UDPtest - Some quick code to use UDP-only (no TCP) with mBe…

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Some quick code to use UDP-only (no TCP) with mBed. Echos received packets and sends packets when a button is pressed

Core/lwIP/core/tcp_in.c@0:a548a085de55, 2010-03-14 (annotated)

Committer:: pehrhovey
Date:: Sun Mar 14 00:54:12 2010 +0000
Revision:: 0:a548a085de55

Who changed what in which revision?

User	Revision	Line number	New contents of line
pehrhovey	0:a548a085de55	1	/**
pehrhovey	0:a548a085de55	2	* @file
pehrhovey	0:a548a085de55	3	* Transmission Control Protocol, incoming traffic
pehrhovey	0:a548a085de55	4	*
pehrhovey	0:a548a085de55	5	* The input processing functions of the TCP layer.
pehrhovey	0:a548a085de55	6	*
pehrhovey	0:a548a085de55	7	* These functions are generally called in the order (ip_input() ->)
pehrhovey	0:a548a085de55	8	* tcp_input() -> * tcp_process() -> tcp_receive() (-> application).
pehrhovey	0:a548a085de55	9	*
pehrhovey	0:a548a085de55	10	*/
pehrhovey	0:a548a085de55	11
pehrhovey	0:a548a085de55	12	/*
pehrhovey	0:a548a085de55	13	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
pehrhovey	0:a548a085de55	14	* All rights reserved.
pehrhovey	0:a548a085de55	15	*
pehrhovey	0:a548a085de55	16	* Redistribution and use in source and binary forms, with or without modification,
pehrhovey	0:a548a085de55	17	* are permitted provided that the following conditions are met:
pehrhovey	0:a548a085de55	18	*
pehrhovey	0:a548a085de55	19	* 1. Redistributions of source code must retain the above copyright notice,
pehrhovey	0:a548a085de55	20	* this list of conditions and the following disclaimer.
pehrhovey	0:a548a085de55	21	* 2. Redistributions in binary form must reproduce the above copyright notice,
pehrhovey	0:a548a085de55	22	* this list of conditions and the following disclaimer in the documentation
pehrhovey	0:a548a085de55	23	* and/or other materials provided with the distribution.
pehrhovey	0:a548a085de55	24	* 3. The name of the author may not be used to endorse or promote products
pehrhovey	0:a548a085de55	25	* derived from this software without specific prior written permission.
pehrhovey	0:a548a085de55	26	*
pehrhovey	0:a548a085de55	27	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
pehrhovey	0:a548a085de55	28	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
pehrhovey	0:a548a085de55	29	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
pehrhovey	0:a548a085de55	30	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
pehrhovey	0:a548a085de55	31	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
pehrhovey	0:a548a085de55	32	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
pehrhovey	0:a548a085de55	33	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
pehrhovey	0:a548a085de55	34	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
pehrhovey	0:a548a085de55	35	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
pehrhovey	0:a548a085de55	36	* OF SUCH DAMAGE.
pehrhovey	0:a548a085de55	37	*
pehrhovey	0:a548a085de55	38	* This file is part of the lwIP TCP/IP stack.
pehrhovey	0:a548a085de55	39	*
pehrhovey	0:a548a085de55	40	* Author: Adam Dunkels <adam@sics.se>
pehrhovey	0:a548a085de55	41	*
pehrhovey	0:a548a085de55	42	*/
pehrhovey	0:a548a085de55	43
pehrhovey	0:a548a085de55	44	#include "lwip/opt.h"
pehrhovey	0:a548a085de55	45
pehrhovey	0:a548a085de55	46	#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
pehrhovey	0:a548a085de55	47
pehrhovey	0:a548a085de55	48	#include "lwip/tcp.h"
pehrhovey	0:a548a085de55	49	#include "lwip/def.h"
pehrhovey	0:a548a085de55	50	#include "lwip/ip_addr.h"
pehrhovey	0:a548a085de55	51	#include "lwip/netif.h"
pehrhovey	0:a548a085de55	52	#include "lwip/mem.h"
pehrhovey	0:a548a085de55	53	#include "lwip/memp.h"
pehrhovey	0:a548a085de55	54	#include "lwip/inet.h"
pehrhovey	0:a548a085de55	55	#include "lwip/inet_chksum.h"
pehrhovey	0:a548a085de55	56	#include "lwip/stats.h"
pehrhovey	0:a548a085de55	57	#include "lwip/snmp.h"
pehrhovey	0:a548a085de55	58	#include "arch/perf.h"
pehrhovey	0:a548a085de55	59
pehrhovey	0:a548a085de55	60	/* These variables are global to all functions involved in the input
pehrhovey	0:a548a085de55	61	processing of TCP segments. They are set by the tcp_input()
pehrhovey	0:a548a085de55	62	function. */
pehrhovey	0:a548a085de55	63	static struct tcp_seg inseg;
pehrhovey	0:a548a085de55	64	static struct tcp_hdr *tcphdr;
pehrhovey	0:a548a085de55	65	static struct ip_hdr *iphdr;
pehrhovey	0:a548a085de55	66	static u32_t seqno, ackno;
pehrhovey	0:a548a085de55	67	static u8_t flags;
pehrhovey	0:a548a085de55	68	static u16_t tcplen;
pehrhovey	0:a548a085de55	69
pehrhovey	0:a548a085de55	70	static u8_t recv_flags;
pehrhovey	0:a548a085de55	71	static struct pbuf *recv_data;
pehrhovey	0:a548a085de55	72
pehrhovey	0:a548a085de55	73	struct tcp_pcb *tcp_input_pcb;
pehrhovey	0:a548a085de55	74
pehrhovey	0:a548a085de55	75	/* Forward declarations. */
pehrhovey	0:a548a085de55	76	static err_t tcp_process(struct tcp_pcb *pcb);
pehrhovey	0:a548a085de55	77	static u8_t tcp_receive(struct tcp_pcb *pcb);
pehrhovey	0:a548a085de55	78	static void tcp_parseopt(struct tcp_pcb *pcb);
pehrhovey	0:a548a085de55	79
pehrhovey	0:a548a085de55	80	static err_t tcp_listen_input(struct tcp_pcb_listen *pcb);
pehrhovey	0:a548a085de55	81	static err_t tcp_timewait_input(struct tcp_pcb *pcb);
pehrhovey	0:a548a085de55	82
pehrhovey	0:a548a085de55	83	/**
pehrhovey	0:a548a085de55	84	* The initial input processing of TCP. It verifies the TCP header, demultiplexes
pehrhovey	0:a548a085de55	85	* the segment between the PCBs and passes it on to tcp_process(), which implements
pehrhovey	0:a548a085de55	86	* the TCP finite state machine. This function is called by the IP layer (in
pehrhovey	0:a548a085de55	87	* ip_input()).
pehrhovey	0:a548a085de55	88	*
pehrhovey	0:a548a085de55	89	* @param p received TCP segment to process (p->payload pointing to the IP header)
pehrhovey	0:a548a085de55	90	* @param inp network interface on which this segment was received
pehrhovey	0:a548a085de55	91	*/
pehrhovey	0:a548a085de55	92	void
pehrhovey	0:a548a085de55	93	tcp_input(struct pbuf p, struct netif inp)
pehrhovey	0:a548a085de55	94	{
pehrhovey	0:a548a085de55	95	struct tcp_pcb pcb, prev;
pehrhovey	0:a548a085de55	96	struct tcp_pcb_listen *lpcb;
pehrhovey	0:a548a085de55	97	u8_t hdrlen;
pehrhovey	0:a548a085de55	98	err_t err;
pehrhovey	0:a548a085de55	99
pehrhovey	0:a548a085de55	100	PERF_START;
pehrhovey	0:a548a085de55	101
pehrhovey	0:a548a085de55	102	TCP_STATS_INC(tcp.recv);
pehrhovey	0:a548a085de55	103	snmp_inc_tcpinsegs();
pehrhovey	0:a548a085de55	104
pehrhovey	0:a548a085de55	105	iphdr = (struct ip_hdr *)p->payload;
pehrhovey	0:a548a085de55	106	tcphdr = (struct tcp_hdr )((u8_t )p->payload + IPH_HL(iphdr) * 4);
pehrhovey	0:a548a085de55	107
pehrhovey	0:a548a085de55	108	#if TCP_INPUT_DEBUG
pehrhovey	0:a548a085de55	109	tcp_debug_print(tcphdr);
pehrhovey	0:a548a085de55	110	#endif
pehrhovey	0:a548a085de55	111
pehrhovey	0:a548a085de55	112	/* remove header from payload */
pehrhovey	0:a548a085de55	113	if (pbuf_header(p, -((s16_t)(IPH_HL(iphdr) * 4))) \|\| (p->tot_len < sizeof(struct tcp_hdr))) {
pehrhovey	0:a548a085de55	114	/* drop short packets */
pehrhovey	0:a548a085de55	115	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: short packet (%"U16_F" bytes) discarded\n", p->tot_len));
pehrhovey	0:a548a085de55	116	TCP_STATS_INC(tcp.lenerr);
pehrhovey	0:a548a085de55	117	TCP_STATS_INC(tcp.drop);
pehrhovey	0:a548a085de55	118	snmp_inc_tcpinerrs();
pehrhovey	0:a548a085de55	119	pbuf_free(p);
pehrhovey	0:a548a085de55	120	return;
pehrhovey	0:a548a085de55	121	}
pehrhovey	0:a548a085de55	122
pehrhovey	0:a548a085de55	123	/* Don't even process incoming broadcasts/multicasts. */
pehrhovey	0:a548a085de55	124	if (ip_addr_isbroadcast(&(iphdr->dest), inp) \|\|
pehrhovey	0:a548a085de55	125	ip_addr_ismulticast(&(iphdr->dest))) {
pehrhovey	0:a548a085de55	126	TCP_STATS_INC(tcp.proterr);
pehrhovey	0:a548a085de55	127	TCP_STATS_INC(tcp.drop);
pehrhovey	0:a548a085de55	128	snmp_inc_tcpinerrs();
pehrhovey	0:a548a085de55	129	pbuf_free(p);
pehrhovey	0:a548a085de55	130	return;
pehrhovey	0:a548a085de55	131	}
pehrhovey	0:a548a085de55	132
pehrhovey	0:a548a085de55	133	#if CHECKSUM_CHECK_TCP
pehrhovey	0:a548a085de55	134	/* Verify TCP checksum. */
pehrhovey	0:a548a085de55	135	if (inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src),
pehrhovey	0:a548a085de55	136	(struct ip_addr *)&(iphdr->dest),
pehrhovey	0:a548a085de55	137	IP_PROTO_TCP, p->tot_len) != 0) {
pehrhovey	0:a548a085de55	138	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packet discarded due to failing checksum 0x%04"X16_F"\n",
pehrhovey	0:a548a085de55	139	inet_chksum_pseudo(p, (struct ip_addr )&(iphdr->src), (struct ip_addr )&(iphdr->dest),
pehrhovey	0:a548a085de55	140	IP_PROTO_TCP, p->tot_len)));
pehrhovey	0:a548a085de55	141	#if TCP_DEBUG
pehrhovey	0:a548a085de55	142	tcp_debug_print(tcphdr);
pehrhovey	0:a548a085de55	143	#endif /* TCP_DEBUG */
pehrhovey	0:a548a085de55	144	TCP_STATS_INC(tcp.chkerr);
pehrhovey	0:a548a085de55	145	TCP_STATS_INC(tcp.drop);
pehrhovey	0:a548a085de55	146	snmp_inc_tcpinerrs();
pehrhovey	0:a548a085de55	147	pbuf_free(p);
pehrhovey	0:a548a085de55	148	return;
pehrhovey	0:a548a085de55	149	}
pehrhovey	0:a548a085de55	150	#endif
pehrhovey	0:a548a085de55	151
pehrhovey	0:a548a085de55	152	/* Move the payload pointer in the pbuf so that it points to the
pehrhovey	0:a548a085de55	153	TCP data instead of the TCP header. */
pehrhovey	0:a548a085de55	154	hdrlen = TCPH_HDRLEN(tcphdr);
pehrhovey	0:a548a085de55	155	if(pbuf_header(p, -(hdrlen * 4))){
pehrhovey	0:a548a085de55	156	/* drop short packets */
pehrhovey	0:a548a085de55	157	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: short packet\n"));
pehrhovey	0:a548a085de55	158	TCP_STATS_INC(tcp.lenerr);
pehrhovey	0:a548a085de55	159	TCP_STATS_INC(tcp.drop);
pehrhovey	0:a548a085de55	160	snmp_inc_tcpinerrs();
pehrhovey	0:a548a085de55	161	pbuf_free(p);
pehrhovey	0:a548a085de55	162	return;
pehrhovey	0:a548a085de55	163	}
pehrhovey	0:a548a085de55	164
pehrhovey	0:a548a085de55	165	/* Convert fields in TCP header to host byte order. */
pehrhovey	0:a548a085de55	166	tcphdr->src = ntohs(tcphdr->src);
pehrhovey	0:a548a085de55	167	tcphdr->dest = ntohs(tcphdr->dest);
pehrhovey	0:a548a085de55	168	seqno = tcphdr->seqno = ntohl(tcphdr->seqno);
pehrhovey	0:a548a085de55	169	ackno = tcphdr->ackno = ntohl(tcphdr->ackno);
pehrhovey	0:a548a085de55	170	tcphdr->wnd = ntohs(tcphdr->wnd);
pehrhovey	0:a548a085de55	171
pehrhovey	0:a548a085de55	172	flags = TCPH_FLAGS(tcphdr);
pehrhovey	0:a548a085de55	173	tcplen = p->tot_len + ((flags & (TCP_FIN \| TCP_SYN)) ? 1 : 0);
pehrhovey	0:a548a085de55	174
pehrhovey	0:a548a085de55	175	/* Demultiplex an incoming segment. First, we check if it is destined
pehrhovey	0:a548a085de55	176	for an active connection. */
pehrhovey	0:a548a085de55	177	prev = NULL;
pehrhovey	0:a548a085de55	178
pehrhovey	0:a548a085de55	179
pehrhovey	0:a548a085de55	180	for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
pehrhovey	0:a548a085de55	181	LWIP_ASSERT("tcp_input: active pcb->state != CLOSED", pcb->state != CLOSED);
pehrhovey	0:a548a085de55	182	LWIP_ASSERT("tcp_input: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT);
pehrhovey	0:a548a085de55	183	LWIP_ASSERT("tcp_input: active pcb->state != LISTEN", pcb->state != LISTEN);
pehrhovey	0:a548a085de55	184	if (pcb->remote_port == tcphdr->src &&
pehrhovey	0:a548a085de55	185	pcb->local_port == tcphdr->dest &&
pehrhovey	0:a548a085de55	186	ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src)) &&
