OPENFLOW-1.1+.md

   1 OpenFlow 1.1+ support in Open vSwitch
   2 =====================================
   3
   4 Open vSwitch support for OpenFlow 1.1 and beyond is a work in
   5 progress.  This file describes the work still to be done.
   6
   7 The Plan
   8 --------
   9
  10 OpenFlow version support is not a build-time option.  A single build
  11 of Open vSwitch must be able to handle all supported versions of
  12 OpenFlow.  Ideally, even at runtime it should be able to support all
  13 protocol versions at the same time on different OpenFlow bridges (and
  14 perhaps even on the same bridge).
  15
  16 At the same time, it would be a shame to litter the core of the OVS
  17 code with lots of ugly code concerned with the details of various
  18 OpenFlow protocol versions.
  19
  20 The primary approach to compatibility is to abstract most of the
  21 details of the differences from the core code, by adding a protocol
  22 layer that translates between OF1.x and a slightly higher-level
  23 abstract representation.  The core of this approach is the many struct
  24 ofputil_* structures in lib/ofp-util.h.
  25
  26 As a consequence of this approach, OVS cannot use OpenFlow protocol
  27 definitions that closely resemble those in the OpenFlow specification,
  28 because openflow.h in different versions of the OpenFlow specification
  29 defines the same identifier with different values.  Instead,
  30 openflow-common.h contains definitions that are common to all the
  31 specifications and separate protocol version-specific headers contain
  32 protocol-specific definitions renamed so as not to conflict,
  33 e.g. OFPAT10_ENQUEUE and OFPAT11_ENQUEUE for the OpenFlow 1.0 and 1.1
  34 values for OFPAT_ENQUEUE.  Generally, in cases of conflict, the
  35 protocol layer will define a more abstract OFPUTIL_* or struct
  36 ofputil_*.
  37
  38 Here are the current approaches in a few tricky areas:
  39
  40   * Port numbering.  OpenFlow 1.0 has 16-bit port numbers and later
  41     OpenFlow versions have 32-bit port numbers.  For now, OVS
  42     support for later protocol versions requires all port numbers to
  43     fall into the 16-bit range, translating the reserved OFPP_* port
  44     numbers.
  45
  46   * Actions.  OpenFlow 1.0 and later versions have very different
  47     ideas of actions.  OVS reconciles by translating all the
  48     versions' actions (and instructions) to and from a common
  49     internal representation.
  50
  51 OpenFlow 1.1
  52 ------------
  53
  54 The list of remaining work items for OpenFlow 1.1 is below.  It is
  55 probably incomplete.
  56
  57   * Match and set double-tagged VLANs (QinQ).  This requires kernel
  58     work for reasonable performance.
  59     [optional for OF1.1+]
  60
  61   * VLANs tagged with 88a8 Ethertype.  This requires kernel work for
  62     reasonable performance.
  63     [required for OF1.1+]
  64
  65 OpenFlow 1.2
  66 ------------
  67
  68 OpenFlow 1.2 support requires OpenFlow 1.1 as a prerequisite. All the
  69 additional work specific to Openflow 1.2 are complete.  (This is based
  70 on the change log at the end of the OF1.2 spec.  I didn't compare the
  71 specs carefully yet.)
  72
  73 OpenFlow 1.3
  74 ------------
  75
  76 OpenFlow 1.3 support requires OpenFlow 1.2 as a prerequisite, plus the
  77 following additional work.  (This is based on the change log at the
  78 end of the OF1.3 spec, reusing most of the section titles directly.  I
  79 didn't compare the specs carefully yet.)
  80
  81   * Add support for multipart requests.
  82     Currently we always report OFPBRC_MULTIPART_BUFFER_OVERFLOW.
  83     [optional for OF1.3+]
  84
  85   * IPv6 extension header handling support.  Fully implementing this
  86     requires kernel support.  This likely will take some careful and
  87     probably time-consuming design work.  The actual coding, once
  88     that is all done, is probably 2 or 3 days work.
  89     [optional for OF1.3+]
  90
  91   * Per-flow meters.  OpenFlow protocol support is now implemented.
