From 9dab78b5822d59a13e767ef20fdffab46f79cb25 Mon Sep 17 00:00:00 2001
From: Joel Colledge <joel.colledge@linbit.com>
Date: Thu, 21 Nov 2024 09:55:26 +0100
Subject: [PATCH 08/12] drbdadm: add proxy options to 'add connection' command

Some options such as rcvbuf-size must be set before attempting to
connect. Proxy v3 used ugly hacks to allow time for the options to
arrive before connecting. Proxy v4 does not use this approach. Instead
it requires the options to be set on the command line for 'add
connection'.

The additional options are ignored by Proxy v3 with a "trailing garbage"
warning.

We continue to set the properties using 'set' commands as well to retain
compatibility with Proxy v3. Proxy v4 ignores 'set' commands which do
not change the value of the option.

So this is compatible with Proxy v3 and v4.
---
 user/v9/drbdadm_main.c | 38 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/user/v9/drbdadm_main.c b/user/v9/drbdadm_main.c
index 74cf60365a6d..a983a9463fb8 100644
--- a/user/v9/drbdadm_main.c
+++ b/user/v9/drbdadm_main.c
@@ -2043,19 +2043,33 @@ char *_proxy_connection_name(char *conn_name, const struct d_resource *res, cons
 	return conn_name;
 }
 
+#define ADD_CONNECTION_MAX_LEN 4096
+
 static int do_proxy_conn_up(const struct cfg_ctx *ctx)
 {
 	const char *argv[4] = { drbd_proxy_ctl, "-c", NULL, NULL };
 	struct connection *conn = ctx->conn;
 	struct path *path = STAILQ_FIRST(&conn->paths); /* multiple paths via proxy, later! */
 	char *conn_name;
+	char *buffer;
+	char *buffer_pos;
+	int buffer_remaining;
+	int n;
+	struct d_option *opt;
+	int rv = -1;
 
 	if (!path->my_proxy || !path->peer_proxy)
 		return 0;
 
 	conn_name = proxy_connection_name(ctx->res, conn);
 
-	argv[2] = ssprintf(
+	buffer_remaining = ADD_CONNECTION_MAX_LEN;
+	buffer = checked_malloc(buffer_remaining);
+	buffer_pos = buffer;
+
+	n = snprintf(
+		buffer_pos,
+		buffer_remaining,
 		"add connection %s %s:%s %s:%s %s:%s %s:%s",
 		conn_name,
 		path->my_proxy->inside.addr,
@@ -2066,8 +2080,28 @@ static int do_proxy_conn_up(const struct cfg_ctx *ctx)
 		path->my_proxy->outside.port,
 		path->my_address->addr,
 		path->my_address->port);
+	if (n < 0 || n >= buffer_remaining)
+		goto out;
+	buffer_pos += n;
+	buffer_remaining -= n;
 
-	return m_system_ex(argv, SLEEPS_SHORT, ctx->res->name);
+	STAILQ_FOREACH(opt, &path->my_proxy->options, link) {
+		n = snprintf(
+			buffer_pos,
+			buffer_remaining,
+			" --%s=%s",
+			opt->name, opt->value);
+		if (n < 0 || n >= buffer_remaining)
+			goto out;
+		buffer_pos += n;
+		buffer_remaining -= n;
+	}
+
+	argv[2] = buffer;
+	rv = m_system_ex(argv, SLEEPS_SHORT, ctx->res->name);
+out:
+	free(buffer);
+	return rv;
 }
 
 static int do_proxy_conn_plugins(const struct cfg_ctx *ctx)
-- 
2.43.0