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-rw-r--r--modules/view/README.rst89
-rw-r--r--modules/view/addr.test.integr/deckard.yaml12
-rw-r--r--modules/view/addr.test.integr/kresd_config.j253
-rw-r--r--modules/view/addr.test.integr/module_view_addr.rpl78
-rw-r--r--modules/view/tsig.test.integr/deckard.yaml12
-rw-r--r--modules/view/tsig.test.integr/kresd_config.j255
-rw-r--r--modules/view/tsig.test.integr/module_view_tsig.rpl113
-rw-r--r--modules/view/view.lua118
-rw-r--r--modules/view/view.mk2
9 files changed, 532 insertions, 0 deletions
diff --git a/modules/view/README.rst b/modules/view/README.rst
new file mode 100644
index 0000000..3fa043a
--- /dev/null
+++ b/modules/view/README.rst
@@ -0,0 +1,89 @@
+.. _mod-view:
+
+Views and ACLs
+--------------
+
+The :ref:`policy <mod-policy>` module implements policies for global query matching, e.g. solves "how to react to certain query".
+This module combines it with query source matching, e.g. "who asked the query". This allows you to create personalized blacklists, filters and ACLs.
+
+There are two identification mechanisms:
+
+* ``addr``
+ - identifies the client based on his subnet
+* ``tsig``
+ - identifies the client based on a TSIG key name (only for testing purposes, TSIG signature is not verified!)
+
+View module allows you to combine query source information with :ref:`policy <mod-policy>` rules.
+
+.. code-block:: lua
+
+ view:addr('10.0.0.1', policy.suffix(policy.TC, policy.todnames({'example.com'})))
+
+This example will force given client to TCP for names in ``example.com`` subtree.
+You can combine view selectors with RPZ_ to create personalized filters for example.
+
+.. warning::
+
+ Beware that cache is shared by *all* requests. For example, it is safe
+ to refuse answer based on who asks the resolver, but trying to serve
+ different data to different clients will result in unexpected behavior.
+ Setups like **split-horizon** which depend on isolated DNS caches
+ are explicitly not supported.
+
+
+Example configuration
+^^^^^^^^^^^^^^^^^^^^^
+
+.. code-block:: lua
+
+ -- Load modules
+ modules = { 'view' }
+ -- Whitelist queries identified by TSIG key
+ view:tsig('\5mykey', policy.all(policy.PASS))
+ -- Block local clients (ACL like)
+ view:addr('127.0.0.1', policy.all(policy.DENY))
+ -- Drop queries with suffix match for remote client
+ view:addr('10.0.0.0/8', policy.suffix(policy.DROP, policy.todnames({'xxx'})))
+ -- RPZ for subset of clients
+ view:addr('192.168.1.0/24', policy.rpz(policy.PASS, 'whitelist.rpz'))
+ -- Do not try this - it will pollute cache and surprise you!
+ -- view:addr('10.0.0.0/8', policy.all(policy.FORWARD('2001:DB8::1')))
+ -- Drop everything that hasn't matched
+ view:addr('0.0.0.0/0', policy.all(policy.DROP))
+
+
+Rule order
+^^^^^^^^^^
+
+The current implementation is best understood as three separate rule chains:
+vanilla ``policy.add``, ``view:tsig`` and ``view:addr``.
+For each request the rules in these chains get tried one by one until a :ref:`non-chain policy action <mod-policy-actions>` gets executed.
+
+By default :ref:`policy module <mod-policy>` acts before ``view`` module due to ``policy`` being loaded by default. If you want to intermingle universal rules with ``view:addr``, you may simply wrap the universal policy rules in view closure like this:
+
+.. code-block:: lua
+
+ view:addr('0.0.0.0/0', policy.<rule>) -- and
+ view:addr('::0/0', policy.<rule>)
+
+
+Properties
+^^^^^^^^^^
+
+.. function:: view:addr(subnet, rule)
+
+ :param subnet: client subnet, i.e. ``10.0.0.1``
+ :param rule: added rule, i.e. ``policy.pattern(policy.DENY, '[0-9]+\2cz')``
+
+ Apply rule to clients in given subnet.
