1 /* 2 * QEMU System Emulator 3 * 4 * Copyright (c) 2003-2008 Fabrice Bellard 5 * Copyright (c) 2009 Red Hat, Inc. 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a copy 8 * of this software and associated documentation files (the "Software"), to deal 9 * in the Software without restriction, including without limitation the rights 10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11 * copies of the Software, and to permit persons to whom the Software is 12 * furnished to do so, subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included in 15 * all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 23 * THE SOFTWARE. 24 */ 25 26 #include "net/tap.h" 27 28 #include "config-host.h" 29 30 #include <signal.h> 31 #include <sys/ioctl.h> 32 #include <sys/stat.h> 33 #include <sys/wait.h> 34 #include <sys/socket.h> 35 #include <net/if.h> 36 37 #include "net.h" 38 #include "sysemu.h" 39 #include "qemu-char.h" 40 #include "qemu-common.h" 41 #include "qemu-error.h" 42 43 #include "net/tap-linux.h" 44 45 #include "hw/vhost_net.h" 46 47 /* Maximum GSO packet size (64k) plus plenty of room for 48 * the ethernet and virtio_net headers 49 */ 50 #define TAP_BUFSIZE (4096 + 65536) 51 52 typedef struct TAPState { 53 VLANClientState nc; 54 int fd; 55 char down_script[1024]; 56 char down_script_arg[128]; 57 uint8_t buf[TAP_BUFSIZE]; 58 unsigned int read_poll : 1; 59 unsigned int write_poll : 1; 60 unsigned int has_vnet_hdr : 1; 61 unsigned int using_vnet_hdr : 1; 62 unsigned int has_ufo: 1; 63 VHostNetState *vhost_net; 64 } TAPState; 65 66 static int launch_script(const char *setup_script, const char *ifname, int fd); 67 68 static int tap_can_send(void *opaque); 69 static void tap_send(void *opaque); 70 static void tap_writable(void *opaque); 71 72 static void tap_update_fd_handler(TAPState *s) 73 { 74 qemu_set_fd_handler2(s->fd, 75 s->read_poll ? tap_can_send : NULL, 76 s->read_poll ? tap_send : NULL, 77 s->write_poll ? tap_writable : NULL, 78 s); 79 } 80 81 static void tap_read_poll(TAPState *s, int enable) 82 { 83 s->read_poll = !!enable; 84 tap_update_fd_handler(s); 85 } 86 87 static void tap_write_poll(TAPState *s, int enable) 88 { 89 s->write_poll = !!enable; 90 tap_update_fd_handler(s); 91 } 92 93 static void tap_writable(void *opaque) 94 { 95 TAPState *s = opaque; 96 97 tap_write_poll(s, 0); 98 99 qemu_flush_queued_packets(&s->nc); 100 } 101 102 static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt) 103 { 104 ssize_t len; 105 106 do { 107 len = writev(s->fd, iov, iovcnt); 108 } while (len == -1 && errno == EINTR); 109 110 if (len == -1 && errno == EAGAIN) { 111 tap_write_poll(s, 1); 112 return 0; 113 } 114 115 return len; 116 } 117 118 static ssize_t tap_receive_iov(VLANClientState *nc, const struct iovec *iov, 119 int iovcnt) 120 { 121 TAPState *s = DO_UPCAST(TAPState, nc, nc); 122 const struct iovec *iovp = iov; 123 struct iovec iov_copy[iovcnt + 1]; 124 struct virtio_net_hdr hdr = { 0, }; 125 126 if (s->has_vnet_hdr && !s->using_vnet_hdr) { 127 iov_copy[0].iov_base = &hdr; 128 iov_copy[0].iov_len = sizeof(hdr); 129 memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov)); 130 iovp = iov_copy; 131 iovcnt++; 132 } 133 134 return tap_write_packet(s, iovp, iovcnt); 135 } 136 137 static ssize_t tap_receive_raw(VLANClientState *nc, const uint8_t *buf, size_t size) 138 { 139 TAPState *s = DO_UPCAST(TAPState, nc, nc); 140 struct iovec iov[2]; 141 int iovcnt = 0; 142 struct virtio_net_hdr hdr = { 0, }; 143 144 if (s->has_vnet_hdr) { 145 iov[iovcnt].iov_base = &hdr; 146 iov[iovcnt].iov_len = sizeof(hdr); 147 iovcnt++; 148 } 149 150 iov[iovcnt].iov_base = (char *)buf; 151 iov[iovcnt].iov_len = size; 152 iovcnt++; 153 154 return tap_write_packet(s, iov, iovcnt); 155 } 156 157 static ssize_t tap_receive(VLANClientState *nc, const uint8_t *buf, size_t size) 158 { 159 TAPState *s = DO_UPCAST(TAPState, nc, nc); 160 struct iovec iov[1]; 161 162 if (s->has_vnet_hdr && !s->using_vnet_hdr) { 163 return tap_receive_raw(nc, buf, size); 164 } 165 166 iov[0].iov_base = (char *)buf; 167 iov[0].iov_len = size; 168 169 return tap_write_packet(s, iov, 1); 170 } 171 172 static int tap_can_send(void *opaque) 173 { 174 TAPState *s = opaque; 175 176 return qemu_can_send_packet(&s->nc); 177 } 178 179 #ifndef __sun__ 180 ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen) 181 { 182 return read(tapfd, buf, maxlen); 183 } 184 #endif 185 186 static void tap_send_completed(VLANClientState *nc, ssize_t len) 187 { 188 TAPState *s = DO_UPCAST(TAPState, nc, nc); 189 tap_read_poll(s, 1); 190 } 191 192 static void tap_send(void *opaque) 193 { 194 TAPState *s = opaque; 195 int size; 196 197 do { 198 uint8_t *buf = s->buf; 199 200 size = tap_read_packet(s->fd, s->buf, sizeof(s->buf)); 201 if (size <= 0) { 202 break; 203 } 204 205 if (s->has_vnet_hdr && !s->using_vnet_hdr) { 206 buf += sizeof(struct virtio_net_hdr); 207 size -= sizeof(struct virtio_net_hdr); 208 } 209 210 size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed); 211 if (size == 0) { 212 tap_read_poll(s, 0); 213 } 214 } while (size > 0 && qemu_can_send_packet(&s->nc)); 215 } 216 217 int tap_has_ufo(VLANClientState *nc) 218 { 219 TAPState *s = DO_UPCAST(TAPState, nc, nc); 220 221 assert(nc->info->type == NET_CLIENT_TYPE_TAP); 222 223 return s->has_ufo; 224 } 225 226 int tap_has_vnet_hdr(VLANClientState *nc) 227 { 228 TAPState *s = DO_UPCAST(TAPState, nc, nc); 229 230 assert(nc->info->type == NET_CLIENT_TYPE_TAP); 231 232 return s->has_vnet_hdr; 233 } 234 235 void tap_using_vnet_hdr(VLANClientState *nc, int using_vnet_hdr) 236 { 237 TAPState *s = DO_UPCAST(TAPState, nc, nc); 238 239 using_vnet_hdr = using_vnet_hdr != 0; 240 241 assert(nc->info->type == NET_CLIENT_TYPE_TAP); 242 assert(s->has_vnet_hdr == using_vnet_hdr); 243 244 s->using_vnet_hdr = using_vnet_hdr; 245 } 246 247 void tap_set_offload(VLANClientState *nc, int csum, int tso4, 248 int tso6, int ecn, int ufo) 249 { 250 TAPState *s = DO_UPCAST(TAPState, nc, nc); 251 252 return tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo); 253 } 254 255 static