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2015-01-18netlink: make nlmsg_end() and genlmsg_end() voidJohannes Berg
Contrary to common expectations for an "int" return, these functions return only a positive value -- if used correctly they cannot even return 0 because the message header will necessarily be in the skb. This makes the very common pattern of if (genlmsg_end(...) < 0) { ... } be a whole bunch of dead code. Many places also simply do return nlmsg_end(...); and the caller is expected to deal with it. This also commonly (at least for me) causes errors, because it is very common to write if (my_function(...)) /* error condition */ and if my_function() does "return nlmsg_end()" this is of course wrong. Additionally, there's not a single place in the kernel that actually needs the message length returned, and if anyone needs it later then it'll be very easy to just use skb->len there. Remove this, and make the functions void. This removes a bunch of dead code as described above. The patch adds lines because I did - return nlmsg_end(...); + nlmsg_end(...); + return 0; I could have preserved all the function's return values by returning skb->len, but instead I've audited all the places calling the affected functions and found that none cared. A few places actually compared the return value with <= 0 in dump functionality, but that could just be changed to < 0 with no change in behaviour, so I opted for the more efficient version. One instance of the error I've made numerous times now is also present in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't check for <0 or <=0 and thus broke out of the loop every single time. I've preserved this since it will (I think) have caused the messages to userspace to be formatted differently with just a single message for every SKB returned to userspace. It's possible that this isn't needed for the tools that actually use this, but I don't even know what they are so couldn't test that changing this behaviour would be acceptable. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/xen-netfront.c Minor overlapping changes in xen-netfront.c, mostly to do with some buffer management changes alongside the split of stats into TX and RX. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-13net: rename vlan_tx_* helpers since "tx" is misleading thereJiri Pirko
The same macros are used for rx as well. So rename it. Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-12packet: make packet too small warning match conditionWillem de Bruijn
The expression in ll_header_truncated() tests less than or equal, but the warning prints less than. Update the warning. Reported-by: Jouni Malinen <jkmalinen@gmail.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-11packet: bail out of packet_snd() if L2 header creation failsChristoph Jaeger
Due to a misplaced parenthesis, the expression (unlikely(offset) < 0), which expands to (__builtin_expect(!!(offset), 0) < 0), never evaluates to true. Therefore, when sending packets with PF_PACKET/SOCK_DGRAM, packet_snd() does not abort as intended if the creation of the layer 2 header fails. Spotted by Coverity - CID 1259975 ("Operands don't affect result"). Fixes: 9c7077622dd9 ("packet: make packet_snd fail on len smaller than l2 header") Signed-off-by: Christoph Jaeger <cj@linux.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-22packet: Fixed TPACKET V3 to signal poll when block is closed rather than ↵Dan Collins
every packet Make TPACKET_V3 signal poll when block is closed rather than for every packet. Side effect is that poll will be signaled when block retire timer expires which didn't previously happen. Issue was visible when sending packets at a very low frequency such that all blocks are retired before packets are received by TPACKET_V3. This caused avoidable packet loss. The fix ensures that the signal is sent when blocks are closed which covers the normal path where the block is filled as well as the path where the timer expires. The case where a block is filled without moving to the next block (ie. all blocks are full) will still cause poll to be signaled. Signed-off-by: Dan Collins <dan@dcollins.