diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/bpf/bpftool/cgroup.c | 524 |
1 files changed, 524 insertions, 0 deletions
diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c new file mode 100644 index 000000000..6e53b1d39 --- /dev/null +++ b/tools/bpf/bpftool/cgroup.c @@ -0,0 +1,524 @@ +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +// Copyright (C) 2017 Facebook +// Author: Roman Gushchin <guro@fb.com> + +#define _XOPEN_SOURCE 500 +#include <errno.h> +#include <fcntl.h> +#include <ftw.h> +#include <mntent.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> + +#include <bpf/bpf.h> + +#include "main.h" + +#define HELP_SPEC_ATTACH_FLAGS \ + "ATTACH_FLAGS := { multi | override }" + +#define HELP_SPEC_ATTACH_TYPES \ + " ATTACH_TYPE := { ingress | egress | sock_create |\n" \ + " sock_ops | device | bind4 | bind6 |\n" \ + " post_bind4 | post_bind6 | connect4 |\n" \ + " connect6 | getpeername4 | getpeername6 |\n" \ + " getsockname4 | getsockname6 | sendmsg4 |\n" \ + " sendmsg6 | recvmsg4 | recvmsg6 |\n" \ + " sysctl | getsockopt | setsockopt |\n" \ + " sock_release }" + +static unsigned int query_flags; + +static enum bpf_attach_type parse_attach_type(const char *str) +{ + enum bpf_attach_type type; + + for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) { + if (attach_type_name[type] && + is_prefix(str, attach_type_name[type])) + return type; + } + + return __MAX_BPF_ATTACH_TYPE; +} + +static int show_bpf_prog(int id, enum bpf_attach_type attach_type, + const char *attach_flags_str, + int level) +{ + struct bpf_prog_info info = {}; + __u32 info_len = sizeof(info); + int prog_fd; + + prog_fd = bpf_prog_get_fd_by_id(id); + if (prog_fd < 0) + return -1; + + if (bpf_obj_get_info_by_fd(prog_fd, &info, &info_len)) { + close(prog_fd); + return -1; + } + + if (json_output) { + jsonw_start_object(json_wtr); + jsonw_uint_field(json_wtr, "id", info.id); + if (attach_type < ARRAY_SIZE(attach_type_name)) + jsonw_string_field(json_wtr, "attach_type", + attach_type_name[attach_type]); + else + jsonw_uint_field(json_wtr, "attach_type", attach_type); + jsonw_string_field(json_wtr, "attach_flags", + attach_flags_str); + jsonw_string_field(json_wtr, "name", info.name); + jsonw_end_object(json_wtr); + } else { + printf("%s%-8u ", level ? " " : "", info.id); + if (attach_type < ARRAY_SIZE(attach_type_name)) + printf("%-15s", attach_type_name[attach_type]); + else + printf("type %-10u", attach_type); + printf(" %-15s %-15s\n", attach_flags_str, info.name); + } + + close(prog_fd); + return 0; +} + +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, query_flags, NULL, + NULL, &prog_cnt); + if (ret) + return -1; + + return prog_cnt; +} + +static int cgroup_has_attached_progs(int cgroup_fd) +{ + enum bpf_attach_type type; + bool no_prog = true; + + for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) { + int count = count_attached_bpf_progs(cgroup_fd, type); + + if (count < 0 && errno != EINVAL) + return -1; + + if (count > 0) { + no_prog = false; + break; + } + } + + return no_prog ? 