void tap_cleanup(VLANClientState *nc) 256 { 257 TAPState *s = DO_UPCAST(TAPState, nc, nc); 258 259 if (s->vhost_net) { 260 vhost_net_cleanup(s->vhost_net); 261 } 262 263 qemu_purge_queued_packets(nc); 264 265 if (s->down_script[0]) 266 launch_script(s->down_script, s->down_script_arg, s->fd); 267 268 tap_read_poll(s, 0); 269 tap_write_poll(s, 0); 270 close(s->fd); 271 } 272 273 static void tap_poll(VLANClientState *nc, bool enable) 274 { 275 TAPState *s = DO_UPCAST(TAPState, nc, nc); 276 tap_read_poll(s, enable); 277 tap_write_poll(s, enable); 278 } 279 280 int tap_get_fd(VLANClientState *nc) 281 { 282 TAPState *s = DO_UPCAST(TAPState, nc, nc); 283 assert(nc->info->type == NET_CLIENT_TYPE_TAP); 284 return s->fd; 285 } 286 287 /* fd support */ 288 289 static NetClientInfo net_tap_info = { 290 .type = NET_CLIENT_TYPE_TAP, 291 .size = sizeof(TAPState), 292 .receive = tap_receive, 293 .receive_raw = tap_receive_raw, 294 .receive_iov = tap_receive_iov, 295 .poll = tap_poll, 296 .cleanup = tap_cleanup, 297 }; 298 299 static TAPState *net_tap_fd_init(VLANState *vlan, 300 const char *model, 301 const char *name, 302 int fd, 303 int vnet_hdr) 304 { 305 VLANClientState *nc; 306 TAPState *s; 307 308 nc = qemu_new_net_client(&net_tap_info, vlan, NULL, model, name); 309 310 s = DO_UPCAST(TAPState, nc, nc); 311 312 s->fd = fd; 313 s->has_vnet_hdr = vnet_hdr != 0; 314 s->using_vnet_hdr = 0; 315 s->has_ufo = tap_probe_has_ufo(s->fd); 316 tap_set_offload(&s->nc, 0, 0, 0, 0, 0); 317 tap_read_poll(s, 1); 318 s->vhost_net = NULL; 319 return s; 320 } 321 322 static int launch_script(const char *setup_script, const char *ifname, int fd) 323 { 324 sigset_t oldmask, mask; 325 int pid, status; 326 char *args[3]; 327 char **parg; 328 329 sigemptyset(&mask); 330 sigaddset(&mask, SIGCHLD); 331 sigprocmask(SIG_BLOCK, &mask, &oldmask); 332 333 /* try to launch network script */ 334 pid = fork(); 335 if (pid == 0) { 336 int open_max = sysconf(_SC_OPEN_MAX), i; 337 338 for (i = 0; i < open_max; i++) { 339 if (i != STDIN_FILENO && 340 i != STDOUT_FILENO && 341 i != STDERR_FILENO && 342 i != fd) { 343 close(i); 344 } 345 } 346 parg = args; 347 *parg++ = (char *)setup_script; 348 *parg++ = (char *)ifname; 349 *parg = NULL; 350 execv(setup_script, args); 351 _exit(1); 352 } else if (pid > 0) { 353 while (waitpid(pid, &status, 0) != pid) { 354 /* loop */ 355 } 356 sigprocmask(SIG_SETMASK, &oldmask, NULL); 357 358 if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { 359 return 0; 360 } 361 } 362 fprintf(stderr, "%s: could not launch network script\n", setup_script); 363 return -1; 364 } 365 366 static int net_tap_init(QemuOpts *opts, int *vnet_hdr) 367 { 368 int fd, vnet_hdr_required; 369 char ifname[128] = {0,}; 370 const char *setup_script; 371 372 if (qemu_opt_get(opts, "ifname")) { 373 pstrcpy(ifname, sizeof(ifname), qemu_opt_get(opts, "ifname")); 374 } 375 376 *vnet_hdr = qemu_opt_get_bool(opts, "vnet_hdr", 1); 377 if (qemu_opt_get(opts, "vnet_hdr")) { 378 vnet_hdr_required = *vnet_hdr; 379 } else { 380 