sys/netgraph/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  * $FreeBSD$
  31  *
  32  */
  33
  34 #if 0
  35 #define DBG do { printf("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/ioccom.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 <netgraph/ng_message.h>
  60 #include <netgraph/netgraph.h>
  61 #include <netgraph/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         priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
 167
 168         /* Allocate unit number */
 169         priv->unit = alloc_unr(ngd_unit);
 170
 171         /* Initialize mutexes and queue */
 172         mtx_init(&priv->ngd_mtx, "ng_device", NULL, MTX_DEF);
 173         mtx_init(&priv->readq.ifq_mtx, "ng_device queue", NULL, MTX_DEF);
 174         IFQ_SET_MAXLEN(&priv->readq, ifqmaxlen);
 175
 176         /* Link everything together */
 177         NG_NODE_SET_PRIVATE(node, priv);
 178         priv->node = node;
 179
 180         priv->ngddev = make_dev(&ngd_cdevsw, priv->unit, UID_ROOT,
 181             GID_WHEEL, 0600, NG_DEVICE_DEVNAME "%d", priv->unit);
 182         if(priv->ngddev == NULL) {
 183                 printf("%s(): make_dev() failed\n",__func__);
 184                 mtx_destroy(&priv->ngd_mtx);
 185                 mtx_destroy(&priv->readq.ifq_mtx);
 186                 free_unr(ngd_unit, priv->unit);
 187                 free(priv, M_NETGRAPH);
 188                 return(EINVAL);
 189         }
 190         /* XXX: race here? */
 191         priv->ngddev->si_drv1 = priv;
 192
 193         return(0);
 194 }
 195
 196 /*
 197  * Process control message.
 198  */
 199
 200 static int
 201 ng_device_rcvmsg(node_p node, item_p item, hook_p lasthook)
 202 {
 203         const priv_p priv = NG_NODE_PRIVATE(node);
 204         struct ng_mesg *msg;
 205         struct ng_mesg *resp = NULL;
 206         const char *dn;
 207         int error = 0;
 208
 209         NGI_GET_MSG(item, msg);
 210
 211         if (msg->header.typecookie == NGM_DEVICE_COOKIE) {
 212                 switch (msg->header.cmd) {
 213                 case NGM_DEVICE_GET_DEVNAME:
 214                         /* XXX: Fix when MAX_NGD us bigger */
 215                         NG_MKRESPONSE(resp, msg,
 216                             strlen(NG_DEVICE_DEVNAME) + 4, M_NOWAIT);
 217
 218                         if (resp == NULL)
 219                                 ERROUT(ENOMEM);
 220
 221                         dn = devtoname(priv->ngddev);
 222                         strlcpy((char *)resp->data, dn, strlen(dn) + 1);
 223                         break;
 224
 225                 default:
 226                         error = EINVAL;
 227                         break;
 228                 }
 229         } else
 230                 error = EINVAL;
 231
 232 done:
 233         NG_RESPOND_MSG(error, node, item, resp);
 234         NG_FREE_MSG(msg);
 235         return (error);
 236 }
 237
 238 /*
 239  * Accept incoming hook. We support only one hook per node.
 240  */
 241 static int
 242 ng_device_newhook(node_p node, hook_p hook, const char *name)
 243 {
 244         priv_p priv = NG_NODE_PRIVATE(node);
 245
 246         DBG;
 247
 248         /* We have only one hook per node */
 249         if (priv->hook != NULL)
 250                 return (EISCONN);
 251
 252         priv->hook = hook;
 253
 254         return(0);
 255 }
 256
 257 /*
 258  * Receive data from hook, write it to device.
 259  */
 260 static int
 261 ng_device_rcvdata(hook_p hook, item_p item)
 262 {
 263         priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 264         struct mbuf *m;
 265
 266         DBG;
 267
 268         NGI_GET_M(item, m);
 269         NG_FREE_ITEM(item);
 270
 271         IF_LOCK(&priv->readq);
 272         if (_IF_QFULL(&priv->readq)) {
 273                 IF_UNLOCK(&priv->readq);
 274                 NG_FREE_M(m);
 275                 return (ENOBUFS);
 276         }
 277
 278         _IF_ENQUEUE(&priv->readq, m);
 279         IF_UNLOCK(&priv->readq);
 280         mtx_lock(&priv->ngd_mtx);
 281         if (priv->flags & NGDF_RWAIT) {
 282                 priv->flags &= ~NGDF_RWAIT;
 283                 wakeup(priv);
 284         }
 285         mtx_unlock(&priv->ngd_mtx);
 286
 287         return(0);
 288 }
 289
 290 /*
 291  * Removal of the hook destroys the node.
 292  */
 293 static int
 294 ng_device_disconnect(hook_p hook)
 295 {
 296         priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 297
 298         DBG;
 299
 300         destroy_dev(priv->ngddev);
 301         mtx_destroy(&priv->ngd_mtx);
 302
 303         IF_DRAIN(&priv->readq);
 304         mtx_destroy(&(priv)->readq.ifq_mtx);
 305
 306         free_unr(ngd_unit, priv->unit);
 307
 308         free(priv, M_NETGRAPH);
 309
 310         ng_rmnode_self(NG_HOOK_NODE(hook));
 311
 312         return(0);
 313 }
 314
 315 /*
 316  * Node shutdown. Everything is already done in disconnect method.
