The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_lmi.c

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    1 /*
    2  * ng_lmi.c
    3  */
    4 
    5 /*-
    6  * Copyright (c) 1996-1999 Whistle Communications, Inc.
    7  * All rights reserved.
    8  * 
    9  * Subject to the following obligations and disclaimer of warranty, use and
   10  * redistribution of this software, in source or object code forms, with or
   11  * without modifications are expressly permitted by Whistle Communications;
   12  * provided, however, that:
   13  * 1. Any and all reproductions of the source or object code must include the
   14  *    copyright notice above and the following disclaimer of warranties; and
   15  * 2. No rights are granted, in any manner or form, to use Whistle
   16  *    Communications, Inc. trademarks, including the mark "WHISTLE
   17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
   18  *    such appears in the above copyright notice or in the software.
   19  * 
   20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
   21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
   22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
   23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
   24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
   25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
   26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
   27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
   28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
   29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
   30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
   31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
   32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
   33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
   36  * OF SUCH DAMAGE.
   37  *
   38  * Author: Julian Elischer <julian@freebsd.org>
   39  *
   40  * $FreeBSD: releng/9.2/sys/netgraph/ng_lmi.c 220768 2011-04-18 09:12:27Z glebius $
   41  * $Whistle: ng_lmi.c,v 1.38 1999/11/01 09:24:52 julian Exp $
   42  */
   43 
   44 /*
   45  * This node performs the frame relay LMI protocol. It knows how
   46  * to do ITU Annex A, ANSI Annex D, and "Group-of-Four" variants
   47  * of the protocol.
   48  *
   49  * A specific protocol can be forced by connecting the corresponding
   50  * hook to DLCI 0 or 1023 (as appropriate) of a frame relay link.
   51  *
   52  * Alternately, this node can do auto-detection of the LMI protocol
   53  * by connecting hook "auto0" to DLCI 0 and "auto1023" to DLCI 1023.
   54  */
   55 
   56 #include <sys/param.h>
   57 #include <sys/systm.h>
   58 #include <sys/errno.h>
   59 #include <sys/kernel.h>
   60 #include <sys/malloc.h>
   61 #include <sys/mbuf.h>
   62 #include <sys/syslog.h>
   63 #include <netgraph/ng_message.h>
   64 #include <netgraph/netgraph.h>
   65 #include <netgraph/ng_lmi.h>
   66 
   67 /*
   68  * Human readable names for LMI
   69  */
   70 #define NAME_ANNEXA     NG_LMI_HOOK_ANNEXA
   71 #define NAME_ANNEXD     NG_LMI_HOOK_ANNEXD
   72 #define NAME_GROUP4     NG_LMI_HOOK_GROUPOF4
   73 #define NAME_NONE       "None"
   74 
   75 #define MAX_DLCIS       128
   76 #define MAXDLCI         1023
   77 
   78 /*
   79  * DLCI states
   80  */
   81 #define DLCI_NULL       0
   82 #define DLCI_UP         1
   83 #define DLCI_DOWN       2
   84 
   85 /*
   86  * Any received LMI frame should be at least this long
   87  */
   88 #define LMI_MIN_LENGTH  8       /* XXX verify */
   89 
   90 /*
   91  * Netgraph node methods and type descriptor
   92  */
   93 static ng_constructor_t nglmi_constructor;
   94 static ng_rcvmsg_t      nglmi_rcvmsg;
   95 static ng_shutdown_t    nglmi_shutdown;
   96 static ng_newhook_t     nglmi_newhook;
   97 static ng_rcvdata_t     nglmi_rcvdata;
   98 static ng_disconnect_t  nglmi_disconnect;
   99 static int      nglmi_checkdata(hook_p hook, struct mbuf *m);
  100 
  101 static struct ng_type typestruct = {
  102         .version =      NG_ABI_VERSION,
  103         .name =         NG_LMI_NODE_TYPE,
  104         .constructor =  nglmi_constructor,
  105         .rcvmsg =       nglmi_rcvmsg,
  106         .shutdown =     nglmi_shutdown,
  107         .newhook =      nglmi_newhook,
  108         .rcvdata =      nglmi_rcvdata,
  109         .disconnect =   nglmi_disconnect,
  110 };
  111 NETGRAPH_INIT(lmi, &typestruct);
  112 
  113 /*
  114  * Info and status per node
  115  */
  116 struct nglmi_softc {
  117         node_p  node;           /* netgraph node */
  118         int     flags;          /* state */
  119         int     poll_count;     /* the count of times for autolmi */
  120         int     poll_state;     /* state of auto detect machine */
  121         u_char  remote_seq;     /* sequence number the remote sent */
  122         u_char  local_seq;      /* last sequence number we sent */
  123         u_char  protoID;        /* 9 for group of 4, 8 otherwise */
  124         u_long  seq_retries;    /* sent this how many time so far */
  125         struct  callout handle; /* see timeout(9) */
  126         int     liv_per_full;
  127         int     liv_rate;
  128         int     livs;
  129         int     need_full;
  130         hook_p  lmi_channel;    /* whatever we ended up using */
  131         hook_p  lmi_annexA;
  132         hook_p  lmi_annexD;
  133         hook_p  lmi_group4;
  134         hook_p  lmi_channel0;   /* auto-detect on DLCI 0 */
  135         hook_p  lmi_channel1023;/* auto-detect on DLCI 1023 */
  136         char   *protoname;      /* cache protocol name */
  137         u_char  dlci_state[MAXDLCI + 1];
  138         int     invalidx;       /* next dlci's to invalidate */
  139 };
  140 typedef struct nglmi_softc *sc_p;
  141 
  142 /*
  143  * Other internal functions
  144  */
  145 static void     LMI_ticker(node_p node, hook_p hook, void *arg1, int arg2);
  146 static void     nglmi_startup_fixed(sc_p sc, hook_p hook);
  147 static void     nglmi_startup_auto(sc_p sc);
  148 static void     nglmi_startup(sc_p sc);
  149 static void     nglmi_inquire(sc_p sc, int full);
  150 static void     ngauto_state_machine(sc_p sc);
  151 
  152 /*
  153  * Values for 'flags' field
  154  * NB: the SCF_CONNECTED flag is set if and only if the timer is running.
