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 /*
    3  * ng_lmi.c
    4  *
    5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
    6  * All rights reserved.
    7  * 
    8  * Subject to the following obligations and disclaimer of warranty, use and
    9  * redistribution of this software, in source or object code forms, with or
   10  * without modifications are expressly permitted by Whistle Communications;
   11  * provided, however, that:
   12  * 1. Any and all reproductions of the source or object code must include the
   13  *    copyright notice above and the following disclaimer of warranties; and
   14  * 2. No rights are granted, in any manner or form, to use Whistle
   15  *    Communications, Inc. trademarks, including the mark "WHISTLE
   16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
   17  *    such appears in the above copyright notice or in the software.
   18  * 
   19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
   20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
   21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
   22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
   23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
   24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
   25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
   26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
   27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
   28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
   29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
   30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
   31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
   32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
   35  * OF SUCH DAMAGE.
   36  *
   37  * Author: Julian Elischer <julian@freebsd.org>
   38  *
   39  * $FreeBSD: releng/5.2/sys/netgraph/ng_lmi.c 111119 2003-02-19 05:47:46Z imp $
   40  * $Whistle: ng_lmi.c,v 1.38 1999/11/01 09:24:52 julian Exp $
   41  */
   42 
   43 /*
   44  * This node performs the frame relay LMI protocol. It knows how
   45  * to do ITU Annex A, ANSI Annex D, and "Group-of-Four" variants
   46  * of the protocol.
   47  *
   48  * A specific protocol can be forced by connecting the corresponding
   49  * hook to DLCI 0 or 1023 (as appropriate) of a frame relay link.
   50  *
   51  * Alternately, this node can do auto-detection of the LMI protocol
   52  * by connecting hook "auto0" to DLCI 0 and "auto1023" to DLCI 1023.
   53  */
   54 
   55 #include <sys/param.h>
   56 #include <sys/systm.h>
   57 #include <sys/errno.h>
   58 #include <sys/kernel.h>
   59 #include <sys/malloc.h>
   60 #include <sys/mbuf.h>
   61 #include <sys/syslog.h>
   62 #include <netgraph/ng_message.h>
   63 #include <netgraph/netgraph.h>
   64 #include <netgraph/ng_lmi.h>
   65 
   66 /*
   67  * Human readable names for LMI
   68  */
   69 #define NAME_ANNEXA     NG_LMI_HOOK_ANNEXA
   70 #define NAME_ANNEXD     NG_LMI_HOOK_ANNEXD
   71 #define NAME_GROUP4     NG_LMI_HOOK_GROUPOF4
   72 #define NAME_NONE       "None"
   73 
   74 #define MAX_DLCIS       128
   75 #define MAXDLCI         1023
   76 
   77 /*
   78  * DLCI states
   79  */
   80 #define DLCI_NULL       0
   81 #define DLCI_UP         1
   82 #define DLCI_DOWN       2
   83 
   84 /*
   85  * Any received LMI frame should be at least this long
   86  */
   87 #define LMI_MIN_LENGTH  8       /* XXX verify */
   88 
   89 /*
   90  * Netgraph node methods and type descriptor
   91  */
   92 static ng_constructor_t nglmi_constructor;
   93 static ng_rcvmsg_t      nglmi_rcvmsg;
   94 static ng_shutdown_t    nglmi_shutdown;
   95 static ng_newhook_t     nglmi_newhook;
   96 static ng_rcvdata_t     nglmi_rcvdata;
   97 static ng_disconnect_t  nglmi_disconnect;
   98 static int      nglmi_checkdata(hook_p hook, struct mbuf *m);
   99 
  100 static struct ng_type typestruct = {
  101         NG_ABI_VERSION,
  102         NG_LMI_NODE_TYPE,
  103         NULL,
  104         nglmi_constructor,
  105         nglmi_rcvmsg,
  106         nglmi_shutdown,
  107         nglmi_newhook,
  108         NULL,
  109         NULL,
  110         nglmi_rcvdata,
  111         nglmi_disconnect,
  112         NULL
  113 };
  114 NETGRAPH_INIT(lmi, &typestruct);
  115 
  116 /*
  117  * Info and status per node
  118  */
  119 struct nglmi_softc {
  120         node_p  node;           /* netgraph node */
  121         int     flags;          /* state */
  122         int     poll_count;     /* the count of times for autolmi */
  123         int     poll_state;     /* state of auto detect machine */
  124         u_char  remote_seq;     /* sequence number the remote sent */
  125         u_char  local_seq;      /* last sequence number we sent */
  126         u_char  protoID;        /* 9 for group of 4, 8 otherwise */
  127         u_long  seq_retries;    /* sent this how many time so far */
  128         struct callout_handle handle;   /* see timeout(9) */
  129         int     liv_per_full;
  130         int     liv_rate;
  131         int     livs;
  132         int     need_full;
  133         hook_p  lmi_channel;    /* whatever we ended up using */
  134         hook_p  lmi_annexA;
  135         hook_p  lmi_annexD;
  136         hook_p  lmi_group4;
  137         hook_p  lmi_channel0;   /* auto-detect on DLCI 0 */
  138         hook_p  lmi_channel1023;/* auto-detect on DLCI 1023 */
  139         char   *protoname;      /* cache protocol name */
  140         u_char  dlci_state[MAXDLCI + 1];
  141         int     invalidx;       /* next dlci's to invalidate */
  142 };
  143 typedef struct nglmi_softc *sc_p;
  144 
  145 /*
  146  * Other internal functions
  147  */
  148 static void     LMI_ticker(void *arg);
  149 static void     nglmi_startup_fixed(sc_p sc, hook_p hook);
  150 static void     nglmi_startup_auto(sc_p sc);
  151 static void     nglmi_startup(sc_p sc);
  152 static void     nglmi_inquire(sc_p sc, int full);
  153 static void     ngauto_state_machine(sc_p sc);
  154 
  155 /*
  156  * Values for 'flags' field
  157  * NB: the SCF_CONNECTED flag is set if and only if the timer is running.
