Freeradius 3.0.21 with chroot enables fails to start from the Systemd unit file.

18 Apr 2022

      Hello all,

I am trying to test chroot on a Raspberry Pi running the distro-provided 
Freeradius 3.0.21 on the 32bit Raspberry Pi OS (Debian) 11.

According to the instructions from networkradius.com and freeradius -X 
error messages, I created the chroot folder hierarchy and the required 
files as shown below:

The character devices null, zero, random and urandom were created under 
/var/freeradius/chroot/dev.

/var/freeradius/chroot/etc/ssl/certs
/var/freeradius/chroot/etc/ssl/certs/private
/var/freeradius/chroot/etc/passwd
/var/freeradius/chroot/var/run

The following folders and files are bind mounted in the chroot:
/var/freeradius/chroot/usr/lib/freeradius/
/var/freeradius/chroot/usr/lib/arm-linux-gnueabihf/
/var/freeradius/chroot/etc/freeradius/3.0/certs/
/var/freeradius/chroot/etc/freeradius/3.0/mods-config/
/var/freeradius/chroot/etc/nsswitch.conf
/var/freeradius/chroot/etc/resolv.conf
/var/freeradius/chroot/var/log/freeradius/

The ownership and permission bits for all files and folders in the 
chroot folder are the same as their non-chrooted counterparts.

Finally, I enabled chroot in radiusd.conf.

Running freeradius -X, the debug output seems to be *exactly* the same 
as running freeradius -X with chroot disabled (well, only the line 
chroot = "/var/freeradius/chroot" was added in the security {} block 
output). While running the chrooted Freeradius as freeradius -X, 
Freeradius performs client authentication with EAP-PEAP and EAP-(T)TLS, 
proxing, etc normally. If -P is provided (freeradius -XP), the PID file 
is created in the /var/freeradius/chroot/var/run/ as expected. The 
output of freeradius -X with chroot enabled is given below:

