mdev: add "!" syntax support
Based on the patch by Steve Bennett <steveb@workware.net.au>
function old new delta
make_device 1640 1673 +33
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/docs/mdev.txt b/docs/mdev.txt
index 7bd00fe..2d03bd8 100644
--- a/docs/mdev.txt
+++ b/docs/mdev.txt
@@ -51,8 +51,8 @@
660 permissions.
The file has the format:
- <device regex> <uid>:<gid> <octal permissions>
- or @<maj[,min1[-min2]]> <uid>:<gid> <octal permissions>
+ <device regex> <uid>:<gid> <permissions>
+ or @<maj[,min1[-min2]]> <uid>:<gid> <permissions>
For example:
hd[a-z][0-9]* 0:3 660
@@ -63,7 +63,7 @@
.* 1:1 777
You can rename/move device nodes by using the next optional field.
- <device regex> <uid>:<gid> <octal permissions> [=path]
+ <device regex> <uid>:<gid> <permissions> [=path]
So if you want to place the device node into a subdirectory, make sure the path
has a trailing /. If you want to rename the device node, just place the name.
hda 0:3 660 =drives/
@@ -74,11 +74,17 @@
Similarly, ">path" renames/moves the device but it also creates
a direct symlink /dev/DEVNAME to the renamed/moved device.
+You can also prevent creation of device nodes with the 4th field as "!":
+ tty[a-z]. 0:0 660 !
+ pty[a-z]. 0:0 660 !
+
If you also enable support for executing your own commands, then the file has
the format:
- <device regex> <uid>:<gid> <octal permissions> [=path] [@|$|*<command>]
+ <device regex> <uid>:<gid> <permissions> [=path] [@|$|*<command>]
or
- <device regex> <uid>:<gid> <octal permissions> [>path] [@|$|*<command>]
+ <device regex> <uid>:<gid> <permissions> [>path] [@|$|*<command>]
+ or
+ <device regex> <uid>:<gid> <permissions> [!] [@|$|*<command>]
For example:
---8<---
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index b0efd98..2170756 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -204,7 +204,8 @@
if (major < 0)
continue; /* no dev, no match */
sc = sscanf(val, "@%u,%u-%u", &cmaj, &cmin0, &cmin1);
- if (sc < 1 || major != cmaj
+ if (sc < 1
+ || major != cmaj
|| (sc == 2 && minor != cmin0)
|| (sc == 3 && (minor < cmin0 || minor > cmin1))
) {
@@ -243,7 +244,8 @@
/* If no match, skip rest of line */
/* (regexec returns whole pattern as "range" 0) */
- if (result || off[0].rm_so
+ if (result
+ || off[0].rm_so
|| ((int)off[0].rm_eo != (int)strlen(str_to_match))
) {
continue; /* this line doesn't match */
@@ -258,28 +260,34 @@
bb_error_msg("unknown user/group %s on line %d", tokens[1], parser->lineno);
/* 3rd field: mode - device permissions */
- /* mode = strtoul(tokens[2], NULL, 8); */
bb_parse_mode(tokens[2], &mode);
val = tokens[3];
- /* 4th field (opt): >|=alias */
+ /* 4th field (opt): ">|=alias" or "!" to not create the node */
if (ENABLE_FEATURE_MDEV_RENAME && val) {
- aliaslink = val[0];
- if (aliaslink == '>' || aliaslink == '=') {
- char *a, *s, *st;
- char *p;
- unsigned i, n;
+ char *a, *s, *st;
- a = val;
- s = strchrnul(val, ' ');
- st = strchrnul(val, '\t');
- if (st < s)
- s = st;
- val = (s[0] && s[1]) ? s+1 : NULL;
+ 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;
@@ -323,8 +331,13 @@
/* Are we running this command now?
* Run $cmd on delete, @cmd on create, *cmd on both
*/
- if (s2-s != delete)
+ if (s2 - s != delete) {
+ /* We are here if: '*',
+ * or: '@' and delete = 0,
+ * or: '$' and delete = 1
+ */
command = xstrdup(val + 1);
+ }
}
}
@@ -368,7 +381,7 @@
free(command);
}
- if (delete) {
+ if (delete && major >= 0) {
if (ENABLE_FEATURE_MDEV_RENAME && alias) {
if (aliaslink == '>')
unlink(device_name);