Add code to BpfCoordinator to dump upstream IPv4 and IPv6 rules.
For IPv4, currently only the upstream map is printed, because the
downstream map is expected to be symmetrical.

Example output:

=============
    21(21) -> 12(rmnet_data2) 86dd 00:00:00:00:00:00 00:00:00:00:00:00
    [wlan1]: iif(iface) oif(iface) v6addr srcmac dstmac
      12(rmnet_data2) 21(wlan1) /2001:240:2425:b5dc:21a9:995d:bc57:bc37 b2:b5:e0:24:21:c2 ca:06:8d:54:99:ad
    [IPv4]: iif(iface) oif(iface) src nat dst
      21(21) 12(rmnet_data2) 192.168.16.247:41544 -> 100.101.80.108:41544 -> 216.239.36.135:443
      21(21) 12(rmnet_data2) 192.168.16.247:42028 -> 100.101.80.108:42028 -> 8.8.4.4:853
      21(21) 12(rmnet_data2) 192.168.16.247:42032 -> 100.101.80.108:42032 -> 8.8.4.4:853
      21(21) 12(rmnet_data2) 192.168.16.247:42042 -> 100.101.80.108:42042 -> 8.8.4.4:853
      21(21) 12(rmnet_data2) 192.168.16.247:41816 -> 100.101.80.108:41816 -> 8.8.8.8:853
      21(21) 12(rmnet_data2) 192.168.16.247:42040 -> 100.101.80.108:42040 -> 8.8.4.4:853

=============

Also make it possible to do "dumpsys tethering bpf" and get only
the BPF dump.

Test: manual
Change-Id: I2aaa2fdda7d724994090c26feff585f24cd3283b

* changes:
  Remove IpServer.Dependencies#getIfIndex.
  Address comments on aosp/1559686.

Test: N/A
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ic217e08484c39077bcc408195daa3311ed93ad28

This code is unused.

Test: atest TetheringTests
Change-Id: Iaac422d72e8538b67798cb3ae3737deb7b426401

Also remove some unnecessary line wrapping.

Test: atest TetheringTests
Change-Id: Ia7638b3198d7811cdbb34e959c50608cf1a656bf

Test: new unit test
Change-Id: Ibec09f328e24111aee4760af2f75ea5a80ba84c3

Test: test-only change
Change-Id: I9a47234979cbb161dfcd0c97c54c0476aa753c5e

- Add methods to start and stop IPv6 forwarding upstream
- Populate the upstream IPv6 map when the first rule for any
  upstream/downstream pair is created.
- Clear the upstream IPv6 map when the last rule for any
  upstream/downstream pair is deleted.

Test: Added coverage to IpServerTest and BpfCoordinatorTest
Change-Id: Ib041081e95f5f449489ab63138de034222ffac8f

The two value types are identical so there is no need to have
separate classes for them.

Test: atest TetheringTests
Change-Id: Ia622b082d0a44373d21f51222f5e675e5bde08e0

* changes:
  merge Tether{Down,Up}stream4{Key,Value} - part 3 - fixups
  merge Tether{Down,Up}stream4{Key,Value} - part 2 - java
  merge Tether{Down,Up}stream4{Key,Value} - part 1 - C portion

These are read-only intents and should not be mutated by any
app receiving them.

Bug: 178324405
Bug: 178249531
Test: atest TetheringTests TetheringCoverageTests GtsTetheringTestCases
Change-Id: I5395e7c19e6453640ad790f2b9a9ba22bbcefa88

Bug: 178324405
Test: atest TetheringTests
Change-Id: I2069ea79f982e6bb197388edd7820a05d1e651f1

Test: atest, TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ia7840698e80ded33d8e0b59efe1ca7267254b892

Generated via:
  git grep 'Tether(Down|Up)stream4(Key|Value)' | cut -d: -f1 | sort -u | while read i; do
    sed -r -i 's@TetherUpstream4Value@Tether4Value@g' "$i"
    sed -r -i 's@TetherDownstream4Value@Tether4Value@g' "$i"
    sed -r -i 's@TetherDownstream4Key@Tether4Key@g' "$i"
    sed -r -i 's@TetherUpstream4Key@Tether4Key@g' "$i"
  done

  cd Tethering/src/com/android/networkstack/tethering
  git mv TetherUpstream4Key.java Tether4Key.java
  git mv TetherUpstream4Value.java Tether4Value.java

  git diff TetherDownstream4Key.java Tether4Key.java
  git diff TetherDownstream4Value.java Tether4Value.java
  git rm TetherDownstream4Key.java
  git rm TetherDownstream4Value.java

Fixup resulting 'import' duplication
  mcedit Tethering/apishim/31/com/android/networkstack/tethering/apishim/api31/BpfCoordinatorShimImpl.java
  mcedit Tethering/apishim/30/com/android/networkstack/tethering/apishim/api30/BpfCoordinatorShimImpl.java
  mcedit Tethering/apishim/common/com/android/networkstack/tethering/apishim/common/BpfCoordinatorShim.java
  mcedit Tethering/tests/unit/src/android/net/ip/IpServerTest.java

Test: N/A, requires follow up commit
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I1dfc3108ca4bbd0cefc3420bc7e421594b62619c

The keys are identical, and the values nearly so, this will make everyone's life easier.

Test: git grep 'Tether(Down|Up)stream4(Key|Value)' finds nothing
  (note this requires follow up commits)
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ifbff2c617ac5834ea80f827eaf89ca81e862baec

* changes:
  [NFCT.TETHER.10] Add/delete IPv4 offload BPF rules to/from BPF map
  [NFCT.TETHER.9] Build IPv4 offload BPF rules for raw ip

Test: atest, TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I0ad143be954d55d0ed39853031c7bd364378e1ec

Access the IPv4 downstream and upstream BPF map with the built rules.

