+++ /dev/null
-/*
- * lxc: linux Container library
- *
- * (C) Copyright IBM Corp. 2007, 2008
- *
- * Authors:
- * Daniel Lezcano <daniel.lezcano at free.fr>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-#include "config.h"
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <errno.h>
-#include <unistd.h>
-#include <string.h>
-#include <dirent.h>
-#include <fcntl.h>
-#include <grp.h>
-#include <ctype.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/param.h>
-#include <sys/inotify.h>
-#include <sys/mount.h>
-#include <netinet/in.h>
-#include <net/if.h>
-
-#include "error.h"
-#include "commands.h"
-#include "list.h"
-#include "conf.h"
-#include "utils.h"
-#include "log.h"
-#include "cgroup.h"
-#include "start.h"
-#include "state.h"
-#include "storage.h"
-
-#if IS_BIONIC
-#include <../include/lxcmntent.h>
-#else
-#include <mntent.h>
-#endif
-
-struct cgroup_hierarchy;
-struct cgroup_meta_data;
-struct cgroup_mount_point;
-
-/*
- * cgroup_meta_data: the metadata about the cgroup infrastructure on this
- * host
- */
-struct cgroup_meta_data {
- ptrdiff_t ref; /* simple refcount */
- struct cgroup_hierarchy **hierarchies;
- struct cgroup_mount_point **mount_points;
- int maximum_hierarchy;
-};
-
-/*
- * cgroup_hierarchy: describes a single cgroup hierarchy
- * (may have multiple mount points)
- */
-struct cgroup_hierarchy {
- int index;
- bool used; /* false if the hierarchy should be ignored by lxc */
- char **subsystems;
- struct cgroup_mount_point *rw_absolute_mount_point;
- struct cgroup_mount_point *ro_absolute_mount_point;
- struct cgroup_mount_point **all_mount_points;
- size_t all_mount_point_capacity;
-};
-
-/*
- * cgroup_mount_point: a mount point to where a hierarchy
- * is mounted to
- */
-struct cgroup_mount_point {
- struct cgroup_hierarchy *hierarchy;
- char *mount_point;
- char *mount_prefix;
- bool read_only;
- bool need_cpuset_init;
-};
-
-/*
- * cgroup_process_info: describes the membership of a
- * process to the different cgroup
- * hierarchies
- *
- * Note this is the per-process info tracked by the cgfs_ops.
- */
-struct cgroup_process_info {
- struct cgroup_process_info *next;
- struct cgroup_meta_data *meta_ref;
- struct cgroup_hierarchy *hierarchy;
- char *cgroup_path;
- char *cgroup_path_sub;
- char **created_paths;
- size_t created_paths_capacity;
- size_t created_paths_count;
- struct cgroup_mount_point *designated_mount_point;
-};
-
-struct cgfs_data {
- char *name;
- const char *cgroup_pattern;
- struct cgroup_meta_data *meta;
- struct cgroup_process_info *info;
-};
-
-lxc_log_define(lxc_cgfs, lxc);
-
-static struct cgroup_process_info *lxc_cgroup_process_info_getx(const char *proc_pid_cgroup_str, struct cgroup_meta_data *meta);
-static char **subsystems_from_mount_options(const char *mount_options, char **kernel_list);
-static void lxc_cgroup_mount_point_free(struct cgroup_mount_point *mp);
-static void lxc_cgroup_hierarchy_free(struct cgroup_hierarchy *h);
-static bool is_valid_cgroup(const char *name);
-static int create_cgroup(struct cgroup_mount_point *mp, const char *path);
-static int remove_cgroup(struct cgroup_mount_point *mp, const char *path, bool recurse,
- struct lxc_conf *conf);
-static char *cgroup_to_absolute_path(struct cgroup_mount_point *mp, const char *path, const char *suffix);
-static struct cgroup_process_info *find_info_for_subsystem(struct cgroup_process_info *info, const char *subsystem);
-static int do_cgroup_get(const char *cgroup_path, const char *sub_filename, char *value, size_t len);
-static int do_cgroup_set(const char *cgroup_path, const char *sub_filename, const char *value);
-static bool cgroup_devices_has_allow_or_deny(struct cgfs_data *d, char *v, bool for_allow);
-static int do_setup_cgroup_limits(struct cgfs_data *d, struct lxc_list *cgroup_settings, bool do_devices);
-static int cgroup_recursive_task_count(const char *cgroup_path);
-static int handle_cgroup_settings(struct cgroup_mount_point *mp, char *cgroup_path);
-static bool init_cpuset_if_needed(struct cgroup_mount_point *mp, const char *path);
-
-static struct cgroup_meta_data *lxc_cgroup_load_meta2(const char **subsystem_whitelist);
-static struct cgroup_meta_data *lxc_cgroup_get_meta(struct cgroup_meta_data *meta_data);
-static struct cgroup_meta_data *lxc_cgroup_put_meta(struct cgroup_meta_data *meta_data);
-
-/* free process membership information */
-static void lxc_cgroup_process_info_free(struct cgroup_process_info *info);
-static void lxc_cgroup_process_info_free_and_remove(struct cgroup_process_info *info,
- struct lxc_conf *conf);
-
-static struct cgroup_ops cgfs_ops;
-
-static int cgroup_rmdir(char *dirname)
-{
- struct dirent *direntp;
- int saved_errno = 0;
- DIR *dir;
- int ret, failed=0;
- char pathname[MAXPATHLEN];
-
- dir = opendir(dirname);
- if (!dir) {
- ERROR("Failed to open %s", dirname);
- return -1;
- }
-
- while ((direntp = readdir(dir))) {
- struct stat mystat;
- int rc;
-
- if (!direntp)
- break;
-
- if (!strcmp(direntp->d_name, ".") ||
- !strcmp(direntp->d_name, ".."))
- continue;
-
- rc = snprintf(pathname, MAXPATHLEN, "%s/%s", dirname, direntp->d_name);
- if (rc < 0 || rc >= MAXPATHLEN) {
- ERROR("pathname too long");
- failed=1;
- if (!saved_errno)
- saved_errno = -ENOMEM;
- continue;
- }
- ret = lstat(pathname, &mystat);
- if (ret) {
- SYSERROR("Failed to stat %s", pathname);
- failed=1;
- if (!saved_errno)
- saved_errno = errno;
- continue;
- }
- if (S_ISDIR(mystat.st_mode)) {
- if (cgroup_rmdir(pathname) < 0) {
- if (!saved_errno)
- saved_errno = errno;
- failed=1;
- }
- }
- }
-
- if (rmdir(dirname) < 0) {
- SYSERROR("Failed to delete %s", dirname);
- if (!saved_errno)
- saved_errno = errno;
- failed=1;
- }
-
- ret = closedir(dir);
- if (ret) {
- SYSERROR("Failed to close directory %s", dirname);
- if (!saved_errno)
- saved_errno = errno;
- failed=1;
- }
-
- errno = saved_errno;
- return failed ? -1 : 0;
-}
-
-static int rmdir_wrapper(void *data)
-{
- char *path = data;
-
- if (setresgid(0,0,0) < 0)
- SYSERROR("Failed to setgid to 0");
- if (setresuid(0,0,0) < 0)
- SYSERROR("Failed to setuid to 0");
- if (setgroups(0, NULL) < 0)
- SYSERROR("Failed to clear groups");
-
- return cgroup_rmdir(path);
-}
-
-static struct cgroup_meta_data *lxc_cgroup_load_meta()
-{
- const char *cgroup_use = NULL;
- char **cgroup_use_list = NULL;
- struct cgroup_meta_data *md = NULL;
- int saved_errno;
-
- errno = 0;
- cgroup_use = lxc_global_config_value("lxc.cgroup.use");
- if (!cgroup_use && errno != 0)
- return NULL;
- if (cgroup_use) {
- cgroup_use_list = lxc_string_split_and_trim(cgroup_use, ',');
- if (!cgroup_use_list)
- return NULL;
- }
-
- md = lxc_cgroup_load_meta2((const char **)cgroup_use_list);
- saved_errno = errno;
- lxc_free_array((void **)cgroup_use_list, free);
- errno = saved_errno;
- return md;
-}
-
-/* Step 1: determine all kernel subsystems */
-static bool find_cgroup_subsystems(char ***kernel_subsystems)
-{
- FILE *proc_cgroups;
- bool bret = false;
- char *line = NULL;
- size_t sz = 0;
- size_t kernel_subsystems_count = 0;
- size_t kernel_subsystems_capacity = 0;
- int r;
-
- proc_cgroups = fopen_cloexec("/proc/cgroups", "r");
- if (!proc_cgroups)
- return false;
-
- while (getline(&line, &sz, proc_cgroups) != -1) {
- char *tab1;
- char *tab2;
- int hierarchy_number;
-
- if (line[0] == '#')
- continue;
- if (!line[0])
- continue;
-
- tab1 = strchr(line, '\t');
- if (!tab1)
- continue;
- *tab1++ = '\0';
- tab2 = strchr(tab1, '\t');
- if (!tab2)
- continue;
- *tab2 = '\0';
-
- tab2 = NULL;
- hierarchy_number = strtoul(tab1, &tab2, 10);
- if (!tab2 || *tab2)
- continue;
- (void)hierarchy_number;
-
- r = lxc_grow_array((void ***)kernel_subsystems, &kernel_subsystems_capacity, kernel_subsystems_count + 1, 12);
- if (r < 0)
- goto out;
- (*kernel_subsystems)[kernel_subsystems_count] = strdup(line);
- if (!(*kernel_subsystems)[kernel_subsystems_count])
- goto out;
- kernel_subsystems_count++;
- }
- bret = true;
-
-out:
- fclose(proc_cgroups);
- free(line);
- return bret;
-}
-
-/* Step 2: determine all hierarchies (by reading /proc/self/cgroup),
- * since mount points don't specify hierarchy number and
- * /proc/cgroups does not contain named hierarchies
- */
-static bool find_cgroup_hierarchies(struct cgroup_meta_data *meta_data,
- bool all_kernel_subsystems, bool all_named_subsystems,
- const char **subsystem_whitelist)
-{
- FILE *proc_self_cgroup;
- char *line = NULL;
- size_t sz = 0;
- int r;
- bool bret = false;
- size_t hierarchy_capacity = 0;
-
- proc_self_cgroup = fopen_cloexec("/proc/self/cgroup", "r");
- /* if for some reason (because of setns() and pid namespace for example),
- * /proc/self is not valid, we try /proc/1/cgroup... */
- if (!proc_self_cgroup)
- proc_self_cgroup = fopen_cloexec("/proc/1/cgroup", "r");
- if (!proc_self_cgroup)
- return false;
-
- while (getline(&line, &sz, proc_self_cgroup) != -1) {
- /* file format: hierarchy:subsystems:group,
- * we only extract hierarchy and subsystems
- * here */
- char *colon1;
- char *colon2;
- int hierarchy_number;
- struct cgroup_hierarchy *h = NULL;
- char **p;
-
- if (!line[0])
- continue;
-
- colon1 = strchr(line, ':');
- if (!colon1)
- continue;
- *colon1++ = '\0';
- colon2 = strchr(colon1, ':');
- if (!colon2)
- continue;
- *colon2 = '\0';
-
- colon2 = NULL;
-
- /* With cgroupv2 /proc/self/cgroup can contain entries of the
- * form: 0::/
- * These entries need to be skipped.
