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/*
* Filters: utility functions
*
* Copyright 1998 Pavel Machek <pavel@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/signal.h>
#include <setjmp.h>
#include "nest/bird.h"
#include "lib/lists.h"
#include "lib/resource.h"
#include "lib/socket.h"
#include "nest/route.h"
#include "nest/protocol.h"
#include "nest/iface.h"
#include "conf/conf.h"
#include "filter/filter.h"
struct f_inst *startup_func = NULL;
#define runtime(x) do { \
log( L_ERR x ); \
res.type = T_RETURN; \
res.val.i = F_ERROR; \
return res; \
} while(0)
#define ARG(x,y) \
x = interpret(what->y); \
if (x.type == T_RETURN) \
return x;
#define ONEARG ARG(v1, a1.p)
#define TWOARGS ARG(v1, a1.p) \
ARG(v2, a2.p)
#define TWOARGS_C TWOARGS \
if (v1.type != v2.type) \
runtime( "Can not operate with values of incompatible types" );
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 res;
switch(what->code) {
case ',':
TWOARGS;
break;
/* Binary operators */
case '+':
TWOARGS_C;
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 '/':
TWOARGS_C;
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;
case T_IP: if (v2.type != T_INT)
runtime( "Operator / is <ip>/<int>" );
break;
default: runtime( "Usage of unknown type" );
}
break;
/* Relational operators */
case '!=':
case '==':
TWOARGS_C;
res.type = T_BOOL;
switch (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" );
}
if (what->code == '!=')
res.val.i = !(res.val.i);
break;
case '<':
TWOARGS_C;
res.type = T_BOOL;
switch (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 '<=':
TWOARGS_C;
res.type = T_BOOL;
switch (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;
/* Set */
case 's':
ARG(v2, a2.p);
sym = what->a1.p;
switch (res.type = v2.type) {
case T_VOID: runtime( "Can not assign void values" );
case T_INT:
if (sym->class != (SYM_VARIABLE | T_INT))
runtime( "Variable of bad type" );
sym->aux = v2.val.i;
break;
}
break;
case 'c':
res.type = what->a1.i;
res.val.i = (int) what->a2.p;
break;
case 'i':
res.type = what->a1.i;
res.val.i = * ((int *) what->a2.p);
break;
case 'p':
ONEARG;
switch (v1.type) {
case T_VOID: printf( "(void)" ); break;
case T_INT: printf( "%d ", v1.val.i ); break;
case T_STRING: printf( "%s", v1.val.i ); break;
default: runtime( "Print of variable of unknown type" );
}
break;
case '?': /* ? has really strange error value, so we can implement if ... else nicely :-) */
ONEARG;
if (v1.type != T_BOOL)
runtime( "If requires bool expression" );
if (v1.val.i) {
ARG(res,a2.p);
res.val.i = 0;
} else res.val.i = 1;
res.type = T_BOOL;
break;
case '0':
printf( "No operation\n" );
break;
case 'p,':
ONEARG;
printf( "\n" );
switch (what->a2.i) {
case F_QUITBIRD:
die( "Filter asked me to die" );
case F_ACCEPT:
/* Should take care about turning ACCEPT into MODIFY */
case F_ERROR:
case F_REJECT:
res.type = T_RETURN;
res.val.i = what->a1.i;
break;
case F_NOP:
break;
default:
bug( "unknown return type: can not happen");
}
break;
default:
bug( "Unknown instruction %d (%c)", what->code, what->code & 0xff);
}
if (what->next)
return interpret(what->next);
return res;
}
int
f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struct linpool *tmp_pool)
{
struct f_inst *inst;
struct f_val res;
debug( "Running filter `%s'...", filter->name );
inst = filter->root;
res = interpret(inst);
if (res.type != T_RETURN)
return F_ERROR;
debug( "done (%d)\n", res.val.i );
return res.val.i;
}
void
filters_postconfig(void)
{
struct f_val res;
if (startup_func) {
printf( "Launching startup function...\n" );
res = interpret(startup_func);
if (res.type = F_ERROR)
die( "Startup function resulted in error." );
printf( "done\n" );
}
}
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