/* vi: set sw=4 ts=4: */
/*
- *
* mdev - Mini udev for busybox
*
* Copyright 2005 Rob Landley <rob@landley.net>
*
* Licensed under GPL version 2, see file LICENSE in this tarball for details.
*/
-
#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 $FIRMWARE)
+ *
+ * If /etc/mdev.conf exists, it may modify /dev/device_name's properties.
+ * /etc/mdev.conf file format:
+ *
+ * [-][subsystem/]device user:grp mode [>|=path] [@|$|*command args...]
+ * [-]@maj,min[-min2] user:grp mode [>|=path] [@|$|*command args...]
+ * [-]$envvar=val user:grp mode [>|=path] [@|$|*command args...]
+ *
+ * Leading minus in 1st field means "don't stop on this line", otherwise
+ * search is stopped after the matching line is encountered.
+ *
+ * The device name or "subsystem/device" combo is matched against 1st field
+ * (which is a regex), or maj,min is matched against 1st field,
+ * or specified environment variable (as regex) is matched against 1st field.
+ *
+ * $envvar=val 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.
+ */
+
struct globals {
int root_major, root_minor;
-};
+ char *subsystem;
+} FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1)
-#define root_major (G.root_major)
-#define root_minor (G.root_minor)
-#define MAX_SYSFS_DEPTH 3 /* prevent infinite loops in /sys symlinks */
+/* Prevent infinite loops in /sys symlinks */
+#define MAX_SYSFS_DEPTH 3
+
+/* We use additional 64+ bytes in make_device() */
+#define SCRATCH_SIZE 80
+
+/* 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 */
+ bb_make_directory(alias, 0755, FILEUTILS_RECUR);
+ *dest = '/';
+ if (dest[1] == '\0') { /* ">bar/" => ">bar/device_name" */
+ dest = alias;
+ alias = concat_path_file(alias, device_name);
+ free(dest);
+ }
+ }
-/* mknod in /dev based on a path like "/sys/block/hda/hda1" */
+ 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 if needed)
+ * path string.
+ * NB2: "mdev -s" may call us many times, do not leak memory/fds!
+ */
static void make_device(char *path, int delete)
{
- const char *device_name;
+ char *device_name, *subsystem_slash_devname;
int major, minor, type, len;
- int mode = 0660;
- uid_t uid = 0;
- gid_t gid = 0;
- char *temp = path + strlen(path);
- char *command = NULL;
+ mode_t mode;
+ parser_t *parser;
/* 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. */
-
+ * because sscanf() will stop at the first nondigit, which \n is.
+ * We also depend on path having writeable space after it.
+ */
+ major = -1;
if (!delete) {
- strcat(path, "/dev");
- len = open_read_close(path, temp + 1, 64);
- *temp++ = 0;
- if (len < 1) return;
+ char *dev_maj_min = path + strlen(path);
+
+ strcpy(dev_maj_min, "/dev");
+ len = open_read_close(path, dev_maj_min + 1, 64);
+ *dev_maj_min = '\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(++dev_maj_min, "%u:%u", &major, &minor) != 2) {
+ major = -1;
+ }
}
/* Determine device name, type, major and minor */
+ device_name = (char*) bb_basename(path);
+ /* 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 && strncmp(G.subsystem, "block", 5) == 0))
+ type = S_IFBLK;
+
+ /* Make path point to "subsystem/device_name" */
+ subsystem_slash_devname = NULL;
