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bird/filter/filter.c
Ondrej Zajicek c8a6b9a3d1 Rewrite of buggy AS path matching. 
Old AS path maching supposes thath AS number appears
only once in AS path, but that is not true. It also
contains some bugs related to AS path sets.

New code does not use any assumptions about semantic
structure of AS path. It is asymptotically slower than
the old code, but on real paths it is not significant.

It also allows '?' for matching one arbitrary AS number.
2009-04-17 01:48:36 +02:00

969 lines
24 KiB
C
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/*
* Filters: utility functions
*
* Copyright 1998 Pavel Machek <pavel@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*
*/
/**
* DOC: Filters
*
* You can find sources of the filter language in |filter/|
* directory. File |filter/config.Y| contains filter grammar and basically translates
* the source from user into a tree of &f_inst structures. These trees are
* later interpreted using code in |filter/filter.c|.
*
* A filter is represented by a tree of &f_inst structures, one structure per
* "instruction". Each &f_inst contains @code, @aux value which is
* usually the data type this instruction operates on and two generic
* arguments (@a1, @a2). Some instructions contain pointer(s) to other
* instructions in their (@a1, @a2) fields.
*
* Filters use a &f_val structure for their data. Each &f_val
* contains type and value (types are constants prefixed with %T_). Few
* of the types are special; %T_RETURN can be or-ed with a type to indicate
* that return from a function or from the whole filter should be
* forced. Important thing about &f_val's is that they may be copied
* with a simple |=|. That's fine for all currently defined types: strings
* are read-only (and therefore okay), paths are copied for each
* operation (okay too).
*/
#undef LOCAL_DEBUG
#include "nest/bird.h"
#include "lib/lists.h"
#include "lib/resource.h"
#include "lib/socket.h"
#include "lib/string.h"
#include "lib/unaligned.h"
#include "nest/route.h"
#include "nest/protocol.h"
#include "nest/iface.h"
#include "nest/attrs.h"
#include "conf/conf.h"
#include "filter/filter.h"
#define P(a,b) ((a<<8) | b)
#define CMP_ERROR 999
static struct adata *
adata_empty(struct linpool *pool)
{
struct adata *res = lp_alloc(pool, sizeof(struct adata));
res->length = 0;
return res;
}
static int
pm_path_compare(struct f_path_mask *m1, struct f_path_mask *m2)
{
while (1) {
if ((!m1) || (!m2))
return !((!m1) && (!m2));
m1 = m1->next;
m2 = m2->next;
}
}
static void
pm_format(struct f_path_mask *p, byte *buf, unsigned int size)
{
byte *end = buf + size - 16;
while (p)
{
if (buf > end)
{
strcpy(buf, " ...");
return;
}
if (p->kind == PM_ASN)
buf += bsprintf(buf, " %u", p->val);
else
buf += bsprintf(buf, (p->kind == PM_ASTERISK) ? " *" : " ?");
p = p->next;
}
*buf = 0;
}
/**
* val_compare - compare two values
* @v1: first value
* @v2: second value
*
* Compares two values and returns -1, 0, 1 on <, =, > or 999 on error.
* Tree module relies on this giving consistent results so that it can
* build balanced trees.
