src/jdk.dns.client/windows/native/libresolver/DnsResolverConfiguration.c
branchaefimov-dns-client-branch
changeset 59100 b92aac38b046
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.dns.client/windows/native/libresolver/DnsResolverConfiguration.c	Thu Nov 14 23:13:47 2019 +0000
@@ -0,0 +1,304 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#include <stdlib.h>
+#include <windows.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <iprtrmib.h>
+#include <time.h>
+#include <assert.h>
+#include <iphlpapi.h>
+
+#include "jni_util.h"
+
+#define MAX_STR_LEN         256
+
+#define STS_NO_CONFIG       0x0             /* no configuration found */
+#define STS_SL_FOUND        0x1             /* search list found */
+#define STS_NS_FOUND        0x2             /* name servers found */
+#define STS_ERROR           -1              /* error return  lodConfig failed memory allccation failure*/
+
+#define IS_SL_FOUND(sts)    (sts & STS_SL_FOUND)
+#define IS_NS_FOUND(sts)    (sts & STS_NS_FOUND)
+
+/* JNI ids */
+static jfieldID searchlistID;
+static jfieldID nameserversID;
+
+/*
+ * Utility routine to append s2 to s1 with a space delimiter.
+ *  strappend(s1="abc", "def")  => "abc def"
+ *  strappend(s1="", "def")     => "def
+ */
+void strappend(char *s1, char *s2) {
+    size_t len;
+
+    if (s2[0] == '\0')                      /* nothing to append */
+        return;
+
+    len = strlen(s1)+1;
+    if (s1[0] != 0)                         /* needs space character */
+        len++;
+    if (len + strlen(s2) > MAX_STR_LEN)     /* insufficient space */
+        return;
+
+    if (s1[0] != 0) {
+        strcat(s1, " ");
+    }
+    strcat(s1, s2);
+}
+
+/*
+ * Windows 2000/XP
+ *
+ * Use registry approach based on settings described in Appendix C
+ * of "Microsoft Windows 2000 TCP/IP Implementation Details".
+ *
+ * DNS suffix list is obtained from SearchList registry setting. If
+ * this is not specified we compile suffix list based on the
+ * per-connection domain suffix.
+ *
+ * DNS name servers and domain settings are on a per-connection
+ * basic. We therefore enumerate the network adapters to get the
+ * names of each adapter and then query the corresponding registry
+ * settings to obtain NameServer/DhcpNameServer and Domain/DhcpDomain.
+ */
+static int loadConfig(char *sl, char *ns) {
+    IP_ADAPTER_INFO *adapterP;
+    ULONG size;
+    DWORD ret;
+    DWORD dwLen;
+    ULONG ulType;
+    char result[MAX_STR_LEN];
+    HANDLE hKey;
+    int gotSearchList = 0;
+
+    /*
+     * First see if there is a global suffix list specified.
+     */
+    ret = RegOpenKeyEx(HKEY_LOCAL_MACHINE,
+                       "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters",
+                       0,
+                       KEY_READ,
+                       (PHKEY)&hKey);
+    if (ret == ERROR_SUCCESS) {
+        dwLen = sizeof(result);
+        ret = RegQueryValueEx(hKey, "SearchList", NULL, &ulType,
+                             (LPBYTE)&result, &dwLen);
+        if (ret == ERROR_SUCCESS) {
+            assert(ulType == REG_SZ);
+            if (strlen(result) > 0) {
+                strappend(sl, result);
+                gotSearchList = 1;
+            }
+        }
+        RegCloseKey(hKey);
+    }
+
+    /*
+     * Ask the IP Helper library to enumerate the adapters
+     */
+    size = sizeof(IP_ADAPTER_INFO);
+    adapterP = (IP_ADAPTER_INFO *)malloc(size);
+    if (adapterP == NULL) {
+        return STS_ERROR;
+    }
+    ret = GetAdaptersInfo(adapterP, &size);
+    if (ret == ERROR_BUFFER_OVERFLOW) {
+        IP_ADAPTER_INFO *newAdapterP = (IP_ADAPTER_INFO *)realloc(adapterP, size);
+        if (newAdapterP == NULL) {
+            free(adapterP);
+            return STS_ERROR;
+        }
+        adapterP = newAdapterP;
+
+        ret = GetAdaptersInfo(adapterP, &size);
+    }
+
+    /*
+     * Iterate through the list of adapters as registry settings are
+     * keyed on the adapter name (GUID).
