sys/netgraph7/bluetooth/drivers/h4/ng_h4.c

   1 /*
   2  * ng_h4.c
   3  */
   4
   5 /*-
   6  * Copyright (c) 2001-2002 Maksim Yevmenkin <m_evmenkin@yahoo.com>
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  * $Id: ng_h4.c,v 1.10 2005/10/31 17:57:43 max Exp $
  31  * $FreeBSD: src/sys/netgraph/bluetooth/drivers/h4/ng_h4.c,v 1.17 2007/08/13 17:19:28 emax Exp $
  32  *
  33  * Based on:
  34  * ---------
  35  *
  36  * FreeBSD: src/sys/netgraph/ng_tty.c
  37  * Author: Archie Cobbs <archie@freebsd.org>
  38  *
  39  */
  40
  41 #include <sys/param.h>
  42 #include <sys/systm.h>
  43 #include <sys/kernel.h>
  44 #include <sys/conf.h>
  45 #include <sys/endian.h>
  46 #include <sys/errno.h>
  47 #include <sys/fcntl.h>
  48 #include <sys/ioccom.h>
  49 #include <sys/malloc.h>
  50 #include <sys/mbuf.h>
  51 #include <sys/priv.h>
  52 #include <sys/socket.h>
  53 #include <sys/tty.h>
  54 #include <sys/ttycom.h>
  55 #include <net/if.h>
  56 #include <net/if_var.h>
  57 #include <netgraph/ng_message.h>
  58 #include <netgraph/netgraph.h>
  59 #include <netgraph/ng_parse.h>
  60 #include <netgraph/bluetooth/include/ng_bluetooth.h>
  61 #include <netgraph/bluetooth/include/ng_hci.h>
  62 #include <netgraph/bluetooth/include/ng_h4.h>
  63 #include <netgraph/bluetooth/drivers/h4/ng_h4_var.h>
  64 #include <netgraph/bluetooth/drivers/h4/ng_h4_prse.h>
  65
  66 /*****************************************************************************
  67  *****************************************************************************
  68  ** This node implements a Bluetooth HCI UART transport layer as per chapter
  69  ** H4 of the Bluetooth Specification Book v1.1. It is a terminal line
  70  ** discipline that is also a netgraph node. Installing this line discipline
  71  ** on a terminal device instantiates a new netgraph node of this type, which
  72  ** allows access to the device via the "hook" hook of the node.
  73  **
  74  ** Once the line discipline is installed, you can find out the name of the
  75  ** corresponding netgraph node via a NGIOCGINFO ioctl().
  76  *****************************************************************************
  77  *****************************************************************************/
  78
  79 /* MALLOC define */
  80 #ifndef NG_SEPARATE_MALLOC
  81 MALLOC_DEFINE(M_NETGRAPH_H4, "netgraph_h4", "Netgraph Bluetooth H4 node");
  82 #else
  83 #define M_NETGRAPH_H4 M_NETGRAPH
  84 #endif /* NG_SEPARATE_MALLOC */
  85
  86 /* Line discipline methods */
  87 static int      ng_h4_open      (struct cdev *, struct tty *);
  88 static int      ng_h4_close     (struct tty *, int);
  89 static int      ng_h4_read      (struct tty *, struct uio *, int);
  90 static int      ng_h4_write     (struct tty *, struct uio *, int);
  91 static int      ng_h4_input     (int, struct tty *);
  92 static int      ng_h4_start     (struct tty *);
  93 static int      ng_h4_ioctl     (struct tty *, u_long, caddr_t,
  94                                         int, struct thread *);
  95
  96 /* Line discipline descriptor */
  97 static struct linesw            ng_h4_disc = {
  98         ng_h4_open,             /* open */
  99         ng_h4_close,            /* close */
 100         ng_h4_read,             /* read */
 101         ng_h4_write,            /* write */
 102         ng_h4_ioctl,            /* ioctl */
 103         ng_h4_input,            /* input */
 104         ng_h4_start,            /* start */
 105         ttymodem                /* modem */
 106 };
 107
 108 /* Netgraph methods */
 109 static ng_constructor_t         ng_h4_constructor;
 110 static ng_rcvmsg_t              ng_h4_rcvmsg;
 111 static ng_shutdown_t            ng_h4_shutdown;
 112 static ng_newhook_t             ng_h4_newhook;
 113 static ng_connect_t             ng_h4_connect;
 114 static ng_rcvdata_t             ng_h4_rcvdata;
 115 static ng_disconnect_t          ng_h4_disconnect;
 116
 117 /* Other stuff */
 118 static void     ng_h4_process_timeout   (node_p, hook_p, void *, int);
 119 static int      ng_h4_mod_event         (module_t, int, void *);
 120
 121 /* Netgraph node type descriptor */
 122 static struct ng_type           typestruct = {
 123         .version =      NG_ABI_VERSION,
 124         .name =         NG_H4_NODE_TYPE,
 125         .mod_event =    ng_h4_mod_event,
 126         .constructor =  ng_h4_constructor,
 127         .rcvmsg =       ng_h4_rcvmsg,
 128         .shutdown =     ng_h4_shutdown,
 129         .newhook =      ng_h4_newhook,
 130         .connect =      ng_h4_connect,
 131         .rcvdata =      ng_h4_rcvdata,
 132         .disconnect =   ng_h4_disconnect,
 133         .cmdlist =      ng_h4_cmdlist
 134 };
 135 NETGRAPH_INIT(h4, &typestruct);
 136 MODULE_VERSION(ng_h4, NG_BLUETOOTH_VERSION);
 137
 138 static int      ng_h4_node = 0;
 139
 140 /*****************************************************************************
 141  *****************************************************************************
 142  **                         Line discipline methods
 143  *****************************************************************************
 144  *****************************************************************************/
 145
 146 /*
 147  * Set our line discipline on the tty.
