e962a82308
instead of bumping the recvAck counter by one, pretend that all outstanding xmit packets are acknowleged, and restart transmitting anew, with an empty (but halved) transmit window. Put a lower bound on the adaptive timeout value.
911 lines
25 KiB
C
911 lines
25 KiB
C
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/*
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* ng_pptpgre.c
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*
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* Copyright (c) 1996-1999 Whistle Communications, Inc.
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* All rights reserved.
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*
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* Subject to the following obligations and disclaimer of warranty, use and
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* redistribution of this software, in source or object code forms, with or
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* without modifications are expressly permitted by Whistle Communications;
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* provided, however, that:
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* 1. Any and all reproductions of the source or object code must include the
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* copyright notice above and the following disclaimer of warranties; and
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* 2. No rights are granted, in any manner or form, to use Whistle
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* Communications, Inc. trademarks, including the mark "WHISTLE
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* COMMUNICATIONS" on advertising, endorsements, or otherwise except as
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* such appears in the above copyright notice or in the software.
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*
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* THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
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* TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
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* REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
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* INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
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* WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
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* REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
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* SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
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* IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
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* RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
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* WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
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* PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
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* OF SUCH DAMAGE.
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*
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* Author: Archie Cobbs <archie@whistle.com>
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*
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* $FreeBSD$
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* $Whistle: ng_pptpgre.c,v 1.7 1999/12/08 00:10:06 archie Exp $
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*/
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/*
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* PPTP/GRE netgraph node type.
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*
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* This node type does the GRE encapsulation as specified for the PPTP
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* protocol (RFC 2637, section 4). This includes sequencing and
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* retransmission of frames, but not the actual packet delivery nor
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* any of the TCP control stream protocol.
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*
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* The "upper" hook of this node is suitable for attaching to a "ppp"
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* node link hook. The "lower" hook of this node is suitable for attaching
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* to a "ksocket" node on hook "inet/raw/gre".
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/time.h>
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#include <sys/mbuf.h>
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#include <sys/malloc.h>
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#include <sys/errno.h>
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#include <sys/socket.h>
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#include <sys/syslog.h>
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#include <sys/ctype.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netgraph/ng_message.h>
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#include <netgraph/netgraph.h>
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#include <netgraph/ng_parse.h>
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#include <netgraph/ng_pptpgre.h>
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/* GRE packet format, as used by PPTP */
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struct greheader {
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#if BYTE_ORDER == LITTLE_ENDIAN
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u_char recursion:3; /* recursion control */
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u_char ssr:1; /* strict source route */
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u_char hasSeq:1; /* sequence number present */
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u_char hasKey:1; /* key present */
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u_char hasRoute:1; /* routing present */
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u_char hasSum:1; /* checksum present */
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u_char vers:3; /* version */
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u_char flags:4; /* flags */
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u_char hasAck:1; /* acknowlege number present */
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#elif BYTE_ORDER == BIG_ENDIAN
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u_char hasSum:1; /* checksum present */
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u_char hasRoute:1; /* routing present */
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u_char hasKey:1; /* key present */
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u_char hasSeq:1; /* sequence number present */
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u_char ssr:1; /* strict source route */
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u_char recursion:3; /* recursion control */
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u_char hasAck:1; /* acknowlege number present */
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u_char flags:4; /* flags */
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u_char vers:3; /* version */
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#else
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#error BYTE_ORDER is not defined properly
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#endif
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u_int16_t proto; /* protocol (ethertype) */
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u_int16_t length; /* payload length */
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u_int16_t cid; /* call id */
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u_int32_t data[0]; /* opt. seq, ack, then data */
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};
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/* The PPTP protocol ID used in the GRE 'proto' field */
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#define PPTP_GRE_PROTO 0x880b
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/* Bits that must be set a certain way in all PPTP/GRE packets */
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#define PPTP_INIT_VALUE ((0x2001 << 16) | PPTP_GRE_PROTO)
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#define PPTP_INIT_MASK 0xef7fffff
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/* Min and max packet length */
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#define PPTP_MAX_PAYLOAD (0xffff - sizeof(struct greheader) - 8)
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/* All times are scaled by this (PPTP_TIME_SCALE time units = 1 sec.) */
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#define PPTP_TIME_SCALE 1000 /* milliseconds */
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typedef u_int32_t pptptime_t;
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/* Acknowledgment timeout parameters and functions */
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#define PPTP_XMIT_WIN 16 /* max xmit window */
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#define PPTP_MIN_RTT (PPTP_TIME_SCALE / 10) /* 100 milliseconds */
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#define PPTP_MIN_TIMEOUT (PPTP_TIME_SCALE / 100) /* 10 milliseconds */
