Socket (3)

A typicalTCPPort ScannerConnectThe function tries to connect the server to determine whether the port on the server is open. This scanner is multi-threaded.WinSockMost programming uses multithreading technology to make full use of bandwidth, suchNetAntsOf5Ant downloads, someFTPMulti-thread upload of software, etc!

// Source code in C ++ builder5

CPP Code

1. # Pragma hdrstop
2. # Include "unit1.h"
3. # Define threadnum 10 // Number of threads
4. # Define mutexname "Welcome to lovebcb.yeah.net"
5. # Pragma package (smart_init)
6. # Pragma resource "*. DFM"
7. Typedef StructG_scan // This is a custom Structure
8. {
9. CharSzfile [40]; // name of the file used to store the result
10. CharSzmutex [40]; // used to store the name of the mutex. This is a method for multi-thread security.
11. UnsignedShortSport; // The starting port for scanning, In the byte sequence of the Local Machine
12. UnsignedShortEport; // The end port of the scan, In the byte sequence of the Local Machine
13. UnsignedLongGoali; // ip address of the target host, in bytes
14. IntResult; // used to store results
15. } * Pg_scan;
17. Tforlover * forlover; // This is the form
18. HandleHthread [threadnum];
19. G_scan gscan [threadnum];
20. DWORDDwthreadid, dwthreadcode;
21. UnsignedShortUspart; // used to separate the number of ports to be scanned and allocate them to each thread
22. UnsignedLongUlip;
23. IntIlivethread; // Number of threads used to store Activity
24. UnsignedLongServerip (Char* Serverip );
25. DWORDWinapi scanport (LpvoidLP)
26. /* This is the main thread function scanport */
27. DWORDWinapi scanport (LpvoidLP)
28. {
29. Pg_scan pgscan = (pg_scan) LP;
30. CharSzresult [40];
31. Sockaddr_in sock;
32. UnsignedShortNowport = pgscan → sport-1; // The port number used to store the current scan.
33. File* FP; // file pointer
35. HandleHmutex = openmutex (mutex_all_access,False, Pgscan → szmutex );
36. Socket Sk = socket (af_inet, sock_stream, 0 );
37. Sock. sin_family = af_inet;
38. Sock. sin_addr.s_addr = pgscan → goalip;
39. While(Nowport
40. {
41. Sock. sin_port = htons (++ nowport)
42. If(Connect (SK, (sockaddr *) & sock,Sizeof(Sock) = socket_error)
43. Continue;
44. /* Because the socket in blocking mode is used here, returning socket_error usually means that the connection fails. Therefore, use continue to end the loop, that is, start a loop again. If the returned value is not socket_error, the connection is successful, that is, the port is opened on the target host */
45. Wsprintf (szresult, "Target Host: % sport: % d Open/R/N", inet_ntoa (sock. sin_addr), nowport); waitforsingleobject (hmutex, infinite );
47. /* Use waitforsinleobject to ensure thread security. Infinite indicates waiting until the mutex has a signal */
48. Fp = fopen (pgscan → szfile, "");
49. Fwrite (szresult,Sizeof(Char), Strlen (szresult), FP );
50. Fclose (FP );
51. Pgscan → result ++;
52. Releasemutex (hmutex); // release the mutex
53. Closesocket (SK); // close the connection because a connection has been established.
54. SK = socket (af_inet, sock_stream, 0); // recreate a socket
55. }