mirror/labs-bird
1
0
Fork 0
mirror of https://gitlab.labs.nic.cz/labs/bird.git synced 2024-05-11 16:54:54 +00:00
Code Releases Activity

Nest: Fix several issues with pflags

Browse Source 
There were some confusion about validity and usage of pflags, which
caused incorrect usage after some flags from (now removed) protocol-
specific area were moved to pflags.

We state that pflags:

 - Are secondary data used by protocol-specific hooks
 - Can be changed on an existing route (in contrast to copy-on-write
   for primary data)
 - Are irrelevant for propagation (not propagated when changed)
 - Are specific to a routing table (not propagated by pipe)

The patch did these fixes:

 - Do not compare pflags in rte_same(), as they may keep cached values
   like BGP_REF_STALE, causing spurious propagation.

 - Initialize pflags to zero in rte_get_temp(), avoid initialization in
   protocol code, fixing at least two forgotten initializations (krt
   and one case in babel).

 - Improve documentation about pflags
This commit is contained in:
Ondrej Zajicek
2023-01-01 20:10:23 +01:00
parent 8b06a4d8af
commit 6d1ae197d1
8 changed files with 12 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
nest/rt-dev.c
View File

@ -92,7 +92,6 @@ dev_ifa_notify(struct proto *P, uint flags, struct ifa *ad)
a = rta_lookup(&a0);
e = rte_get_temp(a, src);
e->pflags = 0;
rte_update2(c, net, e, src);
}
}

21
nest/rt-table.c
View File

@ -21,11 +21,15 @@
* on the list being the best one (i.e., the one we currently use
* for routing), the order of the other ones is undetermined.
*
* The &rte contains information specific to the route (preference, protocol
* metrics, time of last modification etc.) and a pointer to a &rta structure
* (see the route attribute module for a precise explanation) holding the
* remaining route attributes which are expected to be shared by multiple
* routes in order to conserve memory.
* The &rte contains information about the route. There are net and src, which
* together forms a key identifying the route in a routing table. There is a
* pointer to a &rta structure (see the route attribute module for a precise
* explanation) holding the route attributes, which are primary data about the
* route. There are several technical fields used by routing table code (route
* id, REF_* flags), There is also the pflags field, holding protocol-specific
* flags. They are not used by routing table code, but by protocol-specific
* hooks. In contrast to route attributes, they are not primary data and their
* validity is also limited to the routing table.
*
* There are several mechanisms that allow automatic update of routes in one
* routing table (dst) as a result of changes in another routing table (src).
@ -558,10 +562,9 @@ rte_find(net *net, struct rte_src *src)
* rte_get_temp - get a temporary &rte
* @a: attributes to assign to the new route (a &rta; in case it's
* un-cached, rte_update() will create a cached copy automatically)
* @src: route source
*
* Create a temporary &rte and bind it with the attributes @a.
* Also set route preference to the default preference set for
* the protocol.
*/
rte *
rte_get_temp(rta *a, struct rte_src *src)
@ -571,6 +574,7 @@ rte_get_temp(rta *a, struct rte_src *src)
e->attrs = a;
e->id = 0;
e->flags = 0;
e->pflags = 0;
rt_lock_source(e->src = src);
return e;
}
@ -1205,10 +1209,9 @@ rte_free_quick(rte *e)
static int
rte_same(rte *x, rte *y)
{
/* rte.flags are not checked, as they are mostly internal to rtable */
/* rte.flags / rte.pflags are not checked, as they are internal to rtable */
return
x->attrs == y->attrs &&
x->pflags == y->pflags &&
x->src == y->src &&
rte_is_filtered(x) == rte_is_filtered(y);
}