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Diffstat (limited to 'sys/net/bpf.c')
| -rw-r--r-- | sys/net/bpf.c | 1320 |
1 files changed, 1320 insertions, 0 deletions
diff --git a/sys/net/bpf.c b/sys/net/bpf.c new file mode 100644 index 0000000..3ac4283 --- /dev/null +++ b/sys/net/bpf.c @@ -0,0 +1,1320 @@ +/* + * Copyright (c) 1990, 1991, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from the Stanford/CMU enet packet filter, + * (net/enet.c) distributed as part of 4.3BSD, and code contributed + * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence + * Berkeley Laboratory. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)bpf.c 8.2 (Berkeley) 3/28/94 + * + * $FreeBSD$ + */ + +#include "bpf.h" + +#ifndef __GNUC__ +#define inline +#else +#define inline __inline +#endif + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/conf.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/time.h> +#include <sys/proc.h> +#include <sys/signalvar.h> +#include <sys/filio.h> +#include <sys/sockio.h> +#include <sys/ttycom.h> +#include <sys/filedesc.h> + +#if defined(sparc) && BSD < 199103 +#include <sys/stream.h> +#endif +#include <sys/poll.h> + +#include <sys/socket.h> +#include <sys/vnode.h> + +#include <net/if.h> +#include <net/bpf.h> +#include <net/bpfdesc.h> + +#include <netinet/in.h> +#include <netinet/if_ether.h> +#include <sys/kernel.h> +#include <sys/sysctl.h> + +MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); + +#if NBPF > 0 + +/* + * Older BSDs don't have kernel malloc. + */ +#if BSD < 199103 +extern bcopy(); +static caddr_t bpf_alloc(); +#include <net/bpf_compat.h> +#define BPF_BUFSIZE (MCLBYTES-8) +#define UIOMOVE(cp, len, code, uio) uiomove(cp, len, code, uio) +#else +#define BPF_BUFSIZE 4096 +#define UIOMOVE(cp, len, code, uio) uiomove(cp, len, uio) +#endif + +#define PRINET 26 /* interruptible */ + +/* + * The default read buffer size is patchable. + */ +static int bpf_bufsize = BPF_BUFSIZE; +SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW, + &bpf_bufsize, 0, ""); + +/* + * bpf_iflist is the list of interfaces; each corresponds to an ifnet + */ +static struct bpf_if *bpf_iflist; + +static int bpf_allocbufs __P((struct bpf_d *)); +static void bpf_attachd __P((struct bpf_d *d, struct bpf_if *bp)); +static void bpf_detachd __P((struct bpf_d *d)); +static void bpf_freed __P((struct bpf_d *)); +static void bpf_mcopy __P((const void *, void *, size_t)); +static int bpf_movein __P((struct uio *, int, + struct mbuf **, struct sockaddr *, int *)); +static int bpf_setif __P((struct bpf_d *, struct ifreq *)); +static inline void + bpf_wakeup __P((struct bpf_d *)); +static void catchpacket __P((struct bpf_d *, u_char *, u_int, + u_int, void (*)(const void *, void *, size_t))); +static void reset_d __P((struct bpf_d *)); +static int bpf_setf __P((struct bpf_d *, struct bpf_program *)); + +static d_open_t bpfopen; +static d_close_t bpfclose; +static d_read_t bpfread; +static d_write_t bpfwrite; +static d_ioctl_t bpfioctl; +static d_poll_t bpfpoll; + +#define CDEV_MAJOR 23 +static struct cdevsw bpf_cdevsw = { + /* open */ bpfopen, + /* close */ bpfclose, + /* read */ bpfread, + /* write */ bpfwrite, + /* ioctl */ bpfioctl, + /* poll */ bpfpoll, + /* mmap */ nommap, + /* strategy */ nostrategy, + /* name */ "bpf", + /* maj */ CDEV_MAJOR, + /* dump */ nodump, + /* psize */ nopsize, + /* flags */ 0, + /* bmaj */ -1 +}; + + +static int +bpf_movein(uio, linktype, mp, sockp, datlen) + register struct uio *uio; + int linktype, *datlen; + register struct mbuf **mp; + register struct sockaddr *sockp; +{ + struct mbuf *m; + int error; + int len; + int hlen; + + /* + * Build a sockaddr based on the data link layer type. + * We do this at this level because the ethernet header + * is copied