*/
int
val_compare(struct f_val v1, struct f_val v2)
{
int rc;
if ((v1.type == T_VOID) && (v2.type == T_VOID))
return 0;
if (v1.type == T_VOID) /* Hack for else */
return -1;
if (v2.type == T_VOID)
return 1;
if (v1.type != v2.type) {
debug( "Types do not match in val_compare\n" );
return CMP_ERROR;
}
switch (v1.type) {
case T_ENUM:
case T_INT:
case T_PAIR:
if (v1.val.i == v2.val.i) return 0;
if (v1.val.i < v2.val.i) return -1;
return 1;
case T_IP:
return ipa_compare(v1.val.px.ip, v2.val.px.ip);
case T_PREFIX:
if (rc = ipa_compare(v1.val.px.ip, v2.val.px.ip))
return rc;
if (v1.val.px.len < v2.val.px.len)
return -1;
if (v1.val.px.len > v2.val.px.len)
return 1;
return 0;
case T_PATH_MASK:
return pm_path_compare(v1.val.path_mask, v2.val.path_mask);
case T_STRING:
return strcmp(v1.val.s, v2.val.s);
default:
debug( "Compare of unkown entities: %x\n", v1.type );
return CMP_ERROR;
}
}
void
f_prefix_get_bounds(struct f_prefix *px, int *l, int *h)
{
*l = *h = px->len & LEN_MASK;
if (px->len & LEN_MINUS)
*l = 0;
else if (px->len & LEN_PLUS)
*h = MAX_PREFIX_LENGTH;
else if (px->len & LEN_RANGE)
{
*l = 0xff & (px->len >> 16);
*h = 0xff & (px->len >> 8);
}
}
/*
* val_simple_in_range - check if @v1 ~ @v2 for everything except sets
*/
static int
val_simple_in_range(struct f_val v1, struct f_val v2)
{
if ((v1.type == T_PATH) && (v2.type == T_PATH_MASK))
return as_path_match(v1.val.ad, v2.val.path_mask);
if ((v1.type == T_PAIR) && (v2.type == T_CLIST))
return int_set_contains(v2.val.ad, v1.val.i);
if ((v1.type == T_STRING) && (v2.type == T_STRING))
return patmatch(v2.val.s, v1.val.s);
if ((v1.type == T_IP) && (v2.type == T_PREFIX))
return !(ipa_compare(ipa_and(v2.val.px.ip, ipa_mkmask(v2.val.px.len)), ipa_and(v1.val.px.ip, ipa_mkmask(v2.val.px.len))));
if ((v1.type == T_PREFIX) && (v2.type == T_PREFIX)) {
if (v1.val.px.len & (LEN_PLUS | LEN_MINUS | LEN_RANGE))
return CMP_ERROR;
int p1 = v1.val.px.len & LEN_MASK;
int p2 = v2.val.px.len & LEN_MASK;
ip_addr mask = ipa_mkmask(MIN(p1, p2));
if (ipa_compare(ipa_and(v2.val.px.ip, mask), ipa_and(v1.val.px.ip, mask)))
return 0;
int l, h;
f_prefix_get_bounds(&v2.val.px, &l, &h);
return ((l <= v1.val.px.len) && (v1.val.px.len <= h));
}
return CMP_ERROR;
}
/**
* val_in_range - implement |~| operator
* @v1: element
* @v2: set
*
* Checks if @v1 is element (|~| operator) of @v2. Sets are internally represented as balanced trees, see
* |tree.c| module (this is not limited to sets, but for non-set cases, val_simple_in_range() is called early).
