diff --git a/src/dupkt_filter/dupkt_filter.cpp b/src/dupkt_filter/dupkt_filter.cpp
index ec34405..c7e667a 100644
--- a/src/dupkt_filter/dupkt_filter.cpp
+++ b/src/dupkt_filter/dupkt_filter.cpp
@@ -17,8 +17,8 @@ struct dupkt_filter_key
 
     // IPv4
     uint16_t ip_id;
-    struct in_addr src_addr; /* network order */
-    struct in_addr dst_addr; /* network order */
+    uint32_t src_addr; /* host order */
+    uint32_t dst_addr; /* host order */
 } __attribute__((__packed__));
 
 struct dupkt_filter
@@ -53,9 +53,9 @@ static inline int packet_get_dupkt_filter_key(const struct packet *packet, struc
     memset(key, 0, sizeof(struct dupkt_filter_key));
 
     const struct ip *iphdr = (const struct ip *)ipv4_layer->hdr_ptr;
-    key->ip_id = ipv4_hdr_get_id(iphdr);
-    key->src_addr = ipv4_hdr_get_net_order_saddr(iphdr);
-    key->dst_addr = ipv4_hdr_get_net_order_daddr(iphdr);
+    key->ip_id = ipv4_hdr_get_ipid(iphdr);
+    key->src_addr = ipv4_hdr_get_src_addr(iphdr);
+    key->dst_addr = ipv4_hdr_get_dst_addr(iphdr);
 
     const struct tcphdr *tcphdr = (const struct tcphdr *)tcp_layer->hdr_ptr;
     key->seq = tcp_hdr_get_seq(tcphdr);
diff --git a/src/packet/ipv4_helpers.h b/src/packet/ipv4_helpers.h
deleted file mode 100644
index e8e5671..0000000
--- a/src/packet/ipv4_helpers.h
+++ /dev/null
@@ -1,146 +0,0 @@
-#ifndef _IPV4_HELPERS_H
-#define _IPV4_HELPERS_H
-
-#ifdef __cpluscplus
-extern "C"
-{
-#endif
-
-#include <arpa/inet.h>
-#include <netinet/ip.h>
-
-/*
- * Internet Header Format
- *
- *   0                   1                   2                   3
- *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
- *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- *  |Version|  IHL  |Type of Service|          Total Length         |
- *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- *  |         Identification        |Flags|      Fragment Offset    |
- *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- *  |  Time to Live |    Protocol   |         Header Checksum       |
- *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- *  |                       Source Address                          |
- *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- *  |                    Destination Address                        |
- *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- *  |                    Options                    |    Padding    |
- *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- */
-
-static inline uint8_t ipv4_hdr_get_version(const struct ip *hdr)
-{
-    return hdr->ip_v;
-}
-
-static inline uint8_t ipv4_hdr_get_hl(const struct ip *hdr)
-{
-    return hdr->ip_hl << 2;
-}
-
-static inline uint8_t ipv4_hdr_get_tos(const struct ip *hdr)
-{
-    return hdr->ip_tos;
-}
-
-static inline uint16_t ipv4_hdr_get_len(const struct ip *hdr)
-{
-    return ntohs(hdr->ip_len);
-}
-
-static inline uint16_t ipv4_hdr_get_ipid(const struct ip *hdr)
-{
-    return ntohs(hdr->ip_id);
-}
-
-static inline uint8_t ipv4_hdr_get_flags(const struct ip *hdr)
-{
-    return (ntohs(hdr->ip_off) & (~IP_OFFMASK)) >> 13;
-}
-
-static inline bool ipv4_hdr_has_flag_rf(const struct ip *hdr)
-{
-    return (ntohs(hdr->ip_off) & IP_RF) != 0;
-}
-
-static inline bool ipv4_hdr_has_flag_df(const struct ip *hdr)
-{
-    return (ntohs(hdr->ip_off) & IP_DF) != 0;
-}
-
-static inline bool ipv4_hdr_has_flag_mf(const struct ip *hdr)
-{
-    return (ntohs(hdr->ip_off) & IP_MF) != 0;
-}
-
-static inline uint16_t ipv4_hdr_get_frag_offset(const struct ip *hdr)
-{
-    return (ntohs(hdr->ip_off) & IP_OFFMASK) << 3;
-}
-
-static inline uint8_t ipv4_hdr_get_ttl(const struct ip *hdr)
-{
-    return hdr->ip_ttl;
-}
-
-static inline uint8_t ipv4_hdr_get_protocol(const struct ip *hdr)
-{
-    return hdr->ip_p;
-}
-
-static inline uint16_t ipv4_hdr_get_checksum(const struct ip *hdr)
-{
-    return ntohs(hdr->ip_sum);
-}
-
-static inline uint32_t ipv4_hdr_get_host_order_saddr(const struct ip *hdr)
-{
-    return ntohl(hdr->ip_src.s_addr);
-}
-
-static inline uint32_t ipv4_hdr_get_host_order_daddr(const struct ip *hdr)
-{
-    return ntohl(hdr->ip_dst.s_addr);
-}
-
-static inline struct in_addr ipv4_hdr_get_net_order_saddr(const struct ip *hdr)
