TCP_MSS > 536) ? 536 : TCP_MSS;
donatien	0:632c9925f013	1151	pcb->rto = 3000 / TCP_SLOW_INTERVAL;
donatien	0:632c9925f013	1152	pcb->sa = 0;
donatien	0:632c9925f013	1153	pcb->sv = 3000 / TCP_SLOW_INTERVAL;
donatien	0:632c9925f013	1154	pcb->rtime = -1;
donatien	0:632c9925f013	1155	pcb->cwnd = 1;
donatien	0:632c9925f013	1156	iss = tcp_next_iss();
donatien	0:632c9925f013	1157	pcb->snd_wl2 = iss;
donatien	0:632c9925f013	1158	pcb->snd_nxt = iss;
donatien	0:632c9925f013	1159	pcb->lastack = iss;
donatien	0:632c9925f013	1160	pcb->snd_lbb = iss;
donatien	0:632c9925f013	1161	pcb->tmr = tcp_ticks;
donatien	0:632c9925f013	1162
donatien	0:632c9925f013	1163	pcb->polltmr = 0;
donatien	0:632c9925f013	1164
donatien	0:632c9925f013	1165	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	1166	pcb->recv = tcp_recv_null;
donatien	0:632c9925f013	1167	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	1168
donatien	0:632c9925f013	1169	/* Init KEEPALIVE timer */
donatien	0:632c9925f013	1170	pcb->keep_idle = TCP_KEEPIDLE_DEFAULT;
donatien	0:632c9925f013	1171
donatien	0:632c9925f013	1172	#if LWIP_TCP_KEEPALIVE
donatien	0:632c9925f013	1173	pcb->keep_intvl = TCP_KEEPINTVL_DEFAULT;
donatien	0:632c9925f013	1174	pcb->keep_cnt = TCP_KEEPCNT_DEFAULT;
donatien	0:632c9925f013	1175	#endif /* LWIP_TCP_KEEPALIVE */
donatien	0:632c9925f013	1176
donatien	0:632c9925f013	1177	pcb->keep_cnt_sent = 0;
donatien	0:632c9925f013	1178	}
donatien	0:632c9925f013	1179	return pcb;
donatien	0:632c9925f013	1180	}
donatien	0:632c9925f013	1181
donatien	0:632c9925f013	1182	/**
donatien	0:632c9925f013	1183	* Creates a new TCP protocol control block but doesn't place it on
donatien	0:632c9925f013	1184	* any of the TCP PCB lists.
donatien	0:632c9925f013	1185	* The pcb is not put on any list until binding using tcp_bind().
donatien	0:632c9925f013	1186	*
donatien	0:632c9925f013	1187	* @internal: Maybe there should be a idle TCP PCB list where these
donatien	0:632c9925f013	1188	* PCBs are put on. Port reservation using tcp_bind() is implemented but
donatien	0:632c9925f013	1189	* allocated pcbs that are not bound can't be killed automatically if wanting
donatien	0:632c9925f013	1190	* to allocate a pcb with higher prio (@see tcp_kill_prio())
donatien	0:632c9925f013	1191	*
donatien	0:632c9925f013	1192	* @return a new tcp_pcb that initially is in state CLOSED
donatien	0:632c9925f013	1193	*/
donatien	0:632c9925f013	1194	struct tcp_pcb *
donatien	0:632c9925f013	1195	tcp_new(void)
donatien	0:632c9925f013	1196	{
donatien	0:632c9925f013	1197	return tcp_alloc(TCP_PRIO_NORMAL);
donatien	0:632c9925f013	1198	}
donatien	0:632c9925f013	1199
donatien	0:632c9925f013	1200	/**
donatien	0:632c9925f013	1201	* Used to specify the argument that should be passed callback
donatien	0:632c9925f013	1202	* functions.
donatien	0:632c9925f013	1203	*
donatien	0:632c9925f013	1204	* @param pcb tcp_pcb to set the callback argument
donatien	0:632c9925f013	1205	* @param arg void pointer argument to pass to callback functions
donatien	0:632c9925f013	1206	*/
donatien	0:632c9925f013	1207	void
donatien	0:632c9925f013	1208	tcp_arg(struct tcp_pcb pcb, void arg)
donatien	0:632c9925f013	1209	{
donatien	0:632c9925f013	1210	pcb->callback_arg = arg;
donatien	0:632c9925f013	1211	}
donatien	0:632c9925f013	1212	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	1213
donatien	0:632c9925f013	1214	/**
donatien	0:632c9925f013	1215	* Used to specify the function that should be called when a TCP
donatien	0:632c9925f013	1216	* connection receives data.