*/
static int
val_in_range(struct f_val v1, struct f_val v2)
{
int res;
res = val_simple_in_range(v1, v2);
if (res != CMP_ERROR)
return res;
if ((v1.type == T_PREFIX) && (v2.type == T_PREFIX_SET))
return trie_match_prefix(v2.val.ti, &v1.val.px);
if (v2.type == T_SET)
switch (v1.type) {
case T_ENUM:
case T_INT:
case T_IP:
case T_PREFIX:
{
struct f_tree *n;
n = find_tree(v2.val.t, v1);
if (!n)
return 0;
return !! (val_simple_in_range(v1, n->from)); /* We turn CMP_ERROR into compared ok, and that's fine */
}
}
return CMP_ERROR;
}
static void
tree_print(struct f_tree *t)
{
if (!t) {
debug( "() " );
return;
}
debug( "[ " );
tree_print( t->left );
debug( ", " ); val_print( t->from ); debug( ".." ); val_print( t->to ); debug( ", " );
tree_print( t->right );
debug( "] " );
}
/*
* val_print - format filter value
*/
void
val_print(struct f_val v)
{
char buf[2048];
char buf2[1024];
#define PRINTF(a...) bsnprintf( buf, 2040, a )
buf[0] = 0;
switch (v.type) {
case T_VOID: PRINTF( "(void)" ); break;
case T_BOOL: PRINTF( v.val.i ? "TRUE" : "FALSE" ); break;
case T_INT: PRINTF( "%d ", v.val.i ); break;
case T_STRING: PRINTF( "%s", v.val.s ); break;
case T_IP: PRINTF( "%I", v.val.px.ip ); break;
case T_PREFIX: PRINTF( "%I/%d", v.val.px.ip, v.val.px.len ); break;
case T_PAIR: PRINTF( "(%d,%d)", v.val.i >> 16, v.val.i & 0xffff ); break;
case T_PREFIX_SET: trie_print(v.val.ti, buf, 2040); break;
case T_SET: tree_print( v.val.t ); PRINTF( "\n" ); break;
case T_ENUM: PRINTF( "(enum %x)%d", v.type, v.val.i ); break;
case T_PATH: as_path_format(v.val.ad, buf2, 1020); PRINTF( "(path %s)", buf2 ); break;
case T_CLIST: int_set_format(v.val.ad, 1, buf2, 1020); PRINTF( "(clist %s)", buf2 ); break;
case T_PATH_MASK: pm_format(v.val.path_mask, buf2, 1020); PRINTF( "(pathmask%s)", buf2 ); break;
default: PRINTF( "[unknown type %x]", v.type );
#undef PRINTF
}
debug( buf );
}
static struct rte **f_rte, *f_rte_old;
static struct linpool *f_pool;
static struct ea_list **f_tmp_attrs;
static int f_flags;
static rta *f_rta_copy;
/*
* rta_cow - prepare rta for modification by filter
*/
static void
rta_cow(void)
{
if (!f_rta_copy) {
f_rta_copy = lp_alloc(f_pool, sizeof(rta));
memcpy(f_rta_copy, (*f_rte)->attrs, sizeof(rta));
f_rta_copy->aflags = 0;
*f_rte = rte_cow(*f_rte);
rta_free((*f_rte)->attrs);
(*f_rte)->attrs = f_rta_copy;
}
}
static struct rate_limit rl_runtime_err;
#define runtime(x) do { \
log_rl(&rl_runtime_err, L_ERR "filters, line %d: %s", what->lineno, 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't operate with values of incompatible types" );
/**
* interpret
* @what: filter to interpret
*
* Interpret given tree of filter instructions. This is core function
* of filter system and does all the hard work.
*
* Each instruction has 4 fields: code (which is instruction code),
* aux (which is extension to instruction code, typically type),
* arg1 and arg2 - arguments. Depending on instruction, arguments
* are either integers, or pointers to instruction trees. Common
* instructions like +, that have two expressions as arguments use
* TWOARGS macro to get both of them evaluated.
*
* &f_val structures are copied around, so there are no problems with
* memory managment.
