bpftool: Improve handling of ENOENT on map dumps (bf598a8f) · Commits · 戴 / test

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:

David Ahern <dsahern@gmail.com> Acked-by:

Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by:

Daniel Borkmann <daniel@iogearbox.net>

tools/bpf/bpftool/map.c

+14 −4

Original line number	Diff line number	Diff line
		@@ -383,7 +383,10 @@ static void print_entry_plain(struct bpf_map_info info, unsigned char key,
		printf(single_line ? " " : "\n");

		printf("value:%c", break_names ? '\n' : ' ');
		if (value)
		fprint_hex(stdout, value, info->value_size, " ");
		else
		printf("<no entry>");

		printf("\n");
		} else {
		@@ -398,8 +401,11 @@ static void print_entry_plain(struct bpf_map_info info, unsigned char key,
		for (i = 0; i < n; i++) {
		printf("value (CPU %02d):%c",
		i, info->value_size > 16 ? '\n' : ' ');
		if (value)
		fprint_hex(stdout, value + i * step,
		info->value_size, " ");
		else
		printf("<no entry>");
		printf("\n");
		}
		}
		@@ -731,7 +737,11 @@ static int dump_map_elem(int fd, void key, void value,
		jsonw_string_field(json_wtr, "error", strerror(lookup_errno));
		jsonw_end_object(json_wtr);
		} else {
		print_entry_error(map_info, key, strerror(lookup_errno));
		if (errno == ENOENT)
		print_entry_plain(map_info, key, NULL);
		else
		print_entry_error(map_info, key,
		strerror(lookup_errno));
		}

		return 0;

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