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gems-kernel/source/THIRDPARTY/xnu/bsd/net/bpf.c
Sam Sneed f5727805f2 add darwin/xnu functionality
2024-06-03 11:29:39 -05:00

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/*
* Copyright (c) 2000-2022 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* 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: src/sys/net/bpf.c,v 1.59.2.5 2001/01/05 04:49:09 jdp Exp $
*/
/*
* NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
* support for mandatory and extensible security protections. This notice
* is included in support of clause 2.2 (b) of the Apple Public License,
* Version 2.0.
*/
#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>
#include <sys/uio_internal.h>
#include <sys/file_internal.h>
#include <sys/event.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/vnode.h>
#include <net/if.h>
#include <net/bpf.h>
#include <net/bpfdesc.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <netinet/tcp_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/if_ether.h>
#include <netinet/isakmp.h>
#include <netinet6/esp.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <net/firewire.h>
#include <miscfs/devfs/devfs.h>
#include <net/dlil.h>
#include <net/pktap.h>
#include <net/sockaddr_utils.h>
#include <kern/assert.h>
#include <kern/locks.h>
#include <kern/thread_call.h>
#include <libkern/section_keywords.h>
#include <os/log.h>
#include <IOKit/IOBSD.h>
extern int tvtohz(struct timeval *);
extern char *proc_name_address(void *p);
#define BPF_BUFSIZE 4096
#define PRINET 26 /* interruptible */
#define ISAKMP_HDR_SIZE (sizeof(struct isakmp) + sizeof(struct isakmp_gen))
#define ESP_HDR_SIZE sizeof(struct newesp)
#define BPF_WRITE_LEEWAY 18 /* space for link layer header */
#define BPF_WRITE_MAX 0x1000000 /* 16 MB arbitrary value */
typedef void (*pktcopyfunc_t)(const void *, void *, size_t);
/*
* The default read buffer size is patchable.
*/
static unsigned int bpf_bufsize = BPF_BUFSIZE;
SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW | CTLFLAG_LOCKED,
&bpf_bufsize, 0, "");
__private_extern__ unsigned int bpf_maxbufsize = BPF_MAXBUFSIZE;
static int sysctl_bpf_maxbufsize SYSCTL_HANDLER_ARGS;
SYSCTL_PROC(_debug, OID_AUTO, bpf_maxbufsize, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED,
&bpf_maxbufsize, 0,
sysctl_bpf_maxbufsize, "I", "Default BPF max buffer size");
extern const int copysize_limit_panic;
#define BPF_BUFSIZE_CAP (copysize_limit_panic >> 1)
static int sysctl_bpf_bufsize_cap SYSCTL_HANDLER_ARGS;
SYSCTL_PROC(_debug, OID_AUTO, bpf_bufsize_cap, CTLTYPE_INT | CTLFLAG_RD | CTLFLAG_LOCKED,
0, 0,
sysctl_bpf_bufsize_cap, "I", "Upper limit on BPF max buffer size");
#define BPF_MAX_DEVICES 256
static unsigned int bpf_maxdevices = BPF_MAX_DEVICES;
SYSCTL_UINT(_debug, OID_AUTO, bpf_maxdevices, CTLFLAG_RD | CTLFLAG_LOCKED,
&bpf_maxdevices, 0, "");
/*
* bpf_wantpktap controls the defaul visibility of DLT_PKTAP
* For OS X is off by default so process need to use the ioctl BPF_WANT_PKTAP
* explicitly to be able to use DLT_PKTAP.
*/
#if !XNU_TARGET_OS_OSX
static unsigned int bpf_wantpktap = 1;
#else /* XNU_TARGET_OS_OSX */
static unsigned int bpf_wantpktap = 0;
#endif /* XNU_TARGET_OS_OSX */
SYSCTL_UINT(_debug, OID_AUTO, bpf_wantpktap, CTLFLAG_RW | CTLFLAG_LOCKED,
&bpf_wantpktap, 0, "");
static int bpf_debug = 0;
SYSCTL_INT(_debug, OID_AUTO, bpf_debug, CTLFLAG_RW | CTLFLAG_LOCKED,
&bpf_debug, 0, "");
static unsigned long bpf_trunc_overflow = 0;
SYSCTL_ULONG(_debug, OID_AUTO, bpf_trunc_overflow, CTLFLAG_RD | CTLFLAG_LOCKED,
&bpf_trunc_overflow, "");
static int bpf_hdr_comp_enable = 1;
SYSCTL_INT(_debug, OID_AUTO, bpf_hdr_comp_enable, CTLFLAG_RW | CTLFLAG_LOCKED,
&bpf_hdr_comp_enable, 1, "");
static int sysctl_bpf_stats SYSCTL_HANDLER_ARGS;
SYSCTL_PROC(_debug, OID_AUTO, bpf_stats, CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED,
0, 0,
sysctl_bpf_stats, "S", "BPF statistics");
/*
* bpf_iflist is the list of interfaces; each corresponds to an ifnet
* bpf_dtab holds pointer to the descriptors, indexed by minor device #
*/
static struct bpf_if *bpf_iflist;
/*
* BSD now stores the bpf_d in the dev_t which is a struct
* on their system. Our dev_t is an int, so we still store
* the bpf_d in a separate table indexed by minor device #.
*
* The value stored in bpf_dtab[n] represent three states:
* NULL: device not opened
* BPF_DEV_RESERVED: device opening or closing
* other: device <n> opened with pointer to storage
*/
#define BPF_DEV_RESERVED ((struct bpf_d *)(uintptr_t)1)
static struct bpf_d **bpf_dtab = NULL;
static unsigned int bpf_dtab_size = 0;
static unsigned int nbpfilter = 0;
static unsigned bpf_bpfd_cnt = 0;
static LCK_GRP_DECLARE(bpf_mlock_grp, "bpf");
static LCK_MTX_DECLARE(bpf_mlock_data, &bpf_mlock_grp);
static lck_mtx_t *const bpf_mlock = &bpf_mlock_data;
static int bpf_allocbufs(struct bpf_d *);
static errno_t bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
static int bpf_detachd(struct bpf_d *d);
static void bpf_freed(struct bpf_d *);
static int bpf_setif(struct bpf_d *, ifnet_t ifp, bool, bool, bool);
static void bpf_timed_out(void *, void *);
static void bpf_wakeup(struct bpf_d *);
static uint32_t get_pkt_trunc_len(struct bpf_packet *);
static void catchpacket(struct bpf_d *, struct bpf_packet *, u_int, int);
static void reset_d(struct bpf_d *);
static int bpf_setf(struct bpf_d *, u_int, user_addr_t, u_long);
static int bpf_getdltlist(struct bpf_d *, caddr_t, struct proc *);
static int bpf_setdlt(struct bpf_d *, u_int);
static int bpf_set_traffic_class(struct bpf_d *, int);
static void bpf_set_packet_service_class(struct mbuf *, int);
static void bpf_acquire_d(struct bpf_d *);
static void bpf_release_d(struct bpf_d *);
static int bpf_devsw_installed;
void bpf_init(void *unused);
static int bpf_tap_callback(struct ifnet *ifp, struct mbuf *m);
/*
* Darwin differs from BSD here, the following are static
* on BSD and not static on Darwin.
*/
d_open_t bpfopen;
d_close_t bpfclose;
d_read_t bpfread;
d_write_t bpfwrite;
ioctl_fcn_t bpfioctl;
select_fcn_t bpfselect;
/* Darwin's cdevsw struct differs slightly from BSDs */
#define CDEV_MAJOR 23
static const struct cdevsw bpf_cdevsw = {
.d_open = bpfopen,
.d_close = bpfclose,
.d_read = bpfread,
.d_write = bpfwrite,
.d_ioctl = bpfioctl,
.d_stop = eno_stop,
.d_reset = eno_reset,
.d_ttys = NULL,
.d_select = bpfselect,
.d_mmap = eno_mmap,
.d_strategy = eno_strat,
.d_reserved_1 = eno_getc,
.d_reserved_2 = eno_putc,
.d_type = 0
};
#define SOCKADDR_HDR_LEN offsetof(struct sockaddr, sa_data)
static int
bpf_copy_uio_to_mbuf_packet(struct uio *auio, int bytes_to_copy, struct mbuf *top)
{
int error = 0;
for (struct mbuf *m = top; m != NULL; m = m->m_next) {
int mlen;
if (m->m_flags & M_EXT) {
mlen = m->m_ext.ext_size - (int)M_LEADINGSPACE(m);
} else if (m->m_flags & M_PKTHDR) {
mlen = MHLEN - (int)M_LEADINGSPACE(m);
} else {
mlen = MLEN - (int)M_LEADINGSPACE(m);
}
int copy_len = imin((int)mlen, bytes_to_copy);
error = uiomove(mtod(m, caddr_t), (int)copy_len, auio);
if (error != 0) {
os_log(OS_LOG_DEFAULT, "bpf_copy_uio_to_mbuf_packet: len %d error %d",
copy_len, error);
goto done;
}
m->m_len = copy_len;
top->m_pkthdr.len += copy_len;
if (bytes_to_copy > copy_len) {
bytes_to_copy -= copy_len;
} else {
break;
}
}
done:
return error;
}
static int
bpf_movein(struct uio *uio, int copy_len, struct bpf_d *d, struct mbuf **mp,
struct sockaddr *sockp)
{
struct mbuf *m = NULL;
int error;
int len;
uint8_t sa_family;
int hlen = 0;
struct ifnet *ifp = d->bd_bif->bif_ifp;
int linktype = (int)d->bd_bif->bif_dlt;
switch (linktype) {
#if SLIP
case DLT_SLIP:
sa_family = AF_INET;
hlen = 0;
break;
#endif /* SLIP */
case DLT_EN10MB:
sa_family = AF_UNSPEC;
/* XXX Would MAXLINKHDR be better? */
hlen = sizeof(struct ether_header);
break;
#if FDDI
case DLT_FDDI:
#if defined(__FreeBSD__) || defined(__bsdi__)
sa_family = AF_IMPLINK;
hlen = 0;
#else
sa_family = AF_UNSPEC;
/* XXX 4(FORMAC)+6(dst)+6(src)+3(LLC)+5(SNAP) */
hlen = 24;
#endif
break;
#endif /* FDDI */
case DLT_RAW:
case DLT_NULL:
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.
*/
sa_family = AF_UNSPEC;
hlen = 12; /* XXX 4(ATM_PH) + 3(LLC) + 5(SNAP) */
break;
#endif
case DLT_PPP:
sa_family = AF_UNSPEC;
hlen = 4; /* This should match PPP_HDRLEN */
break;
case DLT_APPLE_IP_OVER_IEEE1394:
sa_family = AF_UNSPEC;
hlen = sizeof(struct firewire_header);
break;
case DLT_IEEE802_11: /* IEEE 802.11 wireless */
sa_family = AF_IEEE80211;
hlen = 0;
break;
case DLT_IEEE802_11_RADIO:
sa_family = AF_IEEE80211;
hlen = 0;
break;
default:
return EIO;
}
if (sockp) {
/*
* 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.
*/
if ((hlen + SOCKADDR_HDR_LEN) > sockp->sa_len) {
return EIO;
}
sockp->sa_family = sa_family;
} else {
/*
* We're directly sending the packet data supplied by
* the user; we don't need to make room for the link
* header, and don't need the header length value any
* more, so set it to 0.
*/
hlen = 0;
}
len = (int)uio_resid(uio);
if (len < copy_len) {
os_log(OS_LOG_DEFAULT, "bpfwrite: len %d if %s less than copy_len %d",
(unsigned)len, ifp->if_xname, copy_len);
return EMSGSIZE;
}
len = copy_len;
if (len < hlen || (unsigned)len > BPF_WRITE_MAX) {
os_log(OS_LOG_DEFAULT, "bpfwrite: bad len %d if %s",
(unsigned)len, ifp->if_xname);
return EMSGSIZE;
}
if (d->bd_write_size_max != 0) {
if ((len - hlen) > (d->bd_write_size_max + BPF_WRITE_LEEWAY)) {
os_log(OS_LOG_DEFAULT, "bpfwrite: len %u - hlen %u too big if %s write_size_max %u",
(unsigned)len, (unsigned)hlen, ifp->if_xname, d->bd_write_size_max);
}
} else if ((len - hlen) > (ifp->if_mtu + BPF_WRITE_LEEWAY)) {
os_log(OS_LOG_DEFAULT, "bpfwrite: len %u - hlen %u too big if %s mtu %u",
(unsigned)len, (unsigned)hlen, ifp->if_xname, ifp->if_mtu);
return EMSGSIZE;
}
/* drop lock while allocating mbuf and copying data */
lck_mtx_unlock(bpf_mlock);
error = mbuf_allocpacket(MBUF_WAITOK, len, NULL, &m);
if (error != 0) {
os_log(OS_LOG_DEFAULT,
"bpfwrite mbuf_allocpacket len %d error %d", len, error);
goto bad;
}
/*
* Make room for link header -- the packet length is 0 at this stage
*/
if (hlen != 0) {
m->m_data += hlen; /* leading space */
error = uiomove((caddr_t)sockp->sa_data, hlen, uio);
if (error) {
os_log(OS_LOG_DEFAULT,
"bpfwrite uiomove hlen %d error %d", hlen, error);
goto bad;
}
len -= hlen;
}
/*
* bpf_copy_uio_to_mbuf_packet() does set the length of each mbuf and adds it to
* the total packet length
*/
error = bpf_copy_uio_to_mbuf_packet(uio, len, m);
if (error != 0) {
os_log(OS_LOG_DEFAULT,
"bpfwrite bpf_copy_uio_to_mbuf_packet error %d", error);
goto bad;
}
/* Check for multicast destination */
switch (linktype) {
case DLT_EN10MB: {
struct ether_header *eh;
eh = mtod(m, struct ether_header *);
if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
if (_ether_cmp(etherbroadcastaddr,
eh->ether_dhost) == 0) {
m->m_flags |= M_BCAST;
} else {
m->m_flags |= M_MCAST;
}
}
break;
}
}
*mp = m;
lck_mtx_lock(bpf_mlock);
return 0;
bad:
if (m != NULL) {
m_freem(m);
}
lck_mtx_lock(bpf_mlock);
return error;
}
static int
bpf_movein_batch(struct uio *uio, struct bpf_d *d, struct mbuf **mp,
struct sockaddr *sockp)
{
int error = 0;
user_ssize_t resid;
int count = 0;
struct mbuf *last = NULL;
*mp = NULL;
while ((resid = uio_resid(uio)) >= sizeof(struct bpf_hdr)) {
struct bpf_hdr bpfhdr = {};
int bpf_hdr_min_len = offsetof(struct bpf_hdr, bh_hdrlen) + sizeof(bpfhdr.bh_hdrlen);
int padding_len;
error = uiomove((caddr_t)&bpfhdr, bpf_hdr_min_len, uio);
if (error != 0) {
os_log(OS_LOG_DEFAULT, "bpf_movein_batch uiomove error %d", error);
break;
}
/*
* Buffer validation:
* - ignore bh_tstamp
* - bh_hdrlen must fit
* - bh_caplen and bh_datalen must be equal
*/
if (bpfhdr.bh_hdrlen < bpf_hdr_min_len) {
error = EINVAL;
os_log(OS_LOG_DEFAULT, "bpf_movein_batch bh_hdrlen %u too small",
bpfhdr.bh_hdrlen);
break;
}
if (bpfhdr.bh_caplen != bpfhdr.bh_datalen) {
error = EINVAL;
os_log(OS_LOG_DEFAULT, "bpf_movein_batch bh_caplen %u != bh_datalen %u",
bpfhdr.bh_caplen, bpfhdr.bh_datalen);
break;
}
if (bpfhdr.bh_hdrlen > resid) {
error = EINVAL;
os_log(OS_LOG_DEFAULT, "bpf_movein_batch bh_hdrlen %u too large",
bpfhdr.bh_hdrlen);
break;
}
/*
* Ignore additional bytes in the header
*/
padding_len = bpfhdr.bh_hdrlen - bpf_hdr_min_len;
if (padding_len > 0) {
uio_update(uio, padding_len);
}
/* skip empty packets */
if (bpfhdr.bh_caplen > 0) {
struct mbuf *m;
/*
* For time being assume all packets have same destination
*/
error = bpf_movein(uio, bpfhdr.bh_caplen, d, &m, sockp);
if (error != 0) {
os_log(OS_LOG_DEFAULT, "bpf_movein_batch bpf_movein error %d",
error);
break;
}
count += 1;
if (last == NULL) {
*mp = m;
} else {
last->m_nextpkt = m;
}
last = m;
}
/*
* Each BPF packet is padded for alignment
*/
padding_len = BPF_WORDALIGN(bpfhdr.bh_hdrlen + bpfhdr.bh_caplen) - (bpfhdr.bh_hdrlen + bpfhdr.bh_caplen);
if (padding_len > 0) {
uio_update(uio, padding_len);
}
}
if (error != 0) {
if (*mp != NULL) {
m_freem_list(*mp);
*mp = NULL;
}
}
return error;
}
/*
* The dynamic addition of a new device node must block all processes that
* are opening the last device so that no process will get an unexpected
* ENOENT
*/
static void
bpf_make_dev_t(int maj)
{
static int bpf_growing = 0;
unsigned int cur_size = nbpfilter, i;
if (nbpfilter >= BPF_MAX_DEVICES) {
return;
}
while (bpf_growing) {
/* Wait until new device has been created */
(void) tsleep((caddr_t)&bpf_growing, PZERO, "bpf_growing", 0);
}
if (nbpfilter > cur_size) {
/* other thread grew it already */
return;
}
bpf_growing = 1;
/* need to grow bpf_dtab first */
if (nbpfilter == bpf_dtab_size) {
unsigned int new_dtab_size;
struct bpf_d **new_dtab = NULL;
new_dtab_size = bpf_dtab_size + NBPFILTER;
new_dtab = krealloc_type(struct bpf_d *,
bpf_dtab_size, new_dtab_size, bpf_dtab, Z_WAITOK | Z_ZERO);
if (new_dtab == 0) {
os_log_error(OS_LOG_DEFAULT, "bpf_make_dev_t: malloc bpf_dtab failed");
goto done;
}
bpf_dtab = new_dtab;
bpf_dtab_size = new_dtab_size;
}
i = nbpfilter++;
(void) devfs_make_node(makedev(maj, i),
DEVFS_CHAR, UID_ROOT, GID_WHEEL, 0600,
"bpf%d", i);
done:
bpf_growing = 0;
wakeup((caddr_t)&bpf_growing);
}
/*
* Attach file to the bpf interface, i.e. make d listen on bp.
