When using tunnel TLVs (at the moment, this means Geneve options), a
controller must first map the class and type onto an appropriate OXM
field so that it can be used in OVS flow operations. This table is
managed using OpenFlow extensions.
The original code that added support for TLVs made the mapping table
global as a simplification. However, this is not really logically
correct as the OpenFlow management commands are operating on a per-bridge
basis. This removes the original limitation to make the table per-bridge.
One nice result of this change is that it is generally clearer whether
the tunnel metadata is in datapath or OpenFlow format. Rather than
allowing ad-hoc format changes and trying to handle both formats in the
tunnel metadata functions, the format is more clearly separated by function.
Datapaths (both kernel and userspace) use datapath format and it is not
changed during the upcall process. At the beginning of action translation,
tunnel metadata is converted to OpenFlow format and flows and wildcards
are translated back at the end of the process.
As an additional benefit, this change improves performance in some flow
setup situations by keeping the tunnel metadata in the original packet
format in more cases. This helps when copies need to be made as the amount
of data touched is only what is present in the packet rather than the
maximum amount of metadata supported.
Co-authored-by: Madhu Challa <challa@noironetworks.com>
Signed-off-by: Madhu Challa <challa@noironetworks.com>
Signed-off-by: Jesse Gross <jesse@kernel.org>
Acked-by: Ben Pfaff <blp@ovn.org>
Some tunnel flags are purely internal implementation details (primarily
FLOW_TNL_F_UDPIF). These shouldn't be output when we format tunnel
flows, so this masks them out.
Signed-off-by: Jesse Gross <jesse@kernel.org>
Acked-by: Ben Pfaff <blp@ovn.org>
With eight 32-bit registers, we can only store two IPv6 addresses, which is
pretty tight.
Signed-off-by: Justin Pettit <jpettit@ovn.org>
Acked-by: Ben Pfaff <blp@ovn.org>
Commit f2d105b5 (ofproto-dpif-xlate: xlate ct_{mark, label} correctly.)
introduced the ovs_u128_and() function. It directly takes ovs_u128
values as arguments instead of pointers to them. As this is a bit more
direct way to deal with 128-bit values, modify the other utility
functions to do the same.
Signed-off-by: Justin Pettit <jpettit@ovn.org>
Acked-by: Joe Stringer <joe@ovn.org>
This commit also adds several #include directives in source files in
order to make the 'ofp-util.h' move possible
Signed-off-by: Ben Warren <ben@skyportsystems.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>
Add color output for flow match conditions for ovs-ofctl dump-flows
command utility, by inserting color markers in the functions responsible
for printing those match condictions.
Signed-off-by: Quentin Monnet <quentin.monnet@6wind.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>
Occasionally we get asked about this and I don't see a reason not to
support it.
Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Justin Pettit <jpettit@ovn.org>
Note that because there's been no prerequisite on the outer protocol,
we cannot add it now. Instead, treat the ipv4 and ipv6 dst fields in the way
that either both are null, or at most one of them is non-null.
[cascardo: abstract testing either dst with flow_tnl_dst_is_set]
cascardo: using IPv4-mapped address is an exercise for the future, since this
would require special handling of MFF_TUN_SRC and MFF_TUN_DST and OpenFlow
messages.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
Co-authored-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>
Instead of taking the source and destination as arguments, make these
functions act like their short and long counterparts.
Signed-off-by: Justin Pettit <jpettit@ovn.org>
Acked-by: Ben Pfaff <blp@ovn.org>
This patch adds a new 128-bit metadata field to the connection tracking
interface. When a label is specified as part of the ct action and the
connection is committed, the value is saved with the current connection.
Subsequent ct lookups with the table specified will expose this metadata
as the "ct_label" field in the flow.
For example, to allow new TCP connections from port 1->2 and only allow
established connections from port 2->1, and to associate a label with
those connections:
table=0,priority=1,action=drop
table=0,arp,action=normal
table=0,in_port=1,tcp,action=ct(commit,exec(set_field:1->ct_label)),2
table=0,in_port=2,ct_state=-trk,tcp,action=ct(table=1)
table=1,in_port=2,ct_state=+trk,ct_label=1,tcp,action=1
Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
This patch adds a new 32-bit metadata field to the connection tracking
interface. When a mark is specified as part of the ct action and the
connection is committed, the value is saved with the current connection.
