/*
* Copyright (c) Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stratosphere.hpp>
#include "lm_log_packet_parser.hpp"
namespace ams::lm::srv {
namespace {
const u8 *ParseUleb128(u64 *out, const u8 *cur, const u8 *end) {
u64 value = 0;
size_t shift = 0;
while (cur < end && shift + 7 <= BITSIZEOF(u64)) {
value |= static_cast<u64>(*cur & 0x7F) << shift;
if ((*cur & 0x80) == 0) {
*out = value;
return cur;
}
++cur;
shift += 7;
}
return end;
}
}
bool LogPacketParser::ParsePacket(const void *buffer, size_t buffer_size, ParsePacketCallback callback, void *arg) {
const u8 *cur = static_cast<const u8 *>(buffer);
const u8 *end = cur + buffer_size;
while (cur < end) {
/* Check that we can parse a header. */
size_t remaining_size = end - cur;
if (remaining_size < sizeof(impl::LogPacketHeader)) {
AMS_ASSERT(remaining_size >= sizeof(impl::LogPacketHeader));
return false;
}
/* Get the header. */
impl::LogPacketHeader header;
std::memcpy(std::addressof(header), cur, sizeof(header));
/* Advance past the header. */
cur += sizeof(header);
/* Check that we can parse the payload. */
const auto payload_size = header.GetPayloadSize();
remaining_size = end - cur;
if (remaining_size < payload_size) {
AMS_ASSERT(remaining_size >= payload_size);
return false;
}
/* Invoke the callback. */
if (!callback(header, cur, payload_size, arg)) {
return false;
}
/* Advance. */
cur += payload_size;
}
/* Check that we parsed all the data. */
AMS_ASSERT(cur == end);
return true;
}
bool LogPacketParser::ParseDataChunk(const void *payload, size_t payload_size, ParseDataChunkCallback callback, void *arg) {
const u8 *cur = static_cast<const u8 *>(payload);
const u8 *end = cur + payload_size;
while (cur < end) {
/* Get the key. */
u64 key;
const auto key_last = ParseUleb128(std::addressof(key), cur, end);
if (key_last >= end) {
return false;
}
cur = key_last + 1;
/* Get the size. */
u64 size;
const auto size_last = ParseUleb128(std::addressof(size), cur, end);
if (size_last >= end) {
return false;
}
cur = size_last + 1;
/* If we're in bounds, invoke the callback. */
if (cur + size <= end && !callback(static_cast<impl::LogDataChunkKey>(key), cur, size, arg)) {
return false;
}
cur += size;
}
return true;
}
bool LogPacketParser::FindDataChunk(const void **out, size_t *out_size, impl::LogDataChunkKey key, const void *buffer, size_t buffer_size) {
/* Create context for iteration. */
struct FindDataChunkContext {
const void *chunk;
size_t chunk_size;
bool found;
impl::LogDataChunkKey key;
} context = { nullptr, 0, false, key };
/* Find the chunk. */
LogPacketParser::ParsePacket(buffer, buffer_size, [](const impl::LogPacketHeader &header, const void *payload, size_t payload_size, void *arg) -> bool {
/* If the header isn't a header packet, continue. */
if (!header.IsHead()) {
return true;
}
return LogPacketParser::ParseDataChunk(payload, payload_size, [](impl::LogDataChunkKey cur_key, const void *chunk, size_t chunk_size, void *arg) -> bool {
/* Get the context. */
auto *context = static_cast<FindDataChunkContext *>(arg);
/* Check if we found the desired key. */
if (context->key == cur_key) {
context->chunk = chunk;
context->chunk_size = chunk_size;
context->found = true;
return false;
}
/* Otherwise, continue. */
return true;
}, arg);
}, std::addressof(context));
/* Write the chunk we found. */
if (context.found) {
*out = context.chunk;
*out_size = context.chunk_size;
return true;
} else {
return false;
}
}
