| 1 | /* |
| 2 | * Copyright (c) 1982, 1986, 1993 |
| 3 | * The Regents of the University of California. 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 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * 3. All advertising materials mentioning features or use of this software |
| 14 | * must display the following acknowledgement: |
| 15 | * This product includes software developed by the University of |
| 16 | * California, Berkeley and its contributors. |
| 17 | * 4. Neither the name of the University nor the names of its contributors |
| 18 | * may be used to endorse or promote products derived from this software |
| 19 | * without specific prior written permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 31 | * SUCH DAMAGE. |
| 32 | * |
| 33 | * @(#)if_loop.c 8.1 (Berkeley) 6/10/93 |
| 34 | * $FreeBSD: src/sys/net/if_loop.c,v 1.47.2.9 2004/02/08 08:40:24 silby Exp $ |
| 35 | */ |
| 36 | |
| 37 | /* |
| 38 | * Loopback interface driver for protocol testing and timing. |
| 39 | */ |
| 40 | #include "use_loop.h" |
| 41 | |
| 42 | #include "opt_inet.h" |
| 43 | #include "opt_inet6.h" |
| 44 | #include "opt_ipx.h" |
| 45 | |
| 46 | #include <sys/param.h> |
| 47 | #include <sys/systm.h> |
| 48 | #include <sys/kernel.h> |
| 49 | #include <sys/lock.h> |
| 50 | #include <sys/mbuf.h> |
| 51 | #include <sys/socket.h> |
| 52 | #include <sys/sockio.h> |
| 53 | |
| 54 | #include <sys/mplock2.h> |
| 55 | |
| 56 | #include <net/if.h> |
| 57 | #include <net/if_types.h> |
| 58 | #include <net/ifq_var.h> |
| 59 | #include <net/netisr.h> |
| 60 | #include <net/route.h> |
| 61 | #include <net/bpf.h> |
| 62 | #include <net/bpfdesc.h> |
| 63 | |
| 64 | #ifdef INET |
| 65 | #include <netinet/in.h> |
| 66 | #include <netinet/in_var.h> |
| 67 | #endif |
| 68 | |
| 69 | #ifdef IPX |
| 70 | #include <netproto/ipx/ipx.h> |
| 71 | #include <netproto/ipx/ipx_if.h> |
| 72 | #endif |
| 73 | |
| 74 | #ifdef INET6 |
| 75 | #ifndef INET |
| 76 | #include <netinet/in.h> |
| 77 | #endif |
| 78 | #include <netinet6/in6_var.h> |
| 79 | #include <netinet/ip6.h> |
| 80 | #endif |
| 81 | |
| 82 | static void loopattach(void *); |
| 83 | static int looutput(struct ifnet *, struct mbuf *, struct sockaddr *, |
| 84 | struct rtentry *); |
| 85 | static int loioctl(struct ifnet *, u_long, caddr_t, struct ucred *); |
| 86 | static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); |
| 87 | #ifdef ALTQ |
| 88 | static void lo_altqstart(struct ifnet *, struct ifaltq_subque *); |
| 89 | #endif |
| 90 | PSEUDO_SET(loopattach, if_loop); |
| 91 | |
| 92 | #ifdef TINY_LOMTU |
| 93 | #define LOMTU (1024+512) |
| 94 | #elif defined(LARGE_LOMTU) |
| 95 | #define LOMTU 131072 |
| 96 | #else |
| 97 | #define LOMTU 16384 |
| 98 | #endif |
| 99 | |
| 100 | #define LO_CSUM_FEATURES (CSUM_IP | CSUM_UDP | CSUM_TCP) |
| 101 | |
| 102 | struct ifnet loif[NLOOP]; |
| 103 | |
| 104 | /* ARGSUSED */ |
| 105 | static void |
