diff options
Diffstat (limited to 'filter/filter.c')
| -rw-r--r-- | filter/filter.c | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/filter/filter.c b/filter/filter.c new file mode 100644 index 0000000..eb40d3c --- /dev/null +++ b/filter/filter.c @@ -0,0 +1,212 @@ +/* + * 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, arg1) +#define TWOARGS ARG(v1, arg1) \ + ARG(v2, arg2) +#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, arg2); + sym = what->arg1; + 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 = (int) what->arg1; + res.val.i = (int) what->arg2; + break; + case 'i': + res.type = (int) what->arg1; + res.val.i = * ((int *) what->arg2); + 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,arg2); + 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 ((int) what->arg2) { + 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 = (int) what->arg1; + 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; + printf( "Launching startup function...\n" ); + if (startup_func) + res = interpret(startup_func); + if (res.type = F_ERROR) + die( "Startup function resulted in error." ); + printf( "done\n" ); +} |