/* vi: set sw=4 ts=4: */
/*
- *
* mdev - Mini udev for busybox
*
* Copyright 2005 Rob Landley <rob@landley.net>
* Copyright 2005 Frank Sorenson <frank@tuxrocks.com>
*
- * Licensed under GPL version 2, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*/
+//config:config MDEV
+//config: bool "mdev"
+//config: default y
+//config: select PLATFORM_LINUX
+//config: help
+//config: mdev is a mini-udev implementation for dynamically creating device
+//config: nodes in the /dev directory.
+//config:
+//config: For more information, please see docs/mdev.txt
+//config:
+//config:config FEATURE_MDEV_CONF
+//config: bool "Support /etc/mdev.conf"
+//config: default y
+//config: depends on MDEV
+//config: help
+//config: Add support for the mdev config file to control ownership and
+//config: permissions of the device nodes.
+//config:
+//config: For more information, please see docs/mdev.txt
+//config:
+//config:config FEATURE_MDEV_RENAME
+//config: bool "Support subdirs/symlinks"
+//config: default y
+//config: depends on FEATURE_MDEV_CONF
+//config: help
+//config: Add support for renaming devices and creating symlinks.
+//config:
+//config: For more information, please see docs/mdev.txt
+//config:
+//config:config FEATURE_MDEV_RENAME_REGEXP
+//config: bool "Support regular expressions substitutions when renaming device"
+//config: default y
+//config: depends on FEATURE_MDEV_RENAME
+//config: help
+//config: Add support for regular expressions substitutions when renaming
+//config: device.
+//config:
+//config:config FEATURE_MDEV_EXEC
+//config: bool "Support command execution at device addition/removal"
+//config: default y
+//config: depends on FEATURE_MDEV_CONF
+//config: help
+//config: This adds support for an optional field to /etc/mdev.conf for
+//config: executing commands when devices are created/removed.
+//config:
+//config: For more information, please see docs/mdev.txt
+//config:
+//config:config FEATURE_MDEV_LOAD_FIRMWARE
+//config: bool "Support loading of firmwares"
+//config: default y
+//config: depends on MDEV
+//config: help
+//config: Some devices need to load firmware before they can be usable.
+//config:
+//config: These devices will request userspace look up the files in
+//config: /lib/firmware/ and if it exists, send it to the kernel for
+//config: loading into the hardware.
+
+//applet:IF_MDEV(APPLET(mdev, BB_DIR_SBIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_MDEV) += mdev.o
+
+//usage:#define mdev_trivial_usage
+//usage: "[-s]"
+//usage:#define mdev_full_usage "\n\n"
+//usage: "mdev -s is to be run during boot to scan /sys and populate /dev.\n"
+//usage: "\n"
+//usage: "Bare mdev is a kernel hotplug helper. To activate it:\n"
+//usage: " echo /sbin/mdev >/proc/sys/kernel/hotplug\n"
+//usage: IF_FEATURE_MDEV_CONF(
+//usage: "\n"
+//usage: "It uses /etc/mdev.conf with lines\n"
+//usage: " [-][ENV=regex;]...DEVNAME UID:GID PERM"
+//usage: IF_FEATURE_MDEV_RENAME(" [>|=PATH]|[!]")
+//usage: IF_FEATURE_MDEV_EXEC(" [@|$|*PROG]")
+//usage: "\n"
+//usage: "where DEVNAME is device name regex, @major,minor[-minor2], or\n"
+//usage: "environment variable regex. A common use of the latter is\n"
+//usage: "to load modules for hotplugged devices:\n"
+//usage: " $MODALIAS=.* 0:0 660 @modprobe \"$MODALIAS\"\n"
+//usage: )
+//usage: "\n"
+//usage: "If /dev/mdev.seq file exists, mdev will wait for its value\n"
+//usage: "to match $SEQNUM variable. This prevents plug/unplug races.\n"
+//usage: "To activate this feature, create empty /dev/mdev.seq at boot.\n"
+//usage: "\n"
+//usage: "If /dev/mdev.log file exists, debug log will be appended to it."
+
#include "libbb.h"
#include "xregex.h"
+/* "mdev -s" scans /sys/class/xxx, looking for directories which have dev
+ * file (it is of the form "M:m\n"). Example: /sys/class/tty/tty0/dev
+ * contains "4:0\n". Directory name is taken as device name, path component
+ * directly after /sys/class/ as subsystem. In this example, "tty0" and "tty".
+ * Then mdev creates the /dev/device_name node.
+ * If /sys/class/.../dev file does not exist, mdev still may act
+ * on this device: see "@|$|*command args..." parameter in config file.
+ *
+ * mdev w/o parameters is called as hotplug helper. It takes device
+ * and subsystem names from $DEVPATH and $SUBSYSTEM, extracts
+ * maj,min from "/sys/$DEVPATH/dev" and also examines
+ * $ACTION ("add"/"delete") and $FIRMWARE.
+ *
+ * If action is "add", mdev creates /dev/device_name similarly to mdev -s.
+ * (todo: explain "delete" and $FIRMWARE)
+ *
+ * If /etc/mdev.conf exists, it may modify /dev/device_name's properties.
+ *
+ * Leading minus in 1st field means "don't stop on this line", otherwise
+ * search is stopped after the matching line is encountered.
+ *
+ * $envvar=regex format is useful for loading modules for hot-plugged devices
+ * which do not have driver loaded yet. In this case /sys/class/.../dev
+ * does not exist, but $MODALIAS is set to needed module's name
+ * (actually, an alias to it) by kernel. This rule instructs mdev
+ * to load the module and exit:
+ * $MODALIAS=.* 0:0 660 @modprobe "$MODALIAS"
+ * The kernel will generate another hotplug event when /sys/class/.../dev
+ * file appears.
+ *
+ * When line matches, the device node is created, chmod'ed and chown'ed,
+ * moved to path, and if >path, a symlink to moved node is created,
+ * all this if /sys/class/.../dev exists.
+ * Examples:
+ * =loop/ - moves to /dev/loop
+ * >disk/sda%1 - moves to /dev/disk/sdaN, makes /dev/sdaN a symlink
+ *
+ * Then "command args..." is executed (via sh -c 'command args...').