+
+.. function:: view:tsig(key, rule)
+
+ :param key: client TSIG key domain name, i.e. ``\5mykey``
+ :param rule: added rule, i.e. ``policy.pattern(policy.DENY, '[0-9]+\2cz')``
+
+ Apply rule to clients with given TSIG key.
+
+ .. warning:: This just selects rule based on the key name, it doesn't verify the key or signature yet.
+
+.. _RPZ: https://dnsrpz.info/
diff --git a/modules/view/addr.test.integr/deckard.yaml b/modules/view/addr.test.integr/deckard.yaml
new file mode 100644
index 0000000..ac2792d
--- /dev/null
+++ b/modules/view/addr.test.integr/deckard.yaml
@@ -0,0 +1,12 @@
+programs:
+- name: kresd
+ binary: kresd
+ additional:
+ - -f
+ - "1"
+ templates:
+ - modules/view/addr.test.integr/kresd_config.j2
+ - tests/hints_zone.j2
+ configs:
+ - config
+ - hints
diff --git a/modules/view/addr.test.integr/kresd_config.j2 b/modules/view/addr.test.integr/kresd_config.j2
new file mode 100644
index 0000000..f56430a
--- /dev/null
+++ b/modules/view/addr.test.integr/kresd_config.j2
@@ -0,0 +1,53 @@
+{% raw %}
+modules.load('view < policy')
+
+view:addr('127.0.0.0/24', policy.suffix(policy.DENY_MSG("addr 127.0.0.0/24 matched com"),{"\3com\0"}))
+view:addr('127.0.0.0/24', policy.suffix(policy.DENY_MSG("addr 127.0.0.0/24 matched net"),{"\3net\0"}))
+policy.add(policy.all(policy.FORWARD('1.2.3.4')))
+
+-- Disable RFC8145 signaling, scenario doesn't provide expected answers
+if ta_signal_query then
+ modules.unload('ta_signal_query')
+end
+
+-- Disable RFC8109 priming, scenario doesn't provide expected answers
+if priming then
+ modules.unload('priming')
+end
+
+-- Disable this module because it make one priming query
+if detect_time_skew then
+ modules.unload('detect_time_skew')
+end
+
+_hint_root_file('hints')
+cache.size = 2*MB
+verbose(true)
+{% endraw %}
+
+net = { '{{SELF_ADDR}}' }
+
+
+{% if QMIN == "false" %}
+option('NO_MINIMIZE', true)
+{% else %}
+option('NO_MINIMIZE', false)
+{% endif %}
+
+
+-- Self-checks on globals
+assert(help() ~= nil)
+assert(worker.id ~= nil)
+-- Self-checks on facilities
+assert(cache.count() == 0)
+assert(cache.stats() ~= nil)
+assert(cache.backends() ~= nil)
+assert(worker.stats() ~= nil)
+assert(net.interfaces() ~= nil)
+-- Self-checks on loaded stuff
+assert(net.list()['{{SELF_ADDR}}'])
+assert(#modules.list() > 0)
+-- Self-check timers
+ev = event.recurrent(1 * sec, function (ev) return 1 end)
+event.cancel(ev)
+ev = event.after(0, function (ev) return 1 end)
diff --git a/modules/view/addr.test.integr/module_view_addr.rpl b/modules/view/addr.test.integr/module_view_addr.rpl
new file mode 100644
index 0000000..9e65d28
--- /dev/null
+++ b/modules/view/addr.test.integr/module_view_addr.rpl
@@ -0,0 +1,78 @@
+; config options
+ stub-addr: 1.2.3.4
+ query-minimization: off
+CONFIG_END
+
+SCENARIO_BEGIN view:addr test
+
+RANGE_BEGIN 0 110
+ ADDRESS 1.2.3.4
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR RD RA NOERROR
+SECTION QUESTION
+example.cz. IN A
+SECTION ANSWER
+example.cz. IN A 5.6.7.8
+ENTRY_END
+
+RANGE_END
+
+; policy module loaded before view module must take precedence before view
+STEP 10 QUERY
+ENTRY_BEGIN
+REPLY RD
+SECTION QUESTION
+example.cz. IN A
