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