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>
##	Basic mail transfer agent domain template.
## </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 is the basic types and rules, common
##	to the system agent and user agents.
##	</p>
## </desc>
## <param name="domain_prefix">
##	The prefix of the domain (e.g., user
##	is the prefix for user_t).
## </param>
#
template(`mta_base_mail_template',`

	gen_require(`
		attribute user_mail_domain;
		type sendmail_exec_t;
	')

	##############################
	#
	# $1_mail_t declarations
	#

	type $1_mail_t, user_mail_domain;
	domain_type($1_mail_t)
	domain_entry_file($1_mail_t,sendmail_exec_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;

	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_non_ipsec_sendrecv($1_mail_t)
	corenet_tcp_bind_all_nodes($1_mail_t)
	corenet_tcp_connect_all_ports($1_mail_t)
	corenet_tcp_connect_smtp_port($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)

	libs_use_ld_so($1_mail_t)
	libs_use_shared_libs($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)

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

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

	optional_policy(`postfix',`
		postfix_domtrans_user_mail_handler($1_mail_t)
	')

	optional_policy(`procmail',`
		procmail_exec($1_mail_t)
	')

	optional_policy(`sendmail',`
		gen_require(`
			type etc_mail_t, mail_spool_t, mqueue_spool_t;
		')

		allow $1_mail_t $1_mail_tmp_t:dir create_dir_perms;
		allow $1_mail_t $1_mail_tmp_t:file create_file_perms;
		files_filetrans_tmp($1_mail_t, $1_mail_tmp_t, { file dir })

		allow $1_mail_t etc_mail_t:dir { getattr search };

		# Write to /var/spool/mail and /var/spool/mqueue.
		allow $1_mail_t mail_spool_t:dir rw_dir_perms;
		allow $1_mail_t mail_spool_t:file create_file_perms;
		allow $1_mail_t mqueue_spool_t:dir rw_dir_perms;
		allow $1_mail_t mqueue_spool_t:file create_file_perms;

		# Check available space.
		fs_getattr_xattr_fs($1_mail_t)

		files_read_etc_runtime_files($1_mail_t)

		# Write to /var/log/sendmail.st
		sendmail_manage_log($1_mail_t)
		sendmail_create_log($1_mail_t)
	')

	ifdef(`TODO',`
	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
')

#######################################
## <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;
		attribute mailserver_delivery, user_mail_domain;
		type sendmail_exec_t;
	')

	mta_base_mail_template($1)
	role $3 types $1_mail_t;

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

	# 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 };

	domain_use_wide_inherit_fd($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)
	# Create dead.letter in user home directories.
	userdom_manage_user_home_subdir_files($1,$1_mail_t)
	userdom_create_user_home($1,$1_mail_t,file)
	# for reading .forward - maybe we need a new type for it?
	# also for delivering mail to maildir
	userdom_manage_user_home_subdirs($1,mailserver_delivery)
	userdom_manage_user_home_subdir_files($1,mailserver_delivery)
	userdom_manage_user_home_subdir_symlinks($1,mailserver_delivery)
	userdom_manage_user_home_subdir_pipes($1,mailserver_delivery)
	userdom_manage_user_home_subdir_sockets($1,mailserver_delivery)
	userdom_create_user_home($1,mailserver_delivery,{ dir file lnk_file fifo_file sock_file })

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

	optional_policy(`postfix',`
		allow $1_mail_t self:capability dac_override;
		postfix_read_config($1_mail_t)
		postfix_list_spool($1_mail_t)
	')

	ifdef(`TODO',`
	# 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;
	')

	allow mta_user_agent $1_tmp_t:file r_file_perms;

	# 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;
	') dnl end TODO
')

########################################
## <summary>
##	Provide extra permissions for admin users
##	mail domain.
## </summary>
## <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>
#
template(`mta_admin_template',`
	ifdef(`strict_policy',`
		# allow the sysadmin to do "mail someone < /home/user/whatever"
		userdom_read_unpriv_user_home_files($1_mail_t)
	')

	optional_policy(`postfix',`
		gen_require(`
			attribute mta_user_agent;
			type etc_aliases_t;
		')

		allow mta_user_agent $2:fifo_file { read write };

		allow $1_mail_t etc_aliases_t:dir create_dir_perms;
		allow $1_mail_t etc_aliases_t:file create_file_perms;
		allow $1_mail_t etc_aliases_t:lnk_file create_lnk_perms;
		allow $1_mail_t etc_aliases_t:sock_file create_file_perms;
		allow $1_mail_t etc_aliases_t:fifo_file create_file_perms;
		files_filetrans_etc($1_mail_t,etc_aliases_t,{ file lnk_file sock_file fifo_file })

