Files in /proc/net leak information. This change is the first step in
determining which files apps may use, whitelisting benign access, and
otherwise removing access while providing safe alternative APIs.

To that end, this change:
* Introduces the proc_net_type attribute which will assigned to any
new SELinux types in /proc/net to avoid removing access to privileged
processes. These processes may be evaluated later, but are lower
priority than apps.
* Labels /proc/net/{tcp,tcp6,udp,udp6} as proc_net_vpn due to existing
use by VPN apps. This may be replaced by an alternative API.
* Audits all other proc/net access for apps.
* Audits proc/net access for other processes which are currently
granted broad read access to /proc/net but should not be including
storaged, zygote, clatd, logd, preopt2cachename and vold.

Bug: 9496886
Bug: 68016944
Test: Boot Taimen-userdebug. On both wifi and cellular: stream youtube
    navigate maps, send text message, make voice call, make video call.
    Verify no avc "granted" messages in the logs.
Test: A few VPN apps including "VPN Monster", "Turbo VPN", and
"Freighter". Verify no logspam with the current setup.
Test: atest CtsNativeNetTestCases
Test: atest netd_integration_test
Test: atest QtaguidPermissionTest
Test: atest FileSystemPermissionTest

Change-Id: I7e49f796a25cf68bc698c6c9206e24af3ae11457

Bug: 72177715
Test: flash device and check incident output
Change-Id: I16c172caec235d985a6767642134fbd5e5c23912
(cherry picked from commit 985db6d8)

Bug: 72177715
Test: flash device and check incident output
Change-Id: I16c172caec235d985a6767642134fbd5e5c23912

tagSocket() now results in netd performing these actions on behalf
of the calling process.

Remove direct access to:
/dev/xt_qtaguid
/proc/net/xt_qtaguid/ctrl

Bug: 68774956
Test: -m CtsAppSecurityHostTestCases -t android.appsecurity.cts.AppSecurityTests
    -m CtsNativeNetTestCases
Test: stream youtube, browse chrome
Test: go/manual-ab-ota
Change-Id: I6a044f304c3ec4e7c6043aebeb1ae63c9c5a0beb

Bug: 75968642
Test: manual testing to check for sepolicy violation
Cherry-picked from aosp/652222

Change-Id: Idc83669feaf9fd17bed26f89dfce33e3f2f5424f

Test: manually tested to prevent sepolicy violation
Change-Id: I9ebcc86464a9fc61a49d5c9be40f19f3523b6785

Test: Builds

Bug: 64121714
Bug: 31973802
Change-Id: Id37be8726a8bb297e35bca494964fdbcc48c6a73

This reverts commit 6f2040f8.

Reason for revert: not needed anymore after ag/3773705
This was meant to allow system_server toggling the property on/off.
Later we realized that we needed a separate property for that 
(see discussion in b/76077784) and system server happens to
have already permissions to write to sys.* properties even without
this CL.
Reverting because at this point this creates just unnecessary clutter.

Change-Id: Ia73d000aad3c4288a5652047dfe10896e231b0b1
Test: perfetto_integrationtests
Bug: 76077784

The permission to allow system_server to access sys/fs/bpf/ directory
is missing. Add it back so it can get the bpf maps from the bpf_fs.

Test: device boot and no more denial information of system_server try to
searcg in fs_bpf
      atest android.net.cts.TrafficStatsTest
Bug: 75285088

Change-Id: I1040cde6c038eccc4e91c69a10b20aa7a18b19f6
(cherry picked from aosp commit f83bbd17)

The permission to allow system_server to access sys/fs/bpf/ directory
is missing. Add it back so it can get the bpf maps from the bpf_fs.

Test: device boot and no more denial information of system_server try to
searcg in fs_bpf
      atest android.net.cts.TrafficStatsTest
Bug: 75285088

Change-Id: I1040cde6c038eccc4e91c69a10b20aa7a18b19f6

So that perfprofd can send larger packets to dropbox.

Follow-up of commit 3fa95acb.

