* [B.A.T.M.A.N.] [PATCHv3 1/2] batman-adv: Check total_size when queueing fragments
@ 2014-12-01 9:37 Sven Eckelmann
2014-12-01 9:37 ` [B.A.T.M.A.N.] [PATCHv3 2/2] batman-adv: Use only queued fragments when merging Sven Eckelmann
2014-12-01 11:38 ` [B.A.T.M.A.N.] [PATCHv3 1/2] batman-adv: Check total_size when queueing fragments Martin Hundebøll
0 siblings, 2 replies; 6+ messages in thread
From: Sven Eckelmann @ 2014-12-01 9:37 UTC (permalink / raw)
To: b.a.t.m.a.n; +Cc: Sven Eckelmann
The fragmentation code was replaced in 9b3eab61754d74a93c9840c296013fe3b4a1b606
("batman-adv: Receive fragmented packets and merge") by an implementation which
handles the queueing+merging of fragments based on their size and the
total_size of the non-fragmented packet. This total_size is announced by each
fragment. The new implementation doesn't check if the the total_size
information of the packets inside one chain is consistent.
This is consistency check is recommended to allow using any of the packets in
the queue to decide whether all fragments of a packet are received or not.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
This is only compile tested
v3.
- withdrawing from inclusion in maint
- remove wrong example from the commit message
v2:
- proposed for maint
- changed commit message slightly
---
fragmentation.c | 7 +++++--
types.h | 2 ++
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/fragmentation.c b/fragmentation.c
index 5251aa1..6e4c957 100644
--- a/fragmentation.c
+++ b/fragmentation.c
@@ -161,6 +161,7 @@ static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node,
hlist_add_head(&frag_entry_new->list, &chain->head);
chain->size = skb->len - hdr_size;
chain->timestamp = jiffies;
+ chain->total_size = ntohs(frag_packet->total_size);
ret = true;
goto out;
}
@@ -195,9 +196,11 @@ static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node,
out:
if (chain->size > batadv_frag_size_limit() ||
- ntohs(frag_packet->total_size) > batadv_frag_size_limit()) {
+ chain->total_size != ntohs(frag_packet->total_size) ||
+ chain->total_size > batadv_frag_size_limit()) {
/* Clear chain if total size of either the list or the packet
- * exceeds the maximum size of one merged packet.
+ * exceeds the maximum size of one merged packet. Don't allow
+ * packets to have different total_size.
*/
batadv_frag_clear_chain(&chain->head);
chain->size = 0;
diff --git a/types.h b/types.h
index 462a70c..c4d7d24 100644
--- a/types.h
+++ b/types.h
@@ -132,6 +132,7 @@ struct batadv_orig_ifinfo {
* @timestamp: time (jiffie) of last received fragment
* @seqno: sequence number of the fragments in the list
* @size: accumulated size of packets in list
+ * @total_size: expected size of the assembled packet
*/
struct batadv_frag_table_entry {
struct hlist_head head;
@@ -139,6 +140,7 @@ struct batadv_frag_table_entry {
unsigned long timestamp;
uint16_t seqno;
uint16_t size;
+ uint16_t total_size;
};
/**
--
2.1.3
^ permalink raw reply related [flat|nested] 6+ messages in thread* [B.A.T.M.A.N.] [PATCHv3 2/2] batman-adv: Use only queued fragments when merging
2014-12-01 9:37 [B.A.T.M.A.N.] [PATCHv3 1/2] batman-adv: Check total_size when queueing fragments Sven Eckelmann
@ 2014-12-01 9:37 ` Sven Eckelmann
2014-12-01 11:40 ` Martin Hundebøll
2014-12-01 11:38 ` [B.A.T.M.A.N.] [PATCHv3 1/2] batman-adv: Check total_size when queueing fragments Martin Hundebøll
1 sibling, 1 reply; 6+ messages in thread
From: Sven Eckelmann @ 2014-12-01 9:37 UTC (permalink / raw)
To: b.a.t.m.a.n; +Cc: Sven Eckelmann
The fragment queueing code now validates the total_size of each fragment,
checks when enough fragments are queued to allow to merge them into a single
packet and if the fragments have the correct size. Therefore, it is not
required to have any other parameter for the merging function than a list of
queued fragments.
This change should avoid problems like in the past when the different skb from
the list and the function parameter were mixed incorrectly.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
fragmentation.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/fragmentation.c b/fragmentation.c
index 6e4c957..0ab228f 100644
--- a/fragmentation.c
+++ b/fragmentation.c
@@ -231,19 +231,13 @@ err:
* Returns the merged skb or NULL on error.
