/*-
* Copyright (c) 1998 Brian Somers <brian@Awfulhak.org>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD: src/usr.sbin/ppp/iface.c,v 1.38.24.1 2010/12/21 17:10:29 kensmith Exp $
*/
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <net/if.h>
#include <net/if_dl.h>
#ifdef __FreeBSD__
#include <net/if_var.h>
#endif
#include <net/route.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#ifndef NOINET6
#include <netinet6/nd6.h>
#endif
#include <sys/un.h>
#include <errno.h>
#include <string.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/sysctl.h>
#include <termios.h>
#include <unistd.h>
#include "layer.h"
#include "defs.h"
#include "command.h"
#include "mbuf.h"
#include "log.h"
#include "id.h"
#include "timer.h"
#include "fsm.h"
#include "iplist.h"
#include "lqr.h"
#include "hdlc.h"
#include "throughput.h"
#include "slcompress.h"
#include "descriptor.h"
#include "ncpaddr.h"
#include "ipcp.h"
#include "filter.h"
#include "lcp.h"
#include "ccp.h"
#include "link.h"
#include "mp.h"
#ifndef NORADIUS
#include "radius.h"
#endif
#include "ipv6cp.h"
#include "ncp.h"
#include "bundle.h"
#include "prompt.h"
#include "iface.h"
#define IN6MASK128 {{{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, \
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }}}
static const struct in6_addr in6mask128 = IN6MASK128;
struct iface *
iface_Create(const char *name)
{
int mib[6], maxtries, err;
size_t needed, namelen;
char *buf, *ptr, *end;
struct if_msghdr *ifm;
struct ifa_msghdr *ifam;
struct sockaddr_dl *dl;
struct sockaddr *sa[RTAX_MAX];
struct iface *iface;
struct iface_addr *addr;
mib[0] = CTL_NET;
mib[1] = PF_ROUTE;
mib[2] = 0;
mib[3] = 0;
mib[4] = NET_RT_IFLIST;
mib[5] = 0;
maxtries = 20;
err = 0;
do {
if (maxtries-- == 0 || (err && err != ENOMEM)) {
fprintf(stderr, "iface_Create: sysctl: %s\n", strerror(err));
return NULL;
}
if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) {
fprintf(stderr, "iface_Create: sysctl: estimate: %s\n",
strerror(errno));
return NULL;
}
if ((buf = (char *)malloc(needed)) == NULL) {
fprintf(stderr, "iface_Create: malloc failed: %s\n", strerror(errno));
return NULL;
}
if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
err = errno;
free(buf);
buf = NULL;
}
} while (buf == NULL);
ptr = buf;
end = buf + needed;
iface = NULL;
namelen = strlen(name);
while (ptr < end && iface == NULL) {
ifm = (struct if_msghdr *)ptr; /* On if_msghdr */
if (ifm->ifm_type != RTM_IFINFO)
break;
dl = (struct sockaddr_dl *)(ifm + 1); /* Single _dl at end */
if (dl->sdl_nlen == namelen && !strncmp(name, dl->sdl_data, namelen)) {
iface = (struct iface *)malloc(sizeof *iface);
if (iface == NULL) {
fprintf(stderr, "iface_Create: malloc: %s\n", strerror(errno));