donatien	0:632c9925f013	1217	*
donatien	0:632c9925f013	1218	* @param pcb tcp_pcb to set the recv callback
donatien	0:632c9925f013	1219	* @param recv callback function to call for this pcb when data is received
donatien	0:632c9925f013	1220	*/
donatien	0:632c9925f013	1221	void
donatien	0:632c9925f013	1222	tcp_recv(struct tcp_pcb *pcb, tcp_recv_fn recv)
donatien	0:632c9925f013	1223	{
donatien	0:632c9925f013	1224	pcb->recv = recv;
donatien	0:632c9925f013	1225	}
donatien	0:632c9925f013	1226
donatien	0:632c9925f013	1227	/**
donatien	0:632c9925f013	1228	* Used to specify the function that should be called when TCP data
donatien	0:632c9925f013	1229	* has been successfully delivered to the remote host.
donatien	0:632c9925f013	1230	*
donatien	0:632c9925f013	1231	* @param pcb tcp_pcb to set the sent callback
donatien	0:632c9925f013	1232	* @param sent callback function to call for this pcb when data is successfully sent
donatien	0:632c9925f013	1233	*/
donatien	0:632c9925f013	1234	void
donatien	0:632c9925f013	1235	tcp_sent(struct tcp_pcb *pcb, tcp_sent_fn sent)
donatien	0:632c9925f013	1236	{
donatien	0:632c9925f013	1237	pcb->sent = sent;
donatien	0:632c9925f013	1238	}
donatien	0:632c9925f013	1239
donatien	0:632c9925f013	1240	/**
donatien	0:632c9925f013	1241	* Used to specify the function that should be called when a fatal error
donatien	0:632c9925f013	1242	* has occured on the connection.
donatien	0:632c9925f013	1243	*
donatien	0:632c9925f013	1244	* @param pcb tcp_pcb to set the err callback
donatien	0:632c9925f013	1245	* @param err callback function to call for this pcb when a fatal error
donatien	0:632c9925f013	1246	* has occured on the connection
donatien	0:632c9925f013	1247	*/
donatien	0:632c9925f013	1248	void
donatien	0:632c9925f013	1249	tcp_err(struct tcp_pcb *pcb, tcp_err_fn err)
donatien	0:632c9925f013	1250	{
donatien	0:632c9925f013	1251	pcb->errf = err;
donatien	0:632c9925f013	1252	}
donatien	0:632c9925f013	1253
donatien	0:632c9925f013	1254	/**
donatien	0:632c9925f013	1255	* Used for specifying the function that should be called when a
donatien	0:632c9925f013	1256	* LISTENing connection has been connected to another host.
donatien	0:632c9925f013	1257	*
donatien	0:632c9925f013	1258	* @param pcb tcp_pcb to set the accept callback
donatien	0:632c9925f013	1259	* @param accept callback function to call for this pcb when LISTENing
donatien	0:632c9925f013	1260	* connection has been connected to another host
donatien	0:632c9925f013	1261	*/
donatien	0:632c9925f013	1262	void
donatien	0:632c9925f013	1263	tcp_accept(struct tcp_pcb *pcb, tcp_accept_fn accept)
donatien	0:632c9925f013	1264	{
donatien	0:632c9925f013	1265	pcb->accept = accept;
donatien	0:632c9925f013	1266	}
donatien	0:632c9925f013	1267	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	1268
donatien	0:632c9925f013	1269
donatien	0:632c9925f013	1270	/**
donatien	0:632c9925f013	1271	* Used to specify the function that should be called periodically
donatien	0:632c9925f013	1272	* from TCP. The interval is specified in terms of the TCP coarse
donatien	0:632c9925f013	1273	* timer interval, which is called twice a second.
