1 This file documents version 2 of the svn protocol.
6 The Subversion protocol is specified in terms of the following
7 syntactic elements, specified using ABNF [RFC 2234]:
9 item = word / number / string / list
10 word = ALPHA *(ALPHA / DIGIT / "-") space
11 number = 1*DIGIT space
12 string = 1*DIGIT ":" *OCTET space
13 ; digits give the byte count of the *OCTET portion
14 list = "(" space *item ")" space
17 Here is an example item showing each of the syntactic elements:
19 ( word 22 6:string ( sublist ) )
21 All items end with mandatory whitespace. (In the above example, a
22 newline provides the terminating whitespace for the outer list.) It
23 is possible to parse an item without knowing its type in advance.
25 Lists are not constrained to contain items of the same type. Lists
26 can be used for tuples, optional tuples, or arrays. A tuple is a list
27 expected to contain a fixed number of items, generally of differing
28 types. An optional tuple is a list containing either zero or a fixed
29 number of items (thus "optional" here does not refer to the list's
30 presence or absence, but to the presence or absence of its contents).
31 An array is a list containing zero or more items of the same type.
33 Words are used for enumerated protocol values, while strings are used
34 for text or binary data of interest to the Subversion client or
35 server. Words are case-sensitive.
37 For convenience, this specification will define prototypes for data
38 items using a syntax like:
40 example: ( literal ( data:string ... ) )
42 A simple word such as "literal", with no colon, denotes a literal
43 word. A choice of words may be given with "|" separating the choices.
44 "name:type" specifies a parameter with the given type.
46 A type is "word", "number", "string", "list", or the name of another
47 prototype. Parentheses denote a tuple, unless the parentheses contain
48 ellipses, in which case the parentheses denote an array containing
49 zero or more elements matching the prototype preceding the ellipses.
51 If a tuple has an optional part after the fixed part, a '?' marks
52 places where the tuple is allowed to end. The following tuple could
53 contain one, three, or four or more items:
55 example: ( fixed:string ? opt1:number opt2:string ? opt3:number )
57 Brackets denote an optional tuple; they are equivalent to parentheses
58 and a leading '?'. For example, this:
60 example: ( literal (? rev:number ) ( data:string ... ) )
62 can be written more compactly like this:
64 example: ( literal [ rev:number ] ( data:string ... ) )
66 For extensibility, implementations must treat a list as matching a
67 prototype's tuple even if the list contains extra elements. The extra
68 elements must be ignored.
70 In some cases, a prototype may need to match two different kinds of
71 data items. This case will be written using "|" to separate the
72 alternatives; for example:
74 example: ( first-kind rev:number )
77 The "command response" prototype is used in several contexts of this
78 specification to indicate the success or failure of an operation. It
79 is defined as follows:
81 command-response: ( success params:list )
82 | ( failure ( err:error ... ) )
83 error: ( apr-err:number message:string file:string line:number )
85 The interpretation of parameters in a successful command response is
88 URLs and repository paths are represented as strings. They should be in
89 canonical form when sent over the protocol. However, as a matter of input
90 validation, an implementation should always canonicalize received paths if it
91 needs them in canonicalized form.
93 2. Connection establishment and protocol setup
94 ----------------------------------------------
96 By default, the client connects to the server on port 3690.
98 Upon receiving a connection, the server sends a greeting, using a
99 command response whose parameters match the prototype:
101 greeting: ( minver:number maxver:number mechs:list ( cap:word ... ) )
103 minver and maxver give the minimum and maximum Subversion protocol
104 versions supported by the server. mechs is present for historical
105 reasons, and is ignored by the client. The cap values give a list of
106 server capabilities (see section 2.1).
108 If the client does not support a protocol version within the specified
109 range, it closes the connection. Otherwise, the client responds to
110 the greeting with an item matching the prototype:
112 response: ( version:number ( cap:word ... ) url:string
113 ? ra-client:string ( ? client:string ) )
115 version gives the protocol version selected by the client. The cap
116 values give a list of client capabilities (see section 2.1). url
117 gives the URL the client is accessing. ra-client is a string
118 identifying the RA implementation, e.g. "SVN/1.6.0" or "SVNKit 1.1.4".
119 client is the string returned by svn_ra_callbacks2_t.get_client_string;
120 that callback may not be implemented, so this is optional.
