s/btf_get_from_id/btf__get_from_id/ to restore the API naming convention.
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NAndrey Ignatov <rdna@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Make the formatting for map_type_name array consistent.
Signed-off-by: NDavid Calavera <david.calavera@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

I noticed that these two new BPF Maps are not defined in bpftool.
This patch defines those two maps and adds their names to the
bpftool-map documentation.
Signed-off-by: NDavid Calavera <david.calavera@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The function get_btf() is implemented in tools/bpf/bpftool/map.c
to get a btf structure given a map_info. This patch
refactored this function to be function btf_get_from_id()
in tools/lib/bpf so that it can be used later.
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

bpftool output is not user friendly when dumping a map with only a few
populated entries:

    $ bpftool map
    1: devmap  name tx_devmap  flags 0x0
            key 4B  value 4B  max_entries 64  memlock 4096B
    2: array  name tx_idxmap  flags 0x0
            key 4B  value 4B  max_entries 64  memlock 4096B

    $ bpftool map dump id 1
    key:
    00 00 00 00
    value:
    No such file or directory
    key:
    01 00 00 00
    value:
    No such file or directory
    key:
    02 00 00 00
    value:
    No such file or directory
    key: 03 00 00 00  value: 03 00 00 00

Handle ENOENT by keeping the line format sane and dumping
"<no entry>" for the value

    $ bpftool map dump id 1
    key: 00 00 00 00  value: <no entry>
    key: 01 00 00 00  value: <no entry>
    key: 02 00 00 00  value: <no entry>
    key: 03 00 00 00  value: 03 00 00 00
    ...
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The limit for memory locked in the kernel by a process is usually set to
64 kbytes by default. This can be an issue when creating large BPF maps
and/or loading many programs. A workaround is to raise this limit for
the current process before trying to create a new BPF map. Changing the
hard limit requires the CAP_SYS_RESOURCE and can usually only be done by
root user (for non-root users, a call to setrlimit fails (and sets
errno) and the program simply goes on with its rlimit unchanged).

There is no API to get the current amount of memory locked for a user,
therefore we cannot raise the limit only when required. One solution,
used by bcc, is to try to create the map, and on getting a EPERM error,
raising the limit to infinity before giving another try. Another
approach, used in iproute2, is to raise the limit in all cases, before
trying to create the map.

Here we do the same as in iproute2: the rlimit is raised to infinity
before trying to load programs or to create maps with bpftool.
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Add a way of creating maps from user space.  The command takes
as parameters most of the attributes of the map creation system
call command.  After map is created its pinned to bpffs.  This makes
it possible to easily and dynamically (without rebuilding programs)
test various corner cases related to map creation.

Map type names are taken from bpftool's array used for printing.
In general these days we try to make use of libbpf type names, but
there are no map type names in libbpf as of today.

As with most features I add the motivation is testing (offloads) :)
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Since map lookup error can be ENOENT or EOPNOTSUPP, let's print
strerror() as error message in normal and JSON output.

This patch adds helper function print_entry_error() to print
entry from lookup error occurs

Example: Following example dumps a map which does not support lookup.

Output before:
root# bpftool map -jp dump id 40
[
    "key": ["0x0a","0x00","0x00","0x00"
    ],
    "value": {
        "error": "can\'t lookup element"
    },
    "key": ["0x0b","0x00","0x00","0x00"
    ],
    "value": {
        "error": "can\'t lookup element"
    }
]

root# bpftool map dump id 40
can't lookup element with key:
0a 00 00 00
can't lookup element with key:
0b 00 00 00
Found 0 elements

Output after changes:
root# bpftool map dump -jp  id 45
[
    "key": ["0x0a","0x00","0x00","0x00"
    ],
    "value": {
        "error": "Operation not supported"
    },
    "key": ["0x0b","0x00","0x00","0x00"
    ],
    "value": {
        "error": "Operation not supported"
    }
]

root# bpftool map dump id 45
key:
0a 00 00 00
value:
Operation not supported
key:
0b 00 00 00
value:
Operation not supported
Found 0 elements
Signed-off-by: NPrashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

do_dump() function in bpftool/map.c has deep indentations. In order
to reduce deep indent, let's move element printing code out of
do_dump() into dump_map_elem() function.
Signed-off-by: NPrashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

