6 * Copyright (c) 1999 Whistle Communications, Inc.
9 * Subject to the following obligations and disclaimer of warranty, use and
10 * redistribution of this software, in source or object code forms, with or
11 * without modifications are expressly permitted by Whistle Communications;
12 * provided, however, that:
13 * 1. Any and all reproductions of the source or object code must include the
14 * copyright notice above and the following disclaimer of warranties; and
15 * 2. No rights are granted, in any manner or form, to use Whistle
16 * Communications, Inc. trademarks, including the mark "WHISTLE
17 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as
18 * such appears in the above copyright notice or in the software.
20 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
21 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
22 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
23 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
25 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
26 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
27 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
28 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
29 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
30 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
31 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
32 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
38 * Author: Archie Cobbs <archie@freebsd.org>
39 * $Whistle: ng_bpf.c,v 1.3 1999/12/03 20:30:23 archie Exp $
43 * BPF NETGRAPH NODE TYPE
45 * This node type accepts any number of hook connections. With each hook
46 * is associated a bpf(4) filter program, and two hook names (each possibly
47 * the empty string). Incoming packets are compared against the filter;
48 * matching packets are delivered out the first named hook (or dropped if
49 * the empty string), and non-matching packets are delivered out the second
50 * named hook (or dropped if the empty string).
52 * Each hook also keeps statistics about how many packets have matched, etc.
57 #include <sys/param.h>
58 #include <sys/systm.h>
59 #include <sys/errno.h>
60 #include <sys/kernel.h>
61 #include <sys/malloc.h>
66 #include <net/bpf_jitter.h>
69 #include <netgraph/ng_message.h>
70 #include <netgraph/netgraph.h>
71 #include <netgraph/ng_parse.h>
72 #include <netgraph/ng_bpf.h>
74 #ifdef NG_SEPARATE_MALLOC
75 static MALLOC_DEFINE(M_NETGRAPH_BPF, "netgraph_bpf", "netgraph bpf node");
77 #define M_NETGRAPH_BPF M_NETGRAPH
80 #define OFFSETOF(s, e) ((char *)&((s *)0)->e - (char *)((s *)0))
82 #define ERROUT(x) do { error = (x); goto done; } while (0)
84 /* Per hook private info */
85 struct ng_bpf_hookinfo {
89 struct ng_bpf_hookprog *prog;
91 bpf_jit_filter *jit_prog;
93 struct ng_bpf_hookstat stats;
95 typedef struct ng_bpf_hookinfo *hinfo_p;
97 /* Netgraph methods */
98 static ng_constructor_t ng_bpf_constructor;
99 static ng_rcvmsg_t ng_bpf_rcvmsg;
100 static ng_shutdown_t ng_bpf_shutdown;
101 static ng_newhook_t ng_bpf_newhook;
102 static ng_rcvdata_t ng_bpf_rcvdata;
103 static ng_disconnect_t ng_bpf_disconnect;
105 /* Maximum bpf program instructions */
106 extern int bpf_maxinsns;
108 /* Internal helper functions */
109 static int ng_bpf_setprog(hook_p hook, const struct ng_bpf_hookprog *hp);
111 /* Parse type for one struct bfp_insn */
112 static const struct ng_parse_struct_field ng_bpf_insn_type_fields[] = {
113 { "code", &ng_parse_hint16_type },
114 { "jt", &ng_parse_uint8_type },
115 { "jf", &ng_parse_uint8_type },
116 { "k", &ng_parse_uint32_type },
119 static const struct ng_parse_type ng_bpf_insn_type = {
120 &ng_parse_struct_type,
121 &ng_bpf_insn_type_fields
124 /* Parse type for the field 'bpf_prog' in struct ng_bpf_hookprog */
126 ng_bpf_hookprogary_getLength(const struct ng_parse_type *type,
127 const u_char *start, const u_char *buf)
129 const struct ng_bpf_hookprog *hp;
131 hp = (const struct ng_bpf_hookprog *)
132 (buf - OFFSETOF(struct ng_bpf_hookprog, bpf_prog));
133 return hp->bpf_prog_len;
136 static const struct ng_parse_array_info ng_bpf_hookprogary_info = {
138 &ng_bpf_hookprogary_getLength,
141 static const struct ng_parse_type ng_bpf_hookprogary_type = {
142 &ng_parse_array_type,
143 &ng_bpf_hookprogary_info
146 /* Parse type for struct ng_bpf_hookprog */
147 static const struct ng_parse_struct_field ng_bpf_hookprog_type_fields[]