 148  */
 149
 150 static int
 151 ng_h4_open(struct cdev *dev, struct tty *tp)
 152 {
 153         struct thread   *td = curthread;
 154         char             name[NG_NODESIZ];
 155         ng_h4_info_p     sc = NULL;
 156         int              error;
 157
 158         /* Super-user only */
 159         error = priv_check(td, PRIV_NETGRAPH_TTY); /* XXX */
 160         if (error != 0)
 161                 return (error);
 162
 163         /* Initialize private struct */
 164         MALLOC(sc, ng_h4_info_p, sizeof(*sc), M_NETGRAPH_H4, M_NOWAIT|M_ZERO);
 165         if (sc == NULL)
 166                 return (ENOMEM);
 167
 168         sc->tp = tp;
 169         sc->debug = NG_H4_WARN_LEVEL;
 170
 171         sc->state = NG_H4_W4_PKT_IND;
 172         sc->want = 1;
 173         sc->got = 0;
 174
 175         mtx_init(&sc->outq.ifq_mtx, "ng_h4 node+queue", NULL, MTX_DEF);
 176         IFQ_SET_MAXLEN(&sc->outq, NG_H4_DEFAULTQLEN);
 177         ng_callout_init(&sc->timo);
 178
 179         NG_H4_LOCK(sc);
 180
 181         /* Setup netgraph node */
 182         error = ng_make_node_common(&typestruct, &sc->node);
 183         if (error != 0) {
 184                 NG_H4_UNLOCK(sc);
 185
 186                 printf("%s: Unable to create new node!\n", __func__);
 187
 188                 mtx_destroy(&sc->outq.ifq_mtx);
 189                 bzero(sc, sizeof(*sc));
 190                 FREE(sc, M_NETGRAPH_H4);
 191
 192                 return (error);
 193         }
 194
 195         /* Assign node its name */
 196         snprintf(name, sizeof(name), "%s%d", typestruct.name, ng_h4_node ++);
 197
 198         error = ng_name_node(sc->node, name);
 199         if (error != 0) {
 200                 NG_H4_UNLOCK(sc);
 201
 202                 printf("%s: %s - node name exists?\n", __func__, name);
 203
 204                 NG_NODE_UNREF(sc->node);
 205                 mtx_destroy(&sc->outq.ifq_mtx);
 206                 bzero(sc, sizeof(*sc));
 207                 FREE(sc, M_NETGRAPH_H4);
 208
 209                 return (error);
 210         }
 211
 212         /* Set back pointers */
 213         NG_NODE_SET_PRIVATE(sc->node, sc);
 214         tp->t_lsc = (caddr_t) sc;
 215
 216         /* The node has to be a WRITER because data can change node status */
 217         NG_NODE_FORCE_WRITER(sc->node);
 218
 219         /*
 220          * Pre-allocate cblocks to the an appropriate amount.
 221          * I'm not sure what is appropriate.
 222          */
 223
 224         ttyflush(tp, FREAD | FWRITE);
 225         clist_alloc_cblocks(&tp->t_canq, 0, 0);
 226         clist_alloc_cblocks(&tp->t_rawq, 0, 0);
 227         clist_alloc_cblocks(&tp->t_outq,
 228                 MLEN + NG_H4_HIWATER, MLEN + NG_H4_HIWATER);
 229
 230         NG_H4_UNLOCK(sc);
 231
 232         return (error);
 233 } /* ng_h4_open */
 234
 235 /*
 236  * Line specific close routine, called from device close routine
 237  * and from ttioctl. This causes the node to be destroyed as well.
