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bird/filter/filter.c
Maria Jan Matejka 5a14df3950 Filter: Instruction codes named as enum 
The two-letter instructions were quite messy but they could be easily
read from memory dumps. Now GDB (since 2012) supports pretty printing
enum values and GCC checks the switch construction for missing enum
values so we are converting the nice two-byte values to enums.

Anyway, the enum still keeps the old two-byte values to be able to read
the instruction codes even without GDB from plain memory dump.
2018-03-13 16:29:33 +01:00

1810 lines
45 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 CMP_ERROR 999
static struct adata *
adata_empty(struct linpool *pool, int l)
{
struct adata *res = lp_alloc(pool, sizeof(struct adata) + l);
res->length = l;
return res;
}
static void
pm_format(struct f_path_mask *p, buffer *buf)
{
buffer_puts(buf, "[= ");
while (p)
{
switch(p->kind)
{
case PM_ASN:
buffer_print(buf, "%u ", p->val);
break;
case PM_QUESTION:
buffer_puts(buf, "? ");
break;
case PM_ASTERISK:
buffer_puts(buf, "* ");
break;
case PM_ASN_RANGE:
buffer_print(buf, "%u..%u ", p->val, p->val2);
break;
case PM_ASN_EXPR:
buffer_print(buf, "%u ", f_eval_asn((struct f_inst *) p->val));
break;
}
p = p->next;
}
buffer_puts(buf, "=]");
}
static inline int
uint_cmp(uint i1, uint i2)
{
return (int)(i1 > i2) - (int)(i1 < i2);
}
static inline int
u64_cmp(u64 i1, u64 i2)
{
return (int)(i1 > i2) - (int)(i1 < i2);
}
static inline int
lcomm_cmp(lcomm v1, lcomm v2)
{
if (v1.asn != v2.asn)
return (v1.asn > v2.asn) ? 1 : -1;
if (v1.ldp1 != v2.ldp1)
return (v1.ldp1 > v2.ldp1) ? 1 : -1;
if (v1.ldp2 != v2.ldp2)
return (v1.ldp2 > v2.ldp2) ? 1 : -1;
return 0;
}
/**
* val_compare - compare two values
* @v1: first value
* @v2: second value
*
* Compares two values and returns -1, 0, 1 on <, =, > or CMP_ERROR on
* error. Tree module relies on this giving consistent results so
* that it can be used for building balanced trees.
*/
int
val_compare(struct f_val v1, struct f_val v2)
{
int rc;
if (v1.type != v2.type) {
if (v1.type == T_VOID) /* Hack for else */
return -1;
if (v2.type == T_VOID)
return 1;
#ifndef IPV6
/* IP->Quad implicit conversion */
if ((v1.type == T_QUAD) && (v2.type == T_IP))
return uint_cmp(v1.val.i, ipa_to_u32(v2.val.px.ip));
if ((v1.type == T_IP) && (v2.type == T_QUAD))
return uint_cmp(ipa_to_u32(v1.val.px.ip), v2.val.i);
#endif
debug( "Types do not match in val_compare\n" );
return CMP_ERROR;
}
switch (v1.type) {
case T_VOID:
return 0;
case T_ENUM:
case T_INT:
case T_BOOL:
case T_PAIR:
case T_QUAD:
return uint_cmp(v1.val.i, v2.val.i);
case T_EC:
return u64_cmp(v1.val.ec, v2.val.ec);
case T_LC:
return lcomm_cmp(v1.val.lc, v2.val.lc);
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;
return uint_cmp(v1.val.px.len, v2.val.px.len);
case T_STRING:
return strcmp(v1.val.s, v2.val.s);
default:
return CMP_ERROR;
}
}
static int
pm_same(struct f_path_mask *m1, struct f_path_mask *m2)
{
while (m1 && m2)
{
if (m1->kind != m2->kind)
return 0;
if (m1->kind == PM_ASN_EXPR)
{
if (!i_same((struct f_inst *) m1->val, (struct f_inst *) m2->val))
return 0;
}
else
{
if ((m1->val != m2->val) || (m1->val2 != m2->val2))
return 0;
}
m1 = m1->next;
m2 = m2->next;
}
return !m1 && !m2;
}
/**
* val_same - compare two values
* @v1: first value
* @v2: second value
*
* Compares two values and returns 1 if they are same and 0 if not.
* Comparison of values of different types is valid and returns 0.
