Rename I2C_FUNC_SMBUS_HWPEC_CALC as I2C_FUNC_SMBUS_PEC, and list that
functionality as always available through the software implementation.
Update documentation accordingly (and list similar requirements).
The way it's currently packaged doesn't present the capability in a
useful way.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Add support for multiple chips to i2c-stub. I've changed the memory
allocation scheme from static to dynamic, so that we don't waste too
much memory.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Mark M. Hoffman <mhoffman@lightlink.com>
Do not initialize the PCF8574 with an arbitrary value. Users will have
to write the initial value to sysfs themselves.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Fix docbook templates for new x86 path/filenames:
docproc: linux-2.6.23-git2/include/asm-i386/mca_dma.h: No such file or directory
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix docbook templates for new x86 path/filenames.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix docbook templates for modified x86 path/filenames.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix docbook templates for new x86 path/filenames:
docproc: linux-2.6.23-git2/include/asm-i386/io.h: No such file or directory
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev: (119 commits)
[libata] struct pci_dev related cleanups
libata: use ata_exec_internal() for PMP register access
libata: implement ATA_PFLAG_RESETTING
libata: add @timeout to ata_exec_internal[_sg]()
ahci: fix notification handling
ahci: clean up PORT_IRQ_BAD_PMP enabling
ahci: kill leftover from enabling NCQ over PMP
libata: wrap schedule_timeout_uninterruptible() in loop
libata: skip suppress reporting if ATA_EHI_QUIET
libata: clear ehi description after initial host report
pata_jmicron: match vendor and class code only
libata: add ST9160821AS / 3.ALD to NCQ blacklist
pata_acpi: ACPI driver support
libata-core: Expose gtm methods for driver use
libata: add HDT722516DLA380 to NCQ blacklist
libata: blacklist NCQ on Seagate Barracuda ST380817AS
[libata] Turn on ACPI by default
libata_scsi: Fix ATAPI transfer lengths
libata: correct handling of SRST reset sequences
libata: Integrate ACPI-based PATA/SATA hotplug - version 5
...
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6: (37 commits)
PCI: merge almost all of pci_32.h and pci_64.h together
PCI: X86: Introduce and enable PCI domain support
PCI: Add 'nodomains' boot option, and pci_domains_supported global
PCI: modify PCI bridge control ISA flag for clarity
PCI: use _CRS for PCI resource allocation
PCI: avoid P2P prefetch window for expansion ROMs
PCI: skip ISA ioresource alignment on some systems
PCI: remove transparent bridge sizing
pci: write file size to inode on proc bus file write
pci: use size stored in proc_dir_entry for proc bus files
pci: implement "pci=noaer"
PCI: fix IDE legacy mode resources
MSI: Use correct data offset for 32-bit MSI in read_msi_msg()
PCI: Fix incorrect argument order to list_add_tail() in PCI dynamic ID code
PCI: i386: Compaq EVO N800c needs PCI bus renumbering
PCI: Remove no longer correct documentation regarding MSI vector assignment
PCI: re-enable onboard sound on "MSI K8T Neo2-FIR"
PCI: quirk_vt82c586_acpi: Omit reading PCI revision ID
PCI: quirk amd_8131_mmrbc: Omit reading pci revision ID
cpqphp: Use PCI_CLASS_REVISION instead of PCI_REVISION_ID for read
...
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6: (75 commits)
PM: merge device power-management source files
sysfs: add copyrights
kobject: update the copyrights
kset: add some kerneldoc to help describe what these strange things are
Driver core: rename ktype_edd and ktype_efivar
Driver core: rename ktype_driver
Driver core: rename ktype_device
Driver core: rename ktype_class
driver core: remove subsystem_init()
sysfs: move sysfs file poll implementation to sysfs_open_dirent
sysfs: implement sysfs_open_dirent
sysfs: move sysfs_dirent->s_children into sysfs_dirent->s_dir
sysfs: make sysfs_root a regular directory dirent
sysfs: open code sysfs_attach_dentry()
sysfs: make s_elem an anonymous union
sysfs: make bin attr open get active reference of parent too
sysfs: kill unnecessary NULL pointer check in sysfs_release()
sysfs: kill unnecessary sysfs_get() in open paths
sysfs: reposition sysfs_dirent->s_mode.
sysfs: kill sysfs_update_file()
...
