Yann Garcia / Mbed 2 deprecated DS130x_I2CApp

This short program illustrates how to use the DS130x_I2C library. My objective is to share the same RTC with Microchip 18F MCU.

Dependencies:   mbed DebugLibrary

NetServices/lwip/core/tcp_out.c@1:995212d326ca, 2011-02-11 (annotated)

Committer:
Yann
Date:
Fri Feb 11 10:17:20 2011 +0000
Revision:
1:995212d326ca
Parent:
0:f30e2135b0db 
V0.0.0.2

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Yann 0:f30e2135b0db 1 /**
Yann 0:f30e2135b0db 2 * @file
Yann 0:f30e2135b0db 3 * Transmission Control Protocol, outgoing traffic
Yann 0:f30e2135b0db 4 *
Yann 0:f30e2135b0db 5 * The output functions of TCP.
Yann 0:f30e2135b0db 6 *
Yann 0:f30e2135b0db 7 */
Yann 0:f30e2135b0db 8
Yann 0:f30e2135b0db 9 /*
Yann 0:f30e2135b0db 10 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
Yann 0:f30e2135b0db 11 * All rights reserved.
Yann 0:f30e2135b0db 12 *
Yann 0:f30e2135b0db 13 * Redistribution and use in source and binary forms, with or without modification,
Yann 0:f30e2135b0db 14 * are permitted provided that the following conditions are met:
Yann 0:f30e2135b0db 15 *
Yann 0:f30e2135b0db 16 * 1. Redistributions of source code must retain the above copyright notice,
Yann 0:f30e2135b0db 17 * this list of conditions and the following disclaimer.
Yann 0:f30e2135b0db 18 * 2. Redistributions in binary form must reproduce the above copyright notice,
Yann 0:f30e2135b0db 19 * this list of conditions and the following disclaimer in the documentation
Yann 0:f30e2135b0db 20 * and/or other materials provided with the distribution.
Yann 0:f30e2135b0db 21 * 3. The name of the author may not be used to endorse or promote products
Yann 0:f30e2135b0db 22 * derived from this software without specific prior written permission.
Yann 0:f30e2135b0db 23 *
Yann 0:f30e2135b0db 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
Yann 0:f30e2135b0db 25 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
Yann 0:f30e2135b0db 26 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
Yann 0:f30e2135b0db 27 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
Yann 0:f30e2135b0db 28 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
Yann 0:f30e2135b0db 29 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
Yann 0:f30e2135b0db 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
Yann 0:f30e2135b0db 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
Yann 0:f30e2135b0db 32 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
Yann 0:f30e2135b0db 33 * OF SUCH DAMAGE.
Yann 0:f30e2135b0db 34 *
Yann 0:f30e2135b0db 35 * This file is part of the lwIP TCP/IP stack.
Yann 0:f30e2135b0db 36 *
Yann 0:f30e2135b0db 37 * Author: Adam Dunkels <adam@sics.se>
Yann 0:f30e2135b0db 38 *
Yann 0:f30e2135b0db 39 */
Yann 0:f30e2135b0db 40
Yann 0:f30e2135b0db 41 #include "lwip/opt.h"
Yann 0:f30e2135b0db 42
Yann 0:f30e2135b0db 43 #if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
Yann 0:f30e2135b0db 44
Yann 0:f30e2135b0db 45 #include "lwip/tcp_impl.h"
Yann 0:f30e2135b0db 46 #include "lwip/def.h"
Yann 0:f30e2135b0db 47 #include "lwip/mem.h"
Yann 0:f30e2135b0db 48 #include "lwip/memp.h"
Yann 0:f30e2135b0db 49 #include "lwip/sys.h"
Yann 0:f30e2135b0db 50 #include "lwip/ip_addr.h"
Yann 0:f30e2135b0db 51 #include "lwip/netif.h"
Yann 0:f30e2135b0db 52 #include "lwip/inet_chksum.h"
Yann 0:f30e2135b0db 53 #include "lwip/stats.h"
Yann 0:f30e2135b0db 54 #include "lwip/snmp.h"
Yann 0:f30e2135b0db 55
Yann 0:f30e2135b0db 56 #include <string.h>
Yann 0:f30e2135b0db 57
Yann 0:f30e2135b0db 58 /* Define some copy-macros for checksum-on-copy so that the code looks
Yann 0:f30e2135b0db 59 nicer by preventing too many ifdef's. */
Yann 0:f30e2135b0db 60 #if TCP_CHECKSUM_ON_COPY
Yann 0:f30e2135b0db 61 #define TCP_DATA_COPY(dst, src, len, seg) do { \
Yann 0:f30e2135b0db 62 tcp_seg_add_chksum(LWIP_CHKSUM_COPY(dst, src, len), \
Yann 0:f30e2135b0db 63 len, &seg->chksum, &seg->chksum_swapped); \
Yann 0:f30e2135b0db 64 seg->flags |= TF_SEG_DATA_CHECKSUMMED; } while(0)
Yann 0:f30e2135b0db 65 #define TCP_DATA_COPY2(dst, src, len, chksum, chksum_swapped) \
Yann 0:f30e2135b0db 66 tcp_seg_add_chksum(LWIP_CHKSUM_COPY(dst, src, len), len, chksum, chksum_swapped);
Yann 0:f30e2135b0db 67 #else /* TCP_CHECKSUM_ON_COPY*/
Yann 0:f30e2135b0db 68 #define TCP_DATA_COPY(dst, src, len, seg) MEMCPY(dst, src, len)
Yann 0:f30e2135b0db 69 #define TCP_DATA_COPY2(dst, src, len, chksum, chksum_swapped) MEMCPY(dst, src, len)
Yann 0:f30e2135b0db 70 #endif /* TCP_CHECKSUM_ON_COPY*/
Yann 0:f30e2135b0db 71
Yann 0:f30e2135b0db 72 /** Define this to 1 for an extra check that the output checksum is valid
Yann 0:f30e2135b0db 73 * (usefule when the checksum is generated by the application, not the stack) */
Yann 0:f30e2135b0db 74 #ifndef TCP_CHECKSUM_ON_COPY_SANITY_CHECK
Yann 0:f30e2135b0db 75 #define TCP_CHECKSUM_ON_COPY_SANITY_CHECK 0
Yann 0:f30e2135b0db 76 #endif
Yann 0:f30e2135b0db 77
Yann 0:f30e2135b0db 78 /* Forward declarations.*/
Yann 0:f30e2135b0db 79 static void tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb);
Yann 0:f30e2135b0db 80
Yann 0:f30e2135b0db 81 /** Allocate a pbuf and create a tcphdr at p->payload, used for output
Yann 0:f30e2135b0db 82 * functions other than the default tcp_output -> tcp_output_segment
Yann 0:f30e2135b0db 83 * (e.g. tcp_send_empty_ack, etc.)
Yann 0:f30e2135b0db 84 *
Yann 0:f30e2135b0db 85 * @param pcb tcp pcb for which to send a packet (used to initialize tcp_hdr)
Yann 0:f30e2135b0db 86 * @param optlen length of header-options
Yann 0:f30e2135b0db 87 * @param datalen length of tcp data to reserve in pbuf
Yann 0:f30e2135b0db 88 * @param seqno_be seqno in network byte order (big-endian)
Yann 0:f30e2135b0db 89 * @return pbuf with p->payload being the tcp_hdr
Yann 0:f30e2135b0db 90 */
Yann 0:f30e2135b0db 91 static struct pbuf *
Yann 0:f30e2135b0db 92 tcp_output_alloc_header(struct tcp_pcb *pcb, u16_t optlen, u16_t datalen,
Yann 0:f30e2135b0db 93 u32_t seqno_be /* already in network byte order */)
Yann 0:f30e2135b0db 94 {
Yann 0:f30e2135b0db 95 struct tcp_hdr *tcphdr;
Yann 0:f30e2135b0db 96 struct pbuf *p = pbuf_alloc(PBUF_IP, TCP_HLEN + optlen + datalen, PBUF_RAM);
Yann 0:f30e2135b0db 97 if (p != NULL) {
Yann 0:f30e2135b0db 98 LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr",
Yann 0:f30e2135b0db 99 (p->len >= TCP_HLEN + optlen));
Yann 0:f30e2135b0db 100 tcphdr = (struct tcp_hdr *)p->payload;
Yann 0:f30e2135b0db 101 tcphdr->src = htons(pcb->local_port);
Yann 0:f30e2135b0db 102 tcphdr->dest = htons(pcb->remote_port);
Yann 0:f30e2135b0db 103 tcphdr->seqno = seqno_be;
Yann 0:f30e2135b0db 104 tcphdr->ackno = htonl(pcb->rcv_nxt);
Yann 0:f30e2135b0db 105 TCPH_HDRLEN_FLAGS_SET(tcphdr, (5 + optlen / 4), TCP_ACK);
Yann 0:f30e2135b0db 106 tcphdr->wnd = htons(pcb->rcv_ann_wnd);
Yann 0:f30e2135b0db 107 tcphdr->chksum = 0;
Yann 0:f30e2135b0db 108 tcphdr->urgp = 0;
Yann 0:f30e2135b0db 109
Yann 0:f30e2135b0db 110 /* If we're sending a packet, update the announced right window edge */
Yann 0:f30e2135b0db 111 pcb->rcv_ann_right_edge = pcb->rcv_nxt + pcb->rcv_ann_wnd;
Yann 0:f30e2135b0db 112 }
Yann 0:f30e2135b0db 113 return p;
Yann 0:f30e2135b0db 114 }
Yann 0:f30e2135b0db 115
Yann 0:f30e2135b0db 116 /**
Yann 0:f30e2135b0db 117 * Called by tcp_close() to send a segment including FIN flag but not data.
Yann 0:f30e2135b0db 118 *
Yann 0:f30e2135b0db 119 * @param pcb the tcp_pcb over which to send a segment
Yann 0:f30e2135b0db 120 * @return ERR_OK if sent, another err_t otherwise
Yann 0:f30e2135b0db 121 */
Yann 0:f30e2135b0db 122 err_t
Yann 0:f30e2135b0db 123 tcp_send_fin(struct tcp_pcb *pcb)
Yann 0:f30e2135b0db 124 {
Yann 0:f30e2135b0db 125 /* first, try to add the fin to the last unsent segment */
Yann 0:f30e2135b0db 126 if (pcb->unsent != NULL) {
Yann 0:f30e2135b0db 127 struct tcp_seg *last_unsent;
Yann 0:f30e2135b0db 128 for (last_unsent = pcb->unsent; last_unsent->next != NULL;
Yann 0:f30e2135b0db 129 last_unsent = last_unsent->next);
Yann 0:f30e2135b0db 130
Yann 0:f30e2135b0db 131 if ((TCPH_FLAGS(last_unsent->tcphdr) & (TCP_SYN | TCP_FIN | TCP_RST)) == 0) {
Yann 0:f30e2135b0db 132 /* no SYN/FIN/RST flag in the header, we can add the FIN flag */
Yann 0:f30e2135b0db 133 TCPH_SET_FLAG(last_unsent->tcphdr, TCP_FIN);
Yann 0:f30e2135b0db 134 return ERR_OK;
Yann 0:f30e2135b0db 135 }
Yann 0:f30e2135b0db 136 }
Yann 0:f30e2135b0db 137 /* no data, no length, flags, copy=1, no optdata */
Yann 0:f30e2135b0db 138 return tcp_enqueue_flags(pcb, TCP_FIN);
Yann 0:f30e2135b0db 139 }
Yann 0:f30e2135b0db 140
Yann 0:f30e2135b0db 141 /**
Yann 0:f30e2135b0db 142 * Create a TCP segment with prefilled header.
Yann 0:f30e2135b0db 143 *
Yann 0:f30e2135b0db 144 * Called by tcp_write and tcp_enqueue_flags.
Yann 0:f30e2135b0db 145 *
Yann 0:f30e2135b0db 146 * @param pcb Protocol control block for the TCP connection.
Yann 0:f30e2135b0db 147 * @param p pbuf that is used to hold the TCP header.
Yann 0:f30e2135b0db 148 * @param flags TCP flags for header.
Yann 0:f30e2135b0db 149 * @param seqno TCP sequence number of this packet
Yann 0:f30e2135b0db 150 * @param optflags options to include in TCP header
Yann 0:f30e2135b0db 151 * @return a new tcp_seg pointing to p, or NULL.
Yann 0:f30e2135b0db 152 * The TCP header is filled in except ackno and wnd.
Yann 0:f30e2135b0db 153 * p is freed on failure.
Yann 0:f30e2135b0db 154 */
Yann 0:f30e2135b0db 155 static struct tcp_seg *
Yann 0:f30e2135b0db 156 tcp_create_segment(struct tcp_pcb *pcb, struct pbuf *p, u8_t flags, u32_t seqno, u8_t optflags)
Yann 0:f30e2135b0db 157 {
Yann 0:f30e2135b0db 158 struct tcp_seg *seg;
Yann 0:f30e2135b0db 159 u8_t optlen = LWIP_TCP_OPT_LENGTH(optflags);
Yann 0:f30e2135b0db 160
Yann 0:f30e2135b0db 161 if ((seg = (struct tcp_seg *)memp_malloc(MEMP_TCP_SEG)) == NULL) {
Yann 0:f30e2135b0db 162 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_create_segment: no memory.\n"));
Yann 0:f30e2135b0db 163 pbuf_free(p);
Yann 0:f30e2135b0db 164 return NULL;
Yann 0:f30e2135b0db 165 }
Yann 0:f30e2135b0db 166 seg->flags = optflags;
Yann 0:f30e2135b0db 167 seg->next = NULL;
Yann 0:f30e2135b0db 168 seg->p = p;
Yann 0:f30e2135b0db 169 seg->dataptr = p->payload;
Yann 0:f30e2135b0db 170 seg->len = p->tot_len - optlen;
Yann 0:f30e2135b0db 171 #if TCP_OVERSIZE_DBGCHECK
Yann 0:f30e2135b0db 172 seg->oversize_left = 0;
Yann 0:f30e2135b0db 173 #endif /* TCP_OVERSIZE_DBGCHECK */
Yann 0:f30e2135b0db 174 #if TCP_CHECKSUM_ON_COPY
Yann 0:f30e2135b0db 175 seg->chksum = 0;
Yann 0:f30e2135b0db 176 seg->chksum_swapped = 0;
Yann 0:f30e2135b0db 177 /* check optflags */
Yann 0:f30e2135b0db 178 LWIP_ASSERT("invalid optflags passed: TF_SEG_DATA_CHECKSUMMED",
Yann 0:f30e2135b0db 179 (optflags & TF_SEG_DATA_CHECKSUMMED) == 0);
Yann 0:f30e2135b0db 180 #endif /* TCP_CHECKSUM_ON_COPY */
Yann 0:f30e2135b0db 181
Yann 0:f30e2135b0db 182 /* build TCP header */
Yann 0:f30e2135b0db 183 if (pbuf_header(p, TCP_HLEN)) {
Yann 0:f30e2135b0db 184 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_create_segment: no room for TCP header in pbuf.\n"));
Yann 0:f30e2135b0db 185 TCP_STATS_INC(tcp.err);
Yann 0:f30e2135b0db 186 tcp_seg_free(seg);
Yann 0:f30e2135b0db 187 return NULL;
Yann 0:f30e2135b0db 188 }
Yann 0:f30e2135b0db 189 seg->tcphdr = (struct tcp_hdr *)seg->p->payload;
Yann 0:f30e2135b0db 190 seg->tcphdr->src = htons(pcb->local_port);
Yann 0:f30e2135b0db 191 seg->tcphdr->dest = htons(pcb->remote_port);
Yann 0:f30e2135b0db 192 seg->tcphdr->seqno = htonl(seqno);
Yann 0:f30e2135b0db 193 /* ackno is set in tcp_output */
Yann 0:f30e2135b0db 194 TCPH_HDRLEN_FLAGS_SET(seg->tcphdr, (5 + optlen / 4), flags);
Yann 0:f30e2135b0db 195 /* wnd and chksum are set in tcp_output */
Yann 0:f30e2135b0db 196 seg->tcphdr->urgp = 0;
Yann 0:f30e2135b0db 197 return seg;
Yann 0:f30e2135b0db 198 }
Yann 0:f30e2135b0db 199
Yann 0:f30e2135b0db 200 /**
Yann 0:f30e2135b0db 201 * Allocate a PBUF_RAM pbuf, perhaps with extra space at the end.
