Re: Monitoring sshd

[Jan-Henrik Haukeland]

David Fletcher <address@hidden> writes:

> Looking at the file "protocols/ssh.c" in the Monit distribution reveals
> that whatever identification string the server sends out, Monit sends
> the same thing back.

Hmm, not quite, chomp() strips the ending CRLF. Since it works with
the predefined string (with CRLF) it is a strong indication that the
problem is the missing CRLF in the string sent back to the server.

Does the following (untested) change fix the problem?

int check_ssh(Socket_T s) {

  int n;
  char  buf[STRLEN];

  ASSERT(s);
    
  if((n= socket_read(s, buf, sizeof(buf))) <= 0) {
    log("SSH: error receiving identification string -- %s\n", STRERROR);
    return FALSE;
  }

  if(strncmp(buf, "SSH-", 4) != 0) {
    log("SSH: protocol error %s\n", buf);
    return FALSE;
  }

  /* send identification string back to server */
  if(socket_write(s, buf, n) <= 0) {
    log("SSH: error sending identification string -- %s\n", STRERROR);
    return FALSE;
  }
   
  return TRUE;
  
}

-- 
Jan-Henrik Haukeland