fwtool: generate rules in primary input/output chain
[hcoop/domtool2.git] / src / plugins / firewall.sml
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1(* HCoop Domtool (http://hcoop.sourceforge.net/)
2 * Copyright (c) 2006-2007, Adam Chlipala
93278775 3 * Copyright (c) 2011,2012,2013,2014,2018 Clinton Ebadi
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4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version 2
8 * of the License, or (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 *)
19
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20(* Firewall management *)
21
22(* Contains portions from Fwtool Copyright (C) 2005 Adam Chlipala, GPL v2 or later *)
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23
24structure Firewall :> FIREWALL = struct
25
1a03ee46 26datatype user = User of string
93278775 27
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28datatype fwnode = FirewallNode of string
29
30datatype fwrule = Client of int list * string list
31 | Server of int list * string list
32 | ProxiedServer of int list
33 | LocalServer of int list
34
35type firewall_rules = (user * fwnode * fwrule) list
73b95423 36
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37datatype fwip = FwIPv4
38 | FwIPv6
39
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40structure StringMap = DataStructures.StringMap
41
9a8de137 42fun parseRules () =
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43 let
44 val inf = TextIO.openIn Config.Firewall.firewallRules
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45
46 fun parsePorts ports =
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47 List.mapPartial Int.fromString (String.fields (fn ch => ch = #",") ports)
48 (* Just drop bad ports for now *)
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49
50 fun parseNodes nodes = String.fields (fn ch => ch = #",") nodes
51
1a03ee46 52 fun loop parsedRules =
ec95f39f 53 case TextIO.inputLine inf of
1a03ee46 54 NONE => parsedRules
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55 | SOME line =>
56 case String.tokens Char.isSpace line of
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57 nodes :: uname :: rest =>
58 let
59 val nodes = parseNodes nodes
60 in
61 case rest of
62 "Client" :: ports :: hosts => loop (map (fn node => (User uname, FirewallNode node, Client (parsePorts ports, hosts))) nodes) @ parsedRules
63 | "Server" :: ports :: hosts => loop (map (fn node => (User uname, FirewallNode node, Server (parsePorts ports, hosts))) nodes) @ parsedRules
64 | ["ProxiedServer", ports] => loop (map (fn node => (User uname, FirewallNode node, ProxiedServer (parsePorts ports))) nodes) @ parsedRules
65 | ["LocalServer", ports] => loop (map (fn node => (User uname, FirewallNode node, LocalServer (parsePorts ports))) nodes) @ parsedRules
66 | _ => (print "Invalid config line\n"; loop parsedRules)
67 end
1a03ee46 68 | _ => loop parsedRules
ec95f39f 69 in
1a03ee46 70 loop []
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71 end
72
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73fun formatQueryRule (Client (ports, hosts)) =
74 "Client " ^ String.concatWith "," (map Int.toString ports) ^ " " ^ String.concatWith " " hosts
75 | formatQueryRule (Server (ports, hosts)) =
76 "Server " ^ String.concatWith "," (map Int.toString ports) ^ " " ^ String.concatWith " " hosts
77 | formatQueryRule (ProxiedServer ports) =
78 "ProxiedServer " ^ String.concatWith "," (map Int.toString ports)
79 | formatQueryRule (LocalServer ports) =
80 "LocalServer " ^ String.concatWith "," (map Int.toString ports)
81
82fun query (node, uname) =
1a03ee46 83 (* completely broken *)
f9548f16 84 let
ec95f39f 85 val rules = parseRules ()
f9548f16 86 in
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87 map (fn (_, _, r) => formatQueryRule r)
88 (List.filter (fn (User u, FirewallNode n, _) => u = uname andalso n = node) rules)
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89 end
90
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91fun dnsExists dnsRR dnsRecord =
92 let
93 val dnsRR_string = case dnsRR of
94 FwIPv6 => "AAAA"
95 | FwIPv4 => "A"
96 in
97 (* timeout chosen arbitrarilty, shorter is better if it's reliable *)
