selinux-policy/policy/modules/services/cron.if

## <summary>Periodic execution of scheduled commands.</summary>

#######################################
## <summary>
##	The per user domain template for the cron module.
## </summary>
## <desc>
##	<p>
##	This template creates a derived domains which are used
##	for running programs on behalf of the user, from cron.
##	A type for the user crontab is also created.
##	</p>
##	<p>
##	This template is invoked automatically for each user, and
##	generally does not need to be invoked directly
##	by policy writers.
##	</p>
## </desc>
## <param name="userdomain_prefix">
##	<summary>
##	The prefix of the user domain (e.g., user
##	is the prefix for user_t).
##	</summary>
## </param>
## <param name="user_domain">
##	<summary>
##	The type of the user domain.
##	</summary>
## </param>
## <param name="user_role">
##	<summary>
##	The role associated with the user domain.
##	</summary>
## </param>
#
template(`cron_per_userdomain_template',`
	gen_require(`
		attribute cron_spool_type;
		type crond_t, cron_spool_t, crontab_exec_t;
	')

	# Type of user crontabs once moved to cron spool.
	type $1_cron_spool_t, cron_spool_type;
	files_type($1_cron_spool_t)

	type $1_crond_t;
	domain_type($1_crond_t)
	domain_cron_exemption_target($1_crond_t)
	corecmd_shell_entry_type($1_crond_t)
	role $3 types $1_crond_t;

	type $1_crontab_t;
	domain_type($1_crontab_t)
	domain_entry_file($1_crontab_t,crontab_exec_t)
	role $3 types $1_crontab_t;

	##############################
	#
	# $1_crond_t local policy
	#

	allow $1_crond_t self:capability dac_override;
	allow $1_crond_t self:process { signal_perms setsched };
	allow $1_crond_t self:fifo_file rw_file_perms;
	allow $1_crond_t self:unix_stream_socket create_stream_socket_perms;
	allow $1_crond_t self:unix_dgram_socket create_socket_perms;

	# The entrypoint interface is not used as this is not
	# a regular entrypoint.  Since crontab files are
	# not directly executed, crond must ensure that
	# the crontab file has a type that is appropriate
	# for the domain of the user cron job.  It
	# performs an entrypoint permission check
	# for this purpose.
	allow $1_crond_t $1_cron_spool_t:file entrypoint;

	# Permit a transition from the crond_t domain to this domain.
	# The transition is requested explicitly by the modified crond 
	# via setexeccon.  There is no way to set up an automatic
	# transition, since crontabs are configuration files, not executables.
	allow crond_t $1_crond_t:process transition;
	dontaudit crond_t $1_crond_t:process { noatsecure siginh rlimitinh };
	allow crond_t $1_crond_t:fd use;
	allow $1_crond_t crond_t:fd use;
	allow $1_crond_t crond_t:fifo_file rw_file_perms;
	allow $1_crond_t crond_t:process sigchld;

	kernel_read_system_state($1_crond_t)
	kernel_read_kernel_sysctls($1_crond_t)

	# ps does not need to access /boot when run from cron
	files_dontaudit_search_boot($1_crond_t)

	corenet_non_ipsec_sendrecv($1_crond_t)
	corenet_tcp_sendrecv_all_if($1_crond_t)
	corenet_udp_sendrecv_all_if($1_crond_t)
	corenet_tcp_sendrecv_all_nodes($1_crond_t)
	corenet_udp_sendrecv_all_nodes($1_crond_t)
	corenet_tcp_sendrecv_all_ports($1_crond_t)
	corenet_udp_sendrecv_all_ports($1_crond_t)
	corenet_tcp_connect_all_ports($1_crond_t)
	corenet_sendrecv_all_client_packets($1_crond_t)

	dev_read_urand($1_crond_t)

	fs_getattr_all_fs($1_crond_t)

	corecmd_exec_all_executables($1_crond_t)