donatien	0:632c9925f013	1274	*
donatien	0:632c9925f013	1275	*/
donatien	0:632c9925f013	1276	void
donatien	0:632c9925f013	1277	tcp_poll(struct tcp_pcb *pcb, tcp_poll_fn poll, u8_t interval)
donatien	0:632c9925f013	1278	{
donatien	0:632c9925f013	1279	#if LWIP_CALLBACK_API
donatien	0:632c9925f013	1280	pcb->poll = poll;
donatien	0:632c9925f013	1281	#endif /* LWIP_CALLBACK_API */
donatien	0:632c9925f013	1282	pcb->pollinterval = interval;
donatien	0:632c9925f013	1283	}
donatien	0:632c9925f013	1284
donatien	0:632c9925f013	1285	/**
donatien	0:632c9925f013	1286	* Purges a TCP PCB. Removes any buffered data and frees the buffer memory
donatien	0:632c9925f013	1287	* (pcb->ooseq, pcb->unsent and pcb->unacked are freed).
donatien	0:632c9925f013	1288	*
donatien	0:632c9925f013	1289	* @param pcb tcp_pcb to purge. The pcb itself is not deallocated!
donatien	0:632c9925f013	1290	*/
donatien	0:632c9925f013	1291	void
donatien	0:632c9925f013	1292	tcp_pcb_purge(struct tcp_pcb *pcb)
donatien	0:632c9925f013	1293	{
donatien	0:632c9925f013	1294	if (pcb->state != CLOSED &&
donatien	0:632c9925f013	1295	pcb->state != TIME_WAIT &&
donatien	0:632c9925f013	1296	pcb->state != LISTEN) {
donatien	0:632c9925f013	1297
donatien	0:632c9925f013	1298	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge\n"));
donatien	0:632c9925f013	1299
donatien	0:632c9925f013	1300	#if TCP_LISTEN_BACKLOG
donatien	0:632c9925f013	1301	if (pcb->state == SYN_RCVD) {
donatien	0:632c9925f013	1302	/* Need to find the corresponding listen_pcb and decrease its accepts_pending */
donatien	0:632c9925f013	1303	struct tcp_pcb_listen *lpcb;
donatien	0:632c9925f013	1304	LWIP_ASSERT("tcp_pcb_purge: pcb->state == SYN_RCVD but tcp_listen_pcbs is NULL",
donatien	0:632c9925f013	1305	tcp_listen_pcbs.listen_pcbs != NULL);
donatien	0:632c9925f013	1306	for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
donatien	0:632c9925f013	1307	if ((lpcb->local_port == pcb->local_port) &&
donatien	0:632c9925f013	1308	(ip_addr_isany(&lpcb->local_ip) \|\|
donatien	0:632c9925f013	1309	ip_addr_cmp(&pcb->local_ip, &lpcb->local_ip))) {
donatien	0:632c9925f013	1310	/* port and address of the listen pcb match the timed-out pcb */
donatien	0:632c9925f013	1311	LWIP_ASSERT("tcp_pcb_purge: listen pcb does not have accepts pending",
donatien	0:632c9925f013	1312	lpcb->accepts_pending > 0);
donatien	0:632c9925f013	1313	lpcb->accepts_pending--;
donatien	0:632c9925f013	1314	break;
donatien	0:632c9925f013	1315	}
donatien	0:632c9925f013	1316	}
donatien	0:632c9925f013	1317	}
donatien	0:632c9925f013	1318	#endif /* TCP_LISTEN_BACKLOG */
donatien	0:632c9925f013	1319
donatien	0:632c9925f013	1320
donatien	0:632c9925f013	1321	if (pcb->refused_data != NULL) {
donatien	0:632c9925f013	1322	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->refused_data\n"));
donatien	0:632c9925f013	1323	pbuf_free(pcb->refused_data);
donatien	0:632c9925f013	1324	pcb->refused_data = NULL;
donatien	0:632c9925f013	1325	}
donatien	0:632c9925f013	1326	if (pcb->unsent != NULL) {
donatien	0:632c9925f013	1327	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: not all data sent\n"));
donatien	0:632c9925f013	1328	}
donatien	0:632c9925f013	1329	if (pcb->unacked != NULL) {
