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cgmanager.c
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cgmanager.c
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/* cgmanager
*
* Copyright © 2013 Stephane Graber
* Author: Stephane Graber <stgraber@ubuntu.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2, as
* published by the Free Software Foundation.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <frontend.h>
#include <sys/resource.h>
#include <sys/vfs.h>
#include <linux/fs.h>
struct autoremove_entry {
NihList entry;
char *gpath, *evpath, *dirname;
int wd_cg, wd_events;
NihIo *io;
};
/*
* Maximum depth of directories we allow in Create
* Default is 16. Figure 4 directories per level of container
* nesting (/user/1000.user/c2.session/c1), that lets us nest
* 4 containers deep.
*/
static int maxdepth = 16;
static NihList autoremove_entries;
/* GetPidCgroup */
int get_pid_cgroup_main(void *parent, char *controller, struct ucred p,
struct ucred r, struct ucred v, char **output)
{
char rcgpath[MAXPATHLEN], vcgpath[MAXPATHLEN];
if (!(prune_verify_comounts(controller))) {
nih_error("%s: Multiple controllers given: %s",
__func__, controller);
return -1;
}
// Get r's current cgroup in rcgpath
if (!compute_pid_cgroup(r.pid, controller, "", rcgpath, NULL)) {
nih_error("%s: Could not determine the requestor's cgroup for %s",
__func__, controller);
return -1;
}
// Get v's cgroup in vcgpath
if (!compute_pid_cgroup(v.pid, controller, "", vcgpath, NULL)) {
nih_error("%s: Could not determine the victim cgroup for %s",
__func__, controller);
return -1;
}
// Make sure v's cgroup is under r's
int rlen = strlen(rcgpath);
if (strncmp(rcgpath, vcgpath, rlen) != 0) {
nih_error("%s: v (%d)'s cgroup is not below r (%d)'s", __func__,
v.pid, r.pid);
return -1;
}
if (strlen(vcgpath) == rlen)
*output = NIH_MUST (nih_strdup(parent, "/") );
else
*output = NIH_MUST (nih_strdup(parent, vcgpath + rlen + 1) );
return 0;
}
/* GetPidCgroupAbs */
int get_pid_cgroup_abs_main(void *parent, char *controller,struct ucred p,
struct ucred r, struct ucred v, char **output)
{
char rcgpath[MAXPATHLEN], vcgpath[MAXPATHLEN];
if (!(prune_verify_comounts(controller))) {
nih_error("%s: Multiple controllers given: %s",
__func__, controller);
return -1;
}
// Get p's current cgroup in rcgpath
if (!compute_proxy_cgroup(p.pid, controller, "", rcgpath, NULL)) {
nih_error("%s: Could not determine the requestor's cgroup for %s",
__func__, controller);
return -1;
}
// Get v's cgroup in vcgpath
if (!compute_pid_cgroup(v.pid, controller, "", vcgpath, NULL)) {
nih_error("%s: Could not determine the victim cgroup for %s",
__func__, controller);
return -1;
}
// Make sure v's cgroup is under p's
int rlen = strlen(rcgpath);
if (strncmp(rcgpath, vcgpath, rlen) != 0) {
nih_error("%s: v (%d)'s cgroup is not below p (%d)'s", __func__,
v.pid, p.pid);
return -1;
}
if (strlen(vcgpath) == rlen)
*output = NIH_MUST (nih_strdup(parent, "/") );
else
*output = NIH_MUST (nih_strdup(parent, vcgpath + rlen) );
return 0;
}
static bool victim_under_proxy_cgroup(char *rcgpath, pid_t v,
const char *controller)
{
char vcgpath[MAXPATHLEN];
if (!compute_pid_cgroup(v, controller, "", vcgpath, NULL)) {
nih_error("%s: Could not determine the victim's cgroup for %s",
__func__, controller);
return false;
}
if (strncmp(vcgpath, rcgpath, strlen(rcgpath)) != 0)
return false;
return true;
}
int per_ctrl_move_pid_main(const char *controller, const char *cgroup, struct ucred p,
struct ucred r, struct ucred v, bool escape)
{
char rcgpath[MAXPATHLEN], path[MAXPATHLEN];
bool unified = false;
FILE *f;
pid_t query = r.pid;
size_t maxlen;
if (is_unified_controller(controller))
unified = true;
// Get r's current cgroup in rcgpath
if (escape)
query = p.pid;
if (!compute_proxy_cgroup(query, controller, "", rcgpath, NULL)) {
nih_error("%s: Could not determine the requestor's cgroup for %s",
__func__, controller);
return -1;
}
// If the victim is not under proxy's cgroup, refuse
if (!victim_under_proxy_cgroup(rcgpath, v.pid, controller)) {
nih_error("%s: victim's cgroup is not under proxy's (p.uid %u)", __func__, p.uid);
return -1;
}
if (unified) {
/* rcgpath + / + cgroup + "/.cgm_leaf/cgroup.procs" + \0 */
maxlen = strlen(rcgpath) + strlen(cgroup) + strlen(U_LEAF "/cgroup.procs") + 2;
} else {
/* rcgpath + / + cgroup + /tasks + \0 */
maxlen = strlen(rcgpath) + strlen(cgroup) + 8;
}
if (maxlen > MAXPATHLEN) {
nih_error("%s: Path name too long", __func__);
return -1;
}
strcpy(path, rcgpath);
strncat(path, "/", MAXPATHLEN-1);
strncat(path, cgroup, MAXPATHLEN-1);
if (realpath_escapes(path, rcgpath)) {
nih_error("%s: Invalid path %s", __func__, path);
return -1;
}
// is r allowed to descend under the parent dir?
