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-rw-r--r--lib/kernel/src/inet_res.erl379
1 files changed, 293 insertions, 86 deletions
diff --git a/lib/kernel/src/inet_res.erl b/lib/kernel/src/inet_res.erl
index de0f23bf24..2276ddcd08 100644
--- a/lib/kernel/src/inet_res.erl
+++ b/lib/kernel/src/inet_res.erl
@@ -1,7 +1,7 @@
%%
%% %CopyrightBegin%
%%
-%% Copyright Ericsson AB 1997-2010. All Rights Reserved.
+%% Copyright Ericsson AB 1997-2011. 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
@@ -47,18 +47,93 @@
false -> ok
end).
+-type res_option() ::
+ {alt_nameservers, [nameserver()]}
+ | {edns, 0 | false}
+ | {inet6, boolean()}
+ | {nameservers, [nameserver()]}
+ | {recurse, boolean()}
+ | {retry, integer()}
+ | {timeout, integer()}
+ | {udp_payload_size, integer()}
+ | {usevc, boolean()}.
+
+-type nameserver() :: {inet:ip_address(), Port :: 1..65535}.
+
+-type res_error() :: formerr | qfmterror | servfail | nxdomain |
+ notimp | refused | badvers | timeout.
+
+-type dns_name() :: string().
+
+-type rr_type() :: a | aaaa | cname | gid | hinfo | ns | mb | md | mg | mf
+ | minfo | mx | naptr | null | ptr | soa | spf | srv | txt
+ | uid | uinfo | unspec | wks.
+
+-type dns_class() :: in | chaos | hs | any.
+
+-opaque dns_msg() :: term().
+
+-type dns_data() ::
+ dns_name()
+ | inet:ip4_address()
+ | inet:ip6_address()
+ | {MName :: dns_name(),
+ RName :: dns_name(),
+ Serial :: integer(),
+ Refresh :: integer(),
+ Retry :: integer(),
+ Expiry :: integer(),
+ Minimum :: integer()}
+ | {inet:ip4_address(), Proto :: integer(), BitMap :: binary()}
+ | {CpuString :: string(), OsString :: string()}
+ | {RM :: dns_name(), EM :: dns_name()}
+ | {Prio :: integer(), dns_name()}
+ | {Prio :: integer(),Weight :: integer(),Port :: integer(),dns_name()}
+ | {Order :: integer(),Preference :: integer(),Flags :: string(),
+ Services :: string(),Regexp :: string(), dns_name()}
+ | [string()]
+ | binary().
+
%% --------------------------------------------------------------------------
%% resolve:
%%
%% Nameserver query
%%
+-spec resolve(Name, Class, Type) -> {ok, dns_msg()} | Error when
+ Name :: dns_name() | inet:ip_address(),
+ Class :: dns_class(),
+ Type :: rr_type(),
+ Error :: {error, Reason} | {error,{Reason,dns_msg()}},
+ Reason :: inet:posix() | res_error().
+
resolve(Name, Class, Type) ->
resolve(Name, Class, Type, [], infinity).
+-spec resolve(Name, Class, Type, Opts) ->
+ {ok, dns_msg()} | Error when
+ Name :: dns_name() | inet:ip_address(),
+ Class :: dns_class(),
+ Type :: rr_type(),
+ Opts :: [Opt],
+ Opt :: res_option() | verbose | atom(),
+ Error :: {error, Reason} | {error,{Reason,dns_msg()}},
+ Reason :: inet:posix() | res_error().
+
resolve(Name, Class, Type, Opts) ->
resolve(Name, Class, Type, Opts, infinity).
+-spec resolve(Name, Class, Type, Opts, Timeout) ->
+ {ok, dns_msg()} | Error when
+ Name :: dns_name() | inet:ip_address(),
+ Class :: dns_class(),
+ Type :: rr_type(),
+ Opts :: [Opt],
+ Opt :: res_option() | verbose | atom(),
+ Timeout :: timeout(),
+ Error :: {error, Reason} | {error,{Reason,dns_msg()}},
+ Reason :: inet:posix() | res_error().
