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nghttp2/lib/nghttp2_frame.c

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/*
* nghttp2 - HTTP/2.0 C Library
*
* Copyright (c) 2013 Tatsuhiro Tsujikawa
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "nghttp2_frame.h"
#include <string.h>
#include <assert.h>
#include <stdio.h>
#include <errno.h>
#include "nghttp2_helper.h"
#include "nghttp2_net.h"
int nghttp2_frame_is_data_frame(uint8_t *head)
{
return head[2] == 0;
}
void nghttp2_frame_pack_frame_hd(uint8_t* buf, const nghttp2_frame_hd *hd)
{
nghttp2_put_uint16be(&buf[0], hd->length);
buf[2]= hd->type;
buf[3] = hd->flags;
nghttp2_put_uint32be(&buf[4], hd->stream_id);
}
void nghttp2_frame_unpack_frame_hd(nghttp2_frame_hd *hd, const uint8_t* buf)
{
hd->length = nghttp2_get_uint16(&buf[0]) & NGHTTP2_FRAME_LENGTH_MASK;
hd->type = buf[2];
hd->flags = buf[3];
hd->stream_id = nghttp2_get_uint32(&buf[4]) & NGHTTP2_STREAM_ID_MASK;
}
static void nghttp2_frame_set_hd(nghttp2_frame_hd *hd, uint16_t length,
uint8_t type, uint8_t flags,
int32_t stream_id)
{
hd->length = length;
hd->type = type;
hd->flags = flags;
hd->stream_id = stream_id;
}
void nghttp2_frame_headers_init(nghttp2_headers *frame,
uint8_t flags, int32_t stream_id, int32_t pri,
nghttp2_nv *nva, size_t nvlen)
{
nghttp2_frame_set_hd(&frame->hd, 0, NGHTTP2_HEADERS, flags, stream_id);
frame->padlen = 0;
frame->nva = nva;
frame->nvlen = nvlen;
frame->cat = NGHTTP2_HCAT_REQUEST;
frame->pri = pri;
}
void nghttp2_frame_headers_free(nghttp2_headers *frame)
{
nghttp2_nv_array_del(frame->nva);
}
void nghttp2_frame_priority_init(nghttp2_priority *frame, int32_t stream_id,
int32_t pri)
{
nghttp2_frame_set_hd(&frame->hd, 4, NGHTTP2_PRIORITY, NGHTTP2_FLAG_NONE,
stream_id);
frame->pri = pri;
}
void nghttp2_frame_priority_free(nghttp2_priority *frame)
{}
void nghttp2_frame_rst_stream_init(nghttp2_rst_stream *frame,
int32_t stream_id,
nghttp2_error_code error_code)
{
nghttp2_frame_set_hd(&frame->hd, 4, NGHTTP2_RST_STREAM, NGHTTP2_FLAG_NONE,
stream_id);
frame->error_code = error_code;
}
void nghttp2_frame_rst_stream_free(nghttp2_rst_stream *frame)
{}
void nghttp2_frame_settings_init(nghttp2_settings *frame, uint8_t flags,
nghttp2_settings_entry *iv, size_t niv)
{
nghttp2_frame_set_hd(&frame->hd, niv * NGHTTP2_FRAME_SETTINGS_ENTRY_LENGTH,
NGHTTP2_SETTINGS, flags, 0);
frame->niv = niv;
frame->iv = iv;
}
void nghttp2_frame_settings_free(nghttp2_settings *frame)
{
free(frame->iv);
}
void nghttp2_frame_push_promise_init(nghttp2_push_promise *frame,
uint8_t flags, int32_t stream_id,
int32_t promised_stream_id,
nghttp2_nv *nva, size_t nvlen)
{
nghttp2_frame_set_hd(&frame->hd, 0, NGHTTP2_PUSH_PROMISE, flags, stream_id);
frame->padlen = 0;
frame->nva = nva;
frame->nvlen = nvlen;
