1 /* 2 * QEMU Block driver for CURL images 3 * 4 * Copyright (c) 2009 Alexander Graf <agraf@suse.de> 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 #include "qemu-common.h" 25 #include "block/block_int.h" 26 #include <curl/curl.h> 27 28 // #define DEBUG 29 // #define DEBUG_VERBOSE 30 31 #ifdef DEBUG_CURL 32 #define DPRINTF(fmt, ...) do { printf(fmt, ## __VA_ARGS__); } while (0) 33 #else 34 #define DPRINTF(fmt, ...) do { } while (0) 35 #endif 36 37 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \ 38 CURLPROTO_FTP | CURLPROTO_FTPS | \ 39 CURLPROTO_TFTP) 40 41 #define CURL_NUM_STATES 8 42 #define CURL_NUM_ACB 8 43 #define SECTOR_SIZE 512 44 #define READ_AHEAD_SIZE (256 * 1024) 45 46 #define FIND_RET_NONE 0 47 #define FIND_RET_OK 1 48 #define FIND_RET_WAIT 2 49 50 struct BDRVCURLState; 51 52 typedef struct CURLAIOCB { 53 BlockDriverAIOCB common; 54 QEMUBH *bh; 55 QEMUIOVector *qiov; 56 57 int64_t sector_num; 58 int nb_sectors; 59 60 size_t start; 61 size_t end; 62 } CURLAIOCB; 63 64 typedef struct CURLState 65 { 66 struct BDRVCURLState *s; 67 CURLAIOCB *acb[CURL_NUM_ACB]; 68 CURL *curl; 69 char *orig_buf; 70 size_t buf_start; 71 size_t buf_off; 72 size_t buf_len; 73 char range[128]; 74 char errmsg[CURL_ERROR_SIZE]; 75 char in_use; 76 } CURLState; 77 78 typedef struct BDRVCURLState { 79 CURLM *multi; 80 size_t len; 81 CURLState states[CURL_NUM_STATES]; 82 char *url; 83 size_t readahead_size; 84 } BDRVCURLState; 85 86 static void curl_clean_state(CURLState *s); 87 static void curl_multi_do(void *arg); 88 static int curl_aio_flush(void *opaque); 89 90 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action, 91 void *s, void *sp) 92 { 93 DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, fd); 94 switch (action) { 95 case CURL_POLL_IN: 96 qemu_aio_set_fd_handler(fd, curl_multi_do, NULL, curl_aio_flush, s); 97 break; 98 case CURL_POLL_OUT: 99 qemu_aio_set_fd_handler(fd, NULL, curl_multi_do, curl_aio_flush, s); 100 break; 101 case CURL_POLL_INOUT: 102 qemu_aio_set_fd_handler(fd, curl_multi_do, curl_multi_do, 103 curl_aio_flush, s); 104 break; 105 case CURL_POLL_REMOVE: 106 qemu_aio_set_fd_handler(fd, NULL, NULL, NULL, NULL); 107 break; 108 } 109 110 return 0; 111 } 112 113 static size_t curl_size_cb(void *ptr, size_t size, size_t nmemb, void *opaque) 114 { 115 CURLState *s = ((CURLState*)opaque); 116 size_t realsize = size * nmemb; 117 size_t fsize; 118 119 if(sscanf(ptr, "Content-Length: %zd", &fsize) == 1) { 120 s->s->len = fsize; 121 } 122 123 return realsize; 124 } 125 126 static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque) 127 { 128 CURLState *s = ((CURLState*)opaque); 129 size_t realsize = size * nmemb; 130 int i; 131 132 DPRINTF("CURL: Just reading %zd bytes\n", realsize); 133 134 if (!s || !s->orig_buf) 135 goto read_end; 136 137 memcpy(s->orig_buf + s->buf_off, ptr, realsize); 138 s->buf_off += realsize; 139 140 for(i=0; i<CURL_NUM_ACB; i++) { 141 CURLAIOCB *acb = s->acb[i]; 142 143 if (!acb) 144 continue; 145 146 if ((s->buf_off >= acb->end)) { 147 qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start, 148 acb->end - acb->start); 149 acb->common.cb(acb->common.opaque, 0); 150 qemu_aio_release(acb); 151 s->acb[i] = NULL; 152 } 153 } 154 155 read_end: 156 return realsize; 157 } 158 159 static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len, 160 CURLAIOCB *acb) 161 { 162 int i; 163 size_t end = start + len; 164 165 for (i=0; i<CURL_NUM_STATES; i++) { 166 CURLState *state = &s->states[i]; 167 size_t buf_end = (state->buf_start + state->buf_off); 168 size_t buf_fend = (state->buf_start + state->buf_len); 169 170 if (!state->orig_buf) 171 continue; 172 if (!state->buf_off) 173 continue; 174 175 // Does the existing buffer cover our section? 