		# postfix needs this for newaliases
		files_getattr_tmp_dir($1_mail_t)

		postfix_exec_master($1_mail_t)

		ifdef(`distro_redhat',`
			# compatability for old default main.cf
			postfix_filetrans_config($1_mail_t,etc_aliases_t,{ dir file lnk_file sock_file fifo_file })
		')
	')
')

#######################################
#
# 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;
		type mail_spool_t;
	')

	typeattribute $1 mailserver_delivery;

	allow $1 mail_spool_t:dir ra_dir_perms;
	allow $1 mail_spool_t:file { create ioctl read getattr lock append };
	allow $1 mail_spool_t:lnk_file { create read getattr };

	optional_policy(`dovecot',`
		dovecot_manage_spool($1)
	')

	optional_policy(`mailman',`
		# 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',`
		# 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(`
		attribute mta_user_agent;
		type system_mail_t, sendmail_exec_t;
	')

	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;

	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 server configuration.
## </summary>
## <param name="domain">
##	Domain allowed access.
## </param>
#
interface(`mta_read_config',`
	gen_require(`
		type etc_mail_t;
	')

	files_search_etc($1)
	allow $1 etc_mail_t:dir list_dir_perms;
	allow $1 etc_mail_t:file r_file_perms;
	allow $1 etc_mail_t:lnk_file { getattr read };
')

########################################
## <summary>
##	Read mail address aliases.
## </summary>
## <param name="domain">
##	Domain allowed access.
## </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;
')

########################################
## <summary>
##	Type transition files created in /etc
##	to the mail address aliases type.
## </summary>
## <param name="domain">
##	Domain allowed access.
## </param>
#
interface(`mta_filetrans_etc_aliases',`
	gen_require(`
		type etc_aliases_t;
	')

	files_filetrans_etc($1,etc_aliases_t, file)
')

#######################################
#
# 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 $1 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;
')

#######################################
## <summary>
##	Create private objects in the 
##	mail spool directory.
## </summary>
## <param name="domain">
##	Domain allowed access.
## </param>
## <param name="private type">
##	The type of the object to be created.
## </param>
## <param name="object" optional="true">
##	The object class of the object being created.  If
##	no class is specified, file will be used.
## </param>
#
interface(`mta_filetrans_spool',`
	gen_require(`
		type mail_spool_t;
	')

	files_search_spool($1)
	allow $1 mail_spool_t:dir rw_dir_perms;

	ifelse(`$3',`',`
		type_transition $1 mail_spool_t:file $2;
	',`
		type_transition $1 mail_spool_t:$3 $2;
	')
')

#######################################
#
# 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;
')

#######################################
## <summary>
##	Delete from the mail spool.
## </summary>
## <param name="domain">
##	Domain allowed access.
## </param>
#
interface(`mta_delete_spool',`
	gen_require(`
		type mail_spool_t;
	')

	files_search_spool($1)
	allow $1 mail_spool_t:dir { list_dir_perms write remove_name };
	allow $1 mail_spool_t:file unlink;
')

#######################################
#
# mta_manage_spool(domain)
#
interface(`mta_manage_spool',`
	gen_require(`
		type mail_spool_t;
	')

	files_search_spool($1)
	allow $1 mail_spool_t:dir manage_dir_perms;
	allow $1 mail_spool_t:lnk_file create_lnk_perms;
	allow $1 mail_spool_t:file manage_file_perms;
')

#######################################
## <summary>
##	Do not audit attempts to read and
##	write the mail queue.
## </summary>
## <param name="domain">
##	Domain to not audit.
## </param>
#
interface(`mta_dontaudit_rw_queue',`
	gen_require(`
		type mqueue_spool_t;
	')

	dontaudit $1 mqueue_spool_t:file { getattr read write };
')

#######################################
#
# 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;
')

#######################################
## <summary>
##	Read sendmail binary.
## </summary>
## <param name="domain">
##	Domain allowed access.
## </param>
#
# cjp: added for postfix
interface(`mta_read_sendmail_bin',`
	gen_require(`
		type sendmail_exec_t;
	')

	allow $1 sendmail_exec_t:file r_file_perms;
')

#######################################
## <summary>
##	Read and write unix domain stream sockets
##	of user mail domains.
## </summary>
## <param name="domain">
##	Domain allowed access.
## </param>
#
interface(`mta_rw_user_mail_stream_socket',`
	gen_require(`
		attribute user_mail_domain;
	')

	allow $1 user_mail_domain:unix_stream_socket rw_socket_perms;
')