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bird/filter/config.Y
Ondrej Zajicek aa46124804 Clear local variables in filters and functions. 
Fixes crash when used uninitialized variables.
This problem was surprisingly tricky to fix.
2010-03-19 09:41:18 +01:00

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/*
* BIRD - filters
*
* Copyright 1998--2000 Pavel Machek
*
* Can be freely distributed and used under the terms of the GNU GPL.
*
FIXME: priority of ! should be lower
*/
CF_HDR
CF_DEFINES
#define P(a,b) ((a<<8) | b)
static int make_pair(int i1, int i2)
{
unsigned u1 = i1;
unsigned u2 = i2;
if ((u1 > 0xFFFF) || (u2 > 0xFFFF))
cf_error( "Can't operate with value out of bounds in pair constructor");
return (u1 << 16) | u2;
}
CF_DECLS
CF_KEYWORDS(FUNCTION, PRINT, PRINTN, UNSET, RETURN,
ACCEPT, REJECT, ERROR, QUITBIRD,
INT, BOOL, IP, PREFIX, PAIR, SET, STRING, BGPMASK, BGPPATH, CLIST,
IF, THEN, ELSE, CASE,
TRUE, FALSE,
FROM, GW, NET, MASK, PROTO, SOURCE, SCOPE, CAST, DEST, PREFERENCE,
LEN,
DEFINED,
ADD, DELETE, CONTAINS, RESET,
PREPEND, FIRST, LAST, MATCH,
EMPTY,
FILTER, WHERE, EVAL)
%nonassoc THEN
%nonassoc ELSE
%type <x> term block cmds cmds_int cmd function_body constant print_one print_list var_list var_listn dynamic_attr static_attr function_call symbol dpair bgp_path_expr
%type <f> filter filter_body where_filter
%type <i> type break_command cpair
%type <e> set_item set_items switch_body
%type <trie> fprefix_set
%type <v> set_atom fprefix fprefix_s fipa
%type <s> decls declsn one_decl function_params
%type <h> bgp_path bgp_path_tail1 bgp_path_tail2
CF_GRAMMAR
CF_ADDTO(conf, filter_def)
filter_def:
FILTER SYM { cf_push_scope( $2 ); } filter_body {
$2 = cf_define_symbol($2, SYM_FILTER, $4);
$4->name = $2->name;
DBG( "We have new filter defined (%s)\n", $2->name );
cf_pop_scope();
}
;
CF_ADDTO(conf, filter_eval)
filter_eval:
EVAL term { f_eval_int($2); }
;
type:
INT { $$ = T_INT; }
| BOOL { $$ = T_BOOL; }
| IP { $$ = T_IP; }
| PREFIX { $$ = T_PREFIX; }
| PAIR { $$ = T_PAIR; }
| STRING { $$ = T_STRING; }
| BGPMASK { $$ = T_PATH_MASK; }
| BGPPATH { $$ = T_PATH; }
| CLIST { $$ = T_CLIST; }
| type SET {
switch ($1) {
case T_INT:
case T_IP:
case T_PAIR:
$$ = T_SET;
break;
case T_PREFIX:
$$ = T_PREFIX_SET;
break;
default:
cf_error( "You can't create sets of this type." );
}
}
;
one_decl:
type SYM {
struct f_val * val = cfg_alloc(sizeof(struct f_val));
val->type = $1;
$2 = cf_define_symbol($2, SYM_VARIABLE | $1, val);
DBG( "New variable %s type %x\n", $2->name, $1 );
$2->aux2 = NULL;
$$=$2;
}
;
/* Decls with ';' at the end */
decls: /* EMPTY */ { $$ = NULL; }
| one_decl ';' decls {
$$ = $1;
$$->aux2 = $3;
}
;
/* Declarations that have no ';' at the end. */
declsn: one_decl { $$ = $1; }
| declsn ';' one_decl {
$$ = $1;
$$->aux2 = $3;
}
;
filter_body:
function_body {
struct filter *f = cfg_alloc(sizeof(struct filter));
