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 54 #include <net/if.h> 55 #include <net/if_var.h> 56 #include <net/vnet.h> 57 58 #include <netinet/in.h> 59 #include <netinet/in_var.h> 60 #include <netinet/ip.h> 61 #include <netinet/ip_encap.h> 62 #include <netinet/ip_var.h> 63 64 #ifdef INET6 65 #include <netinet/ip6.h> 66 #endif 67 68 #include <net/if_gre.h> 69 70 #define GRE_TTL 30 71 VNET_DEFINE(int, ip_gre_ttl) = GRE_TTL; 72 #define V_ip_gre_ttl VNET(ip_gre_ttl) 73 SYSCTL_INT(_net_inet_ip, OID_AUTO, grettl, CTLFLAG_VNET | CTLFLAG_RW, 74 &VNET_NAME(ip_gre_ttl), 0, "Default TTL value for encapsulated packets"); 75 76 static VNET_DEFINE(struct gre_list *, ipv4_hashtbl) = NULL; 77 #define V_ipv4_hashtbl VNET(ipv4_hashtbl) 78 #define GRE_HASH(src, dst) (V_ipv4_hashtbl[\ 79 in_gre_hashval((src), (dst)) & (GRE_HASH_SIZE - 1)]) 80 #define GRE_HASH_SC(sc) GRE_HASH((sc)->gre_oip.ip_src.s_addr,\ 81 (sc)->gre_oip.ip_dst.s_addr) 82 83 static uint32_t 84 in_gre_hashval(in_addr_t src, in_addr_t dst) 85 { 86 uint32_t ret; 87 88 ret = fnv_32_buf(&src, sizeof(src), FNV1_32_INIT); 89 return (fnv_32_buf(&dst, sizeof(dst), ret)); 90 } 91 92 static int 93 in_gre_checkdup(const struct gre_softc *sc, in_addr_t src, in_addr_t dst) 94 { 95 struct gre_softc *tmp; 96 97 if (sc->gre_family == AF_INET && 98 sc->gre_oip.ip_src.s_addr == src && 99 sc->gre_oip.ip_dst.s_addr == dst) 100 return (EEXIST); 101 102 CK_LIST_FOREACH(tmp, &GRE_HASH(src, dst), chain) { 103 if (tmp == sc) 104 continue; 105 if (tmp->gre_oip.ip_src.s_addr == src && 106 tmp->gre_oip.ip_dst.s_addr == dst) 107 return (EADDRNOTAVAIL); 108 } 109 return (0); 110 } 111 112 static int 113 in_gre_lookup(const struct mbuf *m, int off, int proto, void **arg) 114 { 115 const struct ip *ip; 116 struct gre_softc *sc; 117 118 if (V_ipv4_hashtbl == NULL) 119 return (0); 120 121 MPASS(in_epoch()); 122 ip = mtod(m, const struct ip *); 123 CK_LIST_FOREACH(sc, &GRE_HASH(ip->ip_dst.s_addr, 124 ip->ip_src.s_addr), chain) { 125 /* 126 * This is an inbound packet, its ip_dst is source address 127 * in softc. 128 */ 129 if (sc->gre_oip.ip_src.s_addr == ip->ip_dst.s_addr && 130 sc->gre_oip.ip_dst.s_addr == ip->ip_src.s_addr) { 131 if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0) 132 return (0); 133 *arg = sc; 134 return (ENCAP_DRV_LOOKUP); 135 } 136 } 137 return (0); 138 } 139 140 static void 141 in_gre_attach(struct gre_softc *sc) 142 { 143 144 sc->gre_hlen = sizeof(struct greip); 145 sc->gre_oip.ip_v = IPVERSION; 146 sc->gre_oip.ip_hl = sizeof(struct ip) >> 2; 147 sc->gre_oip.ip_p = IPPROTO_GRE; 148 gre_updatehdr(sc, &sc->gre_gihdr->gi_gre); 149 CK_LIST_INSERT_HEAD(&GRE_HASH_SC(sc), sc, chain); 150 } 151 152 void 153 in_gre_setopts(struct gre_softc *sc, u_long cmd, uint32_t value) 154 { 155 156 MPASS(cmd == GRESKEY || cmd == GRESOPTS); 157 158 /* NOTE: we are protected with gre_ioctl_sx lock */ 159 MPASS(sc->gre_family == AF_INET); 160 CK_LIST_REMOVE(sc, chain); 161 GRE_WAIT(); 162 if (cmd == GRESKEY) 163 sc->gre_key = value; 164 else 165 sc->gre_options = value; 166 in_gre_attach(sc); 167 } 168 169 int 170 in_gre_ioctl(struct gre_softc *sc, u_long cmd, caddr_t data) 171 { 172 struct ifreq *ifr = (struct ifreq *)data; 173 struct sockaddr_in *dst, *src; 174 struct ip *ip; 175 int error; 176 177 /* NOTE: we are protected with gre_ioctl_sx lock */ 