frame->promised_stream_id = promised_stream_id;
}
void nghttp2_frame_push_promise_free(nghttp2_push_promise *frame)
{
nghttp2_nv_array_del(frame->nva);
}
void nghttp2_frame_ping_init(nghttp2_ping *frame, uint8_t flags,
const uint8_t *opaque_data)
{
nghttp2_frame_set_hd(&frame->hd, 8, NGHTTP2_PING, flags, 0);
if(opaque_data) {
memcpy(frame->opaque_data, opaque_data, sizeof(frame->opaque_data));
} else {
memset(frame->opaque_data, 0, sizeof(frame->opaque_data));
}
}
void nghttp2_frame_ping_free(nghttp2_ping *frame)
{}
void nghttp2_frame_goaway_init(nghttp2_goaway *frame, int32_t last_stream_id,
nghttp2_error_code error_code,
uint8_t *opaque_data, size_t opaque_data_len)
{
nghttp2_frame_set_hd(&frame->hd, 8+opaque_data_len, NGHTTP2_GOAWAY,
NGHTTP2_FLAG_NONE, 0);
frame->last_stream_id = last_stream_id;
frame->error_code = error_code;
frame->opaque_data = opaque_data;
frame->opaque_data_len = opaque_data_len;
}
void nghttp2_frame_goaway_free(nghttp2_goaway *frame)
{
free(frame->opaque_data);
}
void nghttp2_frame_window_update_init(nghttp2_window_update *frame,
uint8_t flags,
int32_t stream_id,
int32_t window_size_increment)
{
nghttp2_frame_set_hd(&frame->hd, 4, NGHTTP2_WINDOW_UPDATE, flags, stream_id);
frame->window_size_increment = window_size_increment;
}
void nghttp2_frame_window_update_free(nghttp2_window_update *frame)
{}
void nghttp2_frame_data_init(nghttp2_data *frame, nghttp2_private_data *pdata)
{
frame->hd = pdata->hd;
frame->padlen = pdata->padlen;
/* flags may have NGHTTP2_FLAG_END_STREAM or
NGHTTP2_FLAG_END_SEGMENT even if the sent chunk is not the end of
the stream */
if(!pdata->eof) {
frame->hd.flags &= ~(NGHTTP2_FLAG_END_STREAM | NGHTTP2_FLAG_END_SEGMENT);
}
}
size_t nghttp2_frame_trail_padlen(nghttp2_frame *frame, size_t padlen)
{
return padlen
- ((frame->hd.flags & NGHTTP2_FLAG_PAD_HIGH) > 0)
- ((frame->hd.flags & NGHTTP2_FLAG_PAD_LOW) > 0);
}
void nghttp2_frame_private_data_init(nghttp2_private_data *frame,
uint8_t flags,
int32_t stream_id,
const nghttp2_data_provider *data_prd)
{
/* At this moment, the length of DATA frame is unknown */
nghttp2_frame_set_hd(&frame->hd, 0, NGHTTP2_DATA, flags, stream_id);
frame->data_prd = *data_prd;
frame->padlen = 0;
frame->eof = 0;
}
void nghttp2_frame_private_data_free(nghttp2_private_data *frame)
{}
size_t nghttp2_frame_headers_payload_nv_offset(nghttp2_headers *frame)
{
if(frame->hd.flags & NGHTTP2_FLAG_PRIORITY) {
return 4;
} else {
return 0;
}
}
/*
* Call this function after payload was serialized, but not before
* changing buf->pos and serializing frame header.
*
* This function assumes bufs->cur points to the last buf chain of the
* frame(s).
*
* This function serializes frame header for HEADERS/PUSH_PROMISE and
* handles their successive CONTINUATION frames.
*
* We don't process any padding here.
