[1/2] batman-adv: properly align tvlv infrastructure
Commit Message
4bytes long members must start at an address multiple of 4
in order to avoid unaligned memory access.
Therefore, the tvlv short type is eliminated in favor of
tvlv long and that distinction removed from the code.
Introduced by 0b6aa0d43767889eeda43a132cf5e73df4e63bf2
"batman-adv: tvlv - basic infrastructure"
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
---
main.c | 91 +++++++++++++++++---------------------------------------------
packet.h | 44 +++++++-----------------------
types.h | 1 -
3 files changed, 33 insertions(+), 103 deletions(-)
Comments
On Sunday, May 26, 2013 06:15:20 Marek Lindner wrote:
> 4bytes long members must start at an address multiple of 4
> in order to avoid unaligned memory access.
>
> Therefore, the tvlv short type is eliminated in favor of
> tvlv long and that distinction removed from the code.
>
> Introduced by 0b6aa0d43767889eeda43a132cf5e73df4e63bf2
> "batman-adv: tvlv - basic infrastructure"
>
> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
> ---
> main.c | 91
> +++++++++++++++++--------------------------------------------- packet.h
> | 44 +++++++-----------------------
> types.h | 1 -
> 3 files changed, 33 insertions(+), 103 deletions(-)
Applied in revision 1ab746a.
Regards,
Marek
On Sunday, May 26, 2013 06:15:21 Marek Lindner wrote:
> 4bytes long members must start at an address multiple of 4
> in order to avoid unaligned memory access.
>
> Introduced by 3de4e64df0f1326db7cc0ef25f5af8522850252d
> "batman-adv: tvlv - convert roaming adv packet to use
> tvlv unicast packets"
>
> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
> ---
> packet.h | 4 +++-
> translation-table.c | 1 +
> 2 files changed, 4 insertions(+), 1 deletion(-)
Applied in revision 05a7111.
Regards,
Marek
@@ -604,12 +604,8 @@ static uint16_t batadv_tvlv_container_list_size(struct batadv_priv *bat_priv)
uint16_t tvlv_len = 0;
hlist_for_each_entry(tvlv, &bat_priv->tvlv.container_list, list) {
- if (tvlv->tvlv_hdr.long_tvlv)
- tvlv_len += sizeof(struct batadv_tvlv_long);
- else
- tvlv_len += sizeof(struct batadv_tvlv_short);
-
- tvlv_len += tvlv->value_len;
+ tvlv_len += sizeof(struct batadv_tvlv_hdr);
+ tvlv_len += tvlv->tvlv_hdr.len;
}
return tvlv_len;
@@ -678,13 +674,11 @@ void batadv_tvlv_container_register(struct batadv_priv *bat_priv,
if (!tvlv_new)
return;
- tvlv_new->value_len = tvlv_value_len;
tvlv_new->tvlv_hdr.version = version;
tvlv_new->tvlv_hdr.type = type;
- if (tvlv_new->value_len > 255)
- tvlv_new->tvlv_hdr.long_tvlv = 1;
+ tvlv_new->tvlv_hdr.len = tvlv_value_len;
- memcpy(tvlv_new + 1, tvlv_value, tvlv_new->value_len);
+ memcpy(tvlv_new + 1, tvlv_value, tvlv_new->tvlv_hdr.len);
INIT_HLIST_NODE(&tvlv_new->list);
atomic_set(&tvlv_new->refcount, 1);
@@ -748,8 +742,7 @@ uint16_t batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv,
int packet_min_len)
{
struct batadv_tvlv_container *tvlv;