176 if ((start >= state->buf_start) && 177 (start <= buf_end) && 178 (end >= state->buf_start) && 179 (end <= buf_end)) 180 { 181 char *buf = state->orig_buf + (start - state->buf_start); 182 183 qemu_iovec_from_buf(acb->qiov, 0, buf, len); 184 acb->common.cb(acb->common.opaque, 0); 185 186 return FIND_RET_OK; 187 } 188 189 // Wait for unfinished chunks 190 if ((start >= state->buf_start) && 191 (start <= buf_fend) && 192 (end >= state->buf_start) && 193 (end <= buf_fend)) 194 { 195 int j; 196 197 acb->start = start - state->buf_start; 198 acb->end = acb->start + len; 199 200 for (j=0; j<CURL_NUM_ACB; j++) { 201 if (!state->acb[j]) { 202 state->acb[j] = acb; 203 return FIND_RET_WAIT; 204 } 205 } 206 } 207 } 208 209 return FIND_RET_NONE; 210 } 211 212 static void curl_multi_do(void *arg) 213 { 214 BDRVCURLState *s = (BDRVCURLState *)arg; 215 int running; 216 int r; 217 int msgs_in_queue; 218 219 if (!s->multi) 220 return; 221 222 do { 223 r = curl_multi_socket_all(s->multi, &running); 224 } while(r == CURLM_CALL_MULTI_PERFORM); 225 226 /* Try to find done transfers, so we can free the easy 227 * handle again. */ 228 do { 229 CURLMsg *msg; 230 msg = curl_multi_info_read(s->multi, &msgs_in_queue); 231 232 if (!msg) 233 break; 234 if (msg->msg == CURLMSG_NONE) 235 break; 236 237 switch (msg->msg) { 238 case CURLMSG_DONE: 239 { 240 CURLState *state = NULL; 241 curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE, (char**)&state); 242 243 /* ACBs for successful messages get completed in curl_read_cb */ 244 if (msg->data.result != CURLE_OK) { 245 int i; 246 for (i = 0; i < CURL_NUM_ACB; i++) { 247 CURLAIOCB *acb = state->acb[i]; 248 249 if (acb == NULL) { 250 continue; 251 } 252 253 acb->common.cb(acb->common.opaque, -EIO); 254 qemu_aio_release(acb); 255 state->acb[i] = NULL; 256 } 257 } 258 259 curl_clean_state(state); 260 break; 261 } 262 default: 263 msgs_in_queue = 0; 264 break; 265 } 266 } while(msgs_in_queue); 267 } 268 269 static CURLState *curl_init_state(BDRVCURLState *s) 270 { 271 CURLState *state = NULL; 272 int i, j; 273 274 do { 275 for (i=0; i<CURL_NUM_STATES; i++) { 276 for (j=0; j<CURL_NUM_ACB; j++) 277 if (s->states[i].acb[j]) 278 continue; 279 if (s->states[i].in_use) 280 continue; 281 282 state = &s->states[i]; 283 state->in_use = 1; 284 break; 285 } 286 if (!state) { 287 g_usleep(100); 288 curl_multi_do(s); 289 } 290 } while(!state); 291 292 if (state->curl) 293 goto has_curl; 294 295 state->curl = curl_easy_init(); 296 if (!state->curl) 297 return NULL; 298 curl_easy_setopt(state->curl, CURLOPT_URL, s->url); 299 curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, 5); 300 curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, (void *)curl_read_cb); 301 curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state); 302 curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state); 303 curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1); 304 curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1); 305 curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1); 306 curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg); 307 curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1); 308 309 /* Restrict supported protocols to avoid security issues in the more 310 * obscure protocols. For example, do not allow POP3/SMTP/IMAP see 311 * CVE-2013-0249. 312 * 313 * Restricting protocols is only supported from 7.19.4 upwards. 