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  1. 15 7月, 2014 3 次提交
    • C
      net: pppoe: use correct channel MTU when using Multilink PPP · a8a3e41c
      由 Christoph Schulz 提交于 
      The PPP channel MTU is used with Multilink PPP when ppp_mp_explode() (see
ppp_generic module) tries to determine how big a fragment might be. According
to RFC 1661, the MTU excludes the 2-byte PPP protocol field, see the
corresponding comment and code in ppp_mp_explode():

		/*
		 * hdrlen includes the 2-byte PPP protocol field, but the
		 * MTU counts only the payload excluding the protocol field.
		 * (RFC1661 Section 2)
		 */
		mtu = pch->chan->mtu - (hdrlen - 2);

However, the pppoe module *does* include the PPP protocol field in the channel
MTU, which is wrong as it causes the PPP payload to be 1-2 bytes too big under
certain circumstances (one byte if PPP protocol compression is used, two
otherwise), causing the generated Ethernet packets to be dropped. So the pppoe
module has to subtract two bytes from the channel MTU. This error only
manifests itself when using Multilink PPP, as otherwise the channel MTU is not
used anywhere.

In the following, I will describe how to reproduce this bug. We configure two
pppd instances for multilink PPP over two PPPoE links, say eth2 and eth3, with
a MTU of 1492 bytes for each link and a MRRU of 2976 bytes. (This MRRU is
computed by adding the two link MTUs and subtracting the MP header twice, which
is 4 bytes long.) The necessary pppd statements on both sides are "multilink
mtu 1492 mru 1492 mrru 2976". On the client side, we additionally need "plugin
rp-pppoe.so eth2" and "plugin rp-pppoe.so eth3", respectively; on the server
side, we additionally need to start two pppoe-server instances to be able to
establish two PPPoE sessions, one over eth2 and one over eth3. We set the MTU
of the PPP network interface to the MRRU (2976) on both sides of the connection
in order to make use of the higher bandwidth. (If we didn't do that, IP
fragmentation would kick in, which we want to avoid.)

Now we send a ICMPv4 echo request with a payload of 2948 bytes from client to
server over the PPP link. This results in the following network packet:

   2948 (echo payload)
 +    8 (ICMPv4 header)
 +   20 (IPv4 header)
---------------------
   2976 (PPP payload)

These 2976 bytes do not exceed the MTU of the PPP network interface, so the
IP packet is not fragmented. Now the multilink PPP code in ppp_mp_explode()
prepends one protocol byte (0x21 for IPv4), making the packet one byte bigger
than the negotiated MRRU. So this packet would have to be divided in three
fragments. But this does not happen as each link MTU is assumed to be two bytes
larger. So this packet is diveded into two fragments only, one of size 1489 and
one of size 1488. Now we have for that bigger fragment:

   1489 (PPP payload)
 +    4 (MP header)
 +    2 (PPP protocol field for the MP payload (0x3d))
 +    6 (PPPoE header)
--------------------------
   1501 (Ethernet payload)

This packet exceeds the link MTU and is discarded.

If one configures the link MTU on the client side to 1501, one can see the
discarded Ethernet frames with tcpdump running on the client. A

ping -s 2948 -c 1 192.168.15.254

leads to the smaller fragment that is correctly received on the server side:

(tcpdump -vvvne -i eth3 pppoes and ppp proto 0x3d)
52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864),
  length 1514: PPPoE  [ses 0x3] MLPPP (0x003d), length 1494: seq 0x000,
  Flags [end], length 1492

and to the bigger fragment that is not received on the server side:

(tcpdump -vvvne -i eth2 pppoes and ppp proto 0x3d)
52:54:00:70:9e:89 > 52:54:00:5d:6f:b0, ethertype PPPoE S (0x8864),
  length 1515: PPPoE  [ses 0x5] MLPPP (0x003d), length 1495: seq 0x000,
  Flags [begin], length 1493

With the patch below, we correctly obtain three fragments:

52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864),
  length 1514: PPPoE  [ses 0x1] MLPPP (0x003d), length 1494: seq 0x000,
  Flags [begin], length 1492
52:54:00:70:9e:89 > 52:54:00:5d:6f:b0, ethertype PPPoE S (0x8864),
  length 1514: PPPoE  [ses 0x1] MLPPP (0x003d), length 1494: seq 0x000,
  Flags [none], length 1492
52:54:00:ad:87:fd > 52:54:00:79:5c:d0, ethertype PPPoE S (0x8864),
  length 27: PPPoE  [ses 0x1] MLPPP (0x003d), length 7: seq 0x000,
  Flags [end], length 5

And the ICMPv4 echo request is successfully received at the server side:

