From 596f5fb2ea2a38032abb8043606ce7168f21f6ab Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Tue, 28 Jun 2022 10:43:13 -0700 Subject: [PATCH] bpftool: implement cgroup tree for BPF_LSM_CGROUP $ bpftool --nomount prog loadall $KDIR/tools/testing/selftests/bpf/lsm_cgroup.o /sys/fs/bpf/x $ bpftool cgroup attach /sys/fs/cgroup lsm_cgroup pinned /sys/fs/bpf/x/socket_alloc $ bpftool cgroup attach /sys/fs/cgroup lsm_cgroup pinned /sys/fs/bpf/x/socket_bind $ bpftool cgroup attach /sys/fs/cgroup lsm_cgroup pinned /sys/fs/bpf/x/socket_clone $ bpftool cgroup attach /sys/fs/cgroup lsm_cgroup pinned /sys/fs/bpf/x/socket_post_create $ bpftool cgroup tree CgroupPath ID AttachType AttachFlags Name /sys/fs/cgroup 6 lsm_cgroup socket_post_create bpf_lsm_socket_post_create 8 lsm_cgroup socket_bind bpf_lsm_socket_bind 10 lsm_cgroup socket_alloc bpf_lsm_sk_alloc_security 11 lsm_cgroup socket_clone bpf_lsm_inet_csk_clone $ bpftool cgroup detach /sys/fs/cgroup lsm_cgroup pinned /sys/fs/bpf/x/socket_post_create $ bpftool cgroup tree CgroupPath ID AttachType AttachFlags Name /sys/fs/cgroup 8 lsm_cgroup socket_bind bpf_lsm_socket_bind 10 lsm_cgroup socket_alloc bpf_lsm_sk_alloc_security 11 lsm_cgroup socket_clone bpf_lsm_inet_csk_clone Reviewed-by: Quentin Monnet Acked-by: Martin KaFai Lau Signed-off-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20220628174314.1216643-11-sdf@google.com Signed-off-by: Alexei Starovoitov --- tools/bpf/bpftool/cgroup.c | 109 ++++++++++++++++++++++++++++++++++++--------- 1 file changed, 87 insertions(+), 22 deletions(-) diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c index 42421fe..cced668 100644 --- a/tools/bpf/bpftool/cgroup.c +++ b/tools/bpf/bpftool/cgroup.c @@ -15,6 +15,7 @@ #include #include +#include #include "main.h" @@ -36,6 +37,8 @@ " cgroup_inet_sock_release }" static unsigned int query_flags; +static struct btf *btf_vmlinux; +static __u32 btf_vmlinux_id; static enum bpf_attach_type parse_attach_type(const char *str) { @@ -64,11 +67,38 @@ static enum bpf_attach_type parse_attach_type(const char *str) return __MAX_BPF_ATTACH_TYPE; } +static void guess_vmlinux_btf_id(__u32 attach_btf_obj_id) +{ + struct bpf_btf_info btf_info = {}; + __u32 btf_len = sizeof(btf_info); + char name[16] = {}; + int err; + int fd; + + btf_info.name = ptr_to_u64(name); + btf_info.name_len = sizeof(name); + + fd = bpf_btf_get_fd_by_id(attach_btf_obj_id); + if (fd < 0) + return; + + err = bpf_obj_get_info_by_fd(fd, &btf_info, &btf_len); + if (err) + goto out; + + if (btf_info.kernel_btf && strncmp(name, "vmlinux", sizeof(name)) == 0) + btf_vmlinux_id = btf_info.id; + +out: + close(fd); +} + static int show_bpf_prog(int id, enum bpf_attach_type attach_type, const char *attach_flags_str, int level) { char prog_name[MAX_PROG_FULL_NAME]; + const char *attach_btf_name = NULL; struct bpf_prog_info info = {}; const char *attach_type_str; __u32 info_len = sizeof(info); @@ -84,6 +114,20 @@ static int show_bpf_prog(int id, enum bpf_attach_type attach_type, } attach_type_str = libbpf_bpf_attach_type_str(attach_type); + + if (btf_vmlinux) { + if (!btf_vmlinux_id) + guess_vmlinux_btf_id(info.attach_btf_obj_id); + + if (btf_vmlinux_id == info.attach_btf_obj_id && + info.attach_btf_id < btf__type_cnt(btf_vmlinux)) { + const struct btf_type *t = + btf__type_by_id(btf_vmlinux, info.attach_btf_id); + attach_btf_name = + btf__name_by_offset(btf_vmlinux, t->name_off); + } + } + get_prog_full_name(&info, prog_fd, prog_name, sizeof(prog_name)); if (json_output) { jsonw_start_object(json_wtr); @@ -95,6 +139,10 @@ static int show_bpf_prog(int id, enum bpf_attach_type attach_type, jsonw_string_field(json_wtr, "attach_flags", attach_flags_str); jsonw_string_field(json_wtr, "name", prog_name); + if (attach_btf_name) + jsonw_string_field(json_wtr, "attach_btf_name", attach_btf_name); + jsonw_uint_field(json_wtr, "attach_btf_obj_id", info.attach_btf_obj_id); + jsonw_uint_field(json_wtr, "attach_btf_id", info.attach_btf_id); jsonw_end_object(json_wtr); } else { printf("%s%-8u ", level ? " " : "", info.id); @@ -102,7 +150,13 @@ static int show_bpf_prog(int id, enum bpf_attach_type attach_type, printf("%-15s", attach_type_str); else printf("type %-10u", attach_type); - printf(" %-15s %-15s\n", attach_flags_str, prog_name); + printf(" %-15s %-15s", attach_flags_str, prog_name); + if (attach_btf_name) + printf(" %-15s", attach_btf_name); + else if (info.attach_btf_id) + printf(" attach_btf_obj_id=%d attach_btf_id=%d", + info.attach_btf_obj_id, info.attach_btf_id); + printf("\n"); } close(prog_fd); @@ -144,40 +198,49 @@ static int cgroup_has_attached_progs(int cgroup_fd) static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type, int level) { + LIBBPF_OPTS(bpf_prog_query_opts, p); + __u32 prog_attach_flags[1024] = {0}; const char *attach_flags_str; __u32 prog_ids[1024] = {0}; - __u32 prog_cnt, iter; - __u32 attach_flags; char buf[32]; + __u32 iter; int ret; - prog_cnt = ARRAY_SIZE(prog_ids); - ret = bpf_prog_query(cgroup_fd, type, query_flags, &attach_flags, - prog_ids, &prog_cnt); + p.query_flags = query_flags; + p.prog_cnt = ARRAY_SIZE(prog_ids); + p.prog_ids = prog_ids; + p.prog_attach_flags = prog_attach_flags; + + ret = bpf_prog_query_opts(cgroup_fd, type, &p); if (ret) return ret; - if (prog_cnt == 0) + if (p.prog_cnt == 0) return 0; - switch (attach_flags) { - case BPF_F_ALLOW_MULTI: - attach_flags_str = "multi"; - break; - case BPF_F_ALLOW_OVERRIDE: - attach_flags_str = "override"; - break; - case 0: - attach_flags_str = ""; - break; - default: - snprintf(buf, sizeof(buf), "unknown(%x)", attach_flags); - attach_flags_str = buf; - } + for (iter = 0; iter < p.prog_cnt; iter++) { + __u32 attach_flags; + + attach_flags = prog_attach_flags[iter] ?: p.attach_flags; + + switch (attach_flags) { + case BPF_F_ALLOW_MULTI: + attach_flags_str = "multi"; + break; + case BPF_F_ALLOW_OVERRIDE: + attach_flags_str = "override"; + break; + case 0: + attach_flags_str = ""; + break; + default: + snprintf(buf, sizeof(buf), "unknown(%x)", attach_flags); + attach_flags_str = buf; + } - for (iter = 0; iter < prog_cnt; iter++) show_bpf_prog(prog_ids[iter], type, attach_flags_str, level); + } return 0; } @@ -233,6 +296,7 @@ static int do_show(int argc, char **argv) printf("%-8s %-15s %-15s %-15s\n", "ID", "AttachType", "AttachFlags", "Name"); + btf_vmlinux = libbpf_find_kernel_btf(); for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) { /* * Not all attach types may be supported, so it's expected, @@ -296,6 +360,7 @@ static int do_show_tree_fn(const char *fpath, const struct stat *sb, printf("%s\n", fpath); } + btf_vmlinux = libbpf_find_kernel_btf(); for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) show_attached_bpf_progs(cgroup_fd, type, ftw->level); -- 2.7.4