+ /* Check for coldplug invocations first */
+ if (strncmp(path, "/sys/block/", 11) == 0) /* legacy case */
+ path += sizeof("/sys/") - 1;
+ else if (strncmp(path, "/sys/class/", 11) == 0)
+ path += sizeof("/sys/class/") - 1;
+ else {
+ /* Example of a hotplug invocation:
+ * SUBSYSTEM="block"
+ * DEVPATH="/sys" + "/devices/virtual/mtd/mtd3/mtdblock3"
+ * ("/sys" is added by mdev_main)
+ * - path does not contain subsystem
+ */
+ subsystem_slash_devname = concat_path_file(G.subsystem, device_name);
+ path = subsystem_slash_devname;
+ }
+
+ /* If we have config file, look up user settings */
+ if (ENABLE_FEATURE_MDEV_CONF)
+ parser = config_open2("/etc/mdev.conf", fopen_for_read);
+
+ do {
+ int keep_matching;
+ struct bb_uidgid_t ugid;
+ char *tokens[4];
+ char *command = NULL;
+ char *alias = NULL;
+ char aliaslink = aliaslink; /* for compiler */
+
+ /* Defaults in case we won't match any line */
+ ugid.uid = ugid.gid = 0;
+ keep_matching = 0;
+ mode = 0660;
+
+ if (ENABLE_FEATURE_MDEV_CONF
+ && config_read(parser, tokens, 4, 3, "# \t", PARSE_NORMAL)
+ ) {
+ char *val;
+ char *str_to_match;
+ regmatch_t off[1 + 9 * ENABLE_FEATURE_MDEV_RENAME_REGEXP];
+
+ val = tokens[0];
+ keep_matching = ('-' == val[0]);
+ val += keep_matching; /* swallow leading dash */
+
+ /* Match against either "subsystem/device_name"
+ * or "device_name" alone */
+ str_to_match = strchr(val, '/') ? path : device_name;
+
+ /* Fields: regex uid:gid mode [alias] [cmd] */
+
+ if (val[0] == '@') {
+ /* @major,minor[-minor2] */
+ /* (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(val, "@%u,%u-%u", &cmaj, &cmin0, &cmin1);
+ if (sc < 1
+ || major != cmaj
+ || (sc == 2 && minor != cmin0)
+ || (sc == 3 && (minor < cmin0 || minor > cmin1))
+ ) {
+ continue; /* this line doesn't match */
+ }
+ goto line_matches;
+ }
+ if (val[0] == '$') {
+ /* regex to match an environment variable */
+ char *eq = strchr(++val, '=');
+ if (!eq)
+ continue;
+ *eq = '\0';
+ str_to_match = getenv(val);
+ if (!str_to_match)
+ continue;
+ str_to_match -= strlen(val) + 1;
+ *eq = '=';
+ }
+ /* else: regex to match [subsystem/]device_name */
- device_name = bb_basename(path);
- type = path[5]=='c' ? S_IFCHR : S_IFBLK;
-
- /* If we have a config file, look up permissions for this device */
-
- if (ENABLE_FEATURE_MDEV_CONF) {
- char *conf, *pos, *end;
- int line, fd;
-
- /* mmap the config file */
- fd = open("/etc/mdev.conf", O_RDONLY);
- if (fd < 0)
- goto end_parse;
- len = xlseek(fd, 0, SEEK_END);
- conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
- close(fd);
- if (!conf)
- goto end_parse;
-
- line = 0;
- /* Loop through lines in mmaped file*/
- for (pos=conf; pos-conf<len;) {
- int field;
- char *end2;
-
- line++;
- /* find end of this line */
- for (end=pos; end-conf<len && *end!='\n'; end++)
- ;
-
- /* Three fields: regex, uid:gid, mode */
- for (field=0; field < (3 + ENABLE_FEATURE_MDEV_EXEC);
- field++)
{
- /* Skip whitespace */
- while (pos<end && isspace(*pos)) pos++;
- if (pos==end || *pos=='#') break;
- for (end2=pos;
- end2<end && !isspace(*end2) && *end2!='#'; end2++)
- ;
-
- if (field == 0) {
- /* Regex to match this device */
-
