[PATCH net-next 5/5] bpftool: implement cglist command

From: Roman Gushchin
Date: Thu Nov 30 2017 - 08:44:26 EST


Implement cgattach command to list bpf progrrams attached
to the given cgroup:

Example:
$ ./bpftool cgattach dev_cgroup.o /sys/fs/cgroup/user.slice/ device
$ ./bpftool cglist /sys/fs/cgroup/user.slice/
ID AttachType Name
1 device bpf_prog1

Signed-off-by: Roman Gushchin <guro@xxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
Cc: Martin KaFai Lau <kafai@xxxxxx>
---
tools/bpf/bpftool/main.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 81 insertions(+), 1 deletion(-)

diff --git a/tools/bpf/bpftool/main.c b/tools/bpf/bpftool/main.c
index 77fcc1a0bd5d..8a48f6a32adc 100644
--- a/tools/bpf/bpftool/main.c
+++ b/tools/bpf/bpftool/main.c
@@ -82,12 +82,13 @@ static int do_help(int argc, char **argv)
" %s batch file FILE\n"
" %s cgattach FILE CGROUP TYPE\n"
" %s cgdetach CGROUP TYPE ID\n"
+ " %s cglist CGROUP TYPE\n"
" %s version\n"
"\n"
" OBJECT := { prog | map }\n"
" " HELP_SPEC_OPTIONS "\n"
"",
- bin_name, bin_name, bin_name, bin_name, bin_name);
+ bin_name, bin_name, bin_name, bin_name, bin_name, bin_name);

return 0;
}
@@ -168,6 +169,7 @@ void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
static int do_batch(int argc, char **argv);
static int do_cgattach(int argc, char **argv);
static int do_cgdetach(int argc, char **argv);
+static int do_cglist(int argc, char **argv);

static const struct cmd cmds[] = {
{ "help", do_help },
@@ -176,6 +178,7 @@ static const struct cmd cmds[] = {
{ "map", do_map },
{ "cgattach", do_cgattach },
{ "cgdetach", do_cgdetach },
+ { "cglist", do_cglist },
{ "version", do_version },
{ 0 }
};
@@ -386,6 +389,83 @@ static int do_cgdetach(int argc, char **argv)
return 0;
}

+static int do_cglist(int argc, char **argv)
+{
+ enum bpf_attach_type type;
+ int prog_fd, cgroup_fd;
+ __u32 attach_flags;
+ __u32 prog_ids[1024] = {0};
+ __u32 prog_cnt, iter;
+ int ret = -1;
+ struct bpf_prog_info info = {};
+ __u32 info_len = sizeof(info);
+
+ if (argc < 1) {
+ p_err("too few parameters for cglist\n");
+ return -1;
+ } else if (argc > 1) {
+ p_err("too many parameters for cglist\n");
+ return -1;
+ }
+
+ cgroup_fd = open(argv[0], O_RDONLY);
+ if (cgroup_fd < 0) {
+ p_err("can't open cgroup %s\n", argv[1]);
+ return -1;
+ }
+
+ if (json_output)
+ jsonw_start_array(json_wtr);
+
+ for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) {
+ prog_cnt = ARRAY_SIZE(prog_ids);
+ if (bpf_prog_query(cgroup_fd, type, 0, &attach_flags, prog_ids,
+ &prog_cnt))
+ continue;
+
+ ret = 0;
+
+ if (prog_cnt == 0)
+ continue;
+
+ if (!json_output)
+ printf("%-8s %-15s %-15s\n", "ID", "AttachType",
+ "Name");
+
+ for (iter = 0; iter < prog_cnt; iter++) {
+ prog_fd = bpf_prog_get_fd_by_id(prog_ids[iter]);
+ if (prog_fd < 0)
+ continue;
+
+ if (bpf_obj_get_info_by_fd(prog_fd, &info, &info_len)) {
+ close(prog_fd);
+ continue;
+ }
+
+ if (json_output) {
+ jsonw_start_object(json_wtr);
+ jsonw_uint_field(json_wtr, "id", info.id);
+ jsonw_string_field(json_wtr, "attach_type",
+ attach_type_strings[type]);
+ jsonw_string_field(json_wtr, "name", info.name);
+ jsonw_end_object(json_wtr);
+ } else {
+ printf("%-8u %-15s %-15s\n", info.id,
+ attach_type_strings[type], info.name);
+ }
+
+ close(prog_fd);
+ }
+ }
+
+ if (json_output)
+ jsonw_end_array(json_wtr);
+
+ close(cgroup_fd);
+
+ return ret;
+}
+
int main(int argc, char **argv)
{
static const struct option options[] = {
--
2.14.3