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

# Copyright (C) 2005 Tresys Technology, LLC

########################################
#
# cron_per_userdomain_template(domainprefix)
#

define(`cron_per_userdomain_template',`

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

type $1_crond_t; # user_crond_domain;
domain_make_domain($1_crond_t);
corecommands_make_shell_entrypoint($1_crond_t)
role $1_r types $1_crond_t;

type $1_crontab_t;
domain_make_domain($1_crontab_t)
domain_make_entrypoint_file($1_crontab_t,crontab_exec_t)
role $1_r types $1_crontab_t;

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

allow $1_crond_t self:capability dac_override;
allow $1_crond_t self:process { sigkill sigstop signull signal setsched };
allow $1_crond_t self:fifo_file { read getattr write append };
allow $1_crond_t self:unix_stream_socket { create ioctl read getattr write setattr append bind connect getopt setopt shutdown listen accept };
allow $1_crond_t self:unix_dgram_socket { create ioctl read getattr write setattr append bind connect getopt setopt shutdown };

# 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 };

kernel_read_system_state($1_crond_t)
kernel_read_kernel_sysctl($1_crond_t)

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

corenetwork_network_tcp_on_all_interfaces($1_crond_t)
corenetwork_network_raw_on_all_interfaces($1_crond_t)
corenetwork_network_udp_on_all_interfaces($1_crond_t)
corenetwork_network_tcp_on_all_nodes($1_crond_t)
corenetwork_network_raw_on_all_nodes($1_crond_t)
corenetwork_network_udp_on_all_nodes($1_crond_t)
corenetwork_network_tcp_on_all_ports($1_crond_t)
corenetwork_network_udp_on_all_ports($1_crond_t)
corenetwork_bind_tcp_on_all_nodes($1_crond_t)
corenetwork_bind_udp_on_all_nodes($1_crond_t)

devices_get_pseudorandom_data($1_crond_t)

filesystem_get_all_filesystems_attributes($1_crond_t)

domain_execute_all_entrypoint_programs($1_crond_t)

files_read_general_application_resources($1_crond_t)
files_execute_system_config_script($1_crond_t)
# for nscd:
files_ignore_search_runtime_data_directory($1_crond_t)

corecommands_execute_general_programs($1_crond_t)
corecommands_execute_system_programs($1_crond_t)

libraries_use_dynamic_loader($1_crond_t)
libraries_use_shared_libraries($1_crond_t)
libraries_execute_library_scripts($1_crond_t)
libraries_execute_dynamic_loader($1_crond_t)

files_read_runtime_system_config($1_crond_t)

logging_search_system_log_directory($1_crond_t)

selinux_read_config($1_crond_t)

miscfiles_read_localization($1_crond_t)

tunable_policy(`fcron_crond', `
allow crond_t $1_cron_spool_t:file { create ioctl read getattr lock write setattr append link unlink rename };
')

ifdef(`TODO',`
# Access user files and dirs.
allow $1_crond_t home_root_t:dir search;
file_type_auto_trans($1_crond_t, $1_home_dir_t, $1_home_t)

# Run scripts in user home directory and access shared libs.
can_exec($1_crond_t, $1_home_t)

file_type_auto_trans($1_crond_t, tmp_t, $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 { getattr read };

# $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;
')

# This domain is granted permissions common to most domains.
can_ypbind($1_crond_t)
allow $1_crond_t var_spool_t:dir search;
allow $1_crond_t var_t:dir r_dir_perms;
allow $1_crond_t var_t:file { getattr read ioctl };

# quiet other ps operations
dontaudit $1_crond_t domain:dir { getattr search };
') dnl endif TODO

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

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

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

# 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 { sigkill sigstop signull signal };

# create files in /var/spool/cron
allow $1_crontab_t $1_cron_spool_t:file { create ioctl read getattr lock write setattr append link unlink rename };
allow $1_crontab_t cron_spool_t:dir { getattr search read write add_name remove_name };
type_transition $1_crontab_t $1_cron_spool_t:file system_crond_tmp_t;

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

allow $1_crontab_t crond_log_t:file { getattr read append };

filesystem_get_persistent_filesystem_attributes($1_crontab_t)

domain_use_widely_inheritable_file_descriptors($1_crontab_t)

files_read_general_system_config($1_crontab_t)

libraries_use_dynamic_loader($1_crontab_t)
libraries_use_shared_libraries($1_crontab_t)

logging_send_system_log_message($1_crontab_t)

miscfiles_read_localization($1_crontab_t)

ifdef(`TODO',`

# Transition from the user domain to the derived domain.
domain_auto_trans($1_t, crontab_exec_t, $1_crontab_t)

can_ps($1_t, $1_crontab_t)

dontaudit $1_crontab_t proc_t:dir search;
dontaudit $1_crontab_t selinux_config_t:dir search;
# for the checks used by crontab -u
dontaudit $1_crontab_t security_t:dir search;

# Type for temporary files.
file_type_auto_trans($1_crontab_t, tmp_t, $1_tmp_t, { dir file })

# Use the type when creating files in /var/spool/cron.
allow sysadm_crontab_t $1_cron_spool_t:file { getattr read };

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
ifelse(`$1', `sysadm', `
allow $1_crontab_t self:process setfscreate;
kernel_get_selinuxfs_mount_point($1_crontab_t)
', `
dontaudit $1_crontab_t crond_t:process signal;
')dnl end ifelse
')dnl end ifdef fcron

# Run helper programs as $1_t
allow $1_crontab_t { bin_t sbin_t }:dir search;
allow $1_crontab_t bin_t:lnk_file read;
domain_auto_trans($1_crontab_t, { bin_t sbin_t shell_exec_t }, $1_t)

# Read user crontabs 
allow $1_crontab_t { $1_home_t $1_home_dir_t }:dir r_dir_perms;  
allow $1_crontab_t $1_home_t:file r_file_perms;  
dontaudit $1_crontab_t $1_home_dir_t:dir write;

# Access terminals.
allow $1_crontab_t devpts_t:dir { read search getattr };
allow $1_crontab_t $1_tty_device_t:chr_file { read write getattr ioctl };
allow $1_crontab_t $1_devpts_t:chr_file { read write getattr ioctl };

# Inherit and use descriptors from gnome-pty-helper.
ifdef(`gnome-pty-helper.te', `allow $1_crontab_t $1_gph_t:fd use;')

dontaudit $1_crontab_t var_run_t:dir search;
') dnl endif TODO
')

########################################
#
# cron_admin_template(domainprefix)
#

define(`cron_admin_template',`

logging_read_system_logs($1_crond_t)

# Allow our crontab domain to unlink a user cron spool file.
#allow $1_crontab_t user_cron_spool_t:file unlink;

# Manipulate other users crontab.
kernel_get_selinuxfs_mount_point($1_crontab_t)
kernel_validate_selinux_context($1_crontab_t)
kernel_compute_selinux_access_vector($1_crontab_t)
kernel_compute_selinux_create_context($1_crontab_t)
kernel_compute_selinux_relabel_context($1_crontab_t)
kernel_compute_selinux_reachable_user_contexts($1_crontab_t)
')

########################################
#
# cron_modify_log(domain)
#
define(`cron_modify_log',`
requires_block_template(`$0'_depend)
allow $1 crond_log_t:file { getattr read write ioctl lock append };
')

define(`cron_modify_log_depend',`
type crond_log_t;
class file rw_file_perms;
')