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freebsd-skq/sys/netinet/ip_input.c
ae 694891e438 Restore ability to send ICMP and ICMPv6 redirects. 
It was lost when tryforward appeared. Now ip[6]_tryforward will be enabled
only when sending redirects for corresponding IP version is disabled via
sysctl. Otherwise will be used default forwarding function.

PR:		221137
Submitted by:	mckay@
MFC after:	2 weeks
2018-08-14 07:54:14 +00:00

1430 lines
37 KiB
C
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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1982, 1986, 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
*
* @(#)ip_input.c 8.2 (Berkeley) 1/4/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_bootp.h"
#include "opt_ipstealth.h"
#include "opt_ipsec.h"
#include "opt_route.h"
#include "opt_rss.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/hhook.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
#include <sys/rwlock.h>
#include <sys/sdt.h>
#include <sys/syslog.h>
#include <sys/sysctl.h>
#include <net/pfil.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/netisr.h>
#include <net/rss_config.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_kdtrace.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#include <netinet/ip_fw.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip_options.h>
#include <machine/in_cksum.h>
#include <netinet/ip_carp.h>
#include <netinet/in_rss.h>
#include <netipsec/ipsec_support.h>
#include <sys/socketvar.h>
#include <security/mac/mac_framework.h>
#ifdef CTASSERT
CTASSERT(sizeof(struct ip) == 20);
#endif
/* IP reassembly functions are defined in ip_reass.c. */
extern void ipreass_init(void);
extern void ipreass_drain(void);
extern void ipreass_slowtimo(void);
#ifdef VIMAGE
extern void ipreass_destroy(void);
#endif
struct rmlock in_ifaddr_lock;
RM_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock");
VNET_DEFINE(int, rsvp_on);
VNET_DEFINE(int, ipforwarding);
SYSCTL_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(ipforwarding), 0,
"Enable IP forwarding between interfaces");
VNET_DEFINE_STATIC(int, ipsendredirects) = 1; /* XXX */
#define V_ipsendredirects VNET(ipsendredirects)
SYSCTL_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(ipsendredirects), 0,
"Enable sending IP redirects");
/*
* XXX - Setting ip_checkinterface mostly implements the receive side of
* the Strong ES model described in RFC 1122, but since the routing table
* and transmit implementation do not implement the Strong ES model,
* setting this to 1 results in an odd hybrid.
*
* XXX - ip_checkinterface currently must be disabled if you use ipnat
* to translate the destination address to another local interface.
*
* XXX - ip_checkinterface must be disabled if you add IP aliases
* to the loopback interface instead of the interface where the
* packets for those addresses are received.
*/
VNET_DEFINE_STATIC(int, ip_checkinterface);
#define V_ip_checkinterface VNET(ip_checkinterface)
SYSCTL_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(ip_checkinterface), 0,
"Verify packet arrives on correct interface");
VNET_DEFINE(struct pfil_head, inet_pfil_hook); /* Packet filter hooks */
static struct netisr_handler ip_nh = {
.nh_name = "ip",
.nh_handler = ip_input,
.nh_proto = NETISR_IP,
#ifdef RSS
.nh_m2cpuid = rss_soft_m2cpuid_v4,
.nh_policy = NETISR_POLICY_CPU,
.nh_dispatch = NETISR_DISPATCH_HYBRID,
#else
.nh_policy = NETISR_POLICY_FLOW,
#endif
};
#ifdef RSS
/*
* Directly dispatched frames are currently assumed
* to have a flowid already calculated.
*
* It should likely have something that assert it
* actually has valid flow details.
*/
static struct netisr_handler ip_direct_nh = {
.nh_name = "ip_direct",
.nh_handler = ip_direct_input,
.nh_proto = NETISR_IP_DIRECT,
.nh_m2cpuid = rss_soft_m2cpuid_v4,
.nh_policy = NETISR_POLICY_CPU,
.nh_dispatch = NETISR_DISPATCH_HYBRID,
};
#endif
extern struct domain inetdomain;
extern struct protosw inetsw[];
u_char ip_protox[IPPROTO_MAX];
VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead); /* first inet address */
VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table */
VNET_DEFINE(u_long, in_ifaddrhmask); /* mask for hash table */
#ifdef IPCTL_DEFMTU
SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
&ip_mtu, 0, "Default MTU");
#endif
#ifdef IPSTEALTH
VNET_DEFINE(int, ipstealth);
SYSCTL_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(ipstealth), 0,
"IP stealth mode, no TTL decrementation on forwarding");
#endif
/*
* IP statistics are stored in the "array" of counter(9)s.
*/
VNET_PCPUSTAT_DEFINE(struct ipstat, ipstat);
VNET_PCPUSTAT_SYSINIT(ipstat);
SYSCTL_VNET_PCPUSTAT(_net_inet_ip, IPCTL_STATS, stats, struct ipstat, ipstat,
"IP statistics (struct ipstat, netinet/ip_var.h)");
#ifdef VIMAGE
VNET_PCPUSTAT_SYSUNINIT(ipstat);
#endif /* VIMAGE */
/*
* Kernel module interface for updating ipstat. The argument is an index
* into ipstat treated as an array.