vnet_hdr_required = 0; 381 } 382 383 TFR(fd = tap_open(ifname, sizeof(ifname), vnet_hdr, vnet_hdr_required)); 384 if (fd < 0) { 385 return -1; 386 } 387 388 setup_script = qemu_opt_get(opts, "script"); 389 if (setup_script && 390 setup_script[0] != '\0' && 391 strcmp(setup_script, "no") != 0 && 392 launch_script(setup_script, ifname, fd)) { 393 close(fd); 394 return -1; 395 } 396 397 qemu_opt_set(opts, "ifname", ifname); 398 399 return fd; 400 } 401 402 int net_init_tap(QemuOpts *opts, Monitor *mon, const char *name, VLANState *vlan) 403 { 404 TAPState *s; 405 int fd, vnet_hdr = 0; 406 407 if (qemu_opt_get(opts, "fd")) { 408 if (qemu_opt_get(opts, "ifname") || 409 qemu_opt_get(opts, "script") || 410 qemu_opt_get(opts, "downscript") || 411 qemu_opt_get(opts, "vnet_hdr")) { 412 error_report("ifname=, script=, downscript= and vnet_hdr= is invalid with fd="); 413 return -1; 414 } 415 416 fd = net_handle_fd_param(mon, qemu_opt_get(opts, "fd")); 417 if (fd == -1) { 418 return -1; 419 } 420 421 fcntl(fd, F_SETFL, O_NONBLOCK); 422 423 vnet_hdr = tap_probe_vnet_hdr(fd); 424 } else { 425 if (!qemu_opt_get(opts, "script")) { 426 qemu_opt_set(opts, "script", DEFAULT_NETWORK_SCRIPT); 427 } 428 429 if (!qemu_opt_get(opts, "downscript")) { 430 qemu_opt_set(opts, "downscript", DEFAULT_NETWORK_DOWN_SCRIPT); 431 } 432 433 fd = net_tap_init(opts, &vnet_hdr); 434 if (fd == -1) { 435 return -1; 436 } 437 } 438 439 s = net_tap_fd_init(vlan, "tap", name, fd, vnet_hdr); 440 if (!s) { 441 close(fd); 442 return -1; 443 } 444 445 if (tap_set_sndbuf(s->fd, opts) < 0) { 446 return -1; 447 } 448 449 if (qemu_opt_get(opts, "fd")) { 450 snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd); 451 } else { 452 const char *ifname, *script, *downscript; 453 454 ifname = qemu_opt_get(opts, "ifname"); 455 script = qemu_opt_get(opts, "script"); 456 downscript = qemu_opt_get(opts, "downscript"); 457 458 snprintf(s->nc.info_str, sizeof(s->nc.info_str), 459 "ifname=%s,script=%s,downscript=%s", 460 ifname, script, downscript); 461 462 if (strcmp(downscript, "no") != 0) { 463 snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); 464 snprintf(s->down_script_arg, sizeof(s->down_script_arg), "%s", ifname); 465 } 466 } 467 468 if (qemu_opt_get_bool(opts, "vhost", !!qemu_opt_get(opts, "vhostfd"))) { 469 int vhostfd, r; 470 if (qemu_opt_get(opts, "vhostfd")) { 471 r = net_handle_fd_param(mon, qemu_opt_get(opts, "vhostfd")); 472 if (r == -1) { 473 return -1; 474 } 475 vhostfd = r; 476 } else { 477 vhostfd = -1; 478 } 479 s->vhost_net = vhost_net_init(&s->nc, vhostfd); 480 if (!s->vhost_net) { 481 error_report("vhost-net requested but could not be initialized"); 482 return -1; 483 } 484 } else if (qemu_opt_get(opts, "vhostfd")) { 485 error_report("vhostfd= is not valid without vhost"); 486 return -1; 487 } 488 489 return 0; 490 } 491 492 VHostNetState *tap_get_vhost_net(VLANClientState *nc) 493 { 494 TAPState *s = DO_UPCAST(TAPState, nc, nc); 495 assert(nc->info->type == NET_CLIENT_TYPE_TAP); 496 return s->vhost_net; 497 } 498