Support >16kib frame sizes in core

6 files changed, 32 insertions, 8 deletions

diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.c b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
index 0e8dfb7d96..00999e3b94 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.c
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.c
@@ -408,6 +408,19 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
           push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_HEADER_LIST_SIZE,
                        (uint32_t)channel_args->args[i].value.integer);
         }
+      } else if (0 == strcmp(channel_args->args[i].key,
+                             GRPC_ARG_HTTP2_MAX_FRAME_SIZE)) {
+        if (channel_args->args[i].type != GRPC_ARG_INTEGER) {
+          gpr_log(GPR_ERROR, "%s: must be an integer",
+                  GRPC_ARG_HTTP2_MAX_FRAME_SIZE);
+        } else if (channel_args->args[i].value.integer < 16384 ||
+                   channel_args->args[i].value.integer > 16777215) {
+          gpr_log(GPR_ERROR, "%s: must be between 16384 and 16777215",
+                  GRPC_ARG_HTTP2_MAX_FRAME_SIZE);
+        } else {
+          push_setting(exec_ctx, t, GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE,
+                       (uint32_t)channel_args->args[i].value.integer);
+        }
       }
     }
   }
diff --git a/src/core/ext/transport/chttp2/transport/frame.h b/src/core/ext/transport/chttp2/transport/frame.h
index 7776609367..507aae4100 100644
--- a/src/core/ext/transport/chttp2/transport/frame.h
+++ b/src/core/ext/transport/chttp2/transport/frame.h
@@ -52,8 +52,6 @@ typedef struct grpc_chttp2_transport_parsing grpc_chttp2_transport_parsing;
 #define GRPC_CHTTP2_FRAME_GOAWAY 7
 #define GRPC_CHTTP2_FRAME_WINDOW_UPDATE 8
 
-#define GRPC_CHTTP2_MAX_PAYLOAD_LENGTH ((1 << 14) - 1)
-
 #define GRPC_CHTTP2_DATA_FLAG_END_STREAM 1
 #define GRPC_CHTTP2_FLAG_ACK 1
 #define GRPC_CHTTP2_DATA_FLAG_END_HEADERS 4
diff --git a/src/core/ext/transport/chttp2/transport/hpack_encoder.c b/src/core/ext/transport/chttp2/transport/hpack_encoder.c
index 2cb8205d94..581471ba02 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_encoder.c
+++ b/src/core/ext/transport/chttp2/transport/hpack_encoder.c
@@ -78,6 +78,8 @@ typedef struct {
   uint32_t stream_id;
   gpr_slice_buffer *output;
   grpc_transport_one_way_stats *stats;
+  /* maximum size of a frame */
+  size_t max_frame_size;
 } framer_state;
 
 /* fills p (which is expected to be 9 bytes long) with a data frame header */
@@ -123,7 +125,7 @@ static void begin_frame(framer_state *st) {
    needed */
 static void ensure_space(framer_state *st, size_t need_bytes) {
   if (st->output->length - st->output_length_at_start_of_frame + need_bytes <=
-      GRPC_CHTTP2_MAX_PAYLOAD_LENGTH) {
+      st->max_frame_size) {
     return;
   }
   finish_frame(st, 0, 0);
@@ -149,8 +151,8 @@ static void add_header_data(framer_state *st, gpr_slice slice) {
   size_t len = GPR_SLICE_LENGTH(slice);
   size_t remaining;
   if (len == 0) return;
-  remaining = GRPC_CHTTP2_MAX_PAYLOAD_LENGTH +
-              st->output_length_at_start_of_frame - st->output->length;
+  remaining = st->max_frame_size + st->output_length_at_start_of_frame -
+              st->output->length;
   if (len <= remaining) {
     st->stats->header_bytes += len;
     gpr_slice_buffer_add(st->output, slice);
@@ -542,6 +544,7 @@ void grpc_chttp2_hpack_compressor_set_max_table_size(
 void grpc_chttp2_encode_header(grpc_chttp2_hpack_compressor *c,
                                uint32_t stream_id,
                                grpc_metadata_batch *metadata, int is_eof,
+                               size_t max_frame_size,
                                grpc_transport_one_way_stats *stats,
                                gpr_slice_buffer *outbuf) {
   framer_state st;
@@ -555,6 +558,7 @@ void grpc_chttp2_encode_header(grpc_chttp2_hpack_compressor *c,
   st.output = outbuf;
   st.is_first_frame = 1;
   st.stats = stats;
+  st.max_frame_size = max_frame_size;
 
