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Switch to use the new help skb_probe_transport_header() to do the l4 header
probing for untrusted sources. For packets with partial csum, the header should
already been set by skb_partial_csum_set().
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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For untrusted packets with partial checksum, we need to set the transport header
for precise packet length estimation. We can just let skb_pratial_csum_set() to
do this to avoid extra call to skb_flow_dissect() and simplify the caller.
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This formatting issue was introduced with commit
d4ac32365dcbfd341a87eae444c26679f889249a
Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch lets dgram_recvmsg fill in the sockaddr struct in
msg->msg_name with the source address of the packet.
This is used by the userland functions recvmsg and recvfrom to get the
senders address.
[Stefan: Changed from old zigbee legacy tree to mainline]
Signed-off-by: Stephen Röttger <stephen.roettger@zero-entropy.de>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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gso_segs were reset to zero when kernel receive packets from untrusted
source. But we use this zero value to estimate precise packet len which is
wrong. So this patch tries to estimate the correct gso_segs value before using
it in qdisc_pkt_len_init().
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Set the transport header for 1) some drivers (e.g ixgbe needs l4 header to do
atr) 2) precise packet length estimation (introduced in 1def9238) needs l4
header to compute header length.
So this patch first tries to get l4 header for packet socket through
skb_flow_dissect(), and pretend no l4 header if skb_flow_dissect() fails.
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The previous code would just compress the UDP header and send the compressed
UDP header along with the uncompressed one.
Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Sets the sequence number in the frame format. Without this fix, the sequence
number is always set to 0. This makes trafic analysis very hard.
Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Bring-over mac802154_dev_get_dsn() function that was present in the
Linux ZigBee kernel. This function is called by the 6LoWPAN code in
order to properly set the DSN (Data Sequence Number) value in the IEEE
802.15.4 frame.
Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add pr_debug() call in order to debug 6LoWPAN fragmentation and
reassembly.
Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The first fragment, FRAG1, must contain some payload according to the
specs. However, as it is currently written, the first fragment will
remain empty and only contain the 6lowpan headers.
This patch also extracts the transport layer information from the first
fragment. This information is used later on when uncompressing UDP
header.
Thanks to Wolf-Bastian Pöttner for noticing that the offset value was
not properly initialized.
Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The IEEE 802.15.4 standard uses the 0xFFFF short address (2 bytes) for message
broadcasting.
Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This feature is especially important when using fragmentation, because
the reassembly mechanism cannot recover from the loss of a fragment.
Note that some hardware ignore this flag and not will not transmit
acknowledgments even if this is set.
Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This causes a drop of the UDP packet.
Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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address correctly
The current test is not RFC6282 compliant. The same issue has been found
and fixed in Contiki. This patch is basically a port of their fix.
Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When the legacy array rtm_min still exists, the length check within
these functions is covered by rtm_min[RTM_NEWTFILTER],
rtm_min[RTM_NEWQDISC] and rtm_min[RTM_NEWTCLASS].
But after Thomas Graf removed rtm_min several days ago, these checks
are missing. Other doit functions should be OK.
Signed-off-by: Hong Zhiguo <honkiko@gmail.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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packet inspection.
Inspection of upper layer protocol is considered harmful, especially
if it is about ARP or other stateful upper layer protocol; driver
cannot (and should not) have full state of them.
IPv4 over Firewire module used to inspect ARP (both in sending path
and in receiving path), and record peer's GUID, max packet size, max
speed and fifo address. This patch removes such inspection by extending
our "hardware address" definition to include other information as well:
max packet size, max speed and fifo. By doing this, The neighbour
module in networking subsystem can cache them.
Note: As we have started ignoring sspd and max_rec in ARP/NDP, those
information will not be used in the driver when sending.
When a packet is being sent, the IP layer fills our pseudo header with
the extended "hardware address", including GUID and fifo. The driver
can look-up node-id (the real but rather volatile low-level address)
by GUID, and then the module can send the packet to the wire using
parameters provided in the extendedn hardware address.
This approach is realistic because IP over IEEE1394 (RFC2734) and IPv6
over IEEE1394 (RFC3146) share same "hardware address" format
in their address resolution protocols.
