Add new TCP-BPF callback that is called on listen(2) right after socket
transition to TCP_LISTEN state.

It fills the gap for listening sockets in TCP-BPF. For example BPF
program can set BPF_SOCK_OPS_STATE_CB_FLAG when socket becomes listening
and track later transition from TCP_LISTEN to TCP_CLOSE with
BPF_SOCK_OPS_STATE_CB callback.

Before there was no way to do it with TCP-BPF and other options were
much harder to work with. E.g. socket state tracking can be done with
tracepoints (either raw or regular) but they can't be attached to cgroup
and their lifetime has to be managed separately.
Signed-off-by: NAndrey Ignatov <rdna@fb.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This patch augments the output of bpftool's map dump and map lookup
commands to print data along side btf info, if the correspondin btf
info is available. The outputs for each of  map dump and map lookup
commands are augmented in two ways:

1. when neither of -j and -p are supplied, btf-ful map data is printed
whose aim is human readability. This means no commitments for json- or
backward- compatibility.

2. when either -j or -p are supplied, a new json object named
"formatted" is added for each key-value pair. This object contains the
same data as the key-value pair, but with btf info. "formatted" object
promises json- and backward- compatibility. Below is a sample output.

$ bpftool map dump -p id 8
[{
        "key": ["0x0f","0x00","0x00","0x00"
        ],
        "value": ["0x03", "0x00", "0x00", "0x00", ...
        ],
        "formatted": {
                "key": 15,
                "value": {
                        "int_field":  3,
                        ...
                }
        }
}
]

This patch calls btf_dumper introduced in previous patch to accomplish
the above. Indeed, btf-ful info is only displayed if btf data for the
given map is available. Otherwise existing output is displayed as-is.
Signed-off-by: NOkash Khawaja <osk@fb.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This consumes functionality exported in the previous patch. It does the
main job of printing with BTF data. This is used in the following patch
to provide a more readable output of a map's dump. It relies on
json_writer to do json printing. Below is sample output where map keys
are ints and values are of type struct A:

typedef int int_type;
enum E {
        E0,
        E1,
};

struct B {
        int x;
        int y;
};

struct A {
        int m;
        unsigned long long n;
        char o;
        int p[8];
        int q[4][8];
        enum E r;
        void *s;
        struct B t;
        const int u;
        int_type v;
        unsigned int w1: 3;
        unsigned int w2: 3;
};

$ sudo bpftool map dump id 14
[{
        "key": 0,
        "value": {
            "m": 1,
            "n": 2,
            "o": "c",
            "p": [15,16,17,18,15,16,17,18
            ],
            "q": [[25,26,27,28,25,26,27,28
                ],[35,36,37,38,35,36,37,38
                ],[45,46,47,48,45,46,47,48
                ],[55,56,57,58,55,56,57,58
                ]
            ],
            "r": 1,
            "s": 0x7ffd80531cf8,
            "t": {
                "x": 5,
                "y": 10
            },
            "u": 100,
            "v": 20,
            "w1": 0x7,
            "w2": 0x3
        }
    }
]

This patch uses json's {} and [] to imply struct/union and array. More
explicit information can be added later. For example, a command line
option can be introduced to print whether a key or value is struct
or union, name of a struct etc. This will however come at the expense
of duplicating info when, for example, printing an array of structs.
enums are printed as ints without their names.
Signed-off-by: NOkash Khawaja <osk@fb.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This patch introduces btf__resolve_type() function and exports two
existing functions from libbpf. btf__resolve_type follows modifier
types like const and typedef until it hits a type which actually takes
up memory, and then returns it. This function follows similar pattern
to btf__resolve_size but instead of computing size, it just returns
the type.

These  functions will be used in the followig patch which parses
information inside array of `struct btf_type *`. btf_name_by_offset is
used for printing variable names.
Signed-off-by: NOkash Khawaja <osk@fb.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NSong Liu <songliubraving@fb.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

perf propagates its feature check results to libbpf.  This means
features for which perf probes must be a superset of libbpf's
required features.  perf depends on FEATURE_TESTS_BASIC for its list
of features.

commit 531b014e ("tools: bpf: make use of reallocarray") added
reallocarray use to libbpf, make perf also perform the reallocarray
feature check.

