inets,tftp: Break out TFTP from inets

- Create directory structure
- Move code, tests, documentation from inets
- Add inets_tftp_wrapper
- Add tftp app to run-dialyzer script

Change-Id: I6a142ae66cecb9a1821cbf9ea6a45f66a836763d

8 files changed, 1556 insertions, 0 deletions

diff --git a/lib/tftp/test/Makefile b/lib/tftp/test/Makefile
new file mode 100644
index 0000000000..99f36256b0
--- /dev/null
+++ b/lib/tftp/test/Makefile
@@ -0,0 +1,250 @@
+#
+# %CopyrightBegin%
+#
+# Copyright Ericsson AB 1997-2018. 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%
+#
+#
+# For an outline of how this all_SUITE_data stuff works, see the
+# make file ../../ssl/test/Makefile.
+#
+include $(ERL_TOP)/make/target.mk
+include $(ERL_TOP)/make/$(TARGET)/otp.mk
+
+# ----------------------------------------------------
+# Application version
+# ----------------------------------------------------
+include ../vsn.mk
+VSN = $(TFTP_VSN)
+
+
+# ----------------------------------------------------
+# Release directory specification
+# ----------------------------------------------------
+RELSYSDIR = $(RELEASE_PATH)/lib/$(APPLICATION)-$(VSN)
+
+
+# ----------------------------------------------------
+# Target Specs
+# ----------------------------------------------------
+INCLUDES = -I. \
+	-I$(ERL_TOP)/lib/tftp/src
+
+CP = cp
+
+ifeq ($(TESTROOT_DIR),)
+TESTROOT_DIR = /ldisk/tests/$(USER)/tftp
+endif
+
+ifeq ($(TFTP_DATA_DIR),)
+TFTP_DATA_DIR = $(TESTROOT_DIR)/data_dir
+endif
+
+ifeq ($(TFTP_PRIV_DIR),)
+TFTP_PRIV_DIR = $(TESTROOT_DIR)/priv_dir
+endif
+
+TFTP_FLAGS = -Dtftp__data_dir='"$(TFTP_DATA_DIR)"'       \
+              -Dtftp_priv_dir='"$(TFTP_PRIV_DIR)"'
+
+
+### 
+### test suite debug flags
+### 
+ifeq ($(TFTP_DEBUG_CLIENT),)
+  TFTP_DEBUG_CLIENT = y
+endif
+
+ifeq ($(TFTP_DEBUG_CLIENT),)
+  TFTP_FLAGS += -Dtftp_debug_client
+endif
+
+ifeq ($(TFTP_TRACE_CLIENT),)
+  TFTP_DEBUG_CLIENT = y
+endif
+
+ifeq ($(TFTP_TRACE_CLIENT),y)
+  TFTP_FLAGS += -Dtftp_trace_client
+endif
+
+ifneq ($(TFTP_DEBUG),)
+  TFTP_DEBUG = s
+endif
+
+ifeq ($(TFTP_DEBUG),l)
+  TFTP_FLAGS += -Dtftp_log
+endif
+
+ifeq ($(TFTP_DEBUG),d)
+  TFTP_FLAGS += -Dtftp_debug -Dtftp_log
+endif
+
+
+TFTP_FLAGS += -pa ../tftp/ebin
+
+TFTP_ROOT = ../tftp
+
+MODULES =                 		\
+	tftp_SUITE 	  		\
+	tftp_test_lib
+
+
+EBIN = .
+
+HRL_FILES = \
+	../src/tftp.hrl \
+	tftp_test_lib.hrl
+
+ERL_FILES = $(MODULES:%=%.erl)
+
+SOURCE = $(ERL_FILES) $(HRL_FILES) 
+
+TARGET_FILES = $(MODULES:%=$(EBIN)/%.$(EMULATOR))
+
+TFTP_SPECS = tftp.spec tftp_bench.spec
+COVER_FILE = tftp.cover
+TFTP_FILES = tftp.config $(TFTP_SPECS)
+
+
+TFTP_DATADIRS   = tftp_SUITE_data  
+
+DATADIRS     = $(TFTP_DATADIRS)
+
+EMAKEFILE  = Emakefile
+MAKE_EMAKE = $(wildcard $(ERL_TOP)/make/make_emakefile)
+
+ifeq ($(MAKE_EMAKE),)
+BUILDTARGET   = $(TARGET_FILES)
+RELTEST_FILES = $(COVER_FILE) $(TFTP_SPECS) $(SOURCE)
+else
+BUILDTARGET   = emakebuild
+RELTEST_FILES = $(EMAKEFILE) $(COVER_FILE) $(TFTP_SPECS) $(SOURCE)
+endif
+
+
+# ----------------------------------------------------
+# Release directory specification
+# ----------------------------------------------------
+
+RELTESTSYSDIR        = "$(RELEASE_PATH)/tftp_test"
+RELTESTSYSALLDATADIR = $(RELTESTSYSDIR)/all_SUITE_data
+RELTESTSYSBINDIR     = $(RELTESTSYSALLDATADIR)/bin
+
+
+# ----------------------------------------------------
+# FLAGS
+# The path to the test_server ebin dir is needed when 
+# running the target "targets".
+# ----------------------------------------------------
+ERL_COMPILE_FLAGS += \
+	$(INCLUDES) \
+	$(TFTP_FLAGS)
+
+# ----------------------------------------------------
+# Targets
+# erl -sname kalle -pa ../ebin
+# If you intend to run the test suite locally (private), then
+# there is some requirements:
+# 1) TFTP_PRIV_DIR must be created
+# ----------------------------------------------------
+
+tests debug opt: $(BUILDTARGET) 
+
+targets: $(TARGET_FILES)
+
+.PHONY: emakebuild
+
+emakebuild: $(EMAKEFILE)
+
+$(EMAKEFILE): 
+	$(MAKE_EMAKE) $(ERL_COMPILE_FLAGS) -o$(EBIN) '*_SUITE_make' | grep -v Warning > $(EMAKEFILE)
+	$(MAKE_EMAKE) $(ERL_COMPILE_FLAGS) -o$(EBIN) $(MODULES) | grep -v Warning >> $(EMAKEFILE)
+
+clean:
+	rm -f $(EMAKEFILE)
+	rm -f $(TARGET_FILES)
+	rm -f core *~
+
+docs:
+
+
+# ----------------------------------------------------
+# Release Target
+# ---------------------------------------------------- 
+include $(ERL_TOP)/make/otp_release_targets.mk
+
+release_spec: opt
+	$(INSTALL_DIR)  "$(RELSYSDIR)/test"
+	$(INSTALL_DATA) $(HRL_FILES)   $(ERL_FILES) "$(RELSYSDIR)/test"
+	$(INSTALL_DATA) $(TFTP_FILES) "$(RELSYSDIR)/test"
+	@for d in $(DATADIRS); do \
+            echo "installing data dir $$d"; \
+            if test -f $$d/TAR.exclude; then \
+                echo $$d/TAR.exclude2 > $$d/TAR.exclude2; \
+                cat $$d/TAR.exclude >> $$d/TAR.exclude2; \
+                find $$d -name '*.contrib*'     >> $$d/TAR.exclude2; \
+                find $$d -name '*.keep*'        >> $$d/TAR.exclude2; \
+                find $$d -name '*.mkelem*'      >> $$d/TAR.exclude2; \
+                find $$d -name '*~'             >> $$d/TAR.exclude2; \
+                find $$d -name 'erl_crash.dump' >> $$d/TAR.exclude2; \
+                find $$d -name 'core'           >> $$d/TAR.exclude2; \
+                find $$d -name '.cmake.state'   >> $$d/TAR.exclude2; \
+                tar cfX - $$d/TAR.exclude2 $$d | (cd "$(RELSYSDIR)/test"; tar xf -); \
+            else \
+                tar cf - $$d | (cd "$(RELSYSDIR)/test"; tar xf -); \
+            fi; \
+        done
+
+release_tests_spec: opt
+	$(INSTALL_DIR) $(RELTESTSYSDIR)
+	$(INSTALL_DATA) $(RELTEST_FILES) $(RELTESTSYSDIR)
+	chmod -R u+w $(RELTESTSYSDIR)
+	tar chf - $(DATADIRS) | (cd $(RELTESTSYSDIR); tar xf -)
+	$(INSTALL_DIR) $(RELTESTSYSALLDATADIR)
+	$(INSTALL_DIR) $(RELTESTSYSBINDIR)
+	chmod -R +x $(RELTESTSYSBINDIR)
+	$(INSTALL_DIR) $(RELTESTSYSALLDATADIR)/win32/lib	
+
+release_docs_spec:
+
+info:
+	@echo "MAKE_EMAKE        = $(MAKE_EMAKE)"
+	@echo "EMAKEFILE         = $(EMAKEFILE)"
+	@echo "BUILDTARGET       = $(BUILDTARGET)"
+	@echo ""
+	@echo "MODULES           = $(MODULES)"
+	@echo "ERL_FILES         = $(ERL_FILES)"
+	@echo "SOURCE            = $(SOURCE)"
+	@echo "TARGET_FILES      = $(TARGET_FILES)"
+	@echo ""
+	@echo "TFTP_SPECS       = $(TFTP_SPECS)"
+	@echo "TFTP_FILES       = $(TFTP_FILES)"
+	@echo ""
+	@echo "RELEASE_PATH      = "$(RELEASE_PATH)""
+	@echo "RELSYSDIR         = "$(RELSYSDIR)""
+	@echo "RELTESTSYSDIR     = $(RELTESTSYSDIR)"
+	@echo "RELTESTSYSALLDATADIR = $(RELTESTSYSALLDATADIR)"
+	@echo "RELTESTSYSBINDIR     = $(RELTESTSYSBINDIR)"
+	@echo ""
+	@echo "DATADIRS          = $(DATADIRS)"
+	@echo "REL_DATADIRS      = $(REL_DATADIRS)"
+	@echo ""
+	@echo "TFTP_DATA_DIR    = $(TFTP_DATA_DIR)"
+	@echo "TFTP_PRIV_DIR    = $(TFTP_PRIV_DIR)"
+	@echo "TFTP_ROOT        = $(TFTP_ROOT)"
+	@echo "TFTP_FLAGS       = $(TFTP_FLAGS)"
+
+
diff --git a/lib/tftp/test/tftp.config b/lib/tftp/test/tftp.config
new file mode 100644
index 0000000000..2600237da9
--- /dev/null
+++ b/lib/tftp/test/tftp.config
@@ -0,0 +1 @@
+[].
