The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_ppp.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * SPDX-License-Identifier: BSD-2-Clause AND BSD-2-Clause-FreeBSD
    3  *
    4  * Copyright (c) 1996-2000 Whistle Communications, Inc.
    5  * All rights reserved.
    6  *
    7  * Subject to the following obligations and disclaimer of warranty, use and
    8  * redistribution of this software, in source or object code forms, with or
    9  * without modifications are expressly permitted by Whistle Communications;
   10  * provided, however, that:
   11  * 1. Any and all reproductions of the source or object code must include the
   12  *    copyright notice above and the following disclaimer of warranties; and
   13  * 2. No rights are granted, in any manner or form, to use Whistle
   14  *    Communications, Inc. trademarks, including the mark "WHISTLE
   15  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
   16  *    such appears in the above copyright notice or in the software.
   17  *
   18  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
   19  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
   20  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
   21  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
   22  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
   23  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
   24  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
   25  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
   26  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
   27  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
   28  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
   29  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
   30  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
   31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   32  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   33  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
   34  * OF SUCH DAMAGE.
   35  *
   36  * Copyright (c) 2007 Alexander Motin <mav@alkar.net>
   37  * All rights reserved.
   38  *
   39  * Redistribution and use in source and binary forms, with or without
   40  * modification, are permitted provided that the following conditions
   41  * are met:
   42  * 1. Redistributions of source code must retain the above copyright
   43  *    notice unmodified, this list of conditions, and the following
   44  *    disclaimer.
   45  * 2. Redistributions in binary form must reproduce the above copyright
   46  *    notice, this list of conditions and the following disclaimer in the
   47  *    documentation and/or other materials provided with the distribution.
   48  *
   49  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   59  * SUCH DAMAGE.
   60  *
   61  * Authors: Archie Cobbs <archie@freebsd.org>, Alexander Motin <mav@alkar.net>
   62  *
   63  * $FreeBSD: releng/12.0/sys/netgraph/ng_ppp.c 326272 2017-11-27 15:23:17Z pfg $
   64  * $Whistle: ng_ppp.c,v 1.24 1999/11/01 09:24:52 julian Exp $
   65  */
   66 
   67 /*
   68  * PPP node type data-flow.
   69  *
   70  *       hook      xmit        layer         recv      hook
   71  *              ------------------------------------
   72  *       inet ->                                    -> inet
   73  *       ipv6 ->                                    -> ipv6
   74  *        ipx ->               proto                -> ipx
   75  *      atalk ->                                    -> atalk
   76  *     bypass ->                                    -> bypass
   77  *              -hcomp_xmit()----------proto_recv()-
   78  *     vjc_ip <-                                    <- vjc_ip
   79  *   vjc_comp ->         header compression         -> vjc_comp
   80  * vjc_uncomp ->                                    -> vjc_uncomp
   81  *   vjc_vjip ->
   82  *              -comp_xmit()-----------hcomp_recv()-
   83  *   compress <-            compression             <- decompress
   84  *   compress ->                                    -> decompress
   85  *              -crypt_xmit()-----------comp_recv()-
   86  *    encrypt <-             encryption             <- decrypt
   87  *    encrypt ->                                    -> decrypt
   88  *              -ml_xmit()-------------crypt_recv()-
   89  *                           multilink
   90  *              -link_xmit()--------------ml_recv()-
   91  *      linkX <-               link                 <- linkX
   92  *
   93  */
   94 
   95 #include <sys/param.h>
   96 #include <sys/systm.h>
   97 #include <sys/kernel.h>
   98 #include <sys/limits.h>
   99 #include <sys/time.h>
  100 #include <sys/mbuf.h>
  101 #include <sys/malloc.h>
  102 #include <sys/endian.h>
  103 #include <sys/errno.h>
  104 #include <sys/ctype.h>
  105 
  106 #include <netgraph/ng_message.h>
  107 #include <netgraph/netgraph.h>
  108 #include <netgraph/ng_parse.h>
  109 #include <netgraph/ng_ppp.h>
  110 #include <netgraph/ng_vjc.h>
  111 
  112 #ifdef NG_SEPARATE_MALLOC
  113 static MALLOC_DEFINE(M_NETGRAPH_PPP, "netgraph_ppp", "netgraph ppp node");
  114 #else
  115 #define M_NETGRAPH_PPP M_NETGRAPH
  116 #endif
  117 
  118 #define PROT_VALID(p)           (((p) & 0x0101) == 0x0001)
  119 #define PROT_COMPRESSABLE(p)    (((p) & 0xff00) == 0x0000)
  120 
  121 /* Some PPP protocol numbers we're interested in */
  122 #define PROT_ATALK              0x0029
  123 #define PROT_COMPD              0x00fd
  124 #define PROT_CRYPTD             0x0053
  125 #define PROT_IP                 0x0021
  126 #define PROT_IPV6               0x0057
  127 #define PROT_IPX                0x002b
  128 #define PROT_LCP                0xc021
  129 #define PROT_MP                 0x003d
  130 #define PROT_VJCOMP             0x002d
  131 #define PROT_VJUNCOMP           0x002f
  132 
  133 /* Multilink PPP definitions */
  134 #define MP_INITIAL_SEQ          0               /* per RFC 1990 */
  135 #define MP_MIN_LINK_MRU         32
  136 
  137 #define MP_SHORT_SEQ_MASK       0x00000fff      /* short seq # mask */
  138 #define MP_SHORT_SEQ_HIBIT      0x00000800      /* short seq # high bit */
  139 #define MP_SHORT_FIRST_FLAG     0x00008000      /* first fragment in frame */
  140 #define MP_SHORT_LAST_FLAG      0x00004000      /* last fragment in frame */
  141 
  142 #define MP_LONG_SEQ_MASK        0x00ffffff      /* long seq # mask */
  143 #define MP_LONG_SEQ_HIBIT       0x00800000      /* long seq # high bit */
  144 #define MP_LONG_FIRST_FLAG      0x80000000      /* first fragment in frame */
  145 #define MP_LONG_LAST_FLAG       0x40000000      /* last fragment in frame */
  146 
  147 #define MP_NOSEQ                0x7fffffff      /* impossible sequence number */
  148 
  149 /* Sign extension of MP sequence numbers */
  150 #define MP_SHORT_EXTEND(s)      (((s) & MP_SHORT_SEQ_HIBIT) ?           \
  151                                     ((s) | ~MP_SHORT_SEQ_MASK)          \
  152                                     : ((s) & MP_SHORT_SEQ_MASK))
  153 #define MP_LONG_EXTEND(s)       (((s) & MP_LONG_SEQ_HIBIT) ?            \
  154                                     ((s) | ~MP_LONG_SEQ_MASK)           \
  155                                     : ((s) & MP_LONG_SEQ_MASK))
  156 
  157 /* Comparison of MP sequence numbers. Note: all sequence numbers
  158    except priv->xseq are stored with the sign bit extended. */
  159 #define MP_SHORT_SEQ_DIFF(x,y)  MP_SHORT_EXTEND((x) - (y))
  160 #define MP_LONG_SEQ_DIFF(x,y)   MP_LONG_EXTEND((x) - (y))
  161 
  162 #define MP_RECV_SEQ_DIFF(priv,x,y)                                      \
  163                                 ((priv)->conf.recvShortSeq ?            \
  164                                     MP_SHORT_SEQ_DIFF((x), (y)) :       \
  165                                     MP_LONG_SEQ_DIFF((x), (y)))
  166 
  167 /* Increment receive sequence number */
  168 #define MP_NEXT_RECV_SEQ(priv,seq)                                      \
  169                                 ((priv)->conf.recvShortSeq ?            \
  170                                     MP_SHORT_EXTEND((seq) + 1) :        \
  171                                     MP_LONG_EXTEND((seq) + 1))
  172 
  173 /* Don't fragment transmitted packets to parts smaller than this */
  174 #define MP_MIN_FRAG_LEN         32
  175 
  176 /* Maximum fragment reasssembly queue length */
  177 #define MP_MAX_QUEUE_LEN        128
  178 
  179 /* Fragment queue scanner period */
  180 #define MP_FRAGTIMER_INTERVAL   (hz/2)
  181 
  182 /* Average link overhead. XXX: Should be given by user-level */
  183 #define MP_AVERAGE_LINK_OVERHEAD        16
  184 
  185 /* Keep this equal to ng_ppp_hook_names lower! */
  186 #define HOOK_INDEX_MAX          13
  187 
  188 /* We store incoming fragments this way */
  189 struct ng_ppp_frag {
  190         int                             seq;            /* fragment seq# */
  191         uint8_t                         first;          /* First in packet? */
  192         uint8_t                         last;           /* Last in packet? */
  193         struct timeval                  timestamp;      /* time of reception */
  194         struct mbuf                     *data;          /* Fragment data */
  195         TAILQ_ENTRY(ng_ppp_frag)        f_qent;         /* Fragment queue */
  196 };
  197 
  198 /* Per-link private information */
  199 struct ng_ppp_link {
  200         struct ng_ppp_link_conf conf;           /* link configuration */
  201         struct ng_ppp_link_stat64       stats;  /* link stats */
  202         hook_p                  hook;           /* connection to link data */
  203         int32_t                 seq;            /* highest rec'd seq# - MSEQ */
  204         uint32_t                latency;        /* calculated link latency */
  205         struct timeval          lastWrite;      /* time of last write for MP */
  206         int                     bytesInQueue;   /* bytes in the output queue for MP */
  207 };
  208 
  209 /* Total per-node private information */
  210 struct ng_ppp_private {
  211         struct ng_ppp_bund_conf conf;                   /* bundle config */
  212         struct ng_ppp_link_stat64       bundleStats;    /* bundle stats */
  213         struct ng_ppp_link      links[NG_PPP_MAX_LINKS];/* per-link info */
  214         int32_t                 xseq;                   /* next out MP seq # */
  215         int32_t                 mseq;                   /* min links[i].seq */
  216         uint16_t                activeLinks[NG_PPP_MAX_LINKS];  /* indices */
  217         uint16_t                numActiveLinks;         /* how many links up */
  218         uint16_t                lastLink;               /* for round robin */
  219         uint8_t                 vjCompHooked;           /* VJ comp hooked up? */
  220         uint8_t                 allLinksEqual;          /* all xmit the same? */
  221         hook_p                  hooks[HOOK_INDEX_MAX];  /* non-link hooks */
  222         struct ng_ppp_frag      fragsmem[MP_MAX_QUEUE_LEN]; /* fragments storage */
  223         TAILQ_HEAD(ng_ppp_fraglist, ng_ppp_frag)        /* fragment queue */
  224                                 frags;
  225         TAILQ_HEAD(ng_ppp_fragfreelist, ng_ppp_frag)    /* free fragment queue */
  226                                 fragsfree;
  227         struct callout          fragTimer;              /* fraq queue check */
  228         struct mtx              rmtx;                   /* recv mutex */
  229         struct mtx              xmtx;                   /* xmit mutex */
  230 };
  231 typedef struct ng_ppp_private *priv_p;
  232 
  233 /* Netgraph node methods */
  234 static ng_constructor_t ng_ppp_constructor;
  235 static ng_rcvmsg_t      ng_ppp_rcvmsg;
  236 static ng_shutdown_t    ng_ppp_shutdown;
  237 static ng_newhook_t     ng_ppp_newhook;
  238 static ng_rcvdata_t     ng_ppp_rcvdata;
  239 static ng_disconnect_t  ng_ppp_disconnect;
  240 
  241 static ng_rcvdata_t     ng_ppp_rcvdata_inet;
  242 static ng_rcvdata_t     ng_ppp_rcvdata_inet_fast;
  243 static ng_rcvdata_t     ng_ppp_rcvdata_ipv6;
  244 static ng_rcvdata_t     ng_ppp_rcvdata_ipx;
  245 static ng_rcvdata_t     ng_ppp_rcvdata_atalk;
  246 static ng_rcvdata_t     ng_ppp_rcvdata_bypass;
  247 
  248 static ng_rcvdata_t     ng_ppp_rcvdata_vjc_ip;
  249 static ng_rcvdata_t     ng_ppp_rcvdata_vjc_comp;
  250 static ng_rcvdata_t     ng_ppp_rcvdata_vjc_uncomp;
  251 static ng_rcvdata_t     ng_ppp_rcvdata_vjc_vjip;
  252 
  253 static ng_rcvdata_t     ng_ppp_rcvdata_compress;
  254 static ng_rcvdata_t     ng_ppp_rcvdata_decompress;
  255 
  256 static ng_rcvdata_t     ng_ppp_rcvdata_encrypt;
  257 static ng_rcvdata_t     ng_ppp_rcvdata_decrypt;
  258 
  259 /* We use integer indices to refer to the non-link hooks. */
  260 static const struct {
  261         char *const name;
  262         ng_rcvdata_t *fn;
  263 } ng_ppp_hook_names[] = {
  264 #define HOOK_INDEX_ATALK        0
  265         { NG_PPP_HOOK_ATALK,    ng_ppp_rcvdata_atalk },
  266 #define HOOK_INDEX_BYPASS       1
  267         { NG_PPP_HOOK_BYPASS,   ng_ppp_rcvdata_bypass },
  268 #define HOOK_INDEX_COMPRESS     2
  269         { NG_PPP_HOOK_COMPRESS, ng_ppp_rcvdata_compress },
  270 #define HOOK_INDEX_ENCRYPT      3
  271         { NG_PPP_HOOK_ENCRYPT,  ng_ppp_rcvdata_encrypt },
  272 #define HOOK_INDEX_DECOMPRESS   4
  273         { NG_PPP_HOOK_DECOMPRESS, ng_ppp_rcvdata_decompress },
  274 #define HOOK_INDEX_DECRYPT      5
  275         { NG_PPP_HOOK_DECRYPT,  ng_ppp_rcvdata_decrypt },
  276 #define HOOK_INDEX_INET         6
  277         { NG_PPP_HOOK_INET,     ng_ppp_rcvdata_inet },
  278 #define HOOK_INDEX_IPX          7
  279         { NG_PPP_HOOK_IPX,      ng_ppp_rcvdata_ipx },
  280 #define HOOK_INDEX_VJC_COMP     8
  281         { NG_PPP_HOOK_VJC_COMP, ng_ppp_rcvdata_vjc_comp },
  282 #define HOOK_INDEX_VJC_IP       9
  283         { NG_PPP_HOOK_VJC_IP,   ng_ppp_rcvdata_vjc_ip },
  284 #define HOOK_INDEX_VJC_UNCOMP   10
  285         { NG_PPP_HOOK_VJC_UNCOMP, ng_ppp_rcvdata_vjc_uncomp },
  286 #define HOOK_INDEX_VJC_VJIP     11
  287         { NG_PPP_HOOK_VJC_VJIP, ng_ppp_rcvdata_vjc_vjip },
  288 #define HOOK_INDEX_IPV6         12
  289         { NG_PPP_HOOK_IPV6,     ng_ppp_rcvdata_ipv6 },
  290         { NULL, NULL }
  291 };
  292 
  293 /* Helper functions */
  294 static int      ng_ppp_proto_recv(node_p node, item_p item, uint16_t proto,
  295                     uint16_t linkNum);
  296 static int      ng_ppp_hcomp_xmit(node_p node, item_p item, uint16_t proto);
  297 static int      ng_ppp_hcomp_recv(node_p node, item_p item, uint16_t proto,
  298                     uint16_t linkNum);
  299 static int      ng_ppp_comp_xmit(node_p node, item_p item, uint16_t proto);
  300 static int      ng_ppp_comp_recv(node_p node, item_p item, uint16_t proto,
  301                     uint16_t linkNum);
  302 static int      ng_ppp_crypt_xmit(node_p node, item_p item, uint16_t proto);
