diff options
Diffstat (limited to 'tools/testing/selftests/bpf/cgroup_helpers.c')
| -rw-r--r-- | tools/testing/selftests/bpf/cgroup_helpers.c | 226 |
1 files changed, 202 insertions, 24 deletions
diff --git a/tools/testing/selftests/bpf/cgroup_helpers.c b/tools/testing/selftests/bpf/cgroup_helpers.c index 9e95b37a7dff..20cede4db3ce 100644 --- a/tools/testing/selftests/bpf/cgroup_helpers.c +++ b/tools/testing/selftests/bpf/cgroup_helpers.c @@ -4,6 +4,7 @@ #include <sys/mount.h> #include <sys/stat.h> #include <sys/types.h> +#include <sys/xattr.h> #include <linux/limits.h> #include <stdio.h> #include <stdlib.h> @@ -45,9 +46,16 @@ #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; + +static void __cleanup_cgroup_environment(void); static int __enable_controllers(const char *cgroup_path, const char *controllers) { @@ -195,6 +203,11 @@ int setup_cgroup_environment(void) format_cgroup_path(cgroup_workdir, ""); + if (mkdir(CGROUP_MOUNT_PATH, 0777) && errno != EEXIST) { + log_err("mkdir mount"); + return 1; + } + if (unshare(CLONE_NEWNS)) { log_err("unshare"); return 1; @@ -209,9 +222,10 @@ int setup_cgroup_environment(void) log_err("mount cgroup2"); return 1; } + cgroup_workdir_mounted = true; /* Cleanup existing failed runs, now that the environment is setup */ - cleanup_cgroup_environment(); + __cleanup_cgroup_environment(); if (mkdir(cgroup_workdir, 0777) && errno != EEXIST) { log_err("mkdir cgroup work dir"); @@ -278,6 +292,18 @@ int join_cgroup(const char *relative_path) } /** + * join_root_cgroup() - Join the root cgroup + * + * This function joins the root cgroup. + * + * On success, it returns 0, otherwise on failure it returns 1. + */ +int join_root_cgroup(void) +{ + return join_cgroup_from_top(CGROUP_MOUNT_PATH); +} + +/** * join_parent_cgroup() - Join a cgroup in the parent process workdir * @relative_path: The cgroup path, relative to parent process workdir, to join * @@ -294,10 +320,45 @@ int join_parent_cgroup(const char *relative_path) } /** + * set_cgroup_xattr() - Set xattr on a cgroup dir + * @relative_path: The cgroup path, relative to the workdir, to set xattr + * @name: xattr name + * @value: xattr value + * + * This function set xattr on cgroup dir. + * + * On success, it returns 0, otherwise on failure it returns -1. + */ +int set_cgroup_xattr(const char *relative_path, + const char *name, + const char *value) +{ + char cgroup_path[PATH_MAX + 1]; + + format_cgroup_path(cgroup_path, relative_path); + return setxattr(cgroup_path, name, value, strlen(value) + 1, 0); +} + +/** + * __cleanup_cgroup_environment() - Delete temporary cgroups + * + * This is a helper for cleanup_cgroup_environment() that is responsible for + * deletion of all temporary cgroups that have been created during the test. + */ +static void __cleanup_cgroup_environment(void) +{ + char cgroup_workdir[PATH_MAX + 1]; + + format_cgroup_path(cgroup_workdir, ""); + join_cgroup_from_top(CGROUP_MOUNT_PATH); + nftw(cgroup_workdir, nftwfunc, WALK_FD_LIMIT, FTW_DEPTH | FTW_MOUNT); +} + +/** * cleanup_cgroup_environment() - Cleanup Cgroup Testing Environment * * This is an idempotent function to delete all temporary cgroups that - * have been created during the test, including the cgroup testing work + * have been created during the test and unmount the cgroup testing work * directory. * * At call time, it moves the calling process to the root cgroup, and then @@ -308,11 +369,10 @@ int join_parent_cgroup(const char *relative_path) */ void cleanup_cgroup_environment(void) { - char cgroup_workdir[PATH_MAX + 1]; - - format_cgroup_path(cgroup_workdir, ""); - join_cgroup_from_top(CGROUP_MOUNT_PATH); - nftw(cgroup_workdir, nftwfunc, WALK_FD_LIMIT, FTW_DEPTH | FTW_MOUNT); + __cleanup_cgroup_environment(); + if (cgroup_workdir_mounted && umount(CGROUP_MOUNT_PATH)) + log_err("umount cgroup2"); + cgroup_workdir_mounted = false; } /** @@ -352,6 +412,26 @@ void remove_cgroup(const char *relative_path) log_err("rmdiring cgroup %s .. %s", relative_path, cgroup_path); } +/* + * remove_cgroup_pid() - Remove a cgroup setup by process identified by PID + * @relative_path: The cgroup path, relative to the workdir, to remove + * @pid: PID to be used to find cgroup_path + * + * This function expects a cgroup to already be created, relative to the cgroup + * work dir. It also expects the cgroup doesn't have any children or live + * processes and it removes the cgroup. + * + * On failure, it will print an error to stderr. + */ +void remove_cgroup_pid(const char *relative_path, int pid) +{ + char cgroup_path[PATH_MAX + 1]; + + format_cgroup_path_pid(cgroup_path, relative_path, pid); + if (rmdir(cgroup_path)) + log_err("rmdiring cgroup %s .. %s", relative_path, cgroup_path); +} + /** * create_and_get_cgroup() - Create a cgroup, relative to workdir, and get the FD * @relative_path: The cgroup path, relative to the workdir, to join @@ -383,26 +463,23 @@ 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) +static 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); @@ -438,6 +515,14 @@ 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; @@ -464,6 +549,9 @@ int cgroup_setup_and_join(const char *path) { /** * setup_classid_environment() - Setup the cgroupv1 net_cls environment * + * This function should only be called in a custom mount namespace, e.g. + * created by running setup_cgroup_environment. + * * After calling this function, cleanup_classid_environment should be called * once testing is complete. * @@ -487,10 +575,20 @@ 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(); @@ -505,15 +603,16 @@ 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]; @@ -529,7 +628,7 @@ 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; } @@ -571,3 +670,82 @@ 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-controllers 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); +} |