  155  */
  156 #define SCF_CONNECTED   0x01    /* connected to something */
  157 #define SCF_AUTO        0x02    /* we are auto-detecting */
  158 #define SCF_FIXED       0x04    /* we are fixed from the start */
  159 
  160 #define SCF_LMITYPE     0x18    /* mask for determining Annex mode */
  161 #define SCF_NOLMI       0x00    /* no LMI type selected yet */
  162 #define SCF_ANNEX_A     0x08    /* running annex A mode */
  163 #define SCF_ANNEX_D     0x10    /* running annex D mode */
  164 #define SCF_GROUP4      0x18    /* running group of 4 */
  165 
  166 #define SETLMITYPE(sc, annex)                                           \
  167 do {                                                                    \
  168         (sc)->flags &= ~SCF_LMITYPE;                                    \
  169         (sc)->flags |= (annex);                                         \
  170 } while (0)
  171 
  172 #define NOPROTO(sc) (((sc)->flags & SCF_LMITYPE) == SCF_NOLMI)
  173 #define ANNEXA(sc) (((sc)->flags & SCF_LMITYPE) == SCF_ANNEX_A)
  174 #define ANNEXD(sc) (((sc)->flags & SCF_LMITYPE) == SCF_ANNEX_D)
  175 #define GROUP4(sc) (((sc)->flags & SCF_LMITYPE) == SCF_GROUP4)
  176 
  177 #define LMIPOLLSIZE     3
  178 #define LMI_PATIENCE    8       /* declare all DLCI DOWN after N LMI failures */
  179 
  180 /*
  181  * Node constructor
  182  */
  183 static int
  184 nglmi_constructor(node_p node)
  185 {
  186         sc_p sc;
  187 
  188         sc = malloc(sizeof(*sc), M_NETGRAPH, M_WAITOK | M_ZERO);
  189 
  190         NG_NODE_SET_PRIVATE(node, sc);
  191         sc->node = node;
  192 
  193         ng_callout_init(&sc->handle);
  194         sc->protoname = NAME_NONE;
  195         sc->liv_per_full = NG_LMI_SEQ_PER_FULL; /* make this dynamic */
  196         sc->liv_rate = NG_LMI_KEEPALIVE_RATE;
  197         return (0);
  198 }
  199 
  200 /*
  201  * The LMI channel has a private pointer which is the same as the
  202  * node private pointer. The debug channel has a NULL private pointer.
  203  */
  204 static int
  205 nglmi_newhook(node_p node, hook_p hook, const char *name)
  206 {
  207         sc_p sc = NG_NODE_PRIVATE(node);
  208 
  209         if (strcmp(name, NG_LMI_HOOK_DEBUG) == 0) {
  210                 NG_HOOK_SET_PRIVATE(hook, NULL);
  211                 return (0);
  212         }
  213         if (sc->flags & SCF_CONNECTED) {
  214                 /* already connected, return an error */
  215                 return (EINVAL);
  216         }
  217         if (strcmp(name, NG_LMI_HOOK_ANNEXA) == 0) {
  218                 sc->lmi_annexA = hook;
  219                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  220                 sc->protoID = 8;
  221                 SETLMITYPE(sc, SCF_ANNEX_A);
  222                 sc->protoname = NAME_ANNEXA;
  223                 nglmi_startup_fixed(sc, hook);
  224         } else if (strcmp(name, NG_LMI_HOOK_ANNEXD) == 0) {
  225                 sc->lmi_annexD = hook;
  226                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  227                 sc->protoID = 8;
  228                 SETLMITYPE(sc, SCF_ANNEX_D);
  229                 sc->protoname = NAME_ANNEXD;
  230                 nglmi_startup_fixed(sc, hook);
  231         } else if (strcmp(name, NG_LMI_HOOK_GROUPOF4) == 0) {
  232                 sc->lmi_group4 = hook;
  233                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  234                 sc->protoID = 9;
  235                 SETLMITYPE(sc, SCF_GROUP4);
  236                 sc->protoname = NAME_GROUP4;
  237                 nglmi_startup_fixed(sc, hook);
  238         } else if (strcmp(name, NG_LMI_HOOK_AUTO0) == 0) {
  239                 /* Note this, and if B is already installed, we're complete */
  240                 sc->lmi_channel0 = hook;
  241                 sc->protoname = NAME_NONE;
  242                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  243                 if (sc->lmi_channel1023)
  244                         nglmi_startup_auto(sc);
  245         } else if (strcmp(name, NG_LMI_HOOK_AUTO1023) == 0) {
  246                 /* Note this, and if A is already installed, we're complete */
  247                 sc->lmi_channel1023 = hook;
  248                 sc->protoname = NAME_NONE;
  249                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  250                 if (sc->lmi_channel0)
  251                         nglmi_startup_auto(sc);
  252         } else
  253                 return (EINVAL);                /* unknown hook */
  254         return (0);
  255 }
  256 
  257 /*
  258  * We have just attached to a live (we hope) node.