*/
static int frame_pack_headers_shared(nghttp2_bufs *bufs,
nghttp2_frame_hd *frame_hd)
{
nghttp2_buf *buf;
nghttp2_buf_chain *ci, *ce;
nghttp2_frame_hd hd;
buf = &bufs->head->buf;
hd = *frame_hd;
hd.length = nghttp2_buf_len(buf);
DEBUGF(fprintf(stderr,
"send: HEADERS/PUSH_PROMISE, payloadlen=%zu\n", hd.length));
/* We have multiple frame buffers, which means one or more
CONTINUATION frame is involved. Remove END_HEADERS flag from the
first frame. */
if(bufs->head != bufs->cur) {
hd.flags &= ~NGHTTP2_FLAG_END_HEADERS;
}
buf->pos -= NGHTTP2_FRAME_HDLEN;
nghttp2_frame_pack_frame_hd(buf->pos, &hd);
if(bufs->head != bufs->cur) {
/* 2nd and later frames are CONTINUATION frames. */
hd.type = NGHTTP2_CONTINUATION;
/* We don't have no flags except for last CONTINUATION */
hd.flags = NGHTTP2_FLAG_NONE;
ce = bufs->cur;
for(ci = bufs->head->next; ci != ce; ci = ci->next) {
buf = &ci->buf;
hd.length = nghttp2_buf_len(buf);
DEBUGF(fprintf(stderr,
"send: int CONTINUATION, payloadlen=%zu\n", hd.length));
buf->pos -= NGHTTP2_FRAME_HDLEN;
nghttp2_frame_pack_frame_hd(buf->pos, &hd);
}
buf = &ci->buf;
hd.length = nghttp2_buf_len(buf);
/* Set END_HEADERS flag for last CONTINUATION */
hd.flags = NGHTTP2_FLAG_END_HEADERS;
DEBUGF(fprintf(stderr,
"send: last CONTINUATION, payloadlen=%zu\n", hd.length));
buf->pos -= NGHTTP2_FRAME_HDLEN;
nghttp2_frame_pack_frame_hd(buf->pos, &hd);
}
return 0;
}
int nghttp2_frame_pack_headers(nghttp2_bufs *bufs,
nghttp2_headers *frame,
nghttp2_hd_deflater *deflater)
{
size_t nv_offset;
ssize_t rv;
nghttp2_buf *buf;
assert(bufs->head == bufs->cur);
nv_offset = nghttp2_frame_headers_payload_nv_offset(frame);
buf = &bufs->cur->buf;
buf->pos += nv_offset;
buf->last = buf->pos;
/* This call will adjust buf->last to the correct position */
rv = nghttp2_hd_deflate_hd(deflater, bufs, frame->nva, frame->nvlen);
buf->pos -= nv_offset;
if(rv != 0) {
return rv;
}
if(frame->hd.flags & NGHTTP2_FLAG_PRIORITY) {
nghttp2_put_uint32be(buf->pos, frame->pri);
}
frame->padlen = 0;
frame->hd.length = nghttp2_bufs_len(bufs);
return frame_pack_headers_shared(bufs, &frame->hd);
}
int nghttp2_frame_unpack_headers_payload(nghttp2_headers *frame,
const uint8_t *payload,
size_t payloadlen)
{
if(frame->hd.flags & NGHTTP2_FLAG_PRIORITY) {
frame->pri = nghttp2_get_uint32(payload) & NGHTTP2_PRIORITY_MASK;
} else {
frame->pri = NGHTTP2_PRI_DEFAULT;
}
frame->nva = NULL;
frame->nvlen = 0;
return 0;
}
int nghttp2_frame_pack_priority(nghttp2_bufs *bufs, nghttp2_priority *frame)
{
nghttp2_buf *buf;
assert(bufs->head == bufs->cur);
buf = &bufs->head->buf;
buf->pos -= NGHTTP2_FRAME_HDLEN;
nghttp2_frame_pack_frame_hd(buf->pos, &frame->hd);
nghttp2_put_uint32be(buf->last, frame->pri);
buf->last += 4;
return 0;
}
void nghttp2_frame_unpack_priority_payload(nghttp2_priority *frame,
const uint8_t *payload,
size_t payloadlen)
{
frame->pri = nghttp2_get_uint32(payload) & NGHTTP2_PRIORITY_MASK;
