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-rw-r--r--hw/net/net_rx_pkt.c473
-rw-r--r--hw/net/net_rx_pkt.h193
-rw-r--r--hw/net/net_tx_pkt.c204
-rw-r--r--hw/net/net_tx_pkt.h60
4 files changed, 813 insertions, 117 deletions
diff --git a/hw/net/net_rx_pkt.c b/hw/net/net_rx_pkt.c
index 8a4f29fe04..1019b50c18 100644
--- a/hw/net/net_rx_pkt.c
+++ b/hw/net/net_rx_pkt.c
@@ -16,24 +16,16 @@
  */
 
 #include "qemu/osdep.h"
+#include "trace.h"
 #include "net_rx_pkt.h"
-#include "net/eth.h"
-#include "qemu-common.h"
-#include "qemu/iov.h"
 #include "net/checksum.h"
 #include "net/tap.h"
 
-/*
- * RX packet may contain up to 2 fragments - rebuilt eth header
- * in case of VLAN tag stripping
- * and payload received from QEMU - in any case
- */
-#define NET_MAX_RX_PACKET_FRAGMENTS (2)
-
 struct NetRxPkt {
     struct virtio_net_hdr virt_hdr;
-    uint8_t ehdr_buf[ETH_MAX_L2_HDR_LEN];
-    struct iovec vec[NET_MAX_RX_PACKET_FRAGMENTS];
+    uint8_t ehdr_buf[sizeof(struct eth_header)];
+    struct iovec *vec;
+    uint16_t vec_len_total;
     uint16_t vec_len;
     uint32_t tot_len;
     uint16_t tci;
@@ -46,17 +38,31 @@ struct NetRxPkt {
     bool isip6;
     bool isudp;
     bool istcp;
+
+    size_t l3hdr_off;
+    size_t l4hdr_off;
+    size_t l5hdr_off;
+
+    eth_ip6_hdr_info ip6hdr_info;
+    eth_ip4_hdr_info ip4hdr_info;
+    eth_l4_hdr_info  l4hdr_info;
 };
 
 void net_rx_pkt_init(struct NetRxPkt **pkt, bool has_virt_hdr)
 {
     struct NetRxPkt *p = g_malloc0(sizeof *p);
     p->has_virt_hdr = has_virt_hdr;
+    p->vec = NULL;
+    p->vec_len_total = 0;
     *pkt = p;
 }
 
 void net_rx_pkt_uninit(struct NetRxPkt *pkt)
 {
+    if (pkt->vec_len_total != 0) {
+        g_free(pkt->vec);
+    }
+
     g_free(pkt);
 }
 
@@ -66,33 +72,88 @@ struct virtio_net_hdr *net_rx_pkt_get_vhdr(struct NetRxPkt *pkt)
     return &pkt->virt_hdr;
 }
 
-void net_rx_pkt_attach_data(struct NetRxPkt *pkt, const void *data,
-                               size_t len, bool strip_vlan)
+static inline void
+net_rx_pkt_iovec_realloc(struct NetRxPkt *pkt,
+                            int new_iov_len)
+{
+    if (pkt->vec_len_total < new_iov_len) {
+        g_free(pkt->vec);
+        pkt->vec = g_malloc(sizeof(*pkt->vec) * new_iov_len);
+        pkt->vec_len_total = new_iov_len;
+    }
+}
+
+static void
+net_rx_pkt_pull_data(struct NetRxPkt *pkt,
+                        const struct iovec *iov, int iovcnt,
+                        size_t ploff)
+{
+    if (pkt->vlan_stripped) {
+        net_rx_pkt_iovec_realloc(pkt, iovcnt + 1);
+
+        pkt->vec[0].iov_base = pkt->ehdr_buf;
+        pkt->vec[0].iov_len = sizeof(pkt->ehdr_buf);
+
+        pkt->tot_len =
+            iov_size(iov, iovcnt) - ploff + sizeof(struct eth_header);
+
+        pkt->vec_len = iov_copy(pkt->vec + 1, pkt->vec_len_total - 1,
+                                iov, iovcnt, ploff, pkt->tot_len);
+    } else {
+        net_rx_pkt_iovec_realloc(pkt, iovcnt);
+
+        pkt->tot_len = iov_size(iov, iovcnt) - ploff;
+        pkt->vec_len = iov_copy(pkt->vec, pkt->vec_len_total,
+                                iov, iovcnt, ploff, pkt->tot_len);
+    }
+
+    eth_get_protocols(pkt->vec, pkt->vec_len, &pkt->isip4, &pkt->isip6,
+                      &pkt->isudp, &pkt->istcp,
+                      &pkt->l3hdr_off, &pkt->l4hdr_off, &pkt->l5hdr_off,
+                      &pkt->ip6hdr_info, &pkt->ip4hdr_info, &pkt->l4hdr_info);
+
+    trace_net_rx_pkt_parsed(pkt->isip4, pkt->isip6, pkt->isudp, pkt->istcp,
+                            pkt->l3hdr_off, pkt->l4hdr_off, pkt->l5hdr_off);
+}
+
+void net_rx_pkt_attach_iovec(struct NetRxPkt *pkt,
+                                const struct iovec *iov, int iovcnt,
+                                size_t iovoff, bool strip_vlan)
 {
     uint16_t tci = 0;
-    uint16_t ploff;
+    uint16_t ploff = iovoff;
     assert(pkt);
     pkt->vlan_stripped = false;
 
     if (strip_vlan) {
-        pkt->vlan_stripped = eth_strip_vlan(data, pkt->ehdr_buf, &ploff, &tci);
+        pkt->vlan_stripped = eth_strip_vlan(iov, iovcnt, iovoff, pkt->ehdr_buf,
+                                            &ploff, &tci);
     }
 
