--- /dev/null
+/*
+ *
+ * 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/slice/slice_internal.h"
+#include "src/core/lib/surface/validate_metadata.h"
+#include "src/core/lib/transport/static_metadata.h"
+
+extern grpc_core::TraceFlag grpc_http_trace;
+
+void grpc_chttp2_hptbl_destroy(grpc_chttp2_hptbl* tbl) {
+ size_t 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);
+ tbl->ents = nullptr;
+}
+
+template <bool take_ref>
+static grpc_mdelem lookup_dynamic_index(const grpc_chttp2_hptbl* tbl,
+ uint32_t tbl_index) {
+ /* Not static - 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;
+ grpc_mdelem md = tbl->ents[offset];
+ if (take_ref) {
+ GRPC_MDELEM_REF(md);
+ }
+ return md;
+ }
+ /* Invalid entry: return error */
+ return GRPC_MDNULL;
+}
+
+grpc_mdelem grpc_chttp2_hptbl_lookup_dynamic_index(const grpc_chttp2_hptbl* tbl,
+ uint32_t tbl_index) {
+ return lookup_dynamic_index<false>(tbl, tbl_index);
+}
+
+grpc_mdelem grpc_chttp2_hptbl_lookup_ref_dynamic_index(
+ const grpc_chttp2_hptbl* tbl, uint32_t tbl_index) {
+ return lookup_dynamic_index<true>(tbl, tbl_index);
+}
+
+/* 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_TRACE_FLAG_ENABLED(grpc_http_trace)) {
+ 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_TRACE_FLAG_ENABLED(grpc_http_trace)) {
+ 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 = grpc_chttp2_hptbl::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 = grpc_static_mdelem_manifested()[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) {
+ const uint8_t* key_buf = GRPC_SLICE_START_PTR(GRPC_MDKEY(elem));
+ size_t key_len = GRPC_SLICE_LENGTH(GRPC_MDKEY(elem));
+ size_t overhead_and_key = 32 + key_len;
+ size_t value_len = GRPC_SLICE_LENGTH(GRPC_MDVALUE(elem));
+ if (grpc_key_is_binary_header(key_buf, key_len)) {
+ return overhead_and_key + (use_true_binary_metadata
+ ? value_len + 1
+ : get_base64_encoded_size(value_len));
+ } else {
+ return overhead_and_key + value_len;
+ }
+}