batman-adv: include the sync-flags when compute the global/local table CRC

Flags covered by TT_SYNC_MASK are kept in sync among the nodes in the network and therefore they have to be considered while computing the global/local table CRC. In this way a generic originator is able to understand if its table contains the correct flags or not. Bits from 4 to 7 in the TT flags fields are now reserved for "synchronized" flags only. This allows future developers to add more flags of this type without breaking compatibility. It's important to note that not all the remote TT flags are synchronised. This comes from the fact that some flags are used to inject an information once only. Signed-off-by: Antonio Quartulli <antonio@open-mesh.com> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

batman-adv: include the sync-flags when compute the global/local table CRC
Flags covered by TT_SYNC_MASK are kept in sync among the nodes in the network and therefore they have to be considered while computing the global/local table CRC. In this way a generic originator is able to understand if its table contains the correct flags or not. Bits from 4 to 7 in the TT flags fields are now reserved for "synchronized" flags only. This allows future developers to add more flags of this type without breaking compatibility. It's important to note that not all the remote TT flags are synchronised. This comes from the fact that some flags are used to inject an information once only. Signed-off-by: Antonio Quartulli <antonio@open-mesh.com> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Antonio Quartulli · Antonio Quartulli
1 parent 3c4f7ab60c
Showing 3 changed files with 28 additions and 2 deletions Side-by-side Diff
net/batman-adv/packet.h
net/batman-adv/translation-table.c
net/batman-adv/types.h
@@ -110,12 +110,13 @@
  
 /* BATADV_TT_CLIENT flags.
  * Flags from BIT(0) to BIT(7) are sent on the wire, while flags from BIT(8) to
- * BIT(15) are used for local computation only
+ * BIT(15) are used for local computation only.
+ * Flags from BIT(4) to BIT(7) are kept in sync with the rest of the network.
  */
 enum batadv_tt_client_flags {
 	BATADV_TT_CLIENT_DEL     = BIT(0),
 	BATADV_TT_CLIENT_ROAM    = BIT(1),
-	BATADV_TT_CLIENT_WIFI    = BIT(2),
+	BATADV_TT_CLIENT_WIFI    = BIT(4),
 	BATADV_TT_CLIENT_NOPURGE = BIT(8),
 	BATADV_TT_CLIENT_NEW     = BIT(9),
 	BATADV_TT_CLIENT_PENDING = BIT(10),
@@ -1959,6 +1959,7 @@
 	struct batadv_tt_global_entry *tt_global;
 	struct hlist_head *head;
 	uint32_t i, crc_tmp, crc = 0;
+	uint8_t flags;
  
 	for (i = 0; i < hash->size; i++) {
 		head = &hash->table[i];
@@ -1997,6 +1998,13 @@
  
 			crc_tmp = crc32c(0, &tt_common->vid,
 					 sizeof(tt_common->vid));
+
+			/* compute the CRC on flags that have to be kept in sync
+			 * among nodes
+			 */
+			flags = tt_common->flags & BATADV_TT_SYNC_MASK;
+			crc_tmp = crc32c(crc_tmp, &flags, sizeof(flags));
+
 			crc ^= crc32c(crc_tmp, tt_common->addr, ETH_ALEN);
 		}
 		rcu_read_unlock();
@@ -2022,6 +2030,7 @@
 	struct batadv_tt_common_entry *tt_common;
 	struct hlist_head *head;
 	uint32_t i, crc_tmp, crc = 0;
+	uint8_t flags;
  
 	for (i = 0; i < hash->size; i++) {
 		head = &hash->table[i];
@@ -2042,6 +2051,13 @@
  
 			crc_tmp = crc32c(0, &tt_common->vid,
 					 sizeof(tt_common->vid));
+
+			/* compute the CRC on flags that have to be kept in sync
+			 * among nodes
+			 */
+			flags = tt_common->flags & BATADV_TT_SYNC_MASK;
+			crc_tmp = crc32c(crc_tmp, &flags, sizeof(flags));
+
 			crc ^= crc32c(crc_tmp, tt_common->addr, ETH_ALEN);
 		}
 		rcu_read_unlock();
@@ -3523,6 +3539,9 @@
 int batadv_tt_init(struct batadv_priv *bat_priv)
 {
 	int ret;
+
+	/* synchronized flags must be remote */
+	BUILD_BUG_ON(!(BATADV_TT_SYNC_MASK & BATADV_TT_REMOTE_MASK));
  
 	ret = batadv_tt_local_init(bat_priv);
 	if (ret < 0)
@@ -42,6 +42,12 @@
 #define BATADV_TT_REMOTE_MASK	0x00FF
  
