6 * Copyright (c) 1999 Whistle Communications, Inc.
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11 * without modifications are expressly permitted by Whistle Communications;
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38 * Author: Archie Cobbs <archie@freebsd.org>
41 * $Whistle: ng_bpf.c,v 1.3 1999/12/03 20:30:23 archie Exp $
45 * BPF NETGRAPH NODE TYPE
47 * This node type accepts any number of hook connections. With each hook
48 * is associated a bpf(4) filter program, and two hook names (each possibly
49 * the empty string). Incoming packets are compared against the filter;
50 * matching packets are delivered out the first named hook (or dropped if
51 * the empty string), and non-matching packets are delivered out the second
52 * named hook (or dropped if the empty string).
54 * Each hook also keeps statistics about how many packets have matched, etc.
59 #include <sys/param.h>
60 #include <sys/systm.h>
61 #include <sys/errno.h>
62 #include <sys/kernel.h>
63 #include <sys/malloc.h>
68 #include <net/bpf_jitter.h>
71 #include <netgraph/ng_message.h>
72 #include <netgraph/netgraph.h>
73 #include <netgraph/ng_parse.h>
74 #include <netgraph/ng_bpf.h>
76 #ifdef NG_SEPARATE_MALLOC
77 MALLOC_DEFINE(M_NETGRAPH_BPF, "netgraph_bpf", "netgraph bpf node ");
79 #define M_NETGRAPH_BPF M_NETGRAPH
82 #define OFFSETOF(s, e) ((char *)&((s *)0)->e - (char *)((s *)0))
84 #define ERROUT(x) do { error = (x); goto done; } while (0)
86 /* Per hook private info */
87 struct ng_bpf_hookinfo {
91 struct ng_bpf_hookprog *prog;
93 bpf_jit_filter *jit_prog;
95 struct ng_bpf_hookstat stats;
97 typedef struct ng_bpf_hookinfo *hinfo_p;
99 /* Netgraph methods */
100 static ng_constructor_t ng_bpf_constructor;
101 static ng_rcvmsg_t ng_bpf_rcvmsg;
102 static ng_shutdown_t ng_bpf_shutdown;
103 static ng_newhook_t ng_bpf_newhook;
104 static ng_rcvdata_t ng_bpf_rcvdata;
105 static ng_disconnect_t ng_bpf_disconnect;
107 /* Internal helper functions */
108 static int ng_bpf_setprog(hook_p hook, const struct ng_bpf_hookprog *hp);
110 /* Parse type for one struct bfp_insn */
111 static const struct ng_parse_struct_field ng_bpf_insn_type_fields[] = {
112 { "code", &ng_parse_hint16_type },
113 { "jt", &ng_parse_uint8_type },
114 { "jf", &ng_parse_uint8_type },
115 { "k", &ng_parse_uint32_type },
118 static const struct ng_parse_type ng_bpf_insn_type = {
119 &ng_parse_struct_type,
120 &ng_bpf_insn_type_fields
123 /* Parse type for the field 'bpf_prog' in struct ng_bpf_hookprog */
125 ng_bpf_hookprogary_getLength(const struct ng_parse_type *type,
126 const u_char *start, const u_char *buf)
128 const struct ng_bpf_hookprog *hp;
130 hp = (const struct ng_bpf_hookprog *)
131 (buf - OFFSETOF(struct ng_bpf_hookprog, bpf_prog));
132 return hp->bpf_prog_len;
135 static const struct ng_parse_array_info ng_bpf_hookprogary_info = {
137 &ng_bpf_hookprogary_getLength,
140 static const struct ng_parse_type ng_bpf_hookprogary_type = {
141 &ng_parse_array_type,
142 &ng_bpf_hookprogary_info
145 /* Parse type for struct ng_bpf_hookprog */
146 static const struct ng_parse_struct_field ng_bpf_hookprog_type_fields[]
147 = NG_BPF_HOOKPROG_TYPE_INFO(&ng_bpf_hookprogary_type);
148 static const struct ng_parse_type ng_bpf_hookprog_type = {
149 &ng_parse_struct_type,
150 &ng_bpf_hookprog_type_fields
153 /* Parse type for struct ng_bpf_hookstat */
154 static const struct ng_parse_struct_field ng_bpf_hookstat_type_fields[]
155 = NG_BPF_HOOKSTAT_TYPE_INFO;
156 static const struct ng_parse_type ng_bpf_hookstat_type = {
157 &ng_parse_struct_type,
158 &ng_bpf_hookstat_type_fields
161 /* List of commands and how to convert arguments to/from ASCII */
162 static const struct ng_cmdlist ng_bpf_cmdlist[] = {
167 &ng_bpf_hookprog_type,
174 &ng_parse_hookbuf_type,
175 &ng_bpf_hookprog_type
181 &ng_parse_hookbuf_type,
182 &ng_bpf_hookstat_type
188 &ng_parse_hookbuf_type,
193 NGM_BPF_GETCLR_STATS,
195 &ng_parse_hookbuf_type,
196 &ng_bpf_hookstat_type
201 /* Netgraph type descriptor */
202 static struct ng_type typestruct = {
203 .version = NG_ABI_VERSION,
204 .name = NG_BPF_NODE_TYPE,
205 .constructor = ng_bpf_constructor,
206 .rcvmsg = ng_bpf_rcvmsg,
207 .shutdown = ng_bpf_shutdown,
208 .newhook = ng_bpf_newhook,
209 .rcvdata = ng_bpf_rcvdata,
210 .disconnect = ng_bpf_disconnect,
211 .cmdlist = ng_bpf_cmdlist,
213 NETGRAPH_INIT(bpf, &typestruct);
215 /* Default BPF program for a hook that matches nothing */
216 static const struct ng_bpf_hookprog ng_bpf_default_prog = {
217 { '\0' }, /* to be filled in at hook creation time */
221 { BPF_STMT(BPF_RET+BPF_K, 0) }
227 * We don't keep any per-node private data
228 * We go via the hooks.
