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627 lines
16 KiB
C
627 lines
16 KiB
C
/*
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* ng_async.c
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*/
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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@freebsd.org>
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* $Whistle: ng_async.c,v 1.17 1999/11/01 09:24:51 julian Exp $
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*/
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/*
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* This node type implements a PPP style sync <-> async converter.
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* See RFC 1661 for details of how asynchronous encoding works.
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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/mbuf.h>
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#include <sys/malloc.h>
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#include <sys/errno.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_async.h>
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#include <netgraph/ng_parse.h>
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#include <net/ppp_defs.h>
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#ifdef NG_SEPARATE_MALLOC
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static MALLOC_DEFINE(M_NETGRAPH_ASYNC, "netgraph_async", "netgraph async node");
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#else
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#define M_NETGRAPH_ASYNC M_NETGRAPH
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#endif
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/* Async decode state */
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#define MODE_HUNT 0
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#define MODE_NORMAL 1
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#define MODE_ESC 2
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/* Private data structure */
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struct ng_async_private {
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node_p node; /* Our node */
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hook_p async; /* Asynchronous side */
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hook_p sync; /* Synchronous side */
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u_char amode; /* Async hunt/esape mode */
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u_int16_t fcs; /* Decoded async FCS (so far) */
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u_char *abuf; /* Buffer to encode sync into */
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u_char *sbuf; /* Buffer to decode async into */
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u_int slen; /* Length of data in sbuf */
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long lasttime; /* Time of last async packet sent */
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struct ng_async_cfg cfg; /* Configuration */
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struct ng_async_stat stats; /* Statistics */
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};
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typedef struct ng_async_private *sc_p;
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/* Useful macros */
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#define ASYNC_BUF_SIZE(smru) (2 * (smru) + 10)
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#define SYNC_BUF_SIZE(amru) ((amru) + 10)
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#define ERROUT(x) do { error = (x); goto done; } while (0)
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/* Netgraph methods */
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static ng_constructor_t nga_constructor;
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static ng_rcvdata_t nga_rcvdata;
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static ng_rcvmsg_t nga_rcvmsg;
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static ng_shutdown_t nga_shutdown;
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static ng_newhook_t nga_newhook;
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static ng_disconnect_t nga_disconnect;
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/* Helper stuff */
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static int nga_rcv_sync(const sc_p sc, item_p item);
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static int nga_rcv_async(const sc_p sc, item_p item);
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/* Parse type for struct ng_async_cfg */
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static const struct ng_parse_struct_field nga_config_type_fields[]
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= NG_ASYNC_CONFIG_TYPE_INFO;
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static const struct ng_parse_type nga_config_type = {
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&ng_parse_struct_type,
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&nga_config_type_fields
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};
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/* Parse type for struct ng_async_stat */
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static const struct ng_parse_struct_field nga_stats_type_fields[]
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= NG_ASYNC_STATS_TYPE_INFO;
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static const struct ng_parse_type nga_stats_type = {
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&ng_parse_struct_type,
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&nga_stats_type_fields
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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 nga_cmdlist[] = {
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{
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NGM_ASYNC_COOKIE,
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NGM_ASYNC_CMD_SET_CONFIG,
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"setconfig",
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&nga_config_type,
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NULL
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},
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{
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NGM_ASYNC_COOKIE,
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NGM_ASYNC_CMD_GET_CONFIG,
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"getconfig",
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NULL,
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&nga_config_type
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},
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{
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NGM_ASYNC_COOKIE,
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NGM_ASYNC_CMD_GET_STATS,
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"getstats",
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NULL,
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&nga_stats_type
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},
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{
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NGM_ASYNC_COOKIE,
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NGM_ASYNC_CMD_CLR_STATS,
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"clrstats",
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&nga_stats_type,
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NULL
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},
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{ 0 }
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};
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/* Define the netgraph node type */
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static struct ng_type typestruct = {
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.version = NG_ABI_VERSION,
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.name = NG_ASYNC_NODE_TYPE,
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.constructor = nga_constructor,
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.rcvmsg = nga_rcvmsg,
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.shutdown = nga_shutdown,
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.newhook = nga_newhook,
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.rcvdata = nga_rcvdata,
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.disconnect = nga_disconnect,
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.cmdlist = nga_cmdlist
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};
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NETGRAPH_INIT(async, &typestruct);
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/* CRC table */
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static const u_int16_t fcstab[];
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/******************************************************************
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NETGRAPH NODE METHODS
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******************************************************************/
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/*
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* Initialize a new node
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*/
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static int
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nga_constructor(node_p node)
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{
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sc_p sc;
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sc = malloc(sizeof(*sc), M_NETGRAPH_ASYNC, M_WAITOK | M_ZERO);
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sc->amode = MODE_HUNT;
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sc->cfg.accm = ~0;
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sc->cfg.amru = NG_ASYNC_DEFAULT_MRU;
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sc->cfg.smru = NG_ASYNC_DEFAULT_MRU;
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sc->abuf = malloc(ASYNC_BUF_SIZE(sc->cfg.smru),
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M_NETGRAPH_ASYNC, M_WAITOK);
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sc->sbuf = malloc(SYNC_BUF_SIZE(sc->cfg.amru),
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M_NETGRAPH_ASYNC, M_WAITOK);
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NG_NODE_SET_PRIVATE(node, sc);
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sc->node = node;
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return (0);
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}
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/*
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* Reserve a hook for a pending connection
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*/
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static int
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nga_newhook(node_p node, hook_p hook, const char *name)
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{
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const sc_p sc = NG_NODE_PRIVATE(node);
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hook_p *hookp;
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if (!strcmp(name, NG_ASYNC_HOOK_ASYNC)) {
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/*
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* We use a static buffer here so only one packet
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* at a time can be allowed to travel in this direction.
