diff options
Diffstat (limited to 'block/curl.c')
-rw-r--r-- | block/curl.c | 523 |
1 files changed, 523 insertions, 0 deletions
diff --git a/block/curl.c b/block/curl.c new file mode 100644 index 0000000000..5d1487dea1 --- /dev/null +++ b/block/curl.c @@ -0,0 +1,523 @@ +/* + * QEMU Block driver for CURL images + * + * Copyright (c) 2009 Alexander Graf <agraf@suse.de> + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +#include "qemu-common.h" +#include "block_int.h" +#include <curl/curl.h> + +// #define DEBUG +// #define DEBUG_VERBOSE + +#ifdef DEBUG_CURL +#define dprintf(fmt, ...) do { printf(fmt, ## __VA_ARGS__); } while (0) +#else +#define dprintf(fmt, ...) do { } while (0) +#endif + +#define CURL_NUM_STATES 8 +#define CURL_NUM_ACB 8 +#define SECTOR_SIZE 512 +#define READ_AHEAD_SIZE (256 * 1024) + +#define FIND_RET_NONE 0 +#define FIND_RET_OK 1 +#define FIND_RET_WAIT 2 + +struct BDRVCURLState; + +typedef struct CURLAIOCB { + BlockDriverAIOCB common; + QEMUIOVector *qiov; + size_t start; + size_t end; +} CURLAIOCB; + +typedef struct CURLState +{ + struct BDRVCURLState *s; + CURLAIOCB *acb[CURL_NUM_ACB]; + CURL *curl; + char *orig_buf; + size_t buf_start; + size_t buf_off; + size_t buf_len; + char range[128]; + char errmsg[CURL_ERROR_SIZE]; + char in_use; +} CURLState; + +typedef struct BDRVCURLState { + CURLM *multi; + size_t len; + CURLState states[CURL_NUM_STATES]; + char *url; +} BDRVCURLState; + +static void curl_clean_state(CURLState *s); +static void curl_multi_do(void *arg); + +static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action, + void *s, void *sp) +{ + dprintf("CURL (AIO): Sock action %d on fd %d\n", action, fd); + switch (action) { + case CURL_POLL_IN: + qemu_aio_set_fd_handler(fd, curl_multi_do, NULL, NULL, s); + break; + case CURL_POLL_OUT: + qemu_aio_set_fd_handler(fd, NULL, curl_multi_do, NULL, s); + break; + case CURL_POLL_INOUT: + qemu_aio_set_fd_handler(fd, curl_multi_do, + curl_multi_do, NULL, s); + break; + case CURL_POLL_REMOVE: + qemu_aio_set_fd_handler(fd, NULL, NULL, NULL, NULL); + break; + } + + return 0; +} + +static size_t curl_size_cb(void *ptr, size_t size, size_t nmemb, void *opaque) +{ + CURLState *s = ((CURLState*)opaque); + size_t realsize = size * nmemb; + long long fsize; + + if(sscanf(ptr, "Content-Length: %lld", &fsize) == 1) + s->s->len = fsize; + + return realsize; +} + +static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void *opaque) +{ + CURLState *s = ((CURLState*)opaque); + size_t realsize = size * nmemb; + int i; + + dprintf("CURL: Just reading %lld bytes\n", (unsigned long long)realsize); + + if (!s || !s->orig_buf) + goto read_end; + + memcpy(s->orig_buf + s->buf_off, ptr, realsize); + s->buf_off += realsize; + + for(i=0; i<CURL_NUM_ACB; i++) { + CURLAIOCB *acb = s->acb[i]; + + if (!acb) + continue; + + if ((s->buf_off >= acb->end)) { + qemu_iovec_from_buffer(acb->qiov, s->orig_buf + acb->start, + acb->end - acb->start); + acb->common.cb(acb->common.opaque, 0); + qemu_aio_release(acb); + s->acb[i] = NULL; + } + } + +read_end: + return realsize; +} + +static int curl_find_buf(BDRVCURLState *s, size_t start, size_t len, + CURLAIOCB *acb) +{ + int i; + size_t end = start + len; + + for (i=0; i<CURL_NUM_STATES; i++) { + CURLState *state = &s->states[i]; + size_t buf_end = (state->buf_start + state->buf_off); + size_t buf_fend = (state->buf_start + state->buf_len); + + if (!state->orig_buf) + continue; + if (!state->buf_off) + continue; + + // Does the existing buffer cover our section? + if ((start >= state->buf_start) && + (start <= buf_end) && + (end >= state->buf_start) && + (end <= buf_end)) + { + char *buf = state->orig_buf + (start - state->buf_start); + + qemu_iovec_from_buffer(acb->qiov, buf, len); + acb->common.cb(acb->common.opaque, 0); + + return FIND_RET_OK; + } + + // Wait for unfinished chunks + if ((start >= state->buf_start) && + (start <= buf_fend) && + (end >= state->buf_start) && + (end <= buf_fend)) + { + int