donatien	0:632c9925f013	1330	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->unacked\n"));
donatien	0:632c9925f013	1331	}
donatien	0:632c9925f013	1332	#if TCP_QUEUE_OOSEQ /* LW */
donatien	0:632c9925f013	1333	if (pcb->ooseq != NULL) {
donatien	0:632c9925f013	1334	LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->ooseq\n"));
donatien	0:632c9925f013	1335	}
donatien	0:632c9925f013	1336	tcp_segs_free(pcb->ooseq);
donatien	0:632c9925f013	1337	pcb->ooseq = NULL;
donatien	0:632c9925f013	1338	#endif /* TCP_QUEUE_OOSEQ */
donatien	0:632c9925f013	1339
donatien	0:632c9925f013	1340	/* Stop the retransmission timer as it will expect data on unacked
donatien	0:632c9925f013	1341	queue if it fires */
donatien	0:632c9925f013	1342	pcb->rtime = -1;
donatien	0:632c9925f013	1343
donatien	0:632c9925f013	1344	tcp_segs_free(pcb->unsent);
donatien	0:632c9925f013	1345	tcp_segs_free(pcb->unacked);
donatien	0:632c9925f013	1346	pcb->unacked = pcb->unsent = NULL;
donatien	0:632c9925f013	1347	#if TCP_OVERSIZE
donatien	0:632c9925f013	1348	pcb->unsent_oversize = 0;
donatien	0:632c9925f013	1349	#endif /* TCP_OVERSIZE */
donatien	0:632c9925f013	1350	}
donatien	0:632c9925f013	1351	}
donatien	0:632c9925f013	1352
donatien	0:632c9925f013	1353	/**
donatien	0:632c9925f013	1354	* Purges the PCB and removes it from a PCB list. Any delayed ACKs are sent first.
donatien	0:632c9925f013	1355	*
donatien	0:632c9925f013	1356	* @param pcblist PCB list to purge.
donatien	0:632c9925f013	1357	* @param pcb tcp_pcb to purge. The pcb itself is NOT deallocated!
donatien	0:632c9925f013	1358	*/
donatien	0:632c9925f013	1359	void
donatien	0:632c9925f013	1360	tcp_pcb_remove(struct tcp_pcb *pcblist, struct tcp_pcb pcb)
donatien	0:632c9925f013	1361	{
donatien	0:632c9925f013	1362	TCP_RMV(pcblist, pcb);
donatien	0:632c9925f013	1363
donatien	0:632c9925f013	1364	tcp_pcb_purge(pcb);
donatien	0:632c9925f013	1365
donatien	0:632c9925f013	1366	/* if there is an outstanding delayed ACKs, send it */
donatien	0:632c9925f013	1367	if (pcb->state != TIME_WAIT &&
donatien	0:632c9925f013	1368	pcb->state != LISTEN &&
donatien	0:632c9925f013	1369	pcb->flags & TF_ACK_DELAY) {
donatien	0:632c9925f013	1370	pcb->flags \|= TF_ACK_NOW;
donatien	0:632c9925f013	1371	tcp_output(pcb);
donatien	0:632c9925f013	1372	}
donatien	0:632c9925f013	1373
donatien	0:632c9925f013	1374	if (pcb->state != LISTEN) {
donatien	0:632c9925f013	1375	LWIP_ASSERT("unsent segments leaking", pcb->unsent == NULL);
donatien	0:632c9925f013	1376	LWIP_ASSERT("unacked segments leaking", pcb->unacked == NULL);
donatien	0:632c9925f013	1377	#if TCP_QUEUE_OOSEQ
donatien	0:632c9925f013	1378	LWIP_ASSERT("ooseq segments leaking", pcb->ooseq == NULL);
donatien	0:632c9925f013	1379	#endif /* TCP_QUEUE_OOSEQ */
donatien	0:632c9925f013	1380	}
donatien	0:632c9925f013	1381
donatien	0:632c9925f013	1382	pcb->state = CLOSED;
donatien	0:632c9925f013	1383
donatien	0:632c9925f013	1384	LWIP_ASSERT("tcp_pcb_remove: tcp_pcbs_sane()", tcp_pcbs_sane());
donatien	0:632c9925f013	1385	}
donatien	0:632c9925f013	1386
donatien	0:632c9925f013	1387	/**
donatien	0:632c9925f013	1388	* Calculates a new initial sequence number for new connections.
