aboutsummaryrefslogtreecommitdiffstats
path: root/lib/tftp/src/tftp_file.erl
blob: 43b588f71a7e4c04a31d17650f8e5c6637a99009 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
%%
%% %CopyrightBegin%
%% 
%% Copyright Ericsson AB 2005-2016. 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%
%%
%%

%%%-------------------------------------------------------------------
%%% File    : tft_file.erl
%%% Author  : Hakan Mattsson <[email protected]>
%%% Description : 
%%%
%%% Created : 24 May 2004 by Hakan Mattsson <[email protected]>
%%%-------------------------------------------------------------------

-module(tftp_file).

%%%-------------------------------------------------------------------
%%% Interface
%%%-------------------------------------------------------------------

-behaviour(tftp).

-export([prepare/6, open/6, read/1, write/2, abort/3]).

%%%-------------------------------------------------------------------
%%% Defines
%%%-------------------------------------------------------------------

-include_lib("kernel/include/file.hrl").

-record(initial,
	{filename,
	 is_native_ascii}).

-record(state,
	{access,
	 filename,
	 is_native_ascii,
	 is_network_ascii,
	 root_dir,
	 options,
	 blksize,
	 fd,
	 count,
	 buffer}).

%%-------------------------------------------------------------------
%% prepare(Peer, Access, Filename, Mode, SuggestedOptions, InitialState) -> 
%%    {ok, AcceptedOptions, NewState} | {error, Code, Text}
%%
%% Peer             = {PeerType, PeerHost, PeerPort}
%% PeerType         = inet | inet6
%% PeerHost         = ip_address()
%% PeerPort         = integer()
%% Acess            = read | write
%% Filename         = string()
%% Mode             = string()
%% SuggestedOptions = [{Key, Value}]
%% AcceptedOptions  = [{Key, Value}]
%% Key              = string()
%% Value            = string()
%% InitialState     = [] | [{root_dir, string()}]
%% NewState         = term()
%% Code             = undef | enoent | eacces | enospc |
%%                    badop | eexist | baduser | badopt |
%%                    integer()
%% Text             = string()
%%
%% Prepares open of a file on the client side.
%% 
%% Will be followed by a call to open/4 before any read/write access
%% is performed. The AcceptedOptions will be sent to the server which
%% will reply with those options that it accepts. The options that are
%% accepted by the server will be forwarded to open/4 as SuggestedOptions.
%%
%% No new options may be added, but the ones that are present as
%% SuggestedOptions may be omitted or replaced with new values
%% in the AcceptedOptions.
%%-------------------------------------------------------------------

prepare(_Peer, Access, Filename, Mode, SuggestedOptions, Initial) when is_list(Initial) ->
    %% Client side
    case catch handle_options(Access, Filename, Mode, SuggestedOptions, Initial) of
	{ok, Filename2, IsNativeAscii, IsNetworkAscii, AcceptedOptions} ->
	    State = #state{access           = Access,
			   filename         = Filename2,
			   is_native_ascii  = IsNativeAscii,
			   is_network_ascii = IsNetworkAscii,
			   options  	    = AcceptedOptions,
			   blksize  	    = lookup_blksize(AcceptedOptions),
			   count    	    = 0,
			   buffer   	   =  []},
	    {ok, AcceptedOptions, State};
	{error, {Code, Text}} ->
	    {error, {Code, Text}}
    end.

%% ---------------------------------------------------------
%% open(Peer, Access, Filename, Mode, SuggestedOptions, State) -> 
%%    {ok, AcceptedOptions, NewState} | {error, Code, Text}
%%
%% Peer             = {PeerType, PeerHost, PeerPort}
%% PeerType         = inet | inet6
%% PeerHost         = ip_address()
%% PeerPort         = integer()
%% Acess            = read | write
%% Filename         = string()
%% Mode             = string()
%% SuggestedOptions = [{Key, Value}]
%% AcceptedOptions  = [{Key, Value}]
%% Key              = string()
%% Value            = string()
%% State            = InitialState | #state{}
%% InitialState     = [] | [{root_dir, string()}]
%% NewState         = term()
%% Code             = undef | enoent | eacces  | enospc |
%%                    badop | eexist | baduser | badopt |
%%                    integer()
%% Text             = string()
%%
%% Opens a file for read or write access.
%% 
%% On the client side where the open/4 call has been preceeded by a
%% call to prepare/4, all options must be accepted or rejected.
%% On the server side, where there are no preceeding prepare/4 call,
%% noo new options may be added, but the ones that are present as
%% SuggestedOptions may be omitted or replaced with new values
%% in the AcceptedOptions.
%%-------------------------------------------------------------------

