2 * ng_etf.c Ethertype filter
6 * Copyright (c) 2001, FreeBSD Incorporated
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice unmodified, this list of conditions, and the following
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * Author: Julian Elischer <julian@freebsd.org>
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/ctype.h>
42 #include <sys/errno.h>
43 #include <sys/queue.h>
44 #include <sys/syslog.h>
46 #include <net/ethernet.h>
48 #include <netgraph/ng_message.h>
49 #include <netgraph/ng_parse.h>
50 #include <netgraph/ng_etf.h>
51 #include <netgraph/netgraph.h>
53 /* If you do complicated mallocs you may want to do this */
54 /* and use it for your mallocs */
55 #ifdef NG_SEPARATE_MALLOC
56 static MALLOC_DEFINE(M_NETGRAPH_ETF, "netgraph_etf", "netgraph etf node ");
58 #define M_NETGRAPH_ETF M_NETGRAPH
62 * This section contains the netgraph method declarations for the
63 * etf node. These methods define the netgraph 'type'.
66 static ng_constructor_t ng_etf_constructor;
67 static ng_rcvmsg_t ng_etf_rcvmsg;
68 static ng_shutdown_t ng_etf_shutdown;
69 static ng_newhook_t ng_etf_newhook;
70 static ng_rcvdata_t ng_etf_rcvdata; /* note these are both ng_rcvdata_t */
71 static ng_disconnect_t ng_etf_disconnect;
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
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
88 /* List of commands and how to convert arguments to/from ASCII */
89 static const struct ng_cmdlist ng_etf_cmdlist[] = {
101 &ng_parse_int32_type,
114 /* Netgraph node type descriptor */
115 static struct ng_type typestruct = {
116 .version = NG_ABI_VERSION,
117 .name = NG_ETF_NODE_TYPE,
118 .constructor = ng_etf_constructor,
119 .rcvmsg = ng_etf_rcvmsg,
120 .shutdown = ng_etf_shutdown,
121 .newhook = ng_etf_newhook,
122 .rcvdata = ng_etf_rcvdata,
123 .disconnect = ng_etf_disconnect,
124 .cmdlist = ng_etf_cmdlist,
126 NETGRAPH_INIT(etf, &typestruct);
128 /* Information we store for each hook on each node */
129 struct ETF_hookinfo {
134 LIST_ENTRY(filter) next;
135 u_int16_t ethertype; /* network order ethertype */
136 hook_p match_hook; /* Hook to use on a match */
139 #define HASHSIZE 16 /* Dont change this without changing HASH() */
140 #define HASH(et) ((((et)>>12)+((et)>>8)+((et)>>4)+(et)) & 0x0f)
141 LIST_HEAD(filterhead, filter);
143 /* Information we store for each node */
145 struct ETF_hookinfo downstream_hook;
146 struct ETF_hookinfo nomatch_hook;
147 node_p node; /* back pointer to node */
148 u_int packets_in; /* packets in from downstream */
149 u_int packets_out; /* packets out towards downstream */
151 struct filterhead hashtable[HASHSIZE];
153 typedef struct ETF *etf_p;
155 static struct filter *
156 ng_etf_findentry(etf_p etfp, u_int16_t ethertype)
158 struct filterhead *chain = etfp->hashtable + HASH(ethertype);
162 LIST_FOREACH(fil, chain, next) {
163 if (fil->ethertype == ethertype) {
172 * Allocate the private data structure. The generic node has already
173 * been created. Link them together. We arrive with a reference to the node
174 * i.e. the reference count is incremented for us already.
177 ng_etf_constructor(node_p node)
182 /* Initialize private descriptor */
183 privdata = malloc(sizeof(*privdata), M_NETGRAPH_ETF, M_WAITOK | M_ZERO);
184 for (i = 0; i < HASHSIZE; i++) {
185 LIST_INIT((privdata->hashtable + i));
188 /* Link structs together; this counts as our one reference to node */
189 NG_NODE_SET_PRIVATE(node, privdata);
190 privdata->node = node;
195 * Give our ok for a hook to be added...
196 * All names are ok. Two names are special.
199 ng_etf_newhook(node_p node, hook_p hook, const char *name)
201 const etf_p etfp = NG_NODE_PRIVATE(node);
202 struct ETF_hookinfo *hpriv;
204 if (strcmp(name, NG_ETF_HOOK_DOWNSTREAM) == 0) {
205 etfp->downstream_hook.hook = hook;
206 NG_HOOK_SET_PRIVATE(hook, &etfp->downstream_hook);
207 etfp->packets_in = 0;
208 etfp->packets_out = 0;
209 } else if (strcmp(name, NG_ETF_HOOK_NOMATCH) == 0) {
210 etfp->nomatch_hook.hook = hook;
211 NG_HOOK_SET_PRIVATE(hook, &etfp->nomatch_hook);
214 * Any other hook name is valid and can
215 * later be associated with a filter rule.
217 hpriv = malloc(sizeof(*hpriv),
218 M_NETGRAPH_ETF, M_NOWAIT | M_ZERO);
223 NG_HOOK_SET_PRIVATE(hook, hpriv);
230 * Get a netgraph control message.
231 * We actually recieve a queue item that has a pointer to the message.
232 * If we free the item, the message will be freed too, unless we remove
233 * it from the item using NGI_GET_MSG();
234 * The return address is also stored in the item, as an ng_ID_t,
235 * accessible as NGI_RETADDR(item);
236 * Check it is one we understand. If needed, send a response.
237 * We could save the address for an async action later, but don't here.
238 * Always free the message.
239 * The response should be in a malloc'd region that the caller can 'free'.
240 * The NG_MKRESPONSE macro does all this for us.
241 * A response is not required.