size_t LogPacketParser::ParseModuleName(char *dst, size_t dst_size, const void *buffer, size_t buffer_size) {
/* Check pre-conditions. */
AMS_ASSERT(dst != nullptr);
AMS_ASSERT(dst_size > 0);
AMS_ASSERT(buffer != nullptr);
AMS_ASSERT(buffer_size > 0);
/* Find the relevant data chunk. */
const void *chunk;
size_t chunk_size;
const bool found = LogPacketParser::FindDataChunk(std::addressof(chunk), std::addressof(chunk_size), impl::LogDataChunkKey_ModuleName, buffer, buffer_size);
if (!found || chunk_size == 0) {
dst[0] = '\x00';
return 0;
}
/* Copy as much of the module name as we can. */
const size_t copy_size = std::min(chunk_size, dst_size - 1);
std::memcpy(dst, chunk, copy_size);
dst[copy_size] = '\x00';
return chunk_size;
}
void LogPacketParser::ParseTextLogWithContext(const void *buffer, size_t buffer_size, ParseTextLogCallback callback, void *arg) {
/* Declare context for inter-call storage. */
struct PreviousPacketContext {
u64 process_id;
u64 thread_id;
size_t carry_size;
bool ends_with_text_log;
};
AMS_FUNCTION_LOCAL_STATIC_CONSTINIT(PreviousPacketContext, s_previous_packet_context);
/* Get the packet header. */
auto *header = static_cast<const impl::LogPacketHeader *>(buffer);
auto *payload = static_cast<const char *>(buffer) + impl::LogPacketHeaderSize;
auto payload_size = buffer_size - impl::LogPacketHeaderSize;
/* Determine if the packet is a continuation. */
const bool is_continuation = !header->IsHead() && header->GetProcessId() == s_previous_packet_context.process_id && header->GetThreadId() == s_previous_packet_context.thread_id;
/* Require that the packet be a header or a continuation. */
if (!header->IsHead() && !is_continuation) {
return;
}
/* If the packet is a continuation, handle the leftover data. */
if (is_continuation && s_previous_packet_context.carry_size > 0) {
/* Invoke the callback on what we can. */
const size_t sendable = std::min(s_previous_packet_context.carry_size, payload_size);
if (s_previous_packet_context.ends_with_text_log) {
callback(payload, sendable, arg);
}
/* Advance the leftover data. */
s_previous_packet_context.carry_size -= sendable;
payload += sendable;
payload_size -= sendable;
}
/* If we've sent the whole payload, we're done. */
if (payload_size == 0) {
return;
}
/* Parse the payload. */
size_t carry_size = 0;
bool ends_with_text_log = false;
{
const u8 *cur = reinterpret_cast<const u8 *>(payload);
const u8 *end = cur + payload_size;
while (cur < end) {
/* Get the key. */
u64 key;
const auto key_last = ParseUleb128(std::addressof(key), cur, end);
if (key_last >= end) {
break;
}
cur = key_last + 1;
/* Get the size. */
u64 size;
const auto size_last = ParseUleb128(std::addressof(size), cur, end);
if (size_last >= end) {
break;
}
cur = size_last + 1;
/* Process the data. */
const bool is_text_log = static_cast<impl::LogDataChunkKey>(key) == impl::LogDataChunkKey_TextLog;
const size_t remaining = end - cur;
if (size >= remaining) {
carry_size = size - remaining;
ends_with_text_log = is_text_log;
}
if (is_text_log) {
const size_t sendable_size = std::min<size_t>(size, remaining);
callback(reinterpret_cast<const char *>(cur), sendable_size, arg);
}
cur += size;
}
}
/* If the packet isn't a tail packet, update the context. */
if (!header->IsTail()) {
s_previous_packet_context.process_id = header->GetProcessId();
s_previous_packet_context.thread_id = header->GetThreadId();
s_previous_packet_context.carry_size = carry_size;
s_previous_packet_context.ends_with_text_log = ends_with_text_log;
}
}
}