diff options
Diffstat (limited to 'tools/testing/selftests/bpf/cgroup_helpers.c')
| -rw-r--r-- | tools/testing/selftests/bpf/cgroup_helpers.c | 132 |
1 files changed, 115 insertions, 17 deletions
diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index 5b1da2a32ea7..19be9c63d5e8 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -45,9 +45,12 @@ #define format_parent_cgroup_path(buf, path) \ format_cgroup_path_pid(buf, path, getppid()) -#define format_classid_path(buf) \ - snprintf(buf, sizeof(buf), "%s%s", NETCLS_MOUNT_PATH, \ - CGROUP_WORK_DIR) +#define format_classid_path_pid(buf, pid) \ + snprintf(buf, sizeof(buf), "%s%s%d", NETCLS_MOUNT_PATH, \ + CGROUP_WORK_DIR, pid) + +#define format_classid_path(buf) \ + format_classid_path_pid(buf, getpid()) static __thread bool cgroup_workdir_mounted; @@ -419,26 +422,23 @@ int create_and_get_cgroup(const char *relative_path) } /** - * get_cgroup_id() - Get cgroup id for a particular cgroup path - * @relative_path: The cgroup path, relative to the workdir, to join + * get_cgroup_id_from_path - Get cgroup id for a particular cgroup path + * @cgroup_workdir: The absolute cgroup path * * On success, it returns the cgroup id. On failure it returns 0, * which is an invalid cgroup id. * If there is a failure, it prints the error to stderr. */ -unsigned long long get_cgroup_id(const char *relative_path) +unsigned long long get_cgroup_id_from_path(const char *cgroup_workdir) { int dirfd, err, flags, mount_id, fhsize; union { unsigned long long cgid; unsigned char raw_bytes[8]; } id; - char cgroup_workdir[PATH_MAX + 1]; struct file_handle *fhp, *fhp2; unsigned long long ret = 0; - format_cgroup_path(cgroup_workdir, relative_path); - dirfd = AT_FDCWD; flags = 0; fhsize = sizeof(*fhp); @@ -474,6 +474,14 @@ free_mem: return ret; } +unsigned long long get_cgroup_id(const char *relative_path) +{ + char cgroup_workdir[PATH_MAX + 1]; + + format_cgroup_path(cgroup_workdir, relative_path); + return get_cgroup_id_from_path(cgroup_workdir); +} + int cgroup_setup_and_join(const char *path) { int cg_fd; @@ -523,10 +531,20 @@ int setup_classid_environment(void) return 1; } - if (mount("net_cls", NETCLS_MOUNT_PATH, "cgroup", 0, "net_cls") && - errno != EBUSY) { - log_err("mount cgroup net_cls"); - return 1; + if (mount("net_cls", NETCLS_MOUNT_PATH, "cgroup", 0, "net_cls")) { + if (errno != EBUSY) { + log_err("mount cgroup net_cls"); + return 1; + } + + if (rmdir(NETCLS_MOUNT_PATH)) { + log_err("rmdir cgroup net_cls"); + return 1; + } + if (umount(CGROUP_MOUNT_DFLT)) { + log_err("umount cgroup base"); + return 1; + } } cleanup_classid_environment(); @@ -541,15 +559,16 @@ int setup_classid_environment(void) /** * set_classid() - Set a cgroupv1 net_cls classid - * @id: the numeric classid * - * Writes the passed classid into the cgroup work dir's net_cls.classid + * Writes the classid into the cgroup work dir's net_cls.classid * file in order to later on trigger socket tagging. * + * We leverage the current pid as the classid, ensuring unique identification. + * * On success, it returns 0, otherwise on failure it returns 1. If there * is a failure, it prints the error to stderr. */ -int set_classid(unsigned int id) +int set_classid(void) { char cgroup_workdir[PATH_MAX - 42]; char cgroup_classid_path[PATH_MAX + 1]; @@ -565,7 +584,7 @@ int set_classid(unsigned int id) return 1; } - if (dprintf(fd, "%u\n", id) < 0) { + if (dprintf(fd, "%u\n", getpid()) < 0) { log_err("Setting cgroup classid"); rc = 1; } @@ -607,3 +626,82 @@ void cleanup_classid_environment(void) join_cgroup_from_top(NETCLS_MOUNT_PATH); nftw(cgroup_workdir, nftwfunc, WALK_FD_LIMIT, FTW_DEPTH | FTW_MOUNT); } + +/** + * get_classid_cgroup_id - Get the cgroup id of a net_cls cgroup + */ +unsigned long long get_classid_cgroup_id(void) +{ + char cgroup_workdir[PATH_MAX + 1]; + + format_classid_path(cgroup_workdir); + return get_cgroup_id_from_path(cgroup_workdir); +} + +/** + * get_cgroup1_hierarchy_id - Retrieves the ID of a cgroup1 hierarchy from the cgroup1 subsys name. + * @subsys_name: The cgroup1 subsys name, which can be retrieved from /proc/self/cgroup. It can be + * a named cgroup like "name=systemd", a controller name like "net_cls", or multi-contollers like + * "net_cls,net_prio". + */ +int get_cgroup1_hierarchy_id(const char *subsys_name) +{ + char *c, *c2, *c3, *c4; + bool found = false; + char line[1024]; + FILE *file; + int i, id; + + if (!subsys_name) + return -1; + + file = fopen("/proc/self/cgroup", "r"); + if (!file) { + log_err("fopen /proc/self/cgroup"); + return -1; + } + + while (fgets(line, 1024, file)) { + i = 0; + for (c = strtok_r(line, ":", &c2); c && i < 2; c = strtok_r(NULL, ":", &c2)) { + if (i == 0) { + id = strtol(c, NULL, 10); + } else if (i == 1) { + if (!strcmp(c, subsys_name)) { + found = true; + break; + } + + /* Multiple subsystems may share one single mount point */ + for (c3 = strtok_r(c, ",", &c4); c3; + c3 = strtok_r(NULL, ",", &c4)) { + if (!strcmp(c, subsys_name)) { + found = true; + break; + } + } + } + i++; + } + if (found) + break; + } + fclose(file); + return found ? id : -1; +} + +/** + * open_classid() - Open a cgroupv1 net_cls classid + * + * This function expects the cgroup work dir to be already created, as we + * open it here. + * + * On success, it returns the file descriptor. On failure it returns -1. + */ +int open_classid(void) +{ + char cgroup_workdir[PATH_MAX + 1]; + + format_classid_path(cgroup_workdir); + return open(cgroup_workdir, O_RDONLY); +} |