\ No newline at end of file
diff --git a/lib/tftp/test/tftp.cover b/lib/tftp/test/tftp.cover
new file mode 100644
index 0000000000..22ef5d0dda
--- /dev/null
+++ b/lib/tftp/test/tftp.cover
@@ -0,0 +1,2 @@
+{incl_app,tftp,details}.
+
diff --git a/lib/tftp/test/tftp.spec b/lib/tftp/test/tftp.spec
new file mode 100644
index 0000000000..f3537bc652
--- /dev/null
+++ b/lib/tftp/test/tftp.spec
@@ -0,0 +1 @@
+{suites,"../tftp_test", all}.
diff --git a/lib/tftp/test/tftp_SUITE.erl b/lib/tftp/test/tftp_SUITE.erl
new file mode 100644
index 0000000000..a43fd51153
--- /dev/null
+++ b/lib/tftp/test/tftp_SUITE.erl
@@ -0,0 +1,949 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2006-2016. 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%
+%%
+
+-module(tftp_SUITE).
+
+-compile(export_all).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Includes and defines
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+-include("tftp_test_lib.hrl").
+
+-define(START_DAEMON(Port, Options),
+        begin
+            {ok, Pid} = ?VERIFY({ok, _Pid}, tftp:start([{port, Port} | Options])),
+            if
+                Port == 0 ->
+                    {ok, ActualOptions} = ?IGNORE(tftp:info(Pid)),
+                    {value, {port, ActualPort}} =
+                        lists:keysearch(port, 1, ActualOptions),
+                    {ActualPort, Pid};
+                true ->
+                    {Port, Pid}
+            end
+        end).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% API
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+t() -> 
+    tftp_test_lib:t([{?MODULE, all}]).
+
+t(Cases) ->
+    tftp_test_lib:t(Cases, default_config()).
+
+t(Cases, Config) ->
+    tftp_test_lib:t(Cases, Config).
+
+default_config() ->
+    [].
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Test server callbacks
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+init_per_testcase(Case, Config) ->
+    tftp_test_lib:init_per_testcase(Case, Config).
+
+end_per_testcase(Case, Config) when is_list(Config) ->
+    tftp_test_lib:end_per_testcase(Case, Config).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Top test case
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+suite() -> [{ct_hooks,[ts_install_cth]}].
+
+all() -> 
+    [simple, extra, reuse_connection, resend_client,
+     resend_server, large_file].
+
+groups() -> 
+    [].
+
+init_per_suite(Config) ->
+    Config.
+
+end_per_suite(_Config) ->
+    ok.
+
+init_per_group(_GroupName, Config) ->
+    Config.
+
+end_per_group(_GroupName, Config) ->
+    Config.
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Simple
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+simple(doc) ->
+    ["Start the daemon and perform simple a read and write."];
+simple(suite) ->
+    [];
+simple(Config) when is_list(Config) ->
+    ?VERIFY(ok, application:start(tftp)),
+
+    {Port, DaemonPid} = ?IGNORE(?START_DAEMON(0, [{debug, brief}])),
+
+    %% Read fail
+    RemoteFilename = "tftp_temporary_remote_test_file.txt",
+    LocalFilename = "tftp_temporary_local_test_file.txt",
+    Blob = list_to_binary(lists:duplicate(2000, $1)),
+    %% Blob = <<"Some file contents\n">>,
+    Size = size(Blob),
+    ?IGNORE(file:delete(RemoteFilename)),
+    ?VERIFY({error, {client_open, enoent, _}},
+            tftp:read_file(RemoteFilename, binary, [{port, Port}])),
+    
+    %% Write and read
+    ?VERIFY({ok, Size}, tftp:write_file(RemoteFilename, Blob, [{port, Port}])),
+    ?VERIFY({ok, Blob}, tftp:read_file(RemoteFilename, binary, [{port, Port}])),
+    ?IGNORE(file:delete(LocalFilename)),
+    ?VERIFY({ok, Size}, tftp:read_file(RemoteFilename, LocalFilename, [{port, Port}])),
+
+    %% Cleanup
+    unlink(DaemonPid),
+    exit(DaemonPid, kill),
+    ?VERIFY(ok, file:delete(LocalFilename)),
+    ?VERIFY(ok, file:delete(RemoteFilename)),
+    ?VERIFY(ok, application:stop(tftp)),
+    ok.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Extra
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+extra(doc) ->
+    ["Verify new stuff for IS 1.2."];
+extra(suite) ->
+    [];
+extra(Config) when is_list(Config) ->
+    ?VERIFY({'EXIT', {badarg,{fake_key, fake_flag}}},
+            tftp:start([{port, 0}, {fake_key, fake_flag}])),
+
+    {Port, DaemonPid} = ?IGNORE(?START_DAEMON(0, [{debug, brief}])),
+    
+    RemoteFilename = "tftp_extra_temporary_remote_test_file.txt",
+    LocalFilename = "tftp_extra_temporary_local_test_file.txt",
+    Blob = <<"Some file contents\n">>,
+    Size = size(Blob),
+    Host = "127.0.0.1",
+    Peer = {inet, Host, Port},
+    Generic =
+        [
+         {state,   []},
+         {prepare, fun extra_prepare/6},
+         {open,    fun extra_open/6},
+         {read,    fun extra_read/1},
+         {write,   fun extra_write/2},
+         {abort,   fun extra_abort/3 }
+        ],
+    Options = [{host, Host},
+               {port, Port},
+               %%{ debug,all},
+               {callback, {".*", tftp_test_lib, Generic}}],
+    ?VERIFY(ok, file:write_file(LocalFilename, Blob)),
+    ?VERIFY({ok, [{count, Size}, Peer]},
+            tftp:write_file(RemoteFilename, LocalFilename, Options)),
+    ?VERIFY(ok, file:delete(LocalFilename)),
+    
+    ?VERIFY({ok,[{bin, Blob}, Peer]}, 
+            tftp:read_file(RemoteFilename, LocalFilename, Options)),
+
+    %% Cleanup
+    unlink(DaemonPid),
+    exit(DaemonPid, kill),
+    ?VERIFY(ok, file:delete(LocalFilename)),
+    ?VERIFY(ok, file:delete(RemoteFilename)),
+    ok.