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/usb-2.6: (142 commits)
USB: fix race in autosuspend reschedule
atmel_usba_udc: Keep track of the device status
USB: Nikon D40X unusual_devs entry
USB: serial core should respect driver requirements
USB: documentation for USB power management
USB: skip autosuspended devices during system resume
USB: mutual exclusion for EHCI init and port resets
USB: allow usbstorage to have LUNS greater than 2Tb
USB: Adding support for SHARP WS011SH to ipaq.c
USB: add atmel_usba_udc driver
USB: ohci SSB bus glue
USB: ehci build fixes on au1xxx, ppc-soc
USB: add runtime frame_no quirk for big-endian OHCI
USB: funsoft: Fix termios
USB: visor: termios bits
USB: unusual_devs entry for Nikon DSC D2Xs
USB: re-remove <linux/usb_sl811.h>
USB: move <linux/usb_gadget.h> to <linux/usb/gadget.h>
USB: Export URB statistics for powertop
USB: serial gadget: Disable endpoints on unload
...
* Introduce pci_domains_supported global, hardcoded to zero if
!CONFIG_PCI_DOMAINS.
* Introduce 'nodomains' boot option, which clears pci_domains_supported
on platforms that enable it by default (x86, x86-64, and others when
they are converted to use this).
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use _CRS for PCI resource allocation
This patch resolves an issue where incorrect PCI memory and i/o ranges
are being assigned to hotplugged PCI devices on some IBM systems. The
resource mis-allocation not only makes the PCI device unuseable but
often makes the entire system unuseable due to resulting machine checks.
The hotplug capable PCI slots on the affected systems are not located
under a standard P2P bridge but are instead located under PCI root
bridges or subtractive decode P2P bridges. For example, the IBM x3850
contains 2 hotplug capable PCI-X slots and 4 hotplug capable PCIe slots
with the PCI-X slots each located under a PCI root bridge and the PCIe
slots each located under a subtractive decode P2P bridge.
The current i386/x86_64 PCI resource allocation code does not use _CRS
returned resource information. No other resource information source is
available for slots that are not below a standard P2P bridge so
incorrect ranges are being allocated from e820 hole causing the bad
result.
This patch causes the kernel to use _CRS returned resource info. It is
roughly based on a change provided by Matthew Wilcox for the ia64 kernel
in 2005. Due to possible buggy BIOS factor and possible yet to be
discovered kernel issues the function is disabled by default and can be
enabled with pci=use_crs.
Signed-off-by: Gary Hade <gary.hade@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
For cases in which CONFIG_PCIEAER=y (such as distro kernels), allow users
to disable PCIE Advanced Error Reporting by using "pci=noaer" on the
kernel command line.
This can be used to work around hardware or (kernel) software problems.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The MSI vector reservation system described in Documentation/MSI-HOWTO.txt
was removed by Eric in 92db6d10bc. Remove
the references to it in the documentation.
While we're here § 5.5.1 refers to x86 hardware requirements, so make that
clear.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On at least ARM (and I'm told MIPS too) dma_free_coherent() has a newish
call context requirement: unlike its dma_alloc_coherent() sibling, it may
not be called with IRQs disabled. (This was new behavior on ARM as of late
2005, caused by ARM SMP updates.) This little surprise can be annoyingly
driver-visible.
Since it looks like that restriction won't be removed, this patch changes
the definition of the API to include that requirement. Also, to help catch
nonportable drivers, it updates the x86 and swiotlb versions to include the
relevant warnings. (I already observed that it trips on the
bus_reset_tasklet of the new firewire_ohci driver.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Miller <davem@davemloft.net>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as998) adds documentation on how USB power management
works and how to use it.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch implements a USB serial port driver for the Winchiphead
CH341 USB-RS232 Converter. This chip also implements an IEEE 1284
parallel port, I2C and SPI, but that is not supported by the driver.