This commit adds support for BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE
map type.
Signed-off-by: NRoman Gushchin <guro@fb.com>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NSong Liu <songliubraving@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Add BPF_MAP_TYPE_REUSEPORT_SOCKARRAY map type to the list
of maps types which bpftool recognizes.
Signed-off-by: NRoman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Yonghong Song <yhs@fb.com>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Currently, prog array map and map of maps are not supported
in bpftool. This patch added the support.
Different from other map types, for prog array map and
map of maps, the key returned bpf_get_next_key() may not
point to a valid value. So for these two map types,
no error will be printed out when such a scenario happens.

The following is the plain and json dump if btf is not available:
  $ ./bpftool map dump id 10
    key: 08 00 00 00  value: 5c 01 00 00
    Found 1 element
  $ ./bpftool -jp map dump id 10
    [{
        "key": ["0x08","0x00","0x00","0x00"
        ],
        "value": ["0x5c","0x01","0x00","0x00"
        ]
    }]

If the BTF is available, the dump looks below:
  $ ./bpftool map dump id 2
    [{
            "key": 0,
            "value": 7
        }
    ]
  $ ./bpftool -jp map dump id 2
    [{
        "key": ["0x00","0x00","0x00","0x00"
        ],
        "value": ["0x07","0x00","0x00","0x00"
        ],
        "formatted": {
            "key": 0,
            "value": 7
        }
    }]
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

When listed all maps, bpftool currently shows (null) for xskmap.
Added xskmap type in map_type_name[] to show correct type.
Signed-off-by: NPrashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The btf pretty print is added to percpu arraymap,
percpu hashmap and percpu lru hashmap.
For each <key, value> pair, the following will be
added to plain/json output:

   {
       "key": <pretty_print_key>,
       "values": [{
             "cpu": 0,
             "value": <pretty_print_value_on_cpu0>
          },{
             "cpu": 1,
             "value": <pretty_print_value_on_cpu1>
          },{
          ....
          },{
             "cpu": n,
             "value": <pretty_print_value_on_cpun>
          }
       ]
   }

For example, the following could be part of plain or json formatted
output:
    {
        "key": 0,
        "values": [{
                "cpu": 0,
                "value": {
                    "ui32": 0,
                    "ui16": 0,
                }
            },{
                "cpu": 1,
                "value": {
                    "ui32": 1,
                    "ui16": 0,
                }
            },{
                "cpu": 2,
                "value": {
                    "ui32": 2,
                    "ui16": 0,
                }
            },{
                "cpu": 3,
                "value": {
                    "ui32": 3,
                    "ui16": 0,
                }
            }
        ]
    }
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Add BPF_MAP_TYPE_CGROUP_STORAGE maps to the list
of maps types which bpftool recognizes.
Signed-off-by: NRoman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

I hit the following problem when I tried to use bpftool
to dump a percpu array.

  $ sudo ./bpftool map show
  61: percpu_array  name stub  flags 0x0
          key 4B  value 4B  max_entries 1  memlock 4096B
  ...
  $ sudo ./bpftool map dump id 61
  bpftool: malloc.c:2406: sysmalloc: Assertion
  `(old_top == initial_top (av) && old_size == 0) || \
   ((unsigned long) (old_size) >= MINSIZE && \
   prev_inuse (old_top) && \
   ((unsigned long) old_end & (pagesize - 1)) == 0)'
  failed.
  Aborted

Further debugging revealed that this is due to
miscommunication between bpftool and kernel.
For example, for the above percpu_array with value size of 4B.
The map info returned to user space has value size of 4B.

In bpftool, the values array for lookup is allocated like:
   info->value_size * get_possible_cpus() = 4 * get_possible_cpus()
In kernel (kernel/bpf/syscall.c), the values array size is
rounded up to multiple of 8.
   round_up(map->value_size, 8) * num_possible_cpus()
   = 8 * num_possible_cpus()
So when kernel copies the values to user buffer, the kernel will
overwrite beyond user buffer boundary.

