io/label.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2018 Red Hat, Inc. All Rights Reserved.
   4  */
   5
   6 #include <sys/ioctl.h>
   7 #include "platform_defs.h"
   8 #include "libxfs.h"
   9 #include "path.h"
  10 #include "command.h"
  11 #include "init.h"
  12 #include "io.h"
  13
  14 #ifndef FS_IOC_GETFSLABEL
  15 /* Max chars for the interface; fs limits may differ */
  16 #define FSLABEL_MAX 256
  17 #define FS_IOC_GETFSLABEL               _IOR(0x94, 49, char[FSLABEL_MAX])
  18 #define FS_IOC_SETFSLABEL               _IOW(0x94, 50, char[FSLABEL_MAX])
  19 #endif
  20
  21 static cmdinfo_t label_cmd;
  22
  23 static void
  24 label_help(void)
  25 {
  26         printf(_(
  27 "\n"
  28 " Manipulate or query the filesystem label while mounted.\n"
  29 "\n"
  30 " With no arguments, displays the current filesystem label.\n"
  31 " -s newlabel -- set the filesystem label to newlabel\n"
  32 " -c          -- clear the filesystem label (sets to NULL string)\n"
  33 "\n"));
  34 }
  35
  36 static int
  37 label_f(
  38         int             argc,
  39         char            **argv)
  40 {
  41         int             c;
  42         int             error;
  43         char            label[FSLABEL_MAX + 1];
  44
  45         if (argc == 1) {
  46                 memset(label, 0, sizeof(label));
  47                 error = ioctl(file->fd, FS_IOC_GETFSLABEL, &label);
  48                 goto out;
  49         }
  50
  51         while ((c = getopt(argc, argv, "cs:")) != EOF) {
  52                 switch (c) {
  53                 case 'c':
  54                         label[0] = '\0';
  55                         break;
  56                 case 's':
  57                         if (strlen(optarg) > FSLABEL_MAX) {
  58                                 errno = EINVAL;
  59                                 error = 1;
  60                                 goto out;
  61                         }
  62                         strncpy(label, optarg, sizeof(label) - 1);
  63                         label[sizeof(label) - 1] = 0;
  64                         break;
  65                 default:
  66                         return command_usage(&label_cmd);
  67                 }
  68         }
  69
  70         /* Check for trailing arguments */
  71         if (argc != optind)
  72                 return command_usage(&label_cmd);
  73
  74         error = ioctl(file->fd, FS_IOC_SETFSLABEL, label);
  75 out:
  76         if (error) {
  77                 perror("label");
  78                 exitcode = 1;
  79         } else {
  80                 printf("label = \"%s\"\n", label);
  81         }
  82
  83         return 0;
  84 }
  85
  86 void
  87 label_init(void)
  88 {
  89         label_cmd.name = "label";
  90         label_cmd.cfunc = label_f;
  91         label_cmd.argmin = 0;
  92         label_cmd.argmax = 3;
  93         label_cmd.args = _("[-s label|-c]");
  94         label_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
  95         label_cmd.oneline =
  96                 _("query, set, or clear the filesystem label while mounted");
  97         label_cmd.help = label_help;
  98
  99         add_command(&label_cmd);
 100 }