利用ZYNQ SOC快速打开算法验证通路（6）——LWIP实现千兆TCP/IP网络传输

时间 2019-11-29

标签利用 zynq soc 快速打开算法验证通路 lwip 实现千兆 tcp 网络传输栏目系统网络繁體版

原文原文链接

1、前言web

　　以前ZYNQ与PC之间的网络链接依赖于外接硬件协议栈芯片，虽然C驱动很是简单，但网络带宽受限。现采用LWIP+PS端MAC控制器+PHY芯片的通用架构。关于LWIP库，已经有不少现成的资料和书籍。其有两套API，一个是SOCKET，另外一个是本例中要用到的RAW。RAW API理解起来较为复杂，整个程序基于中断机制运行，经过函数指针完成多层回调函数的执行。SOCKET API须要支持多线程操做系统的支持，也牺牲了效率，但理解和编程都较为容易。实际上SOCKET API是对RAW API的进一步封装。编程

2、LWIP Echo Server demo解读数组

　　首先打开Xilinx SDK自带的LwIP Echo Server demo.服务器

 1 /******************************************************************************  2 *  3 * Copyright (C) 2009 - 2014 Xilinx, Inc. All rights reserved.  4 *  5 * Permission is hereby granted, free of charge, to any person obtaining a copy  6 * of this software and associated documentation files (the "Software"), to deal  7 * in the Software without restriction, including without limitation the rights  8 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell  9 * copies of the Software, and to permit persons to whom the Software is  10 * furnished to do so, subject to the following conditions:  11 *  12 * The above copyright notice and this permission notice shall be included in  13 * all copies or substantial portions of the Software.  14 *  15 * Use of the Software is limited solely to applications:  16 * (a) running on a Xilinx device, or  17 * (b) that interact with a Xilinx device through a bus or interconnect.  18 *  19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR  20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,  21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL  22 * XILINX BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,  23 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF  24 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE  25 * SOFTWARE.  26 *  27 * Except as contained in this notice, the name of the Xilinx shall not be used  28 * in advertising or otherwise to promote the sale, use or other dealings in  29 * this Software without prior written authorization from Xilinx.  30 *  31 ******************************************************************************/
 32 
 33 #include <stdio.h>
 34 
 35 #include "xparameters.h"
 36 
 37 #include "netif/xadapter.h"
 38 
 39 #include "platform.h"
 40 #include "platform_config.h"
 41 #if defined (__arm__) || defined(__aarch64__)
 42 #include "xil_printf.h"
 43 #endif
 44 
 45 #include "lwip/tcp.h"
 46 #include "xil_cache.h"
 47 
 48 #if LWIP_DHCP==1
 49 #include "lwip/dhcp.h"
 50 #endif
 51 
 52 /* defined by each RAW mode application */
 53 void print_app_header();  54 int start_application();  55 int transfer_data();  56 void tcp_fasttmr(void);  57 void tcp_slowtmr(void);  58 
 59 /* missing declaration in lwIP */
 60 void lwip_init();  61 
 62 #if LWIP_DHCP==1
 63 extern volatile int dhcp_timoutcntr;  64 err_t dhcp_start(struct netif *netif);  65 #endif
 66 
 67 extern volatile int TcpFastTmrFlag;  68 extern volatile int TcpSlowTmrFlag;  69 static struct netif server_netif;  70 struct netif *echo_netif;  71 
 72 void
 73 print_ip(char *msg, struct ip_addr *ip)  74 {  75  print(msg);  76     xil_printf("%d.%d.%d.%d\n\r", ip4_addr1(ip), ip4_addr2(ip),  77  ip4_addr3(ip), ip4_addr4(ip));  78 }  79 
 80 void
 81 print_ip_settings(struct ip_addr *ip, struct ip_addr *mask, struct ip_addr *gw)  82 {  83 
 84     print_ip("Board IP: ", ip);  85     print_ip("Netmask : ", mask);  86     print_ip("Gateway : ", gw);  87 }  88 
 89 #if defined (__arm__) && !defined (ARMR5)
