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freebsd-dev/sys/netinet/in.c
Shivank Garg 215bab7924 mac_ipacl: new MAC policy module to limit jail/vnet IP configuration 
The mac_ipacl policy module enables fine-grained control over IP address
configuration within VNET jails from the base system.
It allows the root user to define rules governing IP addresses for
jails and their interfaces using the sysctl interface.

Requested by:	multiple
Sponsored by:	Google, Inc. (GSoC 2019)
MFC after:	2 months
Reviewed by:	bz, dch (both earlier versions)
Differential Revision: https://reviews.freebsd.org/D20967
2023-07-26 00:07:57 +00:00

1870 lines
48 KiB
C
Raw Blame History

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
* Copyright (C) 2001 WIDE Project. 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.
*
* @(#)in.c 8.4 (Berkeley) 1/9/95
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#define IN_HISTORICAL_NETS /* include class masks */
#include <sys/param.h>
#include <sys/eventhandler.h>
#include <sys/systm.h>
#include <sys/sockio.h>
#include <sys/malloc.h>
#include <sys/priv.h>
#include <sys/socket.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/sx.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_arp.h>
#include <net/if_dl.h>
#include <net/if_llatbl.h>
#include <net/if_private.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/route/nhop.h>
#include <net/route/route_ctl.h>
#include <net/vnet.h>
#include <netinet/if_ether.h>
#include <netinet/in.h>
#include <netinet/in_fib.h>
#include <netinet/in_var.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#include <netinet/ip_carp.h>
#include <netinet/igmp_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#ifdef MAC
#include <security/mac/mac_framework.h>
#endif
static int in_aifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *);
static int in_difaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *);
static int in_gifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct ucred *);
static void in_socktrim(struct sockaddr_in *);
static void in_purgemaddrs(struct ifnet *);
static bool ia_need_loopback_route(const struct in_ifaddr *);
VNET_DEFINE_STATIC(int, nosameprefix);
#define V_nosameprefix VNET(nosameprefix)
SYSCTL_INT(_net_inet_ip, OID_AUTO, no_same_prefix, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(nosameprefix), 0,
"Refuse to create same prefixes on different interfaces");
VNET_DEFINE_STATIC(bool, broadcast_lowest);
#define V_broadcast_lowest VNET(broadcast_lowest)
SYSCTL_BOOL(_net_inet_ip, OID_AUTO, broadcast_lowest, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(broadcast_lowest), 0,
"Treat lowest address on a subnet (host 0) as broadcast");
VNET_DEFINE(bool, ip_allow_net240) = false;
#define V_ip_allow_net240 VNET(ip_allow_net240)
SYSCTL_BOOL(_net_inet_ip, OID_AUTO, allow_net240,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_allow_net240), 0,
"Allow use of Experimental addresses, aka Class E (240/4)");
/* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-240 */
VNET_DEFINE(bool, ip_allow_net0) = false;
SYSCTL_BOOL(_net_inet_ip, OID_AUTO, allow_net0,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_allow_net0), 0,
"Allow use of addresses in network 0/8");
/* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-0 */
VNET_DEFINE(uint32_t, in_loopback_mask) = IN_LOOPBACK_MASK_DFLT;
#define V_in_loopback_mask VNET(in_loopback_mask)
static int sysctl_loopback_prefixlen(SYSCTL_HANDLER_ARGS);
SYSCTL_PROC(_net_inet_ip, OID_AUTO, loopback_prefixlen,
CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW,
NULL, 0, sysctl_loopback_prefixlen, "I",
"Prefix length of address space reserved for loopback");
/* see https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-127 */
VNET_DECLARE(struct inpcbinfo, ripcbinfo);
#define V_ripcbinfo VNET(ripcbinfo)
static struct sx in_control_sx;
SX_SYSINIT(in_control_sx, &in_control_sx, "in_control");
/*
* Return 1 if an internet address is for a ``local'' host
* (one to which we have a connection).
*/
int
in_localaddr(struct in_addr in)
{
u_long i = ntohl(in.s_addr);
struct in_ifaddr *ia;
NET_EPOCH_ASSERT();
CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
if ((i & ia->ia_subnetmask) == ia->ia_subnet)
return (1);
}
return (0);
}
/*
* Return 1 if an internet address is for the local host and configured
* on one of its interfaces.
*/
bool
in_localip(struct in_addr in)
{
struct in_ifaddr *ia;
NET_EPOCH_ASSERT();
CK_LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash)
if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr)
return (true);
return (false);
}
/*
* Like in_localip(), but FIB-aware.
*/
bool
in_localip_fib(struct in_addr in, uint16_t fib)
{
struct in_ifaddr *ia;
NET_EPOCH_ASSERT();
CK_LIST_FOREACH(ia, INADDR_HASH(in.s_addr), ia_hash)
if (IA_SIN(ia)->sin_addr.s_addr == in.s_addr &&
ia->ia_ifa.ifa_ifp->if_fib == fib)
return (true);
return (false);
}
/*
* Return 1 if an internet address is configured on an interface.
*/
int
in_ifhasaddr(struct ifnet *ifp, struct in_addr in)
{
struct ifaddr *ifa;
struct in_ifaddr *ia;
NET_EPOCH_ASSERT();
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
ia = (struct in_ifaddr *)ifa;
if (ia->ia_addr.sin_addr.s_addr == in.s_addr)
return (1);
}
return (0);
}
/*
* Return a reference to the interface address which is different to
* the supplied one but with same IP address value.
*/
static struct in_ifaddr *
in_localip_more(struct in_ifaddr *original_ia)
{
struct epoch_tracker et;
in_addr_t original_addr = IA_SIN(original_ia)->sin_addr.s_addr;
uint32_t original_fib = original_ia->ia_ifa.ifa_ifp->if_fib;
struct in_ifaddr *ia;
NET_EPOCH_ENTER(et);
CK_LIST_FOREACH(ia, INADDR_HASH(original_addr), ia_hash) {
in_addr_t addr = IA_SIN(ia)->sin_addr.s_addr;
uint32_t fib = ia->ia_ifa.ifa_ifp->if_fib;
if (!V_rt_add_addr_allfibs && (original_fib != fib))
continue;
if ((original_ia != ia) && (original_addr == addr)) {
ifa_ref(&ia->ia_ifa);
NET_EPOCH_EXIT(et);
return (ia);
}
}
NET_EPOCH_EXIT(et);
return (NULL);
}
/*
* Tries to find first IPv4 address in the provided fib.
* Prefers non-loopback addresses and return loopback IFF
* @loopback_ok is set.
*
* Returns ifa or NULL.
*/
struct in_ifaddr *
in_findlocal(uint32_t fibnum, bool loopback_ok)
{
struct in_ifaddr *ia = NULL, *ia_lo = NULL;
NET_EPOCH_ASSERT();
CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
uint32_t ia_fib = ia->ia_ifa.ifa_ifp->if_fib;
if (!V_rt_add_addr_allfibs && (fibnum != ia_fib))
continue;
if (!IN_LOOPBACK(ntohl(IA_SIN(ia)->sin_addr.s_addr)))
break;
if (loopback_ok)
ia_lo = ia;
}
if (ia == NULL)
ia = ia_lo;
return (ia);
}
/*
* Determine whether an IP address is in a reserved set of addresses
* that may not be forwarded, or whether datagrams to that destination
* may be forwarded.