return NULL;
}
iface->name = strdup(name);
iface->index = ifm->ifm_index;
iface->flags = ifm->ifm_flags;
iface->mtu = 0;
iface->addrs = 0;
iface->addr = NULL;
}
ptr += ifm->ifm_msglen; /* First ifa_msghdr */
for (; ptr < end; ptr += ifam->ifam_msglen) {
ifam = (struct ifa_msghdr *)ptr; /* Next if address */
if (ifam->ifam_type != RTM_NEWADDR) /* finished this if */
break;
if (iface != NULL && ifam->ifam_addrs & RTA_IFA) {
/* Found a configured interface ! */
iface_ParseHdr(ifam, sa);
if (sa[RTAX_IFA] && (sa[RTAX_IFA]->sa_family == AF_INET
#ifndef NOINET6
|| sa[RTAX_IFA]->sa_family == AF_INET6
#endif
)) {
/* Record the address */
addr = (struct iface_addr *)
realloc(iface->addr, (iface->addrs + 1) * sizeof iface->addr[0]);
if (addr == NULL)
break;
iface->addr = addr;
addr += iface->addrs;
iface->addrs++;
ncprange_setsa(&addr->ifa, sa[RTAX_IFA], sa[RTAX_NETMASK]);
if (sa[RTAX_BRD])
ncpaddr_setsa(&addr->peer, sa[RTAX_BRD]);
else
ncpaddr_init(&addr->peer);
}
}
}
}
free(buf);
return iface;
}
static int
iface_addr_Zap(const char *name, struct iface_addr *addr, int s)
{
struct ifaliasreq ifra;
#ifndef NOINET6
struct in6_aliasreq ifra6;
#endif
struct sockaddr_in *me4, *msk4, *peer4;
struct sockaddr_storage ssme, sspeer, ssmsk;
int res;
ncprange_getsa(&addr->ifa, &ssme, &ssmsk);
ncpaddr_getsa(&addr->peer, &sspeer);
res = 0;
switch (ncprange_family(&addr->ifa)) {
case AF_INET:
memset(&ifra, '\0', sizeof ifra);
strncpy(ifra.ifra_name, name, sizeof ifra.ifra_name - 1);
me4 = (struct sockaddr_in *)&ifra.ifra_addr;
memcpy(me4, &ssme, sizeof *me4);
msk4 = (struct sockaddr_in *)&ifra.ifra_mask;
memcpy(msk4, &ssmsk, sizeof *msk4);
peer4 = (struct sockaddr_in *)&ifra.ifra_broadaddr;
if (ncpaddr_family(&addr->peer) == AF_UNSPEC) {
peer4->sin_family = AF_INET;
peer4->sin_len = sizeof(*peer4);
peer4->sin_addr.s_addr = INADDR_NONE;
} else
memcpy(peer4, &sspeer, sizeof *peer4);
res = ID0ioctl(s, SIOCDIFADDR, &ifra);
if (log_IsKept(LogDEBUG)) {
char buf[100];
snprintf(buf, sizeof buf, "%s", ncprange_ntoa(&addr->ifa));
log_Printf(LogWARN, "%s: DIFADDR %s -> %s returns %d\n",
ifra.ifra_name, buf, ncpaddr_ntoa(&addr->peer), res);
}
break;
#ifndef NOINET6
case AF_INET6:
memset(&ifra6, '\0', sizeof ifra6);
strncpy(ifra6.ifra_name, name, sizeof ifra6.ifra_name - 1);
memcpy(&ifra6.ifra_addr, &ssme, sizeof ifra6.ifra_addr);
memcpy(&ifra6.ifra_prefixmask, &ssmsk, sizeof ifra6.ifra_prefixmask);
ifra6.ifra_prefixmask.sin6_family = AF_UNSPEC;
if (ncpaddr_family(&addr->peer) == AF_UNSPEC)
ifra6.ifra_dstaddr.sin6_family = AF_UNSPEC;
else
memcpy(&ifra6.ifra_dstaddr, &sspeer, sizeof ifra6.ifra_dstaddr);
ifra6.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
ifra6.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
