debloat and reorganize code

split app into procd and init binaries
remove log support, this is an external service now

Signed-off-by: John Crispin <blogic@openwrt.org>

1 files changed, 264 insertions, 0 deletions

diff --git a/plug/udevtrigger.c b/plug/udevtrigger.c
new file mode 100644
index 0000000..5013189
--- /dev/null
+++ b/plug/udevtrigger.c
@@ -0,0 +1,264 @@
+/*
+ * Copyright (C) 2004-2006 Kay Sievers <kay@vrfy.org>
+ * Copyright (C) 2006 Hannes Reinecke <hare@suse.de>
+ *
+ *	This program is free software; you can redistribute it and/or modify it
+ *	under the terms of the GNU General Public License as published by the
+ *	Free Software Foundation version 2 of the License.
+ *
+ *	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.
+ *
+ *	You should have received a copy of the GNU General Public License along
+ *	with this program; if not, write to the Free Software Foundation, Inc.,
+ *	51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+
+#include <stdlib.h>
+#include <stddef.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <errno.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <syslog.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <string.h>
+
+#define PATH_SIZE 512
+
+#ifndef strlcpy
+#define strlcpy(d,s,l) (strncpy(d,s,l), (d)[(l)-1] = '\0')
+#endif
+
+#ifndef strlcat
+#define strlcat(d,s,l) strncat(d,s,(l)-strlen(d)-1)
+#endif
+
+static int verbose;
+static int dry_run;
+
+static void log_message(int priority, const char *format, ...)
+{
+	va_list args;
+
+	va_start(args, format);
+	vsyslog(priority, format, args);
+	va_end(args);
+}
+
+#undef err
+#define err(format, arg...)                         \
+    do {                                    \
+        log_message(LOG_ERR ,"%s: " format ,__FUNCTION__ ,## arg);  \
+    } while (0)
+
+#undef info
+#define info(format, arg...)                            \
+    do {                                    \
+        log_message(LOG_INFO ,"%s: " format ,__FUNCTION__ ,## arg); \
+    } while (0)
+
+#ifdef DEBUG
+#undef dbg
+#define dbg(format, arg...)                         \
+    do {                                    \
+        log_message(LOG_DEBUG ,"%s: " format ,__FUNCTION__ ,## arg);    \
+    } while (0)
+#else
+#define dbg(...) do {} while(0)
+#endif
+
+
+static void trigger_uevent(const char *devpath)
+{
+	char filename[PATH_SIZE];
+	int fd;
+
+	strlcpy(filename, "/sys", sizeof(filename));
+	strlcat(filename, devpath, sizeof(filename));
+	strlcat(filename, "/uevent", sizeof(filename));
+
+	if (verbose)
+		printf("%s\n", devpath);
+
+	if (dry_run)
+		return;
+
+	fd = open(filename, O_WRONLY);
+	if (fd < 0) {
+		dbg("error on opening %s: %s\n", filename, strerror(errno));
+		return;
+	}
+
+	if (write(fd, "add", 3) < 0)
+		info("error on triggering %s: %s\n", filename, strerror(errno));
+
+	close(fd);
+}
+
+static int sysfs_resolve_link(char *devpath, size_t size)
+{
+	char link_path[PATH_SIZE];
+	char link_target[PATH_SIZE];
+	int len;
+	int i;
+	int back;
+
+	strlcpy(link_path, "/sys", sizeof(link_path));
+	strlcat(link_path, devpath, sizeof(link_path));
+	len = readlink(link_path, link_target, sizeof(link_target));
+	if (len <= 0)
+		return -1;
+	link_target[len] = '\0';
+	dbg("path link '%s' points to '%s'", devpath, link_target);
+
+	for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++)
+		;
+	dbg("base '%s', tail '%s', back %i", devpath, &link_target[back * 3], back);
+	for (i = 0; i <= back; i++) {
+		char *pos = strrchr(devpath, '/');
+
+		if (pos == NULL)
+			return -1;
+		pos[0] = '\0';
+	}
+	dbg("after moving back '%s'", devpath);
+	strlcat(devpath, "/", size);
+	strlcat(devpath, &link_target[back * 3], size);
+	return 0;
+}
+
+static bool device_has_attribute(const char *path, const char *attr,
+				 mode_t mode)
+{
+	char filename[PATH_SIZE];
+	struct stat statbuf;
+
+	strlcpy(filename, path, sizeof(filename));
+	strlcat(filename, attr, sizeof(filename));
+
+	if (stat(filename, &statbuf) < 0)
+		return false;
+
+	if (!(statbuf.st_mode & mode))
+		return false;
+
+	return true;
+}
+
+static int device_list_insert(const char *path)
+{
+	char devpath[PATH_SIZE];
+	struct stat statbuf;
+
+	dbg("add '%s'" , path);
+
+	/* we only have a device, if we have a dev and an uevent file */
+	if (!device_has_attribute(path, "/dev", S_IRUSR) ||
+	    !device_has_attribute(path, "/uevent", S_IWUSR))
+		return -1;
+
+	strlcpy(devpath, &path[4], sizeof(devpath));
+
+	/* resolve possible link to real target */
+	if (lstat(path, &statbuf) < 0)
+		return -1;
+	if (S_ISLNK(statbuf.st_mode))
+		if (sysfs_resolve_link(devpath, sizeof(devpath)) != 0)
+			return -1;
+
+	trigger_uevent(devpath);
+	return 0;
+}
+
+static void scan_subdir(const char *base, const char *subdir,
+		        bool insert, int depth)
+{
+	DIR *dir;
+	struct dirent *dent;
+
+	dir = opendir(base);
+	if (dir == NULL)
+		return;
+
+	for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
+		char dirname[PATH_SIZE];
+
+		if (dent->d_name[0] == '.')
+			continue;
+
+		strlcpy(dirname, base, sizeof(dirname));
+		strlcat(dirname, "/", sizeof(dirname));
+		strlcat(dirname, dent->d_name, sizeof(dirname));
+
+		if (insert) {
+			int err;
+
+			err = device_list_insert(dirname);
+			if (err)
+				continue;
+		}
+
+		if (subdir)
+			strlcat(dirname, subdir, sizeof(base));
+
+		if (depth)
+			scan_subdir(dirname, NULL, true, depth - 1);
+	}
+
+	closedir(dir);
+}
+
+int main(int argc, char *argv[], char *envp[])
+{
+	struct stat statbuf;
+	int option;
+
+	openlog("udevtrigger", LOG_PID | LOG_CONS, LOG_DAEMON);
+
+	while (1) {
+		option = getopt(argc, argv, "vnh");
+		if (option == -1)
+			break;
+
+		switch (option) {
+		case 'v':
+			verbose = 1;
+			break;
+		case 'n':
+			dry_run = 1;
+			break;
+		case 'h':
+			printf("Usage: udevtrigger OPTIONS\n"
+			       "  -v                     print the list of devices while running\n"
+			       "  -n                     do not actually trigger the events\n"
+			       "  -h                     print this text\n"
+			       "\n");
+			goto exit;
+		default:
+			goto exit;
+		}
+	}
+
+
+	/* if we have /sys/subsystem, forget all the old stuff */
+	scan_subdir("/sys/bus", "/devices", false, 1);
+	scan_subdir("/sys/class", NULL, false, 1);
+
+	/* scan "block" if it isn't a "class" */
+	if (stat("/sys/class/block", &statbuf) != 0)
+		scan_subdir("/sys/block", NULL, true, 1);
+
+exit:
+
+	closelog();
+	return 0;
+}