- */
- if (!strcmp(colon1, ""))
- continue;
-
- hierarchy_number = strtoul(line, &colon2, 10);
- if (!colon2 || *colon2)
- continue;
-
- if (hierarchy_number > meta_data->maximum_hierarchy) {
- /* lxc_grow_array will never shrink, so even if we find a lower
- * hierarchy number here, the array will never be smaller
- */
- r = lxc_grow_array((void ***)&meta_data->hierarchies, &hierarchy_capacity, hierarchy_number + 1, 12);
- if (r < 0)
- goto out;
-
- meta_data->maximum_hierarchy = hierarchy_number;
- }
-
- /* this shouldn't happen, we had this already */
- if (meta_data->hierarchies[hierarchy_number])
- goto out;
-
- h = calloc(1, sizeof(struct cgroup_hierarchy));
- if (!h)
- goto out;
-
- meta_data->hierarchies[hierarchy_number] = h;
-
- h->index = hierarchy_number;
- h->subsystems = lxc_string_split_and_trim(colon1, ',');
- if (!h->subsystems)
- goto out;
- /* see if this hierarchy should be considered */
- if (!all_kernel_subsystems || !all_named_subsystems) {
- for (p = h->subsystems; *p; p++) {
- if (!strncmp(*p, "name=", 5)) {
- if (all_named_subsystems || (subsystem_whitelist && lxc_string_in_array(*p, subsystem_whitelist))) {
- h->used = true;
- break;
- }
- } else {
- if (all_kernel_subsystems || (subsystem_whitelist && lxc_string_in_array(*p, subsystem_whitelist))) {
- h->used = true;
- break;
- }
- }
- }
- } else {
- /* we want all hierarchy anyway */
- h->used = true;
- }
- }
- bret = true;
-
-out:
- fclose(proc_self_cgroup);
- free(line);
- return bret;
-}
-
-/* Step 3: determine all mount points of each hierarchy */
-static bool find_hierarchy_mountpts( struct cgroup_meta_data *meta_data, char **kernel_subsystems)
-{
- bool bret = false;
- FILE *proc_self_mountinfo;
- char *line = NULL;
- size_t sz = 0;
- char **tokens = NULL;
- size_t mount_point_count = 0;
- size_t mount_point_capacity = 0;
- size_t token_capacity = 0;
- int r;
- bool is_cgns = cgns_supported();
-
- proc_self_mountinfo = fopen_cloexec("/proc/self/mountinfo", "r");
- /* if for some reason (because of setns() and pid namespace for example),
- * /proc/self is not valid, we try /proc/1/cgroup... */
- if (!proc_self_mountinfo)
- proc_self_mountinfo = fopen_cloexec("/proc/1/mountinfo", "r");
- if (!proc_self_mountinfo)
- return false;
-
- while (getline(&line, &sz, proc_self_mountinfo) != -1) {
- char *token, *line_tok, *saveptr = NULL;
- size_t i, j, k;
- struct cgroup_mount_point *mount_point;
- struct cgroup_hierarchy *h;
- char **subsystems;
- bool is_lxcfs = false;
-
- if (line[0] && line[strlen(line) - 1] == '\n')
- line[strlen(line) - 1] = '\0';
-
- for (i = 0, line_tok = line; (token = strtok_r(line_tok, " ", &saveptr)); line_tok = NULL) {
- r = lxc_grow_array((void ***)&tokens, &token_capacity, i + 1, 64);
- if (r < 0)
- goto out;
- tokens[i++] = token;
- }
-
- /* layout of /proc/self/mountinfo:
- * 0: id
- * 1: parent id
- * 2: device major:minor
- * 3: mount prefix
- * 4: mount point
- * 5: per-mount options
- * [optional X]: additional data
- * X+7: "-"
- * X+8: type
- * X+9: source
- * X+10: per-superblock options
- */
- for (j = 6; j < i && tokens[j]; j++)
- if (!strcmp(tokens[j], "-"))
- break;
-
- /* could not find separator */
- if (j >= i || !tokens[j])
- continue;
- /* there should be exactly three fields after
- * the separator
- */
- if (i != j + 4)
- continue;
-
- /* not a cgroup filesystem */
- if (strcmp(tokens[j + 1], "cgroup") != 0) {
- if (strcmp(tokens[j + 1], "fuse.lxcfs") != 0)
- continue;
- if (strncmp(tokens[4], "/sys/fs/cgroup/", 15) != 0)
- continue;
- is_lxcfs = true;
- char *curtok = tokens[4] + 15;
- subsystems = subsystems_from_mount_options(curtok,
- kernel_subsystems);
- } else
- subsystems = subsystems_from_mount_options(tokens[j + 3],
- kernel_subsystems);
- if (!subsystems)
- goto out;
-
- h = NULL;
- for (k = 0; k <= meta_data->maximum_hierarchy; k++) {
- if (meta_data->hierarchies[k] &&
- meta_data->hierarchies[k]->subsystems[0] &&
- lxc_string_in_array(meta_data->hierarchies[k]->subsystems[0], (const char **)subsystems)) {
- /* TODO: we could also check if the lists really match completely,
- * just to have an additional sanity check */
- h = meta_data->hierarchies[k];
- break;
- }
- }
- lxc_free_array((void **)subsystems, free);
- if (!h)
- goto out;
-
- r = lxc_grow_array((void ***)&meta_data->mount_points, &mount_point_capacity, mount_point_count + 1, 12);
- if (r < 0)
- goto out;
-
- /* create mount point object */
- mount_point = calloc(1, sizeof(*mount_point));
- if (!mount_point)
- goto out;
-
- meta_data->mount_points[mount_point_count++] = mount_point;
-
- mount_point->hierarchy = h;
- if (is_lxcfs || is_cgns)
- mount_point->mount_prefix = strdup("/");
- else
- mount_point->mount_prefix = strdup(tokens[3]);
- mount_point->mount_point = strdup(tokens[4]);
- if (!mount_point->mount_point || !mount_point->mount_prefix)
- goto out;
- mount_point->read_only = !lxc_string_in_list("rw", tokens[5], ',');
-
- if (!strcmp(mount_point->mount_prefix, "/")) {
- if (mount_point->read_only) {
- if (!h->ro_absolute_mount_point)
- h->ro_absolute_mount_point = mount_point;
- } else {
- if (!h->rw_absolute_mount_point)
- h->rw_absolute_mount_point = mount_point;
- }
- }
-
- if (h)
- k = lxc_array_len((void **)h->all_mount_points);
- else
- k = 0;
- r = lxc_grow_array((void ***)&h->all_mount_points, &h->all_mount_point_capacity, k + 1, 4);
- if (r < 0)
- goto out;
- h->all_mount_points[k] = mount_point;
- }
- bret = true;
-
-out:
- fclose(proc_self_mountinfo);
- free(tokens);
- free(line);
- return bret;
-}
-
-static struct cgroup_meta_data *lxc_cgroup_load_meta2(const char **subsystem_whitelist)
-{
- bool all_kernel_subsystems = true;
- bool all_named_subsystems = false;
- struct cgroup_meta_data *meta_data = NULL;
- char **kernel_subsystems = NULL;
- int saved_errno = 0;
-
- /* if the subsystem whitelist is not specified, include all
- * hierarchies that contain kernel subsystems by default but
- * no hierarchies that only contain named subsystems
- *
- * if it is specified, the specifier @all will select all
- * hierarchies, @kernel will select all hierarchies with
- * kernel subsystems and @named will select all named
- * hierarchies
- */
- all_kernel_subsystems = subsystem_whitelist ?
- (lxc_string_in_array("@kernel", subsystem_whitelist) || lxc_string_in_array("@all", subsystem_whitelist)) :
- true;
- all_named_subsystems = subsystem_whitelist ?