Fixes: 531b014e ("tools: bpf: make use of reallocarray")
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

People noticed that the code match on IEEE 802.1ad (ETH_P_8021AD) ethertype,
and this implies Q-in-Q or double tagged VLANs.  Thus, we better parse
the next VLAN header too.  It is even marked as a TODO.

This is relevant for real world use-cases, as XDP cpumap redirect can be
used when the NIC RSS hashing is broken.  E.g. the ixgbe driver HW cannot
handle double tagged VLAN packets, and places everything into a single
RX queue.  Using cpumap redirect, users can redistribute traffic across
CPUs to solve this, which is faster than the network stacks RPS solution.

It is left as an exerise how to distribute the packets across CPUs.  It
would be convenient to use the RX hash, but that is not _yet_ exposed
to XDP programs. For now, users can code their own hash, as I've demonstrated
in the Suricata code (where Q-in-Q is handled correctly).
Reported-by: NFlorian Maury <florian.maury-cv@x-cli.eu>
Reported-by: NMarek Majkowski <marek@cloudflare.com>
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Jakub Kicinski says:

====================
This set is adding support for loading driver and offload XDP
at the same time.  This enables advanced use cases where some
of the work is offloaded to the NIC and some is done by the host.
Separate netlink attributes are added for each mode of operation.
Driver callbacks for offload are cleaned up a little, including
removal of .prog_attached flag.
====================
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Split handling of offloaded and driver programs completely.  Since
offloaded programs always come with XDP_FLAGS_HW_MODE set in reality
there could be no sharing, anyway, programs would only be installed
in driver or in hardware.  Splitting the handling allows us to install
programs in HW and in driver at the same time.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Add tests for having an XDP program attached in the driver and
another one attached in HW simultaneously.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Allow netdevsim to accept driver and offload attachment of XDP
BPF programs at the same time.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Split the query of HW-attached program from the software one.
Introduce new .ndo_bpf command to query HW-attached program.
This will allow drivers to install different programs in HW
and SW at the same time.  Netlink can now also carry multiple
programs on dump (in which case mode will be set to
XDP_ATTACHED_MULTI and user has to check per-attachment point
attributes, IFLA_XDP_PROG_ID will not be present).  We reuse
IFLA_XDP_PROG_ID skb space for second mode, so rtnl_xdp_size()
doesn't need to be updated.

Note that the installation side is still not there, since all
drivers currently reject installing more than one program at
the time.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Basic operations drivers perform during xdp setup and query can
be moved to helpers in the core.  Encapsulate program and flags
into a structure and add helpers.  Note that the structure is
intended as the "main" program information source in the driver.
Most drivers will additionally place the program pointer in their
fast path or ring structures.

The helpers don't have a huge impact now, but they will
decrease the code duplication when programs can be installed
in HW and driver at the same time.  Encapsulating the basic
operations in helpers will hopefully also reduce the number
of changes to drivers which adopt them.

Helpers could really be static inline, but they depend on
definition of struct netdev_bpf which means they'd have
to be placed in netdevice.h, an already 4500 line header.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

prog_attached of struct netdev_bpf should have been superseded
by simply setting prog_id long time ago, but we kept it around
to allow offloading drivers to communicate attachment mode (drv
vs hw).  Subsequently drivers were also allowed to report back
attachment flags (prog_flags), and since nowadays only programs
attached will XDP_FLAGS_HW_MODE can get offloaded, we can tell
the attachment mode from the flags driver reports.  Remove
prog_attached member.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

In preparation for support of simultaneous driver and hardware XDP
support add per-mode attributes.  The catch-all IFLA_XDP_PROG_ID
will still be reported, but user space can now also access the
program ID in a new IFLA_XDP_<mode>_PROG_ID attribute.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Russell King says:

