pptp_gre.h

pptp第二层隧道模块

/* pptp_gre.h -- encapsulate PPP in PPTP-GRE.
 *               Handle the IP Protocol 47 portion of PPTP.
 *               C. Scott Ananian <[e-mail]>
 *
 * $Id: pptp_gre.h,v 1.5 2004/06/09 00:13:32 quozl Exp $
 */

int pptp_gre_bind(struct in_addr inetaddr);
void pptp_gre_copy(u_int16_t call_id, u_int16_t peer_call_id,
		   int pty_fd, int gre_fd);

extern int syncppp;
extern int disable_buffer;

typedef struct pack_track {
  uint32_t seq;       // seq no of this tracked packet
  uint64_t time;      // time when this tracked packet was sent (in usecs)
} pack_track_t;

typedef struct gre_stats {
  /* statistics for GRE receive */

  uint32_t rx_accepted;  // data packet was passed to pppd
  uint32_t rx_lost;      // data packet did not arrive before timeout
  uint32_t rx_underwin;  // data packet was under window (arrived too late
                         // or duplicate packet)
  uint32_t rx_overwin;   // data packet was over window
                         // (too many packets lost?)
  uint32_t rx_buffered;  // data packet arrived earlier than expected,
                         // packet(s) before it were lost or reordered
  uint32_t rx_errors;    // OS error on receive
  uint32_t rx_truncated; // truncated packet
  uint32_t rx_invalid;   // wrong protocol or invalid flags 
  uint32_t rx_acks;      // acknowledgement only

  /* statistics for GRE transmit */

  uint32_t tx_sent;      // data packet write() to GRE socket succeeded
  uint32_t tx_failed;    // data packet write() to GRE socket returned error
  uint32_t tx_short;     // data packet write() to GRE socket underflowed
  uint32_t tx_acks;      // sent packet with just ACK
  uint32_t tx_oversize;  // data packet dropped because it was too large

  /* statistics for packet tracking, for RTT calculation */

  pack_track_t pt;       // last data packet seq/time
  int rtt;               // estimated round-trip time in us

} gre_stats_t;

extern gre_stats_t stats;