1 | /* $NetBSD: bpf.c,v 1.203 2016/07/19 02:47:45 pgoyette Exp $ */ |
2 | |
3 | /* |
4 | * Copyright (c) 1990, 1991, 1993 |
5 | * The Regents of the University of California. All rights reserved. |
6 | * |
7 | * This code is derived from the Stanford/CMU enet packet filter, |
8 | * (net/enet.c) distributed as part of 4.3BSD, and code contributed |
9 | * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence |
10 | * Berkeley Laboratory. |
11 | * |
12 | * Redistribution and use in source and binary forms, with or without |
13 | * modification, are permitted provided that the following conditions |
14 | * are met: |
15 | * 1. Redistributions of source code must retain the above copyright |
16 | * notice, this list of conditions and the following disclaimer. |
17 | * 2. Redistributions in binary form must reproduce the above copyright |
18 | * notice, this list of conditions and the following disclaimer in the |
19 | * documentation and/or other materials provided with the distribution. |
20 | * 3. Neither the name of the University nor the names of its contributors |
21 | * may be used to endorse or promote products derived from this software |
22 | * without specific prior written permission. |
23 | * |
24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
34 | * SUCH DAMAGE. |
35 | * |
36 | * @(#)bpf.c 8.4 (Berkeley) 1/9/95 |
37 | * static char rcsid[] = |
38 | * "Header: bpf.c,v 1.67 96/09/26 22:00:52 leres Exp "; |
39 | */ |
40 | |
41 | #include <sys/cdefs.h> |
42 | __KERNEL_RCSID(0, "$NetBSD: bpf.c,v 1.203 2016/07/19 02:47:45 pgoyette Exp $" ); |
43 | |
44 | #if defined(_KERNEL_OPT) |
45 | #include "opt_bpf.h" |
46 | #include "sl.h" |
47 | #include "strip.h" |
48 | #endif |
49 | |
50 | #include <sys/param.h> |
51 | #include <sys/systm.h> |
52 | #include <sys/mbuf.h> |
53 | #include <sys/buf.h> |
54 | #include <sys/time.h> |
55 | #include <sys/proc.h> |
56 | #include <sys/ioctl.h> |
57 | #include <sys/conf.h> |
58 | #include <sys/vnode.h> |
59 | #include <sys/queue.h> |
60 | #include <sys/stat.h> |
61 | #include <sys/module.h> |
62 | #include <sys/atomic.h> |
63 | |
64 | #include <sys/file.h> |
65 | #include <sys/filedesc.h> |
66 | #include <sys/tty.h> |
67 | #include <sys/uio.h> |
68 | |
69 | #include <sys/protosw.h> |
70 | #include <sys/socket.h> |
71 | #include <sys/errno.h> |
72 | #include <sys/kernel.h> |
73 | #include <sys/poll.h> |
74 | #include <sys/sysctl.h> |
75 | #include <sys/kauth.h> |
76 | |
77 | #include <net/if.h> |
78 | #include <net/slip.h> |
79 | |
80 | #include <net/bpf.h> |
81 | #include <net/bpfdesc.h> |
82 | #include <net/bpfjit.h> |
83 | |
84 | #include <net/if_arc.h> |
85 | #include <net/if_ether.h> |
86 | |
87 | #include <netinet/in.h> |
88 | #include <netinet/if_inarp.h> |
89 | |
90 | |
91 | #include <compat/sys/sockio.h> |
92 | |
93 | #ifndef BPF_BUFSIZE |
94 | /* |
95 | * 4096 is too small for FDDI frames. 8192 is too small for gigabit Ethernet |
96 | * jumbos (circa 9k), ATM, or Intel gig/10gig ethernet jumbos (16k). |
97 | */ |
98 | # define BPF_BUFSIZE 32768 |
99 | #endif |
100 | |
101 | #define PRINET 26 /* interruptible */ |
102 | |
103 | /* |
104 | * The default read buffer size, and limit for BIOCSBLEN, is sysctl'able. |
105 | * XXX the default values should be computed dynamically based |
106 | * on available memory size and available mbuf clusters. |
107 | */ |
108 | int bpf_bufsize = BPF_BUFSIZE; |
109 | int bpf_maxbufsize = BPF_DFLTBUFSIZE; /* XXX set dynamically, see above */ |
110 | bool bpf_jit = false; |
111 | |
112 | struct bpfjit_ops bpfjit_module_ops = { |
113 | .bj_generate_code = NULL, |
114 | .bj_free_code = NULL |
115 | }; |
116 | |
117 | /* |
118 | * Global BPF statistics returned by net.bpf.stats sysctl. |
119 | */ |
120 | struct bpf_stat bpf_gstats; |
121 | |
122 | /* |
123 | * Use a mutex to avoid a race condition between gathering the stats/peers |
124 | * and opening/closing the device. |
125 | */ |
126 | static kmutex_t bpf_mtx; |
127 | |
128 | /* |
129 | * bpf_iflist is the list of interfaces; each corresponds to an ifnet |
130 | * bpf_dtab holds the descriptors, indexed by minor device # |
131 | */ |
132 | struct bpf_if *bpf_iflist; |
133 | LIST_HEAD(, bpf_d) bpf_list; |
134 | |
135 | static int bpf_allocbufs(struct bpf_d *); |
136 | static void bpf_deliver(struct bpf_if *, |
137 | void *(*cpfn)(void *, const void *, size_t), |
138 | void *, u_int, u_int, const bool); |
139 | static void bpf_freed(struct bpf_d *); |
140 | static void bpf_ifname(struct ifnet *, struct ifreq *); |
141 | static void *bpf_mcpy(void *, const void *, size_t); |
142 | static int bpf_movein(struct uio *, int, uint64_t, |
143 | struct mbuf **, struct sockaddr *); |
144 | static void bpf_attachd(struct bpf_d *, struct bpf_if *); |
145 | static void bpf_detachd(struct bpf_d *); |
146 | static int bpf_setif(struct bpf_d *, struct ifreq *); |
147 | static void bpf_timed_out(void *); |
148 | static inline void |
149 | bpf_wakeup(struct bpf_d *); |
150 | static int bpf_hdrlen(struct bpf_d *); |
151 | static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, |
152 | void *(*)(void *, const void *, size_t), struct timespec *); |
153 | static void reset_d(struct bpf_d *); |
154 | static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); |
155 | static int bpf_setdlt(struct bpf_d *, u_int); |
156 | |
157 | static int bpf_read(struct file *, off_t *, struct uio *, kauth_cred_t, |
158 | int); |
159 | static int bpf_write(struct file *, off_t *, struct uio *, kauth_cred_t, |
160 | int); |
161 | static int bpf_ioctl(struct file *, u_long, void *); |
162 | static int bpf_poll(struct file *, int); |
163 | static int bpf_stat(struct file *, struct stat *); |
164 | static int bpf_close(struct file *); |
165 | static int bpf_kqfilter(struct file *, struct knote *); |
166 | static void bpf_softintr(void *); |
167 | |
168 | static const struct fileops bpf_fileops = { |
169 | .fo_read = bpf_read, |
170 | .fo_write = bpf_write, |
171 | .fo_ioctl = bpf_ioctl, |
172 | .fo_fcntl = fnullop_fcntl, |
173 | .fo_poll = bpf_poll, |
174 | .fo_stat = bpf_stat, |
175 | .fo_close = bpf_close, |
176 | .fo_kqfilter = bpf_kqfilter, |
177 | .fo_restart = fnullop_restart, |
178 | }; |
179 | |
180 | dev_type_open(bpfopen); |
181 | |
182 | const struct cdevsw bpf_cdevsw = { |
183 | .d_open = bpfopen, |
184 | .d_close = noclose, |
185 | .d_read = noread, |
186 | .d_write = nowrite, |
187 | .d_ioctl = noioctl, |
188 | .d_stop = nostop, |
189 | .d_tty = notty, |
190 | .d_poll = nopoll, |
191 | .d_mmap = nommap, |
192 | .d_kqfilter = nokqfilter, |
193 | .d_discard = nodiscard, |
194 | .d_flag = D_OTHER |
195 | }; |
196 | |
197 | bpfjit_func_t |
198 | bpf_jit_generate(bpf_ctx_t *bc, void *code, size_t size) |
199 | { |
200 | |
201 | membar_consumer(); |
202 | if (bpfjit_module_ops.bj_generate_code != NULL) { |
203 | return bpfjit_module_ops.bj_generate_code(bc, code, size); |
204 | } |
205 | return NULL; |
206 | } |
207 | |
208 | void |
209 | bpf_jit_freecode(bpfjit_func_t jcode) |
210 | { |
211 | KASSERT(bpfjit_module_ops.bj_free_code != NULL); |
212 | bpfjit_module_ops.bj_free_code(jcode); |
213 | } |
214 | |
215 | static int |
216 | bpf_movein(struct uio *uio, int linktype, uint64_t mtu, struct mbuf **mp, |
217 | struct sockaddr *sockp) |
218 | { |
219 | struct mbuf *m; |
220 | int error; |
221 | size_t len; |
222 | size_t hlen; |
223 | size_t align; |
224 | |
225 | /* |
226 | * Build a sockaddr based on the data link layer type. |
227 | * We do this at this level because the ethernet header |
228 | * is copied directly into the data field of the sockaddr. |
229 | * In the case of SLIP, there is no header and the packet |
230 | * is forwarded as is. |
231 | * Also, we are careful to leave room at the front of the mbuf |