+
+-record(extra_state,  {file, blksize, count, acc, peer}).
+
+%%-------------------------------------------------------------------
+%% Prepare
+%%-------------------------------------------------------------------
+
+extra_prepare(Peer, Access, LocalFilename, Mode, SuggestedOptions, []) ->
+    %% Client side
+    BlkSize = list_to_integer(tftp_test_lib:lookup_option("blksize", "512", SuggestedOptions)),
+    State = #extra_state{blksize = BlkSize, peer = Peer},
+    extra_open(Peer, Access, LocalFilename, Mode, SuggestedOptions, State),
+    {ok, SuggestedOptions, State};
+extra_prepare(_Peer, _Access, _Bin, _Mode, _SuggestedOptions, _Initial) ->
+    {error, {undef, "Illegal callback options."}}.
+
+%%-------------------------------------------------------------------
+%% Open
+%%-------------------------------------------------------------------
+
+extra_open(Peer, Access, LocalFilename, Mode, SuggestedOptions, []) ->
+    %% Server side
+    case extra_prepare(Peer, Access, LocalFilename, Mode, SuggestedOptions, []) of
+        {ok, AcceptedOptions, []} ->
+            BlkSize = list_to_integer(tftp_test_lib:lookup_option("blksize", "512", AcceptedOptions)),
+            State = #extra_state{blksize = BlkSize, peer = Peer},
+            extra_open(Peer, Access, LocalFilename, Mode, AcceptedOptions, State);
+        {error, {Code, Text}} ->
+            {error, {Code, Text}}
+    end;
+extra_open(_Peer, Access, LocalFilename, _Mode, NegotiatedOptions, #extra_state{} = State) ->
+    {File, Acc} =
+        case Access of
+            read ->
+                if
+                    is_binary(LocalFilename) ->
+                        {undefined, LocalFilename};
+                    is_list(LocalFilename) ->
+                        {ok, Bin} = file:read_file(LocalFilename),
+                        {LocalFilename, Bin}
+            end;
+            write -> 
+                {LocalFilename, []}
+        end,
+    %% Both sides
+    State2 = State#extra_state{file = File, acc = Acc, count = 0},
+    {ok, NegotiatedOptions, State2}.
+
+%%-------------------------------------------------------------------
+%% Read
+%%-------------------------------------------------------------------
+
+extra_read(#extra_state{acc = Bin} = State) when is_binary(Bin) ->
+    BlkSize = State#extra_state.blksize,
+    Count = State#extra_state.count + size(Bin),
+    if
+        size(Bin) >= BlkSize ->
+            <<Block:BlkSize/binary, Bin2/binary>> = Bin,
+            State2 = State#extra_state{acc = Bin2, count = Count},
+            {more, Block, State2};
+        size(Bin) < BlkSize ->
+            Res = [{count, Count}, State#extra_state.peer],
+            {last, Bin, Res}
+    end.
+
+%%-------------------------------------------------------------------
+%% Write
+%%-------------------------------------------------------------------
+
+extra_write(Bin, #extra_state{acc = List} = State) when is_binary(Bin), is_list(List) ->
+    Size = size(Bin),
+    BlkSize = State#extra_state.blksize,
+    if
+        Size == BlkSize ->
+            {more, State#extra_state{acc = [Bin | List]}};
+        Size < BlkSize ->
+            Bin2 = list_to_binary(lists:reverse([Bin | List])),
+            Res = [{bin,  Bin2}, State#extra_state.peer],
+            file:write_file(State#extra_state.file, Bin2),
+            {last, Res}
+    end.
+
+%%-------------------------------------------------------------------
+%% Abort
+%%-------------------------------------------------------------------
+
+extra_abort(_Code, _Text, #extra_state{}) ->
+    ok.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Re-send client
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+resend_client(doc) ->
+    ["Verify that the server behaves correctly when the client re-sends packets."];
+resend_client(suite) ->
+    [];
+resend_client(Config) when is_list(Config) ->
+    Host = {127, 0, 0, 1},
+    {Port, DaemonPid} = ?IGNORE(?START_DAEMON(0, [{debug, all}])),
+
+    ?VERIFY(ok, resend_read_client(Host, Port, 10)),
+    ?VERIFY(ok, resend_read_client(Host, Port, 512)),
+    ?VERIFY(ok, resend_read_client(Host, Port, 1025)),
+
+    ?VERIFY(ok, resend_write_client(Host, Port, 10)),
+    ?VERIFY(ok, resend_write_client(Host, Port, 512)),
+    ?VERIFY(ok, resend_write_client(Host, Port, 1025)),
+    
+    %% Cleanup
+    unlink(DaemonPid),
+    exit(DaemonPid, kill),
+    ok.
+
+resend_read_client(Host, Port, BlkSize) ->
+    RemoteFilename = "tftp_resend_read_client.tmp",
+    Block1 = lists:duplicate(BlkSize, $1),
+    Block2 = lists:duplicate(BlkSize, $2),
+    Block3 = lists:duplicate(BlkSize, $3),
+    Block4 = lists:duplicate(BlkSize, $4),
+    Block5 = lists:duplicate(BlkSize, $5),
+    Blocks = [Block1, Block2, Block3, Block4, Block5],
+    Blob = list_to_binary(Blocks),
+    ?VERIFY(ok, file:write_file(RemoteFilename, Blob)),
+
+    Timeout = timer:seconds(3),
+    ?VERIFY(timeout, recv(0)),
+
+    %% Open socket
+    {ok, Socket} = ?VERIFY({ok, _}, gen_udp:open(0, [binary, {reuseaddr, true}, {active, true}])),
+
+    ReadList = [0, 1, RemoteFilename, 0, "octet", 0],
+    Data1Bin = list_to_binary([0, 3, 0, 1 | Block1]),
+    NewPort =
+        if
+            BlkSize =:= 512 ->
+                %% Send READ
+                ReadBin = list_to_binary(ReadList),
+                ?VERIFY(ok, gen_udp:send(Socket, Host, Port, ReadBin)),
+
+                %% Sleep a while in order to provoke the server to re-send the packet
+                timer:sleep(Timeout + timer:seconds(1)),
+
+                %% Recv DATA #1 (the packet that the server think that we have lost)
+                {udp, _, _, NewPort0, _} = ?VERIFY({udp, Socket, Host, _, Data1Bin}, recv(Timeout)),
+                NewPort0;
+            true ->
+                %% Send READ
+                BlkSizeList = integer_to_list(BlkSize),
+                Options = ["blksize", 0, BlkSizeList, 0],
+                ReadBin = list_to_binary([ReadList | Options]),
+                ?VERIFY(ok, gen_udp:send(Socket, Host, Port, ReadBin)),
+
+                %% Recv OACK
+                OptionAckBin = list_to_binary([0, 6 | Options]),
+                {udp, _, _, NewPort0, _} = ?VERIFY({udp, Socket, Host, _, OptionAckBin}, recv(Timeout)),
+
+                %% Send ACK #0
+                Ack0Bin = <<0, 4, 0, 0>>,
+                ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort0, Ack0Bin)),
+
+                %% Send ACK #0 AGAIN (pretend that we timed out)
+                timer:sleep(timer:seconds(1)),
+                ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort0, Ack0Bin)),
+
+                %% Recv DATA #1 (the packet that the server think that we have lost)
+                ?VERIFY({udp, Socket, Host, NewPort0, Data1Bin}, recv(Timeout)),
+                NewPort0
+        end,
+
+    %% Recv DATA #1 AGAIN (the re-sent package)
+    ?VERIFY({udp, Socket, Host, NewPort, Data1Bin}, recv(Timeout)),
+
+    %% Send ACK #1
+    Ack1Bin = <<0, 4, 0, 1>>,
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Ack1Bin)),
+
+    %% Recv DATA #2
+    Data2Bin = list_to_binary([0, 3, 0, 2 | Block2]),
+    ?VERIFY({udp, Socket, Host, NewPort, Data2Bin}, recv(Timeout)),
+
+    %% Send ACK #2
+    Ack2Bin = <<0, 4, 0, 2>>,
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Ack2Bin)),
+
+    %% Recv DATA #3
+    Data3Bin = list_to_binary([0, 3, 0, 3 | Block3]),
+    ?VERIFY({udp, Socket, Host, NewPort, Data3Bin}, recv(Timeout)),
+
+    %% Send ACK #3
+    Ack3Bin = <<0, 4, 0, 3>>,
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Ack3Bin)),
+
+    %% Send ACK #3 AGAIN (pretend that we timed out)
+    timer:sleep(timer:seconds(1)),
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Ack3Bin)),
+
+    %% Recv DATA #4 (the packet that the server think that we have lost)
+    Data4Bin = list_to_binary([0, 3, 0, 4 | Block4]),
+    ?VERIFY({udp, Socket, Host, NewPort, Data4Bin}, recv(Timeout)),
+
+    %% Recv DATA #4 AGAIN (the re-sent package)
+    ?VERIFY({udp, Socket, Host, NewPort, Data4Bin}, recv(Timeout)),
+
+    %% Send ACK #2 which is out of range
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Ack2Bin)),
+
+    %% Send ACK #4
+    Ack4Bin = <<0, 4, 0, 4>>,
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Ack4Bin)),
+
+    %% Recv DATA #5
+    Data5Bin = list_to_binary([0, 3, 0, 5 | Block5]),
+    ?VERIFY({udp, Socket, Host, NewPort, Data5Bin}, recv(Timeout)),
+
+    %% Send ACK #5
+    Ack5Bin = <<0, 4, 0, 5>>,
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Ack5Bin)),
+
+    %% Close socket
+    ?VERIFY(ok, gen_udp:close(Socket)),
+
+    ?VERIFY(timeout, recv(Timeout)),
+    ?VERIFY(ok, file:delete(RemoteFilename)),
+    ok.