+ * @:execute on creation, $:on deletion, *:on both.
+ * This happens regardless of /sys/class/.../dev existence.
+ */
+
+/* Kernel's hotplug environment constantly changes.
+ * Here are new cases I observed on 3.1.0:
+ *
+ * Case with $DEVNAME and $DEVICE, not just $DEVPATH:
+ * ACTION=add
+ * BUSNUM=001
+ * DEVICE=/proc/bus/usb/001/003
+ * DEVNAME=bus/usb/001/003
+ * DEVNUM=003
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5
+ * DEVTYPE=usb_device
+ * MAJOR=189
+ * MINOR=2
+ * PRODUCT=18d1/4e12/227
+ * SUBSYSTEM=usb
+ * TYPE=0/0/0
+ *
+ * Case with $DEVICE, but no $DEVNAME - apparenty, usb iface notification?
+ * "Please load me a module" thing?
+ * ACTION=add
+ * DEVICE=/proc/bus/usb/001/003
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0
+ * DEVTYPE=usb_interface
+ * INTERFACE=8/6/80
+ * MODALIAS=usb:v18D1p4E12d0227dc00dsc00dp00ic08isc06ip50
+ * PRODUCT=18d1/4e12/227
+ * SUBSYSTEM=usb
+ * TYPE=0/0/0
+ *
+ * ACTION=add
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5
+ * DEVTYPE=scsi_host
+ * SUBSYSTEM=scsi
+ *
+ * ACTION=add
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5/scsi_host/host5
+ * SUBSYSTEM=scsi_host
+ *
+ * ACTION=add
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5/target5:0:0
+ * DEVTYPE=scsi_target
+ * SUBSYSTEM=scsi
+ *
+ * Case with strange $MODALIAS:
+ * ACTION=add
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5/target5:0:0/5:0:0:0
+ * DEVTYPE=scsi_device
+ * MODALIAS=scsi:t-0x00
+ * SUBSYSTEM=scsi
+ *
+ * ACTION=add
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5/target5:0:0/5:0:0:0/scsi_disk/5:0:0:0
+ * SUBSYSTEM=scsi_disk
+ *
+ * ACTION=add
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5/target5:0:0/5:0:0:0/scsi_device/5:0:0:0
+ * SUBSYSTEM=scsi_device
+ *
+ * Case with explicit $MAJOR/$MINOR (no need to read /sys/$DEVPATH/dev?):
+ * ACTION=add
+ * DEVNAME=bsg/5:0:0:0
+ * DEVPATH=/devices/pci0000:00/0000:00:02.1/usb1/1-5/1-5:1.0/host5/target5:0:0/5:0:0:0/bsg/5:0:0:0
+ * MAJOR=253
+ * MINOR=1
+ * SUBSYSTEM=bsg
+ *
+ * ACTION=add
+ * DEVPATH=/devices/virtual/bdi/8:16
+ * SUBSYSTEM=bdi
+ *
+ * ACTION=add
+ * DEVNAME=sdb
+ * DEVPATH=/block/sdb
+ * DEVTYPE=disk
+ * MAJOR=8
+ * MINOR=16
+ * SUBSYSTEM=block
+ *
+ * Case with ACTION=change:
+ * ACTION=change
+ * DEVNAME=sdb
+ * DEVPATH=/block/sdb
+ * DEVTYPE=disk
+ * DISK_MEDIA_CHANGE=1
+ * MAJOR=8
+ * MINOR=16
+ * SUBSYSTEM=block
+ */
+
+#define DEBUG_LVL 2
+
+#if DEBUG_LVL >= 1
+# define dbg1(...) do { if (G.verbose) bb_error_msg(__VA_ARGS__); } while(0)
+#else
+# define dbg1(...) ((void)0)
+#endif
+#if DEBUG_LVL >= 2
+# define dbg2(...) do { if (G.verbose >= 2) bb_error_msg(__VA_ARGS__); } while(0)
+#else
+# define dbg2(...) ((void)0)
+#endif
+#if DEBUG_LVL >= 3
+# define dbg3(...) do { if (G.verbose >= 3) bb_error_msg(__VA_ARGS__); } while(0)
+#else
+# define dbg3(...) ((void)0)
+#endif
+
+
+static const char keywords[] ALIGN1 = "add\0remove\0"; // "change\0"
+enum { OP_add, OP_remove };
+
+struct envmatch {
+ struct envmatch *next;
+ char *envname;
+ regex_t match;
+};
+
+struct rule {
+ bool keep_matching;
+ bool regex_compiled;
+ mode_t mode;
+ int maj, min0, min1;
+ struct bb_uidgid_t ugid;
+ char *envvar;
+ char *ren_mov;
+ IF_FEATURE_MDEV_EXEC(char *r_cmd;)
+ regex_t match;
+ struct envmatch *envmatch;
+};
+
struct globals {
int root_major, root_minor;
-};
+ smallint verbose;
+ char *subsystem;
+ char *subsys_env; /* for putenv("SUBSYSTEM=subsystem") */
+#if ENABLE_FEATURE_MDEV_CONF
+ const char *filename;
+ parser_t *parser;
+ struct rule **rule_vec;
+ unsigned rule_idx;
+#endif
+ struct rule cur_rule;
+ char timestr[sizeof("60.123456")];
+} FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1)
-#define root_major (G.root_major)
-#define root_minor (G.root_minor)
+#define INIT_G() do { \
+ IF_NOT_FEATURE_MDEV_CONF(G.cur_rule.maj = -1;) \
+ IF_NOT_FEATURE_MDEV_CONF(G.cur_rule.mode = 0660;) \
+} while (0)
+
/* Prevent infinite loops in /sys symlinks */
#define MAX_SYSFS_DEPTH 3
-/* We use additional 64+ bytes in make_device() */
-#define SCRATCH_SIZE 80
+/* We use additional bytes in make_device() */
+#define SCRATCH_SIZE 128
+
+#if ENABLE_FEATURE_MDEV_CONF
+
+static void make_default_cur_rule(void)
+{
+ memset(&G.cur_rule, 0, sizeof(G.cur_rule));
+ G.cur_rule.maj = -1; /* "not a @major,minor rule" */
+ G.cur_rule.mode = 0660;
+}
+
+static void clean_up_cur_rule(void)
+{
+ struct envmatch *e;
+
+ free(G.cur_rule.envvar);
+ free(G.cur_rule.ren_mov);
+ if (G.cur_rule.regex_compiled)
+ regfree(&G.cur_rule.match);
+ IF_FEATURE_MDEV_EXEC(free(G.cur_rule.r_cmd);)
+ e = G.cur_rule.envmatch;
+ while (e) {
+ free(e->envname);
+ regfree(&e->match);
+ e = e->next;
+ }