*/
void
kmod_ipstat_inc(int statnum)
{
counter_u64_add(VNET(ipstat)[statnum], 1);
}
void
kmod_ipstat_dec(int statnum)
{
counter_u64_add(VNET(ipstat)[statnum], -1);
}
static int
sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
{
int error, qlimit;
netisr_getqlimit(&ip_nh, &qlimit);
error = sysctl_handle_int(oidp, &qlimit, 0, req);
if (error || !req->newptr)
return (error);
if (qlimit < 1)
return (EINVAL);
return (netisr_setqlimit(&ip_nh, qlimit));
}
SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen,
CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_queue_maxlen, "I",
"Maximum size of the IP input queue");
static int
sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS)
{
u_int64_t qdrops_long;
int error, qdrops;
netisr_getqdrops(&ip_nh, &qdrops_long);
qdrops = qdrops_long;
error = sysctl_handle_int(oidp, &qdrops, 0, req);
if (error || !req->newptr)
return (error);
if (qdrops != 0)
return (EINVAL);
netisr_clearqdrops(&ip_nh);
return (0);
}
SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops,
CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_queue_drops, "I",
"Number of packets dropped from the IP input queue");
#ifdef RSS
static int
sysctl_netinet_intr_direct_queue_maxlen(SYSCTL_HANDLER_ARGS)
{
int error, qlimit;
netisr_getqlimit(&ip_direct_nh, &qlimit);
error = sysctl_handle_int(oidp, &qlimit, 0, req);
if (error || !req->newptr)
return (error);
if (qlimit < 1)
return (EINVAL);
return (netisr_setqlimit(&ip_direct_nh, qlimit));
}
SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQMAXLEN, intr_direct_queue_maxlen,
CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_direct_queue_maxlen,
"I", "Maximum size of the IP direct input queue");
static int
sysctl_netinet_intr_direct_queue_drops(SYSCTL_HANDLER_ARGS)
{
u_int64_t qdrops_long;
int error, qdrops;
netisr_getqdrops(&ip_direct_nh, &qdrops_long);
qdrops = qdrops_long;
error = sysctl_handle_int(oidp, &qdrops, 0, req);
if (error || !req->newptr)
return (error);
if (qdrops != 0)
return (EINVAL);
netisr_clearqdrops(&ip_direct_nh);
return (0);
}
SYSCTL_PROC(_net_inet_ip, IPCTL_INTRDQDROPS, intr_direct_queue_drops,
CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_direct_queue_drops, "I",
"Number of packets dropped from the IP direct input queue");
#endif /* RSS */
/*
* IP initialization: fill in IP protocol switch table.
* All protocols not implemented in kernel go to raw IP protocol handler.
*/
void
ip_init(void)
{
struct protosw *pr;
int i;
CK_STAILQ_INIT(&V_in_ifaddrhead);
V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
/* Initialize IP reassembly queue. */
ipreass_init();
/* Initialize packet filter hooks. */
V_inet_pfil_hook.ph_type = PFIL_TYPE_AF;
V_inet_pfil_hook.ph_af = AF_INET;
if ((i = pfil_head_register(&V_inet_pfil_hook)) != 0)
printf("%s: WARNING: unable to register pfil hook, "
"error %d\n", __func__, i);
if (hhook_head_register(HHOOK_TYPE_IPSEC_IN, AF_INET,
&V_ipsec_hhh_in[HHOOK_IPSEC_INET],
HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
printf("%s: WARNING: unable to register input helper hook\n",
__func__);
if (hhook_head_register(HHOOK_TYPE_IPSEC_OUT, AF_INET,
&V_ipsec_hhh_out[HHOOK_IPSEC_INET],
HHOOK_WAITOK | HHOOK_HEADISINVNET) != 0)
printf("%s: WARNING: unable to register output helper hook\n",
__func__);
/* Skip initialization of globals for non-default instances. */
#ifdef VIMAGE
if (!IS_DEFAULT_VNET(curvnet)) {
netisr_register_vnet(&ip_nh);
#ifdef RSS
netisr_register_vnet(&ip_direct_nh);
#endif
return;
}
#endif
pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
if (pr == NULL)
panic("ip_init: PF_INET not found");
/* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
for (i = 0; i < IPPROTO_MAX; i++)
ip_protox[i] = pr - inetsw;
/*
* Cycle through IP protocols and put them into the appropriate place
* in ip_protox[].
