/********************************************************************************/
/*										*/
/*			    Windows 10 TPM Proxy	 			*/
/*			     Written by Ken Goldman				*/
/*		       IBM Thomas J. Watson Research Center			*/
/*										*/
/* (c) Copyright IBM Corporation 2006 - 2019.					*/
/*										*/
/* All rights reserved.								*/
/* 										*/
/* Redistribution and use in source and binary forms, with or without		*/
/* modification, are permitted provided that the following conditions are	*/
/* met:										*/
/* 										*/
/* Redistributions of source code must retain the above copyright notice,	*/
/* this list of conditions and the following disclaimer.			*/
/* 										*/
/* Redistributions in binary form must reproduce the above copyright		*/
/* notice, this list of conditions and the following disclaimer in the		*/
/* documentation and/or other materials provided with the distribution.		*/
/* 										*/
/* Neither the names of the IBM Corporation nor the names of its		*/
/* contributors may be used to endorse or promote products derived from		*/
/* this software without specific prior written permission.			*/
/* 										*/
/* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS		*/
/* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT		*/
/* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR	*/
/* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT		*/
/* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,	*/
/* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT		*/
/* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	*/
/* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	*/
/* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT		*/
/* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE	*/
/* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.		*/
/********************************************************************************/


/*
  Use this proxy when using the TSS command line utilities on Windows.  It keeps the connection to
  the Windows TPM device driver open.  This prevents its resource manager from flushing resources
  after each utiity exits.

  The server type (mssim or raw) should agree with the TSS configuration.  mssim wrapes the packets
  in the MS simulator bytes.  raw does not.

  For the mssim format, the server socket remains open until the TPM_SESSION_END preamble is
  received.  Then, the proxy loops back and reopens the connection for the next TSS client side
  open.

  The proxy is unnecessary when using a compiled application.

  Link with:

  tbs.lib
  ws2_32.lib
*/

#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <time.h>

#include <windows.h>
#include <specstrings.h>

#include <tbs.h>

#define LOAD32(buffer,offset)         ( ntohl(*(uint32_t *)&(buffer)[(offset)]) )

#ifndef SSIZE_MAX
#define SSIZE_MAX INT_MAX
#endif

/* standard TCG definitions */

typedef unsigned long 	TSS_RESULT;
typedef unsigned char 	BYTE;
typedef unsigned short 	TPM_TAG;

/* local constants */

#define ERROR_CODE	-1
#define DEFAULT_PORT 	2321
#define PACKET_SIZE	4096
#define TRACE_SIZE	(PACKET_SIZE * 4)

#define SERVER_TYPE_MSSIM	0
#define SERVER_TYPE_RAW		1
#define TPM_SEND_COMMAND        8	/* simulator command preamble */
#define TPM_SESSION_END        20

/* local prototypes */

void printUsage(void);
long getArgs(short *port,
	     int *verbose,
	     char **logFileName,
	     int argc,
	     char **argv);
void logAll(const char *message, unsigned long length, const unsigned char* buff);

TSS_RESULT socketInit(SOCKET *sock_fd, short port);
TSS_RESULT socketConnect(SOCKET *accept_fd,
			 SOCKET sock_fd,
			 short port);
TSS_RESULT socketRead(SOCKET accept_fd,
		      uint32_t	*commandType,
		      char *buffer,
		      uint32_t *bufferLength,
		      size_t bufferSize);
TSS_RESULT socketReadBytes(SOCKET accept_fd,
			   char *buffer,
			   size_t nbytes);
TSS_RESULT socketWrite(SOCKET accept_fd,
		       const char *buffer,
		       size_t buffer_length);
TSS_RESULT socketDisconnect(SOCKET accept_fd);

void TPM_HandleWsaStartupError(const char *prefix,
			       int irc);
void TPM_HandleWsaError(const char *prefix);
void TPM_GetWsaStartupError(int status,
			    const char **error_string);
void TPM_GetWsaError(const char **error_string);

void TPM_GetTBSError(const char *prefix,
		     TBS_RESULT rc);
void CheckTPMError(const char *prefix,
		     unsigned char *response);

/* global variable for trace logging */

int 	verbose;		/* verbose debug tracing */
char 	*logFilename;		/* trace log file name */
char	logMsg[TRACE_SIZE];	/* since it's big, put it here rather than on the stack */

