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02297d3c54
bird/filter/filter.c
Maria Jan Matejka f93315c417 Config: Make the parser and lexer reentrant. 
This is part of the multithreading journey. The parser and lexer were
using loads of global variables and all of these are now packed into
struct cf_context and others.

Note that the config API has changed:

* cfg_alloc[zu]?(size) is now cf_alloc[zu]?(ctx, size)
* cf_error(msg, ...) is now cf_error(ctx, msg, ...)
* config_parse() and cli_parse() are now called differently
* there is a brand new CF_CTX section in *.Y files which participates
  in struct cf_context construction
2018-09-14 14:44:45 +02:00

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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 "lib/net.h"
#include "lib/ip.h"
#include "nest/route.h"
#include "nest/protocol.h"
#include "nest/iface.h"
#include "nest/attrs.h"
#include "conf/conf.h"
#include "conf/parser.h"
#include "filter/filter.h"
#include "filter/f-util.h"
#define CMP_ERROR 999
void (*bt_assert_hook)(int result, struct f_inst *assert);
static struct adata undef_adata; /* adata of length 0 used for undefined */
/* Special undef value for paths and clists */
static inline int
undef_value(struct f_val v)
{
return ((v.type == T_PATH) || (v.type == T_CLIST) ||
(v.type == T_ECLIST) || (v.type == T_LCLIST)) &&
(v.val.ad == &undef_adata);
}
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:
ASSERT(0);
}
p = p->next;
}
buffer_puts(buf, "=]");
}
static inline int val_is_ip4(const struct f_val v)
{ return (v.type == T_IP) && ipa_is_ip4(v.val.ip); }
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)
{
if (v1.type != v2.type) {
if (v1.type == T_VOID) /* Hack for else */
return -1;
if (v2.type == T_VOID)
return 1;
/* IP->Quad implicit conversion */
if ((v1.type == T_QUAD) && val_is_ip4(v2))
return uint_cmp(v1.val.i, ipa_to_u32(v2.val.ip));
if (val_is_ip4(v1) && (v2.type == T_QUAD))
return uint_cmp(ipa_to_u32(v1.val.ip), v2.val.i);
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:
case T_RD:
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.ip, v2.val.ip);
case T_NET:
return net_compare(v1.val.net, v2.val.net);
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);
}
}
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:
v->type = T_QUAD;
return 1;
case T_IP:
if (val_is_ip4(set->from) && val_is_ip4(set->to))
{
v->type = T_QUAD;
return 1;
}
/* Fall through */
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);
/* IP->Quad implicit conversion */
if (val_is_ip4(v1) && (v2.type == T_CLIST))
return int_set_contains(v2.val.ad, ipa_to_u32(v1.val.ip));
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_NET))
return ipa_in_netX(v1.val.ip, v2.val.net);
if ((v1.type == T_NET) && (v2.type == T_NET))
return net_in_netX(v1.val.net, v2.val.net);
if ((v1.type == T_NET) && (v2.type == T_PREFIX_SET))
return trie_match_net(v2.val.ti, v1.val.net);
if (v2.type != T_SET)
return CMP_ERROR;
/* With integrated Quad<->IP implicit conversion */
if ((v1.type == v2.val.t->from.type) ||
((v1.type == T_QUAD) && val_is_ip4(v2.val.t->from) && val_is_ip4(v2.val.t->to)))
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.ip); return;
case T_NET: buffer_print(buf, "%N", v.val.net); 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_RD: rd_format(v.val.ec, buf2, 1024); 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_eattrs;
static struct linpool *f_pool;
static struct buffer f_buf;
static int f_flags;
static inline void f_cache_eattrs(void)
{
f_eattrs = &((*f_rte)->attrs->eattrs);
}
static inline void f_rte_cow(void)
{
if (!((*f_rte)->flags & REF_COW))
return;
*f_rte = rte_do_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);
/* Re-cache the ea_list */
f_cache_eattrs();
}
static char *
val_format_str(struct f_val v) {
buffer b;
LOG_BUFFER_INIT(b);
val_format(v, &b);
return lp_strdup(f_pool, b.start);
}
