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

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    1 
    2 /*
    3  * ng_tty.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: Archie Cobbs <archie@freebsd.org>
   38  *
   39  * $FreeBSD: releng/5.1/sys/netgraph/ng_tty.c 111119 2003-02-19 05:47:46Z imp $
   40  * $Whistle: ng_tty.c,v 1.21 1999/11/01 09:24:52 julian Exp $
   41  */
   42 
   43 /*
   44  * This file implements a terminal line discipline that is also a
   45  * netgraph node. Installing this line discipline on a terminal device
   46  * instantiates a new netgraph node of this type, which allows access
   47  * to the device via the "hook" hook of the node.
   48  *
   49  * Once the line discipline is installed, you can find out the name
   50  * of the corresponding netgraph node via a NGIOCGINFO ioctl().
   51  *
   52  * Incoming characters are delievered to the hook one at a time, each
   53  * in its own mbuf. You may optionally define a ``hotchar,'' which causes
   54  * incoming characters to be buffered up until either the hotchar is
   55  * seen or the mbuf is full (MHLEN bytes). Then all buffered characters
   56  * are immediately delivered.
   57  *
   58  * NOTE: This node operates at spltty().
   59  */
   60 
   61 #include <sys/param.h>
   62 #include <sys/systm.h>
   63 #include <sys/kernel.h>
   64 #include <sys/conf.h>
   65 #include <sys/mbuf.h>
   66 #include <sys/malloc.h>
   67 #include <sys/fcntl.h>
   68 #include <sys/tty.h>
   69 #include <sys/ttycom.h>
   70 #include <sys/syslog.h>
   71 #include <sys/errno.h>
   72 #include <sys/ioccom.h>
   73 
   74 #include <netgraph/ng_message.h>
   75 #include <netgraph/netgraph.h>
   76 #include <netgraph/ng_tty.h>
   77 
   78 /* Misc defs */
   79 #define MAX_MBUFQ               3       /* Max number of queued mbufs */
   80 #define NGT_HIWATER             400     /* High water mark on output */
   81 
   82 /* Per-node private info */
   83 struct ngt_sc {
   84         struct  tty *tp;                /* Terminal device */
   85         node_p  node;                   /* Netgraph node */
   86         hook_p  hook;                   /* Netgraph hook */
   87         struct  mbuf *m;                /* Incoming data buffer */
   88         struct  mbuf *qhead, **qtail;   /* Queue of outgoing mbuf's */
   89         short   qlen;                   /* Length of queue */
   90         short   hotchar;                /* Hotchar, or -1 if none */
   91         u_int   flags;                  /* Flags */
   92         struct  callout_handle chand;   /* See man timeout(9) */
   93 };
   94 typedef struct ngt_sc *sc_p;
   95 
   96 /* Flags */
   97 #define FLG_TIMEOUT             0x0001  /* A timeout is pending */
   98 #define FLG_DEBUG               0x0002
   99 
  100 /* Debugging */
  101 #ifdef INVARIANTS
  102 #define QUEUECHECK(sc)                                                  \
  103     do {                                                                \
  104       struct mbuf       **mp;                                           \
  105       int               k;                                              \
  106                                                                         \
  107       for (k = 0, mp = &sc->qhead;                                      \
  108         k <= MAX_MBUFQ && *mp;                                          \
  109         k++, mp = &(*mp)->m_nextpkt);                                   \
  110       if (k != sc->qlen || k > MAX_MBUFQ || *mp || mp != sc->qtail)     \
  111         panic("%s: queue", __func__);                                   \
  112     } while (0)
  113 #else
  114 #define QUEUECHECK(sc)  do {} while (0)
  115 #endif
  116 
  117 /* Line discipline methods */
  118 static int      ngt_open(dev_t dev, struct tty *tp);
  119 static int      ngt_close(struct tty *tp, int flag);
  120 static int      ngt_read(struct tty *tp, struct uio *uio, int flag);
  121 static int      ngt_write(struct tty *tp, struct uio *uio, int flag);
  122 static int      ngt_tioctl(struct tty *tp,
  123                     u_long cmd, caddr_t data, int flag, struct thread *);