+
+resend_write_client(Host, Port, BlkSize) ->
+    RemoteFilename = "tftp_resend_write_client.tmp",
+    Block1 = lists:duplicate(BlkSize, $1),
+    Block2 = lists:duplicate(BlkSize, $2),
+    Block3 = lists:duplicate(BlkSize, $3),
+    Block4 = lists:duplicate(BlkSize, $4),
+    Block5 = lists:duplicate(BlkSize, $5),
+    Blocks = [Block1, Block2, Block3, Block4, Block5],
+    Blob = list_to_binary(Blocks),
+    ?IGNORE(file:delete(RemoteFilename)),
+    ?VERIFY({error, enoent}, file:read_file(RemoteFilename)),
+
+    Timeout = timer:seconds(3),
+    ?VERIFY(timeout, recv(0)),
+
+    %% Open socket
+    {ok, Socket} = ?VERIFY({ok, _}, gen_udp:open(0, [binary, {reuseaddr, true}, {active, true}])),
+
+    WriteList = [0, 2, RemoteFilename, 0, "octet", 0],
+    NewPort =
+        if
+            BlkSize =:= 512 ->
+                %% Send WRITE
+                WriteBin = list_to_binary(WriteList),
+                ?VERIFY(ok,  gen_udp:send(Socket, Host, Port, WriteBin)),
+
+                %% Sleep a while in order to provoke the server to re-send the packet
+                timer:sleep(Timeout + timer:seconds(1)),
+
+                %% Recv ACK #0 (the packet that the server think that we have lost)
+                Ack0Bin = <<0, 4, 0, 0>>,
+                ?VERIFY({udp, Socket, Host, _, Ack0Bin}, recv(Timeout)),
+
+                %% Recv ACK #0  AGAIN (the re-sent package)
+                {udp, _, _, NewPort0, _} = ?VERIFY({udp, Socket, Host, _, Ack0Bin}, recv(Timeout)),
+                NewPort0;
+            true ->
+                %% Send WRITE
+                BlkSizeList = integer_to_list(BlkSize),
+                WriteBin = list_to_binary([WriteList, "blksize", 0, BlkSizeList, 0]),
+                ?VERIFY(ok,  gen_udp:send(Socket, Host, Port, WriteBin)),
+
+                %% Sleep a while in order to provoke the server to re-send the packet
+                timer:sleep(timer:seconds(1)),
+
+                %% Recv OACK (the packet that the server think that we have lost)
+                OptionAckBin = list_to_binary([0, 6, "blksize",0, BlkSizeList, 0]),
+                ?VERIFY({udp, Socket, Host, _, OptionAckBin}, recv(Timeout)),
+                
+                %% Recv OACK AGAIN (the re-sent package)
+                {udp, _, _, NewPort0, _} = ?VERIFY({udp, Socket, Host, _, OptionAckBin}, recv(Timeout)),
+                NewPort0
+        end,
+
+    %% Send DATA #1
+    Data1Bin = list_to_binary([0, 3, 0, 1 | Block1]),
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Data1Bin)),
+
+    %% Recv ACK #1 
+    Ack1Bin = <<0, 4, 0, 1>>,
+    ?VERIFY({udp, Socket, Host, NewPort, Ack1Bin}, recv(Timeout)),
+
+    %% Send DATA #2
+    Data2Bin = list_to_binary([0, 3, 0, 2 | Block2]),
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Data2Bin)),
+
+    %% Recv ACK #2
+    Ack2Bin = <<0, 4, 0, 2>>,
+    ?VERIFY({udp, Socket, Host, NewPort, Ack2Bin}, recv(Timeout)),
+
+    %% Send DATA #3
+    Data3Bin = list_to_binary([0, 3, 0, 3 | Block3]),
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Data3Bin)),
+
+    %% Recv ACK #3
+    Ack3Bin = <<0, 4, 0, 3>>,
+    ?VERIFY({udp, Socket, Host, NewPort, Ack3Bin}, recv(Timeout)),
+
+    %% Send DATA #3 AGAIN (pretend that we timed out)
+    timer:sleep(timer:seconds(1)),
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Data3Bin)),
+
+    %% Recv ACK #3 AGAIN (the packet that the server think that we have lost)
+    ?VERIFY({udp, Socket, Host, NewPort, Ack3Bin}, recv(Timeout)),
+
+    %% Send DATA #2 which is out of range
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Data2Bin)),
+
+    %% Send DATA #4
+    Data4Bin = list_to_binary([0, 3, 0, 4 | Block4]),
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Data4Bin)),
+
+    %% Recv ACK #4
+    Ack4Bin = <<0, 4, 0, 4>>,
+    ?VERIFY({udp, Socket, Host, NewPort, Ack4Bin}, recv(Timeout)),
+
+    %% Send DATA #5
+    Data5Bin = list_to_binary([0, 3, 0, 5 | Block5]),
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Data5Bin)),
+
+    %% Recv ACK #5
+    Ack5Bin = <<0, 4, 0, 5>>,
+    ?VERIFY({udp, Socket, Host, NewPort, Ack5Bin}, recv(Timeout)),
+
+    %% Close socket
+    ?VERIFY(ok, gen_udp:close(Socket)),
+
+    ?VERIFY(timeout, recv(Timeout)),
+    ?VERIFY({ok, Blob}, file:read_file(RemoteFilename)),
+    ?VERIFY(ok, file:delete(RemoteFilename)),
+    ok.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Re-send server
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+resend_server(doc) ->
+    ["Verify that the server behaves correctly when the server re-sends packets."];
+resend_server(suite) ->
+    [];
+resend_server(Config) when is_list(Config) ->
+    Host = {127, 0, 0, 1},
+
+    ?VERIFY(ok, resend_read_server(Host, 10)),
+    ?VERIFY(ok, resend_read_server(Host, 512)),
+    ?VERIFY(ok, resend_read_server(Host, 1025)),
+    
+    ?VERIFY(ok, resend_write_server(Host, 10)),
+    ?VERIFY(ok, resend_write_server(Host, 512)),
+    ?VERIFY(ok, resend_write_server(Host, 1025)),
+    ok.
