/*
* 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.c
*
* This file contains common functions for the TCP implementation, such as functinos
* for manipulating the data structures and the TCP timer functions. TCP functions
* related to input and output is found in tcp_input.c and tcp_output.c respectively.
*
*/
/*-----------------------------------------------------------------------------------*/
#include <ubixos/types.h>
#include "net/debug.h"
#include "net/def.h"
#include "net/mem.h"
#include "net/memp.h"
#include "net/tcp.h"
/* Incremented every coarse grained timer shot
(typically every 500 ms, determined by TCP_COARSE_TIMEOUT). */
uInt32 tcp_ticks;
const uInt8 tcp_backoff[13] =
{ 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
/* The TCP PCB lists. */
struct tcp_pcb_listen *tcp_listen_pcbs; /* List of all TCP PCBs in LISTEN state. */
struct tcp_pcb *tcp_active_pcbs; /* List of all TCP PCBs that are in a
state in which they accept or send
data. */
struct tcp_pcb *tcp_tw_pcbs; /* List of all TCP PCBs in TIME-WAIT. */
struct tcp_pcb *tcp_tmp_pcb;
#define MIN(x,y) (x) < (y)? (x): (y)
#if MEMP_RECLAIM
static uInt8 tcp_memp_reclaim(void *arg, memp_t type);
#endif
#if MEM_RECLAIM
static mem_size_t tcp_mem_reclaim(void *arg, mem_size_t size);
#endif
static uInt8 tcp_timer;
/*-----------------------------------------------------------------------------------*/
/*
* tcp_init():
*
* Initializes the TCP layer.
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_init(void)
{
/* Clear globals. */
tcp_listen_pcbs = NULL;
tcp_active_pcbs = NULL;
tcp_tw_pcbs = NULL;
tcp_tmp_pcb = NULL;
/* Register memory reclaim function */
#if MEM_RECLAIM
mem_register_reclaim((mem_reclaim_func)tcp_mem_reclaim, NULL);
#endif /* MEM_RECLAIM */
#if MEMP_RECLAIM
memp_register_reclaim(MEMP_PBUF, (memp_reclaim_func)tcp_memp_reclaim, NULL);
memp_register_reclaim(MEMP_TCP_SEG, (memp_reclaim_func)tcp_memp_reclaim, NULL);
memp_register_reclaim(MEMP_TCP_PCB, (memp_reclaim_func)tcp_memp_reclaim, NULL);
#endif /* MEMP_RECLAIM */
/* initialize timer */
tcp_ticks = 0;
tcp_timer = 0;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_tmr():
*
* Called periodically to dispatch TCP timers.
*
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_tmr()
{
++tcp_timer;
if(tcp_timer == 10) {
tcp_timer = 0;
}
if(tcp_timer & 1) {
/* Call tcp_fasttmr() every 200 ms, i.e., every other timer
tcp_tmr() is called. */
tcp_fasttmr();
}
if(tcp_timer == 0 || tcp_timer == 5) {
/* Call tcp_slowtmr() every 500 ms, i.e., every fifth timer
tcp_tmr() is called. */
tcp_slowtmr();
}
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_close():
*
* Closes the connection held by the PCB.
*
*/
/*-----------------------------------------------------------------------------------*/
err_t
tcp_close(struct tcp_pcb *pcb)
{
err_t err;
#if TCP_DEBUG
DEBUGF(TCP_DEBUG, ("tcp_close: closing in state "));
tcp_debug_print_state(pcb->state);
DEBUGF(TCP_DEBUG, ("\n"));
#endif /* TCP_DEBUG */
switch(pcb->state) {
case LISTEN:
err = ERR_OK;
tcp_pcb_remove((struct tcp_pcb **)&tcp_listen_pcbs, pcb);
memp_free(MEMP_TCP_PCB_LISTEN, pcb);
pcb = NULL;
break;
case SYN_SENT:
err = ERR_OK;
tcp_pcb_remove(&tcp_active_pcbs, pcb);
memp_free(MEMP_TCP_PCB, pcb);
pcb = NULL;
break;
case SYN_RCVD:
err = tcp_send_ctrl(pcb, TCP_FIN);
if(err == ERR_OK) {
pcb->state = FIN_WAIT_1;
}
break;
case ESTABLISHED:
err = tcp_send_ctrl(pcb, TCP_FIN);
if(err == ERR_OK) {
pcb->state = FIN_WAIT_1;
}
break;
case CLOSE_WAIT:
err = tcp_send_ctrl(pcb, TCP_FIN);
if(err == ERR_OK) {
pcb->state = LAST_ACK;
}
break;
default:
/* Has already been closed, do nothing. */
err = ERR_OK;
pcb = NULL;
break;
}
if(pcb != NULL && err == ERR_OK) {
err = tcp_output(pcb);
}
return err;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_abort()
*
* Aborts a connection by sending a RST to the remote host and deletes
* the local protocol control block. This is done when a connection is
* killed because of shortage of memory.
