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