David Ahern says:

====================
Packets that exceed the egress MTU can not be forwarded in the fast path.
Add IPv4 and IPv6 MTU helpers that take a FIB lookup result (versus the
typical dst path) and add the calls to bpf_ipv{4,6}_fib_lookup.

v2
- add ip6_mtu_from_fib6 to ipv6_stub
- only call the new MTU helpers for fib lookups in XDP path; skb
  path uses is_skb_forwardable to determine if the packet can be
  sent via the egress device from the FIB lookup
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Add check that egress MTU can handle packet to be forwarded. If
the MTU is less than the packet length, return 0 meaning the
packet is expected to continue up the stack for help - eg.,
fragmenting the packet or sending an ICMP.

The XDP path needs to leverage the FIB entry for an MTU on the
route spec or an exception entry for a given destination. The
skb path lets is_skb_forwardable decide if the packet can be
sent.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Determine path MTU from a FIB lookup result. Logic is based on
ip6_dst_mtu_forward plus lookup of nexthop exception.

Add ip6_dst_mtu_forward to ipv6_stubs to handle access by core
bpf code.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Determine path MTU from a FIB lookup result. Logic is a distillation of
ip_dst_mtu_maybe_forward.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Björn Töpel says:

====================
This the second follow-up set. The first four patches are uapi
changes:

* Removing rebind support
* Getting rid of structure hole
* Removing explicit cache line alignment
* Stricter bind checks

The last patches do some cleanups, where the umem and refcount_t
changes were suggested by Daniel.

* Add a missing write-barrier and use READ_ONCE for data-dependencies
* Clean up umem and do proper locking
* Convert atomic_t to refcount_t
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Introduce refcount_t, in favor of atomic_t.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

As suggested by Daniel Borkmann, the umem setup code was a too
defensive and complex. Here, we reduce the number of checks. Also, the
memory pinning is now folded into the umem creation, and we do correct
locking.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Here, we add a missing write-barrier, and use READ_ONCE for the
data-dependency barrier.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Adapt xdpsock to use the new getsockopt introduced in the previous
commit.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

In this commit we remove the explicit ring structure from the the
uapi. It is tricky for an uapi to depend on a certain L1 cache line
size, since it can differ for variants of the same architecture. Now,
we let the user application determine the offsets of the producer,
consumer and descriptors by asking the socket via getsockopt.

A typical flow would be (Rx ring):

  struct xdp_mmap_offsets off;
  struct xdp_desc *ring;
  u32 *prod, *cons;
  void *map;
  ...

  getsockopt(fd, SOL_XDP, XDP_MMAP_OFFSETS, &off, &optlen);

  map = mmap(NULL, off.rx.desc +
		   NUM_DESCS * sizeof(struct xdp_desc),
		   PROT_READ | PROT_WRITE,
		   MAP_SHARED | MAP_POPULATE, sfd,
		   XDP_PGOFF_RX_RING);
  prod = map + off.rx.producer;
  cons = map + off.rx.consumer;
  ring = map + off.rx.desc;
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Validate the queue id against both Rx and Tx on the netdev. Also, make
sure that the queue exists at xmit time.
Reported-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Move the sxdp_flags up, avoiding a hole in the uapi structure.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Supporting rebind, i.e. after a successful bind the process can call
bind again without closing the socket, makes the AF_XDP setup state
machine more complex. Constrain the state space, by not supporting
rebind.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

John Fastabend says:

====================
In this series we add the ability for sk msg programs to read basic
sock information about the sock they are attached to. The second
patch adds the tests to the selftest test_verifier.

One observation that I had from writing this seriess is lots of the
./net/core/filter.c code is almost duplicated across program types.
I thought about building a template/macro that we could use as a
single block of code to read sock data out for multiple programs,
but I wasn't convinced it was worth it yet. The result was using a
macro saved a couple lines of code per block but made the code
a bit harder to read IMO. We can probably revisit the idea later
if we get more duplication.

v2: add errstr field to negative test_verifier test cases to ensure
    we get the expected err string back from the verifier.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Add tests for BPF_PROG_TYPE_SK_MSG to test_verifier for read access
to new sk fields.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Currently sk_msg programs only have access to the raw data. However,
it is often useful when building policies to have the policies specific
to the socket endpoint. This allows using the socket tuple as input
into filters, etc.

This patch adds ctx access to the sock fields.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Jiong Wang says:

====================
NFP eBPF JIT is missing logic indirect shifts (both left and right) and
arithmetic right shift (both indirect shift and shift by constant).

