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-rw-r--r--c/src/lib/libnetworking/netinet/in.c728
1 files changed, 728 insertions, 0 deletions
diff --git a/c/src/lib/libnetworking/netinet/in.c b/c/src/lib/libnetworking/netinet/in.c
new file mode 100644
index 0000000000..701406f207
--- /dev/null
+++ b/c/src/lib/libnetworking/netinet/in.c
@@ -0,0 +1,728 @@
+/*
+ * 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 8.4 (Berkeley) 1/9/95
+ * $Id$
+ */
+
+#include <sys/param.h>
+#include <sys/queue.h>
+#include <sys/systm.h>
+#include <sys/ioctl.h>
+#include <sys/errno.h>
+#include <sys/malloc.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/kernel.h>
+#include <sys/sysctl.h>
+
+#include <net/if.h>
+#include <net/route.h>
+
+#include <netinet/in_systm.h>
+#include <netinet/in.h>
+#include <netinet/in_var.h>
+#include <netinet/if_ether.h>
+
+#include <netinet/igmp_var.h>
+
+/*
+ * This structure is used to keep track of in_multi chains which belong to
+ * deleted interface addresses.
+ */
+static LIST_HEAD(, multi_kludge) in_mk; /* XXX BSS initialization */
+
+struct multi_kludge {
+ LIST_ENTRY(multi_kludge) mk_entry;
+ struct ifnet *mk_ifp;
+ struct in_multihead mk_head;
+};
+
+static void in_socktrim __P((struct sockaddr_in *));
+static int in_ifinit __P((struct ifnet *,
+ struct in_ifaddr *, struct sockaddr_in *, int));
+static void in_ifscrub __P((struct ifnet *, struct in_ifaddr *));
+
+static int subnetsarelocal = 0;
+SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
+ &subnetsarelocal, 0, "");
+/*
+ * 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 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.
+ */
+int
+in_canforward(in)
+ struct in_addr in;
+{
+ register u_long i = ntohl(in.s_addr);
+ register u_long net;
+
+ if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i))
+ return (0);
+ if (IN_CLASSA(i)) {
+ net = i & IN_CLASSA_NET;
+ if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
+ return (0);
+ }
+ return (1);
+}
+
+/*
+ * Trim a mask in a sockaddr
+ */
+static 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;
+ }
+}
+
+static 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, *iap;
+ register struct ifaddr *ifa;
+ struct in_ifaddr *oia;
+ struct in_aliasreq *ifra = (struct in_aliasreq *)data;
+ struct sockaddr_in oldaddr;
+ int error, hostIsNew, maskIsNew, s;
+ u_long i;
+ struct multi_kludge *mk;
+
+ /*
+ * Find address for this interface, if it exists.
+ *
+ * If an alias address was specified, find that one instead of
+ * the first one on the interface.
+ */
+ if (ifp)
+ for (iap = in_ifaddr; iap; iap = iap->ia_next)
+ if (iap->ia_ifp == ifp) {
+ if (((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr.s_addr ==
+ iap->ia_addr.sin_addr.s_addr) {
+ ia = iap;
+ break;
+ } else if (ia == NULL) {
+ ia = iap;
+ if (ifr->ifr_addr.sa_family != AF_INET)
+ 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 ((ifp->if_flags & IFF_POINTOPOINT)
+ && (cmd == SIOCAIFADDR)
+ && (ifra->ifra_dstaddr.sin_addr.s_addr
+ == INADDR_ANY)) {
+ return EDESTADDRREQ;
+ }
+ }
+ 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) {
+ oia = (struct in_ifaddr *)
+ malloc(sizeof *oia, M_IFADDR, M_WAITOK);
+ if (oia == (struct in_ifaddr *)NULL)
+ return (ENOBUFS);
+ bzero((caddr_t)oia, sizeof *oia);
+ ia = in_ifaddr;
+ /*
+ * Protect from ipintr() traversing address list
+ * while we're modifying it.
+ */
+ s = splnet();
+
+ if (ia) {
+ for ( ; ia->ia_next; ia = ia->ia_next)
+ continue;
+ ia->ia_next = oia;
+ } else
+ in_ifaddr = oia;
+ ia = oia;
+ ifa = ifp->if_addrlist;
+ if (ifa) {
+ for ( ; ifa->ifa_next; ifa = ifa->ifa_next)
+ continue;
+ 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->if_flags & IFF_LOOPBACK))
+ in_interfaces++;
+ splx(s);
+ }
+ break;
+
+ case SIOCSIFBRDADDR:
+ if ((so->so_state & SS_PRIV) == 0)
+ return (EPERM);
+ /* FALLTHROUGH */
+
+ case SIOCGIFADDR:
+ case SIOCGIFNETMASK:
+ case SIOCGIFDSTADDR:
+ case SIOCGIFBRDADDR:
+ if (ia == (struct in_ifaddr *)0)
+ return (EADDRNOTAVAIL);
+ 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, (caddr_t)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_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 = *(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:
+ mk = malloc(sizeof *mk, M_IPMADDR, M_WAITOK);
+ if (!mk)
+ return ENOBUFS;
+
+ in_ifscrub(ifp, ia);
+ /*
+ * Protect from ipintr() traversing address list
+ * while we're modifying it.
+ */
+ s = splnet();
+
+ 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");
+ }
+
+ if (!oia->ia_multiaddrs.lh_first) {
+ IFAFREE(&oia->ia_ifa);
+ FREE(mk, M_IPMADDR);
+ splx(s);
+ break;
+ }
+
+ /*
+ * Multicast address kludge:
+ * If there were any multicast addresses attached to this
+ * interface address, either move them to another address
+ * on this interface, or save them until such time as this
+ * interface is reconfigured for IP.