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) New offloading infrastructure and example 'rocker' driver for offloading of switching and routing to hardware. This work was done by a large group of dedicated individuals, not limited to: Scott Feldman, Jiri Pirko, Thomas Graf, John Fastabend, Jamal Hadi Salim, Andy Gospodarek, Florian Fainelli, Roopa Prabhu 2) Start making the networking operate on IOV iterators instead of modifying iov objects in-situ during transfers. Thanks to Al Viro and Herbert Xu. 3) A set of new netlink interfaces for the TIPC stack, from Richard Alpe. 4) Remove unnecessary looping during ipv6 routing lookups, from Martin KaFai Lau. 5) Add PAUSE frame generation support to gianfar driver, from Matei Pavaluca. 6) Allow for larger reordering levels in TCP, which are easily achievable in the real world right now, from Eric Dumazet. 7) Add a variable of napi_schedule that doesn't need to disable cpu interrupts, from Eric Dumazet. 8) Use a doubly linked list to optimize neigh_parms_release(), from Nicolas Dichtel. 9) Various enhancements to the kernel BPF verifier, and allow eBPF programs to actually be attached to sockets. From Alexei Starovoitov. 10) Support TSO/LSO in sunvnet driver, from David L Stevens. 11) Allow controlling ECN usage via routing metrics, from Florian Westphal. 12) Remote checksum offload, from Tom Herbert. 13) Add split-header receive, BQL, and xmit_more support to amd-xgbe driver, from Thomas Lendacky. 14) Add MPLS support to openvswitch, from Simon Horman. 15) Support wildcard tunnel endpoints in ipv6 tunnels, from Steffen Klassert. 16) Do gro flushes on a per-device basis using a timer, from Eric Dumazet. This tries to resolve the conflicting goals between the desired handling of bulk vs. RPC-like traffic. 17) Allow userspace to ask for the CPU upon what a packet was received/steered, via SO_INCOMING_CPU. From Eric Dumazet. 18) Limit GSO packets to half the current congestion window, from Eric Dumazet. 19) Add a generic helper so that all drivers set their RSS keys in a consistent way, from Eric Dumazet. 20) Add xmit_more support to enic driver, from Govindarajulu Varadarajan. 21) Add VLAN packet scheduler action, from Jiri Pirko. 22) Support configurable RSS hash functions via ethtool, from Eyal Perry. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1820 commits) Fix race condition between vxlan_sock_add and vxlan_sock_release net/macb: fix compilation warning for print_hex_dump() called with skb->mac_header net/mlx4: Add support for A0 steering net/mlx4: Refactor QUERY_PORT net/mlx4_core: Add explicit error message when rule doesn't meet configuration net/mlx4: Add A0 hybrid steering net/mlx4: Add mlx4_bitmap zone allocator net/mlx4: Add a check if there are too many reserved QPs net/mlx4: Change QP allocation scheme net/mlx4_core: Use tasklet for user-space CQ completion events net/mlx4_core: Mask out host side virtualization features for guests net/mlx4_en: Set csum level for encapsulated packets be2net: Export tunnel offloads only when a VxLAN tunnel is created gianfar: Fix dma check map error when DMA_API_DEBUG is enabled cxgb4/csiostor: Don't use MASTER_MUST for fw_hello call net: fec: only enable mdio interrupt before phy device link up net: fec: clear all interrupt events to support i.MX6SX net: fec: reset fep link status in suspend function net: sock: fix access via invalid file descriptor net: introduce helper macro for_each_cmsghdr ...
2014-12-09put iov_iter into msghdrAl Viro
Note that the code _using_ ->msg_iter at that point will be very unhappy with anything other than unshifted iovec-backed iov_iter. We still need to convert users to proper primitives. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-09af_packet: virtio 1.0 stubsMichael S. Tsirkin
This merely fixes sparse warnings, without actually adding support for the new APIs. Still working out the best way to enable the new functionality. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-11-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2014-11-24af_packet: fix sparse warningMichael S. Tsirkin
af_packet produces lots of these: net/packet/af_packet.c:384:39: warning: incorrect type in return expression (different modifiers) net/packet/af_packet.c:384:39: expected struct page [pure] * net/packet/af_packet.c:384:39: got struct page * this seems to be because sparse does not realize that _pure refers to function, not the returned pointer. Tweak code slightly to avoid the warning. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-24switch AF_PACKET and AF_UNIX to skb_copy_datagram_from_iter()Al Viro
