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| author | Yoshiki Komachi <komachi.yoshiki@lab.ntt.co.jp> | 2019-03-18 14:39:52 +0900 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-03-18 18:11:40 -0700 |
| commit | 18bed89107a400af0d672ec85a270f1545db2569 (patch) | |
| tree | ea7fc6065e464e6daa3669458c9af2059431034c /net/packet/af_packet.c | |
| parent | a4dc6a49156b1f8d6e17251ffda17c9e6a5db78a (diff) | |
| download | lwn-18bed89107a400af0d672ec85a270f1545db2569.tar.gz lwn-18bed89107a400af0d672ec85a270f1545db2569.zip | |
af_packet: fix the tx skb protocol in raw sockets with ETH_P_ALL
I am using "protocol ip" filters in TC to manipulate TC flower
classifiers, which are only available with "protocol ip". However,
I faced an issue that packets sent via raw sockets with ETH_P_ALL
did not match the ip filters even if they did satisfy the condition
(e.g., DHCP offer from dhcpd).
I have determined that the behavior was caused by an unexpected
value stored in skb->protocol, namely, ETH_P_ALL instead of ETH_P_IP,
when packets were sent via raw sockets with ETH_P_ALL set.
IMHO, storing ETH_P_ALL in skb->protocol is not appropriate for
packets sent via raw sockets because ETH_P_ALL is not a real ether
type used on wire, but a virtual one.
This patch fixes the tx protocol selection in cases of transmission
via raw sockets created with ETH_P_ALL so that it asks the driver to
extract protocol from the Ethernet header.
Fixes: 75c65772c3 ("net/packet: Ask driver for protocol if not provided by user")
Signed-off-by: Yoshiki Komachi <komachi.yoshiki@lab.ntt.co.jp>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/packet/af_packet.c')
| -rw-r--r-- | net/packet/af_packet.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 8754d7c93b84..323655a25674 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1852,7 +1852,8 @@ oom: static void packet_parse_headers(struct sk_buff *skb, struct socket *sock) { - if (!skb->protocol && sock->type == SOCK_RAW) { + if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) && + sock->type == SOCK_RAW) { skb_reset_mac_header(skb); skb->protocol = dev_parse_header_protocol(skb); } |