sys/netgraph/ng_device.c

   1 /*
   2  * Copyright (c) 2002 Mark Santcroos <marks@ripe.net>
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  * 3. The name of the author may not be used to endorse or promote products
  13  *    derived from this software without specific prior written permission.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * Netgraph "device" node
  27  *
  28  * This node presents a /dev/ngd%d device that interfaces to an other
  29  * netgraph node.
  30  *
  31  * $FreeBSD: src/sys/netgraph/ng_device.c,v 1.1.2.1 2002/08/23 07:15:44 julian Exp $
  32  * $DragonFly: src/sys/netgraph/ng_device.c,v 1.11 2007/06/03 20:51:10 dillon Exp $
  33  *
  34  */
  35
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/kernel.h>
  39 #include <sys/mbuf.h>
  40 #include <sys/uio.h>
  41 #include <sys/queue.h>
  42 #include <sys/malloc.h>
  43 #include <sys/conf.h>
  44 #include <sys/poll.h>
  45
  46 #include <netgraph/ng_message.h>
  47 #include <netgraph/netgraph.h>
  48
  49 #include "ng_device.h"
  50
  51 /* turn this on for verbose messages */
  52 #define NGD_DEBUG
  53
  54 /* Netgraph methods */
  55 static ng_constructor_t ng_device_cons;
  56 static ng_rcvmsg_t      ng_device_rcvmsg;
  57 static ng_newhook_t     ng_device_newhook;
  58 static ng_connect_t     ng_device_connect;
  59 static ng_rcvdata_t     ng_device_rcvdata;
  60 static ng_disconnect_t  ng_device_disconnect;
  61 static int              ng_device_mod_event(module_t mod, int event, void *data);
  62
  63 static int ng_device_init(void);
  64 static int get_free_unit(void);
  65
  66 /* Netgraph type */
  67 static struct ng_type typestruct = {
  68         NG_VERSION,                     /* version */
  69         NG_DEVICE_NODE_TYPE,            /* name */
  70         ng_device_mod_event,            /* modevent */
  71         ng_device_cons,                 /* constructor */
  72         ng_device_rcvmsg,               /* receive msg */
  73         NULL,                           /* shutdown */
  74         ng_device_newhook,              /* newhook */
  75         NULL,                           /* findhook */
  76         ng_device_connect,              /* connect */
  77         ng_device_rcvdata,              /* receive data */
  78         ng_device_rcvdata,              /* receive queued data */
  79         ng_device_disconnect,           /* disconnect */
  80         NULL
  81 };
  82 NETGRAPH_INIT(device, &typestruct);
  83
  84 /* per hook data */
  85 struct ngd_connection {
  86         SLIST_ENTRY(ngd_connection) links;
  87
  88         cdev_t  ngddev;
  89         struct  ng_hook *active_hook;
  90         char    *readq;
  91         int     loc;
  92         int     unit;
  93 };
  94
  95 /* global data */
  96 struct ngd_softc {
  97         SLIST_HEAD(, ngd_connection) head;
  98
  99         node_p node;
 100         char nodename[NG_NODESIZ];
 101 } ngd_softc;
 102
 103 /* helper definition */
 104 #define         MIN(a, b)       ((a) < (b) ? (a) : (b))
 105
 106 /* the per connection receiving queue maximum */
 107 #define NGD_QUEUE_SIZE (1024*10)
 108
 109 /* Maximum number of NGD devices */
 110 #define MAX_NGD 25              /* should be more than enough for now */
 111
 112 static d_close_t ngdclose;
 113 static d_open_t ngdopen;
 114 static d_read_t ngdread;
 115 static d_write_t ngdwrite;
 116 static d_ioctl_t ngdioctl;
 117 static d_poll_t ngdpoll;
 118
 119 #define NGD_CDEV_MAJOR 20
 120 static struct cdevsw ngd_cdevsw = {
 121         /* name */      "ngd",
 122         /* maj */       NGD_CDEV_MAJOR,
 123         /* flags */     0,