*
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_abort(struct tcp_pcb *pcb)
{
uInt32 seqno, ackno;
uInt16 remote_port, local_port;
struct ip_addr remote_ip, local_ip;
void (* errf)(void *arg, err_t err);
void *errf_arg;
/* Figure out on which TCP PCB list we are, and remove us. If we
are in an active state, call the receive function associated with
the PCB with a NULL argument, and send an RST to the remote end. */
if(pcb->state == TIME_WAIT) {
tcp_pcb_remove(&tcp_tw_pcbs, pcb);
memp_free(MEMP_TCP_PCB, pcb);
} else if(pcb->state == LISTEN) {
tcp_pcb_remove((struct tcp_pcb **)&tcp_listen_pcbs, pcb);
memp_free(MEMP_TCP_PCB_LISTEN, pcb);
} else {
seqno = pcb->snd_nxt;
ackno = pcb->rcv_nxt;
ip_addr_set(&local_ip, &(pcb->local_ip));
ip_addr_set(&remote_ip, &(pcb->remote_ip));
local_port = pcb->local_port;
remote_port = pcb->remote_port;
errf = pcb->errf;
errf_arg = pcb->callback_arg;
tcp_pcb_remove(&tcp_active_pcbs, pcb);
memp_free(MEMP_TCP_PCB, pcb);
if(errf != NULL) {
errf(errf_arg, ERR_ABRT);
}
DEBUGF(TCP_RST_DEBUG, ("tcp_abort: sending RST\n"));
tcp_rst(seqno, ackno, &local_ip, &remote_ip, local_port, remote_port);
}
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_bind():
*
* Binds the connection to a local portnumber and IP address. If the
* IP address is not given (i.e., ipaddr == NULL), the IP address of
* the outgoing network interface is used instead.
*
*/
/*-----------------------------------------------------------------------------------*/
err_t
tcp_bind(struct tcp_pcb *pcb, struct ip_addr *ipaddr, uInt16 port)
{
struct tcp_pcb *cpcb;
/* Check if the address already is in use. */
for(cpcb = (struct tcp_pcb *)tcp_listen_pcbs;
cpcb != NULL; cpcb = cpcb->next) {
if(cpcb->local_port == port) {
if(ip_addr_isany(&(cpcb->local_ip)) ||
ip_addr_isany(ipaddr) ||
ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
return ERR_USE;
}
}
}
for(cpcb = tcp_active_pcbs;
cpcb != NULL; cpcb = cpcb->next) {
if(cpcb->local_port == port) {
if(ip_addr_isany(&(cpcb->local_ip)) ||
ip_addr_isany(ipaddr) ||
ip_addr_cmp(&(cpcb->local_ip), ipaddr)) {
return ERR_USE;
}
}
}
if(!ip_addr_isany(ipaddr)) {
pcb->local_ip = *ipaddr;
}
pcb->local_port = port;
DEBUGF(TCP_DEBUG, ("tcp_bind: bind to port %d\n", port));
return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_listen():
*
* Set the state of the connection to be LISTEN, which means that it
* is able to accept incoming connections. The protocol control block
* is reallocated in order to consume less memory. Setting the
* connection to LISTEN is an irreversible process.
*
*/
/*-----------------------------------------------------------------------------------*/
struct tcp_pcb *
tcp_listen(struct tcp_pcb *pcb)
{
pcb->state = LISTEN;
pcb = memp_realloc(MEMP_TCP_PCB, MEMP_TCP_PCB_LISTEN, pcb);
if(pcb == NULL) {
return NULL;
}
TCP_REG((struct tcp_pcb **)&tcp_listen_pcbs, pcb);
return pcb;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_recved():
*
* This function should be called by the application when it has
* processed the data. The purpose is to advertise a larger window
* when the data has been processed.
