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path: root/drivers/net/xen-netback
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2013-12-17xen-netback: fix fragments error handling in checksum_setup_ip()Wei Yongjun
Fix to return -EPROTO error if fragments detected in checksum_setup_ip(). Fixes: 1431fb31ecba ('xen-netback: fix fragment detection in checksum setup') Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-12xen-netback: fix gso_prefix checkPaul Durrant
There is a mistake in checking the gso_prefix mask when passing large packets to a guest. The wrong shift is applied to the bit - the raw skb gso type is used rather then the translated one. This leads to large packets being handed to the guest without the GSO metadata. This patch fixes the check. The mistake manifested as errors whilst running Microsoft HCK large packet offload tests between a pair of Windows 8 VMs. I have verified this patch fixes those errors. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-12xen-netback: napi: don't prematurely request a tx eventPaul Durrant
This patch changes the RING_FINAL_CHECK_FOR_REQUESTS in xenvif_build_tx_gops to a check for RING_HAS_UNCONSUMED_REQUESTS as the former call has the side effect of advancing the ring event pointer and therefore inviting another interrupt from the frontend before the napi poll has actually finished, thereby defeating the point of napi. The event pointer is updated by RING_FINAL_CHECK_FOR_REQUESTS in xenvif_poll, the napi poll function, if the work done is less than the budget i.e. when actually transitioning back to interrupt mode. Reported-by: Malcolm Crossley <malcolm.crossley@citrix.com> Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-12xen-netback: napi: fix abuse of budgetPaul Durrant
netback seems to be somewhat confused about the napi budget parameter. The parameter is supposed to limit the number of skbs processed in each poll, but netback has this confused with grant operations. This patch fixes that, properly limiting the work done in each poll. Note that this limit makes sure we do not process any more data from the shared ring than we intend to pass back from the poll. This is important to prevent tx_queue potentially growing without bound. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-11xen-netback: make sure skb linear area covers checksum fieldPaul Durrant
skb_partial_csum_set requires that the linear area of the skb covers the checksum field. The checksum setup code in netback was only doing that pullup in the case when the pseudo header checksum was being recalculated though. This patch makes that pullup unconditional. (I pullup the whole transport header just for simplicity; the requirement is only for the check field but in the case of UDP this is the last field in the header and in the case of TCP it's the last but one). The lack of pullup manifested as failures running Microsoft HCK network tests on a pair of Windows 8 VMs and it has been verified that this patch fixes the problem. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-05xen-netback: fix fragment detection in checksum setupPaul Durrant
The code to detect fragments in checksum_setup() was missing for IPv4 and too eager for IPv6. (It transpires that Windows seems to send IPv6 packets with a fragment header even if they are not a fragment - i.e. offset is zero, and M bit is not set). This patch also incorporates a fix to callers of maybe_pull_tail() where skb->network_header was being erroneously added to the length argument. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> cc: David Miller <davem@davemloft.net> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-03xen-netback: clear vif->task on disconnectPaul Durrant
xenvif_start_xmit() relies on checking vif->task for NULL to determine whether the vif is ready to accept packets. The task thread is stopped in xenvif_disconnect() but task is not set to NULL. Thus, on a re-connect the check will give a false positive. Also since commit ea732dff5cfa10789007bf4a5b935388a0bb2a8f (Handle backend state transitions in a more robust way) it should not be possible for xenvif_connect() to be called if the vif is already connected so change the check of vif->tx_irq to a BUG_ON() and also add a BUG_ON(vif->task). Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-28xen-netback: include definition of csum_ipv6_magicAndy Whitcroft
We are now using csum_ipv6_magic, include the appropriate header. Avoids the following error: drivers/net/xen-netback/netback.c:1313:4: error: implicit declaration of function 'csum_ipv6_magic' [-Werror=implicit-function-declaration] tcph->check = ~csum_ipv6_magic(&ipv6h->saddr, Signed-off-by: Andy Whitcroft <apw@canonical.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-21xen-netback: stop the VIF thread before unbinding IRQsDavid Vrabel
