/*
  *  OpenVPN -- An application to securely tunnel IP networks
  *             over a single TCP/UDP port, with support for SSL/TLS-based
  *             session authentication and key exchange,
  *             packet encryption, packet authentication, and
  *             packet compression.
  *

  *  Copyright (C) 2002-2017 OpenVPN Technologies, Inc. <sales@openvpn.net>

  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2
  *  as published by the Free Software Foundation.
  *
  *  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.

  */
 
 #ifndef MROUTE_H
 #define MROUTE_H
 
 #if P2MP_SERVER
 
 #include "buffer.h"
 #include "list.h"
 #include "route.h"
 

 #include <stddef.h>
 

 #define IP_MCAST_SUBNET_MASK  ((in_addr_t)240<<24)
 #define IP_MCAST_NETWORK      ((in_addr_t)224<<24)
 
 /* Return status values for mroute_extract_addr_from_packet */

 
 #define MROUTE_EXTRACT_SUCCEEDED (1<<0)
 #define MROUTE_EXTRACT_BCAST     (1<<1)
 #define MROUTE_EXTRACT_MCAST     (1<<2)
 #define MROUTE_EXTRACT_IGMP      (1<<3)
 
 #define MROUTE_SEC_EXTRACT_SUCCEEDED (1<<(0+MROUTE_SEC_SHIFT))
 #define MROUTE_SEC_EXTRACT_BCAST     (1<<(1+MROUTE_SEC_SHIFT))
 #define MROUTE_SEC_EXTRACT_MCAST     (1<<(2+MROUTE_SEC_SHIFT))
 #define MROUTE_SEC_EXTRACT_IGMP      (1<<(3+MROUTE_SEC_SHIFT))
 
 #define MROUTE_SEC_SHIFT         4

 
 /*
  * Choose the largest address possible with
  * any of our supported types, which is IPv6
  * with port number.
  */
 #define MR_MAX_ADDR_LEN 20
 
 /*
  * Address Types
  */
 #define MR_ADDR_NONE             0
 #define MR_ADDR_ETHER            1
 #define MR_ADDR_IPV4             2
 #define MR_ADDR_IPV6             3
 #define MR_ADDR_MASK             3
 
 /* Address type mask indicating that port # is part of address */
 #define MR_WITH_PORT             4
 
 /* Address type mask indicating that netbits is part of address */
 #define MR_WITH_NETBITS          8
 

 /* Indicates than IPv4 addr was extracted from ARP packet */
 #define MR_ARP                   16
 

 struct mroute_addr {

     uint8_t len;    /* length of address */
     uint8_t unused;
     uint8_t type;   /* MR_ADDR/MR_WITH flags */
     uint8_t netbits; /* number of bits in network part of address,
                       * valid if MR_WITH_NETBITS is set */
     union {
         uint8_t raw_addr[MR_MAX_ADDR_LEN]; /* actual address */
         uint8_t eth_addr[OPENVPN_ETH_ALEN];
         struct {
             in_addr_t addr;     /* _network order_ IPv4 address */
             in_port_t port;     /* _network order_ TCP/UDP port */
         } v4;
         struct {
             struct in6_addr addr;
             in_port_t port;     /* _network order_ TCP/UDP port */
         } v6;
         struct {
             uint8_t prefix[12];
             in_addr_t addr;     /* _network order_ IPv4 address */
         } v4mappedv6;
     }

 #ifndef HAVE_ANONYMOUS_UNION_SUPPORT
 /* Wrappers to support compilers that do not grok anonymous unions */

         mroute_union

 #define raw_addr mroute_union.raw_addr
 #define eth_addr mroute_union.eth_addr
 #define v4 mroute_union.v4
 #define v6 mroute_union.v6
 #define v4mappedv6 mroute_union.v4mappedv6
 #endif

     ;

 };
 

 /* Double-check that struct packing works as expected */

 static_assert(offsetof(struct mroute_addr, v4.port) ==
               offsetof(struct mroute_addr, v4) + 4,
               "Unexpected struct packing of v4");
 static_assert(offsetof(struct mroute_addr, v6.port) ==
               offsetof(struct mroute_addr, v6) + 16,
               "Unexpected struct packing of v6");
 static_assert(offsetof(struct mroute_addr, v4mappedv6.addr) ==
               offsetof(struct mroute_addr, v4mappedv6) + 12,
               "Unexpected struct packing of v4mappedv6");

 /*

  * Number of bits in an address.  Should be raised for IPv6.