*/
int
val_same(struct f_val v1, struct f_val v2)
{
int rc;
rc = val_compare(v1, v2);
if (rc != CMP_ERROR)
return !rc;
if (v1.type != v2.type)
return 0;
switch (v1.type) {
case T_PATH_MASK:
return pm_same(v1.val.path_mask, v2.val.path_mask);
case T_PATH:
case T_CLIST:
case T_ECLIST:
case T_LCLIST:
return adata_same(v1.val.ad, v2.val.ad);
case T_SET:
return same_tree(v1.val.t, v2.val.t);
case T_PREFIX_SET:
return trie_same(v1.val.ti, v2.val.ti);
default:
bug("Invalid type in val_same(): %x", v1.type);
}
}
void
fprefix_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);
}
}
static int
clist_set_type(struct f_tree *set, struct f_val *v)
{
switch (set->from.type) {
case T_PAIR:
v->type = T_PAIR;
return 1;
case T_QUAD:
#ifndef IPV6
case T_IP:
#endif
v->type = T_QUAD;
return 1;
break;
default:
v->type = T_VOID;
return 0;
}
}
static inline int
eclist_set_type(struct f_tree *set)
{ return set->from.type == T_EC; }
static inline int
lclist_set_type(struct f_tree *set)
{ return set->from.type == T_LC; }
static int
clist_match_set(struct adata *clist, struct f_tree *set)
{
if (!clist)
return 0;
struct f_val v;
if (!clist_set_type(set, &v))
return CMP_ERROR;
u32 *l = (u32 *) clist->data;
u32 *end = l + clist->length/4;
while (l < end) {
v.val.i = *l++;
if (find_tree(set, v))
return 1;
}
return 0;
}
static int
eclist_match_set(struct adata *list, struct f_tree *set)
{
if (!list)
return 0;
if (!eclist_set_type(set))
return CMP_ERROR;
struct f_val v;
u32 *l = int_set_get_data(list);
int len = int_set_get_size(list);
int i;
v.type = T_EC;
for (i = 0; i < len; i += 2) {
v.val.ec = ec_get(l, i);
if (find_tree(set, v))
return 1;
}
return 0;
}
static int
lclist_match_set(struct adata *list, struct f_tree *set)
{
if (!list)
return 0;
if (!lclist_set_type(set))
return CMP_ERROR;
struct f_val v;
u32 *l = int_set_get_data(list);
int len = int_set_get_size(list);
int i;
v.type = T_LC;
for (i = 0; i < len; i += 3) {
v.val.lc = lc_get(l, i);
if (find_tree(set, v))
return 1;
}
return 0;
}
static struct adata *
clist_filter(struct linpool *pool, struct adata *list, struct f_val set, int pos)
{
if (!list)
return NULL;
int tree = (set.type == T_SET); /* 1 -> set is T_SET, 0 -> set is T_CLIST */
struct f_val v;
if (tree)
clist_set_type(set.val.t, &v);
else
v.type = T_PAIR;
int len = int_set_get_size(list);
u32 *l = int_set_get_data(list);
u32 tmp[len];
u32 *k = tmp;
u32 *end = l + len;
while (l < end) {
v.val.i = *l++;
/* pos && member(val, set) || !pos && !member(val, set), member() depends on tree */
if ((tree ? !!find_tree(set.val.t, v) : int_set_contains(set.val.ad, v.val.i)) == pos)
*k++ = v.val.i;
}
uint nl = (k - tmp) * sizeof(u32);
if (nl == list->length)
return list;
struct adata *res = adata_empty(pool, nl);
memcpy(res->data, tmp, nl);
return res;
}
static struct adata *
eclist_filter(struct linpool *pool, struct adata *list, struct f_val set, int pos)
{
if (!list)
return NULL;
int tree = (set.type == T_SET); /* 1 -> set is T_SET, 0 -> set is T_CLIST */
struct f_val v;
int len = int_set_get_size(list);
u32 *l = int_set_get_data(list);
u32 tmp[len];
u32 *k = tmp;
int i;
v.type = T_EC;
for (i = 0; i < len; i += 2) {
v.val.ec = ec_get(l, i);
/* pos && member(val, set) || !pos && !member(val, set), member() depends on tree */
if ((tree ? !!find_tree(set.val.t, v) : ec_set_contains(set.val.ad, v.val.ec)) == pos) {
*k++ = l[i];
*k++ = l[i+1];
}
}
uint nl = (k - tmp) * sizeof(u32);
if (nl == list->length)
return list;
struct adata *res = adata_empty(pool, nl);
memcpy(res->data, tmp, nl);
return res;
}
static struct adata *
lclist_filter(struct linpool *pool, struct adata *list, struct f_val set, int pos)
{
if (!list)
return NULL;
int tree = (set.type == T_SET); /* 1 -> set is T_SET, 0 -> set is T_CLIST */
struct f_val v;
int len = int_set_get_size(list);
u32 *l = int_set_get_data(list);
u32 tmp[len];
u32 *k = tmp;
int i;
v.type = T_LC;
for (i = 0; i < len; i += 3) {
v.val.lc = lc_get(l, i);
/* pos && member(val, set) || !pos && !member(val, set), member() depends on tree */
if ((tree ? !!find_tree(set.val.t, v) : lc_set_contains(set.val.ad, v.val.lc)) == pos)
k = lc_copy(k, l+i);
}
uint nl = (k - tmp) * sizeof(u32);
if (nl == list->length)
return list;
struct adata *res = adata_empty(pool, nl);
memcpy(res->data, tmp, nl);
return res;
}
/**
* val_in_range - implement |~| operator
* @v1: element
* @v2: set
*
* Checks if @v1 is element (|~| operator) of @v2.
