[3320] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * mdev - Mini udev for busybox
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| 4 | *
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| 5 | * Copyright 2005 Rob Landley <rob@landley.net>
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| 6 | * Copyright 2005 Frank Sorenson <frank@tuxrocks.com>
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| 7 | *
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| 8 | * Licensed under GPLv2, see file LICENSE in this source tree.
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| 9 | */
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| 10 | #include "libbb.h"
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| 11 | #include "xregex.h"
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| 12 |
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| 13 | /* "mdev -s" scans /sys/class/xxx, looking for directories which have dev
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| 14 | * file (it is of the form "M:m\n"). Example: /sys/class/tty/tty0/dev
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| 15 | * contains "4:0\n". Directory name is taken as device name, path component
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| 16 | * directly after /sys/class/ as subsystem. In this example, "tty0" and "tty".
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| 17 | * Then mdev creates the /dev/device_name node.
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| 18 | * If /sys/class/.../dev file does not exist, mdev still may act
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| 19 | * on this device: see "@|$|*command args..." parameter in config file.
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| 20 | *
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| 21 | * mdev w/o parameters is called as hotplug helper. It takes device
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| 22 | * and subsystem names from $DEVPATH and $SUBSYSTEM, extracts
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| 23 | * maj,min from "/sys/$DEVPATH/dev" and also examines
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| 24 | * $ACTION ("add"/"delete") and $FIRMWARE.
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| 25 | *
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| 26 | * If action is "add", mdev creates /dev/device_name similarly to mdev -s.
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| 27 | * (todo: explain "delete" and $FIRMWARE)
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| 28 | *
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| 29 | * If /etc/mdev.conf exists, it may modify /dev/device_name's properties.
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| 30 | * /etc/mdev.conf file format:
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| 31 | *
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| 32 | * [-][subsystem/]device user:grp mode [>|=path] [@|$|*command args...]
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| 33 | * [-]@maj,min[-min2] user:grp mode [>|=path] [@|$|*command args...]
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| 34 | * [-]$envvar=val user:grp mode [>|=path] [@|$|*command args...]
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| 35 | *
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| 36 | * Leading minus in 1st field means "don't stop on this line", otherwise
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| 37 | * search is stopped after the matching line is encountered.
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| 38 | *
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| 39 | * The device name or "subsystem/device" combo is matched against 1st field
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| 40 | * (which is a regex), or maj,min is matched against 1st field,
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| 41 | * or specified environment variable (as regex) is matched against 1st field.
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| 42 | *
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| 43 | * $envvar=val format is useful for loading modules for hot-plugged devices
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| 44 | * which do not have driver loaded yet. In this case /sys/class/.../dev
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| 45 | * does not exist, but $MODALIAS is set to needed module's name
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| 46 | * (actually, an alias to it) by kernel. This rule instructs mdev
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| 47 | * to load the module and exit:
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| 48 | * $MODALIAS=.* 0:0 660 @modprobe "$MODALIAS"
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| 49 | * The kernel will generate another hotplug event when /sys/class/.../dev
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| 50 | * file appears.
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| 51 | *
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| 52 | * When line matches, the device node is created, chmod'ed and chown'ed,
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| 53 | * moved to path, and if >path, a symlink to moved node is created,
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| 54 | * all this if /sys/class/.../dev exists.
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| 55 | * Examples:
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| 56 | * =loop/ - moves to /dev/loop
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| 57 | * >disk/sda%1 - moves to /dev/disk/sdaN, makes /dev/sdaN a symlink
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| 58 | *
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| 59 | * Then "command args..." is executed (via sh -c 'command args...').
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| 60 | * @:execute on creation, $:on deletion, *:on both.
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| 61 | * This happens regardless of /sys/class/.../dev existence.