This patch adds support for them.

For indirect shifts, shift amount is not specified as constant, NFP needs
to get the shift amount through the low 5 bits of source A operand in
PREV_ALU, therefore extra instructions are needed compared with shifts by
constants.

Because NFP is 32-bit, so we are using register pair for 64-bit shifts and
therefore would need different instruction sequences depending on whether
shift amount is less than 32 or not.

NFP branch-on-bit-test instruction emitter is added by this patch set and
is used for efficient runtime check on shift amount. We'd think the shift
amount is less than 32 if bit 5 is clear and greater or equal then 32
otherwise. Shift amount is greater than or equal to 64 will result in
undefined behavior.

This patch also use range info to avoid generating unnecessary runtime code
if we are certain shift amount is less than 32 or not.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Code logic is similar with arithmetic right shift by constant, and NFP
get indirect shift amount through source A operand of PREV_ALU.

It is possible to fall back to logic right shift if the MSB is known to be
zero from range info, however there is no benefit to do this given logic
indirect right shift use the same number and cycle of instruction sequence.

Suppose the MSB of regX is the bit we want to replicate to fill in all the
vacant positions, and regY contains the shift amount, then we could use
single instruction to set up both.

  [alu, --, regY, OR, regX]

  --
  NOTE: the PREV_ALU result doesn't need to write to any destination
        register.
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Code logic is similar with logic right shift except we also need to set
PREV_ALU result properly, the MSB of which is the bit that will be
replicated to fill in all the vacant positions.
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

For indirect shifts, shift amount is not specified as constant, NFP needs
to get the shift amount through the low 5 bits of source A operand in
PREV_ALU, therefore extra instructions are needed compared with shifts by
constants.

Because NFP is 32-bit, so we are using register pair for 64-bit shifts and
therefore would need different instruction sequences depending on whether
shift amount is less than 32 or not.

NFP branch-on-bit-test instruction emitter is added by this patch and is
used for efficient runtime check on shift amount. We'd think the shift
amount is less than 32 if bit 5 is clear and greater or equal than 32
otherwise. Shift amount is greater than or equal to 64 will result in
undefined behavior.

This patch also use range info to avoid generating unnecessary runtime code
if we are certain shift amount is less than 32 or not.
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Björn Töpel says:

====================
This series contain "cosmetics only" follow-up patches for AF_XDP.

Thanks to Daniel for suggesting them!
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Properly align xsk_proto_ops initialization.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Removed some cases of unnecessary parentheses.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Minor cleanup, remove newline at end of Makefile.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Clean up SPDX-License-Identifier and removing licensing leftovers.
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

`e' is being freed twice.

Fix this by removing one of the kfree() calls.

Addresses-Coverity-ID: 1468983 ("Double free")
Fixes: 81110384 ("bpf: sockmap, add hash map support")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

There is a potential execution path in which variable err is
returned without being properly initialized previously.

Fix this by initializing variable err to 0.

Addresses-Coverity-ID: 1468964 ("Uninitialized scalar variable")
Fixes: e5cd3abc ("bpf: sockmap, refactor sockmap routines to work with hashmap")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Documentation for eBPF helpers can be parsed from bpf.h and eventually
turned into a man page. Commit 6f96674d ("bpf: relax constraints on
formatting for eBPF helper documentation") changed the script used to
parse it, in order to allow for different indent style and to ease the
work for writing documentation for future helpers.

The script currently considers that the first tab can be replaced by 6
to 8 spaces. But the documentation for bpf_fib_lookup() uses a mix of
tabs (for the "Description" part) and of spaces ("Return" part), and
only has 5 space long indent for the latter.

We probably do not want to change the values accepted by the script each
time a new helper gets a new indent style. However, it is worth noting
that with those 5 spaces, the "Description" and "Return" part *look*
aligned in the generated patch and in `git show`, so it is likely other
helper authors will use the same length. Therefore, allow for helper
documentation to use 5 spaces only for the first indent level.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Daniel Borkmann says:

====================
pull-request: bpf-next 2018-05-17

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Provide a new BPF helper for doing a FIB and neighbor lookup
   in the kernel tables from an XDP or tc BPF program. The helper
   provides a fast-path for forwarding packets. The API supports
   IPv4, IPv6 and MPLS protocols, but currently IPv4 and IPv6 are
   implemented in this initial work, from David (Ahern).