/* global socket server format type */

int serverType = SERVER_TYPE_MSSIM;	/* default MS simulator format */

#define false 0
#define true 1

int main(int argc, char** argv)
{
    TBS_RESULT 		rc = 0;
    TBS_RESULT 		rc1 = 0;
    time_t 		start_time;
    int 		contextOpened = false;
    SOCKET 		sock_fd;		/* server socket */
    SOCKET 		accept_fd;    		/* server accept socket for a packet */
    int 		socketOpened = FALSE;

    TBS_HCONTEXT 	hContext = 0;
    TBS_CONTEXT_PARAMS2 contextParams;

    /* TPM command and response */
    BYTE command[PACKET_SIZE];
    uint32_t commandLength;
    BYTE response[PACKET_SIZE];
    uint32_t responseLength;

    /* command line arguments */
    short port;			/* TCPIP server port */

    /* command line argument defaults */
    port = DEFAULT_PORT;
    logFilename = NULL;
    verbose = FALSE;

    /* initialization */
    setvbuf(stdout, 0, _IONBF, 0);	/* output may be going through pipe */
    start_time = time(NULL);

    /* get command line arguments */
    if (rc == 0) {
	rc = getArgs(&port, &verbose, &logFilename,
		     argc, argv);
    }
    /* open HW TPM device driver */
    if (rc == 0) {
	if (verbose) printf("tpmproxy: start at %s", ctime(&start_time));
	if (verbose) printf("tpmproxy: server type %s\n",
			    (serverType == SERVER_TYPE_MSSIM) ? "MS simulator" : "raw");
	contextParams.version = TBS_CONTEXT_VERSION_TWO;
	contextParams.includeTpm12 = 0;
	contextParams.includeTpm20 = 1;
	rc = Tbsi_Context_Create((TBS_CONTEXT_PARAMS *)&contextParams,
				 &hContext);

	if (verbose) printf("tpmproxy: Tbsi_Context_Create rc %08x\n", rc);
	if (rc == 0) {
	    contextOpened = true;
	}
	else {
	    TPM_GetTBSError("Tbsi_Context_Create ", rc);
	}
    }
    /* open / initialize server socket */
    if (rc == 0) {
	if (verbose) printf("Opening socket at port %hu\n", port);
	rc = socketInit(&sock_fd, port);
	if (rc != 0) {
	    printf("tpmproxy: socket open failed\n");
	}
	else {
	    socketOpened = TRUE;
	}
    }
    /* outer loop, socket connect or reconnect */
    while (rc == 0) {

	uint32_t	commandType = TPM_SEND_COMMAND;	/* for first time through inner loop */
	/* connect to the client application */
	if (rc == 0) {
	    if (verbose) printf("Connecting on socket %hu\n", port);
	    rc = socketConnect(&accept_fd, sock_fd, port);
	}

	/* inner loop, read socket, send command, get response, write socket */
	while ((rc == 0) && (commandType == TPM_SEND_COMMAND)) {

	    /* read a command from client */
	    if ((rc == 0) && (commandType == TPM_SEND_COMMAND)) {
		rc = socketRead(accept_fd,
				&commandType,
				(char *)command,	/* windows wants signed */
				&commandLength,
				sizeof(command));
		logAll("Command", commandLength, command);
	    }
	    /* send command to TPM and receive response */
	    if ((rc == 0) && (commandType == TPM_SEND_COMMAND)) {
		responseLength = sizeof(response);
		rc = Tbsip_Submit_Command(hContext,
					  TBS_COMMAND_LOCALITY_ZERO,
					  TBS_COMMAND_PRIORITY_NORMAL,
					  command,
					  commandLength,
					  response,
					  &responseLength);
		if (rc != 0) {
		    TPM_GetTBSError("Tbsi_Context_Create ", rc);
		}
	    }
	    /* send response to client */
	    if ((rc == 0) && (commandType == TPM_SEND_COMMAND)) {
		logAll("Response", responseLength, response);
		rc = socketWrite(accept_fd,
				 (char *)response,	/* windows wants signed char */
				 responseLength);
	    }
	}
    }
    /* close socket */
    if (socketOpened) {
	socketDisconnect(sock_fd);
    }
    /* close TPM */
    if (contextOpened) {
	rc1 = Tbsip_Context_Close(hContext);
	if (verbose) printf("tpmproxy:Tbsip_Context_Close rc1 %08x\n", rc1);
	if (rc == 0) {
	    rc = rc1;
	}
    }
    if (verbose) printf("tpmproxy: exit rc %08x\n", rc);
    return rc;
}

