From: Brandon Williams <bmwill@google.com>
To: git@vger.kernel.org
Cc: bturner@atlassian.com, git@jeffhostetler.com, gitster@pobox.com,
jonathantanmy@google.com, jrnieder@gmail.com, peff@peff.net,
sbeller@google.com, Brandon Williams <bmwill@google.com>
Subject: [PATCH v3 03/10] protocol: introduce protocol extention mechanisms
Date: Tue, 3 Oct 2017 13:15:00 -0700 [thread overview]
Message-ID: <20171003201507.3589-4-bmwill@google.com> (raw)
In-Reply-To: <20171003201507.3589-1-bmwill@google.com>
Create protocol.{c,h} and provide functions which future servers and
clients can use to determine which protocol to use or is being used.
Also introduce the 'GIT_PROTOCOL' environment variable which will be
used to communicate a colon separated list of keys with optional values
to a server. Unknown keys and values must be tolerated. This mechanism
is used to communicate which version of the wire protocol a client would
like to use with a server.
Signed-off-by: Brandon Williams <bmwill@google.com>
---
Documentation/config.txt | 17 +++++++++++
Documentation/git.txt | 6 ++++
Makefile | 1 +
cache.h | 8 +++++
protocol.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++
protocol.h | 33 ++++++++++++++++++++
6 files changed, 144 insertions(+)
create mode 100644 protocol.c
create mode 100644 protocol.h
diff --git a/Documentation/config.txt b/Documentation/config.txt
index dc4e3f58a..b78747abc 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -2517,6 +2517,23 @@ The protocol names currently used by git are:
`hg` to allow the `git-remote-hg` helper)
--
+protocol.version::
+ Experimental. If set, clients will attempt to communicate with a
+ server using the specified protocol version. If unset, no
+ attempt will be made by the client to communicate using a
+ particular protocol version, this results in protocol version 0
+ being used.
+ Supported versions:
++
+--
+
+* `0` - the original wire protocol.
+
+* `1` - the original wire protocol with the addition of a version string
+ in the initial response from the server.
+
+--
+
pull.ff::
By default, Git does not create an extra merge commit when merging
a commit that is a descendant of the current commit. Instead, the
diff --git a/Documentation/git.txt b/Documentation/git.txt
index 6e3a6767e..7518ea3af 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -697,6 +697,12 @@ of clones and fetches.
which feed potentially-untrusted URLS to git commands. See
linkgit:git-config[1] for more details.
+`GIT_PROTOCOL`::
+ For internal use only. Used in handshaking the wire protocol.
+ Contains a colon ':' separated list of keys with optional values
+ 'key[=value]'. Presence of unknown keys and values must be
+ ignored.
+
Discussion[[Discussion]]
------------------------
diff --git a/Makefile b/Makefile
index ed4ca438b..9ce68cded 100644
--- a/Makefile
+++ b/Makefile
@@ -842,6 +842,7 @@ LIB_OBJS += pretty.o
LIB_OBJS += prio-queue.o
LIB_OBJS += progress.o
LIB_OBJS += prompt.o
+LIB_OBJS += protocol.o
LIB_OBJS += quote.o
LIB_OBJS += reachable.o
LIB_OBJS += read-cache.o
diff --git a/cache.h b/cache.h
index 49b083ee0..c74b73671 100644
--- a/cache.h
+++ b/cache.h
@@ -445,6 +445,14 @@ static inline enum object_type object_type(unsigned int mode)
#define GIT_ICASE_PATHSPECS_ENVIRONMENT "GIT_ICASE_PATHSPECS"
#define GIT_QUARANTINE_ENVIRONMENT "GIT_QUARANTINE_PATH"
+/*
+ * Environment variable used in handshaking the wire protocol.
+ * Contains a colon ':' separated list of keys with optional values
+ * 'key[=value]'. Presence of unknown keys and values must be
+ * ignored.