directly into the data field of the sockaddr. + * In the case of SLIP, there is no header and the packet + * is forwarded as is. + * Also, we are careful to leave room at the front of the mbuf + * for the link level header. + */ + switch (linktype) { + + case DLT_SLIP: + sockp->sa_family = AF_INET; + hlen = 0; + break; + + case DLT_EN10MB: + sockp->sa_family = AF_UNSPEC; + /* XXX Would MAXLINKHDR be better? */ + hlen = sizeof(struct ether_header); + break; + + case DLT_FDDI: +#if defined(__FreeBSD__) || defined(__bsdi__) + sockp->sa_family = AF_IMPLINK; + hlen = 0; +#else + sockp->sa_family = AF_UNSPEC; + /* XXX 4(FORMAC)+6(dst)+6(src)+3(LLC)+5(SNAP) */ + hlen = 24; +#endif + break; + + case DLT_RAW: + case DLT_NULL: + sockp->sa_family = AF_UNSPEC; + hlen = 0; + break; + +#ifdef __FreeBSD__ + case DLT_ATM_RFC1483: + /* + * en atm driver requires 4-byte atm pseudo header. + * though it isn't standard, vpi:vci needs to be + * specified anyway. + */ + sockp->sa_family = AF_UNSPEC; + hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */ + break; +#endif + + default: + return (EIO); + } + + len = uio->uio_resid; + *datlen = len - hlen; + if ((unsigned)len > MCLBYTES) + return (EIO); + + MGETHDR(m, M_WAIT, MT_DATA); + if (m == 0) + return (ENOBUFS); + if (len > MHLEN) { +#if BSD >= 199103 + MCLGET(m, M_WAIT); + if ((m->m_flags & M_EXT) == 0) { +#else + MCLGET(m); + if (m->m_len != MCLBYTES) { +#endif + error = ENOBUFS; + goto bad; + } + } + m->m_pkthdr.len = m->m_len = len; + m->m_pkthdr.rcvif = NULL; + *mp = m; + /* + * Make room for link header. + */ + if (hlen != 0) { + m->m_pkthdr.len -= hlen; + m->m_len -= hlen; +#if BSD >= 199103 + m->m_data += hlen; /* XXX */ +#else + m->m_off += hlen; +#endif + error = UIOMOVE((caddr_t)sockp->sa_data, hlen, UIO_WRITE, uio); + if (error) + goto bad; + } + error = UIOMOVE(mtod(m, caddr_t), len - hlen, UIO_WRITE, uio); + if (!error) + return (0); + bad: + m_freem(m); + return (error); +} + +/* + * Attach file to the bpf interface, i.e. make d listen on bp. + * Must be called at splimp. + */ +static void +bpf_attachd(d, bp) + struct bpf_d *d; + struct bpf_if *bp; +{ + /* + * Point d at bp, and add d to the interface's list of listeners. + * Finally, point the driver's bpf cookie at the interface so + * it will divert packets to bpf. + */ + d->bd_bif = bp; + d->bd_next = bp->bif_dlist; + bp->bif_dlist = d; + + bp->bif_ifp->if_bpf = bp; +} + +/* + * Detach a file from its interface. + */ +static void +bpf_detachd(d) + struct bpf_d *d; +{ + struct bpf_d **p; + struct bpf_if *bp; + + bp = d->bd_bif; + /* + * Check if this descriptor had requested promiscuous mode. + * If so, turn it off. + */ + if (d->bd_promisc) { + d->bd_promisc = 0; + if (ifpromisc(bp->bif_ifp, 0)) + /* + * Something is really wrong if we were able to put + * the driver into promiscuous mode, but can't + * take it out. + */ + panic("bpf: ifpromisc failed"); + } + /* Remove d from the interface's descriptor list. */ + p = &bp->bif_dlist; + while (*p != d) { + p = &(*p)->bd_next; + if (*p == 0) + panic("bpf_detachd: descriptor not in list"); + } + *p = (*p)->bd_next; + if (bp->bif_dlist == 0) + /* + * Let the driver know that there are no more listeners. + */ + d->bd_bif->bif_ifp->if_bpf = 0; + d->bd_bif = 0; +} + +/* + * Open ethernet device. Returns ENXIO for illegal minor device number, + * EBUSY if file is open by another process. + */ +/* ARGSUSED */ +static int +bpfopen(dev, flags, fmt, p) + dev_t dev; + int flags; + int fmt; + struct proc *p; +{ + register struct bpf_d *d; + + if (p->p_prison) + return (EPERM); + + d = dev->si_drv1; + /* + * Each minor can be opened by only one process. If the requested + * minor is in use, return EBUSY. + */ + if (d) + return (EBUSY); + make_dev(&bpf_cdevsw, minor(dev), 