+
+resend_read_server(Host, BlkSize) ->
+    RemoteFilename = "tftp_resend_read_server.tmp",
+    Block1 = lists:duplicate(BlkSize, $1),
+    Block2 = lists:duplicate(BlkSize, $2),
+    Block3 = lists:duplicate(BlkSize, $3),
+    Block4 = lists:duplicate(BlkSize, $4),
+    Block5 = lists:duplicate(BlkSize, $5),
+    Block6 = [],
+    Blocks = [Block1, Block2, Block3, Block4, Block5, Block6],
+    Blob = list_to_binary(Blocks),
+
+    Timeout = timer:seconds(3),
+    ?VERIFY(timeout, recv(0)),
+
+    %% Open daemon socket
+    {ok, DaemonSocket} = ?VERIFY({ok, _}, gen_udp:open(0, [binary, {reuseaddr, true}, {active, true}])),
+    {ok, DaemonPort} = ?IGNORE(inet:port(DaemonSocket)),
+
+    %% Open server socket
+    {ok, ServerSocket} = ?VERIFY({ok, _}, gen_udp:open(0, [binary, {reuseaddr, true}, {active, true}])),
+    ?IGNORE(inet:port(ServerSocket)),
+
+    %% Prepare client process
+    ReplyTo = self(),
+    ClientFun =
+        fun(Extra) ->
+                Options = [{port, DaemonPort}, {debug, brief}] ++ Extra,
+                Res = ?VERIFY({ok, Blob}, tftp:read_file(RemoteFilename, binary, Options)),
+                ReplyTo ! {self(), {tftp_client_reply, Res}},
+                exit(normal)
+        end,
+
+    ReadList = [0, 1, RemoteFilename, 0, "octet", 0],
+    Data1Bin = list_to_binary([0, 3, 0, 1 | Block1]),
+    Ack1Bin = <<0, 4, 0, 1>>,
+    {ClientPort, ClientPid} =
+        if
+            BlkSize =:= 512 ->
+                %% Start client process
+                ClientPid0 = spawn_link(fun() -> ClientFun([]) end),
+
+                %% Recv READ
+                ReadBin = list_to_binary(ReadList),
+                {udp, _, _, ClientPort0, _} = ?VERIFY({udp, DaemonSocket, Host, _, ReadBin}, recv(Timeout)),
+
+                %% Send DATA #1
+                ?VERIFY(ok,  gen_udp:send(ServerSocket, Host, ClientPort0, Data1Bin)),
+
+                %% Sleep a while in order to provoke the client to re-send the packet
+                timer:sleep(Timeout + timer:seconds(1)),
+
+                %% Recv ACK #1 (the packet that the server think that we have lost)
+                ?VERIFY({udp, ServerSocket, Host, ClientPort0, Ack1Bin}, recv(Timeout)),
+
+                %% Recv ACK #1 AGAIN (the re-sent package)
+                ?VERIFY({udp, ServerSocket, Host, _, Ack1Bin}, recv(Timeout)),
+                {ClientPort0, ClientPid0};
+            true ->
+                %% Start client process
+                BlkSizeList = integer_to_list(BlkSize),
+                ClientPid0 = spawn_link(fun() -> ClientFun([{"blksize", BlkSizeList}]) end),
+                
+                %% Recv READ
+                Options = ["blksize", 0, BlkSizeList, 0],
+                ReadBin = list_to_binary([ReadList | Options]),
+                {udp, _, _, ClientPort0, _} = ?VERIFY({udp, DaemonSocket, Host, _, ReadBin}, recv(Timeout)),
+
+                %% Send OACK
+                BlkSizeList = integer_to_list(BlkSize),
+                OptionAckBin = list_to_binary([0, 6, "blksize",0, BlkSizeList, 0]),
+                ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort0, OptionAckBin)),
+
+                %% Sleep a while in order to provoke the client to re-send the packet
+                timer:sleep(Timeout + timer:seconds(1)),
+
+                %% Recv ACK #0 (the packet that the server think that we have lost)
+                Ack0Bin = <<0, 4, 0, 0>>,
+                ?VERIFY({udp, ServerSocket, Host, ClientPort0, Ack0Bin}, recv(Timeout)),
+
+                %% Recv ACK #0 AGAIN (the re-sent package)
+                ?VERIFY({udp, ServerSocket, Host, ClientPort0, Ack0Bin}, recv(Timeout)),
+
+                %% Send DATA #1
+                ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort0, Data1Bin)),
+
+                %% Recv ACK #1
+                ?VERIFY({udp, ServerSocket, Host, _, Ack1Bin}, recv(Timeout)),
+                {ClientPort0, ClientPid0}
+        end,
+
+    %% Send DATA #2
+    Data2Bin = list_to_binary([0, 3, 0, 2 | Block2]),
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Data2Bin)),
+
+    %% Recv ACK #2
+    Ack2Bin = <<0, 4, 0, 2>>,
+    ?VERIFY({udp, ServerSocket, Host, ClientPort, Ack2Bin}, recv(Timeout)),
+
+    %% Send DATA #3
+    Data3Bin = list_to_binary([0, 3, 0, 3 | Block3]),
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Data3Bin)),
+
+    %% Recv ACK #3
+    Ack3Bin = <<0, 4, 0, 3>>,
+    ?VERIFY({udp, ServerSocket, Host, ClientPort, Ack3Bin}, recv(Timeout)),
+
+    %% Send DATA #3 AGAIN (pretend that we timed out)
+    timer:sleep(timer:seconds(1)),
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Data3Bin)),
+
+    %% Recv ACK #3 AGAIN (the packet that the server think that we have lost)
+    ?VERIFY({udp, ServerSocket, Host, ClientPort, Ack3Bin}, recv(Timeout)),
+
+    %% Send DATA #4
+    Data4Bin = list_to_binary([0, 3, 0, 4 | Block4]),
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Data4Bin)),
+
+    %% Recv ACK #4
+    Ack4Bin = <<0, 4, 0, 4>>,
+    ?VERIFY({udp, ServerSocket, Host, ClientPort, Ack4Bin}, recv(Timeout)),
+
+    %% Send DATA #3 which is out of range
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Data3Bin)),
+
+    %% Send DATA #5
+    Data5Bin = list_to_binary([0, 3, 0, 5 | Block5]),
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Data5Bin)),
+
+    %% Recv ACK #5
+    Ack5Bin = <<0, 4, 0, 5>>,
+    ?VERIFY({udp, ServerSocket, Host, ClientPort, Ack5Bin}, recv(Timeout)),
+
+    %% Send DATA #6
+    Data6Bin = list_to_binary([0, 3, 0, 6 | Block6]),
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Data6Bin)),
+
+    %% Close daemon and server sockets
+    ?VERIFY(ok, gen_udp:close(ServerSocket)),
+    ?VERIFY(ok, gen_udp:close(DaemonSocket)),
+
+    ?VERIFY({ClientPid, {tftp_client_reply, {ok, Blob}}}, recv(Timeout)),
+
+    ?VERIFY(timeout, recv(Timeout)),
+    ok.
