sys/netgraph7/ng_device.c

   1 /*-
   2  * Copyright (c) 2002 Mark Santcroos <marks@ripe.net>
   3  * Copyright (c) 2004-2005 Gleb Smirnoff <glebius@FreeBSD.org>
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  *
  25  * Netgraph "device" node
  26  *
  27  * This node presents a /dev/ngd%d device that interfaces to an other
  28  * netgraph node.
  29  *
  30  * $FreeBSD: src/sys/netgraph/ng_device.c,v 1.22 2006/11/02 17:37:21 andre Exp $
  31  * $DragonFly: src/sys/netgraph7/ng_device.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
  32  *
  33  */
  34
  35 #if 0
  36 #define DBG do { printf("ng_device: %s\n", __func__ ); } while (0)
  37 #else
  38 #define DBG do {} while (0)
  39 #endif
  40
  41 #include <sys/param.h>
  42 #include <sys/conf.h>
  43 #include <sys/ioccom.h>
  44 #include <sys/kernel.h>
  45 #include <sys/malloc.h>
  46 #include <sys/mbuf.h>
  47 #include <sys/poll.h>
  48 #include <sys/queue.h>
  49 #include <sys/socket.h>
  50 #include <sys/systm.h>
  51 #include <sys/uio.h>
  52 #include <sys/vnode.h>
  53
  54 #include <net/if.h>
  55 #include <net/if_var.h>
  56 #include <netinet/in.h>
  57 #include <netinet/in_systm.h>
  58 #include <netinet/ip.h>
  59
  60 #include "ng_message.h"
  61 #include "netgraph.h"
  62 #include "ng_device.h"
  63
  64 #define ERROUT(x) do { error = (x); goto done; } while (0)
  65
  66 /* Netgraph methods */
  67 static int              ng_device_mod_event(module_t, int, void *);
  68 static ng_constructor_t ng_device_constructor;
  69 static ng_rcvmsg_t      ng_device_rcvmsg;
  70 static ng_shutdown_t    ng_device_shutdown;
  71 static ng_newhook_t     ng_device_newhook;
  72 static ng_rcvdata_t     ng_device_rcvdata;
  73 static ng_disconnect_t  ng_device_disconnect;
  74
  75 /* Netgraph type */
  76 static struct ng_type ngd_typestruct = {
  77         .version =      NG_ABI_VERSION,
  78         .name =         NG_DEVICE_NODE_TYPE,
  79         .mod_event =    ng_device_mod_event,
  80         .constructor =  ng_device_constructor,
  81         .rcvmsg =       ng_device_rcvmsg,
  82         .shutdown =     ng_device_shutdown,
  83         .newhook =      ng_device_newhook,
  84         .rcvdata =      ng_device_rcvdata,
  85         .disconnect =   ng_device_disconnect,
  86 };
  87 NETGRAPH_INIT(device, &ngd_typestruct);
  88
  89 /* per node data */
  90 struct ngd_private {
  91         struct  ifqueue readq;
  92         struct  ng_node *node;
  93         struct  ng_hook *hook;
  94         struct  cdev    *ngddev;
  95         struct  mtx     ngd_mtx;
  96         int             unit;
  97         uint16_t        flags;
  98 #define NGDF_OPEN       0x0001
  99 #define NGDF_RWAIT      0x0002
 100 };
 101 typedef struct ngd_private *priv_p;
 102
 103 /* unit number allocator entity */
 104 static struct unrhdr *ngd_unit;
 105
 106 /* Maximum number of NGD devices */
 107 #define MAX_NGD 999
 108
 109 static d_close_t ngdclose;
 110 static d_open_t ngdopen;
 111 static d_read_t ngdread;
 112 static d_write_t ngdwrite;
 113 #if 0
 114 static d_ioctl_t ngdioctl;
 115 #endif
 116 static d_poll_t ngdpoll;
 117
 118 static struct cdevsw ngd_cdevsw = {
 119         .d_version =    D_VERSION,
 120         .d_open =       ngdopen,
 121         .d_close =      ngdclose,
 122         .d_read =       ngdread,
 123         .d_write =      ngdwrite,
 124 #if 0
 125         .d_ioctl =      ngdioctl,
 126 #endif
 127         .d_poll =       ngdpoll,
 128         .d_name =       NG_DEVICE_DEVNAME,
 129 };
 130
 131 /******************************************************************************
 132  *  Netgraph methods
 133  ******************************************************************************/
 134
 135 /*
 136  * Handle loading and unloading for this node type.