-{
-    return hdr->ip_src;
-}
-
-static inline struct in_addr ipv4_hdr_get_net_order_daddr(const struct ip *hdr)
-{
-    return hdr->ip_dst;
-}
-
-static inline uint8_t ipv4_hdr_get_opt_len(const struct ip *hdr)
-{
-    return ipv4_hdr_get_hl(hdr) - sizeof(struct ip);
-}
-
-static inline const uint8_t *ipv4_hdr_get_opt_ptr(const struct ip *hdr)
-{
-    return (const uint8_t *)hdr + sizeof(struct ip);
-}
-
-static inline void ipv4_hdr_set_ipid(struct ip *hdr, uint16_t ipid)
-{
-    hdr->ip_id = htons(ipid);
-}
-
-static inline void ipv4_hdr_set_host_order_saddr(struct ip *hdr, uint32_t saddr)
-{
-    hdr->ip_src.s_addr = htonl(saddr);
-}
-
-static inline void ipv4_hdr_set_host_order_daddr(struct ip *hdr, uint32_t daddr)
-{
-    hdr->ip_dst.s_addr = htonl(daddr);
-}
-
-#ifdef __cpluscplus
-}
-#endif
-
-#endif
diff --git a/src/packet/ipv4_utils.h b/src/packet/ipv4_utils.h
new file mode 100644
index 0000000..761f222
--- /dev/null
+++ b/src/packet/ipv4_utils.h
@@ -0,0 +1,237 @@
+#ifndef _IPV4_UTILS_H
+#define _IPV4_UTILS_H
+
+#ifdef __cpluscplus
+extern "C"
+{
+#endif
+
+#include <string.h>
+#include <arpa/inet.h>
+#include <netinet/ip.h>
+
+/*
+ * Internet Header Format
+ *
+ *   0                   1                   2                   3
+ *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |Version|  IHL  |Type of Service|          Total Length         |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |         Identification        |Flags|      Fragment Offset    |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |  Time to Live |    Protocol   |         Header Checksum       |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                       Source Address                          |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                    Destination Address                        |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                    Options                    |    Padding    |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+
+/******************************************************************************
+ * get
+ ******************************************************************************/
+
+static inline uint8_t ipv4_hdr_get_version(const struct ip *hdr)
+{
+    return hdr->ip_v;
+}
+
+static inline uint8_t ipv4_hdr_get_hdr_len(const struct ip *hdr)
+{
+    return hdr->ip_hl << 2;
+}
+
+static inline uint8_t ipv4_hdr_get_tos(const struct ip *hdr)
+{
+    return hdr->ip_tos;
+}
+
+static inline uint16_t ipv4_hdr_get_total_len(const struct ip *hdr)
+{
+    return ntohs(hdr->ip_len);
+}
+
+static inline uint16_t ipv4_hdr_get_ipid(const struct ip *hdr)
+{
+    return ntohs(hdr->ip_id);
+}
+
+static inline uint8_t ipv4_hdr_get_flags(const struct ip *hdr)
+{
+    return (ntohs(hdr->ip_off) & (~IP_OFFMASK)) >> 13;
+}
+
+static inline bool ipv4_hdr_get_rf_flag(const struct ip *hdr)
+{
+    return (ntohs(hdr->ip_off) & IP_RF) != 0;
+}
+
+static inline bool ipv4_hdr_get_df_flag(const struct ip *hdr)
+{
+    return (ntohs(hdr->ip_off) & IP_DF) != 0;
+}
+
+static inline bool ipv4_hdr_get_mf_flag(const struct ip *hdr)
+{
+    return (ntohs(hdr->ip_off) & IP_MF) != 0;
+}
+
+static inline uint16_t ipv4_hdr_get_frag_offset(const struct ip *hdr)
+{
+    return (ntohs(hdr->ip_off) & IP_OFFMASK) << 3;
+}
+
+static inline uint8_t ipv4_hdr_get_ttl(const struct ip *hdr)
+{
+    return hdr->ip_ttl;
+}
+
+static inline uint8_t ipv4_hdr_get_proto(const struct ip *hdr)
+{
+    return hdr->ip_p;
+}
+
+static inline uint16_t ipv4_hdr_get_checksum(const struct ip *hdr)
+{
+    return ntohs(hdr->ip_sum);
+}
+
+static inline uint32_t ipv4_hdr_get_src_addr(const struct ip *hdr)
+{
+    return ntohl(hdr->ip_src.s_addr);
+}
+
+static inline uint32_t ipv4_hdr_get_dst_addr(const struct ip *hdr)
+{
+    return ntohl(hdr->ip_dst.s_addr);
+}
+
+static inline uint8_t ipv4_hdr_get_opt_len(const struct ip *hdr)
+{
+    return ipv4_hdr_get_hdr_len(hdr) - sizeof(struct ip);
+}
+
+static inline const char *ipv4_hdr_get_opt_data(const struct ip *hdr)
+{
+    return (const char *)hdr + sizeof(struct ip);
+}
+
