| /* |
| * |
| * Copyright 2015 gRPC authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| #include <grpc/support/port_platform.h> |
| |
| #include "src/core/ext/transport/chttp2/transport/frame_window_update.h" |
| #include "src/core/ext/transport/chttp2/transport/internal.h" |
| |
| #include "absl/strings/str_cat.h" |
| #include "absl/strings/str_format.h" |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| |
| grpc_slice grpc_chttp2_window_update_create( |
| uint32_t id, uint32_t window_delta, grpc_transport_one_way_stats* stats) { |
| static const size_t frame_size = 13; |
| grpc_slice slice = GRPC_SLICE_MALLOC(frame_size); |
| stats->header_bytes += frame_size; |
| uint8_t* p = GRPC_SLICE_START_PTR(slice); |
| |
| GPR_ASSERT(window_delta); |
| |
| *p++ = 0; |
| *p++ = 0; |
| *p++ = 4; |
| *p++ = GRPC_CHTTP2_FRAME_WINDOW_UPDATE; |
| *p++ = 0; |
| *p++ = static_cast<uint8_t>(id >> 24); |
| *p++ = static_cast<uint8_t>(id >> 16); |
| *p++ = static_cast<uint8_t>(id >> 8); |
| *p++ = static_cast<uint8_t>(id); |
| *p++ = static_cast<uint8_t>(window_delta >> 24); |
| *p++ = static_cast<uint8_t>(window_delta >> 16); |
| *p++ = static_cast<uint8_t>(window_delta >> 8); |
| *p++ = static_cast<uint8_t>(window_delta); |
| |
| return slice; |
| } |
| |
| grpc_error_handle grpc_chttp2_window_update_parser_begin_frame( |
| grpc_chttp2_window_update_parser* parser, uint32_t length, uint8_t flags) { |
| if (flags || length != 4) { |
| return GRPC_ERROR_CREATE_FROM_COPIED_STRING( |
| absl::StrFormat("invalid window update: length=%d, flags=%02x", length, |
| flags) |
| .c_str()); |
| } |
| parser->byte = 0; |
| parser->amount = 0; |
| return GRPC_ERROR_NONE; |
| } |
| |
| grpc_error_handle grpc_chttp2_window_update_parser_parse( |
| void* parser, grpc_chttp2_transport* t, grpc_chttp2_stream* s, |
| const grpc_slice& slice, int is_last) { |
| const uint8_t* const beg = GRPC_SLICE_START_PTR(slice); |
| const uint8_t* const end = GRPC_SLICE_END_PTR(slice); |
| const uint8_t* cur = beg; |
| grpc_chttp2_window_update_parser* p = |
| static_cast<grpc_chttp2_window_update_parser*>(parser); |
| |
| while (p->byte != 4 && cur != end) { |
| p->amount |= (static_cast<uint32_t>(*cur)) << (8 * (3 - p->byte)); |
| cur++; |
| p->byte++; |
| } |
| |
| if (s != nullptr) { |
| s->stats.incoming.framing_bytes += static_cast<uint32_t>(end - cur); |
| } |
| |
| if (p->byte == 4) { |
| // top bit is reserved and must be ignored. |
| uint32_t received_update = p->amount & 0x7fffffffu; |
| if (received_update == 0) { |
| return GRPC_ERROR_CREATE_FROM_COPIED_STRING( |
| absl::StrCat("invalid window update bytes: ", p->amount).c_str()); |
| } |
| GPR_ASSERT(is_last); |
| |
| if (t->incoming_stream_id != 0) { |
| if (s != nullptr) { |
| s->flow_control->RecvUpdate(received_update); |
| if (grpc_chttp2_list_remove_stalled_by_stream(t, s)) { |
| grpc_chttp2_mark_stream_writable(t, s); |
| grpc_chttp2_initiate_write( |
| t, GRPC_CHTTP2_INITIATE_WRITE_FLOW_CONTROL_UNSTALLED_BY_UPDATE); |
| } |
| } |
| } else { |
| bool was_zero = t->flow_control->remote_window() <= 0; |
| t->flow_control->RecvUpdate(received_update); |
| bool is_zero = t->flow_control->remote_window() <= 0; |
| if (was_zero && !is_zero) { |
| grpc_chttp2_initiate_write( |
| t, GRPC_CHTTP2_INITIATE_WRITE_TRANSPORT_FLOW_CONTROL_UNSTALLED); |
| } |
| } |
| } |
| |
| return GRPC_ERROR_NONE; |
| } |