Internet on FIRE

/*

 *        BIRD Internet Routing Daemon -- The Internet Protocol

 *

 *        (c) 1998 Martin Mares <mj@ucw.cz>

 *

 *        Can be freely distributed and used under the terms of the GNU GPL.

 */

#ifndef _BIRD_IP_H_

#define _BIRD_IP_H_

#include "sysdep/unix/endian.h"

#include "lib/string.h"

#include "lib/bitops.h"

#include "lib/unaligned.h"

#define IP4_ALL_NODES                ipa_build4(224, 0, 0, 1)

#define IP4_ALL_ROUTERS                ipa_build4(224, 0, 0, 2)

#define IP4_OSPF_ALL_ROUTERS        ipa_build4(224, 0, 0, 5)

#define IP4_OSPF_DES_ROUTERS        ipa_build4(224, 0, 0, 6)

#define IP4_RIP_ROUTERS                ipa_build4(224, 0, 0, 9)

#define IP6_ALL_NODES                ipa_build6(0xFF020000, 0, 0, 1)

#define IP6_ALL_ROUTERS                ipa_build6(0xFF020000, 0, 0, 2)

#define IP6_OSPF_ALL_ROUTERS        ipa_build6(0xFF020000, 0, 0, 5)

#define IP6_OSPF_DES_ROUTERS        ipa_build6(0xFF020000, 0, 0, 6)

#define IP6_RIP_ROUTERS                ipa_build6(0xFF020000, 0, 0, 9)

#define IP6_BABEL_ROUTERS        ipa_build6(0xFF020000, 0, 0, 0x00010006)

#define IP4_NONE                _MI4(0)

#define IP6_NONE                _MI6(0,0,0,0)

#define IP4_MAX_PREFIX_LENGTH        32

#define IP6_MAX_PREFIX_LENGTH        128

#define IP4_MAX_TEXT_LENGTH        15        /* "255.255.255.255" */

#define IP6_MAX_TEXT_LENGTH        39        /* "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff" */

#define IPA_MAX_TEXT_LENGTH        39

#define IP4_MIN_MTU                576

#define IP6_MIN_MTU                1280

#define IP_PREC_INTERNET_CONTROL 0xc0

#define IP4_HEADER_LENGTH        20

#define IP6_HEADER_LENGTH        40

#define UDP_HEADER_LENGTH        8

#ifdef DEBUGGING

typedef struct ip4_addr {

  u32 addr;

} ip4_addr;

#define _MI4(x) ((struct ip4_addr) { x })

#define _I(x) (x).addr

#else

typedef u32 ip4_addr;

#define _MI4(x) (x)

#define _I(x) (x)

#endif

typedef struct ip6_addr {

  u32 addr[4];

} ip6_addr;

#define _MI6(a,b,c,d) ((struct ip6_addr) {{ a, b, c, d }})

#define _I0(a) ((a).addr[0])

#define _I1(a) ((a).addr[1])

#define _I2(a) ((a).addr[2])

#define _I3(a) ((a).addr[3])

/* Structure ip_addr may contain both IPv4 and IPv6 addresses */

typedef ip6_addr ip_addr;

#define IPA_NONE IP6_NONE

#define ipa_from_ip4(x) _MI6(0,0,0xffff,_I(x))

#define ipa_from_ip6(x) x

#define ipa_from_u32(x) ipa_from_ip4(ip4_from_u32(x))

#define ipa_to_ip4(x) _MI4(_I3(x))

#define ipa_to_ip6(x) x

#define ipa_to_u32(x) ip4_to_u32(ipa_to_ip4(x))

#define ipa_is_ip4(a) ip6_is_v4mapped(a)

#define ipa_is_ip6(a) (! ip6_is_v4mapped(a))

#define IPA_NONE4 ipa_from_ip4(IP4_NONE)

#define IPA_NONE6 ipa_from_ip6(IP6_NONE)

/*

 *        Public constructors

 */

#define ip4_from_u32(x) _MI4(x)

#define ip4_to_u32(x) _I(x)

#define ip4_build(a,b,c,d) _MI4(((a) << 24) | ((b) << 16) | ((c) << 8) | (d))

#define ip6_build(a,b,c,d) _MI6(a,b,c,d)

#define ipa_build4(a,b,c,d) ipa_from_ip4(ip4_build(a,b,c,d))

#define ipa_build6(a,b,c,d) ipa_from_ip6(ip6_build(a,b,c,d))

/*

 *        Basic algebraic functions

 */

static inline int ip4_equal(ip4_addr a, ip4_addr b)

{ return _I(a) == _I(b); }

static inline int ip4_zero(ip4_addr a)

{ return _I(a) == 0; }

static inline int ip4_nonzero(ip4_addr a)

{ return _I(a) != 0; }

static inline ip4_addr ip4_and(ip4_addr a, ip4_addr b)

{ return _MI4(_I(a) & _I(b)); }

static inline ip4_addr ip4_or(ip4_addr a, ip4_addr b)

{ return _MI4(_I(a) | _I(b)); }

static inline ip4_addr ip4_xor(ip4_addr a, ip4_addr b)

