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qemu/block/curl.c
Hanna Czenczek 53d5c7ffac curl: Fix coroutine waking 
If we wake a coroutine from a different context, we must ensure that it
will yield exactly once (now or later), awaiting that wake.

curl’s current .ret == -EINPROGRESS loop may lead to the coroutine not
yielding if the request finishes before the loop gets run.  To fix it,
we must drop the loop and yield exactly once, if we need to yield.

Finding out that latter part ("if we need to yield") makes it a bit
complicated: Requests may be served from a cache internal to the curl
block driver, or fail before being submitted.  In these cases, we must
not yield.  However, if we find a matching but still ongoing request in
the cache, we will have to await that, i.e. still yield.

To address this, move the yield inside of the respective functions:
- Inside of curl_find_buf() when awaiting ongoing concurrent requests,
- Inside of curl_setup_preadv() when having created a new request.

Rename curl_setup_preadv() to curl_do_preadv() to reflect this.

(Can be reproduced with multiqueue by adding a usleep(100000) before the
`while (acb.ret == -EINPROGRESS)` loop.)

Also, add a comment why aio_co_wake() is safe regardless of whether the
coroutine and curl_multi_check_completion() run in the same context.

Cc: qemu-stable@nongnu.org
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-ID: <20251110154854.151484-6-hreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2025-11-18 18:01:50 +01:00

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/*
* 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/osdep.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "qemu/module.h"
#include "qemu/option.h"
#include "block/block-io.h"
#include "block/block_int.h"
#include "qobject/qdict.h"
#include "qobject/qstring.h"
#include "crypto/secret.h"
#include <curl/curl.h>
#include "qemu/cutils.h"
#include "trace.h"
// #define DEBUG_VERBOSE
/* CURL 7.85.0 switches to a string based API for specifying
* the desired protocols.
*/
#if LIBCURL_VERSION_NUM >= 0x075500
#define PROTOCOLS "HTTP,HTTPS,FTP,FTPS"
#else
#define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
CURLPROTO_FTP | CURLPROTO_FTPS)
#endif
#define CURL_NUM_STATES 8
#define CURL_NUM_ACB 8
#define CURL_TIMEOUT_MAX 10000
#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"
#define CURL_BLOCK_OPT_COOKIE_SECRET "cookie-secret"
#define CURL_BLOCK_OPT_USERNAME "username"
#define CURL_BLOCK_OPT_PASSWORD_SECRET "password-secret"
#define CURL_BLOCK_OPT_PROXY_USERNAME "proxy-username"
#define CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET "proxy-password-secret"
#define CURL_BLOCK_OPT_READAHEAD_DEFAULT (256 * 1024)
#define CURL_BLOCK_OPT_SSLVERIFY_DEFAULT true
#define CURL_BLOCK_OPT_TIMEOUT_DEFAULT 5
struct BDRVCURLState;
struct CURLState;
static bool libcurl_initialized;
typedef struct CURLAIOCB {
Coroutine *co;
QEMUIOVector *qiov;
uint64_t offset;
uint64_t bytes;
int ret;
size_t start;
size_t end;
} CURLAIOCB;
typedef struct CURLSocket {
int fd;
struct BDRVCURLState *s;
} CURLSocket;
typedef struct CURLState
{
struct BDRVCURLState *s;
CURLAIOCB *acb[CURL_NUM_ACB];
CURL *curl;
char *orig_buf;
uint64_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;
uint64_t len;
CURLState states[CURL_NUM_STATES];
GHashTable *sockets; /* GINT_TO_POINTER(fd) -> socket */
char *url;
size_t readahead_size;
bool sslverify;
uint64_t timeout;
char *cookie;
bool accept_range;
AioContext *aio_context;
QemuMutex mutex;
CoQueue free_state_waitq;
char *username;
char *password;
char *proxyusername;
char *proxypassword;
} BDRVCURLState;
static void curl_clean_state(CURLState *s);
static void curl_multi_do(void *arg);
static gboolean curl_drop_socket(void *key, void *value, void *opaque)
{
CURLSocket *socket = value;
BDRVCURLState *s = socket->s;
aio_set_fd_handler(s->aio_context, socket->fd,
NULL, NULL, NULL, NULL, NULL);
return true;
}
static void curl_drop_all_sockets(GHashTable *sockets)
{
g_hash_table_foreach_remove(sockets, curl_drop_socket, NULL);
}
/* Called from curl_multi_do_locked, with s->mutex held. */
static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
{
BDRVCURLState *s = opaque;
