summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--fs/cifs/link.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 473ca8033656..12eb491d4c52 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -28,6 +28,68 @@
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
+#include "md5.h"
+
+#define CIFS_MF_SYMLINK_LEN_OFFSET (4+1)
+#define CIFS_MF_SYMLINK_MD5_OFFSET (CIFS_MF_SYMLINK_LEN_OFFSET+(4+1))
+#define CIFS_MF_SYMLINK_LINK_OFFSET (CIFS_MF_SYMLINK_MD5_OFFSET+(32+1))
+#define CIFS_MF_SYMLINK_LINK_MAXLEN (1024)
+#define CIFS_MF_SYMLINK_FILE_SIZE \
+ (CIFS_MF_SYMLINK_LINK_OFFSET + CIFS_MF_SYMLINK_LINK_MAXLEN)
+
+#define CIFS_MF_SYMLINK_LEN_FORMAT "XSym\n%04u\n"
+#define CIFS_MF_SYMLINK_MD5_FORMAT \
+ "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x\n"
+#define CIFS_MF_SYMLINK_MD5_ARGS(md5_hash) \
+ md5_hash[0], md5_hash[1], md5_hash[2], md5_hash[3], \
+ md5_hash[4], md5_hash[5], md5_hash[6], md5_hash[7], \
+ md5_hash[8], md5_hash[9], md5_hash[10], md5_hash[11],\
+ md5_hash[12], md5_hash[13], md5_hash[14], md5_hash[15]
+
+static int
+CIFSParseMFSymlink(const u8 *buf,
+ unsigned int buf_len,
+ unsigned int *_link_len,
+ char **_link_str)
+{
+ int rc;
+ unsigned int link_len;
+ const char *md5_str1;
+ const char *link_str;
+ struct MD5Context md5_ctx;
+ u8 md5_hash[16];
+ char md5_str2[34];
+
+ if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
+ return -EINVAL;
+
+ md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
+ link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];
+
+ rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
+ if (rc != 1)
+ return -EINVAL;
+
+ cifs_MD5_init(&md5_ctx);
+ cifs_MD5_update(&md5_ctx, (const u8 *)link_str, link_len);
+ cifs_MD5_final(md5_hash, &md5_ctx);
+
+ snprintf(md5_str2, sizeof(md5_str2),
+ CIFS_MF_SYMLINK_MD5_FORMAT,
+ CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));
+
+ if (strncmp(md5_str1, md5_str2, 17) != 0)
+ return -EINVAL;
+
+ if (_link_str) {
+ *_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
+ if (!*_link_str)
+ return -ENOMEM;
+ }
+
+ *_link_len = link_len;
+ return 0;
+}
int
cifs_hardlink(struct dentry *old_file, struct inode *inode,