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-rw-r--r--include/usage.h22
-rw-r--r--util-linux/Config.in27
-rw-r--r--util-linux/mdev.c186
3 files changed, 130 insertions, 105 deletions
diff --git a/include/usage.h b/include/usage.h
index 8defbd1fc..712eede63 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -1799,19 +1799,25 @@ USE_FEATURE_DATE_ISOFMT( \
"\t-s\tScan /sys and populate /dev during system boot\n\n" \
"Called with no options (via hotplug) it uses environment variables\n" \
"to determine which device to add/remove."
-#ifdef CONFIG_FEATURE_MDEV_CONFIG
-#define mdev_notes_usage \
+#define mdev_notes_usage "" \
+USE_FEATURE_MDEV_CONFIG( \
"The mdev config file contains lines that look like:\n" \
" hd[a-z][0-9]* 0:3 660\n\n" \
"That's device name (with regex match), uid:gid, and permissions.\n\n" \
- "Optionally, that can be followed (on the same line) by an asterisk\n" \
- "and a command line to run after creating the corresponding device(s),\n"\
- "ala:\n\n" \
- " hdc root:cdrom 660 *ln -s hdc cdrom\n\n" \
+ USE_FEATURE_MDEV_EXEC( \
+ "Optionally, that can be followed (on the same line) by a special character\n" \
+ "and a command line to run after creating/before deleting the corresponding\n" \
+ "device(s). The environment variable $MDEV indicates the active device node\n" \
+ "(which is useful if it's a regex match). For example:\n\n" \
+ " hdc root:cdrom 660 *ln -s $MDEV cdrom\n\n" \
+ "The special characters are @ (run after creating), $ (run before deleting),\n" \
+ "and * (run both after creating and before deleting). The commands run in\n" \
+ "the /dev directory, and use system() which calls /bin/sh.\n\n" \
+ ) \
"Config file parsing stops on the first matching line. If no config\n"\
"entry is matched, devices are created with default 0:0 660. (Make\n"\
- "the last line match .* to override this.)\n\n"
-#endif
+ "the last line match .* to override this.)\n\n" \
+)
#define mesg_trivial_usage \
"[y|n]"
diff --git a/util-linux/Config.in b/util-linux/Config.in
index a493fbfb4..501ed6bfc 100644
--- a/util-linux/Config.in
+++ b/util-linux/Config.in
@@ -265,16 +265,31 @@ config CONFIG_FEATURE_MDEV_CONF
That's device name (with regex match), uid:gid, and permissions.
- Optionally, that can be followed (on the same line) by an asterisk
- and a command line to run after creating the corresponding device(s),
- ala:
-
- hdc root:cdrom 660 *ln -s hdc cdrom
-
Config file parsing stops on the first matching line. If no config
entry is matched, devices are created with default 0:0 660. (Make
the last line match .* to override this.)
+config CONFIG_FEATURE_MDEV_EXEC
+ bool "Support command execution at device addition/removal"
+ default n
+ depends on CONFIG_FEATURE_MDEV_CONF
+ help
+ This adds support for an optional field to /etc/mdev.conf, consisting
+ of a special character and a command line to run after creating the
+ corresponding device(s) and before removing, ala:
+
+ hdc root:cdrom 660 *ln -s $MDEV cdrom
+
+ The $MDEV environment variable is set to the name of the device.
+
+ The special characters and their meanings are:
+ @ Run after creating the device.
+ $ Run before removing the device.
+ * Run both after creating and before removing the device.
+
+ Commands are executed via system() so you need /bin/sh, meaning you
+ probably want to select a default shell in the Shells menu.
