ng_device.c revision 126080
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: head/sys/netgraph/ng_device.c 126080 2004-02-21 21:10:55Z phk $ 32 * 33 */ 34 35#include <sys/param.h> 36#include <sys/systm.h> 37#include <sys/kernel.h> 38#include <sys/mbuf.h> 39#include <sys/uio.h> 40#include <sys/queue.h> 41#include <sys/malloc.h> 42#include <sys/conf.h> 43#include <sys/poll.h> 44#include <sys/ioccom.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 */ 55static ng_constructor_t ng_device_cons; 56static ng_rcvmsg_t ng_device_rcvmsg; 57static ng_newhook_t ng_device_newhook; 58static ng_connect_t ng_device_connect; 59static ng_rcvdata_t ng_device_rcvdata; 60static ng_disconnect_t ng_device_disconnect; 61static int ng_device_mod_event(module_t mod, int event, void *data); 62 63static int ng_device_init(void); 64static int get_free_unit(void); 65 66/* Netgraph type */ 67static struct ng_type typestruct = { 68 NG_ABI_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_disconnect, /* disconnect */ 79 NULL 80}; 81NETGRAPH_INIT(device, &typestruct); 82 83/* per hook data */ 84struct ngd_connection { 85 SLIST_ENTRY(ngd_connection) links; 86 87 dev_t ngddev; 88 struct ng_hook *active_hook; 89 char *readq; 90 int loc; 91 int unit; 92}; 93 94/* global data */ 95struct ngd_softc { 96 SLIST_HEAD(, ngd_connection) head; 97 98 node_p node; 99 char nodename[NG_NODESIZ]; 100} ngd_softc; 101 102/* the per connection receiving queue maximum */ 103#define NGD_QUEUE_SIZE (1024*10) 104 105/* Maximum number of NGD devices */ 106#define MAX_NGD 25 /* should be more than enough for now */ 107 108static d_close_t ngdclose; 109static d_open_t ngdopen; 110static d_read_t ngdread; 111static d_write_t ngdwrite; 112static d_ioctl_t ngdioctl; 113static d_poll_t ngdpoll; 114 115static struct cdevsw ngd_cdevsw = { 116 .d_version = D_VERSION, 117 .d_flags = D_NEEDGIANT, 118 .d_open = ngdopen, 119 .d_close = ngdclose, 120 .d_read = ngdread, 121 .d_write = ngdwrite, 122 .d_ioctl = ngdioctl, 123 .d_poll = ngdpoll, 124 .d_name = "ngd", 125}; 126 127/* 128 * this holds all the stuff that should be done at load time 129 */ 130static int 131ng_device_mod_event(module_t mod, int event, void *data) 132{ 133 int error = 0; 134 135#ifdef NGD_DEBUG 136 printf("%s()\n",__func__); 137#endif /* NGD_DEBUG */ 138 139 switch (event) { 140 case MOD_LOAD: 141 142 ng_device_init(); 143 break; 144 145 case MOD_UNLOAD: 146 /* XXX do we need to do something specific ? */ 147 /* ng_device_breakdown */ 148 break; 149 150 default: 151 error = EOPNOTSUPP; 152 break; 153 } 154 155 return(error); 156} 157 158 159static int 160ng_device_init() 161{ 162 struct ngd_softc *sc = &ngd_softc; 163 164#ifdef NGD_DEBUG 165 printf("%s()\n",__func__); 166#endif /* NGD_DEBUG */ 167 168 SLIST_INIT(&sc->head); 169 170 if (ng_make_node_common(&typestruct, &sc->node) != 0) { 171 printf("%s(): ng_make_node_common failed\n",__func__); 172 return(ENXIO); 173 } 174 sprintf(sc->nodename, "%s", NG_DEVICE_NODE_TYPE); 175 if (ng_name_node(sc->node, sc->nodename)) { 176 NG_NODE_UNREF(sc->node); /* make it go away again */ 177 printf("%s(): ng_name_node failed\n",__func__); 178 return(ENXIO); 179 } 180 NG_NODE_SET_PRIVATE(sc->node, sc); 181 182 return(0); 183} 184 185/* 186 * don't allow to be created, only the device can do that 187 */ 188static int 189ng_device_cons(node_p node) 190{ 191 192#ifdef NGD_DEBUG 193 printf("%s()\n",__func__); 194#endif /* NGD_DEBUG */ 195 196 return(EINVAL); 197} 198 199/* 200 * Receive control message. We just bounce it back as a reply. 