---------------freeradius -X output------------------------
FreeRADIUS Version 3.0.21
Copyright (C) 1999-2019 The FreeRADIUS server project and contributors
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE
You may redistribute copies of FreeRADIUS under the terms of the
GNU General Public License
For more information about these matters, see the file named COPYRIGHT
Starting - reading configuration files ...
including dictionary file /usr/share/freeradius/dictionary
including dictionary file /usr/share/freeradius/dictionary.dhcp
including dictionary file /usr/share/freeradius/dictionary.vqp
including dictionary file /etc/freeradius/3.0/dictionary
including configuration file /etc/freeradius/3.0/radiusd.conf
including configuration file /etc/freeradius/3.0/proxy.conf
including configuration file /etc/freeradius/3.0/clients.conf
including files in directory /etc/freeradius/3.0/mods-enabled/
including configuration file /etc/freeradius/3.0/mods-enabled/detail
including configuration file /etc/freeradius/3.0/mods-enabled/realm
including configuration file /etc/freeradius/3.0/mods-enabled/attr_filter
including configuration file /etc/freeradius/3.0/mods-enabled/always
including configuration file /etc/freeradius/3.0/mods-enabled/replicate
including configuration file /etc/freeradius/3.0/mods-enabled/expiration
including configuration file /etc/freeradius/3.0/mods-enabled/files
including configuration file /etc/freeradius/3.0/mods-enabled/digest
including configuration file /etc/freeradius/3.0/mods-enabled/ntlm_auth
including configuration file /etc/freeradius/3.0/mods-enabled/pap
including configuration file /etc/freeradius/3.0/mods-enabled/exec
including configuration file /etc/freeradius/3.0/mods-enabled/logintime
including configuration file 
/etc/freeradius/3.0/mods-enabled/dynamic_clients
including configuration file /etc/freeradius/3.0/mods-enabled/preprocess
including configuration file /etc/freeradius/3.0/mods-enabled/expr
including configuration file /etc/freeradius/3.0/mods-enabled/cache_eap
including configuration file /etc/freeradius/3.0/mods-enabled/echo
including configuration file /etc/freeradius/3.0/mods-enabled/passwd
including configuration file /etc/freeradius/3.0/mods-enabled/utf8
including configuration file /etc/freeradius/3.0/mods-enabled/eap
including configuration file /etc/freeradius/3.0/mods-enabled/soh
including configuration file /etc/freeradius/3.0/mods-enabled/chap
including configuration file /etc/freeradius/3.0/mods-enabled/radutmp
including configuration file /etc/freeradius/3.0/mods-enabled/detail.log
including configuration file /etc/freeradius/3.0/mods-enabled/linelog
including configuration file /etc/freeradius/3.0/mods-enabled/mschap
including configuration file /etc/freeradius/3.0/mods-enabled/unix
including configuration file /etc/freeradius/3.0/mods-enabled/sradutmp
including configuration file /etc/freeradius/3.0/mods-enabled/unpack
including files in directory /etc/freeradius/3.0/policy.d/
including configuration file 
/etc/freeradius/3.0/policy.d/moonshot-targeted-ids
including configuration file /etc/freeradius/3.0/policy.d/rfc7542
including configuration file /etc/freeradius/3.0/policy.d/canonicalization
including configuration file /etc/freeradius/3.0/policy.d/accounting
including configuration file /etc/freeradius/3.0/policy.d/cui
including configuration file /etc/freeradius/3.0/policy.d/dhcp
including configuration file /etc/freeradius/3.0/policy.d/abfab-tr
including configuration file /etc/freeradius/3.0/policy.d/operator-name
including configuration file /etc/freeradius/3.0/policy.d/eap
including configuration file /etc/freeradius/3.0/policy.d/control
including configuration file /etc/freeradius/3.0/policy.d/debug
including configuration file /etc/freeradius/3.0/policy.d/filter
including files in directory /etc/freeradius/3.0/sites-enabled/
including configuration file /etc/freeradius/3.0/sites-enabled/default
including configuration file /etc/freeradius/3.0/sites-enabled/inner-tunnel
main {
  security {
  	user = "freerad"
  	group = "freerad"
  	chroot = "/var/freeradius/chroot"
  	allow_core_dumps = no
  }
	name = "freeradius"
	prefix = "/usr"
	localstatedir = "/var"
	logdir = "/var/log/freeradius"
	run_dir = "/var/run/freeradius"
}
main {
	name = "freeradius"
	prefix = "/usr"
	localstatedir = "/var"
	sbindir = "/usr/sbin"
	logdir = "/var/log/freeradius"
	run_dir = "/var/run/freeradius"
	libdir = "/usr/lib/freeradius"
