src/shared/nsflags.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright 2016 Lennart Poettering
   4 ***/
   5
   6 #include <sched.h>
   7
   8 #include "alloc-util.h"
   9 #include "extract-word.h"
  10 #include "nsflags.h"
  11 #include "string-util.h"
  12
  13 const struct namespace_flag_map namespace_flag_map[] = {
  14         { CLONE_NEWCGROUP, "cgroup" },
  15         { CLONE_NEWIPC,    "ipc"    },
  16         { CLONE_NEWNET,    "net"    },
  17         /* So, the mount namespace flag is called CLONE_NEWNS for historical reasons. Let's expose it here under a more
  18          * explanatory name: "mnt". This is in-line with how the kernel exposes namespaces in /proc/$PID/ns. */
  19         { CLONE_NEWNS,     "mnt"    },
  20         { CLONE_NEWPID,    "pid"    },
  21         { CLONE_NEWUSER,   "user"   },
  22         { CLONE_NEWUTS,    "uts"    },
  23         {}
  24 };
  25
  26 int namespace_flags_from_string(const char *name, unsigned long *ret) {
  27         unsigned long flags = 0;
  28         int r;
  29
  30         assert_se(ret);
  31
  32         for (;;) {
  33                 _cleanup_free_ char *word = NULL;
  34                 unsigned long f = 0;
  35                 unsigned i;
  36
  37                 r = extract_first_word(&name, &word, NULL, 0);
  38                 if (r < 0)
  39                         return r;
  40                 if (r == 0)
  41                         break;
  42
  43                 for (i = 0; namespace_flag_map[i].name; i++)
  44                         if (streq(word, namespace_flag_map[i].name)) {
  45                                  f = namespace_flag_map[i].flag;
  46                                  break;
  47                         }
  48
  49                 if (f == 0)
  50                         return -EINVAL;
  51
  52                 flags |= f;
  53         }
  54
  55         *ret = flags;
  56         return 0;
  57 }
  58
  59 int namespace_flags_to_string(unsigned long flags, char **ret) {
  60         _cleanup_free_ char *s = NULL;
  61         unsigned i;
  62
  63         for (i = 0; namespace_flag_map[i].name; i++) {
  64                 if ((flags & namespace_flag_map[i].flag) != namespace_flag_map[i].flag)
  65                         continue;
  66
  67                 if (!strextend_with_separator(&s, " ", namespace_flag_map[i].name, NULL))
  68                         return -ENOMEM;
  69         }
  70
  71         if (!s) {
  72                 s = strdup("");
  73                 if (!s)
  74                         return -ENOMEM;
  75         }
  76
  77         *ret = TAKE_PTR(s);
  78
  79         return 0;
  80 }