(cherry picked from commit c9df8437)

Bug: 73175642
Test: m
Test: manual
Merged-In: I88d1f83962243589909ff1ce3d02195e7c494256
Change-Id: I88d1f83962243589909ff1ce3d02195e7c494256

Based on the following audit message:

type=1400 audit(1521738979.005:385): avc: denied { write } for pid=1269
comm="Binder:1269_B" name="timerslack_ns" dev="proc" ino=254190
scontext=u:r:system_server:s0 tcontext=u:r:hal_audio_default:s0
tclass=file permissive=1

Bug: 74110604
Test: adb shell dmesg | grep hal_audio_default
Change-Id: I4c2e787588eb9d223d5e50e1bc8f67876de97c2e

Based on the following audit message:

type=1400 audit(1521738979.005:385): avc: denied { write } for pid=1269
comm="Binder:1269_B" name="timerslack_ns" dev="proc" ino=254190
scontext=u:r:system_server:s0 tcontext=u:r:hal_audio_default:s0
tclass=file permissive=1

Bug: 74110604
Test: adb shell dmesg | grep hal_audio_default
Change-Id: I4c2e787588eb9d223d5e50e1bc8f67876de97c2e

So that perfprofd can send larger packets to dropbox.

Follow-up of commit 3fa95acb.

Bug: 73175642
Test: m
Test: manual
Change-Id: I88d1f83962243589909ff1ce3d02195e7c494256

To enable/disable the traced and traced_probes deamons remotely we would
like system server to be able to set persist.traced.enable.
See also ag/3736001.

Denial:
selinux: avc: denied { set } for
property=persist.traced.enable
pid=1606 uid=1000 gid=1000
scontext=u:r:system_server:s0
tcontext=u:object_r:default_prop:s0 tclass=property_service
permissive=0\x0a

Run:
$ adb shell 'ps -A | grep traced'
Should see traced.
$ adb shell 'settings put global sys_traced 0'
$ adb shell 'ps -A | grep traced'
Should no longer see traced.

Test: See above.
Change-Id: I245b7df3853cabeb0e75db41fb4facaa178ab8f1

With the new patches backported to 4.9 kernels, the bpf file system now
take the same file open flag as bpf_obj_get. So system server now need
read permission only for both bpf map and fs_bpf since we do not need
system server to edit the map. Also, the netd will always pass stdin
stdout fd to the process forked by it and do allow it will cause the
fork and execev fail. We just allow it pass the fd to bpfloader for now
until we have a better option.

Test: bpfloader start successful on devices with 4.9 kernel.
      run cts -m CtsNetTestCases -t android.net.cts.TrafficStatsTest
Bug: 74096311
Bug: 30950746

Change-Id: I747a51cb05ae495c155e7625a3021fc77f921e0d

With the new patches backported to 4.9 kernels, the bpf file system now
take the same file open flag as bpf_obj_get. So system server now need
read permission only for both bpf map and fs_bpf since we do not need
system server to edit the map. Also, the netd will always pass stdin
stdout fd to the process forked by it and do allow it will cause the
fork and execev fail. We just allow it pass the fd to bpfloader for now
until we have a better option.

Test: bpfloader start successful on devices with 4.9 kernel.
      run cts -m CtsNetTestCases -t android.net.cts.TrafficStatsTest
Bug: 74096311
Bug: 30950746

Change-Id: I747a51cb05ae495c155e7625a3021fc77f921e0d

UsbDeviceManager in system_server now
helps set up the endpoint files.

Bug: 72877174
Test: No selinux denials
Change-Id: I96b11ee68799ac29b756d2034e7f5e4660dbed98

avc: denied { getattr } for path="/vendor/framework"
scontext=u:r:system_server:s0 tcontext=u:object_r:vendor_framework_file:s0
tclass=dir

Bug: 68826235
Test: boot Taimen, verify denials no longer occur.
Change-Id: Id4b311fd423342c8d6399c3b724417aff9d1cd88

The webview_zygote is now launched as a child-zygote process from the
main zygote process.

Bug: 63749735
Test: m
Test: Launch "Third-party licenses" activity from Settings, and it
      renders correctly via the WebView.
Merged-In: I9c948b58a969d35d5a5add4b6ab62b8f990645d1
Change-Id: I153476642cf14883b0dfea0d9f5b3b5e30ac1c08

The webview_zygote is now launched as a child-zygote process from the
main zygote process.

