/* UNIX RFCNB (RFC1001/RFC1002) NetBIOS implementation

   Version 1.0
   Session 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 <malloc.h>
#include <string.h>
#include <stdlib.h>

int RFCNB_errno = 0;
int RFCNB_saved_errno = 0;
#define RFCNB_ERRNO

#include "std-includes.h"
#include <netinet/tcp.h>
#include "rfcnb-priv.h"
#include "rfcnb-util.h"
#include "rfcnb-io.h"

int RFCNB_Stats[RFCNB_MAX_STATS];

int RFCNB_Free_Pkt(struct RFCNB_Pkt *pkt);

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

/* Set up a session with a remote name. We are passed Called_Name as a
   string which we convert to a NetBIOS name, ie space terminated, up to
   16 characters only if we need to. If Called_Address is not empty, then
   we use it to connect to the remote end, but put in Called_Name ... Called 
   Address can be a DNS based name, or a TCP/IP address ...
*/

void *RFCNB_Call(char *Called_Name, char *Calling_Name, char *Called_Address,
		 int port)

{ struct RFCNB_Con *con;
  struct in_addr Dest_IP;
  int Client;
  BOOL redirect; struct redirect_addr *redir_addr;
  char *Service_Address;

  /* Now, we really should look up the port in /etc/services ... */

  if (port == 0) port = RFCNB_Default_Port;

  /* Create a connection structure first */

  if ((con = (struct RFCNB_Con *)malloc(sizeof(struct RFCNB_Con))) == NULL) { /* Error in size */

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

    }
 
  con -> fd = -0;             /* no descriptor yet */
  con -> rfc_errno = 0;           /* no error yet */
  con -> timeout = 0;         /* no timeout   */
  con -> redirects = 0;
  con -> redirect_list = NULL; /* Fix bug still in version 0.50 */

  /* Resolve that name into an IP address */

  Service_Address = Called_Name;
  if (strcmp(Called_Address, "") != 0) { /* If the Called Address = "" */
    Service_Address = Called_Address;
  }

  if ((errno = RFCNB_Name_To_IP(Service_Address, &Dest_IP)) < 0) { /* Error */

    /* No need to modify RFCNB_errno as it was done by RFCNB_Name_To_IP */

    return(NULL);

    }

  /* Now connect to the remote end */

  redirect = TRUE;     /* Fudge this one so we go once through */

  while (redirect) {   /* Connect and get session info etc */

    redirect = FALSE;  /* Assume all OK */

    /* Build the redirect info. First one is first addr called */
    /* And tack it onto the list of addresses we called        */

    if ((redir_addr = (struct redirect_addr *)malloc(sizeof(struct redirect_addr))) == NULL) { /* Could not get space */
      
      RFCNB_errno = RFCNBE_NoSpace;
      RFCNB_saved_errno = errno;
      return(NULL);

    }

    memcpy((char *)&(redir_addr -> ip_addr), (char *)&Dest_IP, sizeof(Dest_IP));
    redir_addr -> port = port;
    redir_addr -> next = NULL;

    if (con -> redirect_list == NULL) { /* Stick on head */

      con -> redirect_list = con -> last_addr = redir_addr;

    } else {

      con -> last_addr -> next = redir_addr;
      con -> last_addr = redir_addr;

    }

    /* Now, make that connection */

    if ((Client = RFCNB_IP_Connect(Dest_IP, port)) < 0) { /* Error */

      /* No need to modify RFCNB_errno as it was done by RFCNB_IP_Connect */

      return(NULL);

      }

    con -> fd = Client;

    /* Now send and handle the RFCNB session request              */
    /* If we get a redirect, we will comeback with redirect true 
       and a new IP address in DEST_IP                            */

    if ((errno = RFCNB_Session_Req(con, 
				   Called_Name,
   				   Calling_Name,
				   &redirect, &Dest_IP, &port)) < 0) {

      /* No need to modify RFCNB_errno as it was done by RFCNB_Session.. */

      return(NULL);

      }

    if (redirect) {

      /* We have to close the connection, and then try again */

      (con -> redirects)++;

      RFCNB_Close(con -> fd);  /* Close it */

      }
    }

  return(con);

}

/* We send a packet to the other end ... for the moment, we treat the 
   data as a series of pointers to blocks of data ... we should check the
   length ... */

int RFCNB_Send(struct RFCNB_Con *Con_Handle, struct RFCNB_Pkt *udata, int Length)

