| 1 | /* |
| 2 | * QEMU monitor file descriptor passing |
| 3 | * |
| 4 | * Copyright (c) 2003-2004 Fabrice Bellard |
| 5 | * |
| 6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 7 | * of this software and associated documentation files (the "Software"), to deal |
| 8 | * in the Software without restriction, including without limitation the rights |
| 9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 10 | * copies of the Software, and to permit persons to whom the Software is |
| 11 | * furnished to do so, subject to the following conditions: |
| 12 | * |
| 13 | * The above copyright notice and this permission notice shall be included in |
| 14 | * all copies or substantial portions of the Software. |
| 15 | * |
| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 22 | * THE SOFTWARE. |
| 23 | */ |
| 24 | |
| 25 | #include "qemu/osdep.h" |
| 26 | #include "monitor-internal.h" |
| 27 | #include "qapi/error.h" |
| 28 | #include "qapi/qapi-commands-misc.h" |
| 29 | #include "qapi/qmp/qerror.h" |
| 30 | #include "qemu/ctype.h" |
| 31 | #include "qemu/cutils.h" |
| 32 | #include "qemu/lockable.h" |
| 33 | #include "system/runstate.h" |
| 34 | |
| 35 | /* file descriptors passed via SCM_RIGHTS */ |
| 36 | typedef struct mon_fd_t mon_fd_t; |
| 37 | struct mon_fd_t { |
| 38 | char *name; |
| 39 | int fd; |
| 40 | QLIST_ENTRY(mon_fd_t) next; |
| 41 | }; |
| 42 | |
| 43 | /* file descriptor associated with a file descriptor set */ |
| 44 | typedef struct MonFdsetFd MonFdsetFd; |
| 45 | struct MonFdsetFd { |
| 46 | int fd; |
| 47 | char *opaque; |
| 48 | QLIST_ENTRY(MonFdsetFd) next; |
| 49 | }; |
| 50 | |
| 51 | /* file descriptor set containing fds passed via SCM_RIGHTS */ |
| 52 | typedef struct MonFdset MonFdset; |
| 53 | struct MonFdset { |
| 54 | int64_t id; |
| 55 | QLIST_HEAD(, MonFdsetFd) fds; |
| 56 | QLIST_HEAD(, MonFdsetFd) dup_fds; |
| 57 | QLIST_ENTRY(MonFdset) next; |
| 58 | }; |
| 59 | |
| 60 | /* Protects mon_fdsets */ |
| 61 | static QemuMutex mon_fdsets_lock; |
| 62 | static QLIST_HEAD(, MonFdset) mon_fdsets; |
| 63 | |
| 64 | static bool monitor_add_fd(Monitor *mon, int fd, const char *fdname, Error **errp) |
| 65 | { |
| 66 | mon_fd_t *monfd; |
| 67 | |
| 68 | if (qemu_isdigit(fdname[0])) { |
| 69 | close(fd); |
| 70 | error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "fdname", |
| 71 | "a name not starting with a digit"); |
| 72 | return false; |
| 73 | } |
| 74 | |
| 75 | /* See close() call below. */ |
| 76 | qemu_mutex_lock(&mon->mon_lock); |
| 77 | QLIST_FOREACH(monfd, &mon->fds, next) { |
| 78 | int tmp_fd; |
| 79 | |
| 80 | if (strcmp(monfd->name, fdname) != 0) { |
| 81 | continue; |
| 82 | } |
| 83 | |