res = ID0ioctl(s, SIOCDIFADDR_IN6, &ifra6);
break;
#endif
}
if (res == -1) {
char dst[40];
const char *end =
#ifndef NOINET6
ncprange_family(&addr->ifa) == AF_INET6 ? "_IN6" :
#endif
"";
if (ncpaddr_family(&addr->peer) == AF_UNSPEC)
log_Printf(LogWARN, "iface rm: ioctl(SIOCDIFADDR%s, %s): %s\n",
end, ncprange_ntoa(&addr->ifa), strerror(errno));
else {
snprintf(dst, sizeof dst, "%s", ncpaddr_ntoa(&addr->peer));
log_Printf(LogWARN, "iface rm: ioctl(SIOCDIFADDR%s, %s -> %s): %s\n",
end, ncprange_ntoa(&addr->ifa), dst, strerror(errno));
}
}
return res != -1;
}
static int
iface_addr_Add(const char *name, struct iface_addr *addr, int s)
{
struct ifaliasreq ifra;
#ifndef NOINET6
struct in6_aliasreq ifra6;
#endif
struct sockaddr_in *me4, *msk4, *peer4;
struct sockaddr_storage ssme, sspeer, ssmsk;
int res;
ncprange_getsa(&addr->ifa, &ssme, &ssmsk);
ncpaddr_getsa(&addr->peer, &sspeer);
res = 0;
switch (ncprange_family(&addr->ifa)) {
case AF_INET:
memset(&ifra, '\0', sizeof ifra);
strncpy(ifra.ifra_name, name, sizeof ifra.ifra_name - 1);
me4 = (struct sockaddr_in *)&ifra.ifra_addr;
memcpy(me4, &ssme, sizeof *me4);
msk4 = (struct sockaddr_in *)&ifra.ifra_mask;
memcpy(msk4, &ssmsk, sizeof *msk4);
peer4 = (struct sockaddr_in *)&ifra.ifra_broadaddr;
if (ncpaddr_family(&addr->peer) == AF_UNSPEC) {
peer4->sin_family = AF_INET;
peer4->sin_len = sizeof(*peer4);
peer4->sin_addr.s_addr = INADDR_NONE;
} else
memcpy(peer4, &sspeer, sizeof *peer4);
res = ID0ioctl(s, SIOCAIFADDR, &ifra);
if (log_IsKept(LogDEBUG)) {
char buf[100];
snprintf(buf, sizeof buf, "%s", ncprange_ntoa(&addr->ifa));
log_Printf(LogWARN, "%s: AIFADDR %s -> %s returns %d\n",
ifra.ifra_name, buf, ncpaddr_ntoa(&addr->peer), res);
}
break;
#ifndef NOINET6
case AF_INET6:
memset(&ifra6, '\0', sizeof ifra6);
strncpy(ifra6.ifra_name, name, sizeof ifra6.ifra_name - 1);
memcpy(&ifra6.ifra_addr, &ssme, sizeof ifra6.ifra_addr);
memcpy(&ifra6.ifra_prefixmask, &ssmsk, sizeof ifra6.ifra_prefixmask);
if (ncpaddr_family(&addr->peer) == AF_UNSPEC)
ifra6.ifra_dstaddr.sin6_family = AF_UNSPEC;
else if (memcmp(&((struct sockaddr_in6 *)&ssmsk)->sin6_addr, &in6mask128,
sizeof in6mask128) == 0)
memcpy(&ifra6.ifra_dstaddr, &sspeer, sizeof ifra6.ifra_dstaddr);
ifra6.ifra_lifetime.ia6t_vltime = ND6_INFINITE_LIFETIME;
ifra6.ifra_lifetime.ia6t_pltime = ND6_INFINITE_LIFETIME;
res = ID0ioctl(s, SIOCAIFADDR_IN6, &ifra6);
break;
#endif
}
if (res == -1) {
char dst[40];
const char *end =
#ifndef NOINET6
ncprange_family(&addr->ifa) == AF_INET6 ? "_IN6" :
#endif
"";
if (ncpaddr_family(&addr->peer) == AF_UNSPEC)
log_Printf(LogWARN, "iface add: ioctl(SIOCAIFADDR%s, %s): %s\n",
end, ncprange_ntoa(&addr->ifa), strerror(errno));
else {