*/
static errno_t
bpf_attachd(struct bpf_d *d, struct bpf_if *bp)
{
int first = bp->bif_dlist == NULL;
int error = 0;
/*
* 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;
bpf_bpfd_cnt++;
/*
* Take a reference on the device even if an error is returned
* because we keep the device in the interface's list of listeners
*/
bpf_acquire_d(d);
if (first) {
/* Find the default bpf entry for this ifp */
if (bp->bif_ifp->if_bpf == NULL) {
struct bpf_if *tmp, *primary = NULL;
for (tmp = bpf_iflist; tmp; tmp = tmp->bif_next) {
if (tmp->bif_ifp == bp->bif_ifp) {
primary = tmp;
break;
}
}
bp->bif_ifp->if_bpf = primary;
}
/* Only call dlil_set_bpf_tap for primary dlt */
if (bp->bif_ifp->if_bpf == bp) {
dlil_set_bpf_tap(bp->bif_ifp, BPF_TAP_INPUT_OUTPUT,
bpf_tap_callback);
}
if (bp->bif_tap != NULL) {
error = bp->bif_tap(bp->bif_ifp, bp->bif_dlt,
BPF_TAP_INPUT_OUTPUT);
}
}
/*
* Reset the detach flags in case we previously detached an interface
*/
d->bd_flags &= ~(BPF_DETACHING | BPF_DETACHED);
if (bp->bif_dlt == DLT_PKTAP) {
d->bd_flags |= BPF_FINALIZE_PKTAP;
} else {
d->bd_flags &= ~BPF_FINALIZE_PKTAP;
}
return error;
}
/*
* Detach a file from its interface.
*
* Return 1 if was closed by some thread, 0 otherwise
*/
static int
bpf_detachd(struct bpf_d *d)
{
struct bpf_d **p;
struct bpf_if *bp;
struct ifnet *ifp;
uint32_t dlt;
bpf_tap_func disable_tap;
uint8_t bd_promisc;
int bpf_closed = d->bd_flags & BPF_CLOSING;
/*
* Some other thread already detached
*/
if ((d->bd_flags & (BPF_DETACHED | BPF_DETACHING)) != 0) {
goto done;
}
/*
* This thread is doing the detach
*/
d->bd_flags |= BPF_DETACHING;
ifp = d->bd_bif->bif_ifp;
bp = d->bd_bif;
/* 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;
bpf_bpfd_cnt--;
disable_tap = NULL;
if (bp->bif_dlist == 0) {
/*
* Let the driver know that there are no more listeners.
*/
/* Only call dlil_set_bpf_tap for primary dlt */
if (bp->bif_ifp->if_bpf == bp) {
dlil_set_bpf_tap(ifp, BPF_TAP_DISABLE, NULL);
}
disable_tap = bp->bif_tap;
if (disable_tap) {
dlt = bp->bif_dlt;
}
for (bp = bpf_iflist; bp; bp = bp->bif_next) {
if (bp->bif_ifp == ifp && bp->bif_dlist != 0) {
break;
}
}
if (bp == NULL) {
ifp->if_bpf = NULL;
}
}
d->bd_bif = NULL;
/*
* Check if this descriptor had requested promiscuous mode.
* If so, turn it off.
*/
bd_promisc = d->bd_promisc;
d->bd_promisc = 0;
lck_mtx_unlock(bpf_mlock);
if (bd_promisc) {
if (ifnet_set_promiscuous(ifp, 0)) {
/*
* Something is really wrong if we were able to put
* the driver into promiscuous mode, but can't
* take it out.
* Most likely the network interface is gone.
*/
os_log_error(OS_LOG_DEFAULT,
"%s: bpf%d ifnet_set_promiscuous %s failed",
__func__, d->bd_dev_minor, if_name(ifp));
}
}
if (disable_tap) {
disable_tap(ifp, dlt, BPF_TAP_DISABLE);
}
lck_mtx_lock(bpf_mlock);
/*
* Wake up other thread that are waiting for this thread to finish
* detaching
*/
d->bd_flags &= ~BPF_DETACHING;
d->bd_flags |= BPF_DETACHED;
/* Refresh the local variable as d could have been modified */
bpf_closed = d->bd_flags & BPF_CLOSING;
os_log(OS_LOG_DEFAULT, "bpf%d%s detached from %s fcount %llu dcount %llu",
d->bd_dev_minor, bpf_closed ? " closed and" : "", if_name(ifp),
d->bd_fcount, d->bd_dcount);
/*
* Note that We've kept the reference because we may have dropped
* the lock when turning off promiscuous mode
*/
bpf_release_d(d);
done:
/*
* Let the caller know the bpf_d is closed
*/
if (bpf_closed) {
return 1;
} else {
return 0;
}
}
/*
* Start asynchronous timer, if necessary.
* Must be called with bpf_mlock held.
*/
static void
bpf_start_timer(struct bpf_d *d)
{
uint64_t deadline;
struct timeval tv;
if (d->bd_rtout > 0 && d->bd_state == BPF_IDLE) {
tv.tv_sec = d->bd_rtout / hz;
tv.tv_usec = (d->bd_rtout % hz) * tick;
clock_interval_to_deadline(
(uint32_t)tv.tv_sec * USEC_PER_SEC + tv.tv_usec,
NSEC_PER_USEC, &deadline);
/*
* The state is BPF_IDLE, so the timer hasn't
* been started yet, and hasn't gone off yet;
* there is no thread call scheduled, so this
* won't change the schedule.
*
* XXX - what if, by the time it gets entered,
* the deadline has already passed?
*/
thread_call_enter_delayed(d->bd_thread_call, deadline);
d->bd_state = BPF_WAITING;
}
}
/*
* Cancel asynchronous timer.
* Must be called with bpf_mlock held.
*/
static boolean_t
bpf_stop_timer(struct bpf_d *d)
{
/*
* If the timer has already gone off, this does nothing.
* Our caller is expected to set d->bd_state to BPF_IDLE,
* with the bpf_mlock, after we are called. bpf_timed_out()
* also grabs bpf_mlock, so, if the timer has gone off and
* bpf_timed_out() hasn't finished, it's waiting for the
* lock; when this thread releases the lock, it will
* find the state is BPF_IDLE, and just release the
* lock and return.
*/
return thread_call_cancel(d->bd_thread_call);
}
void
bpf_acquire_d(struct bpf_d *d)
{
void *lr_saved = __builtin_return_address(0);
LCK_MTX_ASSERT(bpf_mlock, LCK_MTX_ASSERT_OWNED);
d->bd_refcnt += 1;
d->bd_ref_lr[d->bd_next_ref_lr] = lr_saved;
d->bd_next_ref_lr = (d->bd_next_ref_lr + 1) % BPF_REF_HIST;
}
void
bpf_release_d(struct bpf_d *d)
{
void *lr_saved = __builtin_return_address(0);
LCK_MTX_ASSERT(bpf_mlock, LCK_MTX_ASSERT_OWNED);
if (d->bd_refcnt <= 0) {
panic("%s: %p refcnt <= 0", __func__, d);
}
d->bd_refcnt -= 1;
d->bd_unref_lr[d->bd_next_unref_lr] = lr_saved;
d->bd_next_unref_lr = (d->bd_next_unref_lr + 1) % BPF_REF_HIST;
if (d->bd_refcnt == 0) {
/* Assert the device is detached */
if ((d->bd_flags & BPF_DETACHED) == 0) {
panic("%s: %p BPF_DETACHED not set", __func__, d);
}
kfree_type(struct bpf_d, d);
}
}
/*
* Open ethernet device. Returns ENXIO for illegal minor device number,
* EBUSY if file is open by another process.
*/
/* ARGSUSED */
int
bpfopen(dev_t dev, int flags, __unused int fmt,
struct proc *p)
{
struct bpf_d *d;
lck_mtx_lock(bpf_mlock);
if ((unsigned int) minor(dev) >= nbpfilter) {
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
/*
* New device nodes are created on demand when opening the last one.
* The programming model is for processes to loop on the minor starting
* at 0 as long as EBUSY is returned. The loop stops when either the
* open succeeds or an error other that EBUSY is returned. That means
* that bpf_make_dev_t() must block all processes that are opening the
* last node. If not all processes are blocked, they could unexpectedly
* get ENOENT and abort their opening loop.
*/
if ((unsigned int) minor(dev) == (nbpfilter - 1)) {
bpf_make_dev_t(major(dev));
}
/*
* Each minor can be opened by only one process. If the requested
* minor is in use, return EBUSY.
*
* Important: bpfopen() and bpfclose() have to check and set the status
* of a device in the same lockin context otherwise the device may be
* leaked because the vnode use count will be unpextectly greater than 1
* when close() is called.
*/
if (bpf_dtab[minor(dev)] == NULL) {
/* Reserve while opening */
bpf_dtab[minor(dev)] = BPF_DEV_RESERVED;
} else {
lck_mtx_unlock(bpf_mlock);
return EBUSY;
}
d = kalloc_type(struct bpf_d, Z_WAITOK | Z_ZERO);
if (d == NULL) {
/* this really is a catastrophic failure */
os_log_error(OS_LOG_DEFAULT,
"bpfopen: bpf%d kalloc_type bpf_d failed", minor(dev));
bpf_dtab[minor(dev)] = NULL;
lck_mtx_unlock(bpf_mlock);
return ENOMEM;
}
/* Mark "in use" and do most initialization. */
bpf_acquire_d(d);
d->bd_bufsize = bpf_bufsize;
d->bd_sig = SIGIO;
d->bd_direction = BPF_D_INOUT;
d->bd_oflags = flags;
d->bd_state = BPF_IDLE;
d->bd_traffic_class = SO_TC_BE;
d->bd_flags |= BPF_DETACHED;
if (bpf_wantpktap) {
d->bd_flags |= BPF_WANT_PKTAP;
} else {
d->bd_flags &= ~BPF_WANT_PKTAP;
}
d->bd_thread_call = thread_call_allocate(bpf_timed_out, d);
if (d->bd_thread_call == NULL) {
os_log_error(OS_LOG_DEFAULT, "bpfopen: bpf%d malloc thread call failed",
minor(dev));
bpf_dtab[minor(dev)] = NULL;
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return ENOMEM;
}
d->bd_opened_by = p;
uuid_generate(d->bd_uuid);
d->bd_pid = proc_pid(p);
d->bd_dev_minor = minor(dev);
bpf_dtab[minor(dev)] = d; /* Mark opened */
lck_mtx_unlock(bpf_mlock);
if (bpf_debug) {
os_log(OS_LOG_DEFAULT, "bpf%u opened by %s.%u",
d->bd_dev_minor, proc_name_address(p), d->bd_pid);
}
return 0;
}
/*
* Close the descriptor by detaching it from its interface,
* deallocating its buffers, and marking it free.
*/
/* ARGSUSED */
int
bpfclose(dev_t dev, __unused int flags, __unused int fmt,
__unused struct proc *p)
{
struct bpf_d *d;
/* Take BPF lock to ensure no other thread is using the device */
lck_mtx_lock(bpf_mlock);
d = bpf_dtab[minor(dev)];
if (d == NULL || d == BPF_DEV_RESERVED) {
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
/*
* Other threads may call bpd_detachd() if we drop the bpf_mlock
*/
d->bd_flags |= BPF_CLOSING;
if (bpf_debug != 0) {
os_log(OS_LOG_DEFAULT, "%s: bpf%d",
__func__, d->bd_dev_minor);
}
bpf_dtab[minor(dev)] = BPF_DEV_RESERVED; /* Reserve while closing */
/*
* Deal with any in-progress timeouts.
*/
switch (d->bd_state) {
case BPF_IDLE:
/*
* Not waiting for a timeout, and no timeout happened.
*/
break;
case BPF_WAITING:
/*
* Waiting for a timeout.
* Cancel any timer that has yet to go off,
* and mark the state as "closing".
* Then drop the lock to allow any timers that
* *have* gone off to run to completion, and wait
* for them to finish.
*/
if (!bpf_stop_timer(d)) {
/*
* There was no pending call, so the call must
* have been in progress. Wait for the call to
* complete; we have to drop the lock while
* waiting. to let the in-progrss call complete
*/
d->bd_state = BPF_DRAINING;
while (d->bd_state == BPF_DRAINING) {
msleep((caddr_t)d, bpf_mlock, PRINET,
"bpfdraining", NULL);
}
}
d->bd_state = BPF_IDLE;
break;
case BPF_TIMED_OUT:
/*
* Timer went off, and the timeout routine finished.
*/
d->bd_state = BPF_IDLE;
break;
case BPF_DRAINING:
/*
* Another thread is blocked on a close waiting for
* a timeout to finish.
* This "shouldn't happen", as the first thread to enter
* bpfclose() will set bpf_dtab[minor(dev)] to 1, and
* all subsequent threads should see that and fail with
* ENXIO.