+/******************************************************************************
+ * set
+ ******************************************************************************/
+
+static inline void ipv4_hdr_set_version(struct ip *hdr, uint8_t version)
+{
+    hdr->ip_v = version;
+}
+
+static inline void ipv4_hdr_set_hdr_len(struct ip *hdr, uint8_t hdr_len)
+{
+    hdr->ip_hl = hdr_len >> 2;
+}
+
+static inline void ipv4_hdr_set_tos(struct ip *hdr, uint8_t tos)
+{
+    hdr->ip_tos = tos;
+}
+
+static inline void ipv4_hdr_set_total_len(struct ip *hdr, uint16_t total_len)
+{
+    hdr->ip_len = htons(total_len);
+}
+
+static inline void ipv4_hdr_set_ipid(struct ip *hdr, uint16_t ipid)
+{
+    hdr->ip_id = htons(ipid);
+}
+
+static inline void ipv4_hdr_set_flags(struct ip *hdr, uint8_t flags)
+{
+    hdr->ip_off = htons((flags << 13) | (ntohs(hdr->ip_off) & IP_OFFMASK));
+}
+
+static inline void ipv4_hdr_set_rf_flag(struct ip *hdr, bool flag)
+{
+    if (flag)
+    {
+        hdr->ip_off = htons(ntohs(hdr->ip_off) | IP_RF);
+    }
+    else
+    {
+        hdr->ip_off = htons(ntohs(hdr->ip_off) & ~IP_RF);
+    }
+}
+
+static inline void ipv4_hdr_set_df_flag(struct ip *hdr, bool flag)
+{
+    if (flag)
+    {
+        hdr->ip_off = htons(ntohs(hdr->ip_off) | IP_DF);
+    }
+    else
+    {
+        hdr->ip_off = htons(ntohs(hdr->ip_off) & ~IP_DF);
+    }
+}
+
+static inline void ipv4_hdr_set_mf_flag(struct ip *hdr, bool flag)
+{
+    if (flag)
+    {
+        hdr->ip_off = htons(ntohs(hdr->ip_off) | IP_MF);
+    }
+    else
+    {
+        hdr->ip_off = htons(ntohs(hdr->ip_off) & ~IP_MF);
+    }
+}
+
+static inline void ipv4_hdr_set_frag_offset(struct ip *hdr, uint16_t frag_offset)
+{
+    hdr->ip_off = htons((frag_offset >> 3) | (ntohs(hdr->ip_off) & ~IP_OFFMASK));
+}
+
+static inline void ipv4_hdr_set_ttl(struct ip *hdr, uint8_t ttl)
+{
+    hdr->ip_ttl = ttl;
+}
+
+static inline void ipv4_hdr_set_protocol(struct ip *hdr, uint8_t protocol)
+{
+    hdr->ip_p = protocol;
+}
+
+static inline void ipv4_hdr_set_checksum(struct ip *hdr, uint16_t checksum)
+{
+    hdr->ip_sum = htons(checksum);
+}
+
+static inline void ipv4_hdr_set_src_addr(struct ip *hdr, uint32_t saddr)
+{
+    hdr->ip_src.s_addr = htonl(saddr);
+}
+
+static inline void ipv4_hdr_set_dst_addr(struct ip *hdr, uint32_t daddr)
+{
+    hdr->ip_dst.s_addr = htonl(daddr);
+}
+
+static inline void ipv4_hdr_set_opt_len(struct ip *hdr, uint8_t opt_len)
+{
+    ipv4_hdr_set_hdr_len(hdr, opt_len + sizeof(struct ip));
+}
+
+// must be called after ipv4_hdr_set_opt_len
+static inline void ipv4_hdr_set_opt_data(struct ip *hdr, const char *opt_data)
+{
+    memcpy((char *)hdr + sizeof(struct ip), opt_data, ipv4_hdr_get_opt_len(hdr));
+}
+
+#ifdef __cpluscplus
+}
+#endif
+
+#endif
diff --git a/src/packet/packet.cpp b/src/packet/packet.cpp
index 756f321..472d1e2 100644
--- a/src/packet/packet.cpp
+++ b/src/packet/packet.cpp
@@ -12,6 +12,7 @@
 #include "packet.h"
 #include "udp_utils.h"
 #include "tcp_utils.h"
+#include "ipv4_utils.h"
 
 #define likely(expr) __builtin_expect((expr), 1)
 #define unlikely(expr) __builtin_expect((expr), 0)
@@ -859,8 +860,8 @@ static inline const char *parse_ipv4(struct packet *handler, const char *data, u
         return data;
     }
     struct ip *hdr = (struct ip *)data;
-    uint8_t next_proto = hdr->ip_p;
-    uint16_t hdr_len = (hdr->ip_hl & 0xf) * 4u;
+    uint8_t next_proto = ipv4_get_proto(hdr);
+    uint16_t hdr_len = ipv4_hdr_get_hdr_len(hdr);
     SET_LAYER(handler, layer, LAYER_TYPE_IPV4, hdr_len, data, len);
 
     // ip fragmented
diff --git a/src/packet/test/CMakeLists.txt b/src/packet/test/CMakeLists.txt
index 4bb05b6..8b130fc 100644
--- a/src/packet/test/CMakeLists.txt
+++ b/src/packet/test/CMakeLists.txt
@@ -11,8 +11,8 @@ target_link_libraries(gtest_udp_utils packet gtest)
 add_executable(gtest_tcp_utils gtest_tcp_utils.cpp)
 target_link_libraries(gtest_tcp_utils packet gtest)
 
-add_executable(gtest_ipv4_helpers gtest_ipv4_helpers.cpp)
-target_link_libraries(gtest_ipv4_helpers packet gtest)
+add_executable(gtest_ipv4_utils gtest_ipv4_utils.cpp)
+target_link_libraries(gtest_ipv4_utils packet gtest)
 
 add_executable(gtest_ipv6_helpers gtest_ipv6_helpers.cpp)