*
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_recved(struct tcp_pcb *pcb, uInt16 len)
{
pcb->rcv_wnd += len;
if(pcb->rcv_wnd > TCP_WND) {
pcb->rcv_wnd = TCP_WND;
}
if(!(pcb->flags & TF_ACK_DELAY) ||
!(pcb->flags & TF_ACK_NOW)) {
tcp_ack(pcb);
}
DEBUGF(TCP_DEBUG, ("tcp_recved: recveived %d bytes, wnd %u (%u).\n",
len, pcb->rcv_wnd, TCP_WND - pcb->rcv_wnd));
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_new_port():
*
* A nastly hack featuring 'goto' statements that allocates a
* new TCP local port.
*/
/*-----------------------------------------------------------------------------------*/
static uInt16
tcp_new_port(void)
{
struct tcp_pcb *pcb;
static uInt16 port = 4096;
again:
if(++port > 0x7fff) {
port = 4096;
}
for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
if(pcb->local_port == port) {
goto again;
}
}
for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
if(pcb->local_port == port) {
goto again;
}
}
for(pcb = (struct tcp_pcb *)tcp_listen_pcbs; pcb != NULL; pcb = pcb->next) {
if(pcb->local_port == port) {
goto again;
}
}
return port;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_connect():
*
* Connects to another host. The function given as the "connected"
* argument will be called when the connection has been established.
*
*/
/*-----------------------------------------------------------------------------------*/
err_t
tcp_connect(struct tcp_pcb *pcb, struct ip_addr *ipaddr, uInt16 port,
err_t (* connected)(void *arg, struct tcp_pcb *tpcb, err_t err))
{
uInt32 optdata;
err_t ret;
uInt32 iss;
DEBUGF(TCP_DEBUG, ("tcp_connect to port %d\n", port));
if(ipaddr != NULL) {
pcb->remote_ip = *ipaddr;
} else {
return ERR_VAL;
}
pcb->remote_port = port;
if(pcb->local_port == 0) {
pcb->local_port = tcp_new_port();
}
iss = tcp_next_iss();
pcb->rcv_nxt = 0;
pcb->snd_nxt = iss;
pcb->lastack = iss - 1;
pcb->snd_lbb = iss - 1;
pcb->rcv_wnd = TCP_WND;
pcb->snd_wnd = TCP_WND;
pcb->mss = TCP_MSS;
pcb->cwnd = 1;
pcb->ssthresh = pcb->mss * 10;
pcb->state = SYN_SENT;
pcb->connected = connected;
TCP_REG(&tcp_active_pcbs, pcb);
/* Build an MSS option */
optdata = HTONL(((uInt32)2 << 24) |
((uInt32)4 << 16) |
(((uInt32)pcb->mss / 256) << 8) |
(pcb->mss & 255));
ret = tcp_enqueue(pcb, NULL, 0, TCP_SYN, 0, (uInt8 *)&optdata, 4);
if(ret == ERR_OK) {
tcp_output(pcb);
}
return ret;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_slowtmr():
*
* Called every 500 ms and implements the retransmission timer and the timer that
* removes PCBs that have been in TIME-WAIT for enough time. It also increments
* various timers such as the inactivity timer in each PCB.
