//===-- GDBRemoteCommunication.cpp ------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "GDBRemoteCommunication.h"
// C Includes
#include <limits.h>
#include <string.h>
#include <sys/stat.h>
// C++ Includes
// Other libraries and framework includes
#include "lldb/Core/ConnectionFileDescriptor.h"
#include "lldb/Core/Log.h"
#include "lldb/Core/StreamFile.h"
#include "lldb/Core/StreamString.h"
#include "lldb/Host/FileSpec.h"
#include "lldb/Host/Host.h"
#include "lldb/Host/TimeValue.h"
#include "lldb/Target/Process.h"
// Project includes
#include "ProcessGDBRemoteLog.h"
#define DEBUGSERVER_BASENAME "debugserver"
using namespace lldb;
using namespace lldb_private;
GDBRemoteCommunication::History::History (uint32_t size) :
m_packets(),
m_curr_idx (0),
m_total_packet_count (0),
m_dumped_to_log (false)
{
m_packets.resize(size);
}
GDBRemoteCommunication::History::~History ()
{
}
void
GDBRemoteCommunication::History::AddPacket (char packet_char,
PacketType type,
uint32_t bytes_transmitted)
{
const size_t size = m_packets.size();
if (size > 0)
{
const uint32_t idx = GetNextIndex();
m_packets[idx].packet.assign (1, packet_char);
m_packets[idx].type = type;
m_packets[idx].bytes_transmitted = bytes_transmitted;
m_packets[idx].packet_idx = m_total_packet_count;
m_packets[idx].tid = Host::GetCurrentThreadID();
}
}
void
GDBRemoteCommunication::History::AddPacket (const std::string &src,
uint32_t src_len,
PacketType type,
uint32_t bytes_transmitted)
{
const size_t size = m_packets.size();
if (size > 0)
{
const uint32_t idx = GetNextIndex();
m_packets[idx].packet.assign (src, 0, src_len);
m_packets[idx].type = type;
m_packets[idx].bytes_transmitted = bytes_transmitted;
m_packets[idx].packet_idx = m_total_packet_count;
m_packets[idx].tid = Host::GetCurrentThreadID();
}
}
void
GDBRemoteCommunication::History::Dump (lldb_private::Stream &strm) const
{
const uint32_t size = GetNumPacketsInHistory ();
const uint32_t first_idx = GetFirstSavedPacketIndex ();
const uint32_t stop_idx = m_curr_idx + size;
for (uint32_t i = first_idx; i < stop_idx; ++i)
{
const uint32_t idx = NormalizeIndex (i);
const Entry &entry = m_packets[idx];
if (entry.type == ePacketTypeInvalid || entry.packet.empty())
break;
strm.Printf ("history[%u] tid=0x%4.4" PRIx64 " <%4u> %s packet: %s\n",
entry.packet_idx,
entry.tid,
entry.bytes_transmitted,
(entry.type == ePacketTypeSend) ? "send" : "read",
entry.packet.c_str());
}
}
void
GDBRemoteCommunication::History::Dump (lldb_private::Log *log) const
{
if (log && !m_dumped_to_log)
{
m_dumped_to_log = true;
const uint32_t size = GetNumPacketsInHistory ();
const uint32_t first_idx = GetFirstSavedPacketIndex ();
const uint32_t stop_idx = m_curr_idx + size;
for (uint32_t i = first_idx; i < stop_idx; ++i)
{
const uint32_t idx = NormalizeIndex (i);
const Entry &entry = m_packets[idx];
if (entry.type == ePacketTypeInvalid || entry.packet.empty())
break;
log->Printf ("history[%u] tid=0x%4.4" PRIx64 " <%4u> %s packet: %s",
entry.packet_idx,
entry.tid,
entry.bytes_transmitted,
(entry.type == ePacketTypeSend) ? "send" : "read",
entry.packet.c_str());
}
}
}
//----------------------------------------------------------------------
// GDBRemoteCommunication constructor
//----------------------------------------------------------------------
GDBRemoteCommunication::GDBRemoteCommunication(const char *comm_name,
const char *listener_name,
bool is_platform) :
Communication(comm_name),
#ifdef LLDB_CONFIGURATION_DEBUG
m_packet_timeout (1000),
#else
m_packet_timeout (1),
#endif
m_sequence_mutex (Mutex::eMutexTypeRecursive),
m_public_is_running (false),
m_private_is_running (false),
m_history (512),
m_send_acks (true),
m_is_platform (is_platform),
m_listen_thread (LLDB_INVALID_HOST_THREAD),
m_listen_url ()
{
}
//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
