/* $Header: /CVSROOT/debris/drisnext.h,v 1.7 2005/08/15 01:04:52 tino Exp $
 *
 * DebRIS: DEBian Remote Install Scripter
 * Fetch the "next" step from the network (or whatever).
 *
 * $Log: drisnext.h,v $
 * Revision 1.7  2005/08/15 01:04:52  tino
 * all functions now have a prefix (dris_)
 *
 * Revision 1.6  2005/08/15 00:47:45  tino
 * updates for DebRIS improvements
 *
 * Revision 1.5  2005/08/13 22:59:12  tino
 * additional functions, see ChangeLog
 *
 * Revision 1.4  2005/07/25 03:24:23  tino
 * md5 functions moved to drismd5
 *
 * Revision 1.3  2005/07/24 22:16:54  tino
 * now use snprintf
 *
 * Revision 1.2  2005/06/01 02:39:04  tino
 * now it compiles
 *
 * Revision 1.1  2005/06/01 02:12:35  tino
 * first version.  As SirbeD is missing, this just does nothing yet.
 */

#include "driscurl.h"

#include <openssl/md5.h>

#include "tino/xd.h"

static const char *
dris_next_check(struct dris_buf *buf)
{
  int		i;
  const char	*cmp;

  if (config.debug)
    tino_xd(stderr, "<", 8, 0, buf->buf, buf->len);
  for (i=0; buf->buf[i]!='\r' || buf->buf[i+1]!='\n'; i++)
    if (!buf->buf[i])
      return "missing first line terminator";
  if ((i+=2)>buf->len)
    return "BUG: i>buf->len";
  dris_md5_cksum_init();
  dris_md5_add(buf->buf+i, buf->len-i);
  cmp	= dris_md5_get();
  if (strncmp(buf->buf, cmp, strlen(cmp)))
    return "checksum mismatch";
  dris_buf_add(dris_buf_reset(config.out), buf->buf+i, buf->len-i);
  return 0;
}

/* This here is the black magic function to fetch the next step to do.
 *
 * It knows about the config struct.
 * It contacts URL for data transfer.
 * It sends config.result and config.out to the network.
 * It reads config.in from the network.
 * It verifies the correctness of the received data.
 */
static int
dris_next(void)
{
  static struct dris_buf	*in, *out;
  static int (			*fn)(struct dris_buf *, struct dris_buf *) = dris_curl;
  int				retry;
  char				tmp[256];

  if (!in)
    in	= dris_buf_new();
  if (!out)
    out	= dris_buf_new();

  snprintf(tmp, sizeof tmp, "%s %lld\r\n%d\r\n", config.id, config.cnt, config.result);

  dris_md5_cksum_init();
  dris_md5_add_s(tmp);
  dris_md5_add(config.out->buf, config.out->len);

  dris_buf_reset(in);
  dris_buf_add_s(in, dris_md5_get());
  dris_buf_add_s(in, tmp);
  dris_buf_add(in, config.out->buf, config.out->len);

  retry	= 0;
  for (;;)
    {
      int	err;

      dris_buf_reset(out);
      dris_verbose("[%lld] send %ld bytes to %s\n", config.cnt, (long)in->len, config.url);
      if ((err=fn(in, out))==0)
	{
	  const char	*err;

	  dris_verbose("* got %lu bytes\n", (unsigned long)out->len);
	  err	= dris_next_check(out);
	  if (!err)
	    return 1;
	  dris_verbose("* data error: %s\n", err);
	}
      retry++;
      dris_info("* failed with error code %d", err);
      err	= (retry>60 ? 60 : retry);
      dris_verbose(", sleeping %d ..", err);
      sleep(err);
      dris_info(" retry %d\n", retry);
    }
}