LwIP如何限制TCP服务器只能连接一个客户端
LwIP如何限制TCP服务器只能连接一个客户端？使用tcp调试助手连接服务器，发现使用相同的端口，都能连上(如下图)；但是只有一个是可以用的，请问如何限制tcp客户端数量，下面是我的tcp服务器代码。
static void Tcp_Server_Rs485_2( void *thread_param )
{
err_t err = ERR_OK;
struct netbuf *recvbuf;
void *data = NULL;
uint16_t len = 0;
tcpconn485_2 = netconn_new( NETCONN_TCP );
netconn_bind( tcpconn485_2, IPADDR_ANY, Net_Info.Port );
netconn_listen( tcpconn485_2 );
for( ;; )
{
err = netconn_accept( tcpconn485_2, &newconn485_2 );
if( err == ERR_OK )
{
usart_enable( UART3 );
comClearTxFifo( COM3 );
newconn485_2->recv_timeout = 5;
for( ;; )
{
if( ( err = netconn_recv( newconn485_2, &recvbuf ) ) == ERR_OK )
{
do
{
netbuf_data( recvbuf, &data, &len );
comClearRxFifo( COM3 );
comSendBuf( COM3, data, len );
} while( netbuf_next( recvbuf ) >= 0 );
netbuf_delete( recvbuf );
}
else if( err == ERR_TIMEOUT )
{
if( NetCable_STATUS == 0 )
goto __RS485_SVR2_DESTROY;
}
else
{
__RS485_SVR2_DESTROY:
netbuf_delete( recvbuf );
netconn_close( newconn485_2 );
while( ERR_OK != netconn_delete( newconn485_2 ) )
{
vTaskDelay( 1 );
}
usart_disable( UART3 );
break;
}
}
}
else
{
netbuf_delete( recvbuf );
netconn_close( newconn485_2 );
while( ERR_OK != netconn_delete( newconn485_2 ) )
{
vTaskDelay( 1 );
}
usart_disable( UART3 );
}
}
}
测试图片，图片中新建了5个客户端，都连上了tcp服务器。 TCP是面向对象的一对一连接，你这个可以连接5个说明有对应的配置项，设置除了监听TCP占用一个外，还有5个可以使用。 eric2013 发表于 2023-3-15 09:49
TCP是面向对象的一对一连接，你这个可以连接5个说明有对应的配置项，设置除了监听TCP占用一个外，还有5个可 ...
其实可以连接的不只有5个，还可以连好几个。任务就只有一个，所以只有一个连接能工作，其他的连接，如果发送数据，因为没有释放数据，会卡死。MEMP_NUM_TCP_PCB_LISTEN设为1，也还是能连好多个。
/**
******************************************************************************
* @file lwipopts.h
* @authorMCD Application Team
* @version V1.1.0
* @date 31-July-2013
* @brief lwIP Options Configuration.
* This file is based on Utilities\lwip_v1.4.1\src\include\lwip\opt.h
* and contains the lwIP configuration for the STM32F4x7 demonstration.
******************************************************************************
* @attention
*
* <h2><center>© COPYRIGHT 2013 STMicroelectronics</center></h2>
*
* Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.st.com/software_license_agreement_liberty_v2
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************
*/
#ifndef __LWIPOPTS_H__
#define __LWIPOPTS_H__
/**
* SYS_LIGHTWEIGHT_PROT==1: if you want inter-task protection for certain
* critical regions during buffer allocation, deallocation and memory
* allocation and deallocation.
*/
#define SYS_LIGHTWEIGHT_PROT 1
/**
* NO_SYS==1: Provides VERY minimal functionality. Otherwise,
* use lwIP facilities.
*/
#define NO_SYS 0
/**
* NO_SYS_NO_TIMERS==1: Drop support for sys_timeout when NO_SYS==1
* Mainly for compatibility to old versions.