+ make_default_cur_rule();
+}
+
+static char *parse_envmatch_pfx(char *val)
+{
+ struct envmatch **nextp = &G.cur_rule.envmatch;
+
+ for (;;) {
+ struct envmatch *e;
+ char *semicolon;
+ char *eq = strchr(val, '=');
+ if (!eq /* || eq == val? */)
+ return val;
+ if (endofname(val) != eq)
+ return val;
+ semicolon = strchr(eq, ';');
+ if (!semicolon)
+ return val;
+ /* ENVVAR=regex;... */
+ *nextp = e = xzalloc(sizeof(*e));
+ nextp = &e->next;
+ e->envname = xstrndup(val, eq - val);
+ *semicolon = '\0';
+ xregcomp(&e->match, eq + 1, REG_EXTENDED);
+ *semicolon = ';';
+ val = semicolon + 1;
+ }
+}
+
+static void parse_next_rule(void)
+{
+ /* Note: on entry, G.cur_rule is set to default */
+ while (1) {
+ char *tokens[4];
+ char *val;
+
+ /* No PARSE_EOL_COMMENTS, because command may contain '#' chars */
+ if (!config_read(G.parser, tokens, 4, 3, "# \t", PARSE_NORMAL & ~PARSE_EOL_COMMENTS))
+ break;
+
+ /* Fields: [-]regex uid:gid mode [alias] [cmd] */
+ dbg3("token1:'%s'", tokens[1]);
+
+ /* 1st field */
+ val = tokens[0];
+ G.cur_rule.keep_matching = ('-' == val[0]);
+ val += G.cur_rule.keep_matching; /* swallow leading dash */
+ val = parse_envmatch_pfx(val);
+ if (val[0] == '@') {
+ /* @major,minor[-minor2] */
+ /* (useful when name is ambiguous:
+ * "/sys/class/usb/lp0" and
+ * "/sys/class/printer/lp0")
+ */
+ int sc = sscanf(val, "@%u,%u-%u", &G.cur_rule.maj, &G.cur_rule.min0, &G.cur_rule.min1);
+ if (sc < 2 || G.cur_rule.maj < 0) {
+ bb_error_msg("bad @maj,min on line %d", G.parser->lineno);
+ goto next_rule;
+ }
+ if (sc == 2)
+ G.cur_rule.min1 = G.cur_rule.min0;
+ } else {
+ char *eq = strchr(val, '=');
+ if (val[0] == '$') {
+ /* $ENVVAR=regex ... */
+ val++;
+ if (!eq) {
+ bb_error_msg("bad $envvar=regex on line %d", G.parser->lineno);
+ goto next_rule;
+ }
+ G.cur_rule.envvar = xstrndup(val, eq - val);
+ val = eq + 1;
+ }
+ xregcomp(&G.cur_rule.match, val, REG_EXTENDED);
+ G.cur_rule.regex_compiled = 1;
+ }
+
+ /* 2nd field: uid:gid - device ownership */
+ if (get_uidgid(&G.cur_rule.ugid, tokens[1], /*allow_numeric:*/ 1) == 0) {
+ bb_error_msg("unknown user/group '%s' on line %d", tokens[1], G.parser->lineno);
+ goto next_rule;
+ }
+
+ /* 3rd field: mode - device permissions */
+ bb_parse_mode(tokens[2], &G.cur_rule.mode);
+
+ /* 4th field (opt): ">|=alias" or "!" to not create the node */
+ val = tokens[3];
+ if (ENABLE_FEATURE_MDEV_RENAME && val && strchr(">=!", val[0])) {
+ char *s = skip_non_whitespace(val);
+ G.cur_rule.ren_mov = xstrndup(val, s - val);
+ val = skip_whitespace(s);
+ }
+
+ if (ENABLE_FEATURE_MDEV_EXEC && val && val[0]) {
+ const char *s = "$@*";
+ const char *s2 = strchr(s, val[0]);
+ if (!s2) {
+ bb_error_msg("bad line %u", G.parser->lineno);
+ goto next_rule;
+ }
+ IF_FEATURE_MDEV_EXEC(G.cur_rule.r_cmd = xstrdup(val);)
+ }
+
+ return;
+ next_rule:
+ clean_up_cur_rule();
+ } /* while (config_read) */
+
+ dbg3("config_close(G.parser)");
+ config_close(G.parser);
+ G.parser = NULL;
+
+ return;
+}
+
+/* If mdev -s, we remember rules in G.rule_vec[].
+ * Otherwise, there is no point in doing it, and we just
+ * save only one parsed rule in G.cur_rule.
+ */
+static const struct rule *next_rule(void)
+{
+ struct rule *rule;
+
+ /* Open conf file if we didn't do it yet */
+ if (!G.parser && G.filename) {
+ dbg3("config_open('%s')", G.filename);
+ G.parser = config_open2(G.filename, fopen_for_read);
+ G.filename = NULL;
+ }
+
+ if (G.rule_vec) {
+ /* mdev -s */
+ /* Do we have rule parsed already? */
+ if (G.rule_vec[G.rule_idx]) {
+ dbg3("< G.rule_vec[G.rule_idx:%d]=%p", G.rule_idx, G.rule_vec[G.rule_idx]);
+ return G.rule_vec[G.rule_idx++];
+ }
+ make_default_cur_rule();
+ } else {
+ /* not mdev -s */
+ clean_up_cur_rule();
+ }
+
+ /* Parse one more rule if file isn't fully read */
+ rule = &G.cur_rule;
+ if (G.parser) {
+ parse_next_rule();
+ if (G.rule_vec) { /* mdev -s */
+ rule = memcpy(xmalloc(sizeof(G.cur_rule)), &G.cur_rule, sizeof(G.cur_rule));
+ G.rule_vec = xrealloc_vector(G.rule_vec, 4, G.rule_idx);
+ G.rule_vec[G.rule_idx++] = rule;
+ dbg3("> G.rule_vec[G.rule_idx:%d]=%p", G.rule_idx, G.rule_vec[G.rule_idx]);
+ }
+ }
+
+ return rule;
+}
+
+static int env_matches(struct envmatch *e)
+{
+ while (e) {
+ int r;
+ char *val = getenv(e->envname);
+ if (!val)
+ return 0;
+ r = regexec(&e->match, val, /*size*/ 0, /*range[]*/ NULL, /*eflags*/ 0);
+ if (r != 0) /* no match */
+ return 0;
+ e = e->next;
+ }
+ return 1;
+}
+
+#else
+
+# define next_rule() (&G.cur_rule)
+
+#endif
+
+static void mkdir_recursive(char *name)
+{
+ /* if name has many levels ("dir1/dir2"),
+ * bb_make_directory() will create dir1 according to umask,
+ * not according to its "mode" parameter.