IP (tos 0x0, ttl 64, id 21925, offset 0, flags [DF], proto ICMP (1),
  length 2976)
    192.168.222.2 > 192.168.15.254: ICMP echo request, id 30530, seq 0,
      length 2956

The bug was introduced in commit c9aa6895
("[PPPOE]: Advertise PPPoE MTU") from the very beginning. This patch applies
to 3.10 upwards but the fix can be applied (with minor modifications) to
kernels as old as 2.6.32.
Signed-off-by: NChristoph Schulz <develop@kristov.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a8a3e41c
    • M
      neigh: sysctl - simplify address calculation of gc_* variables · 9ecf07a1
      由 Mathias Krause 提交于 
      The code in neigh_sysctl_register() relies on a specific layout of
struct neigh_table, namely that the 'gc_*' variables are directly
following the 'parms' member in a specific order. The code, though,
expresses this in the most ugly way.

Get rid of the ugly casts and use the 'tbl' pointer to get a handle to
the table. This way we can refer to the 'gc_*' variables directly.

Similarly seen in the grsecurity patch, written by Brad Spengler.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Cc: Brad Spengler <spender@grsecurity.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9ecf07a1
    • D
      net: sctp: fix information leaks in ulpevent layer · 8f2e5ae4
      由 Daniel Borkmann 提交于 
      While working on some other SCTP code, I noticed that some
structures shared with user space are leaking uninitialized
stack or heap buffer. In particular, struct sctp_sndrcvinfo
has a 2 bytes hole between .sinfo_flags and .sinfo_ppid that
remains unfilled by us in sctp_ulpevent_read_sndrcvinfo() when
putting this into cmsg. But also struct sctp_remote_error
contains a 2 bytes hole that we don't fill but place into a skb
through skb_copy_expand() via sctp_ulpevent_make_remote_error().

Both structures are defined by the IETF in RFC6458:

* Section 5.3.2. SCTP Header Information Structure:

  The sctp_sndrcvinfo structure is defined below:

  struct sctp_sndrcvinfo {
    uint16_t sinfo_stream;
    uint16_t sinfo_ssn;
    uint16_t sinfo_flags;
    <-- 2 bytes hole  -->
    uint32_t sinfo_ppid;
    uint32_t sinfo_context;
    uint32_t sinfo_timetolive;
    uint32_t sinfo_tsn;
    uint32_t sinfo_cumtsn;
    sctp_assoc_t sinfo_assoc_id;
  };

* 6.1.3. SCTP_REMOTE_ERROR:

  A remote peer may send an Operation Error message to its peer.
  This message indicates a variety of error conditions on an
  association. The entire ERROR chunk as it appears on the wire
  is included in an SCTP_REMOTE_ERROR event. Please refer to the
  SCTP specification [RFC4960] and any extensions for a list of
  possible error formats. An SCTP error notification has the
  following format:

  struct sctp_remote_error {
    uint16_t sre_type;
    uint16_t sre_flags;
    uint32_t sre_length;
    uint16_t sre_error;
    <-- 2 bytes hole  -->
    sctp_assoc_t sre_assoc_id;
    uint8_t  sre_data[];
  };

Fix this by setting both to 0 before filling them out. We also
have other structures shared between user and kernel space in
SCTP that contains holes (e.g. struct sctp_paddrthlds), but we
copy that buffer over from user space first and thus don't need
to care about it in that cases.

While at it, we can also remove lengthy comments copied from
the draft, instead, we update the comment with the correct RFC
number where one can look it up.
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8f2e5ae4
  3. 14 7月, 2014 2 次提交
  5. 12 7月, 2014 5 次提交
  7. 11 7月, 2014 3 次提交
  9. 10 7月, 2014 5 次提交
  11. 09 7月, 2014 12 次提交
  13. 08 7月, 2014 10 次提交
    • Y
      tcp: fix false undo corner cases · 6e08d5e3
      由 Yuchung Cheng 提交于 
      The undo code assumes that, upon entering loss recovery, TCP
1) always retransmit something
2) the retransmission never fails locally (e.g., qdisc drop)

so undo_marker is set in tcp_enter_recovery() and undo_retrans is
incremented only when tcp_retransmit_skb() is successful.

When the assumption is broken because TCP's cwnd is too small to
retransmit or the retransmit fails locally. The next (DUP)ACK
would incorrectly revert the cwnd and the congestion state in
tcp_try_undo_dsack() or tcp_may_undo(). Subsequent (DUP)ACKs
may enter the recovery state. The sender repeatedly enter and
(incorrectly) exit recovery states if the retransmits continue to
fail locally while receiving (DUP)ACKs.

