pimd: try to reinstall MFC when we get NOCACHE

Whether due to a pimd bug, some expiry, or someone just deleting MFC
entries, when we're in NOCACHE we *know* there's no MFC entry.  Add an
install call to make sure pimd's MFC view aligns with the actual kernel
MFC.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

diff --git a/pimd/pim_mroute.c b/pimd/pim_mroute.c
index 4fecc2a80bd96e764598ac061e70f53921de661b..05e4b5da913590f8acacf555ce01656802f2458a 100644 (file)
--- a/pimd/pim_mroute.c
+++ b/pimd/pim_mroute.c
@@ -34,6 +34,8 @@
 #include "pim_msg.h"
 
 static void mroute_read_on(struct pim_instance *pim);
+static int pim_upstream_mroute_update(struct channel_oil *c_oil,
+                                     const char *name);
 
 int pim_mroute_set(struct pim_instance *pim, int enable)
 {
@@ -147,6 +149,7 @@ int pim_mroute_msg_nocache(int fd, struct interface *ifp, const kernmsg *msg)
        struct pim_upstream *up;
        struct pim_rpf *rpg;
        pim_sgaddr sg;
+       bool desync = false;
 
        memset(&sg, 0, sizeof(sg));
        sg.src = msg->msg_im_src;
@@ -219,6 +222,12 @@ int pim_mroute_msg_nocache(int fd, struct interface *ifp, const kernmsg *msg)
 
        up = pim_upstream_find_or_add(&sg, ifp, PIM_UPSTREAM_FLAG_MASK_FHR,
                                      __func__);
+       if (up->channel_oil->installed) {
+               zlog_warn(
+                       "%s: NOCACHE for %pSG, MFC entry disappeared - reinstalling",
+                       ifp->name, &sg);
+               desync = true;
+       }
 
        /*
         * I moved this debug till after the actual add because
@@ -242,6 +251,11 @@ int pim_mroute_msg_nocache(int fd, struct interface *ifp, const kernmsg *msg)
        /* if we have receiver, inherit from parent */
        pim_upstream_inherited_olist_decide(pim_ifp->pim, up);
 
+       /* we just got NOCACHE from the kernel, so...  MFC is not in the
+        * kernel for some reason or another.  Try installing again.
+        */
+       if (desync)
+               pim_upstream_mroute_update(up->channel_oil, __func__);
        return 0;
 }