Address already in use

Hi All,

Got a problem restarting my server:

bind: Address already in use

I start it like:

Code:

---

                      srv.sin_addr.s_addr = INADDR_ANY;
                        srv.sin_port = htons( port);
                        srv.sin_family = AF_INET;

                        sock_opt = 1;
                        if(setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(void *)&sock_opt,sizeof(sock_opt)) == -1)
                        {
                                perror("setsockopt(SO_REUSEADDR)");
                                close(s);
                                return 3;
                        }

                        if(bind(s,(struct sockaddr *)&srv,sizeof(srv)) == -1)
                        {
                                perror("bind");
                                close(s);
                                return 4;
                        }

                        if(listen(s,3) == -1)
                        {
                                perror("listen");
                                close(s);
                                return 5;
                        }

---

So it should be reusing the socket.

Had a look in nestat and:

Code:

---

tcp      25      0 localhost:5580          localhost:40353        CLOSE_WAIT
tcp      48      0 localhost:5580          localhost:40352        CLOSE_WAIT
tcp      25      0 localhost:5580          localhost:40361        CLOSE_WAIT
tcp      48      0 localhost:5580          localhost:40360        CLOSE_WAIT

---

Connections in CLOSE_WAIT state.

Any ideas how I can get round this?

Cheers, rotis23

so_resuse should do the trick.

Do you have something like
memset(&(srv.sin_zero), '\0', 8);

I presume sock_opt is an int?

Hi Hammer,

When you say so_resuse, you are agreeing with SO_REUSEADDR?

Hmm. I don't memset anything, only this before previously posted code:

Code:

---

int s, sock_opt, client, cli_size, pid, res, result = 0;
struct sockaddr_in srv, cli;

//fork code

                        //signal handler code

                        s = socket(AF_INET, SOCK_STREAM, 0);
                        if(s == -1)
                        {
                                perror("socket");
                                return 2;
                        }

---

Should I be more careful here?

>>When you say so_resuse, you are agreeing with SO_REUSEADDR?
Yes

>>memset
Yes, you should be memset()'ing.
Sample:
http://personal.windsofstorm.net/tserver.c

I see.

Thanks Hammer.

I had a look around after your last post and noticed that there are:

SO_REUSEADDR
SO_REUSEPORT

From this thread I guess SO_REUSEPORT is not needed because it allows multiple processes to bind to the same address:

http://www.unixguide.net/network/socketfaq/4.11.shtml

I'm also not sure if this is implemented on RedHat Linux systems or if it's just BSD.

So, are you fixed or not?

Not sure - going to do some load testing tomorrow and see if I can reproduce.

I've added the memset though.