bird/filter/data.c
Ondrej Zajicek (work) ec430a7fee Nest: Implement BGP path mask loop operator
Implement regex-like '+' operator in BGP path masks to match previous
path mask item multiple times. This is useful as ASNs may appear
multiple times in paths due to path prepending for traffic engineering
purposes.
2020-05-18 16:25:08 +02:00

592 lines
14 KiB
C

/*
* Filters: utility functions
*
* (c) 1998 Pavel Machek <pavel@ucw.cz>
* (c) 2019 Maria Matejka <mq@jmq.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*
*/
#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 "filter/filter.h"
#include "filter/f-inst.h"
#include "filter/data.h"
static const char * const f_type_str[] = {
[T_VOID] = "void",
[T_INT] = "int",
[T_BOOL] = "bool",
[T_PAIR] = "pair",
[T_QUAD] = "quad",
[T_ENUM_RTS] = "enum rts",
[T_ENUM_BGP_ORIGIN] = "enum bgp_origin",
[T_ENUM_SCOPE] = "enum scope",
[T_ENUM_RTC] = "enum rtc",
[T_ENUM_RTD] = "enum rtd",
[T_ENUM_ROA] = "enum roa",
[T_ENUM_NETTYPE] = "enum nettype",
[T_ENUM_RA_PREFERENCE] = "enum ra_preference",
[T_ENUM_AF] = "enum af",
[T_IP] = "ip",
[T_NET] = "prefix",
[T_STRING] = "string",
[T_PATH_MASK] = "bgpmask",
[T_PATH] = "bgppath",
[T_CLIST] = "clist",
[T_EC] = "ec",
[T_ECLIST] = "eclist",
[T_LC] = "lc",
[T_LCLIST] = "lclist",
[T_RD] = "rd",
};
const char *
f_type_name(enum f_type t)
{
if (t < ARRAY_SIZE(f_type_str))
return f_type_str[t] ?: "?";
if ((t == T_SET) || (t == T_PREFIX_SET))
return "set";
return "?";
}
const struct f_val f_const_empty_path = {
.type = T_PATH,
.val.ad = &null_adata,
}, f_const_empty_clist = {
.type = T_CLIST,
.val.ad = &null_adata,
}, f_const_empty_eclist = {
.type = T_ECLIST,
.val.ad = &null_adata,
}, f_const_empty_lclist = {
.type = T_LCLIST,
.val.ad = &null_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(const struct f_path_mask *p, buffer *buf)
{
int loop = 0;
buffer_puts(buf, "[= ");
for (uint i=0; i<p->len; i++)
{
switch(p->item[i].kind)
{
case PM_ASN:
buffer_print(buf, "%u ", p->item[i].asn);
break;
case PM_QUESTION:
buffer_puts(buf, "? ");
break;
case PM_ASTERISK:
buffer_puts(buf, "* ");
break;
case PM_LOOP:
loop = 1;
break;
case PM_ASN_RANGE:
buffer_print(buf, "%u..%u ", p->item[i].from, p->item[i].to);
break;
case PM_ASN_EXPR:
ASSERT(0);
}
if (loop && (p->item[i].kind != PM_LOOP))
{
buffer_puts(buf, "+ ");
loop = 0;
}
}
buffer_puts(buf, "=]");
}
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 F_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(const struct f_val *v1, const 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 F_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 F_CMP_ERROR;
}
}
static inline int
pmi_same(const struct f_path_mask_item *mi1, const struct f_path_mask_item *mi2)
{
if (mi1->kind != mi2->kind)
return 0;
switch (mi1->kind) {
case PM_ASN:
if (mi1->asn != mi2->asn)
return 0;
break;
case PM_ASN_EXPR:
if (!f_same(mi1->expr, mi2->expr))
return 0;
break;
case PM_ASN_RANGE:
if (mi1->from != mi2->from)
return 0;
if (mi1->to != mi2->to)
return 0;
break;
}
return 1;
}
static int
pm_same(const struct f_path_mask *m1, const struct f_path_mask *m2)
{
if (m1->len != m2->len)
for (uint i=0; i<m1->len; i++)
if (!pmi_same(&(m1->item[i]), &(m2->item[i])))
return 0;
return 1;
}
/**
* 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(const struct f_val *v1, const struct f_val *v2)
{
int rc;
rc = val_compare(v1, v2);
if (rc != F_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_MASK_ITEM:
return pmi_same(&(v1->val.pmi), &(v2->val.pmi));
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);
}
}
int
clist_set_type(const 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 int
clist_match_set(const struct adata *clist, const struct f_tree *set)
{
if (!clist)
return 0;
struct f_val v;
if (!clist_set_type(set, &v))
return F_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(const struct adata *list, const struct f_tree *set)
{
if (!list)
return 0;
if (!eclist_set_type(set))
return F_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(const struct adata *list, const struct f_tree *set)
{
if (!list)
return 0;
if (!lclist_set_type(set))
return F_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;
}
const struct adata *
clist_filter(struct linpool *pool, const struct adata *list, const 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;
}
const struct adata *
eclist_filter(struct linpool *pool, const struct adata *list, const 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;
}
const struct adata *
lclist_filter(struct linpool *pool, const struct adata *list, const 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.
*/
int
val_in_range(const struct f_val *v1, const 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 F_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 F_CMP_ERROR;
}
/*
* val_format - format filter value
*/
void
val_format(const 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;
}
}
char *
val_format_str(struct linpool *lp, const struct f_val *v) {
buffer b;
LOG_BUFFER_INIT(b);
val_format(v, &b);
return lp_strdup(lp, b.start);
}
static char val_dump_buffer[1024];
const char *
val_dump(const struct f_val *v) {
static buffer b = {
.start = val_dump_buffer,
.end = val_dump_buffer + 1024,
};
b.pos = b.start;
val_format(v, &b);
return val_dump_buffer;
}