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/*
* BIRD Library -- Flow specification (RFC 5575)
*
* (c) 2016 CZ.NIC z.s.p.o.
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#ifndef _BIRD_FLOWSPEC_H_
#define _BIRD_FLOWSPEC_H_
#include "nest/bird.h"
#include "lib/buffer.h"
#include "lib/net.h"
/* Flow component operators */
#define FLOW_OP_TRUE 0x00 /* 0b000 */
#define FLOW_OP_EQ 0x01 /* 0b001 */
#define FLOW_OP_GT 0x02 /* 0b010 */
#define FLOW_OP_GEQ 0x03 /* 0b011 */
#define FLOW_OP_LT 0x04 /* 0b100 */
#define FLOW_OP_LEQ 0x05 /* 0b101 */
#define FLOW_OP_NEQ 0x06 /* 0b110 */
#define FLOW_OP_FALSE 0x07 /* 0b111 */
#define FLOW_OP_OR 0x00
#define FLOW_OP_AND 0x40
/* Types of components in flowspec */
enum flow_type {
FLOW_TYPE_DST_PREFIX = 1,
FLOW_TYPE_SRC_PREFIX = 2,
FLOW_TYPE_IP_PROTOCOL = 3,
FLOW_TYPE_NEXT_HEADER = 3, /* IPv6 */
FLOW_TYPE_PORT = 4,
FLOW_TYPE_DST_PORT = 5,
FLOW_TYPE_SRC_PORT = 6,
FLOW_TYPE_ICMP_TYPE = 7,
FLOW_TYPE_ICMP_CODE = 8,
FLOW_TYPE_TCP_FLAGS = 9,
FLOW_TYPE_PACKET_LENGTH = 10,
FLOW_TYPE_DSCP = 11, /* DiffServ Code Point */
FLOW_TYPE_FRAGMENT = 12,
FLOW_TYPE_LABEL = 13, /* IPv6 */
FLOW_TYPE_MAX
};
const char *flow_type_str(enum flow_type type, int ipv6);
/*
* Length
*/
uint flow_write_length(byte *data, u16 len);
static inline u16 flow_hdr_length(const byte *data)
{ return ((*data & 0xf0) == 0xf0) ? 2 : 1; }
static inline u16 flow_read_length(const byte *data)
{ return ((*data & 0xf0) == 0xf0) ? get_u16(data) & 0x0fff : *data; }
static inline u16 flow4_get_length(const net_addr_flow4 *f)
{ return f->length - sizeof(net_addr_flow4); }
static inline u16 flow6_get_length(const net_addr_flow6 *f)
{ return f->length - sizeof(net_addr_flow6); }
static inline void flow4_set_length(net_addr_flow4 *f, u16 len)
{ f->length = sizeof(net_addr_flow4) + flow_write_length(f->data, len) + len; }
static inline void flow6_set_length(net_addr_flow6 *f, u16 len)
{ f->length = sizeof(net_addr_flow6) + flow_write_length(f->data, len) + len; }
/*
* Iterators
*/
const byte *flow4_first_part(const net_addr_flow4 *f);
const byte *flow6_first_part(const net_addr_flow6 *f);
const byte *flow4_next_part(const byte *pos, const byte *end);
const byte *flow6_next_part(const byte *pos, const byte *end);
/*
* Flowspec accessors
*/
ip4_addr flow_read_ip4_part(const byte *part);
ip6_addr flow_read_ip6_part(const byte *part);
/*
* Flowspec Builder
*/
/* A data structure for keep a state of flow builder */
struct flow_builder {
BUFFER_(byte) data;
enum flow_type this_type;
enum flow_type last_type;
u16 last_op_offset; /* Position of last operator in data.data */
int ipv6;
struct {
u16 offset; /* Beginning of a component */
u16 length; /* Length of a component */
} parts[FLOW_TYPE_MAX]; /* Indexing all components */
};
struct flow_builder *flow_builder_init(pool *pool);
void flow_builder_clear(struct flow_builder *fb);
void flow_builder_set_type(struct flow_builder *fb, enum flow_type p);
int flow_builder4_add_pfx(struct flow_builder *fb, const net_addr_ip4 *n4);
int flow_builder6_add_pfx(struct flow_builder *fb, const net_addr_ip6 *n6, u32 offset);
int flow_builder_add_op_val(struct flow_builder *fb, byte op, u32 value);
int flow_builder_add_val_mask(struct flow_builder *fb, byte op, u32 value, u32 mask);
net_addr_flow4 *flow_builder4_finalize(struct flow_builder *fb, linpool *lpool);
net_addr_flow6 *flow_builder6_finalize(struct flow_builder *fb, linpool *lpool);
/*
* Validation
*/
/* Results of validation Flow specification */
enum flow_validated_state {
FLOW_ST_UNKNOWN_COMPONENT,
FLOW_ST_VALID,
FLOW_ST_NOT_COMPLETE,
FLOW_ST_EXCEED_MAX_PREFIX_LENGTH,
FLOW_ST_EXCEED_MAX_PREFIX_OFFSET,
FLOW_ST_EXCEED_MAX_VALUE_LENGTH,
FLOW_ST_BAD_TYPE_ORDER,
FLOW_ST_AND_BIT_SHOULD_BE_UNSET,
FLOW_ST_ZERO_BIT_SHOULD_BE_UNSED,
FLOW_ST_DEST_PREFIX_REQUIRED,
FLOW_ST_INVALID_TCP_FLAGS,
FLOW_ST_CANNOT_USE_DONT_FRAGMENT
};
const char *flow_validated_state_str(enum flow_validated_state code);
enum flow_validated_state flow4_validate(const byte *nlri, uint len);
enum flow_validated_state flow6_validate(const byte *nlri, uint len);
void flow_check_cf_value_length(struct flow_builder *fb, u32 expr);
void flow_check_cf_bmk_values(struct flow_builder *fb, u8 neg, u32 val, u32 mask);
void flow4_validate_cf(net_addr_flow4 *f);
void flow6_validate_cf(net_addr_flow6 *f);
/*
* Net Formatting
*/
uint flow4_net_format(char *buf, uint blen, const net_addr_flow4 *f);
uint flow6_net_format(char *buf, uint blen, const net_addr_flow6 *f);
#endif /* _BIRD_FLOWSPEC_H_ */
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