Return to curl.c CVS log

Up to [Qemu by Fabrice Bellard] / qemu / block

Annotation of qemu/block/curl.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * QEMU Block driver for CURL images
        !             3:  *
        !             4:  * Copyright (c) 2009 Alexander Graf <[email protected]>
        !             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_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 CURL_NUM_STATES 8
        !            38: #define CURL_NUM_ACB    8
        !            39: #define SECTOR_SIZE     512
        !            40: #define READ_AHEAD_SIZE (256 * 1024)
        !            41: 
        !            42: #define FIND_RET_NONE   0
        !            43: #define FIND_RET_OK     1
        !            44: #define FIND_RET_WAIT   2
        !            45: 
        !            46: struct BDRVCURLState;
        !            47: 
        !            48: typedef struct CURLAIOCB {
        !            49:     BlockDriverAIOCB common;
        !            50:     QEMUIOVector *qiov;
        !            51:     size_t start;
        !            52:     size_t end;
        !            53: } CURLAIOCB;
        !            54: 
        !            55: typedef struct CURLState
        !            56: {
        !            57:     struct BDRVCURLState *s;
        !            58:     CURLAIOCB *acb[CURL_NUM_ACB];
        !            59:     CURL *curl;
        !            60:     char *orig_buf;
        !            61:     size_t buf_start;
        !            62:     size_t buf_off;
        !            63:     size_t buf_len;
        !            64:     char range[128];
        !            65:     char errmsg[CURL_ERROR_SIZE];
        !            66:     char in_use;
        !            67: } CURLState;
        !            68: 
        !            69: typedef struct BDRVCURLState {
        !            70:     CURLM *multi;
        !            71:     size_t len;
        !            72:     CURLState states[CURL_NUM_STATES];
        !            73:     char *url;
        !            74:     size_t readahead_size;
        !            75: } BDRVCURLState;
        !            76: 
        !            77: static void curl_clean_state(CURLState *s);
        !            78: static void curl_multi_do(void *arg);
        !            79: 
        !            80: static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
        !            81:                         void *s, void *sp)
        !            82: {
        !            83:     dprintf("CURL (AIO): Sock action %d on fd %d\n", action, fd);
        !            84:     switch (action) {
        !            85:         case CURL_POLL_IN:
        !            86:             qemu_aio_set_fd_handler(fd, curl_multi_do, NULL, NULL, s);
        !            87:             break;
        !            88:         case CURL_POLL_OUT:
        !            89:             qemu_aio_set_fd_handler(fd, NULL, curl_multi_do, NULL, s);
        !            90:             break;
        !            91:         case CURL_POLL_INOUT:
        !            92:             qemu_aio_set_fd_handler(fd, curl_multi_do,
        !            93:                                     curl_multi_do, NULL, s);
        !            94:             break;
        !            95:         case CURL_POLL_REMOVE:
        !            96:             qemu_aio_set_fd_handler(fd, NULL, NULL, NULL, NULL);
        !            97:             break;
        !            98:     }
        !            99: 
        !           100:     return 0;
        !           101: }
        !           102: 
        !           103: static size_t curl_size_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
        !           104: {
        !           105:     CURLState *s = ((CURLState*)opaque);
        !           106:     size_t realsize = size * nmemb;
        !           107:     long long fsize;
        !           108: 
        !           109:     if(sscanf(ptr, "Content-Length: %lld", &fsize) == 1)
        !           110:         s->s->len = fsize;
        !           111: 
        !           112:     return realsize;
        !           113: }
        !           114: 
        !           115: static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque)
        !           116: {
        !           117:     CURLState *s = ((CURLState*)opaque);
        !           118:     size_t realsize = size * nmemb;
        !           119:     int i;
        !           120: 
        !           121:     dprintf("CURL: Just reading %lld bytes\n", (unsigned long long)realsize);
        !           122: 
        !           123:     if (!s || !s->orig_buf)
        !           124:         goto read_end;
        !           125: 
        !           126:     memcpy(s->orig_buf + s->buf_off, ptr, realsize);
        !           127:     s->buf_off += realsize;
        !           128: 
        !           129:     for(i=0; i<CURL_NUM_ACB; i++) {
        !           130:         CURLAIOCB *acb = s->acb[i];
        !           131: 
        !           132:         if (!acb)
        !           133:             continue;
        !           134: 
        !           135:         if ((s->buf_off >= acb->end)) {
        !           136:             qemu_iovec_from_buffer(acb->qiov, s->orig_buf + acb->start,
        !           137:                                    acb->end - acb->start);
        !           138:             acb->common.cb(acb->common.opaque, 0);
        !           139:             qemu_aio_release(acb);
        !           140:             s->acb[i] = NULL;
        !           141:         }
        !           142:     }
        !           143: 
        !           144: read_end:
        !           145:     return realsize;
        !           146: }
        !           147: 
        !           148: static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len,
        !           149:                          CURLAIOCB *acb)
        !           150: {
        !           151:     int i;
        !           152:     size_t end = start + len;
        !           153: 
        !           154:     for (i=0; i<CURL_NUM_STATES; i++) {
        !           155:         CURLState *state = &s->states[i];
        !           156:         size_t buf_end = (state->buf_start + state->buf_off);
        !           157:         size_t buf_fend = (state->buf_start + state->buf_len);
        !           158: 
        !           159:         if (!state->orig_buf)
        !           160:             continue;
        !           161:         if (!state->buf_off)
        !           162:             continue;
        !           163: 
        !           164:         // Does the existing buffer cover our section?