*/
panic("Two threads blocked in a BPF close");
break;
}
if (d->bd_bif) {
bpf_detachd(d);
}
selthreadclear(&d->bd_sel);
thread_call_free(d->bd_thread_call);
while (d->bd_hbuf_read || d->bd_hbuf_write) {
msleep((caddr_t)d, bpf_mlock, PRINET, "bpfclose", NULL);
}
if (bpf_debug) {
os_log(OS_LOG_DEFAULT,
"bpf%u closed by %s.%u dcount %llu fcount %llu ccount %llu",
d->bd_dev_minor, proc_name_address(p), d->bd_pid,
d->bd_dcount, d->bd_fcount, d->bd_bcs.bcs_count_compressed_prefix);
}
bpf_freed(d);
/* Mark free in same context as bpfopen comes to check */
bpf_dtab[minor(dev)] = NULL; /* Mark closed */
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return 0;
}
#define BPF_SLEEP bpf_sleep
static int
bpf_sleep(struct bpf_d *d, int pri, const char *wmesg, int timo)
{
u_int64_t abstime = 0;
if (timo != 0) {
clock_interval_to_deadline(timo, NSEC_PER_SEC / hz, &abstime);
}
return msleep1((caddr_t)d, bpf_mlock, pri, wmesg, abstime);
}
static void
bpf_finalize_pktap(struct bpf_hdr *hp, struct pktap_header *pktaphdr)
{
if (pktaphdr->pth_flags & PTH_FLAG_V2_HDR) {
struct pktap_v2_hdr *pktap_v2_hdr;
pktap_v2_hdr = (struct pktap_v2_hdr *)pktaphdr;
if (pktap_v2_hdr->pth_flags & PTH_FLAG_DELAY_PKTAP) {
pktap_v2_finalize_proc_info(pktap_v2_hdr);
}
} else {
if (pktaphdr->pth_flags & PTH_FLAG_DELAY_PKTAP) {
pktap_finalize_proc_info(pktaphdr);
}
if (pktaphdr->pth_flags & PTH_FLAG_TSTAMP) {
hp->bh_tstamp.tv_sec = pktaphdr->pth_tstamp.tv_sec;
hp->bh_tstamp.tv_usec = pktaphdr->pth_tstamp.tv_usec;
}
}
}
/*
* 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.
*
* Note: in head drop mode, the hold buffer can be dropped so the fist packet of the
* store buffer cannot be compressed as it otherwise would refer to deleted data
* in a dropped hold buffer that the reader process does know about
*/
#define ROTATE_BUFFERS(d) do { \
if (d->bd_hbuf_read) \
panic("rotating bpf buffers during read"); \
(d)->bd_hbuf = (d)->bd_sbuf; \
(d)->bd_hlen = (d)->bd_slen; \
(d)->bd_hcnt = (d)->bd_scnt; \
(d)->bd_sbuf = (d)->bd_fbuf; \
(d)->bd_slen = 0; \
(d)->bd_scnt = 0; \
(d)->bd_fbuf = NULL; \
if ((d)->bd_headdrop != 0) \
(d)->bd_prev_slen = 0; \
} while(false)
/*
* bpfread - read next chunk of packets from buffers
*/
int
bpfread(dev_t dev, struct uio *uio, int ioflag)
{
struct bpf_d *d;
caddr_t hbuf;
int timed_out, hbuf_len;
int error;
int flags;
lck_mtx_lock(bpf_mlock);
d = bpf_dtab[minor(dev)];
if (d == NULL || d == BPF_DEV_RESERVED ||
(d->bd_flags & BPF_CLOSING) != 0) {
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
bpf_acquire_d(d);
/*
* Restrict application to use a buffer the same size as
* as kernel buffers.
*/
if (uio_resid(uio) != d->bd_bufsize) {
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return EINVAL;
}
if (d->bd_state == BPF_WAITING) {
bpf_stop_timer(d);
}
timed_out = (d->bd_state == BPF_TIMED_OUT);
d->bd_state = BPF_IDLE;
while (d->bd_hbuf_read) {
msleep((caddr_t)d, bpf_mlock, PRINET, "bpfread", NULL);
}
if ((d->bd_flags & BPF_CLOSING) != 0) {
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
/*
* 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 || timed_out || (ioflag & IO_NDELAY)) &&
d->bd_slen != 0) {
/*
* We're in immediate mode, or are reading
* in non-blocking mode, or a timer was
* started before the read (e.g., by select()
* or poll()) and has expired and 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) {
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
if (ioflag & IO_NDELAY) {
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return EWOULDBLOCK;
}
error = BPF_SLEEP(d, PRINET | PCATCH, "bpf", d->bd_rtout);
/*
* Make sure device is still opened
*/
if ((d->bd_flags & BPF_CLOSING) != 0) {
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
while (d->bd_hbuf_read) {
msleep((caddr_t)d, bpf_mlock, PRINET, "bpf_read",
NULL);
}
if ((d->bd_flags & BPF_CLOSING) != 0) {
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
if (error == EINTR || error == ERESTART) {
if (d->bd_hbuf != NULL) {
/*
* Because we msleep, the hold buffer might
* be filled when we wake up. Avoid rotating
* in this case.
*/
break;
}
if (d->bd_slen != 0) {
/*
* Sometimes we may be interrupted often and
* the sleep above will not timeout.
* Regardless, we should rotate the buffers
* if there's any new data pending and
* return it.
*/
ROTATE_BUFFERS(d);
break;
}
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
if (error == ERESTART) {
os_log(OS_LOG_DEFAULT, "%s: bpf%d ERESTART to EINTR",
__func__, d->bd_dev_minor);
error = EINTR;
}
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) {
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return 0;
}
ROTATE_BUFFERS(d);
break;
}
}
/*
* At this point, we know we have something in the hold slot.
*/
/*
* Set the hold buffer read. So we do not
* rotate the buffers until the hold buffer
* read is complete. Also to avoid issues resulting
* from page faults during disk sleep (<rdar://problem/13436396>).
*/
d->bd_hbuf_read = true;
hbuf = d->bd_hbuf;
hbuf_len = d->bd_hlen;
flags = d->bd_flags;
d->bd_bcs.bcs_total_read += d->bd_hcnt;
lck_mtx_unlock(bpf_mlock);
/*
* Before we move data to userland, we fill out the extended
* header fields.
*/
if (flags & BPF_EXTENDED_HDR) {
char *p;
p = hbuf;
while (p < hbuf + hbuf_len) {
struct bpf_hdr_ext *ehp;
uint32_t flowid;
struct so_procinfo soprocinfo;
int found = 0;
ehp = (struct bpf_hdr_ext *)(void *)p;
if ((flowid = ehp->bh_flowid) != 0) {
if (ehp->bh_flags & BPF_HDR_EXT_FLAGS_TCP) {
ehp->bh_flags &= ~BPF_HDR_EXT_FLAGS_TCP;
found = inp_findinpcb_procinfo(&tcbinfo,
flowid, &soprocinfo);
} else if (ehp->bh_flags == BPF_HDR_EXT_FLAGS_UDP) {
ehp->bh_flags &= ~BPF_HDR_EXT_FLAGS_UDP;
found = inp_findinpcb_procinfo(&udbinfo,
flowid, &soprocinfo);
}
if (found == 1) {
ehp->bh_pid = soprocinfo.spi_pid;
strlcpy(&ehp->bh_comm[0], &soprocinfo.spi_proc_name[0], sizeof(ehp->bh_comm));
}
ehp->bh_flowid = 0;
}
if ((flags & BPF_FINALIZE_PKTAP) != 0 && ehp->bh_complen == 0) {
struct pktap_header *pktaphdr;
pktaphdr = (struct pktap_header *)(void *)
(p + BPF_WORDALIGN(ehp->bh_hdrlen));
bpf_finalize_pktap((struct bpf_hdr *) ehp,
pktaphdr);
}
p += BPF_WORDALIGN(ehp->bh_hdrlen + ehp->bh_caplen);
}
} else if (flags & BPF_FINALIZE_PKTAP) {
char *p;
p = hbuf;
while (p < hbuf + hbuf_len) {
struct bpf_hdr *hp;
struct pktap_header *pktaphdr;
hp = (struct bpf_hdr *)(void *)p;
/*
* Cannot finalize a compressed pktap header as we may not have
* all the fields present
*/
if (d->bd_flags & BPF_COMP_ENABLED) {
struct bpf_comp_hdr *hcp;
hcp = (struct bpf_comp_hdr *)(void *)p;
if (hcp->bh_complen != 0) {
p += BPF_WORDALIGN(hcp->bh_hdrlen + hcp->bh_caplen);
continue;
}
}
pktaphdr = (struct pktap_header *)(void *)
(p + BPF_WORDALIGN(hp->bh_hdrlen));
bpf_finalize_pktap(hp, pktaphdr);
p += BPF_WORDALIGN(hp->bh_hdrlen + hp->bh_caplen);
}
}
/*
* 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(hbuf, hbuf_len, uio);
lck_mtx_lock(bpf_mlock);
/*
* Make sure device is still opened
*/
if ((d->bd_flags & BPF_CLOSING) != 0) {
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
d->bd_hbuf_read = false;
d->bd_fbuf = d->bd_hbuf;
d->bd_hbuf = NULL;
d->bd_hlen = 0;
d->bd_hcnt = 0;
wakeup((caddr_t)d);
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return error;
}
/*
* If there are processes sleeping on this descriptor, wake them up.
*/
static void
bpf_wakeup(struct bpf_d *d)
{
if (d->bd_state == BPF_WAITING) {
bpf_stop_timer(d);
d->bd_state = BPF_IDLE;
}
wakeup((caddr_t)d);
if (d->bd_async && d->bd_sig && d->bd_sigio) {
pgsigio(d->bd_sigio, d->bd_sig);
}
selwakeup(&d->bd_sel);
if ((d->bd_flags & BPF_KNOTE)) {
KNOTE(&d->bd_sel.si_note, 1);
}
}
static void
bpf_timed_out(void *arg, __unused void *dummy)
{
struct bpf_d *d = (struct bpf_d *)arg;
lck_mtx_lock(bpf_mlock);
if (d->bd_state == BPF_WAITING) {
/*
* There's a select or kqueue waiting for this; if there's
* now stuff to read, wake it up.
*/
d->bd_state = BPF_TIMED_OUT;
if (d->bd_slen != 0) {
bpf_wakeup(d);
}
} else if (d->bd_state == BPF_DRAINING) {
/*
* A close is waiting for this to finish.
* Mark it as finished, and wake the close up.
*/
d->bd_state = BPF_IDLE;
bpf_wakeup(d);
}
lck_mtx_unlock(bpf_mlock);
}
/* keep in sync with bpf_movein above: */
#define MAX_DATALINK_HDR_LEN (sizeof(struct firewire_header))
int
bpfwrite(dev_t dev, struct uio *uio, __unused int ioflag)
{
struct bpf_d *d;
struct ifnet *ifp;
struct mbuf *m = NULL;
int error = 0;
char dst_buf[SOCKADDR_HDR_LEN + MAX_DATALINK_HDR_LEN];
int bif_dlt;
int bd_hdrcmplt;
bpf_send_func bif_send;
lck_mtx_lock(bpf_mlock);
while (true) {
d = bpf_dtab[minor(dev)];
if (d == NULL || d == BPF_DEV_RESERVED ||
(d->bd_flags & BPF_CLOSING) != 0) {
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
if (d->bd_hbuf_write) {
msleep((caddr_t)d, bpf_mlock, PRINET, "bpfwrite",
NULL);
} else {
break;
}
}
d->bd_hbuf_write = true;
bpf_acquire_d(d);
++d->bd_wcount;
if (d->bd_bif == NULL) {
error = ENXIO;
goto done;
}
ifp = d->bd_bif->bif_ifp;
if (IFNET_IS_MANAGEMENT(ifp) &&
IOCurrentTaskHasEntitlement(MANAGEMENT_DATA_ENTITLEMENT) == false) {
++d->bd_wdcount;
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return ENETDOWN;
}
if ((ifp->if_flags & IFF_UP) == 0) {
error = ENETDOWN;
goto done;
}
int resid = (int)uio_resid(uio);
if (resid <= 0) {
error = resid == 0 ? 0 : EINVAL;
os_log(OS_LOG_DEFAULT, "bpfwrite: resid %d error %d", resid, error);
goto done;
}
SA(dst_buf)->sa_len = sizeof(dst_buf);
/*
* geting variables onto stack before dropping the lock
*/
bif_dlt = (int)d->bd_bif->bif_dlt;
bd_hdrcmplt = d->bd_hdrcmplt;
bool batch_write = (d->bd_flags & BPF_BATCH_WRITE) ? true : false;
if (batch_write) {
error = bpf_movein_batch(uio, d, &m, bd_hdrcmplt ? NULL : SA(dst_buf));
if (error != 0) {
goto done;
}
} else {
error = bpf_movein(uio, resid, d, &m, bd_hdrcmplt ? NULL : SA(dst_buf));
if (error != 0) {
goto done;
}
bpf_set_packet_service_class(m, d->bd_traffic_class);
}
/* verify the device is still open */
if ((d->bd_flags & BPF_CLOSING) != 0) {
error = ENXIO;
goto done;
}
if (d->bd_bif == NULL || d->bd_bif->bif_ifp != ifp) {
error = ENXIO;
goto done;
}
bif_send = d->bd_bif->bif_send;
lck_mtx_unlock(bpf_mlock);
if (bd_hdrcmplt) {
if (bif_send) {
/*
* Send one packet at a time, the driver frees the mbuf
* but we need to take care of the leftover
*/
while (m != NULL && error == 0) {
struct mbuf *next = m->m_nextpkt;
m->m_nextpkt = NULL;
error = bif_send(ifp, bif_dlt, m);
m = next;
}
} else {
error = dlil_output(ifp, 0, m, NULL, NULL, 1, NULL);
/* Make sure we do not double free */
m = NULL;
}
} else {
error = dlil_output(ifp, PF_INET, m, NULL,
SA(dst_buf), 0, NULL);
/* Make sure we do not double free */
m = NULL;
}
lck_mtx_lock(bpf_mlock);
done:
if (error != 0 && m != NULL) {
++d->bd_wdcount;
}
if (m != NULL) {
m_freem_list(m);
}
d->bd_hbuf_write = false;
wakeup((caddr_t)d);
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
