sys/netgraph/pppoe/ng_pppoe.c

   1
   2 /*
   3  * ng_pppoe.c
   4  *
   5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
   6  * All rights reserved.
   7  *
   8  * Subject to the following obligations and disclaimer of warranty, use and
   9  * redistribution of this software, in source or object code forms, with or
  10  * without modifications are expressly permitted by Whistle Communications;
  11  * provided, however, that:
  12  * 1. Any and all reproductions of the source or object code must include the
  13  *    copyright notice above and the following disclaimer of warranties; and
  14  * 2. No rights are granted, in any manner or form, to use Whistle
  15  *    Communications, Inc. trademarks, including the mark "WHISTLE
  16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
  17  *    such appears in the above copyright notice or in the software.
  18  *
  19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
  20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
  21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
  22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
  23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
  24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
  25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
  26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
  27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
  28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
  29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
  31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
  32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
  35  * OF SUCH DAMAGE.
  36  *
  37  * Author: Julian Elischer <julian@freebsd.org>
  38  *
  39  * $FreeBSD: src/sys/netgraph/ng_pppoe.c,v 1.23.2.17 2002/07/02 22:17:18 archie Exp $
  40  * $DragonFly: src/sys/netgraph/pppoe/ng_pppoe.c,v 1.3 2003/08/07 21:17:32 dillon Exp $
  41  * $Whistle: ng_pppoe.c,v 1.10 1999/11/01 09:24:52 julian Exp $
  42  */
  43 #if 0
  44 #define AAA printf("pppoe: %s\n", __FUNCTION__ );
  45 #define BBB printf("-%d-", __LINE__ );
  46 #else
  47 #define AAA
  48 #define BBB
  49 #endif
  50
  51 #include <sys/param.h>
  52 #include <sys/systm.h>
  53 #include <sys/kernel.h>
  54 #include <sys/mbuf.h>
  55 #include <sys/malloc.h>
  56 #include <sys/errno.h>
  57 #include <sys/sysctl.h>
  58 #include <net/ethernet.h>
  59
  60 #include <netgraph/ng_message.h>
  61 #include <netgraph/netgraph.h>
  62 #include "ng_pppoe.h"
  63
  64 #define SIGNOFF "session closed"
  65
  66 /*
  67  * This section contains the netgraph method declarations for the
  68  * pppoe node. These methods define the netgraph pppoe 'type'.
  69  */
  70
  71 static ng_constructor_t ng_pppoe_constructor;
  72 static ng_rcvmsg_t      ng_pppoe_rcvmsg;
  73 static ng_shutdown_t    ng_pppoe_rmnode;
  74 static ng_newhook_t     ng_pppoe_newhook;
  75 static ng_connect_t     ng_pppoe_connect;
  76 static ng_rcvdata_t     ng_pppoe_rcvdata;
  77 static ng_disconnect_t  ng_pppoe_disconnect;
  78
  79 /* Netgraph node type descriptor */
  80 static struct ng_type typestruct = {
  81         NG_VERSION,
  82         NG_PPPOE_NODE_TYPE,
  83         NULL,
  84         ng_pppoe_constructor,
  85         ng_pppoe_rcvmsg,
  86         ng_pppoe_rmnode,
  87         ng_pppoe_newhook,
  88         NULL,
  89         ng_pppoe_connect,
  90         ng_pppoe_rcvdata,
  91         ng_pppoe_rcvdata,
  92         ng_pppoe_disconnect,
  93         NULL
  94 };
  95 NETGRAPH_INIT(pppoe, &typestruct);
  96
  97 /*
  98  * States for the session state machine.
  99  * These have no meaning if there is no hook attached yet.
 100  */
 101 enum state {
 102     PPPOE_SNONE=0,      /* [both] Initial state */
 103     PPPOE_LISTENING,    /* [Daemon] Listening for discover initiation pkt */
 104     PPPOE_SINIT,        /* [Client] Sent discovery initiation */
 105     PPPOE_PRIMED,       /* [Server] Awaiting PADI from daemon */
 106     PPPOE_SOFFER,       /* [Server] Sent offer message  (got PADI)*/
 107     PPPOE_SREQ,         /* [Client] Sent a Request */
 108     PPPOE_NEWCONNECTED, /* [Server] Connection established, No data received */
 109     PPPOE_CONNECTED,    /* [Both] Connection established, Data received */
 110     PPPOE_DEAD          /* [Both] */
 111 };
 112
 113 #define NUMTAGS 20 /* number of tags we are set up to work with */
 114
 115 /*
 116  * Information we store for each hook on each node for negotiating the
 117  * session. The mbuf and cluster are freed once negotiation has completed.
 118  * The whole negotiation block is then discarded.
 119  */
 120
 121 struct sess_neg {
 122         struct mbuf             *m; /* holds cluster with last sent packet */
 123         union   packet          *pkt; /* points within the above cluster */
 124         struct callout_handle   timeout_handle;   /* see timeout(9) */
 125         u_int                   timeout; /* 0,1,2,4,8,16 etc. seconds */
 126         u_int                   numtags;
 127         const struct pppoe_tag  *tags[NUMTAGS];
 128         u_int                   service_len;
 129         u_int                   ac_name_len;
 130
 131         struct datatag          service;
 132         struct datatag          ac_name;
 133 };
 134 typedef struct sess_neg *negp;
 135
 136 /*
 137  * Session information that is needed after connection.
 138  */
 139 struct sess_con {
 140         hook_p                  hook;
 141         u_int16_t               Session_ID;
 142         enum state              state;
 143         char                    creator[NG_NODELEN + 1]; /* who to notify */
 144         struct pppoe_full_hdr   pkt_hdr;        /* used when connected */
 145         negp                    neg;            /* used when negotiating */
 146         /*struct sess_con       *hash_next;*/   /* not yet used */
 147 };
 148 typedef struct sess_con *sessp;
 149
 150 /*
 151  * Information we store for each node
 152  */
 153 struct PPPOE {
 154         node_p          node;           /* back pointer to node */
 155         hook_p          ethernet_hook;
 156         hook_p          debug_hook;
 157         u_int           packets_in;     /* packets in from ethernet */
 158         u_int           packets_out;    /* packets out towards ethernet */
 159         u_int32_t       flags;
 160         /*struct sess_con *buckets[HASH_SIZE];*/        /* not yet used */
 161 };
 162 typedef struct PPPOE *priv_p;
 163
 164 struct ether_header eh_prototype =
 165         {{0xff,0xff,0xff,0xff,0xff,0xff},
 166          {0x00,0x00,0x00,0x00,0x00,0x00},
 167          ETHERTYPE_PPPOE_DISC};
 168
 169 static int nonstandard;
 170 static int
 171 ngpppoe_set_ethertype(SYSCTL_HANDLER_ARGS)
 172 {
 173         int error;
 174         int val;
 175
 176         val = nonstandard;
 177         error = sysctl_handle_int(oidp, &val, sizeof(int), req);
 178         if (error != 0 || req->newptr == NULL)
 179                 return (error);
 180         if (val == 1) {
 181                 nonstandard = 1;
 182                 eh_prototype.ether_type = ETHERTYPE_PPPOE_STUPID_DISC;
 183         } else {
 184                 nonstandard = 0;
 185                 eh_prototype.ether_type = ETHERTYPE_PPPOE_DISC;
 186         }
 187         return (0);
 188 }
 189
 190 SYSCTL_PROC(_net_graph, OID_AUTO, nonstandard_pppoe, CTLTYPE_INT | CTLFLAG_RW,
 191     0, sizeof(int), ngpppoe_set_ethertype, "I", "nonstandard ethertype");
 192
 193 union uniq {
 194         char bytes[sizeof(void *)];
 195         void * pointer;
 196         };
 197
 198 #define LEAVE(x) do { error = x; goto quit; } while(0)
 199 static void     pppoe_start(sessp sp);
 200 static void     sendpacket(sessp sp);
 201 static void     pppoe_ticker(void *arg);
 202 static const    struct pppoe_tag *scan_tags(sessp sp,
 203                         const struct pppoe_hdr* ph);
 204 static  int     pppoe_send_event(sessp sp, enum cmd cmdid);
 205
 206 /*************************************************************************
 207  * Some basic utilities  from the Linux version with author's permission.*
 208  * Author:      Michal Ostrowski <mostrows@styx.uwaterloo.ca>            *
 209  ************************************************************************/
 210
 211 /*
 212  * Generate a new session id
 213  * XXX find out the FreeBSD locking scheme.