  158  */
  159 #define SCF_CONNECTED   0x01    /* connected to something */
  160 #define SCF_AUTO        0x02    /* we are auto-detecting */
  161 #define SCF_FIXED       0x04    /* we are fixed from the start */
  162 
  163 #define SCF_LMITYPE     0x18    /* mask for determining Annex mode */
  164 #define SCF_NOLMI       0x00    /* no LMI type selected yet */
  165 #define SCF_ANNEX_A     0x08    /* running annex A mode */
  166 #define SCF_ANNEX_D     0x10    /* running annex D mode */
  167 #define SCF_GROUP4      0x18    /* running group of 4 */
  168 
  169 #define SETLMITYPE(sc, annex)                                           \
  170 do {                                                                    \
  171         (sc)->flags &= ~SCF_LMITYPE;                                    \
  172         (sc)->flags |= (annex);                                         \
  173 } while (0)
  174 
  175 #define NOPROTO(sc) (((sc)->flags & SCF_LMITYPE) == SCF_NOLMI)
  176 #define ANNEXA(sc) (((sc)->flags & SCF_LMITYPE) == SCF_ANNEX_A)
  177 #define ANNEXD(sc) (((sc)->flags & SCF_LMITYPE) == SCF_ANNEX_D)
  178 #define GROUP4(sc) (((sc)->flags & SCF_LMITYPE) == SCF_GROUP4)
  179 
  180 #define LMIPOLLSIZE     3
  181 #define LMI_PATIENCE    8       /* declare all DLCI DOWN after N LMI failures */
  182 
  183 /*
  184  * Node constructor
  185  */
  186 static int
  187 nglmi_constructor(node_p node)
  188 {
  189         sc_p sc;
  190 
  191         MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_NOWAIT | M_ZERO);
  192         if (sc == NULL)
  193                 return (ENOMEM);
  194         callout_handle_init(&sc->handle);
  195         NG_NODE_SET_PRIVATE(node, sc);
  196         sc->protoname = NAME_NONE;
  197         sc->node = node;
  198         sc->liv_per_full = NG_LMI_SEQ_PER_FULL; /* make this dynamic */
  199         sc->liv_rate = NG_LMI_KEEPALIVE_RATE;
  200         return (0);
  201 }
  202 
  203 /*
  204  * The LMI channel has a private pointer which is the same as the
  205  * node private pointer. The debug channel has a NULL private pointer.
  206  */
  207 static int
  208 nglmi_newhook(node_p node, hook_p hook, const char *name)
  209 {
  210         sc_p sc = NG_NODE_PRIVATE(node);
  211 
  212         if (strcmp(name, NG_LMI_HOOK_DEBUG) == 0) {
  213                 NG_HOOK_SET_PRIVATE(hook, NULL);
  214                 return (0);
  215         }
  216         if (sc->flags & SCF_CONNECTED) {
  217                 /* already connected, return an error */
  218                 return (EINVAL);
  219         }
  220         if (strcmp(name, NG_LMI_HOOK_ANNEXA) == 0) {
  221                 sc->lmi_annexA = hook;
  222                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  223                 sc->protoID = 8;
  224                 SETLMITYPE(sc, SCF_ANNEX_A);
  225                 sc->protoname = NAME_ANNEXA;
  226                 nglmi_startup_fixed(sc, hook);
  227         } else if (strcmp(name, NG_LMI_HOOK_ANNEXD) == 0) {
  228                 sc->lmi_annexD = hook;
  229                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  230                 sc->protoID = 8;
  231                 SETLMITYPE(sc, SCF_ANNEX_D);
  232                 sc->protoname = NAME_ANNEXD;
  233                 nglmi_startup_fixed(sc, hook);
  234         } else if (strcmp(name, NG_LMI_HOOK_GROUPOF4) == 0) {
  235                 sc->lmi_group4 = hook;
  236                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  237                 sc->protoID = 9;
  238                 SETLMITYPE(sc, SCF_GROUP4);
  239                 sc->protoname = NAME_GROUP4;
  240                 nglmi_startup_fixed(sc, hook);
  241         } else if (strcmp(name, NG_LMI_HOOK_AUTO0) == 0) {
  242                 /* Note this, and if B is already installed, we're complete */
  243                 sc->lmi_channel0 = hook;
  244                 sc->protoname = NAME_NONE;
  245                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  246                 if (sc->lmi_channel1023)
  247                         nglmi_startup_auto(sc);
  248         } else if (strcmp(name, NG_LMI_HOOK_AUTO1023) == 0) {
  249                 /* Note this, and if A is already installed, we're complete */
  250                 sc->lmi_channel1023 = hook;
  251                 sc->protoname = NAME_NONE;
  252                 NG_HOOK_SET_PRIVATE(hook, NG_NODE_PRIVATE(node));
  253                 if (sc->lmi_channel0)
  254                         nglmi_startup_auto(sc);
  255         } else
  256                 return (EINVAL);                /* unknown hook */
  257         return (0);
  258 }
  259 
  260 /*
  261  * We have just attached to a live (we hope) node.
