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authorDenis Vlasenko2009-04-19 21:37:07 +0000
committerDenis Vlasenko2009-04-19 21:37:07 +0000
commit3798db58cfa0e939d0fc1822c9864355c1422cd0 (patch)
tree99f44bad59ccf82f4c1defa3bd81f09078eea8a0 /util-linux/mdev.c
parentf66fe9af89e3d0f8a92894c59b6808f9202c0e86 (diff)
downloadbusybox-3798db58cfa0e939d0fc1822c9864355c1422cd0.zip
busybox-3798db58cfa0e939d0fc1822c9864355c1422cd0.tar.gz
mdev: support $ENVVAR=regex
Diffstat (limited to 'util-linux/mdev.c')
-rw-r--r--util-linux/mdev.c69
1 files changed, 42 insertions, 27 deletions
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index a3275f8..ea1edcc 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -89,15 +89,11 @@ static char *build_alias(char *alias, const char *device_name)
/* NB: "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;
int major, minor, type, len;
int mode;
- char *dev_maj_min = path + strlen(path);
parser_t *parser;
- /* Force the configuration file settings exactly. */
- umask(0);
-
/* 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.
@@ -105,21 +101,23 @@ static void make_device(char *path, int delete)
*/
major = -1;
if (!delete) {
+ 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';
+ *dev_maj_min = '\0';
if (len < 1) {
if (!ENABLE_FEATURE_MDEV_EXEC)
return;
- /* no "dev" file, so just try to run script */
- *dev_maj_min = '\0';
- } else if (sscanf(dev_maj_min, "%u:%u", &major, &minor) != 2) {
+ /* 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 = bb_basename(path);
+ 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,
@@ -139,9 +137,7 @@ static void make_device(char *path, int delete)
parser = config_open2("/etc/mdev.conf", fopen_for_read);
do {
- regmatch_t off[1 + 9 * ENABLE_FEATURE_MDEV_RENAME_REGEXP];
int keep_matching;
- char *val, *name;
struct bb_uidgid_t ugid;
char *tokens[4];
char *command = NULL;
@@ -156,19 +152,22 @@ static void make_device(char *path, int delete)
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 */
- name = strchr(val, '/') ? path : (char *) device_name;
+ str_to_match = strchr(val, '/') ? path : device_name;
/* Fields: regex uid:gid mode [alias] [cmd] */
- /* 1st field: @<numeric maj,min>... */
if (val[0] == '@') {
- /* @major,minor[-last] */
+ /* @major,minor[-minor2] */
/* (useful when name is ambiguous:
* "/sys/class/usb/lp0" and
* "/sys/class/printer/lp0") */
@@ -182,15 +181,29 @@ static void make_device(char *path, int delete)
) {
continue; /* this line doesn't match */
}
- } else { /* ... or regex to match device name */
+ 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 */
+
+ {
regex_t match;
int result;
- /* Is this it? */
xregcomp(&match, val, REG_EXTENDED);
- result = regexec(&match, name, ARRAY_SIZE(off), off, 0);
+ 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;
@@ -199,17 +212,17 @@ static void make_device(char *path, int delete)
// device_name + off[i].rm_so);
//}
- /* If not this device, skip rest of line */
+ /* 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(name))
+ || ((int)off[0].rm_eo != (int)strlen(str_to_match))
) {
continue; /* this line doesn't match */
}
}
-
- /* This line matches: stop parsing the file after parsing
- * the rest of fields unless keep_matching == 1 */
+ line_matches:
+ /* This line matches. Stop parsing after parsing
+ * the rest the line unless keep_matching == 1 */
/* 2nd field: uid:gid - device ownership */
parse_chown_usergroup_or_die(&ugid, tokens[1]);
@@ -243,7 +256,7 @@ static void make_device(char *path, int delete)
if (*s++ == '%')
n++;
- p = alias = xzalloc(strlen(a) + n * strlen(name));
+ p = alias = xzalloc(strlen(a) + n * strlen(str_to_match));
s = a + 1;
while (*s) {
*p = *s;
@@ -251,7 +264,7 @@ static void make_device(char *path, int delete)
i = (s[1] - '0');
if (i <= 9 && off[i].rm_so >= 0) {
n = off[i].rm_eo - off[i].rm_so;
- strncpy(p, name + off[i].rm_so, n);
+ strncpy(p, str_to_match + off[i].rm_so, n);
p += n - 1;
s++;
}
@@ -447,9 +460,11 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
/* 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) {