+
resolve(Name, Class, Type, Opts, Timeout) ->
case nsdname(Name) of
{ok, Nm} ->
@@ -76,12 +151,30 @@ resolve(Name, Class, Type, Opts, Timeout) ->
%% Convenience wrapper to resolve/3,4,5 that filters out all answer data
%% fields of the class and type asked for.
+-spec lookup(Name, Class, Type) -> [dns_data()] when
+ Name :: dns_name() | inet:ip_address(),
+ Class :: dns_class(),
+ Type :: rr_type().
+
lookup(Name, Class, Type) ->
lookup(Name, Class, Type, []).
+-spec lookup(Name, Class, Type, Opts) -> [dns_data()] when
+ Name :: dns_name() | inet:ip_address(),
+ Class :: dns_class(),
+ Type :: rr_type(),
+ Opts :: [res_option() | verbose].
+
lookup(Name, Class, Type, Opts) ->
lookup(Name, Class, Type, Opts, infinity).
+-spec lookup(Name, Class, Type, Opts, Timeout) -> [dns_data()] when
+ Name :: dns_name() | inet:ip_address(),
+ Class :: dns_class(),
+ Type :: rr_type(),
+ Opts :: [res_option() | verbose],
+ Timeout :: timeout().
+
lookup(Name, Class, Type, Opts, Timeout) ->
lookup_filter(resolve(Name, Class, Type, Opts, Timeout),
Class, Type).
@@ -101,17 +194,55 @@ lookup_filter({error,_}, _, _) -> [].
%%
%% To be deprecated
+-spec nslookup(Name, Class, Type) -> {ok, dns_msg()} | {error, Reason} when
+ Name :: dns_name() | inet:ip_address(),
+ Class :: dns_class(),
+ Type :: rr_type(),
+ Reason :: inet:posix() | res_error().
+
nslookup(Name, Class, Type) ->
do_nslookup(Name, Class, Type, [], infinity).
+-spec nslookup(Name, Class, Type, Timeout) ->
+ {ok, dns_msg()} | {error, Reason} when
+ Name :: dns_name() | inet:ip_address(),
+ Class :: dns_class(),
+ Type :: rr_type(),
+ Timeout :: timeout(),
+ Reason :: inet:posix() | res_error();
+ (Name, Class, Type, Nameservers) ->
+ {ok, dns_msg()} | {error, Reason} when
+ Name :: dns_name() | inet:ip_address(),
+ Class :: dns_class(),
+ Type :: rr_type(),
+ Nameservers :: [nameserver()],
+ Reason :: inet:posix() | res_error().
+
nslookup(Name, Class, Type, Timeout) when is_integer(Timeout), Timeout >= 0 ->
do_nslookup(Name, Class, Type, [], Timeout);
nslookup(Name, Class, Type, NSs) -> % For backwards compatibility
nnslookup(Name, Class, Type, NSs). % with OTP R6B only
+-spec nnslookup(Name, Class, Type, Nameservers) ->
+ {ok, dns_msg()} | {error, Reason} when
+ Name :: dns_name() | inet:ip_address(),
+ Class :: dns_class(),
+ Type :: rr_type(),
+ Nameservers :: [nameserver()],
+ Reason :: inet:posix().
+
nnslookup(Name, Class, Type, NSs) ->
nnslookup(Name, Class, Type, NSs, infinity).
+-spec nnslookup(Name, Class, Type, Nameservers, Timeout) ->
+ {ok, dns_msg()} | {error, Reason} when
+ Name :: dns_name() | inet:ip_address(),
+ Class :: dns_class(),
+ Type :: rr_type(),
+ Timeout :: timeout(),
+ Nameservers :: [nameserver()],
+ Reason :: inet:posix().
+
nnslookup(Name, Class, Type, NSs, Timeout) ->
do_nslookup(Name, Class, Type, [{nameservers,NSs}], Timeout).
@@ -192,8 +323,19 @@ make_options(Opts, [Name|Names]) ->
%%
%% --------------------------------------------------------------------------
+-spec gethostbyaddr(Address) -> {ok, Hostent} | {error, Reason} when
+ Address :: inet:ip_address(),
+ Hostent :: inet:hostent(),
+ Reason :: inet:posix() | res_error().