        !           165:         if ((start >= state->buf_start) &&
        !           166:             (start <= buf_end) &&
        !           167:             (end >= state->buf_start) &&
        !           168:             (end <= buf_end))
        !           169:         {
        !           170:             char *buf = state->orig_buf + (start - state->buf_start);
        !           171: 
        !           172:             qemu_iovec_from_buffer(acb->qiov, buf, len);
        !           173:             acb->common.cb(acb->common.opaque, 0);
        !           174: 
        !           175:             return FIND_RET_OK;
        !           176:         }
        !           177: 
        !           178:         // Wait for unfinished chunks
        !           179:         if ((start >= state->buf_start) &&
        !           180:             (start <= buf_fend) &&
        !           181:             (end >= state->buf_start) &&
        !           182:             (end <= buf_fend))
        !           183:         {
        !           184:             int j;
        !           185: 
        !           186:             acb->start = start - state->buf_start;
        !           187:             acb->end = acb->start + len;
        !           188: 
        !           189:             for (j=0; j<CURL_NUM_ACB; j++) {
        !           190:                 if (!state->acb[j]) {
        !           191:                     state->acb[j] = acb;
        !           192:                     return FIND_RET_WAIT;
        !           193:                 }
        !           194:             }
        !           195:         }
        !           196:     }
        !           197: 
        !           198:     return FIND_RET_NONE;
        !           199: }
        !           200: 
        !           201: static void curl_multi_do(void *arg)
        !           202: {
        !           203:     BDRVCURLState *s = (BDRVCURLState *)arg;
        !           204:     int running;
        !           205:     int r;
        !           206:     int msgs_in_queue;
        !           207: 
        !           208:     if (!s->multi)
        !           209:         return;
        !           210: 
        !           211:     do {
        !           212:         r = curl_multi_socket_all(s->multi, &running);
        !           213:     } while(r == CURLM_CALL_MULTI_PERFORM);
        !           214: 
        !           215:     /* Try to find done transfers, so we can free the easy
        !           216:      * handle again. */
        !           217:     do {
        !           218:         CURLMsg *msg;
        !           219:         msg = curl_multi_info_read(s->multi, &msgs_in_queue);
        !           220: 
        !           221:         if (!msg)
        !           222:             break;
        !           223:         if (msg->msg == CURLMSG_NONE)
        !           224:             break;
        !           225: 
        !           226:         switch (msg->msg) {
        !           227:             case CURLMSG_DONE:
        !           228:             {
        !           229:                 CURLState *state = NULL;
        !           230:                 curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE, (char**)&state);
        !           231:                 curl_clean_state(state);
        !           232:                 break;
        !           233:             }
        !           234:             default:
        !           235:                 msgs_in_queue = 0;
        !           236:                 break;
        !           237:         }
        !           238:     } while(msgs_in_queue);
        !           239: }
        !           240: 
        !           241: static CURLState *curl_init_state(BDRVCURLState *s)
        !           242: {
        !           243:     CURLState *state = NULL;
        !           244:     int i, j;
        !           245: 
        !           246:     do {
        !           247:         for (i=0; i<CURL_NUM_STATES; i++) {
        !           248:             for (j=0; j<CURL_NUM_ACB; j++)
        !           249:                 if (s->states[i].acb[j])
        !           250:                     continue;
        !           251:             if (s->states[i].in_use)
        !           252:                 continue;
        !           253: 
        !           254:             state = &s->states[i];
        !           255:             state->in_use = 1;
        !           256:             break;
        !           257:         }
        !           258:         if (!state) {
        !           259:             usleep(100);
        !           260:             curl_multi_do(s);
        !           261:         }
        !           262:     } while(!state);
        !           263: 
        !           264:     if (state->curl)
        !           265:         goto has_curl;
        !           266: 
        !           267:     state->curl = curl_easy_init();
        !           268:     if (!state->curl)
        !           269:         return NULL;
        !           270:     curl_easy_setopt(state->curl, CURLOPT_URL, s->url);
        !           271:     curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, 5);
        !           272:     curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, (void *)curl_read_cb);
        !           273:     curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state);
