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

## <summary>Policy common to all email tranfer agents.</summary>

########################################
## <summary>
##	MTA stub interface.  No access allowed.
## </summary>
## <param name="domain" optional="true">
##	N/A
## </param>
#
interface(`mta_stub',`
	gen_require(`
		type sendmail_exec_t;
	')
')

#######################################
## <summary>
##	The per user domain template for the mta module.
## </summary>
## <desc>
##	<p>
##	This template creates a derived domain which is
##	a email transfer agent, which sends mail on
##	behalf of the user.
##	</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">
##	The prefix of the user domain (e.g., user
##	is the prefix for user_t).
## </param>
## <param name="user_domain">
##	The type of the user domain.
## </param>
## <param name="user_role">
##	The role associated with the user domain.
## </param>
#
template(`mta_per_userdomain_template',`
	gen_require(`
		attribute mailserver_domain, mta_user_agent;
		type sendmail_exec_t;
	')

	type $1_mail_t;
	domain_type($1_mail_t)
	role $3 types $1_mail_t;

	type $1_mail_tmp_t;
	files_tmp_file($1_mail_tmp_t)

	##############################
	#
	# $1_mail_t local policy
	#

	allow $1_mail_t self:capability { setuid setgid chown };
	allow $1_mail_t self:process { signal_perms setrlimit };
	allow $1_mail_t self:tcp_socket create_socket_perms;

	# re-exec itself
	can_exec($1_mail_t, sendmail_exec_t)
	allow $1_mail_t sendmail_exec_t:lnk_file r_file_perms;

	# Transition from the user domain to the derived domain.
	domain_auto_trans($2, sendmail_exec_t, $1_mail_t)
	allow $2 sendmail_exec_t:lnk_file { getattr read };

	allow $2 $1_mail_t:fd use;
	allow $1_mail_t $2:fd use;
	allow $1_mail_t $2:fifo_file rw_file_perms;
	allow $1_mail_t $2:process sigchld;

	# For when the user wants to send mail via port 25 localhost
	kernel_tcp_recvfrom($2)
	allow $2 mailserver_domain:tcp_socket { connectto recvfrom };
	allow mailserver_domain $2:tcp_socket { acceptfrom recvfrom };

	kernel_read_kernel_sysctl($1_mail_t)

	corenet_tcp_sendrecv_all_if($1_mail_t)
	corenet_raw_sendrecv_all_if($1_mail_t)
	corenet_tcp_sendrecv_all_nodes($1_mail_t)
	corenet_raw_sendrecv_all_nodes($1_mail_t)
	corenet_tcp_sendrecv_all_ports($1_mail_t)
	corenet_tcp_bind_all_nodes($1_mail_t)
	corenet_tcp_connect_all_ports($1_mail_t)

	domain_use_wide_inherit_fd($1_mail_t)

	libs_use_ld_so($1_mail_t)
	libs_use_shared_libs($1_mail_t)

	corecmd_exec_bin($1_mail_t)
	corecmd_search_sbin($1_mail_t)

	files_read_etc_files($1_mail_t)
	files_search_spool($1_mail_t)
	# It wants to check for nscd
	files_dontaudit_search_pids($1_mail_t)

	logging_send_syslog_msg($1_mail_t)

	miscfiles_read_localization($1_mail_t)

	sysnet_read_config($1_mail_t)
	sysnet_dns_name_resolve($1_mail_t)

	userdom_use_user_terminals($1,$1_mail_t)
	# Write to the user domain tty. cjp: why?
	userdom_use_user_terminals($1,mta_user_agent)

	tunable_policy(`use_samba_home_dirs',`
		fs_manage_cifs_files($1_mail_t)
		fs_manage_cifs_symlinks($1_mail_t)
	')

	optional_policy(`nis.te',`
		nis_use_ypbind($1_mail_t)
	')

	optional_policy(`nscd.te',`
		nscd_use_socket($1_mail_t)
	')

	ifdef(`TODO',`
	optional_policy(`procmail.te',`
		procmail_execute($1_mail_t)
	')

	# Read user temporary files.
	allow $1_mail_t $1_tmp_t:file r_file_perms;
	dontaudit $1_mail_t $1_tmp_t:file append;
	ifdef(`postfix.te',`
		# postfix seems to need write access if the file handle is opened read/write
		allow $1_mail_t $1_tmp_t:file write;
	')

