packet: set transport header before doing xmit
Set the transport header for 1) some drivers (e.g ixgbe needs l4 header to do
atr) 2) precise packet length estimation (introduced in 1def9238) needs l4
header to compute header length.
So this patch first tries to get l4 header for packet socket through
skb_flow_dissect(), and pretend no l4 header if skb_flow_dissect() fails.
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index bd0d14c..83fdd0a 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -88,6 +88,7 @@
#include <linux/virtio_net.h>
#include <linux/errqueue.h>
#include <linux/net_tstamp.h>
+#include <net/flow_keys.h>
#ifdef CONFIG_INET
#include <net/inet_common.h>
@@ -1412,6 +1413,7 @@
__be16 proto = 0;
int err;
int extra_len = 0;
+ struct flow_keys keys;
/*
* Get and verify the address.
@@ -1512,6 +1514,11 @@
if (unlikely(extra_len == 4))
skb->no_fcs = 1;
+ if (skb_flow_dissect(skb, &keys))
+ skb_set_transport_header(skb, keys.thoff);
+ else
+ skb_reset_transport_header(skb);
+
dev_queue_xmit(skb);
rcu_read_unlock();
return len;
@@ -1918,6 +1925,7 @@
struct page *page;
void *data;
int err;
+ struct flow_keys keys;
ph.raw = frame;
@@ -1943,6 +1951,11 @@
skb_reserve(skb, hlen);
skb_reset_network_header(skb);
+ if (skb_flow_dissect(skb, &keys))
+ skb_set_transport_header(skb, keys.thoff);
+ else
+ skb_reset_transport_header(skb);
+
if (po->tp_tx_has_off) {
int off_min, off_max, off;
off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
@@ -2199,6 +2212,7 @@
unsigned short gso_type = 0;
int hlen, tlen;
int extra_len = 0;
+ struct flow_keys keys;
/*
* Get and verify the address.
@@ -2351,6 +2365,13 @@
len += vnet_hdr_len;
}
+ if (skb->ip_summed == CHECKSUM_PARTIAL)
+ skb_set_transport_header(skb, skb_checksum_start_offset(skb));
+ else if (skb_flow_dissect(skb, &keys))
+ skb_set_transport_header(skb, keys.thoff);
+ else
+ skb_set_transport_header(skb, reserve);
+
if (unlikely(extra_len == 4))
skb->no_fcs = 1;