So far only a single blocking API could be handled simultaneously, due to
epoll_ctl(..., EPOLL_CTL_ADD, ...) returning -EEXIST when same file
descriptor was added twice.
Follow 'man epoll' advice about using dup() syscall to create a duplicate
file descriptor, which can be used with different events masks. Use such
duplicate for each blocking API except ioctl() (for handling Zephyr poll()
syscall).
Signed-off-by: Marcin Niestroj <m.niestroj@emb.dev>
zsock_poll_internal() iterates through all fds to call
ZFD_IOCTL_POLL_UPDATE on them. In cases when -EAGAIN is returned from one
of such syscalls (which happens for example for TLS sockets when in the
middle of a TLS handshake) whole fds array is iterated once again. This
means that ZFD_IOCTL_POLL_UPDATE can be called more than once for a single
preceding ZFD_IOCTL_POLL_PREPARE operation. This resulted in error in
nsos_adapt_poll_remove() call, which was not intended to be called twice.
In case ZFD_IOCTL_POLL_UPDATE is called second time, update 'revents' just
by calling poll() syscall on the host (Linux) side with 0 timeout.
Signed-off-by: Marcin Niestroj <m.niestroj@emb.dev>
Use NSI_HW_EVENT() in order to periodically check for events in host
sockets. Whenever there is a socket event ready to be processed by Zephyr,
raise native_sim (newly introduced) CPU interrupt, so that Zephyr driver
can signal readiness with k_poll().
Maintain a list of Zephyr poll() executions in Zephyr context. Iterate
through them whenever there is some event to be processed.
Signed-off-by: Marcin Niestroj <m.niestroj@emb.dev>
Add driver for 'native_sim' target that implements offloaded socket
networking by the use of host networking stack and wrapped BSD sockets API.
This driver has following advantages over existing networking drivers for
emulated platforms that are already in tree:
* no TUN/TAP use means that no additional setup is required on the host
side:
* possible to use it within unpriviledged Docker containers, either for
development or in CI
* possibility to use and test offloaded sockets
(CONFIG_NET_SOCKETS_OFFLOAD=y) with emulated target, which allows
to increase tests coverage of this feature, without requirement of using
hardware
Native Simulator host libc has different error codes than embedded libc
used by Zephyr. Convert between those.
Signed-off-by: Marcin Niestroj <m.niestroj@emb.dev>
