colin/NetworkManager
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

platform: ensure cache consistency for routes by workaround missing kernel event

Browse Source 
Consider:

  unshare -n
  ip link add d0 type dummy
  ip link add d1 type dummy
  ip link set d0 up
  ip link set d1 up
  ip addr add 192.168.100.5/24 dev d0
  ip addr add 192.168.101.5/24 dev d1

  ip route add 192.168.200.0/24 via 192.168.100.1
  ip monitor &
  ip route change 192.168.200.0/24 via 192.168.101.1
  #prints 192.168.200.0/24 via 192.168.101.1 dev d1
  ip route show
  #192.168.100.0/24 dev d0  proto kernel  scope link  src 192.168.100.5
  #192.168.101.0/24 dev d1  proto kernel  scope link  src 192.168.101.5
  #192.168.200.0/24 via 192.168.101.1 dev d1

Note that `ip route change` replaced the exising route. "Replaced" in this
case means: the previous route on device "d0" got removed and a new route
on "d1" was added. However, kernel only sent one RTM_NEWROUTE event, no
RTM_DELROUTE that notifies about this change.

We need to workaround that by re-synching the routes when we receive a
RTM_NEWROUTE notification.
This commit is contained in:
Thomas Haller
2016-04-10 11:21:50 +02:00
parent 20618901dd
commit f8b2cadfc1
3 changed files with 174 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

46
src/platform/nm-linux-platform.c
View File

@@ -3169,7 +3169,7 @@ cache_prune_candidates_prune (NMPlatform *platform)
static void
cache_pre_hook (NMPCache *cache, const NMPObject *old, const NMPObject *new, NMPCacheOpsType ops_type, gpointer user_data)
{
NMPlatform *platform = NM_PLATFORM (user_data);
NMPlatform *platform = user_data;
NMLinuxPlatformPrivate *priv = NM_LINUX_PLATFORM_GET_PRIVATE (platform);
const NMPClass *klass;
char str_buf[sizeof (_nm_utils_to_string_buffer)];
@@ -3181,6 +3181,7 @@ cache_pre_hook (NMPCache *cache, const NMPObject *old, const NMPObject *new, NMP
nm_assert (ops_type != NMP_CACHE_OPS_REMOVED || (new == NULL && NMP_OBJECT_IS_VALID (old) && nmp_object_is_alive (old)));
nm_assert (ops_type != NMP_CACHE_OPS_UPDATED || (NMP_OBJECT_IS_VALID (old) && nmp_object_is_alive (old) && NMP_OBJECT_IS_VALID (new) && nmp_object_is_alive (new)));
nm_assert (new == NULL || old == NULL || nmp_object_id_equal (new, old));
nm_assert (!old || !new || NMP_OBJECT_GET_CLASS (old) == NMP_OBJECT_GET_CLASS (new));
klass = old ? NMP_OBJECT_GET_CLASS (old) : NMP_OBJECT_GET_CLASS (new);
@@ -3387,11 +3388,49 @@ cache_pre_hook (NMPCache *cache, const NMPObject *old, const NMPObject *new, NMP
NULL);
}
}
break;
default:
break;
}
}
static void
cache_post (NMPlatform *platform,
struct nlmsghdr *msghdr,
NMPCacheOpsType cache_op,
NMPObject *obj,
NMPObject *obj_cache)
{
NMLinuxPlatformPrivate *priv = NM_LINUX_PLATFORM_GET_PRIVATE (platform);
nm_assert (NMP_OBJECT_IS_VALID (obj));
nm_assert (!obj_cache || nmp_object_id_equal (obj, obj_cache));
if (msghdr->nlmsg_type == RTM_NEWROUTE) {
DelayedActionType action_type;
action_type = NMP_OBJECT_GET_TYPE (obj) == NMP_OBJECT_TYPE_IP4_ROUTE
? DELAYED_ACTION_TYPE_REFRESH_ALL_IP4_ROUTES
: DELAYED_ACTION_TYPE_REFRESH_ALL_IP6_ROUTES;
if ( !delayed_action_refresh_all_in_progress (platform, action_type)
&& nmp_cache_find_other_route_for_same_destination (priv->cache, obj)) {
/* via `iproute route change` the user can update an existing route which effectively
* means that a new object (with a different ID) comes into existance, replacing the
* old on. In other words, as the ID of the object changes, we really see a new
* object with the old one deleted.
* However, kernel decides not to send a RTM_DELROUTE event for that.
*
* To hack around that, check if the update leaves us with multiple routes for the
* same network/plen,metric part. In that case, we cannot do better then requesting
* all routes anew, which sucks.
*
* One mitigation to avoid a dump is only to request a new dump, if we are not in
* the middle of an ongoing dump (delayed_action_refresh_all_in_progress). */
delayed_action_schedule (platform, action_type, NULL);
}
}
}
/******************************************************************/
static int
@@ -3528,8 +3567,6 @@ event_seq_check_refresh_all (NMPlatform *platform, guint32 seq_number)
DelayedActionWaitForNlResponseData *data;
guint i;
(void) delayed_action_refresh_all_in_progress;
if (NM_IN_SET (seq_number, 0, priv->nlh_seq_last_seen))
return;
@@ -3635,6 +3672,9 @@ event_valid_msg (NMPlatform *platform, struct nl_msg *msg, gboolean handle_event
case RTM_NEWADDR:
case RTM_NEWROUTE:
cache_op = nmp_cache_update_netlink (priv->cache, obj, &obj_cache, &was_visible, cache_pre_hook, platform);
cache_post (platform, msghdr, cache_op, obj, obj_cache);
do_emit_signal (platform, obj_cache, cache_op, was_visible);
break;