| /* |
| * |
| * 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/hpack_table.h" |
| |
| #include <assert.h> |
| #include <string.h> |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| #include <grpc/support/string_util.h> |
| |
| #include "src/core/lib/debug/trace.h" |
| #include "src/core/lib/gpr/murmur_hash.h" |
| #include "src/core/lib/transport/static_metadata.h" |
| |
| extern grpc_core::TraceFlag grpc_http_trace; |
| |
| static struct { |
| const char* key; |
| const char* value; |
| } static_table[] = { |
| /* 0: */ |
| {nullptr, nullptr}, |
| /* 1: */ |
| {":authority", ""}, |
| /* 2: */ |
| {":method", "GET"}, |
| /* 3: */ |
| {":method", "POST"}, |
| /* 4: */ |
| {":path", "/"}, |
| /* 5: */ |
| {":path", "/index.html"}, |
| /* 6: */ |
| {":scheme", "http"}, |
| /* 7: */ |
| {":scheme", "https"}, |
| /* 8: */ |
| {":status", "200"}, |
| /* 9: */ |
| {":status", "204"}, |
| /* 10: */ |
| {":status", "206"}, |
| /* 11: */ |
| {":status", "304"}, |
| /* 12: */ |
| {":status", "400"}, |
| /* 13: */ |
| {":status", "404"}, |
| /* 14: */ |
| {":status", "500"}, |
| /* 15: */ |
| {"accept-charset", ""}, |
| /* 16: */ |
| {"accept-encoding", "gzip, deflate"}, |
| /* 17: */ |
| {"accept-language", ""}, |
| /* 18: */ |
| {"accept-ranges", ""}, |
| /* 19: */ |
| {"accept", ""}, |
| /* 20: */ |
| {"access-control-allow-origin", ""}, |
| /* 21: */ |
| {"age", ""}, |
| /* 22: */ |
| {"allow", ""}, |
| /* 23: */ |
| {"authorization", ""}, |
| /* 24: */ |
| {"cache-control", ""}, |
| /* 25: */ |
| {"content-disposition", ""}, |
| /* 26: */ |
| {"content-encoding", ""}, |
| /* 27: */ |
| {"content-language", ""}, |
| /* 28: */ |
| {"content-length", ""}, |
| /* 29: */ |
| {"content-location", ""}, |
| /* 30: */ |
| {"content-range", ""}, |
| /* 31: */ |
| {"content-type", ""}, |
| /* 32: */ |
| {"cookie", ""}, |
| /* 33: */ |
| {"date", ""}, |
| /* 34: */ |
| {"etag", ""}, |
| /* 35: */ |
| {"expect", ""}, |
| /* 36: */ |
| {"expires", ""}, |
| /* 37: */ |
| {"from", ""}, |
| /* 38: */ |
| {"host", ""}, |
| /* 39: */ |
| {"if-match", ""}, |
| /* 40: */ |
| {"if-modified-since", ""}, |
| /* 41: */ |
| {"if-none-match", ""}, |
| /* 42: */ |
| {"if-range", ""}, |
| /* 43: */ |
| {"if-unmodified-since", ""}, |
| /* 44: */ |
| {"last-modified", ""}, |
| /* 45: */ |
| {"link", ""}, |
| /* 46: */ |
| {"location", ""}, |
| /* 47: */ |
| {"max-forwards", ""}, |
| /* 48: */ |
| {"proxy-authenticate", ""}, |
| /* 49: */ |
| {"proxy-authorization", ""}, |
| /* 50: */ |
| {"range", ""}, |
| /* 51: */ |
| {"referer", ""}, |
| /* 52: */ |
| {"refresh", ""}, |
| /* 53: */ |
| {"retry-after", ""}, |
| /* 54: */ |
| {"server", ""}, |
| /* 55: */ |
| {"set-cookie", ""}, |
| /* 56: */ |
| {"strict-transport-security", ""}, |
| /* 57: */ |
| {"transfer-encoding", ""}, |
| /* 58: */ |
| {"user-agent", ""}, |
| /* 59: */ |
| {"vary", ""}, |
| /* 60: */ |
| {"via", ""}, |
| /* 61: */ |
| {"www-authenticate", ""}, |
| }; |
| |
| static uint32_t entries_for_bytes(uint32_t bytes) { |
| return (bytes + GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD - 1) / |
| GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD; |
| } |
| |
| void grpc_chttp2_hptbl_init(grpc_chttp2_hptbl* tbl) { |
| size_t i; |
| |
| memset(tbl, 0, sizeof(*tbl)); |
| tbl->current_table_bytes = tbl->max_bytes = |
| GRPC_CHTTP2_INITIAL_HPACK_TABLE_SIZE; |
| tbl->max_entries = tbl->cap_entries = |
| entries_for_bytes(tbl->current_table_bytes); |
| tbl->ents = static_cast<grpc_mdelem*>( |
| gpr_malloc(sizeof(*tbl->ents) * tbl->cap_entries)); |
| memset(tbl->ents, 0, sizeof(*tbl->ents) * tbl->cap_entries); |
| for (i = 1; i <= GRPC_CHTTP2_LAST_STATIC_ENTRY; i++) { |
