diff options
| -rw-r--r-- | Documentation/config.txt | 17 | ||||
| -rw-r--r-- | Documentation/git.txt | 6 | ||||
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | cache.h | 8 | ||||
| -rw-r--r-- | protocol.c | 79 | ||||
| -rw-r--r-- | protocol.h | 33 |
6 files changed, 144 insertions, 0 deletions
diff --git a/Documentation/config.txt b/Documentation/config.txt index dc4e3f58a2..b78747abc6 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 6e3a6767e5..7518ea3af2 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]] ------------------------ @@ -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 @@ -446,6 +446,14 @@ static inline enum object_type object_type(unsigned int mode) #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 0000000000..43012b7eb6 --- /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 0000000000..1b2bc94a8d --- /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 */ |