1 #ifndef UDP_H
2 #define UDP_H
3
4 #ifdef MYLINUX
5
6 #include <unistd.h>
7 #include <arpa/inet.h>
8 #include <sys/types.h> /* See NOTES */
9 #include <sys/socket.h>
10
11 #define SOCKET int
12
13 #else
14 #include <winsock2.h>
15 #endif
16
17 class myudp
18 {
19 private:
20 SOCKET st;//类的内部成员一般是不暴露在外面的
21 public:
22 myudp();
23 ~myudp();
24
25 int socket_send(const char * IP,const char *buf, int len);
26 int socket_recv(char *buf, int len, char * srcIP);
27 int socket_bind(short int port);
28 };
29
30 #endif // UDP_H
1 #include <string.h>
2 #include <stdio.h>
3 #include "udp.h"
4
5 //#define MYLINUX ---- linux 下 makefile文件定义 -DMYLINUX
6
7
8
9
10
11 int myudp::socket_send(const char * IP,const char *buf, int len)
12 {
13
14 st = socket(AF_INET, SOCK_DGRAM, 0);
15 //建立一个socket,第一个参数是指定socket要用哪个协议,AF_INET代表要用TCP/IP协议
16 //第二个参数SOCK_DGRAM意思是要用UDP协议
17 //第三个参数一般默认填0
18 struct sockaddr_in addr;
19 memset(&addr, 0, sizeof(addr));//初始化结构addr
20 addr.sin_family = AF_INET;//代表要使用一个TCP/IP的地址
21 addr.sin_port = htons(8080);//host to net short
22 addr.sin_addr.s_addr = inet_addr(IP);
23 //IP地址解析
24 //unsigned long laddr = inet_addr("192.168.6.200");
25 //unsigned char *p = &laddr;
26 //printf("%u, %u, %u, %u\n", *(p), *(p+1), *(p+2), *(p+3));
27
28 size_t rc = 0;
29
30 //发送udp数据
31 rc = sendto(st,buf,len,0,(struct sockaddr *)&addr,sizeof(addr));
32
33 return rc;
34 }
35
36 int myudp::socket_recv(char *buf, int len, char * srcIP)
37 {
38 struct sockaddr_in sendaddr;//来自发送方的IP地址
39 memset(&sendaddr,0,sizeof(sendaddr));
40
41 #ifdef MYLINUX
42 socklen_t len;
43 #else
44 int addrlen;
45 #endif
46 addrlen = sizeof(sendaddr);
47
48
49 memset(buf,0,len);
50 size_t rc = recvfrom(st,buf,len,0,(struct sockaddr *)&sendaddr,&addrlen);
51 //inet_ntoa(sendaddr.sin_addr);//这个函数是不可重入函数
52 //多线程调用，这个函数会出问题
53 if(srcIP)
54 strcpy(srcIP,inet_ntoa(sendaddr.sin_addr));
55 //printf("%s:\n%s\n", srcIP, buf);
56 return rc;
57 }
58
59 myudp::myudp()
60 {
61 #ifndef MYLINUX
62 //初始化socket
63 DWORD ver;
64 WSADATA wsaData;
65 ver = MAKEWORD(1,1);//在调用WASStartup要告诉windows，我用什么版本的socket
66 WSAStartup(ver, &wsaData);//windows要求，只要用socket，第一步，必须调用这个函数
67 //初始化完成
68 #endif
69
70 st = socket(AF_INET,SOCK_DGRAM,0);//定义一个socket
71
72 }
73
74
75 myudp::~myudp()
76 {
77 #ifdef MYLINUX
78 close(st);
79 #else
80 closesocket(st);//关闭socket
81 WSACleanup();//释放win socket内部的相关资源
82 #endif
83 }
84
85
86 int myudp::socket_bind(short port)
87 {
88 struct sockaddr_in addr;
89 memset(&addr,0,sizeof(addr));//初始化addr
90 addr.sin_family = AF_INET;//代表要使用一个TCP/IP的地址
91 addr.sin_port = htons(port);
92 addr.sin_addr.s_addr = htonl(INADDR_ANY);//作为接收方，不需要指定具体的IP地址，接受的主机是什么IP，我就在什么IP接受数据
93 //addr.sin_addr.s_addr = inet_addr("192.168.2.100");
94
95 return bind(st, (struct sockaddr *)&addr, sizeof(addr)); //将端口号和程序绑定
96 }
1 #include <iostream>
2 #include "udp.h"
3
4 using namespace std;
5
6 int main(int argc, char *args[])
7 {
8 if(argc > 1)
9 {
10 myudp udp;
11 char buf[1024] = {0};
12 while(1)
13 {
14 memset(buf, 0, sizeof(buf));
15 gets(buf);
16 udp.socket_send(args[1],buf, strlen(buf));
17 if (strcmp(buf, "exit") == 0)
18 break;
19 }
20
21 }else
22 {
23 myudp udp;
24 char buf[1024] = {0};
25 if(udp.socket_bind(8080) > -1)
26 {
27 char ip[100] = {0};
28 while(1)
29 {
30 memset(buf, 0, sizeof(buf));
31 memset(ip, 0, sizeof(ip));
32 udp.socket_recv(buf,sizeof(buf), ip);
33 if (strncmp(buf, "exit", 4) == 0)
34 break;
35 cout << ip << endl;
36 cout << buf << endl;
37 }
38 }
39 }
40
41 cout << "over" << endl;
42 return 0;
43 }