*/
int
in_canforward(struct in_addr in)
{
u_long i = ntohl(in.s_addr);
if (IN_MULTICAST(i) || IN_LINKLOCAL(i) || IN_LOOPBACK(i))
return (0);
if (IN_EXPERIMENTAL(i) && !V_ip_allow_net240)
return (0);
if (IN_ZERONET(i) && !V_ip_allow_net0)
return (0);
return (1);
}
/*
* Sysctl to manage prefix of reserved loopback network; translate
* to/from mask. The mask is always contiguous high-order 1 bits
* followed by all 0 bits.
*/
static int
sysctl_loopback_prefixlen(SYSCTL_HANDLER_ARGS)
{
int error, preflen;
/* ffs is 1-based; compensate. */
preflen = 33 - ffs(V_in_loopback_mask);
error = sysctl_handle_int(oidp, &preflen, 0, req);
if (error || !req->newptr)
return (error);
if (preflen < 8 || preflen > 31)
return (EINVAL);
V_in_loopback_mask = 0xffffffff << (32 - preflen);
return (0);
}
/*
* Trim a mask in a sockaddr
*/
static void
in_socktrim(struct sockaddr_in *ap)
{
char *cplim = (char *) &ap->sin_addr;
char *cp = (char *) (&ap->sin_addr + 1);
ap->sin_len = 0;
while (--cp >= cplim)
if (*cp) {
(ap)->sin_len = cp - (char *) (ap) + 1;
break;
}
}
/*
* Generic internet control operations (ioctl's).
*/
int
in_control_ioctl(u_long cmd, void *data, struct ifnet *ifp,
struct ucred *cred)
{
struct ifreq *ifr = (struct ifreq *)data;
struct sockaddr_in *addr = (struct sockaddr_in *)&ifr->ifr_addr;
struct epoch_tracker et;
struct ifaddr *ifa;
struct in_ifaddr *ia;
int error;
if (ifp == NULL)
return (EADDRNOTAVAIL);
/*
* Filter out 4 ioctls we implement directly. Forward the rest
* to specific functions and ifp->if_ioctl().
*/
switch (cmd) {
case SIOCGIFADDR:
case SIOCGIFBRDADDR:
case SIOCGIFDSTADDR:
case SIOCGIFNETMASK:
break;
case SIOCGIFALIAS:
sx_xlock(&in_control_sx);
error = in_gifaddr_ioctl(cmd, data, ifp, cred);
sx_xunlock(&in_control_sx);
return (error);
case SIOCDIFADDR:
sx_xlock(&in_control_sx);
error = in_difaddr_ioctl(cmd, data, ifp, cred);
sx_xunlock(&in_control_sx);
return (error);
case OSIOCAIFADDR: /* 9.x compat */
case SIOCAIFADDR:
sx_xlock(&in_control_sx);
error = in_aifaddr_ioctl(cmd, data, ifp, cred);
sx_xunlock(&in_control_sx);
return (error);
case SIOCSIFADDR:
case SIOCSIFBRDADDR:
case SIOCSIFDSTADDR:
case SIOCSIFNETMASK:
/* We no longer support that old commands. */
return (EINVAL);
default:
if (ifp->if_ioctl == NULL)
return (EOPNOTSUPP);
return ((*ifp->if_ioctl)(ifp, cmd, data));
}
if (addr->sin_addr.s_addr != INADDR_ANY &&
prison_check_ip4(cred, &addr->sin_addr) != 0)
return (EADDRNOTAVAIL);
/*
* Find address for this interface, if it exists. If an
* address was specified, find that one instead of the
* first one on the interface, if possible.
*/
NET_EPOCH_ENTER(et);
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
ia = (struct in_ifaddr *)ifa;
if (ia->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr)
break;
}
if (ifa == NULL)
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
if (ifa->ifa_addr->sa_family == AF_INET) {
ia = (struct in_ifaddr *)ifa;
if (prison_check_ip4(cred,
&ia->ia_addr.sin_addr) == 0)
break;
}
if (ifa == NULL) {
NET_EPOCH_EXIT(et);
return (EADDRNOTAVAIL);
}
error = 0;
switch (cmd) {
case SIOCGIFADDR:
*addr = ia->ia_addr;
break;
case SIOCGIFBRDADDR:
if ((ifp->if_flags & IFF_BROADCAST) == 0) {
error = EINVAL;
break;
}
*addr = ia->ia_broadaddr;
break;
case SIOCGIFDSTADDR:
if ((ifp->if_flags & IFF_POINTOPOINT) == 0) {
error = EINVAL;
break;
}
*addr = ia->ia_dstaddr;
break;
case SIOCGIFNETMASK:
*addr = ia->ia_sockmask;
break;
}
NET_EPOCH_EXIT(et);
return (error);
}
int
in_control(struct socket *so, u_long cmd, void *data, struct ifnet *ifp,
struct thread *td)
{
return (in_control_ioctl(cmd, data, ifp, td ? td->td_ucred : NULL));
}
static int
in_aifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred)
{
const struct in_aliasreq *ifra = (struct in_aliasreq *)data;
const struct sockaddr_in *addr = &ifra->ifra_addr;
const struct sockaddr_in *broadaddr = &ifra->ifra_broadaddr;
const struct sockaddr_in *mask = &ifra->ifra_mask;
const struct sockaddr_in *dstaddr = &ifra->ifra_dstaddr;
const int vhid = (cmd == SIOCAIFADDR) ? ifra->ifra_vhid : 0;
struct epoch_tracker et;
struct ifaddr *ifa;
struct in_ifaddr *ia;
bool iaIsFirst;
int error = 0;
error = priv_check_cred(cred, PRIV_NET_ADDIFADDR);
if (error)
return (error);
/*
* ifra_addr must be present and be of INET family.
* ifra_broadaddr/ifra_dstaddr and ifra_mask are optional.
*/
if (addr->sin_len != sizeof(struct sockaddr_in) ||
addr->sin_family != AF_INET)
return (EINVAL);
if (broadaddr->sin_len != 0 &&
(broadaddr->sin_len != sizeof(struct sockaddr_in) ||
broadaddr->sin_family != AF_INET))
return (EINVAL);
if (mask->sin_len != 0 &&
(mask->sin_len != sizeof(struct sockaddr_in) ||
mask->sin_family != AF_INET))
return (EINVAL);
if ((ifp->if_flags & IFF_POINTOPOINT) &&
(dstaddr->sin_len != sizeof(struct sockaddr_in) ||
dstaddr->sin_addr.s_addr == INADDR_ANY))
return (EDESTADDRREQ);
if (vhid != 0 && carp_attach_p == NULL)
return (EPROTONOSUPPORT);
#ifdef MAC
/* Check if a MAC policy disallows setting the IPv4 address. */
error = mac_inet_check_add_addr(cred, &addr->sin_addr, ifp);
if (error != 0)
return (error);
#endif
/*
* See whether address already exist.
