From 3ad0a3d223411c49db59c412c0b107df8579b39c Mon Sep 17 00:00:00 2001
From: Andy Green <andy@warmcat.com>
Date: Sat, 3 Apr 2021 19:29:02 +0100
Subject: [PATCH] ss: server: allow bind to existing vhost

If the larger application is defining vhosts using lejp-conf JSON, it's
often more convenient to describe the vhost for ss server binding to
that.

If the server policy endpoint (usually used to describe the server
interface bind) begins with '!', take the remainder of the endpoint
string as the name of a preexisting vhost to bind ss server to at
creation-time.
---
 lib/secure-streams/README.md        |  5 +++++
 lib/secure-streams/secure-streams.c | 29 +++++++++++++++++++++++++----
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/lib/secure-streams/README.md b/lib/secure-streams/README.md
index de44106b8..ffad3e7b2 100644
--- a/lib/secure-streams/README.md
+++ b/lib/secure-streams/README.md
@@ -274,6 +274,11 @@ configured with `-DLWS_UNIX_SOCK=1`
 **SERVER**: If given, the network interface name or IP address the listen socket
 should bind to.
 
+**SERVER**: If begins with '!', the rest of the endpoint name is the
+vhost name of an existing vhost to bind to, instead of creating a new
+one.  This is useful when the vhost layout is already being managed by
+lejp-conf JSON and it's more convenient to put the details in there.
+
 ### `port`
 
 **CLIENT**: The port number as an integer on the endpoint to connect to
diff --git a/lib/secure-streams/secure-streams.c b/lib/secure-streams/secure-streams.c
index dd335c579..86c187dd2 100644
--- a/lib/secure-streams/secure-streams.c
+++ b/lib/secure-streams/secure-streams.c
@@ -1048,10 +1048,30 @@ lws_ss_create(struct lws_context *context, int tsi, const lws_ss_info_t *ssi,
 	if (h->policy->flags & LWSSSPOLF_SERVER) {
 		const struct lws_protocols *pprot[3], **ppp = &pprot[0];
 		struct lws_context_creation_info i;
-		struct lws_vhost *vho;
+		struct lws_vhost *vho = NULL;
 
 		lwsl_info("%s: creating server\n", __func__);
 
+		if (h->policy->endpoint &&
+		    h->policy->endpoint[0] == '!') {
+			/*
+			 * There's already a vhost existing that we want to
+			 * bind to, we don't have to specify and create one.
+			 *
+			 * The vhost must enable any protocols that we want.
+			 */
+
+			vho = lws_get_vhost_by_name(context,
+						    &h->policy->endpoint[1]);
+			if (!vho) {
+				lwsl_err("%s: no vhost %s\n", __func__,
+						&h->policy->endpoint[1]);
+				goto late_bail;
+			}
+
+			goto extant;
+		}
+
 		/*
 		 * This streamtype represents a server, we're being asked to
 		 * instantiate a corresponding vhost for it
@@ -1099,15 +1119,16 @@ lws_ss_create(struct lws_context *context, int tsi, const lws_ss_info_t *ssi,
 		}
 #endif
 
-		if (lws_fi(&ssi->fic, "ss_srv_vh_fail"))
-			vho = NULL;
-		else
+
+		if (!lws_fi(&ssi->fic, "ss_srv_vh_fail"))
 			vho = lws_create_vhost(context, &i);
 		if (!vho) {
 			lwsl_err("%s: failed to create vh", __func__);
 			goto late_bail;
 		}
 
+extant:
+
 		/*
 		 * Mark this vhost as having to apply ss server semantics to
 		 * any incoming accepted connection