- (lxc_string_in_array("@named", subsystem_whitelist) || lxc_string_in_array("@all", subsystem_whitelist)) :
- true;
-
- meta_data = calloc(1, sizeof(struct cgroup_meta_data));
- if (!meta_data)
- return NULL;
- meta_data->ref = 1;
-
- if (!find_cgroup_subsystems(&kernel_subsystems))
- goto out_error;
-
- if (!find_cgroup_hierarchies(meta_data, all_kernel_subsystems,
- all_named_subsystems, subsystem_whitelist))
- goto out_error;
-
- if (!find_hierarchy_mountpts(meta_data, kernel_subsystems))
- goto out_error;
-
- /* oops, we couldn't find anything */
- if (!meta_data->hierarchies || !meta_data->mount_points) {
- errno = EINVAL;
- goto out_error;
- }
-
- lxc_free_array((void **)kernel_subsystems, free);
- return meta_data;
-
-out_error:
- saved_errno = errno;
- lxc_free_array((void **)kernel_subsystems, free);
- lxc_cgroup_put_meta(meta_data);
- errno = saved_errno;
- return NULL;
-}
-
-static struct cgroup_meta_data *lxc_cgroup_get_meta(struct cgroup_meta_data *meta_data)
-{
- meta_data->ref++;
- return meta_data;
-}
-
-static struct cgroup_meta_data *lxc_cgroup_put_meta(struct cgroup_meta_data *meta_data)
-{
- size_t i;
- if (!meta_data)
- return NULL;
- if (--meta_data->ref > 0)
- return meta_data;
- lxc_free_array((void **)meta_data->mount_points, (lxc_free_fn)lxc_cgroup_mount_point_free);
- if (meta_data->hierarchies)
- for (i = 0; i <= meta_data->maximum_hierarchy; i++)
- if (meta_data->hierarchies[i])
- lxc_cgroup_hierarchy_free(meta_data->hierarchies[i]);
- free(meta_data->hierarchies);
- free(meta_data);
- return NULL;
-}
-
-static struct cgroup_hierarchy *lxc_cgroup_find_hierarchy(struct cgroup_meta_data *meta_data, const char *subsystem)
-{
- size_t i;
- for (i = 0; i <= meta_data->maximum_hierarchy; i++) {
- struct cgroup_hierarchy *h = meta_data->hierarchies[i];
- if (!h)
- continue;
- if (h && lxc_string_in_array(subsystem, (const char **)h->subsystems))
- return h;
- }
- return NULL;
-}
-
-static bool mountpoint_is_accessible(struct cgroup_mount_point *mp)
-{
- return mp && access(mp->mount_point, F_OK) == 0;
-}
-
-static struct cgroup_mount_point *lxc_cgroup_find_mount_point(struct cgroup_hierarchy *hierarchy, const char *group, bool should_be_writable)
-{
- struct cgroup_mount_point **mps;
- struct cgroup_mount_point *current_result = NULL;
- ssize_t quality = -1;
-
- /* trivial case */
- if (mountpoint_is_accessible(hierarchy->rw_absolute_mount_point))
- return hierarchy->rw_absolute_mount_point;
- if (!should_be_writable && mountpoint_is_accessible(hierarchy->ro_absolute_mount_point))
- return hierarchy->ro_absolute_mount_point;
-
- for (mps = hierarchy->all_mount_points; mps && *mps; mps++) {
- struct cgroup_mount_point *mp = *mps;
- size_t prefix_len = mp->mount_prefix ? strlen(mp->mount_prefix) : 0;
-
- if (prefix_len == 1 && mp->mount_prefix[0] == '/')
- prefix_len = 0;
-
- if (!mountpoint_is_accessible(mp))
- continue;
-
- if (should_be_writable && mp->read_only)
- continue;
-
- if (!prefix_len ||
- (strncmp(group, mp->mount_prefix, prefix_len) == 0 &&
- (group[prefix_len] == '\0' || group[prefix_len] == '/'))) {
- /* search for the best quality match, i.e. the match with the
- * shortest prefix where this group is still contained
- */
- if (quality == -1 || prefix_len < quality) {
- current_result = mp;
- quality = prefix_len;
- }
- }
- }
-
- if (!current_result)
- errno = ENOENT;
- return current_result;
-}
-
-static char *lxc_cgroup_find_abs_path(const char *subsystem, const char *group, bool should_be_writable, const char *suffix)
-{
- struct cgroup_meta_data *meta_data;
- struct cgroup_hierarchy *h;
- struct cgroup_mount_point *mp;
- char *result;
- int saved_errno;
-
- meta_data = lxc_cgroup_load_meta();
- if (!meta_data)
- return NULL;
-
- h = lxc_cgroup_find_hierarchy(meta_data, subsystem);
- if (!h)
- goto out_error;
-
- mp = lxc_cgroup_find_mount_point(h, group, should_be_writable);
- if (!mp)
- goto out_error;
-
- result = cgroup_to_absolute_path(mp, group, suffix);
- if (!result)
- goto out_error;
-
- lxc_cgroup_put_meta(meta_data);
- return result;
-
-out_error:
- saved_errno = errno;
- lxc_cgroup_put_meta(meta_data);
- errno = saved_errno;
- return NULL;
-}
-
-static struct cgroup_process_info *lxc_cgroup_process_info_get(pid_t pid, struct cgroup_meta_data *meta)
-{
- char pid_buf[32];
- snprintf(pid_buf, 32, "/proc/%lu/cgroup", (unsigned long)pid);
- return lxc_cgroup_process_info_getx(pid_buf, meta);
-}
-
-static struct cgroup_process_info *lxc_cgroup_process_info_get_init(struct cgroup_meta_data *meta)
-{
- return lxc_cgroup_process_info_get(1, meta);
-}
-
-static struct cgroup_process_info *lxc_cgroup_process_info_get_self(struct cgroup_meta_data *meta)
-{
- struct cgroup_process_info *i;
- i = lxc_cgroup_process_info_getx("/proc/self/cgroup", meta);
- if (!i)
- i = lxc_cgroup_process_info_get(lxc_raw_getpid(), meta);
- return i;
-}
-
-/*
- * If a controller has ns cgroup mounted, then in that cgroup the handler->pid
- * is already in a new cgroup named after the pid. 'mnt' is passed in as
- * the full current cgroup. Say that is /sys/fs/cgroup/lxc/2975 and the container
- * name is c1. . We want to rename the cgroup directory to /sys/fs/cgroup/lxc/c1,
- * and return the string /sys/fs/cgroup/lxc/c1.
- */
-static char *cgroup_rename_nsgroup(const char *mountpath, const char *oldname, pid_t pid, const char *name)
-{
- char *dir, *fulloldpath;
- char *newname, *fullnewpath;
- int len, newlen, ret;
-
- /*
- * if cgroup is mounted at /cgroup and task is in cgroup /ab/, pid 2375 and
- * name is c1,
- * dir: /ab
- * fulloldpath = /cgroup/ab/2375
- * fullnewpath = /cgroup/ab/c1
- * newname = /ab/c1
- */
- dir = alloca(strlen(oldname) + 1);
- strcpy(dir, oldname);
-
- len = strlen(oldname) + strlen(mountpath) + 22;
- fulloldpath = alloca(len);
- ret = snprintf(fulloldpath, len, "%s/%s/%lu", mountpath, oldname, (unsigned long)pid);
- if (ret < 0 || ret >= len)
- return NULL;
-
- len = strlen(dir) + strlen(name) + 2;
- newname = malloc(len);
- if (!newname) {
- SYSERROR("Out of memory");
- return NULL;
- }
- ret = snprintf(newname, len, "%s/%s", dir, name);
- if (ret < 0 || ret >= len) {
- free(newname);
- return NULL;
- }
-
- newlen = strlen(mountpath) + len + 2;
- fullnewpath = alloca(newlen);
- ret = snprintf(fullnewpath, newlen, "%s/%s", mountpath, newname);
- if (ret < 0 || ret >= newlen) {
- free(newname);
- return NULL;
- }
-
- if (access(fullnewpath, F_OK) == 0) {
- if (rmdir(fullnewpath) != 0) {
- SYSERROR("container cgroup %s already exists.", fullnewpath);
- free(newname);
- return NULL;
- }
- }
- if (rename(fulloldpath, fullnewpath)) {
- SYSERROR("failed to rename cgroup %s->%s", fulloldpath, fullnewpath);
- free(newname);
- return NULL;
- }
-
- DEBUG("'%s' renamed to '%s'", oldname, newname);
-
- return newname;
-}
-
-static bool is_crucial_hierarchy(struct cgroup_hierarchy *h)
-{
- char **p;
-
- for (p = h->subsystems; *p; p++) {
- if (is_crucial_cgroup_subsystem(*p))
- return true;
- }
- return false;
-}
-
-/* create a new cgroup */
-static struct cgroup_process_info *lxc_cgroupfs_create(const char *name, const char *path_pattern, struct cgroup_meta_data *meta_data, const char *sub_pattern)
-{
- char **cgroup_path_components = NULL;
- char **p = NULL;
- char *path_so_far = NULL;
- char **new_cgroup_paths = NULL;
- char **new_cgroup_paths_sub = NULL;
- struct cgroup_mount_point *mp;
- struct cgroup_hierarchy *h;
- struct cgroup_process_info *base_info = NULL;
- struct cgroup_process_info *info_ptr;
- int saved_errno;
- int r;
- unsigned suffix = 0;
- bool had_sub_pattern = false;
- size_t i;
-
- if (!is_valid_cgroup(name)) {
- ERROR("Invalid cgroup name: '%s'", name);
- errno = EINVAL;
- return NULL;
- }
-
- if (!strstr(path_pattern, "%n")) {
- ERROR("Invalid cgroup path pattern: '%s'; contains no %%n for specifying container name", path_pattern);
- errno = EINVAL;
- return NULL;
- }
-
- /* we will modify the result of this operation directly,
- * so we don't have to copy the data structure
- */
- base_info = (path_pattern[0] == '/') ?
- lxc_cgroup_process_info_get_init(meta_data) :
- lxc_cgroup_process_info_get_self(meta_data);
- if (!base_info)
- return NULL;
-
- new_cgroup_paths = calloc(meta_data->maximum_hierarchy + 1, sizeof(char *));
- if (!new_cgroup_paths)
- goto out_initial_error;
-
- new_cgroup_paths_sub = calloc(meta_data->maximum_hierarchy + 1, sizeof(char *));
- if (!new_cgroup_paths_sub)
- goto out_initial_error;
-
- /* find mount points we can use */
- for (info_ptr = base_info; info_ptr; info_ptr = info_ptr->next) {
- h = info_ptr->hierarchy;
- if (!h)
- continue;
- mp = lxc_cgroup_find_mount_point(h, info_ptr->cgroup_path, true);
- if (!mp) {
- ERROR("Could not find writable mount point for cgroup hierarchy %d while trying to create cgroup.", h->index);
- goto out_initial_error;
- }
- info_ptr->designated_mount_point = mp;
-
- if (lxc_string_in_array("ns", (const char **)h->subsystems))
- continue;
- if (handle_cgroup_settings(mp, info_ptr->cgroup_path) < 0) {
- ERROR("Could not set clone_children to 1 for cpuset hierarchy in parent cgroup.");
- goto out_initial_error;
- }
- }
-
- /* normalize the path */
- cgroup_path_components = lxc_normalize_path(path_pattern);
- if (!cgroup_path_components)
- goto out_initial_error;
-
- /* go through the path components to see if we can create them */
- for (p = cgroup_path_components; *p || (sub_pattern && !had_sub_pattern); p++) {
- /* we only want to create the same component with -1, -2, etc.
- * if the component contains the container name itself, otherwise
- * it's not an error if it already exists
- */
- char *p_eff = *p ? *p : (char *)sub_pattern;
- bool contains_name = strstr(p_eff, "%n");
- char *current_component = NULL;
- char *current_subpath = NULL;
- char *current_entire_path = NULL;
- char *parts[3];
- size_t j = 0;
- i = 0;
-
- /* if we are processing the subpattern, we want to make sure
- * loop is ended the next time around
- */
- if (!*p) {
- had_sub_pattern = true;
- p--;
- }
-
- goto find_name_on_this_level;
-
- cleanup_name_on_this_level:
- /* This is reached if we found a name clash.
