pimd: Create pimreg interface when we start any interface config

When you configure interface configuration without explicitly
configuring pim on that interface, we were not creating the pimreg
interface and as such we would crash in an attempted register
since the pimreg device is non-existent.

The crash is this:
==8823== Invalid read of size 8
==8823==    at 0x468614: pim_channel_add_oif (pim_oil.c:392)
==8823==    by 0x46D0F1: pim_register_join (pim_register.c:61)
==8823==    by 0x449AB3: pim_mroute_msg_nocache (pim_mroute.c:242)
==8823==    by 0x449AB3: pim_mroute_msg (pim_mroute.c:661)
==8823==    by 0x449AB3: mroute_read (pim_mroute.c:707)
==8823==    by 0x4FC0676: thread_call (thread.c:1549)
==8823==    by 0x4EF3A2F: frr_run (libfrr.c:1064)
==8823==    by 0x40DCB5: main (pim_main.c:162)
==8823==  Address 0xc8 is not stack'd, malloc'd or (recently) free'd

pim_register_join calls pim_channel_add_oif with:

	pim_channel_add_oif(up->channel_oil, pim->regiface,
			    PIM_OIF_FLAG_PROTO_PIM);

We just need to make srue pim->regiface exists once we start configuring
pim.

Fixes: #5358
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

diff --git a/pimd/pim_cmd.c b/pimd/pim_cmd.c
index e5686a94f44bc34c3a51162343cb2c718c2c0543..e7e0573968282e36d4873bed6a23d68a33bd043d 100644 (file)
--- a/pimd/pim_cmd.c
+++ b/pimd/pim_cmd.c
@@ -7381,12 +7381,14 @@ static int pim_cmd_interface_add(struct interface *ifp)
        struct pim_interface *pim_ifp = ifp->info;
 
        if (!pim_ifp)
-               (void)pim_if_new(ifp, false, true, false, false);
+               pim_ifp = pim_if_new(ifp, false, true, false, false);
        else
                PIM_IF_DO_PIM(pim_ifp->options);
 
        pim_if_addr_add_all(ifp);
        pim_if_membership_refresh(ifp);
+
+       pim_if_create_pimreg(pim_ifp->pim);
        return 1;
 }