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)
{
if (d->bd_hbuf_read) {
panic("resetting buffers during read");
}
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_scnt = 0;
d->bd_hcnt = 0;
d->bd_rcount = 0;
d->bd_dcount = 0;
d->bd_fcount = 0;
d->bd_wcount = 0;
d->bd_wdcount = 0;
d->bd_prev_slen = 0;
}
static struct bpf_d *
bpf_get_device_from_uuid(uuid_t uuid)
{
unsigned int i;
for (i = 0; i < nbpfilter; i++) {
struct bpf_d *d = bpf_dtab[i];
if (d == NULL || d == BPF_DEV_RESERVED ||
(d->bd_flags & BPF_CLOSING) != 0) {
continue;
}
if (uuid_compare(uuid, d->bd_uuid) == 0) {
return d;
}
}
return NULL;
}
/*
* The BIOCSETUP command "atomically" attach to the interface and
* copy the buffer from another interface. This minimizes the risk
* of missing packet because this is done while holding
* the BPF global lock
*/
static int
bpf_setup(struct bpf_d *d_to, uuid_t uuid_from, ifnet_t ifp)
{
struct bpf_d *d_from;
int error = 0;
LCK_MTX_ASSERT(bpf_mlock, LCK_MTX_ASSERT_OWNED);
/*
* Sanity checks
*/
d_from = bpf_get_device_from_uuid(uuid_from);
if (d_from == NULL) {
error = ENOENT;
os_log_error(OS_LOG_DEFAULT,
"%s: uuids not found error %d",
__func__, error);
return error;
}
if (d_from->bd_opened_by != d_to->bd_opened_by) {
error = EACCES;
os_log_error(OS_LOG_DEFAULT,
"%s: processes not matching error %d",
__func__, error);
return error;
}
/*
* Prevent any read or write while copying
*/
while (d_to->bd_hbuf_read || d_to->bd_hbuf_write) {
msleep((caddr_t)d_to, bpf_mlock, PRINET, __func__, NULL);
}
d_to->bd_hbuf_read = true;
d_to->bd_hbuf_write = true;
while (d_from->bd_hbuf_read || d_from->bd_hbuf_write) {
msleep((caddr_t)d_from, bpf_mlock, PRINET, __func__, NULL);
}
d_from->bd_hbuf_read = true;
d_from->bd_hbuf_write = true;
/*
* Verify the devices have not been closed
*/
if (d_to->bd_flags & BPF_CLOSING) {
error = ENXIO;
os_log_error(OS_LOG_DEFAULT,
"%s: d_to is closing error %d",
__func__, error);
goto done;
}
if (d_from->bd_flags & BPF_CLOSING) {
error = ENXIO;
os_log_error(OS_LOG_DEFAULT,
"%s: d_from is closing error %d",
__func__, error);
goto done;
}
/*
* For now require the same buffer size
*/
if (d_from->bd_bufsize != d_to->bd_bufsize) {
error = EINVAL;
os_log_error(OS_LOG_DEFAULT,
"%s: bufsizes not matching error %d",
__func__, error);
goto done;
}
/*
* Copy relevant options and flags
*/
d_to->bd_flags = d_from->bd_flags & (BPF_EXTENDED_HDR | BPF_WANT_PKTAP |
BPF_FINALIZE_PKTAP | BPF_TRUNCATE | BPF_PKTHDRV2 |
BPF_COMP_REQ | BPF_COMP_ENABLED);
d_to->bd_headdrop = d_from->bd_headdrop;
/*
* Allocate and copy the buffers
*/
error = bpf_allocbufs(d_to);
if (error != 0) {
goto done;
}
/*
* Make sure the buffers are setup as expected by bpf_setif()
*/
ASSERT(d_to->bd_hbuf == NULL);
ASSERT(d_to->bd_sbuf != NULL);
ASSERT(d_to->bd_fbuf != NULL);
/*
* Copy the buffers and update the pointers and counts
*/
memcpy(d_to->bd_sbuf, d_from->bd_sbuf, d_from->bd_slen);
d_to->bd_slen = d_from->bd_slen;
d_to->bd_scnt = d_from->bd_scnt;
if (d_from->bd_hbuf != NULL) {
d_to->bd_hbuf = d_to->bd_fbuf;
d_to->bd_fbuf = NULL;
memcpy(d_to->bd_hbuf, d_from->bd_hbuf, d_from->bd_hlen);
}
d_to->bd_hlen = d_from->bd_hlen;
d_to->bd_hcnt = d_from->bd_hcnt;
if (d_to->bd_flags & BPF_COMP_REQ) {
ASSERT(d_to->bd_prev_sbuf != NULL);
ASSERT(d_to->bd_prev_fbuf != NULL);
d_to->bd_prev_slen = d_from->bd_prev_slen;
ASSERT(d_to->bd_prev_slen <= BPF_HDR_COMP_LEN_MAX);
memcpy(d_to->bd_prev_sbuf, d_from->bd_prev_sbuf, BPF_HDR_COMP_LEN_MAX);
}
d_to->bd_bcs = d_from->bd_bcs;
/*
* Attach to the interface:
* - don't reset the buffers
* - we already prevent reads and writes
* - the buffers are already allocated
*/
error = bpf_setif(d_to, ifp, false, true, true);
if (error != 0) {
os_log_error(OS_LOG_DEFAULT,
"%s: bpf_setif() failed error %d",
__func__, error);
goto done;
}
done:
d_from->bd_hbuf_read = false;
d_from->bd_hbuf_write = false;
wakeup((caddr_t)d_from);
d_to->bd_hbuf_read = false;
d_to->bd_hbuf_write = false;
wakeup((caddr_t)d_to);
return error;
}
#if DEVELOPMENT || DEBUG
#define BPF_IOC_LIST \
X(FIONREAD) \
X(SIOCGIFADDR) \
X(BIOCGBLEN) \
X(BIOCSBLEN) \
X(BIOCSETF32) \
X(BIOCSETFNR32) \
X(BIOCSETF64) \
X(BIOCSETFNR64) \
X(BIOCFLUSH) \
X(BIOCPROMISC) \
X(BIOCGDLT) \
X(BIOCGDLTLIST) \
X(BIOCSDLT) \
X(BIOCGETIF) \
X(BIOCSETIF) \
X(BIOCSRTIMEOUT32) \
X(BIOCSRTIMEOUT64) \
X(BIOCGRTIMEOUT32) \
X(BIOCGRTIMEOUT64) \
X(BIOCGSTATS) \
X(BIOCIMMEDIATE) \
X(BIOCVERSION) \
X(BIOCGHDRCMPLT) \
X(BIOCSHDRCMPLT) \
X(BIOCGSEESENT) \
X(BIOCSSEESENT) \
X(BIOCSETTC) \
X(BIOCGETTC) \
X(FIONBIO) \
X(FIOASYNC) \
X(BIOCSRSIG) \
X(BIOCGRSIG) \
X(BIOCSEXTHDR) \
X(BIOCGIFATTACHCOUNT) \
X(BIOCGWANTPKTAP) \
X(BIOCSWANTPKTAP) \
X(BIOCSHEADDROP) \
X(BIOCGHEADDROP) \
X(BIOCSTRUNCATE) \
X(BIOCGETUUID) \
X(BIOCSETUP) \
X(BIOCSPKTHDRV2) \
X(BIOCGHDRCOMP) \
X(BIOCSHDRCOMP) \
X(BIOCGHDRCOMPSTATS) \
X(BIOCGHDRCOMPON) \
X(BIOCGDIRECTION) \
X(BIOCSDIRECTION) \
X(BIOCSWRITEMAX) \
X(BIOCGWRITEMAX) \
X(BIOCGBATCHWRITE) \
X(BIOCSBATCHWRITE)
static void
log_bpf_ioctl_str(struct bpf_d *d, u_long cmd)
{
const char *p = NULL;
char str[32];
#define X(x) case x: { p = #x ; printf("%s\n", p); break; }
switch (cmd) {
BPF_IOC_LIST
}
#undef X
if (p == NULL) {
snprintf(str, sizeof(str), "0x%08x", (unsigned int)cmd);
p = str;
}
os_log(OS_LOG_DEFAULT, "bpfioctl bpf%u %s",
d->bd_dev_minor, p);
}
#endif /* DEVELOPMENT || DEBUG */
/*
* 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
* BIOCGSEESENT Get "see packets sent" flag
* BIOCSSEESENT Set "see packets sent" flag
* BIOCSETTC Set traffic class.
* BIOCGETTC Get traffic class.
* BIOCSEXTHDR Set "extended header" flag
* BIOCSHEADDROP Drop head of the buffer if user is not reading
* BIOCGHEADDROP Get "head-drop" flag
*/
/* ARGSUSED */
int
bpfioctl(dev_t dev, u_long cmd, caddr_t addr, __unused int flags,
struct proc *p)
{
struct bpf_d *d;
int error = 0;
u_int int_arg;
struct ifreq ifr = {};
lck_mtx_lock(bpf_mlock);
d = bpf_dtab[minor(dev)];
if (d == NULL || d == BPF_DEV_RESERVED ||
(d->bd_flags & BPF_CLOSING) != 0) {
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
bpf_acquire_d(d);
if (d->bd_state == BPF_WAITING) {
bpf_stop_timer(d);
}
d->bd_state = BPF_IDLE;
#if DEVELOPMENT || DEBUG
if (bpf_debug > 0) {
log_bpf_ioctl_str(d, cmd);
}
#endif /* DEVELOPMENT || DEBUG */
switch (cmd) {
default:
error = EINVAL;
break;
/*
* Check for read packet available.
*/
case FIONREAD: /* int */
{
int n;
n = d->bd_slen;
if (d->bd_hbuf && d->bd_hbuf_read) {
n += d->bd_hlen;
}
bcopy(&n, addr, sizeof(n));
break;
}
case SIOCGIFADDR: /* struct ifreq */
{
struct ifnet *ifp;
if (d->bd_bif == 0) {
error = EINVAL;
} else {
ifp = d->bd_bif->bif_ifp;
error = ifnet_ioctl(ifp, 0, cmd, addr);
}
break;
}
/*
* Get buffer len [for read()].
*/
case BIOCGBLEN: /* u_int */
bcopy(&d->bd_bufsize, addr, sizeof(u_int));
break;
/*
* Set buffer length.
*/
case BIOCSBLEN: { /* u_int */
u_int size;
if (d->bd_bif != 0 || (d->bd_flags & BPF_DETACHING)) {
/*
* Interface already attached, unable to change buffers
*/
error = EINVAL;
break;
}
bcopy(addr, &size, sizeof(size));
if (size > BPF_BUFSIZE_CAP) {
d->bd_bufsize = BPF_BUFSIZE_CAP;
os_log_info(OS_LOG_DEFAULT,
"bpf%d BIOCSBLEN capped to %u from %u",
minor(dev), d->bd_bufsize, size);
} else if (size < BPF_MINBUFSIZE) {
d->bd_bufsize = BPF_MINBUFSIZE;
os_log_info(OS_LOG_DEFAULT,
"bpf%d BIOCSBLEN bumped to %u from %u",
minor(dev), d->bd_bufsize, size);
} else {
d->bd_bufsize = size;
os_log_info(OS_LOG_DEFAULT,
"bpf%d BIOCSBLEN %u",
minor(dev), d->bd_bufsize);
}
/* It's a read/write ioctl */
bcopy(&d->bd_bufsize, addr, sizeof(u_int));
break;
}
/*
* Set link layer read filter.
*/
case BIOCSETF32:
case BIOCSETFNR32: { /* struct bpf_program32 */
struct bpf_program32 prg32;
bcopy(addr, &prg32, sizeof(prg32));
error = bpf_setf(d, prg32.bf_len,
CAST_USER_ADDR_T(prg32.bf_insns), cmd);
break;
}
case BIOCSETF64:
case BIOCSETFNR64: { /* struct bpf_program64 */
struct bpf_program64 prg64;
bcopy(addr, &prg64, sizeof(prg64));
error = bpf_setf(d, prg64.bf_len, CAST_USER_ADDR_T(prg64.bf_insns), cmd);
break;
}
/*
* Flush read packet buffer.
*/
case BIOCFLUSH:
while (d->bd_hbuf_read) {
msleep((caddr_t)d, bpf_mlock, PRINET, "BIOCFLUSH",
NULL);
}
if ((d->bd_flags & BPF_CLOSING) != 0) {
error = ENXIO;
break;
}
reset_d(d);
break;
/*
* Put interface into promiscuous mode.
*/
case BIOCPROMISC:
if (d->bd_bif == 0) {
/*
* No interface attached yet.
*/
error = EINVAL;
break;
}
if (d->bd_promisc == 0) {
lck_mtx_unlock(bpf_mlock);
error = ifnet_set_promiscuous(d->bd_bif->bif_ifp, 1);
lck_mtx_lock(bpf_mlock);
if (error == 0) {
d->bd_promisc = 1;
}
}
break;
/*
* Get device parameters.
*/
case BIOCGDLT: /* u_int */
if (d->bd_bif == 0) {
error = EINVAL;
} else {
bcopy(&d->bd_bif->bif_dlt, addr, sizeof(u_int));
}
break;
/*
* Get a list of supported data link types.
*/
case BIOCGDLTLIST: /* struct bpf_dltlist */
if (d->bd_bif == NULL) {
error = EINVAL;
} else {
error = bpf_getdltlist(d, addr, p);
}
break;
/*
* Set data link type.
*/
case BIOCSDLT: /* u_int */
if (d->bd_bif == NULL) {
error = EINVAL;
} else {
u_int dlt;
bcopy(addr, &dlt, sizeof(dlt));
if (dlt == DLT_PKTAP &&
!(d->bd_flags & BPF_WANT_PKTAP)) {
dlt = DLT_RAW;
}
error = bpf_setdlt(d, dlt);
}
break;
/*
* Get interface name.
*/
case BIOCGETIF: /* struct ifreq */
if (d->bd_bif == 0) {
error = EINVAL;
} else {
struct ifnet *const ifp = d->bd_bif->bif_ifp;
snprintf(((struct ifreq *)(void *)addr)->ifr_name,
sizeof(ifr.ifr_name), "%s", if_name(ifp));
}
break;
/*
* Set interface.
*/
case BIOCSETIF: { /* struct ifreq */
ifnet_t ifp;
bcopy(addr, &ifr, sizeof(ifr));
ifr.ifr_name[IFNAMSIZ - 1] = '\0';
ifp = ifunit(ifr.ifr_name);
if (ifp == NULL) {
error = ENXIO;
} else {
error = bpf_setif(d, ifp, true, false, false);
}
break;
}
/*
* Set read timeout.
*/
case BIOCSRTIMEOUT32: { /* struct user32_timeval */
struct user32_timeval _tv;
struct timeval tv;
bcopy(addr, &_tv, sizeof(_tv));
tv.tv_sec = _tv.tv_sec;
tv.tv_usec = _tv.tv_usec;
/*
* 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;
}
case BIOCSRTIMEOUT64: { /* struct user64_timeval */
struct user64_timeval _tv;
struct timeval tv;
bcopy(addr, &_tv, sizeof(_tv));
tv.tv_sec = (__darwin_time_t)_tv.tv_sec;
tv.tv_usec = _tv.tv_usec;
/*
* 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 BIOCGRTIMEOUT32: { /* struct user32_timeval */
struct user32_timeval tv;
bzero(&tv, sizeof(tv));
tv.tv_sec = d->bd_rtout / hz;
tv.tv_usec = (d->bd_rtout % hz) * tick;
bcopy(&tv, addr, sizeof(tv));
break;
}
case BIOCGRTIMEOUT64: { /* struct user64_timeval */
struct user64_timeval tv;
bzero(&tv, sizeof(tv));
tv.tv_sec = d->bd_rtout / hz;
tv.tv_usec = (d->bd_rtout % hz) * tick;
bcopy(&tv, addr, sizeof(tv));
break;
}
/*
* Get packet stats.
*/
case BIOCGSTATS: { /* struct bpf_stat */
struct bpf_stat bs;
bzero(&bs, sizeof(bs));
bs.bs_recv = (u_int)d->bd_rcount;
bs.bs_drop = (u_int)d->bd_dcount;
bcopy(&bs, addr, sizeof(bs));
break;
}
/*
* Set immediate mode.
