bird/filter/filter.h

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/*
* BIRD Internet Routing Daemon -- Filters
*
* (c) 1999 Pavel Machek <pavel@ucw.cz>
* (c) 2018--2019 Maria Matejka <mq@jmq.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#ifndef _BIRD_FILT_H_
#define _BIRD_FILT_H_
#include "lib/resource.h"
#include "lib/ip.h"
#include "lib/macro.h"
#include "nest/route.h"
#include "nest/attrs.h"
/* IP prefix range structure */
struct f_prefix {
net_addr net; /* The matching prefix must match this net */
u8 lo, hi; /* And its length must fit between lo and hi */
};
/* Type numbers must be in 0..0xff range */
#define T_MASK 0xff
/* Internal types */
enum f_type {
/* Do not use type of zero, that way we'll see errors easier. */
T_VOID = 1,
/* User visible types, which fit in int */
T_INT = 0x10,
T_BOOL = 0x11,
T_PAIR = 0x12, /* Notice that pair is stored as integer: first << 16 | second */
T_QUAD = 0x13,
/* Put enumerational types in 0x30..0x3f range */
T_ENUM_LO = 0x30,
T_ENUM_HI = 0x3f,
T_ENUM_RTS = 0x30,
T_ENUM_BGP_ORIGIN = 0x31,
T_ENUM_SCOPE = 0x32,
T_ENUM_RTC = 0x33,
T_ENUM_RTD = 0x34,
T_ENUM_ROA = 0x35,
T_ENUM_NETTYPE = 0x36,
T_ENUM_RA_PREFERENCE = 0x37,
/* new enums go here */
T_ENUM_EMPTY = 0x3f, /* Special hack for atomic_aggr */
#define T_ENUM T_ENUM_LO ... T_ENUM_HI
/* Bigger ones */
T_IP = 0x20,
T_NET = 0x21,
T_STRING = 0x22,
T_PATH_MASK = 0x23, /* mask for BGP path */
T_PATH = 0x24, /* BGP path */
T_CLIST = 0x25, /* Community list */
T_EC = 0x26, /* Extended community value, u64 */
T_ECLIST = 0x27, /* Extended community list */
T_LC = 0x28, /* Large community value, lcomm */
T_LCLIST = 0x29, /* Large community list */
T_RD = 0x2a, /* Route distinguisher for VPN addresses */
T_PATH_MASK_ITEM = 0x2b, /* Path mask item for path mask constructors */
T_SET = 0x80,
T_PREFIX_SET = 0x81,
} PACKED;
/* Filter value; size of this affects filter memory consumption */
struct f_val {
enum f_type type; /* T_* */
union {
uint i;
u64 ec;
lcomm lc;
ip_addr ip;
const net_addr *net;
char *s;
const struct f_tree *t;
const struct f_trie *ti;
const struct adata *ad;
const struct f_path_mask *path_mask;
struct f_path_mask_item pmi;
} val;
};
/* Dynamic attribute definition (eattrs) */
struct f_dynamic_attr {
u8 type; /* EA type (EAF_*) */
u8 bit; /* For bitfield accessors */
enum f_type f_type; /* Filter type */
uint ea_code; /* EA code */
};
enum f_sa_code {
SA_FROM = 1,
SA_GW,
SA_NET,
SA_PROTO,
SA_SOURCE,
SA_SCOPE,
SA_DEST,
SA_IFNAME,
SA_IFINDEX,
} PACKED;
/* Static attribute definition (members of struct rta) */
struct f_static_attr {
enum f_type f_type; /* Filter type */
enum f_sa_code sa_code; /* Static attribute id */
int readonly:1; /* Don't allow writing */
};
/* Possible return values of filter execution */
enum filter_return {
F_NOP = 0,
F_NONL,
F_RETURN,
F_ACCEPT, /* Need to preserve ordering: accepts < rejects! */
F_REJECT,
F_ERROR,
F_QUITBIRD,
};
/* Filter instruction declarations */
#define FI__LIST \
F(FI_NOP) \
F(FI_ADD, ARG, ARG) \
F(FI_SUBTRACT, ARG, ARG) \
F(FI_MULTIPLY, ARG, ARG) \
F(FI_DIVIDE, ARG, ARG) \
F(FI_AND, ARG, LINE) \
F(FI_OR, ARG, LINE) \
F(FI_PAIR_CONSTRUCT, ARG, ARG) \
F(FI_EC_CONSTRUCT, ARG, ARG, ECS) \
F(FI_LC_CONSTRUCT, ARG, ARG, ARG) \
F(FI_PATHMASK_CONSTRUCT, ARG, COUNT) \
F(FI_NEQ, ARG, ARG) \
F(FI_EQ, ARG, ARG) \
F(FI_LT, ARG, ARG) \
F(FI_LTE, ARG, ARG) \
F(FI_NOT, ARG) \
F(FI_MATCH, ARG, ARG) \
F(FI_NOT_MATCH, ARG, ARG) \
F(FI_DEFINED, ARG) \
F(FI_TYPE, ARG) \
F(FI_IS_V4, ARG) \
F(FI_SET, ARG, SYMBOL) \
F(FI_CONSTANT, VALI) \
F(FI_VARIABLE, SYMBOL) \
F(FI_CONSTANT_INDIRECT, VALP) \
F(FI_PRINT, ARG) \
F(FI_CONDITION, ARG, LINE, LINE) \
F(FI_PRINT_AND_DIE, ARG, FRET) \
F(FI_RTA_GET, SA) \
F(FI_RTA_SET, SA, ARG) \
F(FI_EA_GET, EA) \
