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1.1 root 1: /*-
2: * Copyright (c) 1991 The Regents of the University of California.
3: * All rights reserved.
4: *
5: * This code is derived from the Stanford/CMU enet packet filter,
6: * (net/enet.c) distributed as part of 4.3BSD, and code contributed
7: * to Berkeley by Steven McCanne of Lawrence Berkeley Laboratory.
8: *
9: * Redistribution and use in source and binary forms, with or without
10: * modification, are permitted provided that the following conditions
11: * are met:
12: * 1. Redistributions of source code must retain the above copyright
13: * notice, this list of conditions and the following disclaimer.
14: * 2. Redistributions in binary form must reproduce the above copyright
15: * notice, this list of conditions and the following disclaimer in the
16: * documentation and/or other materials provided with the distribution.
17: * 3. All advertising materials mentioning features or use of this software
18: * must display the following acknowledgement:
19: * This product includes software developed by the University of
20: * California, Berkeley and its contributors.
21: * 4. Neither the name of the University nor the names of its contributors
22: * may be used to endorse or promote products derived from this software
23: * without specific prior written permission.
24: *
25: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35: * SUCH DAMAGE.
36: *
37: * @(#)bpf.c 7.4 (Berkeley) 6/17/91
38: *
39: * static char rcsid[] =
1.1.1.2 ! root 40: * "$Header: /usr/bill/working/sys/net/RCS/bpf.c,v 1.1 92/01/15 20:28:02 william Exp Locker: william $";
1.1 root 41: */
42:
43: #include "bpfilter.h"
44:
45: #if (NBPFILTER > 0)
46:
47: #include <sys/param.h>
48: #include <sys/systm.h>
49: #include <sys/mbuf.h>
50: #include <sys/buf.h>
51: #include <sys/dir.h>
52: #include <sys/proc.h>
53: #include <sys/user.h>
54: #include <sys/ioctl.h>
55:
56: #include <sys/file.h>
57: #ifdef sparc
58: #include <sys/stream.h>
59: #endif
60: #include <sys/tty.h>
61: #include <sys/uio.h>
62:
63: #include <sys/protosw.h>
64: #include <sys/socket.h>
65: #include <net/if.h>
66:
67: #include <net/bpf.h>
68: #include <net/bpfdesc.h>
69:
70: #include <sys/errno.h>
71:
72: #include <netinet/in.h>
73: #include <netinet/if_ether.h>
74: #include <sys/kernel.h>
75:
76: #define PRINET 26 /* interruptible */
77:
78: /*
79: * The default read buffer size is patchable.
80: */
81: int bpf_bufsize = MCLBYTES;
82:
83: /*
84: * bpf_iflist is the list of interfaces; each corresponds to an ifnet
85: * bpf_dtab holds the descriptors, indexed by minor device #
86: *
87: * We really don't need NBPFILTER bpf_if entries, but this eliminates
88: * the need to account for all possible drivers here.
89: * This problem will go away when these structures are allocated dynamically.
90: */
91: static struct bpf_if *bpf_iflist;
92: static struct bpf_d bpf_dtab[NBPFILTER];
93:
94: static void bpf_ifname();
95: static void catchpacket();
96: static int bpf_setif();
97: static int bpf_initd();
98:
99: static int
100: bpf_movein(uio, linktype, mp, sockp)
101: register struct uio *uio;
102: int linktype;
103: register struct mbuf **mp;
104: register struct sockaddr *sockp;
105: {
106: struct mbuf *m;
107: int error;
108: int len;
109: int hlen;
110:
111: /*
112: * Build a sockaddr based on the data link layer type.
113: * We do this at this level because the ethernet header
114: * is copied directly into the data field of the sockaddr.
115: * In the case of SLIP, there is no header and the packet
116: * is forwarded as is.
117: * Also, we are careful to leave room at the front of the mbuf
118: * for the link level header.
