/*
* Copyright (c) 2001, 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. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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>
*
* $Id$
*/
/*-----------------------------------------------------------------------------------*/
/* tcp_output.c
*
* The output functions of TCP.
*
*/
/*-----------------------------------------------------------------------------------*/
#include <ubixos/types.h>
#include "net/debug.h"
#include "net/def.h"
#include "net/opt.h"
#include "net/arch/lib.h"
#include "net/mem.h"
#include "net/memp.h"
#include "net/sys.h"
#include "net/netif.h"
#include "net/ipv4/inet.h"
#include "net/tcp.h"
#include "net/stats.h"
#define MIN(x,y) (x) < (y)? (x): (y)
/* Forward declarations.*/
static void tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb);
/*-----------------------------------------------------------------------------------*/
err_t
tcp_send_ctrl(struct tcp_pcb *pcb, uInt8 flags)
{
return tcp_enqueue(pcb, NULL, 0, flags, 1, NULL, 0);
}
/*-----------------------------------------------------------------------------------*/
err_t
tcp_write(struct tcp_pcb *pcb, const void *arg, uInt16 len, uInt8 copy)
{
if(pcb->state == SYN_SENT ||
pcb->state == SYN_RCVD ||
pcb->state == ESTABLISHED ||
pcb->state == CLOSE_WAIT) {
if(len > 0) {
return tcp_enqueue(pcb, (void *)arg, len, 0, copy, NULL, 0);
}
return ERR_OK;
} else {
return ERR_CONN;
}
}
/*-----------------------------------------------------------------------------------*/
err_t
tcp_enqueue(struct tcp_pcb *pcb, void *arg, uInt16 len,
uInt8 flags, uInt8 copy,
uInt8 *optdata, uInt8 optlen)
{
struct pbuf *p;
struct tcp_seg *seg, *useg, *queue;
uInt32 left, seqno;
uInt16 seglen;
void *ptr;
uInt8 queuelen;
left = len;
ptr = arg;
if(len > pcb->snd_buf) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: too much data %d\n", len));
return ERR_MEM;
}
seqno = pcb->snd_lbb;
queue = NULL;
DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue: %d\n", pcb->snd_queuelen));
queuelen = pcb->snd_queuelen;
if(queuelen >= TCP_SND_QUEUELEN) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: too long queue %d (max %d)\n", queuelen, TCP_SND_QUEUELEN));
goto memerr;
}
#ifdef LWIP_DEBUG
if(pcb->snd_queuelen != 0) {
ASSERT("tcp_enqueue: valid queue length", pcb->unacked != NULL ||
pcb->unsent != NULL);
}
#endif /* LWIP_DEBUG */
seg = NULL;
seglen = 0;
while(queue == NULL || left > 0) {
seglen = left > pcb->mss? pcb->mss: left;
/* allocate memory for tcp_seg, and fill in fields */
seg = memp_malloc(MEMP_TCP_SEG);
if(seg == NULL) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: could not allocate memory for tcp_seg\n"));
goto memerr;
}
seg->next = NULL;
seg->p = NULL;
if(queue == NULL) {
queue = seg;
} else {
for(useg = queue; useg->next != NULL; useg = useg->next);
useg->next = seg;
}
/* If copy is set, memory should be allocated
and data copied into pbuf, otherwise data comes from
ROM or other static memory, and need not be copied. If
optdata is != NULL, we have options instead of data. */
if(optdata != NULL) {
if((seg->p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) {
goto memerr;
}
++queuelen;
seg->dataptr = seg->p->payload;
} else if(copy) {
if((seg->p = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_RAM)) == NULL) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: could not allocate memory for pbuf copy\n"));
goto memerr;
}
++queuelen;
if(arg != NULL) {
bcopy(ptr, seg->p->payload, seglen);
}
seg->dataptr = seg->p->payload;
} else {
/* Do not copy the data. */
if((p = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_ROM)) == NULL) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: could not allocate memory for pbuf non-copy\n"));
goto memerr;
}
++queuelen;
p->payload = ptr;
seg->dataptr = ptr;
if((seg->p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_RAM)) == NULL) {
pbuf_free(p);
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: could not allocate memory for header pbuf\n"));
goto memerr;
}
++queuelen;
pbuf_chain(seg->p, p);
}
if(queuelen > TCP_SND_QUEUELEN) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: queue too long %d (%d)\n", queuelen, TCP_SND_QUEUELEN));
goto memerr;
}
seg->len = seglen;
/* if((flags & TCP_SYN) || (flags & TCP_FIN)) {
++seg->len;
}*/
/* build TCP header */
if(pbuf_header(seg->p, TCP_HLEN)) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: no room for TCP header in pbuf.\n"));
#ifdef TCP_STATS
++stats.tcp.err;
#endif /* TCP_STATS */
goto memerr;
}
seg->tcphdr = seg->p->payload;
seg->tcphdr->src = htons(pcb->local_port);
seg->tcphdr->dest = htons(pcb->remote_port);
seg->tcphdr->seqno = htonl(seqno);
seg->tcphdr->urgp = 0;
TCPH_FLAGS_SET(seg->tcphdr, flags);
/* don't fill in tcphdr->ackno and tcphdr->wnd until later */
if(optdata == NULL) {
TCPH_OFFSET_SET(seg->tcphdr, 5 << 4);
} else {
TCPH_OFFSET_SET(seg->tcphdr, (5 + optlen / 4) << 4);
/* Copy options into data portion of segment.
