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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-10-07 05:45:57 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-10-18 23:33:44 -0400 |
| commit | 09df57ca604512b29b6096afb381c839ccbd2912 (patch) | |
| tree | d7a820fea1ef93ad5a2e8ba74926b85b451428cb | |
| parent | bc416d9768aa9a2e46eb11354a9c58399dafeb01 (diff) | |
| download | linux-09df57ca604512b29b6096afb381c839ccbd2912.tar.gz linux-09df57ca604512b29b6096afb381c839ccbd2912.tar.bz2 linux-09df57ca604512b29b6096afb381c839ccbd2912.zip | |
l2tp: give proper headroom in pppol2tp_xmit()
pppol2tp_xmit() calls skb_cow_head(skb, 2) before calling
l2tp_xmit_skb()
Then l2tp_xmit_skb() calls again skb_cow_head(skb, large_headroom)
This patchs changes the first skb_cow_head() call to supply the needed
headroom to make sure at most one (expensive) pskb_expand_head() is
done.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/l2tp/l2tp_ppp.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index f42cd0915966..8a90d756c904 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -395,6 +395,7 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) struct pppol2tp_session *ps; int old_headroom; int new_headroom; + int uhlen, headroom; if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) goto abort; @@ -413,7 +414,13 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) goto abort_put_sess; old_headroom = skb_headroom(skb); - if (skb_cow_head(skb, sizeof(ppph))) + uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; + headroom = NET_SKB_PAD + + sizeof(struct iphdr) + /* IP header */ + uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */ + session->hdr_len + /* L2TP header */ + sizeof(ppph); /* PPP header */ + if (skb_cow_head(skb, headroom)) goto abort_put_sess_tun; new_headroom = skb_headroom(skb); |