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#define PPTP_MAX_TIMEOUT (10 * PPTP_TIME_SCALE) /* 10 seconds */
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/* See RFC 2637 section 4.4 */
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#define PPTP_ACK_ALPHA(x) ((x) >> 3) /* alpha = 0.125 */
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#define PPTP_ACK_BETA(x) ((x) >> 2) /* beta = 0.25 */
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#define PPTP_ACK_CHI(x) ((x) << 2) /* chi = 4 */
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#define PPTP_ACK_DELTA(x) ((x) << 1) /* delta = 2 */
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#define PPTP_SEQ_DIFF(x,y) ((int32_t)(x) - (int32_t)(y))
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/* We keep packet retransmit and acknowlegement state in this struct */
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struct ng_pptpgre_ackp {
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int32_t ato; /* adaptive time-out value */
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int32_t rtt; /* round trip time estimate */
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int32_t dev; /* deviation estimate */
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u_int16_t xmitWin; /* size of xmit window */
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struct callout_handle sackTimer; /* send ack timer */
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struct callout_handle rackTimer; /* recv ack timer */
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node_p *sackTimerPtr; /* send ack timer pointer */
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node_p *rackTimerPtr; /* recv ack timer pointer */
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u_int32_t winAck; /* seq when xmitWin will grow */
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pptptime_t timeSent[PPTP_XMIT_WIN];
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};
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/* When we recieve a packet, we wait to see if there's an outgoing packet
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we can piggy-back the ACK off of. These parameters determine the mimimum
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and maxmimum length of time we're willing to wait in order to do that. */
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#define PPTP_MAX_ACK_DELAY ((int) (0.25 * PPTP_TIME_SCALE))
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/* Node private data */
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struct ng_pptpgre_private {
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hook_p upper; /* hook to upper layers */
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hook_p lower; /* hook to lower layers */
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struct ng_pptpgre_conf conf; /* configuration info */
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struct ng_pptpgre_ackp ackp; /* packet transmit ack state */
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u_int32_t recvSeq; /* last seq # we rcv'd */
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u_int32_t xmitSeq; /* last seq # we sent */
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u_int32_t recvAck; /* last seq # peer ack'd */
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u_int32_t xmitAck; /* last seq # we ack'd */
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struct timeval startTime; /* time node was created */
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struct ng_pptpgre_stats stats; /* node statistics */
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};
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typedef struct ng_pptpgre_private *priv_p;
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/* Netgraph node methods */
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static ng_constructor_t ng_pptpgre_constructor;
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static ng_rcvmsg_t ng_pptpgre_rcvmsg;
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static ng_shutdown_t ng_pptpgre_rmnode;
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static ng_newhook_t ng_pptpgre_newhook;
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static ng_rcvdata_t ng_pptpgre_rcvdata;
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static ng_disconnect_t ng_pptpgre_disconnect;
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/* Helper functions */
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static int ng_pptpgre_xmit(node_p node, struct mbuf *m, meta_p meta);
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static int ng_pptpgre_recv(node_p node, struct mbuf *m, meta_p meta);
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static void ng_pptpgre_start_send_ack_timer(node_p node, long ackTimeout);
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static void ng_pptpgre_start_recv_ack_timer(node_p node);
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static void ng_pptpgre_recv_ack_timeout(void *arg);
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static void ng_pptpgre_send_ack_timeout(void *arg);
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static void ng_pptpgre_reset(node_p node);
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static pptptime_t ng_pptpgre_time(node_p node);
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/* Parse type for struct ng_pptpgre_conf */
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static const struct ng_parse_struct_info
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ng_pptpgre_conf_type_info = NG_PPTPGRE_CONF_TYPE_INFO;
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static const struct ng_parse_type ng_pptpgre_conf_type = {
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&ng_parse_struct_type,
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&ng_pptpgre_conf_type_info,
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};
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/* Parse type for struct ng_pptpgre_stats */
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static const struct ng_parse_struct_info
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ng_pptpgre_stats_type_info = NG_PPTPGRE_STATS_TYPE_INFO;
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static const struct ng_parse_type ng_pptp_stats_type = {
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&ng_parse_struct_type,
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&ng_pptpgre_stats_type_info
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};
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/* List of commands and how to convert arguments to/from ASCII */
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static const struct ng_cmdlist ng_pptpgre_cmdlist[] = {
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{
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NGM_PPTPGRE_COOKIE,
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NGM_PPTPGRE_SET_CONFIG,
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"setconfig",
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&ng_pptpgre_conf_type,
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NULL
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},
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{
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NGM_PPTPGRE_COOKIE,
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NGM_PPTPGRE_GET_CONFIG,
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"getconfig",
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NULL,
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&ng_pptpgre_conf_type
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},
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{
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NGM_PPTPGRE_COOKIE,
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NGM_PPTPGRE_GET_STATS,
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"getstats",
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NULL,
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&ng_pptp_stats_type
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},
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{
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NGM_PPTPGRE_COOKIE,
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NGM_PPTPGRE_CLR_STATS,
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"clrstats",
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NULL,
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NULL
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},
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{
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NGM_PPTPGRE_COOKIE,
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NGM_PPTPGRE_GETCLR_STATS,
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"getclrstats",
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NULL,
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&ng_pptp_stats_type
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},
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{ 0 }
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};
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/* Node type descriptor */
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static struct ng_type ng_pptpgre_typestruct = {
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NG_VERSION,
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NG_PPTPGRE_NODE_TYPE,
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NULL,
