Basic flow specification support (RFC 5575)

Add flow4/flow6 network and rt-table type and operations, config grammar
and static protocol support.

Squashed flowspec branch from Pavel Tvrdik.

1 files changed, 134 insertions, 0 deletions

diff --git a/lib/flowspec.h b/lib/flowspec.h
new file mode 100644
index 00000000..57809bec
--- /dev/null
+++ b/lib/flowspec.h
@@ -0,0 +1,134 @@
+/*
+ *	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"
+
+
+/* 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_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 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_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
+ */
+
+int flow4_net_format(char *buf, uint blen, const net_addr_flow4 *f);
+int flow6_net_format(char *buf, uint blen, const net_addr_flow6 *f);
+
+#endif /* _BIRD_FLOWSPEC_H_ */