IPv6-Enabled Client Code
The following code is the IP agnostic Client.c file, which is an IPv6-enabled version of the Simplec.c file.
// client.c - Simple TCP/UDP client using Winsock 2.2
//
// This is a part of the Microsoft<entity type="reg"/> Source Code Samples.
// Copyright 1996 - 2000 Microsoft Corporation.
// All rights reserved.
// This source code is only intended as a supplement to
// Microsoft Development Tools and/or WinHelp<entity type="reg"/> documentation.
// See these sources for detailed information regarding the
// Microsoft samples programs.
//
#define WIN32_LEAN_AND_MEAN
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <stdlib.h>
//#include <string.h>
// Needed for the Windows 2000 IPv6 Tech Preview.
#if (_WIN32_WINNT == 0x0500)
#include <tpipv6.h>
#endif
// Link with ws2_32.lib
#pragma comment(lib, "Ws2_32.lib")
#define STRICMP _stricmp
//
// This code assumes that at the transport level, the system only supports
// one stream protocol (TCP) and one datagram protocol (UDP). Therefore,
// specifying a socket type of SOCK_STREAM is equivalent to specifying TCP
// and specifying a socket type of SOCK_DGRAM is equivalent to specifying UDP.
//
#define DEFAULT_SERVER NULL // Will use the loopback interface
#define DEFAULT_FAMILY PF_UNSPEC // Accept either IPv4 or IPv6
#define DEFAULT_SOCKTYPE SOCK_STREAM // TCP
#define DEFAULT_PORT "5001" // Arbitrary, albiet a historical test port
#define DEFAULT_EXTRA 0 // Number of "extra" bytes to send
#define BUFFER_SIZE 65536
#define UNKNOWN_NAME "<unknown>"
void Usage(char *ProgName)
{
fprintf(stderr, "\nSimple socket sample client program.\n");
fprintf(stderr,
"\n%s [-s server] [-f family] [-t transport] [-p port] [-b bytes] [-n number]\n\n",
ProgName);
fprintf(stderr, " server\tServer name or IP address. (default: %s)\n",
(DEFAULT_SERVER == NULL) ? "loopback address" : DEFAULT_SERVER);
fprintf(stderr,
" family\tOne of PF_INET, PF_INET6 or PF_UNSPEC. (default: %s)\n",
(DEFAULT_FAMILY ==
PF_UNSPEC) ? "PF_UNSPEC" : ((DEFAULT_FAMILY ==
PF_INET) ? "PF_INET" : "PF_INET6"));
fprintf(stderr, " transport\tEither TCP or UDP. (default: %s)\n",
(DEFAULT_SOCKTYPE == SOCK_STREAM) ? "TCP" : "UDP");
fprintf(stderr, " port\t\tPort on which to connect. (default: %s)\n",
DEFAULT_PORT);
fprintf(stderr, " bytes\t\tBytes of extra data to send. (default: %d)\n",
DEFAULT_EXTRA);
fprintf(stderr, " number\tNumber of sends to perform. (default: 1)\n");
fprintf(stderr, " (-n by itself makes client run in an infinite loop,");
fprintf(stderr, " Hit Ctrl-C to terminate)\n");
WSACleanup();
exit(1);
}
LPTSTR PrintError(int ErrorCode)
{
static TCHAR Message[1024];
// If this program was multithreaded, we'd want to use
// FORMAT_MESSAGE_ALLOCATE_BUFFER instead of a static buffer here.
// (And of course, free the buffer when we were done with it)
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS |
FORMAT_MESSAGE_MAX_WIDTH_MASK,
NULL, ErrorCode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
Message, 1024, NULL);
return Message;
}
int ReceiveAndPrint(SOCKET ConnSocket, char *Buffer, int BufLen)
{
int AmountRead;
AmountRead = recv(ConnSocket, Buffer, BufLen, 0);
if (AmountRead == SOCKET_ERROR) {
fprintf(stderr, "recv() failed with error %d: %s\n",
WSAGetLastError(), PrintError(WSAGetLastError()));
closesocket(ConnSocket);
WSACleanup();
exit(1);
}
//
// We are not likely to see this with UDP, since there is no
// 'connection' established.