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ng_pptpgre_constructor,
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ng_pptpgre_rcvmsg,
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ng_pptpgre_rmnode,
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ng_pptpgre_newhook,
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NULL,
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NULL,
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ng_pptpgre_rcvdata,
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ng_pptpgre_rcvdata,
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ng_pptpgre_disconnect,
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ng_pptpgre_cmdlist
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};
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NETGRAPH_INIT(pptpgre, &ng_pptpgre_typestruct);
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#define ERROUT(x) do { error = (x); goto done; } while (0)
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/************************************************************************
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NETGRAPH NODE STUFF
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************************************************************************/
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/*
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* Node type constructor
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*/
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static int
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ng_pptpgre_constructor(node_p *nodep)
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{
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priv_p priv;
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int error;
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/* Allocate private structure */
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MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK);
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if (priv == NULL)
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return (ENOMEM);
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bzero(priv, sizeof(*priv));
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/* Call generic node constructor */
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if ((error = ng_make_node_common(&ng_pptpgre_typestruct, nodep))) {
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FREE(priv, M_NETGRAPH);
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return (error);
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}
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(*nodep)->private = priv;
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/* Initialize state */
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callout_handle_init(&priv->ackp.sackTimer);
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callout_handle_init(&priv->ackp.rackTimer);
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/* Done */
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return (0);
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}
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/*
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* Give our OK for a hook to be added.
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*/
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static int
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ng_pptpgre_newhook(node_p node, hook_p hook, const char *name)
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{
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const priv_p priv = node->private;
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hook_p *hookPtr;
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/* Check hook name */
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if (strcmp(name, NG_PPTPGRE_HOOK_UPPER) == 0)
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hookPtr = &priv->upper;
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else if (strcmp(name, NG_PPTPGRE_HOOK_LOWER) == 0)
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hookPtr = &priv->lower;
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else
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return (EINVAL);
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/* See if already connected */
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if (*hookPtr != NULL)
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return (EISCONN);
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/* OK */
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*hookPtr = hook;
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return (0);
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}
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/*
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* Receive a control message.
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*/
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static int
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ng_pptpgre_rcvmsg(node_p node, struct ng_mesg *msg,
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const char *raddr, struct ng_mesg **rptr, hook_p lasthook)
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{
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const priv_p priv = node->private;
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struct ng_mesg *resp = NULL;
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int error = 0;
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switch (msg->header.typecookie) {
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case NGM_PPTPGRE_COOKIE:
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switch (msg->header.cmd) {
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case NGM_PPTPGRE_SET_CONFIG:
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{
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struct ng_pptpgre_conf *const newConf =
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(struct ng_pptpgre_conf *) msg->data;
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/* Check for invalid or illegal config */
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if (msg->header.arglen != sizeof(*newConf))
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ERROUT(EINVAL);
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ng_pptpgre_reset(node); /* reset on configure */
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priv->conf = *newConf;
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break;
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}
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case NGM_PPTPGRE_GET_CONFIG:
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NG_MKRESPONSE(resp, msg, sizeof(priv->conf), M_NOWAIT);
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if (resp == NULL)
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ERROUT(ENOMEM);
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bcopy(&priv->conf, resp->data, sizeof(priv->conf));
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break;
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case NGM_PPTPGRE_GET_STATS:
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case NGM_PPTPGRE_CLR_STATS:
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case NGM_PPTPGRE_GETCLR_STATS:
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{
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if (msg->header.cmd != NGM_PPTPGRE_CLR_STATS) {
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NG_MKRESPONSE(resp, msg,
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sizeof(priv->stats), M_NOWAIT);
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if (resp == NULL)
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ERROUT(ENOMEM);
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bcopy(&priv->stats,
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resp->data, sizeof(priv->stats));
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}
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if (msg->header.cmd != NGM_PPTPGRE_GET_STATS)
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bzero(&priv->stats, sizeof(priv->stats));
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break;
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}
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default:
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error = EINVAL;
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break;
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}
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break;
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default:
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error = EINVAL;
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break;
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}
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if (rptr)
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*rptr = resp;
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else if (resp)
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FREE(resp, M_NETGRAPH);
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done:
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FREE(msg, M_NETGRAPH);
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return (error);
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}
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/*
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* Receive incoming data on a hook.