*/
static int
val_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_INT) && (v2.type == T_PATH))
return as_path_contains(v2.val.ad, v1.val.i, 1);
if (((v1.type == T_PAIR) || (v1.type == T_QUAD)) && (v2.type == T_CLIST))
return int_set_contains(v2.val.ad, v1.val.i);
#ifndef IPV6
/* IP->Quad implicit conversion */
if ((v1.type == T_IP) && (v2.type == T_CLIST))
return int_set_contains(v2.val.ad, ipa_to_u32(v1.val.px.ip));
#endif
if ((v1.type == T_EC) && (v2.type == T_ECLIST))
return ec_set_contains(v2.val.ad, v1.val.ec);
if ((v1.type == T_LC) && (v2.type == T_LCLIST))
return lc_set_contains(v2.val.ad, v1.val.lc);
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_in_net(v1.val.px.ip, v2.val.px.ip, v2.val.px.len);
if ((v1.type == T_PREFIX) && (v2.type == T_PREFIX))
return net_in_net(v1.val.px.ip, v1.val.px.len, v2.val.px.ip, v2.val.px.len);
if ((v1.type == T_PREFIX) && (v2.type == T_PREFIX_SET))
return trie_match_fprefix(v2.val.ti, &v1.val.px);
if (v2.type != T_SET)
return CMP_ERROR;
/* With integrated Quad<->IP implicit conversion */
if ((v1.type == v2.val.t->from.type) ||
((IP_VERSION == 4) && (v1.type == T_QUAD) && (v2.val.t->from.type == T_IP)))
return !!find_tree(v2.val.t, v1);
if (v1.type == T_CLIST)
return clist_match_set(v1.val.ad, v2.val.t);
if (v1.type == T_ECLIST)
return eclist_match_set(v1.val.ad, v2.val.t);
if (v1.type == T_LCLIST)
return lclist_match_set(v1.val.ad, v2.val.t);
if (v1.type == T_PATH)
return as_path_match_set(v1.val.ad, v2.val.t);
return CMP_ERROR;
}
/*
* val_format - format filter value
*/
void
val_format(struct f_val v, buffer *buf)
{
char buf2[1024];
switch (v.type)
{
case T_VOID: buffer_puts(buf, "(void)"); return;
case T_BOOL: buffer_puts(buf, v.val.i ? "TRUE" : "FALSE"); return;
case T_INT: buffer_print(buf, "%u", v.val.i); return;
case T_STRING: buffer_print(buf, "%s", v.val.s); return;
case T_IP: buffer_print(buf, "%I", v.val.px.ip); return;
case T_PREFIX: buffer_print(buf, "%I/%d", v.val.px.ip, v.val.px.len); return;
case T_PAIR: buffer_print(buf, "(%u,%u)", v.val.i >> 16, v.val.i & 0xffff); return;
case T_QUAD: buffer_print(buf, "%R", v.val.i); return;
case T_EC: ec_format(buf2, v.val.ec); buffer_print(buf, "%s", buf2); return;
case T_LC: lc_format(buf2, v.val.lc); buffer_print(buf, "%s", buf2); return;
case T_PREFIX_SET: trie_format(v.val.ti, buf); return;
case T_SET: tree_format(v.val.t, buf); return;
case T_ENUM: buffer_print(buf, "(enum %x)%u", v.type, v.val.i); return;
case T_PATH: as_path_format(v.val.ad, buf2, 1000); buffer_print(buf, "(path %s)", buf2); return;
case T_CLIST: int_set_format(v.val.ad, 1, -1, buf2, 1000); buffer_print(buf, "(clist %s)", buf2); return;
case T_ECLIST: ec_set_format(v.val.ad, -1, buf2, 1000); buffer_print(buf, "(eclist %s)", buf2); return;
case T_LCLIST: lc_set_format(v.val.ad, -1, buf2, 1000); buffer_print(buf, "(lclist %s)", buf2); return;
case T_PATH_MASK: pm_format(v.val.path_mask, buf); return;
default: buffer_print(buf, "[unknown type %x]", v.type); return;
}
}
static struct rte **f_rte;
static struct rta *f_old_rta;
static struct ea_list **f_tmp_attrs;
static struct linpool *f_pool;
static struct buffer f_buf;
static int f_flags;
static inline void f_rte_cow(void)
{
*f_rte = rte_cow(*f_rte);
}
/*
* rta_cow - prepare rta for modification by filter
*/
static void
f_rta_cow(void)
{
if (!rta_is_cached((*f_rte)->attrs))
return;
/* Prepare to modify rte */
f_rte_cow();
/* Store old rta to free it later, it stores reference from rte_cow() */
f_old_rta = (*f_rte)->attrs;
/*
* Get shallow copy of rta. Fields eattrs and nexthops of rta are shared
* with f_old_rta (they will be copied when the cached rta will be obtained
* at the end of f_run()), also the lock of hostentry is inherited (we
* suppose hostentry is not changed by filters).