*/
case BIOCIMMEDIATE: /* u_int */
d->bd_immediate = *(u_char *)(void *)addr;
break;
case BIOCVERSION: { /* struct bpf_version */
struct bpf_version bv;
bzero(&bv, sizeof(bv));
bv.bv_major = BPF_MAJOR_VERSION;
bv.bv_minor = BPF_MINOR_VERSION;
bcopy(&bv, addr, sizeof(bv));
break;
}
/*
* Get "header already complete" flag
*/
case BIOCGHDRCMPLT: /* u_int */
bcopy(&d->bd_hdrcmplt, addr, sizeof(u_int));
break;
/*
* Set "header already complete" flag
*/
case BIOCSHDRCMPLT: /* u_int */
bcopy(addr, &int_arg, sizeof(int_arg));
if (int_arg == 0 && (d->bd_flags & BPF_BATCH_WRITE)) {
os_log(OS_LOG_DEFAULT,
"bpf%u cannot set BIOCSHDRCMPLT when BIOCSBATCHWRITE is set",
d->bd_dev_minor);
error = EINVAL;
break;
}
d->bd_hdrcmplt = int_arg ? 1 : 0;
break;
/*
* Get "see sent packets" flag
*/
case BIOCGSEESENT: { /* u_int */
int_arg = 0;
if (d->bd_direction & BPF_D_OUT) {
int_arg = 1;
}
bcopy(&int_arg, addr, sizeof(u_int));
break;
}
/*
* Set "see sent packets" flag
*/
case BIOCSSEESENT: { /* u_int */
bcopy(addr, &int_arg, sizeof(u_int));
if (int_arg == 0) {
d->bd_direction = BPF_D_IN;
} else {
d->bd_direction = BPF_D_INOUT;
}
break;
}
/*
* Get direction of tapped packets that can be seen for reading
*/
case BIOCGDIRECTION: { /* u_int */
int_arg = d->bd_direction;
bcopy(&int_arg, addr, sizeof(u_int));
break;
}
/*
* Set direction of tapped packets that can be seen for reading
*/
case BIOCSDIRECTION: { /* u_int */
bcopy(addr, &int_arg, sizeof(u_int));
switch (int_arg) {
case BPF_D_NONE:
case BPF_D_IN:
case BPF_D_OUT:
case BPF_D_INOUT:
d->bd_direction = int_arg;
break;
default:
error = EINVAL;
break;
}
break;
}
/*
* Set traffic service class
*/
case BIOCSETTC: { /* int */
int tc;
bcopy(addr, &tc, sizeof(int));
if (tc != 0 && (d->bd_flags & BPF_BATCH_WRITE)) {
os_log(OS_LOG_DEFAULT,
"bpf%u cannot set BIOCSETTC when BIOCSBATCHWRITE is set",
d->bd_dev_minor);
error = EINVAL;
break;
}
error = bpf_set_traffic_class(d, tc);
break;
}
/*
* Get traffic service class
*/
case BIOCGETTC: /* int */
bcopy(&d->bd_traffic_class, addr, sizeof(int));
break;
case FIONBIO: /* Non-blocking I/O; int */
break;
case FIOASYNC: /* Send signal on receive packets; int */
bcopy(addr, &d->bd_async, sizeof(int));
break;
case BIOCSRSIG: { /* Set receive signal; u_int */
u_int sig;
bcopy(addr, &sig, sizeof(u_int));
if (sig >= NSIG) {
error = EINVAL;
} else {
d->bd_sig = sig;
}
break;
}
case BIOCGRSIG: /* u_int */
bcopy(&d->bd_sig, addr, sizeof(u_int));
break;
case BIOCSEXTHDR: /* u_int */
bcopy(addr, &int_arg, sizeof(int_arg));
if (int_arg) {
d->bd_flags |= BPF_EXTENDED_HDR;
} else {
d->bd_flags &= ~BPF_EXTENDED_HDR;
}
break;
case BIOCGIFATTACHCOUNT: { /* struct ifreq */
ifnet_t ifp;
struct bpf_if *bp;
bcopy(addr, &ifr, sizeof(ifr));
ifr.ifr_name[IFNAMSIZ - 1] = '\0';
ifp = ifunit(ifr.ifr_name);
if (ifp == NULL) {
error = ENXIO;
break;
}
ifr.ifr_intval = 0;
for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) {
struct bpf_d *bpf_d;
if (bp->bif_ifp == NULL || bp->bif_ifp != ifp) {
continue;
}
for (bpf_d = bp->bif_dlist; bpf_d;
bpf_d = bpf_d->bd_next) {
ifr.ifr_intval += 1;
}
}
bcopy(&ifr, addr, sizeof(ifr));
break;
}
case BIOCGWANTPKTAP: /* u_int */
int_arg = d->bd_flags & BPF_WANT_PKTAP ? 1 : 0;
bcopy(&int_arg, addr, sizeof(int_arg));
break;
case BIOCSWANTPKTAP: /* u_int */
bcopy(addr, &int_arg, sizeof(int_arg));
if (int_arg) {
d->bd_flags |= BPF_WANT_PKTAP;
} else {
d->bd_flags &= ~BPF_WANT_PKTAP;
}
break;
case BIOCSHEADDROP:
bcopy(addr, &int_arg, sizeof(int_arg));
d->bd_headdrop = int_arg ? 1 : 0;
break;
case BIOCGHEADDROP:
bcopy(&d->bd_headdrop, addr, sizeof(int));
break;
case BIOCSTRUNCATE:
bcopy(addr, &int_arg, sizeof(int_arg));
if (int_arg) {
d->bd_flags |= BPF_TRUNCATE;
} else {
d->bd_flags &= ~BPF_TRUNCATE;
}
break;
case BIOCGETUUID:
bcopy(&d->bd_uuid, addr, sizeof(uuid_t));
break;
case BIOCSETUP: {
struct bpf_setup_args bsa;
ifnet_t ifp;
bcopy(addr, &bsa, sizeof(struct bpf_setup_args));
bsa.bsa_ifname[IFNAMSIZ - 1] = 0;
ifp = ifunit(bsa.bsa_ifname);
if (ifp == NULL) {
error = ENXIO;
os_log_error(OS_LOG_DEFAULT,
"%s: ifnet not found for %s error %d",
__func__, bsa.bsa_ifname, error);
break;
}
error = bpf_setup(d, bsa.bsa_uuid, ifp);
break;
}
case BIOCSPKTHDRV2:
bcopy(addr, &int_arg, sizeof(int_arg));
if (int_arg != 0) {
d->bd_flags |= BPF_PKTHDRV2;
} else {
d->bd_flags &= ~BPF_PKTHDRV2;
}
break;
case BIOCGPKTHDRV2:
int_arg = d->bd_flags & BPF_PKTHDRV2 ? 1 : 0;
bcopy(&int_arg, addr, sizeof(int_arg));
break;
case BIOCGHDRCOMP:
int_arg = d->bd_flags & BPF_COMP_REQ ? 1 : 0;
bcopy(&int_arg, addr, sizeof(int_arg));
break;
case BIOCSHDRCOMP:
bcopy(addr, &int_arg, sizeof(int_arg));
if (int_arg != 0 && int_arg != 1) {
return EINVAL;
}
if (d->bd_bif != 0 || (d->bd_flags & BPF_DETACHING)) {
/*
* Interface already attached, unable to change buffers
*/
error = EINVAL;
break;
}
if (int_arg != 0) {
d->bd_flags |= BPF_COMP_REQ;
if (bpf_hdr_comp_enable != 0) {
d->bd_flags |= BPF_COMP_ENABLED;
}
} else {
d->bd_flags &= ~(BPF_COMP_REQ | BPF_COMP_ENABLED);
}
break;
case BIOCGHDRCOMPON:
int_arg = d->bd_flags & BPF_COMP_ENABLED ? 1 : 0;
bcopy(&int_arg, addr, sizeof(int_arg));
break;
case BIOCGHDRCOMPSTATS: {
struct bpf_comp_stats bcs = {};
bcs = d->bd_bcs;
bcopy(&bcs, addr, sizeof(bcs));
break;
}
case BIOCSWRITEMAX:
bcopy(addr, &int_arg, sizeof(int_arg));
if (int_arg > BPF_WRITE_MAX) {
os_log(OS_LOG_DEFAULT, "bpf%u bd_write_size_max %u too big",
d->bd_dev_minor, d->bd_write_size_max);
error = EINVAL;
break;
}
d->bd_write_size_max = int_arg;
break;
case BIOCGWRITEMAX:
int_arg = d->bd_write_size_max;
bcopy(&int_arg, addr, sizeof(int_arg));
break;
case BIOCGBATCHWRITE: /* int */
int_arg = d->bd_flags & BPF_BATCH_WRITE ? 1 : 0;
bcopy(&int_arg, addr, sizeof(int_arg));
break;
case BIOCSBATCHWRITE: /* int */
bcopy(addr, &int_arg, sizeof(int_arg));
if (int_arg != 0) {
if (d->bd_hdrcmplt == 0) {
os_log(OS_LOG_DEFAULT,
"bpf%u cannot set BIOCSBATCHWRITE when BIOCSHDRCMPLT is not set",
d->bd_dev_minor);
error = EINVAL;
break;
}
if (d->bd_traffic_class != 0) {
os_log(OS_LOG_DEFAULT,
"bpf%u cannot set BIOCSBATCHWRITE when BIOCSETTC is set",
d->bd_dev_minor);
error = EINVAL;
break;
}
d->bd_flags |= BPF_BATCH_WRITE;
} else {
d->bd_flags &= ~BPF_BATCH_WRITE;
}
break;
}
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
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, u_int bf_len, user_addr_t bf_insns,
u_long cmd)
{
struct bpf_insn *fcode, *old;
u_int flen, size;
while (d->bd_hbuf_read) {
msleep((caddr_t)d, bpf_mlock, PRINET, "bpf_setf", NULL);
}
if ((d->bd_flags & BPF_CLOSING) != 0) {
return ENXIO;
}
old = d->bd_filter;
if (bf_insns == USER_ADDR_NULL) {
if (bf_len != 0) {
return EINVAL;
}
d->bd_filter = NULL;
reset_d(d);
if (old != 0) {
kfree_data_addr(old);
}
return 0;
}
flen = bf_len;
if (flen > BPF_MAXINSNS) {
return EINVAL;
}
size = flen * sizeof(struct bpf_insn);
fcode = (struct bpf_insn *) kalloc_data(size, Z_WAITOK | Z_ZERO);
if (fcode == NULL) {
return ENOMEM;
}
if (copyin(bf_insns, (caddr_t)fcode, size) == 0 &&
bpf_validate(fcode, (int)flen)) {
d->bd_filter = fcode;
if (cmd == BIOCSETF32 || cmd == BIOCSETF64) {
reset_d(d);
}
if (old != 0) {
kfree_data_addr(old);
}
return 0;
}
kfree_data(fcode, size);
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, ifnet_t theywant, bool do_reset, bool has_hbuf_read_write,
bool has_bufs_allocated)
{
struct bpf_if *bp;
int error;
while (!has_hbuf_read_write && (d->bd_hbuf_read || d->bd_hbuf_write)) {
msleep((caddr_t)d, bpf_mlock, PRINET, "bpf_setif", NULL);
}
if ((d->bd_flags & BPF_CLOSING) != 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;
}
/*
* Do not use DLT_PKTAP, unless requested explicitly
*/
if (bp->bif_dlt == DLT_PKTAP && !(d->bd_flags & BPF_WANT_PKTAP)) {
continue;
}
/*
* Skip the coprocessor interface
*/
if (!intcoproc_unrestricted && IFNET_IS_INTCOPROC(ifp)) {
continue;
}
/*
* We found the requested interface.
* Allocate the packet buffers.
*/
if (has_bufs_allocated == false) {
error = bpf_allocbufs(d);
if (error != 0) {
return error;
}
}
/*
* Detach if attached to something else.
*/
if (bp != d->bd_bif) {
if (d->bd_bif != NULL) {
if (bpf_detachd(d) != 0) {
return ENXIO;
}
}
if (bpf_attachd(d, bp) != 0) {
return ENXIO;
}
}
if (do_reset) {
reset_d(d);
}
os_log(OS_LOG_DEFAULT, "bpf%u attached to %s",
d->bd_dev_minor, if_name(theywant));
return 0;
}
/* Not found. */
return ENXIO;
}
/*
* Get a list of available data link type of the interface.
*/
static int
bpf_getdltlist(struct bpf_d *d, caddr_t addr, struct proc *p)
{
u_int n;
int error;
struct ifnet *ifp;
struct bpf_if *bp;
user_addr_t dlist;
struct bpf_dltlist bfl;
bcopy(addr, &bfl, sizeof(bfl));
if (proc_is64bit(p)) {
dlist = (user_addr_t)bfl.bfl_u.bflu_pad;
} else {
dlist = CAST_USER_ADDR_T(bfl.bfl_u.bflu_list);
}
ifp = d->bd_bif->bif_ifp;
n = 0;
error = 0;
for (bp = bpf_iflist; bp; bp = bp->bif_next) {
if (bp->bif_ifp != ifp) {
continue;
}
/*
* Do not use DLT_PKTAP, unless requested explicitly
*/
if (bp->bif_dlt == DLT_PKTAP && !(d->bd_flags & BPF_WANT_PKTAP)) {
continue;
}
if (dlist != USER_ADDR_NULL) {
if (n >= bfl.bfl_len) {
return ENOMEM;
}
error = copyout(&bp->bif_dlt, dlist,
sizeof(bp->bif_dlt));
if (error != 0) {
break;
}
dlist += sizeof(bp->bif_dlt);
}
n++;
}
bfl.bfl_len = n;
bcopy(&bfl, addr, sizeof(bfl));
return error;
}
/*
* Set the data link type of a BPF instance.
*/
static int
bpf_setdlt(struct bpf_d *d, uint32_t dlt)
{
int error, opromisc;
struct ifnet *ifp;
struct bpf_if *bp;
if (d->bd_bif->bif_dlt == dlt) {
return 0;
}
while (d->bd_hbuf_read) {
msleep((caddr_t)d, bpf_mlock, PRINET, "bpf_setdlt", NULL);
}
if ((d->bd_flags & BPF_CLOSING) != 0) {
return ENXIO;
}
ifp = d->bd_bif->bif_ifp;
for (bp = bpf_iflist; bp; bp = bp->bif_next) {
if (bp->bif_ifp == ifp && bp->bif_dlt == dlt) {
/*
* Do not use DLT_PKTAP, unless requested explicitly
*/
if (bp->bif_dlt == DLT_PKTAP &&
!(d->bd_flags & BPF_WANT_PKTAP)) {
continue;
}
break;
}
}
if (bp != NULL) {
opromisc = d->bd_promisc;
if (bpf_detachd(d) != 0) {
return ENXIO;
}
error = bpf_attachd(d, bp);
if (error != 0) {
os_log_error(OS_LOG_DEFAULT,
"bpf_setdlt: bpf%d bpf_attachd %s error %d",
d->bd_dev_minor, if_name(bp->bif_ifp),
error);
return error;
}
reset_d(d);
if (opromisc) {
lck_mtx_unlock(bpf_mlock);
error = ifnet_set_promiscuous(bp->bif_ifp, 1);
lck_mtx_lock(bpf_mlock);
if (error != 0) {
os_log_error(OS_LOG_DEFAULT,
"bpf_setdlt: bpf%d ifpromisc %s error %d",
d->bd_dev_minor, if_name(bp->bif_ifp), error);
} else {
d->bd_promisc = 1;
}
}
}
return bp == NULL ? EINVAL : 0;
}
static int
bpf_set_traffic_class(struct bpf_d *d, int tc)
{
int error = 0;
if (!SO_VALID_TC(tc)) {
error = EINVAL;
} else {
d->bd_traffic_class = tc;
}
return error;
}
static void
bpf_set_packet_service_class(struct mbuf *m, int tc)
{
if (!(m->m_flags & M_PKTHDR)) {
return;
}
VERIFY(SO_VALID_TC(tc));
(void) m_set_service_class(m, so_tc2msc(tc));
}
/*
* Support for select()
*
* Return true iff the specific operation will not block indefinitely.
* Otherwise, return false but make a note that a selwakeup() must be done.
*/
int
bpfselect(dev_t dev, int which, void * wql, struct proc *p)
{
struct bpf_d *d;
int ret = 0;
lck_mtx_lock(bpf_mlock);
d = bpf_dtab[minor(dev)];
if (d == NULL || d == BPF_DEV_RESERVED ||
(d->bd_flags & BPF_CLOSING) != 0) {
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
bpf_acquire_d(d);
if (d->bd_bif == NULL) {
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
while (d->bd_hbuf_read) {
msleep((caddr_t)d, bpf_mlock, PRINET, "bpfselect", NULL);
}
if ((d->bd_flags & BPF_CLOSING) != 0) {
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return ENXIO;
}
switch (which) {
case FREAD:
if (d->bd_hlen != 0 ||
((d->bd_immediate ||
d->bd_state == BPF_TIMED_OUT) && d->bd_slen != 0)) {
ret = 1; /* read has data to return */
} else {
/*
* Read has no data to return.
* Make the select wait, and start a timer if
* necessary.
*/
selrecord(p, &d->bd_sel, wql);
bpf_start_timer(d);
}
break;
case FWRITE:
/* can't determine whether a write would block */
ret = 1;
break;
}
bpf_release_d(d);
lck_mtx_unlock(bpf_mlock);
return ret;
}
/*
* Support for kevent() system call. Register EVFILT_READ filters and
* reject all others.
*/
int bpfkqfilter(dev_t dev, struct knote *kn);
static void filt_bpfdetach(struct knote *);
static int filt_bpfread(struct knote *, long);
static int filt_bpftouch(struct knote *kn, struct kevent_qos_s *kev);
static int filt_bpfprocess(struct knote *kn, struct kevent_qos_s *kev);
SECURITY_READ_ONLY_EARLY(struct filterops) bpfread_filtops = {
.f_isfd = 1,
.f_detach = filt_bpfdetach,
.f_event = filt_bpfread,
.f_touch = filt_bpftouch,
.f_process = filt_bpfprocess,
};
static int
filt_bpfread_common(struct knote *kn, struct kevent_qos_s *kev, struct bpf_d *d)
{
int ready = 0;
int64_t data = 0;
if (d->bd_immediate) {
/*
* If there's data in the hold buffer, it's the
* amount of data a read will return.