| 84 | tmp_fd = monfd->fd; |
| 85 | monfd->fd = fd; |
| 86 | qemu_mutex_unlock(&mon->mon_lock); |
| 87 | /* Make sure close() is outside critical section */ |
| 88 | close(tmp_fd); |
| 89 | return true; |
| 90 | } |
| 91 | |
| 92 | monfd = g_new0(mon_fd_t, 1); |
| 93 | monfd->name = g_strdup(fdname); |
| 94 | monfd->fd = fd; |
| 95 | |
| 96 | QLIST_INSERT_HEAD(&mon->fds, monfd, next); |
| 97 | qemu_mutex_unlock(&mon->mon_lock); |
| 98 | return true; |
| 99 | } |
| 100 | |
| 101 | #ifdef CONFIG_POSIX |
| 102 | void qmp_getfd(const char *fdname, Error **errp) |
| 103 | { |
| 104 | Monitor *cur_mon = monitor_cur(); |
| 105 | int fd; |
| 106 | |
| 107 | fd = qemu_chr_fe_get_msgfd(&cur_mon->chr); |
| 108 | if (fd == -1) { |
| 109 | error_setg(errp, "No file descriptor supplied via SCM_RIGHTS"); |
| 110 | return; |
| 111 | } |
| 112 | |
| 113 | monitor_add_fd(cur_mon, fd, fdname, errp); |
| 114 | } |
| 115 | #endif |
| 116 | |
| 117 | void qmp_closefd(const char *fdname, Error **errp) |
| 118 | { |
| 119 | Monitor *cur_mon = monitor_cur(); |
| 120 | mon_fd_t *monfd; |
| 121 | int tmp_fd; |
| 122 | |
| 123 | qemu_mutex_lock(&cur_mon->mon_lock); |
| 124 | QLIST_FOREACH(monfd, &cur_mon->fds, next) { |
| 125 | if (strcmp(monfd->name, fdname) != 0) { |
| 126 | continue; |
| 127 | } |
| 128 | |
| 129 | QLIST_REMOVE(monfd, next); |
| 130 | tmp_fd = monfd->fd; |
| 131 | g_free(monfd->name); |
| 132 | g_free(monfd); |
| 133 | qemu_mutex_unlock(&cur_mon->mon_lock); |
| 134 | /* Make sure close() is outside critical section */ |
| 135 | close(tmp_fd); |
| 136 | return; |
| 137 | } |
| 138 | |
| 139 | qemu_mutex_unlock(&cur_mon->mon_lock); |
| 140 | error_setg(errp, "File descriptor named '%s' not found", fdname); |
| 141 | } |
| 142 | |
| 143 | int monitor_get_fd(Monitor *mon, const char *fdname, Error **errp) |
| 144 | { |
| 145 | mon_fd_t *monfd; |
| 146 | |
| 147 | QEMU_LOCK_GUARD(&mon->mon_lock); |
| 148 | QLIST_FOREACH(monfd, &mon->fds, next) { |
| 149 | int fd; |
| 150 | |
| 151 | if (strcmp(monfd->name, fdname) != 0) { |
| 152 | continue; |
| 153 | } |
| 154 | |
| 155 | fd = monfd->fd; |
| 156 | assert(fd >= 0); |
| 157 | |
| 158 | /* caller takes ownership of fd */ |
| 159 | QLIST_REMOVE(monfd, next); |
| 160 | g_free(monfd->name); |
| 161 | g_free(monfd); |
| 162 | |
| 163 | return fd; |
| 164 | } |
| 165 | |
| 166 | error_setg(errp, "File descriptor named '%s' has not been found", fdname); |
| 167 | return -1; |
| 168 | } |
| 169 | |
| 170 | static void monitor_fdset_free(MonFdset *mon_fdset) |
| 171 | { |
| 172 | QLIST_REMOVE(mon_fdset, next); |
| 173 | g_free(mon_fdset); |
| 174 | } |
| 175 | |
| 176 | static void monitor_fdset_free_if_empty(MonFdset *mon_fdset) |