 238  */
 239
 240 static int
 241 ng_h4_close(struct tty *tp, int flag)
 242 {
 243         ng_h4_info_p    sc = (ng_h4_info_p) tp->t_lsc;
 244
 245         ttyflush(tp, FREAD | FWRITE);
 246         clist_free_cblocks(&tp->t_outq);
 247
 248         if (sc != NULL) {
 249                 NG_H4_LOCK(sc);
 250
 251                 if (callout_pending(&sc->timo))
 252                         ng_uncallout(&sc->timo, sc->node);
 253
 254                 tp->t_lsc = NULL;
 255                 sc->dying = 1;
 256
 257                 NG_H4_UNLOCK(sc);
 258
 259                 ng_rmnode_self(sc->node);
 260         }
 261
 262         return (0);
 263 } /* ng_h4_close */
 264
 265 /*
 266  * Once the device has been turned into a node, we don't allow reading.
 267  */
 268
 269 static int
 270 ng_h4_read(struct tty *tp, struct uio *uio, int flag)
 271 {
 272         return (EIO);
 273 } /* ng_h4_read */
 274
 275 /*
 276  * Once the device has been turned into a node, we don't allow writing.
 277  */
 278
 279 static int
 280 ng_h4_write(struct tty *tp, struct uio *uio, int flag)
 281 {
 282         return (EIO);
 283 } /* ng_h4_write */
 284
 285 /*
 286  * We implement the NGIOCGINFO ioctl() defined in ng_message.h.
 287  */
 288
 289 static int
 290 ng_h4_ioctl(struct tty *tp, u_long cmd, caddr_t data, int flag,
 291                 struct thread *td)
 292 {
 293         ng_h4_info_p    sc = (ng_h4_info_p) tp->t_lsc;
 294         int             error = 0;
 295
 296         if (sc == NULL)
 297                 return (ENXIO);
 298
 299         NG_H4_LOCK(sc);
 300
 301         switch (cmd) {
 302         case NGIOCGINFO:
 303 #undef  NI
 304 #define NI(x)   ((struct nodeinfo *)(x))
 305
 306                 bzero(data, sizeof(*NI(data)));
 307
 308                 if (NG_NODE_HAS_NAME(sc->node))
 309                         strncpy(NI(data)->name, NG_NODE_NAME(sc->node),
 310                                 sizeof(NI(data)->name) - 1);
 311
 312                 strncpy(NI(data)->type, sc->node->nd_type->name,
 313                         sizeof(NI(data)->type) - 1);
 314
 315                 NI(data)->id = (u_int32_t) ng_node2ID(sc->node);
 316                 NI(data)->hooks = NG_NODE_NUMHOOKS(sc->node);
 317                 break;
 318
 319         default:
 320                 error = ENOIOCTL;
 321                 break;
 322         }
 323
 324         NG_H4_UNLOCK(sc);
 325
 326         return (error);
 327 } /* ng_h4_ioctl */
 328
 329 /*
 330  * Receive data coming from the device. We get one character at a time, which
 331  * is kindof silly.
 332  */
 333
 334 static int
 335 ng_h4_input(int c, struct tty *tp)
 336 {
 337         ng_h4_info_p    sc = (ng_h4_info_p) tp->t_lsc;
 338
 339         if (sc == NULL || tp != sc->tp ||
 340             sc->node == NULL || NG_NODE_NOT_VALID(sc->node))
 341                 return (0);
 342
 343         NG_H4_LOCK(sc);
 344
 345         /* Check for error conditions */
 346         if ((tp->t_state & TS_CONNECTED) == 0) {
 347                 NG_H4_INFO("%s: %s - no carrier\n", __func__,
 348                         NG_NODE_NAME(sc->node));
 349
 350                 sc->state = NG_H4_W4_PKT_IND;
 351                 sc->want = 1;
 352                 sc->got = 0;
 353
 354                 NG_H4_UNLOCK(sc);
 355
 356                 return (0); /* XXX Loss of synchronization here! */
 357         }
 358
 359         /* Check for framing error or overrun on this char */
 360         if (c & TTY_ERRORMASK) {
 361                 NG_H4_ERR("%s: %s - line error %#x, c=%#x\n", __func__,
 362                         NG_NODE_NAME(sc->node), c & TTY_ERRORMASK,
 363                         c & TTY_CHARMASK);
 364
 365                 NG_H4_STAT_IERROR(sc->stat);
 366
 367                 sc->state = NG_H4_W4_PKT_IND;
 368                 sc->want = 1;
 369                 sc->got = 0;
 370
 371                 NG_H4_UNLOCK(sc);
 372
 373                 return (0); /* XXX Loss of synchronization here! */
 374         }
 375
 376         NG_H4_STAT_BYTES_RECV(sc->stat, 1);
 377
 378         /* Append char to mbuf */
 379         if (sc->got >= sizeof(sc->ibuf)) {
 380                 NG_H4_ALERT("%s: %s - input buffer overflow, c=%#x, got=%d\n",
 381                         __func__, NG_NODE_NAME(sc->node), c & TTY_CHARMASK,
 382                         sc->got);
