libucl-based configuration file parser for ctld

[jceel]

Summary

This change adds additional, libucl-based configuration file parser to ctld. Parsing ctl.conf (or configuration file specified with -f) as an UCL file is enabled using -u command-line switch.

Test Plan

Example config file (which is actually in JSON format, fully compatible with UCL):

{
    "target": {
        "naa.5000c50006815e48": {
            "port": "camsim",
            "lun": [
                {
                    "number": 0,
                    "name": "disk1"
                },
                {
                    "number": 1,
                    "name": "disk3"
                },
                {
                    "number": 2,
                    "name": "disk4"
                }
            ]
        }
    },
    "lun": {
        "disk1": {
            "serial": "00505625139600",
            "blocksize": 512,
            "options": {
                "removable": "on",
                "product": "Virtual Disk",
                "vendor": "FreeNAS",
                "device-id": "Virtual Disk 00505625139600",
                "rpm": "7200",
                "naa": "0x6589cfc000000572122b119a12bbdac3"
            },
            "path": "/var/db/system/simulator/disk1"
        },
        "disk3": {
            "serial": "00505625139600",
            "blocksize": 512,
            "options": {
                "removable": "on",
                "product": "Virtual Disk",
                "vendor": "FreeNAS",
                "device-id": "Virtual Disk 00505625139600",
                "rpm": "7200",
                "naa": "0x6589cfc000000446222150ce63317d41"
            },
            "path": "/var/db/system/simulator/disk3"
        },
        "disk4": {
            "serial": "00505625139600",
            "blocksize": 512,
            "options": {
                "removable": "on",
                "product": "Virtual Disk",
                "vendor": "FreeNAS",
                "device-id": "Virtual Disk 00505625139600",
                "rpm": "7200",
                "naa": "0x6589cfc000000e7f80ec91885d4d80b9"
            },
            "path": "/var/db/system/simulator/disk4"
        },
        "disk2": {
            "serial": "00505625139600",
            "blocksize": 512,
            "options": {
                "removable": "on",
                "product": "Virtual Disk",
                "vendor": "FreeNAS",
                "device-id": "Virtual Disk 00505625139600",
                "rpm": "7200",
                "naa": "0x6589cfc000000ee13371ddb41ec93d01"
            },
            "path": "/var/db/system/simulator/disk2"
        }
    }
}

[jceel]

Initialize "tag" variable to NULL explicitly at uclparse.c:134.

[trasz]

usr.sbin/ctld/Makefile

5 ↗

(On Diff #11185)

This kind of looks like like it should be handled by LIBADD=ucl. Isn't it?

usr.sbin/ctld/ctld.c

2553 ↗

(On Diff #11185)

I liked the old order, ie check_perms after parse_conf/uclparse_conf. This way you would get an user-friendly error with path, if the configuration file doesn't exist.

2556 ↗

(On Diff #11185)

style(9) - superfluous "{}" bracees.

usr.sbin/ctld/uclparse.c

227 ↗

(On Diff #11185)

s/parse_toplevel/uclparse_toplevel/ ?

471 ↗

(On Diff #11185)

Empty line.

659 ↗

(On Diff #11185)

Unneeded braces.

692 ↗

(On Diff #11185)

Braces.

[jceel]

Style fixes; moved check_perms() after parse_conf()/uclparse_conf().