+
gethostbyaddr(IP) -> gethostbyaddr_tm(IP,false).
+-spec gethostbyaddr(Address, Timeout) -> {ok, Hostent} | {error, Reason} when
+ Address :: inet:ip_address(),
+ Timeout :: timeout(),
+ Hostent :: inet:hostent(),
+ Reason :: inet:posix() | res_error().
+
gethostbyaddr(IP,Timeout) ->
Timer = inet:start_timer(Timeout),
Res = gethostbyaddr_tm(IP,Timer),
@@ -249,6 +391,11 @@ res_gethostbyaddr(Addr, IP, Timer) ->
%% Caches the answer.
%% --------------------------------------------------------------------------
+-spec gethostbyname(Name) -> {ok, Hostent} | {error, Reason} when
+ Name :: dns_name(),
+ Hostent :: inet:hostent(),
+ Reason :: inet:posix() | res_error().
+
gethostbyname(Name) ->
case inet_db:res_option(inet6) of
true ->
@@ -257,9 +404,23 @@ gethostbyname(Name) ->
gethostbyname_tm(Name, inet, false)
end.
+-spec gethostbyname(Name, Family) -> {ok, Hostent} | {error, Reason} when
+ Name :: dns_name(),
+ Hostent :: inet:hostent(),
+ Family :: inet:family_option(),
+ Reason :: inet:posix() | res_error().
+
gethostbyname(Name,Family) ->
gethostbyname_tm(Name,Family,false).
+-spec gethostbyname(Name, Family, Timeout) ->
+ {ok, Hostent} | {error, Reason} when
+ Name :: dns_name(),
+ Hostent :: inet:hostent(),
+ Timeout :: timeout(),
+ Family :: inet:family_option(),
+ Reason :: inet:posix() | res_error().
+
gethostbyname(Name,Family,Timeout) ->
Timer = inet:start_timer(Timeout),
Res = gethostbyname_tm(Name,Family,Timer),
@@ -298,14 +459,27 @@ gethostbyname_tm(_Name, _Family, _Timer) ->
%%
%% getbyname(domain_name(), Type) => {ok, hostent()} | {error, Reason}
%%
-%% where domain_name() is domain string or atom and Type is ?S_A, ?S_MX ...
+%% where domain_name() is domain string and Type is ?S_A, ?S_MX ...
%%
%% Caches the answer.
%% --------------------------------------------------------------------------
+-spec getbyname(Name, Type) -> {ok, Hostent} | {error, Reason} when
+ Name :: dns_name(),
+ Type :: rr_type(),
+ Hostent :: inet:hostent(),
+ Reason :: inet:posix() | res_error().
+
getbyname(Name, Type) ->
getbyname_tm(Name,Type,false).
+-spec getbyname(Name, Type, Timeout) -> {ok, Hostent} | {error, Reason} when
+ Name :: dns_name(),
+ Type :: rr_type(),
+ Timeout :: timeout(),
+ Hostent :: inet:hostent(),
+ Reason :: inet:posix() | res_error().
+
getbyname(Name, Type, Timeout) ->
Timer = inet:start_timer(Timeout),
Res = getbyname_tm(Name, Type, Timer),
@@ -539,27 +713,41 @@ udp_send(#sock{inet=I}, {A,B,C,D}=IP, Port, Buffer)
when ?ip(A,B,C,D), ?port(Port) ->
gen_udp:send(I, IP, Port, Buffer).
-udp_recv(#sock{inet6=I}, {A,B,C,D,E,F,G,H}=IP, Port, Timeout)
+udp_recv(#sock{inet6=I}, {A,B,C,D,E,F,G,H}=IP, Port, Timeout, Decode)
when ?ip6(A,B,C,D,E,F,G,H), ?port(Port) ->
- do_udp_recv(fun(T) -> gen_udp:recv(I, 0, T) end, IP, Port, Timeout);
-udp_recv(#sock{inet=I}, {A,B,C,D}=IP, Port, Timeout)
+ do_udp_recv(I, IP, Port, Timeout, Decode, erlang:now(), Timeout);
+udp_recv(#sock{inet=I}, {A,B,C,D}=IP, Port, Timeout, Decode)
when ?ip(A,B,C,D), ?port(Port) ->
- do_udp_recv(fun(T) -> gen_udp:recv(I, 0, T) end, IP, Port, Timeout).