*/
#define NO_SYS_NO_TIMERS 0
/* ---------- Memory options ---------- */
/* MEM_ALIGNMENT: should be set to the alignment of the CPU for which
lwIP is compiled. 4 byte alignment -> define MEM_ALIGNMENT to 4, 2
byte alignment -> define MEM_ALIGNMENT to 2. */
#define MEM_ALIGNMENT 4
/* MEM_SIZE: the size of the heap memory. If the application will send
a lot of data that needs to be copied, this should be set high. */
#define MEM_SIZE ( 128 * 1024 )
/* MEMP_NUM_PBUF: the number of memp struct pbufs. If the application
sends a lot of data out of ROM (or other static memory), this
should be set high. */
#define MEMP_NUM_PBUF 40
/* MEMP_NUM_UDP_PCB: the number of UDP protocol control blocks. One
per active UDP "connection". */
#define MEMP_NUM_UDP_PCB 20
/* MEMP_NUM_TCP_PCB: the number of simulatenously active TCP
connections. */
#define MEMP_NUM_TCP_PCB 40
/* MEMP_NUM_TCP_PCB_LISTEN: the number of listening TCP
connections. */
#define MEMP_NUM_TCP_PCB_LISTEN 1
/* MEMP_NUM_TCP_SEG: the number of simultaneously queued TCP
segments. */
#define MEMP_NUM_TCP_SEG 40
/* MEMP_NUM_SYS_TIMEOUT: the number of simulateously active
timeouts. */
#define MEMP_NUM_SYS_TIMEOUT 20
/* MEMP_NUM_NETCONN: the number of NETCONN struct. */
#define MEMP_NUM_NETCONN 20
/* MEMP_NUM_NETBUF: the number of struct netbufs.
(only needed if you use the sequential API, like api_lib.c) */
#define MEMP_NUM_NETBUF 40
/* MEMP_MEM_MALLOC: Use mem_malloc/mem_free instead of
the lwip pool allocator. */
#define MEMP_MEM_MALLOC 1
/* MEM_LIBC_MALLOC: Use C Library. */
#define MEM_LIBC_MALLOC 0
/* ---------- Pbuf options ---------- */
/* PBUF_POOL_SIZE: the number of buffers in the pbuf pool. */
#define PBUF_POOL_SIZE 20
/* PBUF_POOL_BUFSIZE: the size of each pbuf in the pbuf pool. */
#define PBUF_POOL_BUFSIZE 1600
/* ---------- TCP options ---------- */
#define LWIP_TCP 1
#define TCP_TTL 255
/* Controls if TCP should queue segments that arrive out of
order. Define to 0 if your device is low on memory. */
#define TCP_QUEUE_OOSEQ 0
/* TCP Maximum segment size. */
#define TCP_MSS (1500 - 40) /* TCP_MSS = (Ethernet MTU - IP header size - TCP header size) */
/* TCP sender buffer space (bytes). */
#define TCP_SND_BUF ( 4 * TCP_MSS )
/*TCP_SND_QUEUELEN: TCP sender buffer space (pbufs). This must be at least
as much as (2 * TCP_SND_BUF/TCP_MSS) for things to work. */
#define TCP_SND_QUEUELEN ( 4 * TCP_SND_BUF / TCP_MSS )
/* TCP receive window. */
#define TCP_WND ( 16 * TCP_MSS )
/* The TCP timer interval in 250 milliseconds. */
#define TCP_TMR_INTERVAL 5
/* LWIP_SO_RCVTIMEO==1: Enable receive timeout for sockets/netconns and SO_RCVTIMEO processing. */
#define LWIP_SO_RCVTIMEO 1
/* LWIP_SO_SNDTIMEO==1: Enable send timeout for sockets/netconns and SO_SNDTIMEO processing. */
#define LWIP_SO_SNDTIMEO 1
/* ---------- ICMP options ---------- */
#define LWIP_ICMP 1
/* ---------- DHCP options ---------- */
/* Define LWIP_DHCP to 1 if you want DHCP configuration of
interfaces. DHCP is not implemented in lwIP 0.5.1, however, so
turning this on does currently not work. */
#define LWIP_DHCP 0
/* ---------- UDP options ---------- */
#define LWIP_UDP 1
#define UDP_TTL 255
/* ---------- Statistics options ---------- */
#define LWIP_STATS 0
#define LWIP_PROVIDE_ERRNO 1
/* ---------- link callback options ---------- */
/* LWIP_NETIF_LINK_CALLBACK==1: Support a callback function from an interface
* whenever the link changes (i.e., link down)
*/
#define LWIP_NETIF_LINK_CALLBACK 1
/*
--------------------------------------
---------- Checksum options ----------
--------------------------------------
*/
/*
The STM32F4x7 allows computing and verifying the IP, UDP, TCP and ICMP checksums by hardware:
- To use this feature let the following define uncommented.
- To disable it and process by CPU comment thethe checksum.