Subsequent ct lookups with the table specified will expose this metadata
as the "ct_mark" field in the flow.
For example, to allow new TCP connections from port 1->2 and only allow
established connections from port 2->1, and to associate a mark with those
connections:
table=0,priority=1,action=drop
table=0,arp,action=normal
table=0,in_port=1,tcp,action=ct(commit,exec(set_field:1->ct_mark)),2
table=0,in_port=2,ct_state=-trk,tcp,action=ct(table=1)
table=1,in_port=2,ct_state=+trk,ct_mark=1,tcp,action=1
Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
This patch adds a new action and fields to OVS that allow connection
tracking to be performed. This support works in conjunction with the
Linux kernel support merged into the Linux-4.3 development cycle.
Packets have two possible states with respect to connection tracking:
Untracked packets have not previously passed through the connection
tracker, while tracked packets have previously been through the
connection tracker. For OpenFlow pipeline processing, untracked packets
can become tracked, and they will remain tracked until the end of the
pipeline. Tracked packets cannot become untracked.
Connections can be unknown, uncommitted, or committed. Packets which are
untracked have unknown connection state. To know the connection state,
the packet must become tracked. Uncommitted connections have no
connection state stored about them, so it is only possible for the
connection tracker to identify whether they are a new connection or
whether they are invalid. Committed connections have connection state
stored beyond the lifetime of the packet, which allows later packets in
the same connection to be identified as part of the same established
connection, or related to an existing connection - for instance ICMP
error responses.
The new 'ct' action transitions the packet from "untracked" to
"tracked" by sending this flow through the connection tracker.
The following parameters are supported initally:
- "commit": When commit is executed, the connection moves from
uncommitted state to committed state. This signals that information
about the connection should be stored beyond the lifetime of the
packet within the pipeline. This allows future packets in the same
connection to be recognized as part of the same "established" (est)
connection, as well as identifying packets in the reply (rpl)
direction, or packets related to an existing connection (rel).
- "zone=[u16|NXM]": Perform connection tracking in the zone specified.
Each zone is an independent connection tracking context. When the
"commit" parameter is used, the connection will only be committed in
the specified zone, and not in other zones. This is 0 by default.
- "table=NUMBER": Fork pipeline processing in two. The original instance
of the packet will continue processing the current actions list as an
untracked packet. An additional instance of the packet will be sent to
the connection tracker, which will be re-injected into the OpenFlow
pipeline to resume processing in the specified table, with the
ct_state and other ct match fields set. If the table is not specified,
then the packet is submitted to the connection tracker, but the
pipeline does not fork and the ct match fields are not populated. It
is strongly recommended to specify a table later than the current
table to prevent loops.
When the "table" option is used, the packet that continues processing in
the specified table will have the ct_state populated. The ct_state may
have any of the following flags set:
- Tracked (trk): Connection tracking has occurred.
- Reply (rpl): The flow is in the reply direction.
- Invalid (inv): The connection tracker couldn't identify the connection.
- New (new): This is the beginning of a new connection.
- Established (est): This is part of an already existing connection.
- Related (rel): This connection is related to an existing connection.
For more information, consult the ovs-ofctl(8) man pages.
Below is a simple example flow table to allow outbound TCP traffic from
port 1 and drop traffic from port 2 that was not initiated by port 1:
table=0,priority=1,action=drop
table=0,arp,action=normal
table=0,in_port=1,tcp,ct_state=-trk,action=ct(commit,zone=9),2
table=0,in_port=2,tcp,ct_state=-trk,action=ct(zone=9,table=1)
table=1,in_port=2,ct_state=+trk+est,tcp,action=1
table=1,in_port=2,ct_state=+trk+new,tcp,action=drop
Based on original design by Justin Pettit, contributions from Thomas
Graf and Daniele Di Proietto.
Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Define struct eth_addr and use it instead of a uint8_t array for all
ethernet addresses in OVS userspace. The struct is always the right
size, and it can be assigned without an explicit memcpy, which makes
code more readable.
