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 {
90 struct ng_bpf_hookprog *prog;
92 bpf_jit_filter *jit_prog;
94 struct ng_bpf_hookstat stats;
96 typedef struct ng_bpf_hookinfo *hinfo_p;
98 /* Netgraph methods */
99 static ng_constructor_t ng_bpf_constructor;
100 static ng_rcvmsg_t ng_bpf_rcvmsg;
101 static ng_shutdown_t ng_bpf_shutdown;
102 static ng_newhook_t ng_bpf_newhook;
103 static ng_rcvdata_t ng_bpf_rcvdata;
104 static ng_disconnect_t ng_bpf_disconnect;
106 /* Internal helper functions */
107 static int ng_bpf_setprog(hook_p hook, const struct ng_bpf_hookprog *hp);
109 /* Parse type for one struct bfp_insn */
110 static const struct ng_parse_struct_field ng_bpf_insn_type_fields[] = {
111 { "code", &ng_parse_hint16_type },
112 { "jt", &ng_parse_uint8_type },
113 { "jf", &ng_parse_uint8_type },
114 { "k", &ng_parse_uint32_type },
117 static const struct ng_parse_type ng_bpf_insn_type = {
118 &ng_parse_struct_type,
119 &ng_bpf_insn_type_fields
122 /* Parse type for the field 'bpf_prog' in struct ng_bpf_hookprog */
124 ng_bpf_hookprogary_getLength(const struct ng_parse_type *type,
125 const u_char *start, const u_char *buf)
127 const struct ng_bpf_hookprog *hp;
129 hp = (const struct ng_bpf_hookprog *)
130 (buf - OFFSETOF(struct ng_bpf_hookprog, bpf_prog));
131 return hp->bpf_prog_len;
134 static const struct ng_parse_array_info ng_bpf_hookprogary_info = {
136 &ng_bpf_hookprogary_getLength,
139 static const struct ng_parse_type ng_bpf_hookprogary_type = {
140 &ng_parse_array_type,
141 &ng_bpf_hookprogary_info
144 /* Parse type for struct ng_bpf_hookprog */
145 static const struct ng_parse_struct_field ng_bpf_hookprog_type_fields[]
146 = NG_BPF_HOOKPROG_TYPE_INFO(&ng_bpf_hookprogary_type);
147 static const struct ng_parse_type ng_bpf_hookprog_type = {
148 &ng_parse_struct_type,
149 &ng_bpf_hookprog_type_fields
152 /* Parse type for struct ng_bpf_hookstat */
153 static const struct ng_parse_struct_field ng_bpf_hookstat_type_fields[]
154 = NG_BPF_HOOKSTAT_TYPE_INFO;
155 static const struct ng_parse_type ng_bpf_hookstat_type = {
156 &ng_parse_struct_type,
157 &ng_bpf_hookstat_type_fields
160 /* List of commands and how to convert arguments to/from ASCII */
161 static const struct ng_cmdlist ng_bpf_cmdlist[] = {
166 &ng_bpf_hookprog_type,
173 &ng_parse_hookbuf_type,
174 &ng_bpf_hookprog_type
180 &ng_parse_hookbuf_type,
181 &ng_bpf_hookstat_type
187 &ng_parse_hookbuf_type,
192 NGM_BPF_GETCLR_STATS,
194 &ng_parse_hookbuf_type,
195 &ng_bpf_hookstat_type
200 /* Netgraph type descriptor */
201 static struct ng_type typestruct = {
202 .version = NG_ABI_VERSION,
203 .name = NG_BPF_NODE_TYPE,
204 .constructor = ng_bpf_constructor,
205 .rcvmsg = ng_bpf_rcvmsg,
206 .shutdown = ng_bpf_shutdown,
207 .newhook = ng_bpf_newhook,
208 .rcvdata = ng_bpf_rcvdata,
209 .disconnect = ng_bpf_disconnect,
210 .cmdlist = ng_bpf_cmdlist,
212 NETGRAPH_INIT(bpf, &typestruct);
214 /* Default BPF program for a hook that matches nothing */
215 static const struct ng_bpf_hookprog ng_bpf_default_prog = {
216 { '\0' }, /* to be filled in at hook creation time */
220 { BPF_STMT(BPF_RET+BPF_K, 0) }
226 * We don't keep any per-node private data
227 * We go via the hooks.
