1 /* 2 * Privileged helper to handle persistent reservation commands for QEMU 3 * 4 * Copyright (C) 2017 Red Hat, Inc. <pbonzini@redhat.com> 5 * 6 * Author: Paolo Bonzini <pbonzini@redhat.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; under version 2 of the License. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, see <http://www.gnu.org/licenses/>. 19 */ 20 21 #include "qemu/osdep.h" 22 #include <getopt.h> 23 #include <sys/ioctl.h> 24 #include <linux/dm-ioctl.h> 25 #include <scsi/sg.h> 26 27 #ifdef CONFIG_LIBCAP_NG 28 #include <cap-ng.h> 29 #endif 30 #include <pwd.h> 31 #include <grp.h> 32 33 #ifdef CONFIG_MPATH 34 #include <libudev.h> 35 #include <mpath_cmd.h> 36 #include <mpath_persist.h> 37 #endif 38 39 #include "qemu-common.h" 40 #include "qapi/error.h" 41 #include "qemu/cutils.h" 42 #include "qemu/main-loop.h" 43 #include "qemu/module.h" 44 #include "qemu/error-report.h" 45 #include "qemu/config-file.h" 46 #include "qemu/bswap.h" 47 #include "qemu/log.h" 48 #include "qemu/systemd.h" 49 #include "qapi/util.h" 50 #include "qapi/qmp/qstring.h" 51 #include "io/channel-socket.h" 52 #include "trace/control.h" 53 #include "qemu-version.h" 54 55 #include "block/aio.h" 56 #include "block/thread-pool.h" 57 58 #include "scsi/constants.h" 59 #include "scsi/utils.h" 60 #include "pr-helper.h" 61 62 #define PR_OUT_FIXED_PARAM_SIZE 24 63 64 static char *socket_path; 65 static char *pidfile; 66 static enum { RUNNING, TERMINATE, TERMINATING } state; 67 static QIOChannelSocket *server_ioc; 68 static int server_watch; 69 static int num_active_sockets = 1; 70 static int noisy; 71 static int verbose; 72 73 #ifdef CONFIG_LIBCAP_NG 74 static int uid = -1; 75 static int gid = -1; 76 #endif 77 78 static void compute_default_paths(void) 79 { 80 socket_path = qemu_get_local_state_pathname("run/qemu-pr-helper.sock"); 81 pidfile = qemu_get_local_state_pathname("run/qemu-pr-helper.pid"); 82 } 83 84 static void usage(const char *name) 85 { 86 (printf) ( 87 "Usage: %s [OPTIONS] FILE\n" 88 "Persistent Reservation helper program for QEMU\n" 89 "\n" 90 " -h, --help display this help and exit\n" 91 " -V, --version output version information and exit\n" 92 "\n" 93 " -d, --daemon run in the background\n" 94 " -f, --pidfile=PATH PID file when running as a daemon\n" 95 " (default '%s')\n" 96 " -k, --socket=PATH path to the unix socket\n" 97 " (default '%s')\n" 98 " -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 99 " specify tracing options\n" 100 #ifdef CONFIG_LIBCAP_NG 101 " -u, --user=USER user to drop privileges to\n" 102 " -g, --group=GROUP group to drop privileges to\n" 103 #endif 104 "\n" 105 QEMU_HELP_BOTTOM "\n" 106 , name, pidfile, socket_path); 107 } 108 109 static void version(const char *name) 110 { 111 printf( 112 "%s " QEMU_FULL_VERSION "\n" 113 "Written by Paolo Bonzini.\n" 114 "\n" 115 QEMU_COPYRIGHT "\n" 116 "This is free software; see the source for copying conditions. There is NO\n" 117 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" 118 , name); 119 } 120 121 /* SG_IO support */ 122 123 typedef struct PRHelperSGIOData { 124 int fd; 125 const uint8_t *cdb; 126 uint8_t *sense; 127 uint8_t *buf; 128 int sz; /* input/output */ 129 int dir; 130 } PRHelperSGIOData; 131 132 static int do_sgio_worker(void *opaque) 133 { 134 PRHelperSGIOData *data = opaque; 135 struct sg_io_hdr io_hdr; 136 int ret; 137 int status; 138 SCSISense sense_code; 139 140 memset(data->sense, 