*/
(*f_rte)->attrs = rta_do_cow((*f_rte)->attrs, f_pool);
}
static struct tbf rl_runtime_err = TBF_DEFAULT_LOG_LIMITS;
#define runtime(x) do { \
if (!(f_flags & FF_SILENT)) \
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" );
#define ACCESS_RTE \
do { if (!f_rte) runtime("No route to access"); } while (0)
#define BITFIELD_MASK(what) \
(1u << (what->a2.i >> 24))
/**
* 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, *vp;
unsigned u1, u2;
int i;
u32 as;
res.type = T_VOID;
if (!what)
return res;
switch(what->fi_code) {
case FI_COMMA:
TWOARGS;
break;
/* Binary operators */
case FI_ADD:
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 FI_SUBTRACT:
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 FI_MULTIPLY:
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 FI_DIVIDE:
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;
default: runtime( "Usage of unknown type" );
}
break;
case FI_AND:
case FI_OR:
ARG(v1, a1.p);
if (v1.type != T_BOOL)
runtime( "Can't do boolean operation on non-booleans" );
if (v1.val.i == (what->fi_code == FI_OR)) {
res.type = T_BOOL;
res.val.i = v1.val.i;
break;
}
ARG(v2, a2.p);
if (v2.type != T_BOOL)
runtime( "Can't do boolean operation on non-booleans" );
res.type = T_BOOL;
res.val.i = v2.val.i;
break;
case FI_PAIR_CONSTRUCT:
TWOARGS;
if ((v1.type != T_INT) || (v2.type != T_INT))
runtime( "Can't operate with value of non-integer type in pair constructor" );
u1 = v1.val.i;
u2 = v2.val.i;
if ((u1 > 0xFFFF) || (u2 > 0xFFFF))
runtime( "Can't operate with value out of bounds in pair constructor" );
res.val.i = (u1 << 16) | u2;
res.type = T_PAIR;
break;
case FI_EC_CONSTRUCT:
{
TWOARGS;
int check, ipv4_used;
u32 key, val;
if (v1.type == T_INT) {
ipv4_used = 0; key = v1.val.i;
}
else if (v1.type == T_QUAD) {
ipv4_used = 1; key = v1.val.i;
}
#ifndef IPV6
/* IP->Quad implicit conversion */
else if (v1.type == T_IP) {
ipv4_used = 1; key = ipa_to_u32(v1.val.px.ip);
}
#endif
else
runtime("Can't operate with key of non-integer/IPv4 type in EC constructor");
if (v2.type != T_INT)
runtime("Can't operate with value of non-integer type in EC constructor");
val = v2.val.i;
/* XXXX */
res.type = T_EC;
if (what->aux == EC_GENERIC) {
check = 0; res.val.ec = ec_generic(key, val);
}
else if (ipv4_used) {
check = 1; res.val.ec = ec_ip4(what->aux, key, val);
}
else if (key < 0x10000) {
check = 0; res.val.ec = ec_as2(what->aux, key, val);
}
else {
check = 1; res.val.ec = ec_as4(what->aux, key, val);
}
if (check && (val > 0xFFFF))
runtime("Can't operate with value out of bounds in EC constructor");
break;
}
case FI_LC_CONSTRUCT:
{
TWOARGS;
/* Third argument hack */
struct f_val v3 = interpret(INST3(what).p);
if (v3.type & T_RETURN)
return v3;
if ((v1.type != T_INT) || (v2.type != T_INT) || (v3.type != T_INT))
runtime( "Can't operate with value of non-integer type in LC constructor" );
res.type = T_LC;
res.val.lc = (lcomm) { v1.val.i, v2.val.i, v3.val.i };
break;
}
/* Relational operators */
#define COMPARE(x) \
TWOARGS; \
i = val_compare(v1, v2); \
if (i==CMP_ERROR) \
runtime( "Can't compare values of incompatible types" ); \
res.type = T_BOOL; \
res.val.i = (x); \
break;
#define SAME(x) \
TWOARGS; \
i = val_same(v1, v2); \
res.type = T_BOOL; \
res.val.i = (x); \
break;
case FI_NEQ: SAME(!i);
case FI_EQ: SAME(i);
case FI_LT: COMPARE(i==-1);
case FI_LTE: COMPARE(i!=1);
case FI_NOT:
ONEARG;
if (v1.type != T_BOOL)
runtime( "Not applied to non-boolean" );
res = v1;
res.val.i = !res.val.i;
break;
case FI_MATCH:
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" );
res.val.i = !!res.val.i;
break;
case FI_NOT_MATCH:
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" );
res.val.i = !res.val.i;
break;
case FI_DEFINED:
ONEARG;
res.type = T_BOOL;
res.val.i = (v1.type != T_VOID);
break;
/* Set to indirect value, a1 = variable, a2 = value */
case FI_SET:
ARG(v2, a2.p);
sym = what->a1.p;
vp = sym->def;
if ((sym->class != (SYM_VARIABLE | v2.type)) && (v2.type != T_VOID)) {
#ifndef IPV6
/* IP->Quad implicit conversion */
if ((sym->class == (SYM_VARIABLE | T_QUAD)) && (v2.type == T_IP)) {
vp->type = T_QUAD;
vp->val.i = ipa_to_u32(v2.val.px.ip);
break;
}
#endif
runtime( "Assigning to variable of incompatible type" );
}
*vp = v2;
break;
/* some constants have value in a2, some in *a1.p, strange. */