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* Force Writer semantics.
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*/
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NG_HOOK_FORCE_WRITER(hook);
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hookp = &sc->async;
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} else if (!strcmp(name, NG_ASYNC_HOOK_SYNC)) {
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/*
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* We use a static state here so only one packet
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* at a time can be allowed to travel in this direction.
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* Force Writer semantics.
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* Since we set this for both directions
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* we might as well set it for the whole node
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* bit I haven;t done that (yet).
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*/
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NG_HOOK_FORCE_WRITER(hook);
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hookp = &sc->sync;
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} else {
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return (EINVAL);
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}
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if (*hookp) /* actually can't happen I think [JRE] */
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return (EISCONN);
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*hookp = hook;
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return (0);
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}
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/*
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* Receive incoming data
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*/
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static int
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nga_rcvdata(hook_p hook, item_p item)
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{
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const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
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if (hook == sc->sync)
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return (nga_rcv_sync(sc, item));
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if (hook == sc->async)
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return (nga_rcv_async(sc, item));
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panic("%s", __func__);
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}
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/*
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* Receive incoming control message
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*/
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static int
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nga_rcvmsg(node_p node, item_p item, hook_p lasthook)
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{
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const sc_p sc = NG_NODE_PRIVATE(node);
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struct ng_mesg *resp = NULL;
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int error = 0;
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struct ng_mesg *msg;
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NGI_GET_MSG(item, msg);
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switch (msg->header.typecookie) {
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case NGM_ASYNC_COOKIE:
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switch (msg->header.cmd) {
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case NGM_ASYNC_CMD_GET_STATS:
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NG_MKRESPONSE(resp, msg, sizeof(sc->stats), M_NOWAIT);
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if (resp == NULL)
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ERROUT(ENOMEM);
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*((struct ng_async_stat *) resp->data) = sc->stats;
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break;
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case NGM_ASYNC_CMD_CLR_STATS:
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bzero(&sc->stats, sizeof(sc->stats));
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break;
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case NGM_ASYNC_CMD_SET_CONFIG:
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{
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struct ng_async_cfg *const cfg =
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(struct ng_async_cfg *) msg->data;
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u_char *buf;
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if (msg->header.arglen != sizeof(*cfg))
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ERROUT(EINVAL);
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if (cfg->amru < NG_ASYNC_MIN_MRU
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|| cfg->amru > NG_ASYNC_MAX_MRU
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|| cfg->smru < NG_ASYNC_MIN_MRU
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|| cfg->smru > NG_ASYNC_MAX_MRU)
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ERROUT(EINVAL);
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cfg->enabled = !!cfg->enabled; /* normalize */
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if (cfg->smru > sc->cfg.smru) { /* reallocate buffer */
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buf = malloc(ASYNC_BUF_SIZE(cfg->smru),
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M_NETGRAPH_ASYNC, M_NOWAIT);
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if (!buf)
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ERROUT(ENOMEM);
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free(sc->abuf, M_NETGRAPH_ASYNC);
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sc->abuf = buf;
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}
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if (cfg->amru > sc->cfg.amru) { /* reallocate buffer */
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buf = malloc(SYNC_BUF_SIZE(cfg->amru),
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M_NETGRAPH_ASYNC, M_NOWAIT);
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if (!buf)
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ERROUT(ENOMEM);
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free(sc->sbuf, M_NETGRAPH_ASYNC);
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sc->sbuf = buf;
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sc->amode = MODE_HUNT;
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sc->slen = 0;
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}
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if (!cfg->enabled) {
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sc->amode = MODE_HUNT;
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sc->slen = 0;
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}
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sc->cfg = *cfg;
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break;
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}
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case NGM_ASYNC_CMD_GET_CONFIG:
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NG_MKRESPONSE(resp, msg, sizeof(sc->cfg), M_NOWAIT);
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if (!resp)
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ERROUT(ENOMEM);
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*((struct ng_async_cfg *) resp->data) = sc->cfg;
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break;
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default:
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ERROUT(EINVAL);
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}
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break;
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default:
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ERROUT(EINVAL);
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}
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done:
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NG_RESPOND_MSG(error, node, item, resp);
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NG_FREE_MSG(msg);
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return (error);
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}
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/*
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* Shutdown this node
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*/
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static int
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nga_shutdown(node_p node)
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{
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const sc_p sc = NG_NODE_PRIVATE(node);
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free(sc->abuf, M_NETGRAPH_ASYNC);
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free(sc->sbuf, M_NETGRAPH_ASYNC);
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bzero(sc, sizeof(*sc));
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free(sc, M_NETGRAPH_ASYNC);
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NG_NODE_SET_PRIVATE(node, NULL);
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NG_NODE_UNREF(node);
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return (0);
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}
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/*
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* Lose a hook. When both hooks go away, we disappear.