 90 #if XPAR_GIGE_PCS_PMA_SGMII_CORE_PRESENT == 1 || XPAR_GIGE_PCS_PMA_1000BASEX_CORE_PRESENT == 1
 91 int ProgramSi5324(void);  92 int ProgramSfpPhy(void);  93 #endif
 94 #endif
 95 
 96 #ifdef XPS_BOARD_ZCU102  97 #ifdef XPAR_XIICPS_0_DEVICE_ID  98 int IicPhyReset(void);  99 #endif
100 #endif
101 
102 int main() 103 { 104     struct ip_addr ipaddr, netmask, gw; 105 
106     /* the mac address of the board. this should be unique per board */
107     unsigned char mac_ethernet_address[] =
108     { 0x00, 0x0a, 0x35, 0x00, 0x01, 0x02 }; 109 
110     echo_netif = &server_netif; 111 #if defined (__arm__) && !defined (ARMR5)
112 #if XPAR_GIGE_PCS_PMA_SGMII_CORE_PRESENT == 1 || XPAR_GIGE_PCS_PMA_1000BASEX_CORE_PRESENT == 1
113  ProgramSi5324(); 114  ProgramSfpPhy(); 115 #endif
116 #endif
117 
118 /* Define this board specific macro in order perform PHY reset on ZCU102 */
119 #ifdef XPS_BOARD_ZCU102 120  IicPhyReset(); 121 #endif
122 
123  init_platform(); 124 
125 #if LWIP_DHCP==1
126     ipaddr.addr = 0; 127     gw.addr = 0; 128     netmask.addr = 0; 129 #else
130     /* initliaze IP addresses to be used */
131     IP4_ADDR(&ipaddr,  192, 168,   1, 10); 132     IP4_ADDR(&netmask, 255, 255, 255,  0); 133     IP4_ADDR(&gw,      192, 168,   1,  1); 134 #endif    
135  print_app_header(); 136 
137     lwip_init();//网络参数初始化
138 
139       /* Add network interface to the netif_list, and set it as default */
140     if (!xemac_add(echo_netif, &ipaddr, &netmask, 141                         &gw, mac_ethernet_address, 142  PLATFORM_EMAC_BASEADDR)) { 143         xil_printf("Error adding N/W interface\n\r"); 144         return -1; 145  } 146  netif_set_default(echo_netif); 147 
148     /* now enable interrupts */
149  platform_enable_interrupts(); 150 
151     /* specify that the network if is up */
152  netif_set_up(echo_netif); 153 
154 #if (LWIP_DHCP==1)
155     /* Create a new DHCP client for this interface. 156  * Note: you must call dhcp_fine_tmr() and dhcp_coarse_tmr() at 157  * the predefined regular intervals after starting the client. 158      */
159  dhcp_start(echo_netif); 160     dhcp_timoutcntr = 24; 161 
162     while(((echo_netif->ip_addr.addr) == 0) && (dhcp_timoutcntr > 0)) 163  xemacif_input(echo_netif); 164 
165     if (dhcp_timoutcntr <= 0) { 166         if ((echo_netif->ip_addr.addr) == 0) { 167             xil_printf("DHCP Timeout\r\n"); 168             xil_printf("Configuring default IP of 192.168.1.10\r\n"); 169             IP4_ADDR(&(echo_netif->ip_addr),  192, 168,   1, 10); 170             IP4_ADDR(&(echo_netif->netmask), 255, 255, 255,  0); 171             IP4_ADDR(&(echo_netif->gw),      192, 168,   1,  1); 172  } 173  } 174 
175     ipaddr.addr = echo_netif->ip_addr.addr; 176     gw.addr = echo_netif->gw.addr; 177     netmask.addr = echo_netif->netmask.addr; 178 #endif
179 
180     print_ip_settings(&ipaddr, &netmask, &gw);//打印关键网络参数
181 
182     /* start the application (web server, rxtest, txtest, etc..) */
183     start_application();//设置回调函数，这些函数在特定事件发生时以函数指针的方式被调用
184 
185     /* receive and process packets */
186     while (1) { 187         if (TcpFastTmrFlag) {//发送处理，如差错重传，经过定时器置位标志位
188  tcp_fasttmr(); 189             TcpFastTmrFlag = 0; 190  } 191         if (TcpSlowTmrFlag) { 192  tcp_slowtmr(); 193             TcpSlowTmrFlag = 0; 194  } 195         xemacif_input(echo_netif);//连续接收数据包，并将数据包存入LWIP
196         transfer_data();//空函数
197  } 198   
199     /* never reached */
200  cleanup_platform(); 201 
202     return 0; 203 }

