/* $NetBSD: ip_gre.c,v 1.29 2003/09/05 23:02:43 itojun Exp $ */ /* $FreeBSD$ */ /* * 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 * * 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 NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation 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 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 "opt_inet.h" #include "opt_atalk.h" #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 input without IP? #endif #ifdef NETATALK #include #include #include #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 int 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 */ void #if __STDC__ gre_input(struct mbuf *m, ...) #else gre_input(m, va_alist) struct mbuf *m; va_dcl #endif { int off, ret, proto; va_list ap; va_start(ap, m); off = va_arg(ap, int); va_end(ap); proto = (mtod(m, struct ip *))->ip_p; ret = gre_input2(m, off, proto); /* * ret == 0 : packet not processed, meaning that * no matching tunnel that is up is found. * we inject it to raw ip socket to see if anyone picks it up. */ if (ret == 0) rip_input(m, off); } /* * decapsulate. * Does the real work and is called from gre_input() (above) * returns 0 if packet is not yet processed * and 1 if it needs no further processing * proto is the protocol number of the "calling" foo_input() * routine. */ static int gre_input2(struct mbuf *m ,int hlen, u_char proto) { struct greip *gip; int isr; struct gre_softc *sc; u_int16_t flags; if ((sc = gre_lookup(m, proto)) == NULL) { /* No matching tunnel or tunnel is down. */ return (0); } if (m->m_len < sizeof(*gip)) { m = m_pullup(m, sizeof(*gip)); if (m == NULL) return (ENOBUFS); } gip = mtod(m, struct greip *); sc->sc_if.if_ipackets++; sc->sc_if.if_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 (0); if (flags & GRE_KP) hlen += 4; if (flags & GRE_SP) hlen += 4; switch (ntohs(gip->gi_ptype)) { /* ethertypes */ case ETHERTYPE_IP: /* shouldn't need a schednetisr(), as */ case WCCP_PROTOCOL_TYPE: /* we are in ip_input */ isr = NETISR_IP; break; #ifdef NETATALK case ETHERTYPE_ATALK: isr = NETISR_ATALK1; break; #endif case ETHERTYPE_IPV6: /* FALLTHROUGH */ default: /* others not yet supported */ return (0); } break; default: /* others not yet supported */ return (0); } if (hlen > m->m_pkthdr.len) { m_freem(m); return (EINVAL); } m_adj(m, hlen); m->m_pkthdr.len -= hlen; if (sc->sc_if.if_bpf) { u_int32_t af = AF_INET; bpf_mtap2(sc->sc_if.if_bpf, &af, sizeof(af), m); } m->m_pkthdr.rcvif = &sc->sc_if; netisr_dispatch(isr, m); return (1); /* packet is done, no further processing needed */ } /* * 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 */ void #if __STDC__ gre_mobile_input(struct mbuf *m, ...) #else gre_mobile_input(m, va_alist) struct mbuf *m; va_dcl #endif { struct ip *ip; struct mobip_h *mip; struct gre_softc *sc; int hlen; va_list ap; int msiz; va_start(ap, m); hlen = va_arg(ap, int); va_end(ap); if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) { /* No matching tunnel or tunnel is down. */ m_freem(m); return; } if (m->m_len < sizeof(*mip)) { m = m_pullup(m, sizeof(*mip)); if (m == NULL) return; } ip = mtod(m, struct ip *); mip = mtod(m, struct mobip_h *); sc->sc_if.if_ipackets++; sc->sc_if.if_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; 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; } 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 * already converted into host byteorder and also decreases * it by the lengh of IP header, however, ip_input() expects * that this field is in the original format (network byteorder * and full size of IP packet), so that adjust accordingly. */ ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz); ip->ip_sum = 0; ip->ip_sum = in_cksum(m, (ip->ip_hl << 2)); if (sc->sc_if.if_bpf) { u_int32_t af = AF_INET; bpf_mtap2(sc->sc_if.if_bpf, &af, sizeof(af), m); } m->m_pkthdr.rcvif = &sc->sc_if; netisr_dispatch(NETISR_IP, m); } /* * Find the gre interface associated with our src/dst/proto set. */ static struct gre_softc * gre_lookup(m, proto) struct mbuf *m; u_int8_t proto; { struct ip *ip = mtod(m, struct ip *); struct gre_softc *sc; for (sc = LIST_FIRST(&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) && ((sc->sc_if.if_flags & IFF_UP) != 0)) return (sc); } return (NULL); }