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/help-texts.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 g_autofree char *state = qemu_get_local_state_dir(); 81 82 socket_path = g_build_filename(state, "run", "qemu-pr-helper.sock", NULL); 83 pidfile = g_build_filename(state, "run", "qemu-pr-helper.pid", NULL); 84 } 85 86 static void usage(const char *name) 87 { 88 (printf) ( 89 "Usage: %s [OPTIONS] FILE\n" 90 "Persistent Reservation helper program for QEMU\n" 91 "\n" 92 " -h, --help display this help and exit\n" 93 " -V, --version output version information and exit\n" 94 "\n" 95 " -d, --daemon run in the background\n" 96 " -f, --pidfile=PATH PID file when running as a daemon\n" 97 " (default '%s')\n" 98 " -k, --socket=PATH path to the unix socket\n" 99 " (default '%s')\n" 100 " -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n" 101 " specify tracing options\n" 102 #ifdef CONFIG_LIBCAP_NG 103 " -u, --user=USER user to drop privileges to\n" 104 " -g, --group=GROUP group to drop privileges to\n" 105 #endif 106 "\n" 107 QEMU_HELP_BOTTOM "\n" 108 , name, pidfile, socket_path); 109 } 110 111 static void version(const char *name) 112 { 113 printf( 114 "%s " QEMU_FULL_VERSION "\n" 115 "Written by Paolo Bonzini.\n" 116 "\n" 117 QEMU_COPYRIGHT "\n" 118 "This is free software; see the source for copying conditions. There is NO\n" 119 "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n" 120 , name); 121 } 122 123 /* SG_IO support */ 124 125 typedef struct PRHelperSGIOData { 126 int fd; 127 const uint8_t *cdb; 128 uint8_t *sense; 129 uint8_t *buf; 130 int sz; /* input/output */ 131 int dir; 132 } PRHelperSGIOData; 133 134 static int do_sgio_worker(void *opaque) 135 { 136 PRHelperSGIOData *data = opaque; 137 struct sg_io_hdr io_hdr; 138 int ret; 139 int status; 140 SCSISense sense_code; 141 142 memset(data->sense, 0, PR_HELPER_SENSE_SIZE); 143 memset(&io_hdr, 0, sizeof(io_hdr)); 144 io_hdr.interface_id = 'S'; 145 io_hdr.cmd_len = PR_HELPER_CDB_SIZE; 146 io_hdr.cmdp = (uint8_t *)data->cdb; 147 io_hdr.sbp = data->sense; 148 io_hdr.mx_sb_len = PR_HELPER_SENSE_SIZE; 149 io_hdr.timeout = 1; 150 io_hdr.dxfer_direction = data->dir; 151 io_hdr.dxferp = (char *)data->buf; 152 io_hdr.dxfer_len = data->sz; 153 ret = ioctl(data->fd, SG_IO, &io_hdr); 154 155 if (ret < 0) { 156 status = scsi_sense_from_errno(errno, &sense_code); 157 if (status == CHECK_CONDITION) { 158 scsi_build_sense(data->sense, sense_code); 159 } 160 } else if (io_hdr.host_status != SCSI_HOST_OK) { 161 status = scsi_sense_from_host_status(io_hdr.host_status, &sense_code); 162 if (status == CHECK_CONDITION) { 163 scsi_build_sense(data->sense, sense_code); 164 } 165 } else if (io_hdr.driver_status & SG_ERR_DRIVER_TIMEOUT) { 166 status = BUSY; 167 } else { 168 status = io_hdr.status; 169 } 170 171 if (status == GOOD) { 172 data->sz -= io_hdr.resid; 173 } else { 174 data->sz = 0; 175 } 176 177 return status; 178 } 179 180 static int do_sgio(int fd, const uint8_t *cdb, uint8_t *sense, 181 uint8_t *buf, int *sz, int dir) 182 { 183 ThreadPool *pool = aio_get_thread_pool(qemu_get_aio_context()); 184 int r; 185 186 PRHelperSGIOData data = { 187 .fd = fd, 188 .cdb = cdb, 189 .sense = sense, 190 .buf = buf, 191 .sz = *sz, 192 .dir = dir, 