+ */
+#define GIT_PROTOCOL_ENVIRONMENT "GIT_PROTOCOL"
+
/*
* This environment variable is expected to contain a boolean indicating
* whether we should or should not treat:
diff --git a/protocol.c b/protocol.c
new file mode 100644
index 000000000..43012b7eb
--- /dev/null
+++ b/protocol.c
@@ -0,0 +1,79 @@
+#include "cache.h"
+#include "config.h"
+#include "protocol.h"
+
+static enum protocol_version parse_protocol_version(const char *value)
+{
+ if (!strcmp(value, "0"))
+ return protocol_v0;
+ else if (!strcmp(value, "1"))
+ return protocol_v1;
+ else
+ return protocol_unknown_version;
+}
+
+enum protocol_version get_protocol_version_config(void)
+{
+ const char *value;
+ if (!git_config_get_string_const("protocol.version", &value)) {
+ enum protocol_version version = parse_protocol_version(value);
+
+ if (version == protocol_unknown_version)
+ die("unknown value for config 'protocol.version': %s",
+ value);
+
+ return version;
+ }
+
+ return protocol_v0;
+}
+
+enum protocol_version determine_protocol_version_server(void)
+{
+ const char *git_protocol = getenv(GIT_PROTOCOL_ENVIRONMENT);
+ enum protocol_version version = protocol_v0;
+
+ /*
+ * Determine which protocol version the client has requested. Since
+ * multiple 'version' keys can be sent by the client, indicating that
+ * the client is okay to speak any of them, select the greatest version
+ * that the client has requested. This is due to the assumption that
+ * the most recent protocol version will be the most state-of-the-art.
+ */
+ if (git_protocol) {
+ struct string_list list = STRING_LIST_INIT_DUP;
+ const struct string_list_item *item;
+ string_list_split(&list, git_protocol, ':', -1);
+
+ for_each_string_list_item(item, &list) {
+ const char *value;
+ enum protocol_version v;
+
+ if (skip_prefix(item->string, "version=", &value)) {
+ v = parse_protocol_version(value);
+ if (v > version)
+ version = v;
+ }
+ }
+
+ string_list_clear(&list, 0);
+ }
+
+ return version;
+}
+
+enum protocol_version determine_protocol_version_client(const char *server_response)
+{
+ enum protocol_version version = protocol_v0;
+
+ if (skip_prefix(server_response, "version ", &server_response)) {
+ version = parse_protocol_version(server_response);
+
+ if (version == protocol_unknown_version)
+ die("server is speaking an unknown protocol");
+ if (version == protocol_v0)
+ die("protocol error: server explicitly said version 0");
+ }
+
+ return version;
+}
diff --git a/protocol.h b/protocol.h
new file mode 100644
index 000000000..1b2bc94a8
--- /dev/null
+++ b/protocol.h
@@ -0,0 +1,33 @@
+#ifndef PROTOCOL_H
+#define PROTOCOL_H
+
+enum protocol_version {
+ protocol_unknown_version = -1,
+ protocol_v0 = 0,
+ protocol_v1 = 1,
+};
+
+/*
+ * Used by a client to determine which protocol version to request be used when
+ * communicating with a server, reflecting the configured value of the
+ * 'protocol.version' config. If unconfigured, a value of 'protocol_v0' is
+ * returned.
+ */
+extern enum protocol_version get_protocol_version_config(void);
+
+/*
+ * Used by a server to determine which protocol version should be used based on
+ * a client's request, communicated via the 'GIT_PROTOCOL' environment variable
+ * by setting appropriate values for the key 'version'. If a client doesn't
+ * request a particular protocol version, a default of 'protocol_v0' will be
+ * used.
+ */
+extern enum protocol_version determine_protocol_version_server(void);
+
+/*
+ * Used by a client to determine which protocol version the server is speaking
+ * based on the server's initial response.
