/* Copyright (c) 2015, 2021, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   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, version 2.0, 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 St, Fifth Floor, Boston, MA 02110-1301  USA */

#if defined(linux) && !defined(_XOPEN_SOURCE)
#define _XOPEN_SOURCE
#endif

#if defined(linux) && !defined(_GNU_SOURCE)
#define _GNU_SOURCE
#endif

#include "x_platform.h"

#include <sys/types.h>

#ifndef WIN
#include <sys/socket.h>
#endif

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

#include "simset.h"
#include "task_debug.h"
#include "xcom_vp.h"
#include "task.h"
#include "task_os.h"

/**
 * Wrapper function which retries and checks errors from socket
 */
result	xcom_checked_socket(int domain, int type, int protocol)
{
	result	ret = {0,0};
	int	retry = 1000;
	do {
	  	SET_OS_ERR(0);
		ret.val = socket(domain, type, protocol);
		ret.funerr = to_errno(GET_OS_ERR);
	} while (--retry && ret.val == -1 && (from_errno(ret.funerr) == SOCK_EAGAIN));
	if (ret.val == -1) {
		task_dump_err(ret.funerr);
		/* abort(); */
	}
	return ret;
}


/**
 * Wrapper function which retries and checks errors from getaddrinfo
 */
int
checked_getaddrinfo(const char *nodename, const char *servname,
const struct addrinfo *hints, struct addrinfo **res)
{
	int	errval = 0;
	/** FIXME: Lookup IPv4 only for now */
	struct addrinfo _hints;
	memset(&_hints, 0, sizeof(_hints));
	_hints.ai_family = PF_INET;
	if (hints == NULL)
		hints = &_hints;
	do {
		if (*res) {
			freeaddrinfo(*res);
			*res = NULL;
		}
		errval = getaddrinfo(nodename, servname, hints, res);
	} while (errval == EAI_AGAIN);
#if defined(EAI_NODATA) && EAI_NODATA != EAI_NONAME
        /* Solaris may return EAI_NODATA as well as EAI_NONAME */
        if (errval && errval != EAI_NONAME && errval != EAI_NODATA) {
#else
        /* FreeBSD has removed the definition of EAI_NODATA altogether. */
        if (errval && errval != EAI_NONAME) {
#endif
#if !defined(WIN32) && !defined(WIN64)
		DBGOUT(NUMEXP(errval); STREXP(gai_strerror(errval));
		    if (errval == EAI_SYSTEM) {
			NUMEXP(errno); STREXP(g_strerror(errno));
		}
		);
#else
		DBGOUT(NUMEXP(errval); STREXP(gai_strerror(errval)));
#endif
	}
	assert((errval == 0 && *res) || (errval != 0 && *res == NULL));
	return errval;
}

struct infonode;
typedef struct infonode infonode;

struct infonode {
	char const *server;
	struct addrinfo *addr;
	infonode *left;
	infonode *right;
};

static infonode *addrinfomap;

static infonode *insert_server(infonode **top, char const *server, struct addrinfo *addr)
{
	if (!top)
		return 0;
	else {
		if (*top == 0) { /* Insert here */
			infonode * n = calloc(1, sizeof(infonode));
			n->server = strdup(server);
			n->addr = addr;
			*top = n;
			return n;
		} else {
			int	cmp = strcmp(server, (*top)->server);
			assert(cmp);
			if (cmp == 0) /* Already in map */
				return * top;
			/* Look in subtree */
			if (cmp < 0)
				return insert_server(&(*top)->left, server, addr);
			else
				return insert_server(&(*top)->right, server, addr);
		}
	}
}

static infonode *lookup_server(infonode *top, char const *server)
{
	if (!top)
		return 0;
	else {
		int	cmp = strcmp(server, top->server);
		if (cmp == 0)
			return top;
		/* Look in subtree */
		if (cmp < 0)
			return lookup_server(top->left, server);
		else
			return lookup_server(top->right, server);
	}
}


struct addrinfo *caching_getaddrinfo(char const *server)
{
	infonode * n = lookup_server(addrinfomap, server);

	if (n)
		return n->addr;
	else {
		struct addrinfo *addr = 0;
		checked_getaddrinfo(server, 0, 0, &addr);
		if (addr)
			insert_server(&addrinfomap, server, addr);
		return addr;
	}
}

void free_getaddrinfo_cache(infonode *top)
{
  if (top)
  {
    infonode* right= top->right;
    infonode* left= top->left;
    free((char *)top->server);
    freeaddrinfo(top->addr);
    free(top);
    if (right)
      free_getaddrinfo_cache(right);
    if (left)
      free_getaddrinfo_cache(left);
  }
}

#ifdef WIN

/* Need to link with Ws2_32.lib */
#pragma comment(lib, "ws2_32.lib")


int init_net()
{

	WORD wVersionRequested;
	WSADATA wsaData;
	int	err;

	/* Use the MAKEWORD(lowbyte, highbyte) macro declared in Windef.h */
	wVersionRequested = MAKEWORD(2, 2);

	err = WSAStartup(wVersionRequested, &wsaData);
	if (err != 0) {
		/* Tell the user that we could not find a usable */
		/* Winsock DLL. */
		g_critical("WSAStartup failed with error: %d", err);
		return 1;
	}

	/* Confirm that the WinSock DLL supports 2.2.*/
	/* Note that if the DLL supports versions greater    */
	/* than 2.2 in addition to 2.2, it will still return */
	/* 2.2 in wVersion since that is the version we      */
	/* requested.                                        */

	if (LOBYTE(wsaData.wVersion) != 2 || HIBYTE(wsaData.wVersion) != 2) {
		/* Tell the user that we could not find a usable */
		/* WinSock DLL.                                  */
		g_critical("Could not find a usable version of Winsock.dll");
		return 1;
	} else {
		G_DEBUG("The Winsock 2.2 dll was found okay");
		return 0;
	}
}

int deinit_net()
{
    WSACleanup();
    if (addrinfomap)
    {
      free_getaddrinfo_cache(addrinfomap);
      addrinfomap= NULL;
    }
    return 0;
}

#else
int init_net()
{
  return 0;
}

int deinit_net()
{
  if (addrinfomap)
  {
    free_getaddrinfo_cache(addrinfomap);
    addrinfomap= NULL;
  }
  return 0;
}

#endif