-    if (pkt->vlan_stripped) {
-        pkt->vec[0].iov_base = pkt->ehdr_buf;
-        pkt->vec[0].iov_len = ploff - sizeof(struct vlan_header);
-        pkt->vec[1].iov_base = (uint8_t *) data + ploff;
-        pkt->vec[1].iov_len = len - ploff;
-        pkt->vec_len = 2;
-        pkt->tot_len = len - ploff + sizeof(struct eth_header);
-    } else {
-        pkt->vec[0].iov_base = (void *)data;
-        pkt->vec[0].iov_len = len;
-        pkt->vec_len = 1;
-        pkt->tot_len = len;
+    pkt->tci = tci;
+
+    net_rx_pkt_pull_data(pkt, iov, iovcnt, ploff);
+}
+
+void net_rx_pkt_attach_iovec_ex(struct NetRxPkt *pkt,
+                                const struct iovec *iov, int iovcnt,
+                                size_t iovoff, bool strip_vlan,
+                                uint16_t vet)
+{
+    uint16_t tci = 0;
+    uint16_t ploff = iovoff;
+    assert(pkt);
+    pkt->vlan_stripped = false;
+
+    if (strip_vlan) {
+        pkt->vlan_stripped = eth_strip_vlan_ex(iov, iovcnt, iovoff, vet,
+                                               pkt->ehdr_buf,
+                                               &ploff, &tci);
     }
 
     pkt->tci = tci;
+
+    net_rx_pkt_pull_data(pkt, iov, iovcnt, ploff);
 }
 
 void net_rx_pkt_dump(struct NetRxPkt *pkt)
@@ -132,10 +193,17 @@ size_t net_rx_pkt_get_total_len(struct NetRxPkt *pkt)
 void net_rx_pkt_set_protocols(struct NetRxPkt *pkt, const void *data,
                               size_t len)
 {
+    const struct iovec iov = {
+        .iov_base = (void *)data,
+        .iov_len = len
+    };
+
     assert(pkt);
 
-    eth_get_protocols(data, len, &pkt->isip4, &pkt->isip6,
-        &pkt->isudp, &pkt->istcp);
+    eth_get_protocols(&iov, 1, &pkt->isip4, &pkt->isip6,
+                      &pkt->isudp, &pkt->istcp,
+                      &pkt->l3hdr_off, &pkt->l4hdr_off, &pkt->l5hdr_off,
+                      &pkt->ip6hdr_info, &pkt->ip4hdr_info, &pkt->l4hdr_info);
 }
 
 void net_rx_pkt_get_protocols(struct NetRxPkt *pkt,
@@ -150,6 +218,180 @@ void net_rx_pkt_get_protocols(struct NetRxPkt *pkt,
     *istcp = pkt->istcp;
 }
 
+size_t net_rx_pkt_get_l3_hdr_offset(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+    return pkt->l3hdr_off;
+}
+
+size_t net_rx_pkt_get_l4_hdr_offset(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+    return pkt->l4hdr_off;
+}
+
+size_t net_rx_pkt_get_l5_hdr_offset(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+    return pkt->l5hdr_off;
+}
+
+eth_ip6_hdr_info *net_rx_pkt_get_ip6_info(struct NetRxPkt *pkt)
+{
+    return &pkt->ip6hdr_info;
+}
+
+eth_ip4_hdr_info *net_rx_pkt_get_ip4_info(struct NetRxPkt *pkt)
+{
+    return &pkt->ip4hdr_info;
+}
+
+eth_l4_hdr_info *net_rx_pkt_get_l4_info(struct NetRxPkt *pkt)
+{
+    return &pkt->l4hdr_info;
+}
+
+static inline void
+_net_rx_rss_add_chunk(uint8_t *rss_input, size_t *bytes_written,
+                      void *ptr, size_t size)
+{
+    memcpy(&rss_input[*bytes_written], ptr, size);
+    trace_net_rx_pkt_rss_add_chunk(ptr, size, *bytes_written);
+    *bytes_written += size;
+}
+
+static inline void
+_net_rx_rss_prepare_ip4(uint8_t *rss_input,
+                        struct NetRxPkt *pkt,
+                        size_t *bytes_written)
+{
+    struct ip_header *ip4_hdr = &pkt->ip4hdr_info.ip4_hdr;
+
+    _net_rx_rss_add_chunk(rss_input, bytes_written,
+                          &ip4_hdr->ip_src, sizeof(uint32_t));
+
+    _net_rx_rss_add_chunk(rss_input, bytes_written,
+                          &ip4_hdr->ip_dst, sizeof(uint32_t));
+}
+
+static inline void
+_net_rx_rss_prepare_ip6(uint8_t *rss_input,
+                        struct NetRxPkt *pkt,
+                        bool ipv6ex, size_t *bytes_written)
+{
+    eth_ip6_hdr_info *ip6info = &pkt->ip6hdr_info;
+
+    _net_rx_rss_add_chunk(rss_input, bytes_written,
+           (ipv6ex && ip6info->rss_ex_src_valid) ? &ip6info->rss_ex_src
+                                                 : &ip6info->ip6_hdr.ip6_src,
+           sizeof(struct in6_address));
+
+    _net_rx_rss_add_chunk(rss_input, bytes_written,
+           (ipv6ex && ip6info->rss_ex_dst_valid) ? &ip6info->rss_ex_dst
+                                                 : &ip6info->ip6_hdr.ip6_dst,
+           sizeof(struct in6_address));
+}
+
+static inline void
+_net_rx_rss_prepare_tcp(uint8_t *rss_input,
+                        struct NetRxPkt *pkt,
+                        size_t *bytes_written)
+{
+    struct tcp_header *tcphdr = &pkt->l4hdr_info.hdr.tcp;
+
+    _net_rx_rss_add_chunk(rss_input, bytes_written,
+                          &tcphdr->th_sport, sizeof(uint16_t));
+
+    _net_rx_rss_add_chunk(rss_input, bytes_written,
+                          &tcphdr->th_dport, sizeof(uint16_t));
+}
+
+uint32_t
+net_rx_pkt_calc_rss_hash(struct NetRxPkt *pkt,
+                         NetRxPktRssType type,
+                         uint8_t *key)
+{
+    uint8_t rss_input[36];
+    size_t rss_length = 0;
+    uint32_t rss_hash = 0;
+    net_toeplitz_key key_data;
+
+    switch (type) {
+    case NetPktRssIpV4:
+        assert(pkt->isip4);
+        trace_net_rx_pkt_rss_ip4();
+        _net_rx_rss_prepare_ip4(&rss_input[0], pkt, &rss_length);
+        break;
+    case NetPktRssIpV4Tcp:
+        assert(pkt->isip4);
+        assert(pkt->istcp);
+        trace_net_rx_pkt_rss_ip4_tcp();
+        _net_rx_rss_prepare_ip4(&rss_input[0], pkt, &rss_length);
+        _net_rx_rss_prepare_tcp(&rss_input[0], pkt, &rss_length);
+        break;
+    case NetPktRssIpV6Tcp:
+        assert(pkt->isip6);
+        assert(pkt->istcp);
+        trace_net_rx_pkt_rss_ip6_tcp();
+        _net_rx_rss_prepare_ip6(&rss_input[0], pkt, true, &rss_length);
+        _net_rx_rss_prepare_tcp(&rss_input[0], pkt, &rss_length);
+        break;
+    case NetPktRssIpV6:
+        assert(pkt->isip6);
+        trace_net_rx_pkt_rss_ip6();
+        _net_rx_rss_prepare_ip6(&rss_input[0], pkt, false, &rss_length);
+        break;
+    case NetPktRssIpV6Ex:
+        assert(pkt->isip6);
+        trace_net_rx_pkt_rss_ip6_ex();
+        _net_rx_rss_prepare_ip6(&rss_input[0], pkt, true, &rss_length);
+        break;
+    default:
+        assert(false);
+        break;
+    }
+
+    net_toeplitz_key_init(&key_data, key);
+    net_toeplitz_add(&rss_hash, rss_input, rss_length, &key_data);
+
+    trace_net_rx_pkt_rss_hash(rss_length, rss_hash);
+
+    return rss_hash;
+}
+
+uint16_t net_rx_pkt_get_ip_id(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+
+    if (pkt->isip4) {
+        return be16_to_cpu(pkt->ip4hdr_info.ip4_hdr.ip_id);
+    }
+
+    return 0;
+}
+
+bool net_rx_pkt_is_tcp_ack(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+
+    if (pkt->istcp) {
+        return TCP_HEADER_FLAGS(&pkt->l4hdr_info.hdr.tcp) & TCP_FLAG_ACK;
+    }
+
+    return false;
+}
+
+bool net_rx_pkt_has_tcp_data(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+
+    if (pkt->istcp) {
+        return pkt->l4hdr_info.has_tcp_data;
+    }
+
+    return false;
+}
+
 struct iovec *net_rx_pkt_get_iovec(struct NetRxPkt *pkt)
 {
     assert(pkt);
@@ -157,6 +399,13 @@ struct iovec *net_rx_pkt_get_iovec(struct NetRxPkt *pkt)
     return pkt->vec;
 }
 