0, PR_HELPER_SENSE_SIZE); 141 memset(&io_hdr, 0, sizeof(io_hdr)); 142 io_hdr.interface_id = 'S'; 143 io_hdr.cmd_len = PR_HELPER_CDB_SIZE; 144 io_hdr.cmdp = (uint8_t *)data->cdb; 145 io_hdr.sbp = data->sense; 146 io_hdr.mx_sb_len = PR_HELPER_SENSE_SIZE; 147 io_hdr.timeout = 1; 148 io_hdr.dxfer_direction = data->dir; 149 io_hdr.dxferp = (char *)data->buf; 150 io_hdr.dxfer_len = data->sz; 151 ret = ioctl(data->fd, SG_IO, &io_hdr); 152 153 if (ret < 0) { 154 status = scsi_sense_from_errno(errno, &sense_code); 155 if (status == CHECK_CONDITION) { 156 scsi_build_sense(data->sense, sense_code); 157 } 158 } else if (io_hdr.host_status != SCSI_HOST_OK) { 159 status = scsi_sense_from_host_status(io_hdr.host_status, &sense_code); 160 if (status == CHECK_CONDITION) { 161 scsi_build_sense(data->sense, sense_code); 162 } 163 } else if (io_hdr.driver_status & SG_ERR_DRIVER_TIMEOUT) { 164 status = BUSY; 165 } else { 166 status = io_hdr.status; 167 } 168 169 if (status == GOOD) { 170 data->sz -= io_hdr.resid; 171 } else { 172 data->sz = 0; 173 } 174 175 return status; 176 } 177 178 static int do_sgio(int fd, const uint8_t *cdb, uint8_t *sense, 179 uint8_t *buf, int *sz, int dir) 180 { 181 ThreadPool *pool = aio_get_thread_pool(qemu_get_aio_context()); 182 int r; 183 184 PRHelperSGIOData data = { 185 .fd = fd, 186 .cdb = cdb, 187 .sense = sense, 188 .buf = buf, 189 .sz = *sz, 190 .dir = dir, 191 }; 192 193 r = thread_pool_submit_co(pool, do_sgio_worker, &data); 194 *sz = data.sz; 195 return r; 196 } 197 198 /* Device mapper interface */ 199 200 #ifdef CONFIG_MPATH 201 #define CONTROL_PATH "/dev/mapper/control" 202 203 typedef struct DMData { 204 struct dm_ioctl dm; 205 uint8_t data[1024]; 206 } DMData; 207 208 static int control_fd; 209 210 static void *dm_ioctl(int ioc, struct dm_ioctl *dm) 211 { 212 static DMData d; 213 memcpy(&d.dm, dm, sizeof(d.dm)); 214 QEMU_BUILD_BUG_ON(sizeof(d.data) < sizeof(struct dm_target_spec)); 215 216 d.dm.version[0] = DM_VERSION_MAJOR; 217 d.dm.version[1] = 0; 218 d.dm.version[2] = 0; 219 d.dm.data_size = 1024; 220 d.dm.data_start = offsetof(DMData, data); 221 if (ioctl(control_fd, ioc, &d) < 0) { 222 return NULL; 223 } 224 memcpy(dm, &d.dm, sizeof(d.dm)); 225 return &d.data; 226 } 227 228 static void *dm_dev_ioctl(int fd, int ioc, struct dm_ioctl *dm) 229 { 230 struct stat st; 231 int r; 232 233 r = fstat(fd, &st); 234 if (r < 0) { 235 perror("fstat"); 236 exit(1); 237 } 238 239 dm->dev = st.st_rdev; 240 return dm_ioctl(ioc, dm); 241 } 242 243 static void dm_init(void) 244 { 245 control_fd = open(CONTROL_PATH, O_RDWR); 246 if (control_fd < 0) { 247 perror("Cannot open " CONTROL_PATH); 248 exit(1); 249 } 250 struct dm_ioctl dm = { }; 251 if (!dm_ioctl(DM_VERSION, &dm)) { 252 perror("ioctl"); 253 exit(1); 254 } 255 if (dm.version[0] != DM_VERSION_MAJOR) { 256 fprintf(stderr, "Unsupported device mapper interface"); 257 exit(1); 258 } 259 } 260 261 /* Variables required by libmultipath and libmpathpersist. */ 262 QEMU_BUILD_BUG_ON(PR_HELPER_DATA_SIZE > MPATH_MAX_PARAM_LEN); 263 static struct config *multipath_conf; 264 unsigned mpath_mx_alloc_len = PR_HELPER_DATA_SIZE; 265 int logsink; 266 struct udev *udev; 267 268 extern struct config *get_multipath_config(void); 269 struct config *get_multipath_config(void) 270 { 271 return multipath_conf; 272 } 273 274 extern void put_multipath_config(struct config *conf); 275 void put_multipath_config(struct config *conf) 276 { 277 } 278 279 static