Lack of const in cgroup helpers signatures forces to write ugly client
code. Fix it.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Sync BPF_SOCK_OPS_TCP_LISTEN_CB related UAPI changes to tools/.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel 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: Okash Khawaja <osk@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel 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: Okash Khawaja <osk@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel 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: Okash Khawaja <osk@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel 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: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Daniel 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: Florian Maury <florian.maury-cv@x-cli.eu>
Reported-by: Marek Majkowski <marek@cloudflare.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel 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: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel 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: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel 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: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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

Russell King says:

====================
Four further jit compiler improves for 32-bit ARM.
====================
Signed-off-by: Daniel 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: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Daniel 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: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Daniel 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: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Daniel 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: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Daniel 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: Daniel Borkmann <daniel@iogearbox.net>

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

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

Use negative numbers for eBPF registers that live on the stack.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Daniel 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: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Daniel 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: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Daniel 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: Daniel 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: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

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