1. 12 5月, 2017 3 次提交
    • E
      netem: fix skb_orphan_partial() · f6ba8d33
      Eric Dumazet 提交于
      I should have known that lowering skb->truesize was dangerous :/
      
      In case packets are not leaving the host via a standard Ethernet device,
      but looped back to local sockets, bad things can happen, as reported
      by Michael Madsen ( https://bugzilla.kernel.org/show_bug.cgi?id=195713 )
      
      So instead of tweaking skb->truesize, lets change skb->destructor
      and keep a reference on the owner socket via its sk_refcnt.
      
      Fixes: f2f872f9 ("netem: Introduce skb_orphan_partial() helper")
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Reported-by: NMichael Madsen <mkm@nabto.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f6ba8d33
    • D
      xdp: refine xdp api with regards to generic xdp · d67b9cd2
      Daniel Borkmann 提交于
      While working on the iproute2 generic XDP frontend, I noticed that
      as of right now it's possible to have native *and* generic XDP
      programs loaded both at the same time for the case when a driver
      supports native XDP.
      
      The intended model for generic XDP from b5cdae32 ("net: Generic
      XDP") is, however, that only one out of the two can be present at
      once which is also indicated as such in the XDP netlink dump part.
      The main rationale for generic XDP is to ease accessibility (in
      case a driver does not yet have XDP support) and to generically
      provide a semantical model as an example for driver developers
      wanting to add XDP support. The generic XDP option for an XDP
      aware driver can still be useful for comparing and testing both
      implementations.
      
      However, it is not intended to have a second XDP processing stage
      or layer with exactly the same functionality of the first native
      stage. Only reason could be to have a partial fallback for future
      XDP features that are not supported yet in the native implementation
      and we probably also shouldn't strive for such fallback and instead
      encourage native feature support in the first place. Given there's
      currently no such fallback issue or use case, lets not go there yet
      if we don't need to.
      
      Therefore, change semantics for loading XDP and bail out if the
      user tries to load a generic XDP program when a native one is
      present and vice versa. Another alternative to bailing out would
      be to handle the transition from one flavor to another gracefully,
      but that would require to bring the device down, exchange both
      types of programs, and bring it up again in order to avoid a tiny
      window where a packet could hit both hooks. Given this complicates
      the logic for just a debugging feature in the native case, I went
      with the simpler variant.
      
      For the dump, remove IFLA_XDP_FLAGS that was added with b5cdae32
      and reuse IFLA_XDP_ATTACHED for indicating the mode. Dumping all
      or just a subset of flags that were used for loading the XDP prog
      is suboptimal in the long run since not all flags are useful for
      dumping and if we start to reuse the same flag definitions for
      load and dump, then we'll waste bit space. What we really just
      want is to dump the mode for now.
      
      Current IFLA_XDP_ATTACHED semantics are: nothing was installed (0),
      a program is running at the native driver layer (1). Thus, add a
      mode that says that a program is running at generic XDP layer (2).
      Applications will handle this fine in that older binaries will
      just indicate that something is attached at XDP layer, effectively
      this is similar to IFLA_XDP_FLAGS attr that we would have had
      modulo the redundancy.
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d67b9cd2
    • D
      xdp: add flag to enforce driver mode · 0489df9a
      Daniel Borkmann 提交于
      After commit b5cdae32 ("net: Generic XDP") we automatically fall
      back to a generic XDP variant if the driver does not support native
      XDP. Allow for an option where the user can specify that always the
      native XDP variant should be selected and in case it's not supported
      by a driver, just bail out.
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0489df9a
  2. 09 5月, 2017 2 次提交
  3. 06 5月, 2017 1 次提交
    • E
      tcp: randomize timestamps on syncookies · 84b114b9
      Eric Dumazet 提交于
      Whole point of randomization was to hide server uptime, but an attacker
      can simply start a syn flood and TCP generates 'old style' timestamps,
      directly revealing server jiffies value.
      
      Also, TSval sent by the server to a particular remote address vary
      depending on syncookies being sent or not, potentially triggering PAWS
      drops for innocent clients.
      
      Lets implement proper randomization, including for SYNcookies.
      
      Also we do not need to export sysctl_tcp_timestamps, since it is not
      used from a module.
      
      In v2, I added Florian feedback and contribution, adding tsoff to
      tcp_get_cookie_sock().
      
      v3 removed one unused variable in tcp_v4_connect() as Florian spotted.
      
