linux-toradex.git/tools/bpf/bpftool/map.c, branch v4.15

tools: bpftool: protect against races with disappearing objects

2017-12-23T00:09:52+00:00

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: 71bb428fe2c1 ("tools: bpf: add bpftool")
Signed-off-by: Jakub Kicinski 
Acked-by: Quentin Monnet 
Signed-off-by: Daniel Borkmann

tools: bpftool: maps: close json array on error paths of show

2017-12-23T00:09:52+00:00

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: 831a0aafe5c3 ("tools: bpftool: add JSON output for `bpftool map *` commands")
Signed-off-by: Jakub Kicinski 
Acked-by: Quentin Monnet 
Signed-off-by: Daniel Borkmann

tools: bpftool: optionally show filenames of pinned objects

2017-11-11T03:35:41+00:00

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: Prashant Bhole 
Signed-off-by: David S. Miller

tools: bpftool: show filenames of pinned objects

2017-11-11T03:35:41+00:00

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: Prashant Bhole 
Signed-off-by: David S. Miller

tools: bpftool: update documentation for --json and --pretty usage

2017-10-24T00:25:09+00:00

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: Quentin Monnet 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

tools: bpftool: provide JSON output for all possible commands

2017-10-24T00:25:09+00:00

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: Quentin Monnet 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

tools: bpftool: turn err() and info() macros into functions

2017-10-24T00:25:09+00:00

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: Quentin Monnet 
Acked-by: Jakub Kicinski 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

tools: bpftool: add JSON output for `bpftool map *` commands

2017-10-24T00:25:09+00:00

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: Quentin Monnet 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

tools: bpftool: print only one error message on byte parsing failure

2017-10-22T01:11:32+00:00

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: Quentin Monnet 
Signed-off-by: Jakub Kicinski 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

tools: bpftool: add pointer to file argument to print_hex()

2017-10-22T01:11:31+00:00

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: Quentin Monnet 
Signed-off-by: Jakub Kicinski 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller