lldpd: fix chassis copy

When a chassis is already known, we copy the new one over the old one
and keep the old one. With the addition of management addresses as a
list, the copy was incorrect. We fix it. This is kludgy. A better way
would be to use marshaling but marshaling is not able to do inplace
copy and it is not able to restore full list (previous pointer is not
restored).

diff --git a/src/lldpd.c b/src/lldpd.c
index f91e6a159a6c2608906089691e0bdb318279572d..8144da458d734031e507ba316dcd3e99781b8017 100644 (file)
--- a/src/lldpd.c
+++ b/src/lldpd.c
@@ -373,24 +373,43 @@ lldpd_cleanup(struct lldpd *cfg)
        }
 }
 
-/* Update chassis `ochassis' with values from `chassis'. */
+/* Update chassis `ochassis' with values from `chassis'. The later one is not
+   expected to be part of a list! It will also be wiped from memory. */
 static void
-lldpd_update_chassis(struct lldpd_chassis *ochassis,
-    const struct lldpd_chassis *chassis) {
-       TAILQ_ENTRY(lldpd_chassis) entries;
+lldpd_move_chassis(struct lldpd_chassis *ochassis,
+    struct lldpd_chassis *chassis) {
        /* We want to keep refcount, index and list stuff from the current
         * chassis */
+       TAILQ_ENTRY(lldpd_chassis) entries;
        int refcount = ochassis->c_refcount;
        int index = ochassis->c_index;
        memcpy(&entries, &ochassis->c_entries,
            sizeof(entries));
-       /* Make the copy */
        lldpd_chassis_cleanup(ochassis, 0);
+
+       /* Make the copy. */
+       /* WARNING: this is a kludgy hack, we need in-place copy and cannot use
+        * marshaling. */
        memcpy(ochassis, chassis, sizeof(struct lldpd_chassis));
+       TAILQ_INIT(&ochassis->c_mgmt);
+
+       /* Copy of management addresses */
+       struct lldpd_mgmt *mgmt, *mgmt_next;
+       for (mgmt = TAILQ_FIRST(&chassis->c_mgmt);
+            mgmt != NULL;
+            mgmt = mgmt_next) {
+               mgmt_next = TAILQ_NEXT(mgmt, m_entries);
+               TAILQ_REMOVE(&chassis->c_mgmt, mgmt, m_entries);
+               TAILQ_INSERT_TAIL(&ochassis->c_mgmt, mgmt, m_entries);
+       }
+
        /* Restore saved values */
        ochassis->c_refcount = refcount;
        ochassis->c_index = index;
        memcpy(&ochassis->c_entries, &entries, sizeof(entries));
+
+       /* Get rid of the new chassis */
+       free(chassis);
 }
 
 static int
@@ -495,8 +514,7 @@ lldpd_decode(struct lldpd *cfg, char *frame, int s,
                free(oport);
        }
        if (ochassis) {
-               lldpd_update_chassis(ochassis, chassis);
-               free(chassis);
+               lldpd_move_chassis(ochassis, chassis);
                chassis = ochassis;
        } else {
                /* Chassis not known, add it */

diff --git a/src/lldpd.h b/src/lldpd.h
index 0ecf4e936d83dc1a3c3fd14330293d5141c3e115..90f3d47b83a6f493a83ee8dfaa8d07447bbf408f 100644 (file)
--- a/src/lldpd.h
+++ b/src/lldpd.h
@@ -231,6 +231,8 @@ struct lldpd_chassis {
 #endif
 
 };
+/* WARNING: any change to this structure should also be reflected into
+   `lldpd_copy_chassis()` which is not using marshaling. */
 MARSHAL_BEGIN(lldpd_chassis)
 MARSHAL_TQE(lldpd_chassis, c_entries)
 MARSHAL_FSTR(lldpd_chassis, c_id, c_id_len)