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 asmlinkage 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 %d", signum);
  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 int main(int argc, char *argv[], char *envp[])
  80 {
  81         main_argv = argv;
  82         main_envp = envp;
  83         struct sigaction act;
  84         char *action;
  85         char *devpath = "";
  86         char *subsystem = "";
  87         int i;
  88         int retval = -EINVAL;
  89         enum {
  90                 ADD,
  91                 REMOVE,
  92                 UDEVSTART,
  93         } act_type;
  94
  95         dbg("version %s", UDEV_VERSION);
  96
  97         /* initialize our configuration */
  98         udev_init_config();
  99
 100         if (strstr(argv[0], "udevstart")) {
 101                 act_type = UDEVSTART;
 102         } else {
 103                 action = get_action();
 104                 if (!action) {
 105                         dbg("no action?");
 106                         goto exit;
 107                 }
 108                 if (strcmp(action, "add") == 0) {
 109                         act_type = ADD;
 110                 } else if (strcmp(action, "remove") == 0) {
 111                         act_type = REMOVE;
 112                 } else {
 113                         dbg("unknown action '%s'", action);
 114                         goto exit;
 115                 }
 116
 117                 devpath = get_devpath();
 118                 if (!devpath) {
 119                         dbg("no devpath?");
 120                         goto exit;
 121                 }
 122                 dbg("looking at '%s'", devpath);
 123
 124                 /* we only care about class devices and block stuff */
 125                 if (!strstr(devpath, "class") && !strstr(devpath, "block")) {
 126                         dbg("not a block or class device");
 127                         goto exit;
 128                 }
 129
 130                 subsystem = get_subsystem(main_argv[1]);
 131                 if (!subsystem) {
 132                         dbg("no subsystem?");
 133                         goto exit;
 134                 }
 135
 136                 /* skip blacklisted subsystems */
 137                 i = 0;
 138                 while (subsystem_blacklist[i][0] != '\0') {
 139                         if (strcmp(subsystem, subsystem_blacklist[i]) == 0) {
 140                                 dbg("don't care about '%s' devices", subsystem);
 141                                 goto exit;
 142                         }
 143                         i++;
 144                 }
 145         }
 146
 147         /* set signal handlers */
 148         act.sa_handler = sig_handler;
 149         sigemptyset (&act.sa_mask);
 150         act.sa_flags = SA_RESTART;
 151         sigaction(SIGINT, &act, NULL);
 152         sigaction(SIGTERM, &act, NULL);
 153
 154         /* initialize udev database */
 155         if (udevdb_init(UDEVDB_DEFAULT) != 0) {
 156                 dbg("unable to initialize database");
 157                 goto exit;
 158         }
 159
 160         switch(act_type) {
 161         case UDEVSTART:
 162                 dbg("udevstart");
 163                 namedev_init();
 164                 udev_sleep = 0;
 165                 retval = udev_start();
 166                 break;
 167         case ADD:
 168                 dbg("udev add");
 169                 namedev_init();
 170                 retval = udev_add_device(devpath, subsystem, NOFAKE);
 171                 break;
 172         case REMOVE:
 173                 dbg("udev remove");
 174                 retval = udev_remove_device(devpath, subsystem);
 175         }
 176
 177         udevdb_exit();
 178
 179 exit:
 180         return retval;
 181 }