getpeername() return 0 but with IP address "0.0.0.0"

[Fei Rao]

Hi all,

The server is listening on a specified port. When a connection request comes, the server accepts the request and then fork() a child. Then the server call getpeername() and getsockname() to get the client's and server's addresses. Unfortunately both two calls succeed and return addresses "0.0.0.0" and ports "0".

I looked up the manual and search through google, but didn't found any solutions. Do you have any ideas about this problem?

HP-UX B.11.23 9000/800 on PA-RISC

Fei

[Arunvijai_4]

Hi Fei,

Check for IPv6 is enabled on your server ?

# ifconfig will show it.

-Arun

[Fei Rao]

No. Just IPv4.

Here's the source code fragment:

struct sockaddr_in peerAddr, servAddr;
int addrlen = sizeof (sockaddr_in);

if (-1 == (getpeername(sockFd, (struct sockaddr *)&peerAddr, &addrlen)))
exitError("getpeername()");

addrlen = sizeof (sockaddr_in);
if (-1 == (getsockname(sockFd, (struct sockaddr *)&servAddr, &addrlen)))
exitError("getsockname()");

cout << "Peer IP: " << inet_ntoa(peerAddr.sin_addr) << " PORT: "<< ntohs(peerAddr.sin_port) << endl;

cout << "Serv IP: " << inet_ntoa(servAddr.sin_addr) << " PORT: " << ntohs(servAddr.sin_port) << endl;

Here's the output:
Peer IP: 0.0.0.0 PORT: 0
Serv IP: 0.0.0.0 PORT: 0

[Torsten.]

Many many years ago for me, but I guess to remember I used inet_ntoa(peerAddr.sin_addr.s_addr).
I'm not sure, because I didn't write any C stuff for years.

[Fei Rao]

Actually, the whole structure peerAddr and servAddr are filled with '\0' as if I use memset() to set all bits to 0.

[rick jones]

A couple things - accept() will also return the remote addressing information, so you can eliminate the per-connection getpeername() call :)

You might consider doing an memset to something other than "0" on the sockaddr so you can see if the calls are setting them to zero or simply not setting them at all.

Also, a tusc trace of the calls might be a good idea. Make it a verbose one.