/*
 *  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.
 */

/*
    mstcp.c

    This file was written by Richard Dawe.

    ---

    Description:

        This file obtains key TCP/IP settings from the registry using Alfons
    Hoogervorst's registry-access code. This allows functions such as
    getdomainname and the resolving library to work.

        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 <stdlib.h>
#include <string.h>

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

char *mstcp_getkeystr (char *name);

/* Save some typing - this is the root key for all the settings that we need */
#define MSTCP_KEY "System\\CurrentControlSet\\Services\\VxD\\MSTCP"

/* --------------------
   - mstcp_dnsenabled -
   -------------------- */

/* If the DNS is enabled, 1 is returned. If it isn't, 0 is returned.
   On error, -1 is returned. */

int mstcp_dnsenabled (void)
{
    int ret;
    char *p = NULL;

    /* Get the EnableDNS key under the MSTCP one */
    p = mstcp_getkeystr("EnableDNS");

    /* If there is no key, assume it's OK to use the DNS */
    if (p == NULL) return(1);

    /* Else convert to a string and return */
    ret = atoi(p);
    free(p);
    return(ret);
}

/* ---------------------
   - mstcp_getdnsaddrs -
   --------------------- */

/* This function will return the IP addresses for the DNS. On error NULL is
   returned. */

char **mstcp_getdnsaddrs (void)
{
    HKEY    hkey = NULL;                /* IM: for warnings */
    DWORD   keytype = REG_SZ;
    char    buffer[256];
    char    *q;                         /* Temp. pointers */
    char    **mstcp_dnsaddrs;           /* MSTCP DNS addresses */
    DWORD   buffersize = sizeof(buffer);
    DWORD   ret;
    int     nodns;                      /* No. of DNS's */
    int     i;

    /* Check that the DNS is enabled */
    if (mstcp_dnsenabled() != 1) return(NULL);

    /* Get the MSTCP registry key handle */
    ret = RegOpenKey(HKEY_LOCAL_MACHINE, MSTCP_KEY, &hkey); /* IM: added & before hkey */
    if (ret != ERROR_SUCCESS) return(NULL);

    /* Get the NameServer subkey */
    ret = RegQueryValueEx(hkey, "NameServer", NULL, &keytype, (LPBYTE) buffer, &buffersize);
    RegCloseKey(hkey);

    if (ret != ERROR_SUCCESS) return(NULL);

    /* Build a list of strings */
    q = buffer; nodns = 0;
    while ((q = strchr(q, ',')) != NULL) { nodns++; q++; }
    nodns++;    /* One more DNS than commas */

    mstcp_dnsaddrs = malloc((nodns + 1) * sizeof(char *));
    if (mstcp_dnsaddrs == NULL) return(NULL);
    memset(mstcp_dnsaddrs, 0, (nodns + 1) * sizeof(char *));

    /* The DNS addresses are stored in a comma separated list, so unseparate
       them & copy into mstcp_dnsaddrs */
    q = strtok(buffer, ","); mstcp_dnsaddrs[0] = strdup(q);

    for (   i = 1;
            (q = strtok(NULL, ",")) != NULL;
            mstcp_dnsaddrs[i] = strdup(q), i++  ) {;}

    /* Finito */
    return(mstcp_dnsaddrs);
}

/* -------------------
   - mstcp_getkeystr -
   ------------------- */

/* This returns the string stored under a MSTCP key with the specified
   'name'. */

char *mstcp_getkeystr (char *name)
{
    HKEY    hkey = NULL;	/* IM: for warnings */
    DWORD   keytype = REG_SZ;
    char    buffer[256];
    DWORD   buffersize = sizeof(buffer);
    DWORD   ret;

    /* Get the MSTCP registry key handle */
    ret = RegOpenKey(HKEY_LOCAL_MACHINE, MSTCP_KEY, &hkey);   /* IM: Added & before hkey */
    if (ret != ERROR_SUCCESS) return(NULL);

    /* Get the NameServer subkey */
    ret = RegQueryValueEx(hkey, name, NULL, &keytype, (LPBYTE) buffer, &buffersize);
    RegCloseKey(hkey);

    if (ret != ERROR_SUCCESS) return(NULL); else return(strdup(buffer));
}

/* ------------------
   - mstcp_hostname -
   ------------------ */

/* This function finds the host name from the MSTCP subkey, if possible. */
char *mstcp_gethostname (void) { return(mstcp_getkeystr("HostName")); }

/* -----------------------
   - mstcp_getdomainname -
   ----------------------- */

/* This function finds the domain name from the MSTCP subkey, if possible. */
char *mstcp_getdomainname (void) { return(mstcp_getkeystr("Domain")); }