ban4jp -
EthernetNetIf Compatibility.
Dependents: XBeeWiFi_SPI_example
Fork of
NetServicesSource
by 
Donatien Garnier
Diff: lwip/core/tcp.c
- Revision:
- 12:8dc6b255af6c
- Parent:
- 11:da4498f591ee
--- a/lwip/core/tcp.c Thu Aug 05 15:01:33 2010 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,1631 +0,0 @@
-/**
- * @file
- * Transmission Control Protocol for IP
- *
- * 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_in.c and tcp_out.c respectively.
- *
- */
-
-/*
- * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without modification,
- * are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice,
- * this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
- * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
- * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
- * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
- * OF SUCH DAMAGE.
- *
- * This file is part of the lwIP TCP/IP stack.
- *
- * Author: Adam Dunkels <adam@sics.se>
- *
- */
-
-#include "lwip/opt.h"
-
-#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
-
-#include "lwip/def.h"
-#include "lwip/mem.h"
-#include "lwip/memp.h"
-#include "lwip/snmp.h"
-#include "lwip/tcp.h"
-#include "lwip/tcp_impl.h"
-#include "lwip/debug.h"
-#include "lwip/stats.h"
-
-#include <string.h>
-
-const char * const tcp_state_str[] = {
- "CLOSED",
- "LISTEN",
- "SYN_SENT",
- "SYN_RCVD",
- "ESTABLISHED",
- "FIN_WAIT_1",
- "FIN_WAIT_2",
- "CLOSE_WAIT",
- "CLOSING",
- "LAST_ACK",
- "TIME_WAIT"
-};
-
-/* Incremented every coarse grained timer shot (typically every 500 ms). */
-u32_t tcp_ticks;
-const u8_t tcp_backoff[13] =
- { 1, 2, 3, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7};
- /* Times per slowtmr hits */
-const u8_t tcp_persist_backoff[7] = { 3, 6, 12, 24, 48, 96, 120 };
-
-/* The TCP PCB lists. */
-
-/** List of all TCP PCBs bound but not yet (connected || listening) */
-struct tcp_pcb *tcp_bound_pcbs;
-/** List of all TCP PCBs in LISTEN state */
-union tcp_listen_pcbs_t tcp_listen_pcbs;
-/** List of all TCP PCBs that are in a state in which
- * they accept or send data. */
-struct tcp_pcb *tcp_active_pcbs;
-/** List of all TCP PCBs in TIME-WAIT state */
-struct tcp_pcb *tcp_tw_pcbs;
-
-#define NUM_TCP_PCB_LISTS 4
-#define NUM_TCP_PCB_LISTS_NO_TIME_WAIT 3
-/** An array with all (non-temporary) PCB lists, mainly used for smaller code size */
-struct tcp_pcb **tcp_pcb_lists[] = {&tcp_listen_pcbs.pcbs, &tcp_bound_pcbs,
- &tcp_active_pcbs, &tcp_tw_pcbs};
-
-/** Only used for temporary storage. */
-struct tcp_pcb *tcp_tmp_pcb;
-
-/** Timer counter to handle calling slow-timer from tcp_tmr() */
-static u8_t tcp_timer;
-static u16_t tcp_new_port(void);
-
-/**
- * Called periodically to dispatch TCP timers.
- *
- */
-void
-tcp_tmr(void)
-{
- /* Call tcp_fasttmr() every 250 ms */
- tcp_fasttmr();
-
- if (++tcp_timer & 1) {
- /* Call tcp_tmr() every 500 ms, i.e., every other timer
- tcp_tmr() is called. */
- tcp_slowtmr();
- }
-}
-
-/**
- * Closes the TX side of a connection held by the PCB.
- * For tcp_close(), a RST is sent if the application didn't receive all data
- * (tcp_recved() not called for all data passed to recv callback).
- *
- * Listening pcbs are freed and may not be referenced any more.
- * Connection pcbs are freed if not yet connected and may not be referenced
- * any more. If a connection is established (at least SYN received or in
- * a closing state), the connection is closed, and put in a closing state.
- * The pcb is then automatically freed in tcp_slowtmr(). It is therefore
- * unsafe to reference it.
- *
- * @param pcb the tcp_pcb to close
- * @return ERR_OK if connection has been closed
- * another err_t if closing failed and pcb is not freed
- */
-static err_t
-tcp_close_shutdown(struct tcp_pcb *pcb, u8_t rst_on_unacked_data)
-{
- err_t err;
-
- if (rst_on_unacked_data && (pcb->state != LISTEN)) {
- if ((pcb->refused_data != NULL) || (pcb->rcv_wnd != TCP_WND)) {
- /* Not all data received by application, send RST to tell the remote
- side about this. */
- LWIP_ASSERT("pcb->flags & TF_RXCLOSED", pcb->flags & TF_RXCLOSED);
-
- /* don't call tcp_abort here: we must not deallocate the pcb since
- that might not be expected when calling tcp_close */
- tcp_rst(pcb->snd_nxt, pcb->rcv_nxt, &pcb->local_ip, &pcb->remote_ip,
- pcb->local_port, pcb->remote_port);
-
- tcp_pcb_purge(pcb);
-
- /* TODO: to which state do we move now? */
-
- /* move to TIME_WAIT since we close actively */
- TCP_RMV(&tcp_active_pcbs, pcb);
- pcb->state = TIME_WAIT;
- TCP_REG(&tcp_tw_pcbs, pcb);
-
- return ERR_OK;
- }
- }
-
- switch (pcb->state) {
- case CLOSED:
- /* Closing a pcb in the CLOSED state might seem erroneous,
- * however, it is in this state once allocated and as yet unused
- * and the user needs some way to free it should the need arise.
- * Calling tcp_close() with a pcb that has already been closed, (i.e. twice)
- * or for a pcb that has been used and then entered the CLOSED state
- * is erroneous, but this should never happen as the pcb has in those cases
- * been freed, and so any remaining handles are bogus. */
- err = ERR_OK;
- TCP_RMV(&tcp_bound_pcbs, pcb);
- memp_free(MEMP_TCP_PCB, pcb);
- pcb = NULL;
- break;
- case LISTEN:
- err = ERR_OK;
- tcp_pcb_remove(&tcp_listen_pcbs.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;
- snmp_inc_tcpattemptfails();
- break;
- case SYN_RCVD:
- err = tcp_send_fin(pcb);
- if (err == ERR_OK) {
- snmp_inc_tcpattemptfails();
- pcb->state = FIN_WAIT_1;
- }
- break;
- case ESTABLISHED:
- err = tcp_send_fin(pcb);
- if (err == ERR_OK) {
- snmp_inc_tcpestabresets();
- pcb->state = FIN_WAIT_1;
- }
- break;
- case CLOSE_WAIT:
- err = tcp_send_fin(pcb);
- if (err == ERR_OK) {
- snmp_inc_tcpestabresets();
- pcb->state = LAST_ACK;
- }
- break;
- default:
- /* Has already been closed, do nothing. */
- err = ERR_OK;
- pcb = NULL;
- break;
- }
-
- if (pcb != NULL && err == ERR_OK) {
- /* To ensure all data has been sent when tcp_close returns, we have
- to make sure tcp_output doesn't fail.
- Since we don't really have to ensure all data has been sent when tcp_close
- returns (unsent data is sent from tcp timer functions, also), we don't care
- for the return value of tcp_output for now. */
- /* @todo: When implementing SO_LINGER, this must be changed somehow:
- If SOF_LINGER is set, the data should be sent and acked before close returns.
- This can only be valid for sequential APIs, not for the raw API. */
- tcp_output(pcb);
- }
- return err;
-}
-
-/**
- * Closes the connection held by the PCB.
- *
- * Listening pcbs are freed and may not be referenced any more.
- * Connection pcbs are freed if not yet connected and may not be referenced
- * any more. If a connection is established (at least SYN received or in
- * a closing state), the connection is closed, and put in a closing state.
- * The pcb is then automatically freed in tcp_slowtmr(). It is therefore
- * unsafe to reference it (unless an error is returned).
- *
- * @param pcb the tcp_pcb to close
- * @return ERR_OK if connection has been closed
- * another err_t if closing failed and pcb is not freed
- */
-err_t
-tcp_close(struct tcp_pcb *pcb)
-{
-#if TCP_DEBUG
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_close: closing in "));
- tcp_debug_print_state(pcb->state);
-#endif /* TCP_DEBUG */
-
- if (pcb->state != LISTEN) {
- /* Set a flag not to receive any more data... */
- pcb->flags |= TF_RXCLOSED;
- }
- /* ... and close */
- return tcp_close_shutdown(pcb, 1);
-}
-
-/**
- * Causes all or part of a full-duplex connection of this PCB to be shut down.
- * This doesn't deallocate the PCB!
- *
- * @param pcb PCB to shutdown
- * @param shut_rx shut down receive side if this is != 0
- * @param shut_tx shut down send side if this is != 0
- * @return ERR_OK if shutdown succeeded (or the PCB has already been shut down)
- * another err_t on error.
- */
-err_t
-tcp_shutdown(struct tcp_pcb *pcb, int shut_rx, int shut_tx)
-{
- if (pcb->state == LISTEN) {
- return ERR_CONN;
- }
- if (shut_rx) {
- /* shut down the receive side: free buffered data... */
- if (pcb->refused_data != NULL) {
- pbuf_free(pcb->refused_data);
- pcb->refused_data = NULL;
- }
- /* ... and set a flag not to receive any more data */
- pcb->flags |= TF_RXCLOSED;
- }
- if (shut_tx) {
- /* This can't happen twice since if it succeeds, the pcb's state is changed.
- Only close in these states as the others directly deallocate the PCB */
- switch (pcb->state) {
- case SYN_RCVD:
- case ESTABLISHED:
- case CLOSE_WAIT:
- return tcp_close_shutdown(pcb, 0);
- default:
- /* don't shut down other states */
- break;
- }
- }
- /* @todo: return another err_t if not in correct state or already shut? */
- return ERR_OK;
-}
-
-/**
- * Abandons a connection and optionally sends a RST to the remote
- * host. Deletes the local protocol control block. This is done when
- * a connection is killed because of shortage of memory.
- *
- * @param pcb the tcp_pcb to abort
- * @param reset boolean to indicate whether a reset should be sent
- */
-void
-tcp_abandon(struct tcp_pcb *pcb, int reset)
-{
- u32_t seqno, ackno;
- u16_t remote_port, local_port;
- ip_addr_t remote_ip, local_ip;
-#if LWIP_CALLBACK_API
- tcp_err_fn errf;
-#endif /* LWIP_CALLBACK_API */
- void *errf_arg;
-
- /* pcb->state LISTEN not allowed here */
- LWIP_ASSERT("don't call tcp_abort/tcp_abandon for listen-pcbs",
- pcb->state != LISTEN);
- /* 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 {
- seqno = pcb->snd_nxt;
- ackno = pcb->rcv_nxt;
- ip_addr_copy(local_ip, pcb->local_ip);
- ip_addr_copy(remote_ip, pcb->remote_ip);
- local_port = pcb->local_port;
- remote_port = pcb->remote_port;
-#if LWIP_CALLBACK_API
- errf = pcb->errf;
-#endif /* LWIP_CALLBACK_API */
- errf_arg = pcb->callback_arg;
- tcp_pcb_remove(&tcp_active_pcbs, pcb);
- if (pcb->unacked != NULL) {
- tcp_segs_free(pcb->unacked);
- }
- if (pcb->unsent != NULL) {
- tcp_segs_free(pcb->unsent);
- }
-#if TCP_QUEUE_OOSEQ
- if (pcb->ooseq != NULL) {
- tcp_segs_free(pcb->ooseq);
- }
-#endif /* TCP_QUEUE_OOSEQ */
- memp_free(MEMP_TCP_PCB, pcb);
- TCP_EVENT_ERR(errf, errf_arg, ERR_ABRT);
- if (reset) {
- LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_abandon: sending RST\n"));
- tcp_rst(seqno, ackno, &local_ip, &remote_ip, local_port, remote_port);
- }
- }
-}
-
-/**
- * Aborts the connection by sending a RST (reset) segment to the remote
- * host. The pcb is deallocated. This function never fails.
- *
- * ATTENTION: When calling this from one of the TCP callbacks, make
- * sure you always return ERR_ABRT (and never return ERR_ABRT otherwise
- * or you will risk accessing deallocated memory or memory leaks!
- *
- * @param pcb the tcp pcb to abort
- */
-void
-tcp_abort(struct tcp_pcb *pcb)
-{
- tcp_abandon(pcb, 1);
-}
-
-/**
- * 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.
- *
- * @param pcb the tcp_pcb to bind (no check is done whether this pcb is
- * already bound!)
- * @param ipaddr the local ip address to bind to (use IP_ADDR_ANY to bind
- * to any local address
- * @param port the local port to bind to
- * @return ERR_USE if the port is already in use
- * ERR_OK if bound
- */
-err_t
-tcp_bind(struct tcp_pcb *pcb, ip_addr_t *ipaddr, u16_t port)
-{
- int i;
- int max_pcb_list = NUM_TCP_PCB_LISTS;
- struct tcp_pcb *cpcb;
-
- LWIP_ERROR("tcp_bind: can only bind in state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
-
-#if SO_REUSE
- /* Unless the REUSEADDR flag is set,
- we have to check the pcbs in TIME-WAIT state, also.
- We do not dump TIME_WAIT pcb's; they can still be matched by incoming
- packets using both local and remote IP addresses and ports to distinguish.