+uint16_t net_rx_pkt_get_iovec_len(struct NetRxPkt *pkt)
+{
+    assert(pkt);
+
+    return pkt->vec_len;
+}
+
 void net_rx_pkt_set_vhdr(struct NetRxPkt *pkt,
                             struct virtio_net_hdr *vhdr)
 {
@@ -165,6 +414,14 @@ void net_rx_pkt_set_vhdr(struct NetRxPkt *pkt,
     memcpy(&pkt->virt_hdr, vhdr, sizeof pkt->virt_hdr);
 }
 
+void net_rx_pkt_set_vhdr_iovec(struct NetRxPkt *pkt,
+    const struct iovec *iov, int iovcnt)
+{
+    assert(pkt);
+
+    iov_to_buf(iov, iovcnt, 0, &pkt->virt_hdr, sizeof pkt->virt_hdr);
+}
+
 bool net_rx_pkt_is_vlan_stripped(struct NetRxPkt *pkt)
 {
     assert(pkt);
@@ -185,3 +442,159 @@ uint16_t net_rx_pkt_get_vlan_tag(struct NetRxPkt *pkt)
 
     return pkt->tci;
 }
+
+bool net_rx_pkt_validate_l3_csum(struct NetRxPkt *pkt, bool *csum_valid)
+{
+    uint32_t cntr;
+    uint16_t csum;
+    uint32_t csl;
+
+    trace_net_rx_pkt_l3_csum_validate_entry();
+
+    if (!pkt->isip4) {
+        trace_net_rx_pkt_l3_csum_validate_not_ip4();
+        return false;
+    }
+
+    csl = pkt->l4hdr_off - pkt->l3hdr_off;
+
+    cntr = net_checksum_add_iov(pkt->vec, pkt->vec_len,
+                                pkt->l3hdr_off,
+                                csl, 0);
+
+    csum = net_checksum_finish(cntr);
+
+    *csum_valid = (csum == 0);
+
+    trace_net_rx_pkt_l3_csum_validate_csum(pkt->l3hdr_off, csl,
+                                           cntr, csum, *csum_valid);
+
+    return true;
+}
+
+static uint16_t
+_net_rx_pkt_calc_l4_csum(struct NetRxPkt *pkt)
+{
+    uint32_t cntr;
+    uint16_t csum;
+    uint16_t csl;
+    uint32_t cso;
+
+    trace_net_rx_pkt_l4_csum_calc_entry();
+
+    if (pkt->isip4) {
+        if (pkt->isudp) {
+            csl = be16_to_cpu(pkt->l4hdr_info.hdr.udp.uh_ulen);
+            trace_net_rx_pkt_l4_csum_calc_ip4_udp();
+        } else {
+            csl = be16_to_cpu(pkt->ip4hdr_info.ip4_hdr.ip_len) -
+                  IP_HDR_GET_LEN(&pkt->ip4hdr_info.ip4_hdr);
+            trace_net_rx_pkt_l4_csum_calc_ip4_tcp();
+        }
+
+        cntr = eth_calc_ip4_pseudo_hdr_csum(&pkt->ip4hdr_info.ip4_hdr,
+                                            csl, &cso);
+        trace_net_rx_pkt_l4_csum_calc_ph_csum(cntr, csl);
+    } else {
+        if (pkt->isudp) {
+            csl = be16_to_cpu(pkt->l4hdr_info.hdr.udp.uh_ulen);
+            trace_net_rx_pkt_l4_csum_calc_ip6_udp();
+        } else {
+            struct ip6_header *ip6hdr = &pkt->ip6hdr_info.ip6_hdr;
+            size_t full_ip6hdr_len = pkt->l4hdr_off - pkt->l3hdr_off;
+            size_t ip6opts_len = full_ip6hdr_len - sizeof(struct ip6_header);
+
+            csl = be16_to_cpu(ip6hdr->ip6_ctlun.ip6_un1.ip6_un1_plen) -
+                  ip6opts_len;
+            trace_net_rx_pkt_l4_csum_calc_ip6_tcp();
+        }
+
+        cntr = eth_calc_ip6_pseudo_hdr_csum(&pkt->ip6hdr_info.ip6_hdr, csl,
+                                            pkt->ip6hdr_info.l4proto, &cso);
+        trace_net_rx_pkt_l4_csum_calc_ph_csum(cntr, csl);
+    }
+
+    cntr += net_checksum_add_iov(pkt->vec, pkt->vec_len,
+                                 pkt->l4hdr_off, csl, cso);
+
+    csum = net_checksum_finish(cntr);
+
+    trace_net_rx_pkt_l4_csum_calc_csum(pkt->l4hdr_off, csl, cntr, csum);
+
+    return csum;
+}
+
+bool net_rx_pkt_validate_l4_csum(struct NetRxPkt *pkt, bool *csum_valid)
+{
+    uint16_t csum;
+
+    trace_net_rx_pkt_l4_csum_validate_entry();
+
+    if (!pkt->istcp && !pkt->isudp) {
+        trace_net_rx_pkt_l4_csum_validate_not_xxp();
+        return false;
+    }
+
+    if (pkt->isudp && (pkt->l4hdr_info.hdr.udp.uh_sum == 0)) {
+        trace_net_rx_pkt_l4_csum_validate_udp_with_no_checksum();
+        return false;
+    }
+
+    if (pkt->isip4 && pkt->ip4hdr_info.fragment) {
+        trace_net_rx_pkt_l4_csum_validate_ip4_fragment();
+        return false;
+    }
+
+    csum = _net_rx_pkt_calc_l4_csum(pkt);
+
+    *csum_valid = ((csum == 0) || (csum == 0xFFFF));
+
+    trace_net_rx_pkt_l4_csum_validate_csum(*csum_valid);
+
+    return true;
+}
+
+bool net_rx_pkt_fix_l4_csum(struct NetRxPkt *pkt)
+{
+    uint16_t csum = 0;
+    uint32_t l4_cso;
+
+    trace_net_rx_pkt_l4_csum_fix_entry();
+
+    if (pkt->istcp) {
+        l4_cso = offsetof(struct tcp_header, th_sum);
+        trace_net_rx_pkt_l4_csum_fix_tcp(l4_cso);
+    } else if (pkt->isudp) {
+        if (pkt->l4hdr_info.hdr.udp.uh_sum == 0) {
+            trace_net_rx_pkt_l4_csum_fix_udp_with_no_checksum();
+            return false;
+        }
+        l4_cso = offsetof(struct udp_header, uh_sum);
+        trace_net_rx_pkt_l4_csum_fix_udp(l4_cso);
+    } else {
+        trace_net_rx_pkt_l4_csum_fix_not_xxp();
+        return false;
+    }
+
+    if (pkt->isip4 && pkt->ip4hdr_info.fragment) {
+            trace_net_rx_pkt_l4_csum_fix_ip4_fragment();
+            return false;
+    }
+
+    /* Set zero to checksum word */
+    iov_from_buf(pkt->vec, pkt->vec_len,
+                 pkt->l4hdr_off + l4_cso,
+                 &csum, sizeof(csum));
+
+    /* Calculate L4 checksum */
+    csum = cpu_to_be16(_net_rx_pkt_calc_l4_csum(pkt));
+
+    /* Set calculated checksum to checksum word */
+    iov_from_buf(pkt->vec, pkt->vec_len,
+                 pkt->l4hdr_off + l4_cso,
+                 &csum, sizeof(csum));
+
+    trace_net_rx_pkt_l4_csum_fix_csum(pkt->l4hdr_off + l4_cso, csum);
+
+    return true;
+}
diff --git a/hw/net/net_rx_pkt.h b/hw/net/net_rx_pkt.h
index 897330a157..7adf0fad51 100644
--- a/hw/net/net_rx_pkt.h
+++ b/hw/net/net_rx_pkt.h
@@ -78,6 +78,103 @@ void net_rx_pkt_get_protocols(struct NetRxPkt *pkt,
                                  bool *isudp, bool *istcp);
 
