ubifs: Add hashes to the tree node cache

As part of the UBIFS authentication support every branch in the index
gets a hash covering the referenced node. To make that happen the tree
node cache needs hashes over the nodes. This patch adds a hash argument
to ubifs_tnc_add() and ubifs_tnc_add_nm(). The hashes are calculated
from the callers of these functions which actually prepare the nodes.
With this patch all the leaf nodes of the index tree get hashes, but
currently nothing is done with these hashes, this is left for a later
patch.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/ubifs/replay.c

@@ -228,7 +228,7 @@ static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r)
 			err = ubifs_tnc_remove_nm(c, &r->key, &r->nm);
 		else
 			err = ubifs_tnc_add_nm(c, &r->key, r->lnum, r->offs,
-					       r->len, &r->nm);
+					       r->len, NULL, &r->nm);
 	} else {
 		if (r->deletion)
 			switch (key_type(c, &r->key)) {
@@ -248,7 +248,7 @@ static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r)
 			}
 		else
 			err = ubifs_tnc_add(c, &r->key, r->lnum, r->offs,
-					    r->len);
+					    r->len, NULL);
 		if (err)
 			return err;
 

fs/ubifs/tnc.c

@@ -2260,13 +2260,14 @@ static int tnc_insert(struct ubifs_info *c, struct ubifs_znode *znode,
  * @lnum: LEB number of node
  * @offs: node offset
  * @len: node length
+ * @hash: The hash over the node
  *
  * This function adds a node with key @key to TNC. The node may be new or it may
  * obsolete some existing one. Returns %0 on success or negative error code on
  * failure.
  */
 int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum,
-		  int offs, int len)
+		  int offs, int len, const u8 *hash)
 {
 	int found, n, err = 0;
 	struct ubifs_znode *znode;
@@ -2281,6 +2282,7 @@ int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum,
 		zbr.lnum = lnum;
 		zbr.offs = offs;
 		zbr.len = len;
+		ubifs_copy_hash(c, hash, zbr.hash);
 		key_copy(c, key, &zbr.key);
 		err = tnc_insert(c, znode, &zbr, n + 1);
 	} else if (found == 1) {
@@ -2291,6 +2293,7 @@ int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum,
 		zbr->lnum = lnum;
 		zbr->offs = offs;
 		zbr->len = len;
+		ubifs_copy_hash(c, hash, zbr->hash);
 	} else
 		err = found;
 	if (!err)
@@ -2392,13 +2395,14 @@ int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key,
  * @lnum: LEB number of node
  * @offs: node offset
  * @len: node length
+ * @hash: The hash over the node
  * @nm: node name
  *
  * This is the same as 'ubifs_tnc_add()' but it should be used with keys which
  * may have collisions, like directory entry keys.
  */
 int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key,
-		     int lnum, int offs, int len,
+		     int lnum, int offs, int len, const u8 *hash,
 		     const struct fscrypt_name *nm)
 {
 	int found, n, err = 0;
@@ -2441,6 +2445,7 @@ int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key,
 			zbr->lnum = lnum;
 			zbr->offs = offs;
 			zbr->len = len;
+			ubifs_copy_hash(c, hash, zbr->hash);
 			goto out_unlock;
 		}
 	}
@@ -2452,6 +2457,7 @@ int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key,
 		zbr.lnum = lnum;
 		zbr.offs = offs;
 		zbr.len = len;
+		ubifs_copy_hash(c, hash, zbr.hash);
 		key_copy(c, key, &zbr.key);
 		err = tnc_insert(c, znode, &zbr, n + 1);
 		if (err)

fs/ubifs/ubifs.h

@@ -747,6 +747,7 @@ struct ubifs_jhead {
  * @lnum: LEB number of the target node (indexing node or data node)
  * @offs: target node offset within @lnum
  * @len: target node length
+ * @hash: the hash of the target node
  */
 struct ubifs_zbranch {
 	union ubifs_key key;
@@ -757,6 +758,7 @@ struct ubifs_zbranch {
 	int lnum;
 	int offs;
 	int len;
+	u8 hash[UBIFS_HASH_ARR_SZ];
 };
 
 /**
@@ -1818,11 +1820,12 @@ int ubifs_tnc_lookup_dh(struct ubifs_info *c, const union ubifs_key *key,
 int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key,
 		     void *node, int *lnum, int *offs);
 int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum,
-		  int offs, int len);
+		  int offs, int len, const u8 *hash);
 int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key,
 		      int old_lnum, int old_offs, int lnum, int offs, int len);
 int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key,
-		     int lnum, int offs, int len, const struct fscrypt_name *nm);
+		     int lnum, int offs, int len, const u8 *hash,
+		     const struct fscrypt_name *nm);
 int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key);
 int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key,
 			const struct fscrypt_name *nm);