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| 62 | */
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| 63 |
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| 64 | struct globals {
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| 65 | int root_major, root_minor;
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| 66 | char *subsystem;
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| 67 | } FIX_ALIASING;
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| 68 | #define G (*(struct globals*)&bb_common_bufsiz1)
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| 69 |
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| 70 | /* Prevent infinite loops in /sys symlinks */
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| 71 | #define MAX_SYSFS_DEPTH 3
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| 72 |
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| 73 | /* We use additional 64+ bytes in make_device() */
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| 74 | #define SCRATCH_SIZE 80
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| 75 |
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| 76 | /* Builds an alias path.
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| 77 | * This function potentionally reallocates the alias parameter.
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| 78 | * Only used for ENABLE_FEATURE_MDEV_RENAME
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| 79 | */
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| 80 | static char *build_alias(char *alias, const char *device_name)
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| 81 | {
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| 82 | char *dest;
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| 83 |
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| 84 | /* ">bar/": rename to bar/device_name */
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| 85 | /* ">bar[/]baz": rename to bar[/]baz */
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| 86 | dest = strrchr(alias, '/');
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| 87 | if (dest) { /* ">bar/[baz]" ? */
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| 88 | *dest = '\0'; /* mkdir bar */
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| 89 | bb_make_directory(alias, 0755, FILEUTILS_RECUR);
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| 90 | *dest = '/';
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| 91 | if (dest[1] == '\0') { /* ">bar/" => ">bar/device_name" */
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| 92 | dest = alias;
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| 93 | alias = concat_path_file(alias, device_name);
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| 94 | free(dest);
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| 95 | }
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| 96 | }
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| 97 |
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| 98 | return alias;
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| 99 | }
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| 100 |
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| 101 | /* mknod in /dev based on a path like "/sys/block/hda/hda1"
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| 102 | * NB1: path parameter needs to have SCRATCH_SIZE scratch bytes
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| 103 | * after NUL, but we promise to not mangle (IOW: to restore if needed)
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| 104 | * path string.
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| 105 | * NB2: "mdev -s" may call us many times, do not leak memory/fds!
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| 106 | */
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| 107 | static void make_device(char *path, int delete)
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| 108 | {
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| 109 | char *device_name, *subsystem_slash_devname;
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| 110 | int major, minor, type, len;
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| 111 | mode_t mode;
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| 112 | parser_t *parser;
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| 113 |
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| 114 | /* Try to read major/minor string. Note that the kernel puts \n after
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| 115 | * the data, so we don't need to worry about null terminating the string
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| 116 | * because sscanf() will stop at the first nondigit, which \n is.
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| 117 | * We also depend on path having writeable space after it.
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| 118 | */
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| 119 | major = -1;
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| 120 | if (!delete) {
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| 121 | char *dev_maj_min = path + strlen(path);
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| 122 |
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| 123 | strcpy(dev_maj_min, "/dev");
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| 124 | len = open_read_close(path, dev_maj_min + 1, 64);
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| 125 | *dev_maj_min = '\0';
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| 126 | if (len < 1) {
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| 127 | if (!ENABLE_FEATURE_MDEV_EXEC)
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| 128 | return;
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| 129 | /* no "dev" file, but we can still run scripts
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| 130 | * based on device name */
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| 131 | } else if (sscanf(++dev_maj_min, "%u:%u", &major, &minor) != 2) {
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| 132 | major = -1;
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| 133 | }
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| 134 | }
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| 135 | /* else: for delete, -1 still deletes the node, but < -1 suppresses that */
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| 136 |
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| 137 | /* Determine device name, type, major and minor */
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| 138 | device_name = (char*) bb_basename(path);
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| 139 | /* http://kernel.org/doc/pending/hotplug.txt says that only
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| 140 | * "/sys/block/..." is for block devices. "/sys/bus" etc is not.
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| 141 | * But since 2.6.25 block devices are also in /sys/class/block.
