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-rw-r--r--sys/netipsec/xform_ipip.c688
1 files changed, 688 insertions, 0 deletions
diff --git a/sys/netipsec/xform_ipip.c b/sys/netipsec/xform_ipip.c
new file mode 100644
index 0000000..8191009
--- /dev/null
+++ b/sys/netipsec/xform_ipip.c
@@ -0,0 +1,688 @@
+/* $FreeBSD$ */
+/* $OpenBSD: ip_ipip.c,v 1.25 2002/06/10 18:04:55 itojun Exp $ */
+/*-
+ * The authors of this code are John Ioannidis (ji@tla.org),
+ * Angelos D. Keromytis (kermit@csd.uch.gr) and
+ * Niels Provos (provos@physnet.uni-hamburg.de).
+ *
+ * The original version of this code was written by John Ioannidis
+ * for BSD/OS in Athens, Greece, in November 1995.
+ *
+ * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
+ * by Angelos D. Keromytis.
+ *
+ * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis
+ * and Niels Provos.
+ *
+ * Additional features in 1999 by Angelos D. Keromytis.
+ *
+ * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis,
+ * Angelos D. Keromytis and Niels Provos.
+ * Copyright (c) 2001, Angelos D. Keromytis.
+ *
+ * Permission to use, copy, and modify this software with or without fee
+ * is hereby granted, provided that this entire notice is included in
+ * all copies of any software which is or includes a copy or
+ * modification of this software.
+ * You may use this code under the GNU public license if you so wish. Please
+ * contribute changes back to the authors under this freer than GPL license
+ * so that we may further the use of strong encryption without limitations to
+ * all.
+ *
+ * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
+ * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
+ * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
+ * PURPOSE.
+ */
+
+/*
+ * IP-inside-IP processing
+ */
+#include "opt_inet.h"
+#include "opt_inet6.h"
+#include "opt_enc.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/kernel.h>
+#include <sys/protosw.h>
+#include <sys/sysctl.h>
+
+#include <net/if.h>
+#include <net/route.h>
+#include <net/netisr.h>
+
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/in_var.h>
+#include <netinet/ip.h>
+#include <netinet/ip_ecn.h>
+#include <netinet/ip_var.h>
+#include <netinet/ip_encap.h>
+
+#include <netipsec/ipsec.h>
+#include <netipsec/xform.h>
+
+#include <netipsec/ipip_var.h>
+
+#ifdef MROUTING
+#include <netinet/ip_mroute.h>
+#endif
+
+#ifdef INET6
+#include <netinet/ip6.h>
+#include <netipsec/ipsec6.h>
+#include <netinet6/ip6_ecn.h>
+#include <netinet6/in6_var.h>
+#include <netinet6/ip6protosw.h>
+#endif
+
+#include <netipsec/key.h>
+#include <netipsec/key_debug.h>
+
+#include <machine/stdarg.h>
+
+/*
+ * We can control the acceptance of IP4 packets by altering the sysctl
+ * net.inet.ipip.allow value. Zero means drop them, all else is acceptance.
+ */
+int ipip_allow = 0;
+struct ipipstat ipipstat;
+
+SYSCTL_DECL(_net_inet_ipip);
+SYSCTL_INT(_net_inet_ipip, OID_AUTO,
+ ipip_allow, CTLFLAG_RW, &ipip_allow, 0, "");
+SYSCTL_STRUCT(_net_inet_ipip, IPSECCTL_STATS,
+ stats, CTLFLAG_RD, &ipipstat, ipipstat, "");
+
+/* XXX IPCOMP */
+#define M_IPSEC (M_AUTHIPHDR|M_AUTHIPDGM|M_DECRYPTED)
+
+static void _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp);
+
+#ifdef INET6
+/*
+ * Really only a wrapper for ipip_input(), for use with IPv6.