{ return _MI4(_I(a) ^ _I(b)); }

static inline ip4_addr ip4_not(ip4_addr a)

{ return _MI4(~_I(a)); }

static inline int ip6_equal(ip6_addr a, ip6_addr b)

{ return _I0(a) == _I0(b) && _I1(a) == _I1(b) && _I2(a) == _I2(b) && _I3(a) == _I3(b); }

static inline int ip6_zero(ip6_addr a)

{ return  !_I0(a) && !_I1(a) && !_I2(a) && !_I3(a); }

static inline int ip6_nonzero(ip6_addr a)

{ return _I0(a) || _I1(a) || _I2(a) || _I3(a); }

static inline ip6_addr ip6_and(ip6_addr a, ip6_addr b)

{ return _MI6(_I0(a) & _I0(b), _I1(a) & _I1(b), _I2(a) & _I2(b), _I3(a) & _I3(b)); }

static inline ip6_addr ip6_or(ip6_addr a, ip6_addr b)

{ return _MI6(_I0(a) | _I0(b), _I1(a) | _I1(b), _I2(a) | _I2(b), _I3(a) | _I3(b)); }

static inline ip6_addr ip6_xor(ip6_addr a, ip6_addr b)

{ return _MI6(_I0(a) ^ _I0(b), _I1(a) ^ _I1(b), _I2(a) ^ _I2(b), _I3(a) ^ _I3(b)); }

static inline ip6_addr ip6_not(ip6_addr a)

{ return _MI6(~_I0(a), ~_I1(a), ~_I2(a), ~_I3(a)); }

#define ipa_equal(x,y) ip6_equal(x,y)

#define ipa_zero(x) ip6_zero(x)

#define ipa_nonzero(x) ip6_nonzero(x)

#define ipa_and(x,y) ip6_and(x,y)

#define ipa_or(x,y) ip6_or(x,y)

#define ipa_xor(x,y) ip6_xor(x,y)

#define ipa_not(x) ip6_not(x)

/*

 * A zero address is either a token for invalid/unused, or the prefix of default

 * routes. These functions should be used in the second case, where both IPv4

 * and IPv6 zero addresses should be checked.

 */

static inline int ipa_zero2(ip_addr a)

{ return  !_I0(a) && !_I1(a) && ((_I2(a) == 0) || (_I2(a) == 0xffff)) && !_I3(a); }

static inline int ipa_nonzero2(ip_addr a)

{ return _I0(a) || _I1(a) || ((_I2(a) != 0) && (_I2(a) != 0xffff)) || _I3(a); }

/*

 *        Hash and compare functions

 */

static inline u32 ip4_hash(ip4_addr a)

{

  /* Returns a 32-bit value, although low-order bits are not mixed */

  u32 x = _I(a);

  x ^= x << 16;

  x ^= x << 12;

  return x;

}

static inline u32 ip6_hash(ip6_addr a)

{

  /* Returns a 32-bit hash key, although low-order bits are not mixed */

  u32 x = _I0(a) ^ _I1(a) ^ _I2(a) ^ _I3(a);

  return x ^ (x << 16) ^ (x << 24);

}

static inline int ip4_compare(ip4_addr a, ip4_addr b)

{ return (_I(a) > _I(b)) - (_I(a) < _I(b)); }

int ip6_compare(ip6_addr a, ip6_addr b);

#define ipa_hash(x) ip6_hash(x)

#define ipa_compare(x,y) ip6_compare(x,y)

/*

 *        IP address classification

 */

/* Address class */

#define IADDR_INVALID                -1

#define IADDR_SCOPE_MASK               0xfff

#define IADDR_HOST                0x1000

#define IADDR_BROADCAST                0x2000

#define IADDR_MULTICAST                0x4000

/* Address scope */

#define SCOPE_HOST                0

#define SCOPE_LINK                1

#define SCOPE_SITE                2

#define SCOPE_ORGANIZATION        3

#define SCOPE_UNIVERSE                4

#define SCOPE_UNDEFINED                5

int ip4_classify(ip4_addr ad);

int ip6_classify(ip6_addr *a);

static inline int ip6_is_link_local(ip6_addr a)

{ return (_I0(a) & 0xffc00000) == 0xfe800000; }

static inline int ip6_is_v4mapped(ip6_addr a)

{ return _I0(a) == 0 && _I1(a) == 0 && _I2(a) == 0xffff; }

#define ipa_classify(x) ip6_classify(&(x))

#define ipa_is_link_local(x) ip6_is_link_local(x)

/* XXXX remove */

static inline int ipa_classify_net(ip_addr a)

{ return ipa_zero2(a) ? (IADDR_HOST | SCOPE_UNIVERSE) : ipa_classify(a); }

/*

 *        Miscellaneous IP prefix manipulation

 */

static inline ip4_addr ip4_mkmask(uint n)

{ return _MI4(u32_mkmask(n)); }

static inline uint ip4_masklen(ip4_addr a)

