1. 22 10月, 2015 1 次提交
  2. 21 10月, 2015 4 次提交
    • Y
      tcp: track the packet timings in RACK · 659a8ad5
      Yuchung Cheng 提交于
      This patch is the first half of the RACK loss recovery.
      
      RACK loss recovery uses the notion of time instead
      of packet sequence (FACK) or counts (dupthresh). It's inspired by the
      previous FACK heuristic in tcp_mark_lost_retrans(): when a limited
      transmit (new data packet) is sacked, then current retransmitted
      sequence below the newly sacked sequence must been lost,
      since at least one round trip time has elapsed.
      
      But it has several limitations:
      1) can't detect tail drops since it depends on limited transmit
      2) is disabled upon reordering (assumes no reordering)
      3) only enabled in fast recovery ut not timeout recovery
      
      RACK (Recently ACK) addresses these limitations with the notion
      of time instead: a packet P1 is lost if a later packet P2 is s/acked,
      as at least one round trip has passed.
      
      Since RACK cares about the time sequence instead of the data sequence
      of packets, it can detect tail drops when later retransmission is
      s/acked while FACK or dupthresh can't. For reordering RACK uses a
      dynamically adjusted reordering window ("reo_wnd") to reduce false
      positives on ever (small) degree of reordering.
      
      This patch implements tcp_advanced_rack() which tracks the
      most recent transmission time among the packets that have been
      delivered (ACKed or SACKed) in tp->rack.mstamp. This timestamp
      is the key to determine which packet has been lost.
      
      Consider an example that the sender sends six packets:
      T1: P1 (lost)
      T2: P2
      T3: P3
      T4: P4
      T100: sack of P2. rack.mstamp = T2
      T101: retransmit P1
      T102: sack of P2,P3,P4. rack.mstamp = T4
      T205: ACK of P4 since the hole is repaired. rack.mstamp = T101
      
      We need to be careful about spurious retransmission because it may
      falsely advance tp->rack.mstamp by an RTT or an RTO, causing RACK
      to falsely mark all packets lost, just like a spurious timeout.
      
      We identify spurious retransmission by the ACK's TS echo value.
      If TS option is not applicable but the retransmission is acknowledged
      less than min-RTT ago, it is likely to be spurious. We refrain from
      using the transmission time of these spurious retransmissions.
      
      The second half is implemented in the next patch that marks packet
      lost using RACK timestamp.
      Signed-off-by: NYuchung Cheng <ycheng@google.com>
      Signed-off-by: NNeal Cardwell <ncardwell@google.com>
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      659a8ad5
    • Y
      tcp: skb_mstamp_after helper · 625a5e10
      Yuchung Cheng 提交于
      a helper to prepare the first main RACK patch.
      Signed-off-by: NYuchung Cheng <ycheng@google.com>
      Signed-off-by: NNeal Cardwell <ncardwell@google.com>
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      625a5e10
    • Y
      tcp: remove tcp_mark_lost_retrans() · af82f4e8
      Yuchung Cheng 提交于
      Remove the existing lost retransmit detection because RACK subsumes
      it completely. This also stops the overloading the ack_seq field of
      the skb control block.
      Signed-off-by: NYuchung Cheng <ycheng@google.com>
      Signed-off-by: NNeal Cardwell <ncardwell@google.com>
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      af82f4e8
    • Y
      tcp: track min RTT using windowed min-filter · f6722583
      Yuchung Cheng 提交于
      Kathleen Nichols' algorithm for tracking the minimum RTT of a
      data stream over some measurement window. It uses constant space
      and constant time per update. Yet it almost always delivers
      the same minimum as an implementation that has to keep all
      the data in the window. The measurement window is tunable via
      sysctl.net.ipv4.tcp_min_rtt_wlen with a default value of 5 minutes.
      
      The algorithm keeps track of the best, 2nd best & 3rd best min
      values, maintaining an invariant that the measurement time of
      the n'th best >= n-1'th best. It also makes sure that the three
      values are widely separated in the time window since that bounds
      the worse case error when that data is monotonically increasing
      over the window.
      
      Upon getting a new min, we can forget everything earlier because
      it has no value - the new min is less than everything else in the
      window by definition and it's the most recent. So we restart fresh
      on every new min and overwrites the 2nd & 3rd choices. The same
      property holds for the 2nd & 3rd best.
      
      Therefore we have to maintain two invariants to maximize the
      information in the samples, one on values (1st.v <= 2nd.v <=
      3rd.v) and the other on times (now-win <=1st.t <= 2nd.t <= 3rd.t <=
      now). These invariants determine the structure of the code
      
      The RTT input to the windowed filter is the minimum RTT measured
      from ACK or SACK, or as the last resort from TCP timestamps.
      
