[5930] | 1 | /* |
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| 2 | module_block.c |
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| 3 | |
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| 4 | Creates block device nodes using hotplug environment variables. |
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| 5 | |
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| 6 | Copyright (C) 2007 Andreas Oberritter |
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| 7 | Copyright (C) 2005 Greg Kroah-Hartman <greg@kroah.com> |
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| 8 | |
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| 9 | This program is free software; you can redistribute it and/or modify |
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| 10 | it under the terms of the GNU General Public License 2.0 as published by |
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| 11 | the Free Software Foundation. |
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| 12 | |
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| 13 | This program is distributed in the hope that it will be useful, |
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| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 16 | GNU General Public License for more details. |
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| 17 | |
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| 18 | You should have received a copy of the GNU General Public License along |
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| 19 | with this program; if not, write to the Free Software Foundation, Inc., |
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| 20 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
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| 21 | */ |
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| 22 | |
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| 23 | #define _GNU_SOURCE /* for getline() */ |
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| 24 | #include <errno.h> |
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| 25 | #include <fcntl.h> |
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| 26 | #include <libgen.h> |
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| 27 | #include <signal.h> |
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| 28 | #include <stdbool.h> |
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| 29 | #include <stdio.h> |
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| 30 | #include <stdlib.h> |
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| 31 | #include <sys/stat.h> |
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| 32 | #include <sys/wait.h> |
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| 33 | #include "hotplug_basename.h" |
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| 34 | #include "hotplug_devpath.h" |
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| 35 | #include "hotplug_pidfile.h" |
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| 36 | #include "hotplug_setenv.h" |
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| 37 | #include "hotplug_socket.h" |
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| 38 | #include "hotplug_timeout.h" |
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| 39 | #include "module_block.h" |
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| 40 | #include "udev.h" |
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| 41 | |
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| 42 | static const char *block_vars[] = { |
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| 43 | "ACTION", |
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| 44 | "DEVPATH", |
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| 45 | "PHYSDEVPATH", |
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| 46 | "PHYSDEVDRIVER", |
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| 47 | "X_E2_REMOVABLE", |
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| 48 | "X_E2_CDROM", |
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| 49 | NULL, |
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| 50 | }; |
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| 51 | |
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| 52 | static int bdpoll_exec(const char devpath[], bool is_cdrom, bool support_media_changed) |
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| 53 | { |
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| 54 | pid_t pid; |
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| 55 | char *argv[5]; |
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| 56 | unsigned int i = 0; |
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| 57 | |
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| 58 | pid = fork(); |
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| 59 | if (pid == -1) { |
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| 60 | perror("fork"); |
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| 61 | return -1; |
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| 62 | } else if (pid == 0) { |
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| 63 | argv[i++] = "bdpoll"; |
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| 64 | argv[i++] = (char *)devpath; |
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| 65 | if (is_cdrom) |
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| 66 | argv[i++] = "-c"; |
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| 67 | if (support_media_changed) |
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| 68 | argv[i++] = "-m"; |
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| 69 | argv[i++] = NULL; |
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| 70 | if (execvp(argv[0], argv) == -1) |
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| 71 | perror(argv[0]); |
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| 72 | return -1; |
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| 73 | } else { |
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| 74 | return pidfile_write(pid, "bdpoll.%s", hotplug_basename(devpath)); |
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| 75 | } |
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| 76 | } |
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| 77 | |
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| 78 | static int bdpoll_kill(const char devpath[]) |
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| 79 | { |
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| 80 | struct timeout t; |
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| 81 | pid_t pid, wpid; |
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| 82 | |
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| 83 | if (pidfile_read(&pid, "bdpoll.%s", hotplug_basename(devpath)) == -1) |
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| 84 | return -1; |
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| 85 | |
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| 86 | if (kill(pid, SIGTERM) == -1) { |
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| 87 | perror("kill"); |
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| 88 | return -1; |
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| 89 | } |
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| 90 | |
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| 91 | timeout_init(&t, 1000); |
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| 92 | do { |
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| 93 | wpid = waitpid(pid, NULL, WNOHANG); |
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| 94 | if (wpid == -1) { |
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| 95 | perror("waitpid"); |
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| 96 | return -1; |
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| 97 | } |
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| 98 | if (wpid > 0) |