+ */
+int
+ip4_input6(struct mbuf **m, int *offp, int proto)
+{
+#if 0
+ /* If we do not accept IP-in-IP explicitly, drop. */
+ if (!ipip_allow && ((*m)->m_flags & M_IPSEC) == 0) {
+ DPRINTF(("%s: dropped due to policy\n", __func__));
+ ipipstat.ipips_pdrops++;
+ m_freem(*m);
+ return IPPROTO_DONE;
+ }
+#endif
+ _ipip_input(*m, *offp, NULL);
+ return IPPROTO_DONE;
+}
+#endif /* INET6 */
+
+#ifdef INET
+/*
+ * Really only a wrapper for ipip_input(), for use with IPv4.
+ */
+void
+ip4_input(struct mbuf *m, int off)
+{
+#if 0
+ /* If we do not accept IP-in-IP explicitly, drop. */
+ if (!ipip_allow && (m->m_flags & M_IPSEC) == 0) {
+ DPRINTF(("%s: dropped due to policy\n", __func__));
+ ipipstat.ipips_pdrops++;
+ m_freem(m);
+ return;
+ }
+#endif
+ _ipip_input(m, off, NULL);
+}
+#endif /* INET */
+
+/*
+ * ipip_input gets called when we receive an IP{46} encapsulated packet,
+ * either because we got it at a real interface, or because AH or ESP
+ * were being used in tunnel mode (in which case the rcvif element will
+ * contain the address of the encX interface associated with the tunnel.
+ */
+
+static void
+_ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp)
+{
+ register struct sockaddr_in *sin;
+ register struct ifnet *ifp;
+ register struct ifaddr *ifa;
+ struct ip *ipo;
+#ifdef INET6
+ register struct sockaddr_in6 *sin6;
+ struct ip6_hdr *ip6 = NULL;
+ u_int8_t itos;
+#endif
+ u_int8_t nxt;
+ int isr;
+ u_int8_t otos;
+ u_int8_t v;
+ int hlen;
+
+ ipipstat.ipips_ipackets++;
+
+ m_copydata(m, 0, 1, &v);
+
+ switch (v >> 4) {
+#ifdef INET
+ case 4:
+ hlen = sizeof(struct ip);
+ break;
+#endif /* INET */
+#ifdef INET6
+ case 6:
+ hlen = sizeof(struct ip6_hdr);
+ break;
+#endif
+ default:
+ ipipstat.ipips_family++;
+ m_freem(m);
+ return /* EAFNOSUPPORT */;
+ }
+
+ /* Bring the IP header in the first mbuf, if not there already */
+ if (m->m_len < hlen) {
+ if ((m = m_pullup(m, hlen)) == NULL) {
+ DPRINTF(("%s: m_pullup (1) failed\n", __func__));
+ ipipstat.ipips_hdrops++;
+ return;
+ }
+ }
+
+ ipo = mtod(m, struct ip *);
+
+#ifdef MROUTING
+ if (ipo->ip_v == IPVERSION && ipo->ip_p == IPPROTO_IPV4) {
+ if (IN_MULTICAST(((struct ip *)((char *) ipo + iphlen))->ip_dst.s_addr)) {
+ ipip_mroute_input (m, iphlen);
+ return;
+ }
+ }
+#endif /* MROUTING */
+
+ /* Keep outer ecn field. */
+ switch (v >> 4) {
+#ifdef INET
+ case 4:
+ otos = ipo->ip_tos;
+ break;
+#endif /* INET */
+#ifdef INET6
+ case 6:
+ otos = (ntohl(mtod(m, struct ip6_hdr *)->ip6_flow) >> 20) & 0xff;
+ break;
+#endif
+ default:
+ panic("ipip_input: unknown ip version %u (outer)", v>>4);
+ }
+
+ /* Remove outer IP header */
+ m_adj(m, iphlen);
+
+ /* Sanity check */
+ if (m->m_pkthdr.len < sizeof(struct ip)) {
+ ipipstat.ipips_hdrops++;
+ m_freem(m);
+ return;
+ }
+
+ m_copydata(m, 0, 1, &v);
+
+ switch (v >> 4) {
+#ifdef INET
+ case 4:
+ hlen = sizeof(struct ip);
+ break;
+#endif /* INET */
+
+#ifdef INET6
+ case 6:
+ hlen = sizeof(struct ip6_hdr);
+ break;
+#endif
+ default:
+ ipipstat.ipips_family++;
+ m_freem(m);
+ return; /* EAFNOSUPPORT */
+ }
+
+ /*
+ * Bring the inner IP header in the first mbuf, if not there already.