122 Upon receiving the client's response to the greeting, the server sends
123 an authentication request, which is a command response whose arguments
126 auth-request: ( ( mech:word ... ) realm:string )
128 The mech values give a list of SASL mechanisms supported by the
129 server. The realm string is similar to an HTTP authentication realm
130 as defined in [RFC 2617]; it allows the server to indicate which of
131 several protection spaces the server wishes to authenticate in. If
132 the mechanism list is empty, then no authentication is required and no
133 further action takes place as part of the authentication challenge;
134 otherwise, the client responds with a tuple matching the prototype:
136 auth-response: ( mech:word [ token:string ] )
138 mech specifies the SASL mechanism and token, if present, gives the
139 "initial response" of the authentication exchange. The client may
140 specify an empty mechanism to decline authentication; otherwise, upon
141 receiving the client's auth-response, the server sends a series of
142 challenges, each a tuple matching the prototype:
144 challenge: ( step ( token:string ) )
145 | ( failure ( message:string ) )
146 | ( success [ token:string ] )
148 If the first word of the challenge is "step", then the token is
149 interpreted by the authentication mechanism, and the response token
150 transmitted to the server as a string. The server then proceeds with
151 another challenge. If the client wishes to abort the authentication
152 exchange, it may do so by closing the connection.
154 If the first word of the challenge is "success", the authentication is
155 successful. If a token is provided, it should be interpreted by the
156 authentication mechanism, but there is no response.
158 If the first word of the challenge is "failure", the authentication
159 exchange is unsuccessful. The client may then give up, or make
160 another auth-response and restart the authentication process.
162 RFC 2222 requires that a protocol profile define a service name for
163 the sake of the GSSAPI mechanism. The service name for this protocol
166 After a successful authentication exchange, the server sends a command
167 response whose parameters match the prototype:
169 repos-info: ( uuid:string repos-url:string ( cap:word ... ) )
171 uuid gives the universal unique identifier of the repository,
172 repos-url gives the URL of the repository's root directory, and the
173 cap values list the repository capabilities (that is, capabilities
174 that require both server and repository support before the server can
175 claim them as capabilities, e.g., SVN_RA_SVN_CAP_MERGEINFO).
177 The client can now begin sending commands from the main command set.
181 The following capabilities are currently defined (S indicates a server
182 capability and C indicates a client capability):
184 [CS] edit-pipeline Every released version of Subversion since 1.0
185 announces the edit-pipeline capability; starting
186 in Subversion 1.5, both client and server
187 *require* the other side to announce edit-pipeline.
188 [CS] svndiff1 If both the client and server support svndiff version
189 1, this will be used as the on-the-wire format for
190 svndiff instead of svndiff version 0.
191 [CS] accepts-svndiff2 This capability advertises support for accepting
192 svndiff2 deltas. The sender of a delta (= the editor
193 driver) may send it in any svndiff version the receiver
194 has announced it can accept.
195 [CS] absent-entries If the remote end announces support for this capability,
196 it will accept the absent-dir and absent-file editor
198 [S] commit-revprops If the server presents this capability, it supports the
199 rev-props parameter of the commit command.
201 [S] mergeinfo If the server presents this capability, it supports the
202 get-mergeinfo command. See section 3.1.1.
203 [S] depth If the server presents this capability, it understands
204 requested operational depth (see section 3.1.1) and
205 per-path ambient depth (see section 3.1.3).
206 [S] atomic-revprops If the server presents this capability, it
207 supports the change-rev-prop2 command.
209 [S] inherited-props If the server presents this capability, it supports the
210 retrieval of inherited properties via the get-dir and
211 get-file commands and also supports the get-iprops
212 command (see section 3.1.1).
213 [S] list If the server presents this capability, it supports the
214 list command (see section 3.1.1).
219 Commands match the prototypes:
221 command: ( command-name:word params:list )
223 The interpretation of command parameters is different from command to
226 Initially, the client initiates commands from the main command set,
227 and the server responds. Some commands in the main command set can
228 temporarily change the set of commands which may be issued, or change
229 the flow of control so that the server issues commands and the client
232 Here are some miscellaneous prototypes used by the command sets:
234 proplist: ( ( name:string value:string ) ... )
235 iproplist: ( ( name:string proplist ) ... )
236 propdelta: ( ( name:string [ value:string ] ) ... )
237 node-kind: none|file|dir|unknown
239 lockdesc: ( path:string token:string owner:string [ comment:string ]
240 created:string [ expires:string ] )
244 There are three command sets: the main command set, the editor command
245 set, and the report command set. Initially, the protocol begins in
246 the main command set with the client sending commands; some commands
247 can change the command set and possibly the direction of control.