- */
-#if SO_REUSE
- if ((pcb->so_options & SOF_REUSEADDR) != 0) {
- max_pcb_list = NUM_TCP_PCB_LISTS_NO_TIME_WAIT;
- }
-#endif /* SO_REUSE */
-#endif /* SO_REUSE */
-
- if (port == 0) {
- port = tcp_new_port();
- }
-
- /* Check if the address already is in use (on all lists) */
- for (i = 0; i < max_pcb_list; i++) {
- for(cpcb = *tcp_pcb_lists[i]; cpcb != NULL; cpcb = cpcb->next) {
- if (cpcb->local_port == port) {
-#if SO_REUSE
- /* Omit checking for the same port if both pcbs have REUSEADDR set.
- For SO_REUSEADDR, the duplicate-check for a 5-tuple is done in
- tcp_connect. */
- if (((pcb->so_options & SOF_REUSEADDR) == 0) ||
- ((cpcb->so_options & SOF_REUSEADDR) == 0))
-#endif /* SO_REUSE */
- {
- 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;
- TCP_REG(&tcp_bound_pcbs, pcb);
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_bind: bind to port %"U16_F"\n", port));
- return ERR_OK;
-}
-#if LWIP_CALLBACK_API
-/**
- * Default accept callback if no accept callback is specified by the user.
- */
-static err_t
-tcp_accept_null(void *arg, struct tcp_pcb *pcb, err_t err)
-{
- LWIP_UNUSED_ARG(arg);
- LWIP_UNUSED_ARG(pcb);
- LWIP_UNUSED_ARG(err);
-
- return ERR_ABRT;
-}
-#endif /* LWIP_CALLBACK_API */
-
-/**
- * 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.
- *
- * @param pcb the original tcp_pcb
- * @param backlog the incoming connections queue limit
- * @return tcp_pcb used for listening, consumes less memory.
- *
- * @note The original tcp_pcb is freed. This function therefore has to be
- * called like this:
- * tpcb = tcp_listen(tpcb);
- */
-struct tcp_pcb *
-tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog)
-{
- struct tcp_pcb_listen *lpcb;
-
- LWIP_UNUSED_ARG(backlog);
- LWIP_ERROR("tcp_listen: pcb already connected", pcb->state == CLOSED, return NULL);
-
- /* already listening? */
- if (pcb->state == LISTEN) {
- return pcb;
- }
-#if SO_REUSE
- if ((pcb->so_options & SOF_REUSEADDR) != 0) {
- /* Since SOF_REUSEADDR allows reusing a local address before the pcb's usage
- is declared (listen-/connection-pcb), we have to make sure now that
- this port is only used once for every local IP. */
- for(lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
- if (lpcb->local_port == pcb->local_port) {
- if (ip_addr_cmp(&lpcb->local_ip, &pcb->local_ip)) {
- /* this address/port is already used */
- return NULL;
- }
- }
- }
- }
-#endif /* SO_REUSE */
- lpcb = (struct tcp_pcb_listen *)memp_malloc(MEMP_TCP_PCB_LISTEN);
- if (lpcb == NULL) {
- return NULL;
- }
- lpcb->callback_arg = pcb->callback_arg;
- lpcb->local_port = pcb->local_port;
- lpcb->state = LISTEN;
- lpcb->prio = pcb->prio;
- lpcb->so_options = pcb->so_options;
- lpcb->so_options |= SOF_ACCEPTCONN;
- lpcb->ttl = pcb->ttl;
- lpcb->tos = pcb->tos;
- ip_addr_copy(lpcb->local_ip, pcb->local_ip);
- TCP_RMV(&tcp_bound_pcbs, pcb);
- memp_free(MEMP_TCP_PCB, pcb);
-#if LWIP_CALLBACK_API
- lpcb->accept = tcp_accept_null;
-#endif /* LWIP_CALLBACK_API */
-#if TCP_LISTEN_BACKLOG
- lpcb->accepts_pending = 0;
- lpcb->backlog = (backlog ? backlog : 1);
-#endif /* TCP_LISTEN_BACKLOG */
- TCP_REG(&tcp_listen_pcbs.pcbs, (struct tcp_pcb *)lpcb);
- return (struct tcp_pcb *)lpcb;
-}
-
-/**
- * Update the state that tracks the available window space to advertise.
- *
- * Returns how much extra window would be advertised if we sent an
- * update now.
- */
-u32_t tcp_update_rcv_ann_wnd(struct tcp_pcb *pcb)
-{
- u32_t new_right_edge = pcb->rcv_nxt + pcb->rcv_wnd;
-
- if (TCP_SEQ_GEQ(new_right_edge, pcb->rcv_ann_right_edge + LWIP_MIN((TCP_WND / 2), pcb->mss))) {
- /* we can advertise more window */
- pcb->rcv_ann_wnd = pcb->rcv_wnd;
- return new_right_edge - pcb->rcv_ann_right_edge;
- } else {
- if (TCP_SEQ_GT(pcb->rcv_nxt, pcb->rcv_ann_right_edge)) {
- /* Can happen due to other end sending out of advertised window,
- * but within actual available (but not yet advertised) window */
- pcb->rcv_ann_wnd = 0;
- } else {
- /* keep the right edge of window constant */
- u32_t new_rcv_ann_wnd = pcb->rcv_ann_right_edge - pcb->rcv_nxt;
- LWIP_ASSERT("new_rcv_ann_wnd <= 0xffff", new_rcv_ann_wnd <= 0xffff);
- pcb->rcv_ann_wnd = (u16_t)new_rcv_ann_wnd;
- }
- return 0;
- }
-}
-
-/**
- * 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.
- *
- * @param pcb the tcp_pcb for which data is read
- * @param len the amount of bytes that have been read by the application
- */
-void
-tcp_recved(struct tcp_pcb *pcb, u16_t len)
-{
- int wnd_inflation;
-
- LWIP_ASSERT("tcp_recved: len would wrap rcv_wnd\n",
- len <= 0xffff - pcb->rcv_wnd );
-
- pcb->rcv_wnd += len;
- if (pcb->rcv_wnd > TCP_WND) {
- pcb->rcv_wnd = TCP_WND;
- }
-
- wnd_inflation = tcp_update_rcv_ann_wnd(pcb);
-
- /* If the change in the right edge of window is significant (default
- * watermark is TCP_WND/4), then send an explicit update now.
- * Otherwise wait for a packet to be sent in the normal course of
- * events (or more window to be available later) */
- if (wnd_inflation >= TCP_WND_UPDATE_THRESHOLD) {
- tcp_ack_now(pcb);
- tcp_output(pcb);
- }
-
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_recved: recveived %"U16_F" bytes, wnd %"U16_F" (%"U16_F").\n",
- len, pcb->rcv_wnd, TCP_WND - pcb->rcv_wnd));
-}
-
-/**
- * A nastly hack featuring 'goto' statements that allocates a
- * new TCP local port.