case FI_CONSTANT: /* 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 FI_VARIABLE:
case FI_CONSTANT_INDIRECT:
res = * ((struct f_val *) what->a1.p);
break;
case FI_PRINT:
ONEARG;
val_format(v1, &f_buf);
break;
case FI_CONDITION: /* ? 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 FI_NOP:
debug( "No operation\n" );
break;
case FI_PRINT_AND_DIE:
ONEARG;
if ((what->a2.i == F_NOP || (what->a2.i != F_NONL && what->a1.p)) &&
!(f_flags & FF_SILENT))
log_commit(*L_INFO, &f_buf);
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 FI_RTA_GET: /* rta access */
{
ACCESS_RTE;
struct rta *rta = (*f_rte)->attrs;
res.type = what->aux;
switch (what->a2.i)
{
case SA_FROM: res.val.px.ip = rta->from; break;
case SA_GW: res.val.px.ip = rta->gw; break;
case SA_NET: res.val.px.ip = (*f_rte)->net->n.prefix;
res.val.px.len = (*f_rte)->net->n.pxlen; break;
case SA_PROTO: res.val.s = rta->src->proto->name; break;
case SA_SOURCE: res.val.i = rta->source; break;
case SA_SCOPE: res.val.i = rta->scope; break;
case SA_CAST: res.val.i = rta->cast; break;
case SA_DEST: res.val.i = rta->dest; break;
case SA_IFNAME: res.val.s = rta->iface ? rta->iface->name : ""; break;
case SA_IFINDEX: res.val.i = rta->iface ? rta->iface->index : 0; break;
default:
bug("Invalid static attribute access (%x)", res.type);
}
}
break;
case FI_RTA_SET:
ACCESS_RTE;
ONEARG;
if (what->aux != v1.type)
runtime( "Attempt to set static attribute to incompatible type" );
f_rta_cow();
{
struct rta *rta = (*f_rte)->attrs;
switch (what->a2.i)
{
case SA_FROM:
rta->from = v1.val.px.ip;
break;
case SA_GW:
{
ip_addr ip = v1.val.px.ip;
neighbor *n = neigh_find(rta->src->proto, &ip, 0);
if (!n || (n->scope == SCOPE_HOST))
runtime( "Invalid gw address" );
rta->dest = RTD_ROUTER;
rta->gw = ip;
rta->iface = n->iface;
rta->nexthops = NULL;
rta->hostentry = NULL;
}
break;
case SA_SCOPE:
rta->scope = v1.val.i;
break;
case SA_DEST:
i = v1.val.i;
if ((i != RTD_BLACKHOLE) && (i != RTD_UNREACHABLE) && (i != RTD_PROHIBIT))
runtime( "Destination can be changed only to blackhole, unreachable or prohibit" );
rta->dest = i;
rta->gw = IPA_NONE;
rta->iface = NULL;
rta->nexthops = NULL;
rta->hostentry = NULL;
break;
default:
bug("Invalid static attribute access (%x)", res.type);
}
}
break;
case FI_EA_GET: /* Access to extended attributes */
ACCESS_RTE;
{
eattr *e = NULL;
u16 code = what->a2.i;
if (!(f_flags & FF_FORCE_TMPATTR))
e = ea_find((*f_rte)->attrs->eattrs, code);
if (!e)
e = ea_find((*f_tmp_attrs), code);
if ((!e) && (f_flags & FF_FORCE_TMPATTR))
e = ea_find((*f_rte)->attrs->eattrs, code);
if (!e) {
/* A special case: undefined int_set looks like empty int_set */
if ((what->aux & EAF_TYPE_MASK) == EAF_TYPE_INT_SET) {
res.type = T_CLIST;
res.val.ad = adata_empty(f_pool, 0);
break;
}
/* The same special case for ec_set */
if ((what->aux & EAF_TYPE_MASK) == EAF_TYPE_EC_SET) {
res.type = T_ECLIST;
res.val.ad = adata_empty(f_pool, 0);
break;
}
/* The same special case for lc_set */
if ((what->aux & EAF_TYPE_MASK) == EAF_TYPE_LC_SET) {
res.type = T_LCLIST;
res.val.ad = adata_empty(f_pool, 0);
break;
}
/* Undefined value */
res.type = T_VOID;
break;
}
switch (what->aux & EAF_TYPE_MASK) {
case EAF_TYPE_INT:
res.type = T_INT;
res.val.i = e->u.data;
break;
case EAF_TYPE_ROUTER_ID:
res.type = T_QUAD;
res.val.i = e->u.data;
break;
case EAF_TYPE_OPAQUE:
res.type = T_ENUM_EMPTY;
res.val.i = 0;
break;
case EAF_TYPE_IP_ADDRESS:
res.type = T_IP;
struct adata * ad = e->u.ptr;
res.val.px.ip = * (ip_addr *) ad->data;
break;
case EAF_TYPE_AS_PATH:
res.type = T_PATH;
res.val.ad = e->u.ptr;
break;
case EAF_TYPE_BITFIELD:
res.type = T_BOOL;
res.val.i = !!(e->u.data & BITFIELD_MASK(what));
break;
case EAF_TYPE_INT_SET:
res.type = T_CLIST;
res.val.ad = e->u.ptr;
break;
case EAF_TYPE_EC_SET:
res.type = T_ECLIST;
res.val.ad = e->u.ptr;
break;
case EAF_TYPE_LC_SET:
res.type = T_LCLIST;
res.val.ad = e->u.ptr;
break;
case EAF_TYPE_UNDEF:
res.type = T_VOID;
break;
default:
bug("Unknown type in e,a");
}
}
break;
case FI_EA_SET:
ACCESS_RTE;
ONEARG;
{
struct ea_list *l = lp_alloc(f_pool, sizeof(struct ea_list) + sizeof(eattr));
u16 code = what->a2.i;
l->next = NULL;
l->flags = EALF_SORTED;
l->count = 1;
l->attrs[0].id = code;
l->attrs[0].flags = 0;
l->attrs[0].type = what->aux | EAF_ORIGINATED;
switch (what->aux & EAF_TYPE_MASK) {
case EAF_TYPE_INT:
// Enums are also ints, so allow them in.
