summaryrefslogtreecommitdiffstats
path: root/filter/f-util.c
blob: ba748041a31e5010a7c64e7a6e0c011c4d7bfb76 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
/*
 *	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 "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 *last_func = NULL;

#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 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;
    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);
  }
  if (what->next)
    return interpret(what->next);
  return res;
}

void
filters_postconfig(void)
{
  if (!last_func)
    printf( "No function defined\n" );
  else {
    interpret(last_func);
  }
} 

struct f_inst *
f_new_inst(void)
{
  struct f_inst * ret;
  ret = cfg_alloc(sizeof(struct f_inst));
  ret->code = 0;
  ret->arg1 = ret->arg2 = ret->next = NULL;
  return ret;
}

int
f_run(struct symbol *filter, struct rte *rtein, struct rte **rteout)
{
  struct f_inst *inst;
  debug( "Running filter `%s'...", filter->name );

  inst = filter->def;
  interpret(inst);
  debug( "done\n" );
  return F_ACCEPT;
}