Add a hook for sending default authority when needed

1 files changed, 34 insertions, 3 deletions

diff --git a/src/core/channel/http_client_filter.c b/src/core/channel/http_client_filter.c
index 6ae8488070..59a35d1e35 100644
--- a/src/core/channel/http_client_filter.c
+++ b/src/core/channel/http_client_filter.c
@@ -40,10 +40,12 @@
 typedef struct call_data {
   grpc_linked_mdelem method;
   grpc_linked_mdelem scheme;
+  grpc_linked_mdelem authority;
   grpc_linked_mdelem te_trailers;
   grpc_linked_mdelem content_type;
   grpc_linked_mdelem user_agent;
   int sent_initial_metadata;
+  int sent_authority;
 
   int got_initial_metadata;
   grpc_stream_op_buffer *recv_ops;
@@ -62,6 +64,7 @@ typedef struct channel_data {
   grpc_mdelem *scheme;
   grpc_mdelem *content_type;
   grpc_mdelem *status;
+  grpc_mdelem *default_authority;
   /** complete user agent mdelem */
   grpc_mdelem *user_agent;
 } channel_data;
@@ -100,6 +103,7 @@ static void hc_on_recv(void *user_data, int success) {
 
 static grpc_mdelem *client_strip_filter(void *user_data, grpc_mdelem *md) {
   grpc_call_element *elem = user_data;
+  call_data *calld = elem->call_data;
   channel_data *channeld = elem->channel_data;
   /* eat the things we'd like to set ourselves */
   if (md->key == channeld->method->key) return NULL;
@@ -107,6 +111,9 @@ static grpc_mdelem *client_strip_filter(void *user_data, grpc_mdelem *md) {
   if (md->key == channeld->te_trailers->key) return NULL;
   if (md->key == channeld->content_type->key) return NULL;
   if (md->key == channeld->user_agent->key) return NULL;
+  if (channeld->default_authority && channeld->default_authority->key == md->key) {
+    calld->sent_authority = 1;
+  }
   return md;
 }
 
@@ -130,6 +137,9 @@ static void hc_mutate_op(grpc_call_element *elem,
                                    GRPC_MDELEM_REF(channeld->method));
       grpc_metadata_batch_add_head(&op->data.metadata, &calld->scheme,
                                    GRPC_MDELEM_REF(channeld->scheme));
+      if (channeld->default_authority && !calld->sent_authority) {
+        grpc_metadata_batch_add_head(&op->data.metadata, &calld->authority, GRPC_MDELEM_REF(channeld->default_authority));
+      }
       grpc_metadata_batch_add_tail(&op->data.metadata, &calld->te_trailers,
                                    GRPC_MDELEM_REF(channeld->te_trailers));
       grpc_metadata_batch_add_tail(&op->data.metadata, &calld->content_type,
@@ -162,6 +172,7 @@ static void init_call_elem(grpc_call_element *elem,
   call_data *calld = elem->call_data;
   calld->sent_initial_metadata = 0;
   calld->got_initial_metadata = 0;
+  calld->sent_authority = 0;
   calld->on_done_recv = NULL;
   grpc_iomgr_closure_init(&calld->hc_on_recv, hc_on_recv, elem);
   if (initial_op) hc_mutate_op(elem, initial_op);
@@ -241,8 +252,10 @@ static grpc_mdstr *user_agent_from_args(grpc_mdctx *mdctx,
 
 /* Constructor for channel_data */
 static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
-                              const grpc_channel_args *args, grpc_mdctx *mdctx,
+                              const grpc_channel_args *channel_args, grpc_mdctx *mdctx,
                               int is_first, int is_last) {
+  size_t i;
+
   /* grab pointers to our data from the channel element */
   channel_data *channeld = elem->channel_data;
 
@@ -251,17 +264,32 @@ static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
      path */
   GPR_ASSERT(!is_last);
 
+  channeld->default_authority = NULL;
+  if (channel_args) {
+    for (i = 0; i < channel_args->num_args; i++) {
+      if (0 ==
+          strcmp(channel_args->args[i].key, GRPC_ARG_DEFAULT_AUTHORITY)) {
+        if (channel_args->args[i].type != GRPC_ARG_STRING) {
+          gpr_log(GPR_ERROR, "%s: must be an string",
+                  GRPC_ARG_MAX_CONCURRENT_STREAMS);
+        } else {
+          channeld->default_authority = grpc_mdelem_from_strings(mdctx, ":authority", channel_args->args[i].value.string);
+        }
+      }
+    }
+  }
+
   /* initialize members */
   channeld->te_trailers = grpc_mdelem_from_strings(mdctx, "te", "trailers");
   channeld->method = grpc_mdelem_from_strings(mdctx, ":method", "POST");
   channeld->scheme =
-      grpc_mdelem_from_strings(mdctx, ":scheme", scheme_from_args(args));
+      grpc_mdelem_from_strings(mdctx, ":scheme", scheme_from_args(channel_args));
   channeld->content_type =
       grpc_mdelem_from_strings(mdctx, "content-type", "application/grpc");
   channeld->status = grpc_mdelem_from_strings(mdctx, ":status", "200");
   channeld->user_agent = grpc_mdelem_from_metadata_strings(
       mdctx, grpc_mdstr_from_string(mdctx, "user-agent"),
-      user_agent_from_args(mdctx, args));
+      user_agent_from_args(mdctx, channel_args));
 }
 
 /* Destructor for channel data */
@@ -275,6 +303,9 @@ static void destroy_channel_elem(grpc_channel_element *elem) {
   GRPC_MDELEM_UNREF(channeld->content_type);
   GRPC_MDELEM_UNREF(channeld->status);
   GRPC_MDELEM_UNREF(channeld->user_agent);
+  if (channeld->default_authority) {
+    GRPC_MDELEM_UNREF(channeld->default_authority);
+  }
 }
 
 const grpc_channel_filter grpc_http_client_filter = {