F7_Ethernet - Ethernet for Nucleo and Disco board STM32F746 wor…

Users » rctaduio » Code » F7_Ethernet

Patrick Ciccone / F7_Ethernet

Ethernet for Nucleo and Disco board STM32F746 works with gcc and arm. IAC is untested

Dependencies: mbed-rtos

Dependents: IMU_ethernet

Fork of F7_Ethernet by Dieter Graef

lwip/core/tcp_out.c@2:e0a4035b5cd1, 2016-10-06 (annotated)

Committer:: rctaduio
Date:: Thu Oct 06 16:55:16 2016 +0000
Revision:: 2:e0a4035b5cd1
Parent:: 0:d26c1b55cfca

Ethernet library for F7

Who changed what in which revision?

User	Revision	Line number	New contents of line
DieterGraef	0:d26c1b55cfca	1	/**
DieterGraef	0:d26c1b55cfca	2	* @file
DieterGraef	0:d26c1b55cfca	3	* Transmission Control Protocol, outgoing traffic
DieterGraef	0:d26c1b55cfca	4	*
DieterGraef	0:d26c1b55cfca	5	* The output functions of TCP.
DieterGraef	0:d26c1b55cfca	6	*
DieterGraef	0:d26c1b55cfca	7	*/
DieterGraef	0:d26c1b55cfca	8
DieterGraef	0:d26c1b55cfca	9	/*
DieterGraef	0:d26c1b55cfca	10	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
DieterGraef	0:d26c1b55cfca	11	* All rights reserved.
DieterGraef	0:d26c1b55cfca	12	*
DieterGraef	0:d26c1b55cfca	13	* Redistribution and use in source and binary forms, with or without modification,
DieterGraef	0:d26c1b55cfca	14	* are permitted provided that the following conditions are met:
DieterGraef	0:d26c1b55cfca	15	*
DieterGraef	0:d26c1b55cfca	16	* 1. Redistributions of source code must retain the above copyright notice,
DieterGraef	0:d26c1b55cfca	17	* this list of conditions and the following disclaimer.
DieterGraef	0:d26c1b55cfca	18	* 2. Redistributions in binary form must reproduce the above copyright notice,
DieterGraef	0:d26c1b55cfca	19	* this list of conditions and the following disclaimer in the documentation
DieterGraef	0:d26c1b55cfca	20	* and/or other materials provided with the distribution.
DieterGraef	0:d26c1b55cfca	21	* 3. The name of the author may not be used to endorse or promote products
DieterGraef	0:d26c1b55cfca	22	* derived from this software without specific prior written permission.
DieterGraef	0:d26c1b55cfca	23	*
DieterGraef	0:d26c1b55cfca	24	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
DieterGraef	0:d26c1b55cfca	25	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
DieterGraef	0:d26c1b55cfca	26	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
DieterGraef	0:d26c1b55cfca	27	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
DieterGraef	0:d26c1b55cfca	28	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
DieterGraef	0:d26c1b55cfca	29	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
DieterGraef	0:d26c1b55cfca	30	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
DieterGraef	0:d26c1b55cfca	31	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
DieterGraef	0:d26c1b55cfca	32	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
DieterGraef	0:d26c1b55cfca	33	* OF SUCH DAMAGE.
DieterGraef	0:d26c1b55cfca	34	*
DieterGraef	0:d26c1b55cfca	35	* This file is part of the lwIP TCP/IP stack.
DieterGraef	0:d26c1b55cfca	36	*
DieterGraef	0:d26c1b55cfca	37	* Author: Adam Dunkels <adam@sics.se>
DieterGraef	0:d26c1b55cfca	38	*
DieterGraef	0:d26c1b55cfca	39	*/
DieterGraef	0:d26c1b55cfca	40
DieterGraef	0:d26c1b55cfca	41	#include "lwip/opt.h"
DieterGraef	0:d26c1b55cfca	42
DieterGraef	0:d26c1b55cfca	43	#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
DieterGraef	0:d26c1b55cfca	44
DieterGraef	0:d26c1b55cfca	45	#include "lwip/tcp_impl.h"
DieterGraef	0:d26c1b55cfca	46	#include "lwip/def.h"
DieterGraef	0:d26c1b55cfca	47	#include "lwip/mem.h"
DieterGraef	0:d26c1b55cfca	48	#include "lwip/memp.h"
DieterGraef	0:d26c1b55cfca	49	#include "lwip/ip_addr.h"
DieterGraef	0:d26c1b55cfca	50	#include "lwip/netif.h"
DieterGraef	0:d26c1b55cfca	51	#include "lwip/inet_chksum.h"
DieterGraef	0:d26c1b55cfca	52	#include "lwip/stats.h"
DieterGraef	0:d26c1b55cfca	53	#include "lwip/snmp.h"
DieterGraef	0:d26c1b55cfca	54	#if LWIP_TCP_TIMESTAMPS
DieterGraef	0:d26c1b55cfca	55	#include "lwip/sys.h"
DieterGraef	0:d26c1b55cfca	56	#endif
DieterGraef	0:d26c1b55cfca	57
DieterGraef	0:d26c1b55cfca	58	#include <string.h>
DieterGraef	0:d26c1b55cfca	59
DieterGraef	0:d26c1b55cfca	60	/* Define some copy-macros for checksum-on-copy so that the code looks
DieterGraef	0:d26c1b55cfca	61	nicer by preventing too many ifdef's. */
DieterGraef	0:d26c1b55cfca	62	#if TCP_CHECKSUM_ON_COPY
DieterGraef	0:d26c1b55cfca	63	#define TCP_DATA_COPY(dst, src, len, seg) do { \
DieterGraef	0:d26c1b55cfca	64	tcp_seg_add_chksum(LWIP_CHKSUM_COPY(dst, src, len), \
DieterGraef	0:d26c1b55cfca	65	len, &seg->chksum, &seg->chksum_swapped); \
DieterGraef	0:d26c1b55cfca	66	seg->flags \|= TF_SEG_DATA_CHECKSUMMED; } while(0)
DieterGraef	0:d26c1b55cfca	67	#define TCP_DATA_COPY2(dst, src, len, chksum, chksum_swapped) \
DieterGraef	0:d26c1b55cfca	68	tcp_seg_add_chksum(LWIP_CHKSUM_COPY(dst, src, len), len, chksum, chksum_swapped);
DieterGraef	0:d26c1b55cfca	69	#else /* TCP_CHECKSUM_ON_COPY*/
DieterGraef	0:d26c1b55cfca	70	#define TCP_DATA_COPY(dst, src, len, seg) MEMCPY(dst, src, len)
DieterGraef	0:d26c1b55cfca	71	#define TCP_DATA_COPY2(dst, src, len, chksum, chksum_swapped) MEMCPY(dst, src, len)
DieterGraef	0:d26c1b55cfca	72	#endif /* TCP_CHECKSUM_ON_COPY*/
DieterGraef	0:d26c1b55cfca	73
DieterGraef	0:d26c1b55cfca	74	/** Define this to 1 for an extra check that the output checksum is valid
DieterGraef	0:d26c1b55cfca	75	* (usefule when the checksum is generated by the application, not the stack) */
DieterGraef	0:d26c1b55cfca	76	#ifndef TCP_CHECKSUM_ON_COPY_SANITY_CHECK
DieterGraef	0:d26c1b55cfca	77	#define TCP_CHECKSUM_ON_COPY_SANITY_CHECK 0
DieterGraef	0:d26c1b55cfca	78	#endif
DieterGraef	0:d26c1b55cfca	79
DieterGraef	0:d26c1b55cfca	80	/* Forward declarations.*/
DieterGraef	0:d26c1b55cfca	81	static void tcp_output_segment(struct tcp_seg seg, struct tcp_pcb pcb);
DieterGraef	0:d26c1b55cfca	82
DieterGraef	0:d26c1b55cfca	83	/** Allocate a pbuf and create a tcphdr at p->payload, used for output
DieterGraef	0:d26c1b55cfca	84	* functions other than the default tcp_output -> tcp_output_segment
DieterGraef	0:d26c1b55cfca	85	* (e.g. tcp_send_empty_ack, etc.)
DieterGraef	0:d26c1b55cfca	86	*
DieterGraef	0:d26c1b55cfca	87	* @param pcb tcp pcb for which to send a packet (used to initialize tcp_hdr)
DieterGraef	0:d26c1b55cfca	88	* @param optlen length of header-options
DieterGraef	0:d26c1b55cfca	89	* @param datalen length of tcp data to reserve in pbuf
DieterGraef	0:d26c1b55cfca	90	* @param seqno_be seqno in network byte order (big-endian)
DieterGraef	0:d26c1b55cfca	91	* @return pbuf with p->payload being the tcp_hdr
DieterGraef	0:d26c1b55cfca	92	*/
DieterGraef	0:d26c1b55cfca	93	static struct pbuf *
DieterGraef	0:d26c1b55cfca	94	tcp_output_alloc_header(struct tcp_pcb *pcb, u16_t optlen, u16_t datalen,
DieterGraef	0:d26c1b55cfca	95	u32_t seqno_be /* already in network byte order */)
DieterGraef	0:d26c1b55cfca	96	{
DieterGraef	0:d26c1b55cfca	97	struct tcp_hdr *tcphdr;
DieterGraef	0:d26c1b55cfca	98	struct pbuf *p = pbuf_alloc(PBUF_IP, TCP_HLEN + optlen + datalen, PBUF_RAM);
DieterGraef	0:d26c1b55cfca	99	if (p != NULL) {
DieterGraef	0:d26c1b55cfca	100	LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr",
DieterGraef	0:d26c1b55cfca	101	(p->len >= TCP_HLEN + optlen));
DieterGraef	0:d26c1b55cfca	102	tcphdr = (struct tcp_hdr *)p->payload;
DieterGraef	0:d26c1b55cfca	103	tcphdr->src = htons(pcb->local_port);
DieterGraef	0:d26c1b55cfca	104	tcphdr->dest = htons(pcb->remote_port);
DieterGraef	0:d26c1b55cfca	105	tcphdr->seqno = seqno_be;
DieterGraef	0:d26c1b55cfca	106	tcphdr->ackno = htonl(pcb->rcv_nxt);
DieterGraef	0:d26c1b55cfca	107	TCPH_HDRLEN_FLAGS_SET(tcphdr, (5 + optlen / 4), TCP_ACK);
DieterGraef	0:d26c1b55cfca	108	tcphdr->wnd = htons(pcb->rcv_ann_wnd);
DieterGraef	0:d26c1b55cfca	109	tcphdr->chksum = 0;
DieterGraef	0:d26c1b55cfca	110	tcphdr->urgp = 0;
DieterGraef	0:d26c1b55cfca	111
DieterGraef	0:d26c1b55cfca	112	/* If we're sending a packet, update the announced right window edge */
DieterGraef	0:d26c1b55cfca	113	pcb->rcv_ann_right_edge = pcb->rcv_nxt + pcb->rcv_ann_wnd;
DieterGraef	0:d26c1b55cfca	114	}
DieterGraef	0:d26c1b55cfca	115	return p;
DieterGraef	0:d26c1b55cfca	116	}
DieterGraef	0:d26c1b55cfca	117
DieterGraef	0:d26c1b55cfca	118	/**
DieterGraef	0:d26c1b55cfca	119	* Called by tcp_close() to send a segment including FIN flag but not data.
DieterGraef	0:d26c1b55cfca	120	*
DieterGraef	0:d26c1b55cfca	121	* @param pcb the tcp_pcb over which to send a segment
DieterGraef	0:d26c1b55cfca	122	* @return ERR_OK if sent, another err_t otherwise
DieterGraef	0:d26c1b55cfca	123	*/
DieterGraef	0:d26c1b55cfca	124	err_t
DieterGraef	0:d26c1b55cfca	125	tcp_send_fin(struct tcp_pcb *pcb)
DieterGraef	0:d26c1b55cfca	126	{
DieterGraef	0:d26c1b55cfca	127	/* first, try to add the fin to the last unsent segment */
DieterGraef	0:d26c1b55cfca	128	if (pcb->unsent != NULL) {
DieterGraef	0:d26c1b55cfca	129	struct tcp_seg *last_unsent;
DieterGraef	0:d26c1b55cfca	130	for (last_unsent = pcb->unsent; last_unsent->next != NULL;
DieterGraef	0:d26c1b55cfca	131	last_unsent = last_unsent->next);
DieterGraef	0:d26c1b55cfca	132
DieterGraef	0:d26c1b55cfca	133	if ((TCPH_FLAGS(last_unsent->tcphdr) & (TCP_SYN \| TCP_FIN \| TCP_RST)) == 0) {
DieterGraef	0:d26c1b55cfca	134	/* no SYN/FIN/RST flag in the header, we can add the FIN flag */
DieterGraef	0:d26c1b55cfca	135	TCPH_SET_FLAG(last_unsent->tcphdr, TCP_FIN);
DieterGraef	0:d26c1b55cfca	136	pcb->flags \|= TF_FIN;
DieterGraef	0:d26c1b55cfca	137	return ERR_OK;
DieterGraef	0:d26c1b55cfca	138	}
DieterGraef	0:d26c1b55cfca	139	}
DieterGraef	0:d26c1b55cfca	140	/* no data, no length, flags, copy=1, no optdata */
DieterGraef	0:d26c1b55cfca	141	return tcp_enqueue_flags(pcb, TCP_FIN);
DieterGraef	0:d26c1b55cfca	142	}
DieterGraef	0:d26c1b55cfca	143
DieterGraef	0:d26c1b55cfca	144	/**
DieterGraef	0:d26c1b55cfca	145	* Create a TCP segment with prefilled header.
DieterGraef	0:d26c1b55cfca	146	*
DieterGraef	0:d26c1b55cfca	147	* Called by tcp_write and tcp_enqueue_flags.
DieterGraef	0:d26c1b55cfca	148	*
DieterGraef	0:d26c1b55cfca	149	* @param pcb Protocol control block for the TCP connection.
DieterGraef	0:d26c1b55cfca	150	* @param p pbuf that is used to hold the TCP header.
DieterGraef	0:d26c1b55cfca	151	* @param flags TCP flags for header.
DieterGraef	0:d26c1b55cfca	152	* @param seqno TCP sequence number of this packet
DieterGraef	0:d26c1b55cfca	153	* @param optflags options to include in TCP header
DieterGraef	0:d26c1b55cfca	154	* @return a new tcp_seg pointing to p, or NULL.
DieterGraef	0:d26c1b55cfca	155	* The TCP header is filled in except ackno and wnd.
DieterGraef	0:d26c1b55cfca	156	* p is freed on failure.
DieterGraef	0:d26c1b55cfca	157	*/
DieterGraef	0:d26c1b55cfca	158	static struct tcp_seg *
DieterGraef	0:d26c1b55cfca	159	tcp_create_segment(struct tcp_pcb pcb, struct pbuf p, u8_t flags, u32_t seqno, u8_t optflags)
DieterGraef	0:d26c1b55cfca	160	{
DieterGraef	0:d26c1b55cfca	161	struct tcp_seg *seg;
DieterGraef	0:d26c1b55cfca	162	u8_t optlen = LWIP_TCP_OPT_LENGTH(optflags);
DieterGraef	0:d26c1b55cfca	163
DieterGraef	0:d26c1b55cfca	164	if ((seg = (struct tcp_seg *)memp_malloc(MEMP_TCP_SEG)) == NULL) {
DieterGraef	0:d26c1b55cfca	165	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| 2, ("tcp_create_segment: no memory.\n"));
DieterGraef	0:d26c1b55cfca	166	pbuf_free(p);
DieterGraef	0:d26c1b55cfca	167	return NULL;
DieterGraef	0:d26c1b55cfca	168	}
DieterGraef	0:d26c1b55cfca	169	seg->flags = optflags;
DieterGraef	0:d26c1b55cfca	170	seg->next = NULL;
DieterGraef	0:d26c1b55cfca	171	seg->p = p;
DieterGraef	0:d26c1b55cfca	172	seg->len = p->tot_len - optlen;
DieterGraef	0:d26c1b55cfca	173	#if TCP_OVERSIZE_DBGCHECK
DieterGraef	0:d26c1b55cfca	174	seg->oversize_left = 0;
DieterGraef	0:d26c1b55cfca	175	#endif /* TCP_OVERSIZE_DBGCHECK */
DieterGraef	0:d26c1b55cfca	176	#if TCP_CHECKSUM_ON_COPY
DieterGraef	0:d26c1b55cfca	177	seg->chksum = 0;
DieterGraef	0:d26c1b55cfca	178	seg->chksum_swapped = 0;
DieterGraef	0:d26c1b55cfca	179	/* check optflags */
DieterGraef	0:d26c1b55cfca	180	LWIP_ASSERT("invalid optflags passed: TF_SEG_DATA_CHECKSUMMED",
DieterGraef	0:d26c1b55cfca	181	(optflags & TF_SEG_DATA_CHECKSUMMED) == 0);
DieterGraef	0:d26c1b55cfca	182	#endif /* TCP_CHECKSUM_ON_COPY */
DieterGraef	0:d26c1b55cfca	183
DieterGraef	0:d26c1b55cfca	184	/* build TCP header */
DieterGraef	0:d26c1b55cfca	185	if (pbuf_header(p, TCP_HLEN)) {
DieterGraef	0:d26c1b55cfca	186	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| 2, ("tcp_create_segment: no room for TCP header in pbuf.\n"));
DieterGraef	0:d26c1b55cfca	187	TCP_STATS_INC(tcp.err);
DieterGraef	0:d26c1b55cfca	188	tcp_seg_free(seg);
DieterGraef	0:d26c1b55cfca	189	return NULL;
DieterGraef	0:d26c1b55cfca	190	}
DieterGraef	0:d26c1b55cfca	191	seg->tcphdr = (struct tcp_hdr *)seg->p->payload;
DieterGraef	0:d26c1b55cfca	192	seg->tcphdr->src = htons(pcb->local_port);
DieterGraef	0:d26c1b55cfca	193	seg->tcphdr->dest = htons(pcb->remote_port);
DieterGraef	0:d26c1b55cfca	194	seg->tcphdr->seqno = htonl(seqno);
DieterGraef	0:d26c1b55cfca	195	/* ackno is set in tcp_output */
DieterGraef	0:d26c1b55cfca	196	TCPH_HDRLEN_FLAGS_SET(seg->tcphdr, (5 + optlen / 4), flags);
DieterGraef	0:d26c1b55cfca	197	/* wnd and chksum are set in tcp_output */
DieterGraef	0:d26c1b55cfca	198	seg->tcphdr->urgp = 0;
DieterGraef	0:d26c1b55cfca	199	return seg;
DieterGraef	0:d26c1b55cfca	200	}
DieterGraef	0:d26c1b55cfca	201
DieterGraef	0:d26c1b55cfca	202	/**
DieterGraef	0:d26c1b55cfca	203	* Allocate a PBUF_RAM pbuf, perhaps with extra space at the end.