Options can thus only be sent in non data carrying
segments such as SYN|ACK. */
bcopy(optdata, seg->dataptr, optlen);
}
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: queueing %lu:%lu (0x%x)\n",
ntohl(seg->tcphdr->seqno),
ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg),
flags));
left -= seglen;
seqno += seglen;
ptr = (void *)((char *)ptr + seglen);
}
/* Go to the last segment on the ->unsent queue. */
if(pcb->unsent == NULL) {
useg = NULL;
} else {
for(useg = pcb->unsent; useg->next != NULL; useg = useg->next);
}
/* If there is room in the last pbuf on the unsent queue,
chain the first pbuf on the queue together with that. */
if(useg != NULL &&
TCP_TCPLEN(useg) != 0 &&
!(TCPH_FLAGS(useg->tcphdr) & (TCP_SYN | TCP_FIN)) &&
!(flags & (TCP_SYN | TCP_FIN)) &&
useg->len + queue->len <= pcb->mss) {
/* Remove TCP header from first segment. */
pbuf_header(queue->p, -TCP_HLEN);
pbuf_chain(useg->p, queue->p);
useg->len += queue->len;
useg->next = queue->next;
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: chaining, new len %u\n", useg->len));
if(seg == queue) {
seg = NULL;
}
memp_free(MEMP_TCP_SEG, queue);
} else {
if(useg == NULL) {
pcb->unsent = queue;
} else {
useg->next = queue;
}
}
if((flags & TCP_SYN) || (flags & TCP_FIN)) {
++len;
}
pcb->snd_lbb += len;
pcb->snd_buf -= len;
pcb->snd_queuelen = queuelen;
DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue: %d (after enqueued)\n", pcb->snd_queuelen));
#ifdef LWIP_DEBUG
if(pcb->snd_queuelen != 0) {
ASSERT("tcp_enqueue: valid queue length", pcb->unacked != NULL ||
pcb->unsent != NULL);
}
#endif /* LWIP_DEBUG */
/* Set the PSH flag in the last segment that we enqueued, but only
if the segment has data (indicated by seglen > 0). */
if(seg != NULL && seglen > 0 && seg->tcphdr != NULL) {
TCPH_FLAGS_SET(seg->tcphdr, TCPH_FLAGS(seg->tcphdr) | TCP_PSH);
}
return ERR_OK;
memerr:
#ifdef TCP_STATS
++stats.tcp.memerr;
#endif /* TCP_STATS */
if(queue != NULL) {
tcp_segs_free(queue);
}
#ifdef LWIP_DEBUG
if(pcb->snd_queuelen != 0) {
ASSERT("tcp_enqueue: valid queue length", pcb->unacked != NULL ||
pcb->unsent != NULL);
}
#endif /* LWIP_DEBUG */
DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue: %d (with mem err)\n", pcb->snd_queuelen));
return ERR_MEM;
}
/*-----------------------------------------------------------------------------------*/
/* find out what we can send and send it */
err_t
tcp_output(struct tcp_pcb *pcb)
{
struct pbuf *p;
struct tcp_hdr *tcphdr;
struct tcp_seg *seg, *useg;
uInt32 wnd;
#if TCP_CWND_DEBUG
int i = 0;
#endif /* TCP_CWND_DEBUG */
wnd = MIN(pcb->snd_wnd, pcb->cwnd);
seg = pcb->unsent;
if(pcb->flags & TF_ACK_NOW) {
/* If no segments are enqueued but we should send an ACK, we
construct the ACK and send it. */
pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_RAM);
if(p == NULL) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: (ACK) could not allocate pbuf\n"));
return ERR_BUF;
}
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: sending ACK for %lu\n", pcb->rcv_nxt));
if(pbuf_header(p, TCP_HLEN)) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: (ACK) no room for TCP header in pbuf.\n"));
#ifdef TCP_STATS
