Bug#614378: libc6: Select()don't work properly on squeeze amd64

[Luca Sillari <l.sillari@prc-el.it>]

Package: libc6
Version: 2.11.2-10
Severity: important



/ Author : L.Sillari
// Date: 17/02/2011

// This example show a bug on debian 6 64 bit .
// using nonblocking socket .
// On this example the code must run forever if you use an unknown destination.
// On Debina 6 64bit that not appen .. after the same time it stop because of "Select()" (the Select returns 1 and not 0) .
// No problem using Debian 6 32bit or Debian 5 64 bit

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/select.h>
#include <netinet/in.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>



    int sockfd; // Global variable
    main(int argc, char *argv[])
{

    //socket structure
    struct sockaddr_in serv_addr;
    struct hostent *server;
    int opts; // Socket Option
    int value=1;

    int _port=35; // TCP port 
    


    /// Open  socket 
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0)
    {
    	/// Error opening socket
        printf("\n Error on socket() exit.\n");
	    exit(1);
    }

    /// NonBlocking socket setup
    opts = fcntl(sockfd, F_GETFL, 0);
    if (opts!=-1) 
    {
    	opts=fcntl(sockfd, F_SETFL, opts | O_NONBLOCK);
    }
    if (opts==-1)
    {
    	/// Error
        printf("\n Error on fcntl()\n");
	    exit(1);
    }

if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, (char *)&value, sizeof(value)) < 0) 
{
        printf("\n Error on setsockopt()\n");
	    exit(1);
}

    /// Put an unknown address to verify the bug
    server = gethostbyname("192.168.79.110");
    if (server == NULL) 
    {
    	/// Error
        printf("\n Error on gethostbyname()\n");
	    exit(1);
    }
    memset((char *) &serv_addr, 0,sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    memcpy((char *)&serv_addr.sin_addr.s_addr,(char *)server->h_addr, server->h_length);
    serv_addr.sin_port = htons(_port);


    /// NONBLOCKING Connection 
    //opts=connect(sockfd,(const sockaddr *)&serv_addr,sizeof(serv_addr));
     opts=connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr));
    if ((opts < 0 ) && (errno != EINPROGRESS))
    {
        printf("\n Error on connect()\n");
        exit(1);
    }

    while (waitConnection(100) == 0)  // We poll the connection ..
    {
        printf("WaitConnection \n");
    }
    printf("\n This is the bug: on Debian 6 squeeze(64bit) not on Debian 5 Lenny(64bit) \n");
}


int waitConnection(int _ms)
{
    // wait the connection
    extern int sockfd;
    struct timeval tv;
    int retval;
    int valopt;
     socklen_t len;


    /// Connection handle
    fd_set cnds;
    FD_ZERO(&cnds);


    /// Init Timeout
    tv.tv_sec = 0;
    tv.tv_usec = _ms * 1000;

    FD_SET(sockfd,&cnds);

    /// Wait on the select.
    /// to verify the connection : writing channel
    retval = select(sockfd+1, NULL, &cnds, NULL , &tv);


    /// Error
    if ( retval < 0 ) 
    {
        printf("\n Error on select ... \n");
        exit(1);
    }

    /// Something appened
    if ( retval > 0 )
    {
	if ( FD_ISSET(sockfd,&cnds) )
		{
		
			//Error check
			
			len=sizeof(valopt);
			if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, (void*)(&valopt), &len) < 0) return 0;
			if (valopt!=0) return 0;
			printf("\n Wrong event : the destination doesn't exist but it seems connected !!!\n");
			return 1;
		}
    }
    return 0;
}





-- System Information:
Debian Release: 6.0
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.32-5-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages libc6 depends on:
ii  libc-bin                      2.11.2-10  Embedded GNU C Library: Binaries
ii  libgcc1                       1:4.4.5-8  GCC support library

libc6 recommends no packages.

Versions of packages libc6 suggests:
ii  debconf [debconf-2.0]         1.5.36.1   Debian configuration management sy
pn  glibc-doc                     <none>     (no description available)
ii  locales                       2.11.2-10  Embedded GNU C Library: National L

-- debconf information:
  glibc/upgrade: true
  glibc/disable-screensaver:
  glibc/restart-failed:
  glibc/restart-services: