From aaa7c91756da6eb4435c9a23f4725dcc1dc147aa Mon Sep 17 00:00:00 2001 From: Daniel White Date: Sat, 17 Jan 2015 19:20:41 +1100 Subject: Prevent zip:zip_open/1,2 from leaking ports The case was discovered where a parent process would exit before closing the zip file. The result was that a port would be left open indefinitely, as the small zip server would not detect this condition. By comparison, the file module will close the associated port when the parent exits for any reason. This change would make the zip module more consistent with the semantics of similar modules. This change is breaking for any callers expecting to pass the handle to another process for processing (assuming it exits). --- lib/stdlib/src/zip.erl | 26 +++++++++++++++++--------- lib/stdlib/test/zip_SUITE.erl | 42 ++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 57 insertions(+), 11 deletions(-) diff --git a/lib/stdlib/src/zip.erl b/lib/stdlib/src/zip.erl index b768c6d0b9..cbd326ae92 100644 --- a/lib/stdlib/src/zip.erl +++ b/lib/stdlib/src/zip.erl @@ -1114,15 +1114,19 @@ local_file_header_from_info_method_name(#file_info{mtime = MTime}, file_name_length = length(Name), extra_field_length = 0}. +server_init(Parent) -> + %% we want to know if our parent dies + process_flag(trap_exit, true), + server_loop(Parent, not_open). %% small, simple, stupid zip-archive server -server_loop(OpenZip) -> +server_loop(Parent, OpenZip) -> receive {From, {open, Archive, Options}} -> case openzip_open(Archive, Options) of {ok, NewOpenZip} -> From ! {self(), {ok, self()}}, - server_loop(NewOpenZip); + server_loop(Parent, NewOpenZip); Error -> From ! {self(), Error} end; @@ -1130,19 +1134,22 @@ server_loop(OpenZip) -> From ! {self(), openzip_close(OpenZip)}; {From, get} -> From ! {self(), openzip_get(OpenZip)}, - server_loop(OpenZip); + server_loop(Parent, OpenZip); {From, {get, FileName}} -> From ! {self(), openzip_get(FileName, OpenZip)}, - server_loop(OpenZip); + server_loop(Parent, OpenZip); {From, list_dir} -> From ! {self(), openzip_list_dir(OpenZip)}, - server_loop(OpenZip); + server_loop(Parent, OpenZip); {From, {list_dir, Opts}} -> From ! {self(), openzip_list_dir(OpenZip, Opts)}, - server_loop(OpenZip); + server_loop(Parent, OpenZip); {From, get_state} -> From ! {self(), OpenZip}, - server_loop(OpenZip); + server_loop(Parent, OpenZip); + {'EXIT', Parent, Reason} -> + openzip_close(OpenZip), + exit({parent_died, Reason}); _ -> {error, bad_msg} end. @@ -1162,8 +1169,9 @@ zip_open(Archive) -> zip_open(Archive, []). Reason :: term()). zip_open(Archive, Options) -> - Pid = spawn(fun() -> server_loop(not_open) end), - request(self(), Pid, {open, Archive, Options}). + Self = self(), + Pid = spawn_link(fun() -> server_init(Self) end), + request(Self, Pid, {open, Archive, Options}). -spec(zip_get(ZipHandle) -> {ok, [Result]} | {error, Reason} when ZipHandle :: pid(), diff --git a/lib/stdlib/test/zip_SUITE.erl b/lib/stdlib/test/zip_SUITE.erl index a57641ef62..d168a9d9bc 100644 --- a/lib/stdlib/test/zip_SUITE.erl +++ b/lib/stdlib/test/zip_SUITE.erl @@ -23,7 +23,7 @@ bad_zip/1, unzip_from_binary/1, unzip_to_binary/1, zip_to_binary/1, unzip_options/1, zip_options/1, list_dir_options/1, aliases/1, - openzip_api/1, zip_api/1, unzip_jar/1, + openzip_api/1, zip_api/1, open_leak/1, unzip_jar/1, compress_control/1, foldl/1]). @@ -38,7 +38,7 @@ all() -> [borderline, atomic, bad_zip, unzip_from_binary, unzip_to_binary, zip_to_binary, unzip_options, zip_options, list_dir_options, aliases, openzip_api, - zip_api, unzip_jar, compress_control, foldl]. + zip_api, open_leak, unzip_jar, compress_control, foldl]. groups() -> []. @@ -318,8 +318,46 @@ zip_api(Config) when is_list(Config) -> %% Clean up. delete_files([Names]), + ok. + +open_leak(doc) -> + ["Test that zip doesn't leak processes and ports where the " + "controlling process dies without closing an zip opened with " + "zip:zip_open/1."]; +open_leak(suite) -> []; +open_leak(Config) when is_list(Config) -> + %% Create a zip archive + Zip = "zip.zip", + {ok, Zip} = zip:zip(Zip, [], []), + + %% Open archive in a another process that dies immediately. + ZipSrv = spawn_zip(Zip, [memory]), + + %% Expect the ZipSrv process to die soon after. + true = spawned_zip_dead(ZipSrv), + + %% Clean up. + delete_files([Zip]), + ok. +spawn_zip(Zip, Options) -> + Self = self(), + spawn(fun() -> Self ! zip:zip_open(Zip, Options) end), + receive + {ok, ZipSrv} -> + ZipSrv + end. + +spawned_zip_dead(ZipSrv) -> + Ref = monitor(process, ZipSrv), + receive + {'DOWN', Ref, _, ZipSrv, _} -> + true + after 1000 -> + false + end. + unzip_options(doc) -> ["Test options for unzip, only cwd and file_list currently"]; unzip_options(suite) -> -- cgit v1.2.3 From 7b37b460dfb4818941e749030bad33971411a22d Mon Sep 17 00:00:00 2001 From: Daniel White Date: Tue, 17 Feb 2015 14:12:23 +1100 Subject: Document the termination semantics of a zip handle --- lib/stdlib/doc/src/zip.xml | 2 ++ 1 file changed, 2 insertions(+) diff --git a/lib/stdlib/doc/src/zip.xml b/lib/stdlib/doc/src/zip.xml index 48b376743d..3845ccd09d 100644 --- a/lib/stdlib/doc/src/zip.xml +++ b/lib/stdlib/doc/src/zip.xml @@ -430,6 +430,8 @@ means that subsequently reading files from the archive will be faster than unzipping files one at a time with unzip.

The archive must be closed with zip_close/1.

+

The ZipHandle will be closed if the + process which originally opened the archive dies.

-- cgit v1.2.3 From 3ec48aa1782af3b4d84d9bad8129127c2b9f4b9d Mon Sep 17 00:00:00 2001 From: Daniel White Date: Fri, 27 Feb 2015 15:13:42 +1100 Subject: Describe zip handles an opaque type These are not intended to be treated as processes by consumers, and the type specs for the related functions have been updated accordingly. --- lib/stdlib/src/zip.erl | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/lib/stdlib/src/zip.erl b/lib/stdlib/src/zip.erl index cbd326ae92..44e75ff15b 100644 --- a/lib/stdlib/src/zip.erl +++ b/lib/stdlib/src/zip.erl @@ -214,7 +214,9 @@ -type zip_comment() :: #zip_comment{}. -type zip_file() :: #zip_file{}. --export_type([create_option/0, filename/0]). +-opaque handle() :: pid(). + +-export_type([create_option/0, filename/0, handle/0]). %% Open a zip archive with options %% @@ -500,7 +502,7 @@ do_list_dir(F, Options) -> -spec(t(Archive) -> ok when Archive :: file:name() | binary() | ZipHandle, - ZipHandle :: pid()). + ZipHandle :: handle()). t(F) when is_pid(F) -> zip_t(F); t(F) when is_record(F, openzip) -> openzip_t(F); @@ -524,7 +526,7 @@ do_t(F, RawPrint) -> -spec(tt(Archive) -> ok when Archive :: file:name() | binary() | ZipHandle, - ZipHandle :: pid()). + ZipHandle :: handle()). tt(F) when is_pid(F) -> zip_tt(F); tt(F) when is_record(F, openzip) -> openzip_tt(F); @@ -1156,14 +1158,14 @@ server_loop(Parent, OpenZip) -> -spec(zip_open(Archive) -> {ok, ZipHandle} | {error, Reason} when Archive :: file:name() | binary(), - ZipHandle :: pid(), + ZipHandle :: handle(), Reason :: term()). zip_open(Archive) -> zip_open(Archive, []). -spec(zip_open(Archive, Options) -> {ok, ZipHandle} | {error, Reason} when Archive :: file:name() | binary(), - ZipHandle :: pid(), + ZipHandle :: handle(), Options :: [Option], Option :: cooked | memory | {cwd, CWD :: file:filename()}, Reason :: term()). @@ -1174,7 +1176,7 @@ zip_open(Archive, Options) -> request(Self, Pid, {open, Archive, Options}). -spec(zip_get(ZipHandle) -> {ok, [Result]} | {error, Reason} when - ZipHandle :: pid(), + ZipHandle :: handle(), Result :: file:name() | {file:name(), binary()}, Reason :: term()). @@ -1182,14 +1184,14 @@ zip_get(Pid) when is_pid(Pid) -> request(self(), Pid, get). -spec(zip_close(ZipHandle) -> ok | {error, einval} when - ZipHandle :: pid()). + ZipHandle :: handle()). zip_close(Pid) when is_pid(Pid) -> request(self(), Pid, close). -spec(zip_get(FileName, ZipHandle) -> {ok, Result} | {error, Reason} when FileName :: file:name(), - ZipHandle :: pid(), + ZipHandle :: handle(), Result :: file:name() | {file:name(), binary()}, Reason :: term()). @@ -1198,7 +1200,7 @@ zip_get(FileName, Pid) when is_pid(Pid) -> -spec(zip_list_dir(ZipHandle) -> {ok, Result} | {error, Reason} when Result :: [zip_comment() | zip_file()], - ZipHandle :: pid(), + ZipHandle :: handle(), Reason :: term()). zip_list_dir(Pid) when is_pid(Pid) -> -- cgit v1.2.3