httpd/SOURCES/httpd-2.4.37-balancer-failover.patch
2021-10-08 11:47:23 +00:00

226 lines
10 KiB
Diff

diff --git a/modules/proxy/mod_proxy_http.c b/modules/proxy/mod_proxy_http.c
index ec1e042..2c0500f 100644
--- a/modules/proxy/mod_proxy_http.c
+++ b/modules/proxy/mod_proxy_http.c
@@ -310,16 +310,18 @@ static int stream_reqbody_read(proxy_http_req_t *req, apr_bucket_brigade *bb,
return OK;
}
-static int stream_reqbody(proxy_http_req_t *req, rb_methods rb_method)
+static int stream_reqbody(proxy_http_req_t *req)
{
request_rec *r = req->r;
int seen_eos = 0, rv = OK;
apr_size_t hdr_len;
char chunk_hdr[20]; /* must be here due to transient bucket. */
+ conn_rec *origin = req->origin;
proxy_conn_rec *p_conn = req->backend;
apr_bucket_alloc_t *bucket_alloc = req->bucket_alloc;
apr_bucket_brigade *header_brigade = req->header_brigade;
apr_bucket_brigade *input_brigade = req->input_brigade;
+ rb_methods rb_method = req->rb_method;
apr_off_t bytes, bytes_streamed = 0;
apr_bucket *e;
@@ -333,7 +335,7 @@ static int stream_reqbody(proxy_http_req_t *req, rb_methods rb_method)
}
if (!APR_BRIGADE_EMPTY(input_brigade)) {
- /* If this brigade contains EOS, either stop or remove it. */
+ /* If this brigade contains EOS, remove it and be done. */
if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) {
seen_eos = 1;
@@ -375,7 +377,8 @@ static int stream_reqbody(proxy_http_req_t *req, rb_methods rb_method)
APR_BRIGADE_INSERT_TAIL(input_brigade, e);
}
}
- else if (bytes_streamed > req->cl_val) {
+ else if (rb_method == RB_STREAM_CL
+ && bytes_streamed > req->cl_val) {
/* C-L < bytes streamed?!?
* We will error out after the body is completely
* consumed, but we can't stream more bytes at the
@@ -407,7 +410,7 @@ static int stream_reqbody(proxy_http_req_t *req, rb_methods rb_method)
APR_BRIGADE_PREPEND(input_brigade, header_brigade);
/* Flush here on EOS because we won't stream_reqbody_read() again */
- rv = ap_proxy_pass_brigade(bucket_alloc, r, p_conn, req->origin,
+ rv = ap_proxy_pass_brigade(bucket_alloc, r, p_conn, origin,
input_brigade, seen_eos);
if (rv != OK) {
return rv;
@@ -454,10 +457,6 @@ static int spool_reqbody_cl(proxy_http_req_t *req, apr_off_t *bytes_spooled)
/* If this brigade contains EOS, either stop or remove it. */
if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) {
seen_eos = 1;
-
- /* We can't pass this EOS to the output_filters. */
- e = APR_BRIGADE_LAST(input_brigade);
- apr_bucket_delete(e);
}
apr_brigade_length(input_brigade, 1, &bytes);
@@ -644,7 +643,18 @@ static int ap_proxy_http_prefetch(proxy_http_req_t *req,
*/
temp_brigade = apr_brigade_create(p, bucket_alloc);
block = req->prefetch_nonblocking ? APR_NONBLOCK_READ : APR_BLOCK_READ;
- do {
+
+ /* Account for saved input, if any. */
+ apr_brigade_length(input_brigade, 0, &bytes_read);
+
+ /* Ensure we don't hit a wall where we have a buffer too small
+ * for ap_get_brigade's filters to fetch us another bucket,
+ * surrender once we hit 80 bytes less than MAX_MEM_SPOOL
+ * (an arbitrary value).
+ */
+ while (bytes_read < MAX_MEM_SPOOL - 80
+ && (APR_BRIGADE_EMPTY(input_brigade)
+ || !APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade)))) {
status = ap_get_brigade(r->input_filters, temp_brigade,
AP_MODE_READBYTES, block,
MAX_MEM_SPOOL - bytes_read);
@@ -686,15 +696,7 @@ static int ap_proxy_http_prefetch(proxy_http_req_t *req,
c->client_ip, c->remote_host ? c->remote_host: "");
return HTTP_INTERNAL_SERVER_ERROR;
}
-
- /* Ensure we don't hit a wall where we have a buffer too small
- * for ap_get_brigade's filters to fetch us another bucket,
- * surrender once we hit 80 bytes less than MAX_MEM_SPOOL
- * (an arbitrary value.)
- */
- } while ((bytes_read < MAX_MEM_SPOOL - 80)
- && !APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))
- && !req->prefetch_nonblocking);
+ }
/* Use chunked request body encoding or send a content-length body?