pehrhovey	0:a548a085de55	187	ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest))) {
pehrhovey	0:a548a085de55	188
pehrhovey	0:a548a085de55	189	/* Move this PCB to the front of the list so that subsequent
pehrhovey	0:a548a085de55	190	lookups will be faster (we exploit locality in TCP segment
pehrhovey	0:a548a085de55	191	arrivals). */
pehrhovey	0:a548a085de55	192	LWIP_ASSERT("tcp_input: pcb->next != pcb (before cache)", pcb->next != pcb);
pehrhovey	0:a548a085de55	193	if (prev != NULL) {
pehrhovey	0:a548a085de55	194	prev->next = pcb->next;
pehrhovey	0:a548a085de55	195	pcb->next = tcp_active_pcbs;
pehrhovey	0:a548a085de55	196	tcp_active_pcbs = pcb;
pehrhovey	0:a548a085de55	197	}
pehrhovey	0:a548a085de55	198	LWIP_ASSERT("tcp_input: pcb->next != pcb (after cache)", pcb->next != pcb);
pehrhovey	0:a548a085de55	199	break;
pehrhovey	0:a548a085de55	200	}
pehrhovey	0:a548a085de55	201	prev = pcb;
pehrhovey	0:a548a085de55	202	}
pehrhovey	0:a548a085de55	203
pehrhovey	0:a548a085de55	204	if (pcb == NULL) {
pehrhovey	0:a548a085de55	205	/* If it did not go to an active connection, we check the connections
pehrhovey	0:a548a085de55	206	in the TIME-WAIT state. */
pehrhovey	0:a548a085de55	207	for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
pehrhovey	0:a548a085de55	208	LWIP_ASSERT("tcp_input: TIME-WAIT pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
pehrhovey	0:a548a085de55	209	if (pcb->remote_port == tcphdr->src &&
pehrhovey	0:a548a085de55	210	pcb->local_port == tcphdr->dest &&
pehrhovey	0:a548a085de55	211	ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src)) &&
pehrhovey	0:a548a085de55	212	ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest))) {
pehrhovey	0:a548a085de55	213	/* We don't really care enough to move this PCB to the front
pehrhovey	0:a548a085de55	214	of the list since we are not very likely to receive that
pehrhovey	0:a548a085de55	215	many segments for connections in TIME-WAIT. */
pehrhovey	0:a548a085de55	216	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packed for TIME_WAITing connection.\n"));
pehrhovey	0:a548a085de55	217	tcp_timewait_input(pcb);
pehrhovey	0:a548a085de55	218	pbuf_free(p);
pehrhovey	0:a548a085de55	219	return;
pehrhovey	0:a548a085de55	220	}
pehrhovey	0:a548a085de55	221	}
pehrhovey	0:a548a085de55	222
pehrhovey	0:a548a085de55	223	/* Finally, if we still did not get a match, we check all PCBs that
pehrhovey	0:a548a085de55	224	are LISTENing for incoming connections. */
pehrhovey	0:a548a085de55	225	prev = NULL;
pehrhovey	0:a548a085de55	226	for(lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
pehrhovey	0:a548a085de55	227	if ((ip_addr_isany(&(lpcb->local_ip)) \|\|
pehrhovey	0:a548a085de55	228	ip_addr_cmp(&(lpcb->local_ip), &(iphdr->dest))) &&
pehrhovey	0:a548a085de55	229	lpcb->local_port == tcphdr->dest) {
pehrhovey	0:a548a085de55	230	/* Move this PCB to the front of the list so that subsequent
pehrhovey	0:a548a085de55	231	lookups will be faster (we exploit locality in TCP segment
pehrhovey	0:a548a085de55	232	arrivals). */
pehrhovey	0:a548a085de55	233	if (prev != NULL) {
pehrhovey	0:a548a085de55	234	((struct tcp_pcb_listen *)prev)->next = lpcb->next;
pehrhovey	0:a548a085de55	235	/* our successor is the remainder of the listening list */
pehrhovey	0:a548a085de55	236	lpcb->next = tcp_listen_pcbs.listen_pcbs;
pehrhovey	0:a548a085de55	237	/* put this listening pcb at the head of the listening list */
pehrhovey	0:a548a085de55	238	tcp_listen_pcbs.listen_pcbs = lpcb;
pehrhovey	0:a548a085de55	239	}
pehrhovey	0:a548a085de55	240
pehrhovey	0:a548a085de55	241	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packed for LISTENing connection.\n"));
pehrhovey	0:a548a085de55	242	tcp_listen_input(lpcb);
pehrhovey	0:a548a085de55	243	pbuf_free(p);
pehrhovey	0:a548a085de55	244	return;
pehrhovey	0:a548a085de55	245	}
pehrhovey	0:a548a085de55	246	prev = (struct tcp_pcb *)lpcb;
pehrhovey	0:a548a085de55	247	}
pehrhovey	0:a548a085de55	248	}
pehrhovey	0:a548a085de55	249
pehrhovey	0:a548a085de55	250	#if TCP_INPUT_DEBUG
pehrhovey	0:a548a085de55	251	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("+-+-+-+-+-+-+-+-+-+-+-+-+-+- tcp_input: flags "));
pehrhovey	0:a548a085de55	252	tcp_debug_print_flags(TCPH_FLAGS(tcphdr));
pehrhovey	0:a548a085de55	253	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("-+-+-+-+-+-+-+-+-+-+-+-+-+-+\n"));
pehrhovey	0:a548a085de55	254	#endif /* TCP_INPUT_DEBUG */
pehrhovey	0:a548a085de55	255
pehrhovey	0:a548a085de55	256
pehrhovey	0:a548a085de55	257	if (pcb != NULL) {
pehrhovey	0:a548a085de55	258	/* The incoming segment belongs to a connection. */
pehrhovey	0:a548a085de55	259	#if TCP_INPUT_DEBUG
pehrhovey	0:a548a085de55	260	#if TCP_DEBUG
pehrhovey	0:a548a085de55	261	tcp_debug_print_state(pcb->state);
pehrhovey	0:a548a085de55	262	#endif /* TCP_DEBUG */
pehrhovey	0:a548a085de55	263	#endif /* TCP_INPUT_DEBUG */
pehrhovey	0:a548a085de55	264
pehrhovey	0:a548a085de55	265	/* Set up a tcp_seg structure. */
pehrhovey	0:a548a085de55	266	inseg.next = NULL;
pehrhovey	0:a548a085de55	267	inseg.len = p->tot_len;
pehrhovey	0:a548a085de55	268	inseg.dataptr = p->payload;
pehrhovey	0:a548a085de55	269	inseg.p = p;
pehrhovey	0:a548a085de55	270	inseg.tcphdr = tcphdr;
pehrhovey	0:a548a085de55	271
pehrhovey	0:a548a085de55	272	recv_data = NULL;
pehrhovey	0:a548a085de55	273	recv_flags = 0;
pehrhovey	0:a548a085de55	274
pehrhovey	0:a548a085de55	275	/* If there is data which was previously "refused" by upper layer */
pehrhovey	0:a548a085de55	276	if (pcb->refused_data != NULL) {
pehrhovey	0:a548a085de55	277	/* Notify again application with data previously received. */
pehrhovey	0:a548a085de55	278	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: notify kept packet\n"));
pehrhovey	0:a548a085de55	279	TCP_EVENT_RECV(pcb, pcb->refused_data, ERR_OK, err);
pehrhovey	0:a548a085de55	280	if (err == ERR_OK) {
pehrhovey	0:a548a085de55	281	pcb->refused_data = NULL;
pehrhovey	0:a548a085de55	282	} else {
pehrhovey	0:a548a085de55	283	/* drop incoming packets, because pcb is "full" */
pehrhovey	0:a548a085de55	284	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: drop incoming packets, because pcb is \"full\"\n"));
pehrhovey	0:a548a085de55	285	TCP_STATS_INC(tcp.drop);
pehrhovey	0:a548a085de55	286	snmp_inc_tcpinerrs();
pehrhovey	0:a548a085de55	287	pbuf_free(p);
pehrhovey	0:a548a085de55	288	return;
pehrhovey	0:a548a085de55	289	}
pehrhovey	0:a548a085de55	290	}
pehrhovey	0:a548a085de55	291	tcp_input_pcb = pcb;
pehrhovey	0:a548a085de55	292	err = tcp_process(pcb);
pehrhovey	0:a548a085de55	293	tcp_input_pcb = NULL;
pehrhovey	0:a548a085de55	294	/* A return value of ERR_ABRT means that tcp_abort() was called
pehrhovey	0:a548a085de55	295	and that the pcb has been freed. If so, we don't do anything. */
pehrhovey	0:a548a085de55	296	if (err != ERR_ABRT) {
pehrhovey	0:a548a085de55	297	if (recv_flags & TF_RESET) {
pehrhovey	0:a548a085de55	298	/* TF_RESET means that the connection was reset by the other
pehrhovey	0:a548a085de55	299	end. We then call the error callback to inform the
pehrhovey	0:a548a085de55	300	application that the connection is dead before we
pehrhovey	0:a548a085de55	301	deallocate the PCB. */
pehrhovey	0:a548a085de55	302	TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_RST);
pehrhovey	0:a548a085de55	303	tcp_pcb_remove(&tcp_active_pcbs, pcb);
pehrhovey	0:a548a085de55	304	memp_free(MEMP_TCP_PCB, pcb);
pehrhovey	0:a548a085de55	305	} else if (recv_flags & TF_CLOSED) {
pehrhovey	0:a548a085de55	306	/* The connection has been closed and we will deallocate the
pehrhovey	0:a548a085de55	307	PCB. */
pehrhovey	0:a548a085de55	308	tcp_pcb_remove(&tcp_active_pcbs, pcb);
pehrhovey	0:a548a085de55	309	memp_free(MEMP_TCP_PCB, pcb);
pehrhovey	0:a548a085de55	310	} else {
pehrhovey	0:a548a085de55	311	err = ERR_OK;
pehrhovey	0:a548a085de55	312	/* If the application has registered a "sent" function to be
pehrhovey	0:a548a085de55	313	called when new send buffer space is available, we call it
pehrhovey	0:a548a085de55	314	now. */
pehrhovey	0:a548a085de55	315	if (pcb->acked > 0) {
pehrhovey	0:a548a085de55	316	TCP_EVENT_SENT(pcb, pcb->acked, err);
pehrhovey	0:a548a085de55	317	}
pehrhovey	0:a548a085de55	318
pehrhovey	0:a548a085de55	319	if (recv_data != NULL) {
pehrhovey	0:a548a085de55	320	if(flags & TCP_PSH) {
pehrhovey	0:a548a085de55	321	recv_data->flags \|= PBUF_FLAG_PUSH;
pehrhovey	0:a548a085de55	322	}
pehrhovey	0:a548a085de55	323
pehrhovey	0:a548a085de55	324	/* Notify application that data has been received. */
pehrhovey	0:a548a085de55	325	TCP_EVENT_RECV(pcb, recv_data, ERR_OK, err);
pehrhovey	0:a548a085de55	326
pehrhovey	0:a548a085de55	327	/* If the upper layer can't receive this data, store it */
pehrhovey	0:a548a085de55	328	if (err != ERR_OK) {
pehrhovey	0:a548a085de55	329	pcb->refused_data = recv_data;
pehrhovey	0:a548a085de55	330	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: keep incoming packet, because pcb is \"full\"\n"));
pehrhovey	0:a548a085de55	331	}
pehrhovey	0:a548a085de55	332	}
pehrhovey	0:a548a085de55	333
pehrhovey	0:a548a085de55	334	/* If a FIN segment was received, we call the callback
pehrhovey	0:a548a085de55	335	function with a NULL buffer to indicate EOF. */
pehrhovey	0:a548a085de55	336	if (recv_flags & TF_GOT_FIN) {
pehrhovey	0:a548a085de55	337	TCP_EVENT_RECV(pcb, NULL, ERR_OK, err);
pehrhovey	0:a548a085de55	338	}
pehrhovey	0:a548a085de55	339
pehrhovey	0:a548a085de55	340	/* If there were no errors, we try to send something out. */
pehrhovey	0:a548a085de55	341	if (err == ERR_OK) {
pehrhovey	0:a548a085de55	342	tcp_output(pcb);
pehrhovey	0:a548a085de55	343	}
pehrhovey	0:a548a085de55	344	}
pehrhovey	0:a548a085de55	345	}
pehrhovey	0:a548a085de55	346
pehrhovey	0:a548a085de55	347
pehrhovey	0:a548a085de55	348	/* give up our reference to inseg.p */
pehrhovey	0:a548a085de55	349	if (inseg.p != NULL)
pehrhovey	0:a548a085de55	350	{
pehrhovey	0:a548a085de55	351	pbuf_free(inseg.p);
pehrhovey	0:a548a085de55	352	inseg.p = NULL;
pehrhovey	0:a548a085de55	353	}
pehrhovey	0:a548a085de55	354	#if TCP_INPUT_DEBUG
pehrhovey	0:a548a085de55	355	#if TCP_DEBUG
pehrhovey	0:a548a085de55	356	tcp_debug_print_state(pcb->state);
pehrhovey	0:a548a085de55	357	#endif /* TCP_DEBUG */
pehrhovey	0:a548a085de55	358	#endif /* TCP_INPUT_DEBUG */
pehrhovey	0:a548a085de55	359
pehrhovey	0:a548a085de55	360	} else {
pehrhovey	0:a548a085de55	361
pehrhovey	0:a548a085de55	362	/* If no matching PCB was found, send a TCP RST (reset) to the
pehrhovey	0:a548a085de55	363	sender. */
pehrhovey	0:a548a085de55	364	LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_input: no PCB match found, resetting.\n"));
pehrhovey	0:a548a085de55	365	if (!(TCPH_FLAGS(tcphdr) & TCP_RST)) {
pehrhovey	0:a548a085de55	366	TCP_STATS_INC(tcp.proterr);
pehrhovey	0:a548a085de55	367	TCP_STATS_INC(tcp.drop);
pehrhovey	0:a548a085de55	368	tcp_rst(ackno, seqno + tcplen,
pehrhovey	0:a548a085de55	369	&(iphdr->dest), &(iphdr->src),
pehrhovey	0:a548a085de55	370	tcphdr->dest, tcphdr->src);
pehrhovey	0:a548a085de55	371	}
pehrhovey	0:a548a085de55	372	pbuf_free(p);
pehrhovey	0:a548a085de55	373	}
pehrhovey	0:a548a085de55	374
pehrhovey	0:a548a085de55	375	LWIP_ASSERT("tcp_input: tcp_pcbs_sane()", tcp_pcbs_sane());
pehrhovey	0:a548a085de55	376	PERF_STOP("tcp_input");
pehrhovey	0:a548a085de55	377	}
pehrhovey	0:a548a085de55	378
pehrhovey	0:a548a085de55	379	/**
pehrhovey	0:a548a085de55	380	* Called by tcp_input() when a segment arrives for a listening
pehrhovey	0:a548a085de55	381	* connection (from tcp_input()).