echo

　　总体流程为：初始化LWIP、添加网络接口（MAC）、使能中断、设置回调函数。最终进入主循环，内部不断检测定时器中断标志位，当标志位TcpFastTmrFlag或TcpSlowTmrFlag为1则调用相应的处理函数，完成超时重传等任务。接下来查看回调函数的设置：网络

int start_application() { struct tcp_pcb *pcb;//protocol control block 简称PCB
 err_t err; unsigned port = 7; /* create new TCP PCB structure */ pcb = tcp_new(); if (!pcb) { xil_printf("Error creating PCB. Out of Memory\n\r"); return -1; } /* bind to specified @port */ err = tcp_bind(pcb, IP_ADDR_ANY, port); if (err != ERR_OK) { xil_printf("Unable to bind to port %d: err = %d\n\r", port, err); return -2; } /* we do not need any arguments to callback functions */ tcp_arg(pcb, NULL); /* listen for connections */ pcb = tcp_listen(pcb); if (!pcb) { xil_printf("Out of memory while tcp_listen\n\r"); return -3; } /* specify callback to use for incoming connections */ tcp_accept(pcb, accept_callback); xil_printf("TCP echo server started @ port %d\n\r", port); return 0; }

start_application

　　建立PCB（protocol control block）创建链接、绑定IP地址和端口号、监听请求，最后tcp_accept函数用于指定当监听到链接请求时调用的函数accept_callback。进入该函数内部查看：多线程

 1 err_t accept_callback(void *arg, struct tcp_pcb *newpcb, err_t err)  2 {  3     static int connection = 1;  4 
 5     /* set the receive callback for this connection */
 6  tcp_recv(newpcb, recv_callback);  7 
 8     /* just use an integer number indicating the connection id as the  9  callback argument */
10     tcp_arg(newpcb, (void*)(UINTPTR)connection); 11 
12     /* increment for subsequent accepted connections */
13     connection++; 14 
15     return ERR_OK; 16 }

accept_callback

　　内部主要经过tcp_recv函数来指定当收到TCP包后调用的函数recv_callback。咱们再次观察其内容：架构

 1 err_t recv_callback(void *arg, struct tcp_pcb *tpcb,  2                                struct pbuf *p, err_t err)  3 {  4     /* do not read the packet if we are not in ESTABLISHED state */
 5     if (!p) {  6  tcp_close(tpcb);  7  tcp_recv(tpcb, NULL);  8         return ERR_OK;  9  } 10 
11     /* indicate that the packet has been received */
12     tcp_recved(tpcb, p->len); 13 
14     /* echo back the payload */
15     /* in this case, we assume that the payload is < TCP_SND_BUF */
16     if (tcp_sndbuf(tpcb) > p->len) { 17         err = tcp_write(tpcb, p->payload, p->len, 1); 18     } else
19         xil_printf("no space in tcp_sndbuf\n\r"); 20 
21     /* free the received pbuf */
22  pbuf_free(p); 23 
24     return ERR_OK; 25 }

recv_callback

　　tcp_recved函数指示用来告知LWIP接收数据量，而后检测发送缓冲区是否足够容纳接收内容，若大于则调用tcp_write函数将接收数据写入发送缓冲区等待发送。综上，总体的调用流程为：tcp_accept -> accept_callback -> tcp_recv -> recv_callback -> tcp_recved和tcp_write。前四个用于接收，后两个用于发送。app

　　函数解析完毕，以后改动上位机网络参数，使PC机IP地址与Board在同一网段内，这里设置为192.168.1.11.打开网络调试助手，设置PC为TCP Client。如下是ZYNQ串口打印及网络调试结果。 tcp

3、TCP Client Send dataide

　　如今咱们来改动demo，设计一个客户端发送数据包的示例工程，功能是循环发送一个常数数组中数据到远程服务器。该工程参考米联客教程中相关章节内容。代码以下：

/******************************************************************************
*
* Copyright (C) 2009 - 2014 Xilinx, Inc.  All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* Use of the Software is limited solely to applications:
* (a) running on a Xilinx device, or
* (b) that interact with a Xilinx device through a bus or interconnect.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* XILINX  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
* OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* Except as contained in this notice, the name of the Xilinx shall not be used
* in advertising or otherwise to promote the sale, use or other dealings in
* this Software without prior written authorization from Xilinx.
*
******************************************************************************/

