Currently, the BSD socket API is implemented in libc, translating the
API calls to character driver operations underneath. This approach
has several issues:
- it is inefficient, as most character driver operations are specific
to the socket type, thus requiring that each operation start by
bruteforcing the socket protocol family and type of the given file
descriptor using several system calls;
- it requires that libc itself be changed every time system support
for a new protocol is added;
- various parts of the libc implementations violate the asynchronous
signal safety POSIX requirements.
In order to resolve all these issues at once, the plan is to turn the
BSD socket calls into system calls, thus making the BSD socket API the
"native" ABI, removing the complexity from libc and instead letting
VFS deal with the socket calls.
The overall change is going to break all networking functionality. In
order to smoothen the transition, this patch introduces the fifteen
new BSD socket system calls, and makes libc try these first before
falling back on the old behavior. For now, the VFS implementations of
the new calls fail such that libc will always use the fallback cases.
Later on, when we introduce the actual implementation of the native
BSD socket calls, all statically linked programs will automatically
use the new ABI, thus limiting actual application breakage.
In other words: by itself, this patch does nothing, except add a bit
of transitional overhead that will disappear in the future. The
largest part of the patch is concerned with adding full support for
the new BSD socket system calls to trace(1) - this early addition has
the advantage of making system call tracing output of several socket
calls much more readable already.
Both the system call interfaces and the trace(1) support have already
been tested using code that will be committed later on.
Change-Id: I3460812be50c78be662d857f9d3d6840f3ca917f
The new MIB service implements the sysctl(2) system call which, as
we adopt more NetBSD code, is an increasingly important part of the
operating system API. The system call is implemented in the new
service rather than as part of an existing service, because it will
eventually call into many other services in order to gather data,
similar to ProcFS. Since the sysctl(2) functionality is used even
by init(8), the MIB service is added to the boot image.
MIB stands for Management Information Base, and the MIB service
should be seen as a knowledge base of management information.
The MIB service implementation of the sysctl(2) interface is fairly
complete; it incorporates support for both static and dynamic nodes
and imitates many NetBSD-specific quirks expected by userland. The
patch also adds trace(1) support for the new system call, and adds
a new test, test87, which tests the fundamental operation of the
MIB service rather thoroughly.
Change-Id: I4766b410b25e94e9cd4affb72244112c2910ff67