/*
  All the socket code is basically a cut and paste from the TPM 1.2 tpm_io.c
*/

TSS_RESULT socketInit(SOCKET *sock_fd, short port)
{
    TSS_RESULT   	rc = 0;
    int			irc;
    struct sockaddr_in 	serv_addr;
    int 		opt;
    WSADATA 		wsaData;

    /* initiate use of the Windows Sockets DLL 2.0 */
    if (rc == 0) {
	if ((irc = WSAStartup(0x202,&wsaData)) != 0) {		/* if not successful */
	    printf("socketInit: Error, WSAStartup()\n");
	    TPM_HandleWsaStartupError("socketInit:", irc);
	    rc = ERROR_CODE;
	}
    }
    /* create a tcpip protocol socket */
    if (rc == 0) {
	/* if (verbose) printf(" socketInit: Port %hu\n", port); */
	*sock_fd = socket(AF_INET, SOCK_STREAM, 0);	/* tcpip socket */
	if (*sock_fd == INVALID_SOCKET) {
	    printf("socketInit: Error, server socket()\n");
	    TPM_HandleWsaError("socketInit:");
	    rc = ERROR_CODE;
	}
    }
    if (rc == 0) {
	memset(&serv_addr, 0, sizeof(serv_addr));
	serv_addr.sin_family = AF_INET;			/* Internet socket */
	serv_addr.sin_port = htons(port);		/* host to network byte order for short */
	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);	/* host to network byte order for long */
	opt = 1;
	/* Set SO_REUSEADDR before calling bind() for servers that bind to a fixed port number. */
	/* For boolean values, opt must be an int, but the setsockopt prototype is IMHO wrong.
	   It should take void *, but uses char *.  Hence the type cast. */
	irc = setsockopt(*sock_fd, SOL_SOCKET, SO_REUSEADDR, (char *)&opt, sizeof(opt));
	if (irc == SOCKET_ERROR) {
	    printf("socketInit: Error, server setsockopt()\n");
	    TPM_HandleWsaError("socketInit:");
	    closesocket(*sock_fd);
	    rc = ERROR_CODE;
	}
    }
    /* bind the (local) server port name to the socket */
    if (rc == 0) {
	irc = bind(*sock_fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr));
	if (irc == SOCKET_ERROR) {
	    printf("socketInit: Error, server bind()\n");
	    printf("socketInit: Is SW TPM listening on this port?\n");
	    TPM_HandleWsaError("socketInit:");
	    closesocket(*sock_fd);
	    rc = ERROR_CODE;
	}
    }
    /* listen for a connection to the socket */
    if (rc == 0) {
	irc = listen(*sock_fd, SOMAXCONN);
	if (irc == SOCKET_ERROR) {
	    printf("socketInit: Error, server listen()\n");
	    TPM_HandleWsaError("socketInit:");
	    closesocket(*sock_fd);
	    rc = ERROR_CODE;
	}
    }
    if (rc != 0) {
	WSACleanup();
    }
    return rc;
}

TSS_RESULT socketConnect(SOCKET *accept_fd,
			 SOCKET sock_fd,
			 short port)
{
    TSS_RESULT		rc = 0;
    int			cli_len;
    struct sockaddr_in 	cli_addr;		/* Internet version of sockaddr */

    /* accept a connection */
    if (rc == 0) {
	cli_len = sizeof(cli_addr);
	/* block until connection from client */
	/* printf(" socketConnect: Waiting for connection on port %hu ...\n", port); */
	*accept_fd = accept(sock_fd, (struct sockaddr *)&cli_addr, &cli_len);
	if (*accept_fd == SOCKET_ERROR) {
	    printf("socketConnect: Error, accept()\n");
	    TPM_HandleWsaError("socketConnect: ");
	    closesocket(sock_fd);
	    WSACleanup();
	    rc = ERROR_CODE;
	}
    }
    return rc;
}

/* socketRead() reads a TPM command packet from the host

   Puts the result in 'buffer' up to 'bufferSize' bytes.