- *
- * @return a new (free) local TCP port number
- */
-static u16_t
-tcp_new_port(void)
-{
- int i;
- struct tcp_pcb *pcb;
-#ifndef TCP_LOCAL_PORT_RANGE_START
-#define TCP_LOCAL_PORT_RANGE_START 4096
-#define TCP_LOCAL_PORT_RANGE_END 0x7fff
-#endif
- static u16_t port = TCP_LOCAL_PORT_RANGE_START;
-
- again:
- if (++port > TCP_LOCAL_PORT_RANGE_END) {
- port = TCP_LOCAL_PORT_RANGE_START;
- }
- /* Check all PCB lists. */
- for (i = 1; i < NUM_TCP_PCB_LISTS; i++) {
- for(pcb = *tcp_pcb_lists[i]; pcb != NULL; pcb = pcb->next) {
- if (pcb->local_port == port) {
- goto again;
- }
- }
- }
- return port;
-}
-
-/**
- * Connects to another host. The function given as the "connected"
- * argument will be called when the connection has been established.
- *
- * @param pcb the tcp_pcb used to establish the connection
- * @param ipaddr the remote ip address to connect to
- * @param port the remote tcp port to connect to
- * @param connected callback function to call when connected (or on error)
- * @return ERR_VAL if invalid arguments are given
- * ERR_OK if connect request has been sent
- * other err_t values if connect request couldn't be sent
- */
-err_t
-tcp_connect(struct tcp_pcb *pcb, ip_addr_t *ipaddr, u16_t port,
- tcp_connected_fn connected)
-{
- err_t ret;
- u32_t iss;
-
- LWIP_ERROR("tcp_connect: can only connected from state CLOSED", pcb->state == CLOSED, return ERR_ISCONN);
-
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_connect to port %"U16_F"\n", port));
- if (ipaddr != NULL) {
- pcb->remote_ip = *ipaddr;
- } else {
- return ERR_VAL;
- }
- pcb->remote_port = port;
-
- /* check if we have a route to the remote host */
- if (ip_addr_isany(&(pcb->local_ip))) {
- /* no local IP address set, yet. */
- struct netif *netif = ip_route(&(pcb->remote_ip));
- if (netif == NULL) {
- /* Don't even try to send a SYN packet if we have no route
- since that will fail. */
- return ERR_RTE;
- }
- /* Use the netif's IP address as local address. */
- ip_addr_copy(pcb->local_ip, netif->ip_addr);
- }
-
- if (pcb->local_port == 0) {
- pcb->local_port = tcp_new_port();
- }
-#if SO_REUSE
- if ((pcb->so_options & SOF_REUSEADDR) != 0) {
- /* Since SOF_REUSEADDR allows reusing a local address, we have to make sure
- now that the 5-tuple is unique. */
- struct tcp_pcb *cpcb;
- int i;
- /* Don't check listen PCBs, check bound-, active- and TIME-WAIT PCBs. */
- for (i = 1; i < NUM_TCP_PCB_LISTS; i++) {
- for(cpcb = *tcp_pcb_lists[i]; cpcb != NULL; cpcb = cpcb->next) {
- if ((cpcb->local_port == pcb->local_port) &&
- (cpcb->remote_port == port) &&
- ip_addr_cmp(&cpcb->local_ip, &pcb->local_ip) &&
- ip_addr_cmp(&cpcb->remote_ip, ipaddr)) {
- /* linux returns EISCONN here, but ERR_USE should be OK for us */
- return ERR_USE;
- }
- }
- }
- }
-#endif /* SO_REUSE */
- 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->rcv_ann_wnd = TCP_WND;
- pcb->rcv_ann_right_edge = pcb->rcv_nxt;
- pcb->snd_wnd = TCP_WND;
- /* As initial send MSS, we use TCP_MSS but limit it to 536.
- The send MSS is updated when an MSS option is received. */
- pcb->mss = (TCP_MSS > 536) ? 536 : TCP_MSS;
-#if TCP_CALCULATE_EFF_SEND_MSS
- pcb->mss = tcp_eff_send_mss(pcb->mss, ipaddr);
-#endif /* TCP_CALCULATE_EFF_SEND_MSS */
- pcb->cwnd = 1;
- pcb->ssthresh = pcb->mss * 10;
-#if LWIP_CALLBACK_API
- pcb->connected = connected;
-#else /* LWIP_CALLBACK_API */
- LWIP_UNUSED_ARG(connected);
-#endif /* LWIP_CALLBACK_API */
-
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_connect: tcp_ticks=%"U32_F" iss=%"U32_F"\n", tcp_ticks, iss));
-
- /* Send a SYN together with the MSS option. */
- ret = tcp_enqueue_flags(pcb, TCP_SYN);
- if (ret == ERR_OK) {
- /* SYN segment was enqueued, changed the pcbs state now */
- pcb->state = SYN_SENT;
- TCP_RMV(&tcp_bound_pcbs, pcb);
- TCP_REG(&tcp_active_pcbs, pcb);
- snmp_inc_tcpactiveopens();
-
- tcp_output(pcb);
- }
- return ret;
-}
-
-/**
- * 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.
- *
- * Automatically called from tcp_tmr().
- */
-void
-tcp_slowtmr(void)
-{
- struct tcp_pcb *pcb, *pcb2, *prev;
- u16_t eff_wnd;
- u8_t pcb_remove; /* flag if a PCB should be removed */
- u8_t pcb_reset; /* flag if a RST should be sent when removing */
- err_t err;
-
- tcp_debug_print_pcbs(); //DG
-
- err = ERR_OK;
-
- ++tcp_ticks;
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: tcp_ticks=%"U32_F"\n", tcp_ticks));
-
- /* Steps through all of the active PCBs. */
- prev = NULL;
- pcb = tcp_active_pcbs;
- if (pcb == NULL) {
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: no active pcbs\n"));
- }
- while (pcb != NULL) {
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: processing active pcb\n"));
- LWIP_ASSERT("tcp_slowtmr: active pcb->state != CLOSED\n", pcb->state != CLOSED);
- LWIP_ASSERT("tcp_slowtmr: active pcb->state != LISTEN\n", pcb->state != LISTEN);
- LWIP_ASSERT("tcp_slowtmr: active pcb->state != TIME-WAIT\n", pcb->state != TIME_WAIT);
-
- pcb_remove = 0;
- pcb_reset = 0;
-
- if (pcb->state == SYN_SENT && pcb->nrtx == TCP_SYNMAXRTX) {
- ++pcb_remove;
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max SYN retries reached\n"));
- }
- else if (pcb->nrtx == TCP_MAXRTX) {
- ++pcb_remove;
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: max DATA retries reached\n"));
- } else {
- if (pcb->persist_backoff > 0) {
- /* If snd_wnd is zero, use persist timer to send 1 byte probes
- * instead of using the standard retransmission mechanism. */
- pcb->persist_cnt++;
- if (pcb->persist_cnt >= tcp_persist_backoff[pcb->persist_backoff-1]) {
- pcb->persist_cnt = 0;
- if (pcb->persist_backoff < sizeof(tcp_persist_backoff)) {
- pcb->persist_backoff++;
- }
- tcp_zero_window_probe(pcb);
- }
- } else {
- /* Increase the retransmission timer if it is running */
- if(pcb->rtime >= 0)
- ++pcb->rtime;
