2011 lines
43 KiB
C
2011 lines
43 KiB
C
/* $NetBSD: bpf.c,v 1.156 2010/03/13 20:38:48 christos Exp $ */
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/*
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* Copyright (c) 1990, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from the Stanford/CMU enet packet filter,
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* (net/enet.c) distributed as part of 4.3BSD, and code contributed
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* to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
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* Berkeley Laboratory.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)bpf.c 8.4 (Berkeley) 1/9/95
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* static char rcsid[] =
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* "Header: bpf.c,v 1.67 96/09/26 22:00:52 leres Exp ";
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: bpf.c,v 1.156 2010/03/13 20:38:48 christos Exp $");
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#if defined(_KERNEL_OPT)
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#include "opt_bpf.h"
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#include "sl.h"
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#include "strip.h"
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#endif
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/mbuf.h>
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#include <sys/buf.h>
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#include <sys/time.h>
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#include <sys/proc.h>
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#include <sys/ioctl.h>
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#include <sys/conf.h>
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#include <sys/vnode.h>
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#include <sys/queue.h>
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#include <sys/stat.h>
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#include <sys/module.h>
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#include <sys/once.h>
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#include <sys/atomic.h>
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#include <sys/file.h>
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#include <sys/filedesc.h>
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#include <sys/tty.h>
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#include <sys/uio.h>
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#include <sys/protosw.h>
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#include <sys/socket.h>
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#include <sys/errno.h>
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#include <sys/kernel.h>
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#include <sys/poll.h>
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#include <sys/sysctl.h>
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#include <sys/kauth.h>
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#include <net/if.h>
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#include <net/slip.h>
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#include <net/bpf.h>
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#include <net/bpfdesc.h>
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#include <net/if_arc.h>
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#include <net/if_ether.h>
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#include <netinet/in.h>
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#include <netinet/if_inarp.h>
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#include <compat/sys/sockio.h>
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#ifndef BPF_BUFSIZE
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/*
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* 4096 is too small for FDDI frames. 8192 is too small for gigabit Ethernet
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* jumbos (circa 9k), ATM, or Intel gig/10gig ethernet jumbos (16k).
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*/
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# define BPF_BUFSIZE 32768
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#endif
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#define PRINET 26 /* interruptible */
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/*
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* The default read buffer size, and limit for BIOCSBLEN, is sysctl'able.
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* XXX the default values should be computed dynamically based
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* on available memory size and available mbuf clusters.
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*/
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int bpf_bufsize = BPF_BUFSIZE;
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int bpf_maxbufsize = BPF_DFLTBUFSIZE; /* XXX set dynamically, see above */
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/*
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* Global BPF statistics returned by net.bpf.stats sysctl.
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*/
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struct bpf_stat bpf_gstats;
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/*
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* Use a mutex to avoid a race condition between gathering the stats/peers
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* and opening/closing the device.
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*/
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static kmutex_t bpf_mtx;
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/*
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* bpf_iflist is the list of interfaces; each corresponds to an ifnet
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* bpf_dtab holds the descriptors, indexed by minor device #
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*/
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struct bpf_if *bpf_iflist;
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LIST_HEAD(, bpf_d) bpf_list;
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static int bpf_allocbufs(struct bpf_d *);
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static void bpf_deliver(struct bpf_if *,
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void *(*cpfn)(void *, const void *, size_t),
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void *, u_int, u_int, struct ifnet *);
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static void bpf_freed(struct bpf_d *);
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static void bpf_ifname(struct ifnet *, struct ifreq *);
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static void *bpf_mcpy(void *, const void *, size_t);
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static int bpf_movein(struct uio *, int, int,
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struct mbuf **, struct sockaddr *);
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static void bpf_attachd(struct bpf_d *, struct bpf_if *);
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static void bpf_detachd(struct bpf_d *);
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static int bpf_setif(struct bpf_d *, struct ifreq *);
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static void bpf_timed_out(void *);
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static inline void
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bpf_wakeup(struct bpf_d *);
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static void catchpacket(struct bpf_d *, u_char *, u_int, u_int,
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void *(*)(void *, const void *, size_t), struct timespec *);
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static void reset_d(struct bpf_d *);
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static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *);
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static int bpf_setdlt(struct bpf_d *, u_int);
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static int bpf_read(struct file *, off_t *, struct uio *, kauth_cred_t,
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int);
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static int bpf_write(struct file *, off_t *, struct uio *, kauth_cred_t,
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int);
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static int bpf_ioctl(struct file *, u_long, void *);
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static int bpf_poll(struct file *, int);
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static int bpf_stat(struct file *, struct stat *);
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static int bpf_close(struct file *);
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static int bpf_kqfilter(struct file *, struct knote *);
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static void bpf_softintr(void *);
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static const struct fileops bpf_fileops = {
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.fo_read = bpf_read,
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.fo_write = bpf_write,
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.fo_ioctl = bpf_ioctl,
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.fo_fcntl = fnullop_fcntl,
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.fo_poll = bpf_poll,
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.fo_stat = bpf_stat,
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.fo_close = bpf_close,
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.fo_kqfilter = bpf_kqfilter,
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.fo_restart = fnullop_restart,
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};
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dev_type_open(bpfopen);
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const struct cdevsw bpf_cdevsw = {
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bpfopen, noclose, noread, nowrite, noioctl,
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nostop, notty, nopoll, nommap, nokqfilter, D_OTHER
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};
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static int
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bpf_movein(struct uio *uio, int linktype, int mtu, struct mbuf **mp,
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struct sockaddr *sockp)
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{
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struct mbuf *m;
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int error;
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int len;
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int hlen;
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int align;
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/*
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* Build a sockaddr based on the data link layer type.
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* We do this at this level because the ethernet header
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* is copied directly into the data field of the sockaddr.
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* In the case of SLIP, there is no header and the packet
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* is forwarded as is.
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* Also, we are careful to leave room at the front of the mbuf
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* for the link level header.
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*/
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switch (linktype) {
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case DLT_SLIP:
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sockp->sa_family = AF_INET;
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hlen = 0;
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align = 0;
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break;
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case DLT_PPP:
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sockp->sa_family = AF_UNSPEC;
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hlen = 0;
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align = 0;
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break;
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case DLT_EN10MB:
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sockp->sa_family = AF_UNSPEC;
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/* XXX Would MAXLINKHDR be better? */
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/* 6(dst)+6(src)+2(type) */
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hlen = sizeof(struct ether_header);
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align = 2;
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break;
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case DLT_ARCNET:
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sockp->sa_family = AF_UNSPEC;
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hlen = ARC_HDRLEN;
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align = 5;
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break;
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case DLT_FDDI:
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sockp->sa_family = AF_LINK;
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/* XXX 4(FORMAC)+6(dst)+6(src) */
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hlen = 16;
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align = 0;
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break;
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case DLT_ECONET:
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sockp->sa_family = AF_UNSPEC;
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hlen = 6;
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align = 2;
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break;
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case DLT_NULL:
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sockp->sa_family = AF_UNSPEC;
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hlen = 0;
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align = 0;
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break;
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default:
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return (EIO);
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}
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len = uio->uio_resid;
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/*
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* If there aren't enough bytes for a link level header or the
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* packet length exceeds the interface mtu, return an error.
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*/
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if (len < hlen || len - hlen > mtu)
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return (EMSGSIZE);
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/*
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* XXX Avoid complicated buffer chaining ---
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* bail if it won't fit in a single mbuf.
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* (Take into account possible alignment bytes)
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*/
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if ((unsigned)len > MCLBYTES - align)
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return (EIO);
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m = m_gethdr(M_WAIT, MT_DATA);
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m->m_pkthdr.rcvif = 0;
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m->m_pkthdr.len = len - hlen;
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if (len > MHLEN - align) {
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m_clget(m, M_WAIT);
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if ((m->m_flags & M_EXT) == 0) {
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error = ENOBUFS;
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goto bad;
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}
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}
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/* Insure the data is properly aligned */
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if (align > 0) {
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m->m_data += align;
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m->m_len -= align;
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}
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error = uiomove(mtod(m, void *), len, uio);
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if (error)
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goto bad;
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if (hlen != 0) {
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memcpy(sockp->sa_data, mtod(m, void *), hlen);
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m->m_data += hlen; /* XXX */
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len -= hlen;
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}
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m->m_len = len;
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*mp = m;
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return (0);
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bad:
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m_freem(m);
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return (error);
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}
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/*
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* Attach file to the bpf interface, i.e. make d listen on bp.
