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@@ -1,1504 +1,1543 @@
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-/**
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- * @file
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- * Transmission Control Protocol, outgoing traffic
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- *
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- * The output functions of TCP.
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- *
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- */
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-
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-/*
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- * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
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- * All rights reserved.
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- *
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- * Redistribution and use in source and binary forms, with or without modification,
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- * are permitted provided that the following conditions are met:
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- *
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- * 1. Redistributions of source code must retain the above copyright notice,
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- * this list of conditions and the following disclaimer.
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- * 2. Redistributions in binary form must reproduce the above copyright notice,
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- * this list of conditions and the following disclaimer in the documentation
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- * and/or other materials provided with the distribution.
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- * 3. The name of the author may not be used to endorse or promote products
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- * derived from this software without specific prior written permission.
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- *
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- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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- * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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- * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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- * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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- * OF SUCH DAMAGE.
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- *
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- * This file is part of the lwIP TCP/IP stack.
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- *
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- * Author: Adam Dunkels <adam@sics.se>
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- *
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- */
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-
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-#include "lwip/opt.h"
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-
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-#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
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-
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-#include "lwip/tcp_impl.h"
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-#include "lwip/def.h"
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-#include "lwip/mem.h"
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-#include "lwip/memp.h"
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-#include "lwip/ip_addr.h"
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-#include "lwip/netif.h"
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-#include "lwip/inet_chksum.h"
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-#include "lwip/stats.h"
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-#include "lwip/snmp.h"
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-#include "lwip/ip6.h"
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-#include "lwip/ip6_addr.h"
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-#include "lwip/inet_chksum.h"
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-#if LWIP_TCP_TIMESTAMPS
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-#include "lwip/sys.h"
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-#endif
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-
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-#include <string.h>
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-
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-/* Define some copy-macros for checksum-on-copy so that the code looks
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- nicer by preventing too many ifdef's. */
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-#if TCP_CHECKSUM_ON_COPY
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-#define TCP_DATA_COPY(dst, src, len, seg) do { \
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- tcp_seg_add_chksum(LWIP_CHKSUM_COPY(dst, src, len), \
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- len, &seg->chksum, &seg->chksum_swapped); \
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- seg->flags |= TF_SEG_DATA_CHECKSUMMED; } while(0)
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-#define TCP_DATA_COPY2(dst, src, len, chksum, chksum_swapped) \
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- tcp_seg_add_chksum(LWIP_CHKSUM_COPY(dst, src, len), len, chksum, chksum_swapped);
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-#else /* TCP_CHECKSUM_ON_COPY*/
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-#define TCP_DATA_COPY(dst, src, len, seg) MEMCPY(dst, src, len)
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-#define TCP_DATA_COPY2(dst, src, len, chksum, chksum_swapped) MEMCPY(dst, src, len)
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-#endif /* TCP_CHECKSUM_ON_COPY*/
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-
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-/** Define this to 1 for an extra check that the output checksum is valid
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- * (usefule when the checksum is generated by the application, not the stack) */
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-#ifndef TCP_CHECKSUM_ON_COPY_SANITY_CHECK
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-#define TCP_CHECKSUM_ON_COPY_SANITY_CHECK 0
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-#endif
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-
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-/* Forward declarations.*/
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-static void tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb);
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-
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-/** Allocate a pbuf and create a tcphdr at p->payload, used for output
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- * functions other than the default tcp_output -> tcp_output_segment
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- * (e.g. tcp_send_empty_ack, etc.)
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- *
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- * @param pcb tcp pcb for which to send a packet (used to initialize tcp_hdr)
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- * @param optlen length of header-options
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- * @param datalen length of tcp data to reserve in pbuf
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- * @param seqno_be seqno in network byte order (big-endian)
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- * @return pbuf with p->payload being the tcp_hdr
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- */
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-static struct pbuf *
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-tcp_output_alloc_header(struct tcp_pcb *pcb, u16_t optlen, u16_t datalen,
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- u32_t seqno_be /* already in network byte order */)
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-{
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- struct tcp_hdr *tcphdr;
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- struct pbuf *p = pbuf_alloc(PBUF_IP, TCP_HLEN + optlen + datalen, PBUF_RAM);
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- if (p != NULL) {
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- LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr",
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- (p->len >= TCP_HLEN + optlen));
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- tcphdr = (struct tcp_hdr *)p->payload;
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- tcphdr->src = htons(pcb->local_port);
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- tcphdr->dest = htons(pcb->remote_port);
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- tcphdr->seqno = seqno_be;
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- tcphdr->ackno = htonl(pcb->rcv_nxt);
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- TCPH_HDRLEN_FLAGS_SET(tcphdr, (5 + optlen / 4), TCP_ACK);
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- tcphdr->wnd = htons(pcb->rcv_ann_wnd);
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- tcphdr->chksum = 0;
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- tcphdr->urgp = 0;
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-
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- /* If we're sending a packet, update the announced right window edge */
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- pcb->rcv_ann_right_edge = pcb->rcv_nxt + pcb->rcv_ann_wnd;
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- }
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- return p;
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-}
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-
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-/**
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- * Called by tcp_close() to send a segment including FIN flag but not data.
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- *
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- * @param pcb the tcp_pcb over which to send a segment
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- * @return ERR_OK if sent, another err_t otherwise
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- */
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-err_t
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-tcp_send_fin(struct tcp_pcb *pcb)
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-{
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- /* first, try to add the fin to the last unsent segment */
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- if (pcb->unsent != NULL) {
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- struct tcp_seg *last_unsent;
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- for (last_unsent = pcb->unsent; last_unsent->next != NULL;
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- last_unsent = last_unsent->next);
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-
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- if ((TCPH_FLAGS(last_unsent->tcphdr) & (TCP_SYN | TCP_FIN | TCP_RST)) == 0) {
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- /* no SYN/FIN/RST flag in the header, we can add the FIN flag */
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- TCPH_SET_FLAG(last_unsent->tcphdr, TCP_FIN);
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- pcb->flags |= TF_FIN;
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- return ERR_OK;
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- }
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- }
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- /* no data, no length, flags, copy=1, no optdata */
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- return tcp_enqueue_flags(pcb, TCP_FIN);
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-}
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-
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-/**
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- * Create a TCP segment with prefilled header.
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- *
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- * Called by tcp_write and tcp_enqueue_flags.
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- *
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- * @param pcb Protocol control block for the TCP connection.
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- * @param p pbuf that is used to hold the TCP header.
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- * @param flags TCP flags for header.
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- * @param seqno TCP sequence number of this packet
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- * @param optflags options to include in TCP header
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- * @return a new tcp_seg pointing to p, or NULL.
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- * The TCP header is filled in except ackno and wnd.
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- * p is freed on failure.
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- */
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-static struct tcp_seg *
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-tcp_create_segment(struct tcp_pcb *pcb, struct pbuf *p, u8_t flags, u32_t seqno, u8_t optflags)
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-{
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- struct tcp_seg *seg;
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- u8_t optlen = LWIP_TCP_OPT_LENGTH(optflags);
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-
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- if ((seg = (struct tcp_seg *)memp_malloc(MEMP_TCP_SEG)) == NULL) {
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- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_create_segment: no memory.\n"));
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- pbuf_free(p);
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- return NULL;
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- }
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- seg->flags = optflags;
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- seg->next = NULL;
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- seg->p = p;
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- seg->len = p->tot_len - optlen;
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-#if TCP_OVERSIZE_DBGCHECK
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- seg->oversize_left = 0;
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-#endif /* TCP_OVERSIZE_DBGCHECK */
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-#if TCP_CHECKSUM_ON_COPY
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- seg->chksum = 0;
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- seg->chksum_swapped = 0;
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- /* check optflags */
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- LWIP_ASSERT("invalid optflags passed: TF_SEG_DATA_CHECKSUMMED",
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- (optflags & TF_SEG_DATA_CHECKSUMMED) == 0);
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-#endif /* TCP_CHECKSUM_ON_COPY */
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-
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- /* build TCP header */
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- if (pbuf_header(p, TCP_HLEN)) {
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- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_create_segment: no room for TCP header in pbuf.\n"));
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- TCP_STATS_INC(tcp.err);
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- tcp_seg_free(seg);
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- return NULL;
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- }
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- seg->tcphdr = (struct tcp_hdr *)seg->p->payload;
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- seg->tcphdr->src = htons(pcb->local_port);
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- seg->tcphdr->dest = htons(pcb->remote_port);
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- seg->tcphdr->seqno = htonl(seqno);
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- /* ackno is set in tcp_output */
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- TCPH_HDRLEN_FLAGS_SET(seg->tcphdr, (5 + optlen / 4), flags);
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- /* wnd and chksum are set in tcp_output */
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- seg->tcphdr->urgp = 0;
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- return seg;
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-}
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-
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-/**
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- * Allocate a PBUF_RAM pbuf, perhaps with extra space at the end.
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- *
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- * This function is like pbuf_alloc(layer, length, PBUF_RAM) except
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- * there may be extra bytes available at the end.
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- *
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- * @param layer flag to define header size.
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- * @param length size of the pbuf's payload.
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- * @param max_length maximum usable size of payload+oversize.
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- * @param oversize pointer to a u16_t that will receive the number of usable tail bytes.
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- * @param pcb The TCP connection that willo enqueue the pbuf.
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- * @param apiflags API flags given to tcp_write.
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- * @param first_seg true when this pbuf will be used in the first enqueued segment.
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- * @param
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- */
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-#if TCP_OVERSIZE
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-static struct pbuf *
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-tcp_pbuf_prealloc(pbuf_layer layer, u16_t length, u16_t max_length,
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- u16_t *oversize, struct tcp_pcb *pcb, u8_t apiflags,
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- u8_t first_seg)
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-{
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- struct pbuf *p;
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- u16_t alloc = length;
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-
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-#if LWIP_NETIF_TX_SINGLE_PBUF
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- LWIP_UNUSED_ARG(max_length);
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- LWIP_UNUSED_ARG(pcb);
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- LWIP_UNUSED_ARG(apiflags);
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- LWIP_UNUSED_ARG(first_seg);
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- /* always create MSS-sized pbufs */
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- alloc = max_length;
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-#else /* LWIP_NETIF_TX_SINGLE_PBUF */
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- if (length < max_length) {
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- /* Should we allocate an oversized pbuf, or just the minimum
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- * length required? If tcp_write is going to be called again
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- * before this segment is transmitted, we want the oversized
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- * buffer. If the segment will be transmitted immediately, we can
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- * save memory by allocating only length. We use a simple
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- * heuristic based on the following information:
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- *
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- * Did the user set TCP_WRITE_FLAG_MORE?
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- *
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- * Will the Nagle algorithm defer transmission of this segment?
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- */
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- if ((apiflags & TCP_WRITE_FLAG_MORE) ||
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- (!(pcb->flags & TF_NODELAY) &&
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- (!first_seg ||
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- pcb->unsent != NULL ||
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- pcb->unacked != NULL))) {
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- alloc = LWIP_MIN(max_length, LWIP_MEM_ALIGN_SIZE(length + TCP_OVERSIZE));
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- }
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- }
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-#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
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- p = pbuf_alloc(layer, alloc, PBUF_RAM);
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- if (p == NULL) {
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- return NULL;
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- }
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- LWIP_ASSERT("need unchained pbuf", p->next == NULL);
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- *oversize = p->len - length;
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- /* trim p->len to the currently used size */
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- p->len = p->tot_len = length;
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- return p;
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-}
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-#else /* TCP_OVERSIZE */
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-#define tcp_pbuf_prealloc(layer, length, mx, os, pcb, api, fst) pbuf_alloc((layer), (length), PBUF_RAM)
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-#endif /* TCP_OVERSIZE */
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-
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-#if TCP_CHECKSUM_ON_COPY
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-/** Add a checksum of newly added data to the segment */
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-static void
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-tcp_seg_add_chksum(u16_t chksum, u16_t len, u16_t *seg_chksum,
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- u8_t *seg_chksum_swapped)
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-{
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- u32_t helper;
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- /* add chksum to old chksum and fold to u16_t */
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- helper = chksum + *seg_chksum;
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- chksum = FOLD_U32T(helper);
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- if ((len & 1) != 0) {
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- *seg_chksum_swapped = 1 - *seg_chksum_swapped;
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- chksum = SWAP_BYTES_IN_WORD(chksum);
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- }
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- *seg_chksum = chksum;
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-}
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-#endif /* TCP_CHECKSUM_ON_COPY */
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-
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-/** Checks if tcp_write is allowed or not (checks state, snd_buf and snd_queuelen).
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- *
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- * @param pcb the tcp pcb to check for
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- * @param len length of data to send (checked agains snd_buf)
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- * @return ERR_OK if tcp_write is allowed to proceed, another err_t otherwise
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- */
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-static err_t
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-tcp_write_checks(struct tcp_pcb *pcb, u16_t len)
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-{
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- /* connection is in invalid state for data transmission? */
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- if ((pcb->state != ESTABLISHED) &&
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- (pcb->state != CLOSE_WAIT) &&
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- (pcb->state != SYN_SENT) &&
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- (pcb->state != SYN_RCVD)) {
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- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_STATE | LWIP_DBG_LEVEL_SEVERE, ("tcp_write() called in invalid state\n"));
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- return ERR_CONN;
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- } else if (len == 0) {
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- return ERR_OK;
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- }
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-
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- /* fail on too much data */
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- if (len > pcb->snd_buf) {
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- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too much data (len=%"U16_F" > snd_buf=%"U16_F")\n",
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- len, pcb->snd_buf));
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- pcb->flags |= TF_NAGLEMEMERR;
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- return ERR_MEM;
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- }
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-
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- LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen));
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-
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- /* If total number of pbufs on the unsent/unacked queues exceeds the
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- * configured maximum, return an error */
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- /* check for configured max queuelen and possible overflow */
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- if ((pcb->snd_queuelen >= TCP_SND_QUEUELEN) || (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
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- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too long queue %"U16_F" (max %"U16_F")\n",
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- pcb->snd_queuelen, TCP_SND_QUEUELEN));
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- TCP_STATS_INC(tcp.memerr);
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- pcb->flags |= TF_NAGLEMEMERR;
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- return ERR_MEM;
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- }
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- if (pcb->snd_queuelen != 0) {
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- LWIP_ASSERT("tcp_write: pbufs on queue => at least one queue non-empty",
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- pcb->unacked != NULL || pcb->unsent != NULL);
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- } else {
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- LWIP_ASSERT("tcp_write: no pbufs on queue => both queues empty",
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- pcb->unacked == NULL && pcb->unsent == NULL);
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- }
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- return ERR_OK;
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-}
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-
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-/**
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- * Write data for sending (but does not send it immediately).
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- *
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- * It waits in the expectation of more data being sent soon (as
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- * it can send them more efficiently by combining them together).
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- * To prompt the system to send data now, call tcp_output() after
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- * calling tcp_write().
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- *
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- * @param pcb Protocol control block for the TCP connection to enqueue data for.
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- * @param arg Pointer to the data to be enqueued for sending.
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- * @param len Data length in bytes
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|
|
- * @param apiflags combination of following flags :
|
|
|
- * - TCP_WRITE_FLAG_COPY (0x01) data will be copied into memory belonging to the stack
|
|
|
- * - TCP_WRITE_FLAG_MORE (0x02) for TCP connection, PSH flag will be set on last segment sent,
|
|
|
- * @return ERR_OK if enqueued, another err_t on error
|
|
|
- */
|
|
|
-err_t
|
|
|
-tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
|
|
|
-{
|
|
|
- struct pbuf *concat_p = NULL;
|
|
|
- struct tcp_seg *last_unsent = NULL, *seg = NULL, *prev_seg = NULL, *queue = NULL;
|
|
|
- u16_t pos = 0; /* position in 'arg' data */
|
|
|
- u16_t queuelen;
|
|
|
- u8_t optlen = 0;
|
|
|
- u8_t optflags = 0;
|
|
|
-#if TCP_OVERSIZE
|
|
|
- u16_t oversize = 0;
|
|
|
- u16_t oversize_used = 0;
|
|
|
-#endif /* TCP_OVERSIZE */
|
|
|
-#if TCP_CHECKSUM_ON_COPY
|
|
|
- u16_t concat_chksum = 0;
|
|
|
- u8_t concat_chksum_swapped = 0;
|
|
|
- u16_t concat_chksummed = 0;
|
|
|
-#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
- err_t err;
|
|
|
- /* don't allocate segments bigger than half the maximum window we ever received */
|
|
|
- u16_t mss_local = LWIP_MIN(pcb->mss, pcb->snd_wnd_max/2);
|
|
|
-
|
|
|
-#if LWIP_NETIF_TX_SINGLE_PBUF
|
|
|
- /* Always copy to try to create single pbufs for TX */
|
|
|
- apiflags |= TCP_WRITE_FLAG_COPY;
|
|
|
-#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
|
|
|
-
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_write(pcb=%p, data=%p, len=%"U16_F", apiflags=%"U16_F")\n",
|
|
|
- (void *)pcb, arg, len, (u16_t)apiflags));
|
|
|
- LWIP_ERROR("tcp_write: arg == NULL (programmer violates API)",
|
|
|
- arg != NULL, return ERR_ARG;);
|
|
|
-
|
|
|
- err = tcp_write_checks(pcb, len);
|
|
|
- if (err != ERR_OK) {
|
|
|
- return err;
|
|
|
- }
|
|
|
- queuelen = pcb->snd_queuelen;
|
|
|
-
|
|
|
-#if LWIP_TCP_TIMESTAMPS
|
|
|
- if ((pcb->flags & TF_TIMESTAMP)) {
|
|
|
- optflags = TF_SEG_OPTS_TS;
|
|
|
- optlen = LWIP_TCP_OPT_LENGTH(TF_SEG_OPTS_TS);
|
|
|
- }
|
|
|
-#endif /* LWIP_TCP_TIMESTAMPS */
|
|
|
-
|
|
|
-
|
|
|
- /*
|
|
|
- * TCP segmentation is done in three phases with increasing complexity:
|
|
|
- *
|
|
|
- * 1. Copy data directly into an oversized pbuf.
|
|
|
- * 2. Chain a new pbuf to the end of pcb->unsent.
|
|
|
- * 3. Create new segments.
|
|
|
- *
|
|
|
- * We may run out of memory at any point. In that case we must
|
|
|
- * return ERR_MEM and not change anything in pcb. Therefore, all
|
|
|
- * changes are recorded in local variables and committed at the end
|
|
|
- * of the function. Some pcb fields are maintained in local copies:
|
|
|
- *
|
|
|
- * queuelen = pcb->snd_queuelen
|
|
|
- * oversize = pcb->unsent_oversize
|
|
|
- *
|
|
|
- * These variables are set consistently by the phases:
|
|
|
- *
|
|
|
- * seg points to the last segment tampered with.
|
|
|
- *
|
|
|
- * pos records progress as data is segmented.
|
|
|
- */
|
|
|
-
|
|
|
- /* Find the tail of the unsent queue. */
|
|
|
- if (pcb->unsent != NULL) {
|
|
|
- u16_t space;
|
|
|
- u16_t unsent_optlen;
|
|
|
-
|
|
|
- /* @todo: this could be sped up by keeping last_unsent in the pcb */
|
|
|
- for (last_unsent = pcb->unsent; last_unsent->next != NULL;
|
|
|
- last_unsent = last_unsent->next);
|
|
|
-
|
|
|
- /* Usable space at the end of the last unsent segment */
|
|
|
- unsent_optlen = LWIP_TCP_OPT_LENGTH(last_unsent->flags);
|
|
|
- space = mss_local - (last_unsent->len + unsent_optlen);
|
|
|
-
|
|
|
- /*
|
|
|
- * Phase 1: Copy data directly into an oversized pbuf.
|
|
|
- *
|
|
|
- * The number of bytes copied is recorded in the oversize_used
|
|
|
- * variable. The actual copying is done at the bottom of the
|
|
|
- * function.