 383
 384                 NG_H4_STAT_IERROR(sc->stat);
 385
 386                 sc->state = NG_H4_W4_PKT_IND;
 387                 sc->want = 1;
 388                 sc->got = 0;
 389
 390                 NG_H4_UNLOCK(sc);
 391
 392                 return (0); /* XXX Loss of synchronization here! */
 393         }
 394
 395         sc->ibuf[sc->got ++] = (c & TTY_CHARMASK);
 396
 397         NG_H4_INFO("%s: %s - got char %#x, want=%d, got=%d\n", __func__,
 398                 NG_NODE_NAME(sc->node), c, sc->want, sc->got);
 399
 400         if (sc->got < sc->want) {
 401                 NG_H4_UNLOCK(sc);
 402
 403                 return (0); /* Wait for more */
 404         }
 405
 406         switch (sc->state) {
 407         /* Got packet indicator */
 408         case NG_H4_W4_PKT_IND:
 409                 NG_H4_INFO("%s: %s - got packet indicator %#x\n", __func__,
 410                         NG_NODE_NAME(sc->node), sc->ibuf[0]);
 411
 412                 sc->state = NG_H4_W4_PKT_HDR;
 413
 414                 /*
 415                  * Since packet indicator included in the packet header
 416                  * just set sc->want to sizeof(packet header).
 417                  */
 418
 419                 switch (sc->ibuf[0]) {
 420                 case NG_HCI_ACL_DATA_PKT:
 421                         sc->want = sizeof(ng_hci_acldata_pkt_t);
 422                         break;
 423
 424                 case NG_HCI_SCO_DATA_PKT:
 425                         sc->want = sizeof(ng_hci_scodata_pkt_t);
 426                         break;
 427
 428                 case NG_HCI_EVENT_PKT:
 429                         sc->want = sizeof(ng_hci_event_pkt_t);
 430                         break;
 431
 432                 default:
 433                         NG_H4_WARN("%s: %s - ignoring unknown packet " \
 434                                 "type=%#x\n", __func__, NG_NODE_NAME(sc->node),
 435                                 sc->ibuf[0]);
 436
 437                         NG_H4_STAT_IERROR(sc->stat);
 438
 439                         sc->state = NG_H4_W4_PKT_IND;
 440                         sc->want = 1;
 441                         sc->got = 0;
 442                         break;
 443                 }
 444                 break;
 445
 446         /* Got packet header */
 447         case NG_H4_W4_PKT_HDR:
 448                 sc->state = NG_H4_W4_PKT_DATA;
 449
 450                 switch (sc->ibuf[0]) {
 451                 case NG_HCI_ACL_DATA_PKT:
 452                         c = le16toh(((ng_hci_acldata_pkt_t *)
 453                                 (sc->ibuf))->length);
 454                         break;
 455
 456                 case NG_HCI_SCO_DATA_PKT:
 457                         c = ((ng_hci_scodata_pkt_t *)(sc->ibuf))->length;
 458                         break;
 459
 460                 case NG_HCI_EVENT_PKT:
 461                         c = ((ng_hci_event_pkt_t *)(sc->ibuf))->length;
 462                         break;
 463
 464                 default:
 465                         KASSERT((0), ("Invalid packet type=%#x\n",
 466                                 sc->ibuf[0]));
 467                         break;
 468                 }
 469
 470                 NG_H4_INFO("%s: %s - got packet header, packet type=%#x, " \
 471                         "packet size=%d, payload size=%d\n", __func__,
 472                         NG_NODE_NAME(sc->node), sc->ibuf[0], sc->got, c);
 473
 474                 if (c > 0) {
 475                         sc->want += c;
 476
 477                         /*
 478                          * Try to prevent possible buffer overrun
 479                          *
 480                          * XXX I'm *really* confused here. It turns out
 481                          * that Xircom card sends us packets with length
 482                          * greater then 512 bytes! This is greater then
 483                          * our old receive buffer (ibuf) size. In the same
 484                          * time the card demands from us *not* to send
 485                          * packets greater then 192 bytes. Weird! How the
 486                          * hell i should know how big *receive* buffer
 487                          * should be? For now increase receiving buffer
 488                          * size to 1K and add the following check.