*/
static struct f_val
interpret(struct f_inst *what)
{
struct symbol *sym;
struct f_val v1, v2, res;
int i;
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't 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't 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't 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't operate with values of type void" );
case T_INT: if (v2.val.i == 0) runtime( "Mother told me not to divide by 0" );
res.val.i = v1.val.i / v2.val.i; break;
case T_IP: if (v2.type != T_INT)
runtime( "Incompatible types in / operator" );
break;
default: runtime( "Usage of unknown type" );
}
break;
case '&':
TWOARGS_C;
res.type = v1.type;
if (res.type != T_BOOL) runtime( "Can't do boolean operation on non-booleans" );
res.val.i = v1.val.i && v2.val.i;
break;
case '|':
TWOARGS_C;
res.type = v1.type;
if (res.type != T_BOOL) runtime( "Can't do boolean operation on non-booleans" );
res.val.i = v1.val.i || v2.val.i;
break;
/* Relational operators */
#define COMPARE(x) \
TWOARGS_C; \
res.type = T_BOOL; \
i = val_compare(v1, v2); \
if (i==CMP_ERROR) \
runtime( "Error in comparison" ); \
res.val.i = (x); \
break;
case P('!','='): COMPARE(i!=0);
case P('=','='): COMPARE(i==0);
case '<': COMPARE(i==-1);
case P('<','='): COMPARE(i!=1);
case '!':
ONEARG;
if (v1.type != T_BOOL)
runtime( "Not applied to non-boolean" );
res = v1;
res.val.i = !res.val.i;
break;
case '~':
TWOARGS;
res.type = T_BOOL;
res.val.i = val_in_range(v1, v2);
if (res.val.i == CMP_ERROR)
runtime( "~ applied on unknown type pair" );
break;
case P('d','e'):
ONEARG;
res.type = T_BOOL;
res.val.i = (v1.type != T_VOID);
break;
/* Set to indirect value, a1 = variable, a2 = value */
case 's':
ARG(v2, a2.p);
sym = what->a1.p;
switch (res.type = v2.type) {
case T_VOID: runtime( "Can't assign void values" );
case T_ENUM:
case T_BOOL:
case T_INT:
case T_PAIR:
case T_STRING:
case T_IP:
case T_PREFIX:
case T_PREFIX_SET:
case T_SET:
case T_PATH:
case T_PATH_MASK:
case T_CLIST:
if (sym->class != (SYM_VARIABLE | v2.type))
runtime( "Assigning to variable of incompatible type" );
* (struct f_val *) sym->def = v2;
break;
default:
bug( "Set to invalid type" );
}
break;
/* some constants have value in a2, some in *a1.p, strange. */
case 'c': /* integer (or simple type) constant, string, set, or prefix_set */
res.type = what->aux;
if (res.type == T_PREFIX_SET)
res.val.ti = what->a2.p;
else if (res.type == T_SET)
res.val.t = what->a2.p;
else if (res.type == T_STRING)
res.val.s = what->a2.p;
else
res.val.i = what->a2.i;
break;
case 'C':
res = * ((struct f_val *) what->a1.p);
break;
case 'p':
ONEARG;
val_print(v1);
break;
case '?': /* ? has really strange error value, so we can implement if ... else nicely :-) */
ONEARG;
if (v1.type != T_BOOL)
runtime( "If requires boolean 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':
debug( "No operation\n" );
break;
case P('p',','):
ONEARG;
if (what->a2.i == F_NOP || (what->a2.i != F_NONL && what->a1.p))
debug( "\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: /* FIXME (noncritical) Should print complete route along with reason to reject route */
res.type = T_RETURN;
res.val.i = what->a2.i;
return res; /* We have to return now, no more processing. */
case F_NONL:
case F_NOP:
break;