-
-do_udp_recv(Recv, IP, Port, Timeout) ->
- do_udp_recv(Recv, IP, Port, Timeout,
- if Timeout =/= 0 -> erlang:now(); true -> undefined end).
-
-do_udp_recv(Recv, IP, Port, Timeout, Then) ->
- case Recv(Timeout) of
- {ok,{IP,Port,Answer}} ->
- {ok,Answer,erlang:max(0, Timeout - now_ms(erlang:now(), Then))};
- {ok,_} when Timeout =:= 0 ->
- {error,timeout};
- {ok,_} ->
- Now = erlang:now(),
- T = erlang:max(0, Timeout - now_ms(Now, Then)),
- do_udp_recv(Recv, IP, Port, T, Now);
+ do_udp_recv(I, IP, Port, Timeout, Decode, erlang:now(), Timeout).
+
+do_udp_recv(_I, _IP, _Port, 0, _Decode, _Start, _T) ->
+ timeout;
+do_udp_recv(I, IP, Port, Timeout, Decode, Start, T) ->
+ case gen_udp:recv(I, 0, T) of
+ {ok,Reply} ->
+ case Decode(Reply) of
+ false when T =:= 0 ->
+ %% This is a compromize between the hard way i.e
+ %% in the clause below if NewT becomes 0 bailout
+ %% immediately and risk that the right reply lies
+ %% ahead after some bad id replies, and the
+ %% forgiving way i.e go on with Timeout 0 until
+ %% the right reply comes or no reply (timeout)
+ %% which opens for a DOS attack by a malicious
+ %% DNS server flooding with bad id replies causing
+ %% an infinite loop here.
+ %%
+ %% Timeout is used as a sanity limit counter
+ %% just to put an end to the loop.
+ NewTimeout = erlang:max(0, Timeout - 50),
+ do_udp_recv(I, IP, Port, NewTimeout, Decode, Start, T);
+ false ->
+ Now = erlang:now(),
+ NewT = erlang:max(0, Timeout - now_ms(Now, Start)),
+ do_udp_recv(I, IP, Port, Timeout, Decode, Start, NewT);
+ Result ->
+ Result
+ end;
Error -> Error
end.
@@ -580,6 +768,17 @@ udp_close(#sock{inet=I,inet6=I6}) ->
%% end
%% end
%%
+%% But that man page also says dig always use num_servers = 1.
+%%
+%% Our man page says: timeout/retry, then double for next retry, i.e
+%% for i = 0 to retry - 1
+%% foreach nameserver
+%% send query
+%% wait((time * (2**i)) / retry)
+%% end
+%% end
+%%
+%% And that is what the code seems to do, now fixed, hopefully...
do_query(_Q, [], _Timer) ->
{error,nxdomain};
@@ -589,19 +788,16 @@ do_query(#q{options=#options{retry=Retry}}=Q, NSs, Timer) ->
query_retries(_Q, _NSs, _Timer, Retry, Retry, S) ->
udp_close(S),
{error,timeout};
+query_retries(_Q, [], _Timer, _Retry, _I, S) ->
+ udp_close(S),
+ {error,timeout};
query_retries(Q, NSs, Timer, Retry, I, S0) ->
- Num = length(NSs),
- if Num =:= 0 ->
- udp_close(S0),
- {error,timeout};
- true ->
- case query_nss(Q, NSs, Timer, Retry, I, S0, []) of
- {S,{noanswer,ErrNSs}} -> %% remove unreachable nameservers
- query_retries(Q, NSs--ErrNSs, Timer, Retry, I+1, S);
- {S,Result} ->
- udp_close(S),
- Result
- end
+ case query_nss(Q, NSs, Timer, Retry, I, S0, []) of
+ {S,{noanswer,ErrNSs}} -> %% remove unreachable nameservers
+ query_retries(Q, NSs--ErrNSs, Timer, Retry, I+1, S);
+ {S,Result} ->
+ udp_close(S),
+ Result
end.