  124 static int      ngt_input(int c, struct tty *tp);
  125 static int      ngt_start(struct tty *tp);
  126 
  127 /* Netgraph methods */
  128 static ng_constructor_t ngt_constructor;
  129 static ng_rcvmsg_t      ngt_rcvmsg;
  130 static ng_shutdown_t    ngt_shutdown;
  131 static ng_newhook_t     ngt_newhook;
  132 static ng_connect_t     ngt_connect;
  133 static ng_rcvdata_t     ngt_rcvdata;
  134 static ng_disconnect_t  ngt_disconnect;
  135 static int      ngt_mod_event(module_t mod, int event, void *data);
  136 
  137 /* Other stuff */
  138 static void     ngt_timeout(void *arg);
  139 
  140 #define ERROUT(x)               do { error = (x); goto done; } while (0)
  141 
  142 /* Line discipline descriptor */
  143 static struct linesw ngt_disc = {
  144         ngt_open,
  145         ngt_close,
  146         ngt_read,
  147         ngt_write,
  148         ngt_tioctl,
  149         ngt_input,
  150         ngt_start,
  151         ttymodem,
  152         NG_TTY_DFL_HOTCHAR      /* XXX can't change this in serial driver */
  153 };
  154 
  155 /* Netgraph node type descriptor */
  156 static struct ng_type typestruct = {
  157         NG_ABI_VERSION,
  158         NG_TTY_NODE_TYPE,
  159         ngt_mod_event,
  160         ngt_constructor,
  161         ngt_rcvmsg,
  162         ngt_shutdown,
  163         ngt_newhook,
  164         NULL,
  165         ngt_connect,
  166         ngt_rcvdata,
  167         ngt_disconnect,
  168         NULL
  169 };
  170 NETGRAPH_INIT(tty, &typestruct);
  171 
  172 static int ngt_unit;
  173 static int ngt_nodeop_ok;       /* OK to create/remove node */
  174 static int ngt_ldisc;
  175 
  176 /******************************************************************
  177                     LINE DISCIPLINE METHODS
  178 ******************************************************************/
  179 
  180 /*
  181  * Set our line discipline on the tty.
  182  * Called from device open routine or ttioctl() at >= splsofttty()
  183  */
  184 static int
  185 ngt_open(dev_t dev, struct tty *tp)
  186 {
  187         struct thread *const td = curthread;    /* XXX */
  188         char name[sizeof(NG_TTY_NODE_TYPE) + 8];
  189         sc_p sc;
  190         int s, error;
  191 
  192         /* Super-user only */
  193         if ((error = suser(td)))
  194                 return (error);
  195         s = splnet();
  196         (void) spltty();        /* XXX is this necessary? */
  197 
  198         /* Already installed? */
  199         if (tp->t_line == NETGRAPHDISC) {
  200                 sc = (sc_p) tp->t_sc;
  201                 if (sc != NULL && sc->tp == tp)
  202                         goto done;
  203         }
  204 
  205         /* Initialize private struct */
  206         MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_WAITOK | M_ZERO);
  207         if (sc == NULL) {
  208                 error = ENOMEM;
  209                 goto done;
  210         }
  211         sc->tp = tp;
  212         sc->hotchar = NG_TTY_DFL_HOTCHAR;
  213         sc->qtail = &sc->qhead;
  214         QUEUECHECK(sc);
  215         callout_handle_init(&sc->chand);
  216 
  217         /* Setup netgraph node */
  218         ngt_nodeop_ok = 1;
  219         error = ng_make_node_common(&typestruct, &sc->node);
  220         ngt_nodeop_ok = 0;
  221         if (error) {
  222                 FREE(sc, M_NETGRAPH);
  223                 goto done;
  224         }
  225         snprintf(name, sizeof(name), "%s%d", typestruct.name, ngt_unit++);
  226 
  227         /* Assign node its name */
  228         if ((error = ng_name_node(sc->node, name))) {
  229                 log(LOG_ERR, "%s: node name exists?\n", name);
  230                 ngt_nodeop_ok = 1;
  231                 NG_NODE_UNREF(sc->node);
  232                 ngt_nodeop_ok = 0;
  233                 goto done;
  234         }
  235 
  236         /* Set back pointers */
  237         NG_NODE_SET_PRIVATE(sc->node, sc);
  238         tp->t_sc = (caddr_t) sc;
  239 
  240         /*
  241          * Pre-allocate cblocks to the an appropriate amount.