Bug: 63749735
Test: m
Test: Launch "Third-party licenses" activity from Settings, and it
      renders correctly via the WebView.
Change-Id: I9c948b58a969d35d5a5add4b6ab62b8f990645d1

In this architecture, the system_server instructs the zygote to fork a
child-zygote to be the webview_zygote. The system_server tells this new
zygote to listen for fork requests on a random abstract unix socket of
its choosing.

A follow-up CL will remove the rules for starting webview_zygote via
init.

Bug: 63749735
Test: m
Test: Launch "Third-party licenses" activity from Settings, and it
      renders correctly via the WebView.
Merged-In: I864743943c11c18de386010ecd4b616721cb9954
Change-Id: I1c352e47b66eca3a3fa641daa6ecc3e7a889b54e

In this architecture, the system_server instructs the zygote to fork a
child-zygote to be the webview_zygote. The system_server tells this new
zygote to listen for fork requests on a random abstract unix socket of
its choosing.

A follow-up CL will remove the rules for starting webview_zygote via
init.

Bug: 63749735
Test: m
Test: Launch "Third-party licenses" activity from Settings, and it
      renders correctly via the WebView.
Change-Id: I864743943c11c18de386010ecd4b616721cb9954

A change in the "open" syscall between kernel 4.4 and 4.9 means that
the "create" action is now checked and makes system_server trigger
an SELinux denial when PackageSettings is removing a user ID from
Settings.java/writeKernelRemoveUserLPr() in PackageManager.

Bug: 70150770
Test: Manual
- Add a new user on the device, no need to perform setup.
- Wait 30s
- Remove the added user
- While running, check the result of:
    adb logcat -v time -b events | grep audit | grep system_server
Change-Id: I1f490ea95d5bcb2adc76cba041bffbea131b447a

Bug: 71527305
Test: compile and boot
Change-Id: I91097bd62d99b8dd9eb6f53060badbaf0f4b8b4a
(cherry picked from commit 1aedf4b5)

Instead of having statsd linking the perfetto client library
and talk directly to its socket, we let just statsd exec()
the /system/bin/perfetto cmdline client.

There are two reasons for this:
1) Simplify the interaction between statsd and perfetto, reduce
  dependencies, binary size bloat and isolate faults.
2) The cmdline client also takes care of handing the trace to
  Dropbox. This allows to expose the binder interaction surface
  to the short-lived cmdline client and avoid to grant binder
  access to the perfetto traced daemon.

This cmdline client will be used by:
 - statsd
 - the shell user (for our UI and Studio)

Bug: 70942310
Change-Id: I8cdde181481ad0a1a5cae5937ac446cedac54a1f

Allow dumpstate & system server watchdog to dump statsd stacks.

Bug: 72461610
Test: m
Change-Id: I4c3472881da253f85d54b5e5b767b06e2618af9c

Do not let apps read /proc/uid_cpupower/time_in_state,
/proc/uid_cpupower/concurrent_active_time,
/proc/uid_cpupower/concurrent_policy_time.

b/71718257

Test: Check that they can't be read from the shell
    without root permissions and system_server was able
    to read them

Change-Id: I812694adfbb4630f7b56aa7096dc2e6dfb148b15

This is an experimental feature only on userdebug and eng build.

Test: play MP4 file. install & uninstall media update apk.
Bug: 67908547
Change-Id: I513cdbfda962f00079e886b7a42f9928e81f6474

Bug: 64222712
Test: manual
Change-Id: Ica77ae3c9e535eddac9fccf11710b0bcb3254ab3

Bug: 63669128
Test: Checked for avc denail messages.
Change-Id: I057b3cf9ccc945cb943b9cf60fc9cd6c023eddda
Merged-In: I057b3cf9ccc945cb943b9cf60fc9cd6c023eddda

Bug: 63669128
Test: Checked for avc denail messages.
Change-Id: I057b3cf9ccc945cb943b9cf60fc9cd6c023eddda

CpuFrequency.java seems to be the only thing that depends on
/sys/devices/system/cpu in system_server. And according to
b/68988722#comment15, that dependency is not exercised.