-
- if (pcb->unacked != NULL && pcb->rtime >= pcb->rto) {
- /* Time for a retransmission. */
- LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_slowtmr: rtime %"S16_F
- " pcb->rto %"S16_F"\n",
- 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];
- }
-
- /* Reset the retransmission timer. */
- pcb->rtime = 0;
-
- /* Reduce congestion window and ssthresh. */
- eff_wnd = LWIP_MIN(pcb->cwnd, pcb->snd_wnd);
- pcb->ssthresh = eff_wnd >> 1;
- if (pcb->ssthresh < (pcb->mss << 1)) {
- pcb->ssthresh = (pcb->mss << 1);
- }
- pcb->cwnd = pcb->mss;
- LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: cwnd %"U16_F
- " ssthresh %"U16_F"\n",
- pcb->cwnd, pcb->ssthresh));
-
- /* The following needs to be called AFTER cwnd is set to one
- mss - STJ */
- tcp_rexmit_rto(pcb);
- }
- }
- }
- /* Check if this PCB has stayed too long in FIN-WAIT-2 */
- if (pcb->state == FIN_WAIT_2) {
- if ((u32_t)(tcp_ticks - pcb->tmr) >
- TCP_FIN_WAIT_TIMEOUT / TCP_SLOW_INTERVAL) {
- ++pcb_remove;
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in FIN-WAIT-2\n"));
- }
- }
-
- /* Check if KEEPALIVE should be sent */
- if((pcb->so_options & SOF_KEEPALIVE) &&
- ((pcb->state == ESTABLISHED) ||
- (pcb->state == CLOSE_WAIT))) {
-#if LWIP_TCP_KEEPALIVE
- if((u32_t)(tcp_ticks - pcb->tmr) >
- (pcb->keep_idle + (pcb->keep_cnt*pcb->keep_intvl))
- / TCP_SLOW_INTERVAL)
-#else
- if((u32_t)(tcp_ticks - pcb->tmr) >
- (pcb->keep_idle + TCP_MAXIDLE) / TCP_SLOW_INTERVAL)
-#endif /* LWIP_TCP_KEEPALIVE */
- {
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: KEEPALIVE timeout. Aborting connection to %"U16_F".%"U16_F".%"U16_F".%"U16_F".\n",
- ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip),
- ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip)));
-
- ++pcb_remove;
- ++pcb_reset;
- }
-#if LWIP_TCP_KEEPALIVE
- else if((u32_t)(tcp_ticks - pcb->tmr) >
- (pcb->keep_idle + pcb->keep_cnt_sent * pcb->keep_intvl)
- / TCP_SLOW_INTERVAL)
-#else
- else if((u32_t)(tcp_ticks - pcb->tmr) >
- (pcb->keep_idle + pcb->keep_cnt_sent * TCP_KEEPINTVL_DEFAULT)
- / TCP_SLOW_INTERVAL)
-#endif /* LWIP_TCP_KEEPALIVE */
- {
- tcp_keepalive(pcb);
- pcb->keep_cnt_sent++;
- }
- }
-
- /* 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 &&
- (u32_t)tcp_ticks - pcb->tmr >= pcb->rto * TCP_OOSEQ_TIMEOUT) {
- tcp_segs_free(pcb->ooseq);
- pcb->ooseq = NULL;
- LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_slowtmr: dropping OOSEQ queued data\n"));
- }
-#endif /* TCP_QUEUE_OOSEQ */
-
- /* Check if this PCB has stayed too long in SYN-RCVD */
- if (pcb->state == SYN_RCVD) {
- if ((u32_t)(tcp_ticks - pcb->tmr) >
- TCP_SYN_RCVD_TIMEOUT / TCP_SLOW_INTERVAL) {
- ++pcb_remove;
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in SYN-RCVD\n"));
- }
- }
-
- /* Check if this PCB has stayed too long in LAST-ACK */
- if (pcb->state == LAST_ACK) {
- if ((u32_t)(tcp_ticks - pcb->tmr) > 2 * TCP_MSL / TCP_SLOW_INTERVAL) {
- ++pcb_remove;
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: removing pcb stuck in LAST-ACK\n"));
- }
- }
-
- /* 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) {
- LWIP_ASSERT("tcp_slowtmr: middle tcp != tcp_active_pcbs", pcb != tcp_active_pcbs);
- prev->next = pcb->next;
- } else {
- /* This PCB was the first. */
- LWIP_ASSERT("tcp_slowtmr: first pcb == tcp_active_pcbs", tcp_active_pcbs == pcb);
- tcp_active_pcbs = pcb->next;
- }
-
- TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_ABRT);
- if (pcb_reset) {
- tcp_rst(pcb->snd_nxt, pcb->rcv_nxt, &pcb->local_ip, &pcb->remote_ip,
- pcb->local_port, pcb->remote_port);
- }
-
- pcb2 = pcb->next;
- memp_free(MEMP_TCP_PCB, pcb);
- pcb = pcb2;
- } else {
- /* get the 'next' element now and work with 'prev' below (in case of abort) */
- prev = pcb;
- pcb = pcb->next;
-
- /* We check if we should poll the connection. */
- ++prev->polltmr;
- if (prev->polltmr >= prev->pollinterval) {
- prev->polltmr = 0;
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_slowtmr: polling application\n"));
- TCP_EVENT_POLL(prev, err);
- /* if err == ERR_ABRT, 'prev' is already deallocated */
- if (err == ERR_OK) {
- tcp_output(prev);
- }
- }
- }
- }
-
-
- /* Steps through all of the TIME-WAIT PCBs. */
- prev = NULL;
- pcb = tcp_tw_pcbs;
- while (pcb != NULL) {
- LWIP_ASSERT("tcp_slowtmr: 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 ((u32_t)(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) {
- LWIP_ASSERT("tcp_slowtmr: middle tcp != tcp_tw_pcbs", pcb != tcp_tw_pcbs);
- prev->next = pcb->next;
- } else {
- /* This PCB was the first. */
- LWIP_ASSERT("tcp_slowtmr: 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;
- }
- }
-}
-
-/**
- * Is called every TCP_FAST_INTERVAL (250 ms) and process data previously
- * "refused" by upper layer (application) and sends delayed ACKs.
- *
- * Automatically called from tcp_tmr().
- */
-void
-tcp_fasttmr(void)
-{
- struct tcp_pcb *pcb = tcp_active_pcbs;
-
- while(pcb != NULL) {
- struct tcp_pcb *next = pcb->next;
- /* If there is data which was previously "refused" by upper layer */
- if (pcb->refused_data != NULL) {
- /* Notify again application with data previously received. */
- err_t err;
- LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_fasttmr: notify kept packet\n"));
- TCP_EVENT_RECV(pcb, pcb->refused_data, ERR_OK, err);
- if (err == ERR_OK) {
- pcb->refused_data = NULL;
- } else if (err == ERR_ABRT) {
- /* if err == ERR_ABRT, 'pcb' is already deallocated */
- pcb = NULL;
- }
- }
-
- /* send delayed ACKs */
- if (pcb && (pcb->flags & TF_ACK_DELAY)) {
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_fasttmr: delayed ACK\n"));
- tcp_ack_now(pcb);
- tcp_output(pcb);
- pcb->flags &= ~(TF_ACK_DELAY | TF_ACK_NOW);
- }
-
- pcb = next;
- }
-}
-
-/**
- * Deallocates a list of TCP segments (tcp_seg structures).