*/
for (pr = inetdomain.dom_protosw;
pr < inetdomain.dom_protoswNPROTOSW; pr++)
if (pr->pr_domain->dom_family == PF_INET &&
pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
/* Be careful to only index valid IP protocols. */
if (pr->pr_protocol < IPPROTO_MAX)
ip_protox[pr->pr_protocol] = pr - inetsw;
}
netisr_register(&ip_nh);
#ifdef RSS
netisr_register(&ip_direct_nh);
#endif
}
#ifdef VIMAGE
static void
ip_destroy(void *unused __unused)
{
struct ifnet *ifp;
int error;
#ifdef RSS
netisr_unregister_vnet(&ip_direct_nh);
#endif
netisr_unregister_vnet(&ip_nh);
if ((error = pfil_head_unregister(&V_inet_pfil_hook)) != 0)
printf("%s: WARNING: unable to unregister pfil hook, "
"error %d\n", __func__, error);
error = hhook_head_deregister(V_ipsec_hhh_in[HHOOK_IPSEC_INET]);
if (error != 0) {
printf("%s: WARNING: unable to deregister input helper hook "
"type HHOOK_TYPE_IPSEC_IN, id HHOOK_IPSEC_INET: "
"error %d returned\n", __func__, error);
}
error = hhook_head_deregister(V_ipsec_hhh_out[HHOOK_IPSEC_INET]);
if (error != 0) {
printf("%s: WARNING: unable to deregister output helper hook "
"type HHOOK_TYPE_IPSEC_OUT, id HHOOK_IPSEC_INET: "
"error %d returned\n", __func__, error);
}
/* Remove the IPv4 addresses from all interfaces. */
in_ifscrub_all();
/* Make sure the IPv4 routes are gone as well. */
IFNET_RLOCK();
CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link)
rt_flushifroutes_af(ifp, AF_INET);
IFNET_RUNLOCK();
/* Destroy IP reassembly queue. */
ipreass_destroy();
/* Cleanup in_ifaddr hash table; should be empty. */
hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
}
VNET_SYSUNINIT(ip, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, ip_destroy, NULL);
#endif
#ifdef RSS
/*
* IP direct input routine.
*
* This is called when reinjecting completed fragments where
* all of the previous checking and book-keeping has been done.
*/
void
ip_direct_input(struct mbuf *m)
{
struct ip *ip;
int hlen;
ip = mtod(m, struct ip *);
hlen = ip->ip_hl << 2;
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
if (IPSEC_ENABLED(ipv4)) {
if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
return;
}
#endif /* IPSEC */
IPSTAT_INC(ips_delivered);
(*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
return;
}
#endif
/*
* Ip input routine. Checksum and byte swap header. If fragmented
* try to reassemble. Process options. Pass to next level.
*/
void
ip_input(struct mbuf *m)
{
struct ip *ip = NULL;
struct in_ifaddr *ia = NULL;
struct ifaddr *ifa;
struct ifnet *ifp;
int checkif, hlen = 0;
uint16_t sum, ip_len;
int dchg = 0; /* dest changed after fw */
struct in_addr odst; /* original dst address */
M_ASSERTPKTHDR(m);
if (m->m_flags & M_FASTFWD_OURS) {
m->m_flags &= ~M_FASTFWD_OURS;
/* Set up some basics that will be used later. */
ip = mtod(m, struct ip *);
hlen = ip->ip_hl << 2;
ip_len = ntohs(ip->ip_len);
goto ours;
}
IPSTAT_INC(ips_total);
if (m->m_pkthdr.len < sizeof(struct ip))
goto tooshort;
if (m->m_len < sizeof (struct ip) &&
(m = m_pullup(m, sizeof (struct ip))) == NULL) {
IPSTAT_INC(ips_toosmall);
return;
}
ip = mtod(m, struct ip *);
if (ip->ip_v != IPVERSION) {
IPSTAT_INC(ips_badvers);
goto bad;
}
hlen = ip->ip_hl << 2;
if (hlen < sizeof(struct ip)) { /* minimum header length */
IPSTAT_INC(ips_badhlen);
goto bad;
}
if (hlen > m->m_len) {
if ((m = m_pullup(m, hlen)) == NULL) {
IPSTAT_INC(ips_badhlen);
return;
}
ip = mtod(m, struct ip *);
}
IP_PROBE(receive, NULL, NULL, ip, m->m_pkthdr.rcvif, ip, NULL);
/* 127/8 must not appear on wire - RFC1122 */
ifp = m->m_pkthdr.rcvif;
if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
(ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
IPSTAT_INC(ips_badaddr);
goto bad;
}
}
if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
} else {
if (hlen == sizeof(struct ip)) {
sum = in_cksum_hdr(ip);
} else {
sum = in_cksum(m, hlen);
}
}
if (sum) {
IPSTAT_INC(ips_badsum);
goto bad;
}
#ifdef ALTQ
if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
/* packet is dropped by traffic conditioner */
return;
#endif
ip_len = ntohs(ip->ip_len);
if (ip_len < hlen) {
IPSTAT_INC(ips_badlen);
goto bad;
}
/*
* Check that the amount of data in the buffers
* is as at least much as the IP header would have us expect.
* Trim mbufs if longer than we expect.
* Drop packet if shorter than we expect.