trace_curl_timer_cb(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;
}
/* Called from curl_multi_do_locked, with s->mutex held. */
static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
void *userp, void *sp)
{
BDRVCURLState *s = userp;
CURLSocket *socket;
socket = g_hash_table_lookup(s->sockets, GINT_TO_POINTER(fd));
if (!socket) {
socket = g_new0(CURLSocket, 1);
socket->fd = fd;
socket->s = s;
g_hash_table_insert(s->sockets, GINT_TO_POINTER(fd), socket);
}
trace_curl_sock_cb(action, (int)fd);
switch (action) {
case CURL_POLL_IN:
aio_set_fd_handler(s->aio_context, fd,
curl_multi_do, NULL, NULL, NULL, socket);
break;
case CURL_POLL_OUT:
aio_set_fd_handler(s->aio_context, fd,
NULL, curl_multi_do, NULL, NULL, socket);
break;
case CURL_POLL_INOUT:
aio_set_fd_handler(s->aio_context, fd,
curl_multi_do, curl_multi_do,
NULL, NULL, socket);
break;
case CURL_POLL_REMOVE:
aio_set_fd_handler(s->aio_context, fd,
NULL, NULL, NULL, NULL, NULL);
break;
}
if (action == CURL_POLL_REMOVE) {
g_hash_table_remove(s->sockets, GINT_TO_POINTER(fd));
}
return 0;
}
/* Called from curl_multi_do_locked, with s->mutex held. */
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 *p = ptr;
const char *end = p + realsize;
const char *t = "accept-ranges : bytes "; /* A lowercase template */
/* check if header matches the "t" template */
for (;;) {
if (*t == ' ') { /* space in t matches any amount of isspace in p */
if (p < end && g_ascii_isspace(*p)) {
++p;
} else {
++t;
}
} else if (*t && p < end && *t == g_ascii_tolower(*p)) {
++p, ++t;
} else {
break;
}
}
if (!*t && p == end) { /* if we managed to reach ends of both strings */
s->accept_range = true;
}
return realsize;
}
/* Called from curl_multi_do_locked, with s->mutex held. */
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;
trace_curl_read_cb(realsize);
if (!s || !s->orig_buf) {
goto read_end;
}
if (s->buf_off >= s->buf_len) {
/* buffer full, read nothing */
goto read_end;
}
realsize = MIN(realsize, s->buf_len - s->buf_off);
memcpy(s->orig_buf + s->buf_off, ptr, realsize);
s->buf_off += realsize;
read_end:
/* curl will error out if we do not return this value */
return size * nmemb;
}
/* Called with s->mutex held. */
static bool coroutine_fn
curl_find_buf(BDRVCURLState *s, uint64_t start, uint64_t len, CURLAIOCB *acb)
{
int i;
uint64_t end = start + len;
uint64_t clamped_end = MIN(end, s->len);
uint64_t clamped_len = clamped_end - start;
for (i=0; i<CURL_NUM_STATES; i++) {
CURLState *state = &s->states[i];
uint64_t buf_end = (state->buf_start + state->buf_off);
uint64_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) &&
(clamped_end >= state->buf_start) &&
(clamped_end <= buf_end))
{
char *buf = state->orig_buf + (start - state->buf_start);
qemu_iovec_from_buf(acb->qiov, 0, buf, clamped_len);
if (clamped_len < len) {
qemu_iovec_memset(acb->qiov, clamped_len, 0, len - clamped_len);
}
acb->ret = 0;
return true;
}
// Wait for unfinished chunks
if (state->in_use &&
(start >= state->buf_start) &&
(start <= buf_fend) &&
(clamped_end >= state->buf_start) &&
(clamped_end <= buf_fend))
{
int j;
acb->start = start - state->buf_start;
acb->end = acb->start + clamped_len;
for (j=0; j<CURL_NUM_ACB; j++) {
if (!state->acb[j]) {
state->acb[j] = acb;
/* Await ongoing request */
qemu_mutex_unlock(&s->mutex);
qemu_coroutine_yield();
qemu_mutex_lock(&s->mutex);
return true;
}
}
}
}
return false;
}
/* Called with s->mutex held. */
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) {
int i;
CURLState *state = NULL;
bool error = msg->data.result != CURLE_OK;
curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE,
(char **)&state);
if (error) {
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;
}
if (!error) {
/* Assert that we have read all data */
assert(state->buf_off >= acb->end);
qemu_iovec_from_buf(acb->qiov, 0,
state->orig_buf + acb->start,
acb->end - acb->start);
if (acb->end - acb->start < acb->bytes) {
size_t offset = acb->end - acb->start;
qemu_iovec_memset(acb->qiov, offset, 0,
acb->bytes - offset);
}
}
acb->ret = error ? -EIO : 0;
state->acb[i] = NULL;
qemu_mutex_unlock(&s->mutex);
/*
* Current AioContext is the BDS context, which may or may not
* be the request (coroutine) context.