  242          * I'm not sure what is appropriate.
  243          */
  244         ttyflush(tp, FREAD | FWRITE);
  245         clist_alloc_cblocks(&tp->t_canq, 0, 0);
  246         clist_alloc_cblocks(&tp->t_rawq, 0, 0);
  247         clist_alloc_cblocks(&tp->t_outq,
  248             MLEN + NGT_HIWATER, MLEN + NGT_HIWATER);
  249 
  250 done:
  251         /* Done */
  252         splx(s);
  253         return (error);
  254 }
  255 
  256 /*
  257  * Line specific close routine, called from device close routine
  258  * and from ttioctl at >= splsofttty(). This causes the node to
  259  * be destroyed as well.
  260  */
  261 static int
  262 ngt_close(struct tty *tp, int flag)
  263 {
  264         const sc_p sc = (sc_p) tp->t_sc;
  265         int s;
  266 
  267         s = spltty();
  268         ttyflush(tp, FREAD | FWRITE);
  269         clist_free_cblocks(&tp->t_outq);
  270         tp->t_line = 0;
  271         if (sc != NULL) {
  272                 if (sc->flags & FLG_TIMEOUT) {
  273                         untimeout(ngt_timeout, sc, sc->chand);
  274                         sc->flags &= ~FLG_TIMEOUT;
  275                 }
  276                 ngt_nodeop_ok = 1;
  277                 ng_rmnode_self(sc->node);
  278                 ngt_nodeop_ok = 0;
  279                 tp->t_sc = NULL;
  280         }
  281         splx(s);
  282         return (0);
  283 }
  284 
  285 /*
  286  * Once the device has been turned into a node, we don't allow reading.
  287  */
  288 static int
  289 ngt_read(struct tty *tp, struct uio *uio, int flag)
  290 {
  291         return (EIO);
  292 }
  293 
  294 /*
  295  * Once the device has been turned into a node, we don't allow writing.
  296  */
  297 static int
  298 ngt_write(struct tty *tp, struct uio *uio, int flag)
  299 {
  300         return (EIO);
  301 }
  302 
  303 /*
  304  * We implement the NGIOCGINFO ioctl() defined in ng_message.h.
  305  */
  306 static int
  307 ngt_tioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, struct thread *td)
  308 {
  309         const sc_p sc = (sc_p) tp->t_sc;
  310         int s, error = 0;
  311 
  312         s = spltty();
  313         switch (cmd) {
  314         case NGIOCGINFO:
  315             {
  316                 struct nodeinfo *const ni = (struct nodeinfo *) data;
  317                 const node_p node = sc->node;
  318 
  319                 bzero(ni, sizeof(*ni));
  320                 if (NG_NODE_HAS_NAME(node))
  321                         strncpy(ni->name, NG_NODE_NAME(node), sizeof(ni->name) - 1);
  322                 strncpy(ni->type, node->nd_type->name, sizeof(ni->type) - 1);
  323                 ni->id = (u_int32_t) ng_node2ID(node);
  324                 ni->hooks = NG_NODE_NUMHOOKS(node);
  325                 break;
  326             }
  327         default:
  328                 ERROUT(ENOIOCTL);
  329         }
  330 done:
  331         splx(s);
  332         return (error);
  333 }
  334 
  335 /*
  336  * Receive data coming from the device. We get one character at
  337  * a time, which is kindof silly.