static struct tbf rl_runtime_err = TBF_DEFAULT_LOG_LIMITS;
#define runtime(fmt, ...) do { \
if (!(f_flags & FF_SILENT)) \
log_rl(&rl_runtime_err, L_ERR "filters, line %d: " fmt, what->lineno, ##__VA_ARGS__); \
res.type = T_RETURN; \
res.val.i = F_ERROR; \
return res; \
} while(0)
#define ARG_ANY(n) INTERPRET(v##n, what->a##n.p)
#define ARG(n,t) ARG_ANY(n) \
if (v##n.type != t) \
runtime("Argument %d of instruction %s must be of type %02x, got %02x", \
n, f_instruction_name(what->fi_code), t, v##n.type);
#define INTERPRET(val, what_) \
val = interpret(what_); \
if (val.type & T_RETURN) \
return val;
#define ACCESS_RTE \
do { if (!f_rte) runtime("No route to access"); } while (0)
#define ACCESS_EATTRS \
do { if (!f_eattrs) f_cache_eattrs(); } 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, v3, res = { .type = T_VOID }, *vp;
unsigned u1, u2;
int i;
u32 as;
for ( ; what; what = what->next) {
res.type = T_VOID;
switch(what->fi_code) {
/* Binary operators */
case FI_ADD:
ARG(1,T_INT);
ARG(2,T_INT);
res.type = T_INT;
res.val.i = v1.val.i + v2.val.i;
break;
case FI_SUBTRACT:
ARG(1,T_INT);
ARG(2,T_INT);
res.type = T_INT;
res.val.i = v1.val.i - v2.val.i;
break;
case FI_MULTIPLY:
ARG(1,T_INT);
ARG(2,T_INT);
res.type = T_INT;
res.val.i = v1.val.i * v2.val.i;
break;
case FI_DIVIDE:
ARG(1,T_INT);
ARG(2,T_INT);
res.type = 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 FI_AND:
case FI_OR:
ARG(1,T_BOOL);
if (v1.val.i == (what->fi_code == FI_OR)) {
res.type = T_BOOL;
res.val.i = v1.val.i;
} else {
ARG(2,T_BOOL);
res = v2;
}
break;
case FI_PAIR_CONSTRUCT:
ARG(1,T_INT);
ARG(2,T_INT);
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:
{
ARG_ANY(1);
ARG(2, T_INT);
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;
}
/* IP->Quad implicit conversion */
else if (val_is_ip4(v1)) {
ipv4_used = 1; key = ipa_to_u32(v1.val.ip);
}
else
runtime("Can't operate with key of non-integer/IPv4 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:
{
ARG(1, T_INT);
ARG(2, T_INT);
ARG(3, T_INT);
res.type = T_LC;
res.val.lc = (lcomm) { v1.val.i, v2.val.i, v3.val.i };
break;
}
case FI_PATHMASK_CONSTRUCT:
{
struct f_path_mask *tt = what->a1.p, *vbegin, **vv = &vbegin;
while (tt) {
*vv = lp_alloc(f_pool, sizeof(struct f_path_mask));
if (tt->kind == PM_ASN_EXPR) {
struct f_val res;
INTERPRET(res, (struct f_inst *) tt->val);
(*vv)->kind = PM_ASN;
if (res.type != T_INT) {
runtime( "Error resolving path mask template: value not an integer" );
return (struct f_val) { .type = T_VOID };
}
(*vv)->val = res.val.i;
} else {
**vv = *tt;
}
tt = tt->next;
vv = &((*vv)->next);
}
res = (struct f_val) { .type = T_PATH_MASK, .val.path_mask = vbegin };
break;
}
/* Relational operators */
#define COMPARE(x) \
ARG_ANY(1); \
ARG_ANY(2); \
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) \
ARG_ANY(1); \
ARG_ANY(2); \
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:
ARG(1,T_BOOL);
res = v1;
res.val.i = !res.val.i;
break;
case FI_MATCH:
ARG_ANY(1);
ARG_ANY(2);
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:
ARG_ANY(1);
ARG_ANY(2);
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:
ARG_ANY(1);
res.type = T_BOOL;
res.val.i = (v1.type != T_VOID) && !undef_value(v1);
break;
case FI_TYPE:
ARG_ANY(1); /* There may be more types supporting this operation */
switch (v1.type)
{
case T_NET:
res.type = T_ENUM_NETTYPE;
res.val.i = v1.val.net->type;
break;
default:
runtime( "Can't determine type of this item" );
}
break;
case FI_IS_V4:
ARG(1, T_IP);
res.type = T_BOOL;
res.val.i = ipa_is_ip4(v1.val.ip);
break;
/* Set to indirect value, a1 = variable, a2 = value */
case FI_SET:
ARG_ANY(2);
sym = what->a1.p;
vp = sym->def;
if ((sym->class != (SYM_VARIABLE | v2.type)) && (v2.type != T_VOID))
{
/* IP->Quad implicit conversion */
if ((sym->class == (SYM_VARIABLE | T_QUAD)) && val_is_ip4(v2))
{
vp->type = T_QUAD;
vp->val.i = ipa_to_u32(v2.val.ip);
break;
}
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:
