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2016-05-21net: suppress warnings on dev_alloc_skbNeil Horman1-2/+2
Noticed an allocation failure in a network driver the other day on a 32 bit system: DMA-API: debugging out of memory - disabling bnx2fc: adapter_lookup: hba NULL lldpad: page allocation failure. order:0, mode:0x4120 Pid: 4556, comm: lldpad Not tainted 2.6.32-639.el6.i686.debug #1 Call Trace: [<c08a4086>] ? printk+0x19/0x23 [<c05166a4>] ? __alloc_pages_nodemask+0x664/0x830 [<c0649d02>] ? free_object+0x82/0xa0 [<fb4e2c9b>] ? ixgbe_alloc_rx_buffers+0x10b/0x1d0 [ixgbe] [<fb4e2fff>] ? ixgbe_configure_rx_ring+0x29f/0x420 [ixgbe] [<fb4e228c>] ? ixgbe_configure_tx_ring+0x15c/0x220 [ixgbe] [<fb4e3709>] ? ixgbe_configure+0x589/0xc00 [ixgbe] [<fb4e7be7>] ? ixgbe_open+0xa7/0x5c0 [ixgbe] [<fb503ce6>] ? ixgbe_init_interrupt_scheme+0x5b6/0x970 [ixgbe] [<fb4e8e54>] ? ixgbe_setup_tc+0x1a4/0x260 [ixgbe] [<fb505a9f>] ? ixgbe_dcbnl_set_state+0x7f/0x90 [ixgbe] [<c088d80d>] ? dcb_doit+0x10ed/0x16d0 ... Thought that perhaps the big splat in the logs wasn't really necessecary, as all call sites for dev_alloc_skb: a) check the return code for the function and b) either print their own error message or have a recovery path that makes the warning moot. Fix it by modifying dev_alloc_pages to pass __GFP_NOWARN as a gfp flag to suppress the warning applies to the net tree Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: "David S. Miller" <davem@davemloft.net> CC: Eric Dumazet <eric.dumazet@gmail.com> CC: Alexander Duyck <alexander.duyck@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-21net: define gso types for IPx over IPv4 and IPv6Tom Herbert1-2/+2
This patch defines two new GSO definitions SKB_GSO_IPXIP4 and SKB_GSO_IPXIP6 along with corresponding NETIF_F_GSO_IPXIP4 and NETIF_F_GSO_IPXIP6. These are used to described IP in IP tunnel and what the outer protocol is. The inner protocol can be deduced from other GSO types (e.g. SKB_GSO_TCPV4 and SKB_GSO_TCPV6). The GSO types of SKB_GSO_IPIP and SKB_GSO_SIT are removed (these are both instances of SKB_GSO_IPXIP4). SKB_GSO_IPXIP6 will be used when support for GSO with IP encapsulation over IPv6 is added. Signed-off-by: Tom Herbert <tom@herbertland.com> Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-03net: relax expensive skb_unclone() in iptunnel_handle_offloads()Eric Dumazet1-0/+10
Locally generated TCP GSO packets having to go through a GRE/SIT/IPIP tunnel have to go through an expensive skb_unclone() Reallocating skb->head is a lot of work. Test should really check if a 'real clone' of the packet was done. TCP does not care if the original gso_type is changed while the packet travels in the stack. This adds skb_header_unclone() which is a variant of skb_clone() using skb_header_cloned() check instead of skb_cloned(). This variant can probably be used from other points. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-28tcp: remove SKBTX_ACK_TSTAMP since it is redundantSoheil Hassas Yeganeh1-5/+1
The SKBTX_ACK_TSTAMP flag is set in skb_shinfo->tx_flags when the timestamp of the TCP acknowledgement should be reported on error queue. Since accessing skb_shinfo is likely to incur a cache-line miss at the time of receiving the ack, the txstamp_ack bit was added in tcp_skb_cb, which is set iff the SKBTX_ACK_TSTAMP flag is set for an skb. This makes SKBTX_ACK_TSTAMP flag redundant. Remove the SKBTX_ACK_TSTAMP and instead use the txstamp_ack bit everywhere. Note that this frees one bit in shinfo->tx_flags. Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Suggested-by: Willem de Bruijn <willemb@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-25skbuff: Add pskb_extract() helper functionSowmini Varadhan1-0/+2
A pattern of skb usage seen in modules such as RDS-TCP is to extract `to_copy' bytes from the received TCP segment, starting at some offset `off' into a new skb `clone'. This is done in the ->data_ready callback, where the clone skb is queued up for rx on the PF_RDS socket, while the parent TCP segment is returned unchanged back to the TCP engine. The existing code uses the sequence clone = skb_clone(..); pskb_pull(clone, off, ..); pskb_trim(clone, to_copy, ..); with the intention of discarding the first `off' bytes. However, skb_clone() + pskb_pull() implies pksb_expand_head(), which ends up doing a redundant memcpy of bytes that will then get discarded in __pskb_pull_tail(). To avoid this inefficiency, this commit adds pskb_extract() that creates the clone, and memcpy's only the relevant header/frag/frag_list to the start of `clone'. pskb_trim() is then invoked to trim clone down to the requested to_copy bytes. Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-14GSO: Support partial segmentation offloadAlexander Duyck1-2/+7