      Fixes: 95a22cae ("tcp: randomize tcp timestamp offsets for each connection")
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Reviewed-by: NFlorian Westphal <fw@strlen.de>
      Tested-by: NFlorian Westphal <fw@strlen.de>
      Cc: Yuchung Cheng <ycheng@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      84b114b9
  4. 04 5月, 2017 1 次提交
  5. 02 5月, 2017 2 次提交
  6. 01 5月, 2017 4 次提交
  7. 29 4月, 2017 1 次提交
  8. 28 4月, 2017 2 次提交
  9. 27 4月, 2017 1 次提交
  10. 26 4月, 2017 1 次提交
    • D
      net: Generic XDP · b5cdae32
      David S. Miller 提交于
      This provides a generic SKB based non-optimized XDP path which is used
      if either the driver lacks a specific XDP implementation, or the user
      requests it via a new IFLA_XDP_FLAGS value named XDP_FLAGS_SKB_MODE.
      
      It is arguable that perhaps I should have required something like
      this as part of the initial XDP feature merge.
      
      I believe this is critical for two reasons:
      
      1) Accessibility.  More people can play with XDP with less
         dependencies.  Yes I know we have XDP support in virtio_net, but
         that just creates another depedency for learning how to use this
         facility.
      
         I wrote this to make life easier for the XDP newbies.
      
      2) As a model for what the expected semantics are.  If there is a pure
         generic core implementation, it serves as a semantic example for
         driver folks adding XDP support.
      
      One thing I have not tried to address here is the issue of
      XDP_PACKET_HEADROOM, thanks to Daniel for spotting that.  It seems
      incredibly expensive to do a skb_cow(skb, XDP_PACKET_HEADROOM) or
      whatever even if the XDP program doesn't try to push headers at all.
      I think we really need the verifier to somehow propagate whether
      certain XDP helpers are used or not.
      
      v5:
       - Handle both negative and positive offset after running prog
       - Fix mac length in XDP_TX case (Alexei)
       - Use rcu_dereference_protected() in free_netdev (kbuild test robot)
      
      v4:
       - Fix MAC header adjustmnet before calling prog (David Ahern)
       - Disable LRO when generic XDP is installed (Michael Chan)
       - Bypass qdisc et al. on XDP_TX and record the event (Alexei)
       - Do not perform generic XDP on reinjected packets (DaveM)
      
      v3:
       - Make sure XDP program sees packet at MAC header, push back MAC
         header if we do XDP_TX.  (Alexei)
       - Elide GRO when generic XDP is in use.  (Alexei)
       - Add XDP_FLAG_SKB_MODE flag which the user can use to request generic
         XDP even if the driver has an XDP implementation.  (Alexei)
       - Report whether SKB mode is in use in rtnl_xdp_fill() via XDP_FLAGS
         attribute.  (Daniel)
      
      v2:
       - Add some "fall through" comments in switch statements based
         upon feedback from Andrew Lunn
       - Use RCU for generic xdp_prog, thanks to Johannes Berg.
      Tested-by: NAndy Gospodarek <andy@greyhouse.net>
      Tested-by: NJesper Dangaard Brouer <brouer@redhat.com>
      Tested-by: NDavid Ahern <dsa@cumulusnetworks.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b5cdae32
  11. 25 4月, 2017 2 次提交
  12. 23 4月, 2017 1 次提交
  13. 22 4月, 2017 4 次提交
    • T
      netpoll: Check for skb->queue_mapping · c70b17b7
      Tushar Dave 提交于
      Reducing real_num_tx_queues needs to be in sync with skb queue_mapping
      otherwise skbs with queue_mapping greater than real_num_tx_queues
      can be sent to the underlying driver and can result in kernel panic.
      
      One such event is running netconsole and enabling VF on the same
      device. Or running netconsole and changing number of tx queues via
      ethtool on same device.
      
