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/7.3/sys/netgraph/ng_lmi.c 154357 2006-01-14 14:17:27Z 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         MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_NOWAIT | M_ZERO);
  189         if (sc == NULL)
  190                 return (ENOMEM);
  191 
  192         NG_NODE_SET_PRIVATE(node, sc);
  193         sc->node = node;
  194 
  195         ng_callout_init(&sc->handle);
  196         sc->protoname = NAME_NONE;
  197         sc->liv_per_full = NG_LMI_SEQ_PER_FULL; /* make this dynamic */
  198         sc->liv_rate = NG_LMI_KEEPALIVE_RATE;
  199         return (0);
  200 }
  201 
  202 /*
  203  * The LMI channel has a private pointer which is the same as the
  204  * node private pointer. The debug channel has a NULL private pointer.
  205  */
  206 static int
  207 nglmi_newhook(node_p node, hook_p hook, const char *name)
  208 {
  209         sc_p sc = NG_NODE_PRIVATE(node);
  210 
  211         if (strcmp(name, NG_LMI_HOOK_DEBUG) == 0) {
  212                 NG_HOOK_SET_PRIVATE(hook, NULL);
  213                 return (0);
  214         }
  215         if (sc->flags & SCF_CONNECTED) {
  216                 /* already connected, return an error */
  217                 return (EINVAL);
  218         }
  219         if (strcmp(name, NG_LMI_HOOK_ANNEXA) == 0) {
  220                 sc->lmi_annexA = hook;
  221                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  222                 sc->protoID = 8;
  223                 SETLMITYPE(sc, SCF_ANNEX_A);
  224                 sc->protoname = NAME_ANNEXA;
  225                 nglmi_startup_fixed(sc, hook);
  226         } else if (strcmp(name, NG_LMI_HOOK_ANNEXD) == 0) {
  227                 sc->lmi_annexD = hook;
  228                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  229                 sc->protoID = 8;
  230                 SETLMITYPE(sc, SCF_ANNEX_D);
  231                 sc->protoname = NAME_ANNEXD;
  232                 nglmi_startup_fixed(sc, hook);
  233         } else if (strcmp(name, NG_LMI_HOOK_GROUPOF4) == 0) {
  234                 sc->lmi_group4 = hook;
  235                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  236                 sc->protoID = 9;
  237                 SETLMITYPE(sc, SCF_GROUP4);
  238                 sc->protoname = NAME_GROUP4;
  239                 nglmi_startup_fixed(sc, hook);
  240         } else if (strcmp(name, NG_LMI_HOOK_AUTO0) == 0) {
  241                 /* Note this, and if B is already installed, we're complete */
  242                 sc->lmi_channel0 = hook;
  243                 sc->protoname = NAME_NONE;
  244                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  245                 if (sc->lmi_channel1023)
  246                         nglmi_startup_auto(sc);
  247         } else if (strcmp(name, NG_LMI_HOOK_AUTO1023) == 0) {
  248                 /* Note this, and if A is already installed, we're complete */
  249                 sc->lmi_channel1023 = hook;
  250                 sc->protoname = NAME_NONE;
  251                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  252                 if (sc->lmi_channel0)
  253                         nglmi_startup_auto(sc);
  254         } else
  255                 return (EINVAL);                /* unknown hook */
  256         return (0);
  257 }
  258 
  259 /*
  260  * We have just attached to a live (we hope) node.
  261  * Fire out a LMI inquiry, and then start up the timers.
