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