        !           274:     curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state);
        !           275:     curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1);
        !           276:     curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1);
        !           277:     curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1);
        !           278:     curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg);
        !           279:     
        !           280: #ifdef DEBUG_VERBOSE
        !           281:     curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1);
        !           282: #endif
        !           283: 
        !           284: has_curl:
        !           285: 
        !           286:     state->s = s;
        !           287: 
        !           288:     return state;
        !           289: }
        !           290: 
        !           291: static void curl_clean_state(CURLState *s)
        !           292: {
        !           293:     if (s->s->multi)
        !           294:         curl_multi_remove_handle(s->s->multi, s->curl);
        !           295:     s->in_use = 0;
        !           296: }
        !           297: 
        !           298: static int curl_open(BlockDriverState *bs, const char *filename, int flags)
        !           299: {
        !           300:     BDRVCURLState *s = bs->opaque;
        !           301:     CURLState *state = NULL;
        !           302:     double d;
        !           303: 
        !           304:     #define RA_OPTSTR ":readahead="
        !           305:     char *file;
        !           306:     char *ra;
        !           307:     const char *ra_val;
        !           308:     int parse_state = 0;
        !           309: 
        !           310:     static int inited = 0;
        !           311: 
        !           312:     file = strdup(filename);
        !           313:     s->readahead_size = READ_AHEAD_SIZE;
        !           314: 
        !           315:     /* Parse a trailing ":readahead=#:" param, if present. */
        !           316:     ra = file + strlen(file) - 1;
        !           317:     while (ra >= file) {
        !           318:         if (parse_state == 0) {
        !           319:             if (*ra == ':')
        !           320:                 parse_state++;
        !           321:             else
        !           322:                 break;
        !           323:         } else if (parse_state == 1) {
        !           324:             if (*ra > '9' || *ra < '0') {
        !           325:                 char *opt_start = ra - strlen(RA_OPTSTR) + 1;
        !           326:                 if (opt_start > file &&
        !           327:                     strncmp(opt_start, RA_OPTSTR, strlen(RA_OPTSTR)) == 0) {
        !           328:                     ra_val = ra + 1;
        !           329:                     ra -= strlen(RA_OPTSTR) - 1;
        !           330:                     *ra = '\0';
        !           331:                     s->readahead_size = atoi(ra_val);
        !           332:                     break;
        !           333:                 } else {
        !           334:                     break;
        !           335:                 }
        !           336:             }
        !           337:         }
        !           338:         ra--;
        !           339:     }
        !           340: 
        !           341:     if ((s->readahead_size & 0x1ff) != 0) {
        !           342:         fprintf(stderr, "HTTP_READAHEAD_SIZE %Zd is not a multiple of 512\n",
        !           343:                 s->readahead_size);
        !           344:         goto out_noclean;
        !           345:     }
        !           346: 
        !           347:     if (!inited) {
        !           348:         curl_global_init(CURL_GLOBAL_ALL);
        !           349:         inited = 1;
        !           350:     }
        !           351: 
        !           352:     dprintf("CURL: Opening %s\n", file);
        !           353:     s->url = file;
        !           354:     state = curl_init_state(s);
        !           355:     if (!state)
        !           356:         goto out_noclean;
        !           357: 
        !           358:     // Get file size
        !           359: 
        !           360:     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1);
        !           361:     curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, (void *)curl_size_cb);
        !           362:     if (curl_easy_perform(state->curl))
        !           363:         goto out;
        !           364:     curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d);
        !           365:     curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, (void *)curl_read_cb);
        !           366:     curl_easy_setopt(state->curl, CURLOPT_NOBODY, 0);
        !           367:     if (d)
        !           368:         s->len = (size_t)d;
        !           369:     else if(!s->len)
        !           370:         goto out;
        !           371:     dprintf("CURL: Size = %lld\n", (long long)s->len);
        !           372: 
        !           373:     curl_clean_state(state);
        !           374:     curl_easy_cleanup(state->curl);
        !           375:     state->curl = NULL;
        !           376: 
        !           377:     // Now we know the file exists and its size, so let's
        !           378:     // initialize the multi interface!
