/*- * 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. * 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 8.4 (Berkeley) 1/9/95 */ #include __FBSDID("$FreeBSD$"); #include "opt_bpf.h" #include "opt_mac.h" #include "opt_netgraph.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef BPF_JITTER #include #endif #include #include #include #include #include #include #include static MALLOC_DEFINE(M_BPF, "BPF", "BPF data"); #if defined(DEV_BPF) || defined(NETGRAPH_BPF) #define PRINET 26 /* interruptible */ #define M_SKIP_BPF M_SKIP_FIREWALL /* * bpf_iflist is a list of BPF interface structures, each corresponding to a * specific DLT. The same network interface might have several BPF interface * structures registered by different layers in the stack (i.e., 802.11 * frames, ethernet frames, etc). */ static LIST_HEAD(, bpf_if) bpf_iflist; static struct mtx bpf_mtx; /* bpf global lock */ static int bpf_bpfd_cnt; static void bpf_allocbufs(struct bpf_d *); static void bpf_attachd(struct bpf_d *, struct bpf_if *); static void bpf_detachd(struct bpf_d *); static void bpf_freed(struct bpf_d *); static void bpf_mcopy(const void *, void *, size_t); static int bpf_movein(struct uio *, int, struct ifnet *, struct mbuf **, struct sockaddr *, int *, struct bpf_insn *); static int bpf_setif(struct bpf_d *, struct ifreq *); static void bpf_timed_out(void *); static __inline void bpf_wakeup(struct bpf_d *); static void catchpacket(struct bpf_d *, u_char *, u_int, u_int, void (*)(const void *, void *, size_t), struct timeval *); static void reset_d(struct bpf_d *); static int bpf_setf(struct bpf_d *, struct bpf_program *, u_long cmd); static int bpf_getdltlist(struct bpf_d *, struct bpf_dltlist *); static int bpf_setdlt(struct bpf_d *, u_int); static void filt_bpfdetach(struct knote *); static int filt_bpfread(struct knote *, long); static void bpf_drvinit(void *); static void bpf_clone(void *, struct ucred *, char *, int, struct cdev **); static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS); SYSCTL_NODE(_net, OID_AUTO, bpf, CTLFLAG_RW, 0, "bpf sysctl"); static int bpf_bufsize = 4096; SYSCTL_INT(_net_bpf, OID_AUTO, bufsize, CTLFLAG_RW, &bpf_bufsize, 0, "Default bpf buffer size"); static int bpf_maxbufsize = BPF_MAXBUFSIZE; SYSCTL_INT(_net_bpf, OID_AUTO, maxbufsize, CTLFLAG_RW, &bpf_maxbufsize, 0, "Maximum bpf buffer size"); static int bpf_maxinsns = BPF_MAXINSNS; SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW, &bpf_maxinsns, 0, "Maximum bpf program instructions"); SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_RW, bpf_stats_sysctl, "bpf statistics portal"); 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; static d_kqfilter_t bpfkqfilter; static struct cdevsw bpf_cdevsw = { .d_version = D_VERSION, .d_open = bpfopen, .d_close = bpfclose, .d_read = bpfread, .d_write = bpfwrite, .d_ioctl = bpfioctl, .d_poll = bpfpoll, .d_name = "bpf", .d_kqfilter = bpfkqfilter, }; static struct filterops bpfread_filtops = { 1, NULL, filt_bpfdetach, filt_bpfread }; static int bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp, struct sockaddr *sockp, int *hdrlen, struct bpf_insn *wfilter) { const struct ieee80211_bpf_params *p; struct ether_header *eh; struct mbuf *m; int error; int len; int hlen; int slen; /* * 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 = ETHER_HDR_LEN; break; case DLT_FDDI: sockp->sa_family = AF_IMPLINK; hlen = 0; break; case DLT_RAW: sockp->sa_family = AF_UNSPEC; hlen = 0; break; case DLT_NULL: /* * null interface types require a 4 byte pseudo header which * corresponds to the address family of the packet. */ sockp->sa_family = AF_UNSPEC; hlen = 4; break; 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; case DLT_PPP: sockp->sa_family = AF_UNSPEC; hlen = 4; /* This should match PPP_HDRLEN */ break; case DLT_IEEE802_11: /* IEEE 802.11 wireless */ sockp->sa_family = AF_IEEE80211; hlen = 0; break; case DLT_IEEE802_11_RADIO: /* IEEE 802.11 wireless w/ phy params */ sockp->sa_family = AF_IEEE80211; sockp->sa_len = 12; /* XXX != 0 */ hlen = sizeof(struct ieee80211_bpf_params); break; default: return (EIO); } len = uio->uio_resid; if (len - hlen > ifp->if_mtu) return (EMSGSIZE); if ((unsigned)len > MCLBYTES) return (EIO); if (len > MHLEN) { m = m_getcl(M_TRYWAIT, MT_DATA, M_PKTHDR); } else { MGETHDR(m, M_TRYWAIT, MT_DATA); } if (m == NULL) return (ENOBUFS); m->m_pkthdr.len = m->m_len = len; m->m_pkthdr.rcvif = NULL; *mp = m; if (m->m_len < hlen) { error = EPERM; goto bad; } error = uiomove(mtod(m, u_char *), len, uio); if (error) goto bad; slen = bpf_filter(wfilter, mtod(m, u_char *), len, len); if (slen == 0) { error = EPERM; goto bad; } /* Check for multicast destination */ switch (linktype) { case DLT_EN10MB: eh = mtod(m, struct ether_header *); if (ETHER_IS_MULTICAST(eh->ether_dhost)) { if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost, ETHER_ADDR_LEN) == 0) m->m_flags |= M_BCAST; else m->m_flags |= M_MCAST; } break; } /* * Make room for link header, and copy it to sockaddr */ if (hlen != 0) { if (sockp->sa_family == AF_IEEE80211) { /* * Collect true length from the parameter header * NB: sockp is known to be zero'd so if we do a * short copy unspecified parameters will be * zero. * NB: packet may not be aligned after stripping * bpf params * XXX check ibp_vers */ p = mtod(m, const struct ieee80211_bpf_params *); hlen = p->ibp_len; if (hlen > sizeof(sockp->sa_data)) { error = EINVAL; goto bad; } } bcopy(m->m_data, sockp->sa_data, hlen); } *hdrlen = hlen; return (0); bad: m_freem(m); return (error); } /* * Attach file to the bpf interface, i.e. make d listen on bp. */ static void bpf_attachd(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. */ BPFIF_LOCK(bp); d->bd_bif = bp; LIST_INSERT_HEAD(&bp->bif_dlist, d, bd_next); bpf_bpfd_cnt++; BPFIF_UNLOCK(bp); } /* * Detach a file from its interface. */ static void bpf_detachd(struct bpf_d *d) { int error; struct bpf_if *bp; struct ifnet *ifp; bp = d->bd_bif; BPFIF_LOCK(bp); BPFD_LOCK(d); ifp = d->bd_bif->bif_ifp; /* * Remove d from the interface's descriptor list. */ LIST_REMOVE(d, bd_next); bpf_bpfd_cnt--; d->bd_bif = NULL; BPFD_UNLOCK(d); BPFIF_UNLOCK(bp); /* * Check if this descriptor had requested promiscuous mode. * If so, turn it off. */ if (d->bd_promisc) { d->bd_promisc = 0; error = ifpromisc(ifp, 0); if (error != 0 && error != ENXIO) { /* * ENXIO can happen if a pccard is unplugged * Something is really wrong if we were able to put * the driver into promiscuous mode, but can't * take it out. */ if_printf(bp->bif_ifp, "bpf_detach: ifpromisc failed (%d)\n", error); } } } /* * Open ethernet device. Returns ENXIO for illegal minor device number, * EBUSY if file is open by another process. */ /* ARGSUSED */ static int bpfopen(struct cdev *dev, int flags, int fmt, struct thread *td) { struct bpf_d *d; mtx_lock(&bpf_mtx); d = dev->si_drv1; /* * Each minor can be opened by only one process. If the requested * minor is in use, return EBUSY. */ if (d != NULL) { mtx_unlock(&bpf_mtx); return (EBUSY); } dev->si_drv1 = (struct bpf_d *)~0; /* mark device in use */ mtx_unlock(&bpf_mtx); if ((dev->si_flags & SI_NAMED) == 0) make_dev(&bpf_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600, "bpf%d", dev2unit(dev)); MALLOC(d, struct