default:
bug( "unknown return type: Can't happen");
}
break;
case 'a': /* rta access */
{
struct rta *rta = (*f_rte)->attrs;
res.type = what->aux;
switch(res.type) {
case T_IP:
res.val.px.ip = * (ip_addr *) ((char *) rta + what->a2.i);
break;
case T_ENUM:
res.val.i = * ((char *) rta + what->a2.i);
break;
case T_STRING: /* Warning: this is a special case for proto attribute */
res.val.s = rta->proto->name;
break;
case T_PREFIX: /* Warning: this works only for prefix of network */
{
res.val.px.ip = (*f_rte)->net->n.prefix;
res.val.px.len = (*f_rte)->net->n.pxlen;
break;
}
default:
bug( "Invalid type for rta access (%x)", res.type );
}
}
break;
case P('a','S'):
ONEARG;
if (what->aux != v1.type)
runtime( "Attempt to set static attribute to incompatible type" );
rta_cow();
{
struct rta *rta = (*f_rte)->attrs;
switch (what->aux) {
case T_ENUM:
* ((char *) rta + what->a2.i) = v1.val.i;
break;
case T_IP:
* (ip_addr *) ((char *) rta + what->a2.i) = v1.val.px.ip;
break;
default:
bug( "Unknown type in set of static attribute" );
}
}
break;
case P('e','a'): /* Access to extended attributes */
{
eattr *e = NULL;
if (!(f_flags & FF_FORCE_TMPATTR))
e = ea_find( (*f_rte)->attrs->eattrs, what->a2.i );
if (!e)
e = ea_find( (*f_tmp_attrs), what->a2.i );
if ((!e) && (f_flags & FF_FORCE_TMPATTR))
e = ea_find( (*f_rte)->attrs->eattrs, what->a2.i );
switch (what->aux & EAF_TYPE_MASK) {
case EAF_TYPE_INT:
if (!e) {
res.type = T_VOID;
break;
}
res.type = T_INT;
res.val.i = e->u.data;
break;
case EAF_TYPE_IP_ADDRESS:
if (!e) {
res.type = T_VOID;
break;
}
res.type = T_IP;
struct adata * ad = e->u.ptr;
res.val.px.ip = * (ip_addr *) ad->data;
break;
case EAF_TYPE_AS_PATH:
if (!e) {
res.type = T_VOID;
break;
}
res.type = T_PATH;
res.val.ad = e->u.ptr;
break;
case EAF_TYPE_INT_SET:
if (!e) {
res.type = T_CLIST;
res.val.ad = adata_empty(f_pool);
break;
}
res.type = T_CLIST;
res.val.ad = e->u.ptr;
break;
default:
bug("Unknown type in e,a");
}
}
break;
case P('e','S'):
ONEARG;
{
struct ea_list *l = lp_alloc(f_pool, sizeof(struct ea_list) + sizeof(eattr));
l->next = NULL;
l->flags = EALF_SORTED;
l->count = 1;
l->attrs[0].id = what->a2.i;
l->attrs[0].flags = 0;
l->attrs[0].type = what->aux | EAF_ORIGINATED;
switch (what->aux & EAF_TYPE_MASK) {
case EAF_TYPE_INT:
if (v1.type != T_INT)
runtime( "Setting int attribute to non-int value" );
l->attrs[0].u.data = v1.val.i;
break;
case EAF_TYPE_IP_ADDRESS:
if (v1.type != T_IP)
runtime( "Setting ip attribute to non-ip value" );
int len = sizeof(ip_addr);
struct adata *ad = lp_alloc(f_pool, sizeof(struct adata) + len);
ad->length = len;
(* (ip_addr *) ad->data) = v1.val.px.ip;
break;
case EAF_TYPE_AS_PATH:
if (v1.type != T_PATH)
runtime( "Setting path attribute to non-path value" );
l->attrs[0].u.ptr = v1.val.ad;
break;
case EAF_TYPE_INT_SET:
if (v1.type != T_CLIST)
runtime( "Setting int set attribute to non-clist value" );
l->attrs[0].u.ptr = v1.val.ad;
break;
case EAF_TYPE_UNDEF:
if (v1.type != T_VOID)
runtime( "Setting void attribute to non-void value" );
l->attrs[0].u.data = 0;
break;
default: bug("Unknown type in e,S");
}
if (!(what->aux & EAF_TEMP) && (!(f_flags & FF_FORCE_TMPATTR))) {
rta_cow();
l->next = f_rta_copy->eattrs;
f_rta_copy->eattrs = l;
} else {
l->next = (*f_tmp_attrs);
