/*
 * Copyright (c) 2021-2022 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * \file ip_address.h
 * \brief IP address type
 */
#ifndef UTIL_IP_ADDRESS_H
#define UTIL_IP_ADDRESS_H

#ifdef __APPLE__
#include <libkern/OSByteOrder.h>
#define __bswap_constant_32(x) OSSwapInt32 (x)
#include <machine/endian.h>
#else
#ifdef __ANDROID__
#include <byteswap.h>
#endif

#endif
#include <errno.h>

#include <assert.h>
#ifndef _WIN32
#include <netinet/in.h> // struct sockadd
#include <arpa/inet.h>	// inet_ntop
#include <netdb.h>	// struct addrinfo
#endif
#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h> // snprintf
#include <string.h> // memset

#include "types.h"

#define bytes_to_bits(x)    (x * 8)
#define IPV6_ADDR_LEN	    16 /* bytes */
#define IPV4_ADDR_LEN	    4  /* bytes */
#define IPV6_ADDR_LEN_BITS  bytes_to_bits (IPV6_ADDR_LEN)
#define IPV4_ADDR_LEN_BITS  bytes_to_bits (IPV4_ADDR_LEN)
#define MAX_IPV6_PREFIX_LEN 128

/* Presentation format */
#ifndef INET_ADDRSTRLEN
#define INET_ADDRSTRLEN 16
#endif

#ifndef INET6_ADDRSTRLEN
#define INET6_ADDRSTRLEN 46
#endif
//#define INET_MAX_ADDRSTRLEN INET6_ADDRSTRLEN

#define IP_ADDRESS_MAX_LEN IPV6_ADDR_LEN

#define DUMMY_PORT 1234

typedef union
{
  struct in_addr as_inaddr;
  u8 buffer[4];
  u8 as_u8[4];
  u16 as_u16[2];
  u32 as_u32;
} ipv4_address_t;

static_assert (sizeof (ipv4_address_t) == 4, "");

typedef union __attribute__ ((__packed__))
{
  struct in6_addr as_in6addr;
  u8 buffer[16];
  u8 as_u8[16];
  u16 as_u16[8];
  u32 as_u32[4];
  u64 as_u64[2];
} ipv6_address_t;

static_assert (sizeof (ipv6_address_t) == 16, "");

#ifdef HICN_VPP_PLUGIN
#include <vnet/ip/ip46_address.h>
static_assert (sizeof (ipv4_address_t) == sizeof (ip4_address_t), "");
static_assert (sizeof (ipv6_address_t) == sizeof (ip6_address_t), "");
#endif

typedef union
{
  struct
  {
    u32 pad[3];
    ipv4_address_t v4;
  };
  ipv6_address_t v6;
#if 0 /* removed as prone to error due to IPv4 padding */
    u8 buffer[IP_MAX_ADDR_LEN];
    u8 as_u8[IP_MAX_ADDR_LEN];
    u16 as_u16[IP_MAX_ADDR_LEN >> 1];
    u32 as_u32[IP_MAX_ADDR_LEN >> 2];
    u64 as_u64[IP_MAX_ADDR_LEN >> 3];
#endif
#ifdef HICN_VPP_PLUGIN
  ip46_address_t as_ip46;
#endif /* HICN_VPP_PLUGIN */
} hicn_ip_address_t;

static_assert (sizeof (hicn_ip_address_t) == 16, "");

#define hicn_ip_address_is_v4(ip)                                             \
  (((ip)->pad[0] | (ip)->pad[1] | (ip)->pad[2]) == 0)

#define MAXSZ_IP4_ADDRESS_ INET_ADDRSTRLEN - 1
#define MAXSZ_IP6_ADDRESS_ INET6_ADDRSTRLEN - 1
#define MAXSZ_IP_ADDRESS_  MAXSZ_IP6_ADDRESS_
#define MAXSZ_IP4_ADDRESS  MAXSZ_IP4_ADDRESS_ + 1
#define MAXSZ_IP6_ADDRESS  MAXSZ_IP6_ADDRESS_ + 1
#define MAXSZ_IP_ADDRESS   MAXSZ_IP_ADDRESS_ + 1

#define IP_ADDRESS_V4_OFFSET_LEN 12

typedef struct
{
  int family;
  hicn_ip_address_t address;
  u8 len;
} hicn_ip_prefix_t;