+ * Since we run with umask=0, need to temporarily switch it.
+ */
+ umask(022); /* "dir1" (if any) will be 0755 too */
+ bb_make_directory(name, 0755, FILEUTILS_RECUR);
+ umask(0);
+}
-#if ENABLE_FEATURE_MDEV_RENAME
/* Builds an alias path.
* This function potentionally reallocates the alias parameter.
+ * Only used for ENABLE_FEATURE_MDEV_RENAME
*/
static char *build_alias(char *alias, const char *device_name)
{
dest = strrchr(alias, '/');
if (dest) { /* ">bar/[baz]" ? */
*dest = '\0'; /* mkdir bar */
- bb_make_directory(alias, 0755, FILEUTILS_RECUR);
+ mkdir_recursive(alias);
*dest = '/';
if (dest[1] == '\0') { /* ">bar/" => ">bar/device_name" */
dest = alias;
return alias;
}
-#endif
-/* mknod in /dev based on a path like "/sys/block/hda/hda1" */
-/* NB: "mdev -s" may call us many times, do not leak memory/fds! */
-static void make_device(char *path, int delete)
+/* mknod in /dev based on a path like "/sys/block/hda/hda1"
+ * NB1: path parameter needs to have SCRATCH_SIZE scratch bytes
+ * after NUL, but we promise to not mangle (IOW: to restore NUL if needed)
+ * path string.
+ * NB2: "mdev -s" may call us many times, do not leak memory/fds!
+ *
+ * device_name = $DEVNAME (may be NULL)
+ * path = /sys/$DEVPATH
+ */
+static void make_device(char *device_name, char *path, int operation)
{
- const char *device_name;
int major, minor, type, len;
- int mode = 0660;
-#if ENABLE_FEATURE_MDEV_CONF
- struct bb_uidgid_t ugid = { 0, 0 };
- parser_t *parser;
- char *tokens[5];
-#endif
-#if ENABLE_FEATURE_MDEV_EXEC
- char *command = NULL;
-#endif
-#if ENABLE_FEATURE_MDEV_RENAME
- char *alias = NULL;
- char aliaslink = aliaslink; /* for compiler */
-#endif
- char *dev_maj_min = path + strlen(path);
-
- /* Force the configuration file settings exactly. */
- umask(0);
+ char *path_end = path + strlen(path);
/* Try to read major/minor string. Note that the kernel puts \n after
* the data, so we don't need to worry about null terminating the string
* We also depend on path having writeable space after it.
*/
major = -1;
- if (!delete) {
- strcpy(dev_maj_min, "/dev");
- len = open_read_close(path, dev_maj_min + 1, 64);
- *dev_maj_min++ = '\0';
+ if (operation == OP_add) {
+ strcpy(path_end, "/dev");
+ len = open_read_close(path, path_end + 1, SCRATCH_SIZE - 1);
+ *path_end = '\0';
if (len < 1) {
if (!ENABLE_FEATURE_MDEV_EXEC)
return;
- /* no "dev" file, so just try to run script */
- *dev_maj_min = '\0';
- } else if (sscanf(dev_maj_min, "%u:%u", &major, &minor) != 2) {
+ /* no "dev" file, but we can still run scripts
+ * based on device name */
+ } else if (sscanf(path_end + 1, "%u:%u", &major, &minor) == 2) {
+ dbg1("dev %u,%u", major, minor);
+ } else {
major = -1;
}
}
+ /* else: for delete, -1 still deletes the node, but < -1 suppresses that */
- /* Determine device name, type, major and minor */
- device_name = bb_basename(path);
- /* http://kernel.org/doc/pending/hotplug.txt says that only
+ /* Determine device name */
+ if (!device_name) {
+ /*
+ * There was no $DEVNAME envvar (for example, mdev -s never has).
+ * But it is very useful: it contains the *path*, not only basename,
+ * Thankfully, uevent file has it.
+ * Example of .../sound/card0/controlC0/uevent file on Linux-3.7.7:
+ * MAJOR=116
+ * MINOR=7
+ * DEVNAME=snd/controlC0
+ */
+ strcpy(path_end, "/uevent");
+ len = open_read_close(path, path_end + 1, SCRATCH_SIZE - 1);
+ if (len < 0)
+ len = 0;
+ *path_end = '\0';
+ path_end[1 + len] = '\0';
+ device_name = strstr(path_end + 1, "\nDEVNAME=");
+ if (device_name) {
+ device_name += sizeof("\nDEVNAME=")-1;
+ strchrnul(device_name, '\n')[0] = '\0';
+ } else {
+ /* Fall back to just basename */
+ device_name = (char*) bb_basename(path);
+ }
+ }
+ /* Determine device type */
+ /*
+ * http://kernel.org/doc/pending/hotplug.txt says that only
* "/sys/block/..." is for block devices. "/sys/bus" etc is not.
* But since 2.6.25 block devices are also in /sys/class/block.
- * We use strstr("/block/") to forestall future surprises. */
+ * We use strstr("/block/") to forestall future surprises.