193 }; 194 195 r = thread_pool_submit_co(pool, do_sgio_worker, &data); 196 *sz = data.sz; 197 return r; 198 } 199 200 /* Device mapper interface */ 201 202 #ifdef CONFIG_MPATH 203 #define CONTROL_PATH "/dev/mapper/control" 204 205 typedef struct DMData { 206 struct dm_ioctl dm; 207 uint8_t data[1024]; 208 } DMData; 209 210 static int control_fd; 211 212 static void *dm_ioctl(int ioc, struct dm_ioctl *dm) 213 { 214 static DMData d; 215 memcpy(&d.dm, dm, sizeof(d.dm)); 216 QEMU_BUILD_BUG_ON(sizeof(d.data) < sizeof(struct dm_target_spec)); 217 218 d.dm.version[0] = DM_VERSION_MAJOR; 219 d.dm.version[1] = 0; 220 d.dm.version[2] = 0; 221 d.dm.data_size = 1024; 222 d.dm.data_start = offsetof(DMData, data); 223 if (ioctl(control_fd, ioc, &d) < 0) { 224 return NULL; 225 } 226 memcpy(dm, &d.dm, sizeof(d.dm)); 227 return &d.data; 228 } 229 230 static void *dm_dev_ioctl(int fd, int ioc, struct dm_ioctl *dm) 231 { 232 struct stat st; 233 int r; 234 235 r = fstat(fd, &st); 236 if (r < 0) { 237 perror("fstat"); 238 exit(1); 239 } 240 241 dm->dev = st.st_rdev; 242 return dm_ioctl(ioc, dm); 243 } 244 245 static void dm_init(void) 246 { 247 control_fd = open(CONTROL_PATH, O_RDWR); 248 if (control_fd < 0) { 249 perror("Cannot open " CONTROL_PATH); 250 exit(1); 251 } 252 struct dm_ioctl dm = { }; 253 if (!dm_ioctl(DM_VERSION, &dm)) { 254 perror("ioctl"); 255 exit(1); 256 } 257 if (dm.version[0] != DM_VERSION_MAJOR) { 258 fprintf(stderr, "Unsupported device mapper interface"); 259 exit(1); 260 } 261 } 262 263 /* Variables required by libmultipath and libmpathpersist. */ 264 QEMU_BUILD_BUG_ON(PR_HELPER_DATA_SIZE > MPATH_MAX_PARAM_LEN); 265 static struct config *multipath_conf; 266 unsigned mpath_mx_alloc_len = PR_HELPER_DATA_SIZE; 267 int logsink; 268 struct udev *udev; 269 270 extern struct config *get_multipath_config(void); 271 struct config *get_multipath_config(void) 272 { 273 return multipath_conf; 274 } 275 276 extern void put_multipath_config(struct config *conf); 277 void put_multipath_config(struct config *conf) 278 { 279 } 280 281 static void multipath_pr_init(void) 282 { 283 udev = udev_new(); 284 #ifdef CONFIG_MPATH_NEW_API 285 multipath_conf = mpath_lib_init(); 286 #else 287 mpath_lib_init(udev); 288 #endif 289 } 290 291 static int is_mpath(int fd) 292 { 293 struct dm_ioctl dm = { .flags = DM_NOFLUSH_FLAG }; 294 struct dm_target_spec *tgt; 295 296 tgt = dm_dev_ioctl(fd, DM_TABLE_STATUS, &dm); 297 if (!tgt) { 298 if (errno == ENXIO) { 299 return 0; 300 } 301 perror("ioctl"); 302 exit(EXIT_FAILURE); 303 } 304 return !strncmp(tgt->target_type, "multipath", DM_MAX_TYPE_NAME); 305 } 306 307 static SCSISense mpath_generic_sense(int r) 308 { 309 switch (r) { 310 case MPATH_PR_SENSE_NOT_READY: 311 return SENSE_CODE(NOT_READY); 312 case MPATH_PR_SENSE_MEDIUM_ERROR: 313 return SENSE_CODE(READ_ERROR); 314 case MPATH_PR_SENSE_HARDWARE_ERROR: 315 return SENSE_CODE(TARGET_FAILURE); 316 case MPATH_PR_SENSE_ABORTED_COMMAND: 317 return SENSE_CODE(IO_ERROR); 318 default: 319 abort(); 320 } 321 } 322 323 static int mpath_reconstruct_sense(int fd, int r, uint8_t *sense) 324 { 325 switch (r) { 326 case MPATH_PR_SUCCESS: 327 return GOOD; 328 case MPATH_PR_SENSE_NOT_READY: 329 case MPATH_PR_SENSE_MEDIUM_ERROR: 330 case MPATH_PR_SENSE_HARDWARE_ERROR: 331 case MPATH_PR_SENSE_ABORTED_COMMAND: 332 { 333 /* libmpathpersist ate the exact sense. Try to find it by 334 * issuing TEST UNIT READY. 