119: */
120: switch (linktype) {
121: case DLT_SLIP:
122: sockp->sa_family = AF_INET;
123: hlen = 0;
124: break;
125:
126: case DLT_EN10MB:
127: sockp->sa_family = AF_UNSPEC;
128: /* XXX Would MAXLINKHDR be better? */
129: hlen = sizeof(struct ether_header);
130: break;
131:
132: case DLT_FDDI:
133: sockp->sa_family = AF_UNSPEC;
134: /* XXX 4(FORMAC)+6(dst)+6(src)+3(LLC)+5(SNAP) */
135: hlen = 24;
136: break;
137:
138: default:
139: return (EIO);
140: }
141:
142: len = uio->uio_resid;
143: if ((unsigned)len > MCLBYTES)
144: return (EIO);
145:
146: MGET(m, M_WAIT, MT_DATA);
147: if (m == 0)
148: return (ENOBUFS);
149: if (len > MLEN) {
150: MCLGET(m, M_WAIT);
151: if ((m->m_flags & M_EXT) == 0) {
152: error = ENOBUFS;
153: goto bad;
154: }
155: }
156: m->m_len = len;
157: *mp = m;
158: /*
159: * Make room for link header.
160: */
161: if (hlen) {
162: m->m_len -= hlen;
163: m->m_data += hlen; /* XXX */
164:
165: error = uiomove((caddr_t)sockp->sa_data, hlen, uio);
166: if (error)
167: goto bad;
168: }
169: error = uiomove(mtod(m, caddr_t), len - hlen, uio);
170: if (!error)
171: return (0);
172: bad:
173: m_freem(m);
174: return (error);
175: }
176:
177: /*
178: * Attach 'd' to the bpf interface 'bp', i.e. make 'd' listen on 'bp'.
179: * Must be called at splimp.
180: */
181: static void
182: bpf_attachd(d, bp)
183: struct bpf_d *d;
184: struct bpf_if *bp;
185: {
186: /* Point d at bp. */
187: d->bd_bif = bp;
188:
189: /* Add d to bp's list of listeners. */
190: d->bd_next = bp->bif_dlist;
191: bp->bif_dlist = d;
192:
193: /*
194: * Let the driver know we're here (if it doesn't already).
195: */
196: *bp->bif_driverp = bp;
197: }
198:
199: static void
200: bpf_detachd(d)
201: struct bpf_d *d;
202: {
203: struct bpf_d **p;
204: struct bpf_if *bp;
205:
206: bp = d->bd_bif;
207: /*
208: * Check if this descriptor had requested promiscuous mode.
209: * If so, turn it off.
210: */
211: if (d->bd_promisc) {
212: d->bd_promisc = 0;
213: if (ifpromisc(bp->bif_ifp, 0))
214: /*
215: * Something is really wrong if we were able to put
216: * the driver into promiscuous mode, but can't
217: * take it out.
218: */
219: panic("bpf_detachd: ifpromisc failed");
220: }
221: /* Remove 'd' from the interface's descriptor list. */
222: p = &bp->bif_dlist;
223: while (*p != d) {
224: p = &(*p)->bd_next;
225: if (*p == 0)
226: panic("bpf_detachd: descriptor not in list");
227: }
228: *p = (*p)->bd_next;
229: if (bp->bif_dlist == 0)
230: /*
231: * Let the driver know that there are no more listeners.
232: */
233: *d->bd_bif->bif_driverp = 0;
234: d->bd_bif = 0;
235: }
236:
237:
238: /*
239: * Mark a descriptor free by making it point to itself.
240: * This is probably cheaper than marking with a constant since
241: * the address should be in a register anyway.
242: */
243: #define D_ISFREE(d) ((d) == (d)->bd_next)
244: #define D_MARKFREE(d) ((d)->bd_next = (d))
245: #define D_MARKUSED(d) ((d)->bd_next = 0)
246:
247: /*
248: * bpfopen - open ethernet device
249: *
250: * Errors: ENXIO - illegal minor device number
251: * EBUSY - too many files open
252: */
253: /* ARGSUSED */
254: int
255: bpfopen(dev, flag)
256: dev_t dev;
257: int flag;
258: {
259: int error, s;
260: register struct bpf_d *d;
261:
262: if (minor(dev) >= NBPFILTER)
263: return (ENXIO);
264:
265: /*
266: * Each minor can be opened by only one process. If the requested
267: * minor is in use, return EBUSY.