+ */
+extern enum protocol_version determine_protocol_version_client(const char *server_response);
+
+#endif /* PROTOCOL_H */
--
2.14.2.920.gcf0c67979c-goog
next prev parent reply other threads:[~2017-10-03 20:15 UTC|newest]
Thread overview: 161+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-13 21:54 [PATCH 0/8] protocol transition Brandon Williams
2017-09-13 21:54 ` [PATCH 1/8] pkt-line: add packet_write function Brandon Williams
2017-09-13 21:54 ` [PATCH 2/8] protocol: introduce protocol extention mechanisms Brandon Williams
2017-09-13 22:27 ` Stefan Beller
2017-09-18 17:02 ` Brandon Williams
2017-09-18 18:34 ` Stefan Beller
2017-09-18 19:58 ` Brandon Williams
2017-09-18 20:06 ` Stefan Beller
2017-09-13 21:54 ` [PATCH 3/8] daemon: recognize hidden request arguments Brandon Williams
2017-09-13 22:31 ` Stefan Beller
2017-09-18 16:56 ` Brandon Williams
2017-09-21 0:24 ` Jonathan Tan
2017-09-21 0:31 ` Jonathan Tan
2017-09-21 21:55 ` Brandon Williams
2017-09-13 21:54 ` [PATCH 4/8] upload-pack, receive-pack: introduce protocol version 1 Brandon Williams
2017-09-13 21:54 ` [PATCH 5/8] connect: teach client to recognize v1 server response Brandon Williams
2017-09-13 21:54 ` [PATCH 6/8] connect: tell server that the client understands v1 Brandon Williams
2017-09-13 21:54 ` [PATCH 7/8] http: " Brandon Williams
2017-09-13 21:54 ` [PATCH 8/8] i5700: add interop test for protocol transition Brandon Williams
2017-09-20 18:48 ` [PATCH 1.5/8] connect: die when a capability line comes after a ref Brandon Williams
2017-09-20 19:14 ` Jeff King
2017-09-20 20:06 ` Brandon Williams
2017-09-20 20:48 ` Jonathan Nieder
2017-09-21 3:02 ` Junio C Hamano
2017-09-21 20:45 ` [PATCH] connect: in ref advertisement, shallows are last Jonathan Tan
2017-09-21 23:45 ` [PATCH v2] " Jonathan Tan
2017-09-22 0:00 ` Brandon Williams
2017-09-22 0:08 ` [PATCH v3] " Jonathan Tan
2017-09-22 1:06 ` Junio C Hamano
2017-09-22 1:39 ` Junio C Hamano
2017-09-22 16:45 ` Brandon Williams
2017-09-22 20:15 ` [PATCH v4] " Jonathan Tan
2017-09-22 21:01 ` Brandon Williams
2017-09-22 22:16 ` Jonathan Tan
2017-09-24 0:52 ` Junio C Hamano
2017-09-26 18:21 ` [PATCH v5] " Jonathan Tan
2017-09-26 18:31 ` Brandon Williams
2017-09-26 23:56 ` [PATCH v2 0/9] protocol transition Brandon Williams
2017-09-26 23:56 ` [PATCH v2 1/9] connect: in ref advertisement, shallows are last Brandon Williams
2017-09-26 23:56 ` [PATCH v2 2/9] pkt-line: add packet_write function Brandon Williams
2017-09-26 23:56 ` [PATCH v2 3/9] protocol: introduce protocol extention mechanisms Brandon Williams
2017-09-27 5:17 ` Junio C Hamano
2017-09-27 11:23 ` Junio C Hamano
2017-09-29 21:20 ` Brandon Williams
2017-09-28 21:58 ` Brandon Williams
2017-09-27 6:30 ` Stefan Beller
2017-09-28 21:04 ` Brandon Williams
2017-09-26 23:56 ` [PATCH v2 4/9] daemon: recognize hidden request arguments Brandon Williams
2017-09-27 5:20 ` Junio C Hamano
2017-09-27 21:22 ` Brandon Williams
2017-09-28 16:57 ` Brandon Williams
2017-09-26 23:56 ` [PATCH v2 5/9] upload-pack, receive-pack: introduce protocol version 1 Brandon Williams
2017-09-27 5:23 ` Junio C Hamano
2017-09-27 21:29 ` Brandon Williams
