From 8152505ea3793037984a7f3349ac95cc20c4e44c Mon Sep 17 00:00:00 2001 From: Raimo Niskanen Date: Mon, 27 May 2013 16:41:59 +0200 Subject: Improve case (in)sensitivity for host lookups --- lib/kernel/src/inet.erl | 41 +++++++++++++++++---------- lib/kernel/src/inet_db.erl | 65 +++++++++++++++++++++++-------------------- lib/kernel/src/inet_hosts.erl | 9 ++++-- lib/kernel/src/inet_res.erl | 6 ++-- 4 files changed, 71 insertions(+), 50 deletions(-) (limited to 'lib/kernel') diff --git a/lib/kernel/src/inet.erl b/lib/kernel/src/inet.erl index aada1252ad..3ea530a366 100644 --- a/lib/kernel/src/inet.erl +++ b/lib/kernel/src/inet.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1997-2012. All Rights Reserved. +%% Copyright Ericsson AB 1997-2013. All Rights Reserved. %% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in @@ -947,21 +947,34 @@ gethostbyname_self(Name, Type) when is_atom(Name) -> gethostbyname_self(Name, Type) when is_list(Name), Type =:= inet; is_list(Name), Type =:= inet6 -> - case inet_db:gethostname() of - Name -> - {ok,make_hostent(Name, - [translate_ip(loopback, Type)], - [], Type)}; - Self -> + N = inet_db:tolower(Name), + Self = inet_db:gethostname(), + %% + %% This is the final fallback that pretends /etc/hosts has got + %% a line for the hostname on the loopback address. + %% Lookups into /etc/hosts are case insensitive and return + %% what is in the file. Therefore the letter case may differ between + %% the returned hostent record and the hostname that was asked for. + %% + case inet_db:tolower(Self) of + N -> + {ok, + make_hostent( + Self, [translate_ip(loopback, Type)], [], Type)}; + _ -> case inet_db:res_option(domain) of - "" -> {error,nxdomain}; + "" -> + {error,nxdomain}; Domain -> - case lists:append([Self,".",Domain]) of - Name -> - {ok,make_hostent(Name, - [translate_ip(loopback, Type)], - [], Type)}; - _ -> {error,nxdomain} + FQDN = lists:append([Self,".",Domain]), + case inet_db:tolower(FQDN) of + N -> + {ok, + make_hostent( + FQDN, + [translate_ip(loopback, Type)], [], Type)}; + _ -> + {error,nxdomain} end end end; diff --git a/lib/kernel/src/inet_db.erl b/lib/kernel/src/inet_db.erl index d4749b9756..a7679c531b 100644 --- a/lib/kernel/src/inet_db.erl +++ b/lib/kernel/src/inet_db.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1997-2010. All Rights Reserved. +%% Copyright Ericsson AB 1997-2013. All Rights Reserved. %% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in @@ -845,7 +845,8 @@ init([]) -> process_flag(trap_exit, true), Db = ets:new(inet_db, [public, named_table]), reset_db(Db), - Cache = ets:new(inet_cache, [public, bag, {keypos,2}, named_table]), + CacheOpts = [public, bag, {keypos,#dns_rr.domain}, named_table], + Cache = ets:new(inet_cache, CacheOpts), BynameOpts = [protected, bag, named_table, {keypos,1}], ByaddrOpts = [protected, bag, named_table, {keypos,3}], HostsByname = ets:new(inet_hosts_byname, BynameOpts), @@ -901,15 +902,21 @@ reset_db(Db) -> handle_call(Request, From, #state{db=Db}=State) -> case Request of {load_hosts_file,IPNmAs} when is_list(IPNmAs) -> - NIPs = lists:flatten([ [{N,if tuple_size(IP) =:= 4 -> inet; - tuple_size(IP) =:= 8 -> inet6 - end,IP} || N <- [Nm|As]] - || {IP,Nm,As} <- IPNmAs]), + NIPs = + lists:flatten( + [ [{N, + if tuple_size(IP) =:= 4 -> inet; + tuple_size(IP) =:= 8 -> inet6 + end,IP} || N <- [Nm|As]] + || {IP,Nm,As} <- IPNmAs]), Byname = State#state.hosts_file_byname, Byaddr = State#state.hosts_file_byaddr, ets:delete_all_objects(Byname), ets:delete_all_objects(Byaddr), - ets:insert(Byname, NIPs), + %% Byname has lowercased names while Byaddr keep the name casing. + %% This is to be able to reconstruct the original + %% /etc/hosts entry. + ets:insert(Byname, [{tolower(N),Type,IP} || {N,Type,IP} <- NIPs]), ets:insert(Byaddr, NIPs), {reply, ok, State}; @@ -938,16 +945,14 @@ handle_call(Request, From, #state{db=Db}=State) -> {reply, ok, State}; {add_rr, RR} when is_record(RR, dns_rr) -> - RR1 = lower_rr(RR), - ?dbg("add_rr: ~p~n", [RR1]), - do_add_rr(RR1, Db, State), + ?dbg("add_rr: ~p~n", [RR]), + do_add_rr(RR, Db, State), {reply, ok, State}; {del_rr, RR} when is_record(RR, dns_rr) -> - RR1 = lower_rr(RR), %% note. del_rr will handle wildcards !!! Cache = State#state.cache, - ets:match_delete(Cache, RR1), + ets:match_delete(Cache, RR), {reply, ok, State}; {lookup_rr, Domain, Class, Type} -> @@ -1225,15 +1230,18 @@ handle_set_file(ParseFun, Bin, From, State) -> handle_rc_list(Opts, From, State) end. +%% Byname has lowercased names while Byaddr keep the name casing. +%% This is to be able to reconstruct the original /etc/hosts entry. + do_add_host(Byname, Byaddr, Names, Type, IP) -> do_del_host(Byname, Byaddr, IP), - NIPs = [{tolower(N),Type,IP} || N <- Names], - ets:insert(Byname, NIPs), - ets:insert(Byaddr, NIPs), + ets:insert(Byname, [{tolower(N),Type,IP} || N <- Names]), + ets:insert(Byaddr, [{N,Type,IP} || N <- Names]), ok. do_del_host(Byname, Byaddr, IP) -> - [ets:delete_object(Byname, NIP) || NIP <- ets:lookup(Byaddr, IP)], + [ets:delete_object(Byname, {tolower(Name),Type,Addr}) || + {Name,Type,Addr} <- ets:lookup(Byaddr, IP)], ets:delete(Byaddr, IP), ok. @@ -1369,7 +1377,7 @@ times() -> %% lookup and remove old entries do_lookup_rr(Domain, Class, Type) -> - match_rr(#dns_rr{domain = tolower(Domain), class = Class,type = Type, + match_rr(#dns_rr{domain = Domain, class = Class,type = Type, cnt = '_', tm = '_', ttl = '_', bm = '_', func = '_', data = '_'}). @@ -1393,23 +1401,20 @@ filter_rr([], _Time) -> []. %% -%% Lower case the domain name before storage -%% -lower_rr(RR) -> - Dn = RR#dns_rr.domain, - if is_list(Dn) -> - RR#dns_rr { domain = tolower(Dn) }; - true -> RR - end. - +%% Case fold upper-case to lower-case according to RFC 4343 +%% "Domain Name System (DNS) Case Insensitivity Clarification". %% -%% Map upper-case to lower-case %% NOTE: this code is in kernel and we don't want to relay -%% to much on stdlib +%% to much on stdlib. Furthermore string:to_lower/1 +%% does not follow RFC 4343. %% tolower([]) -> []; -tolower([C|Cs]) when C >= $A, C =< $Z -> [(C-$A)+$a|tolower(Cs)]; -tolower([C|Cs]) -> [C|tolower(Cs)]. +tolower([C|Cs]) when is_integer(C) -> + if C >= $A, C =< $Z -> + [(C-$A)+$a|tolower(Cs)]; + true -> + [C|tolower(Cs)] + end. dn_ip6_int(A,B,C,D,E,F,G,H) -> dnib(H) ++ dnib(G) ++ dnib(F) ++ dnib(E) ++ diff --git a/lib/kernel/src/inet_hosts.erl b/lib/kernel/src/inet_hosts.erl index df1d4fc0be..6e9719b4aa 100644 --- a/lib/kernel/src/inet_hosts.erl +++ b/lib/kernel/src/inet_hosts.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1997-2009. All Rights Reserved. +%% Copyright Ericsson AB 1997-2013. All Rights Reserved. %% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in @@ -38,9 +38,12 @@ gethostbyname(_) -> {error, formerr}. gethostbyname(Name, Type) when is_list(Name), is_atom(Type) -> - case gethostbyname(Name, Type, inet_hosts_byname, inet_hosts_byaddr) of + %% Byname has lowercased names while Byaddr keep the name casing. + %% This is to be able to reconstruct the original /etc/hosts entry. + N = inet_db:tolower(Name), + case gethostbyname(N, Type, inet_hosts_byname, inet_hosts_byaddr) of false -> - case gethostbyname(Name, Type, + case gethostbyname(N, Type, inet_hosts_file_byname, inet_hosts_file_byaddr) of false -> {error,nxdomain}; diff --git a/lib/kernel/src/inet_res.erl b/lib/kernel/src/inet_res.erl index 59ba408d7a..94a9f7c64d 100644 --- a/lib/kernel/src/inet_res.erl +++ b/lib/kernel/src/inet_res.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 1997-2011. All Rights Reserved. +%% Copyright Ericsson AB 1997-2013. All Rights Reserved. %% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in @@ -181,8 +181,8 @@ lookup(Name, Class, Type, Opts, Timeout) -> lookup_filter({ok,#dns_rec{anlist=Answers}}, Class, Type) -> [A#dns_rr.data || A <- Answers, - A#dns_rr.class =:= Class, - A#dns_rr.type =:= Type]; + Class =:= any orelse A#dns_rr.class =:= Class, + Type =:= any orelse A#dns_rr.type =:= Type]; lookup_filter({error,_}, _, _) -> []. %% -------------------------------------------------------------------------- -- cgit v1.2.3