+ */
+ if (m->m_len < hlen) {
+ if ((m = m_pullup(m, hlen)) == NULL) {
+ DPRINTF(("%s: m_pullup (2) failed\n", __func__));
+ ipipstat.ipips_hdrops++;
+ return;
+ }
+ }
+
+ /*
+ * RFC 1853 specifies that the inner TTL should not be touched on
+ * decapsulation. There's no reason this comment should be here, but
+ * this is as good as any a position.
+ */
+
+ /* Some sanity checks in the inner IP header */
+ switch (v >> 4) {
+#ifdef INET
+ case 4:
+ ipo = mtod(m, struct ip *);
+ nxt = ipo->ip_p;
+ ip_ecn_egress(ip4_ipsec_ecn, &otos, &ipo->ip_tos);
+ break;
+#endif /* INET */
+#ifdef INET6
+ case 6:
+ ip6 = (struct ip6_hdr *) ipo;
+ nxt = ip6->ip6_nxt;
+ itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
+ ip_ecn_egress(ip6_ipsec_ecn, &otos, &itos);
+ ip6->ip6_flow &= ~htonl(0xff << 20);
+ ip6->ip6_flow |= htonl((u_int32_t) itos << 20);
+ break;
+#endif
+ default:
+ panic("ipip_input: unknown ip version %u (inner)", v>>4);
+ }
+
+ /* Check for local address spoofing. */
+ if ((m->m_pkthdr.rcvif == NULL ||
+ !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) &&
+ ipip_allow != 2) {
+ IFNET_RLOCK();
+ TAILQ_FOREACH(ifp, &ifnet, if_link) {
+ TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
+#ifdef INET
+ if (ipo) {
+ if (ifa->ifa_addr->sa_family !=
+ AF_INET)
+ continue;
+
+ sin = (struct sockaddr_in *) ifa->ifa_addr;
+
+ if (sin->sin_addr.s_addr ==
+ ipo->ip_src.s_addr) {
+ ipipstat.ipips_spoof++;
+ m_freem(m);
+ IFNET_RUNLOCK();
+ return;
+ }
+ }
+#endif /* INET */
+
+#ifdef INET6
+ if (ip6) {
+ if (ifa->ifa_addr->sa_family !=
+ AF_INET6)
+ continue;
+
+ sin6 = (struct sockaddr_in6 *) ifa->ifa_addr;
+
+ if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_src)) {
+ ipipstat.ipips_spoof++;
+ m_freem(m);
+ IFNET_RUNLOCK();
+ return;
+ }
+
+ }
+#endif /* INET6 */
+ }
+ }
+ IFNET_RUNLOCK();
+ }
+
+ /* Statistics */
+ ipipstat.ipips_ibytes += m->m_pkthdr.len - iphlen;
+
+#ifdef DEV_ENC
+ /* pass the mbuf to enc0 for packet filtering */
+ if (ipsec_filter(&m, 1) != 0)
+ return;
+#endif
+
+ /*
+ * Interface pointer stays the same; if no IPsec processing has
+ * been done (or will be done), this will point to a normal
+ * interface. Otherwise, it'll point to an enc interface, which
+ * will allow a packet filter to distinguish between secure and
+ * untrusted packets.
