+int subnetsarelocal = SUBNETSARELOCAL;
+/*
+ * Return 1 if an internet address is for a ``local'' host
+ * (one to which we have a connection). If subnetsarelocal
+ * is true, this includes other subnets of the local net.
+ * Otherwise, it includes only the directly-connected (sub)nets.
+ */
+in_localaddr(in)
+ struct in_addr in;
+{
+ register u_long i = ntohl(in.s_addr);
+ register struct in_ifaddr *ia;
+
+ if (subnetsarelocal) {
+ for (ia = in_ifaddr; ia; ia = ia->ia_next)
+ if ((i & ia->ia_netmask) == ia->ia_net)
+ return (1);
+ } else {
+ for (ia = in_ifaddr; ia; ia = ia->ia_next)
+ if ((i & ia->ia_subnetmask) == ia->ia_subnet)
+ return (1);
+ }
+ return (0);
+}
+
+/*
+ * 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.
+ */
+in_canforward(in)
+ struct in_addr in;
+{
+ register u_long i = ntohl(in.s_addr);
+ register u_long net;
+
+ if (IN_EXPERIMENTAL(i))
+ return (0);
+ if (IN_CLASSA(i)) {
+ net = i & IN_CLASSA_NET;
+ if (net == 0 || net == IN_LOOPBACKNET)
+ return (0);
+ }
+ return (1);
+}
+
+int in_interfaces; /* number of external internet interfaces */
+extern struct ifnet loif;
+
+/*
+ * Generic internet control operations (ioctl's).
+ * Ifp is 0 if not an interface-specific ioctl.
+ */
+/* ARGSUSED */
+in_control(so, cmd, data, ifp)
+ struct socket *so;
+ int cmd;
+ caddr_t data;
+ register struct ifnet *ifp;
+{
+ register struct ifreq *ifr = (struct ifreq *)data;
+ register struct in_ifaddr *ia = 0;
+ register struct ifaddr *ifa;
+ struct in_ifaddr *oia;
+ struct in_aliasreq *ifra = (struct in_aliasreq *)data;
+ struct mbuf *m;
+ struct sockaddr_in oldaddr;
+ int error, hostIsNew, maskIsNew;
+ u_long i;
+
+ /*
+ * Find address for this interface, if it exists.
+ */
+ if (ifp)
+ for (ia = in_ifaddr; ia; ia = ia->ia_next)
+ if (ia->ia_ifp == ifp)
+ break;
+
+ switch (cmd) {
+
+ case SIOCAIFADDR:
+ case SIOCDIFADDR:
+ if (ifra->ifra_addr.sin_family == AF_INET)
+ for (oia = ia; ia; ia = ia->ia_next) {
+ if (ia->ia_ifp == ifp &&
+ ia->ia_addr.sin_addr.s_addr ==
+ ifra->ifra_addr.sin_addr.s_addr)
+ break;
+ }
+ if (cmd == SIOCDIFADDR && ia == 0)
+ return (EADDRNOTAVAIL);
+ /* FALLTHROUGH */
+ case SIOCSIFADDR:
+ case SIOCSIFNETMASK:
+ case SIOCSIFDSTADDR:
+ if (error = suser(u.u_cred, &u.u_acflag))
+ return (error);
+
+ if (ifp == 0)
+ panic("in_control");
+ if (ia == (struct in_ifaddr *)0) {
+ m = m_getclr(M_WAIT, MT_IFADDR);
+ if (m == (struct mbuf *)NULL)
+ return (ENOBUFS);
+ if (ia = in_ifaddr) {
+ for ( ; ia->ia_next; ia = ia->ia_next)
+ ;
+ ia->ia_next = mtod(m, struct in_ifaddr *);
+ } else
+ in_ifaddr = mtod(m, struct in_ifaddr *);
+ ia = mtod(m, struct in_ifaddr *);
+ if (ifa = ifp->if_addrlist) {
+ for ( ; ifa->ifa_next; ifa = ifa->ifa_next)
+ ;
+ ifa->ifa_next = (struct ifaddr *) ia;
+ } else
+ ifp->if_addrlist = (struct ifaddr *) ia;
+ ia->ia_ifa.ifa_addr = (struct sockaddr *)&ia->ia_addr;
+ ia->ia_ifa.ifa_dstaddr
+ = (struct sockaddr *)&ia->ia_dstaddr;
+ ia->ia_ifa.ifa_netmask
+ = (struct sockaddr *)&ia->ia_sockmask;
+ ia->ia_sockmask.sin_len = 8;
+ if (ifp->if_flags & IFF_BROADCAST) {
+ ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
+ ia->ia_broadaddr.sin_family = AF_INET;
+ }
+ ia->ia_ifp = ifp;
+ if (ifp != &loif)
+ in_interfaces++;
+ }
+ break;
+
+ case SIOCSIFBRDADDR:
+ if (error = suser(u.u_cred, &u.u_acflag))
+ return (error);
+ /* FALLTHROUGH */
+
+ case SIOCGIFADDR:
+ case SIOCGIFNETMASK:
+ case SIOCGIFDSTADDR:
+ case SIOCGIFBRDADDR:
