210 lines
6.0 KiB
C
210 lines
6.0 KiB
C
/*
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* The mrouted program is covered by the license in the accompanying file
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* named "LICENSE". Use of the mrouted program represents acceptance of
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* the terms and conditions listed in that file.
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*
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* The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
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* Leland Stanford Junior University.
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*
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*
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* $Id: config.c,v 1.12 1998/05/19 20:41:29 wli Exp $
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*/
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#include "defs.h"
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struct ifconf ifc;
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/*
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* Query the kernel to find network interfaces that are multicast-capable
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* and install them in the uvifs array.
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*/
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void
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config_vifs_from_kernel()
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{
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struct ifreq *ifrp, *ifend;
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register struct uvif *v;
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register vifi_t vifi;
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int n;
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u_int32 addr, dstaddr, mask, subnet;
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short flags;
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int num_ifreq = 32; /* but note that more than 32 can't be active */
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ifc.ifc_len = num_ifreq * sizeof(struct ifreq);
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ifc.ifc_buf = malloc(ifc.ifc_len);
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while (ifc.ifc_buf) {
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if (ioctl(udp_socket, SIOCGIFCONF, (char *)&ifc) < 0)
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log(LOG_ERR, errno, "ioctl SIOCGIFCONF");
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/*
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* If the buffer was large enough to hold all the addresses
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* then break out, otherwise increase the buffer size and
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* try again.
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*
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* The only way to know that we definitely had enough space
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* is to know that there was enough space for at least one
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* more struct ifreq. ???
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*/
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if ((num_ifreq * sizeof(struct ifreq)) >
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ifc.ifc_len + sizeof(struct ifreq))
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break;
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num_ifreq *= 2;
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ifc.ifc_len = num_ifreq * sizeof(struct ifreq);
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ifc.ifc_buf = realloc(ifc.ifc_buf, ifc.ifc_len);
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}
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if (ifc.ifc_buf == NULL)
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log(LOG_ERR, ENOMEM, "config_vifs_from_kernel: ran out of memory");
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ifrp = (struct ifreq *)ifc.ifc_buf;
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ifend = (struct ifreq *)(ifc.ifc_buf + ifc.ifc_len);
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/*
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* Loop through all of the interfaces.
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*/
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for (; ifrp < ifend; ifrp = (struct ifreq *)((char *)ifrp + n)) {
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struct ifreq ifr;
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#if BSD >= 199006
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n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
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if (n < sizeof(*ifrp))
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n = sizeof(*ifrp);
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#else
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n = sizeof(*ifrp);
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#endif
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/*
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* Ignore any interface for an address family other than IP.
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*/
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log(LOG_DEBUG, 0, "found %s",ifrp->ifr_name);
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if (ifrp->ifr_addr.sa_family != AF_INET) {
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log(LOG_DEBUG,0, "skipping %s; not AF_INET",ifrp->ifr_name);
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continue;
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}
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addr = ((struct sockaddr_in *)&ifrp->ifr_addr)->sin_addr.s_addr;
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/*
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* Need a template to preserve address info that is
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* used below to locate the next entry. (Otherwise,
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* SIOCGIFFLAGS stomps over it because the requests
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* are returned in a union.)
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*/
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bcopy(ifrp->ifr_name, ifr.ifr_name, sizeof(ifr.ifr_name));
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/*
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* Ignore loopback interfaces and interfaces that do not support
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* multicast.
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*/
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if (ioctl(udp_socket, SIOCGIFFLAGS, (char *)&ifr) < 0)
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log(LOG_ERR, errno, "ioctl SIOCGIFFLAGS for %s", ifr.ifr_name);
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flags = ifr.ifr_flags;
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if ((flags & (IFF_LOOPBACK|IFF_MULTICAST)) != IFF_MULTICAST) {
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log(LOG_DEBUG,0,"skipping %s, flags=%x",ifr.ifr_name, ifr.ifr_flags);
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continue;
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}
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if (flags & IFF_POINTOPOINT) {
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if (ioctl(udp_socket, SIOCGIFDSTADDR, (char *)&ifr) < 0 )
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log(LOG_ERR, errno, "ioctl SIOCGIFDSTADDR for %s", ifr.ifr_name);
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dstaddr = ((struct sockaddr_in *)&ifr.ifr_dstaddr)->sin_addr.s_addr;
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}
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/*
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* Ignore any interface whose address and mask do not define a
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* valid subnet number, or whose address is of the form {subnet,0}
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* or {subnet,-1}.
