HTTP/2: fixed splitting of response headers on CONTINUATION frames.

Previous code has been based on assumption that the header block can only be
splitted at the borders of individual headers.  That wasn't the case and might
result in emitting frames bigger than the frame size limit.

The current approach is to split header blocks by the frame size limit.
This commit is contained in:
Valentin Bartenev 2015-09-28 02:32:44 +03:00
parent 60e41c0fb1
commit 9150c7df1f

View File

@ -43,10 +43,8 @@
static u_char *ngx_http_v2_write_int(u_char *pos, ngx_uint_t prefix,
ngx_uint_t value);
static void ngx_http_v2_write_headers_head(u_char *pos, size_t length,
ngx_uint_t sid, ngx_uint_t end_headers, ngx_uint_t end_stream);
static void ngx_http_v2_write_continuation_head(u_char *pos, size_t length,
ngx_uint_t sid, ngx_uint_t end_headers);
static ngx_http_v2_out_frame_t *ngx_http_v2_create_headers_frame(
ngx_http_request_t *r, u_char *pos, u_char *end);
static ngx_chain_t *ngx_http_v2_send_chain(ngx_connection_t *fc,
ngx_chain_t *in, off_t limit);
@ -116,17 +114,14 @@ static ngx_http_output_header_filter_pt ngx_http_next_header_filter;
static ngx_int_t
ngx_http_v2_header_filter(ngx_http_request_t *r)
{
u_char status, *p, *head;
size_t len, rest, frame_size;
ngx_buf_t *b;
u_char status, *pos, *start, *p;
size_t len;
ngx_str_t host, location;
ngx_uint_t i, port, continuation;
ngx_chain_t *cl;
ngx_uint_t i, port;
ngx_list_part_t *part;
ngx_table_elt_t *header;
ngx_connection_t *fc;
ngx_http_cleanup_t *cln;
ngx_http_v2_stream_t *stream;
ngx_http_v2_out_frame_t *frame;
ngx_http_core_loc_conf_t *clcf;
ngx_http_core_srv_conf_t *cscf;
@ -388,84 +383,75 @@ ngx_http_v2_header_filter(ngx_http_request_t *r)
+ NGX_HTTP_V2_INT_OCTETS + header[i].value.len;
}
stream = r->stream;
frame_size = stream->connection->frame_size;
len += NGX_HTTP_V2_FRAME_HEADER_SIZE
* ((len + frame_size - 1) / frame_size);
b = ngx_create_temp_buf(r->pool, len);
if (b == NULL) {
pos = ngx_palloc(r->pool, len);
if (pos == NULL) {
return NGX_ERROR;
}
b->last_buf = r->header_only;
b->last += NGX_HTTP_V2_FRAME_HEADER_SIZE;
start = pos;
if (status) {
*b->last++ = status;
*pos++ = status;
} else {
*b->last++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_STATUS_INDEX);
*b->last++ = NGX_HTTP_V2_ENCODE_RAW | 3;
b->last = ngx_sprintf(b->last, "%03ui", r->headers_out.status);
*pos++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_STATUS_INDEX);
*pos++ = NGX_HTTP_V2_ENCODE_RAW | 3;
pos = ngx_sprintf(pos, "%03ui", r->headers_out.status);
}
if (r->headers_out.server == NULL) {
*b->last++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_SERVER_INDEX);
*pos++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_SERVER_INDEX);
if (clcf->server_tokens) {
*b->last++ = NGX_HTTP_V2_ENCODE_RAW | (sizeof(NGINX_VER) - 1);
b->last = ngx_cpymem(b->last, NGINX_VER, sizeof(NGINX_VER) - 1);
*pos++ = NGX_HTTP_V2_ENCODE_RAW | (sizeof(NGINX_VER) - 1);
pos = ngx_cpymem(pos, NGINX_VER, sizeof(NGINX_VER) - 1);
} else {
*b->last++ = NGX_HTTP_V2_ENCODE_RAW | (sizeof("nginx") - 1);
b->last = ngx_cpymem(b->last, "nginx", sizeof("nginx") - 1);
*pos++ = NGX_HTTP_V2_ENCODE_RAW | (sizeof("nginx") - 1);
pos = ngx_cpymem(pos, "nginx", sizeof("nginx") - 1);
