This cleanup patch puts struct/union/enum opening braces,
in first line to ease grep games.
struct something
{
becomes :
struct something {
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add Ancilliary data to better represent loss information
I've had a few requests recently to provide more detail regarding frame loss
during an AF_PACKET packet capture session. Specifically the requestors want to
see where in a packet sequence frames were lost, i.e. they want to see that 40
frames were lost between frames 302 and 303 in a packet capture file. In order
to do this we need:
1) The kernel to export this data to user space
2) The applications to make use of it
This patch addresses item (1). It does this by doing the following:
A) Anytime we drop a frame for which we would increment po->stats.tp_drops, we
also no increment a stats called po->stats.tp_gap.
B) Every time we successfully enqueue a frame to sk_receive_queue, we record the
value of po->stats.tp_gap in skb->mark. skb->cb would nominally be the place to
record this, but since all the space there is used up, we're overloading
skb->mark. Its safe to do since any enqueued packet is guaranteed to be
unshared at this point, and skb->mark isn't used for anything else in the rx
path to the application. After we record tp_gap in the skb, we zero
po->stats.tp_gap. This allows us to keep a counter of the number of frames lost
between any two enqueued packets
C) When the application goes to dequeue a frame from the packet socket, we look
at skb->mark for that frame. If it is non-zero, we add a cmsg chunk to the
msghdr of level SOL_PACKET and type PACKET_GAPDATA. Its a 32 bit integer that
represents the number of frames lost between this packet and the last previous
frame received.
Note there is a chance that if there is frame loss after a receive, and then the
socket is closed, some gap data might be lost. This is covered by the use of
the PACKET_AUXDATA socket option, which gives total loss data. With a bit of
math, the final gap can be determined that way.
I've tested this patch myself, and it works well.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
include/linux/if_packet.h | 2 ++
net/packet/af_packet.c | 33 +++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
Signed-off-by: David S. Miller <davem@davemloft.net>
The the PACKET_ADD_MEMBERSHIP and the PACKET_DROP_MEMBERSHIP setsockopt
calls for af_packet already has all of the infrastructure needed to subscribe
to multiple mac addresses. All that is missing is a flag to say that
the address we want to listen on is a unicast address.
So introduce PACKET_MR_UNICAST and wire it up to dev_unicast_add and
dev_unicast_delete.
Additionally I noticed that errors from dev_mc_add were not propagated
from packet_dev_mc so fix that.
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
New packet socket feature that makes packet socket more efficient for
transmission.
- It reduces number of system call through a PACKET_TX_RING mechanism,
based on PACKET_RX_RING (Circular buffer allocated in kernel space
which is mmapped from user space).
- It minimizes CPU copy using fragmented SKB (almost zero copy).
Signed-off-by: Johann Baudy <johann.baudy@gnu-log.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add new sockopt to reserve some headroom in the mmaped ring frames in
front of the packet payload. This can be used f.i. when the VLAN header
needs to be (re)constructed to avoid moving the entire payload.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Store the VLAN tag in the auxillary data/tpacket2_hdr so userspace can
properly deal with hardware VLAN tagging/stripping.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The tpacket_hdr is not 64 bit clean due to use of an unsigned long
and can't be extended because the following struct sockaddr_ll needs
to be at a fixed offset.
Add support for a version 2 tpacket protocol that removes these
limitations.
Userspace can query the header size through a new getsockopt option
and change the protocol version through a setsockopt option. The
changes needed to switch to the new protocol version are:
1. replace struct tpacket_hdr by struct tpacket2_hdr
2. query header len and save
3. set protocol version to 2
- set up ring as usual
4. for getting the sockaddr_ll, use (void *)hdr + TPACKET_ALIGN(hdrlen)
instead of (void *)hdr + TPACKET_ALIGN(sizeof(struct tpacket_hdr))
Steps 2 and 4 can be omitted if the struct sockaddr_ll isn't needed.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a packet socket option to allow the orig_dev index to be returned
to userspace when passing traffic through a decapsulated device, such
as the bonding driver.
This is very useful for layer 2 traffic being able to report which
physical device actually received the traffic, instead of having the
encapsulating device hide that information.
The new option is called PACKET_ORIGDEV.
Signed-off-by: Peter P. Waskiewicz Jr. <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is needed to make ISC's DHCP server (and probably other
DHCP servers/clients using AF_PACKET) to be able to serve another
client on the same Xen host.
The problem is that packets between different domains on the same
Xen host only have partial checksums. Unfortunately this piece of
information is not passed along in AF_PACKET unless you're using
the mmap interface. Since dhcpd doesn't support packet-mmap, UDP
packets from the same host come out with apparently bogus checksums.
This patch adds a mechanism for AF_PACKET recvmsg(2) to return the
status along with the packet. It does so by adding a new cmsg that
contains this information along with some other relevant data such
as the original packet length.
I didn't include the time stamp information since there is already
a cmsg for that.
This patch also changes the mmap code to set the CSUMNOTREADY flag
on all packets instead of just outoing packets on cooked sockets.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Weirdness: the third argument of socket() is net-endian
here. Oh, well - it's documented in packet(7).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Eric Dumazet