- * In that case, remove the cgroup from all previous hierarchies
- */
- for (j = 0, info_ptr = base_info; j < i && info_ptr; info_ptr = info_ptr->next, j++) {
- if (info_ptr->created_paths_count < 1)
- continue;
- r = remove_cgroup(info_ptr->designated_mount_point, info_ptr->created_paths[info_ptr->created_paths_count - 1], false, NULL);
- if (r < 0)
- WARN("could not clean up cgroup we created when trying to create container");
- free(info_ptr->created_paths[info_ptr->created_paths_count - 1]);
- info_ptr->created_paths[--info_ptr->created_paths_count] = NULL;
- }
- if (current_component != current_subpath)
- free(current_subpath);
- if (current_component != p_eff)
- free(current_component);
- current_component = current_subpath = NULL;
- /* try again with another suffix */
- ++suffix;
-
- find_name_on_this_level:
- /* determine name of the path component we should create */
- if (contains_name && suffix > 0) {
- char *buf = calloc(strlen(name) + 32, 1);
- if (!buf)
- goto out_initial_error;
- snprintf(buf, strlen(name) + 32, "%s-%u", name, suffix);
- current_component = lxc_string_replace("%n", buf, p_eff);
- free(buf);
- } else {
- current_component = contains_name ? lxc_string_replace("%n", name, p_eff) : p_eff;
- }
- parts[0] = path_so_far;
- parts[1] = current_component;
- parts[2] = NULL;
- current_subpath = path_so_far ? lxc_string_join("/", (const char **)parts, false) : current_component;
-
- /* Now go through each hierarchy and try to create the
- * corresponding cgroup
- */
- for (i = 0, info_ptr = base_info; info_ptr; info_ptr = info_ptr->next, i++) {
- char *parts2[3];
-
- if (!info_ptr->hierarchy)
- continue;
-
- if (lxc_string_in_array("ns", (const char **)info_ptr->hierarchy->subsystems))
- continue;
- current_entire_path = NULL;
-
- parts2[0] = !strcmp(info_ptr->cgroup_path, "/") ? "" : info_ptr->cgroup_path;
- parts2[1] = current_subpath;
- parts2[2] = NULL;
- current_entire_path = lxc_string_join("/", (const char **)parts2, false);
-
- if (!*p) {
- /* we are processing the subpath, so only update that one */
- free(new_cgroup_paths_sub[i]);
- new_cgroup_paths_sub[i] = strdup(current_entire_path);
- if (!new_cgroup_paths_sub[i])
- goto cleanup_from_error;
- } else {
- /* remember which path was used on this controller */
- free(new_cgroup_paths[i]);
- new_cgroup_paths[i] = strdup(current_entire_path);
- if (!new_cgroup_paths[i])
- goto cleanup_from_error;
- }
-
- r = create_cgroup(info_ptr->designated_mount_point, current_entire_path);
- if (r < 0 && errno == EEXIST && contains_name) {
- /* name clash => try new name with new suffix */
- free(current_entire_path);
- current_entire_path = NULL;
- goto cleanup_name_on_this_level;
- } else if (r < 0 && errno != EEXIST) {
- if (is_crucial_hierarchy(info_ptr->hierarchy)) {
- SYSERROR("Could not create cgroup '%s' in '%s'.", current_entire_path, info_ptr->designated_mount_point->mount_point);
- goto cleanup_from_error;
- }
- goto skip;
- } else if (r == 0) {
- /* successfully created */
- r = lxc_grow_array((void ***)&info_ptr->created_paths, &info_ptr->created_paths_capacity, info_ptr->created_paths_count + 1, 8);
- if (r < 0)
- goto cleanup_from_error;
- if (!init_cpuset_if_needed(info_ptr->designated_mount_point, current_entire_path)) {
- ERROR("Failed to initialize cpuset for '%s' in '%s'.", current_entire_path, info_ptr->designated_mount_point->mount_point);
- goto cleanup_from_error;
- }
- info_ptr->created_paths[info_ptr->created_paths_count++] = current_entire_path;
- } else {
- /* if we didn't create the cgroup, then we have to make sure that
- * further cgroups will be created properly
- */
- if (handle_cgroup_settings(info_ptr->designated_mount_point, info_ptr->cgroup_path) < 0) {
- ERROR("Could not set clone_children to 1 for cpuset hierarchy in pre-existing cgroup.");
- goto cleanup_from_error;
- }
- if (!init_cpuset_if_needed(info_ptr->designated_mount_point, info_ptr->cgroup_path)) {
- ERROR("Failed to initialize cpuset in pre-existing '%s'.", info_ptr->cgroup_path);
- goto cleanup_from_error;
- }
-
-skip:
- /* already existed but path component of pattern didn't contain '%n',
- * so this is not an error; but then we don't need current_entire_path
- * anymore...
- */
- free(current_entire_path);
- current_entire_path = NULL;
- }
- }
-
- /* save path so far */
- free(path_so_far);
- path_so_far = strdup(current_subpath);
- if (!path_so_far)
- goto cleanup_from_error;
-
- /* cleanup */
- if (current_component != current_subpath)
- free(current_subpath);
- if (current_component != p_eff)
- free(current_component);
- current_component = current_subpath = NULL;
- continue;
-
- cleanup_from_error:
- /* called if an error occurred in the loop, so we
- * do some additional cleanup here
- */
- saved_errno = errno;
- if (current_component != current_subpath)
- free(current_subpath);
- if (current_component != p_eff)
- free(current_component);
- free(current_entire_path);
- errno = saved_errno;
- goto out_initial_error;
- }
-
- /* we're done, now update the paths */
- for (i = 0, info_ptr = base_info; info_ptr; info_ptr = info_ptr->next, i++) {
- if (!info_ptr->hierarchy)
- continue;
- /* ignore legacy 'ns' subsystem here, lxc_cgroup_create_legacy
- * will take care of it
- * Since we do a continue in above loop, new_cgroup_paths[i] is
- * unset anyway, as is new_cgroup_paths_sub[i]
- */
- if (lxc_string_in_array("ns", (const char **)info_ptr->hierarchy->subsystems))
- continue;
- free(info_ptr->cgroup_path);
- info_ptr->cgroup_path = new_cgroup_paths[i];
- info_ptr->cgroup_path_sub = new_cgroup_paths_sub[i];
- }
- /* don't use lxc_free_array since we used the array members
- * to store them in our result...
- */
- free(new_cgroup_paths);
- free(new_cgroup_paths_sub);
- free(path_so_far);
- lxc_free_array((void **)cgroup_path_components, free);
- return base_info;
-
-out_initial_error:
- saved_errno = errno;
- free(path_so_far);
- lxc_cgroup_process_info_free_and_remove(base_info, NULL);
- lxc_free_array((void **)new_cgroup_paths, free);
- lxc_free_array((void **)new_cgroup_paths_sub, free);
- lxc_free_array((void **)cgroup_path_components, free);
- errno = saved_errno;
- return NULL;
-}
-
-static int lxc_cgroup_create_legacy(struct cgroup_process_info *base_info, const char *name, pid_t pid)
-{
- struct cgroup_process_info *info_ptr;
- int r;
-
- for (info_ptr = base_info; info_ptr; info_ptr = info_ptr->next) {
- if (!info_ptr->hierarchy)
- continue;
-
- if (!lxc_string_in_array("ns", (const char **)info_ptr->hierarchy->subsystems))
- continue;
- /*
- * For any path which has ns cgroup mounted, handler->pid is already
- * moved into a container called '%d % (handler->pid)'. Rename it to
- * the cgroup name and record that.
- */
- char *tmp = cgroup_rename_nsgroup((const char *)info_ptr->designated_mount_point->mount_point,
- info_ptr->cgroup_path, pid, name);
- if (!tmp)
- return -1;
- free(info_ptr->cgroup_path);
- info_ptr->cgroup_path = tmp;
- r = lxc_grow_array((void ***)&info_ptr->created_paths, &info_ptr->created_paths_capacity, info_ptr->created_paths_count + 1, 8);
- if (r < 0)
- return -1;
- tmp = strdup(tmp);
- if (!tmp)
- return -1;
- info_ptr->created_paths[info_ptr->created_paths_count++] = tmp;
- }
- return 0;
-}
-
-/* get the cgroup membership of a given container */
-static struct cgroup_process_info *lxc_cgroup_get_container_info(const char *name, const char *lxcpath, struct cgroup_meta_data *meta_data)
-{
- struct cgroup_process_info *result = NULL;
- int saved_errno = 0;
- size_t i;
- struct cgroup_process_info **cptr = &result;
- struct cgroup_process_info *entry = NULL;
- char *path = NULL;
-
- for (i = 0; i <= meta_data->maximum_hierarchy; i++) {
- struct cgroup_hierarchy *h = meta_data->hierarchies[i];
- if (!h || !h->used)
- continue;
-
- /* use the command interface to look for the cgroup */
- path = lxc_cmd_get_cgroup_path(name, lxcpath, h->subsystems[0]);
- if (!path) {
- h->used = false;
- continue;
- }
-
- entry = calloc(1, sizeof(struct cgroup_process_info));
- if (!entry)
- goto out_error;
- entry->meta_ref = lxc_cgroup_get_meta(meta_data);
- entry->hierarchy = h;
- entry->cgroup_path = path;
- path = NULL;
-
- /* it is not an error if we don't find anything here,
- * it is up to the caller to decide what to do in that
- * case */
- entry->designated_mount_point = lxc_cgroup_find_mount_point(h, entry->cgroup_path, true);
-
- *cptr = entry;
- cptr = &entry->next;
- entry = NULL;
- }
-
- return result;
-out_error:
- saved_errno = errno;
- free(path);
- lxc_cgroup_process_info_free(result);
- lxc_cgroup_process_info_free(entry);
- errno = saved_errno;
- return NULL;
-}
-
-/* move a processs to the cgroups specified by the membership */
-static int lxc_cgroupfs_enter(struct cgroup_process_info *info, pid_t pid, bool enter_sub)
-{
- char pid_buf[32];
- char *cgroup_tasks_fn;
- int r;
- struct cgroup_process_info *info_ptr;
-
- snprintf(pid_buf, 32, "%lu", (unsigned long)pid);
- for (info_ptr = info; info_ptr; info_ptr = info_ptr->next) {
- if (!info_ptr->hierarchy)
- continue;
-
- char *cgroup_path = (enter_sub && info_ptr->cgroup_path_sub) ?