Signed-off-by: Frank A Kingswood <frank@kingswood-consulting.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Update usbmon documentation, mentioning the "zero" (wildcard) bus.
Possibly, in my first hunk, the 'either ... or ...' should be rephrased a bit to
be expressed better.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Here is another sync patch of Documentation/ja_JP/HOWTO
Japanese developer sent me some cosmetic changes and also follow
changes of HOWTO
Cross reference URL (sosdg.org/qiyong/lxr)
known_regression explanations on kernel dev. process
Signed-off-by: Tsugikazu Shibata <tshibata@ab.jp.nec.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add support for an MFGPT clock event device; this allows us to use MFGPTs as
the basis for high-resolution timers.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This adds support for Multi-Function General Purpose Timers. It detects the
available timers during southbridge init, and provides an API for allocating
and setting the timers. They're higher resolution than the standard PIT, so
the MFGPTs come in handy for quite a few things.
Note that we never clobber the timers that the BIOS might have opted to use;
we just check for unused timers.
Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Andres Salomon <dilinger@debian.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Big thanks go to Mathias Kolehmainen for reporting the bug, providing
debug output and testing the patches I sent him to get it working.
The fix was to stop calling ntfs_attr_set() at mount time as that causes
balance_dirty_pages_ratelimited() to be called which on systems with
little memory actually tries to go and balance the dirty pages which tries
to take the s_umount semaphore but because we are still in fill_super()
across which the VFS holds s_umount for writing this results in a
deadlock.
We now do the dirty work by hand by submitting individual buffers. This
has the annoying "feature" that mounting can take a few seconds if the
journal is large as we have clear it all. One day someone should improve
on this by deferring the journal clearing to a helper kernel thread so it
can be done in the background but I don't have time for this at the moment
and the current solution works fine so I am leaving it like this for now.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
s390-drivers is generated using the docbook comments. It should
eventually supersede Documentation/s390/cds.txt.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (408 commits)
[POWERPC] Add memchr() to the bootwrapper
[POWERPC] Implement logging of unhandled signals
[POWERPC] Add legacy serial support for OPB with flattened device tree
[POWERPC] Use 1TB segments
[POWERPC] XilinxFB: Allow fixed framebuffer base address
[POWERPC] XilinxFB: Add support for custom screen resolution
[POWERPC] XilinxFB: Use pdata to pass around framebuffer parameters
[POWERPC] PCI: Add 64-bit physical address support to setup_indirect_pci
[POWERPC] 4xx: Kilauea defconfig file
[POWERPC] 4xx: Kilauea DTS
[POWERPC] 4xx: Add AMCC Kilauea eval board support to platforms/40x
[POWERPC] 4xx: Add AMCC 405EX support to cputable.c
[POWERPC] Adjust TASK_SIZE on ppc32 systems to 3GB that are capable
[POWERPC] Use PAGE_OFFSET to tell if an address is user/kernel in SW TLB handlers
[POWERPC] 85xx: Enable FP emulation in MPC8560 ADS defconfig
[POWERPC] 85xx: Killed <asm/mpc85xx.h>
[POWERPC] 85xx: Add cpm nodes for 8541/8555 CDS
[POWERPC] 85xx: Convert mpc8560ads to the new CPM binding.
[POWERPC] mpc8272ads: Remove muram from the CPM reg property.
[POWERPC] Make clockevents work on PPC601 processors
...
Fixed up conflict in Documentation/powerpc/booting-without-of.txt manually.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband: (87 commits)
mlx4_core: Fix section mismatches
IPoIB: Allow setting policy to ignore multicast groups
IB/mthca: Mark error paths as unlikely() in post_srq_recv functions
IB/ipath: Minor fix to ordering of freeing and zeroing of tid pages.