Yann 0:f30e2135b0db 202 *
Yann 0:f30e2135b0db 203 * This function is like pbuf_alloc(layer, length, PBUF_RAM) except
Yann 0:f30e2135b0db 204 * there may be extra bytes available at the end.
Yann 0:f30e2135b0db 205 *
Yann 0:f30e2135b0db 206 * @param layer flag to define header size.
Yann 0:f30e2135b0db 207 * @param length size of the pbuf's payload.
Yann 0:f30e2135b0db 208 * @param max_length maximum usable size of payload+oversize.
Yann 0:f30e2135b0db 209 * @param oversize pointer to a u16_t that will receive the number of usable tail bytes.
Yann 0:f30e2135b0db 210 * @param pcb The TCP connection that willo enqueue the pbuf.
Yann 0:f30e2135b0db 211 * @param apiflags API flags given to tcp_write.
Yann 0:f30e2135b0db 212 * @param first_seg true when this pbuf will be used in the first enqueued segment.
Yann 0:f30e2135b0db 213 * @param
Yann 0:f30e2135b0db 214 */
Yann 0:f30e2135b0db 215 #if TCP_OVERSIZE
Yann 0:f30e2135b0db 216 static struct pbuf *
Yann 0:f30e2135b0db 217 tcp_pbuf_prealloc(pbuf_layer layer, u16_t length, u16_t max_length,
Yann 0:f30e2135b0db 218 u16_t *oversize, struct tcp_pcb *pcb, u8_t apiflags,
Yann 0:f30e2135b0db 219 u8_t first_seg)
Yann 0:f30e2135b0db 220 {
Yann 0:f30e2135b0db 221 struct pbuf *p;
Yann 0:f30e2135b0db 222 u16_t alloc = length;
Yann 0:f30e2135b0db 223
Yann 0:f30e2135b0db 224 #if LWIP_NETIF_TX_SINGLE_PBUF
Yann 0:f30e2135b0db 225 LWIP_UNUSED_ARG(max_length);
Yann 0:f30e2135b0db 226 LWIP_UNUSED_ARG(pcb);
Yann 0:f30e2135b0db 227 LWIP_UNUSED_ARG(apiflags);
Yann 0:f30e2135b0db 228 LWIP_UNUSED_ARG(first_seg);
Yann 0:f30e2135b0db 229 /* always create MSS-sized pbufs */
Yann 0:f30e2135b0db 230 alloc = TCP_MSS;
Yann 0:f30e2135b0db 231 #else /* LWIP_NETIF_TX_SINGLE_PBUF */
Yann 0:f30e2135b0db 232 if (length < max_length) {
Yann 0:f30e2135b0db 233 /* Should we allocate an oversized pbuf, or just the minimum
Yann 0:f30e2135b0db 234 * length required? If tcp_write is going to be called again
Yann 0:f30e2135b0db 235 * before this segment is transmitted, we want the oversized
Yann 0:f30e2135b0db 236 * buffer. If the segment will be transmitted immediately, we can
Yann 0:f30e2135b0db 237 * save memory by allocating only length. We use a simple
Yann 0:f30e2135b0db 238 * heuristic based on the following information:
Yann 0:f30e2135b0db 239 *
Yann 0:f30e2135b0db 240 * Did the user set TCP_WRITE_FLAG_MORE?
Yann 0:f30e2135b0db 241 *
Yann 0:f30e2135b0db 242 * Will the Nagle algorithm defer transmission of this segment?
Yann 0:f30e2135b0db 243 */
Yann 0:f30e2135b0db 244 if ((apiflags & TCP_WRITE_FLAG_MORE) ||
Yann 0:f30e2135b0db 245 (!(pcb->flags & TF_NODELAY) &&
Yann 0:f30e2135b0db 246 (!first_seg ||
Yann 0:f30e2135b0db 247 pcb->unsent != NULL ||
Yann 0:f30e2135b0db 248 pcb->unacked != NULL))) {
Yann 0:f30e2135b0db 249 alloc = LWIP_MIN(max_length, LWIP_MEM_ALIGN_SIZE(length + TCP_OVERSIZE));
Yann 0:f30e2135b0db 250 }
Yann 0:f30e2135b0db 251 }
Yann 0:f30e2135b0db 252 #endif /* LWIP_NETIF_TX_SINGLE_PBUF */
Yann 0:f30e2135b0db 253 p = pbuf_alloc(layer, alloc, PBUF_RAM);
Yann 0:f30e2135b0db 254 if (p == NULL) {
Yann 0:f30e2135b0db 255 return NULL;
Yann 0:f30e2135b0db 256 }
Yann 0:f30e2135b0db 257 LWIP_ASSERT("need unchained pbuf", p->next == NULL);
Yann 0:f30e2135b0db 258 *oversize = p->len - length;
Yann 0:f30e2135b0db 259 /* trim p->len to the currently used size */
Yann 0:f30e2135b0db 260 p->len = p->tot_len = length;
Yann 0:f30e2135b0db 261 return p;
Yann 0:f30e2135b0db 262 }
Yann 0:f30e2135b0db 263 #else /* TCP_OVERSIZE */
Yann 0:f30e2135b0db 264 #define tcp_pbuf_prealloc(layer, length, mx, os, pcb, api, fst) pbuf_alloc((layer), (length), PBUF_RAM)
Yann 0:f30e2135b0db 265 #endif /* TCP_OVERSIZE */
Yann 0:f30e2135b0db 266
Yann 0:f30e2135b0db 267 #if TCP_CHECKSUM_ON_COPY
Yann 0:f30e2135b0db 268 /** Add a checksum of newly added data to the segment */
Yann 0:f30e2135b0db 269 static void
Yann 0:f30e2135b0db 270 tcp_seg_add_chksum(u16_t chksum, u16_t len, u16_t *seg_chksum,
Yann 0:f30e2135b0db 271 u8_t *seg_chksum_swapped)
Yann 0:f30e2135b0db 272 {
Yann 0:f30e2135b0db 273 u32_t helper;
Yann 0:f30e2135b0db 274 /* add chksum to old chksum and fold to u16_t */
Yann 0:f30e2135b0db 275 helper = chksum + *seg_chksum;
Yann 0:f30e2135b0db 276 chksum = FOLD_U32T(helper);
Yann 0:f30e2135b0db 277 if ((len & 1) != 0) {
Yann 0:f30e2135b0db 278 *seg_chksum_swapped = 1 - *seg_chksum_swapped;
Yann 0:f30e2135b0db 279 chksum = SWAP_BYTES_IN_WORD(chksum);
Yann 0:f30e2135b0db 280 }
Yann 0:f30e2135b0db 281 *seg_chksum = chksum;
Yann 0:f30e2135b0db 282 }
Yann 0:f30e2135b0db 283 #endif /* TCP_CHECKSUM_ON_COPY */
Yann 0:f30e2135b0db 284
Yann 0:f30e2135b0db 285 /** Checks if tcp_write is allowed or not (checks state, snd_buf and snd_queuelen).
Yann 0:f30e2135b0db 286 *
Yann 0:f30e2135b0db 287 * @param pcb the tcp pcb to check for
Yann 0:f30e2135b0db 288 * @param len length of data to send (checked agains snd_buf)
Yann 0:f30e2135b0db 289 * @return ERR_OK if tcp_write is allowed to proceed, another err_t otherwise
Yann 0:f30e2135b0db 290 */
Yann 0:f30e2135b0db 291 static err_t
Yann 0:f30e2135b0db 292 tcp_write_checks(struct tcp_pcb *pcb, u16_t len)
Yann 0:f30e2135b0db 293 {
Yann 0:f30e2135b0db 294 /* connection is in invalid state for data transmission? */
Yann 0:f30e2135b0db 295 if ((pcb->state != ESTABLISHED) &&
Yann 0:f30e2135b0db 296 (pcb->state != CLOSE_WAIT) &&
Yann 0:f30e2135b0db 297 (pcb->state != SYN_SENT) &&
Yann 0:f30e2135b0db 298 (pcb->state != SYN_RCVD)) {
Yann 0:f30e2135b0db 299 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_STATE | LWIP_DBG_LEVEL_SEVERE, ("tcp_write() called in invalid state\n"));
Yann 0:f30e2135b0db 300 return ERR_CONN;
Yann 0:f30e2135b0db 301 } else if (len == 0) {
Yann 0:f30e2135b0db 302 return ERR_OK;
Yann 0:f30e2135b0db 303 }
Yann 0:f30e2135b0db 304
Yann 0:f30e2135b0db 305 /* fail on too much data */
Yann 0:f30e2135b0db 306 if (len > pcb->snd_buf) {
Yann 0:f30e2135b0db 307 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too much data (len=%"U16_F" > snd_buf=%"U16_F")\n",
Yann 0:f30e2135b0db 308 len, pcb->snd_buf));
Yann 0:f30e2135b0db 309 pcb->flags |= TF_NAGLEMEMERR;
Yann 0:f30e2135b0db 310 return ERR_MEM;
Yann 0:f30e2135b0db 311 }
Yann 0:f30e2135b0db 312
Yann 0:f30e2135b0db 313 LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen));
Yann 0:f30e2135b0db 314
Yann 0:f30e2135b0db 315 /* If total number of pbufs on the unsent/unacked queues exceeds the
Yann 0:f30e2135b0db 316 * configured maximum, return an error */
Yann 0:f30e2135b0db 317 /* check for configured max queuelen and possible overflow */
Yann 0:f30e2135b0db 318 if ((pcb->snd_queuelen >= TCP_SND_QUEUELEN) || (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
Yann 0:f30e2135b0db 319 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_write: too long queue %"U16_F" (max %"U16_F")\n",
Yann 0:f30e2135b0db 320 pcb->snd_queuelen, TCP_SND_QUEUELEN));
Yann 0:f30e2135b0db 321 TCP_STATS_INC(tcp.memerr);
Yann 0:f30e2135b0db 322 pcb->flags |= TF_NAGLEMEMERR;
Yann 0:f30e2135b0db 323 return ERR_MEM;
Yann 0:f30e2135b0db 324 }
Yann 0:f30e2135b0db 325 if (pcb->snd_queuelen != 0) {
Yann 0:f30e2135b0db 326 LWIP_ASSERT("tcp_write: pbufs on queue => at least one queue non-empty",
Yann 0:f30e2135b0db 327 pcb->unacked != NULL || pcb->unsent != NULL);
Yann 0:f30e2135b0db 328 } else {
Yann 0:f30e2135b0db 329 LWIP_ASSERT("tcp_write: no pbufs on queue => both queues empty",
Yann 0:f30e2135b0db 330 pcb->unacked == NULL && pcb->unsent == NULL);
Yann 0:f30e2135b0db 331 }
Yann 0:f30e2135b0db 332 return ERR_OK;
Yann 0:f30e2135b0db 333 }
Yann 0:f30e2135b0db 334
Yann 0:f30e2135b0db 335 /**
Yann 0:f30e2135b0db 336 * Write data for sending (but does not send it immediately).
Yann 0:f30e2135b0db 337 *
Yann 0:f30e2135b0db 338 * It waits in the expectation of more data being sent soon (as
Yann 0:f30e2135b0db 339 * it can send them more efficiently by combining them together).
Yann 0:f30e2135b0db 340 * To prompt the system to send data now, call tcp_output() after
Yann 0:f30e2135b0db 341 * calling tcp_write().
Yann 0:f30e2135b0db 342 *
Yann 0:f30e2135b0db 343 * @param pcb Protocol control block for the TCP connection to enqueue data for.
Yann 0:f30e2135b0db 344 * @param arg Pointer to the data to be enqueued for sending.