  303 static int      ng_ppp_crypt_recv(node_p node, item_p item, uint16_t proto,
  304                     uint16_t linkNum);
  305 static int      ng_ppp_mp_xmit(node_p node, item_p item, uint16_t proto);
  306 static int      ng_ppp_mp_recv(node_p node, item_p item, uint16_t proto,
  307                     uint16_t linkNum);
  308 static int      ng_ppp_link_xmit(node_p node, item_p item, uint16_t proto,
  309                     uint16_t linkNum, int plen);
  310 
  311 static int      ng_ppp_bypass(node_p node, item_p item, uint16_t proto,
  312                     uint16_t linkNum);
  313 
  314 static void     ng_ppp_bump_mseq(node_p node, int32_t new_mseq);
  315 static int      ng_ppp_frag_drop(node_p node);
  316 static int      ng_ppp_check_packet(node_p node);
  317 static void     ng_ppp_get_packet(node_p node, struct mbuf **mp);
  318 static int      ng_ppp_frag_process(node_p node, item_p oitem);
  319 static int      ng_ppp_frag_trim(node_p node);
  320 static void     ng_ppp_frag_timeout(node_p node, hook_p hook, void *arg1,
  321                     int arg2);
  322 static void     ng_ppp_frag_checkstale(node_p node);
  323 static void     ng_ppp_frag_reset(node_p node);
  324 static void     ng_ppp_mp_strategy(node_p node, int len, int *distrib);
  325 static int      ng_ppp_intcmp(void *latency, const void *v1, const void *v2);
  326 static struct mbuf *ng_ppp_addproto(struct mbuf *m, uint16_t proto, int compOK);
  327 static struct mbuf *ng_ppp_cutproto(struct mbuf *m, uint16_t *proto);
  328 static struct mbuf *ng_ppp_prepend(struct mbuf *m, const void *buf, int len);
  329 static int      ng_ppp_config_valid(node_p node,
  330                     const struct ng_ppp_node_conf *newConf);
  331 static void     ng_ppp_update(node_p node, int newConf);
  332 static void     ng_ppp_start_frag_timer(node_p node);
  333 static void     ng_ppp_stop_frag_timer(node_p node);
  334 
  335 /* Parse type for struct ng_ppp_mp_state_type */
  336 static const struct ng_parse_fixedarray_info ng_ppp_rseq_array_info = {
  337         &ng_parse_hint32_type,
  338         NG_PPP_MAX_LINKS
  339 };
  340 static const struct ng_parse_type ng_ppp_rseq_array_type = {
  341         &ng_parse_fixedarray_type,
  342         &ng_ppp_rseq_array_info,
  343 };
  344 static const struct ng_parse_struct_field ng_ppp_mp_state_type_fields[]
  345         = NG_PPP_MP_STATE_TYPE_INFO(&ng_ppp_rseq_array_type);
  346 static const struct ng_parse_type ng_ppp_mp_state_type = {
  347         &ng_parse_struct_type,
  348         &ng_ppp_mp_state_type_fields
  349 };
  350 
  351 /* Parse type for struct ng_ppp_link_conf */
  352 static const struct ng_parse_struct_field ng_ppp_link_type_fields[]
  353         = NG_PPP_LINK_TYPE_INFO;
  354 static const struct ng_parse_type ng_ppp_link_type = {
  355         &ng_parse_struct_type,
  356         &ng_ppp_link_type_fields
  357 };
  358 
  359 /* Parse type for struct ng_ppp_bund_conf */
  360 static const struct ng_parse_struct_field ng_ppp_bund_type_fields[]
  361         = NG_PPP_BUND_TYPE_INFO;
  362 static const struct ng_parse_type ng_ppp_bund_type = {
  363         &ng_parse_struct_type,
  364         &ng_ppp_bund_type_fields
  365 };
  366 
  367 /* Parse type for struct ng_ppp_node_conf */
  368 static const struct ng_parse_fixedarray_info ng_ppp_array_info = {
  369         &ng_ppp_link_type,
  370         NG_PPP_MAX_LINKS
  371 };
  372 static const struct ng_parse_type ng_ppp_link_array_type = {
  373         &ng_parse_fixedarray_type,
  374         &ng_ppp_array_info,
  375 };
  376 static const struct ng_parse_struct_field ng_ppp_conf_type_fields[]
  377         = NG_PPP_CONFIG_TYPE_INFO(&ng_ppp_bund_type, &ng_ppp_link_array_type);
  378 static const struct ng_parse_type ng_ppp_conf_type = {
  379         &ng_parse_struct_type,
  380         &ng_ppp_conf_type_fields
  381 };
  382 
  383 /* Parse type for struct ng_ppp_link_stat */
  384 static const struct ng_parse_struct_field ng_ppp_stats_type_fields[]
  385         = NG_PPP_STATS_TYPE_INFO;
  386 static const struct ng_parse_type ng_ppp_stats_type = {
  387         &ng_parse_struct_type,
  388         &ng_ppp_stats_type_fields
  389 };
  390 
  391 /* Parse type for struct ng_ppp_link_stat64 */
  392 static const struct ng_parse_struct_field ng_ppp_stats64_type_fields[]
  393         = NG_PPP_STATS64_TYPE_INFO;
  394 static const struct ng_parse_type ng_ppp_stats64_type = {
  395         &ng_parse_struct_type,
  396         &ng_ppp_stats64_type_fields
  397 };
  398 
  399 /* List of commands and how to convert arguments to/from ASCII */
  400 static const struct ng_cmdlist ng_ppp_cmds[] = {
  401         {
  402           NGM_PPP_COOKIE,
  403           NGM_PPP_SET_CONFIG,
  404           "setconfig",
  405           &ng_ppp_conf_type,
  406           NULL
  407         },
  408         {
  409           NGM_PPP_COOKIE,
  410           NGM_PPP_GET_CONFIG,
  411           "getconfig",
  412           NULL,
  413           &ng_ppp_conf_type
  414         },
  415         {
  416           NGM_PPP_COOKIE,
  417           NGM_PPP_GET_MP_STATE,
  418           "getmpstate",
  419           NULL,
  420           &ng_ppp_mp_state_type
  421         },
  422         {
  423           NGM_PPP_COOKIE,
  424           NGM_PPP_GET_LINK_STATS,
  425           "getstats",
  426           &ng_parse_int16_type,
  427           &ng_ppp_stats_type
  428         },
  429         {
  430           NGM_PPP_COOKIE,
  431           NGM_PPP_CLR_LINK_STATS,
  432           "clrstats",
  433           &ng_parse_int16_type,
  434           NULL
  435         },
  436         {
  437           NGM_PPP_COOKIE,
  438           NGM_PPP_GETCLR_LINK_STATS,
  439           "getclrstats",
  440           &ng_parse_int16_type,
  441           &ng_ppp_stats_type
  442         },
  443         {
  444           NGM_PPP_COOKIE,
  445           NGM_PPP_GET_LINK_STATS64,
  446           "getstats64",
  447           &ng_parse_int16_type,
  448           &ng_ppp_stats64_type
  449         },
  450         {
  451           NGM_PPP_COOKIE,
  452           NGM_PPP_GETCLR_LINK_STATS64,
  453           "getclrstats64",
  454           &ng_parse_int16_type,
  455           &ng_ppp_stats64_type
  456         },
  457         { 0 }
  458 };
  459 
  460 /* Node type descriptor */
  461 static struct ng_type ng_ppp_typestruct = {
  462         .version =      NG_ABI_VERSION,
  463         .name =         NG_PPP_NODE_TYPE,
  464         .constructor =  ng_ppp_constructor,
  465         .rcvmsg =       ng_ppp_rcvmsg,
  466         .shutdown =     ng_ppp_shutdown,
  467         .newhook =      ng_ppp_newhook,
  468         .rcvdata =      ng_ppp_rcvdata,
  469         .disconnect =   ng_ppp_disconnect,
  470         .cmdlist =      ng_ppp_cmds,
  471 };
  472 NETGRAPH_INIT(ppp, &ng_ppp_typestruct);
  473 
  474 /* Address and control field header */
  475 static const uint8_t ng_ppp_acf[2] = { 0xff, 0x03 };
  476 
  477 /* Maximum time we'll let a complete incoming packet sit in the queue */
  478 static const struct timeval ng_ppp_max_staleness = { 2, 0 };    /* 2 seconds */
  479 
  480 #define ERROUT(x)       do { error = (x); goto done; } while (0)
  481 
  482 /************************************************************************
  483                         NETGRAPH NODE STUFF
  484  ************************************************************************/
  485 
  486 /*
  487  * Node type constructor
  488  */
  489 static int
  490 ng_ppp_constructor(node_p node)
  491 {
  492         priv_p priv;
  493         int i;
  494 
  495         /* Allocate private structure */
  496         priv = malloc(sizeof(*priv), M_NETGRAPH_PPP, M_WAITOK | M_ZERO);
  497 
  498         NG_NODE_SET_PRIVATE(node, priv);
  499 
  500         /* Initialize state */
  501         TAILQ_INIT(&priv->frags);
  502         TAILQ_INIT(&priv->fragsfree);
  503         for (i = 0; i < MP_MAX_QUEUE_LEN; i++)
  504                 TAILQ_INSERT_TAIL(&priv->fragsfree, &priv->fragsmem[i], f_qent);
  505         for (i = 0; i < NG_PPP_MAX_LINKS; i++)
  506                 priv->links[i].seq = MP_NOSEQ;
  507         ng_callout_init(&priv->fragTimer);
  508 
  509         mtx_init(&priv->rmtx, "ng_ppp_recv", NULL, MTX_DEF);
  510         mtx_init(&priv->xmtx, "ng_ppp_xmit", NULL, MTX_DEF);
  511 
  512         /* Done */
  513         return (0);
  514 }
  515 
  516 /*
  517  * Give our OK for a hook to be added
  518  */
  519 static int
  520 ng_ppp_newhook(node_p node, hook_p hook, const char *name)
  521 {
  522         const priv_p priv = NG_NODE_PRIVATE(node);
  523         hook_p *hookPtr = NULL;
  524         int linkNum = -1;
  525         int hookIndex = -1;
  526 
  527         /* Figure out which hook it is */
  528         if (strncmp(name, NG_PPP_HOOK_LINK_PREFIX,      /* a link hook? */
  529             strlen(NG_PPP_HOOK_LINK_PREFIX)) == 0) {
  530                 const char *cp;
  531                 char *eptr;
  532 
  533                 cp = name + strlen(NG_PPP_HOOK_LINK_PREFIX);
  534                 if (!isdigit(*cp) || (cp[0] == '' && cp[1] != '\0'))
  535                         return (EINVAL);
  536                 linkNum = (int)strtoul(cp, &eptr, 10);
  537                 if (*eptr != '\0' || linkNum < 0 || linkNum >= NG_PPP_MAX_LINKS)
  538                         return (EINVAL);
  539                 hookPtr = &priv->links[linkNum].hook;
  540                 hookIndex = ~linkNum;
  541 
  542                 /* See if hook is already connected. */
  543                 if (*hookPtr != NULL)
  544                         return (EISCONN);
  545 
  546                 /* Disallow more than one link unless multilink is enabled. */
  547                 if (priv->links[linkNum].conf.enableLink &&
  548                     !priv->conf.enableMultilink && priv->numActiveLinks >= 1)
  549                         return (ENODEV);
  550 
  551         } else {                                /* must be a non-link hook */
  552                 int i;
  553 
  554                 for (i = 0; ng_ppp_hook_names[i].name != NULL; i++) {
  555                         if (strcmp(name, ng_ppp_hook_names[i].name) == 0) {
  556                                 hookPtr = &priv->hooks[i];
  557                                 hookIndex = i;
  558                                 break;
  559                         }
  560                 }
  561                 if (ng_ppp_hook_names[i].name == NULL)
  562                         return (EINVAL);        /* no such hook */
  563 
  564                 /* See if hook is already connected */
  565                 if (*hookPtr != NULL)
  566                         return (EISCONN);
  567 
  568                 /* Every non-linkX hook have it's own function. */
  569                 NG_HOOK_SET_RCVDATA(hook, ng_ppp_hook_names[i].fn);
  570         }
  571 
  572         /* OK */
  573         *hookPtr = hook;
  574         NG_HOOK_SET_PRIVATE(hook, (void *)(intptr_t)hookIndex);
  575         ng_ppp_update(node, 0);
  576         return (0);
  577 }
  578 
  579 /*
  580  * Receive a control message
  581  */
  582 static int
  583 ng_ppp_rcvmsg(node_p node, item_p item, hook_p lasthook)
  584 {
  585         const priv_p priv = NG_NODE_PRIVATE(node);
  586         struct ng_mesg *resp = NULL;
  587         int error = 0;
  588         struct ng_mesg *msg;
  589 
  590         NGI_GET_MSG(item, msg);
  591         switch (msg->header.typecookie) {
  592         case NGM_PPP_COOKIE:
  593                 switch (msg->header.cmd) {
  594                 case NGM_PPP_SET_CONFIG:
  595                     {
  596                         struct ng_ppp_node_conf *const conf =
  597                             (struct ng_ppp_node_conf *)msg->data;
  598                         int i;
  599 
  600                         /* Check for invalid or illegal config */
  601                         if (msg->header.arglen != sizeof(*conf))
  602                                 ERROUT(EINVAL);
  603                         if (!ng_ppp_config_valid(node, conf))
  604                                 ERROUT(EINVAL);
  605 
  606                         /* Copy config */
  607                         priv->conf = conf->bund;
  608                         for (i = 0; i < NG_PPP_MAX_LINKS; i++)
  609                                 priv->links[i].conf = conf->links[i];
  610                         ng_ppp_update(node, 1);
  611                         break;
  612                     }
  613                 case NGM_PPP_GET_CONFIG:
  614                     {
  615                         struct ng_ppp_node_conf *conf;
  616                         int i;
  617 
  618                         NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT);
  619                         if (resp == NULL)
  620                                 ERROUT(ENOMEM);
  621                         conf = (struct ng_ppp_node_conf *)resp->data;
  622                         conf->bund = priv->conf;
  623                         for (i = 0; i < NG_PPP_MAX_LINKS; i++)
  624                                 conf->links[i] = priv->links[i].conf;
  625                         break;
  626                     }
  627                 case NGM_PPP_GET_MP_STATE:
  628                     {
  629                         struct ng_ppp_mp_state *info;
  630                         int i;
  631 
  632                         NG_MKRESPONSE(resp, msg, sizeof(*info), M_NOWAIT);
  633                         if (resp == NULL)
  634                                 ERROUT(ENOMEM);
  635                         info = (struct ng_ppp_mp_state *)resp->data;
  636                         bzero(info, sizeof(*info));
  637                         for (i = 0; i < NG_PPP_MAX_LINKS; i++) {
  638                                 if (priv->links[i].seq != MP_NOSEQ)
  639                                         info->rseq[i] = priv->links[i].seq;
  640                         }
  641                         info->mseq = priv->mseq;
  642                         info->xseq = priv->xseq;
  643                         break;
  644                     }
  645                 case NGM_PPP_GET_LINK_STATS:
  646                 case NGM_PPP_CLR_LINK_STATS:
  647                 case NGM_PPP_GETCLR_LINK_STATS:
  648                 case NGM_PPP_GET_LINK_STATS64:
  649                 case NGM_PPP_GETCLR_LINK_STATS64:
  650                     {
  651                         struct ng_ppp_link_stat64 *stats;
  652                         uint16_t linkNum;
  653 
  654                         /* Process request. */
  655                         if (msg->header.arglen != sizeof(uint16_t))
  656                                 ERROUT(EINVAL);
  657                         linkNum = *((uint16_t *) msg->data);
  658                         if (linkNum >= NG_PPP_MAX_LINKS
  659                             && linkNum != NG_PPP_BUNDLE_LINKNUM)
  660                                 ERROUT(EINVAL);
  661                         stats = (linkNum == NG_PPP_BUNDLE_LINKNUM) ?
