src/shared/nsflags.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <sched.h>
   4
   5 #include "alloc-util.h"
   6 #include "extract-word.h"
   7 #include "nsflags.h"
   8 #include "string-util.h"
   9
  10 const struct namespace_flag_map namespace_flag_map[] = {
  11         { CLONE_NEWCGROUP, "cgroup" },
  12         { CLONE_NEWIPC,    "ipc"    },
  13         { CLONE_NEWNET,    "net"    },
  14         /* So, the mount namespace flag is called CLONE_NEWNS for historical reasons. Let's expose it here under a more
  15          * explanatory name: "mnt". This is in-line with how the kernel exposes namespaces in /proc/$PID/ns. */
  16         { CLONE_NEWNS,     "mnt"    },
  17         { CLONE_NEWPID,    "pid"    },
  18         { CLONE_NEWUSER,   "user"   },
  19         { CLONE_NEWUTS,    "uts"    },
  20         {}
  21 };
  22
  23 int namespace_flags_from_string(const char *name, unsigned long *ret) {
  24         unsigned long flags = 0;
  25         int r;
  26
  27         assert_se(ret);
  28
  29         for (;;) {
  30                 _cleanup_free_ char *word = NULL;
  31                 unsigned long f = 0;
  32                 unsigned i;
  33
  34                 r = extract_first_word(&name, &word, NULL, 0);
  35                 if (r < 0)
  36                         return r;
  37                 if (r == 0)
  38                         break;
  39
  40                 for (i = 0; namespace_flag_map[i].name; i++)
  41                         if (streq(word, namespace_flag_map[i].name)) {
  42                                  f = namespace_flag_map[i].flag;
  43                                  break;
  44                         }
  45
  46                 if (f == 0)
  47                         return -EINVAL;
  48
  49                 flags |= f;
  50         }
  51
  52         *ret = flags;
  53         return 0;
  54 }
  55
  56 int namespace_flags_to_string(unsigned long flags, char **ret) {
  57         _cleanup_free_ char *s = NULL;
  58         unsigned i;
  59
  60         for (i = 0; namespace_flag_map[i].name; i++) {
  61                 if ((flags & namespace_flag_map[i].flag) != namespace_flag_map[i].flag)
  62                         continue;
  63
  64                 if (!strextend_with_separator(&s, " ", namespace_flag_map[i].name, NULL))
  65                         return -ENOMEM;
  66         }
  67
  68         if (!s) {
  69                 s = strdup("");
  70                 if (!s)
  71                         return -ENOMEM;
  72         }
  73
  74         *ret = TAKE_PTR(s);
  75
  76         return 0;
  77 }