void multipath_pr_init(void) 280 { 281 udev = udev_new(); 282 #ifdef CONFIG_MPATH_NEW_API 283 multipath_conf = mpath_lib_init(); 284 #else 285 mpath_lib_init(udev); 286 #endif 287 } 288 289 static int is_mpath(int fd) 290 { 291 struct dm_ioctl dm = { .flags = DM_NOFLUSH_FLAG }; 292 struct dm_target_spec *tgt; 293 294 tgt = dm_dev_ioctl(fd, DM_TABLE_STATUS, &dm); 295 if (!tgt) { 296 if (errno == ENXIO) { 297 return 0; 298 } 299 perror("ioctl"); 300 exit(EXIT_FAILURE); 301 } 302 return !strncmp(tgt->target_type, "multipath", DM_MAX_TYPE_NAME); 303 } 304 305 static SCSISense mpath_generic_sense(int r) 306 { 307 switch (r) { 308 case MPATH_PR_SENSE_NOT_READY: 309 return SENSE_CODE(NOT_READY); 310 case MPATH_PR_SENSE_MEDIUM_ERROR: 311 return SENSE_CODE(READ_ERROR); 312 case MPATH_PR_SENSE_HARDWARE_ERROR: 313 return SENSE_CODE(TARGET_FAILURE); 314 case MPATH_PR_SENSE_ABORTED_COMMAND: 315 return SENSE_CODE(IO_ERROR); 316 default: 317 abort(); 318 } 319 } 320 321 static int mpath_reconstruct_sense(int fd, int r, uint8_t *sense) 322 { 323 switch (r) { 324 case MPATH_PR_SUCCESS: 325 return GOOD; 326 case MPATH_PR_SENSE_NOT_READY: 327 case MPATH_PR_SENSE_MEDIUM_ERROR: 328 case MPATH_PR_SENSE_HARDWARE_ERROR: 329 case MPATH_PR_SENSE_ABORTED_COMMAND: 330 { 331 /* libmpathpersist ate the exact sense. Try to find it by 332 * issuing TEST UNIT READY. 333 */ 334 uint8_t cdb[6] = { TEST_UNIT_READY }; 335 int sz = 0; 336 int ret = do_sgio(fd, cdb, sense, NULL, &sz, SG_DXFER_NONE); 337 338 if (ret != GOOD) { 339 return ret; 340 } 341 scsi_build_sense(sense, mpath_generic_sense(r)); 342 return CHECK_CONDITION; 343 } 344 345 case MPATH_PR_SENSE_UNIT_ATTENTION: 346 /* Congratulations libmpathpersist, you ruined the Unit Attention... 347 * Return a heavyweight one. 348 */ 349 scsi_build_sense(sense, SENSE_CODE(SCSI_BUS_RESET)); 350 return CHECK_CONDITION; 351 case MPATH_PR_SENSE_INVALID_OP: 352 /* Only one valid sense. */ 353 scsi_build_sense(sense, SENSE_CODE(INVALID_OPCODE)); 354 return CHECK_CONDITION; 355 case MPATH_PR_ILLEGAL_REQ: 356 /* Guess. */ 357 scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM)); 358 return CHECK_CONDITION; 359 case MPATH_PR_NO_SENSE: 360 scsi_build_sense(sense, SENSE_CODE(NO_SENSE)); 361 return CHECK_CONDITION; 362 363 case MPATH_PR_RESERV_CONFLICT: 364 return RESERVATION_CONFLICT; 365 366 case MPATH_PR_OTHER: 367 default: 368 scsi_build_sense(sense, SENSE_CODE(LUN_COMM_FAILURE)); 369 return CHECK_CONDITION; 370 } 371 } 372 373 static int multipath_pr_in(int fd, const uint8_t *cdb, uint8_t *sense, 374 uint8_t *data, int sz) 375 { 376 int rq_servact = cdb[1]; 377 struct prin_resp resp; 378 size_t written; 379 int r; 380 381 switch (rq_servact) { 382 case MPATH_PRIN_RKEY_SA: 383 case MPATH_PRIN_RRES_SA: 384 case MPATH_PRIN_RCAP_SA: 385 break; 386 case MPATH_PRIN_RFSTAT_SA: 387 /* Nobody implements it anyway, so bail out. */ 388 default: 389 /* Cannot parse any other output. */ 390 scsi_build_sense(sense, SENSE_CODE(INVALID_FIELD)); 391 return CHECK_CONDITION; 392 } 393 394 r = mpath_persistent_reserve_in(fd, rq_servact, &resp, noisy, verbose); 395 if (r == MPATH_PR_SUCCESS) { 396 switch (rq_servact) { 397 case MPATH_PRIN_RKEY_SA: 398 case MPATH_PRIN_RRES_SA: { 399 struct prin_readdescr *out = &resp.prin_descriptor.prin_readkeys; 400 assert(sz >= 8); 401 written = MIN(out->additional_length + 8, sz); 402 stl_be_p(&data[0], out->prgeneration); 403 stl_be_p(&data[4], out->additional_length); 