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fe36184b | 1 | <?xml version="1.0" encoding="utf-8"?> |
ec78987f | 2 | <database name="ovn-sb" title="OVN Southbound Database"> |
fe36184b BP |
3 | <p> |
4 | This database holds logical and physical configuration and state for the | |
5 | Open Virtual Network (OVN) system to support virtual network abstraction. | |
6 | For an introduction to OVN, please see <code>ovn-architecture</code>(7). | |
7 | </p> | |
8 | ||
9 | <p> | |
ec78987f JP |
10 | The OVN Southbound database sits at the center of the OVN |
11 | architecture. It is the one component that speaks both southbound | |
12 | directly to all the hypervisors and gateways, via | |
88058f19 AW |
13 | <code>ovn-controller</code>/<code>ovn-controller-vtep</code>, and |
14 | northbound to the Cloud Management System, via <code>ovn-northd</code>: | |
fe36184b BP |
15 | </p> |
16 | ||
17 | <h2>Database Structure</h2> | |
18 | ||
19 | <p> | |
ec78987f JP |
20 | The OVN Southbound database contains three classes of data with |
21 | different properties, as described in the sections below. | |
fe36184b BP |
22 | </p> |
23 | ||
24 | <h3>Physical Network (PN) data</h3> | |
25 | ||
26 | <p> | |
27 | PN tables contain information about the chassis nodes in the system. This | |
28 | contains all the information necessary to wire the overlay, such as IP | |
29 | addresses, supported tunnel types, and security keys. | |
30 | </p> | |
31 | ||
32 | <p> | |
33 | The amount of PN data is small (O(n) in the number of chassis) and it | |
34 | changes infrequently, so it can be replicated to every chassis. | |
35 | </p> | |
36 | ||
37 | <p> | |
62fdd819 | 38 | The <ref table="Chassis"/> table comprises the PN tables. |
fe36184b BP |
39 | </p> |
40 | ||
41 | <h3>Logical Network (LN) data</h3> | |
42 | ||
43 | <p> | |
44 | LN tables contain the topology of logical switches and routers, ACLs, | |
45 | firewall rules, and everything needed to describe how packets traverse a | |
46 | logical network, represented as logical datapath flows (see Logical | |
47 | Datapath Flows, below). | |
48 | </p> | |
49 | ||
50 | <p> | |
51 | LN data may be large (O(n) in the number of logical ports, ACL rules, | |
52 | etc.). Thus, to improve scaling, each chassis should receive only data | |
53 | related to logical networks in which that chassis participates. Past | |
54 | experience shows that in the presence of large logical networks, even | |
55 | finer-grained partitioning of data, e.g. designing logical flows so that | |
56 | only the chassis hosting a logical port needs related flows, pays off | |
57 | scale-wise. (This is not necessary initially but it is worth bearing in | |
58 | mind in the design.) | |
59 | </p> | |
60 | ||
61 | <p> | |
62 | The LN is a slave of the cloud management system running northbound of OVN. | |
63 | That CMS determines the entire OVN logical configuration and therefore the | |
64 | LN's content at any given time is a deterministic function of the CMS's | |
09986f8c JP |
65 | configuration, although that happens indirectly via the |
66 | <ref db="OVN_Northbound"/> database and <code>ovn-northd</code>. | |
fe36184b BP |
67 | </p> |
68 | ||
69 | <p> | |
70 | LN data is likely to change more quickly than PN data. This is especially | |
71 | true in a container environment where VMs are created and destroyed (and | |
72 | therefore added to and deleted from logical switches) quickly. | |
73 | </p> | |
74 | ||
75 | <p> | |
5868eb24 BP |
76 | <ref table="Logical_Flow"/> and <ref table="Multicast_Group"/> contain LN |
77 | data. | |
fe36184b BP |
78 | </p> |
79 | ||
80 | <h3>Bindings data</h3> | |
81 | ||
82 | <p> | |
5868eb24 BP |
83 | Bindings data link logical and physical components. They show the current |
84 | placement of logical components (such as VMs and VIFs) onto chassis, and | |
85 | map logical entities to the values that represent them in tunnel | |
86 | encapsulations. | |
fe36184b BP |
87 | </p> |
88 | ||
89 | <p> | |
90 | Bindings change frequently, at least every time a VM powers up or down | |
91 | or migrates, and especially quickly in a container environment. The | |
92 | amount of data per VM (or VIF) is small. | |
93 | </p> | |
94 | ||
95 | <p> | |
96 | Each chassis is authoritative about the VMs and VIFs that it hosts at any | |
97 | given time and can efficiently flood that state to a central location, so | |
98 | the consistency needs are minimal. | |
99 | </p> | |
100 | ||
101 | <p> | |
5868eb24 BP |
102 | The <ref table="Port_Binding"/> and <ref table="Datapath_Binding"/> tables |
103 | contain binding data. | |
fe36184b BP |
104 | </p> |
105 | ||
5868eb24 BP |
106 | <h2>Common Columns</h2> |
107 | ||
108 | <p> | |
109 | Some tables contain a special column named <code>external_ids</code>. This | |
110 | column has the same form and purpose each place that it appears, so we | |
111 | describe it here to save space later. | |
112 | </p> | |
113 | ||
114 | <dl> | |
115 | <dt><code>external_ids</code>: map of string-string pairs</dt> | |
116 | <dd> | |
117 | Key-value pairs for use by the software that manages the OVN Southbound | |
88058f19 AW |
118 | database rather than by |
119 | <code>ovn-controller</code>/<code>ovn-controller-vtep</code>. In | |
120 | particular, <code>ovn-northd</code> can use key-value pairs in this | |
121 | column to relate entities in the southbound database to higher-level | |
122 | entities (such as entities in the OVN Northbound database). Individual | |
123 | key-value pairs in this column may be documented in some cases to aid | |
124 | in understanding and troubleshooting, but the reader should not mistake | |
125 | such documentation as comprehensive. | |
5868eb24 BP |
126 | </dd> |
127 | </dl> | |
128 | ||
fe36184b BP |
129 | <table name="Chassis" title="Physical Network Hypervisor and Gateway Information"> |
130 | <p> | |
131 | Each row in this table represents a hypervisor or gateway (a chassis) in | |
132 | the physical network (PN). Each chassis, via | |
88058f19 AW |
133 | <code>ovn-controller</code>/<code>ovn-controller-vtep</code>, adds |
134 | and updates its own row, and keeps a copy of the remaining rows to | |
135 | determine how to reach other hypervisors. | |
fe36184b BP |
136 | </p> |
137 | ||
138 | <p> | |
139 | When a chassis shuts down gracefully, it should remove its own row. | |
140 | (This is not critical because resources hosted on the chassis are equally | |
141 | unreachable regardless of whether the row is present.) If a chassis | |
142 | shuts down permanently without removing its row, some kind of manual or | |
143 | automatic cleanup is eventually needed; we can devise a process for that | |
144 | as necessary. | |
145 | </p> | |
146 | ||
147 | <column name="name"> | |
148 | A chassis name, taken from <ref key="system-id" table="Open_vSwitch" | |
149 | column="external_ids" db="Open_vSwitch"/> in the Open_vSwitch | |
150 | database's <ref table="Open_vSwitch" db="Open_vSwitch"/> table. OVN does | |
151 | not prescribe a particular format for chassis names. | |
152 | </column> | |
153 | ||
09db214c | 154 | <group title="Encapsulation Configuration"> |
fe36184b | 155 | <p> |
09db214c JP |
156 | OVN uses encapsulation to transmit logical dataplane packets |
157 | between chassis. | |
fe36184b BP |
158 | </p> |
159 | ||
09db214c JP |
160 | <column name="encaps"> |