 214  */
 215 static u_int16_t
 216 get_new_sid(node_p node)
 217 {
 218         static int pppoe_sid = 10;
 219         sessp sp;
 220         hook_p  hook;
 221         u_int16_t val;
 222         priv_p privp = node->private;
 223
 224 AAA
 225 restart:
 226         val = pppoe_sid++;
 227         /*
 228          * Spec says 0xFFFF is reserved.
 229          * Also don't use 0x0000
 230          */
 231         if (val == 0xffff) {
 232                 pppoe_sid = 20;
 233                 goto restart;
 234         }
 235
 236         /* Check it isn't already in use */
 237         LIST_FOREACH(hook, &node->hooks, hooks) {
 238                 /* don't check special hooks */
 239                 if ((hook->private == &privp->debug_hook)
 240                 ||  (hook->private == &privp->ethernet_hook))
 241                         continue;
 242                 sp = hook->private;
 243                 if (sp->Session_ID == val)
 244                         goto restart;
 245         }
 246
 247         return val;
 248 }
 249
 250
 251 /*
 252  * Return the location where the next tag can be put
 253  */
 254 static __inline const struct pppoe_tag*
 255 next_tag(const struct pppoe_hdr* ph)
 256 {
 257         return (const struct pppoe_tag*)(((const char*)&ph->tag[0])
 258             + ntohs(ph->length));
 259 }
 260
 261 /*
 262  * Look for a tag of a specific type
 263  * Don't trust any length the other end says.
 264  * but assume we already sanity checked ph->length.
 265  */
 266 static const struct pppoe_tag*
 267 get_tag(const struct pppoe_hdr* ph, u_int16_t idx)
 268 {
 269         const char *const end = (const char *)next_tag(ph);
 270         const char *ptn;
 271         const struct pppoe_tag *pt = &ph->tag[0];
 272         /*
 273          * Keep processing tags while a tag header will still fit.
 274          */
 275 AAA
 276         while((const char*)(pt + 1) <= end) {
 277             /*
 278              * If the tag data would go past the end of the packet, abort.
 279              */
 280             ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
 281             if(ptn > end)
 282                 return NULL;
 283
 284             if(pt->tag_type == idx)
 285                 return pt;
 286
 287             pt = (const struct pppoe_tag*)ptn;
 288         }
 289         return NULL;
 290 }
 291
 292 /**************************************************************************
 293  * inlines to initialise or add tags to a session's tag list,
 294  **************************************************************************/
 295 /*
 296  * Initialise the session's tag list
 297  */
 298 static void
 299 init_tags(sessp sp)
 300 {
 301 AAA
 302         if(sp->neg == NULL) {
 303                 printf("pppoe: asked to init NULL neg pointer\n");
 304                 return;
 305         }
 306         sp->neg->numtags = 0;
 307 }
 308
 309 static void
 310 insert_tag(sessp sp, const struct pppoe_tag *tp)
 311 {
 312         int     i;
 313         negp neg;
 314
 315 AAA
 316         if((neg = sp->neg) == NULL) {
 317                 printf("pppoe: asked to use NULL neg pointer\n");
 318                 return;
 319         }
 320         if ((i = neg->numtags++) < NUMTAGS) {
 321                 neg->tags[i] = tp;
 322         } else {
 323                 printf("pppoe: asked to add too many tags to packet\n");
 324                 neg->numtags--;
 325         }
 326 }
 327
 328 /*
 329  * Make up a packet, using the tags filled out for the session.
 330  *
 331  * Assume that the actual pppoe header and ethernet header
 332  * are filled out externally to this routine.
 333  * Also assume that neg->wh points to the correct
 334  * location at the front of the buffer space.
 335  */
 336 static void
 337 make_packet(sessp sp) {
 338         struct pppoe_full_hdr *wh = &sp->neg->pkt->pkt_header;
 339         const struct pppoe_tag **tag;
 340         char *dp;
 341         int count;
 342         int tlen;
 343         u_int16_t length = 0;
 344
 345 AAA
 346         if ((sp->neg == NULL) || (sp->neg->m == NULL)) {
 347                 printf("pppoe: make_packet called from wrong state\n");
 348         }
 349         dp = (char *)wh->ph.tag;
 350         for (count = 0, tag = sp->neg->tags;
 351             ((count < sp->neg->numtags) && (count < NUMTAGS));
 352             tag++, count++) {
 353                 tlen = ntohs((*tag)->tag_len) + sizeof(**tag);
 354                 if ((length + tlen) > (ETHER_MAX_LEN - 4 - sizeof(*wh))) {
 355                         printf("pppoe: tags too long\n");
 356                         sp->neg->numtags = count;
 357                         break;  /* XXX chop off what's too long */
 358                 }
 359                 bcopy(*tag, (char *)dp, tlen);
 360                 length += tlen;
 361                 dp += tlen;
 362         }
 363         wh->ph.length = htons(length);
 364         sp->neg->m->m_len = length + sizeof(*wh);
 365         sp->neg->m->m_pkthdr.len = length + sizeof(*wh);
 366 }
 367
 368 /**************************************************************************
 369  * Routine to match a service offered                                     *
 370  **************************************************************************/
 371 /*
 372  * Find a hook that has a service string that matches that
 373  * we are seeking. for now use a simple string.
 374  * In the future we may need something like regexp().
 375  * for testing allow a null string to match 1st found and a null service
 376  * to match all requests. Also make '*' do the same.
 377  */
 378
 379 #define NG_MATCH_EXACT  1
 380 #define NG_MATCH_ANY    2
 381
 382 static hook_p
 383 pppoe_match_svc(node_p node, const char *svc_name, int svc_len, int match)
 384 {
 385         sessp   sp      = NULL;
 386         negp    neg     = NULL;
 387         priv_p  privp   = node->private;
 388         hook_p  allhook = NULL;
 389         hook_p  hook;
 390
 391 AAA
 392         LIST_FOREACH(hook, &node->hooks, hooks) {
 393
 394                 /* skip any hook that is debug or ethernet */
 395                 if ((hook->private == &privp->debug_hook)
 396                 ||  (hook->private == &privp->ethernet_hook))
 397                         continue;
 398                 sp = hook->private;
 399
 400                 /* Skip any sessions which are not in LISTEN mode. */
 401                 if ( sp->state != PPPOE_LISTENING)
 402                         continue;
 403
 404                 neg = sp->neg;
 405
 406                 /* Special case for a blank or "*" service name (wildcard) */
 407                 if (match == NG_MATCH_ANY && neg->service_len == 1 &&
 408                     neg->service.data[0] == '*') {
 409                         allhook = hook;
 410                         continue;
 411                 }
 412
 413                 /* If the lengths don't match, that aint it. */
 414                 if (neg->service_len != svc_len)
 415                         continue;
 416
 417                 /* An exact match? */
 418                 if (svc_len == 0)
 419                         break;
 420
 421                 if (strncmp(svc_name, neg->service.data, svc_len) == 0)
 422                         break;
 423         }
 424         return (hook ? hook : allhook);
 425 }
 426 /**************************************************************************
 427  * Routine to find a particular session that matches an incoming packet   *
 428  **************************************************************************/
 429 static hook_p
 430 pppoe_findsession(node_p node, const struct pppoe_full_hdr *wh)
 431 {
 432         sessp   sp = NULL;
 433         hook_p hook = NULL;
 434         priv_p  privp = node->private;
 435         u_int16_t       session = ntohs(wh->ph.sid);
 436
 437         /*
 438          * find matching peer/session combination.