|
|
|
- */
|
|
|
-#if TCP_OVERSIZE
|
|
|
-#if TCP_OVERSIZE_DBGCHECK
|
|
|
- /* check that pcb->unsent_oversize matches last_unsent->unsent_oversize */
|
|
|
- LWIP_ASSERT("unsent_oversize mismatch (pcb vs. last_unsent)",
|
|
|
- pcb->unsent_oversize == last_unsent->oversize_left);
|
|
|
-#endif /* TCP_OVERSIZE_DBGCHECK */
|
|
|
- oversize = pcb->unsent_oversize;
|
|
|
- if (oversize > 0) {
|
|
|
- LWIP_ASSERT("inconsistent oversize vs. space", oversize_used <= space);
|
|
|
- seg = last_unsent;
|
|
|
- oversize_used = oversize < len ? oversize : len;
|
|
|
- pos += oversize_used;
|
|
|
- oversize -= oversize_used;
|
|
|
- space -= oversize_used;
|
|
|
- }
|
|
|
- /* now we are either finished or oversize is zero */
|
|
|
- LWIP_ASSERT("inconsistend oversize vs. len", (oversize == 0) || (pos == len));
|
|
|
-#endif /* TCP_OVERSIZE */
|
|
|
-
|
|
|
- /*
|
|
|
- * Phase 2: Chain a new pbuf to the end of pcb->unsent.
|
|
|
- *
|
|
|
- * We don't extend segments containing SYN/FIN flags or options
|
|
|
- * (len==0). The new pbuf is kept in concat_p and pbuf_cat'ed at
|
|
|
- * the end.
|
|
|
- */
|
|
|
- if ((pos < len) && (space > 0) && (last_unsent->len > 0)) {
|
|
|
- u16_t seglen = space < len - pos ? space : len - pos;
|
|
|
- seg = last_unsent;
|
|
|
-
|
|
|
- /* Create a pbuf with a copy or reference to seglen bytes. We
|
|
|
- * can use PBUF_RAW here since the data appears in the middle of
|
|
|
- * a segment. A header will never be prepended. */
|
|
|
- if (apiflags & TCP_WRITE_FLAG_COPY) {
|
|
|
- /* Data is copied */
|
|
|
- if ((concat_p = tcp_pbuf_prealloc(PBUF_RAW, seglen, space, &oversize, pcb, apiflags, 1)) == NULL) {
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2,
|
|
|
- ("tcp_write : could not allocate memory for pbuf copy size %"U16_F"\n",
|
|
|
- seglen));
|
|
|
- goto memerr;
|
|
|
- }
|
|
|
-#if TCP_OVERSIZE_DBGCHECK
|
|
|
- last_unsent->oversize_left += oversize;
|
|
|
-#endif /* TCP_OVERSIZE_DBGCHECK */
|
|
|
- TCP_DATA_COPY2(concat_p->payload, (u8_t*)arg + pos, seglen, &concat_chksum, &concat_chksum_swapped);
|
|
|
-#if TCP_CHECKSUM_ON_COPY
|
|
|
- concat_chksummed += seglen;
|
|
|
-#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
- } else {
|
|
|
- /* Data is not copied */
|
|
|
- if ((concat_p = pbuf_alloc(PBUF_RAW, seglen, PBUF_ROM)) == NULL) {
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2,
|
|
|
- ("tcp_write: could not allocate memory for zero-copy pbuf\n"));
|
|
|
- goto memerr;
|
|
|
- }
|
|
|
-#if TCP_CHECKSUM_ON_COPY
|
|
|
- /* calculate the checksum of nocopy-data */
|
|
|
- tcp_seg_add_chksum(~inet_chksum((u8_t*)arg + pos, seglen), seglen,
|
|
|
- &concat_chksum, &concat_chksum_swapped);
|
|
|
- concat_chksummed += seglen;
|
|
|
-#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
- /* reference the non-volatile payload data */
|
|
|
- concat_p->payload = (u8_t*)arg + pos;
|
|
|
- }
|
|
|
-
|
|
|
- pos += seglen;
|
|
|
- queuelen += pbuf_clen(concat_p);
|
|
|
- }
|
|
|
- } else {
|
|
|
-#if TCP_OVERSIZE
|
|
|
- LWIP_ASSERT("unsent_oversize mismatch (pcb->unsent is NULL)",
|
|
|
- pcb->unsent_oversize == 0);
|
|
|
-#endif /* TCP_OVERSIZE */
|
|
|
- }
|
|
|
-
|
|
|
- /*
|
|
|
- * Phase 3: Create new segments.
|
|
|
- *
|
|
|
- * The new segments are chained together in the local 'queue'
|
|
|
- * variable, ready to be appended to pcb->unsent.
|
|
|
- */
|
|
|
- while (pos < len) {
|
|
|
- struct pbuf *p;
|
|
|
- u16_t left = len - pos;
|
|
|
- u16_t max_len = mss_local - optlen;
|
|
|
- u16_t seglen = left > max_len ? max_len : left;
|
|
|
-#if TCP_CHECKSUM_ON_COPY
|
|
|
- u16_t chksum = 0;
|
|
|
- u8_t chksum_swapped = 0;
|
|
|
-#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
-
|
|
|
- if (apiflags & TCP_WRITE_FLAG_COPY) {
|
|
|
- /* If copy is set, memory should be allocated and data copied
|
|
|
- * into pbuf */
|
|
|
- if ((p = tcp_pbuf_prealloc(PBUF_TRANSPORT, seglen + optlen, mss_local, &oversize, pcb, apiflags, queue == NULL)) == NULL) {
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write : could not allocate memory for pbuf copy size %"U16_F"\n", seglen));
|
|
|
- goto memerr;
|
|
|
- }
|
|
|
- LWIP_ASSERT("tcp_write: check that first pbuf can hold the complete seglen",
|
|
|
- (p->len >= seglen));
|
|
|
- TCP_DATA_COPY2((char *)p->payload + optlen, (u8_t*)arg + pos, seglen, &chksum, &chksum_swapped);
|
|
|
- } else {
|
|
|
- /* Copy is not set: First allocate a pbuf for holding the data.
|
|
|
- * Since the referenced data is available at least until it is
|
|
|
- * sent out on the link (as it has to be ACKed by the remote
|
|
|
- * party) we can safely use PBUF_ROM instead of PBUF_REF here.
|
|
|
- */
|
|
|
- struct pbuf *p2;
|
|
|
-#if TCP_OVERSIZE
|
|
|
- LWIP_ASSERT("oversize == 0", oversize == 0);
|
|
|
-#endif /* TCP_OVERSIZE */
|
|
|
- if ((p2 = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_ROM)) == NULL) {
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: could not allocate memory for zero-copy pbuf\n"));
|
|
|
- goto memerr;
|
|
|
- }
|
|
|
-#if TCP_CHECKSUM_ON_COPY
|
|
|
- /* calculate the checksum of nocopy-data */
|
|
|
- chksum = ~inet_chksum((u8_t*)arg + pos, seglen);
|
|
|
-#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
- /* reference the non-volatile payload data */
|
|
|
- p2->payload = (u8_t*)arg + pos;
|
|
|
-
|
|
|
- /* Second, allocate a pbuf for the headers. */
|
|
|
- if ((p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) {
|
|
|
- /* If allocation fails, we have to deallocate the data pbuf as
|
|
|
- * well. */
|
|
|
- pbuf_free(p2);
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: could not allocate memory for header pbuf\n"));
|
|
|
- goto memerr;
|
|
|
- }
|
|
|
- /* Concatenate the headers and data pbufs together. */
|
|
|
- pbuf_cat(p/*header*/, p2/*data*/);
|
|
|
- }
|
|
|
-
|
|
|
- queuelen += pbuf_clen(p);
|
|
|
-
|
|
|
- /* Now that there are more segments queued, we check again if the
|
|
|
- * length of the queue exceeds the configured maximum or
|
|
|
- * overflows. */
|
|
|
- if ((queuelen > TCP_SND_QUEUELEN) || (queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: queue too long %"U16_F" (%"U16_F")\n", queuelen, TCP_SND_QUEUELEN));
|
|
|
- pbuf_free(p);
|
|
|
- goto memerr;
|
|
|
- }
|
|
|
-
|
|
|
- if ((seg = tcp_create_segment(pcb, p, 0, pcb->snd_lbb + pos, optflags)) == NULL) {
|
|
|
- goto memerr;
|
|
|
- }
|
|
|
-#if TCP_OVERSIZE_DBGCHECK
|
|
|
- seg->oversize_left = oversize;
|
|
|
-#endif /* TCP_OVERSIZE_DBGCHECK */
|
|
|
-#if TCP_CHECKSUM_ON_COPY
|
|
|
- seg->chksum = chksum;
|
|
|
- seg->chksum_swapped = chksum_swapped;
|
|
|
- seg->flags |= TF_SEG_DATA_CHECKSUMMED;
|
|
|
-#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
-
|
|
|
- /* first segment of to-be-queued data? */
|
|
|
- if (queue == NULL) {
|
|
|
- queue = seg;
|
|
|
- } else {
|
|
|
- /* Attach the segment to the end of the queued segments */
|
|
|
- LWIP_ASSERT("prev_seg != NULL", prev_seg != NULL);
|
|
|
- prev_seg->next = seg;
|
|
|
- }
|
|
|
- /* remember last segment of to-be-queued data for next iteration */
|
|
|
- prev_seg = seg;
|
|
|
-
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_TRACE, ("tcp_write: queueing %"U32_F":%"U32_F"\n",
|
|
|
- ntohl(seg->tcphdr->seqno),
|
|
|
- ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg)));
|
|
|
-
|
|
|
- pos += seglen;
|
|
|
- }
|
|
|
-
|
|
|
- /*
|
|
|
- * All three segmentation phases were successful. We can commit the
|
|
|
- * transaction.
|
|
|
- */
|
|
|
-
|
|
|
- /*
|
|
|
- * Phase 1: If data has been added to the preallocated tail of
|
|
|
- * last_unsent, we update the length fields of the pbuf chain.
|
|
|
- */
|
|
|
-#if TCP_OVERSIZE
|
|
|
- if (oversize_used > 0) {
|
|
|
- struct pbuf *p;
|
|
|
- /* Bump tot_len of whole chain, len of tail */
|
|
|
- for (p = last_unsent->p; p; p = p->next) {
|
|
|
- p->tot_len += oversize_used;
|
|
|
- if (p->next == NULL) {
|
|
|
- TCP_DATA_COPY((char *)p->payload + p->len, arg, oversize_used, last_unsent);
|
|
|
- p->len += oversize_used;
|
|
|
- }
|
|
|
- }
|
|
|
- last_unsent->len += oversize_used;
|
|
|
-#if TCP_OVERSIZE_DBGCHECK
|
|
|
- LWIP_ASSERT("last_unsent->oversize_left >= oversize_used",
|
|
|
- last_unsent->oversize_left >= oversize_used);
|
|
|
- last_unsent->oversize_left -= oversize_used;
|
|
|
-#endif /* TCP_OVERSIZE_DBGCHECK */
|
|
|
- }
|
|
|
- pcb->unsent_oversize = oversize;
|
|
|
-#endif /* TCP_OVERSIZE */
|
|
|
-
|
|
|
- /*
|
|
|
- * Phase 2: concat_p can be concatenated onto last_unsent->p
|
|
|
- */
|
|
|
- if (concat_p != NULL) {
|
|
|
- LWIP_ASSERT("tcp_write: cannot concatenate when pcb->unsent is empty",
|
|
|
- (last_unsent != NULL));
|
|
|
- pbuf_cat(last_unsent->p, concat_p);
|
|
|
- last_unsent->len += concat_p->tot_len;
|
|
|
-#if TCP_CHECKSUM_ON_COPY
|
|
|
- if (concat_chksummed) {
|
|
|
- tcp_seg_add_chksum(concat_chksum, concat_chksummed, &last_unsent->chksum,
|
|
|
- &last_unsent->chksum_swapped);
|
|
|
- last_unsent->flags |= TF_SEG_DATA_CHECKSUMMED;
|
|
|
- }
|
|
|
-#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
- }
|
|
|
-
|
|
|
- /*
|
|
|
- * Phase 3: Append queue to pcb->unsent. Queue may be NULL, but that
|
|
|
- * is harmless
|
|
|
- */
|
|
|
- if (last_unsent == NULL) {
|
|
|
- pcb->unsent = queue;
|
|
|
- } else {
|
|
|
- last_unsent->next = queue;
|
|
|
- }
|
|
|
-
|
|
|
- /*
|
|
|
- * Finally update the pcb state.
|
|
|
- */
|
|
|
- pcb->snd_lbb += len;
|
|
|
- pcb->snd_buf -= len;
|
|
|
- pcb->snd_queuelen = queuelen;
|
|
|
-
|
|
|
- LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: %"S16_F" (after enqueued)\n",
|
|
|
- pcb->snd_queuelen));
|
|
|
- if (pcb->snd_queuelen != 0) {
|
|
|
- LWIP_ASSERT("tcp_write: valid queue length",
|
|
|
- pcb->unacked != NULL || pcb->unsent != NULL);
|
|
|
- }
|
|
|
-
|
|
|
- /* Set the PSH flag in the last segment that we enqueued. */
|
|
|
- if (seg != NULL && seg->tcphdr != NULL && ((apiflags & TCP_WRITE_FLAG_MORE)==0)) {
|
|
|
- TCPH_SET_FLAG(seg->tcphdr, TCP_PSH);
|
|
|
- }
|
|
|
-
|
|
|
- return ERR_OK;
|
|
|
-memerr:
|
|
|
- pcb->flags |= TF_NAGLEMEMERR;
|
|
|
- TCP_STATS_INC(tcp.memerr);
|
|
|
-
|
|
|
- if (concat_p != NULL) {
|
|
|
- pbuf_free(concat_p);
|
|
|
- }
|
|
|
- if (queue != NULL) {
|
|
|
- tcp_segs_free(queue);
|
|
|
- }
|
|
|
- if (pcb->snd_queuelen != 0) {
|
|
|
- LWIP_ASSERT("tcp_write: valid queue length", pcb->unacked != NULL ||
|
|
|
- pcb->unsent != NULL);
|
|
|
- }
|
|
|
- LWIP_DEBUGF(TCP_QLEN_DEBUG | LWIP_DBG_STATE, ("tcp_write: %"S16_F" (with mem err)\n", pcb->snd_queuelen));
|
|
|
- return ERR_MEM;
|
|
|
-}
|
|
|
-
|
|
|
-/**
|
|
|
- * Enqueue TCP options for transmission.
|
|
|
- *
|
|
|
- * Called by tcp_connect(), tcp_listen_input(), and tcp_send_ctrl().
|
|
|
- *
|
|
|
- * @param pcb Protocol control block for the TCP connection.
|
|
|
- * @param flags TCP header flags to set in the outgoing segment.
|
|
|
- * @param optdata pointer to TCP options, or NULL.
|
|
|
- * @param optlen length of TCP options in bytes.
|
|
|
- */
|
|
|
-err_t
|
|
|
-tcp_enqueue_flags(struct tcp_pcb *pcb, u8_t flags)
|
|
|
-{
|
|
|
- struct pbuf *p;
|
|
|
- struct tcp_seg *seg;
|
|
|
- u8_t optflags = 0;
|
|
|
- u8_t optlen = 0;
|
|
|
-
|
|
|
- LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue_flags: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen));
|
|
|
-
|
|
|
- LWIP_ASSERT("tcp_enqueue_flags: need either TCP_SYN or TCP_FIN in flags (programmer violates API)",
|
|
|
- (flags & (TCP_SYN | TCP_FIN)) != 0);
|
|
|
-
|
|
|
- /* check for configured max queuelen and possible overflow */
|
|
|
- if ((pcb->snd_queuelen >= TCP_SND_QUEUELEN) || (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_enqueue_flags: too long queue %"U16_F" (max %"U16_F")\n",
|
|
|
- pcb->snd_queuelen, TCP_SND_QUEUELEN));
|
|
|
- TCP_STATS_INC(tcp.memerr);
|
|
|
- pcb->flags |= TF_NAGLEMEMERR;
|
|
|
- return ERR_MEM;
|
|
|
- }
|
|
|
-
|
|
|
- if (flags & TCP_SYN) {
|
|
|
- optflags = TF_SEG_OPTS_MSS;
|
|
|
- }
|
|
|
-#if LWIP_TCP_TIMESTAMPS
|
|
|
- if ((pcb->flags & TF_TIMESTAMP)) {
|
|
|
- optflags |= TF_SEG_OPTS_TS;
|
|
|
- }
|
|
|
-#endif /* LWIP_TCP_TIMESTAMPS */
|
|
|
- optlen = LWIP_TCP_OPT_LENGTH(optflags);
|
|
|
-
|
|
|
- /* tcp_enqueue_flags is always called with either SYN or FIN in flags.
|
|
|
- * We need one available snd_buf byte to do that.
|
|
|
- * This means we can't send FIN while snd_buf==0. A better fix would be to
|
|
|
- * not include SYN and FIN sequence numbers in the snd_buf count. */
|
|
|
- if (pcb->snd_buf == 0) {
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_enqueue_flags: no send buffer available\n"));
|
|
|
- TCP_STATS_INC(tcp.memerr);
|
|
|
- return ERR_MEM;
|
|
|
- }
|
|
|
-
|
|
|
- /* Allocate pbuf with room for TCP header + options */
|
|
|
- if ((p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) {
|
|
|
- pcb->flags |= TF_NAGLEMEMERR;
|
|
|
- TCP_STATS_INC(tcp.memerr);
|
|
|
- return ERR_MEM;
|
|
|
- }
|
|
|
- LWIP_ASSERT("tcp_enqueue_flags: check that first pbuf can hold optlen",
|
|
|
- (p->len >= optlen));
|
|
|
-
|
|
|
- /* Allocate memory for tcp_seg, and fill in fields. */
|
|
|
- if ((seg = tcp_create_segment(pcb, p, flags, pcb->snd_lbb, optflags)) == NULL) {
|
|
|
- pcb->flags |= TF_NAGLEMEMERR;
|
|
|
- TCP_STATS_INC(tcp.memerr);
|
|
|
- return ERR_MEM;
|
|
|
- }
|
|
|
- LWIP_ASSERT("seg->tcphdr not aligned", ((mem_ptr_t)seg->tcphdr % MEM_ALIGNMENT) == 0);
|
|
|
- LWIP_ASSERT("tcp_enqueue_flags: invalid segment length", seg->len == 0);
|
|
|
-
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_TRACE,
|
|
|
- ("tcp_enqueue_flags: queueing %"U32_F":%"U32_F" (0x%"X16_F")\n",
|
|
|
- ntohl(seg->tcphdr->seqno),
|
|
|
- ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg),
|
|
|
- (u16_t)flags));
|
|
|
-
|
|
|
- /* Now append seg to pcb->unsent queue */
|
|
|
- if (pcb->unsent == NULL) {
|
|
|
- pcb->unsent = seg;
|
|
|
- } else {
|
|
|
- struct tcp_seg *useg;
|
|
|
- for (useg = pcb->unsent; useg->next != NULL; useg = useg->next);
|
|
|
- useg->next = seg;
|
|
|
- }
|
|
|
-#if TCP_OVERSIZE
|
|
|
- /* The new unsent tail has no space */
|
|
|
- pcb->unsent_oversize = 0;
|
|
|
-#endif /* TCP_OVERSIZE */
|
|
|
-
|
|
|
- /* SYN and FIN bump the sequence number */
|
|
|
- if ((flags & TCP_SYN) || (flags & TCP_FIN)) {
|
|
|
- pcb->snd_lbb++;
|
|
|
- /* optlen does not influence snd_buf */
|
|
|
- pcb->snd_buf--;
|
|
|
- }
|
|
|
- if (flags & TCP_FIN) {
|
|
|
- pcb->flags |= TF_FIN;
|
|
|
- }
|
|
|
-
|
|
|
- /* update number of segments on the queues */
|
|
|
- pcb->snd_queuelen += pbuf_clen(seg->p);
|
|
|
- LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue_flags: %"S16_F" (after enqueued)\n", pcb->snd_queuelen));
|
|
|
- if (pcb->snd_queuelen != 0) {
|
|
|
- LWIP_ASSERT("tcp_enqueue_flags: invalid queue length",
|
|
|
- pcb->unacked != NULL || pcb->unsent != NULL);
|
|
|
- }
|
|
|
-
|
|
|
- return ERR_OK;
|
|
|
-}
|
|
|
-
|
|
|
-#if LWIP_TCP_TIMESTAMPS
|
|
|
-/* Build a timestamp option (12 bytes long) at the specified options pointer)
|
|
|
- *
|
|
|
- * @param pcb tcp_pcb
|
|
|
- * @param opts option pointer where to store the timestamp option
|
|
|
- */
|
|
|
-static void
|
|
|
-tcp_build_timestamp_option(struct tcp_pcb *pcb, u32_t *opts)
|
|
|
-{
|
|
|
- /* Pad with two NOP options to make everything nicely aligned */
|
|
|
- opts[0] = PP_HTONL(0x0101080A);
|
|
|
- opts[1] = htonl(sys_now());
|
|
|
- opts[2] = htonl(pcb->ts_recent);
|
|
|
-}
|
|
|
-#endif
|
|
|
-
|
|
|
-/** Send an ACK without data.