404 memcpy(&data[8], out->key_list, written - 8); 405 break; 406 } 407 case MPATH_PRIN_RCAP_SA: { 408 struct prin_capdescr *out = &resp.prin_descriptor.prin_readcap; 409 assert(sz >= 6); 410 written = 6; 411 stw_be_p(&data[0], out->length); 412 data[2] = out->flags[0]; 413 data[3] = out->flags[1]; 414 stw_be_p(&data[4], out->pr_type_mask); 415 break; 416 } 417 default: 418 scsi_build_sense(sense, SENSE_CODE(INVALID_OPCODE)); 419 return CHECK_CONDITION; 420 } 421 assert(written <= sz); 422 memset(data + written, 0, sz - written); 423 } 424 425 return mpath_reconstruct_sense(fd, r, sense); 426 } 427 428 static int multipath_pr_out(int fd, const uint8_t *cdb, uint8_t *sense, 429 const uint8_t *param, int sz) 430 { 431 int rq_servact = cdb[1]; 432 int rq_scope = cdb[2] >> 4; 433 int rq_type = cdb[2] & 0xf; 434 g_autofree struct prout_param_descriptor *paramp = NULL; 435 char transportids[PR_HELPER_DATA_SIZE]; 436 int r; 437 438 paramp = g_malloc0(sizeof(struct prout_param_descriptor) 439 + sizeof(struct transportid *) * MPATH_MX_TIDS); 440 441 if (sz < PR_OUT_FIXED_PARAM_SIZE) { 442 /* Illegal request, Parameter list length error. This isn't fatal; 443 * we have read the data, send an error without closing the socket. 444 */ 445 scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM_LEN)); 446 return CHECK_CONDITION; 447 } 448 449 switch (rq_servact) { 450 case MPATH_PROUT_REG_SA: 451 case MPATH_PROUT_RES_SA: 452 case MPATH_PROUT_REL_SA: 453 case MPATH_PROUT_CLEAR_SA: 454 case MPATH_PROUT_PREE_SA: 455 case MPATH_PROUT_PREE_AB_SA: 456 case MPATH_PROUT_REG_IGN_SA: 457 break; 458 case MPATH_PROUT_REG_MOV_SA: 459 /* Not supported by struct prout_param_descriptor. */ 460 default: 461 /* Cannot parse any other input. */ 462 scsi_build_sense(sense, SENSE_CODE(INVALID_FIELD)); 463 return CHECK_CONDITION; 464 } 465 466 /* Convert input data, especially transport IDs, to the structs 467 * used by libmpathpersist (which, of course, will immediately 468 * do the opposite). 469 */ 470 memcpy(¶mp->key, ¶m[0], 8); 471 memcpy(¶mp->sa_key, ¶m[8], 8); 472 paramp->sa_flags = param[20]; 473 if (sz > PR_OUT_FIXED_PARAM_SIZE) { 474 size_t transportid_len; 475 int i, j; 476 if (sz < PR_OUT_FIXED_PARAM_SIZE + 4) { 477 scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM_LEN)); 478 return CHECK_CONDITION; 479 } 480 transportid_len = ldl_be_p(¶m[24]) + PR_OUT_FIXED_PARAM_SIZE + 4; 481 if (transportid_len > sz) { 482 scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM)); 483 return CHECK_CONDITION; 484 } 485 for (i = PR_OUT_FIXED_PARAM_SIZE + 4, j = 0; i < transportid_len; ) { 486 struct transportid *id = (struct transportid *) &transportids[j]; 487 int len; 488 489 id->format_code = param[i] & 0xc0; 490 id->protocol_id = param[i] & 0x0f; 491 switch (param[i] & 0xcf) { 492 case 0: 493 /* FC transport. */ 494 if (i + 24 > transportid_len) { 495 goto illegal_req; 496 } 497 memcpy(id->n_port_name, ¶m[i + 8], 8); 498 j += offsetof(struct transportid, n_port_name[8]); 499 i += 24; 500 break; 501 case 5: 502 case 0x45: 503 /* iSCSI transport. */ 504 len = lduw_be_p(¶m[i + 2]); 505 if (len > 252 || (len & 3) || i + len + 4 > transportid_len) { 506 /* For format code 00, the standard says the maximum is 223 507 * plus the NUL terminator. For format code 01 there is no 508 * maximum length, but libmpathpersist ignores the first 509 * byte of id->iscsi_name so our maximum is 252. 