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_slowtmr(void)
{
static struct tcp_pcb *pcb, *pcb2, *prev;
static struct tcp_seg *seg, *useg;
static uInt32 eff_wnd;
static uInt8 pcb_remove; /* flag if a PCB should be removed */
++tcp_ticks;
/* Steps through all of the active PCBs. */
prev = NULL;
pcb = tcp_active_pcbs;
while(pcb != NULL) {
ASSERT("tcp_timer_coarse: active pcb->state != CLOSED", pcb->state != CLOSED);
ASSERT("tcp_timer_coarse: active pcb->state != LISTEN", pcb->state != LISTEN);
ASSERT("tcp_timer_coarse: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT);
pcb_remove = 0;
if(pcb->state == SYN_SENT && pcb->nrtx == TCP_SYNMAXRTX) {
++pcb_remove;
} else if(pcb->nrtx == TCP_MAXRTX) {
++pcb_remove;
} else {
++pcb->rtime;
seg = pcb->unacked;
if(seg != NULL && pcb->rtime >= pcb->rto) {
DEBUGF(TCP_RTO_DEBUG, ("tcp_timer_coarse: rtime %ld pcb->rto %d\n",
tcp_ticks - pcb->rtime, pcb->rto));
/* Double retransmission time-out unless we are trying to
connect to somebody (i.e., we are in SYN_SENT). */
if(pcb->state != SYN_SENT) {
pcb->rto = ((pcb->sa >> 3) + pcb->sv) << tcp_backoff[pcb->nrtx];
}
/* Move all other unacked segments to the unsent queue. */
if(seg->next != NULL) {
for(useg = seg->next; useg->next != NULL; useg = useg->next);
/* useg now points to the last segment on the unacked queue. */
useg->next = pcb->unsent;
pcb->unsent = seg->next;
seg->next = NULL;
pcb->snd_nxt = ntohl(pcb->unsent->tcphdr->seqno);
}
/* Do the actual retransmission. */
tcp_rexmit_seg(pcb, seg);
/* Reduce congestion window and ssthresh. */
eff_wnd = MIN(pcb->cwnd, pcb->snd_wnd);
pcb->ssthresh = eff_wnd >> 1;
if(pcb->ssthresh < pcb->mss) {
pcb->ssthresh = pcb->mss * 2;
}
pcb->cwnd = pcb->mss;
DEBUGF(TCP_CWND_DEBUG, ("tcp_rexmit_seg: cwnd %u ssthresh %u\n",
pcb->cwnd, pcb->ssthresh));
}
}
/* Check if this PCB has stayed too long in FIN-WAIT-2 */
if(pcb->state == FIN_WAIT_2) {
if((uInt32)(tcp_ticks - pcb->tmr) >
TCP_FIN_WAIT_TIMEOUT / TCP_SLOW_INTERVAL) {
++pcb_remove;
}
}
/* If this PCB has queued out of sequence data, but has been
inactive for too long, will drop the data (it will eventually
be retransmitted). */
#if TCP_QUEUE_OOSEQ
if(pcb->ooseq != NULL &&
(uInt32)tcp_ticks - pcb->tmr >=
pcb->rto * TCP_OOSEQ_TIMEOUT) {
tcp_segs_free(pcb->ooseq);
pcb->ooseq = NULL;
}
#endif /* TCP_QUEUE_OOSEQ */
/* Check if this PCB has stayed too long in SYN-RCVD */
if(pcb->state == SYN_RCVD) {
if((uInt32)(tcp_ticks - pcb->tmr) >
TCP_SYN_RCVD_TIMEOUT / TCP_SLOW_INTERVAL) {
++pcb_remove;
}
}
/* If the PCB should be removed, do it. */
if(pcb_remove) {
tcp_pcb_purge(pcb);
/* Remove PCB from tcp_active_pcbs list. */
if(prev != NULL) {
ASSERT("tcp_timer_coarse: middle tcp != tcp_active_pcbs", pcb != tcp_active_pcbs);
prev->next = pcb->next;
} else {
/* This PCB was the first. */
ASSERT("tcp_timer_coarse: first pcb == tcp_active_pcbs", tcp_active_pcbs == pcb);
tcp_active_pcbs = pcb->next;
}
if(pcb->errf != NULL) {
pcb->errf(pcb->callback_arg, ERR_ABRT);
}
pcb2 = pcb->next;
memp_free(MEMP_TCP_PCB, pcb);
pcb = pcb2;
} else {
/* We check if we should poll the connection. */
++pcb->polltmr;
if(pcb->polltmr >= pcb->pollinterval &&
pcb->poll != NULL) {
pcb->polltmr = 0;
pcb->poll(pcb->callback_arg, pcb);
tcp_output(pcb);
}
prev = pcb;
pcb = pcb->next;
}
}
/* Steps through all of the TIME-WAIT PCBs. */
prev = NULL;
pcb = tcp_tw_pcbs;
while(pcb != NULL) {
ASSERT("tcp_timer_coarse: TIME-WAIT pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
pcb_remove = 0;
/* Check if this PCB has stayed long enough in TIME-WAIT */
if((uInt32)(tcp_ticks - pcb->tmr) > 2 * TCP_MSL / TCP_SLOW_INTERVAL) {
++pcb_remove;
}
/* If the PCB should be removed, do it. */
if(pcb_remove) {
tcp_pcb_purge(pcb);
/* Remove PCB from tcp_tw_pcbs list. */
if(prev != NULL) {
ASSERT("tcp_timer_coarse: middle tcp != tcp_tw_pcbs", pcb != tcp_tw_pcbs);
prev->next = pcb->next;
} else {
/* This PCB was the first. */
ASSERT("tcp_timer_coarse: first pcb == tcp_tw_pcbs", tcp_tw_pcbs == pcb);
tcp_tw_pcbs = pcb->next;
}
pcb2 = pcb->next;
memp_free(MEMP_TCP_PCB, pcb);
pcb = pcb2;
} else {
prev = pcb;
pcb = pcb->next;
}
}
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_fasttmr():
*
* Is called every TCP_FINE_TIMEOUT (100 ms) and sends delayed ACKs.