donatien	0:632c9925f013	1389	*
donatien	0:632c9925f013	1390	* @return u32_t pseudo random sequence number
donatien	0:632c9925f013	1391	*/
donatien	0:632c9925f013	1392	u32_t
donatien	0:632c9925f013	1393	tcp_next_iss(void)
donatien	0:632c9925f013	1394	{
donatien	0:632c9925f013	1395	static u32_t iss = 6510;
donatien	0:632c9925f013	1396
donatien	0:632c9925f013	1397	iss += tcp_ticks; /* XXX */
donatien	0:632c9925f013	1398	return iss;
donatien	0:632c9925f013	1399	}
donatien	0:632c9925f013	1400
donatien	0:632c9925f013	1401	#if TCP_CALCULATE_EFF_SEND_MSS
donatien	0:632c9925f013	1402	/**
donatien	0:632c9925f013	1403	* Calcluates the effective send mss that can be used for a specific IP address
donatien	0:632c9925f013	1404	* by using ip_route to determin the netif used to send to the address and
donatien	0:632c9925f013	1405	* calculating the minimum of TCP_MSS and that netif's mtu (if set).
donatien	0:632c9925f013	1406	*/
donatien	0:632c9925f013	1407	u16_t
donatien	0:632c9925f013	1408	tcp_eff_send_mss(u16_t sendmss, ip_addr_t *addr)
donatien	0:632c9925f013	1409	{
donatien	0:632c9925f013	1410	u16_t mss_s;
donatien	0:632c9925f013	1411	struct netif *outif;
donatien	0:632c9925f013	1412
donatien	0:632c9925f013	1413	outif = ip_route(addr);
donatien	0:632c9925f013	1414	if ((outif != NULL) && (outif->mtu != 0)) {
donatien	0:632c9925f013	1415	mss_s = outif->mtu - IP_HLEN - TCP_HLEN;
donatien	0:632c9925f013	1416	/* RFC 1122, chap 4.2.2.6:
donatien	0:632c9925f013	1417	* Eff.snd.MSS = min(SendMSS+20, MMS_S) - TCPhdrsize - IPoptionsize
donatien	0:632c9925f013	1418	* We correct for TCP options in tcp_write(), and don't support IP options.
donatien	0:632c9925f013	1419	*/
donatien	0:632c9925f013	1420	sendmss = LWIP_MIN(sendmss, mss_s);
donatien	0:632c9925f013	1421	}
donatien	0:632c9925f013	1422	return sendmss;
donatien	0:632c9925f013	1423	}
donatien	0:632c9925f013	1424	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
donatien	0:632c9925f013	1425
donatien	0:632c9925f013	1426	const char*
donatien	0:632c9925f013	1427	tcp_debug_state_str(enum tcp_state s)
donatien	0:632c9925f013	1428	{
donatien	0:632c9925f013	1429	return tcp_state_str[s];
donatien	0:632c9925f013	1430	}
donatien	0:632c9925f013	1431
donatien	0:632c9925f013	1432	#if TCP_DEBUG \|\| TCP_INPUT_DEBUG \|\| TCP_OUTPUT_DEBUG
donatien	0:632c9925f013	1433	/**
donatien	0:632c9925f013	1434	* Print a tcp header for debugging purposes.
