+struct avf_ip4_psh
+{
+ u32 src;
+ u32 dst;
+ u8 zero;
+ u8 proto;
+ u16 l4len;
+};
+
+struct avf_ip6_psh
+{
+ u32 src[4];
+ u32 dst[4];
+ u32 l4len;
+ u32 proto;
+};
+
+static_always_inline u64
+avf_tx_prepare_cksum (vlib_buffer_t * b, u8 is_tso)
+{
+ u64 flags = 0;
+ if (!is_tso && !(b->flags & ((VNET_BUFFER_F_OFFLOAD_IP_CKSUM |
+ VNET_BUFFER_F_OFFLOAD_TCP_CKSUM |
+ VNET_BUFFER_F_OFFLOAD_UDP_CKSUM))))
+ return 0;
+ u32 is_tcp = is_tso || b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
+ u32 is_udp = !is_tso && b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
+ u32 is_ip4 = b->flags & VNET_BUFFER_F_IS_IP4;
+ u32 is_ip6 = b->flags & VNET_BUFFER_F_IS_IP6;
+ ASSERT (!is_tcp || !is_udp);
+ ASSERT (is_ip4 || is_ip6);
+ i16 l2_hdr_offset = vnet_buffer (b)->l2_hdr_offset;
+ i16 l3_hdr_offset = vnet_buffer (b)->l3_hdr_offset;
+ i16 l4_hdr_offset = vnet_buffer (b)->l4_hdr_offset;
+ u16 l2_len = l3_hdr_offset - l2_hdr_offset;
+ u16 l3_len = l4_hdr_offset - l3_hdr_offset;
+ ip4_header_t *ip4 = (void *) (b->data + l3_hdr_offset);
+ ip6_header_t *ip6 = (void *) (b->data + l3_hdr_offset);
+ tcp_header_t *tcp = (void *) (b->data + l4_hdr_offset);
+ udp_header_t *udp = (void *) (b->data + l4_hdr_offset);
+ u16 l4_len =
+ is_tcp ? tcp_header_bytes (tcp) : is_udp ? sizeof (udp_header_t) : 0;
+ u16 sum = 0;
+
+ flags |= AVF_TXD_OFFSET_MACLEN (l2_len) |
+ AVF_TXD_OFFSET_IPLEN (l3_len) | AVF_TXD_OFFSET_L4LEN (l4_len);
+ flags |= is_ip4 ? AVF_TXD_CMD_IIPT_IPV4 : AVF_TXD_CMD_IIPT_IPV6;
+ flags |= is_tcp ? AVF_TXD_CMD_L4T_TCP : is_udp ? AVF_TXD_CMD_L4T_UDP : 0;
+
+ if (is_ip4)
+ ip4->checksum = 0;
+
+ if (is_tcp || is_udp)
+ {
+ if (is_ip4)
+ {
+ struct avf_ip4_psh psh = { 0 };
+ psh.src = ip4->src_address.as_u32;
+ psh.dst = ip4->dst_address.as_u32;
+ psh.proto = ip4->protocol;
+ psh.l4len =
+ is_tso ? 0 :
+ clib_host_to_net_u16 (clib_net_to_host_u16 (ip4->length) -
+ (l4_hdr_offset - l3_hdr_offset));
+ sum = ~ip_csum (&psh, sizeof (psh));
+ }
+ else
+ {
+ struct avf_ip6_psh psh = { 0 };
+ clib_memcpy_fast (&psh.src, &ip6->src_address, 32);
+ psh.proto = clib_host_to_net_u32 ((u32) ip6->protocol);
+ psh.l4len = is_tso ? 0 : ip6->payload_length;
+ sum = ~ip_csum (&psh, sizeof (psh));
+ }
+ }
+ /* ip_csum does a byte swap for some reason... */
+ sum = clib_net_to_host_u16 (sum);
+ if (is_tcp)
+ tcp->checksum = sum;
+ else if (is_udp)
+ udp->checksum = sum;
+ return flags;
+}
+