232 | * for the link level header. |
233 | */ |
234 | switch (linktype) { |
235 | |
236 | case DLT_SLIP: |
237 | sockp->sa_family = AF_INET; |
238 | hlen = 0; |
239 | align = 0; |
240 | break; |
241 | |
242 | case DLT_PPP: |
243 | sockp->sa_family = AF_UNSPEC; |
244 | hlen = 0; |
245 | align = 0; |
246 | break; |
247 | |
248 | case DLT_EN10MB: |
249 | sockp->sa_family = AF_UNSPEC; |
250 | /* XXX Would MAXLINKHDR be better? */ |
251 | /* 6(dst)+6(src)+2(type) */ |
252 | hlen = sizeof(struct ether_header); |
253 | align = 2; |
254 | break; |
255 | |
256 | case DLT_ARCNET: |
257 | sockp->sa_family = AF_UNSPEC; |
258 | hlen = ARC_HDRLEN; |
259 | align = 5; |
260 | break; |
261 | |
262 | case DLT_FDDI: |
263 | sockp->sa_family = AF_LINK; |
264 | /* XXX 4(FORMAC)+6(dst)+6(src) */ |
265 | hlen = 16; |
266 | align = 0; |
267 | break; |
268 | |
269 | case DLT_ECONET: |
270 | sockp->sa_family = AF_UNSPEC; |
271 | hlen = 6; |
272 | align = 2; |
273 | break; |
274 | |
275 | case DLT_NULL: |
276 | sockp->sa_family = AF_UNSPEC; |
277 | hlen = 0; |
278 | align = 0; |
279 | break; |
280 | |
281 | default: |
282 | return (EIO); |
283 | } |
284 | |
285 | len = uio->uio_resid; |
286 | /* |
287 | * If there aren't enough bytes for a link level header or the |
288 | * packet length exceeds the interface mtu, return an error. |
289 | */ |
290 | if (len - hlen > mtu) |
291 | return (EMSGSIZE); |
292 | |
293 | /* |
294 | * XXX Avoid complicated buffer chaining --- |
295 | * bail if it won't fit in a single mbuf. |
296 | * (Take into account possible alignment bytes) |
297 | */ |
298 | if (len + align > MCLBYTES) |
299 | return (EIO); |
300 | |
301 | m = m_gethdr(M_WAIT, MT_DATA); |
302 | m_reset_rcvif(m); |
303 | m->m_pkthdr.len = (int)(len - hlen); |
304 | if (len + align > MHLEN) { |
305 | m_clget(m, M_WAIT); |
306 | if ((m->m_flags & M_EXT) == 0) { |
307 | error = ENOBUFS; |
308 | goto bad; |
309 | } |
310 | } |
311 | |
312 | /* Insure the data is properly aligned */ |
313 | if (align > 0) { |
314 | m->m_data += align; |
315 | m->m_len -= (int)align; |
316 | } |
317 | |
318 | error = uiomove(mtod(m, void *), len, uio); |
319 | if (error) |
320 | goto bad; |
321 | if (hlen != 0) { |
322 | memcpy(sockp->sa_data, mtod(m, void *), hlen); |
323 | m->m_data += hlen; /* XXX */ |
324 | len -= hlen; |
325 | } |
326 | m->m_len = (int)len; |
327 | *mp = m; |
328 | return (0); |
329 | |
330 | bad: |
331 | m_freem(m); |
332 | return (error); |
333 | } |
334 | |
335 | /* |
336 | * Attach file to the bpf interface, i.e. make d listen on bp. |
337 | * Must be called at splnet. |
338 | */ |
339 | static void |
340 | bpf_attachd(struct bpf_d *d, struct bpf_if *bp) |
341 | { |
342 | KASSERT(mutex_owned(&bpf_mtx)); |
343 | /* |
344 | * Point d at bp, and add d to the interface's list of listeners. |
345 | * Finally, point the driver's bpf cookie at the interface so |
346 | * it will divert packets to bpf. |
347 | */ |
348 | d->bd_bif = bp; |
349 | d->bd_next = bp->bif_dlist; |
350 | bp->bif_dlist = d; |
351 | |
352 | *bp->bif_driverp = bp; |
353 | } |
354 | |
355 | /* |
356 | * Detach a file from its interface. |
357 | */ |
358 | static void |
359 | bpf_detachd(struct bpf_d *d) |
360 | { |
361 | struct bpf_d **p; |
362 | struct bpf_if *bp; |
363 | |
364 | KASSERT(mutex_owned(&bpf_mtx)); |
365 | |
366 | bp = d->bd_bif; |
367 | /* |
368 | * Check if this descriptor had requested promiscuous mode. |
369 | * If so, turn it off. |
370 | */ |
371 | if (d->bd_promisc) { |
372 | int error __diagused; |
373 | |
374 | d->bd_promisc = 0; |
375 | /* |
376 | * Take device out of promiscuous mode. Since we were |
377 | * able to enter promiscuous mode, we should be able |
378 | * to turn it off. But we can get an error if |
379 | * the interface was configured down, so only panic |
380 | * if we don't get an unexpected error. |
381 | */ |
382 | error = ifpromisc(bp->bif_ifp, 0); |
383 | #ifdef DIAGNOSTIC |
384 | if (error) |
385 | printf("%s: ifpromisc failed: %d" , __func__, error); |
386 | #endif |
387 | } |
388 | /* Remove d from the interface's descriptor list. */ |
389 | p = &bp->bif_dlist; |
390 | while (*p != d) { |
391 | p = &(*p)->bd_next; |
392 | if (*p == NULL) |
393 | panic("%s: descriptor not in list" , __func__); |
394 | } |
395 | *p = (*p)->bd_next; |
396 | if (bp->bif_dlist == NULL) |
397 | /* |
398 | * Let the driver know that there are no more listeners. |
399 | */ |
400 | *d->bd_bif->bif_driverp = NULL; |
401 | d->bd_bif = NULL; |
402 | } |
403 | |
404 | static void |
405 | bpf_init(void) |
406 | { |
407 | |
408 | mutex_init(&bpf_mtx, MUTEX_DEFAULT, IPL_NONE); |
409 | |
410 | LIST_INIT(&bpf_list); |
411 | |
412 | bpf_gstats.bs_recv = 0; |
413 | bpf_gstats.bs_drop = 0; |
414 | bpf_gstats.bs_capt = 0; |
415 | |
416 | return; |
417 | } |
418 | |
419 | /* |
420 | * bpfilterattach() is called at boot time. We don't need to do anything |
421 | * here, since any initialization will happen as part of module init code. |
422 | */ |
423 | /* ARGSUSED */ |
424 | void |
425 | bpfilterattach(int n) |
426 | { |
427 | |
428 | } |
429 | |
430 | /* |
431 | * Open ethernet device. Clones. |
432 | */ |
433 | /* ARGSUSED */ |
434 | int |
435 | bpfopen(dev_t dev, int flag, int mode, struct lwp *l) |
436 | { |
437 | struct bpf_d *d; |
438 | struct file *fp; |
439 | int error, fd; |
440 | |
441 | /* falloc() will fill in the descriptor for us. */ |
442 | if ((error = fd_allocfile(&fp, &fd)) != 0) |
443 | return error; |
444 | |
445 | d = malloc(sizeof(*d), M_DEVBUF, M_WAITOK|M_ZERO); |
446 | d->bd_bufsize = bpf_bufsize; |
447 | d->bd_seesent = 1; |
448 | d->bd_feedback = 0; |
449 | d->bd_pid = l->l_proc->p_pid; |
450 | #ifdef _LP64 |
451 | if (curproc->p_flag & PK_32) |
452 | d->bd_compat32 = 1; |
453 | #endif |
454 | getnanotime(&d->bd_btime); |
455 | d->bd_atime = d->bd_mtime = d->bd_btime; |
456 | callout_init(&d->bd_callout, 0); |
457 | selinit(&d->bd_sel); |
458 | d->bd_sih = softint_establish(SOFTINT_CLOCK, bpf_softintr, d); |
459 | d->bd_jitcode = NULL; |
460 | |
461 | mutex_enter(&bpf_mtx); |
462 | LIST_INSERT_HEAD(&bpf_list, d, bd_list); |
463 | mutex_exit(&bpf_mtx); |
464 | |
465 | return fd_clone(fp, fd, flag, &bpf_fileops, d); |
466 | } |
467 | |
468 | /* |
469 | * Close the descriptor by detaching it from its interface, |
470 | * deallocating its buffers, and marking it free. |
471 | */ |
472 | /* ARGSUSED */ |
473 | static int |
474 | bpf_close(struct file *fp) |
475 | { |
476 | struct bpf_d *d; |
477 | int s; |
478 | |
479 | KERNEL_LOCK(1, NULL); |
480 | mutex_enter(&bpf_mtx); |
481 | |
482 | if ((d = fp->f_bpf) == NULL) { |
483 | mutex_exit(&bpf_mtx); |
484 | KERNEL_UNLOCK_ONE(NULL); |
485 | return 0; |
486 | } |
487 | |
488 | /* |
489 | * Refresh the PID associated with this bpf file. |
490 | */ |
491 | d->bd_pid = curproc->p_pid; |
492 | |
493 | s = splnet(); |
494 | if (d->bd_state == BPF_WAITING) |
495 | callout_stop(&d->bd_callout); |
496 | d->bd_state = BPF_IDLE; |
497 | if (d->bd_bif) |
498 | bpf_detachd(d); |
499 | splx(s); |
500 | bpf_freed(d); |
501 | LIST_REMOVE(d, bd_list); |
502 | fp->f_bpf = NULL; |
503 | |
504 | mutex_exit(&bpf_mtx); |
505 | KERNEL_UNLOCK_ONE(NULL); |
506 | |
507 | callout_destroy(&d->bd_callout); |
508 | seldestroy(&d->bd_sel); |
509 | softint_disestablish(d->bd_sih); |
510 | free(d, M_DEVBUF); |
511 | |
512 | return (0); |
513 | } |
514 | |
515 | /* |
516 | * Rotate the packet buffers in descriptor d. Move the store buffer |
517 | * into the hold slot, and the free buffer into the store slot. |
518 | * Zero the length of the new store buffer. |
519 | */ |
520 | #define ROTATE_BUFFERS(d) \ |
521 | (d)->bd_hbuf = (d)->bd_sbuf; \ |
522 | (d)->bd_hlen = (d)->bd_slen; \ |
523 | (d)->bd_sbuf = (d)->bd_fbuf; \ |