	radacctdir = "/var/log/freeradius/radacct"
	hostname_lookups = no
	max_request_time = 30
	cleanup_delay = 5
	max_requests = 16384
	pidfile = "/var/run/freeradius/freeradius.pid"
	checkrad = "/usr/sbin/checkrad"
	debug_level = 0
	proxy_requests = yes
  log {
  	stripped_names = no
  	auth = yes
  	auth_badpass = yes
  	auth_goodpass = no
  	colourise = yes
  	msg_denied = "You are already logged in - access denied"
  }
  resources {
  }
  security {
  	max_attributes = 200
  	reject_delay = 1.000000
  	status_server = yes
  }
}
radiusd: #### Loading Realms and Home Servers ####
  proxy server {
  	retry_delay = 5
  	retry_count = 3
  	default_fallback = no
  	dead_time = 120
  	wake_all_if_all_dead = no
  }
  home_server localhost {
  	ipaddr = 127.0.0.1
  	port = 1812
  	type = "auth"
  	secret = <<< secret >>>
  	response_window = 20.000000
  	response_timeouts = 1
  	max_outstanding = 65536
  	zombie_period = 40
  	status_check = "status-server"
  	ping_interval = 30
  	check_interval = 30
  	check_timeout = 4
  	num_answers_to_alive = 3
  	revive_interval = 120
   limit {
   	max_connections = 16
   	max_requests = 0
   	lifetime = 0
   	idle_timeout = 0
   }
   coa {
   	irt = 2
   	mrt = 16
   	mrc = 5
   	mrd = 30
   }
  }
  home_server home_server1 {
  	ipaddr = 192.168.1.10
  	port = 0
  	type = "auth+acct"
  	secret = <<< secret >>>
  	response_window = 30.000000
  	response_timeouts = 1
  	max_outstanding = 65536
  	zombie_period = 40
  	status_check = "none"
  	ping_interval = 30
  	check_timeout = 4
  	num_answers_to_alive = 3
  	revive_interval = 300
   limit {
   	max_connections = 16
   	max_requests = 0
   	lifetime = 0
   	idle_timeout = 0
   }
   coa {
   	irt = 2
   	mrt = 16
   	mrc = 5
   	mrd = 30
   }
  }
  home_server_pool my_auth_failover {
	type = fail-over
	home_server = localhost
  }
  realm example.com {
	auth_pool = my_auth_failover
  }
  home_server_pool test_local_pool {
	type = fail-over
	home_server = home_server1
  }
  realm MY_REALM {
	pool = test_local_pool
	nostrip
  }
  realm LOCAL {
  }
radiusd: #### Loading Clients ####
  client localhost {
  	ipaddr = 127.0.0.1
  	require_message_authenticator = no
  	secret = <<< secret >>>
  	nas_type = "other"
  	proto = "*"
   limit {
   	max_connections = 16
   	lifetime = 0
   	idle_timeout = 30
   }
  }
  client localhost_ipv6 {
  	ipv6addr = ::1
  	require_message_authenticator = no
  	secret = <<< secret >>>
   limit {
   	max_connections = 16
   	lifetime = 0
   	idle_timeout = 30
   }
  }
  client 192.168.1.11 {
  	ipaddr = 192.168.1.11
  	require_message_authenticator = no
  	secret = <<< secret >>>
   limit {
   	max_connections = 16
   	lifetime = 0
   	idle_timeout = 30
   }
  }
Debugger not attached
systemd watchdog is disabled
  # Creating Auth-Type = eap
  # Creating Auth-Type = mschap
  # Creating Auth-Type = PAP
  # Creating Auth-Type = CHAP
  # Creating Auth-Type = MS-CHAP
radiusd: #### Instantiating modules ####
  modules {
   # Loaded module rlm_detail
   # Loading module "detail" from file 
/etc/freeradius/3.0/mods-enabled/detail
   detail {
   	filename = 
"/var/log/freeradius/radacct/%{%{Packet-Src-IP-Address}:-%{Packet-Src-IPv6-Address}}/detail-%Y%m%d"
   	header = "%t"
   	permissions = 384
   	locking = no
   	escape_filenames = no
   	log_packet_header = no
   }
   # Loaded module rlm_realm
   # Loading module "IPASS" from file /etc/freeradius/3.0/mods-enabled/realm
   realm IPASS {
   	format = "prefix"
   	delimiter = "/"
   	ignore_default = no
   	ignore_null = no
   }
   # Loading module "suffix" from file 
/etc/freeradius/3.0/mods-enabled/realm
   realm suffix {
   	format = "suffix"
   	delimiter = "@"
   	ignore_default = no
   	ignore_null = no
   }
   # Loading module "bangpath" from file 
/etc/freeradius/3.0/mods-enabled/realm
   realm bangpath {
   	format = "prefix"
   	delimiter = "!"
   	ignore_default = no
   	ignore_null = no
   }
   # Loading module "realmpercent" from file 
/etc/freeradius/3.0/mods-enabled/realm
   realm realmpercent {
   	format = "suffix"
   	delimiter = "%"
   	ignore_default = no
   	ignore_null = no
   }
   # Loading module "ntdomain" from file 
/etc/freeradius/3.0/mods-enabled/realm
   realm ntdomain {
   	format = "prefix"
   	delimiter = "\\"
   	ignore_default = no
   	ignore_null = no
   }
   # Loaded module rlm_attr_filter
   # Loading module "attr_filter.post-proxy" from file 
/etc/freeradius/3.0/mods-enabled/attr_filter
   attr_filter attr_filter.post-proxy {
