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in.c
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in.c
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/*-
* 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_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>
static int in_aifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct thread *);
static int in_difaddr_ioctl(u_long, caddr_t, struct ifnet *, struct thread *);
static int in_gifaddr_ioctl(u_long, caddr_t, struct ifnet *, struct thread *);
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(struct socket *so, u_long cmd, void *data, struct ifnet *ifp,
struct thread *td)
{
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, td);
sx_xunlock(&in_control_sx);
return (error);
case SIOCDIFADDR:
sx_xlock(&in_control_sx);
error = in_difaddr_ioctl(cmd, data, ifp, td);
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, td);
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(td->td_ucred, &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(td->td_ucred,
&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);
}
static int
in_aifaddr_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp, struct thread *td)
{
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(td, 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);
/*
* 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(td->td_ucred, &addr->sin_addr) == 0)
ia = it;
else
iaIsFirst = false;
}
NET_EPOCH_EXIT(et);
if (ia != NULL)
(void )in_difaddr_ioctl(cmd, data, ifp, td);
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 thread *td)
{
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 (td != NULL) {
error = priv_check(td, 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 && (td == NULL ||
prison_check_ip4(td->td_ucred, &it->ia_addr.sin_addr) == 0))
ia = it;
if (it->ia_addr.sin_addr.s_addr == addr->sin_addr.s_addr &&
(td == NULL || prison_check_ip4(td->td_ucred,
&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 thread *td)
{
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(td->td_ucred, &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.
*/