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Filters are now a tiny bit stronger (if is actually working ;-)

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This commit is contained in:
Pavel Machek 1999-03-08 20:30:06 +00:00
parent 111213f0b6
commit b700582445
4 changed files with 130 additions and 29 deletions
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2
conf/confbase.Y
View file

@ -25,7 +25,7 @@ CF_DECLS
ip_addr a;
struct symbol *s;
char *t;
struct f_instruction *x;
struct f_inst *x;
}
%token END

51
filter/config.Y
View file

@ -19,7 +19,7 @@ CF_HDR
CF_DECLS
CF_KEYWORDS(FUNCTION, FILTER, PRINTDEBUG, INT, PRINT)
CF_KEYWORDS(FUNCTION, FILTER, PRINTDEBUG, INT, PRINT, CONST, VAR, PUTS, DIE, IF)
%type <x> term
%type <x> cmds
@ -29,7 +29,7 @@ CF_GRAMMAR
CF_ADDTO(conf, function)
function:
FUNCTION SYM '(' ')' '{' cmds '}' {
extern struct f_instruction *last_func;
extern struct f_inst *last_func;
if ($2->class != SYM_VOID) cf_error("Symbol already defined" );
$2->class = SYM_FUNCTION;
$2->def = $6;
@ -69,13 +69,47 @@ term:
/* EMPTY */ {
$$ = NULL;
}
| term '+' term {
$$ = f_new_inst();
$$->code = '+';
$$->arg1 = $1;
$$->arg2 = $3;
}
| IF '(' term ')' '{' cmds '}' {
$$ = f_new_inst();
$$->code = '?';
$$->arg1 = $3;
$$->arg2 = $6;
}
| IF '(' term ')' term {
$$ = f_new_inst();
$$->code = '?';
$$->arg1 = $3;
$$->arg2 = $5;
}
| INT SYM {
if ($2->class != SYM_VOID) cf_error("Symbol already defined, can not use as variable\n" );
$2->class = SYM_VARIABLE_INT;
printf( "New variable\n" );
$$ = NULL;
}
| SYM '=' expr {
| VAR '(' SYM ')' {
$$ = f_new_inst();
switch ($3->class) {
case SYM_VARIABLE_INT:
$$->code = 'i';
$$->arg1 = &($3->aux);
break;
default:
cf_error("Can not use this class of symbol as variable" );
}
}
| CONST '(' expr ')' {
$$ = f_new_inst();
$$->code = 'c';
$$->arg1 = $3;
}
| SYM '=' term {
$$ = f_new_inst();
printf( "Ook, we'll set value\n" );
if ($1->class != SYM_VARIABLE_INT)
@ -84,13 +118,22 @@ term:
$$->arg1 = $1;
$$->arg2 = $3;
}
| PRINT '(' SYM ')' {
| PRINT '(' term ')' {
$$ = f_new_inst();
printf( "Ook, we'll print something\n" );
$$->code = 'p';
$$->arg1 = $3;
$$->arg2 = NULL;
}
| PUTS '(' TEXT ')' {
$$ = f_new_inst();
$$->code = 'd';
$$->arg1 = $3;
}
| DIE {
$$ = f_new_inst();
$$->code = '!';
}
| PRINTDEBUG {
$$ = f_new_inst();
$$->code = 'D';

87
filter/f-util.c
View file

@ -21,42 +21,91 @@
#include "conf/conf.h"
#include "filter/filter.h"
struct f_instruction *last_func = NULL;
struct f_inst *last_func = NULL;
static void
interpret(struct f_instruction *what)
#define runtime die
static struct f_val
interpret(struct f_inst *what)
{
struct symbol *sym;
struct f_val v1, v2, res;
res.type = T_VOID;
if (!what)
return;
return res;
switch(what->code) {
case ',':
interpret(what->arg1);
interpret(what->arg2);
break;
case '+':
v1 = interpret(what->arg1);
v2 = interpret(what->arg2);
if (v1.type != v2.type)
runtime( "Can not operate with values of incompatible types" );
switch (res.type = v1.type) {
case T_VOID: runtime( "Can not operate with values of type void" );
case T_INT: res.val.i = v1.val.i + v2.val.i; break;
default: runtime( "Usage of unknown type" );
}
break;
case '=':
v1 = interpret(what->arg2);
sym = what->arg1;
sym->aux = (int) what->arg2;
break;
case 'p':
sym = what->arg1;
switch(sym->class) {
case SYM_VARIABLE_INT:
printf( "Printing: %d\n", sym->aux );
break;
default:
printf( "Unknown type passed to print\n" );
switch (res.type = v1.type) {
case T_VOID: runtime( "Can not assign void values" );
case T_INT:
if (sym->class != SYM_VARIABLE_INT)
runtime( "Variable of bad type" );
sym->aux = v1.val.i;
break;
}
break;
case 'c':
res.type = T_INT;
res.val.i = (int) what->arg1;
break;
case 'i':
res.type = T_INT;
res.val.i = * ((int *) what->arg1);
break;
case 'p':
v1 = interpret(what->arg1);
printf( "Printing: " );
switch (v1.type) {
case T_VOID: printf( "(void)" ); break;
case T_INT: printf( "%d", v1.val.i ); break;
default: runtime( "Print of variable of unknown type" );
}
printf( "\n" );
break;
case '?':
v1 = interpret(what->arg1);
if (v1.type != T_INT)
runtime( "If requires integer expression" );
if (v1.val.i)
res = interpret(what->arg2);
break;
case 'D':
printf( "DEBUGGING PRINT\n" );
break;
case '0':
printf( "No operation\n" );
break;
case 'd':
printf( "Puts: %s\n", what->arg1 );
break;
case '!':
die( "Filter asked me to die" );
default:
die( "Unknown insruction %d(%c)", what->code, what->code & 0xff);
}
interpret(what->next);
if (what->next)
return interpret(what->next);
return res;
}
void
@ -69,11 +118,11 @@ filters_postconfig(void)
}
}
struct f_instruction *
struct f_inst *
f_new_inst(void)
{
struct f_instruction * ret;
ret = cfg_alloc(sizeof(struct f_instruction));
struct f_inst * ret;
ret = cfg_alloc(sizeof(struct f_inst));
ret->code = 0;
ret->arg1 = ret->arg2 = ret->next = NULL;
return ret;
@ -82,7 +131,7 @@ f_new_inst(void)
int
f_run(struct symbol *filter, struct rte *rtein, struct rte **rteout)
{
struct f_instruction *inst;
struct f_inst *inst;
debug( "Running filter `%s'...", filter->name );
inst = filter->def;

19
filter/filter.h
View file

@ -11,19 +11,28 @@
#include "lib/resource.h"
/* Lexer */
struct f_instruction {
struct f_instruction *next; /* Structure is 16 bytes, anyway */
struct f_inst { /* Instruction */
struct f_inst *next; /* Structure is 16 bytes, anyway */
int code;
void *arg1, *arg2;
};
struct f_val {
int type;
union {
int i;
} val;
};
void filters_postconfig(void);
struct f_instruction *f_new_inst(void);
struct f_inst *f_new_inst(void);
#define F_ACCEPT 1
#define F_REJECT 2
#define F_MODIFY 3
#define T_VOID 0
#define T_INT 1
#define T_PX 2
#endif