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* Must be called at splnet.
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*/
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static void
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bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
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{
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/*
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* Point d at bp, and add d to the interface's list of listeners.
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* Finally, point the driver's bpf cookie at the interface so
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* it will divert packets to bpf.
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*/
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d->bd_bif = bp;
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d->bd_next = bp->bif_dlist;
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bp->bif_dlist = d;
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*bp->bif_driverp = bp;
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}
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/*
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* Detach a file from its interface.
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*/
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static void
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bpf_detachd(struct bpf_d *d)
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{
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struct bpf_d **p;
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struct bpf_if *bp;
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bp = d->bd_bif;
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/*
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* Check if this descriptor had requested promiscuous mode.
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* If so, turn it off.
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*/
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if (d->bd_promisc) {
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int error;
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d->bd_promisc = 0;
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/*
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* Take device out of promiscuous mode. Since we were
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* able to enter promiscuous mode, we should be able
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* to turn it off. But we can get an error if
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* the interface was configured down, so only panic
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* if we don't get an unexpected error.
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*/
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error = ifpromisc(bp->bif_ifp, 0);
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if (error && error != EINVAL)
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panic("%s: ifpromisc failed: %d", __func__, error);
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}
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/* Remove d from the interface's descriptor list. */
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p = &bp->bif_dlist;
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while (*p != d) {
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p = &(*p)->bd_next;
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if (*p == 0)
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panic("%s: descriptor not in list", __func__);
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}
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*p = (*p)->bd_next;
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if (bp->bif_dlist == 0)
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/*
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* Let the driver know that there are no more listeners.
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*/
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*d->bd_bif->bif_driverp = 0;
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d->bd_bif = 0;
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}
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static int
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doinit(void)
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{
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mutex_init(&bpf_mtx, MUTEX_DEFAULT, IPL_NONE);
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LIST_INIT(&bpf_list);
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bpf_gstats.bs_recv = 0;
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bpf_gstats.bs_drop = 0;
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bpf_gstats.bs_capt = 0;
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return 0;
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}
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/*
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* bpfilterattach() is called at boot time.
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*/
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/* ARGSUSED */
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void
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bpfilterattach(int n)
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{
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static ONCE_DECL(control);
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RUN_ONCE(&control, doinit);
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}
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/*
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* Open ethernet device. Clones.
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*/
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/* ARGSUSED */
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int
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bpfopen(dev_t dev, int flag, int mode, struct lwp *l)
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{
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struct bpf_d *d;
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struct file *fp;
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int error, fd;
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/* falloc() will use the descriptor for us. */
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if ((error = fd_allocfile(&fp, &fd)) != 0)
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return error;
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d = malloc(sizeof(*d), M_DEVBUF, M_WAITOK|M_ZERO);
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d->bd_bufsize = bpf_bufsize;
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d->bd_seesent = 1;
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d->bd_feedback = 0;
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d->bd_pid = l->l_proc->p_pid;
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getnanotime(&d->bd_btime);
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d->bd_atime = d->bd_mtime = d->bd_btime;
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callout_init(&d->bd_callout, 0);
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selinit(&d->bd_sel);
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d->bd_sih = softint_establish(SOFTINT_CLOCK, bpf_softintr, d);
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mutex_enter(&bpf_mtx);
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LIST_INSERT_HEAD(&bpf_list, d, bd_list);
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mutex_exit(&bpf_mtx);
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return fd_clone(fp, fd, flag, &bpf_fileops, d);
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}
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/*
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* Close the descriptor by detaching it from its interface,
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* deallocating its buffers, and marking it free.
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*/
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/* ARGSUSED */
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static int
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bpf_close(struct file *fp)
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{
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struct bpf_d *d = fp->f_data;
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int s;
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KERNEL_LOCK(1, NULL);
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/*
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* Refresh the PID associated with this bpf file.
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*/
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d->bd_pid = curproc->p_pid;
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s = splnet();
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if (d->bd_state == BPF_WAITING)
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callout_stop(&d->bd_callout);
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d->bd_state = BPF_IDLE;
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if (d->bd_bif)
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bpf_detachd(d);
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splx(s);
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bpf_freed(d);
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mutex_enter(&bpf_mtx);
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LIST_REMOVE(d, bd_list);
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mutex_exit(&bpf_mtx);
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callout_destroy(&d->bd_callout);
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seldestroy(&d->bd_sel);
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softint_disestablish(d->bd_sih);
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free(d, M_DEVBUF);
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fp->f_data = NULL;
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KERNEL_UNLOCK_ONE(NULL);
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return (0);
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}
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/*
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* Rotate the packet buffers in descriptor d. Move the store buffer
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* into the hold slot, and the free buffer into the store slot.
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* Zero the length of the new store buffer.
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*/
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#define ROTATE_BUFFERS(d) \
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(d)->bd_hbuf = (d)->bd_sbuf; \
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(d)->bd_hlen = (d)->bd_slen; \
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(d)->bd_sbuf = (d)->bd_fbuf; \
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(d)->bd_slen = 0; \
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(d)->bd_fbuf = 0;
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/*
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* bpfread - read next chunk of packets from buffers
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*/
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static int
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bpf_read(struct file *fp, off_t *offp, struct uio *uio,
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kauth_cred_t cred, int flags)
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{
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struct bpf_d *d = fp->f_data;
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int timed_out;
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int error;
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int s;
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getnanotime(&d->bd_atime);
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/*
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* Restrict application to use a buffer the same size as
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* the kernel buffers.
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*/
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if (uio->uio_resid != d->bd_bufsize)
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return (EINVAL);
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KERNEL_LOCK(1, NULL);
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s = splnet();
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if (d->bd_state == BPF_WAITING)
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callout_stop(&d->bd_callout);
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timed_out = (d->bd_state == BPF_TIMED_OUT);
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d->bd_state = BPF_IDLE;
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/*
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* If the hold buffer is empty, then do a timed sleep, which
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* ends when the timeout expires or when enough packets
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* have arrived to fill the store buffer.
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*/
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while (d->bd_hbuf == 0) {
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if (fp->f_flag & FNONBLOCK) {
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if (d->bd_slen == 0) {
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splx(s);
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KERNEL_UNLOCK_ONE(NULL);
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return (EWOULDBLOCK);
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}
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ROTATE_BUFFERS(d);
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break;
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}
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if ((d->bd_immediate || timed_out) && d->bd_slen != 0) {
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|
/*
|
|
* A packet(s) either arrived since the previous
|
|
* read or arrived while we were asleep.
|
|
* Rotate the buffers and return what's here.
|
|
*/
|
|
ROTATE_BUFFERS(d);
|
|
break;
|
|
}
|
|
error = tsleep(d, PRINET|PCATCH, "bpf",
|
|
d->bd_rtout);
|
|
if (error == EINTR || error == ERESTART) {
|
|
splx(s);
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
return (error);
|
|
}
|
|
if (error == EWOULDBLOCK) {
|
|
/*
|
|
* On a timeout, return what's in the buffer,
|
|
* which may be nothing. If there is something
|
|
* in the store buffer, we can rotate the buffers.
|
|
*/
|
|
if (d->bd_hbuf)
|
|
/*
|
|
* We filled up the buffer in between
|
|
* getting the timeout and arriving
|
|
* here, so we don't need to rotate.
|
|
*/
|
|
break;
|
|
|
|
if (d->bd_slen == 0) {
|
|
splx(s);
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
return (0);
|
|
}
|
|
ROTATE_BUFFERS(d);
|
|
break;
|
|
}
|
|
if (error != 0)
|
|
goto done;
|
|
}
|
|
/*
|
|
* At this point, we know we have something in the hold slot.
|
|
*/
|
|
splx(s);
|
|
|
|
/*
|
|
* Move data from hold buffer into user space.
|
|
* We know the entire buffer is transferred since
|
|
* we checked above that the read buffer is bpf_bufsize bytes.