  338  * Only guaranteed to be at splsofttty() or spltty().
  339  */
  340 static int
  341 ngt_input(int c, struct tty *tp)
  342 {
  343         const sc_p sc = (sc_p) tp->t_sc;
  344         const node_p node = sc->node;
  345         struct mbuf *m;
  346         int s, error = 0;
  347 
  348         if (!sc || tp != sc->tp)
  349                 return (0);
  350         s = spltty();
  351         if (!sc->hook)
  352                 ERROUT(0);
  353 
  354         /* Check for error conditions */
  355         if ((tp->t_state & TS_CONNECTED) == 0) {
  356                 if (sc->flags & FLG_DEBUG)
  357                         log(LOG_DEBUG, "%s: no carrier\n", NG_NODE_NAME(node));
  358                 ERROUT(0);
  359         }
  360         if (c & TTY_ERRORMASK) {
  361                 /* framing error or overrun on this char */
  362                 if (sc->flags & FLG_DEBUG)
  363                         log(LOG_DEBUG, "%s: line error %x\n",
  364                             NG_NODE_NAME(node), c & TTY_ERRORMASK);
  365                 ERROUT(0);
  366         }
  367         c &= TTY_CHARMASK;
  368 
  369         /* Get a new header mbuf if we need one */
  370         if (!(m = sc->m)) {
  371                 MGETHDR(m, M_DONTWAIT, MT_DATA);
  372                 if (!m) {
  373                         if (sc->flags & FLG_DEBUG)
  374                                 log(LOG_ERR,
  375                                     "%s: can't get mbuf\n", NG_NODE_NAME(node));
  376                         ERROUT(ENOBUFS);
  377                 }
  378                 m->m_len = m->m_pkthdr.len = 0;
  379                 m->m_pkthdr.rcvif = NULL;
  380                 sc->m = m;
  381         }
  382 
  383         /* Add char to mbuf */
  384         *mtod(m, u_char *) = c;
  385         m->m_data++;
  386         m->m_len++;
  387         m->m_pkthdr.len++;
  388 
  389         /* Ship off mbuf if it's time */
  390         if (sc->hotchar == -1 || c == sc->hotchar || m->m_len >= MHLEN) {
  391                 m->m_data = m->m_pktdat;
  392                 NG_SEND_DATA_ONLY(error, sc->hook, m);
  393                 sc->m = NULL;
  394         }
  395 done:
  396         splx(s);
  397         return (error);
  398 }
  399 
  400 /*
  401  * This is called when the device driver is ready for more output.
  402  * Called from tty system at splsofttty() or spltty().
  403  * Also call from ngt_rcv_data() when a new mbuf is available for output.
  404  */
  405 static int
  406 ngt_start(struct tty *tp)
  407 {
  408         const sc_p sc = (sc_p) tp->t_sc;
  409         int s;
  410 
  411         s = spltty();
  412         while (tp->t_outq.c_cc < NGT_HIWATER) { /* XXX 2.2 specific ? */
  413                 struct mbuf *m = sc->qhead;
  414 
  415                 /* Remove first mbuf from queue */
  416                 if (!m)
  417                         break;
  418                 if ((sc->qhead = m->m_nextpkt) == NULL)
  419                         sc->qtail = &sc->qhead;
  420                 sc->qlen--;
  421                 QUEUECHECK(sc);
  422 
  423                 /* Send as much of it as possible */
  424                 while (m) {
  425                         int     sent;
  426 
  427                         sent = m->m_len
  428                             - b_to_q(mtod(m, u_char *), m->m_len, &tp->t_outq);
  429                         m->m_data += sent;
  430                         m->m_len -= sent;
  431                         if (m->m_len > 0)
  432                                 break;  /* device can't take no more */
  433                         m = m_free(m);
  434                 }
  435 
  436                 /* Put remainder of mbuf chain (if any) back on queue */
  437                 if (m) {
  438                         m->m_nextpkt = sc->qhead;
  439                         sc->qhead = m;
  440                         if (sc->qtail == &sc->qhead)
  441                                 sc->qtail = &m->m_nextpkt;
  442                         sc->qlen++;
  443                         QUEUECHECK(sc);
  444                         break;
  445                 }
  446         }
  447 
  448         /* Call output process whether or not there is any output. We are
  449          * being called in lieu of ttstart and must do what it would. */
  450         if (tp->t_oproc != NULL)
  451                 (*tp->t_oproc) (tp);
  452 
  453         /* This timeout is needed for operation on a pseudo-tty, because the
  454          * pty code doesn't call pppstart after it has drained the t_outq. */
  455         if (sc->qhead && (sc->flags & FLG_TIMEOUT) == 0) {
  456                 sc->chand = timeout(ngt_timeout, sc, 1);
  457                 sc->flags |= FLG_TIMEOUT;
  458         }
  459         splx(s);
  460         return (0);
  461 }
  462 
  463 /*
  464  * We still have data to output to the device, so try sending more.
