/* $OpenBSD: in.c,v 1.12 1998/04/25 23:38:21 d Exp $ */ /* $NetBSD: in.c,v 1.26 1996/02/13 23:41:39 christos Exp $ */ /* * Copyright (c) 1982, 1986, 1991, 1993 * The Regents of the University of California. 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. 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 8.2 (Berkeley) 11/15/93 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ether.h" #ifdef INET #ifndef SUBNETSARELOCAL #define SUBNETSARELOCAL 0 #endif 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. */ int in_localaddr(in) struct in_addr in; { register struct in_ifaddr *ia; if (subnetsarelocal) { for (ia = in_ifaddr.tqh_first; ia != 0; ia = ia->ia_list.tqe_next) if ((in.s_addr & ia->ia_netmask) == ia->ia_net) return (1); } else { for (ia = in_ifaddr.tqh_first; ia != 0; ia = ia->ia_list.tqe_next) if ((in.s_addr & 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. */ int in_canforward(in) struct in_addr in; { register u_int32_t net; if (IN_EXPERIMENTAL(in.s_addr) || IN_MULTICAST(in.s_addr)) return (0); if (IN_CLASSA(in.s_addr)) { net = in.s_addr & IN_CLASSA_NET; if (net == 0 || net == htonl(IN_LOOPBACKNET << IN_CLASSA_NSHIFT)) return (0); } return (1); } /* * Trim a mask in a sockaddr */ void in_socktrim(ap) struct sockaddr_in *ap; { register char *cplim = (char *) &ap->sin_addr; register char *cp = (char *) (&ap->sin_addr + 1); ap->sin_len = 0; while (--cp >= cplim) if (*cp) { (ap)->sin_len = cp - (char *) (ap) + 1; break; } } int in_interfaces; /* number of external internet interfaces */ /* * Generic internet control operations (ioctl's). * Ifp is 0 if not an interface-specific ioctl. */ /* ARGSUSED */ int in_control(so, cmd, data, ifp) struct socket *so; u_long cmd; caddr_t data; register struct ifnet *ifp; { register struct ifreq *ifr = (struct ifreq *)data; register struct in_ifaddr *ia = 0; struct in_aliasreq *ifra = (struct in_aliasreq *)data; struct sockaddr_in oldaddr; int error, hostIsNew, maskIsNew; /* * Find address for this interface, if it exists. */ if (ifp) for (ia = in_ifaddr.tqh_first; ia; ia = ia->ia_list.tqe_next) if (ia->ia_ifp == ifp) break; switch (cmd) { case SIOCAIFADDR: case SIOCDIFADDR: if (ifra->ifra_addr.sin_family == AF_INET) for (; ia != 0; ia = ia->ia_list.tqe_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 ((so->so_state & SS_PRIV) == 0) return (EPERM); if (ifp == 0) panic("in_control"); if (ia == (struct in_ifaddr *)0) { ia = (struct in_ifaddr *) malloc(sizeof *ia, M_IFADDR, M_WAITOK); if (ia == (struct in_ifaddr *)0) return (ENOBUFS); bzero((caddr_t)ia, sizeof *ia); TAILQ_INSERT_TAIL(&in_ifaddr, ia, ia_list); TAILQ_INSERT_TAIL(&ifp->if_addrlist, (struct ifaddr *)ia, ifa_list); ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr); ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr); ia->ia_ifa.ifa_netmask = sintosa(&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; LIST_INIT(&ia->ia_multiaddrs); if ((ifp->if_flags & IFF_LOOPBACK) == 0) in_interfaces++; } break; case SIOCSIFBRDADDR: if ((so->so_state & SS_PRIV) == 0) return (EPERM); /* FALLTHROUGH */ case SIOCGIFADDR: case SIOCGIFNETMASK: case SIOCGIFDSTADDR: case SIOCGIFBRDADDR: if (ia && satosin(&ifr->ifr_addr)->sin_addr.s_addr) { struct in_ifaddr *ia2; for (ia2 = ia; ia2; ia2 = ia2->ia_list.tqe_next) { if (ia2->ia_ifp == ifp && ia2->ia_addr.sin_addr.s_addr == satosin(&ifr->ifr_addr)->sin_addr.s_addr) break; } if (ia2 && ia2->ia_ifp == ifp) ia = ia2; } if (ia == (struct in_ifaddr *)0) return (EADDRNOTAVAIL); break; } switch (cmd) { case SIOCGIFADDR: *satosin(&ifr->ifr_addr) = ia->ia_addr; break; case SIOCGIFBRDADDR: if ((ifp->if_flags & IFF_BROADCAST) == 0) return (EINVAL); *satosin(&ifr->ifr_dstaddr) = ia->ia_broadaddr; break; case SIOCGIFDSTADDR: if ((ifp->if_flags & IFF_POINTOPOINT) == 0) return (EINVAL); *satosin(&ifr->ifr_dstaddr) = ia->ia_dstaddr; break; case SIOCGIFNETMASK: *satosin(&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 = *satosin(&ifr->ifr_dstaddr); if (ifp->if_ioctl && (error = (*ifp->if_ioctl) (ifp, SIOCSIFDSTADDR, (caddr_t)ia))) { ia->ia_dstaddr = oldaddr; return (error); } if (ia->ia_flags & IFA_ROUTE) { ia->ia_ifa.ifa_dstaddr = sintosa(&oldaddr); rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); ia->ia_ifa.ifa_dstaddr = sintosa(&ia->ia_dstaddr); 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 = *satosin(&ifr->ifr_broadaddr); break; case SIOCSIFADDR: return (in_ifinit(ifp, ia, satosin(&ifr->ifr_addr), 1)); case SIOCSIFNETMASK: ia->ia_subnetmask = ia->ia_sockmask.sin_addr.s_addr = ifra->ifra_addr.sin_addr.s_addr; 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 = 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); TAILQ_REMOVE(&ifp->if_addrlist, (struct ifaddr *)ia, ifa_list); TAILQ_REMOVE(&in_ifaddr, ia, ia_list); IFAFREE((&ia->ia_ifa)); break; #ifdef MROUTING case SIOCGETVIFCNT: case SIOCGETSGCNT: return (mrt_ioctl(cmd, data)); #endif /* MROUTING */ default: if (ifp == 0 || ifp->if_ioctl == 0) return (EOPNOTSUPP); return ((*ifp->if_ioctl)(ifp, cmd, data)); } return (0); } /* * Delete any existing route for an interface. */ void in_ifscrub(ifp, ia) register struct ifnet *ifp; register struct in_ifaddr *ia; { if ((ia->ia_flags & IFA_ROUTE) == 0) return; if (ifp->if_flags & (IFF_LOOPBACK|IFF_POINTOPOINT)) rtinit(&(ia->ia_ifa), (int)RTM_DELETE, RTF_HOST); else rtinit(&(ia->ia_ifa), (int)RTM_DELETE, 0); ia->ia_flags &= ~IFA_ROUTE; } /* * Initialize an interface's internet address * and routing table entry. */ int in_ifinit(ifp, ia, sin, scrub) register struct ifnet *ifp; register struct in_ifaddr *ia; struct sockaddr_in *sin; int scrub; { register u_int32_t i = sin->sin_addr.s_addr; struct sockaddr_in oldaddr; int s = splimp(), flags = RTF_UP, error; oldaddr = ia->ia_addr; ia->ia_addr = *sin; /* * Give the interface a chance to initialize * if this is its first address, * and to validate the address if necessary. */ if (ifp->if_ioctl && (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, (caddr_t)ia))) { splx(s); ia->ia_addr = oldaddr; return (error); } splx(s); if (scrub) { ia->ia_ifa.ifa_addr = sintosa(&oldaddr); in_ifscrub(ifp, ia); ia->ia_ifa.ifa_addr = sintosa(&ia->ia_addr); } if (IN_CLASSA(i)) ia->ia_netmask = IN_CLASSA_NET; else if (IN_CLASSB(i)) ia->ia_netmask = IN_CLASSB_NET; else ia->ia_netmask = IN_CLASSC_NET; /* * The subnet mask usually includes at least the standard network part, * but may may be smaller in the case of supernetting. * If it is set, we believe it. */ if (ia->ia_subnetmask == 0) { ia->ia_subnetmask = ia->ia_netmask; ia->ia_sockmask.sin_addr.s_addr = ia->ia_subnetmask; } else ia->ia_netmask &= ia->ia_subnetmask; ia->ia_net = i & ia->ia_netmask; ia->ia_subnet = i & ia->ia_subnetmask; in_socktrim(&ia->ia_sockmask); /* * Add route for the network. */ ia->ia_ifa.ifa_metric = ifp->if_metric; if (ifp->if_flags & IFF_BROADCAST) { ia->ia_broadaddr.sin_addr.s_addr = ia->ia_subnet | ~ia->ia_subnetmask; ia->ia_netbroadcast.s_addr = ia->ia_net | ~ia->ia_netmask; } else if (ifp->if_flags & IFF_LOOPBACK) { ia->ia_ifa.ifa_dstaddr = ia->ia_ifa.ifa_addr; flags |= RTF_HOST; } else if (ifp->if_flags & IFF_POINTOPOINT) { if (ia->ia_dstaddr.sin_family != AF_INET) return (0); flags |= RTF_HOST; } if ((error = rtinit(&(ia->ia_ifa), (int)RTM_ADD, flags)) == 0) ia->ia_flags |= IFA_ROUTE; /* * If the interface supports multicast, join the "all