Initial Contribution

libc/netbsd/resolv/res_state.c

@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+#include <sys/cdefs.h>
+#include <sys/types.h>
+#include <arpa/inet.h>
+#include "arpa_nameser.h"
+#include <netdb.h>
+#include "resolv_private.h"
+#include "resolv_cache.h"
+#include <pthread.h>
+#include <stdlib.h>
+
+#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
+#include <sys/_system_properties.h>
+
+static pthread_key_t   _res_key;
+static pthread_once_t  _res_once;
+
+typedef struct {
+    int                    _h_errno;
+    struct __res_state     _nres[1];
+    unsigned               _serial;
+    struct prop_info*      _pi;
+    struct hostent*        _hostent;
+    struct res_static      _rstatic[1];
+} _res_thread;
+
+static _res_thread*
+_res_thread_alloc(void)
+{
+    _res_thread*  rt = malloc(sizeof(*rt));
+
+    if (rt) {
+        rt->_h_errno = 0;
+        /* Special system property which tracks any changes to 'net.*'. */
+        rt->_serial = 0;
+        rt->_pi = (struct prop_info*) __system_property_find("net.change");
+        if (rt->_pi) {
+            rt->_serial = rt->_pi->serial;
+        }
+        if ( res_ninit( rt->_nres ) < 0 ) {
+            free(rt);
+            rt = NULL;
+        }
+        rt->_hostent = NULL;
+        memset(rt->_rstatic, 0, sizeof rt->_rstatic);
+    }
+    return rt;
+}
+
+static void
+_res_static_done( res_static  rs )
+{
+    /* fortunately, there is nothing to do here, since the
+     * points in h_addr_ptrs and host_aliases should all
+     * point to 'hostbuf'
+     */
+    if (rs->hostf) {  /* should not happen in theory, but just be safe */
+        fclose(rs->hostf);
+        rs->hostf = NULL;
+    }
+    free(rs->servent.s_aliases);
+}
+
+static void
+_res_thread_free( void*  _rt )
+{
+    _res_thread*  rt = _rt;
+
+    _res_static_done(rt->_rstatic);
+    _resolv_hostent_free(rt->_hostent);
+    res_ndestroy(rt->_nres);
+    free(rt);
+}
+
+static void
+_res_init_key( void )
+{
+    pthread_key_create( &_res_key, _res_thread_free );
+}
+
+static _res_thread*
+_res_thread_get(void)
+{
+    _res_thread*  rt;
+    pthread_once( &_res_once, _res_init_key );
+    rt = pthread_getspecific( _res_key );
+    if (rt == NULL) {
+        if ((rt = _res_thread_alloc()) == NULL) {
+            return NULL;
+        }
+        rt->_h_errno = 0;
+        rt->_serial = 0;
+        pthread_setspecific( _res_key, rt );
+    }
+    /* Check the serial value for any chanes to net.* properties. */
+    if (rt->_pi == NULL) {
+        rt->_pi = (struct prop_info*) __system_property_find("net.change");
+    }
+    if (rt->_pi == NULL || rt->_serial == rt->_pi->serial) {
+        return rt;
+    }
+    rt->_serial = rt->_pi->serial;
+    /* Reload from system properties. */
+    if ( res_ninit( rt->_nres ) < 0 ) {
+        free(rt);
+        rt = NULL;
+        pthread_setspecific( _res_key, rt );
+    }
+    return rt;
+}
+
+struct __res_state _nres;
+
+#if 0
+struct resolv_cache*
+__get_res_cache(void)
+{
+    _res_thread*  rt = _res_thread_get();
+
+    if (!rt)
+        return NULL;
+
+    if (!rt->_cache) {
+        rt->_cache = _resolv_cache_create();
+    }
+    return rt->_cache;
+}
+#endif
+
+int*
+__get_h_errno(void)
+{
+    _res_thread*  rt    = _res_thread_get();
+    static int    panic = NETDB_INTERNAL;
+
+    return rt ? &rt->_h_errno : &panic;
+}
+
+res_state
+__res_get_state(void)
+{
+    _res_thread*  rt = _res_thread_get();
+
+    return rt ? rt->_nres : NULL;
+}
+
+void
+__res_put_state(res_state res)
+{
+    /* nothing to do */
+    res=res;
+}
+
+struct hostent**
+__get_res_cache_hostent_p(void)
+{
+    _res_thread*  rt = _res_thread_get();
+
+    return rt ? &rt->_hostent : NULL;
+}
+
+res_static
+__res_get_static(void)
+{
+    _res_thread*  rt = _res_thread_get();
+
+    return rt ? rt->_rstatic : NULL;
+}