- *
- * @param seg tcp_seg list of TCP segments to free
- */
-void
-tcp_segs_free(struct tcp_seg *seg)
-{
- while (seg != NULL) {
- struct tcp_seg *next = seg->next;
- tcp_seg_free(seg);
- seg = next;
- }
-}
-
-/**
- * Frees a TCP segment (tcp_seg structure).
- *
- * @param seg single tcp_seg to free
- */
-void
-tcp_seg_free(struct tcp_seg *seg)
-{
- if (seg != NULL) {
- if (seg->p != NULL) {
- pbuf_free(seg->p);
-#if TCP_DEBUG
- seg->p = NULL;
-#endif /* TCP_DEBUG */
- }
- memp_free(MEMP_TCP_SEG, seg);
- }
-}
-
-/**
- * Sets the priority of a connection.
- *
- * @param pcb the tcp_pcb to manipulate
- * @param prio new priority
- */
-void
-tcp_setprio(struct tcp_pcb *pcb, u8_t prio)
-{
- pcb->prio = prio;
-}
-
-#if TCP_QUEUE_OOSEQ
-/**
- * Returns a copy of the given TCP segment.
- * The pbuf and data are not copied, only the pointers
- *
- * @param seg the old tcp_seg
- * @return a copy of seg
- */
-struct tcp_seg *
-tcp_seg_copy(struct tcp_seg *seg)
-{
- struct tcp_seg *cseg;
-
- cseg = (struct tcp_seg *)memp_malloc(MEMP_TCP_SEG);
- if (cseg == NULL) {
- return NULL;
- }
- SMEMCPY((u8_t *)cseg, (const u8_t *)seg, sizeof(struct tcp_seg));
- pbuf_ref(cseg->p);
- return cseg;
-}
-#endif /* TCP_QUEUE_OOSEQ */
-
-#if LWIP_CALLBACK_API
-/**
- * Default receive callback that is called if the user didn't register
- * a recv callback for the pcb.
- */
-err_t
-tcp_recv_null(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err)
-{
- LWIP_UNUSED_ARG(arg);
- if (p != NULL) {
- tcp_recved(pcb, p->tot_len);
- pbuf_free(p);
- } else if (err == ERR_OK) {
- return tcp_close(pcb);
- }
- return ERR_OK;
-}
-#endif /* LWIP_CALLBACK_API */
-
-/**
- * Kills the oldest active connection that has lower priority than prio.
- *
- * @param prio minimum priority
- */
-static void
-tcp_kill_prio(u8_t prio)
-{
- struct tcp_pcb *pcb, *inactive;
- u32_t inactivity;
- u8_t mprio;
-
-
- mprio = TCP_PRIO_MAX;
-
- /* We kill the oldest active connection that has lower priority than prio. */
- inactivity = 0;
- inactive = NULL;
- for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
- if (pcb->prio <= prio &&
- pcb->prio <= mprio &&
- (u32_t)(tcp_ticks - pcb->tmr) >= inactivity) {
- inactivity = tcp_ticks - pcb->tmr;
- inactive = pcb;
- mprio = pcb->prio;
- }
- }
- if (inactive != NULL) {
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_kill_prio: killing oldest PCB %p (%"S32_F")\n",
- (void *)inactive, inactivity));
- tcp_abort(inactive);
- }
-}
-
-/**
- * Kills the oldest connection that is in TIME_WAIT state.
- * Called from tcp_alloc() if no more connections are available.
- */
-static void
-tcp_kill_timewait(void)
-{
- struct tcp_pcb *pcb, *inactive;
- u32_t inactivity;
-
- inactivity = 0;
- inactive = NULL;
- /* Go through the list of TIME_WAIT pcbs and get the oldest pcb. */
- for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
- if ((u32_t)(tcp_ticks - pcb->tmr) >= inactivity) {
- inactivity = tcp_ticks - pcb->tmr;
- inactive = pcb;
- }
- }
- if (inactive != NULL) {
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_kill_timewait: killing oldest TIME-WAIT PCB %p (%"S32_F")\n",
- (void *)inactive, inactivity));
- tcp_abort(inactive);
- }
-}
-
-/**
- * Allocate a new tcp_pcb structure.
- *
- * @param prio priority for the new pcb
- * @return a new tcp_pcb that initially is in state CLOSED
- */
-struct tcp_pcb *
-tcp_alloc(u8_t prio)
-{
- struct tcp_pcb *pcb;
- u32_t iss;
-
- pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
- if (pcb == NULL) {
- /* Try killing oldest connection in TIME-WAIT. */
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_alloc: killing off oldest TIME-WAIT connection\n"));
- tcp_kill_timewait();
- /* Try to allocate a tcp_pcb again. */
- pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
- if (pcb == NULL) {
- /* Try killing active connections with lower priority than the new one. */
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_alloc: killing connection with prio lower than %d\n", prio));
- tcp_kill_prio(prio);
- /* Try to allocate a tcp_pcb again. */
- pcb = (struct tcp_pcb *)memp_malloc(MEMP_TCP_PCB);
- if (pcb != NULL) {
- /* adjust err stats: memp_malloc failed twice before */
- MEMP_STATS_DEC(err, MEMP_TCP_PCB);
- }
- }
- if (pcb != NULL) {
- /* adjust err stats: timewait PCB was freed above */
- MEMP_STATS_DEC(err, MEMP_TCP_PCB);
- }
- }
- if (pcb != NULL) {
- memset(pcb, 0, sizeof(struct tcp_pcb));
- pcb->prio = prio;
- pcb->snd_buf = TCP_SND_BUF;
- pcb->snd_queuelen = 0;
- pcb->rcv_wnd = TCP_WND;
- pcb->rcv_ann_wnd = TCP_WND;
- pcb->tos = 0;
- pcb->ttl = TCP_TTL;
- /* As initial send MSS, we use TCP_MSS but limit it to 536.