  262  * Fire out a LMI inquiry, and then start up the timers.
  263  */
  264 static void
  265 LMI_ticker(void *arg)
  266 {
  267         sc_p sc = arg;
  268         int s = splnet();
  269 
  270         if (sc->flags & SCF_AUTO) {
  271                 ngauto_state_machine(sc);
  272                 sc->handle = timeout(LMI_ticker, sc, NG_LMI_POLL_RATE * hz);
  273         } else {
  274                 if (sc->livs++ >= sc->liv_per_full) {
  275                         nglmi_inquire(sc, 1);
  276                         /* sc->livs = 0; *//* do this when we get the answer! */
  277                 } else {
  278                         nglmi_inquire(sc, 0);
  279                 }
  280                 sc->handle = timeout(LMI_ticker, sc, sc->liv_rate * hz);
  281         }
  282         splx(s);
  283 }
  284 
  285 static void
  286 nglmi_startup_fixed(sc_p sc, hook_p hook)
  287 {
  288         sc->flags |= (SCF_FIXED | SCF_CONNECTED);
  289         sc->lmi_channel = hook;
  290         nglmi_startup(sc);
  291 }
  292 
  293 static void
  294 nglmi_startup_auto(sc_p sc)
  295 {
  296         sc->flags |= (SCF_AUTO | SCF_CONNECTED);
  297         sc->poll_state = 0;     /* reset state machine */
  298         sc->poll_count = 0;
  299         nglmi_startup(sc);
  300 }
  301 
  302 static void
  303 nglmi_startup(sc_p sc)
  304 {
  305         sc->remote_seq = 0;
  306         sc->local_seq = 1;
  307         sc->seq_retries = 0;
  308         sc->livs = sc->liv_per_full - 1;
  309         /* start off the ticker in 1 sec */
  310         sc->handle = timeout(LMI_ticker, sc, hz);
  311 }
  312 
  313 #define META_PAD 16
  314 static void
  315 nglmi_inquire(sc_p sc, int full)
  316 {
  317         struct mbuf *m;
  318         char   *cptr, *start;
  319         int     error;
  320         meta_p  meta = NULL;
  321 
  322         if (sc->lmi_channel == NULL)
  323                 return;
  324         MGETHDR(m, M_DONTWAIT, MT_DATA);
  325         if (m == NULL) {
  326                 log(LOG_ERR, "nglmi: unable to start up LMI processing\n");
  327                 return;
  328         }
  329         m->m_pkthdr.rcvif = NULL;
  330         /* Allocate a meta struct (and leave some slop for options to be
  331          * added by other modules). */
  332         MALLOC(meta, meta_p, sizeof(*meta) + META_PAD, M_NETGRAPH_META, M_NOWAIT);
  333         if (meta != NULL) {     /* if it failed, well, it was optional anyhow */
  334                 meta->used_len = (u_short) sizeof(struct ng_meta);
  335                 meta->allocated_len
  336                     = (u_short) sizeof(struct ng_meta) + META_PAD;
  337                 meta->flags = 0;
  338                 meta->priority = NG_LMI_LMI_PRIORITY;
  339                 meta->discardability = -1;
  340         }
  341         m->m_data += 4;         /* leave some room for a header */
  342         cptr = start = mtod(m, char *);
  343         /* add in the header for an LMI inquiry. */
  344         *cptr++ = 0x03;         /* UI frame */
  345         if (GROUP4(sc))
  346                 *cptr++ = 0x09; /* proto discriminator */
  347         else
  348                 *cptr++ = 0x08; /* proto discriminator */
  349         *cptr++ = 0x00;         /* call reference */
  350         *cptr++ = 0x75;         /* inquiry */
  351 
  352         /* If we are Annex-D, there is this extra thing.. */
  353         if (ANNEXD(sc))
  354                 *cptr++ = 0x95; /* ??? */
  355         /* Add a request type */
  356         if (ANNEXA(sc))
  357                 *cptr++ = 0x51; /* report type */
  358         else
  359                 *cptr++ = 0x01; /* report type */
  360         *cptr++ = 0x01;         /* size = 1 */
  361         if (full)
  362                 *cptr++ = 0x00; /* full */
  363         else
  364                 *cptr++ = 0x01; /* partial */
  365 
  366         /* Add a link verification IE */
  367         if (ANNEXA(sc))
  368                 *cptr++ = 0x53; /* verification IE */
  369         else
  370                 *cptr++ = 0x03; /* verification IE */
  371         *cptr++ = 0x02;         /* 2 extra bytes */
  372         *cptr++ = sc->local_seq;
  373         *cptr++ = sc->remote_seq;
  374         sc->seq_retries++;
  375 
  376         /* Send it */
  377         m->m_len = m->m_pkthdr.len = cptr - start;
  378         NG_SEND_DATA(error, sc->lmi_channel, m, meta);
  379 
  380         /* If we've been sending requests for long enough, and there has
  381          * been no response, then mark as DOWN, any DLCIs that are UP. */
  382         if (sc->seq_retries == LMI_PATIENCE) {
  383                 int     count;
  384 
  385                 for (count = 0; count < MAXDLCI; count++)
  386                         if (sc->dlci_state[count] == DLCI_UP)
  387                                 sc->dlci_state[count] = DLCI_DOWN;
  388         }
  389 }
  390 
  391 /*
  392  * State machine for LMI auto-detect. The transitions are ordered
  393  * to try the more likely possibilities first.