524 | (d)->bd_slen = 0; \ |
525 | (d)->bd_fbuf = NULL; |
526 | /* |
527 | * bpfread - read next chunk of packets from buffers |
528 | */ |
529 | static int |
530 | bpf_read(struct file *fp, off_t *offp, struct uio *uio, |
531 | kauth_cred_t cred, int flags) |
532 | { |
533 | struct bpf_d *d = fp->f_bpf; |
534 | int timed_out; |
535 | int error; |
536 | int s; |
537 | |
538 | getnanotime(&d->bd_atime); |
539 | /* |
540 | * Restrict application to use a buffer the same size as |
541 | * the kernel buffers. |
542 | */ |
543 | if (uio->uio_resid != d->bd_bufsize) |
544 | return (EINVAL); |
545 | |
546 | KERNEL_LOCK(1, NULL); |
547 | s = splnet(); |
548 | if (d->bd_state == BPF_WAITING) |
549 | callout_stop(&d->bd_callout); |
550 | timed_out = (d->bd_state == BPF_TIMED_OUT); |
551 | d->bd_state = BPF_IDLE; |
552 | /* |
553 | * If the hold buffer is empty, then do a timed sleep, which |
554 | * ends when the timeout expires or when enough packets |
555 | * have arrived to fill the store buffer. |
556 | */ |
557 | while (d->bd_hbuf == NULL) { |
558 | if (fp->f_flag & FNONBLOCK) { |
559 | if (d->bd_slen == 0) { |
560 | splx(s); |
561 | KERNEL_UNLOCK_ONE(NULL); |
562 | return (EWOULDBLOCK); |
563 | } |
564 | ROTATE_BUFFERS(d); |
565 | break; |
566 | } |
567 | |
568 | if ((d->bd_immediate || timed_out) && d->bd_slen != 0) { |
569 | /* |
570 | * A packet(s) either arrived since the previous |
571 | * read or arrived while we were asleep. |
572 | * Rotate the buffers and return what's here. |
573 | */ |
574 | ROTATE_BUFFERS(d); |
575 | break; |
576 | } |
577 | error = tsleep(d, PRINET|PCATCH, "bpf" , |
578 | d->bd_rtout); |
579 | if (error == EINTR || error == ERESTART) { |
580 | splx(s); |
581 | KERNEL_UNLOCK_ONE(NULL); |
582 | return (error); |
583 | } |
584 | if (error == EWOULDBLOCK) { |
585 | /* |
586 | * On a timeout, return what's in the buffer, |
587 | * which may be nothing. If there is something |
588 | * in the store buffer, we can rotate the buffers. |
589 | */ |
590 | if (d->bd_hbuf) |
591 | /* |
592 | * We filled up the buffer in between |
593 | * getting the timeout and arriving |
594 | * here, so we don't need to rotate. |
595 | */ |
596 | break; |
597 | |
598 | if (d->bd_slen == 0) { |
599 | splx(s); |
600 | KERNEL_UNLOCK_ONE(NULL); |
601 | return (0); |
602 | } |
603 | ROTATE_BUFFERS(d); |
604 | break; |
605 | } |
606 | if (error != 0) |
607 | goto done; |
608 | } |
609 | /* |
610 | * At this point, we know we have something in the hold slot. |
611 | */ |
612 | splx(s); |
613 | |
614 | /* |
615 | * Move data from hold buffer into user space. |
616 | * We know the entire buffer is transferred since |
617 | * we checked above that the read buffer is bpf_bufsize bytes. |
618 | */ |
619 | error = uiomove(d->bd_hbuf, d->bd_hlen, uio); |
620 | |
621 | s = splnet(); |
622 | d->bd_fbuf = d->bd_hbuf; |
623 | d->bd_hbuf = NULL; |
624 | d->bd_hlen = 0; |
625 | done: |
626 | splx(s); |
627 | KERNEL_UNLOCK_ONE(NULL); |
628 | return (error); |
629 | } |
630 | |
631 | |
632 | /* |
633 | * If there are processes sleeping on this descriptor, wake them up. |
634 | */ |
635 | static inline void |
636 | bpf_wakeup(struct bpf_d *d) |
637 | { |
638 | wakeup(d); |
639 | if (d->bd_async) |
640 | softint_schedule(d->bd_sih); |
641 | selnotify(&d->bd_sel, 0, 0); |
642 | } |
643 | |
644 | static void |
645 | bpf_softintr(void *cookie) |
646 | { |
647 | struct bpf_d *d; |
648 | |
649 | d = cookie; |
650 | if (d->bd_async) |
651 | fownsignal(d->bd_pgid, SIGIO, 0, 0, NULL); |
652 | } |
653 | |
654 | static void |
655 | bpf_timed_out(void *arg) |
656 | { |
657 | struct bpf_d *d = arg; |
658 | int s; |
659 | |
660 | s = splnet(); |
661 | if (d->bd_state == BPF_WAITING) { |
662 | d->bd_state = BPF_TIMED_OUT; |
663 | if (d->bd_slen != 0) |
664 | bpf_wakeup(d); |
665 | } |
666 | splx(s); |
667 | } |
668 | |
669 | |
670 | static int |
671 | bpf_write(struct file *fp, off_t *offp, struct uio *uio, |
672 | kauth_cred_t cred, int flags) |
673 | { |
674 | struct bpf_d *d = fp->f_bpf; |
675 | struct ifnet *ifp; |
676 | struct mbuf *m, *mc; |
677 | int error, s; |
678 | static struct sockaddr_storage dst; |
679 | |
680 | m = NULL; /* XXX gcc */ |
681 | |
682 | KERNEL_LOCK(1, NULL); |
683 | |
684 | if (d->bd_bif == NULL) { |
685 | KERNEL_UNLOCK_ONE(NULL); |
686 | return (ENXIO); |
687 | } |
688 | getnanotime(&d->bd_mtime); |
689 | |
690 | ifp = d->bd_bif->bif_ifp; |
691 | |
692 | if (uio->uio_resid == 0) { |
693 | KERNEL_UNLOCK_ONE(NULL); |
694 | return (0); |
695 | } |
696 | |
697 | error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp->if_mtu, &m, |
698 | (struct sockaddr *) &dst); |
699 | if (error) { |
700 | KERNEL_UNLOCK_ONE(NULL); |
701 | return (error); |
702 | } |
703 | |
704 | if (m->m_pkthdr.len > ifp->if_mtu) { |
705 | KERNEL_UNLOCK_ONE(NULL); |
706 | m_freem(m); |
707 | return (EMSGSIZE); |
708 | } |
709 | |
710 | if (d->bd_hdrcmplt) |
711 | dst.ss_family = pseudo_AF_HDRCMPLT; |
712 | |
713 | if (d->bd_feedback) { |
714 | mc = m_dup(m, 0, M_COPYALL, M_NOWAIT); |
715 | if (mc != NULL) |
716 | m_set_rcvif(mc, ifp); |
717 | /* Set M_PROMISC for outgoing packets to be discarded. */ |
718 | if (1 /*d->bd_direction == BPF_D_INOUT*/) |
719 | m->m_flags |= M_PROMISC; |
720 | } else |
721 | mc = NULL; |
722 | |
723 | s = splsoftnet(); |
724 | error = if_output_lock(ifp, ifp, m, (struct sockaddr *) &dst, NULL); |
725 | |
726 | if (mc != NULL) { |
727 | if (error == 0) |
728 | ifp->_if_input(ifp, mc); |
729 | else |
730 | m_freem(mc); |
731 | } |
732 | splx(s); |
733 | KERNEL_UNLOCK_ONE(NULL); |
734 | /* |
735 | * The driver frees the mbuf. |
736 | */ |
737 | return (error); |
738 | } |
739 | |
740 | /* |
741 | * Reset a descriptor by flushing its packet buffer and clearing the |
742 | * receive and drop counts. Should be called at splnet. |
743 | */ |
744 | static void |
745 | reset_d(struct bpf_d *d) |
746 | { |
747 | if (d->bd_hbuf) { |
748 | /* Free the hold buffer. */ |
749 | d->bd_fbuf = d->bd_hbuf; |
750 | d->bd_hbuf = NULL; |
751 | } |
752 | d->bd_slen = 0; |
753 | d->bd_hlen = 0; |
754 | d->bd_rcount = 0; |
755 | d->bd_dcount = 0; |
756 | d->bd_ccount = 0; |
757 | } |
758 | |
759 | /* |
760 | * FIONREAD Check for read packet available. |
761 | * BIOCGBLEN Get buffer len [for read()]. |
762 | * BIOCSETF Set ethernet read filter. |
763 | * BIOCFLUSH Flush read packet buffer. |
764 | * BIOCPROMISC Put interface into promiscuous mode. |
765 | * BIOCGDLT Get link layer type. |
766 | * BIOCGETIF Get interface name. |
767 | * BIOCSETIF Set interface. |
768 | * BIOCSRTIMEOUT Set read timeout. |
769 | * BIOCGRTIMEOUT Get read timeout. |
770 | * BIOCGSTATS Get packet stats. |
771 | * BIOCIMMEDIATE Set immediate mode. |
772 | * BIOCVERSION Get filter language version. |
773 | * BIOCGHDRCMPLT Get "header already complete" flag. |
774 | * BIOCSHDRCMPLT Set "header already complete" flag. |
775 | * BIOCSFEEDBACK Set packet feedback mode. |
776 | * BIOCGFEEDBACK Get packet feedback mode. |
777 | * BIOCGSEESENT Get "see sent packets" mode. |
778 | * BIOCSSEESENT Set "see sent packets" mode. |
779 | */ |
780 | /* ARGSUSED */ |
781 | static int |
782 | bpf_ioctl(struct file *fp, u_long cmd, void *addr) |
783 | { |
784 | struct bpf_d *d = fp->f_bpf; |
785 | int s, error = 0; |
786 | |
787 | /* |
788 | * Refresh the PID associated with this bpf file. |
789 | */ |
790 | KERNEL_LOCK(1, NULL); |
791 | d->bd_pid = curproc->p_pid; |
792 | #ifdef _LP64 |
793 | if (curproc->p_flag & PK_32) |
794 | d->bd_compat32 = 1; |
795 | else |
796 | d->bd_compat32 = 0; |
797 | #endif |
798 | |
799 | s = splnet(); |
800 | if (d->bd_state == BPF_WAITING) |
801 | callout_stop(&d->bd_callout); |
802 | d->bd_state = BPF_IDLE; |
803 | splx(s); |
804 | |
805 | switch (cmd) { |
