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Diffstat (limited to 'lib/ftp/src/ftp_response.erl')
| -rw-r--r-- | lib/ftp/src/ftp_response.erl | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/lib/ftp/src/ftp_response.erl b/lib/ftp/src/ftp_response.erl new file mode 100644 index 0000000000..8d00153ba8 --- /dev/null +++ b/lib/ftp/src/ftp_response.erl @@ -0,0 +1,203 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2005-2018. All Rights Reserved. +%% +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at +%% +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. +%% +%% %CopyrightEnd% +%% +%% +%% Description: This module impements handling of ftp server responses. + +-module(ftp_response). + +%% Internal API +-export([parse_lines/3, interpret/1, error_string/1]). + +-include("ftp_internal.hrl"). + +%% First group of reply code digits +-define(POS_PREL, 1). +-define(POS_COMPL, 2). +-define(POS_INTERM, 3). +-define(TRANS_NEG_COMPL, 4). +-define(PERM_NEG_COMPL, 5). +%% Second group of reply code digits +-define(SYNTAX,0). +-define(INFORMATION,1). +-define(CONNECTION,2). +-define(AUTH_ACC,3). +-define(UNSPEC,4). +-define(FILE_SYSTEM,5). + +%%%========================================================================= +%%% INTERNAL API +%%%========================================================================= + +%%-------------------------------------------------------------------------- +%% parse_lines(Data, AccLines, StatusCode) -> {ok, Lines} | +%% {continue, {Data, +%% AccLines, StatusCode}} +%% +%% Data = binary() - data recived on the control connection from the +%% ftp-server. +%% AccLines = [string()] +%% StatusCode = start | {byte(), byte(), byte()} | finish - +%% Indicates where in the parsing process we are. +%% start - (looking for the status code of the message) +%% {byte(), byte(), byte()} - status code found, now +%% looking for the last line indication. +%% finish - now on the last line. +%% Description: Parses a ftp control response message. +%% "A reply is defined to contain the 3-digit code, followed by Space +%% <SP>, followed by one line of text (where some maximum line length +%% has been specified), and terminated by the Telnet end-of-line +%% code (CRLF), or a so called multilined reply for example: +%% +%% 123-First line +%% Second line +%% 234 A line beginning with numbers +%% 123 The last line +%% +%% The user-process then simply needs to search for the second +%% occurrence of the same reply code, followed by <SP> (Space), at +%% the beginning of a line, and ignore all intermediary lines. If +%% an intermediary line begins with a 3-digit number, the Server +%% will pad the front to avoid confusion. +%%-------------------------------------------------------------------------- + +%% Make sure we received the first 4 bytes so we know how to parse +%% the FTP server response e.i. is the response composed of one +%% or multiple lines. +parse_lines(Bin, Lines, start) when size(Bin) < 4 -> + {continue, {Bin, Lines, start}}; +%% Multiple lines exist +parse_lines(<<C1, C2, C3, $-, Rest/binary>>, Lines, start) -> + parse_lines(Rest, [$-, C3, C2, C1 | Lines], {C1, C2, C3}); +%% Only one line exists +parse_lines(<<C1, C2, C3, ?WHITE_SPACE, Bin/binary>>, Lines, start) -> + parse_lines(Bin, [?WHITE_SPACE, C3, C2, C1 | Lines], finish); + +%% Last line found +parse_lines(<<?CR, ?LF, C1, C2, C3, ?WHITE_SPACE, Rest/binary>>, Lines, {C1, C2, C3}) -> + parse_lines(Rest, [?WHITE_SPACE, C3, C2, C1, ?LF, ?CR | Lines], finish); +%% Potential end found wait for more data +parse_lines(<<?CR, ?LF, C1, C2, C3>> = Bin, Lines, {C1, C2, C3}) -> + {continue, {Bin, Lines, {C1, C2, C3}}}; +%% Intermidate line begining with status code +parse_lines(<<?CR, ?LF, C1, C2, C3, Rest/binary>>, Lines, {C1, C2, C3}) -> + parse_lines(Rest, [C3, C2, C1, ?LF, ?CR | Lines], {C1, C2, C3}); + +%% Potential last line wait for more data +parse_lines(<<?CR, ?LF, C1, C2>> = Data, Lines, {C1, C2, _} = StatusCode) -> + {continue, {Data, Lines, StatusCode}}; +parse_lines(<<?CR, ?LF, C1>> = Data, Lines, {C1, _, _} = StatusCode) -> + {continue, {Data, Lines, StatusCode}}; +parse_lines(<<?CR, ?LF>> = Data, Lines, {_,_,_} = StatusCode) -> + {continue, {Data, Lines, StatusCode}}; +parse_lines(<<?LF>> = Data, Lines, {_,_,_} = StatusCode) -> + {continue, {Data, Lines, StatusCode}}; +parse_lines(<<>> = Data, Lines, {_,_,_} = StatusCode) -> + {continue, {Data, Lines, StatusCode}}; +%% Part