X-Git-Url: https://git.hcoop.net/hcoop/domtool2.git/blobdiff_plain/f9548f1652232653178ffd9839b9cbbf7f87316b..1933c5961c1a98198f7b98f33085e61090346885:/src/plugins/firewall.sml diff --git a/src/plugins/firewall.sml b/src/plugins/firewall.sml index 6a4bb30..9ceaeea 100644 --- a/src/plugins/firewall.sml +++ b/src/plugins/firewall.sml @@ -1,5 +1,6 @@ (* HCoop Domtool (http://hcoop.sourceforge.net/) * Copyright (c) 2006-2007, Adam Chlipala + * Copyright (c) 2011,2012,2013,2014,2018 Clinton Ebadi * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -16,31 +17,230 @@ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. *) -(* Firewall rule querying *) +(* Firewall management *) + +(* Contains portions from Fwtool Copyright (C) 2005 Adam Chlipala, GPL v2 or later *) structure Firewall :> FIREWALL = struct -fun query uname = +datatype user = User of string + +datatype fwnode = FirewallNode of string + +datatype fwrule = Client of int list * string list + | Server of int list * string list + | ProxiedServer of int list + | LocalServer of int list + +type firewall_rules = (user * fwnode * fwrule) list + +datatype fwip = FwIPv4 + | FwIPv6 + +structure StringMap = DataStructures.StringMap + +fun parseRules () = + let + val inf = TextIO.openIn Config.Firewall.firewallRules + + fun parsePorts ports = + List.mapPartial Int.fromString (String.fields (fn ch => ch = #",") ports) + (* Just drop bad ports for now *) + + fun parseNodes nodes = String.fields (fn ch => ch = #",") nodes + + fun loop parsedRules = + case TextIO.inputLine inf of + NONE => parsedRules + | SOME line => + case String.tokens Char.isSpace line of + nodes :: uname :: rest => + let + val nodes = parseNodes nodes + in + case rest of + "Client" :: ports :: hosts => loop (map (fn node => (User uname, FirewallNode node, Client (parsePorts ports, hosts))) nodes) @ parsedRules + | "Server" :: ports :: hosts => loop (map (fn node => (User uname, FirewallNode node, Server (parsePorts ports, hosts))) nodes) @ parsedRules + | ["ProxiedServer", ports] => loop (map (fn node => (User uname, FirewallNode node, ProxiedServer (parsePorts ports))) nodes) @ parsedRules + | ["LocalServer", ports] => loop (map (fn node => (User uname, FirewallNode node, LocalServer (parsePorts ports))) nodes) @ parsedRules + | _ => (print "Invalid config line\n"; loop parsedRules) + end + | _ => loop parsedRules + in + loop [] + end + +fun formatQueryRule (Client (ports, hosts)) = + "Client " ^ String.concatWith "," (map Int.toString ports) ^ " " ^ String.concatWith " " hosts + | formatQueryRule (Server (ports, hosts)) = + "Server " ^ String.concatWith "," (map Int.toString ports) ^ " " ^ String.concatWith " " hosts + | formatQueryRule (ProxiedServer ports) = + "ProxiedServer " ^ String.concatWith "," (map Int.toString ports) + | formatQueryRule (LocalServer ports) = + "LocalServer " ^ String.concatWith "," (map Int.toString ports) + +fun query (node, uname) = + (* completely broken *) + let + val rules = parseRules () + in + map (fn (_, _, r) => formatQueryRule r) + (List.filter (fn (User u, FirewallNode n, _) => u = uname andalso n = node) rules) + end + +fun dnsExists dnsRR dnsRecord = let - val inf = TextIO.openIn "/etc/firewall/users.rules" - - fun loop rules = - case TextIO.inputLine inf of - NONE => List.rev rules - | SOME line => - if String.sub (line, 0) = #"#" then - loop rules - else case