0, 0, 0600, "bpf%d", lminor(dev)); + MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK); + bzero(d, sizeof(*d)); + dev->si_drv1 = d; + d->bd_bufsize = bpf_bufsize; + d->bd_sig = SIGIO; + + return (0); +} + +/* + * Close the descriptor by detaching it from its interface, + * deallocating its buffers, and marking it free. + */ +/* ARGSUSED */ +static int +bpfclose(dev, flags, fmt, p) + dev_t dev; + int flags; + int fmt; + struct proc *p; +{ + register struct bpf_d *d = dev->si_drv1; + register int s; + + funsetown(d->bd_sigio); + s = splimp(); + if (d->bd_bif) + bpf_detachd(d); + splx(s); + bpf_freed(d); + dev->si_drv1 = 0; + FREE(d, M_BPF); + + return (0); +} + +/* + * Support for SunOS, which does not have tsleep. + */ +#if BSD < 199103 +static +bpf_timeout(arg) + caddr_t arg; +{ + struct bpf_d *d = (struct bpf_d *)arg; + d->bd_timedout = 1; + wakeup(arg); +} + +#define BPF_SLEEP(chan, pri, s, t) bpf_sleep((struct bpf_d *)chan) + +int +bpf_sleep(d) + register struct bpf_d *d; +{ + register int rto = d->bd_rtout; + register int st; + + if (rto != 0) { + d->bd_timedout = 0; + timeout(bpf_timeout, (caddr_t)d, rto); + } + st = sleep((caddr_t)d, PRINET|PCATCH); + if (rto != 0) { + if (d->bd_timedout == 0) + untimeout(bpf_timeout, (caddr_t)d); + else if (st == 0) + return EWOULDBLOCK; + } + return (st != 0) ? EINTR : 0; +} +#else +#define BPF_SLEEP tsleep +#endif + +/* + * Rotate the packet buffers in descriptor d. Move the store buffer + * into the hold slot, and the free buffer into the store slot. + * Zero the length of the new store buffer. + */ +#define ROTATE_BUFFERS(d) \ + (d)->bd_hbuf = (d)->bd_sbuf; \ + (d)->bd_hlen = (d)->bd_slen; \ + (d)->bd_sbuf = (d)->bd_fbuf; \ + (d)->bd_slen = 0; \ + (d)->bd_fbuf = 0; +/* + * bpfread - read next chunk of packets from buffers + */ +static int +bpfread(dev, uio, ioflag) + dev_t dev; + register struct uio *uio; + int ioflag; +{ + register struct bpf_d *d = dev->si_drv1; + int error; + int s; + + /* + * Restrict application to use a buffer the same size as + * as kernel buffers. + */ + if (uio->uio_resid != d->bd_bufsize) + return (EINVAL); + + s = splimp(); + /* + * If the hold buffer is empty, then do a timed sleep, which + * ends when the timeout expires or when enough packets + * have arrived to fill the store buffer. + */ + while (d->bd_hbuf == 0) { + if (d->bd_immediate && d->bd_slen != 0) { + /* + * 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; + } + if (ioflag & IO_NDELAY) + error = EWOULDBLOCK; + else + error = BPF_SLEEP((caddr_t)d, PRINET|PCATCH, "bpf", + d->bd_rtout); + if (error == EINTR || error == ERESTART) { + splx(s); + 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); + return (0); + } + ROTATE_BUFFERS(d); + break; + } + } + /* + * 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_READ, uio); + + s = splimp(); + d->bd_fbuf = d->bd_hbuf; + d->bd_hbuf = 0; + d->bd_hlen = 0; + splx(s); + + return (error); +} + + +/* + * If there are processes sleeping on this descriptor, wake them up. + */ +static inline void +bpf_wakeup(d) + register struct bpf_d *d; +{ + wakeup((caddr_t)d); + if (d->bd_async && d->bd_sig && d->bd_sigio) + pgsigio(d->bd_sigio, d->bd_sig, 0); + +#if BSD >= 199103 + selwakeup(&d->bd_sel); + /* XXX */ + d->bd_sel.si_pid = 0; +#else + if (d->bd_selproc) { + selwakeup(d->bd_selproc, (int)d->bd_selcoll); + d->bd_selcoll = 0; + d->bd_selproc = 0; + } +#endif +} + +static int +bpfwrite(dev, uio, ioflag) + dev_t dev; + struct uio *uio; + int ioflag; +{ + register struct bpf_d *d = dev->si_drv1; + struct ifnet *ifp; + struct mbuf *m; + int error, s; + static struct sockaddr dst; + int datlen; + + if (d->bd_bif == 0) + return (ENXIO); + + ifp = d->bd_bif->bif_ifp; + + if (uio->uio_resid == 0) + return (0); + + error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst, &datlen); + if (error) + return (error); + + if (datlen > ifp->if_mtu) + return (EMSGSIZE); + + if (d->bd_hdrcmplt) + dst.sa_family = pseudo_AF_HDRCMPLT; + + s = splnet(); +#if BSD >= 199103 + error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0); +#else + error = (*ifp->if_output)(ifp, m, &dst); +#endif + splx(s); + /* + * 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 splimp. + */ +static void +reset_d(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; +} + +/* + * FIONREAD Check for read packet available. + * SIOCGIFADDR Get interface address - convenient hook to driver. + * 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 + */ +/* ARGSUSED */ +static int +bpfioctl(dev, cmd, addr, flags, p) + dev_t dev; + u_long cmd; + caddr_t addr; + int flags; + struct proc *p; +{ + register struct bpf_d *d = dev->si_drv1; + int s, error = 0; + + switch (cmd) { + + default: + error = EINVAL; + break; + + /* + * Check for read packet available. + */ + case FIONREAD: + { + int n; + + s = splimp(); + n = d->bd_slen; + if (d->bd_hbuf) + n += d->bd_hlen; + splx(s); + + *(int *)addr = n; + break; + } + + case SIOCGIFADDR: + { + struct ifnet *ifp; + + if (d->bd_bif == 0) + error = EINVAL; + else { + ifp = d->bd_bif->bif_ifp; + error = (*ifp->if_ioctl)(ifp, cmd, addr); + } + break; + } + + /* + * Get buffer len [for read()]. + */ + case BIOCGBLEN: + *(u_int *)addr = d->bd_bufsize; + break; + + /* + * Set buffer length. + */ + case BIOCSBLEN: +#if BSD < 199103 + error = EINVAL; +#else + if (d->bd_bif != 0) + error = EINVAL; + else { + register 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; + } +#endif + break; + + /* + * Set link layer read filter. + */ + case BIOCSETF: + error = bpf_setf(d, (struct bpf_program *)addr); + break; + + /* + * Flush read packet buffer. + */ + case BIOCFLUSH: + s = splimp(); + 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 = splimp(); + 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 interface name. + */ + case BIOCGETIF: + if (d->bd_bif == 0) + error = EINVAL; + else { + struct ifnet *const ifp = d->bd_bif->bif_ifp; + struct ifreq *const ifr = (struct ifreq *)addr; + + snprintf(ifr->ifr_name, sizeof(ifr->ifr_name), + "%s%d", ifp->if_name, ifp->if_unit); + } + break; + + /* + * Set interface. + */ + case BIOCSETIF: + error = bpf_setif(d, (struct ifreq *)addr); + break; + + /* + * Set read timeout. + */ + case BIOCSRTIMEOUT: + { + struct timeval *tv = (struct timeval *)addr; + + /* + * Subtract 1 tick from tvtohz() since this isn't + * a one-shot timer. + */ + if ((error = itimerfix(tv)) == 0) + d->bd_rtout = tvtohz(tv) - 1; + break; + } + + /* + * Get read timeout. + */ + case BIOCGRTIMEOUT: + { + struct timeval *tv = (struct timeval *)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 = (struct bpf_stat *)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 = (struct bpf_version *)addr; + + bv->bv_major = BPF_MAJOR_VERSION; + bv->bv_minor = BPF_MINOR_VERSION; + break; + } + + /* + * Get "header already complete" flag + */ + case BIOCGHDRCMPLT: + *(u_int *)addr = d->bd_hdrcmplt; + break; + + /* + * Set "header already complete" flag + */ + case BIOCSHDRCMPLT: + d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0; + break; + + case FIONBIO: /* Non-blocking I/O */ + break; + + case FIOASYNC: /* Send signal on receive packets */ + d->bd_async = *(int *)addr; + break; + + case FIOSETOWN: + error = fsetown(*(int *)addr, &d->bd_sigio); + break; + + case FIOGETOWN: + *(int *)addr = fgetown(d->bd_sigio); + break; + + /* This is deprecated, FIOSETOWN should be used instead. */ + case TIOCSPGRP: + error = fsetown(-(*(int *)addr), &d->bd_sigio); + break; + + /* This is deprecated, FIOGETOWN should be used