DieterGraef	0:d26c1b55cfca	204	*
DieterGraef	0:d26c1b55cfca	205	* This function is like pbuf_alloc(layer, length, PBUF_RAM) except
DieterGraef	0:d26c1b55cfca	206	* there may be extra bytes available at the end.
DieterGraef	0:d26c1b55cfca	207	*
DieterGraef	0:d26c1b55cfca	208	* @param layer flag to define header size.
DieterGraef	0:d26c1b55cfca	209	* @param length size of the pbuf's payload.
DieterGraef	0:d26c1b55cfca	210	* @param max_length maximum usable size of payload+oversize.
DieterGraef	0:d26c1b55cfca	211	* @param oversize pointer to a u16_t that will receive the number of usable tail bytes.
DieterGraef	0:d26c1b55cfca	212	* @param pcb The TCP connection that willo enqueue the pbuf.
DieterGraef	0:d26c1b55cfca	213	* @param apiflags API flags given to tcp_write.
DieterGraef	0:d26c1b55cfca	214	* @param first_seg true when this pbuf will be used in the first enqueued segment.
DieterGraef	0:d26c1b55cfca	215	* @param
DieterGraef	0:d26c1b55cfca	216	*/
DieterGraef	0:d26c1b55cfca	217	#if TCP_OVERSIZE
DieterGraef	0:d26c1b55cfca	218	static struct pbuf *
DieterGraef	0:d26c1b55cfca	219	tcp_pbuf_prealloc(pbuf_layer layer, u16_t length, u16_t max_length,
DieterGraef	0:d26c1b55cfca	220	u16_t oversize, struct tcp_pcb pcb, u8_t apiflags,
DieterGraef	0:d26c1b55cfca	221	u8_t first_seg)
DieterGraef	0:d26c1b55cfca	222	{
DieterGraef	0:d26c1b55cfca	223	struct pbuf *p;
DieterGraef	0:d26c1b55cfca	224	u16_t alloc = length;
DieterGraef	0:d26c1b55cfca	225
DieterGraef	0:d26c1b55cfca	226	#if LWIP_NETIF_TX_SINGLE_PBUF
DieterGraef	0:d26c1b55cfca	227	LWIP_UNUSED_ARG(max_length);
DieterGraef	0:d26c1b55cfca	228	LWIP_UNUSED_ARG(pcb);
DieterGraef	0:d26c1b55cfca	229	LWIP_UNUSED_ARG(apiflags);
DieterGraef	0:d26c1b55cfca	230	LWIP_UNUSED_ARG(first_seg);
DieterGraef	0:d26c1b55cfca	231	/* always create MSS-sized pbufs */
DieterGraef	0:d26c1b55cfca	232	alloc = max_length;
DieterGraef	0:d26c1b55cfca	233	#else /* LWIP_NETIF_TX_SINGLE_PBUF */
DieterGraef	0:d26c1b55cfca	234	if (length < max_length) {
DieterGraef	0:d26c1b55cfca	235	/* Should we allocate an oversized pbuf, or just the minimum
DieterGraef	0:d26c1b55cfca	236	* length required? If tcp_write is going to be called again
DieterGraef	0:d26c1b55cfca	237	* before this segment is transmitted, we want the oversized
DieterGraef	0:d26c1b55cfca	238	* buffer. If the segment will be transmitted immediately, we can
DieterGraef	0:d26c1b55cfca	239	* save memory by allocating only length. We use a simple
DieterGraef	0:d26c1b55cfca	240	* heuristic based on the following information:
DieterGraef	0:d26c1b55cfca	241	*
DieterGraef	0:d26c1b55cfca	242	* Did the user set TCP_WRITE_FLAG_MORE?
DieterGraef	0:d26c1b55cfca	243	*
DieterGraef	0:d26c1b55cfca	244	* Will the Nagle algorithm defer transmission of this segment?
DieterGraef	0:d26c1b55cfca	245	*/
DieterGraef	0:d26c1b55cfca	246	if ((apiflags & TCP_WRITE_FLAG_MORE) \|\|
DieterGraef	0:d26c1b55cfca	247	(!(pcb->flags & TF_NODELAY) &&
DieterGraef	0:d26c1b55cfca	248	(!first_seg \|\|
DieterGraef	0:d26c1b55cfca	249	pcb->unsent != NULL \|\|
DieterGraef	0:d26c1b55cfca	250	pcb->unacked != NULL))) {
DieterGraef	0:d26c1b55cfca	251	alloc = LWIP_MIN(max_length, LWIP_MEM_ALIGN_SIZE(length + TCP_OVERSIZE));
DieterGraef	0:d26c1b55cfca	252	}
DieterGraef	0:d26c1b55cfca	253	}
DieterGraef	0:d26c1b55cfca	254	#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
DieterGraef	0:d26c1b55cfca	255	p = pbuf_alloc(layer, alloc, PBUF_RAM);
DieterGraef	0:d26c1b55cfca	256	if (p == NULL) {
DieterGraef	0:d26c1b55cfca	257	return NULL;
DieterGraef	0:d26c1b55cfca	258	}
DieterGraef	0:d26c1b55cfca	259	LWIP_ASSERT("need unchained pbuf", p->next == NULL);
DieterGraef	0:d26c1b55cfca	260	*oversize = p->len - length;
DieterGraef	0:d26c1b55cfca	261	/* trim p->len to the currently used size */
DieterGraef	0:d26c1b55cfca	262	p->len = p->tot_len = length;
DieterGraef	0:d26c1b55cfca	263	return p;
DieterGraef	0:d26c1b55cfca	264	}
DieterGraef	0:d26c1b55cfca	265	#else /* TCP_OVERSIZE */
DieterGraef	0:d26c1b55cfca	266	#define tcp_pbuf_prealloc(layer, length, mx, os, pcb, api, fst) pbuf_alloc((layer), (length), PBUF_RAM)
DieterGraef	0:d26c1b55cfca	267	#endif /* TCP_OVERSIZE */
DieterGraef	0:d26c1b55cfca	268
DieterGraef	0:d26c1b55cfca	269	#if TCP_CHECKSUM_ON_COPY
DieterGraef	0:d26c1b55cfca	270	/** Add a checksum of newly added data to the segment */
DieterGraef	0:d26c1b55cfca	271	static void
DieterGraef	0:d26c1b55cfca	272	tcp_seg_add_chksum(u16_t chksum, u16_t len, u16_t *seg_chksum,
DieterGraef	0:d26c1b55cfca	273	u8_t *seg_chksum_swapped)
DieterGraef	0:d26c1b55cfca	274	{
DieterGraef	0:d26c1b55cfca	275	u32_t helper;
DieterGraef	0:d26c1b55cfca	276	/* add chksum to old chksum and fold to u16_t */
DieterGraef	0:d26c1b55cfca	277	helper = chksum + *seg_chksum;
DieterGraef	0:d26c1b55cfca	278	chksum = FOLD_U32T(helper);
DieterGraef	0:d26c1b55cfca	279	if ((len & 1) != 0) {
DieterGraef	0:d26c1b55cfca	280	seg_chksum_swapped = 1 - seg_chksum_swapped;
DieterGraef	0:d26c1b55cfca	281	chksum = SWAP_BYTES_IN_WORD(chksum);
DieterGraef	0:d26c1b55cfca	282	}
DieterGraef	0:d26c1b55cfca	283	*seg_chksum = chksum;
DieterGraef	0:d26c1b55cfca	284	}
DieterGraef	0:d26c1b55cfca	285	#endif /* TCP_CHECKSUM_ON_COPY */
DieterGraef	0:d26c1b55cfca	286
DieterGraef	0:d26c1b55cfca	287	/** Checks if tcp_write is allowed or not (checks state, snd_buf and snd_queuelen).
DieterGraef	0:d26c1b55cfca	288	*
DieterGraef	0:d26c1b55cfca	289	* @param pcb the tcp pcb to check for
DieterGraef	0:d26c1b55cfca	290	* @param len length of data to send (checked agains snd_buf)
DieterGraef	0:d26c1b55cfca	291	* @return ERR_OK if tcp_write is allowed to proceed, another err_t otherwise
DieterGraef	0:d26c1b55cfca	292	*/
DieterGraef	0:d26c1b55cfca	293	static err_t
DieterGraef	0:d26c1b55cfca	294	tcp_write_checks(struct tcp_pcb *pcb, u16_t len)
DieterGraef	0:d26c1b55cfca	295	{
DieterGraef	0:d26c1b55cfca	296	/* connection is in invalid state for data transmission? */
DieterGraef	0:d26c1b55cfca	297	if ((pcb->state != ESTABLISHED) &&
DieterGraef	0:d26c1b55cfca	298	(pcb->state != CLOSE_WAIT) &&
DieterGraef	0:d26c1b55cfca	299	(pcb->state != SYN_SENT) &&
DieterGraef	0:d26c1b55cfca	300	(pcb->state != SYN_RCVD)) {
DieterGraef	0:d26c1b55cfca	301	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| LWIP_DBG_STATE \| LWIP_DBG_LEVEL_SEVERE, ("tcp_write() called in invalid state\n"));
DieterGraef	0:d26c1b55cfca	302	return ERR_CONN;
DieterGraef	0:d26c1b55cfca	303	} else if (len == 0) {
DieterGraef	0:d26c1b55cfca	304	return ERR_OK;
DieterGraef	0:d26c1b55cfca	305	}
DieterGraef	0:d26c1b55cfca	306
DieterGraef	0:d26c1b55cfca	307	/* fail on too much data */
DieterGraef	0:d26c1b55cfca	308	if (len > pcb->snd_buf) {
DieterGraef	0:d26c1b55cfca	309	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| 3, ("tcp_write: too much data (len=%"U16_F" > snd_buf=%"U16_F")\n",
DieterGraef	0:d26c1b55cfca	310	len, pcb->snd_buf));
DieterGraef	0:d26c1b55cfca	311	pcb->flags \|= TF_NAGLEMEMERR;
DieterGraef	0:d26c1b55cfca	312	return ERR_MEM;
DieterGraef	0:d26c1b55cfca	313	}
DieterGraef	0:d26c1b55cfca	314
DieterGraef	0:d26c1b55cfca	315	LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen));
DieterGraef	0:d26c1b55cfca	316
DieterGraef	0:d26c1b55cfca	317	/* If total number of pbufs on the unsent/unacked queues exceeds the
DieterGraef	0:d26c1b55cfca	318	* configured maximum, return an error */
DieterGraef	0:d26c1b55cfca	319	/* check for configured max queuelen and possible overflow */
DieterGraef	0:d26c1b55cfca	320	if ((pcb->snd_queuelen >= TCP_SND_QUEUELEN) \|\| (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
DieterGraef	0:d26c1b55cfca	321	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| 3, ("tcp_write: too long queue %"U16_F" (max %"U16_F")\n",
DieterGraef	0:d26c1b55cfca	322	pcb->snd_queuelen, TCP_SND_QUEUELEN));
DieterGraef	0:d26c1b55cfca	323	TCP_STATS_INC(tcp.memerr);
DieterGraef	0:d26c1b55cfca	324	pcb->flags \|= TF_NAGLEMEMERR;
DieterGraef	0:d26c1b55cfca	325	return ERR_MEM;
DieterGraef	0:d26c1b55cfca	326	}
DieterGraef	0:d26c1b55cfca	327	if (pcb->snd_queuelen != 0) {
DieterGraef	0:d26c1b55cfca	328	LWIP_ASSERT("tcp_write: pbufs on queue => at least one queue non-empty",
DieterGraef	0:d26c1b55cfca	329	pcb->unacked != NULL \|\| pcb->unsent != NULL);
DieterGraef	0:d26c1b55cfca	330	} else {
DieterGraef	0:d26c1b55cfca	331	LWIP_ASSERT("tcp_write: no pbufs on queue => both queues empty",
DieterGraef	0:d26c1b55cfca	332	pcb->unacked == NULL && pcb->unsent == NULL);
DieterGraef	0:d26c1b55cfca	333	}
DieterGraef	0:d26c1b55cfca	334	return ERR_OK;
DieterGraef	0:d26c1b55cfca	335	}
DieterGraef	0:d26c1b55cfca	336
DieterGraef	0:d26c1b55cfca	337	/**
DieterGraef	0:d26c1b55cfca	338	* Write data for sending (but does not send it immediately).
DieterGraef	0:d26c1b55cfca	339	*
DieterGraef	0:d26c1b55cfca	340	* It waits in the expectation of more data being sent soon (as
DieterGraef	0:d26c1b55cfca	341	* it can send them more efficiently by combining them together).
DieterGraef	0:d26c1b55cfca	342	* To prompt the system to send data now, call tcp_output() after
DieterGraef	0:d26c1b55cfca	343	* calling tcp_write().
DieterGraef	0:d26c1b55cfca	344	*
DieterGraef	0:d26c1b55cfca	345	* @param pcb Protocol control block for the TCP connection to enqueue data for.
DieterGraef	0:d26c1b55cfca	346	* @param arg Pointer to the data to be enqueued for sending.