pehrhovey	0:a548a085de55	382	*
pehrhovey	0:a548a085de55	383	* @param pcb the tcp_pcb_listen for which a segment arrived
pehrhovey	0:a548a085de55	384	* @return ERR_OK if the segment was processed
pehrhovey	0:a548a085de55	385	* another err_t on error
pehrhovey	0:a548a085de55	386	*
pehrhovey	0:a548a085de55	387	* @note the return value is not (yet?) used in tcp_input()
pehrhovey	0:a548a085de55	388	* @note the segment which arrived is saved in global variables, therefore only the pcb
pehrhovey	0:a548a085de55	389	* involved is passed as a parameter to this function
pehrhovey	0:a548a085de55	390	*/
pehrhovey	0:a548a085de55	391	static err_t
pehrhovey	0:a548a085de55	392	tcp_listen_input(struct tcp_pcb_listen *pcb)
pehrhovey	0:a548a085de55	393	{
pehrhovey	0:a548a085de55	394	struct tcp_pcb *npcb;
pehrhovey	0:a548a085de55	395	err_t rc;
pehrhovey	0:a548a085de55	396
pehrhovey	0:a548a085de55	397	/* In the LISTEN state, we check for incoming SYN segments,
pehrhovey	0:a548a085de55	398	creates a new PCB, and responds with a SYN\|ACK. */
pehrhovey	0:a548a085de55	399	if (flags & TCP_ACK) {
pehrhovey	0:a548a085de55	400	/* For incoming segments with the ACK flag set, respond with a
pehrhovey	0:a548a085de55	401	RST. */
pehrhovey	0:a548a085de55	402	LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_listen_input: ACK in LISTEN, sending reset\n"));
pehrhovey	0:a548a085de55	403	tcp_rst(ackno + 1, seqno + tcplen,
pehrhovey	0:a548a085de55	404	&(iphdr->dest), &(iphdr->src),
pehrhovey	0:a548a085de55	405	tcphdr->dest, tcphdr->src);
pehrhovey	0:a548a085de55	406	} else if (flags & TCP_SYN) {
pehrhovey	0:a548a085de55	407	LWIP_DEBUGF(TCP_DEBUG, ("TCP connection request %"U16_F" -> %"U16_F".\n", tcphdr->src, tcphdr->dest));
pehrhovey	0:a548a085de55	408	#if TCP_LISTEN_BACKLOG
pehrhovey	0:a548a085de55	409	if (pcb->accepts_pending >= pcb->backlog) {
pehrhovey	0:a548a085de55	410	LWIP_DEBUGF(TCP_DEBUG, ("tcp_listen_input: listen backlog exceeded for port %"U16_F"\n", tcphdr->dest));
pehrhovey	0:a548a085de55	411	return ERR_ABRT;
pehrhovey	0:a548a085de55	412	}
pehrhovey	0:a548a085de55	413	#endif /* TCP_LISTEN_BACKLOG */
pehrhovey	0:a548a085de55	414	npcb = tcp_alloc(pcb->prio);
pehrhovey	0:a548a085de55	415	/* If a new PCB could not be created (probably due to lack of memory),
pehrhovey	0:a548a085de55	416	we don't do anything, but rely on the sender will retransmit the
pehrhovey	0:a548a085de55	417	SYN at a time when we have more memory available. */
pehrhovey	0:a548a085de55	418	if (npcb == NULL) {
pehrhovey	0:a548a085de55	419	LWIP_DEBUGF(TCP_DEBUG, ("tcp_listen_input: could not allocate PCB\n"));
pehrhovey	0:a548a085de55	420	TCP_STATS_INC(tcp.memerr);
pehrhovey	0:a548a085de55	421	return ERR_MEM;
pehrhovey	0:a548a085de55	422	}
pehrhovey	0:a548a085de55	423	#if TCP_LISTEN_BACKLOG
pehrhovey	0:a548a085de55	424	pcb->accepts_pending++;
pehrhovey	0:a548a085de55	425	#endif /* TCP_LISTEN_BACKLOG */
pehrhovey	0:a548a085de55	426	/* Set up the new PCB. */
pehrhovey	0:a548a085de55	427	ip_addr_set(&(npcb->local_ip), &(iphdr->dest));
pehrhovey	0:a548a085de55	428	npcb->local_port = pcb->local_port;
pehrhovey	0:a548a085de55	429	ip_addr_set(&(npcb->remote_ip), &(iphdr->src));
pehrhovey	0:a548a085de55	430	npcb->remote_port = tcphdr->src;
pehrhovey	0:a548a085de55	431	npcb->state = SYN_RCVD;
pehrhovey	0:a548a085de55	432	npcb->rcv_nxt = seqno + 1;
pehrhovey	0:a548a085de55	433	npcb->rcv_ann_right_edge = npcb->rcv_nxt;
pehrhovey	0:a548a085de55	434	npcb->snd_wnd = tcphdr->wnd;
pehrhovey	0:a548a085de55	435	npcb->ssthresh = npcb->snd_wnd;
pehrhovey	0:a548a085de55	436	npcb->snd_wl1 = seqno - 1;/* initialise to seqno-1 to force window update */
pehrhovey	0:a548a085de55	437	npcb->callback_arg = pcb->callback_arg;
pehrhovey	0:a548a085de55	438	#if LWIP_CALLBACK_API
pehrhovey	0:a548a085de55	439	npcb->accept = pcb->accept;
pehrhovey	0:a548a085de55	440	#endif /* LWIP_CALLBACK_API */
pehrhovey	0:a548a085de55	441	/* inherit socket options */
pehrhovey	0:a548a085de55	442	npcb->so_options = pcb->so_options & (SOF_DEBUG\|SOF_DONTROUTE\|SOF_KEEPALIVE\|SOF_OOBINLINE\|SOF_LINGER);
pehrhovey	0:a548a085de55	443	/* Register the new PCB so that we can begin receiving segments
pehrhovey	0:a548a085de55	444	for it. */
pehrhovey	0:a548a085de55	445	TCP_REG(&tcp_active_pcbs, npcb);
pehrhovey	0:a548a085de55	446
pehrhovey	0:a548a085de55	447	/* Parse any options in the SYN. */
pehrhovey	0:a548a085de55	448	tcp_parseopt(npcb);
pehrhovey	0:a548a085de55	449	#if TCP_CALCULATE_EFF_SEND_MSS
pehrhovey	0:a548a085de55	450	npcb->mss = tcp_eff_send_mss(npcb->mss, &(npcb->remote_ip));
pehrhovey	0:a548a085de55	451	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
pehrhovey	0:a548a085de55	452
pehrhovey	0:a548a085de55	453	snmp_inc_tcppassiveopens();
pehrhovey	0:a548a085de55	454
pehrhovey	0:a548a085de55	455	/* Send a SYN\|ACK together with the MSS option. */
pehrhovey	0:a548a085de55	456	rc = tcp_enqueue(npcb, NULL, 0, TCP_SYN \| TCP_ACK, 0, TF_SEG_OPTS_MSS
pehrhovey	0:a548a085de55	457	#if LWIP_TCP_TIMESTAMPS
pehrhovey	0:a548a085de55	458	/* and maybe include the TIMESTAMP option */
pehrhovey	0:a548a085de55	459	\| (npcb->flags & TF_TIMESTAMP ? TF_SEG_OPTS_TS : 0)
pehrhovey	0:a548a085de55	460	#endif
pehrhovey	0:a548a085de55	461	);
pehrhovey	0:a548a085de55	462	if (rc != ERR_OK) {
pehrhovey	0:a548a085de55	463	tcp_abandon(npcb, 0);
pehrhovey	0:a548a085de55	464	return rc;
pehrhovey	0:a548a085de55	465	}
pehrhovey	0:a548a085de55	466	return tcp_output(npcb);
pehrhovey	0:a548a085de55	467	}
pehrhovey	0:a548a085de55	468	return ERR_OK;
pehrhovey	0:a548a085de55	469	}
pehrhovey	0:a548a085de55	470
pehrhovey	0:a548a085de55	471	/**
pehrhovey	0:a548a085de55	472	* Called by tcp_input() when a segment arrives for a connection in
pehrhovey	0:a548a085de55	473	* TIME_WAIT.
pehrhovey	0:a548a085de55	474	*
pehrhovey	0:a548a085de55	475	* @param pcb the tcp_pcb for which a segment arrived
pehrhovey	0:a548a085de55	476	*
pehrhovey	0:a548a085de55	477	* @note the segment which arrived is saved in global variables, therefore only the pcb
pehrhovey	0:a548a085de55	478	* involved is passed as a parameter to this function
pehrhovey	0:a548a085de55	479	*/
pehrhovey	0:a548a085de55	480	static err_t
pehrhovey	0:a548a085de55	481	tcp_timewait_input(struct tcp_pcb *pcb)
pehrhovey	0:a548a085de55	482	{
pehrhovey	0:a548a085de55	483	/* RFC 1337: in TIME_WAIT, ignore RST and ACK FINs + any 'acceptable' segments */
pehrhovey	0:a548a085de55	484	/* RFC 793 3.9 Event Processing - Segment Arrives:
pehrhovey	0:a548a085de55	485	* - first check sequence number - we skip that one in TIME_WAIT (always
pehrhovey	0:a548a085de55	486	* acceptable since we only send ACKs)
pehrhovey	0:a548a085de55	487	* - second check the RST bit (... return) */
pehrhovey	0:a548a085de55	488	if (flags & TCP_RST) {
pehrhovey	0:a548a085de55	489	return ERR_OK;
pehrhovey	0:a548a085de55	490	}
pehrhovey	0:a548a085de55	491	/* - fourth, check the SYN bit, */
pehrhovey	0:a548a085de55	492	if (flags & TCP_SYN) {
pehrhovey	0:a548a085de55	493	/* If an incoming segment is not acceptable, an acknowledgment
pehrhovey	0:a548a085de55	494	should be sent in reply */
pehrhovey	0:a548a085de55	495	if (TCP_SEQ_BETWEEN(seqno, pcb->rcv_nxt, pcb->rcv_nxt+pcb->rcv_wnd)) {
pehrhovey	0:a548a085de55	496	/* If the SYN is in the window it is an error, send a reset */
pehrhovey	0:a548a085de55	497	tcp_rst(ackno, seqno + tcplen, &(iphdr->dest), &(iphdr->src),
pehrhovey	0:a548a085de55	498	tcphdr->dest, tcphdr->src);
pehrhovey	0:a548a085de55	499	return ERR_OK;
pehrhovey	0:a548a085de55	500	}
pehrhovey	0:a548a085de55	501	} else if (flags & TCP_FIN) {
pehrhovey	0:a548a085de55	502	/* - eighth, check the FIN bit: Remain in the TIME-WAIT state.
pehrhovey	0:a548a085de55	503	Restart the 2 MSL time-wait timeout.*/
pehrhovey	0:a548a085de55	504	pcb->tmr = tcp_ticks;
pehrhovey	0:a548a085de55	505	}
pehrhovey	0:a548a085de55	506
pehrhovey	0:a548a085de55	507	if ((tcplen > 0)) {
pehrhovey	0:a548a085de55	508	/* Acknowledge data, FIN or out-of-window SYN */
pehrhovey	0:a548a085de55	509	pcb->flags \|= TF_ACK_NOW;
pehrhovey	0:a548a085de55	510	return tcp_output(pcb);
pehrhovey	0:a548a085de55	511	}
pehrhovey	0:a548a085de55	512	return ERR_OK;
pehrhovey	0:a548a085de55	513	}
pehrhovey	0:a548a085de55	514
pehrhovey	0:a548a085de55	515	/**
pehrhovey	0:a548a085de55	516	* Implements the TCP state machine. Called by tcp_input. In some
pehrhovey	0:a548a085de55	517	* states tcp_receive() is called to receive data. The tcp_seg
pehrhovey	0:a548a085de55	518	* argument will be freed by the caller (tcp_input()) unless the
pehrhovey	0:a548a085de55	519	* recv_data pointer in the pcb is set.