 439          */
 440 AAA
 441         LIST_FOREACH(hook, &node->hooks, hooks) {
 442                 /* don't check special hooks */
 443                 if ((hook->private == &privp->debug_hook)
 444                 ||  (hook->private == &privp->ethernet_hook)) {
 445                         continue;
 446                 }
 447                 sp = hook->private;
 448                 if ( ( (sp->state == PPPOE_CONNECTED)
 449                     || (sp->state == PPPOE_NEWCONNECTED) )
 450                 && (sp->Session_ID == session)
 451                 && (bcmp(sp->pkt_hdr.eh.ether_dhost,
 452                     wh->eh.ether_shost,
 453                     ETHER_ADDR_LEN)) == 0) {
 454                         break;
 455                 }
 456         }
 457         return (hook);
 458 }
 459
 460 static hook_p
 461 pppoe_finduniq(node_p node, const struct pppoe_tag *tag)
 462 {
 463         hook_p hook = NULL;
 464         priv_p  privp = node->private;
 465         union uniq              uniq;
 466
 467 AAA
 468         bcopy(tag->tag_data, uniq.bytes, sizeof(void *));
 469         /* cycle through all known hooks */
 470         LIST_FOREACH(hook, &node->hooks, hooks) {
 471                 /* don't check special hooks */
 472                 if ((hook->private == &privp->debug_hook)
 473                 ||  (hook->private == &privp->ethernet_hook))
 474                         continue;
 475                 if (uniq.pointer == hook->private)
 476                         break;
 477         }
 478         return (hook);
 479 }
 480
 481 /**************************************************************************
 482  * start of Netgraph entrypoints                                          *
 483  **************************************************************************/
 484
 485 /*
 486  * Allocate the private data structure and the generic node
 487  * and link them together.
 488  *
 489  * ng_make_node_common() returns with a generic node struct
 490  * with a single reference for us.. we transfer it to the
 491  * private structure.. when we free the private struct we must
 492  * unref the node so it gets freed too.
 493  */
 494 static int
 495 ng_pppoe_constructor(node_p *nodep)
 496 {
 497         priv_p privdata;
 498         int error;
 499
 500 AAA
 501         /* Initialize private descriptor */
 502         MALLOC(privdata, priv_p, sizeof(*privdata), M_NETGRAPH, M_NOWAIT);
 503         if (privdata == NULL)
 504                 return (ENOMEM);
 505         bzero(privdata, sizeof(*privdata));
 506
 507         /* Call the 'generic' (ie, superclass) node constructor */
 508         if ((error = ng_make_node_common(&typestruct, nodep))) {
 509                 FREE(privdata, M_NETGRAPH);
 510                 return (error);
 511         }
 512
 513         /* Link structs together; this counts as our one reference to *nodep */
 514         (*nodep)->private = privdata;
 515         privdata->node = *nodep;
 516         return (0);
 517 }
 518
 519 /*
 520  * Give our ok for a hook to be added...
 521  * point the hook's private info to the hook structure.
 522  *
 523  * The following hook names are special:
 524  *  Ethernet:  the hook that should be connected to a NIC.
 525  *  debug:      copies of data sent out here  (when I write the code).
 526  * All other hook names need only be unique. (the framework checks this).
 527  */
 528 static int
 529 ng_pppoe_newhook(node_p node, hook_p hook, const char *name)
 530 {
 531         const priv_p privp = node->private;
 532         sessp sp;
 533
 534 AAA
 535         if (strcmp(name, NG_PPPOE_HOOK_ETHERNET) == 0) {
 536                 privp->ethernet_hook = hook;
 537                 hook->private = &privp->ethernet_hook;
 538         } else if (strcmp(name, NG_PPPOE_HOOK_DEBUG) == 0) {
 539                 privp->debug_hook = hook;
 540                 hook->private = &privp->debug_hook;
 541         } else {
 542                 /*
 543                  * Any other unique name is OK.
 544                  * The infrastructure has already checked that it's unique,
 545                  * so just allocate it and hook it in.
 546                  */
 547                 MALLOC(sp, sessp, sizeof(*sp), M_NETGRAPH, M_NOWAIT);
 548                 if (sp == NULL) {
 549                                 return (ENOMEM);
 550                 }
 551                 bzero(sp, sizeof(*sp));
 552
 553                 hook->private = sp;
 554                 sp->hook = hook;
 555         }
 556         return(0);
 557 }
 558
 559 /*
 560  * Get a netgraph control message.
 561  * Check it is one we understand. If needed, send a response.
 562  * We sometimes save the address for an async action later.
 563  * Always free the message.
 564  */
 565 static int
 566 ng_pppoe_rcvmsg(node_p node,
 567            struct ng_mesg *msg, const char *retaddr, struct ng_mesg **rptr)
 568 {
 569         priv_p privp = node->private;
 570         struct ngpppoe_init_data *ourmsg = NULL;
 571         struct ng_mesg *resp = NULL;
 572         int error = 0;
 573         hook_p hook = NULL;
 574         sessp sp = NULL;
 575         negp neg = NULL;
 576
 577 AAA
 578         /* Deal with message according to cookie and command */
 579         switch (msg->header.typecookie) {
 580         case NGM_PPPOE_COOKIE:
 581                 switch (msg->header.cmd) {
 582                 case NGM_PPPOE_CONNECT:
 583                 case NGM_PPPOE_LISTEN:
 584                 case NGM_PPPOE_OFFER:
 585                 case NGM_PPPOE_SERVICE:
 586                         ourmsg = (struct ngpppoe_init_data *)msg->data;
 587                         if (( sizeof(*ourmsg) > msg->header.arglen)
 588                         || ((sizeof(*ourmsg) + ourmsg->data_len)
 589                             > msg->header.arglen)) {
 590                                 printf("pppoe_rcvmsg: bad arg size");
 591                                 LEAVE(EMSGSIZE);
 592                         }
 593                         if (ourmsg->data_len > PPPOE_SERVICE_NAME_SIZE) {
 594                                 printf("pppoe: init data too long (%d)\n",
 595                                                         ourmsg->data_len);
 596                                 LEAVE(EMSGSIZE);
 597                         }
 598                         /* make sure strcmp will terminate safely */
 599                         ourmsg->hook[sizeof(ourmsg->hook) - 1] = '\0';
 600
 601                         /* cycle through all known hooks */
 602                         LIST_FOREACH(hook, &node->hooks, hooks) {
 603                                 if (hook->name
 604                                 && strcmp(hook->name, ourmsg->hook) == 0)
 605                                         break;
 606                         }
 607                         if (hook == NULL) {
 608                                 LEAVE(ENOENT);
 609                         }
 610                         if ((hook->private == &privp->debug_hook)
 611                         ||  (hook->private == &privp->ethernet_hook)) {
 612                                 LEAVE(EINVAL);
 613                         }
 614                         sp = hook->private;
 615
 616                         if (msg->header.cmd == NGM_PPPOE_LISTEN) {
 617                                 /*
 618                                  * Ensure we aren't already listening for this
 619                                  * service.
 620                                  */
 621                                 if (pppoe_match_svc(node, ourmsg->data,
 622                                     ourmsg->data_len, NG_MATCH_EXACT) != NULL) {
 623                                         LEAVE(EEXIST);
 624                                 }
 625                         }
 626
 627                         /*
 628                          * PPPOE_SERVICE advertisments are set up
 629                          * on sessions that are in PRIMED state.