  394  */
  395 static void
  396 ngauto_state_machine(sc_p sc)
  397 {
  398         if ((sc->poll_count <= 0) || (sc->poll_count > LMIPOLLSIZE)) {
  399                 /* time to change states in the auto probe machine */
  400                 /* capture wild values of poll_count while we are at it */
  401                 sc->poll_count = LMIPOLLSIZE;
  402                 sc->poll_state++;
  403         }
  404         switch (sc->poll_state) {
  405         case 7:
  406                 log(LOG_WARNING, "nglmi: no response from exchange\n");
  407         default:                /* capture bad states */
  408                 sc->poll_state = 1;
  409         case 1:
  410                 sc->lmi_channel = sc->lmi_channel0;
  411                 SETLMITYPE(sc, SCF_ANNEX_D);
  412                 break;
  413         case 2:
  414                 sc->lmi_channel = sc->lmi_channel1023;
  415                 SETLMITYPE(sc, SCF_ANNEX_D);
  416                 break;
  417         case 3:
  418                 sc->lmi_channel = sc->lmi_channel0;
  419                 SETLMITYPE(sc, SCF_ANNEX_A);
  420                 break;
  421         case 4:
  422                 sc->lmi_channel = sc->lmi_channel1023;
  423                 SETLMITYPE(sc, SCF_GROUP4);
  424                 break;
  425         case 5:
  426                 sc->lmi_channel = sc->lmi_channel1023;
  427                 SETLMITYPE(sc, SCF_ANNEX_A);
  428                 break;
  429         case 6:
  430                 sc->lmi_channel = sc->lmi_channel0;
  431                 SETLMITYPE(sc, SCF_GROUP4);
  432                 break;
  433         }
  434 
  435         /* send an inquirey encoded appropriatly */
  436         nglmi_inquire(sc, 0);
  437         sc->poll_count--;
  438 }
  439 
  440 /*
  441  * Receive a netgraph control message.
  442  */
  443 static int
  444 nglmi_rcvmsg(node_p node, item_p item, hook_p lasthook)
  445 {
  446         sc_p    sc = NG_NODE_PRIVATE(node);
  447         struct ng_mesg *resp = NULL;
  448         int     error = 0;
  449         struct ng_mesg *msg;
  450 
  451         NGI_GET_MSG(item, msg);
  452         switch (msg->header.typecookie) {
  453         case NGM_GENERIC_COOKIE:
  454                 switch (msg->header.cmd) {
  455                 case NGM_TEXT_STATUS:
  456                     {
  457                         char   *arg;
  458                         int     pos, count;
  459 
  460                         NG_MKRESPONSE(resp, msg, NG_TEXTRESPONSE, M_NOWAIT);
  461                         if (resp == NULL) {
  462                                 error = ENOMEM;
  463                                 break;
  464                         }
  465                         arg = resp->data;
  466                         pos = sprintf(arg, "protocol %s ", sc->protoname);
  467                         if (sc->flags & SCF_FIXED)
  468                                 pos += sprintf(arg + pos, "fixed\n");
  469                         else if (sc->flags & SCF_AUTO)
  470                                 pos += sprintf(arg + pos, "auto-detecting\n");
  471                         else
  472                                 pos += sprintf(arg + pos, "auto on dlci %d\n",
  473                                     (sc->lmi_channel == sc->lmi_channel0) ?
  474                                     0 : 1023);
  475                         pos += sprintf(arg + pos,
  476                             "keepalive period: %d seconds\n", sc->liv_rate);
  477                         pos += sprintf(arg + pos,
  478                             "unacknowledged keepalives: %ld\n",
  479                             sc->seq_retries);
  480                         for (count = 0;
  481                              ((count <= MAXDLCI)
  482                               && (pos < (NG_TEXTRESPONSE - 20)));
  483                              count++) {
  484                                 if (sc->dlci_state[count]) {
  485                                         pos += sprintf(arg + pos,
  486                                                "dlci %d %s\n", count,
  487                                                (sc->dlci_state[count]
  488                                         == DLCI_UP) ? "up" : "down");
  489                                 }
  490                         }
  491                         resp->header.arglen = pos + 1;
  492                         break;
  493                     }
  494                 default:
  495                         error = EINVAL;
  496                         break;
  497                 }
  498                 break;
  499         case NGM_LMI_COOKIE:
  500                 switch (msg->header.cmd) {
  501                 case NGM_LMI_GET_STATUS:
  502                     {
  503                         struct nglmistat *stat;
  504                         int k;
  505 
  506                         NG_MKRESPONSE(resp, msg, sizeof(*stat), M_NOWAIT);
  507                         if (!resp) {
  508                                 error = ENOMEM;
  509                                 break;
  510                         }
  511                         stat = (struct nglmistat *) resp->data;
  512                         strncpy(stat->proto,
  513                              sc->protoname, sizeof(stat->proto) - 1);
  514                         strncpy(stat->hook,
  515                               sc->protoname, sizeof(stat->hook) - 1);
  516                         stat->autod = !!(sc->flags & SCF_AUTO);
  517                         stat->fixed = !!(sc->flags & SCF_FIXED);
  518                         for (k = 0; k <= MAXDLCI; k++) {
  519                                 switch (sc->dlci_state[k]) {
  520                                 case DLCI_UP:
  521                                         stat->up[k / 8] |= (1 << (k % 8));
  522                                         /* fall through */
  523                                 case DLCI_DOWN:
  524                                         stat->seen[k / 8] |= (1 << (k % 8));
  525                                         break;
  526                                 }
  527                         }
  528                         break;
  529                     }
  530                 default:
  531                         error = EINVAL;
  532                         break;
  533                 }
  534                 break;
  535         default:
  536                 error = EINVAL;
  537                 break;
  538         }
  539 
  540         NG_RESPOND_MSG(error, node, item, resp);
  541         NG_FREE_MSG(msg);
  542         return (error);
  543 }
  544 
  545 #define STEPBY(stepsize)                        \
  546         do {                                    \
  547                 packetlen -= (stepsize);        \
  548                 data += (stepsize);             \
  549         } while (0)
  550 
  551 /*
  552  * receive data, and use it to update our status.