DieterGraef	0:d26c1b55cfca	347	* @param len Data length in bytes
DieterGraef	0:d26c1b55cfca	348	* @param apiflags combination of following flags :
DieterGraef	0:d26c1b55cfca	349	* - TCP_WRITE_FLAG_COPY (0x01) data will be copied into memory belonging to the stack
DieterGraef	0:d26c1b55cfca	350	* - TCP_WRITE_FLAG_MORE (0x02) for TCP connection, PSH flag will be set on last segment sent,
DieterGraef	0:d26c1b55cfca	351	* @return ERR_OK if enqueued, another err_t on error
DieterGraef	0:d26c1b55cfca	352	*/
DieterGraef	0:d26c1b55cfca	353	err_t
DieterGraef	0:d26c1b55cfca	354	tcp_write(struct tcp_pcb pcb, const void arg, u16_t len, u8_t apiflags)
DieterGraef	0:d26c1b55cfca	355	{
DieterGraef	0:d26c1b55cfca	356	struct pbuf *concat_p = NULL;
DieterGraef	0:d26c1b55cfca	357	struct tcp_seg last_unsent = NULL, seg = NULL, prev_seg = NULL, queue = NULL;
DieterGraef	0:d26c1b55cfca	358	u16_t pos = 0; /* position in 'arg' data */
DieterGraef	0:d26c1b55cfca	359	u16_t queuelen;
DieterGraef	0:d26c1b55cfca	360	u8_t optlen = 0;
DieterGraef	0:d26c1b55cfca	361	u8_t optflags = 0;
DieterGraef	0:d26c1b55cfca	362	#if TCP_OVERSIZE
DieterGraef	0:d26c1b55cfca	363	u16_t oversize = 0;
DieterGraef	0:d26c1b55cfca	364	u16_t oversize_used = 0;
DieterGraef	0:d26c1b55cfca	365	#endif /* TCP_OVERSIZE */
DieterGraef	0:d26c1b55cfca	366	#if TCP_CHECKSUM_ON_COPY
DieterGraef	0:d26c1b55cfca	367	u16_t concat_chksum = 0;
DieterGraef	0:d26c1b55cfca	368	u8_t concat_chksum_swapped = 0;
DieterGraef	0:d26c1b55cfca	369	u16_t concat_chksummed = 0;
DieterGraef	0:d26c1b55cfca	370	#endif /* TCP_CHECKSUM_ON_COPY */
DieterGraef	0:d26c1b55cfca	371	err_t err;
DieterGraef	0:d26c1b55cfca	372	/* don't allocate segments bigger than half the maximum window we ever received */
DieterGraef	0:d26c1b55cfca	373	u16_t mss_local = LWIP_MIN(pcb->mss, pcb->snd_wnd_max/2);
DieterGraef	0:d26c1b55cfca	374
DieterGraef	0:d26c1b55cfca	375	#if LWIP_NETIF_TX_SINGLE_PBUF
DieterGraef	0:d26c1b55cfca	376	/* Always copy to try to create single pbufs for TX */
DieterGraef	0:d26c1b55cfca	377	apiflags \|= TCP_WRITE_FLAG_COPY;
DieterGraef	0:d26c1b55cfca	378	#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
DieterGraef	0:d26c1b55cfca	379
DieterGraef	0:d26c1b55cfca	380	LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_write(pcb=%p, data=%p, len=%"U16_F", apiflags=%"U16_F")\n",
DieterGraef	0:d26c1b55cfca	381	(void *)pcb, arg, len, (u16_t)apiflags));
DieterGraef	0:d26c1b55cfca	382	LWIP_ERROR("tcp_write: arg == NULL (programmer violates API)",
DieterGraef	0:d26c1b55cfca	383	arg != NULL, return ERR_ARG;);
DieterGraef	0:d26c1b55cfca	384
DieterGraef	0:d26c1b55cfca	385	err = tcp_write_checks(pcb, len);
DieterGraef	0:d26c1b55cfca	386	if (err != ERR_OK) {
DieterGraef	0:d26c1b55cfca	387	return err;
DieterGraef	0:d26c1b55cfca	388	}
DieterGraef	0:d26c1b55cfca	389	queuelen = pcb->snd_queuelen;
DieterGraef	0:d26c1b55cfca	390
DieterGraef	0:d26c1b55cfca	391	#if LWIP_TCP_TIMESTAMPS
DieterGraef	0:d26c1b55cfca	392	if ((pcb->flags & TF_TIMESTAMP)) {
DieterGraef	0:d26c1b55cfca	393	optflags = TF_SEG_OPTS_TS;
DieterGraef	0:d26c1b55cfca	394	optlen = LWIP_TCP_OPT_LENGTH(TF_SEG_OPTS_TS);
DieterGraef	0:d26c1b55cfca	395	}
DieterGraef	0:d26c1b55cfca	396	#endif /* LWIP_TCP_TIMESTAMPS */
DieterGraef	0:d26c1b55cfca	397
DieterGraef	0:d26c1b55cfca	398
DieterGraef	0:d26c1b55cfca	399	/*
DieterGraef	0:d26c1b55cfca	400	* TCP segmentation is done in three phases with increasing complexity:
DieterGraef	0:d26c1b55cfca	401	*
DieterGraef	0:d26c1b55cfca	402	* 1. Copy data directly into an oversized pbuf.
DieterGraef	0:d26c1b55cfca	403	* 2. Chain a new pbuf to the end of pcb->unsent.
DieterGraef	0:d26c1b55cfca	404	* 3. Create new segments.
DieterGraef	0:d26c1b55cfca	405	*
DieterGraef	0:d26c1b55cfca	406	* We may run out of memory at any point. In that case we must
DieterGraef	0:d26c1b55cfca	407	* return ERR_MEM and not change anything in pcb. Therefore, all
DieterGraef	0:d26c1b55cfca	408	* changes are recorded in local variables and committed at the end
DieterGraef	0:d26c1b55cfca	409	* of the function. Some pcb fields are maintained in local copies:
DieterGraef	0:d26c1b55cfca	410	*
DieterGraef	0:d26c1b55cfca	411	* queuelen = pcb->snd_queuelen
DieterGraef	0:d26c1b55cfca	412	* oversize = pcb->unsent_oversize
DieterGraef	0:d26c1b55cfca	413	*
DieterGraef	0:d26c1b55cfca	414	* These variables are set consistently by the phases:
DieterGraef	0:d26c1b55cfca	415	*
DieterGraef	0:d26c1b55cfca	416	* seg points to the last segment tampered with.
DieterGraef	0:d26c1b55cfca	417	*
DieterGraef	0:d26c1b55cfca	418	* pos records progress as data is segmented.
DieterGraef	0:d26c1b55cfca	419	*/
DieterGraef	0:d26c1b55cfca	420
DieterGraef	0:d26c1b55cfca	421	/* Find the tail of the unsent queue. */
DieterGraef	0:d26c1b55cfca	422	if (pcb->unsent != NULL) {
DieterGraef	0:d26c1b55cfca	423	u16_t space;
DieterGraef	0:d26c1b55cfca	424	u16_t unsent_optlen;
DieterGraef	0:d26c1b55cfca	425
DieterGraef	0:d26c1b55cfca	426	/* @todo: this could be sped up by keeping last_unsent in the pcb */
DieterGraef	0:d26c1b55cfca	427	for (last_unsent = pcb->unsent; last_unsent->next != NULL;
DieterGraef	0:d26c1b55cfca	428	last_unsent = last_unsent->next);
DieterGraef	0:d26c1b55cfca	429
DieterGraef	0:d26c1b55cfca	430	/* Usable space at the end of the last unsent segment */
DieterGraef	0:d26c1b55cfca	431	unsent_optlen = LWIP_TCP_OPT_LENGTH(last_unsent->flags);
DieterGraef	0:d26c1b55cfca	432	space = mss_local - (last_unsent->len + unsent_optlen);
DieterGraef	0:d26c1b55cfca	433
DieterGraef	0:d26c1b55cfca	434	/*
DieterGraef	0:d26c1b55cfca	435	* Phase 1: Copy data directly into an oversized pbuf.
DieterGraef	0:d26c1b55cfca	436	*
DieterGraef	0:d26c1b55cfca	437	* The number of bytes copied is recorded in the oversize_used
DieterGraef	0:d26c1b55cfca	438	* variable. The actual copying is done at the bottom of the
DieterGraef	0:d26c1b55cfca	439	* function.
DieterGraef	0:d26c1b55cfca	440	*/
DieterGraef	0:d26c1b55cfca	441	#if TCP_OVERSIZE
DieterGraef	0:d26c1b55cfca	442	#if TCP_OVERSIZE_DBGCHECK
DieterGraef	0:d26c1b55cfca	443	/* check that pcb->unsent_oversize matches last_unsent->unsent_oversize */
DieterGraef	0:d26c1b55cfca	444	LWIP_ASSERT("unsent_oversize mismatch (pcb vs. last_unsent)",
DieterGraef	0:d26c1b55cfca	445	pcb->unsent_oversize == last_unsent->oversize_left);
DieterGraef	0:d26c1b55cfca	446	#endif /* TCP_OVERSIZE_DBGCHECK */
DieterGraef	0:d26c1b55cfca	447	oversize = pcb->unsent_oversize;
DieterGraef	0:d26c1b55cfca	448	if (oversize > 0) {
DieterGraef	0:d26c1b55cfca	449	LWIP_ASSERT("inconsistent oversize vs. space", oversize_used <= space);
DieterGraef	0:d26c1b55cfca	450	seg = last_unsent;
DieterGraef	0:d26c1b55cfca	451	oversize_used = oversize < len ? oversize : len;
DieterGraef	0:d26c1b55cfca	452	pos += oversize_used;
DieterGraef	0:d26c1b55cfca	453	oversize -= oversize_used;
DieterGraef	0:d26c1b55cfca	454	space -= oversize_used;
DieterGraef	0:d26c1b55cfca	455	}
DieterGraef	0:d26c1b55cfca	456	/* now we are either finished or oversize is zero */
DieterGraef	0:d26c1b55cfca	457	LWIP_ASSERT("inconsistend oversize vs. len", (oversize == 0) \|\| (pos == len));
DieterGraef	0:d26c1b55cfca	458	#endif /* TCP_OVERSIZE */
DieterGraef	0:d26c1b55cfca	459
DieterGraef	0:d26c1b55cfca	460	/*
DieterGraef	0:d26c1b55cfca	461	* Phase 2: Chain a new pbuf to the end of pcb->unsent.
DieterGraef	0:d26c1b55cfca	462	*
DieterGraef	0:d26c1b55cfca	463	* We don't extend segments containing SYN/FIN flags or options
DieterGraef	0:d26c1b55cfca	464	* (len==0). The new pbuf is kept in concat_p and pbuf_cat'ed at
DieterGraef	0:d26c1b55cfca	465	* the end.
DieterGraef	0:d26c1b55cfca	466	*/
DieterGraef	0:d26c1b55cfca	467	if ((pos < len) && (space > 0) && (last_unsent->len > 0)) {
DieterGraef	0:d26c1b55cfca	468	u16_t seglen = space < len - pos ? space : len - pos;
DieterGraef	0:d26c1b55cfca	469	seg = last_unsent;
DieterGraef	0:d26c1b55cfca	470
DieterGraef	0:d26c1b55cfca	471	/* Create a pbuf with a copy or reference to seglen bytes. We
DieterGraef	0:d26c1b55cfca	472	* can use PBUF_RAW here since the data appears in the middle of
DieterGraef	0:d26c1b55cfca	473	* a segment. A header will never be prepended. */
DieterGraef	0:d26c1b55cfca	474	if (apiflags & TCP_WRITE_FLAG_COPY) {
DieterGraef	0:d26c1b55cfca	475	/* Data is copied */
DieterGraef	0:d26c1b55cfca	476	if ((concat_p = tcp_pbuf_prealloc(PBUF_RAW, seglen, space, &oversize, pcb, apiflags, 1)) == NULL) {
DieterGraef	0:d26c1b55cfca	477	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| 2,
DieterGraef	0:d26c1b55cfca	478	("tcp_write : could not allocate memory for pbuf copy size %"U16_F"\n",
DieterGraef	0:d26c1b55cfca	479	seglen));
DieterGraef	0:d26c1b55cfca	480	goto memerr;
DieterGraef	0:d26c1b55cfca	481	}
DieterGraef	0:d26c1b55cfca	482	#if TCP_OVERSIZE_DBGCHECK
DieterGraef	0:d26c1b55cfca	483	last_unsent->oversize_left += oversize;
DieterGraef	0:d26c1b55cfca	484	#endif /* TCP_OVERSIZE_DBGCHECK */
DieterGraef	0:d26c1b55cfca	485	TCP_DATA_COPY2(concat_p->payload, (u8_t*)arg + pos, seglen, &concat_chksum, &concat_chksum_swapped);
DieterGraef	0:d26c1b55cfca	486	#if TCP_CHECKSUM_ON_COPY
DieterGraef	0:d26c1b55cfca	487	concat_chksummed += seglen;
DieterGraef	0:d26c1b55cfca	488	#endif /* TCP_CHECKSUM_ON_COPY */
DieterGraef	0:d26c1b55cfca	489	} else {
DieterGraef	0:d26c1b55cfca	490	/* Data is not copied */
DieterGraef	0:d26c1b55cfca	491	if ((concat_p = pbuf_alloc(PBUF_RAW, seglen, PBUF_ROM)) == NULL) {
DieterGraef	0:d26c1b55cfca	492	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| 2,
DieterGraef	0:d26c1b55cfca	493	("tcp_write: could not allocate memory for zero-copy pbuf\n"));
DieterGraef	0:d26c1b55cfca	494	goto memerr;
DieterGraef	0:d26c1b55cfca	495	}
DieterGraef	0:d26c1b55cfca	496	#if TCP_CHECKSUM_ON_COPY
DieterGraef	0:d26c1b55cfca	497	/* calculate the checksum of nocopy-data */
DieterGraef	0:d26c1b55cfca	498	tcp_seg_add_chksum(~inet_chksum((u8_t*)arg + pos, seglen), seglen,
DieterGraef	0:d26c1b55cfca	499	&concat_chksum, &concat_chksum_swapped);
DieterGraef	0:d26c1b55cfca	500	concat_chksummed += seglen;
DieterGraef	0:d26c1b55cfca	501	#endif /* TCP_CHECKSUM_ON_COPY */
DieterGraef	0:d26c1b55cfca	502	/* reference the non-volatile payload data */
DieterGraef	0:d26c1b55cfca	503	concat_p->payload = (u8_t*)arg + pos;
DieterGraef	0:d26c1b55cfca	504	}
DieterGraef	0:d26c1b55cfca	505
DieterGraef	0:d26c1b55cfca	506	pos += seglen;
DieterGraef	0:d26c1b55cfca	507	queuelen += pbuf_clen(concat_p);
DieterGraef	0:d26c1b55cfca	508	}
DieterGraef	0:d26c1b55cfca	509	} else {
DieterGraef	0:d26c1b55cfca	510	#if TCP_OVERSIZE
DieterGraef	0:d26c1b55cfca	511	LWIP_ASSERT("unsent_oversize mismatch (pcb->unsent is NULL)",
DieterGraef	0:d26c1b55cfca	512	pcb->unsent_oversize == 0);
DieterGraef	0:d26c1b55cfca	513	#endif /* TCP_OVERSIZE */
DieterGraef	0:d26c1b55cfca	514	}
DieterGraef	0:d26c1b55cfca	515
DieterGraef	0:d26c1b55cfca	516	/*
DieterGraef	0:d26c1b55cfca	517	* Phase 3: Create new segments.
DieterGraef	0:d26c1b55cfca	518	*
DieterGraef	0:d26c1b55cfca	519	* The new segments are chained together in the local 'queue'
DieterGraef	0:d26c1b55cfca	520	* variable, ready to be appended to pcb->unsent.
DieterGraef	0:d26c1b55cfca	521	*/
DieterGraef	0:d26c1b55cfca	522	while (pos < len) {
DieterGraef	0:d26c1b55cfca	523	struct pbuf *p;
DieterGraef	0:d26c1b55cfca	524	u16_t left = len - pos;
DieterGraef	0:d26c1b55cfca	525	u16_t max_len = mss_local - optlen;
DieterGraef	0:d26c1b55cfca	526	u16_t seglen = left > max_len ? max_len : left;
DieterGraef	0:d26c1b55cfca	527	#if TCP_CHECKSUM_ON_COPY
DieterGraef	0:d26c1b55cfca	528	u16_t chksum = 0;
DieterGraef	0:d26c1b55cfca	529	u8_t chksum_swapped = 0;
DieterGraef	0:d26c1b55cfca	530	#endif /* TCP_CHECKSUM_ON_COPY */
DieterGraef	0:d26c1b55cfca	531
DieterGraef	0:d26c1b55cfca	532	if (apiflags & TCP_WRITE_FLAG_COPY) {
DieterGraef	0:d26c1b55cfca	533	/* If copy is set, memory should be allocated and data copied
DieterGraef	0:d26c1b55cfca	534	* into pbuf */
DieterGraef	0:d26c1b55cfca	535	if ((p = tcp_pbuf_prealloc(PBUF_TRANSPORT, seglen + optlen, mss_local, &oversize, pcb, apiflags, queue == NULL)) == NULL) {
DieterGraef	0:d26c1b55cfca	536	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| 2, ("tcp_write : could not allocate memory for pbuf copy size %"U16_F"\n", seglen));
DieterGraef	0:d26c1b55cfca	537	goto memerr;
DieterGraef	0:d26c1b55cfca	538	}
DieterGraef	0:d26c1b55cfca	539	LWIP_ASSERT("tcp_write: check that first pbuf can hold the complete seglen",
DieterGraef	0:d26c1b55cfca	540	(p->len >= seglen));
DieterGraef	0:d26c1b55cfca	541	TCP_DATA_COPY2((char )p->payload + optlen, (u8_t)arg + pos, seglen, &chksum, &chksum_swapped);
DieterGraef	0:d26c1b55cfca	542	} else {
DieterGraef	0:d26c1b55cfca	543	/* Copy is not set: First allocate a pbuf for holding the data.
DieterGraef	0:d26c1b55cfca	544	* Since the referenced data is available at least until it is
DieterGraef	0:d26c1b55cfca	545	* sent out on the link (as it has to be ACKed by the remote
DieterGraef	0:d26c1b55cfca	546	* party) we can safely use PBUF_ROM instead of PBUF_REF here.