* - If it is, the coroutine must have yielded or the FD handler
* (curl_multi_do()/curl_multi_timeout_do()) could not have
* been called and we would not be here
* - If it is not, it doesn't matter whether it has already
* yielded or not; it will be scheduled once it does yield
* So aio_co_wake() is safe to call.
*/
aio_co_wake(acb->co);
qemu_mutex_lock(&s->mutex);
}
curl_clean_state(state);
break;
}
}
}
/* Called with s->mutex held. */
static void curl_multi_do_locked(CURLSocket *socket)
{
BDRVCURLState *s = socket->s;
int running;
int r;
if (!s->multi) {
return;
}
do {
r = curl_multi_socket_action(s->multi, socket->fd, 0, &running);
} while (r == CURLM_CALL_MULTI_PERFORM);
}
static void curl_multi_do(void *arg)
{
CURLSocket *socket = arg;
BDRVCURLState *s = socket->s;
qemu_mutex_lock(&s->mutex);
curl_multi_do_locked(socket);
curl_multi_check_completion(s);
qemu_mutex_unlock(&s->mutex);
}
static void curl_multi_timeout_do(void *arg)
{
BDRVCURLState *s = (BDRVCURLState *)arg;
int running;
if (!s->multi) {
return;
}
qemu_mutex_lock(&s->mutex);
curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
curl_multi_check_completion(s);
qemu_mutex_unlock(&s->mutex);
}
/* Called with s->mutex held. */
static CURLState *curl_find_state(BDRVCURLState *s)
{
CURLState *state = NULL;
int i;
for (i = 0; i < CURL_NUM_STATES; i++) {
if (!s->states[i].in_use) {
state = &s->states[i];
state->in_use = 1;
break;
}
}
return state;
}
static int curl_init_state(BDRVCURLState *s, CURLState *state)
{
if (!state->curl) {
state->curl = curl_easy_init();
if (!state->curl) {
return -EIO;
}
if (curl_easy_setopt(state->curl, CURLOPT_URL, s->url) ||
curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYPEER,
(long) s->sslverify) ||
curl_easy_setopt(state->curl, CURLOPT_SSL_VERIFYHOST,
s->sslverify ? 2L : 0L)) {
goto err;
}
if (s->cookie) {
if (curl_easy_setopt(state->curl, CURLOPT_COOKIE, s->cookie)) {
goto err;
}
}
if (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, 1L) ||
curl_easy_setopt(state->curl, CURLOPT_FOLLOWLOCATION, 1L) ||
curl_easy_setopt(state->curl, CURLOPT_NOSIGNAL, 1L) ||
curl_easy_setopt(state->curl, CURLOPT_ERRORBUFFER, state->errmsg) ||
curl_easy_setopt(state->curl, CURLOPT_FAILONERROR, 1L)) {
goto err;
}
if (s->username) {
if (curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username)) {
goto err;
}
}
if (s->password) {
if (curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password)) {
goto err;
}
}
if (s->proxyusername) {
if (curl_easy_setopt(state->curl,
CURLOPT_PROXYUSERNAME, s->proxyusername)) {
goto err;
}
}
if (s->proxypassword) {
if (curl_easy_setopt(state->curl,
CURLOPT_PROXYPASSWORD, s->proxypassword)) {
goto err;
}
}
/* 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. Note:
* version 7.85.0 deprecates CURLOPT_*PROTOCOLS in favour of a string
* based CURLOPT_*PROTOCOLS_STR API.