*/
static struct sk_buff *
-batadv_frag_merge_packets(struct hlist_head *chain, struct sk_buff *skb)
+batadv_frag_merge_packets(struct hlist_head *chain)
{
struct batadv_frag_packet *packet;
struct batadv_frag_list_entry *entry;
struct sk_buff *skb_out = NULL;
int size, hdr_size = sizeof(struct batadv_frag_packet);
- /* Make sure incoming skb has non-bogus data. */
- packet = (struct batadv_frag_packet *)skb->data;
- size = ntohs(packet->total_size);
- if (size > batadv_frag_size_limit())
- goto free;
-
/* Remove first entry, as this is the destination for the rest of the
* fragments.
*/
@@ -252,6 +246,9 @@ batadv_frag_merge_packets(struct hlist_head *chain, struct sk_buff *skb)
skb_out = entry->skb;
kfree(entry);
+ packet = (struct batadv_frag_packet *)skb_out->data;
+ size = ntohs(packet->total_size);
+
/* Make room for the rest of the fragments. */
if (pskb_expand_head(skb_out, 0, size - skb_out->len, GFP_ATOMIC) < 0) {
kfree_skb(skb_out);
@@ -307,7 +304,7 @@ bool batadv_frag_skb_buffer(struct sk_buff **skb,
if (hlist_empty(&head))
goto out;
- skb_out = batadv_frag_merge_packets(&head, *skb);
+ skb_out = batadv_frag_merge_packets(&head);
if (!skb_out)
goto out_err;
--
2.1.3
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [B.A.T.M.A.N.] [PATCHv3 2/2] batman-adv: Use only queued fragments when merging
2014-12-01 9:37 ` [B.A.T.M.A.N.] [PATCHv3 2/2] batman-adv: Use only queued fragments when merging Sven Eckelmann
@ 2014-12-01 11:40 ` Martin Hundebøll
2015-01-11 10:29 ` Marek Lindner
0 siblings, 1 reply; 6+ messages in thread
From: Martin Hundebøll @ 2014-12-01 11:40 UTC (permalink / raw)
To: The list for a Better Approach To Mobile Ad-hoc Networking; +Cc: Sven Eckelmann
Hi Sven,
On 2014-12-01 10:37, Sven Eckelmann wrote:
> The fragment queueing code now validates the total_size of each fragment,
> checks when enough fragments are queued to allow to merge them into a single
> packet and if the fragments have the correct size. Therefore, it is not
> required to have any other parameter for the merging function than a list of
> queued fragments.
>
> This change should avoid problems like in the past when the different skb from
> the list and the function parameter were mixed incorrectly.
>
> Signed-off-by: Sven Eckelmann <sven@narfation.org>
> ---
> fragmentation.c | 13 +++++--------
> 1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/fragmentation.c b/fragmentation.c
> index 6e4c957..0ab228f 100644
> --- a/fragmentation.c
> +++ b/fragmentation.c
> @@ -231,19 +231,13 @@ err:
> * Returns the merged skb or NULL on error.
> */
> static struct sk_buff *
> -batadv_frag_merge_packets(struct hlist_head *chain, struct sk_buff *skb)
> +batadv_frag_merge_packets(struct hlist_head *chain)
> {
> struct batadv_frag_packet *packet;
> struct batadv_frag_list_entry *entry;
> struct sk_buff *skb_out = NULL;
> int size, hdr_size = sizeof(struct batadv_frag_packet);
>
> - /* Make sure incoming skb has non-bogus data. */
> - packet = (struct batadv_frag_packet *)skb->data;
> - size = ntohs(packet->total_size);
> - if (size > batadv_frag_size_limit())
> - goto free;
> -
> /* Remove first entry, as this is the destination for the rest of the
> * fragments.
