/* * 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/block_int.h" #include "qapi/qmp/qbool.h" #include <curl/curl.h> // #define DEBUG_CURL // #define DEBUG_VERBOSE #ifdef DEBUG_CURL #define DPRINTF(fmt, ...) do { printf(fmt, ## __VA_ARGS__); } while (0) #else #define DPRINTF(fmt, ...) do { } while (0) #endif #if LIBCURL_VERSION_NUM >= 0x071000 /* The multi interface timer callback was introduced in 7.16.0 */ #define NEED_CURL_TIMER_CALLBACK #define HAVE_SOCKET_ACTION #endif #ifndef HAVE_SOCKET_ACTION /* If curl_multi_socket_action isn't available, define it statically here in * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is * less efficient but still safe. */ static CURLMcode __curl_multi_socket_action(CURLM *multi_handle, curl_socket_t sockfd, int ev_bitmask, int *running_handles) { return curl_multi_socket(multi_handle, sockfd, running_handles); } #define curl_multi_socket_action __curl_multi_socket_action #endif #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \ CURLPROTO_FTP | CURLPROTO_FTPS | \ CURLPROTO_TFTP) #define CURL_NUM_STATES 8 #define CURL_NUM_ACB 8 #define SECTOR_SIZE 512 #define READ_AHEAD_DEFAULT (256 * 1024) #define CURL_TIMEOUT_DEFAULT 5 #define FIND_RET_NONE 0 #define FIND_RET_OK 1 #define FIND_RET_WAIT 2 #define CURL_BLOCK_OPT_URL "url" #define CURL_BLOCK_OPT_READAHEAD "readahead" #define CURL_BLOCK_OPT_SSLVERIFY "sslverify" #define CURL_BLOCK_OPT_TIMEOUT "timeout" #define CURL_BLOCK_OPT_COOKIE "cookie" struct BDRVCURLState; typedef struct CURLAIOCB { BlockAIOCB common; QEMUBH *bh; QEMUIOVector *qiov; int64_t sector_num; int nb_sectors; size_t start; size_t end; } CURLAIOCB; typedef struct CURLState { struct BDRVCURLState *s; CURLAIOCB *acb[CURL_NUM_ACB]; CURL *curl; curl_socket_t sock_fd; 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; QEMUTimer timer; size_t len; CURLState states[CURL_NUM_STATES]; char *url; size_t readahead_size; bool sslverify; int timeout; char *cookie; bool accept_range; AioContext *aio_context; } BDRVCURLState; static void curl_clean_state(CURLState *s); static void curl_multi_do(void *arg); static void curl_multi_read(void *arg); #ifdef NEED_CURL_TIMER_CALLBACK static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque) { BDRVCURLState *s = opaque; DPRINTF("CURL: timer callback timeout_ms %ld\n", timeout_ms); if (timeout_ms == -1) { timer_del(&s->timer); } else { int64_t timeout_ns = (int64_t)timeout_ms * 1000 * 1000; timer_mod(&s->timer, qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ns); } return 0; } #endif static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action, void *userp, void *sp) { BDRVCURLState *s; CURLState *state = NULL; curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state); state->sock_fd = fd; s = state->s; DPRINTF("CURL (AIO): Sock action %d on fd %d\n", action, fd); switch (action) { case CURL_POLL_IN: aio_set_fd_handler(s->aio_context, fd, curl_multi_read, NULL, state); break; case CURL_POLL_OUT: aio_set_fd_handler(s->aio_context, fd, NULL, curl_multi_do, state); break; case CURL_POLL_INOUT: aio_set_fd_handler(s->aio_context, fd, curl_multi_read, curl_multi_do, state); break; case CURL_POLL_REMOVE: aio_set_fd_handler(s->aio_context, fd, NULL, NULL, NULL); break; } return 0; } static size_t curl_header_cb(void *ptr, size_t size, size_t nmemb, void *opaque) { BDRVCURLState *s = opaque; size_t realsize = size * nmemb; const char *accept_line = "Accept-Ranges: bytes"; if (realsize >= strlen(accept_line) && strncmp((char *)ptr, accept_line, strlen(accept_line)) == 0) { s->accept_range = true; } 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 %zd bytes\n", realsize); if (!s || !s->orig_buf) return 0; if (s->buf_off >= s->buf_len) { /* buffer full, read nothing */ return 0; } realsize = MIN(realsize, s->buf_len - s->buf_off); 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_buf(acb->qiov, 0, s->orig_buf + acb->start, acb->end - acb->start); acb->common.cb(acb->common.opaque, 0); qemu_aio_unref(acb); s->acb[i] = NULL; } } 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_buf(acb->qiov, 0, buf, len); acb->common.cb(acb->common.opaque, 0); return FIND_RET_OK; } // Wait for unfinished chunks if (state->in_use && (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_check_completion(BDRVCURLState *s) { int msgs_in_queue; /* Try to find done transfers, so we can free the easy * handle again. */ for (;;) { CURLMsg *msg; msg = curl_multi_info_read(s->multi, &msgs_in_queue); /* Quit when there are no more completions */ if (!msg) break; if (msg->msg == CURLMSG_DONE) { CURLState *state = NULL; curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE, (char **)&state); /* ACBs for successful messages get completed in curl_read_cb */ if (msg->data.result != CURLE_OK) { int i; for (i = 0; i < CURL_NUM_ACB; i++) { CURLAIOCB *acb = state->acb[i]; if (acb == NULL) { continue; } acb->common.cb(acb->common.opaque, -EIO); qemu_aio_unref(acb); state->acb[i] = NULL; } } curl_clean_state(state); break; } } } static void curl_multi_do(void *arg) { CURLState *s = (CURLState *)arg; int running; int r; if (!s->s->multi) { return; } do { r = curl_multi_socket_action(s->s->multi, s->sock_fd, 0, &running); } while(r == CURLM_CALL_MULTI_PERFORM); } static void curl_multi_read(void *arg) { CURLState *s = (CURLState *)arg; curl_multi_do(arg); curl_multi_check_completion(s->s); } static void curl_multi_timeout_do(void *arg) { #ifdef NEED_CURL_TIMER_CALLBACK BDRVCURLState *s = (BDRVCURLState *)arg; int running; if (!s->multi) { return; } curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running); curl_multi_check_completion(s); #else abort(); #endif } static CURLState *curl_init_state(BlockDriverState *bs, 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) { aio_poll(bdrv_get_aio_context(bs), true); } } while(!state); if (!state->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_SSL_VERIFYPEER, (long) s->sslverify); if (s->cookie) { curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie); } curl_easy_setopt(state->curl, CURLOPT_TIMEOUT, s->timeout); curl_easy_setopt(state->curl, CURLOPT_WRITEFUNCTION, (void *)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); curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1); /* Restrict supported protocols to avoid security issues in the more * obscure protocols. For example, do not allow POP3/SMTP/IMAP see * CVE-2013-0249. * * Restricting protocols is only supported from 7.19.4 upwards. */ #if LIBCURL_VERSION_NUM >= 0x071304 curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS); curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS); #endif #ifdef DEBUG_VERBOSE curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1); #endif } 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 void curl_parse_filename(const char *filename, QDict *options, Error **errp) { qdict_put(options, CURL_BLOCK_OPT_URL, qstring_from_str(filename)); } static void curl_detach_aio_context(BlockDriverState *bs) { BDRVCURLState *s = bs->opaque; int i; 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; } g_free(s->states[i].orig_buf); s->states[i].orig_buf = NULL; } if (s->multi) { curl_multi_cleanup(s->multi); s->multi = NULL; } timer_del(&s->timer); } static void curl_attach_aio_context(BlockDriverState *bs, AioContext *new_context) { BDRVCURLState *s = bs->opaque; aio_timer_init(new_context, &s->timer, QEMU_CLOCK_REALTIME, SCALE_NS, curl_multi_timeout_do, s); assert(!s->multi); s->multi = curl_multi_init(); s->aio_context = new_context; curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb); #ifdef NEED_CURL_TIMER_CALLBACK curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s); curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb); #endif } static QemuOptsList runtime_opts = { .name = "curl", .