  553  * Anything coming in on the debug port is discarded.
  554  */
  555 static int
  556 nglmi_rcvdata(hook_p hook, item_p item)
  557 {
  558         sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  559         const   u_char *data;
  560         unsigned short dlci;
  561         u_short packetlen;
  562         int     resptype_seen = 0;
  563         int     seq_seen = 0;
  564         struct mbuf *m;
  565 
  566         NGI_GET_M(item, m);
  567         NG_FREE_ITEM(item);
  568         if (NG_HOOK_PRIVATE(hook) == NULL) {
  569                 goto drop;
  570         }
  571         packetlen = m->m_hdr.mh_len;
  572 
  573         /* XXX what if it's more than 1 mbuf? */
  574         if ((packetlen > MHLEN) && !(m->m_flags & M_EXT)) {
  575                 log(LOG_WARNING, "nglmi: packetlen (%d) too big\n", packetlen);
  576                 goto drop;
  577         }
  578         if (m->m_len < packetlen && (m = m_pullup(m, packetlen)) == NULL) {
  579                 log(LOG_WARNING,
  580                     "nglmi: m_pullup failed for %d bytes\n", packetlen);
  581                 return (0);
  582         }
  583         if (nglmi_checkdata(hook, m) == 0)
  584                 return (0);
  585 
  586         /* pass the first 4 bytes (already checked in the nglmi_checkdata()) */
  587         data = mtod(m, const u_char *);
  588         STEPBY(4);
  589 
  590         /* Now check if there is a 'locking shift'. This is only seen in
  591          * Annex D frames. don't bother checking, we already did that. Don't
  592          * increment immediatly as it might not be there. */
  593         if (ANNEXD(sc))
  594                 STEPBY(1);
  595 
  596         /* If we get this far we should consider that it is a legitimate
  597          * frame and we know what it is. */
  598         if (sc->flags & SCF_AUTO) {
  599                 /* note the hook that this valid channel came from and drop
  600                  * out of auto probe mode. */
  601                 if (ANNEXA(sc))
  602                         sc->protoname = NAME_ANNEXA;
  603                 else if (ANNEXD(sc))
  604                         sc->protoname = NAME_ANNEXD;
  605                 else if (GROUP4(sc))
  606                         sc->protoname = NAME_GROUP4;
  607                 else {
  608                         log(LOG_ERR, "nglmi: No known type\n");
  609                         goto drop;
  610                 }
  611                 sc->lmi_channel = hook;
  612                 sc->flags &= ~SCF_AUTO;
  613                 log(LOG_INFO, "nglmi: auto-detected %s LMI on DLCI %d\n",
  614                     sc->protoname, hook == sc->lmi_channel0 ? 0 : 1023);
  615         }
  616 
  617         /* While there is more data in the status packet, keep processing
  618          * status items. First make sure there is enough data for the
  619          * segment descriptor's length field. */
  620         while (packetlen >= 2) {
  621                 u_int   segtype = data[0];
  622                 u_int   segsize = data[1];
  623 
  624                 /* Now that we know how long it claims to be, make sure
  625                  * there is enough data for the next seg. */
  626                 if (packetlen < segsize + 2)
  627                         break;
  628                 switch (segtype) {
  629                 case 0x01:
  630                 case 0x51:
  631                         if (resptype_seen) {
  632                                 log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
  633                                 goto nextIE;
  634                         }
  635                         resptype_seen++;
  636                         /* The remote end tells us what kind of response
  637                          * this is. Only expect a type 0 or 1. if we are a
  638                          * full status, invalidate a few DLCIs just to see
  639                          * that they are still ok. */
  640                         if (segsize != 1)
  641                                 goto nextIE;
  642                         switch (data[2]) {
  643                         case 1:
  644                                 /* partial status, do no extra processing */
  645                                 break;
  646                         case 0:
  647                             {
  648                                 int     count = 0;
  649                                 int     idx = sc->invalidx;
  650 
  651                                 for (count = 0; count < 10; count++) {
  652                                         if (idx > MAXDLCI)
  653                                                 idx = 0;
  654                                         if (sc->dlci_state[idx] == DLCI_UP)
  655                                                 sc->dlci_state[idx] = DLCI_DOWN;
  656                                         idx++;
  657                                 }
  658                                 sc->invalidx = idx;
  659                                 /* we got and we wanted one. relax
  660                                  * now.. but don't reset to 0 if it
  661                                  * was unrequested. */
  662                                 if (sc->livs > sc->liv_per_full)
  663                                         sc->livs = 0;
  664                                 break;
  665                             }
  666                         }
  667                         break;
  668                 case 0x03:
  669                 case 0x53:
  670                         /* The remote tells us what it thinks the sequence
  671                          * numbers are. If it's not size 2, it must be a
  672                          * duplicate to have gotten this far, skip it. */
  673                         if (seq_seen != 0)      /* already seen seq numbers */
  674                                 goto nextIE;
  675                         if (segsize != 2)
  676                                 goto nextIE;
  677                         sc->remote_seq = data[2];
  678                         if (sc->local_seq == data[3]) {
  679                                 sc->local_seq++;
  680                                 sc->seq_retries = 0;
  681                                 /* Note that all 3 Frame protocols seem to