*/
//#define CHECKSUM_BY_HARDWARE
#ifdef CHECKSUM_BY_HARDWARE
/* CHECKSUM_GEN_IP==0: Generate checksums by hardware for outgoing IP packets.*/
#define CHECKSUM_GEN_IP 0
/* CHECKSUM_GEN_UDP==0: Generate checksums by hardware for outgoing UDP packets.*/
#define CHECKSUM_GEN_UDP 0
/* CHECKSUM_GEN_TCP==0: Generate checksums by hardware for outgoing TCP packets.*/
#define CHECKSUM_GEN_TCP 0
/* CHECKSUM_CHECK_IP==0: Check checksums by hardware for incoming IP packets.*/
#define CHECKSUM_CHECK_IP 0
/* CHECKSUM_CHECK_UDP==0: Check checksums by hardware for incoming UDP packets.*/
#define CHECKSUM_CHECK_UDP 0
/* CHECKSUM_CHECK_TCP==0: Check checksums by hardware for incoming TCP packets.*/
#define CHECKSUM_CHECK_TCP 0
/* CHECKSUM_CHECK_ICMP==0: Check checksums by hardware for incoming ICMP packets.*/
#define CHECKSUM_GEN_ICMP 0
#else
/* CHECKSUM_GEN_IP==1: Generate checksums in software for outgoing IP packets.*/
#define CHECKSUM_GEN_IP 1
/* CHECKSUM_GEN_UDP==1: Generate checksums in software for outgoing UDP packets.*/
#define CHECKSUM_GEN_UDP 1
/* CHECKSUM_GEN_TCP==1: Generate checksums in software for outgoing TCP packets.*/
#define CHECKSUM_GEN_TCP 1
/* CHECKSUM_CHECK_IP==1: Check checksums in software for incoming IP packets.*/
#define CHECKSUM_CHECK_IP 1
/* CHECKSUM_CHECK_UDP==1: Check checksums in software for incoming UDP packets.*/
#define CHECKSUM_CHECK_UDP 1
/* CHECKSUM_CHECK_TCP==1: Check checksums in software for incoming TCP packets.*/
#define CHECKSUM_CHECK_TCP 1
/* CHECKSUM_CHECK_ICMP==1: Check checksums by hardware for incoming ICMP packets.*/
#define CHECKSUM_GEN_ICMP 1
#endif
/*
----------------------------------------------
---------- Sequential layer options ----------
----------------------------------------------
*/
/**
* LWIP_NETCONN==1: Enable Netconn API (require to use api_lib.c)
*/
#define LWIP_NETCONN 1
/*
------------------------------------
---------- Socket options ----------
------------------------------------
*/
/**
* LWIP_SOCKET==1: Enable Socket API (require to use sockets.c)
*/
#define LWIP_SOCKET 1
/*
---------------------------------
---------- OS options ----------
---------------------------------
*/
#define DEFAULT_UDP_RECVMBOX_SIZE 20
#define DEFAULT_TCP_RECVMBOX_SIZE 100
#define DEFAULT_ACCEPTMBOX_SIZE 20
#define DEFAULT_THREAD_STACKSIZE 1024
#define TCPIP_THREAD_NAME "lwip"
#define TCPIP_THREAD_STACKSIZE 8192
#define TCPIP_MBOX_SIZE 500
#define TCPIP_THREAD_PRIO 31
//#define IPERF_SERVER_THREAD_NAME "iperf_server"
//#define IPERF_SERVER_THREAD_STACKSIZE 1024
//#define IPERF_SERVER_THREAD_PRIO 0
//#define BLOCK_TIME 250
//#define BLOCK_TIME_WAITING_FOR_INPUT ( ( portTickType ) 100 )
/*
----------------------------------------
---------- Lwip Keep Alive -------------
----------------------------------------
*/
#define LWIP_TCP_KEEPALIVE ( 1 )
#define TCP_KEEPIDLE_DEFAULT ( 3000UL )
#define TCP_KEEPINTVL_DEFAULT ( 1000UL )
#define TCP_KEEPCNT_DEFAULT ( 3UL )
//#define TCP_MAXIDLE ( LWIP_KEEPCNT_DEFAULT * LWIP_KEEPINTVL_DEFAULT )
/*
----------------------------------------
---------- Lwip Debug options ----------
----------------------------------------
*/
//#define LWIP_DEBUG 1
#endif /* __LWIPOPTS_H__ */
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
/*
* Copyright (c) 2001-2003 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>
*
*/
//#ifndef __LWIPOPTS_H__
//#define __LWIPOPTS_H__