DieterGraef	0:d26c1b55cfca	547	*/
DieterGraef	0:d26c1b55cfca	548	struct pbuf *p2;
DieterGraef	0:d26c1b55cfca	549	#if TCP_OVERSIZE
DieterGraef	0:d26c1b55cfca	550	LWIP_ASSERT("oversize == 0", oversize == 0);
DieterGraef	0:d26c1b55cfca	551	#endif /* TCP_OVERSIZE */
DieterGraef	0:d26c1b55cfca	552	if ((p2 = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_ROM)) == NULL) {
DieterGraef	0:d26c1b55cfca	553	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| 2, ("tcp_write: could not allocate memory for zero-copy pbuf\n"));
DieterGraef	0:d26c1b55cfca	554	goto memerr;
DieterGraef	0:d26c1b55cfca	555	}
DieterGraef	0:d26c1b55cfca	556	#if TCP_CHECKSUM_ON_COPY
DieterGraef	0:d26c1b55cfca	557	/* calculate the checksum of nocopy-data */
DieterGraef	0:d26c1b55cfca	558	chksum = ~inet_chksum((u8_t*)arg + pos, seglen);
DieterGraef	0:d26c1b55cfca	559	#endif /* TCP_CHECKSUM_ON_COPY */
DieterGraef	0:d26c1b55cfca	560	/* reference the non-volatile payload data */
DieterGraef	0:d26c1b55cfca	561	p2->payload = (u8_t*)arg + pos;
DieterGraef	0:d26c1b55cfca	562
DieterGraef	0:d26c1b55cfca	563	/* Second, allocate a pbuf for the headers. */
DieterGraef	0:d26c1b55cfca	564	if ((p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) {
DieterGraef	0:d26c1b55cfca	565	/* If allocation fails, we have to deallocate the data pbuf as
DieterGraef	0:d26c1b55cfca	566	* well. */
DieterGraef	0:d26c1b55cfca	567	pbuf_free(p2);
DieterGraef	0:d26c1b55cfca	568	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| 2, ("tcp_write: could not allocate memory for header pbuf\n"));
DieterGraef	0:d26c1b55cfca	569	goto memerr;
DieterGraef	0:d26c1b55cfca	570	}
DieterGraef	0:d26c1b55cfca	571	/* Concatenate the headers and data pbufs together. */
DieterGraef	0:d26c1b55cfca	572	pbuf_cat(p/header/, p2/data/);
DieterGraef	0:d26c1b55cfca	573	}
DieterGraef	0:d26c1b55cfca	574
DieterGraef	0:d26c1b55cfca	575	queuelen += pbuf_clen(p);
DieterGraef	0:d26c1b55cfca	576
DieterGraef	0:d26c1b55cfca	577	/* Now that there are more segments queued, we check again if the
DieterGraef	0:d26c1b55cfca	578	* length of the queue exceeds the configured maximum or
DieterGraef	0:d26c1b55cfca	579	* overflows. */
DieterGraef	0:d26c1b55cfca	580	if ((queuelen > TCP_SND_QUEUELEN) \|\| (queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
DieterGraef	0:d26c1b55cfca	581	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| 2, ("tcp_write: queue too long %"U16_F" (%"U16_F")\n", queuelen, TCP_SND_QUEUELEN));
DieterGraef	0:d26c1b55cfca	582	pbuf_free(p);
DieterGraef	0:d26c1b55cfca	583	goto memerr;
DieterGraef	0:d26c1b55cfca	584	}
DieterGraef	0:d26c1b55cfca	585
DieterGraef	0:d26c1b55cfca	586	if ((seg = tcp_create_segment(pcb, p, 0, pcb->snd_lbb + pos, optflags)) == NULL) {
DieterGraef	0:d26c1b55cfca	587	goto memerr;
DieterGraef	0:d26c1b55cfca	588	}
DieterGraef	0:d26c1b55cfca	589	#if TCP_OVERSIZE_DBGCHECK
DieterGraef	0:d26c1b55cfca	590	seg->oversize_left = oversize;
DieterGraef	0:d26c1b55cfca	591	#endif /* TCP_OVERSIZE_DBGCHECK */
DieterGraef	0:d26c1b55cfca	592	#if TCP_CHECKSUM_ON_COPY
DieterGraef	0:d26c1b55cfca	593	seg->chksum = chksum;
DieterGraef	0:d26c1b55cfca	594	seg->chksum_swapped = chksum_swapped;
DieterGraef	0:d26c1b55cfca	595	seg->flags \|= TF_SEG_DATA_CHECKSUMMED;
DieterGraef	0:d26c1b55cfca	596	#endif /* TCP_CHECKSUM_ON_COPY */
DieterGraef	0:d26c1b55cfca	597
DieterGraef	0:d26c1b55cfca	598	/* first segment of to-be-queued data? */
DieterGraef	0:d26c1b55cfca	599	if (queue == NULL) {
DieterGraef	0:d26c1b55cfca	600	queue = seg;
DieterGraef	0:d26c1b55cfca	601	} else {
DieterGraef	0:d26c1b55cfca	602	/* Attach the segment to the end of the queued segments */
DieterGraef	0:d26c1b55cfca	603	LWIP_ASSERT("prev_seg != NULL", prev_seg != NULL);
DieterGraef	0:d26c1b55cfca	604	prev_seg->next = seg;
DieterGraef	0:d26c1b55cfca	605	}
DieterGraef	0:d26c1b55cfca	606	/* remember last segment of to-be-queued data for next iteration */
DieterGraef	0:d26c1b55cfca	607	prev_seg = seg;
DieterGraef	0:d26c1b55cfca	608
DieterGraef	0:d26c1b55cfca	609	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| LWIP_DBG_TRACE, ("tcp_write: queueing %"U32_F":%"U32_F"\n",
DieterGraef	0:d26c1b55cfca	610	ntohl(seg->tcphdr->seqno),
DieterGraef	0:d26c1b55cfca	611	ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg)));
DieterGraef	0:d26c1b55cfca	612
DieterGraef	0:d26c1b55cfca	613	pos += seglen;
DieterGraef	0:d26c1b55cfca	614	}
DieterGraef	0:d26c1b55cfca	615
DieterGraef	0:d26c1b55cfca	616	/*
DieterGraef	0:d26c1b55cfca	617	* All three segmentation phases were successful. We can commit the
DieterGraef	0:d26c1b55cfca	618	* transaction.
DieterGraef	0:d26c1b55cfca	619	*/
DieterGraef	0:d26c1b55cfca	620
DieterGraef	0:d26c1b55cfca	621	/*
DieterGraef	0:d26c1b55cfca	622	* Phase 1: If data has been added to the preallocated tail of
DieterGraef	0:d26c1b55cfca	623	* last_unsent, we update the length fields of the pbuf chain.
DieterGraef	0:d26c1b55cfca	624	*/
DieterGraef	0:d26c1b55cfca	625	#if TCP_OVERSIZE
DieterGraef	0:d26c1b55cfca	626	if (oversize_used > 0) {
DieterGraef	0:d26c1b55cfca	627	struct pbuf *p;
DieterGraef	0:d26c1b55cfca	628	/* Bump tot_len of whole chain, len of tail */
DieterGraef	0:d26c1b55cfca	629	for (p = last_unsent->p; p; p = p->next) {
DieterGraef	0:d26c1b55cfca	630	p->tot_len += oversize_used;
DieterGraef	0:d26c1b55cfca	631	if (p->next == NULL) {
DieterGraef	0:d26c1b55cfca	632	TCP_DATA_COPY((char *)p->payload + p->len, arg, oversize_used, last_unsent);
DieterGraef	0:d26c1b55cfca	633	p->len += oversize_used;
DieterGraef	0:d26c1b55cfca	634	}
DieterGraef	0:d26c1b55cfca	635	}
DieterGraef	0:d26c1b55cfca	636	last_unsent->len += oversize_used;
DieterGraef	0:d26c1b55cfca	637	#if TCP_OVERSIZE_DBGCHECK
DieterGraef	0:d26c1b55cfca	638	LWIP_ASSERT("last_unsent->oversize_left >= oversize_used",
DieterGraef	0:d26c1b55cfca	639	last_unsent->oversize_left >= oversize_used);
DieterGraef	0:d26c1b55cfca	640	last_unsent->oversize_left -= oversize_used;
DieterGraef	0:d26c1b55cfca	641	#endif /* TCP_OVERSIZE_DBGCHECK */
DieterGraef	0:d26c1b55cfca	642	}
DieterGraef	0:d26c1b55cfca	643	pcb->unsent_oversize = oversize;
DieterGraef	0:d26c1b55cfca	644	#endif /* TCP_OVERSIZE */
DieterGraef	0:d26c1b55cfca	645
DieterGraef	0:d26c1b55cfca	646	/*
DieterGraef	0:d26c1b55cfca	647	* Phase 2: concat_p can be concatenated onto last_unsent->p
DieterGraef	0:d26c1b55cfca	648	*/
DieterGraef	0:d26c1b55cfca	649	if (concat_p != NULL) {
DieterGraef	0:d26c1b55cfca	650	LWIP_ASSERT("tcp_write: cannot concatenate when pcb->unsent is empty",
DieterGraef	0:d26c1b55cfca	651	(last_unsent != NULL));
DieterGraef	0:d26c1b55cfca	652	pbuf_cat(last_unsent->p, concat_p);
DieterGraef	0:d26c1b55cfca	653	last_unsent->len += concat_p->tot_len;
DieterGraef	0:d26c1b55cfca	654	#if TCP_CHECKSUM_ON_COPY
DieterGraef	0:d26c1b55cfca	655	if (concat_chksummed) {
DieterGraef	0:d26c1b55cfca	656	tcp_seg_add_chksum(concat_chksum, concat_chksummed, &last_unsent->chksum,
DieterGraef	0:d26c1b55cfca	657	&last_unsent->chksum_swapped);
DieterGraef	0:d26c1b55cfca	658	last_unsent->flags \|= TF_SEG_DATA_CHECKSUMMED;
DieterGraef	0:d26c1b55cfca	659	}
DieterGraef	0:d26c1b55cfca	660	#endif /* TCP_CHECKSUM_ON_COPY */
DieterGraef	0:d26c1b55cfca	661	}
DieterGraef	0:d26c1b55cfca	662
DieterGraef	0:d26c1b55cfca	663	/*
DieterGraef	0:d26c1b55cfca	664	* Phase 3: Append queue to pcb->unsent. Queue may be NULL, but that
DieterGraef	0:d26c1b55cfca	665	* is harmless
DieterGraef	0:d26c1b55cfca	666	*/
DieterGraef	0:d26c1b55cfca	667	if (last_unsent == NULL) {
DieterGraef	0:d26c1b55cfca	668	pcb->unsent = queue;
DieterGraef	0:d26c1b55cfca	669	} else {
DieterGraef	0:d26c1b55cfca	670	last_unsent->next = queue;
DieterGraef	0:d26c1b55cfca	671	}
DieterGraef	0:d26c1b55cfca	672
DieterGraef	0:d26c1b55cfca	673	/*
DieterGraef	0:d26c1b55cfca	674	* Finally update the pcb state.
DieterGraef	0:d26c1b55cfca	675	*/
DieterGraef	0:d26c1b55cfca	676	pcb->snd_lbb += len;
DieterGraef	0:d26c1b55cfca	677	pcb->snd_buf -= len;
DieterGraef	0:d26c1b55cfca	678	pcb->snd_queuelen = queuelen;
DieterGraef	0:d26c1b55cfca	679
DieterGraef	0:d26c1b55cfca	680	LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: %"S16_F" (after enqueued)\n",
DieterGraef	0:d26c1b55cfca	681	pcb->snd_queuelen));
DieterGraef	0:d26c1b55cfca	682	if (pcb->snd_queuelen != 0) {
DieterGraef	0:d26c1b55cfca	683	LWIP_ASSERT("tcp_write: valid queue length",
DieterGraef	0:d26c1b55cfca	684	pcb->unacked != NULL \|\| pcb->unsent != NULL);
DieterGraef	0:d26c1b55cfca	685	}
DieterGraef	0:d26c1b55cfca	686
DieterGraef	0:d26c1b55cfca	687	/* Set the PSH flag in the last segment that we enqueued. */
DieterGraef	0:d26c1b55cfca	688	if (seg != NULL && seg->tcphdr != NULL && ((apiflags & TCP_WRITE_FLAG_MORE)==0)) {
DieterGraef	0:d26c1b55cfca	689	TCPH_SET_FLAG(seg->tcphdr, TCP_PSH);
DieterGraef	0:d26c1b55cfca	690	}
DieterGraef	0:d26c1b55cfca	691
DieterGraef	0:d26c1b55cfca	692	return ERR_OK;
DieterGraef	0:d26c1b55cfca	693	memerr:
DieterGraef	0:d26c1b55cfca	694	pcb->flags \|= TF_NAGLEMEMERR;
DieterGraef	0:d26c1b55cfca	695	TCP_STATS_INC(tcp.memerr);
DieterGraef	0:d26c1b55cfca	696
DieterGraef	0:d26c1b55cfca	697	if (concat_p != NULL) {
DieterGraef	0:d26c1b55cfca	698	pbuf_free(concat_p);
DieterGraef	0:d26c1b55cfca	699	}
DieterGraef	0:d26c1b55cfca	700	if (queue != NULL) {
DieterGraef	0:d26c1b55cfca	701	tcp_segs_free(queue);
DieterGraef	0:d26c1b55cfca	702	}
DieterGraef	0:d26c1b55cfca	703	if (pcb->snd_queuelen != 0) {
DieterGraef	0:d26c1b55cfca	704	LWIP_ASSERT("tcp_write: valid queue length", pcb->unacked != NULL \|\|
DieterGraef	0:d26c1b55cfca	705	pcb->unsent != NULL);
DieterGraef	0:d26c1b55cfca	706	}
DieterGraef	0:d26c1b55cfca	707	LWIP_DEBUGF(TCP_QLEN_DEBUG \| LWIP_DBG_STATE, ("tcp_write: %"S16_F" (with mem err)\n", pcb->snd_queuelen));
DieterGraef	0:d26c1b55cfca	708	return ERR_MEM;
DieterGraef	0:d26c1b55cfca	709	}
DieterGraef	0:d26c1b55cfca	710
DieterGraef	0:d26c1b55cfca	711	/**
DieterGraef	0:d26c1b55cfca	712	* Enqueue TCP options for transmission.
DieterGraef	0:d26c1b55cfca	713	*
DieterGraef	0:d26c1b55cfca	714	* Called by tcp_connect(), tcp_listen_input(), and tcp_send_ctrl().
DieterGraef	0:d26c1b55cfca	715	*
DieterGraef	0:d26c1b55cfca	716	* @param pcb Protocol control block for the TCP connection.
DieterGraef	0:d26c1b55cfca	717	* @param flags TCP header flags to set in the outgoing segment.
DieterGraef	0:d26c1b55cfca	718	* @param optdata pointer to TCP options, or NULL.
DieterGraef	0:d26c1b55cfca	719	* @param optlen length of TCP options in bytes.
DieterGraef	0:d26c1b55cfca	720	*/
DieterGraef	0:d26c1b55cfca	721	err_t
DieterGraef	0:d26c1b55cfca	722	tcp_enqueue_flags(struct tcp_pcb *pcb, u8_t flags)
DieterGraef	0:d26c1b55cfca	723	{
DieterGraef	0:d26c1b55cfca	724	struct pbuf *p;
DieterGraef	0:d26c1b55cfca	725	struct tcp_seg *seg;
DieterGraef	0:d26c1b55cfca	726	u8_t optflags = 0;
DieterGraef	0:d26c1b55cfca	727	u8_t optlen = 0;
DieterGraef	0:d26c1b55cfca	728
DieterGraef	0:d26c1b55cfca	729	LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue_flags: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen));
DieterGraef	0:d26c1b55cfca	730
DieterGraef	0:d26c1b55cfca	731	LWIP_ASSERT("tcp_enqueue_flags: need either TCP_SYN or TCP_FIN in flags (programmer violates API)",
DieterGraef	0:d26c1b55cfca	732	(flags & (TCP_SYN \| TCP_FIN)) != 0);
DieterGraef	0:d26c1b55cfca	733
DieterGraef	0:d26c1b55cfca	734	/* check for configured max queuelen and possible overflow */
DieterGraef	0:d26c1b55cfca	735	if ((pcb->snd_queuelen >= TCP_SND_QUEUELEN) \|\| (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
DieterGraef	0:d26c1b55cfca	736	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| 3, ("tcp_enqueue_flags: too long queue %"U16_F" (max %"U16_F")\n",
DieterGraef	0:d26c1b55cfca	737	pcb->snd_queuelen, TCP_SND_QUEUELEN));
DieterGraef	0:d26c1b55cfca	738	TCP_STATS_INC(tcp.memerr);
DieterGraef	0:d26c1b55cfca	739	pcb->flags \|= TF_NAGLEMEMERR;
DieterGraef	0:d26c1b55cfca	740	return ERR_MEM;
DieterGraef	0:d26c1b55cfca	741	}
DieterGraef	0:d26c1b55cfca	742
DieterGraef	0:d26c1b55cfca	743	if (flags & TCP_SYN) {
DieterGraef	0:d26c1b55cfca	744	optflags = TF_SEG_OPTS_MSS;
DieterGraef	0:d26c1b55cfca	745	}
DieterGraef	0:d26c1b55cfca	746	#if LWIP_TCP_TIMESTAMPS
DieterGraef	0:d26c1b55cfca	747	if ((pcb->flags & TF_TIMESTAMP)) {
DieterGraef	0:d26c1b55cfca	748	optflags \|= TF_SEG_OPTS_TS;
DieterGraef	0:d26c1b55cfca	749	}
DieterGraef	0:d26c1b55cfca	750	#endif /* LWIP_TCP_TIMESTAMPS */
DieterGraef	0:d26c1b55cfca	751	optlen = LWIP_TCP_OPT_LENGTH(optflags);
DieterGraef	0:d26c1b55cfca	752
DieterGraef	0:d26c1b55cfca	753	/* tcp_enqueue_flags is always called with either SYN or FIN in flags.