 630                          */
 631                         if (msg->header.cmd == NGM_PPPOE_SERVICE) {
 632                                 break;
 633                         }
 634                         if (sp->state |= PPPOE_SNONE) {
 635                                 printf("pppoe: Session already active\n");
 636                                 LEAVE(EISCONN);
 637                         }
 638
 639                         /*
 640                          * set up prototype header
 641                          */
 642                         MALLOC(neg, negp, sizeof(*neg), M_NETGRAPH, M_NOWAIT);
 643
 644                         if (neg == NULL) {
 645                                 printf("pppoe: Session out of memory\n");
 646                                 LEAVE(ENOMEM);
 647                         }
 648                         bzero(neg, sizeof(*neg));
 649                         MGETHDR(neg->m, M_DONTWAIT, MT_DATA);
 650                         if(neg->m == NULL) {
 651                                 printf("pppoe: Session out of mbufs\n");
 652                                 FREE(neg, M_NETGRAPH);
 653                                 LEAVE(ENOBUFS);
 654                         }
 655                         neg->m->m_pkthdr.rcvif = NULL;
 656                         MCLGET(neg->m, M_DONTWAIT);
 657                         if ((neg->m->m_flags & M_EXT) == 0) {
 658                                 printf("pppoe: Session out of mcls\n");
 659                                 m_freem(neg->m);
 660                                 FREE(neg, M_NETGRAPH);
 661                                 LEAVE(ENOBUFS);
 662                         }
 663                         sp->neg = neg;
 664                         callout_handle_init( &neg->timeout_handle);
 665                         neg->m->m_len = sizeof(struct pppoe_full_hdr);
 666                         neg->pkt = mtod(neg->m, union packet*);
 667                         neg->pkt->pkt_header.eh = eh_prototype;
 668                         neg->pkt->pkt_header.ph.ver = 0x1;
 669                         neg->pkt->pkt_header.ph.type = 0x1;
 670                         neg->pkt->pkt_header.ph.sid = 0x0000;
 671                         neg->timeout = 0;
 672
 673                         strncpy(sp->creator, retaddr, NG_NODELEN);
 674                         sp->creator[NG_NODELEN] = '\0';
 675                 }
 676                 switch (msg->header.cmd) {
 677                 case NGM_PPPOE_GET_STATUS:
 678                     {
 679                         struct ngpppoestat *stats;
 680
 681                         NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
 682                         if (!resp) {
 683                                 LEAVE(ENOMEM);
 684                         }
 685                         stats = (struct ngpppoestat *) resp->data;
 686                         stats->packets_in = privp->packets_in;
 687                         stats->packets_out = privp->packets_out;
 688                         break;
 689                     }
 690                 case NGM_PPPOE_CONNECT:
 691                         /*
 692                          * Check the hook exists and is Uninitialised.
 693                          * Send a PADI request, and start the timeout logic.
 694                          * Store the originator of this message so we can send
 695                          * a success of fail message to them later.
 696                          * Move the session to SINIT
 697                          * Set up the session to the correct state and
 698                          * start it.
 699                          */
 700                         neg->service.hdr.tag_type = PTT_SRV_NAME;
 701                         neg->service.hdr.tag_len =
 702                                         htons((u_int16_t)ourmsg->data_len);
 703                         if (ourmsg->data_len) {
 704                                 bcopy(ourmsg->data,
 705                                         neg->service.data, ourmsg->data_len);
 706                         }
 707                         neg->service_len = ourmsg->data_len;
 708                         pppoe_start(sp);
 709                         break;
 710                 case NGM_PPPOE_LISTEN:
 711                         /*
 712                          * Check the hook exists and is Uninitialised.
 713                          * Install the service matching string.
 714                          * Store the originator of this message so we can send
 715                          * a success of fail message to them later.
 716                          * Move the hook to 'LISTENING'
 717                          */
 718                         neg->service.hdr.tag_type = PTT_SRV_NAME;
 719                         neg->service.hdr.tag_len =
 720                                         htons((u_int16_t)ourmsg->data_len);
 721
 722                         if (ourmsg->data_len) {
 723                                 bcopy(ourmsg->data,
 724                                         neg->service.data, ourmsg->data_len);
 725                         }
 726                         neg->service_len = ourmsg->data_len;
 727                         neg->pkt->pkt_header.ph.code = PADT_CODE;
 728                         /*
 729                          * wait for PADI packet coming from ethernet
 730                          */
 731                         sp->state = PPPOE_LISTENING;
 732                         break;
 733                 case NGM_PPPOE_OFFER:
 734                         /*
 735                          * Check the hook exists and is Uninitialised.
 736                          * Store the originator of this message so we can send
 737                          * a success of fail message to them later.
 738                          * Store the AC-Name given and go to PRIMED.
 739                          */
 740                         neg->ac_name.hdr.tag_type = PTT_AC_NAME;
 741                         neg->ac_name.hdr.tag_len =
 742                                         htons((u_int16_t)ourmsg->data_len);
 743                         if (ourmsg->data_len) {
 744                                 bcopy(ourmsg->data,
 745                                         neg->ac_name.data, ourmsg->data_len);
 746                         }
 747                         neg->ac_name_len = ourmsg->data_len;
 748                         neg->pkt->pkt_header.ph.code = PADO_CODE;
 749                         /*
 750                          * Wait for PADI packet coming from hook
 751                          */
 752                         sp->state = PPPOE_PRIMED;
 753                         break;
 754                 case NGM_PPPOE_SERVICE:
 755                         /*
 756                          * Check the session is primed.
 757                          * for now just allow ONE service to be advertised.
 758                          * If you do it twice you just overwrite.
 759                          */
 760                         if (sp->state != PPPOE_PRIMED) {
 761                                 printf("pppoe: Session not primed\n");
 762                                 LEAVE(EISCONN);
 763                         }
 764                         neg = sp->neg;
 765                         neg->service.hdr.tag_type = PTT_SRV_NAME;
 766                         neg->service.hdr.tag_len =
 767                             htons((u_int16_t)ourmsg->data_len);
 768
 769                         if (ourmsg->data_len)
 770                                 bcopy(ourmsg->data, neg->service.data,
 771                                     ourmsg->data_len);
 772                         neg->service_len = ourmsg->data_len;
 773                         break;
 774                 default:
 775                         LEAVE(EINVAL);
 776                 }
 777                 break;
 778         default:
 779                 LEAVE(EINVAL);
 780         }
 781
 782         /* Take care of synchronous response, if any */
 783         if (rptr)
 784                 *rptr = resp;
 785         else if (resp)
 786                 FREE(resp, M_NETGRAPH);
 787
 788         /* Free the message and return */
 789 quit:
 790         FREE(msg, M_NETGRAPH);
 791         return(error);
 792 }
 793
 794 /*
 795  * Start a client into the first state. A separate function because
 796  * it can be needed if the negotiation times out.
 797  */
 798 static void
 799 pppoe_start(sessp sp)
 800 {
 801         struct {
 802                 struct pppoe_tag hdr;
 803                 union   uniq    data;
 804         } __attribute ((packed)) uniqtag;
 805
 806         /*
 807          * kick the state machine into starting up
 808          */
 809 AAA
 810         sp->state = PPPOE_SINIT;
 811         /* reset the packet header to broadcast */
 812         sp->neg->pkt->pkt_header.eh = eh_prototype;
 813         sp->neg->pkt->pkt_header.ph.code = PADI_CODE;
 814         uniqtag.hdr.tag_type = PTT_HOST_UNIQ;
 815         uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(uniqtag.data));
 816         uniqtag.data.pointer = sp;
 817         init_tags(sp);
 818         insert_tag(sp, &uniqtag.hdr);
 819         insert_tag(sp, &sp->neg->service.hdr);
 820         make_packet(sp);
 821         sendpacket(sp);
 822 }
 823
 824 static int
 825 send_acname(sessp sp, const struct pppoe_tag *tag)
 826 {
 827         int error, tlen;
 828         struct ng_mesg *msg;
 829         struct ngpppoe_sts *sts;
 830
 831         NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_ACNAME,
 832             sizeof(struct ngpppoe_sts), M_NOWAIT);
 833         if (msg == NULL)
 834                 return (ENOMEM);
 835
 836         sts = (struct ngpppoe_sts *)msg->data;
 837         tlen = min(NG_HOOKLEN, ntohs(tag->tag_len));
 838         strncpy(sts->hook, tag->tag_data, tlen);
 839         sts->hook[tlen] = '\0';
 840         error = ng_send_msg(sp->hook->node, msg, sp->creator, NULL);
 841
 842         return (error);
 843 }
 844
 845 static int
 846 send_sessionid(sessp sp)
 847 {
 848         int error;
 849         struct ng_mesg *msg;
 850
 851         NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, NGM_PPPOE_SESSIONID,
 852             sizeof(u_int16_t), M_NOWAIT);
 853         if (msg == NULL)
 854                 return (ENOMEM);
 855
 856         *(u_int16_t *)msg->data = sp->Session_ID;
 857         error = ng_send_msg(sp->hook->node, msg, sp->creator, NULL);
 858
 859         return (error);
 860 }
 861
 862 /*
 863  * Receive data, and do something with it.