bpf_d *, sizeof(*d), M_BPF, M_WAITOK | M_ZERO); dev->si_drv1 = d; d->bd_bufsize = bpf_bufsize; d->bd_sig = SIGIO; d->bd_direction = BPF_D_INOUT; d->bd_pid = td->td_proc->p_pid; #ifdef MAC mac_bpfdesc_init(d); mac_bpfdesc_create(td->td_ucred, d); #endif mtx_init(&d->bd_mtx, devtoname(dev), "bpf cdev lock", MTX_DEF); callout_init(&d->bd_callout, CALLOUT_MPSAFE); knlist_init(&d->bd_sel.si_note, &d->bd_mtx, NULL, NULL, NULL); return (0); } /* * Close the descriptor by detaching it from its interface, * deallocating its buffers, and marking it free. */ /* ARGSUSED */ static int bpfclose(struct cdev *dev, int flags, int fmt, struct thread *td) { struct bpf_d *d = dev->si_drv1; BPFD_LOCK(d); if (d->bd_state == BPF_WAITING) callout_stop(&d->bd_callout); d->bd_state = BPF_IDLE; BPFD_UNLOCK(d); funsetown(&d->bd_sigio); mtx_lock(&bpf_mtx); if (d->bd_bif) bpf_detachd(d); mtx_unlock(&bpf_mtx); selwakeuppri(&d->bd_sel, PRINET); #ifdef MAC mac_bpfdesc_destroy(d); #endif /* MAC */ knlist_destroy(&d->bd_sel.si_note); bpf_freed(d); dev->si_drv1 = NULL; free(d, M_BPF); return (0); } /* * 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 = NULL; /* * bpfread - read next chunk of packets from buffers */ static int bpfread(struct cdev *dev, struct uio *uio, int ioflag) { struct bpf_d *d = dev->si_drv1; int timed_out; int error; /* * Restrict application to use a buffer the same size as * as kernel buffers. */ if (uio->uio_resid != d->bd_bufsize) return (EINVAL); BPFD_LOCK(d); d->bd_pid = curthread->td_proc->p_pid; if (d->bd_state == BPF_WAITING) callout_stop(&d->bd_callout); timed_out = (d->bd_state == BPF_TIMED_OUT); d->bd_state = BPF_IDLE; /* * 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 == NULL) { if ((d->bd_immediate || timed_out) && 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; } /* * No data is available, check to see if the bpf device * is still pointed at a real interface. If not, return * ENXIO so that the userland process knows to rebind * it before using it again. */ if (d->bd_bif == NULL) { BPFD_UNLOCK(d); return (ENXIO); } if (ioflag & O_NONBLOCK) { BPFD_UNLOCK(d); return (EWOULDBLOCK); } error = msleep(d, &d->bd_mtx, PRINET|PCATCH, "bpf", d->bd_rtout); if (error == EINTR || error == ERESTART) { BPFD_UNLOCK(d); 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) { BPFD_UNLOCK(d); return (0); } ROTATE_BUFFERS(d); break; } } /* * At this point, we know we have something in the hold slot. */ BPFD_UNLOCK(d); /* * 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); BPFD_LOCK(d); d->bd_fbuf = d->bd_hbuf; d->bd_hbuf = NULL; d->bd_hlen = 0; BPFD_UNLOCK(d); return (error); } /* * If there are processes sleeping on this descriptor, wake them up. */ static __inline void bpf_wakeup(struct bpf_d *d) { BPFD_LOCK_ASSERT(d); if (d->bd_state == BPF_WAITING) { callout_stop(&d->bd_callout); d->bd_state = BPF_IDLE; } wakeup(d); if (d->bd_async && d->bd_sig && d->bd_sigio) pgsigio(&d->bd_sigio, d->bd_sig, 0); selwakeuppri(&d->bd_sel, PRINET); KNOTE_LOCKED(&d->bd_sel.si_note, 0); } static void bpf_timed_out(void *arg) { struct bpf_d *d = (struct bpf_d *)arg; BPFD_LOCK(d); if (d->bd_state == BPF_WAITING) { d->bd_state = BPF_TIMED_OUT; if (d->bd_slen != 0) bpf_wakeup(d); } BPFD_UNLOCK(d); } static int bpfwrite(struct cdev *dev, struct uio *uio, int ioflag) { struct bpf_d *d = dev->si_drv1; struct ifnet *ifp; struct mbuf *m, *mc; struct sockaddr dst; int error, hlen; d->bd_pid = curthread->td_proc->p_pid; if (d->bd_bif == NULL) return (ENXIO); ifp = d->bd_bif->bif_ifp; if ((ifp->if_flags & IFF_UP) == 0) return (ENETDOWN); if (uio->uio_resid == 0) return (0); bzero(&dst, sizeof(dst)); m = NULL; hlen = 0; error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, ifp, &m, &dst, &hlen, d->bd_wfilter); if (error) return (error); if (d->bd_hdrcmplt) dst.sa_family = pseudo_AF_HDRCMPLT; if (d->bd_feedback) { mc = m_dup(m, M_DONTWAIT); if (mc != NULL) mc->m_pkthdr.rcvif = ifp; /* XXX Do not return the same packet twice. */ if (d->bd_direction == BPF_D_INOUT) m->m_flags |= M_SKIP_BPF; } else mc = NULL; m->m_pkthdr.len -= hlen; m->m_len -= hlen; m->m_data += hlen; /* XXX */ #ifdef MAC BPFD_LOCK(d); mac_bpfdesc_create_mbuf(d, m); if (mc != NULL) mac_bpfdesc_create_mbuf(d, mc); BPFD_UNLOCK(d); #endif error = (*ifp->if_output)(ifp, m, &dst, NULL); if (mc != NULL) { if (error == 0) (*ifp->if_input)(ifp, mc); else m_freem(mc); } return (error); } /* * Reset a descriptor by flushing its packet buffer and clearing the * receive and drop counts. */ static void reset_d(struct bpf_d *d) { mtx_assert(&d->bd_mtx, MA_OWNED); if (d->bd_hbuf) { /* Free the hold buffer. */ d->bd_fbuf = d->bd_hbuf; d->bd_hbuf = NULL; } d->bd_slen = 0; d->bd_hlen = 0; d->bd_rcount = 0; d->bd_dcount = 0; d->bd_fcount = 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. * BIOCSETWF Set ethernet write 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 * BIOCGDIRECTION Get packet direction flag * BIOCSDIRECTION Set packet direction flag * BIOCLOCK Set "locked" flag * BIOCFEEDBACK Set packet feedback mode. */ /* ARGSUSED */ static int bpfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td) { struct bpf_d *d = dev->si_drv1; int error = 0; /* * Refresh PID associated with this descriptor. */ BPFD_LOCK(d); d->bd_pid = td->td_proc->p_pid; if (d->bd_state == BPF_WAITING) callout_stop(&d->bd_callout); d->bd_state = BPF_IDLE; BPFD_UNLOCK(d); if (d->bd_locked == 1) { switch (cmd) { case BIOCGBLEN: case BIOCFLUSH: case BIOCGDLT: case BIOCGDLTLIST: case BIOCGETIF: case BIOCGRTIMEOUT: case BIOCGSTATS: case BIOCVERSION: case BIOCGRSIG: case BIOCGHDRCMPLT: case BIOCFEEDBACK: case FIONREAD: case BIOCLOCK: case BIOCSRTIMEOUT: case BIOCIMMEDIATE: case TIOCGPGRP: break; default: return (EPERM); } } switch (cmd) { default: error = EINVAL; break; /* * Check for read packet available. */ case FIONREAD: { int n; BPFD_LOCK(d); n = d->bd_slen; if (d->bd_hbuf) n += d->bd_hlen; BPFD_UNLOCK(d); *(int *)addr = n; break; } case SIOCGIFADDR: { struct ifnet *ifp; if (d->bd_bif == NULL) 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 (d->bd_bif != NULL) 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: case BIOCSETWF: error = bpf_setf(d, (struct bpf_program *)addr, cmd); break; /* * Flush read packet buffer. */ case BIOCFLUSH: BPFD_LOCK(d); reset_d(d); BPFD_UNLOCK(d); break; /* * Put interface into promiscuous mode. */ case BIOCPROMISC: if (d->bd_bif == NULL) { /* * No interface attached yet. */ error = EINVAL; break; } if (d->bd_promisc == 0) { error = ifpromisc(d->bd_bif->bif_ifp, 1); if (error == 0) d->bd_promisc = 1; } break; /* * Get current data link type. */ case BIOCGDLT: if (d->bd_bif == NULL) error = EINVAL; else *(u_int *)addr = d->bd_bif->bif_dlt; break; /* * Get a list of supported data link types. */ case BIOCGDLTLIST: if (d->bd_bif == NULL) error = EINVAL; else error = bpf_getdltlist(d, (struct bpf_dltlist *)addr); break; /* * Set data link type. */ case BIOCSDLT: if (d->bd_bif == NULL) error = EINVAL; else error = bpf_setdlt(d, *(u_int *)addr); break; /* * Get interface name. */ case BIOCGETIF: if (d->bd_bif == NULL) error = EINVAL; else { struct ifnet *const ifp = d->bd_bif->bif_ifp; struct