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head), .desc = { { .name = CURL_BLOCK_OPT_URL, .type = QEMU_OPT_STRING, .help = "URL to open", }, { .name = CURL_BLOCK_OPT_READAHEAD, .type = QEMU_OPT_SIZE, .help = "Readahead size", }, { .name = CURL_BLOCK_OPT_SSLVERIFY, .type = QEMU_OPT_BOOL, .help = "Verify SSL certificate" }, { .name = CURL_BLOCK_OPT_TIMEOUT, .type = QEMU_OPT_NUMBER, .help = "Curl timeout" }, { .name = CURL_BLOCK_OPT_COOKIE, .type = QEMU_OPT_STRING, .help = "Pass the cookie or list of cookies with each request" }, { /* end of list */ } }, }; static int curl_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVCURLState *s = bs->opaque; CURLState *state = NULL; QemuOpts *opts; Error *local_err = NULL; const char *file; const char *cookie; double d; static int inited = 0; if (flags & BDRV_O_RDWR) { error_setg(errp, "curl block device does not support writes"); return -EROFS; } opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort); qemu_opts_absorb_qdict(opts, options, &local_err); if (local_err) { error_propagate(errp, local_err); goto out_noclean; } s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD, READ_AHEAD_DEFAULT); if ((s->readahead_size & 0x1ff) != 0) { error_setg(errp, "HTTP_READAHEAD_SIZE %zd is not a multiple of 512", s->readahead_size); goto out_noclean; } s->timeout = qemu_opt_get_number(opts, CURL_BLOCK_OPT_TIMEOUT, CURL_TIMEOUT_DEFAULT); s->sslverify = qemu_opt_get_bool(opts, CURL_BLOCK_OPT_SSLVERIFY, true); cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE); s->cookie = g_strdup(cookie); file = qemu_opt_get(opts, CURL_BLOCK_OPT_URL); if (file == NULL) { error_setg(errp, "curl block driver requires an 'url' option"); goto out_noclean; } if (!inited) { curl_global_init(CURL_GLOBAL_ALL); inited = 1; } DPRINTF("CURL: Opening %s\n", file); s->aio_context = bdrv_get_aio_context(bs); s->url = g_strdup(file); state = curl_init_state(bs, s); if (!state) goto out_noclean; // Get file size s->accept_range = false; curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1); curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION, curl_header_cb); curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s); if (curl_easy_perform(state->curl)) goto out; curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d); if (d) s->len = (size_t)d; else if(!s->len) goto out; if ((!strncasecmp(s->url, "http://", strlen("http://")) || !strncasecmp(s->url, "https://", strlen("https://"))) && !s->accept_range) { pstrcpy(state->errmsg, CURL_ERROR_SIZE, "Server does not support 'range' (byte ranges)."); goto out; } DPRINTF("CURL: Size = %zd\n", s->len); curl_clean_state(state); curl_easy_cleanup(state->curl); state->curl = NULL; curl_attach_aio_context(bs, bdrv_get_aio_context(bs)); qemu_opts_del(opts); return 0; out: error_setg(errp, "CURL: Error opening file: %s", state->errmsg); curl_easy_cleanup(state->curl); state->curl = NULL; out_noclean: g_free(s->cookie); g_free(s->url); qemu_opts_del(opts); return -EINVAL; } static const AIOCBInfo curl_aiocb_info = { .aiocb_size = sizeof(CURLAIOCB), }; static void curl_readv_bh_cb(void *p) { CURLState *state; int running; CURLAIOCB *acb = p; BDRVCURLState *s = acb->common.bs->opaque; qemu_bh_delete(acb->bh); acb->bh = NULL; size_t start = acb->sector_num * SECTOR_SIZE; size_t end; // 