src/basic/cap-list.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2014 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <string.h>
  22
  23 #include "alloc-util.h"
  24 #include "capability-util.h"
  25 #include "cap-list.h"
  26 #include "extract-word.h"
  27 #include "macro.h"
  28 #include "missing.h"
  29 #include "parse-util.h"
  30 #include "util.h"
  31
  32 static const struct capability_name* lookup_capability(register const char *str, register GPERF_LEN_TYPE len);
  33
  34 #include "cap-from-name.h"
  35 #include "cap-to-name.h"
  36
  37 const char *capability_to_name(int id) {
  38
  39         if (id < 0)
  40                 return NULL;
  41
  42         if (id >= (int) ELEMENTSOF(capability_names))
  43                 return NULL;
  44
  45         return capability_names[id];
  46 }
  47
  48 int capability_from_name(const char *name) {
  49         const struct capability_name *sc;
  50         int r, i;
  51
  52         assert(name);
  53
  54         /* Try to parse numeric capability */
  55         r = safe_atoi(name, &i);
  56         if (r >= 0 && i >= 0)
  57                 return i;
  58
  59         /* Try to parse string capability */
  60         sc = lookup_capability(name, strlen(name));
  61         if (!sc)
  62                 return -EINVAL;
  63
  64         return sc->id;
  65 }
  66
  67 int capability_list_length(void) {
  68         return (int) ELEMENTSOF(capability_names);
  69 }
  70
  71 int capability_set_to_string_alloc(uint64_t set, char **s) {
  72         _cleanup_free_ char *str = NULL;
  73         unsigned long i;
  74         size_t allocated = 0, n = 0;
  75
  76         assert(s);
  77
  78         for (i = 0; i < cap_last_cap(); i++)
  79                 if (set & (UINT64_C(1) << i)) {
  80                         const char *p;
  81                         size_t add;
  82
  83                         p = capability_to_name(i);
  84                         if (!p)
  85                                 return -EINVAL;
  86
  87                         add = strlen(p);
  88
  89                         if (!GREEDY_REALLOC0(str, allocated, n + add + 2))
  90                                 return -ENOMEM;
  91
  92                         strcpy(mempcpy(str + n, p, add), " ");
  93                         n += add + 1;
  94                 }
  95
  96         if (n != 0)
  97                 str[n - 1] = '\0';
  98
  99         *s = str;
 100         str = NULL;
 101
 102         return 0;
 103 }
 104
 105 int capability_set_from_string(const char *s, uint64_t *set) {
 106         uint64_t val = 0;
 107         const char *p;
 108
 109         assert(set);
 110
 111         for (p = s;;) {
 112                 _cleanup_free_ char *word = NULL;
 113                 int r;
 114
 115                 r = extract_first_word(&p, &word, NULL, EXTRACT_QUOTES);
 116                 if (r == -ENOMEM)
 117                         return r;
 118                 if (r <= 0)
 119                         break;
 120
 121                 r = capability_from_name(word);
 122                 if (r < 0)
 123                         continue;
 124
 125                 val |= ((uint64_t) UINT64_C(1)) << (uint64_t) r;
 126         }
 127
 128         *set = val;
 129
 130         return 0;
 131 }