udevsend.c

   1 /*
   2  * udevsend.c
   3  *
   4  * Userspace devfs
   5  *
   6  * Copyright (C) 2004 Ling, Xiaofeng <xiaofeng.ling@intel.com>
   7  * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
   8  *
   9  *
  10  *      This program is free software; you can redistribute it and/or modify it
  11  *      under the terms of the GNU General Public License as published by the
  12  *      Free Software Foundation version 2 of the License.
  13  *
  14  *      This program is distributed in the hope that it will be useful, but
  15  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *      General Public License for more details.
  18  *
  19  *      You should have received a copy of the GNU General Public License along
  20  *      with this program; if not, write to the Free Software Foundation, Inc.,
  21  *      675 Mass Ave, Cambridge, MA 02139, USA.
  22  *
  23  */
  24
  25 #include <sys/types.h>
  26 #include <sys/ipc.h>
  27 #include <sys/msg.h>
  28 #include <errno.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32
  33 #include "udev.h"
  34 #include "udevd.h"
  35 #include "logging.h"
  36
  37 static inline char *get_action(void)
  38 {
  39         char *action;
  40
  41         action = getenv("ACTION");
  42         return action;
  43 }
  44
  45 static inline char *get_devpath(void)
  46 {
  47         char *devpath;
  48
  49         devpath = getenv("DEVPATH");
  50         return devpath;
  51 }
  52
  53 static inline char *get_seqnum(void)
  54 {
  55         char *seqnum;
  56
  57         seqnum = getenv("SEQNUM");
  58         return seqnum;
  59 }
  60
  61 static int build_hotplugmsg(struct hotplug_msg **ppmsg, char *action,
  62                             char *devpath, char *subsystem, int seqnum)
  63 {
  64         struct hotplug_msg *pmsg;
  65
  66         pmsg = malloc(sizeof(struct hotplug_msg));
  67         pmsg->mtype = HOTPLUGMSGTYPE;
  68         pmsg->seqnum = seqnum;
  69         strncpy(pmsg->action, action, 8);
  70         strncpy(pmsg->devpath, devpath, 128);
  71         strncpy(pmsg->subsystem, subsystem, 16);
  72         *ppmsg = pmsg;
  73         return sizeof(struct hotplug_msg);
  74 }
  75
  76 static void free_hotplugmsg(struct hotplug_msg *pmsg)
  77 {
  78         free(pmsg);
  79 }
  80
  81 int main(int argc, char* argv[])
  82 {
  83         int msgid;
  84         key_t key;
  85         struct msqid_ds  msg_queue;
  86         struct msgbuf *pmsg;
  87         char *action;
  88         char *devpath;
  89         char *subsystem;
  90         char *seqnum;
  91         int seq;
  92         int retval = -EINVAL;
  93         int size;
  94
  95         subsystem = argv[1];
  96         if (subsystem == NULL) {
  97                 dbg("no subsystem");
  98                 goto exit;
  99         }
 100
 101         devpath = get_devpath();
 102         if (devpath == NULL) {
 103                 dbg("no devpath");
 104                 goto exit;
 105         }
 106
 107         action = get_action();
 108         if (action == NULL) {
 109                 dbg("no action");
 110                 goto exit;
 111         }
 112
 113         seqnum = get_seqnum();
 114         if (seqnum == NULL) {
 115                 dbg("no seqnum");
 116                 goto exit;
 117         }
 118         seq = atoi(seqnum);
 119
 120         key = ftok(DEFAULT_EXEC_PROGRAM, IPC_KEY_ID);
 121         size =  build_hotplugmsg( (struct hotplug_msg**) &pmsg, action, devpath, subsystem, seq);
 122         msgid = msgget(key, IPC_CREAT);
 123         if (msgid == -1) {
 124                 dbg("open ipc queue error");
 125                 goto exit;
 126         }
 127
 128         /* get state of queue */
 129         retval = msgctl(msgid, IPC_STAT, &msg_queue);
 130         if (retval == -1) {
 131                 dbg("error getting info on ipc queue");
 132                 goto exit;
 133         }
 134         if (msg_queue.msg_qnum > 0)
 135                 dbg("%li messages already in the ipc queue", msg_queue.msg_qnum);
 136
 137         retval = msgsnd(msgid, pmsg, size, 0);
 138         free_hotplugmsg( (struct hotplug_msg*) pmsg);
 139         if (retval == -1) {
 140                 dbg("send ipc message error");
 141                 goto exit;
 142         }
 143         return 0;
 144
 145 exit:
 146         if (retval > 0)
 147                 retval = 0;
 148
 149         return retval;
 150 }