/* UNIX RFCNB (RFC1001/RFC1002) NetBIOS implementation

   Version 1.0
   RFCNB Utility Routines ...

   Copyright (C) Richard Sharpe 1996

*/

/*
   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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <string.h>
#include <malloc.h>
#include <arpa/inet.h>

#include "std-includes.h"
#include "rfcnb-priv.h"
#include "rfcnb-util.h"
#include "rfcnb-io.h"

extern void (*Prot_Print_Routine)(FILE *, int, struct RFCNB_Pkt *, int, int); /* Pointer to protocol print routine */

/* Convert name and pad to 16 chars as needed */
/* Name 1 is a C string with null termination, name 2 may not be */
/* If SysName is true, then put a <00> on end, else space>       */

void RFCNB_CvtPad_Name(char *name1, char *name2)

{ char c, c1, c2;
  int i, len;

  len = strlen(name1);

  for (i = 0; i < 16; i++) {

    if (i >= len) {

     c1 = 'C'; c2 = 'A'; /* CA is a space */
 
    } else {

      c = name1[i];
      c1 = (char)((int)c/16 + (int)'A');
      c2 = (char)((int)c%16 + (int)'A');
    }

    name2[i*2] = c1;
    name2[i*2+1] = c2;

  }

  name2[32] = 0;   /* Put in the nll ...*/

}

/* Converts an Ascii NB Name (16 chars) to an RFCNB Name (32 chars)
   Uses the encoding in RFC1001. Each nibble of byte is added to 'A'
   to produce the next byte in the name.

   This routine assumes that AName is 16 bytes long and that NBName has 
   space for 32 chars, so be careful ... 

*/

void RFCNB_AName_To_NBName(char *AName, char *NBName)

{ char c, c1, c2;
  int i;

  for (i=0; i < 16; i++) {

    c = AName[i];

    c1 = (char)((c >> 4) + 'A');
    c2 = (char)((c & 0xF) + 'A');

    NBName[i*2] = c1;
    NBName[i*2+1] = c2;
  }

  NBName[32] = 0; /* Put in a null */

}

/* Do the reverse of the above ... */

void RFCNB_NBName_To_AName(char *NBName, char *AName)

{ char c, c1, c2;
  int i;

  for (i=0; i < 16; i++) {

    c1 = NBName[i*2];
    c2 = NBName[i*2+1];

    c = (char)(((int)c1 - (int)'A') * 16 + ((int)c2 - (int)'A'));

    AName[i] = c;

  }

  AName[i] = 0;   /* Put a null on the end ... */

}

/* Print a string of bytes in HEX etc */

void RFCNB_Print_Hex(FILE *fd, struct RFCNB_Pkt *pkt, int Offset, int Len)

{ char c1, c2, outbuf1[33];
  unsigned char c;
  int i, j;
  struct RFCNB_Pkt *pkt_ptr = pkt;
  static char Hex_List[17] = "0123456789ABCDEF";

  j = 0;

  /* We only want to print as much as sepcified in Len */

  while (pkt_ptr != NULL) {

    for (i = 0; 
	 i < ((Len > (pkt_ptr -> len)?pkt_ptr -> len:Len) - Offset); 
	 i++) {

      c = pkt_ptr -> data[i + Offset];
      c1 = Hex_List[c >> 4];
      c2 = Hex_List[c & 0xF];

      outbuf1[j++] = c1; outbuf1[j++] = c2;

      if (j == 32){ /* Print and reset */
	outbuf1[j] = 0;
	fprintf(fd, "    %s\n", outbuf1);
	j = 0;
      }

    }

    Offset = 0;
    Len = Len - pkt_ptr -> len;   /* Reduce amount by this much */
    pkt_ptr = pkt_ptr -> next;

  }

  /* Print last lot in the buffer ... */

  if (j > 0) {

    outbuf1[j] = 0;
    fprintf(fd, "    %s\n", outbuf1);

  }

  fprintf(fd, "\n");

}

/* Get a packet of size n */

struct RFCNB_Pkt *RFCNB_Alloc_Pkt(int n)

{ RFCNB_Pkt *pkt;

  if ((pkt = (struct RFCNB_Pkt *)malloc(sizeof(struct RFCNB_Pkt))) == NULL) {

    RFCNB_errno = RFCNBE_NoSpace;
    RFCNB_saved_errno = errno;
    return(NULL);

  }

  pkt -> next = NULL;
  pkt -> len = n;

  if (n == 0) return(pkt);

  if ((pkt -> data = (char *)malloc(n)) == NULL) {

    RFCNB_errno = RFCNBE_NoSpace;
    RFCNB_saved_errno = errno;
    free(pkt);
    return(NULL);

  }

  return(pkt);

}

/* Free up a packet */

int RFCNB_Free_Pkt(struct RFCNB_Pkt *pkt)