*/
iaIsFirst = true;
ia = NULL;
NET_EPOCH_ENTER(et);
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
struct in_ifaddr *it;
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
it = (struct in_ifaddr *)ifa;
if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
prison_check_ip4(cred, &addr->sin_addr) == 0)
ia = it;
else
iaIsFirst = false;
}
NET_EPOCH_EXIT(et);
if (ia != NULL)
(void )in_difaddr_ioctl(cmd, data, ifp, cred);
ifa = ifa_alloc(sizeof(struct in_ifaddr), M_WAITOK);
ia = (struct in_ifaddr *)ifa;
ifa->ifa_addr = (struct sockaddr *)&ia->ia_addr;
ifa->ifa_dstaddr = (struct sockaddr *)&ia->ia_dstaddr;
ifa->ifa_netmask = (struct sockaddr *)&ia->ia_sockmask;
callout_init_rw(&ia->ia_garp_timer, &ifp->if_addr_lock,
CALLOUT_RETURNUNLOCKED);
ia->ia_ifp = ifp;
ia->ia_addr = *addr;
if (mask->sin_len != 0) {
ia->ia_sockmask = *mask;
ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr);
} else {
in_addr_t i = ntohl(addr->sin_addr.s_addr);
/*
* If netmask isn't supplied, use historical default.
* This is deprecated for interfaces other than loopback
* or point-to-point; warn in other cases. In the future
* we should return an error rather than warning.
*/
if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0)
printf("%s: set address: WARNING: network mask "
"should be specified; using historical default\n",
ifp->if_xname);
if (IN_CLASSA(i))
ia->ia_subnetmask = IN_CLASSA_NET;
else if (IN_CLASSB(i))
ia->ia_subnetmask = IN_CLASSB_NET;
else
ia->ia_subnetmask = IN_CLASSC_NET;
ia->ia_sockmask.sin_addr.s_addr = htonl(ia->ia_subnetmask);
}
ia->ia_subnet = ntohl(addr->sin_addr.s_addr) & ia->ia_subnetmask;
in_socktrim(&ia->ia_sockmask);
if (ifp->if_flags & IFF_BROADCAST) {
if (broadaddr->sin_len != 0) {
ia->ia_broadaddr = *broadaddr;
} else if (ia->ia_subnetmask == IN_RFC3021_MASK) {
ia->ia_broadaddr.sin_addr.s_addr = INADDR_BROADCAST;
ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in);
ia->ia_broadaddr.sin_family = AF_INET;
} else {
ia->ia_broadaddr.sin_addr.s_addr =
htonl(ia->ia_subnet | ~ia->ia_subnetmask);
ia->ia_broadaddr.sin_len = sizeof(struct sockaddr_in);
ia->ia_broadaddr.sin_family = AF_INET;
}
}
if (ifp->if_flags & IFF_POINTOPOINT)
ia->ia_dstaddr = *dstaddr;
if (vhid != 0) {
error = (*carp_attach_p)(&ia->ia_ifa, vhid);
if (error)
return (error);
}
/* if_addrhead is already referenced by ifa_alloc() */
IF_ADDR_WLOCK(ifp);
CK_STAILQ_INSERT_TAIL(&ifp->if_addrhead, ifa, ifa_link);
IF_ADDR_WUNLOCK(ifp);
ifa_ref(ifa); /* in_ifaddrhead */
sx_assert(&in_control_sx, SA_XLOCKED);
CK_STAILQ_INSERT_TAIL(&V_in_ifaddrhead, ia, ia_link);
CK_LIST_INSERT_HEAD(INADDR_HASH(ia->ia_addr.sin_addr.s_addr), ia,
ia_hash);
/*
* Give the interface a chance to initialize
* if this is its first address,
* and to validate the address if necessary.
*/
if (ifp->if_ioctl != NULL) {
error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia);
if (error)
goto fail1;
}
/*
* Add route for the network.
*/
if (vhid == 0) {
error = in_addprefix(ia);
if (error)
goto fail1;
}
/*
* Add a loopback route to self.
*/
if (vhid == 0 && ia_need_loopback_route(ia)) {
struct in_ifaddr *eia;
eia = in_localip_more(ia);
if (eia == NULL) {
error = ifa_add_loopback_route((struct ifaddr *)ia,
(struct sockaddr *)&ia->ia_addr);
if (error)
goto fail2;
} else
ifa_free(&eia->ia_ifa);
}
if (iaIsFirst && (ifp->if_flags & IFF_MULTICAST)) {
struct in_addr allhosts_addr;
struct in_ifinfo *ii;
ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
allhosts_addr.s_addr = htonl(INADDR_ALLHOSTS_GROUP);
error = in_joingroup(ifp, &allhosts_addr, NULL,
&ii->ii_allhosts);
}
/*
* Note: we don't need extra reference for ifa, since we called
* with sx lock held, and ifaddr can not be deleted in concurrent
* thread.
*/
EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, ifa, IFADDR_EVENT_ADD);
return (error);
fail2:
if (vhid == 0)
(void )in_scrubprefix(ia, LLE_STATIC);
fail1:
if (ia->ia_ifa.ifa_carp)
(*carp_detach_p)(&ia->ia_ifa, false);
IF_ADDR_WLOCK(ifp);
CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link);
IF_ADDR_WUNLOCK(ifp);
ifa_free(&ia->ia_ifa); /* if_addrhead */
sx_assert(&in_control_sx, SA_XLOCKED);
CK_STAILQ_REMOVE(&V_in_ifaddrhead, ia, in_ifaddr, ia_link);
CK_LIST_REMOVE(ia, ia_hash);
ifa_free(&ia->ia_ifa); /* in_ifaddrhead */
return (error);
}
static int
in_difaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred)
{
const struct ifreq *ifr = (struct ifreq *)data;
const struct sockaddr_in *addr = (const struct sockaddr_in *)
&ifr->ifr_addr;
struct ifaddr *ifa;
struct in_ifaddr *ia;
bool deleteAny, iaIsLast;
int error;
if (cred != NULL) {
error = priv_check_cred(cred, PRIV_NET_DELIFADDR);
if (error)
return (error);
}
if (addr->sin_len != sizeof(struct sockaddr_in) ||
addr->sin_family != AF_INET)
deleteAny = true;
else
deleteAny = false;
iaIsLast = true;
ia = NULL;
IF_ADDR_WLOCK(ifp);
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
struct in_ifaddr *it;
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
it = (struct in_ifaddr *)ifa;
if (deleteAny && ia == NULL && (cred == NULL ||
prison_check_ip4(cred, &it->ia_addr.sin_addr) == 0))
ia = it;
if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
(cred == NULL || prison_check_ip4(cred,
&addr->sin_addr) == 0))
ia = it;
if (it != ia)
iaIsLast = false;
}
if (ia == NULL) {
IF_ADDR_WUNLOCK(ifp);
return (EADDRNOTAVAIL);
}
CK_STAILQ_REMOVE(&ifp->if_addrhead, &ia->ia_ifa, ifaddr, ifa_link);
IF_ADDR_WUNLOCK(ifp);
ifa_free(&ia->ia_ifa); /* if_addrhead */
sx_assert(&in_control_sx, SA_XLOCKED);
CK_STAILQ_REMOVE(&V_in_ifaddrhead, ia, in_ifaddr, ia_link);
CK_LIST_REMOVE(ia, ia_hash);
/*
* in_scrubprefix() kills the interface route.