snprintf(dst, sizeof dst, "%s", ncpaddr_ntoa(&addr->peer));
log_Printf(LogWARN, "iface add: ioctl(SIOCAIFADDR%s, %s -> %s): %s\n",
end, ncprange_ntoa(&addr->ifa), dst, strerror(errno));
}
}
return res != -1;
}
void
iface_Clear(struct iface *iface, struct ncp *ncp, int family, int how)
{
int addrs, af, inskip, in6skip, s4 = -1, s6 = -1, *s;
unsigned n;
if (iface->addrs) {
inskip = in6skip = how == IFACE_CLEAR_ALL ? 0 : 1;
addrs = 0;
for (n = 0; n < iface->addrs; n++) {
af = ncprange_family(&iface->addr[n].ifa);
if (family == 0 || family == af) {
if (!iface->addr[n].system && (how & IFACE_SYSTEM))
continue;
switch (af) {
case AF_INET:
if (inskip) {
inskip = 0;
continue;
}
s = &s4;
break;
#ifndef NOINET6
case AF_INET6:
if (in6skip) {
in6skip = 0;
continue;
}
s = &s6;
break;
#endif
default:
continue;
}
if (*s == -1 && (*s = ID0socket(af, SOCK_DGRAM, 0)) == -1)
log_Printf(LogERROR, "iface_Clear: socket(): %s\n", strerror(errno));
else if (iface_addr_Zap(iface->name, iface->addr + n, *s)) {
ncp_IfaceAddrDeleted(ncp, iface->addr + n);
bcopy(iface->addr + n + 1, iface->addr + n,
(iface->addrs - n - 1) * sizeof *iface->addr);
iface->addrs--;
n--;
}
}
}
/* Don't bother realloc()ing - we have little to gain */
if (s4)
close(s4);
if (s6)
close(s6);
}
}
int
iface_Add(struct iface *iface, struct ncp *ncp, const struct ncprange *ifa,
const struct ncpaddr *peer, int how)
{
int af, removed, s;
unsigned n;
struct ncpaddr ncplocal;
struct iface_addr *addr, newaddr;
af = ncprange_family(ifa);
if ((s = ID0socket(af, SOCK_DGRAM, 0)) == -1) {
log_Printf(LogERROR, "iface_Add: socket(): %s\n", strerror(errno));
return 0;
}
ncprange_getaddr(ifa, &ncplocal);
for (n = 0; n < iface->addrs; n++) {
if (ncprange_contains(&iface->addr[n].ifa, &ncplocal) ||
ncpaddr_equal(&iface->addr[n].peer, peer)) {
/* Replace this sockaddr */
if (!(how & IFACE_FORCE_ADD)) {
close(s);
return 0; /* errno = EEXIST; */
}
if (ncprange_equal(&iface->addr[n].ifa, ifa) &&
ncpaddr_equal(&iface->addr[n].peer, peer)) {
close(s);
return 1; /* Already there */
}
removed = iface_addr_Zap(iface->name, iface->addr + n, s);
if (removed)
ncp_IfaceAddrDeleted(ncp, iface->addr + n);
ncprange_copy(&iface->addr[n].ifa, ifa);
ncpaddr_copy(&iface->addr[n].peer, peer);
if (!iface_addr_Add(iface->name, iface->addr + n, s)) {
if (removed) {
bcopy(iface->addr + n + 1, iface->addr + n,
(iface->addrs - n - 1) * sizeof *iface->addr);
iface->addrs--;
n--;
}
close(s);
return 0;
}
close(s);
ncp_IfaceAddrAdded(ncp, iface->addr + n);
return 1;
}
}
addr = (struct iface_addr *)realloc
(iface->addr, (iface->addrs + 1) * sizeof iface->addr[0]);
if (addr == NULL) {
log_Printf(LogERROR, "iface_inAdd: realloc: %s\n", strerror(errno));
close(s);
return 0;
}