  682                                  * not like 0 as a sequence number. */
  683                                 if (sc->local_seq == 0)
  684                                         sc->local_seq = 1;
  685                         }
  686                         break;
  687                 case 0x07:
  688                 case 0x57:
  689                         /* The remote tells us about a DLCI that it knows
  690                          * about. There may be many of these in a single
  691                          * status response */
  692                         switch (segsize) {
  693                         case 6:/* only on 'group of 4' */
  694                                 dlci = ((u_short) data[2] & 0xff) << 8;
  695                                 dlci |= (data[3] & 0xff);
  696                                 if ((dlci < 1024) && (dlci > 0)) {
  697                                   /* XXX */
  698                                 }
  699                                 break;
  700                         case 3:
  701                                 dlci = ((u_short) data[2] & 0x3f) << 4;
  702                                 dlci |= ((data[3] & 0x78) >> 3);
  703                                 if ((dlci < 1024) && (dlci > 0)) {
  704                                         /* set up the bottom half of the
  705                                          * support for that dlci if it's not
  706                                          * already been done */
  707                                         /* store this information somewhere */
  708                                 }
  709                                 break;
  710                         default:
  711                                 goto nextIE;
  712                         }
  713                         if (sc->dlci_state[dlci] != DLCI_UP) {
  714                                 /* bring new DLCI to life */
  715                                 /* may do more here some day */
  716                                 if (sc->dlci_state[dlci] != DLCI_DOWN)
  717                                         log(LOG_INFO,
  718                                             "nglmi: DLCI %d became active\n",
  719                                             dlci);
  720                                 sc->dlci_state[dlci] = DLCI_UP;
  721                         }
  722                         break;
  723                 }
  724 nextIE:
  725                 STEPBY(segsize + 2);
  726         }
  727         NG_FREE_M(m);
  728         return (0);
  729 
  730 drop:
  731         NG_FREE_M(m);
  732         return (EINVAL);
  733 }
  734 
  735 /*
  736  * Check that a packet is entirely kosha.
  737  * return 1 of ok, and 0 if not.
  738  * All data is discarded if a 0 is returned.
  739  */
  740 static int
  741 nglmi_checkdata(hook_p hook, struct mbuf *m)
  742 {
  743         sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  744         const   u_char *data;
  745         u_short packetlen;
  746         unsigned short dlci;
  747         u_char  type;
  748         u_char  nextbyte;
  749         int     seq_seen = 0;
  750         int     resptype_seen = 0;      /* 0 , 1 (partial) or 2 (full) */
  751         int     highest_dlci = 0;
  752 
  753         packetlen = m->m_hdr.mh_len;
  754         data = mtod(m, const u_char *);
  755         if (*data != 0x03) {
  756                 log(LOG_WARNING, "nglmi: unexpected value in LMI(%d)\n", 1);
  757                 goto reject;
  758         }
  759         STEPBY(1);
  760 
  761         /* look at the protocol ID */
  762         nextbyte = *data;
  763         if (sc->flags & SCF_AUTO) {
  764                 SETLMITYPE(sc, SCF_NOLMI);      /* start with a clean slate */
  765                 switch (nextbyte) {
  766                 case 0x8:
  767                         sc->protoID = 8;
  768                         break;
  769                 case 0x9:
  770                         SETLMITYPE(sc, SCF_GROUP4);
  771                         sc->protoID = 9;
  772                         break;
  773                 default:
  774                         log(LOG_WARNING, "nglmi: bad Protocol ID(%d)\n",
  775                             (int) nextbyte);
  776                         goto reject;
  777                 }
  778         } else {
  779                 if (nextbyte != sc->protoID) {
  780                         log(LOG_WARNING, "nglmi: unexpected Protocol ID(%d)\n",
  781                             (int) nextbyte);
  782                         goto reject;
  783                 }
  784         }
  785         STEPBY(1);
  786 
  787         /* check call reference (always null in non ISDN frame relay) */
  788         if (*data != 0x00) {
  789                 log(LOG_WARNING, "nglmi: unexpected Call Reference (0x%x)\n",
  790                     data[-1]);
  791                 goto reject;
  792         }
  793         STEPBY(1);
  794 
  795         /* check message type */
  796         switch ((type = *data)) {
  797         case 0x75:              /* Status enquiry */
  798                 log(LOG_WARNING, "nglmi: unexpected message type(0x%x)\n",
  799                     data[-1]);
  800                 goto reject;
  801         case 0x7D:              /* Status message */
  802                 break;
  803         default:
  804                 log(LOG_WARNING,
  805                     "nglmi: unexpected msg type(0x%x) \n", (int) type);
  806                 goto reject;
  807         }
  808         STEPBY(1);
  809 
  810         /* Now check if there is a 'locking shift'. This is only seen in
  811          * Annex D frames. Don't increment immediately as it might not be
  812          * there. */
  813         nextbyte = *data;
  814         if (sc->flags & SCF_AUTO) {
  815                 if (!(GROUP4(sc))) {
  816                         if (nextbyte == 0x95) {
  817                                 SETLMITYPE(sc, SCF_ANNEX_D);
  818                                 STEPBY(1);
  819                         } else
  820                                 SETLMITYPE(sc, SCF_ANNEX_A);
  821                 } else if (nextbyte == 0x95) {
  822                         log(LOG_WARNING, "nglmi: locking shift seen in G4\n");
  823                         goto reject;
  824                 }
  825         } else {
