b13921c3f0
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 15715aea32)
46 lines
1.8 KiB
Text
46 lines
1.8 KiB
Text
typeattribute netd coredomain;
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typeattribute netd bpfdomain;
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init_daemon_domain(netd)
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# Allow netd to spawn dnsmasq in it's own domain
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domain_auto_trans(netd, dnsmasq_exec, dnsmasq)
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allow netd { fs_bpf fs_bpf_netd_readonly fs_bpf_netd_shared }:dir search;
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allow netd { fs_bpf fs_bpf_netd_readonly fs_bpf_netd_shared }:file read;
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allow netd { fs_bpf fs_bpf_netd_shared }:file write;
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# give netd permission to setup iptables rule with xt_bpf, attach program to cgroup, and read/write
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# the map created by bpfloader
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allow netd bpfloader:bpf { prog_run map_read map_write };
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# in order to invoke side effect of close() on such a socket calling synchronize_rcu()
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# TODO: Remove this permission when 4.9 kernel is deprecated.
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# TODO: Remove this after we remove all bpf interactions from netd.
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allow netd self:key_socket create;
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set_prop(netd, ctl_mdnsd_prop)
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set_prop(netd, netd_stable_secret_prop)
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get_prop(netd, adbd_config_prop)
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get_prop(netd, bpf_progs_loaded_prop)
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get_prop(netd, hwservicemanager_prop)
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get_prop(netd, device_config_netd_native_prop)
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# Allow netd to write to statsd.
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unix_socket_send(netd, statsdw, statsd)
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# Allow netd to send callbacks to network_stack
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binder_call(netd, network_stack)
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# Allow netd to send dump info to dumpstate
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allow netd dumpstate:fd use;
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allow netd dumpstate:fifo_file { getattr write };
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# persist.netd.stable_secret contains RFC 7217 secret key which should never be
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# leaked to other processes. Make sure it never leaks.
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neverallow { domain -netd -init -dumpstate } netd_stable_secret_prop:file r_file_perms;
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# We want to ensure that no other process ever tries tampering with persist.netd.stable_secret,
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# the RFC 7217 secret key managed by netd. Doing so could compromise user privacy.
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neverallow { domain -netd -init } netd_stable_secret_prop:property_service set;
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