selinux-policy/refpolicy/policy/modules/services/mta.te

policy_module(mta,1.0)

########################################
#
# Declarations
#

type etc_aliases_t;
files_make_file(etc_aliases_t)

type etc_mail_t;
files_make_file(etc_mail_t)

attribute mailserver_domain;

type mqueue_spool_t;
files_make_file(mqueue_spool_t)

type mail_spool_t;
files_make_file(mail_spool_t)

type sendmail_exec_t;
files_make_file(sendmail_exec_t)

type system_mail_t; #, user_mail_domain, nscd_client_domain;
domain_make_domain(system_mail_t)
role system_r types system_mail_t;

tunable_policy(`targeted_policy',`',`
optional_policy(`sendmail.te', `
domain_make_entrypoint_file(system_mail_t,sendmail_exec_t)
', `
init_make_system_domain(system_mail_t,sendmail_exec_t)
') dnl end if sendmail
') dnl end targeted_policy

########################################
#
# System mail local policy
#

allow system_mail_t self:capability { setuid setgid chown };
allow system_mail_t self:process { sigkill sigstop signull signal setrlimit };

allow system_mail_t self:tcp_socket { create connect ioctl read getattr write setattr append bind getopt setopt shutdown };

# re-exec itself
allow system_mail_t sendmail_exec_t:file { getattr read execute execute_no_trans };
allow system_mail_t sendmail_exec_t:lnk_file { getattr read };

kernel_read_kernel_sysctl(system_mail_t)
kernel_read_system_state(system_mail_t)
kernel_read_network_state(system_mail_t)

corenetwork_sendrecv_tcp_on_all_interfaces(system_mail_t)
corenetwork_sendrecv_raw_on_all_interfaces(system_mail_t)
corenetwork_sendrecv_tcp_on_all_nodes(system_mail_t)
corenetwork_sendrecv_raw_on_all_nodes(system_mail_t)
corenetwork_bind_tcp_on_all_nodes(system_mail_t)
corenetwork_sendrecv_tcp_on_all_ports(system_mail_t)

devices_get_pseudorandom_data(system_mail_t)

filesystem_get_persistent_filesystem_attributes(system_mail_t)

init_script_use_pseudoterminal(system_mail_t)

files_read_runtime_system_config(system_mail_t)
files_read_general_system_config(system_mail_t)
# It wants to check for nscd
files_ignore_search_runtime_data_directory(system_mail_t)

corecommands_execute_general_programs(system_mail_t)

libraries_use_dynamic_loader(system_mail_t)
libraries_use_shared_libraries(system_mail_t)

logging_send_system_log_message(system_mail_t)

miscfiles_read_localization(system_mail_t)

sysnetwork_read_network_config(system_mail_t)

tunable_policy(`use_dns',`
	allow system_mail_t self:udp_socket { create ioctl read getattr write setattr append bind getopt setopt shutdown connect };
	corenetwork_sendrecv_udp_on_all_interfaces(system_mail_t)
	corenetwork_sendrecv_udp_on_all_nodes(system_mail_t)
	corenetwork_bind_udp_on_all_nodes(system_mail_t)
	corenetwork_sendrecv_udp_on_dns_port(system_mail_t)
')

optional_policy(`procmail.te',`
	procmail_execute(system_mail_t)
')

ifdef(`TODO',`

optional_policy(`sendmail.te',`
allow system_mail_t etc_mail_t:dir { getattr search };
allow system_mail_t etc_runtime_t:file { getattr read };
allow system_mail_t proc_t:dir search;
allow system_mail_t proc_t:file { getattr read };
allow system_mail_t proc_t:lnk_file read;
dontaudit system_mail_t proc_net_t:dir search;
allow system_mail_t fs_t:filesystem getattr;
allow system_mail_t var_t:dir getattr;
allow system_mail_t var_spool_t:dir getattr;
dontaudit system_mail_t userpty_type:chr_file { getattr read write };

# sendmail -q 
allow system_mail_t mqueue_spool_t:dir rw_dir_perms;
allow system_mail_t mqueue_spool_t:file create_file_perms;

ifdef(`crond.te', `
dontaudit system_mail_t system_crond_tmp_t:file append;
')
') dnl end if sendmail


can_ypbind(system_mail_t)

allow system_mail_t device_t:dir search;
allow system_mail_t { var_t var_spool_t }:dir search;
allow system_mail_t sbin_t:dir search;