   On success, if commandType is TPM_SEND_COMMAND, the number of bytes in the buffer is equal to
   'bufferLength' bytes.  If commandType is TPM_SESSION_END, return it.  The loop should restart.

   This function is intended to be platform independent.
*/

TSS_RESULT socketRead(SOCKET 	accept_fd,		/* read/write file descriptor */
		      uint32_t	*commandType,
		      char 	*buffer,		/* output: command stream */
		      uint32_t 	*bufferLength,	/* output: command stream length */
		      size_t 	bufferSize)	/* input: max size of output buffer */
{
    TSS_RESULT		rc = 0;
    int			done = false;
    uint32_t		headerSize;	/* minimum required bytes in command through paramSize */
    uint32_t		paramSize;	/* from command stream */
    uint32_t		commandTypeNbo;	/* MS simulator format preamble */
    uint8_t 		locality;	/* MS simulator format preamble */
    uint32_t 		lengthNbo;	/* MS simulator format preamble */

    /* if the MS simulator packet format */
    if (serverType == SERVER_TYPE_MSSIM) {
	/* read and check the command */
	if (rc == 0) {
	    rc = socketReadBytes(accept_fd, (char *)&commandTypeNbo, sizeof(uint32_t));
	}
	if (rc == 0) {
	    *commandType = LOAD32(&commandTypeNbo, 0);
	    if (*commandType == TPM_SESSION_END) {	/* client TSS termination request */
		done = true;
	    }
	    else if (*commandType != TPM_SEND_COMMAND) {
		printf("socketRead: Error, -mssim preamble is %08x not %08x\n",
		       *commandType, TPM_SEND_COMMAND);
		rc = ERROR_CODE;
	    }
	}
	/* read and discard the locality */
	if ((rc == 0) && !done) {
	    rc = socketReadBytes(accept_fd, &locality, sizeof(uint8_t));
	}
	/* read and discard the redundant length */
	if ((rc == 0) && !done) {
	    rc = socketReadBytes(accept_fd, (char *)&lengthNbo, sizeof(uint32_t));
	}
    }
    /* check that the buffer can at least fit the command through the paramSize */
    if ((rc == 0) && !done) {
	headerSize = sizeof(TPM_TAG) + sizeof(uint32_t);
	if (bufferSize < headerSize) {
	    printf("socketRead: Error, buffer size %lu less than minimum %lu\n",
		   (unsigned long)bufferSize, (unsigned long)headerSize);
	    rc = ERROR_CODE;
	}
    }
    /* read the command through the paramSize from the socket stream */
    if ((rc == 0) && !done) {
	rc = socketReadBytes(accept_fd, buffer, headerSize);
    }
    if ((rc == 0) && !done) {
	/* extract the paramSize value, last field in header */
	paramSize = LOAD32(buffer, headerSize - sizeof(uint32_t));
	*bufferLength = headerSize + paramSize - (sizeof(TPM_TAG) + sizeof(uint32_t));
	if (bufferSize < *bufferLength) {
	    printf("socketRead: Error, buffer size %lu is less than required %u\n",
		   (unsigned long)bufferSize, *bufferLength);
	    rc = ERROR_CODE;
	}
    }
    /* read the rest of the command (already read tag and paramSize) */
    if ((rc == 0) && !done) {
	rc = socketReadBytes(accept_fd,
			     buffer + headerSize,
			     paramSize - (sizeof(TPM_TAG) + sizeof(uint32_t)));
    }
    return rc;
}

/* socketReadBytes() reads nbytes from accept_fd and puts them in buffer.