| tbl->static_ents[i - 1] = grpc_mdelem_from_slices( |
| grpc_slice_intern(grpc_slice_from_static_string(static_table[i].key)), |
| grpc_slice_intern( |
| grpc_slice_from_static_string(static_table[i].value))); |
| } |
| } |
| |
| void grpc_chttp2_hptbl_destroy(grpc_chttp2_hptbl* tbl) { |
| size_t i; |
| for (i = 0; i < GRPC_CHTTP2_LAST_STATIC_ENTRY; i++) { |
| GRPC_MDELEM_UNREF(tbl->static_ents[i]); |
| } |
| for (i = 0; i < tbl->num_ents; i++) { |
| GRPC_MDELEM_UNREF(tbl->ents[(tbl->first_ent + i) % tbl->cap_entries]); |
| } |
| gpr_free(tbl->ents); |
| } |
| |
| grpc_mdelem grpc_chttp2_hptbl_lookup(const grpc_chttp2_hptbl* tbl, |
| uint32_t tbl_index) { |
| /* Static table comes first, just return an entry from it */ |
| if (tbl_index <= GRPC_CHTTP2_LAST_STATIC_ENTRY) { |
| return tbl->static_ents[tbl_index - 1]; |
| } |
| /* Otherwise, find the value in the list of valid entries */ |
| tbl_index -= (GRPC_CHTTP2_LAST_STATIC_ENTRY + 1); |
| if (tbl_index < tbl->num_ents) { |
| uint32_t offset = |
| (tbl->num_ents - 1u - tbl_index + tbl->first_ent) % tbl->cap_entries; |
| return tbl->ents[offset]; |
| } |
| /* Invalid entry: return error */ |
| return GRPC_MDNULL; |
| } |
| |
| /* Evict one element from the table */ |
| static void evict1(grpc_chttp2_hptbl* tbl) { |
| grpc_mdelem first_ent = tbl->ents[tbl->first_ent]; |
| size_t elem_bytes = GRPC_SLICE_LENGTH(GRPC_MDKEY(first_ent)) + |
| GRPC_SLICE_LENGTH(GRPC_MDVALUE(first_ent)) + |
| GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD; |
| GPR_ASSERT(elem_bytes <= tbl->mem_used); |
| tbl->mem_used -= static_cast<uint32_t>(elem_bytes); |
| tbl->first_ent = ((tbl->first_ent + 1) % tbl->cap_entries); |
| tbl->num_ents--; |
| GRPC_MDELEM_UNREF(first_ent); |
| } |
| |
| static void rebuild_ents(grpc_chttp2_hptbl* tbl, uint32_t new_cap) { |
| grpc_mdelem* ents = |
| static_cast<grpc_mdelem*>(gpr_malloc(sizeof(*ents) * new_cap)); |
| uint32_t i; |
| |
| for (i = 0; i < tbl->num_ents; i++) { |
| ents[i] = tbl->ents[(tbl->first_ent + i) % tbl->cap_entries]; |
| } |
| gpr_free(tbl->ents); |
| tbl->ents = ents; |
| tbl->cap_entries = new_cap; |
| tbl->first_ent = 0; |
| } |
| |
| void grpc_chttp2_hptbl_set_max_bytes(grpc_chttp2_hptbl* tbl, |
| uint32_t max_bytes) { |
| if (tbl->max_bytes == max_bytes) { |
| return; |
| } |
| if (grpc_http_trace.enabled()) { |
| gpr_log(GPR_INFO, "Update hpack parser max size to %d", max_bytes); |
| } |
| while (tbl->mem_used > max_bytes) { |
| evict1(tbl); |
| } |
| tbl->max_bytes = max_bytes; |
| } |
| |
| grpc_error* grpc_chttp2_hptbl_set_current_table_size(grpc_chttp2_hptbl* tbl, |
| uint32_t bytes) { |
| if (tbl->current_table_bytes == bytes) { |
| return GRPC_ERROR_NONE; |
| } |
| if (bytes > tbl->max_bytes) { |
| char* msg; |
| gpr_asprintf(&msg, |
| "Attempt to make hpack table %d bytes when max is %d bytes", |
| bytes, tbl->max_bytes); |
| grpc_error* err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg); |
| gpr_free(msg); |
| return err; |
| } |
| if (grpc_http_trace.enabled()) { |
| gpr_log(GPR_INFO, "Update hpack parser table size to %d", bytes); |
| } |
| while (tbl->mem_used > bytes) { |
| evict1(tbl); |
| } |
| tbl->current_table_bytes = bytes; |
| tbl->max_entries = entries_for_bytes(bytes); |
| if (tbl->max_entries > tbl->cap_entries) { |
| rebuild_ents(tbl, GPR_MAX(tbl->max_entries, 2 * tbl->cap_entries)); |
| } else if (tbl->max_entries < tbl->cap_entries / 3) { |
| uint32_t new_cap = GPR_MAX(tbl->max_entries, 16u); |
| if (new_cap != tbl->cap_entries) { |
| rebuild_ents(tbl, new_cap); |
| } |
| } |
| return GRPC_ERROR_NONE; |
| } |
| |
| grpc_error* grpc_chttp2_hptbl_add(grpc_chttp2_hptbl* tbl, grpc_mdelem md) { |