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*/
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static int
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ng_pptpgre_rcvdata(hook_p hook, struct mbuf *m, meta_p meta,
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struct mbuf **ret_m, meta_p *ret_meta)
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{
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const node_p node = hook->node;
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const priv_p priv = node->private;
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/* If not configured, reject */
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if (!priv->conf.enabled) {
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NG_FREE_DATA(m, meta);
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return (ENXIO);
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}
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/* Treat as xmit or recv data */
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if (hook == priv->upper)
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return ng_pptpgre_xmit(node, m, meta);
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if (hook == priv->lower)
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return ng_pptpgre_recv(node, m, meta);
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panic("%s: weird hook", __FUNCTION__);
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}
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/*
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* Destroy node
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*/
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static int
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ng_pptpgre_rmnode(node_p node)
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{
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const priv_p priv = node->private;
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/* Reset node */
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ng_pptpgre_reset(node);
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/* Take down netgraph node */
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node->flags |= NG_INVALID;
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ng_cutlinks(node);
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ng_unname(node);
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bzero(priv, sizeof(*priv));
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FREE(priv, M_NETGRAPH);
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node->private = NULL;
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ng_unref(node);
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return (0);
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}
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/*
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* Hook disconnection
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*/
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static int
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ng_pptpgre_disconnect(hook_p hook)
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{
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const node_p node = hook->node;
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const priv_p priv = node->private;
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/* Zero out hook pointer */
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if (hook == priv->upper)
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priv->upper = NULL;
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else if (hook == priv->lower)
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priv->lower = NULL;
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else
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panic("%s: unknown hook", __FUNCTION__);
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/* Go away if no longer connected to anything */
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if (node->numhooks == 0)
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ng_rmnode(node);
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return (0);
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}