{ struct RFCNB_Pkt *pkt; char *hdr;
  int len;

  /* Plug in the header and send the data */

  pkt = RFCNB_Alloc_Pkt(RFCNB_Pkt_Hdr_Len);

  if (pkt == NULL) {

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

  }

  pkt -> next = udata;   /* The user data we want to send */

  hdr = pkt -> data;

  /* Following crap is for portability across multiple UNIX machines */

  *(hdr + RFCNB_Pkt_Type_Offset)  = RFCNB_SESSION_MESSAGE;
  RFCNB_Put_Pkt_Len(hdr, Length);

#ifdef RFCNB_DEBUG

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

  if ((len = RFCNB_Put_Pkt(Con_Handle, pkt, Length + RFCNB_Pkt_Hdr_Len)) < 0) {

    /* No need to change RFCNB_errno as it was done by put_pkt ...     */

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

  /* Now we have sent that lot, let's get rid of the RFCNB Header and return */

  pkt -> next = NULL;

  RFCNB_Free_Pkt(pkt);

  return(len);

}

/* We pick up a message from the internet ... We have to worry about 
   non-message packets ...                                           */

int RFCNB_Recv(void *con_Handle, struct RFCNB_Pkt *Data, int Length)

{ struct RFCNB_Pkt *pkt;
/*  struct RFCNB_Hdr *hdr; */
  int ret_len;

  if (con_Handle == NULL){

    RFCNB_errno = RFCNBE_BadHandle;
    RFCNB_saved_errno = errno;
    return(RFCNBE_Bad);

  }

  /* Now get a packet from below. We allocate a header first */

  /* Plug in the header and send the data */

  pkt = RFCNB_Alloc_Pkt(RFCNB_Pkt_Hdr_Len);

  if (pkt == NULL) {

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

  }

  pkt -> next = Data;  /* Plug in the data portion */

  if ((ret_len = RFCNB_Get_Pkt(con_Handle, pkt, Length + RFCNB_Pkt_Hdr_Len)) < 0) {

#ifdef RFCNB_DEBUG
    fprintf(stderr, "Bad packet return in RFCNB_Recv... \n");
#endif

    return(RFCNBE_Bad);

  }

  /* We should check that we go a message and not a keep alive */

  pkt -> next = NULL;

  RFCNB_Free_Pkt(pkt);

  return(ret_len);

}

/* We just disconnect from the other end, as there is nothing in the RFCNB */
/* protocol that specifies any exchange as far as I can see                */

int RFCNB_Hangup(struct RFCNB_Con *con_Handle)

{

  if (con_Handle != NULL) {
    RFCNB_Close(con_Handle -> fd);  /* Could this fail? */
    free(con_Handle);
  }

  return 0;


}

/* Set TCP_NODELAY on the socket                                          */

int RFCNB_Set_Sock_NoDelay(struct RFCNB_Con *con_Handle, BOOL yn)

{

  return(setsockopt(con_Handle -> fd, IPPROTO_TCP, TCP_NODELAY, 
		    (char *)&yn, sizeof(yn)));

}


/* Listen for a connection on a port???, when                             */
/* the connection comes in, we return with the connection                 */

void *RFCNB_Listen()

{
  return NULL;
}

/* Pick up the last error response as a string, hmmm, this routine should */
/* have been different ...                                                */

void RFCNB_Get_Error(char *buffer, int buf_len)

{

  if (RFCNB_saved_errno <= 0) {
    sprintf(buffer, "%s", RFCNB_Error_Strings[RFCNB_errno]);
  }
  else {
    sprintf(buffer, "%s\n\terrno:%s", RFCNB_Error_Strings[RFCNB_errno],
	    strerror(RFCNB_saved_errno));
  }

}

/* Pick up the last error response and returns as a code                 */

int RFCNB_Get_Last_Error()

{

  return(RFCNB_errno);

}

/* Pick up saved errno as well */

int RFCNB_Get_Last_Errno()

{

  return(RFCNB_saved_errno);

}

/* Pick up the last error response and return in string ...             */

int RFCNB_Get_Error_Msg(int code, char *msg_buf, int len)

{

  strncpy(msg_buf, RFCNB_Error_Strings[abs(code)], len);
  return 0;
}

/* Register a higher level protocol print routine */

void RFCNB_Register_Print_Routine(void (*fn)(FILE *, int, struct RFCNB_Pkt *, int, int))

{

  Prot_Print_Routine = fn;

}