ARG_ANY(1);
val_format(v1, &f_buf);
break;
case FI_CONDITION: /* ? has really strange error value, so we can implement if ... else nicely :-) */
ARG(1, T_BOOL);
if (v1.val.i) {
ARG_ANY(2);
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:
ARG_ANY(1);
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.ip = rta->from; break;
case SA_GW: res.val.ip = rta->nh.gw; break;
case SA_NET: res.val.net = (*f_rte)->net->n.addr; 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_DEST: res.val.i = rta->dest; break;
case SA_IFNAME: res.val.s = rta->nh.iface ? rta->nh.iface->name : ""; break;
case SA_IFINDEX: res.val.i = rta->nh.iface ? rta->nh.iface->index : 0; break;
default:
bug("Invalid static attribute access (%x)", res.type);
}
}
break;
case FI_RTA_SET:
ACCESS_RTE;
ARG_ANY(1);
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.ip;
break;
case SA_GW:
{
ip_addr ip = v1.val.ip;
neighbor *n = neigh_find(rta->src->proto, ip, NULL, 0);
if (!n || (n->scope == SCOPE_HOST))
runtime( "Invalid gw address" );
rta->dest = RTD_UNICAST;
rta->nh.gw = ip;
rta->nh.iface = n->iface;
rta->nh.next = 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->nh.gw = IPA_NONE;
rta->nh.iface = NULL;
rta->nh.next = 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;
ACCESS_EATTRS;
{
u16 code = what->a2.i;
int f_type = what->aux >> 8;
eattr *e = ea_find(*f_eattrs, code);
if (!e) {
/* A special case: undefined as_path looks like empty as_path */
if ((what->aux & EAF_TYPE_MASK) == EAF_TYPE_AS_PATH) {
res.type = T_PATH;
res.val.ad = &undef_adata;
break;
}
/* The same special case for int_set */
if ((what->aux & EAF_TYPE_MASK) == EAF_TYPE_INT_SET) {
res.type = T_CLIST;
res.val.ad = &undef_adata;
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 = &undef_adata;
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 = &undef_adata;
break;
}
/* Undefined value */
res.type = T_VOID;
break;
}
switch (what->aux & EAF_TYPE_MASK) {
case EAF_TYPE_INT:
res.type = f_type;
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.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;
ACCESS_EATTRS;
ARG_ANY(1);
{
struct ea_list *l = lp_alloc(f_pool, sizeof(struct ea_list) + sizeof(eattr));
u16 code = what->a2.i;
int f_type = what->aux >> 8;
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 & 0xff) | EAF_ORIGINATED | EAF_FRESH;
switch (what->aux & EAF_TYPE_MASK) {
case EAF_TYPE_INT:
if (v1.type != f_type)
runtime( "Setting int attribute to non-int value" );
l->attrs[0].u.data = v1.val.i;
break;
case EAF_TYPE_ROUTER_ID:
/* IP->Quad implicit conversion */
if (val_is_ip4(v1)) {
l->attrs[0].u.data = ipa_to_u32(v1.val.ip);
break;
}
/* 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.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 = ea_find(*f_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");
}
f_rta_cow();
l->next = *f_eattrs;
*f_eattrs = 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;
ARG(1,T_INT);
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 */
ARG_ANY(1);
res.type = T_INT;
switch(v1.type) {
case T_NET: res.val.i = net_pxlen(v1.val.net); 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_SADR_SRC: /* Get SADR src prefix */
ARG(1, T_NET);
if (!net_is_sadr(v1.val.net))
runtime( "SADR expected" );
{
net_addr_ip6_sadr *net = (void *) v1.val.net;
net_addr *src = lp_alloc(f_pool, sizeof(net_addr_ip6));
net_fill_ip6(src, net->src_prefix, net->src_pxlen);
res.type = T_NET;
res.val.net = src;
}
break;
case FI_ROA_MAXLEN: /* Get ROA max prefix length */
ARG(1, T_NET);
if (!net_is_roa(v1.val.net))
runtime( "ROA expected" );
res.type = T_INT;
res.val.i = (v1.val.net->type == NET_ROA4) ?
((net_addr_roa4 *) v1.val.net)->max_pxlen :
((net_addr_roa6 *) v1.val.net)->max_pxlen;
break;
case FI_ROA_ASN: /* Get ROA ASN */
ARG(1, T_NET);
if (!net_is_roa(v1.val.net))
runtime( "ROA expected" );
res.type = T_INT;
res.val.i = (v1.val.net->type == NET_ROA4) ?