IB/ipath: Remove redundant link state checks
IB/ipath: Fix IB_EVENT_PORT_ERR event
IB/ipath: Better handling of unexpected GPIO interrupts
IB/ipath: Maintain active time on all chips
IB/ipath: Fix QHT7040 serial number check
IB/ipath: Indicate a couple of chip bugs to userspace
IB/ipath: iba6110 rev4 no longer needs recv header overrun workaround
IB/ipath: Use counters in ipath_poll and cleanup interrupts in ipath_close
IB/ipath: Remove duplicate copy of LMC
IB/ipath: Add ability to set the LMC via the sysfs debugging interface
IB/ipath: Optimize completion queue entry insertion and polling
IB/ipath: Implement IB_EVENT_QP_LAST_WQE_REACHED
IB/ipath: Generate flush CQE when QP is in error state
IB/ipath: Remove redundant code
IB/ipath: Future proof eeprom checksum code (contents reading)
IB/ipath: UC RDMA WRITE with IMMEDIATE doesn't send the immediate
...
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (867 commits)
[SKY2]: status polling loop (post merge)
[NET]: Fix NAPI completion handling in some drivers.
[TCP]: Limit processing lost_retrans loop to work-to-do cases
[TCP]: Fix lost_retrans loop vs fastpath problems
[TCP]: No need to re-count fackets_out/sacked_out at RTO
[TCP]: Extract tcp_match_queue_to_sack from sacktag code
[TCP]: Kill almost unused variable pcount from sacktag
[TCP]: Fix mark_head_lost to ignore R-bit when trying to mark L
[TCP]: Add bytes_acked (ABC) clearing to FRTO too
[IPv6]: Update setsockopt(IPV6_MULTICAST_IF) to support RFC 3493, try2
[NETFILTER]: x_tables: add missing ip6t_modulename aliases
[NETFILTER]: nf_conntrack_tcp: fix connection reopening
[QETH]: fix qeth_main.c
[NETLINK]: fib_frontend build fixes
[IPv6]: Export userland ND options through netlink (RDNSS support)
[9P]: build fix with !CONFIG_SYSCTL
[NET]: Fix dev_put() and dev_hold() comments
[NET]: make netlink user -> kernel interface synchronious
[NET]: unify netlink kernel socket recognition
[NET]: cleanup 3rd argument in netlink_sendskb
...
Fix up conflicts manually in Documentation/feature-removal-schedule.txt
and my new least favourite crap, the "mod_devicetable" support in the
files include/linux/mod_devicetable.h and scripts/mod/file2alias.c.
(The latter files seem to be explicitly _designed_ to get conflicts when
different subsystems work with them - that have an absolutely horrid
lack of subsystem separation!)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'block-2.6.24' of git://git.kernel.dk/data/git/linux-2.6-block: (37 commits)
[BLOCK] Fix failing compile with BLK_DEV_IO_TRACE=n
compat_ioctl: move floppy handlers to block/compat_ioctl.c
compat_ioctl: move cdrom handlers to block/compat_ioctl.c
compat_ioctl: move BLKPG handling to block/compat_ioctl.c
compat_ioctl: move hdio calls to block/compat_ioctl.c
compat_ioctl: handle blk_trace ioctls
compat_ioctl: add compat_blkdev_driver_ioctl()
compat_ioctl: move common block ioctls to compat_blkdev_ioctl
Sysace: Don't enable IRQ until after interrupt handler is registered
Sysace: sparse fixes
Sysace: Minor coding convention fixup
drivers/block/umem: use DRIVER_NAME where appropriate
drivers/block/umem: trim trailing whitespace
drivers/block/umem: minor cleanups
drivers/block/umem: use dev_printk()
drivers/block/umem: move private include away from include/linux
Sysace: Labels in C code should not be indented.
