src/basic/cap-list.c

/***
  This file is part of systemd.

  Copyright 2014 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <errno.h>
#include <string.h>

#include "alloc-util.h"
#include "capability-util.h"
#include "cap-list.h"
#include "extract-word.h"
#include "macro.h"
#include "missing.h"
#include "parse-util.h"
#include "util.h"

static const struct capability_name* lookup_capability(register const char *str, register GPERF_LEN_TYPE len);

#include "cap-from-name.h"
#include "cap-to-name.h"

const char *capability_to_name(int id) {

        if (id < 0)
                return NULL;

        if (id >= (int) ELEMENTSOF(capability_names))
                return NULL;

        return capability_names[id];
}

int capability_from_name(const char *name) {
        const struct capability_name *sc;
        int r, i;

        assert(name);

        /* Try to parse numeric capability */
        r = safe_atoi(name, &i);
        if (r >= 0 && i >= 0)
                return i;

        /* Try to parse string capability */
        sc = lookup_capability(name, strlen(name));
        if (!sc)
                return -EINVAL;

        return sc->id;
}

int capability_list_length(void) {
        return (int) ELEMENTSOF(capability_names);
}

int capability_set_to_string_alloc(uint64_t set, char **s) {
        _cleanup_free_ char *str = NULL;
        unsigned long i;
        size_t allocated = 0, n = 0;

        assert(s);

        for (i = 0; i < cap_last_cap(); i++)
                if (set & (UINT64_C(1) << i)) {
                        const char *p;
                        size_t add;

                        p = capability_to_name(i);
                        if (!p)
                                return -EINVAL;

                        add = strlen(p);

                        if (!GREEDY_REALLOC(str, allocated, n + add + 2))
                                return -ENOMEM;

                        strcpy(mempcpy(str + n, p, add), " ");
                        n += add + 1;
                }

        if (!GREEDY_REALLOC(str, allocated, n + 1))
                return -ENOMEM;

        str[n > 0 ? n - 1 : 0] = '\0'; /* truncate the last space, if it's there */

        *s = str;
        str = NULL;

        return 0;
}

int capability_set_from_string(const char *s, uint64_t *set) {
        uint64_t val = 0;
        const char *p;

        assert(set);

        for (p = s;;) {
                _cleanup_free_ char *word = NULL;
                int r;

                r = extract_first_word(&p, &word, NULL, EXTRACT_QUOTES);
                if (r == -ENOMEM)
                        return r;
                if (r <= 0)
                        break;

                r = capability_from_name(word);
                if (r < 0)
                        continue;

                val |= ((uint64_t) UINT64_C(1)) << (uint64_t) r;
        }

        *set = val;

        return 0;
}