  465  */
  466 static void
  467 ngt_timeout(void *arg)
  468 {
  469         const sc_p sc = (sc_p) arg;
  470         int s;
  471 
  472         s = spltty();
  473         sc->flags &= ~FLG_TIMEOUT;
  474         ngt_start(sc->tp);
  475         splx(s);
  476 }
  477 
  478 /******************************************************************
  479                     NETGRAPH NODE METHODS
  480 ******************************************************************/
  481 
  482 /*
  483  * Initialize a new node of this type.
  484  *
  485  * We only allow nodes to be created as a result of setting
  486  * the line discipline on a tty, so always return an error if not.
  487  */
  488 static int
  489 ngt_constructor(node_p node)
  490 {
  491         return (EOPNOTSUPP);
  492 }
  493 
  494 /*
  495  * Add a new hook. There can only be one.
  496  */
  497 static int
  498 ngt_newhook(node_p node, hook_p hook, const char *name)
  499 {
  500         const sc_p sc = NG_NODE_PRIVATE(node);
  501         int s, error = 0;
  502 
  503         if (strcmp(name, NG_TTY_HOOK))
  504                 return (EINVAL);
  505         s = spltty();
  506         if (sc->hook)
  507                 ERROUT(EISCONN);
  508         sc->hook = hook;
  509 done:
  510         splx(s);
  511         return (error);
  512 }
  513 
  514 /*
  515  * Set the hooks into queueing mode (for outgoing packets)
  516  * Force single client at a time.
  517  */
  518 static int
  519 ngt_connect(hook_p hook)
  520 {
  521         /*NG_HOOK_FORCE_WRITER(hook);
  522         NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));*/
  523         return (0);
  524 }
  525 
  526 /*
  527  * Disconnect the hook
  528  */
  529 static int
  530 ngt_disconnect(hook_p hook)
  531 {
  532         const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  533         int s;
  534 
  535         s = spltty();
  536         if (hook != sc->hook)
  537                 panic(__func__);
  538         sc->hook = NULL;
  539         m_freem(sc->m);
  540         sc->m = NULL;
  541         splx(s);
  542         return (0);
  543 }
  544 
  545 /*
  546  * Remove this node. The does the netgraph portion of the shutdown.
  547  * This should only be called indirectly from ngt_close().
  548  */
  549 static int
  550 ngt_shutdown(node_p node)
  551 {
  552         const sc_p sc = NG_NODE_PRIVATE(node);
  553 
  554         if (!ngt_nodeop_ok)
  555                 return (EOPNOTSUPP);
  556         NG_NODE_SET_PRIVATE(node, NULL);
  557         NG_NODE_UNREF(sc->node);
  558         m_freem(sc->qhead);
  559         m_freem(sc->m);
  560         bzero(sc, sizeof(*sc));
  561         FREE(sc, M_NETGRAPH);
  562         return (0);
  563 }
  564 
  565 /*
  566  * Receive incoming data from netgraph system. Put it on our
  567  * output queue and start output if necessary.
