2 * BIRD Internet Routing Daemon -- Filter instructions
4 * (c) 1999 Pavel Machek <pavel@ucw.cz>
5 * (c) 2018--2019 Maria Matejka <mq@jmq.cz>
7 * Can be freely distributed and used under the terms of the GNU GPL.
9 * Filter interpreter data structures and internal API.
10 * The filter code goes through several phases:
13 * Flex- and Bison-generated parser decodes the human-readable data into
14 * a struct f_inst tree. This is an infix tree that was interpreted by
15 * depth-first search execution in previous versions of the interpreter.
16 * All instructions have their constructor: f_new_inst(FI_code, ...)
17 * translates into f_new_inst_FI_code(...) and the types are checked in
20 * 2 Linearize before interpreting
21 * The infix tree is always interpreted in the same order. Therefore we
22 * sort the instructions one after another into struct f_line. Results
23 * and arguments of these instructions are implicitly put on a value
24 * stack; e.g. the + operation just takes two arguments from the value
25 * stack and puts the result on there.
28 * The given line is put on a custom execution stack. If needed (FI_CALL,
29 * FI_SWITCH, FI_AND, FI_OR, FI_CONDITION, ...), another line is put on top
30 * of the stack; when that line finishes, the execution continues on the
31 * older lines on the stack where it stopped before.
34 * On config reload, the filters have to be compared whether channel
35 * reload is needed or not. The comparison is done by comparing the
36 * struct f_line's recursively.
38 * The main purpose of this rework was to improve filter performance
39 * by making the interpreter non-recursive.
41 * The other outcome is concentration of instruction definitions to
42 * one place -- filter/f-inst.c
45 #ifndef _BIRD_F_INST_H_
46 #define _BIRD_F_INST_H_
48 #include "nest/bird.h"
49 #include "conf/conf.h"
50 #include "filter/filter.h"
51 #include "filter/data.h"
53 /* Flags for instructions */
54 enum f_instruction_flags
{
55 FIF_PRINTED
= 1, /* FI_PRINT_AND_DIE: message put in buffer */
58 /* Include generated filter instruction declarations */
59 #include "filter/inst-gen.h"
61 #define f_new_inst(...) MACRO_CONCAT_AFTER(f_new_inst_, MACRO_FIRST(__VA_ARGS__))(__VA_ARGS__)
63 /* Convert the instruction back to the enum name */
64 const char *f_instruction_name(enum f_instruction_code fi
);
66 /* Filter structures for execution */
67 /* Line of instructions to be unconditionally executed one after another */
69 uint len
; /* Line length */
70 u8 args
; /* Function: Args required */
72 struct f_line_item items
[0]; /* The items themselves */
75 /* Convert the f_inst infix tree to the f_line structures */
76 struct f_line
*f_linearize_concat(const struct f_inst
* const inst
[], uint count
);
77 static inline struct f_line
*f_linearize(const struct f_inst
*root
)
78 { return f_linearize_concat(&root
, 1); }
80 void f_dump_line(const struct f_line
*, uint indent
);
82 struct filter
*f_new_where(struct f_inst
*);
83 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 */
84 { 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 */
85 static inline struct f_static_attr
f_new_static_attr(int f_type
, int code
, int readonly
)
86 { return (struct f_static_attr
) { .f_type
= f_type
, .sa_code
= code
, .readonly
= readonly
}; }
87 struct f_inst
*f_generate_complex(enum f_instruction_code fi_code
, struct f_dynamic_attr da
, struct f_inst
*argument
);
88 struct f_inst
*f_generate_roa_check(struct rtable_config
*table
, struct f_inst
*prefix
, struct f_inst
*asn
);
90 /* Hook for call bt_assert() function in configuration */
91 extern void (*bt_assert_hook
)(int result
, const struct f_line_item
*assert);
94 struct f_bt_test_suite
{
95 node n
; /* Node in config->tests */
96 const struct f_line
*fn
; /* Root of function */
97 const struct f_line
*cmp
; /* Compare to this function */
98 const char *fn_name
; /* Name of test */
99 const char *dsc
; /* Description */
100 int result
; /* Desired result */