 864  * The caller will never free m or meta, so
 865  * if we use up this data or abort we must free BOTH of these.
 866  */
 867 static int
 868 ng_pppoe_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
 869 {
 870         node_p                  node = hook->node;
 871         const priv_p            privp = node->private;
 872         sessp                   sp = hook->private;
 873         const struct pppoe_full_hdr *wh;
 874         const struct pppoe_hdr  *ph;
 875         int                     error = 0;
 876         u_int16_t               session;
 877         u_int16_t               length;
 878         u_int8_t                code;
 879         const struct pppoe_tag  *utag = NULL, *tag = NULL;
 880         hook_p                  sendhook;
 881         struct {
 882                 struct pppoe_tag hdr;
 883                 union   uniq    data;
 884         } __attribute ((packed)) uniqtag;
 885         negp                    neg = NULL;
 886
 887 AAA
 888         if (hook->private == &privp->debug_hook) {
 889                 /*
 890                  * Data from the debug hook gets sent without modification
 891                  * straight to the ethernet.
 892                  */
 893                 NG_SEND_DATA( error, privp->ethernet_hook, m, meta);
 894                 privp->packets_out++;
 895         } else if (hook->private == &privp->ethernet_hook) {
 896                 /*
 897                  * Incoming data.
 898                  * Dig out various fields from the packet.
 899                  * use them to decide where to send it.
 900                  */
 901
 902                 privp->packets_in++;
 903                 if( m->m_len < sizeof(*wh)) {
 904                         m = m_pullup(m, sizeof(*wh)); /* Checks length */
 905                         if (m == NULL) {
 906                                 printf("couldn't m_pullup\n");
 907                                 LEAVE(ENOBUFS);
 908                         }
 909                 }
 910                 wh = mtod(m, struct pppoe_full_hdr *);
 911                 ph = &wh->ph;
 912                 session = ntohs(wh->ph.sid);
 913                 length = ntohs(wh->ph.length);
 914                 code = wh->ph.code;
 915                 switch(wh->eh.ether_type) {
 916                 case    ETHERTYPE_PPPOE_STUPID_DISC:
 917                         nonstandard = 1;
 918                         eh_prototype.ether_type = ETHERTYPE_PPPOE_STUPID_DISC;
 919                         /* fall through */
 920                 case    ETHERTYPE_PPPOE_DISC:
 921                         /*
 922                          * We need to try to make sure that the tag area
 923                          * is contiguous, or we could wander off the end
 924                          * of a buffer and make a mess.
 925                          * (Linux wouldn't have this problem).
 926                          */
 927 /*XXX fix this mess */
 928
 929                         if (m->m_pkthdr.len <= MHLEN) {
 930                                 if( m->m_len < m->m_pkthdr.len) {
 931                                         m = m_pullup(m, m->m_pkthdr.len);
 932                                         if (m == NULL) {
 933                                                 printf("couldn't m_pullup\n");
 934                                                 LEAVE(ENOBUFS);
 935                                         }
 936                                 }
 937                         }
 938                         if (m->m_len != m->m_pkthdr.len) {
 939                                 /*
 940                                  * It's not all in one piece.
 941                                  * We need to do extra work.
 942                                  */
 943                                 printf("packet fragmented\n");
 944                                 LEAVE(EMSGSIZE);
 945                         }
 946
 947                         switch(code) {
 948                         case    PADI_CODE:
 949                                 /*
 950                                  * We are a server:
 951                                  * Look for a hook with the required service
 952                                  * and send the ENTIRE packet up there.
 953                                  * It should come back to a new hook in
 954                                  * PRIMED state. Look there for further
 955                                  * processing.
 956                                  */
 957                                 tag = get_tag(ph, PTT_SRV_NAME);
 958                                 if (tag == NULL) {
 959                                         printf("no service tag\n");
 960                                         LEAVE(ENETUNREACH);
 961                                 }
 962                                 sendhook = pppoe_match_svc(hook->node,
 963                                         tag->tag_data, ntohs(tag->tag_len),
 964                                         NG_MATCH_ANY);
 965                                 if (sendhook) {
 966                                         NG_SEND_DATA(error, sendhook, m, meta);
 967                                 } else {
 968                                         LEAVE(ENETUNREACH);
 969                                 }
 970                                 break;
 971                         case    PADO_CODE:
 972                                 /*
 973                                  * We are a client:
 974                                  * Use the host_uniq tag to find the
 975                                  * hook this is in response to.
 976                                  * Received #2, now send #3
 977                                  * For now simply accept the first we receive.
 978                                  */
 979                                 utag = get_tag(ph, PTT_HOST_UNIQ);
 980                                 if ((utag == NULL)
 981                                 || (ntohs(utag->tag_len) != sizeof(sp))) {
 982                                         printf("no host unique field\n");
 983                                         LEAVE(ENETUNREACH);
 984                                 }
 985
 986                                 sendhook = pppoe_finduniq(node, utag);
 987                                 if (sendhook == NULL) {
 988                                         printf("no matching session\n");
 989                                         LEAVE(ENETUNREACH);
 990                                 }
 991
 992                                 /*
 993                                  * Check the session is in the right state.
 994                                  * It needs to be in PPPOE_SINIT.
 995                                  */
 996                                 sp = sendhook->private;
 997                                 if (sp->state != PPPOE_SINIT) {
 998                                         printf("session in wrong state\n");
 999                                         LEAVE(ENETUNREACH);
1000                                 }
1001                                 neg = sp->neg;
1002                                 untimeout(pppoe_ticker, sendhook,
1003                                     neg->timeout_handle);
1004
1005                                 /*
1006                                  * This is the first time we hear
1007                                  * from the server, so note it's
1008                                  * unicast address, replacing the
1009                                  * broadcast address .
1010                                  */
1011                                 bcopy(wh->eh.ether_shost,
1012                                         neg->pkt->pkt_header.eh.ether_dhost,
1013                                         ETHER_ADDR_LEN);
1014                                 neg->timeout = 0;
1015                                 neg->pkt->pkt_header.ph.code = PADR_CODE;
1016                                 init_tags(sp);
1017                                 insert_tag(sp, utag);      /* Host Unique */
1018                                 if ((tag = get_tag(ph, PTT_AC_COOKIE)))
1019                                         insert_tag(sp, tag); /* return cookie */
1020                                 if ((tag = get_tag(ph, PTT_AC_NAME))) {
1021                                         insert_tag(sp, tag); /* return it */
1022                                         send_acname(sp, tag);
1023                                 }
1024                                 insert_tag(sp, &neg->service.hdr); /* Service */
1025                                 scan_tags(sp, ph);
1026                                 make_packet(sp);
1027                                 sp->state = PPPOE_SREQ;
1028                                 sendpacket(sp);
1029                                 break;
1030                         case    PADR_CODE:
1031
1032                                 /*
1033                                  * We are a server:
1034                                  * Use the ac_cookie tag to find the
1035                                  * hook this is in response to.
1036                                  */
1037                                 utag = get_tag(ph, PTT_AC_COOKIE);
1038                                 if ((utag == NULL)
1039                                 || (ntohs(utag->tag_len) != sizeof(sp))) {
1040                                         LEAVE(ENETUNREACH);
1041                                 }
1042
1043                                 sendhook = pppoe_finduniq(node, utag);
1044                                 if (sendhook == NULL) {
1045                                         LEAVE(ENETUNREACH);
1046                                 }
1047
1048                                 /*
1049                                  * Check the session is in the right state.
1050                                  * It needs to be in PPPOE_SOFFER
1051                                  * or PPPOE_NEWCONNECTED. If the latter,
1052                                  * then this is a retry by the client.
1053                                  * so be nice, and resend.
1054                                  */
1055                                 sp = sendhook->private;
1056                                 if (sp->state == PPPOE_NEWCONNECTED) {
1057                                         /*
1058                                          * Whoa! drop back to resend that
1059                                          * PADS packet.
