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 additional "effective" 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 (without 'effective' option)
# bpftool cgroup show /sys/fs/cgroup/cgroup-test-work-dir/cg1/
ID AttachType AttachFlags Name
129 egress multi pkt_cntr_1
130 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
131 egress override pkt_cntr_4
And with '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
131 egress override pkt_cntr_4
129 egress override pkt_cntr_1
130 egress override pkt_cntr_2
Signed-off-by: Takshak Chahande <ctaks...@fb.com>
---
Changelog:
v2:
- Removed global '-e|--effective' query flag
- Added 'effective' option after cgroup path argument as proposed by Jakub
.../bpftool/Documentation/bpftool-cgroup.rst | 17 +++--
tools/bpf/bpftool/bash-completion/bpftool | 15 +++--
tools/bpf/bpftool/cgroup.c | 66 ++++++++++++-------
3 files changed, 66 insertions(+), 32 deletions(-)
diff --git a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
index 585f270c2d25..8c12e8bb5dd4 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 +35,18 @@ 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, then it retrieves all the
+ effective programs that will be executed for events within
+ a cgroup. This includes inherited along with attached ones
+ to the cgroup.
+
+ **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 +55,10 @@ DESCRIPTION
commands: it starts with absolute cgroup path, followed by
program ID, attach type, attach flags and program name.
+ With **effective** it retrieves all the effective programs
+ that will be executed for events at each cgroup level as
+ similar to show/list command output for a cgroup.
+
**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 ba37095e1f62..b9b76b812dda 100644
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool
@@ -679,12 +679,15 @@ _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 390b89a224f1..09040dbdc20a 100644
--- a/tools/bpf/bpftool/cgroup.c
+++ b/tools/bpf/bpftool/cgroup.c
@@ -29,6 +29,7 @@
" 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 +108,8 @@ 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 +127,8 @@ 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 +160,32 @@ 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;
+ char *cgroup_path;
int cgroup_fd;
int ret = -1;
- if (argc < 1) {
+ if (!REQ_ARGS(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;
}
- cgroup_fd = open(argv[0], O_RDONLY);
+ query_flags = 0;
+ cgroup_path = GET_ARG();
+
+ if (argc) {
+ if (argc == 1 && is_prefix(*argv, "effective")) {
+ query_flags |= BPF_F_QUERY_EFFECTIVE;
+ NEXT_ARG();
+ } else {
+ p_err("invalid argument after cgroup path, "
+ "got: '%s'?, expect only effective", *argv);
+ goto exit;
+ }
+ }
+
+ cgroup_fd = open(cgroup_path, O_RDONLY);
if (cgroup_fd < 0) {
- p_err("can't open cgroup %s", argv[1]);
+ p_err("can't open cgroup %s", cgroup_path);
goto exit;
}
@@ -294,26 +308,34 @@ static char *find_cgroup_root(void)
static int do_show_tree(int argc, char **argv)
{
+ bool free_cg_root = false;
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;
+ free_cg_root = true;
+ } else {
+ cgroup_root = GET_ARG();
+
+ if (argc) {
+ if (argc == 1 && is_prefix(*argv, "effective")) {
+ query_flags |= BPF_F_QUERY_EFFECTIVE;
+ NEXT_ARG();
+ } else {
+ p_err("invalid argument after cgroup path, "
+ "got: '%s'? expect only effective",
*argv);
+ return -1;
+ }
+ }
}
-
if (json_output)
jsonw_start_array(json_wtr);
else
@@ -338,7 +360,7 @@ static int do_show_tree(int argc, char **argv)
if (json_output)
jsonw_end_array(json_wtr);
- if (argc == 0)
+ if (free_cg_root)
free(cgroup_root);
return ret;
@@ -459,8 +481,8 @@ 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"
--
2.17.1