f->name = NULL;
f->root = $1;
$$ = f;
}
;
filter:
SYM {
if ($1->class != SYM_FILTER) cf_error("No such filter.");
$$ = $1->def;
}
| filter_body
;
where_filter:
WHERE term {
/* Construct 'IF term THEN ACCEPT; REJECT;' */
struct filter *f = cfg_alloc(sizeof(struct filter));
struct f_inst *i, *acc, *rej;
acc = f_new_inst(); /* ACCEPT */
acc->code = P('p',',');
acc->a1.p = NULL;
acc->a2.i = F_ACCEPT;
rej = f_new_inst(); /* REJECT */
rej->code = P('p',',');
rej->a1.p = NULL;
rej->a2.i = F_REJECT;
i = f_new_inst(); /* IF */
i->code = '?';
i->a1.p = $2;
i->a2.p = acc;
i->next = rej;
f->name = NULL;
f->root = i;
$$ = f;
}
;
function_params:
'(' declsn ')' { DBG( "Have function parameters\n" ); $$=$2; }
| '(' ')' { $$=NULL; }
;
function_body:
decls '{' cmds '}' {
if ($1) {
/* Prepend instruction to clear local variables */
$$ = f_new_inst();
$$->code = P('c','v');
$$->a1.p = $1;
$$->next = $3;
} else
$$ = $3;
}
;
CF_ADDTO(conf, function_def)
function_def:
FUNCTION SYM { DBG( "Beginning of function %s\n", $2->name );
$2 = cf_define_symbol($2, SYM_FUNCTION, NULL);
cf_push_scope($2);
} function_params function_body {
$2->def = $5;
$2->aux2 = $4;
DBG("Hmm, we've got one function here - %s\n", $2->name);
cf_pop_scope();
}
;
/* Programs */
/* Hack: $$ of cmds_int is the last node.
$$->next of cmds_int is temporary used for the first node */
cmds: /* EMPTY */ { $$ = NULL; }
| cmds_int { $$ = $1->next; $1->next = NULL; }
;
cmds_int: cmd { $$ = $1; $1->next = $1; }
| cmds_int cmd { $$ = $2; $2->next = $1->next ; $1->next = $2; }
;
block:
cmd {
$$=$1;
}
| '{' cmds '}' {
$$=$2;
}
;
/*
* Simple types, their bison value is int
*/
cpair:
'(' NUM ',' NUM ')' { $$ = make_pair($2, $4); }
;
/*
* Complex types, their bison value is struct f_val
*/
fipa:
IPA %prec PREFIX_DUMMY { $$.type = T_IP; $$.val.px.ip = $1; }
;
set_atom:
NUM { $$.type = T_INT; $$.val.i = $1; }
| cpair { $$.type = T_PAIR; $$.val.i = $1; }
| fipa { $$ = $1; }
| ENUM { $$.type = $1 >> 16; $$.val.i = $1 & 0xffff; }
;
set_item:
set_atom {
$$ = f_new_tree();
$$->from = $1;
$$->to = $1;
}
| set_atom '.' '.' set_atom {
$$ = f_new_tree();
$$->from = $1;
$$->to = $4;
}
;
set_items:
set_item { $$ = $1; }
| set_items ',' set_item { $$ = $3; $$->left = $1; }
;
fprefix_s:
IPA '/' NUM %prec '/' {
if (($3 < 0) || ($3 > MAX_PREFIX_LENGTH) || !ip_is_prefix($1, $3)) cf_error("Invalid network prefix: %I/%d.", $1, $3);
$$.type = T_PREFIX; $$.val.px.ip = $1; $$.val.px.len = $3;
}
;
fprefix:
fprefix_s { $$ = $1; }
| fprefix_s '+' { $$ = $1; $$.val.px.len |= LEN_PLUS; }
| fprefix_s '-' { $$ = $1; $$.val.px.len |= LEN_MINUS; }
| fprefix_s '{' NUM ',' NUM '}' {
if (! ((0 <= $3) && ($3 <= $5) && ($5 <= MAX_PREFIX_LENGTH))) cf_error("Invalid prefix pattern range: {%d, %d}.", $3, $5);
$$ = $1; $$.val.px.len |= LEN_RANGE | ($3 << 16) | ($5 << 8);
}
;
fprefix_set:
