BMC/Intel-BMC/linux.git/net/ipv6/ip6_flowlabel.c, branch dev

ipv6: Flow label state ranges

2015-05-04T01:58:01+00:00

This patch divides the IPv6 flow label space into two ranges: 0-7ffff is reserved for flow label manager, 80000-fffff will be used for creating auto flow labels (per RFC6438). This only affects how labels are set on transmit, it does not affect receive. This range split can be disbaled by systcl. Background: IPv6 flow labels have been an unmitigated disappointment thus far in the lifetime of IPv6. Support in HW devices to use them for ECMP is lacking, and OSes don't turn them on by default. If we had these we could get much better hashing in IPv6 networks without resorting to DPI, possibly eliminating some of the motivations to to define new encaps in UDP just for getting ECMP. Unfortunately, the initial specfications of IPv6 did not clarify how they are to be used. There has always been a vague concept that these can be used for ECMP, flow hashing, etc. and we do now have a good standard how to this in RFC6438. The problem is that flow labels can be either stateful or stateless (as in RFC6438), and we are presented with the possibility that a stateless label may collide with a stateful one. Attempts to split the flow label space were rejected in IETF. When we added support in Linux for RFC6438, we could not turn on flow labels by default due to this conflict. This patch splits the flow label space and should give us a path to enabling auto flow labels by default for all IPv6 packets. This is an API change so we need to consider compatibility with existing deployment. The stateful range is chosen to be the lower values in hopes that most uses would have chosen small numbers. Once we resolve the stateless/stateful issue, we can proceed to look at enabling RFC6438 flow labels by default (starting with scaled testing). Signed-off-by: Tom Herbert Signed-off-by: David S. Miller

ipv6: coding style: comparison for inequality with NULL

2015-03-31T17:51:54+00:00

The ipv6 code uses a mixture of coding styles. In some instances check for NULL pointer is done as x != NULL and sometimes as x. x is preferred according to checkpatch and this patch makes the code consistent by adopting the latter form. No changes detected by objdiff. Signed-off-by: Ian Morris Signed-off-by: David S. Miller

ipv6: coding style: comparison for equality with NULL

2015-03-31T17:51:54+00:00

The ipv6 code uses a mixture of coding styles. In some instances check for NULL pointer is done as x == NULL and sometimes as !x. !x is preferred according to checkpatch and this patch makes the code consistent by adopting the latter form. No changes detected by objdiff. Signed-off-by: Ian Morris Signed-off-by: David S. Miller

net: Kill hold_net release_net

2015-03-12T18:39:40+00:00

hold_net and release_net were an idea that turned out to be useless. The code has been disabled since 2008. Kill the code it is long past due. Signed-off-by: "Eric W. Biederman" Acked-by: Eric Dumazet Signed-off-by: David S. Miller

ipv6: fix possible deadlock in ip6_fl_purge / ip6_fl_gc

2015-02-12T15:13:03+00:00

Use spin_lock_bh in ip6_fl_purge() to prevent following potentially deadlock scenario between ip6_fl_purge() and ip6_fl_gc() timer. ================================= [ INFO: inconsistent lock state ] 3.19.0 #1 Not tainted --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/5/0 [HC0[0]:SC1[1]:HE1:SE0] takes: (ip6_fl_lock){+.?...}, at: [] ip6_fl_gc+0x2d/0x180 {SOFTIRQ-ON-W} state was registered at: [] __lock_acquire+0x4a0/0x10b0 [] lock_acquire+0xc4/0x2b0 [] _raw_spin_lock+0x3d/0x80 [] ip6_flowlabel_net_exit+0x28/0x110 [] ops_exit_list.isra.1+0x39/0x60 [] cleanup_net+0x100/0x1e0 [] process_one_work+0x20a/0x830 [] worker_thread+0x11b/0x460 [] kthread+0x104/0x120 [] ret_from_fork+0x7c/0xb0 irq event stamp: 84640 hardirqs last enabled at (84640): [] _raw_spin_unlock_irq+0x30/0x50 hardirqs last disabled at (84639): [] _raw_spin_lock_irq+0x1f/0x80 softirqs last enabled at (84628): [] _local_bh_enable+0x21/0x50 softirqs last disabled at (84629): [] irq_exit+0x12d/0x150 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(ip6_fl_lock); lock(ip6_fl_lock); *** DEADLOCK *** Signed-off-by: Jan Stancek Signed-off-by: David S. Miller

ipv6: coding style improvements (remove assignment in if statements)

2014-11-24T02:00:56+00:00

This change has no functional impact and simply addresses some coding style issues detected by checkpatch. Specifically this change adjusts "if" statements which also include the assignment of a variable. No changes to the resultant object files result as determined by objdiff. Signed-off-by: Ian Morris Signed-off-by: David S. Miller

net: Convert SEQ_START_TOKEN/seq_printf to seq_puts

2014-11-06T03:04:55+00:00

Using a single fixed string is smaller code size than using a format and many string arguments. Reduces overall code size a little. $ size net/ipv4/igmp.o* net/ipv6/mcast.o* net/ipv6/ip6_flowlabel.o* text data bss dec hex filename 34269 7012 14824 56105 db29 net/ipv4/igmp.o.new 34315 7012 14824 56151 db57 net/ipv4/igmp.o.old 30078 7869 13200 51147 c7cb net/ipv6/mcast.o.new 30105 7869 13200 51174 c7e6 net/ipv6/mcast.o.old 11434 3748 8580 23762 5cd2 net/ipv6/ip6_flowlabel.o.new 11491 3748 8580 23819 5d0b net/ipv6/ip6_flowlabel.o.old Signed-off-by: Joe Perches Signed-off-by: David S. Miller

ipv6: trivial, add bracket for the if block

2014-11-04T22:10:19+00:00

The "else" block is on several lines and use bracket. Signed-off-by: Florent Fourcot Signed-off-by: David S. Miller

ipv6: White-space cleansing : gaps between function and symbol export

2014-08-25T05:37:52+00:00

This patch makes no changes to the logic of the code but simply addresses coding style issues as detected by checkpatch. Both objdump and diff -w show no differences. This patch removes some blank lines between the end of a function definition and the EXPORT_SYMBOL_GPL macro in order to prevent checkpatch warning that EXPORT_SYMBOL must immediately follow a function. Signed-off-by: Ian Morris Signed-off-by: David S. Miller

ipv6: White-space cleansing : Line Layouts

2014-08-25T05:37:52+00:00

This patch makes no changes to the logic of the code but simply addresses coding style issues as detected by checkpatch. Both objdump and diff -w show no differences. A number of items are addressed in this patch: * Multiple spaces converted to tabs * Spaces before tabs removed. * Spaces in pointer typing cleansed (char *)foo etc. * Remove space after sizeof * Ensure spacing around comparators such as if statements. Signed-off-by: Ian Morris Signed-off-by: David S. Miller