|
|
|
- *
|
|
|
- * @param pcb Protocol control block for the TCP connection to send the ACK
|
|
|
- */
|
|
|
-err_t
|
|
|
-tcp_send_empty_ack(struct tcp_pcb *pcb)
|
|
|
-{
|
|
|
- struct pbuf *p;
|
|
|
- u8_t optlen = 0;
|
|
|
-#if LWIP_TCP_TIMESTAMPS || CHECKSUM_GEN_TCP
|
|
|
- struct tcp_hdr *tcphdr;
|
|
|
-#endif /* LWIP_TCP_TIMESTAMPS || CHECKSUM_GEN_TCP */
|
|
|
-
|
|
|
-#if LWIP_TCP_TIMESTAMPS
|
|
|
- if (pcb->flags & TF_TIMESTAMP) {
|
|
|
- optlen = LWIP_TCP_OPT_LENGTH(TF_SEG_OPTS_TS);
|
|
|
- }
|
|
|
-#endif
|
|
|
-
|
|
|
- p = tcp_output_alloc_header(pcb, optlen, 0, htonl(pcb->snd_nxt));
|
|
|
- if (p == NULL) {
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: (ACK) could not allocate pbuf\n"));
|
|
|
- return ERR_BUF;
|
|
|
- }
|
|
|
-#if LWIP_TCP_TIMESTAMPS || CHECKSUM_GEN_TCP
|
|
|
- tcphdr = (struct tcp_hdr *)p->payload;
|
|
|
-#endif /* LWIP_TCP_TIMESTAMPS || CHECKSUM_GEN_TCP */
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG,
|
|
|
- ("tcp_output: sending ACK for %"U32_F"\n", pcb->rcv_nxt));
|
|
|
- /* remove ACK flags from the PCB, as we send an empty ACK now */
|
|
|
- pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
|
|
|
-
|
|
|
- /* NB. MSS option is only sent on SYNs, so ignore it here */
|
|
|
-#if LWIP_TCP_TIMESTAMPS
|
|
|
- pcb->ts_lastacksent = pcb->rcv_nxt;
|
|
|
-
|
|
|
- if (pcb->flags & TF_TIMESTAMP) {
|
|
|
- tcp_build_timestamp_option(pcb, (u32_t *)(tcphdr + 1));
|
|
|
- }
|
|
|
-#endif
|
|
|
-
|
|
|
-#if CHECKSUM_GEN_TCP
|
|
|
- tcphdr->chksum = ipX_chksum_pseudo(PCB_ISIPV6(pcb), p, IP_PROTO_TCP, p->tot_len,
|
|
|
- &pcb->local_ip, &pcb->remote_ip);
|
|
|
-#endif
|
|
|
-#if LWIP_NETIF_HWADDRHINT
|
|
|
- ipX_output_hinted(PCB_ISIPV6(pcb), p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, pcb->tos,
|
|
|
- IP_PROTO_TCP, &pcb->addr_hint);
|
|
|
-#else /* LWIP_NETIF_HWADDRHINT*/
|
|
|
- ipX_output(PCB_ISIPV6(pcb), p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, pcb->tos,
|
|
|
- IP_PROTO_TCP);
|
|
|
-#endif /* LWIP_NETIF_HWADDRHINT*/
|
|
|
- pbuf_free(p);
|
|
|
-
|
|
|
- return ERR_OK;
|
|
|
-}
|
|
|
-
|
|
|
-/**
|
|
|
- * Find out what we can send and send it
|
|
|
- *
|
|
|
- * @param pcb Protocol control block for the TCP connection to send data
|
|
|
- * @return ERR_OK if data has been sent or nothing to send
|
|
|
- * another err_t on error
|
|
|
- */
|
|
|
-err_t
|
|
|
-tcp_output(struct tcp_pcb *pcb)
|
|
|
-{
|
|
|
- struct tcp_seg *seg, *useg;
|
|
|
- u32_t wnd, snd_nxt;
|
|
|
-#if TCP_CWND_DEBUG
|
|
|
- s16_t i = 0;
|
|
|
-#endif /* TCP_CWND_DEBUG */
|
|
|
-
|
|
|
- /* pcb->state LISTEN not allowed here */
|
|
|
- LWIP_ASSERT("don't call tcp_output for listen-pcbs",
|
|
|
- pcb->state != LISTEN);
|
|
|
-
|
|
|
- /* First, check if we are invoked by the TCP input processing
|
|
|
- code. If so, we do not output anything. Instead, we rely on the
|
|
|
- input processing code to call us when input processing is done
|
|
|
- with. */
|
|
|
- if (tcp_input_pcb == pcb) {
|
|
|
- return ERR_OK;
|
|
|
- }
|
|
|
-
|
|
|
- wnd = LWIP_MIN(pcb->snd_wnd, pcb->cwnd);
|
|
|
-
|
|
|
- seg = pcb->unsent;
|
|
|
-
|
|
|
- /* If the TF_ACK_NOW flag is set and no data will be sent (either
|
|
|
- * because the ->unsent queue is empty or because the window does
|
|
|
- * not allow it), construct an empty ACK segment and send it.
|
|
|
- *
|
|
|
- * If data is to be sent, we will just piggyback the ACK (see below).
|
|
|
- */
|
|
|
- if (pcb->flags & TF_ACK_NOW &&
|
|
|
- (seg == NULL ||
|
|
|
- ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len > wnd)) {
|
|
|
- return tcp_send_empty_ack(pcb);
|
|
|
- }
|
|
|
-
|
|
|
- /* useg should point to last segment on unacked queue */
|
|
|
- useg = pcb->unacked;
|
|
|
- if (useg != NULL) {
|
|
|
- for (; useg->next != NULL; useg = useg->next);
|
|
|
- }
|
|
|
-
|
|
|
-#if TCP_OUTPUT_DEBUG
|
|
|
- if (seg == NULL) {
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: nothing to send (%p)\n",
|
|
|
- (void*)pcb->unsent));
|
|
|
- }
|
|
|
-#endif /* TCP_OUTPUT_DEBUG */
|
|
|
-#if TCP_CWND_DEBUG
|
|
|
- if (seg == NULL) {
|
|
|
- LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_output: snd_wnd %"U16_F
|
|
|
- ", cwnd %"U16_F", wnd %"U32_F
|
|
|
- ", seg == NULL, ack %"U32_F"\n",
|
|
|
- pcb->snd_wnd, pcb->cwnd, wnd, pcb->lastack));
|
|
|
- } else {
|
|
|
- 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"\n",
|
|
|
- pcb->snd_wnd, pcb->cwnd, wnd,
|
|
|
- ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len,
|
|
|
- ntohl(seg->tcphdr->seqno), pcb->lastack));
|
|
|
- }
|
|
|
-#endif /* TCP_CWND_DEBUG */
|
|
|
- /* data available and window allows it to be sent? */
|
|
|
- while (seg != NULL &&
|
|
|
- ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len <= wnd) {
|
|
|
- LWIP_ASSERT("RST not expected here!",
|
|
|
- (TCPH_FLAGS(seg->tcphdr) & TCP_RST) == 0);
|
|
|
- /* Stop sending if the nagle algorithm would prevent it
|
|
|
- * Don't stop:
|
|
|
- * - if tcp_write had a memory error before (prevent delayed ACK timeout) or
|
|
|
- * - if FIN was already enqueued for this PCB (SYN is always alone in a segment -
|
|
|
- * either seg->next != NULL or pcb->unacked == NULL;
|
|
|
- * RST is no sent using tcp_write/tcp_output.
|
|
|
- */
|
|
|
- if((tcp_do_output_nagle(pcb) == 0) &&
|
|
|
- ((pcb->flags & (TF_NAGLEMEMERR | TF_FIN)) == 0)){
|
|
|
- break;
|
|
|
- }
|
|
|
-#if TCP_CWND_DEBUG
|
|
|
- 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",
|
|
|
- pcb->snd_wnd, pcb->cwnd, wnd,
|
|
|
- ntohl(seg->tcphdr->seqno) + seg->len -
|
|
|
- pcb->lastack,
|
|
|
- ntohl(seg->tcphdr->seqno), pcb->lastack, i));
|
|
|
- ++i;
|
|
|
-#endif /* TCP_CWND_DEBUG */
|
|
|
-
|
|
|
- pcb->unsent = seg->next;
|
|
|
-
|
|
|
- if (pcb->state != SYN_SENT) {
|
|
|
- TCPH_SET_FLAG(seg->tcphdr, TCP_ACK);
|
|
|
- pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
|
|
|
- }
|
|
|
-
|
|
|
-#if TCP_OVERSIZE_DBGCHECK
|
|
|
- seg->oversize_left = 0;
|
|
|
-#endif /* TCP_OVERSIZE_DBGCHECK */
|
|
|
- tcp_output_segment(seg, pcb);
|
|
|
- snd_nxt = ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg);
|
|
|
- if (TCP_SEQ_LT(pcb->snd_nxt, snd_nxt)) {
|
|
|
- pcb->snd_nxt = snd_nxt;
|
|
|
- }
|
|
|
- /* put segment on unacknowledged list if length > 0 */
|
|
|
- if (TCP_TCPLEN(seg) > 0) {
|
|
|
- seg->next = NULL;
|
|
|
- /* unacked list is empty? */
|
|
|
- if (pcb->unacked == NULL) {
|
|
|
- pcb->unacked = seg;
|
|
|
- useg = seg;
|
|
|
- /* unacked list is not empty? */
|
|
|
- } else {
|
|
|
- /* In the case of fast retransmit, the packet should not go to the tail
|
|
|
- * of the unacked queue, but rather somewhere before it. We need to check for
|
|
|
- * this case. -STJ Jul 27, 2004 */
|
|
|
- if (TCP_SEQ_LT(ntohl(seg->tcphdr->seqno), ntohl(useg->tcphdr->seqno))) {
|
|
|
- /* add segment to before tail of unacked list, keeping the list sorted */
|
|
|
- struct tcp_seg **cur_seg = &(pcb->unacked);
|
|
|
- while (*cur_seg &&
|
|
|
- TCP_SEQ_LT(ntohl((*cur_seg)->tcphdr->seqno), ntohl(seg->tcphdr->seqno))) {
|
|
|
- cur_seg = &((*cur_seg)->next );
|
|
|
- }
|
|
|
- seg->next = (*cur_seg);
|
|
|
- (*cur_seg) = seg;
|
|
|
- } else {
|
|
|
- /* add segment to tail of unacked list */
|
|
|
- useg->next = seg;
|
|
|
- useg = useg->next;
|
|
|
- }
|
|
|
- }
|
|
|
- /* do not queue empty segments on the unacked list */
|
|
|
- } else {
|
|
|
- tcp_seg_free(seg);
|
|
|
- }
|
|
|
- seg = pcb->unsent;
|
|
|
- }
|
|
|
-#if TCP_OVERSIZE
|
|
|
- if (pcb->unsent == NULL) {
|
|
|
- /* last unsent has been removed, reset unsent_oversize */
|
|
|
- pcb->unsent_oversize = 0;
|
|
|
- }
|
|
|
-#endif /* TCP_OVERSIZE */
|
|
|
-
|
|
|
- pcb->flags &= ~TF_NAGLEMEMERR;
|
|
|
- return ERR_OK;
|
|
|
-}
|
|
|
-
|
|
|
-/**
|
|
|
- * Called by tcp_output() to actually send a TCP segment over IP.
|
|
|
- *
|
|
|
- * @param seg the tcp_seg to send
|
|
|
- * @param pcb the tcp_pcb for the TCP connection used to send the segment
|
|
|
- */
|
|
|
-static void
|
|
|
-tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb)
|
|
|
-{
|
|
|
- u16_t len;
|
|
|
- u32_t *opts;
|
|
|
-
|
|
|
- /** @bug Exclude retransmitted segments from this count. */
|
|
|
- snmp_inc_tcpoutsegs();
|
|
|
-
|
|
|
- /* The TCP header has already been constructed, but the ackno and
|
|
|
- wnd fields remain. */
|
|
|
- seg->tcphdr->ackno = htonl(pcb->rcv_nxt);
|
|
|
-
|
|
|
- /* advertise our receive window size in this TCP segment */
|
|
|
- seg->tcphdr->wnd = htons(pcb->rcv_ann_wnd);
|
|
|
-
|
|
|
- pcb->rcv_ann_right_edge = pcb->rcv_nxt + pcb->rcv_ann_wnd;
|
|
|
-
|
|
|
- /* Add any requested options. NB MSS option is only set on SYN
|
|
|
- packets, so ignore it here */
|
|
|
- opts = (u32_t *)(void *)(seg->tcphdr + 1);
|
|
|
- if (seg->flags & TF_SEG_OPTS_MSS) {
|
|
|
- u16_t mss;
|
|
|
-#if TCP_CALCULATE_EFF_SEND_MSS
|
|
|
- mss = tcp_eff_send_mss(TCP_MSS, &pcb->local_ip, &pcb->remote_ip, PCB_ISIPV6(pcb));
|
|
|
-#else /* TCP_CALCULATE_EFF_SEND_MSS */
|
|
|
- mss = TCP_MSS;
|
|
|
-#endif /* TCP_CALCULATE_EFF_SEND_MSS */
|
|
|
- *opts = TCP_BUILD_MSS_OPTION(mss);
|
|
|
- opts += 1;
|
|
|
- }
|
|
|
-#if LWIP_TCP_TIMESTAMPS
|
|
|
- pcb->ts_lastacksent = pcb->rcv_nxt;
|
|
|
-
|
|
|
- if (seg->flags & TF_SEG_OPTS_TS) {
|
|
|
- tcp_build_timestamp_option(pcb, opts);
|
|
|
- opts += 3;
|
|
|
- }
|
|
|
-#endif
|
|
|
-
|
|
|
- /* Set retransmission timer running if it is not currently enabled
|
|
|
- This must be set before checking the route. */
|
|
|
- if (pcb->rtime == -1) {
|
|
|
- pcb->rtime = 0;
|
|
|
- }
|
|
|
-
|
|
|
- /* If we don't have a local IP address, we get one by
|
|
|
- calling ip_route(). */
|
|
|
- if (ipX_addr_isany(PCB_ISIPV6(pcb), &pcb->local_ip)) {
|
|
|
- struct netif *netif;
|
|
|
- ipX_addr_t *local_ip;
|
|
|
- ipX_route_get_local_ipX(PCB_ISIPV6(pcb), &pcb->local_ip, &pcb->remote_ip, netif, local_ip);
|
|
|
- if ((netif == NULL) || (local_ip == NULL)) {
|
|
|
- return;
|
|
|
- }
|
|
|
- ipX_addr_copy(PCB_ISIPV6(pcb), pcb->local_ip, *local_ip);
|
|
|
- }
|
|
|
-
|
|
|
- if (pcb->rttest == 0) {
|
|
|
- pcb->rttest = tcp_ticks;
|
|
|
- pcb->rtseq = ntohl(seg->tcphdr->seqno);
|
|
|
-
|
|
|
- LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_output_segment: rtseq %"U32_F"\n", pcb->rtseq));
|
|
|
- }
|
|
|
- LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output_segment: %"U32_F":%"U32_F"\n",
|
|
|
- htonl(seg->tcphdr->seqno), htonl(seg->tcphdr->seqno) +
|
|
|
- seg->len));
|
|
|
-
|
|
|
- len = (u16_t)((u8_t *)seg->tcphdr - (u8_t *)seg->p->payload);
|
|
|
-
|
|
|
- seg->p->len -= len;
|
|
|
- seg->p->tot_len -= len;
|
|
|
-
|
|
|
- seg->p->payload = seg->tcphdr;
|
|
|
-
|
|
|
- seg->tcphdr->chksum = 0;
|
|
|
-#if TCP_CHECKSUM_ON_COPY
|
|
|
- {
|
|
|
- u32_t acc;
|
|
|
-#if TCP_CHECKSUM_ON_COPY_SANITY_CHECK
|
|
|
- u16_t chksum_slow = ipX_chksum_pseudo(PCB_ISIPV6(pcb), seg->p, IP_PROTO_TCP,
|
|
|
- seg->p->tot_len, &pcb->local_ip, &pcb->remote_ip);
|
|
|
-#endif /* TCP_CHECKSUM_ON_COPY_SANITY_CHECK */
|
|
|
- if ((seg->flags & TF_SEG_DATA_CHECKSUMMED) == 0) {
|
|
|
- LWIP_ASSERT("data included but not checksummed",
|
|
|
- seg->p->tot_len == (TCPH_HDRLEN(seg->tcphdr) * 4));
|
|
|
- }
|
|
|
-
|
|
|
- /* rebuild TCP header checksum (TCP header changes for retransmissions!) */
|
|
|
- acc = ipX_chksum_pseudo_partial(PCB_ISIPV6(pcb), seg->p, IP_PROTO_TCP,
|
|
|
- seg->p->tot_len, TCPH_HDRLEN(seg->tcphdr) * 4, &pcb->local_ip, &pcb->remote_ip);
|
|
|
- /* add payload checksum */
|
|
|
- if (seg->chksum_swapped) {
|
|
|
- seg->chksum = SWAP_BYTES_IN_WORD(seg->chksum);
|
|
|
- seg->chksum_swapped = 0;
|
|
|
- }
|
|
|
- acc += (u16_t)~(seg->chksum);
|
|
|
- seg->tcphdr->chksum = FOLD_U32T(acc);
|
|
|
-#if TCP_CHECKSUM_ON_COPY_SANITY_CHECK
|
|
|
- if (chksum_slow != seg->tcphdr->chksum) {
|
|
|
- LWIP_DEBUGF(TCP_DEBUG | LWIP_DBG_LEVEL_WARNING,
|
|
|
- ("tcp_output_segment: calculated checksum is %"X16_F" instead of %"X16_F"\n",
|
|
|
- seg->tcphdr->chksum, chksum_slow));
|
|
|
- seg->tcphdr->chksum = chksum_slow;
|
|
|
- }
|
|
|
-#endif /* TCP_CHECKSUM_ON_COPY_SANITY_CHECK */
|
|
|
- }
|
|
|
-#else /* TCP_CHECKSUM_ON_COPY */
|
|
|
-#if CHECKSUM_GEN_TCP
|
|
|
- seg->tcphdr->chksum = ipX_chksum_pseudo(PCB_ISIPV6(pcb), seg->p, IP_PROTO_TCP,
|
|
|
- seg->p->tot_len, &pcb->local_ip, &pcb->remote_ip);
|
|
|
-#endif /* CHECKSUM_GEN_TCP */
|
|
|
-#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
- TCP_STATS_INC(tcp.xmit);
|
|
|
-
|
|
|
-#if LWIP_NETIF_HWADDRHINT
|
|
|
- ipX_output_hinted(PCB_ISIPV6(pcb), seg->p, &pcb->local_ip, &pcb->remote_ip,
|
|
|
- pcb->ttl, pcb->tos, IP_PROTO_TCP, &pcb->addr_hint);
|
|
|
-#else /* LWIP_NETIF_HWADDRHINT*/
|
|
|
- ipX_output(PCB_ISIPV6(pcb), seg->p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl,
|
|
|
- pcb->tos, IP_PROTO_TCP);
|
|
|
-#endif /* LWIP_NETIF_HWADDRHINT*/
|
|
|
-}
|
|
|
-
|
|
|
-/**
|
|
|
- * Send a TCP RESET packet (empty segment with RST flag set) either to
|
|
|
- * abort a connection or to show that there is no matching local connection
|
|
|
- * for a received segment.
|
|
|
- *
|
|
|
- * Called by tcp_abort() (to abort a local connection), tcp_input() (if no
|
|
|
- * matching local pcb was found), tcp_listen_input() (if incoming segment
|
|
|
- * has ACK flag set) and tcp_process() (received segment in the wrong state)
|
|
|
- *
|
|
|
- * Since a RST segment is in most cases not sent for an active connection,
|
|
|
- * tcp_rst() has a number of arguments that are taken from a tcp_pcb for
|
|
|
- * most other segment output functions.