806 | |
807 | default: |
808 | error = EINVAL; |
809 | break; |
810 | |
811 | /* |
812 | * Check for read packet available. |
813 | */ |
814 | case FIONREAD: |
815 | { |
816 | int n; |
817 | |
818 | s = splnet(); |
819 | n = d->bd_slen; |
820 | if (d->bd_hbuf) |
821 | n += d->bd_hlen; |
822 | splx(s); |
823 | |
824 | *(int *)addr = n; |
825 | break; |
826 | } |
827 | |
828 | /* |
829 | * Get buffer len [for read()]. |
830 | */ |
831 | case BIOCGBLEN: |
832 | *(u_int *)addr = d->bd_bufsize; |
833 | break; |
834 | |
835 | /* |
836 | * Set buffer length. |
837 | */ |
838 | case BIOCSBLEN: |
839 | if (d->bd_bif != NULL) |
840 | error = EINVAL; |
841 | else { |
842 | u_int size = *(u_int *)addr; |
843 | |
844 | if (size > bpf_maxbufsize) |
845 | *(u_int *)addr = size = bpf_maxbufsize; |
846 | else if (size < BPF_MINBUFSIZE) |
847 | *(u_int *)addr = size = BPF_MINBUFSIZE; |
848 | d->bd_bufsize = size; |
849 | } |
850 | break; |
851 | |
852 | /* |
853 | * Set link layer read filter. |
854 | */ |
855 | case BIOCSETF: |
856 | error = bpf_setf(d, addr); |
857 | break; |
858 | |
859 | /* |
860 | * Flush read packet buffer. |
861 | */ |
862 | case BIOCFLUSH: |
863 | s = splnet(); |
864 | reset_d(d); |
865 | splx(s); |
866 | break; |
867 | |
868 | /* |
869 | * Put interface into promiscuous mode. |
870 | */ |
871 | case BIOCPROMISC: |
872 | if (d->bd_bif == NULL) { |
873 | /* |
874 | * No interface attached yet. |
875 | */ |
876 | error = EINVAL; |
877 | break; |
878 | } |
879 | s = splnet(); |
880 | if (d->bd_promisc == 0) { |
881 | error = ifpromisc(d->bd_bif->bif_ifp, 1); |
882 | if (error == 0) |
883 | d->bd_promisc = 1; |
884 | } |
885 | splx(s); |
886 | break; |
887 | |
888 | /* |
889 | * Get device parameters. |
890 | */ |
891 | case BIOCGDLT: |
892 | if (d->bd_bif == NULL) |
893 | error = EINVAL; |
894 | else |
895 | *(u_int *)addr = d->bd_bif->bif_dlt; |
896 | break; |
897 | |
898 | /* |
899 | * Get a list of supported device parameters. |
900 | */ |
901 | case BIOCGDLTLIST: |
902 | if (d->bd_bif == NULL) |
903 | error = EINVAL; |
904 | else |
905 | error = bpf_getdltlist(d, addr); |
906 | break; |
907 | |
908 | /* |
909 | * Set device parameters. |
910 | */ |
911 | case BIOCSDLT: |
912 | mutex_enter(&bpf_mtx); |
913 | if (d->bd_bif == NULL) |
914 | error = EINVAL; |
915 | else |
916 | error = bpf_setdlt(d, *(u_int *)addr); |
917 | mutex_exit(&bpf_mtx); |
918 | break; |
919 | |
920 | /* |
921 | * Set interface name. |
922 | */ |
923 | #ifdef OBIOCGETIF |
924 | case OBIOCGETIF: |
925 | #endif |
926 | case BIOCGETIF: |
927 | if (d->bd_bif == NULL) |
928 | error = EINVAL; |
929 | else |
930 | bpf_ifname(d->bd_bif->bif_ifp, addr); |
931 | break; |
932 | |
933 | /* |
934 | * Set interface. |
935 | */ |
936 | #ifdef OBIOCSETIF |
937 | case OBIOCSETIF: |
938 | #endif |
939 | case BIOCSETIF: |
940 | mutex_enter(&bpf_mtx); |
941 | error = bpf_setif(d, addr); |
942 | mutex_exit(&bpf_mtx); |
943 | break; |
944 | |
945 | /* |
946 | * Set read timeout. |
947 | */ |
948 | case BIOCSRTIMEOUT: |
949 | { |
950 | struct timeval *tv = addr; |
951 | |
952 | /* Compute number of ticks. */ |
953 | d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick; |
954 | if ((d->bd_rtout == 0) && (tv->tv_usec != 0)) |
955 | d->bd_rtout = 1; |
956 | break; |
957 | } |
958 | |
959 | #ifdef BIOCGORTIMEOUT |
960 | /* |
961 | * Get read timeout. |
962 | */ |
963 | case BIOCGORTIMEOUT: |
964 | { |
965 | struct timeval50 *tv = addr; |
966 | |
967 | tv->tv_sec = d->bd_rtout / hz; |
968 | tv->tv_usec = (d->bd_rtout % hz) * tick; |
969 | break; |
970 | } |
971 | #endif |
972 | |
973 | #ifdef BIOCSORTIMEOUT |
974 | /* |
975 | * Set read timeout. |
976 | */ |
977 | case BIOCSORTIMEOUT: |
978 | { |
979 | struct timeval50 *tv = addr; |
980 | |
981 | /* Compute number of ticks. */ |
982 | d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick; |
983 | if ((d->bd_rtout == 0) && (tv->tv_usec != 0)) |
984 | d->bd_rtout = 1; |
985 | break; |
986 | } |
987 | #endif |
988 | |
989 | /* |
990 | * Get read timeout. |
991 | */ |
992 | case BIOCGRTIMEOUT: |
993 | { |
994 | struct timeval *tv = addr; |
995 | |
996 | tv->tv_sec = d->bd_rtout / hz; |
997 | tv->tv_usec = (d->bd_rtout % hz) * tick; |
998 | break; |
999 | } |
1000 | /* |
1001 | * Get packet stats. |
1002 | */ |
1003 | case BIOCGSTATS: |
1004 | { |
1005 | struct bpf_stat *bs = addr; |
1006 | |
1007 | bs->bs_recv = d->bd_rcount; |
1008 | bs->bs_drop = d->bd_dcount; |
1009 | bs->bs_capt = d->bd_ccount; |
1010 | break; |
1011 | } |
1012 | |
1013 | case BIOCGSTATSOLD: |
1014 | { |
1015 | struct bpf_stat_old *bs = addr; |
1016 | |
1017 | bs->bs_recv = d->bd_rcount; |
1018 | bs->bs_drop = d->bd_dcount; |
1019 | break; |
1020 | } |
1021 | |
1022 | /* |
1023 | * Set immediate mode. |
1024 | */ |
1025 | case BIOCIMMEDIATE: |
1026 | d->bd_immediate = *(u_int *)addr; |
1027 | break; |
1028 | |
1029 | case BIOCVERSION: |
1030 | { |
1031 | struct bpf_version *bv = addr; |
1032 | |
1033 | bv->bv_major = BPF_MAJOR_VERSION; |
1034 | bv->bv_minor = BPF_MINOR_VERSION; |
1035 | break; |
1036 | } |
1037 | |
1038 | case BIOCGHDRCMPLT: /* get "header already complete" flag */ |
1039 | *(u_int *)addr = d->bd_hdrcmplt; |
1040 | break; |
1041 | |
1042 | case BIOCSHDRCMPLT: /* set "header already complete" flag */ |
1043 | d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; |
1044 | break; |
1045 | |
1046 | /* |
1047 | * Get "see sent packets" flag |
1048 | */ |
1049 | case BIOCGSEESENT: |
1050 | *(u_int *)addr = d->bd_seesent; |
1051 | break; |
1052 | |
1053 | /* |
1054 | * Set "see sent" packets flag |
1055 | */ |
1056 | case BIOCSSEESENT: |
1057 | d->bd_seesent = *(u_int *)addr; |
1058 | break; |
1059 | |
1060 | /* |
1061 | * Set "feed packets from bpf back to input" mode |
1062 | */ |
1063 | case BIOCSFEEDBACK: |
1064 | d->bd_feedback = *(u_int *)addr; |
1065 | break; |
1066 | |
1067 | /* |
1068 | * Get "feed packets from bpf back to input" mode |
1069 | */ |
1070 | case BIOCGFEEDBACK: |
1071 | *(u_int *)addr = d->bd_feedback; |
1072 | break; |
1073 | |
1074 | case FIONBIO: /* Non-blocking I/O */ |
1075 | /* |
1076 | * No need to do anything special as we use IO_NDELAY in |
1077 | * bpfread() as an indication of whether or not to block |
1078 | * the read. |
1079 | */ |
1080 | break; |
1081 | |
1082 | case FIOASYNC: /* Send signal on receive packets */ |
1083 | d->bd_async = *(int *)addr; |
1084 | break; |
1085 | |
1086 | case TIOCSPGRP: /* Process or group to send signals to */ |
1087 | case FIOSETOWN: |
1088 | error = fsetown(&d->bd_pgid, cmd, addr); |
1089 | break; |
1090 | |
1091 | case TIOCGPGRP: |
1092 | case FIOGETOWN: |
1093 | error = fgetown(d->bd_pgid, cmd, addr); |
1094 | break; |
1095 | } |
1096 | KERNEL_UNLOCK_ONE(NULL); |
1097 | return (error); |
1098 | } |
1099 | |
1100 | /* |
1101 | * Set d's packet filter program to fp. If this file already has a filter, |
1102 | * free it and replace it. Returns EINVAL for bogus requests. |
1103 | */ |
1104 | int |
1105 | bpf_setf(struct bpf_d *d, struct bpf_program *fp) |
1106 | { |
1107 | struct bpf_insn *fcode, *old; |
1108 | bpfjit_func_t jcode, oldj; |
1109 | size_t flen, size; |
1110 | int s; |
1111 | |
1112 | jcode = NULL; |
1113 | flen = fp->bf_len; |
1114 | |
1115 | if ((fp->bf_insns == NULL && flen) || flen > BPF_MAXINSNS) { |
1116 | return EINVAL; |
1117 | } |
1118 | |
1119 | if (flen) { |
1120 | /* |
1121 | * Allocate the buffer, copy the byte-code from |
1122 | * userspace and validate it. |
1123 | */ |
1124 | size = flen * sizeof(*fp->bf_insns); |
1125 | fcode = malloc(size, M_DEVBUF, M_WAITOK); |
1126 | if (copyin(fp->bf_insns, fcode, size) != 0 || |
1127 | !bpf_validate(fcode, (int)flen)) { |
1128 | free(fcode, M_DEVBUF); |
1129 | return EINVAL; |