+ENTRY_END
+
+STEP 20 CHECK_ANSWER
+ENTRY_BEGIN
+MATCH flags rcode question answer
+REPLY QR RD RA NOERROR
+SECTION QUESTION
+example.cz. IN A
+SECTION ANSWER
+example.cz. IN A 5.6.7.8
+ENTRY_END
+
+; blocked by view:addr + inner policy.suffix com
+; NXDOMAIN expected
+STEP 30 QUERY
+ENTRY_BEGIN
+REPLY RD
+SECTION QUESTION
+example.com. IN A
+ENTRY_END
+
+STEP 31 CHECK_ANSWER
+ENTRY_BEGIN
+MATCH opcode question rcode additional
+REPLY QR RD RA AA NXDOMAIN
+SECTION QUESTION
+example.com. IN A
+SECTION ADDITIONAL
+explanation.invalid. 10800 IN TXT "addr 127.0.0.0/24 matched com"
+ENTRY_END
+
+; blocked by view:addr + inner policy.suffix net
+; second view rule gets executed if policy in preceding view rule did not match
+STEP 32 QUERY
+ENTRY_BEGIN
+REPLY RD
+SECTION QUESTION
+example.net. IN A
+ENTRY_END
+
+STEP 33 CHECK_ANSWER
+ENTRY_BEGIN
+MATCH opcode question rcode additional
+REPLY QR RD RA AA NXDOMAIN
+SECTION QUESTION
+example.net. IN A
+SECTION ADDITIONAL
+explanation.invalid. 10800 IN TXT "addr 127.0.0.0/24 matched net"
+ENTRY_END
+
+SCENARIO_END
diff --git a/modules/view/tsig.test.integr/deckard.yaml b/modules/view/tsig.test.integr/deckard.yaml
new file mode 100644
index 0000000..bc89906
--- /dev/null
+++ b/modules/view/tsig.test.integr/deckard.yaml
@@ -0,0 +1,12 @@
+programs:
+- name: kresd
+ binary: kresd
+ additional:
+ - -f
+ - "1"
+ templates:
+ - modules/view/tsig.test.integr/kresd_config.j2
+ - tests/hints_zone.j2
+ configs:
+ - config
+ - hints
diff --git a/modules/view/tsig.test.integr/kresd_config.j2 b/modules/view/tsig.test.integr/kresd_config.j2
new file mode 100644
index 0000000..6a0952e
--- /dev/null
+++ b/modules/view/tsig.test.integr/kresd_config.j2
@@ -0,0 +1,55 @@
+{% raw %}
+modules.load('view')
+print(table_print(modules.list()))
+
+view:tsig('\8testkey1\0', policy.suffix(policy.DENY_MSG("TSIG key testkey1 matched com"),{"\3com\0"}))
+view:tsig('\8testkey1\0', policy.suffix(policy.DENY_MSG("TSIG key testkey1 matched net"),{"\3net\0"}))
+view:tsig('\7testkey\0', policy.suffix(policy.DENY_MSG("TSIG key testkey matched example"),{"\7example\0"}))
+policy.add(policy.all(policy.FORWARD('1.2.3.4')))
+
+-- Disable RFC8145 signaling, scenario doesn't provide expected answers
+if ta_signal_query then
+ modules.unload('ta_signal_query')
+end
+
+-- Disable RFC8109 priming, scenario doesn't provide expected answers
+if priming then
+ modules.unload('priming')
+end
+
+-- Disable this module because it make one priming query
+if detect_time_skew then
+ modules.unload('detect_time_skew')
+end
+
+_hint_root_file('hints')
+cache.size = 2*MB
+verbose(true)
+{% endraw %}
+
+net = { '{{SELF_ADDR}}' }
+
+
+{% if QMIN == "false" %}
+option('NO_MINIMIZE', true)
+{% else %}
+option('NO_MINIMIZE', false)
+{% endif %}
+
+
+-- Self-checks on globals
+assert(help() ~= nil)
+assert(worker.id ~= nil)
+-- Self-checks on facilities
+assert(cache.count() == 0)
+assert(cache.stats() ~= nil)
+assert(cache.backends() ~= nil)
+assert(worker.stats() ~= nil)
+assert(net.interfaces() ~= nil)
+-- Self-checks on loaded stuff
+assert(net.list()['{{SELF_ADDR}}'])
+assert(#modules.list() > 0)
+-- Self-check timers
