1 /*- 2 * Copyright (c) 2014, 2018 Andrey V. Elsukov <ae@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include "opt_inet.h" 31 #include "opt_inet6.h" 32 33 #include <sys/param.h> 34 #include <sys/jail.h> 35 #include <sys/systm.h> 36 #include <sys/socket.h> 37 #include <sys/sockio.h> 38 #include <sys/mbuf.h> 39 #include <sys/errno.h> 40 #include <sys/kernel.h> 41 #include <sys/sysctl.h> 42 #include <sys/malloc.h> 43 44 #include <net/if.h> 45 #include <net/if_var.h> 46 #include <net/vnet.h> 47 48 #include <netinet/in.h> 49 #ifdef INET 50 #include <net/ethernet.h> 51 #include <netinet/ip.h> 52 #endif 53 #include <netinet/ip_encap.h> 54 #include <netinet/ip6.h> 55 #include <netinet6/ip6_var.h> 56 #include <netinet6/in6_var.h> 57 #include <netinet6/scope6_var.h> 58 #include <net/if_gre.h> 59 60 VNET_DEFINE(int, ip6_gre_hlim) = IPV6_DEFHLIM; 61 #define V_ip6_gre_hlim VNET(ip6_gre_hlim) 62 63 SYSCTL_DECL(_net_inet6_ip6); 64 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, grehlim, CTLFLAG_VNET | CTLFLAG_RW, 65 &VNET_NAME(ip6_gre_hlim), 0, "Default hop limit for encapsulated packets"); 66 67 static VNET_DEFINE(struct gre_list *, ipv6_hashtbl) = NULL; 68 #define V_ipv6_hashtbl VNET(ipv6_hashtbl) 69 #define GRE_HASH(src, dst) (V_ipv6_hashtbl[\ 70 in6_gre_hashval((src), (dst)) & (GRE_HASH_SIZE - 1)]) 71 #define GRE_HASH_SC(sc) GRE_HASH(&(sc)->gre_oip6.ip6_src,\ 72 &(sc)->gre_oip6.ip6_dst) 73 74 static uint32_t 75 in6_gre_hashval(const struct in6_addr *src, const struct in6_addr *dst) 76 { 77 uint32_t ret; 78 79 ret = fnv_32_buf(src, sizeof(*src), FNV1_32_INIT); 80 return (fnv_32_buf(dst, sizeof(*dst), ret)); 81 } 82 83 static int 84 in6_gre_checkdup(const struct gre_softc *sc, const struct in6_addr *src, 85 const struct in6_addr *dst) 86 { 87 struct gre_softc *tmp; 88 89 if (sc->gre_family == AF_INET6 && 90 IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_src, src) && 91 IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_dst, dst)) 92 return (EEXIST); 93 94 CK_LIST_FOREACH(tmp, &GRE_HASH(src, dst), chain) { 95 if (tmp == sc) 96 continue; 97 if (IN6_ARE_ADDR_EQUAL(&tmp->gre_oip6.ip6_src, src) && 98 IN6_ARE_ADDR_EQUAL(&tmp->gre_oip6.ip6_dst, dst)) 99 return (EADDRNOTAVAIL); 100 } 101 return (0); 102 } 103 104 static int 105 in6_gre_lookup(const struct mbuf *m, int off, int proto, void **arg) 106 { 107 const struct ip6_hdr *ip6; 108 struct gre_softc *sc; 109 110 if (V_ipv6_hashtbl == NULL) 111 return (0); 112 113 MPASS(in_epoch()); 114 ip6 = mtod(m, const struct ip6_hdr *); 115 CK_LIST_FOREACH(sc, &GRE_HASH(&ip6->ip6_dst, &ip6->ip6_src), chain) { 116 /* 117 * This is an inbound packet, its ip6_dst is source address 118 * in softc. 119 */ 120 if (IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_src, 121 &ip6->ip6_dst) && 122 IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_dst, 123 &ip6->ip6_src)) { 124 if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0) 125 return (0); 126 *arg = sc; 127 return (ENCAP_DRV_LOOKUP); 128 } 129 } 130 return (0); 131 } 132 133 static void 134 in6_gre_attach(struct gre_softc *sc) 135 { 136 137 sc->gre_hlen = sizeof(struct greip6); 138 sc->gre_oip6.ip6_vfc = IPV6_VERSION; 139 sc->gre_oip6.ip6_nxt = IPPROTO_GRE; 140 gre_updatehdr(sc, &sc->gre_gi6hdr->gi6_gre); 141 CK_LIST_INSERT_HEAD(&GRE_HASH_SC(sc), sc, chain); 142 } 143 144 void 145 in6_gre_setopts(struct gre_softc *sc, u_long cmd, uint32_t value) 146 { 147 148 MPASS(cmd == GRESKEY || cmd == GRESOPTS); 149 150 /* NOTE: we are protected with gre_ioctl_sx lock */ 151 MPASS(sc->gre_family == AF_INET6); 152 CK_LIST_REMOVE(sc, chain); 153 GRE_WAIT(); 154 if (cmd == GRESKEY) 155 sc->gre_key = value; 156 else 157 sc->gre_options = value; 158 in6_gre_attach(sc); 159 } 160 161 int 162 in6_gre_ioctl(struct gre_softc *sc, u_long cmd, caddr_t data) 163 { 164 struct in6_ifreq *ifr = (struct in6_ifreq *)data; 165 struct sockaddr_in6 *dst, *src; 166 struct ip6_hdr *ip6; 167 int error; 168 169 /* NOTE: we are protected with gre_ioctl_sx lock */ 170 error = EINVAL; 171 switch (cmd) { 172 case SIOCSIFPHYADDR_IN6: 173 src = &((struct in6_aliasreq *)data)->ifra_addr; 174 dst = &((struct in6_aliasreq *)data)->ifra_dstaddr; 175 176 /* sanity checks */ 177 if (src->sin6_family != dst->sin6_family || 178 src->sin6_family != AF_INET6 || 179 src->sin6_len != dst->sin6_len || 180 src->sin6_len != sizeof(*src)) 181 break; 182 if (IN6_IS_ADDR_UNSPECIFIED(&src->sin6_addr) || 183 IN6_IS_ADDR_UNSPECIFIED(&dst->sin6_addr)) { 184 error = EADDRNOTAVAIL; 185 break; 186 } 187 /* 188 * Check validity of the scope zone ID of the 189 * addresses, and convert it into the kernel 190 * internal form if necessary. 191 */ 192 if ((error = sa6_embedscope(src, 0)) != 0 || 193 (error = sa6_embedscope(dst, 0)) != 0) 194 break; 195 196 if (V_ipv6_hashtbl == NULL) 197 V_ipv6_hashtbl = gre_hashinit(); 198 error = in6_gre_checkdup(sc, &src->sin6_addr, 199 &dst->sin6_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 ip6 = malloc(sizeof(struct greip6) + 3 * sizeof(uint32_t), 208 M_GRE, M_WAITOK | M_ZERO); 209 ip6->ip6_src = src->sin6_addr; 210 ip6->ip6_dst = dst->sin6_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_INET6; 219 sc->gre_hdr = ip6; 220 sc->gre_oseq = 0; 221 sc->gre_iseq = UINT32_MAX; 222 in6_gre_attach(sc); 223 break; 224 case SIOCGIFPSRCADDR_IN6: 225 case SIOCGIFPDSTADDR_IN6: 226 if (sc->gre_family != AF_INET6) { 227 error = EADDRNOTAVAIL; 228 break; 229 } 230 src = (struct sockaddr_in6 *)&ifr->ifr_addr; 231 memset(src, 0, sizeof(*src)); 232 src->sin6_family = AF_INET6; 233 src->sin6_len = sizeof(*src); 234 src->sin6_addr = (cmd == SIOCGIFPSRCADDR_IN6) ? 235 sc->gre_oip6.ip6_src: sc->gre_oip6.ip6_dst; 236 error = prison_if(curthread->td_ucred, (struct sockaddr *)src); 237 if (error == 0) 238 error = sa6_recoverscope(src); 239 if (error != 0) 240 memset(src, 0, sizeof(*src)); 241 break; 242 } 243 return (error); 244 } 245 246 int 247 in6_gre_output(struct mbuf *m, int af __unused, int hlen __unused) 248 { 249 struct greip6 *gi6; 250 251 gi6 = mtod(m, struct greip6 *); 252 gi6->gi6_ip6.ip6_hlim = V_ip6_gre_hlim; 253 return (ip6_output(m, NULL, NULL, IPV6_MINMTU, NULL, NULL, NULL)); 254 } 255 256 static const struct encaptab *ecookie = NULL; 257 static const struct encap_config ipv6_encap_cfg = { 258 .proto = IPPROTO_GRE, 259 .min_length = sizeof(struct greip6) + 260 #ifdef INET 261 sizeof(struct ip), 262 #else 263 sizeof(struct ip6_hdr), 264 #endif 265 .exact_match = ENCAP_DRV_LOOKUP, 266 .lookup = in6_gre_lookup, 267 .input = gre_input 268 }; 269 270 void 271 in6_gre_init(void) 272 { 273 274 if (!IS_DEFAULT_VNET(curvnet)) 275 return; 276 ecookie = ip6_encap_attach(&ipv6_encap_cfg, NULL, M_WAITOK); 277 } 278 279 void 280 in6_gre_uninit(void) 281 { 282 283 if (IS_DEFAULT_VNET(curvnet)) 284 ip6_encap_detach(ecookie); 285 if (V_ipv6_hashtbl != NULL) 286 gre_hashdestroy(V_ipv6_hashtbl); 287 } 288