policy_module(milter, 1.5.0)

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

# attributes common to all milters
attribute milter_domains;
attribute milter_data_type;

# support for dkim-milter - domainKeys Identified Mail sender authentication sendmail milter
milter_template(dkim)

# type for the private key of dkim-milter
type dkim_milter_private_key_t;
files_type(dkim_milter_private_key_t)

type dkim_milter_tmp_t;
files_tmp_file(dkim_milter_tmp_t)

# currently-supported milters are milter-greylist, milter-regex and spamass-milter
milter_template(greylist)
milter_template(regex)
milter_template(spamass)

# Type for the spamass-milter home directory, under which spamassassin will
# store system-wide preferences, bayes databases etc. if not configured to
# use per-user configuration
type spamass_milter_state_t;
files_type(spamass_milter_state_t)


#######################################
#
# milter domains local policy
#

# Allow communication with MTA over a unix-domain socket
# Note: usage with TCP sockets requires additional policy

allow milter_domains self:fifo_file rw_fifo_file_perms;

allow milter_domains self:process signull;

# Allow communication with MTA over a TCP socket
allow milter_domains self:tcp_socket create_stream_socket_perms;

kernel_dontaudit_read_system_state(milter_domains)

corenet_tcp_bind_generic_node(milter_domains)
corenet_tcp_bind_milter_port(milter_domains)

dev_read_rand(milter_domains)
dev_read_urand(milter_domains)

mta_read_config(milter_domains)

sysnet_read_config(greylist_milter_t)

#######################################
#
# dkim-milter local policy
#

allow dkim_milter_t self:capability { kill setgid setuid };
allow dkim_milter_t self:process { signal setrlimit };
allow dkim_milter_t self:tcp_socket create_stream_socket_perms;
allow dkim_milter_t self:unix_stream_socket create_stream_socket_perms;

read_files_pattern(dkim_milter_t, dkim_milter_private_key_t, dkim_milter_private_key_t)

manage_files_pattern(dkim_milter_t, dkim_milter_tmp_t, dkim_milter_tmp_t)
manage_dirs_pattern(dkim_milter_t, dkim_milter_tmp_t, dkim_milter_tmp_t)
files_tmp_filetrans(dkim_milter_t, dkim_milter_tmp_t, { dir file })

fs_getattr_xattr_fs(dkim_milter_t)

kernel_read_kernel_sysctls(dkim_milter_t)

corecmd_exec_shell(dkim_milter_t)

corenet_tcp_connect_smtp_port(dkim_milter_t)
corenet_udp_bind_all_ports(dkim_milter_t)

auth_use_nsswitch(dkim_milter_t)

sysnet_dns_name_resolve(dkim_milter_t)

optional_policy(`
	mta_manage_queue(dkim_milter_t)
	mta_sendmail_exec(dkim_milter_t)
')

optional_policy(`
	sendmail_domtrans(dkim_milter_t)
')

########################################
#
# milter-greylist local policy
#   ensure smtp clients retry mail like real MTAs and not spamware
#   http://hcpnet.free.fr/milter-greylist/
#

# It removes any existing socket (not owned by root) whilst running as root,
# fixes permissions, renices itself and then calls setgid() and setuid() to
# drop privileges
allow greylist_milter_t self:capability { chown dac_read_search  setgid setuid sys_nice };
allow greylist_milter_t self:process { setsched getsched };

allow greylist_milter_t self:tcp_socket create_stream_socket_perms;

# It creates a pid file /var/run/milter-greylist.pid
files_pid_filetrans(greylist_milter_t, greylist_milter_data_t, file)

kernel_read_kernel_sysctls(greylist_milter_t)
kernel_read_network_state(greylist_milter_t)

corecmd_exec_bin(greylist_milter_t)
corecmd_exec_shell(greylist_milter_t)

corenet_tcp_bind_movaz_ssc_port(greylist_milter_t)
corenet_tcp_connect_movaz_ssc_port(greylist_milter_t)
corenet_tcp_bind_rtsclient_port(greylist_milter_t)

# perl getgroups() reads a bunch of files in /etc
# Allow the milter to read a GeoIP database in /usr/share
# The milter runs from /var/lib/milter-greylist and maintains files there
files_search_var_lib(greylist_milter_t)

# Look up username for dropping privs
auth_use_nsswitch(greylist_milter_t)

optional_policy(`
	mysql_stream_connect(greylist_milter_t)
')

########################################
#
# milter-regex local policy
#   filter emails using regular expressions
#   http://www.benzedrine.cx/milter-regex.html
#

# It removes any existing socket (not owned by root) whilst running as root
# and then calls setgid() and setuid() to drop privileges
allow regex_milter_t self:capability { setuid setgid dac_read_search  };

# The milter's socket directory lives under /var/spool
files_search_spool(regex_milter_t)

# Look up username for dropping privs
auth_use_nsswitch(regex_milter_t)

########################################
#
# spamass-milter local policy
#   pipe emails through SpamAssassin
#   http://savannah.nongnu.org/projects/spamass-milt/
#

# The milter runs from /var/lib/spamass-milter
allow spamass_milter_t spamass_milter_state_t:dir search_dir_perms;
files_search_var_lib(spamass_milter_t)

kernel_read_system_state(spamass_milter_t)

# When used with -b or -B options, the milter invokes sendmail to send mail
# to a spamtrap address, using popen()
corecmd_exec_shell(spamass_milter_t)
corecmd_read_bin_symlinks(spamass_milter_t)
corecmd_search_bin(spamass_milter_t)

auth_use_nsswitch(spamass_milter_t)

mta_send_mail(spamass_milter_t)

# The main job of the milter is to pipe spam through spamc and act on the result
optional_policy(`
	spamassassin_domtrans_client(spamass_milter_t)
')