        !           379: 
        !           380:     s->multi = curl_multi_init();
        !           381:     curl_multi_setopt( s->multi, CURLMOPT_SOCKETDATA, s); 
        !           382:     curl_multi_setopt( s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb ); 
        !           383:     curl_multi_do(s);
        !           384: 
        !           385:     return 0;
        !           386: 
        !           387: out:
        !           388:     fprintf(stderr, "CURL: Error opening file: %s\n", state->errmsg);
        !           389:     curl_easy_cleanup(state->curl);
        !           390:     state->curl = NULL;
        !           391: out_noclean:
        !           392:     qemu_free(file);
        !           393:     return -EINVAL;
        !           394: }
        !           395: 
        !           396: static void curl_aio_cancel(BlockDriverAIOCB *blockacb)
        !           397: {
        !           398:     // Do we have to implement canceling? Seems to work without...
        !           399: }
        !           400: 
        !           401: static AIOPool curl_aio_pool = {
        !           402:     .aiocb_size         = sizeof(CURLAIOCB),
        !           403:     .cancel             = curl_aio_cancel,
        !           404: };
        !           405: 
        !           406: static BlockDriverAIOCB *curl_aio_readv(BlockDriverState *bs,
        !           407:         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
        !           408:         BlockDriverCompletionFunc *cb, void *opaque)
        !           409: {
        !           410:     BDRVCURLState *s = bs->opaque;
        !           411:     CURLAIOCB *acb;
        !           412:     size_t start = sector_num * SECTOR_SIZE;
        !           413:     size_t end;
        !           414:     CURLState *state;
        !           415: 
        !           416:     acb = qemu_aio_get(&curl_aio_pool, bs, cb, opaque);
        !           417:     if (!acb)
        !           418:         return NULL;
        !           419: 
        !           420:     acb->qiov = qiov;
        !           421: 
        !           422:     // In case we have the requested data already (e.g. read-ahead),
        !           423:     // we can just call the callback and be done.
        !           424: 
        !           425:     switch (curl_find_buf(s, start, nb_sectors * SECTOR_SIZE, acb)) {
        !           426:         case FIND_RET_OK:
        !           427:             qemu_aio_release(acb);
        !           428:             // fall through
        !           429:         case FIND_RET_WAIT:
        !           430:             return &acb->common;
        !           431:         default:
        !           432:             break;
        !           433:     }
        !           434: 
        !           435:     // No cache found, so let's start a new request
        !           436: 
        !           437:     state = curl_init_state(s);
        !           438:     if (!state)
        !           439:         return NULL;
        !           440: 
        !           441:     acb->start = 0;
        !           442:     acb->end = (nb_sectors * SECTOR_SIZE);
        !           443: 
        !           444:     state->buf_off = 0;
        !           445:     if (state->orig_buf)
        !           446:         qemu_free(state->orig_buf);
        !           447:     state->buf_start = start;
        !           448:     state->buf_len = acb->end + s->readahead_size;
        !           449:     end = MIN(start + state->buf_len, s->len) - 1;
        !           450:     state->orig_buf = qemu_malloc(state->buf_len);
        !           451:     state->acb[0] = acb;
        !           452: 
        !           453:     snprintf(state->range, 127, "%lld-%lld", (long long)start, (long long)end);
        !           454:     dprintf("CURL (AIO): Reading %d at %lld (%s)\n", (nb_sectors * SECTOR_SIZE), start, state->range);
        !           455:     curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
        !           456: 
        !           457:     curl_multi_add_handle(s->multi, state->curl);
        !           458:     curl_multi_do(s);
        !           459: 
        !           460:     return &acb->common;
        !           461: }
        !           462: 
        !           463: static void curl_close(BlockDriverState *bs)
        !           464: {
        !           465:     BDRVCURLState *s = bs->opaque;
        !           466:     int i;
        !           467: 
        !           468:     dprintf("CURL: Close\n");