|
|
|
- *
|
|
|
- * @param seqno the sequence number to use for the outgoing segment
|
|
|
- * @param ackno the acknowledge number to use for the outgoing segment
|
|
|
- * @param local_ip the local IP address to send the segment from
|
|
|
- * @param remote_ip the remote IP address to send the segment to
|
|
|
- * @param local_port the local TCP port to send the segment from
|
|
|
- * @param remote_port the remote TCP port to send the segment to
|
|
|
- */
|
|
|
-void
|
|
|
-tcp_rst_impl(u32_t seqno, u32_t ackno,
|
|
|
- ipX_addr_t *local_ip, ipX_addr_t *remote_ip,
|
|
|
- u16_t local_port, u16_t remote_port
|
|
|
-#if LWIP_IPV6
|
|
|
- , u8_t isipv6
|
|
|
-#endif /* LWIP_IPV6 */
|
|
|
- )
|
|
|
-{
|
|
|
- struct pbuf *p;
|
|
|
- struct tcp_hdr *tcphdr;
|
|
|
- p = pbuf_alloc(PBUF_IP, TCP_HLEN, PBUF_RAM);
|
|
|
- if (p == NULL) {
|
|
|
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_rst: could not allocate memory for pbuf\n"));
|
|
|
- return;
|
|
|
- }
|
|
|
- LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr",
|
|
|
- (p->len >= sizeof(struct tcp_hdr)));
|
|
|
-
|
|
|
- tcphdr = (struct tcp_hdr *)p->payload;
|
|
|
- tcphdr->src = htons(local_port);
|
|
|
- tcphdr->dest = htons(remote_port);
|
|
|
- tcphdr->seqno = htonl(seqno);
|
|
|
- tcphdr->ackno = htonl(ackno);
|
|
|
- TCPH_HDRLEN_FLAGS_SET(tcphdr, TCP_HLEN/4, TCP_RST | TCP_ACK);
|
|
|
- tcphdr->wnd = PP_HTONS(TCP_WND);
|
|
|
- tcphdr->chksum = 0;
|
|
|
- tcphdr->urgp = 0;
|
|
|
-
|
|
|
- TCP_STATS_INC(tcp.xmit);
|
|
|
- snmp_inc_tcpoutrsts();
|
|
|
-
|
|
|
-#if CHECKSUM_GEN_TCP
|
|
|
- tcphdr->chksum = ipX_chksum_pseudo(isipv6, p, IP_PROTO_TCP, p->tot_len,
|
|
|
- local_ip, remote_ip);
|
|
|
-#endif
|
|
|
- /* Send output with hardcoded TTL/HL since we have no access to the pcb */
|
|
|
- ipX_output(isipv6, p, local_ip, remote_ip, TCP_TTL, 0, IP_PROTO_TCP);
|
|
|
- pbuf_free(p);
|
|
|
- LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_rst: seqno %"U32_F" ackno %"U32_F".\n", seqno, ackno));
|
|
|
-}
|
|
|
-
|
|
|
-/**
|
|
|
- * Requeue all unacked segments for retransmission
|
|
|
- *
|
|
|
- * Called by tcp_slowtmr() for slow retransmission.
|
|
|
- *
|
|
|
- * @param pcb the tcp_pcb for which to re-enqueue all unacked segments
|
|
|
- */
|
|
|
-void
|
|
|
-tcp_rexmit_rto(struct tcp_pcb *pcb)
|
|
|
-{
|
|
|
- struct tcp_seg *seg;
|
|
|
-
|
|
|
- if (pcb->unacked == NULL) {
|
|
|
- return;
|
|
|
- }
|
|
|
-
|
|
|
- /* Move all unacked segments to the head of the unsent queue */
|
|
|
- for (seg = pcb->unacked; seg->next != NULL; seg = seg->next);
|
|
|
- /* concatenate unsent queue after unacked queue */
|
|
|
- seg->next = pcb->unsent;
|
|
|
+/**
|
|
|
+ * @file
|
|
|
+ * Transmission Control Protocol, outgoing traffic
|
|
|
+ *
|
|
|
+ * The output functions of TCP.
|
|
|
+ *
|
|
|
+ */
|
|
|
+
|
|
|
+/*
|
|
|
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
|
|
|
+ * All rights reserved.
|
|
|
+ *
|
|
|
+ * Redistribution and use in source and binary forms, with or without modification,
|
|
|
+ * are permitted provided that the following conditions are met:
|
|
|
+ *
|
|
|
+ * 1. Redistributions of source code must retain the above copyright notice,
|
|
|
+ * this list of conditions and the following disclaimer.
|
|
|
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
|
|
|
+ * this list of conditions and the following disclaimer in the documentation
|
|
|
+ * and/or other materials provided with the distribution.
|
|
|
+ * 3. The name of the author may not be used to endorse or promote products
|
|
|
+ * derived from this software without specific prior written permission.
|
|
|
+ *
|
|
|
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
|
|
|
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
|
|
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
|
|
|
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
|
|
|
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
|
|
|
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
|
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
|
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
|
|
|
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
|
|
|
+ * OF SUCH DAMAGE.
|
|
|
+ *
|
|
|
+ * This file is part of the lwIP TCP/IP stack.
|
|
|
+ *
|
|
|
+ * Author: Adam Dunkels <adam@sics.se>
|
|
|
+ *
|
|
|
+ */
|
|
|
+
|
|
|
+#include "lwip/opt.h"
|
|
|
+
|
|
|
+#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
|
|
|
+
|
|
|
+#include "lwip/tcp_impl.h"
|
|
|
+#include "lwip/def.h"
|
|
|
+#include "lwip/mem.h"
|
|
|
+#include "lwip/memp.h"
|
|
|
+#include "lwip/ip_addr.h"
|
|
|
+#include "lwip/netif.h"
|
|
|
+#include "lwip/inet_chksum.h"
|
|
|
+#include "lwip/stats.h"
|
|
|
+#include "lwip/snmp.h"
|
|
|
+#include "lwip/ip6.h"
|
|
|
+#include "lwip/ip6_addr.h"
|
|
|
+#include "lwip/inet_chksum.h"
|
|
|
+#if LWIP_TCP_TIMESTAMPS
|
|
|
+#include "lwip/sys.h"
|
|
|
+#endif
|
|
|
+
|
|
|
+#include <string.h>
|
|
|
+
|
|
|
+/* Define some copy-macros for checksum-on-copy so that the code looks
|
|
|
+ nicer by preventing too many ifdef's. */
|
|
|
+#if TCP_CHECKSUM_ON_COPY
|
|
|
+#define TCP_DATA_COPY(dst, src, len, seg) do { \
|
|
|
+ tcp_seg_add_chksum(LWIP_CHKSUM_COPY(dst, src, len), \
|
|
|
+ len, &seg->chksum, &seg->chksum_swapped); \
|
|
|
+ seg->flags |= TF_SEG_DATA_CHECKSUMMED; } while(0)
|
|
|
+#define TCP_DATA_COPY2(dst, src, len, chksum, chksum_swapped) \
|
|
|
+ tcp_seg_add_chksum(LWIP_CHKSUM_COPY(dst, src, len), len, chksum, chksum_swapped);
|
|
|
+#else /* TCP_CHECKSUM_ON_COPY*/
|
|
|
+#define TCP_DATA_COPY(dst, src, len, seg) MEMCPY(dst, src, len)
|
|
|
+#define TCP_DATA_COPY2(dst, src, len, chksum, chksum_swapped) MEMCPY(dst, src, len)
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY*/
|
|
|
+
|
|
|
+/** Define this to 1 for an extra check that the output checksum is valid
|
|
|
+ * (usefule when the checksum is generated by the application, not the stack) */
|
|
|
+#ifndef TCP_CHECKSUM_ON_COPY_SANITY_CHECK
|
|
|
+#define TCP_CHECKSUM_ON_COPY_SANITY_CHECK 0
|
|
|
+#endif
|
|
|
+
|
|
|
+/* Forward declarations.*/
|
|
|
+static void tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb);
|
|
|
+
|
|
|
+/** Allocate a pbuf and create a tcphdr at p->payload, used for output
|
|
|
+ * functions other than the default tcp_output -> tcp_output_segment
|
|
|
+ * (e.g. tcp_send_empty_ack, etc.)
|
|
|
+ *
|
|
|
+ * @param pcb tcp pcb for which to send a packet (used to initialize tcp_hdr)
|
|
|
+ * @param optlen length of header-options
|
|
|
+ * @param datalen length of tcp data to reserve in pbuf
|
|
|
+ * @param seqno_be seqno in network byte order (big-endian)
|
|
|
+ * @return pbuf with p->payload being the tcp_hdr
|
|
|
+ */
|
|
|
+static struct pbuf *
|
|
|
+tcp_output_alloc_header(struct tcp_pcb *pcb, u16_t optlen, u16_t datalen,
|
|
|
+ u32_t seqno_be /* already in network byte order */)
|
|
|
+{
|
|
|
+ struct tcp_hdr *tcphdr;
|
|
|
+ struct pbuf *p = pbuf_alloc(PBUF_IP, TCP_HLEN + optlen + datalen, PBUF_RAM);
|
|
|
+ if (p != NULL) {
|
|
|
+ LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr",
|
|
|
+ (p->len >= TCP_HLEN + optlen));
|
|
|
+ tcphdr = (struct tcp_hdr *)p->payload;
|
|
|
+ tcphdr->src = htons(pcb->local_port);
|
|
|
+ tcphdr->dest = htons(pcb->remote_port);
|
|
|
+ tcphdr->seqno = seqno_be;
|
|
|
+ tcphdr->ackno = htonl(pcb->rcv_nxt);
|
|
|
+ TCPH_HDRLEN_FLAGS_SET(tcphdr, (5 + optlen / 4), TCP_ACK);
|
|
|
+ tcphdr->wnd = htons(RCV_WND_SCALE(pcb, pcb->rcv_ann_wnd));
|
|
|
+ tcphdr->chksum = 0;
|
|
|
+ tcphdr->urgp = 0;
|
|
|
+
|
|
|
+ /* If we're sending a packet, update the announced right window edge */
|
|
|
+ pcb->rcv_ann_right_edge = pcb->rcv_nxt + pcb->rcv_ann_wnd;
|
|
|
+ }
|
|
|
+ return p;
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * Called by tcp_close() to send a segment including FIN flag but not data.
|
|
|
+ *
|
|
|
+ * @param pcb the tcp_pcb over which to send a segment
|
|
|
+ * @return ERR_OK if sent, another err_t otherwise
|
|
|
+ */
|
|
|
+err_t
|
|
|
+tcp_send_fin(struct tcp_pcb *pcb)
|
|
|
+{
|
|
|
+ /* first, try to add the fin to the last unsent segment */
|
|
|
+ if (pcb->unsent != NULL) {
|
|
|
+ struct tcp_seg *last_unsent;
|
|
|
+ for (last_unsent = pcb->unsent; last_unsent->next != NULL;
|
|
|
+ last_unsent = last_unsent->next);
|
|
|
+
|
|
|
+ if ((TCPH_FLAGS(last_unsent->tcphdr) & (TCP_SYN | TCP_FIN | TCP_RST)) == 0) {
|
|
|
+ /* no SYN/FIN/RST flag in the header, we can add the FIN flag */
|
|
|
+ TCPH_SET_FLAG(last_unsent->tcphdr, TCP_FIN);
|
|
|
+ pcb->flags |= TF_FIN;
|
|
|
+ return ERR_OK;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ /* no data, no length, flags, copy=1, no optdata */
|
|
|
+ return tcp_enqueue_flags(pcb, TCP_FIN);
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * Create a TCP segment with prefilled header.
|
|
|
+ *
|
|
|
+ * Called by tcp_write and tcp_enqueue_flags.
|
|
|
+ *
|
|
|
+ * @param pcb Protocol control block for the TCP connection.
|
|
|
+ * @param p pbuf that is used to hold the TCP header.
|
|
|
+ * @param flags TCP flags for header.
|
|
|
+ * @param seqno TCP sequence number of this packet
|
|
|
+ * @param optflags options to include in TCP header
|
|
|
+ * @return a new tcp_seg pointing to p, or NULL.
|
|
|
+ * The TCP header is filled in except ackno and wnd.
|
|
|
+ * p is freed on failure.
|
|
|
+ */
|
|
|
+static struct tcp_seg *
|
|
|
+tcp_create_segment(struct tcp_pcb *pcb, struct pbuf *p, u8_t flags, u32_t seqno, u8_t optflags)
|
|
|
+{
|
|
|
+ struct tcp_seg *seg;
|
|
|
+ u8_t optlen = LWIP_TCP_OPT_LENGTH(optflags);
|
|
|
+
|
|
|
+ if ((seg = (struct tcp_seg *)memp_malloc(MEMP_TCP_SEG)) == NULL) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_create_segment: no memory.\n"));
|
|
|
+ pbuf_free(p);
|
|
|
+ return NULL;
|
|
|
+ }
|
|
|
+ seg->flags = optflags;
|
|
|
+ seg->next = NULL;
|
|
|
+ seg->p = p;
|
|
|
+ seg->len = p->tot_len - optlen;
|
|
|
+#if TCP_OVERSIZE_DBGCHECK
|
|
|
+ seg->oversize_left = 0;
|
|
|
+#endif /* TCP_OVERSIZE_DBGCHECK */
|
|
|
+#if TCP_CHECKSUM_ON_COPY
|
|
|
+ seg->chksum = 0;
|
|
|
+ seg->chksum_swapped = 0;
|
|
|
+ /* check optflags */
|
|
|
+ LWIP_ASSERT("invalid optflags passed: TF_SEG_DATA_CHECKSUMMED",
|
|
|
+ (optflags & TF_SEG_DATA_CHECKSUMMED) == 0);
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
+
|
|
|
+ /* build TCP header */
|
|
|
+ if (pbuf_header(p, TCP_HLEN)) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_create_segment: no room for TCP header in pbuf.\n"));
|
|
|
+ TCP_STATS_INC(tcp.err);
|
|
|
+ tcp_seg_free(seg);
|
|
|
+ return NULL;
|
|
|
+ }
|
|
|
+ seg->tcphdr = (struct tcp_hdr *)seg->p->payload;
|
|
|
+ seg->tcphdr->src = htons(pcb->local_port);
|
|
|
+ seg->tcphdr->dest = htons(pcb->remote_port);
|
|
|
+ seg->tcphdr->seqno = htonl(seqno);
|
|
|
+ /* ackno is set in tcp_output */
|
|
|
+ TCPH_HDRLEN_FLAGS_SET(seg->tcphdr, (5 + optlen / 4), flags);
|
|
|
+ /* wnd and chksum are set in tcp_output */
|
|
|
+ seg->tcphdr->urgp = 0;
|
|
|
+ return seg;
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * Allocate a PBUF_RAM pbuf, perhaps with extra space at the end.
|
|
|
+ *
|
|
|
+ * This function is like pbuf_alloc(layer, length, PBUF_RAM) except
|
|
|
+ * there may be extra bytes available at the end.
|
|
|
+ *
|
|
|
+ * @param layer flag to define header size.
|
|
|
+ * @param length size of the pbuf's payload.
|
|
|
+ * @param max_length maximum usable size of payload+oversize.
|
|
|
+ * @param oversize pointer to a u16_t that will receive the number of usable tail bytes.
|
|
|
+ * @param pcb The TCP connection that willo enqueue the pbuf.
|
|
|
+ * @param apiflags API flags given to tcp_write.
|
|
|
+ * @param first_seg true when this pbuf will be used in the first enqueued segment.
|
|
|
+ * @param
|
|
|
+ */
|
|
|
+#if TCP_OVERSIZE
|
|
|
+static struct pbuf *
|
|
|
+tcp_pbuf_prealloc(pbuf_layer layer, u16_t length, u16_t max_length,
|
|
|
+ u16_t *oversize, struct tcp_pcb *pcb, u8_t apiflags,
|
|
|
+ u8_t first_seg)
|
|
|
+{
|
|
|
+ struct pbuf *p;
|
|
|
+ u16_t alloc = length;
|
|
|
+
|
|
|
+#if LWIP_NETIF_TX_SINGLE_PBUF
|
|
|
+ LWIP_UNUSED_ARG(max_length);
|
|
|
+ LWIP_UNUSED_ARG(pcb);
|
|
|
+ LWIP_UNUSED_ARG(apiflags);
|
|
|
+ LWIP_UNUSED_ARG(first_seg);
|
|
|
+ /* always create MSS-sized pbufs */
|
|
|
+ alloc = max_length;
|
|
|
+#else /* LWIP_NETIF_TX_SINGLE_PBUF */
|
|
|
+ if (length < max_length) {
|
|
|
+ /* Should we allocate an oversized pbuf, or just the minimum
|
|
|
+ * length required? If tcp_write is going to be called again
|
|
|
+ * before this segment is transmitted, we want the oversized
|
|
|
+ * buffer. If the segment will be transmitted immediately, we can
|
|
|
+ * save memory by allocating only length. We use a simple
|
|
|
+ * heuristic based on the following information:
|
|
|
+ *
|
|
|
+ * Did the user set TCP_WRITE_FLAG_MORE?
|
|
|
+ *
|
|
|
+ * Will the Nagle algorithm defer transmission of this segment?
|
|
|
+ */
|
|
|
+ if ((apiflags & TCP_WRITE_FLAG_MORE) ||
|
|
|
+ (!(pcb->flags & TF_NODELAY) &&
|
|
|
+ (!first_seg ||
|
|
|
+ pcb->unsent != NULL ||
|
|
|
+ pcb->unacked != NULL))) {
|
|
|
+ alloc = LWIP_MIN(max_length, LWIP_MEM_ALIGN_SIZE(length + TCP_OVERSIZE));
|
|
|
+ }
|
|
|
+ }
|
|
|
+#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
|
|
|
+ p = pbuf_alloc(layer, alloc, PBUF_RAM);
|
|
|
+ if (p == NULL) {
|
|
|
+ return NULL;
|
|
|
+ }
|
|
|
+ LWIP_ASSERT("need unchained pbuf", p->next == NULL);
|
|
|
+ *oversize = p->len - length;
|
|
|
+ /* trim p->len to the currently used size */
|
|
|
+ p->len = p->tot_len = length;
|
|
|
+ return p;
|
|
|
+}
|
|
|
+#else /* TCP_OVERSIZE */
|
|
|
+#define tcp_pbuf_prealloc(layer, length, mx, os, pcb, api, fst) pbuf_alloc((layer), (length), PBUF_RAM)
|
|
|
+#endif /* TCP_OVERSIZE */
|
|
|
+
|
|
|
+#if TCP_CHECKSUM_ON_COPY
|
|
|
+/** Add a checksum of newly added data to the segment */
|
|
|
+static void
|
|
|
+tcp_seg_add_chksum(u16_t chksum, u16_t len, u16_t *seg_chksum,
|
|
|
+ u8_t *seg_chksum_swapped)
|
|
|
+{
|
|
|
+ u32_t helper;
|
|
|
+ /* add chksum to old chksum and fold to u16_t */
|
|
|
+ helper = chksum + *seg_chksum;
|
|
|
+ chksum = FOLD_U32T(helper);
|
|
|
+ if ((len & 1) != 0) {
|
|
|
+ *seg_chksum_swapped = 1 - *seg_chksum_swapped;
|
|
|
+ chksum = SWAP_BYTES_IN_WORD(chksum);
|
|
|
+ }
|
|
|
+ *seg_chksum = chksum;
|
|
|
+}
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
+
|
|
|
+/** Checks if tcp_write is allowed or not (checks state, snd_buf and snd_queuelen).