"struct eth_addr" is a good type name for this as many utility
functions are already named accordingly.
struct eth_addr can be accessed as bytes as well as ovs_be16's, which
makes the struct 16-bit aligned. All use seems to be 16-bit aligned,
so some algorithms on the ethernet addresses can be made a bit more
efficient making use of this fact.
As the struct fits into a register (in 64-bit systems) we pass it by
value when possible.
This patch also changes the few uses of Linux specific ETH_ALEN to
OVS's own ETH_ADDR_LEN, and removes the OFP_ETH_ALEN, as it is no
longer needed.
This work stemmed from a desire to make all struct flow members
assignable for unrelated exploration purposes. However, I think this
might be a nice code readability improvement by itself.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Struct miniflow is now sometimes used just as a map. Define a new
struct flowmap for that purpose. The flowmap is defined as an array of
maps, and it is automatically sized according to the size of struct
flow, so it will be easier to maintain in the future.
It would have been tempting to use the existing struct bitmap for this
purpose. The main reason this is not feasible at the moment is that
some flowmap algorithms are simpler when it can be assumed that no
struct flow member requires more bits than can fit to a single map
unit. The tunnel member already requires more than 32 bits, so the map
unit needs to be 64 bits wide.
Performance critical algorithms enumerate the flowmap array units
explicitly, as it is easier for the compiler to optimize, compared to
the normal iterator. Without this optimization a classifier lookup
without wildcard masks would be about 25% slower.
With this more general (and maintainable) algorithm the classifier
lookups are about 5% slower, when the struct flow actually becomes big
enough to require a second map. This negates the performance gained
in the "Pre-compute stage masks" patch earlier in the series.
Requested-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Use two maps in miniflow to allow for expansion of struct flow past
512 bytes. We now have one map for tunnel related fields, and another
for the rest of the packet metadata and actual packet header fields.
This split has the benefit that for non-tunneled packets the overhead
should be minimal.
Some miniflow utilities now exist in two variants, new ones operating
over all the data, and the old ones operating only on a single 64-bit
map at a time. The old ones require doubling of code but should
execute faster, so those are used in the datapath and classifier's
lookup path.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
MSVC does not like zero sized arrays in structs. Hence, remove the
'values' member from struct miniflow and add back the getters
miniflow_values() and miniflow_get_values().
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Several encapsulation formats have the concept of an 'OAM' bit
which typically is used with networking tracing tools to
distinguish test packets from real traffic. OVS already internally
has support for this, however, it doesn't do anything with it
and it also isn't exposed for controllers to use. This enables
support through OpenFlow.
There are several other tunnel flags which are consumed internally
by OVS. It's not clear that it makes sense to use them externally
so this does not expose those flags - although it should be easy
to do so if necessary in the future.
Signed-off-by: Jesse Gross <jesse@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
There are several implementations of functions that parse/format
flags and their binary representation. This factors them out into
common routines. In addition to reducing code, it also makes things
more consistent across different parts of OVS.
Signed-off-by: Jesse Gross <jesse@nicira.com>
Allocate the miniflow and minimask in struct minimatch at once, so
that they are consecutive in memory. This halves the number of
allocations, and allows smaller minimatches to share the same cache
line.
After this a minimatch has one heap allocation for all it's data.
Previously it had either none (when data was small enough to fit in
struct miniflow's inline buffer), or two (when the inline buffer was
insufficient). Hopefully always having one performs almost the same
as none or two, in average.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Now that performance critical code already inlines miniflows and
minimasks, we can simplify struct miniflow by always dynamically
allocating miniflows and minimasks to the correct size. This changes
the struct minimatch to always contain pointers to its miniflow and
minimask.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
The current support for Geneve in OVS is exactly equivalent to VXLAN:
it is possible to set and match on the VNI but not on any options
contained in the header. This patch enables the use of options.
The goal for Geneve support is not to add support for any particular option
but to allow end users or controllers to specify what they would like to
match. That is, the full range of Geneve's capabilities should be exposed
without modifying the code (the one exception being options that require
per-packet computation in the fast path).
