Get public IP with winsock

[Alessio]

Code Select Expand


//
// get public ip
//
// by Alessio Ribeca <e-mail: peloquin at libero dot it>
//
// 11 aprile 2008
//

//
#define STRICT
#define WIN32_MEAN_AND_LEAN

//
#include <winsock.h>

//
#define __WINSOCK_VERSION__ 1
#define __RETRY__ 10
#define __SITE__ "www.ip-adress.com"

//
#pragma comment(lib, "user32.lib")
#pragma comment(lib, "wsock32.lib")

//
static LPCSTR szAppName = "MyIP";
static LPCSTR szGetIP = "GET / HTTP/1.1\r\n"
"Host: "__SITE__"\r\n"
"\r\n";

//
inline void find_string(char * string, char * pattern, char buffer[], int iBuffer, char c)
{
ZeroMemory(buffer, iBuffer);

char *pos = strstr(string, pattern);

if ( NULL == pos )
{
//
buffer[0] = '\0';

return;
}

int i = 0;

pos += strlen(pattern);

while ( *pos != c )
{
buffer[i] = *pos;
++pos;
++i;

if ( i > iBuffer )
{
buffer[0] = '\0';
return;
}
}
}


//
LPSTR GetIP(VOID)
{
WSADATA wsaData;

if ( 0 != WSAStartup(MAKEWORD(__WINSOCK_VERSION__,0), &wsaData) )
{
return "unable to start winsock";
}

//
if ( LOBYTE(wsaData.wVersion) < __WINSOCK_VERSION__ )
{
WSACleanup();

return "unable to start winsock";
}

//
LPHOSTENT lpHostent = gethostbyname(__SITE__);
if ( NULL == lpHostent )
{
WSACleanup();

return "gethostbyname() failed";
}

//
SOCKET s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if ( INVALID_SOCKET == s)
{
WSACleanup();

return "socket error";
}

// fill sockadd structure
struct sockaddr_in sa = { 0 };
sa.sin_addr.s_addr = inet_addr(inet_ntoa (*(struct in_addr *)*lpHostent->h_addr_list));
sa.sin_family = AF_INET;
sa.sin_port = htons(80);

//
INT iRetry = 0;
while ( connect(s, (SOCKADDR*)&sa, sizeof(sa)) == SOCKET_ERROR )
{
if ( ++iRetry > __RETRY__ )
{
WSACleanup();

return "unable to connect";
}
}

//
if ( SOCKET_ERROR == send(s, szGetIP, lstrlen(szGetIP), 0) )
{
WSACleanup();

return "send error";
}

// recv
char buffer[2048] = { 0 };
if ( recv (s, buffer, 2048, 0) == SOCKET_ERROR )
{
WSACleanup();

return "recv error";
}

CHAR szIp[16];
CHAR szLocation[64];
CHAR szLatitude[16];
CHAR szLongitude[16];
CHAR szIsp[64];

find_string(buffer, "My IP: ", szIp, 16, '<');
find_string(buffer, "IP Location: ", szLocation, 64, '<');
find_string(buffer, "Latitude: ", szLatitude, 16, '<');
find_string(buffer, "Longitude: ", szLongitude, 16, '<');
find_string(buffer, "My ISP: ", szIsp, 64, '<');

static CHAR szBuffer[256];
ZeroMemory(&szBuffer, 256);

wsprintf(szBuffer, "IP: %s\nLocation: %s\nLatitude: %s\nLongitude: %s\nISP: %s", szIp, szLocation, szLatitude, szLongitude, szIsp);

WSACleanup();

return szBuffer;
}

//
INT WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR szCmdLine, INT iCmdShow)
{
MessageBox(NULL, GetIP(), szAppName, MB_ICONINFORMATION);

return 0;
}



[Vortex]

Hi Alessio,

Thanks for the example. It works fine on my Win XP Pro Sp2 box.

[CLR]

Hello Alessio.

I got nothing. Here's output:

Code Select Expand


FILE *fp;
fp = fopen("ip.txt", "wb");
fwrite(buffer, sizeof(buffer), 1, fp);
fclose(fp);


[Alessio]

Hi CLR,

simply use more space for buffer variable.
Change recv buffer from 2048 to 4096.

Code Select Expand

// recv
char buffer[4096] = { 0 };
if ( recv (s, buffer, 4096, 0) == SOCKET_ERROR )
{
WSACleanup();

return "recv error";
}

[CLR]

Hello Alessio. Thanks.

For some reason changing from 2048 to 4096 didn't work. Another recv dit

Code Select Expand


char buffer[4096] = { 0 };
if ( recv (s, buffer, 4096, 0) == SOCKET_ERROR )
{
WSACleanup();

return "recv error";
}

[b]recv (s, buffer, 4096, 0);[/b]


[Alessio]

pls save to file buffer output and attach it!
Otherwise look for specified string like "My IP: " or "IP Location: "

thank you.

[CLR]

Hi Alessio.

I'm back. Please see the attachment. Thanks!

[Alessio]

Hi,

as you can see, you ip appear on file named ip2.txt, where appears next 4096 bytes of ip1.txt.
I don't know why your buffer is not large enough, but if you try a more big buffer, you'll success.
Try with 8192, 16304 or more.

Bye, Alessio.