F(FI_EA_SET, EA, ARG) \
F(FI_EA_UNSET, EA) \
F(FI_PREF_GET) \
F(FI_PREF_SET, ARG) \
F(FI_LENGTH, ARG) \
F(FI_ROA_MAXLEN, ARG) \
F(FI_ROA_ASN, ARG) \
F(FI_SADR_SRC, ARG) \
F(FI_IP, ARG) \
F(FI_ROUTE_DISTINGUISHER, ARG) \
F(FI_AS_PATH_FIRST, ARG) \
F(FI_AS_PATH_LAST, ARG) \
F(FI_AS_PATH_LAST_NAG, ARG) \
F(FI_RETURN, ARG) \
F(FI_CALL, SYMBOL, LINE) \
F(FI_DROP_RESULT, ARG) \
F(FI_SWITCH, ARG, TREE) \
F(FI_IP_MASK, ARG, ARG) \
F(FI_PATH_PREPEND, ARG, ARG) \
F(FI_CLIST_ADD, ARG, ARG) \
F(FI_CLIST_DEL, ARG, ARG) \
F(FI_CLIST_FILTER, ARG, ARG) \
F(FI_ROA_CHECK_IMPLICIT, RTC) \
F(FI_ROA_CHECK_EXPLICIT, ARG, ARG, RTC) \
F(FI_FORMAT, ARG) \
F(FI_ASSERT, ARG, STRING)
/* The enum itself */
enum f_instruction_code {
#define F(c, ...) c,
FI__LIST
#undef F
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FI__MAX,
} PACKED;
/* Convert the instruction back to the enum name */
const char *f_instruction_name(enum f_instruction_code fi);
struct f_inst;
void f_inst_next(struct f_inst *first, const struct f_inst *append);
struct f_inst *f_clear_local_vars(struct f_inst *decls);
#define FIA(x) , FIA_##x
#define FIA_ARG const struct f_inst *
#define FIA_LINE const struct f_inst *
#define FIA_COUNT uint
#define FIA_SYMBOL const struct symbol *
#define FIA_VALI struct f_val
#define FIA_VALP const struct f_val *
#define FIA_FRET enum filter_return
#define FIA_ECS enum ec_subtype
#define FIA_SA struct f_static_attr
#define FIA_EA struct f_dynamic_attr
#define FIA_RTC const struct rtable_config *
#define FIA_TREE const struct f_tree *
#define FIA_STRING const char *
#define F(c, ...) \
struct f_inst *f_new_inst_##c(enum f_instruction_code MACRO_IFELSE(MACRO_ISLAST(__VA_ARGS__))()(MACRO_FOREACH(FIA, __VA_ARGS__)));
FI__LIST
#undef F
#undef FIA_ARG
#undef FIA_LINE
#undef FIA_LINEP
#undef FIA_COUNT
#undef FIA_SYMBOL
#undef FIA_VALI
#undef FIA_VALP
#undef FIA_FRET
#undef FIA_ECS
#undef FIA_SA
#undef FIA_EA
#undef FIA_RTC
#undef FIA_STRING
#undef FIA
#define f_new_inst(...) MACRO_CONCAT_AFTER(f_new_inst_, MACRO_FIRST(__VA_ARGS__))(__VA_ARGS__)
/* Flags for instructions */
enum f_instruction_flags {
FIF_PRINTED = 1, /* FI_PRINT_AND_DIE: message put in buffer */
};
/* Filter structures for execution */
struct f_line;
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/* The single instruction item */
struct f_line_item {
enum f_instruction_code fi_code; /* What to do */
enum f_instruction_flags flags; /* Flags, instruction-specific */
uint lineno; /* Where */
union {
struct {
const struct f_val *vp;
const struct symbol *sym;
};
struct f_val val;
const struct f_line *lines[2];
enum filter_return fret;
struct f_static_attr sa;
struct f_dynamic_attr da;
enum ec_subtype ecs;
const char *s;
const struct f_tree *tree;
const struct rtable_config *rtc;
uint count;
}; /* Additional instruction data */
};
/* Line of instructions to be unconditionally executed one after another */
struct f_line {
uint len; /* Line length */
struct f_line_item items[0]; /* The items themselves */
};
/* The filter encapsulating structure to be pointed-to from outside */
struct filter {
char *name;
struct f_line *root;
};
/* Convert the f_inst infix tree to the f_line structures */
struct f_line *f_postfixify_concat(const struct f_inst * const inst[], uint count);
static inline struct f_line *f_postfixify(const struct f_inst *root)
{ return f_postfixify_concat(&root, 1); }
#define F_VAL_STACK_MAX 4096
/* Value stack for execution */
struct f_val_stack {
uint cnt; /* Current stack size; 0 for empty */
struct f_val val[F_VAL_STACK_MAX]; /* The stack itself */
};
#define F_EXEC_STACK_MAX 4096
/* Exception bits */
enum f_exception {
FE_RETURN = 0x1,
};
/* Instruction stack for execution */
struct f_exec_stack {
struct {