230 ng_bpf_constructor(node_p node)
232 NG_NODE_SET_PRIVATE(node, NULL);
240 ng_bpf_newhook(node_p node, hook_p hook, const char *name)
245 /* Create hook private structure */
246 MALLOC(hip, hinfo_p, sizeof(*hip), M_NETGRAPH_BPF, M_NOWAIT | M_ZERO);
250 NG_HOOK_SET_PRIVATE(hook, hip);
253 /* Attach the default BPF program */
254 if ((error = ng_bpf_setprog(hook, &ng_bpf_default_prog)) != 0) {
255 FREE(hip, M_NETGRAPH_BPF);
256 NG_HOOK_SET_PRIVATE(hook, NULL);
261 strncpy(hip->prog->thisHook, name, sizeof(hip->prog->thisHook) - 1);
262 hip->prog->thisHook[sizeof(hip->prog->thisHook) - 1] = '\0';
267 * Receive a control message
270 ng_bpf_rcvmsg(node_p node, item_p item, hook_p lasthook)
273 struct ng_mesg *resp = NULL;
276 NGI_GET_MSG(item, msg);
277 switch (msg->header.typecookie) {
279 switch (msg->header.cmd) {
280 case NGM_BPF_SET_PROGRAM:
282 struct ng_bpf_hookprog *const
283 hp = (struct ng_bpf_hookprog *)msg->data;
287 if (msg->header.arglen < sizeof(*hp)
288 || msg->header.arglen
289 != NG_BPF_HOOKPROG_SIZE(hp->bpf_prog_len))
293 if ((hook = ng_findhook(node, hp->thisHook)) == NULL)
296 /* Set new program */
297 if ((error = ng_bpf_setprog(hook, hp)) != 0)
302 case NGM_BPF_GET_PROGRAM:
304 struct ng_bpf_hookprog *hp;
308 if (msg->header.arglen == 0)
310 msg->data[msg->header.arglen - 1] = '\0';
313 if ((hook = ng_findhook(node, msg->data)) == NULL)
317 hp = ((hinfo_p)NG_HOOK_PRIVATE(hook))->prog;
318 NG_MKRESPONSE(resp, msg,
319 NG_BPF_HOOKPROG_SIZE(hp->bpf_prog_len), M_NOWAIT);
322 bcopy(hp, resp->data,
323 NG_BPF_HOOKPROG_SIZE(hp->bpf_prog_len));
327 case NGM_BPF_GET_STATS:
328 case NGM_BPF_CLR_STATS:
329 case NGM_BPF_GETCLR_STATS:
331 struct ng_bpf_hookstat *stats;
335 if (msg->header.arglen == 0)
337 msg->data[msg->header.arglen - 1] = '\0';
340 if ((hook = ng_findhook(node, msg->data)) == NULL)
342 stats = &((hinfo_p)NG_HOOK_PRIVATE(hook))->stats;
344 /* Build response (if desired) */
345 if (msg->header.cmd != NGM_BPF_CLR_STATS) {
347 msg, sizeof(*stats), M_NOWAIT);
350 bcopy(stats, resp->data, sizeof(*stats));
353 /* Clear stats (if desired) */
354 if (msg->header.cmd != NGM_BPF_GET_STATS)
355 bzero(stats, sizeof(*stats));
369 NG_RESPOND_MSG(error, node, item, resp);
375 * Receive data on a hook
377 * Apply the filter, and then drop or forward packet as appropriate.
