1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-NetBSD 3 * 4 * Copyright (c) 1998 The NetBSD Foundation, Inc. 5 * Copyright (c) 2014, 2018 Andrey V. Elsukov <ae@FreeBSD.org> 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Heiko W.Rupp <hwr@pilhuhn.de> 10 * 11 * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de> 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 * POSSIBILITY OF SUCH DAMAGE. 33 * 34 * $NetBSD: ip_gre.c,v 1.29 2003/09/05 23:02:43 itojun Exp $ 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_inet.h" 41 #include "opt_inet6.h" 42 43 #include <sys/param.h> 44 #include <sys/jail.h> 45 #include <sys/systm.h> 46 #include <sys/socket.h> 47 #include <sys/sockio.h> 48 #include <sys/mbuf.h> 49 #include <sys/errno.h> 50 #include <sys/kernel.h> 51 #include <sys/sysctl.h> 52 #include <sys/malloc.h> 53 #include <sys/proc.h> 54 55 #include <net/if.h> 56 #include <net/if_var.h> 57 #include <net/vnet.h> 58 59 #include <netinet/in.h> 60 #include <netinet/in_var.h> 61 #include <netinet/ip.h> 62 #include <netinet/ip_encap.h> 63 #include <netinet/ip_var.h> 64 65 #ifdef INET6 66 #include <netinet/ip6.h> 67 #endif 68 69 #include <net/if_gre.h> 70 71 #define GRE_TTL 30 72 VNET_DEFINE(int, ip_gre_ttl) = GRE_TTL; 73 #define V_ip_gre_ttl VNET(ip_gre_ttl) 74 SYSCTL_INT(_net_inet_ip, OID_AUTO, grettl, CTLFLAG_VNET | CTLFLAG_RW, 75 &VNET_NAME(ip_gre_ttl), 0, "Default TTL value for encapsulated packets"); 76 77 static VNET_DEFINE(struct gre_list *, ipv4_hashtbl) = NULL; 78 #define V_ipv4_hashtbl VNET(ipv4_hashtbl) 79 #define GRE_HASH(src, dst) (V_ipv4_hashtbl[\ 80 in_gre_hashval((src), (dst)) & (GRE_HASH_SIZE - 1)]) 81 #define GRE_HASH_SC(sc) GRE_HASH((sc)->gre_oip.ip_src.s_addr,\ 82 (sc)->gre_oip.ip_dst.s_addr) 83 84 static uint32_t 85 in_gre_hashval(in_addr_t src, in_addr_t dst) 86 { 87 uint32_t ret; 88 89 ret = fnv_32_buf(&src, sizeof(src), FNV1_32_INIT); 90 return (fnv_32_buf(&dst, sizeof(dst), ret)); 91 } 92 93 static int 94 in_gre_checkdup(const struct gre_softc *sc, in_addr_t src, in_addr_t dst) 95 { 96 struct gre_softc *tmp; 97 98 if (sc->gre_family == AF_INET && 99 sc->gre_oip.ip_src.s_addr == src && 100 sc->gre_oip.ip_dst.s_addr == dst) 101 return (EEXIST); 102 103 CK_LIST_FOREACH(tmp, &GRE_HASH(src, dst), chain) { 104 if (tmp == sc) 105 continue; 106 if (tmp->gre_oip.ip_src.s_addr == src && 107 tmp->gre_oip.ip_dst.s_addr == dst) 108 return (EADDRNOTAVAIL); 109 } 110 return (0); 111 } 112 113 static int 114 in_gre_lookup(const struct mbuf *m, int off, int proto, void **arg) 115 { 116 const struct ip *ip; 117 struct gre_softc *sc; 118 119 if (V_ipv4_hashtbl == NULL) 120 return (0); 121 122 MPASS(in_epoch(net_epoch_preempt)); 123 ip = mtod(m, const struct ip *); 124 CK_LIST_FOREACH(sc, &GRE_HASH(ip->ip_dst.s_addr, 125 ip->ip_src.s_addr), chain) { 126 /* 127 * This is an inbound packet, its ip_dst is source address 128 * in softc. 129 */ 130 if (sc->gre_oip.ip_src.s_addr == ip->ip_dst.s_addr && 131 sc->gre_oip.ip_dst.s_addr == ip->ip_src.s_addr) { 132 if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0) 133 return (0); 134 *arg = sc; 135 return (ENCAP_DRV_LOOKUP); 136 } 137 } 138 return (0); 139 } 140 141 static void 142 in_gre_attach(struct gre_softc *sc) 143 { 144 145 sc->gre_hlen = sizeof(struct greip); 146 sc->gre_oip.ip_v = IPVERSION; 147 sc->gre_oip.ip_hl = sizeof(struct ip) >> 2; 148 sc->gre_oip.ip_p = IPPROTO_GRE; 149 gre_updatehdr(sc, &sc->gre_gihdr->gi_gre); 150 CK_LIST_INSERT_HEAD(&GRE_HASH_SC(sc), sc, chain); 151 } 152 153 void 154 in_gre_setopts(struct gre_softc *sc, u_long cmd, uint32_t value) 155 { 156 157 MPASS(cmd == GRESKEY || cmd == GRESOPTS); 158 159 /* NOTE: we are protected with gre_ioctl_sx lock */ 160 MPASS(sc->gre_family == AF_INET); 161 