zebra: free unhashable (dup) NHEs via ID table cleanup

Free unhashable (duplicate NHEs from the kernel) via ID table
cleanup. Since the NHE ID hash table contains extra entries,
that's the one we need to be calling zebra_nhg_hash_free()
on, otherwise we will never free the unhashable NHEs.

This was found via a memleak:

==1478713== HEAP SUMMARY:
==1478713==     in use at exit: 10,267 bytes in 46 blocks
==1478713==   total heap usage: 76,810 allocs, 76,764 frees, 3,901,237 bytes allocated
==1478713==
==1478713== 208 (88 direct, 120 indirect) bytes in 1 blocks are definitely lost in loss record 35 of 41
==1478713==    at 0x483BB1A: calloc (vg_replace_malloc.c:762)
==1478713==    by 0x48E35E8: qcalloc (memory.c:110)
==1478713==    by 0x451CCB: zebra_nhg_alloc (zebra_nhg.c:369)
==1478713==    by 0x453DE3: zebra_nhg_copy (zebra_nhg.c:379)
==1478713==    by 0x452670: nhg_ctx_process_new (zebra_nhg.c:1143)
==1478713==    by 0x4523A8: nhg_ctx_process (zebra_nhg.c:1234)
==1478713==    by 0x452A2D: zebra_nhg_kernel_find (zebra_nhg.c:1294)
==1478713==    by 0x4326E0: netlink_nexthop_change (rt_netlink.c:2433)
==1478713==    by 0x427320: netlink_parse_info (kernel_netlink.c:945)
==1478713==    by 0x432DAD: netlink_nexthop_read (rt_netlink.c:2488)
==1478713==    by 0x41B600: interface_list (if_netlink.c:1486)
==1478713==    by 0x457275: zebra_ns_enable (zebra_ns.c:127)

Repro with:
ip next add id 1 blackhole
ip next add id 2 blackhole

valgrind /usr/lib/frr/zebra

Signed-off-by: Stephen Worley <sworley@cumulusnetworks.com>
(cherry picked from commit c25c3ea57a3dcd3b36d86ba76dd34961bcb662f0)

diff --git a/zebra/zebra_router.c b/zebra/zebra_router.c
index a891ffb76a2453c226039c7cb9e1f3a3ea3653c2..ea2b6752b39c71c5be46a506ade82f2f586cb5e6 100644 (file)
--- a/zebra/zebra_router.c
+++ b/zebra/zebra_router.c
@@ -223,10 +223,11 @@ void zebra_router_terminate(void)
        zebra_vxlan_disable();
        zebra_mlag_terminate();
 
-       hash_clean(zrouter.nhgs, zebra_nhg_hash_free);
-       hash_free(zrouter.nhgs);
-       hash_clean(zrouter.nhgs_id, NULL);
+       /* Free NHE in ID table only since it has unhashable entries as well */
+       hash_clean(zrouter.nhgs_id, zebra_nhg_hash_free);
        hash_free(zrouter.nhgs_id);
+       hash_clean(zrouter.nhgs, NULL);
+       hash_free(zrouter.nhgs);
 
        hash_clean(zrouter.rules_hash, zebra_pbr_rules_free);
        hash_free(zrouter.rules_hash);