242 * Theoretically you could respond defferently to old message types if
243 * the cookie in the header didn't match what we consider to be current
244 * (so that old userland programs could continue to work).
247 ng_etf_rcvmsg(node_p node, item_p item, hook_p lasthook)
249 const etf_p etfp = NG_NODE_PRIVATE(node);
250 struct ng_mesg *resp = NULL;
254 NGI_GET_MSG(item, msg);
255 /* Deal with message according to cookie and command */
256 switch (msg->header.typecookie) {
258 switch (msg->header.cmd) {
259 case NGM_ETF_GET_STATUS:
261 struct ng_etfstat *stats;
263 NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
268 stats = (struct ng_etfstat *) resp->data;
269 stats->packets_in = etfp->packets_in;
270 stats->packets_out = etfp->packets_out;
273 case NGM_ETF_SET_FLAG:
274 if (msg->header.arglen != sizeof(u_int32_t)) {
278 etfp->flags = *((u_int32_t *) msg->data);
280 case NGM_ETF_SET_FILTER:
282 struct ng_etffilter *f;
286 /* Check message long enough for this command */
287 if (msg->header.arglen != sizeof(*f)) {
292 /* Make sure hook referenced exists */
293 f = (struct ng_etffilter *)msg->data;
294 hook = ng_findhook(node, f->matchhook);
300 /* and is not the downstream hook */
301 if (hook == etfp->downstream_hook.hook) {
306 /* Check we don't already trap this ethertype */
307 if (ng_etf_findentry(etfp,
308 htons(f->ethertype))) {
314 * Ok, make the filter and put it in the
315 * hashtable ready for matching.
317 fil = malloc(sizeof(*fil),
318 M_NETGRAPH_ETF, M_NOWAIT | M_ZERO);
324 fil->match_hook = hook;
325 fil->ethertype = htons(f->ethertype);
326 LIST_INSERT_HEAD( etfp->hashtable
327 + HASH(fil->ethertype),
332 error = EINVAL; /* unknown command */
337 error = EINVAL; /* unknown cookie type */
341 /* Take care of synchronous response, if any */
342 NG_RESPOND_MSG(error, node, item, resp);
343 /* Free the message and return */
349 * Receive data, and do something with it.
350 * Actually we receive a queue item which holds the data.
351 * If we free the item it will also free the data unless we have previously
352 * disassociated it using the NGI_GET_etf() macro.
353 * Possibly send it out on another link after processing.
354 * Possibly do something different if it comes from different
355 * hooks. The caller will never free m , so if we use up this data
356 * or abort we must free it.
358 * If we want, we may decide to force this data to be queued and reprocessed
359 * at the netgraph NETISR time.
360 * We would do that by setting the HK_QUEUE flag on our hook. We would do that
361 * in the connect() method.
364 ng_etf_rcvdata(hook_p hook, item_p item )
366 const etf_p etfp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
367 struct ether_header *eh;
373 if (NG_HOOK_PRIVATE(hook) == NULL) { /* Shouldn't happen but.. */
378 * Everything not from the downstream hook goes to the
379 * downstream hook. But only if it matches the ethertype
380 * of the source hook. Un matching must go to/from 'nomatch'.
383 /* Make sure we have an entire header */
385 if (m->m_len < sizeof(*eh) ) {
386 m = m_pullup(m, sizeof(*eh));
393 eh = mtod(m, struct ether_header *);
394 ethertype = eh->ether_type;
395 fil = ng_etf_findentry(etfp, ethertype);
398 * if from downstream, select between a match hook or
401 if (hook == etfp->downstream_hook.hook) {
403 if (fil && fil->match_hook) {
404 NG_FWD_NEW_DATA(error, item, fil->match_hook, m);
406 NG_FWD_NEW_DATA(error, item,etfp->nomatch_hook.hook, m);
410 * It must be heading towards the downstream.
411 * Check that it's ethertype matches
412 * the filters for it's input hook.
413 * If it doesn't have one, check it's from nomatch.
415 if ((fil && (fil->match_hook != hook))
416 || ((fil == NULL) && (hook != etfp->nomatch_hook.hook))) {
421 NG_FWD_NEW_DATA( error, item, etfp->downstream_hook.hook, m);
430 * Do local shutdown processing..
431 * All our links and the name have already been removed.
434 ng_etf_shutdown(node_p node)
436 const etf_p privdata = NG_NODE_PRIVATE(node);
438 NG_NODE_SET_PRIVATE(node, NULL);
439 NG_NODE_UNREF(privdata->node);
440 free(privdata, M_NETGRAPH_ETF);
447 * For this type, removal of the last link destroys the node
450 ng_etf_disconnect(hook_p hook)
452 const etf_p etfp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
454 struct filter *fil1, *fil2;
456 /* purge any rules that refer to this filter */
457 for (i = 0; i < HASHSIZE; i++) {
458 fil1 = LIST_FIRST(&etfp->hashtable[i]);
459 while (fil1 != NULL) {
460 fil2 = LIST_NEXT(fil1, next);
461 if (fil1->match_hook == hook) {
462 LIST_REMOVE(fil1, next);
463 free(fil1, M_NETGRAPH_ETF);
469 /* If it's not one of the special hooks, then free it */
470 if (hook == etfp->downstream_hook.hook) {
471 etfp->downstream_hook.hook = NULL;
472 } else if (hook == etfp->nomatch_hook.hook) {
473 etfp->nomatch_hook.hook = NULL;
475 if (NG_HOOK_PRIVATE(hook)) /* Paranoia */
476 free(NG_HOOK_PRIVATE(hook), M_NETGRAPH_ETF);
479 NG_HOOK_SET_PRIVATE(hook, NULL);
481 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
482 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) /* already shutting down? */
483 ng_rmnode_self(NG_HOOK_NODE(hook));