|
|
*/
|
|
error = uiomove(d->bd_hbuf, d->bd_hlen, uio);
|
|
|
|
s = splnet();
|
|
d->bd_fbuf = d->bd_hbuf;
|
|
d->bd_hbuf = 0;
|
|
d->bd_hlen = 0;
|
|
done:
|
|
splx(s);
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
return (error);
|
|
}
|
|
|
|
|
|
/*
|
|
* If there are processes sleeping on this descriptor, wake them up.
|
|
*/
|
|
static inline void
|
|
bpf_wakeup(struct bpf_d *d)
|
|
{
|
|
wakeup(d);
|
|
if (d->bd_async)
|
|
softint_schedule(d->bd_sih);
|
|
selnotify(&d->bd_sel, 0, 0);
|
|
}
|
|
|
|
static void
|
|
bpf_softintr(void *cookie)
|
|
{
|
|
struct bpf_d *d;
|
|
|
|
d = cookie;
|
|
if (d->bd_async)
|
|
fownsignal(d->bd_pgid, SIGIO, 0, 0, NULL);
|
|
}
|
|
|
|
static void
|
|
bpf_timed_out(void *arg)
|
|
{
|
|
struct bpf_d *d = arg;
|
|
int s;
|
|
|
|
s = splnet();
|
|
if (d->bd_state == BPF_WAITING) {
|
|
d->bd_state = BPF_TIMED_OUT;
|
|
if (d->bd_slen != 0)
|
|
bpf_wakeup(d);
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
|
|
static int
|
|
bpf_write(struct file *fp, off_t *offp, struct uio *uio,
|
|
kauth_cred_t cred, int flags)
|
|
{
|
|
struct bpf_d *d = fp->f_data;
|
|
struct ifnet *ifp;
|
|
struct mbuf *m, *mc;
|
|
int error, s;
|
|
static struct sockaddr_storage dst;
|
|
|
|
m = NULL; /* XXX gcc */
|
|
|
|
KERNEL_LOCK(1, NULL);
|
|
|
|
if (d->bd_bif == 0) {
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
return (ENXIO);
|
|
}
|
|
getnanotime(&d->bd_mtime);
|
|
|
|
ifp = d->bd_bif->bif_ifp;
|
|
|
|
if (uio->uio_resid == 0) {
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
return (0);
|
|
}
|
|
|
|
error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp->if_mtu, &m,
|
|
(struct sockaddr *) &dst);
|
|
if (error) {
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
return (error);
|
|
}
|
|
|
|
if (m->m_pkthdr.len > ifp->if_mtu) {
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
m_freem(m);
|
|
return (EMSGSIZE);
|
|
}
|
|
|
|
if (d->bd_hdrcmplt)
|
|
dst.ss_family = pseudo_AF_HDRCMPLT;
|
|
|
|
if (d->bd_feedback) {
|
|
mc = m_dup(m, 0, M_COPYALL, M_NOWAIT);
|
|
if (mc != NULL)
|
|
mc->m_pkthdr.rcvif = ifp;
|
|
/* Set M_PROMISC for outgoing packets to be discarded. */
|
|
if (1 /*d->bd_direction == BPF_D_INOUT*/)
|
|
m->m_flags |= M_PROMISC;
|
|
} else
|
|
mc = NULL;
|
|
|
|
s = splsoftnet();
|
|
error = (*ifp->if_output)(ifp, m, (struct sockaddr *) &dst, NULL);
|
|
|
|
if (mc != NULL) {
|
|
if (error == 0)
|
|
(*ifp->if_input)(ifp, mc);
|
|
} else
|
|
m_freem(mc);
|
|
splx(s);
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
/*
|
|
* The driver frees the mbuf.
|
|
*/
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Reset a descriptor by flushing its packet buffer and clearing the
|
|
* receive and drop counts. Should be called at splnet.
|
|
*/
|
|
static void
|
|
reset_d(struct bpf_d *d)
|
|
{
|
|
if (d->bd_hbuf) {
|
|
/* Free the hold buffer. */
|
|
d->bd_fbuf = d->bd_hbuf;
|
|
d->bd_hbuf = 0;
|
|
}
|
|
d->bd_slen = 0;
|
|
d->bd_hlen = 0;
|
|
d->bd_rcount = 0;
|
|
d->bd_dcount = 0;
|
|
d->bd_ccount = 0;
|
|
}
|
|
|
|
/*
|
|
* FIONREAD Check for read packet available.
|
|
* BIOCGBLEN Get buffer len [for read()].
|
|
* BIOCSETF Set ethernet read filter.
|
|
* BIOCFLUSH Flush read packet buffer.
|
|
* BIOCPROMISC Put interface into promiscuous mode.
|
|
* BIOCGDLT Get link layer type.
|
|
* BIOCGETIF Get interface name.
|
|
* BIOCSETIF Set interface.
|
|
* BIOCSRTIMEOUT Set read timeout.
|
|
* BIOCGRTIMEOUT Get read timeout.
|
|
* BIOCGSTATS Get packet stats.
|
|
* BIOCIMMEDIATE Set immediate mode.
|
|
* BIOCVERSION Get filter language version.
|
|
* BIOCGHDRCMPLT Get "header already complete" flag.
|
|
* BIOCSHDRCMPLT Set "header already complete" flag.
|
|
* BIOCSFEEDBACK Set packet feedback mode.
|
|
* BIOCGFEEDBACK Get packet feedback mode.
|
|
* BIOCGSEESENT Get "see sent packets" mode.
|
|
* BIOCSSEESENT Set "see sent packets" mode.
|
|
*/
|
|
/* ARGSUSED */
|
|
static int
|
|
bpf_ioctl(struct file *fp, u_long cmd, void *addr)
|
|
{
|
|
struct bpf_d *d = fp->f_data;
|
|
int s, error = 0;
|
|
|
|
/*
|
|
* Refresh the PID associated with this bpf file.
|
|
*/
|
|
KERNEL_LOCK(1, NULL);
|
|
d->bd_pid = curproc->p_pid;
|
|
|
|
s = splnet();
|
|
if (d->bd_state == BPF_WAITING)
|
|
callout_stop(&d->bd_callout);
|
|
d->bd_state = BPF_IDLE;
|
|
splx(s);
|
|
|
|
switch (cmd) {
|
|
|
|
default:
|
|
error = EINVAL;
|
|
break;
|
|
|
|
/*
|
|
* Check for read packet available.
|
|
*/
|
|
case FIONREAD:
|
|
{
|
|
int n;
|
|
|
|
s = splnet();
|
|
n = d->bd_slen;
|
|
if (d->bd_hbuf)
|
|
n += d->bd_hlen;
|
|
splx(s);
|
|
|
|
*(int *)addr = n;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Get buffer len [for read()].
|
|
*/
|
|
case BIOCGBLEN:
|
|
*(u_int *)addr = d->bd_bufsize;
|
|
break;
|
|
|
|
/*
|
|
* Set buffer length.
|
|
*/
|
|
case BIOCSBLEN:
|
|
if (d->bd_bif != 0)
|
|
error = EINVAL;
|
|
else {
|
|
u_int size = *(u_int *)addr;
|
|
|
|
if (size > bpf_maxbufsize)
|
|
*(u_int *)addr = size = bpf_maxbufsize;
|
|
else if (size < BPF_MINBUFSIZE)
|
|
*(u_int *)addr = size = BPF_MINBUFSIZE;
|
|
d->bd_bufsize = size;
|
|
}
|
|
break;
|
|
|
|
/*
|
|
* Set link layer read filter.
|
|
*/
|
|
case BIOCSETF:
|
|
error = bpf_setf(d, addr);
|
|
break;
|
|
|
|
/*
|
|
* Flush read packet buffer.
|
|
*/
|
|
case BIOCFLUSH:
|
|
s = splnet();
|
|
reset_d(d);
|
|
splx(s);
|
|
break;
|
|
|
|
/*
|
|
* Put interface into promiscuous mode.
|
|
*/
|
|
case BIOCPROMISC:
|
|
if (d->bd_bif == 0) {
|
|
/*
|
|
* No interface attached yet.
|
|
*/
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
s = splnet();
|
|
if (d->bd_promisc == 0) {
|
|
error = ifpromisc(d->bd_bif->bif_ifp, 1);
|
|
if (error == 0)
|
|
d->bd_promisc = 1;
|
|
}
|
|
splx(s);
|
|
break;
|
|
|
|
/*
|
|
* Get device parameters.
