====================
From 09effa67a18d893fc4e6f81a3659fc9efef1445e Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Wed, 7 Aug 2013 17:11:00 -0700
Subject: [PATCH] packet: Revert recent header parsing changes.
This reverts commits:
0f75b09c798ed00c30d7d5551b896be883bc2aeb
cbd89acb9eb257ed3b2be867142583fdcf7fdc5b
c483e02614551e44ced3fe6eedda8e36d3277ccc
Amongst other things, it's modifies the SKB header
to pull the ethernet headers off via eth_type_trans()
on the output path which is bogus.
It's causing serious regressions for people.
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/packet/af_packet.c | 53 ++++++++++++++++++++++--------------------------
1 file changed, 24 insertions(+), 29 deletions(-)
@@ -88,7 +88,6 @@
#include <linux/virtio_net.h>
#include <linux/errqueue.h>
#include <linux/net_tstamp.h>
-#include <linux/if_arp.h>
#ifdef CONFIG_INET
#include <net/inet_common.h>
@@ -1924,7 +1923,7 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
__be16 proto, unsigned char *addr, int hlen)
{
union tpacket_uhdr ph;
- int to_write, offset, len, tp_len, nr_frags, len_max, max_frame_len;
+ int to_write, offset, len, tp_len, nr_frags, len_max;
struct socket *sock = po->sk.sk_socket;
struct page *page;
void *data;
@@ -1947,6 +1946,10 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
tp_len = ph.h1->tp_len;
break;
}
+ if (unlikely(tp_len > size_max)) {
+ pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
+ return -EMSGSIZE;
+ }
skb_reserve(skb, hlen);
skb_reset_network_header(skb);
@@ -2002,25 +2005,10 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
if (unlikely(err))
return err;
- if (dev->type == ARPHRD_ETHER)
- skb->protocol = eth_type_trans(skb, dev);
-
data += dev->hard_header_len;
to_write -= dev->hard_header_len;
}
- max_frame_len = dev->mtu + dev->hard_header_len;
- if (skb->protocol == htons(ETH_P_8021Q))
- max_frame_len += VLAN_HLEN;
-
- if (size_max > max_frame_len)
- size_max = max_frame_len;
-
- if (unlikely(tp_len > size_max)) {
- pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
- return -EMSGSIZE;
- }
-
offset = offset_in_page(data);
len_max = PAGE_SIZE - offset;
len = ((to_write > len_max) ? len_max : to_write);
@@ -2059,7 +2047,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
struct net_device *dev;
__be16 proto;
bool need_rls_dev = false;
- int err;
+ int err, reserve = 0;
void *ph;
struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
int tp_len, size_max;
@@ -2092,6 +2080,8 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
if (unlikely(dev == NULL))
goto out;
+ reserve = dev->hard_header_len;
+
err = -ENETDOWN;
if (unlikely(!(dev->flags & IFF_UP)))
goto out_put;
@@ -2099,6 +2089,9 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
size_max = po->tx_ring.frame_size
- (po->tp_hdrlen - sizeof(struct sockaddr_ll));
+ if (size_max > dev->mtu + reserve)
+ size_max = dev->mtu + reserve;
+
do {
ph = packet_current_frame(po, &po->tx_ring,
TP_STATUS_SEND_REQUEST);
@@ -2331,20 +2324,22 @@ static int packet_snd(struct socket *sock,
sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
- if (dev->type == ARPHRD_ETHER) {
- skb->protocol = eth_type_trans(skb, dev);
- if (skb->protocol == htons(ETH_P_8021Q))
- reserve += VLAN_HLEN;
- } else {
- skb->protocol = proto;
- skb->dev = dev;
- }
-
if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
- err = -EMSGSIZE;
- goto out_free;
+ /* Earlier code assumed this would be a VLAN pkt,
+ * double-check this now that we have the actual
+ * packet in hand.
+ */
+ struct ethhdr *ehdr;
+ skb_reset_mac_header(skb);
+ ehdr = eth_hdr(skb);
+ if (ehdr->h_proto != htons(ETH_P_8021Q)) {
+ err = -EMSGSIZE;
+ goto out_free;
+ }
}
+ skb->protocol = proto;
+ skb->dev = dev;
skb->priority = sk->sk_priority;
skb->mark = sk->sk_mark;