1 /* $NetBSD: if_virt.c,v 1.27 2012/09/14 16:29:22 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 2008 Antti Kantee. All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 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 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __KERNEL_RCSID(0, "$NetBSD: if_virt.c,v 1.27 2012/09/14 16:29:22 pooka Exp $"); 30 31 #include <sys/param.h> 32 #include <sys/condvar.h> 33 #include <sys/fcntl.h> 34 #include <sys/kernel.h> 35 #include <sys/kmem.h> 36 #include <sys/kthread.h> 37 #include <sys/mutex.h> 38 #include <sys/poll.h> 39 #include <sys/sockio.h> 40 #include <sys/socketvar.h> 41 #include <sys/cprng.h> 42 43 #include <net/bpf.h> 44 #include <net/if.h> 45 #include <net/if_ether.h> 46 #include <net/if_tap.h> 47 48 #include <netinet/in.h> 49 #include <netinet/in_var.h> 50 51 #include <rump/rump.h> 52 #include <rump/rumpuser.h> 53 54 #include "rump_private.h" 55 #include "rump_net_private.h" 56 57 /* 58 * Virtual interface for userspace purposes. Uses tap(4) to 59 * interface with the kernel and just simply shovels data 60 * to/from /dev/tap. 61 */ 62 63 #define VIRTIF_BASE "virt" 64 65 static int virtif_init(struct ifnet *); 66 static int virtif_ioctl(struct ifnet *, u_long, void *); 67 static void virtif_start(struct ifnet *); 68 static void virtif_stop(struct ifnet *, int); 69 70 struct virtif_sc { 71 struct ethercom sc_ec; 72 int sc_tapfd; 73 bool sc_dying; 74 struct lwp *sc_l_snd, *sc_l_rcv; 75 kmutex_t sc_mtx; 76 kcondvar_t sc_cv; 77 }; 78 79 static void virtif_receiver(void *); 80 static void virtif_sender(void *); 81 static int virtif_clone(struct if_clone *, int); 82 static int virtif_unclone(struct ifnet *); 83 84 struct if_clone virtif_cloner = 85 IF_CLONE_INITIALIZER(VIRTIF_BASE, virtif_clone, virtif_unclone); 86 87 int 88 rump_virtif_create(int num) 89 { 90 struct virtif_sc *sc; 91 struct ifnet *ifp; 92 uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0x0a, 0x00, 0x0b, 0x0e, 0x01 }; 93 char tapdev[16]; 94 int fd, error = 0; 95 96 if (num >= 0x100) 97 return E2BIG; 98 99 snprintf(tapdev, sizeof(tapdev), "/dev/tap%d", num); 100 fd = rumpuser_open(tapdev, RUMPUSER_OPEN_RDWR, &error); 101 if (fd == -1) { 102 printf("virtif_create: can't open /dev/tap%d: %d\n", 103 num, error); 104 return error; 105 } 106 enaddr[2] = cprng_fast32() & 0xff; 107 enaddr[5] = num; 108 109 sc = kmem_zalloc(sizeof(*sc), KM_SLEEP); 110 sc->sc_dying = false; 111 sc->sc_tapfd = fd; 112 113 mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_NONE); 114 cv_init(&sc->sc_cv, "virtsnd"); 115 ifp = &sc->sc_ec.ec_if; 116 sprintf(ifp->if_xname, "%s%d", VIRTIF_BASE, num); 117 ifp->if_softc = sc; 118 119 if (rump_threads) { 120 if ((error = kthread_create(PRI_NONE, KTHREAD_MUSTJOIN, NULL, 121 virtif_receiver, ifp, &sc->sc_l_rcv, "virtifr")) != 0) 122 goto out; 123 124 if ((error = kthread_create(PRI_NONE, 125 KTHREAD_MUSTJOIN | KTHREAD_MPSAFE, NULL, 126 virtif_sender, ifp, &sc->sc_l_snd, "virtifs")) != 0) 127 goto out; 128 } else { 129 printf("WARNING: threads not enabled, receive NOT working\n"); 130 } 131 132 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; 133 ifp->if_init = virtif_init; 134 ifp->if_ioctl = virtif_ioctl; 135 ifp->if_start = virtif_start; 136 ifp->if_stop = virtif_stop; 137 IFQ_SET_READY(&ifp->if_snd); 138 139 if_attach(ifp); 140 ether_ifattach(ifp, enaddr); 141 142 out: 143 if (error) { 144 virtif_unclone(ifp); 145 } 146 147 return error; 148 } 149 150 static int 151 virtif_clone(struct if_clone *ifc, int unit) 152 { 153 154 return rump_virtif_create(unit); 155 } 156 157 static int 158 virtif_unclone(struct ifnet *ifp) 159 { 160 struct virtif_sc *sc = ifp->if_softc; 161 162 mutex_enter(&sc->sc_mtx); 163 if (sc->sc_dying) { 164 mutex_exit(&sc->sc_mtx); 165 return EINPROGRESS; 166 } 167 sc->sc_dying = true; 168 cv_broadcast(&sc->sc_cv); 169 mutex_exit(&sc->sc_mtx); 170 171 virtif_stop(ifp, 1); 172 if_down(ifp); 173 174 if (sc->sc_l_snd) { 175 kthread_join(sc->sc_l_snd); 176 sc->sc_l_snd = NULL; 177 } 178 if (sc->sc_l_rcv) { 179 kthread_join(sc->sc_l_rcv); 180 sc->sc_l_rcv = NULL; 181 } 182 183 rumpuser_close(sc->sc_tapfd, NULL); 184 185 mutex_destroy(&sc->sc_mtx); 186 cv_destroy(&sc->sc_cv); 187 kmem_free(sc, sizeof(*sc)); 188 189 ether_ifdetach(ifp); 190 if_detach(ifp); 191 192 return 0; 193 } 194 195 static int 196 virtif_init(struct ifnet *ifp) 197 { 198 struct virtif_sc *sc = ifp->if_softc; 199 200 ifp->if_flags |= IFF_RUNNING; 201 202 mutex_enter(&sc->sc_mtx); 203 cv_broadcast(&sc->sc_cv); 204 mutex_exit(&sc->sc_mtx); 205 206 return 0; 207 } 208 209 static int 210 virtif_ioctl(struct ifnet *ifp, u_long cmd, void *data) 211 { 212 int s, rv; 213 214 s = splnet(); 215 rv = ether_ioctl(ifp, cmd, data); 216 if (rv == ENETRESET) 217 rv = 0; 218 splx(s); 219 220 return rv; 221 } 222 223 /* just send everything in-context */ 224 static void 225 virtif_start(struct ifnet *ifp) 226 { 227 struct virtif_sc *sc = ifp->if_softc; 228 229 mutex_enter(&sc->sc_mtx); 230 ifp->if_flags |= IFF_OACTIVE; 231 cv_broadcast(&sc->sc_cv); 232 mutex_exit(&sc->sc_mtx); 233 } 234 235 static void 236 virtif_stop(struct ifnet *ifp, int disable) 237 { 238 struct virtif_sc *sc = ifp->if_softc; 239 240 ifp->if_flags &= ~IFF_RUNNING; 241 242 mutex_enter(&sc->sc_mtx); 243 cv_broadcast(&sc->sc_cv); 244 mutex_exit(&sc->sc_mtx); 245 } 246 247 #define POLLTIMO_MS 1 248 static void 249 virtif_receiver(void *arg) 250 { 251 struct ifnet *ifp = arg; 252 struct virtif_sc *sc = ifp->if_softc; 253 struct mbuf *m; 254 size_t plen = ETHER_MAX_LEN_JUMBO+1; 255 struct pollfd pfd; 256 ssize_t n; 257 int error, rv; 258 259 pfd.fd = sc->sc_tapfd; 260 pfd.events = POLLIN; 261 262 for (;;) { 263 m = m_gethdr(M_WAIT, MT_DATA); 264 MEXTMALLOC(m, plen, M_WAIT); 265 266 again: 267 /* poll, but periodically check if we should die */ 268 rv = rumpuser_poll(&pfd, 1, POLLTIMO_MS, &error); 269 if (sc->sc_dying) { 270 m_freem(m); 271 break; 272 } 273 if (rv == 0) 274 goto again; 275 276 n = rumpuser_read(sc->sc_tapfd, mtod(m, void *), plen, &error); 277 KASSERT(n < ETHER_MAX_LEN_JUMBO); 278 if (__predict_false(n < 0)) { 279 if (n == -1 && error == EAGAIN) { 280 goto again; 281 } 282 283 printf("%s: read from /dev/tap failed. host is down?