161 | Points to supported encapsulation configurations to transmit | |
162 | logical dataplane packets to this chassis. Each entry is a <ref | |
163 | table="Encap"/> record that describes the configuration. | |
fe36184b BP |
164 | </column> |
165 | </group> | |
166 | ||
62fdd819 AW |
167 | <group title="Gateway Configuration"> |
168 | <p> | |
169 | A <dfn>gateway</dfn> is a chassis that forwards traffic between the | |
170 | OVN-managed part of a logical network and a physical VLAN, extending a | |
171 | tunnel-based logical network into a physical network. Gateways are | |
88058f19 AW |
172 | typically dedicated nodes that do not host VMs and will be controlled |
173 | by <code>ovn-controller-vtep</code>. | |
fe36184b BP |
174 | </p> |
175 | ||
62fdd819 | 176 | <column name="vtep_logical_switches"> |
88058f19 AW |
177 | Stores all VTEP logical switch names connected by this gateway |
178 | chassis. The <ref table="Port_Binding"/> table entry with | |
179 | <ref column="options" table="Port_Binding"/>:<code>vtep-physical-switch</code> | |
180 | equal <ref table="Chassis"/> <ref column="name" table="Chassis"/>, and | |
181 | <ref column="options" table="Port_Binding"/>:<code>vtep-logical-switch</code> | |
182 | value in <ref table="Chassis"/> | |
183 | <ref column="vtep_logical_switches" table="Chassis"/>, will be | |
184 | associated with this <ref table="Chassis"/>. | |
fe36184b | 185 | </column> |
62fdd819 | 186 | </group> |
fe36184b BP |
187 | </table> |
188 | ||
09db214c JP |
189 | <table name="Encap" title="Encapsulation Types"> |
190 | <p> | |
191 | The <ref column="encaps" table="Chassis"/> column in the <ref | |
192 | table="Chassis"/> table refers to rows in this table to identify | |
193 | how OVN may transmit logical dataplane packets to this chassis. | |
88058f19 AW |
194 | Each chassis, via <code>ovn-controller</code>(8) or |
195 | <code>ovn-controller-vtep</code>(8), adds and updates its own rows | |
196 | and keeps a copy of the remaining rows to determine how to reach | |
197 | other chassis. | |
09db214c JP |
198 | </p> |
199 | ||
200 | <column name="type"> | |
201 | The encapsulation to use to transmit packets to this chassis. | |
b705f9ea JP |
202 | Hypervisors must use either <code>geneve</code> or |
203 | <code>stt</code>. Gateways may use <code>vxlan</code>, | |
204 | <code>geneve</code>, or <code>stt</code>. | |
09db214c JP |
205 | </column> |
206 | ||
207 | <column name="options"> | |
208 | Options for configuring the encapsulation, e.g. IPsec parameters when | |
209 | IPsec support is introduced. No options are currently defined. | |
210 | </column> | |
211 | ||
212 | <column name="ip"> | |
213 | The IPv4 address of the encapsulation tunnel endpoint. | |
214 | </column> | |
215 | </table> | |
216 | ||
5868eb24 | 217 | <table name="Logical_Flow" title="Logical Network Flows"> |
fe36184b | 218 | <p> |
09986f8c JP |
219 | Each row in this table represents one logical flow. |
220 | <code>ovn-northd</code> populates this table with logical flows | |
221 | that implement the L2 and L3 topologies specified in the | |
222 | <ref db="OVN_Northbound"/> database. Each hypervisor, via | |
223 | <code>ovn-controller</code>, translates the logical flows into | |
224 | OpenFlow flows specific to its hypervisor and installs them into | |
225 | Open vSwitch. | |
fe36184b BP |
226 | </p> |
227 | ||
228 | <p> | |
229 | Logical flows are expressed in an OVN-specific format, described here. A | |
230 | logical datapath flow is much like an OpenFlow flow, except that the | |
231 | flows are written in terms of logical ports and logical datapaths instead | |
232 | of physical ports and physical datapaths. Translation between logical | |
233 | and physical flows helps to ensure isolation between logical datapaths. | |
09986f8c JP |
234 | (The logical flow abstraction also allows the OVN centralized |
235 | components to do less work, since they do not have to separately | |
236 | compute and push out physical flows to each chassis.) | |
fe36184b BP |
237 | </p> |
238 | ||
239 | <p> | |
240 | The default action when no flow matches is to drop packets. | |
241 | </p> | |
242 | ||
69a832cf | 243 | <p><em>Architectural Logical Life Cycle of a Packet</em></p> |
5868eb24 BP |
244 | |
245 | <p> | |
246 | This following description focuses on the life cycle of a packet through | |
247 | a logical datapath, ignoring physical details of the implementation. | |
69a832cf | 248 | Please refer to <em>Architectural Physical Life Cycle of a Packet</em> in |
5868eb24 BP |
249 | <code>ovn-architecture</code>(7) for the physical information. |
250 | </p> | |
251 | ||
252 | <p> | |
253 | The description here is written as if OVN itself executes these steps, | |
254 | but in fact OVN (that is, <code>ovn-controller</code>) programs Open | |
255 | vSwitch, via OpenFlow and OVSDB, to execute them on its behalf. | |
256 | </p> | |
257 | ||
258 | <p> | |
259 | At a high level, OVN passes each packet through the logical datapath's | |
260 | logical ingress pipeline, which may output the packet to one or more | |
261 | logical port or logical multicast groups. For each such logical output | |
262 | port, OVN passes the packet through the datapath's logical egress | |
263 | pipeline, which may either drop the packet or deliver it to the | |
264 | destination. Between the two pipelines, outputs to logical multicast | |
265 | groups are expanded into logical ports, so that the egress pipeline only | |
266 | processes a single logical output port at a time. Between the two | |
267 | pipelines is also where, when necessary, OVN encapsulates a packet in a | |
268 | tunnel (or tunnels) to transmit to remote hypervisors. | |
269 | </p> | |
270 | ||
271 | <p> | |
272 | In more detail, to start, OVN searches the <ref table="Logical_Flow"/> | |
273 | table for a row with correct <ref column="logical_datapath"/>, a <ref | |
274 | column="pipeline"/> of <code>ingress</code>, a <ref column="table_id"/> | |
275 | of 0, and a <ref column="match"/> that is true for the packet. If none | |
276 | is found, OVN drops the packet. If OVN finds more than one, it chooses | |
277 | the match with the highest <ref column="priority"/>. Then OVN executes | |
278 | each of the actions specified in the row's <ref table="actions"/> column, | |
279 | in the order specified. Some actions, such as those to modify packet | |
280 | headers, require no further details. The <code>next</code> and | |
281 | <code>output</code> actions are special. | |
282 | </p> | |
283 | ||
284 | <p> | |
285 | The <code>next</code> action causes the above process to be repeated | |
286 | recursively, except that OVN searches for <ref column="table_id"/> of 1 | |
287 | instead of 0. Similarly, any <code>next</code> action in a row found in | |
288 | that table would cause a further search for a <ref column="table_id"/> of | |
289 | 2, and so on. When recursive processing completes, flow control returns | |
290 | to the action following <code>next</code>. | |
291 | </p> | |
292 | ||
293 | <p> | |
294 | The <code>output</code> action also introduces recursion. Its effect | |
295 | depends on the current value of the <code>outport</code> field. Suppose | |
296 | <code>outport</code> designates a logical port. First, OVN compares | |
297 | <code>inport</code> to <code>outport</code>; if they are equal, it treats | |