1130 | } |
1131 | membar_consumer(); |
1132 | if (bpf_jit) |
1133 | jcode = bpf_jit_generate(NULL, fcode, flen); |
1134 | } else { |
1135 | fcode = NULL; |
1136 | } |
1137 | |
1138 | s = splnet(); |
1139 | old = d->bd_filter; |
1140 | d->bd_filter = fcode; |
1141 | oldj = d->bd_jitcode; |
1142 | d->bd_jitcode = jcode; |
1143 | reset_d(d); |
1144 | splx(s); |
1145 | |
1146 | if (old) { |
1147 | free(old, M_DEVBUF); |
1148 | } |
1149 | if (oldj) { |
1150 | bpf_jit_freecode(oldj); |
1151 | } |
1152 | |
1153 | return 0; |
1154 | } |
1155 | |
1156 | /* |
1157 | * Detach a file from its current interface (if attached at all) and attach |
1158 | * to the interface indicated by the name stored in ifr. |
1159 | * Return an errno or 0. |
1160 | */ |
1161 | static int |
1162 | bpf_setif(struct bpf_d *d, struct ifreq *ifr) |
1163 | { |
1164 | struct bpf_if *bp; |
1165 | char *cp; |
1166 | int unit_seen, i, s, error; |
1167 | |
1168 | KASSERT(mutex_owned(&bpf_mtx)); |
1169 | /* |
1170 | * Make sure the provided name has a unit number, and default |
1171 | * it to '0' if not specified. |
1172 | * XXX This is ugly ... do this differently? |
1173 | */ |
1174 | unit_seen = 0; |
1175 | cp = ifr->ifr_name; |
1176 | cp[sizeof(ifr->ifr_name) - 1] = '\0'; /* sanity */ |
1177 | while (*cp++) |
1178 | if (*cp >= '0' && *cp <= '9') |
1179 | unit_seen = 1; |
1180 | if (!unit_seen) { |
1181 | /* Make sure to leave room for the '\0'. */ |
1182 | for (i = 0; i < (IFNAMSIZ - 1); ++i) { |
1183 | if ((ifr->ifr_name[i] >= 'a' && |
1184 | ifr->ifr_name[i] <= 'z') || |
1185 | (ifr->ifr_name[i] >= 'A' && |
1186 | ifr->ifr_name[i] <= 'Z')) |
1187 | continue; |
1188 | ifr->ifr_name[i] = '0'; |
1189 | } |
1190 | } |
1191 | |
1192 | /* |
1193 | * Look through attached interfaces for the named one. |
1194 | */ |
1195 | for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { |
1196 | struct ifnet *ifp = bp->bif_ifp; |
1197 | |
1198 | if (ifp == NULL || |
1199 | strcmp(ifp->if_xname, ifr->ifr_name) != 0) |
1200 | continue; |
1201 | /* skip additional entry */ |
1202 | if (bp->bif_driverp != &ifp->if_bpf) |
1203 | continue; |
1204 | /* |
1205 | * We found the requested interface. |
1206 | * Allocate the packet buffers if we need to. |
1207 | * If we're already attached to requested interface, |
1208 | * just flush the buffer. |
1209 | */ |
1210 | if (d->bd_sbuf == NULL) { |
1211 | error = bpf_allocbufs(d); |
1212 | if (error != 0) |
1213 | return (error); |
1214 | } |
1215 | s = splnet(); |
1216 | if (bp != d->bd_bif) { |
1217 | if (d->bd_bif) |
1218 | /* |
1219 | * Detach if attached to something else. |
1220 | */ |
1221 | bpf_detachd(d); |
1222 | |
1223 | bpf_attachd(d, bp); |
1224 | } |
1225 | reset_d(d); |
1226 | splx(s); |
1227 | return (0); |
1228 | } |
1229 | /* Not found. */ |
1230 | return (ENXIO); |
1231 | } |
1232 | |
1233 | /* |
1234 | * Copy the interface name to the ifreq. |
1235 | */ |
1236 | static void |
1237 | bpf_ifname(struct ifnet *ifp, struct ifreq *ifr) |
1238 | { |
1239 | memcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ); |
1240 | } |
1241 | |
1242 | static int |
1243 | bpf_stat(struct file *fp, struct stat *st) |
1244 | { |
1245 | struct bpf_d *d = fp->f_bpf; |
1246 | |
1247 | (void)memset(st, 0, sizeof(*st)); |
1248 | KERNEL_LOCK(1, NULL); |
1249 | st->st_dev = makedev(cdevsw_lookup_major(&bpf_cdevsw), d->bd_pid); |
1250 | st->st_atimespec = d->bd_atime; |
1251 | st->st_mtimespec = d->bd_mtime; |
1252 | st->st_ctimespec = st->st_birthtimespec = d->bd_btime; |
1253 | st->st_uid = kauth_cred_geteuid(fp->f_cred); |
1254 | st->st_gid = kauth_cred_getegid(fp->f_cred); |
1255 | st->st_mode = S_IFCHR; |
1256 | KERNEL_UNLOCK_ONE(NULL); |
1257 | return 0; |
1258 | } |
1259 | |
1260 | /* |
1261 | * Support for poll() system call |
1262 | * |
1263 | * Return true iff the specific operation will not block indefinitely - with |
1264 | * the assumption that it is safe to positively acknowledge a request for the |
1265 | * ability to write to the BPF device. |
1266 | * Otherwise, return false but make a note that a selnotify() must be done. |
1267 | */ |
1268 | static int |
1269 | bpf_poll(struct file *fp, int events) |
1270 | { |
1271 | struct bpf_d *d = fp->f_bpf; |
1272 | int s = splnet(); |
1273 | int revents; |
1274 | |
1275 | /* |
1276 | * Refresh the PID associated with this bpf file. |
1277 | */ |
1278 | KERNEL_LOCK(1, NULL); |
1279 | d->bd_pid = curproc->p_pid; |
1280 | |
1281 | revents = events & (POLLOUT | POLLWRNORM); |
1282 | if (events & (POLLIN | POLLRDNORM)) { |
1283 | /* |
1284 | * An imitation of the FIONREAD ioctl code. |
1285 | */ |
1286 | if (d->bd_hlen != 0 || |
1287 | ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) && |
1288 | d->bd_slen != 0)) { |
1289 | revents |= events & (POLLIN | POLLRDNORM); |
1290 | } else { |
1291 | selrecord(curlwp, &d->bd_sel); |
1292 | /* Start the read timeout if necessary */ |
1293 | if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) { |
1294 | callout_reset(&d->bd_callout, d->bd_rtout, |
1295 | bpf_timed_out, d); |
1296 | d->bd_state = BPF_WAITING; |
1297 | } |
1298 | } |
1299 | } |
1300 | |
1301 | KERNEL_UNLOCK_ONE(NULL); |
1302 | splx(s); |
1303 | return (revents); |
1304 | } |
1305 | |
1306 | static void |
1307 | filt_bpfrdetach(struct knote *kn) |
1308 | { |
1309 | struct bpf_d *d = kn->kn_hook; |
1310 | int s; |
1311 | |
1312 | KERNEL_LOCK(1, NULL); |
1313 | s = splnet(); |
1314 | SLIST_REMOVE(&d->bd_sel.sel_klist, kn, knote, kn_selnext); |
1315 | splx(s); |
1316 | KERNEL_UNLOCK_ONE(NULL); |
1317 | } |
1318 | |
1319 | static int |
1320 | filt_bpfread(struct knote *kn, long hint) |
1321 | { |
1322 | struct bpf_d *d = kn->kn_hook; |
1323 | int rv; |
1324 | |
1325 | KERNEL_LOCK(1, NULL); |
1326 | kn->kn_data = d->bd_hlen; |
1327 | if (d->bd_immediate) |
1328 | kn->kn_data += d->bd_slen; |
1329 | rv = (kn->kn_data > 0); |
1330 | KERNEL_UNLOCK_ONE(NULL); |
1331 | return rv; |
1332 | } |
1333 | |
1334 | static const struct filterops bpfread_filtops = |
1335 | { 1, NULL, filt_bpfrdetach, filt_bpfread }; |
1336 | |
1337 | static int |
1338 | bpf_kqfilter(struct file *fp, struct knote *kn) |
1339 | { |
1340 | struct bpf_d *d = fp->f_bpf; |
1341 | struct klist *klist; |
1342 | int s; |
1343 | |
1344 | KERNEL_LOCK(1, NULL); |
1345 | |
1346 | switch (kn->kn_filter) { |
1347 | case EVFILT_READ: |
1348 | klist = &d->bd_sel.sel_klist; |
1349 | kn->kn_fop = &bpfread_filtops; |
1350 | break; |
1351 | |
1352 | default: |
1353 | KERNEL_UNLOCK_ONE(NULL); |
1354 | return (EINVAL); |
1355 | } |
1356 | |
1357 | kn->kn_hook = d; |
1358 | |
1359 | s = splnet(); |
1360 | SLIST_INSERT_HEAD(klist, kn, kn_selnext); |
1361 | splx(s); |
1362 | KERNEL_UNLOCK_ONE(NULL); |
1363 | |
1364 | return (0); |
1365 | } |
1366 | |
1367 | /* |
1368 | * Copy data from an mbuf chain into a buffer. This code is derived |
1369 | * from m_copydata in sys/uipc_mbuf.c. |
1370 | */ |
1371 | static void * |
1372 | bpf_mcpy(void *dst_arg, const void *src_arg, size_t len) |
1373 | { |
1374 | const struct mbuf *m; |
1375 | u_int count; |
1376 | u_char *dst; |
1377 | |
1378 | m = src_arg; |
1379 | dst = dst_arg; |
1380 | while (len > 0) { |
1381 | if (m == NULL) |
1382 | panic("bpf_mcpy" ); |
1383 | count = min(m->m_len, len); |
1384 | memcpy(dst, mtod(m, const void *), count); |
1385 | m = m->m_next; |
1386 | dst += count; |
1387 | len -= count; |
1388 | } |
1389 | return dst_arg; |
1390 | } |
1391 | |
1392 | /* |
1393 | * Dispatch a packet to all the listeners on interface bp. |
1394 | * |
1395 | * pkt pointer to the packet, either a data buffer or an mbuf chain |
1396 | * buflen buffer length, if pkt is a data buffer |
1397 | * cpfn a function that can copy pkt into the listener's buffer |
1398 | * pktlen length of the packet |