+
+resend_write_server(Host, BlkSize) ->
+    RemoteFilename = "tftp_resend_write_server.tmp",
+    Block1 = lists:duplicate(BlkSize, $1),
+    Block2 = lists:duplicate(BlkSize, $2),
+    Block3 = lists:duplicate(BlkSize, $3),
+    Block4 = lists:duplicate(BlkSize, $4),
+    Block5 = lists:duplicate(BlkSize, $5),
+    Block6 = [],
+    Blocks = [Block1, Block2, Block3, Block4, Block5, Block6],
+    Blob = list_to_binary(Blocks),
+    Size = size(Blob),
+
+    Timeout = timer:seconds(3),
+    ?VERIFY(timeout, recv(0)),
+
+    %% Open daemon socket
+    {ok, DaemonSocket} = ?VERIFY({ok, _}, gen_udp:open(0, [binary, {reuseaddr, true}, {active, true}])),
+    {ok, DaemonPort} = ?IGNORE(inet:port(DaemonSocket)),
+
+    %% Open server socket
+    {ok, ServerSocket} = ?VERIFY({ok, _}, gen_udp:open(0, [binary, {reuseaddr, true}, {active, true}])),
+    ?IGNORE(inet:port(ServerSocket)),
+
+    %% Prepare client process
+    ReplyTo = self(),
+    ClientFun =
+        fun(Extra) ->
+                Options = [{port, DaemonPort}, {debug, brief}] ++ Extra,
+                Res = ?VERIFY({ok, Size}, tftp:write_file(RemoteFilename, Blob, Options)),
+                ReplyTo ! {self(), {tftp_client_reply, Res}},
+                exit(normal)
+        end,
+
+    WriteList = [0, 2, RemoteFilename, 0, "octet", 0],
+    Data1Bin = list_to_binary([0, 3, 0, 1 | Block1]),
+    {ClientPort, ClientPid} =
+        if
+            BlkSize =:= 512 ->
+                %% Start client process
+                ClientPid0 = spawn_link(fun() -> ClientFun([]) end),
+
+                %% Recv WRITE
+                WriteBin = list_to_binary(WriteList),
+                io:format("WriteBin ~p\n", [WriteBin]),
+                {udp, _, _, ClientPort0, _} = ?VERIFY({udp, DaemonSocket, Host, _, WriteBin}, recv(Timeout)),
+
+                %% Send ACK #1
+                Ack0Bin = <<0, 4, 0, 0>>,
+                ?VERIFY(ok,  gen_udp:send(ServerSocket, Host, ClientPort0, Ack0Bin)),
+
+                %% Sleep a while in order to provoke the client to re-send the packet
+                timer:sleep(Timeout + timer:seconds(1)),
+
+                %% Recv DATA #1 (the packet that the server think that we have lost)
+                ?VERIFY({udp, ServerSocket, Host, ClientPort0, Data1Bin}, recv(Timeout)),
+
+                %% Recv DATA #1 AGAIN (the re-sent package)
+                ?VERIFY({udp, ServerSocket, Host, _, Data1Bin}, recv(Timeout)),
+                {ClientPort0, ClientPid0};
+            true ->
+                %% Start client process
+                BlkSizeList = integer_to_list(BlkSize),
+                ClientPid0 = spawn_link(fun() -> ClientFun([{"blksize", BlkSizeList}]) end),
+                
+                %% Recv WRITE
+                Options = ["blksize", 0, BlkSizeList, 0],
+                WriteBin = list_to_binary([WriteList | Options]),
+                {udp, _, _, ClientPort0, _} = ?VERIFY({udp, DaemonSocket, Host, _, WriteBin}, recv(Timeout)),
+
+                %% Send OACK
+                BlkSizeList = integer_to_list(BlkSize),
+                OptionAckBin = list_to_binary([0, 6, "blksize",0, BlkSizeList, 0]),
+                ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort0, OptionAckBin)),
+
+                %% Sleep a while in order to provoke the client to re-send the packet
+                timer:sleep(Timeout + timer:seconds(1)),
+
+                %% Recv DATA #1 (the packet that the server think that we have lost)
+                ?VERIFY({udp, ServerSocket, Host, ClientPort0, Data1Bin}, recv(Timeout)),
+
+                %% Recv DATA #1 AGAIN (the re-sent package)
+                ?VERIFY({udp, ServerSocket, Host, ClientPort0, Data1Bin}, recv(Timeout)),
+                {ClientPort0, ClientPid0}
+        end,
+
+    %% Send ACK #1
+    Ack1Bin = <<0, 4, 0, 1>>,
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Ack1Bin)),
+
+    %% Recv DATA #2
+    Data2Bin = list_to_binary([0, 3, 0, 2 | Block2]),
+    ?VERIFY({udp, ServerSocket, Host, ClientPort, Data2Bin}, recv(Timeout)),
+
+    %% Send ACK #2
+    Ack2Bin = <<0, 4, 0, 2>>,
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Ack2Bin)),
+
+    %% Recv DATA #3
+    Data3Bin = list_to_binary([0, 3, 0, 3 | Block3]),
+    ?VERIFY({udp, ServerSocket, Host, ClientPort, Data3Bin}, recv(Timeout)),
+
+    %% Send ACK #3
+    Ack3Bin = <<0, 4, 0, 3>>,
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Ack3Bin)),
+
+    %% Send ACK #3 AGAIN (pretend that we timed out)
+    timer:sleep(timer:seconds(1)),
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Ack3Bin)),
+
+    %% Recv DATA #4 (the packet that the server think that we have lost)
+    Data4Bin = list_to_binary([0, 3, 0, 4 | Block4]),
+    ?VERIFY({udp, ServerSocket, Host, ClientPort, Data4Bin}, recv(Timeout)),
+
+    %% Recv DATA #4 AGAIN (the re-sent package)
+    ?VERIFY({udp, ServerSocket, Host, ClientPort, Data4Bin}, recv(Timeout)),
+
+    %% Send ACK #4
+    Ack4Bin = <<0, 4, 0, 4>>,
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Ack4Bin)),
+
+    %% Recv DATA #5
+    Data5Bin = list_to_binary([0, 3, 0, 5 | Block5]),
+    ?VERIFY({udp, ServerSocket, Host, ClientPort, Data5Bin}, recv(Timeout)),
+
+    %% Send ACK #3 which is out of range
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Ack3Bin)),
+
+    %% Send ACK #5
+    Ack5Bin = <<0, 4, 0, 5>>,
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Ack5Bin)),
+
+    %% Recv DATA #6
+    Data6Bin = list_to_binary([0, 3, 0, 6 | Block6]),
+    ?VERIFY({udp, ServerSocket, Host, ClientPort, Data6Bin}, recv(Timeout)),
+
+    %% Send ACK #6
+    Ack6Bin = <<0, 4, 0, 6>>,
+    ?VERIFY(ok, gen_udp:send(ServerSocket, Host, ClientPort, Ack6Bin)),
+
+    %% Close daemon and server sockets
+    ?VERIFY(ok, gen_udp:close(ServerSocket)),
+    ?VERIFY(ok, gen_udp:close(DaemonSocket)),
+
+    ?VERIFY({ClientPid, {tftp_client_reply, {ok, Size}}}, recv(Timeout)),
+
+    ?VERIFY(timeout, recv(Timeout)),
+    ok.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+reuse_connection(doc) ->
+    ["Verify that the server can reuse an ongiong connection when same client resends request."];
+reuse_connection(suite) ->
+    [];
+reuse_connection(Config) when is_list(Config) ->
+    Host = {127, 0, 0, 1},
+    {Port, DaemonPid} = ?IGNORE(?START_DAEMON(0, [{debug, all}])),
+
+    RemoteFilename = "reuse_connection.tmp",
+    BlkSize = 512,
+    Block1 = lists:duplicate(BlkSize, $1),
+    Block2 = lists:duplicate(BlkSize div 2, $2),
+    Blocks = [Block1, Block2],
+    Blob = list_to_binary(Blocks),
+    ?VERIFY(ok, file:write_file(RemoteFilename, Blob)),
+    
+    Seconds = 3,
+    Timeout = timer:seconds(Seconds),
+    ?VERIFY(timeout, recv(0)),
+    
+    %% Open socket
+    {ok, Socket} = ?VERIFY({ok, _}, gen_udp:open(0, [binary, {reuseaddr, true}, {active, true}])),
+    
+    ReadList = [0, 1, RemoteFilename, 0, "octet", 0],
+    Data1Bin = list_to_binary([0, 3, 0, 1 | Block1]),
+    
+    %% Send READ
+    TimeoutList = integer_to_list(Seconds),