... and kill skb_copy_datagram_iovec() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-24new helper: memcpy_to_msg()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-24new helper: memcpy_from_msg()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-21packet: make packet_snd fail on len smaller than l2 headerWillem de Bruijn
When sending packets out with PF_PACKET, SOCK_RAW, ensure that the packet is at least as long as the device's expected link layer header. This check already exists in tpacket_snd, but not in packet_snd. Also rate limit the warning in tpacket_snd. Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-05net: Add and use skb_copy_datagram_msg() helper.David S. Miller
This encapsulates all of the skb_copy_datagram_iovec() callers with call argument signature "skb, offset, msghdr->msg_iov, length". When we move to iov_iters in the networking, the iov_iter object will sit in the msghdr. Having a helper like this means there will be less places to touch during that transformation. Based upon descriptions and patch from Al Viro. Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-01net: Pass a "more" indication down into netdev_start_xmit() code paths.David S. Miller
For now it will always be false. Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-01net: Do txq_trans_update() in netdev_start_xmit()David S. Miller
That way we don't have to audit every call site to make sure it is doing this properly. Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-29net: add skb_get_tx_queue() helperDaniel Borkmann
Replace occurences of skb_get_queue_mapping() and follow-up netdev_get_tx_queue() with an actual helper function. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-24net: Add ops->ndo_xmit_flush()David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-21packet: handle too big packets for PACKET_V3Eric Dumazet
af_packet can currently overwrite kernel memory by out of bound accesses, because it assumed a [new] block can always hold one frame. This is not generally the case, even if most existing tools do it right. This patch clamps too long frames as API permits, and issue a one time error on syslog. [ 394.357639] tpacket_rcv: packet too big, clamped from 5042 to 3966. macoff=82 In this example, packet header tp_snaplen was set to 3966, and tp_len was set to 5042 (skb->len) Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.") Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-29packet: remove deprecated syststamp timestampWillem de Bruijn
No device driver will ever return an skb_shared_info structure with syststamp non-zero, so remove the branch that tests for this and optionally marks the packet timestamp as TP_STATUS_TS_SYS_HARDWARE. Do not remove the definition TP_STATUS_TS_SYS_HARDWARE, as processes may refer to it. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-15packet: remove unnecessary break after returnFabian Frederick
Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-24net: Use netlink_ns_capable to verify the permisions of netlink messagesEric W. Biederman
It is possible by passing a netlink socket to a more privileged executable and then to fool that executable into writing to the socket data that happens to be valid netlink message to do something that privileged executable did not intend to do. To keep this from happening replace bare capable and ns_capable calls with netlink_capable, netlink_net_calls and netlink_ns_capable calls. Which act the same as the previous calls except they verify that the opener of the socket had the desired permissions as well. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-24net: Move the permission check in sock_diag_put_filterinfo to packet_diag_dumpEric W. Biederman
The permission check in sock_diag_put_filterinfo is wrong, and it is so removed from it's sources it is not clear why it is wrong. Move the computation into packet_diag_dump and pass a bool of the result into sock_diag_filterinfo. This does not yet correct the capability check but instead simply moves it to make it clear what is going on. Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-22net: Fix ns_capable check in sock_diag_put_filterinfoAndrew Lutomirski
The caller needs capabilities on the namespace being queried, not on their own namespace. This is a security bug, although it likely has only a minor impact. Cc: stable@vger.kernel.org Signed-off-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-11net: Fix use after free by removing length arg from sk_data_ready callbacks.David S. Miller