query_nss(_Q, [], _Timer, _Retry, _I, S, ErrNSs) ->
@@ -611,13 +807,13 @@ query_nss(#q{edns=undefined}=Q, NSs, Timer, Retry, I, S, ErrNSs) ->
query_nss(Q, NSs, Timer, Retry, I, S, ErrNSs) ->
query_nss_edns(Q, NSs, Timer, Retry, I, S, ErrNSs).
-query_nss_edns(#q{options=#options{udp_payload_size=PSz}=Options,
- edns={Id,Buffer}}=Q,
- [{IP,Port}=NS|NSs]=NSs0, Timer, Retry, I, S0, ErrNSs) ->
- {S,Res}=Reply = query_ns(S0, Id, Buffer, IP, Port, Timer,
- Retry, I, Options, PSz),
+query_nss_edns(
+ #q{options=#options{udp_payload_size=PSz}=Options,edns={Id,Buffer}}=Q,
+ [{IP,Port}=NS|NSs]=NSs0, Timer, Retry, I, S0, ErrNSs) ->
+ {S,Res}=Reply =
+ query_ns(S0, Id, Buffer, IP, Port, Timer, Retry, I, Options, PSz),
case Res of
- timeout -> {S,{error,timeout}};
+ timeout -> {S,{error,timeout}}; % Bailout timeout
{ok,_} -> Reply;
{error,{nxdomain,_}} -> Reply;
{error,{E,_}} when E =:= qfmterror; E =:= notimp; E =:= servfail;
@@ -629,17 +825,19 @@ query_nss_edns(#q{options=#options{udp_payload_size=PSz}=Options,
query_nss(Q, NSs, Timer, Retry, I, S, ErrNSs)
end.
-query_nss_dns(#q{dns=Qdns}=Q0, [{IP,Port}=NS|NSs],
- Timer, Retry, I, S0, ErrNSs) ->
+query_nss_dns(
+ #q{dns=Qdns}=Q0,
+ [{IP,Port}=NS|NSs], Timer, Retry, I, S0, ErrNSs) ->
#q{options=Options,dns={Id,Buffer}}=Q =
if
is_function(Qdns, 0) -> Q0#q{dns=Qdns()};
true -> Q0
end,
- {S,Res}=Reply = query_ns(S0, Id, Buffer, IP, Port, Timer,
- Retry, I, Options, ?PACKETSZ),
+ {S,Res}=Reply =
+ query_ns(
+ S0, Id, Buffer, IP, Port, Timer, Retry, I, Options, ?PACKETSZ),
case Res of
- timeout -> {S,{error,timeout}};
+ timeout -> {S,{error,timeout}}; % Bailout timeout
{ok,_} -> Reply;
{error,{E,_}} when E =:= nxdomain; E =:= qfmterror -> Reply;
{error,E} when E =:= fmt; E =:= enetunreach; E =:= econnrefused ->
@@ -653,48 +851,66 @@ query_ns(S0, Id, Buffer, IP, Port, Timer, Retry, I,
PSz) ->
case UseVC orelse iolist_size(Buffer) > PSz of
true ->
- {S0,query_tcp(Tm, Id, Buffer, IP, Port, Timer, Verbose)};
+ TcpTimeout = inet:timeout(Tm*5, Timer),
+ {S0,query_tcp(TcpTimeout, Id, Buffer, IP, Port, Verbose)};
false ->
case udp_open(S0, IP) of
{ok,S} ->
- {S,case query_udp(S, Id, Buffer, IP, Port, Timer,
- Retry, I, Tm, Verbose) of
- {ok,#dns_rec{header=H}} when H#dns_header.tc ->
- query_tcp(Tm, Id, Buffer,
- IP, Port, Timer, Verbose);
- Reply -> Reply
- end};
+ Timeout =
+ inet:timeout( (Tm * (1 bsl I)) div Retry, Timer),
+ {S,
+ case query_udp(
+ S, Id, Buffer, IP, Port, Timeout, Verbose) of
+ {ok,#dns_rec{header=H}} when H#dns_header.tc ->
+ TcpTimeout = inet:timeout(Tm*5, Timer),
+ query_tcp(
+ TcpTimeout, Id, Buffer, IP, Port, Verbose);
+ Reply -> Reply
+ end};
Error ->
{S0,Error}
end
end.