   The buffer has already been checked for sufficient size.
*/

TSS_RESULT socketReadBytes(SOCKET accept_fd,	/* read/write file descriptor */
			   char *buffer,
			   size_t nbytes)
{
    TSS_RESULT rc = 0;
    int nread = 0;
    size_t nleft = nbytes;

    /* read() is unspecified with nbytes too large */
    if (rc == 0) {
	if (nleft > SSIZE_MAX) {
	    rc = ERROR_CODE;
	}
    }
    while ((rc == 0) && (nleft > 0)) {
	nread = recv(accept_fd, buffer, (int)nleft, 0);
	if ((nread == SOCKET_ERROR) ||
	    (nread < 0)) {       		/* error */
	    printf("socketReadBytes: Error, read() error\n");
	    TPM_HandleWsaError("socketReadBytes:");
	    socketDisconnect(accept_fd);
            rc = ERROR_CODE;
	}
	else if (nread > 0) {
	    nleft -= nread;
	    buffer += nread;
	}
	else if (nread == 0) {  	/* EOF */
	    printf("socketReadBytes: Error, read EOF, read %lu bytes\n", (unsigned long)(nbytes - nleft));
            rc = ERROR_CODE;
	}
    }
    return rc;
}

/* socketWrite() writes buffer_length bytes from buffer to accept_fd.

   In mmssim mode, it prepends the size and appends the acknowledgement.
 */

TSS_RESULT socketWrite(SOCKET accept_fd,	/* read/write file descriptor */
		       const char *buffer,
		       size_t buffer_length)
{
    TSS_RESULT 	rc = 0;
    int		nwritten = 0;

    /* write() is unspecified with buffer_length too large */
    if (rc == 0) {
	if (buffer_length > SSIZE_MAX) {
	    rc = ERROR_CODE;
	}
    }
    /* if the MS simulator packet format */
    if (serverType == SERVER_TYPE_MSSIM) {
	/* prepend the leading size */
	if (rc == 0) {
	    uint32_t bufferLengthNbo = htonl((uint32_t)buffer_length);
	    send(accept_fd, (const char *)&bufferLengthNbo, sizeof(uint32_t), 0);
	}
    }
   /* test that connection is open to write */
    if (rc == 0) {
	if (accept_fd == SOCKET_ERROR) {
	    printf("socketWrite: Error, connection not open, fd %d\n",
		   (int)accept_fd);
	    rc = ERROR_CODE;
	}
    }
    while ((rc == 0) && (buffer_length > 0)) {
	nwritten = send(accept_fd, buffer, (int)buffer_length, 0);
	if ((nwritten == SOCKET_ERROR) ||
	    (nwritten < 0)) {
	    printf("socketWrite: Error, send()\n");
	    TPM_HandleWsaError("socketWrite:");	/* report the error */
	    socketDisconnect(accept_fd);
	    rc = ERROR_CODE;
	}
	else {
	    buffer_length -= nwritten;
	    buffer += nwritten;
	}
    }
    /* if the MS simulator packet format */
    if (serverType == SERVER_TYPE_MSSIM) {
	/* append the trailing acknowledgement */
	if (rc == 0) {
	    uint32_t acknowledgement = 0;
	    send(accept_fd, (const char *)&acknowledgement, sizeof(uint32_t), 0);
	}
    }
    return rc;
}

/* socketDisconnect() breaks the connection between the TPM server and the host client

   This is the Windows platform dependent socket version.
*/

TSS_RESULT socketDisconnect(SOCKET accept_fd)
{
    TSS_RESULT 	rc = 0;
    int		irc;

    /* close the connection to the client */
    if (verbose) printf("Closing socket\n");
    if (rc == 0) {
	irc = closesocket(accept_fd);
	accept_fd = SOCKET_ERROR;	/* mark the connection closed */
	if (irc == SOCKET_ERROR) {
	    printf("socketDisconnect: Error, closesocket()\n");
	    rc = ERROR_CODE;
	}
    }
    return rc;
}

void TPM_HandleWsaStartupError(const char *prefix,
			       int irc)
{
    const char *error_string;

    TPM_GetWsaStartupError(irc, &error_string);
    printf("%s %s\n", prefix, error_string);
    return;
}

void TPM_HandleWsaError(const char *prefix)
{
    const char *error_string;

