platform_system_sepolicy/public/netd.te

# network manager
type netd, domain, mlstrustedsubject;
type netd_exec, exec_type, file_type;

net_domain(netd)
# in addition to ioctls whitelisted for all domains, grant netd priv_sock_ioctls.
allowxperm netd self:udp_socket ioctl priv_sock_ioctls;

r_dir_file(netd, cgroup)
allow netd system_server:fd use;

allow netd self:capability { net_admin net_raw kill };
# Note: fsetid is deliberately not included above. fsetid checks are
# triggered by chmod on a directory or file owned by a group other
# than one of the groups assigned to the current process to see if
# the setgid bit should be cleared, regardless of whether the setgid
# bit was even set.  We do not appear to truly need this capability
# for netd to operate.
dontaudit netd self:capability fsetid;

allow netd self:netlink_kobject_uevent_socket create_socket_perms_no_ioctl;
allow netd self:netlink_route_socket nlmsg_write;
allow netd self:netlink_nflog_socket create_socket_perms_no_ioctl;
allow netd self:netlink_socket create_socket_perms_no_ioctl;
allow netd self:netlink_tcpdiag_socket { create_socket_perms_no_ioctl nlmsg_read nlmsg_write };
allow netd self:netlink_generic_socket create_socket_perms_no_ioctl;
allow netd self:netlink_netfilter_socket create_socket_perms_no_ioctl;
allow netd shell_exec:file rx_file_perms;
allow netd system_file:file x_file_perms;
not_full_treble(`allow netd vendor_file:file x_file_perms;')
allow netd devpts:chr_file rw_file_perms;

# Acquire advisory lock on /system/etc/xtables.lock
allow netd system_file:file lock;

r_dir_file(netd, proc_net)
# For /proc/sys/net/ipv[46]/route/flush.
allow netd proc_net:file rw_file_perms;

# Enables PppController and interface enumeration (among others)
r_dir_file(netd, sysfs_type)
# Allows setting interface MTU
allow netd sysfs:file write;

# TODO: added to match above sysfs rule. Remove me?
allow netd sysfs_usb:file write;

# TODO: netd previously thought it needed these permissions to do WiFi related
#       work.  However, after all the WiFi stuff is gone, we still need them.
#       Why?
allow netd self:capability { dac_override chown };

# Needed to update /data/misc/net/rt_tables
allow netd net_data_file:file create_file_perms;
allow netd net_data_file:dir rw_dir_perms;
allow netd self:capability fowner;

# Needed to lock the iptables lock.
allow netd system_file:file lock;

# Allow netd to spawn dnsmasq in it's own domain
allow netd dnsmasq:process signal;

# Allow netd to start clatd in its own domain
allow netd clatd:process signal;

set_prop(netd, ctl_mdnsd_prop)
set_prop(netd, netd_stable_secret_prop)

# Allow netd to publish a binder service and make binder calls.
binder_use(netd)
add_service(netd, netd_service)
allow netd dumpstate:fifo_file  { getattr write };

# Allow netd to call into the system server so it can check permissions.
allow netd system_server:binder call;
allow netd permission_service:service_manager find;

# Allow netd to talk to the framework service which collects netd events.
allow netd netd_listener_service:service_manager find;

# Allow netd to operate on sockets that are passed to it.
allow netd netdomain:{
  tcp_socket
  udp_socket
  rawip_socket
  tun_socket
} { read write getattr setattr getopt setopt };
allow netd netdomain:fd use;

# give netd permission to read and write netlink xfrm
allow netd self:netlink_xfrm_socket { create_socket_perms_no_ioctl nlmsg_write nlmsg_read };

# Allow netd to register as hal server.
add_hwservice(netd, system_net_netd_hwservice)
hwbinder_use(netd)
get_prop(netd, hwservicemanager_prop)

###
### Neverallow rules
###
### netd should NEVER do any of this

# Block device access.
neverallow netd dev_type:blk_file { read write };

# ptrace any other app
neverallow netd { domain }:process ptrace;

# Write to /system.
neverallow netd system_file:dir_file_class_set write;

# Write to files in /data/data or system files on /data
neverallow netd { app_data_file system_data_file }:dir_file_class_set write;

# only system_server and dumpstate may find netd service
neverallow { domain -system_server -dumpstate -netd } netd_service:service_manager find;

# apps may not interact with netd over binder.
neverallow appdomain netd:binder call;
neverallow netd { appdomain userdebug_or_eng(`-su') }:binder call;

# persist.netd.stable_secret contains RFC 7217 secret key which should never be
# leaked to other processes. Make sure it never leaks.
neverallow { domain -netd -init } netd_stable_secret_prop:file r_file_perms;

# We want to ensure that no other process ever tries tampering with persist.netd.stable_secret,
# the RFC 7217 secret key managed by netd. Doing so could compromise user privacy.
neverallow { domain -netd -init } netd_stable_secret_prop:property_service set;