Add qemu 2.4.0

Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>

1 files changed, 825 insertions, 0 deletions

diff --git a/qemu/block/curl.c b/qemu/block/curl.c
new file mode 100644
index 000000000..032cc8ae2
--- /dev/null
+++ b/qemu/block/curl.c
@@ -0,0 +1,825 @@
+/*
+ * 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 "qemu/error-report.h"
+#include "block/block_int.h"
+#include "qapi/qmp/qbool.h"
+#include "qapi/qmp/qstring.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 CURL_TIMEOUT_MAX 10000
+
+#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;
+    uint64_t 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;
+                static int errcount = 100;
+
+                /* Don't lose the original error message from curl, since
+                 * it contains extra data.
+                 */
+                if (errcount > 0) {
+                    error_report("curl: %s", state->errmsg);
+                    if (--errcount == 0) {
+                        error_report("curl: further errors suppressed");
+                    }
+                }
+
+                for (i = 0; i < CURL_NUM_ACB; i++) {
+                    CURLAIOCB *acb = state->acb[i];
+
+                    if (acb == NULL) {
+                        continue;
+                    }
+
+                    acb->common.cb(acb->common.opaque, -EPROTO);
+                    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, (long)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);
+    if (s->timeout > CURL_TIMEOUT_MAX) {
+        error_setg(errp, "timeout parameter is too large or negative");
+        goto out_noclean;
+    }
+
+    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);