*/
in_scrubprefix(ia, LLE_STATIC);
/*
* in_ifadown gets rid of all the rest of
* the routes. This is not quite the right
* thing to do, but at least if we are running
* a routing process they will come back.
*/
in_ifadown(&ia->ia_ifa, 1);
if (ia->ia_ifa.ifa_carp)
(*carp_detach_p)(&ia->ia_ifa, cmd == SIOCAIFADDR);
/*
* If this is the last IPv4 address configured on this
* interface, leave the all-hosts group.
* No state-change report need be transmitted.
*/
if (iaIsLast && (ifp->if_flags & IFF_MULTICAST)) {
struct in_ifinfo *ii;
ii = ((struct in_ifinfo *)ifp->if_afdata[AF_INET]);
if (ii->ii_allhosts) {
(void)in_leavegroup(ii->ii_allhosts, NULL);
ii->ii_allhosts = NULL;
}
}
IF_ADDR_WLOCK(ifp);
if (callout_stop(&ia->ia_garp_timer) == 1) {
ifa_free(&ia->ia_ifa);
}
IF_ADDR_WUNLOCK(ifp);
EVENTHANDLER_INVOKE(ifaddr_event_ext, ifp, &ia->ia_ifa,
IFADDR_EVENT_DEL);
ifa_free(&ia->ia_ifa); /* in_ifaddrhead */
return (0);
}
static int
in_gifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct ucred *cred)
{
struct in_aliasreq *ifra = (struct in_aliasreq *)data;
const struct sockaddr_in *addr = &ifra->ifra_addr;
struct epoch_tracker et;
struct ifaddr *ifa;
struct in_ifaddr *ia;
/*
* ifra_addr must be present and be of INET family.
*/
if (addr->sin_len != sizeof(struct sockaddr_in) ||
addr->sin_family != AF_INET)
return (EINVAL);
/*
* See whether address exist.
*/
ia = NULL;
NET_EPOCH_ENTER(et);
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
struct in_ifaddr *it;
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
it = (struct in_ifaddr *)ifa;
if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
prison_check_ip4(cred, &addr->sin_addr) == 0) {
ia = it;
break;
}
}
if (ia == NULL) {
NET_EPOCH_EXIT(et);
return (EADDRNOTAVAIL);
}
ifra->ifra_mask = ia->ia_sockmask;
if ((ifp->if_flags & IFF_POINTOPOINT) &&
ia->ia_dstaddr.sin_family == AF_INET)
ifra->ifra_dstaddr = ia->ia_dstaddr;
else if ((ifp->if_flags & IFF_BROADCAST) &&
ia->ia_broadaddr.sin_family == AF_INET)
ifra->ifra_broadaddr = ia->ia_broadaddr;
else
memset(&ifra->ifra_broadaddr, 0,
sizeof(ifra->ifra_broadaddr));
NET_EPOCH_EXIT(et);
return (0);
}
static int
in_match_ifaddr(const struct rtentry *rt, const struct nhop_object *nh, void *arg)
{
if (nh->nh_ifa == (struct ifaddr *)arg)
return (1);
return (0);
}
static int
in_handle_prefix_route(uint32_t fibnum, int cmd,
struct sockaddr_in *dst, struct sockaddr_in *netmask, struct ifaddr *ifa,
struct ifnet *ifp)
{
NET_EPOCH_ASSERT();
/* Prepare gateway */
struct sockaddr_dl_short sdl = {
.sdl_family = AF_LINK,
.sdl_len = sizeof(struct sockaddr_dl_short),
.sdl_type = ifa->ifa_ifp->if_type,
.sdl_index = ifa->ifa_ifp->if_index,
};
struct rt_addrinfo info = {
.rti_ifa = ifa,
.rti_ifp = ifp,
.rti_flags = RTF_PINNED | ((netmask != NULL) ? 0 : RTF_HOST),
.rti_info = {
[RTAX_DST] = (struct sockaddr *)dst,
[RTAX_NETMASK] = (struct sockaddr *)netmask,
[RTAX_GATEWAY] = (struct sockaddr *)&sdl,
},
/* Ensure we delete the prefix IFF prefix ifa matches */
.rti_filter = in_match_ifaddr,
.rti_filterdata = ifa,
};
return (rib_handle_ifaddr_info(fibnum, cmd, &info));
}
/*
* Routing table interaction with interface addresses.
*
* In general, two types of routes needs to be installed:
* a) "interface" or "prefix" route, telling user that the addresses
* behind the ifa prefix are reached directly.
* b) "loopback" route installed for the ifa address, telling user that
* the address belongs to local system.
*
* Handling for (a) and (b) differs in multi-fib aspects, hence they
* are implemented in different functions below.
*
* The cases above may intersect - /32 interface aliases results in
* the same prefix produced by (a) and (b). This blurs the definition
* of the "loopback" route and complicate interactions. The interaction
* table is defined below. The case numbers are used in the multiple
* functions below to refer to the particular test case.
*
* There can be multiple options:
* 1) Adding address with prefix on non-p2p/non-loopback interface.
* Example: 192.0.2.1/24. Action:
* * add "prefix" route towards 192.0.2.0/24 via @ia interface,
* using @ia as an address source.
* * add "loopback" route towards 192.0.2.1 via V_loif, saving
* @ia ifp in the gateway and using @ia as an address source.
*
* 2) Adding address with /32 mask to non-p2p/non-loopback interface.
* Example: 192.0.2.2/32. Action:
* * add "prefix" host route via V_loif, using @ia as an address source.
*
* 3) Adding address with or without prefix to p2p interface.
* Example: 10.0.0.1/24->10.0.0.2. Action:
* * add "prefix" host route towards 10.0.0.2 via this interface, using @ia
* as an address source. Note: no sense in installing full /24 as the interface
* is point-to-point.
* * add "loopback" route towards 10.0.9.1 via V_loif, saving
* @ia ifp in the gateway and using @ia as an address source.
*
* 4) Adding address with or without prefix to loopback interface.
* Example: 192.0.2.1/24. Action:
* * add "prefix" host route via @ia interface, using @ia as an address source.
* Note: Skip installing /24 prefix as it would introduce TTL loop
* for the traffic destined to these addresses.
*/
/*
* Checks if @ia needs to install loopback route to @ia address via
* ifa_maintain_loopback_route().
*
* Return true on success.
*/
static bool
ia_need_loopback_route(const struct in_ifaddr *ia)
{
struct ifnet *ifp = ia->ia_ifp;
/* Case 4: Skip loopback interfaces */
if ((ifp->if_flags & IFF_LOOPBACK) ||
(ia->ia_addr.sin_addr.s_addr == INADDR_ANY))
return (false);
/* Clash avoidance: Skip p2p interfaces with both addresses are equal */
if ((ifp->if_flags & IFF_POINTOPOINT) &&
ia->ia_dstaddr.sin_addr.s_addr == ia->ia_addr.sin_addr.s_addr)
return (false);
/* Case 2: skip /32 prefixes */
if (!(ifp->if_flags & IFF_POINTOPOINT) &&
(ia->ia_sockmask.sin_addr.s_addr == INADDR_BROADCAST))
return (false);
return (true);
}
/*
* Calculate "prefix" route corresponding to @ia.