335 */ 336 uint8_t cdb[6] = { TEST_UNIT_READY }; 337 int sz = 0; 338 int ret = do_sgio(fd, cdb, sense, NULL, &sz, SG_DXFER_NONE); 339 340 if (ret != GOOD) { 341 return ret; 342 } 343 scsi_build_sense(sense, mpath_generic_sense(r)); 344 return CHECK_CONDITION; 345 } 346 347 case MPATH_PR_SENSE_UNIT_ATTENTION: 348 /* Congratulations libmpathpersist, you ruined the Unit Attention... 349 * Return a heavyweight one. 350 */ 351 scsi_build_sense(sense, SENSE_CODE(SCSI_BUS_RESET)); 352 return CHECK_CONDITION; 353 case MPATH_PR_SENSE_INVALID_OP: 354 /* Only one valid sense. */ 355 scsi_build_sense(sense, SENSE_CODE(INVALID_OPCODE)); 356 return CHECK_CONDITION; 357 case MPATH_PR_ILLEGAL_REQ: 358 /* Guess. */ 359 scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM)); 360 return CHECK_CONDITION; 361 case MPATH_PR_NO_SENSE: 362 scsi_build_sense(sense, SENSE_CODE(NO_SENSE)); 363 return CHECK_CONDITION; 364 365 case MPATH_PR_RESERV_CONFLICT: 366 return RESERVATION_CONFLICT; 367 368 case MPATH_PR_OTHER: 369 default: 370 scsi_build_sense(sense, SENSE_CODE(LUN_COMM_FAILURE)); 371 return CHECK_CONDITION; 372 } 373 } 374 375 static int multipath_pr_in(int fd, const uint8_t *cdb, uint8_t *sense, 376 uint8_t *data, int sz) 377 { 378 int rq_servact = cdb[1]; 379 struct prin_resp resp; 380 size_t written; 381 int r; 382 383 switch (rq_servact) { 384 case MPATH_PRIN_RKEY_SA: 385 case MPATH_PRIN_RRES_SA: 386 case MPATH_PRIN_RCAP_SA: 387 break; 388 case MPATH_PRIN_RFSTAT_SA: 389 /* Nobody implements it anyway, so bail out. */ 390 default: 391 /* Cannot parse any other output. */ 392 scsi_build_sense(sense, SENSE_CODE(INVALID_FIELD)); 393 return CHECK_CONDITION; 394 } 395 396 r = mpath_persistent_reserve_in(fd, rq_servact, &resp, noisy, verbose); 397 if (r == MPATH_PR_SUCCESS) { 398 switch (rq_servact) { 399 case MPATH_PRIN_RKEY_SA: 400 case MPATH_PRIN_RRES_SA: { 401 struct prin_readdescr *out = &resp.prin_descriptor.prin_readkeys; 402 assert(sz >= 8); 403 written = MIN(out->additional_length + 8, sz); 404 stl_be_p(&data[0], out->prgeneration); 405 stl_be_p(&data[4], out->additional_length); 406 memcpy(&data[8], out->key_list, written - 8); 407 break; 408 } 409 case MPATH_PRIN_RCAP_SA: { 410 struct prin_capdescr *out = &resp.prin_descriptor.prin_readcap; 411 assert(sz >= 6); 412 written = 6; 413 stw_be_p(&data[0], out->length); 414 data[2] = out->flags[0]; 415 data[3] = out->flags[1]; 416 stw_be_p(&data[4], out->pr_type_mask); 417 break; 418 } 419 default: 420 scsi_build_sense(sense, SENSE_CODE(INVALID_OPCODE)); 421 return CHECK_CONDITION; 422 } 423 assert(written <= sz); 424 memset(data + written, 0, sz - written); 425 } 426 427 return mpath_reconstruct_sense(fd, r, sense); 428 } 429 430 static int multipath_pr_out(int fd, const uint8_t *cdb, uint8_t *sense, 431 const uint8_t *param, int sz) 432 { 433 int rq_servact = cdb[1]; 434 int rq_scope = cdb[2] >> 4; 435 int rq_type = cdb[2] & 0xf; 436 g_autofree struct prout_param_descriptor *paramp = NULL; 437 char transportids[PR_HELPER_DATA_SIZE]; 438 int r; 439 440 paramp = g_malloc0(sizeof(struct prout_param_descriptor) 441 + sizeof(struct transportid *) * MPATH_MX_TIDS); 442 443 if (sz < PR_OUT_FIXED_PARAM_SIZE) { 444 /* Illegal request, Parameter list length error. This isn't fatal; 445 * we have read the data, send an error without closing the socket. 