510 */ 511 goto illegal_req; 512 } 513 if (memchr(¶m[i + 4], 0, len) == NULL) { 514 goto illegal_req; 515 } 516 memcpy(id->iscsi_name, ¶m[i + 2], len + 2); 517 j += offsetof(struct transportid, iscsi_name[len + 2]); 518 i += len + 4; 519 break; 520 case 6: 521 /* SAS transport. */ 522 if (i + 24 > transportid_len) { 523 goto illegal_req; 524 } 525 memcpy(id->sas_address, ¶m[i + 4], 8); 526 j += offsetof(struct transportid, sas_address[8]); 527 i += 24; 528 break; 529 default: 530 illegal_req: 531 scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM)); 532 return CHECK_CONDITION; 533 } 534 535 assert(paramp->num_transportid < MPATH_MX_TIDS); 536 paramp->trnptid_list[paramp->num_transportid++] = id; 537 } 538 } 539 540 r = mpath_persistent_reserve_out(fd, rq_servact, rq_scope, rq_type, 541 paramp, noisy, verbose); 542 return mpath_reconstruct_sense(fd, r, sense); 543 } 544 #endif 545 546 static int do_pr_in(int fd, const uint8_t *cdb, uint8_t *sense, 547 uint8_t *data, int *resp_sz) 548 { 549 #ifdef CONFIG_MPATH 550 if (is_mpath(fd)) { 551 /* multipath_pr_in fills the whole input buffer. */ 552 int r = multipath_pr_in(fd, cdb, sense, data, *resp_sz); 553 if (r != GOOD) { 554 *resp_sz = 0; 555 } 556 return r; 557 } 558 #endif 559 560 return do_sgio(fd, cdb, sense, data, resp_sz, 561 SG_DXFER_FROM_DEV); 562 } 563 564 static int do_pr_out(int fd, const uint8_t *cdb, uint8_t *sense, 565 const uint8_t *param, int sz) 566 { 567 int resp_sz; 568 569 if ((fcntl(fd, F_GETFL) & O_ACCMODE) == O_RDONLY) { 570 scsi_build_sense(sense, SENSE_CODE(INVALID_OPCODE)); 571 return CHECK_CONDITION; 572 } 573 574 #ifdef CONFIG_MPATH 575 if (is_mpath(fd)) { 576 return multipath_pr_out(fd, cdb, sense, param, sz); 577 } 578 #endif 579 580 resp_sz = sz; 581 return do_sgio(fd, cdb, sense, (uint8_t *)param, &resp_sz, 582 SG_DXFER_TO_DEV); 583 } 584 585 /* Client */ 586 587 typedef struct PRHelperClient { 588 QIOChannelSocket *ioc; 589 Coroutine *co; 590 int fd; 591 uint8_t data[PR_HELPER_DATA_SIZE]; 592 } PRHelperClient; 593 594 typedef struct PRHelperRequest { 595 int fd; 596 size_t sz; 597 uint8_t cdb[PR_HELPER_CDB_SIZE]; 598 } PRHelperRequest; 599 600 static int coroutine_fn prh_read(PRHelperClient *client, void *buf, int sz, 601 Error **errp) 602 { 603 int ret = 0; 604 605 while (sz > 0) { 606 int *fds = NULL; 607 size_t nfds = 0; 608 int i; 609 struct iovec iov; 610 ssize_t n_read; 611 612 iov.iov_base = buf; 613 iov.iov_len = sz; 614 n_read = qio_channel_readv_full(QIO_CHANNEL(client->ioc), &iov, 1, 615 &fds, &nfds, errp); 616 617 if (n_read == QIO_CHANNEL_ERR_BLOCK) { 618 qio_channel_yield(QIO_CHANNEL(client->ioc), G_IO_IN); 619 continue; 620 } 621 if (n_read <= 0) { 622 ret = n_read ? n_read : -1; 623 goto err; 624 } 625 626 /* Stash one file descriptor per request. */ 627 if (nfds) { 628 bool too_many = false; 629 for (i = 0; i < nfds; i++) { 630 if (client->fd == -1) { 631 client->fd = fds[i]; 632 } else { 633 close(fds[i]); 634 too_many = true; 635 } 636 } 637 g_free(fds); 638 if (too_many) { 639 ret = -1; 640 goto err; 641 } 642 } 643 644 buf += n_read; 645 sz -= n_read; 646 } 647 648 return 0; 649 650 err: 651 if (client->fd != -1) { 652 close(client->fd); 653 client->fd = -1; 654 } 655 return ret; 656 } 657 658 static int coroutine_fn prh_read_request(PRHelperClient *client, 659 PRHelperRequest *req, 660 PRHelperResponse *resp, Error **errp) 661 { 662 uint32_t sz; 663 664 if (prh_read(client, req->cdb, sizeof(req->cdb), NULL) < 