   	filename = "/etc/freeradius/3.0/mods-config/attr_filter/post-proxy"
   	key = "%{Realm}"
   	relaxed = no
   }
   # Loading module "attr_filter.pre-proxy" from file 
/etc/freeradius/3.0/mods-enabled/attr_filter
   attr_filter attr_filter.pre-proxy {
   	filename = "/etc/freeradius/3.0/mods-config/attr_filter/pre-proxy"
   	key = "%{Realm}"
   	relaxed = no
   }
   # Loading module "attr_filter.access_reject" from file 
/etc/freeradius/3.0/mods-enabled/attr_filter
   attr_filter attr_filter.access_reject {
   	filename = "/etc/freeradius/3.0/mods-config/attr_filter/access_reject"
   	key = "%{User-Name}"
   	relaxed = no
   }
   # Loading module "attr_filter.access_challenge" from file 
/etc/freeradius/3.0/mods-enabled/attr_filter
   attr_filter attr_filter.access_challenge {
   	filename = 
"/etc/freeradius/3.0/mods-config/attr_filter/access_challenge"
   	key = "%{User-Name}"
   	relaxed = no
   }
   # Loading module "attr_filter.accounting_response" from file 
/etc/freeradius/3.0/mods-enabled/attr_filter
   attr_filter attr_filter.accounting_response {
   	filename = 
"/etc/freeradius/3.0/mods-config/attr_filter/accounting_response"
   	key = "%{User-Name}"
   	relaxed = no
   }
   # Loaded module rlm_always
   # Loading module "reject" from file 
/etc/freeradius/3.0/mods-enabled/always
   always reject {
   	rcode = "reject"
   	simulcount = 0
   	mpp = no
   }
   # Loading module "fail" from file /etc/freeradius/3.0/mods-enabled/always
   always fail {
   	rcode = "fail"
   	simulcount = 0
   	mpp = no
   }
   # Loading module "ok" from file /etc/freeradius/3.0/mods-enabled/always
   always ok {
   	rcode = "ok"
   	simulcount = 0
   	mpp = no
   }
   # Loading module "handled" from file 
/etc/freeradius/3.0/mods-enabled/always
   always handled {
   	rcode = "handled"
   	simulcount = 0
   	mpp = no
   }
   # Loading module "invalid" from file 
/etc/freeradius/3.0/mods-enabled/always
   always invalid {
   	rcode = "invalid"
   	simulcount = 0
   	mpp = no
   }
   # Loading module "userlock" from file 
/etc/freeradius/3.0/mods-enabled/always
   always userlock {
   	rcode = "userlock"
   	simulcount = 0
   	mpp = no
   }
   # Loading module "notfound" from file 
/etc/freeradius/3.0/mods-enabled/always
   always notfound {
   	rcode = "notfound"
   	simulcount = 0
   	mpp = no
   }
   # Loading module "noop" from file /etc/freeradius/3.0/mods-enabled/always
   always noop {
   	rcode = "noop"
   	simulcount = 0
   	mpp = no
   }
   # Loading module "updated" from file 
/etc/freeradius/3.0/mods-enabled/always
   always updated {
   	rcode = "updated"
   	simulcount = 0
   	mpp = no
   }
   # Loaded module rlm_replicate
   # Loading module "replicate" from file 
/etc/freeradius/3.0/mods-enabled/replicate
   # Loaded module rlm_expiration
   # Loading module "expiration" from file 
/etc/freeradius/3.0/mods-enabled/expiration
   # Loaded module rlm_files
   # Loading module "files" from file /etc/freeradius/3.0/mods-enabled/files
   files {
   	filename = "/etc/freeradius/3.0/mods-config/files/authorize"
   	acctusersfile = "/etc/freeradius/3.0/mods-config/files/accounting"
   	preproxy_usersfile = "/etc/freeradius/3.0/mods-config/files/pre-proxy"
   }
   # Loaded module rlm_digest
   # Loading module "digest" from file 
/etc/freeradius/3.0/mods-enabled/digest
   # Loaded module rlm_exec
   # Loading module "ntlm_auth" from file 
/etc/freeradius/3.0/mods-enabled/ntlm_auth
   exec ntlm_auth {
   	wait = yes
   	program = "/path/to/ntlm_auth --request-nt-key --domain=MYDOMAIN 
--username=%{mschap:User-Name} --password=%{User-Password}"
   	shell_escape = yes
   }
   # Loaded module rlm_pap
   # Loading module "pap" from file /etc/freeradius/3.0/mods-enabled/pap
   pap {
   	normalise = yes
   }
   # Loading module "exec" from file /etc/freeradius/3.0/mods-enabled/exec
   exec {
   	wait = no
   	input_pairs = "request"
   	shell_escape = yes
   	timeout = 10
   }
   # Loaded module rlm_logintime
   # Loading module "logintime" from file 
/etc/freeradius/3.0/mods-enabled/logintime
   logintime {
   	minimum_timeout = 60
   }
   # Loaded module rlm_dynamic_clients
   # Loading module "dynamic_clients" from file 
/etc/freeradius/3.0/mods-enabled/dynamic_clients
   # Loaded module rlm_preprocess
   # Loading module "preprocess" from file 
/etc/freeradius/3.0/mods-enabled/preprocess
   preprocess {
   	huntgroups = "/etc/freeradius/3.0/mods-config/preprocess/huntgroups"