Several spots in the kernel perform a sequence like: skb_queue_tail(&sk->s_receive_queue, skb); sk->sk_data_ready(sk, skb->len); But at the moment we place the SKB onto the socket receive queue it can be consumed and freed up. So this skb->len access is potentially to freed up memory. Furthermore, the skb->len can be modified by the consumer so it is possible that the value isn't accurate. And finally, no actual implementation of this callback actually uses the length argument. And since nobody actually cared about it's value, lots of call sites pass arbitrary values in such as '0' and even '1'. So just remove the length argument from the callback, that way there is no confusion whatsoever and all of these use-after-free cases get fixed as a side effect. Based upon a patch by Eric Dumazet and his suggestion to audit this issue tree-wide. Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-03packet: fix packet_direct_xmit for BQL enabled driversDaniel Borkmann
Currently, in packet_direct_xmit() we test the assigned netdevice queue for netif_xmit_frozen_or_stopped() before doing an ndo_start_xmit(). This can have the side-effect that BQL enabled drivers which make use of netdev_tx_sent_queue() internally, set __QUEUE_STATE_STACK_XOFF from within the stack and would not fully fill the device's TX ring from packet sockets with PACKET_QDISC_BYPASS enabled. Instead, use a test without BQL bit so that bursts can be absorbed into the NICs TX ring. Fix and code suggested by Eric Dumazet, thanks! Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-03packet: report tx_dropped in packet_direct_xmitDaniel Borkmann
Since commit 015f0688f57c ("net: net: add a core netdev->tx_dropped counter"), we can now account for TX drops from within the core stack instead of drivers. Therefore, fix packet_direct_xmit() and increase drop count when we encounter a problem before driver's xmit function was called (we do not want to doubly account for it). Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-28packet: respect devices with LLTX flag in direct xmitDaniel Borkmann
Quite often it can be useful to test with dummy or similar devices as a blackhole sink for skbs. Such devices are only equipped with a single txq, but marked as NETIF_F_LLTX as they do not require locking their internal queues on xmit (or implement locking themselves). Therefore, rather use HARD_TX_{UN,}LOCK API, so that NETIF_F_LLTX will be respected. trafgen mmap/TX_RING example against dummy device with config foo: { fill(0xff, 64) } results in the following performance improvements for such scenarios on an ordinary Core i7/2.80GHz: Before: Performance counter stats for 'trafgen -i foo -o du0 -n100000000' (10 runs): 160,975,944,159 instructions:k # 0.55 insns per cycle ( +- 0.09% ) 293,319,390,278 cycles:k # 0.000 GHz ( +- 0.35% ) 192,501,104 branch-misses:k ( +- 1.63% ) 831 context-switches:k ( +- 9.18% ) 7 cpu-migrations:k ( +- 7.40% ) 69,382 cache-misses:k # 0.010 % of all cache refs ( +- 2.18% ) 671,552,021 cache-references:k ( +- 1.29% ) 22.856401569 seconds time elapsed ( +- 0.33% ) After: Performance counter stats for 'trafgen -i foo -o du0 -n100000000' (10 runs): 133,788,739,692 instructions:k # 0.92 insns per cycle ( +- 0.06% ) 145,853,213,256 cycles:k # 0.000 GHz ( +- 0.17% ) 59,867,100 branch-misses:k ( +- 4.72% ) 384 context-switches:k ( +- 3.76% ) 6 cpu-migrations:k ( +- 6.28% ) 70,304 cache-misses:k # 0.077 % of all cache refs ( +- 1.73% ) 90,879,408 cache-references:k ( +- 1.35% ) 11.719372413 seconds time elapsed ( +- 0.24% ) Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-26net: Rename skb->rxhash to skb->hashTom Herbert
The packet hash can be considered a property of the packet, not just on RX path. This patch changes name of rxhash and l4_rxhash skbuff fields to be hash and l4_hash respectively. This includes changing uses of the field in the code which don't call the access functions. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Mahesh Bandewar <maheshb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-28packet: allow to transmit +4 byte in TX_RING slot for VLAN caseDaniel Borkmann
