diff options
Diffstat (limited to 'tmk_core/tool/mbed/mbed-sdk/libraries/net/lwip/lwip/core/tcp.c')
| -rw-r--r-- | tmk_core/tool/mbed/mbed-sdk/libraries/net/lwip/lwip/core/tcp.c | 1635 |
1 files changed, 1635 insertions, 0 deletions
diff --git a/tmk_core/tool/mbed/mbed-sdk/libraries/net/lwip/lwip/core/tcp.c b/tmk_core/tool/mbed/mbed-sdk/libraries/net/lwip/lwip/core/tcp.c new file mode 100644 index 0000000000..c629bc4e8a --- /dev/null +++ b/tmk_core/tool/mbed/mbed-sdk/libraries/net/lwip/lwip/core/tcp.c @@ -0,0 +1,1635 @@ +/** + * @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 ** const 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; + if (pcb->local_port != 0) { + 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_VAL if bind failed because the PCB is not in a valid state + * 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_VAL); + +#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 ((pcb->so_options & SOF_REUSEADDR) != 0) { + max_pcb_list = NUM_TCP_PCB_LISTS_NO_TIME_WAIT; + } +#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); + if (pcb->local_port != 0) { + 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 +/* From http://www.iana.org/assignments/port-numbers: + "The Dynamic and/or Private Ports are those from 49152 through 65535" */ +#define TCP_LOCAL_PORT_RANGE_START 0xc000 +#define TCP_LOCAL_PORT_RANGE_END 0xffff +#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 = 0; 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; + u16_t old_local_port; + + LWIP_ERROR("tcp_connect: can only connect 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); + } + + old_local_port = pcb->local_port; + 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- and bound-PCBs, check active- and TIME-WAIT PCBs. */ + for (i = 2; 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 */ + + /* 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; + if (old_local_port != 0) { + 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, *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; + + err = ERR_OK; + + ++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) { + struct tcp_pcb *pcb2; + 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; + pcb = pcb->next; + memp_free(MEMP_TCP_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) { + struct tcp_pcb *pcb2; + 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; + pcb = pcb->next; + memp_free(MEMP_TCP_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; + + 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 */ |