The fix is to initialize undo_retrans to -1 and start counting on
the first retransmission. Always increment undo_retrans even if the
retransmissions fail locally because they couldn't cause DSACKs to
undo the cwnd reduction.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6e08d5e3
    • O
      net/mlx4_en: Don't configure the HW vxlan parser when vxlan offloading isn't set · e326f2f1
      由 Or Gerlitz 提交于 
      The add_vxlan_port ndo driver code was wrongly testing whether HW vxlan offloads
are supported by the device instead of checking if they are currently enabled.

This causes the driver to configure the HW parser to conduct matching for vxlan
packets but since no steering rules were set, vxlan packets are dropped on RX.

Fix that by doing the right test, as done in the del_vxlan_port ndo handler.

Fixes: 1b136de1 ('net/mlx4: Implement vxlan ndo calls')
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      e326f2f1
    • D
      igmp: fix the problem when mc leave group · 52ad353a
      由 dingtianhong 提交于 
      The problem was triggered by these steps:

1) create socket, bind and then setsockopt for add mc group.
   mreq.imr_multiaddr.s_addr = inet_addr("255.0.0.37");
   mreq.imr_interface.s_addr = inet_addr("192.168.1.2");
   setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq));

2) drop the mc group for this socket.
   mreq.imr_multiaddr.s_addr = inet_addr("255.0.0.37");
   mreq.imr_interface.s_addr = inet_addr("0.0.0.0");
   setsockopt(sockfd, IPPROTO_IP, IP_DROP_MEMBERSHIP, &mreq, sizeof(mreq));

3) and then drop the socket, I found the mc group was still used by the dev:

   netstat -g

   Interface       RefCnt Group
   --------------- ------ ---------------------
   eth2		   1	  255.0.0.37

Normally even though the IP_DROP_MEMBERSHIP return error, the mc group still need
to be released for the netdev when drop the socket, but this process was broken when
route default is NULL, the reason is that:

The ip_mc_leave_group() will choose the in_dev by the imr_interface.s_addr, if input addr
is NULL, the default route dev will be chosen, then the ifindex is got from the dev,
then polling the inet->mc_list and return -ENODEV, but if the default route dev is NULL,
the in_dev and ifIndex is both NULL, when polling the inet->mc_list, the mc group will be
released from the mc_list, but the dev didn't dec the refcnt for this mc group, so
when dropping the socket, the mc_list is NULL and the dev still keep this group.

v1->v2: According Hideaki's suggestion, we should align with IPv6 (RFC3493) and BSDs,
	so I add the checking for the in_dev before polling the mc_list, make sure when
	we remove the mc group, dec the refcnt to the real dev which was using the mc address.
	The problem would never happened again.
Signed-off-by: NDing Tianhong <dingtianhong@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      52ad353a
    • L
      net: Fix NETDEV_CHANGE notifier usage causing spurious arp flush · 54951194
      由 Loic Prylli 提交于 
      A bug was introduced in NETDEV_CHANGE notifier sequence causing the
arp table to be sometimes spuriously cleared (including manual arp
entries marked permanent), upon network link carrier changes.

The changed argument for the notifier was applied only to a single
caller of NETDEV_CHANGE, missing among others netdev_state_change().
So upon net_carrier events induced by the network, which are
triggering a call to netdev_state_change(), arp_netdev_event() would
decide whether to clear or not arp cache based on random/junk stack
values (a kind of read buffer overflow).

Fixes: be9efd36 ("net: pass changed flags along with NETDEV_CHANGE event")
Fixes: 6c8b4e3f ("arp: flush arp cache on IFF_NOARP change")
Signed-off-by: NLoic Prylli <loicp@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      54951194
    • B
      net: qmi_wwan: Add ID for Telewell TW-LTE 4G v2 · 8dcb4b15
      由 Bernd Wachter 提交于 
      There's a new version of the Telewell 4G modem working with, but not
recognized by this driver.
Signed-off-by: NBernd Wachter <bernd.wachter@jolla.com>
Acked-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8dcb4b15
    • D
      Revert "net: stmmac: add platform init/exit for Altera's ARM socfpga" · 26a9ebca
      由 David S. Miller 提交于 
      This reverts commit 0acf1676.

Breaks the build due to missing reference to phy_resume in
the resulting dwmac-socfpga.o object.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      26a9ebca
    • Z
      powerpc/ucc_geth: deal with a compile warning · 8844a006
      由 Zhao Qiang 提交于 
      deal with a compile warning: comparison between
'enum qe_fltr_largest_external_tbl_lookup_key_size'
and 'enum qe_fltr_tbl_lookup_key_size'

the code:
	"if (ug_info->largestexternallookupkeysize ==
	     QE_FLTR_TABLE_LOOKUP_KEY_SIZE_8_BYTES)"
is warned because different enum, so modify it.