Commit 57f89bfa2140 ("network: Allow af_packet to transmit +4 bytes for VLAN packets.") added the possibility for non-mmaped frames to send extra 4 byte for VLAN header so the MTU increases from 1500 to 1504 byte, for example. Commit cbd89acb9eb2 ("af_packet: fix for sending VLAN frames via packet_mmap") attempted to fix that for the mmap part but was reverted as it caused regressions while using eth_type_trans() on output path. Lets just act analogous to 57f89bfa2140 and add a similar logic to TX_RING. We presume size_max as overcharged with +4 bytes and later on after skb has been built by tpacket_fill_skb() check for ETH_P_8021Q header on packets larger than normal MTU. Can be easily reproduced with a slightly modified trafgen in mmap(2) mode, test cases: { fill(0xff, 12) const16(0x8100) fill(0xff, <1504|1505>) } { fill(0xff, 12) const16(0x0806) fill(0xff, <1500|1501>) } Note that we need to do the test right after tpacket_fill_skb() as sockets can have PACKET_LOSS set where we would not fail but instead just continue to traverse the ring. Reported-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Ben Greear <greearb@candelatech.com> Cc: Phil Sutter <phil@nwl.cc> Tested-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-18af_packet: remove a stray tab in packet_set_ring()Dan Carpenter
At first glance it looks like there is a missing curly brace but actually the code works the same either way. I have adjusted the indenting but left the code the same. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-17packet: check for ndo_select_queue during queue selectionDaniel Borkmann
Mathias reported that on an AMD Geode LX embedded board (ALiX) with ath9k driver PACKET_QDISC_BYPASS, introduced in commit d346a3fae3ff ("packet: introduce PACKET_QDISC_BYPASS socket option"), triggers a WARN_ON() coming from the driver itself via 066dae93bdf ("ath9k: rework tx queue selection and fix queue stopping/waking"). The reason why this happened is that ndo_select_queue() call is not invoked from direct xmit path i.e. for ieee80211 subsystem that sets queue and TID (similar to 802.1d tag) which is being put into the frame through 802.11e (WMM, QoS). If that is not set, pending frame counter for e.g. ath9k can get messed up. So the WARN_ON() in ath9k is absolutely legitimate. Generally, the hw queue selection in ieee80211 depends on the type of traffic, and priorities are set according to ieee80211_ac_numbers mapping; working in a similar way as DiffServ only on a lower layer, so that the AP can favour frames that have "real-time" requirements like voice or video data frames. Therefore, check for presence of ndo_select_queue() in netdev ops and, if available, invoke it with a fallback handler to __packet_pick_tx_queue(), so that driver such as bnx2x, ixgbe, or mlx4 can still select a hw queue for transmission in relation to the current CPU while e.g. ieee80211 subsystem can make their own choices. Reported-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-22af_packet: Add Queue mapping mode to af_packet fanout operationNeil Horman
This patch adds a queue mapping mode to the fanout operation of af_packet sockets. This allows user space af_packet users to better filter on flows ingressing and egressing via a specific hardware queue, and avoids the potential packet reordering that can occur when FANOUT_CPU is being used and irq affinity varies. Tested successfully by myself. applies to net-next Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: "David S. Miller" <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-21net: introduce reciprocal_scale helper and convert usersDaniel Borkmann
As David Laight suggests, we shouldn't necessarily call this reciprocal_divide() when users didn't requested a reciprocal_value(); lets keep the basic idea and call it reciprocal_scale(). More background information on this topic can be found in [1]. Joint work with Hannes Frederic Sowa. [1] http://homepage.cs.uiowa.edu/~jones/bcd/divide.html Suggested-by: David Laight <david.laight@aculab.com> Cc: Jakub Zawadzki <darkjames-ws@darkjames.pl> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-21random32: add prandom_u32_max and convert open coded usersDaniel Borkmann