Here, extended "hardware address" is defined as follows:
union fwnet_hwaddr {
u8 u[16];
struct {
__be64 uniq_id; /* EUI-64 */
u8 max_rec; /* max packet size */
u8 sspd; /* max speed */
__be16 fifo_hi; /* hi 16bits of FIFO addr */
__be32 fifo_lo; /* lo 32bits of FIFO addr */
} __packed uc;
};
Note that Hardware address is declared as union, so that we can map full
IP address into this, when implementing MCAP (Multicast Cannel Allocation
Protocol) for IPv6, but IP and ARP subsystem do not need to know this
format in detail.
One difference between original ARP (RFC826) and 1394 ARP (RFC2734)
is that 1394 ARP Request/Reply do not contain the target hardware address
field (aka ar$tha). This difference is handled in the ARP subsystem.
CC: Stephan Gatzka <stephan.gatzka@gmail.com>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Use common function get calculate rtnl_link_stats64 stats.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Reuse common ip-tunneling code which is re-factored from GRE
module.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Following patch refactors GRE code into ip tunneling code and GRE
specific code. Common tunneling code is moved to ip_tunnel module.
ip_tunnel module is written as generic library which can be used
by different tunneling implementations.
ip_tunnel module contains following components:
- packet xmit and rcv generic code. xmit flow looks like
(gre_xmit/ipip_xmit)->ip_tunnel_xmit->ip_local_out.
- hash table of all devices.
- lookup for tunnel devices.
- control plane operations like device create, destroy, ioctl, netlink
operations code.
- registration for tunneling modules, like gre, ipip etc.
- define single pcpu_tstats dev->tstats.
- struct tnl_ptk_info added to pass parsed tunnel packet parameters.
ipip.h header is renamed to ip_tunnel.h
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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It's always zero.
Signed-off-by: David S. Miller <davem@davemloft.net>
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ip-header id needs to be incremented even if IP_DF flag is set.
This behaviour was changed in commit 490ab08127cebc25e3a26
(IP_GRE: Fix IP-Identification).
Following patch fixes it so that identification is always
incremented.
Reported-by: Cong Wang <amwang@redhat.com>
Acked-by: Cong Wang <amwang@redhat.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
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This reverts commit d6a8c36dd6f6f06f046e5c61d3fb39b777c3bdc6.
Next commit makes this commit unnecessary.
Acked-by: Cong Wang <amwang@redhat.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This reverts commit 10c0d7ed32b7c273970a20e211c08ab46fea3c26.
Next commit makes this commit unnecessary.
Acked-by: Cong Wang <amwang@redhat.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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If we have defined a sparse port allocation which is non-contiguous and
contains gaps, the code freeing port_names will just stop when it
encouters a first NULL port_names, which is not right, we should iterate
over all possible number of ports (DSA_MAX_PORTS) until we are done.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch factors the freeing of the struct dsa_platform_data
manipulated by the driver identically in two places to a single
function.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Pablo Neira Ayuso says:
====================
The following patchset contains Netfilter/IPVS updates for
your net-next tree, they are:
* Better performance in nfnetlink_queue by avoiding copy from the
packet to netlink message, from Eric Dumazet.
* Remove unnecessary locking in the exit path of ebt_ulog, from Gao Feng.
* Use new function ipv6_iface_scope_id in nf_ct_ipv6, from Hannes Frederic Sowa.
* A couple of sparse fixes for IPVS, from Julian Anastasov.
* Use xor hashing in nfnetlink_queue, as suggested by Eric Dumazet, from
myself.
* Allow to dump expectations per master conntrack via ctnetlink, from myself.
* A couple of cleanups to use PTR_RET in module init path, from Silviu-Mihai
Popescu.
* Remove nf_conntrack module a bit faster if netns are in use, from
Vladimir Davydov.
* Use checksum_partial in ip6t_NPT, from YOSHIFUJI Hideaki.
* Sparse fix for nf_conntrack, from Stephen Hemminger.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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When neither IFF_BRIDGE nor IFF_BRIDGE_PORT is set,
and afspec == NULL but protinfo != NULL, we run into
"if (err == 0) br_ifinfo_notify(RTM_NEWLINK, p);" with
random value in ret.
Thanks to Sergei for pointing out the error in commit comments.
Signed-off-by: Hong Zhiguo <honkiko@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch adds support for registering DSA switches using Device Tree
bindings. Note that we support programming the switch routing table even
though no in-tree user seems to require it. I tested this on Armada 370
with a Marvell 88E6172 (not supported by mainline yet).
