%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2006-2012. 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
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
%%
%% This is from chapter 3, Syntax Components, of RFC 3986:
%%
%% The generic URI syntax consists of a hierarchical sequence of
%% components referred to as the scheme, authority, path, query, and
%% fragment.
%%
%% URI = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
%%
%% hier-part = "//" authority path-abempty
%% / path-absolute
%% / path-rootless
%% / path-empty
%%
%% The scheme and path components are required, though the path may be
%% empty (no characters). When authority is present, the path must
%% either be empty or begin with a slash ("/") character. When
%% authority is not present, the path cannot begin with two slash
%% characters ("//"). These restrictions result in five different ABNF
%% rules for a path (Section 3.3), only one of which will match any
%% given URI reference.
%%
%% The following are two example URIs and their component parts:
%%
%% foo://example.com:8042/over/there?name=ferret#nose
%% \_/ \______________/\_________/ \_________/ \__/
%% | | | | |
%% scheme authority path query fragment
%% | _____________________|__
%% / \ / \
%% urn:example:animal:ferret:nose
%%
%% scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
%% authority = [ userinfo "@" ] host [ ":" port ]
%% userinfo = *( unreserved / pct-encoded / sub-delims / ":" )
%%
%%
-module(http_uri).
-export([parse/1, parse/2,
scheme_defaults/0,
encode/1, decode/1]).
-export_type([scheme/0, default_scheme_port_number/0]).
%%%=========================================================================
%%% API
%%%=========================================================================
-type scheme() :: atom().
-type default_scheme_port_number() :: pos_integer().
-spec scheme_defaults() ->
[{scheme(), default_scheme_port_number()}].
scheme_defaults() ->
[{http, 80},
{https, 443},
{ftp, 21},
{ssh, 22},
{sftp, 22},
{tftp, 69}].
parse(AbsURI) ->
parse(AbsURI, []).
parse(AbsURI, Opts) ->
case parse_scheme(AbsURI, Opts) of
{error, Reason} ->
{error, Reason};
{Scheme, DefaultPort, Rest} ->
case (catch parse_uri_rest(Scheme, DefaultPort, Rest, Opts)) of
{ok, Result} ->
{ok, Result};
{error, Reason} ->
{error, {Reason, Scheme, AbsURI}};
_ ->
{error, {malformed_url, Scheme, AbsURI}}
end
end.
reserved() ->
sets:from_list([$;, $:, $@, $&, $=, $+, $,, $/, $?,
$#, $[, $], $<, $>, $\", ${, $}, $|,
$\\, $', $^, $%, $ ]).
encode(URI) ->
Reserved = reserved(),
lists:append([uri_encode(Char, Reserved) || Char <- URI]).
decode(String) ->
do_decode(String).
do_decode([$%,Hex1,Hex2|Rest]) ->
[hex2dec(Hex1)*16+hex2dec(Hex2)|do_decode(Rest)];
do_decode([First|Rest]) ->
[First|do_decode(Rest)];
do_decode([]) ->
[].
%%%========================================================================
%%% Internal functions
%%%========================================================================
which_scheme_defaults(Opts) ->
Key = scheme_defaults,
case lists:keysearch(Key, 1, Opts) of
{value, {Key, SchemeDefaults}} ->
SchemeDefaults;
false ->
scheme_defaults()
end.
parse_scheme(AbsURI, Opts) ->
case split_uri(AbsURI, ":", {error, no_scheme}, 1, 1) of
{error, no_scheme} ->
{error, no_scheme};
{SchemeStr, Rest} ->
Scheme = list_to_atom(http_util:to_lower(SchemeStr)),
SchemeDefaults = which_scheme_defaults(Opts),
case lists:keysearch(Scheme, 1, SchemeDefaults) of
{value, {Scheme, DefaultPort}} ->
{Scheme, DefaultPort, Rest};
false ->
{Scheme, no_default_port, Rest}
end
end.
parse_uri_rest(Scheme, DefaultPort, "//" ++ URIPart, Opts) ->
{Authority, PathQueryFragment} =
split_uri(URIPart, "[/?#]", {URIPart, ""}, 1, 0),
{RawPath, QueryFragment} =
split_uri(PathQueryFragment, "[?#]", {PathQueryFragment, ""}, 1, 0),
{Query, Fragment} =
split_uri(QueryFragment, "#", {QueryFragment, ""}, 1, 0),
{UserInfo, HostPort} = split_uri(Authority, "@", {"", Authority}, 1, 1),
{Host, Port} = parse_host_port(Scheme, DefaultPort, HostPort, Opts),
Path = path(RawPath),
case lists:keyfind(fragment, 1, Opts) of
{fragment, true} ->
{ok, {Scheme, UserInfo, Host, Port, Path, Query, Fragment}};
_ ->
{ok, {Scheme, UserInfo, Host, Port, Path, Query}}
end.
%% In this version of the function, we no longer need
%% the Scheme argument, but just in case...
parse_host_port(_Scheme, DefaultPort, "[" ++ HostPort, Opts) -> %ipv6
{Host, ColonPort} = split_uri(HostPort, "\\]", {HostPort, ""}, 1, 1),
Host2 = maybe_ipv6_host_with_brackets(Host, Opts),
{_, Port} = split_uri(ColonPort, ":", {"", DefaultPort}, 0, 1),
{Host2, int_port(Port)};
parse_host_port(_Scheme, DefaultPort, HostPort, _Opts) ->
{Host, Port} = split_uri(HostPort, ":", {HostPort, DefaultPort}, 1, 1),
{Host, int_port(Port)}.
split_uri(UriPart, SplitChar, NoMatchResult, SkipLeft, SkipRight) ->
case inets_regexp:first_match(UriPart, SplitChar) of
{match, Match, _} ->
{string:substr(UriPart, 1, Match - SkipLeft),
string:substr(UriPart, Match + SkipRight, length(UriPart))};
nomatch ->
NoMatchResult
end.
maybe_ipv6_host_with_brackets(Host, Opts) ->
case lists:keysearch(ipv6_host_with_brackets, 1, Opts) of
{value, {ipv6_host_with_brackets, true}} ->
"[" ++ Host ++ "]";
_ ->
Host
end.
int_port(Port) when is_integer(Port) ->
Port;
int_port(Port) when is_list(Port) ->
list_to_integer(Port);
%% This is the case where no port was found and there was no default port
int_port(no_default_port) ->
throw({error, no_default_port}).
path("") ->
"/";
path(Path) ->
Path.
uri_encode(Char, Reserved) ->
case sets:is_element(Char, Reserved) of
true ->
[ $% | http_util:integer_to_hexlist(Char)];
false ->
[Char]
end.
hex2dec(X) when (X>=$0) andalso (X=<$9) -> X-$0;
hex2dec(X) when (X>=$A) andalso (X=<$F) -> X-$A+10;
hex2dec(X) when (X>=$a) andalso (X=<$f) -> X-$a+10.