  262  */
  263 static void
  264 LMI_ticker(node_p node, hook_p hook, void *arg1, int arg2)
  265 {
  266         sc_p sc = NG_NODE_PRIVATE(node);
  267 
  268         if (sc->flags & SCF_AUTO) {
  269                 ngauto_state_machine(sc);
  270                 ng_callout(&sc->handle, node, NULL, NG_LMI_POLL_RATE * hz,
  271                     LMI_ticker, NULL, 0);
  272         } else {
  273                 if (sc->livs++ >= sc->liv_per_full) {
  274                         nglmi_inquire(sc, 1);
  275                         /* sc->livs = 0; *//* do this when we get the answer! */
  276                 } else {
  277                         nglmi_inquire(sc, 0);
  278                 }
  279                 ng_callout(&sc->handle, node, NULL, sc->liv_rate * hz,
  280                     LMI_ticker, NULL, 0);
  281         }
  282 }
  283 
  284 static void
  285 nglmi_startup_fixed(sc_p sc, hook_p hook)
  286 {
  287         sc->flags |= (SCF_FIXED | SCF_CONNECTED);
  288         sc->lmi_channel = hook;
  289         nglmi_startup(sc);
  290 }
  291 
  292 static void
  293 nglmi_startup_auto(sc_p sc)
  294 {
  295         sc->flags |= (SCF_AUTO | SCF_CONNECTED);
  296         sc->poll_state = 0;     /* reset state machine */
  297         sc->poll_count = 0;
  298         nglmi_startup(sc);
  299 }
  300 
  301 static void
  302 nglmi_startup(sc_p sc)
  303 {
  304         sc->remote_seq = 0;
  305         sc->local_seq = 1;
  306         sc->seq_retries = 0;
  307         sc->livs = sc->liv_per_full - 1;
  308         /* start off the ticker in 1 sec */
  309         ng_callout(&sc->handle, sc->node, NULL, hz, LMI_ticker, NULL, 0);
  310 }
  311 
  312 static void
  313 nglmi_inquire(sc_p sc, int full)
  314 {
  315         struct mbuf *m;
  316         struct ng_tag_prio *ptag;
  317         char   *cptr, *start;
  318         int     error;
  319 
  320         if (sc->lmi_channel == NULL)
  321                 return;
  322         MGETHDR(m, M_DONTWAIT, MT_DATA);
  323         if (m == NULL) {
  324                 log(LOG_ERR, "nglmi: unable to start up LMI processing\n");
  325                 return;
  326         }
  327         m->m_pkthdr.rcvif = NULL;
  328 
  329         /* Attach a tag to packet, marking it of link level state priority, so
  330          * that device driver would put it in the beginning of queue */
  331 
  332         ptag = (struct ng_tag_prio *)m_tag_alloc(NGM_GENERIC_COOKIE, NG_TAG_PRIO,
  333             (sizeof(struct ng_tag_prio) - sizeof(struct m_tag)), M_NOWAIT);
  334         if (ptag != NULL) {     /* if it failed, well, it was optional anyhow */
  335                 ptag->priority = NG_PRIO_LINKSTATE;
  336                 ptag->discardability = -1;
  337                 m_tag_prepend(m, &ptag->tag);
  338         }
  339 
  340         m->m_data += 4;         /* leave some room for a header */
  341         cptr = start = mtod(m, char *);
  342         /* add in the header for an LMI inquiry. */
  343         *cptr++ = 0x03;         /* UI frame */
  344         if (GROUP4(sc))
  345                 *cptr++ = 0x09; /* proto discriminator */
  346         else
  347                 *cptr++ = 0x08; /* proto discriminator */
  348         *cptr++ = 0x00;         /* call reference */
  349         *cptr++ = 0x75;         /* inquiry */
  350 
  351         /* If we are Annex-D, add locking shift to codeset 5. */
  352         if (ANNEXD(sc))
  353                 *cptr++ = 0x95; /* locking shift */
  354         /* Add a request type */
  355         if (ANNEXA(sc))
  356                 *cptr++ = 0x51; /* report type */
  357         else
  358                 *cptr++ = 0x01; /* report type */
  359         *cptr++ = 0x01;         /* size = 1 */
  360         if (full)
  361                 *cptr++ = 0x00; /* full */
  362         else
  363                 *cptr++ = 0x01; /* partial */
  364 
  365         /* Add a link verification IE */
  366         if (ANNEXA(sc))
  367                 *cptr++ = 0x53; /* verification IE */
  368         else
  369                 *cptr++ = 0x03; /* verification IE */
  370         *cptr++ = 0x02;         /* 2 extra bytes */
  371         *cptr++ = sc->local_seq;
  372         *cptr++ = sc->remote_seq;
  373         sc->seq_retries++;
  374 
  375         /* Send it */
  376         m->m_len = m->m_pkthdr.len = cptr - start;
  377         NG_SEND_DATA_ONLY(error, sc->lmi_channel, m);
  378 
  379         /* If we've been sending requests for long enough, and there has
  380          * been no response, then mark as DOWN, any DLCIs that are UP. */
  381         if (sc->seq_retries == LMI_PATIENCE) {
  382                 int     count;
  383 
  384                 for (count = 0; count < MAXDLCI; count++)
  385                         if (sc->dlci_state[count] == DLCI_UP)
  386                                 sc->dlci_state[count] = DLCI_DOWN;
  387         }
  388 }
  389 
  390 /*
  391  * State machine for LMI auto-detect. The transitions are ordered
  392  * to try the more likely possibilities first.
