New encrypting tunnel seems to work !

[userv-utils] / ipif / mech-timestamp.c

/*
 * Timestamp mechanism
 *
 * arguments: <max-skew> <max-age>
 *
 * encoding: prepend 4 bytes of UNIX time in network byte order
 *
 * <max-age> is maximum age in seconds we will accept a packet (or 0
 * for any age); <max-skew> is maximum future age in seconds we will
 * accept a packet (or 0 for any future age).
 *
 */

#include <stdint.h>
#include <netinet/in.h>

#include "forwarder.h"

struct mechdata {
  time_t max_skew, max_age;
};

static void mds_timestamp(struct mechdata **md_r) {
  struct mechdata *md;

  md= xmalloc(sizeof(md));
  
  md->max_skew= getarg_ulong();
  md->max_age= getarg_ulong();
  *md_r= md;
}

static void mes_timestamp(struct mechdata **md_r, int *maxprefix_io, int *maxsuffix_io) {
  mds_timestamp(md_r);
  *maxprefix_io += 4;
}

static void menc_timestamp(struct mechdata *md, struct buffer *buf) {
  *(uint32_t*)buf_prepend(buf,4)= htonl(now());
}
  
static const char *mdec_timestamp(struct mechdata *md, struct buffer *buf) {
  static char cbuf[40];
  
  uint32_t *tp, timestamp, tnow;
  long age;

  BUF_UNPREPEND(tp,buf,4);
  timestamp= ntohl(*tp);

  tnow= now();
  age= timestamp - tnow;
  if (age > 0) {
    if (md->max_age && age > md->max_age) {
      sprintf(cbuf,"packet too old (%lds)",age);
      return cbuf;
    }
  } else if (age < 0) {
    if (md->max_skew && age < -md->max_skew) {
      sprintf(cbuf,"too much skew (%lds)",-age);
      return cbuf;
    }
  }

  return 0;
}

STANDARD_MECHANISMLIST("timestamp",timestamp);