if (v1.type != T_INT && (v1.type < T_ENUM_LO || v1.type > T_ENUM_HI))
runtime( "Setting int attribute to non-int value" );
l->attrs[0].u.data = v1.val.i;
break;
case EAF_TYPE_ROUTER_ID:
#ifndef IPV6
/* IP->Quad implicit conversion */
if (v1.type == T_IP) {
l->attrs[0].u.data = ipa_to_u32(v1.val.px.ip);
break;
}
#endif
/* T_INT for backward compatibility */
if ((v1.type != T_QUAD) && (v1.type != T_INT))
runtime( "Setting quad attribute to non-quad value" );
l->attrs[0].u.data = v1.val.i;
break;
case EAF_TYPE_OPAQUE:
runtime( "Setting opaque attribute is not allowed" );
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;
l->attrs[0].u.ptr = ad;
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_BITFIELD:
if (v1.type != T_BOOL)
runtime( "Setting bit in bitfield attribute to non-bool value" );
{
/* First, we have to find the old value */
eattr *e = NULL;
if (!(f_flags & FF_FORCE_TMPATTR))
e = ea_find((*f_rte)->attrs->eattrs, code);
if (!e)
e = ea_find((*f_tmp_attrs), code);
if ((!e) && (f_flags & FF_FORCE_TMPATTR))
e = ea_find((*f_rte)->attrs->eattrs, code);
u32 data = e ? e->u.data : 0;
if (v1.val.i)
l->attrs[0].u.data = data | BITFIELD_MASK(what);
else
l->attrs[0].u.data = data & ~BITFIELD_MASK(what);;
}
break;
case EAF_TYPE_INT_SET:
if (v1.type != T_CLIST)
runtime( "Setting clist attribute to non-clist value" );
l->attrs[0].u.ptr = v1.val.ad;
break;
case EAF_TYPE_EC_SET:
if (v1.type != T_ECLIST)
runtime( "Setting eclist attribute to non-eclist value" );
l->attrs[0].u.ptr = v1.val.ad;
break;
case EAF_TYPE_LC_SET:
if (v1.type != T_LCLIST)
runtime( "Setting lclist attribute to non-lclist 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))) {
f_rta_cow();
l->next = (*f_rte)->attrs->eattrs;
(*f_rte)->attrs->eattrs = l;
} else {
l->next = (*f_tmp_attrs);
(*f_tmp_attrs) = l;
}
}
break;
case FI_PREF_GET:
ACCESS_RTE;
res.type = T_INT;
res.val.i = (*f_rte)->pref;
break;
case FI_PREF_SET:
ACCESS_RTE;
ONEARG;
if (v1.type != T_INT)
runtime( "Can't set preference to non-integer" );
if (v1.val.i > 0xFFFF)
runtime( "Setting preference value out of bounds" );
f_rte_cow();
(*f_rte)->pref = v1.val.i;
break;
case FI_LENGTH: /* 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;
case T_CLIST: res.val.i = int_set_get_size(v1.val.ad); break;
case T_ECLIST: res.val.i = ec_set_get_size(v1.val.ad); break;
case T_LCLIST: res.val.i = lc_set_get_size(v1.val.ad); break;
default: runtime( "Prefix, path, clist or eclist expected" );
}
break;
case FI_IP: /* 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 FI_AS_PATH_FIRST: /* Get first ASN from AS PATH */
ONEARG;
if (v1.type != T_PATH)
runtime( "AS path expected" );
as = 0;
as_path_get_first(v1.val.ad, &as);
res.type = T_INT;
res.val.i = as;
break;
case FI_AS_PATH_LAST: /* Get last ASN from AS PATH */
ONEARG;
if (v1.type != T_PATH)
runtime( "AS path expected" );
as = 0;
as_path_get_last(v1.val.ad, &as);
res.type = T_INT;
res.val.i = as;
break;
case FI_AS_PATH_LAST_NAG: /* Get last ASN from non-aggregated part of AS PATH */
ONEARG;
if (v1.type != T_PATH)
runtime( "AS path expected" );
res.type = T_INT;
res.val.i = as_path_get_last_nonaggregated(v1.val.ad);
break;
case FI_RETURN:
ONEARG;
res = v1;
res.type |= T_RETURN;
return res;
case FI_CALL: /* 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 FI_CLEAR_LOCAL_VARS: /* Clear local variables */
for (sym = what->a1.p; sym != NULL; sym = sym->aux2)
((struct f_val *) sym->def)->type = T_VOID;
break;
case FI_SWITCH:
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 FI_IP_MASK: /* 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 FI_EMPTY: /* Create empty attribute */
res.type = what->aux;
res.val.ad = adata_empty(f_pool, 0);
break;
case FI_PATH_PREPEND: /* 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 FI_CLIST_ADD_DEL: /* (Extended) Community list add or delete */
TWOARGS;
if (v1.type == T_PATH)
{
struct f_tree *set = NULL;
u32 key = 0;
int pos;
if (v2.type == T_INT)
key = v2.val.i;
else if ((v2.type == T_SET) && (v2.val.t->from.type == T_INT))
set = v2.val.t;
else
runtime("Can't delete non-integer (set)");
switch (what->aux)
{
case 'a': runtime("Can't add to path");
case 'd': pos = 0; break;
case 'f': pos = 1; break;
default: bug("unknown Ca operation");
}
if (pos && !set)
runtime("Can't filter integer");
res.type = T_PATH;
res.val.ad = as_path_filter(f_pool, v1.val.ad, set, key, pos);
}
else if (v1.type == T_CLIST)
{
/* Community (or cluster) list */
struct f_val dummy;
int arg_set = 0;
uint n = 0;
if ((v2.type == T_PAIR) || (v2.type == T_QUAD))
n = v2.val.i;
#ifndef IPV6
/* IP->Quad implicit conversion */
else if (v2.type == T_IP)