Yann 0:f30e2135b0db 345 * @param len Data length in bytes
Yann 0:f30e2135b0db 346 * @param apiflags combination of following flags :
Yann 0:f30e2135b0db 347 * - TCP_WRITE_FLAG_COPY (0x01) data will be copied into memory belonging to the stack
Yann 0:f30e2135b0db 348 * - TCP_WRITE_FLAG_MORE (0x02) for TCP connection, PSH flag will be set on last segment sent,
Yann 0:f30e2135b0db 349 * @return ERR_OK if enqueued, another err_t on error
Yann 0:f30e2135b0db 350 */
Yann 0:f30e2135b0db 351 err_t
Yann 0:f30e2135b0db 352 tcp_write(struct tcp_pcb *pcb, const void *arg, u16_t len, u8_t apiflags)
Yann 0:f30e2135b0db 353 {
Yann 0:f30e2135b0db 354 struct pbuf *concat_p = NULL;
Yann 0:f30e2135b0db 355 struct tcp_seg *last_unsent = NULL, *seg = NULL, *prev_seg = NULL, *queue = NULL;
Yann 0:f30e2135b0db 356 u16_t pos = 0; /* position in 'arg' data */
Yann 0:f30e2135b0db 357 u16_t queuelen;
Yann 0:f30e2135b0db 358 u8_t optlen = 0;
Yann 0:f30e2135b0db 359 u8_t optflags = 0;
Yann 0:f30e2135b0db 360 #if TCP_OVERSIZE
Yann 0:f30e2135b0db 361 u16_t oversize = 0;
Yann 0:f30e2135b0db 362 u16_t oversize_used = 0;
Yann 0:f30e2135b0db 363 #endif /* TCP_OVERSIZE */
Yann 0:f30e2135b0db 364 #if TCP_CHECKSUM_ON_COPY
Yann 0:f30e2135b0db 365 u16_t concat_chksum = 0;
Yann 0:f30e2135b0db 366 u8_t concat_chksum_swapped = 0;
Yann 0:f30e2135b0db 367 u16_t concat_chksummed = 0;
Yann 0:f30e2135b0db 368 #endif /* TCP_CHECKSUM_ON_COPY */
Yann 0:f30e2135b0db 369 err_t err;
Yann 0:f30e2135b0db 370
Yann 0:f30e2135b0db 371 #if LWIP_NETIF_TX_SINGLE_PBUF
Yann 0:f30e2135b0db 372 /* Always copy to try to create single pbufs for TX */
Yann 0:f30e2135b0db 373 apiflags |= TCP_WRITE_FLAG_COPY;
Yann 0:f30e2135b0db 374 #endif /* LWIP_NETIF_TX_SINGLE_PBUF */
Yann 0:f30e2135b0db 375
Yann 0:f30e2135b0db 376 LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_write(pcb=%p, data=%p, len=%"U16_F", apiflags=%"U16_F")\n",
Yann 0:f30e2135b0db 377 (void *)pcb, arg, len, (u16_t)apiflags));
Yann 0:f30e2135b0db 378 LWIP_ERROR("tcp_write: arg == NULL (programmer violates API)",
Yann 0:f30e2135b0db 379 arg != NULL, return ERR_ARG;);
Yann 0:f30e2135b0db 380
Yann 0:f30e2135b0db 381 err = tcp_write_checks(pcb, len);
Yann 0:f30e2135b0db 382 if (err != ERR_OK) {
Yann 0:f30e2135b0db 383 return err;
Yann 0:f30e2135b0db 384 }
Yann 0:f30e2135b0db 385 queuelen = pcb->snd_queuelen;
Yann 0:f30e2135b0db 386
Yann 0:f30e2135b0db 387 #if LWIP_TCP_TIMESTAMPS
Yann 0:f30e2135b0db 388 if ((pcb->flags & TF_TIMESTAMP)) {
Yann 0:f30e2135b0db 389 optflags = TF_SEG_OPTS_TS;
Yann 0:f30e2135b0db 390 optlen = LWIP_TCP_OPT_LENGTH(TF_SEG_OPTS_TS);
Yann 0:f30e2135b0db 391 }
Yann 0:f30e2135b0db 392 #endif /* LWIP_TCP_TIMESTAMPS */
Yann 0:f30e2135b0db 393
Yann 0:f30e2135b0db 394
Yann 0:f30e2135b0db 395 /*
Yann 0:f30e2135b0db 396 * TCP segmentation is done in three phases with increasing complexity:
Yann 0:f30e2135b0db 397 *
Yann 0:f30e2135b0db 398 * 1. Copy data directly into an oversized pbuf.
Yann 0:f30e2135b0db 399 * 2. Chain a new pbuf to the end of pcb->unsent.
Yann 0:f30e2135b0db 400 * 3. Create new segments.
Yann 0:f30e2135b0db 401 *
Yann 0:f30e2135b0db 402 * We may run out of memory at any point. In that case we must
Yann 0:f30e2135b0db 403 * return ERR_MEM and not change anything in pcb. Therefore, all
Yann 0:f30e2135b0db 404 * changes are recorded in local variables and committed at the end
Yann 0:f30e2135b0db 405 * of the function. Some pcb fields are maintained in local copies:
Yann 0:f30e2135b0db 406 *
Yann 0:f30e2135b0db 407 * queuelen = pcb->snd_queuelen
Yann 0:f30e2135b0db 408 * oversize = pcb->unsent_oversize
Yann 0:f30e2135b0db 409 *
Yann 0:f30e2135b0db 410 * These variables are set consistently by the phases:
Yann 0:f30e2135b0db 411 *
Yann 0:f30e2135b0db 412 * seg points to the last segment tampered with.
Yann 0:f30e2135b0db 413 *
Yann 0:f30e2135b0db 414 * pos records progress as data is segmented.
Yann 0:f30e2135b0db 415 */
Yann 0:f30e2135b0db 416
Yann 0:f30e2135b0db 417 /* Find the tail of the unsent queue. */
Yann 0:f30e2135b0db 418 if (pcb->unsent != NULL) {
Yann 0:f30e2135b0db 419 u16_t space;
Yann 0:f30e2135b0db 420 u16_t unsent_optlen;
Yann 0:f30e2135b0db 421
Yann 0:f30e2135b0db 422 /* @todo: this could be sped up by keeping last_unsent in the pcb */
Yann 0:f30e2135b0db 423 for (last_unsent = pcb->unsent; last_unsent->next != NULL;
Yann 0:f30e2135b0db 424 last_unsent = last_unsent->next);
Yann 0:f30e2135b0db 425
Yann 0:f30e2135b0db 426 /* Usable space at the end of the last unsent segment */
Yann 0:f30e2135b0db 427 unsent_optlen = LWIP_TCP_OPT_LENGTH(last_unsent->flags);
Yann 0:f30e2135b0db 428 space = pcb->mss - (last_unsent->len + unsent_optlen);
Yann 0:f30e2135b0db 429
Yann 0:f30e2135b0db 430 /*
Yann 0:f30e2135b0db 431 * Phase 1: Copy data directly into an oversized pbuf.
Yann 0:f30e2135b0db 432 *
Yann 0:f30e2135b0db 433 * The number of bytes copied is recorded in the oversize_used
Yann 0:f30e2135b0db 434 * variable. The actual copying is done at the bottom of the
Yann 0:f30e2135b0db 435 * function.
Yann 0:f30e2135b0db 436 */
Yann 0:f30e2135b0db 437 #if TCP_OVERSIZE
Yann 0:f30e2135b0db 438 #if TCP_OVERSIZE_DBGCHECK
Yann 0:f30e2135b0db 439 /* check that pcb->unsent_oversize matches last_unsent->unsent_oversize */
Yann 0:f30e2135b0db 440 LWIP_ASSERT("unsent_oversize mismatch (pcb vs. last_unsent)",
Yann 0:f30e2135b0db 441 pcb->unsent_oversize == last_unsent->oversize_left);
Yann 0:f30e2135b0db 442 #endif /* TCP_OVERSIZE_DBGCHECK */
Yann 0:f30e2135b0db 443 oversize = pcb->unsent_oversize;
Yann 0:f30e2135b0db 444 if (oversize > 0) {
Yann 0:f30e2135b0db 445 LWIP_ASSERT("inconsistent oversize vs. space", oversize_used <= space);
Yann 0:f30e2135b0db 446 seg = last_unsent;
Yann 0:f30e2135b0db 447 oversize_used = oversize < len ? oversize : len;
Yann 0:f30e2135b0db 448 pos += oversize_used;
Yann 0:f30e2135b0db 449 oversize -= oversize_used;
Yann 0:f30e2135b0db 450 space -= oversize_used;
Yann 0:f30e2135b0db 451 }
Yann 0:f30e2135b0db 452 /* now we are either finished or oversize is zero */
Yann 0:f30e2135b0db 453 LWIP_ASSERT("inconsistend oversize vs. len", (oversize == 0) || (pos == len));
Yann 0:f30e2135b0db 454 #endif /* TCP_OVERSIZE */
Yann 0:f30e2135b0db 455
Yann 0:f30e2135b0db 456 /*
Yann 0:f30e2135b0db 457 * Phase 2: Chain a new pbuf to the end of pcb->unsent.
Yann 0:f30e2135b0db 458 *
Yann 0:f30e2135b0db 459 * We don't extend segments containing SYN/FIN flags or options
Yann 0:f30e2135b0db 460 * (len==0). The new pbuf is kept in concat_p and pbuf_cat'ed at
Yann 0:f30e2135b0db 461 * the end.
Yann 0:f30e2135b0db 462 */
Yann 0:f30e2135b0db 463 if ((pos < len) && (space > 0) && (last_unsent->len > 0)) {
Yann 0:f30e2135b0db 464 u16_t seglen = space < len - pos ? space : len - pos;
Yann 0:f30e2135b0db 465 seg = last_unsent;
Yann 0:f30e2135b0db 466
Yann 0:f30e2135b0db 467 /* Create a pbuf with a copy or reference to seglen bytes. We
Yann 0:f30e2135b0db 468 * can use PBUF_RAW here since the data appears in the middle of
Yann 0:f30e2135b0db 469 * a segment. A header will never be prepended. */
Yann 0:f30e2135b0db 470 if (apiflags & TCP_WRITE_FLAG_COPY) {
Yann 0:f30e2135b0db 471 /* Data is copied */
Yann 0:f30e2135b0db 472 if ((concat_p = tcp_pbuf_prealloc(PBUF_RAW, seglen, space, &oversize, pcb, apiflags, 1)) == NULL) {
Yann 0:f30e2135b0db 473 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2,
Yann 0:f30e2135b0db 474 ("tcp_write : could not allocate memory for pbuf copy size %"U16_F"\n",
Yann 0:f30e2135b0db 475 seglen));
Yann 0:f30e2135b0db 476 goto memerr;
Yann 0:f30e2135b0db 477 }
Yann 0:f30e2135b0db 478 #if TCP_OVERSIZE_DBGCHECK
Yann 0:f30e2135b0db 479 last_unsent->oversize_left = oversize;
Yann 0:f30e2135b0db 480 #endif /* TCP_OVERSIZE_DBGCHECK */
Yann 0:f30e2135b0db 481 TCP_DATA_COPY2(concat_p->payload, (u8_t*)arg + pos, seglen, &concat_chksum, &concat_chksum_swapped);
Yann 0:f30e2135b0db 482 #if TCP_CHECKSUM_ON_COPY
Yann 0:f30e2135b0db 483 concat_chksummed += seglen;
Yann 0:f30e2135b0db 484 #endif /* TCP_CHECKSUM_ON_COPY */
Yann 0:f30e2135b0db 485 } else {
Yann 0:f30e2135b0db 486 /* Data is not copied */
Yann 0:f30e2135b0db 487 if ((concat_p = pbuf_alloc(PBUF_RAW, seglen, PBUF_ROM)) == NULL) {
Yann 0:f30e2135b0db 488 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2,
Yann 0:f30e2135b0db 489 ("tcp_write: could not allocate memory for zero-copy pbuf\n"));
Yann 0:f30e2135b0db 490 goto memerr;
Yann 0:f30e2135b0db 491 }
Yann 0:f30e2135b0db 492 #if TCP_CHECKSUM_ON_COPY
Yann 0:f30e2135b0db 493 /* calculate the checksum of nocopy-data */
Yann 0:f30e2135b0db 494 tcp_seg_add_chksum(~inet_chksum((u8_t*)arg + pos, seglen), seglen,
Yann 0:f30e2135b0db 495 &concat_chksum, &concat_chksum_swapped);
Yann 0:f30e2135b0db 496 concat_chksummed += seglen;
Yann 0:f30e2135b0db 497 #endif /* TCP_CHECKSUM_ON_COPY */
Yann 0:f30e2135b0db 498 /* reference the non-volatile payload data */
Yann 0:f30e2135b0db 499 concat_p->payload = (u8_t*)arg + pos;
Yann 0:f30e2135b0db 500 }
Yann 0:f30e2135b0db 501
Yann 0:f30e2135b0db 502 pos += seglen;
Yann 0:f30e2135b0db 503 queuelen += pbuf_clen(concat_p);
Yann 0:f30e2135b0db 504 }
Yann 0:f30e2135b0db 505 } else {
Yann 0:f30e2135b0db 506 #if TCP_OVERSIZE
Yann 0:f30e2135b0db 507 LWIP_ASSERT("unsent_oversize mismatch (pcb->unsent is NULL)",
Yann 0:f30e2135b0db 508 pcb->unsent_oversize == 0);
Yann 0:f30e2135b0db 509 #endif /* TCP_OVERSIZE */
Yann 0:f30e2135b0db 510 }
Yann 0:f30e2135b0db 511
Yann 0:f30e2135b0db 512 /*
Yann 0:f30e2135b0db 513 * Phase 3: Create new segments.
Yann 0:f30e2135b0db 514 *
Yann 0:f30e2135b0db 515 * The new segments are chained together in the local 'queue'
Yann 0:f30e2135b0db 516 * variable, ready to be appended to pcb->unsent.
Yann 0:f30e2135b0db 517 */
Yann 0:f30e2135b0db 518 while (pos < len) {
Yann 0:f30e2135b0db 519 struct pbuf *p;
Yann 0:f30e2135b0db 520 u16_t left = len - pos;
Yann 0:f30e2135b0db 521 u16_t max_len = pcb->mss - optlen;
Yann 0:f30e2135b0db 522 u16_t seglen = left > max_len ? max_len : left;
Yann 0:f30e2135b0db 523 #if TCP_CHECKSUM_ON_COPY
Yann 0:f30e2135b0db 524 u16_t chksum = 0;
Yann 0:f30e2135b0db 525 u8_t chksum_swapped = 0;
Yann 0:f30e2135b0db 526 #endif /* TCP_CHECKSUM_ON_COPY */
Yann 0:f30e2135b0db 527
Yann 0:f30e2135b0db 528 if (apiflags & TCP_WRITE_FLAG_COPY) {
Yann 0:f30e2135b0db 529 /* If copy is set, memory should be allocated and data copied
Yann 0:f30e2135b0db 530 * into pbuf */
Yann 0:f30e2135b0db 531 if ((p = tcp_pbuf_prealloc(PBUF_TRANSPORT, seglen + optlen, pcb->mss, &oversize, pcb, apiflags, queue == NULL)) == NULL) {
Yann 0:f30e2135b0db 532 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write : could not allocate memory for pbuf copy size %"U16_F"\n", seglen));
Yann 0:f30e2135b0db 533 goto memerr;
Yann 0:f30e2135b0db 534 }
Yann 0:f30e2135b0db 535 LWIP_ASSERT("tcp_write: check that first pbuf can hold the complete seglen",
Yann 0:f30e2135b0db 536 (p->len >= seglen));
Yann 0:f30e2135b0db 537 TCP_DATA_COPY2((char *)p->payload + optlen, (u8_t*)arg + pos, seglen, &chksum, &chksum_swapped);
Yann 0:f30e2135b0db 538 } else {
Yann 0:f30e2135b0db 539 /* Copy is not set: First allocate a pbuf for holding the data.
Yann 0:f30e2135b0db 540 * Since the referenced data is available at least until it is
Yann 0:f30e2135b0db 541 * sent out on the link (as it has to be ACKed by the remote
Yann 0:f30e2135b0db 542 * party) we can safely use PBUF_ROM instead of PBUF_REF here.
