static ngx_int_t
ngx_http_discard_request_body_filter(ngx_http_request_t *r, ngx_buf_t *b)
{
size_t size;
ngx_int_t rc;
ngx_http_request_body_t *rb;
if (r->headers_in.chunked) {
rb = r->request_body;
if (rb == NULL) {
rb = ngx_pcalloc(r->pool, sizeof(ngx_http_request_body_t));
if (rb == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
rb->chunked = ngx_pcalloc(r->pool, sizeof(ngx_http_chunked_t));
if (rb->chunked == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
r->request_body = rb;
}
for ( ;; ) {
rc = ngx_http_parse_chunked(r, b, rb->chunked);
if (rc == NGX_OK) {
/* a chunk has been parsed successfully */
size = b->last - b->pos;
if ((off_t) size > rb->chunked->size) {
b->pos += (size_t) rb->chunked->size;
rb->chunked->size = 0;
} else {
rb->chunked->size -= size;
b->pos = b->last;
}
continue;
}
if (rc == NGX_DONE) {
/* a whole response has been parsed successfully */
r->headers_in.content_length_n = 0;
break;
}
if (rc == NGX_AGAIN) {
/* set amount of data we want to see next time */
r->headers_in.content_length_n = rb->chunked->length;
break;
}
/* invalid */
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"client sent invalid chunked body");
return NGX_HTTP_BAD_REQUEST;
}
} else {
size = b->last - b->pos;
if ((off_t) size > r->headers_in.content_length_n) {
b->pos += (size_t) r->headers_in.content_length_n;
r->headers_in.content_length_n = 0;
} else {
b->pos = b->last;
r->headers_in.content_length_n -= size;
}
}
return NGX_OK;
}
static ngx_int_t
ngx_http_request_body_chunked_filter(ngx_http_request_t *r, ngx_chain_t *in)
{
size_t size;
ngx_int_t rc;
ngx_buf_t *b;
ngx_chain_t *cl, *out, *tl, **ll;
ngx_http_request_body_t *rb;
ngx_http_core_loc_conf_t *clcf;
rb = r->request_body;
if (rb->rest == -1) {
ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
"http request body chunked filter");
rb->chunked = ngx_pcalloc(r->pool, sizeof(ngx_http_chunked_t));
if (rb->chunked == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
r->headers_in.content_length_n = 0;
rb->rest = 3;
}
out = NULL;
ll = &out;
for (cl = in; cl; cl = cl->next) {
for ( ;; ) {
ngx_log_debug7(NGX_LOG_DEBUG_EVENT, r->connection->log, 0,
"http body chunked buf "
"t:%d f:%d %p, pos %p, size: %z file: %O, size: %O",
cl->buf->temporary, cl->buf->in_file,
cl->buf->start, cl->buf->pos,
cl->buf->last - cl->buf->pos,
cl->buf->file_pos,
cl->buf->file_last - cl->buf->file_pos);
rc = ngx_http_parse_chunked(r, cl->buf, rb->chunked);
if (rc == NGX_OK) {
/* a chunk has been parsed successfully */
clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
if (clcf->client_max_body_size
&& clcf->client_max_body_size
- r->headers_in.content_length_n < rb->chunked->size)
{
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"client intended to send too large chunked "
"body: %O+%O bytes",
r->headers_in.content_length_n,
rb->chunked->size);
r->lingering_close = 1;
return NGX_HTTP_REQUEST_ENTITY_TOO_LARGE;
}
tl = ngx_chain_get_free_buf(r->pool, &rb->free);
if (tl == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
b = tl->buf;
ngx_memzero(b, sizeof(ngx_buf_t));
b->temporary = 1;
b->tag = (ngx_buf_tag_t) &ngx_http_read_client_request_body;
b->start = cl->buf->pos;
b->pos = cl->buf->pos;
b->last = cl->buf->last;
b->end = cl->buf->end;
b->flush = r->request_body_no_buffering;
*ll = tl;
ll = &tl->next;