*
* If there's no data in the hold buffer, but
* there's data in the store buffer, a read will
* immediately rotate the store buffer to the
* hold buffer, the amount of data in the store
* buffer is the amount of data a read will
* return.
*
* If there's no data in either buffer, we're not
* ready to read.
*/
data = (d->bd_hlen == 0 || d->bd_hbuf_read ?
d->bd_slen : d->bd_hlen);
int64_t lowwat = knote_low_watermark(kn);
if (lowwat > d->bd_bufsize) {
lowwat = d->bd_bufsize;
}
ready = (data >= lowwat);
} else {
/*
* If there's data in the hold buffer, it's the
* amount of data a read will return.
*
* If there's no data in the hold buffer, but
* there's data in the store buffer, if the
* timer has expired a read will immediately
* rotate the store buffer to the hold buffer,
* so the amount of data in the store buffer is
* the amount of data a read will return.
*
* If there's no data in either buffer, or there's
* no data in the hold buffer and the timer hasn't
* expired, we're not ready to read.
*/
data = ((d->bd_hlen == 0 || d->bd_hbuf_read) &&
d->bd_state == BPF_TIMED_OUT ? d->bd_slen : d->bd_hlen);
ready = (data > 0);
}
if (!ready) {
bpf_start_timer(d);
} else if (kev) {
knote_fill_kevent(kn, kev, data);
}
return ready;
}
int
bpfkqfilter(dev_t dev, struct knote *kn)
{
struct bpf_d *d;
int res;
/*
* Is this device a bpf?
*/
if (major(dev) != CDEV_MAJOR || kn->kn_filter != EVFILT_READ) {
knote_set_error(kn, EINVAL);
return 0;
}
lck_mtx_lock(bpf_mlock);
d = bpf_dtab[minor(dev)];
if (d == NULL || d == BPF_DEV_RESERVED ||
(d->bd_flags & BPF_CLOSING) != 0 ||
d->bd_bif == NULL) {
lck_mtx_unlock(bpf_mlock);
knote_set_error(kn, ENXIO);
return 0;
}
kn->kn_filtid = EVFILTID_BPFREAD;
knote_kn_hook_set_raw(kn, d);
KNOTE_ATTACH(&d->bd_sel.si_note, kn);
d->bd_flags |= BPF_KNOTE;
/* capture the current state */
res = filt_bpfread_common(kn, NULL, d);
lck_mtx_unlock(bpf_mlock);
return res;
}
static void
filt_bpfdetach(struct knote *kn)
{
struct bpf_d *d = (struct bpf_d *)knote_kn_hook_get_raw(kn);
lck_mtx_lock(bpf_mlock);
if (d->bd_flags & BPF_KNOTE) {
KNOTE_DETACH(&d->bd_sel.si_note, kn);
d->bd_flags &= ~BPF_KNOTE;
}
lck_mtx_unlock(bpf_mlock);
}
static int
filt_bpfread(struct knote *kn, long hint)
{
#pragma unused(hint)
struct bpf_d *d = (struct bpf_d *)knote_kn_hook_get_raw(kn);
return filt_bpfread_common(kn, NULL, d);
}
static int
filt_bpftouch(struct knote *kn, struct kevent_qos_s *kev)
{
struct bpf_d *d = (struct bpf_d *)knote_kn_hook_get_raw(kn);
int res;
lck_mtx_lock(bpf_mlock);
/* save off the lowat threshold and flag */
kn->kn_sdata = kev->data;
kn->kn_sfflags = kev->fflags;
/* output data will be re-generated here */
res = filt_bpfread_common(kn, NULL, d);
lck_mtx_unlock(bpf_mlock);
return res;
}
static int
filt_bpfprocess(struct knote *kn, struct kevent_qos_s *kev)
{
struct bpf_d *d = (struct bpf_d *)knote_kn_hook_get_raw(kn);
int res;
lck_mtx_lock(bpf_mlock);
res = filt_bpfread_common(kn, kev, d);
lck_mtx_unlock(bpf_mlock);
return res;
}
/*
* Copy data from an mbuf chain into a buffer. This code is derived
* from m_copydata in kern/uipc_mbuf.c.
*/
static void
bpf_mcopy(struct mbuf *m, void *dst_arg, size_t len, size_t offset)
{
u_int count;
u_char *dst;
dst = dst_arg;
while (offset >= m->m_len) {
offset -= m->m_len;
m = m->m_next;
if (m == NULL) {
panic("bpf_mcopy");
}
continue;
}
while (len > 0) {
if (m == NULL) {
panic("bpf_mcopy");
}
count = MIN(m->m_len - (u_int)offset, (u_int)len);
bcopy((u_char *)mbuf_data(m) + offset, dst, count);
m = m->m_next;
dst += count;
len -= count;
offset = 0;
}
}
static inline void
bpf_tap_imp(
ifnet_t ifp,
u_int32_t dlt,
struct bpf_packet *bpf_pkt,
int outbound)
{
struct bpf_d *d;
u_int slen;
struct bpf_if *bp;
/*
* It's possible that we get here after the bpf descriptor has been
* detached from the interface; in such a case we simply return.
* Lock ordering is important since we can be called asynchronously
* (from IOKit) to process an inbound packet; when that happens
* we would have been holding its "gateLock" and will be acquiring
* "bpf_mlock" upon entering this routine. Due to that, we release
* "bpf_mlock" prior to calling ifnet_set_promiscuous (which will
* acquire "gateLock" in the IOKit), in order to avoid a deadlock
* when a ifnet_set_promiscuous request simultaneously collides with
* an inbound packet being passed into the tap callback.
*/
lck_mtx_lock(bpf_mlock);
if (ifp->if_bpf == NULL) {
lck_mtx_unlock(bpf_mlock);
return;
}
for (bp = ifp->if_bpf; bp != NULL; bp = bp->bif_next) {
if (bp->bif_ifp != ifp) {
/* wrong interface */
bp = NULL;
break;
}
if (dlt == 0 || bp->bif_dlt == dlt) {
/* tapping default DLT or DLT matches */
break;
}
}
if (bp == NULL) {
goto done;
}
for (d = bp->bif_dlist; d != NULL; d = d->bd_next) {
struct bpf_packet *bpf_pkt_saved = bpf_pkt;
struct bpf_packet bpf_pkt_tmp = {};
struct pktap_header_buffer bpfp_header_tmp = {};
if (outbound && (d->bd_direction & BPF_D_OUT) == 0) {
continue;
}
if (!outbound && (d->bd_direction & BPF_D_IN) == 0) {
continue;
}
++d->bd_rcount;
slen = bpf_filter(d->bd_filter, (u_char *)bpf_pkt,
(u_int)bpf_pkt->bpfp_total_length, 0);
if (slen != 0) {
if (bp->bif_ifp->if_type == IFT_PKTAP &&
bp->bif_dlt == DLT_PKTAP) {
if (d->bd_flags & BPF_TRUNCATE) {
slen = min(slen, get_pkt_trunc_len(bpf_pkt));
}
/*
* Need to copy the bpf_pkt because the conversion
* to v2 pktap header modifies the content of the
* bpfp_header
*/
if ((d->bd_flags & BPF_PKTHDRV2) &&
bpf_pkt->bpfp_header_length <= sizeof(bpfp_header_tmp)) {
bpf_pkt_tmp = *bpf_pkt;
bpf_pkt = &bpf_pkt_tmp;
memcpy(&bpfp_header_tmp, bpf_pkt->bpfp_header,
bpf_pkt->bpfp_header_length);
bpf_pkt->bpfp_header = &bpfp_header_tmp;
convert_to_pktap_header_to_v2(bpf_pkt,
!!(d->bd_flags & BPF_TRUNCATE));
}
}
++d->bd_fcount;
catchpacket(d, bpf_pkt, slen, outbound);
}
bpf_pkt = bpf_pkt_saved;
}
done:
lck_mtx_unlock(bpf_mlock);
}
static inline void
bpf_tap_mbuf(
ifnet_t ifp,
u_int32_t dlt,
mbuf_t m,
void* hdr,
size_t hlen,
int outbound)
{
struct bpf_packet bpf_pkt;
struct mbuf *m0;
if (ifp->if_bpf == NULL) {
/* quickly check without taking lock */
return;
}
bpf_pkt.bpfp_type = BPF_PACKET_TYPE_MBUF;
bpf_pkt.bpfp_mbuf = m;
bpf_pkt.bpfp_total_length = 0;
for (m0 = m; m0 != NULL; m0 = m0->m_next) {
bpf_pkt.bpfp_total_length += m0->m_len;
}
bpf_pkt.bpfp_header = hdr;
if (hdr != NULL) {
bpf_pkt.bpfp_total_length += hlen;
bpf_pkt.bpfp_header_length = hlen;
} else {
bpf_pkt.bpfp_header_length = 0;
}
bpf_tap_imp(ifp, dlt, &bpf_pkt, outbound);
}
void
bpf_tap_out(
ifnet_t ifp,
u_int32_t dlt,
mbuf_t m,
void* hdr,
size_t hlen)
{
bpf_tap_mbuf(ifp, dlt, m, hdr, hlen, 1);
}
void
bpf_tap_in(
ifnet_t ifp,
u_int32_t dlt,
mbuf_t m,
void* hdr,
size_t hlen)
{
bpf_tap_mbuf(ifp, dlt, m, hdr, hlen, 0);
}
/* Callback registered with Ethernet driver. */
static int
bpf_tap_callback(struct ifnet *ifp, struct mbuf *m)
{
bpf_tap_mbuf(ifp, 0, m, NULL, 0, mbuf_pkthdr_rcvif(m) == NULL);
return 0;
}
#if SKYWALK
#include <skywalk/os_skywalk_private.h>
static void
bpf_pktcopy(kern_packet_t pkt, void *dst_arg, size_t len, size_t offset)
{
kern_buflet_t buflet = NULL;
size_t count;
u_char *dst;
dst = dst_arg;
while (len > 0) {
uint8_t *addr;
u_int32_t buflet_length;
buflet = kern_packet_get_next_buflet(pkt, buflet);
VERIFY(buflet != NULL);
addr = kern_buflet_get_data_address(buflet);
VERIFY(addr != NULL);
addr += kern_buflet_get_data_offset(buflet);
buflet_length = kern_buflet_get_data_length(buflet);
if (offset >= buflet_length) {
offset -= buflet_length;
continue;
}
count = MIN(buflet_length - offset, len);
bcopy((void *)(addr + offset), (void *)dst, count);
dst += count;
len -= count;
offset = 0;
}
}
static inline void
bpf_tap_packet(
ifnet_t ifp,
u_int32_t dlt,
kern_packet_t pkt,
void* hdr,
size_t hlen,
int outbound)
{
struct bpf_packet bpf_pkt;
struct mbuf * m;
if (ifp->if_bpf == NULL) {
/* quickly check without taking lock */
return;
}
m = kern_packet_get_mbuf(pkt);
if (m != NULL) {
bpf_pkt.bpfp_type = BPF_PACKET_TYPE_MBUF;
bpf_pkt.bpfp_mbuf = m;
bpf_pkt.bpfp_total_length = m_length(m);
} else {
bpf_pkt.bpfp_type = BPF_PACKET_TYPE_PKT;
bpf_pkt.bpfp_pkt = pkt;
bpf_pkt.bpfp_total_length = kern_packet_get_data_length(pkt);
}
bpf_pkt.bpfp_header = hdr;
bpf_pkt.bpfp_header_length = hlen;
if (hlen != 0) {
bpf_pkt.bpfp_total_length += hlen;
}
bpf_tap_imp(ifp, dlt, &bpf_pkt, outbound);
}
void
bpf_tap_packet_out(
ifnet_t ifp,
u_int32_t dlt,
kern_packet_t pkt,
void* hdr,
size_t hlen)
{
bpf_tap_packet(ifp, dlt, pkt, hdr, hlen, 1);
}
void
bpf_tap_packet_in(
ifnet_t ifp,
u_int32_t dlt,
kern_packet_t pkt,
void* hdr,
size_t hlen)
{
bpf_tap_packet(ifp, dlt, pkt, hdr, hlen, 0);
}
#endif /* SKYWALK */
static errno_t
bpf_copydata(struct bpf_packet *pkt, size_t off, size_t len, void* out_data)
{
errno_t err = 0;
if (pkt->bpfp_type == BPF_PACKET_TYPE_MBUF) {
err = mbuf_copydata(pkt->bpfp_mbuf, off, len, out_data);
#if SKYWALK
} else if (pkt->bpfp_type == BPF_PACKET_TYPE_PKT) {
err = kern_packet_copy_bytes(pkt->bpfp_pkt, off, len, out_data);
#endif /* SKYWALK */
} else {
err = EINVAL;
}
return err;
}
static void
copy_bpf_packet_offset(struct bpf_packet * pkt, void * dst, size_t len, size_t offset)
{
/* copy the optional header */
if (offset < pkt->bpfp_header_length) {
size_t count = MIN(len, pkt->bpfp_header_length - offset);
caddr_t src = (caddr_t)pkt->bpfp_header;
bcopy(src + offset, dst, count);
len -= count;
dst = (void *)((uintptr_t)dst + count);
offset = 0;
} else {
offset -= pkt->bpfp_header_length;
}
if (len == 0) {
/* nothing past the header */
return;
}
/* copy the packet */
switch (pkt->bpfp_type) {
case BPF_PACKET_TYPE_MBUF:
bpf_mcopy(pkt->bpfp_mbuf, dst, len, offset);
break;
#if SKYWALK
case BPF_PACKET_TYPE_PKT:
bpf_pktcopy(pkt->bpfp_pkt, dst, len, offset);
break;
#endif /* SKYWALK */
default:
break;
}
}
static void
copy_bpf_packet(struct bpf_packet * pkt, void * dst, size_t len)
{
copy_bpf_packet_offset(pkt, dst, len, 0);
}
static uint32_t
get_esp_trunc_len(__unused struct bpf_packet *pkt, __unused uint32_t off,
const uint32_t remaining_caplen)
{
/*
* For some reason tcpdump expects to have one byte beyond the ESP header
*/
uint32_t trunc_len = ESP_HDR_SIZE + 1;
if (trunc_len > remaining_caplen) {
return remaining_caplen;
}
return trunc_len;
}
static uint32_t
get_isakmp_trunc_len(__unused struct bpf_packet *pkt, __unused uint32_t off,
const uint32_t remaining_caplen)
{
/*
* Include the payload generic header
*/
uint32_t trunc_len = ISAKMP_HDR_SIZE;
if (trunc_len > remaining_caplen) {
return remaining_caplen;
}
return trunc_len;
}
static uint32_t
get_isakmp_natt_trunc_len(struct bpf_packet *pkt, uint32_t off,
const uint32_t remaining_caplen)
{
int err = 0;
uint32_t trunc_len = 0;
char payload[remaining_caplen];
err = bpf_copydata(pkt, off, remaining_caplen, payload);
if (err != 0) {
return remaining_caplen;
}
/*
* They are three cases:
* - IKE: payload start with 4 bytes header set to zero before ISAKMP header
* - keep alive: 1 byte payload
* - otherwise it's ESP
*/
if (remaining_caplen >= 4 &&
payload[0] == 0 && payload[1] == 0 &&
payload[2] == 0 && payload[3] == 0) {
trunc_len = 4 + get_isakmp_trunc_len(pkt, off + 4, remaining_caplen - 4);
} else if (remaining_caplen == 1) {
trunc_len = 1;
} else {
trunc_len = get_esp_trunc_len(pkt, off, remaining_caplen);
}
if (trunc_len > remaining_caplen) {
return remaining_caplen;
}
return trunc_len;
}
static uint32_t
get_udp_trunc_len(struct bpf_packet *pkt, uint32_t off, const uint32_t remaining_caplen)
{
int err = 0;
uint32_t trunc_len = sizeof(struct udphdr); /* By default no UDP payload */
if (trunc_len >= remaining_caplen) {
return remaining_caplen;
}
struct udphdr udphdr;
err = bpf_copydata(pkt, off, sizeof(struct udphdr), &udphdr);
if (err != 0) {
return remaining_caplen;
}
u_short sport, dport;
sport = EXTRACT_SHORT(&udphdr.uh_sport);
dport = EXTRACT_SHORT(&udphdr.uh_dport);
if (dport == PORT_DNS || sport == PORT_DNS) {
/*
* Full UDP payload for DNS
*/
trunc_len = remaining_caplen;
} else if ((sport == PORT_BOOTPS && dport == PORT_BOOTPC) ||
(sport == PORT_BOOTPC && dport == PORT_BOOTPS)) {
/*
* Full UDP payload for BOOTP and DHCP
*/
trunc_len = remaining_caplen;
} else if (dport == PORT_ISAKMP && sport == PORT_ISAKMP) {
/*
* Return the ISAKMP header
*/
trunc_len += get_isakmp_trunc_len(pkt, off + sizeof(struct udphdr),
remaining_caplen - sizeof(struct udphdr));
} else if (dport == PORT_ISAKMP_NATT && sport == PORT_ISAKMP_NATT) {
trunc_len += get_isakmp_natt_trunc_len(pkt, off + sizeof(struct udphdr),
remaining_caplen - sizeof(struct udphdr));
}
if (trunc_len >= remaining_caplen) {
return remaining_caplen;
}
return trunc_len;
}
static uint32_t