|
|
|
+ *
|
|
|
+ * @param pcb the tcp pcb to check for
|
|
|
+ * @param len length of data to send (checked agains snd_buf)
|
|
|
+ * @return ERR_OK if tcp_write is allowed to proceed, another err_t otherwise
|
|
|
+ */
|
|
|
+static err_t
|
|
|
+tcp_write_checks(struct tcp_pcb *pcb, u16_t len)
|
|
|
+{
|
|
|
+ /* connection is in invalid state for data transmission? */
|
|
|
+ if ((pcb->state != ESTABLISHED) &&
|
|
|
+ (pcb->state != CLOSE_WAIT) &&
|
|
|
+ (pcb->state != SYN_SENT) &&
|
|
|
+ (pcb->state != SYN_RCVD)) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_STATE | LWIP_DBG_LEVEL_SEVERE, ("tcp_write() called in invalid state\n"));
|
|
|
+ return ERR_CONN;
|
|
|
+ } else if (len == 0) {
|
|
|
+ return ERR_OK;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* fail on too much data */
|
|
|
+ if (len > pcb->snd_buf) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too much data (len=%"U16_F" > snd_buf=%"U16_F")\n",
|
|
|
+ len, pcb->snd_buf));
|
|
|
+ pcb->flags |= TF_NAGLEMEMERR;
|
|
|
+ return ERR_MEM;
|
|
|
+ }
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: queuelen: %"TCPWNDSIZE_F"\n", (tcpwnd_size_t)pcb->snd_queuelen));
|
|
|
+
|
|
|
+ /* If total number of pbufs on the unsent/unacked queues exceeds the
|
|
|
+ * configured maximum, return an error */
|
|
|
+ /* check for configured max queuelen and possible overflow */
|
|
|
+ if ((pcb->snd_queuelen >= TCP_SND_QUEUELEN) || (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too long queue %"TCPWNDSIZE_F" (max %"TCPWNDSIZE_F")\n",
|
|
|
+ pcb->snd_queuelen, TCP_SND_QUEUELEN));
|
|
|
+ TCP_STATS_INC(tcp.memerr);
|
|
|
+ pcb->flags |= TF_NAGLEMEMERR;
|
|
|
+ return ERR_MEM;
|
|
|
+ }
|
|
|
+ if (pcb->snd_queuelen != 0) {
|
|
|
+ LWIP_ASSERT("tcp_write: pbufs on queue => at least one queue non-empty",
|
|
|
+ pcb->unacked != NULL || pcb->unsent != NULL);
|
|
|
+ } else {
|
|
|
+ LWIP_ASSERT("tcp_write: no pbufs on queue => both queues empty",
|
|
|
+ pcb->unacked == NULL && pcb->unsent == NULL);
|
|
|
+ }
|
|
|
+ return ERR_OK;
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * Write data for sending (but does not send it immediately).
|
|
|
+ *
|
|
|
+ * It waits in the expectation of more data being sent soon (as
|
|
|
+ * it can send them more efficiently by combining them together).
|
|
|
+ * To prompt the system to send data now, call tcp_output() after
|
|
|
+ * calling tcp_write().
|
|
|
+ *
|
|
|
+ * @param pcb Protocol control block for the TCP connection to enqueue data for.
|
|
|
+ * @param arg Pointer to the data to be enqueued for sending.
|
|
|
+ * @param len Data length in bytes
|
|
|
+ * @param apiflags combination of following flags :
|
|
|
+ * - TCP_WRITE_FLAG_COPY (0x01) data will be copied into memory belonging to the stack
|
|
|
+ * - TCP_WRITE_FLAG_MORE (0x02) for TCP connection, PSH flag will be set on last segment sent,
|
|
|
+ * @return ERR_OK if enqueued, another err_t on error
|
|
|
+ */
|
|
|
+err_t
|
|
|
+tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
|
|
|
+{
|
|
|
+ struct pbuf *concat_p = NULL;
|
|
|
+ struct tcp_seg *last_unsent = NULL, *seg = NULL, *prev_seg = NULL, *queue = NULL;
|
|
|
+ u16_t pos = 0; /* position in 'arg' data */
|
|
|
+ u16_t queuelen;
|
|
|
+ u8_t optlen = 0;
|
|
|
+ u8_t optflags = 0;
|
|
|
+#if TCP_OVERSIZE
|
|
|
+ u16_t oversize = 0;
|
|
|
+ u16_t oversize_used = 0;
|
|
|
+#endif /* TCP_OVERSIZE */
|
|
|
+#if TCP_CHECKSUM_ON_COPY
|
|
|
+ u16_t concat_chksum = 0;
|
|
|
+ u8_t concat_chksum_swapped = 0;
|
|
|
+ u16_t concat_chksummed = 0;
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
+ err_t err;
|
|
|
+ /* don't allocate segments bigger than half the maximum window we ever received */
|
|
|
+ u16_t mss_local = LWIP_MIN(pcb->mss, pcb->snd_wnd_max/2);
|
|
|
+
|
|
|
+#if LWIP_NETIF_TX_SINGLE_PBUF
|
|
|
+ /* Always copy to try to create single pbufs for TX */
|
|
|
+ apiflags |= TCP_WRITE_FLAG_COPY;
|
|
|
+#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_write(pcb=%p, data=%p, len=%"U16_F", apiflags=%"U16_F")\n",
|
|
|
+ (void *)pcb, arg, len, (u16_t)apiflags));
|
|
|
+ LWIP_ERROR("tcp_write: arg == NULL (programmer violates API)",
|
|
|
+ arg != NULL, return ERR_ARG;);
|
|
|
+
|
|
|
+ err = tcp_write_checks(pcb, len);
|
|
|
+ if (err != ERR_OK) {
|
|
|
+ return err;
|
|
|
+ }
|
|
|
+ queuelen = pcb->snd_queuelen;
|
|
|
+
|
|
|
+#if LWIP_TCP_TIMESTAMPS
|
|
|
+ if ((pcb->flags & TF_TIMESTAMP)) {
|
|
|
+ optflags = TF_SEG_OPTS_TS;
|
|
|
+ optlen = LWIP_TCP_OPT_LENGTH(TF_SEG_OPTS_TS);
|
|
|
+ }
|
|
|
+#endif /* LWIP_TCP_TIMESTAMPS */
|
|
|
+
|
|
|
+
|
|
|
+ /*
|
|
|
+ * TCP segmentation is done in three phases with increasing complexity:
|
|
|
+ *
|
|
|
+ * 1. Copy data directly into an oversized pbuf.
|
|
|
+ * 2. Chain a new pbuf to the end of pcb->unsent.
|
|
|
+ * 3. Create new segments.
|
|
|
+ *
|
|
|
+ * We may run out of memory at any point. In that case we must
|
|
|
+ * return ERR_MEM and not change anything in pcb. Therefore, all
|
|
|
+ * changes are recorded in local variables and committed at the end
|
|
|
+ * of the function. Some pcb fields are maintained in local copies:
|
|
|
+ *
|
|
|
+ * queuelen = pcb->snd_queuelen
|
|
|
+ * oversize = pcb->unsent_oversize
|
|
|
+ *
|
|
|
+ * These variables are set consistently by the phases:
|
|
|
+ *
|
|
|
+ * seg points to the last segment tampered with.
|
|
|
+ *
|
|
|
+ * pos records progress as data is segmented.
|
|
|
+ */
|
|
|
+
|
|
|
+ /* Find the tail of the unsent queue. */
|
|
|
+ if (pcb->unsent != NULL) {
|
|
|
+ u16_t space;
|
|
|
+ u16_t unsent_optlen;
|
|
|
+
|
|
|
+ /* @todo: this could be sped up by keeping last_unsent in the pcb */
|
|
|
+ for (last_unsent = pcb->unsent; last_unsent->next != NULL;
|
|
|
+ last_unsent = last_unsent->next);
|
|
|
+
|
|
|
+ /* Usable space at the end of the last unsent segment */
|
|
|
+ unsent_optlen = LWIP_TCP_OPT_LENGTH(last_unsent->flags);
|
|
|
+ space = mss_local - (last_unsent->len + unsent_optlen);
|
|
|
+
|
|
|
+ /*
|
|
|
+ * Phase 1: Copy data directly into an oversized pbuf.
|
|
|
+ *
|
|
|
+ * The number of bytes copied is recorded in the oversize_used
|
|
|
+ * variable. The actual copying is done at the bottom of the
|
|
|
+ * function.
|
|
|
+ */
|
|
|
+#if TCP_OVERSIZE
|
|
|
+#if TCP_OVERSIZE_DBGCHECK
|
|
|
+ /* check that pcb->unsent_oversize matches last_unsent->unsent_oversize */
|
|
|
+ LWIP_ASSERT("unsent_oversize mismatch (pcb vs. last_unsent)",
|
|
|
+ pcb->unsent_oversize == last_unsent->oversize_left);
|
|
|
+#endif /* TCP_OVERSIZE_DBGCHECK */
|
|
|
+ oversize = pcb->unsent_oversize;
|
|
|
+ if (oversize > 0) {
|
|
|
+ LWIP_ASSERT("inconsistent oversize vs. space", oversize_used <= space);
|
|
|
+ seg = last_unsent;
|
|
|
+ oversize_used = oversize < len ? oversize : len;
|
|
|
+ pos += oversize_used;
|
|
|
+ oversize -= oversize_used;
|
|
|
+ space -= oversize_used;
|
|
|
+ }
|
|
|
+ /* now we are either finished or oversize is zero */
|
|
|
+ LWIP_ASSERT("inconsistend oversize vs. len", (oversize == 0) || (pos == len));
|
|
|
+#endif /* TCP_OVERSIZE */
|
|
|
+
|
|
|
+ /*
|
|
|
+ * Phase 2: Chain a new pbuf to the end of pcb->unsent.
|
|
|
+ *
|
|
|
+ * We don't extend segments containing SYN/FIN flags or options
|
|
|
+ * (len==0). The new pbuf is kept in concat_p and pbuf_cat'ed at
|
|
|
+ * the end.
|
|
|
+ */
|
|
|
+ if ((pos < len) && (space > 0) && (last_unsent->len > 0)) {
|
|
|
+ u16_t seglen = space < len - pos ? space : len - pos;
|
|
|
+ seg = last_unsent;
|
|
|
+
|
|
|
+ /* Create a pbuf with a copy or reference to seglen bytes. We
|
|
|
+ * can use PBUF_RAW here since the data appears in the middle of
|
|
|
+ * a segment. A header will never be prepended. */
|
|
|
+ if (apiflags & TCP_WRITE_FLAG_COPY) {
|
|
|
+ /* Data is copied */
|
|
|
+ if ((concat_p = tcp_pbuf_prealloc(PBUF_RAW, seglen, space, &oversize, pcb, apiflags, 1)) == NULL) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2,
|
|
|
+ ("tcp_write : could not allocate memory for pbuf copy size %"U16_F"\n",
|
|
|
+ seglen));
|
|
|
+ goto memerr;
|
|
|
+ }
|
|
|
+#if TCP_OVERSIZE_DBGCHECK
|
|
|
+ last_unsent->oversize_left += oversize;
|
|
|
+#endif /* TCP_OVERSIZE_DBGCHECK */
|
|
|
+ TCP_DATA_COPY2(concat_p->payload, (u8_t*)arg + pos, seglen, &concat_chksum, &concat_chksum_swapped);
|
|
|
+#if TCP_CHECKSUM_ON_COPY
|
|
|
+ concat_chksummed += seglen;
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
+ } else {
|
|
|
+ /* Data is not copied */
|
|
|
+ if ((concat_p = pbuf_alloc(PBUF_RAW, seglen, PBUF_ROM)) == NULL) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2,
|
|
|
+ ("tcp_write: could not allocate memory for zero-copy pbuf\n"));
|
|
|
+ goto memerr;
|
|
|
+ }
|
|
|
+#if TCP_CHECKSUM_ON_COPY
|
|
|
+ /* calculate the checksum of nocopy-data */
|
|
|
+ tcp_seg_add_chksum(~inet_chksum((u8_t*)arg + pos, seglen), seglen,
|
|
|
+ &concat_chksum, &concat_chksum_swapped);
|
|
|
+ concat_chksummed += seglen;
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
+ /* reference the non-volatile payload data */
|
|
|
+ concat_p->payload = (u8_t*)arg + pos;
|
|
|
+ }
|
|
|
+
|
|
|
+ pos += seglen;
|
|
|
+ queuelen += pbuf_clen(concat_p);
|
|
|
+ }
|
|
|
+ } else {
|
|
|
+#if TCP_OVERSIZE
|
|
|
+ LWIP_ASSERT("unsent_oversize mismatch (pcb->unsent is NULL)",
|
|
|
+ pcb->unsent_oversize == 0);
|
|
|
+#endif /* TCP_OVERSIZE */
|
|
|
+ }
|
|
|
+
|
|
|
+ /*
|
|
|
+ * Phase 3: Create new segments.
|
|
|
+ *
|
|
|
+ * The new segments are chained together in the local 'queue'
|
|
|
+ * variable, ready to be appended to pcb->unsent.
|
|
|
+ */
|
|
|
+ while (pos < len) {
|
|
|
+ struct pbuf *p;
|
|
|
+ u16_t left = len - pos;
|
|
|
+ u16_t max_len = mss_local - optlen;
|
|
|
+ u16_t seglen = left > max_len ? max_len : left;
|
|
|
+#if TCP_CHECKSUM_ON_COPY
|
|
|
+ u16_t chksum = 0;
|
|
|
+ u8_t chksum_swapped = 0;
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
+
|
|
|
+ if (apiflags & TCP_WRITE_FLAG_COPY) {
|
|
|
+ /* If copy is set, memory should be allocated and data copied
|
|
|
+ * into pbuf */
|
|
|
+ if ((p = tcp_pbuf_prealloc(PBUF_TRANSPORT, seglen + optlen, mss_local, &oversize, pcb, apiflags, queue == NULL)) == NULL) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write : could not allocate memory for pbuf copy size %"U16_F"\n", seglen));
|
|
|
+ goto memerr;
|
|
|
+ }
|
|
|
+ LWIP_ASSERT("tcp_write: check that first pbuf can hold the complete seglen",
|
|
|
+ (p->len >= seglen));
|
|
|
+ TCP_DATA_COPY2((char *)p->payload + optlen, (u8_t*)arg + pos, seglen, &chksum, &chksum_swapped);
|
|
|
+ } else {
|
|
|
+ /* Copy is not set: First allocate a pbuf for holding the data.
|
|
|
+ * Since the referenced data is available at least until it is
|
|
|
+ * sent out on the link (as it has to be ACKed by the remote
|
|
|
+ * party) we can safely use PBUF_ROM instead of PBUF_REF here.
|
|
|
+ */
|
|
|
+ struct pbuf *p2;
|
|
|
+#if TCP_OVERSIZE
|
|
|
+ LWIP_ASSERT("oversize == 0", oversize == 0);
|
|
|
+#endif /* TCP_OVERSIZE */
|
|
|
+ if ((p2 = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_ROM)) == NULL) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: could not allocate memory for zero-copy pbuf\n"));
|
|
|
+ goto memerr;
|
|
|
+ }
|
|
|
+#if TCP_CHECKSUM_ON_COPY
|
|
|
+ /* calculate the checksum of nocopy-data */
|
|
|
+ chksum = ~inet_chksum((u8_t*)arg + pos, seglen);
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
+ /* reference the non-volatile payload data */
|
|
|
+ p2->payload = (u8_t*)arg + pos;
|
|
|
+
|
|
|
+ /* Second, allocate a pbuf for the headers. */
|
|
|
+ if ((p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) {
|
|
|
+ /* If allocation fails, we have to deallocate the data pbuf as
|
|
|
+ * well. */
|
|
|
+ pbuf_free(p2);
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: could not allocate memory for header pbuf\n"));
|
|
|
+ goto memerr;
|
|
|
+ }
|
|
|
+ /* Concatenate the headers and data pbufs together. */
|
|
|
+ pbuf_cat(p/*header*/, p2/*data*/);
|
|
|
+ }
|
|
|
+
|
|
|
+ queuelen += pbuf_clen(p);
|
|
|
+
|
|
|
+ /* Now that there are more segments queued, we check again if the
|
|
|
+ * length of the queue exceeds the configured maximum or
|
|
|
+ * overflows. */
|
|
|
+ if ((queuelen > TCP_SND_QUEUELEN) || (queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: queue too long %"TCPWNDSIZE_F" (%"TCPWNDSIZE_F")\n", queuelen, TCP_SND_QUEUELEN));
|
|
|
+ pbuf_free(p);
|
|
|
+ goto memerr;
|
|
|
+ }
|
|
|
+
|
|
|
+ if ((seg = tcp_create_segment(pcb, p, 0, pcb->snd_lbb + pos, optflags)) == NULL) {
|
|
|
+ goto memerr;
|
|
|
+ }
|
|
|
+#if TCP_OVERSIZE_DBGCHECK
|
|
|
+ seg->oversize_left = oversize;
|
|
|
+#endif /* TCP_OVERSIZE_DBGCHECK */
|
|
|
+#if TCP_CHECKSUM_ON_COPY
|
|
|
+ seg->chksum = chksum;
|
|
|
+ seg->chksum_swapped = chksum_swapped;
|
|
|
+ seg->flags |= TF_SEG_DATA_CHECKSUMMED;
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
+
|
|
|
+ /* first segment of to-be-queued data? */
|
|
|
+ if (queue == NULL) {
|
|
|
+ queue = seg;
|
|
|
+ } else {
|
|
|
+ /* Attach the segment to the end of the queued segments */
|
|
|
+ LWIP_ASSERT("prev_seg != NULL", prev_seg != NULL);
|
|
|
+ prev_seg->next = seg;
|
|
|
+ }
|
|
|
+ /* remember last segment of to-be-queued data for next iteration */
|
|
|
+ prev_seg = seg;
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_TRACE, ("tcp_write: queueing %"U32_F":%"U32_F"\n",
|
|
|
+ ntohl(seg->tcphdr->seqno),
|
|
|
+ ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg)));
|
|
|
+
|
|
|
+ pos += seglen;
|
|
|
+ }
|
|
|
+
|
|
|
+ /*
|
|
|
+ * All three segmentation phases were successful. We can commit the
|
|
|
+ * transaction.
|
|
|
+ */
|
|
|
+
|
|
|
+ /*
|
|
|
+ * Phase 1: If data has been added to the preallocated tail of
|
|
|
+ * last_unsent, we update the length fields of the pbuf chain.
|
|
|
+ */
|
|
|
+#if TCP_OVERSIZE
|
|
|
+ if (oversize_used > 0) {
|
|
|
+ struct pbuf *p;
|
|
|
+ /* Bump tot_len of whole chain, len of tail */
|
|
|
+ for (p = last_unsent->p; p; p = p->next) {
|
|
|
+ p->tot_len += oversize_used;
|
|
|
+ if (p->next == NULL) {
|
|
|
+ TCP_DATA_COPY((char *)p->payload + p->len, arg, oversize_used, last_unsent);
|
|
|
+ p->len += oversize_used;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ last_unsent->len += oversize_used;
|
|
|
+#if TCP_OVERSIZE_DBGCHECK
|
|
|
+ LWIP_ASSERT("last_unsent->oversize_left >= oversize_used",
|
|
|
+ last_unsent->oversize_left >= oversize_used);
|
|
|
+ last_unsent->oversize_left -= oversize_used;
|
|
|
+#endif /* TCP_OVERSIZE_DBGCHECK */
|
|
|
+ }
|
|
|
+ pcb->unsent_oversize = oversize;
|
|
|
+#endif /* TCP_OVERSIZE */
|
|
|
+
|
|
|
+ /*
|
|
|
+ * Phase 2: concat_p can be concatenated onto last_unsent->p
|
|
|
+ */
|
|
|
+ if (concat_p != NULL) {
|
|
|
+ LWIP_ASSERT("tcp_write: cannot concatenate when pcb->unsent is empty",
|
|
|
+ (last_unsent != NULL));
|
|
|
+ pbuf_cat(last_unsent->p, concat_p);
|
|
|
+ last_unsent->len += concat_p->tot_len;
|
|
|
+#if TCP_CHECKSUM_ON_COPY
|
|
|
+ if (concat_chksummed) {
|
|
|
+ tcp_seg_add_chksum(concat_chksum, concat_chksummed, &last_unsent->chksum,
|
|
|
+ &last_unsent->chksum_swapped);
|
|
|
+ last_unsent->flags |= TF_SEG_DATA_CHECKSUMMED;
|
|
|
+ }
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
+ }
|
|
|
+
|
|
|
+ /*
|
|
|
+ * Phase 3: Append queue to pcb->unsent. Queue may be NULL, but that
|
|
|
+ * is harmless
|
|
|
+ */
|
|
|
+ if (last_unsent == NULL) {
|
|
|
+ pcb->unsent = queue;
|
|
|
+ } else {
|
|
|
+ last_unsent->next = queue;
|
|
|
+ }
|
|
|
+
|
|
|
+ /*
|
|
|
+ * Finally update the pcb state.