201 */ 202static int 203ng_device_rcvmsg(node_p node, item_p item, hook_p lasthook) 204{ 205 struct ngd_softc *sc = &ngd_softc; 206 struct ng_mesg *msg; 207 int error = 0; 208 struct ngd_connection * connection = NULL; 209 struct ngd_connection *tmp = NULL; 210 211#ifdef NGD_DEBUG 212 printf("%s()\n",__func__); 213#endif /* NGD_DEBUG */ 214 215 NGI_GET_MSG(item, msg); 216 217 SLIST_FOREACH(tmp,&sc->head,links) { 218 if(tmp->active_hook == lasthook) { 219 connection = tmp; 220 } 221 } 222 if(connection == NULL) { 223 printf("%s(): connection is still NULL, no hook found\n",__func__); 224 return(-1); 225 } 226 227 return(error); 228} 229 230static int 231get_free_unit() 232{ 233 struct ngd_connection *tmp = NULL; 234 struct ngd_softc *sc = &ngd_softc; 235 int n = 0; 236 int unit = -1; 237 238#ifdef NGD_DEBUG 239 printf("%s()\n",__func__); 240#endif /* NGD_DEBUG */ 241 242 /* When there is no list yet, the first device unit is always 0. */ 243 if SLIST_EMPTY(&sc->head) { 244 unit = 0; 245 return(unit); 246 } 247 248 /* Just do a brute force loop to find the first free unit that is 249 * smaller than MAX_NGD. 250 * Set MAX_NGD to a large value, doesn't impact performance. 251 */ 252 for(n = 0;n<MAX_NGD && unit == -1;n++) { 253 SLIST_FOREACH(tmp,&sc->head,links) { 254 255 if(tmp->unit == n) { 256 unit = -1; 257 break; 258 } 259 unit = n; 260 } 261 } 262 263 return(unit); 264} 265 266/* 267 * incoming hook 268 */ 269static int 270ng_device_newhook(node_p node, hook_p hook, const char *name) 271{ 272 struct ngd_softc *sc = &ngd_softc; 273 struct ngd_connection * new_connection = NULL; 274 275#ifdef NGD_DEBUG 276 printf("%s()\n",__func__); 277#endif /* NGD_DEBUG */ 278 279 new_connection = malloc(sizeof(struct ngd_connection), M_DEVBUF, M_NOWAIT); 280 if(new_connection == NULL) { 281 printf("%s(): ERROR: new_connection == NULL\n",__func__); 282 return(-1); 283 } 284 285 new_connection->unit = get_free_unit(); 286 if(new_connection->unit<0) { 287 printf("%s: No free unit found by get_free_unit(), " 288 "increas MAX_NGD\n",__func__); 289 return(-1); 290 } 291 new_connection->ngddev = make_dev(&ngd_cdevsw, new_connection->unit, 0, 0,0600,"ngd%d",new_connection->unit); 292 if(new_connection->ngddev == NULL) { 293 printf("%s(): make_dev failed\n",__func__); 294 return(-1); 295 } 296 297 new_connection->readq = malloc(sizeof(char)*NGD_QUEUE_SIZE, M_DEVBUF, M_NOWAIT | M_ZERO); 298 if(new_connection->readq == NULL) { 299 printf("%s(): readq malloc failed\n",__func__); 300 return(-1); 301 } 302 303 /* point to begin of buffer */ 304 new_connection->loc = 0; 305 new_connection->active_hook = hook; 306 307 SLIST_INSERT_HEAD(&sc->head, new_connection, links); 308 309 return(0); 310} 311 312/* 313 * we gave ok to a new hook 314 * now connect 315 */ 316static int 317ng_device_connect(hook_p hook) 318{ 319 320#ifdef NGD_DEBUG 321 printf("%s()\n",__func__); 322#endif /* NGD_DEBUG */ 323 324 return(0); 325} 326 327 328/* 329 * Receive data from hook 330 */ 331static int 332ng_device_rcvdata(hook_p hook, item_p item) 333{ 334 struct mbuf *m; 335 struct ngd_softc *sc = &ngd_softc; 336 struct ngd_connection * connection = NULL; 337 struct ngd_connection * tmp; 338 char *buffer; 339 