- info_ptr->cgroup_path_sub :
- info_ptr->cgroup_path;
-
- if (!info_ptr->designated_mount_point) {
- info_ptr->designated_mount_point = lxc_cgroup_find_mount_point(info_ptr->hierarchy, cgroup_path, true);
- if (!info_ptr->designated_mount_point) {
- SYSERROR("Could not add pid %lu to cgroup %s: internal error (couldn't find any writable mountpoint to cgroup filesystem)", (unsigned long)pid, cgroup_path);
- return -1;
- }
- }
-
- cgroup_tasks_fn = cgroup_to_absolute_path(info_ptr->designated_mount_point, cgroup_path, "/tasks");
- if (!cgroup_tasks_fn) {
- SYSERROR("Could not add pid %lu to cgroup %s: internal error", (unsigned long)pid, cgroup_path);
- return -1;
- }
-
- r = lxc_write_to_file(cgroup_tasks_fn, pid_buf, strlen(pid_buf), false);
- free(cgroup_tasks_fn);
- if (r < 0 && is_crucial_hierarchy(info_ptr->hierarchy)) {
- SYSERROR("Could not add pid %lu to cgroup %s: internal error", (unsigned long)pid, cgroup_path);
- return -1;
- }
- }
-
- return 0;
-}
-
-/* free process membership information */
-void lxc_cgroup_process_info_free(struct cgroup_process_info *info)
-{
- struct cgroup_process_info *next;
- if (!info)
- return;
- next = info->next;
- lxc_cgroup_put_meta(info->meta_ref);
- free(info->cgroup_path);
- free(info->cgroup_path_sub);
- lxc_free_array((void **)info->created_paths, free);
- free(info);
- lxc_cgroup_process_info_free(next);
-}
-
-/* free process membership information and remove cgroups that were created */
-void lxc_cgroup_process_info_free_and_remove(struct cgroup_process_info *info, struct lxc_conf *conf)
-{
- struct cgroup_process_info *next;
- char **pp;
- if (!info)
- return;
- next = info->next;
- {
- struct cgroup_mount_point *mp = info->designated_mount_point;
- if (!mp)
- mp = lxc_cgroup_find_mount_point(info->hierarchy, info->cgroup_path, true);
- if (mp)
- /* ignore return value here, perhaps we created the
- * '/lxc' cgroup in this container but another container
- * is still running (for example)
- */
- (void)remove_cgroup(mp, info->cgroup_path, true, conf);
- }
- for (pp = info->created_paths; pp && *pp; pp++);
- for ((void)(pp && --pp); info->created_paths && pp >= info->created_paths; --pp) {
- free(*pp);
- }
- free(info->created_paths);
- lxc_cgroup_put_meta(info->meta_ref);
- free(info->cgroup_path);
- free(info->cgroup_path_sub);
- free(info);
- lxc_cgroup_process_info_free_and_remove(next, conf);
-}
-
-static char *lxc_cgroup_get_hierarchy_path_data(const char *subsystem, struct cgfs_data *d)
-{
- struct cgroup_process_info *info = d->info;
- info = find_info_for_subsystem(info, subsystem);
- if (!info)
- return NULL;
- prune_init_scope(info->cgroup_path);
- return info->cgroup_path;
-}
-
-static char *lxc_cgroup_get_hierarchy_abs_path_data(const char *subsystem, struct cgfs_data *d)
-{
- struct cgroup_process_info *info = d->info;
- struct cgroup_mount_point *mp = NULL;
-
- info = find_info_for_subsystem(info, subsystem);
- if (!info)
- return NULL;
- if (info->designated_mount_point) {
- mp = info->designated_mount_point;
- } else {
- mp = lxc_cgroup_find_mount_point(info->hierarchy, info->cgroup_path, true);
- if (!mp)
- return NULL;
- }
- return cgroup_to_absolute_path(mp, info->cgroup_path, NULL);
-}
-
-static char *lxc_cgroup_get_hierarchy_abs_path(const char *subsystem, const char *name, const char *lxcpath)
-{
- struct cgroup_meta_data *meta;
- struct cgroup_process_info *base_info, *info;
- struct cgroup_mount_point *mp;
- char *result = NULL;
-
- meta = lxc_cgroup_load_meta();
- if (!meta)
- return NULL;
- base_info = lxc_cgroup_get_container_info(name, lxcpath, meta);
- if (!base_info)
- goto out1;
- info = find_info_for_subsystem(base_info, subsystem);
- if (!info)
- goto out2;
- if (info->designated_mount_point) {
- mp = info->designated_mount_point;
- } else {
- mp = lxc_cgroup_find_mount_point(info->hierarchy, info->cgroup_path, true);
- if (!mp)
- goto out3;
- }
- result = cgroup_to_absolute_path(mp, info->cgroup_path, NULL);
-out3:
-out2:
- lxc_cgroup_process_info_free(base_info);
-out1:
- lxc_cgroup_put_meta(meta);
- return result;
-}
-
-static int lxc_cgroup_set_data(const char *filename, const char *value, struct cgfs_data *d)
-{
- char *subsystem = NULL, *p, *path;
- int ret = -1;
-
- subsystem = alloca(strlen(filename) + 1);
- strcpy(subsystem, filename);
- if ((p = strchr(subsystem, '.')) != NULL)
- *p = '\0';
-
- errno = ENOENT;
- path = lxc_cgroup_get_hierarchy_abs_path_data(subsystem, d);
- if (path) {
- ret = do_cgroup_set(path, filename, value);
- int saved_errno = errno;
- free(path);
- errno = saved_errno;
- }
- return ret;
-}
-
-static int lxc_cgroupfs_set(const char *filename, const char *value, const char *name, const char *lxcpath)
-{
- char *subsystem = NULL, *p, *path;
- int ret = -1;
-
- subsystem = alloca(strlen(filename) + 1);
- strcpy(subsystem, filename);
- if ((p = strchr(subsystem, '.')) != NULL)
- *p = '\0';
-
- path = lxc_cgroup_get_hierarchy_abs_path(subsystem, name, lxcpath);
- if (path) {
- ret = do_cgroup_set(path, filename, value);
- free(path);
- }
- return ret;
-}
-
-static int lxc_cgroupfs_get(const char *filename, char *value, size_t len, const char *name, const char *lxcpath)
-{
- char *subsystem = NULL, *p, *path;
- int ret = -1;
-
- subsystem = alloca(strlen(filename) + 1);
- strcpy(subsystem, filename);
- if ((p = strchr(subsystem, '.')) != NULL)
- *p = '\0';
-
- path = lxc_cgroup_get_hierarchy_abs_path(subsystem, name, lxcpath);
- if (path) {
- ret = do_cgroup_get(path, filename, value, len);
- free(path);
- }
- return ret;
-}
-
-static bool cgroupfs_mount_cgroup(void *hdata, const char *root, int type)
-{
- size_t bufsz = strlen(root) + sizeof("/sys/fs/cgroup");
- char *path = NULL;
- char **parts = NULL;
- char *dirname = NULL;
- char *abs_path = NULL;
- char *abs_path2 = NULL;
- struct cgfs_data *cgfs_d;
- struct cgroup_process_info *info, *base_info;
- int r, saved_errno = 0;
- struct lxc_handler *handler = hdata;
-
- if (cgns_supported())
- return true;
-
- cgfs_d = handler->cgroup_data;
- if (!cgfs_d)
- return false;
- base_info = cgfs_d->info;
-
- /* If we get passed the _NOSPEC types, we default to _MIXED, since we don't
- * have access to the lxc_conf object at this point. It really should be up
- * to the caller to fix this, but this doesn't really hurt.
- */
- if (type == LXC_AUTO_CGROUP_FULL_NOSPEC)
- type = LXC_AUTO_CGROUP_FULL_MIXED;
- else if (type == LXC_AUTO_CGROUP_NOSPEC)
- type = LXC_AUTO_CGROUP_MIXED;
-
- if (type < LXC_AUTO_CGROUP_RO || type > LXC_AUTO_CGROUP_FULL_MIXED) {
- ERROR("could not mount cgroups into container: invalid type specified internally");
- errno = EINVAL;
- return false;
- }
-
- path = calloc(1, bufsz);
- if (!path)
- return false;
- snprintf(path, bufsz, "%s/sys/fs/cgroup", root);
- r = safe_mount("cgroup_root", path, "tmpfs",
- MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_RELATIME,
- "size=10240k,mode=755",
- root);
- if (r < 0) {
- SYSERROR("could not mount tmpfs to /sys/fs/cgroup in the container");
- return false;
- }
-
- /* now mount all the hierarchies we care about */
- for (info = base_info; info; info = info->next) {
- size_t subsystem_count, i;
- struct cgroup_mount_point *mp = info->designated_mount_point;
-
- if (!info->hierarchy)
- continue;
-
- if (!mountpoint_is_accessible(mp))
- mp = lxc_cgroup_find_mount_point(info->hierarchy, info->cgroup_path, true);
-
- if (!mp) {
- SYSERROR("could not find original mount point for cgroup hierarchy while trying to mount cgroup filesystem");
- goto out_error;
- }
-
- subsystem_count = lxc_array_len((void **)info->hierarchy->subsystems);
- parts = calloc(subsystem_count + 1, sizeof(char *));
- if (!parts)
- goto out_error;
-
- for (i = 0; i < subsystem_count; i++) {
- if (!strncmp(info->hierarchy->subsystems[i], "name=", 5))
- parts[i] = info->hierarchy->subsystems[i] + 5;
- else
- parts[i] = info->hierarchy->subsystems[i];
- }
- dirname = lxc_string_join(",", (const char **)parts, false);
- if (!dirname)
- goto out_error;
-
- /* create subsystem directory */
- abs_path = lxc_append_paths(path, dirname);
- if (!abs_path)
- goto out_error;
- r = mkdir_p(abs_path, 0755);
- if (r < 0 && errno != EEXIST) {
- SYSERROR("could not create cgroup subsystem directory /sys/fs/cgroup/%s", dirname);
- goto out_error;
- }
-
- abs_path2 = lxc_append_paths(abs_path, info->cgroup_path);
- if (!abs_path2)
- goto out_error;
-
- if (type == LXC_AUTO_CGROUP_FULL_RO || type == LXC_AUTO_CGROUP_FULL_RW || type == LXC_AUTO_CGROUP_FULL_MIXED) {
- /* bind-mount the cgroup entire filesystem there */
- if (strcmp(mp->mount_prefix, "/") != 0) {
- /* FIXME: maybe we should just try to remount the entire hierarchy
- * with a regular mount command? may that works? */
- ERROR("could not automatically mount cgroup-full to /sys/fs/cgroup/%s: host has no mount point for this cgroup filesystem that has access to the root cgroup", dirname);
- goto out_error;
- }
- r = mount(mp->mount_point, abs_path, "none", MS_BIND, 0);
- if (r < 0) {
- SYSERROR("error bind-mounting %s to %s", mp->mount_point, abs_path);
- goto out_error;
- }
- /* main cgroup path should be read-only */
- if (type == LXC_AUTO_CGROUP_FULL_RO || type == LXC_AUTO_CGROUP_FULL_MIXED) {
- r = mount(NULL, abs_path, NULL, MS_REMOUNT|MS_BIND|MS_RDONLY, NULL);
- if (r < 0) {
- SYSERROR("error re-mounting %s readonly", abs_path);
- goto out_error;
- }
- }
- /* own cgroup should be read-write */
- if (type == LXC_AUTO_CGROUP_FULL_MIXED) {
- r = mount(abs_path2, abs_path2, NULL, MS_BIND, NULL);
- if (r < 0) {
- SYSERROR("error bind-mounting %s onto itself", abs_path2);
- goto out_error;
- }
- r = mount(NULL, abs_path2, NULL, MS_REMOUNT|MS_BIND, NULL);
- if (r < 0) {
- SYSERROR("error re-mounting %s readwrite", abs_path2);
- goto out_error;
- }
- }
- } else {
- /* create path for container's cgroup */
- r = mkdir_p(abs_path2, 0755);
- if (r < 0 && errno != EEXIST) {
- SYSERROR("could not create cgroup directory /sys/fs/cgroup/%s%s", dirname, info->cgroup_path);
- goto out_error;
- }
-
- /* for read-only and mixed cases, we have to bind-mount the tmpfs directory
- * that points to the hierarchy itself (i.e. /sys/fs/cgroup/cpu etc.) onto
- * itself and then bind-mount it read-only, since we keep the tmpfs itself
- * read-write (see comment below)
- */
- if (type == LXC_AUTO_CGROUP_MIXED || type == LXC_AUTO_CGROUP_RO) {
- r = mount(abs_path, abs_path, NULL, MS_BIND, NULL);
- if (r < 0) {
- SYSERROR("error bind-mounting %s onto itself", abs_path);
- goto out_error;
- }
- r = mount(NULL, abs_path, NULL, MS_REMOUNT|MS_BIND|MS_RDONLY, NULL);
- if (r < 0) {
- SYSERROR("error re-mounting %s readonly", abs_path);
- goto out_error;
- }
- }
-
- free(abs_path);
- abs_path = NULL;
-
- /* bind-mount container's cgroup to that directory */
- abs_path = cgroup_to_absolute_path(mp, info->cgroup_path, NULL);
- if (!abs_path)
- goto out_error;
- r = mount(abs_path, abs_path2, "none", MS_BIND, 0);
- if (r < 0 && is_crucial_hierarchy(info->hierarchy)) {
- SYSERROR("error bind-mounting %s to %s", abs_path, abs_path2);
- goto out_error;
- }
- if (type == LXC_AUTO_CGROUP_RO) {
- r = mount(NULL, abs_path2, NULL, MS_REMOUNT|MS_BIND|MS_RDONLY, NULL);
- if (r < 0) {
- SYSERROR("error re-mounting %s readonly", abs_path2);
- goto out_error;
- }
- }
- }
-
- free(abs_path);
- free(abs_path2);
- abs_path = NULL;
- abs_path2 = NULL;
-
- /* add symlinks for every single subsystem */
- if (subsystem_count > 1) {
- for (i = 0; i < subsystem_count; i++) {
- abs_path = lxc_append_paths(path, parts[i]);
- if (!abs_path)
- goto out_error;
- r = symlink(dirname, abs_path);
- if (r < 0)
- WARN("could not create symlink %s -> %s in /sys/fs/cgroup of container", parts[i], dirname);
- free(abs_path);
- abs_path = NULL;
- }
- }
- free(dirname);
- free(parts);
- dirname = NULL;
- parts = NULL;
- }
-
- /* We used to remount the entire tmpfs readonly if any :ro or
- * :mixed mode was specified. However, Ubuntu's mountall has the
- * unfortunate behavior to block bootup if /sys/fs/cgroup is
- * mounted read-only and cannot be remounted read-write.