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Hello!
After patch 1 got accepted to net-next I will also send a patch to
netfilter-devel to make the corresponding changes to the netfilter
reassembly logic.
Thanks,
Hannes
-- >8 --
[PATCH 2/2] ipv6: implement RFC3168 5.3 (ecn protection) for ipv6 fragmentation handling
This patch also ensures that INET_ECN_CE is propagated if one fragment
had the codepoint set.
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jesper Dangaard Brouer <jbrouer@redhat.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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use by ipv6
This patch just moves some code arround to make the ip4_frag_ecn_table
and IPFRAG_ECN_* constants accessible from the other reassembly engines. I
also renamed ip4_frag_ecn_table to ip_frag_ecn_table.
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jesper Dangaard Brouer <jbrouer@redhat.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch adds a dev_addr_genid for IPv6. The goal is to use it, combined with
dev_base_seq to check if a change occurs during a netlink dump.
If a change is detected, the flag NLM_F_DUMP_INTR is set in the first message
after the dump was interrupted.
Note that only dump of unicast addresses is checked (multicast and anycast are
not checked).
Reported-by: Junwei Zhang <junwei.zhang@6wind.com>
Reported-by: Hongjun Li <hongjun.li@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch takes benefit of dev_addr_genid and dev_base_seq to check if a change
occurs during a netlink dump. If a change is detected, the flag NLM_F_DUMP_INTR
is set in the first message after the dump was interrupted.
Note that seq and prev_seq must be reset between each family in rtnl_dump_all()
because they are specific to each family.
Reported-by: Junwei Zhang <junwei.zhang@6wind.com>
Reported-by: Hongjun Li <hongjun.li@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This is a cut and paste typo. We call ->ref() a second time instead
of ->deref().
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Pull to get the thermal netlink multicast group name fix, otherwise
the assertion added in net-next to netlink to detect that kind of bug
makes systems unbootable for some folks.
Signed-off-by: David S. Miller <davem@davemloft.net>
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!CONFIG_DECNET_ROUTER
Otherwise build fails with CONFIG_DECNET && !CONFIG_DECNET_ROUTER
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
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A long standing problem with TSO is the fact that tcp_tso_should_defer()
rearms the deferred timer, while it should not.
Current code leads to following bad bursty behavior :
20:11:24.484333 IP A > B: . 297161:316921(19760) ack 1 win 119
20:11:24.484337 IP B > A: . ack 263721 win 1117
20:11:24.485086 IP B > A: . ack 265241 win 1117
20:11:24.485925 IP B > A: . ack 266761 win 1117
20:11:24.486759 IP B > A: . ack 268281 win 1117
20:11:24.487594 IP B > A: . ack 269801 win 1117
20:11:24.488430 IP B > A: . ack 271321 win 1117
20:11:24.489267 IP B > A: . ack 272841 win 1117
20:11:24.490104 IP B > A: . ack 274361 win 1117
20:11:24.490939 IP B > A: . ack 275881 win 1117
20:11:24.491775 IP B > A: . ack 277401 win 1117
20:11:24.491784 IP A > B: . 316921:332881(15960) ack 1 win 119
20:11:24.492620 IP B > A: . ack 278921 win 1117
20:11:24.493448 IP B > A: . ack 280441 win 1117
20:11:24.494286 IP B > A: . ack 281961 win 1117
20:11:24.495122 IP B > A: . ack 283481 win 1117
20:11:24.495958 IP B > A: . ack 285001 win 1117
20:11:24.496791 IP B > A: . ack 286521 win 1117
20:11:24.497628 IP B > A: . ack 288041 win 1117
20:11:24.498459 IP B > A: . ack 289561 win 1117
20:11:24.499296 IP B > A: . ack 291081 win 1117
20:11:24.500133 IP B > A: . ack 292601 win 1117
20:11:24.500970 IP B > A: . ack 294121 win 1117
20:11:24.501388 IP B > A: . ack 295641 win 1117
20:11:24.501398 IP A > B: . 332881:351881(19000) ack 1 win 119
While the expected behavior is more like :
20:19:49.259620 IP A > B: . 197601:202161(4560) ack 1 win 119
20:19:49.260446 IP B > A: . ack 154281 win 1212
20:19:49.261282 IP B > A: . ack 155801 win 1212
20:19:49.262125 IP B > A: . ack 157321 win 1212
20:19:49.262136 IP A > B: . 202161:206721(4560) ack 1 win 119
20:19:49.262958 IP B > A: . ack 158841 win 1212
20:19:49.263795 IP B > A: . ack 160361 win 1212
20:19:49.264628 IP B > A: . ack 161881 win 1212
20:19:49.264637 IP A > B: . 206721:211281(4560) ack 1 win 119
20:19:49.265465 IP B > A: . ack 163401 win 1212
20:19:49.265886 IP B > A: . ack 164921 win 1212