ifreq *const ifr = (struct ifreq *)addr; strlcpy(ifr->ifr_name, ifp->if_xname, sizeof(ifr->ifr_name)); } 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; /* * Get packet direction flag */ case BIOCGDIRECTION: *(u_int *)addr = d->bd_direction; break; /* * Set packet direction flag */ case BIOCSDIRECTION: { u_int direction; direction = *(u_int *)addr; switch (direction) { case BPF_D_IN: case BPF_D_INOUT: case BPF_D_OUT: d->bd_direction = direction; break; default: error = EINVAL; } } break; case BIOCFEEDBACK: d->bd_feedback = *(u_int *)addr; break; case BIOCLOCK: d->bd_locked = 1; 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(struct bpf_d *d, struct bpf_program *fp, u_long cmd) { struct bpf_insn *fcode, *old; u_int wfilter, flen, size; #ifdef BPF_JITTER bpf_jit_filter *ofunc; #endif if (cmd == BIOCSETWF) { old = d->bd_wfilter; wfilter = 1; #ifdef BPF_JITTER ofunc = NULL; #endif } else { wfilter = 0; old = d->bd_rfilter; #ifdef BPF_JITTER ofunc = d->bd_bfilter; #endif } if (fp->bf_insns == NULL) { if (fp->bf_len != 0) return (EINVAL); BPFD_LOCK(d); if (wfilter) d->bd_wfilter = NULL; else { d->bd_rfilter = NULL; #ifdef BPF_JITTER d->bd_bfilter = NULL; #endif } reset_d(d); BPFD_UNLOCK(d); if (old != NULL) free((caddr_t)old, M_BPF); #ifdef BPF_JITTER if (ofunc != NULL) bpf_destroy_jit_filter(ofunc); #endif 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)) { BPFD_LOCK(d); if (wfilter) d->bd_wfilter = fcode; else { d->bd_rfilter = fcode; #ifdef BPF_JITTER d->bd_bfilter = bpf_jitter(fcode, flen); #endif } reset_d(d); BPFD_UNLOCK(d); if (old != NULL) free((caddr_t)old, M_BPF); #ifdef BPF_JITTER if (ofunc != NULL) bpf_destroy_jit_filter(ofunc); #endif 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(struct bpf_d *d, struct ifreq *ifr) { struct bpf_if *bp; struct ifnet *theywant; theywant = ifunit(ifr->ifr_name); if (theywant == NULL || theywant->if_bpf == NULL) return (ENXIO); bp = theywant->if_bpf; /* * Allocate the packet buffers if we need to. * If we're already attached to requested interface, * just flush the buffer. */ if (d->bd_sbuf == NULL) bpf_allocbufs(d); if (bp != d->bd_bif) { if (d->bd_bif) /* * Detach if attached to something else. */ bpf_detachd(d); bpf_attachd(d, bp); } BPFD_LOCK(d); reset_d(d); BPFD_UNLOCK(d); return (0); } /* * 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. */ static int bpfpoll(struct cdev *dev, int events, struct thread *td) { struct bpf_d *d; int revents; d = dev->si_drv1; if (d->bd_bif == NULL) return (ENXIO); /* * Refresh PID associated with this descriptor. */ revents = events & (POLLOUT | POLLWRNORM); BPFD_LOCK(d); d->bd_pid = td->td_proc->p_pid; if (events & (POLLIN | POLLRDNORM)) { if (bpf_ready(d)) revents |= events & (POLLIN | POLLRDNORM); else { selrecord(td, &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; } } } BPFD_UNLOCK(d); return (revents); } /* * Support for kevent() system call. Register EVFILT_READ filters and * reject all others. */ int bpfkqfilter(struct cdev *dev, struct knote *kn) { struct bpf_d *d = (struct bpf_d *)dev->si_drv1; if (kn->kn_filter != EVFILT_READ) return (1); /* * Refresh PID associated with this descriptor. */ BPFD_LOCK(d); d->bd_pid = curthread->td_proc->p_pid; kn->kn_fop = &bpfread_filtops; kn->kn_hook = d; knlist_add(&d->bd_sel.si_note, kn, 1); BPFD_UNLOCK(d); return (0); } static void filt_bpfdetach(struct knote *kn) { struct bpf_d *d = (struct bpf_d *)kn->kn_hook; knlist_remove(&d->bd_sel.si_note, kn, 0); } static int filt_bpfread(struct knote *kn, long hint) { struct bpf_d *d = (struct bpf_d *)kn->kn_hook; int