DieterGraef	0:d26c1b55cfca	754	* We need one available snd_buf byte to do that.
DieterGraef	0:d26c1b55cfca	755	* This means we can't send FIN while snd_buf==0. A better fix would be to
DieterGraef	0:d26c1b55cfca	756	* not include SYN and FIN sequence numbers in the snd_buf count. */
DieterGraef	0:d26c1b55cfca	757	if (pcb->snd_buf == 0) {
DieterGraef	0:d26c1b55cfca	758	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| 3, ("tcp_enqueue_flags: no send buffer available\n"));
DieterGraef	0:d26c1b55cfca	759	TCP_STATS_INC(tcp.memerr);
DieterGraef	0:d26c1b55cfca	760	return ERR_MEM;
DieterGraef	0:d26c1b55cfca	761	}
DieterGraef	0:d26c1b55cfca	762
DieterGraef	0:d26c1b55cfca	763	/* Allocate pbuf with room for TCP header + options */
DieterGraef	0:d26c1b55cfca	764	if ((p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) {
DieterGraef	0:d26c1b55cfca	765	pcb->flags \|= TF_NAGLEMEMERR;
DieterGraef	0:d26c1b55cfca	766	TCP_STATS_INC(tcp.memerr);
DieterGraef	0:d26c1b55cfca	767	return ERR_MEM;
DieterGraef	0:d26c1b55cfca	768	}
DieterGraef	0:d26c1b55cfca	769	LWIP_ASSERT("tcp_enqueue_flags: check that first pbuf can hold optlen",
DieterGraef	0:d26c1b55cfca	770	(p->len >= optlen));
DieterGraef	0:d26c1b55cfca	771
DieterGraef	0:d26c1b55cfca	772	/* Allocate memory for tcp_seg, and fill in fields. */
DieterGraef	0:d26c1b55cfca	773	if ((seg = tcp_create_segment(pcb, p, flags, pcb->snd_lbb, optflags)) == NULL) {
DieterGraef	0:d26c1b55cfca	774	pcb->flags \|= TF_NAGLEMEMERR;
DieterGraef	0:d26c1b55cfca	775	TCP_STATS_INC(tcp.memerr);
DieterGraef	0:d26c1b55cfca	776	return ERR_MEM;
DieterGraef	0:d26c1b55cfca	777	}
DieterGraef	0:d26c1b55cfca	778	LWIP_ASSERT("seg->tcphdr not aligned", ((mem_ptr_t)seg->tcphdr % MEM_ALIGNMENT) == 0);
DieterGraef	0:d26c1b55cfca	779	LWIP_ASSERT("tcp_enqueue_flags: invalid segment length", seg->len == 0);
DieterGraef	0:d26c1b55cfca	780
DieterGraef	0:d26c1b55cfca	781	LWIP_DEBUGF(TCP_OUTPUT_DEBUG \| LWIP_DBG_TRACE,
DieterGraef	0:d26c1b55cfca	782	("tcp_enqueue_flags: queueing %"U32_F":%"U32_F" (0x%"X16_F")\n",
DieterGraef	0:d26c1b55cfca	783	ntohl(seg->tcphdr->seqno),
DieterGraef	0:d26c1b55cfca	784	ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg),
DieterGraef	0:d26c1b55cfca	785	(u16_t)flags));
DieterGraef	0:d26c1b55cfca	786
DieterGraef	0:d26c1b55cfca	787	/* Now append seg to pcb->unsent queue */
DieterGraef	0:d26c1b55cfca	788	if (pcb->unsent == NULL) {
DieterGraef	0:d26c1b55cfca	789	pcb->unsent = seg;
DieterGraef	0:d26c1b55cfca	790	} else {
DieterGraef	0:d26c1b55cfca	791	struct tcp_seg *useg;
DieterGraef	0:d26c1b55cfca	792	for (useg = pcb->unsent; useg->next != NULL; useg = useg->next);
DieterGraef	0:d26c1b55cfca	793	useg->next = seg;
DieterGraef	0:d26c1b55cfca	794	}
DieterGraef	0:d26c1b55cfca	795	#if TCP_OVERSIZE
DieterGraef	0:d26c1b55cfca	796	/* The new unsent tail has no space */
DieterGraef	0:d26c1b55cfca	797	pcb->unsent_oversize = 0;
DieterGraef	0:d26c1b55cfca	798	#endif /* TCP_OVERSIZE */
DieterGraef	0:d26c1b55cfca	799
DieterGraef	0:d26c1b55cfca	800	/* SYN and FIN bump the sequence number */
DieterGraef	0:d26c1b55cfca	801	if ((flags & TCP_SYN) \|\| (flags & TCP_FIN)) {
DieterGraef	0:d26c1b55cfca	802	pcb->snd_lbb++;
DieterGraef	0:d26c1b55cfca	803	/* optlen does not influence snd_buf */
DieterGraef	0:d26c1b55cfca	804	pcb->snd_buf--;
DieterGraef	0:d26c1b55cfca	805	}
DieterGraef	0:d26c1b55cfca	806	if (flags & TCP_FIN) {
DieterGraef	0:d26c1b55cfca	807	pcb->flags \|= TF_FIN;
DieterGraef	0:d26c1b55cfca	808	}
DieterGraef	0:d26c1b55cfca	809
DieterGraef	0:d26c1b55cfca	810	/* update number of segments on the queues */
DieterGraef	0:d26c1b55cfca	811	pcb->snd_queuelen += pbuf_clen(seg->p);
DieterGraef	0:d26c1b55cfca	812	LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue_flags: %"S16_F" (after enqueued)\n", pcb->snd_queuelen));
DieterGraef	0:d26c1b55cfca	813	if (pcb->snd_queuelen != 0) {
DieterGraef	0:d26c1b55cfca	814	LWIP_ASSERT("tcp_enqueue_flags: invalid queue length",
DieterGraef	0:d26c1b55cfca	815	pcb->unacked != NULL \|\| pcb->unsent != NULL);
DieterGraef	0:d26c1b55cfca	816	}
DieterGraef	0:d26c1b55cfca	817
DieterGraef	0:d26c1b55cfca	818	return ERR_OK;
DieterGraef	0:d26c1b55cfca	819	}
DieterGraef	0:d26c1b55cfca	820
DieterGraef	0:d26c1b55cfca	821	#if LWIP_TCP_TIMESTAMPS
DieterGraef	0:d26c1b55cfca	822	/* Build a timestamp option (12 bytes long) at the specified options pointer)
DieterGraef	0:d26c1b55cfca	823	*
DieterGraef	0:d26c1b55cfca	824	* @param pcb tcp_pcb
DieterGraef	0:d26c1b55cfca	825	* @param opts option pointer where to store the timestamp option
DieterGraef	0:d26c1b55cfca	826	*/
DieterGraef	0:d26c1b55cfca	827	static void
DieterGraef	0:d26c1b55cfca	828	tcp_build_timestamp_option(struct tcp_pcb pcb, u32_t opts)
DieterGraef	0:d26c1b55cfca	829	{
DieterGraef	0:d26c1b55cfca	830	/* Pad with two NOP options to make everything nicely aligned */
DieterGraef	0:d26c1b55cfca	831	opts[0] = PP_HTONL(0x0101080A);
DieterGraef	0:d26c1b55cfca	832	opts[1] = htonl(sys_now());
DieterGraef	0:d26c1b55cfca	833	opts[2] = htonl(pcb->ts_recent);
DieterGraef	0:d26c1b55cfca	834	}
DieterGraef	0:d26c1b55cfca	835	#endif
DieterGraef	0:d26c1b55cfca	836
DieterGraef	0:d26c1b55cfca	837	/** Send an ACK without data.
DieterGraef	0:d26c1b55cfca	838	*
DieterGraef	0:d26c1b55cfca	839	* @param pcb Protocol control block for the TCP connection to send the ACK
DieterGraef	0:d26c1b55cfca	840	*/
DieterGraef	0:d26c1b55cfca	841	err_t
DieterGraef	0:d26c1b55cfca	842	tcp_send_empty_ack(struct tcp_pcb *pcb)
DieterGraef	0:d26c1b55cfca	843	{
DieterGraef	0:d26c1b55cfca	844	struct pbuf *p;
DieterGraef	0:d26c1b55cfca	845	struct tcp_hdr *tcphdr;
DieterGraef	0:d26c1b55cfca	846	u8_t optlen = 0;
DieterGraef	0:d26c1b55cfca	847
DieterGraef	0:d26c1b55cfca	848	#if LWIP_TCP_TIMESTAMPS
DieterGraef	0:d26c1b55cfca	849	if (pcb->flags & TF_TIMESTAMP) {
DieterGraef	0:d26c1b55cfca	850	optlen = LWIP_TCP_OPT_LENGTH(TF_SEG_OPTS_TS);
DieterGraef	0:d26c1b55cfca	851	}
DieterGraef	0:d26c1b55cfca	852	#endif
DieterGraef	0:d26c1b55cfca	853
DieterGraef	0:d26c1b55cfca	854	p = tcp_output_alloc_header(pcb, optlen, 0, htonl(pcb->snd_nxt));
DieterGraef	0:d26c1b55cfca	855	if (p == NULL) {
DieterGraef	0:d26c1b55cfca	856	LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: (ACK) could not allocate pbuf\n"));
DieterGraef	0:d26c1b55cfca	857	return ERR_BUF;
DieterGraef	0:d26c1b55cfca	858	}
DieterGraef	0:d26c1b55cfca	859	tcphdr = (struct tcp_hdr *)p->payload;
DieterGraef	0:d26c1b55cfca	860	LWIP_DEBUGF(TCP_OUTPUT_DEBUG,
DieterGraef	0:d26c1b55cfca	861	("tcp_output: sending ACK for %"U32_F"\n", pcb->rcv_nxt));
DieterGraef	0:d26c1b55cfca	862	/* remove ACK flags from the PCB, as we send an empty ACK now */
DieterGraef	0:d26c1b55cfca	863	pcb->flags &= ~(TF_ACK_DELAY \| TF_ACK_NOW);
DieterGraef	0:d26c1b55cfca	864
DieterGraef	0:d26c1b55cfca	865	/* NB. MSS option is only sent on SYNs, so ignore it here */
DieterGraef	0:d26c1b55cfca	866	#if LWIP_TCP_TIMESTAMPS
DieterGraef	0:d26c1b55cfca	867	pcb->ts_lastacksent = pcb->rcv_nxt;
DieterGraef	0:d26c1b55cfca	868
DieterGraef	0:d26c1b55cfca	869	if (pcb->flags & TF_TIMESTAMP) {
DieterGraef	0:d26c1b55cfca	870	tcp_build_timestamp_option(pcb, (u32_t *)(tcphdr + 1));
DieterGraef	0:d26c1b55cfca	871	}
DieterGraef	0:d26c1b55cfca	872	#endif
DieterGraef	0:d26c1b55cfca	873
DieterGraef	0:d26c1b55cfca	874	#if CHECKSUM_GEN_TCP
DieterGraef	0:d26c1b55cfca	875	tcphdr->chksum = inet_chksum_pseudo(p, &(pcb->local_ip), &(pcb->remote_ip),
DieterGraef	0:d26c1b55cfca	876	IP_PROTO_TCP, p->tot_len);
DieterGraef	0:d26c1b55cfca	877	#endif
DieterGraef	0:d26c1b55cfca	878	#if LWIP_NETIF_HWADDRHINT
DieterGraef	0:d26c1b55cfca	879	ip_output_hinted(p, &(pcb->local_ip), &(pcb->remote_ip), pcb->ttl, pcb->tos,
DieterGraef	0:d26c1b55cfca	880	IP_PROTO_TCP, &(pcb->addr_hint));
DieterGraef	0:d26c1b55cfca	881	#else /* LWIP_NETIF_HWADDRHINT*/
DieterGraef	0:d26c1b55cfca	882	ip_output(p, &(pcb->local_ip), &(pcb->remote_ip), pcb->ttl, pcb->tos,
DieterGraef	0:d26c1b55cfca	883	IP_PROTO_TCP);
DieterGraef	0:d26c1b55cfca	884	#endif /* LWIP_NETIF_HWADDRHINT*/
DieterGraef	0:d26c1b55cfca	885	pbuf_free(p);
DieterGraef	0:d26c1b55cfca	886
DieterGraef	0:d26c1b55cfca	887	return ERR_OK;
DieterGraef	0:d26c1b55cfca	888	}
DieterGraef	0:d26c1b55cfca	889
DieterGraef	0:d26c1b55cfca	890	/**
DieterGraef	0:d26c1b55cfca	891	* Find out what we can send and send it
DieterGraef	0:d26c1b55cfca	892	*
DieterGraef	0:d26c1b55cfca	893	* @param pcb Protocol control block for the TCP connection to send data
DieterGraef	0:d26c1b55cfca	894	* @return ERR_OK if data has been sent or nothing to send
DieterGraef	0:d26c1b55cfca	895	* another err_t on error
DieterGraef	0:d26c1b55cfca	896	*/
DieterGraef	0:d26c1b55cfca	897	err_t
DieterGraef	0:d26c1b55cfca	898	tcp_output(struct tcp_pcb *pcb)
DieterGraef	0:d26c1b55cfca	899	{
DieterGraef	0:d26c1b55cfca	900	struct tcp_seg seg, useg;
DieterGraef	0:d26c1b55cfca	901	u32_t wnd, snd_nxt;
DieterGraef	0:d26c1b55cfca	902	#if TCP_CWND_DEBUG
DieterGraef	0:d26c1b55cfca	903	s16_t i = 0;
DieterGraef	0:d26c1b55cfca	904	#endif /* TCP_CWND_DEBUG */
DieterGraef	0:d26c1b55cfca	905
DieterGraef	0:d26c1b55cfca	906	/* pcb->state LISTEN not allowed here */
DieterGraef	0:d26c1b55cfca	907	LWIP_ASSERT("don't call tcp_output for listen-pcbs",
DieterGraef	0:d26c1b55cfca	908	pcb->state != LISTEN);
DieterGraef	0:d26c1b55cfca	909
DieterGraef	0:d26c1b55cfca	910	/* First, check if we are invoked by the TCP input processing
DieterGraef	0:d26c1b55cfca	911	code. If so, we do not output anything. Instead, we rely on the
DieterGraef	0:d26c1b55cfca	912	input processing code to call us when input processing is done
DieterGraef	0:d26c1b55cfca	913	with. */
DieterGraef	0:d26c1b55cfca	914	if (tcp_input_pcb == pcb) {
DieterGraef	0:d26c1b55cfca	915	return ERR_OK;
DieterGraef	0:d26c1b55cfca	916	}
DieterGraef	0:d26c1b55cfca	917
DieterGraef	0:d26c1b55cfca	918	wnd = LWIP_MIN(pcb->snd_wnd, pcb->cwnd);
DieterGraef	0:d26c1b55cfca	919
DieterGraef	0:d26c1b55cfca	920	seg = pcb->unsent;
DieterGraef	0:d26c1b55cfca	921
DieterGraef	0:d26c1b55cfca	922	/* If the TF_ACK_NOW flag is set and no data will be sent (either
DieterGraef	0:d26c1b55cfca	923	* because the ->unsent queue is empty or because the window does
DieterGraef	0:d26c1b55cfca	924	* not allow it), construct an empty ACK segment and send it.
DieterGraef	0:d26c1b55cfca	925	*
DieterGraef	0:d26c1b55cfca	926	* If data is to be sent, we will just piggyback the ACK (see below).
