From: Denys Vlasenko Date: Fri, 2 Apr 2010 04:47:14 +0000 (+0200) Subject: mdev: add "!" syntax support X-Git-Tag: 1_17_0~332 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b38af7bd31d98dd6e849354ee94ebafe580e7cc1;p=platform%2Fupstream%2Fbusybox.git mdev: add "!" syntax support Based on the patch by Steve Bennett function old new delta make_device 1640 1673 +33 Signed-off-by: Denys Vlasenko --- 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 @@ device nodes if your system needs something more than the default root/root 660 permissions. The file has the format: - : - or @ : + : + or @ : For example: hd[a-z][0-9]* 0:3 660 @@ -63,7 +63,7 @@ create your own total match like so: .* 1:1 777 You can rename/move device nodes by using the next optional field. - : [=path] + : [=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 @@ This will rename "hdb" to "cdrom". 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: - : [=path] [@|$|*] + : [=path] [@|$|*] + or + : [>path] [@|$|*] or - : [>path] [@|$|*] + : [!] [@|$|*] 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 @@ static void make_device(char *path, int delete) 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 @@ static void make_device(char *path, int delete) /* 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 @@ static void make_device(char *path, int delete) 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; - - a = val; - s = strchrnul(val, ' '); - st = strchrnul(val, '\t'); - if (st < s) - s = st; - val = (s[0] && s[1]) ? s+1 : NULL; + 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; @@ -323,8 +331,13 @@ static void make_device(char *path, int delete) /* 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 @@ static void make_device(char *path, int delete) free(command); } - if (delete) { + if (delete && major >= 0) { if (ENABLE_FEATURE_MDEV_RENAME && alias) { if (aliaslink == '>') unlink(device_name);