String.tokens Char.isSpace line of - uname'::rest => - if uname = uname' then - loop (String.concatWith " " rest :: rules) - else - loop rules - | _ => loop rules + val dnsRR_string = case dnsRR of + FwIPv6 => "AAAA" + | FwIPv4 => "A" in - loop [] - before TextIO.closeIn inf - end handle IO.Io _ => [] + (* timeout chosen arbitrarilty, shorter is better if it's reliable *) + (* dig outputs true even if the lookup fails, but no output in short mode should work *) + case Slave.runOutput (Config.Firewall.dig, ["+short", "+timeout=3", "-t", dnsRR_string, dnsRecord]) of + (_, SOME s) => (case Domain.validDomain (substring (s, 0, size s - 2)) of (* delete trailing . from cname *) + true => dnsExists dnsRR s (* dig will return CNAME, must recurse *) + | false => true) (* maybe also double check ip? use size s - 1 if so! *) + + | (_, NONE) => false + end + +fun filterHosts (hosts, ipv6) = + List.filter (fn host => if (Domain.validIpv6 host orelse Domain.validIp host) + then + true + else + dnsExists ipv6 host) + hosts + + +fun formatPorts ports = "(" ^ String.concatWith " " (map Int.toString ports) ^ ")" +fun formatHosts (hosts, ipv6) = "(" ^ String.concatWith " " (filterHosts (hosts, ipv6)) ^ ")" + +fun formatOutputRule (Client (ports, hosts), ipv6) = "dport " ^ formatPorts ports ^ (case hosts of + [] => "" + | _ => " daddr " ^ formatHosts (hosts, ipv6)) ^ " ACCEPT;" + | formatOutputRule _ = "" + +fun formatInputRule (Server (ports, hosts), ipv6) = "dport " ^ formatPorts ports ^ (case hosts of + [] => "" + | _ => " saddr " ^ formatHosts (hosts, ipv6)) ^ " ACCEPT;" + | formatInputRule _ = "" + +type ferm_lines = { input_rules : (string list) DataStructures.StringMap.map, + output_rules : (string list) DataStructures.StringMap.map } + +fun generateNodeFermRules rules = + let + fun filter_node_rules rules = + List.filter (fn (uname, FirewallNode node, rule) => node = Slave.hostname () orelse case rule of + ProxiedServer _ => List.exists (fn (h,_) => h = Slave.hostname ()) Config.Apache.webNodes_all + | _ => false) + rules + + val inputLines = ref StringMap.empty + val outputLines = ref StringMap.empty + val inputLines_v6 = ref StringMap.empty + val outputLines_v6 = ref StringMap.empty + + fun confLine r (User uname, line) = + let + val line = "\t" ^ line ^ "\n" + val lines = case StringMap.find (!r, uname) of + NONE => [] + | SOME lines => lines + in + r := StringMap.insert (!r, uname, line :: lines) + end + + fun confLine_in (uname, rule) = confLine inputLines (uname, formatInputRule (rule, FwIPv4)) + fun confLine_out (uname, rule) = confLine outputLines (uname, formatOutputRule (rule, FwIPv4)) + fun confLine_in_v6 (uname, rule) = confLine inputLines_v6 (uname, formatInputRule (rule, FwIPv6)) + fun confLine_out_v6 (uname, rule) = confLine outputLines_v6 (uname, formatOutputRule (rule, FwIPv6)) + + fun insertConfLine (uname, ruleNode, rule) = + case rule of + Client (ports, hosts) => (confLine_out (uname, rule); confLine_out_v6 (uname, rule)) + | Server (ports, hosts) => (confLine_in (uname, rule); confLine_in_v6 (uname, rule)) + | LocalServer ports => (insertConfLine (uname, ruleNode, Client (ports, ["127.0.0.1/8", ":::1"])); + insertConfLine (uname, ruleNode, Server (ports, ["127.0.0.1/8", ":::1"]))) + | ProxiedServer ports => if (fn FirewallNode r => r) ruleNode = Slave.hostname () then + (insertConfLine (uname, ruleNode, Server (ports, ["$WEBNODES"])); + insertConfLine (uname, ruleNode, Client (ports, [(fn FirewallNode r => r) ruleNode]))) + else (* we are a web server *) + (insertConfLine (uname, ruleNode, Client (ports, [(fn FirewallNode r => r) ruleNode])); + insertConfLine (User "www-data", ruleNode, Client (ports, [(fn FirewallNode r => r) ruleNode]))) + + val _ = map insertConfLine (filter_node_rules rules) + in + { input_rules = !inputLines, + output_rules = !outputLines, + input6_rules = !inputLines_v6, + output6_rules = !outputLines_v6 } + + + end + +fun generateFirewallConfig rules = + (* rule generation must happen on the node (mandating the even + service users be pts users would make it possible to do on the + server, but that's not happening any time soon) *) + let + val users_tcp_out_conf = TextIO.openOut (Config.Firewall.firewallDir ^ "/users_tcp_out.conf") + val users_tcp_in_conf = TextIO.openOut (Config.Firewall.firewallDir ^ "/users_tcp_in.conf") + + val users_tcp6_out_conf = TextIO.openOut (Config.Firewall.firewallDir ^ "/users_tcp6_out.conf") + val users_tcp6_in_conf = TextIO.openOut (Config.Firewall.firewallDir ^ "/users_tcp6_in.conf") + + val nodeFermRules = generateNodeFermRules rules + + fun write_tcp_in_conf_preamble outf = + (* no ipv6 support yet, but use @ipfilter() in ferm to prepare *) + TextIO.output (outf, String.concat ["@def $WEBNODES = @ipfilter((", + (String.concatWith " " (List.map (fn (_, ip) => ip) + (List.filter (fn (node, _) => List.exists (fn (n) => n = node) (List.map (fn (node, _) => node) (Config.Apache.webNodes_all @ Config.Apache.webNodes_admin))) + Config.nodeIps))), + "));\n\n"]) + + fun writeUserInRules tcp_inf (uname, lines) = + (* We can't match the user when listening; SELinux or + similar would let us manage this with better + granularity.*) + let + val _ = SysWord.toInt (Posix.ProcEnv.uidToWord (Posix.SysDB.Passwd.uid (Posix.SysDB.getpwnam uname))) + in + TextIO.output (tcp_inf, "proto tcp mod comment comment \"user:" ^ uname ^ "\" {\n"); + TextIO.output (tcp_inf, concat lines); + TextIO.output (tcp_inf, "\n}\n\n") + end handle OS.SysErr _ => print "Invalid user in firewall config, skipping.\n" (* no sense in opening ports for bad users *) + + fun writeUserOutRules tcp_outf (uname, lines) = + let + val uid = SysWord.toInt (Posix.ProcEnv.uidToWord (Posix.SysDB.Passwd.uid (Posix.SysDB.getpwnam uname))) + in + TextIO.output (tcp_outf, "mod owner uid-owner " ^ (Int.toString uid) ^ " mod comment comment \"user:" ^ uname ^ "\" proto tcp {\n"); + TextIO.output (tcp_outf, concat lines); + TextIO.output (tcp_outf, "\nDROP;\n}\n\n") + end handle OS.SysErr _ => print "Invalid user in firewall config, skipping.\n" + + in + write_tcp_in_conf_preamble (users_tcp_in_conf); + StringMap.appi (writeUserOutRules users_tcp_out_conf) (#output_rules nodeFermRules); + StringMap.appi (writeUserInRules users_tcp_in_conf) (#input_rules nodeFermRules); + + write_tcp_in_conf_preamble (users_tcp6_in_conf); + StringMap.appi (writeUserOutRules users_tcp6_out_conf) (#output6_rules nodeFermRules); + StringMap.appi (writeUserInRules users_tcp6_in_conf) (#input6_rules nodeFermRules); + + TextIO.closeOut users_tcp_out_conf; + TextIO.closeOut users_tcp_in_conf; + + TextIO.closeOut users_tcp6_out_conf; + TextIO.closeOut users_tcp6_in_conf; + + true + end +fun publishConfig _ = + Slave.shell [Config.Firewall.reload] end