+ */
type = S_IFCHR;
- if (strstr(path, "/block/"))
+ if (strstr(path, "/block/") || (G.subsystem && strncmp(G.subsystem, "block", 5) == 0))
type = S_IFBLK;
#if ENABLE_FEATURE_MDEV_CONF
- parser = config_open2("/etc/mdev.conf", fopen_for_read);
-
- /* If we have config file, look up user settings */
- while (config_read(parser, tokens, 4, 3, "# \t", PARSE_NORMAL)) {
- regmatch_t off[1 + 9*ENABLE_FEATURE_MDEV_RENAME_REGEXP];
- char *val;
+ G.rule_idx = 0; /* restart from the beginning (think mdev -s) */
+#endif
+ for (;;) {
+ const char *str_to_match;
+ regmatch_t off[1 + 9 * ENABLE_FEATURE_MDEV_RENAME_REGEXP];
+ char *command;
+ char *alias;
+ char aliaslink = aliaslink; /* for compiler */
+ char *node_name;
+ const struct rule *rule;
- /* Fields: regex uid:gid mode [alias] [cmd] */
+ str_to_match = device_name;
- /* 1st field: @<numeric maj,min>... */
- if (tokens[0][0] == '@') {
- /* @major,minor[-last] */
- /* (useful when name is ambiguous:
- * "/sys/class/usb/lp0" and
- * "/sys/class/printer/lp0") */
- int cmaj, cmin0, cmin1, sc;
- if (major < 0)
- continue; /* no dev, no match */
- sc = sscanf(tokens[0], "@%u,%u-%u", &cmaj, &cmin0, &cmin1);
- if (sc < 1 || major != cmaj
- || (sc == 2 && minor != cmin0)
- || (sc == 3 && (minor < cmin0 || minor > cmin1))
- ) {
- continue; /* no match */
- }
- } else { /* ... or regex to match device name */
- regex_t match;
- int result;
+ rule = next_rule();
- /* Is this it? */
- xregcomp(&match, tokens[0], REG_EXTENDED);
- result = regexec(&match, device_name, ARRAY_SIZE(off), off, 0);
- regfree(&match);
+#if ENABLE_FEATURE_MDEV_CONF
+ if (!env_matches(rule->envmatch))
+ continue;
+ if (rule->maj >= 0) { /* @maj,min rule */
+ if (major != rule->maj)
+ continue;
+ if (minor < rule->min0 || minor > rule->min1)
+ continue;
+ memset(off, 0, sizeof(off));
+ goto rule_matches;
+ }
+ if (rule->envvar) { /* $envvar=regex rule */
+ str_to_match = getenv(rule->envvar);
+ dbg3("getenv('%s'):'%s'", rule->envvar, str_to_match);
+ if (!str_to_match)
+ continue;
+ }
+ /* else: str_to_match = device_name */
+ if (rule->regex_compiled) {
+ int regex_match = regexec(&rule->match, str_to_match, ARRAY_SIZE(off), off, 0);
+ dbg3("regex_match for '%s':%d", str_to_match, regex_match);
//bb_error_msg("matches:");
//for (int i = 0; i < ARRAY_SIZE(off); i++) {
// if (off[i].rm_so < 0) continue;
// device_name + off[i].rm_so);
//}
- /* If not this device, skip rest of line */
- /* (regexec returns whole pattern as "range" 0) */
- if (result || off[0].rm_so
- || ((int)off[0].rm_eo != (int)strlen(device_name))
+ if (regex_match != 0
+ /* regexec returns whole pattern as "range" 0 */
+ || off[0].rm_so != 0
+ || (int)off[0].rm_eo != (int)strlen(str_to_match)
) {
- continue;
+ continue; /* this rule doesn't match */
}
}
+ /* else: it's final implicit "match-all" rule */
+ rule_matches:
+ dbg2("rule matched, line %d", G.parser ? G.parser->lineno : -1);
+#endif
+ /* Build alias name */
+ alias = NULL;
+ if (ENABLE_FEATURE_MDEV_RENAME && rule->ren_mov) {
+ aliaslink = rule->ren_mov[0];
+ if (aliaslink == '!') {
+ /* "!": suppress node creation/deletion */
+ major = -2;
+ }
+ else if (aliaslink == '>' || aliaslink == '=') {
+ if (ENABLE_FEATURE_MDEV_RENAME_REGEXP) {
+ char *s;
+ char *p;
+ unsigned n;
- /* This line matches: stop parsing the file
- * after parsing the rest of fields */
-
- /* 2nd field: uid:gid - device ownership */
- parse_chown_usergroup_or_die(&ugid, tokens[1]);
-
- /* 3rd field: mode - device permissions */
- mode = strtoul(tokens[2], NULL, 8);
+ /* substitute %1..9 with off[1..9], if any */
+ n = 0;
+ s = rule->ren_mov;
+ while (*s)
+ if (*s++ == '%')
+ n++;
- val = tokens[3];
- /* 4th field (opt): >alias */
-#if ENABLE_FEATURE_MDEV_RENAME
- if (!val)
- break;
- aliaslink = *val;
- if (aliaslink == '>' || aliaslink == '=') {
- char *s;
-#if ENABLE_FEATURE_MDEV_RENAME_REGEXP
- char *p;
- unsigned i, n;
-#endif
- char *a = val;
- s = strchrnul(val, ' ');
- val = (s[0] && s[1]) ? s+1 : NULL;
- s[0] = '\0';
-#if ENABLE_FEATURE_MDEV_RENAME_REGEXP
- /* substitute %1..9 with off[1..9], if any */
- n = 0;
- s = a;
- while (*s)
- if (*s++ == '%')
- n++;
-
- p = alias = xzalloc(strlen(a) + n * strlen(device_name));
- s = a + 1;
- while (*s) {
- *p = *s;
- if ('%' == *s) {
- i = (s[1] - '0');
- if (i <= 9 && off[i].rm_so >= 0) {
- n = off[i].rm_eo - off[i].rm_so;
- strncpy(p, device_name + off[i].rm_so, n);
- p += n - 1;
+ p = alias = xzalloc(strlen(rule->ren_mov) + n * strlen(str_to_match));
+ s = rule->ren_mov + 1;
+ while (*s) {
+ *p = *s;
+ if ('%' == *s) {
+ unsigned i = (s[1] - '0');
+ if (i <= 9 && off[i].rm_so >= 0) {
+ n = off[i].rm_eo - off[i].rm_so;
+ strncpy(p, str_to_match + off[i].rm_so, n);
+ p += n - 1;
+ s++;
+ }
+ }
+ p++;
s++;
}
+ } else {
+ alias = xstrdup(rule->ren_mov + 1);
}
- p++;
- s++;
}
-#else
- alias = xstrdup(a + 1);
-#endif
}
-#endif /* ENABLE_FEATURE_MDEV_RENAME */
+ dbg3("alias:'%s'", alias);
-#if ENABLE_FEATURE_MDEV_EXEC
- /* The rest (opt): command to run */
- if (!val)
- break;
- {
- const char *s = "@$*";
- const char *s2 = strchr(s, *val);
-
- if (!s2)
- bb_error_msg_and_die("bad line %u", parser->lineno);
-
- /* Correlate the position in the "@$*" with the delete
- * step so that we get the proper behavior:
- * @cmd: run on create
- * $cmd: run on delete
- * *cmd: run on both
+ command = NULL;
+ IF_FEATURE_MDEV_EXEC(command = rule->r_cmd;)
+ if (command) {
+ /* Are we running this command now?
