godot/core/io/packet_peer.cpp
Fabio Alessandrelli 534bf89976 PacketPeer use heap buffer for var encoding.
Used to allocate in stack (via alloca) which causes crashes when trying
to encode big variables.
The buffer grows as needed up to `encode_buffer_max_size` (which is
8MiB by default) and always in power of 2.
2020-01-19 11:49:10 +01:00

335 lines
11 KiB
C++

/*************************************************************************/
/* packet_peer.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* 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 "packet_peer.h"
#include "core/io/marshalls.h"
#include "core/project_settings.h"
/* helpers / binders */
PacketPeer::PacketPeer() :
last_get_error(OK),
allow_object_decoding(false),
encode_buffer_max_size(8 * 1024 * 1024) {
}
void PacketPeer::set_allow_object_decoding(bool p_enable) {
allow_object_decoding = p_enable;
}
bool PacketPeer::is_object_decoding_allowed() const {
return allow_object_decoding;
}
void PacketPeer::set_encode_buffer_max_size(int p_max_size) {
ERR_FAIL_COND_MSG(p_max_size < 1024, "Max encode buffer must be at least 1024 bytes");
ERR_FAIL_COND_MSG(p_max_size > 256 * 1024 * 1024, "Max encode buffer cannot exceed 256 MiB");
encode_buffer_max_size = next_power_of_2(p_max_size);
encode_buffer.resize(0);
}
int PacketPeer::get_encode_buffer_max_size() const {
return encode_buffer_max_size;
}
Error PacketPeer::get_packet_buffer(PoolVector<uint8_t> &r_buffer) {
const uint8_t *buffer;
int buffer_size;
Error err = get_packet(&buffer, buffer_size);
if (err)
return err;
r_buffer.resize(buffer_size);
if (buffer_size == 0)
return OK;
PoolVector<uint8_t>::Write w = r_buffer.write();
for (int i = 0; i < buffer_size; i++)
w[i] = buffer[i];
return OK;
}
Error PacketPeer::put_packet_buffer(const PoolVector<uint8_t> &p_buffer) {
int len = p_buffer.size();
if (len == 0)
return OK;
PoolVector<uint8_t>::Read r = p_buffer.read();
return put_packet(&r[0], len);
}
Error PacketPeer::get_var(Variant &r_variant, bool p_allow_objects) {
const uint8_t *buffer;
int buffer_size;
Error err = get_packet(&buffer, buffer_size);
if (err)
return err;
return decode_variant(r_variant, buffer, buffer_size, NULL, p_allow_objects || allow_object_decoding);
}
Error PacketPeer::put_var(const Variant &p_packet, bool p_full_objects) {
int len;
Error err = encode_variant(p_packet, NULL, len, p_full_objects || allow_object_decoding); // compute len first
if (err)
return err;
if (len == 0)
return OK;
ERR_FAIL_COND_V_MSG(len > encode_buffer_max_size, ERR_OUT_OF_MEMORY, "Failed to encode variant, encode size is bigger then encode_buffer_max_size. Consider raising it via 'set_encode_buffer_max_size'.");
if (unlikely(encode_buffer.size() < len)) {
encode_buffer.resize(0); // Avoid realloc
encode_buffer.resize(next_power_of_2(len));
}
PoolVector<uint8_t>::Write w = encode_buffer.write();
err = encode_variant(p_packet, w.ptr(), len, p_full_objects || allow_object_decoding);
ERR_FAIL_COND_V_MSG(err != OK, err, "Error when trying to encode Variant.");
return put_packet(w.ptr(), len);
}
Variant PacketPeer::_bnd_get_var(bool p_allow_objects) {
Variant var;
Error err = get_var(var, p_allow_objects);