open(Peer, Access, Filename, Mode, SuggestedOptions, Initial) when is_list(Initial) ->
    %% Server side
    case prepare(Peer, Access, Filename, Mode, SuggestedOptions, Initial) of
	{ok, AcceptedOptions, State} ->
	    open(Peer, Access, Filename, Mode, AcceptedOptions, State);
	{error, {Code, Text}} ->
	    {error, {Code, Text}}
    end;
open(_Peer, Access, Filename, Mode, NegotiatedOptions, State) when is_record(State, state) ->
    %% Both sides
    case catch handle_options(Access, Filename, Mode, NegotiatedOptions, State) of
	{ok, _Filename2, _IsNativeAscii, _IsNetworkAscii, Options} 
	   when Options =:= NegotiatedOptions ->
	    do_open(State);
	{error, {Code, Text}} ->
	    {error, {Code, Text}}
    end;
open(Peer, Access, Filename, Mode, NegotiatedOptions, State) ->
    %% Handle upgrade from old releases. Please, remove this clause in next release.
    State2 = upgrade_state(State),
    open(Peer, Access, Filename, Mode, NegotiatedOptions, State2).

do_open(State) when is_record(State, state) ->
    case file:open(State#state.filename, file_options(State)) of
	{ok, Fd} ->
	    {ok, State#state.options, State#state{fd = Fd}};
	{error, Reason} when is_atom(Reason) ->
	    {error, file_error(Reason)}
    end.
	
file_options(State) ->
    case State#state.access of
	read  -> [read, read_ahead, raw, binary];
	write -> [write, delayed_write, raw, binary]
    end.

file_error(Reason) when is_atom(Reason) ->
    Details = file:format_error(Reason),
    case Reason of
	eexist -> {Reason, Details};
	enoent -> {Reason, Details};
	eacces -> {Reason, Details};
	eperm  -> {eacces, Details};
	enospc -> {Reason, Details};
	_      -> {undef,  Details ++ " (" ++ atom_to_list(Reason) ++ ")"}
    end.

%%-------------------------------------------------------------------
%% read(State) ->
%%   {more, Bin, NewState} | {last, Bin, FileSize} | {error, {Code, Text}}
%%
%% State    = term()
%% NewState = term()
%% Bin      = binary()
%% FileSize = integer()
%% Code     = undef | enoent | eacces  | enospc |
%%            badop | eexist | baduser | badopt |
%%            integer()
%% Text     = string()
%%
%% Reads a chunk from the file
%% 
%% The file is automatically closed when the last chunk is read.
%%-------------------------------------------------------------------

read(#state{access = read} = State) ->
    BlkSize = State#state.blksize,
    case file:read(State#state.fd, BlkSize) of
	{ok, Bin} when is_binary(Bin), size(Bin) =:= BlkSize ->
	    Count = State#state.count + size(Bin),
	    {more, Bin, State#state{count = Count}};
	{ok, Bin} when is_binary(Bin), size(Bin) < BlkSize ->
	    _ = file:close(State#state.fd),
	    Count = State#state.count + size(Bin),
	    {last, Bin, Count};
	eof ->
	    {last, <<>>, State#state.count};
	{error, Reason} ->
	    _ = file:close(State#state.fd),
	    {error, file_error(Reason)}
    end;
read(State) ->
    %% Handle upgrade from old releases. Please, remove this clause in next release.
    State2 = upgrade_state(State),
    read(State2).

%%-------------------------------------------------------------------
%% write(Bin, State) ->
%%   {more, NewState} | {last, FileSize} | {error, {Code, Text}}
%%
%% State    = term()
%% NewState = term()
%% Bin      = binary()
%% FileSize = integer()
%% Code     = undef | enoent | eacces  | enospc |
%%            badop | eexist | baduser | badopt |
%%            integer()
%% Text     = string()
%%
%% Writes a chunk to the file
%%
%% The file is automatically closed when the last chunk is written
%%-------------------------------------------------------------------

write(Bin, #state{access = write} = State) when is_binary(Bin) ->
    Size = size(Bin),
    BlkSize = State#state.blksize,
    case file:write(State#state.fd, Bin) of
	ok when Size =:= BlkSize->
	    Count = State#state.count + Size,
	    {more, State#state{count = Count}};
	ok when Size < BlkSize->
	    _ = file:close(State#state.fd),
	    Count = State#state.count + Size,
	    {last, Count};
	{error, Reason}  ->
	    _ = file:close(State#state.fd),
	    _ = file:delete(State#state.filename),
	    {error, file_error(Reason)}
    end;
write(Bin, State) ->
    %% Handle upgrade from old releases. Please, remove this clause in next release.
    State2 = upgrade_state(State),
    write(Bin, State2).