| 177 | { |
| 178 | /* |
| 179 | * Only remove an empty fdset. The fds are owned by the user and |
| 180 | * should have been removed with qmp_remove_fd(). The dup_fds are |
| 181 | * owned by QEMU and should have been removed with qemu_close(). |
| 182 | */ |
| 183 | if (QLIST_EMPTY(&mon_fdset->fds) && QLIST_EMPTY(&mon_fdset->dup_fds)) { |
| 184 | monitor_fdset_free(mon_fdset); |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | static void monitor_fdset_fd_free(MonFdsetFd *mon_fdset_fd) |
| 189 | { |
| 190 | close(mon_fdset_fd->fd); |
| 191 | g_free(mon_fdset_fd->opaque); |
| 192 | QLIST_REMOVE(mon_fdset_fd, next); |
| 193 | g_free(mon_fdset_fd); |
| 194 | } |
| 195 | |
| 196 | void monitor_fdsets_cleanup(void) |
| 197 | { |
| 198 | MonFdset *mon_fdset; |
| 199 | MonFdset *mon_fdset_next; |
| 200 | |
| 201 | QEMU_LOCK_GUARD(&mon_fdsets_lock); |
| 202 | QLIST_FOREACH_SAFE(mon_fdset, &mon_fdsets, next, mon_fdset_next) { |
| 203 | monitor_fdset_free_if_empty(mon_fdset); |
| 204 | } |
| 205 | } |
| 206 | |
| 207 | AddfdInfo *qmp_add_fd(bool has_fdset_id, int64_t fdset_id, |
| 208 | const char *opaque, Error **errp) |
| 209 | { |
| 210 | int fd; |
| 211 | Monitor *mon = monitor_cur(); |
| 212 | AddfdInfo *fdinfo; |
| 213 | |
| 214 | fd = qemu_chr_fe_get_msgfd(&mon->chr); |
| 215 | if (fd == -1) { |
| 216 | error_setg(errp, "No file descriptor supplied via SCM_RIGHTS"); |
| 217 | goto error; |
| 218 | } |
| 219 | |
| 220 | fdinfo = monitor_fdset_add_fd(fd, has_fdset_id, fdset_id, opaque, errp); |
| 221 | if (fdinfo) { |
| 222 | return fdinfo; |
| 223 | } |
| 224 | |
| 225 | error: |
| 226 | if (fd != -1) { |
| 227 | close(fd); |
| 228 | } |
| 229 | return NULL; |
| 230 | } |
| 231 | |
| 232 | #ifdef WIN32 |
| 233 | void qmp_get_win32_socket(const char *infos, const char *fdname, Error **errp) |
| 234 | { |
| 235 | g_autofree WSAPROTOCOL_INFOW *info = NULL; |
| 236 | gsize len; |
| 237 | SOCKET sk; |
| 238 | int fd; |
| 239 | |
| 240 | info = (void *)g_base64_decode(infos, &len); |
| 241 | if (len != sizeof(*info)) { |
| 242 | error_setg(errp, "Invalid WSAPROTOCOL_INFOW value"); |
| 243 | return; |
| 244 | } |
| 245 | |
| 246 | sk = WSASocketW(FROM_PROTOCOL_INFO, |
| 247 | FROM_PROTOCOL_INFO, |
| 248 | FROM_PROTOCOL_INFO, |
| 249 | info, 0, 0); |
| 250 | if (sk == INVALID_SOCKET) { |
| 251 | error_setg_win32(errp, WSAGetLastError(), "Couldn't import socket"); |
| 252 | return; |
| 253 | } |
| 254 | |
| 255 | fd = _open_osfhandle(sk, _O_BINARY); |
| 256 | if (fd < 0) { |
| 257 | error_setg_errno(errp, errno, "Failed to associate a FD with the SOCKET"); |
| 258 | closesocket(sk); |
| 259 | return; |
| 260 | } |
| 261 | |