*
@@ -838,35 +840,21 @@ static int ap_proxy_http_request(proxy_http_req_t *req)
{
int rv;
request_rec *r = req->r;
- apr_bucket_alloc_t *bucket_alloc = req->bucket_alloc;
- apr_bucket_brigade *header_brigade = req->header_brigade;
- apr_bucket_brigade *input_brigade = req->input_brigade;
/* send the request header/body, if any. */
switch (req->rb_method) {
+ case RB_SPOOL_CL:
case RB_STREAM_CL:
case RB_STREAM_CHUNKED:
if (req->do_100_continue) {
- rv = ap_proxy_pass_brigade(bucket_alloc, r, req->backend,
- req->origin, header_brigade, 1);
+ rv = ap_proxy_pass_brigade(req->bucket_alloc, r, req->backend,
+ req->origin, req->header_brigade, 1);
}
else {
- rv = stream_reqbody(req, req->rb_method);
+ rv = stream_reqbody(req);
}
break;
- case RB_SPOOL_CL:
- /* Prefetch has built the header and spooled the whole body;
- * if we don't expect 100-continue we can flush both all at once,
- * otherwise flush the header only.
- */
- if (!req->do_100_continue) {
- APR_BRIGADE_CONCAT(header_brigade, input_brigade);
- }
- rv = ap_proxy_pass_brigade(bucket_alloc, r, req->backend,
- req->origin, header_brigade, 1);
- break;
-
default:
/* shouldn't be possible */
rv = HTTP_INTERNAL_SERVER_ERROR;
@@ -1577,15 +1565,10 @@ int ap_proxy_http_process_response(proxy_http_req_t *req)
/* Send the request body (fully). */
switch(req->rb_method) {
+ case RB_SPOOL_CL:
case RB_STREAM_CL:
case RB_STREAM_CHUNKED:
- status = stream_reqbody(req, req->rb_method);
- break;
- case RB_SPOOL_CL:
- /* Prefetch has spooled the whole body, flush it. */
- status = ap_proxy_pass_brigade(req->bucket_alloc, r,
- backend, origin,
- req->input_brigade, 1);
+ status = stream_reqbody(req);
break;
default:
/* Shouldn't happen */
@@ -1940,6 +1923,7 @@ static int proxy_http_handler(request_rec *r, proxy_worker *worker,
const char *u;
proxy_http_req_t *req = NULL;
proxy_conn_rec *backend = NULL;
+ apr_bucket_brigade *input_brigade = NULL;
int is_ssl = 0;
conn_rec *c = r->connection;
proxy_dir_conf *dconf;
@@ -2005,8 +1989,20 @@ static int proxy_http_handler(request_rec *r, proxy_worker *worker,
dconf = ap_get_module_config(r->per_dir_config, &proxy_module);
+ /* We possibly reuse input data prefetched in previous call(s), e.g. for a
+ * balancer fallback scenario, and in this case the 100 continue settings
+ * should be consistent between balancer members. If not, we need to ignore
+ * Proxy100Continue on=>off once we tried to prefetch already, otherwise
+ * the HTTP_IN filter won't send 100 Continue for us anymore, and we might
+ * deadlock with the client waiting for each other. Note that off=>on is
+ * not an issue because in this case r->expecting_100 is false (the 100
+ * Continue is out already), but we make sure that prefetch will be
+ * nonblocking to avoid passing more time there.
+ */
+ apr_pool_userdata_get((void **)&input_brigade, "proxy-req-input", p);
+
/* Should we handle end-to-end or ping 100-continue? */
- if ((r->expecting_100 && dconf->forward_100_continue)
+ if ((r->expecting_100 && (dconf->forward_100_continue || input_brigade))
|| PROXY_DO_100_CONTINUE(worker, r)) {
/* We need to reset r->expecting_100 or prefetching will cause
* ap_http_filter() to send "100 Continue" response by itself. So
@@ -2023,7 +2019,8 @@ static int proxy_http_handler(request_rec *r, proxy_worker *worker,
/* Should we block while prefetching the body or try nonblocking and flush
* data to the backend ASAP?
*/
- else if (apr_table_get(r->subprocess_env, "proxy-prefetch-nonblocking")) {
+ else if (input_brigade || apr_table_get(r->subprocess_env,
+ "proxy-prefetch-nonblocking")) {
req->prefetch_nonblocking = 1;
}
@@ -2048,6 +2045,17 @@ static int proxy_http_handler(request_rec *r, proxy_worker *worker,
sizeof(req->server_portstr))))
goto cleanup;
+ /* The header is always (re-)built since it depends on worker settings,
+ * but the body can be fetched only once (even partially), so it's saved
+ * in between proxy_http_handler() calls should we come back here.
+ */
+ req->header_brigade = apr_brigade_create(p, req->bucket_alloc);
+ if (input_brigade == NULL) {
+ input_brigade = apr_brigade_create(p, req->bucket_alloc);
+ apr_pool_userdata_setn(input_brigade, "proxy-req-input", NULL, p);
+ }
+ req->input_brigade = input_brigade;
+
/* Prefetch (nonlocking) the request body so to increase the chance to get
* the whole (or enough) body and determine Content-Length vs chunked or
* spooled. By doing this before connecting or reusing the backend, we want
@@ -2058,8 +2066,6 @@ static int proxy_http_handler(request_rec *r, proxy_worker *worker,
* to reduce to the minimum the unavoidable local is_socket_connected() vs
* remote keepalive race condition.
*/
- req->input_brigade = apr_brigade_create(p, req->bucket_alloc);
- req->header_brigade = apr_brigade_create(p, req->bucket_alloc);
if ((status = ap_proxy_http_prefetch(req, uri, locurl)) != OK)
goto cleanup;