1399 | * rcv true if packet came in |
1400 | */ |
1401 | static inline void |
1402 | bpf_deliver(struct bpf_if *bp, void *(*cpfn)(void *, const void *, size_t), |
1403 | void *pkt, u_int pktlen, u_int buflen, const bool rcv) |
1404 | { |
1405 | uint32_t mem[BPF_MEMWORDS]; |
1406 | bpf_args_t args = { |
1407 | .pkt = (const uint8_t *)pkt, |
1408 | .wirelen = pktlen, |
1409 | .buflen = buflen, |
1410 | .mem = mem, |
1411 | .arg = NULL |
1412 | }; |
1413 | bool gottime = false; |
1414 | struct timespec ts; |
1415 | |
1416 | /* |
1417 | * Note that the IPL does not have to be raised at this point. |
1418 | * The only problem that could arise here is that if two different |
1419 | * interfaces shared any data. This is not the case. |
1420 | */ |
1421 | for (struct bpf_d *d = bp->bif_dlist; d != NULL; d = d->bd_next) { |
1422 | u_int slen; |
1423 | |
1424 | if (!d->bd_seesent && !rcv) { |
1425 | continue; |
1426 | } |
1427 | d->bd_rcount++; |
1428 | bpf_gstats.bs_recv++; |
1429 | |
1430 | if (d->bd_jitcode) |
1431 | slen = d->bd_jitcode(NULL, &args); |
1432 | else |
1433 | slen = bpf_filter_ext(NULL, d->bd_filter, &args); |
1434 | |
1435 | if (!slen) { |
1436 | continue; |
1437 | } |
1438 | if (!gottime) { |
1439 | gottime = true; |
1440 | nanotime(&ts); |
1441 | } |
1442 | catchpacket(d, pkt, pktlen, slen, cpfn, &ts); |
1443 | } |
1444 | } |
1445 | |
1446 | /* |
1447 | * Incoming linkage from device drivers. Process the packet pkt, of length |
1448 | * pktlen, which is stored in a contiguous buffer. The packet is parsed |
1449 | * by each process' filter, and if accepted, stashed into the corresponding |
1450 | * buffer. |
1451 | */ |
1452 | static void |
1453 | _bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) |
1454 | { |
1455 | |
1456 | bpf_deliver(bp, memcpy, pkt, pktlen, pktlen, true); |
1457 | } |
1458 | |
1459 | /* |
1460 | * Incoming linkage from device drivers, when the head of the packet is in |
1461 | * a buffer, and the tail is in an mbuf chain. |
1462 | */ |
1463 | static void |
1464 | _bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) |
1465 | { |
1466 | u_int pktlen; |
1467 | struct mbuf mb; |
1468 | |
1469 | /* Skip outgoing duplicate packets. */ |
1470 | if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif_index == 0) { |
1471 | m->m_flags &= ~M_PROMISC; |
1472 | return; |
1473 | } |
1474 | |
1475 | pktlen = m_length(m) + dlen; |
1476 | |
1477 | /* |
1478 | * Craft on-stack mbuf suitable for passing to bpf_filter. |
1479 | * Note that we cut corners here; we only setup what's |
1480 | * absolutely needed--this mbuf should never go anywhere else. |
1481 | */ |
1482 | (void)memset(&mb, 0, sizeof(mb)); |
1483 | mb.m_next = m; |
1484 | mb.m_data = data; |
1485 | mb.m_len = dlen; |
1486 | |
1487 | bpf_deliver(bp, bpf_mcpy, &mb, pktlen, 0, m->m_pkthdr.rcvif_index != 0); |
1488 | } |
1489 | |
1490 | /* |
1491 | * Incoming linkage from device drivers, when packet is in an mbuf chain. |
1492 | */ |
1493 | static void |
1494 | _bpf_mtap(struct bpf_if *bp, struct mbuf *m) |
1495 | { |
1496 | void *(*cpfn)(void *, const void *, size_t); |
1497 | u_int pktlen, buflen; |
1498 | void *marg; |
1499 | |
1500 | /* Skip outgoing duplicate packets. */ |
1501 | if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif_index == 0) { |
1502 | m->m_flags &= ~M_PROMISC; |
1503 | return; |
1504 | } |
1505 | |
1506 | pktlen = m_length(m); |
1507 | |
1508 | if (pktlen == m->m_len) { |
1509 | cpfn = (void *)memcpy; |
1510 | marg = mtod(m, void *); |
1511 | buflen = pktlen; |
1512 | } else { |
1513 | cpfn = bpf_mcpy; |
1514 | marg = m; |
1515 | buflen = 0; |
1516 | } |
1517 | |
1518 | bpf_deliver(bp, cpfn, marg, pktlen, buflen, m->m_pkthdr.rcvif_index != 0); |
1519 | } |
1520 | |
1521 | /* |
1522 | * We need to prepend the address family as |
1523 | * a four byte field. Cons up a dummy header |
1524 | * to pacify bpf. This is safe because bpf |
1525 | * will only read from the mbuf (i.e., it won't |
1526 | * try to free it or keep a pointer a to it). |
1527 | */ |
1528 | static void |
1529 | _bpf_mtap_af(struct bpf_if *bp, uint32_t af, struct mbuf *m) |
1530 | { |
1531 | struct mbuf m0; |
1532 | |
1533 | m0.m_flags = 0; |
1534 | m0.m_next = m; |
1535 | m0.m_len = 4; |
1536 | m0.m_data = (char *)⁡ |
1537 | |
1538 | _bpf_mtap(bp, &m0); |
1539 | } |
1540 | |
1541 | /* |
1542 | * Put the SLIP pseudo-"link header" in place. |
1543 | * Note this M_PREPEND() should never fail, |
1544 | * swince we know we always have enough space |
1545 | * in the input buffer. |
1546 | */ |
1547 | static void |
1548 | _bpf_mtap_sl_in(struct bpf_if *bp, u_char *chdr, struct mbuf **m) |
1549 | { |
1550 | int s; |
1551 | u_char *hp; |
1552 | |
1553 | M_PREPEND(*m, SLIP_HDRLEN, M_DONTWAIT); |
1554 | if (*m == NULL) |
1555 | return; |
1556 | |
1557 | hp = mtod(*m, u_char *); |
1558 | hp[SLX_DIR] = SLIPDIR_IN; |
1559 | (void)memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN); |
1560 | |
1561 | s = splnet(); |
1562 | _bpf_mtap(bp, *m); |
1563 | splx(s); |
1564 | |
1565 | m_adj(*m, SLIP_HDRLEN); |
1566 | } |
1567 | |
1568 | /* |
1569 | * Put the SLIP pseudo-"link header" in |
1570 | * place. The compressed header is now |
1571 | * at the beginning of the mbuf. |
1572 | */ |
1573 | static void |
1574 | _bpf_mtap_sl_out(struct bpf_if *bp, u_char *chdr, struct mbuf *m) |
1575 | { |
1576 | struct mbuf m0; |
1577 | u_char *hp; |
1578 | int s; |
1579 | |
1580 | m0.m_flags = 0; |
1581 | m0.m_next = m; |
1582 | m0.m_data = m0.m_dat; |
1583 | m0.m_len = SLIP_HDRLEN; |
1584 | |
1585 | hp = mtod(&m0, u_char *); |
1586 | |
1587 | hp[SLX_DIR] = SLIPDIR_OUT; |
1588 | (void)memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN); |
1589 | |
1590 | s = splnet(); |
1591 | _bpf_mtap(bp, &m0); |
1592 | splx(s); |
1593 | m_freem(m); |
1594 | } |
1595 | |
1596 | static int |
1597 | bpf_hdrlen(struct bpf_d *d) |
1598 | { |
1599 | int hdrlen = d->bd_bif->bif_hdrlen; |
1600 | /* |
1601 | * Compute the length of the bpf header. This is not necessarily |
1602 | * equal to SIZEOF_BPF_HDR because we want to insert spacing such |
1603 | * that the network layer header begins on a longword boundary (for |
1604 | * performance reasons and to alleviate alignment restrictions). |
1605 | */ |
1606 | #ifdef _LP64 |
1607 | if (d->bd_compat32) |
1608 | return (BPF_WORDALIGN32(hdrlen + SIZEOF_BPF_HDR32) - hdrlen); |
1609 | else |
1610 | #endif |
1611 | return (BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen); |
1612 | } |
1613 | |
1614 | /* |
1615 | * Move the packet data from interface memory (pkt) into the |
1616 | * store buffer. Call the wakeup functions if it's time to wakeup |
1617 | * a listener (buffer full), "cpfn" is the routine called to do the |
1618 | * actual data transfer. memcpy is passed in to copy contiguous chunks, |
1619 | * while bpf_mcpy is passed in to copy mbuf chains. In the latter case, |
1620 | * pkt is really an mbuf. |
1621 | */ |
1622 | static void |
1623 | catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, |
1624 | void *(*cpfn)(void *, const void *, size_t), struct timespec *ts) |
1625 | { |
1626 | char *h; |
1627 | int totlen, curlen, caplen; |
1628 | int hdrlen = bpf_hdrlen(d); |
1629 | int do_wakeup = 0; |
1630 | |
1631 | ++d->bd_ccount; |
1632 | ++bpf_gstats.bs_capt; |
1633 | /* |
1634 | * Figure out how many bytes to move. If the packet is |
1635 | * greater or equal to the snapshot length, transfer that |
1636 | * much. Otherwise, transfer the whole packet (unless |
1637 | * we hit the buffer size limit). |
1638 | */ |
1639 | totlen = hdrlen + min(snaplen, pktlen); |
1640 | if (totlen > d->bd_bufsize) |
1641 | totlen = d->bd_bufsize; |
1642 | /* |
1643 | * If we adjusted totlen to fit the bufsize, it could be that |