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| 142 | * We use strstr("/block/") to forestall future surprises. */
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| 143 | type = S_IFCHR;
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| 144 | if (strstr(path, "/block/") || (G.subsystem && strncmp(G.subsystem, "block", 5) == 0))
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| 145 | type = S_IFBLK;
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| 146 |
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| 147 | /* Make path point to "subsystem/device_name" */
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| 148 | subsystem_slash_devname = NULL;
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| 149 | /* Check for coldplug invocations first */
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| 150 | if (strncmp(path, "/sys/block/", 11) == 0) /* legacy case */
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| 151 | path += sizeof("/sys/") - 1;
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| 152 | else if (strncmp(path, "/sys/class/", 11) == 0)
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| 153 | path += sizeof("/sys/class/") - 1;
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| 154 | else {
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| 155 | /* Example of a hotplug invocation:
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| 156 | * SUBSYSTEM="block"
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| 157 | * DEVPATH="/sys" + "/devices/virtual/mtd/mtd3/mtdblock3"
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| 158 | * ("/sys" is added by mdev_main)
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| 159 | * - path does not contain subsystem
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| 160 | */
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| 161 | subsystem_slash_devname = concat_path_file(G.subsystem, device_name);
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| 162 | path = subsystem_slash_devname;
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| 163 | }
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| 164 |
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| 165 | /* If we have config file, look up user settings */
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| 166 | if (ENABLE_FEATURE_MDEV_CONF)
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| 167 | parser = config_open2("/etc/mdev.conf", fopen_for_read);
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| 168 |
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| 169 | do {
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| 170 | int keep_matching;
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| 171 | struct bb_uidgid_t ugid;
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| 172 | char *tokens[4];
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| 173 | char *command = NULL;
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| 174 | char *alias = NULL;
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| 175 | char aliaslink = aliaslink; /* for compiler */
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| 176 |
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| 177 | /* Defaults in case we won't match any line */
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| 178 | ugid.uid = ugid.gid = 0;
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| 179 | keep_matching = 0;
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| 180 | mode = 0660;
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| 181 |
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| 182 | if (ENABLE_FEATURE_MDEV_CONF
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| 183 | && config_read(parser, tokens, 4, 3, "# \t", PARSE_NORMAL)
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| 184 | ) {
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| 185 | char *val;
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| 186 | char *str_to_match;
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| 187 | regmatch_t off[1 + 9 * ENABLE_FEATURE_MDEV_RENAME_REGEXP];
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| 188 |
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| 189 | val = tokens[0];
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| 190 | keep_matching = ('-' == val[0]);
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| 191 | val += keep_matching; /* swallow leading dash */
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| 192 |
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| 193 | /* Match against either "subsystem/device_name"
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| 194 | * or "device_name" alone */
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| 195 | str_to_match = strchr(val, '/') ? path : device_name;
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| 196 |
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| 197 | /* Fields: regex uid:gid mode [alias] [cmd] */
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| 198 |
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| 199 | if (val[0] == '@') {
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| 200 | /* @major,minor[-minor2] */
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| 201 | /* (useful when name is ambiguous:
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| 202 | * "/sys/class/usb/lp0" and
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| 203 | * "/sys/class/printer/lp0") */
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| 204 | int cmaj, cmin0, cmin1, sc;
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| 205 | if (major < 0)
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| 206 | continue; /* no dev, no match */
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| 207 | sc = sscanf(val, "@%u,%u-%u", &cmaj, &cmin0, &cmin1);
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| 208 | if (sc < 1
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| 209 | || major != cmaj
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| 210 | || (sc == 2 && minor != cmin0)
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| 211 | || (sc == 3 && (minor < cmin0 || minor > cmin1))
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| 212 | ) {
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| 213 | continue; /* this line doesn't match */
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| 214 | }
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| 215 | goto line_matches;
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| 216 | }
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| 217 | if (val[0] == '$') {
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| 218 | /* regex to match an environment variable */
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| 219 | char *eq = strchr(++val, '=');
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| 220 | if (!eq)
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| 221 | continue;
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| 222 | *eq = '\0';
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| 223 | str_to_match = getenv(val);
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| 224 | if (!str_to_match)
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| 225 | continue;
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| 226 | str_to_match -= strlen(val) + 1;
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| 227 | *eq = '=';
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| 228 | }
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| 229 | /* else: regex to match [subsystem/]device_name */
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| 230 |
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| 231 | {
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| 232 | regex_t match;
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| 233 | int result;
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| 234 |