fprefix { $$ = f_new_trie(); trie_add_prefix($$, &($1.val.px)); }
| fprefix_set ',' fprefix { $$ = $1; trie_add_prefix($$, &($3.val.px)); }
;
switch_body: /* EMPTY */ { $$ = NULL; }
| switch_body set_item ':' cmds {
$$ = $2;
$$->data = $4;
$$->left = $1;
}
| switch_body ELSE ':' cmds {
$$ = f_new_tree();
$$->from.type = T_VOID;
$$->to.type = T_VOID;
$$->data = $4;
$$->left = $1;
}
;
/* CONST '(' expr ')' { $$ = f_new_inst(); $$->code = 'c'; $$->aux = T_INT; $$->a2.i = $3; } */
bgp_path_expr:
symbol { $$ = $1; }
| '(' term ')' { $$ = $2; }
;
bgp_path:
PO bgp_path_tail1 PC { $$ = $2; }
| '/' bgp_path_tail2 '/' { $$ = $2; }
;
bgp_path_tail1:
NUM bgp_path_tail1 { $$ = cfg_alloc(sizeof(struct f_path_mask)); $$->next = $2; $$->kind = PM_ASN; $$->val = $1; }
| '*' bgp_path_tail1 { $$ = cfg_alloc(sizeof(struct f_path_mask)); $$->next = $2; $$->kind = PM_ASTERISK; $$->val = 0; }
| '?' bgp_path_tail1 { $$ = cfg_alloc(sizeof(struct f_path_mask)); $$->next = $2; $$->kind = PM_QUESTION; $$->val = 0; }
| bgp_path_expr bgp_path_tail1 { $$ = cfg_alloc(sizeof(struct f_path_mask)); $$->next = $2; $$->kind = PM_ASN_EXPR; $$->val = (uintptr_t) $1; }
| { $$ = NULL; }
;
bgp_path_tail2:
NUM bgp_path_tail2 { $$ = cfg_alloc(sizeof(struct f_path_mask)); $$->next = $2; $$->kind = PM_ASN; $$->val = $1; }
| '?' bgp_path_tail2 { $$ = cfg_alloc(sizeof(struct f_path_mask)); $$->next = $2; $$->kind = PM_ASTERISK; $$->val = 0; }
| { $$ = NULL; }
;
dpair:
'(' term ',' term ')' {
if (($2->code == 'c') && ($4->code == 'c'))
{
if (($2->aux != T_INT) || ($4->aux != T_INT))
cf_error( "Can't operate with value of non-integer type in pair constructor" );
$$ = f_new_inst(); $$->code = 'c'; $$->aux = T_PAIR; $$->a2.i = make_pair($2->a2.i, $4->a2.i);
}
else
{ $$ = f_new_inst(); $$->code = P('m', 'p'); $$->a1.p = $2; $$->a2.p = $4; }
}
;
constant:
NUM { $$ = f_new_inst(); $$->code = 'c'; $$->aux = T_INT; $$->a2.i = $1; }
| TRUE { $$ = f_new_inst(); $$->code = 'c'; $$->aux = T_BOOL; $$->a2.i = 1; }
| FALSE { $$ = f_new_inst(); $$->code = 'c'; $$->aux = T_BOOL; $$->a2.i = 0; }
| TEXT { $$ = f_new_inst(); $$->code = 'c'; $$->aux = T_STRING; $$->a2.p = $1; }
| fipa { NEW_F_VAL; $$ = f_new_inst(); $$->code = 'C'; $$->a1.p = val; *val = $1; }
| fprefix_s {NEW_F_VAL; $$ = f_new_inst(); $$->code = 'C'; $$->a1.p = val; *val = $1; }
| '[' set_items ']' { DBG( "We've got a set here..." ); $$ = f_new_inst(); $$->code = 'c'; $$->aux = T_SET; $$->a2.p = build_tree($2); DBG( "ook\n" ); }
| '[' fprefix_set ']' { $$ = f_new_inst(); $$->code = 'c'; $$->aux = T_PREFIX_SET; $$->a2.p = $2; }
| ENUM { $$ = f_new_inst(); $$->code = 'c'; $$->aux = $1 >> 16; $$->a2.i = $1 & 0xffff; }
| bgp_path { NEW_F_VAL; $$ = f_new_inst(); $$->code = 'C'; val->type = T_PATH_MASK; val->val.path_mask = $1; $$->a1.p = val; }
;
/*
* Maybe there are no dynamic attributes defined by protocols.