    TPM_GetWsaError(&error_string);
    printf("%s %s\n", prefix, error_string);
    return;
}

void TPM_GetWsaStartupError(int status,
			    const char **error_string)
{
    /* convert WSAStartup status to more useful text.  Copy the text to error_string */

    switch(status) {
      case WSASYSNOTREADY:
	*error_string = "WSAStartup error: WSASYSNOTREADY underlying network subsystem not ready for "
			"network communication";
	break;
      case WSAVERNOTSUPPORTED:
	*error_string = "WSAStartup error: WSAVERNOTSUPPORTED version requested not provided by WinSock "
			"implementation";
	break;
      case WSAEINPROGRESS:
	*error_string = "WSAStartup error: WSAEINPROGRESS blocking WinSock 1.1 operation in progress";
	break;
      case WSAEPROCLIM:
	*error_string = "WSAStartup error: WSAEPROCLIM Limit on number of tasks supported by WinSock "
			"implementation has been reached";
	break;
      case WSAEFAULT:
	*error_string = "WSAStartup error: WSAEFAULT lpWSAData is not a valid pointer";
	break;
      default:
	*error_string = "WSAStartup error: return code unknown";
	break;
    }
    return;
}

void TPM_GetWsaError(const char **error_string)
{
    /* Use WSAGetLastError, and convert the resulting number
       to more useful text.  Copy the text to error_string */

    int error;

    error = WSAGetLastError();
    switch(error) {

      case WSANOTINITIALISED :
	*error_string = "A successful WSAStartup must occur before using this function";
	break;
      case WSAENETDOWN :
	*error_string = "The network subsystem or the associated service provider has failed";
	break;
      case WSAEAFNOSUPPORT :
	*error_string = "The specified address family is not supported";
	break;
      case WSAEINPROGRESS :
	*error_string = "A blocking Windows Sockets 1.1 call is in progress, "
			"or the service provider is still processing a callback function";
	break;
      case WSAEMFILE:
	*error_string = "No more socket descriptors are available";
	break;
      case WSAENOBUFS:
	*error_string = "No buffer space is available";
	break;
      case WSAEPROTONOSUPPORT:
	*error_string = "The specified protocol is not supported";
	break;
      case WSAEPROTOTYPE:
	*error_string = "The specified protocol is the wrong type for this socket";
	break;
      case WSAESOCKTNOSUPPORT :
	*error_string = "The specified socket type is not supported in this address family";
	break;
      case WSAEFAULT:
	*error_string = "A parameter is too small, bad format, or bad value";
	break;
      case WSAEINVAL:
	*error_string = "The socket has not been bound with bind, or listen not called";
	break;
      case WSAENETRESET:
	*error_string = "The connection has been broken due to the remote host resetting";
	break;
      case WSAENOPROTOOPT:
	*error_string = "The option is unknown or unsupported for the specified provider";
	break;
      case WSAENOTCONN:
	*error_string = "Connection has been reset when SO_KEEPALIVE is set";
	break;
      case WSAENOTSOCK:
	*error_string = "The descriptor is not a socket";
	break;
      case WSAEADDRINUSE:
	*error_string = "The specified address is already in use";
	break;
      case WSAEISCONN:
	*error_string = "The socket is already connected";
	break;
      case WSAEOPNOTSUPP:
	*error_string = "The referenced socket is not of a type that supports the operation";
	break;
      case WSAEINTR:
	*error_string = "The (blocking) call was canceled through WSACancelBlockingCall";
      case WSAEWOULDBLOCK:
	*error_string = "The socket is marked as nonblocking and no connections are present to be accepted";
	break;
      case WSAESHUTDOWN:
	*error_string = "The socket has been shut down; it is not possible to recv or send on a socket "
			"after shutdown has been invoked with how set to SD_RECEIVE or SD_BOTH";
	break;
      case WSAEMSGSIZE:
	*error_string = "The message was too large to fit into the specified buffer and was truncated";
	break;
      case WSAECONNABORTED:
	*error_string = "The virtual circuit was terminated due to a time-out or other failure. "
			"The application should close the socket as it is no longer usable";
	break;
      case WSAETIMEDOUT:
	*error_string = "The connection has been dropped because of a network failure or because "
			"the peer system failed to respond";
	break;
      case WSAECONNRESET:
	*error_string = "The virtual circuit was reset by the remote side executing a hard or abortive close. "
			"The application should close the socket as it is no longer usable. On a UDP datagram "
			"socket this error would indicate that a previous send operation resulted in an ICMP "
			"Port Unreachable message";
	break;
      case WSAEACCES:
	*error_string = "The requested address is a broadcast address, but the appropriate flag was not set";
	break;
      case WSAEHOSTUNREACH:
	*error_string = "The remote host cannot be reached from this host at this time";
	break;