  259  * Fire out a LMI inquiry, and then start up the timers.
  260  */
  261 static void
  262 LMI_ticker(node_p node, hook_p hook, void *arg1, int arg2)
  263 {
  264         sc_p sc = NG_NODE_PRIVATE(node);
  265 
  266         if (sc->flags & SCF_AUTO) {
  267                 ngauto_state_machine(sc);
  268                 ng_callout(&sc->handle, node, NULL, NG_LMI_POLL_RATE * hz,
  269                     LMI_ticker, NULL, 0);
  270         } else {
  271                 if (sc->livs++ >= sc->liv_per_full) {
  272                         nglmi_inquire(sc, 1);
  273                         /* sc->livs = 0; *//* do this when we get the answer! */
  274                 } else {
  275                         nglmi_inquire(sc, 0);
  276                 }
  277                 ng_callout(&sc->handle, node, NULL, sc->liv_rate * hz,
  278                     LMI_ticker, NULL, 0);
  279         }
  280 }
  281 
  282 static void
  283 nglmi_startup_fixed(sc_p sc, hook_p hook)
  284 {
  285         sc->flags |= (SCF_FIXED | SCF_CONNECTED);
  286         sc->lmi_channel = hook;
  287         nglmi_startup(sc);
  288 }
  289 
  290 static void
  291 nglmi_startup_auto(sc_p sc)
  292 {
  293         sc->flags |= (SCF_AUTO | SCF_CONNECTED);
  294         sc->poll_state = 0;     /* reset state machine */
  295         sc->poll_count = 0;
  296         nglmi_startup(sc);
  297 }
  298 
  299 static void
  300 nglmi_startup(sc_p sc)
  301 {
  302         sc->remote_seq = 0;
  303         sc->local_seq = 1;
  304         sc->seq_retries = 0;
  305         sc->livs = sc->liv_per_full - 1;
  306         /* start off the ticker in 1 sec */
  307         ng_callout(&sc->handle, sc->node, NULL, hz, LMI_ticker, NULL, 0);
  308 }
  309 
  310 static void
  311 nglmi_inquire(sc_p sc, int full)
  312 {
  313         struct mbuf *m;
  314         struct ng_tag_prio *ptag;
  315         char   *cptr, *start;
  316         int     error;
  317 
  318         if (sc->lmi_channel == NULL)
  319                 return;
  320         MGETHDR(m, M_DONTWAIT, MT_DATA);
  321         if (m == NULL) {
  322                 log(LOG_ERR, "nglmi: unable to start up LMI processing\n");
  323                 return;
  324         }
  325         m->m_pkthdr.rcvif = NULL;
  326 
  327         /* Attach a tag to packet, marking it of link level state priority, so
  328          * that device driver would put it in the beginning of queue */
  329 
  330         ptag = (struct ng_tag_prio *)m_tag_alloc(NGM_GENERIC_COOKIE, NG_TAG_PRIO,
  331             (sizeof(struct ng_tag_prio) - sizeof(struct m_tag)), M_NOWAIT);
  332         if (ptag != NULL) {     /* if it failed, well, it was optional anyhow */
  333                 ptag->priority = NG_PRIO_LINKSTATE;
  334                 ptag->discardability = -1;
  335                 m_tag_prepend(m, &ptag->tag);
  336         }
  337 
  338         m->m_data += 4;         /* leave some room for a header */
  339         cptr = start = mtod(m, char *);
  340         /* add in the header for an LMI inquiry. */
  341         *cptr++ = 0x03;         /* UI frame */
  342         if (GROUP4(sc))
  343                 *cptr++ = 0x09; /* proto discriminator */
  344         else
  345                 *cptr++ = 0x08; /* proto discriminator */
  346         *cptr++ = 0x00;         /* call reference */
  347         *cptr++ = 0x75;         /* inquiry */
  348 
  349         /* If we are Annex-D, add locking shift to codeset 5. */
  350         if (ANNEXD(sc))
  351                 *cptr++ = 0x95; /* locking shift */
  352         /* Add a request type */
  353         if (ANNEXA(sc))
  354                 *cptr++ = 0x51; /* report type */
  355         else
  356                 *cptr++ = 0x01; /* report type */
  357         *cptr++ = 0x01;         /* size = 1 */
  358         if (full)
  359                 *cptr++ = 0x00; /* full */
  360         else
  361                 *cptr++ = 0x01; /* partial */
  362 
  363         /* Add a link verification IE */
  364         if (ANNEXA(sc))
  365                 *cptr++ = 0x53; /* verification IE */
  366         else
  367                 *cptr++ = 0x03; /* verification IE */
  368         *cptr++ = 0x02;         /* 2 extra bytes */
  369         *cptr++ = sc->local_seq;
  370         *cptr++ = sc->remote_seq;
  371         sc->seq_retries++;
  372 
  373         /* Send it */
  374         m->m_len = m->m_pkthdr.len = cptr - start;
  375         NG_SEND_DATA_ONLY(error, sc->lmi_channel, m);
  376 
  377         /* If we've been sending requests for long enough, and there has
  378          * been no response, then mark as DOWN, any DLCIs that are UP. */
  379         if (sc->seq_retries == LMI_PATIENCE) {
  380                 int     count;
  381 
  382                 for (count = 0; count < MAXDLCI; count++)
  383                         if (sc->dlci_state[count] == DLCI_UP)
  384                                 sc->dlci_state[count] = DLCI_DOWN;
  385         }
  386 }
  387 
  388 /*
  389  * State machine for LMI auto-detect. The transitions are ordered
  390  * to try the more likely possibilities first.