 target_link_libraries(gtest_ipv6_helpers packet gtest)
@@ -24,6 +24,6 @@ include(GoogleTest)
 gtest_discover_tests(gtest_packet)
 gtest_discover_tests(gtest_udp_utils)
 gtest_discover_tests(gtest_tcp_utils)
-gtest_discover_tests(gtest_ipv4_helpers)
+gtest_discover_tests(gtest_ipv4_utils)
 gtest_discover_tests(gtest_ipv6_helpers)
 gtest_discover_tests(gtest_packet_helpers)
\ No newline at end of file
diff --git a/src/packet/test/gtest_ipv4_helpers.cpp b/src/packet/test/gtest_ipv4_helpers.cpp
deleted file mode 100644
index d4dfc56..0000000
--- a/src/packet/test/gtest_ipv4_helpers.cpp
+++ /dev/null
@@ -1,58 +0,0 @@
-#include <gtest/gtest.h>
-
-#include "ipv4_helpers.h"
-
-/*
- * Internet Protocol Version 4, Src: 192.168.36.103, Dst: 192.168.40.137
- *     0100 .... = Version: 4
- *     .... 0101 = Header Length: 20 bytes (5)
- *     Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
- *         0000 00.. = Differentiated Services Codepoint: Default (0)
- *         .... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0)
- *     Total Length: 44
- *     Identification: 0xffff (65535)
- *     001. .... = Flags: 0x1, More fragments
- *         0... .... = Reserved bit: Not set
- *         .0.. .... = Don't fragment: Not set
- *         ..1. .... = More fragments: Set
- *     ...0 0000 0000 0000 = Fragment Offset: 0
- *     Time to Live: 127
- *     Protocol: TCP (6)
- *     Header Checksum: 0x4d8b [correct]
- *     [Header checksum status: Good]
- *     [Calculated Checksum: 0x4d8b]
- *     Source Address: 192.168.36.103
- *     Destination Address: 192.168.40.137
- *     [Reassembled IPv4 in frame: 5]
- * Data (24 bytes)
- */
-
-unsigned char data[] = {0x45, 0x00, 0x00, 0x2c, 0xff, 0xff, 0x20, 0x00, 0x7f, 0x06, 0x4d, 0x8b, 0xc0, 0xa8, 0x24, 0x67, 0xc0, 0xa8, 0x28, 0x89};
-
-TEST(IPV4_HELPERS, TEST)
-{
-    const struct ip *hdr = (struct ip *)data;
-    EXPECT_TRUE(ipv4_hdr_get_version(hdr) == 4);
-    EXPECT_TRUE(ipv4_hdr_get_hl(hdr) == 20);
-    EXPECT_TRUE(ipv4_hdr_get_tos(hdr) == 0);
-    EXPECT_TRUE(ipv4_hdr_get_len(hdr) == 44);
-    EXPECT_TRUE(ipv4_hdr_get_ipid(hdr) == 65535);
-    EXPECT_TRUE(ipv4_hdr_get_flags(hdr) == 1);
-    EXPECT_TRUE(ipv4_hdr_has_flag_rf(hdr) == false);
-    EXPECT_TRUE(ipv4_hdr_has_flag_df(hdr) == false);
-    EXPECT_TRUE(ipv4_hdr_has_flag_mf(hdr) == true);
-    EXPECT_TRUE(ipv4_hdr_get_frag_offset(hdr) == 0);
-    EXPECT_TRUE(ipv4_hdr_get_ttl(hdr) == 127);
-    EXPECT_TRUE(ipv4_hdr_get_protocol(hdr) == 6);
-    EXPECT_TRUE(ipv4_hdr_get_checksum(hdr) == 0x4d8b);
-    EXPECT_TRUE(ipv4_hdr_get_host_order_saddr(hdr) == 0xc0a82467);
-    EXPECT_TRUE(ipv4_hdr_get_host_order_daddr(hdr) == 0xc0a82889);
-    EXPECT_TRUE(ipv4_hdr_get_opt_len(hdr) == 0);
-    EXPECT_TRUE(ipv4_hdr_get_opt_ptr(hdr) == data + 20);
-}
-
-int main(int argc, char **argv)
-{
-    ::testing::InitGoogleTest(&argc, argv);
-    return RUN_ALL_TESTS();
-}
diff --git a/src/packet/test/gtest_ipv4_utils.cpp b/src/packet/test/gtest_ipv4_utils.cpp
new file mode 100644
index 0000000..bd39f88
--- /dev/null
+++ b/src/packet/test/gtest_ipv4_utils.cpp
@@ -0,0 +1,274 @@
+#include <gtest/gtest.h>
+
+#include "ipv4_utils.h"
+
+/******************************************************************************
+ * more fragment
+ ******************************************************************************/
+
+/*
+ * Internet Protocol Version 4, Src: 192.168.36.103, Dst: 192.168.40.137
+ *     0100 .... = Version: 4
+ *     .... 0101 = Header Length: 20 bytes (5)
+ *     Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
+ *         0000 00.. = Differentiated Services Codepoint: Default (0)
+ *         .... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0)
+ *     Total Length: 44
+ *     Identification: 0xffff (65535)
+ *     001. .... = Flags: 0x1, More fragments
+ *         0... .... = Reserved bit: Not set
+ *         .0.. .... = Don't fragment: Not set
+ *         ..1. .... = More fragments: Set
+ *     ...0 0000 0000 0000 = Fragment Offset: 0
+ *     Time to Live: 127
+ *     Protocol: TCP (6)
+ *     Header Checksum: 0x4d8b [correct]
+ *     [Header checksum status: Good]
+ *     [Calculated Checksum: 0x4d8b]
