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bird/nest/attrs.h
Ondrej Zajicek (work) ec430a7fee Nest: Implement BGP path mask loop operator 
Implement regex-like '+' operator in BGP path masks to match previous
path mask item multiple times. This is useful as ASNs may appear
multiple times in paths due to path prepending for traffic engineering
purposes.
2020-05-18 16:25:08 +02:00

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/*
* BIRD Internet Routing Daemon -- Attribute Operations
*
* (c) 2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#ifndef _BIRD_ATTRS_H_
#define _BIRD_ATTRS_H_
#include <stdint.h>
#include "lib/unaligned.h"
#include "nest/route.h"
/* a-path.c */
#define AS_PATH_SET 1 /* Types of path segments */
#define AS_PATH_SEQUENCE 2
#define AS_PATH_CONFED_SEQUENCE 3
#define AS_PATH_CONFED_SET 4
#define AS_PATH_MAXLEN 10000
#define AS_TRANS 23456
/* AS_TRANS is used when we need to store 32bit ASN larger than 0xFFFF
* to 16bit slot (like in 16bit AS_PATH). See RFC 4893 for details
*/
struct f_tree;
int as_path_valid(byte *data, uint len, int bs, int sets, int confed, char *err, uint elen);
int as_path_16to32(byte *dst, const byte *src, uint len);
int as_path_32to16(byte *dst, const byte *src, uint len);
int as_path_contains_as4(const struct adata *path);
int as_path_contains_confed(const struct adata *path);
struct adata *as_path_strip_confed(struct linpool *pool, const struct adata *op);
struct adata *as_path_prepend2(struct linpool *pool, const struct adata *op, int seq, u32 as);
struct adata *as_path_to_old(struct linpool *pool, const struct adata *path);
struct adata *as_path_cut(struct linpool *pool, const struct adata *path, uint num);
const struct adata *as_path_merge(struct linpool *pool, const struct adata *p1, const struct adata *p2);
void as_path_format(const struct adata *path, byte *buf, uint size);
int as_path_getlen(const struct adata *path);
int as_path_getlen_int(const struct adata *path, int bs);
int as_path_get_first(const struct adata *path, u32 *orig_as);
int as_path_get_first_regular(const struct adata *path, u32 *last_as);
int as_path_get_last(const struct adata *path, u32 *last_as);
u32 as_path_get_last_nonaggregated(const struct adata *path);
int as_path_contains(const struct adata *path, u32 as, int min);
int as_path_match_set(const struct adata *path, const struct f_tree *set);
const struct adata *as_path_filter(struct linpool *pool, const struct adata *path, const struct f_tree *set, u32 key, int pos);
static inline struct adata *as_path_prepend(struct linpool *pool, const struct adata *path, u32 as)
{ return as_path_prepend2(pool, path, AS_PATH_SEQUENCE, as); }
#define PM_ASN 0
#define PM_QUESTION 1
#define PM_ASTERISK 2
#define PM_ASN_EXPR 3
#define PM_ASN_RANGE 4
#define PM_ASN_SET 5
#define PM_LOOP 6
struct f_path_mask_item {
union {
u32 asn; /* PM_ASN */
const struct f_line *expr; /* PM_ASN_EXPR */
const struct f_tree *set; /* PM_ASN_SET */
struct { /* PM_ASN_RANGE */
u32 from;
u32 to;
};
};
int kind;
};
struct f_path_mask {
uint len;
struct f_path_mask_item item[0];
};
int as_path_match(const struct adata *path, const struct f_path_mask *mask);
/* Counterparts to appropriate as_path_* functions */
static inline int
aggregator_16to32(byte *dst, const byte *src)
{
put_u32(dst, get_u16(src));
memcpy(dst+4, src+2, 4);
return 8;
}
static inline int
aggregator_32to16(byte *dst, const byte *src)
{
put_u16(dst, get_u32(src));
memcpy(dst+2, src+4, 4);
return 6;
}
static inline int
aggregator_contains_as4(const struct adata *a)
{
return get_u32(a->data) > 0xFFFF;
}
static inline struct adata *
aggregator_to_old(struct linpool *pool, const struct adata *a)
{
struct adata *d = lp_alloc_adata(pool, 8);
put_u32(d->data, AS_TRANS);
memcpy(d->data + 4, a->data + 4, 4);
return d;
}
/* a-set.c */
/* Extended Community subtypes (kinds) */
enum ec_subtype {
