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-rw-r--r--modules/http2/h2_conn_io.c389
1 files changed, 389 insertions, 0 deletions
diff --git a/modules/http2/h2_conn_io.c b/modules/http2/h2_conn_io.c
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+++ b/modules/http2/h2_conn_io.c
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+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 <assert.h>
+#include <apr_strings.h>
+#include <ap_mpm.h>
+
+#include <httpd.h>
+#include <http_core.h>
+#include <http_log.h>
+#include <http_connection.h>
+#include <http_request.h>
+
+#include "h2_private.h"
+#include "h2_bucket_eos.h"
+#include "h2_config.h"
+#include "h2_conn_io.h"
+#include "h2_h2.h"
+#include "h2_session.h"
+#include "h2_util.h"
+
+#define TLS_DATA_MAX (16*1024)
+
+/* Calculated like this: assuming MTU 1500 bytes
+ * 1500 - 40 (IP) - 20 (TCP) - 40 (TCP options)
+ * - TLS overhead (60-100)
+ * ~= 1300 bytes */
+#define WRITE_SIZE_INITIAL 1300
+
+/* Calculated like this: max TLS record size 16*1024
+ * - 40 (IP) - 20 (TCP) - 40 (TCP options)
+ * - TLS overhead (60-100)
+ * which seems to create less TCP packets overall
+ */
+#define WRITE_SIZE_MAX (TLS_DATA_MAX - 100)
+
+
+static void h2_conn_io_bb_log(conn_rec *c, int stream_id, int level,
+ const char *tag, apr_bucket_brigade *bb)
+{
+ char buffer[16 * 1024];
+ const char *line = "(null)";
+ apr_size_t bmax = sizeof(buffer)/sizeof(buffer[0]);
+ int off = 0;
+ apr_bucket *b;
+
+ if (bb) {
+ memset(buffer, 0, bmax--);
+ for (b = APR_BRIGADE_FIRST(bb);
+ bmax && (b != APR_BRIGADE_SENTINEL(bb));
+ b = APR_BUCKET_NEXT(b)) {
+
+ if (APR_BUCKET_IS_METADATA(b)) {
+ if (APR_BUCKET_IS_EOS(b)) {
+ off += apr_snprintf(buffer+off, bmax-off, "eos ");
+ }
+ else if (APR_BUCKET_IS_FLUSH(b)) {
+ off += apr_snprintf(buffer+off, bmax-off, "flush ");
+ }
+ else if (AP_BUCKET_IS_EOR(b)) {
+ off += apr_snprintf(buffer+off, bmax-off, "eor ");
+ }
+ else if (H2_BUCKET_IS_H2EOS(b)) {
+ off += apr_snprintf(buffer+off, bmax-off, "h2eos ");
+ }
+ else {
+ off += apr_snprintf(buffer+off, bmax-off, "meta(unknown) ");
+ }
+ }
+ else {
+ const char *btype = "data";
+ if (APR_BUCKET_IS_FILE(b)) {
+ btype = "file";
+ }
+ else if (APR_BUCKET_IS_PIPE(b)) {
+ btype = "pipe";
+ }
+ else if (APR_BUCKET_IS_SOCKET(b)) {
+ btype = "socket";
+ }
+ else if (APR_BUCKET_IS_HEAP(b)) {
+ btype = "heap";
+ }
+ else if (APR_BUCKET_IS_TRANSIENT(b)) {
+ btype = "transient";
+ }
+ else if (APR_BUCKET_IS_IMMORTAL(b)) {
+ btype = "immortal";
+ }
+#if APR_HAS_MMAP
+ else if (APR_BUCKET_IS_MMAP(b)) {
+ btype = "mmap";
+ }
+#endif
+ else if (APR_BUCKET_IS_POOL(b)) {
+ btype = "pool";
+ }
+
+ off += apr_snprintf(buffer+off, bmax-off, "%s[%ld] ",
+ btype,
+ (long)(b->length == ((apr_size_t)-1)?