*/
if (m->m_pkthdr.len < ip_len) {
tooshort:
IPSTAT_INC(ips_tooshort);
goto bad;
}
if (m->m_pkthdr.len > ip_len) {
if (m->m_len == m->m_pkthdr.len) {
m->m_len = ip_len;
m->m_pkthdr.len = ip_len;
} else
m_adj(m, ip_len - m->m_pkthdr.len);
}
/*
* Try to forward the packet, but if we fail continue.
* ip_tryforward() does not generate redirects, so fall
* through to normal processing if redirects are required.
* ip_tryforward() does inbound and outbound packet firewall
* processing. If firewall has decided that destination becomes
* our local address, it sets M_FASTFWD_OURS flag. In this
* case skip another inbound firewall processing and update
* ip pointer.
*/
if (V_ipforwarding != 0 && V_ipsendredirects == 0
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
&& (!IPSEC_ENABLED(ipv4) ||
IPSEC_CAPS(ipv4, m, IPSEC_CAP_OPERABLE) == 0)
#endif
) {
if ((m = ip_tryforward(m)) == NULL)
return;
if (m->m_flags & M_FASTFWD_OURS) {
m->m_flags &= ~M_FASTFWD_OURS;
ip = mtod(m, struct ip *);
goto ours;
}
}
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
/*
* Bypass packet filtering for packets previously handled by IPsec.
*/
if (IPSEC_ENABLED(ipv4) &&
IPSEC_CAPS(ipv4, m, IPSEC_CAP_BYPASS_FILTER) != 0)
goto passin;
#endif
/*
* Run through list of hooks for input packets.
*
* NB: Beware of the destination address changing (e.g.
* by NAT rewriting). When this happens, tell
* ip_forward to do the right thing.
*/
/* Jump over all PFIL processing if hooks are not active. */
if (!PFIL_HOOKED(&V_inet_pfil_hook))
goto passin;
odst = ip->ip_dst;
if (pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_IN, 0, NULL) != 0)
return;
if (m == NULL) /* consumed by filter */
return;
ip = mtod(m, struct ip *);
dchg = (odst.s_addr != ip->ip_dst.s_addr);
ifp = m->m_pkthdr.rcvif;
if (m->m_flags & M_FASTFWD_OURS) {
m->m_flags &= ~M_FASTFWD_OURS;
goto ours;
}
if (m->m_flags & M_IP_NEXTHOP) {
if (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL) {
/*
* Directly ship the packet on. This allows
* forwarding packets originally destined to us
* to some other directly connected host.
*/
ip_forward(m, 1);
return;
}
}
passin:
/*
* Process options and, if not destined for us,
* ship it on. ip_dooptions returns 1 when an
* error was detected (causing an icmp message
* to be sent and the original packet to be freed).
*/
if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
return;
/* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
* matter if it is destined to another node, or whether it is
* a multicast one, RSVP wants it! and prevents it from being forwarded
* anywhere else. Also checks if the rsvp daemon is running before
* grabbing the packet.
*/
if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
goto ours;
/*
* Check our list of addresses, to see if the packet is for us.
* If we don't have any addresses, assume any unicast packet
* we receive might be for us (and let the upper layers deal
* with it).
*/
if (CK_STAILQ_EMPTY(&V_in_ifaddrhead) &&
(m->m_flags & (M_MCAST|M_BCAST)) == 0)
goto ours;
/*
* Enable a consistency check between the destination address
* and the arrival interface for a unicast packet (the RFC 1122
* strong ES model) if IP forwarding is disabled and the packet
* is not locally generated and the packet is not subject to
* 'ipfw fwd'.
*
* XXX - Checking also should be disabled if the destination
* address is ipnat'ed to a different interface.
*
* XXX - Checking is incompatible with IP aliases added
* to the loopback interface instead of the interface where
* the packets are received.
*
* XXX - This is the case for carp vhost IPs as well so we
* insert a workaround. If the packet got here, we already
* checked with carp_iamatch() and carp_forus().
*/
checkif = V_ip_checkinterface && (V_ipforwarding == 0) &&
ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
ifp->if_carp == NULL && (dchg == 0);
/*
* Check for exact addresses in the hash bucket.
*/
/* IN_IFADDR_RLOCK(); */
LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
/*
* If the address matches, verify that the packet
* arrived via the correct interface if checking is
* enabled.
*/
if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
(!checkif || ia->ia_ifp == ifp)) {
counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
counter_u64_add(ia->ia_ifa.ifa_ibytes,
m->m_pkthdr.len);
/* IN_IFADDR_RUNLOCK(); */
goto ours;
}
}
/* IN_IFADDR_RUNLOCK(); */
/*
* Check for broadcast addresses.
*
* Only accept broadcast packets that arrive via the matching
* interface. Reception of forwarded directed broadcasts would
* be handled via ip_forward() and ether_output() with the loopback
* into the stack for SIMPLEX interfaces handled by ether_output().