instead. */ + case TIOCGPGRP: + *(int *)addr = -fgetown(d->bd_sigio); + break; + + case BIOCSRSIG: /* Set receive signal */ + { + u_int sig; + + sig = *(u_int *)addr; + + if (sig >= NSIG) + error = EINVAL; + else + d->bd_sig = sig; + break; + } + case BIOCGRSIG: + *(u_int *)addr = d->bd_sig; + break; + } + 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. + */ +static int +bpf_setf(d, fp) + 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 = splimp(); + d->bd_filter = 0; + reset_d(d); + splx(s); + if (old != 0) + free((caddr_t)old, M_BPF); + return (0); + } + flen = fp->bf_len; + if (flen > BPF_MAXINSNS) + return (EINVAL); + + size = flen * sizeof(*fp->bf_insns); + fcode = (struct bpf_insn *)malloc(size, M_BPF, M_WAITOK); + if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 && + bpf_validate(fcode, (int)flen)) { + s = splimp(); + d->bd_filter = fcode; + reset_d(d); + splx(s); + if (old != 0) + free((caddr_t)old, M_BPF); + + return (0); + } + free((caddr_t)fcode, M_BPF); + 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(d, ifr) + struct bpf_d *d; + struct ifreq *ifr; +{ + struct bpf_if *bp; + int s, error; + struct ifnet *theywant; + + theywant = ifunit(ifr->ifr_name); + if (theywant == 0) + return ENXIO; + + /* + * 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 || ifp != theywant) + continue; + /* + * We found the requested interface. + * If it's not up, return an error. + * Allocate the packet buffers if we need to. + * If we're already attached to requested interface, + * just flush the buffer. + */ + if ((ifp->if_flags & IFF_UP) == 0) + return (ENETDOWN); + + if (d->bd_sbuf == 0) { + error = bpf_allocbufs(d); + if (error != 0) + return (error); + } + s = splimp(); + 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); +} + +/* + * Support for select() and poll() system calls + * + * Return true iff the specific operation will not block indefinitely. + * Otherwise, return false but make a note that a selwakeup() must be done. + */ +int +bpfpoll(dev, events, p) + register dev_t dev; + int events; + struct proc *p; +{ + register struct bpf_d *d; + register int s; + int revents = 0; + + /* + * An imitation of the FIONREAD ioctl code. + */ + d = dev->si_drv1; + + s = splimp(); + if (events & (POLLIN | POLLRDNORM)) { + if (d->bd_hlen != 0 || (d->bd_immediate && d->bd_slen != 0)) + revents |= events & (POLLIN | POLLRDNORM); + else + selrecord(p, &d->bd_sel); + } + splx(s); + return (revents); +} + +/* + * 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. + */ +void +bpf_tap(ifp, pkt, pktlen) + struct ifnet *ifp; + register u_char *pkt; + register u_int pktlen; +{ + struct bpf_if *bp; + register struct bpf_d *d; + register u_int slen; + /* + * 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. + */ + bp = ifp->if_bpf; + for (d = bp->bif_dlist; d != 0; d = d->bd_next) { + ++d->bd_rcount; + slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen); + if (slen != 0) + catchpacket(d, pkt, pktlen, slen, bcopy); + } +} + +/* + * Copy data from an mbuf chain into a buffer. This code is derived + * from m_copydata in sys/uipc_mbuf.c. + */ +static void +bpf_mcopy(src_arg, dst_arg, len) + const void *src_arg; + void *dst_arg; + register size_t len; +{ + register const struct mbuf *m; + register u_int count; + u_char *dst; + + m = src_arg; + dst = dst_arg; + while (len > 0) { + if (m == 0) + panic("bpf_mcopy"); + count = min(m->m_len, len); + bcopy(mtod(m, void *), dst, count); + m = m->m_next; + dst += count; + len -= count; + } +} + +/* + * Incoming linkage from device drivers, when packet is in an mbuf chain. + */ +void +bpf_mtap(ifp, m) + struct ifnet *ifp; + struct mbuf *m; +{ + struct bpf_if *bp = ifp->if_bpf; + struct bpf_d *d; + u_int pktlen, slen; + struct mbuf *m0; + + pktlen = 