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