(*f_tmp_attrs) = l;
}
}
break;
case 'P':
res.type = T_INT;
res.val.i = (*f_rte)->pref;
break;
case P('P','S'):
ONEARG;
if (v1.type != T_INT)
runtime( "Can't set preference to non-integer" );
*f_rte = rte_cow(*f_rte);
(*f_rte)->pref = v1.val.i;
break;
case 'L': /* Get length of */
ONEARG;
res.type = T_INT;
switch(v1.type) {
case T_PREFIX: res.val.i = v1.val.px.len; break;
case T_PATH: res.val.i = as_path_getlen(v1.val.ad); break;
default: runtime( "Prefix or path expected" );
}
break;
case P('c','p'): /* Convert prefix to ... */
ONEARG;
if (v1.type != T_PREFIX)
runtime( "Prefix expected" );
res.type = what->aux;
switch(res.type) {
/* case T_INT: res.val.i = v1.val.px.len; break; Not needed any more */
case T_IP: res.val.px.ip = v1.val.px.ip; break;
default: bug( "Unknown prefix to conversion" );
}
break;
case 'r':
ONEARG;
res = v1;
res.type |= T_RETURN;
return res;
case P('c','a'): /* CALL: this is special: if T_RETURN and returning some value, mask it out */
ONEARG;
res = interpret(what->a2.p);
if (res.type == T_RETURN)
return res;
res.type &= ~T_RETURN;
break;
case P('S','W'):
ONEARG;
{
struct f_tree *t = find_tree(what->a2.p, v1);
if (!t) {
v1.type = T_VOID;
t = find_tree(what->a2.p, v1);
if (!t) {
debug( "No else statement?\n");
break;
}
}
/* It is actually possible to have t->data NULL */
res = interpret(t->data);
if (res.type & T_RETURN)
return res;
}
break;
case P('i','M'): /* IP.MASK(val) */
TWOARGS;
if (v2.type != T_INT)
runtime( "Integer expected");
if (v1.type != T_IP)
runtime( "You can mask only IP addresses" );
{
ip_addr mask = ipa_mkmask(v2.val.i);
res.type = T_IP;
res.val.px.ip = ipa_and(mask, v1.val.px.ip);
}
break;
case 'E': /* Create empty attribute */
res.type = what->aux;
res.val.ad = adata_empty(f_pool);
break;
case P('A','p'): /* Path prepend */
TWOARGS;
if (v1.type != T_PATH)
runtime("Can't prepend to non-path");
if (v2.type != T_INT)
runtime("Can't prepend non-integer");
res.type = T_PATH;
res.val.ad = as_path_prepend(f_pool, v1.val.ad, v2.val.i);
break;
case P('C','a'): /* Community list add or delete */
TWOARGS;
if (v1.type != T_CLIST)
runtime("Can't add/delete to non-clist");
if (v2.type != T_PAIR)
runtime("Can't add/delete non-pair");
res.type = T_CLIST;
switch (what->aux) {
case 'a': res.val.ad = int_set_add(f_pool, v1.val.ad, v2.val.i); break;
case 'd': res.val.ad = int_set_del(f_pool, v1.val.ad, v2.val.i); break;
default: bug("unknown Ca operation");
}
break;
default:
bug( "Unknown instruction %d (%c)", what->code, what->code & 0xff);
}
if (what->next)
return interpret(what->next);
return res;
}
#undef ARG
#define ARG(x,y) \
if (!i_same(f1->y, f2->y)) \
return 0;
#define ONEARG ARG(v1, a1.p)
#define TWOARGS ARG(v1, a1.p) \
ARG(v2, a2.p)
#define A2_SAME if (f1->a2.i != f2->a2.i) return 0;
/*
* i_same - function that does real comparing of instruction trees, you should call filter_same from outside
*/
int
i_same(struct f_inst *f1, struct f_inst *f2)
{
if ((!!f1) != (!!f2))
return 0;
if (!f1)
return 1;
if (f1->aux != f2->aux)
return 0;
if (f1->code != f2->code)
return 0;
if (f1 == f2) /* It looks strange, but it is possible with call rewriting trickery */
return 1;
switch(f1->code) {
case ',': /* fall through */
case '+':
case '-':
case '*':
case '/':
