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 #include <sys/proc.h> 44 45 #include <net/if.h> 46 #include <net/if_var.h> 47 #include <net/vnet.h> 48 49 #include <netinet/in.h> 50 #ifdef INET 51 #include <net/ethernet.h> 52 #include <netinet/ip.h> 53 #endif 54 #include <netinet/ip_encap.h> 55 #include <netinet/ip6.h> 56 #include <netinet6/ip6_var.h> 57 #include <netinet6/in6_var.h> 58 #include <netinet6/scope6_var.h> 59 #include <net/if_gre.h> 60 61 VNET_DEFINE(int, ip6_gre_hlim) = IPV6_DEFHLIM; 62 #define V_ip6_gre_hlim VNET(ip6_gre_hlim) 63 64 SYSCTL_DECL(_net_inet6_ip6); 65 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, grehlim, CTLFLAG_VNET | CTLFLAG_RW, 66 &VNET_NAME(ip6_gre_hlim), 0, "Default hop limit for encapsulated packets"); 67 68 VNET_DEFINE_STATIC(struct gre_list *, ipv6_hashtbl) = NULL; 69 #define V_ipv6_hashtbl VNET(ipv6_hashtbl) 70 #define GRE_HASH(src, dst) (V_ipv6_hashtbl[\ 71 in6_gre_hashval((src), (dst)) & (GRE_HASH_SIZE - 1)]) 72 #define GRE_HASH_SC(sc) GRE_HASH(&(sc)->gre_oip6.ip6_src,\ 73 &(sc)->gre_oip6.ip6_dst) 74 75 static uint32_t 76 in6_gre_hashval(const struct in6_addr *src, const struct in6_addr *dst) 77 { 78 uint32_t ret; 79 80 ret = fnv_32_buf(src, sizeof(*src), FNV1_32_INIT); 81 return (fnv_32_buf(dst, sizeof(*dst), ret)); 82 } 83 84 static int 85 in6_gre_checkdup(const struct gre_softc *sc, const struct in6_addr *src, 86 const struct in6_addr *dst) 87 { 88 struct gre_softc *tmp; 89 90 if (sc->gre_family == AF_INET6 && 91 IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_src, src) && 92 IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_dst, dst)) 93 return (EEXIST); 94 95 CK_LIST_FOREACH(tmp, &GRE_HASH(src, dst), chain) { 96 if (tmp == sc) 97 continue; 98 if (IN6_ARE_ADDR_EQUAL(&tmp->gre_oip6.ip6_src, src) && 99 IN6_ARE_ADDR_EQUAL(&tmp->gre_oip6.ip6_dst, dst)) 100 return (EADDRNOTAVAIL); 101 } 102 return (0); 103 } 104 105 static int 106 in6_gre_lookup(const struct mbuf *m, int off, int proto, void **arg) 107 { 108 const struct ip6_hdr *ip6; 109 struct gre_softc *sc; 110 111 if (V_ipv6_hashtbl == NULL) 112 return (0); 113 114 MPASS(in_epoch(net_epoch_preempt)); 115 ip6 = mtod(m, const struct ip6_hdr *); 116 CK_LIST_FOREACH(sc, &GRE_HASH(&ip6->ip6_dst, &ip6->ip6_src), chain) { 117 /* 118 * This is an inbound packet, its ip6_dst is source address 119 * in softc. 120 */ 121 if (IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_src, 122 &ip6->ip6_dst) && 123 IN6_ARE_ADDR_EQUAL(&sc->gre_oip6.ip6_dst, 124 &ip6->ip6_src)) { 125 if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0) 126 return (0); 127 *arg = sc; 128 return (ENCAP_DRV_LOOKUP); 129 } 130 } 131 return (0); 132 } 133 134 static void 135 in6_gre_attach(struct gre_softc *sc) 136 { 137 138 sc->gre_hlen = sizeof(struct greip6); 139 sc->gre_oip6.ip6_vfc = IPV6_VERSION; 140 sc->gre_oip6.ip6_nxt = IPPROTO_GRE; 141 gre_updatehdr(sc, &sc->gre_gi6hdr->gi6_gre); 142 CK_LIST_INSERT_HEAD(&GRE_HASH_SC(sc), sc, chain); 143 } 144 145 void 146 in6_gre_setopts(struct gre_softc *sc, u_long cmd, uint32_t value) 147 { 148 149 MPASS(cmd == GRESKEY || cmd == GRESOPTS); 150 151 /* NOTE: we are protected with gre_ioctl_sx lock */ 152 MPASS(sc->gre_family == AF_INET6); 153 CK_LIST_REMOVE(sc, chain); 154 GRE_WAIT(); 155 if (cmd == GRESKEY) 156 sc->gre_key = value; 157 else 158 sc->gre_options = value; 159 in6_gre_attach(sc); 160 } 161 162 int 163 in6_gre_ioctl(struct