DieterGraef	0:d26c1b55cfca	927	*/
DieterGraef	0:d26c1b55cfca	928	if (pcb->flags & TF_ACK_NOW &&
DieterGraef	0:d26c1b55cfca	929	(seg == NULL \|\|
DieterGraef	0:d26c1b55cfca	930	ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len > wnd)) {
DieterGraef	0:d26c1b55cfca	931	return tcp_send_empty_ack(pcb);
DieterGraef	0:d26c1b55cfca	932	}
DieterGraef	0:d26c1b55cfca	933
DieterGraef	0:d26c1b55cfca	934	/* useg should point to last segment on unacked queue */
DieterGraef	0:d26c1b55cfca	935	useg = pcb->unacked;
DieterGraef	0:d26c1b55cfca	936	if (useg != NULL) {
DieterGraef	0:d26c1b55cfca	937	for (; useg->next != NULL; useg = useg->next);
DieterGraef	0:d26c1b55cfca	938	}
DieterGraef	0:d26c1b55cfca	939
DieterGraef	0:d26c1b55cfca	940	#if TCP_OUTPUT_DEBUG
DieterGraef	0:d26c1b55cfca	941	if (seg == NULL) {
DieterGraef	0:d26c1b55cfca	942	LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: nothing to send (%p)\n",
DieterGraef	0:d26c1b55cfca	943	(void*)pcb->unsent));
DieterGraef	0:d26c1b55cfca	944	}
DieterGraef	0:d26c1b55cfca	945	#endif /* TCP_OUTPUT_DEBUG */
DieterGraef	0:d26c1b55cfca	946	#if TCP_CWND_DEBUG
DieterGraef	0:d26c1b55cfca	947	if (seg == NULL) {
DieterGraef	0:d26c1b55cfca	948	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_output: snd_wnd %"U16_F
DieterGraef	0:d26c1b55cfca	949	", cwnd %"U16_F", wnd %"U32_F
DieterGraef	0:d26c1b55cfca	950	", seg == NULL, ack %"U32_F"\n",
DieterGraef	0:d26c1b55cfca	951	pcb->snd_wnd, pcb->cwnd, wnd, pcb->lastack));
DieterGraef	0:d26c1b55cfca	952	} else {
DieterGraef	0:d26c1b55cfca	953	LWIP_DEBUGF(TCP_CWND_DEBUG,
DieterGraef	0:d26c1b55cfca	954	("tcp_output: snd_wnd %"U16_F", cwnd %"U16_F", wnd %"U32_F
DieterGraef	0:d26c1b55cfca	955	", effwnd %"U32_F", seq %"U32_F", ack %"U32_F"\n",
DieterGraef	0:d26c1b55cfca	956	pcb->snd_wnd, pcb->cwnd, wnd,
DieterGraef	0:d26c1b55cfca	957	ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len,
DieterGraef	0:d26c1b55cfca	958	ntohl(seg->tcphdr->seqno), pcb->lastack));
DieterGraef	0:d26c1b55cfca	959	}
DieterGraef	0:d26c1b55cfca	960	#endif /* TCP_CWND_DEBUG */
DieterGraef	0:d26c1b55cfca	961	/* data available and window allows it to be sent? */
DieterGraef	0:d26c1b55cfca	962	while (seg != NULL &&
DieterGraef	0:d26c1b55cfca	963	ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len <= wnd) {
DieterGraef	0:d26c1b55cfca	964	LWIP_ASSERT("RST not expected here!",
DieterGraef	0:d26c1b55cfca	965	(TCPH_FLAGS(seg->tcphdr) & TCP_RST) == 0);
DieterGraef	0:d26c1b55cfca	966	/* Stop sending if the nagle algorithm would prevent it
DieterGraef	0:d26c1b55cfca	967	* Don't stop:
DieterGraef	0:d26c1b55cfca	968	* - if tcp_write had a memory error before (prevent delayed ACK timeout) or
DieterGraef	0:d26c1b55cfca	969	* - if FIN was already enqueued for this PCB (SYN is always alone in a segment -
DieterGraef	0:d26c1b55cfca	970	* either seg->next != NULL or pcb->unacked == NULL;
DieterGraef	0:d26c1b55cfca	971	* RST is no sent using tcp_write/tcp_output.
DieterGraef	0:d26c1b55cfca	972	*/
DieterGraef	0:d26c1b55cfca	973	if((tcp_do_output_nagle(pcb) == 0) &&
DieterGraef	0:d26c1b55cfca	974	((pcb->flags & (TF_NAGLEMEMERR \| TF_FIN)) == 0)){
DieterGraef	0:d26c1b55cfca	975	break;
DieterGraef	0:d26c1b55cfca	976	}
DieterGraef	0:d26c1b55cfca	977	#if TCP_CWND_DEBUG
DieterGraef	0:d26c1b55cfca	978	LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_output: snd_wnd %"U16_F", cwnd %"U16_F", wnd %"U32_F", effwnd %"U32_F", seq %"U32_F", ack %"U32_F", i %"S16_F"\n",
DieterGraef	0:d26c1b55cfca	979	pcb->snd_wnd, pcb->cwnd, wnd,
DieterGraef	0:d26c1b55cfca	980	ntohl(seg->tcphdr->seqno) + seg->len -
DieterGraef	0:d26c1b55cfca	981	pcb->lastack,
DieterGraef	0:d26c1b55cfca	982	ntohl(seg->tcphdr->seqno), pcb->lastack, i));
DieterGraef	0:d26c1b55cfca	983	++i;
DieterGraef	0:d26c1b55cfca	984	#endif /* TCP_CWND_DEBUG */
DieterGraef	0:d26c1b55cfca	985
DieterGraef	0:d26c1b55cfca	986	pcb->unsent = seg->next;
DieterGraef	0:d26c1b55cfca	987
DieterGraef	0:d26c1b55cfca	988	if (pcb->state != SYN_SENT) {
DieterGraef	0:d26c1b55cfca	989	TCPH_SET_FLAG(seg->tcphdr, TCP_ACK);
DieterGraef	0:d26c1b55cfca	990	pcb->flags &= ~(TF_ACK_DELAY \| TF_ACK_NOW);
DieterGraef	0:d26c1b55cfca	991	}
DieterGraef	0:d26c1b55cfca	992
DieterGraef	0:d26c1b55cfca	993	tcp_output_segment(seg, pcb);
DieterGraef	0:d26c1b55cfca	994	snd_nxt = ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg);
DieterGraef	0:d26c1b55cfca	995	if (TCP_SEQ_LT(pcb->snd_nxt, snd_nxt)) {
DieterGraef	0:d26c1b55cfca	996	pcb->snd_nxt = snd_nxt;
DieterGraef	0:d26c1b55cfca	997	}
DieterGraef	0:d26c1b55cfca	998	/* put segment on unacknowledged list if length > 0 */
DieterGraef	0:d26c1b55cfca	999	if (TCP_TCPLEN(seg) > 0) {
DieterGraef	0:d26c1b55cfca	1000	seg->next = NULL;
DieterGraef	0:d26c1b55cfca	1001	/* unacked list is empty? */
DieterGraef	0:d26c1b55cfca	1002	if (pcb->unacked == NULL) {
DieterGraef	0:d26c1b55cfca	1003	pcb->unacked = seg;
DieterGraef	0:d26c1b55cfca	1004	useg = seg;
DieterGraef	0:d26c1b55cfca	1005	/* unacked list is not empty? */
DieterGraef	0:d26c1b55cfca	1006	} else {
DieterGraef	0:d26c1b55cfca	1007	/* In the case of fast retransmit, the packet should not go to the tail
DieterGraef	0:d26c1b55cfca	1008	* of the unacked queue, but rather somewhere before it. We need to check for
DieterGraef	0:d26c1b55cfca	1009	* this case. -STJ Jul 27, 2004 */
DieterGraef	0:d26c1b55cfca	1010	if (TCP_SEQ_LT(ntohl(seg->tcphdr->seqno), ntohl(useg->tcphdr->seqno))) {
DieterGraef	0:d26c1b55cfca	1011	/* add segment to before tail of unacked list, keeping the list sorted */
DieterGraef	0:d26c1b55cfca	1012	struct tcp_seg **cur_seg = &(pcb->unacked);
DieterGraef	0:d26c1b55cfca	1013	while (*cur_seg &&
DieterGraef	0:d26c1b55cfca	1014	TCP_SEQ_LT(ntohl((*cur_seg)->tcphdr->seqno), ntohl(seg->tcphdr->seqno))) {
DieterGraef	0:d26c1b55cfca	1015	cur_seg = &((*cur_seg)->next );
DieterGraef	0:d26c1b55cfca	1016	}
DieterGraef	0:d26c1b55cfca	1017	seg->next = (*cur_seg);
DieterGraef	0:d26c1b55cfca	1018	(*cur_seg) = seg;
DieterGraef	0:d26c1b55cfca	1019	} else {
DieterGraef	0:d26c1b55cfca	1020	/* add segment to tail of unacked list */
DieterGraef	0:d26c1b55cfca	1021	useg->next = seg;
DieterGraef	0:d26c1b55cfca	1022	useg = useg->next;
DieterGraef	0:d26c1b55cfca	1023	}
DieterGraef	0:d26c1b55cfca	1024	}
DieterGraef	0:d26c1b55cfca	1025	/* do not queue empty segments on the unacked list */
DieterGraef	0:d26c1b55cfca	1026	} else {
DieterGraef	0:d26c1b55cfca	1027	tcp_seg_free(seg);
DieterGraef	0:d26c1b55cfca	1028	}
DieterGraef	0:d26c1b55cfca	1029	seg = pcb->unsent;
DieterGraef	0:d26c1b55cfca	1030	}
DieterGraef	0:d26c1b55cfca	1031	#if TCP_OVERSIZE
DieterGraef	0:d26c1b55cfca	1032	if (pcb->unsent == NULL) {
DieterGraef	0:d26c1b55cfca	1033	/* last unsent has been removed, reset unsent_oversize */
DieterGraef	0:d26c1b55cfca	1034	pcb->unsent_oversize = 0;
DieterGraef	0:d26c1b55cfca	1035	}
DieterGraef	0:d26c1b55cfca	1036	#endif /* TCP_OVERSIZE */
DieterGraef	0:d26c1b55cfca	1037
DieterGraef	0:d26c1b55cfca	1038	pcb->flags &= ~TF_NAGLEMEMERR;
DieterGraef	0:d26c1b55cfca	1039	return ERR_OK;
DieterGraef	0:d26c1b55cfca	1040	}
DieterGraef	0:d26c1b55cfca	1041
DieterGraef	0:d26c1b55cfca	1042	/**
DieterGraef	0:d26c1b55cfca	1043	* Called by tcp_output() to actually send a TCP segment over IP.
DieterGraef	0:d26c1b55cfca	1044	*
DieterGraef	0:d26c1b55cfca	1045	* @param seg the tcp_seg to send
DieterGraef	0:d26c1b55cfca	1046	* @param pcb the tcp_pcb for the TCP connection used to send the segment
DieterGraef	0:d26c1b55cfca	1047	*/
DieterGraef	0:d26c1b55cfca	1048	static void
DieterGraef	0:d26c1b55cfca	1049	tcp_output_segment(struct tcp_seg seg, struct tcp_pcb pcb)
DieterGraef	0:d26c1b55cfca	1050	{
DieterGraef	0:d26c1b55cfca	1051	u16_t len;
DieterGraef	0:d26c1b55cfca	1052	struct netif *netif;
DieterGraef	0:d26c1b55cfca	1053	u32_t *opts;
DieterGraef	0:d26c1b55cfca	1054
DieterGraef	0:d26c1b55cfca	1055	/** @bug Exclude retransmitted segments from this count. */
DieterGraef	0:d26c1b55cfca	1056	snmp_inc_tcpoutsegs();
DieterGraef	0:d26c1b55cfca	1057
DieterGraef	0:d26c1b55cfca	1058	/* The TCP header has already been constructed, but the ackno and
DieterGraef	0:d26c1b55cfca	1059	wnd fields remain. */
DieterGraef	0:d26c1b55cfca	1060	seg->tcphdr->ackno = htonl(pcb->rcv_nxt);
DieterGraef	0:d26c1b55cfca	1061
DieterGraef	0:d26c1b55cfca	1062	/* advertise our receive window size in this TCP segment */
DieterGraef	0:d26c1b55cfca	1063	seg->tcphdr->wnd = htons(pcb->rcv_ann_wnd);
DieterGraef	0:d26c1b55cfca	1064
DieterGraef	0:d26c1b55cfca	1065	pcb->rcv_ann_right_edge = pcb->rcv_nxt + pcb->rcv_ann_wnd;
DieterGraef	0:d26c1b55cfca	1066
DieterGraef	0:d26c1b55cfca	1067	/* Add any requested options. NB MSS option is only set on SYN
DieterGraef	0:d26c1b55cfca	1068	packets, so ignore it here */
DieterGraef	0:d26c1b55cfca	1069	opts = (u32_t )(void )(seg->tcphdr + 1);
DieterGraef	0:d26c1b55cfca	1070	if (seg->flags & TF_SEG_OPTS_MSS) {
DieterGraef	0:d26c1b55cfca	1071	u16_t mss;
DieterGraef	0:d26c1b55cfca	1072	#if TCP_CALCULATE_EFF_SEND_MSS
DieterGraef	0:d26c1b55cfca	1073	mss = tcp_eff_send_mss(TCP_MSS, &pcb->remote_ip);
DieterGraef	0:d26c1b55cfca	1074	#else /* TCP_CALCULATE_EFF_SEND_MSS */
DieterGraef	0:d26c1b55cfca	1075	mss = TCP_MSS;
DieterGraef	0:d26c1b55cfca	1076	#endif /* TCP_CALCULATE_EFF_SEND_MSS */
DieterGraef	0:d26c1b55cfca	1077	*opts = TCP_BUILD_MSS_OPTION(mss);
DieterGraef	0:d26c1b55cfca	1078	opts += 1;
DieterGraef	0:d26c1b55cfca	1079	}
DieterGraef	0:d26c1b55cfca	1080	#if LWIP_TCP_TIMESTAMPS
DieterGraef	0:d26c1b55cfca	1081	pcb->ts_lastacksent = pcb->rcv_nxt;
DieterGraef	0:d26c1b55cfca	1082
DieterGraef	0:d26c1b55cfca	1083	if (seg->flags & TF_SEG_OPTS_TS) {
DieterGraef	0:d26c1b55cfca	1084	tcp_build_timestamp_option(pcb, opts);
DieterGraef	0:d26c1b55cfca	1085	opts += 3;
DieterGraef	0:d26c1b55cfca	1086	}
DieterGraef	0:d26c1b55cfca	1087	#endif
DieterGraef	0:d26c1b55cfca	1088
DieterGraef	0:d26c1b55cfca	1089	/* Set retransmission timer running if it is not currently enabled
DieterGraef	0:d26c1b55cfca	1090	This must be set before checking the route. */
DieterGraef	0:d26c1b55cfca	1091	if (pcb->rtime == -1) {
DieterGraef	0:d26c1b55cfca	1092	pcb->rtime = 0;
DieterGraef	0:d26c1b55cfca	1093	}
DieterGraef	0:d26c1b55cfca	1094
DieterGraef	0:d26c1b55cfca	1095	/* If we don't have a local IP address, we get one by
DieterGraef	0:d26c1b55cfca	1096	calling ip_route(). */
DieterGraef	0:d26c1b55cfca	1097	if (ip_addr_isany(&(pcb->local_ip))) {
DieterGraef	0:d26c1b55cfca	1098	netif = ip_route(&(pcb->remote_ip));
DieterGraef	0:d26c1b55cfca	1099	if (netif == NULL) {
DieterGraef	0:d26c1b55cfca	1100	return;
DieterGraef	0:d26c1b55cfca	1101	}
DieterGraef	0:d26c1b55cfca	1102	ip_addr_copy(pcb->local_ip, netif->ip_addr);