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| 235 | xregcomp(&match, val, REG_EXTENDED);
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| 236 | result = regexec(&match, str_to_match, ARRAY_SIZE(off), off, 0);
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| 237 | regfree(&match);
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| 238 | //bb_error_msg("matches:");
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| 239 | //for (int i = 0; i < ARRAY_SIZE(off); i++) {
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| 240 | // if (off[i].rm_so < 0) continue;
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| 241 | // bb_error_msg("match %d: '%.*s'\n", i,
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| 242 | // (int)(off[i].rm_eo - off[i].rm_so),
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| 243 | // device_name + off[i].rm_so);
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| 244 | //}
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| 245 |
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| 246 | /* If no match, skip rest of line */
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| 247 | /* (regexec returns whole pattern as "range" 0) */
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| 248 | if (result
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| 249 | || off[0].rm_so
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| 250 | || ((int)off[0].rm_eo != (int)strlen(str_to_match))
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| 251 | ) {
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| 252 | continue; /* this line doesn't match */
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| 253 | }
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| 254 | }
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| 255 | line_matches:
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| 256 | /* This line matches. Stop parsing after parsing
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| 257 | * the rest the line unless keep_matching == 1 */
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| 258 |
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| 259 | /* 2nd field: uid:gid - device ownership */
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| 260 | if (get_uidgid(&ugid, tokens[1], 1) == 0)
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| 261 | bb_error_msg("unknown user/group %s on line %d", tokens[1], parser->lineno);
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| 262 |
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| 263 | /* 3rd field: mode - device permissions */
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| 264 | bb_parse_mode(tokens[2], &mode);
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| 265 |
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| 266 | val = tokens[3];
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| 267 | /* 4th field (opt): ">|=alias" or "!" to not create the node */
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| 268 |
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| 269 | if (ENABLE_FEATURE_MDEV_RENAME && val) {
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| 270 | char *a, *s, *st;
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| 271 |
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| 272 | a = val;
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| 273 | s = strchrnul(val, ' ');
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| 274 | st = strchrnul(val, '\t');
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| 275 | if (st < s)
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| 276 | s = st;
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| 277 | st = (s[0] && s[1]) ? s+1 : NULL;
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| 278 |
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| 279 | aliaslink = a[0];
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| 280 | if (aliaslink == '!' && s == a+1) {
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| 281 | val = st;
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| 282 | /* "!": suppress node creation/deletion */
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| 283 | major = -2;
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| 284 | }
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| 285 | else if (aliaslink == '>' || aliaslink == '=') {
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| 286 | val = st;
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| 287 | s[0] = '\0';
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| 288 | if (ENABLE_FEATURE_MDEV_RENAME_REGEXP) {
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| 289 | char *p;
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| 290 | unsigned i, n;
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| 291 |
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| 292 | /* substitute %1..9 with off[1..9], if any */
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| 293 | n = 0;
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| 294 | s = a;
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| 295 | while (*s)
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| 296 | if (*s++ == '%')
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| 297 | n++;
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| 298 |
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| 299 | p = alias = xzalloc(strlen(a) + n * strlen(str_to_match));
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| 300 | s = a + 1;
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| 301 | while (*s) {
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| 302 | *p = *s;
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| 303 | if ('%' == *s) {
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| 304 | i = (s[1] - '0');
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| 305 | if (i <= 9 && off[i].rm_so >= 0) {
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| 306 | n = off[i].rm_eo - off[i].rm_so;
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| 307 | strncpy(p, str_to_match + off[i].rm_so, n);
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| 308 | p += n - 1;
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| 309 | s++;
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| 310 | }
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| 311 | }
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| 312 | p++;
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| 313 | s++;
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| 314 | }
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| 315 | } else {
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| 316 | alias = xstrdup(a + 1);
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| 317 | }
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| 318 | }
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| 319 | }
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| 320 |
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| 321 | if (ENABLE_FEATURE_MDEV_EXEC && val) {
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| 322 | const char *s = "$@*";
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| 323 | const char *s2 = strchr(s, val[0]);
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| 324 |
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| 325 | if (!s2) {
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| 326 | bb_error_msg("bad line %u", parser->lineno);
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| 327 | if (ENABLE_FEATURE_MDEV_RENAME)
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| 328 | free(alias);
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| 329 | continue;
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| 330 | }
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| 331 |
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| 332 | /* Are we running this command now?