      e.g.
      Unable to handle kernel NULL pointer dereference
      tsk->{mm,active_mm}->context = 0000000000001525
      tsk->{mm,active_mm}->pgd = fff800130ff9a000
                    \|/ ____ \|/
                    "@'/ .. \`@"
                    /_| \__/ |_\
                       \__U_/
      kworker/48:1(475): Oops [#1]
      CPU: 48 PID: 475 Comm: kworker/48:1 Tainted: G           OE
      4.11.0-rc3-davem-net+ #7
      Workqueue: events queue_process
      task: fff80013113299c0 task.stack: fff800131132c000
      TSTATE: 0000004480e01600 TPC: 00000000103f9e3c TNPC: 00000000103f9e40 Y:
      00000000    Tainted: G           OE
      TPC: <ixgbe_xmit_frame_ring+0x7c/0x6c0 [ixgbe]>
      g0: 0000000000000000 g1: 0000000000003fff g2: 0000000000000000 g3:
      0000000000000001
      g4: fff80013113299c0 g5: fff8001fa6808000 g6: fff800131132c000 g7:
      00000000000000c0
      o0: fff8001fa760c460 o1: fff8001311329a50 o2: fff8001fa7607504 o3:
      0000000000000003
      o4: fff8001f96e63a40 o5: fff8001311d77ec0 sp: fff800131132f0e1 ret_pc:
      000000000049ed94
      RPC: <set_next_entity+0x34/0xb80>
      l0: 0000000000000000 l1: 0000000000000800 l2: 0000000000000000 l3:
      0000000000000000
      l4: 000b2aa30e34b10d l5: 0000000000000000 l6: 0000000000000000 l7:
      fff8001fa7605028
      i0: fff80013111a8a00 i1: fff80013155a0780 i2: 0000000000000000 i3:
      0000000000000000
      i4: 0000000000000000 i5: 0000000000100000 i6: fff800131132f1a1 i7:
      00000000103fa4b0
      I7: <ixgbe_xmit_frame+0x30/0xa0 [ixgbe]>
      Call Trace:
       [00000000103fa4b0] ixgbe_xmit_frame+0x30/0xa0 [ixgbe]
       [0000000000998c74] netpoll_start_xmit+0xf4/0x200
       [0000000000998e10] queue_process+0x90/0x160
       [0000000000485fa8] process_one_work+0x188/0x480
       [0000000000486410] worker_thread+0x170/0x4c0
       [000000000048c6b8] kthread+0xd8/0x120
       [0000000000406064] ret_from_fork+0x1c/0x2c
       [0000000000000000]           (null)
      Disabling lock debugging due to kernel taint
      Caller[00000000103fa4b0]: ixgbe_xmit_frame+0x30/0xa0 [ixgbe]
      Caller[0000000000998c74]: netpoll_start_xmit+0xf4/0x200
      Caller[0000000000998e10]: queue_process+0x90/0x160
      Caller[0000000000485fa8]: process_one_work+0x188/0x480
      Caller[0000000000486410]: worker_thread+0x170/0x4c0
      Caller[000000000048c6b8]: kthread+0xd8/0x120
      Caller[0000000000406064]: ret_from_fork+0x1c/0x2c
      Caller[0000000000000000]:           (null)
      Signed-off-by: NTushar Dave <tushar.n.dave@oracle.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c70b17b7
    • D
      bpf: add napi_id read access to __sk_buff · b1d9fc41
      Daniel Borkmann 提交于
      Add napi_id access to __sk_buff for socket filter program types, tc
      program types and other bpf_convert_ctx_access() users. Having access
      to skb->napi_id is useful for per RX queue listener siloing, f.e.
      in combination with SO_ATTACH_REUSEPORT_EBPF and when busy polling is
      used, meaning SO_REUSEPORT enabled listeners can then select the
      corresponding socket at SYN time already [1]. The skb is marked via
      skb_mark_napi_id() early in the receive path (e.g., napi_gro_receive()).
      
      Currently, sockets can only use SO_INCOMING_NAPI_ID from 6d433902
      ("net: Introduce SO_INCOMING_NAPI_ID") as a socket option to look up
      the NAPI ID associated with the queue for steering, which requires a
      prior sk_mark_napi_id() after the socket was looked up.
      
      Semantics for the __sk_buff napi_id access are similar, meaning if
      skb->napi_id is < MIN_NAPI_ID (e.g. outgoing packets using sender_cpu),
      then an invalid napi_id of 0 is returned to the program, otherwise a
      valid non-zero napi_id.
      
        [1] http://netdevconf.org/2.1/slides/apr6/dumazet-BUSY-POLLING-Netdev-2.1.pdfSuggested-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b1d9fc41
    • I
      gso: Validate assumption of frag_list segementation · 43170c4e
      Ilan Tayari 提交于
      Commit 07b26c94 ("gso: Support partial splitting at the frag_list
      pointer") assumes that all SKBs in a frag_list (except maybe the last
      one) contain the same amount of GSO payload.
      
      This assumption is not always correct, resulting in the following
      warning message in the log:
          skb_segment: too many frags
      
      For example, mlx5 driver in Striding RQ mode creates some RX SKBs with
      one frag, and some with 2 frags.
      After GRO, the frag_list SKBs end up having different amounts of payload.
      If this frag_list SKB is then forwarded, the aforementioned assumption
      is violated.
      
      Validate the assumption, and fall back to software GSO if it not true.
      