gre_softc *sc, u_long cmd, caddr_t data) 164 { 165 struct in6_ifreq *ifr = (struct in6_ifreq *)data; 166 struct sockaddr_in6 *dst, *src; 167 struct ip6_hdr *ip6; 168 int error; 169 170 /* NOTE: we are protected with gre_ioctl_sx lock */ 171 error = EINVAL; 172 switch (cmd) { 173 case SIOCSIFPHYADDR_IN6: 174 src = &((struct in6_aliasreq *)data)->ifra_addr; 175 dst = &((struct in6_aliasreq *)data)->ifra_dstaddr; 176 177 /* sanity checks */ 178 if (src->sin6_family != dst->sin6_family || 179 src->sin6_family != AF_INET6 || 180 src->sin6_len != dst->sin6_len || 181 src->sin6_len != sizeof(*src)) 182 break; 183 if (IN6_IS_ADDR_UNSPECIFIED(&src->sin6_addr) || 184 IN6_IS_ADDR_UNSPECIFIED(&dst->sin6_addr)) { 185 error = EADDRNOTAVAIL; 186 break; 187 } 188 /* 189 * Check validity of the scope zone ID of the 190 * addresses, and convert it into the kernel 191 * internal form if necessary. 192 */ 193 if ((error = sa6_embedscope(src, 0)) != 0 || 194 (error = sa6_embedscope(dst, 0)) != 0) 195 break; 196 197 if (V_ipv6_hashtbl == NULL) 198 V_ipv6_hashtbl = gre_hashinit(); 199 error = in6_gre_checkdup(sc, &src->sin6_addr, 200 &dst->sin6_addr); 201 if (error == EADDRNOTAVAIL) 202 break; 203 if (error == EEXIST) { 204 /* Addresses are the same. Just return. */ 205 error = 0; 206 break; 207 } 208 ip6 = malloc(sizeof(struct greip6) + 3 * sizeof(uint32_t), 209 M_GRE, M_WAITOK | M_ZERO); 210 ip6->ip6_src = src->sin6_addr; 211 ip6->ip6_dst = dst->sin6_addr; 212 if (sc->gre_family != 0) { 213 /* Detach existing tunnel first */ 214 CK_LIST_REMOVE(sc, chain); 215 GRE_WAIT(); 216 free(sc->gre_hdr, M_GRE); 217 /* XXX: should we notify about link state change? */ 218 } 219 sc->gre_family = AF_INET6; 220 sc->gre_hdr = ip6; 221 sc->gre_oseq = 0; 222 sc->gre_iseq = UINT32_MAX; 223 in6_gre_attach(sc); 224 break; 225 case SIOCGIFPSRCADDR_IN6: 226 case SIOCGIFPDSTADDR_IN6: 227 if (sc->gre_family != AF_INET6) { 228 error = EADDRNOTAVAIL; 229 break; 230 } 231 src = (struct sockaddr_in6 *)&ifr->ifr_addr; 232 memset(src, 0, sizeof(*src)); 233 src->sin6_family = AF_INET6; 234 src->sin6_len = sizeof(*src); 235 src->sin6_addr = (cmd == SIOCGIFPSRCADDR_IN6) ? 236 sc->gre_oip6.ip6_src: sc->gre_oip6.ip6_dst; 237 error = prison_if(curthread->td_ucred, (struct sockaddr *)src); 238 if (error == 0) 239 error = sa6_recoverscope(src); 240 if (error != 0) 241 memset(src, 0, sizeof(*src)); 242 break; 243 } 244 return (error); 245 } 246 247 int 248 in6_gre_output(struct mbuf *m, int af __unused, int hlen __unused) 249 { 250 struct greip6 *gi6; 251 252 gi6 = mtod(m, struct greip6 *); 253 gi6->gi6_ip6.ip6_hlim = V_ip6_gre_hlim; 254 return (ip6_output(m, NULL, NULL, IPV6_MINMTU, NULL, NULL, NULL)); 255 } 256 257 static const struct encaptab *ecookie = NULL; 258 static const struct encap_config ipv6_encap_cfg = { 259 .proto = IPPROTO_GRE, 260 .min_length = sizeof(struct greip6) + 261 #ifdef INET 262 sizeof(struct ip), 263 #else 264 sizeof(struct ip6_hdr), 265 #endif 266 .exact_match = ENCAP_DRV_LOOKUP, 267 .lookup = in6_gre_lookup, 268 .input = gre_input 269 }; 270 271 void 272 in6_gre_init(void) 273 { 274 275 if (!IS_DEFAULT_VNET(curvnet)) 276 return; 277 ecookie = ip6_encap_attach(&ipv6_encap_cfg, NULL, M_WAITOK); 278 } 279 280 void 281 in6_gre_uninit(void) 282 { 283 284 if (IS_DEFAULT_VNET(curvnet)) 285 ip6_encap_detach(ecookie); 286 if (V_ipv6_hashtbl != NULL) 287 gre_hashdestroy(V_ipv6_hashtbl); 288 } 289