   /* Encode a metadata batch; store the returned values, representing
      a metadata element that needs to be unreffed back into the metadata
diff --git a/src/core/ext/transport/chttp2/transport/hpack_encoder.h b/src/core/ext/transport/chttp2/transport/hpack_encoder.h
index 0f7b0b063a..4c3a931549 100644
--- a/src/core/ext/transport/chttp2/transport/hpack_encoder.h
+++ b/src/core/ext/transport/chttp2/transport/hpack_encoder.h
@@ -91,6 +91,7 @@ void grpc_chttp2_hpack_compressor_set_max_usable_size(
 
 void grpc_chttp2_encode_header(grpc_chttp2_hpack_compressor *c, uint32_t id,
                                grpc_metadata_batch *metadata, int is_eof,
+                               size_t max_frame_size,
                                grpc_transport_one_way_stats *stats,
                                gpr_slice_buffer *outbuf);
 
diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index e1dcf5262a..d67c014e54 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -223,6 +223,8 @@ typedef struct {
   uint8_t is_client;
   /** callback for when writing is done */
   grpc_closure done_cb;
+  /** maximum frame size */
+  uint32_t max_frame_size;
 } grpc_chttp2_transport_writing;
 
 struct grpc_chttp2_transport_parsing {
diff --git a/src/core/ext/transport/chttp2/transport/writing.c b/src/core/ext/transport/chttp2/transport/writing.c
index 8f7a1f55c6..80068744cc 100644
--- a/src/core/ext/transport/chttp2/transport/writing.c
+++ b/src/core/ext/transport/chttp2/transport/writing.c
@@ -51,6 +51,10 @@ int grpc_chttp2_unlocking_check_writes(
 
   GPR_TIMER_BEGIN("grpc_chttp2_unlocking_check_writes", 0);
 
+  transport_writing->max_frame_size =
+      transport_global
+          ->settings[GRPC_ACKED_SETTINGS][GRPC_CHTTP2_SETTINGS_MAX_FRAME_SIZE];
+
   /* simple writes are queued to qbuf, and flushed here */
   gpr_slice_buffer_swap(&transport_global->qbuf, &transport_writing->outbuf);
   GPR_ASSERT(transport_global->qbuf.count == 0);
@@ -206,14 +210,15 @@ static void finalize_outbuf(grpc_exec_ctx *exec_ctx,
   while (
       grpc_chttp2_list_pop_writing_stream(transport_writing, &stream_writing)) {
     uint32_t max_outgoing =
-        (uint32_t)GPR_MIN(GRPC_CHTTP2_MAX_PAYLOAD_LENGTH,
+        (uint32_t)GPR_MIN(transport_writing->max_frame_size,
                           GPR_MIN(stream_writing->outgoing_window,
                                   transport_writing->outgoing_window));
     /* send initial metadata if it's available */
     if (stream_writing->send_initial_metadata != NULL) {
       grpc_chttp2_encode_header(
           &transport_writing->hpack_compressor, stream_writing->id,
-          stream_writing->send_initial_metadata, 0, &stream_writing->stats,
+          stream_writing->send_initial_metadata, 0,
+          transport_writing->max_frame_size, &stream_writing->stats,
           &transport_writing->outbuf);
       stream_writing->send_initial_metadata = NULL;
       stream_writing->sent_initial_metadata = 1;
@@ -303,7 +308,8 @@ static void finalize_outbuf(grpc_exec_ctx *exec_ctx,
       } else {
         grpc_chttp2_encode_header(
             &transport_writing->hpack_compressor, stream_writing->id,
-            stream_writing->send_trailing_metadata, 1, &stream_writing->stats,
+            stream_writing->send_trailing_metadata, 1,
+            transport_writing->max_frame_size, &stream_writing->stats,
             &transport_writing->outbuf);
       }
       if (!transport_writing->is_client && !stream_writing->read_closed) {