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_fasttmr(void)
{
struct tcp_pcb *pcb;
/* send delayed ACKs */
for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
if(pcb->flags & TF_ACK_DELAY) {
DEBUGF(TCP_DEBUG, ("tcp_timer_fine: delayed ACK\n"));
tcp_ack_now(pcb);
pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
}
}
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_segs_free():
*
* Deallocates a list of TCP segments (tcp_seg structures).
*
*/
/*-----------------------------------------------------------------------------------*/
uInt8
tcp_segs_free(struct tcp_seg *seg)
{
uInt8 count = 0;
struct tcp_seg *next;
again:
if(seg != NULL) {
next = seg->next;
count += tcp_seg_free(seg);
seg = next;
goto again;
}
return count;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_seg_free():
*
* Frees a TCP segment.
*
*/
/*-----------------------------------------------------------------------------------*/
uInt8
tcp_seg_free(struct tcp_seg *seg)
{
uInt8 count = 0;
if(seg != NULL) {
if(seg->p == NULL) {
memp_free(MEMP_TCP_SEG, seg);
} else {
count = pbuf_free(seg->p);
#if TCP_DEBUG
seg->p = NULL;
#endif /* TCP_DEBUG */
memp_free(MEMP_TCP_SEG, seg);
}
}
return count;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_seg_copy():
*
* Returns a copy of the given TCP segment.
*
*/
/*-----------------------------------------------------------------------------------*/
struct tcp_seg *
tcp_seg_copy(struct tcp_seg *seg)
{
struct tcp_seg *cseg;
cseg = memp_malloc(MEMP_TCP_SEG);
if(cseg == NULL) {
return NULL;
}
bcopy(seg, cseg, sizeof(struct tcp_seg));
pbuf_ref(cseg->p);
return cseg;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_new():
*
* Creates a new TCP protocol control block but doesn't place it on
* any of the TCP PCB lists.
*
*/
/*-----------------------------------------------------------------------------------*/
struct tcp_pcb *
tcp_new(void)
{
struct tcp_pcb *pcb;
uInt32 iss;
pcb = memp_malloc2(MEMP_TCP_PCB);
if(pcb != NULL) {
bzero(pcb, sizeof(struct tcp_pcb));
pcb->snd_buf = TCP_SND_BUF;
pcb->snd_queuelen = 0;
pcb->rcv_wnd = TCP_WND;
pcb->mss = TCP_MSS;
pcb->rto = 3000 / TCP_SLOW_INTERVAL;
pcb->sa = 0;
pcb->sv = 3000 / TCP_SLOW_INTERVAL;
pcb->rtime = 0;
pcb->cwnd = 1;
iss = tcp_next_iss();
pcb->snd_wl2 = iss;
pcb->snd_nxt = iss;
pcb->snd_max = iss;
pcb->lastack = iss;
pcb->snd_lbb = iss;
pcb->tmr = tcp_ticks;
pcb->polltmr = 0;
return pcb;
}
return NULL;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_mem_reclaim():
*
* Tries to free up TCP memory. This function is called from the memory manager
* when memory is scarce.