 489                          */
 490
 491                         if (sc->want >= sizeof(sc->ibuf)) {
 492                                 int     b;
 493
 494                                 NG_H4_ALERT("%s: %s - packet too big for " \
 495                                         "buffer, type=%#x, got=%d, want=%d, " \
 496                                         "length=%d\n", __func__,
 497                                         NG_NODE_NAME(sc->node), sc->ibuf[0],
 498                                         sc->got, sc->want, c);
 499
 500                                 NG_H4_ALERT("Packet header:\n");
 501                                 for (b = 0; b < sc->got; b++)
 502                                         NG_H4_ALERT("%#x ", sc->ibuf[b]);
 503                                 NG_H4_ALERT("\n");
 504
 505                                 /* Reset state */
 506                                 NG_H4_STAT_IERROR(sc->stat);
 507
 508                                 sc->state = NG_H4_W4_PKT_IND;
 509                                 sc->want = 1;
 510                                 sc->got = 0;
 511                         }
 512
 513                         break;
 514                 }
 515
 516                 /* else FALLTHROUGH and deliver frame */
 517                 /* XXX Is this true? Should we deliver empty frame? */
 518
 519         /* Got packet data */
 520         case NG_H4_W4_PKT_DATA:
 521                 NG_H4_INFO("%s: %s - got full packet, packet type=%#x, " \
 522                         "packet size=%d\n", __func__,
 523                         NG_NODE_NAME(sc->node), sc->ibuf[0], sc->got);
 524
 525                 if (sc->hook != NULL && NG_HOOK_IS_VALID(sc->hook)) {
 526                         struct mbuf     *m = NULL;
 527
 528                         MGETHDR(m, M_DONTWAIT, MT_DATA);
 529                         if (m != NULL) {
 530                                 m->m_pkthdr.len = 0;
 531
 532                                 /* XXX m_copyback() is stupid */
 533                                 m->m_len = min(MHLEN, sc->got);
 534
 535                                 m_copyback(m, 0, sc->got, sc->ibuf);
 536                                 NG_SEND_DATA_ONLY(c, sc->hook, m);
 537                         } else {
 538                                 NG_H4_ERR("%s: %s - could not get mbuf\n",
 539                                         __func__, NG_NODE_NAME(sc->node));
 540
 541                                 NG_H4_STAT_IERROR(sc->stat);
 542                         }
 543                 }
 544
 545                 sc->state = NG_H4_W4_PKT_IND;
 546                 sc->want = 1;
 547                 sc->got = 0;
 548
 549                 NG_H4_STAT_PCKTS_RECV(sc->stat);
 550                 break;
 551
 552         default:
 553                 KASSERT((0), ("Invalid H4 node state=%d", sc->state));
 554                 break;
 555         }
 556
 557         NG_H4_UNLOCK(sc);
 558
 559         return (0);
 560 } /* ng_h4_input */
 561
 562 /*
 563  * This is called when the device driver is ready for more output. Called from
 564  * tty system.
 565  */
 566
 567 static int
 568 ng_h4_start(struct tty *tp)
 569 {
 570         ng_h4_info_p     sc = (ng_h4_info_p) tp->t_lsc;
 571         struct mbuf     *m = NULL;
 572         int              size;
 573
 574         if (sc == NULL || tp != sc->tp ||
 575             sc->node == NULL || NG_NODE_NOT_VALID(sc->node))
 576                 return (0);
 577
 578 #if 0
 579         while (tp->t_outq.c_cc < NG_H4_HIWATER) { /* XXX 2.2 specific ? */
 580 #else
 581         while (1) {
 582 #endif
 583                 /* Remove first mbuf from queue */
 584                 IF_DEQUEUE(&sc->outq, m);
 585                 if (m == NULL)
 586                         break;
 587
 588                 /* Send as much of it as possible */
 589                 while (m != NULL) {
 590                         size = m->m_len - b_to_q(mtod(m, u_char *),
 591                                         m->m_len, &tp->t_outq);
 592
 593                         NG_H4_LOCK(sc);
 594                         NG_H4_STAT_BYTES_SENT(sc->stat, size);
 595                         NG_H4_UNLOCK(sc);
 596
 597                         m->m_data += size;
 598                         m->m_len -= size;
 599                         if (m->m_len > 0)
 600                                 break;  /* device can't take no more */
 601
 602                         m = m_free(m);
 603                 }
 604
 605                 /* Put remainder of mbuf chain (if any) back on queue */
 606                 if (m != NULL) {
 607                         IF_PREPEND(&sc->outq, m);
 608                         break;
 609                 }
 610
 611                 /* Full packet has been sent */
 612                 NG_H4_LOCK(sc);
 613                 NG_H4_STAT_PCKTS_SENT(sc->stat);
 614                 NG_H4_UNLOCK(sc);
 615         }
 616
 617         /*
 618          * Call output process whether or not there is any output. We are
 619          * being called in lieu of ttstart and must do what it would.
