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2014-12-24batman-adv: Unify fragment size calculationSven Eckelmann1-1/+1
The fragmentation code was replaced in 610bfc6bc99bc83680d190ebc69359a05fc7f605 ("batman-adv: Receive fragmented packets and merge") by an implementation which can handle up to 16 fragments of a packet. The packet is prepared for the split in fragments by the function batadv_frag_send_packet and the actual split is done by batadv_frag_create. Both functions calculate the size of a fragment themself. But their calculation differs because batadv_frag_send_packet also subtracts ETH_HLEN. Therefore, the check in batadv_frag_send_packet "can a full fragment can be created?" may return true even when batadv_frag_create cannot create a full fragment. The function batadv_frag_create doesn't check the size of the skb before splitting it and therefore might try to create a larger fragment than the remaining buffer. This creates an integer underflow and an invalid len is given to skb_split. Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-24batman-adv: Calculate extra tail size based on queued fragmentsSven Eckelmann1-1/+1
The fragmentation code was replaced in 610bfc6bc99bc83680d190ebc69359a05fc7f605 ("batman-adv: Receive fragmented packets and merge"). The new code provided a mostly unused parameter skb for the merging function. It is used inside the function to calculate the additionally needed skb tailroom. But instead of increasing its own tailroom, it is only increasing the tailroom of the first queued skb. This is not correct in some situations because the first queued entry can be a different one than the parameter. An observed problem was: 1. packet with size 104, total_size 1464, fragno 1 was received - packet is queued 2. packet with size 1400, total_size 1464, fragno 0 was received - packet is queued at the end of the list 3. enough data was received and can be given to the merge function (1464 == (1400 - 20) + (104 - 20)) - merge functions gets 1400 byte large packet as skb argument 4. merge function gets first entry in queue (104 byte) - stored as skb_out 5. merge function calculates the required extra tail as total_size - skb->len - pskb_expand_head tail of skb_out with 64 bytes 6. merge function tries to squeeze the extra 1380 bytes from the second queued skb (1400 byte aka skb parameter) in the 64 extra tail bytes of skb_out Instead calculate the extra required tail bytes for skb_out also using skb_out instead of using the parameter skb. The skb parameter is only used to get the total_size from the last received packet. This is also the total_size used to decide that all fragments were received. Reported-by: Philipp Psurek <philipp.psurek@gmail.com> Signed-off-by: Sven Eckelmann <sven@narfation.org> Acked-by: Martin Hundebøll <martin@hundeboll.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-17batman-adv: Fix parameter order of hlist_add_behindSven Eckelmann1-1/+1
1d023284c31a4e40a94d5bbcb7dbb7a35ee0bcbc ("list: fix order of arguments for hlist_add_after(_rcu)") was incorrectly rebased on top of d9124268d84a836f14a6ead54ff9d8eee4c43be5 ("batman-adv: Fix out-of-order fragmentation support"). The parameter order change of the rebased patch was not re-applied as expected. This causes a memory leak and can cause crashes when out-of-order packets are received. hlist_add_behind will try to access the uninitalized list pointers of frag_entry_new to find the previous/next entry and may modify/read random memory locations. Signed-off-by: Sven Eckelmann <sven@narfation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-07list: fix order of arguments for hlist_add_after(_rcu)Ken Helias1-1/+1
All other add functions for lists have the new item as first argument and the position where it is added as second argument. This was changed for no good reason in this function and makes using it unnecessary confusing. The name was changed to hlist_add_behind() to cause unconverted code to generate a compile error instead of using the wrong parameter order. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Ken Helias <kenhelias@firemail.de> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> [intel driver bits] Cc: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-05batman-adv: Fix out-of-order fragmentation supportSven Eckelmann1-3/+7
batadv_frag_insert_packet was unable to handle out-of-order packets because it dropped them directly. This is caused by the way the fragmentation lists is checked for the correct place to insert a fragmentation entry. The fragmentation code keeps the fragments in lists. The fragmentation entries are kept in descending order of sequence number. The list is traversed and each entry is compared with the new fragment. If the current entry has a smaller sequence number than the new fragment then the new one has to be inserted before the current entry. This ensures that the list is still in descending order. An out-of-order packet with a smaller sequence number than all entries in the list still has to be added to the end of the list. The used hlist has no information about the last entry in the list inside hlist_head and thus the last entry has to be calculated differently. Currently the code assumes that the iterator variable of hlist_for_each_entry can be used for this purpose after the hlist_for_each_entry finished. This is obviously wrong because the iterator variable is always NULL when the list was completely traversed. Instead the information about the last entry has to be stored in a different variable. This problem was introduced in 610bfc6bc99bc83680d190ebc69359a05fc7f605 ("batman-adv: Receive fragmented packets and merge"). Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2014-05-15batman-adv: fix reference counting imbalance while sending fragmentAntonio Quartulli1-3/+8
In the new fragmentation code the batadv_frag_send_packet() function obtains a reference to the primary_if, but it does not release it upon return. This reference imbalance prevents the primary_if (and then the related netdevice) to be properly released on shut down. Fix this by releasing the primary_if in batadv_frag_send_packet(). Introduced by ee75ed88879af88558818a5c6609d85f60ff0df4 ("batman-adv: Fragment and send skbs larger than mtu") Cc: Martin Hundebøll <martin@hundeboll.net> Signed-off-by: Antonio Quartulli <antonio@open-mesh.com> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Acked-by: Martin Hundebøll <martin@hundeboll.net>
2014-03-22batman-adv: prefer ether_addr_copy to memcpyAntonio Quartulli1-2/+2
On some architectures ether_addr_copy() is slightly faster than memcpy() therefore use the former when possible. Signed-off-by: Antonio Quartulli <antonio@meshcoding.com> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
2014-01-12batman-adv: update copyright years for 2014Simon Wunderlich1-1/+1
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2014-01-08batman-adv: remove FSF address from GPL disclaimerAntonio Quartulli1-3/+1
As suggested by checkpatch, remove all the references to the FSF address since the kernel already has one reference in its documentation. In this way it is easier to update it in case of future changes. Signed-off-by: Antonio Quartulli <antonio@meshcoding.com> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
2013-12-28batman-adv: fix header alignment by unrolling batadv_headerSimon Wunderlich1-4/+4
The size of the batadv_header of 3 is problematic on some architectures which automatically pad all structures to a 32 bit boundary. To not lose performance by packing this struct, better embed it into the various host structures. Reported-by: Russell King <linux@arm.linux.org.uk> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-12batman-adv: Fragment and send skbs larger than mtuMartin Hundebøll1-0/+121
Non-broadcast packets larger than MTU are fragmented and sent with an encapsulating header. Up to 16 fragments are supported, which are sent in reverse order on the wire to allow minimal memory copying when creating fragments. Signed-off-by: Martin Hundebøll <martin@hundeboll.net> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
2013-10-12batman-adv: Receive fragmented packets and mergeMartin Hundebøll1-0/+370
Fragments arriving at their destination are buffered for later merge. Merged packets are passed to the main receive function as had they never been fragmented. Fragments are forwarded without merging if the MTU of the outgoing interface is smaller than the size of the merged packet. Signed-off-by: Martin Hundebøll <martin@hundeboll.net> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>