* For such cases, we force the dynamic_attr list to contain
* at least an invalid token, so it's syntantically correct.
*/
CF_ADDTO(dynamic_attr, INVALID_TOKEN { $$ = NULL; })
rtadot: /* EMPTY, we are not permitted RTA. prefix */
;
function_call:
SYM '(' var_list ')' {
struct symbol *sym;
struct f_inst *inst = $3;
if ($1->class != SYM_FUNCTION)
cf_error("You can't call something which is not a function. Really.");
DBG("You are calling function %s\n", $1->name);
$$ = f_new_inst();
$$->code = P('c','a');
$$->a1.p = inst;
$$->a2.p = $1->def;
sym = $1->aux2;
while (sym || inst) {
if (!sym || !inst)
cf_error("Wrong number of arguments for function %s.", $1->name);
DBG( "You should pass parameter called %s\n", sym->name);
inst->a1.p = sym;
sym = sym->aux2;
inst = inst->next;
}
}
;
symbol:
SYM {
$$ = f_new_inst();
switch ($1->class) {
case SYM_NUMBER:
$$ = f_new_inst();
$$->code = 'c';
$$->aux = T_INT;
$$->a2.i = $1->aux;
break;
case SYM_IPA:
{ NEW_F_VAL; $$ = f_new_inst(); $$->code = 'C'; $$->a1.p = val; val->type = T_IP; val->val.px.ip = * (ip_addr *) ($1->def); }
break;
case SYM_VARIABLE | T_BOOL:
case SYM_VARIABLE | T_INT:
case SYM_VARIABLE | T_PAIR:
case SYM_VARIABLE | T_STRING:
case SYM_VARIABLE | T_IP:
case SYM_VARIABLE | T_PREFIX:
case SYM_VARIABLE | T_PREFIX_SET:
case SYM_VARIABLE | T_SET:
case SYM_VARIABLE | T_PATH:
case SYM_VARIABLE | T_PATH_MASK:
case SYM_VARIABLE | T_CLIST:
$$->code = 'V';
$$->a1.p = $1->def;
$$->a2.p = $1->name;
break;
default:
cf_error("%s: variable expected.", $1->name );
}
}
static_attr:
FROM { $$ = f_new_inst(); $$->aux = T_IP; $$->a2.i = OFFSETOF(struct rta, from); $$->a1.i = 1; }
| GW { $$ = f_new_inst(); $$->aux = T_IP; $$->a2.i = OFFSETOF(struct rta, gw); $$->a1.i = 1; }
| NET { $$ = f_new_inst(); $$->aux = T_PREFIX; $$->a2.i = 0x12345678; /* This is actually ok - T_PREFIX is special-cased. */ }
| PROTO { $$ = f_new_inst(); $$->aux = T_STRING; $$->a2.i = 0x12345678; /* T_STRING is also special-cased. */ }
| SOURCE { $$ = f_new_inst(); $$->aux = T_ENUM_RTS; $$->a2.i = OFFSETOF(struct rta, source); }
| SCOPE { $$ = f_new_inst(); $$->aux = T_ENUM_SCOPE; $$->a2.i = OFFSETOF(struct rta, scope); $$->a1.i = 1; }
| CAST { $$ = f_new_inst(); $$->aux = T_ENUM_RTC; $$->a2.i = OFFSETOF(struct rta, cast); }
| DEST { $$ = f_new_inst(); $$->aux = T_ENUM_RTD; $$->a2.i = OFFSETOF(struct rta, dest); }
;
term:
'(' term ')' { $$ = $2; }
| term '+' term { $$ = f_new_inst(); $$->code = '+'; $$->a1.p = $1; $$->a2.p = $3; }
| term '-' term { $$ = f_new_inst(); $$->code = '-'; $$->a1.p = $1; $$->a2.p = $3; }
| term '*' term { $$ = f_new_inst(); $$->code = '*'; $$->a1.p = $1; $$->a2.p = $3; }
| term '/' term { $$ = f_new_inst(); $$->code = '/'; $$->a1.p = $1; $$->a2.p = $3; }