*/
if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
IF_ADDR_RLOCK(ifp);
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
ia = ifatoia(ifa);
if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
ip->ip_dst.s_addr) {
counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
counter_u64_add(ia->ia_ifa.ifa_ibytes,
m->m_pkthdr.len);
IF_ADDR_RUNLOCK(ifp);
goto ours;
}
#ifdef BOOTP_COMPAT
if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
counter_u64_add(ia->ia_ifa.ifa_ipackets, 1);
counter_u64_add(ia->ia_ifa.ifa_ibytes,
m->m_pkthdr.len);
IF_ADDR_RUNLOCK(ifp);
goto ours;
}
#endif
}
IF_ADDR_RUNLOCK(ifp);
ia = NULL;
}
/* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */
if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) {
IPSTAT_INC(ips_cantforward);
m_freem(m);
return;
}
if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
if (V_ip_mrouter) {
/*
* If we are acting as a multicast router, all
* incoming multicast packets are passed to the
* kernel-level multicast forwarding function.
* The packet is returned (relatively) intact; if
* ip_mforward() returns a non-zero value, the packet
* must be discarded, else it may be accepted below.
*/
if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
IPSTAT_INC(ips_cantforward);
m_freem(m);
return;
}
/*
* The process-level routing daemon needs to receive
* all multicast IGMP packets, whether or not this
* host belongs to their destination groups.
*/
if (ip->ip_p == IPPROTO_IGMP)
goto ours;
IPSTAT_INC(ips_forward);
}
/*
* Assume the packet is for us, to avoid prematurely taking
* a lock on the in_multi hash. Protocols must perform
* their own filtering and update statistics accordingly.
*/
goto ours;
}
if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
goto ours;
if (ip->ip_dst.s_addr == INADDR_ANY)
goto ours;
/*
* Not for us; forward if possible and desirable.
*/
if (V_ipforwarding == 0) {
IPSTAT_INC(ips_cantforward);
m_freem(m);
} else {
ip_forward(m, dchg);
}
return;
ours:
#ifdef IPSTEALTH
/*
* IPSTEALTH: Process non-routing options only
* if the packet is destined for us.
*/
if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1))
return;
#endif /* IPSTEALTH */
/*
* Attempt reassembly; if it succeeds, proceed.
* ip_reass() will return a different mbuf.
*/
if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
/* XXXGL: shouldn't we save & set m_flags? */
m = ip_reass(m);
if (m == NULL)
return;
ip = mtod(m, struct ip *);
/* Get the header length of the reassembled packet */
hlen = ip->ip_hl << 2;
}
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
if (IPSEC_ENABLED(ipv4)) {
if (IPSEC_INPUT(ipv4, m, hlen, ip->ip_p) != 0)
return;
}
#endif /* IPSEC */
/*
* Switch out to protocol's input routine.
*/
IPSTAT_INC(ips_delivered);
(*inetsw[ip_protox[ip->ip_p]].pr_input)(&m, &hlen, ip->ip_p);
return;
bad:
m_freem(m);
}
/*
* IP timer processing;
* if a timer expires on a reassembly
* queue, discard it.
*/
void
ip_slowtimo(void)
{
VNET_ITERATOR_DECL(vnet_iter);
VNET_LIST_RLOCK_NOSLEEP();
VNET_FOREACH(vnet_iter) {
CURVNET_SET(vnet_iter);
ipreass_slowtimo();
CURVNET_RESTORE();
}
VNET_LIST_RUNLOCK_NOSLEEP();
}
void
ip_drain(void)
{
VNET_ITERATOR_DECL(vnet_iter);
VNET_LIST_RLOCK_NOSLEEP();
VNET_FOREACH(vnet_iter) {
CURVNET_SET(vnet_iter);
ipreass_drain();
CURVNET_RESTORE();
}
VNET_LIST_RUNLOCK_NOSLEEP();
}
/*
* The protocol to be inserted into ip_protox[] must be already registered
* in inetsw[], either statically or through pf_proto_register().
*/
int
ipproto_register(short ipproto)
{
struct protosw *pr;
/* Sanity checks. */
if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
return (EPROTONOSUPPORT);
/*
* The protocol slot must not be occupied by another protocol
* already. An index pointing to IPPROTO_RAW is unused.
*/
pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
if (pr == NULL)
return (EPFNOSUPPORT);
if (ip_protox[ipproto] != pr - inetsw) /* IPPROTO_RAW */
return (EEXIST);
/* Find the protocol position in inetsw[] and set the index. */
for (pr = inetdomain.dom_protosw;
pr < inetdomain.dom_protoswNPROTOSW; pr++) {
if (pr->pr_domain->dom_family == PF_INET &&
pr->pr_protocol && pr->pr_protocol == ipproto) {
ip_protox[pr->pr_protocol] = pr - inetsw;
return (0);
}
}
return (EPROTONOSUPPORT);
}
int
ipproto_unregister(short ipproto)
{
struct protosw *pr;
/* Sanity checks. */
if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
return (EPROTONOSUPPORT);
/* Check if the protocol was indeed registered. */
pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
if (pr == NULL)
return (EPFNOSUPPORT);
if (ip_protox[ipproto] == pr - inetsw) /* IPPROTO_RAW */
return (ENOENT);
/* Reset the protocol slot to IPPROTO_RAW. */
ip_protox[ipproto] = pr - inetsw;
return (0);
}
u_char inetctlerrmap[PRC_NCMDS] = {
0, 0, 0, 0,
0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
EMSGSIZE, EHOSTUNREACH, 0, 0,
0, 0, EHOSTUNREACH, 0,
ENOPROTOOPT, ECONNREFUSED
};
/*
* Forward a packet. If some error occurs return the sender
* an icmp packet. Note we can't always generate a meaningful
* icmp message because icmp doesn't have a large enough repertoire
* of codes and types.