1644 | * totlen is smaller than hdrlen because of the link layer header. |
1645 | */ |
1646 | caplen = totlen - hdrlen; |
1647 | if (caplen < 0) |
1648 | caplen = 0; |
1649 | |
1650 | /* |
1651 | * Round up the end of the previous packet to the next longword. |
1652 | */ |
1653 | #ifdef _LP64 |
1654 | if (d->bd_compat32) |
1655 | curlen = BPF_WORDALIGN32(d->bd_slen); |
1656 | else |
1657 | #endif |
1658 | curlen = BPF_WORDALIGN(d->bd_slen); |
1659 | if (curlen + totlen > d->bd_bufsize) { |
1660 | /* |
1661 | * This packet will overflow the storage buffer. |
1662 | * Rotate the buffers if we can, then wakeup any |
1663 | * pending reads. |
1664 | */ |
1665 | if (d->bd_fbuf == NULL) { |
1666 | /* |
1667 | * We haven't completed the previous read yet, |
1668 | * so drop the packet. |
1669 | */ |
1670 | ++d->bd_dcount; |
1671 | ++bpf_gstats.bs_drop; |
1672 | return; |
1673 | } |
1674 | ROTATE_BUFFERS(d); |
1675 | do_wakeup = 1; |
1676 | curlen = 0; |
1677 | } else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) { |
1678 | /* |
1679 | * Immediate mode is set, or the read timeout has |
1680 | * already expired during a select call. A packet |
1681 | * arrived, so the reader should be woken up. |
1682 | */ |
1683 | do_wakeup = 1; |
1684 | } |
1685 | |
1686 | /* |
1687 | * Append the bpf header. |
1688 | */ |
1689 | h = (char *)d->bd_sbuf + curlen; |
1690 | #ifdef _LP64 |
1691 | if (d->bd_compat32) { |
1692 | struct bpf_hdr32 *hp32; |
1693 | |
1694 | hp32 = (struct bpf_hdr32 *)h; |
1695 | hp32->bh_tstamp.tv_sec = ts->tv_sec; |
1696 | hp32->bh_tstamp.tv_usec = ts->tv_nsec / 1000; |
1697 | hp32->bh_datalen = pktlen; |
1698 | hp32->bh_hdrlen = hdrlen; |
1699 | hp32->bh_caplen = caplen; |
1700 | } else |
1701 | #endif |
1702 | { |
1703 | struct bpf_hdr *hp; |
1704 | |
1705 | hp = (struct bpf_hdr *)h; |
1706 | hp->bh_tstamp.tv_sec = ts->tv_sec; |
1707 | hp->bh_tstamp.tv_usec = ts->tv_nsec / 1000; |
1708 | hp->bh_datalen = pktlen; |
1709 | hp->bh_hdrlen = hdrlen; |
1710 | hp->bh_caplen = caplen; |
1711 | } |
1712 | |
1713 | /* |
1714 | * Copy the packet data into the store buffer and update its length. |
1715 | */ |
1716 | (*cpfn)(h + hdrlen, pkt, caplen); |
1717 | d->bd_slen = curlen + totlen; |
1718 | |
1719 | /* |
1720 | * Call bpf_wakeup after bd_slen has been updated so that kevent(2) |
1721 | * will cause filt_bpfread() to be called with it adjusted. |
1722 | */ |
1723 | if (do_wakeup) |
1724 | bpf_wakeup(d); |
1725 | } |
1726 | |
1727 | /* |
1728 | * Initialize all nonzero fields of a descriptor. |
1729 | */ |
1730 | static int |
1731 | bpf_allocbufs(struct bpf_d *d) |
1732 | { |
1733 | |
1734 | d->bd_fbuf = malloc(d->bd_bufsize, M_DEVBUF, M_NOWAIT); |
1735 | if (!d->bd_fbuf) |
1736 | return (ENOBUFS); |
1737 | d->bd_sbuf = malloc(d->bd_bufsize, M_DEVBUF, M_NOWAIT); |
1738 | if (!d->bd_sbuf) { |
1739 | free(d->bd_fbuf, M_DEVBUF); |
1740 | return (ENOBUFS); |
1741 | } |
1742 | d->bd_slen = 0; |
1743 | d->bd_hlen = 0; |
1744 | return (0); |
1745 | } |
1746 | |
1747 | /* |
1748 | * Free buffers currently in use by a descriptor. |
1749 | * Called on close. |
1750 | */ |
1751 | static void |
1752 | bpf_freed(struct bpf_d *d) |
1753 | { |
1754 | /* |
1755 | * We don't need to lock out interrupts since this descriptor has |
1756 | * been detached from its interface and it yet hasn't been marked |
1757 | * free. |
1758 | */ |
1759 | if (d->bd_sbuf != NULL) { |
1760 | free(d->bd_sbuf, M_DEVBUF); |
1761 | if (d->bd_hbuf != NULL) |
1762 | free(d->bd_hbuf, M_DEVBUF); |
1763 | if (d->bd_fbuf != NULL) |
1764 | free(d->bd_fbuf, M_DEVBUF); |
1765 | } |
1766 | if (d->bd_filter) |
1767 | free(d->bd_filter, M_DEVBUF); |
1768 | |
1769 | if (d->bd_jitcode != NULL) { |
1770 | bpf_jit_freecode(d->bd_jitcode); |
1771 | } |
1772 | } |
1773 | |
1774 | /* |
1775 | * Attach an interface to bpf. dlt is the link layer type; |
1776 | * hdrlen is the fixed size of the link header for the specified dlt |
1777 | * (variable length headers not yet supported). |
1778 | */ |
1779 | static void |
1780 | _bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) |
1781 | { |
1782 | struct bpf_if *bp; |
1783 | bp = malloc(sizeof(*bp), M_DEVBUF, M_DONTWAIT); |
1784 | if (bp == NULL) |
1785 | panic("bpfattach" ); |
1786 | |
1787 | mutex_enter(&bpf_mtx); |
1788 | bp->bif_dlist = NULL; |
1789 | bp->bif_driverp = driverp; |
1790 | bp->bif_ifp = ifp; |
1791 | bp->bif_dlt = dlt; |
1792 | |
1793 | bp->bif_next = bpf_iflist; |
1794 | bpf_iflist = bp; |
1795 | |
1796 | *bp->bif_driverp = NULL; |
1797 | |
1798 | bp->bif_hdrlen = hdrlen; |
1799 | mutex_exit(&bpf_mtx); |
1800 | #if 0 |
1801 | printf("bpf: %s attached\n" , ifp->if_xname); |
1802 | #endif |
1803 | } |
1804 | |
1805 | /* |
1806 | * Remove an interface from bpf. |
1807 | */ |
1808 | static void |
1809 | _bpfdetach(struct ifnet *ifp) |
1810 | { |
1811 | struct bpf_if *bp, **pbp; |
1812 | struct bpf_d *d; |
1813 | int s; |
1814 | |
1815 | mutex_enter(&bpf_mtx); |
1816 | /* Nuke the vnodes for any open instances */ |
1817 | LIST_FOREACH(d, &bpf_list, bd_list) { |
1818 | if (d->bd_bif != NULL && d->bd_bif->bif_ifp == ifp) { |
1819 | /* |
1820 | * Detach the descriptor from an interface now. |
1821 | * It will be free'ed later by close routine. |
1822 | */ |
1823 | s = splnet(); |
1824 | d->bd_promisc = 0; /* we can't touch device. */ |
1825 | bpf_detachd(d); |
1826 | splx(s); |
1827 | } |
1828 | } |
1829 | |
1830 | again: |
1831 | for (bp = bpf_iflist, pbp = &bpf_iflist; |
1832 | bp != NULL; pbp = &bp->bif_next, bp = bp->bif_next) { |
1833 | if (bp->bif_ifp == ifp) { |
1834 | *pbp = bp->bif_next; |
1835 | free(bp, M_DEVBUF); |
1836 | goto again; |
1837 | } |
1838 | } |
1839 | mutex_exit(&bpf_mtx); |
1840 | } |
1841 | |
1842 | /* |
1843 | * Change the data link type of a interface. |
1844 | */ |
1845 | static void |
1846 | _bpf_change_type(struct ifnet *ifp, u_int dlt, u_int hdrlen) |
1847 | { |
1848 | struct bpf_if *bp; |
1849 | |
1850 | for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { |
1851 | if (bp->bif_driverp == &ifp->if_bpf) |
1852 | break; |
1853 | } |
1854 | if (bp == NULL) |
1855 | panic("bpf_change_type" ); |
1856 | |
1857 | bp->bif_dlt = dlt; |
1858 | |
1859 | bp->bif_hdrlen = hdrlen; |
1860 | } |
1861 | |
1862 | /* |
1863 | * Get a list of available data link type of the interface. |
1864 | */ |
1865 | static int |
1866 | bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl) |
1867 | { |
1868 | int n, error; |
1869 | struct ifnet *ifp; |
1870 | struct bpf_if *bp; |
1871 | |
1872 | ifp = d->bd_bif->bif_ifp; |
1873 | n = 0; |
1874 | error = 0; |
1875 | for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { |
1876 | if (bp->bif_ifp != ifp) |
1877 | continue; |
1878 | if (bfl->bfl_list != NULL) { |
1879 | if (n >= bfl->bfl_len) |
1880 | return ENOMEM; |
1881 | error = copyout(&bp->bif_dlt, |
1882 | bfl->bfl_list + n, sizeof(u_int)); |
1883 | } |
1884 | n++; |
1885 | } |
1886 | bfl->bfl_len = n; |
1887 | return error; |
1888 | } |
1889 | |
1890 | /* |
1891 | * Set the data link type of a BPF instance. |
1892 | */ |
1893 | static int |
1894 | bpf_setdlt(struct bpf_d *d, u_int dlt) |
1895 | { |
1896 | int s, error, opromisc; |
1897 | struct ifnet *ifp; |
1898 | struct bpf_if *bp; |
1899 | |
1900 | KASSERT(mutex_owned(&bpf_mtx)); |
1901 | |
1902 | if (d->bd_bif->bif_dlt == dlt) |
1903 | return 0; |
1904 | ifp = d->bd_bif->bif_ifp; |
1905 | for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) { |
1906 | if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) |
1907 | break; |
1908 | } |
1909 | if (bp == NULL) |
1910 | return EINVAL; |
1911 | s = splnet(); |
1912 | opromisc = d->bd_promisc; |
1913 | bpf_detachd(d); |
1914 | bpf_attachd(d, bp); |
1915 | reset_d(d); |