Yann 0:f30e2135b0db 543 */
Yann 0:f30e2135b0db 544 struct pbuf *p2;
Yann 0:f30e2135b0db 545 #if TCP_OVERSIZE
Yann 0:f30e2135b0db 546 LWIP_ASSERT("oversize == 0", oversize == 0);
Yann 0:f30e2135b0db 547 #endif /* TCP_OVERSIZE */
Yann 0:f30e2135b0db 548 if ((p2 = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_ROM)) == NULL) {
Yann 0:f30e2135b0db 549 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: could not allocate memory for zero-copy pbuf\n"));
Yann 0:f30e2135b0db 550 goto memerr;
Yann 0:f30e2135b0db 551 }
Yann 0:f30e2135b0db 552 #if TCP_CHECKSUM_ON_COPY
Yann 0:f30e2135b0db 553 /* calculate the checksum of nocopy-data */
Yann 0:f30e2135b0db 554 chksum = ~inet_chksum((u8_t*)arg + pos, seglen);
Yann 0:f30e2135b0db 555 #endif /* TCP_CHECKSUM_ON_COPY */
Yann 0:f30e2135b0db 556 /* reference the non-volatile payload data */
Yann 0:f30e2135b0db 557 p2->payload = (u8_t*)arg + pos;
Yann 0:f30e2135b0db 558
Yann 0:f30e2135b0db 559 /* Second, allocate a pbuf for the headers. */
Yann 0:f30e2135b0db 560 if ((p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) {
Yann 0:f30e2135b0db 561 /* If allocation fails, we have to deallocate the data pbuf as
Yann 0:f30e2135b0db 562 * well. */
Yann 0:f30e2135b0db 563 pbuf_free(p2);
Yann 0:f30e2135b0db 564 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: could not allocate memory for header pbuf\n"));
Yann 0:f30e2135b0db 565 goto memerr;
Yann 0:f30e2135b0db 566 }
Yann 0:f30e2135b0db 567 /* Concatenate the headers and data pbufs together. */
Yann 0:f30e2135b0db 568 pbuf_cat(p/*header*/, p2/*data*/);
Yann 0:f30e2135b0db 569 }
Yann 0:f30e2135b0db 570
Yann 0:f30e2135b0db 571 queuelen += pbuf_clen(p);
Yann 0:f30e2135b0db 572
Yann 0:f30e2135b0db 573 /* Now that there are more segments queued, we check again if the
Yann 0:f30e2135b0db 574 * length of the queue exceeds the configured maximum or
Yann 0:f30e2135b0db 575 * overflows. */
Yann 0:f30e2135b0db 576 if ((queuelen > TCP_SND_QUEUELEN) || (queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
Yann 0:f30e2135b0db 577 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_write: queue too long %"U16_F" (%"U16_F")\n", queuelen, TCP_SND_QUEUELEN));
Yann 0:f30e2135b0db 578 pbuf_free(p);
Yann 0:f30e2135b0db 579 goto memerr;
Yann 0:f30e2135b0db 580 }
Yann 0:f30e2135b0db 581
Yann 0:f30e2135b0db 582 if ((seg = tcp_create_segment(pcb, p, 0, pcb->snd_lbb + pos, optflags)) == NULL) {
Yann 0:f30e2135b0db 583 goto memerr;
Yann 0:f30e2135b0db 584 }
Yann 0:f30e2135b0db 585 #if TCP_OVERSIZE_DBGCHECK
Yann 0:f30e2135b0db 586 seg->oversize_left = oversize;
Yann 0:f30e2135b0db 587 #endif /* TCP_OVERSIZE_DBGCHECK */
Yann 0:f30e2135b0db 588 #if TCP_CHECKSUM_ON_COPY
Yann 0:f30e2135b0db 589 seg->chksum = chksum;
Yann 0:f30e2135b0db 590 seg->chksum_swapped = chksum_swapped;
Yann 0:f30e2135b0db 591 seg->flags |= TF_SEG_DATA_CHECKSUMMED;
Yann 0:f30e2135b0db 592 #endif /* TCP_CHECKSUM_ON_COPY */
Yann 0:f30e2135b0db 593 /* Fix dataptr for the nocopy case */
Yann 0:f30e2135b0db 594 if ((apiflags & TCP_WRITE_FLAG_COPY) == 0) {
Yann 0:f30e2135b0db 595 seg->dataptr = (u8_t*)arg + pos;
Yann 0:f30e2135b0db 596 }
Yann 0:f30e2135b0db 597
Yann 0:f30e2135b0db 598 /* first segment of to-be-queued data? */
Yann 0:f30e2135b0db 599 if (queue == NULL) {
Yann 0:f30e2135b0db 600 queue = seg;
Yann 0:f30e2135b0db 601 } else {
Yann 0:f30e2135b0db 602 /* Attach the segment to the end of the queued segments */
Yann 0:f30e2135b0db 603 LWIP_ASSERT("prev_seg != NULL", prev_seg != NULL);
Yann 0:f30e2135b0db 604 prev_seg->next = seg;
Yann 0:f30e2135b0db 605 }
Yann 0:f30e2135b0db 606 /* remember last segment of to-be-queued data for next iteration */
Yann 0:f30e2135b0db 607 prev_seg = seg;
Yann 0:f30e2135b0db 608
Yann 0:f30e2135b0db 609 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_TRACE, ("tcp_write: queueing %"U32_F":%"U32_F"\n",
Yann 0:f30e2135b0db 610 ntohl(seg->tcphdr->seqno),
Yann 0:f30e2135b0db 611 ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg)));
Yann 0:f30e2135b0db 612
Yann 0:f30e2135b0db 613 pos += seglen;
Yann 0:f30e2135b0db 614 }
Yann 0:f30e2135b0db 615
Yann 0:f30e2135b0db 616 /*
Yann 0:f30e2135b0db 617 * All three segmentation phases were successful. We can commit the
Yann 0:f30e2135b0db 618 * transaction.
Yann 0:f30e2135b0db 619 */
Yann 0:f30e2135b0db 620
Yann 0:f30e2135b0db 621 /*
Yann 0:f30e2135b0db 622 * Phase 1: If data has been added to the preallocated tail of
Yann 0:f30e2135b0db 623 * last_unsent, we update the length fields of the pbuf chain.
Yann 0:f30e2135b0db 624 */
Yann 0:f30e2135b0db 625 #if TCP_OVERSIZE
Yann 0:f30e2135b0db 626 if (oversize_used > 0) {
Yann 0:f30e2135b0db 627 struct pbuf *p;
Yann 0:f30e2135b0db 628 /* Bump tot_len of whole chain, len of tail */
Yann 0:f30e2135b0db 629 for (p = last_unsent->p; p; p = p->next) {
Yann 0:f30e2135b0db 630 p->tot_len += oversize_used;
Yann 0:f30e2135b0db 631 if (p->next == NULL) {
Yann 0:f30e2135b0db 632 TCP_DATA_COPY((char *)p->payload + p->len, arg, oversize_used, last_unsent);
Yann 0:f30e2135b0db 633 p->len += oversize_used;
Yann 0:f30e2135b0db 634 }
Yann 0:f30e2135b0db 635 }
Yann 0:f30e2135b0db 636 last_unsent->len += oversize_used;
Yann 0:f30e2135b0db 637 #if TCP_OVERSIZE_DBGCHECK
Yann 0:f30e2135b0db 638 last_unsent->oversize_left -= oversize_used;
Yann 0:f30e2135b0db 639 #endif /* TCP_OVERSIZE_DBGCHECK */
Yann 0:f30e2135b0db 640 }
Yann 0:f30e2135b0db 641 pcb->unsent_oversize = oversize;
Yann 0:f30e2135b0db 642 #endif /* TCP_OVERSIZE */
Yann 0:f30e2135b0db 643
Yann 0:f30e2135b0db 644 /*
Yann 0:f30e2135b0db 645 * Phase 2: concat_p can be concatenated onto last_unsent->p
Yann 0:f30e2135b0db 646 */
Yann 0:f30e2135b0db 647 if (concat_p != NULL) {
Yann 0:f30e2135b0db 648 LWIP_ASSERT("tcp_write: cannot concatenate when pcb->unsent is empty",
Yann 0:f30e2135b0db 649 (last_unsent != NULL));
Yann 0:f30e2135b0db 650 pbuf_cat(last_unsent->p, concat_p);
Yann 0:f30e2135b0db 651 last_unsent->len += concat_p->tot_len;
Yann 0:f30e2135b0db 652 #if TCP_CHECKSUM_ON_COPY
Yann 0:f30e2135b0db 653 if (concat_chksummed) {
Yann 0:f30e2135b0db 654 tcp_seg_add_chksum(concat_chksum, concat_chksummed, &last_unsent->chksum,
Yann 0:f30e2135b0db 655 &last_unsent->chksum_swapped);
Yann 0:f30e2135b0db 656 last_unsent->flags |= TF_SEG_DATA_CHECKSUMMED;
Yann 0:f30e2135b0db 657 }
Yann 0:f30e2135b0db 658 #endif /* TCP_CHECKSUM_ON_COPY */
Yann 0:f30e2135b0db 659 }
Yann 0:f30e2135b0db 660
Yann 0:f30e2135b0db 661 /*
Yann 0:f30e2135b0db 662 * Phase 3: Append queue to pcb->unsent. Queue may be NULL, but that
Yann 0:f30e2135b0db 663 * is harmless
Yann 0:f30e2135b0db 664 */
Yann 0:f30e2135b0db 665 if (last_unsent == NULL) {
Yann 0:f30e2135b0db 666 pcb->unsent = queue;
Yann 0:f30e2135b0db 667 } else {
Yann 0:f30e2135b0db 668 last_unsent->next = queue;
Yann 0:f30e2135b0db 669 }
Yann 0:f30e2135b0db 670
Yann 0:f30e2135b0db 671 /*
Yann 0:f30e2135b0db 672 * Finally update the pcb state.
Yann 0:f30e2135b0db 673 */
Yann 0:f30e2135b0db 674 pcb->snd_lbb += len;
Yann 0:f30e2135b0db 675 pcb->snd_buf -= len;
Yann 0:f30e2135b0db 676 pcb->snd_queuelen = queuelen;
Yann 0:f30e2135b0db 677
Yann 0:f30e2135b0db 678 LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_write: %"S16_F" (after enqueued)\n",
Yann 0:f30e2135b0db 679 pcb->snd_queuelen));
Yann 0:f30e2135b0db 680 if (pcb->snd_queuelen != 0) {
Yann 0:f30e2135b0db 681 LWIP_ASSERT("tcp_write: valid queue length",
Yann 0:f30e2135b0db 682 pcb->unacked != NULL || pcb->unsent != NULL);
Yann 0:f30e2135b0db 683 }
Yann 0:f30e2135b0db 684
Yann 0:f30e2135b0db 685 /* Set the PSH flag in the last segment that we enqueued. */
Yann 0:f30e2135b0db 686 if (seg != NULL && seg->tcphdr != NULL && ((apiflags & TCP_WRITE_FLAG_MORE)==0)) {
Yann 0:f30e2135b0db 687 TCPH_SET_FLAG(seg->tcphdr, TCP_PSH);
Yann 0:f30e2135b0db 688 }
Yann 0:f30e2135b0db 689
Yann 0:f30e2135b0db 690 return ERR_OK;
Yann 0:f30e2135b0db 691 memerr:
Yann 0:f30e2135b0db 692 pcb->flags |= TF_NAGLEMEMERR;
Yann 0:f30e2135b0db 693 TCP_STATS_INC(tcp.memerr);
Yann 0:f30e2135b0db 694
Yann 0:f30e2135b0db 695 if (concat_p != NULL) {
Yann 0:f30e2135b0db 696 pbuf_free(concat_p);
Yann 0:f30e2135b0db 697 }
Yann 0:f30e2135b0db 698 if (queue != NULL) {
Yann 0:f30e2135b0db 699 tcp_segs_free(queue);
Yann 0:f30e2135b0db 700 }
Yann 0:f30e2135b0db 701 if (pcb->snd_queuelen != 0) {
Yann 0:f30e2135b0db 702 LWIP_ASSERT("tcp_write: valid queue length", pcb->unacked != NULL ||
Yann 0:f30e2135b0db 703 pcb->unsent != NULL);
Yann 0:f30e2135b0db 704 }
Yann 0:f30e2135b0db 705 LWIP_DEBUGF(TCP_QLEN_DEBUG | LWIP_DBG_STATE, ("tcp_write: %"S16_F" (with mem err)\n", pcb->snd_queuelen));
Yann 0:f30e2135b0db 706 return ERR_MEM;
Yann 0:f30e2135b0db 707 }
Yann 0:f30e2135b0db 708
Yann 0:f30e2135b0db 709 /**
Yann 0:f30e2135b0db 710 * Enqueue TCP options for transmission.
Yann 0:f30e2135b0db 711 *
Yann 0:f30e2135b0db 712 * Called by tcp_connect(), tcp_listen_input(), and tcp_send_ctrl().
Yann 0:f30e2135b0db 713 *
Yann 0:f30e2135b0db 714 * @param pcb Protocol control block for the TCP connection.
Yann 0:f30e2135b0db 715 * @param flags TCP header flags to set in the outgoing segment.
Yann 0:f30e2135b0db 716 * @param optdata pointer to TCP options, or NULL.
Yann 0:f30e2135b0db 717 * @param optlen length of TCP options in bytes.
Yann 0:f30e2135b0db 718 */
Yann 0:f30e2135b0db 719 err_t
Yann 0:f30e2135b0db 720 tcp_enqueue_flags(struct tcp_pcb *pcb, u8_t flags)
Yann 0:f30e2135b0db 721 {
Yann 0:f30e2135b0db 722 struct pbuf *p;
Yann 0:f30e2135b0db 723 struct tcp_seg *seg;
Yann 0:f30e2135b0db 724 u8_t optflags = 0;
Yann 0:f30e2135b0db 725 u8_t optlen = 0;
Yann 0:f30e2135b0db 726
Yann 0:f30e2135b0db 727 LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue_flags: queuelen: %"U16_F"\n", (u16_t)pcb->snd_queuelen));
Yann 0:f30e2135b0db 728
Yann 0:f30e2135b0db 729 LWIP_ASSERT("tcp_enqueue_flags: need either TCP_SYN or TCP_FIN in flags (programmer violates API)",
Yann 0:f30e2135b0db 730 (flags & (TCP_SYN | TCP_FIN)) != 0);
Yann 0:f30e2135b0db 731
Yann 0:f30e2135b0db 732 /* check for configured max queuelen and possible overflow */
Yann 0:f30e2135b0db 733 if ((pcb->snd_queuelen >= TCP_SND_QUEUELEN) || (pcb->snd_queuelen > TCP_SNDQUEUELEN_OVERFLOW)) {
Yann 0:f30e2135b0db 734 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_enqueue_flags: too long queue %"U16_F" (max %"U16_F")\n",
Yann 0:f30e2135b0db 735 pcb->snd_queuelen, TCP_SND_QUEUELEN));
Yann 0:f30e2135b0db 736 TCP_STATS_INC(tcp.memerr);
Yann 0:f30e2135b0db 737 pcb->flags |= TF_NAGLEMEMERR;
Yann 0:f30e2135b0db 738 return ERR_MEM;
Yann 0:f30e2135b0db 739 }
Yann 0:f30e2135b0db 740
Yann 0:f30e2135b0db 741 if (flags & TCP_SYN) {
Yann 0:f30e2135b0db 742 optflags = TF_SEG_OPTS_MSS;
Yann 0:f30e2135b0db 743 }
Yann 0:f30e2135b0db 744 #if LWIP_TCP_TIMESTAMPS
Yann 0:f30e2135b0db 745 if ((pcb->flags & TF_TIMESTAMP)) {
Yann 0:f30e2135b0db 746 optflags |= TF_SEG_OPTS_TS;
Yann 0:f30e2135b0db 747 }
Yann 0:f30e2135b0db 748 #endif /* LWIP_TCP_TIMESTAMPS */
Yann 0:f30e2135b0db 749 optlen = LWIP_TCP_OPT_LENGTH(optflags);
Yann 0:f30e2135b0db 750
Yann 0:f30e2135b0db 751 /* tcp_enqueue_flags is always called with either SYN or FIN in flags.