|
|
*/
|
|
case BIOCGDLT:
|
|
if (d->bd_bif == 0)
|
|
error = EINVAL;
|
|
else
|
|
*(u_int *)addr = d->bd_bif->bif_dlt;
|
|
break;
|
|
|
|
/*
|
|
* Get a list of supported device parameters.
|
|
*/
|
|
case BIOCGDLTLIST:
|
|
if (d->bd_bif == 0)
|
|
error = EINVAL;
|
|
else
|
|
error = bpf_getdltlist(d, addr);
|
|
break;
|
|
|
|
/*
|
|
* Set device parameters.
|
|
*/
|
|
case BIOCSDLT:
|
|
if (d->bd_bif == 0)
|
|
error = EINVAL;
|
|
else
|
|
error = bpf_setdlt(d, *(u_int *)addr);
|
|
break;
|
|
|
|
/*
|
|
* Set interface name.
|
|
*/
|
|
#ifdef OBIOCGETIF
|
|
case OBIOCGETIF:
|
|
#endif
|
|
case BIOCGETIF:
|
|
if (d->bd_bif == 0)
|
|
error = EINVAL;
|
|
else
|
|
bpf_ifname(d->bd_bif->bif_ifp, addr);
|
|
break;
|
|
|
|
/*
|
|
* Set interface.
|
|
*/
|
|
#ifdef OBIOCSETIF
|
|
case OBIOCSETIF:
|
|
#endif
|
|
case BIOCSETIF:
|
|
error = bpf_setif(d, addr);
|
|
break;
|
|
|
|
/*
|
|
* Set read timeout.
|
|
*/
|
|
case BIOCSRTIMEOUT:
|
|
{
|
|
struct timeval *tv = addr;
|
|
|
|
/* Compute number of ticks. */
|
|
d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick;
|
|
if ((d->bd_rtout == 0) && (tv->tv_usec != 0))
|
|
d->bd_rtout = 1;
|
|
break;
|
|
}
|
|
|
|
#ifdef BIOCGORTIMEOUT
|
|
/*
|
|
* Get read timeout.
|
|
*/
|
|
case BIOCGORTIMEOUT:
|
|
{
|
|
struct timeval50 *tv = addr;
|
|
|
|
tv->tv_sec = d->bd_rtout / hz;
|
|
tv->tv_usec = (d->bd_rtout % hz) * tick;
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
#ifdef BIOCSORTIMEOUT
|
|
/*
|
|
* Set read timeout.
|
|
*/
|
|
case BIOCSORTIMEOUT:
|
|
{
|
|
struct timeval50 *tv = addr;
|
|
|
|
/* Compute number of ticks. */
|
|
d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick;
|
|
if ((d->bd_rtout == 0) && (tv->tv_usec != 0))
|
|
d->bd_rtout = 1;
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Get read timeout.
|
|
*/
|
|
case BIOCGRTIMEOUT:
|
|
{
|
|
struct timeval *tv = addr;
|
|
|
|
tv->tv_sec = d->bd_rtout / hz;
|
|
tv->tv_usec = (d->bd_rtout % hz) * tick;
|
|
break;
|
|
}
|
|
/*
|
|
* Get packet stats.
|
|
*/
|
|
case BIOCGSTATS:
|
|
{
|
|
struct bpf_stat *bs = addr;
|
|
|
|
bs->bs_recv = d->bd_rcount;
|
|
bs->bs_drop = d->bd_dcount;
|
|
bs->bs_capt = d->bd_ccount;
|
|
break;
|
|
}
|
|
|
|
case BIOCGSTATSOLD:
|
|
{
|
|
struct bpf_stat_old *bs = addr;
|
|
|
|
bs->bs_recv = d->bd_rcount;
|
|
bs->bs_drop = d->bd_dcount;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Set immediate mode.
|
|
*/
|
|
case BIOCIMMEDIATE:
|
|
d->bd_immediate = *(u_int *)addr;
|
|
break;
|
|
|
|
case BIOCVERSION:
|
|
{
|
|
struct bpf_version *bv = addr;
|
|
|
|
bv->bv_major = BPF_MAJOR_VERSION;
|
|
bv->bv_minor = BPF_MINOR_VERSION;
|
|
break;
|
|
}
|
|
|
|
case BIOCGHDRCMPLT: /* get "header already complete" flag */
|
|
*(u_int *)addr = d->bd_hdrcmplt;
|
|
break;
|
|
|
|
case BIOCSHDRCMPLT: /* set "header already complete" flag */
|
|
d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
|
|
break;
|
|
|
|
/*
|
|
* Get "see sent packets" flag
|
|
*/
|
|
case BIOCGSEESENT:
|
|
*(u_int *)addr = d->bd_seesent;
|
|
break;
|
|
|
|
/*
|
|
* Set "see sent" packets flag
|
|
*/
|
|
case BIOCSSEESENT:
|
|
d->bd_seesent = *(u_int *)addr;
|
|
break;
|
|
|
|
/*
|
|
* Set "feed packets from bpf back to input" mode
|
|
*/
|
|
case BIOCSFEEDBACK:
|
|
d->bd_feedback = *(u_int *)addr;
|
|
break;
|
|
|
|
/*
|
|
* Get "feed packets from bpf back to input" mode
|
|
*/
|
|
case BIOCGFEEDBACK:
|
|
*(u_int *)addr = d->bd_feedback;
|
|
break;
|
|
|
|
case FIONBIO: /* Non-blocking I/O */
|
|
/*
|
|
* No need to do anything special as we use IO_NDELAY in
|
|
* bpfread() as an indication of whether or not to block
|
|
* the read.
|
|
*/
|
|
break;
|
|
|
|
case FIOASYNC: /* Send signal on receive packets */
|
|
d->bd_async = *(int *)addr;
|
|
break;
|
|
|
|
case TIOCSPGRP: /* Process or group to send signals to */
|
|
case FIOSETOWN:
|
|
error = fsetown(&d->bd_pgid, cmd, addr);
|
|
break;
|
|
|
|
case TIOCGPGRP:
|
|
case FIOGETOWN:
|
|
error = fgetown(d->bd_pgid, cmd, addr);
|
|
break;
|
|
}
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Set d's packet filter program to fp. If this file already has a filter,
|
|
* free it and replace it. Returns EINVAL for bogus requests.
|
|
*/
|
|
int
|
|
bpf_setf(struct bpf_d *d, struct bpf_program *fp)
|
|
{
|
|
struct bpf_insn *fcode, *old;
|
|
u_int flen, size;
|
|
int s;
|
|
|
|
old = d->bd_filter;
|
|
if (fp->bf_insns == 0) {
|
|
if (fp->bf_len != 0)
|
|
return (EINVAL);
|
|
s = splnet();
|
|
d->bd_filter = 0;
|
|
reset_d(d);
|
|
splx(s);
|
|
if (old != 0)
|
|
free(old, M_DEVBUF);
|
|
return (0);
|
|
}
|
|
flen = fp->bf_len;
|
|
if (flen > BPF_MAXINSNS)
|
|
return (EINVAL);
|
|
|
|
size = flen * sizeof(*fp->bf_insns);
|
|
fcode = malloc(size, M_DEVBUF, M_WAITOK);
|
|
if (copyin(fp->bf_insns, fcode, size) == 0 &&
|
|
bpf_validate(fcode, (int)flen)) {
|
|
s = splnet();
|
|
d->bd_filter = fcode;
|
|
reset_d(d);
|
|
splx(s);
|
|
if (old != 0)
|
|
free(old, M_DEVBUF);
|
|
|
|
return (0);
|
|
}
|
|
free(fcode, M_DEVBUF);
|
|
return (EINVAL);
|
|
}
|
|
|
|
/*
|
|
* Detach a file from its current interface (if attached at all) and attach
|
|
* to the interface indicated by the name stored in ifr.
|
|
* Return an errno or 0.
|
|
*/
|
|
static int
|
|
bpf_setif(struct bpf_d *d, struct ifreq *ifr)
|
|
{
|
|
struct bpf_if *bp;
|
|
char *cp;
|
|
int unit_seen, i, s, error;
|
|
|
|
/*
|
|
* Make sure the provided name has a unit number, and default
|
|
* it to '0' if not specified.
|
|
* XXX This is ugly ... do this differently?
