By pre-multiplying the input arrays with a linear phase the
fast multiplication via FFT and inverse FFT computes a negative
wrapped convolution corresponding to a modulus of x^n+1.
poll() may return POLLHUP or POLLNVAL for given file descriptors. To handle
these properly, we signal them to the EXCEPT watcher state, if registered. If
not, we call the read/write callbacks, so they can properly fail when trying
to read from or write to the file descriptor.
Replace relevant uses of select() by poll(). poll(2) avoids the difficulties
we have with more than 1024 open file descriptors, and seems to be fairly
portable.
Fixes#757.
If multiple sockets are ready, we previously preferred the IPv4 non-NAT socket
over others. To handle all with equal priority, use a round-robin selection.
Instead of allocating MTU-sized buffers for each packet, read to a stack buffer
and copy to an allocation of the actual packet size. While it requires an
additional copy on non-Apple platforms, this should make allocation more
efficient for small packets.
Introduces options to enable concurrent Netlink queries. While this does not
make much sense on vanilla Linux, this can help on third party stacks to
increase throughput if longer latencies are to expect. Netlink message
retransmission can be optionally enabled if transmission is unreliable.
Non-socket based IKE bypass policies and other tweaks bring better compatibility
to third party stacks using Netlink.
As some backends over unreliable transport do not cache response messages,
retransmissions due the loss of responses perform the operation again. Add an
option to ignore some errors arising from such duplicate operations.
Note: This approach can't distinguish between real EXIST/NOTFOUND errors
and packet failures, and therefore is a source of race conditions and can't
detect any of these errors actually happening. Therefore that behavior is
disabled by default, and can be enabled with the ignore_retransmit_errors
strongswan.conf option.
To properly distinguish between real and retransmission errors, a Netlink
backend should implement retransmission detection using sequence numbers.
The socket based IKE bypass policies are usually superior, but not supported
on all networking stacks. The port based variant uses global policies for the
UDP ports we have IKE sockets for.
As under vanilla Linux the kernel can't handle parallel dump queries and returns
EBUSY, it makes not much sense to use them. Disable parallel queries by default
to basically restore original behavior, improving performance.
Besides that it can improve throughput, it avoids a deadlock situation. If
all threads are busy, watcher will invoke the FD notification for NEWADDR
events itself. If the lock is held, it gets locked up. As watcher is not
dispatching anymore, it can't signal Netlink socket send() completion, and
the send() operation does not return and keeps the lock.
If the kernel can't execute a Netlink query because a different query is already
active, it returns EBUSY. As this can happen now as we support parallel queries,
retry on this error condition.
Instead of locking the socket exclusively to wait for replies, use watcher
to wait for and read in responses asynchronously. This allows multiple parallel
Netlink queries, which can significantly improve performance if the kernel
Netlink layer has longer latencies and supports parallel queries.
For vanilla Linux, parallel queries don't make much sense, as it usually returns
EBUSY for the relevant dump requests. This requires a retry, and in the end
makes queries more expensive under high load.
Instead of checking the Netlink message sequence number to detect multi-part
messages, this code now relies on the NLM_F_MULTI flag to detect them. This
has previously been avoided (by 1d51abb7). It is unclear if the flag did not
work correctly on very old Linux kernels, or if the flag was not used
appropriately by strongSwan. The flag seems to work just fine back to 2.6.18,
which is a kernel still in use by RedHat/CentOS 5.
If no offline leases are available for the current client and assigning online
leases is disabled, and if all IPs of the pool have already been assigned to
clients we look for offline leases that previously were assigned to other
clients.
In case the current client has online leases the previous code would
replace the existing mapping entry and besides resulting in a memory leak
the online leases would be lost forever (even if the client later releases
the addresses). If this happens repeatedly the number of available addresses
would decrease even though the total number of online and offline leases seen
in `ipsec leases` would indicate that there are free addresses available.
Fixes#764.
This adds support for EAP-TLS authentication on Android.
EAP-only authentication is currently not allowed because the AAA identity
is not configurable, so to prevent anyone with a valid certificate from
impersonating the AAA server and thus the gateway, we authenticate the
gateway (like we do with other authentication methods).
Also, it's currently not possible to select a specific CA certificate to
authenticate the AAA server certificate, so it either must be issued by the
same CA as that of the gateway or automatic CA certificate selection must
be used.
Andreas Steffen