pehrhovey	0:a548a085de55	520	*
pehrhovey	0:a548a085de55	521	* @param pcb the tcp_pcb for which a segment arrived
pehrhovey	0:a548a085de55	522	*
pehrhovey	0:a548a085de55	523	* @note the segment which arrived is saved in global variables, therefore only the pcb
pehrhovey	0:a548a085de55	524	* involved is passed as a parameter to this function
pehrhovey	0:a548a085de55	525	*/
pehrhovey	0:a548a085de55	526	static err_t
pehrhovey	0:a548a085de55	527	tcp_process(struct tcp_pcb *pcb)
pehrhovey	0:a548a085de55	528	{
pehrhovey	0:a548a085de55	529	struct tcp_seg *rseg;
pehrhovey	0:a548a085de55	530	u8_t acceptable = 0;
pehrhovey	0:a548a085de55	531	err_t err;
pehrhovey	0:a548a085de55	532
pehrhovey	0:a548a085de55	533	err = ERR_OK;
pehrhovey	0:a548a085de55	534
pehrhovey	0:a548a085de55	535	/* Process incoming RST segments. */
pehrhovey	0:a548a085de55	536	if (flags & TCP_RST) {
pehrhovey	0:a548a085de55	537	/* First, determine if the reset is acceptable. */
pehrhovey	0:a548a085de55	538	if (pcb->state == SYN_SENT) {
pehrhovey	0:a548a085de55	539	if (ackno == pcb->snd_nxt) {
pehrhovey	0:a548a085de55	540	acceptable = 1;
pehrhovey	0:a548a085de55	541	}
pehrhovey	0:a548a085de55	542	} else {
pehrhovey	0:a548a085de55	543	if (TCP_SEQ_BETWEEN(seqno, pcb->rcv_nxt,
pehrhovey	0:a548a085de55	544	pcb->rcv_nxt+pcb->rcv_wnd)) {
pehrhovey	0:a548a085de55	545	acceptable = 1;
pehrhovey	0:a548a085de55	546	}
pehrhovey	0:a548a085de55	547	}
pehrhovey	0:a548a085de55	548
pehrhovey	0:a548a085de55	549	if (acceptable) {
pehrhovey	0:a548a085de55	550	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_process: Connection RESET\n"));
pehrhovey	0:a548a085de55	551	LWIP_ASSERT("tcp_input: pcb->state != CLOSED", pcb->state != CLOSED);
pehrhovey	0:a548a085de55	552	recv_flags \|= TF_RESET;
pehrhovey	0:a548a085de55	553	pcb->flags &= ~TF_ACK_DELAY;
pehrhovey	0:a548a085de55	554	return ERR_RST;
pehrhovey	0:a548a085de55	555	} else {
pehrhovey	0:a548a085de55	556	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_process: unacceptable reset seqno %"U32_F" rcv_nxt %"U32_F"\n",
pehrhovey	0:a548a085de55	557	seqno, pcb->rcv_nxt));
pehrhovey	0:a548a085de55	558	LWIP_DEBUGF(TCP_DEBUG, ("tcp_process: unacceptable reset seqno %"U32_F" rcv_nxt %"U32_F"\n",
pehrhovey	0:a548a085de55	559	seqno, pcb->rcv_nxt));
pehrhovey	0:a548a085de55	560	return ERR_OK;
pehrhovey	0:a548a085de55	561	}
pehrhovey	0:a548a085de55	562	}
pehrhovey	0:a548a085de55	563
pehrhovey	0:a548a085de55	564	if ((flags & TCP_SYN) && (pcb->state != SYN_SENT && pcb->state != SYN_RCVD)) {
pehrhovey	0:a548a085de55	565	/* Cope with new connection attempt after remote end crashed */
pehrhovey	0:a548a085de55	566	tcp_ack_now(pcb);
pehrhovey	0:a548a085de55	567	return ERR_OK;
pehrhovey	0:a548a085de55	568	}
pehrhovey	0:a548a085de55	569
pehrhovey	0:a548a085de55	570	/* Update the PCB (in)activity timer. */
pehrhovey	0:a548a085de55	571	pcb->tmr = tcp_ticks;
pehrhovey	0:a548a085de55	572	pcb->keep_cnt_sent = 0;
pehrhovey	0:a548a085de55	573
pehrhovey	0:a548a085de55	574	tcp_parseopt(pcb);
pehrhovey	0:a548a085de55	575
pehrhovey	0:a548a085de55	576	/* Do different things depending on the TCP state. */
pehrhovey	0:a548a085de55	577	switch (pcb->state) {
pehrhovey	0:a548a085de55	578	case SYN_SENT:
pehrhovey	0:a548a085de55	579	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("SYN-SENT: ackno %"U32_F" pcb->snd_nxt %"U32_F" unacked %"U32_F"\n", ackno,
pehrhovey	0:a548a085de55	580	pcb->snd_nxt, ntohl(pcb->unacked->tcphdr->seqno)));
pehrhovey	0:a548a085de55	581	/* received SYN ACK with expected sequence number? */
pehrhovey	0:a548a085de55	582	if ((flags & TCP_ACK) && (flags & TCP_SYN)
pehrhovey	0:a548a085de55	583	&& ackno == ntohl(pcb->unacked->tcphdr->seqno) + 1) {
pehrhovey	0:a548a085de55	584	pcb->snd_buf++;
pehrhovey	0:a548a085de55	585	pcb->rcv_nxt = seqno + 1;
pehrhovey	0:a548a085de55	586	pcb->rcv_ann_right_edge = pcb->rcv_nxt;
pehrhovey	0:a548a085de55	587	pcb->lastack = ackno;
pehrhovey	0:a548a085de55	588	pcb->snd_wnd = tcphdr->wnd;
pehrhovey	0:a548a085de55	589	pcb->snd_wl1 = seqno - 1; /* initialise to seqno - 1 to force window update */
pehrhovey	0:a548a085de55	590	pcb->state = ESTABLISHED;
pehrhovey	0:a548a085de55	591
pehrhovey	0:a548a085de55	592	#if TCP_CALCULATE_EFF_SEND_MSS
pehrhovey	0:a548a085de55	593	pcb->mss = tcp_eff_send_mss(pcb->mss, &(pcb->remote_ip));
pehrhovey	0:a548a085de55	594	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
pehrhovey	0:a548a085de55	595
pehrhovey	0:a548a085de55	596	/* Set ssthresh again after changing pcb->mss (already set in tcp_connect
pehrhovey	0:a548a085de55	597	* but for the default value of pcb->mss) */
pehrhovey	0:a548a085de55	598	pcb->ssthresh = pcb->mss * 10;
pehrhovey	0:a548a085de55	599
pehrhovey	0:a548a085de55	600	pcb->cwnd = ((pcb->cwnd == 1) ? (pcb->mss * 2) : pcb->mss);
pehrhovey	0:a548a085de55	601	LWIP_ASSERT("pcb->snd_queuelen > 0", (pcb->snd_queuelen > 0));
pehrhovey	0:a548a085de55	602	--pcb->snd_queuelen;
pehrhovey	0:a548a085de55	603	LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_process: SYN-SENT --queuelen %"U16_F"\n", (u16_t)pcb->snd_queuelen));
pehrhovey	0:a548a085de55	604	rseg = pcb->unacked;
pehrhovey	0:a548a085de55	605	pcb->unacked = rseg->next;
pehrhovey	0:a548a085de55	606
pehrhovey	0:a548a085de55	607	/* If there's nothing left to acknowledge, stop the retransmit
pehrhovey	0:a548a085de55	608	timer, otherwise reset it to start again */
pehrhovey	0:a548a085de55	609	if(pcb->unacked == NULL)
pehrhovey	0:a548a085de55	610	pcb->rtime = -1;
pehrhovey	0:a548a085de55	611	else {
pehrhovey	0:a548a085de55	612	pcb->rtime = 0;
pehrhovey	0:a548a085de55	613	pcb->nrtx = 0;
pehrhovey	0:a548a085de55	614	}
pehrhovey	0:a548a085de55	615
pehrhovey	0:a548a085de55	616	tcp_seg_free(rseg);
pehrhovey	0:a548a085de55	617
pehrhovey	0:a548a085de55	618	/* Call the user specified function to call when sucessfully
pehrhovey	0:a548a085de55	619	* connected. */
pehrhovey	0:a548a085de55	620	TCP_EVENT_CONNECTED(pcb, ERR_OK, err);
pehrhovey	0:a548a085de55	621	tcp_ack_now(pcb);
pehrhovey	0:a548a085de55	622	}
pehrhovey	0:a548a085de55	623	/* received ACK? possibly a half-open connection */
pehrhovey	0:a548a085de55	624	else if (flags & TCP_ACK) {
pehrhovey	0:a548a085de55	625	/* send a RST to bring the other side in a non-synchronized state. */
pehrhovey	0:a548a085de55	626	tcp_rst(ackno, seqno + tcplen, &(iphdr->dest), &(iphdr->src),
pehrhovey	0:a548a085de55	627	tcphdr->dest, tcphdr->src);
pehrhovey	0:a548a085de55	628	}
pehrhovey	0:a548a085de55	629	break;
pehrhovey	0:a548a085de55	630	case SYN_RCVD:
pehrhovey	0:a548a085de55	631	if (flags & TCP_ACK) {
pehrhovey	0:a548a085de55	632	/* expected ACK number? */
pehrhovey	0:a548a085de55	633	if (TCP_SEQ_BETWEEN(ackno, pcb->lastack+1, pcb->snd_nxt)) {
pehrhovey	0:a548a085de55	634	u16_t old_cwnd;
pehrhovey	0:a548a085de55	635	pcb->state = ESTABLISHED;
pehrhovey	0:a548a085de55	636	LWIP_DEBUGF(TCP_DEBUG, ("TCP connection established %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest));
pehrhovey	0:a548a085de55	637	#if LWIP_CALLBACK_API
pehrhovey	0:a548a085de55	638	LWIP_ASSERT("pcb->accept != NULL", pcb->accept != NULL);
pehrhovey	0:a548a085de55	639	#endif
pehrhovey	0:a548a085de55	640	/* Call the accept function. */
pehrhovey	0:a548a085de55	641	TCP_EVENT_ACCEPT(pcb, ERR_OK, err);
pehrhovey	0:a548a085de55	642	if (err != ERR_OK) {
pehrhovey	0:a548a085de55	643	/* If the accept function returns with an error, we abort
pehrhovey	0:a548a085de55	644	* the connection. */
pehrhovey	0:a548a085de55	645	tcp_abort(pcb);
pehrhovey	0:a548a085de55	646	return ERR_ABRT;
pehrhovey	0:a548a085de55	647	}
pehrhovey	0:a548a085de55	648	old_cwnd = pcb->cwnd;
pehrhovey	0:a548a085de55	649	/* If there was any data contained within this ACK,
pehrhovey	0:a548a085de55	650	* we'd better pass it on to the application as well. */
pehrhovey	0:a548a085de55	651	tcp_receive(pcb);
pehrhovey	0:a548a085de55	652
pehrhovey	0:a548a085de55	653	/* Prevent ACK for SYN to generate a sent event */
pehrhovey	0:a548a085de55	654	if (pcb->acked != 0) {
pehrhovey	0:a548a085de55	655	pcb->acked--;
pehrhovey	0:a548a085de55	656	}
pehrhovey	0:a548a085de55	657
pehrhovey	0:a548a085de55	658	pcb->cwnd = ((old_cwnd == 1) ? (pcb->mss * 2) : pcb->mss);
pehrhovey	0:a548a085de55	659
pehrhovey	0:a548a085de55	660	if (recv_flags & TF_GOT_FIN) {
pehrhovey	0:a548a085de55	661	tcp_ack_now(pcb);
pehrhovey	0:a548a085de55	662	pcb->state = CLOSE_WAIT;
pehrhovey	0:a548a085de55	663	}
pehrhovey	0:a548a085de55	664	}
pehrhovey	0:a548a085de55	665	/* incorrect ACK number */
pehrhovey	0:a548a085de55	666	else {
pehrhovey	0:a548a085de55	667	/* send RST */
pehrhovey	0:a548a085de55	668	tcp_rst(ackno, seqno + tcplen, &(iphdr->dest), &(iphdr->src),
pehrhovey	0:a548a085de55	669	tcphdr->dest, tcphdr->src);
pehrhovey	0:a548a085de55	670	}
pehrhovey	0:a548a085de55	671	} else if ((flags & TCP_SYN) && (seqno == pcb->rcv_nxt - 1)) {
pehrhovey	0:a548a085de55	672	/* Looks like another copy of the SYN - retransmit our SYN-ACK */
pehrhovey	0:a548a085de55	673	tcp_rexmit(pcb);
pehrhovey	0:a548a085de55	674	}
pehrhovey	0:a548a085de55	675	break;
pehrhovey	0:a548a085de55	676	case CLOSE_WAIT:
pehrhovey	0:a548a085de55	677	/* FALLTHROUGH */
pehrhovey	0:a548a085de55	678	case ESTABLISHED:
pehrhovey	0:a548a085de55	679	tcp_receive(pcb);
pehrhovey	0:a548a085de55	680	if (recv_flags & TF_GOT_FIN) { /* passive close */
pehrhovey	0:a548a085de55	681	tcp_ack_now(pcb);
pehrhovey	0:a548a085de55	682	pcb->state = CLOSE_WAIT;
pehrhovey	0:a548a085de55	683	}
pehrhovey	0:a548a085de55	684	break;
pehrhovey	0:a548a085de55	685	case FIN_WAIT_1:
pehrhovey	0:a548a085de55	686	tcp_receive(pcb);
pehrhovey	0:a548a085de55	687	if (recv_flags & TF_GOT_FIN) {
pehrhovey	0:a548a085de55	688	if ((flags & TCP_ACK) && (ackno == pcb->snd_nxt)) {
pehrhovey	0:a548a085de55	689	LWIP_DEBUGF(TCP_DEBUG,
pehrhovey	0:a548a085de55	690	("TCP connection closed %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest));
pehrhovey	0:a548a085de55	691	tcp_ack_now(pcb);
pehrhovey	0:a548a085de55	692	tcp_pcb_purge(pcb);
pehrhovey	0:a548a085de55	693	TCP_RMV(&tcp_active_pcbs, pcb);
pehrhovey	0:a548a085de55	694	pcb->state = TIME_WAIT;
pehrhovey	0:a548a085de55	695	TCP_REG(&tcp_tw_pcbs, pcb);
pehrhovey	0:a548a085de55	696	} else {
pehrhovey	0:a548a085de55	697	tcp_ack_now(pcb);
pehrhovey	0:a548a085de55	698	pcb->state = CLOSING;
pehrhovey	0:a548a085de55	699	}
pehrhovey	0:a548a085de55	700	} else if ((flags & TCP_ACK) && (ackno == pcb->snd_nxt)) {
pehrhovey	0:a548a085de55	701	pcb->state = FIN_WAIT_2;
pehrhovey	0:a548a085de55	702	}
pehrhovey	0:a548a085de55	703	break;
pehrhovey	0:a548a085de55	704	case FIN_WAIT_2:
pehrhovey	0:a548a085de55	705	tcp_receive(pcb);
pehrhovey	0:a548a085de55	706	if (recv_flags & TF_GOT_FIN) {
pehrhovey	0:a548a085de55	707	LWIP_DEBUGF(TCP_DEBUG, ("TCP connection closed %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest));
pehrhovey	0:a548a085de55	708	tcp_ack_now(pcb);
pehrhovey	0:a548a085de55	709	tcp_pcb_purge(pcb);
pehrhovey	0:a548a085de55	710	TCP_RMV(&tcp_active_pcbs, pcb);
pehrhovey	0:a548a085de55	711	pcb->state = TIME_WAIT;
pehrhovey	0:a548a085de55	712	TCP_REG(&tcp_tw_pcbs, pcb);
pehrhovey	0:a548a085de55	713	}
pehrhovey	0:a548a085de55	714	break;
pehrhovey	0:a548a085de55	715	case CLOSING:
pehrhovey	0:a548a085de55	716	tcp_receive(pcb);
pehrhovey	0:a548a085de55	717	if (flags & TCP_ACK && ackno == pcb->snd_nxt) {
pehrhovey	0:a548a085de55	718	LWIP_DEBUGF(TCP_DEBUG, ("TCP connection closed %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest));
pehrhovey	0:a548a085de55	719	tcp_pcb_purge(pcb);
pehrhovey	0:a548a085de55	720	TCP_RMV(&tcp_active_pcbs, pcb);
pehrhovey	0:a548a085de55	721	pcb->state = TIME_WAIT;
pehrhovey	0:a548a085de55	722	TCP_REG(&tcp_tw_pcbs, pcb);
pehrhovey	0:a548a085de55	723	}
pehrhovey	0:a548a085de55	724	break;
pehrhovey	0:a548a085de55	725	case LAST_ACK:
pehrhovey	0:a548a085de55	726	tcp_receive(pcb);
pehrhovey	0:a548a085de55	727	if (flags & TCP_ACK && ackno == pcb->snd_nxt) {
pehrhovey	0:a548a085de55	728	LWIP_DEBUGF(TCP_DEBUG, ("TCP connection closed %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest));
pehrhovey	0:a548a085de55	729	/* bugfix #21699: don't set pcb->state to CLOSED here or we risk leaking segments */
pehrhovey	0:a548a085de55	730	recv_flags \|= TF_CLOSED;
pehrhovey	0:a548a085de55	731	}
pehrhovey	0:a548a085de55	732	break;
pehrhovey	0:a548a085de55	733	default:
pehrhovey	0:a548a085de55	734	break;
pehrhovey	0:a548a085de55	735	}
pehrhovey	0:a548a085de55	736	return ERR_OK;
pehrhovey	0:a548a085de55	737	}
pehrhovey	0:a548a085de55	738
pehrhovey	0:a548a085de55	739	/**
pehrhovey	0:a548a085de55	740	* Called by tcp_process. Checks if the given segment is an ACK for outstanding
pehrhovey	0:a548a085de55	741	* data, and if so frees the memory of the buffered data. Next, is places the
pehrhovey	0:a548a085de55	742	* segment on any of the receive queues (pcb->recved or pcb->ooseq). If the segment
pehrhovey	0:a548a085de55	743	* is buffered, the pbuf is referenced by pbuf_ref so that it will not be freed until
pehrhovey	0:a548a085de55	744	* i it has been removed from the buffer.
pehrhovey	0:a548a085de55	745	*
pehrhovey	0:a548a085de55	746	* If the incoming segment constitutes an ACK for a segment that was used for RTT
pehrhovey	0:a548a085de55	747	* estimation, the RTT is estimated here as well.
pehrhovey	0:a548a085de55	748	*
pehrhovey	0:a548a085de55	749	* Called from tcp_process().