if (!may_access(r.pid, r.uid, r.gid, path, O_RDONLY)) {
nih_error("%s: pid %d (uid %u gid %u) may not read under %s", __func__,
r.pid, r.uid, r.gid, path);
return -1;
}
// is r allowed to write to tasks file?
if (unified) {
if (!ensure_leafdir(controller, path))
return -1;
strcat(path, U_LEAF);
strcat(path, "/cgroup.procs");
} else {
strncat(path, "/tasks", MAXPATHLEN-1);
}
if (!may_access(r.pid, r.uid, r.gid, path, O_WRONLY)) {
nih_error("%s: pid %d (uid %u gid %u) may not write to %s", __func__,
r.pid, r.uid, r.gid, path);
return -1;
}
f = fopen(path, "w");
if (!f) {
nih_error("%s: Failed to open %s", __func__, path);
return -1;
}
if (fprintf(f, "%d\n", v.pid) < 0) {
fclose(f);
nih_error("%s: Failed to write %d to %s", __func__, v.pid, path);
return -1;
}
if (fclose(f) != 0) {
nih_error("%s: Failed to write %d to %s", __func__, v.pid, path);
return -1;
}
nih_info(_("%d moved to %s:%s by %d's request"), v.pid,
controller, cgroup, r.pid);
return 0;
}
int do_move_pid_main(const char *controller, const char *cgroup, struct ucred p,
struct ucred r, struct ucred v, bool escape)
{
nih_local char *c = NULL;
char *tok;
int ret;
int while_ret = 0;
if (!sane_cgroup(cgroup)) {
nih_error("%s: unsafe cgroup", __func__);
return -1;
}
// verify that ucred.pid may move target pid
if (!may_move_pid(r.pid, r.uid, v.pid)) {
nih_error("%s: %d may not move %d", __func__, r.pid, v.pid);
return -1;
}
if (strcmp(controller, "all") != 0 && !strchr(controller, ','))
return per_ctrl_move_pid_main(controller, cgroup, p, r, v, escape);
if (strcmp(controller, "all") == 0) {
if (!all_controllers)
return 0;
c = NIH_MUST( nih_strdup(NULL, all_controllers) );
} else {
c = NIH_MUST( nih_strdup(NULL, controller) );
do_prune_comounts(c);
}
tok = strtok(c, ",");
while (tok) {
ret = per_ctrl_move_pid_main(tok, cgroup, p, r, v, escape);
/* Save error for later (but ignore permission denied, -2),
but try to complete rest of moves anyway */
if (ret != 0 && ret != -2)
while_ret = -1;
tok = strtok(NULL, ",");
}
return while_ret;
}
int move_pid_main(const char *controller, const char *cgroup, struct ucred p,
struct ucred r, struct ucred v)
{
if (cgroup[0] == '/') {
// We could try to be accomodating, but let's not fool around right now
nih_error("%s: Bad requested cgroup path: %s", __func__, cgroup);
return -1;
}
return do_move_pid_main(controller, cgroup, p, r, v, false);
}
int move_pid_abs_main(const char *controller, const char *cgroup, struct ucred p,
struct ucred r, struct ucred v)
{
return do_move_pid_main(controller, cgroup, p, r, v, true);
}
int do_create_main(const char *controller, const char *cgroup, struct ucred p,
struct ucred r, int32_t *existed)
{
int ret, depth;
char rcgpath[MAXPATHLEN], path[MAXPATHLEN], dirpath[MAXPATHLEN];
nih_local char *copy = NULL;
size_t cgroup_len;
char *p1, *p2, oldp2;
*existed = 1;
// Get r's current cgroup in rcgpath
if (!compute_pid_cgroup(r.pid, controller, "", rcgpath, &depth)) {
nih_error("%s: Could not determine the requestor's cgroup for %s",
__func__, controller);
return -1;
}
if (depth > maxdepth) {
nih_error("%s: Cgroup too deep: %s/%s", __func__, rcgpath, cgroup);
return -1;
}
cgroup_len = strlen(cgroup);
if (strlen(rcgpath) + cgroup_len > MAXPATHLEN) {
nih_error("%s: Path name too long", __func__);