- char *regex = xstrndup(pos, end2-pos);
- regex_t match;
- regmatch_t off;
- int result;
-
- /* Is this it? */
- xregcomp(&match,regex, REG_EXTENDED);
- result = regexec(&match, device_name, 1, &off, 0);
- regfree(&match);
- free(regex);
-
- /* If not this device, skip rest of line */
- if (result || off.rm_so
- || off.rm_eo != strlen(device_name))
- break;
+ regex_t match;
+ int result;
+
+ xregcomp(&match, val, REG_EXTENDED);
+ result = regexec(&match, str_to_match, ARRAY_SIZE(off), off, 0);
+ regfree(&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 no match, skip rest of line */
+ /* (regexec returns whole pattern as "range" 0) */
+ if (result
+ || off[0].rm_so
+ || ((int)off[0].rm_eo != (int)strlen(str_to_match))
+ ) {
+ continue; /* this line doesn't match */
}
- if (field == 1) {
- /* uid:gid */
-
- char *s, *s2;
-
- /* Find : */
- for (s=pos; s<end2 && *s!=':'; s++)
- ;
- if (s == end2) break;
-
- /* Parse UID */
- uid = strtoul(pos, &s2, 10);
- if (s != s2) {
- struct passwd *pass;
- char *_unam = xstrndup(pos, s-pos);
- pass = getpwnam(_unam);
- free(_unam);
- if (!pass) break;
- uid = pass->pw_uid;
- }
- s++;
- /* parse GID */
- gid = strtoul(s, &s2, 10);
- if (end2 != s2) {
- struct group *grp;
- char *_grnam = xstrndup(s, end2-s);
- grp = getgrnam(_grnam);
- free(_grnam);
- if (!grp) break;
- gid = grp->gr_gid;
+ }
+ line_matches:
+ /* This line matches. Stop parsing after parsing
+ * the rest the line unless keep_matching == 1 */
+
+ /* 2nd field: uid:gid - device ownership */
+ if (get_uidgid(&ugid, tokens[1], 1) == 0)
+ bb_error_msg("unknown user/group %s on line %d", tokens[1], parser->lineno);
+
+ /* 3rd field: mode - device permissions */
+ bb_parse_mode(tokens[2], &mode);
+
+ val = tokens[3];
+ /* 4th field (opt): ">|=alias" or "!" to not create the node */
+
+ if (ENABLE_FEATURE_MDEV_RENAME && val) {
+ char *a, *s, *st;
+
+ a = val;
+ s = strchrnul(val, ' ');
+ st = strchrnul(val, '\t');
+ if (st < s)
+ s = st;
+ st = (s[0] && s[1]) ? s+1 : NULL;
+
+ aliaslink = a[0];
+ if (aliaslink == '!' && s == a+1) {
+ val = st;
+ /* "!": suppress node creation/deletion */
+ major = -1;
+ }
+ else if (aliaslink == '>' || aliaslink == '=') {
+ val = st;
+ s[0] = '\0';
+ if (ENABLE_FEATURE_MDEV_RENAME_REGEXP) {
+ char *p;
+ unsigned i, n;
+
+ /* 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(str_to_match));
+ 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, str_to_match + off[i].rm_so, n);
+ p += n - 1;
+ s++;
+ }
+ }
+ p++;
+ s++;
+ }
+ } else {
+ alias = xstrdup(a + 1);
}
}
- if (field == 2) {
- /* mode */
+ }
+
+ if (ENABLE_FEATURE_MDEV_EXEC && val) {
+ const char *s = "$@*";
+ const char *s2 = strchr(s, val[0]);
- mode = strtoul(pos, &pos, 8);
- if (pos != end2) break;
+ if (!s2) {
+ bb_error_msg("bad line %u", parser->lineno);
+ if (ENABLE_FEATURE_MDEV_RENAME)
+ free(alias);
+ continue;
}
- if (ENABLE_FEATURE_MDEV_EXEC && field == 3) {
- // Command to run
- const char *s = "@$*";
- const char *s2;
- s2 = strchr(s, *pos++);
- if (!s2) {
- // Force error
- field = 1;
- break;
- }
- if ((s2-s+1) & (1<<delete))
- command = xstrndup(pos, end-pos);
+
+ /* Are we running this command now?