+ev = event.recurrent(1 * sec, function (ev) return 1 end)
+event.cancel(ev)
+ev = event.after(0, function (ev) return 1 end)
diff --git a/modules/view/tsig.test.integr/module_view_tsig.rpl b/modules/view/tsig.test.integr/module_view_tsig.rpl
new file mode 100644
index 0000000..8abceb5
--- /dev/null
+++ b/modules/view/tsig.test.integr/module_view_tsig.rpl
@@ -0,0 +1,113 @@
+; config options
+ stub-addr: 1.2.3.4
+CONFIG_END
+
+SCENARIO_BEGIN view:tsig test
+
+RANGE_BEGIN 0 110
+ ADDRESS 1.2.3.4
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR RD RA NOERROR
+SECTION QUESTION
+example.cz. IN A
+SECTION ANSWER
+example.cz. IN A 5.6.7.8
+ENTRY_END
+
+RANGE_END
+
+RANGE_BEGIN 0 110
+ ADDRESS 192.0.2.1
+ENTRY_BEGIN
+MATCH opcode qtype qname
+ADJUST copy_id
+REPLY QR RD RA NOERROR
+SECTION QUESTION
+example.net. IN A
+SECTION ANSWER
+example.net. IN A 6.6.6.6
+ENTRY_END
+RANGE_END
+
+; policy fallback (no view matched, policy is behind view module)
+STEP 10 QUERY
+ENTRY_BEGIN
+REPLY RD
+TSIG testkey +Cdjlkef9ZTSeixERZ433Q==
+SECTION QUESTION
+example.cz. IN A
+ENTRY_END
+
+STEP 20 CHECK_ANSWER
+ENTRY_BEGIN
+MATCH flags rcode question answer
+REPLY QR RD RA NOERROR
+SECTION QUESTION
+example.cz. IN A
+SECTION ANSWER
+example.cz. IN A 5.6.7.8
+ENTRY_END
+
+; blocked by view:tsig testkey1 + inner policy.suffix com
+; NXDOMAIN expected
+STEP 30 QUERY
+ENTRY_BEGIN
+REPLY RD
+TSIG testkey1 +Cdjlkef9ZTSeixERZ433Q==
+SECTION QUESTION
+example.com. IN A
+ENTRY_END
+
+STEP 31 CHECK_ANSWER
+ENTRY_BEGIN
+MATCH opcode question rcode additional
+REPLY QR RD RA AA NXDOMAIN
+SECTION QUESTION
+example.com. IN A
+SECTION ADDITIONAL
+explanation.invalid. 10800 IN TXT "TSIG key testkey1 matched com"
+ENTRY_END
+
+; blocked by view:tsig testkey1 + inner policy.suffix net
+; second view rule gets executed if policy in preceding view rule did not match
+STEP 32 QUERY
+ENTRY_BEGIN
+REPLY RD
+TSIG testkey1 +Cdjlkef9ZTSeixERZ433Q==
+SECTION QUESTION
+example.net. IN A
+ENTRY_END
+
+STEP 33 CHECK_ANSWER
+ENTRY_BEGIN
+MATCH opcode question rcode additional
+REPLY QR RD RA AA NXDOMAIN
+SECTION QUESTION
+example.net. IN A
+SECTION ADDITIONAL
+explanation.invalid. 10800 IN TXT "TSIG key testkey1 matched net"
+ENTRY_END
+
+; blocked by view:tsig testkey + inner policy.suffix example (different key)
+; third view rule gets executed if policy in preceding view rule did not match
+STEP 34 QUERY
+ENTRY_BEGIN
+REPLY RD
+TSIG testkey +Cdjlkef9ZTSeixERZ433Q==
+SECTION QUESTION
+example. IN A
+ENTRY_END
+
+STEP 35 CHECK_ANSWER
+ENTRY_BEGIN
+MATCH opcode question rcode additional
+REPLY QR RD RA AA NXDOMAIN
+SECTION QUESTION
+example. IN A
+SECTION ADDITIONAL
+explanation.invalid. 10800 IN TXT "TSIG key testkey matched example"
+ENTRY_END
+
+SCENARIO_END
diff --git a/modules/view/view.lua b/modules/view/view.lua
new file mode 100644
index 0000000..41157eb
--- /dev/null
+++ b/modules/view/view.lua
@@ -0,0 +1,118 @@
+local kres = require('kres')
+local ffi = require('ffi')
+local C = ffi.C
+
+-- Module declaration
+local view = {
+ key = {}, -- map from :owner() to list of policy rules
+ src = {},
+ dst = {},
+}
+
+-- @function View based on TSIG key name.