1060                                          * We should still have a copy of it.
1061                                          */
1062                                         sp->state = PPPOE_SOFFER;
1063                                 }
1064                                 if (sp->state != PPPOE_SOFFER) {
1065                                         LEAVE (ENETUNREACH);
1066                                         break;
1067                                 }
1068                                 neg = sp->neg;
1069                                 untimeout(pppoe_ticker, sendhook,
1070                                     neg->timeout_handle);
1071                                 neg->pkt->pkt_header.ph.code = PADS_CODE;
1072                                 if (sp->Session_ID == 0)
1073                                         neg->pkt->pkt_header.ph.sid =
1074                                             htons(sp->Session_ID
1075                                                 = get_new_sid(node));
1076                                 send_sessionid(sp);
1077                                 neg->timeout = 0;
1078                                 /*
1079                                  * start working out the tags to respond with.
1080                                  */
1081                                 init_tags(sp);
1082                                 insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1083                                 if ((tag = get_tag(ph, PTT_SRV_NAME)))
1084                                         insert_tag(sp, tag);/* return service */
1085                                 if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1086                                         insert_tag(sp, tag); /* return it */
1087                                 insert_tag(sp, utag);   /* ac_cookie */
1088                                 scan_tags(sp, ph);
1089                                 make_packet(sp);
1090                                 sp->state = PPPOE_NEWCONNECTED;
1091                                 sendpacket(sp);
1092                                 /*
1093                                  * Having sent the last Negotiation header,
1094                                  * Set up the stored packet header to
1095                                  * be correct for the actual session.
1096                                  * But keep the negotialtion stuff
1097                                  * around in case we need to resend this last
1098                                  * packet. We'll discard it when we move
1099                                  * from NEWCONNECTED to CONNECTED
1100                                  */
1101                                 sp->pkt_hdr = neg->pkt->pkt_header;
1102                                 if (nonstandard)
1103                                         sp->pkt_hdr.eh.ether_type
1104                                                 = ETHERTYPE_PPPOE_STUPID_SESS;
1105                                 else
1106                                         sp->pkt_hdr.eh.ether_type
1107                                                 = ETHERTYPE_PPPOE_SESS;
1108                                 sp->pkt_hdr.ph.code = 0;
1109                                 pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1110                                 break;
1111                         case    PADS_CODE:
1112                                 /*
1113                                  * We are a client:
1114                                  * Use the host_uniq tag to find the
1115                                  * hook this is in response to.
1116                                  * take the session ID and store it away.
1117                                  * Also make sure the pre-made header is
1118                                  * correct and set us into Session mode.
1119                                  */
1120                                 utag = get_tag(ph, PTT_HOST_UNIQ);
1121                                 if ((utag == NULL)
1122                                 || (ntohs(utag->tag_len) != sizeof(sp))) {
1123                                         LEAVE (ENETUNREACH);
1124                                         break;
1125                                 }
1126                                 sendhook = pppoe_finduniq(node, utag);
1127                                 if (sendhook == NULL) {
1128                                         LEAVE(ENETUNREACH);
1129                                 }
1130
1131                                 /*
1132                                  * Check the session is in the right state.
1133                                  * It needs to be in PPPOE_SREQ.
1134                                  */
1135                                 sp = sendhook->private;
1136                                 if (sp->state != PPPOE_SREQ) {
1137                                         LEAVE(ENETUNREACH);
1138                                 }
1139                                 neg = sp->neg;
1140                                 untimeout(pppoe_ticker, sendhook,
1141                                     neg->timeout_handle);
1142                                 neg->pkt->pkt_header.ph.sid = wh->ph.sid;
1143                                 sp->Session_ID = ntohs(wh->ph.sid);
1144                                 send_sessionid(sp);
1145                                 neg->timeout = 0;
1146                                 sp->state = PPPOE_CONNECTED;
1147                                 /*
1148                                  * Now we have gone to Connected mode,
1149                                  * Free all resources needed for
1150                                  * negotiation.
1151                                  * Keep a copy of the header we will be using.
1152                                  */
1153                                 sp->pkt_hdr = neg->pkt->pkt_header;
1154                                 if (nonstandard)
1155                                         sp->pkt_hdr.eh.ether_type
1156                                                 = ETHERTYPE_PPPOE_STUPID_SESS;
1157                                 else
1158                                         sp->pkt_hdr.eh.ether_type
1159                                                 = ETHERTYPE_PPPOE_SESS;
1160                                 sp->pkt_hdr.ph.code = 0;
1161                                 m_freem(neg->m);
1162                                 FREE(sp->neg, M_NETGRAPH);
1163                                 sp->neg = NULL;
1164                                 pppoe_send_event(sp, NGM_PPPOE_SUCCESS);
1165                                 break;
1166                         case    PADT_CODE:
1167                                 /*
1168                                  * Send a 'close' message to the controlling
1169                                  * process (the one that set us up);
1170                                  * And then tear everything down.
1171                                  *
1172                                  * Find matching peer/session combination.
1173                                  */
1174                                 sendhook = pppoe_findsession(node, wh);
1175                                 NG_FREE_DATA(m, meta); /* no longer needed */
1176                                 if (sendhook == NULL) {
1177                                         LEAVE(ENETUNREACH);
1178                                 }
1179                                 /* send message to creator */
1180                                 /* close hook */
1181                                 if (sendhook) {
1182                                         ng_destroy_hook(sendhook);
1183                                 }
1184                                 break;
1185                         default:
1186                                 LEAVE(EPFNOSUPPORT);
1187                         }
1188                         break;
1189                 case    ETHERTYPE_PPPOE_STUPID_SESS:
1190                 case    ETHERTYPE_PPPOE_SESS:
1191                         /*
1192                          * find matching peer/session combination.
1193                          */
1194                         sendhook = pppoe_findsession(node, wh);
1195                         if (sendhook == NULL) {
1196                                 LEAVE (ENETUNREACH);
1197                                 break;
1198                         }
1199                         sp = sendhook->private;
1200                         m_adj(m, sizeof(*wh));
1201                         if (m->m_pkthdr.len < length) {
1202                                 /* Packet too short, dump it */
1203                                 LEAVE(EMSGSIZE);
1204                         }
1205
1206                         /* Also need to trim excess at the end */
1207                         if (m->m_pkthdr.len > length) {
1208                                 m_adj(m, -((int)(m->m_pkthdr.len - length)));
1209                         }
1210                         if ( sp->state != PPPOE_CONNECTED) {
1211                                 if (sp->state == PPPOE_NEWCONNECTED) {
1212                                         sp->state = PPPOE_CONNECTED;
1213                                         /*
1214                                          * Now we have gone to Connected mode,
1215                                          * Free all resources needed for
1216                                          * negotiation. Be paranoid about
1217                                          * whether there may be a timeout.
1218                                          */
1219                                         m_freem(sp->neg->m);
1220                                         untimeout(pppoe_ticker, sendhook,
1221                                                 sp->neg->timeout_handle);
1222                                         FREE(sp->neg, M_NETGRAPH);
1223                                         sp->neg = NULL;
1224                                 } else {
1225                                         LEAVE (ENETUNREACH);
1226                                         break;
1227                                 }
1228                         }
1229                         NG_SEND_DATA( error, sendhook, m, meta);
1230                         break;
1231                 default:
1232                         LEAVE(EPFNOSUPPORT);
1233                 }
1234         } else {
1235                 /*
1236                  *      Not ethernet or debug hook..
1237                  *
1238                  * The packet has come in on a normal hook.
1239                  * We need to find out what kind of hook,
1240                  * So we can decide how to handle it.
1241                  * Check the hook's state.
1242                  */
1243                 sp = hook->private;
1244                 switch (sp->state) {
1245                 case    PPPOE_NEWCONNECTED:
1246                 case    PPPOE_CONNECTED: {
1247                         static const u_char addrctrl[] = { 0xff, 0x03 };
1248                         struct pppoe_full_hdr *wh;
1249
1250                         /*
1251                          * Remove PPP address and control fields, if any.