GDBRemoteCommunication::~GDBRemoteCommunication()
{
if (IsConnected())
{
Disconnect();
}
}
char
GDBRemoteCommunication::CalculcateChecksum (const char *payload, size_t payload_length)
{
int checksum = 0;
for (size_t i = 0; i < payload_length; ++i)
checksum += payload[i];
return checksum & 255;
}
size_t
GDBRemoteCommunication::SendAck ()
{
Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS));
ConnectionStatus status = eConnectionStatusSuccess;
char ch = '+';
const size_t bytes_written = Write (&ch, 1, status, NULL);
if (log)
log->Printf ("<%4" PRIu64 "> send packet: %c", (uint64_t)bytes_written, ch);
m_history.AddPacket (ch, History::ePacketTypeSend, bytes_written);
return bytes_written;
}
size_t
GDBRemoteCommunication::SendNack ()
{
Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS));
ConnectionStatus status = eConnectionStatusSuccess;
char ch = '-';
const size_t bytes_written = Write (&ch, 1, status, NULL);
if (log)
log->Printf("<%4" PRIu64 "> send packet: %c", (uint64_t)bytes_written, ch);
m_history.AddPacket (ch, History::ePacketTypeSend, bytes_written);
return bytes_written;
}
GDBRemoteCommunication::PacketResult
GDBRemoteCommunication::SendPacket (const char *payload, size_t payload_length)
{
Mutex::Locker locker(m_sequence_mutex);
return SendPacketNoLock (payload, payload_length);
}
GDBRemoteCommunication::PacketResult
GDBRemoteCommunication::SendPacketNoLock (const char *payload, size_t payload_length)
{
if (IsConnected())
{
StreamString packet(0, 4, eByteOrderBig);
packet.PutChar('$');
packet.Write (payload, payload_length);
packet.PutChar('#');
packet.PutHex8(CalculcateChecksum (payload, payload_length));
Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS));
ConnectionStatus status = eConnectionStatusSuccess;
size_t bytes_written = Write (packet.GetData(), packet.GetSize(), status, NULL);
if (log)
{
// If logging was just enabled and we have history, then dump out what
// we have to the log so we get the historical context. The Dump() call that
// logs all of the packet will set a boolean so that we don't dump this more
// than once
if (!m_history.DidDumpToLog ())
m_history.Dump (log);
log->Printf("<%4" PRIu64 "> send packet: %.*s", (uint64_t)bytes_written, (int)packet.GetSize(), packet.GetData());
}
m_history.AddPacket (packet.GetString(), packet.GetSize(), History::ePacketTypeSend, bytes_written);
if (bytes_written == packet.GetSize())
{
if (GetSendAcks ())
return GetAck ();
else
return PacketResult::Success;
}
else
{
if (log)
log->Printf ("error: failed to send packet: %.*s", (int)packet.GetSize(), packet.GetData());
}
}
return PacketResult::ErrorSendFailed;
}
GDBRemoteCommunication::PacketResult
GDBRemoteCommunication::GetAck ()
{
StringExtractorGDBRemote packet;
PacketResult result = WaitForPacketWithTimeoutMicroSecondsNoLock (packet, GetPacketTimeoutInMicroSeconds ());
if (result == PacketResult::Success)
{
if (packet.GetResponseType() == StringExtractorGDBRemote::ResponseType::eAck)
return PacketResult::Success;
else
return PacketResult::ErrorSendAck;
}
return result;
}
bool
GDBRemoteCommunication::GetSequenceMutex (Mutex::Locker& locker, const char *failure_message)
{
if (IsRunning())
return locker.TryLock (m_sequence_mutex, failure_message);
locker.Lock (m_sequence_mutex);
return true;
}
bool
GDBRemoteCommunication::WaitForNotRunningPrivate (const TimeValue *timeout_ptr)
{
return m_private_is_running.WaitForValueEqualTo (false, timeout_ptr, NULL);
}
GDBRemoteCommunication::PacketResult
GDBRemoteCommunication::WaitForPacketWithTimeoutMicroSecondsNoLock (StringExtractorGDBRemote &packet, uint32_t timeout_usec)
{
uint8_t buffer[8192];
Error error;
Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS | GDBR_LOG_VERBOSE));
// Check for a packet from our cache first without trying any reading...
