src/helper/helper-cgroup.c

   1 /*
   2  * Copyright (c) 2016 Samsung Electronics Co., Ltd.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include "helper-cgroup.h"
  18
  19 #define RELEASE_AGENT   "release_agent"
  20 #define NOTIFY_ON_RELEASE  "notify_on_release"
  21
  22 #define CGROUP_FILE_NAME "cgroup.procs"
  23 #define CLASSID_FILE_NAME "net_cls.classid"
  24
  25 #define MAX_PATH_LENGTH 512
  26
  27 static bool cgroup_is_exists(const char *cgroup_full_path)
  28 {
  29         struct stat stat_buf;
  30         return stat(cgroup_full_path, &stat_buf) == 0;
  31 }
  32
  33 static int cgroup_create(const char *cgroup_full_path)
  34 {
  35         if (mkdir(cgroup_full_path,
  36                   S_IRUSR | S_IWUSR | S_IRGRP) < 0)
  37                 return -errno;
  38
  39         return 0;
  40 }
  41
  42 /*
  43  * @desc place pid to cgroup.procs file
  44  * @return 0 in case of success, errno value in case of failure
  45  */
  46 stc_error_e cgroup_write_pid_fullpath(const char *cgroup_full_path,
  47                                       const int pid)
  48 {
  49         int ret;
  50
  51         if (pid <= 0) {
  52                 STC_LOGE("try to write empty pid to %s", cgroup_full_path);
  53                 return STC_ERROR_NO_DATA;
  54         }
  55
  56         ret = cgroup_write_node_uint32(cgroup_full_path, CGROUP_FILE_NAME,
  57                                        (uint32_t)pid);
  58
  59         ret_value_msg_if(ret < 0, STC_ERROR_FAIL,
  60                          "Failed place all pid to cgroup %s", cgroup_full_path);
  61         return STC_ERROR_NONE;
  62 }
  63
  64 stc_error_e cgroup_write_pid(const char *cgroup_subsystem,
  65                              const char *cgroup_name, const int pid)
  66 {
  67         char buf[MAX_PATH_LENGTH];
  68         snprintf(buf, sizeof(buf), "%s/%s", cgroup_subsystem, cgroup_name);
  69         return cgroup_write_pid_fullpath(buf, pid);
  70 }
  71
  72 stc_error_e cgroup_write_pidtree(const char *cgroup_subsystem,
  73                                  const char *cgroup_name, const int pid)
  74 {
  75         char buf[MAX_PATH_LENGTH];
  76
  77         /*/proc/%d/task/%d/children */
  78         char child_buf[21 + MAX_DEC_SIZE(int) + MAX_DEC_SIZE(int)];
  79         char pidbuf[MAX_DEC_SIZE(int)];
  80         stc_error_e ret;
  81
  82         FILE *f;
  83
  84         snprintf(buf, sizeof(buf), "%s/%s", cgroup_subsystem, cgroup_name);
  85         /* place parent */
  86         ret = cgroup_write_pid_fullpath(buf, pid);
  87         ret_value_msg_if(ret != STC_ERROR_NONE, ret,
  88                          "Failed to put parent process %d into %s cgroup",
  89                          pid, cgroup_name);
  90
  91         snprintf(child_buf, sizeof(child_buf), PROC_TASK_CHILDREN,
  92                  pid, pid);
  93         f = fopen(child_buf, "r");
  94         ret_value_msg_if(!f, STC_ERROR_FAIL, "Failed to get child pids!");
  95         while (fgets(pidbuf, sizeof(pidbuf), f) != NULL) {
  96                 int child_pid = atoi(pidbuf);
  97                 if (child_pid < 0) {
  98                         STC_LOGE("Invalid child pid!");
  99                         fclose(f);
 100                         return STC_ERROR_FAIL;
 101                 }
 102                 stc_error_e ret = cgroup_write_pid_fullpath(buf, child_pid);
 103                 if (ret != STC_ERROR_NONE) {
 104                         STC_LOGE("Failed to put parent process %d into %s cgroup",
 105                            pid, cgroup_name);
 106                         fclose(f);
 107                         return ret;
 108                 }
 109         }
 110         fclose(f);
 111         return STC_ERROR_NONE;
 112 }
 113
 114 int cgroup_write_node_uint32(const char *cgroup_name,
 115                              const char *file_name, uint32_t value)
 116 {
 117         char buf[MAX_PATH_LENGTH];
 118         snprintf(buf, sizeof(buf), "%s/%s", cgroup_name, file_name);
 119         STC_LOGD("cgroup_buf %s, value %d\n", buf, value);
 120         return fwrite_uint(buf, value);
 121 }
 122
 123 int cgroup_write_node_str(const char *cgroup_name,
 124                           const char *file_name, const char *string)
