netdev - [PATCH bpf-next 2/2] tools/bpf: bpftool: support prog array map and map of maps

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 6 Sep 2018 17:26:05 -0700
From:   Yonghong Song <yhs@...com>
To:     <ast@...com>, <daniel@...earbox.net>, <netdev@...r.kernel.org>
CC:     <kernel-team@...com>
Subject: [PATCH bpf-next 2/2] tools/bpf: bpftool: support prog array map and map of maps

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: Yonghong Song <yhs@...com>
---
 tools/bpf/bpftool/map.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index 9c55077ca5dd..af8ad32fa6e9 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -673,12 +673,6 @@ static int do_dump(int argc, char **argv)
 	if (fd < 0)
 		return -1;
 
-	if (map_is_map_of_maps(info.type) || map_is_map_of_progs(info.type)) {
-		p_err("Dumping maps of maps and program maps not supported");
-		close(fd);
-		return -1;
-	}
-
 	key = malloc(info.key_size);
 	value = alloc_value(&info);
 	if (!key || !value) {
@@ -732,7 +726,9 @@ static int do_dump(int argc, char **argv)
 				} else {
 					print_entry_plain(&info, key, value);
 				}
-		} else {
+			num_elems++;
+		} else if (!map_is_map_of_maps(info.type) &&
+			   !map_is_map_of_progs(info.type)) {
 			if (json_output) {
 				jsonw_name(json_wtr, "key");
 				print_hex_data_json(key, info.key_size);
@@ -749,7 +745,6 @@ static int do_dump(int argc, char **argv)
 		}
 
 		prev_key = key;
-		num_elems++;
 	}
 
 	if (json_output)
-- 
2.17.1