 /**
+* fetches L3 header offset
+*
+* @pkt:            packet
+*
+*/
+size_t net_rx_pkt_get_l3_hdr_offset(struct NetRxPkt *pkt);
+
+/**
+* fetches L4 header offset
+*
+* @pkt:            packet
+*
+*/
+size_t net_rx_pkt_get_l4_hdr_offset(struct NetRxPkt *pkt);
+
+/**
+* fetches L5 header offset
+*
+* @pkt:            packet
+*
+*/
+size_t net_rx_pkt_get_l5_hdr_offset(struct NetRxPkt *pkt);
+
+/**
+ * fetches IP6 header analysis results
+ *
+ * Return:  pointer to analysis results structure which is stored in internal
+ *          packet area.
+ *
+ */
+eth_ip6_hdr_info *net_rx_pkt_get_ip6_info(struct NetRxPkt *pkt);
+
+/**
+ * fetches IP4 header analysis results
+ *
+ * Return:  pointer to analysis results structure which is stored in internal
+ *          packet area.
+ *
+ */
+eth_ip4_hdr_info *net_rx_pkt_get_ip4_info(struct NetRxPkt *pkt);
+
+/**
+ * fetches L4 header analysis results
+ *
+ * Return:  pointer to analysis results structure which is stored in internal
+ *          packet area.
+ *
+ */
+eth_l4_hdr_info *net_rx_pkt_get_l4_info(struct NetRxPkt *pkt);
+
+typedef enum {
+    NetPktRssIpV4,
+    NetPktRssIpV4Tcp,
+    NetPktRssIpV6Tcp,
+    NetPktRssIpV6,
+    NetPktRssIpV6Ex
+} NetRxPktRssType;
+
+/**
+* calculates RSS hash for packet
+*
+* @pkt:            packet
+* @type:           RSS hash type
+*
+* Return:  Toeplitz RSS hash.
+*
+*/
+uint32_t
+net_rx_pkt_calc_rss_hash(struct NetRxPkt *pkt,
+                         NetRxPktRssType type,
+                         uint8_t *key);
+
+/**
+* fetches IP identification for the packet
+*
+* @pkt:            packet
+*
+*/
+uint16_t net_rx_pkt_get_ip_id(struct NetRxPkt *pkt);
+
+/**
+* check if given packet is a TCP ACK packet
+*
+* @pkt:            packet
+*
+*/
+bool net_rx_pkt_is_tcp_ack(struct NetRxPkt *pkt);
+
+/**
+* check if given packet contains TCP data
+*
+* @pkt:            packet
+*
+*/
+bool net_rx_pkt_has_tcp_data(struct NetRxPkt *pkt);
+
+/**
  * returns virtio header stored in rx context
  *
  * @pkt:            packet
@@ -123,6 +220,37 @@ bool net_rx_pkt_is_vlan_stripped(struct NetRxPkt *pkt);
 bool net_rx_pkt_has_virt_hdr(struct NetRxPkt *pkt);
 
 /**
+* attach scatter-gather data to rx packet
+*
+* @pkt:            packet
+* @iov:            received data scatter-gather list
+* @iovcnt          number of elements in iov
+* @iovoff          data start offset in the iov
+* @strip_vlan:     should the module strip vlan from data
+*
+*/
+void net_rx_pkt_attach_iovec(struct NetRxPkt *pkt,
+                                const struct iovec *iov,
+                                int iovcnt, size_t iovoff,
+                                bool strip_vlan);
+
+/**
+* attach scatter-gather data to rx packet
+*
+* @pkt:            packet
+* @iov:            received data scatter-gather list
+* @iovcnt          number of elements in iov
+* @iovoff          data start offset in the iov
+* @strip_vlan:     should the module strip vlan from data
+* @vet:            VLAN tag Ethernet type
+*
+*/
+void net_rx_pkt_attach_iovec_ex(struct NetRxPkt *pkt,
+                                   const struct iovec *iov, int iovcnt,
+                                   size_t iovoff, bool strip_vlan,
+                                   uint16_t vet);
+
+/**
  * attach data to rx packet
  *
  * @pkt:            packet
@@ -131,8 +259,17 @@ bool net_rx_pkt_has_virt_hdr(struct NetRxPkt *pkt);
  * @strip_vlan:     should the module strip vlan from data
  *
  */
-void net_rx_pkt_attach_data(struct NetRxPkt *pkt, const void *data,
-    size_t len, bool strip_vlan);
+static inline void
+net_rx_pkt_attach_data(struct NetRxPkt *pkt, const void *data,
+                          size_t len, bool strip_vlan)
+{
+    const struct iovec iov = {
+        .iov_base = (void *) data,
+        .iov_len = len
+    };
+
+    net_rx_pkt_attach_iovec(pkt, &iov, 1, 0, strip_vlan);
+}
 
 /**
  * returns io vector that holds the attached data
@@ -144,6 +281,15 @@ void net_rx_pkt_attach_data(struct NetRxPkt *pkt, const void *data,
 struct iovec *net_rx_pkt_get_iovec(struct NetRxPkt *pkt);
 
 /**
+* returns io vector length that holds the attached data
+*
+* @pkt:            packet
+* @ret:            IOVec length
+*
+*/
+uint16_t net_rx_pkt_get_iovec_len(struct NetRxPkt *pkt);
+
+/**
  * prints rx packet data if debug is enabled
  *
  * @pkt:            packet
@@ -162,6 +308,17 @@ void net_rx_pkt_set_vhdr(struct NetRxPkt *pkt,
     struct virtio_net_hdr *vhdr);
 
 /**
+* copy passed vhdr data to packet context
+*
+* @pkt:            packet
+* @iov:            VHDR iov
+* @iovcnt:         VHDR iov array size
+*
+*/
+void net_rx_pkt_set_vhdr_iovec(struct NetRxPkt *pkt,
+    const struct iovec *iov, int iovcnt);
+
+/**
  * save packet type in packet context
  *
  * @pkt:            packet
@@ -171,4 +328,36 @@ void net_rx_pkt_set_vhdr(struct NetRxPkt *pkt,
 void net_rx_pkt_set_packet_type(struct NetRxPkt *pkt,
     eth_pkt_types_e packet_type);
 
+/**
+* validate TCP/UDP checksum of the packet
+*
+* @pkt:            packet
+* @csum_valid:     checksum validation result
+* @ret:            true if validation was performed, false in case packet is
+*                  not TCP/UDP or checksum validation is not possible
+*
+*/
+bool net_rx_pkt_validate_l4_csum(struct NetRxPkt *pkt, bool *csum_valid);
+
+/**
+* validate IPv4 checksum of the packet
+*
+* @pkt:            packet
+* @csum_valid:     checksum validation result
+* @ret:            true if validation was performed, false in case packet is
+*                  not TCP/UDP or checksum validation is not possible
+*
+*/
+bool net_rx_pkt_validate_l3_csum(struct NetRxPkt *pkt, bool *csum_valid);
+
+/**
+* fix IPv4 checksum of the packet
+*
+* @pkt:            packet
+* @ret:            true if checksum was fixed, false in case packet is
+*                  not TCP/UDP or checksum correction is not possible
+*
+*/
+bool net_rx_pkt_fix_l4_csum(struct NetRxPkt *pkt);
+
 #endif
diff --git a/hw/net/net_tx_pkt.c b/hw/net/net_tx_pkt.c
index 94c7e3d3f6..a64f51cbef 100644
--- a/hw/net/net_tx_pkt.c
+++ b/hw/net/net_tx_pkt.c
@@ -15,12 +15,8 @@
  *
  */
 
-#include "qemu/osdep.h"
-#include "hw/hw.h"
 #include "net_tx_pkt.h"
 #include "net/eth.h"
-#include "qemu-common.h"
-#include "qemu/iov.h"
 #include "net/checksum.h"
 #include "net/tap.h"
 #include "net/net.h"
@@ -44,6 +40,7 @@ struct NetTxPkt {
     struct iovec *vec;
 
     uint8_t l2_hdr[ETH_MAX_L2_HDR_LEN];
+    uint8_t l3_hdr[ETH_MAX_IP_DGRAM_LEN];
 
     uint32_t payload_len;
 
@@ -53,6 +50,8 @@ struct NetTxPkt {
     uint16_t hdr_len;
     eth_pkt_types_e packet_type;
     uint8_t l4proto;
+
+    bool is_loopback;
 };
 
 void net_tx_pkt_init(struct NetTxPkt **pkt, uint32_t max_frags,
@@ -72,8 +71,7 @@ void net_tx_pkt_init(struct NetTxPkt **pkt, uint32_t max_frags,
     p->vec[NET_TX_PKT_VHDR_FRAG].iov_len =
         p->has_virt_hdr ? sizeof p->virt_hdr : 0;
     p->vec[NET_TX_PKT_L2HDR_FRAG].iov_base = &p->l2_hdr;
-    p->vec[NET_TX_PKT_L3HDR_FRAG].iov_base = NULL;
-    p->vec[NET_TX_PKT_L3HDR_FRAG].iov_len = 0;
+    p->vec[NET_TX_PKT_L3HDR_FRAG].iov_base = &p->l3_hdr;
 
     *pkt = p;
 }
@@ -87,38 +85,52 @@ void net_tx_pkt_uninit(struct NetTxPkt *pkt)
     }
 }
 
-void net_tx_pkt_update_ip_checksums(struct NetTxPkt *pkt)
+void net_tx_pkt_update_ip_hdr_checksum(struct NetTxPkt *pkt)
 {
     uint16_t csum;
-    uint32_t ph_raw_csum;
     assert(pkt);
-    uint8_t gso_type = pkt->virt_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN;
     struct ip_header *ip_hdr;
-
-    if (VIRTIO_NET_HDR_GSO_TCPV4 != gso_type &&
-        VIRTIO_NET_HDR_GSO_UDP != gso_type) {
-        return;
-    }
-
     ip_hdr = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base;
 
-    if (pkt->payload_len + pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len >
-        ETH_MAX_IP_DGRAM_LEN) {
-        return;
-    }
-
     ip_hdr->ip_len = cpu_to_be16(pkt->payload_len +
         pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len);
 