- * (mountall reads /lib/init/fstab and tries to (re-)mount all of
- * these if they are not already mounted with the right options;
- * it contains an entry for /sys/fs/cgroup. In case it can't do
- * that, it prompts for the user to either manually fix it or
- * boot anyway. But without user input, booting of the container
- * hangs.)
- *
- * Instead of remounting the entire tmpfs readonly, we only
- * remount the paths readonly that are part of the cgroup
- * hierarchy.
- */
-
- free(path);
-
- return true;
-
-out_error:
- saved_errno = errno;
- free(path);
- free(dirname);
- free(parts);
- free(abs_path);
- free(abs_path2);
- errno = saved_errno;
- return false;
-}
-
-static int cgfs_nrtasks(void *hdata)
-{
- struct cgfs_data *d = hdata;
- struct cgroup_process_info *info;
- struct cgroup_mount_point *mp = NULL;
- char *abs_path = NULL;
- int ret;
-
- if (!d) {
- errno = ENOENT;
- return -1;
- }
-
- info = d->info;
- if (!info) {
- errno = ENOENT;
- return -1;
- }
-
- if (info->designated_mount_point) {
- mp = info->designated_mount_point;
- } else {
- mp = lxc_cgroup_find_mount_point(info->hierarchy, info->cgroup_path, false);
- if (!mp)
- return -1;
- }
-
- abs_path = cgroup_to_absolute_path(mp, info->cgroup_path, NULL);
- if (!abs_path)
- return -1;
-
- ret = cgroup_recursive_task_count(abs_path);
- free(abs_path);
- return ret;
-}
-
-static struct cgroup_process_info *
-lxc_cgroup_process_info_getx(const char *proc_pid_cgroup_str,
- struct cgroup_meta_data *meta)
-{
- struct cgroup_process_info *result = NULL;
- FILE *proc_pid_cgroup = NULL;
- char *line = NULL;
- size_t sz = 0;
- int saved_errno = 0;
- struct cgroup_process_info **cptr = &result;
- struct cgroup_process_info *entry = NULL;
-
- proc_pid_cgroup = fopen_cloexec(proc_pid_cgroup_str, "r");
- if (!proc_pid_cgroup)
- return NULL;
-
- while (getline(&line, &sz, proc_pid_cgroup) != -1) {
- /* file format: hierarchy:subsystems:group */
- char *colon1;
- char *colon2;
- char *endptr;
- int hierarchy_number;
- struct cgroup_hierarchy *h = NULL;
-
- if (!line[0])
- continue;
-
- if (line[strlen(line) - 1] == '\n')
- line[strlen(line) - 1] = '\0';
-
- colon1 = strchr(line, ':');
- if (!colon1)
- continue;
- *colon1++ = '\0';
- colon2 = strchr(colon1, ':');
- if (!colon2)
- continue;
- *colon2++ = '\0';
-
- endptr = NULL;
-
- /* With cgroupv2 /proc/self/cgroup can contain entries of the
- * form: 0::/
- * These entries need to be skipped.
- */
- if (!strcmp(colon1, ""))
- continue;
-
- hierarchy_number = strtoul(line, &endptr, 10);
- if (!endptr || *endptr)
- continue;
-
- if (hierarchy_number > meta->maximum_hierarchy) {
- /* we encountered a hierarchy we didn't have before,
- * so probably somebody remounted some stuff in the
- * mean time...
- */
- errno = EAGAIN;
- goto out_error;
- }
-
- h = meta->hierarchies[hierarchy_number];
- if (!h) {
- /* we encountered a hierarchy that was thought to be
- * dead before, so probably somebody remounted some
- * stuff in the mean time...
- */
- errno = EAGAIN;
- goto out_error;
- }
-
- /* we are told that we should ignore this hierarchy */
- if (!h->used)
- continue;
-
- entry = calloc(1, sizeof(struct cgroup_process_info));
- if (!entry)
- goto out_error;
-
- entry->meta_ref = lxc_cgroup_get_meta(meta);
- entry->hierarchy = h;
- entry->cgroup_path = strdup(colon2);
- if (!entry->cgroup_path)
- goto out_error;
- prune_init_scope(entry->cgroup_path);
-
- *cptr = entry;
- cptr = &entry->next;
- entry = NULL;
- }
-
- fclose(proc_pid_cgroup);
- free(line);
- return result;
-
-out_error:
- saved_errno = errno;
- if (proc_pid_cgroup)
- fclose(proc_pid_cgroup);
- lxc_cgroup_process_info_free(result);
- lxc_cgroup_process_info_free(entry);
- free(line);
- errno = saved_errno;
- return NULL;
-}
-
-static char **subsystems_from_mount_options(const char *mount_options,
- char **kernel_list)
-{
- char *token, *str, *saveptr = NULL;
- char **result = NULL;
- size_t result_capacity = 0;
- size_t result_count = 0;
- int saved_errno;
- int r;
-
- str = alloca(strlen(mount_options)+1);
- strcpy(str, mount_options);
- for (; (token = strtok_r(str, ",", &saveptr)); str = NULL) {
- /* we have a subsystem if it's either in the list of
- * subsystems provided by the kernel OR if it starts
- * with name= for named hierarchies
- */
- r = lxc_grow_array((void ***)&result, &result_capacity, result_count + 1, 12);
- if (r < 0)
- goto out_free;
- result[result_count + 1] = NULL;
- if (strncmp(token, "name=", 5) && !lxc_string_in_array(token, (const char **)kernel_list)) {
- /* this is eg 'systemd' but the mount will be
- * 'name=systemd'
- */
- result[result_count] = malloc(strlen(token) + 6);
- if (result[result_count])
- sprintf(result[result_count], "name=%s", token);
- } else
- result[result_count] = strdup(token);
- if (!result[result_count])
- goto out_free;
- result_count++;
- }
-
- return result;
-
-out_free:
- saved_errno = errno;
- lxc_free_array((void**)result, free);
- errno = saved_errno;
- return NULL;
-}
-
-static void lxc_cgroup_mount_point_free(struct cgroup_mount_point *mp)
-{
- if (!mp)
- return;
- free(mp->mount_point);
- free(mp->mount_prefix);
- free(mp);
-}
-
-static void lxc_cgroup_hierarchy_free(struct cgroup_hierarchy *h)
-{
- if (!h)
- return;
- if (h->subsystems) {
- lxc_free_array((void **)h->subsystems, free);
- h->subsystems = NULL;
- }
- if (h->all_mount_points) {
- free(h->all_mount_points);
- h->all_mount_points = NULL;
- }
- free(h);
- h = NULL;
-}
-
-static bool is_valid_cgroup(const char *name)
-{
- const char *p;
- for (p = name; *p; p++) {
- /* Use the ASCII printable characters range(32 - 127)
- * is reasonable, we kick out 32(SPACE) because it'll
- * break legacy lxc-ls
- */
- if (*p <= 32 || *p >= 127 || *p == '/')
- return false;
- }
- return strcmp(name, ".") != 0 && strcmp(name, "..") != 0;
-}
-
-static int create_or_remove_cgroup(bool do_remove,
- struct cgroup_mount_point *mp, const char *path, int recurse,
- struct lxc_conf *conf)
-{
- int r, saved_errno = 0;
- char *buf = cgroup_to_absolute_path(mp, path, NULL);
- if (!buf)
- return -1;
-
- /* create or remove directory */
- if (do_remove) {
- if (!dir_exists(buf))
- return 0;
- if (recurse) {
- if (conf && !lxc_list_empty(&conf->id_map))
- r = userns_exec_1(conf, rmdir_wrapper, buf,
- "rmdir_wrapper");
- else
- r = cgroup_rmdir(buf);
- } else
- r = rmdir(buf);
- } else
- r = mkdir_p(buf, 0777);
- saved_errno = errno;
- free(buf);
- errno = saved_errno;
- return r;
-}
-
-static int create_cgroup(struct cgroup_mount_point *mp, const char *path)
-{
- return create_or_remove_cgroup(false, mp, path, false, NULL);
-}
-
-static int remove_cgroup(struct cgroup_mount_point *mp,
- const char *path, bool recurse, struct lxc_conf *conf)
-{
- return create_or_remove_cgroup(true, mp, path, recurse, conf);
-}
-
-static char *cgroup_to_absolute_path(struct cgroup_mount_point *mp,
- const char *path, const char *suffix)
-{
- /* first we have to make sure we subtract the mount point's prefix */
- char *prefix = mp->mount_prefix;
- char *buf;
- ssize_t len, rv;
-
- /* we want to make sure only absolute paths to cgroups are passed to us */
- if (path[0] != '/') {
- errno = EINVAL;
- return NULL;
- }
-
- if (prefix && !strcmp(prefix, "/"))
- prefix = NULL;
-
- /* prefix doesn't match */
- if (prefix && strncmp(prefix, path, strlen(prefix)) != 0) {
- errno = EINVAL;
- return NULL;
- }
- /* if prefix is /foo and path is /foobar */
- if (prefix && path[strlen(prefix)] != '/' && path[strlen(prefix)] != '\0') {
- errno = EINVAL;
- return NULL;
- }
-
- /* remove prefix from path */
- path += prefix ? strlen(prefix) : 0;
-
- len = strlen(mp->mount_point) + strlen(path) + (suffix ? strlen(suffix) : 0);
- buf = calloc(len + 1, 1);
- if (!buf)
- return NULL;
- rv = snprintf(buf, len + 1, "%s%s%s", mp->mount_point, path, suffix ? suffix : "");
- if (rv > len) {
- free(buf);
- errno = ENOMEM;
- return NULL;
- }
-
- return buf;
-}
-
-static struct cgroup_process_info *
-find_info_for_subsystem(struct cgroup_process_info *info, const char *subsystem)
-{
- struct cgroup_process_info *info_ptr;
- for (info_ptr = info; info_ptr; info_ptr = info_ptr->next) {
- struct cgroup_hierarchy *h = info_ptr->hierarchy;
- if (!h)
- continue;
- if (lxc_string_in_array(subsystem, (const char **)h->subsystems))
- return info_ptr;
- }
- errno = ENOENT;
- return NULL;
-}
-
-static int do_cgroup_get(const char *cgroup_path, const char *sub_filename,
- char *value, size_t len)
-{
- const char *parts[3] = {
- cgroup_path,
- sub_filename,
- NULL
- };
- char *filename;
- int ret, saved_errno;