If the VIF thread is still running after unbinding the Tx and Rx IRQs in xenvif_disconnect(), the thread may attempt to raise an event which will BUG (as the irq is unbound). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/ethernet/emulex/benet/be.h drivers/net/netconsole.c net/bridge/br_private.h Three mostly trivial conflicts. The net/bridge/br_private.h conflict was a function signature (argument addition) change overlapping with the extern removals from Joe Perches. In drivers/net/netconsole.c we had one change adjusting a printk message whilst another changed "printk(KERN_INFO" into "pr_info(". Lastly, the emulex change was a new inline function addition overlapping with Joe Perches's extern removals. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-29xen-netback: use jiffies_64 value to calculate credit timeoutWei Liu
time_after_eq() only works if the delta is < MAX_ULONG/2. For a 32bit Dom0, if netfront sends packets at a very low rate, the time between subsequent calls to tx_credit_exceeded() may exceed MAX_ULONG/2 and the test for timer_after_eq() will be incorrect. Credit will not be replenished and the guest may become unable to send packets (e.g., if prior to the long gap, all credit was exhausted). Use jiffies_64 variant to mitigate this problem for 32bit Dom0. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Reviewed-by: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Jason Luan <jianhai.luan@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-17xen-netback: enable IPv6 TCP GSO to the guestPaul Durrant
This patch adds code to handle SKB_GSO_TCPV6 skbs and construct appropriate extra or prefix segments to pass the large packet to the frontend. New xenstore flags, feature-gso-tcpv6 and feature-gso-tcpv6-prefix, are sampled to determine if the frontend is capable of handling such packets. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-17xen-netback: handle IPv6 TCP GSO packets from the guestPaul Durrant
This patch adds a xenstore feature flag, festure-gso-tcpv6, to advertise that netback can handle IPv6 TCP GSO packets. It creates SKB_GSO_TCPV6 skbs if the frontend passes an extra segment with the new type XEN_NETIF_GSO_TYPE_TCPV6 added to netif.h. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-17xen-netback: Unconditionally set NETIF_F_RXCSUMPaul Durrant
There is no mechanism to insist that a guest always generates a packet with good checksum (at least for IPv4) so we must handle checksum offloading from the guest and hence should set NETIF_F_RXCSUM. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-17xen-netback: add support for IPv6 checksum offload from guestPaul Durrant
For performance of VM to VM traffic on a single host it is better to avoid calculation of TCP/UDP checksum in the sending frontend. To allow this this patch adds the code necessary to set up partial checksum for IPv6 packets and xenstore flag feature-ipv6-csum-offload to advertise that fact to frontends. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-17xen-netback: add support for IPv6 checksum offload to guestPaul Durrant
Check xenstore flag feature-ipv6-csum-offload to determine if a guest is happy to accept IPv6 packets with only partial checksum. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-08xen-netback: transition to CLOSED when removing a VIFDavid Vrabel
If a guest is destroyed without transitioning its frontend to CLOSED, the domain becomes a zombie as netback was not grant unmapping the shared rings. When removing a VIF, transition the backend to CLOSED so the VIF is disconnected if necessary (which will unmap the shared rings etc). This fixes a regression introduced by 279f438e36c0a70b23b86d2090aeec50155034a9 (xen-netback: Don't destroy the netdev until the vif is shut down). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Paul Durrant <Paul.Durrant@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-30xen-netback: Handle backend state transitions in a more robust wayPaul Durrant
When the frontend state changes netback now specifies its desired state to a new function, set_backend_state(), which transitions through any necessary intermediate states. This fixes an issue observed with some old Windows frontend drivers where they failed to transition through the Closing state and netback would not behave correctly. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-19xen-netback: Don't destroy the netdev until the vif is shut downPaul Durrant
Without this patch, if a frontend cycles through states Closing and Closed (which Windows frontends need to do) then the netdev will be destroyed and requires re-invocation of hotplug scripts to restore state before the frontend can move to Connected. Thus when udev is not in use the backend gets stuck in InitWait. With this patch, the netdev is left alone whilst the backend is still online and is only de-registered and freed just prior to destroying the vif (which is also nicely symmetrical with the netdev allocation and registration being done during probe) so no re-invocation of hotplug scripts is required. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Wei Liu <wei.liu2@citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Acked-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-12xen-netback: count number required slots for an skb more carefullyDavid Vrabel