  391  */
  392 static void
  393 ngauto_state_machine(sc_p sc)
  394 {
  395         if ((sc->poll_count <= 0) || (sc->poll_count > LMIPOLLSIZE)) {
  396                 /* time to change states in the auto probe machine */
  397                 /* capture wild values of poll_count while we are at it */
  398                 sc->poll_count = LMIPOLLSIZE;
  399                 sc->poll_state++;
  400         }
  401         switch (sc->poll_state) {
  402         case 7:
  403                 log(LOG_WARNING, "nglmi: no response from exchange\n");
  404         default:                /* capture bad states */
  405                 sc->poll_state = 1;
  406         case 1:
  407                 sc->lmi_channel = sc->lmi_channel0;
  408                 SETLMITYPE(sc, SCF_ANNEX_D);
  409                 break;
  410         case 2:
  411                 sc->lmi_channel = sc->lmi_channel1023;
  412                 SETLMITYPE(sc, SCF_ANNEX_D);
  413                 break;
  414         case 3:
  415                 sc->lmi_channel = sc->lmi_channel0;
  416                 SETLMITYPE(sc, SCF_ANNEX_A);
  417                 break;
  418         case 4:
  419                 sc->lmi_channel = sc->lmi_channel1023;
  420                 SETLMITYPE(sc, SCF_GROUP4);
  421                 break;
  422         case 5:
  423                 sc->lmi_channel = sc->lmi_channel1023;
  424                 SETLMITYPE(sc, SCF_ANNEX_A);
  425                 break;
  426         case 6:
  427                 sc->lmi_channel = sc->lmi_channel0;
  428                 SETLMITYPE(sc, SCF_GROUP4);
  429                 break;
  430         }
  431 
  432         /* send an inquirey encoded appropriatly */
  433         nglmi_inquire(sc, 0);
  434         sc->poll_count--;
  435 }
  436 
  437 /*
  438  * Receive a netgraph control message.
  439  */
  440 static int
  441 nglmi_rcvmsg(node_p node, item_p item, hook_p lasthook)
  442 {
  443         sc_p    sc = NG_NODE_PRIVATE(node);
  444         struct ng_mesg *resp = NULL;
  445         int     error = 0;
  446         struct ng_mesg *msg;
  447 
  448         NGI_GET_MSG(item, msg);
  449         switch (msg->header.typecookie) {
  450         case NGM_GENERIC_COOKIE:
  451                 switch (msg->header.cmd) {
  452                 case NGM_TEXT_STATUS:
  453                     {
  454                         char   *arg;
  455                         int     pos, count;
  456 
  457                         NG_MKRESPONSE(resp, msg, NG_TEXTRESPONSE, M_NOWAIT);
  458                         if (resp == NULL) {
  459                                 error = ENOMEM;
  460                                 break;
  461                         }
  462                         arg = resp->data;
  463                         pos = sprintf(arg, "protocol %s ", sc->protoname);
  464                         if (sc->flags & SCF_FIXED)
  465                                 pos += sprintf(arg + pos, "fixed\n");
  466                         else if (sc->flags & SCF_AUTO)
  467                                 pos += sprintf(arg + pos, "auto-detecting\n");
  468                         else
  469                                 pos += sprintf(arg + pos, "auto on dlci %d\n",
  470                                     (sc->lmi_channel == sc->lmi_channel0) ?
  471                                     0 : 1023);
  472                         pos += sprintf(arg + pos,
  473                             "keepalive period: %d seconds\n", sc->liv_rate);
  474                         pos += sprintf(arg + pos,
  475                             "unacknowledged keepalives: %ld\n",
  476                             sc->seq_retries);
  477                         for (count = 0;
  478                              ((count <= MAXDLCI)
  479                               && (pos < (NG_TEXTRESPONSE - 20)));
  480                              count++) {
  481                                 if (sc->dlci_state[count]) {
  482                                         pos += sprintf(arg + pos,
  483                                                "dlci %d %s\n", count,
  484                                                (sc->dlci_state[count]
  485                                         == DLCI_UP) ? "up" : "down");
  486                                 }
  487                         }
  488                         resp->header.arglen = pos + 1;
  489                         break;
  490                     }
  491                 default:
  492                         error = EINVAL;
  493                         break;
  494                 }
  495                 break;
  496         case NGM_LMI_COOKIE:
  497                 switch (msg->header.cmd) {
  498                 case NGM_LMI_GET_STATUS:
  499                     {
  500                         struct nglmistat *stat;
  501                         int k;
  502 
  503                         NG_MKRESPONSE(resp, msg, sizeof(*stat), M_NOWAIT);
  504                         if (!resp) {
  505                                 error = ENOMEM;
  506                                 break;
  507                         }
  508                         stat = (struct nglmistat *) resp->data;
  509                         strncpy(stat->proto,
  510                              sc->protoname, sizeof(stat->proto) - 1);
  511                         strncpy(stat->hook,
  512                               sc->protoname, sizeof(stat->hook) - 1);
  513                         stat->autod = !!(sc->flags & SCF_AUTO);
  514                         stat->fixed = !!(sc->flags & SCF_FIXED);
  515                         for (k = 0; k <= MAXDLCI; k++) {
  516                                 switch (sc->dlci_state[k]) {
  517                                 case DLCI_UP:
  518                                         stat->up[k / 8] |= (1 << (k % 8));
  519                                         /* fall through */
  520                                 case DLCI_DOWN:
  521                                         stat->seen[k / 8] |= (1 << (k % 8));
  522                                         break;
  523                                 }
  524                         }
  525                         break;
  526                     }
  527                 default:
  528                         error = EINVAL;
  529                         break;
  530                 }
  531                 break;
  532         default:
  533                 error = EINVAL;
  534                 break;
  535         }
  536 
  537         NG_RESPOND_MSG(error, node, item, resp);
  538         NG_FREE_MSG(msg);
  539         return (error);
  540 }
  541 
  542 #define STEPBY(stepsize)                        \
  543         do {                                    \
  544                 packetlen -= (stepsize);        \
  545                 data += (stepsize);             \
  546         } while (0)
  547 
  548 /*
  549  * receive data, and use it to update our status.