| term AND term { $$ = f_new_inst(); $$->code = '&'; $$->a1.p = $1; $$->a2.p = $3; }
| term OR term { $$ = f_new_inst(); $$->code = '|'; $$->a1.p = $1; $$->a2.p = $3; }
| term '=' term { $$ = f_new_inst(); $$->code = P('=','='); $$->a1.p = $1; $$->a2.p = $3; }
| term NEQ term { $$ = f_new_inst(); $$->code = P('!','='); $$->a1.p = $1; $$->a2.p = $3; }
| term '<' term { $$ = f_new_inst(); $$->code = '<'; $$->a1.p = $1; $$->a2.p = $3; }
| term LEQ term { $$ = f_new_inst(); $$->code = P('<','='); $$->a1.p = $1; $$->a2.p = $3; }
| term '>' term { $$ = f_new_inst(); $$->code = '<'; $$->a1.p = $3; $$->a2.p = $1; }
| term GEQ term { $$ = f_new_inst(); $$->code = P('<','='); $$->a1.p = $3; $$->a2.p = $1; }
| term '~' term { $$ = f_new_inst(); $$->code = '~'; $$->a1.p = $1; $$->a2.p = $3; }
| '!' term { $$ = f_new_inst(); $$->code = '!'; $$->a1.p = $2; }
| DEFINED '(' term ')' { $$ = f_new_inst(); $$->code = P('d','e'); $$->a1.p = $3; }
| symbol { $$ = $1; }
| constant { $$ = $1; }
| dpair { $$ = $1; }
| PREFERENCE { $$ = f_new_inst(); $$->code = 'P'; }
| rtadot static_attr { $$ = $2; $$->code = 'a'; }
| rtadot dynamic_attr { $$ = $2; $$->code = P('e','a'); }
| term '.' IP { $$ = f_new_inst(); $$->code = P('c','p'); $$->a1.p = $1; $$->aux = T_IP; }
| term '.' LEN { $$ = f_new_inst(); $$->code = 'L'; $$->a1.p = $1; }
| term '.' MASK '(' term ')' { $$ = f_new_inst(); $$->code = P('i','M'); $$->a1.p = $1; $$->a2.p = $5; }
| term '.' FIRST { $$ = f_new_inst(); $$->code = P('a','f'); $$->a1.p = $1; }
| term '.' LAST { $$ = f_new_inst(); $$->code = P('a','l'); $$->a1.p = $1; }
/* Communities */
/* This causes one shift/reduce conflict
| rtadot dynamic_attr '.' ADD '(' term ')' { }
| rtadot dynamic_attr '.' DELETE '(' term ')' { }
| rtadot dynamic_attr '.' CONTAINS '(' term ')' { }
| rtadot dynamic_attr '.' RESET{ }
*/
| '+' EMPTY '+' { $$ = f_new_inst(); $$->code = 'E'; $$->aux = T_PATH; }
| '-' EMPTY '-' { $$ = f_new_inst(); $$->code = 'E'; $$->aux = T_CLIST; }
| PREPEND '(' term ',' term ')' { $$ = f_new_inst(); $$->code = P('A','p'); $$->a1.p = $3; $$->a2.p = $5; }
| ADD '(' term ',' term ')' { $$ = f_new_inst(); $$->code = P('C','a'); $$->a1.p = $3; $$->a2.p = $5; $$->aux = 'a'; }
| DELETE '(' term ',' term ')' { $$ = f_new_inst(); $$->code = P('C','a'); $$->a1.p = $3; $$->a2.p = $5; $$->aux = 'd'; }
/* | term '.' LEN { $$->code = P('P','l'); } */
/* function_call is inlined here */
| SYM '(' var_list ')' {
struct symbol *sym;
struct f_inst *inst = $3;
if ($1->class != SYM_FUNCTION)
cf_error("You can't call something which is not a function. Really.");
DBG("You are calling function %s\n", $1->name);
$$ = f_new_inst();
$$->code = P('c','a');
$$->a1.p = inst;
$$->a2.p = $1->def;
sym = $1->aux2;
while (sym || inst) {