+
config CONFIG_MKSWAP
bool "mkswap"
default n
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 73a82314c..3c7cf7bd1 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -8,25 +8,14 @@
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
+#include "busybox.h"
#include <ctype.h>
-#include <dirent.h>
#include <errno.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <string.h>
#include <sys/mman.h>
-#include <sys/stat.h>
#include <sys/sysmacros.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include "busybox.h"
#include "xregex.h"
#define DEV_PATH "/dev"
-#define MDEV_CONF "/etc/mdev.conf"
-
-#include <busybox.h>
struct mdev_globals
{
@@ -36,14 +25,15 @@ struct mdev_globals
#define bbg mdev_globals
/* mknod in /dev based on a path like "/sys/block/hda/hda1" */
-static void make_device(char *path)
+static void make_device(char *path, int delete)
{
- char *device_name, *s;
+ char *device_name;
int major, minor, type, len, fd;
int mode = 0660;
uid_t uid = 0;
gid_t gid = 0;
char *temp = path + strlen(path);
+ char *command = NULL;
/* 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
@@ -69,7 +59,7 @@ static void make_device(char *path)
char *conf, *pos, *end;
/* mmap the config file */
- if (-1 != (fd=open(MDEV_CONF,O_RDONLY))) {
+ if (-1 != (fd=open("/etc/mdev.conf",O_RDONLY))) {
len = lseek(fd, 0, SEEK_END);
conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
if (conf) {
@@ -86,88 +76,89 @@ static void make_device(char *path)
;
/* Three fields: regex, uid:gid, mode */
- for (field=3; field; field--) {
+ 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++)
+ while (pos<end && isspace(*pos)) pos++;
+ if (pos==end || *pos=='#') break;
+ for (end2=pos;
+ end2<end && !isspace(*end2) && *end2!='#'; end2++)
;
- switch (field) {
+ if (!field) {
/* Regex to match this device */
- case 3:
- {
- char *regex = strndupa(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);
-
- /* If not this device, skip rest of line */
- if (result || off.rm_so || off.rm_eo!=strlen(device_name))
- goto end_line;
+ char *regex = strndupa(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);
+
+ /* If not this device, skip rest of line */
+ if (result || off.rm_so
+ || off.rm_eo != strlen(device_name))
break;
- }
+
+ } else if (field == 1) {
/* uid:gid */
- case 2:
- {
- char *s2;
-
- /* Find : */
- for(s=pos; s<end2 && *s!=':'; s++)
- ;
- if (s == end2)
- goto end_line;
-
- /* Parse UID */
- uid = strtoul(pos,&s2,10);
- if (s != s2) {
- struct passwd *pass;
- pass = getpwnam(strndupa(pos,s-pos));
- if (!pass)
- goto end_line;
- uid = pass->pw_uid;
- }
- s++;
- /* parse GID */
- gid = strtoul(s,&s2,10);
- if (end2 != s2) {
- struct group *grp;
- grp = getgrnam(strndupa(s,end2-s));
- if (!grp)
- goto end_line;
- gid = grp->gr_gid;
- }
- break;
+
+ 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;
+ pass = getpwnam(strndupa(pos, s-pos));
+ if (!pass) break;
+ uid = pass->pw_uid;
+ }
+ s++;
+ /* parse GID */
+ gid = strtoul(s, &s2, 10);
+ if (end2 != s2) {
+ struct group *grp;
+ grp = getgrnam(strndupa(s, end2-s));
+ if (!grp) break;
+ gid = grp->gr_gid;
}
+ } else if (field == 2) {
/* mode */
- case 1:
- {
- mode = strtoul(pos,&pos,8);
- if (pos != end2)
- goto end_line;
- else
- goto found_device;
+
+ mode = strtoul(pos, &pos, 8);
+ if (pos != end2) break;
+ } else if (ENABLE_FEATURE_MDEV_EXEC && field == 3) {
+ // Command to run
+ char *s = "@$*", *s2;
+ if (!(s2 = strchr(s, *pos++))) {
+ // Force error
+ field = 1;
+ break;
}
+ if ((s2-s+1) & (1<<delete))
+ command = bb_xstrndup(pos, end-pos);
}
+
pos = end2;
}
-end_line:
+
/* Did everything parse happily? */
- if (field && field!=3)
- bb_error_msg_and_die("Bad line %d",line);
+
+ if (field > 2) break;
+ if (field) bb_error_msg_and_die("Bad line %d",line);
/* Next line */
pos = ++end;
}
-found_device:
munmap(conf, len);
}
close(fd);
@@ -175,13 +166,29 @@ found_device:
}
umask(0);
- if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
- bb_perror_msg_and_die("mknod %s failed", device_name);
+ if (!delete) {
+ if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
+ bb_perror_msg_and_die("mknod %s failed", device_name);
- if (major==bbg.root_major && minor==bbg.root_minor)
- symlink(device_name, "root");
+ if (major == bbg.root_major && minor == bbg.root_minor)
+ symlink(device_name, "root");
- if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid);
+ if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid);
+ }
+ if (command) {
+ int rc;
+ char *s;
+
+ s=bb_xasprintf("MDEV=%s",device_name);
+ putenv(s);
+ rc = system(command);
+ s[4]=0;
+ putenv(s);
+ free(s);
+ free(command);
+ if (rc == -1) bb_perror_msg_and_die("Couldn't run %s", command);
+ }
+ if (delete) unlink(device_name);
}
/* Recursive search of /sys/block or /sys/class. path must be a writeable
@@ -212,7 +219,7 @@ static void find_dev(char *path)
/* If there's a dev entry, mknod it */
- if (!strcmp(entry->d_name, "dev")) make_device(path);
+ if (!strcmp(entry->d_name, "dev")) make_device(path, 0);
}
closedir(dir);
@@ -247,12 +254,9 @@ int mdev_main(int argc, char *argv[])
if (!action || !env_path)
bb_show_usage();
- if (!strcmp(action, "add")) {
- sprintf(temp, "/sys%s", env_path);
- make_device(temp);
- } else if (!strcmp(action, "remove")) {
- unlink(strrchr(env_path, '/') + 1);
- }
+ sprintf(temp, "/sys%s", env_path);
+ if (!strcmp(action, "add")) make_device(temp,0);
+ else if (!strcmp(action, "remove")) make_device(temp,1);
}
if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-28 10:03:50 +0000