  550  * Anything coming in on the debug port is discarded.
  551  */
  552 static int
  553 nglmi_rcvdata(hook_p hook, item_p item)
  554 {
  555         sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  556         const   u_char *data;
  557         unsigned short dlci;
  558         u_short packetlen;
  559         int     resptype_seen = 0;
  560         struct mbuf *m;
  561 
  562         NGI_GET_M(item, m);
  563         NG_FREE_ITEM(item);
  564         if (NG_HOOK_PRIVATE(hook) == NULL) {
  565                 goto drop;
  566         }
  567         packetlen = m->m_len;
  568 
  569         /* XXX what if it's more than 1 mbuf? */
  570         if ((packetlen > MHLEN) && !(m->m_flags & M_EXT)) {
  571                 log(LOG_WARNING, "nglmi: packetlen (%d) too big\n", packetlen);
  572                 goto drop;
  573         }
  574         if (m->m_len < packetlen && (m = m_pullup(m, packetlen)) == NULL) {
  575                 log(LOG_WARNING,
  576                     "nglmi: m_pullup failed for %d bytes\n", packetlen);
  577                 return (0);
  578         }
  579         if (nglmi_checkdata(hook, m) == 0)
  580                 return (0);
  581 
  582         /* pass the first 4 bytes (already checked in the nglmi_checkdata()) */
  583         data = mtod(m, const u_char *);
  584         STEPBY(4);
  585 
  586         /* Now check if there is a 'locking shift'. This is only seen in
  587          * Annex D frames. don't bother checking, we already did that. Don't
  588          * increment immediatly as it might not be there. */
  589         if (ANNEXD(sc))
  590                 STEPBY(1);
  591 
  592         /* If we get this far we should consider that it is a legitimate
  593          * frame and we know what it is. */
  594         if (sc->flags & SCF_AUTO) {
  595                 /* note the hook that this valid channel came from and drop
  596                  * out of auto probe mode. */
  597                 if (ANNEXA(sc))
  598                         sc->protoname = NAME_ANNEXA;
  599                 else if (ANNEXD(sc))
  600                         sc->protoname = NAME_ANNEXD;
  601                 else if (GROUP4(sc))
  602                         sc->protoname = NAME_GROUP4;
  603                 else {
  604                         log(LOG_ERR, "nglmi: No known type\n");
  605                         goto drop;
  606                 }
  607                 sc->lmi_channel = hook;
  608                 sc->flags &= ~SCF_AUTO;
  609                 log(LOG_INFO, "nglmi: auto-detected %s LMI on DLCI %d\n",
  610                     sc->protoname, hook == sc->lmi_channel0 ? 0 : 1023);
  611         }
  612 
  613         /* While there is more data in the status packet, keep processing
  614          * status items. First make sure there is enough data for the
  615          * segment descriptor's length field. */
  616         while (packetlen >= 2) {
  617                 u_int   segtype = data[0];
  618                 u_int   segsize = data[1];
  619 
  620                 /* Now that we know how long it claims to be, make sure
  621                  * there is enough data for the next seg. */
  622                 if (packetlen < segsize + 2)
  623                         break;
  624                 switch (segtype) {
  625                 case 0x01:
  626                 case 0x51:
  627                         if (resptype_seen) {
  628                                 log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
  629                                 goto nextIE;
  630                         }
  631                         resptype_seen++;
  632                         /* The remote end tells us what kind of response
  633                          * this is. Only expect a type 0 or 1. if we are a
  634                          * full status, invalidate a few DLCIs just to see
  635                          * that they are still ok. */
  636                         if (segsize != 1)
  637                                 goto nextIE;
  638                         switch (data[2]) {
  639                         case 1:
  640                                 /* partial status, do no extra processing */
  641                                 break;
  642                         case 0:
  643                             {
  644                                 int     count = 0;
  645                                 int     idx = sc->invalidx;
  646 
  647                                 for (count = 0; count < 10; count++) {
  648                                         if (idx > MAXDLCI)
  649                                                 idx = 0;
  650                                         if (sc->dlci_state[idx] == DLCI_UP)
  651                                                 sc->dlci_state[idx] = DLCI_DOWN;
  652                                         idx++;
  653                                 }
  654                                 sc->invalidx = idx;
  655                                 /* we got and we wanted one. relax
  656                                  * now.. but don't reset to 0 if it
  657                                  * was unrequested. */
  658                                 if (sc->livs > sc->liv_per_full)
  659                                         sc->livs = 0;
  660                                 break;
  661                             }
  662                         }
  663                         break;
  664                 case 0x03:
  665                 case 0x53:
  666                         /* The remote tells us what it thinks the sequence
  667                          * numbers are. If it's not size 2, it must be a
  668                          * duplicate to have gotten this far, skip it. */
  669                         if (segsize != 2)
  670                                 goto nextIE;
  671                         sc->remote_seq = data[2];
  672                         if (sc->local_seq == data[3]) {
  673                                 sc->local_seq++;
  674                                 sc->seq_retries = 0;
  675                                 /* Note that all 3 Frame protocols seem to
  676                                  * not like 0 as a sequence number. */
  677                                 if (sc->local_seq == 0)