return -1;
}
copy = NIH_MUST( nih_strndup(NULL, cgroup, cgroup_len) );
strcpy(path, rcgpath);
strcpy(dirpath, rcgpath);
for (p1=copy; *p1; p1 = p2) {
*existed = -1;
for (p2=p1; *p2 && *p2 != '/'; p2++);
oldp2 = *p2;
*p2 = '\0';
if (strcmp(p1, "..") == 0) {
nih_error("%s: Invalid cgroup path at create: %s", __func__, p1);
return -1;
}
strncat(path, "/", MAXPATHLEN-1);
strncat(path, p1, MAXPATHLEN-1);
if (dir_exists(path)) {
*existed = 1;
// TODO - properly use execute perms
if (!may_access(r.pid, r.uid, r.gid, path, O_RDONLY)) {
nih_error("%s: pid %d (uid %u gid %u) may not look under %s", __func__,
r.pid, r.uid, r.gid, path);
return -2;
}
goto next;
}
if (!may_access(r.pid, r.uid, r.gid, dirpath, O_RDWR)) {
nih_error("%s: pid %d (uid %u gid %u) may not create under %s", __func__,
r.pid, r.uid, r.gid, dirpath);
return -2;
}
ret = mkdir(path, 0755);
if (ret < 0) { // Should we ignore EEXIST? Ok, but don't chown.
if (errno == EEXIST) {
*existed = 1;
goto next;
}
nih_error("%s: failed to create %s", __func__, path);
return -2;
}
if (!unified_copy_controllers(controller, path)) {
nih_error("%s: Failed to set cg controllers on %s", __func__,
path);
rmdir(path);
return -1;
}
if (!chown_cgroup_path(path, r.uid, r.gid, true,
is_unified_controller(controller))) {
nih_error("%s: Failed to change ownership on %s to %u:%u", __func__,
path, r.uid, r.gid);
rmdir(path);
return -1;
}
*existed = -1;
next:
strncat(dirpath, "/", MAXPATHLEN-1);
strncat(dirpath, p1, MAXPATHLEN-1);
*p2 = oldp2;
if (*p2)
p2++;
}
nih_info(_("Created %s for %d (%u:%u)"), path, r.pid,
r.uid, r.gid);
return 0;
}
int create_main(const char *controller, const char *cgroup, struct ucred p,
struct ucred r, int32_t *existed)
{
nih_local char *c = NULL;
char *tok;
int ret;
*existed = -1;
if (!cgroup || ! *cgroup) // nothing to do
return 0;
if (!sane_cgroup(cgroup)) {
nih_error("%s: unsafe cgroup", __func__);
return -1;
}
if (strcmp(controller, "all") != 0 && !strchr(controller, ','))
return do_create_main(controller, cgroup, p, r, existed);
if (strcmp(controller, "all") == 0) {
if (!all_controllers)
return 0;
c = NIH_MUST( nih_strdup(NULL, all_controllers) );
} else {
c = NIH_MUST( nih_strdup(NULL, controller) );
do_prune_comounts(c);
}
tok = strtok(c, ",");
while (tok) {
int32_t e = 1;
ret = do_create_main(tok, cgroup, p, r, &e);
if (ret == -2) // permission denied - ignore for group requests
goto next;
if (ret != 0)
return -1;
if (e == 1)
*existed = 1;
next:
tok = strtok(NULL, ",");
}
return 0;
}
int do_chown_main(const char *controller, const char *cgroup, struct ucred p,
struct ucred r, struct ucred v)
{
char rcgpath[MAXPATHLEN];
nih_local char *path = NULL;
// Get r's current cgroup in rcgpath
if (!compute_pid_cgroup(r.pid, controller, "", rcgpath, NULL)) {
nih_error("%s: Could not determine the requestor's cgroup for %s",
__func__, controller);
return -1;
}
/* rcgpath + / + cgroup + \0 */
if (strlen(rcgpath) + strlen(cgroup) > MAXPATHLEN+2) {
nih_error("%s: Path name too long", __func__);
return -1;
}
path = NIH_MUST( nih_sprintf(NULL, "%s/%s", rcgpath, cgroup) );
if (realpath_escapes(path, rcgpath)) {
nih_error("%s: Invalid path %s", __func__, path);
return -1;
}
// is r allowed to descend under the parent dir?