iface->addr = addr;
ncprange_copy(&newaddr.ifa, ifa);
ncpaddr_copy(&newaddr.peer, peer);
newaddr.system = !!(how & IFACE_SYSTEM);
if (!iface_addr_Add(iface->name, &newaddr, s)) {
close(s);
return 0;
}
if (how & IFACE_ADD_FIRST) {
/* Stuff it at the start of our list */
n = 0;
bcopy(iface->addr, iface->addr + 1, iface->addrs * sizeof *iface->addr);
} else
n = iface->addrs;
iface->addrs++;
memcpy(iface->addr + n, &newaddr, sizeof(*iface->addr));
close(s);
ncp_IfaceAddrAdded(ncp, iface->addr + n);
return 1;
}
int
iface_Delete(struct iface *iface, struct ncp *ncp, const struct ncpaddr *del)
{
struct ncpaddr found;
unsigned n;
int res, s;
if ((s = ID0socket(ncpaddr_family(del), SOCK_DGRAM, 0)) == -1) {
log_Printf(LogERROR, "iface_Delete: socket(): %s\n", strerror(errno));
return 0;
}
for (n = res = 0; n < iface->addrs; n++) {
ncprange_getaddr(&iface->addr[n].ifa, &found);
if (ncpaddr_equal(&found, del)) {
if (iface_addr_Zap(iface->name, iface->addr + n, s)) {
ncp_IfaceAddrDeleted(ncp, iface->addr + n);
bcopy(iface->addr + n + 1, iface->addr + n,
(iface->addrs - n - 1) * sizeof *iface->addr);
iface->addrs--;
res = 1;
}
break;
}
}
close(s);
return res;
}
#define IFACE_ADDFLAGS 1
#define IFACE_DELFLAGS 2
static int
iface_ChangeFlags(const char *ifname, int flags, int how)
{
struct ifreq ifrq;
int s, new_flags;
s = ID0socket(PF_INET, SOCK_DGRAM, 0);
if (s < 0) {
log_Printf(LogERROR, "iface_ChangeFlags: socket: %s\n", strerror(errno));
return 0;
}
memset(&ifrq, '\0', sizeof ifrq);
strncpy(ifrq.ifr_name, ifname, sizeof ifrq.ifr_name - 1);
ifrq.ifr_name[sizeof ifrq.ifr_name - 1] = '\0';
if (ID0ioctl(s, SIOCGIFFLAGS, &ifrq) < 0) {
log_Printf(LogERROR, "iface_ChangeFlags: ioctl(SIOCGIFFLAGS): %s\n",
strerror(errno));
close(s);
return 0;
}
#ifdef __FreeBSD__
new_flags = (ifrq.ifr_flags & 0xffff) | (ifrq.ifr_flagshigh << 16);
#else
new_flags = ifrq.ifr_flags & 0xffff;
#endif
if (how == IFACE_ADDFLAGS)
new_flags |= flags;
else
new_flags &= ~flags;
ifrq.ifr_flags = new_flags & 0xffff;
#ifdef __FreeBSD__
ifrq.ifr_flagshigh = new_flags >> 16;
#endif
if (ID0ioctl(s, SIOCSIFFLAGS, &ifrq) < 0) {
log_Printf(LogERROR, "iface_ChangeFlags: ioctl(SIOCSIFFLAGS): %s\n",
strerror(errno));
close(s);
return 0;
}
close(s);
return 1; /* Success */
}
int
iface_SetFlags(const char *ifname, int flags)
{
return iface_ChangeFlags(ifname, flags, IFACE_ADDFLAGS);
}
int
iface_ClearFlags(const char *ifname, int flags)
{
return iface_ChangeFlags(ifname, flags, IFACE_DELFLAGS);
}
void
iface_Destroy(struct iface *iface)
{
/*
* iface_Clear(iface, IFACE_CLEAR_ALL) must be called manually
* if that's what the user wants. It's better to leave the interface
* allocated so that existing connections can continue to work.
