Takshak said in the original submission:
With different bpf attach_flags available to attach bpf programs specially
with BPF_F_ALLOW_OVERRIDE and BPF_F_ALLOW_MULTI, the list of effective
bpf-programs available to any sub-cgroups really needs to be available for
easy debugging.
Using BPF_F_QUERY_EFFECTIVE flag, one can get the list of not only attached
bpf-programs to a cgroup but also the inherited ones from parent cgroup.
So a new option is introduced to use BPF_F_QUERY_EFFECTIVE query flag here
to list all the effective bpf-programs available for execution at a specified
cgroup.
Reused modified test program test_cgroup_attach from tools/testing/selftests/bpf:
# ./test_cgroup_attach
With old bpftool:
# bpftool cgroup show /sys/fs/cgroup/cgroup-test-work-dir/cg1/
ID AttachType AttachFlags Name
271 egress multi pkt_cntr_1
272 egress multi pkt_cntr_2
Attached new program pkt_cntr_4 in cg2 gives following:
# bpftool cgroup show /sys/fs/cgroup/cgroup-test-work-dir/cg1/cg2
ID AttachType AttachFlags Name
273 egress override pkt_cntr_4
And with new "effective" option it shows all effective programs for cg2:
# bpftool cgroup show /sys/fs/cgroup/cgroup-test-work-dir/cg1/cg2 effective
ID AttachType AttachFlags Name
273 egress override pkt_cntr_4
271 egress override pkt_cntr_1
272 egress override pkt_cntr_2
Compared to original submission use a local flag instead of global
option.
We need to clear query_flags on every command, in case batch mode
wants to use varying settings.
Signed-off-by: Takshak Chahande <ctakshak@xxxxxx>
Signed-off-by: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
Reviewed-by: Quentin Monnet <quentin.monnet@xxxxxxxxxxxxx>
---
.../bpftool/Documentation/bpftool-cgroup.rst | 16 +++--
tools/bpf/bpftool/bash-completion/bpftool | 15 +++--
tools/bpf/bpftool/cgroup.c | 65 ++++++++++++-------
3 files changed, 63 insertions(+), 33 deletions(-)
diff --git a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
index 585f270c2d25..06a28b07787d 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
@@ -20,8 +20,8 @@ SYNOPSIS
CGROUP COMMANDS
===============
-| **bpftool** **cgroup { show | list }** *CGROUP*
-| **bpftool** **cgroup tree** [*CGROUP_ROOT*]
+| **bpftool** **cgroup { show | list }** *CGROUP* [**effective**]
+| **bpftool** **cgroup tree** [*CGROUP_ROOT*] [**effective**]
| **bpftool** **cgroup attach** *CGROUP* *ATTACH_TYPE* *PROG* [*ATTACH_FLAGS*]
| **bpftool** **cgroup detach** *CGROUP* *ATTACH_TYPE* *PROG*
| **bpftool** **cgroup help**
@@ -35,13 +35,17 @@ CGROUP COMMANDS
DESCRIPTION
===========
- **bpftool cgroup { show | list }** *CGROUP*
+ **bpftool cgroup { show | list }** *CGROUP* [**effective**]
List all programs attached to the cgroup *CGROUP*.
Output will start with program ID followed by attach type,
attach flags and program name.
- **bpftool cgroup tree** [*CGROUP_ROOT*]
+ If **effective** is specified retrieve effective programs that
+ will execute for events within a cgroup. This includes
+ inherited along with attached ones.
+
+ **bpftool cgroup tree** [*CGROUP_ROOT*] [**effective**]
Iterate over all cgroups in *CGROUP_ROOT* and list all
attached programs. If *CGROUP_ROOT* is not specified,
bpftool uses cgroup v2 mountpoint.
@@ -50,6 +54,10 @@ DESCRIPTION
commands: it starts with absolute cgroup path, followed by
program ID, attach type, attach flags and program name.
+ If **effective** is specified retrieve effective programs that
+ will execute for events within a cgroup. This includes
+ inherited along with attached ones.