+ *     Source Address: 192.168.36.103
+ *     Destination Address: 192.168.40.137
+ *     [Reassembled IPv4 in frame: 5]
+ * Data (24 bytes)
+ */
+
+unsigned char data1[] = {0x45, 0x00, 0x00, 0x2c, 0xff, 0xff, 0x20, 0x00, 0x7f, 0x06, 0x4d, 0x8b, 0xc0, 0xa8, 0x24, 0x67, 0xc0, 0xa8, 0x28, 0x89};
+
+TEST(IPV4_UTILS, GET1)
+{
+    const struct ip *hdr = (struct ip *)data1;
+    EXPECT_TRUE(ipv4_hdr_get_version(hdr) == 4);
+    EXPECT_TRUE(ipv4_hdr_get_hdr_len(hdr) == 20);
+    EXPECT_TRUE(ipv4_hdr_get_tos(hdr) == 0);
+    EXPECT_TRUE(ipv4_hdr_get_total_len(hdr) == 44);
+    EXPECT_TRUE(ipv4_hdr_get_ipid(hdr) == 65535);
+    EXPECT_TRUE(ipv4_hdr_get_flags(hdr) == 1);
+    EXPECT_TRUE(ipv4_hdr_get_rf_flag(hdr) == false);
+    EXPECT_TRUE(ipv4_hdr_get_df_flag(hdr) == false);
+    EXPECT_TRUE(ipv4_hdr_get_mf_flag(hdr) == true);
+    EXPECT_TRUE(ipv4_hdr_get_frag_offset(hdr) == 0);
+    EXPECT_TRUE(ipv4_hdr_get_ttl(hdr) == 127);
+    EXPECT_TRUE(ipv4_hdr_get_proto(hdr) == 6);
+    EXPECT_TRUE(ipv4_hdr_get_checksum(hdr) == 0x4d8b);
+    EXPECT_TRUE(ipv4_hdr_get_src_addr(hdr) == 0xc0a82467);
+    EXPECT_TRUE(ipv4_hdr_get_dst_addr(hdr) == 0xc0a82889);
+    EXPECT_TRUE(ipv4_hdr_get_opt_len(hdr) == 0);
+    EXPECT_TRUE(ipv4_hdr_get_opt_data(hdr) == data + 20);
+}
+
+TEST(IPV4_UTILS, SET1)
+{
+    char buff[20] = {0};
+
+    struct ip *hdr = (struct ip *)buff;
+    ipv4_hdr_set_version(hdr, 4);
+    ipv4_hdr_set_hdr_len(hdr, 20);
+    ipv4_hdr_set_tos(hdr, 0);
+    ipv4_hdr_set_total_len(hdr, 44);
+    ipv4_hdr_set_ipid(hdr, 65535);
+    ipv4_hdr_set_frag_offset(hdr, 0);
+    ipv4_hdr_set_ttl(hdr, 127);
+    ipv4_hdr_set_protocol(hdr, 6);
+    ipv4_hdr_set_checksum(hdr, 0x4d8b);
+    ipv4_hdr_set_src_addr(hdr, 0xc0a82467);
+    ipv4_hdr_set_dst_addr(hdr, 0xc0a82889);
+    ipv4_hdr_set_opt_len(hdr, 0);
+    ipv4_hdr_set_opt_data(hdr, NULL);
+
+    ipv4_hdr_set_flags(hdr, 1);
+    EXPECT_TRUE(memcmp(buff, data1, 20) == 0);
+
+    ipv4_hdr_set_rf_flag(hdr, false);
+    ipv4_hdr_set_df_flag(hdr, false);
+    ipv4_hdr_set_mf_flag(hdr, true);
+    EXPECT_TRUE(memcmp(buff, data1, 20) == 0);
+}
+
+/******************************************************************************
+ * fragment offset
+ ******************************************************************************/
+
+/*
+ * Frame 5: 60 bytes on wire (480 bits), 60 bytes captured (480 bits)
+ * Ethernet II, Src: Fortinet_cc:87:22 (e8:1c:ba:cc:87:22), Dst: EvocInte_2f:35:b8 (00:22:46:2f:35:b8)
+ * Internet Protocol Version 4, Src: 192.168.36.103, Dst: 192.168.40.137
+ *     0100 .... = Version: 4
+ *     .... 0101 = Header Length: 20 bytes (5)
+ *     Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
+ *         0000 00.. = Differentiated Services Codepoint: Default (0)
+ *         .... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0)
+ *     Total Length: 44
+ *     Identification: 0xffff (65535)
+ *     000. .... = Flags: 0x0
+ *         0... .... = Reserved bit: Not set
+ *         .0.. .... = Don't fragment: Not set
+ *         ..0. .... = More fragments: Not set
+ *     ...0 0000 0000 0011 = Fragment Offset: 24
+ *     Time to Live: 127
+ *     Protocol: TCP (6)
+ *     Header Checksum: 0x6d88 [correct]
+ *     [Header checksum status: Good]
+ *     [Calculated Checksum: 0x6d88]
+ *     Source Address: 192.168.36.103
+ *     Destination Address: 192.168.40.137
+ *     [2 IPv4 Fragments (48 bytes): #4(24), #5(24)]
+ *         [Frame: 4, payload: 0-23 (24 bytes)]
+ *         [Frame: 5, payload: 24-47 (24 bytes)]
+ *         [Fragment count: 2]
+ *         [Reassembled IPv4 length: 48]
+ *         [Reassembled IPv4 data: f4a5270f9107248703d518e75018ff005e9200003132330af4a5270f9107248b03d518e7…]
+ * Transmission Control Protocol, Src Port: 62629, Dst Port: 9999, Seq: 1, Ack: 1, Len: 28
+ * Data (28 bytes)
+ *     Data: 3132330af4a5270f9107248b03d518e75018ff00301600006162630a
+ *     [Length: 28]
+ */
+
+unsigned char data2[] = {0x45, 0x00, 0x00, 0x2c, 0xff, 0xff, 0x00, 0x03, 0x7f, 0x06, 0x6d, 0x88, 0xc0, 0xa8, 0x24, 0x67, 0xc0, 0xa8, 0x28, 0x89};
+
+TEST(IPV4_UTILS, GET2)
+{
+    const struct ip *hdr = (struct ip *)data2;