}
}
if (r->headers_out.date == NULL) {
*b->last++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_DATE_INDEX);
*b->last++ = (u_char) ngx_cached_http_time.len;
*pos++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_DATE_INDEX);
*pos++ = (u_char) ngx_cached_http_time.len;
b->last = ngx_cpymem(b->last, ngx_cached_http_time.data,
pos = ngx_cpymem(pos, ngx_cached_http_time.data,
ngx_cached_http_time.len);
}
if (r->headers_out.content_type.len) {
*b->last++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_CONTENT_TYPE_INDEX);
*pos++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_CONTENT_TYPE_INDEX);
if (r->headers_out.content_type_len == r->headers_out.content_type.len
&& r->headers_out.charset.len)
{
*b->last = NGX_HTTP_V2_ENCODE_RAW;
b->last = ngx_http_v2_write_int(b->last, ngx_http_v2_prefix(7),
*pos = NGX_HTTP_V2_ENCODE_RAW;
pos = ngx_http_v2_write_int(pos, ngx_http_v2_prefix(7),
r->headers_out.content_type.len
+ sizeof("; charset=") - 1
+ r->headers_out.charset.len);
p = b->last;
p = pos;
b->last = ngx_cpymem(p, r->headers_out.content_type.data,
pos = ngx_cpymem(pos, r->headers_out.content_type.data,
r->headers_out.content_type.len);
b->last = ngx_cpymem(b->last, "; charset=",
sizeof("; charset=") - 1);
pos = ngx_cpymem(pos, "; charset=", sizeof("; charset=") - 1);
b->last = ngx_cpymem(b->last, r->headers_out.charset.data,
pos = ngx_cpymem(pos, r->headers_out.charset.data,
r->headers_out.charset.len);
/* update r->headers_out.content_type for possible logging */
r->headers_out.content_type.len = b->last - p;
r->headers_out.content_type.len = pos - p;
r->headers_out.content_type.data = p;
} else {
*b->last = NGX_HTTP_V2_ENCODE_RAW;
b->last = ngx_http_v2_write_int(b->last, ngx_http_v2_prefix(7),
*pos = NGX_HTTP_V2_ENCODE_RAW;
pos = ngx_http_v2_write_int(pos, ngx_http_v2_prefix(7),
r->headers_out.content_type.len);
b->last = ngx_cpymem(b->last, r->headers_out.content_type.data,
pos = ngx_cpymem(pos, r->headers_out.content_type.data,
r->headers_out.content_type.len);
}
}
@ -473,49 +459,41 @@ ngx_http_v2_header_filter(ngx_http_request_t *r)
if (r->headers_out.content_length == NULL
&& r->headers_out.content_length_n >= 0)
{
*b->last++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_CONTENT_LENGTH_INDEX);
*pos++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_CONTENT_LENGTH_INDEX);
p = b->last;
b->last = ngx_sprintf(b->last + 1, "%O",
r->headers_out.content_length_n);
*p = NGX_HTTP_V2_ENCODE_RAW | (u_char) (b->last - p - 1);
p = pos;
pos = ngx_sprintf(pos + 1, "%O", r->headers_out.content_length_n);
*p = NGX_HTTP_V2_ENCODE_RAW | (u_char) (pos - p - 1);
}
if (r->headers_out.last_modified == NULL
&& r->headers_out.last_modified_time != -1)
{
*b->last++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_LAST_MODIFIED_INDEX);
*pos++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_LAST_MODIFIED_INDEX);
*b->last++ = NGX_HTTP_V2_ENCODE_RAW
*pos++ = NGX_HTTP_V2_ENCODE_RAW
| (sizeof("Wed, 31 Dec 1986 18:00:00 GMT") - 1);
b->last = ngx_http_time(b->last, r->headers_out.last_modified_time);
pos = ngx_http_time(pos, r->headers_out.last_modified_time);
}
if (r->headers_out.location && r->headers_out.location->value.len) {