268: */
269: s = splimp();
270: d = &bpf_dtab[minor(dev)];
271: if (!D_ISFREE(d)) {
272: splx(s);
273: return (EBUSY);
274: } else
275: /* Mark "free" and do most initialization. */
276: bzero((char *)d, sizeof(*d));
277: splx(s);
278:
279: error = bpf_initd(d);
280: if (error) {
281: D_MARKFREE(d);
282: return (error);
283: }
284: return (0);
285: }
286:
287: /*
288: * Close the descriptor by detaching it from its interface,
289: * deallocating its buffers, and marking it free.
290: */
291: /* ARGSUSED */
292: bpfclose(dev, flag)
293: dev_t dev;
294: int flag;
295: {
296: register struct bpf_d *d = &bpf_dtab[minor(dev)];
297: int s;
298:
299: s = splimp();
300: if (d->bd_bif)
301: bpf_detachd(d);
302: splx(s);
303:
304: /* Free the buffer space. */
305: if (d->bd_hbuf)
306: free(d->bd_hbuf, M_DEVBUF);
307: if (d->bd_fbuf)
308: free(d->bd_fbuf, M_DEVBUF);
309: free(d->bd_sbuf, M_DEVBUF);
310: if (d->bd_filter)
311: free((caddr_t)d->bd_filter, M_DEVBUF);
312:
313: D_MARKFREE(d);
314: }
315:
316: /*
317: * Rotate the packet buffers in descriptor d. Move the store buffer
318: * into the hold slot, and the free buffer into the store slot.
319: * Zero the length of the new store buffer.
320: */
321: #define ROTATE_BUFFERS(d) \
322: (d)->bd_hbuf = (d)->bd_sbuf; \
323: (d)->bd_hlen = (d)->bd_slen; \
324: (d)->bd_sbuf = (d)->bd_fbuf; \
325: (d)->bd_slen = 0; \
326: (d)->bd_fbuf = 0;
327: /*
328: * bpfread - read next chunk of packets from buffers
329: */
330: int
331: bpfread(dev, uio)
332: dev_t dev;
333: register struct uio *uio;
334: {
335: register struct bpf_d *d = &bpf_dtab[minor(dev)];
336: int error;
337: int s;
338:
339: /*
340: * Restrict application to use a buffer the same size as
341: * as kernel buffers.
342: */
343: if (uio->uio_resid != d->bd_bufsize)
344: return (EINVAL);
345:
346: s = splimp();
347: /*
348: * If the hold buffer is empty, then set a timer and sleep
349: * until either the timeout has occurred or enough packets have
350: * arrived to fill the store buffer.
351: */
352: while (d->bd_hbuf == 0) {
353: if (d->bd_immediate && d->bd_slen != 0) {
354: /*
355: * A packet(s) either arrived since the previous
356: * read or arrived while we were asleep.
357: * Rotate the buffers and return what's here.
358: */
359: ROTATE_BUFFERS(d);
360: break;
361: }
362: error = tsleep((caddr_t)d, PRINET|PCATCH, "bpf", d->bd_rtout);
363: if (error == EINTR || error == ERESTART) {
364: splx(s);
365: return (error);
366: }
367: if (error == EWOULDBLOCK) {
368: /*
369: * On a timeout, return what's in the buffer,
370: * which may be nothing. If there is something
371: * in the store buffer, we can rotate the buffers.
372: */
373: if (d->bd_hbuf)
374: /*
375: * We filled up the buffer in between
376: * getting the timeout and arriving
377: * here, so we don't need to rotate.
378: */
379: break;
380:
381: if (d->bd_slen == 0) {
382: splx(s);
383: return (0);
384: }
385: ROTATE_BUFFERS(d);
386: break;
387: }
388: }
389: /*
390: * At this point, we know we have something in the hold slot.
391: */
392: splx(s);
393:
394: /*
395: * Move data from hold buffer into user space.
396: * We know the entire buffer is transferred since
397: * we checked above that the read buffer is bpf_bufsize bytes.
398: */
399: error = uiomove(d->bd_hbuf, d->bd_hlen, uio);
400:
401: s = splimp();
402: d->bd_fbuf = d->bd_hbuf;
403: d->bd_hbuf = 0;
404: splx(s);
405:
406: return (error);
407: }
408:
409:
410: /*
411: * If there are processes sleeping on this descriptor, wake them up.