ERR_FAIL_COND_V(err != OK, Variant());
return var;
}
Error PacketPeer::_put_packet(const PoolVector<uint8_t> &p_buffer) {
return put_packet_buffer(p_buffer);
}
PoolVector<uint8_t> PacketPeer::_get_packet() {
PoolVector<uint8_t> raw;
last_get_error = get_packet_buffer(raw);
return raw;
}
Error PacketPeer::_get_packet_error() const {
return last_get_error;
}
void PacketPeer::_bind_methods() {
ClassDB::bind_method(D_METHOD("get_var", "allow_objects"), &PacketPeer::_bnd_get_var, DEFVAL(false));
ClassDB::bind_method(D_METHOD("put_var", "var", "full_objects"), &PacketPeer::put_var, DEFVAL(false));
ClassDB::bind_method(D_METHOD("get_packet"), &PacketPeer::_get_packet);
ClassDB::bind_method(D_METHOD("put_packet", "buffer"), &PacketPeer::_put_packet);
ClassDB::bind_method(D_METHOD("get_packet_error"), &PacketPeer::_get_packet_error);
ClassDB::bind_method(D_METHOD("get_available_packet_count"), &PacketPeer::get_available_packet_count);
ClassDB::bind_method(D_METHOD("set_allow_object_decoding", "enable"), &PacketPeer::set_allow_object_decoding);
ClassDB::bind_method(D_METHOD("is_object_decoding_allowed"), &PacketPeer::is_object_decoding_allowed);
ClassDB::bind_method(D_METHOD("get_encode_buffer_max_size"), &PacketPeer::get_encode_buffer_max_size);
ClassDB::bind_method(D_METHOD("set_encode_buffer_max_size", "max_size"), &PacketPeer::set_encode_buffer_max_size);
ADD_PROPERTY(PropertyInfo(Variant::INT, "encode_buffer_max_size"), "set_encode_buffer_max_size", "get_encode_buffer_max_size");
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "allow_object_decoding"), "set_allow_object_decoding", "is_object_decoding_allowed");
};
/***************/
void PacketPeerStream::_set_stream_peer(REF p_peer) {
ERR_FAIL_COND_MSG(p_peer.is_null(), "It's not a reference to a valid Resource object.");
set_stream_peer(p_peer);
}
void PacketPeerStream::_bind_methods() {
ClassDB::bind_method(D_METHOD("set_stream_peer", "peer"), &PacketPeerStream::set_stream_peer);
ClassDB::bind_method(D_METHOD("get_stream_peer"), &PacketPeerStream::get_stream_peer);
ClassDB::bind_method(D_METHOD("set_input_buffer_max_size", "max_size_bytes"), &PacketPeerStream::set_input_buffer_max_size);
ClassDB::bind_method(D_METHOD("set_output_buffer_max_size", "max_size_bytes"), &PacketPeerStream::set_output_buffer_max_size);
ClassDB::bind_method(D_METHOD("get_input_buffer_max_size"), &PacketPeerStream::get_input_buffer_max_size);
ClassDB::bind_method(D_METHOD("get_output_buffer_max_size"), &PacketPeerStream::get_output_buffer_max_size);
ADD_PROPERTY(PropertyInfo(Variant::INT, "input_buffer_max_size"), "set_input_buffer_max_size", "get_input_buffer_max_size");
ADD_PROPERTY(PropertyInfo(Variant::INT, "output_buffer_max_size"), "set_output_buffer_max_size", "get_output_buffer_max_size");
ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "stream_peer", PROPERTY_HINT_RESOURCE_TYPE, "StreamPeer", 0), "set_stream_peer", "get_stream_peer");
}
Error PacketPeerStream::_poll_buffer() const {
ERR_FAIL_COND_V(peer.is_null(), ERR_UNCONFIGURED);
int read = 0;
ERR_FAIL_COND_V(input_buffer.size() < ring_buffer.space_left(), ERR_UNAVAILABLE);
