1 /*- 2 * ng_etf.c Ethertype filter 3 * 4 * Copyright (c) 2001, FreeBSD Incorporated 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice unmodified, this list of conditions, and the following 12 * disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * Author: Julian Elischer <julian@freebsd.org> 30 * 31 * $FreeBSD: src/sys/netgraph/ng_etf.c,v 1.1.2.2 2002/07/02 23:44:02 archie Exp $ 32 * $DragonFly: src/sys/netgraph/etf/ng_etf.c,v 1.3 2003/08/07 21:17:31 dillon Exp $ 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/malloc.h> 40 #include <sys/ctype.h> 41 #include <sys/errno.h> 42 #include <sys/queue.h> 43 #include <sys/syslog.h> 44 45 #include <net/ethernet.h> 46 47 #include <netgraph/ng_message.h> 48 #include <netgraph/ng_parse.h> 49 #include "ng_etf.h" 50 #include <netgraph/netgraph.h> 51 52 /* If you do complicated mallocs you may want to do this */ 53 /* and use it for your mallocs */ 54 #ifdef NG_SEPARATE_MALLOC 55 MALLOC_DEFINE(M_NETGRAPH_ETF, "netgraph_etf", "netgraph etf node "); 56 #else 57 #define M_NETGRAPH_ETF M_NETGRAPH 58 #endif 59 60 /* 61 * This section contains the netgraph method declarations for the 62 * etf node. These methods define the netgraph 'type'. 63 */ 64 65 static ng_constructor_t ng_etf_constructor; 66 static ng_rcvmsg_t ng_etf_rcvmsg; 67 static ng_shutdown_t ng_etf_shutdown; 68 static ng_newhook_t ng_etf_newhook; 69 static ng_connect_t ng_etf_connect; 70 static ng_rcvdata_t ng_etf_rcvdata; /* note these are both ng_rcvdata_t */ 71 static ng_disconnect_t ng_etf_disconnect; 72 73 /* Parse type for struct ng_etfstat */ 74 static const struct ng_parse_struct_field ng_etf_stat_type_fields[] 75 = NG_ETF_STATS_TYPE_INFO; 76 static const struct ng_parse_type ng_etf_stat_type = { 77 &ng_parse_struct_type, 78 &ng_etf_stat_type_fields 79 }; 80 /* Parse type for struct ng_setfilter */ 81 static const struct ng_parse_struct_field ng_etf_filter_type_fields[] 82 = NG_ETF_FILTER_TYPE_INFO; 83 static const struct ng_parse_type ng_etf_filter_type = { 84 &ng_parse_struct_type, 85 &ng_etf_filter_type_fields 86 }; 87 88 /* List of commands and how to convert arguments to/from ASCII */ 89 static const struct ng_cmdlist ng_etf_cmdlist[] = { 90 { 91 NGM_ETF_COOKIE, 92 NGM_ETF_GET_STATUS, 93 "getstatus", 94 NULL, 95 &ng_etf_stat_type, 96 }, 97 { 98 NGM_ETF_COOKIE, 99 NGM_ETF_SET_FLAG, 100 "setflag", 101 &ng_parse_int32_type, 102 NULL 103 }, 104 { 105 NGM_ETF_COOKIE, 106 NGM_ETF_SET_FILTER, 107 "setfilter", 108 &ng_etf_filter_type, 109 NULL 110 }, 111 { 0 } 112 }; 113 114 /* Netgraph node type descriptor */ 115 static struct ng_type typestruct = { 116 NG_ABI_VERSION, 117 NG_ETF_NODE_TYPE, 118 NULL, 119 ng_etf_constructor, 120 ng_etf_rcvmsg, 121 ng_etf_shutdown, 122 ng_etf_newhook, 123 NULL, 124 ng_etf_connect, 125 ng_etf_rcvdata, 126 ng_etf_rcvdata, 127 ng_etf_disconnect, 128 ng_etf_cmdlist 129 }; 130 NETGRAPH_INIT(etf, &typestruct); 131 132 /* Information we store for each hook on each node */ 133 struct ETF_hookinfo { 134 hook_p hook; 135 }; 136 137 struct filter { 138 LIST_ENTRY(filter) next; 139 u_int16_t ethertype; /* network order ethertype */ 140 hook_p match_hook; /* Hook to use on a match */ 141 }; 142 143 #define HASHSIZE 16 /* Dont change this without changing HASH() */ 144 #define HASH(et) ((((et)>>12)+((et)>>8)+((et)>>4)+(et)) & 0x0f) 145 LIST_HEAD(filterhead, filter); 146 