      The accessor tcp_min_rtt() returns the minimum RTT seen in the
      window. ~0U indicates it is not available. The minimum is 1usec
      even if the true RTT is below that.
      Signed-off-by: NYuchung Cheng <ycheng@google.com>
      Signed-off-by: NNeal Cardwell <ncardwell@google.com>
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f6722583
  3. 17 10月, 2015 2 次提交
    • A
      netfilter: turn NF_HOOK into an inline function · 008027c3
      Arnd Bergmann 提交于
      A recent change to the dst_output handling caused a new warning
      when the call to NF_HOOK() is the only used of a local variable
      passed as 'dev', and CONFIG_NETFILTER is disabled:
      
      net/ipv6/ip6_output.c: In function 'ip6_output':
      net/ipv6/ip6_output.c:135:21: warning: unused variable 'dev' [-Wunused-variable]
      
      The reason for this is that the NF_HOOK macro in this case does
      not reference the variable at all, and the call to dev_net(dev)
      got removed from the ip6_output function. To avoid that warning now
      and in the future, this changes the macro into an equivalent
      inline function, which tells the compiler that the variable is
      passed correctly but still unused.
      
      The dn_forward function apparently had the same problem in
      the past and added a local workaround that no longer works
      with the inline function. In order to avoid a regression, we
      have to also remove the #ifdef from decnet in the same patch.
      
      Fixes: ede2059d ("dst: Pass net into dst->output")
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
      008027c3
    • F
      netfilter: remove hook owner refcounting · 2ffbceb2
      Florian Westphal 提交于
      since commit 8405a8ff ("netfilter: nf_qeueue: Drop queue entries on
      nf_unregister_hook") all pending queued entries are discarded.
      
      So we can simply remove all of the owner handling -- when module is
      removed it also needs to unregister all its hooks.
      Signed-off-by: NFlorian Westphal <fw@strlen.de>
      Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
      2ffbceb2
  4. 16 10月, 2015 1 次提交
  5. 15 10月, 2015 4 次提交
    • J
      net/mlx4_core: Replace VF zero mac with random mac in mlx4_core · 2b3ddf27
      Jack Morgenstein 提交于
      By design, when no default MAC addresses are set in the Hypervisor for VFs,
      the VFs are passed zero-macs. When such a MAC is received by the VF, it
      generates a random MAC address and registers that MAC address
      with the Hypervisor.
      
      This random mac generation is currently done in the mlx4_en module.
      There is a problem, though, if the mlx4_ib module is loaded by a VF before
      the mlx4_en module. In this case, for RoCE, mlx4_ib will see the un-replaced
      zero-mac and register that zero-mac as part of QP1 initialization.
      
      Having a zero-mac in the port's MAC table creates problems for a
      Baseboard Management Console. The BMC occasionally sends packets with a
      zero-mac destination MAC. If there is a zero-mac present in the port's
      MAC table, the FW will send such BMC packets to the host driver rather than
      to the wire, and BMC will stop working.
      
      To address this problem, we move the replacement of zero-mac addresses
      with random-mac addresses to procedure mlx4_slave_cap(), which is part of the
      driver startup for VFs, and is before activation of mlx4_ib and mlx4_en.
      As a result, zero-mac addresses will never be registered in the port MAC table
      by the driver.
      
      In addition, when mlx4_en does initialize the net device, it needs to set
      the NET_ADDR_RANDOM flag in the netdev structure if the address was
      randomly generated. This is done so that udev on the VM does not create
      a new device name after each VF probe (VM boot and such). To accomplish this,
      we add a per-port flag in mlx4_dev which gets set whenever mlx4_core replaces
      a zero-mac with a randomly-generated mac. This flag is examined when mlx4_en
      initializes the net-device.
      
      Fix was suggested by Matan Barak <matanb@mellanox.com>
      Signed-off-by: NJack Morgenstein <jackm@dev.mellanox.co.il>
      Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2b3ddf27
    • E
      net/mlx5_core: Wait for FW readiness on startup · e3297246
      Eli Cohen 提交于
      On device initialization, wait till firmware indicates that that it is done
      with initialization before proceeding to initialize the device.
      
      Also update initialization segment layout to match driver/firmware
      interface definitions.
      Signed-off-by: NEli Cohen <eli@mellanox.com>
      Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      e3297246
    • M
      net/mlx5_core: Add pci error handlers to mlx5_core driver · 89d44f0a
      Majd Dibbiny 提交于
      This patch implement the pci_error_handlers for mlx5_core which allow the
      driver to recover from PCI error.
      
      Once an error is detected in the PCI, the mlx5_pci_err_detected is called
      and it:
      1) Marks the device to be in 'Internal Error' state.
      2) Dispatches an event to the mlx5_ib to flush all the outstanding cqes
      with error.
      3) Returns all the on going commands with error.
      4) Unloads the driver.
      
      Afterwards, the FW is reset and mlx5_pci_slot_reset is called and it
      enables the device and restore it's pci state.
      