+ if (ia == (struct in_ifaddr *)0)
+ return (EADDRNOTAVAIL);
+ break;
+
+ default:
+ return (EOPNOTSUPP);
+ break;
+ }
+ switch (cmd) {
+
+ case SIOCGIFADDR:
+ *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_addr;
+ break;
+
+ case SIOCGIFBRDADDR:
+ if ((ifp->if_flags & IFF_BROADCAST) == 0)
+ return (EINVAL);
+ *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_broadaddr;
+ break;
+
+ case SIOCGIFDSTADDR:
+ if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
+ return (EINVAL);
+ *((struct sockaddr_in *)&ifr->ifr_dstaddr) = ia->ia_dstaddr;
+ break;
+
+ case SIOCGIFNETMASK:
+ *((struct sockaddr_in *)&ifr->ifr_addr) = ia->ia_sockmask;
+ break;
+
+ case SIOCSIFDSTADDR:
+ if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
+ return (EINVAL);
+ oldaddr = ia->ia_dstaddr;
+ ia->ia_dstaddr = *(struct sockaddr_in *)&ifr->ifr_dstaddr;
+ if (ifp->if_ioctl &&
+ (error = (*ifp->if_ioctl)(ifp, SIOCSIFDSTADDR, ia))) {
+ ia->ia_dstaddr = oldaddr;
+ return (error);
+ }
+ if (ia->ia_flags & IFA_ROUTE) {
+ ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&oldaddr;
+ rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST);
+ ia->ia_ifa.ifa_dstaddr = (struct sockaddr *)&ia->ia_addr;
+ rtinit(&(ia->ia_ifa), (int)RTM_ADD, RTF_HOST|RTF_UP);
+ }
+ break;
+
+ case SIOCSIFBRDADDR:
+ if ((ifp->if_flags & IFF_BROADCAST) == 0)
+ return (EINVAL);
+ ia->ia_broadaddr = *(struct sockaddr_in *)&ifr->ifr_broadaddr;
+ break;
+
+ case SIOCSIFADDR:
+ return (in_ifinit(ifp, ia,
+ (struct sockaddr_in *) &ifr->ifr_addr, 1));
+
+ case SIOCSIFNETMASK:
+ i = ifra->ifra_addr.sin_addr.s_addr;
+ ia->ia_subnetmask = ntohl(ia->ia_sockmask.sin_addr.s_addr = i);
+ break;
+
+ case SIOCAIFADDR:
+ maskIsNew = 0;
+ hostIsNew = 1;
+ error = 0;
+ if (ia->ia_addr.sin_family == AF_INET) {
+ if (ifra->ifra_addr.sin_len == 0) {
+ ifra->ifra_addr = ia->ia_addr;
+ hostIsNew = 0;
+ } else if (ifra->ifra_addr.sin_addr.s_addr ==
+ ia->ia_addr.sin_addr.s_addr)
+ hostIsNew = 0;
+ }
+ if (ifra->ifra_mask.sin_len) {
+ in_ifscrub(ifp, ia);
+ ia->ia_sockmask = ifra->ifra_mask;
+ ia->ia_subnetmask =
+ ntohl(ia->ia_sockmask.sin_addr.s_addr);
+ maskIsNew = 1;
+ }
+ if ((ifp->if_flags & IFF_POINTOPOINT) &&
+ (ifra->ifra_dstaddr.sin_family == AF_INET)) {
+ in_ifscrub(ifp, ia);
+ ia->ia_dstaddr = ifra->ifra_dstaddr;
+ maskIsNew = 1; /* We lie; but the effect's the same */
+ }
+ if (ifra->ifra_addr.sin_family == AF_INET &&
+ (hostIsNew || maskIsNew))
+ error = in_ifinit(ifp, ia, &ifra->ifra_addr, 0);
+ if ((ifp->if_flags & IFF_BROADCAST) &&
+ (ifra->ifra_broadaddr.sin_family == AF_INET))
+ ia->ia_broadaddr = ifra->ifra_broadaddr;
+ return (error);
+
+ case SIOCDIFADDR:
+ in_ifscrub(ifp, ia);
+ if ((ifa = ifp->if_addrlist) == (struct ifaddr *)ia)
+ ifp->if_addrlist = ifa->ifa_next;
+ else {
+ while (ifa->ifa_next &&
+ (ifa->ifa_next != (struct ifaddr *)ia))
+ ifa = ifa->ifa_next;
+ if (ifa->ifa_next)
+ ifa->ifa_next = ((struct ifaddr *)ia)->ifa_next;
+ else
+ printf("Couldn't unlink inifaddr from ifp\n");
+ }
+ oia = ia;
+ if (oia == (ia = in_ifaddr))
+ in_ifaddr = ia->ia_next;
+ else {
+ while (ia->ia_next && (ia->ia_next != oia))
+ ia = ia->ia_next;
+ if (ia->ia_next)
+ ia->ia_next = oia->ia_next;
+ else
+ printf("Didn't unlink inifadr from list\n");
+ }
+ (void) m_free(dtom(oia));
+ break;
+
+ default:
+ if (ifp == 0 || ifp->if_ioctl == 0)
+ return (EOPNOTSUPP);
+ return ((*ifp->if_ioctl)(ifp, cmd, data));
+ }
+ return (0);
+}