412: */
413: static inline void
414: bpf_wakeup(d)
415: register struct bpf_d *d;
416: {
417: wakeup((caddr_t)d);
418: if (d->bd_selproc) {
419: selwakeup(d->bd_selproc, (int)d->bd_selcoll);
420: d->bd_selcoll = 0;
421: d->bd_selproc = 0;
422: }
423: }
424:
425: int
426: bpfwrite(dev, uio)
427: dev_t dev;
428: struct uio *uio;
429: {
430: register struct bpf_d *d = &bpf_dtab[minor(dev)];
431: struct ifnet *ifp;
432: struct mbuf *m;
433: int error, s;
434: static struct sockaddr dst;
435:
436: if (d->bd_bif == 0)
437: return (ENXIO);
438:
439: ifp = d->bd_bif->bif_ifp;
440:
441: if (uio->uio_resid == 0)
442: return (0);
443: if (uio->uio_resid > ifp->if_mtu)
444: return (EMSGSIZE);
445:
446: error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst);
447: if (error)
448: return (error);
449:
450: s = splnet();
451: error = (*ifp->if_output)(ifp, m, &dst);
452: splx(s);
453: /*
454: * The driver frees the mbuf.
455: */
456: return (error);
457: }
458:
459: /*
460: * Reset a descriptor by flushing its packet bufferand clearing the receive
461: * and drop counts. Should be called at splimp.
462: */
463: static void
464: reset_d(d)
465: struct bpf_d *d;
466: {
467: if (d->bd_hbuf) {
468: /* Free the hold buffer. */
469: d->bd_fbuf = d->bd_hbuf;
470: d->bd_hbuf = 0;
471: }
472: d->bd_slen = 0;
473: d->bd_rcount = 0;
474: d->bd_dcount = 0;
475: }
476:
477: /*
478: * FIONREAD Check for read packet available.
479: * SIOCGIFADDR Get interface address - convenient hook to driver.
480: * BIOCGFLEN Get max filter len.
481: * BIOCGBLEN Get buffer len [for read()].
482: * BIOCSETF Set ethernet read filter.
483: * BIOCFLUSH Flush read packet buffer.
484: * BIOCPROMISC Put interface into promiscuous mode.
485: * BIOCGDLT Get link layer type.
486: * BIOCGETIF Get interface name.
487: * BIOCSETIF Set interface.
488: * BIOCSRTIMEOUT Set read timeout.
489: * BIOCGRTIMEOUT Get read timeout.
490: * BIOCGSTATS Get packet stats.
491: * BIOCIMMEDIATE Set immediate mode.
492: */
493: /* ARGSUSED */
494: int
495: bpfioctl(dev, cmd, addr, flag)
496: dev_t dev;
497: int cmd;
498: caddr_t addr;
499: int flag;
500: {
501: register struct bpf_d *d = &bpf_dtab[minor(dev)];
502: int s, error = 0;
503:
504: switch (cmd) {
505:
506: default:
507: error = EINVAL;
508: break;
509:
510: /*
511: * Check for read packet available.
512: */
513: case FIONREAD:
514: {
515: int n;
516:
517: s = splimp();
518: n = d->bd_slen;
519: if (d->bd_hbuf)
520: n += d->bd_hlen;
521: splx(s);
522:
523: *(int *)addr = n;
524: break;
525: }
526:
527: case SIOCGIFADDR:
528: {
529: struct ifnet *ifp;
530:
531: if (d->bd_bif == 0)
532: error = EINVAL;
533: else {
534: ifp = d->bd_bif->bif_ifp;
535: error = (*ifp->if_ioctl)(ifp, cmd, addr);
536: }
537: break;
538: }
539:
540: /*
541: * Get max filter len.
542: */
543: case BIOCGFLEN:
544: *(u_int *)addr = BPF_MAXINSNS;
545: break;
546: /*
547: * Get buffer len [for read()].
548: */
549: case BIOCGBLEN:
550: *(u_int *)addr = d->bd_bufsize;
551: break;
552:
553: /*
554: * Set ethernet read filter.
555: */
556: case BIOCSETF:
557: error = bpf_setf(d, (struct bpf_program *)addr);
558: break;
559:
560: /*
561: * Flush read packet buffer.
