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