 124         /* port */      NULL,
 125         /* clone */     NULL,
 126
 127         /* open */      ngdopen,
 128         /* close */     ngdclose,
 129         /* read */      ngdread,
 130         /* write */     ngdwrite,
 131         /* ioctl */     ngdioctl,
 132         /* poll */      ngdpoll,
 133         /* mmap */      nommap,
 134         /* strategy */  nostrategy,
 135         /* dump */      nodump,
 136         /* psize */     nopsize
 137 };
 138
 139 /*
 140  * this holds all the stuff that should be done at load time
 141  */
 142 static int
 143 ng_device_mod_event(module_t mod, int event, void *data)
 144 {
 145         int error = 0;
 146
 147 #ifdef NGD_DEBUG
 148         kprintf("%s()\n", __func__);
 149 #endif /* NGD_DEBUG */
 150
 151         switch (event) {
 152                 case MOD_LOAD:
 153                         cdevsw_add(&ngd_cdevsw, 0, 0);
 154                         ng_device_init();
 155                         break;
 156
 157                 case MOD_UNLOAD:
 158                         /* XXX do we need to do something specific ? */
 159                         /* ng_device_breakdown */
 160                         cdevsw_remove(&ngd_cdevsw, 0, 0);
 161                         error = EBUSY; /* no unload! */
 162                         break;
 163
 164
 165                 default:
 166                         error = EOPNOTSUPP;
 167                         break;
 168         }
 169
 170         return(error);
 171 }
 172
 173
 174 static int
 175 ng_device_init(void)
 176 {
 177         struct ngd_softc *sc = &ngd_softc;
 178
 179 #ifdef NGD_DEBUG
 180         kprintf("%s()\n", __func__);
 181 #endif /* NGD_DEBUG */
 182
 183         SLIST_INIT(&sc->head);
 184
 185         if (ng_make_node_common(&typestruct, &sc->node) != 0) {
 186                 kprintf("%s(): ng_make_node_common failed\n", __func__);
 187                 return(ENXIO);
 188         }
 189         ksprintf(sc->nodename, "%s", NG_DEVICE_NODE_TYPE);
 190         if (ng_name_node(sc->node, sc->nodename)) {
 191                 NG_NODE_UNREF(sc->node); /* make it go away again */
 192                 kprintf("%s(): ng_name_node failed\n", __func__);
 193                 return(ENXIO);
 194         }
 195         NG_NODE_SET_PRIVATE(sc->node, sc);
 196
 197         return(0);
 198 }
 199
 200 /*
 201  * don't allow to be created, only the device can do that
 202  */
 203 static int
 204 ng_device_cons(node_p node)
 205 {
 206
 207 #ifdef NGD_DEBUG
 208         kprintf("%s()\n", __func__);
 209 #endif /* NGD_DEBUG */
 210
 211         return(EINVAL);
 212 }
 213
 214 /*
 215  * Receive control message. We just  free it.
 216  */
 217 static int
 218 ng_device_rcvmsg(node_p node,
 219         struct ng_mesg *msg, const char *retaddr, struct ng_mesg **rptr)
 220 {
 221         FREE(msg, M_NETGRAPH);
 222         return(ENOTTY);
 223 }
 224
 225 static int
 226 get_free_unit(void)
 227 {
 228         struct ngd_connection *tmp = NULL;
 229         struct ngd_softc *sc = &ngd_softc;
 230         int n = 0;
 231         int unit = -1;
 232
 233 #ifdef NGD_DEBUG
 234         kprintf("%s()\n", __func__);
 235 #endif /* NGD_DEBUG */
 236
 237         /* When there is no list yet, the first device unit is always 0. */
 238         if SLIST_EMPTY(&sc->head) {
 239                 unit = 0;
 240                 return(unit);
 241         }
 242
 243         /* Just do a brute force loop to find the first free unit that is
 244          * smaller than MAX_NGD.
 245          * Set MAX_NGD to a large value, doesn't impact performance.