*b->last++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_LOCATION_INDEX);
*pos++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_LOCATION_INDEX);
*b->last = NGX_HTTP_V2_ENCODE_RAW;
b->last = ngx_http_v2_write_int(b->last, ngx_http_v2_prefix(7),
*pos = NGX_HTTP_V2_ENCODE_RAW;
pos = ngx_http_v2_write_int(pos, ngx_http_v2_prefix(7),
r->headers_out.location->value.len);
b->last = ngx_cpymem(b->last, r->headers_out.location->value.data,
pos = ngx_cpymem(pos, r->headers_out.location->value.data,
r->headers_out.location->value.len);
}
#if (NGX_HTTP_GZIP)
if (r->gzip_vary) {
*b->last++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_VARY_INDEX);
*b->last++ = NGX_HTTP_V2_ENCODE_RAW | (sizeof("Accept-Encoding") - 1);
b->last = ngx_cpymem(b->last, "Accept-Encoding",
sizeof("Accept-Encoding") - 1);
*pos++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_VARY_INDEX);
*pos++ = NGX_HTTP_V2_ENCODE_RAW | (sizeof("Accept-Encoding") - 1);
pos = ngx_cpymem(pos, "Accept-Encoding", sizeof("Accept-Encoding") - 1);
}
#endif
continuation = 0;
head = b->pos;
len = b->last - head - NGX_HTTP_V2_FRAME_HEADER_SIZE;
rest = frame_size - len;
part = &r->headers_out.headers.part;
header = part->elts;
@ -535,82 +513,26 @@ ngx_http_v2_header_filter(ngx_http_request_t *r)
continue;
}
len = 1 + NGX_HTTP_V2_INT_OCTETS * 2
+ header[i].key.len
+ header[i].value.len;
*pos++ = 0;
if (len > rest) {
len = b->last - head - NGX_HTTP_V2_FRAME_HEADER_SIZE;
*pos = NGX_HTTP_V2_ENCODE_RAW;
pos = ngx_http_v2_write_int(pos, ngx_http_v2_prefix(7),
header[i].key.len);
ngx_strlow(pos, header[i].key.data, header[i].key.len);
pos += header[i].key.len;
if (continuation) {
ngx_http_v2_write_continuation_head(head, len,
stream->node->id, 0);
} else {
continuation = 1;
ngx_http_v2_write_headers_head(head, len, stream->node->id, 0,
r->header_only);
}
rest = frame_size;
head = b->last;
b->last += NGX_HTTP_V2_FRAME_HEADER_SIZE;
}
p = b->last;
*p++ = 0;
*p = NGX_HTTP_V2_ENCODE_RAW;
p = ngx_http_v2_write_int(p, ngx_http_v2_prefix(7), header[i].key.len);
ngx_strlow(p, header[i].key.data, header[i].key.len);
p += header[i].key.len;
*p = NGX_HTTP_V2_ENCODE_RAW;
p = ngx_http_v2_write_int(p, ngx_http_v2_prefix(7),
*pos = NGX_HTTP_V2_ENCODE_RAW;
pos = ngx_http_v2_write_int(pos, ngx_http_v2_prefix(7),
header[i].value.len);
p = ngx_cpymem(p, header[i].value.data, header[i].value.len);
rest -= p - b->last;
b->last = p;
pos = ngx_cpymem(pos, header[i].value.data, header[i].value.len);
}
len = b->last - head - NGX_HTTP_V2_FRAME_HEADER_SIZE;
if (continuation) {
ngx_http_v2_write_continuation_head(head, len, stream->node->id, 1);
} else {
ngx_http_v2_write_headers_head(head, len, stream->node->id, 1,
r->header_only);
}
cl = ngx_alloc_chain_link(r->pool);
if (cl == NULL) {
return NGX_ERROR;
}
cl->buf = b;
cl->next = NULL;
frame = ngx_palloc(r->pool, sizeof(ngx_http_v2_out_frame_t));
frame = ngx_http_v2_create_headers_frame(r, start, pos);
if (frame == NULL) {
return NGX_ERROR;
}
frame->first = cl;
frame->last = cl;
frame->handler = ngx_http_v2_headers_frame_handler;
frame->stream = stream;
frame->length = b->last - b->pos - NGX_HTTP_V2_FRAME_HEADER_SIZE;
frame->blocked = 1;
frame->fin = r->header_only;
ngx_log_debug3(NGX_LOG_DEBUG_HTTP, stream->request->connection->log, 0,