j; + + acb->start = start - state->buf_start; + acb->end = acb->start + len; + + for (j=0; j<CURL_NUM_ACB; j++) { + if (!state->acb[j]) { + state->acb[j] = acb; + return FIND_RET_WAIT; + } + } + } + } + + return FIND_RET_NONE; +} + +static void curl_multi_do(void *arg) +{ + BDRVCURLState *s = (BDRVCURLState *)arg; + int running; + int r; + int msgs_in_queue; + + if (!s->multi) + return; + + do { + r = curl_multi_socket_all(s->multi, &running); + } while(r == CURLM_CALL_MULTI_PERFORM); + + /* Try to find done transfers, so we can free the easy + * handle again. */ + do { + CURLMsg *msg; + msg = curl_multi_info_read(s->multi, &msgs_in_queue); + + if (!msg) + break; + if (msg->msg == CURLMSG_NONE) + break; + + switch (msg->msg) { + case CURLMSG_DONE: + { + CURLState *state = NULL; + curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE, (char**)&state); + curl_clean_state(state); + break; + } + default: + msgs_in_queue = 0; + break; + } + } while(msgs_in_queue); +} + +static CURLState *curl_init_state(BDRVCURLState *s) +{ + CURLState *state = NULL; + int i, j; + + do { + for (i=0; i<CURL_NUM_STATES; i++) { + for (j=0; j<CURL_NUM_ACB; j++) + if (s->states[i].acb[j]) + continue; + if (s->states[i].in_use) + continue; + + state = &s->states[i]; + state->in_use = 1; + break; + } + if (!state) { + usleep(100); + curl_multi_do(s); + } + } while(!state); + + if (state->curl) + goto has_curl; + + state->curl = curl_easy_init(); + if (!state->curl) + return NULL; + curl_easy_setopt(state->curl, CURLOPT_URL, s->url); + curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, 5); + curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, curl_read_cb); + curl_easy_setopt(state->curl, CURLOPT_WRITEDATA, (void *)state); + curl_easy_setopt(state->curl, CURLOPT_PRIVATE, (void *)state); + curl_easy_setopt(state->curl, CURLOPT_AUTOREFERER, 1); + curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1); + curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1); + curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg); + +#ifdef DEBUG_VERBOSE + curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1); +#endif + +has_curl: + + state->s = s; + + return state; +} + +static void curl_clean_state(CURLState *s) +{ + if (s->s->multi) + curl_multi_remove_handle(s->s->multi, s->curl); + s->in_use = 0; +} + +static int curl_open(BlockDriverState *bs, const char *filename, int flags) +{ + BDRVCURLState *s = bs->opaque; + CURLState *state = NULL; + double d; + static int inited = 0; + + if (!inited) { + curl_global_init(CURL_GLOBAL_ALL); + inited = 1; + } + + dprintf("CURL: Opening %s\n", filename); + s->url = strdup(filename); + state = curl_init_state(s); + if (!state) + goto out_noclean; + + // Get file size + + curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1); + curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, curl_size_cb); + if (curl_easy_perform(state->curl)) + goto out; + curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d); + curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, curl_read_cb); + curl_easy_setopt(state->curl, CURLOPT_NOBODY, 0); + if (d) + s->len = (size_t)d; + else if(!s->len) + goto out; + dprintf("CURL: Size = %lld\n", (long long)s->len); + + curl_clean_state(state); + curl_easy_cleanup(state->curl); + state->curl = NULL; + + // Now we know the file exists and its size, so let's + // initialize the multi interface! + + s->multi = curl_multi_init(); + curl_multi_setopt( s->multi, CURLMOPT_SOCKETDATA, s); + curl_multi_setopt( s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb ); + curl_multi_do(s); + + return 0; + +out: + fprintf(stderr, "CURL: Error opening file: %s\n", state->errmsg); + curl_easy_cleanup(state->curl); + state->curl = NULL; +out_noclean: + return -EINVAL; +} + +static BlockDriverAIOCB *curl_aio_readv(BlockDriverState *bs, + int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, + BlockDriverCompletionFunc *cb, void *opaque) +{ + BDRVCURLState *s = bs->opaque; + CURLAIOCB *acb; + size_t start = sector_num * SECTOR_SIZE; + size_t end; + CURLState *state; + + acb = qemu_aio_get(bs, cb, opaque); + if (!acb) + return NULL; + + acb->qiov = qiov; + + // In case we have the requested data already (e.g. read-ahead), + // we can just call the callback and be done. + + switch (curl_find_buf(s, start, nb_sectors * SECTOR_SIZE, acb)) { + case FIND_RET_OK: + qemu_aio_release(acb); + // fall through + case FIND_RET_WAIT: + return &acb->common; + default: + break; + } + + // No cache found, so let's start a new request + + state = curl_init_state(s); + if (!state) + return NULL; + + acb->start = 0; + acb->end = (nb_sectors * SECTOR_SIZE); + + state->buf_off = 0; + if (state->orig_buf) + qemu_free(state->orig_buf); + state->buf_start = start; + state->buf_len = acb->end + READ_AHEAD_SIZE; + end = MIN(start + state->buf_len, s->len) - 1; + state->orig_buf = qemu_malloc(state->buf_len); + state->acb[0] = acb; + + snprintf(state->range, 127, "%lld-%lld", (long long)start, (long long)end); + dprintf("CURL (AIO): Reading %d at %lld (%s)\n", (nb_sectors * SECTOR_SIZE), start, state->range); + curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range); + + curl_multi_add_handle(s->multi, state->curl); + curl_multi_do(s); + + return &acb->common; +} + +static void curl_aio_cancel(BlockDriverAIOCB *blockacb) +{ + // Do we have to implement canceling? Seems to work without... +} + +static void curl_close(BlockDriverState *bs) +{ + BDRVCURLState *s = bs->opaque; + int i; + + dprintf("CURL: Close\n"); + for (i=0; i<CURL_NUM_STATES; i++) { + if (s->states[i].in_use) + curl_clean_state(&s->states[i]); + if (s->states[i].curl) { + curl_easy_cleanup(s->states[i].curl); + s->states[i].curl = NULL; + } + if (s->states[i].orig_buf) { + qemu_free(s->states[i].orig_buf); + s->states[i].orig_buf = NULL; + } + } + if (s->multi) + curl_multi_cleanup(s->multi); + if (s->url) + free(s->url); +} + +static int64_t curl_getlength(BlockDriverState *bs) +{ + BDRVCURLState *s = bs->opaque; + return s->len; +} + +static BlockDriver bdrv_http = { + .format_name = "http", + .protocol_name = "http", + + .instance_size = sizeof(BDRVCURLState), + .bdrv_open = curl_open, + .bdrv_close = curl_close, + .bdrv_getlength = curl_getlength, + + .aiocb_size = sizeof(CURLAIOCB), + .bdrv_aio_readv = curl_aio_readv, + .bdrv_aio_cancel = curl_aio_cancel, +}; + +static BlockDriver bdrv_https = { + .format_name = "https", + .protocol_name = "https", + + .instance_size = sizeof(BDRVCURLState), + .bdrv_open = curl_open, + .bdrv_close = curl_close, + .bdrv_getlength = curl_getlength, + + .aiocb_size = sizeof(CURLAIOCB), + .bdrv_aio_readv = curl_aio_readv, + .bdrv_aio_cancel = curl_aio_cancel, +}; + +static BlockDriver bdrv_ftp = { + .format_name = "ftp", + .protocol_name = "ftp", + + .instance_size = sizeof(BDRVCURLState), + .bdrv_open = curl_open, + .bdrv_close = curl_close, + .bdrv_getlength = curl_getlength, + + .aiocb_size = sizeof(CURLAIOCB), + .bdrv_aio_readv = curl_aio_readv, + .bdrv_aio_cancel = curl_aio_cancel, +}; + +static BlockDriver bdrv_ftps = { + .format_name = "ftps", + .protocol_name = "ftps", + + .instance_size = sizeof(BDRVCURLState), + .bdrv_open = curl_open, + .bdrv_close = curl_close, + .bdrv_getlength = curl_getlength, + + .aiocb_size = sizeof(CURLAIOCB), + .bdrv_aio_readv = curl_aio_readv, + .bdrv_aio_cancel = curl_aio_cancel, +}; + +static BlockDriver bdrv_tftp = { + .format_name = "tftp", + .protocol_name = "tftp", + + .instance_size = sizeof(BDRVCURLState), + .bdrv_open = curl_open, + .bdrv_close = curl_close, + .bdrv_getlength = curl_getlength, + + .aiocb_size = sizeof(CURLAIOCB), + .bdrv_aio_readv = curl_aio_readv, + .bdrv_aio_cancel = curl_aio_cancel, +}; + +static void curl_block_init(void) +{ + bdrv_register(&bdrv_http); + bdrv_register(&bdrv_https); + bdrv_register(&bdrv_ftp); + bdrv_register(&bdrv_ftps); + bdrv_register(&bdrv_tftp); +} + +block_init(curl_block_init); |