298 | the <code>output</code> as a no-op. In the common case, where they are | |
299 | different, the packet enters the egress pipeline. This transition to the | |
78aab811 JP |
300 | egress pipeline discards register data, e.g. <code>reg0</code> ... |
301 | <code>reg4</code> and connection tracking state, to achieve | |
302 | uniform behavior regardless of whether the egress pipeline is on a | |
303 | different hypervisor (because registers aren't preserve across | |
304 | tunnel encapsulation). | |
5868eb24 BP |
305 | </p> |
306 | ||
307 | <p> | |
308 | To execute the egress pipeline, OVN again searches the <ref | |
309 | table="Logical_Flow"/> table for a row with correct <ref | |
310 | column="logical_datapath"/>, a <ref column="table_id"/> of 0, a <ref | |
311 | column="match"/> that is true for the packet, but now looking for a <ref | |
312 | column="pipeline"/> of <code>egress</code>. If no matching row is found, | |
313 | the output becomes a no-op. Otherwise, OVN executes the actions for the | |
314 | matching flow (which is chosen from multiple, if necessary, as already | |
315 | described). | |
316 | </p> | |
317 | ||
318 | <p> | |
319 | In the <code>egress</code> pipeline, the <code>next</code> action acts as | |
320 | already described, except that it, of course, searches for | |
321 | <code>egress</code> flows. The <code>output</code> action, however, now | |
322 | directly outputs the packet to the output port (which is now fixed, | |
323 | because <code>outport</code> is read-only within the egress pipeline). | |
324 | </p> | |
325 | ||
326 | <p> | |
327 | The description earlier assumed that <code>outport</code> referred to a | |
328 | logical port. If it instead designates a logical multicast group, then | |
329 | the description above still applies, with the addition of fan-out from | |
330 | the logical multicast group to each logical port in the group. For each | |
331 | member of the group, OVN executes the logical pipeline as described, with | |
332 | the logical output port replaced by the group member. | |
333 | </p> | |
334 | ||
8d6e5516 JP |
335 | <p><em>Pipeline Stages</em></p> |
336 | ||
337 | <p> | |
338 | <code>ovn-northd</code> is responsible for populating the | |
339 | <ref table="Logical_Flow"/> table, so the stages are an | |
340 | implementation detail and subject to change. This section | |
341 | describes the current logical flow table. | |
342 | </p> | |
343 | ||
344 | <p> | |
345 | The ingress pipeline consists of the following stages: | |
346 | </p> | |
347 | <ul> | |
348 | <li> | |
349 | Port Security (Table 0): Validates the source address, drops | |
350 | packets with a VLAN tag, and, if configured, verifies that the | |
351 | logical port is allowed to send with the source address. | |
352 | </li> | |
353 | ||
354 | <li> | |
355 | L2 Destination Lookup (Table 1): Forwards known unicast | |
356 | addresses to the appropriate logical port. Unicast packets to | |
357 | unknown hosts are forwarded to logical ports configured with the | |
358 | special <code>unknown</code> mac address. Broadcast, and | |
359 | multicast are flooded to all ports in the logical switch. | |
360 | </li> | |
361 | </ul> | |
362 | ||
363 | <p> | |
364 | The egress pipeline consists of the following stages: | |
365 | </p> | |
366 | <ul> | |
367 | <li> | |
368 | ACL (Table 0): Applies any specified access control lists. | |
369 | </li> | |
370 | ||
371 | <li> | |
372 | Port Security (Table 1): If configured, verifies that the | |
373 | logical port is allowed to receive packets with the destination | |
374 | address. | |
375 | </li> | |
376 | </ul> | |
377 | ||
747b2a45 | 378 | <column name="logical_datapath"> |
5868eb24 BP |
379 | The logical datapath to which the logical flow belongs. |
380 | </column> | |
381 | ||
382 | <column name="pipeline"> | |
383 | <p> | |
384 | The primary flows used for deciding on a packet's destination are the | |
385 | <code>ingress</code> flows. The <code>egress</code> flows implement | |
386 | ACLs. See <em>Logical Life Cycle of a Packet</em>, above, for details. | |
387 | </p> | |
747b2a45 BP |
388 | </column> |
389 | ||
fe36184b BP |
390 | <column name="table_id"> |
391 | The stage in the logical pipeline, analogous to an OpenFlow table number. | |
392 | </column> | |
393 | ||
394 | <column name="priority"> | |
395 | The flow's priority. Flows with numerically higher priority take | |
396 | precedence over those with lower. If two logical datapath flows with the | |
397 | same priority both match, then the one actually applied to the packet is | |
398 | undefined. | |
399 | </column> | |
400 | ||
401 | <column name="match"> | |
402 | <p> | |
403 | A matching expression. OVN provides a superset of OpenFlow matching | |
404 | capabilities, using a syntax similar to Boolean expressions in a | |
405 | programming language. | |
406 | </p> | |
407 | ||
408 | <p> | |
fa6aeaeb RB |
409 | The most important components of match expression are |
410 | <dfn>comparisons</dfn> between <dfn>symbols</dfn> and | |
411 | <dfn>constants</dfn>, e.g. <code>ip4.dst == 192.168.0.1</code>, | |
412 | <code>ip.proto == 6</code>, <code>arp.op == 1</code>, <code>eth.type == | |
413 | 0x800</code>. The logical AND operator <code>&&</code> and | |
414 | logical OR operator <code>||</code> can combine comparisons into a | |
415 | larger expression. | |
fe36184b BP |
416 | </p> |
417 | ||
fe36184b | 418 | <p> |
e0840f11 BP |
419 | Matching expressions also support parentheses for grouping, the logical |
420 | NOT prefix operator <code>!</code>, and literals <code>0</code> and | |
421 | <code>1</code> to express ``false'' or ``true,'' respectively. The | |
422 | latter is useful by itself as a catch-all expression that matches every | |
423 | packet. | |
fe36184b BP |
424 | </p> |
425 | ||
e0840f11 | 426 | <p><em>Symbols</em></p> |
fe36184b BP |
427 | |
428 | <p> | |
fa6aeaeb RB |
429 | <em>Type</em>. Symbols have <dfn>integer</dfn> or <dfn>string</dfn> |
430 | type. Integer symbols have a <dfn>width</dfn> in bits. | |
fe36184b BP |
431 | </p> |
432 | ||
433 | <p> | |
fa6aeaeb | 434 | <em>Kinds</em>. There are three kinds of symbols: |
fe36184b BP |
435 | </p> |
436 | ||
e0840f11 | 437 | <ul> |
fa6aeaeb RB |
438 | <li> |
439 | <p> | |
440 | <dfn>Fields</dfn>. A field symbol represents a packet header or | |
441 | metadata field. For example, a field | |
442 | named <code>vlan.tci</code> might represent the VLAN TCI field in a | |
443 | packet. | |
444 | </p> | |
445 | ||
446 | <p> | |
447 | A field symbol can have integer or string type. Integer fields can | |
448 | be nominal or ordinal (see <em>Level of Measurement</em>, | |
449 | below). | |
450 | </p> | |
451 | </li> | |
452 | ||
453 | <li> | |
454 | <p> | |
455 | <dfn>Subfields</dfn>. A subfield represents a subset of bits from | |
456 | a larger field. For example, a field <code>vlan.vid</code> might | |
457 | be defined as an alias for <code>vlan.tci[0..11]</code>. Subfields | |
458 | are provided for syntactic convenience, because it is always | |
459 | possible to instead refer to a subset of bits from a field | |
460 | directly. | |
461 | </p> | |
462 | ||
463 | <p> | |
464 | Only ordinal fields (see <em>Level of Measurement</em>, | |
465 | below) may have subfields. Subfields are always ordinal. | |
466 | </p> | |
467 | </li> | |
468 | ||
469 | <li> | |
470 | <p> | |