0 : 1; +} +static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type, + int level) +{ + const char *attach_flags_str; + __u32 prog_ids[1024] = {0}; + __u32 prog_cnt, iter; + __u32 attach_flags; + char buf[32]; + int ret; + + prog_cnt = ARRAY_SIZE(prog_ids); + ret = bpf_prog_query(cgroup_fd, type, query_flags, &attach_flags, + prog_ids, &prog_cnt); + if (ret) + return ret; + + if (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 < prog_cnt; iter++) + show_bpf_prog(prog_ids[iter], type, + attach_flags_str, level); + + return 0; +} + +static int do_show(int argc, char **argv) +{ + enum bpf_attach_type type; + int has_attached_progs; + const char *path; + int cgroup_fd; + int ret = -1; + + 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(path, O_RDONLY); + if (cgroup_fd < 0) { + p_err("can't open cgroup %s", path); + goto exit; + } + + has_attached_progs = cgroup_has_attached_progs(cgroup_fd); + if (has_attached_progs < 0) { + p_err("can't query bpf programs attached to %s: %s", + path, strerror(errno)); + goto exit_cgroup; + } else if (!has_attached_progs) { + ret = 0; + goto exit_cgroup; + } + + if (json_output) + jsonw_start_array(json_wtr); + else + printf("%-8s %-15s %-15s %-15s\n", "ID", "AttachType", + "AttachFlags", "Name"); + + for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) { + /* + * Not all attach types may be supported, so it's expected, + * that some requests will fail. + * If we were able to get the show for at least one + * attach type, let's return 0. + */ + if (show_attached_bpf_progs(cgroup_fd, type, 0) == 0) + ret = 0; + } + + if (json_output) + jsonw_end_array(json_wtr); + +exit_cgroup: + close(cgroup_fd); +exit: + return ret; +} + +/* + * To distinguish nftw() errors and do_show_tree_fn() errors + * and avoid duplicating error messages, let's return -2 + * from do_show_tree_fn() in case of error. + */ +#define NFTW_ERR -1 +#define SHOW_TREE_FN_ERR -2 +static int do_show_tree_fn(const char *fpath, const struct stat *sb, + int typeflag, struct FTW *ftw) +{ + enum bpf_attach_type type; + int has_attached_progs; + int cgroup_fd; + + if (typeflag != FTW_D) + return 0; + + cgroup_fd = open(fpath, O_RDONLY); + if (cgroup_fd < 0) { + p_err("can't open cgroup %s: %s", fpath, strerror(errno)); + return SHOW_TREE_FN_ERR; + } + + has_attached_progs = cgroup_has_attached_progs(cgroup_fd); + if (has_attached_progs < 0) { + p_err("can't query bpf programs attached to %s: %s", + fpath, strerror(errno)); + close(cgroup_fd); + return SHOW_TREE_FN_ERR; + } else if (!has_attached_progs) { + close(cgroup_fd); + return 0; + } + + if (json_output) { + jsonw_start_object(json_wtr); + jsonw_string_field(json_wtr, "cgroup", fpath); + jsonw_name(json_wtr, "programs"); + jsonw_start_array(json_wtr); + } else { + printf("%s\n", fpath); + } + + for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) + show_attached_bpf_progs(cgroup_fd, type, ftw->level); + + if (errno == EINVAL) + /* Last attach type does not support query. + * Do not report an error for this, especially because batch + * mode would stop processing commands. + */ + errno = 0; + + if (json_output) { + jsonw_end_array(json_wtr); + jsonw_end_object(json_wtr); + } + + close(cgroup_fd); + + return 0; +} + +static char *find_cgroup_root(void) +{ + struct mntent *mnt; + FILE *f; + + f = fopen("/proc/mounts", "r"); + if (f == NULL) + return NULL; + + while ((mnt = getmntent(f))) { + if (strcmp(mnt->mnt_type, "cgroup2") == 0) { + fclose(f); + return strdup(mnt->mnt_dir); + } + } + + fclose(f); + return NULL; +} + +static int do_show_tree(int argc, char **argv) +{ + char *cgroup_root, *cgroup_alloced = NULL; + int ret; + + query_flags = 0; + + if (!argc) { + cgroup_alloced = find_cgroup_root(); + if (!cgroup_alloced) { + p_err("cgroup v2 isn't