| 262 | monitor_add_fd(monitor_cur(), fd, fdname, errp); |
| 263 | } |
| 264 | #endif |
| 265 | |
| 266 | |
| 267 | void qmp_remove_fd(int64_t fdset_id, bool has_fd, int64_t fd, Error **errp) |
| 268 | { |
| 269 | MonFdset *mon_fdset; |
| 270 | MonFdsetFd *mon_fdset_fd, *mon_fdset_fd_next; |
| 271 | char fd_str[60]; |
| 272 | |
| 273 | QEMU_LOCK_GUARD(&mon_fdsets_lock); |
| 274 | QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { |
| 275 | if (mon_fdset->id != fdset_id) { |
| 276 | continue; |
| 277 | } |
| 278 | QLIST_FOREACH_SAFE(mon_fdset_fd, &mon_fdset->fds, next, |
| 279 | mon_fdset_fd_next) { |
| 280 | if (has_fd) { |
| 281 | if (mon_fdset_fd->fd != fd) { |
| 282 | continue; |
| 283 | } |
| 284 | monitor_fdset_fd_free(mon_fdset_fd); |
| 285 | break; |
| 286 | } else { |
| 287 | monitor_fdset_fd_free(mon_fdset_fd); |
| 288 | } |
| 289 | } |
| 290 | if (has_fd && !mon_fdset_fd) { |
| 291 | goto error; |
| 292 | } |
| 293 | monitor_fdset_free_if_empty(mon_fdset); |
| 294 | return; |
| 295 | } |
| 296 | |
| 297 | error: |
| 298 | if (has_fd) { |
| 299 | snprintf(fd_str, sizeof(fd_str), "fdset-id:%" PRId64 ", fd:%" PRId64, |
| 300 | fdset_id, fd); |
| 301 | } else { |
| 302 | snprintf(fd_str, sizeof(fd_str), "fdset-id:%" PRId64, fdset_id); |
| 303 | } |
| 304 | error_setg(errp, "File descriptor named '%s' not found", fd_str); |
| 305 | } |
| 306 | |
| 307 | FdsetInfoList *qmp_query_fdsets(Error **errp) |
| 308 | { |
| 309 | MonFdset *mon_fdset; |
| 310 | MonFdsetFd *mon_fdset_fd; |
| 311 | FdsetInfoList *fdset_list = NULL; |
| 312 | |
| 313 | QEMU_LOCK_GUARD(&mon_fdsets_lock); |
| 314 | QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { |
| 315 | FdsetInfo *fdset_info = g_malloc0(sizeof(*fdset_info)); |
| 316 | |
| 317 | fdset_info->fdset_id = mon_fdset->id; |
| 318 | |
| 319 | QLIST_FOREACH(mon_fdset_fd, &mon_fdset->fds, next) { |
| 320 | FdsetFdInfo *fdsetfd_info; |
| 321 | |
| 322 | fdsetfd_info = g_malloc0(sizeof(*fdsetfd_info)); |
| 323 | fdsetfd_info->fd = mon_fdset_fd->fd; |
| 324 | fdsetfd_info->opaque = g_strdup(mon_fdset_fd->opaque); |
| 325 | |
| 326 | QAPI_LIST_PREPEND(fdset_info->fds, fdsetfd_info); |
| 327 | } |
| 328 | |
| 329 | QAPI_LIST_PREPEND(fdset_list, fdset_info); |
| 330 | } |
| 331 | |
| 332 | return fdset_list; |
| 333 | } |
| 334 | |
| 335 | AddfdInfo *monitor_fdset_add_fd(int fd, bool has_fdset_id, int64_t fdset_id, |
| 336 | const char *opaque, Error **errp) |
| 337 | { |
| 338 | MonFdset *mon_fdset = NULL; |
| 339 | MonFdsetFd *mon_fdset_fd; |
| 340 | AddfdInfo *fdinfo; |
| 341 | |
| 342 | QEMU_LOCK_GUARD(&mon_fdsets_lock); |
| 343 | if (has_fdset_id) { |
| 344 | QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { |
| 345 | /* Break if match found or match impossible due to ordering by ID */ |
| 346 | if (fdset_id <= mon_fdset->id) { |
| 347 | if (fdset_id < mon_fdset->id) { |
| 348 | mon_fdset = NULL; |
| 349 | } |
| 350 | break; |
| 351 | } |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | if (mon_fdset == NULL) { |
| 356 | int64_t fdset_id_prev = -1; |
| 357 | MonFdset *mon_fdset_cur = QLIST_FIRST(&mon_fdsets); |
| 358 | |
| 359 | if (has_fdset_id) { |
| 360 | if (fdset_id < 0) { |
| 361 | error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "fdset-id", |
| 362 | "a non-negative value"); |
| 363 | return NULL; |
| 364 | } |
| 365 | /* Use specified fdset ID */ |
| 366 | QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { |
| 367 | mon_fdset_cur = mon_fdset; |
| 368 | if (fdset_id < mon_fdset_cur->id) { |
| 369 | break; |
| 370 | } |
| 371 | } |
| 372 | } else { |
| 373 | /* Use first available fdset ID */ |
| 374 | QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { |
| 375 | mon_fdset_cur = mon_fdset; |
| 376 | if (fdset_id_prev == mon_fdset_cur->id - 1) { |
| 377 | fdset_id_prev = mon_fdset_cur->id; |
| 378 | continue; |
| 379 | } |
| 380 | break; |
| 381 | } |
| 382 | } |
| 383 | |
| 384 | mon_fdset = g_malloc0(sizeof(*mon_fdset)); |
| 385 | if (has_fdset_id) { |
| 386 | mon_fdset->id = fdset_id; |
| 387 | } else { |
| 388 | mon_fdset->id = fdset_id_prev + 1; |
| 389 | } |
| 390 | |
| 391 | /* The fdset list is ordered by fdset ID */ |
| 392 | if (!mon_fdset_cur) { |
| 393 | QLIST_INSERT_HEAD(&mon_fdsets, mon_fdset, next); |
| 394 | } else if (mon_fdset->id < mon_fdset_cur->id) { |
| 395 | QLIST_INSERT_BEFORE(mon_fdset_cur, mon_fdset, next); |
| 396 | } else { |
| 397 | QLIST_INSERT_AFTER(mon_fdset_cur, mon_fdset, next); |
| 398 | } |
| 399 | } |
| 400 | |
| 401 | mon_fdset_fd = g_malloc0(sizeof(*mon_fdset_fd)); |
| 402 | mon_fdset_fd->fd = fd; |
| 403 | mon_fdset_fd->opaque = g_strdup(opaque); |
| 404 | QLIST_INSERT_HEAD(&mon_fdset->fds, mon_fdset_fd, next); |
| 405 | |
| 406 | fdinfo = g_malloc0(sizeof(*fdinfo)); |
| 407 | fdinfo->fdset_id = mon_fdset->id; |
| 408 | fdinfo->fd = mon_fdset_fd->fd; |
| 409 | |
| 410 | return fdinfo; |
| 411 | } |
| 412 | |
| 413 | int monitor_fdset_dup_fd_add(int64_t fdset_id, int flags, Error **errp) |
| 414 | { |
| 415 | #ifdef _WIN32 |
| 416 | error_setg(errp, "Platform does not support fd passing (fdset)"); |
| 417 | return -ENOENT; |
| 418 | #else |
| 419 | MonFdset *mon_fdset; |
| 420 | |
| 421 | QEMU_LOCK_GUARD(&mon_fdsets_lock); |
| 422 | QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { |
| 423 | MonFdsetFd *mon_fdset_fd; |
| 424 | MonFdsetFd *mon_fdset_fd_dup; |
| 425 | int fd = -1; |
