/* $NetBSD: ip_gre.c,v 1.29 2003/09/05 23:02:43 itojun Exp $ */ /*- * Copyright (c) 1998 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Heiko W.Rupp * * IPv6-over-GRE contributed by Gert Doering * * 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. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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. */ /* * deencapsulate tunneled packets and send them on * output half is in net/if_gre.[ch] * This currently handles IPPROTO_GRE, IPPROTO_MOBILE */ #include __FBSDID("$FreeBSD$"); #include "opt_inet.h" #include "opt_inet6.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #include #include #include #include #include #include #include #else #error "ip_gre requires INET" #endif /* Needs IP headers. */ #include #include #if 1 void gre_inet_ntoa(struct in_addr in); /* XXX */ #endif static struct gre_softc *gre_lookup(struct mbuf *, u_int8_t); static struct mbuf *gre_input2(struct mbuf *, int, u_char); /* * De-encapsulate a packet and feed it back through ip input (this * routine is called whenever IP gets a packet with proto type * IPPROTO_GRE and a local destination address). * This really is simple */ int gre_input(struct mbuf **mp, int *offp, int proto) { struct mbuf *m; int off; m = *mp; off = *offp; *mp = NULL; m = gre_input2(m, off, proto); /* * If no matching tunnel that is up is found. We inject * the mbuf to raw ip socket to see if anyone picks it up. */ if (m != NULL) { *mp = m; rip_input(mp, offp, proto); } return (IPPROTO_DONE); } /* * Decapsulate. Does the real work and is called from gre_input() * (above). Returns an mbuf back if packet is not yet processed, * and NULL if it needs no further processing. proto is the protocol * number of the "calling" foo_input() routine. */ static struct mbuf * gre_input2(struct mbuf *m ,int hlen, u_char proto) { struct greip *gip; int isr; struct gre_softc *sc; u_int16_t flags; u_int32_t af; if ((sc = gre_lookup(m, proto)) == NULL) { /* No matching tunnel or tunnel is down. */ return (m); } if (m->m_len < sizeof(*gip)) { m = m_pullup(m, sizeof(*gip)); if (m == NULL) return (NULL); } gip = mtod(m, struct greip *); if_inc_counter(GRE2IFP(sc), IFCOUNTER_IPACKETS, 1); if_inc_counter(GRE2IFP(sc), IFCOUNTER_IBYTES, m->m_pkthdr.len); switch (proto) { case IPPROTO_GRE: hlen += sizeof(struct gre_h); /* process GRE flags as packet can be of variable len */ flags = ntohs(gip->gi_flags); /* Checksum & Offset are present */ if ((flags & GRE_CP) | (flags & GRE_RP)) hlen += 4; /* We don't support routing fields (variable length) */ if (flags & GRE_RP) return (m); if (flags & GRE_KP) hlen += 4; if (flags & GRE_SP) hlen += 4; switch (ntohs(gip->gi_ptype)) { /* ethertypes */ case WCCP_PROTOCOL_TYPE: if (sc->wccp_ver == WCCP_V2) hlen += 4; /* FALLTHROUGH */ case ETHERTYPE_IP: /* shouldn't need a schednetisr(), */ isr = NETISR_IP;/* as we are in ip_input */ af = AF_INET; break; #ifdef INET6 case ETHERTYPE_IPV6: isr = NETISR_IPV6; af = AF_INET6; break; #endif default: /* Others not yet supported. */ return (m); } break; default: /* Others not yet supported. */ return (m); } if (hlen > m->m_pkthdr.len) { m_freem(m); return (NULL); } /* Unlike NetBSD, in FreeBSD m_adj() adjusts m->m_pkthdr.len as well */ m_adj(m, hlen); if (bpf_peers_present(GRE2IFP(sc)->if_bpf)) { bpf_mtap2(GRE2IFP(sc)->if_bpf, &af, sizeof(af), m); } if ((GRE2IFP(sc)->if_flags & IFF_MONITOR) != 0) { m_freem(m); return(NULL); } m->m_pkthdr.rcvif = GRE2IFP(sc); netisr_queue(isr, m); /* Packet is done, no further processing needed. */ return (NULL); } /* * input routine for IPPRPOTO_MOBILE * This is a little bit diffrent from the other modes, as the * encapsulating header was not prepended, but instead inserted * between IP header and payload */ int gre_mobile_input(struct mbuf **mp, int *offp, int proto) { struct ip *ip; struct mobip_h *mip; struct mbuf *m; struct gre_softc *sc; int msiz; m = *mp; if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) { /* No matching tunnel or tunnel is down. */ m_freem(m); return (IPPROTO_DONE); } if (m->m_len < sizeof(*mip)) { m = m_pullup(m, sizeof(*mip)); if (m == NULL) return (IPPROTO_DONE); } ip = mtod(m, struct ip *); mip = mtod(m, struct mobip_h *); if_inc_counter(GRE2IFP(sc), IFCOUNTER_IPACKETS, 1); if_inc_counter(GRE2IFP(sc), IFCOUNTER_IBYTES, m->m_pkthdr.len); if (ntohs(mip->mh.proto) & MOB_H_SBIT) { msiz = MOB_H_SIZ_L; mip->mi.ip_src.s_addr = mip->mh.osrc; } else msiz = MOB_H_SIZ_S; if (m->m_len < (ip->ip_hl << 2) + msiz) { m = m_pullup(m, (ip->ip_hl << 2) + msiz); if (m == NULL) return (IPPROTO_DONE); ip = mtod(m, struct ip *); mip = mtod(m, struct mobip_h *); } mip->mi.ip_dst.s_addr = mip->mh.odst; mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8); if (gre_in_cksum((u_int16_t *)&mip->mh, msiz) != 0) { m_freem(m); return (IPPROTO_DONE); } bcopy((caddr_t)(ip) + (ip->ip_hl << 2) + msiz, (caddr_t)(ip) + (ip->ip_hl << 2), m->m_len - msiz - (ip->ip_hl << 2)); m->m_len -= msiz; m->m_pkthdr.len -= msiz; /* * On FreeBSD, rip_input() supplies us with ip->ip_len * decreased by the lengh of IP header, however, ip_input() * expects it to be full size of IP packet, so adjust accordingly. */ ip->ip_len = htons(ntohs(ip->ip_len) + sizeof(struct ip) - msiz); ip->ip_sum = 0; ip->ip_sum = in_cksum(m, (ip->ip_hl << 2)); if (bpf_peers_present(GRE2IFP(sc)->if_bpf)) { u_int32_t af = AF_INET; bpf_mtap2(GRE2IFP(sc)->if_bpf, &af, sizeof(af), m); } if ((GRE2IFP(sc)->if_flags & IFF_MONITOR) != 0) { m_freem(m); return (IPPROTO_DONE); } m->m_pkthdr.rcvif = GRE2IFP(sc); netisr_queue(NETISR_IP, m); return (IPPROTO_DONE); } /* * Find the gre interface associated with our src/dst/proto set. * * XXXRW: Need some sort of drain/refcount mechanism so that the softc * reference remains valid after it's returned from gre_lookup(). Right * now, I'm thinking it should be reference-counted with a gre_dropref() * when the caller is done with the softc. This is complicated by how * to handle destroying the gre softc; probably using a gre_drain() in * in_gre.c during destroy. */ static struct gre_softc * gre_lookup(struct mbuf *m, u_int8_t proto) { struct ip *ip = mtod(m, struct ip *); struct gre_softc *sc; GRE_LIST_LOCK(); for (sc = LIST_FIRST(&V_gre_softc_list); sc != NULL; sc = LIST_NEXT(sc, sc_list)) { if ((sc->g_dst.s_addr == ip->ip_src.s_addr) && (sc->g_src.s_addr == ip->ip_dst.s_addr) && (sc->g_proto == proto) && ((GRE2IFP(sc)->if_flags & IFF_UP) != 0)) { GRE_LIST_UNLOCK(); return (sc); } } GRE_LIST_UNLOCK(); return (NULL); }