178 error = EINVAL; 179 switch (cmd) { 180 case SIOCSIFPHYADDR: 181 src = &((struct in_aliasreq *)data)->ifra_addr; 182 dst = &((struct in_aliasreq *)data)->ifra_dstaddr; 183 184 /* sanity checks */ 185 if (src->sin_family != dst->sin_family || 186 src->sin_family != AF_INET || 187 src->sin_len != dst->sin_len || 188 src->sin_len != sizeof(*src)) 189 break; 190 if (src->sin_addr.s_addr == INADDR_ANY || 191 dst->sin_addr.s_addr == INADDR_ANY) { 192 error = EADDRNOTAVAIL; 193 break; 194 } 195 if (V_ipv4_hashtbl == NULL) 196 V_ipv4_hashtbl = gre_hashinit(); 197 error = in_gre_checkdup(sc, src->sin_addr.s_addr, 198 dst->sin_addr.s_addr); 199 if (error == EADDRNOTAVAIL) 200 break; 201 if (error == EEXIST) { 202 /* Addresses are the same. Just return. */ 203 error = 0; 204 break; 205 } 206 ip = malloc(sizeof(struct greip) + 3 * sizeof(uint32_t), 207 M_GRE, M_WAITOK | M_ZERO); 208 ip->ip_src.s_addr = src->sin_addr.s_addr; 209 ip->ip_dst.s_addr = dst->sin_addr.s_addr; 210 if (sc->gre_family != 0) { 211 /* Detach existing tunnel first */ 212 CK_LIST_REMOVE(sc, chain); 213 GRE_WAIT(); 214 free(sc->gre_hdr, M_GRE); 215 /* XXX: should we notify about link state change? */ 216 } 217 sc->gre_family = AF_INET; 218 sc->gre_hdr = ip; 219 sc->gre_oseq = 0; 220 sc->gre_iseq = UINT32_MAX; 221 in_gre_attach(sc); 222 break; 223 case SIOCGIFPSRCADDR: 224 case SIOCGIFPDSTADDR: 225 if (sc->gre_family != AF_INET) { 226 error = EADDRNOTAVAIL; 227 break; 228 } 229 src = (struct sockaddr_in *)&ifr->ifr_addr; 230 memset(src, 0, sizeof(*src)); 231 src->sin_family = AF_INET; 232 src->sin_len = sizeof(*src); 233 src->sin_addr = (cmd == SIOCGIFPSRCADDR) ? 234 sc->gre_oip.ip_src: sc->gre_oip.ip_dst; 235 error = prison_if(curthread->td_ucred, (struct sockaddr *)src); 236 if (error != 0) 237 memset(src, 0, sizeof(*src)); 238 break; 239 } 240 return (error); 241 } 242 243 int 244 in_gre_output(struct mbuf *m, int af, int hlen) 245 { 246 struct greip *gi; 247 248 gi = mtod(m, struct greip *); 249 switch (af) { 250 case AF_INET: 251 /* 252 * gre_transmit() has used M_PREPEND() that doesn't guarantee 253 * m_data is contiguous more than hlen bytes. Use m_copydata() 254 * here to avoid m_pullup(). 255 */ 256 m_copydata(m, hlen + offsetof(struct ip, ip_tos), 257 sizeof(u_char), &gi->gi_ip.ip_tos); 258 m_copydata(m, hlen + offsetof(struct ip, ip_id), 259 sizeof(u_short), (caddr_t)&gi->gi_ip.ip_id); 260 break; 261 #ifdef INET6 262 case AF_INET6: 263 gi->gi_ip.ip_tos = 0; /* XXX */ 264 ip_fillid(&gi->gi_ip); 265 break; 266 #endif 267 } 268 gi->gi_ip.ip_ttl = V_ip_gre_ttl; 269 gi->gi_ip.ip_len = htons(m->m_pkthdr.len); 270 return (ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL)); 271 } 272 273 static const struct encaptab *ecookie = NULL; 274 static const struct encap_config ipv4_encap_cfg = { 275 .proto = IPPROTO_GRE, 276 .min_length = sizeof(struct greip) + sizeof(struct ip), 277 .exact_match = ENCAP_DRV_LOOKUP, 278 .lookup = in_gre_lookup, 279 .input = gre_input 280 }; 281 282 void 283 in_gre_init(void) 284 { 285 286 if (!IS_DEFAULT_VNET(curvnet)) 287 return; 288 ecookie = ip_encap_attach(&ipv4_encap_cfg, NULL, M_WAITOK); 289 } 290 291 void 292 in_gre_uninit(void) 293 { 294 295 if (IS_DEFAULT_VNET(curvnet)) 296 ip_encap_detach(ecookie); 297 if (V_ipv4_hashtbl != NULL) 298 gre_hashdestroy(V_ipv4_hashtbl); 299 } 300