In order to receive a connect notification from SCTP socket,
poll/select event must be used instead of a write notification via
io_uring completion event.
Once the connect notification has been received, subsequent write
notifications via io_uring are used.
Change-Id: I4eca9ea72beb0d6ea4d44cce81ed620033f07270
Related: OS#5751
Add support osmo_io operations resembling sendmsg() and recvmsg() socket
operations. This is what will enable the implementation of higher-layer
functions like equivalents of sctp_recvmsg() and sctp_send() in
libosmo-netif and/or other users.
Change-Id: I89eb519b22d21011d61a7855b2364bc3c295df82
Related: OS#5751
This relocation is necessary as the backend (osmo_io_fd or
osmo_io_uring) requires a different approach in handling connect
notifications. As a result, a function call has been introduced to
struct iofd_backend_ops.
In a subsequent patch, the process for the osmo_io_uring backend will
be modified to handle SCTP connect notifications using poll/select.
If connect notification is requested using poll/select, the file
descriptior must be registered to osmo_fd, using osmo_fd_register. If
read / write notification is requested by application, the file
descriptior must be registered also. A flag is used prevent calling
osmo_fd_register / osmo_fd_unregister multiple times, which would cause
a crash.
Change-Id: I905ec85210570aff8addadfc9603335d04eb057a
Related: OS#5751