//
if (AmountRead == 0) {
printf("Server closed connection\n");
closesocket(ConnSocket);
WSACleanup();
exit(0);
}
printf("Received %d bytes from server: [%.*s]\n",
AmountRead, AmountRead, Buffer);
return AmountRead;
}
int main(int argc, char **argv)
{
char Buffer[BUFFER_SIZE], AddrName[NI_MAXHOST];
char *Server = DEFAULT_SERVER;
int Family = DEFAULT_FAMILY;
int SocketType = DEFAULT_SOCKTYPE;
char *Port = DEFAULT_PORT;
WSADATA wsaData;
int i, RetVal, AddrLen, AmountToSend;
int ExtraBytes = DEFAULT_EXTRA;
unsigned int Iteration, MaxIterations = 1;
BOOL RunForever = FALSE;
ADDRINFO Hints, *AddrInfo, *AI;
SOCKET ConnSocket = INVALID_SOCKET;
struct sockaddr_storage Addr;
if (argc > 1) {
for (i = 1; i < argc; i++) {
if (((argv[i][0] == '-') || (argv[i][0] == '/')) &&
(argv[i][1] != 0) && (argv[i][2] == 0)) {
switch (tolower(argv[i][1])) {
case 'f':
if (!argv[i + 1])
Usage(argv[0]);
if (!STRICMP(argv[i + 1], "PF_INET"))
Family = PF_INET;
else if (!STRICMP(argv[i + 1], "AF_INET"))
Family = PF_INET;
else if (!STRICMP(argv[i + 1], "PF_INET6"))
Family = PF_INET6;
else if (!STRICMP(argv[i + 1], "AF_INET6"))
Family = PF_INET6;
else if (!STRICMP(argv[i + 1], "PF_UNSPEC"))
Family = PF_UNSPEC;
else if (!STRICMP(argv[i + 1], "AF_UNSPEC"))
Family = PF_UNSPEC;
else
Usage(argv[0]);
i++;
break;
case 't':
if (!argv[i + 1])
Usage(argv[0]);
if (!STRICMP(argv[i + 1], "TCP"))
SocketType = SOCK_STREAM;
else if (!STRICMP(argv[i + 1], "UDP"))
SocketType = SOCK_DGRAM;
else
Usage(argv[0]);
i++;
break;
case 's':
if (argv[i + 1]) {
if (argv[i + 1][0] != '-') {
Server = argv[++i];
break;
}
}
Usage(argv[0]);
break;
case 'p':
if (argv[i + 1]) {
if (argv[i + 1][0] != '-') {
Port = argv[++i];
break;
}
}
Usage(argv[0]);
break;
case 'b':
if (argv[i + 1]) {
if (argv[i + 1][0] != '-') {
ExtraBytes = atoi(argv[++i]);
if (ExtraBytes >
sizeof (Buffer) -
sizeof ("Message #4294967295"))
Usage(argv[0]);
break;
}
}
Usage(argv[0]);
break;
case 'n':
if (argv[i + 1]) {
if (argv[i + 1][0] != '-') {
MaxIterations = atoi(argv[++i]);
break;
}
}
RunForever = TRUE;
break;
default:
Usage(argv[0]);
break;
}
} else
Usage(argv[0]);
}
}
// Ask for Winsock version 2.2.
if ((RetVal = WSAStartup(MAKEWORD(2, 2), &wsaData)) != 0) {
fprintf(stderr, "WSAStartup failed with error %d: %s\n",
RetVal, PrintError(RetVal));
WSACleanup();
return -1;
}
//
// By not setting the AI_PASSIVE flag in the hints to getaddrinfo, we're
// indicating that we intend to use the resulting address(es) to connect
// to a service. This means that when the Server parameter is NULL,
// getaddrinfo will return one entry per allowed protocol family
// containing the loopback address for that family.
//
memset(&Hints, 0, sizeof (Hints));
Hints.ai_family = Family;
Hints.ai_socktype = SocketType;
RetVal = getaddrinfo(Server, Port, &Hints, &AddrInfo);
if (RetVal != 0) {
fprintf(stderr,
"Cannot resolve address [%s] and port [%s], error %d: %s\n",
Server, Port, RetVal, gai_strerror(RetVal));
WSACleanup();
return -1;
}
//
// Try each address getaddrinfo returned, until we find one to which
// we can successfully connect.
//
for (AI = AddrInfo; AI != NULL; AI = AI->ai_next) {
// Open a socket with the correct address family for this address.
ConnSocket = socket(AI->ai_family, AI->ai_socktype, AI->ai_protocol);
//**** DEBUG
printf("socket call with family: %d socktype: %d, protocol: %d\n",
AI->ai_family, AI->ai_socktype, AI->ai_protocol);
if (ConnSocket == INVALID_SOCKET)
printf("socket call failed with %d\n", WSAGetLastError());
//**** DEBUG END
if (ConnSocket == INVALID_SOCKET) {
fprintf(stderr, "Error Opening socket, error %d: %s\n",
WSAGetLastError(), PrintError(WSAGetLastError()));
continue;
}
//
// Notice that nothing in this code is specific to whether we
// are using UDP or TCP.