1252                          * For example, ng_ppp(4) always sends LCP packets
1253                          * with address and control fields as required by
1254                          * generic PPP. PPPoE is an exception to the rule.
1255                          */
1256                         if (m->m_pkthdr.len >= 2) {
1257                                 if (m->m_len < 2 && !(m = m_pullup(m, 2)))
1258                                         LEAVE(ENOBUFS);
1259                                 if (bcmp(mtod(m, u_char *), addrctrl, 2) == 0)
1260                                         m_adj(m, 2);
1261                         }
1262                         /*
1263                          * Bang in a pre-made header, and set the length up
1264                          * to be correct. Then send it to the ethernet driver.
1265                          * But first correct the length.
1266                          */
1267                         sp->pkt_hdr.ph.length = htons((short)(m->m_pkthdr.len));
1268                         M_PREPEND(m, sizeof(*wh), M_DONTWAIT);
1269                         if (m == NULL) {
1270                                 LEAVE(ENOBUFS);
1271                         }
1272                         wh = mtod(m, struct pppoe_full_hdr *);
1273                         bcopy(&sp->pkt_hdr, wh, sizeof(*wh));
1274                         NG_SEND_DATA( error, privp->ethernet_hook, m, meta);
1275                         privp->packets_out++;
1276                         break;
1277                         }
1278                 case    PPPOE_PRIMED:
1279                         /*
1280                          * A PADI packet is being returned by the application
1281                          * that has set up this hook. This indicates that it
1282                          * wants us to offer service.
1283                          */
1284                         neg = sp->neg;
1285                         if (m->m_len < sizeof(*wh)) {
1286                                 m = m_pullup(m, sizeof(*wh));
1287                                 if (m == NULL) {
1288                                         LEAVE(ENOBUFS);
1289                                 }
1290                         }
1291                         wh = mtod(m, struct pppoe_full_hdr *);
1292                         ph = &wh->ph;
1293                         session = ntohs(wh->ph.sid);
1294                         length = ntohs(wh->ph.length);
1295                         code = wh->ph.code;
1296                         if ( code != PADI_CODE) {
1297                                 LEAVE(EINVAL);
1298                         };
1299                         untimeout(pppoe_ticker, hook,
1300                                     neg->timeout_handle);
1301
1302                         /*
1303                          * This is the first time we hear
1304                          * from the client, so note it's
1305                          * unicast address, replacing the
1306                          * broadcast address.
1307                          */
1308                         bcopy(wh->eh.ether_shost,
1309                                 neg->pkt->pkt_header.eh.ether_dhost,
1310                                 ETHER_ADDR_LEN);
1311                         sp->state = PPPOE_SOFFER;
1312                         neg->timeout = 0;
1313                         neg->pkt->pkt_header.ph.code = PADO_CODE;
1314
1315                         /*
1316                          * start working out the tags to respond with.
1317                          */
1318                         uniqtag.hdr.tag_type = PTT_AC_COOKIE;
1319                         uniqtag.hdr.tag_len = htons((u_int16_t)sizeof(sp));
1320                         uniqtag.data.pointer = sp;
1321                         init_tags(sp);
1322                         insert_tag(sp, &neg->ac_name.hdr); /* AC_NAME */
1323                         if ((tag = get_tag(ph, PTT_SRV_NAME)))
1324                                 insert_tag(sp, tag);      /* return service */
1325                         /*
1326                          * If we have a NULL service request
1327                          * and have an extra service defined in this hook,
1328                          * then also add a tag for the extra service.
1329                          * XXX this is a hack. eventually we should be able
1330                          * to support advertising many services, not just one
1331                          */
1332                         if (((tag == NULL) || (tag->tag_len == 0))
1333                         && (neg->service.hdr.tag_len != 0)) {
1334                                 insert_tag(sp, &neg->service.hdr); /* SERVICE */
1335                         }
1336                         if ((tag = get_tag(ph, PTT_HOST_UNIQ)))
1337                                 insert_tag(sp, tag); /* returned hostunique */
1338                         insert_tag(sp, &uniqtag.hdr);
1339                         scan_tags(sp, ph);
1340                         make_packet(sp);
1341                         sendpacket(sp);
1342                         break;
1343
1344                 /*
1345                  * Packets coming from the hook make no sense
1346                  * to sessions in these states. Throw them away.
1347                  */
1348                 case    PPPOE_SINIT:
1349                 case    PPPOE_SREQ:
1350                 case    PPPOE_SOFFER:
1351                 case    PPPOE_SNONE:
1352                 case    PPPOE_LISTENING:
1353                 case    PPPOE_DEAD:
1354                 default:
1355                         LEAVE(ENETUNREACH);
1356                 }
1357         }
1358 quit:
1359         NG_FREE_DATA(m, meta);
1360         return error;
1361 }
1362
1363 /*
1364  * Do local shutdown processing..
1365  * If we are a persistant device, we might refuse to go away, and
1366  * we'd only remove our links and reset ourself.
1367  */
1368 static int
1369 ng_pppoe_rmnode(node_p node)
1370 {
1371         const priv_p privdata = node->private;
1372
1373 AAA
1374         node->flags |= NG_INVALID;
1375         ng_cutlinks(node);
1376         ng_unname(node);
1377         node->private = NULL;
1378         ng_unref(privdata->node);
1379         FREE(privdata, M_NETGRAPH);
1380         return (0);
1381 }
1382
1383 /*
1384  * This is called once we've already connected a new hook to the other node.
1385  * It gives us a chance to balk at the last minute.
1386  */
1387 static int
1388 ng_pppoe_connect(hook_p hook)
1389 {
1390         /* be really amiable and just say "YUP that's OK by me! " */
1391         return (0);
1392 }
1393
1394 /*
1395  * Hook disconnection
1396  *
1397  * Clean up all dangling links and information about the session/hook.
1398  * For this type, removal of the last link destroys the node
1399  */
1400 static int
1401 ng_pppoe_disconnect(hook_p hook)
1402 {
1403         node_p node = hook->node;
1404         priv_p privp = node->private;
1405         sessp   sp;
1406         int     hooks;
1407
1408 AAA
1409         hooks = node->numhooks; /* this one already not counted */
1410         if (hook->private == &privp->debug_hook) {
1411                 privp->debug_hook = NULL;
1412         } else if (hook->private == &privp->ethernet_hook) {
1413                 privp->ethernet_hook = NULL;
1414                 ng_rmnode(node);
1415         } else {
1416                 sp = hook->private;
1417                 if (sp->state != PPPOE_SNONE ) {
1418                         pppoe_send_event(sp, NGM_PPPOE_CLOSE);
1419                 }
1420                 /*
1421                  * According to the spec, if we are connected,
1422                  * we should send a DISC packet if we are shutting down
1423                  * a session.
1424                  */
1425                 if ((privp->ethernet_hook)
1426                 && ((sp->state == PPPOE_CONNECTED)
1427                  || (sp->state == PPPOE_NEWCONNECTED))) {
1428                         struct mbuf *m;
1429                         struct pppoe_full_hdr *wh;
1430                         struct pppoe_tag *tag;
1431                         int     msglen = strlen(SIGNOFF);
1432                         void *dummy = NULL;
1433                         int error = 0;
1434
1435                         /* revert the stored header to DISC/PADT mode */
1436                         wh = &sp->pkt_hdr;
1437                         wh->ph.code = PADT_CODE;
1438                         if (nonstandard)
1439                                 wh->eh.ether_type = ETHERTYPE_PPPOE_STUPID_DISC;
1440                         else
1441                                 wh->eh.ether_type = ETHERTYPE_PPPOE_DISC;
1442
1443                         /* generate a packet of that type */
1444                         MGETHDR(m, M_DONTWAIT, MT_DATA);
1445                         if(m == NULL)
1446                                 printf("pppoe: Session out of mbufs\n");
1447                         else {
1448                                 m->m_pkthdr.rcvif = NULL;
1449                                 m->m_pkthdr.len = m->m_len = sizeof(*wh);
1450                                 bcopy((caddr_t)wh, mtod(m, caddr_t),
1451                                     sizeof(*wh));
1452                                 /*
1453                                  * Add a General error message and adjust
1454                                  * sizes
1455                                  */
1456                                 wh = mtod(m, struct pppoe_full_hdr *);
1457                                 tag = wh->ph.tag;
1458                                 tag->tag_type = PTT_GEN_ERR;
1459                                 tag->tag_len = htons((u_int16_t)msglen);
1460                                 strncpy(tag->tag_data, SIGNOFF, msglen);
1461                                 m->m_pkthdr.len = (m->m_len += sizeof(*tag) +
1462                                     msglen);
1463                                 wh->ph.length = htons(sizeof(*tag) + msglen);
1464                                 NG_SEND_DATA(error, privp->ethernet_hook, m,
1465                                     dummy);
1466                         }
1467                 }
1468                 /*
1469                  * As long as we have somewhere to store the timeout handle,
1470                  * we may have a timeout pending.. get rid of it.