-
- filename = lxc_string_join("/", parts, false);
- if (!filename)
- return -1;
-
- ret = lxc_read_from_file(filename, value, len);
- saved_errno = errno;
- free(filename);
- errno = saved_errno;
- return ret;
-}
-
-static int do_cgroup_set(const char *cgroup_path, const char *sub_filename,
- const char *value)
-{
- const char *parts[3] = {
- cgroup_path,
- sub_filename,
- NULL
- };
- char *filename;
- int ret, saved_errno;
-
- filename = lxc_string_join("/", parts, false);
- if (!filename)
- return -1;
-
- ret = lxc_write_to_file(filename, value, strlen(value), false);
- saved_errno = errno;
- free(filename);
- errno = saved_errno;
- return ret;
-}
-
-static int do_setup_cgroup_limits(struct cgfs_data *d,
- struct lxc_list *cgroup_settings, bool do_devices)
-{
- struct lxc_list *iterator, *sorted_cgroup_settings, *next;
- struct lxc_cgroup *cg;
- int ret = -1;
-
- if (lxc_list_empty(cgroup_settings))
- return 0;
-
- sorted_cgroup_settings = sort_cgroup_settings(cgroup_settings);
- if (!sorted_cgroup_settings) {
- return -1;
- }
-
- lxc_list_for_each(iterator, sorted_cgroup_settings) {
- cg = iterator->elem;
-
- if (do_devices == !strncmp("devices", cg->subsystem, 7)) {
- if (strcmp(cg->subsystem, "devices.deny") == 0 &&
- cgroup_devices_has_allow_or_deny(d, cg->value, false))
- continue;
- if (strcmp(cg->subsystem, "devices.allow") == 0 &&
- cgroup_devices_has_allow_or_deny(d, cg->value, true))
- continue;
- if (lxc_cgroup_set_data(cg->subsystem, cg->value, d)) {
- if (do_devices && (errno == EACCES || errno == EPERM)) {
- WARN("Error setting %s to %s for %s",
- cg->subsystem, cg->value, d->name);
- continue;
- }
- SYSERROR("Error setting %s to %s for %s",
- cg->subsystem, cg->value, d->name);
- goto out;
- }
- }
-
- DEBUG("cgroup '%s' set to '%s'", cg->subsystem, cg->value);
- }
-
- ret = 0;
- INFO("cgroup has been setup");
-out:
- lxc_list_for_each_safe(iterator, sorted_cgroup_settings, next) {
- lxc_list_del(iterator);
- free(iterator);
- }
- free(sorted_cgroup_settings);
- return ret;
-}
-
-static bool cgroup_devices_has_allow_or_deny(struct cgfs_data *d,
- char *v, bool for_allow)
-{
- char *path;
- FILE *devices_list;
- char *line = NULL;
- size_t sz = 0;
- bool ret = !for_allow;
- const char *parts[3] = {
- NULL,
- "devices.list",
- NULL
- };
-
- /* XXX FIXME if users could use something other than 'lxc.devices.deny =
- * a'. not sure they ever do, but they *could* right now, I'm assuming
- * they do NOT
- */
- if (!for_allow && strcmp(v, "a") != 0 && strcmp(v, "a *:* rwm") != 0)
- return false;
-
- parts[0] = (const char *)lxc_cgroup_get_hierarchy_abs_path_data("devices", d);
- if (!parts[0])
- return false;
- path = lxc_string_join("/", parts, false);
- if (!path) {
- free((void *)parts[0]);
- return false;
- }
-
- devices_list = fopen_cloexec(path, "r");
- if (!devices_list) {
- free(path);
- return false;
- }
-
- while (getline(&line, &sz, devices_list) != -1) {
- size_t len = strlen(line);
- if (len > 0 && line[len-1] == '\n')
- line[len-1] = '\0';
- if (strcmp(line, "a *:* rwm") == 0) {
- ret = for_allow;
- goto out;
- } else if (for_allow && strcmp(line, v) == 0) {
- ret = true;
- goto out;
- }
- }
-
-out:
- fclose(devices_list);
- free(line);
- free(path);
- return ret;
-}
-
-static int cgroup_recursive_task_count(const char *cgroup_path)
-{
- DIR *d;
- struct dirent *dent;
- int n = 0, r;
-
- d = opendir(cgroup_path);
- if (!d)
- return 0;
-
- while ((dent = readdir(d))) {
- const char *parts[3] = {
- cgroup_path,
- dent->d_name,
- NULL
- };
- char *sub_path;
- struct stat st;
-
- if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, ".."))
- continue;
- sub_path = lxc_string_join("/", parts, false);
- if (!sub_path) {
- closedir(d);
- return -1;
- }
- r = stat(sub_path, &st);
- if (r < 0) {
- closedir(d);
- free(sub_path);
- return -1;
- }
- if (S_ISDIR(st.st_mode)) {
- r = cgroup_recursive_task_count(sub_path);
- if (r >= 0)
- n += r;
- } else if (!strcmp(dent->d_name, "tasks")) {
- r = lxc_count_file_lines(sub_path);
- if (r >= 0)
- n += r;
- }
- free(sub_path);
- }
- closedir(d);
-
- return n;
-}
-
-static int handle_cgroup_settings(struct cgroup_mount_point *mp,
- char *cgroup_path)
-{
- int r, saved_errno = 0;
- char buf[2];
-
- mp->need_cpuset_init = false;
-
- /* If this is the memory cgroup, we want to enforce hierarchy.
- * But don't fail if for some reason we can't.
- */
- if (lxc_string_in_array("memory", (const char **)mp->hierarchy->subsystems)) {
- char *cc_path = cgroup_to_absolute_path(mp, cgroup_path, "/memory.use_hierarchy");
- if (cc_path) {
- r = lxc_read_from_file(cc_path, buf, 1);
- if (r < 1 || buf[0] != '1') {
- r = lxc_write_to_file(cc_path, "1", 1, false);
- if (r < 0)
- SYSERROR("failed to set memory.use_hierarchy to 1; continuing");
- }
- free(cc_path);
- }
- }
-
- /* if this is a cpuset hierarchy, we have to set cgroup.clone_children in
- * the base cgroup, otherwise containers will start with an empty cpuset.mems
- * and cpuset.cpus and then
- */
- if (lxc_string_in_array("cpuset", (const char **)mp->hierarchy->subsystems)) {
- char *cc_path = cgroup_to_absolute_path(mp, cgroup_path, "/cgroup.clone_children");
- struct stat sb;
-
- if (!cc_path)
- return -1;
- /* cgroup.clone_children is not available when running under
- * older kernel versions; in this case, we'll initialize
- * cpuset.cpus and cpuset.mems later, after the new cgroup
- * was created
- */
- if (stat(cc_path, &sb) != 0 && errno == ENOENT) {
- mp->need_cpuset_init = true;
- free(cc_path);
- return 0;
- }
- r = lxc_read_from_file(cc_path, buf, 1);
- if (r == 1 && buf[0] == '1') {
- free(cc_path);
- return 0;
- }
- r = lxc_write_to_file(cc_path, "1", 1, false);
- saved_errno = errno;
- free(cc_path);
- errno = saved_errno;
- return r < 0 ? -1 : 0;
- }
- return 0;
-}
-
-static int cgroup_read_from_file(const char *fn, char buf[], size_t bufsize)
-{
- int ret = lxc_read_from_file(fn, buf, bufsize);
- if (ret < 0) {
- SYSERROR("failed to read %s", fn);
- return ret;
- }
- if (ret == bufsize) {
- if (bufsize > 0) {
- /* obviously this wasn't empty */
- buf[bufsize-1] = '\0';
- return ret;
- }
- /* Callers don't do this, but regression/sanity check */
- ERROR("was not expecting 0 bufsize");
- return -1;
- }
- buf[ret] = '\0';
- return ret;
-}
-
-static bool do_init_cpuset_file(struct cgroup_mount_point *mp,
- const char *path, const char *name)
-{
- char value[1024];
- char *childfile, *parentfile = NULL, *tmp;
- int ret;
- bool ok = false;
-
- childfile = cgroup_to_absolute_path(mp, path, name);
- if (!childfile)
- return false;
-
- /* don't overwrite a non-empty value in the file */
- ret = cgroup_read_from_file(childfile, value, sizeof(value));
- if (ret < 0)
- goto out;
- if (value[0] != '\0' && value[0] != '\n') {
- ok = true;
- goto out;
- }
-
- /* path to the same name in the parent cgroup */
- parentfile = strdup(path);
- if (!parentfile)
- goto out;
-
- tmp = strrchr(parentfile, '/');
- if (!tmp)
- goto out;
- if (tmp == parentfile)
- tmp++; /* keep the '/' at the start */
- *tmp = '\0';
- tmp = parentfile;
- parentfile = cgroup_to_absolute_path(mp, tmp, name);
- free(tmp);
- if (!parentfile)
- goto out;
-
- /* copy from parent to child cgroup */
- ret = cgroup_read_from_file(parentfile, value, sizeof(value));
- if (ret < 0)
- goto out;
- if (ret == sizeof(value)) {
- /* If anyone actually sees this error, we can address it */
- ERROR("parent cpuset value too long");
- goto out;
- }
- ok = (lxc_write_to_file(childfile, value, strlen(value), false) >= 0);
- if (!ok)
- SYSERROR("failed writing %s", childfile);
-
-out:
- free(parentfile);
- free(childfile);
- return ok;
-}
-
-static bool init_cpuset_if_needed(struct cgroup_mount_point *mp,
- const char *path)
-{
- /* the files we have to handle here are only in cpuset hierarchies */
- if (!lxc_string_in_array("cpuset",
- (const char **)mp->hierarchy->subsystems))
- return true;
-
- if (!mp->need_cpuset_init)
- return true;
-
- return (do_init_cpuset_file(mp, path, "/cpuset.cpus") &&
- do_init_cpuset_file(mp, path, "/cpuset.mems") );
-}
-
-static void print_cgfs_init_debuginfo(struct cgfs_data *d)
-{
- int i;
-
- if (!getenv("LXC_DEBUG_CGFS"))
- return;
-
- DEBUG("Cgroup information:");
- DEBUG(" container name: %s", d->name);
- if (!d->meta || !d->meta->hierarchies) {
- DEBUG(" No hierarchies found.");
- return;
- }
- DEBUG(" Controllers:");
- for (i = 0; i <= d->meta->maximum_hierarchy; i++) {
- char **p;
- struct cgroup_hierarchy *h = d->meta->hierarchies[i];
- if (!h) {
- DEBUG(" Empty hierarchy number %d.", i);
- continue;
- }