  662                             &priv->bundleStats : &priv->links[linkNum].stats;
  663 
  664                         /* Make 64bit reply. */
  665                         if (msg->header.cmd == NGM_PPP_GET_LINK_STATS64 ||
  666                             msg->header.cmd == NGM_PPP_GETCLR_LINK_STATS64) {
  667                                 NG_MKRESPONSE(resp, msg,
  668                                     sizeof(struct ng_ppp_link_stat64), M_NOWAIT);
  669                                 if (resp == NULL)
  670                                         ERROUT(ENOMEM);
  671                                 bcopy(stats, resp->data, sizeof(*stats));
  672                         } else
  673                         /* Make 32bit reply. */
  674                         if (msg->header.cmd == NGM_PPP_GET_LINK_STATS ||
  675                             msg->header.cmd == NGM_PPP_GETCLR_LINK_STATS) {
  676                                 struct ng_ppp_link_stat *rs;
  677                                 NG_MKRESPONSE(resp, msg,
  678                                     sizeof(struct ng_ppp_link_stat), M_NOWAIT);
  679                                 if (resp == NULL)
  680                                         ERROUT(ENOMEM);
  681                                 rs = (struct ng_ppp_link_stat *)resp->data;
  682                                 /* Truncate 64->32 bits. */
  683                                 rs->xmitFrames = stats->xmitFrames;
  684                                 rs->xmitOctets = stats->xmitOctets;
  685                                 rs->recvFrames = stats->recvFrames;
  686                                 rs->recvOctets = stats->recvOctets;
  687                                 rs->badProtos = stats->badProtos;
  688                                 rs->runts = stats->runts;
  689                                 rs->dupFragments = stats->dupFragments;
  690                                 rs->dropFragments = stats->dropFragments;
  691                         }
  692                         /* Clear stats. */
  693                         if (msg->header.cmd != NGM_PPP_GET_LINK_STATS &&
  694                             msg->header.cmd != NGM_PPP_GET_LINK_STATS64)
  695                                 bzero(stats, sizeof(*stats));
  696                         break;
  697                     }
  698                 default:
  699                         error = EINVAL;
  700                         break;
  701                 }
  702                 break;
  703         case NGM_VJC_COOKIE:
  704             {
  705                 /*
  706                  * Forward it to the vjc node. leave the
  707                  * old return address alone.
  708                  * If we have no hook, let NG_RESPOND_MSG
  709                  * clean up any remaining resources.
  710                  * Because we have no resp, the item will be freed
  711                  * along with anything it references. Don't
  712                  * let msg be freed twice.
  713                  */
  714                 NGI_MSG(item) = msg;    /* put it back in the item */
  715                 msg = NULL;
  716                 if ((lasthook = priv->hooks[HOOK_INDEX_VJC_IP])) {
  717                         NG_FWD_ITEM_HOOK(error, item, lasthook);
  718                 }
  719                 return (error);
  720             }
  721         default:
  722                 error = EINVAL;
  723                 break;
  724         }
  725 done:
  726         NG_RESPOND_MSG(error, node, item, resp);
  727         NG_FREE_MSG(msg);
  728         return (error);
  729 }
  730 
  731 /*
  732  * Destroy node
  733  */
  734 static int
  735 ng_ppp_shutdown(node_p node)
  736 {
  737         const priv_p priv = NG_NODE_PRIVATE(node);
  738 
  739         /* Stop fragment queue timer */
  740         ng_ppp_stop_frag_timer(node);
  741 
  742         /* Take down netgraph node */
  743         ng_ppp_frag_reset(node);
  744         mtx_destroy(&priv->rmtx);
  745         mtx_destroy(&priv->xmtx);
  746         bzero(priv, sizeof(*priv));
  747         free(priv, M_NETGRAPH_PPP);
  748         NG_NODE_SET_PRIVATE(node, NULL);
  749         NG_NODE_UNREF(node);            /* let the node escape */
  750         return (0);
  751 }
  752 
  753 /*
  754  * Hook disconnection
  755  */
  756 static int
  757 ng_ppp_disconnect(hook_p hook)
  758 {
  759         const node_p node = NG_HOOK_NODE(hook);
  760         const priv_p priv = NG_NODE_PRIVATE(node);
  761         const int index = (intptr_t)NG_HOOK_PRIVATE(hook);
  762 
  763         /* Zero out hook pointer */
  764         if (index < 0)
  765                 priv->links[~index].hook = NULL;
  766         else
  767                 priv->hooks[index] = NULL;
  768 
  769         /* Update derived info (or go away if no hooks left). */
  770         if (NG_NODE_NUMHOOKS(node) > 0)
  771                 ng_ppp_update(node, 0);
  772         else if (NG_NODE_IS_VALID(node))
  773                 ng_rmnode_self(node);
  774 
  775         return (0);
  776 }
  777 
  778 /*
  779  * Proto layer
  780  */
  781 
  782 /*
  783  * Receive data on a hook inet.
  784  */
  785 static int
  786 ng_ppp_rcvdata_inet(hook_p hook, item_p item)
  787 {
  788         const node_p node = NG_HOOK_NODE(hook);
  789         const priv_p priv = NG_NODE_PRIVATE(node);
  790 
  791         if (!priv->conf.enableIP) {
  792                 NG_FREE_ITEM(item);
  793                 return (ENXIO);
  794         }
  795         return (ng_ppp_hcomp_xmit(NG_HOOK_NODE(hook), item, PROT_IP));
  796 }
  797 
  798 /*
  799  * Receive data on a hook inet and pass it directly to first link.
  800  */
  801 static int
  802 ng_ppp_rcvdata_inet_fast(hook_p hook, item_p item)
  803 {
  804         const node_p node = NG_HOOK_NODE(hook);
  805         const priv_p priv = NG_NODE_PRIVATE(node);
  806 
  807         return (ng_ppp_link_xmit(node, item, PROT_IP, priv->activeLinks[0],
  808             NGI_M(item)->m_pkthdr.len));
  809 }
  810 
  811 /*
  812  * Receive data on a hook ipv6.
  813  */
  814 static int
  815 ng_ppp_rcvdata_ipv6(hook_p hook, item_p item)
  816 {
  817         const node_p node = NG_HOOK_NODE(hook);
  818         const priv_p priv = NG_NODE_PRIVATE(node);
  819 
  820         if (!priv->conf.enableIPv6) {
  821                 NG_FREE_ITEM(item);
  822                 return (ENXIO);
  823         }
  824         return (ng_ppp_hcomp_xmit(NG_HOOK_NODE(hook), item, PROT_IPV6));
  825 }
  826 
  827 /*
  828  * Receive data on a hook atalk.
  829  */
  830 static int
  831 ng_ppp_rcvdata_atalk(hook_p hook, item_p item)
  832 {
  833         const node_p node = NG_HOOK_NODE(hook);
  834         const priv_p priv = NG_NODE_PRIVATE(node);
  835 
  836         if (!priv->conf.enableAtalk) {
  837                 NG_FREE_ITEM(item);
  838                 return (ENXIO);
  839         }
  840         return (ng_ppp_hcomp_xmit(NG_HOOK_NODE(hook), item, PROT_ATALK));
  841 }
  842 
  843 /*
  844  * Receive data on a hook ipx
  845  */
  846 static int
  847 ng_ppp_rcvdata_ipx(hook_p hook, item_p item)
  848 {
  849         const node_p node = NG_HOOK_NODE(hook);
  850         const priv_p priv = NG_NODE_PRIVATE(node);
  851 
  852         if (!priv->conf.enableIPX) {
  853                 NG_FREE_ITEM(item);
  854                 return (ENXIO);
  855         }
  856         return (ng_ppp_hcomp_xmit(NG_HOOK_NODE(hook), item, PROT_IPX));
  857 }
  858 
  859 /*
  860  * Receive data on a hook bypass
  861  */
  862 static int
  863 ng_ppp_rcvdata_bypass(hook_p hook, item_p item)
  864 {
  865         uint16_t linkNum;
  866         uint16_t proto;
  867         struct mbuf *m;
  868 
  869         NGI_GET_M(item, m);
  870         if (m->m_pkthdr.len < 4) {
  871                 NG_FREE_ITEM(item);
  872                 return (EINVAL);
  873         }
  874         if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
  875                 NG_FREE_ITEM(item);
  876                 return (ENOBUFS);
  877         }
  878         linkNum = be16dec(mtod(m, uint8_t *));
  879         proto = be16dec(mtod(m, uint8_t *) + 2);
  880         m_adj(m, 4);
  881         NGI_M(item) = m;
  882 
  883         if (linkNum == NG_PPP_BUNDLE_LINKNUM)
  884                 return (ng_ppp_hcomp_xmit(NG_HOOK_NODE(hook), item, proto));
  885         else
  886                 return (ng_ppp_link_xmit(NG_HOOK_NODE(hook), item, proto,
  887                     linkNum, 0));
  888 }
  889 
  890 static int
  891 ng_ppp_bypass(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
  892 {
  893         const priv_p priv = NG_NODE_PRIVATE(node);
  894         uint16_t hdr[2];
  895         struct mbuf *m;
  896         int error;
  897 
  898         if (priv->hooks[HOOK_INDEX_BYPASS] == NULL) {
  899             NG_FREE_ITEM(item);
  900             return (ENXIO);
  901         }
  902 
  903         /* Add 4-byte bypass header. */
  904         hdr[0] = htons(linkNum);
  905         hdr[1] = htons(proto);
  906 
  907         NGI_GET_M(item, m);
  908         if ((m = ng_ppp_prepend(m, &hdr, 4)) == NULL) {
  909                 NG_FREE_ITEM(item);
  910                 return (ENOBUFS);
  911         }
  912         NGI_M(item) = m;
  913 
  914         /* Send packet out hook. */
  915         NG_FWD_ITEM_HOOK(error, item, priv->hooks[HOOK_INDEX_BYPASS]);
  916         return (error);
  917 }
  918 
  919 static int
  920 ng_ppp_proto_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
  921 {
  922         const priv_p priv = NG_NODE_PRIVATE(node);
  923         hook_p outHook = NULL;
  924         int error;
  925 #ifdef ALIGNED_POINTER
  926         struct mbuf *m, *n;
  927 
  928         NGI_GET_M(item, m);
  929         if (!ALIGNED_POINTER(mtod(m, caddr_t), uint32_t)) {
  930                 n = m_defrag(m, M_NOWAIT);
  931                 if (n == NULL) {
  932                         m_freem(m);
  933                         NG_FREE_ITEM(item);
  934                         return (ENOBUFS);
  935                 }
  936                 m = n;
  937         }
  938         NGI_M(item) = m;
  939 #endif /* ALIGNED_POINTER */
  940         switch (proto) {
  941             case PROT_IP:
  942                 if (priv->conf.enableIP)
  943                     outHook = priv->hooks[HOOK_INDEX_INET];
  944                 break;
  945             case PROT_IPV6:
  946                 if (priv->conf.enableIPv6)
  947                     outHook = priv->hooks[HOOK_INDEX_IPV6];
  948                 break;
  949             case PROT_ATALK:
  950                 if (priv->conf.enableAtalk)
  951                     outHook = priv->hooks[HOOK_INDEX_ATALK];
  952                 break;
  953             case PROT_IPX:
  954                 if (priv->conf.enableIPX)
  955                     outHook = priv->hooks[HOOK_INDEX_IPX];
  956                 break;
  957         }
  958 
  959         if (outHook == NULL)
  960                 return (ng_ppp_bypass(node, item, proto, linkNum));
  961 
  962         /* Send packet out hook. */
  963         NG_FWD_ITEM_HOOK(error, item, outHook);
  964         return (error);
  965 }
  966 
  967 /*
  968  * Header compression layer
  969  */
  970 
  971 static int
  972 ng_ppp_hcomp_xmit(node_p node, item_p item, uint16_t proto)
  973 {
  974         const priv_p priv = NG_NODE_PRIVATE(node);
  975 
  976         if (proto == PROT_IP &&
  977             priv->conf.enableVJCompression &&
  978             priv->vjCompHooked) {
  979                 int error;
  980 
  981                 /* Send packet out hook. */
  982                 NG_FWD_ITEM_HOOK(error, item, priv->hooks[HOOK_INDEX_VJC_IP]);
  983                 return (error);
  984         }
  985 
  986         return (ng_ppp_comp_xmit(node, item, proto));
  987 }
  988 
  989 /*
  990  * Receive data on a hook vjc_comp.