148 = NG_BPF_HOOKPROG_TYPE_INFO(&ng_bpf_hookprogary_type);
149 static const struct ng_parse_type ng_bpf_hookprog_type = {
150 &ng_parse_struct_type,
151 &ng_bpf_hookprog_type_fields
154 /* Parse type for struct ng_bpf_hookstat */
155 static const struct ng_parse_struct_field ng_bpf_hookstat_type_fields[]
156 = NG_BPF_HOOKSTAT_TYPE_INFO;
157 static const struct ng_parse_type ng_bpf_hookstat_type = {
158 &ng_parse_struct_type,
159 &ng_bpf_hookstat_type_fields
162 /* List of commands and how to convert arguments to/from ASCII */
163 static const struct ng_cmdlist ng_bpf_cmdlist[] = {
168 &ng_bpf_hookprog_type,
175 &ng_parse_hookbuf_type,
176 &ng_bpf_hookprog_type
182 &ng_parse_hookbuf_type,
183 &ng_bpf_hookstat_type
189 &ng_parse_hookbuf_type,
194 NGM_BPF_GETCLR_STATS,
196 &ng_parse_hookbuf_type,
197 &ng_bpf_hookstat_type
202 /* Netgraph type descriptor */
203 static struct ng_type typestruct = {
204 .version = NG_ABI_VERSION,
205 .name = NG_BPF_NODE_TYPE,
206 .constructor = ng_bpf_constructor,
207 .rcvmsg = ng_bpf_rcvmsg,
208 .shutdown = ng_bpf_shutdown,
209 .newhook = ng_bpf_newhook,
210 .rcvdata = ng_bpf_rcvdata,
211 .disconnect = ng_bpf_disconnect,
212 .cmdlist = ng_bpf_cmdlist,
214 NETGRAPH_INIT(bpf, &typestruct);
216 /* Default BPF program for a hook that matches nothing */
217 static const struct ng_bpf_hookprog ng_bpf_default_prog = {
218 { '\0' }, /* to be filled in at hook creation time */
222 { BPF_STMT(BPF_RET+BPF_K, 0) }
228 * We don't keep any per-node private data
229 * We go via the hooks.
232 ng_bpf_constructor(node_p node)
234 NG_NODE_SET_PRIVATE(node, NULL);
239 * Callback functions to be used by NG_NODE_FOREACH_HOOK() macro.
242 ng_bpf_addrefs(hook_p hook, void* arg)
244 hinfo_p hip = NG_HOOK_PRIVATE(hook);
245 hook_p h = (hook_p)arg;
247 if (strcmp(hip->prog->ifMatch, NG_HOOK_NAME(h)) == 0)
249 if (strcmp(hip->prog->ifNotMatch, NG_HOOK_NAME(h)) == 0)
255 ng_bpf_remrefs(hook_p hook, void* arg)
257 hinfo_p hip = NG_HOOK_PRIVATE(hook);
258 hook_p h = (hook_p)arg;
262 if (hip->nomatch == h)
271 ng_bpf_newhook(node_p node, hook_p hook, const char *name)
276 /* Create hook private structure */
277 hip = malloc(sizeof(*hip), M_NETGRAPH_BPF, M_NOWAIT | M_ZERO);
281 NG_HOOK_SET_PRIVATE(hook, hip);
283 /* Add our reference into other hooks data. */
284 NG_NODE_FOREACH_HOOK(node, ng_bpf_addrefs, hook);
286 /* Attach the default BPF program */
287 if ((error = ng_bpf_setprog(hook, &ng_bpf_default_prog)) != 0) {
288 free(hip, M_NETGRAPH_BPF);
289 NG_HOOK_SET_PRIVATE(hook, NULL);
294 strlcpy(hip->prog->thisHook, name, sizeof(hip->prog->thisHook));
299 * Receive a control message
302 ng_bpf_rcvmsg(node_p node, item_p item, hook_p lasthook)
305 struct ng_mesg *resp = NULL;
308 NGI_GET_MSG(item, msg);
309 switch (msg->header.typecookie) {
311 switch (msg->header.cmd) {
312 case NGM_BPF_SET_PROGRAM:
314 struct ng_bpf_hookprog *const
315 hp = (struct ng_bpf_hookprog *)msg->data;
319 if (msg->header.arglen < sizeof(*hp)
320 || msg->header.arglen
321 != NG_BPF_HOOKPROG_SIZE(hp->bpf_prog_len))
325 if ((hook = ng_findhook(node, hp->thisHook)) == NULL)
328 /* Set new program */
329 if ((error = ng_bpf_setprog(hook, hp)) != 0)
334 case NGM_BPF_GET_PROGRAM:
336 struct ng_bpf_hookprog *hp;
340 if (msg->header.arglen == 0)
342 msg->data[msg->header.arglen - 1] = '\0';
345 if ((hook = ng_findhook(node, msg->data)) == NULL)
349 hp = ((hinfo_p)NG_HOOK_PRIVATE(hook))->prog;
350 NG_MKRESPONSE(resp, msg,
351 NG_BPF_HOOKPROG_SIZE(hp->bpf_prog_len), M_NOWAIT);
354 bcopy(hp, resp->data,
355 NG_BPF_HOOKPROG_SIZE(hp->bpf_prog_len));
359 case NGM_BPF_GET_STATS:
360 case NGM_BPF_CLR_STATS:
361 case NGM_BPF_GETCLR_STATS:
363 struct ng_bpf_hookstat *stats;
367 if (msg->header.arglen == 0)
369 msg->data[msg->header.arglen - 1] = '\0';
372 if ((hook = ng_findhook(node, msg->data)) == NULL)
374 stats = &((hinfo_p)NG_HOOK_PRIVATE(hook))->stats;
376 /* Build response (if desired) */
377 if (msg->header.cmd != NGM_BPF_CLR_STATS) {
379 msg, sizeof(*stats), M_NOWAIT);
382 bcopy(stats, resp->data, sizeof(*stats));
385 /* Clear stats (if desired) */
386 if (msg->header.cmd != NGM_BPF_GET_STATS)
387 bzero(stats, sizeof(*stats));
401 NG_RESPOND_MSG(error, node, item, resp);
407 * Receive data on a hook
409 * Apply the filter, and then drop or forward packet as appropriate.