471 | <dfn>Predicates</dfn>. A predicate is shorthand for a Boolean | |
472 | expression. Predicates may be used much like 1-bit fields. For | |
473 | example, <code>ip4</code> might expand to <code>eth.type == | |
474 | 0x800</code>. Predicates are provided for syntactic convenience, | |
475 | because it is always possible to instead specify the underlying | |
476 | expression directly. | |
477 | </p> | |
478 | ||
479 | <p> | |
480 | A predicate whose expansion refers to any nominal field or | |
481 | predicate (see <em>Level of Measurement</em>, below) is nominal; | |
482 | other predicates have Boolean level of measurement. | |
483 | </p> | |
484 | </li> | |
e0840f11 BP |
485 | </ul> |
486 | ||
fe36184b | 487 | <p> |
fa6aeaeb RB |
488 | <em>Level of Measurement</em>. See |
489 | http://en.wikipedia.org/wiki/Level_of_measurement for the statistical | |
490 | concept on which this classification is based. There are three | |
491 | levels: | |
fe36184b BP |
492 | </p> |
493 | ||
494 | <ul> | |
fa6aeaeb RB |
495 | <li> |
496 | <p> | |
497 | <dfn>Ordinal</dfn>. In statistics, ordinal values can be ordered | |
498 | on a scale. OVN considers a field (or subfield) to be ordinal if | |
499 | its bits can be examined individually. This is true for the | |
500 | OpenFlow fields that OpenFlow or Open vSwitch makes ``maskable.'' | |
501 | </p> | |
502 | ||
503 | <p> | |
504 | Any use of a nominal field may specify a single bit or a range of | |
505 | bits, e.g. <code>vlan.tci[13..15]</code> refers to the PCP field | |
506 | within the VLAN TCI, and <code>eth.dst[40]</code> refers to the | |
507 | multicast bit in the Ethernet destination address. | |
508 | </p> | |
509 | ||
510 | <p> | |
511 | OVN supports all the usual arithmetic relations (<code>==</code>, | |
512 | <code>!=</code>, <code><</code>, <code><=</code>, | |
513 | <code>></code>, and <code>>=</code>) on ordinal fields and | |
514 | their subfields, because OVN can implement these in OpenFlow and | |
515 | Open vSwitch as collections of bitwise tests. | |
516 | </p> | |
517 | </li> | |
518 | ||
519 | <li> | |
520 | <p> | |
521 | <dfn>Nominal</dfn>. In statistics, nominal values cannot be | |
522 | usefully compared except for equality. This is true of OpenFlow | |
523 | port numbers, Ethernet types, and IP protocols are examples: all of | |
524 | these are just identifiers assigned arbitrarily with no deeper | |
525 | meaning. In OpenFlow and Open vSwitch, bits in these fields | |
526 | generally aren't individually addressable. | |
527 | </p> | |
528 | ||
529 | <p> | |
530 | OVN only supports arithmetic tests for equality on nominal fields, | |
531 | because OpenFlow and Open vSwitch provide no way for a flow to | |
532 | efficiently implement other comparisons on them. (A test for | |
533 | inequality can be sort of built out of two flows with different | |
534 | priorities, but OVN matching expressions always generate flows with | |
535 | a single priority.) | |
536 | </p> | |
537 | ||
538 | <p> | |
539 | String fields are always nominal. | |
540 | </p> | |
541 | </li> | |
542 | ||
543 | <li> | |
544 | <p> | |
545 | <dfn>Boolean</dfn>. A nominal field that has only two values, 0 | |
546 | and 1, is somewhat exceptional, since it is easy to support both | |
547 | equality and inequality tests on such a field: either one can be | |
548 | implemented as a test for 0 or 1. | |
549 | </p> | |
550 | ||
551 | <p> | |
552 | Only predicates (see above) have a Boolean level of measurement. | |
553 | </p> | |
554 | ||
555 | <p> | |
556 | This isn't a standard level of measurement. | |
557 | </p> | |
558 | </li> | |
fe36184b BP |
559 | </ul> |
560 | ||
561 | <p> | |
fa6aeaeb RB |
562 | <em>Prerequisites</em>. Any symbol can have prerequisites, which are |
563 | additional condition implied by the use of the symbol. For example, | |
564 | For example, <code>icmp4.type</code> symbol might have prerequisite | |
565 | <code>icmp4</code>, which would cause an expression <code>icmp4.type == | |
566 | 0</code> to be interpreted as <code>icmp4.type == 0 && | |
567 | icmp4</code>, which would in turn expand to <code>icmp4.type == 0 | |
568 | && eth.type == 0x800 && ip4.proto == 1</code> (assuming | |
569 | <code>icmp4</code> is a predicate defined as suggested under | |
570 | <em>Types</em> above). | |
fe36184b BP |
571 | </p> |
572 | ||
e0840f11 BP |
573 | <p><em>Relational operators</em></p> |
574 | ||
fe36184b | 575 | <p> |
fa6aeaeb RB |
576 | All of the standard relational operators <code>==</code>, |
577 | <code>!=</code>, <code><</code>, <code><=</code>, | |
578 | <code>></code>, and <code>>=</code> are supported. Nominal | |
579 | fields support only <code>==</code> and <code>!=</code>, and only in a | |
580 | positive sense when outer <code>!</code> are taken into account, | |
581 | e.g. given string field <code>inport</code>, <code>inport == | |
582 | "eth0"</code> and <code>!(inport != "eth0")</code> are acceptable, but | |
583 | not <code>inport != "eth0"</code>. | |
fe36184b BP |
584 | </p> |
585 | ||
586 | <p> | |
fa6aeaeb RB |
587 | The implementation of <code>==</code> (or <code>!=</code> when it is |
588 | negated), is more efficient than that of the other relational | |
589 | operators. | |
fe36184b BP |
590 | </p> |
591 | ||
e0840f11 BP |
592 | <p><em>Constants</em></p> |
593 | ||
fe36184b | 594 | <p> |
e0840f11 BP |
595 | Integer constants may be expressed in decimal, hexadecimal prefixed by |
596 | <code>0x</code>, or as dotted-quad IPv4 addresses, IPv6 addresses in | |
597 | their standard forms, or Ethernet addresses as colon-separated hex | |
598 | digits. A constant in any of these forms may be followed by a slash | |
599 | and a second constant (the mask) in the same form, to form a masked | |
600 | constant. IPv4 and IPv6 masks may be given as integers, to express | |
601 | CIDR prefixes. | |
602 | </p> | |
603 | ||
604 | <p> | |
605 | String constants have the same syntax as quoted strings in JSON (thus, | |
5868eb24 | 606 | they are Unicode strings). |
fe36184b BP |
607 | </p> |
608 | ||
609 | <p> | |
e0840f11 BP |
610 | Some operators support sets of constants written inside curly braces |
611 | <code>{</code> ... <code>}</code>. Commas between elements of a set, | |
612 | and after the last elements, are optional. With <code>==</code>, | |
613 | ``<code><var>field</var> == { <var>constant1</var>, | |
614 | <var>constant2</var>,</code> ... <code>}</code>'' is syntactic sugar | |
615 | for ``<code><var>field</var> == <var>constant1</var> || | |
616 | <var>field</var> == <var>constant2</var> || </code>...<code></code>. | |
617 | Similarly, ``<code><var>field</var> != { <var>constant1</var>, | |
618 | <var>constant2</var>, </code>...<code> }</code>'' is equivalent to | |
619 | ``<code><var>field</var> != <var>constant1</var> && | |
fe36184b | 620 | <var>field</var> != <var>constant2</var> && |
e0840f11 | 621 | </code>...<code></code>''. |
fe36184b BP |
622 | </p> |
623 | ||
e0840f11 BP |
624 | <p><em>Miscellaneous</em></p> |
625 | ||
fe36184b | 626 | <p> |
fa6aeaeb RB |
627 | Comparisons may name the symbol or the constant first, |
628 | e.g. <code>tcp.src == 80</code> and <code>80 == tcp.src</code> are both | |
629 | acceptable. | |
fe36184b BP |
630 | </p> |
631 | ||
632 | <p> | |
fa6aeaeb RB |
633 | Tests for a range may be expressed using a syntax like <code>1024 <= |
