From de2fb97f15ac98aa1d1c5533aacca378334f4778 Mon Sep 17 00:00:00 2001 From: Anthony Ramine Date: Tue, 1 Jul 2014 00:58:26 +0200 Subject: Fix handling of broken symlinks in filelib This fixes a bug introduced in f11aabdc9fec593c31e6c4f3fa25c1707e9c35df where filelib:eval_read_file_info/2 was made to use file:read_link_info/1 to never follow symlinks. This fixed wildcard/1 but broke every other function using eval_read_file_info/2. Reported-by: Louis-Philippe Gauthier Reported-by: Danil Zagoskin --- erts/doc/src/erl_prim_loader.xml | 16 ++++++++++++++ erts/preloaded/src/erl_prim_loader.erl | 38 ++++++++++++++++++++++++++-------- lib/kernel/src/erl_boot_server.erl | 6 +++++- lib/stdlib/src/filelib.erl | 14 +++++++++++-- lib/stdlib/test/filelib_SUITE.erl | 25 ++++++++++++++++++++-- 5 files changed, 85 insertions(+), 14 deletions(-) diff --git a/erts/doc/src/erl_prim_loader.xml b/erts/doc/src/erl_prim_loader.xml index 6751deda4d..171f84decc 100644 --- a/erts/doc/src/erl_prim_loader.xml +++ b/erts/doc/src/erl_prim_loader.xml @@ -147,6 +147,22 @@ See code(3) about archive files.

+ + + Get information about a link or file + +

This function works like + read_file_info/1 + except that if Filename is a symbolic link, + information about the link will be returned in the file_info + record and the type field of the record will be set to + symlink.

+

If Filename is not a symbolic link, this function + returns exactly the same result as read_file_info/1. + On platforms that do not support symbolic links, this function + is always equivalent to read_file_info/1.

