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Diffstat (limited to 'util-linux/mdev.c')
-rw-r--r--util-linux/mdev.c140
1 files changed, 69 insertions, 71 deletions
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 5a8f1d918..f86ce14ce 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -21,7 +21,11 @@ struct globals {
#define MAX_SYSFS_DEPTH 3 /* prevent infinite loops in /sys symlinks */
+/* We use additional 64+ bytes in make_device() */
+#define SCRATCH_SIZE 80
+
/* mknod in /dev based on a path like "/sys/block/hda/hda1" */
+/* 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;
@@ -29,7 +33,7 @@ static void make_device(char *path, int delete)
int mode = 0660;
uid_t uid = 0;
gid_t gid = 0;
- char *temp = path + strlen(path);
+ char *dev_maj_min = path + strlen(path);
char *command = NULL;
char *alias = NULL;
@@ -42,21 +46,20 @@ static void make_device(char *path, int delete)
* also depend on path having writeable space after it.
*/
if (!delete) {
- strcat(path, "/dev");
- len = open_read_close(path, temp + 1, 64);
- *temp++ = 0;
+ 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)
- /* no "dev" file, so just try to run script */
- *temp = 0;
- else
+ if (!ENABLE_FEATURE_MDEV_EXEC)
return;
+ /* no "dev" file, so just try to run script */
+ *dev_maj_min = '\0';
}
}
/* Determine device name, type, major and minor */
device_name = bb_basename(path);
- type = (path[5] == 'c' ? S_IFCHR : S_IFBLK);
+ type = (path[5] == 'c' ? S_IFCHR : S_IFBLK); /* "/sys/[c]lass"? */
if (ENABLE_FEATURE_MDEV_CONF) {
FILE *fp;
@@ -70,15 +73,18 @@ static void make_device(char *path, int delete)
while ((vline = line = xmalloc_fgetline(fp)) != NULL) {
int field;
-
- /* A pristine copy for command execution. */
char *orig_line;
+
if (ENABLE_FEATURE_MDEV_EXEC)
- orig_line = xstrdup(line);
+ orig_line = xstrdup(line); /* pristine copy for command execution. */
++lineno;
- /* Three fields: regex, uid:gid, mode */
+// TODO: get rid of loop,
+// just linear skip_whitespace() style code will do!
+// (will also get rid of orig_line).
+
+ /* Fields: regex uid:gid mode [alias] [cmd] */
for (field = 0; field < (3 + ENABLE_FEATURE_MDEV_RENAME + ENABLE_FEATURE_MDEV_EXEC); ++field) {
/* Find a non-empty field */
@@ -117,9 +123,9 @@ static void make_device(char *path, int delete)
struct group *grp;
char *str_uid = val;
- char *str_gid = strchr(val, ':');
- if (str_gid)
- *str_gid = '\0', ++str_gid;
+ char *str_gid = strchrnul(val, ':');
+ if (*str_gid)
+ *str_gid++ = '\0';
/* Parse UID */
pass = getpwnam(str_uid);
@@ -128,7 +134,7 @@ static void make_device(char *path, int delete)
else
uid = strtoul(str_uid, NULL, 10);
- /* parse GID */
+ /* Parse GID */
grp = getgrnam(str_gid);
if (grp)
gid = grp->gr_gid;
@@ -144,8 +150,10 @@ static void make_device(char *path, int delete)
if (*val != '>')
++field;
- else
+ else {
+ free(alias); /* don't leak in case we matched it on prev line */
alias = xstrdup(val + 1);
+ }
}
@@ -162,12 +170,17 @@ static void make_device(char *path, int delete)
}
/* Correlate the position in the "@$*" with the delete
- * step so that we get the proper behavior.