donatien	0:632c9925f013	1435	*
donatien	0:632c9925f013	1436	* @param tcphdr pointer to a struct tcp_hdr
donatien	0:632c9925f013	1437	*/
donatien	0:632c9925f013	1438	void
donatien	0:632c9925f013	1439	tcp_debug_print(struct tcp_hdr *tcphdr)
donatien	0:632c9925f013	1440	{
donatien	0:632c9925f013	1441	LWIP_DEBUGF(TCP_DEBUG, ("TCP header:\n"));
donatien	0:632c9925f013	1442	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
donatien	0:632c9925f013	1443	LWIP_DEBUGF(TCP_DEBUG, ("\| %5"U16_F" \| %5"U16_F" \| (src port, dest port)\n",
donatien	0:632c9925f013	1444	ntohs(tcphdr->src), ntohs(tcphdr->dest)));
donatien	0:632c9925f013	1445	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
donatien	0:632c9925f013	1446	LWIP_DEBUGF(TCP_DEBUG, ("\| %010"U32_F" \| (seq no)\n",
donatien	0:632c9925f013	1447	ntohl(tcphdr->seqno)));
donatien	0:632c9925f013	1448	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
donatien	0:632c9925f013	1449	LWIP_DEBUGF(TCP_DEBUG, ("\| %010"U32_F" \| (ack no)\n",
donatien	0:632c9925f013	1450	ntohl(tcphdr->ackno)));
donatien	0:632c9925f013	1451	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
donatien	0:632c9925f013	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 (",
donatien	0:632c9925f013	1453	TCPH_HDRLEN(tcphdr),
donatien	0:632c9925f013	1454	TCPH_FLAGS(tcphdr) >> 5 & 1,
donatien	0:632c9925f013	1455	TCPH_FLAGS(tcphdr) >> 4 & 1,
donatien	0:632c9925f013	1456	TCPH_FLAGS(tcphdr) >> 3 & 1,
donatien	0:632c9925f013	1457	TCPH_FLAGS(tcphdr) >> 2 & 1,
donatien	0:632c9925f013	1458	TCPH_FLAGS(tcphdr) >> 1 & 1,
donatien	0:632c9925f013	1459	TCPH_FLAGS(tcphdr) & 1,
donatien	0:632c9925f013	1460	ntohs(tcphdr->wnd)));
donatien	0:632c9925f013	1461	tcp_debug_print_flags(TCPH_FLAGS(tcphdr));
donatien	0:632c9925f013	1462	LWIP_DEBUGF(TCP_DEBUG, ("), win)\n"));
donatien	0:632c9925f013	1463	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
donatien	0:632c9925f013	1464	LWIP_DEBUGF(TCP_DEBUG, ("\| 0x%04"X16_F" \| %5"U16_F" \| (chksum, urgp)\n",
donatien	0:632c9925f013	1465	ntohs(tcphdr->chksum), ntohs(tcphdr->urgp)));
donatien	0:632c9925f013	1466	LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
donatien	0:632c9925f013	1467	}
donatien	0:632c9925f013	1468
donatien	0:632c9925f013	1469	/**
donatien	0:632c9925f013	1470	* Print a tcp state for debugging purposes.
donatien	0:632c9925f013	1471	*
donatien	0:632c9925f013	1472	* @param s enum tcp_state to print
donatien	0:632c9925f013	1473	*/
donatien	0:632c9925f013	1474	void
donatien	0:632c9925f013	1475	tcp_debug_print_state(enum tcp_state s)
donatien	0:632c9925f013	1476	{
donatien	0:632c9925f013	1477	LWIP_DEBUGF(TCP_DEBUG, ("State: %s\n", tcp_state_str[s]));
donatien	0:632c9925f013	1478	}
donatien	0:632c9925f013	1479
donatien	0:632c9925f013	1480	/**
donatien	0:632c9925f013	1481	* Print tcp flags for debugging purposes.
donatien	0:632c9925f013	1482	*
donatien	0:632c9925f013	1483	* @param flags tcp flags, all active flags are printed
donatien	0:632c9925f013	1484	*/
donatien	0:632c9925f013	1485	void
donatien	0:632c9925f013	1486	tcp_debug_print_flags(u8_t flags)
donatien	0:632c9925f013	1487	{
donatien	0:632c9925f013	1488	if (flags & TCP_FIN) {
donatien	0:632c9925f013	1489	LWIP_DEBUGF(TCP_DEBUG, ("FIN "));
donatien	0:632c9925f013	1490	}
donatien	0:632c9925f013	1491	if (flags & TCP_SYN) {
donatien	0:632c9925f013	1492	LWIP_DEBUGF(TCP_DEBUG, ("SYN "));
donatien	0:632c9925f013	1493	}
donatien	0:632c9925f013	1494	if (flags & TCP_RST) {
donatien	0:632c9925f013	1495	LWIP_DEBUGF(TCP_DEBUG, ("RST "));
donatien	0:632c9925f013	1496	}
donatien	0:632c9925f013	1497	if (flags & TCP_PSH) {
donatien	0:632c9925f013	1498	LWIP_DEBUGF(TCP_DEBUG, ("PSH "));
donatien	0:632c9925f013	1499	}
donatien	0:632c9925f013	1500	if (flags & TCP_ACK) {
donatien	0:632c9925f013	1501	LWIP_DEBUGF(TCP_DEBUG, ("ACK "));
donatien	0:632c9925f013	1502	}
donatien	0:632c9925f013	1503	if (flags & TCP_URG) {
donatien	0:632c9925f013	1504	LWIP_DEBUGF(TCP_DEBUG, ("URG "));
donatien	0:632c9925f013	1505	}
donatien	0:632c9925f013	1506	if (flags & TCP_ECE) {
donatien	0:632c9925f013	1507	LWIP_DEBUGF(TCP_DEBUG, ("ECE "));
donatien	0:632c9925f013	1508	}
donatien	0:632c9925f013	1509	if (flags & TCP_CWR) {
donatien	0:632c9925f013	1510	LWIP_DEBUGF(TCP_DEBUG, ("CWR "));
donatien	0:632c9925f013	1511	}
donatien	0:632c9925f013	1512	LWIP_DEBUGF(TCP_DEBUG, ("\n"));
donatien	0:632c9925f013	1513	}
donatien	0:632c9925f013	1514
donatien	0:632c9925f013	1515	/**
donatien	0:632c9925f013	1516	* Print all tcp_pcbs in every list for debugging purposes.
