bird/lib/ip.h
Ondrej Zajicek (work) 13225f1dbf Filter: Faster prefix sets
Use 16-way (4bit) branching in prefix trie instead of basic binary
branching. The change makes IPv4 prefix sets almost 3x faster, but
with more memory consumption and much more complicated algorithm.

Together with a previous filter change, it makes IPv4 prefix sets
about ~4.3x faster and slightly smaller (on my test data).
2021-09-25 16:06:43 +02:00

428 lines
11 KiB
C

/*
* 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
#define MPLS_NULL 3
/* IANA Address Family Numbers */
/* https://www.iana.org/assignments/address-family-numbers/address-family-numbers.xhtml */
/* Would use AF_ prefix, but that collides with POSIX address family numbers */
#define AFI_IPV4 1
#define AFI_IPV6 2
#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) ((u32) (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)
{ return u32_hash(_I(a)); }
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)
static inline int ip4_is_unicast(ip4_addr a)
{ return _I(a) < 0xe0000000; }
/* 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) >> (31 - pos)) & 1; }
static inline u32 ip4_getbits(ip4_addr a, uint pos, uint n)
{ return (_I(a) >> ((32 - n) - pos)) & ((1u << n) - 1); }
static inline u32 ip6_getbit(ip6_addr a, uint pos)
{ return (a.addr[pos / 32] >> (31 - (pos % 32))) & 0x1; }
static inline u32 ip6_getbits(ip6_addr a, uint pos, uint n)
{ return (a.addr[pos / 32] >> ((32 - n) - (pos % 32))) & ((1u << n) - 1); }
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_setbits(ip4_addr a, uint pos, uint val)
{ _I(a) |= val << (31 - pos); return a; }
static inline ip6_addr ip6_setbits(ip6_addr a, uint pos, uint val)
{ a.addr[pos / 32] |= val << (31 - pos % 32); return a; }
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
typedef struct mpls_label_stack {
uint len;
u32 stack[MPLS_MAX_LABEL_STACK];
} mpls_label_stack;
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(const void *buf)
{
return _MI4(get_u32(buf));
}
static inline ip6_addr get_ip6(const 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