1916 | if (opromisc) { |
1917 | error = ifpromisc(bp->bif_ifp, 1); |
1918 | if (error) |
1919 | printf("%s: bpf_setdlt: ifpromisc failed (%d)\n" , |
1920 | bp->bif_ifp->if_xname, error); |
1921 | else |
1922 | d->bd_promisc = 1; |
1923 | } |
1924 | splx(s); |
1925 | return 0; |
1926 | } |
1927 | |
1928 | static int |
1929 | sysctl_net_bpf_maxbufsize(SYSCTLFN_ARGS) |
1930 | { |
1931 | int newsize, error; |
1932 | struct sysctlnode node; |
1933 | |
1934 | node = *rnode; |
1935 | node.sysctl_data = &newsize; |
1936 | newsize = bpf_maxbufsize; |
1937 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
1938 | if (error || newp == NULL) |
1939 | return (error); |
1940 | |
1941 | if (newsize < BPF_MINBUFSIZE || newsize > BPF_MAXBUFSIZE) |
1942 | return (EINVAL); |
1943 | |
1944 | bpf_maxbufsize = newsize; |
1945 | |
1946 | return (0); |
1947 | } |
1948 | |
1949 | #if defined(MODULAR) || defined(BPFJIT) |
1950 | static int |
1951 | sysctl_net_bpf_jit(SYSCTLFN_ARGS) |
1952 | { |
1953 | bool newval; |
1954 | int error; |
1955 | struct sysctlnode node; |
1956 | |
1957 | node = *rnode; |
1958 | node.sysctl_data = &newval; |
1959 | newval = bpf_jit; |
1960 | error = sysctl_lookup(SYSCTLFN_CALL(&node)); |
1961 | if (error != 0 || newp == NULL) |
1962 | return error; |
1963 | |
1964 | bpf_jit = newval; |
1965 | |
1966 | /* |
1967 | * Do a full sync to publish new bpf_jit value and |
1968 | * update bpfjit_module_ops.bj_generate_code variable. |
1969 | */ |
1970 | membar_sync(); |
1971 | |
1972 | if (newval && bpfjit_module_ops.bj_generate_code == NULL) { |
1973 | printf("JIT compilation is postponed " |
1974 | "until after bpfjit module is loaded\n" ); |
1975 | } |
1976 | |
1977 | return 0; |
1978 | } |
1979 | #endif |
1980 | |
1981 | static int |
1982 | sysctl_net_bpf_peers(SYSCTLFN_ARGS) |
1983 | { |
1984 | int error, elem_count; |
1985 | struct bpf_d *dp; |
1986 | struct bpf_d_ext dpe; |
1987 | size_t len, needed, elem_size, out_size; |
1988 | char *sp; |
1989 | |
1990 | if (namelen == 1 && name[0] == CTL_QUERY) |
1991 | return (sysctl_query(SYSCTLFN_CALL(rnode))); |
1992 | |
1993 | if (namelen != 2) |
1994 | return (EINVAL); |
1995 | |
1996 | /* BPF peers is privileged information. */ |
1997 | error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE, |
1998 | KAUTH_REQ_NETWORK_INTERFACE_GETPRIV, NULL, NULL, NULL); |
1999 | if (error) |
2000 | return (EPERM); |
2001 | |
2002 | len = (oldp != NULL) ? *oldlenp : 0; |
2003 | sp = oldp; |
2004 | elem_size = name[0]; |
2005 | elem_count = name[1]; |
2006 | out_size = MIN(sizeof(dpe), elem_size); |
2007 | needed = 0; |
2008 | |
2009 | if (elem_size < 1 || elem_count < 0) |
2010 | return (EINVAL); |
2011 | |
2012 | mutex_enter(&bpf_mtx); |
2013 | LIST_FOREACH(dp, &bpf_list, bd_list) { |
2014 | if (len >= elem_size && elem_count > 0) { |
2015 | #define BPF_EXT(field) dpe.bde_ ## field = dp->bd_ ## field |
2016 | BPF_EXT(bufsize); |
2017 | BPF_EXT(promisc); |
2018 | BPF_EXT(state); |
2019 | BPF_EXT(immediate); |
2020 | BPF_EXT(hdrcmplt); |
2021 | BPF_EXT(seesent); |
2022 | BPF_EXT(pid); |
2023 | BPF_EXT(rcount); |
2024 | BPF_EXT(dcount); |
2025 | BPF_EXT(ccount); |
2026 | #undef BPF_EXT |
2027 | if (dp->bd_bif) |
2028 | (void)strlcpy(dpe.bde_ifname, |
2029 | dp->bd_bif->bif_ifp->if_xname, |
2030 | IFNAMSIZ - 1); |
2031 | else |
2032 | dpe.bde_ifname[0] = '\0'; |
2033 | |
2034 | error = copyout(&dpe, sp, out_size); |
2035 | if (error) |
2036 | break; |
2037 | sp += elem_size; |
2038 | len -= elem_size; |
2039 | } |
2040 | needed += elem_size; |
2041 | if (elem_count > 0 && elem_count != INT_MAX) |
2042 | elem_count--; |
2043 | } |
2044 | mutex_exit(&bpf_mtx); |
2045 | |
2046 | *oldlenp = needed; |
2047 | |
2048 | return (error); |
2049 | } |
2050 | |
2051 | static struct sysctllog *bpf_sysctllog; |
2052 | static void |
2053 | sysctl_net_bpf_setup(void) |
2054 | { |
2055 | const struct sysctlnode *node; |
2056 | |
2057 | node = NULL; |
2058 | sysctl_createv(&bpf_sysctllog, 0, NULL, &node, |
2059 | CTLFLAG_PERMANENT, |
2060 | CTLTYPE_NODE, "bpf" , |
2061 | SYSCTL_DESCR("BPF options" ), |
2062 | NULL, 0, NULL, 0, |
2063 | CTL_NET, CTL_CREATE, CTL_EOL); |
2064 | if (node != NULL) { |
2065 | #if defined(MODULAR) || defined(BPFJIT) |
2066 | sysctl_createv(&bpf_sysctllog, 0, NULL, NULL, |
2067 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
2068 | CTLTYPE_BOOL, "jit" , |
2069 | SYSCTL_DESCR("Toggle Just-In-Time compilation" ), |
2070 | sysctl_net_bpf_jit, 0, &bpf_jit, 0, |
2071 | CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL); |
2072 | #endif |
2073 | sysctl_createv(&bpf_sysctllog, 0, NULL, NULL, |
2074 | CTLFLAG_PERMANENT|CTLFLAG_READWRITE, |
2075 | CTLTYPE_INT, "maxbufsize" , |
2076 | SYSCTL_DESCR("Maximum size for data capture buffer" ), |
2077 | sysctl_net_bpf_maxbufsize, 0, &bpf_maxbufsize, 0, |
2078 | CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL); |
2079 | sysctl_createv(&bpf_sysctllog, 0, NULL, NULL, |
2080 | CTLFLAG_PERMANENT, |
2081 | CTLTYPE_STRUCT, "stats" , |
2082 | SYSCTL_DESCR("BPF stats" ), |
2083 | NULL, 0, &bpf_gstats, sizeof(bpf_gstats), |
2084 | CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL); |
2085 | sysctl_createv(&bpf_sysctllog, 0, NULL, NULL, |
2086 | CTLFLAG_PERMANENT, |
2087 | CTLTYPE_STRUCT, "peers" , |
2088 | SYSCTL_DESCR("BPF peers" ), |
2089 | sysctl_net_bpf_peers, 0, NULL, 0, |
2090 | CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL); |
2091 | } |
2092 | |
2093 | } |
2094 | |
2095 | struct bpf_ops bpf_ops_kernel = { |
2096 | .bpf_attach = _bpfattach, |
2097 | .bpf_detach = _bpfdetach, |
2098 | .bpf_change_type = _bpf_change_type, |
2099 | |
2100 | .bpf_tap = _bpf_tap, |
2101 | .bpf_mtap = _bpf_mtap, |
2102 | .bpf_mtap2 = _bpf_mtap2, |
2103 | .bpf_mtap_af = _bpf_mtap_af, |
2104 | .bpf_mtap_sl_in = _bpf_mtap_sl_in, |
2105 | .bpf_mtap_sl_out = _bpf_mtap_sl_out, |
2106 | }; |
2107 | |
2108 | MODULE(MODULE_CLASS_DRIVER, bpf, "bpf_filter" ); |
2109 | |
2110 | static int |
2111 | bpf_modcmd(modcmd_t cmd, void *arg) |
2112 | { |
2113 | #ifdef _MODULE |
2114 | devmajor_t bmajor, cmajor; |
2115 | #endif |
2116 | int error = 0; |
2117 | |
2118 | switch (cmd) { |
2119 | case MODULE_CMD_INIT: |
2120 | bpf_init(); |
2121 | #ifdef _MODULE |
2122 | bmajor = cmajor = NODEVMAJOR; |
2123 | error = devsw_attach("bpf" , NULL, &bmajor, |
2124 | &bpf_cdevsw, &cmajor); |
2125 | if (error) |
2126 | break; |
2127 | #endif |
2128 | |
2129 | bpf_ops_handover_enter(&bpf_ops_kernel); |
2130 | atomic_swap_ptr(&bpf_ops, &bpf_ops_kernel); |
2131 | bpf_ops_handover_exit(); |
2132 | sysctl_net_bpf_setup(); |
2133 | break; |
2134 | |
2135 | case MODULE_CMD_FINI: |
2136 | /* |
2137 | * While there is no reference counting for bpf callers, |
2138 | * unload could at least in theory be done similarly to |
2139 | * system call disestablishment. This should even be |
2140 | * a little simpler: |
2141 | * |
2142 | * 1) replace op vector with stubs |
2143 | * 2) post update to all cpus with xc |
2144 | * 3) check that nobody is in bpf anymore |
2145 | * (it's doubtful we'd want something like l_sysent, |
2146 | * but we could do something like *signed* percpu |
2147 | * counters. if the sum is 0, we're good). |
2148 | * 4) if fail, unroll changes |
2149 | * |
2150 | * NOTE: change won't be atomic to the outside. some |
2151 | * packets may be not captured even if unload is |
2152 | * not succesful. I think packet capture not working |
2153 | * is a perfectly logical consequence of trying to |
2154 | * disable packet capture. |
2155 | */ |
2156 | error = EOPNOTSUPP; |
2157 | /* insert sysctl teardown */ |
2158 | break; |
2159 | |
2160 | default: |
2161 | error = ENOTTY; |
2162 | break; |
2163 | } |
2164 | |
2165 | return error; |
2166 | } |
2167 | |