      default:
	*error_string = "unknown error type\n";
	break;
    }
    return;
}

void TPM_GetTBSError(const char *prefix,
		     TBS_RESULT rc)
{
    const char *error_string;

    switch (rc) {

	/* error codes from the TBS html docs */
      case TBS_SUCCESS:
	error_string = "The function succeeded.";
	break;
      case TBS_E_INTERNAL_ERROR:
	error_string = "An internal software error occurred.";
	break;
      case TBS_E_BAD_PARAMETER:
	error_string = "One or more parameter values are not valid.";
	break;
      case TBS_E_INVALID_OUTPUT_POINTER:
	error_string = "A specified output pointer is bad.";
	break;
      case TBS_E_INVALID_CONTEXT:
	error_string = "The specified context handle does not refer to a valid context.";
	break;
      case TBS_E_INSUFFICIENT_BUFFER:
	error_string = "The specified output buffer is too small.";
	break;
      case TBS_E_IOERROR:
	error_string = "An error occurred while communicating with the TPM.";
	break;
      case TBS_E_INVALID_CONTEXT_PARAM:
	error_string = "A context parameter that is not valid was passed when attempting to create a "
			"TBS context.";
	break;
      case TBS_E_SERVICE_NOT_RUNNING:
	error_string = "The TBS service is not running and could not be started.";
	break;
      case TBS_E_TOO_MANY_TBS_CONTEXTS:
	error_string = "A new context could not be created because there are too many open contexts.";
	break;
      case TBS_E_TOO_MANY_RESOURCES:
	error_string = "A new virtual resource could not be created because there are too many open "
			"virtual resources.";
	break;
      case TBS_E_SERVICE_START_PENDING:
	error_string = "The TBS service has been started but is not yet running.";
	break;
      case TBS_E_PPI_NOT_SUPPORTED:
	error_string = "The physical presence interface is not supported.";
	break;
      case TBS_E_COMMAND_CANCELED:
	error_string = "The command was canceled.";
	break;
      case TBS_E_BUFFER_TOO_LARGE:
	error_string = "The input or output buffer is too large.";
	break;
      case TBS_E_TPM_NOT_FOUND:
	error_string = "A compatible Trusted Platform Module (TPM) Security Device cannot be found "
			"on this computer.";
	break;
      case TBS_E_SERVICE_DISABLED:
	error_string = "The TBS service has been disabled.";
	break;
      case TBS_E_NO_EVENT_LOG:
	error_string = "The TBS event log is not available.";
	break;
      case TBS_E_ACCESS_DENIED:
	error_string = "The caller does not have the appropriate rights to perform the requested operation.";
	break;
      case TBS_E_PROVISIONING_NOT_ALLOWED:
	error_string = "The TPM provisioning action is not allowed by the specified flags.";
	break;
      case TBS_E_PPI_FUNCTION_UNSUPPORTED:
	error_string = "The Physical Presence Interface of this firmware does not support the "
			"requested method.";
	break;
      case TBS_E_OWNERAUTH_NOT_FOUND:
	error_string = "The requested TPM OwnerAuth value was not found.";
	break;

	/* a few error codes from WinError.h */
      case TPM_E_COMMAND_BLOCKED:
	error_string = "The command was blocked.";
	break;

      default:
	error_string = "unknown error type\n";
	break;

    }
    printf("%s %s\n", prefix, error_string);
    return;
}

void CheckTPMError(const char *prefix,
		   unsigned char *response)
{
    const char *error_string;
    uint32_t tpmError = htonl(*(uint32_t *)(response+6));

    if (tpmError != 0) {

	switch (tpmError) {
	    /* a few error codes from WinError.h */
	  case TPM_E_COMMAND_BLOCKED:
	    error_string = "The command was blocked.";
	    break;
	  default:
	    error_string = "unknown error type\n";
	    printf("TPM error %08x\n", tpmError);
	    break;
	}
	printf("%s %s\n", prefix, error_string);
    }
    return;
}

/* logging, tracing */

void logAll(const char *message, unsigned long length, const unsigned char* buff)
{
    unsigned long i;
    size_t 	nextChar = 0;
    FILE 	*logFile;	/* trace log file descriptor */

