# Copyright (C) 2005 Tresys Technology, LLC

policy_module(kernel,1.0)

# assertion related attributes
attribute can_load_policy;
attribute can_setenforce;
attribute can_setsecparam;
attribute can_load_kernmodule;
attribute can_receive_kernel_messages;

# constraint related attributes
attribute can_change_process_identity;
attribute can_change_process_role;
attribute can_change_object_identity;

#
# kernel_t is the domain of kernel threads.
# It is also the target type when checking permissions in the system class.
# 
type kernel_t, can_load_kernmodule, can_load_policy;
role system_r types kernel_t;
domain_make_domain(kernel_t)

#
# unlabeled_t is the type of unlabeled objects.
# Objects that have no known labeling information or that
# have labels that are no longer valid are treated as having this type.
#
type unlabeled_t;

# 
# security_t is the target type when checking
# the permissions in the security class.  It is also
# applied to selinuxfs inodes.
#
type security_t;
filesystem_make_filesystem(security_t)
genfscon selinuxfs / context_template(system_u:object_r:security_t,s0)

#
# sysfs_t is the type for /sys
#
type sysfs_t;
files_make_mountpoint(sysfs_t)
filesystem_make_filesystem(sysfs_t)
genfscon sysfs / context_template(system_u:object_r:sysfs_t,s0)

#
# usbfs_t is the type for /proc/bus/usb
#
type usbfs_t alias usbdevfs_t;
files_make_mountpoint(usbfs_t)
filesystem_make_filesystem(usbfs_t)
genfscon usbfs / context_template(system_u:object_r:usbfs_t,s0)
genfscon usbdevfs / context_template(system_u:object_r:usbfs_t,s0)

#
# Procfs types
#

type proc_t;
files_make_mountpoint(proc_t)
filesystem_make_filesystem(proc_t)
genfscon proc / context_template(system_u:object_r:proc_t,s0)
genfscon proc /sysvipc context_template(system_u:object_r:proc_t,s0)

# kernel message interface
type proc_kmsg_t;
genfscon proc /kmsg context_template(system_u:object_r:proc_kmsg_t,s0)
neverallow ~can_receive_kernel_messages proc_kmsg_t:file ~getattr;

# /proc kcore: inaccessible
type proc_kcore_t;
neverallow * proc_kcore_t:file ~getattr;
genfscon proc /kcore context_template(system_u:object_r:proc_kcore_t,s0)

type proc_mdstat_t;
genfscon proc /mdstat context_template(system_u:object_r:proc_mdstat_t,s0)

type proc_net_t;
genfscon proc /net context_template(system_u:object_r:proc_net_t,s0)

#
# Sysctl types
#

# /proc/irq directory and files
type sysctl_irq_t;
genfscon proc /irq context_template(system_u:object_r:sysctl_irq_t,s0)

# /proc/net/rpc directory and files
type sysctl_rpc_t;
genfscon proc /net/rpc context_template(system_u:object_r:sysctl_rpc_t,s0)

# /proc/sys directory, base directory of sysctls
type sysctl_t;
files_make_mountpoint(sysctl_t)
genfscon proc /sys context_template(system_u:object_r:sysctl_t,s0)

# /proc/sys/fs directory and files
type sysctl_fs_t;
files_make_mountpoint(sysctl_fs_t)
genfscon proc /sys/fs context_template(system_u:object_r:sysctl_fs_t,s0)

# /proc/sys/kernel directory and files
type sysctl_kernel_t;
genfscon proc /sys/kernel context_template(system_u:object_r:sysctl_kernel_t,s0)

# /proc/sys/kernel/modprobe file
type sysctl_modprobe_t;
genfscon proc /sys/kernel/modprobe context_template(system_u:object_r:sysctl_modprobe_t,s0)

# /proc/sys/kernel/hotplug file
type sysctl_hotplug_t;
genfscon proc /sys/kernel/hotplug context_template(system_u:object_r:sysctl_hotplug_t,s0)

# /proc/sys/net directory and files
type sysctl_net_t;
genfscon proc /sys/net context_template(system_u:object_r:sysctl_net_t,s0)

