| /* 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 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 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 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); |
| } |
| |
| /* 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) |
| { |
| char *dest; |
| |
| /* ">bar/": rename to bar/device_name */ |
| /* ">bar[/]baz": rename to bar[/]baz */ |
| dest = strrchr(alias, '/'); |
| if (dest) { /* ">bar/[baz]" ? */ |
| *dest = '\0'; /* mkdir bar */ |
| mkdir_recursive(alias); |
| *dest = '/'; |
| if (dest[1] == '\0') { /* ">bar/" => ">bar/device_name" */ |
| dest = alias; |
| alias = concat_path_file(alias, device_name); |
| free(dest); |
| } |
| } |
| |
| return alias; |
| } |
| |
| /* 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) |
| { |
| int major, minor, type, len; |
| 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 |
| * because sscanf() will stop at the first nondigit, which \n is. |
| * We also depend on path having writeable space after it. |
| */ |
| major = -1; |
| 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, 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 */ |
| 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. |
| */ |
| type = S_IFCHR; |
| if (strstr(path, "/block/") || (G.subsystem && is_prefixed_with(G.subsystem, "block"))) |
| type = S_IFBLK; |
| |
| #if ENABLE_FEATURE_MDEV_CONF |
| 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; |
| |
| str_to_match = device_name; |
| |
| rule = next_rule(); |
| |
| #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; |
| // bb_error_msg("match %d: '%.*s'\n", i, |
| // (int)(off[i].rm_eo - off[i].rm_so), |
| // device_name + off[i].rm_so); |
| //} |
| |
| 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; /* 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; |
| |
| /* substitute %1..9 with off[1..9], if any */ |
| n = 0; |
| s = rule->ren_mov; |
| while (*s) |
| if (*s++ == '%') |
| n++; |
| |
| 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); |
| } |
| } |
| } |
| dbg3("alias:'%s'", alias); |
| |
| command = NULL; |
| IF_FEATURE_MDEV_EXEC(command = rule->r_cmd;) |
| if (command) { |
| /* Are we running this command now? |
| * Run @cmd on create, $cmd on delete, *cmd on any |
| */ |
| if ((command[0] == '@' && operation == OP_add) |
| || (command[0] == '$' && operation == OP_remove) |
| || (command[0] == '*') |
| ) { |
| command++; |
| } else { |
| command = NULL; |
| } |
| } |
| dbg3("command:'%s'", command); |
| |
| /* "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); |
| } |
| |
| 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); |
| } |
| } |
| } |
| |
| 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); |
| } |
| |
| 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 (ENABLE_FEATURE_MDEV_RENAME) |
| free(alias); |
| |
| /* 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 */ |
| static int FAST_FUNC fileAction(const char *fileName, |
| struct stat *statbuf UNUSED_PARAM, |
| void *userData, |
| int depth UNUSED_PARAM) |
| { |
| size_t len = strlen(fileName) - 4; /* can't underflow */ |
| char *scratch = userData; |
| |
| /* len check is for paranoid reasons */ |
| if (strcmp(fileName + len, "/dev") != 0 || len >= PATH_MAX) |
| return FALSE; |
| |
| strcpy(scratch, fileName); |
| scratch[len] = '\0'; |
| make_device(/*DEVNAME:*/ NULL, scratch, OP_add); |
| |
| return TRUE; |
| } |
| |
| /* Directory callback for /sys/ traversal */ |
| static int FAST_FUNC dirAction(const char *fileName UNUSED_PARAM, |
| struct stat *statbuf UNUSED_PARAM, |
| 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); |
| } |
| |
| /* For the full gory details, see linux/Documentation/firmware_class/README |
| * |
| * Firmware loading works like this: |
| * - kernel sets FIRMWARE env var |
| * - userspace checks /lib/firmware/$FIRMWARE |
| * - userspace waits for /sys/$DEVPATH/loading to appear |
| * - userspace writes "1" to /sys/$DEVPATH/loading |
| * - userspace copies /lib/firmware/$FIRMWARE into /sys/$DEVPATH/data |
| * - userspace writes "0" (worked) or "-1" (failed) to /sys/$DEVPATH/loading |
| * - kernel loads firmware into device |
| */ |
| static void load_firmware(const char *firmware, const char *sysfs_path) |
| { |
| int cnt; |
| int firmware_fd, loading_fd; |
| |
| /* check for /lib/firmware/$FIRMWARE */ |
| xchdir("/lib/firmware"); |
| firmware_fd = open(firmware, O_RDONLY); /* can fail */ |
| |
| /* check for /sys/$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 >= 0) |
| goto loading; |
| sleep(1); |
| } |
| goto out; |
| |
| loading: |
| cnt = 0; |
| if (firmware_fd >= 0) { |
| int data_fd; |
| |
| /* tell kernel we're loading by "echo 1 > /sys/$DEVPATH/loading" */ |
| if (full_write(loading_fd, "1", 1) != 1) |
| goto out; |
| |
| /* load firmware into /sys/$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" |
| * 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); |
| } |
| } |
| |
| 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' || seqbuf[0] == '\0') { |
| /* 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); |
| } |
| } |
| } |
| |
| int mdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int mdev_main(int argc UNUSED_PARAM, char **argv) |
| { |
| 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 */ |
| bb_sanitize_stdio(); |
| |
| /* Force the configuration file settings exactly */ |
| umask(0); |
| |
| xchdir("/dev"); |
| |
| 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); |
| 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, |
| * not real directories. |
| * (kernel's CONFIG_SYSFS_DEPRECATED makes them real dirs, |
| * but we can't enforce that on users) |
| */ |
| if (access("/sys/class/block", F_OK) != 0) { |
| /* Scan obsolete /sys/block only if /sys/class/block |
| * doesn't exist. Otherwise we'll have dupes. |
| * Also, do not complain if it doesn't exist. |
| * Some people configure kernel to have no blockdevs. |
| */ |
| recursive_action("/sys/block", |
| ACTION_RECURSE | ACTION_FOLLOWLINKS | ACTION_QUIET, |
| fileAction, dirAction, temp, 0); |
| } |
| recursive_action("/sys/class", |
| ACTION_RECURSE | ACTION_FOLLOWLINKS, |
| fileAction, dirAction, temp, 0); |
| } else { |
| char *fw; |
| char *seq; |
| char *action; |
| char *env_devname; |
| char *env_devpath; |
| unsigned my_pid; |
| int seq_fd; |
| smalluint op; |
| |
| /* Hotplug: |
| * 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_devpath = getenv("DEVPATH"); |
| if (!action || !env_devpath /*|| !G.subsystem*/) |
| bb_show_usage(); |
| fw = getenv("FIRMWARE"); |
| seq = getenv("SEQNUM"); |
| op = index_in_strings(keywords, action); |
| |
| 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) { |
| if (op == OP_add && fw) |
| load_firmware(fw, temp); |
| } |
| } |
| |
| 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 EXIT_SUCCESS; |
| } |