+    EXPECT_TRUE(ipv4_hdr_get_version(hdr) == 4);
+    EXPECT_TRUE(ipv4_hdr_get_hdr_len(hdr) == 20);
+    EXPECT_TRUE(ipv4_hdr_get_tos(hdr) == 0);
+    EXPECT_TRUE(ipv4_hdr_get_total_len(hdr) == 44);
+    EXPECT_TRUE(ipv4_hdr_get_ipid(hdr) == 65535);
+    EXPECT_TRUE(ipv4_hdr_get_flags(hdr) == 0);
+    EXPECT_TRUE(ipv4_hdr_get_rf_flag(hdr) == false);
+    EXPECT_TRUE(ipv4_hdr_get_df_flag(hdr) == false);
+    EXPECT_TRUE(ipv4_hdr_get_mf_flag(hdr) == false);
+    EXPECT_TRUE(ipv4_hdr_get_frag_offset(hdr) == 24);
+    EXPECT_TRUE(ipv4_hdr_get_ttl(hdr) == 127);
+    EXPECT_TRUE(ipv4_hdr_get_proto(hdr) == 6);
+    EXPECT_TRUE(ipv4_hdr_get_checksum(hdr) == 0x6d88);
+    EXPECT_TRUE(ipv4_hdr_get_src_addr(hdr) == 0xc0a82467);
+    EXPECT_TRUE(ipv4_hdr_get_dst_addr(hdr) == 0xc0a82889);
+    EXPECT_TRUE(ipv4_hdr_get_opt_len(hdr) == 0);
+    EXPECT_TRUE(ipv4_hdr_get_opt_data(hdr) == data + 20);
+}
+
+TEST(IPV4_UTILS, SET2)
+{
+    char buff[20] = {0};
+
+    struct ip *hdr = (struct ip *)buff;
+    ipv4_hdr_set_version(hdr, 4);
+    ipv4_hdr_set_hdr_len(hdr, 20);
+    ipv4_hdr_set_tos(hdr, 0);
+    ipv4_hdr_set_total_len(hdr, 44);
+    ipv4_hdr_set_ipid(hdr, 65535);
+    ipv4_hdr_set_frag_offset(hdr, 24);
+    ipv4_hdr_set_ttl(hdr, 127);
+    ipv4_hdr_set_protocol(hdr, 6);
+    ipv4_hdr_set_checksum(hdr, 0x6d88);
+    ipv4_hdr_set_src_addr(hdr, 0xc0a82467);
+    ipv4_hdr_set_dst_addr(hdr, 0xc0a82889);
+    ipv4_hdr_set_opt_len(hdr, 0);
+    ipv4_hdr_set_opt_data(hdr, NULL);
+
+    ipv4_hdr_set_flags(hdr, 0);
+    EXPECT_TRUE(memcmp(buff, data2, 20) == 0);
+
+    ipv4_hdr_set_rf_flag(hdr, false);
+    ipv4_hdr_set_df_flag(hdr, false);
+    ipv4_hdr_set_mf_flag(hdr, false);
+    EXPECT_TRUE(memcmp(buff, data2, 20) == 0);
+}
+
+/******************************************************************************
+ * options
+ ******************************************************************************/
+
+/*
+ * Internet Protocol Version 4, Src: 127.0.0.1, Dst: 127.0.0.1
+ *     0100 .... = Version: 4
+ *     .... 1111 = Header Length: 60 bytes (15)
+ *     Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
+ *         0000 00.. = Differentiated Services Codepoint: Default (0)
+ *         .... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0)
+ *     Total Length: 124
+ *     Identification: 0x0000 (0)
+ *     010. .... = Flags: 0x2, Don't fragment
+ *         0... .... = Reserved bit: Not set
+ *         .1.. .... = Don't fragment: Set
+ *         ..0. .... = More fragments: Not set
+ *     ...0 0000 0000 0000 = Fragment Offset: 0
+ *     Time to Live: 64
+ *     Protocol: ICMP (1)
+ *     Header Checksum: 0xfd30 [correct]
+ *     [Header checksum status: Good]
+ *     [Calculated Checksum: 0xfd30]
+ *     Source Address: 127.0.0.1
+ *     Destination Address: 127.0.0.1
+ *     Options: (40 bytes), Commercial Security
+ *         IP Option - Commercial Security (40 bytes)
+ *             Type: 134
+ *                 1... .... = Copy on fragmentation: Yes
+ *                 .00. .... = Class: Control (0)
+ *                 ...0 0110 = Number: Commercial IP security option (6)
+ *             Length: 40
+ *             DOI: 1
+ *             Tag Type: Restrictive Category Bitmap (1)
+ *             Sensitivity Level: 1
+ *             Categories: 0,2,4,5,6,239
+ */
+
+unsigned char data3[] = {
+    0x4f, 0x00, 0x00, 0x7c, 0x00, 0x00, 0x40, 0x00, 0x40, 0x01, 0xfd, 0x30, 0x7f, 0x00, 0x00, 0x01, 0x7f, 0x00, 0x00, 0x01, 0x86, 0x28, 0x00, 0x00, 0x00, 0x01,
+    0x01, 0x22, 0x00, 0x01, 0xae, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01};
+
+TEST(IPV4_UTILS, GET3)
+{
+    const struct ip *hdr = (struct ip *)data3;
+    EXPECT_TRUE(ipv4_hdr_get_version(hdr) == 4);
+    EXPECT_TRUE(ipv4_hdr_get_hdr_len(hdr) == 60);
+    EXPECT_TRUE(ipv4_hdr_get_tos(hdr) == 0);
+    EXPECT_TRUE(ipv4_hdr_get_total_len(hdr) == 124);
+    EXPECT_TRUE(ipv4_hdr_get_ipid(hdr) == 0);
+    EXPECT_TRUE(ipv4_hdr_get_flags(hdr) == 2);
+    EXPECT_TRUE(ipv4_hdr_get_rf_flag(hdr) == false);
+    EXPECT_TRUE(ipv4_hdr_get_df_flag(hdr) == true);
+    EXPECT_TRUE(ipv4_hdr_get_mf_flag(hdr) == false);
+    EXPECT_TRUE(ipv4_hdr_get_frag_offset(hdr) == 0);