- The send MSS is updated when an MSS option is received. */
- pcb->mss = (TCP_MSS > 536) ? 536 : TCP_MSS;
- pcb->rto = 3000 / TCP_SLOW_INTERVAL;
- pcb->sa = 0;
- pcb->sv = 3000 / TCP_SLOW_INTERVAL;
- pcb->rtime = -1;
- pcb->cwnd = 1;
- iss = tcp_next_iss();
- pcb->snd_wl2 = iss;
- pcb->snd_nxt = iss;
- pcb->lastack = iss;
- pcb->snd_lbb = iss;
- pcb->tmr = tcp_ticks;
-
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_alloc: tcp_ticks=%"U32_F" iss=%"U32_F"\n", tcp_ticks, iss));
-
- pcb->polltmr = 0;
-
-#if LWIP_CALLBACK_API
- pcb->recv = tcp_recv_null;
-#endif /* LWIP_CALLBACK_API */
-
- /* Init KEEPALIVE timer */
- pcb->keep_idle = TCP_KEEPIDLE_DEFAULT;
-
-#if LWIP_TCP_KEEPALIVE
- pcb->keep_intvl = TCP_KEEPINTVL_DEFAULT;
- pcb->keep_cnt = TCP_KEEPCNT_DEFAULT;
-#endif /* LWIP_TCP_KEEPALIVE */
-
- pcb->keep_cnt_sent = 0;
- }
- return pcb;
-}
-
-/**
- * Creates a new TCP protocol control block but doesn't place it on
- * any of the TCP PCB lists.
- * The pcb is not put on any list until binding using tcp_bind().
- *
- * @internal: Maybe there should be a idle TCP PCB list where these
- * PCBs are put on. Port reservation using tcp_bind() is implemented but
- * allocated pcbs that are not bound can't be killed automatically if wanting
- * to allocate a pcb with higher prio (@see tcp_kill_prio())
- *
- * @return a new tcp_pcb that initially is in state CLOSED
- */
-struct tcp_pcb *
-tcp_new(void)
-{
- return tcp_alloc(TCP_PRIO_NORMAL);
-}
-
-/**
- * Used to specify the argument that should be passed callback
- * functions.
- *
- * @param pcb tcp_pcb to set the callback argument
- * @param arg void pointer argument to pass to callback functions
- */
-void
-tcp_arg(struct tcp_pcb *pcb, void *arg)
-{
- pcb->callback_arg = arg;
-}
-#if LWIP_CALLBACK_API
-
-/**
- * Used to specify the function that should be called when a TCP
- * connection receives data.
- *
- * @param pcb tcp_pcb to set the recv callback
- * @param recv callback function to call for this pcb when data is received
- */
-void
-tcp_recv(struct tcp_pcb *pcb, tcp_recv_fn recv)
-{
- pcb->recv = recv;
-}
-
-/**
- * Used to specify the function that should be called when TCP data
- * has been successfully delivered to the remote host.
- *
- * @param pcb tcp_pcb to set the sent callback
- * @param sent callback function to call for this pcb when data is successfully sent
- */
-void
-tcp_sent(struct tcp_pcb *pcb, tcp_sent_fn sent)
-{
- pcb->sent = sent;
-}
-
-/**
- * Used to specify the function that should be called when a fatal error
- * has occured on the connection.
- *
- * @param pcb tcp_pcb to set the err callback
- * @param err callback function to call for this pcb when a fatal error
- * has occured on the connection
- */
-void
-tcp_err(struct tcp_pcb *pcb, tcp_err_fn err)
-{
- pcb->errf = err;
-}
-
-/**
- * Used for specifying the function that should be called when a
- * LISTENing connection has been connected to another host.
- *
- * @param pcb tcp_pcb to set the accept callback
- * @param accept callback function to call for this pcb when LISTENing
- * connection has been connected to another host
- */
-void
-tcp_accept(struct tcp_pcb *pcb, tcp_accept_fn accept)
-{
- pcb->accept = accept;
-}
-#endif /* LWIP_CALLBACK_API */
-
-
-/**
- * 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, tcp_poll_fn poll, u8_t interval)
-{
-#if LWIP_CALLBACK_API
- pcb->poll = poll;
-#else /* LWIP_CALLBACK_API */
- LWIP_UNUSED_ARG(poll);
-#endif /* LWIP_CALLBACK_API */
- pcb->pollinterval = interval;
-}
-
-/**
- * Purges a TCP PCB. Removes any buffered data and frees the buffer memory
- * (pcb->ooseq, pcb->unsent and pcb->unacked are freed).
- *
- * @param pcb tcp_pcb to purge. The pcb itself is not deallocated!
- */
-void
-tcp_pcb_purge(struct tcp_pcb *pcb)
-{
- if (pcb->state != CLOSED &&
- pcb->state != TIME_WAIT &&
- pcb->state != LISTEN) {
-
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge\n"));
-
-#if TCP_LISTEN_BACKLOG
- if (pcb->state == SYN_RCVD) {
- /* Need to find the corresponding listen_pcb and decrease its accepts_pending */
- struct tcp_pcb_listen *lpcb;
- LWIP_ASSERT("tcp_pcb_purge: pcb->state == SYN_RCVD but tcp_listen_pcbs is NULL",
- tcp_listen_pcbs.listen_pcbs != NULL);
- for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
- if ((lpcb->local_port == pcb->local_port) &&
- (ip_addr_isany(&lpcb->local_ip) ||
- ip_addr_cmp(&pcb->local_ip, &lpcb->local_ip))) {
- /* port and address of the listen pcb match the timed-out pcb */
- LWIP_ASSERT("tcp_pcb_purge: listen pcb does not have accepts pending",
- lpcb->accepts_pending > 0);
- lpcb->accepts_pending--;
- break;
- }
- }
- }
-#endif /* TCP_LISTEN_BACKLOG */
-
-
- if (pcb->refused_data != NULL) {
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->refused_data\n"));
- pbuf_free(pcb->refused_data);
- pcb->refused_data = NULL;
- }
- if (pcb->unsent != NULL) {
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: not all data sent\n"));
- }
- if (pcb->unacked != NULL) {
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->unacked\n"));
- }
-#if TCP_QUEUE_OOSEQ
- if (pcb->ooseq != NULL) {
- LWIP_DEBUGF(TCP_DEBUG, ("tcp_pcb_purge: data left on ->ooseq\n"));
- }
- tcp_segs_free(pcb->ooseq);
- pcb->ooseq = NULL;
-#endif /* TCP_QUEUE_OOSEQ */
-
- /* Stop the retransmission timer as it will expect data on unacked
- queue if it fires */
- pcb->rtime = -1;
-
- tcp_segs_free(pcb->unsent);
- tcp_segs_free(pcb->unacked);
- pcb->unacked = pcb->unsent = NULL;
-#if TCP_OVERSIZE
- pcb->unsent_oversize = 0;
-#endif /* TCP_OVERSIZE */
- }
-}
-
-/**
- * Purges the PCB and removes it from a PCB list. Any delayed ACKs are sent first.
- *
- * @param pcblist PCB list to purge.
- * @param pcb tcp_pcb to purge. The pcb itself is NOT deallocated!
- */
-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);
- }
-
- if (pcb->state != LISTEN) {
- LWIP_ASSERT("unsent segments leaking", pcb->unsent == NULL);
- LWIP_ASSERT("unacked segments leaking", pcb->unacked == NULL);
-#if TCP_QUEUE_OOSEQ
- LWIP_ASSERT("ooseq segments leaking", pcb->ooseq == NULL);
-#endif /* TCP_QUEUE_OOSEQ */
- }
-
- pcb->state = CLOSED;
-
- LWIP_ASSERT("tcp_pcb_remove: tcp_pcbs_sane()", tcp_pcbs_sane());
-}
-
-/**
- * Calculates a new initial sequence number for new connections.