2017-09-26 23:56 ` [PATCH v2 6/9] connect: teach client to recognize v1 server response Brandon Williams
2017-09-27 1:07 ` Junio C Hamano
2017-09-27 17:34 ` Brandon Williams
2017-09-27 5:29 ` Junio C Hamano
2017-09-28 22:08 ` Brandon Williams
2017-09-26 23:56 ` [PATCH v2 7/9] connect: tell server that the client understands v1 Brandon Williams
2017-09-27 6:21 ` Junio C Hamano
2017-09-27 6:29 ` Junio C Hamano
2017-09-29 21:32 ` Brandon Williams
2017-09-28 22:20 ` Brandon Williams
2017-09-26 23:56 ` [PATCH v2 8/9] http: " Brandon Williams
2017-09-27 6:24 ` Junio C Hamano
2017-09-27 21:36 ` Brandon Williams
2017-09-26 23:56 ` [PATCH v2 9/9] i5700: add interop test for protocol transition Brandon Williams
2017-10-03 20:14 ` [PATCH v3 00/10] " Brandon Williams
2017-10-03 20:14 ` [PATCH v3 01/10] connect: in ref advertisement, shallows are last Brandon Williams
2017-10-10 18:14 ` Jonathan Tan
2017-10-03 20:14 ` [PATCH v3 02/10] pkt-line: add packet_write function Brandon Williams
2017-10-10 18:15 ` Jonathan Tan
2017-10-03 20:15 ` Brandon Williams [this message]
2017-10-06 9:09 ` [PATCH v3 03/10] protocol: introduce protocol extention mechanisms Simon Ruderich
2017-10-06 9:40 ` Junio C Hamano
2017-10-06 11:11 ` Martin Ågren
2017-10-06 12:09 ` Junio C Hamano
2017-10-06 19:42 ` Martin Ågren
2017-10-06 20:27 ` Stefan Beller
2017-10-08 14:24 ` Martin Ågren
2017-10-10 21:00 ` Brandon Williams
2017-10-10 21:17 ` Jonathan Nieder
2017-10-10 21:32 ` Stefan Beller
2017-10-11 0:39 ` Junio C Hamano
2017-10-13 22:46 ` Brandon Williams
2017-10-09 4:05 ` Martin Ågren
2017-10-10 19:51 ` Jonathan Tan
2017-10-03 20:15 ` [PATCH v3 04/10] daemon: recognize hidden request arguments Brandon Williams
2017-10-10 18:24 ` Jonathan Tan
2017-10-13 22:04 ` Brandon Williams
2017-10-03 20:15 ` [PATCH v3 05/10] upload-pack, receive-pack: introduce protocol version 1 Brandon Williams
2017-10-10 18:28 ` Jonathan Tan
2017-10-13 22:18 ` Brandon Williams
2017-10-03 20:15 ` [PATCH v3 06/10] connect: teach client to recognize v1 server response Brandon Williams
2017-10-03 20:15 ` [PATCH v3 07/10] connect: tell server that the client understands v1 Brandon Williams
2017-10-10 18:30 ` Jonathan Tan
2017-10-13 22:56 ` Brandon Williams
2017-10-03 20:15 ` [PATCH v3 08/10] http: " Brandon Williams
2017-10-03 20:15 ` [PATCH v3 09/10] i5700: add interop test for protocol transition Brandon Williams
2017-10-03 20:15 ` [PATCH v3 10/10] ssh: introduce a 'simple' ssh variant Brandon Williams
2017-10-03 21:42 ` Jonathan Nieder
2017-10-16 17:18 ` Brandon Williams
2017-10-23 21:28 ` [PATCH 0/5] Coping with unrecognized ssh wrapper scripts in GIT_SSH Jonathan Nieder
2017-10-23 21:29 ` [PATCH 1/5] connect: split git:// setup into a separate function Jonathan Nieder
2017-10-23 22:16 ` Stefan Beller
2017-10-24 0:09 ` [WIP PATCH] diff: add option to ignore whitespaces for move detection only Stefan Beller
2017-10-24 18:48 ` Brandon Williams
2017-10-25 1:25 ` Junio C Hamano
2017-10-25 1:26 ` Junio C Hamano
2017-10-25 18:58 ` Brandon Williams
2017-10-24 1:54 ` [PATCH 1/5] connect: split git:// setup into a separate function Junio C Hamano
2017-10-24 2:52 ` Stefan Beller
2017-10-23 21:30 ` [PATCH 2/5] connect: split ssh command line options into " Jonathan Nieder