This patch adds support for something I am referring to as GSO partial. The basic idea is that we can support a broader range of devices for segmentation if we use fixed outer headers and have the hardware only really deal with segmenting the inner header. The idea behind the naming is due to the fact that everything before csum_start will be fixed headers, and everything after will be the region that is handled by hardware. With the current implementation it allows us to add support for the following GSO types with an inner TSO_MANGLEID or TSO6 offload: NETIF_F_GSO_GRE NETIF_F_GSO_GRE_CSUM NETIF_F_GSO_IPIP NETIF_F_GSO_SIT NETIF_F_UDP_TUNNEL NETIF_F_UDP_TUNNEL_CSUM In the case of hardware that already supports tunneling we may be able to extend this further to support TSO_TCPV4 without TSO_MANGLEID if the hardware can support updating inner IPv4 headers. Signed-off-by: Alexander Duyck <aduyck@mirantis.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-14GSO: Add GSO type for fixed IPv4 IDAlexander Duyck1-9/+11
This patch adds support for TSO using IPv4 headers with a fixed IP ID field. This is meant to allow us to do a lossless GRO in the case of TCP flows that use a fixed IP ID such as those that convert IPv6 header to IPv4 headers. In addition I am adding a feature that for now I am referring to TSO with IP ID mangling. Basically when this flag is enabled the device has the option to either output the flow with incrementing IP IDs or with a fixed IP ID regardless of what the original IP ID ordering was. This is useful in cases where the DF bit is set and we do not care if the original IP ID value is maintained. Signed-off-by: Alexander Duyck <aduyck@mirantis.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-05udp: enable MSG_PEEK at non-zero offsetsamanthakumar1-1/+6
Enable peeking at UDP datagrams at the offset specified with socket option SOL_SOCKET/SO_PEEK_OFF. Peek at any datagram in the queue, up to the end of the given datagram. Implement the SO_PEEK_OFF semantics introduced in commit ef64a54f6e55 ("sock: Introduce the SO_PEEK_OFF sock option"). Increase the offset on peek, decrease it on regular reads. When peeking, always checksum the packet immediately, to avoid recomputation on subsequent peeks and final read. The socket lock is not held for the duration of udp_recvmsg, so peek and read operations can run concurrently. Only the last store to sk_peek_off is preserved. Signed-off-by: Sam Kumar <samanthakumar@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-0/+24
Several cases of overlapping changes, as well as one instance (vxlan) of a bug fix in 'net' overlapping with code movement in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-03mld, igmp: Fix reserved tailroom calculationBenjamin Poirier1-0/+24
The current reserved_tailroom calculation fails to take hlen and tlen into account. skb: [__hlen__|__data____________|__tlen___|__extra__] ^ ^ head skb_end_offset In this representation, hlen + data + tlen is the size passed to alloc_skb. "extra" is the extra space made available in __alloc_skb because of rounding up by kmalloc. We can reorder the representation like so: [__hlen__|__data____________|__extra__|__tlen___] ^ ^ head skb_end_offset The maximum space available for ip headers and payload without fragmentation is min(mtu, data + extra). Therefore, reserved_tailroom = data + extra + tlen - min(mtu, data + extra) = skb_end_offset - hlen - min(mtu, skb_end_offset - hlen - tlen) = skb_tailroom - min(mtu, skb_tailroom - tlen) ; after skb_reserve(hlen) Compare the second line to the current expression: reserved_tailroom = skb_end_offset - min(mtu, skb_end_offset) and we can see that hlen and tlen are not taken into account. The min() in the third line can be expanded into: if mtu < skb_tailroom - tlen: reserved_tailroom = skb_tailroom - mtu else: reserved_tailroom = tlen Depending on hlen, tlen, mtu and the number of multicast address records, the current code may output skbs that have less tailroom than dev->needed_tailroom or it may output more skbs than needed because not all space available is used. Fixes: 4c672e4b ("ipv6: mld: fix add_grhead skb_over_panic for devs with large MTUs") Signed-off-by: Benjamin Poirier <bpoirier@suse.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-02net: remove skb_sender_cpu_clear()WANG Cong1-4/+0