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| 333 | * Run $cmd on delete, @cmd on create, *cmd on both
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| 334 | */
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| 335 | if (s2 - s != delete) {
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| 336 | /* We are here if: '*',
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| 337 | * or: '@' and delete = 0,
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| 338 | * or: '$' and delete = 1
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| 339 | */
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| 340 | command = xstrdup(val + 1);
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| 341 | }
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| 342 | }
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| 343 | }
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| 344 |
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| 345 | /* End of field parsing */
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| 346 |
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| 347 | /* "Execute" the line we found */
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| 348 | {
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| 349 | const char *node_name;
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| 350 |
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| 351 | node_name = device_name;
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| 352 | if (ENABLE_FEATURE_MDEV_RENAME && alias)
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| 353 | node_name = alias = build_alias(alias, device_name);
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| 354 |
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| 355 | if (!delete && major >= 0) {
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| 356 | if (mknod(node_name, mode | type, makedev(major, minor)) && errno != EEXIST)
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| 357 | bb_perror_msg("can't create '%s'", node_name);
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| 358 | if (major == G.root_major && minor == G.root_minor)
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| 359 | symlink(node_name, "root");
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| 360 | if (ENABLE_FEATURE_MDEV_CONF) {
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| 361 | chmod(node_name, mode);
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| 362 | chown(node_name, ugid.uid, ugid.gid);
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| 363 | }
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| 364 | if (ENABLE_FEATURE_MDEV_RENAME && alias) {
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| 365 | if (aliaslink == '>')
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| 366 | symlink(node_name, device_name);
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| 367 | }
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| 368 | }
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| 369 |
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| 370 | if (ENABLE_FEATURE_MDEV_EXEC && command) {
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| 371 | /* setenv will leak memory, use putenv/unsetenv/free */
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| 372 | char *s = xasprintf("%s=%s", "MDEV", node_name);
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| 373 | char *s1 = xasprintf("%s=%s", "SUBSYSTEM", G.subsystem);
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| 374 | putenv(s);
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| 375 | putenv(s1);
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| 376 | if (system(command) == -1)
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| 377 | bb_perror_msg("can't run '%s'", command);
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| 378 | bb_unsetenv_and_free(s1);
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| 379 | bb_unsetenv_and_free(s);
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| 380 | free(command);
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| 381 | }
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| 382 |
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| 383 | if (delete && major >= -1) {
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| 384 | if (ENABLE_FEATURE_MDEV_RENAME && alias) {
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| 385 | if (aliaslink == '>')
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| 386 | unlink(device_name);
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| 387 | }
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| 388 | unlink(node_name);
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| 389 | }
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| 390 |
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| 391 | if (ENABLE_FEATURE_MDEV_RENAME)
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| 392 | free(alias);
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| 393 | }
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| 394 |
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| 395 | /* We found matching line.