147 /* Information we store for each node */ 148 struct ETF { 149 struct ETF_hookinfo downstream_hook; 150 struct ETF_hookinfo nomatch_hook; 151 node_p node; /* back pointer to node */ 152 u_int packets_in; /* packets in from downstream */ 153 u_int packets_out; /* packets out towards downstream */ 154 u_int32_t flags; 155 struct filterhead hashtable[HASHSIZE]; 156 }; 157 typedef struct ETF *etf_p; 158 159 static struct filter * 160 ng_etf_findentry(etf_p etfp, u_int16_t ethertype) 161 { 162 struct filterhead *chain = etfp->hashtable + HASH(ethertype); 163 struct filter *fil; 164 165 166 LIST_FOREACH(fil, chain, next) { 167 if (fil->ethertype == ethertype) { 168 return (fil); 169 } 170 } 171 return (NULL); 172 } 173 174 175 /* 176 * Allocate the private data structure. The generic node has already 177 * been created. Link them together. We arrive with a reference to the node 178 * i.e. the reference count is incremented for us already. 179 */ 180 static int 181 ng_etf_constructor(node_p *nodep) 182 { 183 etf_p privdata; 184 int error, i; 185 186 /* Initialize private descriptor */ 187 MALLOC(privdata, etf_p, sizeof(*privdata), M_NETGRAPH_ETF, 188 M_NOWAIT | M_ZERO); 189 if (privdata == NULL) 190 return (ENOMEM); 191 for (i = 0; i < HASHSIZE; i++) { 192 LIST_INIT((privdata->hashtable + i)); 193 } 194 195 /* Call the 'generic' (ie, superclass) node constructor */ 196 if ((error = ng_make_node_common(&typestruct, nodep))) { 197 FREE(privdata, M_NETGRAPH); 198 return (error); 199 } 200 /* Link structs together; this counts as our one reference to node */ 201 NG_NODE_SET_PRIVATE((*nodep), privdata); 202 privdata->node = *nodep; 203 return (0); 204 } 205 206 /* 207 * Give our ok for a hook to be added... 208 * All names are ok. Two names are special. 209 */ 210 static int 211 ng_etf_newhook(node_p node, hook_p hook, const char *name) 212 { 213 const etf_p etfp = NG_NODE_PRIVATE(node); 214 struct ETF_hookinfo *hpriv; 215 216 if (strcmp(name, NG_ETF_HOOK_DOWNSTREAM) == 0) { 217 etfp->downstream_hook.hook = hook; 218 NG_HOOK_SET_PRIVATE(hook, &etfp->downstream_hook); 219 etfp->packets_in = 0; 220 etfp->packets_out = 0; 221 } else if (strcmp(name, NG_ETF_HOOK_NOMATCH) == 0) { 222 etfp->nomatch_hook.hook = hook; 223 NG_HOOK_SET_PRIVATE(hook, &etfp->nomatch_hook); 224 } else { 225 /* 226 * Any other hook name is valid and can 227 * later be associated with a filter rule. 228 */ 229 MALLOC(hpriv, struct ETF_hookinfo *, sizeof(*hpriv), 230 M_NETGRAPH_ETF, M_NOWAIT | M_ZERO); 231 if (hpriv == NULL) { 232 return (ENOMEM); 233 } 234 235 NG_HOOK_SET_PRIVATE(hook, hpriv); 236 hpriv->hook = hook; 237 } 238 return(0); 239 } 240 241 /* 242 * Get a netgraph control message. 243 * We actually recieve a queue item that has a pointer to the message. 244 * If we free the item, the message will be freed too, unless we remove 245 * it from the item using NGI_GET_MSG(); 246 * The return address is also stored in the item, as an ng_ID_t, 247 * accessible as NGI_RETADDR(item); 248 * Check it is one we understand. If needed, send a response. 249 * We could save the address for an async action later, but don't here. 250 * Always free the message. 251 * The response should be in a malloc'd region that the caller can 'free'. 252 * The NG_MKRESPONSE macro does all this for us. 253 * A response is not required. 