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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
/*
* 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" );
}
}
|