#include <stdio.h>

#include "xparameters.h"

#include "netif/xadapter.h"

#include "platform.h"
#include "platform_config.h"
#if defined (__arm__) || defined(__aarch64__)
#include "xil_printf.h"
#endif

#include "lwip/tcp.h"
#include "xil_cache.h"

#if LWIP_DHCP==1
#include "lwip/dhcp.h"
#endif

/* defined by each RAW mode application */
void print_app_header();
int client_application();
//int start_application();
//int transfer_data();
int send_data();
void tcp_fasttmr(void);
void tcp_slowtmr(void);

/* missing declaration in lwIP */
void lwip_init();

#if LWIP_DHCP==1
extern volatile int dhcp_timoutcntr;
err_t dhcp_start(struct netif *netif);
#endif

extern volatile int TcpFastTmrFlag;
extern volatile int TcpSlowTmrFlag;
static struct netif server_netif;
struct netif *echo_netif;

void
print_ip(char *msg, struct ip_addr *ip) 
{
    print(msg);
    xil_printf("%d.%d.%d.%d\n\r", ip4_addr1(ip), ip4_addr2(ip), 
            ip4_addr3(ip), ip4_addr4(ip));
}

void
print_ip_settings(struct ip_addr *ip, struct ip_addr *mask, struct ip_addr *gw)
{

    print_ip("Board IP: ", ip);
    print_ip("Netmask : ", mask);
    print_ip("Gateway : ", gw);
}


int main()
{
    uint cycle = 0;
    struct ip_addr ipaddr, netmask, gw;

    /* the mac address of the board. this should be unique per board */
    unsigned char mac_ethernet_address[] =
    { 0x00, 0x0a, 0x35, 0x00, 0x01, 0x02 };

    echo_netif = &server_netif;

/* Define this board specific macro in order perform PHY reset on ZCU102 */


    init_platform();

    /* initliaze IP addresses to be used */
    IP4_ADDR(&ipaddr,  192, 168,   1, 10);
    IP4_ADDR(&netmask, 255, 255, 255,  0);
    IP4_ADDR(&gw,      192, 168,   1,  1);

    print_app_header();

    lwip_init();

      /* Add network interface to the netif_list, and set it as default */
    if (!xemac_add(echo_netif, &ipaddr, &netmask,
                        &gw, mac_ethernet_address,
                        PLATFORM_EMAC_BASEADDR)) {
        xil_printf("Error adding N/W interface\n\r");
        return -1;
    }
    netif_set_default(echo_netif);

    /* now enable interrupts */
    platform_enable_interrupts();

    /* specify that the network if is up */
    netif_set_up(echo_netif);

    print_ip_settings(&ipaddr, &netmask, &gw);

    /* start the application (web server, rxtest, txtest, etc..) */
    //start_application();
    client_application();

    /* receive and process packets */
    while (1) {
        if (TcpFastTmrFlag) {
            tcp_fasttmr();
            TcpFastTmrFlag = 0;
        }
        if (TcpSlowTmrFlag) {
            tcp_slowtmr();
            TcpSlowTmrFlag = 0;
        }
        xemacif_input(echo_netif);
        //transfer_data();
        if(cycle == 9999){
            cycle = 0;
            send_data();
        }
        else
            cycle++;
    }
  