ready; BPFD_LOCK_ASSERT(d); ready = bpf_ready(d); if (ready) { kn->kn_data = d->bd_slen; if (d->bd_hbuf) kn->kn_data += d->bd_hlen; } else 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; } return (ready); } /* * 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(struct bpf_if *bp, u_char *pkt, u_int pktlen) { struct bpf_d *d; u_int slen; int gottime; struct timeval tv; gottime = 0; BPFIF_LOCK(bp); LIST_FOREACH(d, &bp->bif_dlist, bd_next) { BPFD_LOCK(d); ++d->bd_rcount; #ifdef BPF_JITTER if (bpf_jitter_enable != 0 && d->bd_bfilter != NULL) slen = (*(d->bd_bfilter->func))(pkt, pktlen, pktlen); else #endif slen = bpf_filter(d->bd_rfilter, pkt, pktlen, pktlen); if (slen != 0) { d->bd_fcount++; if (!gottime) { microtime(&tv); gottime = 1; } #ifdef MAC if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) #endif catchpacket(d, pkt, pktlen, slen, bcopy, &tv); } BPFD_UNLOCK(d); } BPFIF_UNLOCK(bp); } /* * 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(const void *src_arg, void *dst_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_mcopy"); count = min(m->m_len, len); bcopy(mtod(m, void *), dst, count); m = m->m_next; dst += count; len -= count; } } #define BPF_CHECK_DIRECTION(d, m) \ if (((d)->bd_direction == BPF_D_IN && (m)->m_pkthdr.rcvif == NULL) || \ ((d)->bd_direction == BPF_D_OUT && (m)->m_pkthdr.rcvif != NULL)) /* * Incoming linkage from device drivers, when packet is in an mbuf chain. */ void bpf_mtap(struct bpf_if *bp, struct mbuf *m) { struct bpf_d *d; u_int pktlen, slen; int gottime; struct timeval tv; if (m->m_flags & M_SKIP_BPF) { m->m_flags &= ~M_SKIP_BPF; return; } gottime = 0; pktlen = m_length(m, NULL); BPFIF_LOCK(bp); LIST_FOREACH(d, &bp->bif_dlist, bd_next) { BPF_CHECK_DIRECTION(d, m) continue; BPFD_LOCK(d); ++d->bd_rcount; #ifdef BPF_JITTER /* XXX We cannot handle multiple mbufs. */ if (bpf_jitter_enable != 0 && d->bd_bfilter != NULL && m->m_next == NULL) slen = (*(d->bd_bfilter->func))(mtod(m, u_char *), pktlen, pktlen); else #endif slen = bpf_filter(d->bd_rfilter, (u_char *)m, pktlen, 0); if (slen != 0) { d->bd_fcount++; if (!gottime) { microtime(&tv); gottime = 1; } #ifdef MAC if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) #endif catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy, &tv); } BPFD_UNLOCK(d); } BPFIF_UNLOCK(bp); } /* * Incoming linkage from device drivers, when packet is in * an mbuf chain and to be prepended by a contiguous header. */ void bpf_mtap2(struct bpf_if *bp, void *data, u_int dlen, struct mbuf *m) { struct mbuf mb; struct bpf_d *d; u_int pktlen, slen; int gottime; struct timeval tv; if (m->m_flags & M_SKIP_BPF) { m->m_flags &= ~M_SKIP_BPF; return; } gottime = 0; pktlen = m_length(m, NULL); /* * 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. */ mb.m_next = m; mb.m_data = data; mb.m_len = dlen; pktlen += dlen; BPFIF_LOCK(bp); LIST_FOREACH(d, &bp->bif_dlist, bd_next) { BPF_CHECK_DIRECTION(d, m) continue; BPFD_LOCK(d); ++d->bd_rcount; slen = bpf_filter(d->bd_rfilter, (u_char *)&mb, pktlen, 0); if (slen != 0) { d->bd_fcount++; if (!gottime) { microtime(&tv); gottime = 1; } #ifdef MAC if (mac_bpfdesc_check_receive(d, bp->bif_ifp) == 0) #endif catchpacket(d, (u_char *)&mb, pktlen, slen, bpf_mcopy, &tv); } BPFD_UNLOCK(d); } BPFIF_UNLOCK(bp); } #undef BPF_CHECK_DIRECTION /* * Move the packet data from interface memory (pkt) into the * store buffer. "cpfn" 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(struct bpf_d *d, u_char *pkt, u_int pktlen, u_int snaplen, void (*cpfn)(const void *, void *, size_t), struct timeval *tv) { struct bpf_hdr *hp; int totlen, curlen; int hdrlen = d->bd_bif->bif_hdrlen; int do_wakeup = 0; BPFD_LOCK_ASSERT(d); /* * 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 == NULL) { /* * We haven't completed the previous read yet, * so drop the packet. */ ++d->bd_dcount; 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 *)(d->bd_sbuf + curlen); hp->bh_tstamp = *tv; 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; if (do_wakeup) bpf_wakeup(d); } /* * Initialize all nonzero fields of a descriptor. */ static void bpf_allocbufs(struct bpf_d *d) { KASSERT(d->bd_fbuf == NULL, ("bpf_allocbufs: bd_fbuf != NULL")); KASSERT(d->bd_sbuf == NULL, ("bpf_allocbufs: bd_sbuf != NULL")); KASSERT(d->bd_hbuf == NULL, ("bpf_allocbufs: bd_hbuf != NULL")); d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_BPF, M_WAITOK); d->bd_slen = 0; d->bd_hlen = 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 != NULL) { free(d->bd_sbuf, M_BPF); if (d->bd_hbuf != NULL) free(d->bd_hbuf, M_BPF); if (d->bd_fbuf != NULL) free(d->bd_fbuf, M_BPF); } if (d->bd_rfilter) { free((caddr_t)d->bd_rfilter, M_BPF); #ifdef BPF_JITTER bpf_destroy_jit_filter(d->bd_bfilter); #endif } if (d->bd_wfilter) free((caddr_t)d->bd_wfilter, M_BPF); mtx_destroy(&d->bd_mtx); } /* * Attach an interface to bpf. dlt is the link layer type; hdrlen is the * fixed size of the link header (variable length headers not yet supported). */ void bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) { bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); } /* * Attach an interface to bpf. ifp is a pointer to the structure * defining the interface to be attached, dlt is the link layer type, * and hdrlen is the fixed size of the link header (variable length * headers are not yet supporrted). */ void bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) { struct bpf_if *bp; bp = malloc(sizeof(*bp), M_BPF, M_NOWAIT | M_ZERO); if (bp == NULL) panic("bpfattach"); LIST_INIT(&bp->bif_dlist); bp->bif_ifp = ifp; bp->bif_dlt = dlt; mtx_init(&bp->bif_mtx, "bpf interface lock", NULL, MTX_DEF); KASSERT(*driverp == NULL, ("bpfattach2: driverp already initialized")); *driverp = bp; mtx_lock(&bpf_mtx); LIST_INSERT_HEAD(&bpf_iflist, bp, bif_next); mtx_unlock(&bpf_mtx); /* * 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) if_printf(ifp, "bpf attached\n"); } /* * Detach bpf from an interface. This involves detaching each descriptor * associated with the interface, and leaving bd_bif NULL. Notify each * descriptor as it's detached so that any sleepers wake up and get * ENXIO. */ void bpfdetach(struct ifnet *ifp) { struct bpf_if *bp; struct bpf_d *d; /* Locate BPF interface information */ mtx_lock(&bpf_mtx); LIST_FOREACH(bp, &bpf_iflist, bif_next) { if (ifp == bp->bif_ifp) break; } /* Interface wasn't attached */ if ((bp == NULL) || (bp->bif_ifp == NULL)) { mtx_unlock(&bpf_mtx); printf("bpfdetach: %s was not attached\n", ifp->if_xname); return; } LIST_REMOVE(bp, bif_next); mtx_unlock(&bpf_mtx); while ((d = LIST_FIRST(&bp->bif_dlist)) != NULL) { bpf_detachd(d); BPFD_LOCK(d); bpf_wakeup(d); BPFD_UNLOCK(d); } mtx_destroy(&bp->bif_mtx); free(bp, M_BPF); } /* * 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; mtx_lock(&bpf_mtx); LIST_FOREACH(bp, &bpf_iflist, bif_next) { if (bp->bif_ifp != ifp) continue; if (bfl->bfl_list != NULL) { if (n >= bfl->bfl_len) { mtx_unlock(&bpf_mtx); return (ENOMEM); } error = copyout(&bp->bif_dlt, bfl->bfl_list + n, sizeof(u_int)); } n++; } mtx_unlock(&bpf_mtx); 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 error, opromisc; struct ifnet *ifp; struct bpf_if *bp; if (d->bd_bif->bif_dlt == dlt) return (0); ifp = d->bd_bif->bif_ifp; mtx_lock(&bpf_mtx); LIST_FOREACH(bp, &bpf_iflist, bif_next) { if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) break; } mtx_unlock(&bpf_mtx); if (bp != NULL) { opromisc = d->bd_promisc; bpf_detachd(d); bpf_attachd(d, bp); BPFD_LOCK(d); reset_d(d); BPFD_UNLOCK(d); if (opromisc) { error = ifpromisc(bp->bif_ifp, 1); if (error) if_printf(bp->bif_ifp, "bpf_setdlt: ifpromisc failed (%d)\n", error); else d->bd_promisc = 1; } } return (bp == NULL ? EINVAL : 0); } static void bpf_clone(void *arg, struct ucred *cred, char *name, int namelen, struct cdev **dev) { int u; if (*dev != NULL) return; if (dev_stdclone(name, NULL, "bpf", &u) != 1) return; *dev = make_dev(&bpf_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, "bpf%d", u); dev_ref(*dev); (*dev)->si_flags |= SI_CHEAPCLONE; return; } static void bpf_drvinit(void *unused) { mtx_init(&bpf_mtx, "bpf global lock", NULL, MTX_DEF); LIST_INIT(&bpf_iflist); EVENTHANDLER_REGISTER(dev_clone, bpf_clone, 0, 1000); } static void bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd) { bzero(d, sizeof(*d)); BPFD_LOCK_ASSERT(bd); d->bd_immediate = bd->bd_immediate; d->bd_promisc = bd->bd_promisc; d->bd_hdrcmplt = bd->bd_hdrcmplt; d->bd_direction = bd->bd_direction; d->bd_feedback = bd->bd_feedback; d->bd_async = bd->bd_async; d->bd_rcount = bd->bd_rcount; d->bd_dcount = bd->bd_dcount; d->bd_fcount = bd->bd_fcount; d->bd_sig = bd->bd_sig; d->bd_slen = bd->bd_slen; d->bd_hlen = bd->bd_hlen; d->bd_bufsize = bd->bd_bufsize; d->bd_pid = bd->bd_pid; strlcpy(d->bd_ifname, bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ); d->bd_locked = bd->bd_locked; } static int bpf_stats_sysctl(SYSCTL_HANDLER_ARGS) { struct xbpf_d *xbdbuf, *xbd; int index, error; struct bpf_if *bp; struct bpf_d *bd; /* * XXX This is not technically correct. It is possible for non * privileged users to open bpf devices. It would make sense * if the users who opened the devices were able to retrieve * the statistics for them, too. */ error = priv_check(req->td, PRIV_NET_BPF); if (error) return (error); if (req->oldptr == NULL) return (SYSCTL_OUT(req, 0, bpf_bpfd_cnt * sizeof(*xbd))); if (bpf_bpfd_cnt == 0) return (SYSCTL_OUT(req, 0, 0)); xbdbuf = malloc(req->oldlen, M_BPF, M_WAITOK); mtx_lock(&bpf_mtx); if (req->oldlen < (bpf_bpfd_cnt * sizeof(*xbd))) { mtx_unlock(&bpf_mtx); free(xbdbuf, M_BPF); return (ENOMEM); } index = 0; LIST_FOREACH(bp, &bpf_iflist, bif_next) { BPFIF_LOCK(bp); LIST_FOREACH(bd, &bp->bif_dlist, bd_next) { xbd = &xbdbuf[index++]; BPFD_LOCK(bd); bpfstats_fill_xbpf(xbd, bd); BPFD_UNLOCK(bd); } BPFIF_UNLOCK(bp); } mtx_unlock(&bpf_mtx); error = SYSCTL_OUT(req, xbdbuf, index * sizeof(*xbd)); free(xbdbuf, M_BPF); return (error); } SYSINIT(bpfdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,bpf_drvinit,NULL) #else /* !DEV_BPF && !NETGRAPH_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. */ static struct bpf_if bp_null; void bpf_tap(struct bpf_if *bp, u_char *pkt, u_int pktlen) { } void bpf_mtap(struct bpf_if *bp, struct mbuf *m) { } void bpf_mtap2(struct bpf_if *bp, void *d, u_int l, struct mbuf *m) { } void bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen) { bpfattach2(ifp, dlt, hdrlen, &ifp->if_bpf); } void bpfattach2(struct ifnet *ifp, u_int dlt, u_int hdrlen, struct bpf_if **driverp) { *driverp = &bp_null; } void bpfdetach(struct ifnet *ifp) { } u_int bpf_filter(const struct bpf_insn *pc, u_char *p, u_int wirelen, u_int buflen) { return -1; /* "no filter" behaviour */ } int bpf_validate(const struct bpf_insn *f, int len) { return 0; /* false */ } #endif /* !DEV_BPF && !NETGRAPH_BPF */