|
|
*/
|
|
unit_seen = 0;
|
|
cp = ifr->ifr_name;
|
|
cp[sizeof(ifr->ifr_name) - 1] = '\0'; /* sanity */
|
|
while (*cp++)
|
|
if (*cp >= '0' && *cp <= '9')
|
|
unit_seen = 1;
|
|
if (!unit_seen) {
|
|
/* Make sure to leave room for the '\0'. */
|
|
for (i = 0; i < (IFNAMSIZ - 1); ++i) {
|
|
if ((ifr->ifr_name[i] >= 'a' &&
|
|
ifr->ifr_name[i] <= 'z') ||
|
|
(ifr->ifr_name[i] >= 'A' &&
|
|
ifr->ifr_name[i] <= 'Z'))
|
|
continue;
|
|
ifr->ifr_name[i] = '0';
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Look through attached interfaces for the named one.
|
|
*/
|
|
for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) {
|
|
struct ifnet *ifp = bp->bif_ifp;
|
|
|
|
if (ifp == 0 ||
|
|
strcmp(ifp->if_xname, ifr->ifr_name) != 0)
|
|
continue;
|
|
/* skip additional entry */
|
|
if (bp->bif_driverp != &ifp->if_bpf)
|
|
continue;
|
|
/*
|
|
* We found the requested interface.
|
|
* Allocate the packet buffers if we need to.
|
|
* If we're already attached to requested interface,
|
|
* just flush the buffer.
|
|
*/
|
|
if (d->bd_sbuf == 0) {
|
|
error = bpf_allocbufs(d);
|
|
if (error != 0)
|
|
return (error);
|
|
}
|
|
s = splnet();
|
|
if (bp != d->bd_bif) {
|
|
if (d->bd_bif)
|
|
/*
|
|
* Detach if attached to something else.
|
|
*/
|
|
bpf_detachd(d);
|
|
|
|
bpf_attachd(d, bp);
|
|
}
|
|
reset_d(d);
|
|
splx(s);
|
|
return (0);
|
|
}
|
|
/* Not found. */
|
|
return (ENXIO);
|
|
}
|
|
|
|
/*
|
|
* Copy the interface name to the ifreq.
|
|
*/
|
|
static void
|
|
bpf_ifname(struct ifnet *ifp, struct ifreq *ifr)
|
|
{
|
|
memcpy(ifr->ifr_name, ifp->if_xname, IFNAMSIZ);
|
|
}
|
|
|
|
static int
|
|
bpf_stat(struct file *fp, struct stat *st)
|
|
{
|
|
struct bpf_d *d = fp->f_data;
|
|
|
|
(void)memset(st, 0, sizeof(*st));
|
|
KERNEL_LOCK(1, NULL);
|
|
st->st_dev = makedev(cdevsw_lookup_major(&bpf_cdevsw), d->bd_pid);
|
|
st->st_atimespec = d->bd_atime;
|
|
st->st_mtimespec = d->bd_mtime;
|
|
st->st_ctimespec = st->st_birthtimespec = d->bd_btime;
|
|
st->st_uid = kauth_cred_geteuid(fp->f_cred);
|
|
st->st_gid = kauth_cred_getegid(fp->f_cred);
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Support for poll() system call
|
|
*
|
|
* Return true iff the specific operation will not block indefinitely - with
|
|
* the assumption that it is safe to positively acknowledge a request for the
|
|
* ability to write to the BPF device.
|
|
* Otherwise, return false but make a note that a selnotify() must be done.
|
|
*/
|
|
static int
|
|
bpf_poll(struct file *fp, int events)
|
|
{
|
|
struct bpf_d *d = fp->f_data;
|
|
int s = splnet();
|
|
int revents;
|
|
|
|
/*
|
|
* Refresh the PID associated with this bpf file.
|
|
*/
|
|
KERNEL_LOCK(1, NULL);
|
|
d->bd_pid = curproc->p_pid;
|
|
|
|
revents = events & (POLLOUT | POLLWRNORM);
|
|
if (events & (POLLIN | POLLRDNORM)) {
|
|
/*
|
|
* An imitation of the FIONREAD ioctl code.
|
|
*/
|
|
if (d->bd_hlen != 0 ||
|
|
((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
|
|
d->bd_slen != 0)) {
|
|
revents |= events & (POLLIN | POLLRDNORM);
|
|
} else {
|
|
selrecord(curlwp, &d->bd_sel);
|
|
/* Start the read timeout if necessary */
|
|
if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
|
|
callout_reset(&d->bd_callout, d->bd_rtout,
|
|
bpf_timed_out, d);
|
|
d->bd_state = BPF_WAITING;
|
|
}
|
|
}
|
|
}
|
|
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
splx(s);
|
|
return (revents);
|
|
}
|
|
|
|
static void
|
|
filt_bpfrdetach(struct knote *kn)
|
|
{
|
|
struct bpf_d *d = kn->kn_hook;
|
|
int s;
|
|
|
|
KERNEL_LOCK(1, NULL);
|
|
s = splnet();
|
|
SLIST_REMOVE(&d->bd_sel.sel_klist, kn, knote, kn_selnext);
|
|
splx(s);
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
}
|
|
|
|
static int
|
|
filt_bpfread(struct knote *kn, long hint)
|
|
{
|
|
struct bpf_d *d = kn->kn_hook;
|
|
int rv;
|
|
|
|
KERNEL_LOCK(1, NULL);
|
|
kn->kn_data = d->bd_hlen;
|
|
if (d->bd_immediate)
|
|
kn->kn_data += d->bd_slen;
|
|
rv = (kn->kn_data > 0);
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
return rv;
|
|
}
|
|
|
|
static const struct filterops bpfread_filtops =
|
|
{ 1, NULL, filt_bpfrdetach, filt_bpfread };
|
|
|
|
static int
|
|
bpf_kqfilter(struct file *fp, struct knote *kn)
|
|
{
|
|
struct bpf_d *d = fp->f_data;
|
|
struct klist *klist;
|
|
int s;
|
|
|
|
KERNEL_LOCK(1, NULL);
|
|
|
|
switch (kn->kn_filter) {
|
|
case EVFILT_READ:
|
|
klist = &d->bd_sel.sel_klist;
|
|
kn->kn_fop = &bpfread_filtops;
|
|
break;
|
|
|
|
default:
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
return (EINVAL);
|
|
}
|
|
|
|
kn->kn_hook = d;
|
|
|
|
s = splnet();
|
|
SLIST_INSERT_HEAD(klist, kn, kn_selnext);
|
|
splx(s);
|
|
KERNEL_UNLOCK_ONE(NULL);
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Incoming linkage from device drivers. Process the packet pkt, of length
|
|
* pktlen, which is stored in a contiguous buffer. The packet is parsed
|
|
* by each process' filter, and if accepted, stashed into the corresponding
|
|
* buffer.
|
|
*/
|
|
static void
|
|
bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen)
|
|
{
|
|
struct bpf_d *d;
|
|
u_int slen;
|
|
struct timespec ts;
|
|
int gottime=0;
|
|
|
|
/*
|
|
* Note that the ipl does not have to be raised at this point.
|
|
* The only problem that could arise here is that if two different
|
|
* interfaces shared any data. This is not the case.
|
|
*/
|
|
for (d = bp->bif_dlist; d != 0; d = d->bd_next) {
|
|
++d->bd_rcount;
|
|
++bpf_gstats.bs_recv;
|
|
slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen);
|
|
if (slen != 0) {
|
|
if (!gottime) {
|
|
nanotime(&ts);
|
|
gottime = 1;
|
|
}
|
|
catchpacket(d, pkt, pktlen, slen, memcpy, &ts);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Copy data from an mbuf chain into a buffer. This code is derived
|
|
* from m_copydata in sys/uipc_mbuf.c.
|
|
*/
|
|
static void *
|
|
bpf_mcpy(void *dst_arg, const void *src_arg, size_t len)
|
|
{
|
|
const struct mbuf *m;
|
|
u_int count;
|
|
u_char *dst;
|
|
|
|
m = src_arg;
|
|
dst = dst_arg;
|
|
while (len > 0) {
|
|
if (m == NULL)
|
|
panic("bpf_mcpy");
|
|
count = min(m->m_len, len);
|
|
memcpy(dst, mtod(m, const void *), count);
|
|
m = m->m_next;
|
|
dst += count;
|
|
len -= count;
|
|
}
|
|
return dst_arg;
|
|
}
|
|
|
|
/*
|
|
* Dispatch a packet to all the listeners on interface bp.