Many functions have open coded a function that returns a random number in range [0,N-1]. Under the assumption that we have a PRNG such as taus113 with being well distributed in [0, ~0U] space, we can implement such a function as uword t = (n*m')>>32, where m' is a random number obtained from PRNG, n the right open interval border and t our resulting random number, with n,m',t in u32 universe. Lets go with Joe and simply call it prandom_u32_max(), although technically we have an right open interval endpoint, but that we have documented. Other users can further be migrated to the new prandom_u32_max() function later on; for now, we need to make sure to migrate reciprocal_divide() users for the reciprocal_divide() follow-up fixup since their function signatures are going to change. Joint work with Hannes Frederic Sowa. Cc: Jakub Zawadzki <darkjames-ws@darkjames.pl> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-21packet: fix a couple of cppcheck warningsDaniel Borkmann
Doesn't bring much, but also doesn't hurt us to fix 'em: 1) In tpacket_rcv() flush dcache page we can restirct the scope for start and end and remove one layer of indent. 2) In tpacket_destruct_skb() we can restirct the scope for ph. 3) In alloc_one_pg_vec_page() we can remove the NULL assignment and change spacing a bit. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-18net: add build-time checks for msg->msg_name sizeSteffen Hurrle
This is a follow-up patch to f3d3342602f8bc ("net: rework recvmsg handler msg_name and msg_namelen logic"). DECLARE_SOCKADDR validates that the structure we use for writing the name information to is not larger than the buffer which is reserved for msg->msg_name (which is 128 bytes). Also use DECLARE_SOCKADDR consistently in sendmsg code paths. Signed-off-by: Steffen Hurrle <steffen@hurrle.net> Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-16packet: use percpu mmap tx frame pending refcountDaniel Borkmann
In PF_PACKET's packet mmap(), we can avoid using one atomic_inc() and one atomic_dec() call in skb destructor and use a percpu reference count instead in order to determine if packets are still pending to be sent out. Micro-benchmark with [1] that has been slightly modified (that is, protcol = 0 in socket(2) and bind(2)), example on a rather crappy testing machine; I expect it to scale and have even better results on bigger machines: ./packet_mm_tx -s7000 -m7200 -z700000 em1, avg over 2500 runs: With patch: 4,022,015 cyc Without patch: 4,812,994 cyc time ./packet_mm_tx -s64 -c10000000 em1 > /dev/null, stable: With patch: real 1m32.241s user 0m0.287s sys 1m29.316s Without patch: real 1m38.386s user 0m0.265s sys 1m35.572s In function tpacket_snd(), it is okay to use packet_read_pending() since in fast-path we short-circuit the condition already with ph != NULL, since we have next frames to process. In case we have MSG_DONTWAIT, we also do not execute this path as need_wait is false here anyway, and in case of _no_ MSG_DONTWAIT flag, it is okay to call a packet_read_pending(), because when we ever reach that path, we're done processing outgoing frames anyway and only look if there are skbs still outstanding to be orphaned. We can stay lockless in this percpu counter since it's acceptable when we reach this path for the sum to be imprecise first, but we'll level out at 0 after all pending frames have reached the skb destructor eventually through tx reclaim. When people pin a tx process to particular CPUs, we expect overflows to happen in the reference counter as on one CPU we expect heavy increase; and distributed through ksoftirqd on all CPUs a decrease, for example. As David Laight points out, since the C language doesn't define the result of signed int overflow (i.e. rather than wrap, it is allowed to saturate as a possible outcome), we have to use unsigned int as reference count. The sum over all CPUs when tx is complete will result in 0 again. The BUG_ON() in tpacket_destruct_skb() we can remove as well. It can _only_ be set from inside tpacket_snd() path and we made sure to increase tx_ring.pending in any case before we called po->xmit(skb). So testing for tx_ring.pending == 0 is not too useful. Instead, it would rather have been useful to test if lower layers didn't orphan the skb so that we're missing ring slots being put back to TP_STATUS_AVAILABLE. But such a bug will be caught in user space already as we end up realizing that we do not have any TP_STATUS_AVAILABLE slots left anymore. Therefore, we're all set. Btw, in case of RX_RING path, we do not make use of the pending member, therefore we also don't need to use up any percpu memory here. Also note that __alloc_percpu() already returns a zero-filled percpu area, so initialization is done already. [1] http://wiki.ipxwarzone.com/index.php5?title=Linux_packet_mmap Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-16packet: don't unconditionally schedule() in case of MSG_DONTWAITDaniel Borkmann