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| 396 | * Stop unless it was prefixed with '-' */
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| 397 | if (ENABLE_FEATURE_MDEV_CONF && !keep_matching)
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| 398 | break;
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| 399 |
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| 400 | /* end of "while line is read from /etc/mdev.conf" */
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| 401 | } while (ENABLE_FEATURE_MDEV_CONF);
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| 402 |
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| 403 | if (ENABLE_FEATURE_MDEV_CONF)
|
---|
| 404 | config_close(parser);
|
---|
| 405 | free(subsystem_slash_devname);
|
---|
| 406 | }
|
---|
| 407 |
|
---|
| 408 | /* File callback for /sys/ traversal */
|
---|
| 409 | static int FAST_FUNC fileAction(const char *fileName,
|
---|
| 410 | struct stat *statbuf UNUSED_PARAM,
|
---|
| 411 | void *userData,
|
---|
| 412 | int depth UNUSED_PARAM)
|
---|
| 413 | {
|
---|
| 414 | size_t len = strlen(fileName) - 4; /* can't underflow */
|
---|
| 415 | char *scratch = userData;
|
---|
| 416 |
|
---|
| 417 | /* len check is for paranoid reasons */
|
---|
| 418 | if (strcmp(fileName + len, "/dev") != 0 || len >= PATH_MAX)
|
---|
| 419 | return FALSE;
|
---|
| 420 |
|
---|
| 421 | strcpy(scratch, fileName);
|
---|
| 422 | scratch[len] = '\0';
|
---|
| 423 | make_device(scratch, /*delete:*/ 0);
|
---|
| 424 |
|
---|
| 425 | return TRUE;
|
---|
| 426 | }
|
---|
| 427 |
|
---|
| 428 | /* Directory callback for /sys/ traversal */
|
---|
| 429 | static int FAST_FUNC dirAction(const char *fileName UNUSED_PARAM,
|
---|
| 430 | struct stat *statbuf UNUSED_PARAM,
|
---|
| 431 | void *userData UNUSED_PARAM,
|
---|
| 432 | int depth)
|
---|
| 433 | {
|
---|
| 434 | /* Extract device subsystem -- the name of the directory
|
---|
| 435 | * under /sys/class/ */
|
---|
| 436 | if (1 == depth) {
|
---|
| 437 | free(G.subsystem);
|
---|
| 438 | G.subsystem = strrchr(fileName, '/');
|
---|
| 439 | if (G.subsystem)
|
---|
| 440 | G.subsystem = xstrdup(G.subsystem + 1);
|
---|
| 441 | }
|
---|
| 442 |
|
---|
| 443 | return (depth >= MAX_SYSFS_DEPTH ? SKIP : TRUE);
|
---|
| 444 | }
|
---|
| 445 |
|
---|
| 446 | /* For the full gory details, see linux/Documentation/firmware_class/README
|
---|
| 447 | *
|
---|
| 448 | * Firmware loading works like this:
|
---|
| 449 | * - kernel sets FIRMWARE env var
|
---|
| 450 | * - userspace checks /lib/firmware/$FIRMWARE
|
---|
| 451 | * - userspace waits for /sys/$DEVPATH/loading to appear
|
---|
| 452 | * - userspace writes "1" to /sys/$DEVPATH/loading
|
---|
| 453 | * - userspace copies /lib/firmware/$FIRMWARE into /sys/$DEVPATH/data
|
---|
| 454 | * - userspace writes "0" (worked) or "-1" (failed) to /sys/$DEVPATH/loading
|
---|
| 455 | * - kernel loads firmware into device
|
---|
| 456 | */
|
---|
| 457 | static void load_firmware(const char *firmware, const char *sysfs_path)
|
---|
| 458 | {
|
---|
| 459 | int cnt;
|
---|