314 */ 315 #if LIBCURL_VERSION_NUM >= 0x071304 316 curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS); 317 curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS); 318 #endif 319 320 #ifdef DEBUG_VERBOSE 321 curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1); 322 #endif 323 324 has_curl: 325 326 state->s = s; 327 328 return state; 329 } 330 331 static void curl_clean_state(CURLState *s) 332 { 333 if (s->s->multi) 334 curl_multi_remove_handle(s->s->multi, s->curl); 335 s->in_use = 0; 336 } 337 338 static int curl_open(BlockDriverState *bs, const char *filename, 339 QDict *options, int flags) 340 { 341 BDRVCURLState *s = bs->opaque; 342 CURLState *state = NULL; 343 double d; 344 345 #define RA_OPTSTR ":readahead=" 346 char *file; 347 char *ra; 348 const char *ra_val; 349 int parse_state = 0; 350 351 static int inited = 0; 352 353 file = g_strdup(filename); 354 s->readahead_size = READ_AHEAD_SIZE; 355 356 /* Parse a trailing ":readahead=#:" param, if present. */ 357 ra = file + strlen(file) - 1; 358 while (ra >= file) { 359 if (parse_state == 0) { 360 if (*ra == ':') 361 parse_state++; 362 else 363 break; 364 } else if (parse_state == 1) { 365 if (*ra > '9' || *ra < '0') { 366 char *opt_start = ra - strlen(RA_OPTSTR) + 1; 367 if (opt_start > file && 368 strncmp(opt_start, RA_OPTSTR, strlen(RA_OPTSTR)) == 0) { 369 ra_val = ra + 1; 370 ra -= strlen(RA_OPTSTR) - 1; 371 *ra = '\0'; 372 s->readahead_size = atoi(ra_val); 373 break; 374 } else { 375 break; 376 } 377 } 378 } 379 ra--; 380 } 381 382 if ((s->readahead_size & 0x1ff) != 0) { 383 fprintf(stderr, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512\n", 384 s->readahead_size); 385 goto out_noclean; 386 } 387 388 if (!inited) { 389 curl_global_init(CURL_GLOBAL_ALL); 390 inited = 1; 391 } 392 393 DPRINTF("CURL: Opening %s\n", file); 394 s->url = file; 395 state = curl_init_state(s); 396 if (!state) 397 goto out_noclean; 398 399 // Get file size 400 401 curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1); 402 curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, (void *)curl_size_cb); 403 if (curl_easy_perform(state->curl)) 404 goto out; 405 curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d); 406 curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, (void *)curl_read_cb); 407 curl_easy_setopt(state->curl, CURLOPT_NOBODY, 0); 408 if (d) 409 s->len = (size_t)d; 410 else if(!s->len) 411 goto out; 412 DPRINTF("CURL: Size = %zd\n", s->len); 413 414 curl_clean_state(state); 415 curl_easy_cleanup(state->curl); 416 state->curl = NULL; 417 418 // Now we know the file exists and its size, so let's 419 // initialize the multi interface! 420 421 s->multi = curl_multi_init(); 422 curl_multi_setopt( s->multi, CURLMOPT_SOCKETDATA, s); 423 curl_multi_setopt( s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb ); 424 curl_multi_do(s); 425 426 return 0; 427 428 out: 429 fprintf(stderr, "CURL: Error opening file: %s\n", state->errmsg); 430 curl_easy_cleanup(state->curl); 431 state->curl = NULL; 432 out_noclean: 433 g_free(file); 434 return -EINVAL; 435 } 436 437 static int curl_aio_flush(void *opaque) 438 { 439 BDRVCURLState *s = opaque; 440 int i, j; 441 442 for (i=0; i < CURL_NUM_STATES; i++) { 443 for(j=0; j < CURL_NUM_ACB; j++) { 444 if (s->states[i].acb[j]) { 445 return 1; 446 } 447 } 448 } 449 return 0; 450 } 451 452 static void curl_aio_cancel(BlockDriverAIOCB *blockacb) 453 { 454 // Do we have to implement canceling? Seems to work without... 455 } 456 457 static const AIOCBInfo curl_aiocb_info = { 458 .aiocb_size = sizeof(CURLAIOCB), 459 .cancel = curl_aio_cancel, 460 }; 461 462 463 static void curl_readv_bh_cb(void *p) 464 { 465 CURLState *state; 466 467 CURLAIOCB *acb = p; 468 BDRVCURLState *s = acb->common.bs->opaque; 469 470 qemu_bh_delete(acb->bh); 471 acb->bh = NULL; 472 473 size_t start = acb->sector_num * SECTOR_SIZE; 474 size_t end; 475 476 // In case we have the requested data already (e.g. read-ahead), 477 // we can just call the callback and be done. 478 switch (curl_find_buf(s, start, acb->nb_sectors * SECTOR_SIZE, acb)) { 479 case FIND_RET_OK: 480 qemu_aio_release(acb); 481 // fall through 482 case FIND_RET_WAIT: 483 return; 484 default: 485 break; 486 } 487 488 // No cache found, so let's start a