From bbe598df214486db57a0fd72a3c9875c0dfc2006 Mon Sep 17 00:00:00 2001 From: Sarita Patra Date: Fri, 22 Feb 2019 01:38:41 -0800 Subject: [PATCH] pimd: added comments for upstream and channel_oil new values MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Added comments which explains the new values for existing fields and new fields in the upstream and channel_oil data structure. Following are the summary of the behaviour change in PIM code. Scenario 1 : RP doesn’t exist/RP not reachable Event: Join received Current behaviour: No upstream gets created Changed behaviour: Upstream data structure created with below info upstream_addr: INADDR_ANY channel_oil iif: MAXVIF channel_oil is_valid: FALSE (flag introduced to indicate if this entry is valid to get installed in hardware) RPF details: Not valid Join state: NOT_JOINED Kernal installed: FALSE Scenario 2: Dummy upstream exists Event: RP configured Current Behaviour: upstream address updated for the dummy upstream created. Changed Behaviour: upstream_addr: RP address channel_oil iif: MAXVIF channel_oil is_valid: FALSE RPF details: only RP address updated Join state: NOT_JOINED Kernel installed: FALSE Scenario 3: Dummy upstream exists Event: RP becomes reachable Current Behaviour: Update channel oil, rpf details in the upstream and install in hardware Changed Behaviour: upstream_addr: RP Adress channel_oil iif: MAXVIF channel_oil is_valid: FALSE RPF details: RPF details updated via NHT callback Join state: JOINED Kernel installed: TRUE Scenario 4: MRoute exists Event: RP gets deleted Current behaviour: Nothing got updated in him upstream and channel oil, join timer still runs. Mroute still exists in kernel. Changed behaviour: upstream_addr: INADDR_ANY channel_oil iif: MAXVIF channel_oil is_valid: FALSE RPF details: Not valid Join state: NOT_JOINED (also sent prune towards deleted RPF nbr) Kernel installed: FALSE Scenario 5: MRoute Exists Event: RP unreachable Current behaviour: Nothing got updated in him upstream and channel oil, join timer still runs. Mroute sdeleted from kernel. Changed behaviour: upstream_addr: RP address channel_oil iif: MAXVIF channel_oil is_valid: FALSE RPF details: only RP address updated Join state: NOT_JOINED (also sent prune towards deleted RPF nbr) Kernel installed: FALSE Scenario 6: Mroute exists Event: Better RP configured with precise group range & reachable. Current behaviour: No effect on existing route. Changed behaviour: Upstream address: Better RP RPF interface: towards the better RP Join state: JOINED (Send a prune towards the old RP and send a join towards the better RP) Scenario 7: Mroute exists Event: RP deleted and another RP with broad group range fits this group & reachable Current behaviour: No effect on current behaviour Changed behaviour: Upstream address: next available RP RPF interface: towards the next available RP Join state: JOINED (Send a prune towards the old RP and send a join towards the better RP) Signed-off-by: Sarita Patra --- pimd/pim_oil.h | 20 ++++++++++++++++++++ pimd/pim_upstream.h | 24 ++++++++++++++++++++++-- 2 files changed, 42 insertions(+), 2 deletions(-) diff --git a/pimd/pim_oil.h b/pimd/pim_oil.h index 94d3840e98..fef414cc85 100644 --- a/pimd/pim_oil.h +++ b/pimd/pim_oil.h @@ -64,12 +64,32 @@ struct channel_counts { Each channel_oil.oil is used to control an (S,G) entry in the Kernel Multicast Forwarding Cache. + + There is a case when we create a channel_oil but don't install in the kernel + + Case where (S, G) entry not installed in the kernel: + FRR receives IGMP/PIM (*, G) join and RP is not configured or + not-reachable, then create a channel_oil for the group G with the incoming + interface(channel_oil.oil.mfcc_parent) as invalid i.e "MAXVIF" and populate + the outgoing interface where join is received. Keep this entry in the stack, + but don't install in the kernel(channel_oil.installed = 0). + + Case where (S, G) entry installed in the kernel: + When RP is configured and is reachable for the group G, and receiving a + join if channel_oil is already present then populate the incoming interface + and install the entry in the kernel, if channel_oil not present, then create + a new_channel oil(channel_oil.installed = 1). + + is_valid: indicate if this entry is valid to get installed in kernel. + installed: indicate if this entry is installed in the kernel. + */ struct channel_oil { struct pim_instance *pim; struct mfcctl oil; + bool is_valid; int installed; int oil_inherited_rescan; int oil_size; diff --git a/pimd/pim_upstream.h b/pimd/pim_upstream.h index f44b95c811..70e70140d1 100644 --- a/pimd/pim_upstream.h +++ b/pimd/pim_upstream.h @@ -88,10 +88,30 @@ enum pim_upstream_sptbit { /* Upstream (S,G) channel in Joined state - (S,G) in the "Not Joined" state is not represented - See RFC 4601: 4.5.7. Sending (S,G) Join/Prune Message + + upstream_addr : Who we are talking to. + For (*, G), upstream_addr is RP address or INADDR_ANY(if RP not configured) + For (S, G), upstream_addr is source address + + rpf: contains the nexthop information to whom we are talking to. + + join_state: JOINED/NOTJOINED + + In the case when FRR receives IGMP/PIM (*, G) join for group G and RP is not + configured, then create a pim_upstream with the below information. + pim_upstream->upstream address: INADDR_ANY + pim_upstream->rpf: Unknown + pim_upstream->state: NOTJOINED + + When a new RP gets configured for G, find the corresponding pim upstream (*,G) + entries and update the upstream address as new RP address if it the better one + for the group G. + + When RP becomes reachable, populate the nexthop information in + pim_upstream->rpf and update the state to JOINED. + */ struct pim_upstream { struct pim_upstream *parent; -- 2.39.5