+ * step so that we get the proper behavior:
+ * @cmd: run on create
+ * $cmd: run on delete
+ * *cmd: run on both
*/
- if ((s2 - s + 1) & (1 << delete))
+ if ((s2 - s + 1) /*1/2/3*/ & /*1/2*/ (1 + delete)) {
+ free(command); /* don't leak in case we matched it on prev line */
command = xstrdup(orig_line + (val + 1 - line));
+ }
}
- }
+ } /* end of "for every field" */
/* Did everything parse happily? */
if (field <= 2)
@@ -177,21 +190,13 @@ static void make_device(char *path, int delete)
free(line);
if (ENABLE_FEATURE_MDEV_EXEC)
free(orig_line);
- }
-
- if (ENABLE_FEATURE_CLEAN_UP)
- fclose(fp);
+ } /* end of "while line is read from /etc/mdev.conf" */
- end_parse: /* nothing */ ;
+ fclose(fp);
}
+ end_parse:
- if (!delete) {
- if (sscanf(temp, "%d:%d", &major, &minor) != 2) {
- if (ENABLE_FEATURE_MDEV_EXEC)
- goto skip_creation;
- else
- return;
- }
+ if (!delete && sscanf(dev_maj_min, "%u:%u", &major, &minor) == 2) {
if (ENABLE_FEATURE_MDEV_RENAME)
unlink(device_name);
@@ -208,39 +213,39 @@ static void make_device(char *path, int delete)
if (ENABLE_FEATURE_MDEV_RENAME && alias) {
char *dest;
- temp = strrchr(alias, '/');
- if (temp) {
- if (temp[1] != '\0')
+ dest = strrchr(alias, '/');
+ if (dest) {
+ if (dest[1] != '\0')
/* given a file name, so rename it */
- *temp = '\0';
+ *dest = '\0';
bb_make_directory(alias, 0755, FILEUTILS_RECUR);
dest = concat_path_file(alias, device_name);
+ free(alias);
} else
dest = alias;
- rename(device_name, dest); // TODO: xrename?
+ rename(device_name, dest);
symlink(dest, device_name);
- if (alias != dest)
- free(alias);
free(dest);
}
}
- skip_creation: /* nothing */ ;
}
+
if (ENABLE_FEATURE_MDEV_EXEC && command) {
- /* setenv will leak memory, so use putenv */
+ /* setenv will leak memory, use putenv/unsetenv/free */
char *s = xasprintf("MDEV=%s", device_name);
putenv(s);
if (system(command) == -1)
- bb_perror_msg_and_die("cannot run %s", command);
+ bb_perror_msg_and_die("can't run '%s'", command);
s[4] = '\0';
unsetenv(s);
free(s);
free(command);
}
+
if (delete)
- remove_file(device_name, FILEUTILS_FORCE);
+ unlink(device_name);
}
/* File callback for /sys/ traversal */
@@ -249,14 +254,15 @@ static int fileAction(const char *fileName,
void *userData,
int depth ATTRIBUTE_UNUSED)
{
- 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") || len >= PATH_MAX)
return FALSE;
strcpy(scratch, fileName);
- scratch[len] = 0;
+ scratch[len] = '\0';
make_device(scratch, 0);
return TRUE;
@@ -287,12 +293,6 @@ static void load_firmware(const char *const firmware, const char *const sysfs_pa
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);
@@ -304,16 +304,15 @@ static void load_firmware(const char *const firmware, const char *const sysfs_pa
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;
+ loading:
/* tell kernel we're loading by `echo 1 > /sys/$DEVPATH/loading` */
- if (write(loading_fd, "1", 1) != 1)
+ if (full_write(loading_fd, "1", 1) != 1)
goto out;
/* load firmware by `cat /lib/firmware/$FIRMWARE > /sys/$DEVPATH/data */
@@ -324,9 +323,9 @@ static void load_firmware(const char *const firmware, const char *const sysfs_pa
/* tell kernel result by `echo [0|-1] > /sys/$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) {
@@ -341,16 +340,14 @@ int mdev_main(int argc, char **argv)
{
char *action;
char *env_path;
- RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
+ RESERVE_CONFIG_BUFFER(temp, PATH_MAX + SCRATCH_SIZE);
xchdir("/dev");
- if (argc == 2 && !strcmp(argv[1],"-s")) {
-
+ if (argc == 2 && !strcmp(argv[1], "-s")) {
/* Scan:
* mdev -s
*/
-
struct stat st;
xstat("/", &st);
@@ -366,26 +363,27 @@ int mdev_main(int argc, char **argv)
fileAction, dirAction, temp, 0);
} else {
-
/* Hotplug:
* env ACTION=... DEVPATH=... 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)
bb_show_usage();
- sprintf(temp, "/sys%s", env_path);
+ snprintf(temp, PATH_MAX, "/sys%s", env_path);
if (!strcmp(action, "remove"))
make_device(temp, 1);
else if (!strcmp(action, "add")) {
make_device(temp, 0);
- if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE)
- load_firmware(getenv("FIRMWARE"), temp);
+ if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE) {
+ char *fw = getenv("FIRMWARE");
+ if (fw)
+ load_firmware(fw, temp);
+ }
}
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 01:44:36 +0000