llvm-project/lldb/source/Core/ConnectionMachPort.cpp

//===-- ConnectionMachPort.cpp ----------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#if defined(__APPLE__)

#include "lldb/Core/ConnectionMachPort.h"

// C Includes
#include <servers/bootstrap.h>

// C++ Includes
// Other libraries and framework includes
// Project includes
#include "lldb/lldb-private-log.h"
#include "lldb/Core/Communication.h"
#include "lldb/Core/Log.h"

using namespace lldb;
using namespace lldb_private;

struct MessageType
{
    mach_msg_header_t head;
    ConnectionMachPort::PayloadType payload;
};



ConnectionMachPort::ConnectionMachPort () :
    Connection(),
    m_task(mach_task_self()),
    m_port(MACH_PORT_TYPE_NONE)
{
}

ConnectionMachPort::~ConnectionMachPort ()
{
    Disconnect (NULL);
}

bool
ConnectionMachPort::IsConnected () const
{
    return  m_port != MACH_PORT_TYPE_NONE;
}

ConnectionStatus
ConnectionMachPort::Connect (const char *s, Error *error_ptr)
{
    if (IsConnected())
    {
        if (error_ptr)
            error_ptr->SetErrorString ("already connected");
        return eConnectionStatusError;
    }
    
    if (s == NULL || s[0] == '\0')
    {
        if (error_ptr)
            error_ptr->SetErrorString ("empty connect URL");
        return eConnectionStatusError;
    }
    
    ConnectionStatus status = eConnectionStatusError;
    
    if (strncmp (s, "bootstrap-checkin://", strlen("bootstrap-checkin://")))
    {
        s += strlen("bootstrap-checkin://");
        
        if (*s)
        {
            status = BootstrapCheckIn (s, error_ptr);
        }
        else
        {
            if (error_ptr)
                error_ptr->SetErrorString ("bootstrap port name is empty");
        }
    }
    else if (strncmp (s, "bootstrap-lookup://", strlen("bootstrap-lookup://")))
    {
        s += strlen("bootstrap-lookup://");
        if (*s)
        {
            status = BootstrapLookup (s, error_ptr);
        }
        else
        {
            if (error_ptr)
                error_ptr->SetErrorString ("bootstrap port name is empty");
        }
    }
    else
    {
        if (error_ptr)
            error_ptr->SetErrorStringWithFormat ("unsupported connection URL: '%s'", s);   
    }


    if (status == eConnectionStatusSuccess)
    {
        if (error_ptr)
            error_ptr->Clear();
    }
    else
    {
        Disconnect(NULL);
    }
        
    return status;
}

ConnectionStatus
ConnectionMachPort::BootstrapCheckIn (const char *port, Error *error_ptr)
{
    mach_port_t bootstrap_port = MACH_PORT_TYPE_NONE;
    
    /* Getting bootstrap server port */
    kern_return_t kret = task_get_bootstrap_port(mach_task_self(), &bootstrap_port);
    if (kret == KERN_SUCCESS) 
    {
        name_t port_name;
        int len = snprintf(port_name, sizeof(port_name), "%s", port);
        if (len < sizeof(port_name))
        {
            kret = ::bootstrap_check_in (bootstrap_port, 
                                         port_name, 
                                         &m_port);
        }
        else
        {
            Disconnect(NULL);
            if (error_ptr)
                error_ptr->SetErrorString ("bootstrap is too long");
            return eConnectionStatusError;
        }
    }
    
    if (kret != KERN_SUCCESS)
    {
        Disconnect(NULL);
        if (error_ptr)
            error_ptr->SetError (kret, eErrorTypeMachKernel);
        return eConnectionStatusError;
    }
    return eConnectionStatusSuccess;
}

lldb::ConnectionStatus
ConnectionMachPort::BootstrapLookup (const char *port, 
                                     Error *error_ptr)
{
    name_t port_name;

    if (port && port[0])
    {
        if (::snprintf (port_name, sizeof (port_name), "%s", port) >= sizeof (port_name))
        {
            if (error_ptr)
                error_ptr->SetErrorString ("port netname is too long");
            return eConnectionStatusError;
        }
    }
    else
    {
        if (error_ptr)
            error_ptr->SetErrorString ("empty port netname");
        return eConnectionStatusError;
    }

    mach_port_t bootstrap_port = MACH_PORT_TYPE_NONE;
    