The main issue with supporting Geneve options is how to integrate the
fields into the existing OpenFlow pipeline. All existing operations
are referred to by their NXM/OXM field name - matches, action generation,
arithmetic operations (i.e. tranfer to a register). However, the Geneve
option space is exactly the same as the OXM space, so a direct mapping
is not feasible. Instead, we create a pool of 64 NXMs that are then
dynamically mapped on Geneve option TLVs using OpenFlow. Once mapped,
these fields become first-class citizens in the OpenFlow pipeline.
An example of how to use Geneve options:
ovs-ofctl add-geneve-map br0 {class=0xffff,type=0,len=4}->tun_metadata0
ovs-ofctl add-flow br0 in_port=LOCAL,actions=set_field:0xffffffff->tun_metadata0,1
This will add a 4 bytes option (filled will all 1's) to all packets
coming from the LOCAL port and then send then out to port 1.
A limitation of this patch is that although the option table is specified
for a particular switch over OpenFlow, it is currently global to all
switches. This will be addressed in a future patch.
Based on work originally done by Madhu Challa. Ben Pfaff also significantly
improved the comments.
Signed-off-by: Madhu Challa <challa@noironetworks.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
The dp_hash match should be printed whenever it is being matched. We
keep the old behavior for flow_format(), which is mostly used to
format PACKET_IN messages. This keeps those messages tidier and avoids
changing a lot of test cases.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Andy Zhou <azhou@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Introduces two new NXMs to represent VXLAN-GBP [0] fields.
actions=load:0x10->NXM_NX_TUN_GBP_ID[],NORMAL
tun_gbp_id=0x10,actions=drop
This enables existing VXLAN tunnels to carry security label
information such as a SELinux context to other network peers.
The values are carried to/from the datapath using the attribute
OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS.
[0] https://tools.ietf.org/html/draft-smith-vxlan-group-policy-00
Signed-off-by: Madhu Challa <challa@noironetworks.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Thomas Graf <tgraf@noironetworks.com>
A "conjunctive match" allows higher-level matches in the flow table, such
as set membership matches, without causing a cross-product explosion for
multidimensional matches. Please refer to the documentation that this
commit adds to ovs-ofctl(8) for a better explanation, including an example.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
So far the compressed flow data in struct miniflow has been in 32-bit
words with a 63-bit map, allowing for a maximum size of struct flow of
252 bytes. With the forthcoming Geneve options this is not sufficient
any more.
This patch solves the problem by changing the miniflow data to 64-bit
words, doubling the flow max size to 504 bytes. Since the word size
is doubled, there is some loss in compression efficiency. To counter
this some of the flow fields have been reordered to keep related
fields together (e.g., the source and destination IP addresses share
the same 64-bit word).
This change should speed up flow data processing on 64-bit CPUs, which
may help counterbalance the impact of making the struct flow bigger in
the future.
Classifier lookup stage boundaries are also changed to 64-bit
alignment, as the current algorithm depends on each miniflow word to
not be split between ranges. This has resulted in new padding (part
of the 'mpls_lse' field).
The 'dp_hash' field is also moved to packet metadata to eliminate
otherwise needed padding there. This allows the L4 to fit into one
64-bit word, and also makes matches on 'dp_hash' more efficient as
misses can be found already on stage 1.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Use MAP_FOR_EACH_INDEX to improve readability when there is no
apparent cost for it.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Slightly simplify match_format() by using ds_chomp()
rather than open-coding its logic.
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
This field allows a flow table to match on the output port currently in the
action set.
ONF-JIRA: EXT-233
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
OpenFlow has priorities in the 16-bit unsigned range, from 0 to 65535.
In the classifier, it is sometimes useful to be able to have values below
and above this range. With the 'unsigned int' type used for priorities
until now, there were no values below the range, so some code worked
around it by converting priorities to 64-bit signed integers. This didn't
seem so great to me given that a plain 'int' also had the needed range.
This commit therefore changes the type used for priorities to int.
The interesting parts of this change are in pvector.h and classifier.c,
where one can see the elimination of the use of int64_t.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
ETH_ADDR_LEN is defined in lib/packets.h, valued 6.