   	hints = "/etc/freeradius/3.0/mods-config/preprocess/hints"
   	with_ascend_hack = no
   	ascend_channels_per_line = 23
   	with_ntdomain_hack = no
   	with_specialix_jetstream_hack = no
   	with_cisco_vsa_hack = no
   	with_alvarion_vsa_hack = no
   }
   # Loaded module rlm_expr
   # Loading module "expr" from file /etc/freeradius/3.0/mods-enabled/expr
   expr {
   	safe_characters = 
"@abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.-_: 
/äéöüàâæçèéêëîïôœùûüaÿÄÉÖÜßÀÂÆÇÈÉÊËÎÏÔŒÙÛÜŸ"
   }
   # Loaded module rlm_cache
   # Loading module "cache_eap" from file 
/etc/freeradius/3.0/mods-enabled/cache_eap
   cache cache_eap {
   	driver = "rlm_cache_rbtree"
   	key = "%{%{control:State}:-%{%{reply:State}:-%{State}}}"
   	ttl = 15
   	max_entries = 0
   	epoch = 0
   	add_stats = no
   }
   # Loading module "echo" from file /etc/freeradius/3.0/mods-enabled/echo
   exec echo {
   	wait = yes
   	program = "/bin/echo %{User-Name}"
   	input_pairs = "request"
   	output_pairs = "reply"
   	shell_escape = yes
   }
   # Loaded module rlm_passwd
   # Loading module "etc_passwd" from file 
/etc/freeradius/3.0/mods-enabled/passwd
   passwd etc_passwd {
   	filename = "/etc/passwd"
   	format = "*User-Name:Crypt-Password:"
   	delimiter = ":"
   	ignore_nislike = no
   	ignore_empty = yes
   	allow_multiple_keys = no
   	hash_size = 100
   }
   # Loaded module rlm_utf8
   # Loading module "utf8" from file /etc/freeradius/3.0/mods-enabled/utf8
   # Loaded module rlm_eap
   # Loading module "eap" from file /etc/freeradius/3.0/mods-enabled/eap
   eap {
   	default_eap_type = "peap"
   	timer_expire = 60
   	ignore_unknown_eap_types = no
   	cisco_accounting_username_bug = no
   	max_sessions = 16384
   }
   # Loaded module rlm_soh
   # Loading module "soh" from file /etc/freeradius/3.0/mods-enabled/soh
   soh {
   	dhcp = yes
   }
   # Loaded module rlm_chap
   # Loading module "chap" from file /etc/freeradius/3.0/mods-enabled/chap
   # Loaded module rlm_radutmp
   # Loading module "radutmp" from file 
/etc/freeradius/3.0/mods-enabled/radutmp
   radutmp {
   	filename = "/var/log/freeradius/radutmp"
   	username = "%{User-Name}"
   	case_sensitive = yes
   	check_with_nas = yes
   	permissions = 384
   	caller_id = yes
   }
   # Loading module "auth_log" from file 
/etc/freeradius/3.0/mods-enabled/detail.log
   detail auth_log {
   	filename = 
"/var/log/freeradius/radacct/%{%{Packet-Src-IP-Address}:-%{Packet-Src-IPv6-Address}}/auth-detail-%Y%m%d"
   	header = "%t"
   	permissions = 384
   	locking = no
   	escape_filenames = no
   	log_packet_header = no
   }
   # Loading module "reply_log" from file 
/etc/freeradius/3.0/mods-enabled/detail.log
   detail reply_log {
   	filename = 
"/var/log/freeradius/radacct/%{%{Packet-Src-IP-Address}:-%{Packet-Src-IPv6-Address}}/reply-detail-%Y%m%d"
   	header = "%t"
   	permissions = 384
   	locking = no
   	escape_filenames = no
   	log_packet_header = no
   }
   # Loading module "pre_proxy_log" from file 
/etc/freeradius/3.0/mods-enabled/detail.log
   detail pre_proxy_log {
   	filename = 
"/var/log/freeradius/radacct/%{%{Packet-Src-IP-Address}:-%{Packet-Src-IPv6-Address}}/pre-proxy-detail-%Y%m%d"
   	header = "%t"
   	permissions = 384
   	locking = no
   	escape_filenames = no
   	log_packet_header = no
   }
   # Loading module "post_proxy_log" from file 
/etc/freeradius/3.0/mods-enabled/detail.log
   detail post_proxy_log {
   	filename = 
"/var/log/freeradius/radacct/%{%{Packet-Src-IP-Address}:-%{Packet-Src-IPv6-Address}}/post-proxy-detail-%Y%m%d"
   	header = "%t"
   	permissions = 384
   	locking = no
   	escape_filenames = no
   	log_packet_header = no
   }
   # Loaded module rlm_linelog
   # Loading module "linelog" from file 
/etc/freeradius/3.0/mods-enabled/linelog
   linelog {
   	filename = "/var/log/freeradius/linelog"
   	escape_filenames = no
   	syslog_severity = "info"
   	permissions = 384
   	format = "This is a log message for %{User-Name}"
   	reference = "messages.%{%{reply:Packet-Type}:-default}"
   }
   # Loading module "log_accounting" from file 
/etc/freeradius/3.0/mods-enabled/linelog
   linelog log_accounting {
   	filename = "/var/log/freeradius/linelog-accounting"
   	escape_filenames = no
   	syslog_severity = "info"
   	permissions = 384
   	format = ""
   	reference = "Accounting-Request.%{%{Acct-Status-Type}:-unknown}"
   }
   # Loaded module rlm_mschap
   # Loading module "mschap" from file 
/etc/freeradius/3.0/mods-enabled/mschap