+ * Run @cmd on create, $cmd on delete, *cmd on any
*/
- if ((s2 - s + 1) /*1/2/3*/ & /*1/2*/ (1 + delete)) {
- command = xstrdup(val + 1);
+ if ((command[0] == '@' && operation == OP_add)
+ || (command[0] == '$' && operation == OP_remove)
+ || (command[0] == '*')
+ ) {
+ command++;
+ } else {
+ command = NULL;
}
}
-#endif
- /* end of field parsing */
- break; /* we found matching line, stop */
- } /* end of "while line is read from /etc/mdev.conf" */
-
- config_close(parser);
-#endif /* ENABLE_FEATURE_MDEV_CONF */
-
- if (!delete && major >= 0) {
-
- if (ENABLE_FEATURE_MDEV_RENAME)
- unlink(device_name);
-
- if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
- bb_perror_msg_and_die("mknod %s", device_name);
-
- if (major == root_major && minor == root_minor)
- symlink(device_name, "root");
-
-#if ENABLE_FEATURE_MDEV_CONF
- chown(device_name, ugid.uid, ugid.gid);
+ dbg3("command:'%s'", command);
-#if ENABLE_FEATURE_MDEV_RENAME
- if (alias) {
- alias = build_alias(alias, device_name);
+ /* "Execute" the line we found */
+ node_name = device_name;
+ if (ENABLE_FEATURE_MDEV_RENAME && alias) {
+ node_name = alias = build_alias(alias, device_name);
+ dbg3("alias2:'%s'", alias);
+ }
- /* move the device, and optionally
- * make a symlink to moved device node */
- if (rename(device_name, alias) == 0 && aliaslink == '>')
- symlink(alias, device_name);
+ if (operation == OP_add && major >= 0) {
+ char *slash = strrchr(node_name, '/');
+ if (slash) {
+ *slash = '\0';
+ mkdir_recursive(node_name);
+ *slash = '/';
+ }
+ if (ENABLE_FEATURE_MDEV_CONF) {
+ dbg1("mknod %s (%d,%d) %o"
+ " %u:%u",
+ node_name, major, minor, rule->mode | type,
+ rule->ugid.uid, rule->ugid.gid
+ );
+ } else {
+ dbg1("mknod %s (%d,%d) %o",
+ node_name, major, minor, rule->mode | type
+ );
+ }
+ if (mknod(node_name, rule->mode | type, makedev(major, minor)) && errno != EEXIST)
+ bb_perror_msg("can't create '%s'", node_name);
+ if (ENABLE_FEATURE_MDEV_CONF) {
+ chmod(node_name, rule->mode);
+ chown(node_name, rule->ugid.uid, rule->ugid.gid);
+ }
+ if (major == G.root_major && minor == G.root_minor)
+ symlink(node_name, "root");
+ if (ENABLE_FEATURE_MDEV_RENAME && alias) {
+ if (aliaslink == '>') {
+//TODO: on devtmpfs, device_name already exists and symlink() fails.
+//End result is that instead of symlink, we have two nodes.
+//What should be done?
+ dbg1("symlink: %s", device_name);
+ symlink(node_name, device_name);
+ }
+ }
+ }
- free(alias);
+ if (ENABLE_FEATURE_MDEV_EXEC && command) {
+ /* setenv will leak memory, use putenv/unsetenv/free */
+ char *s = xasprintf("%s=%s", "MDEV", node_name);
+ putenv(s);
+ dbg1("running: %s", command);
+ if (system(command) == -1)
+ bb_perror_msg("can't run '%s'", command);
+ bb_unsetenv_and_free(s);
}
-#endif
-#endif
- }
-#if ENABLE_FEATURE_MDEV_EXEC
- if (command) {
- /* setenv will leak memory, use putenv/unsetenv/free */
- char *s = xasprintf("MDEV=%s", device_name);
- putenv(s);
- if (system(command) == -1)
- bb_perror_msg_and_die("can't run '%s'", command);
- unsetenv("MDEV");
- free(s);
- free(command);
- }
-#endif
+ if (operation == OP_remove && major >= -1) {
+ if (ENABLE_FEATURE_MDEV_RENAME && alias) {
+ if (aliaslink == '>') {
+ dbg1("unlink: %s", device_name);
+ unlink(device_name);
+ }
+ }
+ dbg1("unlink: %s", node_name);
+ unlink(node_name);
+ }
- if (delete) {
- unlink(device_name);
- /* At creation time, device might have been moved
- * and a symlink might have been created. Undo that. */
-#if ENABLE_FEATURE_MDEV_RENAME
- if (alias) {
- alias = build_alias(alias, device_name);
- unlink(alias);
+ if (ENABLE_FEATURE_MDEV_RENAME)
free(alias);
- }
-#endif
- }
+
+ /* We found matching line.
