add mknod wrapper

1 files changed, 126 insertions, 0 deletions

diff --git a/mkdev.c b/mkdev.c
new file mode 100644
index 0000000..c502f70
--- /dev/null
+++ b/mkdev.c
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define _BSD_SOURCE
+
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <dirent.h>
+#include <limits.h>
+#include <fnmatch.h>
+
+#include "procd.h"
+
+static char **patterns;
+static int n_patterns;
+static char buf[PATH_MAX];
+static char buf2[PATH_MAX];
+static unsigned int mode = 0600;
+
+static bool find_pattern(const char *name)
+{
+	int i;
+
+	for (i = 0; i < n_patterns; i++)
+		if (!fnmatch(patterns[i], name, 0))
+			return true;
+
+	return false;
+}
+
+static void make_dev(const char *path, bool block, int major, int minor)
+{
+	unsigned int _mode = mode | (block ? S_IFBLK : S_IFCHR);
+	DEBUG(2, "Creating %s device %s(%d,%d)\n",
+		block ? "block" : "character",
+		path, major, minor);
+
+	mknod(path, _mode, makedev(major, minor));
+}
+
+static void find_devs(bool block)
+{
+	char *path = block ? "/sys/dev/block" : "/sys/dev/char";
+	struct dirent *dp;
+	DIR *dir;
+
+	dir = opendir(path);
+	if (!dir)
+		return;
+
+	path = buf2 + sprintf(buf2, "%s/", path);
+	while ((dp = readdir(dir)) != NULL) {
+		char *c;
+		int major = 0, minor = 0;
+		int len;
+
+		if (dp->d_type != DT_LNK)
+			continue;
+
+		if (sscanf(dp->d_name, "%d:%d", &major, &minor) != 2)
+			continue;
+
+		strcpy(path, dp->d_name);
+		len = readlink(buf2, buf, sizeof(buf));
+		if (len <= 0)
+			continue;
+
+		buf[len] = 0;
+		if (!find_pattern(buf))
+			continue;
+
+		c = strrchr(buf, '/');
+		if (!c)
+			continue;
+
+		c++;
+		make_dev(c, block, major, minor);
+	}
+	closedir(dir);
+}
+
+static char *add_pattern(const char *name)
+{
+	char *str = malloc(strlen(name) + 2);
+
+	str[0] = '*';
+	strcpy(str + 1, name);
+	return str;
+}
+
+int mkdev(const char *name, int _mode)
+{
+	char *pattern;
+
+	if (chdir("/dev")) {
+		perror("chdir");
+		return 1;
+	}
+
+	pattern = add_pattern(name);
+	patterns = &pattern;
+	mode = _mode;
+	n_patterns = 1;
+	find_devs(true);
+	find_devs(false);
+	chdir("/");
+
+	return 0;
+}