634 | tcp.src <= 49151</code>, which is equivalent to <code>1024 <= | |
635 | tcp.src && tcp.src <= 49151</code>. | |
fe36184b BP |
636 | </p> |
637 | ||
638 | <p> | |
fa6aeaeb RB |
639 | For a one-bit field or predicate, a mention of its name is equivalent |
640 | to <code><var>symobl</var> == 1</code>, e.g. <code>vlan.present</code> | |
641 | is equivalent to <code>vlan.present == 1</code>. The same is true for | |
642 | one-bit subfields, e.g. <code>vlan.tci[12]</code>. There is no | |
643 | technical limitation to implementing the same for ordinal fields of all | |
644 | widths, but the implementation is expensive enough that the syntax | |
645 | parser requires writing an explicit comparison against zero to make | |
646 | mistakes less likely, e.g. in <code>tcp.src != 0</code> the comparison | |
647 | against 0 is required. | |
fe36184b BP |
648 | </p> |
649 | ||
650 | <p> | |
fa6aeaeb RB |
651 | <em>Operator precedence</em> is as shown below, from highest to lowest. |
652 | There are two exceptions where parentheses are required even though the | |
653 | table would suggest that they are not: <code>&&</code> and | |
654 | <code>||</code> require parentheses when used together, and | |
655 | <code>!</code> requires parentheses when applied to a relational | |
656 | expression. Thus, in <code>(eth.type == 0x800 || eth.type == 0x86dd) | |
657 | && ip.proto == 6</code> or <code>!(arp.op == 1)</code>, the | |
658 | parentheses are mandatory. | |
fe36184b BP |
659 | </p> |
660 | ||
e0840f11 BP |
661 | <ul> |
662 | <li><code>()</code></li> | |
663 | <li><code>== != < <= > >=</code></li> | |
664 | <li><code>!</code></li> | |
665 | <li><code>&& ||</code></li> | |
666 | </ul> | |
667 | ||
10b1662b BP |
668 | <p> |
669 | <em>Comments</em> may be introduced by <code>//</code>, which extends | |
670 | to the next new-line. Comments within a line may be bracketed by | |
671 | <code>/*</code> and <code>*/</code>. Multiline comments are not | |
672 | supported. | |
673 | </p> | |
674 | ||
e0840f11 BP |
675 | <p><em>Symbols</em></p> |
676 | ||
5868eb24 BP |
677 | <p> |
678 | Most of the symbols below have integer type. Only <code>inport</code> | |
679 | and <code>outport</code> have string type. <code>inport</code> names a | |
680 | logical port. Thus, its value is a <ref column="logical_port"/> name | |
62fdd819 AW |
681 | from the <ref table="Port_Binding"/> table. <code>outport</code> may |
682 | name a logical port, as <code>inport</code>, or a logical multicast | |
683 | group defined in the <ref table="Multicast_Group"/> table. For both | |
684 | symbols, only names within the flow's logical datapath may be used. | |
5868eb24 BP |
685 | </p> |
686 | ||
e0840f11 | 687 | <ul> |
78aab811 | 688 | <li><code>reg0</code>...<code>reg4</code></li> |
5868eb24 | 689 | <li><code>inport</code> <code>outport</code></li> |
e0840f11 BP |
690 | <li><code>eth.src</code> <code>eth.dst</code> <code>eth.type</code></li> |
691 | <li><code>vlan.tci</code> <code>vlan.vid</code> <code>vlan.pcp</code> <code>vlan.present</code></li> | |
692 | <li><code>ip.proto</code> <code>ip.dscp</code> <code>ip.ecn</code> <code>ip.ttl</code> <code>ip.frag</code></li> | |
693 | <li><code>ip4.src</code> <code>ip4.dst</code></li> | |
694 | <li><code>ip6.src</code> <code>ip6.dst</code> <code>ip6.label</code></li> | |
695 | <li><code>arp.op</code> <code>arp.spa</code> <code>arp.tpa</code> <code>arp.sha</code> <code>arp.tha</code></li> | |
696 | <li><code>tcp.src</code> <code>tcp.dst</code> <code>tcp.flags</code></li> | |
697 | <li><code>udp.src</code> <code>udp.dst</code></li> | |
698 | <li><code>sctp.src</code> <code>sctp.dst</code></li> | |
699 | <li><code>icmp4.type</code> <code>icmp4.code</code></li> | |
700 | <li><code>icmp6.type</code> <code>icmp6.code</code></li> | |
701 | <li><code>nd.target</code> <code>nd.sll</code> <code>nd.tll</code></li> | |
78aab811 JP |
702 | <li> |
703 | <p> | |
704 | <code>ct_state</code>, which has the following Boolean subfields: | |
705 | </p> | |
706 | <ul> | |
707 | <li><code>ct.new</code>: True for a new flow</li> | |
708 | <li><code>ct.est</code>: True for an established flow</li> | |
709 | <li><code>ct.rel</code>: True for a related flow</li> | |
710 | <li><code>ct.rpl</code>: True for a reply flow</li> | |
711 | <li><code>ct.inv</code>: True for a connection entry in a bad state</li> | |
712 | </ul> | |
713 | <p> | |
714 | <code>ct_state</code> and its subfields are initialized by the | |
715 | <code>ct_next</code> action, described below. | |
716 | </p> | |
717 | </li> | |
e0840f11 BP |
718 | </ul> |
719 | ||
25030d47 RB |
720 | <p> |
721 | The following predicates are supported: | |
722 | </p> | |
723 | ||
724 | <ul> | |
725 | <li><code>vlan.present</code> expands to <code>vlan.tci[12]</code></li> | |
726 | <li><code>ip4</code> expands to <code>eth.type == 0x800</code></li> | |
727 | <li><code>ip6</code> expands to <code>eth.type == 0x86dd</code></li> | |
728 | <li><code>ip</code> expands to <code>ip4 || ip6</code></li> | |
729 | <li><code>icmp4</code> expands to <code>ip4 && ip.proto == 1</code></li> | |
730 | <li><code>icmp6</code> expands to <code>ip6 && ip.proto == 58</code></li> | |
731 | <li><code>icmp</code> expands to <code>icmp4 || icmp6</code></li> | |
732 | <li><code>ip.is_frag</code> expands to <code>ip.frag[0]</code></li> | |
733 | <li><code>ip.later_frag</code> expands to <code>ip.frag[1]</code></li> | |
734 | <li><code>ip.first_frag</code> expands to <code>ip.is_frag && !ip.later_frag</code></li> | |
735 | <li><code>arp</code> expands to <code>eth.type == 0x806</code></li> | |
736 | <li><code>nd</code> expands to <code>icmp6.type == {135, 136} && icmp6.code == 0</code></li> | |
737 | <li><code>tcp</code> expands to <code>ip.proto == 6</code></li> | |
738 | <li><code>udp</code> expands to <code>ip.proto == 17</code></li> | |
739 | <li><code>sctp</code> expands to <code>ip.proto == 132</code></li> | |
740 | </ul> | |
fe36184b BP |
741 | </column> |
742 | ||
743 | <column name="actions"> | |
744 | <p> | |
2cd87fce RB |
745 | Logical datapath actions, to be executed when the logical flow |
746 | represented by this row is the highest-priority match. | |
fe36184b BP |
747 | </p> |
748 | ||
35060cdc | 749 | <p> |
2cd87fce RB |
750 | Actions share lexical syntax with the <ref column="match"/> column. An |
751 | empty set of actions (or one that contains just white space or | |
752 | comments), or a set of actions that consists of just | |
753 | <code>drop;</code>, causes the matched packets to be dropped. | |
754 | Otherwise, the column should contain a sequence of actions, each | |
755 | terminated by a semicolon. | |
35060cdc | 756 | </p> |
fe36184b | 757 | |
35060cdc | 758 | <p> |
eee7a8ed | 759 | The following actions are defined: |
35060cdc | 760 | </p> |
fe36184b | 761 | |
35060cdc BP |
762 | <dl> |
763 | <dt><code>output;</code></dt> | |
764 | <dd> | |
5868eb24 | 765 | <p> |
eee7a8ed JP |
766 | In the ingress pipeline, this action executes the |
767 | <code>egress</code> pipeline as a subroutine. If | |
768 | <code>outport</code> names a logical port, the egress pipeline | |
769 | executes once; if it is a multicast group, the egress pipeline runs | |
770 | once for each logical port in the group. | |
5868eb24 BP |
771 | </p> |
772 | ||
773 | <p> | |
774 | In the egress pipeline, this action performs the actual | |
775 | output to the <code>outport</code> logical port. (In the egress | |