  991  */
  992 static int
  993 ng_ppp_rcvdata_vjc_comp(hook_p hook, item_p item)
  994 {
  995         const node_p node = NG_HOOK_NODE(hook);
  996         const priv_p priv = NG_NODE_PRIVATE(node);
  997 
  998         if (!priv->conf.enableVJCompression) {
  999                 NG_FREE_ITEM(item);
 1000                 return (ENXIO);
 1001         }
 1002         return (ng_ppp_comp_xmit(node, item, PROT_VJCOMP));
 1003 }
 1004 
 1005 /*
 1006  * Receive data on a hook vjc_uncomp.
 1007  */
 1008 static int
 1009 ng_ppp_rcvdata_vjc_uncomp(hook_p hook, item_p item)
 1010 {
 1011         const node_p node = NG_HOOK_NODE(hook);
 1012         const priv_p priv = NG_NODE_PRIVATE(node);
 1013 
 1014         if (!priv->conf.enableVJCompression) {
 1015                 NG_FREE_ITEM(item);
 1016                 return (ENXIO);
 1017         }
 1018         return (ng_ppp_comp_xmit(node, item, PROT_VJUNCOMP));
 1019 }
 1020 
 1021 /*
 1022  * Receive data on a hook vjc_vjip.
 1023  */
 1024 static int
 1025 ng_ppp_rcvdata_vjc_vjip(hook_p hook, item_p item)
 1026 {
 1027         const node_p node = NG_HOOK_NODE(hook);
 1028         const priv_p priv = NG_NODE_PRIVATE(node);
 1029 
 1030         if (!priv->conf.enableVJCompression) {
 1031                 NG_FREE_ITEM(item);
 1032                 return (ENXIO);
 1033         }
 1034         return (ng_ppp_comp_xmit(node, item, PROT_IP));
 1035 }
 1036 
 1037 static int
 1038 ng_ppp_hcomp_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
 1039 {
 1040         const priv_p priv = NG_NODE_PRIVATE(node);
 1041 
 1042         if (priv->conf.enableVJDecompression && priv->vjCompHooked) {
 1043                 hook_p outHook = NULL;
 1044 
 1045                 switch (proto) {
 1046                     case PROT_VJCOMP:
 1047                         outHook = priv->hooks[HOOK_INDEX_VJC_COMP];
 1048                         break;
 1049                     case PROT_VJUNCOMP:
 1050                         outHook = priv->hooks[HOOK_INDEX_VJC_UNCOMP];
 1051                         break;
 1052                 }
 1053 
 1054                 if (outHook) {
 1055                         int error;
 1056 
 1057                         /* Send packet out hook. */
 1058                         NG_FWD_ITEM_HOOK(error, item, outHook);
 1059                         return (error);
 1060                 }
 1061         }
 1062 
 1063         return (ng_ppp_proto_recv(node, item, proto, linkNum));
 1064 }
 1065 
 1066 /*
 1067  * Receive data on a hook vjc_ip.
 1068  */
 1069 static int
 1070 ng_ppp_rcvdata_vjc_ip(hook_p hook, item_p item)
 1071 {
 1072         const node_p node = NG_HOOK_NODE(hook);
 1073         const priv_p priv = NG_NODE_PRIVATE(node);
 1074 
 1075         if (!priv->conf.enableVJDecompression) {
 1076                 NG_FREE_ITEM(item);
 1077                 return (ENXIO);
 1078         }
 1079         return (ng_ppp_proto_recv(node, item, PROT_IP, NG_PPP_BUNDLE_LINKNUM));
 1080 }
 1081 
 1082 /*
 1083  * Compression layer
 1084  */
 1085 
 1086 static int
 1087 ng_ppp_comp_xmit(node_p node, item_p item, uint16_t proto)
 1088 {
 1089         const priv_p priv = NG_NODE_PRIVATE(node);
 1090 
 1091         if (priv->conf.enableCompression &&
 1092             proto < 0x4000 &&
 1093             proto != PROT_COMPD &&
 1094             proto != PROT_CRYPTD &&
 1095             priv->hooks[HOOK_INDEX_COMPRESS] != NULL) {
 1096                 struct mbuf *m;
 1097                 int error;
 1098 
 1099                 NGI_GET_M(item, m);
 1100                 if ((m = ng_ppp_addproto(m, proto, 0)) == NULL) {
 1101                         NG_FREE_ITEM(item);
 1102                         return (ENOBUFS);
 1103                 }
 1104                 NGI_M(item) = m;
 1105 
 1106                 /* Send packet out hook. */
 1107                 NG_FWD_ITEM_HOOK(error, item, priv->hooks[HOOK_INDEX_COMPRESS]);
 1108                 return (error);
 1109         }
 1110 
 1111         return (ng_ppp_crypt_xmit(node, item, proto));
 1112 }
 1113 
 1114 /*
 1115  * Receive data on a hook compress.
 1116  */
 1117 static int
 1118 ng_ppp_rcvdata_compress(hook_p hook, item_p item)
 1119 {
 1120         const node_p node = NG_HOOK_NODE(hook);
 1121         const priv_p priv = NG_NODE_PRIVATE(node);
 1122         uint16_t proto;
 1123 
 1124         switch (priv->conf.enableCompression) {
 1125             case NG_PPP_COMPRESS_NONE:
 1126                 NG_FREE_ITEM(item);
 1127                 return (ENXIO);
 1128             case NG_PPP_COMPRESS_FULL:
 1129                 {
 1130                         struct mbuf *m;
 1131 
 1132                         NGI_GET_M(item, m);
 1133                         if ((m = ng_ppp_cutproto(m, &proto)) == NULL) {
 1134                                 NG_FREE_ITEM(item);
 1135                                 return (EIO);
 1136                         }
 1137                         NGI_M(item) = m;
 1138                         if (!PROT_VALID(proto)) {
 1139                                 NG_FREE_ITEM(item);
 1140                                 return (EIO);
 1141                         }
 1142                 }
 1143                 break;
 1144             default:
 1145                 proto = PROT_COMPD;
 1146                 break;
 1147         }
 1148         return (ng_ppp_crypt_xmit(node, item, proto));
 1149 }
 1150 
 1151 static int
 1152 ng_ppp_comp_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
 1153 {
 1154         const priv_p priv = NG_NODE_PRIVATE(node);
 1155 
 1156         if (proto < 0x4000 &&
 1157             ((proto == PROT_COMPD && priv->conf.enableDecompression) ||
 1158             priv->conf.enableDecompression == NG_PPP_DECOMPRESS_FULL) &&
 1159             priv->hooks[HOOK_INDEX_DECOMPRESS] != NULL) {
 1160                 int error;
 1161 
 1162                 if (priv->conf.enableDecompression == NG_PPP_DECOMPRESS_FULL) {
 1163                         struct mbuf *m;
 1164                         NGI_GET_M(item, m);
 1165                         if ((m = ng_ppp_addproto(m, proto, 0)) == NULL) {
 1166                                 NG_FREE_ITEM(item);
 1167                                 return (EIO);
 1168                         }
 1169                         NGI_M(item) = m;
 1170                 }
 1171 
 1172                 /* Send packet out hook. */
 1173                 NG_FWD_ITEM_HOOK(error, item,
 1174                     priv->hooks[HOOK_INDEX_DECOMPRESS]);
 1175                 return (error);
 1176         } else if (proto == PROT_COMPD) {
 1177                 /* Disabled protos MUST be silently discarded, but
 1178                  * unsupported MUST not. Let user-level decide this. */
 1179                 return (ng_ppp_bypass(node, item, proto, linkNum));
 1180         }
 1181 
 1182         return (ng_ppp_hcomp_recv(node, item, proto, linkNum));
 1183 }
 1184 
 1185 /*
 1186  * Receive data on a hook decompress.
 1187  */
 1188 static int
 1189 ng_ppp_rcvdata_decompress(hook_p hook, item_p item)
 1190 {
 1191         const node_p node = NG_HOOK_NODE(hook);
 1192         const priv_p priv = NG_NODE_PRIVATE(node);
 1193         uint16_t proto;
 1194         struct mbuf *m;
 1195 
 1196         if (!priv->conf.enableDecompression) {
 1197                 NG_FREE_ITEM(item);
 1198                 return (ENXIO);
 1199         }
 1200         NGI_GET_M(item, m);
 1201         if ((m = ng_ppp_cutproto(m, &proto)) == NULL) {
 1202                 NG_FREE_ITEM(item);
 1203                 return (EIO);
 1204         }
 1205         NGI_M(item) = m;
 1206         if (!PROT_VALID(proto)) {
 1207                 priv->bundleStats.badProtos++;
 1208                 NG_FREE_ITEM(item);
 1209                 return (EIO);
 1210         }
 1211         return (ng_ppp_hcomp_recv(node, item, proto, NG_PPP_BUNDLE_LINKNUM));
 1212 }
 1213 
 1214 /*
 1215  * Encryption layer
 1216  */
 1217 
 1218 static int
 1219 ng_ppp_crypt_xmit(node_p node, item_p item, uint16_t proto)
 1220 {
 1221         const priv_p priv = NG_NODE_PRIVATE(node);
 1222 
 1223         if (priv->conf.enableEncryption &&
 1224             proto < 0x4000 &&
 1225             proto != PROT_CRYPTD &&
 1226             priv->hooks[HOOK_INDEX_ENCRYPT] != NULL) {
 1227                 struct mbuf *m;
 1228                 int error;
 1229 
 1230                 NGI_GET_M(item, m);
 1231                 if ((m = ng_ppp_addproto(m, proto, 0)) == NULL) {
 1232                         NG_FREE_ITEM(item);
 1233                         return (ENOBUFS);
 1234                 }
 1235                 NGI_M(item) = m;
 1236 
 1237                 /* Send packet out hook. */
 1238                 NG_FWD_ITEM_HOOK(error, item, priv->hooks[HOOK_INDEX_ENCRYPT]);
 1239                 return (error);
 1240         }
 1241 
 1242         return (ng_ppp_mp_xmit(node, item, proto));
 1243 }
 1244 
 1245 /*
 1246  * Receive data on a hook encrypt.
 1247  */
 1248 static int
 1249 ng_ppp_rcvdata_encrypt(hook_p hook, item_p item)
 1250 {
 1251         const node_p node = NG_HOOK_NODE(hook);
 1252         const priv_p priv = NG_NODE_PRIVATE(node);
 1253 
 1254         if (!priv->conf.enableEncryption) {
 1255                 NG_FREE_ITEM(item);
 1256                 return (ENXIO);
 1257         }
 1258         return (ng_ppp_mp_xmit(node, item, PROT_CRYPTD));
 1259 }
 1260 
 1261 static int
 1262 ng_ppp_crypt_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
 1263 {
 1264         const priv_p priv = NG_NODE_PRIVATE(node);
 1265 
 1266         if (proto == PROT_CRYPTD) {
 1267                 if (priv->conf.enableDecryption &&
 1268                     priv->hooks[HOOK_INDEX_DECRYPT] != NULL) {
 1269                         int error;
 1270 
 1271                         /* Send packet out hook. */
 1272                         NG_FWD_ITEM_HOOK(error, item,
 1273                             priv->hooks[HOOK_INDEX_DECRYPT]);
 1274                         return (error);
 1275                 } else {
 1276                         /* Disabled protos MUST be silently discarded, but
 1277                          * unsupported MUST not. Let user-level decide this. */
 1278                         return (ng_ppp_bypass(node, item, proto, linkNum));
 1279                 }
 1280         }
 1281 
 1282         return (ng_ppp_comp_recv(node, item, proto, linkNum));
 1283 }
 1284 
 1285 /*
 1286  * Receive data on a hook decrypt.