After commit 52bd2d62ce67 ("net: better skb->sender_cpu and skb->napi_id cohabitation") skb_sender_cpu_clear() becomes empty and can be removed. Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-0/+1
Conflicts: drivers/net/phy/bcm7xxx.c drivers/net/phy/marvell.c drivers/net/vxlan.c All three conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-22bpf: try harder on clones when writing into skbDaniel Borkmann1-0/+7
When we're dealing with clones and the area is not writeable, try harder and get a copy via pskb_expand_head(). Replace also other occurences in tc actions with the new skb_try_make_writable(). Reported-by: Ashhad Sheikh <ashhadsheikh394@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-18net: Optimize local checksum offloadAlexander Duyck1-9/+8
This patch takes advantage of several assumptions we can make about the headers of the frame in order to reduce overall processing overhead for computing the outer header checksum. First we can assume the entire header is in the region pointed to by skb->head as this is what csum_start is based on. Second, as a result of our first assumption, we can just call csum_partial instead of making a call to skb_checksum which would end up having to configure things so that we could walk through the frags list. Signed-off-by: Alexander Duyck <aduyck@mirantis.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-12Documentation/networking: add checksum-offloads.txt to explain LCOEdward Cree1-0/+2
Signed-off-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-12net: local checksum offload for encapsulationEdward Cree1-0/+24
The arithmetic properties of the ones-complement checksum mean that a correctly checksummed inner packet, including its checksum, has a ones complement sum depending only on whatever value was used to initialise the checksum field before checksumming (in the case of TCP and UDP, this is the ones complement sum of the pseudo header, complemented). Consequently, if we are going to offload the inner checksum with CHECKSUM_PARTIAL, we can compute the outer checksum based only on the packed data not covered by the inner checksum, and the initial value of the inner checksum field. Signed-off-by: Edward Cree <ecree@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-11net: bulk free SKBs that were delay free'ed due to IRQ contextJesper Dangaard Brouer1-0/+1
The network stack defers SKBs free, in-case free happens in IRQ or when IRQs are disabled. This happens in __dev_kfree_skb_irq() that writes SKBs that were free'ed during IRQ to the softirq completion queue (softnet_data.completion_queue). These SKBs are naturally delayed, and cleaned up during NET_TX_SOFTIRQ in function net_tx_action(). Take advantage of this a use the skb defer and flush API, as we are already in softirq context. For modern drivers this rarely happens. Although most drivers do call dev_kfree_skb_any(), which detects the situation and calls __dev_kfree_skb_irq() when needed. This due to netpoll can call from IRQ context. Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-11net: bulk free infrastructure for NAPI context, use napi_consume_skbJesper Dangaard Brouer1-0/+3
Discovered that network stack were hitting the kmem_cache/SLUB slowpath when freeing SKBs. Doing bulk free with kmem_cache_free_bulk can speedup this slowpath. NAPI context is a bit special, lets take advantage of that for bulk free'ing SKBs. In NAPI context we are running in softirq, which gives us certain protection. A softirq can run on several CPUs at once. BUT the important part is a softirq will never preempt another softirq running on the same CPU. This gives us the opportunity to access per-cpu variables in softirq context. Extend napi_alloc_cache (before only contained page_frag_cache) to be a struct with a small array based stack for holding SKBs. Introduce a SKB defer and flush API for accessing this. Introduce napi_consume_skb() as replacement for e.g. dev_consume_skb_any() when running in NAPI context. A small trick to handle/detect if we are called from netpoll is to see if budget is 0. In that case, we need to invoke dev_consume_skb_irq(). Joint work with Alexander Duyck. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-11net: Store checksum result for offloaded GSO checksumsAlexander Duyck1-0/+15
