From a98bf57391a24a68ec8381b9d35b60c2bee79150 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 30 Jul 2019 14:03:00 -0700 Subject: [PATCH] tools: bpftool: add support for reporting the effective cgroup progs 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. v2: (Takshak) - forbid duplicated flags; - fix cgroup path freeing. Signed-off-by: Takshak Chahande Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Reviewed-by: Takshak Chahande Signed-off-by: Alexei Starovoitov --- tools/bpf/bpftool/Documentation/bpftool-cgroup.rst | 16 +++-- tools/bpf/bpftool/bash-completion/bpftool | 15 ++-- tools/bpf/bpftool/cgroup.c | 83 ++++++++++++++-------- 3 files changed, 76 insertions(+), 38 deletions(-) diff --git a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst index 585f270..06a28b0 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 6b961a5..df16c54 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 f3c05b0..44352b5 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 +161,34 @@ 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")) { + if (query_flags & BPF_F_QUERY_EFFECTIVE) { + p_err("duplicated argument: %s", *argv); + return -1; + } + 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; } @@ -294,26 +311,37 @@ static char *find_cgroup_root(void) static int do_show_tree(int argc, char **argv) { - char *cgroup_root; + char *cgroup_root, *cgroup_alloced = NULL; int ret; - switch (argc) { - case 0: - cgroup_root = find_cgroup_root(); - if (!cgroup_root) { + query_flags = 0; + + if (!argc) { + cgroup_alloced = find_cgroup_root(); + if (!cgroup_alloced) { 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; + cgroup_root = cgroup_alloced; + } else { + cgroup_root = GET_ARG(); + + while (argc) { + if (is_prefix(*argv, "effective")) { + if (query_flags & BPF_F_QUERY_EFFECTIVE) { + p_err("duplicated argument: %s", *argv); + return -1; + } + 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 @@ -338,8 +366,7 @@ static int do_show_tree(int argc, char **argv) if (json_output) jsonw_end_array(json_wtr); - if (argc == 0) - free(cgroup_root); + free(cgroup_alloced); return ret; } @@ -459,8 +486,8 @@ 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" -- 2.7.4