//#define TCPIP_MBOX_SIZE 6
//#define TCPIP_THREAD_NAME "tcp/ip"
//#define TCPIP_THREAD_STACKSIZE 1500
//#define TCPIP_THREAD_PRIO 3
//#define DEFAULT_THREAD_STACKSIZE 1500
//#define DEFAULT_THREAD_PRIO 3
//#define ETH_PAD_SIZE 2
//#define LWIP_TCPIP_CORE_LOCKING 0 ///TODO Initialize mutex
////#define LWIP_DEBUG
////#define DBG_TYPES_ON 0xff
//#define ETHARP_DEBUG LWIP_DBG_OFF
//#define NETIF_DEBUG LWIP_DBG_ON
//#define PBUF_DEBUG LWIP_DBG_OFF
//#define API_LIB_DEBUG LWIP_DBG_OFF
//#define API_MSG_DEBUG LWIP_DBG_OFF
//#define SOCKETS_DEBUG LWIP_DBG_OFF
//#define ICMP_DEBUG LWIP_DBG_OFF
//#define IGMP_DEBUG LWIP_DBG_OFF
//#define INET_DEBUG LWIP_DBG_OFF
//#define IP_DEBUG LWIP_DBG_OFF
//#define IP_REASS_DEBUG LWIP_DBG_OFF
//#define RAW_DEBUG LWIP_DBG_OFF
//#define MEM_DEBUG LWIP_DBG_OFF
//#define MEMP_DEBUG LWIP_DBG_OFF
//#define SYS_DEBUG LWIP_DBG_OFF
//#define TCP_DEBUG LWIP_DBG_OFF
//#define TCP_INPUT_DEBUG LWIP_DBG_OFF
//#define TCP_FR_DEBUG LWIP_DBG_OFF
//#define TCP_RTO_DEBUG LWIP_DBG_OFF
//#define TCP_CWND_DEBUG LWIP_DBG_OFF
//#define TCP_WND_DEBUG LWIP_DBG_OFF
//#define TCP_OUTPUT_DEBUG LWIP_DBG_OFF
//#define TCP_RST_DEBUG LWIP_DBG_OFF
//#define TCP_QLEN_DEBUG LWIP_DBG_OFF
//#define UDP_DEBUG LWIP_DBG_OFF
//#define TCPIP_DEBUG LWIP_DBG_OFF
//#define PPP_DEBUG LWIP_DBG_OFF
//#define SLIP_DEBUG LWIP_DBG_OFF
//#define DHCP_DEBUG LWIP_DBG_OFF
//#define AUTOIP_DEBUG LWIP_DBG_OFF
//#define SNMP_MSG_DEBUG LWIP_DBG_OFF
//#define SNMP_MIB_DEBUG LWIP_DBG_OFF
//#define DNS_DEBUG LWIP_DBG_OFF
//#define LWIP_NOASSERT 0
///**
// * SYS_LIGHTWEIGHT_PROT==1: if you want inter-task protection for certain
// * critical regions during buffer allocation, deallocation and memory
// * allocation and deallocation.
// */
//#define SYS_LIGHTWEIGHT_PROT 1
///*
// ------------------------------------
// ---------- Memory options ----------
// ------------------------------------
//*/
///**
// * MEM_ALIGNMENT: should be set to the alignment of the CPU
// * 4 byte alignment -> #define MEM_ALIGNMENT 4
// * 2 byte alignment -> #define MEM_ALIGNMENT 2
// */
//#define MEM_ALIGNMENT 4
///** STF (9*1024)
// * MEM_SIZE: the size of the heap memory. If the application will send
// * a lot of data that needs to be copied, this should be set high.
// */
//#define MEM_SIZE (8*1024)
///*
// ------------------------------------------------
// ---------- Internal Memory Pool Sizes ----------
// ------------------------------------------------
//*/
///** STF 40
// * MEMP_NUM_PBUF: the number of memp struct pbufs (used for PBUF_ROM and PBUF_REF).
// * If the application sends a lot of data out of ROM (or other static memory),
// * this should be set high.
// */
//#define MEMP_NUM_PBUF 20
///** STF 8
// * MEMP_NUM_TCP_PCB: the number of simulatenously active TCP connections.
// * (requires the LWIP_TCP option)
// */
//#define MEMP_NUM_TCP_PCB 10
///**
// * MEMP_NUM_TCP_SEG: the number of simultaneously queued TCP segments.
// * (requires the LWIP_TCP option)
// */
//#define MEMP_NUM_TCP_SEG 8
///** STF 3
// * MEMP_NUM_SYS_TIMEOUT: the number of simulateously active timeouts.
// * (requires NO_SYS==0)
// */
//#define MEMP_NUM_SYS_TIMEOUT 5
///**
// * MEMP_NUM_NETBUF: the number of struct netbufs.
// * (only needed if you use the sequential API, like api_lib.c)
// */
//#define MEMP_NUM_NETBUF 4
///** STF 8
// * PBUF_POOL_SIZE: the number of buffers in the pbuf pool.