 620          */
 621
 622         tt_oproc(sc->tp);
 623
 624         /*
 625          * This timeout is needed for operation on a pseudo-tty, because the
 626          * pty code doesn't call pppstart after it has drained the t_outq.
 627          */
 628
 629         NG_H4_LOCK(sc);
 630
 631         if (!IFQ_IS_EMPTY(&sc->outq) && !callout_pending(&sc->timo))
 632                 ng_callout(&sc->timo, sc->node, NULL, 1,
 633                         ng_h4_process_timeout, NULL, 0);
 634
 635         NG_H4_UNLOCK(sc);
 636
 637         return (0);
 638 } /* ng_h4_start */
 639
 640 /*****************************************************************************
 641  *****************************************************************************
 642  **                         Netgraph node methods
 643  *****************************************************************************
 644  *****************************************************************************/
 645
 646 /*
 647  * Initialize a new node of this type. We only allow nodes to be created as
 648  * a result of setting the line discipline on a tty, so always return an error
 649  * if not.
 650  */
 651
 652 static int
 653 ng_h4_constructor(node_p node)
 654 {
 655         return (EOPNOTSUPP);
 656 } /* ng_h4_constructor */
 657
 658 /*
 659  * Add a new hook. There can only be one.
 660  */
 661
 662 static int
 663 ng_h4_newhook(node_p node, hook_p hook, const char *name)
 664 {
 665         ng_h4_info_p    sc = (ng_h4_info_p) NG_NODE_PRIVATE(node);
 666
 667         if (strcmp(name, NG_H4_HOOK) != 0)
 668                 return (EINVAL);
 669
 670         NG_H4_LOCK(sc);
 671
 672         if (sc->hook != NULL) {
 673                 NG_H4_UNLOCK(sc);
 674                 return (EISCONN);
 675         }
 676         sc->hook = hook;
 677
 678         NG_H4_UNLOCK(sc);
 679
 680         return (0);
 681 } /* ng_h4_newhook */
 682
 683 /*
 684  * Connect hook. Just say yes.
 685  */
 686
 687 static int
 688 ng_h4_connect(hook_p hook)
 689 {
 690         ng_h4_info_p    sc = (ng_h4_info_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 691
 692         if (hook != sc->hook)
 693                 panic("%s: hook != sc->hook\n", __func__);
 694
 695         NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));
 696         NG_HOOK_FORCE_QUEUE(hook);
 697
 698         return (0);
 699 } /* ng_h4_connect */
 700
 701 /*
 702  * Disconnect the hook
 703  */
 704
 705 static int
 706 ng_h4_disconnect(hook_p hook)
 707 {
 708         ng_h4_info_p    sc = (ng_h4_info_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 709
 710         /*
 711          * We need to check for sc != NULL because we can be called from
 712          * ng_h4_close() via ng_rmnode_self()
 713          */
 714
 715         if (sc != NULL) {
 716                 if (hook != sc->hook)
 717                         panic("%s: hook != sc->hook\n", __func__);
 718
 719                 NG_H4_LOCK(sc);
 720
 721                 /* XXX do we have to untimeout and drain out queue? */
 722                 if (callout_pending(&sc->timo))
 723                         ng_uncallout(&sc->timo, sc->node);
 724
 725                 _IF_DRAIN(&sc->outq);
 726
 727                 sc->state = NG_H4_W4_PKT_IND;
 728                 sc->want = 1;
 729                 sc->got = 0;
 730
 731                 sc->hook = NULL;
 732
 733                 NG_H4_UNLOCK(sc);
 734         }
 735
 736         return (0);
 737 } /* ng_h4_disconnect */
 738
 739 /*
 740  * Remove this node. The does the netgraph portion of the shutdown.
 741  * This should only be called indirectly from ng_h4_close().
 742  */
 743
 744 static int
 745 ng_h4_shutdown(node_p node)
 746 {
 747         ng_h4_info_p    sc = (ng_h4_info_p) NG_NODE_PRIVATE(node);
 748
 749         NG_H4_LOCK(sc);
 750
 751         if (!sc->dying) {
 752                 NG_H4_UNLOCK(sc);
 753
 754                 NG_NODE_REVIVE(node);   /* we will persist */
 755
 756                 return (EOPNOTSUPP);
 757         }
 758
 759         NG_H4_UNLOCK(sc);
 760
 761         NG_NODE_SET_PRIVATE(node, NULL);
 762
 763         _IF_DRAIN(&sc->outq);
 764
 765         NG_NODE_UNREF(node);
 766         mtx_destroy(&sc->outq.ifq_mtx);
 767         bzero(sc, sizeof(*sc));
 768         FREE(sc, M_NETGRAPH_H4);
 769
 770         return (0);
 771 } /* ng_h4_shutdown */
 772
 773 /*
 774  * Receive incoming data from Netgraph system. Put it on our
 775  * output queue and start output if necessary.