}
int nghttp2_frame_pack_rst_stream(nghttp2_bufs *bufs,
nghttp2_rst_stream *frame)
{
nghttp2_buf *buf;
assert(bufs->head == bufs->cur);
buf = &bufs->head->buf;
buf->pos -= NGHTTP2_FRAME_HDLEN;
nghttp2_frame_pack_frame_hd(buf->pos, &frame->hd);
nghttp2_put_uint32be(buf->last, frame->error_code);
buf->last += 4;
return 0;
}
void nghttp2_frame_unpack_rst_stream_payload(nghttp2_rst_stream *frame,
const uint8_t *payload,
size_t payloadlen)
{
frame->error_code = nghttp2_get_uint32(payload);
}
int nghttp2_frame_pack_settings(nghttp2_bufs *bufs, nghttp2_settings *frame)
{
nghttp2_buf *buf;
assert(bufs->head == bufs->cur);
buf = &bufs->head->buf;
if(nghttp2_buf_avail(buf) < (ssize_t)frame->hd.length) {
return NGHTTP2_ERR_FRAME_SIZE_ERROR;
}
buf->pos -= NGHTTP2_FRAME_HDLEN;
nghttp2_frame_pack_frame_hd(buf->pos, &frame->hd);
buf->last += nghttp2_frame_pack_settings_payload(buf->last,
frame->iv, frame->niv);
return 0;
}
size_t nghttp2_frame_pack_settings_payload(uint8_t *buf,
const nghttp2_settings_entry *iv,
size_t niv)
{
size_t i;
for(i = 0; i < niv; ++i, buf += NGHTTP2_FRAME_SETTINGS_ENTRY_LENGTH) {
buf[0] = iv[i].settings_id;
nghttp2_put_uint32be(buf + 1, iv[i].value);
}
return NGHTTP2_FRAME_SETTINGS_ENTRY_LENGTH * niv;
}
int nghttp2_frame_unpack_settings_payload(nghttp2_settings *frame,
nghttp2_settings_entry *iv,
size_t niv)
{
size_t payloadlen = niv * sizeof(nghttp2_settings_entry);
frame->iv = malloc(payloadlen);
if(frame->iv == NULL) {
return NGHTTP2_ERR_NOMEM;
}
memcpy(frame->iv, iv, payloadlen);
frame->niv = niv;
return 0;
}
void nghttp2_frame_unpack_settings_entry(nghttp2_settings_entry *iv,
const uint8_t *payload)
{
iv->settings_id = payload[0];
iv->value = nghttp2_get_uint32(&payload[1]);
}
int nghttp2_frame_unpack_settings_payload2(nghttp2_settings_entry **iv_ptr,
size_t *niv_ptr,
const uint8_t *payload,
size_t payloadlen)
{
size_t i;
*niv_ptr = payloadlen / NGHTTP2_FRAME_SETTINGS_ENTRY_LENGTH;
*iv_ptr = malloc((*niv_ptr)*sizeof(nghttp2_settings_entry));
if(*iv_ptr == NULL) {
return NGHTTP2_ERR_NOMEM;
}
for(i = 0; i < *niv_ptr; ++i) {
size_t off = i * NGHTTP2_FRAME_SETTINGS_ENTRY_LENGTH;
nghttp2_frame_unpack_settings_entry(&(*iv_ptr)[i], &payload[off]);
}
return 0;
}
int nghttp2_frame_pack_push_promise(nghttp2_bufs *bufs,
nghttp2_push_promise *frame,
nghttp2_hd_deflater *deflater)
{
size_t nv_offset = 4;
ssize_t rv;
nghttp2_buf *buf;
assert(bufs->head == bufs->cur);
buf = &bufs->cur->buf;
buf->pos += nv_offset;
buf->last = buf->pos;
/* This call will adjust buf->last to the correct position */
rv = nghttp2_hd_deflate_hd(deflater, bufs, frame->nva, frame->nvlen);
buf->pos -= nv_offset;
if(rv != 0) {
return rv;
}
nghttp2_put_uint32be(buf->pos, frame->promised_stream_id);
frame->padlen = 0;
frame->hd.length = nghttp2_bufs_len(bufs);
return frame_pack_headers_shared(bufs, &frame->hd);
}