{ struct RFCNB_Pkt *pkt_next; char *data_ptr;

  while (pkt != NULL) {

    pkt_next = pkt -> next;

    data_ptr = pkt -> data;

    if (data_ptr != NULL)
      free(data_ptr);

    free(pkt);

    pkt = pkt_next;

  }
  return 0;
}

/* Print an RFCNB packet */

void RFCNB_Print_Pkt(FILE *fd, char *dirn, struct RFCNB_Pkt *pkt, int len)

{ char lname[17];

  /* We assume that the first fragment is the RFCNB Header  */
  /* We should loop through the fragments printing them out */

  fprintf(fd, "RFCNB Pkt %s:", dirn);

  switch (RFCNB_Pkt_Type(pkt -> data)) {

  case RFCNB_SESSION_MESSAGE: 

    fprintf(fd, "SESSION MESSAGE: Length = %i\n", RFCNB_Pkt_Len(pkt -> data));
    RFCNB_Print_Hex(fd, pkt, RFCNB_Pkt_Hdr_Len, 
#ifdef RFCNB_PRINT_DATA
		    RFCNB_Pkt_Len(pkt -> data) - RFCNB_Pkt_Hdr_Len);
#else
                    40);
#endif

  if (Prot_Print_Routine != 0) { /* Print the rest of the packet */
	
    Prot_Print_Routine(fd, strcmp(dirn, "sent"), pkt, RFCNB_Pkt_Hdr_Len,
		       RFCNB_Pkt_Len(pkt -> data) - RFCNB_Pkt_Hdr_Len);

      }

      break;

 case RFCNB_SESSION_REQUEST:

      fprintf(fd, "SESSION REQUEST: Length = %i\n",
		  RFCNB_Pkt_Len(pkt -> data));
      RFCNB_NBName_To_AName((char *)(pkt -> data + RFCNB_Pkt_Called_Offset), lname);
      fprintf(fd, "  Called Name: %s\n", lname);
      RFCNB_NBName_To_AName((char *)(pkt -> data + RFCNB_Pkt_Calling_Offset), lname);
      fprintf(fd, "  Calling Name: %s\n", lname);

      break;

 case RFCNB_SESSION_ACK:

      fprintf(fd, "RFCNB SESSION ACK: Length = %i\n",
		  RFCNB_Pkt_Len(pkt -> data));

      break;

 case RFCNB_SESSION_REJ:
      fprintf(fd, "RFCNB SESSION REJECT: Length = %i\n", 
		  RFCNB_Pkt_Len(pkt -> data));

      if (RFCNB_Pkt_Len(pkt -> data) < 1) {
	fprintf(fd, "   Protocol Error, short Reject packet!\n");
      }
      else {
	fprintf(fd, "   Error = %x\n", CVAL(pkt -> data, RFCNB_Pkt_Error_Offset));
      }

      break;

 case RFCNB_SESSION_RETARGET:

      fprintf(fd, "RFCNB SESSION RETARGET: Length = %i\n",
		  RFCNB_Pkt_Len(pkt -> data));

      /* Print out the IP address etc and the port? */

      break;

 case RFCNB_SESSION_KEEP_ALIVE:

      fprintf(fd, "RFCNB SESSION KEEP ALIVE: Length = %i\n",
	      RFCNB_Pkt_Len(pkt -> data));
      break;

    default:

      break;
  }

}

/* Resolve a name into an address */

int RFCNB_Name_To_IP(char *host, struct in_addr *Dest_IP)

{ int addr;         /* Assumes IP4, 32 bit network addresses */
  struct hostent *hp;

        /* Use inet_addr to try to convert the address */

  if ((addr = inet_addr(host)) == INADDR_NONE) { /* Oh well, a good try :-) */

        /* Now try a name look up with gethostbyname */

    if ((hp = gethostbyname(host)) == NULL) { /* Not in DNS */

        /* Try NetBIOS name lookup, how the hell do we do that? */

      RFCNB_errno = RFCNBE_BadName;   /* Is this right? */
      RFCNB_saved_errno = errno;
      return(RFCNBE_Bad);

    }
    else {  /* We got a name */

       memcpy((void *)Dest_IP, (void *)hp -> h_addr_list[0], sizeof(struct in_addr));

    }
  }
  else { /* It was an IP address */

    memcpy((void *)Dest_IP, (void *)&addr, sizeof(struct in_addr));

  }

  return 0;

}

/* Disconnect the TCP connection to the server */

int RFCNB_Close(int socket)

{

  close(socket);

  /* If we want to do error recovery, here is where we put it */

  return 0;

}

/* Connect to the server specified in the IP address.
   Not sure how to handle socket options etc.         */

int RFCNB_IP_Connect(struct in_addr Dest_IP, int port)