mounted"); + 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 + printf("%s\n" + "%-8s %-15s %-15s %-15s\n", + "CgroupPath", + "ID", "AttachType", "AttachFlags", "Name"); + + switch (nftw(cgroup_root, do_show_tree_fn, 1024, FTW_MOUNT)) { + case NFTW_ERR: + p_err("can't iterate over %s: %s", cgroup_root, + strerror(errno)); + ret = -1; + break; + case SHOW_TREE_FN_ERR: + ret = -1; + break; + default: + ret = 0; + } + + if (json_output) + jsonw_end_array(json_wtr); + + free(cgroup_alloced); + + return ret; +} + +static int do_attach(int argc, char **argv) +{ + enum bpf_attach_type attach_type; + int cgroup_fd, prog_fd; + int attach_flags = 0; + int ret = -1; + int i; + + if (argc < 4) { + p_err("too few parameters for cgroup attach"); + goto exit; + } + + cgroup_fd = open(argv[0], O_RDONLY); + if (cgroup_fd < 0) { + p_err("can't open cgroup %s", argv[0]); + goto exit; + } + + attach_type = parse_attach_type(argv[1]); + if (attach_type == __MAX_BPF_ATTACH_TYPE) { + p_err("invalid attach type"); + goto exit_cgroup; + } + + argc -= 2; + argv = &argv[2]; + prog_fd = prog_parse_fd(&argc, &argv); + if (prog_fd < 0) + goto exit_cgroup; + + for (i = 0; i < argc; i++) { + if (is_prefix(argv[i], "multi")) { + attach_flags |= BPF_F_ALLOW_MULTI; + } else if (is_prefix(argv[i], "override")) { + attach_flags |= BPF_F_ALLOW_OVERRIDE; + } else { + p_err("unknown option: %s", argv[i]); + goto exit_cgroup; + } + } + + if (bpf_prog_attach(prog_fd, cgroup_fd, attach_type, attach_flags)) { + p_err("failed to attach program"); + goto exit_prog; + } + + if (json_output) + jsonw_null(json_wtr); + + ret = 0; + +exit_prog: + close(prog_fd); +exit_cgroup: + close(cgroup_fd); +exit: + return ret; +} + +static int do_detach(int argc, char **argv) +{ + enum bpf_attach_type attach_type; + int prog_fd, cgroup_fd; + int ret = -1; + + if (argc < 4) { + p_err("too few parameters for cgroup detach"); + goto exit; + } + + cgroup_fd = open(argv[0], O_RDONLY); + if (cgroup_fd < 0) { + p_err("can't open cgroup %s", argv[0]); + goto exit; + } + + attach_type = parse_attach_type(argv[1]); + if (attach_type == __MAX_BPF_ATTACH_TYPE) { + p_err("invalid attach type"); + goto exit_cgroup; + } + + argc -= 2; + argv = &argv[2]; + prog_fd = prog_parse_fd(&argc, &argv); + if (prog_fd < 0) + goto exit_cgroup; + + if (bpf_prog_detach2(prog_fd, cgroup_fd, attach_type)) { + p_err("failed to detach program"); + goto exit_prog; + } + + if (json_output) + jsonw_null(json_wtr); + + ret = 0; + +exit_prog: + close(prog_fd); +exit_cgroup: + close(cgroup_fd); +exit: + return ret; +} + +static int do_help(int argc, char **argv) +{ + if (json_output) { + jsonw_null(json_wtr); + return 0; + } + + fprintf(stderr, + "Usage: %1$s %2$s { show | list } CGROUP [**effective**]\n" + " %1$s %2$s tree [CGROUP_ROOT] [**effective**]\n" + " %1$s %2$s attach CGROUP ATTACH_TYPE PROG [ATTACH_FLAGS]\n" + " %1$s %2$s detach CGROUP ATTACH_TYPE PROG\n" + " %1$s %2$s help\n" + "\n" + HELP_SPEC_ATTACH_TYPES "\n" + " " HELP_SPEC_ATTACH_FLAGS "\n" + " " HELP_SPEC_PROGRAM "\n" + " " HELP_SPEC_OPTIONS "\n" + "", + bin_name, argv[-2]); + + return 0; +} + +static const struct cmd cmds[] = { + { "show", do_show }, + { "list", do_show }, + { "tree", do_show_tree }, + { "attach", do_attach }, + { "detach", do_detach }, + { "help", do_help }, + { 0 } +}; + +int do_cgroup(int argc, char **argv) +{ + return cmd_select(cmds, argc, argv, do_help); +} |