- *
- * @return u32_t pseudo random sequence number
- */
-u32_t
-tcp_next_iss(void)
-{
- static u32_t iss = 6510;
-
- iss += tcp_ticks; /* XXX */
- return iss;
-}
-
-#if TCP_CALCULATE_EFF_SEND_MSS
-/**
- * Calcluates the effective send mss that can be used for a specific IP address
- * by using ip_route to determin the netif used to send to the address and
- * calculating the minimum of TCP_MSS and that netif's mtu (if set).
- */
-u16_t
-tcp_eff_send_mss(u16_t sendmss, ip_addr_t *addr)
-{
- u16_t mss_s;
- struct netif *outif;
-
- outif = ip_route(addr);
- if ((outif != NULL) && (outif->mtu != 0)) {
- mss_s = outif->mtu - IP_HLEN - TCP_HLEN;
- /* RFC 1122, chap 4.2.2.6:
- * Eff.snd.MSS = min(SendMSS+20, MMS_S) - TCPhdrsize - IPoptionsize
- * We correct for TCP options in tcp_write(), and don't support IP options.
- */
- sendmss = LWIP_MIN(sendmss, mss_s);
- }
- return sendmss;
-}
-#endif /* TCP_CALCULATE_EFF_SEND_MSS */
-
-const char*
-tcp_debug_state_str(enum tcp_state s)
-{
- return tcp_state_str[s];
-}
-
-#if TCP_DEBUG || TCP_INPUT_DEBUG || TCP_OUTPUT_DEBUG
-/**
- * Print a tcp header for debugging purposes.
- *
- * @param tcphdr pointer to a struct tcp_hdr
- */
-void
-tcp_debug_print(struct tcp_hdr *tcphdr)
-{
- LWIP_DEBUGF(TCP_DEBUG, ("TCP header:\n"));
- LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
- LWIP_DEBUGF(TCP_DEBUG, ("| %5"U16_F" | %5"U16_F" | (src port, dest port)\n",
- ntohs(tcphdr->src), ntohs(tcphdr->dest)));
- LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
- LWIP_DEBUGF(TCP_DEBUG, ("| %010"U32_F" | (seq no)\n",
- ntohl(tcphdr->seqno)));
- LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
- LWIP_DEBUGF(TCP_DEBUG, ("| %010"U32_F" | (ack no)\n",
- ntohl(tcphdr->ackno)));
- LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
- LWIP_DEBUGF(TCP_DEBUG, ("| %2"U16_F" | |%"U16_F"%"U16_F"%"U16_F"%"U16_F"%"U16_F"%"U16_F"| %5"U16_F" | (hdrlen, flags (",
- TCPH_HDRLEN(tcphdr),
- TCPH_FLAGS(tcphdr) >> 5 & 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,
- ntohs(tcphdr->wnd)));
- tcp_debug_print_flags(TCPH_FLAGS(tcphdr));
- LWIP_DEBUGF(TCP_DEBUG, ("), win)\n"));
- LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
- LWIP_DEBUGF(TCP_DEBUG, ("| 0x%04"X16_F" | %5"U16_F" | (chksum, urgp)\n",
- ntohs(tcphdr->chksum), ntohs(tcphdr->urgp)));
- LWIP_DEBUGF(TCP_DEBUG, ("+-------------------------------+\n"));
-}
-
-/**
- * Print a tcp state for debugging purposes.
- *
- * @param s enum tcp_state to print
- */
-void
-tcp_debug_print_state(enum tcp_state s)
-{
- LWIP_DEBUGF(TCP_DEBUG, ("State: %s\n", tcp_state_str[s]));
-}
-
-/**
- * Print tcp flags for debugging purposes.
- *
- * @param flags tcp flags, all active flags are printed
- */
-void
-tcp_debug_print_flags(u8_t flags)
-{
- if (flags & TCP_FIN) {
- LWIP_DEBUGF(TCP_DEBUG, ("FIN "));
- }
- if (flags & TCP_SYN) {
- LWIP_DEBUGF(TCP_DEBUG, ("SYN "));
- }
- if (flags & TCP_RST) {
- LWIP_DEBUGF(TCP_DEBUG, ("RST "));
- }
- if (flags & TCP_PSH) {
- LWIP_DEBUGF(TCP_DEBUG, ("PSH "));
- }
- if (flags & TCP_ACK) {
- LWIP_DEBUGF(TCP_DEBUG, ("ACK "));
- }
- if (flags & TCP_URG) {
- LWIP_DEBUGF(TCP_DEBUG, ("URG "));
- }
- if (flags & TCP_ECE) {
- LWIP_DEBUGF(TCP_DEBUG, ("ECE "));
- }
- if (flags & TCP_CWR) {
- LWIP_DEBUGF(TCP_DEBUG, ("CWR "));
- }
- LWIP_DEBUGF(TCP_DEBUG, ("\n"));
-}
-
-/**
- * Print all tcp_pcbs in every list for debugging purposes.
- */
-void
-tcp_debug_print_pcbs(void)
-{
- struct tcp_pcb *pcb;
- LWIP_DEBUGF(TCP_DEBUG, ("Active PCB states:\n"));
- for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
- LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
- pcb->local_port, pcb->remote_port,
- pcb->snd_nxt, pcb->rcv_nxt));
- tcp_debug_print_state(pcb->state);
- }
- LWIP_DEBUGF(TCP_DEBUG, ("Listen PCB states:\n"));
- for(pcb = (struct tcp_pcb *)tcp_listen_pcbs.pcbs; pcb != NULL; pcb = pcb->next) {
- LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
- pcb->local_port, pcb->remote_port,
- pcb->snd_nxt, pcb->rcv_nxt));
- tcp_debug_print_state(pcb->state);
- }
- LWIP_DEBUGF(TCP_DEBUG, ("TIME-WAIT PCB states:\n"));
- for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
- LWIP_DEBUGF(TCP_DEBUG, ("Local port %"U16_F", foreign port %"U16_F" snd_nxt %"U32_F" rcv_nxt %"U32_F" ",
- pcb->local_port, pcb->remote_port,
- pcb->snd_nxt, pcb->rcv_nxt));
- tcp_debug_print_state(pcb->state);
- }
-}
-
-/**
- * Check state consistency of the tcp_pcb lists.
- */
-s16_t
-tcp_pcbs_sane(void)
-{
- struct tcp_pcb *pcb;
- for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
- LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != CLOSED", pcb->state != CLOSED);
- LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != LISTEN", pcb->state != LISTEN);
- LWIP_ASSERT("tcp_pcbs_sane: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT);
- }
- for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
- LWIP_ASSERT("tcp_pcbs_sane: tw pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
- }
- return 1;
-}
-#endif /* TCP_DEBUG */
-
-#endif /* LWIP_TCP */