pehrhovey	0:a548a085de55	750	*
pehrhovey	0:a548a085de55	751	* @return 1 if the incoming segment is the next in sequence, 0 if not
pehrhovey	0:a548a085de55	752	*/
pehrhovey	0:a548a085de55	753	static u8_t
pehrhovey	0:a548a085de55	754	tcp_receive(struct tcp_pcb *pcb)
pehrhovey	0:a548a085de55	755	{
pehrhovey	0:a548a085de55	756	struct tcp_seg *next;
pehrhovey	0:a548a085de55	757	#if TCP_QUEUE_OOSEQ
pehrhovey	0:a548a085de55	758	struct tcp_seg prev, cseg;
pehrhovey	0:a548a085de55	759	#endif
pehrhovey	0:a548a085de55	760	struct pbuf *p;
pehrhovey	0:a548a085de55	761	s32_t off;
pehrhovey	0:a548a085de55	762	s16_t m;
pehrhovey	0:a548a085de55	763	u32_t right_wnd_edge;
pehrhovey	0:a548a085de55	764	u16_t new_tot_len;
pehrhovey	0:a548a085de55	765	u8_t accepted_inseq = 0;
pehrhovey	0:a548a085de55	766	int found_dupack = 0;
pehrhovey	0:a548a085de55	767
pehrhovey	0:a548a085de55	768	if (flags & TCP_ACK) {
pehrhovey	0:a548a085de55	769	right_wnd_edge = pcb->snd_wnd + pcb->snd_wl2;
pehrhovey	0:a548a085de55	770
pehrhovey	0:a548a085de55	771	/* Update window. */
pehrhovey	0:a548a085de55	772	if (TCP_SEQ_LT(pcb->snd_wl1, seqno) \|\|
pehrhovey	0:a548a085de55	773	(pcb->snd_wl1 == seqno && TCP_SEQ_LT(pcb->snd_wl2, ackno)) \|\|
pehrhovey	0:a548a085de55	774	(pcb->snd_wl2 == ackno && tcphdr->wnd > pcb->snd_wnd)) {
pehrhovey	0:a548a085de55	775	pcb->snd_wnd = tcphdr->wnd;
pehrhovey	0:a548a085de55	776	pcb->snd_wl1 = seqno;
pehrhovey	0:a548a085de55	777	pcb->snd_wl2 = ackno;
pehrhovey	0:a548a085de55	778	if (pcb->snd_wnd > 0 && pcb->persist_backoff > 0) {
pehrhovey	0:a548a085de55	779	pcb->persist_backoff = 0;
pehrhovey	0:a548a085de55	780	}
pehrhovey	0:a548a085de55	781	LWIP_DEBUGF(TCP_WND_DEBUG, ("tcp_receive: window update %"U16_F"\n", pcb->snd_wnd));
pehrhovey	0:a548a085de55	782	#if TCP_WND_DEBUG
pehrhovey	0:a548a085de55	783	} else {
pehrhovey	0:a548a085de55	784	if (pcb->snd_wnd != tcphdr->wnd) {
pehrhovey	0:a548a085de55	785	LWIP_DEBUGF(TCP_WND_DEBUG,
pehrhovey	0:a548a085de55	786	("tcp_receive: no window update lastack %"U32_F" ackno %"
pehrhovey	0:a548a085de55	787	U32_F" wl1 %"U32_F" seqno %"U32_F" wl2 %"U32_F"\n",
pehrhovey	0:a548a085de55	788	pcb->lastack, ackno, pcb->snd_wl1, seqno, pcb->snd_wl2));
pehrhovey	0:a548a085de55	789	}
pehrhovey	0:a548a085de55	790	#endif /* TCP_WND_DEBUG */
pehrhovey	0:a548a085de55	791	}
pehrhovey	0:a548a085de55	792
pehrhovey	0:a548a085de55	793	/* (From Stevens TCP/IP Illustrated Vol II, p970.) Its only a
pehrhovey	0:a548a085de55	794	* duplicate ack if:
pehrhovey	0:a548a085de55	795	* 1) It doesn't ACK new data
pehrhovey	0:a548a085de55	796	* 2) length of received packet is zero (i.e. no payload)
pehrhovey	0:a548a085de55	797	* 3) the advertised window hasn't changed
pehrhovey	0:a548a085de55	798	* 4) There is outstanding unacknowledged data (retransmission timer running)
pehrhovey	0:a548a085de55	799	* 5) The ACK is == biggest ACK sequence number so far seen (snd_una)
pehrhovey	0:a548a085de55	800	*
pehrhovey	0:a548a085de55	801	* If it passes all five, should process as a dupack:
pehrhovey	0:a548a085de55	802	* a) dupacks < 3: do nothing
pehrhovey	0:a548a085de55	803	* b) dupacks == 3: fast retransmit
pehrhovey	0:a548a085de55	804	* c) dupacks > 3: increase cwnd
pehrhovey	0:a548a085de55	805	*
pehrhovey	0:a548a085de55	806	* If it only passes 1-3, should reset dupack counter (and add to
pehrhovey	0:a548a085de55	807	* stats, which we don't do in lwIP)
pehrhovey	0:a548a085de55	808	*
pehrhovey	0:a548a085de55	809	* If it only passes 1, should reset dupack counter
pehrhovey	0:a548a085de55	810	*
pehrhovey	0:a548a085de55	811	*/
pehrhovey	0:a548a085de55	812
pehrhovey	0:a548a085de55	813	/* Clause 1 */
pehrhovey	0:a548a085de55	814	if (TCP_SEQ_LEQ(ackno, pcb->lastack)) {
pehrhovey	0:a548a085de55	815	pcb->acked = 0;
pehrhovey	0:a548a085de55	816	/* Clause 2 */
pehrhovey	0:a548a085de55	817	if (tcplen == 0) {
pehrhovey	0:a548a085de55	818	/* Clause 3 */
pehrhovey	0:a548a085de55	819	if (pcb->snd_wl2 + pcb->snd_wnd == right_wnd_edge){
pehrhovey	0:a548a085de55	820	/* Clause 4 */
pehrhovey	0:a548a085de55	821	if (pcb->rtime >= 0) {
pehrhovey	0:a548a085de55	822	/* Clause 5 */
pehrhovey	0:a548a085de55	823	if (pcb->lastack == ackno) {
pehrhovey	0:a548a085de55	824	found_dupack = 1;
pehrhovey	0:a548a085de55	825	if (pcb->dupacks + 1 > pcb->dupacks)
pehrhovey	0:a548a085de55	826	++pcb->dupacks;
pehrhovey	0:a548a085de55	827	if (pcb->dupacks > 3) {
pehrhovey	0:a548a085de55	828	/* Inflate the congestion window, but not if it means that
pehrhovey	0:a548a085de55	829	the value overflows. */
pehrhovey	0:a548a085de55	830	if ((u16_t)(pcb->cwnd + pcb->mss) > pcb->cwnd) {
pehrhovey	0:a548a085de55	831	pcb->cwnd += pcb->mss;
pehrhovey	0:a548a085de55	832	}
pehrhovey	0:a548a085de55	833	} else if (pcb->dupacks == 3) {
pehrhovey	0:a548a085de55	834	/* Do fast retransmit */
pehrhovey	0:a548a085de55	835	tcp_rexmit_fast(pcb);
pehrhovey	0:a548a085de55	836	}
pehrhovey	0:a548a085de55	837	}
pehrhovey	0:a548a085de55	838	}
pehrhovey	0:a548a085de55	839	}
pehrhovey	0:a548a085de55	840	}
pehrhovey	0:a548a085de55	841	/* If Clause (1) or more is true, but not a duplicate ack, reset
pehrhovey	0:a548a085de55	842	* count of consecutive duplicate acks */
pehrhovey	0:a548a085de55	843	if (!found_dupack) {
pehrhovey	0:a548a085de55	844	pcb->dupacks = 0;
pehrhovey	0:a548a085de55	845	}
pehrhovey	0:a548a085de55	846	} else if (TCP_SEQ_BETWEEN(ackno, pcb->lastack+1, pcb->snd_nxt)){
pehrhovey	0:a548a085de55	847	/* We come here when the ACK acknowledges new data. */
pehrhovey	0:a548a085de55	848
pehrhovey	0:a548a085de55	849	/* Reset the "IN Fast Retransmit" flag, since we are no longer
pehrhovey	0:a548a085de55	850	in fast retransmit. Also reset the congestion window to the
pehrhovey	0:a548a085de55	851	slow start threshold. */
pehrhovey	0:a548a085de55	852	if (pcb->flags & TF_INFR) {
pehrhovey	0:a548a085de55	853	pcb->flags &= ~TF_INFR;
pehrhovey	0:a548a085de55	854	pcb->cwnd = pcb->ssthresh;
pehrhovey	0:a548a085de55	855	}
pehrhovey	0:a548a085de55	856
pehrhovey	0:a548a085de55	857	/* Reset the number of retransmissions. */
pehrhovey	0:a548a085de55	858	pcb->nrtx = 0;
pehrhovey	0:a548a085de55	859
pehrhovey	0:a548a085de55	860	/* Reset the retransmission time-out. */
pehrhovey	0:a548a085de55	861	pcb->rto = (pcb->sa >> 3) + pcb->sv;
pehrhovey	0:a548a085de55	862
pehrhovey	0:a548a085de55	863	/* Update the send buffer space. Diff between the two can never exceed 64K? */
pehrhovey	0:a548a085de55	864	pcb->acked = (u16_t)(ackno - pcb->lastack);
pehrhovey	0:a548a085de55	865
pehrhovey	0:a548a085de55	866	pcb->snd_buf += pcb->acked;
pehrhovey	0:a548a085de55	867
pehrhovey	0:a548a085de55	868	/* Reset the fast retransmit variables. */
pehrhovey	0:a548a085de55	869	pcb->dupacks = 0;
pehrhovey	0:a548a085de55	870	pcb->lastack = ackno;
pehrhovey	0:a548a085de55	871
pehrhovey	0:a548a085de55	872	/* Update the congestion control variables (cwnd and
pehrhovey	0:a548a085de55	873	ssthresh). */
pehrhovey	0:a548a085de55	874	if (pcb->state >= ESTABLISHED) {
pehrhovey	0:a548a085de55	875	if (pcb->cwnd < pcb->ssthresh) {
pehrhovey	0:a548a085de55	876	if ((u16_t)(pcb->cwnd + pcb->mss) > pcb->cwnd) {
pehrhovey	0:a548a085de55	877	pcb->cwnd += pcb->mss;
pehrhovey	0:a548a085de55	878	}
pehrhovey	0:a548a085de55	879	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_receive: slow start cwnd %"U16_F"\n", pcb->cwnd));
pehrhovey	0:a548a085de55	880	} else {
pehrhovey	0:a548a085de55	881	u16_t new_cwnd = (pcb->cwnd + pcb->mss * pcb->mss / pcb->cwnd);
pehrhovey	0:a548a085de55	882	if (new_cwnd > pcb->cwnd) {
pehrhovey	0:a548a085de55	883	pcb->cwnd = new_cwnd;
pehrhovey	0:a548a085de55	884	}
pehrhovey	0:a548a085de55	885	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_receive: congestion avoidance cwnd %"U16_F"\n", pcb->cwnd));
pehrhovey	0:a548a085de55	886	}
pehrhovey	0:a548a085de55	887	}
pehrhovey	0:a548a085de55	888	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: ACK for %"U32_F", unacked->seqno %"U32_F":%"U32_F"\n",
pehrhovey	0:a548a085de55	889	ackno,
pehrhovey	0:a548a085de55	890	pcb->unacked != NULL?
pehrhovey	0:a548a085de55	891	ntohl(pcb->unacked->tcphdr->seqno): 0,
pehrhovey	0:a548a085de55	892	pcb->unacked != NULL?