|
|
|
+ */
|
|
|
+ pcb->snd_lbb += len;
|
|
|
+ pcb->snd_buf -= len;
|
|
|
+ pcb->snd_queuelen = queuelen;
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: %"S16_F" (after enqueued)\n",
|
|
|
+ pcb->snd_queuelen));
|
|
|
+ if (pcb->snd_queuelen != 0) {
|
|
|
+ LWIP_ASSERT("tcp_write: valid queue length",
|
|
|
+ pcb->unacked != NULL || pcb->unsent != NULL);
|
|
|
+ }
|
|
|
+
|
|
|
+ /* Set the PSH flag in the last segment that we enqueued. */
|
|
|
+ if (seg != NULL && seg->tcphdr != NULL && ((apiflags & TCP_WRITE_FLAG_MORE)==0)) {
|
|
|
+ TCPH_SET_FLAG(seg->tcphdr, TCP_PSH);
|
|
|
+ }
|
|
|
+
|
|
|
+ return ERR_OK;
|
|
|
+memerr:
|
|
|
+ pcb->flags |= TF_NAGLEMEMERR;
|
|
|
+ TCP_STATS_INC(tcp.memerr);
|
|
|
+
|
|
|
+ if (concat_p != NULL) {
|
|
|
+ pbuf_free(concat_p);
|
|
|
+ }
|
|
|
+ if (queue != NULL) {
|
|
|
+ tcp_segs_free(queue);
|
|
|
+ }
|
|
|
+ if (pcb->snd_queuelen != 0) {
|
|
|
+ LWIP_ASSERT("tcp_write: valid queue length", pcb->unacked != NULL ||
|
|
|
+ pcb->unsent != NULL);
|
|
|
+ }
|
|
|
+ LWIP_DEBUGF(TCP_QLEN_DEBUG | LWIP_DBG_STATE, ("tcp_write: %"S16_F" (with mem err)\n", pcb->snd_queuelen));
|
|
|
+ return ERR_MEM;
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * Enqueue TCP options for transmission.
|
|
|
+ *
|
|
|
+ * Called by tcp_connect(), tcp_listen_input(), and tcp_send_ctrl().
|
|
|
+ *
|
|
|
+ * @param pcb Protocol control block for the TCP connection.
|
|
|
+ * @param flags TCP header flags to set in the outgoing segment.
|
|
|
+ * @param optdata pointer to TCP options, or NULL.
|
|
|
+ * @param optlen length of TCP options in bytes.
|
|
|
+ */
|
|
|
+err_t
|
|
|
+tcp_enqueue_flags(struct tcp_pcb *pcb, u8_t flags)
|
|
|
+{
|
|
|
+ struct pbuf *p;
|
|
|
+ struct tcp_seg *seg;
|
|
|
+ u8_t optflags = 0;
|
|
|
+ u8_t optlen = 0;
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue_flags: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen));
|
|
|
+
|
|
|
+ LWIP_ASSERT("tcp_enqueue_flags: need either TCP_SYN or TCP_FIN in flags (programmer violates API)",
|
|
|
+ (flags & (TCP_SYN | TCP_FIN)) != 0);
|
|
|
+
|
|
|
+ /* check for configured max queuelen and possible overflow */
|
|
|
+ if ((pcb->snd_queuelen >= TCP_SND_QUEUELEN) || (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_enqueue_flags: too long queue %"U16_F" (max %"U16_F")\n",
|
|
|
+ pcb->snd_queuelen, TCP_SND_QUEUELEN));
|
|
|
+ TCP_STATS_INC(tcp.memerr);
|
|
|
+ pcb->flags |= TF_NAGLEMEMERR;
|
|
|
+ return ERR_MEM;
|
|
|
+ }
|
|
|
+
|
|
|
+ if (flags & TCP_SYN) {
|
|
|
+ optflags = TF_SEG_OPTS_MSS;
|
|
|
+#if LWIP_WND_SCALE
|
|
|
+ if ((pcb->state != SYN_RCVD) || (pcb->flags & TF_WND_SCALE)) {
|
|
|
+ /* In a <SYN,ACK> (sent in state SYN_RCVD), the window scale option may only
|
|
|
+ be sent if we received a window scale option from the remote host. */
|
|
|
+ optflags |= TF_SEG_OPTS_WND_SCALE;
|
|
|
+ }
|
|
|
+#endif /* LWIP_WND_SCALE */
|
|
|
+ }
|
|
|
+#if LWIP_TCP_TIMESTAMPS
|
|
|
+ if ((pcb->flags & TF_TIMESTAMP)) {
|
|
|
+ optflags |= TF_SEG_OPTS_TS;
|
|
|
+ }
|
|
|
+#endif /* LWIP_TCP_TIMESTAMPS */
|
|
|
+ optlen = LWIP_TCP_OPT_LENGTH(optflags);
|
|
|
+
|
|
|
+ /* tcp_enqueue_flags is always called with either SYN or FIN in flags.
|
|
|
+ * We need one available snd_buf byte to do that.
|
|
|
+ * This means we can't send FIN while snd_buf==0. A better fix would be to
|
|
|
+ * not include SYN and FIN sequence numbers in the snd_buf count. */
|
|
|
+ if (pcb->snd_buf == 0) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_enqueue_flags: no send buffer available\n"));
|
|
|
+ TCP_STATS_INC(tcp.memerr);
|
|
|
+ return ERR_MEM;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* Allocate pbuf with room for TCP header + options */
|
|
|
+ if ((p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) {
|
|
|
+ pcb->flags |= TF_NAGLEMEMERR;
|
|
|
+ TCP_STATS_INC(tcp.memerr);
|
|
|
+ return ERR_MEM;
|
|
|
+ }
|
|
|
+ LWIP_ASSERT("tcp_enqueue_flags: check that first pbuf can hold optlen",
|
|
|
+ (p->len >= optlen));
|
|
|
+
|
|
|
+ /* Allocate memory for tcp_seg, and fill in fields. */
|
|
|
+ if ((seg = tcp_create_segment(pcb, p, flags, pcb->snd_lbb, optflags)) == NULL) {
|
|
|
+ pcb->flags |= TF_NAGLEMEMERR;
|
|
|
+ TCP_STATS_INC(tcp.memerr);
|
|
|
+ return ERR_MEM;
|
|
|
+ }
|
|
|
+ LWIP_ASSERT("seg->tcphdr not aligned", ((mem_ptr_t)seg->tcphdr % MEM_ALIGNMENT) == 0);
|
|
|
+ LWIP_ASSERT("tcp_enqueue_flags: invalid segment length", seg->len == 0);
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_TRACE,
|
|
|
+ ("tcp_enqueue_flags: queueing %"U32_F":%"U32_F" (0x%"X16_F")\n",
|
|
|
+ ntohl(seg->tcphdr->seqno),
|
|
|
+ ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg),
|
|
|
+ (u16_t)flags));
|
|
|
+
|
|
|
+ /* Now append seg to pcb->unsent queue */
|
|
|
+ if (pcb->unsent == NULL) {
|
|
|
+ pcb->unsent = seg;
|
|
|
+ } else {
|
|
|
+ struct tcp_seg *useg;
|
|
|
+ for (useg = pcb->unsent; useg->next != NULL; useg = useg->next);
|
|
|
+ useg->next = seg;
|
|
|
+ }
|
|
|
+#if TCP_OVERSIZE
|
|
|
+ /* The new unsent tail has no space */
|
|
|
+ pcb->unsent_oversize = 0;
|
|
|
+#endif /* TCP_OVERSIZE */
|
|
|
+
|
|
|
+ /* SYN and FIN bump the sequence number */
|
|
|
+ if ((flags & TCP_SYN) || (flags & TCP_FIN)) {
|
|
|
+ pcb->snd_lbb++;
|
|
|
+ /* optlen does not influence snd_buf */
|
|
|
+ pcb->snd_buf--;
|
|
|
+ }
|
|
|
+ if (flags & TCP_FIN) {
|
|
|
+ pcb->flags |= TF_FIN;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* update number of segments on the queues */
|
|
|
+ pcb->snd_queuelen += pbuf_clen(seg->p);
|
|
|
+ LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue_flags: %"S16_F" (after enqueued)\n", pcb->snd_queuelen));
|
|
|
+ if (pcb->snd_queuelen != 0) {
|
|
|
+ LWIP_ASSERT("tcp_enqueue_flags: invalid queue length",
|
|
|
+ pcb->unacked != NULL || pcb->unsent != NULL);
|
|
|
+ }
|
|
|
+
|
|
|
+ return ERR_OK;
|
|
|
+}
|
|
|
+
|
|
|
+#if LWIP_TCP_TIMESTAMPS
|
|
|
+/* Build a timestamp option (12 bytes long) at the specified options pointer)
|
|
|
+ *
|
|
|
+ * @param pcb tcp_pcb
|
|
|
+ * @param opts option pointer where to store the timestamp option
|
|
|
+ */
|
|
|
+static void
|
|
|
+tcp_build_timestamp_option(struct tcp_pcb *pcb, u32_t *opts)
|
|
|
+{
|
|
|
+ /* Pad with two NOP options to make everything nicely aligned */
|
|
|
+ opts[0] = PP_HTONL(0x0101080A);
|
|
|
+ opts[1] = htonl(sys_now());
|
|
|
+ opts[2] = htonl(pcb->ts_recent);
|
|
|
+}
|
|
|
+#endif
|
|
|
+
|
|
|
+#if LWIP_WND_SCALE
|
|
|
+/** Build a window scale option (3 bytes long) at the specified options pointer)
|
|
|
+ *
|
|
|
+ * @param opts option pointer where to store the window scale option
|
|
|
+ */
|
|
|
+static void
|
|
|
+tcp_build_wnd_scale_option(u32_t *opts)
|
|
|
+{
|
|
|
+ /* Pad with one NOP option to make everything nicely aligned */
|
|
|
+ opts[0] = PP_HTONL(0x01030300 | TCP_RCV_SCALE);
|
|
|
+}
|
|
|
+#endif
|
|
|
+
|
|
|
+/** Send an ACK without data.
|
|
|
+ *
|
|
|
+ * @param pcb Protocol control block for the TCP connection to send the ACK
|
|
|
+ */
|
|
|
+err_t
|
|
|
+tcp_send_empty_ack(struct tcp_pcb *pcb)
|
|
|
+{
|
|
|
+ struct pbuf *p;
|
|
|
+ u8_t optlen = 0;
|
|
|
+#if LWIP_TCP_TIMESTAMPS || CHECKSUM_GEN_TCP
|
|
|
+ struct tcp_hdr *tcphdr;
|
|
|
+#endif /* LWIP_TCP_TIMESTAMPS || CHECKSUM_GEN_TCP */
|
|
|
+
|
|
|
+#if LWIP_TCP_TIMESTAMPS
|
|
|
+ if (pcb->flags & TF_TIMESTAMP) {
|
|
|
+ optlen = LWIP_TCP_OPT_LENGTH(TF_SEG_OPTS_TS);
|
|
|
+ }
|
|
|
+#endif
|
|
|
+
|
|
|
+ p = tcp_output_alloc_header(pcb, optlen, 0, htonl(pcb->snd_nxt));
|
|
|
+ if (p == NULL) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: (ACK) could not allocate pbuf\n"));
|
|
|
+ return ERR_BUF;
|
|
|
+ }
|
|
|
+#if LWIP_TCP_TIMESTAMPS || CHECKSUM_GEN_TCP
|
|
|
+ tcphdr = (struct tcp_hdr *)p->payload;
|
|
|
+#endif /* LWIP_TCP_TIMESTAMPS || CHECKSUM_GEN_TCP */
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG,
|
|
|
+ ("tcp_output: sending ACK for %"U32_F"\n", pcb->rcv_nxt));
|
|
|
+ /* remove ACK flags from the PCB, as we send an empty ACK now */
|
|
|
+ pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
|
|
|
+
|
|
|
+ /* NB. MSS and window scale options are only sent on SYNs, so ignore them here */
|
|
|
+#if LWIP_TCP_TIMESTAMPS
|
|
|
+ pcb->ts_lastacksent = pcb->rcv_nxt;
|
|
|
+
|
|
|
+ if (pcb->flags & TF_TIMESTAMP) {
|
|
|
+ tcp_build_timestamp_option(pcb, (u32_t *)(tcphdr + 1));
|
|
|
+ }
|
|
|
+#endif
|
|
|
+
|
|
|
+#if CHECKSUM_GEN_TCP
|
|
|
+ tcphdr->chksum = ipX_chksum_pseudo(PCB_ISIPV6(pcb), p, IP_PROTO_TCP, p->tot_len,
|
|
|
+ &pcb->local_ip, &pcb->remote_ip);
|
|
|
+#endif
|
|
|
+#if LWIP_NETIF_HWADDRHINT
|
|
|
+ ipX_output_hinted(PCB_ISIPV6(pcb), p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, pcb->tos,
|
|
|
+ IP_PROTO_TCP, &pcb->addr_hint);
|
|
|
+#else /* LWIP_NETIF_HWADDRHINT*/
|
|
|
+ ipX_output(PCB_ISIPV6(pcb), p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, pcb->tos,
|
|
|
+ IP_PROTO_TCP);
|
|
|
+#endif /* LWIP_NETIF_HWADDRHINT*/
|
|
|
+ pbuf_free(p);
|
|
|
+
|
|
|
+ return ERR_OK;
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * Find out what we can send and send it
|
|
|
+ *
|
|
|
+ * @param pcb Protocol control block for the TCP connection to send data
|
|
|
+ * @return ERR_OK if data has been sent or nothing to send
|
|
|
+ * another err_t on error
|
|
|
+ */
|
|
|
+err_t
|
|
|
+tcp_output(struct tcp_pcb *pcb)
|
|
|
+{
|
|
|
+ struct tcp_seg *seg, *useg;
|
|
|
+ u32_t wnd, snd_nxt;
|
|
|
+#if TCP_CWND_DEBUG
|
|
|
+ s16_t i = 0;
|
|
|
+#endif /* TCP_CWND_DEBUG */
|
|
|
+
|
|
|
+ /* pcb->state LISTEN not allowed here */
|
|
|
+ LWIP_ASSERT("don't call tcp_output for listen-pcbs",
|
|
|
+ pcb->state != LISTEN);
|
|
|
+
|
|
|
+ /* First, check if we are invoked by the TCP input processing
|
|
|
+ code. If so, we do not output anything. Instead, we rely on the
|
|
|
+ input processing code to call us when input processing is done
|
|
|
+ with. */
|
|
|
+ if (tcp_input_pcb == pcb) {
|
|
|
+ return ERR_OK;
|
|
|
+ }
|
|
|
+
|
|
|
+ wnd = LWIP_MIN(pcb->snd_wnd, pcb->cwnd);
|
|
|
+
|
|
|
+ seg = pcb->unsent;
|
|
|
+
|
|
|
+ /* If the TF_ACK_NOW flag is set and no data will be sent (either
|
|
|
+ * because the ->unsent queue is empty or because the window does
|
|
|
+ * not allow it), construct an empty ACK segment and send it.
|
|
|
+ *
|
|
|
+ * If data is to be sent, we will just piggyback the ACK (see below).
|
|
|
+ */
|
|
|
+ if (pcb->flags & TF_ACK_NOW &&
|
|
|
+ (seg == NULL ||
|
|
|
+ ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len > wnd)) {
|
|
|
+ return tcp_send_empty_ack(pcb);
|
|
|
+ }
|
|
|
+
|
|
|
+ /* useg should point to last segment on unacked queue */
|
|
|
+ useg = pcb->unacked;
|
|
|
+ if (useg != NULL) {
|
|
|
+ for (; useg->next != NULL; useg = useg->next);
|
|
|
+ }
|
|
|
+
|
|
|
+#if TCP_OUTPUT_DEBUG
|
|
|
+ if (seg == NULL) {
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: nothing to send (%p)\n",
|
|
|
+ (void*)pcb->unsent));
|
|
|
+ }
|
|
|
+#endif /* TCP_OUTPUT_DEBUG */
|
|
|
+#if TCP_CWND_DEBUG
|
|
|
+ if (seg == NULL) {
|
|
|
+ LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_output: snd_wnd %"TCPWNDSIZE_F
|
|
|
+ ", cwnd %"TCPWNDSIZE_F", wnd %"U32_F
|
|
|
+ ", seg == NULL, ack %"U32_F"\n",
|
|
|
+ pcb->snd_wnd, pcb->cwnd, wnd, pcb->lastack));
|
|
|
+ } else {
|
|
|
+ LWIP_DEBUGF(TCP_CWND_DEBUG,
|
|
|
+ ("tcp_output: snd_wnd %"TCPWNDSIZE_F", cwnd %"TCPWNDSIZE_F", wnd %"U32_F
|
|
|
+ ", effwnd %"U32_F", seq %"U32_F", ack %"U32_F"\n",
|
|
|
+ pcb->snd_wnd, pcb->cwnd, wnd,
|
|
|
+ ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len,
|
|
|
+ ntohl(seg->tcphdr->seqno), pcb->lastack));
|
|
|
+ }
|
|
|
+#endif /* TCP_CWND_DEBUG */
|
|
|
+ /* data available and window allows it to be sent? */
|
|
|
+ while (seg != NULL &&
|
|
|
+ ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len <= wnd) {
|
|
|
+ LWIP_ASSERT("RST not expected here!",
|
|
|
+ (TCPH_FLAGS(seg->tcphdr) & TCP_RST) == 0);
|
|
|
+ /* Stop sending if the nagle algorithm would prevent it
|
|
|
+ * Don't stop:
|
|
|
+ * - if tcp_write had a memory error before (prevent delayed ACK timeout) or
|
|
|
+ * - if FIN was already enqueued for this PCB (SYN is always alone in a segment -
|
|
|
+ * either seg->next != NULL or pcb->unacked == NULL;
|
|
|
+ * RST is no sent using tcp_write/tcp_output.
|
|
|
+ */
|
|
|
+ if((tcp_do_output_nagle(pcb) == 0) &&
|
|
|
+ ((pcb->flags & (TF_NAGLEMEMERR | TF_FIN)) == 0)){
|
|
|
+ break;
|
|
|
+ }
|
|
|
+#if TCP_CWND_DEBUG
|
|
|
+ LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_output: snd_wnd %"TCPWNDSIZE_F", cwnd %"TCPWNDSIZE_F", wnd %"U32_F", effwnd %"U32_F", seq %"U32_F", ack %"U32_F", i %"S16_F"\n",
|
|
|
+ pcb->snd_wnd, pcb->cwnd, wnd,
|
|
|
+ ntohl(seg->tcphdr->seqno) + seg->len -
|
|
|
+ pcb->lastack,
|
|
|
+ ntohl(seg->tcphdr->seqno), pcb->lastack, i));
|
|
|
+ ++i;
|
|
|
+#endif /* TCP_CWND_DEBUG */
|
|
|
+
|
|
|
+ pcb->unsent = seg->next;
|
|
|
+
|
|
|
+ if (pcb->state != SYN_SENT) {
|
|
|
+ TCPH_SET_FLAG(seg->tcphdr, TCP_ACK);
|
|
|
+ pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
|
|
|
+ }
|
|
|
+
|
|
|
+#if TCP_OVERSIZE_DBGCHECK
|
|
|
+ seg->oversize_left = 0;
|
|
|
+#endif /* TCP_OVERSIZE_DBGCHECK */
|
|
|
+ tcp_output_segment(seg, pcb);
|
|
|
+ snd_nxt = ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg);
|
|
|
+ if (TCP_SEQ_LT(pcb->snd_nxt, snd_nxt)) {
|
|
|
+ pcb->snd_nxt = snd_nxt;
|
|
|
+ }
|
|
|
+ /* put segment on unacknowledged list if length > 0 */
|
|
|
+ if (TCP_TCPLEN(seg) > 0) {
|
|
|
+ seg->next = NULL;
|
|
|
+ /* unacked list is empty? */
|
|
|
+ if (pcb->unacked == NULL) {
|
|
|
+ pcb->unacked = seg;
|
|
|
+ useg = seg;
|
|
|
+ /* unacked list is not empty? */
|
|
|
+ } else {
|
|
|
+ /* In the case of fast retransmit, the packet should not go to the tail
|
|
|
+ * of the unacked queue, but rather somewhere before it. We need to check for
|
|
|
+ * this case. -STJ Jul 27, 2004 */
|
|
|
+ if (TCP_SEQ_LT(ntohl(seg->tcphdr->seqno), ntohl(useg->tcphdr->seqno))) {
|
|
|
+ /* add segment to before tail of unacked list, keeping the list sorted */
|
|
|
+ struct tcp_seg **cur_seg = &(pcb->unacked);
|
|
|
+ while (*cur_seg &&
|
|
|
+ TCP_SEQ_LT(ntohl((*cur_seg)->tcphdr->seqno), ntohl(seg->tcphdr->seqno))) {
|
|
|
+ cur_seg = &((*cur_seg)->next );
|
|
|
+ }
|
|
|
+ seg->next = (*cur_seg);
|
|
|
+ (*cur_seg) = seg;
|
|
|
+ } else {
|
|
|
+ /* add segment to tail of unacked list */
|
|
|
+ useg->next = seg;
|
|
|
+ useg = useg->next;
|
|
|
+ }
|
|
|
+ }
|
|
|
+ /* do not queue empty segments on the unacked list */
|
|
|
+ } else {
|
|
|
+ tcp_seg_free(seg);
|
|
|
+ }
|
|
|
+ seg = pcb->unsent;
|
|
|
+ }
|
|
|
+#if TCP_OVERSIZE
|
|
|
+ if (pcb->unsent == NULL) {
|
|
|
+ /* last unsent has been removed, reset unsent_oversize */
|
|
|
+ pcb->unsent_oversize = 0;
|
|
|
+ }
|
|
|
+#endif /* TCP_OVERSIZE */
|
|
|
+
|
|
|
+ pcb->flags &= ~TF_NAGLEMEMERR;
|
|
|
+ return ERR_OK;
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * Called by tcp_output() to actually send a TCP segment over IP.