	# cjp: why?
	allow mta_user_agent $1_tmp_t:file r_file_perms;

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

	# Create dead.letter in user home directories.
	file_type_auto_trans($1_mail_t, $1_home_dir_t, $1_home_t, file)
	# if you do not want to allow dead.letter then use the following instead
	#allow $1_mail_t { $1_home_dir_t $1_home_t }:dir r_dir_perms;
	#allow $1_mail_t $1_home_t:file r_file_perms;

	# for reading .forward - maybe we need a new type for it?
	# also for delivering mail to maildir
	file_type_auto_trans(mailserver_delivery, $1_home_dir_t, $1_home_t)

	ifdef(`qmail.te', `
		allow $1_mail_t qmail_etc_t:dir search;
		allow $1_mail_t qmail_etc_t:{ file lnk_file } read;
	')

	') dnl end TODO
')

#######################################
#
# mta_mailserver(domain,entrypointtype)
#
interface(`mta_mailserver',`
	gen_require(`
		attribute mailserver_domain;
	')

	# For when the user wants to send mail via port 25 localhost
	kernel_tcp_recvfrom($1)

	init_daemon_domain($1,$2)
	typeattribute $1 mailserver_domain;
')

########################################
## <summary>
##	Modified mailserver interface for
##	sendmail daemon use.
## </summary>
## <desc>
##	<p>
##	A modified MTA mail server interface for
##	the sendmail program.  It's design does
##	not fit well with policy, and using the
##	regular interface causes a type_transition
##	conflict if direct running of init scripts
##	is enabled.
##	</p>
##	<p>
##	This interface should most likely only be used
##	by the sendmail policy.
##	</p>
## </desc>
## <param name="domain">
##	The type to be used for the mail server.
## </param>
## <param name="entry_point">
##	The type to be used for the domain entry point program.
## </param>
interface(`mta_sendmail_mailserver',`
	gen_require(`
		attribute mailserver_domain;
		type sendmail_exec_t;
	')

	# For when the user wants to send mail via port 25 localhost
	kernel_tcp_recvfrom($1)

	init_system_domain($1,sendmail_exec_t)
	typeattribute $1 mailserver_domain;
')

#######################################
## <summary>
##	Make a type a mailserver type used
##	for sending mail.
## </summary>
## <param name="domain">
##	Mail server domain type used for sending mail.
## </param>
#
interface(`mta_mailserver_sender',`
	gen_require(`
		attribute mailserver_sender;
	')

	typeattribute $1 mailserver_sender;
')

#######################################
## <summary>
##	Make a type a mailserver type used
##	for delivering mail to local users.
## </summary>
## <param name="domain">
##	Mail server domain type used for delivering mail.
## </param>
#
interface(`mta_mailserver_delivery',`
	gen_require(`
		attribute mailserver_delivery;
	')

	typeattribute $1 mailserver_delivery;

	optional_policy(`mailman.te',`
		# so MTA can access /var/lib/mailman/mail/wrapper
		files_search_var_lib($1)

		mailman_domtrans($1)
		mailman_read_data_symlinks($1)
	')
')

#######################################
## <summary>
##	Make a type a mailserver type used
##	for sending mail on behalf of local
##	users to the local mail spool.
## </summary>
## <param name="domain">
##	Mail server domain type used for sending local mail.
## </param>
#
interface(`mta_mailserver_user_agent',`
	gen_require(`
		attribute mta_user_agent;
	')

	typeattribute $1 mta_user_agent;

	optional_policy(`apache.te',`
		# apache should set close-on-exec
		apache_dontaudit_rw_stream_socket($1)
		apache_dontaudit_rw_sys_script_stream_socket($1)
	')
')

#######################################
#
# mta_send_mail(domain)
#
interface(`mta_send_mail',`
	gen_require(`
		type system_mail_t, sendmail_exec_t;
		class lnk_file r_file_perms;
		class process sigchld;
		class fd use;
		class fifo_file rw_file_perms;
	')

	allow $1 sendmail_exec_t:lnk_file r_file_perms;
	domain_auto_trans($1, sendmail_exec_t, system_mail_t)

	allow $1 system_mail_t:fd use;
	allow system_mail_t $1:fd use;
	allow system_mail_t $1:fifo_file rw_file_perms;
	allow system_mail_t $1:process sigchld;

	ifdef(`TODO',`
	allow mta_user_agent $1:fd use;
	allow mta_user_agent $1:process sigchld;
	allow mta_user_agent $1:fifo_file { read write };
	')
')

