As some issues that can happen with a Git client can be operating system
specific, it can be useful for a server to know which OS a client is
using. In the same way it can be useful for a client to know which OS
a server is using.
Our current agent capability is in the form of "package/version" (e.g.,
"git/1.8.3.1"). Let's extend it to include the operating system name (os)
i.e in the form "package/version-os" (e.g., "git/1.8.3.1-Linux").
Including OS details in the agent capability simplifies implementation,
maintains backward compatibility, avoids introducing a new capability,
encourages adoption across Git-compatible software, and enhances
debugging by providing complete environment information without affecting
functionality. The operating system name is retrieved using the 'sysname'
field of the `uname(2)` system call or its equivalent.
However, there are differences between `uname(1)` (command-line utility)
and `uname(2)` (system call) outputs on Windows. These discrepancies
complicate testing on Windows platforms. For example:
- `uname(1)` output: MINGW64_NT-10.0-20348.3.4.10-87d57229.x86_64\
.2024-02-14.20:17.UTC.x86_64
- `uname(2)` output: Windows.10.0.20348
On Windows, uname(2) is not actually system-supplied but is instead
already faked up by Git itself. We could have overcome the test issue
on Windows by implementing a new `uname` subcommand in `test-tool`
using uname(2), but except uname(2), which would be tested against
itself, there would be nothing platform specific, so it's just simpler
to disable the tests on Windows.
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Usman Akinyemi <usmanakinyemi202@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Usman Akinyemi committedFeb 15, 2025 at 21:20 UTCcf7ee481902df64b26ac8b1741eca861a8d2f7cc
6 files changed+62-6
Documentation/gitprotocol-v2.txt
+7-3
index 1652fef3ae..9f6350bbf2 100644--- a/Documentation/gitprotocol-v2.txt+++ b/Documentation/gitprotocol-v2.txt@@ -184,9 +184,13 @@ form `agent=X`) to notify the client that the server is running version the `agent` capability with a value `Y` (in the form `agent=Y`) in its request to the server (but it MUST NOT do so if the server did not advertise the agent capability). The `X` and `Y` strings may contain any-printable ASCII characters except space (i.e., the byte range 32 < x <-127), and are typically of the form "package/version" (e.g.,-"git/1.8.3.1"). The agent strings are purely informative for statistics+printable ASCII characters except space (i.e., the byte range 33 <= x <=+126), and are typically of the form "package/version-os" (e.g.,+"git/1.8.3.1-Linux") where `os` is the operating system name (e.g.,+"Linux"). `X` and `Y` can be configured using the GIT_USER_AGENT+environment variable and it takes priority. The `os` is+retrieved using the 'sysname' field of the `uname(2)` system call+or its equivalent. The agent strings are purely informative for statistics and debugging purposes, and MUST NOT be used to programmatically assume the presence or absence of particular features.
connect.c
+1-1
index 10fad43e98..4d85479075 100644--- a/connect.c+++ b/connect.c@@ -625,7 +625,7 @@ const char *parse_feature_value(const char *feature_list, const char *feature, s *offset = found + len - orig_start; return value; }- /* feature with a value (e.g., "agent=git/1.2.3") */+ /* feature with a value (e.g., "agent=git/1.2.3-Linux") */ else if (*value == '=') { size_t end;
index 78e054ab50..3465904323 100644--- a/t/test-lib-functions.sh+++ b/t/test-lib-functions.sh@@ -2007,3 +2007,11 @@ test_trailing_hash () { test-tool hexdump | sed "s/ //g" }++# Trim and replace each character with ascii code below 32 or above+# 127 (included) using a dot '.' character.+# Octal intervals \001-\040 and \177-\377+# correspond to decimal intervals 1-32 and 127-255+test_redact_non_printables () {+ tr -d "\n\r" | tr "[\001-\040][\177-\377]" "."+}
version.c
+28-1
index d95221a72a..8e927cf1eb 100644--- a/version.c+++ b/version.c@@ -1,8 +1,9 @@+#define USE_THE_REPOSITORY_VARIABLE+ #include "git-compat-util.h" #include "version.h" #include "version-def.h" #include "strbuf.h"-#include "sane-ctype.h" #include "gettext.h" const char git_version_string[] = GIT_VERSION;@@ -34,6 +35,27 @@ const char *git_user_agent(void) return agent; }+/*+ Retrieve, sanitize and cache operating system info for subsequent+ calls. Return a pointer to the sanitized operating system info+ string.+*/+static const char *os_info(void)+{+ static const char *os = NULL;++ if (!os) {+ struct strbuf buf = STRBUF_INIT;++ get_uname_info(&buf, 0);+ /* Sanitize the os information immediately */+ redact_non_printables(&buf);+ os = strbuf_detach(&buf, NULL);+ }++ return os;+}+ const char *git_user_agent_sanitized(void) { static const char *agent = NULL;@@ -42,6 +64,11 @@ const char *git_user_agent_sanitized(void) struct strbuf buf = STRBUF_INIT; strbuf_addstr(&buf, git_user_agent());++ if (!getenv("GIT_USER_AGENT")) {+ strbuf_addch(&buf, '-');+ strbuf_addstr(&buf, os_info());+ } redact_non_printables(&buf); agent = strbuf_detach(&buf, NULL); }