*/
#if LIBCURL_VERSION_NUM >= 0x075500
if (curl_easy_setopt(state->curl,
CURLOPT_PROTOCOLS_STR, PROTOCOLS) ||
curl_easy_setopt(state->curl,
CURLOPT_REDIR_PROTOCOLS_STR, PROTOCOLS)) {
goto err;
}
#else
if (curl_easy_setopt(state->curl, CURLOPT_PROTOCOLS, PROTOCOLS) ||
curl_easy_setopt(state->curl, CURLOPT_REDIR_PROTOCOLS, PROTOCOLS)) {
goto err;
}
#endif
#ifdef DEBUG_VERBOSE
if (curl_easy_setopt(state->curl, CURLOPT_VERBOSE, 1L)) {
goto err;
}
#endif
}
state->s = s;
return 0;
err:
curl_easy_cleanup(state->curl);
state->curl = NULL;
return -EIO;
}
/* Called with s->mutex held. */
static void curl_clean_state(CURLState *s)
{
int j;
for (j = 0; j < CURL_NUM_ACB; j++) {
assert(!s->acb[j]);
}
if (s->s->multi)
curl_multi_remove_handle(s->s->multi, s->curl);
s->in_use = 0;
qemu_co_enter_next(&s->s->free_state_waitq, &s->s->mutex);
}
static void curl_parse_filename(const char *filename, QDict *options,
Error **errp)
{
qdict_put_str(options, CURL_BLOCK_OPT_URL, filename);
}
static void curl_detach_aio_context(BlockDriverState *bs)
{
BDRVCURLState *s = bs->opaque;
int i;
WITH_QEMU_LOCK_GUARD(&s->mutex) {
curl_drop_all_sockets(s->sockets);
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_SOCKETDATA, s);
curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
}
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"
},
{
.name = CURL_BLOCK_OPT_COOKIE_SECRET,
.type = QEMU_OPT_STRING,
.help = "ID of secret used as cookie passed with each request"
},
{
.name = CURL_BLOCK_OPT_USERNAME,
.type = QEMU_OPT_STRING,
.help = "Username for HTTP auth"
},
{
.name = CURL_BLOCK_OPT_PASSWORD_SECRET,
.type = QEMU_OPT_STRING,
.help = "ID of secret used as password for HTTP auth",
},
{
.name = CURL_BLOCK_OPT_PROXY_USERNAME,
.type = QEMU_OPT_STRING,
.help = "Username for HTTP proxy auth"
},
{
.name = CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
.type = QEMU_OPT_STRING,
.help = "ID of secret used as password for HTTP proxy auth",
},
{ /* end of list */ }
},
};
static int curl_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
BDRVCURLState *s = bs->opaque;
CURLState *state = NULL;
QemuOpts *opts;
const char *file;
const char *cookie;
const char *cookie_secret;
/* CURL >= 7.55.0 uses curl_off_t for content length instead of a double */
#if LIBCURL_VERSION_NUM >= 0x073700
curl_off_t cl;
#else
double cl;
#endif
const char *secretid;
const char *protocol_delimiter;
int ret;
bdrv_graph_rdlock_main_loop();
ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
errp);
bdrv_graph_rdunlock_main_loop();
if (ret < 0) {
return ret;
}
if (!libcurl_initialized) {
ret = curl_global_init(CURL_GLOBAL_ALL);
if (ret) {
error_setg(errp, "libcurl initialization failed with %d", ret);
return -EIO;
}
libcurl_initialized = true;
}
qemu_mutex_init(&s->mutex);
opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
if (!qemu_opts_absorb_qdict(opts, options, errp)) {
goto out_noclean;
}
s->readahead_size = qemu_opt_get_size(opts, CURL_BLOCK_OPT_READAHEAD,
CURL_BLOCK_OPT_READAHEAD_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_BLOCK_OPT_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,
CURL_BLOCK_OPT_SSLVERIFY_DEFAULT);
cookie = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE);
cookie_secret = qemu_opt_get(opts, CURL_BLOCK_OPT_COOKIE_SECRET);
if (cookie && cookie_secret) {
error_setg(errp,
"curl driver cannot handle both cookie and cookie secret");
goto out_noclean;
}
if (cookie_secret) {
s->cookie = qcrypto_secret_lookup_as_utf8(cookie_secret, errp);
if (!s->cookie) {
goto out_noclean;
}
} else {
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 (!strstart(file, bs->drv->protocol_name, &protocol_delimiter) ||
!strstart(protocol_delimiter, "://", NULL))
{
error_setg(errp, "%s curl driver cannot handle the URL '%s' (does not "
"start with '%s://')", bs->drv->protocol_name, file,