- struct batadv_tvlv_short *tvlv_short;
- struct batadv_tvlv_long *tvlv_long;
+ struct batadv_tvlv_hdr *tvlv_hdr;
uint16_t tvlv_value_len;
void *tvlv_value;
bool ret;
@@ -769,20 +762,13 @@ uint16_t batadv_tvlv_container_ogm_append(struct batadv_priv *bat_priv,
tvlv_value = (*packet_buff) + packet_min_len;
hlist_for_each_entry(tvlv, &bat_priv->tvlv.container_list, list) {
- if (tvlv->tvlv_hdr.long_tvlv) {
- tvlv_long = tvlv_value;
- tvlv_long->tvlv_hdr = tvlv->tvlv_hdr;
- tvlv_long->len = htons(tvlv->value_len);
- tvlv_value = tvlv_long + 1;
- } else {
- tvlv_short = tvlv_value;
- tvlv_short->tvlv_hdr = tvlv->tvlv_hdr;
- tvlv_short->len = tvlv->value_len;
- tvlv_value = tvlv_short + 1;
- }
-
- memcpy(tvlv_value, tvlv + 1, tvlv->value_len);
- tvlv_value = (uint8_t *)tvlv_value + tvlv->value_len;
+ tvlv_hdr = tvlv_value;
+ tvlv_hdr->type = tvlv->tvlv_hdr.type;
+ tvlv_hdr->version = tvlv->tvlv_hdr.version;
+ tvlv_hdr->len = htons(tvlv->tvlv_hdr.len);
+ tvlv_value = tvlv_hdr + 1;
+ memcpy(tvlv_value, tvlv + 1, tvlv->tvlv_hdr.len);
+ tvlv_value = (uint8_t *)tvlv_value + tvlv->tvlv_hdr.len;
}
end:
@@ -865,30 +851,16 @@ int batadv_tvlv_containers_process(struct batadv_priv *bat_priv,
void *tvlv_value, uint16_t tvlv_value_len)
{
struct batadv_tvlv_handler *tvlv_handler;
- struct batadv_tvlv_short *tvlv_short;
- struct batadv_tvlv_long *tvlv_long;
struct batadv_tvlv_hdr *tvlv_hdr;
uint16_t tvlv_value_cont_len;
uint8_t cifnotfound = BATADV_TVLV_HANDLER_OGM_CIFNOTFND;
int ret = NET_RX_SUCCESS;
- while (tvlv_value_len >= sizeof(*tvlv_short)) {
+ while (tvlv_value_len >= sizeof(*tvlv_hdr)) {
tvlv_hdr = tvlv_value;
-
- if (tvlv_hdr->long_tvlv) {
- if (sizeof(*tvlv_long) > tvlv_value_len)
- break;
-
- tvlv_long = tvlv_value;
- tvlv_value_cont_len = ntohs(tvlv_long->len);
- tvlv_value = tvlv_long + 1;
- tvlv_value_len -= sizeof(*tvlv_long);
- } else {
- tvlv_short = tvlv_value;
- tvlv_value_cont_len = tvlv_short->len;
- tvlv_value = tvlv_short + 1;
- tvlv_value_len -= sizeof(*tvlv_short);
- }
+ tvlv_value_cont_len = ntohs(tvlv_hdr->len);
+ tvlv_value = tvlv_hdr + 1;
+ tvlv_value_len -= sizeof(*tvlv_hdr);
if (tvlv_value_cont_len > tvlv_value_len)
break;
@@ -1042,8 +1014,7 @@ void batadv_tvlv_unicast_send(struct batadv_priv *bat_priv, uint8_t *src,
void *tvlv_value, uint16_t tvlv_value_len)
{
struct batadv_unicast_tvlv_packet *unicast_tvlv_packet;
- struct batadv_tvlv_short *tvlv_short;
- struct batadv_tvlv_long *tvlv_long;
+ struct batadv_tvlv_hdr *tvlv_hdr;
struct batadv_orig_node *orig_node;
struct sk_buff *skb = NULL;
unsigned char *tvlv_buff;
@@ -1058,11 +1029,7 @@ void batadv_tvlv_unicast_send(struct batadv_priv *bat_priv, uint8_t *src,
if (tvlv_value_len > 255)
tvlv_long_hdr = 1;
- tvlv_len = tvlv_value_len;
- if (tvlv_long_hdr)
- tvlv_len += sizeof(*tvlv_long);
- else
- tvlv_len += sizeof(*tvlv_short);
+ tvlv_len = sizeof(*tvlv_hdr) + tvlv_value_len;
skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + hdr_len + tvlv_len);