+    Options = ["timeout", 0, TimeoutList, 0],
+    ReadBin = list_to_binary([ReadList | Options]),
+    ?VERIFY(ok, gen_udp:send(Socket, Host, Port, ReadBin)),
+
+    %% Send yet another READ for same file
+    ?VERIFY(ok, gen_udp:send(Socket, Host, Port, ReadBin)),
+
+    %% Recv OACK
+    OptionAckBin = list_to_binary([0, 6 | Options]),
+    {udp, _, _, NewPort, _} = ?VERIFY({udp, Socket, Host, _, OptionAckBin}, recv(Timeout)),
+
+    %% Send ACK #0
+    Ack0Bin = <<0, 4, 0, 0>>,
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Ack0Bin)),
+
+    %% Recv DATA #1
+    ?VERIFY({udp, Socket, Host, NewPort, Data1Bin}, recv(Timeout)),
+
+    %% Send ACK #1
+    Ack1Bin = <<0, 4, 0, 1>>,
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Ack1Bin)),
+
+    %% Recv DATA #2
+    Data2Bin = list_to_binary([0, 3, 0, 2 | Block2]),
+    ?VERIFY({udp, Socket, Host, NewPort, Data2Bin}, recv(Timeout)),
+
+    %% Send ACK #2
+    Ack2Bin = <<0, 4, 0, 2>>,
+    ?VERIFY(ok, gen_udp:send(Socket, Host, NewPort, Ack2Bin)),
+
+    %% Close socket
+    ?VERIFY(ok, gen_udp:close(Socket)),
+
+    ?VERIFY(timeout, recv(Timeout)),
+    ?VERIFY(ok, file:delete(RemoteFilename)),
+
+    %% Cleanup
+    unlink(DaemonPid),
+    exit(DaemonPid, kill),
+    ok.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Large file: transfer > 65535 blocks
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+large_file(doc) ->
+    ["Start the daemon and test transfer of files greater than 32M."];
+large_file(suite) ->
+    [];
+large_file(Config) when is_list(Config) ->
+    ?VERIFY(ok, application:start(tftp)),
+
+    {Port, DaemonPid} = ?IGNORE(?START_DAEMON(0, [{debug, brief}])),
+
+    %% Read fail
+    RemoteFilename = "tftp_temporary_large_file_remote_test_file.txt",
+    LocalFilename = "tftp_temporary_large_file_local_test_file.txt",
+
+    {ok, FH} = file:open(LocalFilename, [write,exclusive]),
+    {ok, Size} = file:position(FH, {eof, 2*512*65535}),
+    ok = file:truncate(FH),
+    ?IGNORE(file:close(FH)),
+
+    %% Write and read
+    ?VERIFY({ok, Size}, tftp:write_file(RemoteFilename, LocalFilename, [{port, Port}])),
+    ?IGNORE(file:delete(LocalFilename)),
+    ?VERIFY({ok, Size}, tftp:read_file(RemoteFilename, LocalFilename, [{port, Port}])),
+
+    %% Cleanup
+    unlink(DaemonPid),
+    exit(DaemonPid, kill),
+    ?VERIFY(ok, file:delete(LocalFilename)),
+    ?VERIFY(ok, file:delete(RemoteFilename)),
+    ?VERIFY(ok, application:stop(tftp)),
+    ok.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Goodies
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+recv(Timeout) ->
+    receive
+        Msg ->
+            Msg
+    after Timeout ->
+            timeout
+    end.
diff --git a/lib/tftp/test/tftp_bench.spec b/lib/tftp/test/tftp_bench.spec
new file mode 100644
index 0000000000..43fa385c85
--- /dev/null
+++ b/lib/tftp/test/tftp_bench.spec
@@ -0,0 +1 @@
+{suites,"../tftp_test",[]}.
diff --git a/lib/tftp/test/tftp_test_lib.erl b/lib/tftp/test/tftp_test_lib.erl
new file mode 100644
index 0000000000..45386389cb
--- /dev/null
+++ b/lib/tftp/test/tftp_test_lib.erl
@@ -0,0 +1,308 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2007-2016. 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%
+%%
+
+-module(tftp_test_lib).
+
+-compile(export_all).
+
+-include("tftp_test_lib.hrl").
+
+%%
+%% -----
+%%
+
+init_per_testcase(_Case, Config) when is_list(Config) ->
+    io:format("\n ", []),
+    ?IGNORE(application:stop(tftp)),   
+    Config.
+
+end_per_testcase(_Case, Config) when is_list(Config) ->
+    ?IGNORE(application:stop(tftp)),   
+    Config.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% Infrastructure for test suite
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+error(Actual, Mod, Line) ->
+    (catch global:send(tftp_global_logger, {failed, Mod, Line})),
+    log("<ERROR> Bad result: ~p\n", [Actual], Mod, Line),
+    Label = lists:concat([Mod, "(", Line, ") unexpected result"]),
+    et:report_event(60, Mod, Mod, Label,
+			[{line, Mod, Line}, {error, Actual}]),
+    case global:whereis_name(tftp_test_case_sup) of
+	undefined -> 
+	    ignore;
+	Pid -> 
+	    Fail = #'REASON'{mod = Mod, line = Line, desc = Actual},
+	    Pid ! {fail, self(), Fail}
+    end,
+    Actual.
+
+log(Format, Args, Mod, Line) ->
+    case global:whereis_name(tftp_global_logger) of
+	undefined ->
+	    io:format(user, "~p(~p): " ++ Format, 
+		      [Mod, Line] ++ Args);
+	Pid ->
+	    io:format(Pid, "~p(~p): " ++ Format, 
+		      [Mod, Line] ++ Args)
+    end.
+
+default_config() ->
+    [].
+
+t() -> 
+    t([{?MODULE, all}]).
+
+t(Cases) ->
+    t(Cases, default_config()).
+
+t(Cases, Config) ->
+    process_flag(trap_exit, true),
+    Res = lists:flatten(do_test(Cases, Config)),
+    io:format("Res: ~p\n", [Res]),
+    display_result(Res),
+    Res.
+
+do_test({Mod, Fun}, Config) when is_atom(Mod), is_atom(Fun) ->
+    case catch apply(Mod, Fun, [suite]) of
+	[] ->
+	    io:format("Eval:   ~p:", [{Mod, Fun}]),
+	    Res = eval(Mod, Fun, Config),
+	    {R, _, _} = Res,
+	    io:format(" ~p\n", [R]),
+	    Res;
+
+	Cases when is_list(Cases) ->
+	    io:format("Expand: ~p ...\n", [{Mod, Fun}]),
+	    Map = fun(Case) when is_atom(Case)-> {Mod, Case};
+		     (Case) -> Case
+		  end,
+	    do_test(lists:map(Map, Cases), Config);
+
+        {req, _, {conf, Init, Cases, Finish}} ->
+	    case (catch apply(Mod, Init, [Config])) of
+		Conf when is_list(Conf) ->
+		    io:format("Expand: ~p ...\n", [{Mod, Fun}]),
+		    Map = fun(Case) when is_atom(Case)-> {Mod, Case};
+			     (Case) -> Case
+			  end,
+		    Res = do_test(lists:map(Map, Cases), Conf),
+		    (catch apply(Mod, Finish, [Conf])),
+		    Res;
+		    
+		{'EXIT', {skipped, Reason}} ->
+		    io:format(" => skipping: ~p\n", [Reason]),
+		    [{skipped, {Mod, Fun}, Reason}];
+		    
+		Error ->
+		    io:format(" => failed: ~p\n", [Error]),
+		    [{failed, {Mod, Fun}, Error}]
+	    end;
+		    
+        {'EXIT', {undef, _}} ->
+	    io:format("Undefined:   ~p\n", [{Mod, Fun}]),
+	    [{nyi, {Mod, Fun}, ok}];
+		    
+        Error ->
+	    io:format("Ignoring:   ~p: ~p\n", [{Mod, Fun}, Error]),
+	    [{failed, {Mod, Fun}, Error}]
+    end;
+do_test(Mod, Config) when is_atom(Mod) ->
+    Res = do_test({Mod, all}, Config),
+    Res;
+do_test(Cases, Config) when is_list(Cases) ->
+    [do_test(Case, Config) || Case <- Cases];
+do_test(Bad, _Config) ->
+    [{badarg, Bad, ok}].
+
+eval(Mod, Fun, Config) ->
+    TestCase = {?MODULE, Mod, Fun},
+    Label = lists:concat(["TEST CASE: ", Fun]),
+    et:report_event(40, ?MODULE, Mod, Label ++ " started",
+			[TestCase, Config]),
+    global:register_name(tftp_test_case_sup, self()),
+    Flag = process_flag(trap_exit, true),
+    Config2 = Mod:init_per_testcase(Fun, Config),
+    Pid = spawn_link(?MODULE, do_eval, [self(), Mod, Fun, Config2]),
+    R = wait_for_evaluator(Pid, Mod, Fun, Config2, []),
+    Mod:end_per_testcase(Fun, Config2),
+    global:unregister_name(tftp_test_case_sup),
+    process_flag(trap_exit, Flag),
+    R.