Bug: 68988722
Test: walleye boots without denials to sysfs_devices_system_cpu
Change-Id: If777b716bf74188581327b7f5aa709f5d88aad2d

Duplicate property names are supported now for prefix and exact
matching.

Bug: 38146102
Test: tested on walleye with PRODUCT_COMPATIBLE_PROPERTY=true
Change-Id: Ifd9d32eaece7370d69f121e88d5541f7a2e34458

Change sepolicy permissions to now classify hostapd as a HAL exposing
HIDL interface.

Sepolicy denial for accessing /data/vendor/misc/wifi/hostapd:
12-27 23:40:55.913  4952  4952 W hostapd : type=1400 audit(0.0:19): avc:
denied { write } for name="hostapd" dev="sda13" ino=4587601
scontext=u:r:hal_wifi_hostapd_default:s0
tcontext=u:object_r:system_data_file:s0 tclass=dir permissive=0

01-02 19:07:16.938  5791  5791 W hostapd : type=1400 audit(0.0:31): avc:
denied { search } for name="net" dev="sysfs" ino=30521
scontext=u:r:hal_wifi_hostapd_default:s0
tcontext=u:object_r:sysfs_net:s0 tclass=dir permissive=0

Bug: 36646171
Test: Device boots up and able to turn on SoftAp.
Change-Id: Ibacfcc938deab40096b54b8d0e608d53ca91b947

/proc/net/xt_qtaguid is used by apps to track their network data
use. Limit access to just zygote spawned processes - apps and
system_server, omitting access to isolated_app which is not allowed
to create network sockets.
As Android moves to eBPF for app's network data stats, access to
/proc/net/xt_qtaguid will be removed entirely. Segmenting access off
is the first step.
Bug: 68774956

This change also helps further segment and whitelist access to
files in /proc/net and is a step in the lockdown of /proc/net.
Bug: 9496886

Test: boot Taimen. Walk through setup-wizard. Make phone call and
    video call. Browse web. Watch youtube. Navigate in maps.
Test: cts-tradefed run cts -m CtsAppSecurityHostTestCases -t \
    android.appsecurity.cts.AppSecurityTests
Test: cts-tradefed run cts -m CtsNativeNetTestCases
Test: cts-tradefed run cts -m CtsIncidentHostTestCases -t \
    com.android.server.cts.NetstatsIncidentTest
Test: cts-tradefed run cts -m CtsOsTestCases -t \
    android.os.cts.StrictModeTest
Test: cts-tradefed run cts -m CtsNetTestCases -t \
    android.net.cts.TrafficStatsTest
Test: cts-tradefed run cts -m CtsUsageStatsTestCases -t \
    android.app.usage.cts.NetworkUsageStatsTest
Test: vts-tradefed run vts -m VtsQtaguidTest
Change-Id: Idddd318c56b84564142d37b11dcc225a2f2800ea

Bug: 71527305
Test: compile and boot
Change-Id: I91097bd62d99b8dd9eb6f53060badbaf0f4b8b4a

This CL lists all the exported platform properties in
private/exported_property_contexts.

Additionally accessing core_property_type from vendor components is
restricted.
Instead public_readable_property_type is used to allow vendor components
to read exported platform properties, and accessibility from
vendor_init is also specified explicitly.

Note that whitelisting would be applied only if
PRODUCT_COMPATIBLE_PROPERTY is set on.

Bug: 38146102
Test: tested on walleye with PRODUCT_COMPATIBLE_PROPERTY=true
Change-Id: I304ba428cc4ca82668fec2ddeb17c971e7ec065e

The system server is responsible for providing the network traffic
stats to Apps and services. Allow it to directly reading the eBPF maps
that stored these information can make the process of getting traffic
stats simplier.

Test: No selinux rule violation of system server reading netd bpf object
Bug: 30950746
Change-Id: I6d9438d1ed7c9bab45a708f5d2a85eb22f5e8170

Bug: 63908748
Test: Able to boot
Change-Id: I14d8856d7aac7be9d1f26ecf5bfff69ea5ee9607