dabbad/ipc.c

   1 /* __LICENSE_HEADER_BEGIN__ */
   2
   3 /*
   4  * Copyright (C) 2012   Emmanuel Roullit <emmanuel.roullit@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or (at
   9  * your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  14  * for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
  19  *
  20  */
  21
  22 /* __LICENSE_HEADER_END__ */
  23
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <errno.h>
  27 #include <assert.h>
  28 #include <dabbad/ipc.h>
  29 #include <dabbad/list.h>
  30 #include <dabbad/capture.h>
  31
  32 static int dabbad_handle_msg(struct dabba_ipc_msg *msg)
  33 {
  34         int rc;
  35         assert(msg);
  36
  37         switch (msg->msg_body.type) {
  38         case DABBA_IFCONF:
  39                 rc = dabbad_ifconf_get(msg);
  40                 break;
  41         case DABBA_CAPTURE_START:
  42                 rc = dabbad_capture_start(msg);
  43                 break;
  44         case DABBA_CAPTURE_LIST:
  45                 rc = dabbad_capture_list(msg);
  46                 break;
  47         case DABBA_CAPTURE_STOP:
  48                 rc = dabbad_capture_stop(msg);
  49                 break;
  50         default:
  51                 rc = -1;
  52                 errno = ENOSYS;
  53                 break;
  54         }
  55
  56         return rc;
  57 }
  58
  59 int dabbad_ipc_msg_init(void)
  60 {
  61         return msgctl(dabba_get_ipc_queue_id(0), IPC_RMID, NULL);
  62 }
  63
  64 void dabbad_ipc_msg_flush(int qid)
  65 {
  66         struct dabba_ipc_msg msg;
  67         ssize_t rcv;
  68
  69         do {
  70                 rcv =
  71                     msgrcv(qid, &msg, sizeof(msg.msg_body), 0,
  72                            IPC_NOWAIT | MSG_NOERROR);
  73         } while (rcv > 0);
  74 }
  75
  76 int dabbad_ipc_msg_poll(void)
  77 {
  78         int qid;
  79         ssize_t rcv;
  80         int snd;
  81         struct dabba_ipc_msg msg;
  82
  83         qid = dabba_get_ipc_queue_id(IPC_CREAT | IPC_EXCL | 0660);
  84
  85         if (qid < 0) {
  86                 perror("Cannot get IPC id");
  87                 return errno;
  88         }
  89
  90         dabbad_ipc_msg_flush(qid);
  91
  92         for (;;) {
  93                 memset(&msg, 0, sizeof(msg));
  94                 rcv = msgrcv(qid, &msg, sizeof(msg.msg_body), 0, 0);
  95
  96                 if (rcv <= 0) {
  97                         perror("Error while receiving IPC msg");
  98                         return errno;
  99                 }
 100
 101                 rcv = dabbad_handle_msg(&msg);
 102
 103                 msg.msg_body.error = rcv;
 104
 105                 if (rcv != 0) {
 106                         perror("Error while handling IPC msg");
 107                 }
 108
 109                 snd = msgsnd(qid, &msg, sizeof(msg.msg_body), 0);
 110
 111                 if (snd < 0) {
 112                         perror("Error while sending back IPC msg");
 113                         return errno;
 114                 }
 115         }
 116
 117         return 0;
 118 }