- for (p = h->subsystems; p && *p; p++) {
- DEBUG(" %2d: %s", i, *p);
- }
- }
-}
-
-struct cgroup_ops *cgfs_ops_init(void)
-{
- return &cgfs_ops;
-}
-
-static void *cgfs_init(struct lxc_handler *handler)
-{
- struct cgfs_data *d;
-
- d = malloc(sizeof(*d));
- if (!d)
- return NULL;
-
- memset(d, 0, sizeof(*d));
- d->name = strdup(handler->name);
- if (!d->name)
- goto err1;
-
- d->cgroup_pattern = lxc_global_config_value("lxc.cgroup.pattern");
-
- d->meta = lxc_cgroup_load_meta();
- if (!d->meta) {
- ERROR("cgroupfs failed to detect cgroup metadata");
- goto err2;
- }
-
- print_cgfs_init_debuginfo(d);
-
- return d;
-
-err2:
- free(d->name);
-err1:
- free(d);
- return NULL;
-}
-
-static void cgfs_destroy(void *hdata, struct lxc_conf *conf)
-{
- struct cgfs_data *d = hdata;
-
- if (!d)
- return;
- free(d->name);
- lxc_cgroup_process_info_free_and_remove(d->info, conf);
- lxc_cgroup_put_meta(d->meta);
- free(d);
-}
-
-static inline bool cgfs_create(void *hdata)
-{
- struct cgfs_data *d = hdata;
- struct cgroup_process_info *i;
- struct cgroup_meta_data *md;
-
- if (!d)
- return false;
- md = d->meta;
- i = lxc_cgroupfs_create(d->name, d->cgroup_pattern, md, NULL);
- if (!i)
- return false;
- d->info = i;
- return true;
-}
-
-static inline bool cgfs_enter(void *hdata, pid_t pid)
-{
- struct cgfs_data *d = hdata;
- struct cgroup_process_info *i;
- int ret;
-
- if (!d)
- return false;
- i = d->info;
- ret = lxc_cgroupfs_enter(i, pid, false);
-
- return ret == 0;
-}
-
-static inline bool cgfs_create_legacy(void *hdata, pid_t pid)
-{
- struct cgfs_data *d = hdata;
- struct cgroup_process_info *i;
-
- if (!d)
- return false;
- i = d->info;
- if (lxc_cgroup_create_legacy(i, d->name, pid) < 0) {
- ERROR("failed to create legacy ns cgroups for '%s'", d->name);
- return false;
- }
- return true;
-}
-
-static const char *cgfs_get_cgroup(void *hdata, const char *subsystem)
-{
- struct cgfs_data *d = hdata;
-
- if (!d)
- return NULL;
- return lxc_cgroup_get_hierarchy_path_data(subsystem, d);
-}
-
-static bool cgfs_escape(void *hdata)
-{
- struct cgroup_meta_data *md;
- int i;
- bool ret = false;
-
- md = lxc_cgroup_load_meta();
- if (!md)
- return false;
-
- for (i = 0; i <= md->maximum_hierarchy; i++) {
- struct cgroup_hierarchy *h = md->hierarchies[i];
- struct cgroup_mount_point *mp;
- char *tasks;
- FILE *f;
- int written;
-
- if (!h) {
- WARN("not escaping hierarchy %d", i);
- continue;
- }
-
- mp = lxc_cgroup_find_mount_point(h, "/", true);
- if (!mp)
- goto out;
-
- tasks = cgroup_to_absolute_path(mp, "/", "tasks");
- if (!tasks)
- goto out;
-
- f = fopen(tasks, "a");
- free(tasks);
- if (!f)
- goto out;
-
- written = fprintf(f, "%d\n", lxc_raw_getpid());
- fclose(f);
- if (written < 0) {
- SYSERROR("writing tasks failed\n");
- goto out;
- }
- }
-
- ret = true;
-out:
- lxc_cgroup_put_meta(md);
- return ret;
-}
-
-static int cgfs_num_hierarchies(void)
-{
- /* not implemented */
- return -1;
-}
-
-static bool cgfs_get_hierarchies(int i, char ***out)
-{
- /* not implemented */
- return false;
-}
-
-static bool cgfs_unfreeze(void *hdata)
-{
- struct cgfs_data *d = hdata;
- char *cgabspath, *cgrelpath;
- int ret;
-
- if (!d)
- return false;
-
- cgrelpath = lxc_cgroup_get_hierarchy_path_data("freezer", d);
- cgabspath = lxc_cgroup_find_abs_path("freezer", cgrelpath, true, NULL);
- if (!cgabspath)
- return false;
-
- ret = do_cgroup_set(cgabspath, "freezer.state", "THAWED");
- free(cgabspath);
- return ret == 0;
-}
-
-static bool cgroupfs_setup_limits(void *hdata, struct lxc_conf *conf,
- bool with_devices)
-{
- struct cgfs_data *d = hdata;
-
- if (!d)
- return false;
- return do_setup_cgroup_limits(d, &conf->cgroup, with_devices) == 0;
-}
-
-static bool lxc_cgroupfs_attach(const char *name, const char *lxcpath, pid_t pid)
-{
- struct cgroup_meta_data *meta_data;
- struct cgroup_process_info *container_info;
- int ret;
-
- meta_data = lxc_cgroup_load_meta();
- if (!meta_data) {
- ERROR("could not move attached process %d to cgroup of container", pid);
- return false;
- }
-
- container_info = lxc_cgroup_get_container_info(name, lxcpath, meta_data);
- lxc_cgroup_put_meta(meta_data);
- if (!container_info) {
- ERROR("could not move attached process %d to cgroup of container", pid);
- return false;
- }
-
- ret = lxc_cgroupfs_enter(container_info, pid, false);
- lxc_cgroup_process_info_free(container_info);
- if (ret < 0) {
- ERROR("could not move attached process %d to cgroup of container", pid);
- return false;
- }
- return true;
-}
-
-struct chown_data {
- const char *cgroup_path;
- uid_t origuid;
-};
-
-/*
- * TODO - someone should refactor this to unshare once passing all the paths
- * to be chowned in one go
- */
-static int chown_cgroup_wrapper(void *data)
-{
- struct chown_data *arg = data;
- uid_t destuid;
- char *fpath;
-
- if (setresgid(0,0,0) < 0)
- SYSERROR("Failed to setgid to 0");
- if (setresuid(0,0,0) < 0)
- SYSERROR("Failed to setuid to 0");
- if (setgroups(0, NULL) < 0)
- SYSERROR("Failed to clear groups");
- destuid = get_ns_uid(arg->origuid);
-
- if (chown(arg->cgroup_path, destuid, 0) < 0)
- SYSERROR("Failed chowning %s to %d", arg->cgroup_path, (int)destuid);
-
- fpath = lxc_append_paths(arg->cgroup_path, "tasks");
- if (!fpath)
- return -1;
- if (chown(fpath, destuid, 0) < 0)
- SYSERROR("Error chowning %s\n", fpath);
- free(fpath);
-
- fpath = lxc_append_paths(arg->cgroup_path, "cgroup.procs");
- if (!fpath)
- return -1;
- if (chown(fpath, destuid, 0) < 0)
- SYSERROR("Error chowning %s", fpath);
- free(fpath);
-
- return 0;
-}
-
-static bool do_cgfs_chown(char *cgroup_path, struct lxc_conf *conf)
-{
- struct chown_data data;
- char *fpath;
-
- if (!dir_exists(cgroup_path))
- return true;
-
- if (lxc_list_empty(&conf->id_map))
- /* If there's no mapping then we don't need to chown */
- return true;
-
- data.cgroup_path = cgroup_path;
- data.origuid = geteuid();
-
- /* Unpriv users can't chown it themselves, so chown from
- * a child namespace mapping both our own and the target uid
- */
- if (userns_exec_1(conf, chown_cgroup_wrapper, &data,
- "chown_cgroup_wrapper") < 0) {
- ERROR("Error requesting cgroup chown in new namespace");
- return false;
- }
-
- /*
- * Now chmod 775 the directory else the container cannot create cgroups.
- * This can't be done in the child namespace because it only group-owns
- * the cgroup
- */
- if (chmod(cgroup_path, 0775) < 0) {
- SYSERROR("Error chmoding %s\n", cgroup_path);
- return false;
- }
- fpath = lxc_append_paths(cgroup_path, "tasks");
- if (!fpath)
- return false;
- if (chmod(fpath, 0664) < 0)
- SYSERROR("Error chmoding %s\n", fpath);
- free(fpath);
- fpath = lxc_append_paths(cgroup_path, "cgroup.procs");
- if (!fpath)
- return false;
- if (chmod(fpath, 0664) < 0)
- SYSERROR("Error chmoding %s\n", fpath);
- free(fpath);
-
- return true;
-}
-
-static bool cgfs_chown(void *hdata, struct lxc_conf *conf)
-{
- struct cgfs_data *d = hdata;
- struct cgroup_process_info *info_ptr;
- char *cgpath;
- bool r = true;
-
- if (!d)
- return false;
-
- for (info_ptr = d->info; info_ptr; info_ptr = info_ptr->next) {
- if (!info_ptr->hierarchy)
- continue;
-
- if (!info_ptr->designated_mount_point) {
- info_ptr->designated_mount_point = lxc_cgroup_find_mount_point(info_ptr->hierarchy, info_ptr->cgroup_path, true);
- if (!info_ptr->designated_mount_point) {
- SYSERROR("Could not chown cgroup %s: internal error (couldn't find any writable mountpoint to cgroup filesystem)", info_ptr->cgroup_path);
- return false;
- }
- }
-
- cgpath = cgroup_to_absolute_path(info_ptr->designated_mount_point, info_ptr->cgroup_path, NULL);
- if (!cgpath) {
- SYSERROR("Could not chown cgroup %s: internal error", info_ptr->cgroup_path);
- continue;
- }
- r = do_cgfs_chown(cgpath, conf);
- if (!r && is_crucial_hierarchy(info_ptr->hierarchy)) {
- ERROR("Failed chowning %s\n", cgpath);
- free(cgpath);
- return false;
- }
- free(cgpath);
- }
-
- return true;
-}
-
-static struct cgroup_ops cgfs_ops = {
- .init = cgfs_init,
- .destroy = cgfs_destroy,
- .create = cgfs_create,
- .enter = cgfs_enter,
- .create_legacy = cgfs_create_legacy,
- .get_cgroup = cgfs_get_cgroup,
- .escape = cgfs_escape,
- .num_hierarchies = cgfs_num_hierarchies,
- .get_hierarchies = cgfs_get_hierarchies,
- .get = lxc_cgroupfs_get,
- .set = lxc_cgroupfs_set,
- .unfreeze = cgfs_unfreeze,
- .setup_limits = cgroupfs_setup_limits,
- .name = "cgroupfs",
- .attach = lxc_cgroupfs_attach,
- .chown = cgfs_chown,
- .mount_cgroup = cgroupfs_mount_cgroup,
- .nrtasks = cgfs_nrtasks,
- .driver = CGFS,
-};
projects / thirdparty / lxc.git / commitdiff
