我在 FreeRTOS 下使用 lwIP,IP 服务器在基于 ARM 的设备(Xilinx Zynq-7020)上运行,客户端是 windows。
在服务器端,当我绑定、侦听和接受地址:端口时,客户端可以连接到该地址并从该地址读取/写入。并且程序退出后,闲置一段时间(10s~30s)然后重新启动,它也可以从服务器读/写。Howeber,当我退出客户端并长时间空闲(> 30s)时,我无法再连接到服务器了。在服务器端,它不再接受任何地址。有什么解决办法吗?
服务端代码如下:
void echo_server( void *pvParameters )
{
long lSocket, lClientFd, lAddrLen = sizeof( struct sockaddr_in );
struct sockaddr_in sLocalAddr;
struct sockaddr_in client_addr;
static char dIn[BUF_SIZE];
int ret;
( void ) pvParameters;
int on = 1;
int idle = 60;
int intvl = 15;
int cnt = 3;
/* step 1. create and setopts */
lSocket = lwip_socket(AF_INET, SOCK_STREAM, 0);
if( lSocket >= 0 )
{
lwip_setsockopt(lSocket, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on));
//lwip_setsockopt(lSocket, IPPROTO_TCP, TCP_KEEPIDLE, &idle, sizeof(idle));
//lwip_setsockopt(lSocket, IPPROTO_TCP, TCP_KEEPINTVL, &intvl, sizeof(intvl));
//lwip_setsockopt(lSocket, IPPROTO_TCP, TCP_KEEPCNT, &cnt, sizeof(cnt));
memset((char *)&sLocalAddr, 0, sizeof(sLocalAddr));
// prepare bind on port
sLocalAddr.sin_family = AF_INET;
sLocalAddr.sin_len = sizeof(sLocalAddr);
sLocalAddr.sin_addr.s_addr = htonl(INADDR_ANY);
sLocalAddr.sin_port = ntohs( ( ( unsigned short ) ECHO_PORT ) );
/* step 2. bind */
if( lwip_bind( lSocket, ( struct sockaddr *) &sLocalAddr, sizeof( sLocalAddr ) ) < 0 )
{
lwip_close( lSocket );
vTaskDelete( NULL );
}
/* step 3. listen */
if( lwip_listen( lSocket, BACKLOG ) != 0 )
{
lwip_close( lSocket );
vTaskDelete( NULL );
}
for( ;; )
{
/* step 4. accept */
xil_printf("(ZYNQ-ECH) wait connection\n");
lClientFd = lwip_accept(lSocket, ( struct sockaddr * ) &client_addr, ( u32_t * ) &lAddrLen );
xil_printf("(ZYNQ-ECH) accept connection\n");
lwip_setsockopt(lClientFd, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on));
//lwip_setsockopt(lClientFd, IPPROTO_TCP, TCP_KEEPIDLE, &idle, sizeof(idle));
//lwip_setsockopt(lClientFd, IPPROTO_TCP, TCP_KEEPINTVL, &intvl, sizeof(intvl));
//lwip_setsockopt(lClientFd, IPPROTO_TCP, TCP_KEEPCNT, &cnt, sizeof(cnt));
// if client socket created
if( lClientFd > 0L )
{
int packet = 0;
while(1)
{
ret = mfeit_read(lClientFd, dIn);
if (ret == -1 || ret == 0)
break;
ret = mfeit_write( lClientFd, dIn, ret );
if (ret == -1 || ret == 0)
break;
packet ++;
}
xil_printf("(ZYNQ-ECH) close connection, total = %d\n", packet);
lwip_close( lClientFd );
}
}
}
/* Will only get here if a listening socket could not be created. */
xil_printf("(ZYNQ-ECH) task killed !!\n");
vTaskDelete( NULL );
}