This patch makes it so that we can offload the checksums for a packet up to a certain point and then begin computing the checksums via software. Setting this up is fairly straight forward as all we need to do is reset the values stored in csum and csum_start for the GSO context block. One complication for this is remote checksum offload. In order to allow the inner checksums to be offloaded while computing the outer checksum manually we needed to have some way of indicating that the offload wasn't real. In order to do that I replaced CHECKSUM_PARTIAL with CHECKSUM_UNNECESSARY in the case of us computing checksums for the outer header while skipping computing checksums for the inner headers. We clean up the ip_summed flag and set it to either CHECKSUM_PARTIAL or CHECKSUM_NONE once we hand the packet off to the next lower level. Signed-off-by: Alexander Duyck <aduyck@mirantis.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-11net: Move GSO csum into SKB_GSO_CBAlexander Duyck1-7/+7
This patch moves the checksum maintained by GSO out of skb->csum and into the GSO context block in order to allow for us to work on outer checksums while maintaining the inner checksum offsets in the case of the inner checksum being offloaded, while the outer checksums will be computed. While updating the code I also did a minor cleanu-up on gso_make_checksum. The change is mostly to make it so that we store the values and compute the checksum instead of computing the checksum and then storing the values we needed to update. Signed-off-by: Alexander Duyck <aduyck@mirantis.com> Acked-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-09net:Add sysctl_max_skb_fragsHans Westgaard Ry1-0/+1
Devices may have limits on the number of fragments in an skb they support. Current codebase uses a constant as maximum for number of fragments one skb can hold and use. When enabling scatter/gather and running traffic with many small messages the codebase uses the maximum number of fragments and may thereby violate the max for certain devices. The patch introduces a global variable as max number of fragments. Signed-off-by: Hans Westgaard Ry <hans.westgaard.ry@oracle.com> Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-15net: preserve IP control block during GSO segmentationKonstantin Khlebnikov1-1/+2
Skb_gso_segment() uses skb control block during segmentation. This patch adds 32-bytes room for previous control block which will be copied into all resulting segments. This patch fixes kernel crash during fragmenting forwarded packets. Fragmentation requires valid IP CB in skb for clearing ip options. Also patch removes custom save/restore in ovs code, now it's redundant. Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Link: http://lkml.kernel.org/r/CALYGNiP-0MZ-FExV2HutTvE9U-QQtkKSoE--KN=JQE5STYsjAA@mail.gmail.com Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-11bpf: add skb_postpush_rcsum and fix dev_forward_skb occasionsDaniel Borkmann1-0/+17
Add a small helper skb_postpush_rcsum() and fix up redirect locations that need CHECKSUM_COMPLETE fixups on ingress. dev_forward_skb() expects a proper csum that covers also Ethernet header, f.e. since 2c26d34bbcc0 ("net/core: Handle csum for CHECKSUM_COMPLETE VXLAN forwarding"), we also do skb_postpull_rcsum() after pulling Ethernet header off via eth_type_trans(). When using eBPF in a netns setup f.e. with vxlan in collect metadata mode, I can trigger the following csum issue with an IPv6 setup: [ 505.144065] dummy1: hw csum failure [...] [ 505.144108] Call Trace: [ 505.144112] <IRQ> [<ffffffff81372f08>] dump_stack+0x44/0x5c [ 505.144134] [<ffffffff81607cea>] netdev_rx_csum_fault+0x3a/0x40 [ 505.144142] [<ffffffff815fee3f>] __skb_checksum_complete+0xcf/0xe0 [ 505.144149] [<ffffffff816f0902>] nf_ip6_checksum+0xb2/0x120 [ 505.144161] [<ffffffffa08c0e0e>] icmpv6_error+0x17e/0x328 [nf_conntrack_ipv6] [ 505.144170] [<ffffffffa0898eca>] ? ip6t_do_table+0x2fa/0x645 [ip6_tables] [ 505.144177] [<ffffffffa08c0725>] ? ipv6_get_l4proto+0x65/0xd0 [nf_conntrack_ipv6] [ 505.144189] [<ffffffffa06c9a12>] nf_conntrack_in+0xc2/0x5a0 [nf_conntrack] [ 505.144196] [<ffffffffa08c039c>] ipv6_conntrack_in+0x1c/0x20 [nf_conntrack_ipv6] [ 505.144204] [<ffffffff8164385d>] nf_iterate+0x5d/0x70 [ 505.144210] [<ffffffff816438d6>] nf_hook_slow+0x66/0xc0 [ 505.144218] [<ffffffff816bd302>] ipv6_rcv+0x3f2/0x4f0 [ 