bs->drv->protocol_name);
goto out_noclean;
}
s->username = g_strdup(qemu_opt_get(opts, CURL_BLOCK_OPT_USERNAME));
secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PASSWORD_SECRET);
if (secretid) {
s->password = qcrypto_secret_lookup_as_utf8(secretid, errp);
if (!s->password) {
goto out_noclean;
}
}
s->proxyusername = g_strdup(
qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_USERNAME));
secretid = qemu_opt_get(opts, CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET);
if (secretid) {
s->proxypassword = qcrypto_secret_lookup_as_utf8(secretid, errp);
if (!s->proxypassword) {
goto out_noclean;
}
}
trace_curl_open(file);
qemu_co_queue_init(&s->free_state_waitq);
s->aio_context = bdrv_get_aio_context(bs);
s->url = g_strdup(file);
s->sockets = g_hash_table_new_full(NULL, NULL, NULL, g_free);
qemu_mutex_lock(&s->mutex);
state = curl_find_state(s);
qemu_mutex_unlock(&s->mutex);
if (!state) {
goto out_noclean;
}
// Get file size
if (curl_init_state(s, state) < 0) {
pstrcpy(state->errmsg, CURL_ERROR_SIZE,
"curl library initialization failed.");
goto out;
}
s->accept_range = false;
if (curl_easy_setopt(state->curl, CURLOPT_NOBODY, 1L) ||
curl_easy_setopt(state->curl, CURLOPT_HEADERFUNCTION, curl_header_cb) ||
curl_easy_setopt(state->curl, CURLOPT_HEADERDATA, s)) {
pstrcpy(state->errmsg, CURL_ERROR_SIZE,
"curl library initialization failed.");
goto out;
}
if (curl_easy_perform(state->curl))
goto out;
/* CURL 7.55.0 deprecates CURLINFO_CONTENT_LENGTH_DOWNLOAD in favour of
* the *_T version which returns a more sensible type for content length.
*/
#if LIBCURL_VERSION_NUM >= 0x073700
if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD_T, &cl)) {
goto out;
}
#else
if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &cl)) {
goto out;
}
#endif
if (cl < 0) {
pstrcpy(state->errmsg, CURL_ERROR_SIZE,
"Server didn't report file size.");
goto out;
}
s->len = cl;
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;
}
trace_curl_open_size(s->len);
qemu_mutex_lock(&s->mutex);
curl_clean_state(state);
qemu_mutex_unlock(&s->mutex);
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:
qemu_mutex_destroy(&s->mutex);
g_free(s->cookie);
g_free(s->url);
g_free(s->username);
g_free(s->proxyusername);
g_free(s->proxypassword);
if (s->sockets) {
curl_drop_all_sockets(s->sockets);
g_hash_table_destroy(s->sockets);
}
qemu_opts_del(opts);
return -EINVAL;
}
static void coroutine_fn curl_do_preadv(BlockDriverState *bs, CURLAIOCB *acb)
{
CURLState *state;
int running;
BDRVCURLState *s = bs->opaque;
uint64_t start = acb->offset;
uint64_t end;
qemu_mutex_lock(&s->mutex);
/*
* In case we have the requested data already (e.g. read-ahead),
* we can just call the callback and be done. This may have to
* await an ongoing request, in which case it itself will yield.
*/
if (curl_find_buf(s, start, acb->bytes, acb)) {
goto dont_yield;
}
// No cache found, so let's start a new request
for (;;) {
state = curl_find_state(s);
if (state) {
break;
}
qemu_co_queue_wait(&s->free_state_waitq, &s->mutex);
}
if (curl_init_state(s, state) < 0) {
curl_clean_state(state);
acb->ret = -EIO;
goto dont_yield;
}
acb->start = 0;
acb->end = MIN(acb->bytes, s->len - start);
state->buf_off = 0;
g_free(state->orig_buf);
state->buf_start = start;
state->buf_len = MIN(acb->end + s->readahead_size, s->len - start);
end = start + state->buf_len - 1;
state->orig_buf = g_try_malloc(state->buf_len);
if (state->buf_len && state->orig_buf == NULL) {
curl_clean_state(state);
acb->ret = -ENOMEM;
goto dont_yield;
}
state->acb[0] = acb;
snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
trace_curl_setup_preadv(acb->bytes, start, state->range);
if (curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range) ||
curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
state->acb[0] = NULL;
acb->ret = -EIO;
curl_clean_state(state);