DieterGraef	0:d26c1b55cfca	1103	}
DieterGraef	0:d26c1b55cfca	1104
DieterGraef	0:d26c1b55cfca	1105	if (pcb->rttest == 0) {
DieterGraef	0:d26c1b55cfca	1106	pcb->rttest = tcp_ticks;
DieterGraef	0:d26c1b55cfca	1107	pcb->rtseq = ntohl(seg->tcphdr->seqno);
DieterGraef	0:d26c1b55cfca	1108
DieterGraef	0:d26c1b55cfca	1109	LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_output_segment: rtseq %"U32_F"\n", pcb->rtseq));
DieterGraef	0:d26c1b55cfca	1110	}
DieterGraef	0:d26c1b55cfca	1111	LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output_segment: %"U32_F":%"U32_F"\n",
DieterGraef	0:d26c1b55cfca	1112	htonl(seg->tcphdr->seqno), htonl(seg->tcphdr->seqno) +
DieterGraef	0:d26c1b55cfca	1113	seg->len));
DieterGraef	0:d26c1b55cfca	1114
DieterGraef	0:d26c1b55cfca	1115	len = (u16_t)((u8_t )seg->tcphdr - (u8_t )seg->p->payload);
DieterGraef	0:d26c1b55cfca	1116
DieterGraef	0:d26c1b55cfca	1117	seg->p->len -= len;
DieterGraef	0:d26c1b55cfca	1118	seg->p->tot_len -= len;
DieterGraef	0:d26c1b55cfca	1119
DieterGraef	0:d26c1b55cfca	1120	seg->p->payload = seg->tcphdr;
DieterGraef	0:d26c1b55cfca	1121
DieterGraef	0:d26c1b55cfca	1122	seg->tcphdr->chksum = 0;
DieterGraef	0:d26c1b55cfca	1123	#if CHECKSUM_GEN_TCP
DieterGraef	0:d26c1b55cfca	1124	#if TCP_CHECKSUM_ON_COPY
DieterGraef	0:d26c1b55cfca	1125	{
DieterGraef	0:d26c1b55cfca	1126	u32_t acc;
DieterGraef	0:d26c1b55cfca	1127	#if TCP_CHECKSUM_ON_COPY_SANITY_CHECK
DieterGraef	0:d26c1b55cfca	1128	u16_t chksum_slow = inet_chksum_pseudo(seg->p, &(pcb->local_ip),
DieterGraef	0:d26c1b55cfca	1129	&(pcb->remote_ip),
DieterGraef	0:d26c1b55cfca	1130	IP_PROTO_TCP, seg->p->tot_len);
DieterGraef	0:d26c1b55cfca	1131	#endif /* TCP_CHECKSUM_ON_COPY_SANITY_CHECK */
DieterGraef	0:d26c1b55cfca	1132	if ((seg->flags & TF_SEG_DATA_CHECKSUMMED) == 0) {
DieterGraef	0:d26c1b55cfca	1133	LWIP_ASSERT("data included but not checksummed",
DieterGraef	0:d26c1b55cfca	1134	seg->p->tot_len == (TCPH_HDRLEN(seg->tcphdr) * 4));
DieterGraef	0:d26c1b55cfca	1135	}
DieterGraef	0:d26c1b55cfca	1136
DieterGraef	0:d26c1b55cfca	1137	/* rebuild TCP header checksum (TCP header changes for retransmissions!) */
DieterGraef	0:d26c1b55cfca	1138	acc = inet_chksum_pseudo_partial(seg->p, &(pcb->local_ip),
DieterGraef	0:d26c1b55cfca	1139	&(pcb->remote_ip),
DieterGraef	0:d26c1b55cfca	1140	IP_PROTO_TCP, seg->p->tot_len, TCPH_HDRLEN(seg->tcphdr) * 4);
DieterGraef	0:d26c1b55cfca	1141	/* add payload checksum */
DieterGraef	0:d26c1b55cfca	1142	if (seg->chksum_swapped) {
DieterGraef	0:d26c1b55cfca	1143	seg->chksum = SWAP_BYTES_IN_WORD(seg->chksum);
DieterGraef	0:d26c1b55cfca	1144	seg->chksum_swapped = 0;
DieterGraef	0:d26c1b55cfca	1145	}
DieterGraef	0:d26c1b55cfca	1146	acc += (u16_t)~(seg->chksum);
DieterGraef	0:d26c1b55cfca	1147	seg->tcphdr->chksum = FOLD_U32T(acc);
DieterGraef	0:d26c1b55cfca	1148	#if TCP_CHECKSUM_ON_COPY_SANITY_CHECK
DieterGraef	0:d26c1b55cfca	1149	if (chksum_slow != seg->tcphdr->chksum) {
DieterGraef	0:d26c1b55cfca	1150	LWIP_DEBUGF(TCP_DEBUG \| LWIP_DBG_LEVEL_WARNING,
DieterGraef	0:d26c1b55cfca	1151	("tcp_output_segment: calculated checksum is %"X16_F" instead of %"X16_F"\n",
DieterGraef	0:d26c1b55cfca	1152	seg->tcphdr->chksum, chksum_slow));
DieterGraef	0:d26c1b55cfca	1153	seg->tcphdr->chksum = chksum_slow;
DieterGraef	0:d26c1b55cfca	1154	}
DieterGraef	0:d26c1b55cfca	1155	#endif /* TCP_CHECKSUM_ON_COPY_SANITY_CHECK */
DieterGraef	0:d26c1b55cfca	1156	}
DieterGraef	0:d26c1b55cfca	1157	#else /* TCP_CHECKSUM_ON_COPY */
DieterGraef	0:d26c1b55cfca	1158	seg->tcphdr->chksum = inet_chksum_pseudo(seg->p, &(pcb->local_ip),
DieterGraef	0:d26c1b55cfca	1159	&(pcb->remote_ip),
DieterGraef	0:d26c1b55cfca	1160	IP_PROTO_TCP, seg->p->tot_len);
DieterGraef	0:d26c1b55cfca	1161	#endif /* TCP_CHECKSUM_ON_COPY */
DieterGraef	0:d26c1b55cfca	1162	#endif /* CHECKSUM_GEN_TCP */
DieterGraef	0:d26c1b55cfca	1163	TCP_STATS_INC(tcp.xmit);
DieterGraef	0:d26c1b55cfca	1164
DieterGraef	0:d26c1b55cfca	1165	#if LWIP_NETIF_HWADDRHINT
DieterGraef	0:d26c1b55cfca	1166	ip_output_hinted(seg->p, &(pcb->local_ip), &(pcb->remote_ip), pcb->ttl, pcb->tos,
DieterGraef	0:d26c1b55cfca	1167	IP_PROTO_TCP, &(pcb->addr_hint));
DieterGraef	0:d26c1b55cfca	1168	#else /* LWIP_NETIF_HWADDRHINT*/
DieterGraef	0:d26c1b55cfca	1169	ip_output(seg->p, &(pcb->local_ip), &(pcb->remote_ip), pcb->ttl, pcb->tos,
DieterGraef	0:d26c1b55cfca	1170	IP_PROTO_TCP);
DieterGraef	0:d26c1b55cfca	1171	#endif /* LWIP_NETIF_HWADDRHINT*/
DieterGraef	0:d26c1b55cfca	1172	}
DieterGraef	0:d26c1b55cfca	1173
DieterGraef	0:d26c1b55cfca	1174	/**
DieterGraef	0:d26c1b55cfca	1175	* Send a TCP RESET packet (empty segment with RST flag set) either to
DieterGraef	0:d26c1b55cfca	1176	* abort a connection or to show that there is no matching local connection
DieterGraef	0:d26c1b55cfca	1177	* for a received segment.
DieterGraef	0:d26c1b55cfca	1178	*
DieterGraef	0:d26c1b55cfca	1179	* Called by tcp_abort() (to abort a local connection), tcp_input() (if no
DieterGraef	0:d26c1b55cfca	1180	* matching local pcb was found), tcp_listen_input() (if incoming segment
DieterGraef	0:d26c1b55cfca	1181	* has ACK flag set) and tcp_process() (received segment in the wrong state)
DieterGraef	0:d26c1b55cfca	1182	*
DieterGraef	0:d26c1b55cfca	1183	* Since a RST segment is in most cases not sent for an active connection,
DieterGraef	0:d26c1b55cfca	1184	* tcp_rst() has a number of arguments that are taken from a tcp_pcb for
DieterGraef	0:d26c1b55cfca	1185	* most other segment output functions.
DieterGraef	0:d26c1b55cfca	1186	*
DieterGraef	0:d26c1b55cfca	1187	* @param seqno the sequence number to use for the outgoing segment
DieterGraef	0:d26c1b55cfca	1188	* @param ackno the acknowledge number to use for the outgoing segment
DieterGraef	0:d26c1b55cfca	1189	* @param local_ip the local IP address to send the segment from
DieterGraef	0:d26c1b55cfca	1190	* @param remote_ip the remote IP address to send the segment to
DieterGraef	0:d26c1b55cfca	1191	* @param local_port the local TCP port to send the segment from
DieterGraef	0:d26c1b55cfca	1192	* @param remote_port the remote TCP port to send the segment to
DieterGraef	0:d26c1b55cfca	1193	*/
DieterGraef	0:d26c1b55cfca	1194	void
DieterGraef	0:d26c1b55cfca	1195	tcp_rst(u32_t seqno, u32_t ackno,
DieterGraef	0:d26c1b55cfca	1196	ip_addr_t local_ip, ip_addr_t remote_ip,
DieterGraef	0:d26c1b55cfca	1197	u16_t local_port, u16_t remote_port)
DieterGraef	0:d26c1b55cfca	1198	{
DieterGraef	0:d26c1b55cfca	1199	struct pbuf *p;
DieterGraef	0:d26c1b55cfca	1200	struct tcp_hdr *tcphdr;
DieterGraef	0:d26c1b55cfca	1201	p = pbuf_alloc(PBUF_IP, TCP_HLEN, PBUF_RAM);
DieterGraef	0:d26c1b55cfca	1202	if (p == NULL) {
DieterGraef	0:d26c1b55cfca	1203	LWIP_DEBUGF(TCP_DEBUG, ("tcp_rst: could not allocate memory for pbuf\n"));
DieterGraef	0:d26c1b55cfca	1204	return;
DieterGraef	0:d26c1b55cfca	1205	}
DieterGraef	0:d26c1b55cfca	1206	LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr",
DieterGraef	0:d26c1b55cfca	1207	(p->len >= sizeof(struct tcp_hdr)));
DieterGraef	0:d26c1b55cfca	1208
DieterGraef	0:d26c1b55cfca	1209	tcphdr = (struct tcp_hdr *)p->payload;
DieterGraef	0:d26c1b55cfca	1210	tcphdr->src = htons(local_port);
DieterGraef	0:d26c1b55cfca	1211	tcphdr->dest = htons(remote_port);
DieterGraef	0:d26c1b55cfca	1212	tcphdr->seqno = htonl(seqno);
DieterGraef	0:d26c1b55cfca	1213	tcphdr->ackno = htonl(ackno);
DieterGraef	0:d26c1b55cfca	1214	TCPH_HDRLEN_FLAGS_SET(tcphdr, TCP_HLEN/4, TCP_RST \| TCP_ACK);
DieterGraef	0:d26c1b55cfca	1215	tcphdr->wnd = PP_HTONS(TCP_WND);
DieterGraef	0:d26c1b55cfca	1216	tcphdr->chksum = 0;
DieterGraef	0:d26c1b55cfca	1217	tcphdr->urgp = 0;
DieterGraef	0:d26c1b55cfca	1218
DieterGraef	0:d26c1b55cfca	1219	#if CHECKSUM_GEN_TCP
DieterGraef	0:d26c1b55cfca	1220	tcphdr->chksum = inet_chksum_pseudo(p, local_ip, remote_ip,
DieterGraef	0:d26c1b55cfca	1221	IP_PROTO_TCP, p->tot_len);
DieterGraef	0:d26c1b55cfca	1222	#endif
DieterGraef	0:d26c1b55cfca	1223	TCP_STATS_INC(tcp.xmit);
DieterGraef	0:d26c1b55cfca	1224	snmp_inc_tcpoutrsts();
DieterGraef	0:d26c1b55cfca	1225	/* Send output with hardcoded TTL since we have no access to the pcb */
DieterGraef	0:d26c1b55cfca	1226	ip_output(p, local_ip, remote_ip, TCP_TTL, 0, IP_PROTO_TCP);
DieterGraef	0:d26c1b55cfca	1227	pbuf_free(p);
DieterGraef	0:d26c1b55cfca	1228	LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_rst: seqno %"U32_F" ackno %"U32_F".\n", seqno, ackno));
DieterGraef	0:d26c1b55cfca	1229	}
DieterGraef	0:d26c1b55cfca	1230
DieterGraef	0:d26c1b55cfca	1231	/**
DieterGraef	0:d26c1b55cfca	1232	* Requeue all unacked segments for retransmission
DieterGraef	0:d26c1b55cfca	1233	*
DieterGraef	0:d26c1b55cfca	1234	* Called by tcp_slowtmr() for slow retransmission.
DieterGraef	0:d26c1b55cfca	1235	*
DieterGraef	0:d26c1b55cfca	1236	* @param pcb the tcp_pcb for which to re-enqueue all unacked segments
DieterGraef	0:d26c1b55cfca	1237	*/
DieterGraef	0:d26c1b55cfca	1238	void
DieterGraef	0:d26c1b55cfca	1239	tcp_rexmit_rto(struct tcp_pcb *pcb)
DieterGraef	0:d26c1b55cfca	1240	{
DieterGraef	0:d26c1b55cfca	1241	struct tcp_seg *seg;
DieterGraef	0:d26c1b55cfca	1242
DieterGraef	0:d26c1b55cfca	1243	if (pcb->unacked == NULL) {
DieterGraef	0:d26c1b55cfca	1244	return;
DieterGraef	0:d26c1b55cfca	1245	}
DieterGraef	0:d26c1b55cfca	1246
DieterGraef	0:d26c1b55cfca	1247	/* Move all unacked segments to the head of the unsent queue */
DieterGraef	0:d26c1b55cfca	1248	for (seg = pcb->unacked; seg->next != NULL; seg = seg->next);
DieterGraef	0:d26c1b55cfca	1249	/* concatenate unsent queue after unacked queue */
DieterGraef	0:d26c1b55cfca	1250	seg->next = pcb->unsent;
DieterGraef	0:d26c1b55cfca	1251	/* unsent queue is the concatenated queue (of unacked, unsent) */
DieterGraef	0:d26c1b55cfca	1252	pcb->unsent = pcb->unacked;
DieterGraef	0:d26c1b55cfca	1253	/* unacked queue is now empty */
DieterGraef	0:d26c1b55cfca	1254	pcb->unacked = NULL;
DieterGraef	0:d26c1b55cfca	1255	/* last unsent hasn't changed, no need to reset unsent_oversize */
DieterGraef	0:d26c1b55cfca	1256
DieterGraef	0:d26c1b55cfca	1257	/* increment number of retransmissions */
DieterGraef	0:d26c1b55cfca	1258	++pcb->nrtx;
DieterGraef	0:d26c1b55cfca	1259
DieterGraef	0:d26c1b55cfca	1260	/* Don't take any RTT measurements after retransmitting. */
DieterGraef	0:d26c1b55cfca	1261	pcb->rttest = 0;
DieterGraef	0:d26c1b55cfca	1262
DieterGraef	0:d26c1b55cfca	1263	/* Do the actual retransmission */
DieterGraef	0:d26c1b55cfca	1264	tcp_output(pcb);
DieterGraef	0:d26c1b55cfca	1265	}
DieterGraef	0:d26c1b55cfca	1266
DieterGraef	0:d26c1b55cfca	1267	/**
DieterGraef	0:d26c1b55cfca	1268	* Requeue the first unacked segment for retransmission
DieterGraef	0:d26c1b55cfca	1269	*
DieterGraef	0:d26c1b55cfca	1270	* Called by tcp_receive() for fast retramsmit.