// */
//#define PBUF_POOL_SIZE 4
///*
// ----------------------------------
// ---------- Pbuf options ----------
// ----------------------------------
//*/
///**
// * PBUF_POOL_BUFSIZE: the size of each pbuf in the pbuf pool. The default is
// * designed to accomodate single full size TCP frame in one pbuf, including
// * TCP_MSS, IP header, and link header.
// */
//#define PBUF_POOL_BUFSIZE 1500
///*
// ---------------------------------
// ---------- TCP options ----------
// ---------------------------------
//*/
///**
// * LWIP_TCP==1: Turn on TCP.
// */
//#define LWIP_TCP 1
///* TCP Maximum segment size. */
//#define TCP_MSS 1500
///* TCP sender buffer space (bytes). */
//#define TCP_SND_BUF 2*TCP_MSS
///**
// * TCP_WND: The size of a TCP window.
// */
//#define TCP_WND 2*TCP_MSS //1500
///**
// * TCP_SYNMAXRTX: Maximum number of retransmissions of SYN segments.
// */
//#define TCP_SYNMAXRTX 4
///*
// ---------------------------------
// ---------- RAW options ----------
// ---------------------------------
//*/
///**
// * LWIP_RAW==1: Enable application layer to hook into the IP layer itself.
// */
//#define LWIP_RAW 0
///*
// ----------------------------------------------
// ---------- Sequential layer options ----------
// ----------------------------------------------
//*/
///**
// * LWIP_NETCONN==1: Enable Netconn API (require to use api_lib.c)
// */
//#define LWIP_NETCONN 1
///*
// ------------------------------------
// ---------- Socket options ----------
// ------------------------------------
//*/
///**
// * LWIP_SOCKET==1: Enable Socket API (require to use sockets.c)
// */
//#define LWIP_SOCKET 1
///*
// ----------------------------------------
// ---------- Statistics options ----------
// ----------------------------------------
//*/
///**
// * LWIP_STATS==1: Enable statistics collection in lwip_stats.
// */
//#define LWIP_STATS 0
///*
// ----------------------------------
// ---------- DHCP options ----------
// ----------------------------------
//*/
///**
// * LWIP_DHCP==1: Enable DHCP module.
// */
//#define LWIP_DHCP 0
///*
// ----------------------------------
// ---------- IGMP options ----------
// ----------------------------------
//*/
///**
// * LWIP_IGMP==1: Turn on IGMP module.
// */
//#define LWIP_IGMP 0
//#define LWIP_PROVIDE_ERRNO 1
////#define LWIP_SNMP 1
//#endif /* __LWIPOPTS_H__ */
Zachary唷 发表于 2023-3-15 10:00
其实可以连接的不只有5个，还可以连好几个。任务就只有一个，所以只有一个连接能工作，其他的连接，如果 ...
注意监听仅需要一个就行了，除非你新开创建。以BSD Socket为例，用户创建一个Socket就默认开了一个监听，然后就可以对这个Socket创建多个TCP连接，个数是可以配置的，本质上实际是开了多个TCP链接，TCP是一对一的。
从定义来看，TCP应该是这个限制的。lwip配置项真是又乱有多。得把这几个配置项管理捋捋才行
MEMP_NUM_TCP_PCB: the number of simulatenously active TCP connections. 试过了，并没有什么用，焦头烂额中啊 Zachary唷 发表于 2023-3-15 10:09
试过了，并没有什么用，焦头烂额中啊
找不到那个参数起作用，直接关闭监听即可，看看有对应的API设置没，这样就不会有新链接了 eric2013 发表于 2023-3-15 10:24
找不到那个参数起作用，直接关闭监听即可，看看有对应的API设置没，这样就不会有新链接了
唉，找不到相关的API。看代码，监听好像只能开，没有关这一说 Zachary唷 发表于 2023-3-15 11:23
唉，找不到相关的API。看代码，监听好像只能开，没有关这一说
具体LwIP什么鬼不清楚了，自己再研究下吧，这个是我这里的玩法设置，用的BSD Socket
好的，谢谢硬汉，你这个用的是什么协议栈？ Zachary唷 发表于 2023-3-15 13:40
好的，谢谢硬汉，你这个用的是什么协议栈？
这个帖子的BSD Socket例子
https://www.armbbs.cn/forum.php?mod=viewthread&tid=26034 Zachary唷 发表于 2023-3-15 13:40
好的，谢谢硬汉，你这个用的是什么协议栈？
同学，这个问题你解决了没，我遇到一样的症状
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