/*  communicate.c -- ARMulator RDP comms code:  ARM6 Instruction Emulator.
    Copyright (C) 1994 Advanced RISC Machines Ltd.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that 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, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */

/**************************************************************************/
/* Functions to read and write characters or groups of characters         */
/* down sockets or pipes.  Those that return a value return -1 on failure */
/* and 0 on success.                                                      */
/**************************************************************************/

#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#include "armdefs.h"

/* The socket to the debugger */
int debugsock;

/* The maximum number of file descriptors */
extern int nfds;

/* The socket handle */
extern int sockethandle;

/* Read and Write routines down a pipe or socket */

/****************************************************************/
/* Read an individual character.                                */
/* All other read functions rely on this one.                   */
/* It waits 15 seconds until there is a character available: if */
/* no character is available, then it timeouts and returns -1.  */
/****************************************************************/
int MYread_char(int sock, unsigned char *c) {
  int i;
  fd_set readfds;
  struct timeval timeout= {15, 0};
  struct sockaddr_in isa;

 retry:

  FD_ZERO(&readfds);
  FD_SET(sock, &readfds);
  
  i = select(nfds, &readfds,
	     (fd_set *) 0,
	     (fd_set *) 0,
	     &timeout);

  if (i < 0) {
    perror("select");
    exit(1);
  }
  
  if (!i) {
    fprintf(stderr, "read: Timeout\n");
    return -1;
  }
  
  if ((i = read(sock, c, 1)) < 1) {
    if (!i && sock == debugsock) {
      fprintf(stderr, "Connection with debugger severed.\n");
      /* This shouldn't be necessary for a detached armulator, but
	 the armulator cannot be cold started a second time, so
	 this is probably preferable to locking up.  */
      return -1;
      fprintf(stderr, "Waiting for connection from debugger...");
      debugsock = accept(sockethandle, &isa, &i);
      if (debugsock < 0) { /* Now we are in serious trouble... */
	perror("accept");
	return -1;
      }
      fprintf(stderr, " done.\nConnection Established.\n");
      sock = debugsock;
      goto retry;
    }
    perror("read");
    return -1;
  }
  
#ifdef DEBUG
  if (sock == debugsock) fprintf(stderr, "<%02x ", *c);
#endif
  
  return 0;
}

/****************************************************************/
/* Read an individual character.                                */
/* It waits until there is a character available. Returns -1 if */
/* an error occurs.                                             */
/****************************************************************/
int MYread_charwait(int sock, unsigned char *c) {
  int i;
  fd_set readfds;
  struct sockaddr_in isa;

 retry:
  
  FD_ZERO(&readfds);
  FD_SET(sock, &readfds);
  
  i = select(nfds, &readfds,
	     (fd_set *) 0,
	     (fd_set *) 0,
	     (struct timeval *) 0);

  if (i < 0) {
    perror("select");
    exit(-1);
  }
  
  if ((i = read(sock, c, 1)) < 1) {
    if (!i && sock == debugsock) {
      fprintf(stderr, "Connection with debugger severed.\n");
      return -1;
      fprintf(stderr, "Waiting for connection from debugger...");
      debugsock = accept(sockethandle, &isa, &i);
      if (debugsock < 0) { /* Now we are in serious trouble... */
	perror("accept");
	return -1;
      }
      fprintf(stderr, " done.\nConnection Established.\n");
      sock = debugsock;
      goto retry;
    }
    perror("read");
    return -1;
  }
  
#ifdef DEBUG
  if (sock == debugsock) fprintf(stderr, "<%02x ", *c);
#endif
  
  return 0;
}

void MYwrite_char(int sock, unsigned char c) {

  if (write(sock, &c, 1) < 1)
    perror("write");
#ifdef DEBUG
  if (sock == debugsock) fprintf(stderr, ">%02x ", c);  
#endif
}

int MYread_word(int sock, ARMword *here) {
  unsigned char a, b, c, d;
  
  if (MYread_char(sock, &a) < 0) return -1;
  if (MYread_char(sock, &b) < 0) return -1;
  if (MYread_char(sock, &c) < 0) return -1;
  if (MYread_char(sock, &d) < 0) return -1;
  *here = a | b << 8 | c << 16 | d << 24;
  return 0;
}

void MYwrite_word(int sock, ARMword i) {
  MYwrite_char(sock, i & 0xff);
  MYwrite_char(sock, (i & 0xff00) >> 8);
  MYwrite_char(sock, (i & 0xff0000) >> 16);
  MYwrite_char(sock, (i & 0xff000000) >> 24);
}

void MYwrite_string(int sock, char *s) {
  int i;  
  for (i = 0; MYwrite_char(sock, s[i]), s[i]; i++);
}

int MYread_FPword(int sock, char *putinhere) {
  int i;
  for (i = 0; i < 16; i++)
    if (MYread_char(sock, &putinhere[i]) < 0) return -1;
  return 0;
}

void MYwrite_FPword(int sock, char *fromhere) {
  int i;
  for (i = 0; i < 16; i++)
    MYwrite_char(sock, fromhere[i]);
}

/* Takes n bytes from source and those n bytes */
/* down to dest */
int passon(int source, int dest, int n) {
  char *p;
  int i;
  
  p = (char *) malloc(n);
  if (!p) {
    perror("Out of memory\n");
    exit(1);
  }
  if (n) {
    for (i = 0; i < n; i++)
      if (MYread_char(source, &p[i]) < 0) return -1;
    
#ifdef DEBUG
    if (dest == debugsock) 
      for (i = 0; i < n; i++) fprintf(stderr, ")%02x ", (unsigned char) p[i]);
#endif
    
    write(dest, p, n);
  }
  free(p);
  return 0;
}