2) Just a tiny diff but huge feature enabled for nfp driver by
   extending the BPF offload beyond a pure host processing offload.
   Offloaded XDP programs are allowed to set the RX queue index and
   thus opening the door for defining a fully programmable RSS/n-tuple
   filter replacement. Once BPF decided on a queue already, the device
   data-path will skip the conventional RSS processing completely,
   from Jakub.

3) The original sockmap implementation was array based similar to
   devmap. However unlike devmap where an ifindex has a 1:1 mapping
   into the map there are use cases with sockets that need to be
   referenced using longer keys. Hence, sockhash map is added reusing
   as much of the sockmap code as possible, from John.

4) Introduce BTF ID. The ID is allocatd through an IDR similar as
   with BPF maps and progs. It also makes BTF accessible to user
   space via BPF_BTF_GET_FD_BY_ID and adds exposure of the BTF data
   through BPF_OBJ_GET_INFO_BY_FD, from Martin.

5) Enable BPF stackmap with build_id also in NMI context. Due to the
   up_read() of current->mm->mmap_sem build_id cannot be parsed.
   This work defers the up_read() via a per-cpu irq_work so that
   at least limited support can be enabled, from Song.

6) Various BPF JIT follow-up cleanups and fixups after the LD_ABS/LD_IND
   JIT conversion as well as implementation of an optimized 32/64 bit
   immediate load in the arm64 JIT that allows to reduce the number of
   emitted instructions; in case of tested real-world programs they
   were shrinking by three percent, from Daniel.

7) Add ifindex parameter to the libbpf loader in order to enable
   BPF offload support. Right now only iproute2 can load offloaded
   BPF and this will also enable libbpf for direct integration into
   other applications, from David (Beckett).

8) Convert the plain text documentation under Documentation/bpf/ into
   RST format since this is the appropriate standard the kernel is
   moving to for all documentation. Also add an overview README.rst,
   from Jesper.

9) Add __printf verification attribute to the bpf_verifier_vlog()
   helper. Though it uses va_list we can still allow gcc to check
   the format string, from Mathieu.

10) Fix a bash reference in the BPF selftest's Makefile. The '|& ...'
    is a bash 4.0+ feature which is not guaranteed to be available
    when calling out to shell, therefore use a more portable variant,
    from Joe.

11) Fix a 64 bit division in xdp_umem_reg() by using div_u64()
    instead of relying on the gcc built-in, from Björn.

12) Fix a sock hashmap kmalloc warning reported by syzbot when an
    overly large key size is used in hashmap then causing overflows
    in htab->elem_size. Reject bogus attr->key_size early in the
    sock_hash_alloc(), from Yonghong.

13) Ensure in BPF selftests when urandom_read is being linked that
    --build-id is always enabled so that test_stacktrace_build_id[_nmi]
    won't be failing, from Alexei.

14) Add bitsperlong.h as well as errno.h uapi headers into the tools
    header infrastructure which point to one of the arch specific
    uapi headers. This was needed in order to fix a build error on
    some systems for the BPF selftests, from Sirio.

15) Allow for short options to be used in the xdp_monitor BPF sample
    code. And also a bpf.h tools uapi header sync in order to fix a
    selftest build failure. Both from Prashant.

16) More formally clarify the meaning of ID in the direct packet access
    section of the BPF documentation, from Wang.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

When an error happens in the update sockmap element logic also pass
the err up to the user.

Fixes: e5cd3abc ("bpf: sockmap, refactor sockmap routines to work with hashmap")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

syzbot reported a kernel warning below:
  WARNING: CPU: 0 PID: 4499 at mm/slab_common.c:996 kmalloc_slab+0x56/0x70 mm/slab_common.c:996
  Kernel panic - not syncing: panic_on_warn set ...

  CPU: 0 PID: 4499 Comm: syz-executor050 Not tainted 4.17.0-rc3+ #9
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  Call Trace:
   __dump_stack lib/dump_stack.c:77 [inline]
   dump_stack+0x1b9/0x294 lib/dump_stack.c:113
   panic+0x22f/0x4de kernel/panic.c:184
   __warn.cold.8+0x163/0x1b3 kernel/panic.c:536
   report_bug+0x252/0x2d0 lib/bug.c:186
   fixup_bug arch/x86/kernel/traps.c:178 [inline]
   do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296
   do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
   invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
  RIP: 0010:kmalloc_slab+0x56/0x70 mm/slab_common.c:996
  RSP: 0018:ffff8801d907fc58 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff8801aeecb280 RCX: ffffffff8185ebd7
  RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000ffffffe1
  RBP: ffff8801d907fc58 R08: ffff8801adb5e1c0 R09: ffffed0035a84700
  R10: ffffed0035a84700 R11: ffff8801ad423803 R12: ffff8801aeecb280
  R13: 00000000fffffff4 R14: ffff8801ad891a00 R15: 00000000014200c0
   __do_kmalloc mm/slab.c:3713 [inline]
   __kmalloc+0x25/0x760 mm/slab.c:3727
   kmalloc include/linux/slab.h:517 [inline]
   map_get_next_key+0x24a/0x640 kernel/bpf/syscall.c:858
   __do_sys_bpf kernel/bpf/syscall.c:2131 [inline]
   __se_sys_bpf kernel/bpf/syscall.c:2096 [inline]
   __x64_sys_bpf+0x354/0x4f0 kernel/bpf/syscall.c:2096
   do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