	"enum qe_fltr_largest_external_tbl_lookup_key_size
	             largestexternallookupkeysize;

	enum qe_fltr_tbl_lookup_key_size {
		 QE_FLTR_TABLE_LOOKUP_KEY_SIZE_8_BYTES
			 = 0x3f,         /* LookupKey parsed by the Generate LookupKey
					    CMD is truncated to 8 bytes */
		 QE_FLTR_TABLE_LOOKUP_KEY_SIZE_16_BYTES
			 = 0x5f,         /* LookupKey parsed by the Generate LookupKey
					    CMD is truncated to 16 bytes */
	 };

	 /* QE FLTR extended filtering Largest External Table Lookup Key Size */
	 enum qe_fltr_largest_external_tbl_lookup_key_size {
		 QE_FLTR_LARGEST_EXTERNAL_TABLE_LOOKUP_KEY_SIZE_NONE
			 = 0x0,/* not used */
		 QE_FLTR_LARGEST_EXTERNAL_TABLE_LOOKUP_KEY_SIZE_8_BYTES
			 = QE_FLTR_TABLE_LOOKUP_KEY_SIZE_8_BYTES,        /* 8 bytes */
		 QE_FLTR_LARGEST_EXTERNAL_TABLE_LOOKUP_KEY_SIZE_16_BYTES
			 = QE_FLTR_TABLE_LOOKUP_KEY_SIZE_16_BYTES,       /* 16 bytes */
	 };"
Signed-off-by: NZhao Qiang <B45475@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8844a006
    • D
      Merge branch 'net_ovs_fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/pshelar/openvswitch · edc1bb0b
      由 David S. Miller 提交于 
      Pravin B Shelar says:

====================
Open vSwitch

A set of fixes for net.
First bug is related flow-table management.  Second one is in sample
action. Third is related flow stats and last one add gre-err handler for ovs.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      edc1bb0b
    • T
      net: Performance fix for process_backlog · 11ef7a89
      由 Tom Herbert 提交于 
      In process_backlog the input_pkt_queue is only checked once for new
packets and quota is artificially reduced to reflect precisely the
number of packets on the input_pkt_queue so that the loop exits
appropriately.

This patches changes the behavior to be more straightforward and
less convoluted. Packets are processed until either the quota
is met or there are no more packets to process.

This patch seems to provide a small, but noticeable performance
improvement. The performance improvement is a result of staying
in the process_backlog loop longer which can reduce number of IPI's.

Performance data using super_netperf TCP_RR with 200 flows:

Before fix:

88.06% CPU utilization
125/190/309 90/95/99% latencies
1.46808e+06 tps
1145382 intrs.sec.

With fix:

87.73% CPU utilization
122/183/296 90/95/99% latencies
1.4921e+06 tps
1021674.30 intrs./sec.
Signed-off-by: NTom Herbert <therbert@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      11ef7a89
    • E
      ipv4: icmp: Fix pMTU handling for rare case · 68b7107b
      由 Edward Allcutt 提交于 
      Some older router implementations still send Fragmentation Needed
errors with the Next-Hop MTU field set to zero. This is explicitly
described as an eventuality that hosts must deal with by the
standard (RFC 1191) since older standards specified that those
bits must be zero.

Linux had a generic (for all of IPv4) implementation of the algorithm
described in the RFC for searching a list of MTU plateaus for a good
value. Commit 46517008 ("ipv4: Kill ip_rt_frag_needed().")
removed this as part of the changes to remove the routing cache.
Subsequently any Fragmentation Needed packet with a zero Next-Hop
MTU has been discarded without being passed to the per-protocol
handlers or notifying userspace for raw sockets.

When there is a router which does not implement RFC 1191 on an
MTU limited path then this results in stalled connections since
large packets are discarded and the local protocols are not
notified so they never attempt to lower the pMTU.

One example I have seen is an OpenBSD router terminating IPSec
tunnels. It's worth pointing out that this case is distinct from
the BSD 4.2 bug which incorrectly calculated the Next-Hop MTU
since the commit in question dismissed that as a valid concern.

All of the per-protocols handlers implement the simple approach from
RFC 1191 of immediately falling back to the minimum value. Although
this is sub-optimal it is vastly preferable to connections hanging
indefinitely.

Remove the Next-Hop MTU != 0 check and allow such packets
to follow the normal path.

Fixes: 46517008 ("ipv4: Kill ip_rt_frag_needed().")
Signed-off-by: NEdward Allcutt <edward.allcutt@openmarket.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      68b7107b