-    /* Calculate IP header checksum                    */
     ip_hdr->ip_sum = 0;
     csum = net_raw_checksum((uint8_t *)ip_hdr,
         pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len);
     ip_hdr->ip_sum = cpu_to_be16(csum);
+}
+
+void net_tx_pkt_update_ip_checksums(struct NetTxPkt *pkt)
+{
+    uint16_t csum;
+    uint32_t cntr, cso;
+    assert(pkt);
+    uint8_t gso_type = pkt->virt_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN;
+    void *ip_hdr = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base;
+
+    if (pkt->payload_len + pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_len >
+        ETH_MAX_IP_DGRAM_LEN) {
+        return;
+    }
+
+    if (gso_type == VIRTIO_NET_HDR_GSO_TCPV4 ||
+        gso_type == VIRTIO_NET_HDR_GSO_UDP) {
+        /* Calculate IP header checksum */
+        net_tx_pkt_update_ip_hdr_checksum(pkt);
+
+        /* Calculate IP pseudo header checksum */
+        cntr = eth_calc_ip4_pseudo_hdr_csum(ip_hdr, pkt->payload_len, &cso);
+        csum = cpu_to_be16(~net_checksum_finish(cntr));
+    } else if (gso_type == VIRTIO_NET_HDR_GSO_TCPV6) {
+        /* Calculate IP pseudo header checksum */
+        cntr = eth_calc_ip6_pseudo_hdr_csum(ip_hdr, pkt->payload_len,
+                                            IP_PROTO_TCP, &cso);
+        csum = cpu_to_be16(~net_checksum_finish(cntr));
+    } else {
+        return;
+    }
 
-    /* Calculate IP pseudo header checksum             */
-    ph_raw_csum = eth_calc_pseudo_hdr_csum(ip_hdr, pkt->payload_len);
-    csum = cpu_to_be16(~net_checksum_finish(ph_raw_csum));
     iov_from_buf(&pkt->vec[NET_TX_PKT_PL_START_FRAG], pkt->payload_frags,
                  pkt->virt_hdr.csum_offset, &csum, sizeof(csum));
 }
@@ -160,15 +172,19 @@ static bool net_tx_pkt_parse_headers(struct NetTxPkt *pkt)
 
     if (bytes_read < l2_hdr->iov_len) {
         l2_hdr->iov_len = 0;
+        l3_hdr->iov_len = 0;
+        pkt->packet_type = ETH_PKT_UCAST;
         return false;
+    } else {
+        l2_hdr->iov_len = ETH_MAX_L2_HDR_LEN;
+        l2_hdr->iov_len = eth_get_l2_hdr_length(l2_hdr->iov_base);
+        pkt->packet_type = get_eth_packet_type(l2_hdr->iov_base);
     }
 
-    l3_proto = eth_get_l3_proto(l2_hdr->iov_base, l2_hdr->iov_len);
+    l3_proto = eth_get_l3_proto(l2_hdr, 1, l2_hdr->iov_len);
 
     switch (l3_proto) {
     case ETH_P_IP:
-        l3_hdr->iov_base = g_malloc(ETH_MAX_IP4_HDR_LEN);
-
         bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, l2_hdr->iov_len,
                                 l3_hdr->iov_base, sizeof(struct ip_header));
 
@@ -178,27 +194,45 @@ static bool net_tx_pkt_parse_headers(struct NetTxPkt *pkt)
         }
 
         l3_hdr->iov_len = IP_HDR_GET_LEN(l3_hdr->iov_base);
-        pkt->l4proto = ((struct ip_header *) l3_hdr->iov_base)->ip_p;
 
-        /* copy optional IPv4 header data */
-        bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags,
-                                l2_hdr->iov_len + sizeof(struct ip_header),
-                                l3_hdr->iov_base + sizeof(struct ip_header),
-                                l3_hdr->iov_len - sizeof(struct ip_header));
-        if (bytes_read < l3_hdr->iov_len - sizeof(struct ip_header)) {
+        if (l3_hdr->iov_len < sizeof(struct ip_header)) {
             l3_hdr->iov_len = 0;
             return false;
         }
+
+        pkt->l4proto = ((struct ip_header *) l3_hdr->iov_base)->ip_p;
+
+        if (IP_HDR_GET_LEN(l3_hdr->iov_base) != sizeof(struct ip_header)) {
+            /* copy optional IPv4 header data if any*/
+            bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags,
+                                    l2_hdr->iov_len + sizeof(struct ip_header),
+                                    l3_hdr->iov_base + sizeof(struct ip_header),
+                                    l3_hdr->iov_len - sizeof(struct ip_header));
+            if (bytes_read < l3_hdr->iov_len - sizeof(struct ip_header)) {
+                l3_hdr->iov_len = 0;
+                return false;
+            }
+        }
+
         break;
 
     case ETH_P_IPV6:
+    {
+        eth_ip6_hdr_info hdrinfo;
+
         if (!eth_parse_ipv6_hdr(pkt->raw, pkt->raw_frags, l2_hdr->iov_len,
-                               &pkt->l4proto, &full_ip6hdr_len)) {
+                                &hdrinfo)) {
             l3_hdr->iov_len = 0;
             return false;
         }
 
-        l3_hdr->iov_base = g_malloc(full_ip6hdr_len);
+        pkt->l4proto = hdrinfo.l4proto;
+        full_ip6hdr_len = hdrinfo.full_hdr_len;
+
+        if (full_ip6hdr_len > ETH_MAX_IP_DGRAM_LEN) {
+            l3_hdr->iov_len = 0;
+            return false;
+        }
 
         bytes_read = iov_to_buf(pkt->raw, pkt->raw_frags, l2_hdr->iov_len,
                                 l3_hdr->iov_base, full_ip6hdr_len);
@@ -210,40 +244,35 @@ static bool net_tx_pkt_parse_headers(struct NetTxPkt *pkt)
             l3_hdr->iov_len = full_ip6hdr_len;
         }
         break;
-
+    }
     default:
         l3_hdr->iov_len = 0;
         break;
     }
 
     net_tx_pkt_calculate_hdr_len(pkt);
-    pkt->packet_type = get_eth_packet_type(l2_hdr->iov_base);
     return true;
 }
 
-static bool net_tx_pkt_rebuild_payload(struct NetTxPkt *pkt)
+static void net_tx_pkt_rebuild_payload(struct NetTxPkt *pkt)
 {
-    size_t payload_len = iov_size(pkt->raw, pkt->raw_frags) - pkt->hdr_len;
-
+    pkt->payload_len = iov_size(pkt->raw, pkt->raw_frags) - pkt->hdr_len;
     pkt->payload_frags = iov_copy(&pkt->vec[NET_TX_PKT_PL_START_FRAG],
                                 pkt->max_payload_frags,
                                 pkt->raw, pkt->raw_frags,
-                                pkt->hdr_len, payload_len);
+                                pkt->hdr_len, pkt->payload_len);
+}
 