 776  */
 777
 778 static int
 779 ng_h4_rcvdata(hook_p hook, item_p item)
 780 {
 781         ng_h4_info_p     sc = (ng_h4_info_p)NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 782         struct mbuf     *m = NULL;
 783         int              qlen;
 784
 785         if (sc == NULL)
 786                 return (EHOSTDOWN);
 787
 788         if (hook != sc->hook)
 789                 panic("%s: hook != sc->hook\n", __func__);
 790
 791         NGI_GET_M(item, m);
 792         NG_FREE_ITEM(item);
 793
 794         NG_H4_LOCK(sc);
 795
 796         if (_IF_QFULL(&sc->outq)) {
 797                 NG_H4_ERR("%s: %s - dropping mbuf, len=%d\n", __func__,
 798                         NG_NODE_NAME(sc->node), m->m_pkthdr.len);
 799
 800                 NG_H4_STAT_OERROR(sc->stat);
 801                 _IF_DROP(&sc->outq);
 802
 803                 NG_H4_UNLOCK(sc);
 804
 805                 NG_FREE_M(m);
 806
 807                 return (ENOBUFS);
 808         }
 809
 810         NG_H4_INFO("%s: %s - queue mbuf, len=%d\n", __func__,
 811                 NG_NODE_NAME(sc->node), m->m_pkthdr.len);
 812
 813         _IF_ENQUEUE(&sc->outq, m);
 814         qlen = _IF_QLEN(&sc->outq);
 815
 816         NG_H4_UNLOCK(sc);
 817
 818         /*
 819          * If qlen > 1, then we should already have a scheduled callout
 820          */
 821
 822         if (qlen == 1) {
 823                 mtx_lock(&Giant);
 824                 ng_h4_start(sc->tp);
 825                 mtx_unlock(&Giant);
 826         }
 827
 828         return (0);
 829 } /* ng_h4_rcvdata */
 830
 831 /*
 832  * Receive control message
 833  */
 834
 835 static int
 836 ng_h4_rcvmsg(node_p node, item_p item, hook_p lasthook)
 837 {
 838         ng_h4_info_p     sc = (ng_h4_info_p) NG_NODE_PRIVATE(node);
 839         struct ng_mesg  *msg = NULL, *resp = NULL;
 840         int              error = 0;
 841
 842         if (sc == NULL)
 843                 return (EHOSTDOWN);
 844
 845         NGI_GET_MSG(item, msg);
 846         NG_H4_LOCK(sc);
 847
 848         switch (msg->header.typecookie) {
 849         case NGM_GENERIC_COOKIE:
 850                 switch (msg->header.cmd) {
 851                 case NGM_TEXT_STATUS:
 852                         NG_MKRESPONSE(resp, msg, NG_TEXTRESPONSE, M_NOWAIT);
 853                         if (resp == NULL)
 854                                 error = ENOMEM;
 855                         else
 856                                 snprintf(resp->data, NG_TEXTRESPONSE,
 857                                         "Hook: %s\n"   \
 858                                         "Debug: %d\n"  \
 859                                         "State: %d\n"  \
 860                                         "Queue: [have:%d,max:%d]\n" \
 861                                         "Input: [got:%d,want:%d]",
 862                                         (sc->hook != NULL)? NG_H4_HOOK : "",
 863                                         sc->debug,
 864                                         sc->state,
 865                                         _IF_QLEN(&sc->outq),
 866                                         sc->outq.ifq_maxlen,
 867                                         sc->got,
 868                                         sc->want);
 869                         break;
 870
 871                 default:
 872                         error = EINVAL;
 873                         break;
 874                 }
 875                 break;
 876
 877         case NGM_H4_COOKIE:
 878                 switch (msg->header.cmd) {
 879                 case NGM_H4_NODE_RESET:
 880                         _IF_DRAIN(&sc->outq);
 881                         sc->state = NG_H4_W4_PKT_IND;
 882                         sc->want = 1;
 883                         sc->got = 0;
 884                         break;
 885
 886                 case NGM_H4_NODE_GET_STATE:
 887                         NG_MKRESPONSE(resp, msg, sizeof(ng_h4_node_state_ep),
 888                                 M_NOWAIT);
 889                         if (resp == NULL)
 890                                 error = ENOMEM;
 891                         else
 892                                 *((ng_h4_node_state_ep *)(resp->data)) =
 893                                         sc->state;
 894                         break;
 895
 896                 case NGM_H4_NODE_GET_DEBUG:
 897                         NG_MKRESPONSE(resp, msg, sizeof(ng_h4_node_debug_ep),
 898                                 M_NOWAIT);