254 * Theoretically you could respond defferently to old message types if 255 * the cookie in the header didn't match what we consider to be current 256 * (so that old userland programs could continue to work). 257 */ 258 static int 259 ng_etf_rcvmsg(node_p node, struct ng_mesg *msg, 260 const char *retaddr, struct ng_mesg **rptr) 261 { 262 const etf_p etfp = NG_NODE_PRIVATE(node); 263 struct ng_mesg *resp = NULL; 264 int error = 0; 265 266 /* Deal with message according to cookie and command */ 267 switch (msg->header.typecookie) { 268 case NGM_ETF_COOKIE: 269 switch (msg->header.cmd) { 270 case NGM_ETF_GET_STATUS: 271 { 272 struct ng_etfstat *stats; 273 274 NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT); 275 if (!resp) { 276 error = ENOMEM; 277 break; 278 } 279 stats = (struct ng_etfstat *) resp->data; 280 stats->packets_in = etfp->packets_in; 281 stats->packets_out = etfp->packets_out; 282 break; 283 } 284 case NGM_ETF_SET_FLAG: 285 if (msg->header.arglen != sizeof(u_int32_t)) { 286 error = EINVAL; 287 break; 288 } 289 etfp->flags = *((u_int32_t *) msg->data); 290 break; 291 case NGM_ETF_SET_FILTER: 292 { 293 struct ng_etffilter *f; 294 struct filter *fil; 295 hook_p hook; 296 297 /* Check message long enough for this command */ 298 if (msg->header.arglen != sizeof(*f)) { 299 error = EINVAL; 300 break; 301 } 302 303 /* Make sure hook referenced exists */ 304 f = (struct ng_etffilter *)msg->data; 305 hook = ng_findhook(node, f->matchhook); 306 if (hook == NULL) { 307 error = ENOENT; 308 break; 309 } 310 311 /* and is not the downstream hook */ 312 if (hook == etfp->downstream_hook.hook) { 313 error = EINVAL; 314 break; 315 } 316 317 /* Check we don't already trap this ethertype */ 318 if (ng_etf_findentry(etfp, 319 htons(f->ethertype))) { 320 error = EEXIST; 321 break; 322 } 323 324 /* 325 * Ok, make the filter and put it in the 326 * hashtable ready for matching. 327 */ 328 MALLOC(fil, struct filter *, sizeof(*fil), 329 M_NETGRAPH_ETF, M_NOWAIT | M_ZERO); 330 if (fil == NULL) { 331 return (ENOMEM); 332 } 333 334 fil->match_hook = hook; 335 fil->ethertype = htons(f->ethertype); 336 LIST_INSERT_HEAD( etfp->hashtable 337 + HASH(fil->ethertype), 338 fil, next); 339 } 340 break; 341 default: 342 error = EINVAL; /* unknown command */ 343 break; 344 } 345 break; 346 default: 347 error = EINVAL; /* unknown cookie type */ 348 break; 349 } 350 351 /* Take care of synchronous response, if any */ 352 NG_RESPOND_MSG(error, node, retaddr, resp, rptr); 353 /* Free the message and return */ 354 NG_FREE_MSG(msg); 355 return(error); 356 } 357 358 /* 359 * Receive data, and do something with it. 360 * Actually we receive a queue item which holds the data. 361 * If we free the item it wil also froo the data and metadata unless 362 * we have previously disassociated them using the NGI_GET_etf() macros. 363 * Possibly send it out on another link after processing. 364 * Possibly do something different if it comes from different 365 * hooks. the caller will never free m or meta, so 366 * if we use up this data or abort we must free BOTH of these. 367 * 368 * If we want, we may decide to force this data to be queued and reprocessed 369 * at the netgraph NETISR time. 370 * We would do that by setting the HK_QUEUE flag on our hook. We would do that 371 * in the connect() method. 