    return 0;
}

main

　　函数定义：

  1 /*
  2  * tcp_trans.c
  3  *
  4  *  Created on: 2018年10月18日
  5  *      Author: s
  6  */
  7 
  8 
  9 #include <stdio.h>
 10 #include <string.h>
 11 
 12 #include "lwip/err.h"
 13 #include "lwip/tcp.h"
 14 #include "lwipopts.h"
 15 #include "xil_cache.h"
 16 #include "xil_printf.h"
 17 #include "sleep.h"
 18 
 19 #define TX_SIZE 10
 20 
 21 static struct tcp_pcb*connected_pcb = NULL;
 22 unsigned client_connected = 0;
 23 //静态全局函数 外部文件不可见
 24 uint tcp_trans_done = 0;
 25 
 26 u_char data[TX_SIZE] = {0,1,2,3,4,5,6,7,8,9};
 27 
 28 int send_data()
 29 {
 30     err_t err;
 31     struct tcp_pcb *tpcb = connected_pcb;
 32 
 33     if (!tpcb)
 34         return -1;
 35 
 36     //判断发送数据长度是否小于发送缓冲区剩余可用长度
 37     if (TX_SIZE < tcp_sndbuf(tpcb)) {
 38         //Write data for sending (but does not send it immediately).
 39         err = tcp_write(tpcb, data, TX_SIZE, 1);
 40         if (err != ERR_OK) {
 41             xil_printf("txperf: Error on tcp_write: %d\r\n", err);
 42             connected_pcb = NULL;
 43             return -1;
 44         }
 45 
 46         //Find out what we can send and send it
 47         err = tcp_output(tpcb);
 48         if (err != ERR_OK) {
 49             xil_printf("txperf: Error on tcp_output: %d\r\n",err);
 50             return -1;
 51         }
 52     }
 53     else
 54         xil_printf("no space in tcp_sndbuf\n\r");
 55 
 56     return 0;
 57 }
 58 
 59 static err_t tcp_sent_callback(void *arg, struct tcp_pcb *tpcb,u16_t len)
 60 {
 61     tcp_trans_done ++;
 62     return ERR_OK;
 63 }
 64 
 65 //tcp链接回调函数 设置为静态函数，外部文件不可见
 66 static err_t tcp_connected_callback(void *arg, struct tcp_pcb *tpcb, err_t err)
 67 {
 68     /* store state */
 69     connected_pcb = tpcb;
 70 
 71     /* set callback values & functions */
 72     tcp_arg(tpcb, NULL);
 73 
 74     //发送到远程主机后调用tcp_sent_callback
 75     tcp_sent(tpcb, tcp_sent_callback);
 76 
 77     client_connected = 1;
 78 
 79     /* initiate data transfer */
 80     return ERR_OK;
 81 }
 82 
 83 int client_application()
 84 {
 85     struct tcp_pcb *pcb;
 86     struct ip_addr ipaddr;
 87     err_t err;
 88     unsigned port = 7;
 89 
 90     /* create new TCP PCB structure */
 91     pcb = tcp_new();
 92     if (!pcb) {
 93         xil_printf("Error creating PCB. Out of Memory\n\r");
 94         return -1;
 95     }
 96 
 97     /* connect to iperf tcp server */
 98     IP4_ADDR(&ipaddr,  192, 168,   1, 209);//设置要链接的主机的地址
 99 
100     //当链接到主机时，调用tcp_connected_callback
101     err = tcp_connect(pcb, &ipaddr, port, tcp_connected_callback);
102     if (err != ERR_OK) {
103         xil_printf("txperf: tcp_connect returned error: %d\r\n", err);
104         return err;
105     }
106 
107     return 0;
108 }

tcp_trans

　　能够看出仍是同样的套路，在client_application函数中设置回调函数。首先新建PCB，tcp_connect函数设定要链接远程服务器的IP地址和端口号，链接创建时将调用回调函数tcp_connected_callback。tcp_connected_callback内部tcp_sent函数用于指定当发送数据包完成后执行的tcp_sent_callback。tcp_sent_callback内部只利用tcp_trans_done变量计数发送次数。而真正的发送处理任务则交给主循环中的send_data。若处于链接状态，且发送缓冲区容量比带发送数据量大，则调用tcp_write将待发送数据写入发送缓冲区，以后调用tcp_output函数当即传输发送缓冲区内容。若是不调用tcp_output，LWIP会等待数据量达到必定值时一块儿发送来提升效率，是否调用tcp_output函数可根据具体需求而定。

　　接下来看下实验结果：

　　PC端正确接收到常数数组，实验无误。

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

参考文献：

1 LWIP 无OS RAW-API 函数 - 专一的力量 - CSDN博客 https://blog.csdn.net/liang890319/article/details/8574603

2 解读TCP 四种定时器 - xiaofei0859的专栏 - CSDN博客 https://blog.csdn.net/xiaofei0859/article/details/52794576

3 米联《ZYNQ SOC修炼秘籍》