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/*************************************************************************
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TRANSMIT AND RECEIVE FUNCTIONS
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*************************************************************************/
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/*
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* Transmit an outgoing frame, or just an ack if m is NULL.
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*/
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static int
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ng_pptpgre_xmit(node_p node, struct mbuf *m, meta_p meta)
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{
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const priv_p priv = node->private;
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struct ng_pptpgre_ackp *const a = &priv->ackp;
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u_char buf[sizeof(struct greheader) + 2 * sizeof(u_int32_t)];
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struct greheader *const gre = (struct greheader *)buf;
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int grelen, error;
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/* Check if there's data */
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if (m != NULL) {
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/* Is our transmit window full? */
|
|
if ((u_int32_t)PPTP_SEQ_DIFF(priv->xmitSeq, priv->recvAck)
|
|
>= a->xmitWin) {
|
|
priv->stats.xmitDrops++;
|
|
NG_FREE_DATA(m, meta);
|
|
return (ENOBUFS);
|
|
}
|
|
|
|
/* Sanity check frame length */
|
|
if (m != NULL && m->m_pkthdr.len > PPTP_MAX_PAYLOAD) {
|
|
priv->stats.xmitTooBig++;
|
|
NG_FREE_DATA(m, meta);
|
|
return (EMSGSIZE);
|
|
}
|
|
} else
|
|
priv->stats.xmitLoneAcks++;
|
|
|
|
/* Build GRE header */
|
|
((u_int32_t *) gre)[0] = htonl(PPTP_INIT_VALUE);
|
|
gre->length = (m != NULL) ? htons((u_short)m->m_pkthdr.len) : 0;
|
|
gre->cid = htons(priv->conf.peerCid);
|
|
|
|
/* Include sequence number if packet contains any data */
|
|
if (m != NULL) {
|
|
gre->hasSeq = 1;
|
|
a->timeSent[priv->xmitSeq - priv->recvAck]
|
|
= ng_pptpgre_time(node);
|
|
priv->xmitSeq++;
|
|
gre->data[0] = htonl(priv->xmitSeq);
|
|
if (priv->xmitSeq == priv->recvAck + 1)
|
|
ng_pptpgre_start_recv_ack_timer(node);
|
|
}
|
|
|
|
/* Include acknowledgement (and stop send ack timer) if needed */
|
|
if (PPTP_SEQ_DIFF(priv->xmitAck, priv->recvSeq) < 0) {
|
|
gre->hasAck = 1;
|
|
priv->xmitAck = priv->recvSeq;
|
|
gre->data[gre->hasSeq] = htonl(priv->xmitAck);
|
|
a->sackTimerPtr = NULL;
|
|
}
|
|
|
|
/* Prepend GRE header to outgoing frame */
|
|
grelen = sizeof(*gre) + sizeof(u_int32_t) * (gre->hasSeq + gre->hasAck);
|
|
if (m == NULL) {
|
|
MGETHDR(m, M_DONTWAIT, MT_DATA);
|
|
if (m == NULL) {
|
|
NG_FREE_META(meta);
|
|
return (ENOBUFS);
|
|
}
|
|
m->m_len = m->m_pkthdr.len = grelen;
|
|
m->m_pkthdr.rcvif = NULL;
|
|
} else {
|
|
M_PREPEND(m, grelen, M_NOWAIT);
|
|
if (m == NULL || (m->m_len < grelen
|
|
&& (m = m_pullup(m, grelen)) == NULL)) {
|
|
NG_FREE_META(meta);
|
|
return (ENOBUFS);
|
|
}
|
|
}
|
|
bcopy(gre, mtod(m, u_char *), grelen);
|
|
|
|
/* Update stats */
|
|
priv->stats.xmitPackets++;
|
|
priv->stats.xmitOctets += m->m_pkthdr.len;
|
|
|
|
/* Deliver packet */
|
|
NG_SEND_DATA(error, priv->lower, m, meta);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Handle an incoming packet. The packet includes the IP header.
|
|
*/
|
|
static int
|
|
ng_pptpgre_recv(node_p node, struct mbuf *m, meta_p meta)
|
|
{
|
|
const priv_p priv = node->private;
|
|
int iphlen, grelen, extralen;
|
|
struct greheader *gre;
|
|
struct ip *ip;
|
|
int error = 0;
|
|
|
|
/* Update stats */
|
|
priv->stats.recvPackets++;
|
|
priv->stats.recvOctets += m->m_pkthdr.len;
|
|
|
|
/* Sanity check packet length */
|
|
if (m->m_pkthdr.len < sizeof(*ip) + sizeof(*gre)) {
|
|
priv->stats.recvRunts++;
|
|
bad:
|
|
NG_FREE_DATA(m, meta);
|
|
return (EINVAL);
|
|
}
|
|
|
|
/* Safely pull up the complete IP+GRE headers */
|
|
if (m->m_len < sizeof(*ip) + sizeof(*gre)
|
|
&& (m = m_pullup(m, sizeof(*ip) + sizeof(*gre))) == NULL) {
|
|
NG_FREE_META(meta);
|
|
return (ENOBUFS);
|
|
}
|
|