| 106 | loopattach(void *dummy) |
| 107 | { |
| 108 | struct ifnet *ifp; |
| 109 | int i; |
| 110 | |
| 111 | for (i = 0, ifp = loif; i < NLOOP; i++, ifp++) { |
| 112 | if_initname(ifp, "lo", i); |
| 113 | ifp->if_mtu = LOMTU; |
| 114 | ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; |
| 115 | ifp->if_capabilities = IFCAP_HWCSUM; |
| 116 | ifp->if_hwassist = LO_CSUM_FEATURES; |
| 117 | ifp->if_capenable = ifp->if_capabilities; |
| 118 | ifp->if_ioctl = loioctl; |
| 119 | ifp->if_output = looutput; |
| 120 | ifp->if_type = IFT_LOOP; |
| 121 | ifq_set_maxlen(&ifp->if_snd, ifqmaxlen); |
| 122 | ifq_set_ready(&ifp->if_snd); |
| 123 | #ifdef ALTQ |
| 124 | ifp->if_start = lo_altqstart; |
| 125 | #endif |
| 126 | if_attach(ifp, NULL); |
| 127 | bpfattach(ifp, DLT_NULL, sizeof(u_int)); |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | static int |
| 132 | looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, |
| 133 | struct rtentry *rt) |
| 134 | { |
| 135 | M_ASSERTPKTHDR(m); |
| 136 | |
| 137 | if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { |
| 138 | m_freem(m); |
| 139 | return (rt->rt_flags & RTF_BLACKHOLE ? 0 : |
| 140 | rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); |
| 141 | } |
| 142 | |
| 143 | ifp->if_opackets++; |
| 144 | ifp->if_obytes += m->m_pkthdr.len; |
| 145 | #if 1 /* XXX */ |
| 146 | switch (dst->sa_family) { |
| 147 | case AF_INET: |
| 148 | case AF_INET6: |
| 149 | case AF_IPX: |
| 150 | case AF_NS: |
| 151 | break; |
| 152 | default: |
| 153 | kprintf("looutput: af=%d unexpected\n", dst->sa_family); |
| 154 | m_freem(m); |
| 155 | return (EAFNOSUPPORT); |
| 156 | } |
| 157 | #endif |
| 158 | |
| 159 | if (ifp->if_capenable & IFCAP_RXCSUM) { |
| 160 | int csum_flags = 0; |
| 161 | |
| 162 | if (m->m_pkthdr.csum_flags & CSUM_IP) |
| 163 | csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID); |
| 164 | if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) |
| 165 | csum_flags |= (CSUM_DATA_VALID | CSUM_PSEUDO_HDR); |
| 166 | |
| 167 | m->m_pkthdr.csum_flags |= csum_flags; |
| 168 | if (csum_flags & CSUM_DATA_VALID) |
| 169 | m->m_pkthdr.csum_data = 0xffff; |
| 170 | } |
| 171 | return (if_simloop(ifp, m, dst->sa_family, 0)); |
| 172 | } |
| 173 | |
| 174 | /* |
| 175 | * if_simloop() |
| 176 | * |
| 177 | * This function is to support software emulation of hardware loopback, |
| 178 | * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't |
| 179 | * hear their own broadcasts, we create a copy of the packet that we |
| 180 | * would normally receive via a hardware loopback. |
| 181 | * |
| 182 | * This function expects the packet to include the media header of length hlen. |
| 183 | */ |
| 184 | int |
| 185 | if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) |
| 186 | { |
| 187 | int isr; |
| 188 | |
| 189 | KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR")); |
| 190 | m->m_pkthdr.rcvif = ifp; |
| 191 | |