249 3.1.1. Main Command Set
251 The main command set corresponds to the svn_ra interfaces. After each
252 main command is issued by the client, the server sends an auth-request
253 as described in section 2. (If no new authentication is required, the
254 auth-request contains an empty mechanism list, and the server proceeds
255 immediately to sending the command response.) Some commands include a
256 second place for auth-request point as noted below.
259 params: ( url:string )
264 response: ( rev:number )
267 params: ( date:string )
268 response: ( rev:number )
271 params: ( rev:number name:string ? value:string )
273 If value is not specified, the rev-prop is removed.
274 (Originally the value was required; for minimum impact, it was
275 changed to be optional without creating an optional tuple for
276 that one parameter as we normally do.)
279 params: ( rev:number name:string [ value:string ]
280 ( dont-care:bool ? previous-value:string ) )
282 If value is not specified, the rev-prop is removed. If dont-care is false,
283 then the rev-prop is changed only if it is currently set as previous-value
284 indicates. (If dont-care is false and previous-value is unspecified, then
285 the revision property must be previously unset.) If dont-care is true,
286 then previous-value must not be specified.
289 params: ( rev:number )
290 response: ( props:proplist )
293 params: ( rev:number name:string )
294 response: ( [ value:string ] )
297 params: ( logmsg:string ? ( ( lock-path:string lock-token:string ) ... )
298 keep-locks:bool ? rev-props:proplist )
300 Upon receiving response, client switches to editor command set.
301 Upon successful completion of edit, server sends auth-request.
302 After auth exchange completes, server sends commit-info.
303 If rev-props is present, logmsg is ignored. Only the svn:log entry in
304 rev-props (if any) will be used.
305 commit-info: ( new-rev:number date:string author:string
306 ? ( post-commit-err:string ) )
307 NOTE: when revving this, make 'logmsg' optional, or delete that parameter
308 and have the log message specified in 'rev-props'.
311 params: ( path:string [ rev:number ] want-props:bool want-contents:bool
313 response: ( [ checksum:string ] rev:number props:proplist
314 [ inherited-props:iproplist ] )
315 If want-contents is specified, then after sending response, server
316 sends file contents as a series of strings, terminated by the empty
317 string, followed by a second empty command response to indicate
318 whether an error occurred during the sending of the file.
319 NOTE: the standard client doesn't send want-iprops as true, it uses
320 get-iprops, but does send want-iprops as false to workaround a server
324 params: ( path:string [ rev:number ] want-props:bool want-contents:bool
325 ? ( field:dirent-field ... ) ? want-iprops:bool )
326 response: ( rev:number props:proplist ( entry:dirent ... )
327 [ inherited-props:iproplist ] )]
328 dirent: ( name:string kind:node-kind size:number has-props:bool
329 created-rev:number [ created-date:string ]
330 [ last-author:string ] )
331 dirent-field: kind | size | has-props | created-rev | time | last-author
333 NOTE: the standard client doesn't send want-iprops as true, it uses
334 get-iprops, but does send want-iprops as false to workaround a server
338 params: ( path:string [ rev:number ] )
339 response: ( kind:node-kind )
340 If path is non-existent, 'svn_node_none' kind is returned.
343 params: ( path:string [ rev:number ] )
344 response: ( ? entry:dirent )
345 dirent: ( kind:node-kind size:number has-props:bool
346 created-rev:number [ created-date:string ]
347 [ last-author:string ] )
348 New in svn 1.2. If path is non-existent, an empty response is returned.
351 params: ( ( path:string ... ) [ rev:number ] inherit:word
353 response: ( ( ( path:string merge-info:string ) ... ) )
354 New in svn 1.5. If no paths are specified, an empty response is
355 returned. If rev is not specified, the youngest revision is used.