      Change-Id: Ia03983f4a47b6534dd987d7a2aad96d54d46d212
      Fixes: 07b26c94 ("gso: Support partial splitting at the frag_list pointer")
      Signed-off-by: NIlan Tayari <ilant@mellanox.com>
      Signed-off-by: NIlya Lesokhin <ilyal@mellanox.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      43170c4e
    • M
      Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning · 7acf8a1e
      Matthew Whitehead 提交于
      Constants used for tuning are generally a bad idea, especially as hardware
      changes over time. Replace the constant 2 jiffies with sysctl variable
      netdev_budget_usecs to enable sysadmins to tune the softirq processing.
      Also document the variable.
      
      For example, a very fast machine might tune this to 1000 microseconds,
      while my regression testing 486DX-25 needs it to be 4000 microseconds on
      a nearly idle network to prevent time_squeeze from being incremented.
      
      Version 2: changed jiffies to microseconds for predictable units.
      Signed-off-by: NMatthew Whitehead <tedheadster@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7acf8a1e
  14. 21 4月, 2017 1 次提交
  15. 18 4月, 2017 4 次提交
    • D
      net: rtnetlink: plumb extended ack to doit function · c21ef3e3
      David Ahern 提交于
      Add netlink_ext_ack arg to rtnl_doit_func. Pass extack arg to nlmsg_parse
      for doit functions that call it directly.
      
      This is the first step to using extended error reporting in rtnetlink.
      >From here individual subsystems can be updated to set netlink_ext_ack as
      needed.
      Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c21ef3e3
    • I
      gso: Validate assumption of frag_list segementation · 7a7a9bd7
      Ilan Tayari 提交于
      Commit 07b26c94 ("gso: Support partial splitting at the frag_list
      pointer") assumes that all SKBs in a frag_list (except maybe the last
      one) contain the same amount of GSO payload.
      
      This assumption is not always correct, resulting in the following
      warning message in the log:
          skb_segment: too many frags
      
      For example, mlx5 driver in Striding RQ mode creates some RX SKBs with
      one frag, and some with 2 frags.
      After GRO, the frag_list SKBs end up having different amounts of payload.
      If this frag_list SKB is then forwarded, the aforementioned assumption
      is violated.
      
      Validate the assumption, and fall back to software GSO if it not true.
      
      Fixes: 07b26c94 ("gso: Support partial splitting at the frag_list pointer")
      Signed-off-by: NIlan Tayari <ilant@mellanox.com>
      Signed-off-by: NIlya Lesokhin <ilyal@mellanox.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7a7a9bd7
    • C
      Add uid and cookie bpf helper to cg_skb_func_proto · 9fd0f315
      Chenbo Feng 提交于
      BPF helper functions get_socket_cookie and get_socket_uid can be
      used for network traffic classifications, among others. Expose
      them also to programs of type BPF_PROG_TYPE_CGROUP_SKB. As of
      commit 8f917bba ("bpf: pass sk to helper functions") the
      required skb->sk function is available at both cgroup bpf ingress
      and egress hooks. With these two new helper, cg_skb_func_proto is
      effectively the same as sk_filter_func_proto.
      
      Change since V1:
      Instead of add the helper to cg_skb_func_proto, redirect the
      cg_skb_func_proto to sk_filter_func_proto since all helper function
      in sk_filter_func_proto are applicable to cg_skb_func_proto now.
      Signed-off-by: NChenbo Feng <fengc@google.com>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9fd0f315
    • W
      net-timestamp: avoid use-after-free in ip_recv_error · 1862d620
      Willem de Bruijn 提交于
      Syzkaller reported a use-after-free in ip_recv_error at line
      
          info->ipi_ifindex = skb->dev->ifindex;
      
      This function is called on dequeue from the error queue, at which
      point the device pointer may no longer be valid.
      
      Save ifindex on enqueue in __skb_complete_tx_timestamp, when the
      pointer is valid or NULL. Store it in temporary storage skb->cb.
      
      It is safe to reference skb->dev here, as called from device drivers
      or dev_queue_xmit. The exception is when called from tcp_ack_tstamp;
      in that case it is NULL and ifindex is set to 0 (invalid).
      
      Do not return a pktinfo cmsg if ifindex is 0. This maintains the
      current behavior of not returning a cmsg if skb->dev was NULL.
      
      On dequeue, the ipv4 path will cast from sock_exterr_skb to
      in_pktinfo. Both have ifindex as their first element, so no explicit
      conversion is needed. This is by design, introduced in commit
      0b922b7a ("net: original ingress device index in PKTINFO"). For
      ipv6 ip6_datagram_support_cmsg converts to in6_pktinfo.
      
      Fixes: 829ae9d6 ("net-timestamp: allow reading recv cmsg on errqueue with origin tstamp")
      Reported-by: NAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: NWillem de Bruijn <willemb@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1862d620
  16. 15 4月, 2017 1 次提交
  17. 14 4月, 2017 9 次提交