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"

/*
 * getgroups(2)
 *
 */
ssize_t alcove_sys_getgroups(alcove_state_t *ap, const char *arg, size_t len,
                             char *reply, size_t rlen) {
  int rindex = 0;
  int size = 0;
  int n = 0;
  gid_t *list = NULL;
  int errnum = 0;

  UNUSED(ap);
  UNUSED(arg);
  UNUSED(len);

  size = getgroups(0, NULL);
  if (size < 0)
    return alcove_mk_errno(reply, rlen, errno);

  list = calloc(size, sizeof(gid_t));
  if (list == NULL)
    return alcove_mk_errno(reply, rlen, errno);

  n = getgroups(size, list);

  if (n < 0) {
    errnum = errno;
    free(list);
    return alcove_mk_errno(reply, rlen, errnum);
  }

  ALCOVE_ERR(alcove_encode_version(reply, rlen, &rindex));
  ALCOVE_ERR(alcove_encode_tuple_header(reply, rlen, &rindex, 2));
  ALCOVE_ERR(alcove_encode_atom(reply, rlen, &rindex, "ok"));

  n--;
  for (; n >= 0; n--) {
    ALCOVE_ERR(alcove_encode_list_header(reply, rlen, &rindex, 1));
    ALCOVE_ERR(alcove_encode_long(reply, rlen, &rindex, list[n]));
  }

  ALCOVE_ERR(alcove_encode_empty_list(reply, rlen, &rindex));

  free(list);

  return rindex;
}