diff options
Diffstat (limited to 'Documentation/technical/pack-protocol.txt')
| -rw-r--r-- | Documentation/technical/pack-protocol.txt | 84 |
1 files changed, 69 insertions, 15 deletions
diff --git a/Documentation/technical/pack-protocol.txt b/Documentation/technical/pack-protocol.txt index c59ac9936a..cd31edc91e 100644 --- a/Documentation/technical/pack-protocol.txt +++ b/Documentation/technical/pack-protocol.txt @@ -39,6 +39,19 @@ communicates with that invoked process over the SSH connection. The file:// transport runs the 'upload-pack' or 'receive-pack' process locally and communicates with it over a pipe. +Extra Parameters +---------------- + +The protocol provides a mechanism in which clients can send additional +information in its first message to the server. These are called "Extra +Parameters", and are supported by the Git, SSH, and HTTP protocols. + +Each Extra Parameter takes the form of `<key>=<value>` or `<key>`. + +Servers that receive any such Extra Parameters MUST ignore all +unrecognized keys. Currently, the only Extra Parameter recognized is +"version=1". + Git Transport ------------- @@ -46,18 +59,25 @@ The Git transport starts off by sending the command and repository on the wire using the pkt-line format, followed by a NUL byte and a hostname parameter, terminated by a NUL byte. - 0032git-upload-pack /project.git\0host=myserver.com\0 + 0033git-upload-pack /project.git\0host=myserver.com\0 + +The transport may send Extra Parameters by adding an additional NUL +byte, and then adding one or more NUL-terminated strings: + + 003egit-upload-pack /project.git\0host=myserver.com\0\0version=1\0 -- - git-proto-request = request-command SP pathname NUL [ host-parameter NUL ] + git-proto-request = request-command SP pathname NUL + [ host-parameter NUL ] [ NUL extra-parameters ] request-command = "git-upload-pack" / "git-receive-pack" / "git-upload-archive" ; case sensitive pathname = *( %x01-ff ) ; exclude NUL host-parameter = "host=" hostname [ ":" port ] + extra-parameters = 1*extra-parameter + extra-parameter = 1*( %x01-ff ) NUL -- -Only host-parameter is allowed in the git-proto-request. Clients -MUST NOT attempt to send additional parameters. It is used for the +host-parameter is used for the git-daemon name based virtual hosting. See --interpolated-path option to git daemon, with the %H/%CH format characters. @@ -117,6 +137,12 @@ we execute it without the leading '/'. v ssh user@example.com "git-upload-pack '~alice/project.git'" +Depending on the value of the `protocol.version` configuration variable, +Git may attempt to send Extra Parameters as a colon-separated string in +the GIT_PROTOCOL environment variable. This is done only if +the `ssh.variant` configuration variable indicates that the ssh command +supports passing environment variables as an argument. + A few things to remember here: - The "command name" is spelled with dash (e.g. git-upload-pack), but @@ -137,11 +163,13 @@ Reference Discovery ------------------- When the client initially connects the server will immediately respond -with a listing of each reference it has (all branches and tags) along +with a version number (if "version=1" is sent as an Extra Parameter), +and a listing of each reference it has (all branches and tags) along with the object name that each reference currently points to. - $ echo -e -n "0039git-upload-pack /schacon/gitbook.git\0host=example.com\0" | + $ echo -e -n "0044git-upload-pack /schacon/gitbook.git\0host=example.com\0\0version=1\0" | nc -v example.com 9418 + 000aversion 1 00887217a7c7e582c46cec22a130adf4b9d7d950fba0 HEAD\0multi_ack thin-pack side-band side-band-64k ofs-delta shallow no-progress include-tag 00441d3fcd5ced445d1abc402225c0b8a1299641f497 refs/heads/integration @@ -165,7 +193,8 @@ immediately after the ref itself, if presented. A conforming server MUST peel the ref if it's an annotated tag. ---- - advertised-refs = (no-refs / list-of-refs) + advertised-refs = *1("version 1") + (no-refs / list-of-refs) *shallow flush-pkt @@ -199,7 +228,7 @@ After reference and capabilities discovery, the client can decide to terminate the connection by sending a flush-pkt, telling the server it can now gracefully terminate, and disconnect, when it does not need any pack data. This can happen with the ls-remote command, and also can happen when -the client already is up-to-date. +the client already is up to date. Otherwise, it enters the negotiation phase, where the client and server determine what the minimal packfile necessary for transport is, @@ -351,14 +380,19 @@ ACK after 'done' if there is at least one common base and multi_ack or multi_ack_detailed is enabled. The server always sends NAK after 'done' if there is no common base found. +Instead of 'ACK' or 'NAK', the server may send an error message (for +example, if it does not recognize an object in a 'want' line received +from the client). + Then the server will start sending its packfile data. ---- - server-response = *ack_multi ack / nak + server-response = *ack_multi ack / nak / error-line ack_multi = PKT-LINE("ACK" SP obj-id ack_status) ack_status = "continue" / "common" / "ready" ack = PKT-LINE("ACK" SP obj-id) nak = PKT-LINE("NAK") + error-line = PKT-LINE("ERR" SP explanation-text) ---- A simple clone may look like this (with no 'have' lines): @@ -468,13 +502,10 @@ that it wants to update, it sends a line listing the obj-id currently on the server, the obj-id the client would like to update it to and the name of the reference. -This list is followed by a flush-pkt. Then the push options are transmitted -one per packet followed by another flush-pkt. After that the packfile that -should contain all the objects that the server will need to complete the new -references will be sent. +This list is followed by a flush-pkt. ---- - update-request = *shallow ( command-list | push-cert ) [packfile] + update-requests = *shallow ( command-list | push-cert ) shallow = PKT-LINE("shallow" SP obj-id) @@ -495,12 +526,35 @@ references will be sent. PKT-LINE("pusher" SP ident LF) PKT-LINE("pushee" SP url LF) PKT-LINE("nonce" SP nonce LF) + *PKT-LINE("push-option" SP push-option LF) PKT-LINE(LF) *PKT-LINE(command LF) *PKT-LINE(gpg-signature-lines LF) PKT-LINE("push-cert-end" LF) - packfile = "PACK" 28*(OCTET) + push-option = 1*( VCHAR | SP ) +---- + +If the server has advertised the 'push-options' capability and the client has +specified 'push-options' as part of the capability list above, the client then +sends its push options followed by a flush-pkt. + +---- + push-options = *PKT-LINE(push-option) flush-pkt +---- + +For backwards compatibility with older Git servers, if the client sends a push +cert and push options, it MUST send its push options both embedded within the +push cert and after the push cert. (Note that the push options within the cert +are prefixed, but the push options after the cert are not.) Both these lists +MUST be the same, modulo the prefix. + +After that the packfile that +should contain all the objects that the server will need to complete the new +references will be sent. + +---- + packfile = "PACK" 28*(OCTET) ---- If the receiving end does not support delete-refs, the sending end MUST |