udev.c

   1 /*
   2  * udev.c
   3  *
   4  * Userspace devfs
   5  *
   6  * Copyright (C) 2003,2004 Greg Kroah-Hartman <greg@kroah.com>
   7  *
   8  *      This program is free software; you can redistribute it and/or modify it
   9  *      under the terms of the GNU General Public License as published by the
  10  *      Free Software Foundation version 2 of the License.
  11  *
  12  *      This program is distributed in the hope that it will be useful, but
  13  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  *      General Public License for more details.
  16  *
  17  *      You should have received a copy of the GNU General Public License along
  18  *      with this program; if not, write to the Free Software Foundation, Inc.,
  19  *      675 Mass Ave, Cambridge, MA 02139, USA.
  20  *
  21  */
  22
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <stdio.h>
  26 #include <errno.h>
  27 #include <ctype.h>
  28 #include <signal.h>
  29
  30 #include "libsysfs/sysfs/libsysfs.h"
  31 #include "udev.h"
  32 #include "udev_version.h"
  33 #include "udev_dbus.h"
  34 #include "logging.h"
  35 #include "namedev.h"
  36 #include "udevdb.h"
  37
  38 /* global variables */
  39 char **main_argv;
  40 char **main_envp;
  41
  42 #ifdef LOG
  43 unsigned char logname[42];
  44 void log_message(int level, const char *format, ...)
  45 {
  46         va_list args;
  47
  48         if (!udev_log)
  49                 return;
  50
  51         va_start(args, format);
  52         vsyslog(level, format, args);
  53         va_end(args);
  54 }
  55 #endif
  56
  57 static void sig_handler(int signum)
  58 {
  59         switch (signum) {
  60                 case SIGINT:
  61                 case SIGTERM:
  62                         sysbus_disconnect();
  63                         udevdb_exit();
  64                         exit(20 + signum);
  65                 default:
  66                         dbg("unhandled signal");
  67         }
  68 }
  69
  70 static char *subsystem_blacklist[] = {
  71         "net",
  72         "scsi_host",
  73         "scsi_device",
  74         "usb_host",
  75         "pci_bus",
  76         "pcmcia_socket",
  77         "",
  78 };
  79
  80 static int udev_hotplug(void)
  81 {
  82         char *action;
  83         char *devpath;
  84         char *subsystem;
  85         int retval = -EINVAL;
  86         int i;
  87         struct sigaction act;
  88
  89         action = get_action();
  90         if (!action) {
  91                 dbg("no action?");
  92                 goto exit;
  93         }
  94
  95         devpath = get_devpath();
  96         if (!devpath) {
  97                 dbg("no devpath?");
  98                 goto exit;
  99         }
 100         dbg("looking at '%s'", devpath);
 101
 102         /* we only care about class devices and block stuff */
 103         if (!strstr(devpath, "class") &&
 104             !strstr(devpath, "block")) {
 105                 dbg("not a block or class device");
 106                 goto exit;
 107         }
 108
 109         /* skip blacklisted subsystems */
 110         subsystem = get_subsystem(main_argv[1]);
 111         if (!subsystem) {
 112                 dbg("no subsystem?");
 113                 goto exit;
 114         }
 115         i = 0;
 116         while (subsystem_blacklist[i][0] != '\0') {
 117                 if (strcmp(subsystem, subsystem_blacklist[i]) == 0) {
 118                         dbg("don't care about '%s' devices", subsystem);
 119                         goto exit;
 120                 }
 121                 i++;
 122         }
 123
 124         /* connect to the system message bus */
 125         sysbus_connect();
 126
 127         /* initialize udev database */
 128         retval = udevdb_init(UDEVDB_DEFAULT);
 129         if (retval != 0) {
 130                 dbg("unable to initialize database");
 131                 goto exit_sysbus;
 132         }
 133
 134         /* set up a default signal handler for now */
 135         act.sa_handler = sig_handler;
 136         sigemptyset (&act.sa_mask);
 137         act.sa_flags = SA_RESTART;
 138         sigaction(SIGINT, &act, NULL);
 139         sigaction(SIGTERM, &act, NULL);
 140
 141         /* initialize the naming deamon */
 142         namedev_init();
 143
 144         if (strcmp(action, "add") == 0)
 145                 retval = udev_add_device(devpath, subsystem, 0);
 146
 147         else if (strcmp(action, "remove") == 0)
 148                 retval = udev_remove_device(devpath, subsystem);
 149
 150         else {
 151                 dbg("unknown action '%s'", action);
 152                 retval = -EINVAL;
 153         }
 154         udevdb_exit();
 155
 156 exit_sysbus:
 157         /* disconnect from the system message bus */
 158         sysbus_disconnect();
 159
 160 exit:
 161         if (retval > 0)
 162                 retval = 0;
 163
 164         return -retval;
 165 }
 166
 167 int main(int argc, char **argv, char **envp)
 168 {
 169         main_argv = argv;
 170         main_envp = envp;
 171
 172         init_logging("udev");
 173
 174         /* initialize our configuration */
 175         udev_init_config();
 176
 177         dbg("version %s", UDEV_VERSION);
 178
 179         return udev_hotplug();
 180 }