 /**
+ * BATADV_TT_SYNC_MASK - bitmask of the flags that need to be kept in sync
+ *  among the nodes. These flags are used to compute the global/local CRC
+ */
+#define BATADV_TT_SYNC_MASK	0x00F0
+
+/**
  * struct batadv_hard_iface_bat_iv - per hard interface B.A.T.M.A.N. IV data
  * @ogm_buff: buffer holding the OGM packet
  * @ogm_buff_len: length of the OGM packet buffer
...	...	@@ -110,12 +110,13 @@
110	110
111	111	/* BATADV_TT_CLIENT flags.
112	112	* Flags from BIT(0) to BIT(7) are sent on the wire, while flags from BIT(8) to
113		- * BIT(15) are used for local computation only
	113	+ * BIT(15) are used for local computation only.
	114	+ * Flags from BIT(4) to BIT(7) are kept in sync with the rest of the network.
114	115	*/
115	116	enum batadv_tt_client_flags {
116	117	BATADV_TT_CLIENT_DEL = BIT(0),
117	118	BATADV_TT_CLIENT_ROAM = BIT(1),
118		- BATADV_TT_CLIENT_WIFI = BIT(2),
	119	+ BATADV_TT_CLIENT_WIFI = BIT(4),
119	120	BATADV_TT_CLIENT_NOPURGE = BIT(8),
120	121	BATADV_TT_CLIENT_NEW = BIT(9),
121	122	BATADV_TT_CLIENT_PENDING = BIT(10),
...	...	@@ -1959,6 +1959,7 @@
1959	1959	struct batadv_tt_global_entry *tt_global;
1960	1960	struct hlist_head *head;
1961	1961	uint32_t i, crc_tmp, crc = 0;
	1962	+ uint8_t flags;
1962	1963
1963	1964	for (i = 0; i < hash->size; i++) {
1964	1965	head = &hash->table[i];
...	...	@@ -1997,6 +1998,13 @@
1997	1998
1998	1999	crc_tmp = crc32c(0, &tt_common->vid,
1999	2000	sizeof(tt_common->vid));
	2001	+
	2002	+ /* compute the CRC on flags that have to be kept in sync
	2003	+ * among nodes
	2004	+ */
	2005	+ flags = tt_common->flags & BATADV_TT_SYNC_MASK;
	2006	+ crc_tmp = crc32c(crc_tmp, &flags, sizeof(flags));
	2007	+
2000	2008	crc ^= crc32c(crc_tmp, tt_common->addr, ETH_ALEN);
2001	2009	}
2002	2010	rcu_read_unlock();
...	...	@@ -2022,6 +2030,7 @@
2022	2030	struct batadv_tt_common_entry *tt_common;
2023	2031	struct hlist_head *head;
2024	2032	uint32_t i, crc_tmp, crc = 0;
	2033	+ uint8_t flags;
2025	2034
2026	2035	for (i = 0; i < hash->size; i++) {
2027	2036	head = &hash->table[i];
...	...	@@ -2042,6 +2051,13 @@
2042	2051
2043	2052	crc_tmp = crc32c(0, &tt_common->vid,
2044	2053	sizeof(tt_common->vid));
	2054	+
	2055	+ /* compute the CRC on flags that have to be kept in sync
	2056	+ * among nodes
	2057	+ */
	2058	+ flags = tt_common->flags & BATADV_TT_SYNC_MASK;
	2059	+ crc_tmp = crc32c(crc_tmp, &flags, sizeof(flags));
	2060	+
2045	2061	crc ^= crc32c(crc_tmp, tt_common->addr, ETH_ALEN);
2046	2062	}
2047	2063	rcu_read_unlock();
...	...	@@ -3523,6 +3539,9 @@
3523	3539	int batadv_tt_init(struct batadv_priv *bat_priv)
3524	3540	{
3525	3541	int ret;
	3542	+
	3543	+ /* synchronized flags must be remote */
	3544	+ BUILD_BUG_ON(!(BATADV_TT_SYNC_MASK & BATADV_TT_REMOTE_MASK));
3526	3545
3527	3546	ret = batadv_tt_local_init(bat_priv);
3528	3547	if (ret < 0)
...	...	@@ -42,6 +42,12 @@
42	42	#define BATADV_TT_REMOTE_MASK 0x00FF
43	43
44	44	/**
	45	+ * BATADV_TT_SYNC_MASK - bitmask of the flags that need to be kept in sync
	46	+ * among the nodes. These flags are used to compute the global/local CRC
	47	+ */
	48	+#define BATADV_TT_SYNC_MASK 0x00F0
	49	+
	50	+/**
45	51	* struct batadv_hard_iface_bat_iv - per hard interface B.A.T.M.A.N. IV data
46	52	* @ogm_buff: buffer holding the OGM packet
47	53	* @ogm_buff_len: length of the OGM packet buffer