pehrhovey	0:a548a085de55	893	ntohl(pcb->unacked->tcphdr->seqno) + TCP_TCPLEN(pcb->unacked): 0));
pehrhovey	0:a548a085de55	894
pehrhovey	0:a548a085de55	895	/* Remove segment from the unacknowledged list if the incoming
pehrhovey	0:a548a085de55	896	ACK acknowlegdes them. */
pehrhovey	0:a548a085de55	897	while (pcb->unacked != NULL &&
pehrhovey	0:a548a085de55	898	TCP_SEQ_LEQ(ntohl(pcb->unacked->tcphdr->seqno) +
pehrhovey	0:a548a085de55	899	TCP_TCPLEN(pcb->unacked), ackno)) {
pehrhovey	0:a548a085de55	900	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: removing %"U32_F":%"U32_F" from pcb->unacked\n",
pehrhovey	0:a548a085de55	901	ntohl(pcb->unacked->tcphdr->seqno),
pehrhovey	0:a548a085de55	902	ntohl(pcb->unacked->tcphdr->seqno) +
pehrhovey	0:a548a085de55	903	TCP_TCPLEN(pcb->unacked)));
pehrhovey	0:a548a085de55	904
pehrhovey	0:a548a085de55	905	next = pcb->unacked;
pehrhovey	0:a548a085de55	906	pcb->unacked = pcb->unacked->next;
pehrhovey	0:a548a085de55	907
pehrhovey	0:a548a085de55	908	LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_receive: queuelen %"U16_F" ... ", (u16_t)pcb->snd_queuelen));
pehrhovey	0:a548a085de55	909	LWIP_ASSERT("pcb->snd_queuelen >= pbuf_clen(next->p)", (pcb->snd_queuelen >= pbuf_clen(next->p)));
pehrhovey	0:a548a085de55	910	/* Prevent ACK for FIN to generate a sent event */
pehrhovey	0:a548a085de55	911	if ((pcb->acked != 0) && ((TCPH_FLAGS(next->tcphdr) & TCP_FIN) != 0)) {
pehrhovey	0:a548a085de55	912	pcb->acked--;
pehrhovey	0:a548a085de55	913	}
pehrhovey	0:a548a085de55	914
pehrhovey	0:a548a085de55	915	pcb->snd_queuelen -= pbuf_clen(next->p);
pehrhovey	0:a548a085de55	916	tcp_seg_free(next);
pehrhovey	0:a548a085de55	917
pehrhovey	0:a548a085de55	918	LWIP_DEBUGF(TCP_QLEN_DEBUG, ("%"U16_F" (after freeing unacked)\n", (u16_t)pcb->snd_queuelen));
pehrhovey	0:a548a085de55	919	if (pcb->snd_queuelen != 0) {
pehrhovey	0:a548a085de55	920	LWIP_ASSERT("tcp_receive: valid queue length", pcb->unacked != NULL \|\|
pehrhovey	0:a548a085de55	921	pcb->unsent != NULL);
pehrhovey	0:a548a085de55	922	}
pehrhovey	0:a548a085de55	923	}
pehrhovey	0:a548a085de55	924
pehrhovey	0:a548a085de55	925	/* If there's nothing left to acknowledge, stop the retransmit
pehrhovey	0:a548a085de55	926	timer, otherwise reset it to start again */
pehrhovey	0:a548a085de55	927	if(pcb->unacked == NULL)
pehrhovey	0:a548a085de55	928	pcb->rtime = -1;
pehrhovey	0:a548a085de55	929	else
pehrhovey	0:a548a085de55	930	pcb->rtime = 0;
pehrhovey	0:a548a085de55	931
pehrhovey	0:a548a085de55	932	pcb->polltmr = 0;
pehrhovey	0:a548a085de55	933	} else {
pehrhovey	0:a548a085de55	934	/* Fix bug bug #21582: out of sequence ACK, didn't really ack anything */
pehrhovey	0:a548a085de55	935	pcb->acked = 0;
pehrhovey	0:a548a085de55	936	}
pehrhovey	0:a548a085de55	937
pehrhovey	0:a548a085de55	938	/* We go through the ->unsent list to see if any of the segments
pehrhovey	0:a548a085de55	939	on the list are acknowledged by the ACK. This may seem
pehrhovey	0:a548a085de55	940	strange since an "unsent" segment shouldn't be acked. The
pehrhovey	0:a548a085de55	941	rationale is that lwIP puts all outstanding segments on the
pehrhovey	0:a548a085de55	942	->unsent list after a retransmission, so these segments may
pehrhovey	0:a548a085de55	943	in fact have been sent once. */
pehrhovey	0:a548a085de55	944	while (pcb->unsent != NULL &&
pehrhovey	0:a548a085de55	945	TCP_SEQ_BETWEEN(ackno, ntohl(pcb->unsent->tcphdr->seqno) +
pehrhovey	0:a548a085de55	946	TCP_TCPLEN(pcb->unsent), pcb->snd_nxt)) {
pehrhovey	0:a548a085de55	947	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: removing %"U32_F":%"U32_F" from pcb->unsent\n",
pehrhovey	0:a548a085de55	948	ntohl(pcb->unsent->tcphdr->seqno), ntohl(pcb->unsent->tcphdr->seqno) +
pehrhovey	0:a548a085de55	949	TCP_TCPLEN(pcb->unsent)));
pehrhovey	0:a548a085de55	950
pehrhovey	0:a548a085de55	951	next = pcb->unsent;
pehrhovey	0:a548a085de55	952	pcb->unsent = pcb->unsent->next;
pehrhovey	0:a548a085de55	953	LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_receive: queuelen %"U16_F" ... ", (u16_t)pcb->snd_queuelen));
pehrhovey	0:a548a085de55	954	LWIP_ASSERT("pcb->snd_queuelen >= pbuf_clen(next->p)", (pcb->snd_queuelen >= pbuf_clen(next->p)));
pehrhovey	0:a548a085de55	955	/* Prevent ACK for FIN to generate a sent event */
pehrhovey	0:a548a085de55	956	if ((pcb->acked != 0) && ((TCPH_FLAGS(next->tcphdr) & TCP_FIN) != 0)) {
pehrhovey	0:a548a085de55	957	pcb->acked--;
pehrhovey	0:a548a085de55	958	}
pehrhovey	0:a548a085de55	959	pcb->snd_queuelen -= pbuf_clen(next->p);
pehrhovey	0:a548a085de55	960	tcp_seg_free(next);
pehrhovey	0:a548a085de55	961	LWIP_DEBUGF(TCP_QLEN_DEBUG, ("%"U16_F" (after freeing unsent)\n", (u16_t)pcb->snd_queuelen));
pehrhovey	0:a548a085de55	962	if (pcb->snd_queuelen != 0) {
pehrhovey	0:a548a085de55	963	LWIP_ASSERT("tcp_receive: valid queue length",
pehrhovey	0:a548a085de55	964	pcb->unacked != NULL \|\| pcb->unsent != NULL);
pehrhovey	0:a548a085de55	965	}
pehrhovey	0:a548a085de55	966	}
pehrhovey	0:a548a085de55	967	/* End of ACK for new data processing. */
pehrhovey	0:a548a085de55	968
pehrhovey	0:a548a085de55	969	LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_receive: pcb->rttest %"U32_F" rtseq %"U32_F" ackno %"U32_F"\n",
pehrhovey	0:a548a085de55	970	pcb->rttest, pcb->rtseq, ackno));
pehrhovey	0:a548a085de55	971
pehrhovey	0:a548a085de55	972	/* RTT estimation calculations. This is done by checking if the
pehrhovey	0:a548a085de55	973	incoming segment acknowledges the segment we use to take a
pehrhovey	0:a548a085de55	974	round-trip time measurement. */
pehrhovey	0:a548a085de55	975	if (pcb->rttest && TCP_SEQ_LT(pcb->rtseq, ackno)) {
pehrhovey	0:a548a085de55	976	/* diff between this shouldn't exceed 32K since this are tcp timer ticks
pehrhovey	0:a548a085de55	977	and a round-trip shouldn't be that long... */
pehrhovey	0:a548a085de55	978	m = (s16_t)(tcp_ticks - pcb->rttest);
pehrhovey	0:a548a085de55	979
pehrhovey	0:a548a085de55	980	LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_receive: experienced rtt %"U16_F" ticks (%"U16_F" msec).\n",
pehrhovey	0:a548a085de55	981	m, m * TCP_SLOW_INTERVAL));
pehrhovey	0:a548a085de55	982
pehrhovey	0:a548a085de55	983	/* This is taken directly from VJs original code in his paper */
pehrhovey	0:a548a085de55	984	m = m - (pcb->sa >> 3);
pehrhovey	0:a548a085de55	985	pcb->sa += m;
pehrhovey	0:a548a085de55	986	if (m < 0) {
pehrhovey	0:a548a085de55	987	m = -m;
pehrhovey	0:a548a085de55	988	}
pehrhovey	0:a548a085de55	989	m = m - (pcb->sv >> 2);
pehrhovey	0:a548a085de55	990	pcb->sv += m;
pehrhovey	0:a548a085de55	991	pcb->rto = (pcb->sa >> 3) + pcb->sv;
pehrhovey	0:a548a085de55	992
pehrhovey	0:a548a085de55	993	LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_receive: RTO %"U16_F" (%"U16_F" milliseconds)\n",
pehrhovey	0:a548a085de55	994	pcb->rto, pcb->rto * TCP_SLOW_INTERVAL));
pehrhovey	0:a548a085de55	995
pehrhovey	0:a548a085de55	996	pcb->rttest = 0;
pehrhovey	0:a548a085de55	997	}
pehrhovey	0:a548a085de55	998	}
pehrhovey	0:a548a085de55	999
pehrhovey	0:a548a085de55	1000	/* If the incoming segment contains data, we must process it
pehrhovey	0:a548a085de55	1001	further. */
pehrhovey	0:a548a085de55	1002	if (tcplen > 0) {
pehrhovey	0:a548a085de55	1003	/* This code basically does three things:
pehrhovey	0:a548a085de55	1004
pehrhovey	0:a548a085de55	1005	+) If the incoming segment contains data that is the next
pehrhovey	0:a548a085de55	1006	in-sequence data, this data is passed to the application. This
pehrhovey	0:a548a085de55	1007	might involve trimming the first edge of the data. The rcv_nxt
pehrhovey	0:a548a085de55	1008	variable and the advertised window are adjusted.
pehrhovey	0:a548a085de55	1009
pehrhovey	0:a548a085de55	1010	+) If the incoming segment has data that is above the next
pehrhovey	0:a548a085de55	1011	sequence number expected (->rcv_nxt), the segment is placed on
pehrhovey	0:a548a085de55	1012	the ->ooseq queue. This is done by finding the appropriate
pehrhovey	0:a548a085de55	1013	place in the ->ooseq queue (which is ordered by sequence
pehrhovey	0:a548a085de55	1014	number) and trim the segment in both ends if needed. An
pehrhovey	0:a548a085de55	1015	immediate ACK is sent to indicate that we received an
pehrhovey	0:a548a085de55	1016	out-of-sequence segment.
pehrhovey	0:a548a085de55	1017
pehrhovey	0:a548a085de55	1018	+) Finally, we check if the first segment on the ->ooseq queue
pehrhovey	0:a548a085de55	1019	now is in sequence (i.e., if rcv_nxt >= ooseq->seqno). If
pehrhovey	0:a548a085de55	1020	rcv_nxt > ooseq->seqno, we must trim the first edge of the
pehrhovey	0:a548a085de55	1021	segment on ->ooseq before we adjust rcv_nxt. The data in the
pehrhovey	0:a548a085de55	1022	segments that are now on sequence are chained onto the
pehrhovey	0:a548a085de55	1023	incoming segment so that we only need to call the application
pehrhovey	0:a548a085de55	1024	once.
pehrhovey	0:a548a085de55	1025	*/
pehrhovey	0:a548a085de55	1026
pehrhovey	0:a548a085de55	1027	/* First, we check if we must trim the first edge. We have to do
pehrhovey	0:a548a085de55	1028	this if the sequence number of the incoming segment is less
pehrhovey	0:a548a085de55	1029	than rcv_nxt, and the sequence number plus the length of the
pehrhovey	0:a548a085de55	1030	segment is larger than rcv_nxt. */
pehrhovey	0:a548a085de55	1031	/* if (TCP_SEQ_LT(seqno, pcb->rcv_nxt)){
pehrhovey	0:a548a085de55	1032	if (TCP_SEQ_LT(pcb->rcv_nxt, seqno + tcplen)) {*/
pehrhovey	0:a548a085de55	1033	if (TCP_SEQ_BETWEEN(pcb->rcv_nxt, seqno + 1, seqno + tcplen - 1)){
pehrhovey	0:a548a085de55	1034	/* Trimming the first edge is done by pushing the payload
pehrhovey	0:a548a085de55	1035	pointer in the pbuf downwards. This is somewhat tricky since
pehrhovey	0:a548a085de55	1036	we do not want to discard the full contents of the pbuf up to
pehrhovey	0:a548a085de55	1037	the new starting point of the data since we have to keep the
pehrhovey	0:a548a085de55	1038	TCP header which is present in the first pbuf in the chain.
pehrhovey	0:a548a085de55	1039
pehrhovey	0:a548a085de55	1040	What is done is really quite a nasty hack: the first pbuf in
pehrhovey	0:a548a085de55	1041	the pbuf chain is pointed to by inseg.p. Since we need to be
pehrhovey	0:a548a085de55	1042	able to deallocate the whole pbuf, we cannot change this
pehrhovey	0:a548a085de55	1043	inseg.p pointer to point to any of the later pbufs in the
pehrhovey	0:a548a085de55	1044	chain. Instead, we point the ->payload pointer in the first
pehrhovey	0:a548a085de55	1045	pbuf to data in one of the later pbufs. We also set the
pehrhovey	0:a548a085de55	1046	inseg.data pointer to point to the right place. This way, the
pehrhovey	0:a548a085de55	1047	->p pointer will still point to the first pbuf, but the
pehrhovey	0:a548a085de55	1048	->p->payload pointer will point to data in another pbuf.
pehrhovey	0:a548a085de55	1049
pehrhovey	0:a548a085de55	1050	After we are done with adjusting the pbuf pointers we must
pehrhovey	0:a548a085de55	1051	adjust the ->data pointer in the seg and the segment
pehrhovey	0:a548a085de55	1052	length.*/
pehrhovey	0:a548a085de55	1053
pehrhovey	0:a548a085de55	1054	off = pcb->rcv_nxt - seqno;
pehrhovey	0:a548a085de55	1055	p = inseg.p;
pehrhovey	0:a548a085de55	1056	LWIP_ASSERT("inseg.p != NULL", inseg.p);
pehrhovey	0:a548a085de55	1057	LWIP_ASSERT("insane offset!", (off < 0x7fff));
pehrhovey	0:a548a085de55	1058	if (inseg.p->len < off) {
pehrhovey	0:a548a085de55	1059	LWIP_ASSERT("pbuf too short!", (((s32_t)inseg.p->tot_len) >= off));
pehrhovey	0:a548a085de55	1060	new_tot_len = (u16_t)(inseg.p->tot_len - off);
pehrhovey	0:a548a085de55	1061	while (p->len < off) {
pehrhovey	0:a548a085de55	1062	off -= p->len;
pehrhovey	0:a548a085de55	1063	/* KJM following line changed (with addition of new_tot_len var)
pehrhovey	0:a548a085de55	1064	to fix bug #9076