505.144225] [<ffffffff816bca40>] ? ip6_make_skb+0x1b0/0x1b0 [ 505.144232] [<ffffffff8160b77b>] __netif_receive_skb_core+0x36b/0x9a0 [ 505.144239] [<ffffffff8160bdc8>] ? __netif_receive_skb+0x18/0x60 [ 505.144245] [<ffffffff8160bdc8>] __netif_receive_skb+0x18/0x60 [ 505.144252] [<ffffffff8160ccff>] process_backlog+0x9f/0x140 [ 505.144259] [<ffffffff8160c4a5>] net_rx_action+0x145/0x320 [...] What happens is that on ingress, we push Ethernet header back in, either from cls_bpf or right before skb_do_redirect(), but without updating csum. The "hw csum failure" can be fixed by using the new skb_postpush_rcsum() helper for the dev_forward_skb() case to correct the csum diff again. Thanks to Hannes Frederic Sowa for the csum_partial() idea! Fixes: 3896d655f4d4 ("bpf: introduce bpf_clone_redirect() helper") Fixes: 27b29f63058d ("bpf: add bpf_redirect() helper") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-16net: Elaborate on checksum offload interface descriptionTom Herbert1-29/+109
Add specifics and details the description of the interface between the stack and drivers for doing checksum offload. This description is meant to be as specific and complete as possible. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-16net: Add skb_inner_transport_offset functionTom Herbert1-0/+5
Same thing as skb_transport_offset but returns the offset of the inner transport header (when skb->encpasulation is set). Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-15net: Fix typo in skb_fclone_busyMasanari Iida1-1/+1
This patch fix a typo found within comment of skb_fclone_busy. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-07core: enable more fine-grained datagram reception controlRainer Weikusat1-0/+6
The __skb_recv_datagram routine in core/ datagram.c provides a general skb reception factility supposed to be utilized by protocol modules providing datagram sockets. It encompasses both the actual recvmsg code and a surrounding 'sleep until data is available' loop. This is inconvenient if a protocol module has to use additional locking in order to maintain some per-socket state the generic datagram socket code is unaware of (as the af_unix code does). The patch below moves the recvmsg proper code into a new __skb_try_recv_datagram routine which doesn't sleep and renames wait_for_more_packets to __skb_wait_for_more_packets, both routines being exported interfaces. The original __skb_recv_datagram routine is reimplemented on top of these two functions such that its user-visible behaviour remains unchanged. Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-19net: better skb->sender_cpu and skb->napi_id cohabitationEric Dumazet1-3/+0
skb->sender_cpu and skb->napi_id share a common storage, and we had various bugs about this. We had to call skb_sender_cpu_clear() in some places to not leave a prior skb->napi_id and fool netdev_pick_tx() As suggested by Alexei, we could split the space so that these errors can not happen. 0 value being reserved as the common (not initialized) value, let's reserve [1 .. NR_CPUS] range for valid sender_cpu, and [NR_CPUS+1 .. ~0U] for valid napi_id. This will allow proper busy polling support over tunnels. Signed-off-by: Eric Dumazet <edumazet@google.com> Suggested-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-07mm, page_alloc: distinguish between being unable to sleep, unwilling to ↵Mel Gorman1-3/+3
sleep and avoiding waking kswapd __GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-21tcp: skb_mstamp_after helperYuchung Cheng1-0/+9
a helper to prepare the first main RACK patch. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-30skbuff: Fix skb checksum partial check.Pravin B Shelar1-1/+1
Earlier patch 6ae459bda tried to detect void ckecksum partial skb by comparing pull length to checksum offset. But it does not work for all cases since checksum-offset depends on updates to skb->data. Following patch fixes it by validating checksum start offset after skb-data pointer is updated. Negative value of checksum offset start means there is no need to checksum. Fixes: 6ae459bda ("skbuff: Fix skb checksum flag on skb pull") Reported-by: Andrew Vagin <avagin@odin.com> Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-25skbuff: Fix skb checksum flag on skb pullPravin B Shelar1-0/+3
