1 /* $NetBSD: if_faith.c,v 1.64 2024/09/07 06:17:37 andvar Exp $ */ 2 /* $KAME: if_faith.c,v 1.21 2001/02/20 07:59:26 itojun Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 /* 33 * derived from 34 * @(#)if_loop.c 8.1 (Berkeley) 6/10/93 35 * Id: if_loop.c,v 1.22 1996/06/19 16:24:10 wollman Exp 36 */ 37 38 /* 39 * IPv6-to-IPv4 TCP relay capturing interface 40 */ 41 42 #include <sys/cdefs.h> 43 __KERNEL_RCSID(0, "$NetBSD: if_faith.c,v 1.64 2024/09/07 06:17:37 andvar Exp $"); 44 45 #ifdef _KERNEL_OPT 46 #include "opt_inet.h" 47 #endif 48 49 #include <sys/param.h> 50 #include <sys/systm.h> 51 #include <sys/kernel.h> 52 #include <sys/mbuf.h> 53 #include <sys/socket.h> 54 #include <sys/errno.h> 55 #include <sys/ioctl.h> 56 #include <sys/time.h> 57 #include <sys/queue.h> 58 #include <sys/device.h> 59 #include <sys/module.h> 60 #include <sys/atomic.h> 61 62 #include <sys/cpu.h> 63 64 #include <net/if.h> 65 #include <net/if_types.h> 66 #include <net/route.h> 67 #include <net/bpf.h> 68 #include <net/if_faith.h> 69 70 #ifdef INET 71 #include <netinet/in.h> 72 #include <netinet/in_systm.h> 73 #include <netinet/in_var.h> 74 #include <netinet/ip.h> 75 #endif 76 77 #ifdef INET6 78 #ifndef INET 79 #include <netinet/in.h> 80 #endif 81 #include <netinet6/in6_var.h> 82 #include <netinet/ip6.h> 83 #include <netinet6/ip6_var.h> 84 #endif 85 86 #include "ioconf.h" 87 88 static int faithioctl(struct ifnet *, u_long, void *); 89 static int faithoutput(struct ifnet *, struct mbuf *, 90 const struct sockaddr *, const struct rtentry *); 91 static void faithrtrequest(int, struct rtentry *, 92 const struct rt_addrinfo *); 93 94 static int faith_clone_create(struct if_clone *, int); 95 static int faith_clone_destroy(struct ifnet *); 96 97 static struct if_clone faith_cloner = 98 IF_CLONE_INITIALIZER("faith", faith_clone_create, faith_clone_destroy); 99 100 #define FAITHMTU 1500 101 102 static u_int faith_count; 103 104 /* ARGSUSED */ 105 void 106 faithattach(int count) 107 { 108 109 /* 110 * Nothing to do here, initialization is handled by the 111 * module initialization code in faithinit() below). 112 */ 113 } 114 115 static void 116 faithinit(void) 117 { 118 if_clone_attach(&faith_cloner); 119 } 120 121 static int 122 faithdetach(void) 123 { 124 int error = 0; 125 126 if (faith_count != 0) 127 error = EBUSY; 128 129 if (error == 0) 130 if_clone_detach(&faith_cloner); 131 132 return error; 133 } 134 135 static int 136 faith_clone_create(struct if_clone *ifc, int unit) 137 { 138 struct ifnet *ifp; 139 140 ifp = if_alloc(IFT_FAITH); 141 142 if_initname(ifp, ifc->ifc_name, unit); 143 144 ifp->if_mtu = FAITHMTU; 145 /* Change to BROADCAST experimentally to announce its prefix. */ 146 ifp->if_flags = /* IFF_LOOPBACK */ IFF_BROADCAST | IFF_MULTICAST; 147 ifp->if_ioctl = faithioctl; 148 ifp->if_output = faithoutput; 149 ifp->if_type = IFT_FAITH; 150 ifp->if_hdrlen = 0; 151 ifp->if_addrlen = 0; 152 ifp->if_dlt = DLT_NULL; 153 if_attach(ifp); 154 if_alloc_sadl(ifp); 155 bpf_attach(ifp, DLT_NULL, sizeof(u_int)); 156 atomic_inc_uint(&faith_count); 157 return (0); 158 } 159 160 int 161 faith_clone_destroy(struct ifnet *ifp) 162 { 163 164 bpf_detach(ifp); 165 if_detach(ifp); 166 if_free(ifp); 167 168 atomic_dec_uint(&faith_count); 169 return (0); 170 } 171 172 static int 173 faithoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 174 const struct rtentry *rt) 175 { 176 pktqueue_t *pktq; 177 size_t pktlen; 178 int s, error; 179 uint32_t af; 180 181 if ((m->m_flags & M_PKTHDR) == 0) 182 panic("faithoutput no HDR"); 183 af = dst->sa_family; 184 /* BPF write needs to be handled specially */ 185 if (af == AF_UNSPEC) { 186 af = *(mtod(m, int *)); 187 m_adj(m, sizeof(int)); 188 } 189 190 bpf_mtap_af(ifp, af, m, BPF_D_OUT); 191 192 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 193 m_freem(m); 194 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 195 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 196 } 197 pktlen = m->m_pkthdr.len; 198 if_statadd2(ifp, if_opackets, 1, if_obytes, pktlen); 199 switch (af) { 200 #ifdef INET 201 case AF_INET: 202 pktq = ip_pktq; 203 break; 204 #endif 205 #ifdef INET6 206 case AF_INET6: 207 pktq = ip6_pktq; 208 break; 209 #endif 210 default: 211 m_freem(m); 212 return EAFNOSUPPORT; 213 } 214 215 /* XXX do we need more sanity checks? */ 216 KASSERT(pktq != NULL); 217 m_set_rcvif(m, ifp); 218 219 s = splnet(); 220 if (__predict_true(pktq_enqueue(pktq, m, 0))) { 221 if_statadd2(ifp, if_ipackets, 1, if_ibytes, pktlen); 222 error = 0; 223 } else { 224 m_freem(m); 225 error = ENOBUFS; 226 } 227 splx(s); 228 229 return error; 230 } 231 232 /* ARGSUSED */ 233 static void 234 faithrtrequest(int cmd, struct rtentry *rt, 235 const struct rt_addrinfo *info) 236 { 237 if (rt) 238 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 239 } 240 241 /* 242 * Process an ioctl request. 243 */ 244 /* ARGSUSED */ 245 static int 246 faithioctl(struct ifnet *ifp, u_long cmd, void *data) 247 { 248 struct ifaddr *ifa; 249 struct ifreq *ifr = (struct ifreq *)data; 250 int error = 0; 251 252 switch (cmd) { 253 254 case SIOCINITIFADDR: 255 ifa = (struct ifaddr *)data; 256 ifa->ifa_rtrequest = faithrtrequest; 257 ifp->if_flags |= IFF_UP | IFF_RUNNING; 258 /* 259 * Everything else is done at a higher level. 260 */ 261 break; 262 263 case SIOCADDMULTI: 264 case SIOCDELMULTI: 265 if (ifr == 0) { 266 error = EAFNOSUPPORT; /* XXX */ 267 break; 268 } 269 switch (ifr->ifr_addr.sa_family) { 270 #ifdef INET 271 case AF_INET: 272 break; 273 #endif 274 #ifdef INET6 275 case AF_INET6: 276 break; 277 #endif 278 279 default: 280 error = EAFNOSUPPORT; 281 break; 282 } 283 break; 284 285 default: 286 if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET) 287 error = 0; 288 break; 289 } 290 return (error); 291 } 292 293 #ifdef INET6 294 /* 295 * XXX could be slow 296 * XXX could be layer violation to call sys/net from sys/netinet6 297 */ 298 int 299 faithprefix(struct in6_addr *in6) 300 { 301 struct rtentry *rt; 302 struct sockaddr_in6 sin6; 303 int ret; 304 305 if (ip6_keepfaith == 0) 306 return 0; 307 308 memset(&sin6, 0, sizeof(sin6)); 309 sin6.sin6_family = AF_INET6; 310 sin6.sin6_len = sizeof(struct sockaddr_in6); 311 sin6.sin6_addr = *in6; 312 rt = rtalloc1((struct sockaddr *)&sin6, 0); 313 if (rt && rt->rt_ifp && rt->rt_ifp->if_type == IFT_FAITH && 314 (rt->rt_ifp->if_flags & IFF_UP) != 0) 315 ret = 1; 316 else 317 ret = 0; 318 if (rt) 319 rt_unref(rt); 320 return ret; 321 } 322 #endif 323 324 /* 325 * Module infrastructure 326 */ 327 #include "if_module.h" 328 329 IF_MODULE(MODULE_CLASS_DRIVER, faith, NULL) 330