if (CheckForPacket (NULL, 0, packet))
return PacketResult::Success;
bool timed_out = false;
bool disconnected = false;
while (IsConnected() && !timed_out)
{
lldb::ConnectionStatus status = eConnectionStatusNoConnection;
size_t bytes_read = Read (buffer, sizeof(buffer), timeout_usec, status, &error);
if (log)
log->Printf ("%s: Read (buffer, (sizeof(buffer), timeout_usec = 0x%x, status = %s, error = %s) => bytes_read = %" PRIu64,
__PRETTY_FUNCTION__,
timeout_usec,
Communication::ConnectionStatusAsCString (status),
error.AsCString(),
(uint64_t)bytes_read);
if (bytes_read > 0)
{
if (CheckForPacket (buffer, bytes_read, packet))
return PacketResult::Success;
}
else
{
switch (status)
{
case eConnectionStatusTimedOut:
timed_out = true;
break;
case eConnectionStatusSuccess:
//printf ("status = success but error = %s\n", error.AsCString("<invalid>"));
break;
case eConnectionStatusEndOfFile:
case eConnectionStatusNoConnection:
case eConnectionStatusLostConnection:
case eConnectionStatusError:
disconnected = true;
Disconnect();
break;
}
}
}
packet.Clear ();
if (disconnected)
return PacketResult::ErrorDisconnected;
if (timed_out)
return PacketResult::ErrorReplyTimeout;
else
return PacketResult::ErrorReplyFailed;
}
bool
GDBRemoteCommunication::CheckForPacket (const uint8_t *src, size_t src_len, StringExtractorGDBRemote &packet)
{
// Put the packet data into the buffer in a thread safe fashion
Mutex::Locker locker(m_bytes_mutex);
Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS));
if (src && src_len > 0)
{
if (log && log->GetVerbose())
{
StreamString s;
log->Printf ("GDBRemoteCommunication::%s adding %u bytes: %.*s",
__FUNCTION__,
(uint32_t)src_len,
(uint32_t)src_len,
src);
}
m_bytes.append ((const char *)src, src_len);
}
// Parse up the packets into gdb remote packets
if (!m_bytes.empty())
{
// end_idx must be one past the last valid packet byte. Start
// it off with an invalid value that is the same as the current
// index.
size_t content_start = 0;
size_t content_length = 0;
size_t total_length = 0;
size_t checksum_idx = std::string::npos;
switch (m_bytes[0])
{
case '+': // Look for ack
case '-': // Look for cancel
case '\x03': // ^C to halt target
content_length = total_length = 1; // The command is one byte long...
break;
case '$':
// Look for a standard gdb packet?
