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
  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 inline char *get_action(void)
  71 {
  72         char *action;
  73
  74         action = getenv("ACTION");
  75         return action;
  76 }
  77
  78 static inline char *get_devpath(void)
  79 {
  80         char *devpath;
  81
  82         devpath = getenv("DEVPATH");
  83         return devpath;
  84 }
  85
  86 static inline char *get_seqnum(void)
  87 {
  88         char *seqnum;
  89
  90         seqnum = getenv("SEQNUM");
  91         return seqnum;
  92 }
  93
  94 static char *subsystem_blacklist[] = {
  95         "net",
  96         "scsi_host",
  97         "scsi_device",
  98         "usb_host",
  99         "pci_bus",
 100         "",
 101 };
 102
 103 static int udev_hotplug(int argc, char **argv)
 104 {
 105         char *action;
 106         char *devpath;
 107         char *subsystem;
 108         int retval = -EINVAL;
 109         int i;
 110         struct sigaction act;
 111
 112         action = get_action();
 113         if (!action) {
 114                 dbg ("no action?");
 115                 goto exit;
 116         }
 117
 118         devpath = get_devpath();
 119         if (!devpath) {
 120                 dbg ("no devpath?");
 121                 goto exit;
 122         }
 123         dbg("looking at '%s'", devpath);
 124
 125         /* we only care about class devices and block stuff */
 126         if (!strstr(devpath, "class") &&
 127             !strstr(devpath, "block")) {
 128                 dbg("not a block or class device");
 129                 goto exit;
 130         }
 131
 132         /* skip blacklisted subsystems */
 133         subsystem = argv[1];
 134         i = 0;
 135         while (subsystem_blacklist[i][0] != '\0') {
 136                 if (strcmp(subsystem, subsystem_blacklist[i]) == 0) {
 137                         dbg("don't care about '%s' devices", subsystem);
 138                         goto exit;
 139                 }
 140                 i++;
 141         }
 142
 143         /* connect to the system message bus */
 144         sysbus_connect();
 145
 146         /* initialize our configuration */
 147         udev_init_config();
 148
 149         /* initialize udev database */
 150         retval = udevdb_init(UDEVDB_DEFAULT);
 151         if (retval != 0) {
 152                 dbg("unable to initialize database");
 153                 goto exit_sysbus;
 154         }
 155
 156         /* set up a default signal handler for now */
 157         act.sa_handler = sig_handler;
 158         sigemptyset (&act.sa_mask);
 159         act.sa_flags = SA_RESTART;
 160         sigaction(SIGINT, &act, NULL);
 161         sigaction(SIGTERM, &act, NULL);
 162
 163         /* initialize the naming deamon */
 164         namedev_init();
 165
 166         if (strcmp(action, "add") == 0)
 167                 retval = udev_add_device(devpath, subsystem, 0);
 168
 169         else if (strcmp(action, "remove") == 0)
 170                 retval = udev_remove_device(devpath, subsystem);
 171
 172         else {
 173                 dbg("unknown action '%s'", action);
 174                 retval = -EINVAL;
 175         }
 176         udevdb_exit();
 177
 178 exit_sysbus:
 179         /* disconnect from the system message bus */
 180         sysbus_disconnect();
 181
 182 exit:
 183         if (retval > 0)
 184                 retval = 0;
 185
 186         return -retval;
 187 }
 188
 189 int main(int argc, char **argv, char **envp)
 190 {
 191         main_argv = argv;
 192         main_envp = envp;
 193
 194         init_logging("udev");
 195         dbg("version %s", UDEV_VERSION);
 196
 197         return udev_hotplug(argc, argv);
 198 }
 199
 200