src/basic/cap-list.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4 #include <string.h>
   5
   6 #include "alloc-util.h"
   7 #include "capability-util.h"
   8 #include "cap-list.h"
   9 #include "extract-word.h"
  10 #include "macro.h"
  11 #include "parse-util.h"
  12 #include "stdio-util.h"
  13 #include "util.h"
  14
  15 static const struct capability_name* lookup_capability(register const char *str, register GPERF_LEN_TYPE len);
  16
  17 #include "cap-from-name.h"
  18 #include "cap-to-name.h"
  19
  20 const char *capability_to_name(int id) {
  21         if (id < 0)
  22                 return NULL;
  23
  24         if ((size_t) id >= ELEMENTSOF(capability_names))
  25                 return NULL;
  26
  27         return capability_names[id];
  28 }
  29
  30 int capability_from_name(const char *name) {
  31         const struct capability_name *sc;
  32         int r, i;
  33
  34         assert(name);
  35
  36         /* Try to parse numeric capability */
  37         r = safe_atoi(name, &i);
  38         if (r >= 0) {
  39                 if (i >= 0 && i < 64)
  40                         return i;
  41                 else
  42                         return -EINVAL;
  43         }
  44
  45         /* Try to parse string capability */
  46         sc = lookup_capability(name, strlen(name));
  47         if (!sc)
  48                 return -EINVAL;
  49
  50         return sc->id;
  51 }
  52
  53 /* This is the number of capability names we are *compiled* with.
  54  * For the max capability number of the currently-running kernel,
  55  * use cap_last_cap(). */
  56 int capability_list_length(void) {
  57         return (int) ELEMENTSOF(capability_names);
  58 }
  59
  60 int capability_set_to_string_alloc(uint64_t set, char **s) {
  61         _cleanup_free_ char *str = NULL;
  62         size_t n = 0;
  63
  64         assert(s);
  65
  66         for (unsigned i = 0; i <= cap_last_cap(); i++)
  67                 if (set & (UINT64_C(1) << i)) {
  68                         const char *p;
  69                         char buf[2 + 16 + 1];
  70                         size_t add;
  71
  72                         p = capability_to_name(i);
  73                         if (!p) {
  74                                 xsprintf(buf, "0x%x", i);
  75                                 p = buf;
  76                         }
  77
  78                         add = strlen(p);
  79
  80                         if (!GREEDY_REALLOC(str, n + add + 2))
  81                                 return -ENOMEM;
  82
  83                         strcpy(mempcpy(str + n, p, add), " ");
  84                         n += add + 1;
  85                 }
  86
  87         if (!GREEDY_REALLOC(str, n + 1))
  88                 return -ENOMEM;
  89
  90         str[n > 0 ? n - 1 : 0] = '\0'; /* truncate the last space, if it's there */
  91
  92         *s = TAKE_PTR(str);
  93
  94         return 0;
  95 }
  96
  97 int capability_set_from_string(const char *s, uint64_t *set) {
  98         uint64_t val = 0;
  99
 100         assert(set);
 101
 102         for (const char *p = s;;) {
 103                 _cleanup_free_ char *word = NULL;
 104                 int r;
 105
 106                 r = extract_first_word(&p, &word, NULL, EXTRACT_UNQUOTE);
 107                 if (r == -ENOMEM)
 108                         return r;
 109                 if (r <= 0)
 110                         break;
 111
 112                 r = capability_from_name(word);
 113                 if (r < 0)
 114                         continue;
 115
 116                 val |= ((uint64_t) UINT64_C(1)) << (uint64_t) r;
 117         }
 118
 119         *set = val;
 120
 121         return 0;
 122 }