lib/tevent/tevent_fd.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    common events code for fd events
   5
   6    Copyright (C) Stefan Metzmacher 2009
   7
   8      ** NOTE! The following LGPL license applies to the tevent
   9      ** library. This does NOT imply that all of Samba is released
  10      ** under the LGPL
  11
  12    This library is free software; you can redistribute it and/or
  13    modify it under the terms of the GNU Lesser General Public
  14    License as published by the Free Software Foundation; either
  15    version 3 of the License, or (at your option) any later version.
  16
  17    This library is distributed in the hope that it will be useful,
  18    but WITHOUT ANY WARRANTY; without even the implied warranty of
  19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20    Lesser General Public License for more details.
  21
  22    You should have received a copy of the GNU Lesser General Public
  23    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  24 */
  25
  26 #include "replace.h"
  27 #include "tevent.h"
  28 #include "tevent_internal.h"
  29 #include "tevent_util.h"
  30
  31 int tevent_common_fd_destructor(struct tevent_fd *fde)
  32 {
  33         if (fde->destroyed) {
  34                 tevent_common_check_double_free(fde, "tevent_fd double free");
  35                 goto done;
  36         }
  37         fde->destroyed = true;
  38
  39         if (fde->event_ctx) {
  40                 DLIST_REMOVE(fde->event_ctx->fd_events, fde);
  41         }
  42
  43         if (fde->close_fn) {
  44                 fde->close_fn(fde->event_ctx, fde, fde->fd, fde->private_data);
  45                 fde->fd = -1;
  46                 fde->close_fn = NULL;
  47         }
  48
  49         fde->event_ctx = NULL;
  50 done:
  51         if (fde->busy) {
  52                 return -1;
  53         }
  54         fde->wrapper = NULL;
  55
  56         return 0;
  57 }
  58
  59 struct tevent_fd *tevent_common_add_fd(struct tevent_context *ev, TALLOC_CTX *mem_ctx,
  60                                        int fd, uint16_t flags,
  61                                        tevent_fd_handler_t handler,
  62                                        void *private_data,
  63                                        const char *handler_name,
  64                                        const char *location)
  65 {
  66         struct tevent_fd *fde;
  67
  68         /* tevent will crash later on select() if we save
  69          * a negative file descriptor. Better to fail here
  70          * so that consumers will be able to debug it
  71          */
  72         if (fd < 0) return NULL;
  73
  74         fde = talloc(mem_ctx?mem_ctx:ev, struct tevent_fd);
  75         if (!fde) return NULL;
  76
  77         *fde = (struct tevent_fd) {
  78                 .event_ctx      = ev,
  79                 .fd             = fd,
  80                 .flags          = flags,
  81                 .handler        = handler,
  82                 .private_data   = private_data,
  83                 .handler_name   = handler_name,
  84                 .location       = location,
  85         };
  86
  87         DLIST_ADD(ev->fd_events, fde);
  88
  89         talloc_set_destructor(fde, tevent_common_fd_destructor);
  90
  91         return fde;
  92 }
  93 uint16_t tevent_common_fd_get_flags(struct tevent_fd *fde)
  94 {
  95         return fde->flags;
  96 }
  97
  98 void tevent_common_fd_set_flags(struct tevent_fd *fde, uint16_t flags)
  99 {
 100         if (fde->flags == flags) return;
 101         fde->flags = flags;
 102 }
 103
 104 void tevent_common_fd_set_close_fn(struct tevent_fd *fde,
 105                                    tevent_fd_close_fn_t close_fn)
 106 {
 107         fde->close_fn = close_fn;
 108 }
 109
 110 int tevent_common_invoke_fd_handler(struct tevent_fd *fde, uint16_t flags,
 111                                     bool *removed)
 112 {
 113         struct tevent_context *handler_ev = fde->event_ctx;
 114
 115         if (removed != NULL) {
 116                 *removed = false;
 117         }
 118
 119         if (fde->event_ctx == NULL) {
 120                 return 0;
 121         }
 122
 123         fde->busy = true;
 124         if (fde->wrapper != NULL) {
 125                 handler_ev = fde->wrapper->wrap_ev;
 126
 127                 tevent_wrapper_push_use_internal(handler_ev, fde->wrapper);
 128                 fde->wrapper->ops->before_fd_handler(
 129                                         fde->wrapper->wrap_ev,
 130                                         fde->wrapper->private_state,
 131                                         fde->wrapper->main_ev,
 132                                         fde,
 133                                         flags,
 134                                         fde->handler_name,
 135                                         fde->location);
 136         }
 137         fde->handler(handler_ev, fde, flags, fde->private_data);
 138         if (fde->wrapper != NULL) {
 139                 fde->wrapper->ops->after_fd_handler(
 140                                         fde->wrapper->wrap_ev,
 141                                         fde->wrapper->private_state,
 142                                         fde->wrapper->main_ev,
 143                                         fde,
 144                                         flags,
 145                                         fde->handler_name,
 146                                         fde->location);
 147                 tevent_wrapper_pop_use_internal(handler_ev, fde->wrapper);
 148         }
 149         fde->busy = false;
 150
 151         if (fde->destroyed) {
 152                 talloc_set_destructor(fde, NULL);
 153                 TALLOC_FREE(fde);
 154                 if (removed != NULL) {
 155                         *removed = true;
 156                 }
 157         }
 158
 159         return 0;
 160 }