Error err = peer->get_partial_data(input_buffer.ptrw(), ring_buffer.space_left(), read);
if (err)
return err;
if (read == 0)
return OK;
int w = ring_buffer.write(&input_buffer[0], read);
ERR_FAIL_COND_V(w != read, ERR_BUG);
return OK;
}
int PacketPeerStream::get_available_packet_count() const {
_poll_buffer();
uint32_t remaining = ring_buffer.data_left();
int ofs = 0;
int count = 0;
while (remaining >= 4) {
uint8_t lbuf[4];
ring_buffer.copy(lbuf, ofs, 4);
uint32_t len = decode_uint32(lbuf);
remaining -= 4;
ofs += 4;
if (len > remaining)
break;
remaining -= len;
ofs += len;
count++;
}
return count;
}
Error PacketPeerStream::get_packet(const uint8_t **r_buffer, int &r_buffer_size) {
ERR_FAIL_COND_V(peer.is_null(), ERR_UNCONFIGURED);
_poll_buffer();
int remaining = ring_buffer.data_left();
ERR_FAIL_COND_V(remaining < 4, ERR_UNAVAILABLE);
uint8_t lbuf[4];
ring_buffer.copy(lbuf, 0, 4);
remaining -= 4;
uint32_t len = decode_uint32(lbuf);
ERR_FAIL_COND_V(remaining < (int)len, ERR_UNAVAILABLE);
ERR_FAIL_COND_V(input_buffer.size() < (int)len, ERR_UNAVAILABLE);
ring_buffer.read(lbuf, 4); //get rid of first 4 bytes
ring_buffer.read(input_buffer.ptrw(), len); // read packet
*r_buffer = &input_buffer[0];
r_buffer_size = len;
return OK;
}
Error PacketPeerStream::put_packet(const uint8_t *p_buffer, int p_buffer_size) {
ERR_FAIL_COND_V(peer.is_null(), ERR_UNCONFIGURED);
Error err = _poll_buffer(); //won't hurt to poll here too
if (err)
return err;
if (p_buffer_size == 0)
return OK;
ERR_FAIL_COND_V(p_buffer_size < 0, ERR_INVALID_PARAMETER);
ERR_FAIL_COND_V(p_buffer_size + 4 > output_buffer.size(), ERR_INVALID_PARAMETER);
encode_uint32(p_buffer_size, output_buffer.ptrw());
uint8_t *dst = &output_buffer.write[4];
for (int i = 0; i < p_buffer_size; i++)
dst[i] = p_buffer[i];
return peer->put_data(&output_buffer[0], p_buffer_size + 4);
}
int PacketPeerStream::get_max_packet_size() const {
return output_buffer.size();
}
void PacketPeerStream::set_stream_peer(const Ref<StreamPeer> &p_peer) {
//ERR_FAIL_COND(p_peer.is_null());
if (p_peer.ptr() != peer.ptr()) {
ring_buffer.advance_read(ring_buffer.data_left()); // reset the ring buffer
};
peer = p_peer;
}
Ref<StreamPeer> PacketPeerStream::get_stream_peer() const {
return peer;
}
void PacketPeerStream::set_input_buffer_max_size(int p_max_size) {
ERR_FAIL_COND_MSG(p_max_size < 0, "Max size of input buffer size cannot be smaller than 0.");
//warning may lose packets
ERR_FAIL_COND_MSG(ring_buffer.data_left(), "Buffer in use, resizing would cause loss of data.");
ring_buffer.resize(nearest_shift(next_power_of_2(p_max_size + 4)) - 1);
input_buffer.resize(next_power_of_2(p_max_size + 4));
}
int PacketPeerStream::get_input_buffer_max_size() const {
return input_buffer.size() - 4;
}
void PacketPeerStream::set_output_buffer_max_size(int p_max_size) {
output_buffer.resize(next_power_of_2(p_max_size + 4));
}
int PacketPeerStream::get_output_buffer_max_size() const {
return output_buffer.size() - 4;
}
PacketPeerStream::PacketPeerStream() {
int rbsize = GLOBAL_GET("network/limits/packet_peer_stream/max_buffer_po2");
ring_buffer.resize(rbsize);
input_buffer.resize(1 << rbsize);
output_buffer.resize(1 << rbsize);
}