  393  */
  394 static void
  395 ngauto_state_machine(sc_p sc)
  396 {
  397         if ((sc->poll_count <= 0) || (sc->poll_count > LMIPOLLSIZE)) {
  398                 /* time to change states in the auto probe machine */
  399                 /* capture wild values of poll_count while we are at it */
  400                 sc->poll_count = LMIPOLLSIZE;
  401                 sc->poll_state++;
  402         }
  403         switch (sc->poll_state) {
  404         case 7:
  405                 log(LOG_WARNING, "nglmi: no response from exchange\n");
  406         default:                /* capture bad states */
  407                 sc->poll_state = 1;
  408         case 1:
  409                 sc->lmi_channel = sc->lmi_channel0;
  410                 SETLMITYPE(sc, SCF_ANNEX_D);
  411                 break;
  412         case 2:
  413                 sc->lmi_channel = sc->lmi_channel1023;
  414                 SETLMITYPE(sc, SCF_ANNEX_D);
  415                 break;
  416         case 3:
  417                 sc->lmi_channel = sc->lmi_channel0;
  418                 SETLMITYPE(sc, SCF_ANNEX_A);
  419                 break;
  420         case 4:
  421                 sc->lmi_channel = sc->lmi_channel1023;
  422                 SETLMITYPE(sc, SCF_GROUP4);
  423                 break;
  424         case 5:
  425                 sc->lmi_channel = sc->lmi_channel1023;
  426                 SETLMITYPE(sc, SCF_ANNEX_A);
  427                 break;
  428         case 6:
  429                 sc->lmi_channel = sc->lmi_channel0;
  430                 SETLMITYPE(sc, SCF_GROUP4);
  431                 break;
  432         }
  433 
  434         /* send an inquirey encoded appropriatly */
  435         nglmi_inquire(sc, 0);
  436         sc->poll_count--;
  437 }
  438 
  439 /*
  440  * Receive a netgraph control message.
  441  */
  442 static int
  443 nglmi_rcvmsg(node_p node, item_p item, hook_p lasthook)
  444 {
  445         sc_p    sc = NG_NODE_PRIVATE(node);
  446         struct ng_mesg *resp = NULL;
  447         int     error = 0;
  448         struct ng_mesg *msg;
  449 
  450         NGI_GET_MSG(item, msg);
  451         switch (msg->header.typecookie) {
  452         case NGM_GENERIC_COOKIE:
  453                 switch (msg->header.cmd) {
  454                 case NGM_TEXT_STATUS:
  455                     {
  456                         char   *arg;
  457                         int     pos, count;
  458 
  459                         NG_MKRESPONSE(resp, msg, NG_TEXTRESPONSE, M_NOWAIT);
  460                         if (resp == NULL) {
  461                                 error = ENOMEM;
  462                                 break;
  463                         }
  464                         arg = resp->data;
  465                         pos = sprintf(arg, "protocol %s ", sc->protoname);
  466                         if (sc->flags & SCF_FIXED)
  467                                 pos += sprintf(arg + pos, "fixed\n");
  468                         else if (sc->flags & SCF_AUTO)
  469                                 pos += sprintf(arg + pos, "auto-detecting\n");
  470                         else
  471                                 pos += sprintf(arg + pos, "auto on dlci %d\n",
  472                                     (sc->lmi_channel == sc->lmi_channel0) ?
