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  1. 11 5月, 2018 7 次提交
  3. 10 5月, 2018 2 次提交
  5. 08 5月, 2018 6 次提交
  7. 07 5月, 2018 7 次提交
  9. 05 5月, 2018 1 次提交
  11. 04 5月, 2018 17 次提交
    • S
      smc: add support for splice() · 9014db20
      由 Stefan Raspl 提交于 
      Provide an implementation for splice() when we are using SMC. See
smc_splice_read() for further details.
Signed-off-by: NStefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com><
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9014db20
    • S
      smc: allocate RMBs as compound pages · 2ef4f27a
      由 Stefan Raspl 提交于 
      Preparatory work for splice() support.
Signed-off-by: NStefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com><
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2ef4f27a
    • S
      smc: make smc_rx_wait_data() generic · b51fa1b1
      由 Stefan Raspl 提交于 
      Turn smc_rx_wait_data into a generic function that can be used at various
instances to wait on traffic to complete with varying criteria.
Signed-off-by: NStefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com><
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b51fa1b1
    • S
      smc: simplify abort logic · c8b8ec8e
      由 Stefan Raspl 提交于 
      Some of the conditions to exit recv() are common in two pathes - cleaning up
code by moving the check up so we have it only once.
Signed-off-by: NStefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com><
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c8b8ec8e
    • M
      xfrm: use a dedicated slab cache for struct xfrm_state · 565f0fa9
      由 Mathias Krause 提交于 
      struct xfrm_state is rather large (768 bytes here) and therefore wastes
quite a lot of memory as it falls into the kmalloc-1024 slab cache,
leaving 256 bytes of unused memory per XFRM state object -- a net waste
of 25%.

Using a dedicated slab cache for struct xfrm_state reduces the level of
internal fragmentation to a minimum.

On my configuration SLUB chooses to create a slab cache covering 4
pages holding 21 objects, resulting in an average memory waste of ~13
bytes per object -- a net waste of only 1.6%.

In my tests this led to memory savings of roughly 2.3MB for 10k XFRM
states.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
      565f0fa9
    • D
      bpf: add skb_load_bytes_relative helper · 4e1ec56c
      由 Daniel Borkmann 提交于 
      This adds a small BPF helper similar to bpf_skb_load_bytes() that
is able to load relative to mac/net header offset from the skb's
linear data. Compared to bpf_skb_load_bytes(), it takes a fifth
argument namely start_header, which is either BPF_HDR_START_MAC
or BPF_HDR_START_NET. This allows for a more flexible alternative
compared to LD_ABS/LD_IND with negative offset. It's enabled for
tc BPF programs as well as sock filter program types where it's
mainly useful in reuseport programs to ease access to lower header
data.

Reference: https://lists.iovisor.org/pipermail/iovisor-dev/2017-March/000698.htmlSigned-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      4e1ec56c
    • D
      bpf: implement ld_abs/ld_ind in native bpf · e0cea7ce
      由 Daniel Borkmann 提交于 
      The main part of this work is to finally allow removal of LD_ABS
and LD_IND from the BPF core by reimplementing them through native
eBPF instead. Both LD_ABS/LD_IND were carried over from cBPF and
keeping them around in native eBPF caused way more trouble than
actually worth it. To just list some of the security issues in
the past:

  * fdfaf64e ("x86: bpf_jit: support negative offsets")
  * 35607b02 ("sparc: bpf_jit: fix loads from negative offsets")
  * e0ee9c12 ("x86: bpf_jit: fix two bugs in eBPF JIT compiler")
  * 07aee943 ("bpf, sparc: fix usage of wrong reg for load_skb_regs after call")
  * 6d59b7db ("bpf, s390x: do not reload skb pointers in non-skb context")
  * 87338c8e ("bpf, ppc64: do not reload skb pointers in non-skb context")

For programs in native eBPF, LD_ABS/LD_IND are pretty much legacy
these days due to their limitations and more efficient/flexible
alternatives that have been developed over time such as direct
packet access. LD_ABS/LD_IND only cover 1/2/4 byte loads into a
register, the load happens in host endianness and its exception
handling can yield unexpected behavior. The latter is explained
in depth in f6b1b3bf ("bpf: fix subprog verifier bypass by
div/mod by 0 exception") with similar cases of exceptions we had.
In native eBPF more recent program types will disable LD_ABS/LD_IND
altogether through may_access_skb() in verifier, and given the
limitations in terms of exception handling, it's also disabled
in programs that use BPF to BPF calls.

In terms of cBPF, the LD_ABS/LD_IND is used in networking programs
to access packet data. It is not used in seccomp-BPF but programs
that use it for socket filtering or reuseport for demuxing with
cBPF. This is mostly relevant for applications that have not yet
migrated to native eBPF.

The main complexity and source of bugs in LD_ABS/LD_IND is coming
from their implementation in the various JITs. Most of them keep
the model around from cBPF times by implementing a fastpath written
in asm. They use typically two from the BPF program hidden CPU
registers for caching the skb's headlen (skb->len - skb->data_len)
and skb->data. Throughout the JIT phase this requires to keep track
whether LD_ABS/LD_IND are used and if so, the two registers need
to be recached each time a BPF helper would change the underlying
packet data in native eBPF case. At least in eBPF case, available
CPU registers are rare and the additional exit path out of the
asm written JIT helper makes it also inflexible since not all
parts of the JITer are in control from plain C. A LD_ABS/LD_IND
implementation in eBPF therefore allows to significantly reduce
the complexity in JITs with comparable performance results for
them, e.g.:

test_bpf             tcpdump port 22             tcpdump complex
x64      - before    15 21 10                    14 19  18
         - after      7 10 10                     7 10  15
arm64    - before    40 91 92                    40 91 151
         - after     51 64 73                    51 62 113

