src/cgroups/cgroup.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include "config.h"
   4
   5 #include <dirent.h>
   6 #include <errno.h>
   7 #include <fcntl.h>
   8 #include <inttypes.h>
   9 #include <linux/magic.h>
  10 #include <linux/sched.h>
  11 #include <sched.h>
  12 #include <stdarg.h>
  13 #include <stdbool.h>
  14 #include <stdint.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <sys/epoll.h>
  19 #include <sys/mount.h>
  20 #include <sys/stat.h>
  21 #include <sys/types.h>
  22 #include <sys/vfs.h>
  23 #include <unistd.h>
  24
  25 #include "../macro.h"
  26 #include "../memory_utils.h"
  27 #include "cgroup.h"
  28 #include "cgroup_utils.h"
  29 #include "cgroup2_devices.h"
  30
  31 extern struct cgroup_ops *cgfsng_ops_init(void);
  32
  33 struct cgroup_ops *cgroup_init(void)
  34 {
  35         struct cgroup_ops *ops;
  36
  37         ops = cgfsng_ops_init();
  38         if (!ops)
  39                 return log_error_errno(NULL, errno, "Failed to initialize cgroup driver");
  40
  41         return ops;
  42 }
  43
  44 void cgroup_exit(struct cgroup_ops *ops)
  45 {
  46         if (!ops)
  47                 return;
  48
  49         for (struct hierarchy **it = ops->hierarchies; it && *it; it++) {
  50                 for (char **p = (*it)->controllers; p && *p; p++)
  51                         free(*p);
  52                 free((*it)->controllers);
  53                 free((*it)->__controllers);
  54
  55                 if ((*it)->fd >= 0)
  56                         close((*it)->fd);
  57
  58                 free((*it)->mountpoint);
  59                 free((*it)->base_path);
  60                 free(*it);
  61         }
  62
  63         if (ops->mntns_fd >= 0)
  64                 close(ops->mntns_fd);
  65
  66         if (ops->cgroup2_root_fd >= 0)
  67                 close(ops->cgroup2_root_fd);
  68
  69         free(ops->hierarchies);
  70
  71         free(ops);
  72
  73         return;
  74 }
  75
  76 #define INIT_SCOPE "/init.scope"
  77 void prune_init_scope(char *cg)
  78 {
  79         char *point;
  80
  81         if (!cg)
  82                 return;
  83
  84         point = cg + strlen(cg) - strlen(INIT_SCOPE);
  85         if (point < cg)
  86                 return;
  87
  88         if (strcmp(point, INIT_SCOPE) == 0) {
  89                 if (point == cg)
  90                         *(point + 1) = '\0';
  91                 else
  92                         *point = '\0';
  93         }
  94 }
  95
  96 char *get_pid_cgroup(pid_t pid, const char *contrl)
  97 {
  98         int cfd;
  99
 100         cfd = get_cgroup_fd(contrl);
 101         if (cfd < 0)
 102                 return NULL;
 103
 104         if (pure_unified_layout(cgroup_ops))
 105                 return cg_unified_get_current_cgroup(pid);
 106
 107         return cg_legacy_get_current_cgroup(pid, contrl);
 108 }
 109
 110 /*
 111  * Read the cpuset.cpus for cg
 112  * Return the answer in a newly allocated string which must be freed
 113  */
 114 char *get_cpuset(const char *cg)
 115 {
 116         char *value = NULL;
 117         int ret;
 118
 119         ret = cgroup_ops->get_cpuset_cpus(cgroup_ops, cg, &value);
 120         if (ret < 0)
 121                 return NULL;
 122
 123         return value;
 124 }