if (!may_access(r.pid, r.uid, r.gid, path, O_RDONLY)) {
nih_error("%s: pid %d (uid %u gid %u) may not read under %s", __func__,
r.pid, r.uid, r.gid, path);
return -2;
}
// does r have privilege over the cgroup dir?
if (!may_access(r.pid, r.uid, r.gid, path, O_RDWR)) {
nih_error("%s: Pid %d may not chown %s\n", __func__, r.pid, path);
return -2;
}
// go ahead and chown it.
if (!chown_cgroup_path(path, v.uid, v.gid, false,
is_unified_controller(controller))) {
nih_error("%s: Failed to change ownership on %s to %u:%u", __func__,
path, v.uid, v.gid);
return -2;
}
if (is_unified_controller(controller)) {
NIH_MUST( nih_strcat(&path, NULL, U_LEAF) );
if (dir_exists(path) && !chown_cgroup_path(path, v.uid, v.gid, false, true)) {
nih_warn("%s: Failed to chown leaf directory for %s to %u:%u",
__func__, path, v.uid, v.gid);
return -2;
}
}
return 0;
}
int chown_main(const char *controller, const char *cgroup, struct ucred p,
struct ucred r, struct ucred v)
{
uid_t uid;
nih_local char *c = NULL;
char *tok;
int ret;
/* If caller is not root in his userns, then he can't chown, as
* that requires privilege over two uids */
if (r.uid) {
if (!hostuid_to_ns(r.uid, r.pid, &uid) || uid != 0) {
nih_error("%s: Chown requested by non-root uid %u", __func__, r.uid);
return -1;
}
}
if (!sane_cgroup(cgroup)) {
nih_error("%s: unsafe cgroup", __func__);
return -1;
}
if (strcmp(controller, "all") != 0 && !strchr(controller, ','))
return do_chown_main(controller, cgroup, p, r, v);
if (strcmp(controller, "all") == 0) {
if (!all_controllers)
return 0;
c = NIH_MUST( nih_strdup(NULL, all_controllers) );
} else {
c = NIH_MUST( nih_strdup(NULL, controller) );
do_prune_comounts(c);
}
tok = strtok(c, ",");
while (tok) {
ret = do_chown_main(tok, cgroup, p, r, v);
if (ret == -2) // permission denied - ignore for group requests
goto next;
if (ret != 0)
return -1;
next:
tok = strtok(NULL, ",");
}
return 0;
}
int do_chmod_main(const char *controller, const char *cgroup, const char *file,
struct ucred p, struct ucred r, int mode)
{
char rcgpath[MAXPATHLEN];
nih_local char *path = NULL;
// Get r's current cgroup in rcgpath
if (!compute_pid_cgroup(r.pid, controller, "", rcgpath, NULL)) {
nih_error("%s: Could not determine the requestor's cgroup for %s",
__func__, controller);
return -1;
}
path = NIH_MUST( nih_sprintf(NULL, "%s/%s", rcgpath, cgroup) );
if (file && strlen(file))
NIH_MUST( nih_strcat_sprintf(&path, NULL, "/%s", file) );
if (realpath_escapes(path, rcgpath)) {
nih_error("%s: Invalid path %s", __func__, path);
return -1;
}
// is r allowed to descend under the parent dir?
if (!may_access(r.pid, r.uid, r.gid, path, O_RDONLY)) {
nih_error("%s: pid %d (uid %u gid %u) may not read under %s", __func__,
r.pid, r.uid, r.gid, path);
return -2;
}
// does r have privilege over the cgroup dir?