+ * Run $cmd on delete, @cmd on create, *cmd on both
+ */
+ if (s2 - s != delete) {
+ /* We are here if: '*',
+ * or: '@' and delete = 0,
+ * or: '$' and delete = 1
+ */
+ command = xstrdup(val + 1);
}
+ }
+ }
- pos = end2;
+ /* End of field parsing */
+
+ /* "Execute" the line we found */
+ {
+ const char *node_name;
+
+ node_name = device_name;
+ if (ENABLE_FEATURE_MDEV_RENAME && alias)
+ node_name = alias = build_alias(alias, device_name);
+
+ if (!delete && major >= 0) {
+ if (mknod(node_name, mode | type, makedev(major, minor)) && errno != EEXIST)
+ bb_perror_msg("can't create '%s'", node_name);
+ if (major == G.root_major && minor == G.root_minor)
+ symlink(node_name, "root");
+ if (ENABLE_FEATURE_MDEV_CONF) {
+ chmod(node_name, mode);
+ chown(node_name, ugid.uid, ugid.gid);
+ }
+ if (ENABLE_FEATURE_MDEV_RENAME && alias) {
+ if (aliaslink == '>')
+ symlink(node_name, device_name);
+ }
}
- /* Did everything parse happily? */
+ if (ENABLE_FEATURE_MDEV_EXEC && command) {
+ /* setenv will leak memory, use putenv/unsetenv/free */
+ char *s = xasprintf("%s=%s", "MDEV", node_name);
+ char *s1 = xasprintf("%s=%s", "SUBSYSTEM", G.subsystem);
+ putenv(s);
+ putenv(s1);
+ if (system(command) == -1)
+ bb_perror_msg("can't run '%s'", command);
+ bb_unsetenv_and_free(s1);
+ bb_unsetenv_and_free(s);
+ free(command);
+ }
- if (field > 2) break;
- if (field) bb_error_msg_and_die("bad line %d",line);
+ if (delete && major >= 0) {
+ if (ENABLE_FEATURE_MDEV_RENAME && alias) {
+ if (aliaslink == '>')
+ unlink(device_name);
+ }
+ unlink(node_name);
+ }
- /* Next line */
- pos = ++end;
+ if (ENABLE_FEATURE_MDEV_RENAME)
+ free(alias);
}
- munmap(conf, len);
- end_parse: /* nothing */ ;
- }
- umask(0);
- if (!delete) {
- if (sscanf(temp, "%d:%d", &major, &minor) != 2) return;
- if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
- bb_perror_msg_and_die("mknod %s", device_name);
+ /* We found matching line.
+ * Stop unless it was prefixed with '-' */
+ if (ENABLE_FEATURE_MDEV_CONF && !keep_matching)
+ break;
- if (major == root_major && minor == root_minor)
- symlink(device_name, "root");
+ /* end of "while line is read from /etc/mdev.conf" */
+ } while (ENABLE_FEATURE_MDEV_CONF);
- if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid);
- }
- if (command) {
- /* setenv will leak memory, so use putenv */
- char *s = xasprintf("MDEV=%s", device_name);
- putenv(s);
- if (system(command) == -1)
- bb_perror_msg_and_die("cannot run %s", command);
- s[4] = '\0';
- unsetenv(s);
- free(s);
- free(command);
- }
- if (delete) unlink(device_name);
+ if (ENABLE_FEATURE_MDEV_CONF)
+ config_close(parser);
+ free(subsystem_slash_devname);
}
/* File callback for /sys/ traversal */
-static int fileAction(const char *fileName, struct stat *statbuf,
- void *userData, int depth)
+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;
+ size_t len = strlen(fileName) - 4; /* can't underflow */
char *scratch = userData;
- if (strcmp(fileName + len, "/dev"))
+ /* 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(scratch, 0);
+ scratch[len] = '\0';
+ make_device(scratch, /*delete:*/ 0);
return TRUE;
}
/* Directory callback for /sys/ traversal */
-static int dirAction(const char *fileName, struct stat *statbuf,
- void *userData, int depth)
+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);
+ G.subsystem = strrchr(fileName, '/');
+ if (G.subsystem)
+ G.subsystem = xstrdup(G.subsystem + 1);
+ }
+
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;
- /* check for $FIRMWARE from kernel */
- /* XXX: dont bother: open(NULL) works same as open("no-such-file")
- * if (!firmware)
- * return;
- */
-
/* check for /lib/firmware/$FIRMWARE */
xchdir("/lib/firmware");
firmware_fd = xopen(firmware, O_RDONLY);
xchdir(sysfs_path);
for (cnt = 0; cnt < 30; ++cnt) {
loading_fd = open("loading", O_WRONLY);
- if (loading_fd == -1)
- sleep(1);
- else
- break;
+ if (loading_fd != -1)
+ goto loading;