  92     Support for the special OFPM_SLOWPATH and OFPM_CONTROLLER meters
  93     is missing.  Support for the software switch is under review.
  94     [optional for OF1.3+]
  95
  96   * Auxiliary connections.  An implementation in generic code might
  97     be a week's worth of work.  The value of an implementation in
  98     generic code is questionable, though, since much of the benefit
  99     of axuiliary connections is supposed to be to take advantage of
 100     hardware support.  (We could make the kernel module somehow
 101     send packets across the auxiliary connections directly, for
 102     some kind of "hardware" support, if we judged it useful enough.)
 103     [optional for OF1.3+]
 104
 105   * Provider Backbone Bridge tagging.  I don't plan to implement
 106     this (but we'd accept an implementation).
 107     [optional for OF1.3+]
 108
 109   * On-demand flow counters.  I think this might be a real
 110     optimization in some cases for the software switch.
 111     [optional for OF1.3+]
 112
 113 OpenFlow 1.4 & ONF Extensions for 1.3.X Pack1
 114 ---------------------------------------------
 115
 116 The following features are both defined as a set of ONF Extensions
 117 for 1.3 and integrated in 1.4.
 118 When defined as an ONF Extension for 1.3, the feature is using the
 119 Experimenter mechanism with the ONF Experimenter ID.
 120 When defined integrated in 1.4, the feature use the standard OpenFlow
 121 structures (for example defined in openflow-1.4.h).
 122 The two definitions for each feature are independant and can exist in
 123 parallel in OVS.
 124
 125   * Flow entry notifications
 126     This seems to be modelled after OVS's NXST_FLOW_MONITOR.
 127     (Simon Horman is working on this.)
 128     [EXT-187]
 129     [optional for OF1.4+]
 130
 131   * Role Status
 132     Already implemented as a 1.4 feature.
 133     [EXT-191]
 134     [required for OF1.4+]
 135
 136   * Flow entry eviction
 137     OVS has flow eviction functionality.
 138     table_mod OFPTC_EVICTION, flow_mod 'importance', and
 139     table_desc ofp_table_mod_prop_eviction need to be implemented.
 140     [EXT-192-e]
 141     [optional for OF1.4+]
 142
 143   * Vacancy events
 144     [EXT-192-v]
 145     [optional for OF1.4+]
 146
 147   * Bundle
 148     Transactional modification.  OpenFlow 1.4 requires to support
 149     flow_mods and port_mods in a bundle if bundle is supported.
 150     (Not related to OVS's 'ofbundle' stuff.)
 151     [EXT-230]
 152     [optional for OF1.4+]
 153
 154   * Table synchronisation
 155     Probably not so useful to the software switch.
 156     [EXT-232]
 157     [optional for OF1.4+]
 158
 159   * Group and Meter change notifications
 160     [EXT-235]
 161     [optional for OF1.4+]
 162
 163   * Bad flow entry priority error
 164     Probably not so useful to the software switch.
 165     [EXT-236]
 166     [optional for OF1.4+]
 167
 168   * Set async config error
 169     [EXT-237]
 170     [optional for OF1.4+]
 171
 172   * PBB UCA header field
 173     See comment on Provider Backbone Bridge in section about OpenFlow 1.3.
 174     [EXT-256]
 175     [optional for OF1.4+]
 176
 177   * Multipart timeout error
 178     [EXT-264]
 179     [required for OF1.4+]
 180
 181 OpenFlow 1.4 only
 182 -----------------
 183
 184 Those features are those only available in OpenFlow 1.4, other
 185 OpenFlow 1.4 features are listed in the previous section.
 186
 187   * More extensible wire protocol
 188     Many on-wire structures got TLVs.
 189     Already implemented: port desc properties, port mod properties,
 190                          port stats properties, table mod properties,
 191                          queue stats, unified property errors.