 1287  */
 1288 static int
 1289 ng_ppp_rcvdata_decrypt(hook_p hook, item_p item)
 1290 {
 1291         const node_p node = NG_HOOK_NODE(hook);
 1292         const priv_p priv = NG_NODE_PRIVATE(node);
 1293         uint16_t proto;
 1294         struct mbuf *m;
 1295 
 1296         if (!priv->conf.enableDecryption) {
 1297                 NG_FREE_ITEM(item);
 1298                 return (ENXIO);
 1299         }
 1300         NGI_GET_M(item, m);
 1301         if ((m = ng_ppp_cutproto(m, &proto)) == NULL) {
 1302                 NG_FREE_ITEM(item);
 1303                 return (EIO);
 1304         }
 1305         NGI_M(item) = m;
 1306         if (!PROT_VALID(proto)) {
 1307                 priv->bundleStats.badProtos++;
 1308                 NG_FREE_ITEM(item);
 1309                 return (EIO);
 1310         }
 1311         return (ng_ppp_comp_recv(node, item, proto, NG_PPP_BUNDLE_LINKNUM));
 1312 }
 1313 
 1314 /*
 1315  * Link layer
 1316  */
 1317 
 1318 static int
 1319 ng_ppp_link_xmit(node_p node, item_p item, uint16_t proto, uint16_t linkNum, int plen)
 1320 {
 1321         const priv_p priv = NG_NODE_PRIVATE(node);
 1322         struct ng_ppp_link *link;
 1323         int len, error;
 1324         struct mbuf *m;
 1325         uint16_t mru;
 1326 
 1327         /* Check if link correct. */
 1328         if (linkNum >= NG_PPP_MAX_LINKS) {
 1329                 ERROUT(ENETDOWN);
 1330         }
 1331 
 1332         /* Get link pointer (optimization). */
 1333         link = &priv->links[linkNum];
 1334 
 1335         /* Check link status (if real). */
 1336         if (link->hook == NULL) {
 1337                 ERROUT(ENETDOWN);
 1338         }
 1339 
 1340         /* Extract mbuf. */
 1341         NGI_GET_M(item, m);
 1342 
 1343         /* Check peer's MRU for this link. */
 1344         mru = link->conf.mru;
 1345         if (mru != 0 && m->m_pkthdr.len > mru) {
 1346                 NG_FREE_M(m);
 1347                 ERROUT(EMSGSIZE);
 1348         }
 1349 
 1350         /* Prepend protocol number, possibly compressed. */
 1351         if ((m = ng_ppp_addproto(m, proto, link->conf.enableProtoComp)) ==
 1352             NULL) {
 1353                 ERROUT(ENOBUFS);
 1354         }
 1355 
 1356         /* Prepend address and control field (unless compressed). */
 1357         if (proto == PROT_LCP || !link->conf.enableACFComp) {
 1358                 if ((m = ng_ppp_prepend(m, &ng_ppp_acf, 2)) == NULL)
 1359                         ERROUT(ENOBUFS);
 1360         }
 1361 
 1362         /* Deliver frame. */
 1363         len = m->m_pkthdr.len;
 1364         NG_FWD_NEW_DATA(error, item, link->hook, m);
 1365 
 1366         mtx_lock(&priv->xmtx);
 1367 
 1368         /* Update link stats. */
 1369         link->stats.xmitFrames++;
 1370         link->stats.xmitOctets += len;
 1371 
 1372         /* Update bundle stats. */
 1373         if (plen > 0) {
 1374             priv->bundleStats.xmitFrames++;
 1375             priv->bundleStats.xmitOctets += plen;
 1376         }
 1377 
 1378         /* Update 'bytes in queue' counter. */
 1379         if (error == 0) {
 1380                 /* bytesInQueue and lastWrite required only for mp_strategy. */
 1381                 if (priv->conf.enableMultilink && !priv->allLinksEqual &&
 1382                     !priv->conf.enableRoundRobin) {
 1383                         /* If queue was empty, then mark this time. */
 1384                         if (link->bytesInQueue == 0)
 1385                                 getmicrouptime(&link->lastWrite);
 1386                         link->bytesInQueue += len + MP_AVERAGE_LINK_OVERHEAD;
 1387                         /* Limit max queue length to 50 pkts. BW can be defined
 1388                            incorrectly and link may not signal overload. */
 1389                         if (link->bytesInQueue > 50 * 1600)
 1390                                 link->bytesInQueue = 50 * 1600;
 1391                 }
 1392         }
 1393         mtx_unlock(&priv->xmtx);
 1394         return (error);
 1395 
 1396 done:
 1397         NG_FREE_ITEM(item);
 1398         return (error);
 1399 }
 1400 
 1401 /*
 1402  * Receive data on a hook linkX.
 1403  */
 1404 static int
 1405 ng_ppp_rcvdata(hook_p hook, item_p item)
 1406 {
 1407         const node_p node = NG_HOOK_NODE(hook);
 1408         const priv_p priv = NG_NODE_PRIVATE(node);
 1409         const int index = (intptr_t)NG_HOOK_PRIVATE(hook);
 1410         const uint16_t linkNum = (uint16_t)~index;
 1411         struct ng_ppp_link * const link = &priv->links[linkNum];
 1412         uint16_t proto;
 1413         struct mbuf *m;
 1414         int error = 0;
 1415 
 1416         KASSERT(linkNum < NG_PPP_MAX_LINKS,
 1417             ("%s: bogus index 0x%x", __func__, index));
 1418 
 1419         NGI_GET_M(item, m);
 1420 
 1421         mtx_lock(&priv->rmtx);
 1422 
 1423         /* Stats */
 1424         link->stats.recvFrames++;
 1425         link->stats.recvOctets += m->m_pkthdr.len;
 1426 
 1427         /* Strip address and control fields, if present. */
 1428         if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL)
 1429                 ERROUT(ENOBUFS);
 1430         if (mtod(m, uint8_t *)[0] == 0xff &&
 1431             mtod(m, uint8_t *)[1] == 0x03)
 1432                 m_adj(m, 2);
 1433 
 1434         /* Get protocol number */
 1435         if ((m = ng_ppp_cutproto(m, &proto)) == NULL)
 1436                 ERROUT(ENOBUFS);
 1437         NGI_M(item) = m;        /* Put changed m back into item. */
 1438 
 1439         if (!PROT_VALID(proto)) {
 1440                 link->stats.badProtos++;
 1441                 ERROUT(EIO);
 1442         }
 1443 
 1444         /* LCP packets must go directly to bypass. */
 1445         if (proto >= 0xB000) {
 1446                 mtx_unlock(&priv->rmtx);
 1447                 return (ng_ppp_bypass(node, item, proto, linkNum));
 1448         }
 1449         
 1450         /* Other packets are denied on a disabled link. */
 1451         if (!link->conf.enableLink)
 1452                 ERROUT(ENXIO);
 1453 
 1454         /* Proceed to multilink layer. Mutex will be unlocked inside. */
 1455         error = ng_ppp_mp_recv(node, item, proto, linkNum);
 1456         mtx_assert(&priv->rmtx, MA_NOTOWNED);
 1457         return (error);
 1458 
 1459 done:
 1460         mtx_unlock(&priv->rmtx);
 1461         NG_FREE_ITEM(item);
 1462         return (error);
 1463 }
 1464 
 1465 /*
 1466  * Multilink layer
 1467  */
 1468 
 1469 /*
 1470  * Handle an incoming multi-link fragment
 1471  *
 1472  * The fragment reassembly algorithm is somewhat complex. This is mainly
 1473  * because we are required not to reorder the reconstructed packets, yet
 1474  * fragments are only guaranteed to arrive in order on a per-link basis.
 1475  * In other words, when we have a complete packet ready, but the previous
 1476  * packet is still incomplete, we have to decide between delivering the
 1477  * complete packet and throwing away the incomplete one, or waiting to
 1478  * see if the remainder of the incomplete one arrives, at which time we
 1479  * can deliver both packets, in order.
 1480  *
 1481  * This problem is exacerbated by "sequence number slew", which is when
 1482  * the sequence numbers coming in from different links are far apart from
 1483  * each other. In particular, certain unnamed equipment (*cough* Ascend)
 1484  * has been seen to generate sequence number slew of up to 10 on an ISDN
 1485  * 2B-channel MP link. There is nothing invalid about sequence number slew
 1486  * but it makes the reasssembly process have to work harder.
 1487  *
 1488  * However, the peer is required to transmit fragments in order on each
 1489  * link. That means if we define MSEQ as the minimum over all links of
 1490  * the highest sequence number received on that link, then we can always
 1491  * give up any hope of receiving a fragment with sequence number < MSEQ in
 1492  * the future (all of this using 'wraparound' sequence number space).
 1493  * Therefore we can always immediately throw away incomplete packets
 1494  * missing fragments with sequence numbers < MSEQ.
 1495  *
 1496  * Here is an overview of our algorithm:
 1497  *
 1498  *    o Received fragments are inserted into a queue, for which we
 1499  *      maintain these invariants between calls to this function:
 1500  *
 1501  *      - Fragments are ordered in the queue by sequence number
 1502  *      - If a complete packet is at the head of the queue, then
 1503  *        the first fragment in the packet has seq# > MSEQ + 1
 1504  *        (otherwise, we could deliver it immediately)
 1505  *      - If any fragments have seq# < MSEQ, then they are necessarily
 1506  *        part of a packet whose missing seq#'s are all > MSEQ (otherwise,
 1507  *        we can throw them away because they'll never be completed)
 1508  *      - The queue contains at most MP_MAX_QUEUE_LEN fragments
 1509  *
 1510  *    o We have a periodic timer that checks the queue for the first
 1511  *      complete packet that has been sitting in the queue "too long".
 1512  *      When one is detected, all previous (incomplete) fragments are
 1513  *      discarded, their missing fragments are declared lost and MSEQ
 1514  *      is increased.
 1515  *
 1516  *    o If we receive a fragment with seq# < MSEQ, we throw it away
 1517  *      because we've already delcared it lost.
 1518  *
 1519  * This assumes linkNum != NG_PPP_BUNDLE_LINKNUM.
 1520  */
 1521 static int
 1522 ng_ppp_mp_recv(node_p node, item_p item, uint16_t proto, uint16_t linkNum)
 1523 {
 1524         const priv_p priv = NG_NODE_PRIVATE(node);
 1525         struct ng_ppp_link *const link = &priv->links[linkNum];
 1526         struct ng_ppp_frag *frag;
 1527         struct ng_ppp_frag *qent;
 1528         int i, diff, inserted;
 1529         struct mbuf *m;
 1530         int     error = 0;
 1531 
 1532         if ((!priv->conf.enableMultilink) || proto != PROT_MP) {
 1533                 /* Stats */
 1534                 priv->bundleStats.recvFrames++;
 1535                 priv->bundleStats.recvOctets += NGI_M(item)->m_pkthdr.len;
 1536 
 1537                 mtx_unlock(&priv->rmtx);
 1538                 return (ng_ppp_crypt_recv(node, item, proto, linkNum));
 1539         }
 1540 
 1541         NGI_GET_M(item, m);
 1542 
 1543         /* Get a new frag struct from the free queue */
 1544         if ((frag = TAILQ_FIRST(&priv->fragsfree)) == NULL) {
 1545                 printf("No free fragments headers in ng_ppp!\n");
 1546                 NG_FREE_M(m);
 1547                 goto process;
 1548         }
 1549 
 1550         /* Extract fragment information from MP header */
 1551         if (priv->conf.recvShortSeq) {
 1552                 uint16_t shdr;
 1553 
 1554                 if (m->m_pkthdr.len < 2) {
 1555                         link->stats.runts++;
 1556                         NG_FREE_M(m);
 1557                         ERROUT(EINVAL);
 1558                 }
 1559                 if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL)
 1560                         ERROUT(ENOBUFS);
 1561 
 1562                 shdr = be16dec(mtod(m, void *));
 1563                 frag->seq = MP_SHORT_EXTEND(shdr);
 1564                 frag->first = (shdr & MP_SHORT_FIRST_FLAG) != 0;
 1565                 frag->last = (shdr & MP_SHORT_LAST_FLAG) != 0;
 1566                 diff = MP_SHORT_SEQ_DIFF(frag->seq, priv->mseq);
 1567                 m_adj(m, 2);
 1568         } else {
 1569                 uint32_t lhdr;
 1570 
 1571                 if (m->m_pkthdr.len < 4) {
 1572                         link->stats.runts++;
 1573                         NG_FREE_M(m);
 1574                         ERROUT(EINVAL);
 1575                 }
 1576                 if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL)
 1577                         ERROUT(ENOBUFS);
 1578 
 1579                 lhdr = be32dec(mtod(m, void *));
 1580                 frag->seq = MP_LONG_EXTEND(lhdr);
 1581                 frag->first = (lhdr & MP_LONG_FIRST_FLAG) != 0;
 1582                 frag->last = (lhdr & MP_LONG_LAST_FLAG) != 0;
 1583                 diff = MP_LONG_SEQ_DIFF(frag->seq, priv->mseq);
 1584                 m_adj(m, 4);
 1585         }
 1586         frag->data = m;
 1587         getmicrouptime(&frag->timestamp);
 1588 
 1589         /* If sequence number is < MSEQ, we've already declared this
 1590            fragment as lost, so we have no choice now but to drop it */
 1591         if (diff < 0) {
 1592                 link->stats.dropFragments++;
 1593                 NG_FREE_M(m);
 1594                 ERROUT(0);
 1595         }
 1596 
 1597         /* Update highest received sequence number on this link and MSEQ */
 1598         priv->mseq = link->seq = frag->seq;
 1599         for (i = 0; i < priv->numActiveLinks; i++) {
 1600                 struct ng_ppp_link *const alink =
 1601                     &priv->links[priv->activeLinks[i]];
 1602 
 1603                 if (MP_RECV_SEQ_DIFF(priv, alink->seq, priv->mseq) < 0)
 1604                         priv->mseq = alink->seq;
 1605         }
 1606 
 1607         /* Remove frag struct from free queue. */
 1608         TAILQ_REMOVE(&priv->fragsfree, frag, f_qent);
 1609 
 1610         /* Add fragment to queue, which is sorted by sequence number */
 1611         inserted = 0;
 1612         TAILQ_FOREACH_REVERSE(qent, &priv->frags, ng_ppp_fraglist, f_qent) {
 1613                 diff = MP_RECV_SEQ_DIFF(priv, frag->seq, qent->seq);
 1614                 if (diff > 0) {
 1615                         TAILQ_INSERT_AFTER(&priv->frags, qent, frag, f_qent);
 1616                         inserted = 1;
 1617                         break;
 1618                 } else if (diff == 0) {         /* should never happen! */
 1619                         link->stats.dupFragments++;
 1620                         NG_FREE_M(frag->data);
 1621                         TAILQ_INSERT_HEAD(&priv->fragsfree, frag, f_qent);
 1622                         ERROUT(EINVAL);
 1623                 }
 1624         }
 1625         if (!inserted)
 1626                 TAILQ_INSERT_HEAD(&priv->frags, frag, f_qent);
 1627 
 1628 process:
 1629         /* Process the queue */
 1630         /* NOTE: rmtx will be unlocked for sending time! */
 1631         error = ng_ppp_frag_process(node, item);
 1632         mtx_unlock(&priv->rmtx);
 1633         return (error);
 1634 
 1635 done:
 1636         mtx_unlock(&priv->rmtx);
 1637         NG_FREE_ITEM(item);
 1638         return (error);
 1639 }
 1640 
 1641 /************************************************************************
 1642                         HELPER STUFF
 1643  ************************************************************************/
 1644 
 1645 /*
 1646  * If new mseq > current then set it and update all active links
 1647  */
 1648 static void
 1649 ng_ppp_bump_mseq(node_p node, int32_t new_mseq)
 1650 {
 1651         const priv_p priv = NG_NODE_PRIVATE(node);
 1652         int i;
 1653         
 1654         if (MP_RECV_SEQ_DIFF(priv, priv->mseq, new_mseq) < 0) {
 1655                 priv->mseq = new_mseq;
 1656                 for (i = 0; i < priv->numActiveLinks; i++) {
 1657                         struct ng_ppp_link *const alink =
 1658                             &priv->links[priv->activeLinks[i]];
 1659 
 1660                         if (MP_RECV_SEQ_DIFF(priv,
 1661                             alink->seq, new_mseq) < 0)
 1662                                 alink->seq = new_mseq;
 1663                 }
 1664         }
 1665 }
 1666 
 1667 /*
 1668  * Examine our list of fragments, and determine if there is a
 1669  * complete and deliverable packet at the head of the list.
