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105 lines
4.2 KiB
C
105 lines
4.2 KiB
C
/*
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* BIRD Internet Routing Daemon -- Filter instructions
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*
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* (c) 1999 Pavel Machek <pavel@ucw.cz>
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* (c) 2018--2019 Maria Matejka <mq@jmq.cz>
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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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* Filter interpreter data structures and internal API.
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* The filter code goes through several phases:
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*
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* 1 Parsing
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* Flex- and Bison-generated parser decodes the human-readable data into
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* a struct f_inst tree. This is an infix tree that was interpreted by
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* depth-first search execution in previous versions of the interpreter.
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* All instructions have their constructor: f_new_inst(FI_code, ...)
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* translates into f_new_inst_FI_code(...) and the types are checked in
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* compile time.
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*
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* 2 Postfixify before interpreting
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* The infix tree is always interpreted in the same order. Therefore we
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* sort the instructions one after another into struct f_line. Results
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* and arguments of these instructions are implicitly put on a value
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* stack; e.g. the + operation just takes two arguments from the value
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* stack and puts the result on there.
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*
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* 3 Interpret
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* The given line is put on a custom execution stack. If needed (FI_CALL,
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* FI_SWITCH, FI_AND, FI_OR, FI_CONDITION, ...), another line is put on top
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* of the stack; when that line finishes, the execution continues on the
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* older lines on the stack where it stopped before.
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*
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* 4 Same
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* On config reload, the filters have to be compared whether channel
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* reload is needed or not. The comparison is done by comparing the
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* struct f_line's recursively.
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*
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* The main purpose of this rework was to improve filter performance
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* by making the interpreter non-recursive.
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*
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* The other outcome is concentration of instruction definitions to
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* one place -- filter/f-inst.c
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*/
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#ifndef _BIRD_F_INST_H_
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#define _BIRD_F_INST_H_
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#include "nest/bird.h"
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#include "conf/conf.h"
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#include "filter/filter.h"
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#include "filter/data.h"
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/* Flags for instructions */
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enum f_instruction_flags {
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FIF_PRINTED = 1, /* FI_PRINT_AND_DIE: message put in buffer */
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} PACKED;
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/* Include generated filter instruction declarations */
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#include "filter/inst-gen.h"
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#define f_new_inst(...) MACRO_CONCAT_AFTER(f_new_inst_, MACRO_FIRST(__VA_ARGS__))(__VA_ARGS__)
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/* Convert the instruction back to the enum name */
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const char *f_instruction_name(enum f_instruction_code fi);
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struct f_inst *f_clear_local_vars(struct f_inst *decls);
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/* Filter structures for execution */
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/* Line of instructions to be unconditionally executed one after another */
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struct f_line {
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uint len; /* Line length */
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u8 args; /* Function: Args required */
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struct f_line_item items[0]; /* The items themselves */
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};
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/* Convert the f_inst infix tree to the f_line structures */
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struct f_line *f_postfixify_concat(const struct f_inst * const inst[], uint count);
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static inline struct f_line *f_postfixify(const struct f_inst *root)
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{ return f_postfixify_concat(&root, 1); }
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void f_dump_line(const struct f_line *, uint indent);
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struct filter *f_new_where(const struct f_inst *);
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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 */
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{ 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 */
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static inline struct f_static_attr f_new_static_attr(int f_type, int code, int readonly)
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{ return (struct f_static_attr) { .f_type = f_type, .sa_code = code, .readonly = readonly }; }
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struct f_inst *f_generate_complex(enum f_instruction_code fi_code, struct f_dynamic_attr da, struct f_inst *argument);
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struct f_inst *f_generate_roa_check(struct rtable_config *table, struct f_inst *prefix, struct f_inst *asn);
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/* Hook for call bt_assert() function in configuration */
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extern void (*bt_assert_hook)(int result, const struct f_line_item *assert);
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/* Bird Tests */
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struct f_bt_test_suite {
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node n; /* Node in config->tests */
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const struct f_line *fn; /* Root of function */
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const struct f_line *cmp; /* Compare to this function */
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const char *fn_name; /* Name of test */
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const char *dsc; /* Description */
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int result; /* Desired result */
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};
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#endif
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