VXLAN device can receive skb with checksum partial. But the checksum offset could be in outer header which is pulled on receive. This results in negative checksum offset for the skb. Such skb can cause the assert failure in skb_checksum_help(). Following patch fixes the bug by setting checksum-none while pulling outer header. Following is the kernel panic msg from old kernel hitting the bug. ------------[ cut here ]------------ kernel BUG at net/core/dev.c:1906! RIP: 0010:[<ffffffff81518034>] skb_checksum_help+0x144/0x150 Call Trace: <IRQ> [<ffffffffa0164c28>] queue_userspace_packet+0x408/0x470 [openvswitch] [<ffffffffa016614d>] ovs_dp_upcall+0x5d/0x60 [openvswitch] [<ffffffffa0166236>] ovs_dp_process_packet_with_key+0xe6/0x100 [openvswitch] [<ffffffffa016629b>] ovs_dp_process_received_packet+0x4b/0x80 [openvswitch] [<ffffffffa016c51a>] ovs_vport_receive+0x2a/0x30 [openvswitch] [<ffffffffa0171383>] vxlan_rcv+0x53/0x60 [openvswitch] [<ffffffffa01734cb>] vxlan_udp_encap_recv+0x8b/0xf0 [openvswitch] [<ffffffff8157addc>] udp_queue_rcv_skb+0x2dc/0x3b0 [<ffffffff8157b56f>] __udp4_lib_rcv+0x1cf/0x6c0 [<ffffffff8157ba7a>] udp_rcv+0x1a/0x20 [<ffffffff8154fdbd>] ip_local_deliver_finish+0xdd/0x280 [<ffffffff81550128>] ip_local_deliver+0x88/0x90 [<ffffffff8154fa7d>] ip_rcv_finish+0x10d/0x370 [<ffffffff81550365>] ip_rcv+0x235/0x300 [<ffffffff8151ba1d>] __netif_receive_skb+0x55d/0x620 [<ffffffff8151c360>] netif_receive_skb+0x80/0x90 [<ffffffff81459935>] virtnet_poll+0x555/0x6f0 [<ffffffff8151cd04>] net_rx_action+0x134/0x290 [<ffffffff810683d8>] __do_softirq+0xa8/0x210 [<ffffffff8162fe6c>] call_softirq+0x1c/0x30 [<ffffffff810161a5>] do_softirq+0x65/0xa0 [<ffffffff810687be>] irq_exit+0x8e/0xb0 [<ffffffff81630733>] do_IRQ+0x63/0xe0 [<ffffffff81625f2e>] common_interrupt+0x6e/0x6e Reported-by: Anupam Chanda <achanda@vmware.com> Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Acked-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-14netfilter: bridge: fix routing of bridge frames with call-iptables=1Florian Westphal1-3/+3
We can't re-use the physoutdev storage area. 1. When using NFQUEUE in PREROUTING, we attempt to bump a bogus refcnt since nf_bridge->physoutdev is garbage (ipv4/ipv6 address) 2. for same reason, we crash in physdev match in FORWARD or later if skb is routed instead of bridged. This increases nf_bridge_info to 40 bytes, but we have no other choice. Fixes: 72b1e5e4cac7 ("netfilter: bridge: reduce nf_bridge_info to 32 bytes again") Reported-by: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-02flow_dissector: Use 'const' where possible.David S. Miller1-4/+4
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-02flow_dissector: Fix function argument ordering dependencyTom Herbert1-4/+4
Commit c6cc1ca7f4d70c ("flowi: Abstract out functions to get flow hash based on flowi") introduced a bug in __skb_set_sw_hash where we require a dependency on evaluating arguments in a function in order. There is no such ordering enforced in C, so this incorrect. This patch fixes that by splitting out the arguments. This bug was found via a compiler warning that keys may be uninitialized. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-02flow_dissector: Add flags argument to skb_flow_dissector functionsTom Herbert1-8/+11
The flags argument will allow control of the dissection process (for instance whether to parse beyond L3). Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-02flowi: Abstract out functions to get flow hash based on flowiTom Herbert1-4/+12
Create __get_hash_from_flowi6 and __get_hash_from_flowi4 to get the flow keys and hash based on flowi structures. These are called by __skb_get_hash_flowi6 and __skb_get_hash_flowi4. Also, created get_hash_from_flowi6 and get_hash_from_flowi4 which can be called when just the hash value for a flowi is needed. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-02skbuff: Make __skb_set_sw_hash a general functionTom Herbert1-16/+29
Move __skb_set_sw_hash to skbuff.h and add __skb_set_hash which is a common method (between __skb_set_sw_hash and skb_set_hash) to set the hash in an skbuff. Also, move skb_clear_hash to be closer to __skb_set_hash. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-02flow_dissector: Move skb related functions to skbuff.hTom Herbert1-0/+47
Move the flow dissector functions that are specific to skbuffs into skbuff.h out of flow_dissector.h. This makes flow_dissector.h have no dependencies on skbuff.h. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-9/+5
2015-08-22mm: make page pfmemalloc check more robustMichal Hocko1-9/+5