|
|
|
+ *
|
|
|
+ * @param seg the tcp_seg to send
|
|
|
+ * @param pcb the tcp_pcb for the TCP connection used to send the segment
|
|
|
+ */
|
|
|
+static void
|
|
|
+tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb)
|
|
|
+{
|
|
|
+ u16_t len;
|
|
|
+ u32_t *opts;
|
|
|
+
|
|
|
+ /** @bug Exclude retransmitted segments from this count. */
|
|
|
+ snmp_inc_tcpoutsegs();
|
|
|
+
|
|
|
+ /* The TCP header has already been constructed, but the ackno and
|
|
|
+ wnd fields remain. */
|
|
|
+ seg->tcphdr->ackno = htonl(pcb->rcv_nxt);
|
|
|
+
|
|
|
+ /* advertise our receive window size in this TCP segment */
|
|
|
+#if LWIP_WND_SCALE
|
|
|
+ if (seg->flags & TF_SEG_OPTS_WND_SCALE) {
|
|
|
+ /* The Window field in a SYN segment itself (the only type where we send
|
|
|
+ the window scale option) is never scaled. */
|
|
|
+ seg->tcphdr->wnd = htons(pcb->rcv_ann_wnd);
|
|
|
+ } else
|
|
|
+#endif /* LWIP_WND_SCALE */
|
|
|
+ {
|
|
|
+ seg->tcphdr->wnd = htons(RCV_WND_SCALE(pcb, pcb->rcv_ann_wnd));
|
|
|
+ }
|
|
|
+
|
|
|
+ pcb->rcv_ann_right_edge = pcb->rcv_nxt + pcb->rcv_ann_wnd;
|
|
|
+
|
|
|
+ /* Add any requested options. NB MSS option is only set on SYN
|
|
|
+ packets, so ignore it here */
|
|
|
+ opts = (u32_t *)(void *)(seg->tcphdr + 1);
|
|
|
+ if (seg->flags & TF_SEG_OPTS_MSS) {
|
|
|
+ u16_t mss;
|
|
|
+#if TCP_CALCULATE_EFF_SEND_MSS
|
|
|
+ mss = tcp_eff_send_mss(TCP_MSS, &pcb->local_ip, &pcb->remote_ip, PCB_ISIPV6(pcb));
|
|
|
+#else /* TCP_CALCULATE_EFF_SEND_MSS */
|
|
|
+ mss = TCP_MSS;
|
|
|
+#endif /* TCP_CALCULATE_EFF_SEND_MSS */
|
|
|
+ *opts = TCP_BUILD_MSS_OPTION(mss);
|
|
|
+ opts += 1;
|
|
|
+ }
|
|
|
+#if LWIP_TCP_TIMESTAMPS
|
|
|
+ pcb->ts_lastacksent = pcb->rcv_nxt;
|
|
|
+
|
|
|
+ if (seg->flags & TF_SEG_OPTS_TS) {
|
|
|
+ tcp_build_timestamp_option(pcb, opts);
|
|
|
+ opts += 3;
|
|
|
+ }
|
|
|
+#endif
|
|
|
+#if LWIP_WND_SCALE
|
|
|
+ if (seg->flags & TF_SEG_OPTS_WND_SCALE) {
|
|
|
+ tcp_build_wnd_scale_option(opts);
|
|
|
+ opts += 1;
|
|
|
+ }
|
|
|
+#endif
|
|
|
+
|
|
|
+ /* Set retransmission timer running if it is not currently enabled
|
|
|
+ This must be set before checking the route. */
|
|
|
+ if (pcb->rtime == -1) {
|
|
|
+ pcb->rtime = 0;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* If we don't have a local IP address, we get one by
|
|
|
+ calling ip_route(). */
|
|
|
+ if (ipX_addr_isany(PCB_ISIPV6(pcb), &pcb->local_ip)) {
|
|
|
+ struct netif *netif;
|
|
|
+ ipX_addr_t *local_ip;
|
|
|
+ ipX_route_get_local_ipX(PCB_ISIPV6(pcb), &pcb->local_ip, &pcb->remote_ip, netif, local_ip);
|
|
|
+ if ((netif == NULL) || (local_ip == NULL)) {
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ ipX_addr_copy(PCB_ISIPV6(pcb), pcb->local_ip, *local_ip);
|
|
|
+ }
|
|
|
+
|
|
|
+ if (pcb->rttest == 0) {
|
|
|
+ pcb->rttest = tcp_ticks;
|
|
|
+ pcb->rtseq = ntohl(seg->tcphdr->seqno);
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_output_segment: rtseq %"U32_F"\n", pcb->rtseq));
|
|
|
+ }
|
|
|
+ LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output_segment: %"U32_F":%"U32_F"\n",
|
|
|
+ htonl(seg->tcphdr->seqno), htonl(seg->tcphdr->seqno) +
|
|
|
+ seg->len));
|
|
|
+
|
|
|
+ len = (u16_t)((u8_t *)seg->tcphdr - (u8_t *)seg->p->payload);
|
|
|
+
|
|
|
+ seg->p->len -= len;
|
|
|
+ seg->p->tot_len -= len;
|
|
|
+
|
|
|
+ seg->p->payload = seg->tcphdr;
|
|
|
+
|
|
|
+ seg->tcphdr->chksum = 0;
|
|
|
+#if TCP_CHECKSUM_ON_COPY
|
|
|
+ {
|
|
|
+ u32_t acc;
|
|
|
+#if TCP_CHECKSUM_ON_COPY_SANITY_CHECK
|
|
|
+ u16_t chksum_slow = ipX_chksum_pseudo(PCB_ISIPV6(pcb), seg->p, IP_PROTO_TCP,
|
|
|
+ seg->p->tot_len, &pcb->local_ip, &pcb->remote_ip);
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY_SANITY_CHECK */
|
|
|
+ if ((seg->flags & TF_SEG_DATA_CHECKSUMMED) == 0) {
|
|
|
+ LWIP_ASSERT("data included but not checksummed",
|
|
|
+ seg->p->tot_len == (TCPH_HDRLEN(seg->tcphdr) * 4));
|
|
|
+ }
|
|
|
+
|
|
|
+ /* rebuild TCP header checksum (TCP header changes for retransmissions!) */
|
|
|
+ acc = ipX_chksum_pseudo_partial(PCB_ISIPV6(pcb), seg->p, IP_PROTO_TCP,
|
|
|
+ seg->p->tot_len, TCPH_HDRLEN(seg->tcphdr) * 4, &pcb->local_ip, &pcb->remote_ip);
|
|
|
+ /* add payload checksum */
|
|
|
+ if (seg->chksum_swapped) {
|
|
|
+ seg->chksum = SWAP_BYTES_IN_WORD(seg->chksum);
|
|
|
+ seg->chksum_swapped = 0;
|
|
|
+ }
|
|
|
+ acc += (u16_t)~(seg->chksum);
|
|
|
+ seg->tcphdr->chksum = FOLD_U32T(acc);
|
|
|
+#if TCP_CHECKSUM_ON_COPY_SANITY_CHECK
|
|
|
+ if (chksum_slow != seg->tcphdr->chksum) {
|
|
|
+ LWIP_DEBUGF(TCP_DEBUG | LWIP_DBG_LEVEL_WARNING,
|
|
|
+ ("tcp_output_segment: calculated checksum is %"X16_F" instead of %"X16_F"\n",
|
|
|
+ seg->tcphdr->chksum, chksum_slow));
|
|
|
+ seg->tcphdr->chksum = chksum_slow;
|
|
|
+ }
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY_SANITY_CHECK */
|
|
|
+ }
|
|
|
+#else /* TCP_CHECKSUM_ON_COPY */
|
|
|
+#if CHECKSUM_GEN_TCP
|
|
|
+ seg->tcphdr->chksum = ipX_chksum_pseudo(PCB_ISIPV6(pcb), seg->p, IP_PROTO_TCP,
|
|
|
+ seg->p->tot_len, &pcb->local_ip, &pcb->remote_ip);
|
|
|
+#endif /* CHECKSUM_GEN_TCP */
|
|
|
+#endif /* TCP_CHECKSUM_ON_COPY */
|
|
|
+ TCP_STATS_INC(tcp.xmit);
|
|
|
+
|
|
|
+#if LWIP_NETIF_HWADDRHINT
|
|
|
+ ipX_output_hinted(PCB_ISIPV6(pcb), seg->p, &pcb->local_ip, &pcb->remote_ip,
|
|
|
+ pcb->ttl, pcb->tos, IP_PROTO_TCP, &pcb->addr_hint);
|
|
|
+#else /* LWIP_NETIF_HWADDRHINT*/
|
|
|
+ ipX_output(PCB_ISIPV6(pcb), seg->p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl,
|
|
|
+ pcb->tos, IP_PROTO_TCP);
|
|
|
+#endif /* LWIP_NETIF_HWADDRHINT*/
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * Send a TCP RESET packet (empty segment with RST flag set) either to
|
|
|
+ * abort a connection or to show that there is no matching local connection
|
|
|
+ * for a received segment.
|
|
|
+ *
|
|
|
+ * Called by tcp_abort() (to abort a local connection), tcp_input() (if no
|
|
|
+ * matching local pcb was found), tcp_listen_input() (if incoming segment
|
|
|
+ * has ACK flag set) and tcp_process() (received segment in the wrong state)
|
|
|
+ *
|
|
|
+ * Since a RST segment is in most cases not sent for an active connection,
|
|
|
+ * tcp_rst() has a number of arguments that are taken from a tcp_pcb for
|
|
|
+ * most other segment output functions.
|
|
|
+ *
|
|
|
+ * @param seqno the sequence number to use for the outgoing segment
|
|
|
+ * @param ackno the acknowledge number to use for the outgoing segment
|
|
|
+ * @param local_ip the local IP address to send the segment from
|
|
|
+ * @param remote_ip the remote IP address to send the segment to
|
|
|
+ * @param local_port the local TCP port to send the segment from
|
|
|
+ * @param remote_port the remote TCP port to send the segment to
|
|
|
+ */
|
|
|
+void
|
|
|
+tcp_rst_impl(u32_t seqno, u32_t ackno,
|
|
|
+ ipX_addr_t *local_ip, ipX_addr_t *remote_ip,
|
|
|
+ u16_t local_port, u16_t remote_port
|
|
|
+#if LWIP_IPV6
|
|
|
+ , u8_t isipv6
|
|
|
+#endif /* LWIP_IPV6 */
|
|
|
+ )
|
|
|
+{
|
|
|
+ struct pbuf *p;
|
|
|
+ struct tcp_hdr *tcphdr;
|
|
|
+ p = pbuf_alloc(PBUF_IP, TCP_HLEN, PBUF_RAM);
|
|
|
+ if (p == NULL) {
|
|
|
+ LWIP_DEBUGF(TCP_DEBUG, ("tcp_rst: could not allocate memory for pbuf\n"));
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr",
|
|
|
+ (p->len >= sizeof(struct tcp_hdr)));
|
|
|
+
|
|
|
+ tcphdr = (struct tcp_hdr *)p->payload;
|
|
|
+ tcphdr->src = htons(local_port);
|
|
|
+ tcphdr->dest = htons(remote_port);
|
|
|
+ tcphdr->seqno = htonl(seqno);
|
|
|
+ tcphdr->ackno = htonl(ackno);
|
|
|
+ TCPH_HDRLEN_FLAGS_SET(tcphdr, TCP_HLEN/4, TCP_RST | TCP_ACK);
|
|
|
+#if LWIP_WND_SCALE
|
|
|
+ tcphdr->wnd = PP_HTONS(((TCP_WND >> TCP_RCV_SCALE) & 0xFFFF));
|
|
|
+#else
|
|
|
+ tcphdr->wnd = PP_HTONS(TCP_WND);
|
|
|
+#endif
|
|
|
+ tcphdr->chksum = 0;
|
|
|
+ tcphdr->urgp = 0;
|
|
|
+
|
|
|
+ TCP_STATS_INC(tcp.xmit);
|
|
|
+ snmp_inc_tcpoutrsts();
|
|
|
+
|
|
|
+#if CHECKSUM_GEN_TCP
|
|
|
+ tcphdr->chksum = ipX_chksum_pseudo(isipv6, p, IP_PROTO_TCP, p->tot_len,
|
|
|
+ local_ip, remote_ip);
|
|
|
+#endif
|
|
|
+ /* Send output with hardcoded TTL/HL since we have no access to the pcb */
|
|
|
+ ipX_output(isipv6, p, local_ip, remote_ip, TCP_TTL, 0, IP_PROTO_TCP);
|
|
|
+ pbuf_free(p);
|
|
|
+ LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_rst: seqno %"U32_F" ackno %"U32_F".\n", seqno, ackno));
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * Requeue all unacked segments for retransmission
|
|
|
+ *
|
|
|
+ * Called by tcp_slowtmr() for slow retransmission.
|
|
|
+ *
|
|
|
+ * @param pcb the tcp_pcb for which to re-enqueue all unacked segments
|
|
|
+ */
|
|
|
+void
|
|
|
+tcp_rexmit_rto(struct tcp_pcb *pcb)
|
|
|
+{
|
|
|
+ struct tcp_seg *seg;
|
|
|
+
|
|
|
+ if (pcb->unacked == NULL) {
|
|
|
+ return;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* Move all unacked segments to the head of the unsent queue */
|
|
|
+ for (seg = pcb->unacked; seg->next != NULL; seg = seg->next);
|
|
|
+ /* concatenate unsent queue after unacked queue */
|
|
|
+ seg->next = pcb->unsent;
|
|
|
#if TCP_OVERSIZE && TCP_OVERSIZE_DBGCHECK
|
|
|
/* if last unsent changed, we need to update unsent_oversize */
|
|
|
if (pcb->unsent == NULL) {
|
|
|
pcb->unsent_oversize = seg->oversize_left;
|
|
|
}
|
|
|
-#endif /* TCP_OVERSIZE && TCP_OVERSIZE_DBGCHECK*/
|
|
|
- /* unsent queue is the concatenated queue (of unacked, unsent) */
|
|
|
- pcb->unsent = pcb->unacked;
|
|
|
- /* unacked queue is now empty */
|
|
|
- pcb->unacked = NULL;
|
|
|
-
|
|
|
- /* increment number of retransmissions */
|
|
|
- ++pcb->nrtx;
|
|
|
-
|
|
|
- /* Don't take any RTT measurements after retransmitting. */
|
|
|
- pcb->rttest = 0;
|
|
|
-
|
|
|
- /* Do the actual retransmission */
|
|
|
- tcp_output(pcb);
|
|
|
-}
|
|
|
-
|
|
|
-/**
|
|
|
- * Requeue the first unacked segment for retransmission
|
|
|
- *
|
|
|
- * Called by tcp_receive() for fast retramsmit.
|
|
|
- *
|
|
|
- * @param pcb the tcp_pcb for which to retransmit the first unacked segment
|
|
|
- */
|
|
|
-void
|
|
|
-tcp_rexmit(struct tcp_pcb *pcb)
|
|
|
-{
|
|
|
- struct tcp_seg *seg;
|
|
|
- struct tcp_seg **cur_seg;
|
|
|
-
|
|
|
- if (pcb->unacked == NULL) {
|
|
|
- return;
|
|
|
- }
|
|
|
-
|
|
|
- /* Move the first unacked segment to the unsent queue */
|
|
|
- /* Keep the unsent queue sorted. */
|
|
|
- seg = pcb->unacked;
|
|
|
- pcb->unacked = seg->next;
|
|
|
-
|
|
|
- cur_seg = &(pcb->unsent);
|
|
|
- while (*cur_seg &&
|
|
|
- TCP_SEQ_LT(ntohl((*cur_seg)->tcphdr->seqno), ntohl(seg->tcphdr->seqno))) {
|
|
|
- cur_seg = &((*cur_seg)->next );
|
|
|
- }
|
|
|
- seg->next = *cur_seg;
|
|
|
- *cur_seg = seg;
|
|
|
-#if TCP_OVERSIZE
|
|
|
- if (seg->next == NULL) {
|
|
|
- /* the retransmitted segment is last in unsent, so reset unsent_oversize */
|
|
|
- pcb->unsent_oversize = 0;
|
|
|
- }
|
|
|
-#endif /* TCP_OVERSIZE */
|
|
|
-
|
|
|
- ++pcb->nrtx;
|
|
|
-
|
|
|
- /* Don't take any rtt measurements after retransmitting. */
|
|
|
- pcb->rttest = 0;
|
|
|
-
|
|
|
- /* Do the actual retransmission. */
|
|
|
- snmp_inc_tcpretranssegs();
|
|
|
- /* No need to call tcp_output: we are always called from tcp_input()
|
|
|
- and thus tcp_output directly returns. */
|
|
|
-}
|
|
|
-
|
|
|
-
|
|
|
-/**
|
|
|
- * Handle retransmission after three dupacks received
|
|
|
- *
|
|
|
- * @param pcb the tcp_pcb for which to retransmit the first unacked segment
|
|
|
- */
|
|
|
-void
|
|
|
-tcp_rexmit_fast(struct tcp_pcb *pcb)
|
|
|
-{
|
|
|
- if (pcb->unacked != NULL && !(pcb->flags & TF_INFR)) {
|
|
|
- /* This is fast retransmit. Retransmit the first unacked segment. */
|
|
|
- LWIP_DEBUGF(TCP_FR_DEBUG,
|
|
|
- ("tcp_receive: dupacks %"U16_F" (%"U32_F
|
|
|
- "), fast retransmit %"U32_F"\n",
|
|
|
- (u16_t)pcb->dupacks, pcb->lastack,
|
|
|
- ntohl(pcb->unacked->tcphdr->seqno)));
|
|
|
- tcp_rexmit(pcb);
|
|
|
-
|
|
|
- /* Set ssthresh to half of the minimum of the current
|
|
|
- * cwnd and the advertised window */
|
|
|
- if (pcb->cwnd > pcb->snd_wnd) {
|
|
|
- pcb->ssthresh = pcb->snd_wnd / 2;
|
|
|
- } else {
|
|
|
- pcb->ssthresh = pcb->cwnd / 2;
|
|
|
- }
|
|
|
-
|
|
|
- /* The minimum value for ssthresh should be 2 MSS */
|
|
|
- if (pcb->ssthresh < 2*pcb->mss) {
|
|
|
- LWIP_DEBUGF(TCP_FR_DEBUG,
|
|
|
- ("tcp_receive: The minimum value for ssthresh %"U16_F
|
|
|
- " should be min 2 mss %"U16_F"...\n",
|
|
|
- pcb->ssthresh, 2*pcb->mss));
|
|
|
- pcb->ssthresh = 2*pcb->mss;
|
|
|
- }
|
|
|
-
|
|
|
- pcb->cwnd = pcb->ssthresh + 3 * pcb->mss;
|
|
|
- pcb->flags |= TF_INFR;
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-
|
|
|
-/**
|
|
|
- * Send keepalive packets to keep a connection active although
|
|
|
- * no data is sent over it.