+ sleep(1);
}
- if (loading_fd == -1)
- goto out;
+ goto out;
- /* tell kernel we're loading by `echo 1 > /sys/$DEVPATH/loading` */
- if (write(loading_fd, "1", 1) != 1)
+ loading:
+ /* tell kernel we're loading by "echo 1 > /sys/$DEVPATH/loading" */
+ if (full_write(loading_fd, "1", 1) != 1)
goto out;
- /* load firmware by `cat /lib/firmware/$FIRMWARE > /sys/$DEVPATH/data */
+ /* load firmware into /sys/$DEVPATH/data */
data_fd = open("data", O_WRONLY);
if (data_fd == -1)
goto out;
cnt = bb_copyfd_eof(firmware_fd, data_fd);
- /* tell kernel result by `echo [0|-1] > /sys/$DEVPATH/loading` */
+ /* tell kernel result by "echo [0|-1] > /sys/$DEVPATH/loading" */
if (cnt > 0)
- write(loading_fd, "0", 1);
+ full_write(loading_fd, "0", 1);
else
- write(loading_fd, "-1", 2);
+ full_write(loading_fd, "-1", 2);
out:
if (ENABLE_FEATURE_CLEAN_UP) {
}
int mdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int mdev_main(int argc, char **argv)
+int mdev_main(int argc UNUSED_PARAM, char **argv)
{
- char *action;
- char *env_path;
- RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
+ RESERVE_CONFIG_BUFFER(temp, PATH_MAX + SCRATCH_SIZE);
- xchdir("/dev");
+ /* We can be called as hotplug helper */
+ /* Kernel cannot provide suitable stdio fds for us, do it ourself */
+ bb_sanitize_stdio();
- /* Scan */
+ /* Force the configuration file settings exactly */
+ umask(0);
+
+ xchdir("/dev");
- if (argc == 2 && !strcmp(argv[1],"-s")) {
+ if (argv[1] && strcmp(argv[1], "-s") == 0) {
+ /* Scan:
+ * mdev -s
+ */
struct stat st;
xstat("/", &st);
- root_major = major(st.st_dev);
- root_minor = minor(st.st_dev);
-
- recursive_action("/sys/block",
- ACTION_RECURSE | ACTION_FOLLOWLINKS,
- fileAction, dirAction, temp, 0);
-
+ G.root_major = major(st.st_dev);
+ G.root_minor = minor(st.st_dev);
+
+ /* 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);
-
- /* Hotplug */
-
} else {
+ char *fw;
+ char *seq;
+ char *action;
+ char *env_path;
+ static const char keywords[] ALIGN1 = "remove\0add\0";
+ enum { OP_remove = 0, OP_add };
+ smalluint op;
+
+ /* Hotplug:
+ * env ACTION=... DEVPATH=... SUBSYSTEM=... [SEQNUM=...] mdev
+ * ACTION can be "add" or "remove"
+ * DEVPATH is like "/block/sda" or "/class/input/mice"
+ */
action = getenv("ACTION");
env_path = getenv("DEVPATH");
- if (!action || !env_path)
+ G.subsystem = getenv("SUBSYSTEM");
+ if (!action || !env_path /*|| !G.subsystem*/)
bb_show_usage();
+ fw = getenv("FIRMWARE");
+ op = index_in_strings(keywords, action);
+ /* 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 */
+ seq = getenv("SEQNUM");
+ if (seq) {
+ int timeout = 2000 / 32; /* 2000 msec */
+ do {
+ int seqlen;
+ char seqbuf[sizeof(int)*3 + 2];
+
+ seqlen = open_read_close("mdev.seq", seqbuf, sizeof(seqbuf-1));
+ if (seqlen < 0) {
+ seq = NULL;
+ break;
+ }
+ seqbuf[seqlen] = '\0';
+ if (seqbuf[0] == '\n' /* seed file? */
+ || strcmp(seq, seqbuf) == 0 /* correct idx? */
+ ) {
+ break;
+ }
+ usleep(32*1000);
+ } while (--timeout);
+ }
- sprintf(temp, "/sys%s", env_path);
- if (!strcmp(action, "remove"))
- make_device(temp, 1);
- else if (!strcmp(action, "add")) {
- make_device(temp, 0);
+ snprintf(temp, PATH_MAX, "/sys%s", env_path);
+ if (op == OP_remove) {
+ /* Ignoring "remove firmware". It was reported
+ * to happen and to cause erroneous deletion
+ * of device nodes. */
+ if (!fw)
+ make_device(temp, /*delete:*/ 1);
+ }
+ else if (op == OP_add) {
+ make_device(temp, /*delete:*/ 0);
+ if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE) {
+ if (fw)
+ load_firmware(fw, temp);
+ }
+ }
- if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE)
- load_firmware(getenv("FIRMWARE"), temp);
+ if (seq) {
+ xopen_xwrite_close("mdev.seq", utoa(xatou(seq) + 1));
}
}
- if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp);
- return 0;
+ if (ENABLE_FEATURE_CLEAN_UP)
+ RELEASE_CONFIG_BUFFER(temp);
+
+ return EXIT_SUCCESS;
}
projects / oweals / busybox.git / blobdiff