goto dont_yield;
}
/* Tell curl it needs to kick things off */
curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
qemu_mutex_unlock(&s->mutex);
qemu_coroutine_yield();
return;
dont_yield:
qemu_mutex_unlock(&s->mutex);
}
static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
int64_t offset, int64_t bytes, QEMUIOVector *qiov,
BdrvRequestFlags flags)
{
CURLAIOCB acb = {
.co = qemu_coroutine_self(),
.ret = -EINPROGRESS,
.qiov = qiov,
.offset = offset,
.bytes = bytes
};
curl_do_preadv(bs, &acb);
return acb.ret;
}
static void curl_close(BlockDriverState *bs)
{
BDRVCURLState *s = bs->opaque;
trace_curl_close();
curl_detach_aio_context(bs);
qemu_mutex_destroy(&s->mutex);
g_hash_table_destroy(s->sockets);
g_free(s->cookie);
g_free(s->url);
g_free(s->username);
g_free(s->proxyusername);
g_free(s->proxypassword);
}
static int64_t coroutine_fn curl_co_getlength(BlockDriverState *bs)
{
BDRVCURLState *s = bs->opaque;
return s->len;
}
static void curl_refresh_filename(BlockDriverState *bs)
{
BDRVCURLState *s = bs->opaque;
/* "readahead" and "timeout" do not change the guest-visible data,
* so ignore them */
if (s->sslverify != CURL_BLOCK_OPT_SSLVERIFY_DEFAULT ||
s->cookie || s->username || s->password || s->proxyusername ||
s->proxypassword)
{
return;
}
pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), s->url);
}
static const char *const curl_strong_runtime_opts[] = {
CURL_BLOCK_OPT_URL,
CURL_BLOCK_OPT_SSLVERIFY,
CURL_BLOCK_OPT_COOKIE,
CURL_BLOCK_OPT_COOKIE_SECRET,
CURL_BLOCK_OPT_USERNAME,
CURL_BLOCK_OPT_PASSWORD_SECRET,
CURL_BLOCK_OPT_PROXY_USERNAME,
CURL_BLOCK_OPT_PROXY_PASSWORD_SECRET,
NULL
};
static BlockDriver bdrv_http = {
.format_name = "http",
.protocol_name = "http",
.instance_size = sizeof(BDRVCURLState),
.bdrv_parse_filename = curl_parse_filename,
.bdrv_open = curl_open,
.bdrv_close = curl_close,
.bdrv_co_getlength = curl_co_getlength,
.bdrv_co_preadv = curl_co_preadv,
.bdrv_detach_aio_context = curl_detach_aio_context,
.bdrv_attach_aio_context = curl_attach_aio_context,
.bdrv_refresh_filename = curl_refresh_filename,
.strong_runtime_opts = curl_strong_runtime_opts,
};
static BlockDriver bdrv_https = {
.format_name = "https",
.protocol_name = "https",
.instance_size = sizeof(BDRVCURLState),
.bdrv_parse_filename = curl_parse_filename,
.bdrv_open = curl_open,
.bdrv_close = curl_close,
.bdrv_co_getlength = curl_co_getlength,
.bdrv_co_preadv = curl_co_preadv,
.bdrv_detach_aio_context = curl_detach_aio_context,
.bdrv_attach_aio_context = curl_attach_aio_context,
.bdrv_refresh_filename = curl_refresh_filename,
.strong_runtime_opts = curl_strong_runtime_opts,
};
static BlockDriver bdrv_ftp = {
.format_name = "ftp",
.protocol_name = "ftp",
.instance_size = sizeof(BDRVCURLState),
.bdrv_parse_filename = curl_parse_filename,
.bdrv_open = curl_open,
.bdrv_close = curl_close,
.bdrv_co_getlength = curl_co_getlength,
.bdrv_co_preadv = curl_co_preadv,
.bdrv_detach_aio_context = curl_detach_aio_context,
.bdrv_attach_aio_context = curl_attach_aio_context,
.bdrv_refresh_filename = curl_refresh_filename,
.strong_runtime_opts = curl_strong_runtime_opts,
};
static BlockDriver bdrv_ftps = {
.format_name = "ftps",
.protocol_name = "ftps",
.instance_size = sizeof(BDRVCURLState),
.bdrv_parse_filename = curl_parse_filename,
.bdrv_open = curl_open,
.bdrv_close = curl_close,
.bdrv_co_getlength = curl_co_getlength,
.bdrv_co_preadv = curl_co_preadv,
.bdrv_detach_aio_context = curl_detach_aio_context,
.bdrv_attach_aio_context = curl_attach_aio_context,
.bdrv_refresh_filename = curl_refresh_filename,
.strong_runtime_opts = curl_strong_runtime_opts,
};
static void curl_block_init(void)
{
bdrv_register(&bdrv_http);
bdrv_register(&bdrv_https);
bdrv_register(&bdrv_ftp);
bdrv_register(&bdrv_ftps);
}
block_init(curl_block_init);
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