0) { 665 return -1; 666 } 667 668 if (client->fd == -1) { 669 error_setg(errp, "No file descriptor in request."); 670 return -1; 671 } 672 673 if (req->cdb[0] != PERSISTENT_RESERVE_OUT && 674 req->cdb[0] != PERSISTENT_RESERVE_IN) { 675 error_setg(errp, "Invalid CDB, closing socket."); 676 goto out_close; 677 } 678 679 sz = scsi_cdb_xfer(req->cdb); 680 if (sz > sizeof(client->data)) { 681 goto out_close; 682 } 683 684 if (req->cdb[0] == PERSISTENT_RESERVE_OUT) { 685 if (qio_channel_read_all(QIO_CHANNEL(client->ioc), 686 (char *)client->data, sz, 687 errp) < 0) { 688 goto out_close; 689 } 690 } 691 692 req->fd = client->fd; 693 req->sz = sz; 694 client->fd = -1; 695 return sz; 696 697 out_close: 698 close(client->fd); 699 client->fd = -1; 700 return -1; 701 } 702 703 static int coroutine_fn prh_write_response(PRHelperClient *client, 704 PRHelperRequest *req, 705 PRHelperResponse *resp, Error **errp) 706 { 707 ssize_t r; 708 size_t sz; 709 710 if (req->cdb[0] == PERSISTENT_RESERVE_IN && resp->result == GOOD) { 711 assert(resp->sz <= req->sz && resp->sz <= sizeof(client->data)); 712 } else { 713 assert(resp->sz == 0); 714 } 715 716 sz = resp->sz; 717 718 resp->result = cpu_to_be32(resp->result); 719 resp->sz = cpu_to_be32(resp->sz); 720 r = qio_channel_write_all(QIO_CHANNEL(client->ioc), 721 (char *) resp, sizeof(*resp), errp); 722 if (r < 0) { 723 return r; 724 } 725 726 r = qio_channel_write_all(QIO_CHANNEL(client->ioc), 727 (char *) client->data, 728 sz, errp); 729 return r < 0 ? r : 0; 730 } 731 732 static void coroutine_fn prh_co_entry(void *opaque) 733 { 734 PRHelperClient *client = opaque; 735 Error *local_err = NULL; 736 uint32_t flags; 737 int r; 738 739 qio_channel_set_blocking(QIO_CHANNEL(client->ioc), 740 false, NULL); 741 qio_channel_attach_aio_context(QIO_CHANNEL(client->ioc), 742 qemu_get_aio_context()); 743 744 /* A very simple negotiation for future extensibility. No features 745 * are defined so write 0. 746 */ 747 flags = cpu_to_be32(0); 748 r = qio_channel_write_all(QIO_CHANNEL(client->ioc), 749 (char *) &flags, sizeof(flags), NULL); 750 if (r < 0) { 751 goto out; 752 } 753 754 r = qio_channel_read_all(QIO_CHANNEL(client->ioc), 755 (char *) &flags, sizeof(flags), NULL); 756 if (be32_to_cpu(flags) != 0 || r < 0) { 757 goto out; 758 } 759 760 while (qatomic_read(&state) == RUNNING) { 761 PRHelperRequest req; 762 PRHelperResponse resp; 763 int sz; 764 765 sz = prh_read_request(client, &req, &resp, &local_err); 766 if (sz < 0) { 767 break; 768 } 769 770 num_active_sockets++; 771 if (req.cdb[0] == PERSISTENT_RESERVE_OUT) { 772 r = do_pr_out(req.fd, req.cdb, resp.sense, 773 client->data, sz); 774 resp.sz = 0; 775 } else { 776 resp.sz = sizeof(client->data); 777 r = do_pr_in(req.fd, req.cdb, resp.sense, 778 client->data, &resp.sz); 779 resp.sz = MIN(resp.sz, sz); 780 } 781 num_active_sockets--; 782 close(req.fd); 783 if (r == -1) { 784 break; 785 } 786 resp.result = r; 787 788 if (prh_write_response(client, &req, &resp, &local_err) < 0) { 789 break; 790 } 791 } 792 793 if (local_err) { 794 if (verbose == 0) { 795 error_free(local_err); 796 } else { 797 error_report_err(local_err); 798 } 799 } 800 801 out: 802 qio_channel_detach_aio_context(QIO_CHANNEL(client->ioc)); 803 object_unref(OBJECT(client->ioc)); 804 g_free(client); 805 } 806 807 static gboolean accept_client(QIOChannel *ioc, GIOCondition cond, gpointer opaque) 808 { 809 QIOChannelSocket *cioc; 810 