 192     Remaining required: set-async, queue desc
 193     Remaining optional: table desc, table-status
 194     [EXT-262]
 195     [required for OF1.4+]
 196
 197   * More descriptive reasons for packet-in
 198     Distinguish OFPR_APPLY_ACTION, OFPR_ACTION_SET, OFPR_GROUP,
 199     OFPR_PACKET_OUT.  NO_MATCH was renamed to OFPR_TABLE_MISS.
 200     (OFPR_ACTION_SET and OFPR_GROUP are now supported)
 201     [EXT-136]
 202     [required for OF1.4+]
 203
 204   * Optical port properties
 205     [EXT-154]
 206     [optional for OF1.4+]
 207
 208 OpenFlow 1.5 & ONF Extensions for 1.3.X Pack2
 209 ---------------------------------------------
 210
 211 The following features are both defined as a set of ONF Extensions for
 212 1.3 and integrated in 1.5. Note that this list is not definitive as
 213 those are not yet published.
 214 When defined as an ONF Extension for 1.3, the feature is using the
 215 Experimenter mechanism with the ONF Experimenter ID.
 216 When defined integrated in 1.5, the feature use the standard OpenFlow
 217 structures (for example defined in openflow-1.5.h).
 218 The two definitions for each feature are independant and can exist in
 219 parallel in OVS.
 220
 221   * Time scheduled bundles
 222     [EXT-340]
 223     [optional for OF1.5+]
 224
 225 OpenFlow 1.5 only
 226 -----------------
 227
 228 Those features are those only available in OpenFlow 1.5, other
 229 OpenFlow 1.5 features are listed in the previous section.
 230 Note that this list is not definitive as OpenFlow 1.5 is not yet
 231 published.
 232
 233   * Egress Tables
 234     [EXT-306]
 235     [optional for OF1.5+]
 236
 237   * Packet Type aware pipeline
 238     Prototype for OVS was done during specification.
 239     [EXT-112]
 240     [optional for OF1.5+]
 241
 242   * Extensible Flow Entry Statistics
 243     [EXT-334]
 244     [required for OF1.5+]
 245
 246   * Flow Entry Statistics Trigger
 247     [EXT-335]
 248     [optional for OF1.5+]
 249
 250   * Controller connection status
 251     Prototype for OVS was done during specification.
 252     [EXT-454]
 253     [optional for OF1.5+]
 254
 255   * Meter action
 256     [EXT-379]
 257     [required for OF1.5+ if metering is supported]
 258
 259   * Enable setting all pipeline fields in packet-out
 260     Prototype for OVS was done during specification.
 261     [EXT-427]
 262     [required for OF1.5+]
 263
 264   * Port properties for pipeline fields
 265     Prototype for OVS was done during specification.
 266     [EXT-388]
 267     [optional for OF1.5+]
 268
 269   * Port property for recirculation
 270     Prototype for OVS was done during specification.
 271     [EXT-399]
 272     [optional for OF1.5+]
 273
 274 General
 275 -----
 276
 277   * ovs-ofctl(8) often lists as Nicira extensions features that
 278     later OpenFlow versions support in standard ways.
 279
 280 How to contribute
 281 -----------------
 282
 283 If you plan to contribute code for a feature, please let everyone know
 284 on ovs-dev before you start work.  This will help avoid duplicating
 285 work.
 286
 287 Please consider the following:
 288
 289   * Testing.  Please test your code.
 290
 291   * Unit tests.  Please consider writing some.  The tests directory
 292     has many examples that you can use as a starting point.
 293
 294   * ovs-ofctl.  If you add a feature that is useful for some
 295     ovs-ofctl command then you should add support for it there.
 296
 297   * Documentation.  If you add a user-visible feature, then you
 298     should document it in the appropriate manpage and mention it in
 299     NEWS as well.
 300
 301   * Coding style (see the [CodingStyle.md] file at the top of the
 302     source tree).
 303
 304   * The patch submission guidelines (see [CONTRIBUTING.md]).  I
 305     recommend using "git send-email", which automatically follows a
 306     lot of those guidelines.
 307
 308 Bug Reporting
 309 -------------
 310
 311 Please report problems to bugs@openvswitch.org.
 312
 313 [CONTRIBUTING.md]:CONTRIBUTING.md
 314 [CodingStyle.md]:CodingStyle.md