*/
if (iface != NULL) {
free(iface->name);
free(iface->addr);
free(iface);
}
}
#define if_entry(x) { IFF_##x, #x }
struct {
int flag;
const char *value;
} if_flags[] = {
if_entry(UP),
if_entry(BROADCAST),
if_entry(DEBUG),
if_entry(LOOPBACK),
if_entry(POINTOPOINT),
if_entry(RUNNING),
if_entry(NOARP),
if_entry(PROMISC),
if_entry(ALLMULTI),
if_entry(OACTIVE),
if_entry(SIMPLEX),
if_entry(LINK0),
if_entry(LINK1),
if_entry(LINK2),
if_entry(MULTICAST),
{ 0, "???" }
};
int
iface_Show(struct cmdargs const *arg)
{
struct ncpaddr ncpaddr;
struct iface *iface = arg->bundle->iface, *current;
unsigned f;
int flags;
#ifndef NOINET6
int scopeid, width;
#endif
struct in_addr mask;
current = iface_Create(iface->name);
flags = iface->flags = current->flags;
iface_Destroy(current);
prompt_Printf(arg->prompt, "%s (idx %d) <", iface->name, iface->index);
for (f = 0; f < sizeof if_flags / sizeof if_flags[0]; f++)
if ((if_flags[f].flag & flags)) {
prompt_Printf(arg->prompt, "%s%s", flags == iface->flags ? "" : ",",
if_flags[f].value);
flags &= ~if_flags[f].flag;
}
#if 0
if (flags)
prompt_Printf(arg->prompt, "%s0x%x", flags == iface->flags ? "" : ",",
flags);
#endif
prompt_Printf(arg->prompt, "> mtu %lu has %d address%s:\n", iface->mtu,
iface->addrs, iface->addrs == 1 ? "" : "es");
for (f = 0; f < iface->addrs; f++) {
ncprange_getaddr(&iface->addr[f].ifa, &ncpaddr);
switch (ncprange_family(&iface->addr[f].ifa)) {
case AF_INET:
prompt_Printf(arg->prompt, " inet %s --> ", ncpaddr_ntoa(&ncpaddr));
if (ncpaddr_family(&iface->addr[f].peer) == AF_UNSPEC)
prompt_Printf(arg->prompt, "255.255.255.255");
else
prompt_Printf(arg->prompt, "%s", ncpaddr_ntoa(&iface->addr[f].peer));
ncprange_getip4mask(&iface->addr[f].ifa, &mask);
prompt_Printf(arg->prompt, " netmask 0x%08lx", (long)ntohl(mask.s_addr));
break;
#ifndef NOINET6
case AF_INET6:
prompt_Printf(arg->prompt, " inet6 %s", ncpaddr_ntoa(&ncpaddr));
if (ncpaddr_family(&iface->addr[f].peer) != AF_UNSPEC)
prompt_Printf(arg->prompt, " --> %s",
ncpaddr_ntoa(&iface->addr[f].peer));
ncprange_getwidth(&iface->addr[f].ifa, &width);
if (ncpaddr_family(&iface->addr[f].peer) == AF_UNSPEC)
prompt_Printf(arg->prompt, " prefixlen %d", width);
if ((scopeid = ncprange_scopeid(&iface->addr[f].ifa)) != -1)
prompt_Printf(arg->prompt, " scopeid 0x%x", (unsigned)scopeid);
break;
#endif
}
prompt_Printf(arg->prompt, "\n");
}
return 0;
}
void
iface_ParseHdr(struct ifa_msghdr *ifam, struct sockaddr *sa[RTAX_MAX])
{
char *wp;
int rtax;
wp = (char *)(ifam + 1);
for (rtax = 0; rtax < RTAX_MAX; rtax++)
if (ifam->ifam_addrs & (1 << rtax)) {
sa[rtax] = (struct sockaddr *)wp;
wp += ROUNDUP(sa[rtax]->sa_len);
} else
sa[rtax] = NULL;
}