From: Phil Sutter <phil@nwl.cc>
To: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Subject: [PATCH v2 2/3] af_packet: fix for sending VLAN frames via packet_mmap
Date: Fri, 2 Aug 2013 11:37:40 +0200 [thread overview]
Message-ID: <1375436261-6746-2-git-send-email-phil@nwl.cc> (raw)
In-Reply-To: <1375436261-6746-1-git-send-email-phil@nwl.cc>
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>
---
net/packet/af_packet.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index e549e17..ce7b4f0 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -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);
--
1.8.1.5
next prev parent reply other threads:[~2013-08-02 9:38 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-29 16:53 packet_mmap, 802.1Q and bridges Phil Sutter
2013-07-31 17:27 ` Parse ethernet headers in af_packet.c Phil Sutter
2013-07-31 17:27 ` [PATCH 1/3] af_packet: when sending ethernet frames, parse header for skb->protocol Phil Sutter
2013-07-31 17:27 ` [PATCH 2/3] af_packet: fix for sending VLAN frames via packet_mmap Phil Sutter
2013-07-31 17:27 ` [PATCH 3/3] af_packet: simplify VLAN frame check in packet_snd Phil Sutter
2013-08-01 0:30 ` [PATCH 1/3] af_packet: when sending ethernet frames, parse header for skb->protocol David Miller
2013-08-01 10:35 ` Phil Sutter
2013-08-02 1:12 ` David Miller
2013-08-02 9:37 ` [PATCH v2 " Phil Sutter
2013-08-02 9:37 ` Phil Sutter [this message]
2013-08-02 9:37 ` [PATCH v2 3/3] af_packet: simplify VLAN frame check in packet_snd Phil Sutter
2013-08-02 21:59 ` David Miller
2013-08-02 21:58 ` [PATCH v2 2/3] af_packet: fix for sending VLAN frames via packet_mmap David Miller
2013-08-02 21:58 ` [PATCH v2 1/3] af_packet: when sending ethernet frames, parse header for skb->protocol David Miller
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