      If the later succeeds, mlx5_pci_resume is called, and it loads the SW
      stack.
      Signed-off-by: NMajd Dibbiny <majd@mellanox.com>
      Signed-off-by: NEli Cohen <eli@mellanox.com>
      Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      89d44f0a
    • E
      net/mlx5_core: Fix internal error detection conditions · fd76ee4d
      Eli Cohen 提交于
      The detection of a fatal condition has been updated to take into account
      the state reported by the device or by detecting an all ones read of the
      firmware version which indicates that the device is not accessible.
      Signed-off-by: NEli Cohen <eli@mellanox.com>
      Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fd76ee4d
  6. 13 10月, 2015 4 次提交
    • A
      can: at91: remove at91_can_data · 42160a04
      Alexandre Belloni 提交于
      struct at91_can_data was used to pass a callback to the driver, allowing it
      to switch the transceiver on and off. As all at91 boards are now using DT,
      this is not used anymore, remove that structure.
      Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
      Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>
      42160a04
    • E
      tcp: shrink tcp_timewait_sock by 8 bytes · d475f090
      Eric Dumazet 提交于
      Reducing tcp_timewait_sock from 280 bytes to 272 bytes
      allows SLAB to pack 15 objects per page instead of 14 (on x86)
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d475f090
    • A
      bpf: charge user for creation of BPF maps and programs · aaac3ba9
      Alexei Starovoitov 提交于
      since eBPF programs and maps use kernel memory consider it 'locked' memory
      from user accounting point of view and charge it against RLIMIT_MEMLOCK limit.
      This limit is typically set to 64Kbytes by distros, so almost all
      bpf+tracing programs would need to increase it, since they use maps,
      but kernel charges maximum map size upfront.
      For example the hash map of 1024 elements will be charged as 64Kbyte.
      It's inconvenient for current users and changes current behavior for root,
      but probably worth doing to be consistent root vs non-root.
      
      Similar accounting logic is done by mmap of perf_event.
      Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      aaac3ba9
    • A
      bpf: enable non-root eBPF programs · 1be7f75d
      Alexei Starovoitov 提交于
      In order to let unprivileged users load and execute eBPF programs
      teach verifier to prevent pointer leaks.
      Verifier will prevent
      - any arithmetic on pointers
        (except R10+Imm which is used to compute stack addresses)
      - comparison of pointers
        (except if (map_value_ptr == 0) ... )
      - passing pointers to helper functions
      - indirectly passing pointers in stack to helper functions
      - returning pointer from bpf program
      - storing pointers into ctx or maps
      
      Spill/fill of pointers into stack is allowed, but mangling
      of pointers stored in the stack or reading them byte by byte is not.
      
      Within bpf programs the pointers do exist, since programs need to
      be able to access maps, pass skb pointer to LD_ABS insns, etc
      but programs cannot pass such pointer values to the outside
      or obfuscate them.
      
      Only allow BPF_PROG_TYPE_SOCKET_FILTER unprivileged programs,
      so that socket filters (tcpdump), af_packet (quic acceleration)
      and future kcm can use it.
      tracing and tc cls/act program types still require root permissions,
      since tracing actually needs to be able to see all kernel pointers
      and tc is for root only.
      
      For example, the following unprivileged socket filter program is allowed:
      int bpf_prog1(struct __sk_buff *skb)
      {
        u32 index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
        u64 *value = bpf_map_lookup_elem(&my_map, &index);
      
        if (value)
      	*value += skb->len;
        return 0;
      }
      
      but the following program is not:
      int bpf_prog1(struct __sk_buff *skb)
      {
        u32 index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
        u64 *value = bpf_map_lookup_elem(&my_map, &index);
      
        if (value)
      	*value += (u64) skb;
        return 0;
      }
      since it would leak the kernel address into the map.
      
      Unprivileged socket filter bpf programs have access to the
      following helper functions:
      - map lookup/update/delete (but they cannot store kernel pointers into them)
      - get_random (it's already exposed to unprivileged user space)
      - get_smp_processor_id
      - tail_call into another socket filter program
      - ktime_get_ns
      
      The feature is controlled by sysctl kernel.unprivileged_bpf_disabled.
      This toggle defaults to off (0), but can be set true (1).  Once true,
      bpf programs and maps cannot be accessed from unprivileged process,
      and the toggle cannot be set back to false.
      Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
      Reviewed-by: NKees Cook <keescook@chromium.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1be7f75d
  7. 11 10月, 2015 1 次提交
    • A
      bpf: fix cb access in socket filter programs · ff936a04
      Alexei Starovoitov 提交于
      eBPF socket filter programs may see junk in 'u32 cb[5]' area,
      since it could have been used by protocol layers earlier.
      
      For socket filter programs used in af_packet we need to clean
      20 bytes of skb->cb area if it could be used by the program.
      For programs attached to TCP/UDP sockets we need to save/restore
      these 20 bytes, since it's used by protocol layers.
      
      Remove SK_RUN_FILTER macro, since it's no longer used.
      
      Long term we may move this bpf cb area to per-cpu scratch, but that
      requires addition of new 'per-cpu load/store' instructions,
      so not suitable as a short term fix.
      
      Fixes: d691f9e8 ("bpf: allow programs to write to certain skb fields")
      Reported-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ff936a04
  8. 09 10月, 2015 11 次提交
  9. 08 10月, 2015 6 次提交
  10. 07 10月, 2015 1 次提交
  11. 06 10月, 2015 2 次提交
  12. 05 10月, 2015 3 次提交