446 */ 447 scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM_LEN)); 448 return CHECK_CONDITION; 449 } 450 451 switch (rq_servact) { 452 case MPATH_PROUT_REG_SA: 453 case MPATH_PROUT_RES_SA: 454 case MPATH_PROUT_REL_SA: 455 case MPATH_PROUT_CLEAR_SA: 456 case MPATH_PROUT_PREE_SA: 457 case MPATH_PROUT_PREE_AB_SA: 458 case MPATH_PROUT_REG_IGN_SA: 459 break; 460 case MPATH_PROUT_REG_MOV_SA: 461 /* Not supported by struct prout_param_descriptor. */ 462 default: 463 /* Cannot parse any other input. */ 464 scsi_build_sense(sense, SENSE_CODE(INVALID_FIELD)); 465 return CHECK_CONDITION; 466 } 467 468 /* Convert input data, especially transport IDs, to the structs 469 * used by libmpathpersist (which, of course, will immediately 470 * do the opposite). 471 */ 472 memcpy(¶mp->key, ¶m[0], 8); 473 memcpy(¶mp->sa_key, ¶m[8], 8); 474 paramp->sa_flags = param[20]; 475 if (sz > PR_OUT_FIXED_PARAM_SIZE) { 476 size_t transportid_len; 477 int i, j; 478 if (sz < PR_OUT_FIXED_PARAM_SIZE + 4) { 479 scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM_LEN)); 480 return CHECK_CONDITION; 481 } 482 transportid_len = ldl_be_p(¶m[24]) + PR_OUT_FIXED_PARAM_SIZE + 4; 483 if (transportid_len > sz) { 484 scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM)); 485 return CHECK_CONDITION; 486 } 487 for (i = PR_OUT_FIXED_PARAM_SIZE + 4, j = 0; i < transportid_len; ) { 488 struct transportid *id = (struct transportid *) &transportids[j]; 489 int len; 490 491 id->format_code = param[i] & 0xc0; 492 id->protocol_id = param[i] & 0x0f; 493 switch (param[i] & 0xcf) { 494 case 0: 495 /* FC transport. */ 496 if (i + 24 > transportid_len) { 497 goto illegal_req; 498 } 499 memcpy(id->n_port_name, ¶m[i + 8], 8); 500 j += offsetof(struct transportid, n_port_name[8]); 501 i += 24; 502 break; 503 case 5: 504 case 0x45: 505 /* iSCSI transport. */ 506 len = lduw_be_p(¶m[i + 2]); 507 if (len > 252 || (len & 3) || i + len + 4 > transportid_len) { 508 /* For format code 00, the standard says the maximum is 223 509 * plus the NUL terminator. For format code 01 there is no 510 * maximum length, but libmpathpersist ignores the first 511 * byte of id->iscsi_name so our maximum is 252. 512 */ 513 goto illegal_req; 514 } 515 if (memchr(¶m[i + 4], 0, len) == NULL) { 516 goto illegal_req; 517 } 518 memcpy(id->iscsi_name, ¶m[i + 2], len + 2); 519 j += offsetof(struct transportid, iscsi_name[len + 2]); 520 i += len + 4; 521 break; 522 case 6: 523 /* SAS transport. */ 524 if (i + 24 > transportid_len) { 525 goto illegal_req; 526 } 527 memcpy(id->sas_address, ¶m[i + 4], 8); 528 j += offsetof(struct transportid, sas_address[8]); 529 i += 24; 530 break; 531 default: 532 illegal_req: 533 scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM)); 534 return CHECK_CONDITION; 535 } 536 537 assert(paramp->num_transportid < MPATH_MX_TIDS); 538 paramp->trnptid_list[paramp->num_transportid++] = id; 539 } 540 } 541 542 r = mpath_persistent_reserve_out(fd, rq_servact, rq_scope, rq_type, 543 