get_tcp_trunc_len(struct bpf_packet *pkt, uint32_t off, const uint32_t remaining_caplen)
{
int err = 0;
uint32_t trunc_len = sizeof(struct tcphdr); /* By default no TCP payload */
if (trunc_len >= remaining_caplen) {
return remaining_caplen;
}
struct tcphdr tcphdr;
err = bpf_copydata(pkt, off, sizeof(struct tcphdr), &tcphdr);
if (err != 0) {
return remaining_caplen;
}
u_short sport, dport;
sport = EXTRACT_SHORT(&tcphdr.th_sport);
dport = EXTRACT_SHORT(&tcphdr.th_dport);
if (dport == PORT_DNS || sport == PORT_DNS) {
/*
* Full TCP payload for DNS
*/
trunc_len = remaining_caplen;
} else {
trunc_len = (uint16_t)(tcphdr.th_off << 2);
}
if (trunc_len >= remaining_caplen) {
return remaining_caplen;
}
return trunc_len;
}
static uint32_t
get_proto_trunc_len(uint8_t proto, struct bpf_packet *pkt, uint32_t off, const uint32_t remaining_caplen)
{
uint32_t trunc_len;
switch (proto) {
case IPPROTO_ICMP: {
/*
* Full IMCP payload
*/
trunc_len = remaining_caplen;
break;
}
case IPPROTO_ICMPV6: {
/*
* Full IMCPV6 payload
*/
trunc_len = remaining_caplen;
break;
}
case IPPROTO_IGMP: {
/*
* Full IGMP payload
*/
trunc_len = remaining_caplen;
break;
}
case IPPROTO_UDP: {
trunc_len = get_udp_trunc_len(pkt, off, remaining_caplen);
break;
}
case IPPROTO_TCP: {
trunc_len = get_tcp_trunc_len(pkt, off, remaining_caplen);
break;
}
case IPPROTO_ESP: {
trunc_len = get_esp_trunc_len(pkt, off, remaining_caplen);
break;
}
default: {
/*
* By default we only include the IP header
*/
trunc_len = 0;
break;
}
}
if (trunc_len >= remaining_caplen) {
return remaining_caplen;
}
return trunc_len;
}
static uint32_t
get_ip_trunc_len(struct bpf_packet *pkt, uint32_t off, const uint32_t remaining_caplen)
{
int err = 0;
uint32_t iplen = sizeof(struct ip);
if (iplen >= remaining_caplen) {
return remaining_caplen;
}
struct ip iphdr;
err = bpf_copydata(pkt, off, sizeof(struct ip), &iphdr);
if (err != 0) {
return remaining_caplen;
}
uint8_t proto = 0;
iplen = (uint16_t)(iphdr.ip_hl << 2);
if (iplen >= remaining_caplen) {
return remaining_caplen;
}
proto = iphdr.ip_p;
iplen += get_proto_trunc_len(proto, pkt, off + iplen, remaining_caplen - iplen);
if (iplen >= remaining_caplen) {
return remaining_caplen;
}
return iplen;
}
static uint32_t
get_ip6_trunc_len(struct bpf_packet *pkt, uint32_t off, const uint32_t remaining_caplen)
{
int err = 0;
uint32_t iplen = sizeof(struct ip6_hdr);
if (iplen >= remaining_caplen) {
return remaining_caplen;
}
struct ip6_hdr ip6hdr;
err = bpf_copydata(pkt, off, sizeof(struct ip6_hdr), &ip6hdr);
if (err != 0) {
return remaining_caplen;
}
uint8_t proto = 0;
/*
* TBD: process the extension headers
*/
proto = ip6hdr.ip6_nxt;
iplen += get_proto_trunc_len(proto, pkt, off + iplen, remaining_caplen - iplen);
if (iplen >= remaining_caplen) {
return remaining_caplen;
}
return iplen;
}
static uint32_t
get_ether_trunc_len(struct bpf_packet *pkt, uint32_t off, const uint32_t remaining_caplen)
{
int err = 0;
uint32_t ethlen = sizeof(struct ether_header);
if (ethlen >= remaining_caplen) {
return remaining_caplen;
}
struct ether_header eh = {};
err = bpf_copydata(pkt, off, sizeof(struct ether_header), &eh);
if (err != 0) {
return remaining_caplen;
}
u_short type = EXTRACT_SHORT(&eh.ether_type);
/* Include full ARP */
if (type == ETHERTYPE_ARP) {
ethlen = remaining_caplen;
} else if (type == ETHERTYPE_IP) {
ethlen += get_ip_trunc_len(pkt, off + sizeof(struct ether_header),
remaining_caplen - ethlen);
} else if (type == ETHERTYPE_IPV6) {
ethlen += get_ip6_trunc_len(pkt, off + sizeof(struct ether_header),
remaining_caplen - ethlen);
} else {
ethlen = MIN(BPF_MIN_PKT_SIZE, remaining_caplen);
}
return ethlen;
}
static uint32_t
get_pkt_trunc_len(struct bpf_packet *pkt)
{
struct pktap_header *pktap = (struct pktap_header *) (pkt->bpfp_header);
uint32_t in_pkt_len = 0;
uint32_t out_pkt_len = 0;
uint32_t tlen = 0;
uint32_t pre_adjust; // L2 header not in mbuf or kern_packet
// bpfp_total_length must contain the BPF packet header
assert3u(pkt->bpfp_total_length, >=, pkt->bpfp_header_length);
// The BPF packet header must contain the pktap header
assert3u(pkt->bpfp_header_length, >=, pktap->pth_length);
// The pre frame length (L2 header) must be contained in the packet
assert3u(pkt->bpfp_total_length, >=, pktap->pth_length + pktap->pth_frame_pre_length);
/*
* pktap->pth_frame_pre_length is the L2 header length and accounts
* for both L2 header in the packet payload and pre_adjust.
*
* pre_adjust represents an adjustment for a pseudo L2 header that is not
* part of packet payload -- not in the mbuf or kern_packet -- and comes
* just after the pktap header.
*
* pktap->pth_length is the size of the pktap header (exclude pre_adjust)
*
* pkt->bpfp_header_length is (pktap->pth_length + pre_adjust)
*/
pre_adjust = (uint32_t)(pkt->bpfp_header_length - pktap->pth_length);
if (pktap->pth_iftype == IFT_ETHER) {
/*
* We need to parse the Ethernet header to find the network layer
* protocol
*/
in_pkt_len = (uint32_t)(pkt->bpfp_total_length - pktap->pth_length - pre_adjust);
out_pkt_len = get_ether_trunc_len(pkt, 0, in_pkt_len);
tlen = pktap->pth_length + pre_adjust + out_pkt_len;
} else {
/*
* For other interface types, we only know to parse IPv4 and IPv6.
*
* To get to the beginning of the IPv4 or IPv6 packet, we need to to skip
* over the L2 header that is the actual packet payload (mbuf or kern_packet)
*/
uint32_t off; // offset past the L2 header in the actual packet payload
off = pktap->pth_frame_pre_length - pre_adjust;
in_pkt_len = (uint32_t)(pkt->bpfp_total_length - pktap->pth_length - pktap->pth_frame_pre_length);
if (pktap->pth_protocol_family == AF_INET) {
out_pkt_len = get_ip_trunc_len(pkt, off, in_pkt_len);
} else if (pktap->pth_protocol_family == AF_INET6) {
out_pkt_len = get_ip6_trunc_len(pkt, off, in_pkt_len);
} else {
out_pkt_len = MIN(BPF_MIN_PKT_SIZE, in_pkt_len);
}
tlen = pktap->pth_length + pktap->pth_frame_pre_length + out_pkt_len;
}
// Verify we do not overflow the buffer
if (__improbable(tlen > pkt->bpfp_total_length)) {
bool do_panic = bpf_debug != 0 ? true : false;
#if DEBUG
do_panic = true;
#endif /* DEBUG */
if (do_panic) {
panic("%s:%d tlen %u > bpfp_total_length %lu bpfp_header_length %lu pth_frame_pre_length %u pre_adjust %u in_pkt_len %u out_pkt_len %u",
__func__, __LINE__,
tlen, pkt->bpfp_total_length, pkt->bpfp_header_length, pktap->pth_frame_pre_length, pre_adjust, in_pkt_len, out_pkt_len);
} else {
os_log(OS_LOG_DEFAULT,
"%s:%d tlen %u > bpfp_total_length %lu bpfp_header_length %lu pth_frame_pre_length %u pre_adjust %u in_pkt_len %u out_pkt_len %u",
__func__, __LINE__,
tlen, pkt->bpfp_total_length, pkt->bpfp_header_length, pktap->pth_frame_pre_length, pre_adjust, in_pkt_len, out_pkt_len);
}
bpf_trunc_overflow += 1;
tlen = (uint32_t)pkt->bpfp_total_length;
}
return tlen;
}
static uint8_t
get_common_prefix_size(const void *a, const void *b, uint8_t max_bytes)
{
uint8_t max_words = max_bytes >> 2;
const uint32_t *x = (const uint32_t *)a;
const uint32_t *y = (const uint32_t *)b;
uint8_t i;
for (i = 0; i < max_words; i++) {
if (x[i] != y[i]) {
break;
}
}
return (uint8_t)(i << 2);
}
/*
* 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.
*/
static void
catchpacket(struct bpf_d *d, struct bpf_packet * pkt,
u_int snaplen, int outbound)
{
struct bpf_hdr *hp;
struct bpf_hdr_ext *ehp;
uint32_t totlen, curlen;
uint32_t hdrlen, caplen;
int do_wakeup = 0;
u_char *payload;
struct timeval tv;
hdrlen = (d->bd_flags & BPF_EXTENDED_HDR) ? d->bd_bif->bif_exthdrlen :
(d->bd_flags & BPF_COMP_REQ) ? d->bd_bif->bif_comphdrlen:
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, (int)pkt->bpfp_total_length);
if (totlen > d->bd_bufsize) {
totlen = d->bd_bufsize;
}
if (hdrlen > totlen) {
return;
}
/*
* 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.
*
* We cannot rotate buffers if a read is in progress
* so drop the packet
*/
if (d->bd_hbuf_read) {
++d->bd_dcount;
return;
}
if (d->bd_fbuf == NULL) {
if (d->bd_headdrop == 0) {
/*
* We haven't completed the previous read yet,
* so drop the packet.
*/
++d->bd_dcount;
return;
}
/*
* Drop the hold buffer as it contains older packets
*/
d->bd_dcount += d->bd_hcnt;
d->bd_fbuf = d->bd_hbuf;
ROTATE_BUFFERS(d);
} else {
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.
*/
microtime(&tv);
if (d->bd_flags & BPF_EXTENDED_HDR) {
ehp = (struct bpf_hdr_ext *)(void *)(d->bd_sbuf + curlen);
memset(ehp, 0, sizeof(*ehp));
ehp->bh_tstamp.tv_sec = (int)tv.tv_sec;
ehp->bh_tstamp.tv_usec = tv.tv_usec;
ehp->bh_datalen = (bpf_u_int32)pkt->bpfp_total_length;
ehp->bh_hdrlen = (u_short)hdrlen;
caplen = ehp->bh_caplen = totlen - hdrlen;
payload = (u_char *)ehp + hdrlen;
if (outbound) {
ehp->bh_flags |= BPF_HDR_EXT_FLAGS_DIR_OUT;
} else {
ehp->bh_flags |= BPF_HDR_EXT_FLAGS_DIR_IN;
}
if (pkt->bpfp_type == BPF_PACKET_TYPE_MBUF) {
struct mbuf *m = pkt->bpfp_mbuf;
if (outbound) {
/* only do lookups on non-raw INPCB */
if ((m->m_pkthdr.pkt_flags & (PKTF_FLOW_ID |
PKTF_FLOW_LOCALSRC | PKTF_FLOW_RAWSOCK)) ==
(PKTF_FLOW_ID | PKTF_FLOW_LOCALSRC) &&
m->m_pkthdr.pkt_flowsrc == FLOWSRC_INPCB) {
ehp->bh_flowid = m->m_pkthdr.pkt_flowid;
if (m->m_pkthdr.pkt_proto == IPPROTO_TCP) {
ehp->bh_flags |= BPF_HDR_EXT_FLAGS_TCP;
} else if (m->m_pkthdr.pkt_proto == IPPROTO_UDP) {
ehp->bh_flags |= BPF_HDR_EXT_FLAGS_UDP;
}
}
ehp->bh_svc = so_svc2tc(m->m_pkthdr.pkt_svc);
if (m->m_pkthdr.pkt_flags & PKTF_TCP_REXMT) {
ehp->bh_pktflags |= BPF_PKTFLAGS_TCP_REXMT;
}
if (m->m_pkthdr.pkt_flags & PKTF_START_SEQ) {
ehp->bh_pktflags |= BPF_PKTFLAGS_START_SEQ;
}
if (m->m_pkthdr.pkt_flags & PKTF_LAST_PKT) {
ehp->bh_pktflags |= BPF_PKTFLAGS_LAST_PKT;
}
if (m->m_pkthdr.pkt_flags & PKTF_VALID_UNSENT_DATA) {
ehp->bh_unsent_bytes =
m->m_pkthdr.bufstatus_if;
ehp->bh_unsent_snd =
m->m_pkthdr.bufstatus_sndbuf;
}
} else {
if (m->m_pkthdr.pkt_flags & PKTF_WAKE_PKT) {
ehp->bh_pktflags |= BPF_PKTFLAGS_WAKE_PKT;
}
}
#if SKYWALK
} else {
kern_packet_t kern_pkt = pkt->bpfp_pkt;
packet_flowid_t flowid = 0;
if (outbound) {
/*
* Note: pp_init() asserts that kern_packet_svc_class_t is equivalent
* to mbuf_svc_class_t
*/
ehp->bh_svc = so_svc2tc((mbuf_svc_class_t)kern_packet_get_service_class(kern_pkt));
if (kern_packet_get_transport_retransmit(kern_pkt)) {
ehp->bh_pktflags |= BPF_PKTFLAGS_TCP_REXMT;
}
if (kern_packet_get_transport_last_packet(kern_pkt)) {
ehp->bh_pktflags |= BPF_PKTFLAGS_LAST_PKT;
}
} else {
if (kern_packet_get_wake_flag(kern_pkt)) {
ehp->bh_pktflags |= BPF_PKTFLAGS_WAKE_PKT;
}
}
ehp->bh_trace_tag = kern_packet_get_trace_tag(kern_pkt);
if (kern_packet_get_flowid(kern_pkt, &flowid) == 0) {
ehp->bh_flowid = flowid;
}
#endif /* SKYWALK */
}
} else {
hp = (struct bpf_hdr *)(void *)(d->bd_sbuf + curlen);
memset(hp, 0, BPF_WORDALIGN(sizeof(*hp)));
hp->bh_tstamp.tv_sec = (int)tv.tv_sec;
hp->bh_tstamp.tv_usec = tv.tv_usec;
hp->bh_datalen = (bpf_u_int32)pkt->bpfp_total_length;
hp->bh_hdrlen = (u_short)hdrlen;
caplen = hp->bh_caplen = totlen - hdrlen;
payload = (u_char *)hp + hdrlen;
}
if (d->bd_flags & BPF_COMP_REQ) {
uint8_t common_prefix_size = 0;
uint8_t copy_len = MIN((uint8_t)caplen, BPF_HDR_COMP_LEN_MAX);
copy_bpf_packet(pkt, d->bd_prev_fbuf, copy_len);
if (d->bd_prev_slen != 0) {
common_prefix_size = get_common_prefix_size(d->bd_prev_fbuf,
d->bd_prev_sbuf, MIN(copy_len, d->bd_prev_slen));
}
if (d->bd_flags & BPF_COMP_ENABLED) {
assert3u(caplen, >=, common_prefix_size);
copy_bpf_packet_offset(pkt, payload, caplen - common_prefix_size,
common_prefix_size);
d->bd_slen = curlen + totlen - common_prefix_size;
} else {
copy_bpf_packet(pkt, payload, caplen);
d->bd_slen = curlen + totlen;
}
/*
* Update the caplen only if compression is enabled -- the caller
* must pay attention to bpf_hdr_comp_enable
*/
if (d->bd_flags & BPF_EXTENDED_HDR) {
ehp->bh_complen = common_prefix_size;
if (d->bd_flags & BPF_COMP_ENABLED) {
ehp->bh_caplen -= common_prefix_size;
}
} else {
struct bpf_comp_hdr *hcp;
hcp = (struct bpf_comp_hdr *)(void *)(d->bd_sbuf + curlen);
hcp->bh_complen = common_prefix_size;
if (d->bd_flags & BPF_COMP_ENABLED) {
hcp->bh_caplen -= common_prefix_size;
}
}
if (common_prefix_size > 0) {
d->bd_bcs.bcs_total_compressed_prefix_size += common_prefix_size;
if (common_prefix_size > d->bd_bcs.bcs_max_compressed_prefix_size) {
d->bd_bcs.bcs_max_compressed_prefix_size = common_prefix_size;
}
d->bd_bcs.bcs_count_compressed_prefix += 1;
} else {
d->bd_bcs.bcs_count_no_common_prefix += 1;
}
/* The current compression buffer becomes the previous one */
caddr_t tmp = d->bd_prev_sbuf;
d->bd_prev_sbuf = d->bd_prev_fbuf;
d->bd_prev_slen = copy_len;
d->bd_prev_fbuf = tmp;
} else {
/*
* Copy the packet data into the store buffer and update its length.