  568  */
  569 static int
  570 ngt_rcvdata(hook_p hook, item_p item)
  571 {
  572         const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
  573         int s, error = 0;
  574         struct mbuf *m;
  575 
  576         if (hook != sc->hook)
  577                 panic(__func__);
  578 
  579         NGI_GET_M(item, m);
  580         NG_FREE_ITEM(item);
  581         s = spltty();
  582         if (sc->qlen >= MAX_MBUFQ)
  583                 ERROUT(ENOBUFS);
  584         m->m_nextpkt = NULL;
  585         *sc->qtail = m;
  586         sc->qtail = &m->m_nextpkt;
  587         sc->qlen++;
  588         QUEUECHECK(sc);
  589         m = NULL;
  590         if (sc->qlen == 1)
  591                 ngt_start(sc->tp);
  592 done:
  593         splx(s);
  594         if (m)
  595                 m_freem(m);
  596         return (error);
  597 }
  598 
  599 /*
  600  * Receive control message
  601  */
  602 static int
  603 ngt_rcvmsg(node_p node, item_p item, hook_p lasthook)
  604 {
  605         const sc_p sc = NG_NODE_PRIVATE(node);
  606         struct ng_mesg *resp = NULL;
  607         int error = 0;
  608         struct ng_mesg *msg;
  609 
  610         NGI_GET_MSG(item, msg);
  611         switch (msg->header.typecookie) {
  612         case NGM_TTY_COOKIE:
  613                 switch (msg->header.cmd) {
  614                 case NGM_TTY_SET_HOTCHAR:
  615                     {
  616                         int     hotchar;
  617 
  618                         if (msg->header.arglen != sizeof(int))
  619                                 ERROUT(EINVAL);
  620                         hotchar = *((int *) msg->data);
  621                         if (hotchar != (u_char) hotchar && hotchar != -1)
  622                                 ERROUT(EINVAL);
  623                         sc->hotchar = hotchar;  /* race condition is OK */
  624                         break;
  625                     }
  626                 case NGM_TTY_GET_HOTCHAR:
  627                         NG_MKRESPONSE(resp, msg, sizeof(int), M_NOWAIT);
  628                         if (!resp)
  629                                 ERROUT(ENOMEM);
  630                         /* Race condition here is OK */
  631                         *((int *) resp->data) = sc->hotchar;
  632                         break;
  633                 default:
  634                         ERROUT(EINVAL);
  635                 }
  636                 break;
  637         default:
  638                 ERROUT(EINVAL);
  639         }
  640 done:
  641         NG_RESPOND_MSG(error, node, item, resp);
  642         NG_FREE_MSG(msg);
  643         return (error);
  644 }
  645 
  646 /******************************************************************
  647                         INITIALIZATION
  648 ******************************************************************/
  649 
  650 /*
  651  * Handle loading and unloading for this node type
  652  */
  653 static int
  654 ngt_mod_event(module_t mod, int event, void *data)
  655 {
  656         /* struct ng_type *const type = data;*/
  657         int s, error = 0;
  658 
  659         switch (event) {
  660         case MOD_LOAD:
  661 
  662                 /* Register line discipline */
  663                 s = spltty();
  664                 if ((ngt_ldisc = ldisc_register(NETGRAPHDISC, &ngt_disc)) < 0) {
  665                         splx(s);
  666                         log(LOG_ERR, "%s: can't register line discipline",
  667                             __func__);
  668                         return (EIO);
  669                 }
  670                 splx(s);
  671                 break;
  672 
  673         case MOD_UNLOAD:
  674 
  675                 /* Unregister line discipline */
  676                 s = spltty();
  677                 ldisc_deregister(ngt_ldisc);
  678                 splx(s);
  679                 break;
  680 
  681         default:
  682                 error = EOPNOTSUPP;
  683                 break;
  684         }
  685         return (error);
  686 }
  687 

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