Yann 0:f30e2135b0db 752 * We need one available snd_buf byte to do that.
Yann 0:f30e2135b0db 753 * This means we can't send FIN while snd_buf==0. A better fix would be to
Yann 0:f30e2135b0db 754 * not include SYN and FIN sequence numbers in the snd_buf count. */
Yann 0:f30e2135b0db 755 if (pcb->snd_buf == 0) {
Yann 0:f30e2135b0db 756 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 3, ("tcp_enqueue_flags: no send buffer available\n"));
Yann 0:f30e2135b0db 757 TCP_STATS_INC(tcp.memerr);
Yann 0:f30e2135b0db 758 return ERR_MEM;
Yann 0:f30e2135b0db 759 }
Yann 0:f30e2135b0db 760
Yann 0:f30e2135b0db 761 /* Allocate pbuf with room for TCP header + options */
Yann 0:f30e2135b0db 762 if ((p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) {
Yann 0:f30e2135b0db 763 pcb->flags |= TF_NAGLEMEMERR;
Yann 0:f30e2135b0db 764 TCP_STATS_INC(tcp.memerr);
Yann 0:f30e2135b0db 765 return ERR_MEM;
Yann 0:f30e2135b0db 766 }
Yann 0:f30e2135b0db 767 LWIP_ASSERT("tcp_enqueue_flags: check that first pbuf can hold optlen",
Yann 0:f30e2135b0db 768 (p->len >= optlen));
Yann 0:f30e2135b0db 769
Yann 0:f30e2135b0db 770 /* Allocate memory for tcp_seg, and fill in fields. */
Yann 0:f30e2135b0db 771 if ((seg = tcp_create_segment(pcb, p, flags, pcb->snd_lbb, optflags)) == NULL) {
Yann 0:f30e2135b0db 772 pcb->flags |= TF_NAGLEMEMERR;
Yann 0:f30e2135b0db 773 TCP_STATS_INC(tcp.memerr);
Yann 0:f30e2135b0db 774 return ERR_MEM;
Yann 0:f30e2135b0db 775 }
Yann 0:f30e2135b0db 776 LWIP_ASSERT("tcp_enqueue_flags: invalid segment length", seg->len == 0);
Yann 0:f30e2135b0db 777
Yann 0:f30e2135b0db 778 LWIP_DEBUGF(TCP_OUTPUT_DEBUG | LWIP_DBG_TRACE,
Yann 0:f30e2135b0db 779 ("tcp_enqueue_flags: queueing %"U32_F":%"U32_F" (0x%"X16_F")\n",
Yann 0:f30e2135b0db 780 ntohl(seg->tcphdr->seqno),
Yann 0:f30e2135b0db 781 ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg),
Yann 0:f30e2135b0db 782 (u16_t)flags));
Yann 0:f30e2135b0db 783
Yann 0:f30e2135b0db 784 /* Now append seg to pcb->unsent queue */
Yann 0:f30e2135b0db 785 if (pcb->unsent == NULL) {
Yann 0:f30e2135b0db 786 pcb->unsent = seg;
Yann 0:f30e2135b0db 787 } else {
Yann 0:f30e2135b0db 788 struct tcp_seg *useg;
Yann 0:f30e2135b0db 789 for (useg = pcb->unsent; useg->next != NULL; useg = useg->next);
Yann 0:f30e2135b0db 790 useg->next = seg;
Yann 0:f30e2135b0db 791 }
Yann 0:f30e2135b0db 792 #if TCP_OVERSIZE
Yann 0:f30e2135b0db 793 /* The new unsent tail has no space */
Yann 0:f30e2135b0db 794 pcb->unsent_oversize = 0;
Yann 0:f30e2135b0db 795 #endif /* TCP_OVERSIZE */
Yann 0:f30e2135b0db 796
Yann 0:f30e2135b0db 797 /* SYN and FIN bump the sequence number */
Yann 0:f30e2135b0db 798 if ((flags & TCP_SYN) || (flags & TCP_FIN)) {
Yann 0:f30e2135b0db 799 pcb->snd_lbb++;
Yann 0:f30e2135b0db 800 /* optlen does not influence snd_buf */
Yann 0:f30e2135b0db 801 pcb->snd_buf--;
Yann 0:f30e2135b0db 802 }
Yann 0:f30e2135b0db 803 if (flags & TCP_FIN) {
Yann 0:f30e2135b0db 804 pcb->flags |= TF_FIN;
Yann 0:f30e2135b0db 805 }
Yann 0:f30e2135b0db 806
Yann 0:f30e2135b0db 807 /* update number of segments on the queues */
Yann 0:f30e2135b0db 808 pcb->snd_queuelen += pbuf_clen(seg->p);
Yann 0:f30e2135b0db 809 LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue_flags: %"S16_F" (after enqueued)\n", pcb->snd_queuelen));
Yann 0:f30e2135b0db 810 if (pcb->snd_queuelen != 0) {
Yann 0:f30e2135b0db 811 LWIP_ASSERT("tcp_enqueue_flags: invalid queue length",
Yann 0:f30e2135b0db 812 pcb->unacked != NULL || pcb->unsent != NULL);
Yann 0:f30e2135b0db 813 }
Yann 0:f30e2135b0db 814
Yann 0:f30e2135b0db 815 return ERR_OK;
Yann 0:f30e2135b0db 816 }
Yann 0:f30e2135b0db 817
Yann 0:f30e2135b0db 818
Yann 0:f30e2135b0db 819 #if LWIP_TCP_TIMESTAMPS
Yann 0:f30e2135b0db 820 /* Build a timestamp option (12 bytes long) at the specified options pointer)
Yann 0:f30e2135b0db 821 *
Yann 0:f30e2135b0db 822 * @param pcb tcp_pcb
Yann 0:f30e2135b0db 823 * @param opts option pointer where to store the timestamp option
Yann 0:f30e2135b0db 824 */
Yann 0:f30e2135b0db 825 static void
Yann 0:f30e2135b0db 826 tcp_build_timestamp_option(struct tcp_pcb *pcb, u32_t *opts)
Yann 0:f30e2135b0db 827 {
Yann 0:f30e2135b0db 828 /* Pad with two NOP options to make everything nicely aligned */
Yann 0:f30e2135b0db 829 opts[0] = PP_HTONL(0x0101080A);
Yann 0:f30e2135b0db 830 opts[1] = htonl(sys_now());
Yann 0:f30e2135b0db 831 opts[2] = htonl(pcb->ts_recent);
Yann 0:f30e2135b0db 832 }
Yann 0:f30e2135b0db 833 #endif
Yann 0:f30e2135b0db 834
Yann 0:f30e2135b0db 835 /** Send an ACK without data.
Yann 0:f30e2135b0db 836 *
Yann 0:f30e2135b0db 837 * @param pcb Protocol control block for the TCP connection to send the ACK
Yann 0:f30e2135b0db 838 */
Yann 0:f30e2135b0db 839 err_t
Yann 0:f30e2135b0db 840 tcp_send_empty_ack(struct tcp_pcb *pcb)
Yann 0:f30e2135b0db 841 {
Yann 0:f30e2135b0db 842 struct pbuf *p;
Yann 0:f30e2135b0db 843 struct tcp_hdr *tcphdr;
Yann 0:f30e2135b0db 844 u8_t optlen = 0;
Yann 0:f30e2135b0db 845
Yann 0:f30e2135b0db 846 #if LWIP_TCP_TIMESTAMPS
Yann 0:f30e2135b0db 847 if (pcb->flags & TF_TIMESTAMP) {
Yann 0:f30e2135b0db 848 optlen = LWIP_TCP_OPT_LENGTH(TF_SEG_OPTS_TS);
Yann 0:f30e2135b0db 849 }
Yann 0:f30e2135b0db 850 #endif
Yann 0:f30e2135b0db 851
Yann 0:f30e2135b0db 852 p = tcp_output_alloc_header(pcb, optlen, 0, htonl(pcb->snd_nxt));
Yann 0:f30e2135b0db 853 if (p == NULL) {
Yann 0:f30e2135b0db 854 LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: (ACK) could not allocate pbuf\n"));
Yann 0:f30e2135b0db 855 return ERR_BUF;
Yann 0:f30e2135b0db 856 }
Yann 0:f30e2135b0db 857 tcphdr = (struct tcp_hdr *)p->payload;
Yann 0:f30e2135b0db 858 LWIP_DEBUGF(TCP_OUTPUT_DEBUG,
Yann 0:f30e2135b0db 859 ("tcp_output: sending ACK for %"U32_F"\n", pcb->rcv_nxt));
Yann 0:f30e2135b0db 860 /* remove ACK flags from the PCB, as we send an empty ACK now */
Yann 0:f30e2135b0db 861 pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
Yann 0:f30e2135b0db 862
Yann 0:f30e2135b0db 863 /* NB. MSS option is only sent on SYNs, so ignore it here */
Yann 0:f30e2135b0db 864 #if LWIP_TCP_TIMESTAMPS
Yann 0:f30e2135b0db 865 pcb->ts_lastacksent = pcb->rcv_nxt;
Yann 0:f30e2135b0db 866
Yann 0:f30e2135b0db 867 if (pcb->flags & TF_TIMESTAMP) {
Yann 0:f30e2135b0db 868 tcp_build_timestamp_option(pcb, (u32_t *)(tcphdr + 1));
Yann 0:f30e2135b0db 869 }
Yann 0:f30e2135b0db 870 #endif
Yann 0:f30e2135b0db 871
Yann 0:f30e2135b0db 872 #if CHECKSUM_GEN_TCP
Yann 0:f30e2135b0db 873 tcphdr->chksum = inet_chksum_pseudo(p, &(pcb->local_ip), &(pcb->remote_ip),
Yann 0:f30e2135b0db 874 IP_PROTO_TCP, p->tot_len);
Yann 0:f30e2135b0db 875 #endif
Yann 0:f30e2135b0db 876 #if LWIP_NETIF_HWADDRHINT
Yann 0:f30e2135b0db 877 ip_output_hinted(p, &(pcb->local_ip), &(pcb->remote_ip), pcb->ttl, pcb->tos,
Yann 0:f30e2135b0db 878 IP_PROTO_TCP, &(pcb->addr_hint));
Yann 0:f30e2135b0db 879 #else /* LWIP_NETIF_HWADDRHINT*/
Yann 0:f30e2135b0db 880 ip_output(p, &(pcb->local_ip), &(pcb->remote_ip), pcb->ttl, pcb->tos,
Yann 0:f30e2135b0db 881 IP_PROTO_TCP);
Yann 0:f30e2135b0db 882 #endif /* LWIP_NETIF_HWADDRHINT*/
Yann 0:f30e2135b0db 883 pbuf_free(p);
Yann 0:f30e2135b0db 884
Yann 0:f30e2135b0db 885 return ERR_OK;
Yann 0:f30e2135b0db 886 }
Yann 0:f30e2135b0db 887
Yann 0:f30e2135b0db 888 /**
Yann 0:f30e2135b0db 889 * Find out what we can send and send it
Yann 0:f30e2135b0db 890 *
Yann 0:f30e2135b0db 891 * @param pcb Protocol control block for the TCP connection to send data
Yann 0:f30e2135b0db 892 * @return ERR_OK if data has been sent or nothing to send
Yann 0:f30e2135b0db 893 * another err_t on error
Yann 0:f30e2135b0db 894 */
Yann 0:f30e2135b0db 895 err_t
Yann 0:f30e2135b0db 896 tcp_output(struct tcp_pcb *pcb)
Yann 0:f30e2135b0db 897 {
Yann 0:f30e2135b0db 898 struct tcp_seg *seg, *useg;
Yann 0:f30e2135b0db 899 u32_t wnd, snd_nxt;
Yann 0:f30e2135b0db 900 #if TCP_CWND_DEBUG
Yann 0:f30e2135b0db 901 s16_t i = 0;
Yann 0:f30e2135b0db 902 #endif /* TCP_CWND_DEBUG */
Yann 0:f30e2135b0db 903
Yann 0:f30e2135b0db 904 /* First, check if we are invoked by the TCP input processing
Yann 0:f30e2135b0db 905 code. If so, we do not output anything. Instead, we rely on the
Yann 0:f30e2135b0db 906 input processing code to call us when input processing is done
Yann 0:f30e2135b0db 907 with. */
Yann 0:f30e2135b0db 908 if (tcp_input_pcb == pcb) {
Yann 0:f30e2135b0db 909 return ERR_OK;
Yann 0:f30e2135b0db 910 }
Yann 0:f30e2135b0db 911
Yann 0:f30e2135b0db 912 wnd = LWIP_MIN(pcb->snd_wnd, pcb->cwnd);
Yann 0:f30e2135b0db 913
Yann 0:f30e2135b0db 914 seg = pcb->unsent;
Yann 0:f30e2135b0db 915
Yann 0:f30e2135b0db 916 /* If the TF_ACK_NOW flag is set and no data will be sent (either
Yann 0:f30e2135b0db 917 * because the ->unsent queue is empty or because the window does
Yann 0:f30e2135b0db 918 * not allow it), construct an empty ACK segment and send it.
Yann 0:f30e2135b0db 919 *
Yann 0:f30e2135b0db 920 * If data is to be sent, we will just piggyback the ACK (see below).
Yann 0:f30e2135b0db 921 */
Yann 0:f30e2135b0db 922 if (pcb->flags & TF_ACK_NOW &&
Yann 0:f30e2135b0db 923 (seg == NULL ||
Yann 0:f30e2135b0db 924 ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len > wnd)) {
Yann 0:f30e2135b0db 925 return tcp_send_empty_ack(pcb);
Yann 0:f30e2135b0db 926 }
Yann 0:f30e2135b0db 927
Yann 0:f30e2135b0db 928 /* useg should point to last segment on unacked queue */
Yann 0:f30e2135b0db 929 useg = pcb->unacked;
Yann 0:f30e2135b0db 930 if (useg != NULL) {
Yann 0:f30e2135b0db 931 for (; useg->next != NULL; useg = useg->next);
Yann 0:f30e2135b0db 932 }
Yann 0:f30e2135b0db 933
Yann 0:f30e2135b0db 934 #if TCP_OUTPUT_DEBUG
Yann 0:f30e2135b0db 935 if (seg == NULL) {
Yann 0:f30e2135b0db 936 LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: nothing to send (%p)\n",
Yann 0:f30e2135b0db 937 (void*)pcb->unsent));
Yann 0:f30e2135b0db 938 }
Yann 0:f30e2135b0db 939 #endif /* TCP_OUTPUT_DEBUG */
Yann 0:f30e2135b0db 940 #if TCP_CWND_DEBUG
Yann 0:f30e2135b0db 941 if (seg == NULL) {
Yann 0:f30e2135b0db 942 LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_output: snd_wnd %"U16_F
Yann 0:f30e2135b0db 943 ", cwnd %"U16_F", wnd %"U32_F
Yann 0:f30e2135b0db 944 ", seg == NULL, ack %"U32_F"\n",
Yann 0:f30e2135b0db 945 pcb->snd_wnd, pcb->cwnd, wnd, pcb->lastack));
Yann 0:f30e2135b0db 946 } else {
Yann 0:f30e2135b0db 947 LWIP_DEBUGF(TCP_CWND_DEBUG,
Yann 0:f30e2135b0db 948 ("tcp_output: snd_wnd %"U16_F", cwnd %"U16_F", wnd %"U32_F
Yann 0:f30e2135b0db 949 ", effwnd %"U32_F", seq %"U32_F", ack %"U32_F"\n",
Yann 0:f30e2135b0db 950 pcb->snd_wnd, pcb->cwnd, wnd,
Yann 0:f30e2135b0db 951 ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len,
Yann 0:f30e2135b0db 952 ntohl(seg->tcphdr->seqno), pcb->lastack));
Yann 0:f30e2135b0db 953 }
Yann 0:f30e2135b0db 954 #endif /* TCP_CWND_DEBUG */
Yann 0:f30e2135b0db 955 /* data available and window allows it to be sent? */
Yann 0:f30e2135b0db 956 while (seg != NULL &&
Yann 0:f30e2135b0db 957 ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len <= wnd) {
Yann 0:f30e2135b0db 958 LWIP_ASSERT("RST not expected here!",
Yann 0:f30e2135b0db 959 (TCPH_FLAGS(seg->tcphdr) & TCP_RST) == 0);
Yann 0:f30e2135b0db 960 /* Stop sending if the nagle algorithm would prevent it
Yann 0:f30e2135b0db 961 * Don't stop:
Yann 0:f30e2135b0db 962 * - if tcp_write had a memory error before (prevent delayed ACK timeout) or
Yann 0:f30e2135b0db 963 * - if FIN was already enqueued for this PCB (SYN is always alone in a segment -
Yann 0:f30e2135b0db 964 * either seg->next != NULL or pcb->unacked == NULL;
Yann 0:f30e2135b0db 965 * RST is no sent using tcp_write/tcp_output.
Yann 0:f30e2135b0db 966 */
Yann 0:f30e2135b0db 967 if((tcp_do_output_nagle(pcb) == 0) &&
Yann 0:f30e2135b0db 968 ((pcb->flags & (TF_NAGLEMEMERR | TF_FIN)) == 0)){
Yann 0:f30e2135b0db 969 break;
Yann 0:f30e2135b0db 970 }
Yann 0:f30e2135b0db 971 #if TCP_CWND_DEBUG
Yann 0:f30e2135b0db 972 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",
Yann 0:f30e2135b0db 973 pcb->snd_wnd, pcb->cwnd, wnd,
Yann 0:f30e2135b0db 974 ntohl(seg->tcphdr->seqno) + seg->len -
Yann 0:f30e2135b0db 975 pcb->lastack,
Yann 0:f30e2135b0db 976 ntohl(seg->tcphdr->seqno), pcb->lastack, i));
Yann 0:f30e2135b0db 977 ++i;
Yann 0:f30e2135b0db 978 #endif /* TCP_CWND_DEBUG */
Yann 0:f30e2135b0db 979
Yann 0:f30e2135b0db 980 pcb->unsent = seg->next;
Yann 0:f30e2135b0db 981
Yann 0:f30e2135b0db 982 if (pcb->state != SYN_SENT) {
Yann 0:f30e2135b0db 983 TCPH_SET_FLAG(seg->tcphdr, TCP_ACK);
Yann 0:f30e2135b0db 984 pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
Yann 0:f30e2135b0db 985 }
Yann 0:f30e2135b0db 986
Yann 0:f30e2135b0db 987 tcp_output_segment(seg, pcb);
Yann 0:f30e2135b0db 988
Yann 0:f30e2135b0db 989 snd_nxt = ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg);
Yann 0:f30e2135b0db 990
Yann 0:f30e2135b0db 991 LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: pcb->snd_nxt was %"U32_F" seqno=%"U32_F" len=%"U32_F" new snd_nxt=%"U32_F"\n", //DG
Yann 0:f30e2135b0db 992 pcb->snd_nxt, ntohl(seg->tcphdr->seqno), TCP_TCPLEN(seg), snd_nxt));
Yann 0:f30e2135b0db 993
Yann 0:f30e2135b0db 994 if (TCP_SEQ_LT(pcb->snd_nxt, snd_nxt)) {
Yann 0:f30e2135b0db 995 pcb->snd_nxt = snd_nxt;
Yann 0:f30e2135b0db 996 }
Yann 0:f30e2135b0db 997 /* put segment on unacknowledged list if length > 0 */
Yann 0:f30e2135b0db 998 if (TCP_TCPLEN(seg) > 0) {
Yann 0:f30e2135b0db 999 seg->next = NULL;
Yann 0:f30e2135b0db 1000 /* unacked list is empty? */
Yann 0:f30e2135b0db 1001 if (pcb->unacked == NULL) {
Yann 0:f30e2135b0db 1002 pcb->unacked = seg;
Yann 0:f30e2135b0db 1003 useg = seg;
Yann 0:f30e2135b0db 1004 /* unacked list is not empty? */
Yann 0:f30e2135b0db 1005 } else {
Yann 0:f30e2135b0db 1006 /* In the case of fast retransmit, the packet should not go to the tail
Yann 0:f30e2135b0db 1007 * of the unacked queue, but rather somewhere before it. We need to check for
Yann 0:f30e2135b0db 1008 * this case. -STJ Jul 27, 2004 */
Yann 0:f30e2135b0db 1009 if (TCP_SEQ_LT(ntohl(seg->tcphdr->seqno), ntohl(useg->tcphdr->seqno))) {
Yann 0:f30e2135b0db 1010 /* add segment to before tail of unacked list, keeping the list sorted */
Yann 0:f30e2135b0db 1011 struct tcp_seg **cur_seg = &(pcb->unacked);
Yann 0:f30e2135b0db 1012 while (*cur_seg &&
Yann 0:f30e2135b0db 1013 TCP_SEQ_LT(ntohl((*cur_seg)->tcphdr->seqno), ntohl(seg->tcphdr->seqno))) {
Yann 0:f30e2135b0db 1014 cur_seg = &((*cur_seg)->next );
Yann 0:f30e2135b0db 1015 }
Yann 0:f30e2135b0db 1016 seg->next = (*cur_seg);
Yann 0:f30e2135b0db 1017 (*cur_seg) = seg;
Yann 0:f30e2135b0db 1018 } else {
Yann 0:f30e2135b0db 1019 /* add segment to tail of unacked list */
Yann 0:f30e2135b0db 1020 useg->next = seg;
Yann 0:f30e2135b0db 1021 useg = useg->next;
Yann 0:f30e2135b0db 1022 }
Yann 0:f30e2135b0db 1023 }
Yann 0:f30e2135b0db 1024 /* do not queue empty segments on the unacked list */
Yann 0:f30e2135b0db 1025 } else {
Yann 0:f30e2135b0db 1026 tcp_seg_free(seg);
Yann 0:f30e2135b0db 1027 }
Yann 0:f30e2135b0db 1028 seg = pcb->unsent;
Yann 0:f30e2135b0db 1029 }
Yann 0:f30e2135b0db 1030 #if TCP_OVERSIZE
Yann 0:f30e2135b0db 1031 if (pcb->unsent == NULL) {
Yann 0:f30e2135b0db 1032 /* last unsent has been removed, reset unsent_oversize */
Yann 0:f30e2135b0db 1033 pcb->unsent_oversize = 0;
Yann 0:f30e2135b0db 1034 }
Yann 0:f30e2135b0db 1035 #endif /* TCP_OVERSIZE */
Yann 0:f30e2135b0db 1036
Yann 0:f30e2135b0db 1037 if (seg != NULL && pcb->persist_backoff == 0 &&
Yann 0:f30e2135b0db 1038 ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len > pcb->snd_wnd) {
Yann 0:f30e2135b0db 1039 /* prepare for persist timer */
Yann 0:f30e2135b0db 1040 pcb->persist_cnt = 0;
Yann 0:f30e2135b0db 1041 pcb->persist_backoff = 1;
Yann 0:f30e2135b0db 1042 }
Yann 0:f30e2135b0db 1043
Yann 0:f30e2135b0db 1044 pcb->flags &= ~TF_NAGLEMEMERR;
Yann 0:f30e2135b0db 1045 return ERR_OK;
Yann 0:f30e2135b0db 1046 }
Yann 0:f30e2135b0db 1047
Yann 0:f30e2135b0db 1048 /**
Yann 0:f30e2135b0db 1049 * Called by tcp_output() to actually send a TCP segment over IP.
Yann 0:f30e2135b0db 1050 *
Yann 0:f30e2135b0db 1051 * @param seg the tcp_seg to send
Yann 0:f30e2135b0db 1052 * @param pcb the tcp_pcb for the TCP connection used to send the segment
Yann 0:f30e2135b0db 1053 */
Yann 0:f30e2135b0db 1054 static void
Yann 0:f30e2135b0db 1055 tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb)
Yann 0:f30e2135b0db 1056 {
Yann 0:f30e2135b0db 1057 u16_t len;
Yann 0:f30e2135b0db 1058 struct netif *netif;
Yann 0:f30e2135b0db 1059 u32_t *opts;
Yann 0:f30e2135b0db 1060
Yann 0:f30e2135b0db 1061 /** @bug Exclude retransmitted segments from this count. */
Yann 0:f30e2135b0db 1062 snmp_inc_tcpoutsegs();
Yann 0:f30e2135b0db 1063
Yann 0:f30e2135b0db 1064 /* The TCP header has already been constructed, but the ackno and
Yann 0:f30e2135b0db 1065 wnd fields remain. */
Yann 0:f30e2135b0db 1066 seg->tcphdr->ackno = htonl(pcb->rcv_nxt);
Yann 0:f30e2135b0db 1067
Yann 0:f30e2135b0db 1068 /* advertise our receive window size in this TCP segment */
Yann 0:f30e2135b0db 1069 seg->tcphdr->wnd = htons(pcb->rcv_ann_wnd);
Yann 0:f30e2135b0db 1070
Yann 0:f30e2135b0db 1071 pcb->rcv_ann_right_edge = pcb->rcv_nxt + pcb->rcv_ann_wnd;
Yann 0:f30e2135b0db 1072
Yann 0:f30e2135b0db 1073 /* Add any requested options. NB MSS option is only set on SYN
Yann 0:f30e2135b0db 1074 packets, so ignore it here */
Yann 0:f30e2135b0db 1075 LWIP_ASSERT("seg->tcphdr not aligned", ((mem_ptr_t)(seg->tcphdr + 1) % 4) == 0);
Yann 0:f30e2135b0db 1076 opts = (u32_t *)(void *)(seg->tcphdr + 1);
Yann 0:f30e2135b0db 1077 if (seg->flags & TF_SEG_OPTS_MSS) {
Yann 0:f30e2135b0db 1078 TCP_BUILD_MSS_OPTION(*opts);
Yann 0:f30e2135b0db 1079 opts += 1;
Yann 0:f30e2135b0db 1080 }
Yann 0:f30e2135b0db 1081 #if LWIP_TCP_TIMESTAMPS
Yann 0:f30e2135b0db 1082 pcb->ts_lastacksent = pcb->rcv_nxt;
Yann 0:f30e2135b0db 1083
Yann 0:f30e2135b0db 1084 if (seg->flags & TF_SEG_OPTS_TS) {
Yann 0:f30e2135b0db 1085 tcp_build_timestamp_option(pcb, opts);
Yann 0:f30e2135b0db 1086 opts += 3;
Yann 0:f30e2135b0db 1087 }
Yann 0:f30e2135b0db 1088 #endif
Yann 0:f30e2135b0db 1089
Yann 0:f30e2135b0db 1090 /* If we don't have a local IP address, we get one by
Yann 0:f30e2135b0db 1091 calling ip_route(). */
Yann 0:f30e2135b0db 1092 if (ip_addr_isany(&(pcb->local_ip))) {
Yann 0:f30e2135b0db 1093 netif = ip_route(&(pcb->remote_ip));
Yann 0:f30e2135b0db 1094 if (netif == NULL) {
Yann 0:f30e2135b0db 1095 return;
Yann 0:f30e2135b0db 1096 }
Yann 0:f30e2135b0db 1097 ip_addr_copy(pcb->local_ip, netif->ip_addr);
Yann 0:f30e2135b0db 1098 }
Yann 0:f30e2135b0db 1099
Yann 0:f30e2135b0db 1100 /* Set retransmission timer running if it is not currently enabled */
Yann 0:f30e2135b0db 1101 if(pcb->rtime == -1) {
Yann 0:f30e2135b0db 1102 pcb->rtime = 0;
Yann 0:f30e2135b0db 1103 }
Yann 0:f30e2135b0db 1104
Yann 0:f30e2135b0db 1105 if (pcb->rttest == 0) {
