Ideally, we would need to generate IP ID using a per destination IP
generator.
linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.
1) each inet_peer struct consumes 192 bytes
2) inetpeer cache uses a binary tree of inet_peer structs,
with a nominal size of ~66000 elements under load.
3) lookups in this tree are hitting a lot of cache lines, as tree depth
is about 20.
4) If server deals with many tcp flows, we have a high probability of
not finding the inet_peer, allocating a fresh one, inserting it in
the tree with same initial ip_id_count, (cf secure_ip_id())
5) We garbage collect inet_peer aggressively.
IP ID generation do not have to be 'perfect'
Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.
We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.
ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)
secure_ip_id() and secure_ipv6_id() no longer are needed.
Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If local fragmentation is allowed, then ip_select_ident() and
ip_select_ident_more() need to generate unique IDs to ensure
correct defragmentation on the peer.
For example, if IPsec (tunnel mode) has to encrypt large skbs
that have local_df bit set, then all IP fragments that belonged
to different ESP datagrams would have used the same identificator.
If one of these IP fragments would get lost or reordered, then
peer could possibly stitch together wrong IP fragments that did
not belong to the same datagram. This would lead to a packet loss
or data corruption.
Signed-off-by: Ansis Atteka <aatteka@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pptp driver has lots of byte order warnings from sparse.
This was because the on-the-wire header is in network byte order (obviously)
but the definition did not reflect that.
Also, the address structure to user space actually put the call id
in host order. Rather than break ABI compatibility, just acknowledge
the existing design.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
callid_sock array is referenced via rcu_dereference and
sparse rcu checks complains about address space mismatch.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
pptp always use init_net as the net namespace to lookup
route, this will cause route lookup failed in container.
because we already set the correct net namespace to struct
sock in pptp_create,so fix this by using sock_net(sk) to
replace &init_net.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Call consume_skb() in place of kfree_skb() were appropriate.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use for_each_set_bit_from to iterate over all the set bit in a memory
region.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Dmitry Kozlov <xeb@mail.ru>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
This moves the definitions of the ioctls, constants and structures
relating to the ppp_generic interface to userspace out from if_ppp.h
to a new file, ppp-ioctl.h. The new file has my copyright since I
designed and implemented the ppp_generic interface in the late 1990s.
None of the contents of this file comes from the original if_ppp.h
published by Carnegie Mellon University.
Of the remainder of if_ppp.h, only the PPP_MTU definition was being
used, and this replaces the uses of it with PPP_MRU (which is identical).
Therefore, this replaces the entire file with the single line
#include <linux/ppp-ioctl.h>
which clearly doesn't contain any CMU code. Thus I have removed the
CMU copyright notice with its problematic advertising clause, and in
fact since it's only one trivial line I have not added any other
copyright notice.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
alloc failures use dump_stack so emitting an additional
out-of-memory message is an unnecessary duplication.
Remove the allocation failure messages.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initialize the PPTP "seq received" value to 0xffffffff, so we don't
ignore packets with seq zero.
Signed-off-by: Bradley Peterson <despite@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rcu_assign_pointer(ptr, NULL) can be safely replaced by
RCU_INIT_POINTER(ptr, NULL)
(old rcu_assign_pointer() macro was testing the NULL value and could
omit the smp_wmb(), but this had to be removed because of compiler
warnings)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the PPP drivers into drivers/net/ppp/ and make the
necessary Kconfig and Makefile changes.
CC: Paul Mackerras <paulus@samba.org>
CC: Frank Cusack <fcusack@fcusack.com>
CC: Michal Ostrowski <mostrows@speakeasy.net>
CC: Michal Ostrowski <mostrows@earthlink.net>
CC: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