Test: atest TetheringCoverageTests
Change-Id: I8cd6e49b377c72250988019eea57f93cccd78309

Test: atest, TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Icabd1db48a1189425a941384d534c0f18bf20827

Test: atest, TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I649dc490b1883a1e97f748370a77c956f1315e2e

* changes:
  [NFCT.TETHER.8] Prepare the upstream information for IPv4 offload rule
  [NFCT.TETHER.7] Prepare the downstream information for IPv4 offload rule

We want connection establishment/shutdown to flow through
the kernel code path so connection tracking state is at least
somewhat correct.

Test: atest, TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Iee97baa65750188f3436937b16c9b320f0495a5a

Bug: 155176305
Change-Id: I62958d041a8f544dbd98d5434e97ce89f843c5cb

Build the upstream and upstream rules when the conntrack event is
received.

Test: atest TetheringCoverageTests
Change-Id: Ibb52c7b75812bd586091d809e260bc9206c06262

Add upstream interface index and its IPv4 address mapping

Required for building IPv4 forwarding rule when a conntrack event is
received.

Test: atest TetheringCoverageTests
Change-Id: I73f304777704f09481b80d18751e0bab5bab2edc

Add and remove downstream client information to BpfCoordinator

Required for building IPv4 forwarding rule when a conntrack event is
received. The IpServer provides the following elements of a rule which
is not included in conntrack event:
- Downstream interface index
- Downstream Mac address
- Client IP address to Client Mac address

Test: atest TetheringCoverageTests
Change-Id: I84db13acc047ace5730d17f0d3dd99544f516084

Test: atest, TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Idaaa1ede7c239655f5ec489532533c363d297864

A preparation for starting monitoring conntrack event which is required
by IPv4 tethering offload.

Test: atest TetheringCoverageTests
Change-Id: Ied46aeca193554f52a90889dfdf92827e94845d6

Test: atest, TreeHugger, the programs load
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Idcacf0502719336c1b6a959fe6b782f2bce9d6b5

Additionally better document tether stats/limit keys/value.

Test: atest, TreeHugger, the programs load
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I1e1832fc4f5a6704e00ea99ca377988c52a82eb1

* changes:
  switch bpf programs to group network_stack
  Add tethering programs for upstream.

Test: atest, TreeHugger, the programs load
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I3ab4383978acb2681a0fd5aee2700d12c62c2769

Test: atest, TreeHugger, the programs load
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I26bc60c1066ed7317bda48ec3fa701c36e0b46dd

Test: builds, atest, TreeHugger
  git grep 'makeIngressKey|makeIngressValue|BpfIngressMap|TETHER_INGRESS_FS_PATH'
  no longer finds anything
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I27200d33cbc4ea2094b18e05bf93ab54c564da0b

Generated via:
  #!/bin/bash

  do_replace() {
    pushd "$1" >/dev/null
    shift
    git grep "$1" | cut -d: -f1 | sort -u | while read f; do
      sed -i -r "s@$1@$2@g" "${f}"
      git add "${f}"
    done
    popd >/dev/null
  }

  replace() {
    do_replace packages/modules/Connectivity/Tethering "$@"
    do_replace system/netd "$@"
  }

  do_reset() {
    pushd "$1" >/dev/null
    git rhh
    popd >/dev/null
  }

  main() {
    do_reset packages/modules/Connectivity/Tethering
    do_reset system/netd

    replace TetherIngressKey TetherDownstream6Key
    replace TetherIngressValue TetherDownstream6Value

    pushd packages/modules/Connectivity/Tethering/src/com/android/networkstack/tethering >/dev/null
    git mv TetherIngressKey.java TetherDownstream6Key.java
    git mv TetherIngressValue.java TetherDownstream6Value.java
    popd >/dev/null

    replace TETHER_INGRESS_PROG TETHER_DOWNSTREAM6_TC_PROG
    replace ingress_tether tether_downstream6
    replace ingress/tether_ tether_downstream6_
    replace TETHER_INGRESS_MAP TETHER_DOWNSTREAM6_MAP
    replace tether_ingress_map tether_downstream6_map

    replace getTetherIngressMapFd getTetherDownstream6MapFd
    replace getTetherIngressProgFd getTetherDownstream6TcProgFd

    replace mBpfIngressMap mBpfDownstream6Map
    replace bpfIngressMap bpfDownstream6Map
    replace printIngressMap printDownstream6Map
    replace 'BPF ingress map' 'BPF downstream ipv6 map'
  }

  main "$@"; exit

Followed by:
  cd system/netd
  # change regexp in tests/binder_test.cpp:3374
  git add tests/binder_test.cpp

(and whitespace adjustments to prevent lines from going over 100 characters)

Afterwards we have:
  $ adbz shell ls /sys/fs/bpf/tethering
  map_offload_tether_downstream6_map
  map_offload_tether_limit_map
  map_offload_tether_stats_map
  map_test_tether_downstream6_map
  prog_offload_schedcls_tether_downstream6_ether
  prog_offload_schedcls_tether_downstream6_rawip
  prog_test_xdp_drop_ipv4_udp_ether

Test: atest, TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ib04dc0c6e3d034461f3f84e09f6fa93a862e1bb2

Test: builds, boots, program present
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Id5be48ec172366296929875856a3d17ecc87e84b