+     */
+    if (ret == ERROR_SUCCESS) {
+        IP_ADAPTER_INFO *curr = adapterP;
+        while (curr != NULL) {
+            char key[MAX_STR_LEN];
+
+            sprintf(key,
+                "SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters\\Interfaces\\%s",
+                curr->AdapterName);
+
+            ret = RegOpenKeyEx(HKEY_LOCAL_MACHINE,
+                               key,
+                               0,
+                               KEY_READ,
+                               (PHKEY)&hKey);
+            if (ret == ERROR_SUCCESS) {
+                DWORD enableDhcp = 0;
+
+                /*
+                 * Is DHCP enabled on this interface
+                 */
+                dwLen = sizeof(enableDhcp);
+                ret = RegQueryValueEx(hKey, "EnableDhcp", NULL, &ulType,
+                                     (LPBYTE)&enableDhcp, &dwLen);
+
+                /*
+                 * If we don't have the suffix list when get the Domain
+                 * or DhcpDomain. If DHCP is enabled then Domain overides
+                 * DhcpDomain
+                 */
+                if (!gotSearchList) {
+                    result[0] = '\0';
+                    dwLen = sizeof(result);
+                    ret = RegQueryValueEx(hKey, "Domain", NULL, &ulType,
+                                         (LPBYTE)&result, &dwLen);
+                    if (((ret != ERROR_SUCCESS) || (strlen(result) == 0)) &&
+                        enableDhcp) {
+                        dwLen = sizeof(result);
+                        ret = RegQueryValueEx(hKey, "DhcpDomain", NULL, &ulType,
+                                              (LPBYTE)&result, &dwLen);
+                    }
+                    if (ret == ERROR_SUCCESS) {
+                        assert(ulType == REG_SZ);
+                        strappend(sl, result);
+                    }
+                }
+
+                /*
+                 * Get DNS servers based on NameServer or DhcpNameServer
+                 * registry setting. If NameServer is set then it overrides
+                 * DhcpNameServer (even if DHCP is enabled).
+                 */
+                result[0] = '\0';
+                dwLen = sizeof(result);
+                ret = RegQueryValueEx(hKey, "NameServer", NULL, &ulType,
+                                     (LPBYTE)&result, &dwLen);
+                if (((ret != ERROR_SUCCESS) || (strlen(result) == 0)) &&
+                    enableDhcp) {
+                    dwLen = sizeof(result);
+                    ret = RegQueryValueEx(hKey, "DhcpNameServer", NULL, &ulType,
+                                          (LPBYTE)&result, &dwLen);
+                }
+                if (ret == ERROR_SUCCESS) {
+                    assert(ulType == REG_SZ);
+                    strappend(ns, result);
+                }
+
+                /*
+                 * Finished with this registry key
+                 */
+                RegCloseKey(hKey);
+            }
+
+            /*
+             * Onto the next adapeter
+             */
+            curr = curr->Next;
+        }
+    }
+
+    /*
+     * Free the adpater structure
+     */
+    if (adapterP) {
+        free(adapterP);
+    }
+
+    return STS_SL_FOUND & STS_NS_FOUND;
+}
+
+
+/*
+ * Initialize JNI field IDs.
+ */
+JNIEXPORT void JNICALL
+Java_jdk_dns_conf_DnsResolverConfiguration_init0(JNIEnv *env, jclass cls)
+{
+    searchlistID = (*env)->GetStaticFieldID(env, cls, "os_searchlist",
+                                      "Ljava/lang/String;");
+    CHECK_NULL(searchlistID);
+    nameserversID = (*env)->GetStaticFieldID(env, cls, "os_nameservers",
+                                      "Ljava/lang/String;");
+}
+
+/*
+ * Class:     jdk_dns_conf_DnsResolverConfguration
+ * Method:    loadConfig0
+ * Signature: ()V
+ */
+JNIEXPORT void JNICALL
+Java_jdk_dns_conf_DnsResolverConfiguration_loadDNSconfig0(JNIEnv *env, jclass cls)
+{
+    char searchlist[MAX_STR_LEN];
+    char nameservers[MAX_STR_LEN];
+    jstring obj;
+
+    searchlist[0] = '\0';
+    nameservers[0] = '\0';
+
+    if (loadConfig(searchlist, nameservers) != STS_ERROR) {
+
+        /*
+         * Populate static fields in jdk.dns.conf.ResolverConfiguration
+         */
+        obj = (*env)->NewStringUTF(env, searchlist);
+        CHECK_NULL(obj);
+        (*env)->SetStaticObjectField(env, cls, searchlistID, obj);
+
+        obj = (*env)->NewStringUTF(env, nameservers);
+        CHECK_NULL(obj);
+        (*env)->SetStaticObjectField(env, cls, nameserversID, obj);
+    } else {
+        JNU_ThrowOutOfMemoryError(env, "native memory allocation failed");
+    }
+}
+
+
+/*
+ * Class:     jdk_dns_conf_DnsResolverConfiguration
+ * Method:    notifyAddrChange0
+ * Signature: ()I
+ */
+JNIEXPORT jint JNICALL
+Java_jdk_dns_conf_DnsResolverConfiguration_notifyAddrChange0(JNIEnv *env, jclass cls)
+{
+    OVERLAPPED ol;
+    HANDLE h;
+    DWORD rc, xfer;
+
+    ol.hEvent = (HANDLE)0;
+    rc = NotifyAddrChange(&h, &ol);
+    if (rc == ERROR_IO_PENDING) {
+        rc = GetOverlappedResult(h, &ol, &xfer, TRUE);
+        if (rc != 0) {
+            return 0;   /* address changed */
+        }
+    }
+
+    /* error */
+    return -1;
+}