((net_addr_roa4 *) v1.val.net)->asn :
((net_addr_roa6 *) v1.val.net)->asn;
break;
case FI_IP: /* Convert prefix to ... */
ARG(1, T_NET);
res.type = T_IP;
res.val.ip = net_prefix(v1.val.net);
break;
case FI_ROUTE_DISTINGUISHER:
ARG(1, T_NET);
res.type = T_IP;
if (!net_is_vpn(v1.val.net))
runtime( "VPN address expected" );
res.type = T_RD;
res.val.ec = net_rd(v1.val.net);
break;
case FI_AS_PATH_FIRST: /* Get first ASN from AS PATH */
ARG(1, T_PATH);
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 */
ARG(1, T_PATH);
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 */
ARG(1, T_PATH);
res.type = T_INT;
res.val.i = as_path_get_last_nonaggregated(v1.val.ad);
break;
case FI_RETURN:
ARG_ANY(1);
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 */
ARG_ANY(1);
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:
ARG_ANY(1);
{
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 */
INTERPRET(res, t->data);
}
break;
case FI_IP_MASK: /* IP.MASK(val) */
ARG(1, T_IP);
ARG(2, T_INT);
res.type = T_IP;
res.val.ip = ipa_is_ip4(v1.val.ip) ?
ipa_from_ip4(ip4_and(ipa_to_ip4(v1.val.ip), ip4_mkmask(v2.val.i))) :
ipa_from_ip6(ip6_and(ipa_to_ip6(v1.val.ip), ip6_mkmask(v2.val.i)));
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 */
ARG(1, T_PATH);
ARG(2, T_INT);
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 */
ARG_ANY(1);
ARG_ANY(2);
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;
/* IP->Quad implicit conversion */
else if (val_is_ip4(v2))
n = ipa_to_u32(v2.val.ip);
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)
{
ARG(1, T_NET);
ARG(2, T_INT);
as = v2.val.i;
}
else
{
ACCESS_RTE;
ACCESS_EATTRS;
v1.val.net = (*f_rte)->net->n.addr;
/* 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_eattrs, EA_CODE(PROTOCOL_BGP, 0x02));
if (!e || e->type != EAF_TYPE_AS_PATH)
runtime("Missing AS_PATH attribute");
as_path_get_last(e->u.ptr, &as);
}
struct rtable *table = ((struct f_inst_roa_check *) what)->rtc->table;
if (!table)
runtime("Missing ROA table");
if (table->addr_type != NET_ROA4 && table->addr_type != NET_ROA6)
runtime("Table type must be either ROA4 or ROA6");
res.type = T_ENUM_ROA;
if (table->addr_type != (v1.val.net->type == NET_IP4 ? NET_ROA4 : NET_ROA6))
res.val.i = ROA_UNKNOWN; /* Prefix and table type mismatch */
else
res.val.i = net_roa_check(table, v1.val.net, as);
break;
case FI_FORMAT: /* Format */
ARG_ANY(1);
res.type = T_STRING;
res.val.s = val_format_str(v1);
break;
case FI_ASSERT: /* Birdtest Assert */
ARG(1, T_BOOL);
res.type = v1.type;
res.val = v1.val;
CALL(bt_assert_hook, res.val.i, what);
break;
default:
bug( "Unknown instruction %d (%c)", what->fi_code, what->fi_code & 0xff);
}}
return res;
}
#undef ARG
#undef ARG_ANY
#define ARG(n) \
if (!i_same(f1->a##n.p, f2->a##n.p)) \
return 0;
#define ONEARG ARG(1);
#define TWOARGS ONEARG; ARG(2);
#define THREEARGS TWOARGS; ARG(3);
#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_ADD: /* fall through */
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_PATHMASK_CONSTRUCT: if (!pm_same(f1->a1.p, f2->a1.p)) return 0; break;
case FI_NOT: ONEARG; break;
case FI_NOT_MATCH:
case FI_MATCH: TWOARGS; break;
case FI_DEFINED: ONEARG; break;
case FI_TYPE: ONEARG; break;
case FI_LC_CONSTRUCT:
THREEARGS;
break;
case FI_SET:
ARG(2);
{
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_ROA_MAXLEN: ONEARG; break;
case FI_ROA_ASN: ONEARG; break;
case FI_SADR_SRC: ONEARG; break;
case FI_IP: ONEARG; break;
case FI_IS_V4: ONEARG; break;
case FI_ROUTE_DISTINGUISHER: 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 results may change anyway */
if (strcmp(((struct f_inst_roa_check *) f1)->rtc->name,
((struct f_inst_roa_check *) f2)->rtc->name))
return 0;
break;
case FI_FORMAT: ONEARG; break;
case FI_ASSERT: ONEARG; 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_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 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_eattrs = NULL;
f_old_rta = NULL;
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)
{
f_rte = rte;
f_eattrs = NULL;
f_old_rta = NULL;
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);
return res;
}
struct f_val
f_eval(struct f_inst *expr, struct linpool *tmp_pool)
{
f_flags = 0;
f_eattrs = NULL;
f_rte = NULL;
f_pool = tmp_pool;
LOG_BUFFER_INIT(f_buf);
return interpret(expr);
}
uint
f_eval_int(struct f_inst *expr, struct cf_context *ctx)
{
/* Called independently in parse-time to eval expressions */
struct f_val res = f_eval(expr, ctx->cfg_mem);
if (res.type != T_INT)
cf_error(ctx, "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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