0; + for (m0 = m; m0 != 0; m0 = m0->m_next) + pktlen += m0->m_len; + + for (d = bp->bif_dlist; d != 0; d = d->bd_next) { + ++d->bd_rcount; + slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0); + if (slen != 0) + catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy); + } +} + +/* + * 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. bcopy is passed in to copy contiguous chunks, while + * bpf_mcopy is passed in to copy mbuf chains. In the latter case, + * pkt is really an mbuf. + */ +static void +catchpacket(d, pkt, pktlen, snaplen, cpfn) + register struct bpf_d *d; + register u_char *pkt; + register u_int pktlen, snaplen; + register void (*cpfn) __P((const void *, void *, size_t)); +{ + register struct bpf_hdr *hp; + register int totlen, curlen; + register int hdrlen = d->bd_bif->bif_hdrlen; + /* + * 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; + return; + } + ROTATE_BUFFERS(d); + bpf_wakeup(d); + curlen = 0; + } + else if (d->bd_immediate) + /* + * Immediate mode is set. A packet arrived so any + * reads should be woken up. + */ + bpf_wakeup(d); + + /* + * Append the bpf header. + */ + hp = (struct bpf_hdr *)(d->bd_sbuf + curlen); +#if BSD >= 199103 + microtime(&hp->bh_tstamp); +#elif defined(sun) + uniqtime(&hp->bh_tstamp); +#else + hp->bh_tstamp = time; +#endif + hp->bh_datalen = pktlen; + hp->bh_hdrlen = hdrlen; + /* + * Copy the packet data into the store buffer and update its length. + */ + (*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen)); + d->bd_slen = curlen + totlen; +} + +/* + * Initialize all nonzero fields of a descriptor. + */ +static int +bpf_allocbufs(d) + register struct bpf_d *d; +{ + d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); + if (d->bd_fbuf == 0) + return (ENOBUFS); + + d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); + if (d->bd_sbuf == 0) { + free(d->bd_fbuf, M_BPF); + 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(d) + register 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_BPF); + if (d->bd_hbuf != 0) + free(d->bd_hbuf, M_BPF); + if (d->bd_fbuf != 0) + free(d->bd_fbuf, M_BPF); + } + if (d->bd_filter) + free((caddr_t)d->bd_filter, M_BPF); +} + +/* + * Attach an interface to bpf. driverp is a pointer to a (struct bpf_if *) + * in the driver's softc; dlt is the link layer type; hdrlen is the fixed + * size of the link header (variable length headers not yet supported). + */ +void +bpfattach(ifp, dlt, hdrlen) + struct ifnet *ifp; + u_int dlt, hdrlen; +{ + struct bpf_if *bp; + bp = (struct bpf_if *)malloc(sizeof(*bp), M_BPF, M_DONTWAIT); + if (bp == 0) + panic("bpfattach"); + + bp->bif_dlist = 0; + bp->bif_ifp = ifp; + bp->bif_dlt = dlt; + + bp->bif_next = bpf_iflist; + bpf_iflist = bp; + + bp->bif_ifp->if_bpf = 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 (bootverbose) + printf("bpf: %s%d attached\n", ifp->if_name, ifp->if_unit); +} + +static void bpf_drvinit __P((void *unused)); + +static void +bpf_drvinit(unused) + void *unused; +{ + + cdevsw_add(&bpf_cdevsw); +} + +SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,bpf_drvinit,NULL) + +#else /* !BPF */ +/* + * NOP stubs to allow bpf-using drivers to load and function. + * + * A 'better' implementation would allow the core bpf functionality + * to be loaded at runtime. + */ + +void +bpf_tap(ifp, pkt, pktlen) + struct ifnet *ifp; + register u_char *pkt; + register u_int pktlen; +{ +} + +void +bpf_mtap(ifp, m) + struct ifnet *ifp; + struct mbuf *m; +{ +} + +void +bpfattach(ifp, dlt, hdrlen) + struct ifnet *ifp; + u_int dlt, hdrlen; +{ +} + +u_int +bpf_filter(pc, p, wirelen, buflen) + register const struct bpf_insn *pc; + register u_char *p; + u_int wirelen; + register u_int buflen; +{ + return -1; /* "no filter" behaviour */ +} + +#endif /* !BPF */ |