  473                                     0 : 1023);
  474                         pos += sprintf(arg + pos,
  475                             "keepalive period: %d seconds\n", sc->liv_rate);
  476                         pos += sprintf(arg + pos,
  477                             "unacknowledged keepalives: %ld\n",
  478                             sc->seq_retries);
  479                         for (count = 0;
  480                              ((count <= MAXDLCI)
  481                               && (pos < (NG_TEXTRESPONSE - 20)));
  482                              count++) {
  483                                 if (sc->dlci_state[count]) {
  484                                         pos += sprintf(arg + pos,
  485                                                "dlci %d %s\n", count,
  486                                                (sc->dlci_state[count]
  487                                         == DLCI_UP) ? "up" : "down");
  488                                 }
  489                         }
  490                         resp->header.arglen = pos + 1;
  491                         break;
  492                     }
  493                 default:
  494                         error = EINVAL;
  495                         break;
  496                 }
  497                 break;
  498         case NGM_LMI_COOKIE:
  499                 switch (msg->header.cmd) {
  500                 case NGM_LMI_GET_STATUS:
  501                     {
  502                         struct nglmistat *stat;
  503                         int k;
  504 
  505                         NG_MKRESPONSE(resp, msg, sizeof(*stat), M_NOWAIT);
  506                         if (!resp) {
  507                                 error = ENOMEM;
  508                                 break;
  509                         }
  510                         stat = (struct nglmistat *) resp->data;
  511                         strncpy(stat->proto,
  512                              sc->protoname, sizeof(stat->proto) - 1);
  513                         strncpy(stat->hook,
  514                               sc->protoname, sizeof(stat->hook) - 1);
  515                         stat->autod = !!(sc->flags & SCF_AUTO);
  516                         stat->fixed = !!(sc->flags & SCF_FIXED);
  517                         for (k = 0; k <= MAXDLCI; k++) {
  518                                 switch (sc->dlci_state[k]) {
  519                                 case DLCI_UP:
  520                                         stat->up[k / 8] |= (1 << (k % 8));
  521                                         /* fall through */
  522                                 case DLCI_DOWN:
  523                                         stat->seen[k / 8] |= (1 << (k % 8));
  524                                         break;
  525                                 }
  526                         }
  527                         break;
  528                     }
  529                 default:
  530                         error = EINVAL;
  531                         break;
  532                 }
  533                 break;
  534         default:
  535                 error = EINVAL;
  536                 break;
  537         }
  538 
  539         NG_RESPOND_MSG(error, node, item, resp);
  540         NG_FREE_MSG(msg);
  541         return (error);
  542 }
  543 
  544 #define STEPBY(stepsize)                        \
  545         do {                                    \
  546                 packetlen -= (stepsize);        \
  547                 data += (stepsize);             \
  548         } while (0)
  549 
  550 /*
  551  * receive data, and use it to update our status.
  552  * Anything coming in on the debug port is discarded.
  553  */
  554 static int
  555 nglmi_rcvdata(hook_p hook, item_p item)
  556 {
  557         sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  558         const   u_char *data;
  559         unsigned short dlci;
  560         u_short packetlen;
  561         int     resptype_seen = 0;
  562         struct mbuf *m;
  563 
  564         NGI_GET_M(item, m);
  565         NG_FREE_ITEM(item);
  566         if (NG_HOOK_PRIVATE(hook) == NULL) {
  567                 goto drop;
  568         }
  569         packetlen = m->m_len;
  570 
  571         /* XXX what if it's more than 1 mbuf? */
  572         if ((packetlen > MHLEN) && !(m->m_flags & M_EXT)) {
  573                 log(LOG_WARNING, "nglmi: packetlen (%d) too big\n", packetlen);
  574                 goto drop;
  575         }
  576         if (m->m_len < packetlen && (m = m_pullup(m, packetlen)) == NULL) {
  577                 log(LOG_WARNING,
  578                     "nglmi: m_pullup failed for %d bytes\n", packetlen);
  579                 return (0);
  580         }
  581         if (nglmi_checkdata(hook, m) == 0)
  582                 return (0);
  583 
  584         /* pass the first 4 bytes (already checked in the nglmi_checkdata()) */
  585         data = mtod(m, const u_char *);
  586         STEPBY(4);
  587 
  588         /* Now check if there is a 'locking shift'. This is only seen in
  589          * Annex D frames. don't bother checking, we already did that. Don't
  590          * increment immediatly as it might not be there. */
  591         if (ANNEXD(sc))
  592                 STEPBY(1);
  593 
  594         /* If we get this far we should consider that it is a legitimate
  595          * frame and we know what it is. */
  596         if (sc->flags & SCF_AUTO) {
  597                 /* note the hook that this valid channel came from and drop
  598                  * out of auto probe mode. */
  599                 if (ANNEXA(sc))
  600                         sc->protoname = NAME_ANNEXA;
  601                 else if (ANNEXD(sc))
  602                         sc->protoname = NAME_ANNEXD;
  603                 else if (GROUP4(sc))
  604                         sc->protoname = NAME_GROUP4;
  605                 else {
  606                         log(LOG_ERR, "nglmi: No known type\n");
  607                         goto drop;
  608                 }
  609                 sc->lmi_channel = hook;
  610                 sc->flags &= ~SCF_AUTO;
  611                 log(LOG_INFO, "nglmi: auto-detected %s LMI on DLCI %d\n",
  612                     sc->protoname, hook == sc->lmi_channel0 ? 0 : 1023);