 246          */
 247         for(n = 0;n<MAX_NGD && unit == -1;n++) {
 248                 SLIST_FOREACH(tmp, &sc->head, links) {
 249
 250                         if(tmp->unit == n) {
 251                                 unit = -1;
 252                                 break;
 253                         }
 254                         unit = n;
 255                 }
 256         }
 257
 258         return(unit);
 259 }
 260
 261 /*
 262  * incoming hook
 263  */
 264 static int
 265 ng_device_newhook(node_p node, hook_p hook, const char *name)
 266 {
 267         struct ngd_softc *sc = &ngd_softc;
 268         struct ngd_connection * new_connection = NULL;
 269
 270 #ifdef NGD_DEBUG
 271         kprintf("%s()\n", __func__);
 272 #endif /* NGD_DEBUG */
 273
 274         new_connection = kmalloc(sizeof(struct ngd_connection), M_DEVBUF, M_NOWAIT);
 275         if(new_connection == NULL) {
 276                 kprintf("%s(): ERROR: new_connection == NULL\n", __func__);
 277                 return(-1);
 278         }
 279
 280         new_connection->unit = get_free_unit();
 281         if(new_connection->unit<0) {
 282                 kprintf("%s: No free unit found by get_free_unit(), "
 283                                 "increas MAX_NGD\n", __func__);
 284                 kfree(new_connection, M_DEVBUF);
 285                 return(-1);
 286         }
 287         new_connection->ngddev = make_dev(&ngd_cdevsw,
 288             new_connection->unit, 0, 0, 0600, "ngd%d", new_connection->unit);
 289         if(new_connection->ngddev == NULL) {
 290                 kprintf("%s(): make_dev failed\n", __func__);
 291                 SLIST_REMOVE(&sc->head, new_connection, ngd_connection, links);
 292                 kfree(new_connection, M_DEVBUF);
 293                 return(-1);
 294         }
 295
 296         new_connection->readq =
 297             kmalloc(sizeof(char)*NGD_QUEUE_SIZE, M_DEVBUF, M_NOWAIT | M_ZERO);
 298         if(new_connection->readq == NULL) {
 299                 kprintf("%s(): readq malloc failed\n", __func__);
 300                 destroy_dev(new_connection->ngddev);
 301                 SLIST_REMOVE(&sc->head, new_connection, ngd_connection, links);
 302                 kfree(new_connection, M_DEVBUF);
 303                 return(-1);
 304         }
 305
 306         /* point to begin of buffer */
 307         new_connection->loc = 0;
 308         new_connection->active_hook = hook;
 309
 310         SLIST_INSERT_HEAD(&sc->head, new_connection, links);
 311
 312         return(0);
 313 }
 314
 315 /*
 316  * we gave ok to a new hook
 317  * now connect
 318  */
 319 static int
 320 ng_device_connect(hook_p hook)
 321 {
 322
 323 #ifdef NGD_DEBUG
 324         kprintf("%s()\n", __func__);
 325 #endif /* NGD_DEBUG */
 326
 327         return(0);
 328 }
 329
 330
 331 /*
 332  * Receive data from hook
 333  */
 334 static int
 335 ng_device_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
 336 {
 337         struct ngd_softc *sc = &ngd_softc;
 338         struct ngd_connection * connection = NULL;
 339         struct ngd_connection * tmp;
 340         char *buffer;
 341
 342 #ifdef NGD_DEBUG
 343         kprintf("%s()\n", __func__);
 344 #endif /* NGD_DEBUG */
 345
 346         SLIST_FOREACH(tmp, &sc->head, links) {
 347                 if(tmp->active_hook == hook) {
 348                         connection = tmp;
 349                 }
 350         }
 351         if(connection == NULL) {
 352                 kprintf("%s(): connection still NULL, no hook found\n", __func__);
 353                 return(-1);
 354         }
 355
 356         NG_FREE_META(meta);
 357
 358         m = m_pullup(m, m->m_len);
 359         if(m == NULL) {
 360                 kprintf("%s(): ERROR: m_pullup failed\n", __func__);
 361                 return(-1);
 362         }
 363
 364         buffer = kmalloc(sizeof(char)*m->m_len, M_DEVBUF, M_NOWAIT | M_ZERO);
 365         if(buffer == NULL) {
 366                 kprintf("%s(): ERROR: buffer malloc failed\n", __func__);