#define MAXSZ_IP_PREFIX_ MAXSZ_IP_ADDRESS_ + 1 + 3
#define MAXSZ_IP_PREFIX	 MAXSZ_IP_PREFIX_ + 1

extern const hicn_ip_address_t IPV4_LOOPBACK;
extern const hicn_ip_address_t IPV6_LOOPBACK;
extern const hicn_ip_address_t IPV4_ANY;
extern const hicn_ip_address_t IPV6_ANY;

extern const ipv4_address_t IP4_ADDRESS_EMPTY;
extern const ipv6_address_t IP6_ADDRESS_EMPTY;
extern const hicn_ip_address_t IP_ADDRESS_EMPTY;

#define IP_ANY(family) (family == AF_INET) ? IPV4_ANY : IPV6_ANY

#define MAX_PORT	 1 << (8 * sizeof (u16))
#define IS_VALID_PORT(x) ((x > 0) && ((int) x < MAX_PORT))

#define MAXSZ_PORT_ 5
#define MAXSZ_PORT  MAXSZ_PORT_ + 1

#define IS_VALID_FAMILY(x) ((x == AF_INET) || (x == AF_INET6))

/* IP address */
int hicn_ip_address_get_family (const hicn_ip_address_t *address);
int hicn_ip_address_str_get_family (const char *ip_address);
int hicn_ip_address_len (int family);
int hicn_ip_address_get_len (const hicn_ip_address_t *ip_address);

int hicn_ip_address_get_len_bits (const hicn_ip_address_t *ip_address);
const u8 *hicn_ip_address_get_buffer (const hicn_ip_address_t *ip_address,
				      int family);
int hicn_ip_address_ntop (const hicn_ip_address_t *ip_address, char *dst,
			  const size_t len, int family);
int hicn_ip_address_pton (const char *ip_address_str,
			  hicn_ip_address_t *ip_address);
int hicn_ip_address_snprintf (char *s, size_t size,
			      const hicn_ip_address_t *ip_address);
int hicn_ip_address_to_sockaddr (const hicn_ip_address_t *ip_address,
				 struct sockaddr *sa, int family);
int hicn_ip_address_cmp (const hicn_ip_address_t *ip1,
			 const hicn_ip_address_t *ip2);
bool hicn_ip_address_equals (const hicn_ip_address_t *ip1,
			     const hicn_ip_address_t *ip2);
int hicn_ip_address_empty (const hicn_ip_address_t *ip);

uint8_t hicn_ip_address_get_bit (const hicn_ip_address_t *address,
				 uint8_t pos);

bool hicn_ip_address_match_family (const hicn_ip_address_t *address,
				   int family);

uint32_t hicn_ip_address_get_hash (const hicn_ip_address_t *address);

void hicn_ip_address_clear (hicn_ip_address_t *address);

/* Prefix */

int hicn_ip_prefix_pton (const char *ip_address_str,
			 hicn_ip_prefix_t *hicn_ip_prefix);
int hicn_ip_prefix_ntop_short (const hicn_ip_prefix_t *hicn_ip_prefix,
			       char *dst, size_t size);
int hicn_ip_prefix_ntop (const hicn_ip_prefix_t *hicn_ip_prefix, char *dst,
			 size_t size);
int hicn_ip_prefix_snprintf (char *s, size_t size,
			     const hicn_ip_prefix_t *prefix);
int hicn_ip_prefix_len (const hicn_ip_prefix_t *prefix);
bool hicn_ip_prefix_empty (const hicn_ip_prefix_t *prefix);
int hicn_ip_prefix_to_sockaddr (const hicn_ip_prefix_t *prefix,
				struct sockaddr *sa);
int hicn_ip_prefix_cmp (const hicn_ip_prefix_t *prefix1,
			const hicn_ip_prefix_t *prefix2);

/* URL */

#define MAXSZ_PROTO_ 8 /* inetX:// */
#define MAXSZ_PROTO  MAXSZ_PROTO_ + NULLTERM

#define MAXSZ_URL4_ MAXSZ_PROTO_ + MAXSZ_IP4_ADDRESS_ + MAXSZ_PORT_
#define MAXSZ_URL6_ MAXSZ_PROTO_ + MAXSZ_IP6_ADDRESS_ + MAXSZ_PORT_
#define MAXSZ_URL_  MAXSZ_URL6_
#define MAXSZ_URL4  MAXSZ_URL4_ + NULLTERM
#define MAXSZ_URL6  MAXSZ_URL6_ + NULLTERM
#define MAXSZ_URL   MAXSZ_URL_ + NULLTERM

int url_snprintf (char *s, size_t size, const hicn_ip_address_t *ip_address,
		  u16 port);

#endif /* UTIL_IP_ADDRESS_H */