if (!skb)
@@ -1076,26 +1043,16 @@ void batadv_tvlv_unicast_send(struct batadv_priv *bat_priv, uint8_t *src,
unicast_tvlv_packet->header.ttl = BATADV_TTL;
unicast_tvlv_packet->reserved = 0;
unicast_tvlv_packet->tvlv_len = htons(tvlv_len);
+ unicast_tvlv_packet->align = 0;
memcpy(unicast_tvlv_packet->src, src, ETH_ALEN);
memcpy(unicast_tvlv_packet->dst, dst, ETH_ALEN);
tvlv_buff = (unsigned char *)(unicast_tvlv_packet + 1);
-
- if (tvlv_long_hdr) {
- tvlv_long = (struct batadv_tvlv_long *)tvlv_buff;
- tvlv_long->tvlv_hdr.version = version;
- tvlv_long->tvlv_hdr.type = type;
- tvlv_long->tvlv_hdr.long_tvlv = 1;
- tvlv_long->len = htons(tvlv_value_len);
- tvlv_buff += sizeof(*tvlv_long);
- } else {
- tvlv_short = (struct batadv_tvlv_short *)tvlv_buff;
- tvlv_short->tvlv_hdr.version = version;
- tvlv_short->tvlv_hdr.type = type;
- tvlv_short->len = tvlv_value_len;
- tvlv_buff += sizeof(*tvlv_short);
- }
-
+ tvlv_hdr = (struct batadv_tvlv_hdr *)tvlv_buff;
+ tvlv_hdr->version = version;
+ tvlv_hdr->type = type;
+ tvlv_hdr->len = htons(tvlv_value_len);
+ tvlv_buff += sizeof(*tvlv_hdr);
memcpy(tvlv_buff, tvlv_value, tvlv_value_len);
if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
@@ -327,53 +327,27 @@ struct batadv_coded_packet {
* @src: address of the source
* @dst: address of the destination
* @tvlv_len: length of tvlv data following the unicast tvlv header
+ * @align: 2 bytes to align the header to a 4 byte boundry
*/
struct batadv_unicast_tvlv_packet {
struct batadv_header header;
- uint8_t reserved;
- uint8_t dst[ETH_ALEN];
- uint8_t src[ETH_ALEN];
- __be16 tvlv_len;
+ uint8_t reserved;
+ uint8_t dst[ETH_ALEN];
+ uint8_t src[ETH_ALEN];
+ __be16 tvlv_len;
+ uint16_t align;
};
/**
* struct batadv_tvlv_hdr - base tvlv header struct
- * @long_tvlv: flag indicating whether this is a short tvlv container (max 256
- * bytes) or a long tvlv one (up to ETH_DATA_LEN)
* @type: tvlv container type (see batadv_tvlv_type)
* @version: tvlv container version
+ * @len: tvlv container length
*/
struct batadv_tvlv_hdr {
-#if defined(__BIG_ENDIAN_BITFIELD)
- uint8_t long_tvlv:1;
- uint8_t type:7;
-#elif defined(__LITTLE_ENDIAN_BITFIELD)
- uint8_t type:7;
- uint8_t long_tvlv:1;
-#else
-#error "unknown bitfield endianess"
-#endif
+ uint8_t type;
uint8_t version;
-};
-
-/**
- * struct batadv_tvlv_short - short tvlv header struct
- * @tvlv_hdr: base tvlv header
- * @len: tvlv container length (limited to 255 bytes)
- */
-struct batadv_tvlv_short {
- struct batadv_tvlv_hdr tvlv_hdr;
- uint8_t len;
-};
-
-/**
- * struct batadv_tvlv_long - long tvlv header struct
- * @tvlv_hdr: base tvlv header
- * @len: tvlv container length
- */
-struct batadv_tvlv_long {
- struct batadv_tvlv_hdr tvlv_hdr;
- __be16 len;
+ __be16 len;
};
/**
@@ -976,7 +976,6 @@ struct batadv_dat_candidate {
struct batadv_tvlv_container {
struct hlist_node list;
struct batadv_tvlv_hdr tvlv_hdr;
- uint16_t value_len;
atomic_t refcount;
};