+ */
+
+ switch (v >> 4) {
+#ifdef INET
+ case 4:
+ isr = NETISR_IP;
+ break;
+#endif
+#ifdef INET6
+ case 6:
+ isr = NETISR_IPV6;
+ break;
+#endif
+ default:
+ panic("%s: bogus ip version %u", __func__, v>>4);
+ }
+
+ if (netisr_queue(isr, m)) { /* (0) on success. */
+ ipipstat.ipips_qfull++;
+ DPRINTF(("%s: packet dropped because of full queue\n",
+ __func__));
+ }
+}
+
+int
+ipip_output(
+ struct mbuf *m,
+ struct ipsecrequest *isr,
+ struct mbuf **mp,
+ int skip,
+ int protoff
+)
+{
+ struct secasvar *sav;
+ u_int8_t tp, otos;
+ struct secasindex *saidx;
+ int error;
+#ifdef INET
+ u_int8_t itos;
+ struct ip *ipo;
+#endif /* INET */
+#ifdef INET6
+ struct ip6_hdr *ip6, *ip6o;
+#endif /* INET6 */
+
+ IPSEC_SPLASSERT_SOFTNET(__func__);
+
+ sav = isr->sav;
+ IPSEC_ASSERT(sav != NULL, ("null SA"));
+ IPSEC_ASSERT(sav->sah != NULL, ("null SAH"));
+
+ /* XXX Deal with empty TDB source/destination addresses. */
+
+ m_copydata(m, 0, 1, &tp);
+ tp = (tp >> 4) & 0xff; /* Get the IP version number. */
+
+ saidx = &sav->sah->saidx;
+ switch (saidx->dst.sa.sa_family) {
+#ifdef INET
+ case AF_INET:
+ if (saidx->src.sa.sa_family != AF_INET ||
+ saidx->src.sin.sin_addr.s_addr == INADDR_ANY ||
+ saidx->dst.sin.sin_addr.s_addr == INADDR_ANY) {
+ DPRINTF(("%s: unspecified tunnel endpoint "
+ "address in SA %s/%08lx\n", __func__,
+ ipsec_address(&saidx->dst),
+ (u_long) ntohl(sav->spi)));
+ ipipstat.ipips_unspec++;
+ error = EINVAL;
+ goto bad;
+ }
+
+ M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
+ if (m == 0) {
+ DPRINTF(("%s: M_PREPEND failed\n", __func__));
+ ipipstat.ipips_hdrops++;
+ error = ENOBUFS;
+ goto bad;
+ }
+
+ ipo = mtod(m, struct ip *);
+
+ ipo->ip_v = IPVERSION;
+ ipo->ip_hl = 5;
+ ipo->ip_len = htons(m->m_pkthdr.len);
+ ipo->ip_ttl = ip_defttl;
+ ipo->ip_sum = 0;
+ ipo->ip_src = saidx->src.sin.sin_addr;
+ ipo->ip_dst = saidx->dst.sin.sin_addr;
+
+ ipo->ip_id = ip_newid();
+
+ /* If the inner protocol is IP... */
+ if (tp == IPVERSION) {
+ /* Save ECN notification */
+ m_copydata(m, sizeof(struct ip) +
+ offsetof(struct ip, ip_tos),
+ sizeof(u_int8_t), (caddr_t) &itos);
+
+ ipo->ip_p = IPPROTO_IPIP;
+
+ /*
+ * We should be keeping tunnel soft-state and
+ * send back ICMPs if needed.