Use this macro instead of magic number 6 to represent the length
of eth mac address.
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
Add function flow_wildcards_init_for_packet() that can be used to set
sensible wildcards when megaflows are disabled. Before this, we set
all the mask bits to ones, which caused printing tunnel, mpls, and/or
transport port fields even for packets for which it makes no sense.
This has the side effect of generating different megaflow masks for
different packet types, so there will be more than one kind of mask in
the datapath classifier. This should not make practical difference,
as megaflows should not be disabled when performance is important.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Use the "+-" syntax more uniformly when printing masked flags, and use
the syntax of delimited 1-flags also for formatting fully masked TCP
flags.
The "+-" syntax only deals with masked flags, but if there are many of
those, the printout becomes long and confusing. Typically there are
many flags only when flags are fully masked, but even then most of
them are zeros, so it makes sense to print the flags that are set
(ones) and omit the zero flags.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
These 64-bit registers are intended to conform with the OpenFlow 1.5
draft specification.
EXT-244.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
This patch addresses two bugs related to ICMPv6(NDP) packets:
- In miniflow_extract() push the words in the correct order
- In parse_icmpv6() use sizeof struct, not size of struct *
match_wc_init() has been modified, to include the nd_target field
when the transport layer protocol is ICMPv6
A testcase has been added to detect the bugs.
Signed-off-by: Daniele Di Proietto <ddiproietto@vmware.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
This allows use of miniflows that have all of their values inline.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
This helps about 1% in TCP_CRR performance test. However, this also
helps by clearly showing the classifier_lookup() cost in perf reports
as one item.
This also cleans up the flow/match APIs from functionality only used
by the classifier, making is more straightforward to evolve them
later.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
miniflow_extract() extracts packet headers directly to a miniflow,
which is a compressed form of the struct flow. This does not require
a large struct to be cleared to begin with, and accesses less memory.
These performance benefits should allow this to be used in the DPDK
datapath.
miniflow_extract() takes a miniflow as an input/output parameter. On
input the buffer for values to be extracted must be properly
initialized. On output the map contains ones for all the fields that
have been extracted.
Some struct flow fields are reordered to make miniflow_extract to
progress in the logical order.
Some explicit "inline" keywords are necessary for GCC to optimize this
properly. Also, macros are used for same reason instead of inline
functions for pushing data to the miniflow.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Reviewed-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Infrastructure to enable megaflow support for bond ports using
recirculation. This patch adds the following features:
* Generate RECIRC action when bond can benefit from recirculation.
* Populate post recirculation rules in a hidden table. Currently table 254.
* Uses post recirculation rules for bond rebalancing
* A recirculation implementation in dpif-netdev.
The goal of this patch is to be able to megaflow bond outputs and
thus greatly improve performance. However, this patch does not
actually improve the megaflow generation. It is left for a later commit.
Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
This commit makes the userspace support for MPLS more complete. Now
up to 3 labels are supported.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Co-authored-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Simon Horman <horms@verge.net.au>
We allow zero 'values' in a miniflow for it to have the same map
as the corresponding minimask. Minimasks themselves never have
zero data values, though. Document this and optimize the code
accordingly.
v2:
- Made miniflow_get_map_in_range() to return data offset instead of
a pointer via the last parameter.
- Simplified minimatch_hash_in_range() by removing pointer arithmetic.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Refactor to remove some duplicated logic in match_format()
implemenation and make the output more uniform.
Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Allow TCP flags match specification with symbolic flag names. TCP
flags are optionally specified as a string of flag names, each
preceded by '+' when the flag must be one, or '-' when the flag must
be zero. Any flags not explicitly included are wildcarded. The
existing hex syntax is still allowed, and is used in flow dumps when
all the flags are matched.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Subtable lookup is performed in ranges defined for struct flow,
starting from metadata (registers, in_port, etc.), then L2 header, L3,
and finally L4 ports. Whenever it is found that there are no matches
in the current subtable, the rest of the subtable can be skipped. The
rationale of this logic is that as many fields as possible can remain
wildcarded.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Having a single function that can do raw_ctz() on any integer type is
easier for callers to get right, and there is no real downside in the
implementation.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
