This patch adds the implementation of the BSD socket system calls
which have been introduced in an earlier patch. At the same time, it
adds support for communication with socket drivers, using a new
"socket device" (SDEV_) protocol. These two parts, implemented in
socket.c and sdev.c respectively, form the upper and lower halves of
the new BSD socket support in VFS. New mapping functionality for
socket domains and drivers is added as well, implemented in smap.c.
The rest of the changes mainly facilitate the separation of character
and socket driver calls, and do not make any fundamental alterations.
For example, while this patch changes VFS's select.c rather heavily,
the new select logic for socket drivers is the exact same as for
character drivers; the changes mainly separate the driver type
specific parts from the generic select logic further than before.
Change-Id: I2f13084dd3c8d3a68bfc69da0621120c8291f707
This patch introduces the first piece of support for the concept of
"socket drivers": services that implement one or more socket protocol
families. The latter are also known as "domains", as per the first
parameter of the socket(2) API. More specifically, this patch adds
the basic infrastructure for specifying that a particular service is
the socket driver for a set of domains.
Unlike major number mappings for block and character drivers, socket
domain mappings are static. For that reason, they are specified in
system.conf files, using the "domain" keyword. Such a keyword is to
be followed by one or more protocol families, without their "PF_"
prefix. For example, a service with the line "domain INET INET6;"
will be mapped as the socket driver responsible for the AF_INET and
AF_INET6 protocol families.
This patch implements only the infrastructure for creating such
mappings; the actual mapping will be implemented in VFS in a later
patch. The infrastructure is implemented in service(8), RS, and VFS.
For now there is a hardcoded limit of eight domains per socket driver.
This may sound like a lot, but the upcoming new LWIP service will
already use four of those. Also, it is allowed for a service to be
both a block/character driver and a socket driver at the same time,
which is a requirement for the new LWIP service.
Change-Id: I93352d488fc6c481e7079248082895d388c39f2d
