lwres/win32/lwconfig.c

	lwconfig.c revision 0c27b3fe77ac1d5094ba3521e8142d9e7973133f
/*
 * Copyright (C) 2002, 2004, 2006, 2007, 2013, 2016  Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

/* $Id: lwconfig.c,v 1.7 2007/12/14 01:40:42 marka Exp $ */

/*
 * We do this so that we may incorporate everything in the main routines
 * so that we can take advantage of the fixes and changes made there
 * without having to add them twice. We can then call the parse routine
 * if there is a resolv.conf file and fetch our own data from the
 * Windows environment otherwise.
 */

/*
 * Note that on Win32 there is normally no resolv.conf since all information
 * is stored in the registry. Therefore there is no ordering like the
 * contents of resolv.conf. Since the "search" or "domain" keyword, on
 * Win32 if a search list is found it is used, otherwise the domain name
 * is used since they are mutually exclusive. The search list can be entered
 * in the DNS tab of the "Advanced TCP/IP settings" window under the same place
 * that you add your nameserver list.
 */

#define lwres_conf_parse generic_lwres_conf_parse
#include "../lwconfig.c"
#undef lwres_conf_parse

#include <iphlpapi.h>

#define TCPIP_SUBKEY    \
    "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters"

void
get_win32_searchlist(lwres_context_t *ctx) {
    HKEY hKey;
    BOOL keyFound = TRUE;
    char searchlist[MAX_PATH];
    DWORD searchlen = MAX_PATH;
    char *cp;
    lwres_conf_t *confdata;

    REQUIRE(ctx != NULL);
    confdata = &ctx->confdata;

    memset(searchlist, 0, MAX_PATH);
    if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, TCPIP_SUBKEY, 0, KEY_READ, &hKey)
        != ERROR_SUCCESS)
        keyFound = FALSE;

    if (keyFound == TRUE) {
        /* Get the named directory */
        if (RegQueryValueEx(hKey, "SearchList", NULL, NULL,
            (LPBYTE)searchlist, &searchlen) != ERROR_SUCCESS)
            keyFound = FALSE;
        RegCloseKey(hKey);
    }

    confdata->searchnxt = 0;

    if (!keyFound)
        return;

    cp = strtok((char *)searchlist, ", \0");
    while (cp != NULL) {
        if (confdata->searchnxt == LWRES_CONFMAXSEARCH)
            break;
        if (strlen(cp) <= MAX_PATH && strlen(cp) > 0) {
            confdata->search[confdata->searchnxt] = lwres_strdup(ctx, cp);
            if (confdata->search[confdata->searchnxt] != NULL)
                confdata->searchnxt++;
        }
        cp = strtok(NULL, ", \0");
    }
}

lwres_result_t
lwres_conf_parse(lwres_context_t *ctx, const char *filename) {
    lwres_result_t ret;
    lwres_conf_t *confdata;
    FIXED_INFO * FixedInfo;
    ULONG    BufLen = sizeof(FIXED_INFO);
    DWORD    dwRetVal;
    IP_ADDR_STRING *pIPAddr;

    REQUIRE(ctx != NULL);
    confdata = &ctx->confdata;
    REQUIRE(confdata != NULL);

    /* Use the resolver if there is one */
    ret = generic_lwres_conf_parse(ctx, filename);
    if ((ret != LWRES_R_NOTFOUND && ret != LWRES_R_SUCCESS) ||
        (ret == LWRES_R_SUCCESS && confdata->nsnext > 0))
        return (ret);

    /*
     * We didn't get any nameservers so we need to do this ourselves
     */
    FixedInfo = (FIXED_INFO *) GlobalAlloc(GPTR, BufLen);
    dwRetVal = GetNetworkParams(FixedInfo, &BufLen);
    if (dwRetVal == ERROR_BUFFER_OVERFLOW) {
        GlobalFree(FixedInfo);
        FixedInfo = GlobalAlloc(GPTR, BufLen);
        dwRetVal = GetNetworkParams(FixedInfo, &BufLen);
    }
    if (dwRetVal != ERROR_SUCCESS) {
        GlobalFree(FixedInfo);
        return (LWRES_R_FAILURE);
    }

    /* Get the search list from the registry */
    get_win32_searchlist(ctx);

    /* Use only if there is no search list */
    if (confdata->searchnxt == 0 && strlen(FixedInfo->DomainName) > 0) {
        confdata->domainname = lwres_strdup(ctx, FixedInfo->DomainName);
        if (confdata->domainname == NULL) {
            GlobalFree(FixedInfo);
            return (LWRES_R_FAILURE);
        }
    } else
        confdata->domainname = NULL;

    /* Get the list of nameservers */
    pIPAddr = &FixedInfo->DnsServerList;
    while (pIPAddr) {
        if (confdata->nsnext >= LWRES_CONFMAXNAMESERVERS)
            break;

        ret = lwres_create_addr(pIPAddr->IpAddress.String,
                &confdata->nameservers[confdata->nsnext++], 1);
        if (ret != LWRES_R_SUCCESS) {
            GlobalFree(FixedInfo);
            return (ret);
        }
        pIPAddr = pIPAddr ->Next;
    }

    GlobalFree(FixedInfo);
    return (LWRES_R_SUCCESS);
}