| /* determine how many bytes of buffer this entry represents */ |
| size_t elem_bytes = GRPC_SLICE_LENGTH(GRPC_MDKEY(md)) + |
| GRPC_SLICE_LENGTH(GRPC_MDVALUE(md)) + |
| GRPC_CHTTP2_HPACK_ENTRY_OVERHEAD; |
| |
| if (tbl->current_table_bytes > tbl->max_bytes) { |
| char* msg; |
| gpr_asprintf( |
| &msg, |
| "HPACK max table size reduced to %d but not reflected by hpack " |
| "stream (still at %d)", |
| tbl->max_bytes, tbl->current_table_bytes); |
| grpc_error* err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg); |
| gpr_free(msg); |
| return err; |
| } |
| |
| /* we can't add elements bigger than the max table size */ |
| if (elem_bytes > tbl->current_table_bytes) { |
| /* HPACK draft 10 section 4.4 states: |
| * If the size of the new entry is less than or equal to the maximum |
| * size, that entry is added to the table. It is not an error to |
| * attempt to add an entry that is larger than the maximum size; an |
| * attempt to add an entry larger than the entire table causes |
| * the table |
| * to be emptied of all existing entries, and results in an |
| * empty table. |
| */ |
| while (tbl->num_ents) { |
| evict1(tbl); |
| } |
| return GRPC_ERROR_NONE; |
| } |
| |
| /* evict entries to ensure no overflow */ |
| while (elem_bytes > |
| static_cast<size_t>(tbl->current_table_bytes) - tbl->mem_used) { |
| evict1(tbl); |
| } |
| |
| /* copy the finalized entry in */ |
| tbl->ents[(tbl->first_ent + tbl->num_ents) % tbl->cap_entries] = |
| GRPC_MDELEM_REF(md); |
| |
| /* update accounting values */ |
| tbl->num_ents++; |
| tbl->mem_used += static_cast<uint32_t>(elem_bytes); |
| return GRPC_ERROR_NONE; |
| } |
| |
| grpc_chttp2_hptbl_find_result grpc_chttp2_hptbl_find( |
| const grpc_chttp2_hptbl* tbl, grpc_mdelem md) { |
| grpc_chttp2_hptbl_find_result r = {0, 0}; |
| uint32_t i; |
| |
| /* See if the string is in the static table */ |
| for (i = 0; i < GRPC_CHTTP2_LAST_STATIC_ENTRY; i++) { |
| grpc_mdelem ent = tbl->static_ents[i]; |
| if (!grpc_slice_eq(GRPC_MDKEY(md), GRPC_MDKEY(ent))) continue; |
| r.index = i + 1u; |
| r.has_value = grpc_slice_eq(GRPC_MDVALUE(md), GRPC_MDVALUE(ent)); |
| if (r.has_value) return r; |
| } |
| |
| /* Scan the dynamic table */ |
| for (i = 0; i < tbl->num_ents; i++) { |
| uint32_t idx = static_cast<uint32_t>(tbl->num_ents - i + |
| GRPC_CHTTP2_LAST_STATIC_ENTRY); |
| grpc_mdelem ent = tbl->ents[(tbl->first_ent + i) % tbl->cap_entries]; |
| if (!grpc_slice_eq(GRPC_MDKEY(md), GRPC_MDKEY(ent))) continue; |
| r.index = idx; |
| r.has_value = grpc_slice_eq(GRPC_MDVALUE(md), GRPC_MDVALUE(ent)); |
| if (r.has_value) return r; |
| } |
| |
| return r; |
| } |
| |
| static size_t get_base64_encoded_size(size_t raw_length) { |
| static const uint8_t tail_xtra[3] = {0, 2, 3}; |
| return raw_length / 3 * 4 + tail_xtra[raw_length % 3]; |
| } |
| |
| size_t grpc_chttp2_get_size_in_hpack_table(grpc_mdelem elem, |
| bool use_true_binary_metadata) { |
| size_t overhead_and_key = 32 + GRPC_SLICE_LENGTH(GRPC_MDKEY(elem)); |
| size_t value_len = GRPC_SLICE_LENGTH(GRPC_MDVALUE(elem)); |
| if (grpc_is_binary_header(GRPC_MDKEY(elem))) { |
| return overhead_and_key + (use_true_binary_metadata |
| ? value_len + 1 |
| : get_base64_encoded_size(value_len)); |
| } else { |
| return overhead_and_key + value_len; |
| } |
| } |
| |
| uint8_t grpc_chttp2_get_static_hpack_table_index(grpc_mdelem md) { |
| if (GRPC_MDELEM_STORAGE(md) == GRPC_MDELEM_STORAGE_STATIC) { |
| uint8_t index = GRPC_MDELEM_DATA(md) - grpc_static_mdelem_table; |
| if (index < GRPC_CHTTP2_LAST_STATIC_ENTRY) { |
| return index + 1; // Hpack static metadata element indices start at 1 |
| } |
| } |
| return 0; |
| } |