This patch fixed the issue by allocating and stepping through
percpu map value array properly in bpftool.

Fixes: 71bb428f ("tools: bpf: add bpftool")
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Fix inconsistent IS_ERR and PTR_ERR in get_btf,
the proper pointer to be passed as argument is '*btf'

This issue was detected with the help of Coccinelle.

Fixes: 2d3feca8 ("bpf: btf: print map dump and lookup with btf info")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
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>

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>

Drop my author comments, those are from the early days of
bpftool and make little sense in tree, where we have quite
a few people contributing and git to attribute the work.

While at it bump some copyrights.
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>

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

Users of BPF sooner or later discover perf_event_output() helpers
and BPF_MAP_TYPE_PERF_EVENT_ARRAY.  Dumping this array type is
not possible, however, we can add simple reading of perf events.
Create a new event_pipe subcommand for maps, this sub command
will only work with BPF_MAP_TYPE_PERF_EVENT_ARRAY maps.

Parts of the code from samples/bpf/trace_output_user.c.
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>

Move the get_possible_cpus() function to shared code.  No functional
changes.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: NJiong Wang <jiong.wang@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Instead of spelling [hex] BYTES everywhere use DATA as keyword
for generalized value.  This will help us keep the messages
concise when longer command are added in the future.  It will
also be useful once BTF support comes.  We will only have to
change the definition of DATA.
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>

bpftool uses hexadecimal values when it dumps map contents:

    # bpftool map dump id 1337
    key: ff 13 37 ff  value: a1 b2 c3 d4 ff ff ff ff
    Found 1 element

In order to lookup or update values with bpftool, the natural reflex is
then to copy and paste the values to the command line, and to try to run
something like:

    # bpftool map update id 1337 key ff 13 37 ff \
            value 00 00 00 00 00 00 1a 2b
    Error: error parsing byte: ff

bpftool complains, because it uses strtoul() with a 0 base to parse the
bytes, and that without a "0x" prefix, the bytes are considered as
decimal values (or even octal if they start with "0").

To feed hexadecimal values instead, one needs to add "0x" prefixes
everywhere necessary:

    # bpftool map update id 1337 key 0xff 0x13 0x37 0xff \
            value 0 0 0 0 0 0 0x1a 0x2b

To make it easier to use hexadecimal values, add an optional "hex"
keyword to put after "key" or "value" to tell bpftool to consider the
digits as hexadecimal. We can now do:

    # bpftool map update id 1337 key hex ff 13 37 ff \
            value hex 0 0 0 0 0 0 1a 2b

Without the "hex" keyword, the bytes are still parsed according to
normal integer notation (decimal if no prefix, or hexadecimal or octal
if "0x" or "0" prefix is used, respectively).

The patch also add related documentation and bash completion for the
"hex" keyword.
Suggested-by: NDaniel Borkmann <daniel@iogearbox.net>
Suggested-by: NDavid Beckett <david.beckett@netronome.com>
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

JSON does not accept hex numbers with 0x prefix.  Simply print
as decimal numbers, JSON should be primarily machine-readable.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Fixes: 831a0aaf ("tools: bpftool: add JSON output for `bpftool map *` commands")
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Add BPF_MAP_TYPE_CPUMAP map type to the list
of map type recognized by bpftool and define
corresponding text representation.
Signed-off-by: NRoman Gushchin <guro@fb.com>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Acked-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Print the information about device on which map is created.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

iproute2 seems to accept show and list as aliases.
Let's do the same thing, and by allowing both bring
cgroup syntax back in line with maps and progs.
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>

On program/map show we may get an ID of an object from GETNEXT,
but the object may disappear before we call GET_FD_BY_ID.  If
that happens, ignore the object and continue.

Fixes: 71bb428f ("tools: bpf: add bpftool")
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

We can't return from the middle of do_show(), because
json_array will not be closed.  Break out of the loop.
Note that the error handling after the loop depends on
errno, so no need to set err.

Fixes: 831a0aaf ("tools: bpftool: add JSON output for `bpftool map *` commands")
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Making it optional to show file names of pinned objects because
it scans complete bpf-fs filesystem which is costly.
Added option -f|--bpffs. Documentation updated.
Signed-off-by: NPrashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Added support to show filenames of pinned objects.