hosts" * multicast group on that interface. */ if (ifp->if_flags & IFF_MULTICAST) { struct in_addr addr; addr.s_addr = INADDR_ALLHOSTS_GROUP; in_addmulti(&addr, ifp); } return (error); } /* * Return 1 if the address might be a local broadcast address. */ int in_broadcast(in, ifp) struct in_addr in; struct ifnet *ifp; { struct ifnet *ifn, *if_first, *if_target; register struct ifaddr *ifa; if (in.s_addr == INADDR_BROADCAST || in.s_addr == INADDR_ANY) return 1; if (ifp && ((ifp->if_flags & IFF_BROADCAST) == 0)) return 0; if (ifp == NULL) { if_first = ifnet.tqh_first; if_target = 0; } else { if_first = ifp; if_target = ifp->if_list.tqe_next; } #define ia (ifatoia(ifa)) /* * Look through the list of addresses for a match * with a broadcast address. * If ifp is NULL, check against all the interfaces. */ for (ifn = if_first; ifn != if_target; ifn = ifn->if_list.tqe_next) for (ifa = ifn->if_addrlist.tqh_first; ifa; ifa = ifa->ifa_list.tqe_next) if (!ifp) { if (ifa->ifa_addr->sa_family == AF_INET && ((ia->ia_subnetmask != 0xffffffff && (((ifn->if_flags & IFF_BROADCAST) && in.s_addr == ia->ia_broadaddr.sin_addr.s_addr) || in.s_addr == ia->ia_subnet)) || /* * Check for old-style (host 0) broadcast. */ (in.s_addr == ia->ia_netbroadcast.s_addr || in.s_addr == ia->ia_net))) return 1; } else if (ifa->ifa_addr->sa_family == AF_INET && (((ifn->if_flags & IFF_BROADCAST) && in.s_addr == ia->ia_broadaddr.sin_addr.s_addr) || in.s_addr == ia->ia_netbroadcast.s_addr || /* * Check for old-style (host 0) broadcast. */ in.s_addr == ia->ia_subnet || in.s_addr == ia->ia_net)) return 1; return (0); #undef ia } /* * Add an address to the list of IP multicast addresses for a given interface. */ struct in_multi * in_addmulti(ap, ifp) register struct in_addr *ap; register struct ifnet *ifp; { register struct in_multi *inm; struct ifreq ifr; struct in_ifaddr *ia; int s = splsoftnet(); /* * See if address already in list. */ IN_LOOKUP_MULTI(*ap, ifp, inm); if (inm != NULL) { /* * Found it; just increment the reference count. */ ++inm->inm_refcount; } else { /* * New address; allocate a new multicast record * and link it into the interface's multicast list. */ inm = (struct in_multi *)malloc(sizeof(*inm), M_IPMADDR, M_NOWAIT); if (inm == NULL) { splx(s); return (NULL); } inm->inm_addr = *ap; inm->inm_ifp = ifp; inm->inm_refcount = 1; IFP_TO_IA(ifp, ia); if (ia == NULL) { free(inm, M_IPMADDR); splx(s); return (NULL); } inm->inm_ia = ia; LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, inm_list); /* * Ask the network driver to update its multicast reception * filter appropriately for the new address. */ satosin(&ifr.ifr_addr)->sin_len = sizeof(struct sockaddr_in); satosin(&ifr.ifr_addr)->sin_family = AF_INET; satosin(&ifr.ifr_addr)->sin_addr = *ap; if ((ifp->if_ioctl == NULL) || (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) { LIST_REMOVE(inm, inm_list); free(inm, M_IPMADDR); splx(s); return (NULL); } /* * Let IGMP know that we have joined a new IP multicast group. */ igmp_joingroup(inm); } splx(s); return (inm); } /* * Delete a multicast address record. */ void in_delmulti(inm) register struct in_multi *inm; { struct ifreq ifr; int s = splsoftnet(); if (--inm->inm_refcount == 0) { /* * No remaining claims to this record; let IGMP know that * we are leaving the multicast group. */ igmp_leavegroup(inm); /* * Unlink from list. */ LIST_REMOVE(inm, inm_list); /* * Notify the network driver to update its multicast reception * filter. */ satosin(&ifr.ifr_addr)->sin_family = AF_INET; satosin(&ifr.ifr_addr)->sin_addr = inm->inm_addr; (*inm->inm_ifp->if_ioctl)(inm->inm_ifp, SIOCDELMULTI, (caddr_t)&ifr); free(inm, M_IPMADDR); } splx(s); } #endif