    /* Getting bootstrap server port */
    kern_return_t kret = task_get_bootstrap_port(mach_task_self(), &bootstrap_port);
    if (kret == KERN_SUCCESS) 
    {
        kret = ::bootstrap_look_up (bootstrap_port, 
                                    port_name, 
                                    &m_port);
    }

    if (kret != KERN_SUCCESS)
    {
        if (error_ptr)
            error_ptr->SetError (kret, eErrorTypeMachKernel);
        return eConnectionStatusError;
    }

    return eConnectionStatusSuccess;
}

ConnectionStatus
ConnectionMachPort::Disconnect (Error *error_ptr)
{
    kern_return_t kret;
    
    // TODO: verify if we need to netname_check_out for
    // either or both 
    if (m_port != MACH_PORT_TYPE_NONE)
    {
        kret = ::mach_port_deallocate (m_task, m_port);       
        if (error_ptr)
            error_ptr->SetError (kret, eErrorTypeMachKernel);
        m_port = MACH_PORT_TYPE_NONE;
    }

    return eConnectionStatusSuccess;
}

size_t
ConnectionMachPort::Read (void *dst, 
                          size_t dst_len, 
                          uint32_t timeout_usec,
                          ConnectionStatus &status, 
                          Error *error_ptr)
{
    PayloadType payload;
    
    kern_return_t kret = Receive (payload);
    if (kret == KERN_SUCCESS)
    {
        memcpy (dst, payload.data, payload.data_length);
        status = eConnectionStatusSuccess;
        return payload.data_length;
    }
    
    if (error_ptr)
        error_ptr->SetError (kret, eErrorTypeMachKernel);
    status = eConnectionStatusError;
    return 0;
}

size_t
ConnectionMachPort::Write (const void *src, size_t src_len, ConnectionStatus &status, Error *error_ptr)
{
    PayloadType payload;
    payload.command = 0;
    payload.data_length = src_len;
    const size_t max_payload_size = sizeof(payload.data);
    if (src_len > max_payload_size)
        payload.data_length = max_payload_size;
    memcpy (payload.data, src, payload.data_length);
    
    if (Send (payload) == KERN_SUCCESS)
    {
        status = eConnectionStatusSuccess;
        return payload.data_length;
    }
    status = eConnectionStatusError;
    return 0;
}

ConnectionStatus
ConnectionMachPort::BytesAvailable (uint32_t timeout_usec, Error *error_ptr)
{
    return eConnectionStatusLostConnection;
}

kern_return_t 
ConnectionMachPort::Send (const PayloadType &payload)
{
	struct MessageType message;
    
	/* (i) Form the message : */
    
	/* (i.a) Fill the header fields : */
	message.head.msgh_bits = MACH_MSGH_BITS_REMOTE (MACH_MSG_TYPE_MAKE_SEND) | 
                             MACH_MSGH_BITS_OTHER (MACH_MSGH_BITS_COMPLEX);
	message.head.msgh_size = sizeof(MessageType);
	message.head.msgh_local_port = MACH_PORT_NULL;
	message.head.msgh_remote_port = m_port;
    
	/* (i.b) Explain the message type ( an integer ) */
    //	message.type.msgt_name = MACH_MSG_TYPE_INTEGER_32;
    //	message.type.msgt_size = 32;
    //	message.type.msgt_number = 1;
    //	message.type.msgt_inline = TRUE;
    //	message.type.msgt_longform = FALSE;
    //	message.type.msgt_deallocate = FALSE;
	/* message.type.msgt_unused = 0; */ /* not needed, I think */
    
	/* (i.c) Fill the message with the given integer : */
	message.payload = payload;
    
	/* (ii) Send the message : */
	kern_return_t kret = ::mach_msg (&message.head, 
                                     MACH_SEND_MSG, 
                                     message.head.msgh_size, 
                                     0, 
                                     MACH_PORT_NULL, 
                                     MACH_MSG_TIMEOUT_NONE, 
                                     MACH_PORT_NULL);
    
	return kret;
}

kern_return_t 
ConnectionMachPort::Receive (PayloadType &payload)
{
	MessageType message;
	message.head.msgh_size = sizeof(MessageType);
    
	kern_return_t kret = ::mach_msg (&message.head, 
                                     MACH_RCV_MSG, 
                                     0, 
                                     sizeof(MessageType), 
                                     m_port,
                                     MACH_MSG_TIMEOUT_NONE, 
                                     MACH_PORT_NULL);
    
    if (kret == KERN_SUCCESS)
        payload = message.payload;

	return kret;
}


#endif // #if defined(__APPLE__)