of the multiple lines +parse_lines(<<Octet, Rest/binary>>, Lines, {_,_, _} = StatusCode) -> + parse_lines(Rest, [Octet | Lines], StatusCode); + +%% End of FTP server response found +parse_lines(<<?CR, ?LF>>, Lines, finish) -> + {ok, lists:reverse([?LF, ?CR | Lines]), <<>>}; +parse_lines(<<?CR, ?LF, Rest/binary>>, Lines, finish) -> + {ok, lists:reverse([?LF, ?CR | Lines]), Rest}; + +%% Potential end found wait for more data +parse_lines(<<?CR>> = Data, Lines, finish) -> + {continue, {Data, Lines, finish}}; +parse_lines(<<>> = Data, Lines, finish) -> + {continue, {Data, Lines, finish}}; +%% Part of last line +parse_lines(<<Octet, Rest/binary>>, Lines, finish) -> + parse_lines(Rest, [Octet | Lines], finish). + +%%-------------------------------------------------------------------------- +%% interpret(Lines) -> {Status, Text} +%% Lines = [byte(), byte(), byte() | Text] - ftp server response as +%% returned by parse_lines/3 +%% Stauts = atom() (see interpret_status/3) +%% Text = [string()] +%% +%% Description: Create nicer data to match on. +%%-------------------------------------------------------------------------- +interpret([Didgit1, Didgit2, Didgit3 | Data]) -> + Code1 = Didgit1 - $0, + Code2 = Didgit2 - $0, + Code3 = Didgit3 - $0, + {interpret_status(Code1, Code2, Code3), Data}. + +%%-------------------------------------------------------------------------- +%% error_string(Error) -> string() +%% Error = {error, term()} | term() +%% +%% Description: Translates error codes into strings intended for +%% human interpretation. +%%-------------------------------------------------------------------------- +error_string({error, Reason}) -> + error_string(Reason); + +error_string(echunk) -> "Synchronisation error during chunk sending."; +error_string(eclosed) -> "Session has been closed."; +error_string(econn) -> "Connection to remote server prematurely closed."; +error_string(eexists) ->"File or directory already exists."; +error_string(ehost) -> "Host not found, FTP server not found, " + "or connection rejected."; +error_string(elogin) -> "User not logged in."; +error_string(enotbinary) -> "Term is not a binary."; +error_string(epath) -> "No such file or directory, already exists, " + "or permission denied."; +error_string(etype) -> "No such type."; +error_string(euser) -> "User name or password not valid."; +error_string(etnospc) -> "Insufficient storage space in system."; +error_string(enofile) -> "No files found or file unavailable"; +error_string(epnospc) -> "Exceeded storage allocation " + "(for current directory or dataset)."; +error_string(efnamena) -> "File name not allowed."; +error_string(Reason) -> + lists:flatten(io_lib:format("Unknown error: ~w", [Reason])). + +%%%======================================================================== +%%% Internal functions +%%%======================================================================== + +%% Positive Preleminary Reply +interpret_status(?POS_PREL,_,_) -> pos_prel; +%%FIXME ??? 3??? interpret_status(?POS_COMPL, ?AUTH_ACC, 3) -> tls_upgrade; +interpret_status(?POS_COMPL, ?AUTH_ACC, 4) -> tls_upgrade; +%% Positive Completion Reply +interpret_status(?POS_COMPL,_,_) -> pos_compl; +%% Positive Intermediate Reply nedd account +interpret_status(?POS_INTERM,?AUTH_ACC,2) -> pos_interm_acct; +%% Positive Intermediate Reply +interpret_status(?POS_INTERM,_,_) -> pos_interm; +%% No files found or file not available +interpret_status(?TRANS_NEG_COMPL,?FILE_SYSTEM,0) -> enofile; +%% No storage area no action taken +interpret_status(?TRANS_NEG_COMPL,?FILE_SYSTEM,2) -> etnospc; +%% Temporary Error, no action taken +interpret_status(?TRANS_NEG_COMPL,_,_) -> trans_neg_compl; +%% Permanent disk space error, the user shall not try again +interpret_status(?PERM_NEG_COMPL,?FILE_SYSTEM,0) -> epath; +interpret_status(?PERM_NEG_COMPL,?FILE_SYSTEM,2) -> epnospc; +interpret_status(?PERM_NEG_COMPL,?FILE_SYSTEM,3) -> efnamena; +interpret_status(?PERM_NEG_COMPL,?AUTH_ACC,0) -> elogin; +interpret_status(?PERM_NEG_COMPL,_,_) -> perm_neg_compl. + |