|
|
*
|
|
* marg pointer to the packet, either a data buffer or an mbuf chain
|
|
* buflen buffer length, if marg is a data buffer
|
|
* cpfn a function that can copy marg into the listener's buffer
|
|
* pktlen length of the packet
|
|
* rcvif either NULL or the interface the packet came in on.
|
|
*/
|
|
static inline void
|
|
bpf_deliver(struct bpf_if *bp, void *(*cpfn)(void *, const void *, size_t),
|
|
void *marg, u_int pktlen, u_int buflen, struct ifnet *rcvif)
|
|
{
|
|
u_int slen;
|
|
struct bpf_d *d;
|
|
struct timespec ts;
|
|
int gottime = 0;
|
|
|
|
for (d = bp->bif_dlist; d != 0; d = d->bd_next) {
|
|
if (!d->bd_seesent && (rcvif == NULL))
|
|
continue;
|
|
++d->bd_rcount;
|
|
++bpf_gstats.bs_recv;
|
|
slen = bpf_filter(d->bd_filter, marg, pktlen, buflen);
|
|
if (slen != 0) {
|
|
if(!gottime) {
|
|
nanotime(&ts);
|
|
gottime = 1;
|
|
}
|
|
catchpacket(d, marg, pktlen, slen, cpfn, &ts);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Incoming linkage from device drivers, when the head of the packet is in
|
|
* a buffer, and the tail is in an mbuf chain.
|
|
*/
|
|
static void
|
|
bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m)
|
|
{
|
|
u_int pktlen;
|
|
struct mbuf mb;
|
|
|
|
/* Skip outgoing duplicate packets. */
|
|
if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
|
|
m->m_flags &= ~M_PROMISC;
|
|
return;
|
|
}
|
|
|
|
pktlen = m_length(m) + dlen;
|
|
|
|
/*
|
|
* Craft on-stack mbuf suitable for passing to bpf_filter.
|
|
* Note that we cut corners here; we only setup what's
|
|
* absolutely needed--this mbuf should never go anywhere else.
|
|
*/
|
|
(void)memset(&mb, 0, sizeof(mb));
|
|
mb.m_next = m;
|
|
mb.m_data = data;
|
|
mb.m_len = dlen;
|
|
|
|
bpf_deliver(bp, bpf_mcpy, &mb, pktlen, 0, m->m_pkthdr.rcvif);
|
|
}
|
|
|
|
/*
|
|
* Incoming linkage from device drivers, when packet is in an mbuf chain.
|
|
*/
|
|
static void
|
|
bpf_mtap(struct bpf_if *bp, struct mbuf *m)
|
|
{
|
|
void *(*cpfn)(void *, const void *, size_t);
|
|
u_int pktlen, buflen;
|
|
void *marg;
|
|
|
|
/* Skip outgoing duplicate packets. */
|
|
if ((m->m_flags & M_PROMISC) != 0 && m->m_pkthdr.rcvif == NULL) {
|
|
m->m_flags &= ~M_PROMISC;
|
|
return;
|
|
}
|
|
|
|
pktlen = m_length(m);
|
|
|
|
if (pktlen == m->m_len) {
|
|
cpfn = (void *)memcpy;
|
|
marg = mtod(m, void *);
|
|
buflen = pktlen;
|
|
} else {
|
|
cpfn = bpf_mcpy;
|
|
marg = m;
|
|
buflen = 0;
|
|
}
|
|
|
|
bpf_deliver(bp, cpfn, marg, pktlen, buflen, m->m_pkthdr.rcvif);
|
|
}
|
|
|
|
/*
|
|
* We need to prepend the address family as
|
|
* a four byte field. Cons up a dummy header
|
|
* to pacify bpf. This is safe because bpf
|
|
* will only read from the mbuf (i.e., it won't
|
|
* try to free it or keep a pointer a to it).
|
|
*/
|
|
static void
|
|
bpf_mtap_af(struct bpf_if *bp, uint32_t af, struct mbuf *m)
|
|
{
|
|
struct mbuf m0;
|
|
|
|
m0.m_flags = 0;
|
|
m0.m_next = m;
|
|
m0.m_len = 4;
|
|
m0.m_data = (char *)⁡
|
|
|
|
bpf_mtap(bp, &m0);
|
|
}
|
|
|
|
static void
|
|
bpf_mtap_et(struct bpf_if *bp, uint16_t et, struct mbuf *m)
|
|
{
|
|
struct mbuf m0;
|
|
|
|
m0.m_flags = 0;
|
|
m0.m_next = m;
|
|
m0.m_len = 14;
|
|
m0.m_data = m0.m_dat;
|
|
|
|
((uint32_t *)m0.m_data)[0] = 0;
|
|
((uint32_t *)m0.m_data)[1] = 0;
|
|
((uint32_t *)m0.m_data)[2] = 0;
|
|
((uint16_t *)m0.m_data)[6] = et;
|
|
|
|
bpf_mtap(bp, &m0);
|
|
}
|
|
|
|
/*
|
|
* Put the SLIP pseudo-"link header" in place.
|
|
* Note this M_PREPEND() should never fail,
|
|
* swince we know we always have enough space
|
|
* in the input buffer.
|
|
*/
|
|
static void
|
|
bpf_mtap_sl_in(struct bpf_if *bp, u_char *chdr, struct mbuf **m)
|
|
{
|
|
int s;
|
|
u_char *hp;
|
|
|
|
M_PREPEND(*m, SLIP_HDRLEN, M_DONTWAIT);
|
|
if (*m == NULL)
|
|
return;
|
|
|
|
hp = mtod(*m, u_char *);
|
|
hp[SLX_DIR] = SLIPDIR_IN;
|
|
(void)memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN);
|
|
|
|
s = splnet();
|
|
bpf_mtap(bp, *m);
|
|
splx(s);
|
|
|
|
m_adj(*m, SLIP_HDRLEN);
|
|
}
|
|
|
|
/*
|
|
* Put the SLIP pseudo-"link header" in
|
|
* place. The compressed header is now
|
|
* at the beginning of the mbuf.
|
|
*/
|
|
static void
|
|
bpf_mtap_sl_out(struct bpf_if *bp, u_char *chdr, struct mbuf *m)
|
|
{
|
|
struct mbuf m0;
|
|
u_char *hp;
|
|
int s;
|
|
|
|
m0.m_flags = 0;
|
|
m0.m_next = m;
|
|
m0.m_data = m0.m_dat;
|
|
m0.m_len = SLIP_HDRLEN;
|
|
|
|
hp = mtod(&m0, u_char *);
|
|
|
|
hp[SLX_DIR] = SLIPDIR_OUT;
|
|
(void)memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN);
|
|
|
|
s = splnet();
|
|
bpf_mtap(bp, &m0);
|
|
splx(s);
|
|
m_freem(m);
|
|
}
|
|
|
|
/*
|
|
* Move the packet data from interface memory (pkt) into the
|
|
* store buffer. Return 1 if it's time to wakeup a listener (buffer full),
|
|
* otherwise 0. "copy" is the routine called to do the actual data
|
|
* transfer. memcpy is passed in to copy contiguous chunks, while
|
|
* bpf_mcpy is passed in to copy mbuf chains. In the latter case,
|
|
* pkt is really an mbuf.
|
|
*/
|
|
static void
|
|
catchpacket(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen,
|
|
void *(*cpfn)(void *, const void *, size_t), struct timespec *ts)
|
|
{
|
|
struct bpf_hdr *hp;
|
|
int totlen, curlen;
|
|
int hdrlen = d->bd_bif->bif_hdrlen;
|
|
int do_wakeup = 0;
|
|
|
|
++d->bd_ccount;
|
|
++bpf_gstats.bs_capt;
|
|
/*
|
|
* Figure out how many bytes to move. If the packet is
|
|
* greater or equal to the snapshot length, transfer that
|
|
* much. Otherwise, transfer the whole packet (unless
|
|
* we hit the buffer size limit).
|
|
*/
|
|
totlen = hdrlen + min(snaplen, pktlen);
|
|
if (totlen > d->bd_bufsize)
|
|
totlen = d->bd_bufsize;
|
|
|
|
/*
|
|
* Round up the end of the previous packet to the next longword.
