platform_system_sepolicy/private/netd.te

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typeattribute netd coredomain;
typeattribute netd bpfdomain;
init_daemon_domain(netd)
# Allow netd to spawn dnsmasq in it's own domain
domain_auto_trans(netd, dnsmasq_exec, dnsmasq)
much more finegrained bpf selinux privs for networking mainline Goal is to gain a better handle on who has access to which maps and to allow (with bpfloader changes to create in one directory and move into the target directory) per-map selection of selinux context, while still having reasonable defaults for stuff pinned directly into the target location. BPFFS (ie. /sys/fs/bpf) labelling is as follows: subdirectory selinux context mainline usecase / usable by / fs_bpf no (*) core operating system (ie. platform) /net_private fs_bpf_net_private yes, T+ network_stack /net_shared fs_bpf_net_shared yes, T+ network_stack & system_server /netd_readonly fs_bpf_netd_readonly yes, T+ network_stack & system_server & r/o to netd /netd_shared fs_bpf_netd_shared yes, T+ network_stack & system_server & netd [**] /tethering fs_bpf_tethering yes, S+ network_stack /vendor fs_bpf_vendor no, T+ vendor * initial support for bpf was added back in P, but things worked differently back then with no bpfloader, and instead netd doing stuff by hand, bpfloader with pinning into /sys/fs/bpf was (I believe) added in Q (and was definitely there in R) ** additionally bpf programs are accesible to netutils_wrapper for use by iptables xt_bpf extensions 'mainline yes' currently means shipped by the com.android.tethering apex, but this is really another case of bad naming, as it's really the 'networking/connectivity/tethering' apex / mainline module. Long term the plan is to merge a few other networking mainline modules into it (and maybe give it a saner name...). The reason for splitting net_private vs tethering is that: S+ must support 4.9+ kernels and S era bpfloader v0.2+ T+ must support 4.14+ kernels and T beta3 era bpfloader v0.13+ The kernel affects the intelligence of the in-kernel bpf verifier and the available bpf helper functions. Older kernels have a tendency to reject programs that newer kernels allow. / && /vendor are not shipped via mainline, so only need to work with the bpfloader that's part of the core os. Bug: 218408035 Test: TreeHugger, manually on cuttlefish Signed-off-by: Maciej Żenczykowski <maze@google.com> Change-Id: I674866ebe32aca4fc851818c1ffcbec12ac4f7d4 (cherry picked from commit 15715aea32b85c933778b97a46de6ccab42ca7fb)
2022-05-21 14:03:29 +02:00
allow netd { fs_bpf fs_bpf_netd_readonly fs_bpf_netd_shared }:dir search;
allow netd { fs_bpf fs_bpf_netd_readonly fs_bpf_netd_shared }:file { getattr read };
much more finegrained bpf selinux privs for networking mainline Goal is to gain a better handle on who has access to which maps and to allow (with bpfloader changes to create in one directory and move into the target directory) per-map selection of selinux context, while still having reasonable defaults for stuff pinned directly into the target location. BPFFS (ie. /sys/fs/bpf) labelling is as follows: subdirectory selinux context mainline usecase / usable by / fs_bpf no (*) core operating system (ie. platform) /net_private fs_bpf_net_private yes, T+ network_stack /net_shared fs_bpf_net_shared yes, T+ network_stack & system_server /netd_readonly fs_bpf_netd_readonly yes, T+ network_stack & system_server & r/o to netd /netd_shared fs_bpf_netd_shared yes, T+ network_stack & system_server & netd [**] /tethering fs_bpf_tethering yes, S+ network_stack /vendor fs_bpf_vendor no, T+ vendor * initial support for bpf was added back in P, but things worked differently back then with no bpfloader, and instead netd doing stuff by hand, bpfloader with pinning into /sys/fs/bpf was (I believe) added in Q (and was definitely there in R) ** additionally bpf programs are accesible to netutils_wrapper for use by iptables xt_bpf extensions 'mainline yes' currently means shipped by the com.android.tethering apex, but this is really another case of bad naming, as it's really the 'networking/connectivity/tethering' apex / mainline module. Long term the plan is to merge a few other networking mainline modules into it (and maybe give it a saner name...). The reason for splitting net_private vs tethering is that: S+ must support 4.9+ kernels and S era bpfloader v0.2+ T+ must support 4.14+ kernels and T beta3 era bpfloader v0.13+ The kernel affects the intelligence of the in-kernel bpf verifier and the available bpf helper functions. Older kernels have a tendency to reject programs that newer kernels allow. / && /vendor are not shipped via mainline, so only need to work with the bpfloader that's part of the core os. Bug: 218408035 Test: TreeHugger, manually on cuttlefish Signed-off-by: Maciej Żenczykowski <maze@google.com> Change-Id: I674866ebe32aca4fc851818c1ffcbec12ac4f7d4 (cherry picked from commit 15715aea32b85c933778b97a46de6ccab42ca7fb)
2022-05-21 14:03:29 +02:00
allow netd { fs_bpf fs_bpf_netd_shared }:file write;
# give netd permission to setup iptables rule with xt_bpf, attach program to cgroup, and read/write
# the map created by bpfloader
allow netd bpfloader:bpf { prog_run map_read map_write };
# in order to invoke side effect of close() on such a socket calling synchronize_rcu()
# TODO: Remove this permission when 4.9 kernel is deprecated.
# TODO: Remove this after we remove all bpf interactions from netd.
allow netd self:key_socket create;
set_prop(netd, ctl_mdnsd_prop)
set_prop(netd, netd_stable_secret_prop)
get_prop(netd, adbd_config_prop)
get_prop(netd, hwservicemanager_prop)
get_prop(netd, device_config_netd_native_prop)
# Allow netd to write to statsd.
unix_socket_send(netd, statsdw, statsd)
# Allow netd to send callbacks to network_stack
binder_call(netd, network_stack)
# Allow netd to send dump info to dumpstate
allow netd dumpstate:fd use;
allow netd dumpstate:fifo_file { getattr write };
# 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 -dumpstate } 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;