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/*
* Copyright RedHat Inc. 2008
*
* Authors: Vivek Goyal <vgoyal@redhat.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2.1 of the GNU Lesser General Public License
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <libcgroup.h>
#include <limits.h>
#include <pwd.h>
#include <unistd.h>
#include <getopt.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "tools-common.h"
#define TEMP_BUF 81
/*
* Go through /proc/<pid>/status file to determine the euid of the
* process.
* It returns 0 on success and negative values on failure.
*/
int euid_of_pid(pid_t pid)
{
FILE *fp;
char path[FILENAME_MAX];
char buf[TEMP_BUF];
uid_t ruid, euid, suid, fsuid;
sprintf(path, "/proc/%d/status", pid);
fp = fopen(path, "r");
if (!fp) {
cgroup_dbg("Error in opening file %s:%s\n", path,
strerror(errno));
return -1;
}
while (fgets(buf, TEMP_BUF, fp)) {
if (!strncmp(buf, "Uid:", 4)) {
sscanf((buf + 5), "%d%d%d%d", (int *)&ruid,
(int *)&euid, (int *)&suid, (int *)&fsuid);
cgroup_dbg("Scanned proc values are %d %d %d %d\n",
ruid, euid, suid, fsuid);
return euid;
}
}
/* If we are here, we could not find euid. Return error. */
return -1;
}
/*
* Go through /proc/<pid>/status file to determine the egid of the
* process.
* It returns 0 on success and negative values on failure.
*/
int egid_of_pid(pid_t pid)
{
FILE *fp;
char path[FILENAME_MAX];
char buf[TEMP_BUF];
gid_t rgid, egid, sgid, fsgid;
sprintf(path, "/proc/%d/status", pid);
fp = fopen(path, "r");
if (!fp) {
cgroup_dbg("Error in opening file %s:%s\n", path,
strerror(errno));
return -1;
}
while (fgets(buf, TEMP_BUF, fp)) {
if (!strncmp(buf, "Gid:", 4)) {
sscanf((buf + 5), "%d%d%d%d", (int *)&rgid,
(int *)&egid, (int *)&sgid, (int *)&fsgid);
cgroup_dbg("Scanned proc values are %d %d %d %d\n",
rgid, egid, sgid, fsgid);
return egid;
}
}
/* If we are here, we could not find egid. Return error. */
return -1;
}
/*
* Change process group as specified on command line.
*/
int change_group_path(pid_t pid, struct cgroup_group_spec *cgroup_list[])
{
int i;
int ret = 0;
for (i = 0; i < CG_HIER_MAX; i++) {
if (!cgroup_list[i])
break;
ret = cgroup_change_cgroup_path(cgroup_list[i]->path, pid,
cgroup_list[i]->controllers);
if (ret)
fprintf(stderr, "Error changing group of pid %d: %s\n",
pid, cgroup_strerror(ret));
return -1;
}
return 0;
}
/*
* Change process group as specified in cgrules.conf.
*/
int change_group_uid_gid(pid_t pid)
{
uid_t euid;
gid_t egid;
int ret;
/* Put pid into right cgroup as per rules in /etc/cgrules.conf */
euid = euid_of_pid(pid);
if (euid == -1) {
fprintf(stderr, "Error in determining euid of"
" pid %d\n", pid);
return -1;
}
egid = egid_of_pid(pid);
if (egid == -1) {
fprintf(stderr, "Error in determining egid of"
" pid %d\n", pid);
return -1;
}
/* Change the cgroup by determining the rules based on uid */
ret = cgroup_change_cgroup_uid_gid(euid, egid, pid);
if (ret) {
fprintf(stderr, "Error: change of cgroup failed for"
" pid %d: %s\n",
pid, cgroup_strerror(ret));
return -1;
}
return 0;
}
int main(int argc, char *argv[])
{
int ret = 0, i, exit_code = 0;
pid_t pid;
int cg_specified = 0;
struct cgroup_group_spec *cgroup_list[CG_HIER_MAX];
int c;
if (argc < 2) {
fprintf(stderr, "usage is %s "
"[-g <list of controllers>:<relative path to cgroup>] "
"<list of pids> \n",
argv[0]);
exit(2);
}
memset(cgroup_list, 0, sizeof(cgroup_list));
while ((c = getopt(argc, argv, "+g:")) > 0) {
switch (c) {
case 'g':
if (parse_cgroup_spec(cgroup_list, optarg)) {
fprintf(stderr, "cgroup controller and path"
"parsing failed\n");
return -1;
}
cg_specified = 1;
break;
default:
fprintf(stderr, "Invalid command line option\n");
exit(2);
break;
}
}
/* Initialize libcg */
ret = cgroup_init();
if (ret) {
fprintf(stderr, "libcgroup initialization failed:%d\n", ret);
return ret;
}
for (i = optind; i < argc; i++) {
pid = (uid_t) atoi(argv[i]);
if (cg_specified)
ret = change_group_path(pid, cgroup_list);
else
ret = change_group_uid_gid(pid);
/* if any group change fails */
if (ret)
exit_code = 1;
}
return exit_code;
}
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