    /* construct the log message, keep appending to the character string */
    if (buff != NULL) {
	nextChar += sprintf(logMsg + nextChar, "%s length %lu\n ", message, length);
	for (i = 0 ; i < length ; i++) {
	    if (i && !( i % 16 )) {
		nextChar += sprintf(logMsg + nextChar, "\n ");
	    }
	    nextChar += sprintf(logMsg + nextChar, "%.2X ",buff[i]);
	}
	nextChar += sprintf(logMsg + nextChar, "\n");
    }
    else {
	nextChar += sprintf(logMsg + nextChar, "%s null\n", message);
    }
    if (verbose) printf("%s", logMsg);
    if (logFilename != NULL) {
	/* Open the log file if specified.  It's a hack to keep opening and closing the file for
	   each append, but it's easier that trying to catch a signal to close the file.  Windows
	   evidently doesn't automatically close the file when the program exits. */
	logFile = fopen(logFilename, "a");
	if (logFile == NULL) {
	    printf("Error, opening %s for write failed, %s\n",
		   logFilename, strerror(errno));
	}
	/* if success, print and close */
	else {
	    fprintf(logFile, "%s", logMsg);
	    fclose(logFile);
	}
    }
    return;
}

/* parse the command line arguments */

long getArgs(short *port,
	     int *verbose,
	     char **logFilename,
	     int argc,
	     char **argv)
{
    long 	rc = 0;
    int		irc;
    int 	i;
    FILE 	*logFile;	/* trace log file descriptor */

    /* get the command line arguments */
    for (i=1 ; (i<argc) && (rc == 0) ; i++) {
	if ((strcmp(argv[i],"-p") == 0) ||
	    (strcmp(argv[i],"--port") == 0)) {
	    i++;
	    if (i < argc) {
		irc = sscanf(argv[i], "%hu", port);
		if (irc != 1) {
		    printf("-p --port (socket port) illegal value %s\n", argv[i]);
		    rc = ERROR_CODE;
		}
	    } else {
		printf("-p --port (socket port) needs a value\n");
		rc = ERROR_CODE;
	    }
	}
	else if (strcmp(argv[i],"-raw") == 0) {
	    serverType = SERVER_TYPE_RAW;
	}
	else if (strcmp(argv[i],"-mssim") == 0) {
	    serverType = SERVER_TYPE_MSSIM;
	}
	else if (strcmp(argv[i],"-h") == 0) {
	    printUsage();
	    rc = ERROR_CODE;
	}
	else if ((strcmp(argv[i],"-v") == 0) ||
		 (strcmp(argv[i],"--verbose") == 0)) {
	    *verbose = TRUE;
	}
	else if ((strcmp(argv[i],"-l") == 0) ||
		 (strcmp(argv[i],"--log") == 0)) {
	    i++;
	    if (i < argc) {
		if (strlen(argv[i]) < FILENAME_MAX) {
		    *logFilename = argv[i];
		}
		else {
		    printf("-l --log (log file name) too long\n");
		    rc = ERROR_CODE;
		}
	    }
	    else {
		printf("-l --log option (log file name) needs a value\n");
		rc = ERROR_CODE;
	    }
	}
	else {
	    printf("\n%s is not a valid option\n",argv[i]);
	    printUsage();
	    rc = ERROR_CODE;
	}
    }
    /* erase old contents of log file */
    if ((rc == 0) && (*logFilename != NULL)) {
	logFile = fopen(*logFilename, "w");
	if (logFile == NULL) {
	    printf("Cannot open log file %s\n", *logFilename);
	    rc = ERROR_CODE;
	}
	else {
	    fclose(logFile);
	}
    }
    return rc;
}

void printUsage()
{
    printf("\n");
    printf("tpmproxy\n");
    printf("\n");
    printf("Pass through connecting a TCPIP port to a hardware TPM\n");
    printf("\n");
    printf("\t--port,-p <n> TCPIP server port (default 2321)\n");
    printf("\t-mssim use MS TPM 2.0 socket simulator packet format (default)\n");
    printf("\t\twith TSS env variable TPM_SERVER_TYPE=mssim (default)\n");
    printf("\t-raw use TPM 2.0 packet format\n");
    printf("\t\twith TSS env variable TPM_SERVER_TYPE=raw\n");
    printf("\t--verbose,-v verbose mode (default false)\n");
    printf("\t--log,-l log transactions into given file (default none)\n");
    printf("\t \n");
    return;
}
