LXR busybox/networking/isrv.h

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * Generic non-forking server infrastructure.
   4 * Intended to make writing telnetd-type servers easier.
   5 *
   6 * Copyright (C) 2007 Denys Vlasenko
   7 *
   8 * Licensed under GPLv2, see file LICENSE in this source tree.
   9 */
  10
  11PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
  12
  13/* opaque structure */
  14struct isrv_state_t;
  15typedef struct isrv_state_t isrv_state_t;
  16
  17/* callbacks */
  18void isrv_want_rd(isrv_state_t *state, int fd);
  19void isrv_want_wr(isrv_state_t *state, int fd);
  20void isrv_dont_want_rd(isrv_state_t *state, int fd);
  21void isrv_dont_want_wr(isrv_state_t *state, int fd);
  22int isrv_register_fd(isrv_state_t *state, int peer, int fd);
  23void isrv_close_fd(isrv_state_t *state, int fd);
  24int isrv_register_peer(isrv_state_t *state, void *param);
  25
  26/* Driver:
  27 *
  28 * Select on listen_fd for <linger_timeout> (or forever if 0).
  29 *
  30 * If we time out and we have no peers, exit.
  31 * If we have peers, call do_timeout(peer_param),
  32 * if it returns !0, peer is removed.
  33 *
  34 * If listen_fd is active, accept new connection ("peer"),
  35 * call new_peer() on it, and if it returns 0,
  36 * add it to fds to select on.
  37 * Now, select will wait for <timeout>, not <linger_timeout>
  38 * (as long as we have more than zero peers).
  39 *
  40 * If a peer's fd is active, we call do_rd() on it if read
  41 * bit was set, and then do_wr() if write bit was also set.
  42 * If either returns !0, peer is removed.
  43 * Reaching this place also resets timeout counter for this peer.
  44 *
  45 * Note that peer must indicate that he wants to be selected
  46 * for read and/or write using isrv_want_rd()/isrv_want_wr()
  47 * [can be called in new_peer() or in do_rd()/do_wr()].
  48 * If it never wants to be selected for write, do_wr()
  49 * will never be called (can be NULL).
  50 */
  51void isrv_run(
  52        int listen_fd,
  53        int (*new_peer)(isrv_state_t *state, int fd),
  54        int (*do_rd)(int fd, void **),
  55        int (*do_wr)(int fd, void **),
  56        int (*do_timeout)(void **),
  57        int timeout,
  58        int linger_timeout
  59);
  60
  61POP_SAVED_FUNCTION_VISIBILITY
  62