{
size_t hash_pos = m_bytes.find('#');
if (hash_pos != std::string::npos)
{
if (hash_pos + 2 < m_bytes.size())
{
checksum_idx = hash_pos + 1;
// Skip the dollar sign
content_start = 1;
// Don't include the # in the content or the $ in the content length
content_length = hash_pos - 1;
total_length = hash_pos + 3; // Skip the # and the two hex checksum bytes
}
else
{
// Checksum bytes aren't all here yet
content_length = std::string::npos;
}
}
}
break;
default:
{
// We have an unexpected byte and we need to flush all bad
// data that is in m_bytes, so we need to find the first
// byte that is a '+' (ACK), '-' (NACK), \x03 (CTRL+C interrupt),
// or '$' character (start of packet header) or of course,
// the end of the data in m_bytes...
const size_t bytes_len = m_bytes.size();
bool done = false;
uint32_t idx;
for (idx = 1; !done && idx < bytes_len; ++idx)
{
switch (m_bytes[idx])
{
case '+':
case '-':
case '\x03':
case '$':
done = true;
break;
default:
break;
}
}
if (log)
log->Printf ("GDBRemoteCommunication::%s tossing %u junk bytes: '%.*s'",
__FUNCTION__, idx, idx, m_bytes.c_str());
m_bytes.erase(0, idx);
}
break;
}
if (content_length == std::string::npos)
{
packet.Clear();
return false;
}
else if (total_length > 0)
{
// We have a valid packet...
assert (content_length <= m_bytes.size());
assert (total_length <= m_bytes.size());
assert (content_length <= total_length);
bool success = true;
std::string &packet_str = packet.GetStringRef();
if (log)
{
// If logging was just enabled and we have history, then dump out what
// we have to the log so we get the historical context. The Dump() call that
// logs all of the packet will set a boolean so that we don't dump this more
// than once
if (!m_history.DidDumpToLog ())
m_history.Dump (log);
log->Printf("<%4" PRIu64 "> read packet: %.*s", (uint64_t)total_length, (int)(total_length), m_bytes.c_str());
}
m_history.AddPacket (m_bytes.c_str(), total_length, History::ePacketTypeRecv, total_length);
// Clear packet_str in case there is some existing data in it.
packet_str.clear();
// Copy the packet from m_bytes to packet_str expanding the
// run-length encoding in the process.
// Reserve enough byte for the most common case (no RLE used)
packet_str.reserve(m_bytes.length());
for (std::string::const_iterator c = m_bytes.begin() + content_start; c != m_bytes.begin() + content_start + content_length; ++c)
{
if (*c == '*')
{
// '*' indicates RLE. Next character will give us the
// repeat count and previous character is what is to be
// repeated.
char char_to_repeat = packet_str.back();
// Number of time the previous character is repeated
int repeat_count = *++c + 3 - ' ';
// We have the char_to_repeat and repeat_count. Now push
// it in the packet.
for (int i = 0; i < repeat_count; ++i)
packet_str.push_back(char_to_repeat);
}
else if (*c == 0x7d)
{
// 0x7d is the escape character. The next character is to
// be XOR'd with 0x20.
char escapee = *++c ^ 0x20;
packet_str.push_back(escapee);
}
else
{
packet_str.push_back(*c);
}
}
if (m_bytes[0] == '$')
{
assert (checksum_idx < m_bytes.size());
if (::isxdigit (m_bytes[checksum_idx+0]) ||
::isxdigit (m_bytes[checksum_idx+1]))
{
if (GetSendAcks ())
{
const char *packet_checksum_cstr = &m_bytes[checksum_idx];
char packet_checksum = strtol (packet_checksum_cstr, NULL, 16);
char actual_checksum = CalculcateChecksum (packet_str.c_str(), packet_str.size());
success = packet_checksum == actual_checksum;
if (!success)
{
if (log)
log->Printf ("error: checksum mismatch: %.*s expected 0x%2.2x, got 0x%2.2x",
(int)(total_length),
m_bytes.c_str(),
(uint8_t)packet_checksum,
(uint8_t)actual_checksum);
}
// Send the ack or nack if needed
if (!success)
SendNack();
else
SendAck();
}
}
else
{
success = false;
if (log)
log->Printf ("error: invalid checksum in packet: '%s'\n", m_bytes.c_str());
}
}
m_bytes.erase(0, total_length);