| 192 | /* BPF write needs to be handled specially */ |
| 193 | if (af == AF_UNSPEC) { |
| 194 | KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); |
| 195 | af = *(mtod(m, int *)); |
| 196 | m->m_len -= sizeof(int); |
| 197 | m->m_pkthdr.len -= sizeof(int); |
| 198 | m->m_data += sizeof(int); |
| 199 | } |
| 200 | |
| 201 | if (ifp->if_bpf) { |
| 202 | bpf_gettoken(); |
| 203 | |
| 204 | /* Re-check */ |
| 205 | if (ifp->if_bpf == NULL) |
| 206 | goto rel; |
| 207 | |
| 208 | if (ifp->if_bpf->bif_dlt == DLT_NULL) { |
| 209 | uint32_t bpf_af = (uint32_t)af; |
| 210 | bpf_ptap(ifp->if_bpf, m, &bpf_af, 4); |
| 211 | } else { |
| 212 | bpf_mtap(ifp->if_bpf, m); |
| 213 | } |
| 214 | rel: |
| 215 | bpf_reltoken(); |
| 216 | } |
| 217 | |
| 218 | /* Strip away media header */ |
| 219 | if (hlen > 0) |
| 220 | m_adj(m, hlen); |
| 221 | |
| 222 | #ifdef ALTQ |
| 223 | /* |
| 224 | * altq for loop is just for debugging. |
| 225 | * only used when called for loop interface (not for |
| 226 | * a simplex interface). |
| 227 | */ |
| 228 | if (ifq_is_enabled(&ifp->if_snd) && ifp->if_start == lo_altqstart) { |
| 229 | struct altq_pktattr pktattr; |
| 230 | int32_t *afp; |
| 231 | |
| 232 | /* |
| 233 | * if the queueing discipline needs packet classification, |
| 234 | * do it before prepending link headers. |
| 235 | */ |
| 236 | ifq_classify(&ifp->if_snd, m, af, &pktattr); |
| 237 | |
| 238 | M_PREPEND(m, sizeof(int32_t), MB_DONTWAIT); |
| 239 | if (m == NULL) |
| 240 | return(ENOBUFS); |
| 241 | afp = mtod(m, int32_t *); |
| 242 | *afp = (int32_t)af; |
| 243 | |
| 244 | return ifq_dispatch(ifp, m, &pktattr); |
| 245 | } |
| 246 | #endif /* ALTQ */ |
| 247 | |
| 248 | /* Deliver to upper layer protocol */ |
| 249 | switch (af) { |
| 250 | #ifdef INET |
| 251 | case AF_INET: |
| 252 | isr = NETISR_IP; |
| 253 | break; |
| 254 | #endif |
| 255 | #ifdef INET6 |
| 256 | case AF_INET6: |
| 257 | m->m_flags |= M_LOOP; |
| 258 | isr = NETISR_IPV6; |
| 259 | break; |
| 260 | #endif |
| 261 | #ifdef IPX |
| 262 | case AF_IPX: |
| 263 | isr = NETISR_IPX; |
| 264 | break; |
| 265 | #endif |
| 266 | default: |
| 267 | kprintf("if_simloop: can't handle af=%d\n", af); |
| 268 | m_freem(m); |
| 269 | return (EAFNOSUPPORT); |
| 270 | } |
| 271 | |
| 272 | ifp->if_ipackets++; |
| 273 | ifp->if_ibytes += m->m_pkthdr.len; |
| 274 | netisr_queue(isr, m); |
| 275 | return (0); |
| 276 | } |
| 277 | |
| 278 | #ifdef ALTQ |
| 279 | static void |
| 280 | lo_altqstart(struct ifnet *ifp, struct ifaltq_subque *ifsq) |
| 281 | { |
| 282 | struct mbuf *m; |
| 283 | int32_t af, *afp; |
| 284 | int isr; |
| 285 | |
| 286 | while (1) { |
| 287 | crit_enter(); |
| 288 | m = ifsq_dequeue(ifsq, NULL); |
| 289 | crit_exit(); |
| 290 | if (m == NULL) |
| 291 | return; |
| 292 | |
| 293 | afp = mtod(m, int32_t *); |
| 294 | af = *afp; |
| 295 | m_adj(m, sizeof(int32_t)); |
| 296 | |
| 297 | switch (af) { |
| 298 | #ifdef INET |