#######################################
#
# mta_exec(domain)
#
interface(`mta_exec',`
	gen_require(`
		type sendmail_exec_t;
	')

	can_exec($1, sendmail_exec_t)
')

########################################
## <summary>
##	Read mail address aliases.
## </summary>
## <param name="domain">
##	The type of the process performing this action.
## </param>
#
interface(`mta_read_aliases',`
	gen_require(`
		type etc_aliases_t;
		class file r_file_perms;
	')

	files_search_etc($1)
	allow $1 etc_aliases_t:file r_file_perms;
')

#######################################
#
# mta_rw_aliases(domain)
#
interface(`mta_rw_aliases',`
	gen_require(`
		type etc_aliases_t;
		class file { rw_file_perms setattr };
	')

	files_search_etc($1)
	allow sendmail_t etc_aliases_t:file { rw_file_perms setattr };
')

#######################################
## <summary>
##	Do not audit attempts to read and write TCP
##	sockets of mail delivery domains.
## </summary>
## <param name="domain">
##	Mail server domain.
## </param>
#
interface(`mta_dontaudit_rw_delivery_tcp_socket',`
	gen_require(`
		attribute mailserver_delivery;
	')

	dontaudit $1 mailserver_delivery:tcp_socket { read write };
')

#######################################
## <summary>
##	Connect to all mail servers over TCP.
## </summary>
## <param name="domain">
##	Mail server domain.
## </param>
#
interface(`mta_tcp_connect_all_mailservers',`
	gen_require(`
		attribute mailserver_domain;
	')

	allow $1 mailserver_domain:tcp_socket { connectto recvfrom };
	allow mailserver_domain $1:tcp_socket { acceptfrom recvfrom };
	kernel_tcp_recvfrom($1)
')

#######################################
## <summary>
##	Do not audit attempts to read a symlink
##	in the mail spool.
## </summary>
## <param name="domain">
##	Domain allowed access.
## </param>
#
interface(`mta_dontaudit_read_spool_symlink',`
	gen_require(`
		type mail_spool_t;
		class lnk_file read;
	')

	dontaudit $1 mail_spool_t:lnk_file read;
')

#######################################
#
# mta_getattr_spool(domain)
#
interface(`mta_getattr_spool',`
	gen_require(`
		type mail_spool_t;
		class dir r_dir_perms;
		class file getattr;
		class lnk_file read;
	')

	files_search_spool($1)
	allow $1 mail_spool_t:dir r_dir_perms;
	allow $1 mail_spool_t:lnk_file read;
	allow $1 mail_spool_t:file getattr;
')

#######################################
#
# mta_rw_spool(domain)
#
interface(`mta_rw_spool',`
	gen_require(`
		type mail_spool_t;
		class dir r_dir_perms;
		class lnk_file { getattr read };
		class file { rw_file_perms setattr };
	')

	files_search_spool($1)
	allow $1 mail_spool_t:dir r_dir_perms;
	allow $1 mail_spool_t:lnk_file { getattr read };
	allow $1 mail_spool_t:file { rw_file_perms setattr };
')

#######################################
## <summary>
##	Create, read, and write the mail spool.
## </summary>
## <param name="domain">
##	Domain allowed access.
## </param>
#
interface(`mta_append_spool',`
	gen_require(`
		type mail_spool_t;
		class dir ra_dir_perms;
		class lnk_file { getattr read };
		class file create_file_perms;
	')

	files_search_spool($1)
	allow $1 mail_spool_t:dir ra_dir_perms;
	allow $1 mail_spool_t:lnk_file { getattr read };
	allow $1 mail_spool_t:file create_file_perms;
')

#######################################
#
# mta_manage_spool(domain)
#
interface(`mta_manage_spool',`
	gen_require(`
		type mail_spool_t;
		class dir rw_dir_perms;
		class lnk_file { getattr read };
		class file create_file_perms;
	')

	files_search_spool($1)
	allow $1 mail_spool_t:dir rw_dir_perms;
	allow $1 mail_spool_t:lnk_file { getattr read };
	allow $1 mail_spool_t:file create_file_perms;
')

#######################################
#
# mta_manage_queue(domain)
#
interface(`mta_manage_queue',`
	gen_require(`
		type mqueue_spool_t;
		class dir rw_dir_perms;
		class file create_file_perms;
	')

	files_search_spool($1)
	allow $1 mqueue_spool_t:dir rw_dir_perms;
	allow $1 mqueue_spool_t:file create_file_perms;
')