412 ng_bpf_rcvdata(hook_p hook, item_p item)
414 const hinfo_p hip = NG_HOOK_PRIVATE(hook);
416 int needfree = 0, error = 0, usejit = 0;
423 m = NGI_M(item); /* 'item' still owns it.. we are peeking */
424 totlen = m->m_pkthdr.len;
425 /* Update stats on incoming hook. XXX Can we do 64 bits atomically? */
426 /* atomic_add_int64(&hip->stats.recvFrames, 1); */
427 /* atomic_add_int64(&hip->stats.recvOctets, totlen); */
428 hip->stats.recvFrames++;
429 hip->stats.recvOctets += totlen;
431 /* Don't call bpf_filter() with totlen == 0! */
438 if (bpf_jitter_enable != 0 && hip->jit_prog != NULL)
442 /* Need to put packet in contiguous memory for bpf */
443 if (m->m_next != NULL && totlen > MHLEN) {
445 data = malloc(totlen, M_NETGRAPH_BPF, M_NOWAIT);
451 m_copydata(m, 0, totlen, (caddr_t)data);
454 if (m->m_next != NULL) {
455 NGI_M(item) = m = m_pullup(m, totlen);
461 data = mtod(m, u_char *);
464 /* Run packet through filter */
467 len = (*(hip->jit_prog->func))(data, totlen, totlen);
471 len = bpf_filter(hip->prog->bpf_prog, data, totlen, totlen);
473 len = bpf_filter(hip->prog->bpf_prog, (u_char *)m, totlen, 0);
475 free(data, M_NETGRAPH_BPF);
477 /* See if we got a match and find destination hook */
480 /* XXX atomically? */
481 hip->stats.recvMatchFrames++;
482 hip->stats.recvMatchOctets += totlen;
484 /* Truncate packet length if required by the filter */
485 /* Assume this never changes m */
487 m_adj(m, -(totlen - len));
498 /* Deliver frame out destination hook */
499 dhip = NG_HOOK_PRIVATE(dest);
500 dhip->stats.xmitOctets += totlen;
501 dhip->stats.xmitFrames++;
502 NG_FWD_ITEM_HOOK(error, item, dest);
507 * Shutdown processing
510 ng_bpf_shutdown(node_p node)
520 ng_bpf_disconnect(hook_p hook)
522 const node_p node = NG_HOOK_NODE(hook);
523 const hinfo_p hip = NG_HOOK_PRIVATE(hook);
525 KASSERT(hip != NULL, ("%s: null info", __func__));
527 /* Remove our reference from other hooks data. */
528 NG_NODE_FOREACH_HOOK(node, ng_bpf_remrefs, hook);
530 free(hip->prog, M_NETGRAPH_BPF);
532 if (hip->jit_prog != NULL)
533 bpf_destroy_jit_filter(hip->jit_prog);
535 free(hip, M_NETGRAPH_BPF);
536 if ((NG_NODE_NUMHOOKS(node) == 0) &&
537 (NG_NODE_IS_VALID(node))) {
538 ng_rmnode_self(node);
543 /************************************************************************
545 ************************************************************************/
548 * Set the BPF program associated with a hook
551 ng_bpf_setprog(hook_p hook, const struct ng_bpf_hookprog *hp0)
553 const hinfo_p hip = NG_HOOK_PRIVATE(hook);
554 struct ng_bpf_hookprog *hp;
556 bpf_jit_filter *jit_prog;
560 /* Check program for validity */
561 if (hp0->bpf_prog_len > bpf_maxinsns ||
562 !bpf_validate(hp0->bpf_prog, hp0->bpf_prog_len))
565 /* Make a copy of the program */
566 size = NG_BPF_HOOKPROG_SIZE(hp0->bpf_prog_len);
567 hp = malloc(size, M_NETGRAPH_BPF, M_NOWAIT);
570 bcopy(hp0, hp, size);
572 jit_prog = bpf_jitter(hp->bpf_prog, hp->bpf_prog_len);
575 /* Free previous program, if any, and assign new one */
576 if (hip->prog != NULL)
577 free(hip->prog, M_NETGRAPH_BPF);
580 if (hip->jit_prog != NULL)
581 bpf_destroy_jit_filter(hip->jit_prog);
582 hip->jit_prog = jit_prog;
585 /* Prepare direct references on target hooks. */
586 hip->match = ng_findhook(NG_HOOK_NODE(hook), hip->prog->ifMatch);
587 hip->nomatch = ng_findhook(NG_HOOK_NODE(hook), hip->prog->ifNotMatch);