 367                 return(-1);
 368         }
 369
 370         buffer = mtod(m, char *);
 371
 372         if( (connection->loc+m->m_len) < NGD_QUEUE_SIZE) {
 373                 memcpy(connection->readq+connection->loc, buffer, m->m_len);
 374                 connection->loc += m->m_len;
 375         } else
 376                 kprintf("%s(): queue full, first read out a bit\n", __func__);
 377
 378         kfree(buffer, M_DEVBUF);
 379
 380         return(0);
 381 }
 382
 383 /*
 384  * Removal of the last link destroys the node
 385  */
 386 static int
 387 ng_device_disconnect(hook_p hook)
 388 {
 389         struct ngd_softc *sc = &ngd_softc;
 390         struct ngd_connection * connection = NULL;
 391         struct ngd_connection * tmp;
 392
 393 #ifdef NGD_DEBUG
 394         kprintf("%s()\n", __func__);
 395 #endif /* NGD_DEBUG */
 396
 397         SLIST_FOREACH(tmp, &sc->head, links) {
 398                 if(tmp->active_hook == hook) {
 399                         connection = tmp;
 400                 }
 401         }
 402         if(connection == NULL) {
 403                 kprintf("%s(): connection still NULL, no hook found\n",
 404                     __func__);
 405                 return(-1);
 406         }
 407
 408         kfree(connection->readq, M_DEVBUF);
 409
 410         destroy_dev(connection->ngddev);
 411
 412         SLIST_REMOVE(&sc->head, connection, ngd_connection, links);
 413
 414         return(0);
 415 }
 416 /*
 417  * the device is opened
 418  */
 419 static int
 420 ngdopen(cdev_t dev, int flag, int mode, struct thread *td)
 421 {
 422
 423 #ifdef NGD_DEBUG
 424         kprintf("%s()\n", __func__);
 425 #endif /* NGD_DEBUG */
 426
 427         return(0);
 428 }
 429
 430 /*
 431  * the device is closed
 432  */
 433 static int
 434 ngdclose(cdev_t dev, int flag, int mode, struct thread *td)
 435 {
 436
 437 #ifdef NGD_DEBUG
 438         kprintf("%s()\n", __func__);
 439 #endif
 440
 441         return(0);
 442 }
 443
 444
 445 /*
 446  * process ioctl
 447  *
 448  * they are translated into netgraph messages and passed on
 449  *
 450  */
 451 static int
 452 ngdioctl(cdev_t dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
 453 {
 454         struct ngd_softc *sc = &ngd_softc;
 455         struct ngd_connection * connection = NULL;
 456         struct ngd_connection * tmp;
 457         int error = 0;
 458         struct ng_mesg *msg;
 459         struct ngd_param_s * datap;
 460
 461 #ifdef NGD_DEBUG
 462         kprintf("%s()\n", __func__);
 463 #endif /* NGD_DEBUG */
 464
 465         SLIST_FOREACH(tmp, &sc->head, links) {
 466                 if(tmp->ngddev == dev) {
 467                         connection = tmp;
 468                 }
 469         }
 470         if(connection == NULL) {
 471                 kprintf("%s(): connection still NULL, no dev found\n",
 472                     __func__);
 473                 return(-1);
 474         }
 475
 476         /* NG_MKMESSAGE(msg, cookie, cmdid, len, how) */
 477         NG_MKMESSAGE(msg, NGM_DEVICE_COOKIE, cmd, sizeof(struct ngd_param_s),
 478                         M_NOWAIT);
 479         if (msg == NULL) {
 480                 kprintf("%s(): msg == NULL\n", __func__);
 481                 goto nomsg;
 482         }
 483
 484         /* pass the ioctl data into the ->data area */
 485         datap = (struct ngd_param_s *)msg->data;
 486         datap->p = addr;
 487
 488         /*ng_send_msg(node_p here, struct ng_mesg *msg,
 489                     const char *address, struct ng_mesg **resp); */
 490         error = ng_send_msg(sc->node, msg,
 491             NG_HOOK_NAME(connection->active_hook), NULL);
 492         if(error)
 493                 kprintf("%s(): ng_send_msg() error: %d\n", __func__, error);
 494
 495 nomsg:
 496
 497         return(0);
 498 }
 499
 500
 501 /*
 502  * This function is called when a read(2) is done to our device.
 503  * We pass the data available in kernelspace on into userland using
 504  * uiomove.