776 | pipeline, <code>outport</code> never names a multicast group.) | |
777 | </p> | |
778 | ||
779 | <p> | |
780 | Output to the input port is implicitly dropped, that is, | |
781 | <code>output</code> becomes a no-op if <code>outport</code> == | |
782 | <code>inport</code>. | |
783 | </p> | |
eee7a8ed | 784 | </dd> |
fe36184b | 785 | |
35060cdc | 786 | <dt><code>next;</code></dt> |
558ec83d | 787 | <dt><code>next(<var>table</var>);</code></dt> |
35060cdc | 788 | <dd> |
558ec83d BP |
789 | Executes another logical datapath table as a subroutine. By default, |
790 | the table after the current one is executed. Specify | |
791 | <var>table</var> to jump to a specific table in the same pipeline. | |
2cd87fce | 792 | </dd> |
fe36184b | 793 | |
35060cdc BP |
794 | <dt><code><var>field</var> = <var>constant</var>;</code></dt> |
795 | <dd> | |
5868eb24 | 796 | <p> |
5ee054fb BP |
797 | Sets data or metadata field <var>field</var> to constant value |
798 | <var>constant</var>, e.g. <code>outport = "vif0";</code> to set the | |
799 | logical output port. To set only a subset of bits in a field, | |
800 | specify a subfield for <var>field</var> or a masked | |
801 | <var>constant</var>, e.g. one may use <code>vlan.pcp[2] = 1;</code> | |
802 | or <code>vlan.pcp = 4/4;</code> to set the most sigificant bit of | |
803 | the VLAN PCP. | |
5868eb24 BP |
804 | </p> |
805 | ||
806 | <p> | |
807 | Assigning to a field with prerequisites implicitly adds those | |
808 | prerequisites to <ref column="match"/>; thus, for example, a flow | |
809 | that sets <code>tcp.dst</code> applies only to TCP flows, | |
810 | regardless of whether its <ref column="match"/> mentions any TCP | |
811 | field. | |
812 | </p> | |
813 | ||
814 | <p> | |
815 | Not all fields are modifiable (e.g. <code>eth.type</code> and | |
816 | <code>ip.proto</code> are read-only), and not all modifiable fields | |
817 | may be partially modified (e.g. <code>ip.ttl</code> must assigned | |
818 | as a whole). The <code>outport</code> field is modifiable in the | |
819 | <code>ingress</code> pipeline but not in the <code>egress</code> | |
820 | pipeline. | |
821 | </p> | |
eee7a8ed | 822 | </dd> |
5ee054fb BP |
823 | |
824 | <dt><code><var>field1</var> = <var>field2</var>;</code></dt> | |
825 | <dd> | |
826 | <p> | |
827 | Sets data or metadata field <var>field1</var> to the value of data | |
828 | or metadata field <var>field2</var>, e.g. <code>reg0 = | |
829 | ip4.src;</code> copies <code>ip4.src</code> into <code>reg0</code>. | |
830 | To modify only a subset of a field's bits, specify a subfield for | |
831 | <var>field1</var> or <var>field2</var> or both, e.g. <code>vlan.pcp | |
832 | = reg0[0..2];</code> copies the least-significant bits of | |
833 | <code>reg0</code> into the VLAN PCP. | |
834 | </p> | |
835 | ||
836 | <p> | |
837 | <var>field1</var> and <var>field2</var> must be the same type, | |
838 | either both string or both integer fields. If they are both | |
839 | integer fields, they must have the same width. | |
840 | </p> | |
841 | ||
842 | <p> | |
843 | If <var>field1</var> or <var>field2</var> has prerequisites, they | |
844 | are added implicitly to <ref column="match"/>. It is possible to | |
845 | write an assignment with contradictory prerequisites, such as | |
846 | <code>ip4.src = ip6.src[0..31];</code>, but the contradiction means | |
847 | that a logical flow with such an assignment will never be matched. | |
848 | </p> | |
849 | </dd> | |
a20c96c6 BP |
850 | |
851 | <dt><code><var>field1</var> <-> <var>field2</var>;</code></dt> | |
852 | <dd> | |
853 | <p> | |
854 | Similar to <code><var>field1</var> = <var>field2</var>;</code> | |
855 | except that the two values are exchanged instead of copied. Both | |
856 | <var>field1</var> and <var>field2</var> must modifiable. | |
857 | </p> | |
858 | </dd> | |
78aab811 | 859 | |
00ea19e4 BP |
860 | <dt><code>ip.ttl--;</code></dt> |
861 | <dd> | |
862 | <p> | |
863 | Decrements the IPv4 or IPv6 TTL. If this would make the TTL zero | |
864 | or negative, then processing of the packet halts; no further | |
865 | actions are processed. (To properly handle such cases, a | |
866 | higher-priority flow should match on <code>ip.ttl < 2</code>.) | |
867 | </p> | |
868 | ||
869 | <p><b>Prerequisite:</b> <code>ip</code></p> | |
870 | </dd> | |
871 | ||
78aab811 JP |
872 | <dt><code>ct_next;</code></dt> |
873 | <dd> | |
874 | <p> | |
875 | Apply connection tracking to the flow, initializing | |
876 | <code>ct_state</code> for matching in later tables. | |
877 | Automatically moves on to the next table, as if followed by | |
878 | <code>next</code>. | |
879 | </p> | |
880 | ||
881 | <p> | |
882 | As a side effect, IP fragments will be reassembled for matching. | |
883 | If a fragmented packet is output, then it will be sent with any | |
884 | overlapping fragments squashed. The connection tracking state is | |
885 | scoped by the logical port, so overlapping addresses may be used. | |
886 | To allow traffic related to the matched flow, execute | |
887 | <code>ct_commit</code>. | |
888 | </p> | |
889 | ||
890 | <p> | |
891 | It is possible to have actions follow <code>ct_next</code>, | |
892 | but they will not have access to any of its side-effects and | |
893 | is not generally useful. | |
894 | </p> | |
895 | </dd> | |
896 | ||
897 | <dt><code>ct_commit;</code></dt> | |
898 | <dd> | |
899 | Commit the flow to the connection tracking entry associated | |
900 | with it by a previous call to <code>ct_next</code>. | |
901 | </dd> | |
fe36184b BP |
902 | </dl> |
903 | ||
904 | <p> | |
2cd87fce RB |
905 | The following actions will likely be useful later, but they have not |
906 | been thought out carefully. | |
fe36184b BP |
907 | </p> |
908 | ||
909 | <dl> | |
fe36184b | 910 | |
69a832cf BP |
911 | <dt><code>arp { <var>action</var>; </code>...<code> };</code></dt> |
912 | <dd> | |
913 | <p> | |
914 | Temporarily replaces the IPv4 packet being processed by an ARP | |
915 | packet and executes each nested <var>action</var> on the ARP | |
916 | packet. Actions following the <var>arp</var> action, if any, apply | |
917 | to the original, unmodified packet. | |
918 | </p> | |
919 | ||
920 | <p> | |
921 | The ARP packet that this action operates on is initialized based on | |
922 | the IPv4 packet being processed, as follows. These are default | |
923 | values that the nested actions will probably want to change: | |
924 | </p> | |
925 | ||
926 | <ul> | |
927 | <li><code>eth.src</code> unchanged</li> | |
928 | <li><code>eth.dst</code> unchanged</li> | |
929 | <li><code>eth.type = 0x0806</code></li> | |
930 | <li><code>arp.op = 1</code> (ARP request)</li> | |
931 | <li><code>arp.sha</code> copied from <code>eth.src</code></li> | |
932 | <li><code>arp.spa</code> copied from <code>ip4.src</code></li> | |
933 | <li><code>arp.tha = 00:00:00:00:00:00</code></li> | |
934 | <li><code>arp.tpa</code> copied from <code>ip4.dst</code></li> | |
935 | </ul> | |
936 | ||
937 | <p><b>Prerequisite:</b> <code>ip4</code></p> | |
938 | </dd> | |
939 | ||
940 | <dt><code>icmp4 { <var>action</var>; </code>...<code> };</code></dt> | |
941 | <dd> | |
942 | <p> | |
943 | Temporarily replaces the IPv4 packet being processed by an ICMPv4 | |
944 | packet and executes each nested <var>action</var> on the ICMPv4 | |