   mschap {
   	use_mppe = yes
   	require_encryption = yes
   	require_strong = yes
   	with_ntdomain_hack = yes
    passchange {
    }
   	allow_retry = yes
   	winbind_retry_with_normalised_username = no
   }
   # Loaded module rlm_unix
   # Loading module "unix" from file /etc/freeradius/3.0/mods-enabled/unix
   unix {
   	radwtmp = "/var/log/freeradius/radwtmp"
   }
Creating attribute Unix-Group
   # Loading module "sradutmp" from file 
/etc/freeradius/3.0/mods-enabled/sradutmp
   radutmp sradutmp {
   	filename = "/var/log/freeradius/sradutmp"
   	username = "%{User-Name}"
   	case_sensitive = yes
   	check_with_nas = yes
   	permissions = 420
   	caller_id = no
   }
   # Loaded module rlm_unpack
   # Loading module "unpack" from file 
/etc/freeradius/3.0/mods-enabled/unpack
   instantiate {
   }
   # Instantiating module "detail" from file 
/etc/freeradius/3.0/mods-enabled/detail
   # Instantiating module "IPASS" from file 
/etc/freeradius/3.0/mods-enabled/realm
   # Instantiating module "suffix" from file 
/etc/freeradius/3.0/mods-enabled/realm
   # Instantiating module "bangpath" from file 
/etc/freeradius/3.0/mods-enabled/realm
   # Instantiating module "realmpercent" from file 
/etc/freeradius/3.0/mods-enabled/realm
   # Instantiating module "ntdomain" from file 
/etc/freeradius/3.0/mods-enabled/realm
   # Instantiating module "attr_filter.post-proxy" from file 
/etc/freeradius/3.0/mods-enabled/attr_filter
reading pairlist file /etc/freeradius/3.0/mods-config/attr_filter/post-proxy
   # Instantiating module "attr_filter.pre-proxy" from file 
/etc/freeradius/3.0/mods-enabled/attr_filter
reading pairlist file /etc/freeradius/3.0/mods-config/attr_filter/pre-proxy
   # Instantiating module "attr_filter.access_reject" from file 
/etc/freeradius/3.0/mods-enabled/attr_filter
reading pairlist file 
/etc/freeradius/3.0/mods-config/attr_filter/access_reject
   # Instantiating module "attr_filter.access_challenge" from file 
/etc/freeradius/3.0/mods-enabled/attr_filter
reading pairlist file 
/etc/freeradius/3.0/mods-config/attr_filter/access_challenge
   # Instantiating module "attr_filter.accounting_response" from file 
/etc/freeradius/3.0/mods-enabled/attr_filter
reading pairlist file 
/etc/freeradius/3.0/mods-config/attr_filter/accounting_response
   # Instantiating module "reject" from file 
/etc/freeradius/3.0/mods-enabled/always
   # Instantiating module "fail" from file 
/etc/freeradius/3.0/mods-enabled/always
   # Instantiating module "ok" from file 
/etc/freeradius/3.0/mods-enabled/always
   # Instantiating module "handled" from file 
/etc/freeradius/3.0/mods-enabled/always
   # Instantiating module "invalid" from file 
/etc/freeradius/3.0/mods-enabled/always
   # Instantiating module "userlock" from file 
/etc/freeradius/3.0/mods-enabled/always
   # Instantiating module "notfound" from file 
/etc/freeradius/3.0/mods-enabled/always
   # Instantiating module "noop" from file 
/etc/freeradius/3.0/mods-enabled/always
   # Instantiating module "updated" from file 
/etc/freeradius/3.0/mods-enabled/always
   # Instantiating module "expiration" from file 
/etc/freeradius/3.0/mods-enabled/expiration
   # Instantiating module "files" from file 
/etc/freeradius/3.0/mods-enabled/files
reading pairlist file /etc/freeradius/3.0/mods-config/files/authorize
reading pairlist file /etc/freeradius/3.0/mods-config/files/accounting
reading pairlist file /etc/freeradius/3.0/mods-config/files/pre-proxy
   # Instantiating module "pap" from file 
/etc/freeradius/3.0/mods-enabled/pap
   # Instantiating module "logintime" from file 
/etc/freeradius/3.0/mods-enabled/logintime
   # Instantiating module "preprocess" from file 
/etc/freeradius/3.0/mods-enabled/preprocess
reading pairlist file /etc/freeradius/3.0/mods-config/preprocess/huntgroups
reading pairlist file /etc/freeradius/3.0/mods-config/preprocess/hints
   # Instantiating module "cache_eap" from file 
/etc/freeradius/3.0/mods-enabled/cache_eap
rlm_cache (cache_eap): Driver rlm_cache_rbtree (module rlm_cache_rbtree) 
loaded and linked
   # Instantiating module "etc_passwd" from file 
/etc/freeradius/3.0/mods-enabled/passwd
rlm_passwd: nfields: 3 keyfield 0(User-Name) listable: no
   # Instantiating module "eap" from file 
/etc/freeradius/3.0/mods-enabled/eap
    # Linked to sub-module rlm_eap_tls
    tls {
    	tls = "tls-common"
    }
    tls-config tls-common {
    	verify_depth = 0
    	ca_path = "/etc/freeradius/3.0/certs"
