5 * Copyright (c) 1999 Whistle Communications, Inc.
8 * Subject to the following obligations and disclaimer of warranty, use and
9 * redistribution of this software, in source or object code forms, with or
10 * without modifications are expressly permitted by Whistle Communications;
11 * provided, however, that:
12 * 1. Any and all reproductions of the source or object code must include the
13 * copyright notice above and the following disclaimer of warranties; and
14 * 2. No rights are granted, in any manner or form, to use Whistle
15 * Communications, Inc. trademarks, including the mark "WHISTLE
16 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as
17 * such appears in the above copyright notice or in the software.
19 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
20 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
21 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
22 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
23 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
24 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANBPF, OR MAKE ANY
25 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
26 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
27 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
28 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
29 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
30 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
31 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
37 * Author: Archie Cobbs <archie@freebsd.org>
39 * $FreeBSD: src/sys/netgraph/ng_bpf.c,v 1.2.4.4 2002/07/02 23:44:02 archie Exp $
40 * $Whistle: ng_bpf.c,v 1.3 1999/12/03 20:30:23 archie Exp $
44 * BPF NETGRAPH NODE TYPE
46 * This node type accepts any number of hook connections. With each hook
47 * is associated a bpf(4) filter program, and two hook names (each possibly
48 * the empty string). Incoming packets are compared against the filter;
49 * matching packets are delivered out the first named hook (or dropped if
50 * the empty string), and non-matching packets are delivered out the second
51 * named hook (or dropped if the empty string).
53 * Each hook also keeps statistics about how many packets have matched, etc.
56 #include <sys/param.h>
57 #include <sys/systm.h>
58 #include <sys/errno.h>
59 #include <sys/kernel.h>
60 #include <sys/malloc.h>
65 #include <netgraph/ng_message.h>
66 #include <netgraph/netgraph.h>
67 #include <netgraph/ng_parse.h>
70 #define ERROUT(x) do { error = (x); goto done; } while (0)
72 /* Per hook private info */
73 struct ng_bpf_hookinfo {
76 struct ng_bpf_hookprog *prog;
77 struct ng_bpf_hookstat stats;
79 typedef struct ng_bpf_hookinfo *hinfo_p;
81 /* Netgraph methods */
82 static ng_constructor_t ng_bpf_constructor;
83 static ng_rcvmsg_t ng_bpf_rcvmsg;
84 static ng_shutdown_t ng_bpf_rmnode;
85 static ng_newhook_t ng_bpf_newhook;
86 static ng_rcvdata_t ng_bpf_rcvdata;
87 static ng_disconnect_t ng_bpf_disconnect;
89 /* Internal helper functions */
90 static int ng_bpf_setprog(hook_p hook, const struct ng_bpf_hookprog *hp);
92 /* Parse type for one struct bfp_insn */
93 static const struct ng_parse_struct_field ng_bpf_insn_type_fields[] = {
94 { "code", &ng_parse_hint16_type },
95 { "jt", &ng_parse_uint8_type },
96 { "jf", &ng_parse_uint8_type },
97 { "k", &ng_parse_uint32_type },
100 static const struct ng_parse_type ng_bpf_insn_type = {
101 &ng_parse_struct_type,
102 &ng_bpf_insn_type_fields
105 /* Parse type for the field 'bpf_prog' in struct ng_bpf_hookprog */
107 ng_bpf_hookprogary_getLength(const struct ng_parse_type *type,
108 const u_char *start, const u_char *buf)
110 const struct ng_bpf_hookprog *hp;
112 hp = (const struct ng_bpf_hookprog *)
113 (buf - __offsetof(struct ng_bpf_hookprog, bpf_prog));
114 return hp->bpf_prog_len;
117 static const struct ng_parse_array_info ng_bpf_hookprogary_info = {
