WinSock getservbyname() error 11004

[David Cross]

I am trying to write a simple WinSock server (NT4 SP2 MSVC5) that client
applications can connect over TCP/IP.
The code below is about where I am at.

The problem I have is that 'getservbyname()' always fails with error code
11004
returned from 'WSAGetLastError()'.

I am not quite sure what the first argument to getservbyname() should be...
but whatever
I try, the call always fails.

What am I missing here?
What does 'getservbyname()' actually do on NT?

Any help appreciated.

SOCKADDR_IN sa;
WSADATA WSAData;
char szMyName[256];
HOSTENT* pHostEnt;
SERVENT* pServEnt;
SOCKET sListen = INVALID_SOCKET;
WORD wVersionRequested = MAKEWORD( 2, 0 );

if (WSAStartup(wVersionRequested, &WSAData) != 0) {
printf("\nWSAStartup() failed, err = %d\n", WSAGetLastError());
goto cleanup;
}

if ((sListen = socket(AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET) {
printf("\nsocket() failed, err = %d\n", WSAGetLastError());
goto cleanup;
}

if (gethostname(szMyName, sizeof(szMyName)) != 0) {
printf("\ngethostname() failed, err = %d\n", WSAGetLastError());
goto cleanup;
}

if ((pHostEnt = gethostbyname(szMyName)) == NULL) {
printf("\ngethostbyname() failed, err = %d\n", WSAGetLastError());
goto cleanup;
}

sa.sin_family = AF_INET;
memcpy(&sa.sin_addr, pHostEnt->h_addr_list[0], pHostEnt->h_length);

if ((pServEnt = getservbyname( "some service", "tcp")) == NULL) {
printf("\ngetservbyname() failed, err = %d\n", WSAGetLastError());
goto cleanup;
}

sa.sin_port = pServEnt->s_port;

if (bind(sListen, (SOCKADDR*)&sa, sizeof (SOCKADDR)) != 0) {
printf("\nbind() failed, err = %d\n", WSAGetLastError());
goto cleanup;
}

--
Dave
Amsterdam
da...@smallplanet.nl

[Michael Vaserman]

Basically, according to the KB article Q130024, all getservbyname() does is
look for the entry in the SERVICES file that corresponds to the requested
service name.

Error 11004 is WSANO_DATA according to WINSOCK.H, which probably means
there is no entry for this service in your SERVICES file
(%SystemRoot%\System32\DRIVERS\ETC).

David Cross <da...@smallplanet.nl> wrote in article
<01bc5b9c$ec7249b0$67f10bc3@athena>...