  */

 #define MR_HELPER_NET_LEN 129

 
 /*
  * Used to help maintain CIDR routing table.
  */
 struct mroute_helper {

     unsigned int cache_generation; /* incremented when route added */
     int ageable_ttl_secs;        /* host route cache entry time-to-live*/
     int n_net_len;               /* length of net_len array */
     uint8_t net_len[MR_HELPER_NET_LEN];    /* CIDR netlengths in descending order */
     int net_len_refcount[MR_HELPER_NET_LEN]; /* refcount of each netlength */

 };
 

 struct openvpn_sockaddr;
 

 bool mroute_extract_openvpn_sockaddr(struct mroute_addr *addr,
                                      const struct openvpn_sockaddr *osaddr,
                                      bool use_port);

 bool mroute_learnable_address(const struct mroute_addr *addr,
                               struct gc_arena *gc);

 uint32_t mroute_addr_hash_function(const void *key, uint32_t iv);

 bool mroute_addr_compare_function(const void *key1, const void *key2);

 void mroute_addr_init(struct mroute_addr *addr);
 
 const char *mroute_addr_print(const struct mroute_addr *ma,
                               struct gc_arena *gc);

 #define MAPF_SUBNET            (1<<0)
 #define MAPF_IA_EMPTY_IF_UNDEF (1<<1)
 #define MAPF_SHOW_ARP          (1<<2)

 const char *mroute_addr_print_ex(const struct mroute_addr *ma,
                                  const unsigned int flags,
                                  struct gc_arena *gc);
 
 void mroute_addr_mask_host_bits(struct mroute_addr *ma);
 
 struct mroute_helper *mroute_helper_init(int ageable_ttl_secs);
 
 void mroute_helper_free(struct mroute_helper *mh);

 void mroute_helper_add_iroute46(struct mroute_helper *mh, int netbits);

 void mroute_helper_del_iroute46(struct mroute_helper *mh, int netbits);

 /*
  * Given a raw packet in buf, return the src and dest
  * addresses of the packet.
  */
 static inline unsigned int

 mroute_extract_addr_from_packet(struct mroute_addr *src,
                                 struct mroute_addr *dest,
                                 struct mroute_addr *esrc,
                                 struct mroute_addr *edest,
                                 const struct buffer *buf,
                                 int tunnel_type)

 {

     unsigned int mroute_extract_addr_ip(struct mroute_addr *src,
                                      struct mroute_addr *dest,
                                      const struct buffer *buf);

 
     unsigned int mroute_extract_addr_ether(struct mroute_addr *src,
                                            struct mroute_addr *dest,
                                            struct mroute_addr *esrc,
                                            struct mroute_addr *edest,
                                            const struct buffer *buf);
 
     unsigned int ret = 0;
     verify_align_4(buf);
     if (tunnel_type == DEV_TYPE_TUN)
     {

         ret = mroute_extract_addr_ip(src, dest, buf);

     }
     else if (tunnel_type == DEV_TYPE_TAP)
     {
         ret = mroute_extract_addr_ether(src, dest, esrc, edest, buf);
     }
     return ret;

 }
 

 static inline bool

 mroute_addr_equal(const struct mroute_addr *a1, const struct mroute_addr *a2)

 {

     if (a1->type != a2->type)
     {
         return false;
     }
     if (a1->netbits != a2->netbits)
     {
         return false;
     }
     if (a1->len != a2->len)
     {
         return false;
     }
     return memcmp(a1->raw_addr, a2->raw_addr, a1->len) == 0;

 }
 
 static inline const uint8_t *

 mroute_addr_hash_ptr(const struct mroute_addr *a)

 {

     /* NOTE: depends on ordering of struct mroute_addr */
     return (uint8_t *) &a->type;

 }
 
 static inline uint32_t

 mroute_addr_hash_len(const struct mroute_addr *a)

 {

     return (uint32_t) a->len + 2;

 }
 
 static inline void

 mroute_extract_in_addr_t(struct mroute_addr *dest, const in_addr_t src)

 {

     dest->type = MR_ADDR_IPV4;
     dest->netbits = 0;
     dest->len = 4;
     dest->v4.addr = htonl(src);

 }
 

 static inline in_addr_t

 in_addr_t_from_mroute_addr(const struct mroute_addr *addr)

 {

     if ((addr->type & MR_ADDR_MASK) == MR_ADDR_IPV4 && addr->netbits == 0 && addr->len == 4)
     {
         return ntohl(addr->v4.addr);
     }
     else
     {
         return 0;
     }

 }
 

 static inline void

 mroute_addr_reset(struct mroute_addr *ma)

 {

     ma->len = 0;
     ma->type = MR_ADDR_NONE;

 }
 

 #endif /* P2MP_SERVER */
 #endif /* MROUTE_H */