donatien	0:632c9925f013	1517	*/
donatien	0:632c9925f013	1518	void
donatien	0:632c9925f013	1519	tcp_debug_print_pcbs(void)
donatien	0:632c9925f013	1520	{
donatien	0:632c9925f013	1521	struct tcp_pcb *pcb;
donatien	0:632c9925f013	1522	LWIP_DEBUGF(TCP_DEBUG, ("Active PCB states:\n"));
donatien	0:632c9925f013	1523	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1524	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
donatien	0:632c9925f013	1525	pcb->local_port, pcb->remote_port,
donatien	0:632c9925f013	1526	pcb->snd_nxt, pcb->rcv_nxt));
donatien	0:632c9925f013	1527	tcp_debug_print_state(pcb->state);
donatien	0:632c9925f013	1528	}
donatien	0:632c9925f013	1529	LWIP_DEBUGF(TCP_DEBUG, ("Listen PCB states:\n"));
donatien	0:632c9925f013	1530	for(pcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1531	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
donatien	0:632c9925f013	1532	pcb->local_port, pcb->remote_port,
donatien	0:632c9925f013	1533	pcb->snd_nxt, pcb->rcv_nxt));
donatien	0:632c9925f013	1534	tcp_debug_print_state(pcb->state);
donatien	0:632c9925f013	1535	}
donatien	0:632c9925f013	1536	LWIP_DEBUGF(TCP_DEBUG, ("TIME-WAIT PCB states:\n"));
donatien	0:632c9925f013	1537	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1538	LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
donatien	0:632c9925f013	1539	pcb->local_port, pcb->remote_port,
donatien	0:632c9925f013	1540	pcb->snd_nxt, pcb->rcv_nxt));
donatien	0:632c9925f013	1541	tcp_debug_print_state(pcb->state);
donatien	0:632c9925f013	1542	}
donatien	0:632c9925f013	1543	}
donatien	0:632c9925f013	1544
donatien	0:632c9925f013	1545	/**
donatien	0:632c9925f013	1546	* Check state consistency of the tcp_pcb lists.
donatien	0:632c9925f013	1547	*/
donatien	0:632c9925f013	1548	s16_t
donatien	0:632c9925f013	1549	tcp_pcbs_sane(void)
donatien	0:632c9925f013	1550	{
donatien	0:632c9925f013	1551	struct tcp_pcb *pcb;
donatien	0:632c9925f013	1552	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1553	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != CLOSED", pcb->state != CLOSED);
donatien	0:632c9925f013	1554	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != LISTEN", pcb->state != LISTEN);
donatien	0:632c9925f013	1555	LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT);
donatien	0:632c9925f013	1556	}
donatien	0:632c9925f013	1557	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
donatien	0:632c9925f013	1558	LWIP_ASSERT("tcp_pcbs_sane: tw pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
donatien	0:632c9925f013	1559	}
donatien	0:632c9925f013	1560	return 1;
donatien	0:632c9925f013	1561	}
donatien	0:632c9925f013	1562	#endif /* TCP_DEBUG */
donatien	0:632c9925f013	1563
donatien	0:632c9925f013	1564	#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

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lwip/core/tcp.c@0:632c9925f013, 2010-06-11 (annotated)

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