119 &ng_bpf_hookprogary_getLength,
122 static const struct ng_parse_type ng_bpf_hookprogary_type = {
123 &ng_parse_array_type,
124 &ng_bpf_hookprogary_info
127 /* Parse type for struct ng_bpf_hookprog */
128 static const struct ng_parse_struct_field ng_bpf_hookprog_type_fields[]
129 = NG_BPF_HOOKPROG_TYPE_INFO(&ng_bpf_hookprogary_type);
130 static const struct ng_parse_type ng_bpf_hookprog_type = {
131 &ng_parse_struct_type,
132 &ng_bpf_hookprog_type_fields
135 /* Parse type for struct ng_bpf_hookstat */
136 static const struct ng_parse_struct_field ng_bpf_hookstat_type_fields[]
137 = NG_BPF_HOOKSTAT_TYPE_INFO;
138 static const struct ng_parse_type ng_bpf_hookstat_type = {
139 &ng_parse_struct_type,
140 &ng_bpf_hookstat_type_fields
143 /* List of commands and how to convert arguments to/from ASCII */
144 static const struct ng_cmdlist ng_bpf_cmdlist[] = {
149 &ng_bpf_hookprog_type,
156 &ng_parse_hookbuf_type,
157 &ng_bpf_hookprog_type
163 &ng_parse_hookbuf_type,
164 &ng_bpf_hookstat_type
170 &ng_parse_hookbuf_type,
175 NGM_BPF_GETCLR_STATS,
177 &ng_parse_hookbuf_type,
178 &ng_bpf_hookstat_type
183 /* Netgraph type descriptor */
184 static struct ng_type typestruct = {
199 NETGRAPH_INIT(bpf, &typestruct);
201 /* Default BPF program for a hook that matches nothing */
202 static const struct ng_bpf_hookprog ng_bpf_default_prog = {
203 { '\0' }, /* to be filled in at hook creation time */
207 { BPF_STMT(BPF_RET+BPF_K, 0) }
213 * We don't keep any per-node private data
216 ng_bpf_constructor(node_p *nodep)
220 if ((error = ng_make_node_common(&typestruct, nodep)))
222 (*nodep)->private = NULL;
230 ng_bpf_newhook(node_p node, hook_p hook, const char *name)
235 /* Create hook private structure */
236 hip = kmalloc(sizeof(*hip), M_NETGRAPH, M_NOWAIT | M_ZERO);
243 /* Attach the default BPF program */
244 if ((error = ng_bpf_setprog(hook, &ng_bpf_default_prog)) != 0) {
245 kfree(hip, M_NETGRAPH);
246 hook->private = NULL;
251 strncpy(hip->prog->thisHook, name, sizeof(hip->prog->thisHook) - 1);
252 hip->prog->thisHook[sizeof(hip->prog->thisHook) - 1] = '\0';
257 * Receive a control message
260 ng_bpf_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
261 struct ng_mesg **rptr)
263 struct ng_mesg *resp = NULL;
266 switch (msg->header.typecookie) {
268 switch (msg->header.cmd) {
269 case NGM_BPF_SET_PROGRAM:
271 struct ng_bpf_hookprog *const
272 hp = (struct ng_bpf_hookprog *)msg->data;
276 if (msg->header.arglen < sizeof(*hp)
277 || msg->header.arglen
278 != NG_BPF_HOOKPROG_SIZE(hp->bpf_prog_len))
282 if ((hook = ng_findhook(node, hp->thisHook)) == NULL)
285 /* Set new program */
286 if ((error = ng_bpf_setprog(hook, hp)) != 0)
291 case NGM_BPF_GET_PROGRAM:
293 struct ng_bpf_hookprog *hp;
297 if (msg->header.arglen == 0)
299 msg->data[msg->header.arglen - 1] = '\0';
302 if ((hook = ng_findhook(node, msg->data)) == NULL)
306 hp = ((hinfo_p)hook->private)->prog;
307 NG_MKRESPONSE(resp, msg,
308 NG_BPF_HOOKPROG_SIZE(hp->bpf_prog_len), M_NOWAIT);
311 bcopy(hp, resp->data,
312 NG_BPF_HOOKPROG_SIZE(hp->bpf_prog_len));
316 case NGM_BPF_GET_STATS:
317 case NGM_BPF_CLR_STATS:
318 case NGM_BPF_GETCLR_STATS:
320 struct ng_bpf_hookstat *stats;
324 if (msg->header.arglen == 0)
326 msg->data[msg->header.arglen - 1] = '\0';
329 if ((hook = ng_findhook(node, msg->data)) == NULL)
331 stats = &((hinfo_p)hook->private)->stats;
333 /* Build response (if desired) */
334 if (msg->header.cmd != NGM_BPF_CLR_STATS) {
336 msg, sizeof(*stats), M_NOWAIT);
339 bcopy(stats, resp->data, sizeof(*stats));
342 /* Clear stats (if desired) */
343 if (msg->header.cmd != NGM_BPF_GET_STATS)
344 bzero(stats, sizeof(*stats));
360 kfree(resp, M_NETGRAPH);
363 kfree(msg, M_NETGRAPH);
368 * Receive data on a hook
370 * Apply the filter, and then drop or forward packet as appropriate.
