[net][sal] Add SAL (socket abstraction layer) framework

components/net/sal_socket/socket/net_netdb.c

@@ -0,0 +1,55 @@
+/*
+ * File      : net_netdb.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2015, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2015-02-17     Bernard      First version
+ * 2108-05-24     ChenYong     Add socket abstraction layer
+ */
+
+#include <rtthread.h>
+
+#include <netdb.h>
+
+struct hostent *gethostbyname(const char *name)
+{
+    return sal_gethostbyname(name);
+}
+RTM_EXPORT(gethostbyname);
+
+int gethostbyname_r(const char *name, struct hostent *ret, char *buf,
+                size_t buflen, struct hostent **result, int *h_errnop)
+{
+    return sal_gethostbyname_r(name, ret, buf, buflen, result, h_errnop);
+}
+
+void freeaddrinfo(struct addrinfo *ai)
+{
+    sal_freeaddrinfo(ai);
+}
+RTM_EXPORT(freeaddrinfo);
+
+int getaddrinfo(const char *nodename,
+       const char *servname,
+       const struct addrinfo *hints,
+       struct addrinfo **res)
+{
+    return sal_getaddrinfo(nodename, servname, hints, res);
+}
+RTM_EXPORT(getaddrinfo);