+ + Set the path of the loader diff --git a/erts/preloaded/src/erl_prim_loader.erl b/erts/preloaded/src/erl_prim_loader.erl index 578913b633..466e0b0020 100644 --- a/erts/preloaded/src/erl_prim_loader.erl +++ b/erts/preloaded/src/erl_prim_loader.erl @@ -42,11 +42,11 @@ %% Public -export([start/3, set_path/1, get_path/0, get_file/1, get_files/2, - list_dir/1, read_file_info/1, get_cwd/0, get_cwd/1]). + list_dir/1, read_file_info/1, read_link_info/1, get_cwd/0, get_cwd/1]). %% Used by erl_boot_server -export([prim_init/0, prim_get_file/2, prim_list_dir/2, - prim_read_file_info/2, prim_get_cwd/2]). + prim_read_file_info/3, prim_get_cwd/2]). %% Used by escript and code -export([set_primary_archive/4, release_archives/0]). @@ -223,6 +223,12 @@ list_dir(Dir) -> read_file_info(File) -> check_file_result(read_file_info, File, request({read_file_info,File})). +-spec read_link_info(Filename) -> {'ok', FileInfo} | 'error' when + Filename :: string(), + FileInfo :: file:file_info(). +read_link_info(File) -> + check_file_result(read_link_info, File, request({read_link_info,File})). + -spec get_cwd() -> {'ok', string()} | 'error'. get_cwd() -> check_file_result(get_cwd, [], request({get_cwd,[]})). @@ -325,6 +331,9 @@ loop(State, Parent, Paths) -> {read_file_info,File} -> {Res,State1} = handle_read_file_info(State, File), {Res,State1,Paths}; + {read_link_info,File} -> + {Res,State1} = handle_read_link_info(State, File), + {Res,State1,Paths}; {get_cwd,[]} -> {Res,State1} = handle_get_cwd(State, []), {Res,State1,Paths}; @@ -387,10 +396,15 @@ handle_list_dir(State = #state{loader = inet}, Dir) -> ?SAFE2(inet_list_dir(State, Dir), State). handle_read_file_info(State = #state{loader = efile}, File) -> - ?SAFE2(efile_read_file_info(State, File), State); + ?SAFE2(efile_read_file_info(State, File, true), State); handle_read_file_info(State = #state{loader = inet}, File) -> ?SAFE2(inet_read_file_info(State, File), State). +handle_read_link_info(State = #state{loader = efile}, File) -> + ?SAFE2(efile_read_file_info(State, File, false), State); +handle_read_link_info(State = #state{loader = inet}, File) -> + ?SAFE2(inet_read_link_info(State, File), State). + handle_get_cwd(State = #state{loader = efile}, Drive) -> ?SAFE2(efile_get_cwd(State, Drive), State); handle_get_cwd(State = #state{loader = inet}, Drive) -> @@ -514,8 +528,8 @@ efile_list_dir(#state{prim_state = PS} = State, Dir) -> {Res, PS2} = prim_list_dir(PS, Dir), {Res, State#state{prim_state = PS2}}. -efile_read_file_info(#state{prim_state = PS} = State, File) -> - {Res, PS2} = prim_read_file_info(PS, File), +efile_read_file_info(#state{prim_state = PS} = State, File, FollowLinks) -> + {Res, PS2} = prim_read_file_info(PS, File, FollowLinks), {Res, State#state{prim_state = PS2}}. efile_get_cwd(#state{prim_state = PS} = State, Drive) -> @@ -718,6 +732,10 @@ inet_list_dir(State, Dir) -> inet_read_file_info(State, File) -> inet_send_and_rcv({read_file_info,File}, read_file_info, State). +%% -> {{ok,Info},State} | {{error,Reason},State} +inet_read_link_info(State, File) -> + inet_send_and_rcv({read_link_info,File}, read_link_info, State). + %% -> {{ok,Cwd},State} | {{error,Reason},State} inet_get_cwd(State, []) -> inet_send_and_rcv(get_cwd, get_cwd, State); @@ -951,16 +969,18 @@ prim_list_dir(PS, Dir) -> debug(PS, {return, Res2}), {Res2, PS3}. --spec prim_read_file_info(prim_state(), file:filename()) -> +-spec prim_read_file_info(prim_state(), file:filename(), boolean()) -> {{'ok', #file_info{}}, prim_state()} | {{'error', term()}, prim_state()}. -prim_read_file_info(PS, File) -> +prim_read_file_info(PS, File, FollowLinks) -> debug(PS, {read_file_info, File}), {Res2, PS2} = case name_split(PS#prim_state.primary_archive, File) of {file, PrimFile} -> - Res = prim_file:read_file_info(PrimFile), - {Res, PS}; + case FollowLinks of + true -> {prim_file:read_file_info(PrimFile), PS}; + false -> {prim_file:read_link_info(PrimFile), PS} + end; {archive, ArchiveFile, []} -> %% Fake top directory debug(PS, {archive_read_file_info, ArchiveFile}), diff --git a/lib/kernel/src/erl_boot_server.erl b/lib/kernel/src/erl_boot_server.erl index 9a49655a9f..ef09d86ca4 100644 --- a/lib/kernel/src/erl_boot_server.erl +++ b/lib/kernel/src/erl_boot_server.erl @@ -341,9 +341,13 @@ handle_command(S, PS, Msg) -> send_file_result(S, list_dir, Res), PS2; {read_file_info,File} -> - {Res, PS2} = erl_prim_loader:prim_read_file_info(PS, File), + {Res, PS2} = erl_prim_loader:prim_read_file_info(PS, File, true), send_file_result(S, read_file_info, Res), PS2; + {read_link_info,File} -> + {Res, PS2} = erl_prim_loader:prim_read_file_info(PS, File, false), + send_file_result(S, read_link_info, Res), + PS2; get_cwd -> {Res, PS2} = erl_prim_loader:prim_get_cwd(PS, []), send_file_result(S, get_cwd, Res), diff --git a/lib/stdlib/src/filelib.erl b/lib/stdlib/src/filelib.erl index c0921e4cf1..9efbe8da20 100644 --- a/lib/stdlib/src/filelib.erl +++ b/lib/stdlib/src/filelib.erl @@ -265,7 +265,7 @@ do_wildcard(Pattern, Cwd, Mod) -> lists:sort(Files). do_wildcard_1({exists,File}, Mod) -> - case eval_read_file_info(File, Mod) of + case eval_read_link_info(File, Mod) of {ok,_} -> [File]; _ -> [] end; @@ -488,7 +488,7 @@ badpattern(Reason) -> error({badpattern,Reason}). eval_read_file_info(File, file) -> - file:read_link_info(File); + file:read_file_info(File); eval_read_file_info(File, erl_prim_loader) -> case erl_prim_loader:read_file_info(File) of error -> {error, erl_prim_loader}; @@ -497,6 +497,16 @@ eval_read_file_info(File, erl_prim_loader) -> eval_read_file_info(File, Mod) -> Mod:read_file_info(File). +eval_read_link_info(File, file) -> + file:read_link_info(File); +eval_read_link_info(File, erl_prim_loader) -> + case erl_prim_loader:read_link_info(File) of + error -> {error, erl_prim_loader}; + Res-> Res + end; +eval_read_link_info(File, Mod) -> + Mod:read_link_info(File). + eval_list_dir(Dir, file) -> file:list_dir(Dir); eval_list_dir(Dir, erl_prim_loader) -> diff --git a/lib/stdlib/test/filelib_SUITE.erl b/lib/stdlib/test/filelib_SUITE.erl index 8203a03a7a..f1a072194a 100644 --- a/lib/stdlib/test/filelib_SUITE.erl +++ b/lib/stdlib/test/filelib_SUITE.erl @@ -23,7 +23,8 @@ init_per_group/2,end_per_group/2, init_per_testcase/2,end_per_testcase/2, wildcard_one/1,wildcard_two/1,wildcard_errors/1, - fold_files/1,otp_5960/1,ensure_dir_eexist/1,symlinks/1]). + fold_files/1,otp_5960/1,ensure_dir_eexist/1,ensure_dir_symlink/1, + symlinks/1]). -import(lists, [foreach/2]). @@ -43,7 +44,7 @@ suite() -> [{ct_hooks,[ts_install_cth]}]. all() -> [wildcard_one, wildcard_two, wildcard_errors, - fold_files, otp_5960, ensure_dir_eexist, symlinks]. + fold_files, otp_5960, ensure_dir_eexist, ensure_dir_symlink, symlinks]. groups() -> []. @@ -367,6 +368,26 @@ ensure_dir_eexist(Config) when is_list(Config) -> ?line {error, eexist} = filelib:ensure_dir(NeedFileB), ok. +ensure_dir_symlink(Config) when is_list(Config) -> + PrivDir = ?config(priv_dir, Config), + Dir = filename:join(PrivDir, "ensure_dir_symlink"), + Name = filename:join(Dir, "same_name_as_file_and_dir"), + ok = filelib:ensure_dir(Name), + ok = file:write_file(Name, <<"some string\n">>), + %% With a symlink to the directory. + Symlink = filename:join(PrivDir, "ensure_dir_symlink_link"), + case file:make_symlink(Dir, Symlink) of + {error,enotsup} -> + {skip,"Symlinks not supported on this platform"}; + {error,eperm} -> + {win32,_} = os:type(), + {skip,"Windows user not privileged to create symlinks"}; + ok -> + SymlinkedName = filename:join(Symlink, "same_name_as_file_and_dir"), + ok = filelib:ensure_dir(SymlinkedName) + end. + + symlinks(Config) when is_list(Config) -> PrivDir = ?config(priv_dir, Config), Dir = filename:join(PrivDir, ?MODULE_STRING++"_symlinks"), -- cgit v1.2.3