# Transition from a system domain to the derived domain.
domain_auto_trans(privmail, sendmail_exec_t, system_mail_t)
allow privmail sendmail_exec_t:lnk_file { getattr read };

ifdef(`crond.te', `
# Read cron temporary files.
allow system_mail_t system_crond_tmp_t:file { read getattr ioctl };
allow mta_user_agent system_crond_tmp_t:file { read getattr };
')

ifdef(`qmail.te', `
allow system_mail_t qmail_etc_t:dir search;
allow system_mail_t qmail_etc_t:{ file lnk_file } read;
')dnl end if qmail

ifdef(`targeted_policy', `
# rules are currently defined in sendmail.te, but it is not included in 
# targeted policy.  We could move these rules permanantly here.

ifdef(`postfix.te', `', `
domain_execute_all_entrypoint_programs(system_mail_t)
files_execute_system_config_script(system_mail_t)
corecommands_execute_general_programs(system_mail_t)
corecommands_execute_system_programs(system_mail_t)
libraries_use_dynamic_loader(system_mail_t)
libraries_use_shared_libraries(system_mail_t)
libraries_execute_dynamic_loader(system_mail_t)
libraries_execute_library_scripts(system_mail_t)
')

allow system_mail_t { var_t var_spool_t }:dir getattr;

allow system_mail_t mqueue_spool_t:dir { create read getattr lock setattr ioctl link unlink rename search add_name remove_name reparent write rmdir };
allow system_mail_t mqueue_spool_t:file { create ioctl read getattr lock write setattr append link unlink rename };
allow system_mail_t mqueue_spool_t:lnk_file { create read getattr setattr link unlink rename };

allow system_mail_t mail_spool_t:dir { create read getattr lock setattr ioctl link unlink rename search add_name remove_name reparent write rmdir };
allow system_mail_t mail_spool_t:file { create ioctl read getattr lock write setattr append link unlink rename };
allow system_mail_t mail_spool_t:lnk_file { create read getattr setattr link unlink rename };

allow system_mail_t mail_spool_t:fifo_file rw_file_perms;
allow system_mail_t etc_mail_t:file { getattr read };
', ` dnl if not targeted policy:
optional_policy(`sendmail.te', `
# sendmail has an ugly design, the one process parses input from the user and
# then does system things with it.
domain_auto_trans(initrc_t, sendmail_exec_t, sendmail_t)
')

# allow the sysadmin to do "mail someone < /home/user/whatever"
allow sysadm_mail_t user_home_dir_type:dir search;
r_dir_file(sysadm_mail_t, user_home_type)
') dnl end ifdef targeted_policy

# for a mail server process that does things in response to a user command
allow mta_user_agent userdomain:process sigchld;
allow mta_user_agent { userdomain privfd }:fd use;
ifdef(`crond.te', `
allow mta_user_agent crond_t:process sigchld;
')
allow mta_user_agent sysadm_t:fifo_file { read write };

allow { system_mail_t mta_user_agent } privmail:fd use;
allow { system_mail_t mta_user_agent } privmail:process sigchld;
allow { system_mail_t mta_user_agent } privmail:fifo_file { read write };
allow { system_mail_t mta_user_agent } admin_tty_type:chr_file { read write };

ifdef(`arpwatch.te', `
# why is mail delivered to a directory of type arpwatch_data_t?
allow mta_delivery_agent arpwatch_data_t:dir search;
allow { system_mail_t mta_user_agent } arpwatch_tmp_t:file rw_file_perms;
ifdef(`hide_broken_symptoms', `
dontaudit { system_mail_t mta_user_agent } arpwatch_t:packet_socket { read write };
')
')dnl end if arpwatch.te

allow mta_delivery_agent home_root_t:dir { getattr search };

# for /var/spool/mail
ra_dir_create_file(mta_delivery_agent, mail_spool_t)

# for piping mail to a command
can_exec(mta_delivery_agent, shell_exec_t)
allow mta_delivery_agent bin_t:dir search;
allow mta_delivery_agent bin_t:lnk_file read;
allow mta_delivery_agent { etc_runtime_t proc_t }:file { getattr read };

# Transition from a system domain to the derived domain.
domain_auto_trans(privmail, sendmail_exec_t, system_mail_t)
allow privmail sendmail_exec_t:lnk_file { getattr read };

ifdef(`crond.te', `
# Read cron temporary files.
allow system_mail_t system_crond_tmp_t:file { read getattr ioctl };
allow mta_user_agent system_crond_tmp_t:file { read getattr };
')

') dnl end TODO