 1670  * Return 1 if so, zero otherwise.
 1671  */
 1672 static int
 1673 ng_ppp_check_packet(node_p node)
 1674 {
 1675         const priv_p priv = NG_NODE_PRIVATE(node);
 1676         struct ng_ppp_frag *qent, *qnext;
 1677 
 1678         /* Check for empty queue */
 1679         if (TAILQ_EMPTY(&priv->frags))
 1680                 return (0);
 1681 
 1682         /* Check first fragment is the start of a deliverable packet */
 1683         qent = TAILQ_FIRST(&priv->frags);
 1684         if (!qent->first || MP_RECV_SEQ_DIFF(priv, qent->seq, priv->mseq) > 1)
 1685                 return (0);
 1686 
 1687         /* Check that all the fragments are there */
 1688         while (!qent->last) {
 1689                 qnext = TAILQ_NEXT(qent, f_qent);
 1690                 if (qnext == NULL)      /* end of queue */
 1691                         return (0);
 1692                 if (qnext->seq != MP_NEXT_RECV_SEQ(priv, qent->seq))
 1693                         return (0);
 1694                 qent = qnext;
 1695         }
 1696 
 1697         /* Got one */
 1698         return (1);
 1699 }
 1700 
 1701 /*
 1702  * Pull a completed packet off the head of the incoming fragment queue.
 1703  * This assumes there is a completed packet there to pull off.
 1704  */
 1705 static void
 1706 ng_ppp_get_packet(node_p node, struct mbuf **mp)
 1707 {
 1708         const priv_p priv = NG_NODE_PRIVATE(node);
 1709         struct ng_ppp_frag *qent, *qnext;
 1710         struct mbuf *m = NULL, *tail;
 1711 
 1712         qent = TAILQ_FIRST(&priv->frags);
 1713         KASSERT(!TAILQ_EMPTY(&priv->frags) && qent->first,
 1714             ("%s: no packet", __func__));
 1715         for (tail = NULL; qent != NULL; qent = qnext) {
 1716                 qnext = TAILQ_NEXT(qent, f_qent);
 1717                 KASSERT(!TAILQ_EMPTY(&priv->frags),
 1718                     ("%s: empty q", __func__));
 1719                 TAILQ_REMOVE(&priv->frags, qent, f_qent);
 1720                 if (tail == NULL)
 1721                         tail = m = qent->data;
 1722                 else {
 1723                         m->m_pkthdr.len += qent->data->m_pkthdr.len;
 1724                         tail->m_next = qent->data;
 1725                 }
 1726                 while (tail->m_next != NULL)
 1727                         tail = tail->m_next;
 1728                 if (qent->last) {
 1729                         qnext = NULL;
 1730                         /* Bump MSEQ if necessary */
 1731                         ng_ppp_bump_mseq(node, qent->seq);
 1732                 }
 1733                 TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
 1734         }
 1735         *mp = m;
 1736 }
 1737 
 1738 /*
 1739  * Trim fragments from the queue whose packets can never be completed.
 1740  * This assumes a complete packet is NOT at the beginning of the queue.
 1741  * Returns 1 if fragments were removed, zero otherwise.
 1742  */
 1743 static int
 1744 ng_ppp_frag_trim(node_p node)
 1745 {
 1746         const priv_p priv = NG_NODE_PRIVATE(node);
 1747         struct ng_ppp_frag *qent, *qnext = NULL;
 1748         int removed = 0;
 1749 
 1750         /* Scan for "dead" fragments and remove them */
 1751         while (1) {
 1752                 int dead = 0;
 1753 
 1754                 /* If queue is empty, we're done */
 1755                 if (TAILQ_EMPTY(&priv->frags))
 1756                         break;
 1757 
 1758                 /* Determine whether first fragment can ever be completed */
 1759                 TAILQ_FOREACH(qent, &priv->frags, f_qent) {
 1760                         if (MP_RECV_SEQ_DIFF(priv, qent->seq, priv->mseq) >= 0)
 1761                                 break;
 1762                         qnext = TAILQ_NEXT(qent, f_qent);
 1763                         KASSERT(qnext != NULL,
 1764                             ("%s: last frag < MSEQ?", __func__));
 1765                         if (qnext->seq != MP_NEXT_RECV_SEQ(priv, qent->seq)
 1766                             || qent->last || qnext->first) {
 1767                                 dead = 1;
 1768                                 break;
 1769                         }
 1770                 }
 1771                 if (!dead)
 1772                         break;
 1773 
 1774                 /* Remove fragment and all others in the same packet */
 1775                 while ((qent = TAILQ_FIRST(&priv->frags)) != qnext) {
 1776                         KASSERT(!TAILQ_EMPTY(&priv->frags),
 1777                             ("%s: empty q", __func__));
 1778                         priv->bundleStats.dropFragments++;
 1779                         TAILQ_REMOVE(&priv->frags, qent, f_qent);
 1780                         NG_FREE_M(qent->data);
 1781                         TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
 1782                         removed = 1;
 1783                 }
 1784         }
 1785         return (removed);
 1786 }
 1787 
 1788 /*
 1789  * Drop fragments on queue overflow.
 1790  * Returns 1 if fragments were removed, zero otherwise.
 1791  */
 1792 static int
 1793 ng_ppp_frag_drop(node_p node)
 1794 {
 1795         const priv_p priv = NG_NODE_PRIVATE(node);
 1796 
 1797         /* Check queue length */
 1798         if (TAILQ_EMPTY(&priv->fragsfree)) {
 1799                 struct ng_ppp_frag *qent;
 1800 
 1801                 /* Get oldest fragment */
 1802                 KASSERT(!TAILQ_EMPTY(&priv->frags),
 1803                     ("%s: empty q", __func__));
 1804                 qent = TAILQ_FIRST(&priv->frags);
 1805 
 1806                 /* Bump MSEQ if necessary */
 1807                 ng_ppp_bump_mseq(node, qent->seq);
 1808 
 1809                 /* Drop it */
 1810                 priv->bundleStats.dropFragments++;
 1811                 TAILQ_REMOVE(&priv->frags, qent, f_qent);
 1812                 NG_FREE_M(qent->data);
 1813                 TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
 1814 
 1815                 return (1);
 1816         }
 1817         return (0);
 1818 }
 1819 
 1820 /*
 1821  * Run the queue, restoring the queue invariants
 1822  */
 1823 static int
 1824 ng_ppp_frag_process(node_p node, item_p oitem)
 1825 {
 1826         const priv_p priv = NG_NODE_PRIVATE(node);
 1827         struct mbuf *m;
 1828         item_p item;
 1829         uint16_t proto;
 1830 
 1831         do {
 1832                 /* Deliver any deliverable packets */
 1833                 while (ng_ppp_check_packet(node)) {
 1834                         ng_ppp_get_packet(node, &m);
 1835                         if ((m = ng_ppp_cutproto(m, &proto)) == NULL)
 1836                                 continue;
 1837                         if (!PROT_VALID(proto)) {
 1838                                 priv->bundleStats.badProtos++;
 1839                                 NG_FREE_M(m);
 1840                                 continue;
 1841                         }
 1842                         if (oitem) { /* If original item present - reuse it. */
 1843                                 item = oitem;
 1844                                 oitem = NULL;
 1845                                 NGI_M(item) = m;
 1846                         } else {
 1847                                 item = ng_package_data(m, NG_NOFLAGS);
 1848                         }
 1849                         if (item != NULL) {
 1850                                 /* Stats */
 1851                                 priv->bundleStats.recvFrames++;
 1852                                 priv->bundleStats.recvOctets +=
 1853                                     NGI_M(item)->m_pkthdr.len;
 1854 
 1855                                 /* Drop mutex for the sending time.
 1856                                  * Priv may change, but we are ready!
 1857                                  */
 1858                                 mtx_unlock(&priv->rmtx);
 1859                                 ng_ppp_crypt_recv(node, item, proto,
 1860                                         NG_PPP_BUNDLE_LINKNUM);
 1861                                 mtx_lock(&priv->rmtx);
 1862                         }
 1863                 }
 1864           /* Delete dead fragments and try again */
 1865         } while (ng_ppp_frag_trim(node) || ng_ppp_frag_drop(node));
 1866         
 1867         /* If we haven't reused original item - free it. */
 1868         if (oitem) NG_FREE_ITEM(oitem);
 1869 
 1870         /* Done */
 1871         return (0);
 1872 }
 1873 
 1874 /*
 1875  * Check for 'stale' completed packets that need to be delivered
 1876  *
 1877  * If a link goes down or has a temporary failure, MSEQ can get
 1878  * "stuck", because no new incoming fragments appear on that link.
 1879  * This can cause completed packets to never get delivered if
 1880  * their sequence numbers are all > MSEQ + 1.
 1881  *
 1882  * This routine checks how long all of the completed packets have
 1883  * been sitting in the queue, and if too long, removes fragments
 1884  * from the queue and increments MSEQ to allow them to be delivered.
 1885  */
 1886 static void
 1887 ng_ppp_frag_checkstale(node_p node)
 1888 {
 1889         const priv_p priv = NG_NODE_PRIVATE(node);
 1890         struct ng_ppp_frag *qent, *beg, *end;
 1891         struct timeval now, age;
 1892         struct mbuf *m;
 1893         int seq;
 1894         item_p item;
 1895         int endseq;
 1896         uint16_t proto;
 1897 
 1898         now.tv_sec = 0;                 /* uninitialized state */
 1899         while (1) {
 1900 
 1901                 /* If queue is empty, we're done */
 1902                 if (TAILQ_EMPTY(&priv->frags))
 1903                         break;
 1904 
 1905                 /* Find the first complete packet in the queue */
 1906                 beg = end = NULL;
 1907                 seq = TAILQ_FIRST(&priv->frags)->seq;
 1908                 TAILQ_FOREACH(qent, &priv->frags, f_qent) {
 1909                         if (qent->first)
 1910                                 beg = qent;
 1911                         else if (qent->seq != seq)
 1912                                 beg = NULL;
 1913                         if (beg != NULL && qent->last) {
 1914                                 end = qent;
 1915                                 break;
 1916                         }
 1917                         seq = MP_NEXT_RECV_SEQ(priv, seq);
 1918                 }
 1919 
 1920                 /* If none found, exit */
 1921                 if (end == NULL)
 1922                         break;
 1923 
 1924                 /* Get current time (we assume we've been up for >= 1 second) */
 1925                 if (now.tv_sec == 0)
 1926                         getmicrouptime(&now);
 1927 
 1928                 /* Check if packet has been queued too long */
 1929                 age = now;
 1930                 timevalsub(&age, &beg->timestamp);
 1931                 if (timevalcmp(&age, &ng_ppp_max_staleness, < ))
 1932                         break;
 1933 
 1934                 /* Throw away junk fragments in front of the completed packet */
 1935                 while ((qent = TAILQ_FIRST(&priv->frags)) != beg) {
 1936                         KASSERT(!TAILQ_EMPTY(&priv->frags),
 1937                             ("%s: empty q", __func__));
 1938                         priv->bundleStats.dropFragments++;
 1939                         TAILQ_REMOVE(&priv->frags, qent, f_qent);
 1940                         NG_FREE_M(qent->data);
 1941                         TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
 1942                 }
 1943 
 1944                 /* Extract completed packet */
 1945                 endseq = end->seq;
 1946                 ng_ppp_get_packet(node, &m);
 1947 
 1948                 if ((m = ng_ppp_cutproto(m, &proto)) == NULL)
 1949                         continue;
 1950                 if (!PROT_VALID(proto)) {
 1951                         priv->bundleStats.badProtos++;
 1952                         NG_FREE_M(m);
 1953                         continue;
 1954                 }
 1955 
 1956                 /* Deliver packet */
 1957                 if ((item = ng_package_data(m, NG_NOFLAGS)) != NULL) {
 1958                         /* Stats */
 1959                         priv->bundleStats.recvFrames++;
 1960                         priv->bundleStats.recvOctets += NGI_M(item)->m_pkthdr.len;
 1961 
 1962                         ng_ppp_crypt_recv(node, item, proto,
 1963                                 NG_PPP_BUNDLE_LINKNUM);
 1964                 }
 1965         }
 1966 }
 1967 
 1968 /*
 1969  * Periodically call ng_ppp_frag_checkstale()
 1970  */
 1971 static void
 1972 ng_ppp_frag_timeout(node_p node, hook_p hook, void *arg1, int arg2)
 1973 {
 1974         /* XXX: is this needed? */
 1975         if (NG_NODE_NOT_VALID(node))
 1976                 return;
 1977 
 1978         /* Scan the fragment queue */
 1979         ng_ppp_frag_checkstale(node);
 1980 
 1981         /* Start timer again */
 1982         ng_ppp_start_frag_timer(node);
 1983 }
 1984 
 1985 /*
 1986  * Deliver a frame out on the bundle, i.e., figure out how to fragment
 1987  * the frame across the individual PPP links and do so.