358 params: ( [ rev:number ] target:string recurse:bool
359 ? depth:word send_copyfrom_args:bool ? ignore_ancestry:bool )
360 Client switches to report command set.
361 Upon finish-report, server sends auth-request.
362 After auth exchange completes, server switches to editor command set.
363 After edit completes, server sends response.
367 params: ( [ rev:number ] target:string recurse:bool url:string
368 ? depth:word ? send_copyfrom_args:bool ignore_ancestry:bool )
369 Client switches to report command set.
370 Upon finish-report, server sends auth-request.
371 After auth exchange completes, server switches to editor command set.
372 After edit completes, server sends response.
376 params: ( target:string recurse:bool ? [ rev:number ] ? depth:word )
377 Client switches to report command set.
378 Upon finish-report, server sends auth-request.
379 After auth exchange completes, server switches to editor command set.
380 After edit completes, server sends response.
384 params: ( [ rev:number ] target:string recurse:bool ignore-ancestry:bool
385 url:string ? text-deltas:bool ? depth:word )
386 Client switches to report command set.
387 Upon finish-report, server sends auth-request.
388 After auth exchange completes, server switches to editor command set.
389 After edit completes, server sends response.
393 params: ( ( target-path:string ... ) [ start-rev:number ]
394 [ end-rev:number ] changed-paths:bool strict-node:bool
396 ? include-merged-revisions:bool
397 all-revprops | revprops ( revprop:string ... ) )
398 Before sending response, server sends log entries, ending with "done".
399 If a client does not want to specify a limit, it should send 0 as the
400 limit parameter. rev-props excludes author, date, and log; they are
401 sent separately for backwards-compatibility.
402 log-entry: ( ( change:changed-path-entry ... ) rev:number
403 [ author:string ] [ date:string ] [ message:string ]
404 ? has-children:bool invalid-revnum:bool
405 revprop-count:number rev-props:proplist
406 ? subtractive-merge:bool )
408 changed-path-entry: ( path:string A|D|R|M
409 ? ( ? copy-path:string copy-rev:number )
410 ? ( ? node-kind:string ? text-mods:bool prop-mods:bool ) )
414 params: ( path:string peg-rev:number ( rev:number ... ) )
415 Before sending response, server sends location entries, ending with "done".
416 location-entry: ( rev:number abs-path:number ) | done
419 get-location-segments
420 params: ( path:string [ start-rev:number ] [ end-rev:number ] )
421 Before sending response, server sends location entries, ending with "done".
422 location-entry: ( range-start:number range-end:number [ abs-path:string ] ) | done
426 params: ( path:string [ start-rev:number ] [ end-rev:number ]
427 ? include-merged-revisions:bool )
428 Before sending response, server sends file-rev entries, ending with "done".
429 file-rev: ( path:string rev:number rev-props:proplist
430 file-props:propdelta ? merged-revision:bool )
432 After each file-rev, the file delta is sent as one or more strings,
433 terminated by the empty string. If there is no delta, server just sends
438 params: ( path:string [ comment:string ] steal-lock:bool
439 [ current-rev:number ] )
440 response: ( lock:lockdesc )
443 params: ( [ comment:string ] steal-lock:bool ( ( path:string
444 [ current-rev:number ] ) ... ) )
445 Before sending response, server sends lock cmd status and descriptions,
447 lock-info: ( success ( lock:lockdesc ) ) | ( failure ( err:error ) )
452 params: ( path:string [ token:string ] break-lock:bool )
456 params: ( break-lock:bool ( ( path:string [ token:string ] ) ... ) )
457 Before sending response, server sends unlocked paths, ending with "done".
458 pre-response: ( success ( path:string ) ) | ( failure ( err:error ) )
463 params: ( path:string )
464 response: ( [ lock:lockdesc ] )
467 params: ( path:string ? [ depth:word ] )
468 response ( ( lock:lockdesc ... ) )
471 params: ( revision:number low-water-mark:number send-deltas:bool )
472 After auth exchange completes, server switches to editor command set.
473 After edit completes, server sends response.
477 params: ( start-rev:number end-rev:number low-water-mark:number
479 After auth exchange completes, server sends each revision
480 from start-rev to end-rev, alternating between sending 'revprops'
481 entries and sending the revision in the editor command set.
482 After all revisions are complete, server sends response.
483 revprops: ( revprops:word props:proplist )
484 (revprops here is the literal word "revprops".)
