/*
 *  libsocket - BSD socket like library for DJGPP
 *  Copyright 1997, 1998 by Indrek Mandre
 *  Copyright 1997, 1998 by Richard Dawe
 *
 *  This library is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU Library General Public License as published
 *  by the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This library 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
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
    ras.c

    This file was written by Richard Dawe.

    ---

    Description:

        This file obtains key network transport settings from the registry
    using the RegDos Group's registry-access code. The keys dealt with are from
    the keys:

    . HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\RemoteAccess
    . HKEY_CURRENT_USER\RemoteAccess

    The information used to write this code was supplied by Alfons Hoogervorst.
    See the file ipdata.txt that should be in <library root>/misc/docs/.

        Please note that functions that return char *'s use strdup to allocate
    memory, so any code using these functions should free up this memory after
    usage.
*/

/* Include some files */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>

#include <lsck/ras.h>
#include "regdos.h"

/* Save some typing - this is the root key for all the settings that we need */
#define RAS_KEY    "System\\CurrentControlSet\\Services\\RemoteAccess"
/*#define RAS_USERKEY "RemoteAccess"*//* Pointless; off HKEY_CURRENT_USER btw */

/* According to MS SDK headers - used for maximum registry key length */
#ifndef MAX_PATH
#define MAX_PATH 260
#endif

/* --------------
   - ras_active -
   -------------- */

/* This returns 1 if there is an active dial-up connection. */

int ras_active (void)
{
    HKEY hkey = NULL;
    DWORD valuetype = REG_DWORD;
    DWORD value = 0;
    DWORD valuesize = sizeof(value);
    DWORD ret;

    /* Open the RAS key */
    ret = RegOpenKey(HKEY_LOCAL_MACHINE, RAS_KEY, &hkey);
    if (ret != ERROR_SUCCESS) return(0);

    /* Get the value */
    ret = RegQueryValueEx(hkey, "Remote Connection", NULL,
                          &valuetype, (LPSTR) &value, &valuesize);
    if (ret != ERROR_SUCCESS) value = 0;    /* Just to be safe, set value */

    /* Close the key */
    RegCloseKey(hkey);

    /* Return the value */
    return(value);
}

/* ---------------------------
   - ras_getdefaultphonebook -
   --------------------------- */

/* This returns the name of the default phonebook from
   HKEY_CURRENT_USER\RemoteAccess\Default. This is used by ras_getdata()
   below. */

char *ras_getdefaultphonebook (void)
{
    HKEY  hkey = NULL;
    DWORD buffertype = REG_SZ;
    char  buffer[MAX_PATH];
    DWORD buffersize = sizeof(buffer);
    DWORD ret;

    /* Open the key */
    ret = RegOpenKey(HKEY_CURRENT_USER, "RemoteAccess", &hkey);
    if (ret != ERROR_SUCCESS) return(NULL);

    /* Get the phonebook name */
    ret = RegQueryValueEx(hkey, "Default", NULL, &buffertype, buffer, &buffersize);
    if (ret != ERROR_SUCCESS) return(NULL);

    /* Return it */
    return(strdup(buffer));
}

/* ---------------
   - ras_getdata -
   --------------- */

/* This parses the data stored in
   HKEY_CURRENT_USER\RemoteAccess\Profile\<Default phonebook name>. It fills
   the passed structure with the parsed data. If successful, 1 is returned,
   else 0. It determines whether the local IP address is fixed (& what it is)
   and whether DNS addresses were given (& what they are). */

int ras_getdata (ras_data *rd)
{
    char *pbname = NULL;
    HKEY  hkey = NULL;
    DWORD buffertype = REG_BINARY;
    char  buffer[50];                   /* 50 bytes is the maximum data size */
    DWORD buffersize = sizeof(buffer);
    DWORD ret;
    long  convaddr;                     /* Used for IP addr. conversion      */

    /* Duh! No RAS connection active! */
    if (!ras_active()) return(0);

    /* Get the default phonebook name */
    pbname = ras_getdefaultphonebook();
    if (pbname == NULL) return(0);  /* None! */

    /* Open the key and get the data */
    ret = RegOpenKey(HKEY_CURRENT_USER, "RemoteAccess\\Profile", &hkey);
    if (ret != ERROR_SUCCESS) return(0);

    ret = RegQueryValueEx(hkey, pbname, NULL, &buffertype, buffer, &buffersize);
    if (ret != ERROR_SUCCESS) return(0);

    /* See what IP data is present */
    memset(rd, 0, sizeof(ras_data));

    if (buffer[0x04] & 0x01) rd->ip_fixed = 1;          /* Local IP addr. */
    if (buffer[0x04] & 0x02) rd->ip_dns_specified = 1;  /* DNS IP addr's  */

    if (rd->ip_fixed) {
        memcpy(&convaddr, buffer + 0x08, 4);    /* IP addr. = 4-byte ulong */
        rd->ip_machine.s_addr = htons(convaddr);
    }

    if (rd->ip_dns_specified) {
        /* Hmm...dangerous code? */
        memcpy(&convaddr, buffer + 0x0C, 4);
        if ( (rd->ip_dns[rd->ip_dns_count].s_addr = htons(convaddr)) != 0)
            rd->ip_dns_count++;

        memcpy(&convaddr, buffer + 0x10, 4);
        if ( (rd->ip_dns[rd->ip_dns_count].s_addr = htons(convaddr)) != 0)
            rd->ip_dns_count++;
    }

    /* OK */
    return(1);
}

/* -------------------
   - ras_getdnsaddrs -
   ------------------- */

char **ras_getdnsaddrs (void)
{
    char     **p = NULL;
    ras_data rd;
    int      i;

    /* Get the RAS data */
    if (!ras_getdata(&rd)) return(NULL);

    /* Allocate pointers first */
    p = malloc((rd.ip_dns_count + 1) * sizeof(char *));
    if (p == NULL) return(NULL);
    memset(p, 0, (rd.ip_dns_count + 1) * sizeof(char *));

    /* Fill with DNS IP addresses */
    for (i = 0; i < rd.ip_dns_count; i++) {
        p[i] = strdup(inet_ntoa(rd.ip_dns[i]));
    }

    p[rd.ip_dns_count + 1] = NULL;

    return(p);
}