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 "udev.h"
  31 #include "udev_version.h"
  32 #include "udev_dbus.h"
  33 #include "logging.h"
  34 #include "namedev.h"
  35 #include "udevdb.h"
  36 #include "libsysfs/libsysfs.h"
  37
  38 /* global variables */
  39 char **main_argv;
  40 char **main_envp;
  41 unsigned char logname[42];
  42
  43 static void sig_handler(int signum)
  44 {
  45         dbg("caught signal %d", signum);
  46         switch (signum) {
  47                 case SIGINT:
  48                 case SIGTERM:
  49                         sysbus_disconnect();
  50                         udevdb_exit();
  51                         exit(20 + signum);
  52                         break;
  53                 default:
  54                         dbg("unhandled signal");
  55         }
  56 }
  57
  58 static inline char *get_action(void)
  59 {
  60         char *action;
  61
  62         action = getenv("ACTION");
  63         return action;
  64 }
  65
  66 static inline char *get_devpath(void)
  67 {
  68         char *devpath;
  69
  70         devpath = getenv("DEVPATH");
  71         return devpath;
  72 }
  73
  74 static inline char *get_seqnum(void)
  75 {
  76         char *seqnum;
  77
  78         seqnum = getenv("SEQNUM");
  79         return seqnum;
  80 }
  81
  82 static char *subsystem_blacklist[] = {
  83         "net",
  84         "scsi_host",
  85         "scsi_device",
  86         "usb_host",
  87         "pci_bus",
  88         "",
  89 };
  90
  91 static int udev_hotplug(int argc, char **argv)
  92 {
  93         char *action;
  94         char *devpath;
  95         char *subsystem;
  96         int retval = -EINVAL;
  97         int i;
  98
  99         action = get_action();
 100         if (!action) {
 101                 dbg ("no action?");
 102                 goto exit;
 103         }
 104
 105         devpath = get_devpath();
 106         if (!devpath) {
 107                 dbg ("no devpath?");
 108                 goto exit;
 109         }
 110         dbg("looking at '%s'", devpath);
 111
 112         /* we only care about class devices and block stuff */
 113         if (!strstr(devpath, "class") &&
 114             !strstr(devpath, "block")) {
 115                 dbg("not a block or class device");
 116                 goto exit;
 117         }
 118
 119         /* skip blacklisted subsystems */
 120         subsystem = argv[1];
 121         i = 0;
 122         while (subsystem_blacklist[i][0] != '\0') {
 123                 if (strcmp(subsystem, subsystem_blacklist[i]) == 0) {
 124                         dbg("don't care about '%s' devices", subsystem);
 125                         goto exit;
 126                 }
 127                 i++;
 128         }
 129
 130         /* connect to the system message bus */
 131         sysbus_connect();
 132
 133         /* initialize our configuration */
 134         udev_init_config();
 135
 136         /* initialize udev database */
 137         retval = udevdb_init(UDEVDB_DEFAULT);
 138         if (retval != 0) {
 139                 dbg("unable to initialize database");
 140                 goto exit_sysbus;
 141         }
 142
 143         /* set up a default signal handler for now */
 144         signal(SIGINT, sig_handler);
 145         signal(SIGTERM, sig_handler);
 146
 147         /* initialize the naming deamon */
 148         namedev_init();
 149
 150         if (strcmp(action, "add") == 0)
 151                 retval = udev_add_device(devpath, subsystem);
 152
 153         else if (strcmp(action, "remove") == 0)
 154                 retval = udev_remove_device(devpath, subsystem);
 155
 156         else {
 157                 dbg("unknown action '%s'", action);
 158                 retval = -EINVAL;
 159         }
 160         udevdb_exit();
 161
 162 exit_sysbus:
 163         /* disconnect from the system message bus */
 164         sysbus_disconnect();
 165
 166 exit:
 167         if (retval > 0)
 168                 retval = 0;
 169
 170         return -retval;
 171 }
 172
 173 int main(int argc, char **argv, char **envp)
 174 {
 175         main_argv = argv;
 176         main_envp = envp;
 177
 178         init_logging("udev");
 179         dbg("version %s", UDEV_VERSION);
 180
 181         return udev_hotplug(argc, argv);
 182 }
 183
 184