pimd: allow mroutes with IIF in the OIL

This is specifically needed to allow pim-evpn mroutes in the MLAG setup -
(36.0.0.11, 239.1.1.100)   Iif: peerlink.4094   Oifs: uplink-1, peerlink.4094

I could have gone the other way and disabled PIM_ENFORCE_LOOPFREE_MFC but
that opens the door too wide. Relaxing the checks for mlag-specific mroutes
seemed like the safer choice.

This commit provides the infrastructure to relax checks on a per-mroute
basis.

Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>

diff --git a/pimd/pim_oil.c b/pimd/pim_oil.c
index 55d26113f7c51981729486117c00599589a6fb3d..5945bc55fd9299577ef155fb863a248e92e1ed1d 100644 (file)
--- a/pimd/pim_oil.c
+++ b/pimd/pim_oil.c
@@ -320,6 +320,7 @@ int pim_channel_add_oif(struct channel_oil *channel_oil, struct interface *oif,
 {
        struct pim_interface *pim_ifp;
        int old_ttl;
+       bool allow_iif_in_oil = false;
 
        /*
         * If we've gotten here we've gone bad, but let's
@@ -344,7 +345,14 @@ int pim_channel_add_oif(struct channel_oil *channel_oil, struct interface *oif,
          by both source and receiver attached to the same interface. See
          TODO T22.
        */
-       if (pim_ifp->mroute_vif_index == channel_oil->oil.mfcc_parent) {
+       if (channel_oil->up &&
+                       PIM_UPSTREAM_FLAG_TEST_ALLOW_IIF_IN_OIL(
+                               channel_oil->up->flags)) {
+               allow_iif_in_oil = true;
+       }
+
+       if (!allow_iif_in_oil &&
+               pim_ifp->mroute_vif_index == channel_oil->oil.mfcc_parent) {
                channel_oil->oil_inherited_rescan = 1;
                if (PIM_DEBUG_MROUTE) {
                        char group_str[INET_ADDRSTRLEN];

diff --git a/pimd/pim_upstream.h b/pimd/pim_upstream.h
index c0bd9137d4f85812b7630f832214ea9ff61ba2f7..8dc2f7635cb8e1616be1594764b261595f8b3267 100644 (file)
--- a/pimd/pim_upstream.h
+++ b/pimd/pim_upstream.h
@@ -48,6 +48,7 @@
  * value specified and preventing next-hop-tracking on the entry
  */
 #define PIM_UPSTREAM_FLAG_MASK_STATIC_IIF              (1 << 10)
+#define PIM_UPSTREAM_FLAG_MASK_ALLOW_IIF_IN_OIL        (1 << 11)
 #define PIM_UPSTREAM_FLAG_ALL 0xFFFFFFFF
 
 #define PIM_UPSTREAM_FLAG_TEST_DR_JOIN_DESIRED(flags) ((flags) & PIM_UPSTREAM_FLAG_MASK_DR_JOIN_DESIRED)
@@ -61,6 +62,7 @@
 #define PIM_UPSTREAM_FLAG_TEST_SRC_LHR(flags) ((flags) & PIM_UPSTREAM_FLAG_MASK_SRC_LHR)
 #define PIM_UPSTREAM_FLAG_TEST_DISABLE_KAT_EXPIRY(flags) ((flags) & PIM_UPSTREAM_FLAG_MASK_DISABLE_KAT_EXPIRY)
 #define PIM_UPSTREAM_FLAG_TEST_STATIC_IIF(flags) ((flags) & PIM_UPSTREAM_FLAG_MASK_STATIC_IIF)
+#define PIM_UPSTREAM_FLAG_TEST_ALLOW_IIF_IN_OIL(flags) ((flags) & PIM_UPSTREAM_FLAG_MASK_ALLOW_IIF_IN_OIL)
 
 #define PIM_UPSTREAM_FLAG_SET_DR_JOIN_DESIRED(flags) ((flags) |= PIM_UPSTREAM_FLAG_MASK_DR_JOIN_DESIRED)
 #define PIM_UPSTREAM_FLAG_SET_DR_JOIN_DESIRED_UPDATED(flags) ((flags) |= PIM_UPSTREAM_FLAG_MASK_DR_JOIN_DESIRED_UPDATED)
@@ -73,6 +75,7 @@
 #define PIM_UPSTREAM_FLAG_SET_SRC_LHR(flags) ((flags) |= PIM_UPSTREAM_FLAG_MASK_SRC_LHR)
 #define PIM_UPSTREAM_FLAG_SET_DISABLE_KAT_EXPIRY(flags) ((flags) |= PIM_UPSTREAM_FLAG_MASK_DISABLE_KAT_EXPIRY)
 #define PIM_UPSTREAM_FLAG_SET_STATIC_IIF(flags) ((flags) |= PIM_UPSTREAM_FLAG_MASK_STATIC_IIF)
+#define PIM_UPSTREAM_FLAG_SET_ALLOW_IIF_IN_OIL(flags) ((flags) |= PIM_UPSTREAM_FLAG_MASK_ALLOW_IIF_IN_OIL)
 
 #define PIM_UPSTREAM_FLAG_UNSET_DR_JOIN_DESIRED(flags) ((flags) &= ~PIM_UPSTREAM_FLAG_MASK_DR_JOIN_DESIRED)
 #define PIM_UPSTREAM_FLAG_UNSET_DR_JOIN_DESIRED_UPDATED(flags) ((flags) &= ~PIM_UPSTREAM_FLAG_MASK_DR_JOIN_DESIRED_UPDATED)
@@ -85,6 +88,7 @@
 #define PIM_UPSTREAM_FLAG_UNSET_SRC_LHR(flags) ((flags) &= ~PIM_UPSTREAM_FLAG_MASK_SRC_LHR)
 #define PIM_UPSTREAM_FLAG_UNSET_DISABLE_KAT_EXPIRY(flags) ((flags) &= ~PIM_UPSTREAM_FLAG_MASK_DISABLE_KAT_EXPIRY)
 #define PIM_UPSTREAM_FLAG_UNSET_STATIC_IIF(flags) ((flags) &= ~PIM_UPSTREAM_FLAG_MASK_STATIC_IIF)
+#define PIM_UPSTREAM_FLAG_UNSET_ALLOW_IIF_IN_OIL(flags) ((flags) &= ~PIM_UPSTREAM_FLAG_MASK_ALLOW_IIF_IN_OIL)
 
 enum pim_upstream_state {
        PIM_UPSTREAM_NOTJOINED,