UDP服务器/客户端代码示例

UDP服务器代码：

 1 #include <errno.h>
 2 #include <string.h>
 3 #include <stdlib.h>
 4 #include <sys/types.h>
 5 #include <sys/socket.h>
 6 #include <netinet/in.h>
 7 #include <arpa/inet.h>
 8 #include <iostream>
 9
10 using namespace std;
11
12 int main(int argc, char *argv[])
13 {
14     if (argc != 3)
15     {
16         cout << "usage: " << argv[0] << " ip port" << endl;
17         return -1;
18     }
19
20     char *szIp = argv[1];
21     in_addr_t iIp = inet_addr(szIp);
22     if (iIp == INADDR_NONE)
23     {
24         cerr << "fail to parse ip: " << szIp << endl;
25         return -1;
26     }
27     char *pEnd = NULL;
28     uint16_t usPort = strtoul(argv[2], &pEnd, 10);
29     if (*pEnd != ‘\0‘)
30     {
31         cerr << "fail to parse port: " << argv[2] << endl;
32         return -1;
33     }
34
35     int iSockFd = socket(AF_INET, SOCK_DGRAM, 0);
36     if (iSockFd < 0)
37     {
38         cerr << "fail to create socket, err: " << strerror(errno) << endl;
39         return -1;
40     }
41     cout << "create socket fd " << iSockFd << endl;
42
43     sockaddr_in oAddr;
44     memset(&oAddr, 0, sizeof(oAddr));
45     oAddr.sin_family = AF_INET;
46     oAddr.sin_addr.s_addr = iIp;
47     oAddr.sin_port = htons(usPort);
48     if (bind(iSockFd, (sockaddr *)&oAddr, sizeof(oAddr)) < 0)
49     {
50         cerr << "fail to bind addr " << szIp << ":" << usPort << ", err: " << strerror(errno) << endl;
51         return -1;
52     }
53     cout << "bind addr " << szIp << ":" >> usPort << endl;
54
55     uint8_t acRecvBuf[64 * 1024];
56     while (true)
57     {
58         sockaddr_in oClientAddr;
59         socklen_t iAddrLen = sizeof(oClientAddr);
60         ssize_t iRecvLen = recvfrom(iSockFd, acRecvBuf, sizeof(acRecvBuf), 0, (sockaddr *)&oClientAddr, &iAddrLen);
61         if (iRecvLen < 0)
62         {
63             cerr << "fail to recv, err: " << strerror(errno) << endl;
64             continue;
65         }
66         cout << "recv data from " << inet_ntoa(oClientAddr.sin_addr) << ":" << ntohs(oClientAddr.sin_port) << ", len: " << iRecvLen << endl;
67
68         ssize_t iSendLen = sendto(iSockFd, acRecvBuf, iRecvLen, 0, (sockaddr *)&oClientAddr, iAddrLen);
69         if (iSendLen < 0)
70         {
71             cerr << "fail to send, err: " << strerror(errno) << endl;
72             continue;
73         }
74         cout << "echo to client, len: " << iSendLen << endl;
75     }
76
77     return 0;
78 }

UDP客户端代码：

 1 #include <errno.h>
 2 #include <string.h>
 3 #include <sys/types.h>
 4 #include <sys/socket.h>
 5 #include <netinet/in.h>
 6 #include <arpa/inet.h>
 7 #include <stdlib.h>
 8 #include <iostream>
 9
10 using namespace std;
11
12 int main(int argc, char *argv[])
13 {
14     if (argc != 4)
15     {
16         cout << "usage: " << argv[0] << " ip port message" << endl;
17         return -1;
18     }
19
20     char *szIp = argv[1];
21     in_addr_t iIp = inet_addr(szIp);
22     if (iIp == INADDR_NONE)
23     {
24         cerr << "fail to parse ip: " << szIp << endl;
25         return -1;
26     }
27     char *pEnd = NULL;
28     uint16_t usPort = strtoul(argv[2], &pEnd, 10);
29     if (*pEnd != ‘\0‘)
30     {
31         cerr << "fail to parse port: " << argv[2] << endl;
32         return -1;
33     }
34     char *szMsg = argv[3];
35     size_t uiMsgLen = strlen(szMsg);
36
37     int iSockFd = socket(AF_INET, SOCK_DGRAM, 0);
38     if (iSockFd < 0)
39     {
40         cerr << "fail to create socket, err: " << strerror(errno) << endl;
41         return -1;
42     }
43     cout << "create socket fd " << iSockFd << endl;
44
45     sockaddr_in oServerAddr;
46     memset(&oServerAddr, 0, sizeof(oServerAddr));
47     oServerAddr.sin_family = AF_INET;
48     oServerAddr.sin_addr.s_addr = iIp;
49     oServerAddr.sin_port = htons(usPort);
50     ssize_t iSendLen = sendto(iSockFd, szMsg, uiMsgLen, 0, (sockaddr *)&oServerAddr, sizeof(oServerAddr));
51     if (iSendLen < 0)
52     {
53         cerr << "fail to send, err: " << strerror(errno) << endl;
54         return -1;
55     }
56     cout << "send to " << szIp <<  ":" << usPort << ", len: " << uiMsgLen << ", msg: " << szMsg << endl;
57
58     char szRecvBuf[64 * 1024];
59     sockaddr_in oRecvAddr;
60     socklen_t iAddrLen = sizeof(oRecvAddr);
61     ssize_t iRecvLen = recvfrom(iSockFd, szRecvBuf, sizeof(szRecvBuf), 0, (sockaddr *)&oRecvAddr, &iAddrLen);
62     if (iRecvLen < 0)
63     {
64         cerr << "fail to recv, err: " << strerror(errno) << endl;
65         return -1;
66     }
67     szRecvBuf[iRecvLen] = ‘\0‘;
68     cout << "recv from " << inet_ntoa(oRecvAddr.sin_addr) << ":" << ntohs(oRecvAddr.sin_port) << ", len: " << iRecvLen << ", msg: " << szRecvBuf << endl;
69
70     return 0;
71 }