When a VM is providing an iSCSI target and the LUN is used by the backend domain, the generated skbs for direct I/O writes to the disk have large, multi-page skb->data but no frags. With some lengths and starting offsets, xen_netbk_count_skb_slots() would be one short because the simple calculation of DIV_ROUND_UP(skb_headlen(), PAGE_SIZE) was not accounting for the decisions made by start_new_rx_buffer() which does not guarantee responses are fully packed. For example, a skb with length < 2 pages but which spans 3 pages would be counted as requiring 2 slots but would actually use 3 slots. skb->data: | 1111|222222222222|3333 | Fully packed, this would need 2 slots: |111122222222|22223333 | But because the 2nd page wholy fits into a slot it is not split across slots and goes into a slot of its own: |1111 |222222222222|3333 | Miscounting the number of slots means netback may push more responses than the number of available requests. This will cause the frontend to get very confused and report "Too many frags/slots". The frontend never recovers and will eventually BUG. Fix this by counting the number of required slots more carefully. In xen_netbk_count_skb_slots(), more closely follow the algorithm used by xen_netbk_gop_skb() by introducing xen_netbk_count_frag_slots() which is the dry-run equivalent of netbk_gop_frag_copy(). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-12xen-netback: fix possible format string flawKees Cook
This makes sure a format string cannot accidentally leak into the kthread_run() call. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-29xen-netback: rename functionsWei Liu
As we move to 1:1 model and melt xen_netbk and xenvif together, it would be better to use single prefix for all functions in xen-netback. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-29xen-netback: switch to NAPI + kthread 1:1 modelWei Liu
This patch implements 1:1 model netback. NAPI and kthread are utilized to do the weight-lifting job: - NAPI is used for guest side TX (host side RX) - kthread is used for guest side RX (host side TX) Xenvif and xen_netbk are made into one structure to reduce code size. This model provides better scheduling fairness among vifs. It is also prerequisite for implementing multiqueue for Xen netback. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-29xen-netback: remove page tracking facilityWei Liu
The data flow from DomU to DomU on the same host in current copying scheme with tracking facility: copy DomU --------> Dom0 DomU | ^ |____________________________| copy The page in Dom0 is a page with valid MFN. So we can always copy from page Dom0, thus removing the need for a tracking facility. copy copy DomU --------> Dom0 -------> DomU Simple iperf test shows no performance regression (obviously we copy twice either way): W/ tracking: ~5.3Gb/s W/o tracking: ~5.4Gb/s Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Matt Wilson <msw@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-02xen-netback: xenbus.c: use more current logging stylesWei Liu
Convert one printk to pr_<level>. Add a missing newline in several places to avoid message interleaving, coalesce formats, reflow modified lines to 80 columns. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-01xen: Use more current logging stylesJoe Perches
Instead of mixing printk and pr_<level> forms, just use pr_<level> Miscellaneous changes around these conversions: Add a missing newline to avoid message interleaving, coalesce formats, reflow modified lines to 80 columns. Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-24xen-netback: double free on unloadDan Carpenter
There is a typo here, "i" vs "j", so we would crash on module_exit(). Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/wireless/ath/ath9k/Kconfig drivers/net/xen-netback/netback.c net/batman-adv/bat_iv_ogm.c net/wireless/nl80211.c The ath9k Kconfig conflict was a change of a Kconfig option name right next to the deletion of another option. The xen-netback conflict was overlapping changes involving the handling of the notify list in xen_netbk_rx_action(). Batman conflict resolution provided by Antonio Quartulli, basically keep everything in both conflict hunks. The nl80211 conflict is a little more involved. In 'net' we added a dynamic memory allocation to nl80211_dump_wiphy() to fix a race that Linus reported. Meanwhile in 'net-next' the handlers were converted to use pre and post doit handlers which use a flag to determine whether to hold the RTNL mutex around the operation. However, the dump handlers to not use this logic. Instead they have to explicitly do the locking. There were apparent bugs in the conversion of nl80211_dump_wiphy() in that we were not dropping the RTNL mutex in all the return paths, and it seems we very much should be doing so. So I fixed that whilst handling the overlapping changes. To simplify the initial returns, I take the RTNL mutex after we try to allocate 'tb'. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-13xen-netback: don't de-reference vif pointer after having called xenvif_put()Jan Beulich