-query_udp(S, Id, Buffer, IP, Port, Timer, Retry, I, Tm, Verbose) ->
- Timeout = inet:timeout( (Tm * (1 bsl I)) div Retry, Timer),
+query_udp(_S, _Id, _Buffer, _IP, _Port, 0, _Verbose) ->
+ timeout;
+query_udp(S, Id, Buffer, IP, Port, Timeout, Verbose) ->
?verbose(Verbose, "Try UDP server : ~p:~p (timeout=~w)\n",
- [IP, Port, Timeout]),
- udp_connect(S, IP, Port),
- udp_send(S, IP, Port, Buffer),
- query_udp_recv(S, IP, Port, Id, Timeout, Verbose).
-
-query_udp_recv(S, IP, Port, Id, Timeout, Verbose) ->
- case udp_recv(S, IP, Port, Timeout) of
- {ok,Answer,T} ->
- case decode_answer(Answer, Id, Verbose) of
- {error, badid} ->
- query_udp_recv(S, IP, Port, Id, T, Verbose);
- Reply -> Reply
+ [IP,Port,Timeout]),
+ case
+ case udp_connect(S, IP, Port) of
+ ok ->
+ udp_send(S, IP, Port, Buffer);
+ E1 ->
+ E1 end of
+ ok ->
+ Decode =
+ fun ({RecIP,RecPort,Answer})
+ when RecIP =:= IP, RecPort =:= Port ->
+ case decode_answer(Answer, Id, Verbose) of
+ {error,badid} ->
+ false;
+ Reply ->
+ Reply
+ end;
+ ({_,_,_}) ->
+ false
+ end,
+ case udp_recv(S, IP, Port, Timeout, Decode) of
+ {ok,_}=Result ->
+ Result;
+ E2 ->
+ ?verbose(Verbose, "UDP server error: ~p\n", [E2]),
+ E2
end;
- {error, timeout} when Timeout =:= 0 ->
- ?verbose(Verbose, "UDP server timeout\n", []),
- timeout;
- Error ->
- ?verbose(Verbose, "UDP server error: ~p\n", [Error]),
- Error
+ E3 ->
+ ?verbose(Verbose, "UDP send failed: ~p\n", [E3]),
+ {error,econnrefused}
end.
-query_tcp(Tm, Id, Buffer, IP, Port, Timer, Verbose) ->
- Timeout = inet:timeout(Tm*5, Timer),
+query_tcp(0, _Id, _Buffer, _IP, _Port, _Verbose) ->
+ timeout;
+query_tcp(Timeout, Id, Buffer, IP, Port, Verbose) ->
?verbose(Verbose, "Try TCP server : ~p:~p (timeout=~w)\n",
[IP, Port, Timeout]),
Family = case IP of
@@ -716,19 +932,10 @@ query_tcp(Tm, Id, Buffer, IP, Port, Timer, Verbose) ->
end;
Error ->
gen_tcp:close(S),
- case Error of
- {error, timeout} when Timeout =:= 0 ->
- ?verbose(Verbose, "TCP server recv timeout\n", []),
- timeout;
- _ ->
- ?verbose(Verbose, "TCP server recv error: ~p\n",
- [Error]),
- Error
- end
+ ?verbose(Verbose, "TCP server recv error: ~p\n",
+ [Error]),
+ Error
end;
- {error, timeout} when Timeout =:= 0 ->
- ?verbose(Verbose, "TCP server connect timeout\n", []),
- timeout;
Error ->
?verbose(Verbose, "TCP server error: ~p\n", [Error]),
Error
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-11 07:35:23 +0000