if (!sym || !inst)
cf_error("Wrong number of arguments for function %s.", $1->name);
DBG( "You should pass parameter called %s\n", sym->name);
inst->a1.p = sym;
sym = sym->aux2;
inst = inst->next;
}
}
;
break_command:
QUITBIRD { $$ = F_QUITBIRD; }
| ACCEPT { $$ = F_ACCEPT; }
| REJECT { $$ = F_REJECT; }
| ERROR { $$ = F_ERROR; }
| PRINT { $$ = F_NOP; }
| PRINTN { $$ = F_NONL; }
;
print_one:
term { $$ = f_new_inst(); $$->code = 'p'; $$->a1.p = $1; $$->a2.p = NULL; }
;
print_list: /* EMPTY */ { $$ = NULL; }
| print_one { $$ = $1; }
| print_one ',' print_list {
if ($1) {
$1->next = $3;
$$ = $1;
} else $$ = $3;
}
;
var_listn: term {
$$ = f_new_inst();
$$->code = 's';
$$->a1.p = NULL;
$$->a2.p = $1;
$$->next = NULL;
}
| term ',' var_listn {
$$ = f_new_inst();
$$->code = 's';
$$->a1.p = NULL;
$$->a2.p = $1;
$$->next = $3;
}
;
var_list: /* EMPTY */ { $$ = NULL; }
| var_listn { $$ = $1; }
;
cmd:
IF term THEN block {
$$ = f_new_inst();
$$->code = '?';
$$->a1.p = $2;
$$->a2.p = $4;
}
| IF term THEN block ELSE block {
struct f_inst *i = f_new_inst();
i->code = '?';
i->a1.p = $2;
i->a2.p = $4;
$$ = f_new_inst();
$$->code = '?';
$$->a1.p = i;
$$->a2.p = $6;
}
| SYM '=' term ';' {
$$ = f_new_inst();
DBG( "Ook, we'll set value\n" );
if (($1->class & ~T_MASK) != SYM_VARIABLE)
cf_error( "You may set only variables." );
$$->code = 's';
$$->a1.p = $1;
$$->a2.p = $3;
}
| RETURN term ';' {
$$ = f_new_inst();
DBG( "Ook, we'll return the value\n" );
$$->code = 'r';
$$->a1.p = $2;
}
| rtadot dynamic_attr '=' term ';' {
$$ = $2;
$$->code = P('e','S');
$$->a1.p = $4;
}
| rtadot static_attr '=' term ';' {
$$ = $2;
if (!$$->a1.i)
cf_error( "This static attribute is read-only.");
$$->code = P('a','S');
$$->a1.p = $4;
}
| PREFERENCE '=' term ';' {
$$ = f_new_inst();
$$->code = P('P','S');
$$->a1.p = $3;
}
| UNSET '(' rtadot dynamic_attr ')' ';' {
$$ = $4;
$$->aux = EAF_TYPE_UNDEF | EAF_TEMP;
$$->code = P('e','S');
$$->a1.p = NULL;
}
| break_command print_list ';' { $$ = f_new_inst(); $$->code = P('p',','); $$->a1.p = $2; $$->a2.i = $1; }
| function_call ';' { $$ = $1; }
| CASE term '{' switch_body '}' {
$$ = f_new_inst();
$$->code = P('S','W');
$$->a1.p = $2;
$$->a2.p = build_tree( $4 );
}
| rtadot dynamic_attr '.' EMPTY ';'
{ struct f_inst *i = f_new_inst(); i->code = 'E'; i->aux = T_CLIST; $$ = $2; $$->code = P('e','S'); $$->a1.p = i; }
| rtadot dynamic_attr '.' PREPEND '(' term ')' ';' { $$ = f_generate_complex( P('A','p'), 'x', $2, $6 ); }
| rtadot dynamic_attr '.' ADD '(' term ')' ';' { $$ = f_generate_complex( P('C','a'), 'a', $2, $6 ); }
| rtadot dynamic_attr '.' DELETE '(' term ')' ';' { $$ = f_generate_complex( P('C','a'), 'd', $2, $6 ); }
;
CF_END
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