 137  */
 138 static int
 139 ng_device_mod_event(module_t mod, int event, void *data)
 140 {
 141         int error = 0;
 142
 143         switch (event) {
 144         case MOD_LOAD:
 145                 ngd_unit = new_unrhdr(0, MAX_NGD, NULL);
 146                 break;
 147         case MOD_UNLOAD:
 148                 delete_unrhdr(ngd_unit);
 149                 break;
 150         default:
 151                 error = EOPNOTSUPP;
 152                 break;
 153         }
 154         return (error);
 155 }
 156
 157 /*
 158  * create new node
 159  */
 160 static int
 161 ng_device_constructor(node_p node)
 162 {
 163         priv_p  priv;
 164
 165         DBG;
 166
 167         MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
 168         if (priv == NULL)
 169                 return (ENOMEM);
 170
 171         /* Allocate unit number */
 172         priv->unit = alloc_unr(ngd_unit);
 173
 174         /* Initialize mutexes and queue */
 175         mtx_init(&priv->ngd_mtx, "ng_device", NULL, MTX_DEF);
 176         mtx_init(&priv->readq.ifq_mtx, "ng_device queue", NULL, MTX_DEF);
 177         IFQ_SET_MAXLEN(&priv->readq, ifqmaxlen);
 178
 179         /* Link everything together */
 180         NG_NODE_SET_PRIVATE(node, priv);
 181         priv->node = node;
 182
 183         priv->ngddev = make_dev(&ngd_cdevsw, unit2minor(priv->unit), UID_ROOT,
 184             GID_WHEEL, 0600, NG_DEVICE_DEVNAME "%d", priv->unit);
 185         if(priv->ngddev == NULL) {
 186                 printf("%s(): make_dev() failed\n",__func__);
 187                 mtx_destroy(&priv->ngd_mtx);
 188                 mtx_destroy(&priv->readq.ifq_mtx);
 189                 free_unr(ngd_unit, priv->unit);
 190                 FREE(priv, M_NETGRAPH);
 191                 return(EINVAL);
 192         }
 193         /* XXX: race here? */
 194         priv->ngddev->si_drv1 = priv;
 195
 196         return(0);
 197 }
 198
 199 /*
 200  * Process control message.
 201  */
 202
 203 static int
 204 ng_device_rcvmsg(node_p node, item_p item, hook_p lasthook)
 205 {
 206         const priv_p priv = NG_NODE_PRIVATE(node);
 207         struct ng_mesg *msg;
 208         struct ng_mesg *resp = NULL;
 209         int error = 0;
 210
 211         NGI_GET_MSG(item, msg);
 212
 213         if (msg->header.typecookie == NGM_DEVICE_COOKIE) {
 214                 switch (msg->header.cmd) {
 215                 case NGM_DEVICE_GET_DEVNAME:
 216                         /* XXX: Fix when MAX_NGD us bigger */
 217                         NG_MKRESPONSE(resp, msg,
 218                             strlen(NG_DEVICE_DEVNAME) + 4, M_WAITOK);
 219
 220                         if (resp == NULL)
 221                                 ERROUT(ENOMEM);
 222
 223                         strlcpy((char *)resp->data, priv->ngddev->si_name,
 224                             strlen(priv->ngddev->si_name) + 1);
 225                         break;
 226
 227                 default:
 228                         error = EINVAL;
 229                         break;
 230                 }
 231         } else
 232                 error = EINVAL;
 233
 234 done:
 235         NG_RESPOND_MSG(error, node, item, resp);
 236         NG_FREE_MSG(msg);
 237         return (error);
 238 }
 239
 240 /*
 241  * Accept incoming hook. We support only one hook per node.