paramp, noisy, verbose); 544 return mpath_reconstruct_sense(fd, r, sense); 545 } 546 #endif 547 548 static int do_pr_in(int fd, const uint8_t *cdb, uint8_t *sense, 549 uint8_t *data, int *resp_sz) 550 { 551 #ifdef CONFIG_MPATH 552 if (is_mpath(fd)) { 553 /* multipath_pr_in fills the whole input buffer. */ 554 int r = multipath_pr_in(fd, cdb, sense, data, *resp_sz); 555 if (r != GOOD) { 556 *resp_sz = 0; 557 } 558 return r; 559 } 560 #endif 561 562 return do_sgio(fd, cdb, sense, data, resp_sz, 563 SG_DXFER_FROM_DEV); 564 } 565 566 static int do_pr_out(int fd, const uint8_t *cdb, uint8_t *sense, 567 const uint8_t *param, int sz) 568 { 569 int resp_sz; 570 571 if ((fcntl(fd, F_GETFL) & O_ACCMODE) == O_RDONLY) { 572 scsi_build_sense(sense, SENSE_CODE(INVALID_OPCODE)); 573 return CHECK_CONDITION; 574 } 575 576 #ifdef CONFIG_MPATH 577 if (is_mpath(fd)) { 578 return multipath_pr_out(fd, cdb, sense, param, sz); 579 } 580 #endif 581 582 resp_sz = sz; 583 return do_sgio(fd, cdb, sense, (uint8_t *)param, &resp_sz, 584 SG_DXFER_TO_DEV); 585 } 586 587 /* Client */ 588 589 typedef struct PRHelperClient { 590 QIOChannelSocket *ioc; 591 Coroutine *co; 592 int fd; 593 uint8_t data[PR_HELPER_DATA_SIZE]; 594 } PRHelperClient; 595 596 typedef struct PRHelperRequest { 597 int fd; 598 size_t sz; 599 uint8_t cdb[PR_HELPER_CDB_SIZE]; 600 } PRHelperRequest; 601 602 static int coroutine_fn prh_read(PRHelperClient *client, void *buf, int sz, 603 Error **errp) 604 { 605 int ret = 0; 606 607 while (sz > 0) { 608 int *fds = NULL; 609 size_t nfds = 0; 610 int i; 611 struct iovec iov; 612 ssize_t n_read; 613 614 iov.iov_base = buf; 615 iov.iov_len = sz; 616 n_read = qio_channel_readv_full(QIO_CHANNEL(client->ioc), &iov, 1, 617 &fds, &nfds, errp); 618 619 if (n_read == QIO_CHANNEL_ERR_BLOCK) { 620 qio_channel_yield(QIO_CHANNEL(client->ioc), G_IO_IN); 621 continue; 622 } 623 if (n_read <= 0) { 624 ret = n_read ? n_read : -1; 625 goto err; 626 } 627 628 /* Stash one file descriptor per request. */ 629 if (nfds) { 630 bool too_many = false; 631 for (i = 0; i < nfds; i++) { 632 if (client->fd == -1) { 633 client->fd = fds[i]; 634 } else { 635 close(fds[i]); 636 too_many = true; 637 } 638 } 639 g_free(fds); 640 if (too_many) { 641 ret = -1; 642 goto err; 643 } 644 } 645 646 buf += n_read; 647 sz -= n_read; 648 } 649 650 return 0; 651 652 err: 653 if (client->fd != -1) { 654 close(client->fd); 655 client->fd = -1; 656 } 657 return ret; 658 } 659 660 static int coroutine_fn prh_read_request(PRHelperClient *client, 661 PRHelperRequest *req, 662 PRHelperResponse *resp, Error **errp) 663 { 664 uint32_t sz; 665 666 if (prh_read(client, req->cdb, sizeof(req->cdb), NULL) < 0) { 667 return -1; 668 } 669 670 if (client->fd == -1) { 671 error_setg(errp, "No file descriptor in request."); 672 return -1; 673 } 674 675 if (req->cdb[0] != PERSISTENT_RESERVE_OUT && 676 req->cdb[0] != PERSISTENT_RESERVE_IN) { 677 error_setg(errp, "Invalid CDB, closing socket."); 678 goto out_close; 679 } 680 681 sz = scsi_cdb_xfer(req->cdb); 682 if (sz > sizeof(client->data)) { 683 goto out_close; 684 } 685 686 if (req->cdb[0] == PERSISTENT_RESERVE_OUT) { 687 if (qio_channel_read_all(QIO_CHANNEL(client->ioc), 688 (char *)client->data, sz, 689 errp) < 0) { 690 goto out_close; 