size = cl->buf->last - cl->buf->pos;
if ((off_t) size > rb->chunked->size) {
cl->buf->pos += (size_t) rb->chunked->size;
r->headers_in.content_length_n += rb->chunked->size;
rb->chunked->size = 0;
} else {
rb->chunked->size -= size;
r->headers_in.content_length_n += size;
cl->buf->pos = cl->buf->last;
}
b->last = cl->buf->pos;
continue;
}
if (rc == NGX_DONE) {
/* a whole response has been parsed successfully */
rb->rest = 0;
tl = ngx_chain_get_free_buf(r->pool, &rb->free);
if (tl == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
b = tl->buf;
ngx_memzero(b, sizeof(ngx_buf_t));
b->last_buf = 1;
*ll = tl;
ll = &tl->next;
break;
}
if (rc == NGX_AGAIN) {
/* set rb->rest, amount of data we want to see next time */
rb->rest = rb->chunked->length;
break;
}
/* invalid */
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"client sent invalid chunked body");
return NGX_HTTP_BAD_REQUEST;
}
}
rc = ngx_http_top_request_body_filter(r, out);
ngx_chain_update_chains(r->pool, &rb->free, &rb->busy, &out,
(ngx_buf_tag_t) &ngx_http_read_client_request_body);
return rc;
}
// 检查请求结构体里的缓冲区数据，丢弃
// 有content_length_n指定确切长度，那么只接收，不处理，移动缓冲区指针
// chunked数据需要解析数据
// content_length_n==0表示数据已经全部读完
// 就已经完成了丢弃任务，否则就要加入epoll读事件继续读
static ngx_int_t
ngx_http_discard_request_body_filter(ngx_http_request_t *r, ngx_buf_t *b)
{
size_t size;
ngx_int_t rc;
ngx_http_request_body_t *rb;
// chunked数据长度不确定，需要特殊处理
if (r->headers_in.chunked) {
// 获取专门的请求体数据结构
rb = r->request_body;
// 如果还没有就创建
if (rb == NULL) {
rb = ngx_pcalloc(r->pool, sizeof(ngx_http_request_body_t));
if (rb == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
rb->chunked = ngx_pcalloc(r->pool, sizeof(ngx_http_chunked_t));
if (rb->chunked == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
r->request_body = rb;
}
for ( ;; ) {
// in ngx_http_parse.c
// 解析chunked数据
rc = ngx_http_parse_chunked(r, b, rb->chunked);
// ok表示一个chunk解析完成
if (rc == NGX_OK) {
/* a chunk has been parsed successfully */
// 计算实际数据的长度
size = b->last - b->pos;
// 实际长度大于chunk长度，可能有下一个的数据已经读了
if ((off_t) size > rb->chunked->size) {
// 移动缓冲区指针，消费读取的chunk数据
b->pos += (size_t) rb->chunked->size;
// chunk长度归0
rb->chunked->size = 0;
} else {
// chunk数据不完整，没读取完
// 减去已经读取的长度，剩下的就是还要读取的长度
rb->chunked->size -= size;
b->pos = b->last;
}
// 继续解析读取的数据，直至非ok
continue;
}
// done所有的chunk数据均读取完毕
// content_length_n置0，表示无数据，丢弃成功
if (rc == NGX_DONE) {
/* a whole response has been parsed successfully */
r->headers_in.content_length_n = 0;
break;
}
// again表示数据不完整，需要继续读取
if (rc == NGX_AGAIN) {
/* set amount of data we want to see next time */
r->headers_in.content_length_n = rb->chunked->length;
break;
}
/* invalid */
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
"client sent invalid chunked body");
return NGX_HTTP_BAD_REQUEST;
}
} else {
// 不是chunked，请求体数据有确定的长度
// 检查缓冲区里头之后的数据，即收到的请求体数据
size = b->last - b->pos;
// 收到的数据大于头里的content_length_n
if ((off_t) size > r->headers_in.content_length_n) {
// 缓冲区指针移动，即消费content_length_n的数据
b->pos += (size_t) r->headers_in.content_length_n;
// content_length_n置0，表示无数据，丢弃成功
r->headers_in.content_length_n = 0;
} else {
// 收到的数据不足，即还没有收完content_length_n字节数
// 如果正好收完，也是在这里处理
// 指针直接移动到最后，即消费所有收到的数据
b->pos = b->last;
// 头里的content_length_n减少，即还将要收多少数据
// 如果正好收完，那么值就是0，丢弃成功
r->headers_in.content_length_n -= size;
}
}
return NGX_OK;
}