        !           469:     for (i=0; i<CURL_NUM_STATES; i++) {
        !           470:         if (s->states[i].in_use)
        !           471:             curl_clean_state(&s->states[i]);
        !           472:         if (s->states[i].curl) {
        !           473:             curl_easy_cleanup(s->states[i].curl);
        !           474:             s->states[i].curl = NULL;
        !           475:         }
        !           476:         if (s->states[i].orig_buf) {
        !           477:             qemu_free(s->states[i].orig_buf);
        !           478:             s->states[i].orig_buf = NULL;
        !           479:         }
        !           480:     }
        !           481:     if (s->multi)
        !           482:         curl_multi_cleanup(s->multi);
        !           483:     if (s->url)
        !           484:         free(s->url);
        !           485: }
        !           486: 
        !           487: static int64_t curl_getlength(BlockDriverState *bs)
        !           488: {
        !           489:     BDRVCURLState *s = bs->opaque;
        !           490:     return s->len;
        !           491: }
        !           492: 
        !           493: static BlockDriver bdrv_http = {
        !           494:     .format_name     = "http",
        !           495:     .protocol_name   = "http",
        !           496: 
        !           497:     .instance_size   = sizeof(BDRVCURLState),
        !           498:     .bdrv_open       = curl_open,
        !           499:     .bdrv_close      = curl_close,
        !           500:     .bdrv_getlength  = curl_getlength,
        !           501: 
        !           502:     .bdrv_aio_readv  = curl_aio_readv,
        !           503: };
        !           504: 
        !           505: static BlockDriver bdrv_https = {
        !           506:     .format_name     = "https",
        !           507:     .protocol_name   = "https",
        !           508: 
        !           509:     .instance_size   = sizeof(BDRVCURLState),
        !           510:     .bdrv_open       = curl_open,
        !           511:     .bdrv_close      = curl_close,
        !           512:     .bdrv_getlength  = curl_getlength,
        !           513: 
        !           514:     .bdrv_aio_readv  = curl_aio_readv,
        !           515: };
        !           516: 
        !           517: static BlockDriver bdrv_ftp = {
        !           518:     .format_name     = "ftp",
        !           519:     .protocol_name   = "ftp",
        !           520: 
        !           521:     .instance_size   = sizeof(BDRVCURLState),
        !           522:     .bdrv_open       = curl_open,
        !           523:     .bdrv_close      = curl_close,
        !           524:     .bdrv_getlength  = curl_getlength,
        !           525: 
        !           526:     .bdrv_aio_readv  = curl_aio_readv,
        !           527: };
        !           528: 
        !           529: static BlockDriver bdrv_ftps = {
        !           530:     .format_name     = "ftps",
        !           531:     .protocol_name   = "ftps",
        !           532: 
        !           533:     .instance_size   = sizeof(BDRVCURLState),
        !           534:     .bdrv_open       = curl_open,
        !           535:     .bdrv_close      = curl_close,
        !           536:     .bdrv_getlength  = curl_getlength,
        !           537: 
        !           538:     .bdrv_aio_readv  = curl_aio_readv,
        !           539: };
        !           540: 
        !           541: static BlockDriver bdrv_tftp = {
        !           542:     .format_name     = "tftp",
        !           543:     .protocol_name   = "tftp",
        !           544: 
        !           545:     .instance_size   = sizeof(BDRVCURLState),
        !           546:     .bdrv_open       = curl_open,
        !           547:     .bdrv_close      = curl_close,
        !           548:     .bdrv_getlength  = curl_getlength,
        !           549: 
        !           550:     .bdrv_aio_readv  = curl_aio_readv,
        !           551: };
        !           552: 
        !           553: static void curl_block_init(void)
        !           554: {
        !           555:     bdrv_register(&bdrv_http);
        !           556:     bdrv_register(&bdrv_https);
        !           557:     bdrv_register(&bdrv_ftp);
        !           558:     bdrv_register(&bdrv_ftps);
        !           559:     bdrv_register(&bdrv_tftp);
        !           560: }
        !           561: 
        !           562: block_init(curl_block_init);

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.