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*/
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if (flags & IFF_POINTOPOINT) {
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/*
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* for IFF_POINTOPOINT interface, mask out the
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* host bits only. any other masks are meanless.
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* mask = 0xffffff00.
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*/
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mask = IN_CLASSC_NET;
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} else {
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if (ioctl(udp_socket, SIOCGIFNETMASK, (char *)&ifr) < 0)
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log(LOG_ERR, errno, "ioctl SIOCGIFNETMASK for %s", ifr.ifr_name);
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mask = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr;
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}
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subnet = addr & mask;
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if (!inet_valid_subnet(subnet, mask) ||
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addr == subnet ||
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addr == (subnet | ~mask)) {
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log(LOG_WARNING, 0,
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"ignoring %s, has invalid address (%s) and/or mask (%s)",
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ifr.ifr_name, inet_fmt(addr, s1), inet_fmt(mask, s2));
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continue;
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}
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/*
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* Ignore any interface that is connected to the same subnet as
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* one already installed in the uvifs array.
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*/
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for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
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if (strcmp(v->uv_name, ifr.ifr_name) == 0) {
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log(LOG_DEBUG, 0, "skipping %s (%s on subnet %s) (alias for vif#%u?)",
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v->uv_name, inet_fmt(addr, s1),
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inet_fmts(subnet, mask, s2), vifi);
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break;
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}
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if ((addr & v->uv_subnetmask) == v->uv_subnet ||
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(v->uv_subnet & mask) == subnet) {
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log(LOG_WARNING, 0, "ignoring %s, same subnet as %s",
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ifr.ifr_name, v->uv_name);
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break;
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}
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}
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if (vifi != numvifs) continue;
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/*
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* If there is room in the uvifs array, install this interface.
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*/
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if (numvifs == MAXVIFS) {
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log(LOG_WARNING, 0, "too many vifs, ignoring %s", ifr.ifr_name);
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continue;
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}
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v = &uvifs[numvifs];
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v->uv_flags = 0;
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v->uv_metric = DEFAULT_METRIC;
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v->uv_admetric = 0;
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v->uv_rate_limit = DEFAULT_PHY_RATE_LIMIT;
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v->uv_threshold = DEFAULT_THRESHOLD;
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if (flags & IFF_POINTOPOINT)
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v->uv_lcl_addr = dstaddr;
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else
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v->uv_lcl_addr = addr;
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v->uv_rmt_addr = 0;
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v->uv_dst_addr = dvmrp_group;
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v->uv_subnet = subnet;
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v->uv_subnetmask = mask;
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v->uv_subnetbcast = subnet | ~mask;
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strncpy(v->uv_name, ifr.ifr_name, IFNAMSIZ);
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v->uv_prune_lifetime = 0;
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v->uv_groups = NULL;
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v->uv_neighbors = NULL;
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v->uv_acl = NULL;
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v->uv_addrs = NULL;
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v->uv_filter = NULL;
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NBRM_CLRALL(v->uv_nbrmap);
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if (flags & IFF_POINTOPOINT)
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v->uv_flags |= VIFF_REXMIT_PRUNES;
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log(LOG_INFO,0,"installing %s (%s on subnet %s) as vif #%u - rate=%d",
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v->uv_name, inet_fmt(addr, s1), inet_fmts(subnet, mask, s2),
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numvifs, v->uv_rate_limit);
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++numvifs;
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/*
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* If the interface is not yet up, set the vifs_down flag to
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* remind us to check again later.
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*/
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if (!(flags & IFF_UP)) {
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v->uv_flags |= VIFF_DOWN;
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vifs_down = TRUE;
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}
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}
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}
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