Sysace: Add of_platform_bus binding
Sysace: Move IRQ handler registration to occur after FSM is initialized
Sysace: minor rework and cleanup changes
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6: (74 commits)
Blackfin serial driver: pending a unique anomaly id, tie the break flood issue to ANOMALY_05000230
blackfin enable arbitary speed serial setting
Blackfin arch: Remove cruft - CONFIG_DEBUG_SERIAL_EARLY_INIT and DEBUG_KERNEL_START
Blackfin arch: fix typo in register name
Blackfin arch: trim the Blackfin arch MAINTAINERS list
Blackfin arch: fix bug libstdc++ calling writev with an iovec containing { NULL, 0 } fails on Blackfin
Blackfin arch: Export strcpy - occasionally get module link failures otherwise
Blackfin arch: the load address is not safe to point to as a workaround for ANOMALY 05000281
Blackfin arch: show_mem can not be marked as init, since it is called during OOM condition
Blackfin arch: flush/inv the correct range when using write back cache and fix bugs find by dmacopy
Blackfin arch: update kgdb patch
Blackfin arch: Comply with revised Anomaly Workarounds for BF533 05000311 and BF561 05000323
Blackfin arch: Print out debug info, as early as possible
Blackfin arch: Enable earlyprintk earlier - so any error after our interrupt tables are set up will print out
Blackfin arch: fix endless loop bug when a double fault happens
Blackfin arch: Initial patch to add earlyprintk support
Blackfin arch: add TWIx_REGBASE and SPIx_REGBASE to specific CPU header files, use the new REGBASE for board platform resources
Blackfin arch: modify the insX/outsX and dma_insX/dma_outsX to be compatible with other archs
Blackfin arch: add more common defines for output sections
Blackfin arch: cleanup IO and DMA_IO API function definitions according to other arches
...
The i386/x86_64 merge provides a symlink to the old bzImage
location. This is just a transitional migration helper.
Remove it after a 6 month grace period.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Move the headers to include/asm-x86 and fixup the
header install make rules
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This corrects erroneous documentation of the socket API.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds documentation on the use of service codes on client and
server.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This enables applications to query the current value of the Maximum
Packet Size via a socket option, suggested as a SHOULD in (RFC 4340,
p. 102).
This socket option is useful to avoid the annoying bail-out via
`-EMSGSIZE'. In particular, as fragmentation is not currently
supported (and its use is partly discouraged in RFC 4340).
With this option, it is possible to size buffers accordingly, e.g.
int buflen = dccp_get_cur_mps(sockfd);
/* or */
if (msgsize > dccp_get_cur_mps(sockfd))
die("message is too large for this path");
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This improves radiotap injection by removing the shortcut over TX handlers
that led to BUGS when injecting frames without setting a rate and also
resulted in various other quirks. Now, TX handlers are run but some
information that was present in the radiotap header is used instead of
automatic settings.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Andy Green <andy@warmcat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Stop building and configuring driver for Digi RightSwitch, which was
never actually sold to anyone, and remove it from MAINTAINERS.
In response to an investigation into the firmware of the "Digi Rightswitch"
driver, Andres Salomon discovered:
>
> Dear Andres:
>
> After further research, we found that this product was killed in place
> and never reached the market. We would like to request that this not be
> included.
Since the product never reached market, clearly nobody is using this orphaned
driver.
Signed-off-by: Nathanael Nerode <neroden@gcc.gnu.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This implements a SHOULD from RFC 4340, 7.5.4:
"To protect against denial-of-service attacks, DCCP implementations SHOULD
impose a rate limit on DCCP-Syncs sent in response to sequence-invalid packets,
such as not more than eight DCCP-Syncs per second."
The rate-limit is maintained on a per-socket basis. This is a more stringent
policy than enforcing the rate-limit on a per-source-address basis and
protects against attacks with forged source addresses.
Moreover, the mechanism is deliberately kept simple. In contrast to
xrlim_allow(), bursts of Sync packets in reply to sequence-invalid packets
are not supported. This foils such attacks where the receipt of a Sync
triggers further sequence-invalid packets. (I have tested this mechanism against
xrlim_allow algorithm for Syncs, permitting bursts just increases the problems.)
In order to keep flexibility, the timeout parameter can be set via sysctl; and
the whole mechanism can even be disabled (which is however not recommended).
The algorithm in this patch has been improved with regard to wrapping issues
thanks to a suggestion by Arnaldo.
Commiter note: Rate limited the step 6 DCCP_WARN too, as it says we're
sending a sync.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
David Brownell