562: */
563: case BIOCFLUSH:
564: s = splimp();
565: reset_d(d);
566: splx(s);
567: break;
568:
569: /*
570: * Put interface into promiscuous mode.
571: */
572: case BIOCPROMISC:
573: if (d->bd_bif == 0) {
574: /*
575: * No interface attached yet.
576: */
577: error = EINVAL;
578: break;
579: }
580: s = splimp();
581: if (d->bd_promisc == 0) {
582: d->bd_promisc = 1;
583: error = ifpromisc(d->bd_bif->bif_ifp, 1);
584: }
585: splx(s);
586: break;
587:
588: /*
589: * Get device parameters.
590: */
591: case BIOCGDLT:
592: if (d->bd_bif == 0)
593: error = EINVAL;
594: else
595: *(u_int *)addr = d->bd_bif->bif_dlt;
596: break;
597:
598: /*
599: * Set interface name.
600: */
601: case BIOCGETIF:
602: if (d->bd_bif == 0)
603: error = EINVAL;
604: else
605: bpf_ifname(d->bd_bif->bif_ifp, (struct ifreq *)addr);
606: break;
607:
608: /*
609: * Set interface.
610: */
611: case BIOCSETIF:
612: error = bpf_setif(d, (struct ifreq *)addr);
613: break;
614:
615: /*
616: * Set read timeout.
617: */
618: case BIOCSRTIMEOUT:
619: {
620: struct timeval *tv = (struct timeval *)addr;
621: u_long msec;
622:
623: /* Compute number of milliseconds. */
624: msec = tv->tv_sec * 1000 + tv->tv_usec / 1000;
625: /* Scale milliseconds to ticks. Assume hard
626: clock has millisecond or greater resolution
627: (i.e. tick >= 1000). For 10ms hardclock,
628: tick/1000 = 10, so rtout<-msec/10. */
629: d->bd_rtout = msec / (tick / 1000);
630: break;
631: }
632:
633: /*
634: * Get read timeout.
635: */
636: case BIOCGRTIMEOUT:
637: {
638: struct timeval *tv = (struct timeval *)addr;
639: u_long msec = d->bd_rtout;
640:
641: msec *= tick / 1000;
642: tv->tv_sec = msec / 1000;
643: tv->tv_usec = msec % 1000;
644: break;
645: }
646:
647: /*
648: * Get packet stats.
649: */
650: case BIOCGSTATS:
651: {
652: struct bpf_stat *bs = (struct bpf_stat *)addr;
653:
654: bs->bs_recv = d->bd_rcount;
655: bs->bs_drop = d->bd_dcount;
656: break;
657: }
658:
659: /*
660: * Set immediate mode.
661: */
662: case BIOCIMMEDIATE:
663: d->bd_immediate = *(u_int *)addr;
664: break;
665: }
666: return (error);
667: }
668:
669: /*
670: * Set d's packet filter program to 'fp'. If 'd' already has a filter,
671: * free it and replace it. Returns EINVAL for bogus requests.
672: */
673: int
674: bpf_setf(d, fp)
675: struct bpf_d *d;
676: struct bpf_program *fp;
677: {
678: struct bpf_insn *fcode, *old;
679: u_int flen, size;
680: int s;
681:
682: old = d->bd_filter;
683: if (fp->bf_insns == 0) {
684: if (fp->bf_len != 0)
685: return (EINVAL);
686: s = splimp();
687: d->bd_filter = 0;
688: reset_d(d);
689: splx(s);
690: if (old != 0)
691: free((caddr_t)old, M_DEVBUF);
692: return (0);
693: }
694: flen = fp->bf_len;
695: if (flen > BPF_MAXINSNS)
696: return (EINVAL);
697:
698: size = flen * sizeof(*fp->bf_insns);
699: fcode = (struct bpf_insn *)malloc(size, M_DEVBUF, M_WAITOK);
700: if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size))
701: return (EINVAL);
702:
703: if (bpf_validate(fcode, (int)flen)) {
704: s = splimp();
705: d->bd_filter = fcode;
706: reset_d(d);
707: splx(s);
708: if (old != 0)
709: free((caddr_t)old, M_DEVBUF);
710:
711: return (0);
712: }
713: free((caddr_t)fcode, M_DEVBUF);
714: return (EINVAL);
715: }
716:
717: /*
718: * Detach 'd' from its current interface (if attached at all) and attach to
719: * the interface named 'name'. Return ioctl error code or 0.