*
* If not forwarding, just drop the packet. This could be confusing
* if ipforwarding was zero but some routing protocol was advancing
* us as a gateway to somewhere. However, we must let the routing
* protocol deal with that.
*
* The srcrt parameter indicates whether the packet is being forwarded
* via a source route.
*/
void
ip_forward(struct mbuf *m, int srcrt)
{
struct ip *ip = mtod(m, struct ip *);
struct in_ifaddr *ia;
struct mbuf *mcopy;
struct sockaddr_in *sin;
struct in_addr dest;
struct route ro;
int error, type = 0, code = 0, mtu = 0;
if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
IPSTAT_INC(ips_cantforward);
m_freem(m);
return;
}
if (
#ifdef IPSTEALTH
V_ipstealth == 0 &&
#endif
ip->ip_ttl <= IPTTLDEC) {
icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, 0);
return;
}
bzero(&ro, sizeof(ro));
sin = (struct sockaddr_in *)&ro.ro_dst;
sin->sin_family = AF_INET;
sin->sin_len = sizeof(*sin);
sin->sin_addr = ip->ip_dst;
#ifdef RADIX_MPATH
rtalloc_mpath_fib(&ro,
ntohl(ip->ip_src.s_addr ^ ip->ip_dst.s_addr),
M_GETFIB(m));
#else
in_rtalloc_ign(&ro, 0, M_GETFIB(m));
#endif
NET_EPOCH_ENTER();
if (ro.ro_rt != NULL) {
ia = ifatoia(ro.ro_rt->rt_ifa);
} else
ia = NULL;
/*
* Save the IP header and at most 8 bytes of the payload,
* in case we need to generate an ICMP message to the src.
*
* XXX this can be optimized a lot by saving the data in a local
* buffer on the stack (72 bytes at most), and only allocating the
* mbuf if really necessary. The vast majority of the packets
* are forwarded without having to send an ICMP back (either
* because unnecessary, or because rate limited), so we are
* really we are wasting a lot of work here.
*
* We don't use m_copym() because it might return a reference
* to a shared cluster. Both this function and ip_output()
* assume exclusive access to the IP header in `m', so any
* data in a cluster may change before we reach icmp_error().
*/
mcopy = m_gethdr(M_NOWAIT, m->m_type);
if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
/*
* It's probably ok if the pkthdr dup fails (because
* the deep copy of the tag chain failed), but for now
* be conservative and just discard the copy since
* code below may some day want the tags.
*/
m_free(mcopy);
mcopy = NULL;
}
if (mcopy != NULL) {
mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy));
mcopy->m_pkthdr.len = mcopy->m_len;
m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
}
#ifdef IPSTEALTH
if (V_ipstealth == 0)
#endif
ip->ip_ttl -= IPTTLDEC;
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
if (IPSEC_ENABLED(ipv4)) {
if ((error = IPSEC_FORWARD(ipv4, m)) != 0) {
/* mbuf consumed by IPsec */
m_freem(mcopy);
if (error != EINPROGRESS)
IPSTAT_INC(ips_cantforward);
goto out;
}
/* No IPsec processing required */
}
#endif /* IPSEC */
/*
* If forwarding packet using same interface that it came in on,
* perhaps should send a redirect to sender to shortcut a hop.
* Only send redirect if source is sending directly to us,
* and if packet was not source routed (or has any options).
* Also, don't send redirect if forwarding using a default route
* or a route modified by a redirect.
