From 6d1ae197d189d50e60279796441c6e74272ddc54 Mon Sep 17 00:00:00 2001 From: Ondrej Zajicek Date: Sun, 1 Jan 2023 20:10:23 +0100 Subject: Nest: Fix several issues with pflags 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 --- nest/rt-dev.c | 1 - nest/rt-table.c | 21 ++++++++++++--------- 2 files changed, 12 insertions(+), 10 deletions(-) (limited to 'nest') diff --git a/nest/rt-dev.c b/nest/rt-dev.c index 05e64fc3..7932b8b7 100644 --- a/nest/rt-dev.c +++ b/nest/rt-dev.c @@ -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); } } diff --git a/nest/rt-table.c b/nest/rt-table.c index 845b2483..e4b27814 100644 --- a/nest/rt-table.c +++ b/nest/rt-table.c @@ -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); } -- cgit v1.2.3