	# quiet other ps operations
	domain_dontaudit_read_all_domains_state($1_crond_t)
	domain_dontaudit_getattr_all_domains($1_crond_t)

	files_read_usr_files($1_crond_t)
	files_exec_etc_files($1_crond_t)
	# for nscd:
	files_dontaudit_search_pids($1_crond_t)

	libs_use_ld_so($1_crond_t)
	libs_use_shared_libs($1_crond_t)
	libs_exec_lib_files($1_crond_t)
	libs_exec_ld_so($1_crond_t)

	files_read_etc_runtime_files($1_crond_t)
	files_read_var_files($1_crond_t)
	files_search_spool($1_crond_t)

	logging_search_logs($1_crond_t)

	seutil_read_config($1_crond_t)

	miscfiles_read_localization($1_crond_t)

	userdom_manage_user_tmp_files($1,$1_crond_t)
	userdom_manage_user_tmp_symlinks($1,$1_crond_t)
	userdom_manage_user_tmp_pipes($1,$1_crond_t)
	userdom_manage_user_tmp_sockets($1,$1_crond_t)
	# Run scripts in user home directory and access shared libs.
	userdom_exec_user_home_content_files($1,$1_crond_t)
	# Access user files and dirs.
#	userdom_manage_user_home_subdir_dirs($1,$1_crond_t)
	userdom_manage_user_home_content_files($1,$1_crond_t)
	userdom_manage_user_home_content_symlinks($1,$1_crond_t)
	userdom_manage_user_home_content_pipes($1,$1_crond_t)
	userdom_manage_user_home_content_sockets($1,$1_crond_t)
#	userdom_user_home_dir_filetrans_user_home_content($1,$1_crond_t,notdevfile_class_set)

	tunable_policy(`fcron_crond', `
		allow crond_t $1_cron_spool_t:file create_file_perms;
	')

	optional_policy(`
		nis_use_ypbind($1_crond_t)
	')

	ifdef(`TODO',`
	optional_policy(`
		create_dir_file($1_crond_t, httpd_$1_content_t)
	')
	allow $1_crond_t tmp_t:dir rw_dir_perms;
	type_transition $1_crond_t $1_tmp_t:{ file lnk_file sock_file fifo_file } $1_tmp_t;

	ifdef(`mta.te', `
		domain_auto_trans($1_crond_t, sendmail_exec_t, $1_mail_t)
		allow $1_crond_t sendmail_exec_t:lnk_file r_file_perms;

		# $1_mail_t should only be reading from the cron fifo not needing to write
		dontaudit $1_mail_t crond_t:fifo_file write;
		allow mta_user_agent $1_crond_t:fd use;
	')
	') dnl endif TODO

	##############################
	#
	# $1_crontab_t local policy
	#

	# Transition from the user domain to the derived domain.
	domain_auto_trans($2, crontab_exec_t, $1_crontab_t)
	allow $2 $1_crontab_t:fd use;
	allow $1_crontab_t $2:fd use;
	allow $1_crontab_t $2:fifo_file rw_file_perms;
	allow $1_crontab_t $2:process sigchld;

	# crontab shows up in user ps
	allow $2 $1_crontab_t:dir { search getattr read };
	allow $2 $1_crontab_t:{ file lnk_file } { read getattr };
	allow $2 $1_crontab_t:process getattr;
	dontaudit $2 $1_crontab_t:process ptrace;

	# for ^Z
	allow $2 $1_crontab_t:process signal;

	# Allow crond to read those crontabs in cron spool.
	allow crond_t $1_cron_spool_t:file create_file_perms;

	# dac_override is to create the file in the directory under /tmp
	allow $1_crontab_t self:capability { setuid setgid chown dac_override };
	allow $1_crontab_t self:process signal_perms;

	# create files in /var/spool/cron
	allow $1_crontab_t $1_cron_spool_t:file create_file_perms;
	allow $1_crontab_t cron_spool_t:dir rw_dir_perms;
	type_transition $1_crontab_t $1_cron_spool_t:file $1_cron_spool_t;