 1988  */
 1989 static int
 1990 ng_ppp_mp_xmit(node_p node, item_p item, uint16_t proto)
 1991 {
 1992         const priv_p priv = NG_NODE_PRIVATE(node);
 1993         const int hdr_len = priv->conf.xmitShortSeq ? 2 : 4;
 1994         int distrib[NG_PPP_MAX_LINKS];
 1995         int firstFragment;
 1996         int activeLinkNum;
 1997         struct mbuf *m;
 1998         int     plen;
 1999         int     frags;
 2000         int32_t seq;
 2001 
 2002         /* At least one link must be active */
 2003         if (priv->numActiveLinks == 0) {
 2004                 NG_FREE_ITEM(item);
 2005                 return (ENETDOWN);
 2006         }
 2007         
 2008         /* Save length for later stats. */
 2009         plen = NGI_M(item)->m_pkthdr.len;
 2010 
 2011         if (!priv->conf.enableMultilink) {
 2012                 return (ng_ppp_link_xmit(node, item, proto,
 2013                     priv->activeLinks[0], plen));
 2014         }
 2015 
 2016         /* Check peer's MRRU for this bundle. */
 2017         if (plen > priv->conf.mrru) {
 2018                 NG_FREE_ITEM(item);
 2019                 return (EMSGSIZE);
 2020         }
 2021 
 2022         /* Extract mbuf. */
 2023         NGI_GET_M(item, m);
 2024 
 2025         /* Prepend protocol number, possibly compressed. */
 2026         if ((m = ng_ppp_addproto(m, proto, 1)) == NULL) {
 2027                 NG_FREE_ITEM(item);
 2028                 return (ENOBUFS);
 2029         }
 2030 
 2031         /* Clear distribution plan */
 2032         bzero(&distrib, priv->numActiveLinks * sizeof(distrib[0]));
 2033 
 2034         mtx_lock(&priv->xmtx);
 2035 
 2036         /* Round-robin strategy */
 2037         if (priv->conf.enableRoundRobin) {
 2038                 activeLinkNum = priv->lastLink++ % priv->numActiveLinks;
 2039                 distrib[activeLinkNum] = m->m_pkthdr.len;
 2040                 goto deliver;
 2041         }
 2042 
 2043         /* Strategy when all links are equivalent (optimize the common case) */
 2044         if (priv->allLinksEqual) {
 2045                 int     numFrags, fraction, remain;
 2046                 int     i;
 2047                 
 2048                 /* Calculate optimal fragment count */
 2049                 numFrags = priv->numActiveLinks;
 2050                 if (numFrags > m->m_pkthdr.len / MP_MIN_FRAG_LEN)
 2051                     numFrags = m->m_pkthdr.len / MP_MIN_FRAG_LEN;
 2052                 if (numFrags == 0)
 2053                     numFrags = 1;
 2054 
 2055                 fraction = m->m_pkthdr.len / numFrags;
 2056                 remain = m->m_pkthdr.len - (fraction * numFrags);
 2057                 
 2058                 /* Assign distribution */
 2059                 for (i = 0; i < numFrags; i++) {
 2060                         distrib[priv->lastLink++ % priv->numActiveLinks]
 2061                             = fraction + (((remain--) > 0)?1:0);
 2062                 }
 2063                 goto deliver;
 2064         }
 2065 
 2066         /* Strategy when all links are not equivalent */
 2067         ng_ppp_mp_strategy(node, m->m_pkthdr.len, distrib);
 2068 
 2069 deliver:
 2070         /* Estimate fragments count */
 2071         frags = 0;
 2072         for (activeLinkNum = priv->numActiveLinks - 1;
 2073             activeLinkNum >= 0; activeLinkNum--) {
 2074                 const uint16_t linkNum = priv->activeLinks[activeLinkNum];
 2075                 struct ng_ppp_link *const link = &priv->links[linkNum];
 2076                 
 2077                 frags += (distrib[activeLinkNum] + link->conf.mru - hdr_len - 1) /
 2078                     (link->conf.mru - hdr_len);
 2079         }
 2080         
 2081         /* Get out initial sequence number */
 2082         seq = priv->xseq;
 2083 
 2084         /* Update next sequence number */
 2085         if (priv->conf.xmitShortSeq) {
 2086             priv->xseq = (seq + frags) & MP_SHORT_SEQ_MASK;
 2087         } else {
 2088             priv->xseq = (seq + frags) & MP_LONG_SEQ_MASK;
 2089         }
 2090 
 2091         mtx_unlock(&priv->xmtx);
 2092 
 2093         /* Send alloted portions of frame out on the link(s) */
 2094         for (firstFragment = 1, activeLinkNum = priv->numActiveLinks - 1;
 2095             activeLinkNum >= 0; activeLinkNum--) {
 2096                 const uint16_t linkNum = priv->activeLinks[activeLinkNum];
 2097                 struct ng_ppp_link *const link = &priv->links[linkNum];
 2098 
 2099                 /* Deliver fragment(s) out the next link */
 2100                 for ( ; distrib[activeLinkNum] > 0; firstFragment = 0) {
 2101                         int len, lastFragment, error;
 2102                         struct mbuf *m2;
 2103 
 2104                         /* Calculate fragment length; don't exceed link MTU */
 2105                         len = distrib[activeLinkNum];
 2106                         if (len > link->conf.mru - hdr_len)
 2107                                 len = link->conf.mru - hdr_len;
 2108                         distrib[activeLinkNum] -= len;
 2109                         lastFragment = (len == m->m_pkthdr.len);
 2110 
 2111                         /* Split off next fragment as "m2" */
 2112                         m2 = m;
 2113                         if (!lastFragment) {
 2114                                 struct mbuf *n = m_split(m, len, M_NOWAIT);
 2115 
 2116                                 if (n == NULL) {
 2117                                         NG_FREE_M(m);
 2118                                         if (firstFragment)
 2119                                                 NG_FREE_ITEM(item);
 2120                                         return (ENOMEM);
 2121                                 }
 2122                                 m_tag_copy_chain(n, m, M_NOWAIT);
 2123                                 m = n;
 2124                         }
 2125 
 2126                         /* Prepend MP header */
 2127                         if (priv->conf.xmitShortSeq) {
 2128                                 uint16_t shdr;
 2129 
 2130                                 shdr = seq;
 2131                                 seq = (seq + 1) & MP_SHORT_SEQ_MASK;
 2132                                 if (firstFragment)
 2133                                         shdr |= MP_SHORT_FIRST_FLAG;
 2134                                 if (lastFragment)
 2135                                         shdr |= MP_SHORT_LAST_FLAG;
 2136                                 shdr = htons(shdr);
 2137                                 m2 = ng_ppp_prepend(m2, &shdr, 2);
 2138                         } else {
 2139                                 uint32_t lhdr;
 2140 
 2141                                 lhdr = seq;
 2142                                 seq = (seq + 1) & MP_LONG_SEQ_MASK;
 2143                                 if (firstFragment)
 2144                                         lhdr |= MP_LONG_FIRST_FLAG;
 2145                                 if (lastFragment)
 2146                                         lhdr |= MP_LONG_LAST_FLAG;
 2147                                 lhdr = htonl(lhdr);
 2148                                 m2 = ng_ppp_prepend(m2, &lhdr, 4);
 2149                         }
 2150                         if (m2 == NULL) {
 2151                                 if (!lastFragment)
 2152                                         m_freem(m);
 2153                                 if (firstFragment)
 2154                                         NG_FREE_ITEM(item);
 2155                                 return (ENOBUFS);
 2156                         }
 2157 
 2158                         /* Send fragment */
 2159                         if (firstFragment) {
 2160                                 NGI_M(item) = m2; /* Reuse original item. */
 2161                         } else {
 2162                                 item = ng_package_data(m2, NG_NOFLAGS);
 2163                         }
 2164                         if (item != NULL) {
 2165                                 error = ng_ppp_link_xmit(node, item, PROT_MP,
 2166                                             linkNum, (firstFragment?plen:0));
 2167                                 if (error != 0) {
 2168                                         if (!lastFragment)
 2169                                                 NG_FREE_M(m);
 2170                                         return (error);
 2171                                 }
 2172                         }
 2173                 }
 2174         }
 2175 
 2176         /* Done */
 2177         return (0);
 2178 }
 2179 
 2180 /*
 2181  * Computing the optimal fragmentation
 2182  * -----------------------------------
 2183  *
 2184  * This routine tries to compute the optimal fragmentation pattern based
 2185  * on each link's latency, bandwidth, and calculated additional latency.
 2186  * The latter quantity is the additional latency caused by previously
 2187  * written data that has not been transmitted yet.
 2188  *
 2189  * This algorithm is only useful when not all of the links have the
 2190  * same latency and bandwidth values.
 2191  *
 2192  * The essential idea is to make the last bit of each fragment of the
 2193  * frame arrive at the opposite end at the exact same time. This greedy
 2194  * algorithm is optimal, in that no other scheduling could result in any
 2195  * packet arriving any sooner unless packets are delivered out of order.
 2196  *
 2197  * Suppose link i has bandwidth b_i (in tens of bytes per milisecond) and
 2198  * latency l_i (in miliseconds). Consider the function function f_i(t)
 2199  * which is equal to the number of bytes that will have arrived at
 2200  * the peer after t miliseconds if we start writing continuously at
 2201  * time t = 0. Then f_i(t) = b_i * (t - l_i) = ((b_i * t) - (l_i * b_i).
 2202  * That is, f_i(t) is a line with slope b_i and y-intersect -(l_i * b_i).
 2203  * Note that the y-intersect is always <= zero because latency can't be
 2204  * negative.  Note also that really the function is f_i(t) except when
 2205  * f_i(t) is negative, in which case the function is zero.  To take
 2206  * care of this, let Q_i(t) = { if (f_i(t) > 0) return 1; else return 0; }.
 2207  * So the actual number of bytes that will have arrived at the peer after
 2208  * t miliseconds is f_i(t) * Q_i(t).
 2209  *
 2210  * At any given time, each link has some additional latency a_i >= 0
 2211  * due to previously written fragment(s) which are still in the queue.
 2212  * This value is easily computed from the time since last transmission,
 2213  * the previous latency value, the number of bytes written, and the
 2214  * link's bandwidth.
 2215  *
 2216  * Assume that l_i includes any a_i already, and that the links are
 2217  * sorted by latency, so that l_i <= l_{i+1}.
 2218  *
 2219  * Let N be the total number of bytes in the current frame we are sending.
 2220  *
 2221  * Suppose we were to start writing bytes at time t = 0 on all links
 2222  * simultaneously, which is the most we can possibly do.  Then let
 2223  * F(t) be equal to the total number of bytes received by the peer
 2224  * after t miliseconds. Then F(t) = Sum_i (f_i(t) * Q_i(t)).
 2225  *
 2226  * Our goal is simply this: fragment the frame across the links such
 2227  * that the peer is able to reconstruct the completed frame as soon as
 2228  * possible, i.e., at the least possible value of t. Call this value t_0.
 2229  *
 2230  * Then it follows that F(t_0) = N. Our strategy is first to find the value
 2231  * of t_0, and then deduce how many bytes to write to each link.
 2232  *
 2233  * Rewriting F(t_0):
 2234  *
 2235  *   t_0 = ( N + Sum_i ( l_i * b_i * Q_i(t_0) ) ) / Sum_i ( b_i * Q_i(t_0) )
 2236  *
 2237  * Now, we note that Q_i(t) is constant for l_i <= t <= l_{i+1}. t_0 will
 2238  * lie in one of these ranges.  To find it, we just need to find the i such
 2239  * that F(l_i) <= N <= F(l_{i+1}).  Then we compute all the constant values
 2240  * for Q_i() in this range, plug in the remaining values, solving for t_0.
 2241  *
 2242  * Once t_0 is known, then the number of bytes to send on link i is
 2243  * just f_i(t_0) * Q_i(t_0).
 2244  *
 2245  * In other words, we start allocating bytes to the links one at a time.
 2246  * We keep adding links until the frame is completely sent.  Some links
 2247  * may not get any bytes because their latency is too high.
 2248  *
 2249  * Is all this work really worth the trouble?  Depends on the situation.
 2250  * The bigger the ratio of computer speed to link speed, and the more
 2251  * important total bundle latency is (e.g., for interactive response time),
 2252  * the more it's worth it.  There is however the cost of calling this
 2253  * function for every frame.  The running time is O(n^2) where n is the
 2254  * number of links that receive a non-zero number of bytes.
 2255  *
 2256  * Since latency is measured in miliseconds, the "resolution" of this
 2257  * algorithm is one milisecond.
 2258  *
 2259  * To avoid this algorithm altogether, configure all links to have the
 2260  * same latency and bandwidth.