+ -1 : b->length));
+ }
+ }
+ line = *buffer? buffer : "(empty)";
+ }
+ /* Intentional no APLOGNO */
+ ap_log_cerror(APLOG_MARK, level, 0, c, "h2_session(%ld)-%s: %s",
+ c->id, tag, line);
+
+}
+
+apr_status_t h2_conn_io_init(h2_conn_io *io, conn_rec *c,
+ const h2_config *cfg)
+{
+ io->c = c;
+ io->output = apr_brigade_create(c->pool, c->bucket_alloc);
+ io->is_tls = h2_h2_is_tls(c);
+ io->buffer_output = io->is_tls;
+ io->flush_threshold = (apr_size_t)h2_config_geti64(cfg, H2_CONF_STREAM_MAX_MEM);
+
+ if (io->is_tls) {
+ /* This is what we start with,
+ * see https://issues.apache.org/jira/browse/TS-2503
+ */
+ io->warmup_size = h2_config_geti64(cfg, H2_CONF_TLS_WARMUP_SIZE);
+ io->cooldown_usecs = (h2_config_geti(cfg, H2_CONF_TLS_COOLDOWN_SECS)
+ * APR_USEC_PER_SEC);
+ io->write_size = (io->cooldown_usecs > 0?
+ WRITE_SIZE_INITIAL : WRITE_SIZE_MAX);
+ }
+ else {
+ io->warmup_size = 0;
+ io->cooldown_usecs = 0;
+ io->write_size = 0;
+ }
+
+ if (APLOGctrace1(c)) {
+ ap_log_cerror(APLOG_MARK, APLOG_TRACE4, 0, io->c,
+ "h2_conn_io(%ld): init, buffering=%d, warmup_size=%ld, "
+ "cd_secs=%f", io->c->id, io->buffer_output,
+ (long)io->warmup_size,
+ ((float)io->cooldown_usecs/APR_USEC_PER_SEC));
+ }
+
+ return APR_SUCCESS;
+}
+
+static void append_scratch(h2_conn_io *io)
+{
+ if (io->scratch && io->slen > 0) {
+ apr_bucket *b = apr_bucket_heap_create(io->scratch, io->slen,
+ apr_bucket_free,
+ io->c->bucket_alloc);
+ APR_BRIGADE_INSERT_TAIL(io->output, b);
+ io->scratch = NULL;
+ io->slen = io->ssize = 0;
+ }
+}
+
+static apr_size_t assure_scratch_space(h2_conn_io *io) {
+ apr_size_t remain = io->ssize - io->slen;
+ if (io->scratch && remain == 0) {
+ append_scratch(io);
+ }
+ if (!io->scratch) {
+ /* we control the size and it is larger than what buckets usually
+ * allocate. */
+ io->scratch = apr_bucket_alloc(io->write_size, io->c->bucket_alloc);
+ io->ssize = io->write_size;
+ io->slen = 0;
+ remain = io->ssize;
+ }
+ return remain;
+}
+
+static apr_status_t read_to_scratch(h2_conn_io *io, apr_bucket *b)
+{
+ apr_status_t status;
+ const char *data;
+ apr_size_t len;
+
+ if (!b->length) {
+ return APR_SUCCESS;
+ }
+
+ ap_assert(b->length <= (io->ssize - io->slen));
+ if (APR_BUCKET_IS_FILE(b)) {
+ apr_bucket_file *f = (apr_bucket_file *)b->data;
+ apr_file_t *fd = f->fd;
+ apr_off_t offset = b->start;
+ apr_size_t len = b->length;
+
+ /* file buckets will either mmap (which we do not want) or
+ * read 8000 byte chunks and split themself. However, we do
+ * know *exactly* how many bytes we need where.
+ */
+ status = apr_file_seek(fd, APR_SET, &offset);
+ if (status != APR_SUCCESS) {
+ return status;
+ }
+ status = apr_file_read(fd, io->scratch + io->slen, &len);
+ if (status != APR_SUCCESS && status != APR_EOF) {
+ return status;
+ }
+ io->slen += len;
+ }
+ else {
+ status = apr_bucket_read(b, &data, &len, APR_BLOCK_READ);
+ if (status == APR_SUCCESS) {
+ memcpy(io->scratch+io->slen, data, len);
+ io->slen += len;
+ }
+ }
+ return status;
+}
+
+static void check_write_size(h2_conn_io *io)
+{
+ if (io->write_size > WRITE_SIZE_INITIAL
+ && (io->cooldown_usecs > 0)
+ && (apr_time_now() - io->last_write) >= io->cooldown_usecs) {
+ /* long time not written, reset write size */
+ io->write_size = WRITE_SIZE_INITIAL;
+ io->bytes_written = 0;
+ }
+ else if (io->write_size < WRITE_SIZE_MAX
+ && io->bytes_written >= io->warmup_size) {
+ /* connection is hot, use max size */