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| 99 | goto exit; |
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| 100 | } while (!timeout_exceeded(&t)); |
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| 101 | |
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| 102 | if (kill(pid, SIGKILL) == -1) { |
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| 103 | perror("kill"); |
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| 104 | return -1; |
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| 105 | } |
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| 106 | |
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| 107 | exit: |
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| 108 | pidfile_unlink("bdpoll.%s", hotplug_basename(devpath)); |
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| 109 | return 0; |
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| 110 | } |
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| 111 | |
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| 112 | static int do_mknod(const char *devnode, const char *major, const char *minor) |
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| 113 | { |
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| 114 | dev_t dev = (atoi(major) << 8) | atoi(minor); |
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| 115 | |
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| 116 | return mknod(devnode, S_IFBLK | S_IRUSR | S_IWUSR, dev); |
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| 117 | } |
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| 118 | |
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| 119 | static long sysfs_attr_get_long(const char *devpath, const char *attr_name) |
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| 120 | { |
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| 121 | char *value; |
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| 122 | |
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| 123 | value = sysfs_attr_get_value(devpath, attr_name); |
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| 124 | if (value == NULL) { |
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| 125 | errno = ERANGE; |
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| 126 | return LONG_MAX; |
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| 127 | } |
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| 128 | |
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| 129 | errno = 0; |
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| 130 | return strtol(value, NULL, 0); |
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| 131 | } |
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| 132 | |
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| 133 | #define GENHD_FL_REMOVABLE 1 |
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| 134 | static bool dev_is_removable(const char *devpath) |
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| 135 | { |
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| 136 | long attr; |
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| 137 | |
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| 138 | attr = sysfs_attr_get_long(devpath, "removable"); |
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| 139 | if ((attr != LONG_MAX) || (errno != ERANGE)) |
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| 140 | return (attr != 0); |
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| 141 | |
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| 142 | attr = sysfs_attr_get_long(devpath, "capability"); |
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| 143 | if ((attr != LONG_MAX) || (errno != ERANGE)) |
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| 144 | return (attr & GENHD_FL_REMOVABLE); |
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| 145 | |
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| 146 | return false; |
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| 147 | } |
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| 148 | |
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| 149 | #define GENHD_FL_MEDIA_CHANGE_NOTIFY 4 |
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| 150 | static bool dev_can_notify_media_change(const char *devpath) |
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| 151 | { |
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| 152 | long attr; |
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| 153 | |
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| 154 | attr = sysfs_attr_get_long(devpath, "capability"); |
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| 155 | if ((attr != LONG_MAX) || (errno != ERANGE)) |
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| 156 | return (attr & GENHD_FL_MEDIA_CHANGE_NOTIFY); |
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| 157 | |
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| 158 | return false; |
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| 159 | } |
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| 160 | |
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| 161 | #define GENHD_FL_CD 8 |
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| 162 | static bool dev_is_cdrom(const char *devpath) |
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| 163 | { |
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| 164 | char pathname[FILENAME_MAX]; |
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| 165 | bool ret = false; |
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| 166 | const char *str; |
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| 167 | char *buf = NULL; |
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| 168 | size_t n = 0; |
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| 169 | long attr; |
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| 170 | FILE *f; |
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| 171 | |
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| 172 | attr = sysfs_attr_get_long(devpath, "capability"); |
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| 173 | if ((attr != LONG_MAX) || (errno != ERANGE)) |
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| 174 | return (attr & GENHD_FL_CD); |
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| 175 | |
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| 176 | str = hotplug_basename(devpath); |
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| 177 | |
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| 178 | if (!strncmp(str, "sr", 2)) |
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| 179 | return 1; |
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| 180 | |
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| 181 | if ((strlen(str) > 2) && |
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| 182 | (str[0] == 'h') && |
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| 183 | (str[1] == 'd')) { |
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| 184 | snprintf(pathname, sizeof(pathname), "/proc/ide/%s/media", str); |
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| 185 | |
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| 186 | f = fopen(pathname, "r"); |
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| 187 | if (f == NULL) { |
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| 188 | dbg("can't open %s: %s", pathname, strerror(errno)); |
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| 189 | } else { |
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| 190 | if (getline(&buf, &n, f) != -1) { |
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| 191 | if (buf != NULL) { |
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| 192 | if (n >= 5) |
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| 193 | ret = !strncmp(buf, "cdrom", 5); |
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| 194 | free(buf); |
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| 195 | } |