{ struct sockaddr_in Socket;
  int fd;

  /* Create a socket */

  if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0) { /* Handle the error */

    RFCNB_errno = RFCNBE_BadSocket;
    RFCNB_saved_errno = errno;
    return(RFCNBE_Bad);
    } 

  bzero((char *)&Socket, sizeof(Socket));
  memcpy((char *)&Socket.sin_addr, (char *)&Dest_IP, sizeof(Dest_IP));

  Socket.sin_port = htons(port);
  Socket.sin_family = PF_INET;

  /* Now connect to the destination */

  if (connect(fd, (struct sockaddr *)&Socket, sizeof(Socket)) < 0) { /* Error */

    close(fd);
    RFCNB_errno = RFCNBE_ConnectFailed;
    RFCNB_saved_errno = errno;
    return(RFCNBE_Bad);
    }

  return(fd);

}

/* handle the details of establishing the RFCNB session with remote 
   end 

*/

int RFCNB_Session_Req(struct RFCNB_Con *con, 
		      char *Called_Name, 
		      char *Calling_Name,
		      BOOL *redirect,
		      struct in_addr *Dest_IP,
		      int * port)

{ char *sess_pkt;

  /* Response packet should be no more than 9 bytes, make 16 jic */
/* 
  char ln1[16], ln2[16];
  char n1[32], n2[32]; */
  char resp[16];
  int len;
  struct RFCNB_Pkt *pkt, res_pkt;

  /* We build and send the session request, then read the response */

  pkt = RFCNB_Alloc_Pkt(RFCNB_Pkt_Sess_Len);

  if (pkt == NULL) {

    return(RFCNBE_Bad);  /* Leave the error that RFCNB_Alloc_Pkt gives) */

  }

  sess_pkt = pkt -> data;    /* Get pointer to packet proper */

  sess_pkt[RFCNB_Pkt_Type_Offset]  = RFCNB_SESSION_REQUEST;
  RFCNB_Put_Pkt_Len(sess_pkt, RFCNB_Pkt_Sess_Len-RFCNB_Pkt_Hdr_Len);
  sess_pkt[RFCNB_Pkt_N1Len_Offset] = 32;
  sess_pkt[RFCNB_Pkt_N2Len_Offset] = 32;

  RFCNB_CvtPad_Name(Called_Name, (sess_pkt + RFCNB_Pkt_Called_Offset));
  RFCNB_CvtPad_Name(Calling_Name, (sess_pkt + RFCNB_Pkt_Calling_Offset));

  /* Now send the packet */

#ifdef RFCNB_DEBUG

  fprintf(stderr, "Sending packet: ");
  
#endif

  if ((len = RFCNB_Put_Pkt(con, pkt, RFCNB_Pkt_Sess_Len)) < 0) {

    return(RFCNBE_Bad);       /* Should be able to write that lot ... */

    }

#ifdef RFCNB_DEBUG

  fprintf(stderr, "Getting packet.\n");

#endif

  res_pkt.data = resp;
  res_pkt.len  = sizeof(resp);
  res_pkt.next = NULL;

  if ((len = RFCNB_Get_Pkt(con, &res_pkt, sizeof(resp))) < 0) {

    return(RFCNBE_Bad);

  }

  /* Now analyze the packet ... */

  switch (RFCNB_Pkt_Type(resp)) {

    case RFCNB_SESSION_REJ:         /* Didnt like us ... too bad */

      /* Why did we get rejected ? */
    
      switch (CVAL(resp,RFCNB_Pkt_Error_Offset)) {

      case 0x80: 
	RFCNB_errno = RFCNBE_CallRejNLOCN;
	break;
      case 0x81:
	RFCNB_errno = RFCNBE_CallRejNLFCN;
	break;
      case 0x82:
	RFCNB_errno = RFCNBE_CallRejCNNP;
	break;
      case 0x83:
	RFCNB_errno = RFCNBE_CallRejInfRes;
	break;
      case 0x8F:
	RFCNB_errno = RFCNBE_CallRejUnSpec;
	break;
      default:
	RFCNB_errno = RFCNBE_ProtErr;
	break;
      }

      return(RFCNBE_Bad);
      break;

    case RFCNB_SESSION_ACK:        /* Got what we wanted ...      */

      return(0);
      break;

    case RFCNB_SESSION_RETARGET:   /* Go elsewhere                */

      *redirect = TRUE;       /* Copy port and ip addr       */

      memcpy(Dest_IP, (resp + RFCNB_Pkt_IP_Offset), sizeof(struct in_addr));
      *port = SVAL(resp, RFCNB_Pkt_Port_Offset);

      return(0);
      break;

    default:  /* A protocol error */

      RFCNB_errno = RFCNBE_ProtErr;
      return(RFCNBE_Bad);
      break;
    }
}