*/
static void
ia_getrtprefix(const struct in_ifaddr *ia, struct in_addr *prefix, struct in_addr *mask)
{
if (ia->ia_ifp->if_flags & IFF_POINTOPOINT) {
/* Case 3: return host route for dstaddr */
*prefix = ia->ia_dstaddr.sin_addr;
mask->s_addr = INADDR_BROADCAST;
} else if (ia->ia_ifp->if_flags & IFF_LOOPBACK) {
/* Case 4: return host route for ifaddr */
*prefix = ia->ia_addr.sin_addr;
mask->s_addr = INADDR_BROADCAST;
} else {
/* Cases 1,2: return actual ia prefix */
*prefix = ia->ia_addr.sin_addr;
*mask = ia->ia_sockmask.sin_addr;
prefix->s_addr &= mask->s_addr;
}
}
/*
* Adds or delete interface "prefix" route corresponding to @ifa.
* Returns 0 on success or errno.
*/
static int
in_handle_ifaddr_route(int cmd, struct in_ifaddr *ia)
{
struct ifaddr *ifa = &ia->ia_ifa;
struct in_addr daddr, maddr;
struct sockaddr_in *pmask;
struct epoch_tracker et;
int error;
ia_getrtprefix(ia, &daddr, &maddr);
struct sockaddr_in mask = {
.sin_family = AF_INET,
.sin_len = sizeof(struct sockaddr_in),
.sin_addr = maddr,
};
pmask = (maddr.s_addr != INADDR_BROADCAST) ? &mask : NULL;
struct sockaddr_in dst = {
.sin_family = AF_INET,
.sin_len = sizeof(struct sockaddr_in),
.sin_addr.s_addr = daddr.s_addr & maddr.s_addr,
};
struct ifnet *ifp = ia->ia_ifp;
if ((maddr.s_addr == INADDR_BROADCAST) &&
(!(ia->ia_ifp->if_flags & (IFF_POINTOPOINT|IFF_LOOPBACK)))) {
/* Case 2: host route on broadcast interface */
ifp = V_loif;
}
uint32_t fibnum = ifa->ifa_ifp->if_fib;
NET_EPOCH_ENTER(et);
error = in_handle_prefix_route(fibnum, cmd, &dst, pmask, ifa, ifp);
NET_EPOCH_EXIT(et);
return (error);
}
/*
* Check if we have a route for the given prefix already.
*/
static bool
in_hasrtprefix(struct in_ifaddr *target)
{
struct epoch_tracker et;
struct in_ifaddr *ia;
struct in_addr prefix, mask, p, m;
bool result = false;
ia_getrtprefix(target, &prefix, &mask);
/* Look for an existing address with the same prefix, mask, and fib */
NET_EPOCH_ENTER(et);
CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
ia_getrtprefix(ia, &p, &m);
if (prefix.s_addr != p.s_addr ||
mask.s_addr != m.s_addr)
continue;
if (target->ia_ifp->if_fib != ia->ia_ifp->if_fib)
continue;
/*
* If we got a matching prefix route inserted by other
* interface address, we are done here.
*/
if (ia->ia_flags & IFA_ROUTE) {
result = true;
break;
}
}
NET_EPOCH_EXIT(et);
return (result);
}
int
in_addprefix(struct in_ifaddr *target)
{
int error;
if (in_hasrtprefix(target)) {
if (V_nosameprefix)
return (EEXIST);
else {
rt_addrmsg(RTM_ADD, &target->ia_ifa,
target->ia_ifp->if_fib);
return (0);
}
}
/*
* No-one seem to have this prefix route, so we try to insert it.
*/
rt_addrmsg(RTM_ADD, &target->ia_ifa, target->ia_ifp->if_fib);
error = in_handle_ifaddr_route(RTM_ADD, target);
if (!error)
target->ia_flags |= IFA_ROUTE;
return (error);
}
/*
* Removes either all lle entries for given @ia, or lle
* corresponding to @ia address.
*/
static void
in_scrubprefixlle(struct in_ifaddr *ia, int all, u_int flags)
{
struct sockaddr_in addr, mask;
struct sockaddr *saddr, *smask;
struct ifnet *ifp;
saddr = (struct sockaddr *)&addr;
bzero(&addr, sizeof(addr));
addr.sin_len = sizeof(addr);
addr.sin_family = AF_INET;
smask = (struct sockaddr *)&mask;
bzero(&mask, sizeof(mask));
mask.sin_len = sizeof(mask);
mask.sin_family = AF_INET;
mask.sin_addr.s_addr = ia->ia_subnetmask;
ifp = ia->ia_ifp;
if (all) {
/*
* Remove all L2 entries matching given prefix.
* Convert address to host representation to avoid
* doing this on every callback. ia_subnetmask is already
* stored in host representation.
*/
addr.sin_addr.s_addr = ntohl(ia->ia_addr.sin_addr.s_addr);
lltable_prefix_free(AF_INET, saddr, smask, flags);
} else {
/* Remove interface address only */
addr.sin_addr.s_addr = ia->ia_addr.sin_addr.s_addr;
lltable_delete_addr(LLTABLE(ifp), LLE_IFADDR, saddr);
}
}
/*
* If there is no other address in the system that can serve a route to the
* same prefix, remove the route. Hand over the route to the new address
* otherwise.
*/
int
in_scrubprefix(struct in_ifaddr *target, u_int flags)
{
struct epoch_tracker et;
struct in_ifaddr *ia;
struct in_addr prefix, mask, p, m;
int error = 0;
/*
* Remove the loopback route to the interface address.
*/
if (ia_need_loopback_route(target) && (flags & LLE_STATIC)) {
struct in_ifaddr *eia;
eia = in_localip_more(target);
if (eia != NULL) {
error = ifa_switch_loopback_route((struct ifaddr *)eia,
(struct sockaddr *)&target->ia_addr);
ifa_free(&eia->ia_ifa);
} else {
error = ifa_del_loopback_route((struct ifaddr *)target,
(struct sockaddr *)&target->ia_addr);
}
}
ia_getrtprefix(target, &prefix, &mask);
if ((target->ia_flags & IFA_ROUTE) == 0) {
rt_addrmsg(RTM_DELETE, &target->ia_ifa, target->ia_ifp->if_fib);
/*
* Removing address from !IFF_UP interface or
* prefix which exists on other interface (along with route).
* No entries should exist here except target addr.
* Given that, delete this entry only.
*/
in_scrubprefixlle(target, 0, flags);
return (0);
}
NET_EPOCH_ENTER(et);
CK_STAILQ_FOREACH(ia, &V_in_ifaddrhead, ia_link) {
ia_getrtprefix(ia, &p, &m);
if (prefix.s_addr != p.s_addr ||
mask.s_addr != m.s_addr)
continue;
if ((ia->ia_ifp->if_flags & IFF_UP) == 0)
continue;
/*
* If we got a matching prefix address, move IFA_ROUTE and
* the route itself to it. Make sure that routing daemons
* get a heads-up.