    	pem_file_type = yes
    	private_key_file = "/etc/ssl/private/freeradius.key"
    	certificate_file = "/etc/ssl/certs/freeradius.crt"
    	ca_file = 
"/usr/local/share/ca-certificates/ca-certificates-freeradius.crt"
    	private_key_password = <<< secret >>>
    	dh_file = "/etc/freeradius/3.0/certs/dh"
    	random_file = "/dev/urandom"
    	fragment_size = 1024
    	include_length = yes
    	auto_chain = yes
    	check_crl = no
    	check_all_crl = no
    	cipher_list = "DEFAULT"
    	cipher_server_preference = no
    	ecdh_curve = "prime256v1"
    	tls_max_version = "1.2"
    	tls_min_version = "1.2"
     cache {
     	enable = no
     	lifetime = 24
     	max_entries = 255
     }
     verify {
     	skip_if_ocsp_ok = no
     }
     ocsp {
     	enable = no
     	override_cert_url = yes
     	url = "http://127.0.0.1/ocsp/"
     	use_nonce = yes
     	timeout = 0
     	softfail = no
     }
    }
    # Linked to sub-module rlm_eap_ttls
    ttls {
    	tls = "tls-common"
    	default_eap_type = "mschapv2"
    	copy_request_to_tunnel = no
    	use_tunneled_reply = no
    	virtual_server = "inner-tunnel"
    	include_length = yes
    	require_client_cert = no
    }
tls: Using cached TLS configuration from previous invocation
    # Linked to sub-module rlm_eap_peap
    peap {
    	tls = "tls-common"
    	default_eap_type = "mschapv2"
    	copy_request_to_tunnel = no
    	use_tunneled_reply = no
    	proxy_tunneled_request_as_eap = yes
    	virtual_server = "inner-tunnel"
    	soh = no
    	require_client_cert = no
    }
tls: Using cached TLS configuration from previous invocation
    # Linked to sub-module rlm_eap_mschapv2
    mschapv2 {
    	with_ntdomain_hack = no
    	send_error = no
    }
   # Instantiating module "auth_log" from file 
/etc/freeradius/3.0/mods-enabled/detail.log
rlm_detail (auth_log): 'User-Password' suppressed, will not appear in 
detail output
   # Instantiating module "reply_log" from file 
/etc/freeradius/3.0/mods-enabled/detail.log
   # Instantiating module "pre_proxy_log" from file 
/etc/freeradius/3.0/mods-enabled/detail.log
   # Instantiating module "post_proxy_log" from file 
/etc/freeradius/3.0/mods-enabled/detail.log
   # Instantiating module "linelog" from file 
/etc/freeradius/3.0/mods-enabled/linelog
   # Instantiating module "log_accounting" from file 
/etc/freeradius/3.0/mods-enabled/linelog
   # Instantiating module "mschap" from file 
/etc/freeradius/3.0/mods-enabled/mschap
rlm_mschap (mschap): using internal authentication
  } # modules
radiusd: #### Loading Virtual Servers ####
server { # from file /etc/freeradius/3.0/radiusd.conf
} # server
server default { # from file /etc/freeradius/3.0/sites-enabled/default
  # Loading authenticate {...}
  # Loading authorize {...}
  # Loading preacct {...}
  # Loading accounting {...}
Ignoring "sql" (see raddb/mods-available/README.rst)
  # Loading post-proxy {...}
  # Loading post-auth {...}
} # server default
server inner-tunnel { # from file 
/etc/freeradius/3.0/sites-enabled/inner-tunnel
  # Loading authenticate {...}
  # Loading authorize {...}
  # Loading session {...}
  # Loading post-proxy {...}
  # Loading post-auth {...}
  # Skipping contents of 'if' as it is always 'false' -- 
/etc/freeradius/3.0/sites-enabled/inner-tunnel:335
} # server inner-tunnel
radiusd: #### Opening IP addresses and Ports ####
listen {
   	type = "auth"
   	ipv4addr = 192.168.1.20
   	port = 0
    limit {
    	max_connections = 16
    	lifetime = 0
    	idle_timeout = 30
    }
}
listen {
   	type = "acct"
   	ipv4addr = 192.168.1.20
   	port = 0
    limit {
    	max_connections = 16
    	lifetime = 0
    	idle_timeout = 30
    }
}
listen {
   	type = "auth"
   	ipv6addr = ::
   	port = 0
    limit {
    	max_connections = 16
    	lifetime = 0
    	idle_timeout = 30
    }
}
listen {
   	type = "acct"
   	ipv6addr = ::
   	port = 0
    limit {
    	max_connections = 16
    	lifetime = 0
    	idle_timeout = 30
    }
}
listen {
   	type = "auth"
   	ipaddr = 127.0.0.1
   	port = 18120
}
Listening on auth address 192.168.1.20 port 1812 bound to server default
Listening on acct address 192.168.1.20 port 1813 bound to server default
Listening on auth address :: port 1812 bound to server default
Listening on acct address :: port 1813 bound to server default
Listening on auth address 127.0.0.1 port 18120 bound to server inner-tunnel
Listening on proxy address * port 44958
Listening on proxy address :: port 32891
Ready to process requests