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| 196 | } |
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| 197 | fclose(f); |
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| 198 | } |
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| 199 | } |
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| 200 | |
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| 201 | return ret; |
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| 202 | } |
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| 203 | |
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| 204 | int block_add(void) |
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| 205 | { |
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| 206 | char *devpath; |
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| 207 | const char *minor, *major; |
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| 208 | char devnode[FILENAME_MAX]; |
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| 209 | bool is_removable; |
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| 210 | bool is_cdrom; |
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| 211 | bool support_media_changed; |
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| 212 | |
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| 213 | sysfs_init(); |
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| 214 | |
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| 215 | /* |
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| 216 | * DEVPATH=/block/sda |
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| 217 | * DEVPATH=/block/sda/sda1 |
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| 218 | */ |
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| 219 | devpath = getenv("DEVPATH"); |
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| 220 | if (!devpath) { |
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| 221 | dbg("missing DEVPATH environment variable, aborting."); |
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| 222 | return EXIT_FAILURE; |
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| 223 | } |
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| 224 | |
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| 225 | minor = getenv("MINOR"); |
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| 226 | if (!minor) { |
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| 227 | dbg("missing MINOR environment variable, aborting."); |
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| 228 | return EXIT_FAILURE; |
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| 229 | } |
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| 230 | |
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| 231 | major = getenv("MAJOR"); |
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| 232 | if (!major) { |
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| 233 | dbg("missing MAJOR environment variable, aborting."); |
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| 234 | return EXIT_FAILURE; |
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| 235 | } |
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| 236 | |
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| 237 | if (!hotplug_devpath_to_devnode(devpath, devnode, sizeof(devnode))) { |
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| 238 | dbg("could not get device node."); |
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| 239 | return EXIT_FAILURE; |
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| 240 | } |
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| 241 | |
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| 242 | unlink(devnode); |
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| 243 | |
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| 244 | if (do_mknod(devnode, major, minor) == -1) { |
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| 245 | dbg("mknod: %s", strerror(errno)); |
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| 246 | return EXIT_FAILURE; |
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| 247 | } |
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| 248 | |
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| 249 | is_removable = dev_is_removable(devpath); |
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| 250 | is_cdrom = is_removable && dev_is_cdrom(devpath); |
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| 251 | support_media_changed = is_cdrom && dev_can_notify_media_change(devpath); |
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| 252 | |
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| 253 | if (is_removable) { |
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| 254 | if (bdpoll_exec(devpath, is_cdrom, support_media_changed) == -1) |
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| 255 | dbg("could not exec bdpoll"); |
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| 256 | } |
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| 257 | |
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| 258 | hotplug_setenv_bool("X_E2_REMOVABLE", is_removable); |
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| 259 | hotplug_setenv_bool("X_E2_CDROM", is_cdrom); |
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| 260 | |
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| 261 | system("/sbin/hotplug.sh"); |
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| 262 | hotplug_socket_send_env(block_vars); |
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| 263 | |
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| 264 | return EXIT_SUCCESS; |
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| 265 | } |
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| 266 | |
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| 267 | int block_remove(void) |
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| 268 | { |
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| 269 | char *devpath; |
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| 270 | char devnode[FILENAME_MAX]; |
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| 271 | |
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| 272 | devpath = getenv("DEVPATH"); |
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| 273 | if (!devpath) { |
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| 274 | dbg("missing DEVPATH environment variable, aborting."); |
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| 275 | return EXIT_FAILURE; |
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| 276 | } |
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| 277 | |
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| 278 | if (!hotplug_devpath_to_devnode(devpath, devnode, sizeof(devnode))) { |
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| 279 | dbg("could not get device node."); |
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| 280 | return EXIT_FAILURE; |
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| 281 | } |
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| 282 | |
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| 283 | unlink(devnode); |
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| 284 | |
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| 285 | if (bdpoll_kill(devpath) == -1) |
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| 286 | dbg("could not kill bdpoll"); |
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| 287 | |
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| 288 | system("/sbin/hotplug.sh"); |
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| 289 | hotplug_socket_send_env(block_vars); |
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| 290 | |
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| 291 | return EXIT_SUCCESS; |
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| 292 | } |
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| 293 | |
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