For example:

root@test# ./bpftool prog
3: tracepoint  name tracepoint__irq  tag f677a7dd722299a3
    loaded_at Oct 26/11:39  uid 0
    xlated 160B  not jited  memlock 4096B  map_ids 4
    pinned /sys/fs/bpf/softirq_prog

4: tracepoint  name tracepoint__irq  tag ea5dc530d00b92b6
    loaded_at Oct 26/11:39  uid 0
    xlated 392B  not jited  memlock 4096B  map_ids 4,6

root@test# ./bpftool --json --pretty prog
[{
        "id": 3,
        "type": "tracepoint",
        "name": "tracepoint__irq",
        "tag": "f677a7dd722299a3",
        "loaded_at": "Oct 26/11:39",
        "uid": 0,
        "bytes_xlated": 160,
        "jited": false,
        "bytes_memlock": 4096,
        "map_ids": [4
        ],
        "pinned": ["/sys/fs/bpf/softirq_prog"
        ]
    },{
        "id": 4,
        "type": "tracepoint",
        "name": "tracepoint__irq",
        "tag": "ea5dc530d00b92b6",
        "loaded_at": "Oct 26/11:39",
        "uid": 0,
        "bytes_xlated": 392,
        "jited": false,
        "bytes_memlock": 4096,
        "map_ids": [4,6
        ],
        "pinned": []
    }
]

root@test# ./bpftool map
4: hash  name start  flags 0x0
    key 4B  value 16B  max_entries 10240  memlock 1003520B
    pinned /sys/fs/bpf/softirq_map1
5: hash  name iptr  flags 0x0
    key 4B  value 8B  max_entries 10240  memlock 921600B

root@test# ./bpftool --json --pretty map
[{
        "id": 4,
        "type": "hash",
        "name": "start",
        "flags": 0,
        "bytes_key": 4,
        "bytes_value": 16,
        "max_entries": 10240,
        "bytes_memlock": 1003520,
        "pinned": ["/sys/fs/bpf/softirq_map1"
        ]
    },{
        "id": 5,
        "type": "hash",
        "name": "iptr",
        "flags": 0,
        "bytes_key": 4,
        "bytes_value": 8,
        "max_entries": 10240,
        "bytes_memlock": 921600,
        "pinned": []
    }
]
Signed-off-by: NPrashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Update the documentation to provide help about JSON output generation,
and add an example in bpftool-prog manual page.

Also reintroduce an example that was left aside when the tool was moved
from GitHub to the kernel sources, in order to show how to mount the
bpffs file system (to pin programs) inside the bpftool-prog manual page.
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As all commands can now return JSON output (possibly just a "null"
value), output of `bpftool --json batch file FILE` should also be fully
JSON compliant.
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Turn err() and info() macros into functions.

In order to avoid naming conflicts with variables in the code, rename
them as p_err() and p_info() respectively.

The behavior of these functions is similar to the one of the macros for
plain output. However, when JSON output is requested, these macros
return a JSON-formatted "error" object instead of printing a message to
stderr.

To handle error messages correctly with JSON, a modification was brought
to their behavior nonetheless: the functions now append a end-of-line
character at the end of the message. This way, we can remove end-of-line
characters at the end of the argument strings, and not have them in the
JSON output.

All error messages are formatted to hold in a single call to p_err(), in
order to produce a single JSON field.
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reuse the json_writer API introduced in an earlier commit to make
bpftool able to generate JSON output on
`bpftool map { show | dump | lookup | getnext }` commands. Remaining
commands produce no output.

Some functions have been spit into plain-output and JSON versions in
order to remain readable.

Outputs for sample maps have been successfully tested against a JSON
validator.
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make error messages more consistent. Specifically, when bpftool fails at
parsing map key bytes, make it print a single error message to stderr
and return from the function, instead of (always) printing a second
error message afterwards.
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make print_hex() able to print to any file instead of standard output
only, and rename it to fprint_hex(). The function can now be called with
the info() macro, for example, without splitting the output between
standard and error outputs.
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a simple tool for querying and updating BPF objects on the system.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>