|
|
|
- *
|
|
|
- * Called by tcp_slowtmr()
|
|
|
- *
|
|
|
- * @param pcb the tcp_pcb for which to send a keepalive packet
|
|
|
- */
|
|
|
-void
|
|
|
-tcp_keepalive(struct tcp_pcb *pcb)
|
|
|
-{
|
|
|
- struct pbuf *p;
|
|
|
-#if CHECKSUM_GEN_TCP
|
|
|
- struct tcp_hdr *tcphdr;
|
|
|
-#endif /* CHECKSUM_GEN_TCP */
|
|
|
-
|
|
|
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: sending KEEPALIVE probe to "));
|
|
|
- ipX_addr_debug_print(PCB_ISIPV6(pcb), TCP_DEBUG, &pcb->remote_ip);
|
|
|
- LWIP_DEBUGF(TCP_DEBUG, ("\n"));
|
|
|
-
|
|
|
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: tcp_ticks %"U32_F" pcb->tmr %"U32_F" pcb->keep_cnt_sent %"U16_F"\n",
|
|
|
- tcp_ticks, pcb->tmr, pcb->keep_cnt_sent));
|
|
|
-
|
|
|
- p = tcp_output_alloc_header(pcb, 0, 0, htonl(pcb->snd_nxt - 1));
|
|
|
- if(p == NULL) {
|
|
|
- LWIP_DEBUGF(TCP_DEBUG,
|
|
|
- ("tcp_keepalive: could not allocate memory for pbuf\n"));
|
|
|
- return;
|
|
|
- }
|
|
|
-#if CHECKSUM_GEN_TCP
|
|
|
- tcphdr = (struct tcp_hdr *)p->payload;
|
|
|
-
|
|
|
- tcphdr->chksum = ipX_chksum_pseudo(PCB_ISIPV6(pcb), p, IP_PROTO_TCP, p->tot_len,
|
|
|
- &pcb->local_ip, &pcb->remote_ip);
|
|
|
-#endif /* CHECKSUM_GEN_TCP */
|
|
|
- TCP_STATS_INC(tcp.xmit);
|
|
|
-
|
|
|
- /* Send output to IP */
|
|
|
-#if LWIP_NETIF_HWADDRHINT
|
|
|
- ipX_output_hinted(PCB_ISIPV6(pcb), p, &pcb->local_ip, &pcb->remote_ip,
|
|
|
- pcb->ttl, 0, IP_PROTO_TCP, &pcb->addr_hint);
|
|
|
-#else /* LWIP_NETIF_HWADDRHINT*/
|
|
|
- ipX_output(PCB_ISIPV6(pcb), p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl,
|
|
|
- 0, IP_PROTO_TCP);
|
|
|
-#endif /* LWIP_NETIF_HWADDRHINT*/
|
|
|
-
|
|
|
- pbuf_free(p);
|
|
|
-
|
|
|
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: seqno %"U32_F" ackno %"U32_F".\n",
|
|
|
- pcb->snd_nxt - 1, pcb->rcv_nxt));
|
|
|
-}
|
|
|
-
|
|
|
-
|
|
|
-/**
|
|
|
- * Send persist timer zero-window probes to keep a connection active
|
|
|
- * when a window update is lost.
|
|
|
- *
|
|
|
- * Called by tcp_slowtmr()
|
|
|
- *
|
|
|
- * @param pcb the tcp_pcb for which to send a zero-window probe packet
|
|
|
- */
|
|
|
-void
|
|
|
-tcp_zero_window_probe(struct tcp_pcb *pcb)
|
|
|
-{
|
|
|
- struct pbuf *p;
|
|
|
- struct tcp_hdr *tcphdr;
|
|
|
- struct tcp_seg *seg;
|
|
|
- u16_t len;
|
|
|
- u8_t is_fin;
|
|
|
-
|
|
|
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: sending ZERO WINDOW probe to "));
|
|
|
- ipX_addr_debug_print(PCB_ISIPV6(pcb), TCP_DEBUG, &pcb->remote_ip);
|
|
|
- LWIP_DEBUGF(TCP_DEBUG, ("\n"));
|
|
|
-
|
|
|
- LWIP_DEBUGF(TCP_DEBUG,
|
|
|
- ("tcp_zero_window_probe: tcp_ticks %"U32_F
|
|
|
- " pcb->tmr %"U32_F" pcb->keep_cnt_sent %"U16_F"\n",
|
|
|
- tcp_ticks, pcb->tmr, pcb->keep_cnt_sent));
|
|
|
-
|
|
|
- seg = pcb->unacked;
|
|
|
-
|
|
|
- if(seg == NULL) {
|
|
|
- seg = pcb->unsent;
|
|
|
- }
|
|
|
- if(seg == NULL) {
|
|
|
- return;
|
|
|
- }
|
|
|
-
|
|
|
- is_fin = ((TCPH_FLAGS(seg->tcphdr) & TCP_FIN) != 0) && (seg->len == 0);
|
|
|
- /* we want to send one seqno: either FIN or data (no options) */
|
|
|
- len = is_fin ? 0 : 1;
|
|
|
-
|
|
|
- p = tcp_output_alloc_header(pcb, 0, len, seg->tcphdr->seqno);
|
|
|
- if(p == NULL) {
|
|
|
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: no memory for pbuf\n"));
|
|
|
- return;
|
|
|
- }
|
|
|
- tcphdr = (struct tcp_hdr *)p->payload;
|
|
|
-
|
|
|
- if (is_fin) {
|
|
|
- /* FIN segment, no data */
|
|
|
- TCPH_FLAGS_SET(tcphdr, TCP_ACK | TCP_FIN);
|
|
|
- } else {
|
|
|
- /* Data segment, copy in one byte from the head of the unacked queue */
|
|
|
- char *d = ((char *)p->payload + TCP_HLEN);
|
|
|
- /* Depending on whether the segment has already been sent (unacked) or not
|
|
|
- (unsent), seg->p->payload points to the IP header or TCP header.
|
|
|
- Ensure we copy the first TCP data byte: */
|
|
|
- pbuf_copy_partial(seg->p, d, 1, seg->p->tot_len - seg->len);
|
|
|
- }
|
|
|
-
|
|
|
-#if CHECKSUM_GEN_TCP
|
|
|
- tcphdr->chksum = ipX_chksum_pseudo(PCB_ISIPV6(pcb), p, IP_PROTO_TCP, p->tot_len,
|
|
|
- &pcb->local_ip, &pcb->remote_ip);
|
|
|
-#endif
|
|
|
- TCP_STATS_INC(tcp.xmit);
|
|
|
-
|
|
|
- /* Send output to IP */
|
|
|
-#if LWIP_NETIF_HWADDRHINT
|
|
|
- ipX_output_hinted(PCB_ISIPV6(pcb), p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl,
|
|
|
- 0, IP_PROTO_TCP, &pcb->addr_hint);
|
|
|
-#else /* LWIP_NETIF_HWADDRHINT*/
|
|
|
- ipX_output(PCB_ISIPV6(pcb), p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, 0, IP_PROTO_TCP);
|
|
|
-#endif /* LWIP_NETIF_HWADDRHINT*/
|
|
|
-
|
|
|
- pbuf_free(p);
|
|
|
-
|
|
|
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: seqno %"U32_F
|
|
|
- " ackno %"U32_F".\n",
|
|
|
- pcb->snd_nxt - 1, pcb->rcv_nxt));
|
|
|
-}
|
|
|
-#endif /* LWIP_TCP */
|
|
|
+#endif /* TCP_OVERSIZE && TCP_OVERSIZE_DBGCHECK*/
|
|
|
+ /* unsent queue is the concatenated queue (of unacked, unsent) */
|
|
|
+ pcb->unsent = pcb->unacked;
|
|
|
+ /* unacked queue is now empty */
|
|
|
+ pcb->unacked = NULL;
|
|
|
+
|
|
|
+ /* increment number of retransmissions */
|
|
|
+ ++pcb->nrtx;
|
|
|
+
|
|
|
+ /* Don't take any RTT measurements after retransmitting. */
|
|
|
+ pcb->rttest = 0;
|
|
|
+
|
|
|
+ /* Do the actual retransmission */
|
|
|
+ tcp_output(pcb);
|
|
|
+}
|
|
|
+
|
|
|
+/**
|
|
|
+ * Requeue the first unacked segment for retransmission
|
|
|
+ *
|
|
|
+ * Called by tcp_receive() for fast retramsmit.
|
|
|
+ *
|
|
|
+ * @param pcb the tcp_pcb for which to retransmit the first unacked segment
|
|
|
+ */
|
|
|
+void
|
|
|
+tcp_rexmit(struct tcp_pcb *pcb)
|
|
|
+{
|
|
|
+ struct tcp_seg *seg;
|
|
|
+ struct tcp_seg **cur_seg;
|
|
|
+
|
|
|
+ if (pcb->unacked == NULL) {
|
|
|
+ return;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* Move the first unacked segment to the unsent queue */
|
|
|
+ /* Keep the unsent queue sorted. */
|
|
|
+ seg = pcb->unacked;
|
|
|
+ pcb->unacked = seg->next;
|
|
|
+
|
|
|
+ cur_seg = &(pcb->unsent);
|
|
|
+ while (*cur_seg &&
|
|
|
+ TCP_SEQ_LT(ntohl((*cur_seg)->tcphdr->seqno), ntohl(seg->tcphdr->seqno))) {
|
|
|
+ cur_seg = &((*cur_seg)->next );
|
|
|
+ }
|
|
|
+ seg->next = *cur_seg;
|
|
|
+ *cur_seg = seg;
|
|
|
+#if TCP_OVERSIZE
|
|
|
+ if (seg->next == NULL) {
|
|
|
+ /* the retransmitted segment is last in unsent, so reset unsent_oversize */
|
|
|
+ pcb->unsent_oversize = 0;
|
|
|
+ }
|
|
|
+#endif /* TCP_OVERSIZE */
|
|
|
+
|
|
|
+ ++pcb->nrtx;
|
|
|
+
|
|
|
+ /* Don't take any rtt measurements after retransmitting. */
|
|
|
+ pcb->rttest = 0;
|
|
|
+
|
|
|
+ /* Do the actual retransmission. */
|
|
|
+ snmp_inc_tcpretranssegs();
|
|
|
+ /* No need to call tcp_output: we are always called from tcp_input()
|
|
|
+ and thus tcp_output directly returns. */
|
|
|
+}
|
|
|
+
|
|
|
+
|
|
|
+/**
|
|
|
+ * Handle retransmission after three dupacks received
|
|
|
+ *
|
|
|
+ * @param pcb the tcp_pcb for which to retransmit the first unacked segment
|
|
|
+ */
|
|
|
+void
|
|
|
+tcp_rexmit_fast(struct tcp_pcb *pcb)
|
|
|
+{
|
|
|
+ if (pcb->unacked != NULL && !(pcb->flags & TF_INFR)) {
|
|
|
+ /* This is fast retransmit. Retransmit the first unacked segment. */
|
|
|
+ LWIP_DEBUGF(TCP_FR_DEBUG,
|
|
|
+ ("tcp_receive: dupacks %"U16_F" (%"U32_F
|
|
|
+ "), fast retransmit %"U32_F"\n",
|
|
|
+ (u16_t)pcb->dupacks, pcb->lastack,
|
|
|
+ ntohl(pcb->unacked->tcphdr->seqno)));
|
|
|
+ tcp_rexmit(pcb);
|
|
|
+
|
|
|
+ /* Set ssthresh to half of the minimum of the current
|
|
|
+ * cwnd and the advertised window */
|
|
|
+ if (pcb->cwnd > pcb->snd_wnd) {
|
|
|
+ pcb->ssthresh = pcb->snd_wnd / 2;
|
|
|
+ } else {
|
|
|
+ pcb->ssthresh = pcb->cwnd / 2;
|
|
|
+ }
|
|
|
+
|
|
|
+ /* The minimum value for ssthresh should be 2 MSS */
|
|
|
+ if (pcb->ssthresh < (2U * pcb->mss)) {
|
|
|
+ LWIP_DEBUGF(TCP_FR_DEBUG,
|
|
|
+ ("tcp_receive: The minimum value for ssthresh %"U16_F
|
|
|
+ " should be min 2 mss %"U16_F"...\n",
|
|
|
+ pcb->ssthresh, 2*pcb->mss));
|
|
|
+ pcb->ssthresh = 2*pcb->mss;
|
|
|
+ }
|
|
|
+
|
|
|
+ pcb->cwnd = pcb->ssthresh + 3 * pcb->mss;
|
|
|
+ pcb->flags |= TF_INFR;
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+
|
|
|
+/**
|
|
|
+ * Send keepalive packets to keep a connection active although
|
|
|
+ * no data is sent over it.
|
|
|
+ *
|
|
|
+ * Called by tcp_slowtmr()
|
|
|
+ *
|
|
|
+ * @param pcb the tcp_pcb for which to send a keepalive packet
|
|
|
+ */
|
|
|
+void
|
|
|
+tcp_keepalive(struct tcp_pcb *pcb)
|
|
|
+{
|
|
|
+ struct pbuf *p;
|
|
|
+#if CHECKSUM_GEN_TCP
|
|
|
+ struct tcp_hdr *tcphdr;
|
|
|
+#endif /* CHECKSUM_GEN_TCP */
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: sending KEEPALIVE probe to "));
|
|
|
+ ipX_addr_debug_print(PCB_ISIPV6(pcb), TCP_DEBUG, &pcb->remote_ip);
|
|
|
+ LWIP_DEBUGF(TCP_DEBUG, ("\n"));
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: tcp_ticks %"U32_F" pcb->tmr %"U32_F" pcb->keep_cnt_sent %"U16_F"\n",
|
|
|
+ tcp_ticks, pcb->tmr, pcb->keep_cnt_sent));
|
|
|
+
|
|
|
+ p = tcp_output_alloc_header(pcb, 0, 0, htonl(pcb->snd_nxt - 1));
|
|
|
+ if(p == NULL) {
|
|
|
+ LWIP_DEBUGF(TCP_DEBUG,
|
|
|
+ ("tcp_keepalive: could not allocate memory for pbuf\n"));
|
|
|
+ return;
|
|
|
+ }
|
|
|
+#if CHECKSUM_GEN_TCP
|
|
|
+ tcphdr = (struct tcp_hdr *)p->payload;
|
|
|
+
|
|
|
+ tcphdr->chksum = ipX_chksum_pseudo(PCB_ISIPV6(pcb), p, IP_PROTO_TCP, p->tot_len,
|
|
|
+ &pcb->local_ip, &pcb->remote_ip);
|
|
|
+#endif /* CHECKSUM_GEN_TCP */
|
|
|
+ TCP_STATS_INC(tcp.xmit);
|
|
|
+
|
|
|
+ /* Send output to IP */
|
|
|
+#if LWIP_NETIF_HWADDRHINT
|
|
|
+ ipX_output_hinted(PCB_ISIPV6(pcb), p, &pcb->local_ip, &pcb->remote_ip,
|
|
|
+ pcb->ttl, 0, IP_PROTO_TCP, &pcb->addr_hint);
|
|
|
+#else /* LWIP_NETIF_HWADDRHINT*/
|
|
|
+ ipX_output(PCB_ISIPV6(pcb), p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl,
|
|
|
+ 0, IP_PROTO_TCP);
|
|
|
+#endif /* LWIP_NETIF_HWADDRHINT*/
|
|
|
+
|
|
|
+ pbuf_free(p);
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: seqno %"U32_F" ackno %"U32_F".\n",
|
|
|
+ pcb->snd_nxt - 1, pcb->rcv_nxt));
|
|
|
+}
|
|
|
+
|
|
|
+
|
|
|
+/**
|
|
|
+ * Send persist timer zero-window probes to keep a connection active
|
|
|
+ * when a window update is lost.
|
|
|
+ *
|
|
|
+ * Called by tcp_slowtmr()
|
|
|
+ *
|
|
|
+ * @param pcb the tcp_pcb for which to send a zero-window probe packet
|
|
|
+ */
|
|
|
+void
|
|
|
+tcp_zero_window_probe(struct tcp_pcb *pcb)
|
|
|
+{
|
|
|
+ struct pbuf *p;
|
|
|
+ struct tcp_hdr *tcphdr;
|
|
|
+ struct tcp_seg *seg;
|
|
|
+ u16_t len;
|
|
|
+ u8_t is_fin;
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: sending ZERO WINDOW probe to "));
|
|
|
+ ipX_addr_debug_print(PCB_ISIPV6(pcb), TCP_DEBUG, &pcb->remote_ip);
|
|
|
+ LWIP_DEBUGF(TCP_DEBUG, ("\n"));
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_DEBUG,
|
|
|
+ ("tcp_zero_window_probe: tcp_ticks %"U32_F
|
|
|
+ " pcb->tmr %"U32_F" pcb->keep_cnt_sent %"U16_F"\n",
|
|
|
+ tcp_ticks, pcb->tmr, pcb->keep_cnt_sent));
|
|
|
+
|
|
|
+ seg = pcb->unacked;
|
|
|
+
|
|
|
+ if(seg == NULL) {
|
|
|
+ seg = pcb->unsent;
|
|
|
+ }
|
|
|
+ if(seg == NULL) {
|
|
|
+ return;
|
|
|
+ }
|
|
|
+
|
|
|
+ is_fin = ((TCPH_FLAGS(seg->tcphdr) & TCP_FIN) != 0) && (seg->len == 0);
|
|
|
+ /* we want to send one seqno: either FIN or data (no options) */
|
|
|
+ len = is_fin ? 0 : 1;
|
|
|
+
|
|
|
+ p = tcp_output_alloc_header(pcb, 0, len, seg->tcphdr->seqno);
|
|
|
+ if(p == NULL) {
|
|
|
+ LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: no memory for pbuf\n"));
|
|
|
+ return;
|
|
|
+ }
|
|
|
+ tcphdr = (struct tcp_hdr *)p->payload;
|
|
|
+
|
|
|
+ if (is_fin) {
|
|
|
+ /* FIN segment, no data */
|
|
|
+ TCPH_FLAGS_SET(tcphdr, TCP_ACK | TCP_FIN);
|
|
|
+ } else {
|
|
|
+ /* Data segment, copy in one byte from the head of the unacked queue */
|
|
|
+ char *d = ((char *)p->payload + TCP_HLEN);
|
|
|
+ /* Depending on whether the segment has already been sent (unacked) or not
|
|
|
+ (unsent), seg->p->payload points to the IP header or TCP header.
|
|
|
+ Ensure we copy the first TCP data byte: */
|
|
|
+ pbuf_copy_partial(seg->p, d, 1, seg->p->tot_len - seg->len);
|
|
|
+ }
|
|
|
+
|
|
|
+#if CHECKSUM_GEN_TCP
|
|
|
+ tcphdr->chksum = ipX_chksum_pseudo(PCB_ISIPV6(pcb), p, IP_PROTO_TCP, p->tot_len,
|
|
|
+ &pcb->local_ip, &pcb->remote_ip);
|
|
|
+#endif
|
|
|
+ TCP_STATS_INC(tcp.xmit);
|
|
|
+
|
|
|
+ /* Send output to IP */
|
|
|
+#if LWIP_NETIF_HWADDRHINT
|
|
|
+ ipX_output_hinted(PCB_ISIPV6(pcb), p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl,
|
|
|
+ 0, IP_PROTO_TCP, &pcb->addr_hint);
|
|
|
+#else /* LWIP_NETIF_HWADDRHINT*/
|
|
|
+ ipX_output(PCB_ISIPV6(pcb), p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, 0, IP_PROTO_TCP);
|
|
|
+#endif /* LWIP_NETIF_HWADDRHINT*/
|
|
|
+
|
|
|
+ pbuf_free(p);
|
|
|
+
|
|
|
+ LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: seqno %"U32_F
|
|
|
+ " ackno %"U32_F".\n",
|
|
|
+ pcb->snd_nxt - 1, pcb->rcv_nxt));
|
|
|
+}
|
|
|
+#endif /* LWIP_TCP */
|
Simon Goldschmidt