*
*/
/*-----------------------------------------------------------------------------------*/
#if MEM_RECLAIM
static mem_size_t
tcp_mem_reclaim(void *arg, mem_size_t size)
{
static struct tcp_pcb *pcb, *inactive;
static uInt32 inactivity;
static mem_size_t reclaimed;
reclaimed = 0;
/* Kill the oldest active connection, hoping that there may be
memory associated with it. */
inactivity = 0;
inactive = NULL;
for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
if((uInt32)(tcp_ticks - pcb->tmr) > inactivity) {
inactivity = tcp_ticks - pcb->tmr;
inactive = pcb;
}
}
if(inactive != NULL) {
DEBUGF(TCP_DEBUG, ("tcp_mem_reclaim: killing oldest PCB 0x%p (%ld)\n",
inactive, inactivity));
tcp_abort(inactive);
}
return reclaimed;
}
#endif /* MEM_RECLAIM */
/*-----------------------------------------------------------------------------------*/
/*
* tcp_memp_reclaim():
*
* Tries to free up TCP memory. This function is called from the
* memory pool manager when memory is scarce.
*
*/
/*-----------------------------------------------------------------------------------*/
#if MEMP_RECLAIM
static uInt8
tcp_memp_reclaim(void *arg, memp_t type)
{
struct tcp_pcb *pcb, *inactive;
uInt32 inactivity;
switch(type) {
case MEMP_TCP_SEG:
#if TCP_QUEUE_OOSEQ
/* Try to find any buffered out of sequence data. */
for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
if(pcb->ooseq) {
DEBUGF(TCP_DEBUG, ("tcp_memp_reclaim: reclaiming memory from PCB 0x%lx\n", (long)pcb));
tcp_segs_free(pcb->ooseq);
pcb->ooseq = NULL;
return 1;
}
}
#else /* TCP_QUEUE_OOSEQ */
return 0;
#endif /* TCP_QUEUE_OOSEQ */
break;
case MEMP_PBUF:
return tcp_memp_reclaim(arg, MEMP_TCP_SEG);
case MEMP_TCP_PCB:
/* We either kill off a connection in TIME-WAIT, or the oldest
active connection. */
pcb = tcp_tw_pcbs;
if(pcb != NULL) {
tcp_tw_pcbs = tcp_tw_pcbs->next;
memp_free(MEMP_TCP_PCB, pcb);
return 1;
} else {
inactivity = 0;
inactive = NULL;
for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
if((uInt32)(tcp_ticks - pcb->tmr) > inactivity) {
inactivity = tcp_ticks - pcb->tmr;
inactive = pcb;
}
}
if(inactive != NULL) {
DEBUGF(TCP_DEBUG, ("tcp_mem_reclaim: killing oldest PCB 0x%p (%ld)\n",
inactive, inactivity));
tcp_abort(inactive);
return 1;
}
}
break;
default:
ASSERT("tcp_memp_reclaim: called with wrong type", 0);
break;
}
return 0;
}
#endif /* MEM_RECLAIM */
/*-----------------------------------------------------------------------------------*/
/*
* tcp_arg():
*
* Used to specify the argument that should be passed callback
* functions.
*
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_arg(struct tcp_pcb *pcb, void *arg)
{
pcb->callback_arg = arg;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_recv():
*
* Used to specify the function that should be called when a TCP
* connection receives data.
*
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_recv(struct tcp_pcb *pcb,
err_t (* recv)(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err))
{
pcb->recv = recv;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_sent():
*
* Used to specify the function that should be called when TCP data
* has been successfully delivered to the remote host.
*
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_sent(struct tcp_pcb *pcb,
err_t (* sent)(void *arg, struct tcp_pcb *tpcb, uInt16 len))
{
pcb->sent = sent;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_err():
*
* Used to specify the function that should be called when a fatal error
* has occured on the connection.
*
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_err(struct tcp_pcb *pcb,
void (* errf)(void *arg, err_t err))
{
pcb->errf = errf;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_poll():
*
* Used to specify the function that should be called periodically
* from TCP. The interval is specified in terms of the TCP coarse
* timer interval, which is called twice a second.
*
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_poll(struct tcp_pcb *pcb,
err_t (* poll)(void *arg, struct tcp_pcb *tpcb), uInt8 interval)
{
pcb->poll = poll;
pcb->pollinterval = interval;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_accept():
*
* Used for specifying the function that should be called when a
* LISTENing connection has been connected to another host.