691 } 692 } 693 694 req->fd = client->fd; 695 req->sz = sz; 696 client->fd = -1; 697 return sz; 698 699 out_close: 700 close(client->fd); 701 client->fd = -1; 702 return -1; 703 } 704 705 static int coroutine_fn prh_write_response(PRHelperClient *client, 706 PRHelperRequest *req, 707 PRHelperResponse *resp, Error **errp) 708 { 709 ssize_t r; 710 size_t sz; 711 712 if (req->cdb[0] == PERSISTENT_RESERVE_IN && resp->result == GOOD) { 713 assert(resp->sz <= req->sz && resp->sz <= sizeof(client->data)); 714 } else { 715 assert(resp->sz == 0); 716 } 717 718 sz = resp->sz; 719 720 resp->result = cpu_to_be32(resp->result); 721 resp->sz = cpu_to_be32(resp->sz); 722 r = qio_channel_write_all(QIO_CHANNEL(client->ioc), 723 (char *) resp, sizeof(*resp), errp); 724 if (r < 0) { 725 return r; 726 } 727 728 r = qio_channel_write_all(QIO_CHANNEL(client->ioc), 729 (char *) client->data, 730 sz, errp); 731 return r < 0 ? r : 0; 732 } 733 734 static void coroutine_fn prh_co_entry(void *opaque) 735 { 736 PRHelperClient *client = opaque; 737 Error *local_err = NULL; 738 uint32_t flags; 739 int r; 740 741 qio_channel_set_blocking(QIO_CHANNEL(client->ioc), 742 false, NULL); 743 qio_channel_attach_aio_context(QIO_CHANNEL(client->ioc), 744 qemu_get_aio_context()); 745 746 /* A very simple negotiation for future extensibility. No features 747 * are defined so write 0. 748 */ 749 flags = cpu_to_be32(0); 750 r = qio_channel_write_all(QIO_CHANNEL(client->ioc), 751 (char *) &flags, sizeof(flags), NULL); 752 if (r < 0) { 753 goto out; 754 } 755 756 r = qio_channel_read_all(QIO_CHANNEL(client->ioc), 757 (char *) &flags, sizeof(flags), NULL); 758 if (be32_to_cpu(flags) != 0 || r < 0) { 759 goto out; 760 } 761 762 while (qatomic_read(&state) == RUNNING) { 763 PRHelperRequest req; 764 PRHelperResponse resp; 765 int sz; 766 767 sz = prh_read_request(client, &req, &resp, &local_err); 768 if (sz < 0) { 769 break; 770 } 771 772 num_active_sockets++; 773 if (req.cdb[0] == PERSISTENT_RESERVE_OUT) { 774 r = do_pr_out(req.fd, req.cdb, resp.sense, 775 client->data, sz); 776 resp.sz = 0; 777 } else { 778 resp.sz = sizeof(client->data); 779 r = do_pr_in(req.fd, req.cdb, resp.sense, 780 client->data, &resp.sz); 781 resp.sz = MIN(resp.sz, sz); 782 } 783 num_active_sockets--; 784 close(req.fd); 785 if (r == -1) { 786 break; 787 } 788 resp.result = r; 789 790 if (prh_write_response(client, &req, &resp, &local_err) < 0) { 791 break; 792 } 793 } 794 795 if (local_err) { 796 if (verbose == 0) { 797 error_free(local_err); 798 } else { 799 error_report_err(local_err); 800 } 801 } 802 803 out: 804 qio_channel_detach_aio_context(QIO_CHANNEL(client->ioc)); 805 object_unref(OBJECT(client->ioc)); 806 g_free(client); 807 } 808 809 static gboolean accept_client(QIOChannel *ioc, GIOCondition cond, gpointer opaque) 810 { 811 QIOChannelSocket *cioc; 812 PRHelperClient *prh; 813 814 cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc), 815 NULL); 816 if (!cioc) { 817 return TRUE; 818 } 819 820 prh = g_new(PRHelperClient, 1); 821 prh->ioc = cioc; 822 prh->fd = -1; 823 prh->co = qemu_coroutine_create(prh_co_entry, prh); 824 qemu_coroutine_enter(prh->co); 825 826 return TRUE; 827 } 828 829 static void termsig_handler(int signum) 830 { 831 