Re: [PATCH v2 4/9] daemon: recognize hidden request arguments

On 09/27, Junio C Hamano wrote:

Brandon Williams [off-list ref] writes:

quoted

A normal request to git-daemon is structured as
"command path/to/repo\0host=..\0" and due to a bug in an old version of
git-daemon 73bb33a94 (daemon: Strictly parse the "extra arg" part of the
command, 2009-06-04) we aren't able to place any extra args (separated
by NULs) besides the host.

It's a bit unclear if that commit _introduced_ a bug, or just
noticed an old bug and documented it in its log message.  How does
that commit impact the versons of Git that the updated code is
capable of interracting with?

You're right, after reading it again it isn't clear.  I'll change this
to indicate that the commit is a fix to a bug and that the fix doesn't
allow us to place any additional args.

quoted

+static void parse_extra_args(struct hostinfo *hi, struct argv_array *env,
+			     char *extra_args, int buflen)
+{
+	const char *end = extra_args + buflen;
+	struct strbuf git_protocol = STRBUF_INIT;
+
+	/* First look for the host argument */
+	extra_args = parse_host_arg(hi, extra_args, buflen);
+
+	/* Look for additional arguments places after a second NUL byte */
+	for (; extra_args < end; extra_args += strlen(extra_args) + 1) {
+		const char *arg = extra_args;
+
+		/*
+		 * Parse the extra arguments, adding most to 'git_protocol'
+		 * which will be used to set the 'GIT_PROTOCOL' envvar in the
+		 * service that will be run.
+		 *
+		 * If there ends up being a particular arg in the future that
+		 * git-daemon needs to parse specificly (like the 'host' arg)
+		 * then it can be parsed here and not added to 'git_protocol'.
+		 */
+		if (*arg) {
+			if (git_protocol.len > 0)
+				strbuf_addch(&git_protocol, ':');
+			strbuf_addstr(&git_protocol, arg);
+		}
+	}
+
+	if (git_protocol.len > 0)
+		argv_array_pushf(env, GIT_PROTOCOL_ENVIRONMENT "=%s",
+				 git_protocol.buf);
+	strbuf_release(&git_protocol);
 }

-- 
Brandon Williams