++stats.tcp.err;
#endif /* TCP_STATS */
pbuf_free(p);
return ERR_BUF;
}
tcphdr = p->payload;
tcphdr->src = htons(pcb->local_port);
tcphdr->dest = htons(pcb->remote_port);
tcphdr->seqno = htonl(pcb->snd_nxt);
tcphdr->ackno = htonl(pcb->rcv_nxt);
TCPH_FLAGS_SET(tcphdr, TCP_ACK);
tcphdr->wnd = htons(pcb->rcv_wnd);
tcphdr->urgp = 0;
TCPH_OFFSET_SET(tcphdr, 5 << 4);
tcphdr->chksum = 0;
tcphdr->chksum = inet_chksum_pseudo(p, &(pcb->local_ip), &(pcb->remote_ip),
IP_PROTO_TCP, p->tot_len);
ip_output(p, &(pcb->local_ip), &(pcb->remote_ip), TCP_TTL,
IP_PROTO_TCP);
pbuf_free(p);
return ERR_OK;
}
#if TCP_OUTPUT_DEBUG
if(seg == NULL) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output: nothing to send\n"));
}
#endif /* TCP_OUTPUT_DEBUG */
#if TCP_CWND_DEBUG
if(seg == NULL) {
DEBUGF(TCP_CWND_DEBUG, ("tcp_output: snd_wnd %lu, cwnd %lu, wnd %lu, seg == NULL, ack %lu\n",
pcb->snd_wnd, pcb->cwnd, wnd,
pcb->lastack));
} else {
DEBUGF(TCP_CWND_DEBUG, ("tcp_output: snd_wnd %lu, cwnd %lu, wnd %lu, effwnd %lu, seq %lu, ack %lu\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 */
while(seg != NULL &&
ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len <= wnd) {
pcb->rtime = 0;
#if TCP_CWND_DEBUG
DEBUGF(TCP_CWND_DEBUG, ("tcp_output: snd_wnd %lu, cwnd %lu, wnd %lu, effwnd %lu, seq %lu, ack %lu, i%d\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_FLAGS_SET(seg->tcphdr, TCPH_FLAGS(seg->tcphdr) | TCP_ACK);
pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
}
tcp_output_segment(seg, pcb);
pcb->snd_nxt = ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg);
if(TCP_SEQ_LT(pcb->snd_max, pcb->snd_nxt)) {
pcb->snd_max = pcb->snd_nxt;
}
/* put segment on unacknowledged list if length > 0 */
if(TCP_TCPLEN(seg) > 0) {
seg->next = NULL;
if(pcb->unacked == NULL) {
pcb->unacked = seg;
} else {
for(useg = pcb->unacked; useg->next != NULL; useg = useg->next);
useg->next = seg;
}
/* seg->rtime = 0;*/
} else {
tcp_seg_free(seg);
}
seg = pcb->unsent;
}
return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
static void
tcp_output_segment(struct tcp_seg *seg, struct tcp_pcb *pcb)
{
uInt16 len, tot_len;
struct netif *netif;
/* The TCP header has already been constructed, but the ackno and
wnd fields remain. */
seg->tcphdr->ackno = htonl(pcb->rcv_nxt);
/* silly window avoidance */
if(pcb->rcv_wnd < pcb->mss) {
seg->tcphdr->wnd = 0;
} else {
seg->tcphdr->wnd = htons(pcb->rcv_wnd);
}
/* If we don't have a local IP address, we get one by
calling ip_route(). */
if(ip_addr_isany(&(pcb->local_ip))) {
netif = ip_route(&(pcb->remote_ip));
if(netif == NULL) {
return;
}
ip_addr_set(&(pcb->local_ip), &(netif->ip_addr));
}
pcb->rtime = 0;
if(pcb->rttest == 0) {
pcb->rttest = tcp_ticks;
pcb->rtseq = ntohl(seg->tcphdr->seqno);
DEBUGF(TCP_RTO_DEBUG, ("tcp_output_segment: rtseq %lu\n", pcb->rtseq));
}
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_output_segment: %lu:%lu\n",
htonl(seg->tcphdr->seqno), htonl(seg->tcphdr->seqno) +
seg->len));
seg->tcphdr->chksum = 0;
seg->tcphdr->chksum = inet_chksum_pseudo(seg->p,
&(pcb->local_ip),
&(pcb->remote_ip),
IP_PROTO_TCP, seg->p->tot_len);
#ifdef TCP_STATS
++stats.tcp.xmit;
#endif /* TCP_STATS */
len = seg->p->len;