int nghttp2_frame_unpack_push_promise_payload(nghttp2_push_promise *frame,
const uint8_t *payload,
size_t payloadlen)
{
frame->promised_stream_id = nghttp2_get_uint32(payload) &
NGHTTP2_STREAM_ID_MASK;
frame->nva = NULL;
frame->nvlen = 0;
return 0;
}
int nghttp2_frame_pack_ping(nghttp2_bufs *bufs, nghttp2_ping *frame)
{
nghttp2_buf *buf;
assert(bufs->head == bufs->cur);
buf = &bufs->head->buf;
buf->pos -= NGHTTP2_FRAME_HDLEN;
nghttp2_frame_pack_frame_hd(buf->pos, &frame->hd);
buf->last = nghttp2_cpymem(buf->last, frame->opaque_data,
sizeof(frame->opaque_data));
return 0;
}
void nghttp2_frame_unpack_ping_payload(nghttp2_ping *frame,
const uint8_t *payload,
size_t payloadlen)
{
memcpy(frame->opaque_data, payload, sizeof(frame->opaque_data));
}
int nghttp2_frame_pack_goaway(nghttp2_bufs *bufs, nghttp2_goaway *frame)
{
int rv;
nghttp2_buf *buf;
assert(bufs->head == bufs->cur);
buf = &bufs->head->buf;
buf->pos -= NGHTTP2_FRAME_HDLEN;
nghttp2_frame_pack_frame_hd(buf->pos, &frame->hd);
nghttp2_put_uint32be(buf->last, frame->last_stream_id);
buf->last += 4;
nghttp2_put_uint32be(buf->last, frame->error_code);
buf->last += 4;
rv = nghttp2_bufs_add(bufs, frame->opaque_data, frame->opaque_data_len);
if(rv != 0) {
return rv;
}
return 0;
}
void nghttp2_frame_unpack_goaway_payload(nghttp2_goaway *frame,
const uint8_t *payload,
size_t payloadlen)
{
frame->last_stream_id = nghttp2_get_uint32(payload) & NGHTTP2_STREAM_ID_MASK;
frame->error_code = nghttp2_get_uint32(payload+4);
/* TODO Currently we don't buffer debug data */
frame->opaque_data = NULL;
frame->opaque_data_len = 0;
}
int nghttp2_frame_pack_window_update(nghttp2_bufs *bufs,
nghttp2_window_update *frame)
{
nghttp2_buf *buf;
assert(bufs->head == bufs->cur);
buf = &bufs->head->buf;
buf->pos -= NGHTTP2_FRAME_HDLEN;
nghttp2_frame_pack_frame_hd(buf->pos, &frame->hd);
nghttp2_put_uint32be(buf->last, frame->window_size_increment);
buf->last += 4;
return 0;
}
void nghttp2_frame_unpack_window_update_payload(nghttp2_window_update *frame,
const uint8_t *payload,
size_t payloadlen)
{
frame->window_size_increment = nghttp2_get_uint32(payload) &
NGHTTP2_WINDOW_SIZE_INCREMENT_MASK;
}
nghttp2_settings_entry* nghttp2_frame_iv_copy(const nghttp2_settings_entry *iv,
size_t niv)
{
nghttp2_settings_entry *iv_copy;
size_t len = niv*sizeof(nghttp2_settings_entry);
iv_copy = malloc(len);
if(iv_copy == NULL) {
return NULL;
}
memcpy(iv_copy, iv, len);
return iv_copy;
}
int nghttp2_nv_equal(const nghttp2_nv *a, const nghttp2_nv *b)
{
return a->namelen == b->namelen && a->valuelen == b->valuelen &&
memcmp(a->name, b->name, a->namelen) == 0 &&
memcmp(a->value, b->value, a->valuelen) == 0;
}
void nghttp2_nv_array_del(nghttp2_nv *nva)
{
free(nva);
}
static int bytes_compar(const uint8_t *a, size_t alen,
const uint8_t *b, size_t blen)
{
if(alen == blen) {
return memcmp(a, b, alen);
} else if(alen < blen) {
int rv = memcmp(a, b, alen);
if(rv == 0) {
return -1;
