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| author | Martin Blumenstingl <martin.blumenstingl@googlemail.com> | 2015-11-22 17:46:09 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-11-29 22:17:17 -0500 |
| commit | 880621c2605b82eb5af91a2c94223df6f5a3fb64 (patch) | |
| tree | b1a1799ef943f2aa04d35530e47dae15282cb2ab | |
| parent | c9da161c6517ba12154059d3b965c2cbaf16f90f (diff) | |
| download | blackbird-op-linux-880621c2605b82eb5af91a2c94223df6f5a3fb64.tar.gz blackbird-op-linux-880621c2605b82eb5af91a2c94223df6f5a3fb64.zip | |
packet: Allow packets with only a header (but no payload)
Commit 9c7077622dd91 ("packet: make packet_snd fail on len smaller
than l2 header") added validation for the packet size in packet_snd.
This change enforces that every packet needs a header (with at least
hard_header_len bytes) plus a payload with at least one byte. Before
this change the payload was optional.
This fixes PPPoE connections which do not have a "Service" or
"Host-Uniq" configured (which is violating the spec, but is still
widely used in real-world setups). Those are currently failing with the
following message: "pppd: packet size is too short (24 <= 24)"
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/netdevice.h | 3 | ||||
| -rw-r--r-- | net/packet/af_packet.c | 4 |
2 files changed, 4 insertions, 3 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 67bfac1abfc1..3b5d134e945a 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1398,7 +1398,8 @@ enum netdev_priv_flags { * @dma: DMA channel * @mtu: Interface MTU value * @type: Interface hardware type - * @hard_header_len: Hardware header length + * @hard_header_len: Hardware header length, which means that this is the + * minimum size of a packet. * * @needed_headroom: Extra headroom the hardware may need, but not in all * cases can this be guaranteed diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 1cf928fb573e..992396aa635c 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2329,8 +2329,8 @@ static void tpacket_destruct_skb(struct sk_buff *skb) static bool ll_header_truncated(const struct net_device *dev, int len) { /* net device doesn't like empty head */ - if (unlikely(len <= dev->hard_header_len)) { - net_warn_ratelimited("%s: packet size is too short (%d <= %d)\n", + if (unlikely(len < dev->hard_header_len)) { + net_warn_ratelimited("%s: packet size is too short (%d < %d)\n", current->comm, len, dev->hard_header_len); return true; } |
