From: Nathan Skrzypczak Date: Thu, 25 Nov 2021 17:44:01 +0000 (+0100) Subject: devices: fix af_packet GSO check X-Git-Tag: v22.06-rc0~179 X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=9adcc9778c316d4c94c6734b8c8e4ce0daede820;p=vpp.git devices: fix af_packet GSO check Type: fix This fixes the GSO size calculation in af_packet which didn't include the ethernet size. This is not ideal, as we default to the host side mtu to check whether a packet is GSO or not and to set the GSO size. But there doesn't seem to be more info passed with the packets. Change-Id: I9769e1dd21d5989b4cf67295352b5535454f88d1 Signed-off-by: Nathan Skrzypczak --- diff --git a/src/vnet/devices/af_packet/node.c b/src/vnet/devices/af_packet/node.c index 0fdae5c3039..efe701642bb 100644 --- a/src/vnet/devices/af_packet/node.c +++ b/src/vnet/devices/af_packet/node.c @@ -209,6 +209,7 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node, u32 thread_index = vm->thread_index; u32 n_buffer_bytes = vlib_buffer_get_default_data_size (vm); u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes; + u32 eth_header_size = 0; vlib_buffer_t bt; if (apif->mode == AF_PACKET_IF_MODE_IP) @@ -217,6 +218,7 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node, } else { + eth_header_size = sizeof (ethernet_header_t); next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT; if (PREDICT_FALSE (apif->per_interface_next_index != ~0)) next_index = apif->per_interface_next_index; @@ -307,7 +309,10 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node, first_b0 = vlib_get_buffer (vm, first_bi0); if (tph->tp_status & TP_STATUS_CSUMNOTREADY) mark_tcp_udp_cksum_calc (first_b0, &l4_hdr_sz); - if (tph->tp_snaplen > apif->host_mtu) + /* This is a trade-off for GSO. As kernel isn't passing + * us the GSO state or size, we guess it by comparing it + * to the host MTU of the interface */ + if (tph->tp_snaplen > (apif->host_mtu + eth_header_size)) fill_gso_buffer_flags (first_b0, apif->host_mtu, l4_hdr_sz); }