+ * Stop unless it was prefixed with '-'
+ */
+ if (!ENABLE_FEATURE_MDEV_CONF || !rule->keep_matching)
+ break;
+ } /* for (;;) */
}
/* File callback for /sys/ traversal */
strcpy(scratch, fileName);
scratch[len] = '\0';
- make_device(scratch, 0);
+ make_device(/*DEVNAME:*/ NULL, scratch, OP_add);
return TRUE;
}
void *userData UNUSED_PARAM,
int depth)
{
+ /* Extract device subsystem -- the name of the directory
+ * under /sys/class/ */
+ if (1 == depth) {
+ free(G.subsystem);
+ if (G.subsys_env) {
+ bb_unsetenv_and_free(G.subsys_env);
+ G.subsys_env = NULL;
+ }
+ G.subsystem = strrchr(fileName, '/');
+ if (G.subsystem) {
+ G.subsystem = xstrdup(G.subsystem + 1);
+ G.subsys_env = xasprintf("%s=%s", "SUBSYSTEM", G.subsystem);
+ putenv(G.subsys_env);
+ }
+ }
+
return (depth >= MAX_SYSFS_DEPTH ? SKIP : TRUE);
}
* - userspace writes "0" (worked) or "-1" (failed) to /sys/$DEVPATH/loading
* - kernel loads firmware into device
*/
-static void load_firmware(const char *const firmware, const char *const sysfs_path)
+static void load_firmware(const char *firmware, const char *sysfs_path)
{
int cnt;
- int firmware_fd, loading_fd, data_fd;
+ int firmware_fd, loading_fd;
/* check for /lib/firmware/$FIRMWARE */
xchdir("/lib/firmware");
- firmware_fd = xopen(firmware, O_RDONLY);
-
- /* in case we goto out ... */
- data_fd = -1;
+ firmware_fd = open(firmware, O_RDONLY); /* can fail */
/* check for /sys/$DEVPATH/loading ... give 30 seconds to appear */
xchdir(sysfs_path);
for (cnt = 0; cnt < 30; ++cnt) {
loading_fd = open("loading", O_WRONLY);
- if (loading_fd != -1)
+ if (loading_fd >= 0)
goto loading;
sleep(1);
}
goto out;
loading:
- /* tell kernel we're loading by `echo 1 > /sys/$DEVPATH/loading` */
- if (full_write(loading_fd, "1", 1) != 1)
- goto out;
+ cnt = 0;
+ if (firmware_fd >= 0) {
+ int data_fd;
+
+ /* tell kernel we're loading by "echo 1 > /sys/$DEVPATH/loading" */
+ if (full_write(loading_fd, "1", 1) != 1)
+ goto out;
- /* load firmware by `cat /lib/firmware/$FIRMWARE > /sys/$DEVPATH/data */
- data_fd = open("data", O_WRONLY);
- if (data_fd == -1)
- goto out;
- cnt = bb_copyfd_eof(firmware_fd, data_fd);
+ /* load firmware into /sys/$DEVPATH/data */
+ data_fd = open("data", O_WRONLY);
+ if (data_fd < 0)
+ goto out;
+ cnt = bb_copyfd_eof(firmware_fd, data_fd);
+ if (ENABLE_FEATURE_CLEAN_UP)
+ close(data_fd);
+ }
- /* tell kernel result by `echo [0|-1] > /sys/$DEVPATH/loading` */
+ /* Tell kernel result by "echo [0|-1] > /sys/$DEVPATH/loading"
+ * Note: we emit -1 also if firmware file wasn't found.
+ * There are cases when otherwise kernel would wait for minutes
+ * before timing out.
+ */
if (cnt > 0)
full_write(loading_fd, "0", 1);
else
full_write(loading_fd, "-1", 2);
out:
+ xchdir("/dev");
if (ENABLE_FEATURE_CLEAN_UP) {
close(firmware_fd);
close(loading_fd);
- close(data_fd);
+ }
+}
+
+static char *curtime(void)
+{
+ struct timeval tv;
+ gettimeofday(&tv, NULL);
+ sprintf(G.timestr, "%u.%06u", (unsigned)tv.tv_sec % 60, (unsigned)tv.tv_usec);
+ return G.timestr;
+}
+
+static void open_mdev_log(const char *seq, unsigned my_pid)
+{
+ int logfd = open("mdev.log", O_WRONLY | O_APPEND);
+ if (logfd >= 0) {
+ xmove_fd(logfd, STDERR_FILENO);
+ G.verbose = 2;
+ applet_name = xasprintf("%s[%s]", applet_name, seq ? seq : utoa(my_pid));
+ }
+}
+
+/* If it exists, does /dev/mdev.seq match $SEQNUM?
+ * If it does not match, earlier mdev is running
+ * in parallel, and we need to wait.
+ * Active mdev pokes us with SIGCHLD to check the new file.