qatomic_cmpxchg(&state, RUNNING, TERMINATE); 832 qemu_notify_event(); 833 } 834 835 static void close_server_socket(void) 836 { 837 assert(server_ioc); 838 839 g_source_remove(server_watch); 840 server_watch = -1; 841 object_unref(OBJECT(server_ioc)); 842 num_active_sockets--; 843 } 844 845 #ifdef CONFIG_LIBCAP_NG 846 static int drop_privileges(void) 847 { 848 /* clear all capabilities */ 849 capng_clear(CAPNG_SELECT_BOTH); 850 851 if (capng_update(CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED, 852 CAP_SYS_RAWIO) < 0) { 853 return -1; 854 } 855 856 #ifdef CONFIG_MPATH 857 /* For /dev/mapper/control ioctls */ 858 if (capng_update(CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED, 859 CAP_SYS_ADMIN) < 0) { 860 return -1; 861 } 862 #endif 863 864 /* Change user/group id, retaining the capabilities. Because file descriptors 865 * are passed via SCM_RIGHTS, we don't need supplementary groups (and in 866 * fact the helper can run as "nobody"). 867 */ 868 if (capng_change_id(uid != -1 ? uid : getuid(), 869 gid != -1 ? gid : getgid(), 870 CAPNG_DROP_SUPP_GRP | CAPNG_CLEAR_BOUNDING)) { 871 return -1; 872 } 873 874 return 0; 875 } 876 #endif 877 878 int main(int argc, char **argv) 879 { 880 const char *sopt = "hVk:f:dT:u:g:vq"; 881 struct option lopt[] = { 882 { "help", no_argument, NULL, 'h' }, 883 { "version", no_argument, NULL, 'V' }, 884 { "socket", required_argument, NULL, 'k' }, 885 { "pidfile", required_argument, NULL, 'f' }, 886 { "daemon", no_argument, NULL, 'd' }, 887 { "trace", required_argument, NULL, 'T' }, 888 { "user", required_argument, NULL, 'u' }, 889 { "group", required_argument, NULL, 'g' }, 890 { "verbose", no_argument, NULL, 'v' }, 891 { "quiet", no_argument, NULL, 'q' }, 892 { NULL, 0, NULL, 0 } 893 }; 894 int opt_ind = 0; 895 int loglevel = 1; 896 int quiet = 0; 897 int ch; 898 Error *local_err = NULL; 899 bool daemonize = false; 900 bool pidfile_specified = false; 901 bool socket_path_specified = false; 902 unsigned socket_activation; 903 904 struct sigaction sa_sigterm; 905 memset(&sa_sigterm, 0, sizeof(sa_sigterm)); 906 sa_sigterm.sa_handler = termsig_handler; 907 sigaction(SIGTERM, &sa_sigterm, NULL); 908 sigaction(SIGINT, &sa_sigterm, NULL); 909 sigaction(SIGHUP, &sa_sigterm, NULL); 910 911 signal(SIGPIPE, SIG_IGN); 912 913 error_init(argv[0]); 914 module_call_init(MODULE_INIT_TRACE); 915 module_call_init(MODULE_INIT_QOM); 916 qemu_add_opts(&qemu_trace_opts); 917 qemu_init_exec_dir(argv[0]); 918 919 compute_default_paths(); 920 921 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { 922 switch (ch) { 923 case 'k': 924 g_free(socket_path); 925 socket_path = g_strdup(optarg); 926 socket_path_specified = true; 927 if (socket_path[0] != '/') { 928 error_report("socket path must be absolute"); 929 exit(EXIT_FAILURE); 930 } 931 break; 932 case 'f': 933 g_free(pidfile); 934 pidfile = g_strdup(optarg); 935 pidfile_specified = true; 936 break; 937 #ifdef CONFIG_LIBCAP_NG 938 case 'u': { 939 unsigned long res; 940 struct passwd *userinfo = getpwnam(optarg); 941 if (userinfo) { 942 uid = userinfo->pw_uid; 943 } else if (qemu_strtoul(optarg, NULL, 10, &res) == 0 && 944 (uid_t)res == res) { 945 uid = res; 946 } else { 947 error_report("invalid user '%s'", optarg); 948 exit(EXIT_FAILURE); 