n = ipa_to_u32(v2.val.px.ip);
#endif
else if ((v2.type == T_SET) && clist_set_type(v2.val.t, &dummy))
arg_set = 1;
else if (v2.type == T_CLIST)
arg_set = 2;
else
runtime("Can't add/delete non-pair");
res.type = T_CLIST;
switch (what->aux)
{
case 'a':
if (arg_set == 1)
runtime("Can't add set");
else if (!arg_set)
res.val.ad = int_set_add(f_pool, v1.val.ad, n);
else
res.val.ad = int_set_union(f_pool, v1.val.ad, v2.val.ad);
break;
case 'd':
if (!arg_set)
res.val.ad = int_set_del(f_pool, v1.val.ad, n);
else
res.val.ad = clist_filter(f_pool, v1.val.ad, v2, 0);
break;
case 'f':
if (!arg_set)
runtime("Can't filter pair");
res.val.ad = clist_filter(f_pool, v1.val.ad, v2, 1);
break;
default:
bug("unknown Ca operation");
}
}
else if (v1.type == T_ECLIST)
{
/* Extended community list */
int arg_set = 0;
/* v2.val is either EC or EC-set */
if ((v2.type == T_SET) && eclist_set_type(v2.val.t))
arg_set = 1;
else if (v2.type == T_ECLIST)
arg_set = 2;
else if (v2.type != T_EC)
runtime("Can't add/delete non-ec");
res.type = T_ECLIST;
switch (what->aux)
{
case 'a':
if (arg_set == 1)
runtime("Can't add set");
else if (!arg_set)
res.val.ad = ec_set_add(f_pool, v1.val.ad, v2.val.ec);
else
res.val.ad = ec_set_union(f_pool, v1.val.ad, v2.val.ad);
break;
case 'd':
if (!arg_set)
res.val.ad = ec_set_del(f_pool, v1.val.ad, v2.val.ec);
else
res.val.ad = eclist_filter(f_pool, v1.val.ad, v2, 0);
break;
case 'f':
if (!arg_set)
runtime("Can't filter ec");
res.val.ad = eclist_filter(f_pool, v1.val.ad, v2, 1);
break;
default:
bug("unknown Ca operation");
}
}
else if (v1.type == T_LCLIST)
{
/* Large community list */
int arg_set = 0;
/* v2.val is either LC or LC-set */
if ((v2.type == T_SET) && lclist_set_type(v2.val.t))
arg_set = 1;
else if (v2.type == T_LCLIST)
arg_set = 2;
else if (v2.type != T_LC)
runtime("Can't add/delete non-lc");
res.type = T_LCLIST;
switch (what->aux)
{
case 'a':
if (arg_set == 1)
runtime("Can't add set");
else if (!arg_set)
res.val.ad = lc_set_add(f_pool, v1.val.ad, v2.val.lc);
else
res.val.ad = lc_set_union(f_pool, v1.val.ad, v2.val.ad);
break;
case 'd':
if (!arg_set)
res.val.ad = lc_set_del(f_pool, v1.val.ad, v2.val.lc);
else
res.val.ad = lclist_filter(f_pool, v1.val.ad, v2, 0);
break;
case 'f':
if (!arg_set)
runtime("Can't filter lc");
res.val.ad = lclist_filter(f_pool, v1.val.ad, v2, 1);
break;
default:
bug("unknown Ca operation");
}
}
else
runtime("Can't add/delete to non-[e|l]clist");
break;
case FI_ROA_CHECK: /* ROA Check */
if (what->arg1)
{
TWOARGS;
if ((v1.type != T_PREFIX) || (v2.type != T_INT))
runtime("Invalid argument to roa_check()");
as = v2.val.i;
}
else
{
ACCESS_RTE;
v1.val.px.ip = (*f_rte)->net->n.prefix;
v1.val.px.len = (*f_rte)->net->n.pxlen;
/* We ignore temporary attributes, probably not a problem here */
/* 0x02 is a value of BA_AS_PATH, we don't want to include BGP headers */
eattr *e = ea_find((*f_rte)->attrs->eattrs, EA_CODE(EAP_BGP, 0x02));
if (!e || e->type != EAF_TYPE_AS_PATH)
runtime("Missing AS_PATH attribute");
as_path_get_last(e->u.ptr, &as);
}
struct roa_table_config *rtc = ((struct f_inst_roa_check *) what)->rtc;
if (!rtc->table)
runtime("Missing ROA table");
res.type = T_ENUM_ROA;
res.val.i = roa_check(rtc->table, v1.val.px.ip, v1.val.px.len, as);
break;
default:
bug( "Unknown instruction %d (%c)", what->fi_code, what->fi_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->fi_code != f2->fi_code)
return 0;
if (f1 == f2) /* It looks strange, but it is possible with call rewriting trickery */
return 1;
switch(f1->fi_code) {
case FI_COMMA: /* fall through */
case FI_ADD:
case FI_SUBTRACT:
case FI_MULTIPLY:
case FI_DIVIDE:
case FI_OR:
case FI_AND:
case FI_PAIR_CONSTRUCT:
case FI_EC_CONSTRUCT:
case FI_NEQ:
case FI_EQ:
case FI_LT:
case FI_LTE: TWOARGS; break;
case FI_NOT: ONEARG; break;
case FI_NOT_MATCH:
case FI_MATCH: TWOARGS; break;
case FI_DEFINED: ONEARG; break;
case FI_LC_CONSTRUCT:
TWOARGS;
if (!i_same(INST3(f1).p, INST3(f2).p))
return 0;
break;
case FI_SET:
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 FI_CONSTANT:
switch (f1->aux) {
case T_PREFIX_SET:
if (!trie_same(f1->a2.p, f2->a2.p))
return 0;
break;
case T_SET:
if (!same_tree(f1->a2.p, f2->a2.p))
return 0;
break;
case T_STRING:
if (strcmp(f1->a2.p, f2->a2.p))
return 0;
break;
default:
A2_SAME;
}
break;
case FI_CONSTANT_INDIRECT:
if (!val_same(* (struct f_val *) f1->a1.p, * (struct f_val *) f2->a1.p))
return 0;
break;
case FI_VARIABLE:
if (strcmp((char *) f1->a2.p, (char *) f2->a2.p))
return 0;
break;
case FI_PRINT: case FI_LENGTH: ONEARG; break;
case FI_CONDITION: TWOARGS; break;
case FI_NOP: case FI_EMPTY: break;
case FI_PRINT_AND_DIE: ONEARG; A2_SAME; break;