+ */
+ IFP_TO_IA(oia->ia_ifp, ia);
+ if (ia) { /* there is another address */
+ struct in_multi *inm;
+ for(inm = oia->ia_multiaddrs.lh_first; inm;
+ inm = inm->inm_entry.le_next) {
+ IFAFREE(&inm->inm_ia->ia_ifa);
+ ia->ia_ifa.ifa_refcnt++;
+ inm->inm_ia = ia;
+ LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm,
+ inm_entry);
+ }
+ FREE(mk, M_IPMADDR);
+ } else { /* last address on this if deleted, save */
+ struct in_multi *inm;
+
+ LIST_INIT(&mk->mk_head);
+ mk->mk_ifp = ifp;
+
+ for(inm = oia->ia_multiaddrs.lh_first; inm;
+ inm = inm->inm_entry.le_next) {
+ LIST_INSERT_HEAD(&mk->mk_head, inm, inm_entry);
+ }
+
+ if (mk->mk_head.lh_first) {
+ LIST_INSERT_HEAD(&in_mk, mk, mk_entry);
+ } else {
+ FREE(mk, M_IPMADDR);
+ }
+ }
+
+ IFAFREE((&oia->ia_ifa));
+ splx(s);
+ break;
+
+ 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.
+ */
+static 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.
+ */
+static int
+in_ifinit(ifp, ia, sin, scrub)
+ register struct ifnet *ifp;
+ register struct in_ifaddr *ia;
+ struct sockaddr_in *sin;
+ int scrub;
+{
+ register u_long i = ntohl(sin->sin_addr.s_addr);
+ struct sockaddr_in oldaddr;
+ int s = splimp(), flags = RTF_UP, error;
+ struct multi_kludge *mk;
+
+ 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 = (struct sockaddr *)&oldaddr;
+ in_ifscrub(ifp, ia);
+ ia->ia_ifa.ifa_addr = (struct sockaddr *)&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 = htonl(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 =
+ htonl(ia->ia_subnet | ~ia->ia_subnetmask);
+ ia->ia_netbroadcast.s_addr =
+ htonl(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;
+
+ LIST_INIT(&ia->ia_multiaddrs);
+ /*
+ * If the interface supports multicast, join the "all hosts"
+ * multicast group on that interface.
+ */
+ if (ifp->if_flags & IFF_MULTICAST) {
+ struct in_addr addr;
+
+ /*
+ * Continuation of multicast address hack:
+ * If there was a multicast group list previously saved
+ * for this interface, then we re-attach it to the first
+ * address configured on the i/f.
+ */
+ for(mk = in_mk.lh_first; mk; mk = mk->mk_entry.le_next) {
+ if(mk->mk_ifp == ifp) {
+ struct in_multi *inm;
+
+ for(inm = mk->mk_head.lh_first; inm;
+ inm = inm->inm_entry.le_next) {
+ IFAFREE(&inm->inm_ia->ia_ifa);
+ ia->ia_ifa.ifa_refcnt++;
+ inm->inm_ia = ia;
+ LIST_INSERT_HEAD(&ia->ia_multiaddrs,
+ inm, inm_entry);
+ }
+ LIST_REMOVE(mk, mk_entry);
+ free(mk, M_IPMADDR);
+ break;
+ }
+ }
+
+ addr.s_addr = htonl(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;
+{
+ register struct ifaddr *ifa;
+ u_long t;
+
+ if (in.s_addr == INADDR_BROADCAST ||
+ in.s_addr == INADDR_ANY)
+ return 1;
+ if ((ifp->if_flags & IFF_BROADCAST) == 0)
+ return 0;
+ t = ntohl(in.s_addr);
+ /*
+ * Look through the list of addresses for a match
+ * with a broadcast address.
+ */
+#define ia ((struct in_ifaddr *)ifa)
+ for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
+ if (ifa->ifa_addr->sa_family == AF_INET &&
+ (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.
+ */
+ t == ia->ia_subnet || t == ia->ia_net) &&
+ /*
+ * Check for an all one subnetmask. These
+ * only exist when an interface gets a secondary
+ * address.
+ */
+ ia->ia_subnetmask != (u_long)0xffffffff)
+ 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 = splnet();
+
+ /*
+ * 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;
+ ia->ia_ifa.ifa_refcnt++; /* gain a reference */
+ LIST_INSERT_HEAD(&ia->ia_multiaddrs, inm, inm_entry);
+
+ /*
+ * Ask the network driver to update its multicast reception
+ * filter appropriately for the new address.
+ */
+ ((struct sockaddr_in *)&ifr.ifr_addr)->sin_family = AF_INET;
+ ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr = *ap;
+ if ((ifp->if_ioctl == NULL) ||
+ (*ifp->if_ioctl)(ifp, SIOCADDMULTI,(caddr_t)&ifr) != 0) {
+ LIST_REMOVE(inm, inm_entry);
+ IFAFREE(&ia->ia_ifa); /* release reference */
+ 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 = splnet();
+
+ 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_entry);
+ IFAFREE(&inm->inm_ia->ia_ifa); /* release reference */
+
+ /*
+ * Notify the network driver to update its multicast reception
+ * filter.
+ */
+ ((struct sockaddr_in *)&(ifr.ifr_addr))->sin_family = AF_INET;
+ ((struct sockaddr_in *)&(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);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-16 09:58:20 +0000