| 299 | case AF_INET: |
| 300 | isr = NETISR_IP; |
| 301 | break; |
| 302 | #endif |
| 303 | #ifdef INET6 |
| 304 | case AF_INET6: |
| 305 | m->m_flags |= M_LOOP; |
| 306 | isr = NETISR_IPV6; |
| 307 | break; |
| 308 | #endif |
| 309 | #ifdef IPX |
| 310 | case AF_IPX: |
| 311 | isr = NETISR_IPX; |
| 312 | break; |
| 313 | #endif |
| 314 | #ifdef ISO |
| 315 | case AF_ISO: |
| 316 | isr = NETISR_ISO; |
| 317 | break; |
| 318 | #endif |
| 319 | default: |
| 320 | kprintf("lo_altqstart: can't handle af%d\n", af); |
| 321 | m_freem(m); |
| 322 | return; |
| 323 | } |
| 324 | |
| 325 | ifp->if_ipackets++; |
| 326 | ifp->if_ibytes += m->m_pkthdr.len; |
| 327 | netisr_queue(isr, m); |
| 328 | } |
| 329 | } |
| 330 | #endif /* ALTQ */ |
| 331 | |
| 332 | /* ARGSUSED */ |
| 333 | static void |
| 334 | lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) |
| 335 | { |
| 336 | if (rt) { |
| 337 | rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ |
| 338 | /* |
| 339 | * For optimal performance, the send and receive buffers |
| 340 | * should be at least twice the MTU plus a little more for |
| 341 | * overhead. |
| 342 | */ |
| 343 | rt->rt_rmx.rmx_recvpipe = rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; |
| 344 | } |
| 345 | } |
| 346 | |
| 347 | /* |
| 348 | * Process an ioctl request. |
| 349 | */ |
| 350 | /* ARGSUSED */ |
| 351 | static int |
| 352 | loioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) |
| 353 | { |
| 354 | struct ifaddr *ifa; |
| 355 | struct ifreq *ifr = (struct ifreq *)data; |
| 356 | int error = 0, mask; |
| 357 | |
| 358 | switch (cmd) { |
| 359 | case SIOCSIFADDR: |
| 360 | ifp->if_flags |= IFF_UP | IFF_RUNNING; |
| 361 | ifa = (struct ifaddr *)data; |
| 362 | ifa->ifa_rtrequest = lortrequest; |
| 363 | /* |
| 364 | * Everything else is done at a higher level. |
| 365 | */ |
| 366 | break; |
| 367 | |
| 368 | case SIOCADDMULTI: |
| 369 | case SIOCDELMULTI: |
| 370 | if (ifr == NULL) { |
| 371 | error = EAFNOSUPPORT; /* XXX */ |
| 372 | break; |
| 373 | } |
| 374 | switch (ifr->ifr_addr.sa_family) { |
| 375 | |
| 376 | #ifdef INET |
| 377 | case AF_INET: |
| 378 | break; |
| 379 | #endif |
| 380 | #ifdef INET6 |
| 381 | case AF_INET6: |
| 382 | break; |
| 383 | #endif |
| 384 | |
| 385 | default: |
| 386 | error = EAFNOSUPPORT; |
| 387 | break; |
| 388 | } |
| 389 | break; |
| 390 | |
| 391 | case SIOCSIFMTU: |
| 392 | ifp->if_mtu = ifr->ifr_mtu; |
| 393 | break; |
| 394 | |
| 395 | case SIOCSIFFLAGS: |
| 396 | break; |
| 397 | |
| 398 | case SIOCSIFCAP: |
| 399 | mask = (ifr->ifr_reqcap ^ ifp->if_capenable) & IFCAP_HWCSUM; |
| 400 | if (mask) { |
| 401 | ifp->if_capenable ^= mask; |
| 402 | if (IFCAP_TXCSUM & ifp->if_capenable) |
| 403 | ifp->if_hwassist = LO_CSUM_FEATURES; |
| 404 | else |
| 405 | ifp->if_hwassist = 0; |
| 406 | } |
| 407 | break; |
| 408 | |
| 409 | default: |
| 410 | error = EINVAL; |
| 411 | } |
| 412 | return (error); |
| 413 | } |