When putting vif-s on the rx notify list, calling xenvif_put() must be deferred until after the removal from the list and the issuing of the notification, as both operations dereference the pointer. Changing this got me to notice that the "irq" variable was effectively unused (and was of too narrow type anyway). Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-23xen-netback: split event channels support for Xen backend driverWei Liu
Netback and netfront only use one event channel to do TX / RX notification, which may cause unnecessary wake-up of processing routines. This patch adds a new feature called feature-split-event-channels to netback, enabling it to handle TX and RX events separately. Netback will use tx_irq to notify guest for TX completion, rx_irq for RX notification. If frontend doesn't support this feature, tx_irq equals to rx_irq. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-17xen-netback: enable user to unload netback moduleWei Liu
This patch enables user to unload netback module, which is useful when user wants to upgrade to a newer netback module without rebooting the host. Netfront cannot handle netback removal event. As we cannot fix all possible frontends we add module get / put along with vif get / put to avoid mis-unloading of netback. To unload netback module, user needs to shutdown all VMs or migrate them to another host or unplug all vifs before hand. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com>¬ Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-17xen-netback: remove dead codeWei Liu
The array mmap_pages is never touched in the initialization function. This is remnant of mapping mechanism, which does not exist upstream. In current upstream code this array only tracks usage of pages inside netback. Those pages are allocated when contructing a SKB and passed directly to network subsystem. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-02xen-netback: better names for thresholdsWei Liu
This patch only changes some names to avoid confusion. In this patch we have: MAX_SKB_SLOTS_DEFAULT -> FATAL_SKB_SLOTS_DEFAULT max_skb_slots -> fatal_skb_slots #define XEN_NETBK_LEGACY_SLOTS_MAX XEN_NETIF_NR_SLOTS_MIN The fatal_skb_slots is the threshold to determine whether a packet is malicious. XEN_NETBK_LEGACY_SLOTS_MAX is the maximum slots a valid packet can have at this point. It is defined to be XEN_NETIF_NR_SLOTS_MIN because that's guaranteed to be supported by all backends. Suggested-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-02xen-netback: avoid allocating variable size array on stackWei Liu
Tune xen_netbk_count_requests to not touch working array beyond limit, so that we can make working array size constant. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-02xen-netback: remove redundent parameter in netbk_count_requestsWei Liu
Tracking down from the caller, first_idx is always equal to vif->tx.req_cons. Remove it to avoid confusion. Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-22xen-netback: don't disconnect frontend when seeing oversize packetWei Liu
Some frontend drivers are sending packets > 64 KiB in length. This length overflows the length field in the first slot making the following slots have an invalid length. Turn this error back into a non-fatal error by dropping the packet. To avoid having the following slots having fatal errors, consume all slots in the packet. This does not reopen the security hole in XSA-39 as if the packet as an invalid number of slots it will still hit fatal error case. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-22xen-netback: coalesce slots in TX path and fix regressionsWei Liu
This patch tries to coalesce tx requests when constructing grant copy structures. It enables netback to deal with situation when frontend's MAX_SKB_FRAGS is larger than backend's MAX_SKB_FRAGS. With the help of coalescing, this patch tries to address two regressions avoid reopening the security hole in XSA-39. Regression 1. The reduction of the number of supported ring entries (slots) per packet (from 18 to 17). This regression has been around for some time but remains unnoticed until XSA-39 security fix. This is fixed by coalescing slots. Regression 2. The XSA-39 security fix turning "too many frags" errors from just dropping the packet to a fatal error and disabling the VIF. This is fixed by coalescing slots (handling 18 slots when backend's MAX_SKB_FRAGS is 17) which rules out false positive (using 18 slots is legit) and dropping packets using 19 to `max_skb_slots` slots. To avoid reopening security hole in XSA-39, frontend sending packet using more than max_skb_slots is considered malicious. The behavior of netback for packet is thus: 1-18 slots: valid 19-max_skb_slots slots: drop and respond with an error max_skb_slots+ slots: fatal error max_skb_slots is configurable by admin, default value is 20. Also change variable name from "frags" to "slots" in netbk_count_requests. Please note that RX path still has dependency on MAX_SKB_FRAGS. This will be fixed with separate patch. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-12xen-netback: switch to use skb_partial_csum_set()Jason Wang