340#ifdef NGD_DEBUG 341 printf("%s()\n",__func__); 342#endif /* NGD_DEBUG */ 343 344 SLIST_FOREACH(tmp,&sc->head,links) { 345 if(tmp->active_hook == hook) { 346 connection = tmp; 347 } 348 } 349 if(connection == NULL) { 350 printf("%s(): connection is still NULL, no hook found\n",__func__); 351 return(-1); 352 } 353 354 NGI_GET_M(item, m); 355 NG_FREE_ITEM(item); 356 357 m = m_pullup(m,m->m_len); 358 if(m == NULL) { 359 printf("%s(): ERROR: m_pullup failed\n",__func__); 360 return(-1); 361 } 362 363 buffer = malloc(sizeof(char)*m->m_len, M_DEVBUF, M_NOWAIT | M_ZERO); 364 if(buffer == NULL) { 365 printf("%s(): ERROR: buffer malloc failed\n",__func__); 366 return(-1); 367 } 368 369 buffer = mtod(m,char *); 370 371 if( (connection->loc+m->m_len) < NGD_QUEUE_SIZE) { 372 memcpy(connection->readq+connection->loc, buffer, m->m_len); 373 connection->loc += m->m_len; 374 } else 375 printf("%s(): queue full, first read out a bit\n",__func__); 376 377 free(buffer,M_DEVBUF); 378 379 return(0); 380} 381 382/* 383 * Removal of the last link destroys the node 384 */ 385static int 386ng_device_disconnect(hook_p hook) 387{ 388 struct ngd_softc *sc = &ngd_softc; 389 struct ngd_connection * connection = NULL; 390 struct ngd_connection * tmp; 391 392#ifdef NGD_DEBUG 393 printf("%s()\n",__func__); 394#endif /* NGD_DEBUG */ 395 396 SLIST_FOREACH(tmp,&sc->head,links) { 397 if(tmp->active_hook == hook) { 398 connection = tmp; 399 } 400 } 401 if(connection == NULL) { 402 printf("%s(): connection is still NULL, no hook found\n",__func__); 403 return(-1); 404 } 405 406 free(connection->readq,M_DEVBUF); 407 408 destroy_dev(connection->ngddev); 409 410 SLIST_REMOVE(&sc->head,connection,ngd_connection,links); 411 412 return(0); 413} 414/* 415 * the device is opened 416 */ 417static int 418ngdopen(dev_t dev, int flag, int mode, struct thread *td) 419{ 420 421#ifdef NGD_DEBUG 422 printf("%s()\n",__func__); 423#endif /* NGD_DEBUG */ 424 425 return(0); 426} 427 428/* 429 * the device is closed 430 */ 431static int 432ngdclose(dev_t dev, int flag, int mode, struct thread *td) 433{ 434 435#ifdef NGD_DEBUG 436 printf("%s()\n",__func__); 437#endif 438 439 return(0); 440} 441 442 443/* 444 * process ioctl 445 * 446 * they are translated into netgraph messages and passed on 447 * 448 */ 449static int 450ngdioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct thread *td) 451{ 452 struct ngd_softc *sc = &ngd_softc; 453 struct ngd_connection * connection = NULL; 454 struct ngd_connection * tmp; 455 int error = 0; 456 struct ng_mesg *msg; 457 struct ngd_param_s * datap; 458 459#ifdef NGD_DEBUG 460 printf("%s()\n",__func__); 461#endif /* NGD_DEBUG */ 462 463 SLIST_FOREACH(tmp,&sc->head,links) { 464 if(tmp->ngddev == dev) { 465 connection = tmp; 466 } 467 } 468 if(connection == NULL) { 469 printf("%s(): connection is still NULL, no dev found\n",__func__); 470 return(-1); 471 } 472 473 /* NG_MKMESSAGE(msg, cookie, cmdid, len, how) */ 474 NG_MKMESSAGE(msg, NGM_DEVICE_COOKIE, cmd, sizeof(struct ngd_param_s), 475 M_NOWAIT); 476 if (msg == NULL) { 477 printf("%s(): msg == NULL\n",__func__); 478 goto nomsg; 479 } 480 481 /* pass the ioctl data into the ->data area */ 482 datap = (struct ngd_param_s *)msg->data; 483 datap->p = addr; 484 485 /* NG_SEND_MSG_HOOK(error, here, msg, hook, retaddr) */ 486 NG_SEND_MSG_HOOK(error, sc->node, msg, connection->active_hook, NULL); 487 if(error) 488 printf("%s(): NG_SEND_MSG_HOOK error: %d\n",__func__,error); 489 490nomsg: 491 492 return(0); 493} 494 495 496/* 497 * This function is called when a read(2) is done to our device. 