====================
Four further jit compiler improves for 32-bit ARM.
====================
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Improbe the 64-bit ALU implementation from:

  movw    r8, #65532
  movt    r8, #65535
  movw    r9, #65535
  movt    r9, #65535
  ldr     r7, [fp, #-44]
  adds    r7, r7, r8
  str     r7, [fp, #-44]
  ldr     r7, [fp, #-40]
  adc     r7, r7, r9
  str     r7, [fp, #-40]

to:

  movw    r8, #65532
  movt    r8, #65535
  movw    r9, #65535
  movt    r9, #65535
  ldrd    r6, [fp, #-44]
  adds    r6, r6, r8
  adc     r7, r7, r9
  strd    r6, [fp, #-44]
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Improve the 64-bit store implementation from:

  ldr     r6, [fp, #-8]
  str     r8, [r6]
  ldr     r6, [fp, #-8]
  mov     r7, #4
  add     r7, r6, r7
  str     r9, [r7]

to:

  ldr     r6, [fp, #-8]
  str     r8, [r6]
  str     r9, [r6, #4]

We leave the store as two separate STR instructions rather than using
STRD as the store may not be aligned, and STR can handle misalignment.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Improve the 64-bit sign-extended immediate from:

  mov     r6, #1
  str     r6, [fp, #-52]  ; 0xffffffcc
  mov     r6, #0
  str     r6, [fp, #-48]  ; 0xffffffd0

to:

  mov     r6, #1
  mov     r7, #0
  strd    r6, [fp, #-52]  ; 0xffffffcc
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Rather than writing each 32-bit half of the 64-bit immediate value
separately when the register is on the stack:

  movw    r6, #45056      ; 0xb000
  movt    r6, #60979      ; 0xee33
  str     r6, [fp, #-44]  ; 0xffffffd4
  mov     r6, #0
  str     r6, [fp, #-40]  ; 0xffffffd8

arrange to use the double-word store when available instead:

  movw    r6, #45056      ; 0xb000
  movt    r6, #60979      ; 0xee33
  mov     r7, #0
  strd    r6, [fp, #-44]  ; 0xffffffd4
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Russell King says:

====================
This series improves the ARM BPF JIT compiler by:

- enumerating the stack layout rather than using constants that happen
  to be multiples of four
- rejig the BPF "register" accesses to use negative numbers instead of
  positive, which could be confused with register numbers in the bpf2a32
  array.
- since we maintain the ARM FP register as a pointer to the top of our
  scratch space (or, with frame pointers enabled, a valid ARM frame
  pointer register), we can access our scratch space using FP, which is
  constant across all BPF programs, including tail-called programs.
- use immediate forms of ARM instructions where possible, rather than
  first loading the immediate into an ARM register.
- use load-with-shift instruction rather than seperate shift instruction
  followed by load
- avoid reloading index and array in the tail-call code
- use double-word load/store instructions where available

Version 2:

- Fix ARMv5 test pointed out by Olof
- Fix build error found by 0-day (adding an additional patch)
====================
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Use double-word load and stores where support for this instruction is
supported by the CPU architecture.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Always use an odd/even register pair for our 64-bit registers, so that
we're able to use the double-word load/store instructions in the future.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Rearranging the order of the initial tail call code a little allows is
to avoid reloading the 'array' pointer.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Avoid reloading 'index' after we have validated it - it remains in
tmp2[1] up to the point that we begin the code to index the pointer
array, so with a little rearrangement of the registers, we can use
the already loaded value.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Rather than pre-shifting the rm register for the ldr in the tail call,
shift it in the load instruction.  This eliminates one unnecessary
instruction.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Rather than moving constants to a register and then using them in a
subsequent instruction, use them directly in the desired instruction
cutting out the "middle" register.  This removes two instructions from
the tail call code path.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Provide a version of the imm8m() function that the compiler can optimise
when used with a constant expression.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Access the eBPF scratch space using the frame pointer rather than our
stack pointer, as the offsets from the ARM frame pointer are constant
across all eBPF programs.