|
|
*/
|
|
curlen = BPF_WORDALIGN(d->bd_slen);
|
|
if (curlen + totlen > d->bd_bufsize) {
|
|
/*
|
|
* This packet will overflow the storage buffer.
|
|
* Rotate the buffers if we can, then wakeup any
|
|
* pending reads.
|
|
*/
|
|
if (d->bd_fbuf == 0) {
|
|
/*
|
|
* We haven't completed the previous read yet,
|
|
* so drop the packet.
|
|
*/
|
|
++d->bd_dcount;
|
|
++bpf_gstats.bs_drop;
|
|
return;
|
|
}
|
|
ROTATE_BUFFERS(d);
|
|
do_wakeup = 1;
|
|
curlen = 0;
|
|
} else if (d->bd_immediate || d->bd_state == BPF_TIMED_OUT) {
|
|
/*
|
|
* Immediate mode is set, or the read timeout has
|
|
* already expired during a select call. A packet
|
|
* arrived, so the reader should be woken up.
|
|
*/
|
|
do_wakeup = 1;
|
|
}
|
|
|
|
/*
|
|
* Append the bpf header.
|
|
*/
|
|
hp = (struct bpf_hdr *)((char *)d->bd_sbuf + curlen);
|
|
hp->bh_tstamp.tv_sec = ts->tv_sec;
|
|
hp->bh_tstamp.tv_usec = ts->tv_nsec / 1000;
|
|
hp->bh_datalen = pktlen;
|
|
hp->bh_hdrlen = hdrlen;
|
|
/*
|
|
* Copy the packet data into the store buffer and update its length.
|
|
*/
|
|
(*cpfn)((u_char *)hp + hdrlen, pkt, (hp->bh_caplen = totlen - hdrlen));
|
|
d->bd_slen = curlen + totlen;
|
|
|
|
/*
|
|
* Call bpf_wakeup after bd_slen has been updated so that kevent(2)
|
|
* will cause filt_bpfread() to be called with it adjusted.
|
|
*/
|
|
if (do_wakeup)
|
|
bpf_wakeup(d);
|
|
}
|
|
|
|
/*
|
|
* Initialize all nonzero fields of a descriptor.
|
|
*/
|
|
static int
|
|
bpf_allocbufs(struct bpf_d *d)
|
|
{
|
|
|
|
d->bd_fbuf = malloc(d->bd_bufsize, M_DEVBUF, M_NOWAIT);
|
|
if (!d->bd_fbuf)
|
|
return (ENOBUFS);
|
|
d->bd_sbuf = malloc(d->bd_bufsize, M_DEVBUF, M_NOWAIT);
|
|
if (!d->bd_sbuf) {
|
|
free(d->bd_fbuf, M_DEVBUF);
|
|
return (ENOBUFS);
|
|
}
|
|
d->bd_slen = 0;
|
|
d->bd_hlen = 0;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Free buffers currently in use by a descriptor.
|
|
* Called on close.
|
|
*/
|
|
static void
|
|
bpf_freed(struct bpf_d *d)
|
|
{
|
|
/*
|
|
* We don't need to lock out interrupts since this descriptor has
|
|
* been detached from its interface and it yet hasn't been marked
|
|
* free.
|
|
*/
|
|
if (d->bd_sbuf != 0) {
|
|
free(d->bd_sbuf, M_DEVBUF);
|
|
if (d->bd_hbuf != 0)
|
|
free(d->bd_hbuf, M_DEVBUF);
|
|
if (d->bd_fbuf != 0)
|
|
free(d->bd_fbuf, M_DEVBUF);
|
|
}
|
|
if (d->bd_filter)
|
|
free(d->bd_filter, M_DEVBUF);
|
|
}
|
|
|
|
/*
|
|
* Attach an interface to bpf. dlt is the link layer type;
|
|
* hdrlen is the fixed size of the link header for the specified dlt
|
|
* (variable length headers not yet supported).
|
|
*/
|
|
static void
|
|
bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp)
|
|
{
|
|
struct bpf_if *bp;
|
|
bp = malloc(sizeof(*bp), M_DEVBUF, M_DONTWAIT);
|
|
if (bp == 0)
|
|
panic("bpfattach");
|
|
|
|
bp->bif_dlist = 0;
|
|
bp->bif_driverp = driverp;
|
|
bp->bif_ifp = ifp;
|
|
bp->bif_dlt = dlt;
|
|
|
|
bp->bif_next = bpf_iflist;
|
|
bpf_iflist = bp;
|
|
|
|
*bp->bif_driverp = 0;
|
|
|
|
/*
|
|
* Compute the length of the bpf header. This is not necessarily
|
|
* equal to SIZEOF_BPF_HDR because we want to insert spacing such
|
|
* that the network layer header begins on a longword boundary (for
|
|
* performance reasons and to alleviate alignment restrictions).
|
|
*/
|
|
bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
|
|
|
|
#if 0
|
|
printf("bpf: %s attached\n", ifp->if_xname);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Remove an interface from bpf.
|
|
*/
|
|
static void
|
|
bpfdetach(struct ifnet *ifp)
|
|
{
|
|
struct bpf_if *bp, **pbp;
|
|
struct bpf_d *d;
|
|
int s;
|
|
|
|
/* Nuke the vnodes for any open instances */
|
|
LIST_FOREACH(d, &bpf_list, bd_list) {
|
|
if (d->bd_bif != NULL && d->bd_bif->bif_ifp == ifp) {
|
|
/*
|
|
* Detach the descriptor from an interface now.
|
|
* It will be free'ed later by close routine.
|
|
*/
|
|
s = splnet();
|
|
d->bd_promisc = 0; /* we can't touch device. */
|
|
bpf_detachd(d);
|
|
splx(s);
|
|
}
|
|
}
|
|
|
|
again:
|
|
for (bp = bpf_iflist, pbp = &bpf_iflist;
|
|
bp != NULL; pbp = &bp->bif_next, bp = bp->bif_next) {
|
|
if (bp->bif_ifp == ifp) {
|
|
*pbp = bp->bif_next;
|
|
free(bp, M_DEVBUF);
|
|
goto again;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Change the data link type of a interface.
|
|
*/
|
|
static void
|
|
bpf_change_type(struct ifnet *ifp, u_int dlt, u_int hdrlen)
|
|
{
|
|
struct bpf_if *bp;
|
|
|
|
for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
|
|
if (bp->bif_driverp == &ifp->if_bpf)
|
|
break;
|
|
}
|
|
if (bp == NULL)
|
|
panic("bpf_change_type");
|
|
|
|
bp->bif_dlt = dlt;
|
|
|
|
/*
|
|
* Compute the length of the bpf header. This is not necessarily
|
|
* equal to SIZEOF_BPF_HDR because we want to insert spacing such
|
|
* that the network layer header begins on a longword boundary (for
|
|
* performance reasons and to alleviate alignment restrictions).
|
|
*/
|
|
bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
|
|
}
|
|
|
|
/*
|
|
* Get a list of available data link type of the interface.
|
|
*/
|
|
static int
|
|
bpf_getdltlist(struct bpf_d *d, struct bpf_dltlist *bfl)
|
|
{
|
|
int n, error;
|
|
struct ifnet *ifp;
|
|
struct bpf_if *bp;
|
|
|
|
ifp = d->bd_bif->bif_ifp;
|
|
n = 0;
|
|
error = 0;
|
|
for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
|
|
if (bp->bif_ifp != ifp)
|
|
continue;
|
|
if (bfl->bfl_list != NULL) {
|
|
if (n >= bfl->bfl_len)
|
|
return ENOMEM;
|
|
error = copyout(&bp->bif_dlt,
|
|
bfl->bfl_list + n, sizeof(u_int));
|
|
}
|
|
n++;
|
|
}
|
|
bfl->bfl_len = n;
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Set the data link type of a BPF instance.