380 ng_bpf_rcvdata(hook_p hook, item_p item)
382 const hinfo_p hip = NG_HOOK_PRIVATE(hook);
384 int needfree = 0, error = 0;
385 u_char *data, buf[256];
391 m = NGI_M(item); /* 'item' still owns it.. we are peeking */
392 totlen = m->m_pkthdr.len;
393 /* Update stats on incoming hook. XXX Can we do 64 bits atomically? */
394 /* atomic_add_int64(&hip->stats.recvFrames, 1); */
395 /* atomic_add_int64(&hip->stats.recvOctets, totlen); */
396 hip->stats.recvFrames++;
397 hip->stats.recvOctets += totlen;
399 /* Need to put packet in contiguous memory for bpf */
400 if (m->m_next != NULL) {
401 if (totlen > sizeof(buf)) {
402 MALLOC(data, u_char *, totlen, M_NETGRAPH_BPF, M_NOWAIT);
410 m_copydata(m, 0, totlen, (caddr_t)data);
412 data = mtod(m, u_char *);
414 /* Run packet through filter */
416 len = 0; /* don't call bpf_filter() with totlen == 0! */
419 if (bpf_jitter_enable != 0 && hip->jit_prog != NULL)
420 len = (*(hip->jit_prog->func))(data, totlen, totlen);
423 len = bpf_filter(hip->prog->bpf_prog, data, totlen, totlen);
426 FREE(data, M_NETGRAPH_BPF);
428 /* See if we got a match and find destination hook */
432 /* XXX atomically? */
433 hip->stats.recvMatchFrames++;
434 hip->stats.recvMatchOctets += totlen;
436 /* Truncate packet length if required by the filter */
437 /* Assume this never changes m */
439 m_adj(m, -(totlen - len));
442 dest = ng_findhook(hip->node, hip->prog->ifMatch);
444 dest = ng_findhook(hip->node, hip->prog->ifNotMatch);
450 /* Deliver frame out destination hook */
451 dhip = NG_HOOK_PRIVATE(dest);
452 dhip->stats.xmitOctets += totlen;
453 dhip->stats.xmitFrames++;
454 NG_FWD_ITEM_HOOK(error, item, dest);
459 * Shutdown processing
462 ng_bpf_shutdown(node_p node)
472 ng_bpf_disconnect(hook_p hook)
474 const hinfo_p hip = NG_HOOK_PRIVATE(hook);
476 KASSERT(hip != NULL, ("%s: null info", __func__));
477 FREE(hip->prog, M_NETGRAPH_BPF);
479 if (hip->jit_prog != NULL)
480 bpf_destroy_jit_filter(hip->jit_prog);
482 bzero(hip, sizeof(*hip));
483 FREE(hip, M_NETGRAPH_BPF);
484 NG_HOOK_SET_PRIVATE(hook, NULL); /* for good measure */
485 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
486 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) {
487 ng_rmnode_self(NG_HOOK_NODE(hook));
492 /************************************************************************
494 ************************************************************************/
497 * Set the BPF program associated with a hook
500 ng_bpf_setprog(hook_p hook, const struct ng_bpf_hookprog *hp0)
502 const hinfo_p hip = NG_HOOK_PRIVATE(hook);
503 struct ng_bpf_hookprog *hp;
505 bpf_jit_filter *jit_prog;
509 /* Check program for validity */
510 if (!bpf_validate(hp0->bpf_prog, hp0->bpf_prog_len))
513 /* Make a copy of the program */
514 size = NG_BPF_HOOKPROG_SIZE(hp0->bpf_prog_len);
515 MALLOC(hp, struct ng_bpf_hookprog *, size, M_NETGRAPH_BPF, M_NOWAIT);
518 bcopy(hp0, hp, size);
520 jit_prog = bpf_jitter(hp->bpf_prog, hp->bpf_prog_len);
523 /* Free previous program, if any, and assign new one */
524 if (hip->prog != NULL)
525 FREE(hip->prog, M_NETGRAPH_BPF);
528 if (hip->jit_prog != NULL)
529 bpf_destroy_jit_filter(hip->jit_prog);
530 hip->jit_prog = jit_prog;