  678                                         sc->local_seq = 1;
  679                         }
  680                         break;
  681                 case 0x07:
  682                 case 0x57:
  683                         /* The remote tells us about a DLCI that it knows
  684                          * about. There may be many of these in a single
  685                          * status response */
  686                         switch (segsize) {
  687                         case 6:/* only on 'group of 4' */
  688                                 dlci = ((u_short) data[2] & 0xff) << 8;
  689                                 dlci |= (data[3] & 0xff);
  690                                 if ((dlci < 1024) && (dlci > 0)) {
  691                                   /* XXX */
  692                                 }
  693                                 break;
  694                         case 3:
  695                                 dlci = ((u_short) data[2] & 0x3f) << 4;
  696                                 dlci |= ((data[3] & 0x78) >> 3);
  697                                 if ((dlci < 1024) && (dlci > 0)) {
  698                                         /* set up the bottom half of the
  699                                          * support for that dlci if it's not
  700                                          * already been done */
  701                                         /* store this information somewhere */
  702                                 }
  703                                 break;
  704                         default:
  705                                 goto nextIE;
  706                         }
  707                         if (sc->dlci_state[dlci] != DLCI_UP) {
  708                                 /* bring new DLCI to life */
  709                                 /* may do more here some day */
  710                                 if (sc->dlci_state[dlci] != DLCI_DOWN)
  711                                         log(LOG_INFO,
  712                                             "nglmi: DLCI %d became active\n",
  713                                             dlci);
  714                                 sc->dlci_state[dlci] = DLCI_UP;
  715                         }
  716                         break;
  717                 }
  718 nextIE:
  719                 STEPBY(segsize + 2);
  720         }
  721         NG_FREE_M(m);
  722         return (0);
  723 
  724 drop:
  725         NG_FREE_M(m);
  726         return (EINVAL);
  727 }
  728 
  729 /*
  730  * Check that a packet is entirely kosha.
  731  * return 1 of ok, and 0 if not.
  732  * All data is discarded if a 0 is returned.
  733  */
  734 static int
  735 nglmi_checkdata(hook_p hook, struct mbuf *m)
  736 {
  737         sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  738         const   u_char *data;
  739         u_short packetlen;
  740         unsigned short dlci;
  741         u_char  type;
  742         u_char  nextbyte;
  743         int     seq_seen = 0;
  744         int     resptype_seen = 0;      /* 0 , 1 (partial) or 2 (full) */
  745         int     highest_dlci = 0;
  746 
  747         packetlen = m->m_len;
  748         data = mtod(m, const u_char *);
  749         if (*data != 0x03) {
  750                 log(LOG_WARNING, "nglmi: unexpected value in LMI(%d)\n", 1);
  751                 goto reject;
  752         }
  753         STEPBY(1);
  754 
  755         /* look at the protocol ID */
  756         nextbyte = *data;
  757         if (sc->flags & SCF_AUTO) {
  758                 SETLMITYPE(sc, SCF_NOLMI);      /* start with a clean slate */
  759                 switch (nextbyte) {
  760                 case 0x8:
  761                         sc->protoID = 8;
  762                         break;
  763                 case 0x9:
  764                         SETLMITYPE(sc, SCF_GROUP4);
  765                         sc->protoID = 9;
  766                         break;
  767                 default:
  768                         log(LOG_WARNING, "nglmi: bad Protocol ID(%d)\n",
  769                             (int) nextbyte);
  770                         goto reject;
  771                 }
  772         } else {
  773                 if (nextbyte != sc->protoID) {
  774                         log(LOG_WARNING, "nglmi: unexpected Protocol ID(%d)\n",
  775                             (int) nextbyte);
  776                         goto reject;
  777                 }
  778         }
  779         STEPBY(1);
  780 
  781         /* check call reference (always null in non ISDN frame relay) */
  782         if (*data != 0x00) {
  783                 log(LOG_WARNING, "nglmi: unexpected Call Reference (0x%x)\n",
  784                     data[-1]);
  785                 goto reject;
  786         }
  787         STEPBY(1);
  788 
  789         /* check message type */
  790         switch ((type = *data)) {
  791         case 0x75:              /* Status enquiry */
  792                 log(LOG_WARNING, "nglmi: unexpected message type(0x%x)\n",
  793                     data[-1]);
  794                 goto reject;
  795         case 0x7D:              /* Status message */
  796                 break;
  797         default:
  798                 log(LOG_WARNING,
  799                     "nglmi: unexpected msg type(0x%x) \n", (int) type);
  800                 goto reject;
  801         }
  802         STEPBY(1);
  803 
  804         /* Now check if there is a 'locking shift'. This is only seen in
  805          * Annex D frames. Don't increment immediately as it might not be
  806          * there. */
  807         nextbyte = *data;
  808         if (sc->flags & SCF_AUTO) {
  809                 if (!(GROUP4(sc))) {
  810                         if (nextbyte == 0x95) {
  811                                 SETLMITYPE(sc, SCF_ANNEX_D);
  812                                 STEPBY(1);
  813                         } else
  814                                 SETLMITYPE(sc, SCF_ANNEX_A);
  815                 } else if (nextbyte == 0x95) {
  816                         log(LOG_WARNING, "nglmi: locking shift seen in G4\n");
  817                         goto reject;
  818                 }
  819         } else {
  820                 if (ANNEXD(sc)) {
