MFC r352119-r352124, r352130

Stop linking to libl by specifying we do not need yywrap

MFC r326276:

various: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Add to CTL initial support for CDROMs and removable devices.

Relnotes: yes

Add ctl-lun config option for consistency in HA setups.

Add two new portal group options "tag" and "foreign".

They are going to be useful in clustered setups.

Allow '@' in unquoted strings, such as with the "path" statement. Note
that one can use any character they like by using double quotes.

PR: 200895
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation

Eliminate unused headers.

Teach ctld(8) to control non-iSCSI CTL ports.

This change introduces new target option "port", that assigns current target
to specified CTL port. On config application ctld(8) will apply LUN mapping
according to target configuration to specified port and bring the port up.
On shutdown cltd(8) will remove the mapping and put the port down.

This change allows to configure both iSCSI and FibreChannel targets in the
same configuration file in alike way.

Kernel side support was added earlier at r278037.

MFC after: 2 weeks
Relnotes: yes
Sponsored by: iXsystems, Inc.

Make it possible to set (via ctl.conf(5)) and query (via ctladm islist -v)
target iSCSI offload. Add mechanism to query maximum receive data segment
size supported by chosen hardware offload module, and use it in ctld(8)
to determine the value to advertise to the other side.

MFC after: 1 month
Sponsored by: The FreeBSD Foundation

Add support for sending redirections to iSCSI target.

MFC after: 1 month
Sponsored by: The FreeBSD Foundation

Fix iscsictl(8) and ctld(8) to correctly handle Windows newlines
(CRLF) in iscsi.conf and ctl.conf.

MFC after: 1 month
Sponsored by: The FreeBSD Foundation

Make it possible to optionally use semicolon to separate statements.
This makes it possible to format stuff like this:

target xxx {
lun 0 { path /foo/bar; size 4G; }
}

MFC after: 1 month
Sponsored by: The FreeBSD Foundation

Add discovery-filter. This makes it possible to restrict which targets
are returned during discovery based on initiator portal, name, and CHAP
credentials.

Reviewed by: mav@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation

Remove the distinction between strings and numbers from ctld(8) yacc parser.
This fixes problems with passing strings that look like numbers to clauses
that expect strings; previously it caused syntax errors and had to be worked
by user, using quotes. The workaround introduced in r267833 is no longer
neccessary.

MFC after: 1 month
Sponsored by: The FreeBSD Foundation

Add basic iSNS client to the iSCSI target.

This makes ctld(8) register its iSCSI targets and portals on configured
iSNS servers to allow initiators find them without active discovery.

Fetching of allowed initiators from iSNS is not implemented now, so target
ACLs still should be configured manually.

Reviewed by: trasz@
MFC after: 1 month
Sponsored by: iXsystems, Inc.

Fix issues in config parser relating to lun serial numbers.

Without this fix some serial numbers needed to be quoted
to avoid the config parser bailing out.

Submitted by: delphij
Sponsored by: iXsystems

Make ctld error out on invalid characters in ctl.conf.

Sponsored by: The FreeBSD Foundation

Add auth-type.

Sponsored by: The FreeBSD Foundation

Implement initiator-name and initiator-portal restrictions.

Sponsored by: The FreeBSD Foundation

Bring in the new iSCSI target and initiator.

Reviewed by: ken (parts)
Approved by: re (delphij)
Sponsored by: FreeBSD Foundation