	# crontab signals crond by updating the mtime on the spooldir
	allow $1_crontab_t cron_spool_t:dir setattr;

	kernel_read_system_state($1_crontab_t)

	# for the checks used by crontab -u
	selinux_dontaudit_search_fs($1_crontab_t)

	fs_getattr_xattr_fs($1_crontab_t)

	# Run helper programs as the user domain
	corecmd_bin_domtrans($1_crontab_t,$2)
	corecmd_sbin_domtrans($1_crontab_t,$2)
	corecmd_shell_domtrans($1_crontab_t,$2)

	domain_use_interactive_fds($1_crontab_t)

	files_read_etc_files($1_crontab_t)
	files_dontaudit_search_pids($1_crontab_t)

	libs_use_ld_so($1_crontab_t)
	libs_use_shared_libs($1_crontab_t)

	logging_send_syslog_msg($1_crontab_t)

	miscfiles_read_localization($1_crontab_t)

	seutil_read_config($1_crontab_t)

	userdom_manage_user_tmp_dirs($1,$1_crontab_t)
	userdom_manage_user_tmp_files($1,$1_crontab_t)
	# Access terminals.
	userdom_use_user_terminals($1,$1_crontab_t)
	# Read user crontabs
	userdom_read_user_home_content_files($1,$1_crontab_t)

	tunable_policy(`fcron_crond', `
		# fcron wants an instant update of a crontab change for the administrator
		# also crontab does a security check for crontab -u
		dontaudit $1_crontab_t crond_t:process signal;
	')

	ifdef(`TODO',`
	allow $1_crond_t tmp_t:dir rw_dir_perms;
	type_transition $1_crond_t $1_tmp_t:{ file dir } $1_tmp_t;

	# Read user crontabs
	dontaudit $1_crontab_t $1_home_dir_t:dir write;
	') dnl endif TODO
')

#######################################
## <summary>
##	The administrative functions template for the cron module.
## </summary>
## <desc>
##	<p>
##	This template creates rules for administrating the cron service,
##	allowing the specified user to manage other user crontabs.
##	</p>
## </desc>
## <param name="userdomain_prefix">
##	<summary>
##	The prefix of the user domain (e.g., user
##	is the prefix for user_t).
##	</summary>
## </param>
#
template(`cron_admin_template',`
	gen_require(`
		attribute cron_spool_type;
		type $1_crontab_t, $1_crond_t;
	')

	# Allow our crontab domain to unlink a user cron spool file.
	allow $1_crontab_t cron_spool_type:file { getattr read unlink };

	logging_read_generic_logs($1_crond_t)

	# Manipulate other users crontab.
	selinux_get_fs_mount($1_crontab_t)
	selinux_validate_context($1_crontab_t)
	selinux_compute_access_vector($1_crontab_t)
	selinux_compute_create_context($1_crontab_t)
	selinux_compute_relabel_context($1_crontab_t)
	selinux_compute_user_contexts($1_crontab_t)

	tunable_policy(`fcron_crond', `
		# fcron wants an instant update of a crontab change for the administrator
		# also crontab does a security check for crontab -u
		allow $1_crontab_t self:process setfscreate;
		selinux_get_fs_mount($1_crontab_t)
	')
')

########################################
## <summary>
##	Make the specified program domain accessable
##	from the system cron jobs.
## </summary>
## <param name="domain">
##	<summary>
##	The type of the process to transition to.
##	</summary>
## </param>
## <param name="entrypoint">
##	<summary>
##	The type of the file used as an entrypoint to this domain.
##	</summary>
## </param>
#
interface(`cron_system_entry',`
	gen_require(`
		type crond_t, system_crond_t;
	')

	domain_auto_trans(system_crond_t, $2, $1)