PRHelperClient *prh; 811 812 cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc), 813 NULL); 814 if (!cioc) { 815 return TRUE; 816 } 817 818 prh = g_new(PRHelperClient, 1); 819 prh->ioc = cioc; 820 prh->fd = -1; 821 prh->co = qemu_coroutine_create(prh_co_entry, prh); 822 qemu_coroutine_enter(prh->co); 823 824 return TRUE; 825 } 826 827 static void termsig_handler(int signum) 828 { 829 qatomic_cmpxchg(&state, RUNNING, TERMINATE); 830 qemu_notify_event(); 831 } 832 833 static void close_server_socket(void) 834 { 835 assert(server_ioc); 836 837 g_source_remove(server_watch); 838 server_watch = -1; 839 object_unref(OBJECT(server_ioc)); 840 num_active_sockets--; 841 } 842 843 #ifdef CONFIG_LIBCAP_NG 844 static int drop_privileges(void) 845 { 846 /* clear all capabilities */ 847 capng_clear(CAPNG_SELECT_BOTH); 848 849 if (capng_update(CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED, 850 CAP_SYS_RAWIO) < 0) { 851 return -1; 852 } 853 854 #ifdef CONFIG_MPATH 855 /* For /dev/mapper/control ioctls */ 856 if (capng_update(CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED, 857 CAP_SYS_ADMIN) < 0) { 858 return -1; 859 } 860 #endif 861 862 /* Change user/group id, retaining the capabilities. Because file descriptors 863 * are passed via SCM_RIGHTS, we don't need supplementary groups (and in 864 * fact the helper can run as "nobody"). 865 */ 866 if (capng_change_id(uid != -1 ? uid : getuid(), 867 gid != -1 ? gid : getgid(), 868 CAPNG_DROP_SUPP_GRP | CAPNG_CLEAR_BOUNDING)) { 869 return -1; 870 } 871 872 return 0; 873 } 874 #endif 875 876 int main(int argc, char **argv) 877 { 878 const char *sopt = "hVk:f:dT:u:g:vq"; 879 struct option lopt[] = { 880 { "help", no_argument, NULL, 'h' }, 881 { "version", no_argument, NULL, 'V' }, 882 { "socket", required_argument, NULL, 'k' }, 883 { "pidfile", required_argument, NULL, 'f' }, 884 { "daemon", no_argument, NULL, 'd' }, 885 { "trace", required_argument, NULL, 'T' }, 886 { "user", required_argument, NULL, 'u' }, 887 { "group", required_argument, NULL, 'g' }, 888 { "verbose", no_argument, NULL, 'v' }, 889 { "quiet", no_argument, NULL, 'q' }, 890 { NULL, 0, NULL, 0 } 891 }; 892 int opt_ind = 0; 893 int loglevel = 1; 894 int quiet = 0; 895 int ch; 896 Error *local_err = NULL; 897 bool daemonize = false; 898 bool pidfile_specified = false; 899 bool socket_path_specified = false; 900 unsigned socket_activation; 901 902 struct sigaction sa_sigterm; 903 memset(&sa_sigterm, 0, sizeof(sa_sigterm)); 904 sa_sigterm.sa_handler = termsig_handler; 905 sigaction(SIGTERM, &sa_sigterm, NULL); 906 sigaction(SIGINT, &sa_sigterm, NULL); 907 sigaction(SIGHUP, &sa_sigterm, NULL); 908 909 signal(SIGPIPE, SIG_IGN); 910 911 error_init(argv[0]); 912 module_call_init(MODULE_INIT_TRACE); 913 module_call_init(MODULE_INIT_QOM); 914 qemu_add_opts(&qemu_trace_opts); 915 qemu_init_exec_dir(argv[0]); 916 917 compute_default_paths(); 918 919 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { 920 switch (ch) { 921 case 'k': 922 g_free(socket_path); 923 socket_path = g_strdup(optarg); 924 socket_path_specified = true; 925 if (socket_path[0] != '/') { 926 error_report("socket path must be absolute"); 927 exit(EXIT_FAILURE); 928 } 929 break; 930 case 'f': 931 g_free(pidfile); 932 pidfile = g_strdup(optarg); 933 pidfile_specified = true; 934 break; 935 #ifdef CONFIG_LIBCAP_NG 936 case 'u': { 937 unsigned long res; 938 struct passwd *userinfo = getpwnam(optarg); 939 if (userinfo) { 940 uid = userinfo->pw_uid; 941 } else if (qemu_strtoul(optarg, NULL, 10, &res) == 0 && 942 (uid_t)res == res) { 943 uid = res; 944 } else { 945 error_report("invalid user '%s'", optarg); 946 exit(EXIT_FAILURE); 947 } 948 break; 949 } 950 case 'g': { 951 unsigned long res; 952 struct group *groupinfo = getgrnam(optarg); 953 if (groupinfo) { 954 gid = groupinfo->gr_gid; 955 } else if (qemu_strtoul(optarg, NULL, 10, &res) == 0 && 956 (gid_t)res == res) { 957 gid = res; 958 } else { 959 error_report("invalid group '%s'", optarg); 960 exit(EXIT_FAILURE); 961 } 962 break; 963 } 964 #else 965 case 'u': 966 case 'g': 967 error_report("-%c not supported by this %s", ch, argv[0]); 968 exit(1); 969 #endif 970 case 'd': 971 daemonize = true; 972 break; 973 case 'q': 974 quiet = 1; 975 break; 976 case 'v': 977 ++loglevel; 978 break; 979 case 'T': 980 trace_opt_parse(optarg); 981 break; 982 case 'V': 983 version(argv[0]); 984 exit(EXIT_SUCCESS); 985 break; 986 case 'h': 987 usage(argv[0]); 988 exit(EXIT_SUCCESS); 989 break; 990 case '?': 991 error_report("Try `%s --help' for more information.", argv[0]); 992 exit(EXIT_FAILURE); 993 } 994 } 995 996 /* set verbosity */ 997 noisy = !quiet && (loglevel >= 3); 998 verbose = quiet ? 0 : MIN(loglevel, 3); 999 1000 if (!trace_init_backends()) { 1001 exit(EXIT_FAILURE); 1002 } 1003 trace_init_file(); 1004 qemu_set_log(LOG_TRACE); 1005 1006 #ifdef CONFIG_MPATH 1007 dm_init(); 1008 multipath_pr_init(); 1009 #endif 1010 1011 socket_activation = check_socket_activation(); 1012 if (socket_activation == 0) { 1013 SocketAddress saddr; 1014 saddr = (SocketAddress){ 1015 .type = SOCKET_ADDRESS_TYPE_UNIX, 1016 .u.q_unix.path = socket_path, 1017 }; 1018 server_ioc = qio_channel_socket_new(); 1019 if (qio_channel_socket_listen_sync(server_ioc, &saddr, 1020 1, &local_err) < 0) { 1021 object_unref(OBJECT(server_ioc)); 1022 error_report_err(local_err); 1023 return 1; 1024 } 1025 } else { 1026 /* Using socket activation - check user didn't use -p etc. */ 1027 if (socket_path_specified) { 1028 error_report("Unix socket can't be set when using socket activation"); 1029 exit(EXIT_FAILURE); 1030 } 1031 1032 /* Can only listen on a single socket. */ 1033 if (socket_activation > 1) { 1034 error_report("%s does not support socket activation with LISTEN_FDS > 1", 1035 argv[0]); 1036 exit(EXIT_FAILURE); 1037 } 1038 server_ioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD, 1039 &local_err); 1040 if (server_ioc == NULL) { 1041 error_reportf_err(local_err, 1042 "Failed to use socket activation: "); 1043 exit(EXIT_FAILURE); 1044 } 1045 } 1046 1047 qemu_init_main_loop(&error_fatal); 1048 1049 server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc), 1050 G_IO_IN, 1051 accept_client, 1052 NULL, NULL); 1053 1054 if (daemonize) { 1055 if (daemon(0, 0) < 0) { 1056 error_report("Failed to daemonize: %s", strerror(errno)); 1057 exit(EXIT_FAILURE); 1058 } 1059 } 1060 1061 if (daemonize || pidfile_specified) { 1062 qemu_write_pidfile(pidfile, &error_fatal); 1063 } 1064 1065 #ifdef CONFIG_LIBCAP_NG 1066 if (drop_privileges() < 0) { 1067 error_report("Failed to drop privileges: %s", strerror(errno)); 1068 exit(EXIT_FAILURE); 1069 } 1070 #endif 1071 1072 state = RUNNING; 1073 do { 1074 main_loop_wait(false); 1075 if (state == TERMINATE) { 1076 state = TERMINATING; 1077 close_server_socket(); 1078 } 1079 } while (num_active_sockets > 0); 1080 1081 exit(EXIT_SUCCESS); 1082 } 1083