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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1990, 1991, 1993
* The Regents of the University of California. All rights reserved.
* Copyright (c) 2019 Andrey V. Elsukov <ae@FreeBSD.org>
* Copyright (c) 2025 Gleb Smirnoff <glebius@FreeBSD.org>
*
* 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. 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.
*/
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <net/bpf.h>
#include <net/bpfdesc.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_private.h>
#include <net/if_types.h>
#include <net/route.h>
/* We need to know all the ifnets we support. */
#include <net/if_dl.h>
#include <net/ethernet.h>
#include <net/firewire.h>
#include <net/if_pflog.h>
#include <net/if_pfsync.h>
#include <security/mac/mac_framework.h>
static int
bpf_ifnet_write(void *arg, struct mbuf *m, struct mbuf *mc, int flags)
{
struct ifnet *ifp = arg;
struct route ro = {};
struct sockaddr dst = {
.sa_family = AF_UNSPEC,
};
u_int hlen;
int error;
NET_EPOCH_ASSERT();
if (__predict_false((ifp->if_flags & IFF_UP) == 0)) {
m_freem(m);
m_freem(mc);
return (ENETDOWN);
}
switch (ifp->if_type) {
/* DLT_RAW */
case IFT_MBIM: /* umb(4) */
case IFT_OTHER: /* uhso(4), usie */
hlen = 0;
break;
/* DLT_ENC */
case IFT_ENC:
hlen = 12; /* XXXGL: sizeof(struct enchdr); */
break;
/* DLT_EN10MB */
case IFT_ETHER: /* if_ethersubr.c */
case IFT_L2VLAN: /* vlan(4) */
case IFT_BRIDGE: /* if_bridge(4) */
case IFT_IEEE8023ADLAG: /* lagg(4) */
case IFT_INFINIBAND: /* if_infiniband.c */
{
struct ether_header *eh;
eh = mtod(m, struct ether_header *);
if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost,
ETHER_ADDR_LEN) == 0)
m->m_flags |= M_BCAST;
else
m->m_flags |= M_MCAST;
}
if (!(flags & BPFD_HDRCMPLT)) {
memcpy(eh->ether_shost, IF_LLADDR(ifp),
sizeof(eh->ether_shost));
}
hlen = ETHER_HDR_LEN;
break;
}
/* DLT_APPLE_IP_OVER_IEEE1394 */
case IFT_IEEE1394: /* fwip(4) */
hlen = sizeof(struct fw_hwaddr);
break;
/* DLT_NULL */
case IFT_GIF: /* gif(4) */
case IFT_LOOP: /* lo(4), disc(4) */
case IFT_PARA: /* plip(4), iic */
case IFT_PPP: /* tun(4) */
case IFT_PROPVIRTUAL: /* ng_iface(4) */
case IFT_WIREGUARD: /* wg(4) */
case IFT_STF: /* stf(4) */
case IFT_TUNNEL: /* ipsec(4), me(4), gre(4), ovpn(4) */
hlen = sizeof(uint32_t);
break;
/* DLT_PFLOG */
case IFT_PFLOG:
hlen = PFLOG_HDRLEN;
break;
/* DLT_PFSYNC */
case IFT_PFSYNC:
hlen = PFSYNC_HDRLEN;
break;
default:
hlen = 0; /* pacify compiler */
KASSERT(0, ("%s: ifp %p type %u not supported", __func__,
ifp, ifp->if_type));
}
if (__predict_false(hlen > m->m_len)) {
m_freem(m);
m_freem(mc);
return (EMSGSIZE);
};
if (hlen != 0) {
bcopy(mtod(m, const void *), &dst.sa_data, hlen);
ro.ro_prepend = (char *)&dst.sa_data;
ro.ro_plen = hlen;
ro.ro_flags = RT_HAS_HEADER;
m->m_pkthdr.len -= hlen;
m->m_len -= hlen;
m->m_data += hlen;
};
CURVNET_SET(ifp->if_vnet);
error = ifp->if_output(ifp, m, &dst, &ro);
if (error != 0) {
m_freem(mc);
} else if (mc != NULL) {
mc->m_pkthdr.rcvif = ifp;
(void)ifp->if_input(ifp, mc);
}
CURVNET_RESTORE();
return (error);
}
static bool
bpf_ifnet_chkdir(void *arg, const struct mbuf *m, int dir)
{
struct ifnet *ifp = arg;
struct ifnet *rcvif = m_rcvif(m);
return ((dir == BPF_D_IN && ifp != rcvif) ||
(dir == BPF_D_OUT && ifp == rcvif));
}
uint32_t
bpf_ifnet_wrsize(void *arg)
{
struct ifnet *ifp = arg;
return (ifp->if_mtu);
}
int
bpf_ifnet_promisc(void *arg, bool on)
{
struct ifnet *ifp = arg;
int error;
CURVNET_SET(ifp->if_vnet);
if ((error = ifpromisc(ifp, on ? 1 : 0)) != 0)
if_printf(ifp, "%s: ifpromisc failed (%d)\n", __func__, error);
CURVNET_RESTORE();
return (error);
}
#ifdef MAC
static int
bpf_ifnet_mac_check_receive(void *arg, struct bpf_d *d)
{
struct ifnet *ifp = arg;
return (mac_bpfdesc_check_receive(d, ifp));
}
#endif
static const struct bif_methods bpf_ifnet_methods = {
.bif_chkdir = bpf_ifnet_chkdir,
.bif_promisc = bpf_ifnet_promisc,
.bif_wrsize = bpf_ifnet_wrsize,
.bif_write = bpf_ifnet_write,
#ifdef MAC
.bif_mac_check_receive = bpf_ifnet_mac_check_receive,
#endif
};
/*
* Attach an interface to bpf. dlt is the link layer type; hdrlen is the
* fixed size of the link header (variable length headers not yet supported).
* Legacy KPI to be obsoleted soon.
*/
void
bpfattach(struct ifnet *ifp, u_int dlt, u_int hdrlen)
{
ifp->if_bpf = bpf_attach(ifp->if_xname, dlt, hdrlen,
&bpf_ifnet_methods, ifp);
if_ref(ifp);
if (bootverbose && IS_DEFAULT_VNET(curvnet))
if_printf(ifp, "bpf attached\n");
}
/*
* The dead_bpf_if is an ugly plug against races at ifnet destroy time that
* still exist and are not properly covered by epoch(9).
* Legacy KPI to be obsoleted soon.
*/
void
bpfdetach(struct ifnet *ifp)
{
static const struct bpfd_list dead_bpf_if = CK_LIST_HEAD_INITIALIZER();
struct bpf_if *bif;
bif = ifp->if_bpf;
ifp->if_bpf = __DECONST(struct bpf_if *, &dead_bpf_if);
bpf_detach(bif);
if_rele(ifp);
}
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