pehrhovey	0:a548a085de55	1065	inseg.p->tot_len -= p->len; */
pehrhovey	0:a548a085de55	1066	p->tot_len = new_tot_len;
pehrhovey	0:a548a085de55	1067	p->len = 0;
pehrhovey	0:a548a085de55	1068	p = p->next;
pehrhovey	0:a548a085de55	1069	}
pehrhovey	0:a548a085de55	1070	if(pbuf_header(p, (s16_t)-off)) {
pehrhovey	0:a548a085de55	1071	/* Do we need to cope with this failing? Assert for now */
pehrhovey	0:a548a085de55	1072	LWIP_ASSERT("pbuf_header failed", 0);
pehrhovey	0:a548a085de55	1073	}
pehrhovey	0:a548a085de55	1074	} else {
pehrhovey	0:a548a085de55	1075	if(pbuf_header(inseg.p, (s16_t)-off)) {
pehrhovey	0:a548a085de55	1076	/* Do we need to cope with this failing? Assert for now */
pehrhovey	0:a548a085de55	1077	LWIP_ASSERT("pbuf_header failed", 0);
pehrhovey	0:a548a085de55	1078	}
pehrhovey	0:a548a085de55	1079	}
pehrhovey	0:a548a085de55	1080	/* KJM following line changed to use p->payload rather than inseg->p->payload
pehrhovey	0:a548a085de55	1081	to fix bug #9076 */
pehrhovey	0:a548a085de55	1082	inseg.dataptr = p->payload;
pehrhovey	0:a548a085de55	1083	inseg.len -= (u16_t)(pcb->rcv_nxt - seqno);
pehrhovey	0:a548a085de55	1084	inseg.tcphdr->seqno = seqno = pcb->rcv_nxt;
pehrhovey	0:a548a085de55	1085	}
pehrhovey	0:a548a085de55	1086	else {
pehrhovey	0:a548a085de55	1087	if (TCP_SEQ_LT(seqno, pcb->rcv_nxt)){
pehrhovey	0:a548a085de55	1088	/* the whole segment is < rcv_nxt */
pehrhovey	0:a548a085de55	1089	/* must be a duplicate of a packet that has already been correctly handled */
pehrhovey	0:a548a085de55	1090
pehrhovey	0:a548a085de55	1091	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: duplicate seqno %"U32_F"\n", seqno));
pehrhovey	0:a548a085de55	1092	tcp_ack_now(pcb);
pehrhovey	0:a548a085de55	1093	}
pehrhovey	0:a548a085de55	1094	}
pehrhovey	0:a548a085de55	1095
pehrhovey	0:a548a085de55	1096	/* The sequence number must be within the window (above rcv_nxt
pehrhovey	0:a548a085de55	1097	and below rcv_nxt + rcv_wnd) in order to be further
pehrhovey	0:a548a085de55	1098	processed. */
pehrhovey	0:a548a085de55	1099	if (TCP_SEQ_BETWEEN(seqno, pcb->rcv_nxt,
pehrhovey	0:a548a085de55	1100	pcb->rcv_nxt + pcb->rcv_wnd - 1)){
pehrhovey	0:a548a085de55	1101	if (pcb->rcv_nxt == seqno) {
pehrhovey	0:a548a085de55	1102	accepted_inseq = 1;
pehrhovey	0:a548a085de55	1103	/* The incoming segment is the next in sequence. We check if
pehrhovey	0:a548a085de55	1104	we have to trim the end of the segment and update rcv_nxt
pehrhovey	0:a548a085de55	1105	and pass the data to the application. */
pehrhovey	0:a548a085de55	1106	tcplen = TCP_TCPLEN(&inseg);
pehrhovey	0:a548a085de55	1107
pehrhovey	0:a548a085de55	1108	if (tcplen > pcb->rcv_wnd) {
pehrhovey	0:a548a085de55	1109	LWIP_DEBUGF(TCP_INPUT_DEBUG,
pehrhovey	0:a548a085de55	1110	("tcp_receive: other end overran receive window"
pehrhovey	0:a548a085de55	1111	"seqno %"U32_F" len %"U32_F" right edge %"U32_F"\n",
pehrhovey	0:a548a085de55	1112	seqno, tcplen, pcb->rcv_nxt + pcb->rcv_wnd));
pehrhovey	0:a548a085de55	1113	if (TCPH_FLAGS(inseg.tcphdr) & TCP_FIN) {
pehrhovey	0:a548a085de55	1114	/* Must remove the FIN from the header as we're trimming
pehrhovey	0:a548a085de55	1115	* that byte of sequence-space from the packet */
pehrhovey	0:a548a085de55	1116	TCPH_FLAGS_SET(inseg.tcphdr, TCPH_FLAGS(inseg.tcphdr) &~ TCP_FIN);
pehrhovey	0:a548a085de55	1117	}
pehrhovey	0:a548a085de55	1118	/* Adjust length of segment to fit in the window. */
pehrhovey	0:a548a085de55	1119	inseg.len = pcb->rcv_wnd;
pehrhovey	0:a548a085de55	1120	if (TCPH_FLAGS(inseg.tcphdr) & TCP_SYN) {
pehrhovey	0:a548a085de55	1121	inseg.len -= 1;
pehrhovey	0:a548a085de55	1122	}
pehrhovey	0:a548a085de55	1123	pbuf_realloc(inseg.p, inseg.len);
pehrhovey	0:a548a085de55	1124	tcplen = TCP_TCPLEN(&inseg);
pehrhovey	0:a548a085de55	1125	LWIP_ASSERT("tcp_receive: segment not trimmed correctly to rcv_wnd\n",
pehrhovey	0:a548a085de55	1126	(seqno + tcplen) == (pcb->rcv_nxt + pcb->rcv_wnd));
pehrhovey	0:a548a085de55	1127	}
pehrhovey	0:a548a085de55	1128	#if TCP_QUEUE_OOSEQ
pehrhovey	0:a548a085de55	1129	if (pcb->ooseq != NULL) {
pehrhovey	0:a548a085de55	1130	if (TCPH_FLAGS(inseg.tcphdr) & TCP_FIN) {
pehrhovey	0:a548a085de55	1131	LWIP_DEBUGF(TCP_INPUT_DEBUG,
pehrhovey	0:a548a085de55	1132	("tcp_receive: received in-order FIN, binning ooseq queue\n"));
pehrhovey	0:a548a085de55	1133	/* Received in-order FIN means anything that was received
pehrhovey	0:a548a085de55	1134	* out of order must now have been received in-order, so
pehrhovey	0:a548a085de55	1135	* bin the ooseq queue */
pehrhovey	0:a548a085de55	1136	while (pcb->ooseq != NULL) {
pehrhovey	0:a548a085de55	1137	struct tcp_seg *old_ooseq = pcb->ooseq;
pehrhovey	0:a548a085de55	1138	pcb->ooseq = pcb->ooseq->next;
pehrhovey	0:a548a085de55	1139	memp_free(MEMP_TCP_SEG, old_ooseq);
pehrhovey	0:a548a085de55	1140	}
pehrhovey	0:a548a085de55	1141	} else if (TCP_SEQ_LEQ(pcb->ooseq->tcphdr->seqno, seqno + tcplen)) {
pehrhovey	0:a548a085de55	1142	if (pcb->ooseq->len > 0) {
pehrhovey	0:a548a085de55	1143	/* We have to trim the second edge of the incoming segment. */
pehrhovey	0:a548a085de55	1144	LWIP_ASSERT("tcp_receive: trimmed segment would have zero length\n",
pehrhovey	0:a548a085de55	1145	TCP_SEQ_GT(pcb->ooseq->tcphdr->seqno, seqno));
pehrhovey	0:a548a085de55	1146	/* FIN in inseg already handled by dropping whole ooseq queue */
pehrhovey	0:a548a085de55	1147	inseg.len = (u16_t)(pcb->ooseq->tcphdr->seqno - seqno);
pehrhovey	0:a548a085de55	1148	if (TCPH_FLAGS(inseg.tcphdr) & TCP_SYN) {
pehrhovey	0:a548a085de55	1149	inseg.len -= 1;
pehrhovey	0:a548a085de55	1150	}
pehrhovey	0:a548a085de55	1151	pbuf_realloc(inseg.p, inseg.len);
pehrhovey	0:a548a085de55	1152	tcplen = TCP_TCPLEN(&inseg);
pehrhovey	0:a548a085de55	1153	LWIP_ASSERT("tcp_receive: segment not trimmed correctly to ooseq queue\n",
pehrhovey	0:a548a085de55	1154	(seqno + tcplen) == pcb->ooseq->tcphdr->seqno);
pehrhovey	0:a548a085de55	1155	} else {
pehrhovey	0:a548a085de55	1156	/* does the ooseq segment contain only flags that are in inseg also? */
pehrhovey	0:a548a085de55	1157	if ((TCPH_FLAGS(inseg.tcphdr) & (TCP_FIN\|TCP_SYN)) ==
pehrhovey	0:a548a085de55	1158	(TCPH_FLAGS(pcb->ooseq->tcphdr) & (TCP_FIN\|TCP_SYN))) {
pehrhovey	0:a548a085de55	1159	struct tcp_seg *old_ooseq = pcb->ooseq;
pehrhovey	0:a548a085de55	1160	pcb->ooseq = pcb->ooseq->next;
pehrhovey	0:a548a085de55	1161	memp_free(MEMP_TCP_SEG, old_ooseq);
pehrhovey	0:a548a085de55	1162	}
pehrhovey	0:a548a085de55	1163	}
pehrhovey	0:a548a085de55	1164	}
pehrhovey	0:a548a085de55	1165	}
pehrhovey	0:a548a085de55	1166	#endif /* TCP_QUEUE_OOSEQ */
pehrhovey	0:a548a085de55	1167
pehrhovey	0:a548a085de55	1168	pcb->rcv_nxt = seqno + tcplen;
pehrhovey	0:a548a085de55	1169
pehrhovey	0:a548a085de55	1170	/* Update the receiver's (our) window. */
pehrhovey	0:a548a085de55	1171	LWIP_ASSERT("tcp_receive: tcplen > rcv_wnd\n", pcb->rcv_wnd >= tcplen);
pehrhovey	0:a548a085de55	1172	pcb->rcv_wnd -= tcplen;
pehrhovey	0:a548a085de55	1173
pehrhovey	0:a548a085de55	1174	tcp_update_rcv_ann_wnd(pcb);
pehrhovey	0:a548a085de55	1175
pehrhovey	0:a548a085de55	1176	/* If there is data in the segment, we make preparations to
pehrhovey	0:a548a085de55	1177	pass this up to the application. The ->recv_data variable
pehrhovey	0:a548a085de55	1178	is used for holding the pbuf that goes to the
pehrhovey	0:a548a085de55	1179	application. The code for reassembling out-of-sequence data
pehrhovey	0:a548a085de55	1180	chains its data on this pbuf as well.
pehrhovey	0:a548a085de55	1181
pehrhovey	0:a548a085de55	1182	If the segment was a FIN, we set the TF_GOT_FIN flag that will
pehrhovey	0:a548a085de55	1183	be used to indicate to the application that the remote side has
pehrhovey	0:a548a085de55	1184	closed its end of the connection. */
pehrhovey	0:a548a085de55	1185	if (inseg.p->tot_len > 0) {
pehrhovey	0:a548a085de55	1186	recv_data = inseg.p;
pehrhovey	0:a548a085de55	1187	/* Since this pbuf now is the responsibility of the
pehrhovey	0:a548a085de55	1188	application, we delete our reference to it so that we won't
pehrhovey	0:a548a085de55	1189	(mistakingly) deallocate it. */
pehrhovey	0:a548a085de55	1190	inseg.p = NULL;
pehrhovey	0:a548a085de55	1191	}
pehrhovey	0:a548a085de55	1192	if (TCPH_FLAGS(inseg.tcphdr) & TCP_FIN) {
pehrhovey	0:a548a085de55	1193	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: received FIN.\n"));
pehrhovey	0:a548a085de55	1194	recv_flags \|= TF_GOT_FIN;
pehrhovey	0:a548a085de55	1195	}
pehrhovey	0:a548a085de55	1196
pehrhovey	0:a548a085de55	1197	#if TCP_QUEUE_OOSEQ
pehrhovey	0:a548a085de55	1198	/* We now check if we have segments on the ->ooseq queue that
pehrhovey	0:a548a085de55	1199	is now in sequence. */
pehrhovey	0:a548a085de55	1200	while (pcb->ooseq != NULL &&
pehrhovey	0:a548a085de55	1201	pcb->ooseq->tcphdr->seqno == pcb->rcv_nxt) {
pehrhovey	0:a548a085de55	1202
pehrhovey	0:a548a085de55	1203	cseg = pcb->ooseq;
pehrhovey	0:a548a085de55	1204	seqno = pcb->ooseq->tcphdr->seqno;
pehrhovey	0:a548a085de55	1205
pehrhovey	0:a548a085de55	1206	pcb->rcv_nxt += TCP_TCPLEN(cseg);
pehrhovey	0:a548a085de55	1207	LWIP_ASSERT("tcp_receive: ooseq tcplen > rcv_wnd\n",
pehrhovey	0:a548a085de55	1208	pcb->rcv_wnd >= TCP_TCPLEN(cseg));
pehrhovey	0:a548a085de55	1209	pcb->rcv_wnd -= TCP_TCPLEN(cseg);
pehrhovey	0:a548a085de55	1210
pehrhovey	0:a548a085de55	1211	tcp_update_rcv_ann_wnd(pcb);
pehrhovey	0:a548a085de55	1212
pehrhovey	0:a548a085de55	1213	if (cseg->p->tot_len > 0) {
pehrhovey	0:a548a085de55	1214	/* Chain this pbuf onto the pbuf that we will pass to
pehrhovey	0:a548a085de55	1215	the application. */
pehrhovey	0:a548a085de55	1216	if (recv_data) {
pehrhovey	0:a548a085de55	1217	pbuf_cat(recv_data, cseg->p);
pehrhovey	0:a548a085de55	1218	} else {
pehrhovey	0:a548a085de55	1219	recv_data = cseg->p;
pehrhovey	0:a548a085de55	1220	}
pehrhovey	0:a548a085de55	1221	cseg->p = NULL;
pehrhovey	0:a548a085de55	1222	}
pehrhovey	0:a548a085de55	1223	if (TCPH_FLAGS(cseg->tcphdr) & TCP_FIN) {
pehrhovey	0:a548a085de55	1224	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: dequeued FIN.\n"));
pehrhovey	0:a548a085de55	1225	recv_flags \|= TF_GOT_FIN;
pehrhovey	0:a548a085de55	1226	if (pcb->state == ESTABLISHED) { /* force passive close or we can move to active close */
pehrhovey	0:a548a085de55	1227	pcb->state = CLOSE_WAIT;
pehrhovey	0:a548a085de55	1228	}
pehrhovey	0:a548a085de55	1229	}
pehrhovey	0:a548a085de55	1230
pehrhovey	0:a548a085de55	1231
pehrhovey	0:a548a085de55	1232	pcb->ooseq = cseg->next;
pehrhovey	0:a548a085de55	1233	tcp_seg_free(cseg);
pehrhovey	0:a548a085de55	1234	}
pehrhovey	0:a548a085de55	1235	#endif /* TCP_QUEUE_OOSEQ */
pehrhovey	0:a548a085de55	1236
pehrhovey	0:a548a085de55	1237
pehrhovey	0:a548a085de55	1238	/* Acknowledge the segment(s). */
pehrhovey	0:a548a085de55	1239	tcp_ack(pcb);
pehrhovey	0:a548a085de55	1240
pehrhovey	0:a548a085de55	1241	} else {
pehrhovey	0:a548a085de55	1242	/* We get here if the incoming segment is out-of-sequence. */
pehrhovey	0:a548a085de55	1243	tcp_ack_now(pcb);
pehrhovey	0:a548a085de55	1244	#if TCP_QUEUE_OOSEQ
pehrhovey	0:a548a085de55	1245	/* We queue the segment on the ->ooseq queue. */
pehrhovey	0:a548a085de55	1246	if (pcb->ooseq == NULL) {
pehrhovey	0:a548a085de55	1247	pcb->ooseq = tcp_seg_copy(&inseg);
pehrhovey	0:a548a085de55	1248	} else {
pehrhovey	0:a548a085de55	1249	/* If the queue is not empty, we walk through the queue and
pehrhovey	0:a548a085de55	1250	try to find a place where the sequence number of the
pehrhovey	0:a548a085de55	1251	incoming segment is between the sequence numbers of the
pehrhovey	0:a548a085de55	1252	previous and the next segment on the ->ooseq queue. That is
pehrhovey	0:a548a085de55	1253	the place where we put the incoming segment. If needed, we
pehrhovey	0:a548a085de55	1254	trim the second edges of the previous and the incoming
pehrhovey	0:a548a085de55	1255	segment so that it will fit into the sequence.
