getsockname()

[Christian Klein]

Hi,
I have a problem that is similar to the problem described in 
http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/22868

My program, that opens a tcp socket and binds to INADDR_ANY:0, 
getsockname() returns either the correct answer
or, for some time, a wrong answer, see below

(this is of course not my program, just some code that does the same)

--- snipp ---
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int main()
{
     int sock, len;
     struct sockaddr_in addr, foo;

     if((sock=socket(AF_INET, SOCK_STREAM, 0))<0)
     {
         exit(0);
     }

     memset(&addr, 0, sizeof(struct sockaddr_in));
     addr.sin_family = AF_INET;
     addr.sin_addr.s_addr = INADDR_ANY;
     addr.sin_port = htons(0);

     if(bind(sock, (struct sockaddr *) &addr, sizeof(struct 
sockaddr_in))<0)
     {
         perror("bind");
         exit(0);
     }

     if(listen(sock, 5)<0)
     {
         perror("listen");
         exit(0);
     }

     getsockname(sock, (struct sockaddr *) &foo, &len);
     fprintf(stderr, "listening on %s:%d\n", inet_ntoa(foo.sin_addr), 
ntohs(foo.sin_port));

     return 0;
}

--- snap ---


$ ./a.out
listening on 86.186.4.40:49087
$ ./a.out
listening on 0.0.0.0:3810

regards,
Chris

PS: It is even stranger than I thought, I compiled this program: gcc -o 
freebsd freebsd.c and ran it serveral times:
  $ ./freebsd
listening on 86.186.4.40:49087
  $ mv freebsd a.out
  $ ./a.out
listening on 0.0.0.0:4364
  $ mv a.out freebsd
  $ ./freebsd
listening on 86.186.4.40:49087
  $ mv freebsd a.out
  $ ./a.out
listening on 0.0.0.0:4604