 899                         if (resp == NULL)
 900                                 error = ENOMEM;
 901                         else
 902                                 *((ng_h4_node_debug_ep *)(resp->data)) =
 903                                         sc->debug;
 904                         break;
 905
 906                 case NGM_H4_NODE_SET_DEBUG:
 907                         if (msg->header.arglen != sizeof(ng_h4_node_debug_ep))
 908                                 error = EMSGSIZE;
 909                         else
 910                                 sc->debug =
 911                                         *((ng_h4_node_debug_ep *)(msg->data));
 912                         break;
 913
 914                 case NGM_H4_NODE_GET_QLEN:
 915                         NG_MKRESPONSE(resp, msg, sizeof(ng_h4_node_qlen_ep),
 916                                 M_NOWAIT);
 917                         if (resp == NULL)
 918                                 error = ENOMEM;
 919                         else
 920                                 *((ng_h4_node_qlen_ep *)(resp->data)) =
 921                                         sc->outq.ifq_maxlen;
 922                         break;
 923
 924                 case NGM_H4_NODE_SET_QLEN:
 925                         if (msg->header.arglen != sizeof(ng_h4_node_qlen_ep))
 926                                 error = EMSGSIZE;
 927                         else if (*((ng_h4_node_qlen_ep *)(msg->data)) <= 0)
 928                                 error = EINVAL;
 929                         else
 930                                 IFQ_SET_MAXLEN(&sc->outq,
 931                                         *((ng_h4_node_qlen_ep *)(msg->data)));
 932                         break;
 933
 934                 case NGM_H4_NODE_GET_STAT:
 935                         NG_MKRESPONSE(resp, msg, sizeof(ng_h4_node_stat_ep),
 936                                 M_NOWAIT);
 937                         if (resp == NULL)
 938                                 error = ENOMEM;
 939                         else
 940                                 bcopy(&sc->stat, resp->data,
 941                                         sizeof(ng_h4_node_stat_ep));
 942                         break;
 943
 944                 case NGM_H4_NODE_RESET_STAT:
 945                         NG_H4_STAT_RESET(sc->stat);
 946                         break;
 947
 948                 default:
 949                         error = EINVAL;
 950                         break;
 951                 }
 952                 break;
 953
 954         default:
 955                 error = EINVAL;
 956                 break;
 957         }
 958
 959         NG_H4_UNLOCK(sc);
 960
 961         NG_RESPOND_MSG(error, node, item, resp);
 962         NG_FREE_MSG(msg);
 963
 964         return (error);
 965 } /* ng_h4_rcvmsg */
 966
 967 /*
 968  * Timeout processing function.
 969  * We still have data to output to the device, so try sending more.
 970  */
 971
 972 static void
 973 ng_h4_process_timeout(node_p node, hook_p hook, void *arg1, int arg2)
 974 {
 975         ng_h4_info_p    sc = (ng_h4_info_p) NG_NODE_PRIVATE(node);
 976
 977         mtx_lock(&Giant);
 978         ng_h4_start(sc->tp);
 979         mtx_unlock(&Giant);
 980 } /* ng_h4_process_timeout */
 981
 982 /*
 983  * Handle loading and unloading for this node type
 984  */
 985
 986 static int
 987 ng_h4_mod_event(module_t mod, int event, void *data)
 988 {
 989         static int      ng_h4_ldisc;
 990         int             error = 0;
 991
 992         switch (event) {
 993         case MOD_LOAD:
 994                 /* Register line discipline */
 995                 mtx_lock(&Giant);
 996                 ng_h4_ldisc = ldisc_register(H4DISC, &ng_h4_disc);
 997                 mtx_unlock(&Giant);
 998
 999                 if (ng_h4_ldisc < 0) {
1000                         printf("%s: can't register H4 line discipline\n",
1001                                 __func__);
1002                         error = EIO;
1003                 }
1004                 break;
1005
1006         case MOD_UNLOAD:
1007                 /* Unregister line discipline */
1008                 mtx_lock(&Giant);
1009                 ldisc_deregister(ng_h4_ldisc);
1010                 mtx_unlock(&Giant);
1011                 break;
1012
1013         default:
1014                 error = EOPNOTSUPP;
1015                 break;
1016         }
1017
1018         return (error);
1019 } /* ng_h4_mod_event */
1020