 505  */
 506 static int
 507 ngdread(cdev_t dev, struct uio *uio, int flag)
 508 {
 509         int ret = 0, amnt;
 510         char buffer[uio->uio_resid+1];
 511         struct ngd_softc *sc = &ngd_softc;
 512         struct ngd_connection * connection = NULL;
 513         struct ngd_connection * tmp;
 514
 515 #ifdef NGD_DEBUG
 516         kprintf("%s()\n", __func__);
 517 #endif /* NGD_DEBUG */
 518
 519         SLIST_FOREACH(tmp, &sc->head, links) {
 520                 if(tmp->ngddev == dev) {
 521                         connection = tmp;
 522                 }
 523         }
 524         if(connection == NULL) {
 525                 kprintf("%s(): connection still NULL, no dev found\n", __func__);
 526                 return(-1);
 527         }
 528
 529         while ( ( uio->uio_resid > 0 ) && ( connection->loc > 0 ) ) {
 530                 amnt = MIN(uio->uio_resid, connection->loc);
 531
 532                 memcpy(buffer, connection->readq, amnt);
 533                 memcpy(connection->readq, connection->readq+amnt,
 534                                 connection->loc-amnt);
 535                 connection->loc -= amnt;
 536
 537                 ret = uiomove((caddr_t)buffer, amnt, uio);
 538                 if(ret != 0)
 539                         goto error;
 540
 541         }
 542         return(0);
 543
 544 error:
 545         kprintf("%s(): uiomove returns error %d\n", __func__, ret);
 546         /* do error cleanup here */
 547         return(ret);
 548 }
 549
 550
 551 /*
 552  * This function is called when our device is written to.
 553  * We read the data from userland into our local buffer and pass it on
 554  * into the remote hook.
 555  *
 556  */
 557 static int
 558 ngdwrite(cdev_t dev, struct uio *uio, int flag)
 559 {
 560         int ret;
 561         int error = 0;
 562         struct mbuf *m;
 563         char buffer[uio->uio_resid];
 564         int len = uio->uio_resid;
 565         struct ngd_softc *sc =& ngd_softc;
 566         struct ngd_connection * connection = NULL;
 567         struct ngd_connection * tmp;
 568
 569 #ifdef NGD_DEBUG
 570         kprintf("%s()\n", __func__);
 571 #endif /* NGD_DEBUG */
 572
 573         SLIST_FOREACH(tmp, &sc->head, links) {
 574                 if(tmp->ngddev == dev) {
 575                         connection = tmp;
 576                 }
 577         }
 578
 579         if(connection == NULL) {
 580                 kprintf("%s(): connection still NULL, no dev found\n", __func__);
 581                 return(-1);
 582         }
 583
 584         if (len > 0) {
 585                 if ((ret = uiomove((caddr_t)buffer, len, uio)) != 0)
 586                         goto error;
 587         } else
 588                 kprintf("%s(): len <= 0 : supposed to happen?!\n", __func__);
 589
 590         m = m_devget(buffer, len, 0, NULL, NULL);
 591
 592         NG_SEND_DATA_ONLY(error, connection->active_hook, m);
 593
 594         return(0);
 595
 596 error:
 597         /* do error cleanup here */
 598         kprintf("%s(): uiomove returned err: %d\n", __func__, ret);
 599
 600         return(ret);
 601 }
 602
 603 /*
 604  * we are being polled/selected
 605  * check if there is data available for read
 606  */
 607 static int
 608 ngdpoll(cdev_t dev, int events, struct thread *td)
 609 {
 610         int revents = 0;
 611         struct ngd_softc *sc = &ngd_softc;
 612         struct ngd_connection * connection = NULL;
 613         struct ngd_connection * tmp;
 614
 615
 616         if (events & (POLLIN | POLLRDNORM)) {
 617                 /* get the connection we have to know the loc from */
 618                 SLIST_FOREACH(tmp, &sc->head, links) {
 619                         if(tmp->ngddev == dev) {
 620                                 connection = tmp;
 621                         }
 622                 }
 623                 if(connection == NULL) {
 624                         kprintf("%s(): ERROR: connection still NULL, "
 625                                 "no dev found\n", __func__);
 626                         return(-1);
 627                 }
 628
 629                 if (connection->loc > 0)
 630                         revents |= events & (POLLIN | POLLRDNORM);
 631         }
 632
 633         return(revents);
 634 }