	# cjp: perhaps these four rules from the old
	# domain_auto_trans are not needed?
	allow system_crond_t $1:fd use;
	allow $1 system_crond_t:fd use;
	allow $1 system_crond_t:fifo_file rw_file_perms;
	allow $1 system_crond_t:process sigchld;

	allow $1 crond_t:fifo_file rw_file_perms;
	allow $1 crond_t:fd use;
	allow $1 crond_t:process sigchld;
')

########################################
## <summary>
##	Inherit and use a file descriptor
##	from the cron daemon.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`cron_use_fds',`
	gen_require(`
		type crond_t;
	')

	allow $1 crond_t:fd use;
')

########################################
## <summary>
##	Send a SIGCHLD signal to the cron daemon.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`cron_sigchld',`
	gen_require(`
		type crond_t;
	')

	allow $1 crond_t:process sigchld;
')

########################################
## <summary>
##	Read a cron daemon unnamed pipe.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`cron_read_pipes',`
	gen_require(`
		type crond_t;
	')

	allow $1 crond_t:fifo_file r_file_perms;
')

########################################
## <summary>
##	Do not audit attempts to write cron daemon unnamed pipes.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`cron_dontaudit_write_pipes',`
	gen_require(`
		type crond_t;
	')

	dontaudit $1 crond_t:fifo_file write;
')

########################################
## <summary>
##	Read and write a cron daemon unnamed pipe.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`cron_rw_pipes',`
	gen_require(`
		type crond_t;
	')

	allow $1 crond_t:fifo_file { getattr read write };
')

########################################
## <summary>
##	Read, and write cron daemon TCP sockets.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`cron_rw_tcp_sockets',`
	gen_require(`
		type crond_t;
	')

	allow $1 crond_t:tcp_socket { read write };
')

########################################
## <summary>
##	Search the directory containing user cron tables.
## </summary>
## <param name="domain">
##	<summary>
##	The type of the process to performing this action.
##	</summary>
## </param>
#
interface(`cron_search_spool',`
	gen_require(`
		type cron_spool_t;
	')

	files_search_spool($1)
	allow $1 cron_spool_t:dir search;
')

########################################
## <summary>
##	Execute APM in the apm domain.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`cron_anacron_domtrans_system_job',`
	gen_require(`
		type system_crond_t, anacron_exec_t;
	')

	domain_auto_trans($1,anacron_exec_t,system_crond_t)

	allow $1 system_crond_t:fd use;
	allow system_crond_t $1:fd use;
	allow system_crond_t $1:fifo_file rw_file_perms;
	allow system_crond_t $1:process sigchld;
')

########################################
## <summary>
##	Inherit and use a file descriptor
##	from system cron jobs.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`cron_use_system_job_fds',`
	gen_require(`
		type system_crond_t;
	')

	allow $1 system_crond_t:fd use;
')

########################################
## <summary>
##	Write a system cron job unnamed pipe.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`cron_write_system_job_pipes',`
	gen_require(`
		type system_crond_t;
	')

	allow $1 system_crond_t:file write;
')

########################################
## <summary>
##	Read and write a system cron job unnamed pipe.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`cron_rw_system_job_pipes',`
	gen_require(`
		type system_crond_t;
	')

	allow $1 system_crond_t:fifo_file rw_file_perms;
')

########################################
## <summary>
##	Read temporary files from the system cron jobs.
## </summary>
## <param name="domain">
##	<summary>
##	Domain allowed access.
##	</summary>
## </param>
#
interface(`cron_read_system_job_tmp_files',`
	gen_require(`
		type system_crond_tmp_t;
	')

	files_search_tmp($1)
	allow $1 system_crond_tmp_t:file r_file_perms;
')

########################################
## <summary>
##	Do not audit attempts to append temporary
##	files from the system cron jobs.
## </summary>
## <param name="domain">
##	<summary>
##	Domain to not audit.
##	</summary>
## </param>
#
interface(`cron_dontaudit_append_system_job_tmp_files',`
	gen_require(`
		type system_crond_tmp_t;
	')

	dontaudit $1 system_crond_tmp_t:file append;
')