372 */ 373 static int 374 ng_etf_rcvdata(hook_p hook, struct mbuf *m, meta_p meta) 375 { 376 const etf_p etfp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 377 struct ether_header *eh; 378 int error = 0; 379 u_int16_t ethertype; 380 struct filter *fil; 381 382 if (NG_HOOK_PRIVATE(hook) == NULL) { /* Shouldn't happen but.. */ 383 NG_FREE_DATA(m, meta); 384 } 385 386 /* 387 * Everything not from the downstream hook goes to the 388 * downstream hook. But only if it matches the ethertype 389 * of the source hook. Un matching must go to/from 'nomatch'. 390 */ 391 392 /* Make sure we have an entire header */ 393 if (m->m_len < sizeof(*eh) ) { 394 m = m_pullup(m, sizeof(*eh)); 395 if (m == NULL) { 396 NG_FREE_META(meta); 397 return(EINVAL); 398 } 399 } 400 401 eh = mtod(m, struct ether_header *); 402 ethertype = eh->ether_type; 403 fil = ng_etf_findentry(etfp, ethertype); 404 405 /* 406 * if from downstream, select between a match hook or 407 * the nomatch hook 408 */ 409 if (hook == etfp->downstream_hook.hook) { 410 etfp->packets_in++; 411 if (fil && fil->match_hook) { 412 NG_SEND_DATA(error, fil->match_hook, m, meta); 413 } else { 414 NG_SEND_DATA(error, etfp->nomatch_hook.hook, m, meta); 415 } 416 } else { 417 /* 418 * It must be heading towards the downstream. 419 * Check that it's ethertype matches 420 * the filters for it's input hook. 421 * If it doesn't have one, check it's from nomatch. 422 */ 423 if ((fil && (fil->match_hook != hook)) 424 || ((fil == NULL) && (hook != etfp->nomatch_hook.hook))) { 425 NG_FREE_DATA(m, meta); 426 return (EPROTOTYPE); 427 } 428 NG_SEND_DATA( error, etfp->downstream_hook.hook, m, meta); 429 if (error == 0) { 430 etfp->packets_out++; 431 } 432 } 433 return (error); 434 } 435 436 /* 437 * Do local shutdown processing.. 438 * All our links and the name have already been removed. 439 */ 440 static int 441 ng_etf_shutdown(node_p node) 442 { 443 const etf_p privdata = NG_NODE_PRIVATE(node); 444 445 NG_NODE_SET_PRIVATE(node, NULL); 446 NG_NODE_UNREF(privdata->node); 447 FREE(privdata, M_NETGRAPH_ETF); 448 return (0); 449 } 450 451 /* 452 * This is called once we've already connected a new hook to the other node. 453 * It gives us a chance to balk at the last minute. 454 */ 455 static int 456 ng_etf_connect(hook_p hook) 457 { 458 return (0); 459 } 460 461 /* 462 * Hook disconnection 463 * 464 * For this type, removal of the last link destroys the node 465 */ 466 static int 467 ng_etf_disconnect(hook_p hook) 468 { 469 const etf_p etfp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 470 int i; 471 struct filter *fil; 472 473 /* purge any rules that refer to this filter */ 474 for (i = 0; i < HASHSIZE; i++) { 475 LIST_FOREACH(fil, (etfp->hashtable + i), next) { 476 if (fil->match_hook == hook) { 477 LIST_REMOVE(fil, next); 478 } 479 } 480 } 481 482 /* If it's not one of the special hooks, then free it */ 483 if (hook == etfp->downstream_hook.hook) { 484 etfp->downstream_hook.hook = NULL; 485 } else if (hook == etfp->nomatch_hook.hook) { 486 etfp->nomatch_hook.hook = NULL; 487 } else { 488 if (NG_HOOK_PRIVATE(hook)) /* Paranoia */ 489 FREE(NG_HOOK_PRIVATE(hook), M_NETGRAPH_ETF); 490 } 491 492 NG_HOOK_SET_PRIVATE(hook, NULL); 493 494 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 495 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) /* already shutting down? */ 496 ng_rmnode(NG_HOOK_NODE(hook)); 497 return (0); 498 } 499 500