if (!may_access(r.pid, r.uid, r.gid, path, O_RDWR)) {
nih_error("%s: Pid %d may not chmod %s\n", __func__, r.pid, path);
return -2;
}
// go ahead and chmod it.
if (!chmod_cgroup_path(path, mode)) {
nih_error("%s: Failed to change mode on %s to %d", __func__,
path, mode);
return -2;
}
return 0;
}
int chmod_main(const char *controller, const char *cgroup, const char *file,
struct ucred p, struct ucred r, int mode)
{
nih_local char *c = NULL;
char *tok;
int ret;
if (!sane_cgroup(cgroup)) {
nih_error("%s: unsafe cgroup", __func__);
return -1;
}
if (file && ( strchr(file, '/') || strchr(file, '\\')) ) {
nih_error("%s: invalid file", __func__);
return -1;
}
if (strcmp(controller, "all") != 0 && !strchr(controller, ','))
return do_chmod_main(controller, cgroup, file, p, r, mode);
if (strcmp(controller, "all") == 0) {
if (!all_controllers)
return 0;
c = NIH_MUST( nih_strdup(NULL, all_controllers) );
} else {
c = NIH_MUST( nih_strdup(NULL, controller) );
do_prune_comounts(c);
}
tok = strtok(c, ",");
while (tok) {
ret = do_chmod_main(tok, cgroup, file, p, r, mode);
if (ret == -2) // permission denied - ignore for group requests
goto next;
if (ret != 0)
return -1;
next:
tok = strtok(NULL, ",");
}
return 0;
}
int get_value_main(void *parent, char *controller, const char *cgroup,
const char *key, struct ucred p, struct ucred r, char **value)
{
char path[MAXPATHLEN];
if (!(prune_verify_comounts(controller))) {
nih_error("%s: Multiple controllers given: %s",
__func__, controller);
return -1;
}
if (!sane_cgroup(cgroup)) {
nih_error("%s: unsafe cgroup", __func__);
return -1;
}
if (!compute_pid_cgroup(r.pid, controller, cgroup, path, NULL)) {
nih_error("%s: Could not determine the requested cgroup (%s:%s)",
__func__, controller, cgroup);
return -1;
}
/* Check access rights to the cgroup directory */
if (!may_access(r.pid, r.uid, r.gid, path, O_RDONLY)) {
nih_debug("%s: Pid %d may not access %s\n", __func__, r.pid, path);
return -1;
}
if (!path_is_under_proxycg(p.pid, controller, path)) {
nih_debug("%s: target cgroup is not below r (%d)'s", __func__,
r.pid);
return -1;
}
/* append the filename */
if (strlen(path) + strlen(key) + 2 > MAXPATHLEN) {
nih_error("%s: filename too long for cgroup %s key %s", __func__, path, key);
return -1;
}
strncat(path, "/", MAXPATHLEN-1);
strncat(path, key, MAXPATHLEN-1);
/* Check access rights to the file itself */
if (!may_access(r.pid, r.uid, r.gid, path, O_RDONLY)) {
nih_debug("%s: Pid %d may not access %s\n", __func__, r.pid, path);
return -1;
}
/* read and return the value */
*value = file_read_string(parent, path);
if (!*value) {
nih_error("%s: Failed to read value from %s", __func__, path);
return -1;
}
nih_info(_("Sending to client: %s"), *value);
return 0;
}
int set_value_main(char *controller, const char *cgroup,
const char *key, const char *value, struct ucred p,
struct ucred r)
{
char path[MAXPATHLEN];
if (!(prune_verify_comounts(controller))) {
nih_error("%s: Multiple controllers given: %s",
__func__, controller);
return -1;
}
if (!sane_cgroup(cgroup)) {
nih_error("%s: unsafe cgroup", __func__);
return -1;
}
if (!compute_pid_cgroup(r.pid, controller, cgroup, path, NULL)) {
nih_error("%s: Could not determine the requested cgroup (%s:%s)",
__func__, controller, cgroup);
return -1;
}
if (!path_is_under_proxycg(p.pid, controller, path)) {
nih_debug("%s: target cgroup is not below r (%d)'s", __func__,
r.pid);
return -1;
}
/* Check access rights to the cgroup directory */
if (!may_access(r.pid, r.uid, r.gid, path, O_RDONLY)) {
nih_debug("%s: Pid %d may not access %s\n", __func__, r.pid, path);
return -1;
}
/* append the filename */
if (strlen(path) + strlen(key) + 2 > MAXPATHLEN) {
nih_error("%s: filename too long for cgroup %s key %s", __func__, path, key);
return -1;
}
strncat(path, "/", MAXPATHLEN-1);
strncat(path, key, MAXPATHLEN-1);
/* Check access rights to the file itself */
if (!may_access(r.pid, r.uid, r.gid, path, O_WRONLY)) {
nih_debug("%s: Pid %d may not access %s\n", __func__, r.pid, path);
return -1;
}
/* read and return the value */
if (!set_value(controller, path, value)) {
nih_error("%s: Failed to set value %s to %s", __func__, path, value);
return -1;
}
return 0;
}
/*
* Refuse any '..', and consolidate any '//'
*/
static bool normalize_path(char *path)
{
if (strstr(path, ".."))
