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 "logging.h"
  36 #include "namedev.h"
  37 #include "udevdb.h"
  38
  39 /* global variables */
  40 char **main_argv;
  41 char **main_envp;
  42
  43 #ifdef LOG
  44 unsigned char logname[LOGNAME_SIZE];
  45 void log_message(int level, const char *format, ...)
  46 {
  47         va_list args;
  48
  49         if (!udev_log)
  50                 return;
  51
  52         va_start(args, format);
  53         vsyslog(level, format, args);
  54         va_end(args);
  55 }
  56 #endif
  57
  58 static void sig_handler(int signum)
  59 {
  60         switch (signum) {
  61                 case SIGINT:
  62                 case SIGTERM:
  63                         udevdb_exit();
  64                         exit(20 + signum);
  65                 default:
  66                         dbg("unhandled signal");
  67         }
  68 }
  69
  70 static char *subsystem_blacklist[] = {
  71         "scsi_host",
  72         "scsi_device",
  73         "usb_host",
  74         "pci_bus",
  75         "pcmcia_socket",
  76         ""
  77 };
  78
  79 static int udev_hotplug(void)
  80 {
  81         char *action;
  82         char *devpath;
  83         char *subsystem;
  84         int retval = -EINVAL;
  85         int i;
  86         struct sigaction act;
  87         const int nofake = 0;
  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         /* initialize udev database */
 125         retval = udevdb_init(UDEVDB_DEFAULT);
 126         if (retval != 0) {
 127                 dbg("unable to initialize database");
 128                 goto exit;
 129         }
 130
 131         /* set up a default signal handler for now */
 132         act.sa_handler = sig_handler;
 133         sigemptyset (&act.sa_mask);
 134         act.sa_flags = SA_RESTART;
 135         sigaction(SIGINT, &act, NULL);
 136         sigaction(SIGTERM, &act, NULL);
 137
 138         if (strcmp(action, "add") == 0) {
 139                 namedev_init();
 140                 retval = udev_add_device(devpath, subsystem, nofake);
 141                 goto action_done;
 142         }
 143
 144         if (strcmp(action, "remove") == 0) {
 145                 retval = udev_remove_device(devpath, subsystem);
 146                 goto action_done;
 147         }
 148
 149         dbg("unknown action '%s'", action);
 150         retval = -EINVAL;
 151
 152 action_done:
 153         udevdb_exit();
 154
 155 exit:
 156         return retval;
 157 }
 158
 159 int main(int argc, char *argv[], char *envp[])
 160 {
 161         main_argv = argv;
 162         main_envp = envp;
 163
 164         init_logging("udev");
 165
 166         /* initialize our configuration */
 167         udev_init_config();
 168
 169         dbg("version %s", UDEV_VERSION);
 170
 171         return udev_hotplug();
 172 }