373 ng_bpf_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
375 const hinfo_p hip = hook->private;
376 int totlen = m->m_pkthdr.len;
377 int needfree = 0, error = 0;
378 u_char *data, buf[256];
383 /* Update stats on incoming hook */
384 hip->stats.recvFrames++;
385 hip->stats.recvOctets += totlen;
387 /* Need to put packet in contiguous memory for bpf */
388 if (m->m_next != NULL) {
389 if (totlen > sizeof(buf)) {
390 data = kmalloc(totlen, M_NETGRAPH, M_NOWAIT);
392 NG_FREE_DATA(m, meta);
398 m_copydata(m, 0, totlen, data);
400 data = mtod(m, u_char *);
402 /* Run packet through filter */
403 len = bpf_filter(hip->prog->bpf_prog, data, totlen, totlen);
405 kfree(data, M_NETGRAPH);
407 /* See if we got a match and find destination hook */
411 hip->stats.recvMatchFrames++;
412 hip->stats.recvMatchOctets += totlen;
414 /* Truncate packet length if required by the filter */
416 m_adj(m, -(totlen - len));
419 dest = ng_findhook(hip->node, hip->prog->ifMatch);
421 dest = ng_findhook(hip->node, hip->prog->ifNotMatch);
423 NG_FREE_DATA(m, meta);
427 /* Deliver frame out destination hook */
428 dhip = (hinfo_p)dest->private;
429 dhip->stats.xmitOctets += totlen;
430 dhip->stats.xmitFrames++;
431 NG_SEND_DATA(error, dest, m, meta);
436 * Shutdown processing
439 ng_bpf_rmnode(node_p node)
441 node->flags |= NG_INVALID;
452 ng_bpf_disconnect(hook_p hook)
454 const hinfo_p hip = hook->private;
456 KASSERT(hip != NULL, ("%s: null info", __func__));
457 kfree(hip->prog, M_NETGRAPH);
458 bzero(hip, sizeof(*hip));
459 kfree(hip, M_NETGRAPH);
460 hook->private = NULL; /* for good measure */
461 if (hook->node->numhooks == 0)
462 ng_rmnode(hook->node);
466 /************************************************************************
468 ************************************************************************/
471 * Set the BPF program associated with a hook
474 ng_bpf_setprog(hook_p hook, const struct ng_bpf_hookprog *hp0)
476 const hinfo_p hip = hook->private;
477 struct ng_bpf_hookprog *hp;
480 /* Check program for validity */
481 if (!bpf_validate(hp0->bpf_prog, hp0->bpf_prog_len))
484 /* Make a copy of the program */
485 size = NG_BPF_HOOKPROG_SIZE(hp0->bpf_prog_len);
486 hp = kmalloc(size, M_NETGRAPH, M_NOWAIT);
489 bcopy(hp0, hp, size);
491 /* Free previous program, if any, and assign new one */
492 if (hip->prog != NULL)
493 kfree(hip->prog, M_NETGRAPH);