1471                  */
1472                 if (sp->neg) {
1473                         untimeout(pppoe_ticker, hook, sp->neg->timeout_handle);
1474                         if (sp->neg->m)
1475                                 m_freem(sp->neg->m);
1476                         FREE(sp->neg, M_NETGRAPH);
1477                 }
1478                 FREE(sp, M_NETGRAPH);
1479                 hook->private = NULL;
1480                 /* work out how many session hooks there are */
1481                 /* Node goes away on last session hook removal */
1482                 if (privp->ethernet_hook) hooks -= 1;
1483                 if (privp->debug_hook) hooks -= 1;
1484         }
1485         if (node->numhooks == 0)
1486                 ng_rmnode(node);
1487         return (0);
1488 }
1489
1490 /*
1491  * timeouts come here.
1492  */
1493 static void
1494 pppoe_ticker(void *arg)
1495 {
1496         int s = splnet();
1497         hook_p hook = arg;
1498         sessp   sp = hook->private;
1499         negp    neg = sp->neg;
1500         int     error = 0;
1501         struct mbuf *m0 = NULL;
1502         priv_p privp = hook->node->private;
1503         meta_p dummy = NULL;
1504
1505 AAA
1506         switch(sp->state) {
1507                 /*
1508                  * resend the last packet, using an exponential backoff.
1509                  * After a period of time, stop growing the backoff,
1510                  * and either leave it, or revert to the start.
1511                  */
1512         case    PPPOE_SINIT:
1513         case    PPPOE_SREQ:
1514                 /* timeouts on these produce resends */
1515                 m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1516                 NG_SEND_DATA( error, privp->ethernet_hook, m0, dummy);
1517                 neg->timeout_handle = timeout(pppoe_ticker,
1518                                         hook, neg->timeout * hz);
1519                 if ((neg->timeout <<= 1) > PPPOE_TIMEOUT_LIMIT) {
1520                         if (sp->state == PPPOE_SREQ) {
1521                                 /* revert to SINIT mode */
1522                                 pppoe_start(sp);
1523                         } else {
1524                                 neg->timeout = PPPOE_TIMEOUT_LIMIT;
1525                         }
1526                 }
1527                 break;
1528         case    PPPOE_PRIMED:
1529         case    PPPOE_SOFFER:
1530                 /* a timeout on these says "give up" */
1531                 ng_destroy_hook(hook);
1532                 break;
1533         default:
1534                 /* timeouts have no meaning in other states */
1535                 printf("pppoe: unexpected timeout\n");
1536         }
1537         splx(s);
1538 }
1539
1540
1541 static void
1542 sendpacket(sessp sp)
1543 {
1544         int     error = 0;
1545         struct mbuf *m0 = NULL;
1546         hook_p hook = sp->hook;
1547         negp    neg = sp->neg;
1548         priv_p  privp = hook->node->private;
1549         meta_p dummy = NULL;
1550
1551 AAA
1552         switch(sp->state) {
1553         case    PPPOE_LISTENING:
1554         case    PPPOE_DEAD:
1555         case    PPPOE_SNONE:
1556         case    PPPOE_CONNECTED:
1557                 printf("pppoe: sendpacket: unexpected state\n");
1558                 break;
1559
1560         case    PPPOE_NEWCONNECTED:
1561                 /* send the PADS without a timeout - we're now connected */
1562                 m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1563                 NG_SEND_DATA( error, privp->ethernet_hook, m0, dummy);
1564                 break;
1565
1566         case    PPPOE_PRIMED:
1567                 /* No packet to send, but set up the timeout */
1568                 neg->timeout_handle = timeout(pppoe_ticker,
1569                                         hook, PPPOE_OFFER_TIMEOUT * hz);
1570                 break;
1571
1572         case    PPPOE_SOFFER:
1573                 /*
1574                  * send the offer but if they don't respond
1575                  * in PPPOE_OFFER_TIMEOUT seconds, forget about it.
1576                  */
1577                 m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1578                 NG_SEND_DATA( error, privp->ethernet_hook, m0, dummy);
1579                 neg->timeout_handle = timeout(pppoe_ticker,
1580                                         hook, PPPOE_OFFER_TIMEOUT * hz);
1581                 break;
1582
1583         case    PPPOE_SINIT:
1584         case    PPPOE_SREQ:
1585                 m0 = m_copypacket(sp->neg->m, M_DONTWAIT);
1586                 NG_SEND_DATA( error, privp->ethernet_hook, m0, dummy);
1587                 neg->timeout_handle = timeout(pppoe_ticker, hook,
1588                                         (hz * PPPOE_INITIAL_TIMEOUT));
1589                 neg->timeout = PPPOE_INITIAL_TIMEOUT * 2;
1590                 break;
1591
1592         default:
1593                 error = EINVAL;
1594                 printf("pppoe: timeout: bad state\n");
1595         }
1596         /* return (error); */
1597 }
1598
1599 /*
1600  * Parse an incoming packet to see if any tags should be copied to the
1601  * output packet. Don't do any tags that have been handled in the main
1602  * state machine.
1603  */
1604 static const struct pppoe_tag*
1605 scan_tags(sessp sp, const struct pppoe_hdr* ph)
1606 {
1607         const char *const end = (const char *)next_tag(ph);
1608         const char *ptn;
1609         const struct pppoe_tag *pt = &ph->tag[0];
1610         /*
1611          * Keep processing tags while a tag header will still fit.
1612          */
1613 AAA
1614         while((const char*)(pt + 1) <= end) {
1615                 /*
1616                  * If the tag data would go past the end of the packet, abort.
1617                  */
1618                 ptn = (((const char *)(pt + 1)) + ntohs(pt->tag_len));
1619                 if(ptn > end)
1620                         return NULL;
1621
1622                 switch (pt->tag_type) {
1623                 case    PTT_RELAY_SID:
1624                         insert_tag(sp, pt);
1625                         break;
1626                 case    PTT_EOL:
1627                         return NULL;
1628                 case    PTT_SRV_NAME:
1629                 case    PTT_AC_NAME:
1630                 case    PTT_HOST_UNIQ:
1631                 case    PTT_AC_COOKIE:
1632                 case    PTT_VENDOR:
1633                 case    PTT_SRV_ERR:
1634                 case    PTT_SYS_ERR:
1635                 case    PTT_GEN_ERR:
1636                         break;
1637                 }
1638                 pt = (const struct pppoe_tag*)ptn;
1639         }
1640         return NULL;
1641 }
1642
1643 static  int
1644 pppoe_send_event(sessp sp, enum cmd cmdid)
1645 {
1646         int error;
1647         struct ng_mesg *msg;
1648         struct ngpppoe_sts *sts;
1649
1650 AAA
1651         NG_MKMESSAGE(msg, NGM_PPPOE_COOKIE, cmdid,
1652                         sizeof(struct ngpppoe_sts), M_NOWAIT);
1653         if (msg == NULL)
1654                 return (ENOMEM);
1655         sts = (struct ngpppoe_sts *)msg->data;
1656         strncpy(sts->hook, sp->hook->name, NG_HOOKLEN + 1);
1657         error = ng_send_msg(sp->hook->node, msg, sp->creator, NULL);
1658         return (error);
1659 }