 242  */
 243 static int
 244 ng_device_newhook(node_p node, hook_p hook, const char *name)
 245 {
 246         priv_p priv = NG_NODE_PRIVATE(node);
 247
 248         DBG;
 249
 250         /* We have only one hook per node */
 251         if (priv->hook != NULL)
 252                 return (EISCONN);
 253
 254         priv->hook = hook;
 255
 256         return(0);
 257 }
 258
 259 /*
 260  * Receive data from hook, write it to device.
 261  */
 262 static int
 263 ng_device_rcvdata(hook_p hook, item_p item)
 264 {
 265         priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 266         struct mbuf *m;
 267
 268         DBG;
 269
 270         NGI_GET_M(item, m);
 271         NG_FREE_ITEM(item);
 272
 273         IF_LOCK(&priv->readq);
 274         if (_IF_QFULL(&priv->readq)) {
 275                 _IF_DROP(&priv->readq);
 276                 IF_UNLOCK(&priv->readq);
 277                 NG_FREE_M(m);
 278                 return (ENOBUFS);
 279         }
 280
 281         _IF_ENQUEUE(&priv->readq, m);
 282         IF_UNLOCK(&priv->readq);
 283         mtx_lock(&priv->ngd_mtx);
 284         if (priv->flags & NGDF_RWAIT) {
 285                 priv->flags &= ~NGDF_RWAIT;
 286                 wakeup(priv);
 287         }
 288         mtx_unlock(&priv->ngd_mtx);
 289
 290         return(0);
 291 }
 292
 293 /*
 294  * Removal of the hook destroys the node.
 295  */
 296 static int
 297 ng_device_disconnect(hook_p hook)
 298 {
 299         priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 300
 301         DBG;
 302
 303         destroy_dev(priv->ngddev);
 304         mtx_destroy(&priv->ngd_mtx);
 305
 306         IF_DRAIN(&priv->readq);
 307         mtx_destroy(&(priv)->readq.ifq_mtx);
 308
 309         free_unr(ngd_unit, priv->unit);
 310
 311         FREE(priv, M_NETGRAPH);
 312
 313         ng_rmnode_self(NG_HOOK_NODE(hook));
 314
 315         return(0);
 316 }
 317
 318 /*
 319  * Node shutdown. Everything is already done in disconnect method.
 320  */
 321 static int
 322 ng_device_shutdown(node_p node)
 323 {
 324         NG_NODE_UNREF(node);
 325         return (0);
 326 }
 327
 328 /******************************************************************************
 329  *  Device methods
 330  ******************************************************************************/
 331
 332 /*
 333  * the device is opened
 334  */
 335 static int
 336 ngdopen(struct cdev *dev, int flag, int mode, struct thread *td)
 337 {
 338         priv_p  priv = (priv_p )dev->si_drv1;
 339
 340         DBG;
 341
 342         mtx_lock(&priv->ngd_mtx);
 343         priv->flags |= NGDF_OPEN;
 344         mtx_unlock(&priv->ngd_mtx);
 345
 346         return(0);
 347 }
 348
 349 /*
 350  * the device is closed
 351  */
 352 static int
 353 ngdclose(struct cdev *dev, int flag, int mode, struct thread *td)
 354 {
 355         priv_p  priv = (priv_p )dev->si_drv1;
 356
 357         DBG;
 358         mtx_lock(&priv->ngd_mtx);
 359         priv->flags &= ~NGDF_OPEN;
 360         mtx_unlock(&priv->ngd_mtx);
 361
 362         return(0);
 363 }
 364
 365 #if 0   /*
 366          * The ioctl is transformed into netgraph control message.
 367          * We do not process them, yet.