 125 {
 126         char buf[MAX_PATH_LENGTH];
 127         snprintf(buf, sizeof(buf), "%s/%s", cgroup_name, file_name);
 128         STC_LOGD("cgroup_buf %s, string %s\n", buf, string);
 129         return fwrite_str(buf, string);
 130 }
 131
 132 int cgroup_read_node_uint32(const char *cgroup_name,
 133                             const char *file_name, uint32_t *value)
 134 {
 135         char buf[MAX_PATH_LENGTH];
 136         int ret;
 137         snprintf(buf, sizeof(buf), "%s/%s", cgroup_name, file_name);
 138         ret = fread_uint(buf, value);
 139         STC_LOGD("cgroup_buf %s, value %d\n", buf, *value);
 140         return ret;
 141 }
 142
 143 int cgroup_make_subdir(const char *parentdir, const char *cgroup_name,
 144                        bool *already)
 145 {
 146         char buf[MAX_PATH_LENGTH];
 147         bool cgroup_exists;
 148         int ret = 0;
 149
 150         if (parentdir)
 151                 ret = snprintf(buf, sizeof(buf), "%s/%s",
 152                                parentdir, cgroup_name);
 153         else
 154                 ret = snprintf(buf, sizeof(buf), "%s",
 155                                cgroup_name);
 156
 157         ret_value_msg_if(ret > sizeof(buf), STC_ERROR_FAIL,
 158                          "Not enought buffer size for %s%s",
 159                          parentdir, cgroup_name);
 160
 161         cgroup_exists = cgroup_is_exists(buf);
 162         if (!cgroup_exists) {
 163                 bool cgroup_remount = false;
 164
 165                 if (parentdir && !strncmp(parentdir, DEFAULT_CGROUP,
 166                                           sizeof(DEFAULT_CGROUP))) {
 167                         ret = mount("tmpfs", DEFAULT_CGROUP, "tmpfs",
 168                                     MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME,
 169                                     "mode=755");
 170                         if (ret < 0) {
 171                                 STC_LOGE("Fail to RW mount cgroup directory. Can't make %s cgroup", cgroup_name);
 172                                 return STC_ERROR_FAIL;
 173                         }
 174                         cgroup_remount = true;
 175                 }
 176
 177                 ret = cgroup_create(buf);
 178                 ret_value_msg_if(ret < 0, STC_ERROR_FAIL,
 179                                  "Fail to create cgroup %s : err %d",
 180                                  cgroup_name, errno);
 181
 182                 if (cgroup_remount) {
 183                         ret = mount("tmpfs", DEFAULT_CGROUP, "tmpfs",
 184                                     MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY,
 185                                     "mode=755");
 186                         if (ret < 0)
 187                                 STC_LOGD("Fail to RO mount");
 188                 }
 189         }
 190
 191         if (already)
 192                 *already = cgroup_exists;
 193
 194         return STC_ERROR_NONE;
 195 }
 196
 197 int cgroup_set_release_agent(const char *cgroup_subsys,
 198                              const char *release_agent)
 199 {
 200         _cleanup_free_ char *buf = NULL;
 201         int r;
 202
 203         r = asprintf(&buf, "%s/%s", DEFAULT_CGROUP, cgroup_subsys);
 204         if (r < 0)
 205                 return -ENOMEM;
 206
 207         r = cgroup_write_node_str(buf, RELEASE_AGENT, release_agent);
 208         if (r < 0)
 209                 return r;
 210
 211         return cgroup_write_node_str(buf, NOTIFY_ON_RELEASE, "1");
 212 }
 213
 214 void cgroup_init(void)
 215 {
 216         /* create stc cgroup directory */
 217         cgroup_make_subdir(CGROUP_NETWORK, STC_CGROUP_NAME, NULL);
 218
 219         /* create background cgroup directory */
 220         cgroup_make_subdir(STC_CGROUP_NETWORK, STC_BACKGROUND_CGROUP_NAME,
 221                            NULL);
 222
 223         cgroup_write_node_uint32(BACKGROUND_CGROUP_NETWORK,
 224                 CLASSID_FILE_NAME, STC_BACKGROUND_APP_CLASSID);
 225
 226         /* create foreground cgroup directory */
 227         cgroup_make_subdir(STC_CGROUP_NETWORK, STC_FOREGROUND_CGROUP_NAME,
 228                            NULL);
 229 }