98 (* dig outputs true even if the lookup fails, but no output in short mode should work *)
99 case Slave.runOutput (Config.Firewall.dig, ["+short", "+timeout=3", "-t", dnsRR_string, dnsRecord]) of
100 (_, SOME s) => (case Domain.validDomain (substring (s, 0, size s - 2)) of (* delete trailing . from cname *)
101 true => dnsExists dnsRR s (* dig will return CNAME, must recurse *)
102 | false => true) (* maybe also double check ip? use size s - 1 if so! *)
103
104 | (_, NONE) => false
105 end
106
107fun filterHosts (hosts, ipv6) =
108 List.filter (fn host => if (Domain.validIpv6 host orelse Domain.validIp host)
109 then
110 true
111 else
112 dnsExists ipv6 host)
113 hosts
114
115
1a03ee46 116fun formatPorts ports = "(" ^ String.concatWith " " (map Int.toString ports) ^ ")"
93278775 117fun formatHosts (hosts, ipv6) = "(" ^ String.concatWith " " (filterHosts (hosts, ipv6)) ^ ")"
1a03ee46 118
93278775 119fun formatOutputRule (Client (ports, hosts), ipv6) = "dport " ^ formatPorts ports ^ (case hosts of
1a03ee46 120 [] => ""
93278775 121 | _ => " daddr " ^ formatHosts (hosts, ipv6)) ^ " ACCEPT;"
f3b84aff 122 | formatOutputRule _ = ""
1a03ee46 123
93278775 124fun formatInputRule (Server (ports, hosts), ipv6) = "dport " ^ formatPorts ports ^ (case hosts of
1a03ee46 125 [] => ""
93278775 126 | _ => " saddr " ^ formatHosts (hosts, ipv6)) ^ " ACCEPT;"
f3b84aff 127 | formatInputRule _ = ""
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128
129type ferm_lines = { input_rules : (string list) DataStructures.StringMap.map,
93278775 130 output_rules : (string list) DataStructures.StringMap.map }
1a03ee46 131
93278775 132fun generateNodeFermRules rules =
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133 let
134 fun filter_node_rules rules =
93278775 135 List.filter (fn (uname, FirewallNode node, rule) => node = Slave.hostname () orelse case rule of
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136 ProxiedServer _ => List.exists (fn (h,_) => h = Slave.hostname ()) Config.Apache.webNodes_all
137 | _ => false)
138 rules
f9548f16 139
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140 val inputLines = ref StringMap.empty
141 val outputLines = ref StringMap.empty
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142 val inputLines_v6 = ref StringMap.empty
143 val outputLines_v6 = ref StringMap.empty
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144
145 fun confLine r (User uname, line) =
146 let
147 val line = "\t" ^ line ^ "\n"
148 val lines = case StringMap.find (!r, uname) of
149 NONE => []
150 | SOME lines => lines
151 in
152 r := StringMap.insert (!r, uname, line :: lines)
153 end
154
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155 fun confLine_in (uname, rule) = confLine inputLines (uname, formatInputRule (rule, FwIPv4))
156 fun confLine_out (uname, rule) = confLine outputLines (uname, formatOutputRule (rule, FwIPv4))
157 fun confLine_in_v6 (uname, rule) = confLine inputLines_v6 (uname, formatInputRule (rule, FwIPv6))
158 fun confLine_out_v6 (uname, rule) = confLine outputLines_v6 (uname, formatOutputRule (rule, FwIPv6))
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159
160 fun insertConfLine (uname, ruleNode, rule) =
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161 case rule of
162 Client (ports, hosts) => (confLine_out (uname, rule); confLine_out_v6 (uname, rule))
163 | Server (ports, hosts) => (confLine_in (uname, rule); confLine_in_v6 (uname, rule))
164 | LocalServer ports => (insertConfLine (uname, ruleNode, Client (ports, ["127.0.0.1/8", ":::1"]));
165 insertConfLine (uname, ruleNode, Server (ports, ["127.0.0.1/8", ":::1"])))
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166 | ProxiedServer ports => if (fn FirewallNode r => r) ruleNode = Slave.hostname () then
167 (insertConfLine (uname, ruleNode, Server (ports, ["$WEBNODES"]));
168 insertConfLine (uname, ruleNode, Client (ports, [(fn FirewallNode r => r) ruleNode])))
169 else (* we are a web server *)
170 (insertConfLine (uname, ruleNode, Client (ports, [(fn FirewallNode r => r) ruleNode]));
171 insertConfLine (User "www-data", ruleNode, Client (ports, [(fn FirewallNode r => r) ruleNode])))