 368          */
 369 /*
 370  * process ioctl
 371  *
 372  * they are translated into netgraph messages and passed on
 373  *
 374  */
 375 static int
 376 ngdioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
 377 {
 378         struct ngd_softc *sc = &ngd_softc;
 379         struct ngd_connection * connection = NULL;
 380         struct ngd_connection * tmp;
 381         int error = 0;
 382         struct ng_mesg *msg;
 383         struct ngd_param_s * datap;
 384
 385         DBG;
 386
 387         NG_MKMESSAGE(msg, NGM_DEVICE_COOKIE, cmd, sizeof(struct ngd_param_s),
 388                         M_WAITOK);
 389         if (msg == NULL) {
 390                 printf("%s(): msg == NULL\n",__func__);
 391                 goto nomsg;
 392         }
 393
 394         /* pass the ioctl data into the ->data area */
 395         datap = (struct ngd_param_s *)msg->data;
 396         datap->p = addr;
 397
 398         NG_SEND_MSG_HOOK(error, sc->node, msg, connection->active_hook, 0);
 399         if(error)
 400                 printf("%s(): NG_SEND_MSG_HOOK error: %d\n",__func__,error);
 401
 402 nomsg:
 403
 404         return(0);
 405 }
 406 #endif /* if 0 */
 407
 408 /*
 409  * This function is called when a read(2) is done to our device.
 410  * We process one mbuf from queue.
 411  */
 412 static int
 413 ngdread(struct cdev *dev, struct uio *uio, int flag)
 414 {
 415         priv_p  priv = (priv_p )dev->si_drv1;
 416         struct mbuf *m;
 417         int len, error = 0;
 418
 419         DBG;
 420
 421         /* get an mbuf */
 422         do {
 423                 IF_DEQUEUE(&priv->readq, m);
 424                 if (m == NULL) {
 425                         if (flag & IO_NDELAY)
 426                                 return (EWOULDBLOCK);
 427                         mtx_lock(&priv->ngd_mtx);
 428                         priv->flags |= NGDF_RWAIT;
 429                         if ((error = msleep(priv, &priv->ngd_mtx,
 430                             PDROP | PCATCH | (PZERO + 1),
 431                             "ngdread", 0)) != 0)
 432                                 return (error);
 433                 }
 434         } while (m == NULL);
 435
 436         while (m && uio->uio_resid > 0 && error == 0) {
 437                 len = MIN(uio->uio_resid, m->m_len);
 438                 if (len != 0)
 439                         error = uiomove(mtod(m, void *), len, uio);
 440                 m = m_free(m);
 441         }
 442
 443         if (m)
 444                 m_freem(m);
 445
 446         return (error);
 447 }
 448
 449
 450 /*
 451  * This function is called when our device is written to.
 452  * We read the data from userland into mbuf chain and pass it to the remote hook.
 453  *
 454  */
 455 static int
 456 ngdwrite(struct cdev *dev, struct uio *uio, int flag)
 457 {
 458         priv_p  priv = (priv_p )dev->si_drv1;
 459         struct mbuf *m;
 460         int error = 0;
 461
 462         DBG;
 463
 464         if (uio->uio_resid == 0)
 465                 return (0);
 466
 467         if (uio->uio_resid < 0 || uio->uio_resid > IP_MAXPACKET)
 468                 return (EIO);
 469
 470         if ((m = m_uiotombuf(uio, MB_DONTWAIT, 0, 0, M_PKTHDR)) == NULL)
 471                 return (ENOBUFS);
 472
 473         NG_SEND_DATA_ONLY(error, priv->hook, m);
 474
 475         return (error);
 476 }
 477
 478 /*
 479  * we are being polled/selected
 480  * check if there is data available for read
 481  */
 482 static int
 483 ngdpoll(struct cdev *dev, int events, struct thread *td)
 484 {
 485         priv_p  priv = (priv_p )dev->si_drv1;
 486         int revents = 0;
 487
 488         if (events & (POLLIN | POLLRDNORM) &&
 489             !IFQ_IS_EMPTY(&priv->readq))
 490                 revents |= events & (POLLIN | POLLRDNORM);
 491
 492         return (revents);
 493 }