+    EXPECT_TRUE(ipv4_hdr_get_ttl(hdr) == 64);
+    EXPECT_TRUE(ipv4_hdr_get_proto(hdr) == 1);
+    EXPECT_TRUE(ipv4_hdr_get_checksum(hdr) == 0xfd30);
+    EXPECT_TRUE(ipv4_hdr_get_src_addr(hdr) == 0x7f000001);
+    EXPECT_TRUE(ipv4_hdr_get_dst_addr(hdr) == 0x7f000001);
+    EXPECT_TRUE(ipv4_hdr_get_opt_len(hdr) == 40);
+    EXPECT_TRUE(ipv4_hdr_get_opt_data(hdr) == data + 20);
+}
+
+TEST(IPV4_UTILS, SET3)
+{
+    char buff[60] = {0};
+
+    struct ip *hdr = (struct ip *)buff;
+    ipv4_hdr_set_version(hdr, 4);
+    ipv4_hdr_set_hdr_len(hdr, 60);
+    ipv4_hdr_set_tos(hdr, 0);
+    ipv4_hdr_set_total_len(hdr, 124);
+    ipv4_hdr_set_ipid(hdr, 0);
+    ipv4_hdr_set_frag_offset(hdr, 0);
+    ipv4_hdr_set_ttl(hdr, 64);
+    ipv4_hdr_set_protocol(hdr, 1);
+    ipv4_hdr_set_checksum(hdr, 0xfd30);
+    ipv4_hdr_set_src_addr(hdr, 0x7f000001);
+    ipv4_hdr_set_dst_addr(hdr, 0x7f000001);
+    ipv4_hdr_set_opt_len(hdr, 40);
+    ipv4_hdr_set_opt_data(hdr, data3 + 20);
+
+    ipv4_hdr_set_flags(hdr, 2);
+    EXPECT_TRUE(memcmp(buff, data3, 60) == 0);
+
+    ipv4_hdr_set_rf_flag(hdr, false);
+    ipv4_hdr_set_df_flag(hdr, true);
+    ipv4_hdr_set_mf_flag(hdr, false);
+    EXPECT_TRUE(memcmp(buff, data3, 60) == 0);
+}
+
+int main(int argc, char **argv)
+{
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}
diff --git a/src/session/test/gtest_filter_tcp_dupkt.cpp b/src/session/test/gtest_filter_tcp_dupkt.cpp
index c909de2..ef4b5c6 100644
--- a/src/session/test/gtest_filter_tcp_dupkt.cpp
+++ b/src/session/test/gtest_filter_tcp_dupkt.cpp
@@ -36,8 +36,8 @@ TEST(TCP_DUPKT_FILTER_ENABLE, SYN_DUP)
     packet_parse(&pkt, (const char *)tcp_pkt_c2s_syn_retransmission, sizeof(tcp_pkt1_c2s_syn));
     const struct layer_record *ipv4_layer = packet_get_innermost_layer(&pkt, LAYER_TYPE_IPV4);
     EXPECT_TRUE(ipv4_layer);
-    const struct ip *hdr = (const struct ip *)ipv4_layer->hdr_ptr;
-    ipv4_hdr_set_ipid((struct ip *)hdr, 0x1234);
+    struct ip *hdr = (struct ip *)ipv4_layer->hdr_ptr;
+    ipv4_hdr_set_ipid(hdr, 0x1234);
     printf("<= packet parse\n\n");
     sess = session_manager_update_session(mgr, &pkt);
     EXPECT_TRUE(sess);
@@ -88,8 +88,8 @@ TEST(TCP_DUPKT_FILTER_ENABLE, S2C_DUP)
     packet_parse(&pkt, (const char *)tcp_pkt_s2c_synack_retransmission, sizeof(tcp_pkt2_s2c_syn_ack));
     const struct layer_record *ipv4_layer = packet_get_innermost_layer(&pkt, LAYER_TYPE_IPV4);
     EXPECT_TRUE(ipv4_layer);
-    const struct ip *hdr = (const struct ip *)ipv4_layer->hdr_ptr;
-    ipv4_hdr_set_ipid((struct ip *)hdr, 0x1234);
+    struct ip *hdr = (struct ip *)ipv4_layer->hdr_ptr;
+    ipv4_hdr_set_ipid(hdr, 0x1234);
     printf("<= packet parse\n\n");
     sess = session_manager_update_session(mgr, &pkt);
     EXPECT_TRUE(sess);
@@ -111,7 +111,7 @@ TEST(TCP_DUPKT_FILTER_ENABLE, SKIP_FILTER)
     struct session *sess = NULL;
     struct session_manager *mgr = NULL;
     const struct layer_record *ipv4_layer;
-    const struct ip *hdr;
+    struct ip *hdr;
     char tcp_pkt_c2s_syn_retransmission[1500] = {0};
 
     timestamp_update();
@@ -134,8 +134,8 @@ TEST(TCP_DUPKT_FILTER_ENABLE, SKIP_FILTER)
     packet_parse(&pkt, (const char *)tcp_pkt_c2s_syn_retransmission, sizeof(tcp_pkt1_c2s_syn));
     ipv4_layer = packet_get_innermost_layer(&pkt, LAYER_TYPE_IPV4);
     EXPECT_TRUE(ipv4_layer);
-    hdr = (const struct ip *)ipv4_layer->hdr_ptr;
-    ipv4_hdr_set_ipid((struct ip *)hdr, 0x1234);
+    hdr = (struct ip *)ipv4_layer->hdr_ptr;
+    ipv4_hdr_set_ipid(hdr, 0x1234);
     printf("<= packet parse\n\n");
     sess = session_manager_update_session(mgr, &pkt);
     EXPECT_TRUE(sess);
@@ -148,8 +148,8 @@ TEST(TCP_DUPKT_FILTER_ENABLE, SKIP_FILTER)
     packet_parse(&pkt, (const char *)tcp_pkt_c2s_syn_retransmission, sizeof(tcp_pkt1_c2s_syn));
     ipv4_layer = packet_get_innermost_layer(&pkt, LAYER_TYPE_IPV4);
     EXPECT_TRUE(ipv4_layer);
-    hdr = (const struct ip *)ipv4_layer->hdr_ptr;
-    ipv4_hdr_set_ipid((struct ip *)hdr, 0x1235);
+    hdr = (struct ip *)ipv4_layer->hdr_ptr;
+    ipv4_hdr_set_ipid(hdr, 0x1235);
     printf("<= packet parse\n\n");
     sess = session_manager_update_session(mgr, &pkt);