const struct f_line *line; /* The line that is being executed */
uint pos; /* Instruction index in the line */
uint ventry; /* Value stack depth on entry */
enum f_exception emask; /* Exception mask */
} item[F_EXEC_STACK_MAX];
uint cnt; /* Current stack size; 0 for empty */
};
struct filter *f_new_where(const struct f_inst *);
static inline struct f_dynamic_attr f_new_dynamic_attr(u8 type, u8 bit, enum f_type f_type, uint code) /* Type as core knows it, type as filters know it, and code of dynamic attribute */
{ return (struct f_dynamic_attr) { .type = type, .bit = bit, .f_type = f_type, .ea_code = code }; } /* f_type currently unused; will be handy for static type checking */
static inline struct f_static_attr f_new_static_attr(int f_type, int code, int readonly)
{ return (struct f_static_attr) { .f_type = f_type, .sa_code = code, .readonly = readonly }; }
struct f_tree *f_new_tree(void);
struct f_inst *f_generate_complex(enum f_instruction_code fi_code, struct f_dynamic_attr da, struct f_inst *argument);
struct f_inst *f_generate_roa_check(struct rtable_config *table, struct f_inst *prefix, struct f_inst *asn);
struct f_tree *build_tree(struct f_tree *);
const struct f_tree *find_tree(const struct f_tree *t, const struct f_val *val);
int same_tree(const struct f_tree *t1, const struct f_tree *t2);
void tree_format(const struct f_tree *t, buffer *buf);
struct f_trie *f_new_trie(linpool *lp, uint node_size);
void *trie_add_prefix(struct f_trie *t, const net_addr *n, uint l, uint h);
int trie_match_net(const struct f_trie *t, const net_addr *n);
int trie_same(const struct f_trie *t1, const struct f_trie *t2);
void trie_format(const struct f_trie *t, buffer *buf);
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struct ea_list;
struct rte;
enum filter_return f_run(const struct filter *filter, struct rte **rte, struct linpool *tmp_pool, int flags);
enum filter_return f_eval_rte(const struct f_line *expr, struct rte **rte, struct linpool *tmp_pool);
enum filter_return f_eval(const struct f_line *expr, struct linpool *tmp_pool, struct f_val *pres);
uint f_eval_int(const struct f_line *expr);
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char *filter_name(struct filter *filter);
int filter_same(struct filter *new, struct filter *old);
int f_same(const struct f_line *f1, const struct f_line *f2);
int val_compare(const struct f_val *v1, const struct f_val *v2);
void val_format(const struct f_val *v, buffer *buf);
extern const struct f_val f_const_empty_path, f_const_empty_clist, f_const_empty_eclist, f_const_empty_lclist;
#define FILTER_ACCEPT NULL
#define FILTER_REJECT ((void *) 1)
#define FILTER_UNDEF ((void *) 2) /* Used in BGP */
struct f_tree {
struct f_tree *left, *right;
struct f_val from, to;
void *data;
};
struct f_trie_node
{
ip_addr addr, mask, accept;
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uint plen;
struct f_trie_node *c[2];
};
struct f_trie
{
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linpool *lp;
int zero;
uint node_size;
struct f_trie_node root[0]; /* Root trie node follows */
};
#define NEW_F_VAL struct f_val * val; val = cfg_alloc(sizeof(struct f_val));
#define FF_SILENT 2 /* Silent filter execution */
/* Custom route attributes */
struct custom_attribute {
resource r;
struct f_dynamic_attr *fda;
const char *name;
};
struct custom_attribute *ca_lookup(pool *p, const char *name, int ea_type);
/* Bird Tests */
struct f_bt_test_suite {
node n; /* Node in config->tests */
struct f_line *fn; /* Root of function */
const char *fn_name; /* Name of test */
const char *dsc; /* Description */
};
/* Hook for call bt_assert() function in configuration */
extern void (*bt_assert_hook)(int result, const struct f_line_item *assert);
#endif