720: */
721: static int
722: bpf_setif(d, ifr)
723: struct bpf_d *d;
724: struct ifreq *ifr;
725: {
726: struct bpf_if *bp;
727: char *cp;
728: int unit, s;
729:
730: /*
731: * Separate string into name part and unit number. Put a null
732: * byte at the end of the name part, and compute the number.
733: * If the a unit number is unspecified, the default is 0,
734: * as initialized above. XXX This should be common code.
735: */
736: unit = 0;
737: cp = ifr->ifr_name;
738: cp[sizeof(ifr->ifr_name) - 1] = '\0';
739: while (*cp++) {
740: if (*cp >= '0' && *cp <= '9') {
741: unit = *cp - '0';
742: *cp++ = '\0';
743: while (*cp)
744: unit = 10 * unit + *cp++ - '0';
745: break;
746: }
747: }
748: /*
749: * Look through attached interfaces for the named one.
750: */
751: for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) {
752: struct ifnet *ifp = bp->bif_ifp;
753:
754: if (ifp == 0 || unit != ifp->if_unit
755: || strcmp(ifp->if_name, ifr->ifr_name) != 0)
756: continue;
757: /*
758: * We found the requested interface. If we're
759: * already attached to it, just flush the buffer.
760: * If it's not up, return an error.
761: */
762: if ((ifp->if_flags & IFF_UP) == 0)
763: return (ENETDOWN);
764: s = splimp();
765: if (bp != d->bd_bif) {
766: if (d->bd_bif)
767: /*
768: * Detach if attached to something else.
769: */
770: bpf_detachd(d);
771:
772: bpf_attachd(d, bp);
773: }
774: reset_d(d);
775: splx(s);
776: return (0);
777: }
778: /* Not found. */
779: return (ENXIO);
780: }
781:
782: /*
783: * Lookup the name of the 'ifp' interface and return it in 'ifr->ifr_name'.
784: * We augment the ifp's base name with its unit number.
785: */
786: static void
787: bpf_ifname(ifp, ifr)
788: struct ifnet *ifp;
789: struct ifreq *ifr;
790: {
791: char *s = ifp->if_name;
792: char *d = ifr->ifr_name;
793:
794: while (*d++ = *s++)
795: ;
796: /* XXX Assume that unit number is less than 10. */
797: *d++ = ifp->if_unit + '0';
798: *d = '\0';
799: }
800:
801: /*
802: * Support for select() system call
803: * Inspired by the code in tty.c for the same purpose.
804: *
805: * bpfselect - returns true iff the specific operation
806: * will not block indefinitely. Otherwise, return
807: * false but make a note that a selwakeup() must be done.
808: */
809: int
810: bpfselect(dev, rw, p)
811: register dev_t dev;
812: int rw;
813: struct proc *p;
814: {
815: register struct bpf_d *d;
816: register int s;
817:
818: if (rw != FREAD)
819: return (0);
820: /*
821: * An imitation of the FIONREAD ioctl code.
822: */
823: d = &bpf_dtab[minor(dev)];
824:
825: s = splimp();
826: if (d->bd_hlen != 0 || (d->bd_immediate && d->bd_slen != 0)) {
827: /*
828: * There is data waiting.
829: */
830: splx(s);
831: return (1);
832: }
833: /*
834: * No data ready. If there's already a select() waiting on this
835: * minor device then this is a collision. This shouldn't happen
836: * because minors really should not be shared, but if a process
837: * forks while one of these is open, it is possible that both
838: * processes could select on the same descriptor.
839: */
840: if (d->bd_selproc && d->bd_selproc->p_wchan == (caddr_t)&selwait)
841: d->bd_selcoll = 1;
842: else
843: d->bd_selproc = p;
844:
845: splx(s);
846: return (0);
847: }
848:
849: /*
850: * bpf_tap - incoming linkage from device drivers
851: */
852: void
853: bpf_tap(arg, pkt, pktlen)
854: caddr_t arg;
855: register u_char *pkt;
856: register u_int pktlen;
857: {
858: struct bpf_if *bp;
859: register struct bpf_d *d;
860: register u_int slen;
861: /*
862: * Note that the ipl does not have to be raised at this point.