     EXPECT_TRUE(sess);
@@ -211,8 +211,8 @@ TEST(TCP_DUPKT_FILTER_DISABLE, C2S_DUPKT)
     packet_parse(&pkt, (const char *)tcp_pkt_c2s_syn_retransmission, sizeof(tcp_pkt1_c2s_syn));
     const struct layer_record *ipv4_layer = packet_get_innermost_layer(&pkt, LAYER_TYPE_IPV4);
     EXPECT_TRUE(ipv4_layer);
-    const struct ip *hdr = (const struct ip *)ipv4_layer->hdr_ptr;
-    ipv4_hdr_set_ipid((struct ip *)hdr, 0x1234);
+    struct ip *hdr = (struct ip *)ipv4_layer->hdr_ptr;
+    ipv4_hdr_set_ipid(hdr, 0x1234);
     printf("<= packet parse\n\n");
     sess = session_manager_update_session(mgr, &pkt);
     EXPECT_TRUE(sess);
@@ -266,8 +266,8 @@ TEST(TCP_DUPKT_FILTER_DISABLE, S2C_DUP)
     packet_parse(&pkt, (const char *)tcp_pkt_s2c_synack_retransmission, sizeof(tcp_pkt2_s2c_syn_ack));
     const struct layer_record *ipv4_layer = packet_get_innermost_layer(&pkt, LAYER_TYPE_IPV4);
     EXPECT_TRUE(ipv4_layer);
-    const struct ip *hdr = (const struct ip *)ipv4_layer->hdr_ptr;
-    ipv4_hdr_set_ipid((struct ip *)hdr, 0x1234);
+    struct ip *hdr = (struct ip *)ipv4_layer->hdr_ptr;
+    ipv4_hdr_set_ipid(hdr, 0x1234);
     printf("<= packet parse\n\n");
     sess = session_manager_update_session(mgr, &pkt);
     EXPECT_TRUE(sess);
diff --git a/src/session/test/gtest_overload_evict_tcp_sess.cpp b/src/session/test/gtest_overload_evict_tcp_sess.cpp
index dea8abc..c3017ec 100644
--- a/src/session/test/gtest_overload_evict_tcp_sess.cpp
+++ b/src/session/test/gtest_overload_evict_tcp_sess.cpp
@@ -4,8 +4,8 @@ static void overwrite_ipv4_saddr(struct packet *pkt, uint32_t saddr)
 {
     const struct layer_record *ipv4_layer = packet_get_innermost_layer(pkt, LAYER_TYPE_IPV4);
     EXPECT_TRUE(ipv4_layer);
-    const struct ip *hdr = (const struct ip *)ipv4_layer->hdr_ptr;
-    ipv4_hdr_set_host_order_saddr((struct ip *)hdr, saddr);
+    struct ip *hdr = (struct ip *)ipv4_layer->hdr_ptr;
+    ipv4_hdr_set_src_addr(hdr, saddr);
 }
 
 #if 1
diff --git a/src/session/test/gtest_overload_evict_udp_sess.cpp b/src/session/test/gtest_overload_evict_udp_sess.cpp
index b57f6f8..2280324 100644
--- a/src/session/test/gtest_overload_evict_udp_sess.cpp
+++ b/src/session/test/gtest_overload_evict_udp_sess.cpp
@@ -4,8 +4,8 @@ static void overwrite_ipv4_saddr(struct packet *pkt, uint32_t saddr)
 {
     const struct layer_record *ipv4_layer = packet_get_innermost_layer(pkt, LAYER_TYPE_IPV4);
     EXPECT_TRUE(ipv4_layer);
-    const struct ip *hdr = (const struct ip *)ipv4_layer->hdr_ptr;
-    ipv4_hdr_set_host_order_saddr((struct ip *)hdr, saddr);
+    struct ip *hdr = (struct ip *)ipv4_layer->hdr_ptr;
+    ipv4_hdr_set_src_addr(hdr, saddr);
 }
 
 #if 1
diff --git a/src/session/test/gtest_state_tcp_init_to_opening.cpp b/src/session/test/gtest_state_tcp_init_to_opening.cpp
index c126657..4e6bcd6 100644
--- a/src/session/test/gtest_state_tcp_init_to_opening.cpp
+++ b/src/session/test/gtest_state_tcp_init_to_opening.cpp
@@ -387,8 +387,8 @@ TEST(TCP_INIT_TO_OPENING, BY_SYN_RETRANSMISSION)
     packet_parse(&pkt, (const char *)tcp_pkt_c2s_syn_retransmission, sizeof(tcp_pkt1_c2s_syn));
     const struct layer_record *ipv4_layer = packet_get_innermost_layer(&pkt, LAYER_TYPE_IPV4);
     EXPECT_TRUE(ipv4_layer);
-    const struct ip *hdr = (const struct ip *)ipv4_layer->hdr_ptr;
-    ipv4_hdr_set_ipid((struct ip *)hdr, 0x1234);
+    struct ip *hdr = (struct ip *)ipv4_layer->hdr_ptr;
+    ipv4_hdr_set_ipid(hdr, 0x1234);
     printf("<= packet parse\n\n");
     sess = session_manager_update_session(mgr, &pkt);
     EXPECT_TRUE(sess);
@@ -485,8 +485,8 @@ TEST(TCP_INIT_TO_OPENING, BY_SYNACK_RETRANSMISSION)
     packet_parse(&pkt, (const char *)tcp_pkt_s2c_synack_retransmission, sizeof(tcp_pkt2_s2c_syn_ack));
     const struct layer_record *ipv4_layer = packet_get_innermost_layer(&pkt, LAYER_TYPE_IPV4);
     EXPECT_TRUE(ipv4_layer);
-    const struct ip *hdr = (const struct ip *)ipv4_layer->hdr_ptr;
-    ipv4_hdr_set_ipid((struct ip *)hdr, 0x1234);
+    struct ip *hdr = (struct ip *)ipv4_layer->hdr_ptr;
+    ipv4_hdr_set_ipid(hdr, 0x1234);
     printf("<= packet parse\n\n");
     sess = session_manager_update_session(mgr, &pkt);
     EXPECT_TRUE(sess);