2017-10-23 21:48 ` Stefan Beller
2017-10-23 21:31 ` [PATCH 3/5] ssh: 'auto' variant to select between 'ssh' and 'simple' Jonathan Nieder
2017-10-23 22:19 ` Jonathan Tan
2017-10-23 22:43 ` Jonathan Nieder
2017-10-23 22:51 ` Brandon Williams
2017-10-23 22:57 ` Jonathan Tan
2017-10-23 23:16 ` [PATCH v2 0/5] Coping with unrecognized ssh wrapper scripts in GIT_SSH Jonathan Nieder
2017-10-23 23:17 ` [PATCH 1/5] connect: split git:// setup into a separate function Jonathan Nieder
2017-10-24 1:44 ` Junio C Hamano
2017-11-15 20:25 ` Jonathan Nieder
2017-11-17 1:12 ` Junio C Hamano
2017-10-23 23:17 ` [PATCH 2/5] connect: split ssh command line options into " Jonathan Nieder
2017-10-24 2:01 ` Junio C Hamano
2017-10-23 23:18 ` [PATCH 3/5] ssh: 'auto' variant to select between 'ssh' and 'simple' Jonathan Nieder
2017-10-23 23:27 ` Brandon Williams
2017-10-23 23:33 ` Stefan Beller
2017-10-23 23:19 ` [PATCH 4/5] ssh: 'simple' variant does not support -4/-6 Jonathan Nieder
2017-10-23 23:19 ` [PATCH 5/5] ssh: 'simple' variant does not support --port Jonathan Nieder
2017-10-24 2:22 ` [PATCH v2 0/5] Coping with unrecognized ssh wrapper scripts in GIT_SSH Junio C Hamano
2017-10-23 23:12 ` [PATCH 3/5] ssh: 'auto' variant to select between 'ssh' and 'simple' Jonathan Nieder
2017-10-23 22:33 ` Stefan Beller
2017-10-23 22:54 ` Jonathan Nieder
2017-10-24 2:16 ` Junio C Hamano
2017-10-25 12:51 ` Johannes Schindelin
2017-10-25 16:18 ` Stefan Beller
2017-10-25 16:32 ` Jonathan Nieder
2017-10-30 0:40 ` Junio C Hamano
2017-10-30 12:37 ` Johannes Schindelin
2017-10-23 21:32 ` [PATCH 4/5] ssh: 'simple' variant does not support -4/-6 Jonathan Nieder
2017-10-23 21:33 ` [PATCH 5/5] ssh: 'simple' variant does not support --port Jonathan Nieder
2017-10-23 22:37 ` Stefan Beller
2017-10-04 6:20 ` [PATCH v3 00/10] protocol transition Junio C Hamano
2017-10-10 19:39 ` [PATCH] Documentation: document Extra Parameters Jonathan Tan
2017-10-13 22:26 ` Brandon Williams
2017-10-16 17:55 ` [PATCH v4 00/11] protocol transition Brandon Williams
2017-10-16 17:55 ` [PATCH v4 01/11] connect: in ref advertisement, shallows are last Brandon Williams
2017-10-16 17:55 ` [PATCH v4 02/11] pkt-line: add packet_write function Brandon Williams
2017-10-16 17:55 ` [PATCH v4 03/11] protocol: introduce protocol extension mechanisms Brandon Williams
2017-10-16 21:25 ` Kevin Daudt
2017-10-16 17:55 ` [PATCH v4 04/11] daemon: recognize hidden request arguments Brandon Williams
2017-10-16 17:55 ` [PATCH v4 05/11] upload-pack, receive-pack: introduce protocol version 1 Brandon Williams
2017-10-16 17:55 ` [PATCH v4 06/11] connect: teach client to recognize v1 server response Brandon Williams
2017-10-16 17:55 ` [PATCH v4 07/11] connect: tell server that the client understands v1 Brandon Williams
2017-10-16 17:55 ` [PATCH v4 08/11] http: " Brandon Williams
2017-10-16 17:55 ` [PATCH v4 09/11] i5700: add interop test for protocol transition Brandon Williams
2017-10-16 17:55 ` [PATCH v4 10/11] ssh: introduce a 'simple' ssh variant Brandon Williams
2017-10-16 17:55 ` [PATCH v4 11/11] Documentation: document Extra Parameters Brandon Williams
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