 2261  */
 2262 static void
 2263 ng_ppp_mp_strategy(node_p node, int len, int *distrib)
 2264 {
 2265         const priv_p priv = NG_NODE_PRIVATE(node);
 2266         int latency[NG_PPP_MAX_LINKS];
 2267         int sortByLatency[NG_PPP_MAX_LINKS];
 2268         int activeLinkNum;
 2269         int t0, total, topSum, botSum;
 2270         struct timeval now;
 2271         int i, numFragments;
 2272 
 2273         /* If only one link, this gets real easy */
 2274         if (priv->numActiveLinks == 1) {
 2275                 distrib[0] = len;
 2276                 return;
 2277         }
 2278 
 2279         /* Get current time */
 2280         getmicrouptime(&now);
 2281 
 2282         /* Compute latencies for each link at this point in time */
 2283         for (activeLinkNum = 0;
 2284             activeLinkNum < priv->numActiveLinks; activeLinkNum++) {
 2285                 struct ng_ppp_link *alink;
 2286                 struct timeval diff;
 2287                 int xmitBytes;
 2288 
 2289                 /* Start with base latency value */
 2290                 alink = &priv->links[priv->activeLinks[activeLinkNum]];
 2291                 latency[activeLinkNum] = alink->latency;
 2292                 sortByLatency[activeLinkNum] = activeLinkNum;   /* see below */
 2293 
 2294                 /* Any additional latency? */
 2295                 if (alink->bytesInQueue == 0)
 2296                         continue;
 2297 
 2298                 /* Compute time delta since last write */
 2299                 diff = now;
 2300                 timevalsub(&diff, &alink->lastWrite);
 2301                 
 2302                 /* alink->bytesInQueue will be changed, mark change time. */
 2303                 alink->lastWrite = now;
 2304 
 2305                 if (now.tv_sec < 0 || diff.tv_sec >= 10) {      /* sanity */
 2306                         alink->bytesInQueue = 0;
 2307                         continue;
 2308                 }
 2309 
 2310                 /* How many bytes could have transmitted since last write? */
 2311                 xmitBytes = (alink->conf.bandwidth * 10 * diff.tv_sec)
 2312                     + (alink->conf.bandwidth * (diff.tv_usec / 1000)) / 100;
 2313                 alink->bytesInQueue -= xmitBytes;
 2314                 if (alink->bytesInQueue < 0)
 2315                         alink->bytesInQueue = 0;
 2316                 else
 2317                         latency[activeLinkNum] +=
 2318                             (100 * alink->bytesInQueue) / alink->conf.bandwidth;
 2319         }
 2320 
 2321         /* Sort active links by latency */
 2322         qsort_r(sortByLatency,
 2323             priv->numActiveLinks, sizeof(*sortByLatency), latency, ng_ppp_intcmp);
 2324 
 2325         /* Find the interval we need (add links in sortByLatency[] order) */
 2326         for (numFragments = 1;
 2327             numFragments < priv->numActiveLinks; numFragments++) {
 2328                 for (total = i = 0; i < numFragments; i++) {
 2329                         int flowTime;
 2330 
 2331                         flowTime = latency[sortByLatency[numFragments]]
 2332                             - latency[sortByLatency[i]];
 2333                         total += ((flowTime * priv->links[
 2334                             priv->activeLinks[sortByLatency[i]]].conf.bandwidth)
 2335                                 + 99) / 100;
 2336                 }
 2337                 if (total >= len)
 2338                         break;
 2339         }
 2340 
 2341         /* Solve for t_0 in that interval */
 2342         for (topSum = botSum = i = 0; i < numFragments; i++) {
 2343                 int bw = priv->links[
 2344                     priv->activeLinks[sortByLatency[i]]].conf.bandwidth;
 2345 
 2346                 topSum += latency[sortByLatency[i]] * bw;       /* / 100 */
 2347                 botSum += bw;                                   /* / 100 */
 2348         }
 2349         t0 = ((len * 100) + topSum + botSum / 2) / botSum;
 2350 
 2351         /* Compute f_i(t_0) all i */
 2352         for (total = i = 0; i < numFragments; i++) {
 2353                 int bw = priv->links[
 2354                     priv->activeLinks[sortByLatency[i]]].conf.bandwidth;
 2355 
 2356                 distrib[sortByLatency[i]] =
 2357                     (bw * (t0 - latency[sortByLatency[i]]) + 50) / 100;
 2358                 total += distrib[sortByLatency[i]];
 2359         }
 2360 
 2361         /* Deal with any rounding error */
 2362         if (total < len) {
 2363                 struct ng_ppp_link *fastLink =
 2364                     &priv->links[priv->activeLinks[sortByLatency[0]]];
 2365                 int fast = 0;
 2366 
 2367                 /* Find the fastest link */
 2368                 for (i = 1; i < numFragments; i++) {
 2369                         struct ng_ppp_link *const link =
 2370                             &priv->links[priv->activeLinks[sortByLatency[i]]];
 2371 
 2372                         if (link->conf.bandwidth > fastLink->conf.bandwidth) {
 2373                                 fast = i;
 2374                                 fastLink = link;
 2375                         }
 2376                 }
 2377                 distrib[sortByLatency[fast]] += len - total;
 2378         } else while (total > len) {
 2379                 struct ng_ppp_link *slowLink =
 2380                     &priv->links[priv->activeLinks[sortByLatency[0]]];
 2381                 int delta, slow = 0;
 2382 
 2383                 /* Find the slowest link that still has bytes to remove */
 2384                 for (i = 1; i < numFragments; i++) {
 2385                         struct ng_ppp_link *const link =
 2386                             &priv->links[priv->activeLinks[sortByLatency[i]]];
 2387 
 2388                         if (distrib[sortByLatency[slow]] == 0 ||
 2389                             (distrib[sortByLatency[i]] > 0 &&
 2390                             link->conf.bandwidth < slowLink->conf.bandwidth)) {
 2391                                 slow = i;
 2392                                 slowLink = link;
 2393                         }
 2394                 }
 2395                 delta = total - len;
 2396                 if (delta > distrib[sortByLatency[slow]])
 2397                         delta = distrib[sortByLatency[slow]];
 2398                 distrib[sortByLatency[slow]] -= delta;
 2399                 total -= delta;
 2400         }
 2401 }
 2402 
 2403 /*
 2404  * Compare two integers
 2405  */
 2406 static int
 2407 ng_ppp_intcmp(void *latency, const void *v1, const void *v2)
 2408 {
 2409         const int index1 = *((const int *) v1);
 2410         const int index2 = *((const int *) v2);
 2411 
 2412         return ((int *)latency)[index1] - ((int *)latency)[index2];
 2413 }
 2414 
 2415 /*
 2416  * Prepend a possibly compressed PPP protocol number in front of a frame
 2417  */
 2418 static struct mbuf *
 2419 ng_ppp_addproto(struct mbuf *m, uint16_t proto, int compOK)
 2420 {
 2421         if (compOK && PROT_COMPRESSABLE(proto)) {
 2422                 uint8_t pbyte = (uint8_t)proto;
 2423 
 2424                 return ng_ppp_prepend(m, &pbyte, 1);
 2425         } else {
 2426                 uint16_t pword = htons((uint16_t)proto);
 2427 
 2428                 return ng_ppp_prepend(m, &pword, 2);
 2429         }
 2430 }
 2431 
 2432 /*
 2433  * Cut a possibly compressed PPP protocol number from the front of a frame.
 2434  */
 2435 static struct mbuf *
 2436 ng_ppp_cutproto(struct mbuf *m, uint16_t *proto)
 2437 {
 2438 
 2439         *proto = 0;
 2440         if (m->m_len < 1 && (m = m_pullup(m, 1)) == NULL)
 2441                 return (NULL);
 2442 
 2443         *proto = *mtod(m, uint8_t *);
 2444         m_adj(m, 1);
 2445 
 2446         if (!PROT_VALID(*proto)) {
 2447                 if (m->m_len < 1 && (m = m_pullup(m, 1)) == NULL)
 2448                         return (NULL);
 2449 
 2450                 *proto = (*proto << 8) + *mtod(m, uint8_t *);
 2451                 m_adj(m, 1);
 2452         }
 2453 
 2454         return (m);
 2455 }
 2456 
 2457 /*
 2458  * Prepend some bytes to an mbuf.
 2459  */
 2460 static struct mbuf *
 2461 ng_ppp_prepend(struct mbuf *m, const void *buf, int len)
 2462 {
 2463         M_PREPEND(m, len, M_NOWAIT);
 2464         if (m == NULL || (m->m_len < len && (m = m_pullup(m, len)) == NULL))
 2465                 return (NULL);
 2466         bcopy(buf, mtod(m, uint8_t *), len);
 2467         return (m);
 2468 }
 2469 
 2470 /*
 2471  * Update private information that is derived from other private information
 2472  */
 2473 static void
 2474 ng_ppp_update(node_p node, int newConf)
 2475 {
 2476         const priv_p priv = NG_NODE_PRIVATE(node);
 2477         int i;
 2478 
 2479         /* Update active status for VJ Compression */
 2480         priv->vjCompHooked = priv->hooks[HOOK_INDEX_VJC_IP] != NULL
 2481             && priv->hooks[HOOK_INDEX_VJC_COMP] != NULL
 2482             && priv->hooks[HOOK_INDEX_VJC_UNCOMP] != NULL
 2483             && priv->hooks[HOOK_INDEX_VJC_VJIP] != NULL;
 2484 
 2485         /* Increase latency for each link an amount equal to one MP header */
 2486         if (newConf) {
 2487                 for (i = 0; i < NG_PPP_MAX_LINKS; i++) {
 2488                         int hdrBytes;
 2489 
 2490                         if (priv->links[i].conf.bandwidth == 0)
 2491                             continue;
 2492 
 2493                         hdrBytes = MP_AVERAGE_LINK_OVERHEAD
 2494                             + (priv->links[i].conf.enableACFComp ? 0 : 2)
 2495                             + (priv->links[i].conf.enableProtoComp ? 1 : 2)
 2496                             + (priv->conf.xmitShortSeq ? 2 : 4);
 2497                         priv->links[i].latency =
 2498                             priv->links[i].conf.latency +
 2499                             (hdrBytes / priv->links[i].conf.bandwidth + 50) / 100;
 2500                 }
 2501         }
 2502 
 2503         /* Update list of active links */
 2504         bzero(&priv->activeLinks, sizeof(priv->activeLinks));
 2505         priv->numActiveLinks = 0;
 2506         priv->allLinksEqual = 1;
 2507         for (i = 0; i < NG_PPP_MAX_LINKS; i++) {
 2508                 struct ng_ppp_link *const link = &priv->links[i];
 2509 
 2510                 /* Is link active? */
 2511                 if (link->conf.enableLink && link->hook != NULL) {
 2512                         struct ng_ppp_link *link0;
 2513 
 2514                         /* Add link to list of active links */
 2515                         priv->activeLinks[priv->numActiveLinks++] = i;
 2516                         link0 = &priv->links[priv->activeLinks[0]];
 2517 
 2518                         /* Determine if all links are still equal */
 2519                         if (link->latency != link0->latency
 2520                           || link->conf.bandwidth != link0->conf.bandwidth)
 2521                                 priv->allLinksEqual = 0;
 2522 
 2523                         /* Initialize rec'd sequence number */
 2524                         if (link->seq == MP_NOSEQ) {
 2525                                 link->seq = (link == link0) ?
 2526                                     MP_INITIAL_SEQ : link0->seq;
 2527                         }
 2528                 } else
 2529                         link->seq = MP_NOSEQ;
 2530         }
 2531 
 2532         /* Update MP state as multi-link is active or not */
 2533         if (priv->conf.enableMultilink && priv->numActiveLinks > 0)
 2534                 ng_ppp_start_frag_timer(node);
 2535         else {
 2536                 ng_ppp_stop_frag_timer(node);
 2537                 ng_ppp_frag_reset(node);
 2538                 priv->xseq = MP_INITIAL_SEQ;
 2539                 priv->mseq = MP_INITIAL_SEQ;
 2540                 for (i = 0; i < NG_PPP_MAX_LINKS; i++) {
 2541                         struct ng_ppp_link *const link = &priv->links[i];
 2542 
 2543                         bzero(&link->lastWrite, sizeof(link->lastWrite));
 2544                         link->bytesInQueue = 0;
 2545                         link->seq = MP_NOSEQ;
 2546                 }
 2547         }
 2548 
 2549         if (priv->hooks[HOOK_INDEX_INET] != NULL) {
 2550                 if (priv->conf.enableIP == 1 &&
 2551                     priv->numActiveLinks == 1 &&
 2552                     priv->conf.enableMultilink == 0 &&
 2553                     priv->conf.enableCompression == 0 &&
 2554                     priv->conf.enableEncryption == 0 &&
 2555                     priv->conf.enableVJCompression == 0)
 2556                         NG_HOOK_SET_RCVDATA(priv->hooks[HOOK_INDEX_INET],
 2557                             ng_ppp_rcvdata_inet_fast);
 2558                 else
 2559                         NG_HOOK_SET_RCVDATA(priv->hooks[HOOK_INDEX_INET],
 2560                             ng_ppp_rcvdata_inet);
 2561         }
 2562 }
 2563 
 2564 /*
 2565  * Determine if a new configuration would represent a valid change
 2566  * from the current configuration and link activity status.
 2567  */
 2568 static int
 2569 ng_ppp_config_valid(node_p node, const struct ng_ppp_node_conf *newConf)
 2570 {
 2571         const priv_p priv = NG_NODE_PRIVATE(node);
 2572         int i, newNumLinksActive;
 2573 
 2574         /* Check per-link config and count how many links would be active */
 2575         for (newNumLinksActive = i = 0; i < NG_PPP_MAX_LINKS; i++) {
 2576                 if (newConf->links[i].enableLink && priv->links[i].hook != NULL)
 2577                         newNumLinksActive++;
 2578                 if (!newConf->links[i].enableLink)
 2579                         continue;
 2580                 if (newConf->links[i].mru < MP_MIN_LINK_MRU)
 2581                         return (0);
 2582                 if (newConf->links[i].bandwidth == 0)
 2583                         return (0);
 2584                 if (newConf->links[i].bandwidth > NG_PPP_MAX_BANDWIDTH)
 2585                         return (0);
 2586                 if (newConf->links[i].latency > NG_PPP_MAX_LATENCY)
 2587                         return (0);
 2588         }
 2589 
 2590         /* Disallow changes to multi-link configuration while MP is active */
 2591         if (priv->numActiveLinks > 0 && newNumLinksActive > 0) {
 2592                 if (!priv->conf.enableMultilink
 2593                                 != !newConf->bund.enableMultilink
 2594                     || !priv->conf.xmitShortSeq != !newConf->bund.xmitShortSeq
 2595                     || !priv->conf.recvShortSeq != !newConf->bund.recvShortSeq)
 2596                         return (0);
 2597         }
 2598 
 2599         /* At most one link can be active unless multi-link is enabled */
 2600         if (!newConf->bund.enableMultilink && newNumLinksActive > 1)
 2601                 return (0);
 2602 
 2603         /* Configuration change would be valid */
 2604         return (1);
 2605 }
 2606 
 2607 /*
 2608  * Free all entries in the fragment queue
 2609  */
 2610 static void
 2611 ng_ppp_frag_reset(node_p node)
 2612 {
 2613         const priv_p priv = NG_NODE_PRIVATE(node);
 2614         struct ng_ppp_frag *qent, *qnext;
 2615 
 2616         for (qent = TAILQ_FIRST(&priv->frags); qent; qent = qnext) {
 2617                 qnext = TAILQ_NEXT(qent, f_qent);
 2618                 NG_FREE_M(qent->data);
 2619                 TAILQ_INSERT_HEAD(&priv->fragsfree, qent, f_qent);
 2620         }
 2621         TAILQ_INIT(&priv->frags);
 2622 }
 2623 
 2624 /*
 2625  * Start fragment queue timer
 2626  */
 2627 static void
 2628 ng_ppp_start_frag_timer(node_p node)
 2629 {
 2630         const priv_p priv = NG_NODE_PRIVATE(node);
 2631 
 2632         if (!(callout_pending(&priv->fragTimer)))
 2633                 ng_callout(&priv->fragTimer, node, NULL, MP_FRAGTIMER_INTERVAL,
 2634                     ng_ppp_frag_timeout, NULL, 0);
 2635 }
 2636 
 2637 /*
 2638  * Stop fragment queue timer
 2639  */
 2640 static void
 2641 ng_ppp_stop_frag_timer(node_p node)
 2642 {
 2643         const priv_p priv = NG_NODE_PRIVATE(node);
 2644 
 2645         if (callout_pending(&priv->fragTimer))
 2646                 ng_uncallout(&priv->fragTimer, node);
 2647 }

Cache object: 2a0de4872b625da013960dd88300ef58


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.