863: * The only problem that could arise here is that if two different
864: * interfaces shared any data. This is not the case.
865: */
866: bp = (struct bpf_if *)arg;
867: for (d = bp->bif_dlist; d != 0; d = d->bd_next) {
868: ++d->bd_rcount;
869: slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen);
870: if (slen != 0)
871: catchpacket(d, pkt, pktlen, slen, bcopy);
872: }
873: }
874:
875: /*
876: * Copy data from an mbuf chain into a buffer. This code is derived
877: * from m_copydata in sys/uipc_mbuf.c.
878: */
879: static void
880: bpf_mcopy(src, dst, len)
881: u_char *src;
882: u_char *dst;
883: register int len;
884: {
885: register struct mbuf *m = (struct mbuf *)src;
886: register unsigned count;
887:
888: while (len > 0) {
889: if (m == 0)
890: panic("bpf_mcopy");
891: count = MIN(m->m_len, len);
892: bcopy(mtod(m, caddr_t), (caddr_t)dst, count);
893: m = m->m_next;
894: dst += count;
895: len -= count;
896: }
897: }
898:
899: /*
900: * bpf_mtap - incoming linkage from device drivers, when packet
901: * is in an mbuf chain
902: */
903: void
904: bpf_mtap(arg, m)
905: caddr_t arg;
906: struct mbuf *m;
907: {
908: struct bpf_if *bp = (struct bpf_if *)arg;
909: struct bpf_d *d;
910: u_int pktlen, slen;
911: struct mbuf *m0;
912:
913: pktlen = 0;
914: for (m0 = m; m0 != m; m0 = m0->m_next)
915: pktlen += m0->m_len;
916:
917: for (d = bp->bif_dlist; d != 0; d = d->bd_next) {
918: ++d->bd_rcount;
919: slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0);
920: if (slen != 0)
921: catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy);
922: }
923: }
924:
925: /*
926: * Move the packet data from interface memory (pkt) into the
927: * store buffer. Return 1 if it's time to wakeup a listener (buffer full),
928: * otherwise 0. 'copy' is the routine called to do the actual data
929: * transfer. 'bcopy' is passed in to copy contiguous chunks, while
930: * 'bpf_mcopy' is passed in to copy mbuf chains. In the latter
931: * case, 'pkt' is really an mbuf.
932: */
933: static void
934: catchpacket(d, pkt, pktlen, snaplen, cpfn)
935: register struct bpf_d *d;
936: register u_char *pkt;
937: register u_int pktlen, snaplen;
938: register void (*cpfn)();
939: {
940: register struct bpf_hdr *hp;
941: register int totlen, curlen;
942: register int hdrlen = d->bd_bif->bif_hdrlen;
943: /*
944: * Figure out how many bytes to move. If the packet is
945: * greater or equal to the snapshot length, transfer that
946: * much. Otherwise, transfer the whole packet (unless
947: * we hit the buffer size limit).
948: */
949: totlen = hdrlen + MIN(snaplen, pktlen);
950: if (totlen > d->bd_bufsize)
951: totlen = d->bd_bufsize;
952:
953: /*
954: * Round up the end of the previous packet to the next longword.
955: */
956: curlen = BPF_WORDALIGN(d->bd_slen);
957: if (curlen + totlen > d->bd_bufsize) {
958: /*
959: * This packet will overflow the storage buffer.
960: * Rotate the buffers if we can, then wakeup any
961: * pending reads.
962: */
963: if (d->bd_fbuf == 0) {
964: /*
965: * We haven't completed the previous read yet,
966: * so drop the packet.
967: */
968: ++d->bd_dcount;
969: return;
970: }
971: ROTATE_BUFFERS(d);
972: bpf_wakeup(d);
973: curlen = 0;
974: }
975: else if (d->bd_immediate)
976: /*
977: * Immediate mode is set. A packet arrived so any
978: * reads should be woken up.
979: */
980: bpf_wakeup(d);
981:
982: /*
983: * Append the bpf header.