*
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_accept(struct tcp_pcb *pcb,
err_t (* accept)(void *arg, struct tcp_pcb *newpcb, err_t err))
{
pcb->accept = accept;
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_pcb_purge():
*
* Purges a TCP PCB. Removes any buffered data and frees the buffer memory.
*
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_pcb_purge(struct tcp_pcb *pcb)
{
if(pcb->state != CLOSED &&
pcb->state != TIME_WAIT &&
pcb->state != LISTEN) {
#if TCP_DEBUG
if(pcb->unsent != NULL) {
DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: not all data sent\n"));
}
if(pcb->unacked != NULL) {
DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->unacked\n"));
}
if(pcb->ooseq != NULL) {
DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->ooseq\n"));
}
#endif /* TCP_DEBUG */
tcp_segs_free(pcb->unsent);
#if TCP_QUEUE_OOSEQ
tcp_segs_free(pcb->ooseq);
#endif /* TCP_QUEUE_OOSEQ */
tcp_segs_free(pcb->unacked);
pcb->unacked = pcb->unsent =
#if TCP_QUEUE_OOSEQ
pcb->ooseq =
#endif /* TCP_QUEUE_OOSEQ */
NULL;
}
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_pcb_remove():
*
* Purges the PCB and removes it from a PCB list. Any delayed ACKs are sent first.
*
*/
/*-----------------------------------------------------------------------------------*/
void
tcp_pcb_remove(struct tcp_pcb **pcblist, struct tcp_pcb *pcb)
{
TCP_RMV(pcblist, pcb);
tcp_pcb_purge(pcb);
/* if there is an outstanding delayed ACKs, send it */
if(pcb->state != TIME_WAIT &&
pcb->state != LISTEN &&
pcb->flags & TF_ACK_DELAY) {
pcb->flags |= TF_ACK_NOW;
tcp_output(pcb);
}
pcb->state = CLOSED;
ASSERT("tcp_pcb_remove: tcp_pcbs_sane()", tcp_pcbs_sane());
}
/*-----------------------------------------------------------------------------------*/
/*
* tcp_next_iss():
*
* Calculates a new initial sequence number for new connections.
*
*/
/*-----------------------------------------------------------------------------------*/
uInt32
tcp_next_iss(void)
{
static uInt32 iss = 6510;
iss += tcp_ticks; /* XXX */
return iss;
}
/*-----------------------------------------------------------------------------------*/
#if TCP_DEBUG || TCP_INPUT_DEBUG || TCP_OUTPUT_DEBUG
void
tcp_debug_print(struct tcp_hdr *tcphdr)
{
DEBUGF(TCP_DEBUG, ("TCP header:\n"));
DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
DEBUGF(TCP_DEBUG, ("| %04x | %04x | (src port, dest port)\n",
tcphdr->src, tcphdr->dest));
DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
DEBUGF(TCP_DEBUG, ("| %08lu | (seq no)\n",
tcphdr->seqno));
DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
DEBUGF(TCP_DEBUG, ("| %08lu | (ack no)\n",
tcphdr->ackno));
DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
DEBUGF(TCP_DEBUG, ("| %2d | |%d%d%d%d%d| %5d | (offset, flags (",
TCPH_FLAGS(tcphdr) >> 4 & 1,
TCPH_FLAGS(tcphdr) >> 4 & 1,
TCPH_FLAGS(tcphdr) >> 3 & 1,
TCPH_FLAGS(tcphdr) >> 2 & 1,
TCPH_FLAGS(tcphdr) >> 1 & 1,
TCPH_FLAGS(tcphdr) & 1,
tcphdr->wnd));
tcp_debug_print_flags(TCPH_FLAGS(tcphdr));
DEBUGF(TCP_DEBUG, ("), win)\n"));
DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
DEBUGF(TCP_DEBUG, ("| 0x%04x | %5d | (chksum, urgp)\n",
ntohs(tcphdr->chksum), ntohs(tcphdr->urgp)));
DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
}
/*-----------------------------------------------------------------------------------*/
void
tcp_debug_print_state(enum tcp_state s)
{
DEBUGF(TCP_DEBUG, ("State: "));
switch(s) {
case CLOSED:
DEBUGF(TCP_DEBUG, ("CLOSED\n"));
break;
case LISTEN:
DEBUGF(TCP_DEBUG, ("LISTEN\n"));
break;
case SYN_SENT:
DEBUGF(TCP_DEBUG, ("SYN_SENT\n"));
break;
case SYN_RCVD:
DEBUGF(TCP_DEBUG, ("SYN_RCVD\n"));
break;
case ESTABLISHED:
DEBUGF(TCP_DEBUG, ("ESTABLISHED\n"));
break;
case FIN_WAIT_1:
DEBUGF(TCP_DEBUG, ("FIN_WAIT_1\n"));
break;
case FIN_WAIT_2:
DEBUGF(TCP_DEBUG, ("FIN_WAIT_2\n"));
break;
case CLOSE_WAIT:
DEBUGF(TCP_DEBUG, ("CLOSE_WAIT\n"));
break;
case CLOSING:
DEBUGF(TCP_DEBUG, ("CLOSING\n"));
break;
case LAST_ACK:
DEBUGF(TCP_DEBUG, ("LAST_ACK\n"));
break;
case TIME_WAIT:
DEBUGF(TCP_DEBUG, ("TIME_WAIT\n"));
break;
}
}
/*-----------------------------------------------------------------------------------*/
void
tcp_debug_print_flags(uInt8 flags)
{
if(flags & TCP_FIN) {
DEBUGF(TCP_DEBUG, ("FIN "));
}
if(flags & TCP_SYN) {
DEBUGF(TCP_DEBUG, ("SYN "));
}
if(flags & TCP_RST) {
DEBUGF(TCP_DEBUG, ("RST "));
}
if(flags & TCP_PSH) {
DEBUGF(TCP_DEBUG, ("PSH "));
}
if(flags & TCP_ACK) {
DEBUGF(TCP_DEBUG, ("ACK "));
}
if(flags & TCP_URG) {
DEBUGF(TCP_DEBUG, ("URG "));
}
}
/*-----------------------------------------------------------------------------------*/
void
tcp_debug_print_pcbs(void)
{
struct tcp_pcb *pcb;
DEBUGF(TCP_DEBUG, ("Active PCB states:\n"));
for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
DEBUGF(TCP_DEBUG, ("Local port %d, foreign port %d snd_nxt %lu rcv_nxt %lu ",
pcb->local_port, pcb->remote_port,
pcb->snd_nxt, pcb->rcv_nxt));
tcp_debug_print_state(pcb->state);
}
DEBUGF(TCP_DEBUG, ("Listen PCB states:\n"));
for(pcb = (struct tcp_pcb *)tcp_listen_pcbs; pcb != NULL; pcb = pcb->next) {
DEBUGF(TCP_DEBUG, ("Local port %d, foreign port %d snd_nxt %lu rcv_nxt %lu ",
pcb->local_port, pcb->remote_port,
pcb->snd_nxt, pcb->rcv_nxt));
tcp_debug_print_state(pcb->state);
}
DEBUGF(TCP_DEBUG, ("TIME-WAIT PCB states:\n"));
for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
DEBUGF(TCP_DEBUG, ("Local port %d, foreign port %d snd_nxt %lu rcv_nxt %lu ",
pcb->local_port, pcb->remote_port,
pcb->snd_nxt, pcb->rcv_nxt));
tcp_debug_print_state(pcb->state);
}
}
/*-----------------------------------------------------------------------------------*/
int
tcp_pcbs_sane(void)
{
struct tcp_pcb *pcb;
for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
ASSERT("tcp_pcbs_sane: active pcb->state != CLOSED", pcb->state != CLOSED);
ASSERT("tcp_pcbs_sane: active pcb->state != LISTEN", pcb->state != LISTEN);
ASSERT("tcp_pcbs_sane: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT);
}
for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
ASSERT("tcp_pcbs_sane: tw pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
}
for(pcb = (struct tcp_pcb *)tcp_listen_pcbs; pcb != NULL; pcb = pcb->next) {
ASSERT("tcp_pcbs_sane: listen pcb->state == LISTEN", pcb->state == LISTEN);
}
return 1;
}
#endif /* TCP_DEBUG */
/*-----------------------------------------------------------------------------------*/