-    if (pkt->payload_frags != (uint32_t) -1) {
-        pkt->payload_len = payload_len;
+bool net_tx_pkt_parse(struct NetTxPkt *pkt)
+{
+    if (net_tx_pkt_parse_headers(pkt)) {
+        net_tx_pkt_rebuild_payload(pkt);
         return true;
     } else {
         return false;
     }
 }
 
-bool net_tx_pkt_parse(struct NetTxPkt *pkt)
-{
-    return net_tx_pkt_parse_headers(pkt) &&
-           net_tx_pkt_rebuild_payload(pkt);
-}
-
 struct virtio_net_hdr *net_tx_pkt_get_vhdr(struct NetTxPkt *pkt)
 {
     assert(pkt);
@@ -256,7 +285,7 @@ static uint8_t net_tx_pkt_get_gso_type(struct NetTxPkt *pkt,
     uint8_t rc = VIRTIO_NET_HDR_GSO_NONE;
     uint16_t l3_proto;
 
-    l3_proto = eth_get_l3_proto(pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_base,
+    l3_proto = eth_get_l3_proto(&pkt->vec[NET_TX_PKT_L2HDR_FRAG], 1,
         pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_len);
 
     if (!tso_enable) {
@@ -288,7 +317,7 @@ void net_tx_pkt_build_vheader(struct NetTxPkt *pkt, bool tso_enable,
         break;
 
     case VIRTIO_NET_HDR_GSO_UDP:
-        pkt->virt_hdr.gso_size = IP_FRAG_ALIGN_SIZE(gso_size);
+        pkt->virt_hdr.gso_size = gso_size;
         pkt->virt_hdr.hdr_len = pkt->hdr_len + sizeof(struct udp_header);
         break;
 
@@ -297,7 +326,7 @@ void net_tx_pkt_build_vheader(struct NetTxPkt *pkt, bool tso_enable,
         iov_to_buf(&pkt->vec[NET_TX_PKT_PL_START_FRAG], pkt->payload_frags,
                    0, &l4hdr, sizeof(l4hdr));
         pkt->virt_hdr.hdr_len = pkt->hdr_len + l4hdr.th_off * sizeof(uint32_t);
-        pkt->virt_hdr.gso_size = IP_FRAG_ALIGN_SIZE(gso_size);
+        pkt->virt_hdr.gso_size = gso_size;
         break;
 
     default:
@@ -322,13 +351,14 @@ void net_tx_pkt_build_vheader(struct NetTxPkt *pkt, bool tso_enable,
     }
 }
 
-void net_tx_pkt_setup_vlan_header(struct NetTxPkt *pkt, uint16_t vlan)
+void net_tx_pkt_setup_vlan_header_ex(struct NetTxPkt *pkt,
+    uint16_t vlan, uint16_t vlan_ethtype)
 {
     bool is_new;
     assert(pkt);
 
-    eth_setup_vlan_headers(pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_base,
-        vlan, &is_new);
+    eth_setup_vlan_headers_ex(pkt->vec[NET_TX_PKT_L2HDR_FRAG].iov_base,
+        vlan, vlan_ethtype, &is_new);
 
     /* update l2hdrlen */
     if (is_new) {
@@ -354,14 +384,19 @@ bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, hwaddr pa,
     mapped_len = len;
 
     ventry->iov_base = cpu_physical_memory_map(pa, &mapped_len, false);
-    ventry->iov_len = mapped_len;
-    pkt->raw_frags += !!ventry->iov_base;
 
-    if ((ventry->iov_base == NULL) || (len != mapped_len)) {
+    if ((ventry->iov_base != NULL) && (len == mapped_len)) {
+        ventry->iov_len = mapped_len;
+        pkt->raw_frags++;
+        return true;
+    } else {
         return false;
     }
+}
 
-    return true;
+bool net_tx_pkt_has_fragments(struct NetTxPkt *pkt)
+{
+    return pkt->raw_frags > 0;
 }
 
 eth_pkt_types_e net_tx_pkt_get_packet_type(struct NetTxPkt *pkt)
@@ -401,14 +436,8 @@ void net_tx_pkt_reset(struct NetTxPkt *pkt)
 
     memset(&pkt->virt_hdr, 0, sizeof(pkt->virt_hdr));
 
-    g_free(pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base);
-    pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base = NULL;
-
     assert(pkt->vec);
-    for (i = NET_TX_PKT_L2HDR_FRAG;
-         i < pkt->payload_frags + NET_TX_PKT_PL_START_FRAG; i++) {
-        pkt->vec[i].iov_len = 0;
-    }
+
     pkt->payload_len = 0;
     pkt->payload_frags = 0;
 
@@ -417,12 +446,10 @@ void net_tx_pkt_reset(struct NetTxPkt *pkt)
         assert(pkt->raw[i].iov_base);
         cpu_physical_memory_unmap(pkt->raw[i].iov_base, pkt->raw[i].iov_len,
                                   false, pkt->raw[i].iov_len);
-        pkt->raw[i].iov_len = 0;
     }
     pkt->raw_frags = 0;
 
     pkt->hdr_len = 0;
-    pkt->packet_type = 0;
     pkt->l4proto = 0;
 }
 
@@ -431,6 +458,7 @@ static void net_tx_pkt_do_sw_csum(struct NetTxPkt *pkt)
     struct iovec *iov = &pkt->vec[NET_TX_PKT_L2HDR_FRAG];
     uint32_t csum_cntr;
     uint16_t csum = 0;
+    uint32_t cso;
     /* num of iovec without vhdr */
     uint32_t iov_len = pkt->payload_frags + NET_TX_PKT_PL_START_FRAG - 1;
     uint16_t csl;
@@ -443,12 +471,13 @@ static void net_tx_pkt_do_sw_csum(struct NetTxPkt *pkt)
     /* Calculate L4 TCP/UDP checksum */
     csl = pkt->payload_len;
 
-    /* data checksum */
-    csum_cntr =
-        net_checksum_add_iov(iov, iov_len, pkt->virt_hdr.csum_start, csl);
     /* add pseudo header to csum */
     iphdr = pkt->vec[NET_TX_PKT_L3HDR_FRAG].iov_base;
-    csum_cntr += eth_calc_pseudo_hdr_csum(iphdr, csl);
+    csum_cntr = eth_calc_ip4_pseudo_hdr_csum(iphdr, csl, &cso);
+
+    /* data checksum */
+    csum_cntr +=
+        net_checksum_add_iov(iov, iov_len, pkt->virt_hdr.csum_start, csl, cso);
 
     /* Put the checksum obtained into the packet */
     csum = cpu_to_be16(net_checksum_finish(csum_cntr));
@@ -471,7 +500,7 @@ static size_t net_tx_pkt_fetch_fragment(struct NetTxPkt *pkt,
 