For cBPF we now track any usage of LD_ABS/LD_IND in bpf_convert_filter()
and cache the skb's headlen and data in the cBPF prologue. The
BPF_REG_TMP gets remapped from R8 to R2 since it's mainly just
used as a local temporary variable. This allows to shrink the
image on x86_64 also for seccomp programs slightly since mapping
to %rsi is not an ereg. In callee-saved R8 and R9 we now track
skb data and headlen, respectively. For normal prologue emission
in the JITs this does not add any extra instructions since R8, R9
are pushed to stack in any case from eBPF side. cBPF uses the
convert_bpf_ld_abs() emitter which probes the fast path inline
already and falls back to bpf_skb_load_helper_{8,16,32}() helper
relying on the cached skb data and headlen as well. R8 and R9
never need to be reloaded due to bpf_helper_changes_pkt_data()
since all skb access in cBPF is read-only. Then, for the case
of native eBPF, we use the bpf_gen_ld_abs() emitter, which calls
the bpf_skb_load_helper_{8,16,32}_no_cache() helper unconditionally,
does neither cache skb data and headlen nor has an inlined fast
path. The reason for the latter is that native eBPF does not have
any extra registers available anyway, but even if there were, it
avoids any reload of skb data and headlen in the first place.
Additionally, for the negative offsets, we provide an alternative
bpf_skb_load_bytes_relative() helper in eBPF which operates
similarly as bpf_skb_load_bytes() and allows for more flexibility.
Tested myself on x64, arm64, s390x, from Sandipan on ppc64.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      e0cea7ce
    • D
      bpf: migrate ebpf ld_abs/ld_ind tests to test_verifier · 93731ef0
      由 Daniel Borkmann 提交于 
      Remove all eBPF tests involving LD_ABS/LD_IND from test_bpf.ko. Reason
is that the eBPF tests from test_bpf module do not go via BPF verifier
and therefore any instruction rewrites from verifier cannot take place.

Therefore, move them into test_verifier which runs out of user space,
so that verfier can rewrite LD_ABS/LD_IND internally in upcoming patches.
It will have the same effect since runtime tests are also performed from
there. This also allows to finally unexport bpf_skb_vlan_{push,pop}_proto
and keep it internal to core kernel.

Additionally, also add further cBPF LD_ABS/LD_IND test coverage into
test_bpf.ko suite.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      93731ef0
    • D
      bpf: prefix cbpf internal helpers with bpf_ · b390134c
      由 Daniel Borkmann 提交于 
      No change in functionality, just remove the '__' prefix and replace it
with a 'bpf_' prefix instead. We later on add a couple of more helpers
for cBPF and keeping the scheme with '__' is suboptimal there.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      b390134c
    • M
      xsk: statistics support · af75d9e0
      由 Magnus Karlsson 提交于 
      In this commit, a new getsockopt is added: XDP_STATISTICS. This is
used to obtain stats from the sockets.

v2: getsockopt now returns size of stats structure.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      af75d9e0
    • M
      xsk: support for Tx · 35fcde7f
      由 Magnus Karlsson 提交于 
      Here, Tx support is added. The user fills the Tx queue with frames to
be sent by the kernel, and let's the kernel know using the sendmsg
syscall.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      35fcde7f
    • M
      dev: packet: make packet_direct_xmit a common function · 865b03f2
      由 Magnus Karlsson 提交于 
      The new dev_direct_xmit will be used by AF_XDP in later commits.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      865b03f2
    • M
      xsk: add Tx queue setup and mmap support · f6145903
      由 Magnus Karlsson 提交于 
      Another setsockopt (XDP_TX_QUEUE) is added to let the process allocate
a queue, where the user process can pass frames to be transmitted by
the kernel.

The mmapping of the queue is done using the XDP_PGOFF_TX_QUEUE offset.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      f6145903
    • M
      xsk: add umem completion queue support and mmap · fe230832
      由 Magnus Karlsson 提交于 
      Here, we add another setsockopt for registered user memory (umem)
called XDP_UMEM_COMPLETION_QUEUE. Using this socket option, the
process can ask the kernel to allocate a queue (ring buffer) and also
mmap it (XDP_UMEM_PGOFF_COMPLETION_QUEUE) into the process.

The queue is used to explicitly pass ownership of umem frames from the
kernel to user process. This will be used by the TX path to tell user
space that a certain frame has been transmitted and user space can use
it for something else, if it wishes.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      fe230832
    • B
      xsk: wire up XDP_SKB side of AF_XDP · 02671e23
      由 Björn Töpel 提交于 
      This commit wires up the xskmap to XDP_SKB layer.
Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      02671e23
    • B
      xsk: wire up XDP_DRV side of AF_XDP · 1b1a251c
      由 Björn Töpel 提交于 
      This commit wires up the xskmap to XDP_DRV layer.
Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      1b1a251c
    • B
      bpf: introduce new bpf AF_XDP map type BPF_MAP_TYPE_XSKMAP · fbfc504a
      由 Björn Töpel 提交于 
      The xskmap is yet another BPF map, very much inspired by
dev/cpu/sockmap, and is a holder of AF_XDP sockets. A user application
adds AF_XDP sockets into the map, and by using the bpf_redirect_map
helper, an XDP program can redirect XDP frames to an AF_XDP socket.

Note that a socket that is bound to certain ifindex/queue index will
*only* accept XDP frames from that netdev/queue index. If an XDP
program tries to redirect from a netdev/queue index other than what
the socket is bound to, the frame will not be received on the socket.

A socket can reside in multiple maps.

v3: Fixed race and simplified code.
v2: Removed one indirection in map lookup.
Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      fbfc504a