//
// When connect() is called on a datagram socket, it does not
// actually establish the connection as a stream (TCP) socket
// would. Instead, TCP/IP establishes the remote half of the
// (LocalIPAddress, LocalPort, RemoteIP, RemotePort) mapping.
// This enables us to use send() and recv() on datagram sockets,
// instead of recvfrom() and sendto().
//
printf("Attempting to connect to: %s\n", Server ? Server : "localhost");
if (connect(ConnSocket, AI->ai_addr, (int) AI->ai_addrlen) != SOCKET_ERROR)
break;
i = WSAGetLastError();
if (getnameinfo(AI->ai_addr, (int) AI->ai_addrlen, AddrName,
sizeof (AddrName), NULL, 0, NI_NUMERICHOST) != 0)
strcpy_s(AddrName, sizeof (AddrName), UNKNOWN_NAME);
fprintf(stderr, "connect() to %s failed with error %d: %s\n",
AddrName, i, PrintError(i));
closesocket(ConnSocket);
}
if (AI == NULL) {
fprintf(stderr, "Fatal error: unable to connect to the server.\n");
WSACleanup();
return -1;
}
//
// This demonstrates how to determine to where a socket is connected.
//
AddrLen = sizeof (Addr);
if (getpeername(ConnSocket, (LPSOCKADDR) & Addr, (int *) &AddrLen) == SOCKET_ERROR) {
fprintf(stderr, "getpeername() failed with error %d: %s\n",
WSAGetLastError(), PrintError(WSAGetLastError()));
} else {
if (getnameinfo((LPSOCKADDR) & Addr, AddrLen, AddrName,
sizeof (AddrName), NULL, 0, NI_NUMERICHOST) != 0)
strcpy_s(AddrName, sizeof (AddrName), UNKNOWN_NAME);
printf("Connected to %s, port %d, protocol %s, protocol family %s\n",
AddrName, ntohs(SS_PORT(&Addr)),
(AI->ai_socktype == SOCK_STREAM) ? "TCP" : "UDP",
(AI->ai_family == PF_INET) ? "PF_INET" : "PF_INET6");
}
// We are done with the address info chain, so we can free it.
freeaddrinfo(AddrInfo);
//
// Find out what local address and port the system picked for us.
//
AddrLen = sizeof (Addr);
if (getsockname(ConnSocket, (LPSOCKADDR) & Addr, &AddrLen) == SOCKET_ERROR) {
fprintf(stderr, "getsockname() failed with error %d: %s\n",
WSAGetLastError(), PrintError(WSAGetLastError()));
} else {
if (getnameinfo((LPSOCKADDR) & Addr, AddrLen, AddrName,
sizeof (AddrName), NULL, 0, NI_NUMERICHOST) != 0)
strcpy_s(AddrName, sizeof (AddrName), UNKNOWN_NAME);
printf("Using local address %s, port %d\n",
AddrName, ntohs(SS_PORT(&Addr)));
}
//
// Send and receive in a loop for the requested number of iterations.
//
for (Iteration = 0; RunForever || Iteration < MaxIterations; Iteration++) {
// Compose a message to send.
AmountToSend =
sprintf_s(Buffer, sizeof (Buffer), "Message #%u", Iteration + 1);
for (i = 0; i < ExtraBytes; i++) {
Buffer[AmountToSend++] = (char) ((i & 0x3f) + 0x20);
}
// Send the message. Since we are using a blocking socket, this
// call shouldn't return until it's able to send the entire amount.
RetVal = send(ConnSocket, Buffer, AmountToSend, 0);
if (RetVal == SOCKET_ERROR) {
fprintf(stderr, "send() failed with error %d: %s\n",
WSAGetLastError(), PrintError(WSAGetLastError()));
WSACleanup();
return -1;
}
printf("Sent %d bytes (out of %d bytes) of data: [%.*s]\n",
RetVal, AmountToSend, AmountToSend, Buffer);
// Clear buffer just to prove we're really receiving something.
memset(Buffer, 0, sizeof (Buffer));
// Receive and print server's reply.
ReceiveAndPrint(ConnSocket, Buffer, sizeof (Buffer));
}
// Tell system we're done sending.
printf("Done sending\n");
shutdown(ConnSocket, SD_SEND);
//
// Since TCP does not preserve message boundaries, there may still
// be more data arriving from the server. So we continue to receive
// data until the server closes the connection.
//
if (SocketType == SOCK_STREAM)
while (ReceiveAndPrint(ConnSocket, Buffer, sizeof (Buffer)) != 0) ;
closesocket(ConnSocket);
WSACleanup();
return 0;
}
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