return false;
while ((path = strstr(path, "//")) != NULL) {
char *p2 = path+1;
while (*p2 == '/')
p2++;
memmove(path, p2, strlen(p2)+1);
path++;
}
return true;
}
/*
* Recursively delete a cgroup.
* Cgroup files can't be deleted, but are cleaned up when you remove the
* containing directory. A directory cannot be removed until all its
* children are removed, and can't be removed if any tasks remain.
*
* We allow any task which may write under /a/b to delete any cgroups
* under that, even if, say, it technically is not allowed to remove
* /a/b/c/d/.
*/
static int recursive_rmdir(char *path)
{
struct dirent dirent, *direntp;
DIR *dir;
int failed = 0;
dir = opendir(path);
if (!dir) {
nih_error("%s: Failed to open dir %s for recursive deletion", __func__, path);
return -1;
}
while (!readdir_r(dir, &dirent, &direntp)) {
struct stat mystat;
nih_local char *pathname = NULL;
int rc;
if (!direntp)
break;
if (!strcmp(direntp->d_name, ".") ||
!strcmp(direntp->d_name, ".."))
continue;
pathname = NIH_MUST( nih_sprintf(NULL, "%s/%s", path, direntp->d_name) );
rc = lstat(pathname, &mystat);
if (rc) {
failed = 1;
continue;
}
if (S_ISDIR(mystat.st_mode)) {
if (recursive_rmdir(pathname) < 0)
failed = 1;
}
}
if (closedir(dir) < 0)
failed = 1;
if (rmdir(path) < 0)
failed = 1;
return failed ? -1 : 0;
}
int do_remove_main(const char *controller, const char *cgroup, struct ucred p,
struct ucred r, int recursive, int32_t *existed)
{
char rcgpath[MAXPATHLEN];
size_t cgroup_len;
nih_local char *working = NULL, *copy = NULL, *wcgroup = NULL;
char *p1;
*existed = 1;
// Get r's current cgroup in rcgpath
if (!compute_pid_cgroup(r.pid, controller, "", rcgpath, NULL)) {
nih_error("%s: Could not determine the requestor's cgroup for %s",
__func__, controller);
return -1;
}
cgroup_len = strlen(cgroup);
if (strlen(rcgpath) + cgroup_len > MAXPATHLEN) {
nih_error("%s: Path name too long", __func__);
return -1;
}
wcgroup = NIH_MUST( nih_strdup(NULL, cgroup) );
if (!normalize_path(wcgroup))
return -1;
working = NIH_MUST( nih_strdup(NULL, rcgpath) );
NIH_MUST( nih_strcat(&working, NULL, "/") );
NIH_MUST( nih_strcat(&working, NULL, wcgroup) );
if (!dir_exists(working)) {
*existed = -1;
return 0;
}
// must have write access to the parent dir
copy = NIH_MUST( nih_strdup(NULL, working) );
if (!(p1 = strrchr(copy, '/')))
return -1;
*p1 = '\0';
if (!may_access(r.pid, r.uid, r.gid, copy, O_WRONLY)) {
nih_error("%s: pid %d (%u:%u) may not remove %s", __func__,
r.pid, r.uid, r.gid, copy);
return -2;
}
if (is_unified_controller(controller)) {
nih_local char *fpath = NULL;
fpath = NIH_MUST( nih_sprintf(NULL, "%s%s", working, U_LEAF) );
if (rmdir(fpath) < 0) {
nih_error("%s: Failed to remove %s: %s", __func__, fpath, strerror(errno));
return errno == EPERM ? -2 : -1;
}
}
if (!recursive) {
if (rmdir(working) < 0) {
nih_error("%s: Failed to remove %s: %s", __func__, working, strerror(errno));
return errno == EPERM ? -2 : -1;
}
} else if (recursive_rmdir(working) < 0)
return -1;
nih_info(_("Removed %s for %d (%u:%u)"), working, r.pid,
r.uid, r.gid);
return 0;
}
int remove_main(const char *controller, const char *cgroup, struct ucred p,