Yann 0:f30e2135b0db 1106 pcb->rttest = tcp_ticks;
Yann 0:f30e2135b0db 1107 pcb->rtseq = ntohl(seg->tcphdr->seqno);
Yann 0:f30e2135b0db 1108
Yann 0:f30e2135b0db 1109 LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_output_segment: rtseq %"U32_F"\n", pcb->rtseq));
Yann 0:f30e2135b0db 1110 }
Yann 0:f30e2135b0db 1111 LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output_segment: %"U32_F":%"U32_F"\n",
Yann 0:f30e2135b0db 1112 htonl(seg->tcphdr->seqno), htonl(seg->tcphdr->seqno) +
Yann 0:f30e2135b0db 1113 seg->len));
Yann 0:f30e2135b0db 1114
Yann 0:f30e2135b0db 1115 len = (u16_t)((u8_t *)seg->tcphdr - (u8_t *)seg->p->payload);
Yann 0:f30e2135b0db 1116
Yann 0:f30e2135b0db 1117 seg->p->len -= len;
Yann 0:f30e2135b0db 1118 seg->p->tot_len -= len;
Yann 0:f30e2135b0db 1119
Yann 0:f30e2135b0db 1120 seg->p->payload = seg->tcphdr;
Yann 0:f30e2135b0db 1121
Yann 0:f30e2135b0db 1122 seg->tcphdr->chksum = 0;
Yann 0:f30e2135b0db 1123 #if CHECKSUM_GEN_TCP
Yann 0:f30e2135b0db 1124 #if TCP_CHECKSUM_ON_COPY
Yann 0:f30e2135b0db 1125 {
Yann 0:f30e2135b0db 1126 u32_t acc;
Yann 0:f30e2135b0db 1127 #if TCP_CHECKSUM_ON_COPY_SANITY_CHECK
Yann 0:f30e2135b0db 1128 u16_t chksum_slow = inet_chksum_pseudo(seg->p, &(pcb->local_ip),
Yann 0:f30e2135b0db 1129 &(pcb->remote_ip),
Yann 0:f30e2135b0db 1130 IP_PROTO_TCP, seg->p->tot_len);
Yann 0:f30e2135b0db 1131 #endif /* TCP_CHECKSUM_ON_COPY_SANITY_CHECK */
Yann 0:f30e2135b0db 1132 if ((seg->flags & TF_SEG_DATA_CHECKSUMMED) == 0) {
Yann 0:f30e2135b0db 1133 LWIP_ASSERT("data included but not checksummed",
Yann 0:f30e2135b0db 1134 seg->p->tot_len == (TCPH_HDRLEN(seg->tcphdr) * 4));
Yann 0:f30e2135b0db 1135 }
Yann 0:f30e2135b0db 1136
Yann 0:f30e2135b0db 1137 /* rebuild TCP header checksum (TCP header changes for retransmissions!) */
Yann 0:f30e2135b0db 1138 acc = inet_chksum_pseudo_partial(seg->p, &(pcb->local_ip),
Yann 0:f30e2135b0db 1139 &(pcb->remote_ip),
Yann 0:f30e2135b0db 1140 IP_PROTO_TCP, seg->p->tot_len, TCPH_HDRLEN(seg->tcphdr) * 4);
Yann 0:f30e2135b0db 1141 /* add payload checksum */
Yann 0:f30e2135b0db 1142 if (seg->chksum_swapped) {
Yann 0:f30e2135b0db 1143 seg->chksum = SWAP_BYTES_IN_WORD(seg->chksum);
Yann 0:f30e2135b0db 1144 seg->chksum_swapped = 0;
Yann 0:f30e2135b0db 1145 }
Yann 0:f30e2135b0db 1146 acc += (u16_t)~(seg->chksum);
Yann 0:f30e2135b0db 1147 seg->tcphdr->chksum = FOLD_U32T(acc);
Yann 0:f30e2135b0db 1148 #if TCP_CHECKSUM_ON_COPY_SANITY_CHECK
Yann 0:f30e2135b0db 1149 if (chksum_slow != seg->tcphdr->chksum) {
Yann 0:f30e2135b0db 1150 LWIP_DEBUGF(TCP_DEBUG | LWIP_DBG_LEVEL_WARNING,
Yann 0:f30e2135b0db 1151 ("tcp_output_segment: calculated checksum is %"X16_F" instead of %"X16_F"\n",
Yann 0:f30e2135b0db 1152 seg->tcphdr->chksum, chksum_slow));
Yann 0:f30e2135b0db 1153 seg->tcphdr->chksum = chksum_slow;
Yann 0:f30e2135b0db 1154 }
Yann 0:f30e2135b0db 1155 #endif /* TCP_CHECKSUM_ON_COPY_SANITY_CHECK */
Yann 0:f30e2135b0db 1156 }
Yann 0:f30e2135b0db 1157 #else /* TCP_CHECKSUM_ON_COPY */
Yann 0:f30e2135b0db 1158 seg->tcphdr->chksum = inet_chksum_pseudo(seg->p, &(pcb->local_ip),
Yann 0:f30e2135b0db 1159 &(pcb->remote_ip),
Yann 0:f30e2135b0db 1160 IP_PROTO_TCP, seg->p->tot_len);
Yann 0:f30e2135b0db 1161 #endif /* TCP_CHECKSUM_ON_COPY */
Yann 0:f30e2135b0db 1162 #endif /* CHECKSUM_GEN_TCP */
Yann 0:f30e2135b0db 1163 TCP_STATS_INC(tcp.xmit);
Yann 0:f30e2135b0db 1164
Yann 0:f30e2135b0db 1165 LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output_segment: Before ip_out seqno = %"U32_F"\n",
Yann 0:f30e2135b0db 1166 htonl(seg->tcphdr->seqno))); //DG
Yann 0:f30e2135b0db 1167
Yann 0:f30e2135b0db 1168 #if LWIP_NETIF_HWADDRHINT
Yann 0:f30e2135b0db 1169 ip_output_hinted(seg->p, &(pcb->local_ip), &(pcb->remote_ip), pcb->ttl, pcb->tos,
Yann 0:f30e2135b0db 1170 IP_PROTO_TCP, &(pcb->addr_hint));
Yann 0:f30e2135b0db 1171 #else /* LWIP_NETIF_HWADDRHINT*/
Yann 0:f30e2135b0db 1172 ip_output(seg->p, &(pcb->local_ip), &(pcb->remote_ip), pcb->ttl, pcb->tos,
Yann 0:f30e2135b0db 1173 IP_PROTO_TCP);
Yann 0:f30e2135b0db 1174 #endif /* LWIP_NETIF_HWADDRHINT*/
Yann 0:f30e2135b0db 1175
Yann 0:f30e2135b0db 1176 LWIP_DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output_segment: After ip_out seqno = %"U32_F"\n",
Yann 0:f30e2135b0db 1177 htonl(seg->tcphdr->seqno))); //DG
Yann 0:f30e2135b0db 1178
Yann 0:f30e2135b0db 1179
Yann 0:f30e2135b0db 1180 }
Yann 0:f30e2135b0db 1181
Yann 0:f30e2135b0db 1182 /**
Yann 0:f30e2135b0db 1183 * Send a TCP RESET packet (empty segment with RST flag set) either to
Yann 0:f30e2135b0db 1184 * abort a connection or to show that there is no matching local connection
Yann 0:f30e2135b0db 1185 * for a received segment.
Yann 0:f30e2135b0db 1186 *
Yann 0:f30e2135b0db 1187 * Called by tcp_abort() (to abort a local connection), tcp_input() (if no
Yann 0:f30e2135b0db 1188 * matching local pcb was found), tcp_listen_input() (if incoming segment
Yann 0:f30e2135b0db 1189 * has ACK flag set) and tcp_process() (received segment in the wrong state)
Yann 0:f30e2135b0db 1190 *
Yann 0:f30e2135b0db 1191 * Since a RST segment is in most cases not sent for an active connection,
Yann 0:f30e2135b0db 1192 * tcp_rst() has a number of arguments that are taken from a tcp_pcb for
Yann 0:f30e2135b0db 1193 * most other segment output functions.
Yann 0:f30e2135b0db 1194 *
Yann 0:f30e2135b0db 1195 * @param seqno the sequence number to use for the outgoing segment
Yann 0:f30e2135b0db 1196 * @param ackno the acknowledge number to use for the outgoing segment
Yann 0:f30e2135b0db 1197 * @param local_ip the local IP address to send the segment from
Yann 0:f30e2135b0db 1198 * @param remote_ip the remote IP address to send the segment to
Yann 0:f30e2135b0db 1199 * @param local_port the local TCP port to send the segment from
Yann 0:f30e2135b0db 1200 * @param remote_port the remote TCP port to send the segment to
Yann 0:f30e2135b0db 1201 */
Yann 0:f30e2135b0db 1202 void
Yann 0:f30e2135b0db 1203 tcp_rst(u32_t seqno, u32_t ackno,
Yann 0:f30e2135b0db 1204 ip_addr_t *local_ip, ip_addr_t *remote_ip,
Yann 0:f30e2135b0db 1205 u16_t local_port, u16_t remote_port)
Yann 0:f30e2135b0db 1206 {
Yann 0:f30e2135b0db 1207 struct pbuf *p;
Yann 0:f30e2135b0db 1208 struct tcp_hdr *tcphdr;
Yann 0:f30e2135b0db 1209 p = pbuf_alloc(PBUF_IP, TCP_HLEN, PBUF_RAM);
Yann 0:f30e2135b0db 1210 if (p == NULL) {
Yann 0:f30e2135b0db 1211 LWIP_DEBUGF(TCP_DEBUG, ("tcp_rst: could not allocate memory for pbuf\n"));
Yann 0:f30e2135b0db 1212 return;
Yann 0:f30e2135b0db 1213 }
Yann 0:f30e2135b0db 1214 LWIP_ASSERT("check that first pbuf can hold struct tcp_hdr",
Yann 0:f30e2135b0db 1215 (p->len >= sizeof(struct tcp_hdr)));
Yann 0:f30e2135b0db 1216
Yann 0:f30e2135b0db 1217 tcphdr = (struct tcp_hdr *)p->payload;
Yann 0:f30e2135b0db 1218 tcphdr->src = htons(local_port);
Yann 0:f30e2135b0db 1219 tcphdr->dest = htons(remote_port);
Yann 0:f30e2135b0db 1220 tcphdr->seqno = htonl(seqno);
Yann 0:f30e2135b0db 1221 tcphdr->ackno = htonl(ackno);
Yann 0:f30e2135b0db 1222 TCPH_HDRLEN_FLAGS_SET(tcphdr, TCP_HLEN/4, TCP_RST | TCP_ACK);
Yann 0:f30e2135b0db 1223 tcphdr->wnd = PP_HTONS(TCP_WND);
Yann 0:f30e2135b0db 1224 tcphdr->chksum = 0;
Yann 0:f30e2135b0db 1225 tcphdr->urgp = 0;
Yann 0:f30e2135b0db 1226
Yann 0:f30e2135b0db 1227 #if CHECKSUM_GEN_TCP
Yann 0:f30e2135b0db 1228 tcphdr->chksum = inet_chksum_pseudo(p, local_ip, remote_ip,
Yann 0:f30e2135b0db 1229 IP_PROTO_TCP, p->tot_len);
Yann 0:f30e2135b0db 1230 #endif
Yann 0:f30e2135b0db 1231 TCP_STATS_INC(tcp.xmit);
Yann 0:f30e2135b0db 1232 snmp_inc_tcpoutrsts();
Yann 0:f30e2135b0db 1233 /* Send output with hardcoded TTL since we have no access to the pcb */
Yann 0:f30e2135b0db 1234 ip_output(p, local_ip, remote_ip, TCP_TTL, 0, IP_PROTO_TCP);
Yann 0:f30e2135b0db 1235 pbuf_free(p);
Yann 0:f30e2135b0db 1236 LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_rst: seqno %"U32_F" ackno %"U32_F".\n", seqno, ackno));
Yann 0:f30e2135b0db 1237 }
Yann 0:f30e2135b0db 1238
Yann 0:f30e2135b0db 1239 /**
Yann 0:f30e2135b0db 1240 * Requeue all unacked segments for retransmission
Yann 0:f30e2135b0db 1241 *
Yann 0:f30e2135b0db 1242 * Called by tcp_slowtmr() for slow retransmission.
Yann 0:f30e2135b0db 1243 *
Yann 0:f30e2135b0db 1244 * @param pcb the tcp_pcb for which to re-enqueue all unacked segments
Yann 0:f30e2135b0db 1245 */
Yann 0:f30e2135b0db 1246 void
Yann 0:f30e2135b0db 1247 tcp_rexmit_rto(struct tcp_pcb *pcb)
Yann 0:f30e2135b0db 1248 {
Yann 0:f30e2135b0db 1249 struct tcp_seg *seg;
Yann 0:f30e2135b0db 1250
Yann 0:f30e2135b0db 1251 if (pcb->unacked == NULL) {
Yann 0:f30e2135b0db 1252 return;
Yann 0:f30e2135b0db 1253 }
Yann 0:f30e2135b0db 1254
Yann 0:f30e2135b0db 1255 /* Move all unacked segments to the head of the unsent queue */
Yann 0:f30e2135b0db 1256 for (seg = pcb->unacked; seg->next != NULL; seg = seg->next);
Yann 0:f30e2135b0db 1257 /* concatenate unsent queue after unacked queue */
Yann 0:f30e2135b0db 1258 seg->next = pcb->unsent;
Yann 0:f30e2135b0db 1259 /* unsent queue is the concatenated queue (of unacked, unsent) */
Yann 0:f30e2135b0db 1260 pcb->unsent = pcb->unacked;
Yann 0:f30e2135b0db 1261 /* unacked queue is now empty */
Yann 0:f30e2135b0db 1262 pcb->unacked = NULL;
Yann 0:f30e2135b0db 1263
Yann 0:f30e2135b0db 1264 /* increment number of retransmissions */
Yann 0:f30e2135b0db 1265 ++pcb->nrtx;
Yann 0:f30e2135b0db 1266
Yann 0:f30e2135b0db 1267 /* Don't take any RTT measurements after retransmitting. */
Yann 0:f30e2135b0db 1268 pcb->rttest = 0;
Yann 0:f30e2135b0db 1269
Yann 0:f30e2135b0db 1270 /* Do the actual retransmission */
Yann 0:f30e2135b0db 1271 tcp_output(pcb);
Yann 0:f30e2135b0db 1272 }
Yann 0:f30e2135b0db 1273
Yann 0:f30e2135b0db 1274 /**
Yann 0:f30e2135b0db 1275 * Requeue the first unacked segment for retransmission
Yann 0:f30e2135b0db 1276 *
Yann 0:f30e2135b0db 1277 * Called by tcp_receive() for fast retramsmit.