172
173 val _ = map insertConfLine (filter_node_rules rules)
174 in
175 { input_rules = !inputLines,
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176 output_rules = !outputLines,
177 input6_rules = !inputLines_v6,
178 output6_rules = !outputLines_v6 }
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179
180
181 end
182
183fun generateFirewallConfig rules =
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184 (* rule generation must happen on the node (mandating the even
185 service users be pts users would make it possible to do on the
186 server, but that's not happening any time soon) *)
ec95f39f 187 let
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188 val users_tcp_out_conf = TextIO.openOut (Config.Firewall.firewallDir ^ "/users_tcp_out.conf")
189 val users_tcp_in_conf = TextIO.openOut (Config.Firewall.firewallDir ^ "/users_tcp_in.conf")
1a03ee46 190
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191 val users_tcp6_out_conf = TextIO.openOut (Config.Firewall.firewallDir ^ "/users_tcp6_out.conf")
192 val users_tcp6_in_conf = TextIO.openOut (Config.Firewall.firewallDir ^ "/users_tcp6_in.conf")
93278775 193
1a03ee46 194 val nodeFermRules = generateNodeFermRules rules
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195
196 fun write_tcp_in_conf_preamble outf =
197 (* no ipv6 support yet, but use @ipfilter() in ferm to prepare *)
198 TextIO.output (outf, String.concat ["@def $WEBNODES = @ipfilter((",
199 (String.concatWith " " (List.map (fn (_, ip) => ip)
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200 (List.filter (fn (node, _) => List.exists (fn (n) => n = node) (List.map (fn (node, _) => node) (Config.Apache.webNodes_all @ Config.Apache.webNodes_admin)))
201 Config.nodeIps))),
93278775 202 "));\n\n"])
1a03ee46 203
93278775 204 fun writeUserInRules tcp_inf (uname, lines) =
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205 (* We can't match the user when listening; SELinux or
206 similar would let us manage this with better
207 granularity.*)
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208 let
209 val _ = SysWord.toInt (Posix.ProcEnv.uidToWord (Posix.SysDB.Passwd.uid (Posix.SysDB.getpwnam uname)))
210 in
1933c596 211 TextIO.output (tcp_inf, "proto tcp mod comment comment \"user:" ^ uname ^ "\" {\n");
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212 TextIO.output (tcp_inf, concat lines);
213 TextIO.output (tcp_inf, "\n}\n\n")
214 end handle OS.SysErr _ => print "Invalid user in firewall config, skipping.\n" (* no sense in opening ports for bad users *)
1a03ee46 215
1933c596 216 fun writeUserOutRules tcp_outf (uname, lines) =
acef55cc 217 let
1a03ee46 218 val uid = SysWord.toInt (Posix.ProcEnv.uidToWord (Posix.SysDB.Passwd.uid (Posix.SysDB.getpwnam uname)))
acef55cc 219 in
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220 TextIO.output (tcp_outf, "mod owner uid-owner " ^ (Int.toString uid) ^ " mod comment comment \"user:" ^ uname ^ "\" proto tcp {\n");
221 TextIO.output (tcp_outf, concat lines);
222 TextIO.output (tcp_outf, "\nDROP;\n}\n\n")
1a03ee46 223 end handle OS.SysErr _ => print "Invalid user in firewall config, skipping.\n"
93278775 224
ec95f39f 225 in
1a03ee46 226 write_tcp_in_conf_preamble (users_tcp_in_conf);
1933c596 227 StringMap.appi (writeUserOutRules users_tcp_out_conf) (#output_rules nodeFermRules);
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228 StringMap.appi (writeUserInRules users_tcp_in_conf) (#input_rules nodeFermRules);
229
230 write_tcp_in_conf_preamble (users_tcp6_in_conf);
1933c596 231 StringMap.appi (writeUserOutRules users_tcp6_out_conf) (#output6_rules nodeFermRules);
93278775 232 StringMap.appi (writeUserInRules users_tcp6_in_conf) (#input6_rules nodeFermRules);
f9548f16 233
ec95f39f 234 TextIO.closeOut users_tcp_out_conf;
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235 TextIO.closeOut users_tcp_in_conf;
236
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237 TextIO.closeOut users_tcp6_out_conf;
238 TextIO.closeOut users_tcp6_in_conf;
239
73b95423 240 true
ec95f39f 241 end
73b95423 242
1933c596 243
93278775 244fun publishConfig _ =
73b95423 245 Slave.shell [Config.Firewall.reload]
f9548f16 246end