> */
> @@ -252,6 +246,9 @@ batadv_frag_merge_packets(struct hlist_head *chain, struct sk_buff *skb)
> skb_out = entry->skb;
> kfree(entry);
>
> + packet = (struct batadv_frag_packet *)skb_out->data;
> + size = ntohs(packet->total_size);
> +
> /* Make room for the rest of the fragments. */
> if (pskb_expand_head(skb_out, 0, size - skb_out->len, GFP_ATOMIC) < 0) {
> kfree_skb(skb_out);
> @@ -307,7 +304,7 @@ bool batadv_frag_skb_buffer(struct sk_buff **skb,
> if (hlist_empty(&head))
> goto out;
>
> - skb_out = batadv_frag_merge_packets(&head, *skb);
> + skb_out = batadv_frag_merge_packets(&head);
> if (!skb_out)
> goto out_err;
>
>
Acked-by: Martin Hundebøll <martin@hundeboll.net>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [B.A.T.M.A.N.] [PATCHv3 1/2] batman-adv: Check total_size when queueing fragments
2014-12-01 9:37 [B.A.T.M.A.N.] [PATCHv3 1/2] batman-adv: Check total_size when queueing fragments Sven Eckelmann
2014-12-01 9:37 ` [B.A.T.M.A.N.] [PATCHv3 2/2] batman-adv: Use only queued fragments when merging Sven Eckelmann
@ 2014-12-01 11:38 ` Martin Hundebøll
2015-01-11 10:27 ` Marek Lindner
1 sibling, 1 reply; 6+ messages in thread
From: Martin Hundebøll @ 2014-12-01 11:38 UTC (permalink / raw)
To: The list for a Better Approach To Mobile Ad-hoc Networking; +Cc: Sven Eckelmann
Hi,
On 2014-12-01 10:37, Sven Eckelmann wrote:
> The fragmentation code was replaced in 9b3eab61754d74a93c9840c296013fe3b4a1b606
> ("batman-adv: Receive fragmented packets and merge") by an implementation which
> handles the queueing+merging of fragments based on their size and the
> total_size of the non-fragmented packet. This total_size is announced by each
> fragment. The new implementation doesn't check if the the total_size
> information of the packets inside one chain is consistent.
>
> This is consistency check is recommended to allow using any of the packets in
> the queue to decide whether all fragments of a packet are received or not.
>
> Signed-off-by: Sven Eckelmann <sven@narfation.org>
> ---
> This is only compile tested
>
> v3.
> - withdrawing from inclusion in maint
> - remove wrong example from the commit message
> v2:
> - proposed for maint
> - changed commit message slightly
> ---
> fragmentation.c | 7 +++++--
> types.h | 2 ++
> 2 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/fragmentation.c b/fragmentation.c
> index 5251aa1..6e4c957 100644
> --- a/fragmentation.c
> +++ b/fragmentation.c
> @@ -161,6 +161,7 @@ static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node,
> hlist_add_head(&frag_entry_new->list, &chain->head);
> chain->size = skb->len - hdr_size;
> chain->timestamp = jiffies;
> + chain->total_size = ntohs(frag_packet->total_size);
> ret = true;
> goto out;
> }
> @@ -195,9 +196,11 @@ static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node,
>
> out:
> if (chain->size > batadv_frag_size_limit() ||
> - ntohs(frag_packet->total_size) > batadv_frag_size_limit()) {
> + chain->total_size != ntohs(frag_packet->total_size) ||
> + chain->total_size > batadv_frag_size_limit()) {
> /* Clear chain if total size of either the list or the packet
> - * exceeds the maximum size of one merged packet.
> + * exceeds the maximum size of one merged packet. Don't allow
> + * packets to have different total_size.
> */
> batadv_frag_clear_chain(&chain->head);
> chain->size = 0;
> diff --git a/types.h b/types.h
> index 462a70c..c4d7d24 100644
> --- a/types.h
> +++ b/types.h
> @@ -132,6 +132,7 @@ struct batadv_orig_ifinfo {
> * @timestamp: time (jiffie) of last received fragment
> * @seqno: sequence number of the fragments in the list
> * @size: accumulated size of packets in list
> + * @total_size: expected size of the assembled packet
> */
> struct batadv_frag_table_entry {
> struct hlist_head head;
> @@ -139,6 +140,7 @@ struct batadv_frag_table_entry {
> unsigned long timestamp;
> uint16_t seqno;
> uint16_t size;
> + uint16_t total_size;
> };
>
> /**
>
As with the first version:
Acked-by: Martin Hundebøll <martin@hundeboll.net>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2015-01-11 10:29 UTC | newest]
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2014-12-01 9:37 [B.A.T.M.A.N.] [PATCHv3 1/2] batman-adv: Check total_size when queueing fragments Sven Eckelmann
2014-12-01 9:37 ` [B.A.T.M.A.N.] [PATCHv3 2/2] batman-adv: Use only queued fragments when merging Sven Eckelmann
2014-12-01 11:40 ` Martin Hundebøll
2015-01-11 10:29 ` Marek Lindner
2014-12-01 11:38 ` [B.A.T.M.A.N.] [PATCHv3 1/2] batman-adv: Check total_size when queueing fragments Martin Hundebøll
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