New upstream version 1.2.2

[sven/exfatprogs.git] / lib / libexfat.c

diff --git a/lib/libexfat.c b/lib/libexfat.c
index 4fd4ac6686e37dcf8a8aa0b6e5b2e1b7ee8019a5..d7b8344f760e6dd7ca1815029d5f14ef9ae424f2 100644 (file)
--- a/lib/libexfat.c
+++ b/lib/libexfat.c
@@ -412,6 +412,7 @@ int exfat_read_volume_label(struct exfat *exfat)
        __le16 disk_label[VOLUME_LABEL_MAX_LEN];
        struct exfat_lookup_filter filter = {
                .in.type = EXFAT_VOLUME,
+               .in.dentry_count = 0,
                .in.filter = NULL,
        };
 
@@ -453,6 +454,7 @@ int exfat_set_volume_label(struct exfat *exfat, char *label_input)
 
        struct exfat_lookup_filter filter = {
                .in.type = EXFAT_VOLUME,
+               .in.dentry_count = 1,
                .in.filter = NULL,
        };
 
@@ -492,6 +494,167 @@ int exfat_set_volume_label(struct exfat *exfat, char *label_input)
        return err;
 }
 
+static inline void print_guid(const char *msg, const __u8 *guid)
+{
+       exfat_info("%s: %02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\n",
+                       msg,
+                       guid[0], guid[1], guid[2], guid[3],
+                       guid[4], guid[5], guid[5], guid[7],
+                       guid[8], guid[9], guid[10], guid[11],
+                       guid[12], guid[13], guid[14], guid[15]);
+}
+
+static int set_guid(__u8 *guid, const char *input)
+{
+       int i, j, zero_len = 0;
+       int len = strlen(input);
+
+       if (len != VOLUME_GUID_LEN * 2 && len != VOLUME_GUID_LEN * 2 + 4) {
+               exfat_err("invalid format for volume guid\n");
+               return -EINVAL;
+       }
+
+       for (i = 0, j = 0; i < len; i++) {
+               unsigned char ch = input[i];
+
+               if (ch >= '0' && ch <= '9')
+                       ch -= '0';
+               else if (ch >= 'a' && ch <= 'f')
+                       ch -= 'a' - 0xA;
+               else if (ch >= 'A' && ch <= 'F')
+                       ch -= 'A' - 0xA;
+               else if (ch == '-' && len == VOLUME_GUID_LEN * 2 + 4 &&
+                        (i == 8 || i == 13 || i == 18 || i == 23))
+                       continue;
+               else {
+                       exfat_err("invalid character '%c' for volume GUID\n", ch);
+                       return -EINVAL;
+               }
+
+               if (j & 1)
+                       guid[j >> 1] |= ch;
+               else
+                       guid[j >> 1] = ch << 4;
+
+               j++;
+
+               if (ch == 0)
+                       zero_len++;
+       }
+
+       if (zero_len == VOLUME_GUID_LEN * 2) {
+               exfat_err("%s is invalid for volume GUID\n", input);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+int exfat_read_volume_guid(struct exfat *exfat)
+{
+       int err;
+       uint16_t checksum = 0;
+       struct exfat_dentry *dentry;
+       struct exfat_lookup_filter filter = {
+               .in.type = EXFAT_GUID,
+               .in.dentry_count = 1,
+               .in.filter = NULL,
+       };
+
+       err = exfat_lookup_dentry_set(exfat, exfat->root, &filter);
+       if (err)
+               return err;
+
+       dentry = filter.out.dentry_set;
+       exfat_calc_dentry_checksum(dentry, &checksum, true);
+
+       if (cpu_to_le16(checksum) == dentry->dentry.guid.checksum)
+               print_guid("GUID", dentry->dentry.guid.guid);
+       else
+               exfat_info("GUID is corrupted, please delete it or set a new one\n");
+
+       free(dentry);
+
+       return err;
+}
+
+int __exfat_set_volume_guid(struct exfat_dentry *dentry, const char *guid)
+{
+       int err;
+       uint16_t checksum = 0;
+
+       memset(dentry, 0, sizeof(*dentry));
+       dentry->type = EXFAT_GUID;
+
+       err = set_guid(dentry->dentry.guid.guid, guid);
+       if (err)
+               return err;
+
+       exfat_calc_dentry_checksum(dentry, &checksum, true);
+       dentry->dentry.guid.checksum = cpu_to_le16(checksum);
+
+       return 0;
+}
+
+/*
+ * Create/Update/Delete GUID dentry in root directory
+ *
+ * create/update GUID if @guid is not NULL.
+ * delete GUID if @guid is NULL.
+ */
+int exfat_set_volume_guid(struct exfat *exfat, const char *guid)
+{
+       struct exfat_dentry *dentry;
+       struct exfat_dentry_loc loc;
+       int err;
+
+       struct exfat_lookup_filter filter = {
+               .in.type = EXFAT_GUID,
+               .in.dentry_count = 1,
+               .in.filter = NULL,
+       };
+
+       err = exfat_lookup_dentry_set(exfat, exfat->root, &filter);
+       if (!err) {
+               /* GUID entry is found */
+               dentry = filter.out.dentry_set;
+       } else {
+               /* no GUID to delete */
+               if (guid == NULL)
+                       return 0;
+
+               dentry = calloc(1, sizeof(*dentry));
+               if (!dentry)
+                       return -ENOMEM;
+       }
+
+       if (guid) {
+               /* Set GUID */
+               err = __exfat_set_volume_guid(dentry, guid);
+               if (err)
+                       goto out;
+       } else {
+               /* Delete GUID */
+               dentry->type &= ~EXFAT_INVAL;
+       }
+
+       loc.parent = exfat->root;
+       loc.file_offset = filter.out.file_offset;
+       loc.dev_offset = filter.out.dev_offset;
+       err = exfat_add_dentry_set(exfat, &loc, dentry, 1, false);
+       if (!err) {
+               if (guid)
+                       print_guid("new GUID", dentry->dentry.guid.guid);
+               else
+                       exfat_info("GUID is deleted\n");
+       }
+
+out:
+       free(dentry);
+
+       return err;
+}
+
 int exfat_read_sector(struct exfat_blk_dev *bd, void *buf, unsigned int sec_off)
 {
        int ret;