%%-------------------------------------------------------------------
%% abort(Code, Text, State) -> ok
%% 
%% State    = term()
%% Code     = undef  | enoent | eacces  | enospc |
%%            badop  | eexist | baduser | badopt |
%%            badblk | integer()
%% Text     = string()
%%
%% Aborts the file transfer
%%-------------------------------------------------------------------

abort(_Code, _Text, #state{fd = Fd, access = Access} = State) ->
    _ = file:close(Fd),
    case Access of
	write ->
	    ok = file:delete(State#state.filename);
	read ->
	    ok
    end.

%%-------------------------------------------------------------------
%% Process options
%%-------------------------------------------------------------------

handle_options(Access, Filename, Mode, Options, Initial) ->
    I = #initial{filename = Filename, is_native_ascii = is_native_ascii()},
    {Filename2, IsNativeAscii} = handle_initial(Initial, I),
    IsNetworkAscii = handle_mode(Mode, IsNativeAscii),
    Options2 = do_handle_options(Access, Filename2, Options),
    {ok, Filename2, IsNativeAscii, IsNetworkAscii, Options2}.

handle_mode(Mode, IsNativeAscii) ->
    case Mode of
	"netascii" when IsNativeAscii =:= true -> true;
	"octet" -> false;
	_ -> throw({error, {badop, "Illegal mode " ++ Mode}})
    end.

handle_initial([{root_dir, Dir} | Initial], I) ->
    case catch filename_join(Dir, I#initial.filename) of
	{'EXIT', _} ->
	    throw({error, {badop, "Internal error. root_dir is not a string"}});
	Filename2 ->
	    handle_initial(Initial, I#initial{filename = Filename2})
    end;
handle_initial([{native_ascii, Bool} | Initial], I) ->
    case Bool of
	true  -> handle_initial(Initial, I#initial{is_native_ascii = true});
	false -> handle_initial(Initial, I#initial{is_native_ascii = false})
    end;
handle_initial([], I) when is_record(I, initial) ->
    {I#initial.filename, I#initial.is_native_ascii};
handle_initial(State, _) when is_record(State, state) ->
    {State#state.filename, State#state.is_native_ascii}.

filename_join(Dir, Filename) ->
    case filename:pathtype(Filename) of
	absolute ->
	    [_ | RelFilename] = filename:split(Filename),
	    filename:join([Dir, RelFilename]);
	_ ->
	    filename:join([Dir, Filename])
    end.

do_handle_options(Access, Filename, [{Key, Val} | T]) ->
    case Key of
	"tsize" ->
	    case Access of
		read when Val =:= "0" ->
		    case file:read_file_info(Filename) of
			{ok, FI} ->
			    Tsize = integer_to_list(FI#file_info.size),
			    [{Key, Tsize} | do_handle_options(Access, Filename, T)];
			{error, _} ->
			    do_handle_options(Access, Filename, T)
		    end;
		_ ->
		    handle_integer(Access, Filename, Key, Val, T, 0, infinity)
	    end;
	"blksize" ->
	    handle_integer(Access, Filename, Key, Val, T, 8, 65464);
	"timeout" ->
	    handle_integer(Access, Filename, Key, Val, T, 1, 255);
	_ ->
	    do_handle_options(Access, Filename, T)
    end;
do_handle_options(_Access, _Filename, []) ->
    [].


handle_integer(Access, Filename, Key, Val, Options, Min, Max) ->
    case catch list_to_integer(Val) of
	{'EXIT', _} ->
	    do_handle_options(Access, Filename, Options);
	Int when Int >= Min, Int =< Max ->
	    [{Key, Val} | do_handle_options(Access, Filename, Options)];
	Int when Int >= Min, Max =:= infinity ->
	    [{Key, Val} | do_handle_options(Access, Filename, Options)];
	_Int ->
	    throw({error, {badopt, "Illegal " ++ Key ++ " value " ++ Val}})
    end.

lookup_blksize(Options) ->
    case lists:keysearch("blksize", 1, Options) of
	{value, {_, Val}} ->
	    list_to_integer(Val);
	false ->
	    512
    end.

is_native_ascii() ->
    case os:type() of
	{win32, _} -> true;
	_          -> false
    end.

%% Handle upgrade from old releases. Please, remove this function in next release.
upgrade_state({state, Access, Filename, RootDir, Options, BlkSize, Fd, Count, Buffer}) ->
    {state, Access, Filename, false, false, RootDir, Options, BlkSize, Fd, Count, Buffer}.