Commit c48a11c7ad26 ("netvm: propagate page->pfmemalloc to skb") added checks for page->pfmemalloc to __skb_fill_page_desc(): if (page->pfmemalloc && !page->mapping) skb->pfmemalloc = true; It assumes page->mapping == NULL implies that page->pfmemalloc can be trusted. However, __delete_from_page_cache() can set set page->mapping to NULL and leave page->index value alone. Due to being in union, a non-zero page->index will be interpreted as true page->pfmemalloc. So the assumption is invalid if the networking code can see such a page. And it seems it can. We have encountered this with a NFS over loopback setup when such a page is attached to a new skbuf. There is no copying going on in this case so the page confuses __skb_fill_page_desc which interprets the index as pfmemalloc flag and the network stack drops packets that have been allocated using the reserves unless they are to be queued on sockets handling the swapping which is the case here and that leads to hangs when the nfs client waits for a response from the server which has been dropped and thus never arrive. The struct page is already heavily packed so rather than finding another hole to put it in, let's do a trick instead. We can reuse the index again but define it to an impossible value (-1UL). This is the page index so it should never see the value that large. Replace all direct users of page->pfmemalloc by page_is_pfmemalloc which will hide this nastiness from unspoiled eyes. The information will get lost if somebody wants to use page->index obviously but that was the case before and the original code expected that the information should be persisted somewhere else if that is really needed (e.g. what SLAB and SLUB do). [akpm@linux-foundation.org: fix blooper in slub] Fixes: c48a11c7ad26 ("netvm: propagate page->pfmemalloc to skb") Signed-off-by: Michal Hocko <mhocko@suse.com> Debugged-by: Vlastimil Babka <vbabka@suse.com> Debugged-by: Jiri Bohac <jbohac@suse.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Miller <davem@davemloft.net> Acked-by: Mel Gorman <mgorman@suse.de> Cc: <stable@vger.kernel.org> [3.6+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-08-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-3/+3
Conflicts: drivers/net/ethernet/cavium/Kconfig The cavium conflict was overlapping dependency changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-10net-timestamp: Update skb_complete_tx_timestamp commentBenjamin Poirier1-3/+3
After "62bccb8 net-timestamp: Make the clone operation stand-alone from phy timestamping" the hwtstamps parameter of skb_complete_tx_timestamp() may no longer be NULL. Signed-off-by: Benjamin Poirier <bpoirier@suse.com> Cc: Alexander Duyck <alexander.h.duyck@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller1-6/+13
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for net-next, they are: 1) A couple of cleanups for the netfilter core hook from Eric Biederman. 2) Net namespace hook registration, also from Eric. This adds a dependency with the rtnl_lock. This should be fine by now but we have to keep an eye on this because if we ever get the per-subsys nfnl_lock before rtnl we have may problems in the future. But we have room to remove this in the future by propagating the complexity to the clients, by registering hooks for the init netns functions. 3) Update nf_tables to use the new net namespace hook infrastructure, also from Eric. 4) Three patches to refine and to address problems from the new net namespace hook infrastructure. 5) Switch to alternate jumpstack in xtables iff the packet is reentering. This only applies to a very special case, the TEE target, but Eric Dumazet reports that this is slowing down things for everyone else. So let's only switch to the alternate jumpstack if the tee target is in used through a static key. This batch also comes with offline precalculation of the jumpstack based on the callchain depth. From Florian Westphal. 6) Minimal SCTP multihoming support for our conntrack helper, from Michal Kubecek. 7) Reduce nf_bridge_info per skbuff scratchpad area to 32 bytes, from Florian Westphal. 8) Fix several checkpatch errors in bridge netfilter, from Bernhard Thaler. 9) Get rid of useless debug message in ip6t_REJECT, from Subash Abhinov. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-01net: Add functions to get skb->hash based on flow structuresTom Herbert1-0/+21