tot_len = seg->p->tot_len;
ip_output(seg->p, &(pcb->local_ip), &(pcb->remote_ip), TCP_TTL,
IP_PROTO_TCP);
seg->p->len = len;
seg->p->tot_len = tot_len;
seg->p->payload = seg->tcphdr;
}
/*-----------------------------------------------------------------------------------*/
void
tcp_rexmit_seg(struct tcp_pcb *pcb, struct tcp_seg *seg)
{
uInt32 wnd;
uInt16 len, tot_len;
struct netif *netif;
DEBUGF(TCP_REXMIT_DEBUG, ("tcp_rexmit_seg: skickar %ld:%ld\n",
ntohl(seg->tcphdr->seqno),
ntohl(seg->tcphdr->seqno) + TCP_TCPLEN(seg)));
wnd = MIN(pcb->snd_wnd, pcb->cwnd);
if(ntohl(seg->tcphdr->seqno) - pcb->lastack + seg->len <= wnd) {
/* Count the number of retranmissions. */
++pcb->nrtx;
if((netif = ip_route((struct ip_addr *)&(pcb->remote_ip))) == NULL) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_rexmit_segment: No route to 0x%lx\n", pcb->remote_ip.addr));
#ifdef TCP_STATS
++stats.tcp.rterr;
#endif /* TCP_STATS */
return;
}
seg->tcphdr->ackno = htonl(pcb->rcv_nxt);
seg->tcphdr->wnd = htons(pcb->rcv_wnd);
/* Recalculate checksum. */
seg->tcphdr->chksum = 0;
seg->tcphdr->chksum = inet_chksum_pseudo(seg->p,
&(pcb->local_ip),
&(pcb->remote_ip),
IP_PROTO_TCP, seg->p->tot_len);
len = seg->p->len;
tot_len = seg->p->tot_len;
pbuf_header(seg->p, IP_HLEN);
ip_output_if(seg->p, NULL, IP_HDRINCL, TCP_TTL, IP_PROTO_TCP, netif);
seg->p->len = len;
seg->p->tot_len = tot_len;
seg->p->payload = seg->tcphdr;
#ifdef TCP_STATS
++stats.tcp.xmit;
++stats.tcp.rexmit;
#endif /* TCP_STATS */
pcb->rtime = 0;
/* Don't take any rtt measurements after retransmitting. */
pcb->rttest = 0;
} else {
DEBUGF(TCP_REXMIT_DEBUG, ("tcp_rexmit_seg: no room in window %lu to send %lu (ack %lu)\n",
wnd, ntohl(seg->tcphdr->seqno), pcb->lastack));
}
}
/*-----------------------------------------------------------------------------------*/
void
tcp_rst(uInt32 seqno, uInt32 ackno,
struct ip_addr *local_ip, struct ip_addr *remote_ip,
uInt16 local_port, uInt16 remote_port)
{
struct pbuf *p;
struct tcp_hdr *tcphdr;
p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_RAM);
if(p == NULL) {
#if MEM_RECLAIM
mem_reclaim(sizeof(struct pbuf));
p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_RAM);
#endif /* MEM_RECLAIM */
if(p == NULL) {
DEBUGF(TCP_DEBUG, ("tcp_rst: could not allocate memory for pbuf\n"));
return;
}
}
if(pbuf_header(p, TCP_HLEN)) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_send_data: no room for TCP header in pbuf.\n"));
#ifdef TCP_STATS
++stats.tcp.err;
#endif /* TCP_STATS */
return;
}
tcphdr = p->payload;
tcphdr->src = htons(local_port);
tcphdr->dest = htons(remote_port);
tcphdr->seqno = htonl(seqno);
tcphdr->ackno = htonl(ackno);
TCPH_FLAGS_SET(tcphdr, TCP_RST | TCP_ACK);
tcphdr->wnd = 0;
tcphdr->urgp = 0;
TCPH_OFFSET_SET(tcphdr, 5 << 4);
tcphdr->chksum = 0;
tcphdr->chksum = inet_chksum_pseudo(p, local_ip, remote_ip,
IP_PROTO_TCP, p->tot_len);
#ifdef TCP_STATS
++stats.tcp.xmit;
#endif /* TCP_STATS */
ip_output(p, local_ip, remote_ip, TCP_TTL, IP_PROTO_TCP);
pbuf_free(p);
DEBUGF(TCP_RST_DEBUG, ("tcp_rst: seqno %lu ackno %lu.\n", seqno, ackno));
}
/*-----------------------------------------------------------------------------------*/