  821                         if (*data == 0x95)
  822                                 STEPBY(1);
  823                         else {
  824                                 log(LOG_WARNING,
  825                                     "nglmi: locking shift missing\n");
  826                                 goto reject;
  827                         }
  828                 } else if (*data == 0x95) {
  829                         log(LOG_WARNING, "nglmi: locking shift seen\n");
  830                         goto reject;
  831                 }
  832         }
  833 
  834         /* While there is more data in the status packet, keep processing
  835          * status items. First make sure there is enough data for the
  836          * segment descriptor's length field. */
  837         while (packetlen >= 2) {
  838                 u_int   segtype = data[0];
  839                 u_int   segsize = data[1];
  840 
  841                 /* Now that we know how long it claims to be, make sure
  842                  * there is enough data for the next seg. */
  843                 if (packetlen < (segsize + 2)) {
  844                         log(LOG_WARNING, "nglmi: IE longer than packet\n");
  845                         break;
  846                 }
  847                 switch (segtype) {
  848                 case 0x01:
  849                 case 0x51:
  850                         /* According to MCI's HP analyser, we should just
  851                          * ignore if there is mor ethan one of these (?). */
  852                         if (resptype_seen) {
  853                                 log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
  854                                 goto nextIE;
  855                         }
  856                         if (segsize != 1) {
  857                                 log(LOG_WARNING, "nglmi: MSGTYPE wrong size\n");
  858                                 goto reject;
  859                         }
  860                         /* The remote end tells us what kind of response
  861                          * this is. Only expect a type 0 or 1. if it was a
  862                          * full (type 0) check we just asked for a type
  863                          * full. */
  864                         switch (data[2]) {
  865                         case 1:/* partial */
  866                                 if (sc->livs > sc->liv_per_full) {
  867                                         log(LOG_WARNING,
  868                                           "nglmi: LIV when FULL expected\n");
  869                                         goto reject;    /* need full */
  870                                 }
  871                                 resptype_seen = 1;
  872                                 break;
  873                         case 0:/* full */
  874                                 /* Full response is always acceptable */
  875                                 resptype_seen = 2;
  876                                 break;
  877                         default:
  878                                 log(LOG_WARNING,
  879                                  "nglmi: Unknown report type %d\n", data[2]);
  880                                 goto reject;
  881                         }
  882                         break;
  883                 case 0x03:
  884                 case 0x53:
  885                         /* The remote tells us what it thinks the sequence
  886                          * numbers are. I would have thought that there
  887                          * needs to be one and only one of these, but MCI
  888                          * want us to just ignore extras. (?) */
  889                         if (resptype_seen == 0) {
  890                                 log(LOG_WARNING, "nglmi: no TYPE before SEQ\n");
  891                                 goto reject;
  892                         }
  893                         if (seq_seen != 0)      /* already seen seq numbers */
  894                                 goto nextIE;
  895                         if (segsize != 2) {
  896                                 log(LOG_WARNING, "nglmi: bad SEQ sts size\n");
  897                                 goto reject;
  898                         }
  899                         if (sc->local_seq != data[3]) {
  900                                 log(LOG_WARNING, "nglmi: unexpected SEQ\n");
  901                                 goto reject;
  902                         }
  903                         seq_seen = 1;
  904                         break;
  905                 case 0x07:
  906                 case 0x57:
  907                         /* The remote tells us about a DLCI that it knows
  908                          * about. There may be many of these in a single
  909                          * status response */
  910                         if (seq_seen != 1) {    /* already seen seq numbers? */
  911                                 log(LOG_WARNING,
  912                                     "nglmi: No sequence before DLCI\n");
  913                                 goto reject;
  914                         }
  915                         if (resptype_seen != 2) {       /* must be full */
  916                                 log(LOG_WARNING,
  917                                     "nglmi: No resp type before DLCI\n");
  918                                 goto reject;
  919                         }
  920                         if (GROUP4(sc)) {
  921                                 if (segsize != 6) {
  922                                         log(LOG_WARNING,
  923                                             "nglmi: wrong IE segsize\n");
  924                                         goto reject;
  925                                 }
  926                                 dlci = ((u_short) data[2] & 0xff) << 8;
  927                                 dlci |= (data[3] & 0xff);
  928                         } else {
  929                                 if (segsize != 3) {
  930                                         log(LOG_WARNING,
  931                                             "nglmi: DLCI headersize of %d"
  932                                             " not supported\n", segsize - 1);
  933                                         goto reject;
