why is this crashing?

[Red Squirrel]

I have this loop that for some reason it just decides to crash. No error, no nothing, the program just terminates. And it's not normal termination as normal termination involves much more output at the end, but this just stops completely, right in the middle of the transfer. This program does the same transfer over and over (it's sort of a DoS tool to test server stability etc) so sometimes it will send it about 500 times then crash, sometimes it will crash at the 1st try etc... it's completely random.

Code: Select all

fstream file2send(file.c_str(),ios::in);

int bytes=0;
char data;
while(!file2send.eof())
{
cout<<"\rSending "<<bytes<<" bytes...";

file2send.get(data);
send(sockfd,&data,1,0);

bytes++;
}
cout<<"done.";
file2send.close();


If needed the full source code is here:
http://www.iceteks.com/misc/socksend.cpp

[Dante Shamest]

Completely random you say? Hmm, that's indeed strange. I wonder if it's the send function that failing.

Try replacing the code you posted with the following code.

Code: Select all

ifstream file2send( file.c_str() );
file2send.get(data);
while( file2send ) {
  cout<<"\rSending "<<bytes<<" bytes...";
  if ( send(sockfd,&data,1,0) == -1 ) {
    cout << "send function failed\n" ;
  }
  file2send.get(data);
  bytes++;
}
cout<<"done.";
file2send.close();

[Red Squirrel]

Nope, it does not fail. I even added the send return value in the output and it stays at 1 all the time even after it just stops for no reason.

This is basically what my output looks like, 3 times trying it.

try 1:

Code: Select all

-------------------------------------------------------------------------------
Connection 1 of 1000000.
Connecting...ok
Sending(1borg:/data/samba/shared/ryan/applications/socksend#


try 2:

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-------------------------------------------------------------------------------
Connection 1 of 1000000.
Connecting...ok
Sending(1) 15432 byteborg:/data/samba/shared/ryan/applications/socksend#


try 3:

Code: Select all

-------------------------------------------------------------------------------
Connection 1 of 1000000.
Connecting...ok
Senborg:/data/samba/shared/ryan/applications/socksend#


Also, it depends on the host, which is really weird.... it should not matter. For example I tried it on my online site and google, and it will last a bit longer then if I use it on my local experimental IIS server, on my apache server it also lasts a bit longer. Also, I tried it on a different port (139) of the test server and it goes in ok. It's almost as if it depends what the server response is and how it's formatted or something but that can't be as most of the time I ingore the response, unless it still goes in some buffer somewhere which I have no control over.