packet.SetFilePos(0);
return success;
}
}
packet.Clear();
return false;
}
Error
GDBRemoteCommunication::StartListenThread (const char *hostname, uint16_t port)
{
Error error;
if (IS_VALID_LLDB_HOST_THREAD(m_listen_thread))
{
error.SetErrorString("listen thread already running");
}
else
{
char listen_url[512];
if (hostname && hostname[0])
snprintf(listen_url, sizeof(listen_url), "listen://%s:%i", hostname, port);
else
snprintf(listen_url, sizeof(listen_url), "listen://%i", port);
m_listen_url = listen_url;
SetConnection(new ConnectionFileDescriptor());
m_listen_thread = Host::ThreadCreate (listen_url, GDBRemoteCommunication::ListenThread, this, &error);
}
return error;
}
bool
GDBRemoteCommunication::JoinListenThread ()
{
if (IS_VALID_LLDB_HOST_THREAD(m_listen_thread))
{
Host::ThreadJoin(m_listen_thread, NULL, NULL);
m_listen_thread = LLDB_INVALID_HOST_THREAD;
}
return true;
}
lldb::thread_result_t
GDBRemoteCommunication::ListenThread (lldb::thread_arg_t arg)
{
GDBRemoteCommunication *comm = (GDBRemoteCommunication *)arg;
Error error;
ConnectionFileDescriptor *connection = (ConnectionFileDescriptor *)comm->GetConnection ();
if (connection)
{
// Do the listen on another thread so we can continue on...
if (connection->Connect(comm->m_listen_url.c_str(), &error) != eConnectionStatusSuccess)
comm->SetConnection(NULL);
}
return NULL;
}
Error
GDBRemoteCommunication::StartDebugserverProcess (const char *hostname,
uint16_t in_port,
lldb_private::ProcessLaunchInfo &launch_info,
uint16_t &out_port)
{
out_port = in_port;
Error error;
// If we locate debugserver, keep that located version around
static FileSpec g_debugserver_file_spec;
char debugserver_path[PATH_MAX];
FileSpec &debugserver_file_spec = launch_info.GetExecutableFile();
// Always check to see if we have an environment override for the path
// to the debugserver to use and use it if we do.
const char *env_debugserver_path = getenv("LLDB_DEBUGSERVER_PATH");
if (env_debugserver_path)
debugserver_file_spec.SetFile (env_debugserver_path, false);
else
debugserver_file_spec = g_debugserver_file_spec;
bool debugserver_exists = debugserver_file_spec.Exists();
if (!debugserver_exists)
{
// The debugserver binary is in the LLDB.framework/Resources
// directory.
if (Host::GetLLDBPath (ePathTypeSupportExecutableDir, debugserver_file_spec))
{
debugserver_file_spec.GetFilename().SetCString(DEBUGSERVER_BASENAME);
debugserver_exists = debugserver_file_spec.Exists();
if (debugserver_exists)
{
g_debugserver_file_spec = debugserver_file_spec;
}
else
{
g_debugserver_file_spec.Clear();
debugserver_file_spec.Clear();
}
}
}
if (debugserver_exists)
{
debugserver_file_spec.GetPath (debugserver_path, sizeof(debugserver_path));
Args &debugserver_args = launch_info.GetArguments();
debugserver_args.Clear();
char arg_cstr[PATH_MAX];
// Start args with "debugserver /file/path -r --"
debugserver_args.AppendArgument(debugserver_path);
// If a host and port is supplied then use it
char host_and_port[128];
if (hostname)
{
snprintf (host_and_port, sizeof(host_and_port), "%s:%u", hostname, in_port);
debugserver_args.AppendArgument(host_and_port);
}
else
{
host_and_port[0] = '\0';
}
// use native registers, not the GDB registers
debugserver_args.AppendArgument("--native-regs");
// make debugserver run in its own session so signals generated by
// special terminal key sequences (^C) don't affect debugserver
debugserver_args.AppendArgument("--setsid");
char named_pipe_path[PATH_MAX];
named_pipe_path[0] = '\0';
bool listen = false;
if (host_and_port[0])
{
// Create a temporary file to get the stdout/stderr and redirect the
// output of the command into this file. We will later read this file
// if all goes well and fill the data into "command_output_ptr"
if (in_port == 0)
{
// Binding to port zero, we need to figure out what port it ends up
// using using a named pipe...
