1 files changed, 73 insertions, 0 deletions

diff --git a/util-linux/volume_id/linux_swap.c b/util-linux/volume_id/linux_swap.c
new file mode 100644
index 000000000..56b5d5085
--- /dev/null
+++ b/util-linux/volume_id/linux_swap.c
@@ -0,0 +1,73 @@
+/*
+ * volume_id - reads filesystem label and uuid
+ *
+ * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
+ *
+ *      This library is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU Lesser General Public
+ *      License as published by the Free Software Foundation; either
+ *      version 2.1 of the License, or (at your option) any later version.
+ *
+ *      This library 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
+ *      Lesser General Public License for more details.
+ *
+ *      You should have received a copy of the GNU Lesser General Public
+ *      License along with this library; if not, write to the Free Software
+ *      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "volume_id_internal.h"
+
+struct swap_header_v1_2 {
+        uint8_t         bootbits[1024];
+        uint32_t        version;
+        uint32_t        last_page;
+        uint32_t        nr_badpages;
+        uint8_t         uuid[16];
+        uint8_t         volume_name[16];
+} __attribute__((__packed__));
+
+#define LARGEST_PAGESIZE                        0x4000
+
+int volume_id_probe_linux_swap(struct volume_id *id, uint64_t off)
+{
+        struct swap_header_v1_2 *sw;
+        const uint8_t *buf;
+        unsigned page;
+
+        dbg("probing at offset 0x%llx", (unsigned long long) off);
+
+        /* the swap signature is at the end of the PAGE_SIZE */
+        for (page = 0x1000; page <= LARGEST_PAGESIZE; page <<= 1) {
+                        buf = volume_id_get_buffer(id, off + page-10, 10);
+                        if (buf == NULL)
+                                return -1;
+
+                        if (memcmp(buf, "SWAP-SPACE", 10) == 0) {
+                                id->type_version[0] = '1';
+                                id->type_version[1] = '\0';
+                                goto found;
+                        }
+
+                        if (memcmp(buf, "SWAPSPACE2", 10) == 0) {
+                                sw = volume_id_get_buffer(id, off, sizeof(struct swap_header_v1_2));
+                                if (sw == NULL)
+                                        return -1;
+                                id->type_version[0] = '2';
+                                id->type_version[1] = '\0';
+                                volume_id_set_label_raw(id, sw->volume_name, 16);
+                                volume_id_set_label_string(id, sw->volume_name, 16);
+                                volume_id_set_uuid(id, sw->uuid, UUID_DCE);
+                                goto found;
+                        }
+        }
+        return -1;
+
+found:
+        volume_id_set_usage(id, VOLUME_ID_OTHER);
+        id->type = "swap";
+
+        return 0;
+}