The test case is against sock hashmap with a key size 0xffffffe1.
Such a large key size will cause the below code in function
sock_hash_alloc() overflowing and produces a smaller elem_size,
hence map creation will be successful.
    htab->elem_size = sizeof(struct htab_elem) +
                      round_up(htab->map.key_size, 8);

Later, when map_get_next_key is called and kernel tries
to allocate the key unsuccessfully, it will issue
the above warning.

Similar to hashtab, ensure the key size is at most
MAX_BPF_STACK for a successful map creation.

Fixes: 81110384 ("bpf: sockmap, add hash map support")
Reported-by: syzbot+e4566d29080e7f3460ff@syzkaller.appspotmail.com
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

BPF programs currently can only be offloaded using iproute2. This
patch will allow programs to be offloaded using libbpf calls.
Signed-off-by: David Beckett <david.beckett@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

__printf is useful to verify format and arguments. ‘bpf_verifier_vlog’
function is used twice in verifier.c in both cases the caller function
already uses the __printf gcc attribute.

Remove the following warning, triggered with W=1:

  kernel/bpf/verifier.c:176:2: warning: function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Only consider forwarding packets if ttl in received packet is > 1 and
decrement ttl before handing off to bpf_redirect_map.
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

John Fastabend says:

====================
In the original sockmap implementation we got away with using an
array similar to devmap. However, unlike devmap where an ifindex
has a nice 1:1 function into the map we have found some use cases
with sockets that need to be referenced using longer keys.

This series adds support for a sockhash map reusing as much of
the sockmap code as possible. I made the decision to add sockhash
specific helpers vs trying to generalize the existing helpers
because (a) they have sockmap in the name and (b) the keys are
different types. I prefer to be explicit here rather than play
type games or do something else tricky.

To test this we duplicate all the sockmap testing except swap out
the sockmap with a sockhash.

v2: fix file stats and add v2 tag
v3: move tool updates into test patch, move bpftool updates into
    its own patch, and fixup the test patch stats to catch the
    renamed file and provide only diffs ± on that.
v4: Add documentation to UAPI bpf.h
v5: Add documentation to tools UAPI bpf.h
v6: 'git add' test_sockhash_kern.c which was previously missing
    but was not causing issues because of typo in test script,
    noticed by Daniel. After this the git format-patch -M option
    no longer tracks the rename of the test_sockmap_kern files for
    some reason. I guess the diff has exceeded some threshold.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

This adds the SOCKHASH map type to bpftools so that we get correct
pretty printing.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

This runs existing SOCKMAP tests with SOCKHASH map type. To do this
we push programs into include file and build two BPF programs. One
for SOCKHASH and one for SOCKMAP.

We then run the entire test suite with each type.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

For T6, clip table is separated from main TCAM. So, update LE-TCAM
collection logic to collect clip table TCAM as well. IPv6 takes
4 entries in clip table TCAM compared to 2 entries in main TCAM.

Also, in case of errors, keep LE-TCAM collected so far and set the
status to partial dump.
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Michal Kalderon says:

====================
qed: LL2 fixes

This series fixes some issues in ll2 related to synchronization
and resource freeing
====================
Signed-off-by: Ariel Elior <Ariel.Elior@cavium.com>
Signed-off-by: Michal Kalderon <Michal.Kalderon@cavium.com>

Stress on qedi/qedr load unload lead to list_del corruption.
This is due to ll2 connection terminate freeing resources without
verifying that no more ll2 processing will occur.

This patch unregisters the ll2 status block before terminating
the connection to assure this race does not occur.

Fixes: 1d6cff4f ("qed: Add iSCSI out of order packet handling")
Signed-off-by: Ariel Elior <Ariel.Elior@cavium.com>
Signed-off-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>