*/
if ((ia->ia_flags & IFA_ROUTE) == 0) {
ifa_ref(&ia->ia_ifa);
NET_EPOCH_EXIT(et);
error = in_handle_ifaddr_route(RTM_DELETE, target);
if (error == 0)
target->ia_flags &= ~IFA_ROUTE;
else
log(LOG_INFO, "in_scrubprefix: err=%d, old prefix delete failed\n",
error);
/* Scrub all entries IFF interface is different */
in_scrubprefixlle(target, target->ia_ifp != ia->ia_ifp,
flags);
error = in_handle_ifaddr_route(RTM_ADD, ia);
if (error == 0)
ia->ia_flags |= IFA_ROUTE;
else
log(LOG_INFO, "in_scrubprefix: err=%d, new prefix add failed\n",
error);
ifa_free(&ia->ia_ifa);
return (error);
}
}
NET_EPOCH_EXIT(et);
/*
* remove all L2 entries on the given prefix
*/
in_scrubprefixlle(target, 1, flags);
/*
* As no-one seem to have this prefix, we can remove the route.
*/
rt_addrmsg(RTM_DELETE, &target->ia_ifa, target->ia_ifp->if_fib);
error = in_handle_ifaddr_route(RTM_DELETE, target);
if (error == 0)
target->ia_flags &= ~IFA_ROUTE;
else
log(LOG_INFO, "in_scrubprefix: err=%d, prefix delete failed\n", error);
return (error);
}
void
in_ifscrub_all(void)
{
struct ifnet *ifp;
struct ifaddr *ifa, *nifa;
struct ifaliasreq ifr;
IFNET_RLOCK();
CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
/* Cannot lock here - lock recursion. */
/* NET_EPOCH_ENTER(et); */
CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, nifa) {
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
/*
* This is ugly but the only way for legacy IP to
* cleanly remove addresses and everything attached.
*/
bzero(&ifr, sizeof(ifr));
ifr.ifra_addr = *ifa->ifa_addr;
if (ifa->ifa_dstaddr)
ifr.ifra_broadaddr = *ifa->ifa_dstaddr;
(void)in_control(NULL, SIOCDIFADDR, (caddr_t)&ifr,
ifp, NULL);
}
/* NET_EPOCH_EXIT(et); */
in_purgemaddrs(ifp);
igmp_domifdetach(ifp);
}
IFNET_RUNLOCK();
}
int
in_ifaddr_broadcast(struct in_addr in, struct in_ifaddr *ia)
{
return ((in.s_addr == ia->ia_broadaddr.sin_addr.s_addr ||
/*
* Optionally check for old-style (host 0) broadcast, but
* taking into account that RFC 3021 obsoletes it.
*/
(V_broadcast_lowest && ia->ia_subnetmask != IN_RFC3021_MASK &&
ntohl(in.s_addr) == ia->ia_subnet)) &&
/*
* Check for an all one subnetmask. These
* only exist when an interface gets a secondary
* address.
*/
ia->ia_subnetmask != (u_long)0xffffffff);
}
/*
* Return 1 if the address might be a local broadcast address.
*/
int
in_broadcast(struct in_addr in, struct ifnet *ifp)
{
struct ifaddr *ifa;
int found;
NET_EPOCH_ASSERT();
if (in.s_addr == INADDR_BROADCAST ||
in.s_addr == INADDR_ANY)
return (1);
if ((ifp->if_flags & IFF_BROADCAST) == 0)
return (0);
found = 0;
/*
* Look through the list of addresses for a match
* with a broadcast address.
*/
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
if (ifa->ifa_addr->sa_family == AF_INET &&
in_ifaddr_broadcast(in, (struct in_ifaddr *)ifa)) {
found = 1;
break;
}
return (found);
}
/*
* On interface removal, clean up IPv4 data structures hung off of the ifnet.
*/
void
in_ifdetach(struct ifnet *ifp)
{
IN_MULTI_LOCK();
in_pcbpurgeif0(&V_ripcbinfo, ifp);
in_pcbpurgeif0(&V_udbinfo, ifp);
in_pcbpurgeif0(&V_ulitecbinfo, ifp);
in_purgemaddrs(ifp);
IN_MULTI_UNLOCK();
/*
* Make sure all multicast deletions invoking if_ioctl() are
* completed before returning. Else we risk accessing a freed
* ifnet structure pointer.
*/
inm_release_wait(NULL);
}
static void
in_ifnet_event(void *arg __unused, struct ifnet *ifp, int event)
{
struct epoch_tracker et;
struct ifaddr *ifa;
struct in_ifaddr *ia;
int error;
NET_EPOCH_ENTER(et);
switch (event) {
case IFNET_EVENT_DOWN:
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
ia = (struct in_ifaddr *)ifa;
if ((ia->ia_flags & IFA_ROUTE) == 0)
continue;
ifa_ref(ifa);
/*
* in_scrubprefix() kills the interface route.
*/
in_scrubprefix(ia, 0);
/*
* in_ifadown gets rid of all the rest of the
* routes. This is not quite the right thing
* to do, but at least if we are running a
* routing process they will come back.
*/
in_ifadown(ifa, 0);
ifa_free(ifa);
}
break;
case IFNET_EVENT_UP:
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
ia = (struct in_ifaddr *)ifa;
if (ia->ia_flags & IFA_ROUTE)
continue;
ifa_ref(ifa);
error = ifa_del_loopback_route(ifa, ifa->ifa_addr);
rt_addrmsg(RTM_ADD, ifa, ifa->ifa_ifp->if_fib);
error = in_handle_ifaddr_route(RTM_ADD, ia);
if (error == 0)
ia->ia_flags |= IFA_ROUTE;
error = ifa_add_loopback_route(ifa, ifa->ifa_addr);
ifa_free(ifa);
}
break;
}
NET_EPOCH_EXIT(et);
}
EVENTHANDLER_DEFINE(ifnet_event, in_ifnet_event, NULL, EVENTHANDLER_PRI_ANY);
/*
* Delete all IPv4 multicast address records, and associated link-layer
* multicast address records, associated with ifp.
* XXX It looks like domifdetach runs AFTER the link layer cleanup.
* XXX This should not race with ifma_protospec being set during
* a new allocation, if it does, we have bigger problems.
*/
static void
in_purgemaddrs(struct ifnet *ifp)
{
struct epoch_tracker et;
struct in_multi_head purgeinms;
struct in_multi *inm;
struct ifmultiaddr *ifma;
SLIST_INIT(&purgeinms);
IN_MULTI_LIST_LOCK();
/*
* Extract list of in_multi associated with the detaching ifp
* which the PF_INET layer is about to release.
* We need to do this as IF_ADDR_LOCK() may be re-acquired
* by code further down.
*/
IF_ADDR_WLOCK(ifp);
NET_EPOCH_ENTER(et);
CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
inm = inm_ifmultiaddr_get_inm(ifma);
if (inm == NULL)
continue;
inm_rele_locked(&purgeinms, inm);
}
NET_EPOCH_EXIT(et);
IF_ADDR_WUNLOCK(ifp);
inm_release_list_deferred(&purgeinms);
igmp_ifdetach(ifp);
IN_MULTI_LIST_UNLOCK();
}
struct in_llentry {
struct llentry base;
};
#define IN_LLTBL_DEFAULT_HSIZE 32
#define IN_LLTBL_HASH(k, h) \
(((((((k >> 8) ^ k) >> 8) ^ k) >> 8) ^ k) & ((h) - 1))
/*
* Do actual deallocation of @lle.