+ */
+ m_copydata(m, sizeof(struct ip) +
+ offsetof(struct ip, ip_off),
+ sizeof(u_int16_t), (caddr_t) &ipo->ip_off);
+ ipo->ip_off = ntohs(ipo->ip_off);
+ ipo->ip_off &= ~(IP_DF | IP_MF | IP_OFFMASK);
+ ipo->ip_off = htons(ipo->ip_off);
+ }
+#ifdef INET6
+ else if (tp == (IPV6_VERSION >> 4)) {
+ u_int32_t itos32;
+
+ /* Save ECN notification. */
+ m_copydata(m, sizeof(struct ip) +
+ offsetof(struct ip6_hdr, ip6_flow),
+ sizeof(u_int32_t), (caddr_t) &itos32);
+ itos = ntohl(itos32) >> 20;
+ ipo->ip_p = IPPROTO_IPV6;
+ ipo->ip_off = 0;
+ }
+#endif /* INET6 */
+ else {
+ goto nofamily;
+ }
+
+ otos = 0;
+ ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
+ ipo->ip_tos = otos;
+ break;
+#endif /* INET */
+
+#ifdef INET6
+ case AF_INET6:
+ if (IN6_IS_ADDR_UNSPECIFIED(&saidx->dst.sin6.sin6_addr) ||
+ saidx->src.sa.sa_family != AF_INET6 ||
+ IN6_IS_ADDR_UNSPECIFIED(&saidx->src.sin6.sin6_addr)) {
+ DPRINTF(("%s: unspecified tunnel endpoint "
+ "address in SA %s/%08lx\n", __func__,
+ ipsec_address(&saidx->dst),
+ (u_long) ntohl(sav->spi)));
+ ipipstat.ipips_unspec++;
+ error = ENOBUFS;
+ goto bad;
+ }
+
+ /* scoped address handling */
+ ip6 = mtod(m, struct ip6_hdr *);
+ if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
+ ip6->ip6_src.s6_addr16[1] = 0;
+ if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
+ ip6->ip6_dst.s6_addr16[1] = 0;
+
+ M_PREPEND(m, sizeof(struct ip6_hdr), M_DONTWAIT);
+ if (m == 0) {
+ DPRINTF(("%s: M_PREPEND failed\n", __func__));
+ ipipstat.ipips_hdrops++;
+ error = ENOBUFS;
+ goto bad;
+ }
+
+ /* Initialize IPv6 header */
+ ip6o = mtod(m, struct ip6_hdr *);
+ ip6o->ip6_flow = 0;
+ ip6o->ip6_vfc &= ~IPV6_VERSION_MASK;
+ ip6o->ip6_vfc |= IPV6_VERSION;
+ ip6o->ip6_plen = htons(m->m_pkthdr.len);
+ ip6o->ip6_hlim = ip_defttl;
+ ip6o->ip6_dst = saidx->dst.sin6.sin6_addr;
+ ip6o->ip6_src = saidx->src.sin6.sin6_addr;
+
+#ifdef INET
+ if (tp == IPVERSION) {
+ /* Save ECN notification */
+ m_copydata(m, sizeof(struct ip6_hdr) +
+ offsetof(struct ip, ip_tos), sizeof(u_int8_t),
+ (caddr_t) &itos);
+
+ /* This is really IPVERSION. */
+ ip6o->ip6_nxt = IPPROTO_IPIP;
+ } else
+#endif /* INET */
+ if (tp == (IPV6_VERSION >> 4)) {
+ u_int32_t itos32;
+
+ /* Save ECN notification. */
+ m_copydata(m, sizeof(struct ip6_hdr) +
+ offsetof(struct ip6_hdr, ip6_flow),
+ sizeof(u_int32_t), (caddr_t) &itos32);
+ itos = ntohl(itos32) >> 20;
+
+ ip6o->ip6_nxt = IPPROTO_IPV6;
+ } else {
+ goto nofamily;
+ }
+
+ otos = 0;
+ ip_ecn_ingress(ECN_ALLOWED, &otos, &itos);
+ ip6o->ip6_flow |= htonl((u_int32_t) otos << 20);
+ break;
+#endif /* INET6 */
+
+ default:
+nofamily:
+ DPRINTF(("%s: unsupported protocol family %u\n", __func__,
+ saidx->dst.sa.sa_family));
+ ipipstat.ipips_family++;
