kernel/linux.git/include/linux/skbuff.h, branch v4.14.85

net: sk_buff rbnode reorg

2018-09-19T20:43:47+00:00

commit bffa72cf7f9df842f0016ba03586039296b4caaf upstream skb->rbnode shares space with skb->next, skb->prev and skb->tstamp Current uses (TCP receive ofo queue and netem) need to save/restore tstamp, while skb->dev is either NULL (TCP) or a constant for a given queue (netem). Since we plan using an RB tree for TCP retransmit queue to speedup SACK processing with large BDP, this patch exchanges skb->dev and skb->tstamp. This saves some overhead in both TCP and netem. v2: removes the swtstamp field from struct tcp_skb_cb Signed-off-by: Eric Dumazet Cc: Soheil Hassas Yeganeh Cc: Wei Wang Cc: Willem de Bruijn Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: add rb_to_skb() and other rb tree helpers

2018-09-19T20:43:47+00:00

Geeralize private netem_rb_to_skb() TCP rtx queue will soon be converted to rb-tree, so we will need skb_rbtree_walk() helpers. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller (cherry picked from commit 18a4c0eab2623cc95be98a1e6af1ad18e7695977) Signed-off-by: Greg Kroah-Hartman

net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends

2018-09-19T20:43:47+00:00

After working on IP defragmentation lately, I found that some large packets defeat CHECKSUM_COMPLETE optimization because of NIC adding zero paddings on the last (small) fragment. While removing the padding with pskb_trim_rcsum(), we set skb->ip_summed to CHECKSUM_NONE, forcing a full csum validation, even if all prior fragments had CHECKSUM_COMPLETE set. We can instead compute the checksum of the part we are trimming, usually smaller than the part we keep. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller (cherry picked from commit 88078d98d1bb085d72af8437707279e203524fa5) Signed-off-by: Greg Kroah-Hartman

net: modify skb_rbtree_purge to return the truesize of all purged skbs.

2018-09-19T20:43:47+00:00

Tested: see the next patch is the series. Suggested-by: Eric Dumazet Signed-off-by: Peter Oskolkov Signed-off-by: Eric Dumazet Cc: Florian Westphal Signed-off-by: David S. Miller (cherry picked from commit 385114dec8a49b5e5945e77ba7de6356106713f4) Signed-off-by: Greg Kroah-Hartman

inet: frags: get rid of ipfrag_skb_cb/FRAG_CB

2018-09-19T20:43:46+00:00

ip_defrag uses skb->cb[] to store the fragment offset, and unfortunately this integer is currently in a different cache line than skb->next, meaning that we use two cache lines per skb when finding the insertion point. By aliasing skb->ip_defrag_offset and skb->dev, we pack all the fields in a single cache line and save precious memory bandwidth. Note that after the fast path added by Changli Gao in commit d6bebca92c66 ("fragment: add fast path for in-order fragments") this change wont help the fast path, since we still need to access prev->len (2nd cache line), but will show great benefits when slow path is entered, since we perform a linear scan of a potentially long list. Also, note that this potential long list is an attack vector, we might consider also using an rb-tree there eventually. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller (cherry picked from commit bf66337140c64c27fa37222b7abca7e49d63fb57) Signed-off-by: Greg Kroah-Hartman

tcp: free batches of packets in tcp_prune_ofo_queue()

2018-07-28T05:55:43+00:00

[ Upstream commit 72cd43ba64fc172a443410ce01645895850844c8 ] Juha-Matti Tilli reported that malicious peers could inject tiny packets in out_of_order_queue, forcing very expensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() for every incoming packet. out_of_order_queue rb-tree can contain thousands of nodes, iterating over all of them is not nice. Before linux-4.9, we would have pruned all packets in ofo_queue in one go, every XXXX packets. XXXX depends on sk_rcvbuf and skbs truesize, but is about 7000 packets with tcp_rmem[2] default of 6 MB. Since we plan to increase tcp_rmem[2] in the future to cope with modern BDP, can not revert to the old behavior, without great pain. Strategy taken in this patch is to purge ~12.5 % of the queue capacity. Fixes: 36a6503fedda ("tcp: refine tcp_prune_ofo_queue() to not drop all packets") Signed-off-by: Eric Dumazet Reported-by: Juha-Matti Tilli Acked-by: Yuchung Cheng Acked-by: Soheil Hassas Yeganeh Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: Don't copy pfmemalloc flag in __copy_skb_header()