945 | packet. Actions following the <var>icmp4</var> action, if any, | |
946 | apply to the original, unmodified packet. | |
947 | </p> | |
948 | ||
949 | <p> | |
950 | The ICMPv4 packet that this action operates on is initialized based | |
951 | on the IPv4 packet being processed, as follows. These are default | |
952 | values that the nested actions will probably want to change. | |
953 | Ethernet and IPv4 fields not listed here are not changed: | |
954 | </p> | |
955 | ||
956 | <ul> | |
957 | <li><code>ip.proto = 1</code> (ICMPv4)</li> | |
958 | <li><code>ip.frag = 0</code> (not a fragment)</li> | |
959 | <li><code>icmp4.type = 3</code> (destination unreachable)</li> | |
960 | <li><code>icmp4.code = 1</code> (host unreachable)</li> | |
961 | </ul> | |
962 | ||
963 | <p> | |
964 | Details TBD. | |
965 | </p> | |
fe36184b | 966 | |
69a832cf BP |
967 | <p><b>Prerequisite:</b> <code>ip4</code></p> |
968 | </dd> | |
969 | ||
970 | <dt><code>tcp_reset;</code></dt> | |
971 | <dd> | |
972 | <p> | |
973 | This action transforms the current TCP packet according to the | |
974 | following pseudocode: | |
975 | </p> | |
976 | ||
977 | <pre> | |
978 | if (tcp.ack) { | |
979 | tcp.seq = tcp.ack; | |
980 | } else { | |
981 | tcp.ack = tcp.seq + length(tcp.payload); | |
982 | tcp.seq = 0; | |
983 | } | |
984 | tcp.flags = RST; | |
985 | </pre> | |
986 | ||
987 | <p> | |
988 | Then, the action drops all TCP options and payload data, and | |
989 | updates the TCP checksum. | |
990 | </p> | |
991 | ||
992 | <p> | |
993 | Details TBD. | |
994 | </p> | |
995 | ||
996 | <p><b>Prerequisite:</b> <code>tcp</code></p> | |
997 | </dd> | |
fe36184b | 998 | </dl> |
fe36184b | 999 | </column> |
091e3af9 JP |
1000 | |
1001 | <column name="external_ids" key="stage-name"> | |
1002 | Human-readable name for this flow's stage in the pipeline. | |
1003 | </column> | |
1004 | ||
1005 | <group title="Common Columns"> | |
1006 | The overall purpose of these columns is described under <code>Common | |
1007 | Columns</code> at the beginning of this document. | |
1008 | ||
1009 | <column name="external_ids"/> | |
1010 | </group> | |
fe36184b BP |
1011 | </table> |
1012 | ||
5868eb24 BP |
1013 | <table name="Multicast_Group" title="Logical Port Multicast Groups"> |
1014 | <p> | |
1015 | The rows in this table define multicast groups of logical ports. | |
1016 | Multicast groups allow a single packet transmitted over a tunnel to a | |
1017 | hypervisor to be delivered to multiple VMs on that hypervisor, which | |
1018 | uses bandwidth more efficiently. | |
1019 | </p> | |
1020 | ||
1021 | <p> | |
1022 | Each row in this table defines a logical multicast group numbered <ref | |
1023 | column="tunnel_key"/> within <ref column="datapath"/>, whose logical | |
1024 | ports are listed in the <ref column="ports"/> column. | |
1025 | </p> | |
1026 | ||
1027 | <column name="datapath"> | |
1028 | The logical datapath in which the multicast group resides. | |
1029 | </column> | |
1030 | ||
1031 | <column name="tunnel_key"> | |
1032 | The value used to designate this logical egress port in tunnel | |
1033 | encapsulations. An index forces the key to be unique within the <ref | |
1034 | column="datapath"/>. The unusual range ensures that multicast group IDs | |
1035 | do not overlap with logical port IDs. | |
1036 | </column> | |
1037 | ||
1038 | <column name="name"> | |
1039 | <p> | |
1040 | The logical multicast group's name. An index forces the name to be | |
1041 | unique within the <ref column="datapath"/>. Logical flows in the | |
1042 | ingress pipeline may output to the group just as for individual logical | |
1043 | ports, by assigning the group's name to <code>outport</code> and | |
1044 | executing an <code>output</code> action. | |
1045 | </p> | |
1046 | ||
1047 | <p> | |
1048 | Multicast group names and logical port names share a single namespace | |
1049 | and thus should not overlap (but the database schema cannot enforce | |
1050 | this). To try to avoid conflicts, <code>ovn-northd</code> uses names | |
1051 | that begin with <code>_MC_</code>. | |
1052 | </p> | |
1053 | </column> | |
1054 | ||
1055 | <column name="ports"> | |
1056 | The logical ports included in the multicast group. All of these ports | |
1057 | must be in the <ref column="datapath"/> logical datapath (but the | |
1058 | database schema cannot enforce this). | |
1059 | </column> | |
1060 | </table> | |
1061 | ||
1062 | <table name="Datapath_Binding" title="Physical-Logical Datapath Bindings"> | |
1063 | <p> | |
1064 | Each row in this table identifies physical bindings of a logical | |
1065 | datapath. A logical datapath implements a logical pipeline among the | |
1066 | ports in the <ref table="Port_Binding"/> table associated with it. In | |
1067 | practice, the pipeline in a given logical datapath implements either a | |
1068 | logical switch or a logical router. | |
1069 | </p> | |
1070 | ||
1071 | <column name="tunnel_key"> | |
1072 | The tunnel key value to which the logical datapath is bound. | |
1073 | The <code>Tunnel Encapsulation</code> section in | |
1074 | <code>ovn-architecture</code>(7) describes how tunnel keys are | |
1075 | constructed for each supported encapsulation. | |
1076 | </column> | |
1077 | ||
1078 | <column name="external_ids" key="logical-switch" type='{"type": "uuid"}'> | |
1079 | Each row in <ref table="Datapath_Binding"/> is associated with some | |
1080 | logical datapath. <code>ovn-northd</code> uses this key to store the | |
1081 | UUID of the logical datapath <ref table="Logical_Switch" | |
1082 | db="OVN_Northbound"/> row in the <ref db="OVN_Northbound"/> database. | |
1083 | </column> | |
1084 | ||
1085 | <group title="Common Columns"> | |
1086 | The overall purpose of these columns is described under <code>Common | |
1087 | Columns</code> at the beginning of this document. | |
1088 | ||
1089 | <column name="external_ids"/> | |
1090 | </group> | |
1091 | </table> | |
1092 | ||
dcda6e0d | 1093 | <table name="Port_Binding" title="Physical-Logical Port Bindings"> |
fe36184b BP |
1094 | <p> |
1095 | Each row in this table identifies the physical location of a logical | |
9fb4636f | 1096 | port. |
fe36184b BP |
1097 | </p> |
1098 | ||
1099 | <p> | |
9fb4636f | 1100 | For every <code>Logical_Port</code> record in <code>OVN_Northbound</code> |
91ae2065 RB |
1101 | database, <code>ovn-northd</code> creates a record in this table. |
1102 | <code>ovn-northd</code> populates and maintains every column except | |
3213e9df | 1103 | the <code>chassis</code> column, which it leaves empty in new records. |
9fb4636f GS |
1104 | </p> |
1105 | ||
1106 | <p> | |
88058f19 AW |
1107 | <code>ovn-controller</code>/<code>ovn-controller-vtep</code> |
1108 | populates the <code>chassis</code> column for the records that | |
1109 | identify the logical ports that are located on its hypervisor/gateway, | |
1110 | which <code>ovn-controller</code>/<code>ovn-controller-vtep</code> in | |
1111 | turn finds out by monitoring the local hypervisor's Open_vSwitch | |
1112 | database, which identifies logical ports via the conventions described | |
1113 | in <code>IntegrationGuide.md</code>. | |
9fb4636f GS |
1114 | </p> |
1115 | ||
1116 | <p> | |
5868eb24 | 1117 | When a chassis shuts down gracefully, it should clean up the |
9fb4636f | 1118 | <code>chassis</code> column that it previously had populated. |
fe36184b BP |
