From b0fe8ce6f1f0add1fcea24946363a787c1c8c09a Mon Sep 17 00:00:00 2001
From: Tomas Krizek <tomas.krizek@nic.cz>
Date: Thu, 8 Apr 2021 12:57:33 +0200
Subject: [PATCH] daemon/worker: add doh_headers_in list

---
 daemon/bindings/net.c | 50 +++++++++++++++++++++++++++++++++++++++++++
 daemon/worker.c       |  6 ++++++
 daemon/worker.h       |  6 ++++++
 3 files changed, 62 insertions(+)

diff --git a/daemon/bindings/net.c b/daemon/bindings/net.c
index 37ae24001..d41578d4f 100644
--- a/daemon/bindings/net.c
+++ b/daemon/bindings/net.c
@@ -435,6 +435,55 @@ static int net_tls(lua_State *L)
 	return 1;
 }
 
+/** Select HTTP headers to subscribe to for incoming DoH requests. */
+static int net_doh_headers_in(lua_State *L)
+{
+	doh_headerlist_t *headers = &the_worker->doh_headers_in;
+	int i;
+	const char *name;
+
+	/* Only return current configuration. */
+	if (lua_gettop(L) == 0) {
+		lua_newtable(L);
+		for (i = 0; i < headers->len; i++) {
+			lua_pushinteger(L, i + 1);
+			name = headers->at[i];
+			lua_pushlstring(L, name, strlen(name));
+			lua_settable(L, -3);
+		}
+		return 1;
+	}
+
+	if (lua_gettop(L) != 1)
+		lua_error_p(L, "net.doh_headers_in() takes one parameter (string or table)");
+
+	if (!lua_istable(L, 1) && !lua_isstring(L, 1))
+		lua_error_p(L, "net.doh_headers_in() argument must be string or table");
+
+	/* Clear existing headers. */
+	for (i = 0; i < headers->len; i++)
+		free(headers->at[i]);
+	array_clear(*headers);
+
+	if (lua_istable(L, 1)) {
+		for (i = 1; !lua_isnil(L, -1); i++) {
+			lua_pushinteger(L, i);
+			lua_gettable(L, 1);
+			if (lua_isnil(L, -1))  /* missing value - end iteration */
+				break;
+			if (!lua_isstring(L, -1))
+				lua_error_p(L, "net.doh_headers_in() argument table can only contain strings");
+			name = lua_tostring(L, -1);
+			array_push(*headers, strdup(name));
+		}
+	} else if (lua_isstring(L, 1)) {
+		name = lua_tostring(L, 1);
+		array_push(*headers, strdup(name));
+	}
+
+	return 0;
+}
+
 /** Return a lua table with TLS authentication parameters.
  * The format is the same as passed to policy.TLS_FORWARD();
  * more precisely, it's in a compatible canonical form. */
@@ -1083,6 +1132,7 @@ int kr_bindings_net(lua_State *L)
 		{ "bpf_set",      net_bpf_set },
 		{ "bpf_clear",    net_bpf_clear },
 		{ "register_endpoint_kind", net_register_endpoint_kind },
+		{ "doh_headers_in", net_doh_headers_in },
 		{ NULL, NULL }
 	};
 	luaL_register(L, "net", lib);
diff --git a/daemon/worker.c b/daemon/worker.c
index 586d6e303..35f82f188 100644
--- a/daemon/worker.c
+++ b/daemon/worker.c
@@ -2149,6 +2149,10 @@ void worker_deinit(void)
 	trie_free(worker->subreq_out);
 	worker->subreq_out = NULL;
 
+	for (int i = 0; i < worker->doh_headers_in.len; i++)
+		free(worker->doh_headers_in.at[i]);
+	array_clear(worker->doh_headers_in);
+
 	reclaim_mp_freelist(&worker->pool_mp);
 	mp_delete(worker->pkt_pool.ctx);
 	worker->pkt_pool.ctx = NULL;
@@ -2183,6 +2187,8 @@ int worker_init(struct engine *engine, int worker_count)
 	worker->out_addr4.sin_family = AF_UNSPEC;
 	worker->out_addr6.sin6_family = AF_UNSPEC;
 
+	array_init(worker->doh_headers_in);
+
 	int ret = worker_reserve(worker, MP_FREELIST_SIZE);
 	if (ret) return ret;
 	worker->next_request_uid = UINT16_MAX + 1;
diff --git a/daemon/worker.h b/daemon/worker.h
index 51c9099cc..26ae415cf 100644
--- a/daemon/worker.h
+++ b/daemon/worker.h
@@ -157,6 +157,9 @@ typedef array_t(struct mempool *) mp_freelist_t;
 /** List of query resolution tasks. */
 typedef array_t(struct qr_task *) qr_tasklist_t;
 
+/** List of HTTP header names. */
+typedef array_t(const char *) doh_headerlist_t;
+
 /** \details Worker state is meant to persist during the whole life of daemon. */
 struct worker_ctx {
 	struct engine *engine;
@@ -185,6 +188,9 @@ struct worker_ctx {
 	mp_freelist_t pool_mp;
 	knot_mm_t pkt_pool;
 	unsigned int next_request_uid;
+
+	/* HTTP Headers for DoH. */
+	doh_headerlist_t doh_headers_in;
 };
 
 /** @endcond */
-- 
2.47.3