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af_packet: fix for sending VLAN frames via packet_mmap

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Since tpacket_fill_skb() parses the protocol field in ethernet frames'
headers, it's easy to see if any passed frame is a VLAN one and account
for the extended size.

But as the real protocol does not turn up before tpacket_fill_skb()
runs which in turn also checks the frame length, move the max frame
length calculation into the function.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Phil Sutter 2013-08-02 11:37:40 +02:00 committed by David S. Miller
parent 0f75b09c79
commit cbd89acb9e
1 changed files with 14 additions and 11 deletions
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25
net/packet/af_packet.c
View file

@ -1924,7 +1924,7 @@ 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;
int to_write, offset, len, tp_len, nr_frags, len_max, max_frame_len;
struct socket *sock = po->sk.sk_socket;
struct page *page;
void *data;
@ -1947,10 +1947,6 @@ 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);
@ -2013,6 +2009,18 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
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);
@ -2051,7 +2059,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
struct net_device *dev;
__be16 proto;
bool need_rls_dev = false;
int err, reserve = 0;
int err;
void *ph;
struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
int tp_len, size_max;
@ -2084,8 +2092,6 @@ 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;
@ -2093,9 +2099,6 @@ 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);