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Fix handling of large compressed packets #6144

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6f7e1a4
Bug #80107 Add test for mysqli_query() fails for ~16 MB long query wh…
kocsismate Sep 15, 2020
70c4536
Fix handling of large compressed packets
nikic Sep 16, 2020
eb4e369
Check max_allowed_packet size
nikic Sep 16, 2020
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57 changes: 57 additions & 0 deletions ext/mysqli/tests/mysqli_real_connect_compression_error.phpt
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Original file line number Diff line number Diff line change
@@ -0,0 +1,57 @@
--TEST--
Bug #80107 mysqli_query() fails for ~16 MB long query when compression is enabled
--SKIPIF--
<?php
require_once('skipif.inc');
require_once('skipifemb.inc');
require_once("connect.inc");
$link = @my_mysqli_connect($host, $user, $passwd, $db, $port, $socket);
if (!$link) {
die(sprintf("skip Can't connect to MySQL Server - [%d] %s", mysqli_connect_errno(), mysqli_connect_error()));
}
$result = $link->query("SHOW VARIABLES LIKE 'max_allowed_packet'");
if ($result->fetch_assoc()['Value'] < 0xffffff) {
die('skip max_allowed_packet is less than 0xffffff');
}
?>
--FILE--
<?php

require_once("connect.inc");

$data_size = 16777174;

// Insert with compression disabled:

$mysqli = mysqli_init();
$result = my_mysqli_real_connect($mysqli, $host, $user, $passwd, $db, $port, $socket);
$mysqli->query("DROP TABLE IF EXISTS test");
$mysqli->query("CREATE TABLE test (`blob` LONGBLOB NOT NULL)");

$data = str_repeat("x", $data_size);
$mysqli->query("INSERT INTO $db.test(`blob`) VALUE ('$data')");

var_dump(mysqli_error_list($mysqli));
$mysqli->close();

// Insert with compression enabled:

$mysqli = mysqli_init();
$result = my_mysqli_real_connect($mysqli, $host, $user, $passwd, $db, $port, $socket, MYSQLI_CLIENT_COMPRESS);

$data = str_repeat("x", $data_size);
$mysqli->query("INSERT INTO $db.test(`blob`) VALUE ('$data')");

var_dump(mysqli_error_list($mysqli));
$mysqli->close();

?>
--CLEAN--
<?php
require_once("clean_table.inc");
?>
--EXPECT--
array(0) {
}
array(0) {
}
104 changes: 64 additions & 40 deletions ext/mysqlnd/mysqlnd_protocol_frame_codec.c
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Expand Up @@ -49,6 +49,56 @@ MYSQLND_METHOD(mysqlnd_pfc, reset)(MYSQLND_PFC * const pfc, MYSQLND_STATS * cons
#define RESTORE_HEADER_SIZE(buffer, safe_storage) STORE_HEADER_SIZE((safe_storage), (buffer))


static ssize_t write_compressed_packet(
const MYSQLND_PFC *pfc, MYSQLND_VIO *vio,
MYSQLND_STATS *conn_stats, MYSQLND_ERROR_INFO *error_info,
zend_uchar *uncompressed_payload, size_t to_be_sent, zend_uchar *compress_buf) {
DBG_ENTER("write_compressed_packet");
/* here we need to compress the data and then write it, first comes the compressed header */
size_t tmp_complen = to_be_sent;
size_t payload_size;
if (PASS == pfc->data->m.encode((compress_buf + COMPRESSED_HEADER_SIZE + MYSQLND_HEADER_SIZE), &tmp_complen,
uncompressed_payload, to_be_sent))
{
int3store(compress_buf + MYSQLND_HEADER_SIZE, to_be_sent);
payload_size = tmp_complen;
} else {
int3store(compress_buf + MYSQLND_HEADER_SIZE, 0);
memcpy(compress_buf + MYSQLND_HEADER_SIZE + COMPRESSED_HEADER_SIZE, uncompressed_payload, to_be_sent);
payload_size = to_be_sent;
}

int3store(compress_buf, payload_size);
int1store(compress_buf + 3, pfc->data->compressed_envelope_packet_no);
DBG_INF_FMT("writing "MYSQLND_SZ_T_SPEC" bytes to the network", payload_size + MYSQLND_HEADER_SIZE + COMPRESSED_HEADER_SIZE);

ssize_t bytes_sent = vio->data->m.network_write(vio, compress_buf, payload_size + MYSQLND_HEADER_SIZE + COMPRESSED_HEADER_SIZE, conn_stats, error_info);
pfc->data->compressed_envelope_packet_no++;
#ifdef WHEN_WE_NEED_TO_CHECK_WHETHER_COMPRESSION_WORKS_CORRECTLY
if (res == Z_OK) {
size_t decompressed_size = left + MYSQLND_HEADER_SIZE;
zend_uchar * decompressed_data = mnd_malloc(decompressed_size);
int error = pfc->data->m.decode(decompressed_data, decompressed_size,
compress_buf + MYSQLND_HEADER_SIZE + COMPRESSED_HEADER_SIZE, payload_size);
if (error == Z_OK) {
int i;
DBG_INF("success decompressing");
for (i = 0 ; i < decompressed_size; i++) {
if (i && (i % 30 == 0)) {
printf("\n\t\t");
}
printf("%.2X ", (int)*((char*)&(decompressed_data[i])));
DBG_INF_FMT("%.2X ", (int)*((char*)&(decompressed_data[i])));
}
} else {
DBG_INF("error decompressing");
}
mnd_free(decompressed_data);
}
#endif /* WHEN_WE_NEED_TO_CHECK_WHETHER_COMPRESSION_WORKS_CORRECTLY */
DBG_RETURN(bytes_sent);
}