  826                 if (ANNEXD(sc)) {
  827                         if (*data == 0x95)
  828                                 STEPBY(1);
  829                         else {
  830                                 log(LOG_WARNING,
  831                                     "nglmi: locking shift missing\n");
  832                                 goto reject;
  833                         }
  834                 } else if (*data == 0x95) {
  835                         log(LOG_WARNING, "nglmi: locking shift seen\n");
  836                         goto reject;
  837                 }
  838         }
  839 
  840         /* While there is more data in the status packet, keep processing
  841          * status items. First make sure there is enough data for the
  842          * segment descriptor's length field. */
  843         while (packetlen >= 2) {
  844                 u_int   segtype = data[0];
  845                 u_int   segsize = data[1];
  846 
  847                 /* Now that we know how long it claims to be, make sure
  848                  * there is enough data for the next seg. */
  849                 if (packetlen < (segsize + 2)) {
  850                         log(LOG_WARNING, "nglmi: IE longer than packet\n");
  851                         break;
  852                 }
  853                 switch (segtype) {
  854                 case 0x01:
  855                 case 0x51:
  856                         /* According to MCI's HP analyser, we should just
  857                          * ignore if there is mor ethan one of these (?). */
  858                         if (resptype_seen) {
  859                                 log(LOG_WARNING, "nglmi: dup MSGTYPE\n");
  860                                 goto nextIE;
  861                         }
  862                         if (segsize != 1) {
  863                                 log(LOG_WARNING, "nglmi: MSGTYPE wrong size\n");
  864                                 goto reject;
  865                         }
  866                         /* The remote end tells us what kind of response
  867                          * this is. Only expect a type 0 or 1. if it was a
  868                          * full (type 0) check we just asked for a type
  869                          * full. */
  870                         switch (data[2]) {
  871                         case 1:/* partial */
  872                                 if (sc->livs > sc->liv_per_full) {
  873                                         log(LOG_WARNING,
  874                                           "nglmi: LIV when FULL expected\n");
  875                                         goto reject;    /* need full */
  876                                 }
  877                                 resptype_seen = 1;
  878                                 break;
  879                         case 0:/* full */
  880                                 /* Full response is always acceptable */
  881                                 resptype_seen = 2;
  882                                 break;
  883                         default:
  884                                 log(LOG_WARNING,
  885                                  "nglmi: Unknown report type %d\n", data[2]);
  886                                 goto reject;
  887                         }
  888                         break;
  889                 case 0x03:
  890                 case 0x53:
  891                         /* The remote tells us what it thinks the sequence
  892                          * numbers are. I would have thought that there
  893                          * needs to be one and only one of these, but MCI
  894                          * want us to just ignore extras. (?) */
  895                         if (resptype_seen == 0) {
  896                                 log(LOG_WARNING, "nglmi: no TYPE before SEQ\n");
  897                                 goto reject;
  898                         }
  899                         if (seq_seen != 0)      /* already seen seq numbers */
  900                                 goto nextIE;
  901                         if (segsize != 2) {
  902                                 log(LOG_WARNING, "nglmi: bad SEQ sts size\n");
  903                                 goto reject;
  904                         }
  905                         if (sc->local_seq != data[3]) {
  906                                 log(LOG_WARNING, "nglmi: unexpected SEQ\n");
  907                                 goto reject;
  908                         }
  909                         seq_seen = 1;
  910                         break;
  911                 case 0x07:
  912                 case 0x57:
  913                         /* The remote tells us about a DLCI that it knows
  914                          * about. There may be many of these in a single
  915                          * status response */
  916                         if (seq_seen != 1) {    /* already seen seq numbers? */
  917                                 log(LOG_WARNING,
  918                                     "nglmi: No sequence before DLCI\n");
  919                                 goto reject;
  920                         }
  921                         if (resptype_seen != 2) {       /* must be full */
  922                                 log(LOG_WARNING,
  923                                     "nglmi: No resp type before DLCI\n");
  924                                 goto reject;
  925                         }
  926                         if (GROUP4(sc)) {
  927                                 if (segsize != 6) {
  928                                         log(LOG_WARNING,
  929                                             "nglmi: wrong IE segsize\n");
  930                                         goto reject;
  931                                 }
  932                                 dlci = ((u_short) data[2] & 0xff) << 8;
  933                                 dlci |= (data[3] & 0xff);
  934                         } else {
  935                                 if (segsize != 3) {
  936                                         log(LOG_WARNING,
  937                                             "nglmi: DLCI headersize of %d"
  938                                             " not supported\n", segsize - 1);
  939                                         goto reject;
  940                                 }
