Filters upgraded - a bit. Moved code to filter.c because it is where

it belongs. (f-util.c stays there for auxiliary and non-important things.)

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" );
+}