From b016b552a6169e0e2f6c3a8d10429f9fe63b4add Mon Sep 17 00:00:00 2001 From: anlan_cs Date: Tue, 30 May 2023 16:45:45 +0800 Subject: [PATCH] pimd: Fix missing pimreg interface `pimregX` of specific vrf can be deleted from kernel after this vrf is deleted. However, then `pimdregX` will never come back to kernel after adding it ( the same vrf ) back. That is to say, it exists only in daemon, but not in kernel. The root cause is this `pimregX` is not really deleted for its special usage, and `pim_if_create_pimreg()` wants reusing it. I have tried 4 solutions: 1. Remove the `configured` flag of `pimregX`, allow its deletion. A few timers still use `pimregX` after its deletion. So, not adopted. 2. Remove `pimregX` by vrf hook in `pim_instance_terminate()`. It has no vrf id there. So, not adopted. 3. Reuse `pimregX` in `pim_if_create_pimreg()`. If `pim->regiface->info` is true, then reuse old `pimregX` and only call `pim_if_add_vif()` to install it into kernel. But at that time, it maybe is in default VRF. The `pim_zebra_interface_set_master()` doesn't work at that time because it shouldn't wait there for its changing into correct VRF. So, not adopted. 4. Not reuse it. If `pim->regiface->info` is true, there must have been pim instance with VRF deleted and created before. Actually delele old one in `pim_if_create_pimreg()`, then recreate new one. Finally, this PR adopted the fourth solution. Fixes #13454 Signed-off-by: anlan_cs --- pimd/pim_iface.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/pimd/pim_iface.c b/pimd/pim_iface.c index b1beb45630..660acbe5e6 100644 --- a/pimd/pim_iface.c +++ b/pimd/pim_iface.c @@ -1495,9 +1495,16 @@ void pim_if_create_pimreg(struct pim_instance *pim) pim->vrf->name); pim->regiface->ifindex = PIM_OIF_PIM_REGISTER_VIF; - if (!pim->regiface->info) - pim_if_new(pim->regiface, false, false, true, - false /*vxlan_term*/); + /* + * The pimreg interface might has been removed from + * kerenl with the VRF's deletion. It must be + * recreated, so delete the old one first. + */ + if (pim->regiface->info) + pim_if_delete(pim->regiface); + + pim_if_new(pim->regiface, false, false, true, + false /*vxlan_term*/); /* * On vrf moves we delete the interface if there