Yann 0:f30e2135b0db 1278 *
Yann 0:f30e2135b0db 1279 * @param pcb the tcp_pcb for which to retransmit the first unacked segment
Yann 0:f30e2135b0db 1280 */
Yann 0:f30e2135b0db 1281 void
Yann 0:f30e2135b0db 1282 tcp_rexmit(struct tcp_pcb *pcb)
Yann 0:f30e2135b0db 1283 {
Yann 0:f30e2135b0db 1284 struct tcp_seg *seg;
Yann 0:f30e2135b0db 1285 struct tcp_seg **cur_seg;
Yann 0:f30e2135b0db 1286
Yann 0:f30e2135b0db 1287 if (pcb->unacked == NULL) {
Yann 0:f30e2135b0db 1288 return;
Yann 0:f30e2135b0db 1289 }
Yann 0:f30e2135b0db 1290
Yann 0:f30e2135b0db 1291 /* Move the first unacked segment to the unsent queue */
Yann 0:f30e2135b0db 1292 /* Keep the unsent queue sorted. */
Yann 0:f30e2135b0db 1293 seg = pcb->unacked;
Yann 0:f30e2135b0db 1294 pcb->unacked = seg->next;
Yann 0:f30e2135b0db 1295
Yann 0:f30e2135b0db 1296 cur_seg = &(pcb->unsent);
Yann 0:f30e2135b0db 1297 while (*cur_seg &&
Yann 0:f30e2135b0db 1298 TCP_SEQ_LT(ntohl((*cur_seg)->tcphdr->seqno), ntohl(seg->tcphdr->seqno))) {
Yann 0:f30e2135b0db 1299 cur_seg = &((*cur_seg)->next );
Yann 0:f30e2135b0db 1300 }
Yann 0:f30e2135b0db 1301 seg->next = *cur_seg;
Yann 0:f30e2135b0db 1302 *cur_seg = seg;
Yann 0:f30e2135b0db 1303
Yann 0:f30e2135b0db 1304 ++pcb->nrtx;
Yann 0:f30e2135b0db 1305
Yann 0:f30e2135b0db 1306 /* Don't take any rtt measurements after retransmitting. */
Yann 0:f30e2135b0db 1307 pcb->rttest = 0;
Yann 0:f30e2135b0db 1308
Yann 0:f30e2135b0db 1309 /* Do the actual retransmission. */
Yann 0:f30e2135b0db 1310 snmp_inc_tcpretranssegs();
Yann 0:f30e2135b0db 1311 /* No need to call tcp_output: we are always called from tcp_input()
Yann 0:f30e2135b0db 1312 and thus tcp_output directly returns. */
Yann 0:f30e2135b0db 1313 }
Yann 0:f30e2135b0db 1314
Yann 0:f30e2135b0db 1315
Yann 0:f30e2135b0db 1316 /**
Yann 0:f30e2135b0db 1317 * Handle retransmission after three dupacks received
Yann 0:f30e2135b0db 1318 *
Yann 0:f30e2135b0db 1319 * @param pcb the tcp_pcb for which to retransmit the first unacked segment
Yann 0:f30e2135b0db 1320 */
Yann 0:f30e2135b0db 1321 void
Yann 0:f30e2135b0db 1322 tcp_rexmit_fast(struct tcp_pcb *pcb)
Yann 0:f30e2135b0db 1323 {
Yann 0:f30e2135b0db 1324 if (pcb->unacked != NULL && !(pcb->flags & TF_INFR)) {
Yann 0:f30e2135b0db 1325 /* This is fast retransmit. Retransmit the first unacked segment. */
Yann 0:f30e2135b0db 1326 LWIP_DEBUGF(TCP_FR_DEBUG,
Yann 0:f30e2135b0db 1327 ("tcp_receive: dupacks %"U16_F" (%"U32_F
Yann 0:f30e2135b0db 1328 "), fast retransmit %"U32_F"\n",
Yann 0:f30e2135b0db 1329 (u16_t)pcb->dupacks, pcb->lastack,
Yann 0:f30e2135b0db 1330 ntohl(pcb->unacked->tcphdr->seqno)));
Yann 0:f30e2135b0db 1331 tcp_rexmit(pcb);
Yann 0:f30e2135b0db 1332
Yann 0:f30e2135b0db 1333 /* Set ssthresh to half of the minimum of the current
Yann 0:f30e2135b0db 1334 * cwnd and the advertised window */
Yann 0:f30e2135b0db 1335 if (pcb->cwnd > pcb->snd_wnd) {
Yann 0:f30e2135b0db 1336 pcb->ssthresh = pcb->snd_wnd / 2;
Yann 0:f30e2135b0db 1337 } else {
Yann 0:f30e2135b0db 1338 pcb->ssthresh = pcb->cwnd / 2;
Yann 0:f30e2135b0db 1339 }
Yann 0:f30e2135b0db 1340
Yann 0:f30e2135b0db 1341 /* The minimum value for ssthresh should be 2 MSS */
Yann 0:f30e2135b0db 1342 if (pcb->ssthresh < 2*pcb->mss) {
Yann 0:f30e2135b0db 1343 LWIP_DEBUGF(TCP_FR_DEBUG,
Yann 0:f30e2135b0db 1344 ("tcp_receive: The minimum value for ssthresh %"U16_F
Yann 0:f30e2135b0db 1345 " should be min 2 mss %"U16_F"...\n",
Yann 0:f30e2135b0db 1346 pcb->ssthresh, 2*pcb->mss));
Yann 0:f30e2135b0db 1347 pcb->ssthresh = 2*pcb->mss;
Yann 0:f30e2135b0db 1348 }
Yann 0:f30e2135b0db 1349
Yann 0:f30e2135b0db 1350 pcb->cwnd = pcb->ssthresh + 3 * pcb->mss;
Yann 0:f30e2135b0db 1351 pcb->flags |= TF_INFR;
Yann 0:f30e2135b0db 1352 }
Yann 0:f30e2135b0db 1353 }
Yann 0:f30e2135b0db 1354
Yann 0:f30e2135b0db 1355
Yann 0:f30e2135b0db 1356 /**
Yann 0:f30e2135b0db 1357 * Send keepalive packets to keep a connection active although
Yann 0:f30e2135b0db 1358 * no data is sent over it.
Yann 0:f30e2135b0db 1359 *
Yann 0:f30e2135b0db 1360 * Called by tcp_slowtmr()
Yann 0:f30e2135b0db 1361 *
Yann 0:f30e2135b0db 1362 * @param pcb the tcp_pcb for which to send a keepalive packet
Yann 0:f30e2135b0db 1363 */
Yann 0:f30e2135b0db 1364 void
Yann 0:f30e2135b0db 1365 tcp_keepalive(struct tcp_pcb *pcb)
Yann 0:f30e2135b0db 1366 {
Yann 0:f30e2135b0db 1367 struct pbuf *p;
Yann 0:f30e2135b0db 1368 struct tcp_hdr *tcphdr;
Yann 0:f30e2135b0db 1369
Yann 0:f30e2135b0db 1370 LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: sending KEEPALIVE probe to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
Yann 0:f30e2135b0db 1371 ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip),
Yann 0:f30e2135b0db 1372 ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip)));
Yann 0:f30e2135b0db 1373
Yann 0:f30e2135b0db 1374 LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: tcp_ticks %"U32_F" pcb->tmr %"U32_F" pcb->keep_cnt_sent %"U16_F"\n",
Yann 0:f30e2135b0db 1375 tcp_ticks, pcb->tmr, pcb->keep_cnt_sent));
Yann 0:f30e2135b0db 1376
Yann 0:f30e2135b0db 1377 p = tcp_output_alloc_header(pcb, 0, 0, htonl(pcb->snd_nxt - 1));
Yann 0:f30e2135b0db 1378 if(p == NULL) {
Yann 0:f30e2135b0db 1379 LWIP_DEBUGF(TCP_DEBUG,
Yann 0:f30e2135b0db 1380 ("tcp_keepalive: could not allocate memory for pbuf\n"));
Yann 0:f30e2135b0db 1381 return;
Yann 0:f30e2135b0db 1382 }
Yann 0:f30e2135b0db 1383 tcphdr = (struct tcp_hdr *)p->payload;
Yann 0:f30e2135b0db 1384
Yann 0:f30e2135b0db 1385 #if CHECKSUM_GEN_TCP
Yann 0:f30e2135b0db 1386 tcphdr->chksum = inet_chksum_pseudo(p, &pcb->local_ip, &pcb->remote_ip,
Yann 0:f30e2135b0db 1387 IP_PROTO_TCP, p->tot_len);
Yann 0:f30e2135b0db 1388 #endif
Yann 0:f30e2135b0db 1389 TCP_STATS_INC(tcp.xmit);
Yann 0:f30e2135b0db 1390
Yann 0:f30e2135b0db 1391 /* Send output to IP */
Yann 0:f30e2135b0db 1392 #if LWIP_NETIF_HWADDRHINT
Yann 0:f30e2135b0db 1393 ip_output_hinted(p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, 0, IP_PROTO_TCP,
Yann 0:f30e2135b0db 1394 &(pcb->addr_hint));
Yann 0:f30e2135b0db 1395 #else /* LWIP_NETIF_HWADDRHINT*/
Yann 0:f30e2135b0db 1396 ip_output(p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, 0, IP_PROTO_TCP);
Yann 0:f30e2135b0db 1397 #endif /* LWIP_NETIF_HWADDRHINT*/
Yann 0:f30e2135b0db 1398
Yann 0:f30e2135b0db 1399 pbuf_free(p);
Yann 0:f30e2135b0db 1400
Yann 0:f30e2135b0db 1401 LWIP_DEBUGF(TCP_DEBUG, ("tcp_keepalive: seqno %"U32_F" ackno %"U32_F".\n",
Yann 0:f30e2135b0db 1402 pcb->snd_nxt - 1, pcb->rcv_nxt));
Yann 0:f30e2135b0db 1403 }
Yann 0:f30e2135b0db 1404
Yann 0:f30e2135b0db 1405
Yann 0:f30e2135b0db 1406 /**
Yann 0:f30e2135b0db 1407 * Send persist timer zero-window probes to keep a connection active
Yann 0:f30e2135b0db 1408 * when a window update is lost.
Yann 0:f30e2135b0db 1409 *
Yann 0:f30e2135b0db 1410 * Called by tcp_slowtmr()
Yann 0:f30e2135b0db 1411 *
Yann 0:f30e2135b0db 1412 * @param pcb the tcp_pcb for which to send a zero-window probe packet
Yann 0:f30e2135b0db 1413 */
Yann 0:f30e2135b0db 1414 void
Yann 0:f30e2135b0db 1415 tcp_zero_window_probe(struct tcp_pcb *pcb)
Yann 0:f30e2135b0db 1416 {
Yann 0:f30e2135b0db 1417 struct pbuf *p;
Yann 0:f30e2135b0db 1418 struct tcp_hdr *tcphdr;
Yann 0:f30e2135b0db 1419 struct tcp_seg *seg;
Yann 0:f30e2135b0db 1420 u16_t len;
Yann 0:f30e2135b0db 1421 u8_t is_fin;
Yann 0:f30e2135b0db 1422
Yann 0:f30e2135b0db 1423 LWIP_DEBUGF(TCP_DEBUG,
Yann 0:f30e2135b0db 1424 ("tcp_zero_window_probe: sending ZERO WINDOW probe to %"
Yann 0:f30e2135b0db 1425 U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
Yann 0:f30e2135b0db 1426 ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip),
Yann 0:f30e2135b0db 1427 ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip)));
Yann 0:f30e2135b0db 1428
Yann 0:f30e2135b0db 1429 LWIP_DEBUGF(TCP_DEBUG,
Yann 0:f30e2135b0db 1430 ("tcp_zero_window_probe: tcp_ticks %"U32_F
Yann 0:f30e2135b0db 1431 " pcb->tmr %"U32_F" pcb->keep_cnt_sent %"U16_F"\n",
Yann 0:f30e2135b0db 1432 tcp_ticks, pcb->tmr, pcb->keep_cnt_sent));
Yann 0:f30e2135b0db 1433
Yann 0:f30e2135b0db 1434 seg = pcb->unacked;
Yann 0:f30e2135b0db 1435
Yann 0:f30e2135b0db 1436 if(seg == NULL) {
Yann 0:f30e2135b0db 1437 seg = pcb->unsent;
Yann 0:f30e2135b0db 1438 }
Yann 0:f30e2135b0db 1439 if(seg == NULL) {
Yann 0:f30e2135b0db 1440 return;
Yann 0:f30e2135b0db 1441 }
Yann 0:f30e2135b0db 1442
Yann 0:f30e2135b0db 1443 is_fin = ((TCPH_FLAGS(seg->tcphdr) & TCP_FIN) != 0) && (seg->len == 0);
Yann 0:f30e2135b0db 1444 /* we want to send one seqno: either FIN or data (no options) */
Yann 0:f30e2135b0db 1445 len = is_fin ? 0 : 1;
Yann 0:f30e2135b0db 1446
Yann 0:f30e2135b0db 1447 p = tcp_output_alloc_header(pcb, 0, len, seg->tcphdr->seqno);
Yann 0:f30e2135b0db 1448 if(p == NULL) {
Yann 0:f30e2135b0db 1449 LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: no memory for pbuf\n"));
Yann 0:f30e2135b0db 1450 return;
Yann 0:f30e2135b0db 1451 }
Yann 0:f30e2135b0db 1452 tcphdr = (struct tcp_hdr *)p->payload;
Yann 0:f30e2135b0db 1453
Yann 0:f30e2135b0db 1454 if (is_fin) {
Yann 0:f30e2135b0db 1455 /* FIN segment, no data */
Yann 0:f30e2135b0db 1456 TCPH_FLAGS_SET(tcphdr, TCP_ACK | TCP_FIN);
Yann 0:f30e2135b0db 1457 } else {
Yann 0:f30e2135b0db 1458 /* Data segment, copy in one byte from the head of the unacked queue */
Yann 0:f30e2135b0db 1459 *((char *)p->payload + TCP_HLEN) = *(char *)seg->dataptr;
Yann 0:f30e2135b0db 1460 }
Yann 0:f30e2135b0db 1461
Yann 0:f30e2135b0db 1462 #if CHECKSUM_GEN_TCP
Yann 0:f30e2135b0db 1463 tcphdr->chksum = inet_chksum_pseudo(p, &pcb->local_ip, &pcb->remote_ip,
Yann 0:f30e2135b0db 1464 IP_PROTO_TCP, p->tot_len);
Yann 0:f30e2135b0db 1465 #endif
Yann 0:f30e2135b0db 1466 TCP_STATS_INC(tcp.xmit);
Yann 0:f30e2135b0db 1467
Yann 0:f30e2135b0db 1468 /* Send output to IP */
Yann 0:f30e2135b0db 1469 #if LWIP_NETIF_HWADDRHINT
Yann 0:f30e2135b0db 1470 ip_output_hinted(p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, 0, IP_PROTO_TCP,
Yann 0:f30e2135b0db 1471 &(pcb->addr_hint));
Yann 0:f30e2135b0db 1472 #else /* LWIP_NETIF_HWADDRHINT*/
Yann 0:f30e2135b0db 1473 ip_output(p, &pcb->local_ip, &pcb->remote_ip, pcb->ttl, 0, IP_PROTO_TCP);
Yann 0:f30e2135b0db 1474 #endif /* LWIP_NETIF_HWADDRHINT*/
Yann 0:f30e2135b0db 1475
Yann 0:f30e2135b0db 1476 pbuf_free(p);
Yann 0:f30e2135b0db 1477
Yann 0:f30e2135b0db 1478 LWIP_DEBUGF(TCP_DEBUG, ("tcp_zero_window_probe: seqno %"U32_F
Yann 0:f30e2135b0db 1479 " ackno %"U32_F".\n",
Yann 0:f30e2135b0db 1480 pcb->snd_nxt - 1, pcb->rcv_nxt));
Yann 0:f30e2135b0db 1481 }
Yann 0:f30e2135b0db 1482 #endif /* LWIP_TCP */