+ */
+static int
+wait_for_seqfile(const char *seq)
+{
+ /* We time out after 2 sec */
+ static const struct timespec ts = { 0, 32*1000*1000 };
+ int timeout = 2000 / 32;
+ int seq_fd = -1;
+ int do_once = 1;
+ sigset_t set_CHLD;
+
+ sigemptyset(&set_CHLD);
+ sigaddset(&set_CHLD, SIGCHLD);
+ sigprocmask(SIG_BLOCK, &set_CHLD, NULL);
+
+ for (;;) {
+ int seqlen;
+ char seqbuf[sizeof(int)*3 + 2];
+
+ if (seq_fd < 0) {
+ seq_fd = open("mdev.seq", O_RDWR);
+ if (seq_fd < 0)
+ break;
+ }
+ seqlen = pread(seq_fd, seqbuf, sizeof(seqbuf) - 1, 0);
+ if (seqlen < 0) {
+ close(seq_fd);
+ seq_fd = -1;
+ break;
+ }
+ seqbuf[seqlen] = '\0';
+ if (seqbuf[0] == '\n') {
+ /* seed file: write out seq ASAP */
+ xwrite_str(seq_fd, seq);
+ xlseek(seq_fd, 0, SEEK_SET);
+ dbg2("first seq written");
+ break;
+ }
+ if (strcmp(seq, seqbuf) == 0) {
+ /* correct idx */
+ break;
+ }
+ if (do_once) {
+ dbg2("%s waiting for '%s'", curtime(), seqbuf);
+ do_once = 0;
+ }
+ if (sigtimedwait(&set_CHLD, NULL, &ts) >= 0) {
+ dbg3("woken up");
+ continue; /* don't decrement timeout! */
+ }
+ if (--timeout == 0) {
+ dbg1("%s waiting for '%s'", "timed out", seqbuf);
+ break;
+ }
+ }
+ sigprocmask(SIG_UNBLOCK, &set_CHLD, NULL);
+ return seq_fd;
+}
+
+static void signal_mdevs(unsigned my_pid)
+{
+ procps_status_t* p = NULL;
+ while ((p = procps_scan(p, PSSCAN_ARGV0)) != NULL) {
+ if (p->pid != my_pid
+ && p->argv0
+ && strcmp(bb_basename(p->argv0), "mdev") == 0
+ ) {
+ kill(p->pid, SIGCHLD);
+ }
}
}
{
RESERVE_CONFIG_BUFFER(temp, PATH_MAX + SCRATCH_SIZE);
+ INIT_G();
+
+#if ENABLE_FEATURE_MDEV_CONF
+ G.filename = "/etc/mdev.conf";
+#endif
+
/* We can be called as hotplug helper */
/* Kernel cannot provide suitable stdio fds for us, do it ourself */
-#if 1
bb_sanitize_stdio();
-#else
- /* Debug code */
- /* Replace LOGFILE by other file or device name if you need */
-#define LOGFILE "/dev/console"
- /* Just making sure fd 0 is not closed,
- * we don't really intend to read from it */
- xmove_fd(xopen("/", O_RDONLY), STDIN_FILENO);
- xmove_fd(xopen(LOGFILE, O_WRONLY|O_APPEND), STDOUT_FILENO);
- xmove_fd(xopen(LOGFILE, O_WRONLY|O_APPEND), STDERR_FILENO);
-#endif
+
+ /* Force the configuration file settings exactly */
+ umask(0);
xchdir("/dev");
- if (argv[1] && !strcmp(argv[1], "-s")) {
- /* Scan:
- * mdev -s
+ if (argv[1] && strcmp(argv[1], "-s") == 0) {
+ /*
+ * Scan: mdev -s
*/
struct stat st;
+#if ENABLE_FEATURE_MDEV_CONF
+ /* Same as xrealloc_vector(NULL, 4, 0): */
+ G.rule_vec = xzalloc((1 << 4) * sizeof(*G.rule_vec));
+#endif
xstat("/", &st);
- root_major = major(st.st_dev);
- root_minor = minor(st.st_dev);
+ G.root_major = major(st.st_dev);
+ G.root_minor = minor(st.st_dev);
+
+ putenv((char*)"ACTION=add");
/* ACTION_FOLLOWLINKS is needed since in newer kernels
* /sys/block/loop* (for example) are symlinks to dirs,
ACTION_RECURSE | ACTION_FOLLOWLINKS,
fileAction, dirAction, temp, 0);
} else {
+ char *fw;
char *seq;
char *action;
- char *env_path;
- char seqbuf[sizeof(int)*3 + 2];
- int seqlen = seqlen; /* for compiler */
+ char *env_devname;
+ char *env_devpath;
+ unsigned my_pid;
+ int seq_fd;
+ smalluint op;
/* Hotplug:
- * env ACTION=... DEVPATH=... [SEQNUM=...] mdev
- * ACTION can be "add" or "remove"
+ * env ACTION=... DEVPATH=... SUBSYSTEM=... [SEQNUM=...] mdev
+ * ACTION can be "add", "remove", "change"
* DEVPATH is like "/block/sda" or "/class/input/mice"
*/
+ env_devname = getenv("DEVNAME"); /* can be NULL */
+ G.subsystem = getenv("SUBSYSTEM");
action = getenv("ACTION");
- env_path = getenv("DEVPATH");
- if (!action || !env_path)
+ env_devpath = getenv("DEVPATH");
+ if (!action || !env_devpath /*|| !G.subsystem*/)
bb_show_usage();
-
+ fw = getenv("FIRMWARE");
seq = getenv("SEQNUM");
- if (seq) {
- int timeout = 2000 / 32;
- do {
- seqlen = open_read_close("mdev.seq", seqbuf, sizeof(seqbuf-1));
- if (seqlen < 0)
- break;
- seqbuf[seqlen] = '\0';
- if (seqbuf[0] == '\n' /* seed file? */
- || strcmp(seq, seqbuf) == 0 /* correct idx? */
- ) {
- break;
- }
- usleep(32*1000);
- } while (--timeout);
- }
+ op = index_in_strings(keywords, action);
- snprintf(temp, PATH_MAX, "/sys%s", env_path);
- if (!strcmp(action, "remove"))
- make_device(temp, 1);
- else if (!strcmp(action, "add")) {
- make_device(temp, 0);
+ my_pid = getpid();
+ open_mdev_log(seq, my_pid);
+ seq_fd = seq ? wait_for_seqfile(seq) : -1;
+
+ dbg1("%s "
+ "ACTION:%s SUBSYSTEM:%s DEVNAME:%s DEVPATH:%s"
+ "%s%s",
+ curtime(),
+ action, G.subsystem, env_devname, env_devpath,
+ fw ? " FW:" : "", fw ? fw : ""
+ );
+
+ snprintf(temp, PATH_MAX, "/sys%s", env_devpath);
+ if (op == OP_remove) {
+ /* Ignoring "remove firmware". It was reported
+ * to happen and to cause erroneous deletion
+ * of device nodes. */
+ if (!fw)
+ make_device(env_devname, temp, op);
+ }
+ else {
+ make_device(env_devname, temp, op);
if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE) {
- char *fw = getenv("FIRMWARE");
- if (fw)
+ if (op == OP_add && fw)
load_firmware(fw, temp);
}
}
- if (seq && seqlen >= 0) {
- xopen_xwrite_close("mdev.seq", utoa(xatou(seq) + 1));
+ dbg1("%s exiting", curtime());
+ if (seq_fd >= 0) {
+ xwrite_str(seq_fd, utoa(xatou(seq) + 1));
+ signal_mdevs(my_pid);
}
}
if (ENABLE_FEATURE_CLEAN_UP)
RELEASE_CONFIG_BUFFER(temp);
- return 0;
+ return EXIT_SUCCESS;
}
projects / platform / upstream / busybox.git / blobdiff