The TAP-Win32 device is not a socket, and select() under Windows only works
with sockets. Tinc used a separate thread to read from the TAP-Win32 device,
and passed this via a local socket to the main thread which could then select()
from it. We now use a global mutex, which is only unlocked when the main thread
is waiting for select(), to allow the TAP reader thread to process packets
directly.
When chrooted, we either need to force-initialize resolver
and/or nsswitch somehow (no clean way) or resolve all the
names we want before entering chroot jail. The latter
looks cleaner, easier and it is actually safe because
we still don't talk with the remote nodes there, only
initiating outgoing connections.
This option can be set to low, normal or high. On UNIX flavours, this changes
the nice value of the process by +10, 0 and -10 respectively. On Windows, it
sets the priority to BELOW_NORMAL_PRIORITY_CLASS, NORMAL_PRIORITY_CLASS and
HIGH_PRIORITY_CLASS respectively.
A high priority might help to reduce latency and packet loss on the VPN.
Change formatting of error messages about failed syscalls
to be the same as in other places in tincd.
Also suggest a change in "$foo not supported on this platform"
message as it's now used more than once.
mlock()/mlockall() are not persistent across fork(), and it's
done in parent process before daemon() which does fork(). So
basically, current --mlock does nothing useful.
Move mlock() to after detach() so it works for child process
instead of parent.
Also, check if the platform supports mlock right when processing
options (since else we'll have to die after startup, not at
startup, the error message will be in log only).
Add two options, -R/--chroot and -U/--user=user, to chroot to the
config directory (where tinc.conf is located) and to perform
setuid to the user specified, after all the initialization is done.
What's left is handling of pid file since we can't remove it anymore.
In preparation of chroot/setuid operations, split out call to
try_outgoing_connections() from setup_network_connections()
(which was the last call in setup_network_connections()).
This is because dropping privileges should be done in-between
setup_network_connections() and try_outgoing_connections().
This patch renames setup_network_connections() to setup_network()
and moves call to try_outgoing_connections() into main routine.
No functional changes.
When generating an RSA keypair, the new public and private keys are appended to
files. However, when OpenSSL reads keys it only reads the first in a file, not
the last. Instead of printing an easily ignored warning, tinc now disables old
keys when appending new ones.
When no session key is known for a node, or when it is doing PMTU discovery but
no MTU probes have returned yet, packets are sent via TCP. Some logic is added
to make sure intermediate nodes continue forwarding via TCP. The per-node
packet queue is now no longer necessary and has been removed.