949 } 950 break; 951 } 952 case 'g': { 953 unsigned long res; 954 struct group *groupinfo = getgrnam(optarg); 955 if (groupinfo) { 956 gid = groupinfo->gr_gid; 957 } else if (qemu_strtoul(optarg, NULL, 10, &res) == 0 && 958 (gid_t)res == res) { 959 gid = res; 960 } else { 961 error_report("invalid group '%s'", optarg); 962 exit(EXIT_FAILURE); 963 } 964 break; 965 } 966 #else 967 case 'u': 968 case 'g': 969 error_report("-%c not supported by this %s", ch, argv[0]); 970 exit(1); 971 #endif 972 case 'd': 973 daemonize = true; 974 break; 975 case 'q': 976 quiet = 1; 977 break; 978 case 'v': 979 ++loglevel; 980 break; 981 case 'T': 982 trace_opt_parse(optarg); 983 break; 984 case 'V': 985 version(argv[0]); 986 exit(EXIT_SUCCESS); 987 break; 988 case 'h': 989 usage(argv[0]); 990 exit(EXIT_SUCCESS); 991 break; 992 case '?': 993 error_report("Try `%s --help' for more information.", argv[0]); 994 exit(EXIT_FAILURE); 995 } 996 } 997 998 /* set verbosity */ 999 noisy = !quiet && (loglevel >= 3); 1000 verbose = quiet ? 0 : MIN(loglevel, 3); 1001 1002 if (!trace_init_backends()) { 1003 exit(EXIT_FAILURE); 1004 } 1005 trace_init_file(); 1006 qemu_set_log(LOG_TRACE, &error_fatal); 1007 1008 #ifdef CONFIG_MPATH 1009 dm_init(); 1010 multipath_pr_init(); 1011 #endif 1012 1013 socket_activation = check_socket_activation(); 1014 if (socket_activation == 0) { 1015 SocketAddress saddr; 1016 saddr = (SocketAddress){ 1017 .type = SOCKET_ADDRESS_TYPE_UNIX, 1018 .u.q_unix.path = socket_path, 1019 }; 1020 server_ioc = qio_channel_socket_new(); 1021 if (qio_channel_socket_listen_sync(server_ioc, &saddr, 1022 1, &local_err) < 0) { 1023 object_unref(OBJECT(server_ioc)); 1024 error_report_err(local_err); 1025 return 1; 1026 } 1027 } else { 1028 /* Using socket activation - check user didn't use -p etc. */ 1029 if (socket_path_specified) { 1030 error_report("Unix socket can't be set when using socket activation"); 1031 exit(EXIT_FAILURE); 1032 } 1033 1034 /* Can only listen on a single socket. */ 1035 if (socket_activation > 1) { 1036 error_report("%s does not support socket activation with LISTEN_FDS > 1", 1037 argv[0]); 1038 exit(EXIT_FAILURE); 1039 } 1040 server_ioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD, 1041 &local_err); 1042 if (server_ioc == NULL) { 1043 error_reportf_err(local_err, 1044 "Failed to use socket activation: "); 1045 exit(EXIT_FAILURE); 1046 } 1047 } 1048 1049 qemu_init_main_loop(&error_fatal); 1050 1051 server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc), 1052 G_IO_IN, 1053 accept_client, 1054 NULL, NULL); 1055 1056 if (daemonize) { 1057 if (daemon(0, 0) < 0) { 1058 error_report("Failed to daemonize: %s", strerror(errno)); 1059 exit(EXIT_FAILURE); 1060 } 1061 } 1062 1063 if (daemonize || pidfile_specified) { 1064 qemu_write_pidfile(pidfile, &error_fatal); 1065 } 1066 1067 #ifdef CONFIG_LIBCAP_NG 1068 if (drop_privileges() < 0) { 1069 error_report("Failed to drop privileges: %s", strerror(errno)); 1070 exit(EXIT_FAILURE); 1071 } 1072 #endif 1073 1074 state = RUNNING; 1075 do { 1076 main_loop_wait(false); 1077 if (state == TERMINATE) { 1078 state = TERMINATING; 1079 close_server_socket(); 1080 } 1081 } while (num_active_sockets > 0); 1082 1083 exit(EXIT_SUCCESS); 1084 } 1085