From 58320aecbedfd0380b4effcc18f213f7fbb883bd Mon Sep 17 00:00:00 2001
From: bol-van <none@none.none>
Date: Sun, 28 Dec 2025 12:49:09 +0300
Subject: [PATCH] nfqws2: swap24

---
 docs/manual.md |  1 +
 nfq2/helpers.c |  4 ++++
 nfq2/helpers.h |  1 +
 nfq2/lua.c     | 11 +++++++++++
 4 files changed, 17 insertions(+)

diff --git a/docs/manual.md b/docs/manual.md
index 0522291..7f91f94 100644
--- a/docs/manual.md
+++ b/docs/manual.md
@@ -1752,6 +1752,7 @@ function bu48(u48)
 
 ```
 function swap16(u16)
+function swap24(u24)
 function swap32(u32)
 function swap48(u48)
 ```
diff --git a/nfq2/helpers.c b/nfq2/helpers.c
index ea78514..bd7aa5a 100644
--- a/nfq2/helpers.c
+++ b/nfq2/helpers.c
@@ -401,6 +401,10 @@ uint16_t swap16(uint16_t u)
 	// __builtin_bswap16 is absent in ancient lexra gcc 4.6
 	return (u>>8) | ((u&0xFF)<<8);
 }
+uint32_t swap24(uint32_t u)
+{
+	return (u>>16) & 0xFF | u & 0xFF00 | (u<<16) & 0xFF0000;
+}
 uint64_t swap48(uint64_t u)
 {
 	return ((u & 0xFF0000000000) >> 40) | ((u & 0xFF00000000) >> 24) | ((u & 0xFF000000) >> 8) | ((u & 0xFF0000) << 8) | ((u & 0xFF00) << 24) | ((u & 0xFF) << 40);
diff --git a/nfq2/helpers.h b/nfq2/helpers.h
index 109bc8f..254e9b6 100644
--- a/nfq2/helpers.h
+++ b/nfq2/helpers.h
@@ -67,6 +67,7 @@ uint64_t pntoh64(const uint8_t *p);
 void phton64(uint8_t *p, uint64_t v);
 
 uint16_t swap16(uint16_t u);
+uint32_t swap24(uint32_t u);
 uint64_t swap48(uint64_t u);
 
 bool parse_hex_str(const char *s, uint8_t *pbuf, size_t *size);
diff --git a/nfq2/lua.c b/nfq2/lua.c
index 64120b4..bfac2ed 100644
--- a/nfq2/lua.c
+++ b/nfq2/lua.c
@@ -281,6 +281,16 @@ static int luacall_swap16(lua_State *L)
 	lua_pushinteger(L,swap16(u));
 	return 1;
 }
+static int luacall_swap24(lua_State *L)
+{
+	lua_check_argc(L,"swap24",1);
+
+	int64_t i =(int64_t)luaL_checklint(L,1);
+	if (i>0xFFFFFF || i<-(int64_t)0xFFFFFF) luaL_error(L, "out of range");
+	uint32_t u = (uint32_t)i;
+	lua_pushlint(L,swap24(u));
+	return 1;
+}
 static int luacall_swap32(lua_State *L)
 {
 	lua_check_argc(L,"swap32",1);
@@ -3186,6 +3196,7 @@ static void lua_init_functions(void)
 		{"bu48",luacall_bu48},
 		// swap byte order
 		{"swap16",luacall_swap16},
+		{"swap24",luacall_swap24},
 		{"swap32",luacall_swap32},
 		{"swap48",luacall_swap48},