} else {
return rv;
}
} else {
int rv = memcmp(a, b, blen);
if(rv == 0) {
return 1;
} else {
return rv;
}
}
}
int nghttp2_nv_compare_name(const nghttp2_nv *lhs, const nghttp2_nv *rhs)
{
return bytes_compar(lhs->name, lhs->namelen, rhs->name, rhs->namelen);
}
static int nv_compar(const void *lhs, const void *rhs)
{
const nghttp2_nv *a = (const nghttp2_nv*)lhs;
const nghttp2_nv *b = (const nghttp2_nv*)rhs;
int rv;
rv = bytes_compar(a->name, a->namelen, b->name, b->namelen);
if(rv == 0) {
return bytes_compar(a->value, a->valuelen, b->value, b->valuelen);
}
return rv;
}
void nghttp2_nv_array_sort(nghttp2_nv *nva, size_t nvlen)
{
qsort(nva, nvlen, sizeof(nghttp2_nv), nv_compar);
}
ssize_t nghttp2_nv_array_copy(nghttp2_nv **nva_ptr,
const nghttp2_nv *nva, size_t nvlen)
{
size_t i;
uint8_t *data;
size_t buflen = 0;
nghttp2_nv *p;
for(i = 0; i < nvlen; ++i) {
buflen += nva[i].namelen + nva[i].valuelen;
}
/* If all name/value pair is 0-length, remove them */
if(nvlen == 0 || buflen == 0) {
*nva_ptr = NULL;
return 0;
}
buflen += sizeof(nghttp2_nv)*nvlen;
*nva_ptr = malloc(buflen);
if(*nva_ptr == NULL) {
return NGHTTP2_ERR_NOMEM;
}
p = *nva_ptr;
data = (uint8_t*)(*nva_ptr) + sizeof(nghttp2_nv)*nvlen;
for(i = 0; i < nvlen; ++i) {
memcpy(data, nva[i].name, nva[i].namelen);
p->name = data;
p->namelen = nva[i].namelen;
nghttp2_downcase(p->name, p->namelen);
data += nva[i].namelen;
memcpy(data, nva[i].value, nva[i].valuelen);
p->value = data;
p->valuelen = nva[i].valuelen;
data += nva[i].valuelen;
++p;
}
return nvlen;
}
int nghttp2_iv_check(const nghttp2_settings_entry *iv, size_t niv)
{
size_t i;
for(i = 0; i < niv; ++i) {
switch(iv[i].settings_id) {
case NGHTTP2_SETTINGS_HEADER_TABLE_SIZE:
case NGHTTP2_SETTINGS_MAX_CONCURRENT_STREAMS:
break;
case NGHTTP2_SETTINGS_ENABLE_PUSH:
if(iv[i].value != 0 && iv[i].value != 1) {
return 0;
}
break;
case NGHTTP2_SETTINGS_INITIAL_WINDOW_SIZE:
if(iv[i].value > (uint32_t)NGHTTP2_MAX_WINDOW_SIZE) {
return 0;
}
break;
default:
return 0;
}
}
return 1;
}
static void frame_set_pad(nghttp2_buf *buf, size_t padlen)
{
size_t trail_padlen;
if(padlen > 256) {
DEBUGF(fprintf(stderr, "send: padlen=%zu, shift left 2 bytes\n", padlen));
memmove(buf->pos - 2, buf->pos, NGHTTP2_FRAME_HDLEN);
buf->pos -= 2;
buf->pos[3] |= NGHTTP2_FLAG_PAD_HIGH | NGHTTP2_FLAG_PAD_LOW;
nghttp2_put_uint16be(buf->pos, nghttp2_get_uint16(buf->pos) + padlen);
trail_padlen = padlen - 2;
buf->pos[NGHTTP2_FRAME_HDLEN] = trail_padlen >> 8;
buf->pos[NGHTTP2_FRAME_HDLEN + 1] = trail_padlen & 0xff;
} else if(padlen > 0) {
DEBUGF(fprintf(stderr, "send: padlen=%zu, shift left 1 bytes\n", padlen));
memmove(buf->pos - 1, buf->pos, NGHTTP2_FRAME_HDLEN);
--buf->pos;
buf->pos[3] |= NGHTTP2_FLAG_PAD_LOW;
nghttp2_put_uint16be(buf->pos, nghttp2_get_uint16(buf->pos) + padlen);
trail_padlen = padlen - 1;
buf->pos[NGHTTP2_FRAME_HDLEN] = trail_padlen;
} else {