 317  */
 318 static int
 319 ng_device_shutdown(node_p node)
 320 {
 321         NG_NODE_UNREF(node);
 322         return (0);
 323 }
 324
 325 /******************************************************************************
 326  *  Device methods
 327  ******************************************************************************/
 328
 329 /*
 330  * the device is opened
 331  */
 332 static int
 333 ngdopen(struct cdev *dev, int flag, int mode, struct thread *td)
 334 {
 335         priv_p  priv = (priv_p )dev->si_drv1;
 336
 337         DBG;
 338
 339         mtx_lock(&priv->ngd_mtx);
 340         priv->flags |= NGDF_OPEN;
 341         mtx_unlock(&priv->ngd_mtx);
 342
 343         return(0);
 344 }
 345
 346 /*
 347  * the device is closed
 348  */
 349 static int
 350 ngdclose(struct cdev *dev, int flag, int mode, struct thread *td)
 351 {
 352         priv_p  priv = (priv_p )dev->si_drv1;
 353
 354         DBG;
 355         mtx_lock(&priv->ngd_mtx);
 356         priv->flags &= ~NGDF_OPEN;
 357         mtx_unlock(&priv->ngd_mtx);
 358
 359         return(0);
 360 }
 361
 362 #if 0   /*
 363          * The ioctl is transformed into netgraph control message.
 364          * We do not process them, yet.
 365          */
 366 /*
 367  * process ioctl
 368  *
 369  * they are translated into netgraph messages and passed on
 370  *
 371  */
 372 static int
 373 ngdioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
 374 {
 375         struct ngd_softc *sc = &ngd_softc;
 376         struct ngd_connection * connection = NULL;
 377         struct ngd_connection * tmp;
 378         int error = 0;
 379         struct ng_mesg *msg;
 380         struct ngd_param_s * datap;
 381
 382         DBG;
 383
 384         NG_MKMESSAGE(msg, NGM_DEVICE_COOKIE, cmd, sizeof(struct ngd_param_s),
 385                         M_NOWAIT);
 386         if (msg == NULL) {
 387                 printf("%s(): msg == NULL\n",__func__);
 388                 goto nomsg;
 389         }
 390
 391         /* pass the ioctl data into the ->data area */
 392         datap = (struct ngd_param_s *)msg->data;
 393         datap->p = addr;
 394
 395         NG_SEND_MSG_HOOK(error, sc->node, msg, connection->active_hook, 0);
 396         if(error)
 397                 printf("%s(): NG_SEND_MSG_HOOK error: %d\n",__func__,error);
 398
 399 nomsg:
 400
 401         return(0);
 402 }
 403 #endif /* if 0 */
 404
 405 /*
 406  * This function is called when a read(2) is done to our device.
 407  * We process one mbuf from queue.
 408  */
 409 static int
 410 ngdread(struct cdev *dev, struct uio *uio, int flag)
 411 {
 412         priv_p  priv = (priv_p )dev->si_drv1;
 413         struct mbuf *m;
 414         int len, error = 0;
 415
 416         DBG;
 417
 418         /* get an mbuf */
 419         do {
 420                 IF_DEQUEUE(&priv->readq, m);
 421                 if (m == NULL) {
 422                         if (flag & IO_NDELAY)
 423                                 return (EWOULDBLOCK);
 424                         mtx_lock(&priv->ngd_mtx);
 425                         priv->flags |= NGDF_RWAIT;
 426                         if ((error = msleep(priv, &priv->ngd_mtx,
 427                             PDROP | PCATCH | (PZERO + 1),
 428                             "ngdread", 0)) != 0)
 429                                 return (error);
 430                 }
 431         } while (m == NULL);
 432
 433         while (m && uio->uio_resid > 0 && error == 0) {
 434                 len = MIN(uio->uio_resid, m->m_len);
 435                 if (len != 0)
 436                         error = uiomove(mtod(m, void *), len, uio);
 437                 m = m_free(m);
 438         }
 439
 440         if (m)
 441                 m_freem(m);
 442
 443         return (error);
 444 }
 445
 446
 447 /*
 448  * This function is called when our device is written to.
 449  * We read the data from userland into mbuf chain and pass it to the remote hook.
 450  *
 451  */
 452 static int
 453 ngdwrite(struct cdev *dev, struct uio *uio, int flag)
 454 {
 455         priv_p  priv = (priv_p )dev->si_drv1;
 456         struct mbuf *m;
 457         int error = 0;
 458
 459         DBG;
 460
 461         if (uio->uio_resid == 0)
 462                 return (0);
 463
 464         if (uio->uio_resid < 0 || uio->uio_resid > IP_MAXPACKET)
 465                 return (EIO);
 466
 467         if ((m = m_uiotombuf(uio, M_NOWAIT, 0, 0, M_PKTHDR)) == NULL)
 468                 return (ENOBUFS);
 469
 470         NG_SEND_DATA_ONLY(error, priv->hook, m);
 471
 472         return (error);
 473 }
 474
 475 /*
 476  * we are being polled/selected
 477  * check if there is data available for read
 478  */
 479 static int
 480 ngdpoll(struct cdev *dev, int events, struct thread *td)
 481 {
 482         priv_p  priv = (priv_p )dev->si_drv1;
 483         int revents = 0;
 484
 485         if (events & (POLLIN | POLLRDNORM) &&
 486             !IFQ_IS_EMPTY(&priv->readq))
 487                 revents |= events & (POLLIN | POLLRDNORM);
 488
 489         return (revents);
 490 }