FileSpec tmpdir_file_spec;
if (Host::GetLLDBPath (ePathTypeLLDBTempSystemDir, tmpdir_file_spec))
{
tmpdir_file_spec.GetFilename().SetCString("debugserver-named-pipe.XXXXXX");
strncpy(named_pipe_path, tmpdir_file_spec.GetPath().c_str(), sizeof(named_pipe_path));
}
else
{
strncpy(named_pipe_path, "/tmp/debugserver-named-pipe.XXXXXX", sizeof(named_pipe_path));
}
if (::mktemp (named_pipe_path))
{
#if defined(_MSC_VER)
if ( false )
#else
if (::mkfifo(named_pipe_path, 0600) == 0)
#endif
{
debugserver_args.AppendArgument("--named-pipe");
debugserver_args.AppendArgument(named_pipe_path);
}
}
}
else
{
listen = true;
}
}
else
{
// No host and port given, so lets listen on our end and make the debugserver
// connect to us..
error = StartListenThread ("localhost", 0);
if (error.Fail())
return error;
ConnectionFileDescriptor *connection = (ConnectionFileDescriptor *)GetConnection ();
out_port = connection->GetBoundPort(3);
assert (out_port != 0);
char port_cstr[32];
snprintf(port_cstr, sizeof(port_cstr), "localhost:%i", out_port);
// Send the host and port down that debugserver and specify an option
// so that it connects back to the port we are listening to in this process
debugserver_args.AppendArgument("--reverse-connect");
debugserver_args.AppendArgument(port_cstr);
}
const char *env_debugserver_log_file = getenv("LLDB_DEBUGSERVER_LOG_FILE");
if (env_debugserver_log_file)
{
::snprintf (arg_cstr, sizeof(arg_cstr), "--log-file=%s", env_debugserver_log_file);
debugserver_args.AppendArgument(arg_cstr);
}
const char *env_debugserver_log_flags = getenv("LLDB_DEBUGSERVER_LOG_FLAGS");
if (env_debugserver_log_flags)
{
::snprintf (arg_cstr, sizeof(arg_cstr), "--log-flags=%s", env_debugserver_log_flags);
debugserver_args.AppendArgument(arg_cstr);
}
// Close STDIN, STDOUT and STDERR. We might need to redirect them
// to "/dev/null" if we run into any problems.
launch_info.AppendCloseFileAction (STDIN_FILENO);
launch_info.AppendCloseFileAction (STDOUT_FILENO);
launch_info.AppendCloseFileAction (STDERR_FILENO);
error = Host::LaunchProcess(launch_info);
if (named_pipe_path[0])
{
File name_pipe_file;
error = name_pipe_file.Open(named_pipe_path, File::eOpenOptionRead);
if (error.Success())
{
char port_cstr[256];
port_cstr[0] = '\0';
size_t num_bytes = sizeof(port_cstr);
error = name_pipe_file.Read(port_cstr, num_bytes);
assert (error.Success());
assert (num_bytes > 0 && port_cstr[num_bytes-1] == '\0');
out_port = Args::StringToUInt32(port_cstr, 0);
name_pipe_file.Close();
}
Host::Unlink(named_pipe_path);
}
else if (listen)
{
}
else
{
// Make sure we actually connect with the debugserver...
JoinListenThread();
}
}
else
{
error.SetErrorStringWithFormat ("unable to locate " DEBUGSERVER_BASENAME );
}
return error;
}
void
GDBRemoteCommunication::DumpHistory(Stream &strm)
{
m_history.Dump (strm);
}