DieterGraef	0:d26c1b55cfca	1271	*
DieterGraef	0:d26c1b55cfca	1272	* @param pcb the tcp_pcb for which to retransmit the first unacked segment
DieterGraef	0:d26c1b55cfca	1273	*/
DieterGraef	0:d26c1b55cfca	1274	void
DieterGraef	0:d26c1b55cfca	1275	tcp_rexmit(struct tcp_pcb *pcb)
DieterGraef	0:d26c1b55cfca	1276	{
DieterGraef	0:d26c1b55cfca	1277	struct tcp_seg *seg;
DieterGraef	0:d26c1b55cfca	1278	struct tcp_seg **cur_seg;
DieterGraef	0:d26c1b55cfca	1279
DieterGraef	0:d26c1b55cfca	1280	if (pcb->unacked == NULL) {
DieterGraef	0:d26c1b55cfca	1281	return;
DieterGraef	0:d26c1b55cfca	1282	}
DieterGraef	0:d26c1b55cfca	1283
DieterGraef	0:d26c1b55cfca	1284	/* Move the first unacked segment to the unsent queue */
DieterGraef	0:d26c1b55cfca	1285	/* Keep the unsent queue sorted. */
DieterGraef	0:d26c1b55cfca	1286	seg = pcb->unacked;
DieterGraef	0:d26c1b55cfca	1287	pcb->unacked = seg->next;
DieterGraef	0:d26c1b55cfca	1288
DieterGraef	0:d26c1b55cfca	1289	cur_seg = &(pcb->unsent);
DieterGraef	0:d26c1b55cfca	1290	while (*cur_seg &&
DieterGraef	0:d26c1b55cfca	1291	TCP_SEQ_LT(ntohl((*cur_seg)->tcphdr->seqno), ntohl(seg->tcphdr->seqno))) {
DieterGraef	0:d26c1b55cfca	1292	cur_seg = &((*cur_seg)->next );
DieterGraef	0:d26c1b55cfca	1293	}
DieterGraef	0:d26c1b55cfca	1294	seg->next = *cur_seg;
DieterGraef	0:d26c1b55cfca	1295	*cur_seg = seg;
DieterGraef	0:d26c1b55cfca	1296	#if TCP_OVERSIZE
DieterGraef	0:d26c1b55cfca	1297	if (seg->next == NULL) {
DieterGraef	0:d26c1b55cfca	1298	/* the retransmitted segment is last in unsent, so reset unsent_oversize */
DieterGraef	0:d26c1b55cfca	1299	pcb->unsent_oversize = 0;
DieterGraef	0:d26c1b55cfca	1300	}
DieterGraef	0:d26c1b55cfca	1301	#endif /* TCP_OVERSIZE */
DieterGraef	0:d26c1b55cfca	1302
DieterGraef	0:d26c1b55cfca	1303	++pcb->nrtx;
DieterGraef	0:d26c1b55cfca	1304
DieterGraef	0:d26c1b55cfca	1305	/* Don't take any rtt measurements after retransmitting. */
DieterGraef	0:d26c1b55cfca	1306	pcb->rttest = 0;
DieterGraef	0:d26c1b55cfca	1307
DieterGraef	0:d26c1b55cfca	1308	/* Do the actual retransmission. */
DieterGraef	0:d26c1b55cfca	1309	snmp_inc_tcpretranssegs();
DieterGraef	0:d26c1b55cfca	1310	/* No need to call tcp_output: we are always called from tcp_input()
DieterGraef	0:d26c1b55cfca	1311	and thus tcp_output directly returns. */
DieterGraef	0:d26c1b55cfca	1312	}
DieterGraef	0:d26c1b55cfca	1313
DieterGraef	0:d26c1b55cfca	1314
DieterGraef	0:d26c1b55cfca	1315	/**
DieterGraef	0:d26c1b55cfca	1316	* Handle retransmission after three dupacks received
DieterGraef	0:d26c1b55cfca	1317	*
DieterGraef	0:d26c1b55cfca	1318	* @param pcb the tcp_pcb for which to retransmit the first unacked segment
DieterGraef	0:d26c1b55cfca	1319	*/
DieterGraef	0:d26c1b55cfca	1320	void
DieterGraef	0:d26c1b55cfca	1321	tcp_rexmit_fast(struct tcp_pcb *pcb)
DieterGraef	0:d26c1b55cfca	1322	{
DieterGraef	0:d26c1b55cfca	1323	if (pcb->unacked != NULL && !(pcb->flags & TF_INFR)) {
DieterGraef	0:d26c1b55cfca	1324	/* This is fast retransmit. Retransmit the first unacked segment. */
DieterGraef	0:d26c1b55cfca	1325	LWIP_DEBUGF(TCP_FR_DEBUG,
DieterGraef	0:d26c1b55cfca	1326	("tcp_receive: dupacks %"U16_F" (%"U32_F
DieterGraef	0:d26c1b55cfca	1327	"), fast retransmit %"U32_F"\n",
DieterGraef	0:d26c1b55cfca	1328	(u16_t)pcb->dupacks, pcb->lastack,
DieterGraef	0:d26c1b55cfca	1329	ntohl(pcb->unacked->tcphdr->seqno)));
DieterGraef	0:d26c1b55cfca	1330	tcp_rexmit(pcb);
DieterGraef	0:d26c1b55cfca	1331
DieterGraef	0:d26c1b55cfca	1332	/* Set ssthresh to half of the minimum of the current
DieterGraef	0:d26c1b55cfca	1333	* cwnd and the advertised window */
DieterGraef	0:d26c1b55cfca	1334	if (pcb->cwnd > pcb->snd_wnd) {
DieterGraef	0:d26c1b55cfca	1335	pcb->ssthresh = pcb->snd_wnd / 2;
DieterGraef	0:d26c1b55cfca	1336	} else {
DieterGraef	0:d26c1b55cfca	1337	pcb->ssthresh = pcb->cwnd / 2;
DieterGraef	0:d26c1b55cfca	1338	}
DieterGraef	0:d26c1b55cfca	1339
DieterGraef	0:d26c1b55cfca	1340	/* The minimum value for ssthresh should be 2 MSS */
DieterGraef	0:d26c1b55cfca	1341	if (pcb->ssthresh < 2*pcb->mss) {
DieterGraef	0:d26c1b55cfca	1342	LWIP_DEBUGF(TCP_FR_DEBUG,
DieterGraef	0:d26c1b55cfca	1343	("tcp_receive: The minimum value for ssthresh %"U16_F
DieterGraef	0:d26c1b55cfca	1344	" should be min 2 mss %"U16_F"...\n",
DieterGraef	0:d26c1b55cfca	1345	pcb->ssthresh, 2*pcb->mss));
DieterGraef	0:d26c1b55cfca	1346	pcb->ssthresh = 2*pcb->mss;
DieterGraef	0:d26c1b55cfca	1347	}
DieterGraef	0:d26c1b55cfca	1348
DieterGraef	0:d26c1b55cfca	1349	pcb->cwnd = pcb->ssthresh + 3 * pcb->mss;
DieterGraef	0:d26c1b55cfca	1350	pcb->flags \|= TF_INFR;
DieterGraef	0:d26c1b55cfca	1351	}
DieterGraef	0:d26c1b55cfca	1352	}
DieterGraef	0:d26c1b55cfca	1353
DieterGraef	0:d26c1b55cfca	1354
DieterGraef	0:d26c1b55cfca	1355	/**
DieterGraef	0:d26c1b55cfca	1356	* Send keepalive packets to keep a connection active although
DieterGraef	0:d26c1b55cfca	1357	* no data is sent over it.
DieterGraef	0:d26c1b55cfca	1358	*
DieterGraef	0:d26c1b55cfca	1359	* Called by tcp_slowtmr()
DieterGraef	0:d26c1b55cfca	1360	*
DieterGraef	0:d26c1b55cfca	1361	* @param pcb the tcp_pcb for which to send a keepalive packet
DieterGraef	0:d26c1b55cfca	1362	*/
DieterGraef	0:d26c1b55cfca	1363	void
DieterGraef	0:d26c1b55cfca	1364	tcp_keepalive(struct tcp_pcb *pcb)
DieterGraef	0:d26c1b55cfca	1365	{
DieterGraef	0:d26c1b55cfca	1366	struct pbuf *p;
DieterGraef	0:d26c1b55cfca	1367	struct tcp_hdr *tcphdr;
DieterGraef	0:d26c1b55cfca	1368
DieterGraef	0:d26c1b55cfca	1369	LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: sending KEEPALIVE probe to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
DieterGraef	0:d26c1b55cfca	1370	ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip),
DieterGraef	0:d26c1b55cfca	1371	ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip)));
DieterGraef	0:d26c1b55cfca	1372
DieterGraef	0:d26c1b55cfca	1373	LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: tcp_ticks %"U32_F" pcb->tmr %"U32_F" pcb->keep_cnt_sent %"U16_F"\n",
DieterGraef	0:d26c1b55cfca	1374	tcp_ticks, pcb->tmr, pcb->keep_cnt_sent));
DieterGraef	0:d26c1b55cfca	1375
DieterGraef	0:d26c1b55cfca	1376	p = tcp_output_alloc_header(pcb, 0, 0, htonl(pcb->snd_nxt - 1));
DieterGraef	0:d26c1b55cfca	1377	if(p == NULL) {
DieterGraef	0:d26c1b55cfca	1378	LWIP_DEBUGF(TCP_DEBUG,
DieterGraef	0:d26c1b55cfca	1379	("tcp_keepalive: could not allocate memory for pbuf\n"));
DieterGraef	0:d26c1b55cfca	1380	return;
DieterGraef	0:d26c1b55cfca	1381	}
DieterGraef	0:d26c1b55cfca	1382	tcphdr = (struct tcp_hdr *)p->payload;
DieterGraef	0:d26c1b55cfca	1383
DieterGraef	0:d26c1b55cfca	1384	#if CHECKSUM_GEN_TCP
DieterGraef	0:d26c1b55cfca	1385	tcphdr->chksum = inet_chksum_pseudo(p, &pcb->local_ip, &pcb->remote_ip,
DieterGraef	0:d26c1b55cfca	1386	IP_PROTO_TCP, p->tot_len);
DieterGraef	0:d26c1b55cfca	1387	#endif
DieterGraef	0:d26c1b55cfca	1388	TCP_STATS_INC(tcp.xmit);
DieterGraef	0:d26c1b55cfca	1389
DieterGraef	0:d26c1b55cfca	1390	/* Send output to IP */
DieterGraef	0:d26c1b55cfca	1391	#if LWIP_NETIF_HWADDRHINT
DieterGraef	0:d26c1b55cfca	1392	ip_output_hinted(p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, 0, IP_PROTO_TCP,
DieterGraef	0:d26c1b55cfca	1393	&(pcb->addr_hint));
DieterGraef	0:d26c1b55cfca	1394	#else /* LWIP_NETIF_HWADDRHINT*/
DieterGraef	0:d26c1b55cfca	1395	ip_output(p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, 0, IP_PROTO_TCP);
DieterGraef	0:d26c1b55cfca	1396	#endif /* LWIP_NETIF_HWADDRHINT*/
DieterGraef	0:d26c1b55cfca	1397
DieterGraef	0:d26c1b55cfca	1398	pbuf_free(p);
DieterGraef	0:d26c1b55cfca	1399
DieterGraef	0:d26c1b55cfca	1400	LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: seqno %"U32_F" ackno %"U32_F".\n",
DieterGraef	0:d26c1b55cfca	1401	pcb->snd_nxt - 1, pcb->rcv_nxt));
DieterGraef	0:d26c1b55cfca	1402	}
DieterGraef	0:d26c1b55cfca	1403
DieterGraef	0:d26c1b55cfca	1404
DieterGraef	0:d26c1b55cfca	1405	/**
DieterGraef	0:d26c1b55cfca	1406	* Send persist timer zero-window probes to keep a connection active
DieterGraef	0:d26c1b55cfca	1407	* when a window update is lost.
DieterGraef	0:d26c1b55cfca	1408	*
DieterGraef	0:d26c1b55cfca	1409	* Called by tcp_slowtmr()
DieterGraef	0:d26c1b55cfca	1410	*
DieterGraef	0:d26c1b55cfca	1411	* @param pcb the tcp_pcb for which to send a zero-window probe packet
DieterGraef	0:d26c1b55cfca	1412	*/
DieterGraef	0:d26c1b55cfca	1413	void
DieterGraef	0:d26c1b55cfca	1414	tcp_zero_window_probe(struct tcp_pcb *pcb)
DieterGraef	0:d26c1b55cfca	1415	{
DieterGraef	0:d26c1b55cfca	1416	struct pbuf *p;
DieterGraef	0:d26c1b55cfca	1417	struct tcp_hdr *tcphdr;
DieterGraef	0:d26c1b55cfca	1418	struct tcp_seg *seg;
DieterGraef	0:d26c1b55cfca	1419	u16_t len;
DieterGraef	0:d26c1b55cfca	1420	u8_t is_fin;
DieterGraef	0:d26c1b55cfca	1421
DieterGraef	0:d26c1b55cfca	1422	LWIP_DEBUGF(TCP_DEBUG,
DieterGraef	0:d26c1b55cfca	1423	("tcp_zero_window_probe: sending ZERO WINDOW probe to %"
DieterGraef	0:d26c1b55cfca	1424	U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
DieterGraef	0:d26c1b55cfca	1425	ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip),
DieterGraef	0:d26c1b55cfca	1426	ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip)));
DieterGraef	0:d26c1b55cfca	1427
DieterGraef	0:d26c1b55cfca	1428	LWIP_DEBUGF(TCP_DEBUG,
DieterGraef	0:d26c1b55cfca	1429	("tcp_zero_window_probe: tcp_ticks %"U32_F
DieterGraef	0:d26c1b55cfca	1430	" pcb->tmr %"U32_F" pcb->keep_cnt_sent %"U16_F"\n",
DieterGraef	0:d26c1b55cfca	1431	tcp_ticks, pcb->tmr, pcb->keep_cnt_sent));
DieterGraef	0:d26c1b55cfca	1432
DieterGraef	0:d26c1b55cfca	1433	seg = pcb->unacked;
DieterGraef	0:d26c1b55cfca	1434
DieterGraef	0:d26c1b55cfca	1435	if(seg == NULL) {
DieterGraef	0:d26c1b55cfca	1436	seg = pcb->unsent;
DieterGraef	0:d26c1b55cfca	1437	}
DieterGraef	0:d26c1b55cfca	1438	if(seg == NULL) {
DieterGraef	0:d26c1b55cfca	1439	return;
DieterGraef	0:d26c1b55cfca	1440	}
DieterGraef	0:d26c1b55cfca	1441
DieterGraef	0:d26c1b55cfca	1442	is_fin = ((TCPH_FLAGS(seg->tcphdr) & TCP_FIN) != 0) && (seg->len == 0);
DieterGraef	0:d26c1b55cfca	1443	/* we want to send one seqno: either FIN or data (no options) */
DieterGraef	0:d26c1b55cfca	1444	len = is_fin ? 0 : 1;
DieterGraef	0:d26c1b55cfca	1445
DieterGraef	0:d26c1b55cfca	1446	p = tcp_output_alloc_header(pcb, 0, len, seg->tcphdr->seqno);
DieterGraef	0:d26c1b55cfca	1447	if(p == NULL) {
DieterGraef	0:d26c1b55cfca	1448	LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: no memory for pbuf\n"));
DieterGraef	0:d26c1b55cfca	1449	return;
DieterGraef	0:d26c1b55cfca	1450	}
DieterGraef	0:d26c1b55cfca	1451	tcphdr = (struct tcp_hdr *)p->payload;
DieterGraef	0:d26c1b55cfca	1452
DieterGraef	0:d26c1b55cfca	1453	if (is_fin) {
DieterGraef	0:d26c1b55cfca	1454	/* FIN segment, no data */
DieterGraef	0:d26c1b55cfca	1455	TCPH_FLAGS_SET(tcphdr, TCP_ACK \| TCP_FIN);
DieterGraef	0:d26c1b55cfca	1456	} else {
DieterGraef	0:d26c1b55cfca	1457	/* Data segment, copy in one byte from the head of the unacked queue */
DieterGraef	0:d26c1b55cfca	1458	char d = ((char )p->payload + TCP_HLEN);
DieterGraef	0:d26c1b55cfca	1459	/* Depending on whether the segment has already been sent (unacked) or not
DieterGraef	0:d26c1b55cfca	1460	(unsent), seg->p->payload points to the IP header or TCP header.
DieterGraef	0:d26c1b55cfca	1461	Ensure we copy the first TCP data byte: */
DieterGraef	0:d26c1b55cfca	1462	pbuf_copy_partial(seg->p, d, 1, seg->p->tot_len - seg->len);
DieterGraef	0:d26c1b55cfca	1463	}
DieterGraef	0:d26c1b55cfca	1464
DieterGraef	0:d26c1b55cfca	1465	#if CHECKSUM_GEN_TCP
DieterGraef	0:d26c1b55cfca	1466	tcphdr->chksum = inet_chksum_pseudo(p, &pcb->local_ip, &pcb->remote_ip,
DieterGraef	0:d26c1b55cfca	1467	IP_PROTO_TCP, p->tot_len);
DieterGraef	0:d26c1b55cfca	1468	#endif
DieterGraef	0:d26c1b55cfca	1469	TCP_STATS_INC(tcp.xmit);
DieterGraef	0:d26c1b55cfca	1470
DieterGraef	0:d26c1b55cfca	1471	/* Send output to IP */
DieterGraef	0:d26c1b55cfca	1472	#if LWIP_NETIF_HWADDRHINT
DieterGraef	0:d26c1b55cfca	1473	ip_output_hinted(p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, 0, IP_PROTO_TCP,
DieterGraef	0:d26c1b55cfca	1474	&(pcb->addr_hint));
DieterGraef	0:d26c1b55cfca	1475	#else /* LWIP_NETIF_HWADDRHINT*/
DieterGraef	0:d26c1b55cfca	1476	ip_output(p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, 0, IP_PROTO_TCP);
DieterGraef	0:d26c1b55cfca	1477	#endif /* LWIP_NETIF_HWADDRHINT*/
DieterGraef	0:d26c1b55cfca	1478
DieterGraef	0:d26c1b55cfca	1479	pbuf_free(p);
DieterGraef	0:d26c1b55cfca	1480
DieterGraef	0:d26c1b55cfca	1481	LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: seqno %"U32_F
DieterGraef	0:d26c1b55cfca	1482	" ackno %"U32_F".\n",
DieterGraef	0:d26c1b55cfca	1483	pcb->snd_nxt - 1, pcb->rcv_nxt));
DieterGraef	0:d26c1b55cfca	1484	}
DieterGraef	0:d26c1b55cfca	1485	#endif /* LWIP_TCP */

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Type:	Library
Created:	06 Oct 2016
Imports:	4
Forks:	0
Commits:	3
Dependents:	1
Dependencies:	1
Followers:	1

lwip/core/tcp_out.c@2:e0a4035b5cd1, 2016-10-06 (annotated)

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