{ return u32_masklen(_I(a)); }

ip6_addr ip6_mkmask(uint n);

uint ip6_masklen(ip6_addr *a);

/* ipX_pxlen() requires that x != y */

static inline uint ip4_pxlen(ip4_addr a, ip4_addr b)

{ return 31 - u32_log2(_I(a) ^ _I(b)); }

static inline uint ip6_pxlen(ip6_addr a, ip6_addr b)

{

  int i = 0;

  i += (a.addr[i] == b.addr[i]);

  i += (a.addr[i] == b.addr[i]);

  i += (a.addr[i] == b.addr[i]);

  i += (a.addr[i] == b.addr[i]);

  return 32 * i + 31 - u32_log2(a.addr[i] ^ b.addr[i]);

}

static inline u32 ip4_getbit(ip4_addr a, uint pos)

{ return _I(a) & (0x80000000 >> pos); }

static inline u32 ip6_getbit(ip6_addr a, uint pos)

{ return a.addr[pos / 32] & (0x80000000 >> (pos % 32)); }

static inline u32 ip4_setbit(ip4_addr *a, uint pos)

{ return _I(*a) |= (0x80000000 >> pos); }

static inline u32 ip6_setbit(ip6_addr *a, uint pos)

{ return a->addr[pos / 32] |= (0x80000000 >> (pos % 32)); }

static inline u32 ip4_clrbit(ip4_addr *a, uint pos)

{ return _I(*a) &= ~(0x80000000 >> pos); }

static inline u32 ip6_clrbit(ip6_addr *a, uint pos)

{ return a->addr[pos / 32] &= ~(0x80000000 >> (pos % 32)); }

static inline ip4_addr ip4_opposite_m1(ip4_addr a)

{ return _MI4(_I(a) ^ 1); }

static inline ip4_addr ip4_opposite_m2(ip4_addr a)

{ return _MI4(_I(a) ^ 3); }

static inline ip6_addr ip6_opposite_m1(ip6_addr a)

{ return _MI6(_I0(a), _I1(a), _I2(a), _I3(a) ^ 1); }

static inline ip6_addr ip6_opposite_m2(ip6_addr a)

{ return _MI6(_I0(a), _I1(a), _I2(a), _I3(a) ^ 3); }

ip4_addr ip4_class_mask(ip4_addr ad);

#define ipa_opposite_m1(x) ip6_opposite_m1(x)

#define ipa_opposite_m2(x) ip6_opposite_m2(x)

/*

 *        Host/network order conversions

 */

static inline ip4_addr ip4_hton(ip4_addr a)

{ return _MI4(htonl(_I(a))); }

static inline ip4_addr ip4_ntoh(ip4_addr a)

{ return _MI4(ntohl(_I(a))); }

static inline ip6_addr ip6_hton(ip6_addr a)

{ return _MI6(htonl(_I0(a)), htonl(_I1(a)), htonl(_I2(a)), htonl(_I3(a))); }

static inline ip6_addr ip6_ntoh(ip6_addr a)

{ return _MI6(ntohl(_I0(a)), ntohl(_I1(a)), ntohl(_I2(a)), ntohl(_I3(a))); }

#define MPLS_MAX_LABEL_STACK 8

static inline int

mpls_get(const char *buf, int buflen, u32 *stack)

{

  for (int i=0; (i<MPLS_MAX_LABEL_STACK) && (i*4+3 < buflen); i++)

  {

    u32 s = get_u32(buf + i*4);

    stack[i] = s >> 12;

    if (s & 0x100)

      return i+1;

  }

  return -1;

}

static inline int

mpls_put(char *buf, int len, u32 *stack)

{

  for (int i=0; i<len; i++)

    put_u32(buf + i*4, stack[i] << 12 | (i+1 == len ? 0x100 : 0));

  return len*4;

}

/*

 *        Unaligned data access (in network order)

 */

static inline ip4_addr get_ip4(void *buf)

{

  return _MI4(get_u32(buf));

}

static inline ip6_addr get_ip6(void *buf)

{

  ip6_addr a;

  memcpy(&a, buf, 16);

  return ip6_ntoh(a);

}

static inline void * put_ip4(void *buf, ip4_addr a)

{

  put_u32(buf, _I(a));

  return buf+4;

}

static inline void * put_ip6(void *buf, ip6_addr a)

{

  a = ip6_hton(a);

  memcpy(buf, &a, 16);

  return buf+16;

}

/*

 *        Binary/text form conversions

 */

char *ip4_ntop(ip4_addr a, char *b);

char *ip6_ntop(ip6_addr a, char *b);

static inline char * ip4_ntox(ip4_addr a, char *b)

{ return b + bsprintf(b, "%08x", _I(a)); }

static inline char * ip6_ntox(ip6_addr a, char *b)

{ return b + bsprintf(b, "%08x.%08x.%08x.%08x", _I0(a), _I1(a), _I2(a), _I3(a)); }

int ip4_pton(const char *a, ip4_addr *o);

int ip6_pton(const char *a, ip6_addr *o);

/*

 *        Miscellaneous

 */

char *ip_scope_text(uint);

#endif