1119 | (This is not critical because resources hosted on the chassis are equally |
1120 | unreachable regardless of whether their rows are present.) To handle the | |
1121 | case where a VM is shut down abruptly on one chassis, then brought up | |
88058f19 AW |
1122 | again on a different one, |
1123 | <code>ovn-controller</code>/<code>ovn-controller-vtep</code> must | |
1124 | overwrite the <code>chassis</code> column with new information. | |
fe36184b BP |
1125 | </p> |
1126 | ||
c96ba502 BP |
1127 | <group title="Core Features"> |
1128 | <column name="datapath"> | |
1129 | The logical datapath to which the logical port belongs. | |
1130 | </column> | |
1a76c93e | 1131 | |
c96ba502 BP |
1132 | <column name="logical_port"> |
1133 | A logical port, taken from <ref table="Logical_Port" column="name" | |
1134 | db="OVN_Northbound"/> in the OVN_Northbound database's <ref | |
1135 | table="Logical_Port" db="OVN_Northbound"/> table. OVN does not | |
1136 | prescribe a particular format for the logical port ID. | |
1137 | </column> | |
c0281929 | 1138 | |
c96ba502 BP |
1139 | <column name="chassis"> |
1140 | The physical location of the logical port. To successfully identify a | |
1141 | chassis, this column must be a <ref table="Chassis"/> record. This is | |
1142 | populated by | |
1143 | <code>ovn-controller</code>/<code>ovn-controller-vtep</code>. | |
1144 | </column> | |
c0281929 | 1145 | |
c96ba502 BP |
1146 | <column name="tunnel_key"> |
1147 | <p> | |
1148 | A number that represents the logical port in the key (e.g. STT key or | |
1149 | Geneve TLV) field carried within tunnel protocol packets. | |
1150 | </p> | |
c0281929 | 1151 | |
c96ba502 BP |
1152 | <p> |
1153 | The tunnel ID must be unique within the scope of a logical datapath. | |
1154 | </p> | |
1155 | </column> | |
88058f19 | 1156 | |
c96ba502 BP |
1157 | <column name="mac"> |
1158 | <p> | |
1159 | The Ethernet address or addresses used as a source address on the | |
1160 | logical port, each in the form | |
1161 | <var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>:<var>xx</var>. | |
1162 | The string <code>unknown</code> is also allowed to indicate that the | |
1163 | logical port has an unknown set of (additional) source addresses. | |
1164 | </p> | |
1165 | ||
1166 | <p> | |
1167 | A VM interface would ordinarily have a single Ethernet address. A | |
1168 | gateway port might initially only have <code>unknown</code>, and then | |
1169 | add MAC addresses to the set as it learns new source addresses. | |
1170 | </p> | |
1171 | </column> | |
88058f19 | 1172 | |
c96ba502 BP |
1173 | <column name="type"> |
1174 | <p> | |
1175 | A type for this logical port. Logical ports can be used to model other | |
1176 | types of connectivity into an OVN logical switch. The following types | |
1177 | are defined: | |
1178 | </p> | |
1179 | ||
1180 | <dl> | |
1181 | <dt>(empty string)</dt> | |
1182 | <dd>VM (or VIF) interface.</dd> | |
1183 | <dt><code>localnet</code></dt> | |
1184 | <dd> | |
1185 | A connection to a locally accessible network from each | |
1186 | <code>ovn-controller</code> instance. A logical switch can only | |
1187 | have a single <code>localnet</code> port attached and at most one | |
1188 | regular logical port. This is used to model direct connectivity to | |
1189 | an existing network. | |
1190 | </dd> | |
1191 | ||
1192 | <dt><code>vtep</code></dt> | |
1193 | <dd> | |
1194 | A port to a logical switch on a VTEP gateway chassis. In order to | |
1195 | get this port correctly recognized by the OVN controller, the <ref | |
1196 | column="options" | |
1197 | table="Port_Binding"/>:<code>vtep-physical-switch</code> and <ref | |
1198 | column="options" | |
1199 | table="Port_Binding"/>:<code>vtep-logical-switch</code> must also | |
1200 | be defined. | |
1201 | </dd> | |
1202 | </dl> | |
1203 | </column> | |
1204 | </group> | |
1a76c93e | 1205 | |
c96ba502 | 1206 | <group title="Localnet Options"> |
eb00399e | 1207 | <p> |
c96ba502 BP |
1208 | These options apply to logical ports with <ref column="type"/> of |
1209 | <code>localnet</code>. | |
eb00399e BP |
1210 | </p> |
1211 | ||
c96ba502 BP |
1212 | <column name="options" key="network_name"> |
1213 | Required. <code>ovn-controller</code> uses the configuration entry | |
1214 | <code>ovn-bridge-mappings</code> to determine how to connect to this | |
1215 | network. <code>ovn-bridge-mappings</code> is a list of network names | |
1216 | mapped to a local OVS bridge that provides access to that network. An | |
1217 | example of configuring <code>ovn-bridge-mappings</code> would be: | |
1218 | ||
1219 | <pre>$ ovs-vsctl set open . external-ids:ovn-bridge-mappings=physnet1:br-eth0,physnet2:br-eth1</pre> | |
1220 | ||
1221 | <p> | |
1222 | When a logical switch has a <code>localnet</code> port attached, | |
1223 | every chassis that may have a local vif attached to that logical | |
1224 | switch must have a bridge mapping configured to reach that | |
1225 | <code>localnet</code>. Traffic that arrives on a | |
1226 | <code>localnet</code> port is never forwarded over a tunnel to | |
1227 | another chassis. | |
1228 | </p> | |
1229 | </column> | |
1230 | ||
1231 | <column name="tag"> | |
1232 | If set, indicates that the port represents a connection to a specific | |
1233 | VLAN on a locally accessible network. The VLAN ID is used to match | |
1234 | incoming traffic and is also added to outgoing traffic. | |
1235 | </column> | |
1236 | </group> | |
1237 | ||
1238 | <group title="VTEP Options"> | |
eb00399e | 1239 | <p> |
c96ba502 BP |
1240 | These options apply to logical ports with <ref column="type"/> of |
1241 | <code>vtep</code>. | |
eb00399e | 1242 | </p> |
9fb4636f | 1243 | |
c96ba502 BP |
1244 | <column name="options" key="vtep-physical-switch"> |
1245 | Required. The name of the VTEP gateway. | |
1246 | </column> | |
fe36184b | 1247 | |
c96ba502 BP |
1248 | <column name="options" key="vtep-logical-switch"> |
1249 | Required. A logical switch name connected by the VTEP gateway. Must | |
1250 | be set when <ref column="type"/> is <code>vtep</code>. | |
1251 | </column> | |
1252 | </group> | |
fe36184b | 1253 | |
c96ba502 | 1254 | <group title="Nested Containers"> |
fe36184b | 1255 | <p> |
c96ba502 BP |
1256 | These columns support containers nested within a VM. Specifically, |
1257 | they are used when <ref column="type"/> is empty and <ref | |
1258 | column="logical_port"/> identifies the interface of a container spawned | |
1259 | inside a VM. They are empty for containers or VMs that run directly on | |
1260 | a hypervisor. | |
fe36184b BP |
1261 | </p> |
1262 | ||
c96ba502 BP |
1263 | <column name="parent_port"> |
1264 | This is taken from | |
1265 | <ref table="Logical_Port" column="parent_name" db="OVN_Northbound"/> | |
1266 | in the OVN_Northbound database's <ref table="Logical_Port" | |
1267 | db="OVN_Northbound"/> table. | |
1268 | </column> | |
1269 | ||
1270 | <column name="tag"> | |
1271 | <p> | |
1272 | Identifies the VLAN tag in the network traffic associated with that | |
1273 | container's network interface. | |
1274 | </p> | |
1275 | ||
1276 | <p> | |
1277 | This column is used for a different purpose when <ref column="type"/> | |
1278 | is <code>localnet</code> (see <code>Localnet Options</code>, above). | |
1279 | </p> | |
1280 | </column> | |
1281 | </group> | |
fe36184b BP |
1282 | </table> |
1283 | </database> |