net: switch to use skb_probe_transport_header()

Switch to use the new help skb_probe_transport_header() to do the l4 header
probing for untrusted sources. For packets with partial csum, the header should
already been set by skb_partial_csum_set().

Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 19 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 83fdd0a87eb6..8e4644ff8d34 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -88,7 +88,6 @@
 #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>
@@ -1413,7 +1412,6 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
         __be16 proto = 0;
         int err;
         int extra_len = 0;
-        struct flow_keys keys;
 
         /*
          *      Get and verify the address.
@@ -1514,10 +1512,7 @@ retry:
         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);
+        skb_probe_transport_header(skb, 0);
 
         dev_queue_xmit(skb);
         rcu_read_unlock();
@@ -1925,7 +1920,6 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
         struct page *page;
         void *data;
         int err;
-        struct flow_keys keys;
 
         ph.raw = frame;
 
@@ -1950,11 +1944,7 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
 
         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);
+        skb_probe_transport_header(skb, 0);
 
         if (po->tp_tx_has_off) {
                 int off_min, off_max, off;
@@ -2212,7 +2202,6 @@ static int packet_snd(struct socket *sock,
         unsigned short gso_type = 0;
         int hlen, tlen;
         int extra_len = 0;
-        struct flow_keys keys;
 
         /*
          *      Get and verify the address.
@@ -2365,12 +2354,7 @@ static int packet_snd(struct socket *sock,
                 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);
+        skb_probe_transport_header(skb, reserve);
 
         if (unlikely(extra_len == 4))
                 skb->no_fcs = 1;