"http2:%ui create HEADERS frame %p: len:%uz",
stream->node->id, frame, frame->length);
ngx_http_v2_queue_blocked_frame(stream->connection, frame);
ngx_http_v2_queue_blocked_frame(r->stream->connection, frame);
cln = ngx_http_cleanup_add(r, 0);
if (cln == NULL) {
@ -618,14 +540,14 @@ ngx_http_v2_header_filter(ngx_http_request_t *r)
}
cln->handler = ngx_http_v2_filter_cleanup;
cln->data = stream;
cln->data = r->stream;
stream->queued = 1;
r->stream->queued = 1;
fc->send_chain = ngx_http_v2_send_chain;
fc->need_last_buf = 1;
return ngx_http_v2_filter_send(fc, stream);
return ngx_http_v2_filter_send(fc, r->stream);
}
@ -651,41 +573,104 @@ ngx_http_v2_write_int(u_char *pos, ngx_uint_t prefix, ngx_uint_t value)
}
static void
ngx_http_v2_write_headers_head(u_char *pos, size_t length, ngx_uint_t sid,
ngx_uint_t end_headers, ngx_uint_t end_stream)
static ngx_http_v2_out_frame_t *
ngx_http_v2_create_headers_frame(ngx_http_request_t *r, u_char *pos,
u_char *end)
{
u_char flags;
u_char type, flags;
size_t rest, frame_size;
ngx_buf_t *b;
ngx_chain_t *cl, **ll;
ngx_http_v2_stream_t *stream;
ngx_http_v2_out_frame_t *frame;
pos = ngx_http_v2_write_len_and_type(pos, length,
NGX_HTTP_V2_HEADERS_FRAME);
stream = r->stream;
rest = end - pos;
flags = NGX_HTTP_V2_NO_FLAG;
frame = ngx_palloc(r->pool, sizeof(ngx_http_v2_out_frame_t));
if (frame == NULL) {
return NULL;
}
if (end_headers) {
frame->handler = ngx_http_v2_headers_frame_handler;
frame->stream = stream;
frame->length = rest;
frame->blocked = 1;
frame->fin = r->header_only;
ll = &frame->first;
type = NGX_HTTP_V2_HEADERS_FRAME;
flags = r->header_only ? NGX_HTTP_V2_END_STREAM_FLAG : NGX_HTTP_V2_NO_FLAG;
frame_size = stream->connection->frame_size;
for ( ;; ) {
if (rest <= frame_size) {
frame_size = rest;
flags |= NGX_HTTP_V2_END_HEADERS_FLAG;
}
if (end_stream) {
flags |= NGX_HTTP_V2_END_STREAM_FLAG;
b = ngx_create_temp_buf(r->pool, NGX_HTTP_V2_FRAME_HEADER_SIZE);
if (b == NULL) {
return NULL;
}
*pos++ = flags;
b->last = ngx_http_v2_write_len_and_type(b->last, frame_size, type);
*b->last++ = flags;
b->last = ngx_http_v2_write_sid(b->last, stream->node->id);
(void) ngx_http_v2_write_sid(pos, sid);
cl = ngx_alloc_chain_link(r->pool);
if (cl == NULL) {
return NULL;
}
cl->buf = b;
static void
ngx_http_v2_write_continuation_head(u_char *pos, size_t length, ngx_uint_t sid,
ngx_uint_t end_headers)
{
pos = ngx_http_v2_write_len_and_type(pos, length,
NGX_HTTP_V2_CONTINUATION_FRAME);
*ll = cl;
ll = &cl->next;
*pos++ = end_headers ? NGX_HTTP_V2_END_HEADERS_FLAG : NGX_HTTP_V2_NO_FLAG;
b = ngx_calloc_buf(r->pool);
if (b == NULL) {
return NULL;
}
(void) ngx_http_v2_write_sid(pos, sid);
b->pos = pos;
pos += frame_size;
b->last = pos;
b->start = b->pos;
b->end = b->last;
b->temporary = 1;
cl = ngx_alloc_chain_link(r->pool);
if (cl == NULL) {
return NULL;
}
cl->buf = b;
*ll = cl;
ll = &cl->next;
rest -= frame_size;
if (rest) {
type = NGX_HTTP_V2_CONTINUATION_FRAME;
flags = NGX_HTTP_V2_NO_FLAG;
continue;
}
b->last_buf = r->header_only;
cl->next = NULL;
frame->last = cl;
ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"http2:%ui create HEADERS frame %p: len:%uz",
stream->node->id, frame, frame->length);
return frame;
}
}