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mirror of https://gitlab.nic.cz/labs/bird.git synced 2024-12-22 09:41:54 +00:00

Nest: Fix bug in recursive routes with MPLS-labeled nexthops

When a recursive route with MPLS-labeled nexthop was exported to kernel
and read back, the nexthop_same() failed due to different labels_orig
field and kernel protocol reinstalled it unnecessarily.

For comparing hext hops, route cache has to distinguish ones with
different labels_orig, but KRT has to ignore that, so we need two
nexthop compare functions.

Thanks to Marcel Menzel for the bugreport.
This commit is contained in:
Ondrej Zajicek 2024-01-27 17:38:06 +01:00
parent 472be46f7a
commit f40e2bc270
3 changed files with 33 additions and 10 deletions

View File

@ -694,6 +694,9 @@ static inline size_t nexthop_size(const struct nexthop *nh)
int nexthop__same(struct nexthop *x, struct nexthop *y); /* Compare multipath nexthops */
static inline int nexthop_same(struct nexthop *x, struct nexthop *y)
{ return (x == y) || nexthop__same(x, y); }
int nexthop_equal_(struct nexthop *x, struct nexthop *y); /* Compare multipath nexthops, ignore labels_orig */
static inline int nexthop_equal(struct nexthop *x, struct nexthop *y)
{ return (x == y) || nexthop_equal_(x, y); }
struct nexthop *nexthop_merge(struct nexthop *x, struct nexthop *y, int rx, int ry, int max, linpool *lp);
struct nexthop *nexthop_sort(struct nexthop *x);
static inline void nexthop_link(struct rta *a, const struct nexthop *from)

View File

@ -185,20 +185,40 @@ nexthop_hash(struct nexthop *x)
return h;
}
int
nexthop__same(struct nexthop *x, struct nexthop *y)
static inline int
nexthop_equal_1(struct nexthop *x, struct nexthop *y)
{
for (; x && y; x = x->next, y = y->next)
{
if (!ipa_equal(x->gw, y->gw) || (x->iface != y->iface) ||
(x->flags != y->flags) || (x->weight != y->weight) ||
(x->labels_orig != y->labels_orig) || (x->labels != y->labels))
(x->labels != y->labels))
return 0;
for (int i = 0; i < x->labels; i++)
if (x->label[i] != y->label[i])
return 0;
}
return 1;
}
int
nexthop_equal_(struct nexthop *x, struct nexthop *y)
{
/* Like nexthop_same(), but ignores difference between local labels and labels from hostentry */
for (; x && y; x = x->next, y = y->next)
if (!nexthop_equal_1(x, y))
return 0;
return x == y;
}
int
nexthop__same(struct nexthop *x, struct nexthop *y)
{
for (; x && y; x = x->next, y = y->next)
if (!nexthop_equal_1(x, y) ||
(x->labels_orig != y->labels_orig))
return 0;
return x == y;
}

View File

@ -619,7 +619,7 @@ krt_same_dest(rte *k, rte *e)
return 0;
if (ka->dest == RTD_UNICAST)
return nexthop_same(&(ka->nh), &(ea->nh));
return nexthop_equal(&(ka->nh), &(ea->nh));
return 1;
}