case FI_PREF_GET:
case FI_RTA_GET: A2_SAME; break;
case FI_EA_GET: A2_SAME; break;
case FI_PREF_SET:
case FI_RTA_SET:
case FI_EA_SET: ONEARG; A2_SAME; break;
case FI_RETURN: ONEARG; break;
case FI_IP: ONEARG; break;
case FI_CALL: /* 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 FI_CLEAR_LOCAL_VARS: break; /* internal instruction */
case FI_SWITCH: ONEARG; if (!same_tree(f1->a2.p, f2->a2.p)) return 0; break;
case FI_IP_MASK: TWOARGS; break;
case FI_PATH_PREPEND: TWOARGS; break;
case FI_CLIST_ADD_DEL: TWOARGS; break;
case FI_AS_PATH_FIRST:
case FI_AS_PATH_LAST:
case FI_AS_PATH_LAST_NAG: ONEARG; break;
case FI_ROA_CHECK:
TWOARGS;
/* Does not really make sense - ROA check resuls may change anyway */
if (strcmp(((struct f_inst_roa_check *) f1)->rtc->name,
((struct f_inst_roa_check *) f2)->rtc->name))
return 0;
break;
default:
bug( "Unknown instruction %d in same (%c)", f1->fi_code, f1->fi_code & 0xff);
}
return i_same(f1->next, f2->next);
}
/**
* f_run - run a filter for a route
* @filter: filter to run
* @rte: route being filtered, may be modified
* @tmp_attrs: temporary attributes, prepared by caller or generated by f_run()
* @tmp_pool: all filter allocations go from this pool
* @flags: flags
*
* If filter needs to modify the route, there are several
* posibilities. @rte might be read-only (with REF_COW flag), in that
* case rw copy is obtained by rte_cow() and @rte is replaced. If
* @rte is originally rw, it may be directly modified (and it is never
* copied).
*
* The returned rte may reuse the (possibly cached, cloned) rta, or
* (if rta was modificied) contains a modified uncached rta, which
* uses parts allocated from @tmp_pool and parts shared from original
* rta. There is one exception - if @rte is rw but contains a cached
* rta and that is modified, rta in returned rte is also cached.
*
* Ownership of cached rtas is consistent with rte, i.e.
* if a new rte is returned, it has its own clone of cached rta
* (and cached rta of read-only source rte is intact), if rte is
* modified in place, old cached rta is possibly freed.
*/
int
f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struct linpool *tmp_pool, int flags)
{
if (filter == FILTER_ACCEPT)
return F_ACCEPT;
if (filter == FILTER_REJECT)
return F_REJECT;
int rte_cow = ((*rte)->flags & REF_COW);
DBG( "Running filter `%s'...", filter->name );
f_rte = rte;
f_old_rta = NULL;
f_tmp_attrs = tmp_attrs;
f_pool = tmp_pool;
f_flags = flags;
LOG_BUFFER_INIT(f_buf);
struct f_val res = interpret(filter->root);
if (f_old_rta) {
/*
* Cached rta was modified and f_rte contains now an uncached one,
* sharing some part with the cached one. The cached rta should
* be freed (if rte was originally COW, f_old_rta is a clone
* obtained during rte_cow()).
*
* This also implements the exception mentioned in f_run()
* description. The reason for this is that rta reuses parts of
* f_old_rta, and these may be freed during rta_free(f_old_rta).
* This is not the problem if rte was COW, because original rte
* also holds the same rta.
*/
if (!rte_cow)
(*f_rte)->attrs = rta_lookup((*f_rte)->attrs);
rta_free(f_old_rta);
}
if (res.type != T_RETURN) {
if (!(f_flags & FF_SILENT))
log_rl(&rl_runtime_err, L_ERR "Filter %s did not return accept nor reject. Make up your mind", filter->name);
return F_ERROR;
}
DBG( "done (%u)\n", res.val.i );
return res.val.i;
}
/* TODO: perhaps we could integrate f_eval(), f_eval_rte() and f_run() */
struct f_val
f_eval_rte(struct f_inst *expr, struct rte **rte, struct linpool *tmp_pool)
{
struct ea_list *tmp_attrs = NULL;
f_rte = rte;
f_old_rta = NULL;
f_tmp_attrs = &tmp_attrs;
f_pool = tmp_pool;
f_flags = 0;
LOG_BUFFER_INIT(f_buf);
/* Note that in this function we assume that rte->attrs is private / uncached */
struct f_val res = interpret(expr);
/* Hack to include EAF_TEMP attributes to the main list */
(*rte)->attrs->eattrs = ea_append(tmp_attrs, (*rte)->attrs->eattrs);
return res;
}
struct f_val
f_eval(struct f_inst *expr, struct linpool *tmp_pool)
{
f_flags = 0;
f_tmp_attrs = NULL;
f_rte = NULL;
f_pool = tmp_pool;
LOG_BUFFER_INIT(f_buf);
return interpret(expr);
}
uint
f_eval_int(struct f_inst *expr)
{
/* Called independently in parse-time to eval expressions */
struct f_val res = f_eval(expr, cfg_mem);
if (res.type != T_INT)
cf_error("Integer expression expected");
return res.val.i;
}
u32
f_eval_asn(struct f_inst *expr)
{
/* Called as a part of another interpret call, therefore no log_reset() */
struct f_val res = interpret(expr);
return (res.type == T_INT) ? res.val.i : 0;
}
/**
* 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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