Add skb_get_hash_flowi6 and skb_get_hash_flowi4 which derive an sk_buff hash from flowi6 and flowi4 structures respectively. These functions can be called when creating a packet in the output path where the new sk_buff does not yet contain a fully formed packet that is parsable by flow dissector. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-30netfilter: bridge: reduce nf_bridge_info to 32 bytes againFlorian Westphal1-6/+13
We can use union for most of the temporary cruft (original ipv4/ipv6 address, source mac, physoutdev) since they're used during different stages of br netfilter traversal. Also get rid of the last two ->mask users. Shrinks struct from 48 to 32 on 64bit arch. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-07-21vxlan: Flow based tunnelingThomas Graf1-0/+1
Allows putting a VXLAN device into a new flow-based mode in which skbs with a ip_tunnel_info dst metadata attached will be encapsulated according to the instructions stored in there with the VXLAN device defaults taken into consideration. Similar on the receive side, if the VXLAN_F_COLLECT_METADATA flag is set, the packet processing will populate a ip_tunnel_info struct for each packet received and attach it to the skb using the new metadata dst. The metadata structure will contain the outer header and tunnel header fields which have been stripped off. Layers further up in the stack such as routing, tc or netfitler can later match on these fields and perform forwarding. It is the responsibility of upper layers to ensure that the flag is set if the metadata is needed. The flag limits the additional cost of metadata collecting based on demand. This prepares the VXLAN device to be steered by the routing and other subsystems which allows to support encapsulation for a large number of tunnel endpoints and tunnel ids through a single net_device which improves the scalability. It also allows for OVS to leverage this mode which in turn allows for the removal of the OVS specific VXLAN code. Because the skb is currently scrubed in vxlan_rcv(), the attachment of the new dst metadata is postponed until after scrubing which requires the temporary addition of a new member to vxlan_metadata. This member is removed again in a later commit after the indirect VXLAN receive API has been removed. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21net: remove skb_frag_add_headJiri Benc1-6/+0
It's not used anywhere. Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21net: don't reforward packets already forwarded by offload deviceScott Feldman1-1/+8
Just before queuing skb for xmit on port, check if skb has been marked by switchdev port driver as already fordwarded by device. If so, drop skb. A non-zero skb->offload_fwd_mark field is set by the switchdev port driver/device on ingress to indicate the skb has already been forwarded by the device to egress ports with matching dev->skb_mark. The switchdev port driver would assign a non-zero dev->offload_skb_mark for each device port netdev during registration, for example. Signed-off-by: Scott Feldman <sfeldma@gmail.com> Acked-by: Jiri Pirko <jiri@resnulli.us> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller1-1/+6
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next This a bit large (and late) patchset that contains Netfilter updates for net-next. Most relevantly br_netfilter fixes, ipset RCU support, removal of x_tables percpu ruleset copy and rework of the nf_tables netdev support. More specifically, they are: 1) Warn the user when there is a better protocol conntracker available, from Marcelo Ricardo Leitner. 2) Fix forwarding of IPv6 fragmented traffic in br_netfilter, from Bernhard Thaler. This comes with several patches to prepare the change in first place. 3) Get rid of special mtu handling of PPPoE/VLAN frames for br_netfilter. This is not needed anymore since now we use the largest fragment size to refragment, from Florian Westphal. 4) Restore vlan tag when refragmenting in br_netfilter, also from Florian. 5) Get rid of the percpu ruleset copy in x_tables, from Florian. Plus another follow up patch to refine it from Eric Dumazet. 6) Several ipset cleanups, fixes and finally RCU support, from Jozsef Kadlecsik. 7) Get rid of parens in Netfilter Kconfig files. 8) Attach the net_device to the basechain as opposed to the initial per table approach in the nf_tables netdev family. 9) Subscribe to netdev events to detect the removal and registration of a device that is referenced by a basechain. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>