+
+wait_for_evaluator(Pid, Mod, Fun, Config, Errors) ->
+    TestCase = {?MODULE, Mod, Fun},
+    Label = lists:concat(["TEST CASE: ", Fun]),
+    receive
+	{done, Pid, ok} when Errors == [] ->
+	    et:report_event(40, Mod, ?MODULE, Label ++ " ok",
+				[TestCase, Config]),
+	    {ok, {Mod, Fun}, Errors};
+	{done, Pid, {ok, _}} when Errors == [] ->
+	    et:report_event(40, Mod, ?MODULE, Label ++ " ok",
+				[TestCase, Config]),
+	    {ok, {Mod, Fun}, Errors};
+	{done, Pid, Fail} ->
+	    et:report_event(20, Mod, ?MODULE, Label ++ " failed",
+				[TestCase, Config, {return, Fail}, Errors]),
+	    {failed, {Mod,Fun}, Fail};
+	{'EXIT', Pid, {skipped, Reason}} -> 
+	    et:report_event(20, Mod, ?MODULE, Label ++ " skipped",
+				[TestCase, Config, {skipped, Reason}]),
+	    {skipped, {Mod, Fun}, Errors};
+	{'EXIT', Pid, Reason} -> 
+	    et:report_event(20, Mod, ?MODULE, Label ++ " crashed",
+				[TestCase, Config, {'EXIT', Reason}]),
+	    {crashed, {Mod, Fun}, [{'EXIT', Reason} | Errors]};
+	{fail, Pid, Reason} ->
+	    wait_for_evaluator(Pid, Mod, Fun, Config, Errors ++ [Reason])
+    end.
+
+do_eval(ReplyTo, Mod, Fun, Config) ->
+    case (catch apply(Mod, Fun, [Config])) of
+	{'EXIT', {skipped, Reason}} ->
+	    ReplyTo ! {'EXIT', self(), {skipped, Reason}};
+	Other ->
+	    ReplyTo ! {done, self(), Other}
+    end,
+    unlink(ReplyTo),
+    exit(shutdown).
+
+display_result([]) ->    
+    io:format("OK\n", []);
+display_result(Res) when is_list(Res) ->
+    Ok      = [MF || {ok, MF, _}  <- Res],
+    Nyi     = [MF || {nyi, MF, _} <- Res],
+    Skipped = [{MF, Reason} || {skipped, MF, Reason} <- Res],
+    Failed  = [{MF, Reason} || {failed, MF, Reason} <- Res],
+    Crashed = [{MF, Reason} || {crashed, MF, Reason} <- Res],
+    display_summary(Ok, Nyi, Skipped, Failed, Crashed),
+    display_skipped(Skipped),
+    display_failed(Failed),
+    display_crashed(Crashed).
+
+display_summary(Ok, Nyi, Skipped, Failed, Crashed) ->
+    io:format("\nTest case summary:\n", []),
+    display_summary(Ok,      "successful"),
+    display_summary(Nyi,     "not yet implemented"),
+    display_summary(Skipped, "skipped"),
+    display_summary(Failed,  "failed"),
+    display_summary(Crashed, "crashed"),
+    io:format("\n", []).
+   
+display_summary(Res, Info) ->
+    io:format("  ~w test cases ~s\n", [length(Res), Info]).
+    
+display_skipped([]) ->
+    ok;
+display_skipped(Skipped) ->
+    io:format("Skipped test cases:\n", []),
+    F = fun({MF, Reason}) -> io:format("  ~p => ~p\n", [MF, Reason]) end,
+    lists:foreach(F, Skipped),
+    io:format("\n", []).
+    
+
+display_failed([]) ->
+    ok;
+display_failed(Failed) ->
+    io:format("Failed test cases:\n", []),
+    F = fun({MF, Reason}) -> io:format("  ~p => ~p\n", [MF, Reason]) end,
+    lists:foreach(F, Failed),
+    io:format("\n", []).
+
+display_crashed([]) ->
+    ok;
+display_crashed(Crashed) ->
+    io:format("Crashed test cases:\n", []),
+    F = fun({MF, Reason}) -> io:format("  ~p => ~p\n", [MF, Reason]) end,
+    lists:foreach(F, Crashed),
+    io:format("\n", []).
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% generic callback
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+-record(generic_state, {state, prepare, open, read, write, abort}).
+
+prepare(Peer, Access, LocalFilename, Mode, SuggestedOptions, Initial) when is_list(Initial) ->
+    State   = lookup_option(state,   mandatory, Initial),
+    Prepare = lookup_option(prepare, mandatory, Initial),
+    Open    = lookup_option(open,    mandatory, Initial),
+    Read    = lookup_option(read,    mandatory, Initial),
+    Write   = lookup_option(write,   mandatory, Initial),
+    Abort   = lookup_option(abort,   mandatory, Initial),
+    case Prepare(Peer, Access, LocalFilename, Mode, SuggestedOptions, State) of
+	{ok, AcceptedOptions, NewState} ->
+	    {ok,
+	     AcceptedOptions,
+	     #generic_state{state   = NewState,
+			    prepare = Prepare,
+			    open    = Open,
+			    read    = Read,
+			    write   = Write,
+			    abort   = Abort}};
+	Other ->
+	    Other
+    end.
+
+open(Peer, Access, LocalFilename, Mode, SuggestedOptions, Initial) when is_list(Initial) ->
+    case prepare(Peer, Access, LocalFilename, Mode, SuggestedOptions, Initial) of
+ 	{ok, SuggestedOptions2, GenericState} ->
+	    open(Peer, Access, LocalFilename, Mode, SuggestedOptions2, GenericState);
+	Other ->
+	    Other
+    end;
+open(Peer, Access, LocalFilename, Mode, SuggestedOptions, #generic_state{state = State, open = Open} = GenericState) ->
+    case Open(Peer, Access, LocalFilename, Mode, SuggestedOptions, State) of
+	{ok, SuggestedOptions2, NewState} ->
+	    {ok, SuggestedOptions2, GenericState#generic_state{state = NewState}};
+	Other ->
+	    Other
+    end.
+
+read(#generic_state{state = State, read = Read} = GenericState) ->
+    case Read(State) of
+	{more, DataBlock, NewState} ->
+	    {more, DataBlock, GenericState#generic_state{state = NewState}};
+	Other ->
+	    Other
+    end.
+
+write(DataBlock, #generic_state{state = State, write = Write} = GenericState) ->
+    case Write(DataBlock, State) of
+	{more, NewState} ->
+	    {more, GenericState#generic_state{state = NewState}};
+	Other ->
+	    Other
+    end.
+
+abort(Code, Text, #generic_state{state = State, abort = Abort}) ->
+    Abort(Code, Text, State).
+
+lookup_option(Key, Default, Options) ->
+    case lists:keysearch(Key, 1, Options) of
+	{value, {_, Val}} ->
+	    Val;
+	false ->
+	    Default
+    end.
+
diff --git a/lib/tftp/test/tftp_test_lib.hrl b/lib/tftp/test/tftp_test_lib.hrl
new file mode 100644
index 0000000000..e7a5a37d2c
--- /dev/null
+++ b/lib/tftp/test/tftp_test_lib.hrl
@@ -0,0 +1,44 @@
+%%
+%% %CopyrightBegin%
+%% 
+%% Copyright Ericsson AB 2007-2016. 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%
+%%
+
+-record('REASON', {mod, line, desc}).
+
+-define(LOG(Format, Args),
+	tftp_test_lib:log(Format, Args, ?MODULE, ?LINE)).
+
+-define(ERROR(Reason),
+	tftp_test_lib:error(Reason, ?MODULE, ?LINE)).
+
+-define(VERIFY(Expected, Expr),
+	fun() ->
+		AcTuAlReS = (catch (Expr)),
+		case AcTuAlReS of
+		    Expected -> ?LOG("Ok, ~p\n", [AcTuAlReS]);
+		    _        ->	?ERROR(AcTuAlReS)
+	       end,
+		AcTuAlReS
+	end()).
+
+-define(IGNORE(Expr), 
+	fun() ->
+		AcTuAlReS = (catch (Expr)),
+		?LOG("Ok, ~p\n", [AcTuAlReS]),
+		AcTuAlReS
+	end()).