Switch to use skb_partial_csum_set() to simplify the codes. Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-10xen-netback: fix sparse warningstephen hemminger
Fix warning about 0 used as NULL. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-27net: switch to use skb_probe_transport_header()Jason Wang
Switch to use the new help skb_probe_transport_header() to do the l4 header probing for untrusted sources. For packets with partial csum, the header should already been set by skb_partial_csum_set(). Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-26netback: set transport header before passing it to kernelJason Wang
Currently, for the packets receives from netback, before doing header check, kernel just reset the transport header in netif_receive_skb() which pretends non l4 header. This is suboptimal for precise packet length estimation (introduced in 1def9238: net_sched: more precise pkt_len computation) which needs correct l4 header for gso packets. The patch just reuse the header probed by netback for partial checksum packets and tries to use skb_flow_dissect() for other cases, if both fail, just pretend no l4 header. Cc: Eric Dumazet <edumazet@google.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-25xen-netback: remove skb in xen_netbk_alloc_pageWei Liu
This variable is never used. Signed-off-by: Wei Liu <wei.liu2@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-19Revert "xen: netback: remove redundant xenvif_put"David S. Miller
This reverts commit d37204566a61d5116d385ae909db8e14a734b30f. This change is incorrect, as per Jan Beulich: ==================== But this is wrong from all we can tell, we discussed this before (Wei pointed to the discussion in an earlier reply). The core of it is that the put here parallels the one in netbk_tx_err(), and the one in xenvif_carrier_off() matches the get from xenvif_connect() (which normally would be done on the path coming through xenvif_disconnect()). ==================== And a previous discussion of this issue is at: http://marc.info/?l=xen-devel&m=136084174026977&w=2 Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-19xen: netback: remove redundant xenvif_putAndrew Jones
netbk_fatal_tx_err() calls xenvif_carrier_off(), which does a xenvif_put(). As callers of netbk_fatal_tx_err should only have one reference to the vif at this time, then the xenvif_put in netbk_fatal_tx_err is one too many. Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net into netDavid S. Miller
Pull in 'net' to take in the bug fixes that didn't make it into 3.8-final. Also, deal with the semantic conflict of the change made to net/ipv6/xfrm6_policy.c A missing rt6->n neighbour release was added to 'net', but in 'net-next' we no longer cache the neighbour entries in the ipv6 routes so that change is not appropriate there. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-14xen-netback: cancel the credit timer when taking the vif downDavid Vrabel
If the credit timer is left armed after calling xen_netbk_remove_xenvif(), then it may fire and attempt to schedule the vif which will then oops as vif->netbk == NULL. This may happen both in the fatal error path and during normal disconnection from the front end. The sequencing during shutdown is critical to ensure that: a) vif->netbk doesn't become unexpectedly NULL; and b) the net device/vif is not freed. 1. Mark as unschedulable (netif_carrier_off()). 2. Synchronously cancel the timer. 3. Remove the vif from the schedule list. 4. Remove it from it netback thread group. 5. Wait for vif->refcnt to become 0. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> Reported-by: Christopher S. Aker <caker@theshore.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-14xen-netback: correctly return errors from netbk_count_requests()David Vrabel
netbk_count_requests() could detect an error, call netbk_fatal_tx_error() but return 0. The vif may then be used afterwards (e.g., in a call to netbk_tx_error(). Since netbk_fatal_tx_error() could set vif->refcnt to 1, the vif may be freed immediately after the call to netbk_fatal_tx_error() (e.g., if the vif is also removed). Netback thread Xenwatch thread ------------------------------------------- netbk_fatal_tx_err() netback_remove() xenvif_disconnect() ... free_netdev() netbk_tx_err() Oops! Signed-off-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: Jan Beulich <JBeulich@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reported-by: Christopher S. Aker <caker@theshore.net> Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Synchronize with 'net' in order to sort out some l2tp, wireless, and ipv6 GRE fixes that will be built on top of in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-07netback: correct netbk_tx_err to handle wrap around.Ian Campbell
Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Jan Beulich <JBeulich@suse.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-07xen/netback: free already allocated memory on failure in xen_netbk_get_requestsIan Campbell
Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>