     *dst_idx = NET_TX_PKT_FRAGMENT_HEADER_NUM;
 
-    while (fetched < pkt->virt_hdr.gso_size) {
+    while (fetched < IP_FRAG_ALIGN_SIZE(pkt->virt_hdr.gso_size)) {
 
         /* no more place in fragment iov */
         if (*dst_idx == NET_MAX_FRAG_SG_LIST) {
@@ -486,7 +515,7 @@ static size_t net_tx_pkt_fetch_fragment(struct NetTxPkt *pkt,
 
         dst[*dst_idx].iov_base = src[*src_idx].iov_base + *src_offset;
         dst[*dst_idx].iov_len = MIN(src[*src_idx].iov_len - *src_offset,
-            pkt->virt_hdr.gso_size - fetched);
+            IP_FRAG_ALIGN_SIZE(pkt->virt_hdr.gso_size) - fetched);
 
         *src_offset += dst[*dst_idx].iov_len;
         fetched += dst[*dst_idx].iov_len;
@@ -502,6 +531,16 @@ static size_t net_tx_pkt_fetch_fragment(struct NetTxPkt *pkt,
     return fetched;
 }
 
+static inline void net_tx_pkt_sendv(struct NetTxPkt *pkt,
+    NetClientState *nc, const struct iovec *iov, int iov_cnt)
+{
+    if (pkt->is_loopback) {
+        nc->info->receive_iov(nc, iov, iov_cnt);
+    } else {
+        qemu_sendv_packet(nc, iov, iov_cnt);
+    }
+}
+
 static bool net_tx_pkt_do_sw_fragmentation(struct NetTxPkt *pkt,
     NetClientState *nc)
 {
@@ -540,7 +579,7 @@ static bool net_tx_pkt_do_sw_fragmentation(struct NetTxPkt *pkt,
 
         eth_fix_ip4_checksum(l3_iov_base, l3_iov_len);
 
-        qemu_sendv_packet(nc, fragment, dst_idx);
+        net_tx_pkt_sendv(pkt, nc, fragment, dst_idx);
 
         fragment_offset += fragment_len;
 
@@ -572,10 +611,21 @@ bool net_tx_pkt_send(struct NetTxPkt *pkt, NetClientState *nc)
 
     if (pkt->has_virt_hdr ||
         pkt->virt_hdr.gso_type == VIRTIO_NET_HDR_GSO_NONE) {
-        qemu_sendv_packet(nc, pkt->vec,
+        net_tx_pkt_sendv(pkt, nc, pkt->vec,
             pkt->payload_frags + NET_TX_PKT_PL_START_FRAG);
         return true;
     }
 
     return net_tx_pkt_do_sw_fragmentation(pkt, nc);
 }
+
+bool net_tx_pkt_send_loopback(struct NetTxPkt *pkt, NetClientState *nc)
+{
+    bool res;
+
+    pkt->is_loopback = true;
+    res = net_tx_pkt_send(pkt, nc);
+    pkt->is_loopback = false;
+
+    return res;
+}
diff --git a/hw/net/net_tx_pkt.h b/hw/net/net_tx_pkt.h
index be2e117b7d..e49772d238 100644
--- a/hw/net/net_tx_pkt.h
+++ b/hw/net/net_tx_pkt.h
@@ -18,6 +18,7 @@
 #ifndef NET_TX_PKT_H
 #define NET_TX_PKT_H
 
+#include "qemu/osdep.h"
 #include "net/eth.h"
 #include "exec/hwaddr.h"
 
@@ -64,13 +65,29 @@ void net_tx_pkt_build_vheader(struct NetTxPkt *pkt, bool tso_enable,
     bool csum_enable, uint32_t gso_size);
 
 /**
- * updates vlan tag, and adds vlan header in case it is missing
- *
- * @pkt:            packet
- * @vlan:           VLAN tag
- *
- */
-void net_tx_pkt_setup_vlan_header(struct NetTxPkt *pkt, uint16_t vlan);
+* updates vlan tag, and adds vlan header with custom ethernet type
+* in case it is missing.
+*
+* @pkt:            packet
+* @vlan:           VLAN tag
+* @vlan_ethtype:   VLAN header Ethernet type
+*
+*/
+void net_tx_pkt_setup_vlan_header_ex(struct NetTxPkt *pkt,
+    uint16_t vlan, uint16_t vlan_ethtype);
+
+/**
+* updates vlan tag, and adds vlan header in case it is missing
+*
+* @pkt:            packet
+* @vlan:           VLAN tag
+*
+*/
+static inline void
+net_tx_pkt_setup_vlan_header(struct NetTxPkt *pkt, uint16_t vlan)
+{
+    net_tx_pkt_setup_vlan_header_ex(pkt, vlan, ETH_P_VLAN);
+}
 
 /**
  * populate data fragment into pkt context.
@@ -84,7 +101,7 @@ bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, hwaddr pa,
     size_t len);
 
 /**
- * fix ip header fields and calculate checksums needed.
+ * Fix ip header fields and calculate IP header and pseudo header checksums.
  *
  * @pkt:            packet
  *
@@ -92,6 +109,14 @@ bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, hwaddr pa,
 void net_tx_pkt_update_ip_checksums(struct NetTxPkt *pkt);
 
 /**
+ * Calculate the IP header checksum.
+ *
+ * @pkt:            packet
+ *
+ */
+void net_tx_pkt_update_ip_hdr_checksum(struct NetTxPkt *pkt);
+
+/**
  * get length of all populated data.
  *
  * @pkt:            packet
@@ -136,6 +161,17 @@ void net_tx_pkt_reset(struct NetTxPkt *pkt);
 bool net_tx_pkt_send(struct NetTxPkt *pkt, NetClientState *nc);
 
 /**
+* Redirect packet directly to receive path (emulate loopback phy).
+* Handles sw offloads if vhdr is not supported.
+*
+* @pkt:            packet
+* @nc:             NetClientState
+* @ret:            operation result
+*
+*/
+bool net_tx_pkt_send_loopback(struct NetTxPkt *pkt, NetClientState *nc);
+
+/**
  * parse raw packet data and analyze offload requirements.
  *
  * @pkt:            packet
@@ -143,4 +179,12 @@ bool net_tx_pkt_send(struct NetTxPkt *pkt, NetClientState *nc);
  */
 bool net_tx_pkt_parse(struct NetTxPkt *pkt);
 
+/**
+* indicates if there are data fragments held by this packet object.
+*
+* @pkt:            packet
+*
+*/
+bool net_tx_pkt_has_fragments(struct NetTxPkt *pkt);
+
 #endif