alcove

/* Copyright (c) 2015, Michael Santos <michael.santos@gmail.com>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#include "alcove.h"
#include "alcove_call.h"

#if defined(__FreeBSD__)
#include <sys/capsicum.h>
#include "alcove_cap_constants.h"

static int alcove_decode_cap_rights_list(const char *buf, size_t len,
        int *index, cap_rights_t *rights,
        const alcove_constant_t *constants);
#endif

/*
 * cap_rights_limit(2)
 *
 */
    ssize_t
alcove_sys_cap_rights_limit(alcove_state_t *ap, const char *arg, size_t len,
        char *reply, size_t rlen)
{
#if defined(__FreeBSD__)
    int index = 0;
    int rv = 0;

    int fd = -1;
    cap_rights_t rights;

    UNUSED(ap);

    (void)cap_rights_init(&rights);

    /* fd */
    if (alcove_decode_int(arg, len, &index, &fd) < 0)
        return -1;

    /* rights */
    switch (alcove_decode_cap_rights_list(arg, len, &index, &rights,
                alcove_cap_constants)) {
        case 0:
            break;
        case 1:
            return alcove_mk_error(reply, rlen, "enotsup");
        default:
            return -1;
    }


    rv = cap_rights_limit(fd, &rights);

    return (rv < 0)
        ? alcove_mk_errno(reply, rlen, errno)
        : alcove_mk_atom(reply, rlen, "ok");
#else
    UNUSED(ap);
    UNUSED(arg);
    UNUSED(len);

    return alcove_mk_atom(reply, rlen, "undef");
#endif
}

#if defined(__FreeBSD__)
    static int
alcove_decode_cap_rights_list(const char *buf, size_t len, int *index,
        cap_rights_t *rights, const alcove_constant_t *constants)
{
    int type = 0;
    int arity = 0;

    if (alcove_get_type(buf, len, index, &type, &arity) < 0)
        return -1;

    switch (type) {
        case ERL_NIL_EXT:
            if (ei_decode_list_header(buf, index, &arity) < 0)
                return -1;
            break;

        case ERL_SMALL_INTEGER_EXT:
        case ERL_INTEGER_EXT: {
            int val = 0;

            if (alcove_decode_int(buf, len, index, &val) < 0)
                return -1;

            (void)cap_rights_set(rights, val);
            }
            break;

        case ERL_STRING_EXT: {
            char tmp[MAXMSGLEN] = {0};
            char *p = tmp;

            if (arity >= sizeof(tmp))
                return -1;

            if (ei_decode_string(buf, index, tmp) < 0)
                return -1;

            for ( ; *p; p++)
                (void)cap_rights_set(rights, *p);

            }
            break;

        case ERL_LIST_EXT: {
            int i = 0;
            int length = 0;
            uint64_t constant = 0;
            long long val = 0;
            int rv = 0;

            if (ei_decode_list_header(buf, index, &length) < 0)
                return -1;

            for (i = 0; i < length; i++) {
                rv = alcove_decode_constant64(buf, len, index,
                        &val, constants);

                if (rv != 0)
                    return rv;

                if (val < 0 || val > INT64_MAX)
                    return -1;

                constant = val;

                (void)cap_rights_set(rights, constant);
            }

            /* [] */
            if (alcove_decode_list_header(buf, len, index, &length) < 0
                    || length != 0)
                return -1;

            }
            break;

        default:
            return -1;
    }

    return 0;
}
#endif