qemu/block/curl.c
Max Reitz 0f418a2076 curl: Disconnect sockets from CURLState
When a curl transfer is finished, that does not mean that CURL lets go
of all the sockets it used for it.  We therefore must not free a
CURLSocket object before CURL has invoked curl_sock_cb() to tell us to
remove it.  Otherwise, we may get a use-after-free, as described in this
bug report: https://bugs.launchpad.net/qemu/+bug/1916501

(Reproducer from that report:
  $ qemu-img convert -f qcow2 -O raw \
  https://download.cirros-cloud.net/0.4.0/cirros-0.4.0-x86_64-disk.img \
  out.img
)

(Alternatively, it might seem logical to force-drop all sockets that
have been used for a state when the respective transfer is done, kind of
like it is done now, but including unsetting the AIO handlers.
Unfortunately, doing so makes the driver just hang instead of crashing,
which seems to evidence that CURL still uses those sockets.)

Make the CURLSocket object independent of "its" CURLState by putting all
sockets into a hash table belonging to the BDRVCURLState instead of a
list that belongs to a CURLState.  Do not touch any sockets in
curl_clean_state().

Testing, it seems like all sockets are indeed gone by the time the curl
BDS is closed, so it seems like there really was no point in freeing any
socket just because a transfer is done.  libcurl does invoke
curl_sock_cb() with CURL_POLL_REMOVE for every socket it has.

Buglink: https://bugs.launchpad.net/qemu/+bug/1916501
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210309130541.37540-3-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2021-03-19 10:15:06 +01:00

1053 lines
30 KiB
C

/*
* 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_int.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qstring.h"
#include "crypto/secret.h"
#include <curl/curl.h>
#include "qemu/cutils.h"
#include "trace.h"
// #define DEBUG_VERBOSE
#define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
CURLPROTO_FTP | CURLPROTO_FTPS)
#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, false,
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;
CURLState *state = NULL;
CURLSocket *socket;
curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&state);
s = state->s;
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, false,
curl_multi_do, NULL, NULL, socket);
break;
case CURL_POLL_OUT:
aio_set_fd_handler(s->aio_context, fd, false,
NULL, curl_multi_do, NULL, socket);
break;
case CURL_POLL_INOUT:
aio_set_fd_handler(s->aio_context, fd, false,
curl_multi_do, curl_multi_do, NULL, socket);
break;
case CURL_POLL_REMOVE:
aio_set_fd_handler(s->aio_context, fd, false,
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 *header = (char *)ptr;
const char *end = header + realsize;
const char *accept_ranges = "accept-ranges:";
const char *bytes = "bytes";
if (realsize >= strlen(accept_ranges)
&& g_ascii_strncasecmp(header, accept_ranges,
strlen(accept_ranges)) == 0) {
char *p = strchr(header, ':') + 1;
/* Skip whitespace between the header name and value. */
while (p < end && *p && g_ascii_isspace(*p)) {
p++;
}
if (end - p >= strlen(bytes)
&& strncmp(p, bytes, strlen(bytes)) == 0) {
/* Check that there is nothing but whitespace after the value. */
p += strlen(bytes);
while (p < end && *p && g_ascii_isspace(*p)) {
p++;
}
if (p == end || !*p) {
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 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;
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);
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;
}
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);
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);
if (s->username) {
curl_easy_setopt(state->curl, CURLOPT_USERNAME, s->username);
}
if (s->password) {
curl_easy_setopt(state->curl, CURLOPT_PASSWORD, s->password);
}
if (s->proxyusername) {
curl_easy_setopt(state->curl,
CURLOPT_PROXYUSERNAME, s->proxyusername);
}
if (s->proxypassword) {
curl_easy_setopt(state->curl,
CURLOPT_PROXYPASSWORD, s->proxypassword);
}
/* 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 0;
}
/* 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_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;
double d;
const char *secretid;
const char *protocol_delimiter;
int ret;
ret = bdrv_apply_auto_read_only(bs, "curl driver does not support writes",
errp);
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) {
goto out;
}
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;
if (curl_easy_getinfo(state->curl, CURLINFO_CONTENT_LENGTH_DOWNLOAD, &d)) {
goto out;
}
/* Prior CURL 7.19.4 return value of 0 could mean that the file size is not
* know or the size is zero. From 7.19.4 CURL returns -1 if size is not
* known and zero if it is really zero-length file. */
#if LIBCURL_VERSION_NUM >= 0x071304
if (d < 0) {
pstrcpy(state->errmsg, CURL_ERROR_SIZE,
"Server didn't report file size.");
goto out;
}
#else
if (d <= 0) {
pstrcpy(state->errmsg, CURL_ERROR_SIZE,
"Unknown file size or zero-length file.");
goto out;
}
#endif
s->len = d;
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);
curl_drop_all_sockets(s->sockets);
g_hash_table_destroy(s->sockets);
qemu_opts_del(opts);
return -EINVAL;
}
static void curl_setup_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.
if (curl_find_buf(s, start, acb->bytes, acb)) {
goto out;
}
// 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 out;
}
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 out;
}
state->acb[0] = acb;
snprintf(state->range, 127, "%" PRIu64 "-%" PRIu64, start, end);
trace_curl_setup_preadv(acb->bytes, start, state->range);
curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
if (curl_multi_add_handle(s->multi, state->curl) != CURLM_OK) {
state->acb[0] = NULL;
acb->ret = -EIO;
curl_clean_state(state);
goto out;
}
/* Tell curl it needs to kick things off */
curl_multi_socket_action(s->multi, CURL_SOCKET_TIMEOUT, 0, &running);
out:
qemu_mutex_unlock(&s->mutex);
}
static int coroutine_fn curl_co_preadv(BlockDriverState *bs,
uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags)
{
CURLAIOCB acb = {
.co = qemu_coroutine_self(),
.ret = -EINPROGRESS,
.qiov = qiov,
.offset = offset,
.bytes = bytes
};
curl_setup_preadv(bs, &acb);
while (acb.ret == -EINPROGRESS) {
qemu_coroutine_yield();
}
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 curl_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_file_open = curl_open,
.bdrv_close = curl_close,
.bdrv_getlength = curl_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_file_open = curl_open,
.bdrv_close = curl_close,
.bdrv_getlength = curl_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_file_open = curl_open,
.bdrv_close = curl_close,
.bdrv_getlength = curl_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_file_open = curl_open,
.bdrv_close = curl_close,
.bdrv_getlength = curl_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);