CK_LIST_REMOVE(sc, chain); 162 GRE_WAIT(); 163 if (cmd == GRESKEY) 164 sc->gre_key = value; 165 else 166 sc->gre_options = value; 167 in_gre_attach(sc); 168 } 169 170 int 171 in_gre_ioctl(struct gre_softc *sc, u_long cmd, caddr_t data) 172 { 173 struct ifreq *ifr = (struct ifreq *)data; 174 struct sockaddr_in *dst, *src; 175 struct ip *ip; 176 int error; 177 178 /* NOTE: we are protected with gre_ioctl_sx lock */ 179 error = EINVAL; 180 switch (cmd) { 181 case SIOCSIFPHYADDR: 182 src = &((struct in_aliasreq *)data)->ifra_addr; 183 dst = &((struct in_aliasreq *)data)->ifra_dstaddr; 184 185 /* sanity checks */ 186 if (src->sin_family != dst->sin_family || 187 src->sin_family != AF_INET || 188 src->sin_len != dst->sin_len || 189 src->sin_len != sizeof(*src)) 190 break; 191 if (src->sin_addr.s_addr == INADDR_ANY || 192 dst->sin_addr.s_addr == INADDR_ANY) { 193 error = EADDRNOTAVAIL; 194 break; 195 } 196 if (V_ipv4_hashtbl == NULL) 197 V_ipv4_hashtbl = gre_hashinit(); 198 error = in_gre_checkdup(sc, src->sin_addr.s_addr, 199 dst->sin_addr.s_addr); 200 if (error == EADDRNOTAVAIL) 201 break; 202 if (error == EEXIST) { 203 /* Addresses are the same. Just return. */ 204 error = 0; 205 break; 206 } 207 ip = malloc(sizeof(struct greip) + 3 * sizeof(uint32_t), 208 M_GRE, M_WAITOK | M_ZERO); 209 ip->ip_src.s_addr = src->sin_addr.s_addr; 210 ip->ip_dst.s_addr = dst->sin_addr.s_addr; 211 if (sc->gre_family != 0) { 212 /* Detach existing tunnel first */ 213 CK_LIST_REMOVE(sc, chain); 214 GRE_WAIT(); 215 free(sc->gre_hdr, M_GRE); 216 /* XXX: should we notify about link state change? */ 217 } 218 sc->gre_family = AF_INET; 219 sc->gre_hdr = ip; 220 sc->gre_oseq = 0; 221 sc->gre_iseq = UINT32_MAX; 222 in_gre_attach(sc); 223 break; 224 case SIOCGIFPSRCADDR: 225 case SIOCGIFPDSTADDR: 226 if (sc->gre_family != AF_INET) { 227 error = EADDRNOTAVAIL; 228 break; 229 } 230 src = (struct sockaddr_in *)&ifr->ifr_addr; 231 memset(src, 0, sizeof(*src)); 232 src->sin_family = AF_INET; 233 src->sin_len = sizeof(*src); 234 src->sin_addr = (cmd == SIOCGIFPSRCADDR) ? 235 sc->gre_oip.ip_src: sc->gre_oip.ip_dst; 236 error = prison_if(curthread->td_ucred, (struct sockaddr *)src); 237 if (error != 0) 238 memset(src, 0, sizeof(*src)); 239 break; 240 } 241 return (error); 242 } 243 244 int 245 in_gre_output(struct mbuf *m, int af, int hlen) 246 { 247 struct greip *gi; 248 249 gi = mtod(m, struct greip *); 250 switch (af) { 251 case AF_INET: 252 /* 253 * gre_transmit() has used M_PREPEND() that doesn't guarantee 254 * m_data is contiguous more than hlen bytes. Use m_copydata() 255 * here to avoid m_pullup(). 256 */ 257 m_copydata(m, hlen + offsetof(struct ip, ip_tos), 258 sizeof(u_char), &gi->gi_ip.ip_tos); 259 m_copydata(m, hlen + offsetof(struct ip, ip_id), 260 sizeof(u_short), (caddr_t)&gi->gi_ip.ip_id); 261 break; 262 #ifdef INET6 263 case AF_INET6: 264 gi->gi_ip.ip_tos = 0; /* XXX */ 265 ip_fillid(&gi->gi_ip); 266 break; 267 #endif 268 } 269 gi->gi_ip.ip_ttl = V_ip_gre_ttl; 270 gi->gi_ip.ip_len = htons(m->m_pkthdr.len); 271 return (ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL)); 272 } 273 274 static const struct encaptab *ecookie = NULL; 275 static const struct encap_config ipv4_encap_cfg = { 276 .proto = IPPROTO_GRE, 277 .min_length = sizeof(struct greip) + sizeof(struct ip), 278 .exact_match = ENCAP_DRV_LOOKUP, 279 .lookup = in_gre_lookup, 280 .input = gre_input 281 }; 282 283 void 284 in_gre_init(void) 285 { 286 287 if (!IS_DEFAULT_VNET(curvnet)) 288 return; 289 ecookie = ip_encap_attach(&ipv4_encap_cfg, NULL, M_WAITOK); 290 } 291 292 void 293 in_gre_uninit(void) 294 { 295 296 if (IS_DEFAULT_VNET(curvnet)) 297 ip_encap_detach(ecookie); 298 if (V_ipv4_hashtbl != NULL) 299 gre_hashdestroy(V_ipv4_hashtbl); 300 } 301