struct ucred r, int recursive, int32_t *existed)
{
nih_local char *c = NULL;
char *tok;
int ret;
*existed = 1;
if (!sane_cgroup(cgroup)) {
nih_error("%s: unsafe cgroup", __func__);
return -1;
}
if (strcmp(controller, "all") != 0 && !strchr(controller, ','))
return do_remove_main(controller, cgroup, p, r, recursive, existed);
if (strcmp(controller, "all") == 0) {
if (!all_controllers)
return 0;
c = NIH_MUST( nih_strdup(NULL, all_controllers) );
} else {
c = NIH_MUST( nih_strdup(NULL, controller) );
do_prune_comounts(c);
}
tok = strtok(c, ",");
while (tok) {
int32_t e = 1;
ret = do_remove_main(tok, cgroup, p, r, recursive, &e);
if (ret == -2) // permission denied - ignore for group requests
goto next;
if (ret != 0)
return -1;
if (!e)
*existed = 0;
next:
tok = strtok(NULL, ",");
}
return 0;
}
int get_tasks_main(void *parent, char *controller, const char *cgroup,
struct ucred p, struct ucred r, int32_t **pids)
{
char path[MAXPATHLEN];
const char *key = is_unified_controller(controller) ?
U_LEAF_NAME "/cgroup.procs" : "tasks";
int alloced_pids = 0, nrpids = 0;
if (!sane_cgroup(cgroup)) {
nih_error("%s: unsafe cgroup", __func__);
return -1;
}
if (!(prune_verify_comounts(controller))) {
nih_error("%s: Multiple controllers given: %s",
__func__, controller);
return -1;
}
if (!compute_pid_cgroup(r.pid, controller, cgroup, path, NULL)) {
nih_error("%s: Could not determine the requested cgroup (%s:%s)",
__func__, controller, cgroup);
return -1;
}
if (!path_is_under_proxycg(p.pid, controller, path)) {
nih_debug("%s: target cgroup is not below r (%d)'s", __func__,
r.pid);
return -1;
}
/* Check access rights to the cgroup directory */
if (!may_access(r.pid, r.uid, r.gid, path, O_RDONLY)) {
nih_debug("%s: Pid %d may not access %s\n", __func__, r.pid, path);
return -1;
}
/* append the filename */
if (strlen(path) + strlen(key) + 2 > MAXPATHLEN) {
nih_error("%s: filename too long for cgroup %s key %s", __func__, path, key);
return -1;
}
strncat(path, "/", MAXPATHLEN-1);
strncat(path, key, MAXPATHLEN-1);
*pids = NULL;
if (file_read_pids(parent, path, pids, &alloced_pids, &nrpids) < 0) {
if (*pids)
nih_free(*pids);
return -1;
}
return nrpids;
}
static int do_collect_tasks(void *parent, char **path, int32_t **pids,
int *alloced_pids, int *nrpids, bool is_unified)
{
struct dirent dirent, *direntp;
DIR *dir;
const char *key = is_unified ? U_LEAF_NAME "/cgroup.procs" : "tasks";
dir = opendir(*path);
if (!dir) {
nih_warn("%s: Failed to open dir %s for recursive collection",
__func__, *path);
return -2;
}
while (!readdir_r(dir, &dirent, &direntp)) {
struct stat mystat;
nih_local char *childname = NULL;
int rc;
if (!direntp)
break;
if (!strcmp(direntp->d_name, ".") ||
!strcmp(direntp->d_name, "..") ||
!strcmp(direntp->d_name, U_LEAF_NAME))
continue;
childname = NIH_MUST( nih_sprintf(NULL, "%s/%s", *path, direntp->d_name) );
rc = lstat(childname, &mystat);
if (rc)
continue;
if (S_ISDIR(mystat.st_mode))
if (do_collect_tasks(parent, &childname, pids,
alloced_pids, nrpids,
is_unified) == -1)
nih_info("%s: error descending subdirs", __func__);
}