20:19:49.266722 IP B > A: . ack 166441 win 1212
20:19:49.266732 IP A > B: . 211281:215841(4560) ack 1 win 119
20:19:49.267559 IP B > A: . ack 167961 win 1212
20:19:49.268394 IP B > A: . ack 169481 win 1212
20:19:49.269232 IP B > A: . ack 171001 win 1212
20:19:49.269241 IP A > B: . 215841:221161(5320) ack 1 win 119
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Van Jacobson <vanj@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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With decnet converted, we can finally get rid of rta_buf and its
computations around it. It also gets rid of the minimal header
length verification since all message handlers do that explicitly
anyway.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
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decnet is the only subsystem left that is relying on the global
netlink attribute buffer rta_buf. It's horrible design and we
want to get rid of it.
This converts all of decnet to do implicit attribute parsing. It
also gets rid of the error prone struct dn_kern_rta.
Yes, the fib_magic() stuff is not pretty.
It's compiled tested but I need someone with appropriate hardware
to test the patch since I don't have access to it.
Cc: linux-decnet-user@lists.sourceforge.net
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Similar to GRE tunnel, UDP tunnel should take care of IP header ID
too.
Cc: Pravin B Shelar <pshelar@nicira.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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According to the previous discussion [1] on netdev list, DaveM insists
we should increase the IP header ID for each segmented packets.
This patch fixes it.
Cc: Pravin B Shelar <pshelar@nicira.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
1. http://marc.info/?t=136384172700001&r=1&w=2
Signed-off-by: David S. Miller <davem@davemloft.net>
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The netlink_diag can be built as a module, just like it's done in
unix sockets.
The core dumping message carries the basic info about netlink sockets:
family, type and protocol, portis, dst_group, dst_portid, state.
Groups can be received as an optional parameter NETLINK_DIAG_GROUPS.
Netlink sockets cab be filtered by protocols.
The socket inode number and cookie is reserved for future per-socket info
retrieving. The per-protocol filtering is also reserved for future by
requiring the sdiag_protocol to be zero.
The file /proc/net/netlink doesn't provide enough information for
dumping netlink sockets. It doesn't provide dst_group, dst_portid,
groups above 32.
v2: fix NETLINK_DIAG_MAX. Now it's equal to the last constant.
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Move a few declarations in a header.
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The cgroup code has been surrounded by ifdef CONFIG_NET_CLS_CGROUP
and CONFIG_NETPRIO_CGROUP.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch implements F-RTO (foward RTO recovery):
When the first retransmission after timeout is acknowledged, F-RTO
sends new data instead of old data. If the next ACK acknowledges
some never-retransmitted data, then the timeout was spurious and the
congestion state is reverted. Otherwise if the next ACK selectively
acknowledges the new data, then the timeout was genuine and the
loss recovery continues. This idea applies to recurring timeouts
as well. While F-RTO sends different data during timeout recovery,
it does not (and should not) change the congestion control.
The implementaion follows the three steps of SACK enhanced algorithm
(section 3) in RFC5682. Step 1 is in tcp_enter_loss(). Step 2 and
3 are in tcp_process_loss(). The basic version is not supported
because SACK enhanced version also works for non-SACK connections.
The new implementation is functionally in parity with the old F-RTO
implementation except the one case where it increases undo events:
In addition to the RFC algorithm, a spurious timeout may be detected
without sending data in step 2, as long as the SACK confirms not
all the original data are dropped. When this happens, the sender
will undo the cwnd and perhaps enter fast recovery instead. This
additional check increases the F-RTO undo events by 5x compared
to the prior implementation on Google Web servers, since the sender
often does not have new data to send for HTTP.
Note F-RTO may detect spurious timeout before Eifel with timestamps
does so.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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