  613         }
  614 
  615         /* While there is more data in the status packet, keep processing
  616          * status items. First make sure there is enough data for the
  617          * segment descriptor's length field. */
  618         while (packetlen >= 2) {
  619                 u_int   segtype = data[0];
  620                 u_int   segsize = data[1];
  621 
  622                 /* Now that we know how long it claims to be, make sure
  623                  * there is enough data for the next seg. */
  624                 if (packetlen < segsize + 2)
  625                         break;
  626                 switch (segtype) {
  627                 case 0x01:
  628                 case 0x51:
  629                         if (resptype_seen) {
  630                                 log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
  631                                 goto nextIE;
  632                         }
  633                         resptype_seen++;
  634                         /* The remote end tells us what kind of response
  635                          * this is. Only expect a type 0 or 1. if we are a
  636                          * full status, invalidate a few DLCIs just to see
  637                          * that they are still ok. */
  638                         if (segsize != 1)
  639                                 goto nextIE;
  640                         switch (data[2]) {
  641                         case 1:
  642                                 /* partial status, do no extra processing */
  643                                 break;
  644                         case 0:
  645                             {
  646                                 int     count = 0;
  647                                 int     idx = sc->invalidx;
  648 
  649                                 for (count = 0; count < 10; count++) {
  650                                         if (idx > MAXDLCI)
  651                                                 idx = 0;
  652                                         if (sc->dlci_state[idx] == DLCI_UP)
  653                                                 sc->dlci_state[idx] = DLCI_DOWN;
  654                                         idx++;
  655                                 }
  656                                 sc->invalidx = idx;
  657                                 /* we got and we wanted one. relax
  658                                  * now.. but don't reset to 0 if it
  659                                  * was unrequested. */
  660                                 if (sc->livs > sc->liv_per_full)
  661                                         sc->livs = 0;
  662                                 break;
  663                             }
  664                         }
  665                         break;
  666                 case 0x03:
  667                 case 0x53:
  668                         /* The remote tells us what it thinks the sequence
  669                          * numbers are. If it's not size 2, it must be a
  670                          * duplicate to have gotten this far, skip it. */
  671                         if (segsize != 2)
  672                                 goto nextIE;
  673                         sc->remote_seq = data[2];
  674                         if (sc->local_seq == data[3]) {
  675                                 sc->local_seq++;
  676                                 sc->seq_retries = 0;
  677                                 /* Note that all 3 Frame protocols seem to
  678                                  * not like 0 as a sequence number. */
  679                                 if (sc->local_seq == 0)
  680                                         sc->local_seq = 1;
  681                         }
  682                         break;
  683                 case 0x07:
  684                 case 0x57:
  685                         /* The remote tells us about a DLCI that it knows
  686                          * about. There may be many of these in a single
  687                          * status response */
  688                         switch (segsize) {
  689                         case 6:/* only on 'group of 4' */
  690                                 dlci = ((u_short) data[2] & 0xff) << 8;
  691                                 dlci |= (data[3] & 0xff);
  692                                 if ((dlci < 1024) && (dlci > 0)) {
  693                                   /* XXX */
  694                                 }
  695                                 break;
  696                         case 3:
  697                                 dlci = ((u_short) data[2] & 0x3f) << 4;
  698                                 dlci |= ((data[3] & 0x78) >> 3);
  699                                 if ((dlci < 1024) && (dlci > 0)) {
  700                                         /* set up the bottom half of the
  701                                          * support for that dlci if it's not
  702                                          * already been done */
  703                                         /* store this information somewhere */
  704                                 }
  705                                 break;
  706                         default:
  707                                 goto nextIE;
  708                         }
  709                         if (sc->dlci_state[dlci] != DLCI_UP) {
  710                                 /* bring new DLCI to life */
  711                                 /* may do more here some day */
  712                                 if (sc->dlci_state[dlci] != DLCI_DOWN)
  713                                         log(LOG_INFO,
  714                                             "nglmi: DLCI %d became active\n",
  715                                             dlci);
  716                                 sc->dlci_state[dlci] = DLCI_UP;
  717                         }
  718                         break;
  719                 }
  720 nextIE:
  721                 STEPBY(segsize + 2);
  722         }
  723         NG_FREE_M(m);
  724         return (0);
  725 
  726 drop:
  727         NG_FREE_M(m);
  728         return (EINVAL);
  729 }
  730 
  731 /*
  732  * Check that a packet is entirely kosha.
  733  * return 1 of ok, and 0 if not.
  734  * All data is discarded if a 0 is returned.