# /proc/sys/net/unix directory and files
type sysctl_net_unix_t;
genfscon proc /sys/net/unix context_template(system_u:object_r:sysctl_net_unix_t,s0)

# /proc/sys/vm directory and files
type sysctl_vm_t;
genfscon proc /sys/vm context_template(system_u:object_r:sysctl_vm_t,s0)

# /proc/sys/dev directory and files
type sysctl_dev_t;
genfscon proc /sys/dev context_template(system_u:object_r:sysctl_dev_t,s0)

########################################
#
# kernel local policy
#

# Use capabilities. need to investigate which capabilities are actually used
allow kernel_t self:capability *;

# Other possible mount points for the root fs are in files
allow kernel_t unlabeled_t:dir mounton;

# old general_domain_access()
allow kernel_t self:shm { associate getattr setattr create destroy read write lock unix_read unix_write };
allow kernel_t self:sem { associate getattr setattr create destroy read write unix_read unix_write };
allow kernel_t self:msg { send receive };
allow kernel_t self:msgq { associate getattr setattr create destroy read write enqueue unix_read unix_write };
allow kernel_t self:unix_dgram_socket { create ioctl read getattr write setattr append bind connect getopt setopt shutdown };
allow kernel_t self:unix_stream_socket { create ioctl read getattr write setattr append bind connect getopt setopt shutdown listen accept };
allow kernel_t self:unix_dgram_socket sendto;
allow kernel_t self:unix_stream_socket connectto;
allow kernel_t self:fifo_file { read getattr lock ioctl write append };
allow kernel_t self:fd use;

# old general_proc_read_access():
allow kernel_t proc_t:dir { getattr search read };
allow kernel_t proc_t:{ lnk_file file } { getattr read };
allow kernel_t proc_net_t:dir { getattr search read };
allow kernel_t proc_net_t:file { getattr read };
allow kernel_t proc_mdstat_t:file { getattr read }; 
allow kernel_t proc_kcore_t:file getattr;
allow kernel_t proc_kmsg_t:file getattr;
allow kernel_t sysctl_t:dir { getattr search read };
allow kernel_t sysctl_kernel_t:dir { getattr search read };
allow kernel_t sysctl_kernel_t:file { getattr read };

# old base_file_read_access():
files_list_home_directories(kernel_t)
files_read_general_application_resources(kernel_t)
selinux_read_config(kernel_t)

selinux_read_binary_policy(kernel_t)
allow kernel_t security_t:dir { read search getattr };
allow kernel_t security_t:file { getattr read write };
allow kernel_t security_t:security load_policy;
auditallow kernel_t security_t:security load_policy;

libraries_use_dynamic_loader(kernel_t)
libraries_use_shared_libraries(kernel_t)

corecommands_execute_shell(kernel_t)

terminal_use_console(kernel_t)
domain_signal_all_domains(kernel_t)

# Mount root file system.  Used when loading a policy
# from initrd, then mounting the root filesystem
filesystem_mount_all_filesystems(kernel_t)

# /proc/sys/kernel/modprobe is set to /bin/true if not using modules.
corecommands_execute_general_programs(kernel_t)

logging_send_system_log_message(kernel_t)

# Kernel-generated traffic, e.g. ICMP replies.
corenetwork_network_raw_on_all_interfaces(kernel_t)
corenetwork_network_raw_on_all_nodes(kernel_t)

# Kernel-generated traffic, e.g. TCP resets.
corenetwork_network_tcp_on_all_interfaces(kernel_t)
corenetwork_network_tcp_on_all_nodes(kernel_t)

neverallow ~can_load_policy security_t:security load_policy;
neverallow ~can_setenforce security_t:security setenforce;
neverallow ~can_setsecparam security_t:security setsecparam;

# enabling dyntransition breaks process tranquility.  If you dont
# know what this means or dont understand the implications of a
# dynamic transition, you shouldnt be using it!!!
neverallow * *:process { setcurrent dyntransition };

neverallow ~can_load_kernmodule *:capability sys_module;