1 files changed, 69 insertions, 0 deletions
diff --git a/devices/paths.c b/devices/paths.c
new file mode 100644
index 0000000..a1df5d2
--- /dev/null
+++ b/devices/paths.c
@@ -0,0 +1,69 @@
+#define _GNU_SOURCE
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "paths.h"
+
+static char *mount_base;
+
+struct device_map {
+	char *dev, *mnt;
+};
+
+#define DEVICE_MAP_SIZE 32
+static struct device_map device_map[DEVICE_MAP_SIZE];
+
+const char *mountpoint_for_device(const char *dev_path)
+{
+	int i;
+	const char *basename;
+
+	/* shorten '/dev/foo' to 'foo' */
+	basename = strrchr(dev_path, '/');
+	if (basename)
+		basename++;
+	else
+		basename = dev_path;
+
+	/* check existing entries in the map */
+	for (i = 0; (i < DEVICE_MAP_SIZE) && device_map[i].dev; i++)
+		if (!strcmp(device_map[i].dev, basename))
+			return device_map[i].mnt;
+
+	if (i == DEVICE_MAP_SIZE)
+		return NULL;
+
+	device_map[i].dev = strdup(dev_path);
+	asprintf(&device_map[i].mnt, "%s/%s", mount_base, basename);
+	return device_map[i].mnt;
+}
+
+char *resolve_path(const char *path, const char *current_mountpoint)
+{
+	char *ret;
+	const char *devpath, *sep;
+
+	sep = strchr(path, ':');
+	if (!sep) {
+		devpath = current_mountpoint;
+		asprintf(&ret, "%s/%s", devpath, path);
+	} else {
+		/* copy just the device name into tmp */
+		char *dev = strndup(path, sep - path);
+		devpath = mountpoint_for_device(dev);
+		asprintf(&ret, "%s/%s", devpath, sep + 1);
+		free(dev);
+	}
+
+	return ret;
+}
+
+void set_mount_base(const char *path)
+{
+	if (mount_base)
+		free(mount_base);
+	mount_base = strdup(path);
+}
+