EC_RT = 0x0002,
EC_RO = 0x0003,
EC_GENERIC = 0xFFFF,
};
static inline const char *ec_subtype_str(const enum ec_subtype ecs) {
switch (ecs) {
case EC_RT: return "rt";
case EC_RO: return "ro";
default: return NULL;
}
}
/* Transitive bit (for first u32 half of EC) */
#define EC_TBIT 0x40000000
#define ECOMM_LENGTH 8
static inline int int_set_get_size(const struct adata *list)
{ return list->length / 4; }
static inline int ec_set_get_size(const struct adata *list)
{ return list->length / 8; }
static inline int lc_set_get_size(const struct adata *list)
{ return list->length / 12; }
static inline u32 *int_set_get_data(const struct adata *list)
{ return (u32 *) list->data; }
static inline u32 ec_hi(u64 ec) { return ec >> 32; }
static inline u32 ec_lo(u64 ec) { return ec; }
static inline u64 ec_get(const u32 *l, int i)
{ return (((u64) l[i]) << 32) | l[i+1]; }
/* RFC 4360 3.1. Two-Octet AS Specific Extended Community */
static inline u64 ec_as2(enum ec_subtype kind, u64 key, u64 val)
{ return (((u64) kind | 0x0000) << 48) | (key << 32) | val; }
/* RFC 5668 4-Octet AS Specific BGP Extended Community */
static inline u64 ec_as4(enum ec_subtype kind, u64 key, u64 val)
{ return (((u64) kind | 0x0200) << 48) | (key << 16) | val; }
/* RFC 4360 3.2. IPv4 Address Specific Extended Community */
static inline u64 ec_ip4(enum ec_subtype kind, u64 key, u64 val)
{ return (((u64) kind | 0x0100) << 48) | (key << 16) | val; }
static inline u64 ec_generic(u64 key, u64 val)
{ return (key << 32) | val; }
/* Large community value */
typedef struct lcomm {
u32 asn;
u32 ldp1;
u32 ldp2;
} lcomm;
#define LCOMM_LENGTH 12
static inline lcomm lc_get(const u32 *l, int i)
{ return (lcomm) { l[i], l[i+1], l[i+2] }; }
static inline void lc_put(u32 *l, lcomm v)
{ l[0] = v.asn; l[1] = v.ldp1; l[2] = v.ldp2; }
static inline int lc_match(const u32 *l, int i, lcomm v)
{ return (l[i] == v.asn && l[i+1] == v.ldp1 && l[i+2] == v.ldp2); }
static inline u32 *lc_copy(u32 *dst, const u32 *src)
{ memcpy(dst, src, LCOMM_LENGTH); return dst + 3; }
int int_set_format(const struct adata *set, int way, int from, byte *buf, uint size);
int ec_format(byte *buf, u64 ec);
int ec_set_format(const struct adata *set, int from, byte *buf, uint size);
int lc_format(byte *buf, lcomm lc);
int lc_set_format(const struct adata *set, int from, byte *buf, uint size);
int int_set_contains(const struct adata *list, u32 val);
int ec_set_contains(const struct adata *list, u64 val);
int lc_set_contains(const struct adata *list, lcomm val);
const struct adata *int_set_prepend(struct linpool *pool, const struct adata *list, u32 val);
const struct adata *int_set_add(struct linpool *pool, const struct adata *list, u32 val);
const struct adata *ec_set_add(struct linpool *pool, const struct adata *list, u64 val);
const struct adata *lc_set_add(struct linpool *pool, const struct adata *list, lcomm val);
const struct adata *int_set_del(struct linpool *pool, const struct adata *list, u32 val);
const struct adata *ec_set_del(struct linpool *pool, const struct adata *list, u64 val);
const struct adata *lc_set_del(struct linpool *pool, const struct adata *list, lcomm val);
const struct adata *int_set_union(struct linpool *pool, const struct adata *l1, const struct adata *l2);
const struct adata *ec_set_union(struct linpool *pool, const struct adata *l1, const struct adata *l2);
const struct adata *lc_set_union(struct linpool *pool, const struct adata *l1, const struct adata *l2);
struct adata *ec_set_del_nontrans(struct linpool *pool, const struct adata *set);
struct adata *int_set_sort(struct linpool *pool, const struct adata *src);
struct adata *ec_set_sort(struct linpool *pool, const struct adata *src);
struct adata *lc_set_sort(struct linpool *pool, const struct adata *src);
void ec_set_sort_x(struct adata *set); /* Sort in place */
#endif
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