ip = mtod(m, struct ip *);
|
|
iphlen = ip->ip_hl << 2;
|
|
if (m->m_len < iphlen + sizeof(*gre)) {
|
|
if ((m = m_pullup(m, iphlen + sizeof(*gre))) == NULL) {
|
|
NG_FREE_META(meta);
|
|
return (ENOBUFS);
|
|
}
|
|
ip = mtod(m, struct ip *);
|
|
}
|
|
gre = (struct greheader *)((u_char *)ip + iphlen);
|
|
grelen = sizeof(*gre) + sizeof(u_int32_t) * (gre->hasSeq + gre->hasAck);
|
|
if (m->m_pkthdr.len < iphlen + grelen) {
|
|
priv->stats.recvRunts++;
|
|
goto bad;
|
|
}
|
|
if (m->m_len < iphlen + grelen) {
|
|
if ((m = m_pullup(m, iphlen + grelen)) == NULL) {
|
|
NG_FREE_META(meta);
|
|
return (ENOBUFS);
|
|
}
|
|
ip = mtod(m, struct ip *);
|
|
gre = (struct greheader *)((u_char *)ip + iphlen);
|
|
}
|
|
|
|
/* Sanity check packet length and GRE header bits */
|
|
extralen = m->m_pkthdr.len
|
|
- (iphlen + grelen + (u_int16_t)ntohs(gre->length));
|
|
if (extralen < 0) {
|
|
priv->stats.recvBadGRE++;
|
|
goto bad;
|
|
}
|
|
if ((ntohl(*((u_int32_t *)gre)) & PPTP_INIT_MASK) != PPTP_INIT_VALUE) {
|
|
priv->stats.recvBadGRE++;
|
|
goto bad;
|
|
}
|
|
if (ntohs(gre->cid) != priv->conf.cid) {
|
|
priv->stats.recvBadCID++;
|
|
goto bad;
|
|
}
|
|
|
|
/* Look for peer ack */
|
|
if (gre->hasAck) {
|
|
struct ng_pptpgre_ackp *const a = &priv->ackp;
|
|
const u_int32_t ack = ntohl(gre->data[gre->hasSeq]);
|
|
const int index = ack - priv->recvAck - 1;
|
|
const long sample = ng_pptpgre_time(node) - a->timeSent[index];
|
|
long diff;
|
|
|
|
/* Sanity check ack value */
|
|
if (PPTP_SEQ_DIFF(ack, priv->xmitSeq) > 0) {
|
|
priv->stats.recvBadAcks++;
|
|
goto badAck; /* we never sent it! */
|
|
}
|
|
if (PPTP_SEQ_DIFF(ack, priv->recvAck) <= 0)
|
|
goto badAck; /* ack already timed out */
|
|
priv->recvAck = ack;
|
|
|
|
/* Update adaptive timeout stuff */
|
|
diff = sample - a->rtt;
|
|
a->rtt += PPTP_ACK_ALPHA(diff);
|
|
if (diff < 0)
|
|
diff = -diff;
|
|
a->dev += PPTP_ACK_BETA(diff - a->dev);
|
|
a->ato = a->rtt + PPTP_ACK_CHI(a->dev);
|
|
if (a->ato > PPTP_MAX_TIMEOUT)
|
|
a->ato = PPTP_MAX_TIMEOUT;
|
|
if (a->ato < PPTP_MIN_TIMEOUT)
|
|
a->ato = PPTP_MIN_TIMEOUT;
|
|
|
|
/* Shift packet transmit times in our transmit window */
|
|
ovbcopy(a->timeSent + index + 1, a->timeSent,
|
|
sizeof(*a->timeSent) * (PPTP_XMIT_WIN - (index + 1)));
|
|
|
|
/* If we sent an entire window, increase window size by one */
|
|
if (PPTP_SEQ_DIFF(ack, a->winAck) >= 0
|
|
&& a->xmitWin < PPTP_XMIT_WIN) {
|
|
a->xmitWin++;
|
|
a->winAck = ack + a->xmitWin;
|
|
}
|
|
|
|
/* Stop/(re)start receive ACK timer as necessary */
|
|
ng_pptpgre_start_recv_ack_timer(node);
|
|
}
|
|
badAck:
|
|
|
|
/* See if frame contains any data */
|
|
if (gre->hasSeq) {
|
|
struct ng_pptpgre_ackp *const a = &priv->ackp;
|
|
const u_int32_t seq = ntohl(gre->data[0]);
|
|
|
|
/* Sanity check sequence number */
|
|
if (PPTP_SEQ_DIFF(seq, priv->recvSeq) <= 0) {
|
|
if (seq == priv->recvSeq)
|
|
priv->stats.recvDuplicates++;
|
|
else
|
|
priv->stats.recvOutOfOrder++;
|
|
goto bad; /* out-of-order or dup */
|
|
}
|
|
priv->recvSeq = seq;
|
|
|
|
/* We need to acknowledge this packet; do it soon... */
|
|
if (a->sackTimerPtr == NULL) {
|
|
long maxWait;
|
|
|
|
/* Take half of the estimated round trip time */
|
|
maxWait = (a->rtt >> 1);
|
|
|
|
/* If too soon, just send one right now */
|
|
if (!priv->conf.enableDelayedAck)
|
|
ng_pptpgre_xmit(node, NULL, NULL);
|
|
else { /* send the ack later */
|
|
if (maxWait > PPTP_MAX_ACK_DELAY)
|
|
maxWait = PPTP_MAX_ACK_DELAY;
|
|
ng_pptpgre_start_send_ack_timer(node, maxWait);
|
|
}
|
|
}
|
|
|
|
/* Trim mbuf down to internal payload */
|
|
m_adj(m, iphlen + grelen);
|
|
if (extralen > 0)
|
|
m_adj(m, -extralen);
|
|
|
|
/* Deliver frame to upper layers */
|
|
NG_SEND_DATA(error, priv->upper, m, meta);
|
|
} else {
|
|
priv->stats.recvLoneAcks++;
|
|
NG_FREE_DATA(m, meta); /* no data to deliver */
|
|
}
|
|
return (error);
|
|
}
|
|
|
|
/*************************************************************************
|
|
TIMER RELATED FUNCTIONS
|
|
*************************************************************************/
|
|
|
|
/*
|
|
* Start a timer for the peer's acknowledging our oldest unacknowledged
|
|
* sequence number. If we get an ack for this sequence number before
|
|
* the timer goes off, we cancel the timer. Resets currently running
|
|
* recv ack timer, if any.