*/
copy_bpf_packet(pkt, payload, caplen);
d->bd_slen = curlen + totlen;
}
d->bd_scnt += 1;
d->bd_bcs.bcs_total_hdr_size += pkt->bpfp_header_length;
d->bd_bcs.bcs_total_size += caplen;
if (do_wakeup) {
bpf_wakeup(d);
}
}
static void
bpf_freebufs(struct bpf_d *d)
{
if (d->bd_sbuf != NULL) {
kfree_data_addr(d->bd_sbuf);
}
if (d->bd_hbuf != NULL) {
kfree_data_addr(d->bd_hbuf);
}
if (d->bd_fbuf != NULL) {
kfree_data_addr(d->bd_fbuf);
}
if (d->bd_prev_sbuf != NULL) {
kfree_data_addr(d->bd_prev_sbuf);
}
if (d->bd_prev_fbuf != NULL) {
kfree_data_addr(d->bd_prev_fbuf);
}
}
/*
* Initialize all nonzero fields of a descriptor.
*/
static int
bpf_allocbufs(struct bpf_d *d)
{
bpf_freebufs(d);
d->bd_fbuf = (caddr_t) kalloc_data(d->bd_bufsize, Z_WAITOK | Z_ZERO);
if (d->bd_fbuf == NULL) {
goto nobufs;
}
d->bd_sbuf = (caddr_t) kalloc_data(d->bd_bufsize, Z_WAITOK | Z_ZERO);
if (d->bd_sbuf == NULL) {
goto nobufs;
}
d->bd_slen = 0;
d->bd_hlen = 0;
d->bd_scnt = 0;
d->bd_hcnt = 0;
d->bd_prev_slen = 0;
if (d->bd_flags & BPF_COMP_REQ) {
d->bd_prev_sbuf = (caddr_t) kalloc_data(BPF_HDR_COMP_LEN_MAX, Z_WAITOK | Z_ZERO);
if (d->bd_prev_sbuf == NULL) {
goto nobufs;
}
d->bd_prev_fbuf = (caddr_t) kalloc_data(BPF_HDR_COMP_LEN_MAX, Z_WAITOK | Z_ZERO);
if (d->bd_prev_fbuf == NULL) {
goto nobufs;
}
}
return 0;
nobufs:
bpf_freebufs(d);
return ENOMEM;
}
/*
* 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_hbuf_read || d->bd_hbuf_write) {
panic("bpf buffer freed during read/write");
}
bpf_freebufs(d);
if (d->bd_filter) {
kfree_data_addr(d->bd_filter);
}
}
/*
* 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(struct ifnet *ifp, u_int dlt, u_int hdrlen)
{
bpf_attach(ifp, dlt, hdrlen, NULL, NULL);
}
errno_t
bpf_attach(
ifnet_t ifp,
u_int32_t dlt,
u_int32_t hdrlen,
bpf_send_func send,
bpf_tap_func tap)
{
struct bpf_if *bp;
struct bpf_if *bp_new;
struct bpf_if *bp_before_first = NULL;
struct bpf_if *bp_first = NULL;
struct bpf_if *bp_last = NULL;
boolean_t found;
/*
* Z_NOFAIL will cause a panic if the allocation fails
*/
bp_new = kalloc_type(struct bpf_if, Z_WAITOK | Z_NOFAIL | Z_ZERO);
lck_mtx_lock(bpf_mlock);
/*
* Check if this interface/dlt is already attached. Remember the
* first and last attachment for this interface, as well as the
* element before the first attachment.
*/
found = FALSE;
for (bp = bpf_iflist; bp != NULL; bp = bp->bif_next) {
if (bp->bif_ifp != ifp) {
if (bp_first != NULL) {
/* no more elements for this interface */
break;
}
bp_before_first = bp;
} else {
if (bp->bif_dlt == dlt) {
found = TRUE;
break;
}
if (bp_first == NULL) {
bp_first = bp;
}
bp_last = bp;
}
}
if (found) {
lck_mtx_unlock(bpf_mlock);
os_log_error(OS_LOG_DEFAULT,
"bpfattach - %s with dlt %d is already attached",
if_name(ifp), dlt);
kfree_type(struct bpf_if, bp_new);
return EEXIST;
}
bp_new->bif_ifp = ifp;
bp_new->bif_dlt = dlt;
bp_new->bif_send = send;
bp_new->bif_tap = tap;
if (bp_first == NULL) {
/* No other entries for this ifp */
bp_new->bif_next = bpf_iflist;
bpf_iflist = bp_new;
} else {
if (ifnet_type(ifp) == IFT_ETHER && dlt == DLT_EN10MB) {
/* Make this the first entry for this interface */
if (bp_before_first != NULL) {
/* point the previous to us */
bp_before_first->bif_next = bp_new;
} else {
/* we're the new head */
bpf_iflist = bp_new;
}
bp_new->bif_next = bp_first;
} else {
/* Add this after the last entry for this interface */
bp_new->bif_next = bp_last->bif_next;
bp_last->bif_next = bp_new;
}
}
/*
* 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_new->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
bp_new->bif_exthdrlen = BPF_WORDALIGN(hdrlen +
sizeof(struct bpf_hdr_ext)) - hdrlen;
bp_new->bif_comphdrlen = BPF_WORDALIGN(hdrlen +
sizeof(struct bpf_comp_hdr)) - hdrlen;
/* Take a reference on the interface */
ifnet_reference(ifp);
lck_mtx_unlock(bpf_mlock);
return 0;
}
/*
* 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, *bp_prev, *bp_next;
struct bpf_d *d;
if (bpf_debug != 0) {
os_log(OS_LOG_DEFAULT, "%s: %s", __func__, if_name(ifp));
}
lck_mtx_lock(bpf_mlock);
/*
* Build the list of devices attached to that interface
* that we need to free while keeping the lock to maintain
* the integrity of the interface list
*/
bp_prev = NULL;
for (bp = bpf_iflist; bp != NULL; bp = bp_next) {
bp_next = bp->bif_next;
if (ifp != bp->bif_ifp) {
bp_prev = bp;
continue;
}
/* Unlink from the interface list */
if (bp_prev) {
bp_prev->bif_next = bp->bif_next;
} else {
bpf_iflist = bp->bif_next;
}
/* Detach the devices attached to the interface */
while ((d = bp->bif_dlist) != NULL) {
/*
* Take an extra reference to prevent the device
* from being freed when bpf_detachd() releases
* the reference for the interface list
*/
bpf_acquire_d(d);
/*
* Wait for active read and writes to complete
*/
while (d->bd_hbuf_read || d->bd_hbuf_write) {
msleep((caddr_t)d, bpf_mlock, PRINET, "bpfdetach", NULL);
}
bpf_detachd(d);
bpf_wakeup(d);
bpf_release_d(d);
}
ifnet_release(ifp);
}
lck_mtx_unlock(bpf_mlock);
}
void
bpf_init(__unused void *unused)
{
int maj;
/* bpf_comp_hdr is an overlay of bpf_hdr */
_CASSERT(BPF_WORDALIGN(sizeof(struct bpf_hdr)) ==
BPF_WORDALIGN(sizeof(struct bpf_comp_hdr)));
/* compression length must fits in a byte */
_CASSERT(BPF_HDR_COMP_LEN_MAX <= UCHAR_MAX );
(void) PE_parse_boot_argn("bpf_hdr_comp", &bpf_hdr_comp_enable,
sizeof(bpf_hdr_comp_enable));
if (bpf_devsw_installed == 0) {
bpf_devsw_installed = 1;
maj = cdevsw_add(CDEV_MAJOR, &bpf_cdevsw);
if (maj == -1) {
bpf_devsw_installed = 0;
os_log_error(OS_LOG_DEFAULT,
"bpf_init: failed to allocate a major number");
return;
}
for (int i = 0; i < NBPFILTER; i++) {
bpf_make_dev_t(maj);
}
}
}
static int
sysctl_bpf_maxbufsize SYSCTL_HANDLER_ARGS
{
#pragma unused(arg1, arg2)
int i, err;
i = bpf_maxbufsize;
err = sysctl_handle_int(oidp, &i, 0, req);
if (err != 0 || req->newptr == USER_ADDR_NULL) {
return err;
}
if (i < 0 || i > BPF_BUFSIZE_CAP) {
i = BPF_BUFSIZE_CAP;
}
bpf_maxbufsize = i;
return err;
}
static int
sysctl_bpf_bufsize_cap SYSCTL_HANDLER_ARGS
{
#pragma unused(arg1, arg2)
int i, err;
i = BPF_BUFSIZE_CAP;
err = sysctl_handle_int(oidp, &i, 0, req);
if (err != 0 || req->newptr == USER_ADDR_NULL) {
return err;
}
return err;
}
/*
* Fill filter statistics
*/
static void
bpfstats_fill_xbpf(struct xbpf_d *d, struct bpf_d *bd)
{
LCK_MTX_ASSERT(bpf_mlock, LCK_MTX_ASSERT_OWNED);
d->bd_structsize = sizeof(struct xbpf_d);
d->bd_promisc = bd->bd_promisc != 0 ? 1 : 0;
d->bd_immediate = d->bd_immediate != 0 ? 1 : 0;
d->bd_hdrcmplt = bd->bd_hdrcmplt != 0 ? 1 : 0;
d->bd_async = bd->bd_async != 0 ? 1 : 0;
d->bd_headdrop = bd->bd_headdrop != 0 ? 1 : 0;
d->bd_direction = (uint8_t)bd->bd_direction;
d->bh_compreq = bd->bd_flags & BPF_COMP_REQ ? 1 : 0;
d->bh_compenabled = bd->bd_flags & BPF_COMP_ENABLED ? 1 : 0;
d->bd_exthdr = bd->bd_flags & BPF_EXTENDED_HDR ? 1 : 0;
d->bd_trunc = bd->bd_flags & BPF_TRUNCATE ? 1 : 0;
d->bd_pkthdrv2 = bd->bd_flags & BPF_PKTHDRV2 ? 1 : 0;
d->bd_dev_minor = (uint8_t)bd->bd_dev_minor;
d->bd_sig = bd->bd_sig;
d->bd_rcount = bd->bd_rcount;
d->bd_dcount = bd->bd_dcount;
d->bd_fcount = bd->bd_fcount;
d->bd_wcount = bd->bd_wcount;
d->bd_wdcount = bd->bd_wdcount;
d->bd_slen = bd->bd_slen;
d->bd_hlen = bd->bd_hlen;
d->bd_bufsize = bd->bd_bufsize;
d->bd_pid = bd->bd_pid;
if (bd->bd_bif != NULL && bd->bd_bif->bif_ifp != NULL) {
strlcpy(d->bd_ifname,
bd->bd_bif->bif_ifp->if_xname, IFNAMSIZ);
}
d->bd_comp_count = bd->bd_bcs.bcs_count_compressed_prefix;
d->bd_comp_size = bd->bd_bcs.bcs_total_compressed_prefix_size;
d->bd_scnt = bd->bd_scnt;
d->bd_hcnt = bd->bd_hcnt;
d->bd_read_count = bd->bd_bcs.bcs_total_read;
d->bd_fsize = bd->bd_bcs.bcs_total_size;
}
/*
* Handle `netstat -B' stats request
*/
static int
sysctl_bpf_stats SYSCTL_HANDLER_ARGS
{
int error;
struct xbpf_d *xbdbuf;
unsigned int x_cnt;
vm_size_t buf_size;
if (req->oldptr == USER_ADDR_NULL) {
return SYSCTL_OUT(req, 0, nbpfilter * sizeof(struct xbpf_d));
}
if (nbpfilter == 0) {
return SYSCTL_OUT(req, 0, 0);
}
buf_size = req->oldlen;
if (buf_size > BPF_MAX_DEVICES * sizeof(struct xbpf_d)) {
buf_size = BPF_MAX_DEVICES * sizeof(struct xbpf_d);
}
xbdbuf = kalloc_data(buf_size, Z_WAITOK | Z_ZERO);
lck_mtx_lock(bpf_mlock);
if (buf_size < (nbpfilter * sizeof(struct xbpf_d))) {
lck_mtx_unlock(bpf_mlock);
kfree_data(xbdbuf, buf_size);
return ENOMEM;
}
x_cnt = 0;
unsigned int i;
for (i = 0; i < nbpfilter; i++) {
struct bpf_d *bd = bpf_dtab[i];
struct xbpf_d *xbd;
if (bd == NULL || bd == BPF_DEV_RESERVED ||
(bd->bd_flags & BPF_CLOSING) != 0) {
continue;
}
VERIFY(x_cnt < nbpfilter);
xbd = &xbdbuf[x_cnt++];
bpfstats_fill_xbpf(xbd, bd);
}
lck_mtx_unlock(bpf_mlock);
error = SYSCTL_OUT(req, xbdbuf, x_cnt * sizeof(struct xbpf_d));
kfree_data(xbdbuf, buf_size);
return error;
}
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