In tpacket_snd(), when we've discovered a first frame that is not in status TP_STATUS_SEND_REQUEST, and return a NULL buffer, we exit the send routine in case of MSG_DONTWAIT, since we've finished traversing the mmaped send ring buffer and don't care about pending frames. While doing so, we still unconditionally call an expensive schedule() in the packet_current_frame() "error" path, which is unnecessary in this case since it's enough to just quit the function. Also, in case MSG_DONTWAIT is not set, we should rather test for need_resched() first and do schedule() only if necessary since meanwhile pending frames could already have finished processing and called skb destructor. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-16packet: improve socket create/bind latency in some casesDaniel Borkmann
Most people acquire PF_PACKET sockets with a protocol argument in the socket call, e.g. libpcap does so with htons(ETH_P_ALL) for all its sockets. Most likely, at some point in time a subsequent bind() call will follow, e.g. in libpcap with ... memset(&sll, 0, sizeof(sll)); sll.sll_family = AF_PACKET; sll.sll_ifindex = ifindex; sll.sll_protocol = htons(ETH_P_ALL); ... as arguments. What happens in the kernel is that already in socket() syscall, we install a proto hook via register_prot_hook() if our protocol argument is != 0. Yet, in bind() we're almost doing the same work by doing a unregister_prot_hook() with an expensive synchronize_net() call in case during socket() the proto was != 0, plus follow-up register_prot_hook() with a bound device to it this time, in order to limit traffic we get. In the case when the protocol and user supplied device index (== 0) does not change from socket() to bind(), we can spare us doing the same work twice. Similarly for re-binding to the same device and protocol. For these scenarios, we can decrease create/bind latency from ~7447us (sock-bind-2 case) to ~89us (sock-bind-1 case) with this patch. Alternatively, for the first case, if people care, they should simply create their sockets with proto == 0 argument and define the protocol during bind() as this saves a call to synchronize_net() as well (sock-bind-3 case). In all other cases, we're tied to user space behaviour we must not change, also since a bind() is not strictly required. Thus, we need the synchronize_net() to make sure no asynchronous packet processing paths still refer to the previous elements of po->prot_hook. In case of mmap()ed sockets, the workflow that includes bind() is socket() -> setsockopt(<ring>) -> bind(). In that case, a pair of {__unregister, register}_prot_hook is being called from setsockopt() in order to install the new protocol receive handler. Thus, when we call bind and can skip a re-hook, we have already previously installed the new handler. For fanout, this is handled different entirely, so we should be good. Timings on an i7-3520M machine: * sock-bind-1: 89 us * sock-bind-2: 7447 us * sock-bind-3: 75 us sock-bind-1: socket(PF_PACKET, SOCK_RAW, htons(ETH_P_IP)) = 3 bind(3, {sa_family=AF_PACKET, proto=htons(ETH_P_IP), if=all(0), pkttype=PACKET_HOST, addr(0)={0, }, 20) = 0 sock-bind-2: socket(PF_PACKET, SOCK_RAW, htons(ETH_P_IP)) = 3 bind(3, {sa_family=AF_PACKET, proto=htons(ETH_P_IP), if=lo(1), pkttype=PACKET_HOST, addr(0)={0, }, 20) = 0 sock-bind-3: socket(PF_PACKET, SOCK_RAW, 0) = 3 bind(3, {sa_family=AF_PACKET, proto=htons(ETH_P_IP), if=lo(1), pkttype=PACKET_HOST, addr(0)={0, }, 20) = 0 Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-31packet: fix "foo * bar" and "(foo*)" problemsWeilong Chen
Cleanup checkpatch errors.Specially,the second changed line is exactly 80 columns long. Signed-off-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-18packet: deliver VLAN TPID to userspaceAtzm Watanabe
This enables userspace to get VLAN TPID as well as the VLAN TCI. Signed-off-by: Atzm Watanabe <atzm@stratosphere.co.jp> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-18packet: fill the gap of TPACKET_ALIGNMENT with zerosAtzm Watanabe
struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. Explicitly defining and zeroing the gap of this makes additional changes easier. Signed-off-by: Atzm Watanabe <atzm@stratosphere.co.jp> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-18packet: make aligned size of struct tpacket{2,3}_hdr clearAtzm Watanabe
struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT. We may add members to them until current aligned size without forcing userspace to call getsockopt(..., PACKET_HDRLEN, ...). Signed-off-by: Atzm Watanabe <atzm@stratosphere.co.jp> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-17net: Change skb_get_rxhash to skb_get_hashTom Herbert
Changing name of function as part of making the hash in skbuff to be generic property, not just for receive path. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-14packet: fix using smp_processor_id() in preemptible codeLi Zhong
This patches fixes the following warning by replacing smp_processor_id() with raw_smp_processor_id(): [ 11.120893] BUG: using smp_processor_id() in preemptible [00000000] code: arping/3510 [ 11.120913] caller is .packet_sendmsg+0xc14/0xe68 [ 11.120920] CPU: 13 PID: 3510 Comm: arping Not tainted 3.13.0-rc3-next-20131211-dirty #1 [ 11.120926] Call Trace: [ 11.120932] [c0000001f803f6f0] [c0000000000138dc] .show_stack+0x110/0x25c (unreliable) [ 11.120942] [c0000001f803f7e0] [c00000000083dd24] .dump_stack+0xa0/0x37c [ 11.120951] [c0000001f803f870] [c000000000493fd4] .debug_smp_processor_id+0xfc/0x12c [ 11.120959] [c0000001f803f900] [c0000000007eba78] .packet_sendmsg+0xc14/0xe68 [ 11.120968] [c0000001f803fa80] [c000000000700968] .sock_sendmsg+0xa0/0xe0 [ 11.120975] [c0000001f803fbf0] [c0000000007014d8] .SyS_sendto+0x100/0x148 [ 11.120983] [c0000001f803fd60] [c0000000006fff10] .SyS_socketcall+0x1c4/0x2e8 [ 11.120990] [c0000001f803fe30] [c00000000000a1e4] syscall_exit+0x0/0x9c Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-09packet: introduce PACKET_QDISC_BYPASS socket optionDaniel Borkmann
This patch introduces a PACKET_QDISC_BYPASS socket option, that allows for using a similar xmit() function as in pktgen instead of taking the dev_queue_xmit() path. This can be very useful when PF_PACKET applications are required to be used in a similar scenario as pktgen, but with full, flexible packet payload that needs to be provided, for example. On default, nothing changes in behaviour for normal PF_PACKET TX users, so everything stays as is for applications. New users, however, can now set PACKET_QDISC_BYPASS if needed to prevent own packets from i) reentering packet_rcv() and ii) to directly push the frame to the driver. In doing so we can increase pps (here 64 byte packets) for PF_PACKET a bit: # CPUs -- QDISC_BYPASS -- qdisc path -- qdisc path[**] 1 CPU == 1,509,628 pps -- 1,208,708 -- 1,247,436 2 CPUs == 3,198,659 pps -- 2,536,012 -- 1,605,779 3 CPUs == 4,787,992 pps -- 3,788,740 -- 1,735,610 4 CPUs == 6,173,956 pps -- 4,907,799 -- 1,909,114 5 CPUs == 7,495,676 pps -- 5,956,499 -- 2,014,422 6 CPUs == 9,001,496 pps -- 7,145,064 -- 2,155,261 7 CPUs == 10,229,776 pps -- 8,190,596 -- 2,220,619 8 CPUs == 11,040,732 pps -- 9,188,544 -- 2,241,879 9 CPUs == 12,009,076 pps -- 10,275,936 -- 2,068,447 10 CPUs == 11,380,052 pps -- 11,265,337 -- 1,578,689 11 CPUs == 11,672,676 pps -- 11,845,344 -- 1,297,412 [...] 20 CPUs == 11,363,192 pps -- 11,014,933 -- 1,245,081 [**]: qdisc path with packet_rcv(), how probably most people seem to use it (hopefully not anymore if not needed) The test was done using a modified trafgen, sending a simple static 64 bytes packet, on all CPUs. The trick in the fast "qdisc path" case, is to avoid reentering packet_rcv() by setting the RAW socket protocol to zero, like: socket(PF_PACKET, SOCK_RAW, 0); Tradeoffs are documented as well in this patch, clearly, if queues are busy, we will drop more packets, tc disciplines are ignored, and these packets are not visible to taps anymore. For a pktgen like scenario, we argue that this is acceptable. The pointer to the xmit function has been placed in packet socket structure hole between cached_dev and prot_hook that is hot anyway as we're working on cached_dev in each send path. Done in joint work together with Jesper Dangaard Brouer. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Merge 'net' into 'net-next' to get the AF_PACKET bug fix that Daniel's direct transmit changes depend upon. Signed-off-by: David S. Miller <davem@davemloft.net>