  735  */
  736 static int
  737 nglmi_checkdata(hook_p hook, struct mbuf *m)
  738 {
  739         sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  740         const   u_char *data;
  741         u_short packetlen;
  742         unsigned short dlci;
  743         u_char  type;
  744         u_char  nextbyte;
  745         int     seq_seen = 0;
  746         int     resptype_seen = 0;      /* 0 , 1 (partial) or 2 (full) */
  747         int     highest_dlci = 0;
  748 
  749         packetlen = m->m_len;
  750         data = mtod(m, const u_char *);
  751         if (*data != 0x03) {
  752                 log(LOG_WARNING, "nglmi: unexpected value in LMI(%d)\n", 1);
  753                 goto reject;
  754         }
  755         STEPBY(1);
  756 
  757         /* look at the protocol ID */
  758         nextbyte = *data;
  759         if (sc->flags & SCF_AUTO) {
  760                 SETLMITYPE(sc, SCF_NOLMI);      /* start with a clean slate */
  761                 switch (nextbyte) {
  762                 case 0x8:
  763                         sc->protoID = 8;
  764                         break;
  765                 case 0x9:
  766                         SETLMITYPE(sc, SCF_GROUP4);
  767                         sc->protoID = 9;
  768                         break;
  769                 default:
  770                         log(LOG_WARNING, "nglmi: bad Protocol ID(%d)\n",
  771                             (int) nextbyte);
  772                         goto reject;
  773                 }
  774         } else {
  775                 if (nextbyte != sc->protoID) {
  776                         log(LOG_WARNING, "nglmi: unexpected Protocol ID(%d)\n",
  777                             (int) nextbyte);
  778                         goto reject;
  779                 }
  780         }
  781         STEPBY(1);
  782 
  783         /* check call reference (always null in non ISDN frame relay) */
  784         if (*data != 0x00) {
  785                 log(LOG_WARNING, "nglmi: unexpected Call Reference (0x%x)\n",
  786                     data[-1]);
  787                 goto reject;
  788         }
  789         STEPBY(1);
  790 
  791         /* check message type */
  792         switch ((type = *data)) {
  793         case 0x75:              /* Status enquiry */
  794                 log(LOG_WARNING, "nglmi: unexpected message type(0x%x)\n",
  795                     data[-1]);
  796                 goto reject;
  797         case 0x7D:              /* Status message */
  798                 break;
  799         default:
  800                 log(LOG_WARNING,
  801                     "nglmi: unexpected msg type(0x%x) \n", (int) type);
  802                 goto reject;
  803         }
  804         STEPBY(1);
  805 
  806         /* Now check if there is a 'locking shift'. This is only seen in
  807          * Annex D frames. Don't increment immediately as it might not be
  808          * there. */
  809         nextbyte = *data;
  810         if (sc->flags & SCF_AUTO) {
  811                 if (!(GROUP4(sc))) {
  812                         if (nextbyte == 0x95) {
  813                                 SETLMITYPE(sc, SCF_ANNEX_D);
  814                                 STEPBY(1);
  815                         } else
  816                                 SETLMITYPE(sc, SCF_ANNEX_A);
  817                 } else if (nextbyte == 0x95) {
  818                         log(LOG_WARNING, "nglmi: locking shift seen in G4\n");
  819                         goto reject;
  820                 }
  821         } else {
  822                 if (ANNEXD(sc)) {
  823                         if (*data == 0x95)
  824                                 STEPBY(1);
  825                         else {
  826                                 log(LOG_WARNING,
  827                                     "nglmi: locking shift missing\n");
  828                                 goto reject;
  829                         }
  830                 } else if (*data == 0x95) {
  831                         log(LOG_WARNING, "nglmi: locking shift seen\n");
  832                         goto reject;
  833                 }
  834         }
  835 
  836         /* While there is more data in the status packet, keep processing
  837          * status items. First make sure there is enough data for the
  838          * segment descriptor's length field. */
  839         while (packetlen >= 2) {
  840                 u_int   segtype = data[0];
  841                 u_int   segsize = data[1];
  842 
  843                 /* Now that we know how long it claims to be, make sure
  844                  * there is enough data for the next seg. */
  845                 if (packetlen < (segsize + 2)) {
  846                         log(LOG_WARNING, "nglmi: IE longer than packet\n");
  847                         break;
  848                 }
  849                 switch (segtype) {
  850                 case 0x01:
  851                 case 0x51:
  852                         /* According to MCI's HP analyser, we should just
  853                          * ignore if there is mor ethan one of these (?). */
  854                         if (resptype_seen) {
  855                                 log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
  856                                 goto nextIE;
  857                         }
  858                         if (segsize != 1) {