pehrhovey	0:a548a085de55	1256
pehrhovey	0:a548a085de55	1257	If the incoming segment has the same sequence number as a
pehrhovey	0:a548a085de55	1258	segment on the ->ooseq queue, we discard the segment that
pehrhovey	0:a548a085de55	1259	contains less data. */
pehrhovey	0:a548a085de55	1260
pehrhovey	0:a548a085de55	1261	prev = NULL;
pehrhovey	0:a548a085de55	1262	for(next = pcb->ooseq; next != NULL; next = next->next) {
pehrhovey	0:a548a085de55	1263	if (seqno == next->tcphdr->seqno) {
pehrhovey	0:a548a085de55	1264	/* The sequence number of the incoming segment is the
pehrhovey	0:a548a085de55	1265	same as the sequence number of the segment on
pehrhovey	0:a548a085de55	1266	->ooseq. We check the lengths to see which one to
pehrhovey	0:a548a085de55	1267	discard. */
pehrhovey	0:a548a085de55	1268	if (inseg.len > next->len) {
pehrhovey	0:a548a085de55	1269	/* The incoming segment is larger than the old
pehrhovey	0:a548a085de55	1270	segment. We replace the old segment with the new
pehrhovey	0:a548a085de55	1271	one. */
pehrhovey	0:a548a085de55	1272	cseg = tcp_seg_copy(&inseg);
pehrhovey	0:a548a085de55	1273	if (cseg != NULL) {
pehrhovey	0:a548a085de55	1274	cseg->next = next->next;
pehrhovey	0:a548a085de55	1275	if (prev != NULL) {
pehrhovey	0:a548a085de55	1276	prev->next = cseg;
pehrhovey	0:a548a085de55	1277	} else {
pehrhovey	0:a548a085de55	1278	pcb->ooseq = cseg;
pehrhovey	0:a548a085de55	1279	}
pehrhovey	0:a548a085de55	1280	tcp_seg_free(next);
pehrhovey	0:a548a085de55	1281	if (cseg->next != NULL) {
pehrhovey	0:a548a085de55	1282	next = cseg->next;
pehrhovey	0:a548a085de55	1283	if (TCP_SEQ_GT(seqno + cseg->len, next->tcphdr->seqno)) {
pehrhovey	0:a548a085de55	1284	/* We need to trim the incoming segment. */
pehrhovey	0:a548a085de55	1285	cseg->len = (u16_t)(next->tcphdr->seqno - seqno);
pehrhovey	0:a548a085de55	1286	pbuf_realloc(cseg->p, cseg->len);
pehrhovey	0:a548a085de55	1287	}
pehrhovey	0:a548a085de55	1288	}
pehrhovey	0:a548a085de55	1289	}
pehrhovey	0:a548a085de55	1290	break;
pehrhovey	0:a548a085de55	1291	} else {
pehrhovey	0:a548a085de55	1292	/* Either the lenghts are the same or the incoming
pehrhovey	0:a548a085de55	1293	segment was smaller than the old one; in either
pehrhovey	0:a548a085de55	1294	case, we ditch the incoming segment. */
pehrhovey	0:a548a085de55	1295	break;
pehrhovey	0:a548a085de55	1296	}
pehrhovey	0:a548a085de55	1297	} else {
pehrhovey	0:a548a085de55	1298	if (prev == NULL) {
pehrhovey	0:a548a085de55	1299	if (TCP_SEQ_LT(seqno, next->tcphdr->seqno)) {
pehrhovey	0:a548a085de55	1300	/* The sequence number of the incoming segment is lower
pehrhovey	0:a548a085de55	1301	than the sequence number of the first segment on the
pehrhovey	0:a548a085de55	1302	queue. We put the incoming segment first on the
pehrhovey	0:a548a085de55	1303	queue. */
pehrhovey	0:a548a085de55	1304
pehrhovey	0:a548a085de55	1305	if (TCP_SEQ_GT(seqno + inseg.len, next->tcphdr->seqno)) {
pehrhovey	0:a548a085de55	1306	/* We need to trim the incoming segment. */
pehrhovey	0:a548a085de55	1307	inseg.len = (u16_t)(next->tcphdr->seqno - seqno);
pehrhovey	0:a548a085de55	1308	pbuf_realloc(inseg.p, inseg.len);
pehrhovey	0:a548a085de55	1309	}
pehrhovey	0:a548a085de55	1310	cseg = tcp_seg_copy(&inseg);
pehrhovey	0:a548a085de55	1311	if (cseg != NULL) {
pehrhovey	0:a548a085de55	1312	cseg->next = next;
pehrhovey	0:a548a085de55	1313	pcb->ooseq = cseg;
pehrhovey	0:a548a085de55	1314	}
pehrhovey	0:a548a085de55	1315	break;
pehrhovey	0:a548a085de55	1316	}
pehrhovey	0:a548a085de55	1317	} else
pehrhovey	0:a548a085de55	1318	/*if (TCP_SEQ_LT(prev->tcphdr->seqno, seqno) &&
pehrhovey	0:a548a085de55	1319	TCP_SEQ_LT(seqno, next->tcphdr->seqno)) {*/
pehrhovey	0:a548a085de55	1320	if(TCP_SEQ_BETWEEN(seqno, prev->tcphdr->seqno+1, next->tcphdr->seqno-1)){
pehrhovey	0:a548a085de55	1321	/* The sequence number of the incoming segment is in
pehrhovey	0:a548a085de55	1322	between the sequence numbers of the previous and
pehrhovey	0:a548a085de55	1323	the next segment on ->ooseq. We trim and insert the
pehrhovey	0:a548a085de55	1324	incoming segment and trim the previous segment, if
pehrhovey	0:a548a085de55	1325	needed. */
pehrhovey	0:a548a085de55	1326	if (TCP_SEQ_GT(seqno + inseg.len, next->tcphdr->seqno)) {
pehrhovey	0:a548a085de55	1327	/* We need to trim the incoming segment. */
pehrhovey	0:a548a085de55	1328	inseg.len = (u16_t)(next->tcphdr->seqno - seqno);
pehrhovey	0:a548a085de55	1329	pbuf_realloc(inseg.p, inseg.len);
pehrhovey	0:a548a085de55	1330	}
pehrhovey	0:a548a085de55	1331
pehrhovey	0:a548a085de55	1332	cseg = tcp_seg_copy(&inseg);
pehrhovey	0:a548a085de55	1333	if (cseg != NULL) {
pehrhovey	0:a548a085de55	1334	cseg->next = next;
pehrhovey	0:a548a085de55	1335	prev->next = cseg;
pehrhovey	0:a548a085de55	1336	if (TCP_SEQ_GT(prev->tcphdr->seqno + prev->len, seqno)) {
pehrhovey	0:a548a085de55	1337	/* We need to trim the prev segment. */
pehrhovey	0:a548a085de55	1338	prev->len = (u16_t)(seqno - prev->tcphdr->seqno);
pehrhovey	0:a548a085de55	1339	pbuf_realloc(prev->p, prev->len);
pehrhovey	0:a548a085de55	1340	}
pehrhovey	0:a548a085de55	1341	}
pehrhovey	0:a548a085de55	1342	break;
pehrhovey	0:a548a085de55	1343	}
pehrhovey	0:a548a085de55	1344	/* If the "next" segment is the last segment on the
pehrhovey	0:a548a085de55	1345	ooseq queue, we add the incoming segment to the end
pehrhovey	0:a548a085de55	1346	of the list. */
pehrhovey	0:a548a085de55	1347	if (next->next == NULL &&
pehrhovey	0:a548a085de55	1348	TCP_SEQ_GT(seqno, next->tcphdr->seqno)) {
pehrhovey	0:a548a085de55	1349	next->next = tcp_seg_copy(&inseg);
pehrhovey	0:a548a085de55	1350	if (next->next != NULL) {
pehrhovey	0:a548a085de55	1351	if (TCP_SEQ_GT(next->tcphdr->seqno + next->len, seqno)) {
pehrhovey	0:a548a085de55	1352	/* We need to trim the last segment. */
pehrhovey	0:a548a085de55	1353	next->len = (u16_t)(seqno - next->tcphdr->seqno);
pehrhovey	0:a548a085de55	1354	pbuf_realloc(next->p, next->len);
pehrhovey	0:a548a085de55	1355	}
pehrhovey	0:a548a085de55	1356	}
pehrhovey	0:a548a085de55	1357	break;
pehrhovey	0:a548a085de55	1358	}
pehrhovey	0:a548a085de55	1359	}
pehrhovey	0:a548a085de55	1360	prev = next;
pehrhovey	0:a548a085de55	1361	}
pehrhovey	0:a548a085de55	1362	}
pehrhovey	0:a548a085de55	1363	#endif /* TCP_QUEUE_OOSEQ */
pehrhovey	0:a548a085de55	1364
pehrhovey	0:a548a085de55	1365	}
pehrhovey	0:a548a085de55	1366	} else {
pehrhovey	0:a548a085de55	1367	tcp_ack_now(pcb);
pehrhovey	0:a548a085de55	1368	}
pehrhovey	0:a548a085de55	1369	} else {
pehrhovey	0:a548a085de55	1370	/* Segments with length 0 is taken care of here. Segments that
pehrhovey	0:a548a085de55	1371	fall out of the window are ACKed. */
pehrhovey	0:a548a085de55	1372	/*if (TCP_SEQ_GT(pcb->rcv_nxt, seqno) \|\|
pehrhovey	0:a548a085de55	1373	TCP_SEQ_GEQ(seqno, pcb->rcv_nxt + pcb->rcv_wnd)) {*/
pehrhovey	0:a548a085de55	1374	if(!TCP_SEQ_BETWEEN(seqno, pcb->rcv_nxt, pcb->rcv_nxt + pcb->rcv_wnd-1)){
pehrhovey	0:a548a085de55	1375	tcp_ack_now(pcb);
pehrhovey	0:a548a085de55	1376	}
pehrhovey	0:a548a085de55	1377	}
pehrhovey	0:a548a085de55	1378	return accepted_inseq;
pehrhovey	0:a548a085de55	1379	}
pehrhovey	0:a548a085de55	1380
pehrhovey	0:a548a085de55	1381	/**
pehrhovey	0:a548a085de55	1382	* Parses the options contained in the incoming segment.
pehrhovey	0:a548a085de55	1383	*
pehrhovey	0:a548a085de55	1384	* Called from tcp_listen_input() and tcp_process().
pehrhovey	0:a548a085de55	1385	* Currently, only the MSS option is supported!
pehrhovey	0:a548a085de55	1386	*
pehrhovey	0:a548a085de55	1387	* @param pcb the tcp_pcb for which a segment arrived
pehrhovey	0:a548a085de55	1388	*/
pehrhovey	0:a548a085de55	1389	static void
pehrhovey	0:a548a085de55	1390	tcp_parseopt(struct tcp_pcb *pcb)
pehrhovey	0:a548a085de55	1391	{
pehrhovey	0:a548a085de55	1392	u16_t c, max_c;
pehrhovey	0:a548a085de55	1393	u16_t mss;
pehrhovey	0:a548a085de55	1394	u8_t *opts, opt;
pehrhovey	0:a548a085de55	1395	#if LWIP_TCP_TIMESTAMPS
pehrhovey	0:a548a085de55	1396	u32_t tsval;
pehrhovey	0:a548a085de55	1397	#endif
pehrhovey	0:a548a085de55	1398
pehrhovey	0:a548a085de55	1399	opts = (u8_t *)tcphdr + TCP_HLEN;
pehrhovey	0:a548a085de55	1400
pehrhovey	0:a548a085de55	1401	/* Parse the TCP MSS option, if present. */
pehrhovey	0:a548a085de55	1402	if(TCPH_HDRLEN(tcphdr) > 0x5) {
pehrhovey	0:a548a085de55	1403	max_c = (TCPH_HDRLEN(tcphdr) - 5) << 2;
pehrhovey	0:a548a085de55	1404	for (c = 0; c < max_c; ) {
pehrhovey	0:a548a085de55	1405	opt = opts[c];
pehrhovey	0:a548a085de55	1406	switch (opt) {
pehrhovey	0:a548a085de55	1407	case 0x00:
pehrhovey	0:a548a085de55	1408	/* End of options. */
pehrhovey	0:a548a085de55	1409	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: EOL\n"));
pehrhovey	0:a548a085de55	1410	return;
pehrhovey	0:a548a085de55	1411	case 0x01:
pehrhovey	0:a548a085de55	1412	/* NOP option. */
pehrhovey	0:a548a085de55	1413	++c;
pehrhovey	0:a548a085de55	1414	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: NOP\n"));
pehrhovey	0:a548a085de55	1415	break;
pehrhovey	0:a548a085de55	1416	case 0x02:
pehrhovey	0:a548a085de55	1417	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: MSS\n"));
pehrhovey	0:a548a085de55	1418	if (opts[c + 1] != 0x04 \|\| c + 0x04 > max_c) {
pehrhovey	0:a548a085de55	1419	/* Bad length */
pehrhovey	0:a548a085de55	1420	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: bad length\n"));
pehrhovey	0:a548a085de55	1421	return;
pehrhovey	0:a548a085de55	1422	}
pehrhovey	0:a548a085de55	1423	/* An MSS option with the right option length. */
pehrhovey	0:a548a085de55	1424	mss = (opts[c + 2] << 8) \| opts[c + 3];
pehrhovey	0:a548a085de55	1425	/* Limit the mss to the configured TCP_MSS and prevent division by zero */
pehrhovey	0:a548a085de55	1426	pcb->mss = ((mss > TCP_MSS) \|\| (mss == 0)) ? TCP_MSS : mss;
pehrhovey	0:a548a085de55	1427	/* Advance to next option */
pehrhovey	0:a548a085de55	1428	c += 0x04;
pehrhovey	0:a548a085de55	1429	break;
pehrhovey	0:a548a085de55	1430	#if LWIP_TCP_TIMESTAMPS
pehrhovey	0:a548a085de55	1431	case 0x08:
pehrhovey	0:a548a085de55	1432	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: TS\n"));
pehrhovey	0:a548a085de55	1433	if (opts[c + 1] != 0x0A \|\| c + 0x0A > max_c) {
pehrhovey	0:a548a085de55	1434	/* Bad length */
pehrhovey	0:a548a085de55	1435	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: bad length\n"));
pehrhovey	0:a548a085de55	1436	return;
pehrhovey	0:a548a085de55	1437	}
pehrhovey	0:a548a085de55	1438	/* TCP timestamp option with valid length */
pehrhovey	0:a548a085de55	1439	tsval = (opts[c+2]) \| (opts[c+3] << 8) \|
pehrhovey	0:a548a085de55	1440	(opts[c+4] << 16) \| (opts[c+5] << 24);
pehrhovey	0:a548a085de55	1441	if (flags & TCP_SYN) {
pehrhovey	0:a548a085de55	1442	pcb->ts_recent = ntohl(tsval);
pehrhovey	0:a548a085de55	1443	pcb->flags \|= TF_TIMESTAMP;
pehrhovey	0:a548a085de55	1444	} else if (TCP_SEQ_BETWEEN(pcb->ts_lastacksent, seqno, seqno+tcplen)) {
pehrhovey	0:a548a085de55	1445	pcb->ts_recent = ntohl(tsval);
pehrhovey	0:a548a085de55	1446	}
pehrhovey	0:a548a085de55	1447	/* Advance to next option */
pehrhovey	0:a548a085de55	1448	c += 0x0A;
pehrhovey	0:a548a085de55	1449	break;
pehrhovey	0:a548a085de55	1450	#endif
pehrhovey	0:a548a085de55	1451	default:
pehrhovey	0:a548a085de55	1452	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: other\n"));
pehrhovey	0:a548a085de55	1453	if (opts[c + 1] == 0) {
pehrhovey	0:a548a085de55	1454	LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: bad length\n"));
pehrhovey	0:a548a085de55	1455	/* If the length field is zero, the options are malformed
pehrhovey	0:a548a085de55	1456	and we don't process them further. */
pehrhovey	0:a548a085de55	1457	return;
pehrhovey	0:a548a085de55	1458	}
pehrhovey	0:a548a085de55	1459	/* All other options have a length field, so that we easily
pehrhovey	0:a548a085de55	1460	can skip past them. */
pehrhovey	0:a548a085de55	1461	c += opts[c + 1];
pehrhovey	0:a548a085de55	1462	}
pehrhovey	0:a548a085de55	1463	}
pehrhovey	0:a548a085de55	1464	}
pehrhovey	0:a548a085de55	1465	}
pehrhovey	0:a548a085de55	1466
pehrhovey	0:a548a085de55	1467	#endif /* LWIP_TCP */

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	14 Mar 2010
Imports:	240
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	5

Core/lwIP/core/tcp_in.c@0:a548a085de55, 2010-03-14 (annotated)

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