+
**bpftool cgroup attach** *CGROUP* *ATTACH_TYPE* *PROG* [*ATTACH_FLAGS*]
Attach program *PROG* to the cgroup *CGROUP* with attach type
*ATTACH_TYPE* and optional *ATTACH_FLAGS*.
diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
index 6b961a5ed100..df16c5415444 100644
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool
@@ -710,12 +710,15 @@ _bpftool()
;;
cgroup)
case $command in
- show|list)
- _filedir
- return 0
- ;;
- tree)
- _filedir
+ show|list|tree)
+ case $cword in
+ 3)
+ _filedir
+ ;;
+ 4)
+ COMPREPLY=( $( compgen -W 'effective' -- "$cur" ) )
+ ;;
+ esac
return 0
;;
attach|detach)
diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c
index f3c05b08c68c..339c2c78b8e4 100644
--- a/tools/bpf/bpftool/cgroup.c
+++ b/tools/bpf/bpftool/cgroup.c
@@ -29,6 +29,8 @@
" recvmsg4 | recvmsg6 | sysctl |\n" \
" getsockopt | setsockopt }"
+static unsigned int query_flags;
+
static const char * const attach_type_strings[] = {
[BPF_CGROUP_INET_INGRESS] = "ingress",
[BPF_CGROUP_INET_EGRESS] = "egress",
@@ -107,7 +109,8 @@ static int count_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type)
__u32 prog_cnt = 0;
int ret;
- ret = bpf_prog_query(cgroup_fd, type, 0, NULL, NULL, &prog_cnt);
+ ret = bpf_prog_query(cgroup_fd, type, query_flags, NULL,
+ NULL, &prog_cnt);
if (ret)
return -1;
@@ -125,8 +128,8 @@ static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type,
int ret;
prog_cnt = ARRAY_SIZE(prog_ids);
- ret = bpf_prog_query(cgroup_fd, type, 0, &attach_flags, prog_ids,
- &prog_cnt);
+ ret = bpf_prog_query(cgroup_fd, type, query_flags, &attach_flags,
+ prog_ids, &prog_cnt);
if (ret)
return ret;
@@ -158,20 +161,30 @@ static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type,
static int do_show(int argc, char **argv)
{
enum bpf_attach_type type;
+ const char *path;
int cgroup_fd;
int ret = -1;
- if (argc < 1) {
- p_err("too few parameters for cgroup show");
- goto exit;
- } else if (argc > 1) {
- p_err("too many parameters for cgroup show");
- goto exit;
+ query_flags = 0;
+
+ if (!REQ_ARGS(1))
+ return -1;
+ path = GET_ARG();
+
+ while (argc) {
+ if (is_prefix(*argv, "effective")) {
+ query_flags |= BPF_F_QUERY_EFFECTIVE;
+ NEXT_ARG();
+ } else {
+ p_err("expected no more arguments, 'effective', got: '%s'?",
+ *argv);
+ return -1;
+ }
}
- cgroup_fd = open(argv[0], O_RDONLY);
+ cgroup_fd = open(path, O_RDONLY);
if (cgroup_fd < 0) {
- p_err("can't open cgroup %s", argv[0]);
+ p_err("can't open cgroup %s", path);
goto exit;
}
@@ -297,23 +310,29 @@ static int do_show_tree(int argc, char **argv)
char *cgroup_root;
int ret;
- switch (argc) {
- case 0:
+ query_flags = 0;
+
+ if (!argc) {
cgroup_root = find_cgroup_root();
if (!cgroup_root) {
p_err("cgroup v2 isn't mounted");
return -1;
}
- break;
- case 1:
- cgroup_root = argv[0];
- break;
- default:
- p_err("too many parameters for cgroup tree");
- return -1;
+ } else {
+ cgroup_root = GET_ARG();
+
+ while (argc) {
+ if (is_prefix(*argv, "effective")) {
+ query_flags |= BPF_F_QUERY_EFFECTIVE;
+ NEXT_ARG();
+ } else {
+ p_err("expected no more arguments, 'effective', got: '%s'?",
+ *argv);
+ return -1;
+ }
+ }
}
-
if (json_output)
jsonw_start_array(json_wtr);
else
@@ -459,8 +478,8 @@ static int do_help(int argc, char **argv)
}
fprintf(stderr,
- "Usage: %s %s { show | list } CGROUP\n"
- " %s %s tree [CGROUP_ROOT]\n"
+ "Usage: %s %s { show | list } CGROUP [**effective**]\n"
+ " %s %s tree [CGROUP_ROOT] [**effective**]\n"
" %s %s attach CGROUP ATTACH_TYPE PROG [ATTACH_FLAGS]\n"
" %s %s detach CGROUP ATTACH_TYPE PROG\n"
" %s %s help\n"
--
2.21.0