+ error = EAFNOSUPPORT; /* XXX diffs from openbsd */
+ goto bad;
+ }
+
+ ipipstat.ipips_opackets++;
+ *mp = m;
+
+#ifdef INET
+ if (saidx->dst.sa.sa_family == AF_INET) {
+#if 0
+ if (sav->tdb_xform->xf_type == XF_IP4)
+ tdb->tdb_cur_bytes +=
+ m->m_pkthdr.len - sizeof(struct ip);
+#endif
+ ipipstat.ipips_obytes += m->m_pkthdr.len - sizeof(struct ip);
+ }
+#endif /* INET */
+
+#ifdef INET6
+ if (saidx->dst.sa.sa_family == AF_INET6) {
+#if 0
+ if (sav->tdb_xform->xf_type == XF_IP4)
+ tdb->tdb_cur_bytes +=
+ m->m_pkthdr.len - sizeof(struct ip6_hdr);
+#endif
+ ipipstat.ipips_obytes +=
+ m->m_pkthdr.len - sizeof(struct ip6_hdr);
+ }
+#endif /* INET6 */
+
+ return 0;
+bad:
+ if (m)
+ m_freem(m);
+ *mp = NULL;
+ return (error);
+}
+
+#ifdef FAST_IPSEC
+static int
+ipe4_init(struct secasvar *sav, struct xformsw *xsp)
+{
+ sav->tdb_xform = xsp;
+ return 0;
+}
+
+static int
+ipe4_zeroize(struct secasvar *sav)
+{
+ sav->tdb_xform = NULL;
+ return 0;
+}
+
+static int
+ipe4_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
+{
+ /* This is a rather serious mistake, so no conditional printing. */
+ printf("%s: should never be called\n", __func__);
+ if (m)
+ m_freem(m);
+ return EOPNOTSUPP;
+}
+
+static struct xformsw ipe4_xformsw = {
+ XF_IP4, 0, "IPv4 Simple Encapsulation",
+ ipe4_init, ipe4_zeroize, ipe4_input, ipip_output,
+};
+
+extern struct domain inetdomain;
+static struct protosw ipe4_protosw =
+{ SOCK_RAW, &inetdomain, IPPROTO_IPV4, PR_ATOMIC|PR_ADDR|PR_LASTHDR,
+ ip4_input,
+ 0, 0, rip_ctloutput,
+ 0,
+ 0, 0, 0, 0,
+ &rip_usrreqs
+};
+#ifdef INET6
+static struct ip6protosw ipe6_protosw =
+{ SOCK_RAW, &inetdomain, IPPROTO_IPV6, PR_ATOMIC|PR_ADDR|PR_LASTHDR,
+ ip4_input6,
+ 0, 0, rip_ctloutput,
+ 0,
+ 0, 0, 0, 0,
+ &rip_usrreqs
+};
+#endif
+
+/*
+ * Check the encapsulated packet to see if we want it
+ */
+static int
+ipe4_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
+{
+ /*
+ * Only take packets coming from IPSEC tunnels; the rest
+ * must be handled by the gif tunnel code. Note that we
+ * also return a minimum priority when we want the packet
+ * so any explicit gif tunnels take precedence.
+ */
+ return ((m->m_flags & M_IPSEC) != 0 ? 1 : 0);
+}
+
+static void
+ipe4_attach(void)
+{
+ xform_register(&ipe4_xformsw);
+ /* attach to encapsulation framework */
+ /* XXX save return cookie for detach on module remove */
+ (void) encap_attach_func(AF_INET, -1,
+ ipe4_encapcheck, &ipe4_protosw, NULL);
+#ifdef INET6
+ (void) encap_attach_func(AF_INET6, -1,
+ ipe4_encapcheck, (struct protosw *)&ipe6_protosw, NULL);
+#endif
+}
+SYSINIT(ipe4_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ipe4_attach, NULL);
+#endif /* FAST_IPSEC */
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