*/
dest.s_addr = 0;
if (!srcrt && V_ipsendredirects &&
ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
struct rtentry *rt;
rt = ro.ro_rt;
if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
satosin(rt_key(rt))->sin_addr.s_addr != 0) {
#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
u_long src = ntohl(ip->ip_src.s_addr);
if (RTA(rt) &&
(src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
if (rt->rt_flags & RTF_GATEWAY)
dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
else
dest.s_addr = ip->ip_dst.s_addr;
/* Router requirements says to only send host redirects */
type = ICMP_REDIRECT;
code = ICMP_REDIRECT_HOST;
}
}
}
error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
if (error == EMSGSIZE && ro.ro_rt)
mtu = ro.ro_rt->rt_mtu;
RO_RTFREE(&ro);
if (error)
IPSTAT_INC(ips_cantforward);
else {
IPSTAT_INC(ips_forward);
if (type)
IPSTAT_INC(ips_redirectsent);
else {
if (mcopy)
m_freem(mcopy);
goto out;
}
}
if (mcopy == NULL)
goto out;
switch (error) {
case 0: /* forwarded, but need redirect */
/* type, code set above */
break;
case ENETUNREACH:
case EHOSTUNREACH:
case ENETDOWN:
case EHOSTDOWN:
default:
type = ICMP_UNREACH;
code = ICMP_UNREACH_HOST;
break;
case EMSGSIZE:
type = ICMP_UNREACH;
code = ICMP_UNREACH_NEEDFRAG;
/*
* If the MTU was set before make sure we are below the
* interface MTU.
* If the MTU wasn't set before use the interface mtu or
* fall back to the next smaller mtu step compared to the
* current packet size.
*/
if (mtu != 0) {
if (ia != NULL)
mtu = min(mtu, ia->ia_ifp->if_mtu);
} else {
if (ia != NULL)
mtu = ia->ia_ifp->if_mtu;
else
mtu = ip_next_mtu(ntohs(ip->ip_len), 0);
}
IPSTAT_INC(ips_cantfrag);
break;
case ENOBUFS:
case EACCES: /* ipfw denied packet */
m_freem(mcopy);
goto out;
}
icmp_error(mcopy, type, code, dest.s_addr, mtu);
out:
NET_EPOCH_EXIT();
}
#define CHECK_SO_CT(sp, ct) \
(((sp->so_options & SO_TIMESTAMP) && (sp->so_ts_clock == ct)) ? 1 : 0)
void
ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
struct mbuf *m)
{
bool stamped;
stamped = false;
if ((inp->inp_socket->so_options & SO_BINTIME) ||
CHECK_SO_CT(inp->inp_socket, SO_TS_BINTIME)) {
struct bintime boottimebin, bt;
struct timespec ts1;
if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
M_TSTMP)) {
mbuf_tstmp2timespec(m, &ts1);
timespec2bintime(&ts1, &bt);
getboottimebin(&boottimebin);
bintime_add(&bt, &boottimebin);
} else {
bintime(&bt);
}
*mp = sbcreatecontrol((caddr_t)&bt, sizeof(bt),
SCM_BINTIME, SOL_SOCKET);
if (*mp != NULL) {
mp = &(*mp)->m_next;
stamped = true;
}
}
if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME_MICRO)) {
struct bintime boottimebin, bt1;
struct timespec ts1;;
struct timeval tv;
if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
M_TSTMP)) {
mbuf_tstmp2timespec(m, &ts1);
timespec2bintime(&ts1, &bt1);
getboottimebin(&boottimebin);
bintime_add(&bt1, &boottimebin);
bintime2timeval(&bt1, &tv);
} else {
microtime(&tv);
}
*mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv),
SCM_TIMESTAMP, SOL_SOCKET);
if (*mp != NULL) {
mp = &(*mp)->m_next;
stamped = true;
}
} else if (CHECK_SO_CT(inp->inp_socket, SO_TS_REALTIME)) {
struct bintime boottimebin;
struct timespec ts, ts1;
if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
M_TSTMP)) {
mbuf_tstmp2timespec(m, &ts);
getboottimebin(&boottimebin);
bintime2timespec(&boottimebin, &ts1);
timespecadd(&ts, &ts1, &ts);
} else {
nanotime(&ts);
}
*mp = sbcreatecontrol((caddr_t)&ts, sizeof(ts),
SCM_REALTIME, SOL_SOCKET);
if (*mp != NULL) {
mp = &(*mp)->m_next;
stamped = true;
}
} else if (CHECK_SO_CT(inp->inp_socket, SO_TS_MONOTONIC)) {
struct timespec ts;
if ((m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
M_TSTMP))
mbuf_tstmp2timespec(m, &ts);
else
nanouptime(&ts);
*mp = sbcreatecontrol((caddr_t)&ts, sizeof(ts),
SCM_MONOTONIC, SOL_SOCKET);
if (*mp != NULL) {
mp = &(*mp)->m_next;
stamped = true;
}
}
if (stamped && (m->m_flags & (M_PKTHDR | M_TSTMP)) == (M_PKTHDR |
M_TSTMP)) {
struct sock_timestamp_info sti;
bzero(&sti, sizeof(sti));
sti.st_info_flags = ST_INFO_HW;
if ((m->m_flags & M_TSTMP_HPREC) != 0)
sti.st_info_flags |= ST_INFO_HW_HPREC;
*mp = sbcreatecontrol((caddr_t)&sti, sizeof(sti), SCM_TIME_INFO,
SOL_SOCKET);
if (*mp != NULL)
mp = &(*mp)->m_next;
}
if (inp->inp_flags & INP_RECVDSTADDR) {
*mp = sbcreatecontrol((caddr_t)&ip->ip_dst,
sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
if (inp->inp_flags & INP_RECVTTL) {
*mp = sbcreatecontrol((caddr_t)&ip->ip_ttl,
sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
#ifdef notyet
/* XXX
* Moving these out of udp_input() made them even more broken
* than they already were.