| 426 | int dup_fd; |
| 427 | int mon_fd_flags; |
| 428 | int mask = O_ACCMODE; |
| 429 | |
| 430 | #ifdef O_DIRECT |
| 431 | mask |= O_DIRECT; |
| 432 | #endif |
| 433 | |
| 434 | if (mon_fdset->id != fdset_id) { |
| 435 | continue; |
| 436 | } |
| 437 | |
| 438 | QLIST_FOREACH(mon_fdset_fd, &mon_fdset->fds, next) { |
| 439 | mon_fd_flags = fcntl(mon_fdset_fd->fd, F_GETFL); |
| 440 | if (mon_fd_flags == -1) { |
| 441 | error_setg(errp, "Failed to read file status flags for fd=%d", |
| 442 | mon_fdset_fd->fd); |
| 443 | return -1; |
| 444 | } |
| 445 | |
| 446 | if ((flags & mask) == (mon_fd_flags & mask)) { |
| 447 | fd = mon_fdset_fd->fd; |
| 448 | break; |
| 449 | } |
| 450 | } |
| 451 | |
| 452 | if (fd == -1) { |
| 453 | errno = EACCES; |
| 454 | error_setg(errp, |
| 455 | "Failed to find file descriptor with matching flags=0x%x", |
| 456 | flags); |
| 457 | return -1; |
| 458 | } |
| 459 | |
| 460 | dup_fd = qemu_dup_flags(fd, flags); |
| 461 | if (dup_fd == -1) { |
| 462 | error_setg(errp, "Failed to dup() given file descriptor fd=%d", fd); |
| 463 | return -1; |
| 464 | } |
| 465 | |
| 466 | mon_fdset_fd_dup = g_malloc0(sizeof(*mon_fdset_fd_dup)); |
| 467 | mon_fdset_fd_dup->fd = dup_fd; |
| 468 | QLIST_INSERT_HEAD(&mon_fdset->dup_fds, mon_fdset_fd_dup, next); |
| 469 | return dup_fd; |
| 470 | } |
| 471 | |
| 472 | error_setg(errp, "Failed to find fdset /dev/fdset/%" PRId64, fdset_id); |
| 473 | errno = ENOENT; |
| 474 | return -1; |
| 475 | #endif |
| 476 | } |
| 477 | |
| 478 | void monitor_fdset_dup_fd_remove(int dup_fd) |
| 479 | { |
| 480 | MonFdset *mon_fdset; |
| 481 | MonFdsetFd *mon_fdset_fd_dup; |
| 482 | |
| 483 | QEMU_LOCK_GUARD(&mon_fdsets_lock); |
| 484 | QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { |
| 485 | QLIST_FOREACH(mon_fdset_fd_dup, &mon_fdset->dup_fds, next) { |
| 486 | if (mon_fdset_fd_dup->fd == dup_fd) { |
| 487 | QLIST_REMOVE(mon_fdset_fd_dup, next); |
| 488 | g_free(mon_fdset_fd_dup); |
| 489 | monitor_fdset_free_if_empty(mon_fdset); |
| 490 | return; |
| 491 | } |
| 492 | } |
| 493 | } |
| 494 | } |
| 495 | |
| 496 | int monitor_fd_param(Monitor *mon, const char *fdname, Error **errp) |
| 497 | { |
| 498 | int fd; |
| 499 | |
| 500 | if (!qemu_isdigit(fdname[0]) && mon) { |
| 501 | fd = monitor_get_fd(mon, fdname, errp); |
| 502 | } else { |
| 503 | fd = qemu_parse_fd(fdname); |
| 504 | if (fd < 0) { |
| 505 | error_setg(errp, "Invalid file descriptor number '%s'", |
| 506 | fdname); |
| 507 | } |
| 508 | } |
| 509 | |
| 510 | return fd; |
| 511 | } |
| 512 | |
| 513 | static void __attribute__((__constructor__)) monitor_fds_init(void) |
| 514 | { |
| 515 | qemu_mutex_init(&mon_fdsets_lock); |
| 516 | } |