| 460 | int firmware_fd, loading_fd, data_fd;
|
---|
| 461 |
|
---|
| 462 | /* check for /lib/firmware/$FIRMWARE */
|
---|
| 463 | xchdir("/lib/firmware");
|
---|
| 464 | firmware_fd = xopen(firmware, O_RDONLY);
|
---|
| 465 |
|
---|
| 466 | /* in case we goto out ... */
|
---|
| 467 | data_fd = -1;
|
---|
| 468 |
|
---|
| 469 | /* check for /sys/$DEVPATH/loading ... give 30 seconds to appear */
|
---|
| 470 | xchdir(sysfs_path);
|
---|
| 471 | for (cnt = 0; cnt < 30; ++cnt) {
|
---|
| 472 | loading_fd = open("loading", O_WRONLY);
|
---|
| 473 | if (loading_fd != -1)
|
---|
| 474 | goto loading;
|
---|
| 475 | sleep(1);
|
---|
| 476 | }
|
---|
| 477 | goto out;
|
---|
| 478 |
|
---|
| 479 | loading:
|
---|
| 480 | /* tell kernel we're loading by "echo 1 > /sys/$DEVPATH/loading" */
|
---|
| 481 | if (full_write(loading_fd, "1", 1) != 1)
|
---|
| 482 | goto out;
|
---|
| 483 |
|
---|
| 484 | /* load firmware into /sys/$DEVPATH/data */
|
---|
| 485 | data_fd = open("data", O_WRONLY);
|
---|
| 486 | if (data_fd == -1)
|
---|
| 487 | goto out;
|
---|
| 488 | cnt = bb_copyfd_eof(firmware_fd, data_fd);
|
---|
| 489 |
|
---|
| 490 | /* tell kernel result by "echo [0|-1] > /sys/$DEVPATH/loading" */
|
---|
| 491 | if (cnt > 0)
|
---|
| 492 | full_write(loading_fd, "0", 1);
|
---|
| 493 | else
|
---|
| 494 | full_write(loading_fd, "-1", 2);
|
---|
| 495 |
|
---|
| 496 | out:
|
---|
| 497 | if (ENABLE_FEATURE_CLEAN_UP) {
|
---|
| 498 | close(firmware_fd);
|
---|
| 499 | close(loading_fd);
|
---|
| 500 | close(data_fd);
|
---|
| 501 | }
|
---|
| 502 | }
|
---|
| 503 |
|
---|
| 504 | int mdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
---|
| 505 | int mdev_main(int argc UNUSED_PARAM, char **argv)
|
---|
| 506 | {
|
---|
| 507 | RESERVE_CONFIG_BUFFER(temp, PATH_MAX + SCRATCH_SIZE);
|
---|
| 508 |
|
---|
| 509 | /* We can be called as hotplug helper */
|
---|
| 510 | /* Kernel cannot provide suitable stdio fds for us, do it ourself */
|
---|
| 511 | bb_sanitize_stdio();
|
---|
| 512 |
|
---|
| 513 | /* Force the configuration file settings exactly */
|
---|
| 514 | umask(0);
|
---|
| 515 |
|
---|
| 516 | xchdir("/dev");
|
---|
| 517 |
|
---|
| 518 | if (argv[1] && strcmp(argv[1], "-s") == 0) {
|
---|
| 519 | /* Scan:
|
---|
| 520 | * mdev -s
|
---|
| 521 | */
|
---|
| 522 | struct stat st;
|
---|
| 523 |
|
---|
| 524 | xstat("/", &st);
|
---|
| 525 | G.root_major = major(st.st_dev);
|
---|
| 526 | G.root_minor = minor(st.st_dev);
|
---|
| 527 |
|
---|
| 528 | /* ACTION_FOLLOWLINKS is needed since in newer kernels
|
---|
| 529 | * /sys/block/loop* (for example) are symlinks to dirs,
|
---|
| 530 | * not real directories.
|
---|
| 531 | * (kernel's CONFIG_SYSFS_DEPRECATED makes them real dirs,
|
---|
| 532 | * but we can't enforce that on users)
|
---|
| 533 | */
|
---|
| 534 | if (access("/sys/class/block", F_OK) != 0) {
|
---|
| 535 | /* Scan obsolete /sys/block only if /sys/class/block
|
---|
| 536 | * doesn't exist. Otherwise we'll have dupes.
|
---|
| 537 | * Also, do not complain if it doesn't exist.
|
---|
| 538 | * Some people configure kernel to have no blockdevs.