498 * We pass the data available in kernelspace on into userland using 499 * uiomove. 500 */ 501static int 502ngdread(dev_t dev, struct uio *uio, int flag) 503{ 504 int ret = 0, amnt; 505 char buffer[uio->uio_resid+1]; 506 struct ngd_softc *sc = &ngd_softc; 507 struct ngd_connection * connection = NULL; 508 struct ngd_connection * tmp; 509 510#ifdef NGD_DEBUG 511 printf("%s()\n",__func__); 512#endif /* NGD_DEBUG */ 513 514 SLIST_FOREACH(tmp,&sc->head,links) { 515 if(tmp->ngddev == dev) { 516 connection = tmp; 517 } 518 } 519 if(connection == NULL) { 520 printf("%s(): connection is still NULL, no dev found\n",__func__); 521 return(-1); 522 } 523 524 while ( ( uio->uio_resid > 0 ) && ( connection->loc > 0 ) ) { 525 amnt = MIN(uio->uio_resid,connection->loc); 526 527 memcpy(buffer,connection->readq, amnt); 528 memcpy(connection->readq, connection->readq+amnt, 529 connection->loc-amnt); 530 connection->loc -= amnt; 531 532 ret = uiomove((caddr_t)buffer, amnt, uio); 533 if(ret != 0) 534 goto error; 535 536 } 537 return(0); 538 539error: 540 printf("%s(): uiomove returns error %d\n",__func__,ret); 541 /* do error cleanup here */ 542 return(ret); 543} 544 545 546/* 547 * This function is called when our device is written to. 548 * We read the data from userland into our local buffer and pass it on 549 * into the remote hook. 550 * 551 */ 552static int 553ngdwrite(dev_t dev, struct uio *uio, int flag) 554{ 555 int ret; 556 int error = 0; 557 struct mbuf *m; 558 char buffer[uio->uio_resid]; 559 int len = uio->uio_resid; 560 struct ngd_softc *sc =& ngd_softc; 561 struct ngd_connection * connection = NULL; 562 struct ngd_connection * tmp; 563 564#ifdef NGD_DEBUG 565 printf("%s()\n",__func__); 566#endif /* NGD_DEBUG */ 567 568 SLIST_FOREACH(tmp,&sc->head,links) { 569 if(tmp->ngddev == dev) { 570 connection = tmp; 571 } 572 } 573 574 if(connection == NULL) { 575 printf("%s(): connection is still NULL, no dev found\n",__func__); 576 return(-1); 577 } 578 579 if (len > 0) { 580 if ((ret = uiomove((caddr_t)buffer, len, uio)) != 0) 581 goto error; 582 } else 583 printf("%s(): len <= 0 : is this supposed to happen?!\n",__func__); 584 585 m = m_devget(buffer,len,0,NULL,NULL); 586 587 NG_SEND_DATA_ONLY(error,connection->active_hook,m); 588 589 return(0); 590 591error: 592 /* do error cleanup here */ 593 printf("%s(): uiomove returned err: %d\n",__func__,ret); 594 595 return(ret); 596} 597 598/* 599 * we are being polled/selected 600 * check if there is data available for read 601 */ 602static int 603ngdpoll(dev_t dev, int events, struct thread *td) 604{ 605 int revents = 0; 606 struct ngd_softc *sc = &ngd_softc; 607 struct ngd_connection * connection = NULL; 608 struct ngd_connection * tmp; 609 610 611 if (events & (POLLIN | POLLRDNORM)) { 612 /* get the connection we have to know the loc from */ 613 SLIST_FOREACH(tmp,&sc->head,links) { 614 if(tmp->ngddev == dev) { 615 connection = tmp; 616 } 617 } 618 if(connection == NULL) { 619 printf("%s(): ERROR: connection is still NULL," 620 "no dev found\n",__func__); 621 return(-1); 622 } 623 624 if (connection->loc > 0) 625 revents |= events & (POLLIN | POLLRDNORM); 626 } 627 628 return(revents); 629} 630