|
|
*/
|
|
static void
|
|
ng_pptpgre_start_recv_ack_timer(node_p node)
|
|
{
|
|
const priv_p priv = node->private;
|
|
struct ng_pptpgre_ackp *const a = &priv->ackp;
|
|
int remain;
|
|
|
|
/* "Stop" current recv ack timer, if any */
|
|
a->rackTimerPtr = NULL;
|
|
|
|
/* Are we waiting for an acknowlegement? */
|
|
if (priv->recvAck == priv->xmitSeq)
|
|
return;
|
|
|
|
/* Compute how long until oldest unack'd packet times out,
|
|
and reset the timer to that time. */
|
|
remain = (a->timeSent[0] + a->ato) - ng_pptpgre_time(node);
|
|
if (remain < 0)
|
|
remain = 0;
|
|
|
|
/* Start new timer */
|
|
MALLOC(a->rackTimerPtr, node_p *, sizeof(node_p), M_NETGRAPH, M_NOWAIT);
|
|
if (a->rackTimerPtr == NULL)
|
|
return; /* XXX potential hang here */
|
|
*a->rackTimerPtr = node; /* insures the correct timeout event */
|
|
node->refs++;
|
|
a->rackTimer = timeout(ng_pptpgre_recv_ack_timeout,
|
|
a->rackTimerPtr, remain * hz / PPTP_TIME_SCALE);
|
|
}
|
|
|
|
/*
|
|
* The peer has failed to acknowledge the oldest unacknowledged sequence
|
|
* number within the time allotted. Update our adaptive timeout parameters
|
|
* and reset/restart the recv ack timer.
|
|
*/
|
|
static void
|
|
ng_pptpgre_recv_ack_timeout(void *arg)
|
|
{
|
|
int s = splnet();
|
|
const node_p node = *((node_p *)arg);
|
|
const priv_p priv = node->private;
|
|
struct ng_pptpgre_ackp *const a = &priv->ackp;
|
|
|
|
/* This complicated stuff is needed to avoid race conditions */
|
|
FREE(arg, M_NETGRAPH);
|
|
KASSERT(node->refs > 0, ("%s: no refs", __FUNCTION__));
|
|
if ((node->flags & NG_INVALID) != 0) { /* shutdown race condition */
|
|
ng_unref(node);
|
|
splx(s);
|
|
return;
|
|
}
|
|
ng_unref(node);
|
|
if (arg != a->rackTimerPtr) { /* timer stopped race condition */
|
|
splx(s);
|
|
return;
|
|
}
|
|
a->rackTimerPtr = NULL;
|
|
|
|
/* Update adaptive timeout stuff */
|
|
priv->stats.recvAckTimeouts++;
|
|
a->rtt = PPTP_ACK_DELTA(a->rtt);
|
|
a->ato = a->rtt + PPTP_ACK_CHI(a->dev);
|
|
if (a->ato > PPTP_MAX_TIMEOUT)
|
|
a->ato = PPTP_MAX_TIMEOUT;
|
|
if (a->ato < PPTP_MIN_TIMEOUT)
|
|
a->ato = PPTP_MIN_TIMEOUT;
|
|
|
|
/* Reset ack and sliding window */
|
|
priv->recvAck = priv->xmitSeq; /* pretend we got the ack */
|
|
a->xmitWin = (a->xmitWin + 1) / 2; /* shrink transmit window */
|
|
a->winAck = priv->recvAck + a->xmitWin; /* reset win expand time */
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* Start the send ack timer. This assumes the timer is not
|
|
* already running.