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, acb->nb_sectors * SECTOR_SIZE, acb)) { case FIND_RET_OK: qemu_aio_unref(acb); // fall through case FIND_RET_WAIT: return; default: break; } // No cache found, so let's start a new request state = curl_init_state(acb->common.bs, s); if (!state) { acb->common.cb(acb->common.opaque, -EIO); qemu_aio_unref(acb); return; } acb->start = 0; acb->end = (acb->nb_sectors * SECTOR_SIZE); state->buf_off = 0; g_free(state->orig_buf); state->buf_start = start; state->buf_len = acb->end + s->readahead_size; end = MIN(start + state->buf_len, s->len) - 1; state->orig_buf = g_try_malloc(state->buf_len); if (state->buf_len && state->orig_buf == NULL) { curl_clean_state(state); acb->common.cb(acb->common.opaque, -ENOMEM); qemu_aio_unref(acb); return; } state->acb[0] = acb; snprintf(state->range, 127, "%zd-%zd", start, end); DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n", (acb->nb_sectors * SECTOR_SIZE), start, state->range); curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range); curl_multi_add_handle(s->multi, state->curl); /* Tell curl it needs to kick things off */ curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running); } static BlockAIOCB *curl_aio_readv(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockCompletionFunc *cb, void *opaque) { CURLAIOCB *acb; acb = qemu_aio_get(&curl_aiocb_info, bs, cb, opaque); acb->qiov = qiov; acb->sector_num = sector_num; acb->nb_sectors = nb_sectors; acb->bh = aio_bh_new(bdrv_get_aio_context(bs), curl_readv_bh_cb, acb); qemu_bh_schedule(acb->bh); return &acb->common; } static void curl_close(BlockDriverState *bs) { BDRVCURLState *s = bs->opaque; DPRINTF("CURL: Close\n"); curl_detach_aio_context(bs); g_free(s->cookie); g_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_parse_filename = curl_parse_filename, .bdrv_file_open = curl_open, .bdrv_close = curl_close, .bdrv_getlength = curl_getlength, .bdrv_aio_readv = curl_aio_readv, .bdrv_detach_aio_context = curl_detach_aio_context, .bdrv_attach_aio_context = curl_attach_aio_context, }; static BlockDriver bdrv_https = { .format_name = "https", .protocol_name = "https", .instance_size = sizeof(BDRVCURLState), .bdrv_parse_filename = curl_parse_filename, .bdrv_file_open = curl_open, .bdrv_close = curl_close, .bdrv_getlength = curl_getlength, .bdrv_aio_readv = curl_aio_readv, .bdrv_detach_aio_context = curl_detach_aio_context, .bdrv_attach_aio_context = curl_attach_aio_context, }; static BlockDriver bdrv_ftp = { .format_name = "ftp", .protocol_name = "ftp", .instance_size = sizeof(BDRVCURLState), .bdrv_parse_filename = curl_parse_filename, .bdrv_file_open = curl_open, .bdrv_close = curl_close, .bdrv_getlength = curl_getlength, .bdrv_aio_readv = curl_aio_readv, .bdrv_detach_aio_context = curl_detach_aio_context, .bdrv_attach_aio_context = curl_attach_aio_context, }; static BlockDriver bdrv_ftps = { .format_name = "ftps", .protocol_name = "ftps", .instance_size = sizeof(BDRVCURLState), .bdrv_parse_filename = curl_parse_filename, .bdrv_file_open = curl_open, .bdrv_close = curl_close, .bdrv_getlength = curl_getlength, .bdrv_aio_readv = curl_aio_readv, .bdrv_detach_aio_context = curl_detach_aio_context, .bdrv_attach_aio_context = curl_attach_aio_context, }; static BlockDriver bdrv_tftp = { .format_name = "tftp", .protocol_name = "tftp", .instance_size = sizeof(BDRVCURLState), .bdrv_parse_filename = curl_parse_filename, .bdrv_file_open = curl_open, .bdrv_close = curl_close, .bdrv_getlength = curl_getlength, .bdrv_aio_readv = curl_aio_readv, .bdrv_detach_aio_context = curl_detach_aio_context, .bdrv_attach_aio_context = curl_attach_aio_context, }; 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);