231 ng_bpf_constructor(node_p node)
233 NG_NODE_SET_PRIVATE(node, NULL);
238 * Callback functions to be used by NG_NODE_FOREACH_HOOK() macro.
241 ng_bpf_addrefs(hook_p hook, void* arg)
243 hinfo_p hip = NG_HOOK_PRIVATE(hook);
244 hook_p h = (hook_p)arg;
246 if (strcmp(hip->prog->ifMatch, NG_HOOK_NAME(h)) == 0)
248 if (strcmp(hip->prog->ifNotMatch, NG_HOOK_NAME(h)) == 0)
254 ng_bpf_remrefs(hook_p hook, void* arg)
256 hinfo_p hip = NG_HOOK_PRIVATE(hook);
257 hook_p h = (hook_p)arg;
261 if (hip->nomatch == h)
270 ng_bpf_newhook(node_p node, hook_p hook, const char *name)
276 /* Create hook private structure */
277 MALLOC(hip, hinfo_p, 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, tmp);
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 MALLOC(data, u_char *, 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 */
481 /* XXX atomically? */
482 hip->stats.recvMatchFrames++;
483 hip->stats.recvMatchOctets += totlen;
485 /* Truncate packet length if required by the filter */
486 /* Assume this never changes m */
488 m_adj(m, -(totlen - len));
499 /* Deliver frame out destination hook */
500 dhip = NG_HOOK_PRIVATE(dest);
501 dhip->stats.xmitOctets += totlen;
502 dhip->stats.xmitFrames++;
503 NG_FWD_ITEM_HOOK(error, item, dest);
508 * Shutdown processing
511 ng_bpf_shutdown(node_p node)
521 ng_bpf_disconnect(hook_p hook)
523 const node_p node = NG_HOOK_NODE(hook);
524 const hinfo_p hip = NG_HOOK_PRIVATE(hook);
527 KASSERT(hip != NULL, ("%s: null info", __func__));
529 /* Remove our reference from other hooks data. */
530 NG_NODE_FOREACH_HOOK(node, ng_bpf_remrefs, hook, tmp);
532 FREE(hip->prog, M_NETGRAPH_BPF);
534 if (hip->jit_prog != NULL)
535 bpf_destroy_jit_filter(hip->jit_prog);
537 FREE(hip, M_NETGRAPH_BPF);
538 if ((NG_NODE_NUMHOOKS(node) == 0) &&
539 (NG_NODE_IS_VALID(node))) {
540 ng_rmnode_self(node);
545 /************************************************************************
547 ************************************************************************/
550 * Set the BPF program associated with a hook
553 ng_bpf_setprog(hook_p hook, const struct ng_bpf_hookprog *hp0)
555 const hinfo_p hip = NG_HOOK_PRIVATE(hook);
556 struct ng_bpf_hookprog *hp;
558 bpf_jit_filter *jit_prog;
562 /* Check program for validity */
563 if (!bpf_validate(hp0->bpf_prog, hp0->bpf_prog_len))
566 /* Make a copy of the program */
567 size = NG_BPF_HOOKPROG_SIZE(hp0->bpf_prog_len);
568 MALLOC(hp, struct ng_bpf_hookprog *, size, M_NETGRAPH_BPF, M_NOWAIT);
571 bcopy(hp0, hp, size);
573 jit_prog = bpf_jitter(hp->bpf_prog, hp->bpf_prog_len);
576 /* Free previous program, if any, and assign new one */
577 if (hip->prog != NULL)
578 FREE(hip->prog, M_NETGRAPH_BPF);
581 if (hip->jit_prog != NULL)
582 bpf_destroy_jit_filter(hip->jit_prog);
583 hip->jit_prog = jit_prog;
586 /* Prepare direct references on target hooks. */
587 hip->match = ng_findhook(NG_HOOK_NODE(hook), hip->prog->ifMatch);
588 hip->nomatch = ng_findhook(NG_HOOK_NODE(hook), hip->prog->ifNotMatch);