|
|
*/
|
|
static int
|
|
bpf_setdlt(struct bpf_d *d, u_int dlt)
|
|
{
|
|
int s, error, opromisc;
|
|
struct ifnet *ifp;
|
|
struct bpf_if *bp;
|
|
|
|
if (d->bd_bif->bif_dlt == dlt)
|
|
return 0;
|
|
ifp = d->bd_bif->bif_ifp;
|
|
for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
|
|
if (bp->bif_ifp == ifp && bp->bif_dlt == dlt)
|
|
break;
|
|
}
|
|
if (bp == NULL)
|
|
return EINVAL;
|
|
s = splnet();
|
|
opromisc = d->bd_promisc;
|
|
bpf_detachd(d);
|
|
bpf_attachd(d, bp);
|
|
reset_d(d);
|
|
if (opromisc) {
|
|
error = ifpromisc(bp->bif_ifp, 1);
|
|
if (error)
|
|
printf("%s: bpf_setdlt: ifpromisc failed (%d)\n",
|
|
bp->bif_ifp->if_xname, error);
|
|
else
|
|
d->bd_promisc = 1;
|
|
}
|
|
splx(s);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
sysctl_net_bpf_maxbufsize(SYSCTLFN_ARGS)
|
|
{
|
|
int newsize, error;
|
|
struct sysctlnode node;
|
|
|
|
node = *rnode;
|
|
node.sysctl_data = &newsize;
|
|
newsize = bpf_maxbufsize;
|
|
error = sysctl_lookup(SYSCTLFN_CALL(&node));
|
|
if (error || newp == NULL)
|
|
return (error);
|
|
|
|
if (newsize < BPF_MINBUFSIZE || newsize > BPF_MAXBUFSIZE)
|
|
return (EINVAL);
|
|
|
|
bpf_maxbufsize = newsize;
|
|
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
sysctl_net_bpf_peers(SYSCTLFN_ARGS)
|
|
{
|
|
int error, elem_count;
|
|
struct bpf_d *dp;
|
|
struct bpf_d_ext dpe;
|
|
size_t len, needed, elem_size, out_size;
|
|
char *sp;
|
|
|
|
if (namelen == 1 && name[0] == CTL_QUERY)
|
|
return (sysctl_query(SYSCTLFN_CALL(rnode)));
|
|
|
|
if (namelen != 2)
|
|
return (EINVAL);
|
|
|
|
/* BPF peers is privileged information. */
|
|
error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_INTERFACE,
|
|
KAUTH_REQ_NETWORK_INTERFACE_GETPRIV, NULL, NULL, NULL);
|
|
if (error)
|
|
return (EPERM);
|
|
|
|
len = (oldp != NULL) ? *oldlenp : 0;
|
|
sp = oldp;
|
|
elem_size = name[0];
|
|
elem_count = name[1];
|
|
out_size = MIN(sizeof(dpe), elem_size);
|
|
needed = 0;
|
|
|
|
if (elem_size < 1 || elem_count < 0)
|
|
return (EINVAL);
|
|
|
|
mutex_enter(&bpf_mtx);
|
|
LIST_FOREACH(dp, &bpf_list, bd_list) {
|
|
if (len >= elem_size && elem_count > 0) {
|
|
#define BPF_EXT(field) dpe.bde_ ## field = dp->bd_ ## field
|
|
BPF_EXT(bufsize);
|
|
BPF_EXT(promisc);
|
|
BPF_EXT(promisc);
|
|
BPF_EXT(state);
|
|
BPF_EXT(immediate);
|
|
BPF_EXT(hdrcmplt);
|
|
BPF_EXT(seesent);
|
|
BPF_EXT(pid);
|
|
BPF_EXT(rcount);
|
|
BPF_EXT(dcount);
|
|
BPF_EXT(ccount);
|
|
#undef BPF_EXT
|
|
if (dp->bd_bif)
|
|
(void)strlcpy(dpe.bde_ifname,
|
|
dp->bd_bif->bif_ifp->if_xname,
|
|
IFNAMSIZ - 1);
|
|
else
|
|
dpe.bde_ifname[0] = '\0';
|
|
|
|
error = copyout(&dpe, sp, out_size);
|
|
if (error)
|
|
break;
|
|
sp += elem_size;
|
|
len -= elem_size;
|
|
}
|
|
needed += elem_size;
|
|
if (elem_count > 0 && elem_count != INT_MAX)
|
|
elem_count--;
|
|
}
|
|
mutex_exit(&bpf_mtx);
|
|
|
|
*oldlenp = needed;
|
|
|
|
return (error);
|
|
}
|
|
|
|
SYSCTL_SETUP(sysctl_net_bpf_setup, "sysctl net.bpf subtree setup")
|
|
{
|
|
const struct sysctlnode *node;
|
|
|
|
sysctl_createv(clog, 0, NULL, NULL,
|
|
CTLFLAG_PERMANENT,
|
|
CTLTYPE_NODE, "net", NULL,
|
|
NULL, 0, NULL, 0,
|
|
CTL_NET, CTL_EOL);
|
|
|
|
node = NULL;
|
|
sysctl_createv(clog, 0, NULL, &node,
|
|
CTLFLAG_PERMANENT,
|
|
CTLTYPE_NODE, "bpf",
|
|
SYSCTL_DESCR("BPF options"),
|
|
NULL, 0, NULL, 0,
|
|
CTL_NET, CTL_CREATE, CTL_EOL);
|
|
if (node != NULL) {
|
|
sysctl_createv(clog, 0, NULL, NULL,
|
|
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
|
|
CTLTYPE_INT, "maxbufsize",
|
|
SYSCTL_DESCR("Maximum size for data capture buffer"),
|
|
sysctl_net_bpf_maxbufsize, 0, &bpf_maxbufsize, 0,
|
|
CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL);
|
|
sysctl_createv(clog, 0, NULL, NULL,
|
|
CTLFLAG_PERMANENT,
|
|
CTLTYPE_STRUCT, "stats",
|
|
SYSCTL_DESCR("BPF stats"),
|
|
NULL, 0, &bpf_gstats, sizeof(bpf_gstats),
|
|
CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL);
|
|
sysctl_createv(clog, 0, NULL, NULL,
|
|
CTLFLAG_PERMANENT,
|
|
CTLTYPE_STRUCT, "peers",
|
|
SYSCTL_DESCR("BPF peers"),
|
|
sysctl_net_bpf_peers, 0, NULL, 0,
|
|
CTL_NET, node->sysctl_num, CTL_CREATE, CTL_EOL);
|
|
}
|
|
|
|
}
|
|
|
|
struct bpf_ops bpf_ops_kernel = {
|
|
.bpf_attach = bpfattach,
|
|
.bpf_detach = bpfdetach,
|
|
.bpf_change_type = bpf_change_type,
|
|
|
|
.bpf_tap = bpf_tap,
|
|
.bpf_mtap = bpf_mtap,
|
|
.bpf_mtap2 = bpf_mtap2,
|
|
.bpf_mtap_af = bpf_mtap_af,
|
|
.bpf_mtap_et = bpf_mtap_et,
|
|
.bpf_mtap_sl_in = bpf_mtap_sl_in,
|
|
.bpf_mtap_sl_out = bpf_mtap_sl_out,
|
|
};
|
|
|
|
MODULE(MODULE_CLASS_DRIVER, bpf, NULL);
|
|
|
|
static int
|
|
bpf_modcmd(modcmd_t cmd, void *arg)
|
|
{
|
|
devmajor_t bmajor, cmajor;
|
|
int error;
|
|
|
|
bmajor = cmajor = NODEVMAJOR;
|
|
|
|
switch (cmd) {
|
|
case MODULE_CMD_INIT:
|
|
bpfilterattach(0);
|
|
error = devsw_attach("bpf", NULL, &bmajor,
|
|
&bpf_cdevsw, &cmajor);
|
|
if (error == EEXIST)
|
|
error = 0; /* maybe built-in ... improve eventually */
|
|
if (error)
|
|
break;
|
|
|
|
bpf_ops_handover_enter(&bpf_ops_kernel);
|
|
atomic_swap_ptr(&bpf_ops, &bpf_ops_kernel);
|
|
bpf_ops_handover_exit();
|
|
break;
|
|
|
|
case MODULE_CMD_FINI:
|
|
/*
|
|
* bpf_ops is not (yet) referenced in the callers before
|
|
* attach. maybe other issues too. "safety first".
|
|
*/
|
|
error = EOPNOTSUPP;
|
|
break;
|
|
|
|
default:
|
|
error = ENOTTY;
|
|
break;
|
|
}
|
|
|
|
return error;
|
|
}
|