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 <stdio.h>
  24 #include <stddef.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <ctype.h>
  28 #include <errno.h>
  29 #include <signal.h>
  30
  31 #include "libsysfs/sysfs/libsysfs.h"
  32 #include "udev.h"
  33 #include "udev_lib.h"
  34 #include "udev_version.h"
  35 #include "udev_dbus.h"
  36 #include "logging.h"
  37 #include "namedev.h"
  38 #include "udevdb.h"
  39
  40 /* global variables */
  41 char **main_argv;
  42 char **main_envp;
  43
  44 #ifdef LOG
  45 unsigned char logname[LOGNAME_SIZE];
  46 void log_message(int level, const char *format, ...)
  47 {
  48         va_list args;
  49
  50         if (!udev_log)
  51                 return;
  52
  53         va_start(args, format);
  54         vsyslog(level, format, args);
  55         va_end(args);
  56 }
  57 #endif
  58
  59 static void sig_handler(int signum)
  60 {
  61         switch (signum) {
  62                 case SIGINT:
  63                 case SIGTERM:
  64                         sysbus_disconnect();
  65                         udevdb_exit();
  66                         exit(20 + signum);
  67                 default:
  68                         dbg("unhandled signal");
  69         }
  70 }
  71
  72 static char *subsystem_blacklist[] = {
  73         "net",
  74         "scsi_host",
  75         "scsi_device",
  76         "usb_host",
  77         "pci_bus",
  78         "pcmcia_socket",
  79         ""
  80 };
  81
  82 static int udev_hotplug(void)
  83 {
  84         char *action;
  85         char *devpath;
  86         char *subsystem;
  87         int retval = -EINVAL;
  88         int i;
  89         struct sigaction act;
  90
  91         action = get_action();
  92         if (!action) {
  93                 dbg("no action?");
  94                 goto exit;
  95         }
  96
  97         devpath = get_devpath();
  98         if (!devpath) {
  99                 dbg("no devpath?");
 100                 goto exit;
 101         }
 102         dbg("looking at '%s'", devpath);
 103
 104         /* we only care about class devices and block stuff */
 105         if (!strstr(devpath, "class") &&
 106             !strstr(devpath, "block")) {
 107                 dbg("not a block or class device");
 108                 goto exit;
 109         }
 110
 111         /* skip blacklisted subsystems */
 112         subsystem = get_subsystem(main_argv[1]);
 113         if (!subsystem) {
 114                 dbg("no subsystem?");
 115                 goto exit;
 116         }
 117         i = 0;
 118         while (subsystem_blacklist[i][0] != '\0') {
 119                 if (strcmp(subsystem, subsystem_blacklist[i]) == 0) {
 120                         dbg("don't care about '%s' devices", subsystem);
 121                         goto exit;
 122                 }
 123                 i++;
 124         }
 125
 126         /* connect to the system message bus */
 127         sysbus_connect();
 128
 129         /* initialize udev database */
 130         retval = udevdb_init(UDEVDB_DEFAULT);
 131         if (retval != 0) {
 132                 dbg("unable to initialize database");
 133                 goto exit_sysbus;
 134         }
 135
 136         /* set up a default signal handler for now */
 137         act.sa_handler = sig_handler;
 138         sigemptyset (&act.sa_mask);
 139         act.sa_flags = SA_RESTART;
 140         sigaction(SIGINT, &act, NULL);
 141         sigaction(SIGTERM, &act, NULL);
 142
 143         /* initialize the naming deamon */
 144         namedev_init();
 145
 146         if (strcmp(action, "add") == 0)
 147                 retval = udev_add_device(devpath, subsystem, 0);
 148
 149         else if (strcmp(action, "remove") == 0)
 150                 retval = udev_remove_device(devpath, subsystem);
 151
 152         else {
 153                 dbg("unknown action '%s'", action);
 154                 retval = -EINVAL;
 155         }
 156         udevdb_exit();
 157
 158 exit_sysbus:
 159         /* disconnect from the system message bus */
 160         sysbus_disconnect();
 161
 162 exit:
 163         if (retval > 0)
 164                 retval = 0;
 165
 166         return -retval;
 167 }
 168
 169 int main(int argc, char *argv[], char *envp[])
 170 {
 171         main_argv = argv;
 172         main_envp = envp;
 173
 174         init_logging("udev");
 175
 176         /* initialize our configuration */
 177         udev_init_config();
 178
 179         dbg("version %s", UDEV_VERSION);
 180
 181         return udev_hotplug();
 182 }