---------------End of freeradius -X output-----------------

If I try to start the chrooted Freeradius from the provided Systemd 
startup script, it fails and journalctl -xe returns the following:

---------------journalctl -xe output --------------------------
Support: https://www.debian.org/support
The unit freeradius.service completed and consumed the indicated resources.
Apr 16 14:14:36 raspberry systemd[1]: Starting FreeRADIUS multi-protocol 
policy server...
Subject: A start job for unit freeradius.service has begun execution
Defined-By: systemd
Support: https://www.debian.org/support

A start job for unit freeradius.service has begun execution.
The job identifier is 2157.
Apr 16 14:14:37 raspberry freeradius[2624]: FreeRADIUS Version 3.0.21
Apr 16 14:14:37 raspberry freeradius[2624]: Copyright (C) 1999-2019 The 
FreeRADIUS server project and contributors
Apr 16 14:14:37 raspberry freeradius[2624]: There is NO warranty; not 
even for MERCHANTABILITY or FITNESS FOR A
Apr 16 14:14:37 raspberry freeradius[2624]: PARTICULAR PURPOSE
Apr 16 14:14:37 raspberry freeradius[2624]: You may redistribute copies 
of FreeRADIUS under the terms of the
Apr 16 14:14:37 raspberry freeradius[2624]: GNU General Public License
Apr 16 14:14:37 raspberry freeradius[2624]: For more information about 
these matters, see the file named COPYRIGHT
Apr 16 14:14:37 raspberry freeradius[2624]: Starting - reading 
configuration files ...
Apr 16 14:14:37 raspberry freeradius[2624]: Debug state unknown 
(cap_sys_ptrace capability not set)
Apr 16 14:14:37 raspberry freeradius[2624]: Creating attribute Unix-Group
Apr 16 14:14:37 raspberry freeradius[2624]: rlm_cache (cache_eap): 
Driver rlm_cache_rbtree (module rlm_cache_rbtree) loaded and linked
Apr 16 14:14:37 raspberry freeradius[2624]: tls: Using cached TLS 
configuration from previous invocation
Apr 16 14:14:37 raspberry freeradius[2624]: tls: Using cached TLS 
configuration from previous invocation
Apr 16 14:14:37 raspberry freeradius[2624]: rlm_detail (auth_log): 
'User-Password' suppressed, will not appear in detail output
Apr 16 14:14:37 raspberry freeradius[2624]: rlm_mschap (mschap): using 
internal authentication
Apr 16 14:14:37 raspberry freeradius[2624]: Ignoring "sql" (see 
raddb/mods-available/README.rst)
Apr 16 14:14:37 raspberry freeradius[2624]:  # Skipping contents of 'if' 
as it is always 'false' -- 
/etc/freeradius/3.0/sites-enabled/inner-tunnel:335
Apr 16 14:14:37 raspberry freeradius[2624]: radiusd: #### Skipping IP 
addresses and Ports ####
Apr 16 14:14:37 raspberry freeradius[2624]: Configuration appears to be OK
Apr 16 14:14:37 raspberry systemd[1]: freeradius.service: Main process 
exited, code=exited, status=1/FAILURE
Subject: Unit process exited
Defined-By: systemd
Support: https://www.debian.org/support

An ExecStart= process belonging to unit freeradius.service has exited.

The process' exit code is 'exited' and its exit status is 1.
Apr 16 14:14:37 raspberry systemd[1]: freeradius.service: Failed with 
result 'exit-code'.
Subject: Unit failed
Defined-By: systemd
Support: https://www.debian.org/support

The unit freeradius.service has entered the 'failed' state with result 
'exit-code'.
Apr 16 14:14:37 raspberry systemd[1]: Failed to start FreeRADIUS 
multi-protocol policy server.
Subject: A start job for unit freeradius.service has failed
Defined-By: systemd
Support: https://www.debian.org/support

A start job for unit freeradius.service has finished with a failure.

The job identifier is 2157 and the job result is failed.
Apr 16 14:14:37 raspberry systemd[1]: freeradius.service: Consumed 
1.338s CPU time.
Subject: Resources consumed by unit runtime
Defined-By: systemd
Support: https://www.debian.org/support

The unit freeradius.service completed and consumed the indicated resources.
---------------End of journalctl -xe output--------------------

Although I am not a Systemd or a Freeradius guru, I made a simple 
investigation with the following results:

1) The provided systemd script contains the following lines:
ExecStartPre=/usr/sbin/freeradius $FREERADIUS_OPTIONS -Cx -lstdout
ExecStart=/usr/sbin/freeradius -f $FREERADIUS_OPTIONS

The variable $FREERADIUS_OPTIONS populated in /etc/default/freeradius is 
set to an empty string ("") - the provided default value.

2) The command in ExecStartPre (/usr/sbin/freeradius -Cx -lstdout) 
always returns with the message "Configuration appears to be OK".

3) If I run freeradius -f -lstdout (as shown above in ExecStart) from 
the command line, I am getting the following output depending on the 
user I am logged in:

a) As 'root' *regardless if chroot is enabled or not* or as 'freerad' 
(the Freeradius user in Debian) *with chroot disabled*, the output is:

----------freeradius -f -lstdout output---------------------
root@raspberry:~# freeradius -f -lstdout
Sat Apr 16 14:23:07 2022 : Info: Starting - reading configuration files ...
Sat Apr 16 14:23:07 2022 : Info: Debugger not attached
Sat Apr 16 14:23:07 2022 : Info: systemd watchdog is disabled
Sat Apr 16 14:23:07 2022 : Info: Loaded virtual server <default>
Sat Apr 16 14:23:07 2022 : Warning: Ignoring "sql" (see 
raddb/mods-available/README.rst)
Sat Apr 16 14:23:07 2022 : Info: Loaded virtual server default
Sat Apr 16 14:23:07 2022 : Info:  # Skipping contents of 'if' as it is 
always 'false' -- /etc/freeradius/3.0/sites-enabled/inner-tunnel:335
Sat Apr 16 14:23:07 2022 : Info: Loaded virtual server inner-tunnel
Sat Apr 16 14:23:07 2022 : Info: Ready to process requests
----------End of freeradius -f -lstdout output--------------

b) As 'freerad' *with chroot enabled*, freeradius -f -lstdout returns 
immediately without reporting or logging any error(s):

----------freeradius -f -lstdout output---------------------
freerad@raspberry:$ freeradius -f -lstdout
Sat Apr 16 14:24:50 2022 : Info: Starting - reading configuration files ...
freerad@raspberry:$
----------End of freeradius -f -lstdout output--------------

Is this a permission problem or am I doing something wrong?

Thank you in advance,
Antonios

Freeradius 3.0.21 with chroot enables fails to start from the Systemd unit file.

Antonios Kalkakos