LwIP无法获取host

发布于 2010-09-02 22:46:34 浏览：10664 订阅该版

调用这个函数不成功.
```
rt_bool_t tcp_client(char* send_data, char* recv_data)
{
   int port;
   struct hostent *host;
   int sock, bytes_received;
   struct sockaddr_in server_addr;
   const char* url="192.168.1.2";

/* 通过函数入口参数url获得host地址（如果是域名，会做域名解析） */
   port = 80;   
   host = gethostbyname(url);

/* 分配用于存放接收数据的缓冲 */
   if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)
   {       
       rt_kprintf("Socket errorn");       
       
       return RT_FALSE;
   }

/* 初始化预连接的服务端地址 */
   server_addr.sin_family = AF_INET;
   server_addr.sin_port = htons(port);
   server_addr.sin_addr = *((struct in_addr *)host->h_addr);
   rt_memset(&(server_addr.sin_zero), 0, sizeof(server_addr.sin_zero));

/* 连接到服务端 */
   if (connect(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) == -1)
   {
       /* 连接失败 */
       rt_kprintf("Connect errorn");
       
       return RT_FALSE;
   }

while(1)
   {
       /* 从sock连接中接收最大1024字节数据 */
       bytes_received = recv(sock, recv_data, 1024, 0);
       if (bytes_received < 0)
       {
           /* 接收失败，关闭这个连接 */
           lwip_close(sock);
           
           return RT_FALSE;
       }

/* 鏈夋帴鏀跺埌鏁版嵁锛屾妸鏈??娓呴浂 */
       recv_data[bytes_received] = '�';

if (strcmp(recv_data , "q") == 0 || strcmp(recv_data , "Q") == 0)
       {
           /* 有接收到数据，把末端清零 */
           lwip_close(sock);
           
           break;
       }

/* 发送数据到sock连接 */
       send(sock,send_data,strlen(send_data), 0);
   }

return RT_TRUE;
}
```

主要是gethostbyname这个函数通不过.
应当没有抓到包吧.第一次用WiresharkPortable,还不会看.呵呵
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11 个回答

Gavin_Li 2010-09-02

这家伙很懒，什么也没写！

mbbill 2010-09-03

这家伙很懒，什么也没写！

Gavin_Li 2010-09-03

这家伙很懒，什么也没写！

bernard 2010-09-03

这家伙很懒，什么也没写！

Gavin_Li 2010-09-03

这家伙很懒，什么也没写！

Gavin_Li 2010-09-04

这家伙很懒，什么也没写！

今天用FinSH试了UDPClient,发现可以发数据出去.
但是如果放到GUI线程去执行UDPClient,则不能发数据出去.同样是无法获取到host.我怀疑是GUI和LwIP有资源方面的冲突.
测试代码如下:

```

#include "demo_view.h"
#include <rtgui/rtgui_system.h>	
#include <rtgui/widgets/button.h>

static void TCP_Client(struct rtgui_widget* widget, rtgui_event_t* event)
{
   tcpclient("192.168.1.2",80);	
   /*tcpclient("http://192.168.1.2/default.html",80);
   tcpclient("192.168.1.2",139);*/
}

static void UDP_Client(struct rtgui_widget* widget, rtgui_event_t* event)
{
   udpclient("192.168.1.2",138,2);	
}

static void TCP_Server(struct rtgui_widget* widget, rtgui_event_t* event)
{  
   tcpserv(RT_NULL);	
}

static void UDP_Server(struct rtgui_widget* widget, rtgui_event_t* event)
{
   udpserv(RT_NULL);	
}

rtgui_view_t *test_lwip(rtgui_workbench_t* workbench)
{ 
   rtgui_view_t *view1;
   rtgui_button_t *button;    
   rtgui_rect_t widget_rect;

view1 = demo_view(workbench, "test"); 
   
   demo_view_get_rect(view1, &widget_rect);
   widget_rect.x1 = 5;
   widget_rect.x2 = widget_rect.x1 + 50;
   widget_rect.y1 = 170;
   widget_rect.y2 = widget_rect.y1 + 20;
   
   button = rtgui_button_create("TCPClient");
   rtgui_widget_set_rect(RTGUI_WIDGET(button), &widget_rect);
   rtgui_container_add_child(RTGUI_CONTAINER(view1), RTGUI_WIDGET(button));
   rtgui_button_set_onbutton(button, TCP_Client);

widget_rect.x1 = widget_rect.x2 + 10;
   widget_rect.x2 += 50;
   
   button = rtgui_button_create("UDPClient");
   rtgui_widget_set_rect(RTGUI_WIDGET(button), &widget_rect);
   rtgui_container_add_child(RTGUI_CONTAINER(view1), RTGUI_WIDGET(button));
   rtgui_button_set_onbutton(button, UDP_Client); 
   
   widget_rect.x1 = widget_rect.x2 + 10;
   widget_rect.x2 += 50;
   
   button = rtgui_button_create("TCPServer");
   rtgui_widget_set_rect(RTGUI_WIDGET(button), &widget_rect);
   rtgui_container_add_child(RTGUI_CONTAINER(view1), RTGUI_WIDGET(button));
   rtgui_button_set_onbutton(button, TCP_Server);  
   
    widget_rect.x1 = widget_rect.x2 + 10;
   widget_rect.x2 += 50;
   
   button = rtgui_button_create("UDPServer");
   rtgui_widget_set_rect(RTGUI_WIDGET(button), &widget_rect);
   rtgui_container_add_child(RTGUI_CONTAINER(view1), RTGUI_WIDGET(button));
   rtgui_button_set_onbutton(button, UDP_Server);

return view1;
}

```