*/
static void
in_lltable_destroy_lle_unlocked(epoch_context_t ctx)
{
struct llentry *lle;
lle = __containerof(ctx, struct llentry, lle_epoch_ctx);
LLE_LOCK_DESTROY(lle);
LLE_REQ_DESTROY(lle);
free(lle, M_LLTABLE);
}
/*
* Called by LLE_FREE_LOCKED when number of references
* drops to zero.
*/
static void
in_lltable_destroy_lle(struct llentry *lle)
{
LLE_WUNLOCK(lle);
NET_EPOCH_CALL(in_lltable_destroy_lle_unlocked, &lle->lle_epoch_ctx);
}
static struct llentry *
in_lltable_new(struct in_addr addr4, u_int flags)
{
struct in_llentry *lle;
lle = malloc(sizeof(struct in_llentry), M_LLTABLE, M_NOWAIT | M_ZERO);
if (lle == NULL) /* NB: caller generates msg */
return NULL;
/*
* For IPv4 this will trigger "arpresolve" to generate
* an ARP request.
*/
lle->base.la_expire = time_uptime; /* mark expired */
lle->base.r_l3addr.addr4 = addr4;
lle->base.lle_refcnt = 1;
lle->base.lle_free = in_lltable_destroy_lle;
LLE_LOCK_INIT(&lle->base);
LLE_REQ_INIT(&lle->base);
callout_init(&lle->base.lle_timer, 1);
return (&lle->base);
}
#define IN_ARE_MASKED_ADDR_EQUAL(d, a, m) ( \
((((d).s_addr ^ (a).s_addr) & (m).s_addr)) == 0 )
static int
in_lltable_match_prefix(const struct sockaddr *saddr,
const struct sockaddr *smask, u_int flags, struct llentry *lle)
{
struct in_addr addr, mask, lle_addr;
addr = ((const struct sockaddr_in *)saddr)->sin_addr;
mask = ((const struct sockaddr_in *)smask)->sin_addr;
lle_addr.s_addr = ntohl(lle->r_l3addr.addr4.s_addr);
if (IN_ARE_MASKED_ADDR_EQUAL(lle_addr, addr, mask) == 0)
return (0);
if (lle->la_flags & LLE_IFADDR) {
/*
* Delete LLE_IFADDR records IFF address & flag matches.
* Note that addr is the interface address within prefix
* being matched.
* Note also we should handle 'ifdown' cases without removing
* ifaddr macs.
*/
if (addr.s_addr == lle_addr.s_addr && (flags & LLE_STATIC) != 0)
return (1);
return (0);
}
/* flags & LLE_STATIC means deleting both dynamic and static entries */
if ((flags & LLE_STATIC) || !(lle->la_flags & LLE_STATIC))
return (1);
return (0);
}
static void
in_lltable_free_entry(struct lltable *llt, struct llentry *lle)
{
size_t pkts_dropped;
LLE_WLOCK_ASSERT(lle);
KASSERT(llt != NULL, ("lltable is NULL"));
/* Unlink entry from table if not already */
if ((lle->la_flags & LLE_LINKED) != 0) {
IF_AFDATA_WLOCK_ASSERT(llt->llt_ifp);
lltable_unlink_entry(llt, lle);
}
/* Drop hold queue */
pkts_dropped = llentry_free(lle);
ARPSTAT_ADD(dropped, pkts_dropped);
}
static int
in_lltable_rtcheck(struct ifnet *ifp, u_int flags, const struct sockaddr *l3addr)
{
struct nhop_object *nh;
struct in_addr addr;
KASSERT(l3addr->sa_family == AF_INET,
("sin_family %d", l3addr->sa_family));
addr = ((const struct sockaddr_in *)l3addr)->sin_addr;
nh = fib4_lookup(ifp->if_fib, addr, 0, NHR_NONE, 0);
if (nh == NULL)
return (EINVAL);
/*
* If the gateway for an existing host route matches the target L3
* address, which is a special route inserted by some implementation
* such as MANET, and the interface is of the correct type, then
* allow for ARP to proceed.
*/
if (nh->nh_flags & NHF_GATEWAY) {
if (!(nh->nh_flags & NHF_HOST) || nh->nh_ifp->if_type != IFT_ETHER ||
(nh->nh_ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) != 0 ||
memcmp(nh->gw_sa.sa_data, l3addr->sa_data,
sizeof(in_addr_t)) != 0) {
return (EINVAL);
}
}
/*
* Make sure that at least the destination address is covered
* by the route. This is for handling the case where 2 or more
* interfaces have the same prefix. An incoming packet arrives
* on one interface and the corresponding outgoing packet leaves
* another interface.
*/
if ((nh->nh_ifp != ifp) && (nh->nh_flags & NHF_HOST) == 0) {
struct in_ifaddr *ia = (struct in_ifaddr *)ifaof_ifpforaddr(l3addr, ifp);
struct in_addr dst_addr, mask_addr;
if (ia == NULL)
return (EINVAL);
/*
* ifaof_ifpforaddr() returns _best matching_ IFA.
* It is possible that ifa prefix does not cover our address.
* Explicitly verify and fail if that's the case.
*/
dst_addr = IA_SIN(ia)->sin_addr;
mask_addr.s_addr = htonl(ia->ia_subnetmask);
if (!IN_ARE_MASKED_ADDR_EQUAL(dst_addr, addr, mask_addr))
return (EINVAL);
}
return (0);
}
static inline uint32_t
in_lltable_hash_dst(const struct in_addr dst, uint32_t hsize)
{
return (IN_LLTBL_HASH(dst.s_addr, hsize));
}
static uint32_t
in_lltable_hash(const struct llentry *lle, uint32_t hsize)
{
return (in_lltable_hash_dst(lle->r_l3addr.addr4, hsize));
}
static void
in_lltable_fill_sa_entry(const struct llentry *lle, struct sockaddr *sa)
{
struct sockaddr_in *sin;
sin = (struct sockaddr_in *)sa;
bzero(sin, sizeof(*sin));
sin->sin_family = AF_INET;
sin->sin_len = sizeof(*sin);
sin->sin_addr = lle->r_l3addr.addr4;
}
static inline struct llentry *
in_lltable_find_dst(struct lltable *llt, struct in_addr dst)
{
struct llentry *lle;
struct llentries *lleh;
u_int hashidx;
hashidx = in_lltable_hash_dst(dst, llt->llt_hsize);
lleh = &llt->lle_head[hashidx];
CK_LIST_FOREACH(lle, lleh, lle_next) {
if (lle->la_flags & LLE_DELETED)
continue;
if (lle->r_l3addr.addr4.s_addr == dst.s_addr)
break;
}
return (lle);
}
static void
in_lltable_delete_entry(struct lltable *llt, struct llentry *lle)
{
lle->la_flags |= LLE_DELETED;
EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_DELETED);
#ifdef DIAGNOSTIC
log(LOG_INFO, "ifaddr cache = %p is deleted\n", lle);
#endif
llentry_free(lle);
}
static struct llentry *
in_lltable_alloc(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
{
const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
struct ifnet *ifp = llt->llt_ifp;
struct llentry *lle;
char linkhdr[LLE_MAX_LINKHDR];
size_t linkhdrsize;
int lladdr_off;
KASSERT(l3addr->sa_family == AF_INET,
("sin_family %d", l3addr->sa_family));
/*
* A route that covers the given address must have
* been installed 1st because we are doing a resolution,
* verify this.