\n", 284 ifp->if_xname); 285 mutex_enter(&sc->sc_mtx); 286 /* could check if need go, done soon anyway */ 287 cv_timedwait(&sc->sc_cv, &sc->sc_mtx, hz); 288 mutex_exit(&sc->sc_mtx); 289 goto again; 290 } 291 292 /* tap sometimes returns EOF. don't sweat it and plow on */ 293 if (__predict_false(n == 0)) 294 goto again; 295 296 /* discard if we're not up */ 297 if ((ifp->if_flags & IFF_RUNNING) == 0) 298 goto again; 299 300 m->m_len = m->m_pkthdr.len = n; 301 m->m_pkthdr.rcvif = ifp; 302 bpf_mtap(ifp, m); 303 ether_input(ifp, m); 304 } 305 306 kthread_exit(0); 307 } 308 309 /* lazy bum stetson-harrison magic value */ 310 #define LB_SH 32 311 static void 312 virtif_sender(void *arg) 313 { 314 struct ifnet *ifp = arg; 315 struct virtif_sc *sc = ifp->if_softc; 316 struct mbuf *m, *m0; 317 struct rumpuser_iovec io[LB_SH]; 318 int i, error; 319 320 mutex_enter(&sc->sc_mtx); 321 KERNEL_LOCK(1, NULL); 322 while (!sc->sc_dying) { 323 if (!(ifp->if_flags & IFF_RUNNING)) { 324 cv_wait(&sc->sc_cv, &sc->sc_mtx); 325 continue; 326 } 327 IF_DEQUEUE(&ifp->if_snd, m0); 328 if (!m0) { 329 ifp->if_flags &= ~IFF_OACTIVE; 330 cv_wait(&sc->sc_cv, &sc->sc_mtx); 331 continue; 332 } 333 mutex_exit(&sc->sc_mtx); 334 335 m = m0; 336 for (i = 0; i < LB_SH && m; i++) { 337 io[i].iov_base = mtod(m, void *); 338 io[i].iov_len = m->m_len; 339 m = m->m_next; 340 } 341 if (i == LB_SH) 342 panic("lazy bum"); 343 bpf_mtap(ifp, m0); 344 KERNEL_UNLOCK_LAST(curlwp); 345 346 rumpuser_writev(sc->sc_tapfd, io, i, &error); 347 348 KERNEL_LOCK(1, NULL); 349 m_freem(m0); 350 mutex_enter(&sc->sc_mtx); 351 } 352 KERNEL_UNLOCK_LAST(curlwp); 353 354 mutex_exit(&sc->sc_mtx); 355 356 kthread_exit(0); 357 } 358 359 /* 360 * dummyif is a nada-interface. 361 * As it requires nothing external, it can be used for testing 362 * interface configuration. 363 */ 364 static int dummyif_init(struct ifnet *); 365 static void dummyif_start(struct ifnet *); 366 367 void 368 rump_dummyif_create() 369 { 370 struct ifnet *ifp; 371 struct ethercom *ec; 372 uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0x0a, 0x00, 0x0b, 0x0e, 0x01 }; 373 374 enaddr[2] = cprng_fast32() & 0xff; 375 enaddr[5] = cprng_fast32() & 0xff; 376 377 ec = kmem_zalloc(sizeof(*ec), KM_SLEEP); 378 379 ifp = &ec->ec_if; 380 strlcpy(ifp->if_xname, "dummy0", sizeof(ifp->if_xname)); 381 ifp->if_softc = ifp; 382 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; 383 ifp->if_init = dummyif_init; 384 ifp->if_ioctl = virtif_ioctl; 385 ifp->if_start = dummyif_start; 386 387 if_attach(ifp); 388 ether_ifattach(ifp, enaddr); 389 } 390 391 static int 392 dummyif_init(struct ifnet *ifp) 393 { 394 395 ifp->if_flags |= IFF_RUNNING; 396 return 0; 397 } 398 399 static void 400 dummyif_start(struct ifnet *ifp) 401 { 402 403 } 404