2018-07-25T09:25:09+00:00

[ Upstream commit 8b7008620b8452728cadead460a36f64ed78c460 ] The pfmemalloc flag indicates that the skb was allocated from the PFMEMALLOC reserves, and the flag is currently copied on skb copy and clone. However, an skb copied from an skb flagged with pfmemalloc wasn't necessarily allocated from PFMEMALLOC reserves, and on the other hand an skb allocated that way might be copied from an skb that wasn't. So we should not copy the flag on skb copy, and rather decide whether to allow an skb to be associated with sockets unrelated to page reclaim depending only on how it was allocated. Move the pfmemalloc flag before headers_start[0] using an existing 1-bit hole, so that __copy_skb_header() doesn't copy it. When cloning, we'll now take care of this flag explicitly, contravening to the warning comment of __skb_clone(). While at it, restore the newline usage introduced by commit b19372273164 ("net: reorganize sk_buff for faster __copy_skb_header()") to visually separate bytes used in bitfields after headers_start[0], that was gone after commit a9e419dc7be6 ("netfilter: merge ctinfo into nfct pointer storage area"), and describe the pfmemalloc flag in the kernel-doc structure comment. This doesn't change the size of sk_buff or cacheline boundaries, but consolidates the 15 bits hole before tc_index into a 2 bytes hole before csum, that could now be filled more easily. Reported-by: Patrick Talbert Fixes: c93bdd0e03e8 ("netvm: allow skb allocation to use PFMEMALLOC reserves") Signed-off-by: Stefano Brivio Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

kmemcheck: remove annotations

2018-02-22T14:42:23+00:00

commit 4950276672fce5c241857540f8561c440663673d upstream. Patch series "kmemcheck: kill kmemcheck", v2. As discussed at LSF/MM, kill kmemcheck. KASan is a replacement that is able to work without the limitation of kmemcheck (single CPU, slow). KASan is already upstream. We are also not aware of any users of kmemcheck (or users who don't consider KASan as a suitable replacement). The only objection was that since KASAN wasn't supported by all GCC versions provided by distros at that time we should hold off for 2 years, and try again. Now that 2 years have passed, and all distros provide gcc that supports KASAN, kill kmemcheck again for the very same reasons. This patch (of 4): Remove kmemcheck annotations, and calls to kmemcheck from the kernel. [alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs] Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.com Signed-off-by: Sasha Levin Cc: Alexander Potapenko Cc: Eric W. Biederman Cc: Michal Hocko Cc: Pekka Enberg Cc: Steven Rostedt Cc: Tim Hansen Cc: Vegard Nossum Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

net: accept UFO datagrams from tuntap and packet

2017-12-17T14:07:58+00:00

[ Upstream commit 0c19f846d582af919db66a5914a0189f9f92c936 ] Tuntap and similar devices can inject GSO packets. Accept type VIRTIO_NET_HDR_GSO_UDP, even though not generating UFO natively. Processes are expected to use feature negotiation such as TUNSETOFFLOAD to detect supported offload types and refrain from injecting other packets. This process breaks down with live migration: guest kernels do not renegotiate flags, so destination hosts need to expose all features that the source host does. Partially revert the UFO removal from 182e0b6b5846~1..d9d30adf5677. This patch introduces nearly(*) no new code to simplify verification. It brings back verbatim tuntap UFO negotiation, VIRTIO_NET_HDR_GSO_UDP insertion and software UFO segmentation. It does not reinstate protocol stack support, hardware offload (NETIF_F_UFO), SKB_GSO_UDP tunneling in SKB_GSO_SOFTWARE or reception of VIRTIO_NET_HDR_GSO_UDP packets in tuntap. To support SKB_GSO_UDP reappearing in the stack, also reinstate logic in act_csum and openvswitch. Achieve equivalence with v4.13 HEAD by squashing in commit 939912216fa8 ("net: skb_needs_check() removes CHECKSUM_UNNECESSARY check for tx.") and reverting commit 8d63bee643f1 ("net: avoid skb_warn_bad_offload false positives on UFO"). (*) To avoid having to bring back skb_shinfo(skb)->ip6_frag_id, ipv6_proxy_select_ident is changed to return a __be32 and this is assigned directly to the frag_hdr. Also, SKB_GSO_UDP is inserted at the end of the enum to minimize code churn. Tested Booted a v4.13 guest kernel with QEMU. On a host kernel before this patch `ethtool -k eth0` shows UFO disabled. After the patch, it is enabled, same as on a v4.13 host kernel. A UFO packet sent from the guest appears on the tap device: host: nc -l -p -u 8000 & tcpdump -n -i tap0 guest: dd if=/dev/zero of=payload.txt bs=1 count=2000 nc -u 192.16.1.1 8000 < payload.txt Direct tap to tap transmission of VIRTIO_NET_HDR_GSO_UDP succeeds, packets arriving fragmented: ./with_tap_pair.sh ./tap_send_ufo tap0 tap1 (from https://github.com/wdebruij/kerneltools/tree/master/tests) Changes v1 -> v2 - simplified set_offload change (review comment) - documented test procedure Link: http://lkml.kernel.org/r/ Fixes: fb652fdfe837 ("macvlan/macvtap: Remove NETIF_F_UFO advertisement.") Reported-by: Michal Kubecek Signed-off-by: Willem de Bruijn Acked-by: Jason Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

netfilter/ipvs: clear ipvs_property flag when SKB net namespace changed

2017-11-04T13:37:42+00:00

When run ipvs in two different network namespace at the same host, and one ipvs transport network traffic to the other network namespace ipvs. 'ipvs_property' flag will make the second ipvs take no effect. So we should clear 'ipvs_property' when SKB network namespace changed. Fixes: 621e84d6f373 ("dev: introduce skb_scrub_packet()") Signed-off-by: Ye Yin Signed-off-by: Wei Zhou Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman Signed-off-by: David S. Miller