+ io->write_size = WRITE_SIZE_MAX;
+ }
+}
+
+static apr_status_t pass_output(h2_conn_io *io, int flush)
+{
+ conn_rec *c = io->c;
+ apr_bucket_brigade *bb = io->output;
+ apr_bucket *b;
+ apr_off_t bblen;
+ apr_status_t status;
+
+ append_scratch(io);
+ if (flush && !io->is_flushed) {
+ b = apr_bucket_flush_create(c->bucket_alloc);
+ APR_BRIGADE_INSERT_TAIL(bb, b);
+ }
+
+ if (APR_BRIGADE_EMPTY(bb)) {
+ return APR_SUCCESS;
+ }
+
+ ap_update_child_status(c->sbh, SERVER_BUSY_WRITE, NULL);
+ apr_brigade_length(bb, 0, &bblen);
+ h2_conn_io_bb_log(c, 0, APLOG_TRACE2, "out", bb);
+
+ status = ap_pass_brigade(c->output_filters, bb);
+ if (status == APR_SUCCESS) {
+ io->bytes_written += (apr_size_t)bblen;
+ io->last_write = apr_time_now();
+ if (flush) {
+ io->is_flushed = 1;
+ }
+ }
+ apr_brigade_cleanup(bb);
+
+ if (status != APR_SUCCESS) {
+ ap_log_cerror(APLOG_MARK, APLOG_DEBUG, status, c, APLOGNO(03044)
+ "h2_conn_io(%ld): pass_out brigade %ld bytes",
+ c->id, (long)bblen);
+ }
+ return status;
+}
+
+int h2_conn_io_needs_flush(h2_conn_io *io)
+{
+ if (!io->is_flushed) {
+ apr_off_t len = h2_brigade_mem_size(io->output);
+ if (len > io->flush_threshold) {
+ return 1;
+ }
+ /* if we do not exceed flush length due to memory limits,
+ * we want at least flush when we have that amount of data. */
+ apr_brigade_length(io->output, 0, &len);
+ return len > (4 * io->flush_threshold);
+ }
+ return 0;
+}
+
+apr_status_t h2_conn_io_flush(h2_conn_io *io)
+{
+ apr_status_t status;
+ status = pass_output(io, 1);
+ check_write_size(io);
+ return status;
+}
+
+apr_status_t h2_conn_io_write(h2_conn_io *io, const char *data, size_t length)
+{
+ apr_status_t status = APR_SUCCESS;
+ apr_size_t remain;
+
+ if (length > 0) {
+ io->is_flushed = 0;
+ }
+
+ if (io->buffer_output) {
+ while (length > 0) {
+ remain = assure_scratch_space(io);
+ if (remain >= length) {
+ memcpy(io->scratch + io->slen, data, length);
+ io->slen += length;
+ length = 0;
+ }
+ else {
+ memcpy(io->scratch + io->slen, data, remain);
+ io->slen += remain;
+ data += remain;
+ length -= remain;
+ }
+ }
+ }
+ else {
+ status = apr_brigade_write(io->output, NULL, NULL, data, length);
+ }
+ return status;
+}
+
+apr_status_t h2_conn_io_pass(h2_conn_io *io, apr_bucket_brigade *bb)
+{
+ apr_bucket *b;
+ apr_status_t status = APR_SUCCESS;
+
+ if (!APR_BRIGADE_EMPTY(bb)) {
+ io->is_flushed = 0;
+ }
+
+ while (!APR_BRIGADE_EMPTY(bb) && status == APR_SUCCESS) {
+ b = APR_BRIGADE_FIRST(bb);
+
+ if (APR_BUCKET_IS_METADATA(b)) {
+ /* need to finish any open scratch bucket, as meta data
+ * needs to be forward "in order". */
+ append_scratch(io);
+ APR_BUCKET_REMOVE(b);
+ APR_BRIGADE_INSERT_TAIL(io->output, b);
+ }
+ else if (io->buffer_output) {
+ apr_size_t remain = assure_scratch_space(io);
+ if (b->length > remain) {
+ apr_bucket_split(b, remain);
+ if (io->slen == 0) {
+ /* complete write_size bucket, append unchanged */
+ APR_BUCKET_REMOVE(b);
+ APR_BRIGADE_INSERT_TAIL(io->output, b);
+ continue;
+ }
+ }
+ else {
+ /* bucket fits in remain, copy to scratch */
+ status = read_to_scratch(io, b);
+ apr_bucket_delete(b);
+ continue;
+ }
+ }
+ else {
+ /* no buffering, forward buckets setaside on flush */
+ if (APR_BUCKET_IS_TRANSIENT(b)) {
+ apr_bucket_setaside(b, io->c->pool);
+ }
+ APR_BUCKET_REMOVE(b);
+ APR_BRIGADE_INSERT_TAIL(io->output, b);
+ }
+ }
+ return status;
+}
+
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