  941                                 dlci = ((u_short) data[2] & 0x3f) << 4;
  942                                 dlci |= ((data[3] & 0x78) >> 3);
  943                         }
  944                         /* async can only have one of these */
  945 #if 0                           /* async not yet accepted */
  946                         if (async && highest_dlci) {
  947                                 log(LOG_WARNING,
  948                                     "nglmi: Async with > 1 DLCI\n");
  949                                 goto reject;
  950                         }
  951 #endif
  952                         /* Annex D says these will always be Ascending, but
  953                          * the HP test for G4 says we should accept
  954                          * duplicates, so for now allow that. ( <= vs. < ) */
  955 #if 0
  956                         /* MCI tests want us to accept out of order for AnxD */
  957                         if ((!GROUP4(sc)) && (dlci < highest_dlci)) {
  958                                 /* duplicate or mis-ordered dlci */
  959                                 /* (spec says they will increase in number) */
  960                                 log(LOG_WARNING, "nglmi: DLCI out of order\n");
  961                                 goto reject;
  962                         }
  963 #endif
  964                         if (dlci > 1023) {
  965                                 log(LOG_WARNING, "nglmi: DLCI out of range\n");
  966                                 goto reject;
  967                         }
  968                         highest_dlci = dlci;
  969                         break;
  970                 default:
  971                         log(LOG_WARNING,
  972                             "nglmi: unknown LMI segment type %d\n", segtype);
  973                 }
  974 nextIE:
  975                 STEPBY(segsize + 2);
  976         }
  977         if (packetlen != 0) {   /* partial junk at end? */
  978                 log(LOG_WARNING,
  979                     "nglmi: %d bytes extra at end of packet\n", packetlen);
  980                 goto print;
  981         }
  982         if (resptype_seen == 0) {
  983                 log(LOG_WARNING, "nglmi: No response type seen\n");
  984                 goto reject;    /* had no response type */
  985         }
  986         if (seq_seen == 0) {
  987                 log(LOG_WARNING, "nglmi: No sequence numbers seen\n");
  988                 goto reject;    /* had no sequence numbers */
  989         }
  990         return (1);
  991 
  992 print:
  993         {
  994                 int     i, j, k, pos;
  995                 char    buf[100];
  996                 int     loc;
  997                 const   u_char *bp = mtod(m, const u_char *);
  998 
  999                 k = i = 0;
 1000                 loc = (m->m_hdr.mh_len - packetlen);
 1001                 log(LOG_WARNING, "nglmi: error at location %d\n", loc);
 1002                 while (k < m->m_hdr.mh_len) {
 1003                         pos = 0;
 1004                         j = 0;
 1005                         while ((j++ < 16) && k < m->m_hdr.mh_len) {
 1006                                 pos += sprintf(buf + pos, "%c%02x",
 1007                                                ((loc == k) ? '>' : ' '),
 1008                                                bp[k]);
 1009                                 k++;
 1010                         }
 1011                         if (i == 0)
 1012                                 log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
 1013                         else
 1014                                 log(LOG_WARNING, "%04d              :%s\n", k, buf);
 1015                         i++;
 1016                 }
 1017         }
 1018         return (1);
 1019 reject:
 1020         {
 1021                 int     i, j, k, pos;
 1022                 char    buf[100];
 1023                 int     loc;
 1024                 const   u_char *bp = mtod(m, const u_char *);
 1025 
 1026                 k = i = 0;
 1027                 loc = (m->m_hdr.mh_len - packetlen);
 1028                 log(LOG_WARNING, "nglmi: error at location %d\n", loc);
 1029                 while (k < m->m_hdr.mh_len) {
 1030                         pos = 0;
 1031                         j = 0;
 1032                         while ((j++ < 16) && k < m->m_hdr.mh_len) {
 1033                                 pos += sprintf(buf + pos, "%c%02x",
 1034                                                ((loc == k) ? '>' : ' '),
 1035                                                bp[k]);
 1036                                 k++;
 1037                         }
 1038                         if (i == 0)
 1039                                 log(LOG_WARNING, "nglmi: packet data:%s\n", buf);
 1040                         else
 1041                                 log(LOG_WARNING, "%04d              :%s\n", k, buf);
 1042                         i++;
 1043                 }
 1044         }
 1045         NG_FREE_M(m);
 1046         return (0);
 1047 }
 1048 
 1049 /*
 1050  * Do local shutdown processing..
 1051  * Cut any remaining links and free our local resources.
 1052  */
 1053 static int
 1054 nglmi_shutdown(node_p node)
 1055 {
 1056         const sc_p sc = NG_NODE_PRIVATE(node);
 1057 
 1058         NG_NODE_SET_PRIVATE(node, NULL);
 1059         NG_NODE_UNREF(sc->node);
 1060         FREE(sc, M_NETGRAPH);
 1061         return (0);
 1062 }
 1063 
 1064 /*
 1065  * Hook disconnection
 1066  * For this type, removal of any link except "debug" destroys the node.
 1067  */
 1068 static int
 1069 nglmi_disconnect(hook_p hook)
 1070 {
 1071         const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 1072 
 1073         /* OK to remove debug hook(s) */
 1074         if (NG_HOOK_PRIVATE(hook) == NULL)
 1075                 return (0);
 1076 
 1077         /* Stop timer if it's currently active */
 1078         if (sc->flags & SCF_CONNECTED)
 1079                 untimeout(LMI_ticker, sc, sc->handle);
 1080 
 1081         /* Self-destruct */
 1082         if (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
 1083                 ng_rmnode_self(NG_HOOK_NODE(hook));
 1084         return (0);
 1085 }
 1086 

Cache object: 568f4d136c429fe8c62791f736451dc0


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