case '|':
case '&':
case P('!','='):
case P('=','='):
case '<':
case P('<','='): TWOARGS; break;
case '!': ONEARG; break;
case '~': TWOARGS; break;
case P('d','e'): ONEARG; break;
case 's':
ARG(v2, a2.p);
{
struct symbol *s1, *s2;
s1 = f1->a1.p;
s2 = f2->a1.p;
if (strcmp(s1->name, s2->name))
return 0;
if (s1->class != s2->class)
return 0;
}
break;
case 'c':
switch (f1->aux) {
case T_PREFIX_SET:
if (!trie_same(f1->a2.p, f2->a2.p))
return 0;
case T_SET:
if (!same_tree(f1->a2.p, f2->a2.p))
return 0;
case T_STRING:
if (strcmp(f1->a2.p, f2->a2.p))
return 0;
break;
default:
A2_SAME;
}
break;
case 'C':
if (val_compare(* (struct f_val *) f1->a1.p, * (struct f_val *) f2->a1.p))
return 0;
break;
case 'p': case 'L': ONEARG; break;
case '?': TWOARGS; break;
case '0': case 'E': break;
case P('p',','): ONEARG; A2_SAME; break;
case 'P':
case 'a': A2_SAME; break;
case P('e','a'): A2_SAME; break;
case P('P','S'):
case P('a','S'):
case P('e','S'): ONEARG; A2_SAME; break;
case 'r': ONEARG; break;
case P('c','p'): ONEARG; break;
case P('c','a'): /* Call rewriting trickery to avoid exponential behaviour */
ONEARG;
if (!i_same(f1->a2.p, f2->a2.p))
return 0;
f2->a2.p = f1->a2.p;
break;
case P('S','W'): ONEARG; if (!same_tree(f1->a2.p, f2->a2.p)) return 0; break;
case P('i','M'): TWOARGS; break;
case P('A','p'): TWOARGS; break;
case P('C','a'): TWOARGS; break;
default:
bug( "Unknown instruction %d in same (%c)", f1->code, f1->code & 0xff);
}
return i_same(f1->next, f2->next);
}
/**
* f_run - external entry point to filters
* @filter: pointer to filter to run
* @tmp_attrs: where to store newly generated temporary attributes
* @rte: pointer to pointer to &rte being filtered. When route is modified, this is changed with rte_cow().
* @tmp_pool: all filter allocations go from this pool
* @flags: flags
*/
int
f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struct linpool *tmp_pool, int flags)
{
struct f_inst *inst;
struct f_val res;
DBG( "Running filter `%s'...", filter->name );
f_flags = flags;
f_tmp_attrs = tmp_attrs;
f_rte = rte;
f_rte_old = *rte;
f_rta_copy = NULL;
f_pool = tmp_pool;
inst = filter->root;
res = interpret(inst);
if (res.type != T_RETURN) {
log( L_ERR "Filter %s did not return accept nor reject. Make up your mind", filter->name);
return F_ERROR;
}
DBG( "done (%d)\n", res.val.i );
return res.val.i;
}
int
f_eval_int(struct f_inst *expr)
{
struct f_val res;
f_flags = 0;
f_tmp_attrs = NULL;
f_rte = NULL;
f_rte_old = NULL;
f_rta_copy = NULL;
f_pool = cfg_mem;
res = interpret(expr);
if (res.type != T_INT)
cf_error("Integer expression expected");
return res.val.i;
}
/**
* filter_same - compare two filters
* @new: first filter to be compared
* @old: second filter to be compared, notice that this filter is
* damaged while comparing.
*
* Returns 1 in case filters are same, otherwise 0. If there are
* underlying bugs, it will rather say 0 on same filters than say
* 1 on different.
*/
int
filter_same(struct filter *new, struct filter *old)
{
if (old == new) /* Handle FILTER_ACCEPT and FILTER_REJECT */
return 1;
if (old == FILTER_ACCEPT || old == FILTER_REJECT ||
new == FILTER_ACCEPT || new == FILTER_REJECT)
return 0;
return i_same(new->root, old->root);
}
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