new request 489 state = curl_init_state(s); 490 if (!state) { 491 acb->common.cb(acb->common.opaque, -EIO); 492 qemu_aio_release(acb); 493 return; 494 } 495 496 acb->start = 0; 497 acb->end = (acb->nb_sectors * SECTOR_SIZE); 498 499 state->buf_off = 0; 500 if (state->orig_buf) 501 g_free(state->orig_buf); 502 state->buf_start = start; 503 state->buf_len = acb->end + s->readahead_size; 504 end = MIN(start + state->buf_len, s->len) - 1; 505 state->orig_buf = g_malloc(state->buf_len); 506 state->acb[0] = acb; 507 508 snprintf(state->range, 127, "%zd-%zd", start, end); 509 DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n", 510 (acb->nb_sectors * SECTOR_SIZE), start, state->range); 511 curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range); 512 513 curl_multi_add_handle(s->multi, state->curl); 514 curl_multi_do(s); 515 516 } 517 518 static BlockDriverAIOCB *curl_aio_readv(BlockDriverState *bs, 519 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 520 BlockDriverCompletionFunc *cb, void *opaque) 521 { 522 CURLAIOCB *acb; 523 524 acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque); 525 526 acb->qiov = qiov; 527 acb->sector_num = sector_num; 528 acb->nb_sectors = nb_sectors; 529 530 acb->bh = qemu_bh_new(curl_readv_bh_cb, acb); 531 532 if (!acb->bh) { 533 DPRINTF("CURL: qemu_bh_new failed\n"); 534 return NULL; 535 } 536 537 qemu_bh_schedule(acb->bh); 538 return &acb->common; 539 } 540 541 static void curl_close(BlockDriverState *bs) 542 { 543 BDRVCURLState *s = bs->opaque; 544 int i; 545 546 DPRINTF("CURL: Close\n"); 547 for (i=0; i<CURL_NUM_STATES; i++) { 548 if (s->states[i].in_use) 549 curl_clean_state(&s->states[i]); 550 if (s->states[i].curl) { 551 curl_easy_cleanup(s->states[i].curl); 552 s->states[i].curl = NULL; 553 } 554 if (s->states[i].orig_buf) { 555 g_free(s->states[i].orig_buf); 556 s->states[i].orig_buf = NULL; 557 } 558 } 559 if (s->multi) 560 curl_multi_cleanup(s->multi); 561 g_free(s->url); 562 } 563 564 static int64_t curl_getlength(BlockDriverState *bs) 565 { 566 BDRVCURLState *s = bs->opaque; 567 return s->len; 568 } 569 570 static BlockDriver bdrv_http = { 571 .format_name = "http", 572 .protocol_name = "http", 573 574 .instance_size = sizeof(BDRVCURLState), 575 .bdrv_file_open = curl_open, 576 .bdrv_close = curl_close, 577 .bdrv_getlength = curl_getlength, 578 579 .bdrv_aio_readv = curl_aio_readv, 580 }; 581 582 static BlockDriver bdrv_https = { 583 .format_name = "https", 584 .protocol_name = "https", 585 586 .instance_size = sizeof(BDRVCURLState), 587 .bdrv_file_open = curl_open, 588 .bdrv_close = curl_close, 589 .bdrv_getlength = curl_getlength, 590 591 .bdrv_aio_readv = curl_aio_readv, 592 }; 593 594 static BlockDriver bdrv_ftp = { 595 .format_name = "ftp", 596 .protocol_name = "ftp", 597 598 .instance_size = sizeof(BDRVCURLState), 599 .bdrv_file_open = curl_open, 600 .bdrv_close = curl_close, 601 .bdrv_getlength = curl_getlength, 602 603 .bdrv_aio_readv = curl_aio_readv, 604 }; 605 606 static BlockDriver bdrv_ftps = { 607 .format_name = "ftps", 608 .protocol_name = "ftps", 609 610 .instance_size = sizeof(BDRVCURLState), 611 .bdrv_file_open = curl_open, 612 .bdrv_close = curl_close, 613 .bdrv_getlength = curl_getlength, 614 615 .bdrv_aio_readv = curl_aio_readv, 616 }; 617 618 static BlockDriver bdrv_tftp = { 619 .format_name = "tftp", 620 .protocol_name = "tftp", 621 622 .instance_size = sizeof(BDRVCURLState), 623 .bdrv_file_open = curl_open, 624 .bdrv_close = curl_close, 625 .bdrv_getlength = curl_getlength, 626 627 .bdrv_aio_readv = curl_aio_readv, 628 }; 629 630 static void curl_block_init(void) 631 { 632 bdrv_register(&bdrv_http); 633 bdrv_register(&bdrv_https); 634 bdrv_register(&bdrv_ftp); 635 bdrv_register(&bdrv_ftps); 636 bdrv_register(&bdrv_tftp); 637 } 638 639 block_init(curl_block_init); 640