*/
/* options were tossed already */
if (inp->inp_flags & INP_RECVOPTS) {
*mp = sbcreatecontrol((caddr_t)opts_deleted_above,
sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
/* ip_srcroute doesn't do what we want here, need to fix */
if (inp->inp_flags & INP_RECVRETOPTS) {
*mp = sbcreatecontrol((caddr_t)ip_srcroute(m),
sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
#endif
if (inp->inp_flags & INP_RECVIF) {
struct ifnet *ifp;
struct sdlbuf {
struct sockaddr_dl sdl;
u_char pad[32];
} sdlbuf;
struct sockaddr_dl *sdp;
struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
if ((ifp = m->m_pkthdr.rcvif) &&
ifp->if_index && ifp->if_index <= V_if_index) {
sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
/*
* Change our mind and don't try copy.
*/
if (sdp->sdl_family != AF_LINK ||
sdp->sdl_len > sizeof(sdlbuf)) {
goto makedummy;
}
bcopy(sdp, sdl2, sdp->sdl_len);
} else {
makedummy:
sdl2->sdl_len =
offsetof(struct sockaddr_dl, sdl_data[0]);
sdl2->sdl_family = AF_LINK;
sdl2->sdl_index = 0;
sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
}
*mp = sbcreatecontrol((caddr_t)sdl2, sdl2->sdl_len,
IP_RECVIF, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
if (inp->inp_flags & INP_RECVTOS) {
*mp = sbcreatecontrol((caddr_t)&ip->ip_tos,
sizeof(u_char), IP_RECVTOS, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
if (inp->inp_flags2 & INP_RECVFLOWID) {
uint32_t flowid, flow_type;
flowid = m->m_pkthdr.flowid;
flow_type = M_HASHTYPE_GET(m);
/*
* XXX should handle the failure of one or the
* other - don't populate both?
*/
*mp = sbcreatecontrol((caddr_t) &flowid,
sizeof(uint32_t), IP_FLOWID, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
*mp = sbcreatecontrol((caddr_t) &flow_type,
sizeof(uint32_t), IP_FLOWTYPE, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
#ifdef RSS
if (inp->inp_flags2 & INP_RECVRSSBUCKETID) {
uint32_t flowid, flow_type;
uint32_t rss_bucketid;
flowid = m->m_pkthdr.flowid;
flow_type = M_HASHTYPE_GET(m);
if (rss_hash2bucket(flowid, flow_type, &rss_bucketid) == 0) {
*mp = sbcreatecontrol((caddr_t) &rss_bucketid,
sizeof(uint32_t), IP_RSSBUCKETID, IPPROTO_IP);
if (*mp)
mp = &(*mp)->m_next;
}
}
#endif
}
/*
* XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
* ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
* locking. This code remains in ip_input.c as ip_mroute.c is optionally
* compiled.
*/
VNET_DEFINE_STATIC(int, ip_rsvp_on);
VNET_DEFINE(struct socket *, ip_rsvpd);
#define V_ip_rsvp_on VNET(ip_rsvp_on)
int
ip_rsvp_init(struct socket *so)
{
if (so->so_type != SOCK_RAW ||
so->so_proto->pr_protocol != IPPROTO_RSVP)
return EOPNOTSUPP;
if (V_ip_rsvpd != NULL)
return EADDRINUSE;
V_ip_rsvpd = so;
/*
* This may seem silly, but we need to be sure we don't over-increment
* the RSVP counter, in case something slips up.
*/
if (!V_ip_rsvp_on) {
V_ip_rsvp_on = 1;
V_rsvp_on++;
}
return 0;
}
int
ip_rsvp_done(void)
{
V_ip_rsvpd = NULL;
/*
* This may seem silly, but we need to be sure we don't over-decrement
* the RSVP counter, in case something slips up.
*/
if (V_ip_rsvp_on) {
V_ip_rsvp_on = 0;
V_rsvp_on--;
}
return 0;
}
int
rsvp_input(struct mbuf **mp, int *offp, int proto)
{
struct mbuf *m;
m = *mp;
*mp = NULL;
if (rsvp_input_p) { /* call the real one if loaded */
*mp = m;
rsvp_input_p(mp, offp, proto);
return (IPPROTO_DONE);
}
/* Can still get packets with rsvp_on = 0 if there is a local member
* of the group to which the RSVP packet is addressed. But in this
* case we want to throw the packet away.
*/
if (!V_rsvp_on) {
m_freem(m);
return (IPPROTO_DONE);
}
if (V_ip_rsvpd != NULL) {
*mp = m;
rip_input(mp, offp, proto);
return (IPPROTO_DONE);
}
/* Drop the packet */
m_freem(m);
return (IPPROTO_DONE);
}
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