  934                                 }
  935                                 dlci = ((u_short) data[2] & 0x3f) << 4;
  936                                 dlci |= ((data[3] & 0x78) >> 3);
  937                         }
  938                         /* async can only have one of these */
  939 #if 0                           /* async not yet accepted */
  940                         if (async && highest_dlci) {
  941                                 log(LOG_WARNING,
  942                                     "nglmi: Async with > 1 DLCI\n");
  943                                 goto reject;
  944                         }
  945 #endif
  946                         /* Annex D says these will always be Ascending, but
  947                          * the HP test for G4 says we should accept
  948                          * duplicates, so for now allow that. ( <= vs. < ) */
  949 #if 0
  950                         /* MCI tests want us to accept out of order for AnxD */
  951                         if ((!GROUP4(sc)) && (dlci < highest_dlci)) {
  952                                 /* duplicate or mis-ordered dlci */
  953                                 /* (spec says they will increase in number) */
  954                                 log(LOG_WARNING, "nglmi: DLCI out of order\n");
  955                                 goto reject;
  956                         }
  957 #endif
  958                         if (dlci > 1023) {
  959                                 log(LOG_WARNING, "nglmi: DLCI out of range\n");
  960                                 goto reject;
  961                         }
  962                         highest_dlci = dlci;
  963                         break;
  964                 default:
  965                         log(LOG_WARNING,
  966                             "nglmi: unknown LMI segment type %d\n", segtype);
  967                 }
  968 nextIE:
  969                 STEPBY(segsize + 2);
  970         }
  971         if (packetlen != 0) {   /* partial junk at end? */
  972                 log(LOG_WARNING,
  973                     "nglmi: %d bytes extra at end of packet\n", packetlen);
  974                 goto print;
  975         }
  976         if (resptype_seen == 0) {
  977                 log(LOG_WARNING, "nglmi: No response type seen\n");
  978                 goto reject;    /* had no response type */
  979         }
  980         if (seq_seen == 0) {
  981                 log(LOG_WARNING, "nglmi: No sequence numbers seen\n");
  982                 goto reject;    /* had no sequence numbers */
  983         }
  984         return (1);
  985 
  986 print:
  987         {
  988                 int     i, j, k, pos;
  989                 char    buf[100];
  990                 int     loc;
  991                 const   u_char *bp = mtod(m, const u_char *);
  992 
  993                 k = i = 0;
  994                 loc = (m->m_len - packetlen);
  995                 log(LOG_WARNING, "nglmi: error at location %d\n", loc);
  996                 while (k < m->m_len) {
  997                         pos = 0;
  998                         j = 0;
  999                         while ((j++ < 16) && k < m->m_len) {
 1000                                 pos += sprintf(buf + pos, "%c%02x",
 1001                                                ((loc == k) ? '>' : ' '),
 1002                                                bp[k]);
 1003                                 k++;
 1004                         }
 1005                         if (i == 0)
 1006                                 log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
 1007                         else
 1008                                 log(LOG_WARNING, "%04d              :%s\n", k, buf);
 1009                         i++;
 1010                 }
 1011         }
 1012         return (1);
 1013 reject:
 1014         {
 1015                 int     i, j, k, pos;
 1016                 char    buf[100];
 1017                 int     loc;
 1018                 const   u_char *bp = mtod(m, const u_char *);
 1019 
 1020                 k = i = 0;
 1021                 loc = (m->m_len - packetlen);
 1022                 log(LOG_WARNING, "nglmi: error at location %d\n", loc);
 1023                 while (k < m->m_len) {
 1024                         pos = 0;
 1025                         j = 0;
 1026                         while ((j++ < 16) && k < m->m_len) {
 1027                                 pos += sprintf(buf + pos, "%c%02x",
 1028                                                ((loc == k) ? '>' : ' '),
 1029                                                bp[k]);
 1030                                 k++;
 1031                         }
 1032                         if (i == 0)
 1033                                 log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
 1034                         else
 1035                                 log(LOG_WARNING, "%04d              :%s\n", k, buf);
 1036                         i++;
 1037                 }
 1038         }
 1039         NG_FREE_M(m);
 1040         return (0);
 1041 }
 1042 
 1043 /*
 1044  * Do local shutdown processing..
 1045  * Cut any remaining links and free our local resources.
 1046  */
 1047 static int
 1048 nglmi_shutdown(node_p node)
 1049 {
 1050         const sc_p sc = NG_NODE_PRIVATE(node);
 1051 
 1052         NG_NODE_SET_PRIVATE(node, NULL);
 1053         NG_NODE_UNREF(sc->node);
 1054         free(sc, M_NETGRAPH);
 1055         return (0);
 1056 }
 1057 
 1058 /*
 1059  * Hook disconnection
 1060  * For this type, removal of any link except "debug" destroys the node.
 1061  */
 1062 static int
 1063 nglmi_disconnect(hook_p hook)
 1064 {
 1065         const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 1066 
 1067         /* OK to remove debug hook(s) */
 1068         if (NG_HOOK_PRIVATE(hook) == NULL)
 1069                 return (0);
 1070 
 1071         /* Stop timer if it's currently active */
 1072         if (sc->flags & SCF_CONNECTED)
 1073                 ng_uncallout(&sc->handle, sc->node);
 1074 
 1075         /* Self-destruct */
 1076         if (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
 1077                 ng_rmnode_self(NG_HOOK_NODE(hook));
 1078         return (0);
 1079 }
 1080 

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