  859                                 log(LOG_WARNING, "nglmi: MSGTYPE wrong size\n");
  860                                 goto reject;
  861                         }
  862                         /* The remote end tells us what kind of response
  863                          * this is. Only expect a type 0 or 1. if it was a
  864                          * full (type 0) check we just asked for a type
  865                          * full. */
  866                         switch (data[2]) {
  867                         case 1:/* partial */
  868                                 if (sc->livs > sc->liv_per_full) {
  869                                         log(LOG_WARNING,
  870                                           "nglmi: LIV when FULL expected\n");
  871                                         goto reject;    /* need full */
  872                                 }
  873                                 resptype_seen = 1;
  874                                 break;
  875                         case 0:/* full */
  876                                 /* Full response is always acceptable */
  877                                 resptype_seen = 2;
  878                                 break;
  879                         default:
  880                                 log(LOG_WARNING,
  881                                  "nglmi: Unknown report type %d\n", data[2]);
  882                                 goto reject;
  883                         }
  884                         break;
  885                 case 0x03:
  886                 case 0x53:
  887                         /* The remote tells us what it thinks the sequence
  888                          * numbers are. I would have thought that there
  889                          * needs to be one and only one of these, but MCI
  890                          * want us to just ignore extras. (?) */
  891                         if (resptype_seen == 0) {
  892                                 log(LOG_WARNING, "nglmi: no TYPE before SEQ\n");
  893                                 goto reject;
  894                         }
  895                         if (seq_seen != 0)      /* already seen seq numbers */
  896                                 goto nextIE;
  897                         if (segsize != 2) {
  898                                 log(LOG_WARNING, "nglmi: bad SEQ sts size\n");
  899                                 goto reject;
  900                         }
  901                         if (sc->local_seq != data[3]) {
  902                                 log(LOG_WARNING, "nglmi: unexpected SEQ\n");
  903                                 goto reject;
  904                         }
  905                         seq_seen = 1;
  906                         break;
  907                 case 0x07:
  908                 case 0x57:
  909                         /* The remote tells us about a DLCI that it knows
  910                          * about. There may be many of these in a single
  911                          * status response */
  912                         if (seq_seen != 1) {    /* already seen seq numbers? */
  913                                 log(LOG_WARNING,
  914                                     "nglmi: No sequence before DLCI\n");
  915                                 goto reject;
  916                         }
  917                         if (resptype_seen != 2) {       /* must be full */
  918                                 log(LOG_WARNING,
  919                                     "nglmi: No resp type before DLCI\n");
  920                                 goto reject;
  921                         }
  922                         if (GROUP4(sc)) {
  923                                 if (segsize != 6) {
  924                                         log(LOG_WARNING,
  925                                             "nglmi: wrong IE segsize\n");
  926                                         goto reject;
  927                                 }
  928                                 dlci = ((u_short) data[2] & 0xff) << 8;
  929                                 dlci |= (data[3] & 0xff);
  930                         } else {
  931                                 if (segsize != 3) {
  932                                         log(LOG_WARNING,
  933                                             "nglmi: DLCI headersize of %d"
  934                                             " not supported\n", segsize - 1);
  935                                         goto reject;
  936                                 }
  937                                 dlci = ((u_short) data[2] & 0x3f) << 4;
  938                                 dlci |= ((data[3] & 0x78) >> 3);
  939                         }
  940                         /* async can only have one of these */
  941 #if 0                           /* async not yet accepted */
  942                         if (async && highest_dlci) {
  943                                 log(LOG_WARNING,
  944                                     "nglmi: Async with > 1 DLCI\n");
  945                                 goto reject;
  946                         }
  947 #endif
  948                         /* Annex D says these will always be Ascending, but
  949                          * the HP test for G4 says we should accept
  950                          * duplicates, so for now allow that. ( <= vs. < ) */
  951 #if 0
  952                         /* MCI tests want us to accept out of order for AnxD */