984: */
985: hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
986: #ifdef sun
987: uniqtime(&hp->bh_tstamp);
988: #else
989: #ifdef hp300
990: microtime(&hp->bh_tstamp);
991: #else
992: hp->bh_tstamp = time;
993: #endif
994: #endif
995: hp->bh_datalen = pktlen;
996: hp->bh_hdrlen = hdrlen;
997: /*
998: * Copy the packet data into the store buffer and update its length.
999: */
1000: (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
1001: d->bd_slen = curlen + totlen;
1002: }
1003:
1004: /*
1005: * Initialize all nonzero fields of a descriptor.
1006: */
1007: static int
1008: bpf_initd(d)
1009: register struct bpf_d *d;
1010: {
1011: d->bd_bufsize = bpf_bufsize;
1012: d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_DEVBUF, M_WAITOK);
1013: if (d->bd_fbuf == 0)
1014: return (ENOBUFS);
1015:
1016: d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_DEVBUF, M_WAITOK);
1017: if (d->bd_sbuf == 0) {
1018: free(d->bd_fbuf, M_DEVBUF);
1019: return (ENOBUFS);
1020: }
1021: d->bd_slen = 0;
1022: d->bd_hlen = 0;
1023: return (0);
1024: }
1025:
1026: /*
1027: * Register 'ifp' with bpf. XXX
1028: * and 'driverp' is a pointer to the 'struct bpf_if *' in the driver's softc.
1029: */
1030: void
1031: bpfattach(driverp, ifp, dlt, hdrlen)
1032: caddr_t *driverp;
1033: struct ifnet *ifp;
1034: u_int dlt, hdrlen;
1035: {
1036: struct bpf_if *bp;
1037: int i;
1038:
1039: bp = (struct bpf_if *)malloc(sizeof(*bp), M_DEVBUF, M_DONTWAIT);
1040: if (bp == 0)
1041: panic("bpfattach");
1042:
1043: bp->bif_dlist = 0;
1044: bp->bif_driverp = (struct bpf_if **)driverp;
1045: bp->bif_ifp = ifp;
1046: bp->bif_dlt = dlt;
1047:
1048: bp->bif_next = bpf_iflist;
1049: bpf_iflist = bp;
1050:
1051: *bp->bif_driverp = 0;
1052:
1053: /*
1054: * Compute the length of the bpf header. This is not necessarily
1055: * equal to SIZEOF_BPF_HDR because we want to insert spacing such
1056: * that the network layer header begins on a longword boundary (for
1057: * performance reasons and to alleviate alignment restrictions).
1058: */
1059: bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
1060:
1061: /*
1062: * Mark all the descriptors free if this hasn't been done.
1063: */
1064: if (!D_ISFREE(&bpf_dtab[0]))
1065: for (i = 0; i < NBPFILTER; ++i)
1066: D_MARKFREE(&bpf_dtab[i]);
1067:
1068: printf("bpf: %s%d attached\n", ifp->if_name, ifp->if_unit);
1069: }
1070:
1071: /* XXX This routine belongs in net/if.c. */
1072: /*
1073: * Set/clear promiscuous mode on interface ifp based on the truth value`
1074: * of pswitch. The calls are reference counted so that only the first
1075: * on request actually has an effect, as does the final off request.
1076: * Results are undefined if the off and on requests are not matched.
1077: */
1078: int
1079: ifpromisc(ifp, pswitch)
1080: struct ifnet *ifp;
1081: int pswitch;
1082: {
1083: struct ifreq ifr;
1084: /*
1085: * If the device is not configured up, we cannot put it in
1086: * promiscuous mode.
1087: */
1088: if ((ifp->if_flags & IFF_UP) == 0)
1089: return (ENETDOWN);
1090:
1091: if (pswitch) {
1092: if (ifp->if_pcount++ != 0)
1093: return (0);
1094: ifp->if_flags |= IFF_PROMISC;
1095: } else {
1096: if (--ifp->if_pcount > 0)
1097: return (0);
1098: ifp->if_flags &= ~IFF_PROMISC;
1099: }
1100: ifr.ifr_flags = ifp->if_flags;
1101: return ((*ifp->if_ioctl)(ifp, SIOCSIFFLAGS, (caddr_t)&ifr));
1102: }
1103:
1104: #endif (NBPFILTER > 0)
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