|
---|
| 539 | */
|
---|
| 540 | recursive_action("/sys/block",
|
---|
| 541 | ACTION_RECURSE | ACTION_FOLLOWLINKS | ACTION_QUIET,
|
---|
| 542 | fileAction, dirAction, temp, 0);
|
---|
| 543 | }
|
---|
| 544 | recursive_action("/sys/class",
|
---|
| 545 | ACTION_RECURSE | ACTION_FOLLOWLINKS,
|
---|
| 546 | fileAction, dirAction, temp, 0);
|
---|
| 547 | } else {
|
---|
| 548 | char *fw;
|
---|
| 549 | char *seq;
|
---|
| 550 | char *action;
|
---|
| 551 | char *env_path;
|
---|
| 552 | static const char keywords[] ALIGN1 = "remove\0add\0";
|
---|
| 553 | enum { OP_remove = 0, OP_add };
|
---|
| 554 | smalluint op;
|
---|
| 555 |
|
---|
| 556 | /* Hotplug:
|
---|
| 557 | * env ACTION=... DEVPATH=... SUBSYSTEM=... [SEQNUM=...] mdev
|
---|
| 558 | * ACTION can be "add" or "remove"
|
---|
| 559 | * DEVPATH is like "/block/sda" or "/class/input/mice"
|
---|
| 560 | */
|
---|
| 561 | action = getenv("ACTION");
|
---|
| 562 | env_path = getenv("DEVPATH");
|
---|
| 563 | G.subsystem = getenv("SUBSYSTEM");
|
---|
| 564 | if (!action || !env_path /*|| !G.subsystem*/)
|
---|
| 565 | bb_show_usage();
|
---|
| 566 | fw = getenv("FIRMWARE");
|
---|
| 567 | op = index_in_strings(keywords, action);
|
---|
| 568 | /* If it exists, does /dev/mdev.seq match $SEQNUM?
|
---|
| 569 | * If it does not match, earlier mdev is running
|
---|
| 570 | * in parallel, and we need to wait */
|
---|
| 571 | seq = getenv("SEQNUM");
|
---|
| 572 | if (seq) {
|
---|
| 573 | int timeout = 2000 / 32; /* 2000 msec */
|
---|
| 574 | do {
|
---|
| 575 | int seqlen;
|
---|
| 576 | char seqbuf[sizeof(int)*3 + 2];
|
---|
| 577 |
|
---|
| 578 | seqlen = open_read_close("mdev.seq", seqbuf, sizeof(seqbuf-1));
|
---|
| 579 | if (seqlen < 0) {
|
---|
| 580 | seq = NULL;
|
---|
| 581 | break;
|
---|
| 582 | }
|
---|
| 583 | seqbuf[seqlen] = '\0';
|
---|
| 584 | if (seqbuf[0] == '\n' /* seed file? */
|
---|
| 585 | || strcmp(seq, seqbuf) == 0 /* correct idx? */
|
---|
| 586 | ) {
|
---|
| 587 | break;
|
---|
| 588 | }
|
---|
| 589 | usleep(32*1000);
|
---|
| 590 | } while (--timeout);
|
---|
| 591 | }
|
---|
| 592 |
|
---|
| 593 | snprintf(temp, PATH_MAX, "/sys%s", env_path);
|
---|
| 594 | if (op == OP_remove) {
|
---|
| 595 | /* Ignoring "remove firmware". It was reported
|
---|
| 596 | * to happen and to cause erroneous deletion
|
---|
| 597 | * of device nodes. */
|
---|
| 598 | if (!fw)
|
---|
| 599 | make_device(temp, /*delete:*/ 1);
|
---|
| 600 | }
|
---|
| 601 | else if (op == OP_add) {
|
---|
| 602 | make_device(temp, /*delete:*/ 0);
|
---|
| 603 | if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE) {
|
---|
| 604 | if (fw)
|
---|
| 605 | load_firmware(fw, temp);
|
---|
| 606 | }
|
---|
| 607 | }
|
---|
| 608 |
|
---|
| 609 | if (seq) {
|
---|
| 610 | xopen_xwrite_close("mdev.seq", utoa(xatou(seq) + 1));
|
---|
| 611 | }
|
---|
| 612 | }
|
---|
| 613 |
|
---|
| 614 | if (ENABLE_FEATURE_CLEAN_UP)
|
---|
| 615 | RELEASE_CONFIG_BUFFER(temp);
|
---|
| 616 |
|
---|
| 617 | return EXIT_SUCCESS;
|
---|
| 618 | }
|
---|