*/
if (!(flags & LLE_IFADDR) &&
in_lltable_rtcheck(ifp, flags, l3addr) != 0)
return (NULL);
lle = in_lltable_new(sin->sin_addr, flags);
if (lle == NULL) {
log(LOG_INFO, "lla_lookup: new lle malloc failed\n");
return (NULL);
}
lle->la_flags = flags;
if (flags & LLE_STATIC)
lle->r_flags |= RLLE_VALID;
if ((flags & LLE_IFADDR) == LLE_IFADDR) {
linkhdrsize = LLE_MAX_LINKHDR;
if (lltable_calc_llheader(ifp, AF_INET, IF_LLADDR(ifp),
linkhdr, &linkhdrsize, &lladdr_off) != 0) {
in_lltable_free_entry(llt, lle);
return (NULL);
}
lltable_set_entry_addr(ifp, lle, linkhdr, linkhdrsize,
lladdr_off);
lle->la_flags |= LLE_STATIC;
lle->r_flags |= (RLLE_VALID | RLLE_IFADDR);
lle->la_expire = 0;
}
return (lle);
}
/*
* Return NULL if not found or marked for deletion.
* If found return lle read locked.
*/
static struct llentry *
in_lltable_lookup(struct lltable *llt, u_int flags, const struct sockaddr *l3addr)
{
const struct sockaddr_in *sin = (const struct sockaddr_in *)l3addr;
struct llentry *lle;
IF_AFDATA_LOCK_ASSERT(llt->llt_ifp);
KASSERT(l3addr->sa_family == AF_INET,
("sin_family %d", l3addr->sa_family));
KASSERT((flags & (LLE_UNLOCKED | LLE_EXCLUSIVE)) !=
(LLE_UNLOCKED | LLE_EXCLUSIVE),
("wrong lle request flags: %#x", flags));
lle = in_lltable_find_dst(llt, sin->sin_addr);
if (lle == NULL)
return (NULL);
if (flags & LLE_UNLOCKED)
return (lle);
if (flags & LLE_EXCLUSIVE)
LLE_WLOCK(lle);
else
LLE_RLOCK(lle);
/*
* If the afdata lock is not held, the LLE may have been unlinked while
* we were blocked on the LLE lock. Check for this case.
*/
if (__predict_false((lle->la_flags & LLE_LINKED) == 0)) {
if (flags & LLE_EXCLUSIVE)
LLE_WUNLOCK(lle);
else
LLE_RUNLOCK(lle);
return (NULL);
}
return (lle);
}
static int
in_lltable_dump_entry(struct lltable *llt, struct llentry *lle,
struct sysctl_req *wr)
{
struct ifnet *ifp = llt->llt_ifp;
/* XXX stack use */
struct {
struct rt_msghdr rtm;
struct sockaddr_in sin;
struct sockaddr_dl sdl;
} arpc;
struct sockaddr_dl *sdl;
int error;
bzero(&arpc, sizeof(arpc));
/* skip deleted entries */
if ((lle->la_flags & LLE_DELETED) == LLE_DELETED)
return (0);
/* Skip if jailed and not a valid IP of the prison. */
lltable_fill_sa_entry(lle,(struct sockaddr *)&arpc.sin);
if (prison_if(wr->td->td_ucred, (struct sockaddr *)&arpc.sin) != 0)
return (0);
/*
* produce a msg made of:
* struct rt_msghdr;
* struct sockaddr_in; (IPv4)
* struct sockaddr_dl;
*/
arpc.rtm.rtm_msglen = sizeof(arpc);
arpc.rtm.rtm_version = RTM_VERSION;
arpc.rtm.rtm_type = RTM_GET;
arpc.rtm.rtm_flags = RTF_UP;
arpc.rtm.rtm_addrs = RTA_DST | RTA_GATEWAY;
/* publish */
if (lle->la_flags & LLE_PUB)
arpc.rtm.rtm_flags |= RTF_ANNOUNCE;
sdl = &arpc.sdl;
sdl->sdl_family = AF_LINK;
sdl->sdl_len = sizeof(*sdl);
sdl->sdl_index = ifp->if_index;
sdl->sdl_type = ifp->if_type;
if ((lle->la_flags & LLE_VALID) == LLE_VALID) {
sdl->sdl_alen = ifp->if_addrlen;
bcopy(lle->ll_addr, LLADDR(sdl), ifp->if_addrlen);
} else {
sdl->sdl_alen = 0;
bzero(LLADDR(sdl), ifp->if_addrlen);
}
arpc.rtm.rtm_rmx.rmx_expire =
lle->la_flags & LLE_STATIC ? 0 : lle->la_expire;
arpc.rtm.rtm_flags |= (RTF_HOST | RTF_LLDATA);
if (lle->la_flags & LLE_STATIC)
arpc.rtm.rtm_flags |= RTF_STATIC;
if (lle->la_flags & LLE_IFADDR)
arpc.rtm.rtm_flags |= RTF_PINNED;
arpc.rtm.rtm_index = ifp->if_index;
error = SYSCTL_OUT(wr, &arpc, sizeof(arpc));
return (error);
}
static void
in_lltable_post_resolved(struct lltable *llt, struct llentry *lle)
{
struct ifnet *ifp = llt->llt_ifp;
/* gratuitous ARP */
if ((lle->la_flags & LLE_PUB) != 0)
arprequest(ifp, &lle->r_l3addr.addr4, &lle->r_l3addr.addr4,
lle->ll_addr);
}
static struct lltable *
in_lltattach(struct ifnet *ifp)
{
struct lltable *llt;
llt = lltable_allocate_htbl(IN_LLTBL_DEFAULT_HSIZE);
llt->llt_af = AF_INET;
llt->llt_ifp = ifp;
llt->llt_lookup = in_lltable_lookup;
llt->llt_alloc_entry = in_lltable_alloc;
llt->llt_delete_entry = in_lltable_delete_entry;
llt->llt_dump_entry = in_lltable_dump_entry;
llt->llt_hash = in_lltable_hash;
llt->llt_fill_sa_entry = in_lltable_fill_sa_entry;
llt->llt_free_entry = in_lltable_free_entry;
llt->llt_match_prefix = in_lltable_match_prefix;
llt->llt_mark_used = llentry_mark_used;
llt->llt_post_resolved = in_lltable_post_resolved;
lltable_link(llt);
return (llt);
}
struct lltable *
in_lltable_get(struct ifnet *ifp)
{
struct lltable *llt = NULL;
void *afdata_ptr = ifp->if_afdata[AF_INET];
if (afdata_ptr != NULL)
llt = ((struct in_ifinfo *)afdata_ptr)->ii_llt;
return (llt);
}
void *
in_domifattach(struct ifnet *ifp)
{
struct in_ifinfo *ii;
ii = malloc(sizeof(struct in_ifinfo), M_IFADDR, M_WAITOK|M_ZERO);
ii->ii_llt = in_lltattach(ifp);
ii->ii_igmp = igmp_domifattach(ifp);
return (ii);
}
void
in_domifdetach(struct ifnet *ifp, void *aux)
{
struct in_ifinfo *ii = (struct in_ifinfo *)aux;
igmp_domifdetach(ifp);
lltable_free(ii->ii_llt);
free(ii, M_IFADDR);
}
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