  953                         if ((!GROUP4(sc)) && (dlci < highest_dlci)) {
  954                                 /* duplicate or mis-ordered dlci */
  955                                 /* (spec says they will increase in number) */
  956                                 log(LOG_WARNING, "nglmi: DLCI out of order\n");
  957                                 goto reject;
  958                         }
  959 #endif
  960                         if (dlci > 1023) {
  961                                 log(LOG_WARNING, "nglmi: DLCI out of range\n");
  962                                 goto reject;
  963                         }
  964                         highest_dlci = dlci;
  965                         break;
  966                 default:
  967                         log(LOG_WARNING,
  968                             "nglmi: unknown LMI segment type %d\n", segtype);
  969                 }
  970 nextIE:
  971                 STEPBY(segsize + 2);
  972         }
  973         if (packetlen != 0) {   /* partial junk at end? */
  974                 log(LOG_WARNING,
  975                     "nglmi: %d bytes extra at end of packet\n", packetlen);
  976                 goto print;
  977         }
  978         if (resptype_seen == 0) {
  979                 log(LOG_WARNING, "nglmi: No response type seen\n");
  980                 goto reject;    /* had no response type */
  981         }
  982         if (seq_seen == 0) {
  983                 log(LOG_WARNING, "nglmi: No sequence numbers seen\n");
  984                 goto reject;    /* had no sequence numbers */
  985         }
  986         return (1);
  987 
  988 print:
  989         {
  990                 int     i, j, k, pos;
  991                 char    buf[100];
  992                 int     loc;
  993                 const   u_char *bp = mtod(m, const u_char *);
  994 
  995                 k = i = 0;
  996                 loc = (m->m_len - packetlen);
  997                 log(LOG_WARNING, "nglmi: error at location %d\n", loc);
  998                 while (k < m->m_len) {
  999                         pos = 0;
 1000                         j = 0;
 1001                         while ((j++ < 16) && k < m->m_len) {
 1002                                 pos += sprintf(buf + pos, "%c%02x",
 1003                                                ((loc == k) ? '>' : ' '),
 1004                                                bp[k]);
 1005                                 k++;
 1006                         }
 1007                         if (i == 0)
 1008                                 log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
 1009                         else
 1010                                 log(LOG_WARNING, "%04d              :%s\n", k, buf);
 1011                         i++;
 1012                 }
 1013         }
 1014         return (1);
 1015 reject:
 1016         {
 1017                 int     i, j, k, pos;
 1018                 char    buf[100];
 1019                 int     loc;
 1020                 const   u_char *bp = mtod(m, const u_char *);
 1021 
 1022                 k = i = 0;
 1023                 loc = (m->m_len - packetlen);
 1024                 log(LOG_WARNING, "nglmi: error at location %d\n", loc);
 1025                 while (k < m->m_len) {
 1026                         pos = 0;
 1027                         j = 0;
 1028                         while ((j++ < 16) && k < m->m_len) {
 1029                                 pos += sprintf(buf + pos, "%c%02x",
 1030                                                ((loc == k) ? '>' : ' '),
 1031                                                bp[k]);
 1032                                 k++;
 1033                         }
 1034                         if (i == 0)
 1035                                 log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
 1036                         else
 1037                                 log(LOG_WARNING, "%04d              :%s\n", k, buf);
 1038                         i++;
 1039                 }
 1040         }
 1041         NG_FREE_M(m);
 1042         return (0);
 1043 }
 1044 
 1045 /*
 1046  * Do local shutdown processing..
 1047  * Cut any remaining links and free our local resources.
 1048  */
 1049 static int
 1050 nglmi_shutdown(node_p node)
 1051 {
 1052         const sc_p sc = NG_NODE_PRIVATE(node);
 1053 
 1054         NG_NODE_SET_PRIVATE(node, NULL);
 1055         NG_NODE_UNREF(sc->node);
 1056         FREE(sc, M_NETGRAPH);
 1057         return (0);
 1058 }
 1059 
 1060 /*
 1061  * Hook disconnection
 1062  * For this type, removal of any link except "debug" destroys the node.
 1063  */
 1064 static int
 1065 nglmi_disconnect(hook_p hook)
 1066 {
 1067         const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 1068 
 1069         /* OK to remove debug hook(s) */
 1070         if (NG_HOOK_PRIVATE(hook) == NULL)
 1071                 return (0);
 1072 
 1073         /* Stop timer if it's currently active */
 1074         if (sc->flags & SCF_CONNECTED)
 1075                 ng_uncallout(&sc->handle, sc->node);
 1076 
 1077         /* Self-destruct */
 1078         if (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
 1079                 ng_rmnode_self(NG_HOOK_NODE(hook));
 1080         return (0);
 1081 }
 1082 

Cache object: 65871df7c2359accd4a0ec2e8cf74c39


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