DEBUGF(fprintf(stderr, "send: padlen=0, no shift left was made\n"));
return;
}
/* zero out padding */
memset(buf->last, 0, trail_padlen);
/* extend buffers trail_padlen bytes, since we ate previous padlen -
trail_padlen byte(s) */
buf->last += trail_padlen;
return;
}
int nghttp2_frame_add_pad(nghttp2_bufs *bufs, nghttp2_frame_hd *hd,
size_t padlen, nghttp2_frame_type type)
{
int rv;
size_t trail_padlen;
size_t last_avail;
nghttp2_buf *buf;
nghttp2_frame_hd last_hd;
if(padlen == 0) {
DEBUGF(fprintf(stderr, "send: padlen = 0, nothing to do\n"));
return 0;
}
/*
* We have arranged bufs like this:
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | | |Frame header | Frame payload... |
* +-+-+---------------+-------------------------------------------+
* | | |Frame header | Frame payload... |
* +-+-+---------------+-------------------------------------------+
* | | |Frame header | Frame payload... |
* +-+-+---------------+-------------------------------------------+
*
* Since we limit the length of the padding bytes, they are
* completely included in one frame payload or across 2 frames. We
* are going to adjust buf->pos of frame which includes part of
* padding. And serialize (memmove) frame header in the correct
* position. Also extends buf->last to include padding.
*/
nghttp2_bufs_seek_last_present(bufs);
buf = &bufs->cur->buf;
last_avail = nghttp2_buf_avail(buf);
if(last_avail >= padlen) {
/* Last frame can include all paddings bytes */
DEBUGF(fprintf(stderr, "send: last frame includes all paddings\n"));
frame_set_pad(buf, padlen);
} else {
/* padding across 2 frames */
/* type = DATA must not be here */
assert(type == NGHTTP2_CONTINUATION);
/* This will seek to the last chain */
rv = nghttp2_bufs_advance(bufs);
if(rv == NGHTTP2_ERR_BUFFER_ERROR) {
return NGHTTP2_ERR_FRAME_SIZE_ERROR;
}
if(rv != 0) {
return rv;
}
if(type == NGHTTP2_CONTINUATION) {
/* former last frame has END_HEADERS flag set. Clear it. */
buf->pos[3] &= ~NGHTTP2_FLAG_END_HEADERS;
}
trail_padlen = nghttp2_buf_avail(buf);
/* former last frame may have zero buffer available */
if(trail_padlen == 0) {
DEBUGF(fprintf(stderr,
"send: last frame has no space to include padding\n"));
} else {
DEBUGF(fprintf(stderr, "send: padding across 2 frames\n"));
frame_set_pad(buf, trail_padlen);
}
/* This buffer does not have frame header serialized */
buf = &bufs->cur->buf;
trail_padlen = padlen - trail_padlen;
last_hd.length = 0;
last_hd.type = type;
last_hd.stream_id = hd->stream_id;
if(type == NGHTTP2_CONTINUATION) {
last_hd.flags = NGHTTP2_FLAG_END_HEADERS;
} else {
last_hd.flags = NGHTTP2_FLAG_NONE;
}
buf->pos -= NGHTTP2_FRAME_HDLEN;
nghttp2_frame_pack_frame_hd(buf->pos, &last_hd);
frame_set_pad(buf, trail_padlen);
}
hd->length += padlen;
DEBUGF(fprintf(stderr, "send: final payloadlen=%zu, padlen=%zu\n",
hd->length, padlen));
return 0;
}
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