+function view.tsig(_, tsig, rule)
+ if view.key[tsig] == nil then
+ view.key[tsig] = { rule }
+ else
+ table.insert(view.key[tsig], rule)
+ end
+end
+
+-- @function View based on source IP subnet.
+function view.addr(_, subnet, rules, dst)
+ local subnet_cd = ffi.new('char[16]')
+ local family = C.kr_straddr_family(subnet)
+ local bitlen = C.kr_straddr_subnet(subnet_cd, subnet)
+ local t = {family, subnet_cd, bitlen, rules}
+ table.insert(dst and view.dst or view.src, t)
+ return t
+end
+
+-- @function Match IP against given subnet
+local function match_subnet(family, subnet, bitlen, addr)
+ return (family == addr:family()) and (C.kr_bitcmp(subnet, addr:ip(), bitlen) == 0)
+end
+
+-- @function Execute a policy callback (may be nil);
+-- return boolean: whether to continue trying further rules.
+local function execute(state, req, match_cb)
+ if match_cb == nil then return false end
+ local action = match_cb(req, req:current())
+ if action == nil then return false end
+ local next_state = action(state, req)
+ if next_state then -- Not a chain rule,
+ req.state = next_state
+ return true
+ else
+ return false
+ end
+end
+
+-- @function Try all the rules in order, until a non-chain rule gets executed.
+local function evaluate(state, req)
+ -- Try :tsig rules first.
+ local client_key = req.qsource.packet.tsig_rr
+ local match_cbs = (client_key ~= nil) and view.key[client_key:owner()] or {}
+ for _, match_cb in ipairs(match_cbs) do
+ if execute(state, req, match_cb) then return end
+ end
+ -- Then try :addr by the source.
+ if req.qsource.addr ~= nil then
+ for i = 1, #view.src do
+ local pair = view.src[i]
+ if match_subnet(pair[1], pair[2], pair[3], req.qsource.addr) then
+ local match_cb = pair[4]
+ if execute(state, req, match_cb) then return end
+ end
+ end
+ -- Finally try :addr by the destination.
+ elseif req.qsource.dst_addr ~= nil then
+ for i = 1, #view.dst do
+ local pair = view.dst[i]
+ if match_subnet(pair[1], pair[2], pair[3], req.qsource.dst_addr) then
+ local match_cb = pair[4]
+ if execute(state, req, match_cb) then return end
+ end
+ end
+ end
+end
+
+-- @function Return policy based on source address
+function view.rule_src(action, subnet)
+ local subnet_cd = ffi.new('char[16]')
+ local family = C.kr_straddr_family(subnet)
+ local bitlen = C.kr_straddr_subnet(subnet_cd, subnet)
+ return function(req, _)
+ local addr = req.qsource.addr
+ if addr ~= nil and match_subnet(family, subnet_cd, bitlen, addr) then
+ return action
+ end
+ end
+end
+
+-- @function Return policy based on destination address
+function view.rule_dst(action, subnet)
+ local subnet_cd = ffi.new('char[16]')
+ local family = C.kr_straddr_family(subnet)
+ local bitlen = C.kr_straddr_subnet(subnet_cd, subnet)
+ return function(req, _)
+ local addr = req.qsource.dst_addr
+ if addr ~= nil and match_subnet(family, subnet_cd, bitlen, addr) then
+ return action
+ end
+ end
+end
+
+-- @function Module layers
+view.layer = {
+ begin = function(state, req)
+ -- Don't act on "resolved" cases.
+ if bit.band(state, bit.bor(kres.FAIL, kres.DONE)) ~= 0 then return state end
+
+ req = kres.request_t(req)
+ evaluate(state, req)
+ return req.state
+ end
+}
+
+return view
diff --git a/modules/view/view.mk b/modules/view/view.mk
new file mode 100644
index 0000000..47b752d
--- /dev/null
+++ b/modules/view/view.mk
@@ -0,0 +1,2 @@
+view_SOURCES := view.lua
+$(call make_lua_module,view)
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-21 21:17:32 +0000