/* {{{ mysqlnd_pfc::send */
/*
IMPORTANT : It's expected that buffer has place in the beginning for MYSQLND_HEADER_SIZE !!!!
Expand Down Expand Up @@ -90,53 +140,27 @@ MYSQLND_METHOD(mysqlnd_pfc, send)(MYSQLND_PFC * const pfc, MYSQLND_VIO * const v
DBG_INF_FMT("packet_no=%u", pfc->data->packet_no);
#ifdef MYSQLND_COMPRESSION_ENABLED
if (pfc->data->compressed == TRUE) {
/* here we need to compress the data and then write it, first comes the compressed header */
size_t tmp_complen = to_be_sent;
size_t payload_size;
zend_uchar * uncompressed_payload = p; /* should include the header */

STORE_HEADER_SIZE(safe_storage, uncompressed_payload);
int3store(uncompressed_payload, to_be_sent);
int1store(uncompressed_payload + 3, pfc->data->packet_no);
if (PASS == pfc->data->m.encode((compress_buf + COMPRESSED_HEADER_SIZE + MYSQLND_HEADER_SIZE), &tmp_complen,
uncompressed_payload, to_be_sent + MYSQLND_HEADER_SIZE))
{
int3store(compress_buf + MYSQLND_HEADER_SIZE, to_be_sent + MYSQLND_HEADER_SIZE);
payload_size = tmp_complen;
if (to_be_sent <= MYSQLND_MAX_PACKET_SIZE - MYSQLND_HEADER_SIZE) {
bytes_sent = write_compressed_packet(
pfc, vio, conn_stats, error_info,
uncompressed_payload, to_be_sent + MYSQLND_HEADER_SIZE, compress_buf);
} else {
int3store(compress_buf + MYSQLND_HEADER_SIZE, 0);
memcpy(compress_buf + MYSQLND_HEADER_SIZE + COMPRESSED_HEADER_SIZE, uncompressed_payload, to_be_sent + MYSQLND_HEADER_SIZE);
payload_size = to_be_sent + MYSQLND_HEADER_SIZE;
/* The uncompressed size including the header would overflow. Split into two
* compressed packets. The size of the first one is relatively arbitrary here. */
const size_t split_off_bytes = 8192;
bytes_sent = write_compressed_packet(
pfc, vio, conn_stats, error_info,
uncompressed_payload, split_off_bytes, compress_buf);
bytes_sent = write_compressed_packet(
pfc, vio, conn_stats, error_info,
uncompressed_payload + split_off_bytes,
to_be_sent + MYSQLND_HEADER_SIZE - split_off_bytes, compress_buf);
}
RESTORE_HEADER_SIZE(uncompressed_payload, safe_storage);

int3store(compress_buf, payload_size);
int1store(compress_buf + 3, pfc->data->packet_no);
DBG_INF_FMT("writing "MYSQLND_SZ_T_SPEC" bytes to the network", payload_size + MYSQLND_HEADER_SIZE + COMPRESSED_HEADER_SIZE);
bytes_sent = vio->data->m.network_write(vio, compress_buf, payload_size + MYSQLND_HEADER_SIZE + COMPRESSED_HEADER_SIZE, conn_stats, error_info);
pfc->data->compressed_envelope_packet_no++;
#ifdef WHEN_WE_NEED_TO_CHECK_WHETHER_COMPRESSION_WORKS_CORRECTLY
if (res == Z_OK) {
size_t decompressed_size = left + MYSQLND_HEADER_SIZE;
zend_uchar * decompressed_data = mnd_malloc(decompressed_size);
int error = pfc->data->m.decode(decompressed_data, decompressed_size,
compress_buf + MYSQLND_HEADER_SIZE + COMPRESSED_HEADER_SIZE, payload_size);
if (error == Z_OK) {
int i;
DBG_INF("success decompressing");
for (i = 0 ; i < decompressed_size; i++) {
if (i && (i % 30 == 0)) {
printf("\n\t\t");
}
printf("%.2X ", (int)*((char*)&(decompressed_data[i])));
DBG_INF_FMT("%.2X ", (int)*((char*)&(decompressed_data[i])));
}
} else {
DBG_INF("error decompressing");
}
mnd_free(decompressed_data);
}
#endif /* WHEN_WE_NEED_TO_CHECK_WHETHER_COMPRESSION_WORKS_CORRECTLY */
} else
#endif /* MYSQLND_COMPRESSION_ENABLED */
{
Expand Down