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*/
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static int
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nga_disconnect(hook_p hook)
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{
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const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
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hook_p *hookp;
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if (hook == sc->async)
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hookp = &sc->async;
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else if (hook == sc->sync)
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hookp = &sc->sync;
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else
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panic("%s", __func__);
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if (!*hookp)
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panic("%s 2", __func__);
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*hookp = NULL;
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bzero(&sc->stats, sizeof(sc->stats));
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sc->lasttime = 0;
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if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
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&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
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ng_rmnode_self(NG_HOOK_NODE(hook));
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return (0);
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}
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/******************************************************************
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INTERNAL HELPER STUFF
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******************************************************************/
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/*
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* Encode a byte into the async buffer
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*/
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static __inline void
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nga_async_add(const sc_p sc, u_int16_t *fcs, u_int32_t accm, int *len, u_char x)
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{
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*fcs = PPP_FCS(*fcs, x);
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if ((x < 32 && ((1 << x) & accm))
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|| (x == PPP_ESCAPE)
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|| (x == PPP_FLAG)) {
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sc->abuf[(*len)++] = PPP_ESCAPE;
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x ^= PPP_TRANS;
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}
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sc->abuf[(*len)++] = x;
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}
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/*
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* Receive incoming synchronous data.
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*/
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static int
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nga_rcv_sync(const sc_p sc, item_p item)
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{
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struct ifnet *rcvif;
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int alen, error = 0;
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struct timeval time;
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u_int16_t fcs, fcs0;
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u_int32_t accm;
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struct mbuf *m;
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#define ADD_BYTE(x) nga_async_add(sc, &fcs, accm, &alen, (x))
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/* Check for bypass mode */
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if (!sc->cfg.enabled) {
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NG_FWD_ITEM_HOOK(error, item, sc->async );
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return (error);
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}
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NGI_GET_M(item, m);
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rcvif = m->m_pkthdr.rcvif;
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/* Get ACCM; special case LCP frames, which use full ACCM */
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accm = sc->cfg.accm;
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if (m->m_pkthdr.len >= 4) {
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static const u_char lcphdr[4] = {
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PPP_ALLSTATIONS,
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PPP_UI,
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(u_char)(PPP_LCP >> 8),
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(u_char)(PPP_LCP & 0xff)
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};
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u_char buf[4];
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m_copydata(m, 0, 4, (caddr_t)buf);
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if (bcmp(buf, &lcphdr, 4) == 0)
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accm = ~0;
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}
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/* Check for overflow */
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if (m->m_pkthdr.len > sc->cfg.smru) {
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sc->stats.syncOverflows++;
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NG_FREE_M(m);
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NG_FREE_ITEM(item);
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return (EMSGSIZE);
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}
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/* Update stats */
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sc->stats.syncFrames++;
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sc->stats.syncOctets += m->m_pkthdr.len;
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/* Initialize async encoded version of input mbuf */
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alen = 0;
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fcs = PPP_INITFCS;
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/* Add beginning sync flag if it's been long enough to need one */
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getmicrotime(&time);
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if (time.tv_sec >= sc->lasttime + 1) {
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sc->abuf[alen++] = PPP_FLAG;
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sc->lasttime = time.tv_sec;
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}
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/* Add packet payload */
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while (m != NULL) {
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while (m->m_len > 0) {
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ADD_BYTE(*mtod(m, u_char *));
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m->m_data++;
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m->m_len--;
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}
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m = m_free(m);
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}
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/* Add checksum and final sync flag */
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fcs0 = fcs;
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ADD_BYTE(~fcs0 & 0xff);
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ADD_BYTE(~fcs0 >> 8);
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sc->abuf[alen++] = PPP_FLAG;
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/* Put frame in an mbuf and ship it off */
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if (!(m = m_devget(sc->abuf, alen, 0, rcvif, NULL))) {
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NG_FREE_ITEM(item);
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error = ENOBUFS;
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} else {
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NG_FWD_NEW_DATA(error, item, sc->async, m);
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}
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return (error);
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}
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/*
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* Receive incoming asynchronous data
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* XXX Technically, we should strip out incoming characters
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* that are in our ACCM. Not sure if this is good or not.
