A generic application might select netdev_default instead of
gnrc_netdev_default to pull in the default network interface.
So pull in gnrc_netif if netdev_default is selected with GNRC.
If we get a large (e.g. /62) prefix from e.g. DHCPv6, we can split it
into subnets automatically to configure downstream interfaces.
This allows for automatic configuration of daisy-chained nodes or
nodes connected in a tree topology.
To enable the feature, a new pseudo-module `gnrc_ipv6_auto_subnets` is
provided.
If the fib contains a route to a subnet via another host, it can not
be on-link.
Consider fib entries when deciding whether an address is on-link.
If a route via another host is a stronger match than an on-link
prefix, the address must be off-link.
Initialize addr with 0 first.
Otherwise if prefix is < 64 there will be random bits of stack memory
in the bits of the address that are neither touched by ipv6_addr_set_aiid()
nor ipv6_addr_init_prefix().
Sending a RA with ltime = 0 does not get us added to the default router
list, but the options (and therefore the RIO) are still parsed.
This even appears to work with Linux as a receiver.
When the default router was removed or could not be added, `dr` will
be NULL.
In this case, don't cease sending router solicitations - we still don't
have a default router.
dhcpv6_client_prefix_valid_until returned the valid timestamp
this fixes it according to the documentation given in
/sys/include/net/dhcpv6/client.h
to return seconds left
Consider the following: A node tries to forward a packet to another
host for which it does not know the route yet. It assumes it to be
on-link and starts a neighbor solicitation, putting the node address
in the destinatio cache.
Later the route is known (via a second hop) but the host is still in
the NIB.
The result is that gnrc_ipv6_nib_get_next_hop_l2addr() ends up in the
"nib: %s is in NC or on-link, start address resolution" case and does
not attempt to resolve the route.
This results in the host remaining unreachable even though now a route
is present.
Prefix delegation used to be the only supported feature of our DHCPv6
client, but by now it also supports MUD, DNS recursive name servers and
IA_NA is on the horizon. So it makes sense to make IA_PD an optional
module like all those other features are as well.
The `udp` command is a valuable debugging tool that is also useful
outside of the gnrc_networking example.
To enable easy sending of udp messages in other applications during
development, move the `udp` command to the shell module and introduce
the `gnrc_udp_cmd` pseudo-module to enable it.
This commit implements uplink redundancy in GNRC LoRaWAN. Uplink
redundancy is used to retransmit unconfirmed uplink frames. The
retransmission stops when either a downlink message is received or the
number of uplink retransmissions is reached.
This functionality doesn't affect confirmed uplinks.
If a node has two interfaces A with 2001:16b8:45b5:9af8:5884:3bff:fe4f:a903
and B with 2001:16b8:45b5:9afa:5884:3bff:fe4f:a902 and receives a neighbor
solicitation on A for an address configured on interface B, answer the neighbor
solicitation instead of bailing out with
> Target address 2001:16b8:45b5:9afa:5884:3bff:fe4f:a902 is not assigned
> to the local interface
Make gnrc_netif_create() block until the interface is created and
registered.
This avoids a race condition where after calling gnrc_netif_init_devs()
not all interfaces are available yet when iterating through the list
of interfaces with gnrc_netif_iter().
A lot of things break if `GNRC_NETIF_FLAGS_HAS_L2ADDR` is not set.
In order to handle router advertisements and auto-configureation,
generate a faux l2 address based on the netdev ID.
This option was unused before, honor it to make it possible to start
with router advertisements disabled and enable them at run time.
The defaults remain unchanged by that.
This commit removes the dependency to xtimer and RIOT messages.
This step is required to use other sources of events (e.g event_queue)
and timers (RTT)
If we switch the interface in gnrc_ipv6_nib_get_next_hop_l2addr()
we must also re-get the nib entry from the 'proper' interface.
Otherwise we will always find the host unreachable on the 'wrong'
interface.
Consider the following configuration:
nib prefix
2001:16b8:4569:88fc::/62 dev #7 expires 7081 sec deprecates 3481 sec
2001:16b8:4569:88fe::/63 dev #6
If `_on_link()` stops at the first match, a packet received from #7 with a
destination in the downstream subnet in #6 would always be sent back via #7
if this happens to be the first entry in the list.
Instead, consider all prefixes and return the one that is the closest match.
When two threads use `gnrc_ipv6_nib_get_next_hop_l2addr()` to determine
a next hop (e.g. when there is both an IPv6 sender and a 6LoWPAN
fragment forwarder), a race condition may happen, where one thread
acquires the NIB and the other acquires the network interface resulting
in a deadlock. By releasing the NIB (if acquired) before trying to
acquire the network interface and re-acquiring the NIB after the network
interface is acquired, this is fixed.