488 params: ( path:string peg-rev:number end-rev:number )
489 response: ( deleted-rev:number )
492 params: ( path:string [ rev:number ] )
493 response: ( inherited-props:iproplist )
494 New in svn 1.8. If rev is not specified, the youngest revision is used.
497 params: ( path:string [ rev:number ] depth:word
498 ( field:dirent-field ... ) ? ( pattern:string ... ) )
499 Before sending response, server sends dirents, ending with "done".
500 dirent: ( rel-path:string kind:node-kind
501 ? [ size:number ] [ has-props:bool ] [ created-rev:number ]
502 [ created-date:string ] [ last-author:string ] )
504 dirent-field: kind | size | has-props | created-rev | time | last-author
507 New in svn 1.10. If rev is not specified, the youngest revision is used.
508 If the dirent-fields don't contain "kind", "unknown" will be returned
511 3.1.2. Editor Command Set
513 An edit operation produces only one response, at close-edit or
514 abort-edit time. However, the consumer may write an error response at
515 any time during the edit in order to terminate the edit operation
516 early; the driver must notice that input is waiting on the connection,
517 read the error, and send an abort-edit operation. After an error is
518 returned, the consumer must read and discard editing operations until
519 the abort-edit. In order to prevent TCP deadlock, the consumer must
520 use non-blocking I/O to send an early error response; if writing
521 blocks, the consumer must read and discard edit operations until
522 writing unblocks or it reads an abort-edit.
525 params: ( rev:number )
528 params: ( [ rev:number ] root-token:string )
531 params: ( path:string rev:number dir-token:string )
534 params: ( path:string parent-token:string child-token:string
535 [ copy-path:string copy-rev:number ] )
538 params: ( path:string parent-token:string child-token:string rev:number )
541 params: ( dir-token:string name:string [ value:string ] )
544 params: ( dir-token:string )
547 params: ( path:string parent-token:string )
550 params: ( path:string dir-token:string file-token:string
551 [ copy-path:string copy-rev:number ] )
554 params: ( path:string dir-token:string file-token:string rev:number )
557 params: ( file-token:string [ base-checksum:string ] )
560 params: ( file-token:string chunk:string )
563 params: ( file-token:string )
566 params: ( file-token:string name:string [ value:string ] )
569 params: ( file-token:string [ text-checksum:string ] )
572 params: ( path:string parent-token:string )
584 Only delivered from server to client, at the end of a replay.
586 3.1.3. Report Command Set
588 To reduce round-trip delays, report commands do not return responses.
589 Any errors resulting from a report call will be returned to the client
590 by the command which invoked the report (following an abort-edit
591 call). Errors resulting from an abort-report call are ignored.
594 params: ( path:string rev:number start-empty:bool
595 ? [ lock-token:string ] ? depth:word )
598 params: ( path:string )
601 params: ( path:string url:string rev:number start-empty:bool
602 ? [ lock-token:string ] ? depth:word )
613 This protocol may be extended in three ways, in decreasing order of
616 * Items may be added to any tuple. An old implementation will
617 ignore the extra items.
619 * Named extensions may be expressed at connection initiation time
620 by the client or server.
622 * The protocol version may be bumped. Clients and servers can then
623 choose to any range of protocol versions.
627 The current implementation limits the length of a word to 31 characters.
628 Longer words, such as capability names, will be cause an error on the
631 4.2. Extending existing commands
633 Extending an existing command is normally done by indicating that its
634 tuple is allowed to end where it currently ends, for backwards
635 compatibility, and then tacking on a new, possibly optional, item.
637 For example, diff was extended to include a new mandatory text-deltas
641 params: ( [ rev:number ] target:string recurse:bool ignore-ancestry:bool
644 params: ( [ rev:number ] target:string recurse:bool ignore-ancestry:bool
645 url:string ? text-deltas:bool )
647 The "?" says that the tuple is allowed to end here, because an old
648 client or server wouldn't know to send the new item.
650 For optional parameters, a slightly different approach must be used.
651 set-path was extended to include lock-tokens like this:
654 params: ( path:string rev:number start-empty:bool )
657 params: ( path:string rev:number start-empty:bool ? [ lock-token:string ] )
659 The new item appears in brackets because, even in the new protocol,
660 the lock-token is still optional. However, if there's no lock-token
661 to send, an empty tuple must still be transmitted so that future
662 extensions to this command remain possible.