Move path maniuplation functions to devices/paths.c

[petitboot] / devices / paths.c

diff --git a/devices/paths.c b/devices/paths.c
new file mode 100644 (file)
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);
+}
+