|
|
*/
|
|
static void
|
|
ng_pptpgre_start_send_ack_timer(node_p node, long ackTimeout)
|
|
{
|
|
const priv_p priv = node->private;
|
|
struct ng_pptpgre_ackp *const a = &priv->ackp;
|
|
|
|
/* Start new timer */
|
|
KASSERT(a->sackTimerPtr == NULL, ("%s: sackTimer", __FUNCTION__));
|
|
MALLOC(a->sackTimerPtr, node_p *, sizeof(node_p), M_NETGRAPH, M_NOWAIT);
|
|
if (a->sackTimerPtr == NULL)
|
|
return; /* XXX potential hang here */
|
|
*a->sackTimerPtr = node;
|
|
node->refs++;
|
|
a->sackTimer = timeout(ng_pptpgre_send_ack_timeout,
|
|
a->sackTimerPtr, ackTimeout * hz / PPTP_TIME_SCALE);
|
|
}
|
|
|
|
/*
|
|
* We've waited as long as we're willing to wait before sending an
|
|
* acknowledgement to the peer for received frames. We had hoped to
|
|
* be able to piggy back our acknowledgement on an outgoing data frame,
|
|
* but apparently there haven't been any since. So send the ack now.
|
|
*/
|
|
static void
|
|
ng_pptpgre_send_ack_timeout(void *arg)
|
|
{
|
|
int s = splnet();
|
|
const node_p node = *((node_p *)arg);
|
|
const priv_p priv = node->private;
|
|
struct ng_pptpgre_ackp *const a = &priv->ackp;
|
|
|
|
/* This complicated stuff is needed to avoid race conditions */
|
|
FREE(arg, M_NETGRAPH);
|
|
KASSERT(node->refs > 0, ("%s: no refs", __FUNCTION__));
|
|
if ((node->flags & NG_INVALID) != 0) { /* shutdown race condition */
|
|
ng_unref(node);
|
|
splx(s);
|
|
return;
|
|
}
|
|
ng_unref(node);
|
|
if (a->sackTimerPtr != arg) { /* timer stopped race condition */
|
|
splx(s);
|
|
return;
|
|
}
|
|
a->sackTimerPtr = NULL;
|
|
|
|
/* Send a frame with an ack but no payload */
|
|
ng_pptpgre_xmit(node, NULL, NULL);
|
|
splx(s);
|
|
}
|
|
|
|
/*************************************************************************
|
|
MISC FUNCTIONS
|
|
*************************************************************************/
|
|
|
|
/*
|
|
* Reset state
|
|
*/
|
|
static void
|
|
ng_pptpgre_reset(node_p node)
|
|
{
|
|
const priv_p priv = node->private;
|
|
struct ng_pptpgre_ackp *const a = &priv->ackp;
|
|
|
|
/* Reset adaptive timeout state */
|
|
a->ato = PPTP_MAX_TIMEOUT;
|
|
a->rtt = priv->conf.peerPpd * PPTP_TIME_SCALE / 10; /* ppd in 10ths */
|
|
if (a->rtt < PPTP_MIN_RTT)
|
|
a->rtt = PPTP_MIN_RTT;
|
|
a->dev = 0;
|
|
a->xmitWin = (priv->conf.recvWin + 1) / 2;
|
|
if (a->xmitWin < 2) /* often the first packet is lost */
|
|
a->xmitWin = 2; /* because the peer isn't ready */
|
|
if (a->xmitWin > PPTP_XMIT_WIN)
|
|
a->xmitWin = PPTP_XMIT_WIN;
|
|
a->winAck = a->xmitWin;
|
|
|
|
/* Reset sequence numbers */
|
|
priv->recvSeq = ~0;
|
|
priv->recvAck = ~0;
|
|
priv->xmitSeq = ~0;
|
|
priv->xmitAck = ~0;
|
|
|
|
/* Reset start time */
|
|
getmicrouptime(&priv->startTime);
|
|
|
|
/* Reset stats */
|
|
bzero(&priv->stats, sizeof(priv->stats));
|
|
|
|
/* "Stop" timers */
|
|
a->sackTimerPtr = NULL;
|
|
a->rackTimerPtr = NULL;
|
|
}
|
|
|
|
/*
|
|
* Return the current time scaled & translated to our internally used format.
|
|
*/
|
|
static pptptime_t
|
|
ng_pptpgre_time(node_p node)
|
|
{
|
|
const priv_p priv = node->private;
|
|
struct timeval tv;
|
|
|
|
getmicrouptime(&tv);
|
|
if (tv.tv_sec < priv->startTime.tv_sec
|
|
|| (tv.tv_sec == priv->startTime.tv_sec
|
|
&& tv.tv_usec < priv->startTime.tv_usec))
|
|
return (0);
|
|
timevalsub(&tv, &priv->startTime);
|
|
tv.tv_sec *= PPTP_TIME_SCALE;
|
|
tv.tv_usec /= 1000000 / PPTP_TIME_SCALE;
|
|
return(tv.tv_sec + tv.tv_usec);
|
|
}
|
|
|