Since we no longer reference the scratch space registers from the stack
pointer, this simplifies emit_push_r64() as it no longer needs to know
how many words are pushed onto the stack.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Provide a couple of 64-bit register accessors, and use them where
appropriate
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Many of the code paths need to have knowledge about whether a register
is stacked or in a CPU register.  Move this decision making to a pair
of helper functions instead of having it scattered throughout the
code.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The decision about whether a BPF register is on the stack or in a CPU
register is detected at the top BPF insn processing level, and then
percolated throughout the remainder of the code.  Since we now use
negative register values to represent stacked registers, we can detect
where a BPF register is stored without restoring to carrying this
additional metadata through all code paths.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Use negative numbers for eBPF registers that live on the stack.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Provide a set of load/store opcode generators that work with negative
immediates as well as positive ones.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Enumerate the contents of the JIT scratch stack layout used for storing
some of the JITs 64-bit registers, tail call counter and AX register.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Quentin Monnet says:

====================
The three patches in this series are related to the documentation for eBPF
helpers. The first patch brings minor formatting edits to the documentation
in include/uapi/linux/bpf.h, and the second one updates the related header
file under tools/.

The third patch adds a Makefile under tools/bpf for generating the
documentation (man pages) about eBPF helpers. The targets defined in this
file can also be called from the bpftool directory (please refer to
relevant commit logs for details).
====================
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Provide a new Makefile.helpers in tools/bpf, in order to build and
install the man page for eBPF helpers. This Makefile is also included in
the one used to build bpftool documentation, so that it can be called
either on its own (cd tools/bpf && make -f Makefile.helpers) or from
bpftool directory (cd tools/bpf/bpftool && make doc, or
cd tools/bpf/bpftool/Documentation && make helpers).

Makefile.helpers is not added directly to bpftool to avoid changing its
Makefile too much (helpers are not 100% directly related with bpftool).
But the possibility to build the page from bpftool directory makes us
able to package the helpers man page with bpftool, and to install it
along with bpftool documentation, so that the doc for helpers becomes
easily available to developers through the "man" program.

Cc: linux-man@vger.kernel.org
Suggested-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Update with latest changes from include/uapi/linux/bpf.h header.
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Minor formatting edits for eBPF helpers documentation, including blank
lines removal, fix of item list for return values in bpf_fib_lookup(),
and missing prefix on bpf_skb_load_bytes_relative().
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Jakub Kicinski says:

====================
This series starts with two minor clean ups to test_offload.py
selftest script.

The next 11 patches extend the abilities of bpftool prog load
beyond the simple cgroup use cases.  Three new parameters are
added:

 - type - allows specifying program type, independent of how
   code sections are named;
 - map  - allows reusing existing maps, instead of creating a new
   map on every program load;
 - dev  - offload/binding to a device.

A number of changes to libbpf is required to accomplish the task.
The section - program type logic mapping is exposed.  We should
probably aim to use the libbpf program section naming everywhere.
For reuse of maps we need to allow users to set FD for bpf map
object in libbpf.

Examples

Load program my_xdp.o and pin it as /sys/fs/bpf/my_xdp, for xdp
program type:

$ bpftool prog load my_xdp.o /sys/fs/bpf/my_xdp \
  type xdp

As above but for offload:

$ bpftool prog load my_xdp.o /sys/fs/bpf/my_xdp \
  type xdp \
  dev netdevsim0

Load program my_maps.o, but for the first map reuse map id 17,
and for the map called "other_map" reuse pinned map /sys/fs/bpf/map0:

$ bpftool prog load my_maps.o /sys/fs/bpf/prog \
  map idx 0 id 17 \
  map name other_map pinned /sys/fs/bpf/map0

v3:
 - fix return codes in patch 5;
 - rename libbpf_prog_type_by_string() -> libbpf_prog_type_by_name();
 - fold file path into xattr in patch 8;
 - add patch 10;
 - use dup3() in patch 12;
 - depend on fd value in patch 12;
 - close old fd in patch 12.
v2:
 - add compat for reallocarray().
====================
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Add map parameter to prog load which will allow reuse of existing
maps instead of creating new ones.

We need feature detection and compat code for reallocarray, since
it's not available in many libc versions.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>