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*/
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static int
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nga_rcv_async(const sc_p sc, item_p item)
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{
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struct ifnet *rcvif;
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int error;
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struct mbuf *m;
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if (!sc->cfg.enabled) {
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NG_FWD_ITEM_HOOK(error, item, sc->sync);
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return (error);
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}
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NGI_GET_M(item, m);
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rcvif = m->m_pkthdr.rcvif;
|
|
while (m) {
|
|
struct mbuf *n;
|
|
|
|
for (; m->m_len > 0; m->m_data++, m->m_len--) {
|
|
u_char ch = *mtod(m, u_char *);
|
|
|
|
sc->stats.asyncOctets++;
|
|
if (ch == PPP_FLAG) { /* Flag overrides everything */
|
|
int skip = 0;
|
|
|
|
/* Check for runts */
|
|
if (sc->slen < 2) {
|
|
if (sc->slen > 0)
|
|
sc->stats.asyncRunts++;
|
|
goto reset;
|
|
}
|
|
|
|
/* Verify CRC */
|
|
if (sc->fcs != PPP_GOODFCS) {
|
|
sc->stats.asyncBadCheckSums++;
|
|
goto reset;
|
|
}
|
|
sc->slen -= 2;
|
|
|
|
/* Strip address and control fields */
|
|
if (sc->slen >= 2
|
|
&& sc->sbuf[0] == PPP_ALLSTATIONS
|
|
&& sc->sbuf[1] == PPP_UI)
|
|
skip = 2;
|
|
|
|
/* Check for frame too big */
|
|
if (sc->slen - skip > sc->cfg.amru) {
|
|
sc->stats.asyncOverflows++;
|
|
goto reset;
|
|
}
|
|
|
|
/* OK, ship it out */
|
|
if ((n = m_devget(sc->sbuf + skip,
|
|
sc->slen - skip, 0, rcvif, NULL))) {
|
|
if (item) { /* sets NULL -> item */
|
|
NG_FWD_NEW_DATA(error, item,
|
|
sc->sync, n);
|
|
} else {
|
|
NG_SEND_DATA_ONLY(error,
|
|
sc->sync ,n);
|
|
}
|
|
}
|
|
sc->stats.asyncFrames++;
|
|
reset:
|
|
sc->amode = MODE_NORMAL;
|
|
sc->fcs = PPP_INITFCS;
|
|
sc->slen = 0;
|
|
continue;
|
|
}
|
|
switch (sc->amode) {
|
|
case MODE_NORMAL:
|
|
if (ch == PPP_ESCAPE) {
|
|
sc->amode = MODE_ESC;
|
|
continue;
|
|
}
|
|
break;
|
|
case MODE_ESC:
|
|
ch ^= PPP_TRANS;
|
|
sc->amode = MODE_NORMAL;
|
|
break;
|
|
case MODE_HUNT:
|
|
default:
|
|
continue;
|
|
}
|
|
|
|
/* Add byte to frame */
|
|
if (sc->slen >= SYNC_BUF_SIZE(sc->cfg.amru)) {
|
|
sc->stats.asyncOverflows++;
|
|
sc->amode = MODE_HUNT;
|
|
sc->slen = 0;
|
|
} else {
|
|
sc->sbuf[sc->slen++] = ch;
|
|
sc->fcs = PPP_FCS(sc->fcs, ch);
|
|
}
|
|
}
|
|
m = m_free(m);
|
|
}
|
|
if (item)
|
|
NG_FREE_ITEM(item);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* CRC table
|
|
*
|
|
* Taken from RFC 1171 Appendix B
|
|
*/
|
|
static const u_int16_t fcstab[256] = {
|
|
0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
|
|
0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
|
|
0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
|
|
0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
|
|
0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
|
|
0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
|
|
0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
|
|
0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
|
|
0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
|
|
0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
|
|
0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
|
|
0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
|
|
0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
|
|
0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
|
|
0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
|
|
0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
|
|
0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
|
|
0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
|
|
0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
|
|
0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
|
|
0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
|
|
0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
|
|
0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
|
|
0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
|
|
0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
|
|
0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
|
|
0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
|
|
0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
|
|
0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
|
|
0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
|
|
0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
|
|
0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
|
|
};
|