From de1d8909c3eb66a5326ee93908dc55899aa862cb Mon Sep 17 00:00:00 2001
From: EMQ-YangM <yangm@emqx.io>
Date: Wed, 18 May 2022 10:32:02 +0800
Subject: [PATCH] fix: hexstr2bin support half byte

---
 CHANGES-4.3.md                                     |  1 +
 .../test/emqx_rule_funcs_SUITE.erl                 |  8 ++++++--
 src/emqx.appup.src                                 | 14 +++++++++-----
 src/emqx_misc.erl                                  | 14 +++++++++++++-
 4 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/CHANGES-4.3.md b/CHANGES-4.3.md
index 8b509fe17..566022ddf 100644
--- a/CHANGES-4.3.md
+++ b/CHANGES-4.3.md
@@ -27,6 +27,7 @@ File format:
 * List subscription topic (/api/v4/subscriptions), the result do not match with multiple conditions.
 * SSL closed error bug fixed for redis client.
 * Fix mqtt-sn client disconnected due to re-send a duplicated qos2 message
+* rule-engine function hexstr2bin/1 support half byte
 
 * Improved resilience against autocluster partitioning during cluster
   startup. [#7876]
diff --git a/apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl b/apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl
index cf07da20f..116c99f29 100644
--- a/apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl
+++ b/apps/emqx_rule_engine/test/emqx_rule_funcs_SUITE.erl
@@ -159,8 +159,12 @@ t_term_encode(_) ->
         end, TestData).
 
 t_hexstr2bin(_) ->
-    ?assertEqual(<<1,2>>, emqx_rule_funcs:hexstr2bin(<<"0102">>)),
-    ?assertEqual(<<17,33>>, emqx_rule_funcs:hexstr2bin(<<"1121">>)).
+    ?assertEqual(<<6, 54, 79>>, emqx_rule_funcs:hexstr2bin(<<"6364f">>)),
+    ?assertEqual(<<10>>, emqx_rule_funcs:hexstr2bin(<<"a">>)),
+    ?assertEqual(<<15>>, emqx_rule_funcs:hexstr2bin(<<"f">>)),
+    ?assertEqual(<<5>>, emqx_rule_funcs:hexstr2bin(<<"5">>)),
+    ?assertEqual(<<1, 2>>, emqx_rule_funcs:hexstr2bin(<<"0102">>)),
+    ?assertEqual(<<17, 33>>, emqx_rule_funcs:hexstr2bin(<<"1121">>)).
 
 t_bin2hexstr(_) ->
     ?assertEqual(<<"0102">>, emqx_rule_funcs:bin2hexstr(<<1,2>>)),
diff --git a/src/emqx.appup.src b/src/emqx.appup.src
index be7c60261..ea2c006bc 100644
--- a/src/emqx.appup.src
+++ b/src/emqx.appup.src
@@ -2,13 +2,15 @@
 %% Unless you know what you are doing, DO NOT edit manually!!
 {VSN,
   [{"4.3.15",
-    [{load_module,emqx_frame,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_misc,brutal_purge,soft_purge,[]},
+     {load_module,emqx_frame,brutal_purge,soft_purge,[]},
      {load_module,emqx_channel,brutal_purge,soft_purge,[]},
      {load_module,emqx_access_rule,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]}]},
    {"4.3.14",
-    [{load_module,emqx_access_rule,brutal_purge,soft_purge,[]},
-    {load_module,emqx_channel,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_misc,brutal_purge,soft_purge,[]},
+     {load_module,emqx_access_rule,brutal_purge,soft_purge,[]},
+     {load_module,emqx_channel,brutal_purge,soft_purge,[]},
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_sys,brutal_purge,soft_purge,[]},
      {load_module,emqx_plugins,brutal_purge,soft_purge,[]},
@@ -459,12 +461,14 @@
      {load_module,emqx_limiter,brutal_purge,soft_purge,[]}]},
    {<<".*">>,[]}],
   [{"4.3.15",
-    [{load_module,emqx_frame,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_misc,brutal_purge,soft_purge,[]},
+     {load_module,emqx_frame,brutal_purge,soft_purge,[]},
      {load_module,emqx_channel,brutal_purge,soft_purge,[]},
      {load_module,emqx_access_rule,brutal_purge,soft_purge,[]},
      {load_module,emqx_app,brutal_purge,soft_purge,[]}]},
    {"4.3.14",
-    [{load_module,emqx_access_rule,brutal_purge,soft_purge,[]},
+    [{load_module,emqx_misc,brutal_purge,soft_purge,[]},
+     {load_module,emqx_access_rule,brutal_purge,soft_purge,[]},
      {load_module,emqx,brutal_purge,soft_purge,[]},
      {load_module,emqx_channel,brutal_purge,soft_purge,[]},
      {load_module,emqx_sys,brutal_purge,soft_purge,[]},
diff --git a/src/emqx_misc.erl b/src/emqx_misc.erl
index cc0d7d247..36a3386e3 100644
--- a/src/emqx_misc.erl
+++ b/src/emqx_misc.erl
@@ -317,7 +317,19 @@ int2hexchar(I, lower) -> I - 10 + $a.
 
 -spec(hexstr2bin(binary()) -> binary()).
 hexstr2bin(B) when is_binary(B) ->
-    << <<(hexchar2int(H)*16 + hexchar2int(L))>> || <<H:8, L:8>> <= B>>.
+    hexstr2bin(B, erlang:bit_size(B)).
+
+hexstr2bin(B, Size) when is_binary(B) ->
+    case Size rem 16 of
+        0 ->
+            make_binary(B);
+        8 ->
+            make_binary(<<"0", B/binary>>);
+        _ ->
+            throw({unsupport_hex_string, B, Size})
+    end.
+
+make_binary(B) -> <<<<(hexchar2int(H) * 16 + hexchar2int(L))>> || <<H:8, L:8>> <= B>>.
 
 hexchar2int(I) when I >= $0 andalso I =< $9 -> I - $0;
 hexchar2int(I) when I >= $A andalso I =< $F -> I - $A + 10;