[nginx] Stream: proxy_requests directive.

[Vladimir Homutov]

details: http://hg.nginx.org/nginx/rev/4698cede59ff
branches:
changeset: 7393:4698cede59ff
user: Vladimir Homutov <***@nginx.com>
date: Mon Nov 12 16:29:30 2018 +0300
description:
Stream: proxy_requests directive.

The directive allows to drop binding between a client and existing UDP stream
session after receiving a specified number of packets. First packet from the
same client address and port will start a new session. Old session continues
to exist and will terminate at moment defined by configuration: either after
receiving the expected number of responses, or after timeout, as specified by
the "proxy_responses" and/or "proxy_timeout" directives.

By default, proxy_requests is zero (disabled).

diffstat:

src/event/ngx_event.h | 1 +
src/event/ngx_event_udp.c | 15 +++++++++++++--
src/stream/ngx_stream_proxy_module.c | 27 +++++++++++++++++++++++++--
3 files changed, 39 insertions(+), 4 deletions(-)

diffs (127 lines):

diff -r 04ff25798002 -r 4698cede59ff src/event/ngx_event.h
--- a/src/event/ngx_event.h Mon Nov 12 12:05:03 2018 +0300
+++ b/src/event/ngx_event.h Mon Nov 12 16:29:30 2018 +0300
@@ -509,6 +509,7 @@ void ngx_event_recvmsg(ngx_event_t *ev);
void ngx_udp_rbtree_insert_value(ngx_rbtree_node_t *temp,
ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel);
#endif
+void ngx_delete_udp_connection(void *data);
ngx_int_t ngx_trylock_accept_mutex(ngx_cycle_t *cycle);
ngx_int_t ngx_enable_accept_events(ngx_cycle_t *cycle);
u_char *ngx_accept_log_error(ngx_log_t *log, u_char *buf, size_t len);
diff -r 04ff25798002 -r 4698cede59ff src/event/ngx_event_udp.c
--- a/src/event/ngx_event_udp.c Mon Nov 12 12:05:03 2018 +0300
+++ b/src/event/ngx_event_udp.c Mon Nov 12 16:29:30 2018 +0300
@@ -23,7 +23,6 @@ static void ngx_close_accepted_udp_conne
static ssize_t ngx_udp_shared_recv(ngx_connection_t *c, u_char *buf,
size_t size);
static ngx_int_t ngx_insert_udp_connection(ngx_connection_t *c);
-static void ngx_delete_udp_connection(void *data);
static ngx_connection_t *ngx_lookup_udp_connection(ngx_listening_t *ls,
struct sockaddr *sockaddr, socklen_t socklen,
struct sockaddr *local_sockaddr, socklen_t local_socklen);
@@ -558,11 +557,15 @@ ngx_insert_udp_connection(ngx_connection
}


-static void
+void
ngx_delete_udp_connection(void *data)
{
ngx_connection_t *c = data;

+ if (c->udp == NULL) {
+ return;
+ }
+
ngx_rbtree_delete(&c->listening->rbtree, &c->udp->node);

c->udp = NULL;
@@ -643,4 +646,12 @@ ngx_lookup_udp_connection(ngx_listening_
return NULL;
}

+#else
+
+void
+ngx_delete_udp_connection(void *data)
+{
+ return;
+}
+
#endif
diff -r 04ff25798002 -r 4698cede59ff src/stream/ngx_stream_proxy_module.c
--- a/src/stream/ngx_stream_proxy_module.c Mon Nov 12 12:05:03 2018 +0300
+++ b/src/stream/ngx_stream_proxy_module.c Mon Nov 12 16:29:30 2018 +0300
@@ -26,6 +26,7 @@ typedef struct {
size_t buffer_size;
size_t upload_rate;
size_t download_rate;
+ ngx_uint_t requests;
ngx_uint_t responses;
ngx_uint_t next_upstream_tries;
ngx_flag_t next_upstream;
@@ -195,6 +196,13 @@ static ngx_command_t ngx_stream_proxy_c
offsetof(ngx_stream_proxy_srv_conf_t, download_rate),
NULL },

+ { ngx_string("proxy_requests"),
+ NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
+ ngx_conf_set_num_slot,
+ NGX_STREAM_SRV_CONF_OFFSET,
+ offsetof(ngx_stream_proxy_srv_conf_t, requests),
+ NULL },
+
{ ngx_string("proxy_responses"),
NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
ngx_conf_set_num_slot,
@@ -1341,11 +1349,14 @@ ngx_stream_proxy_process_connection(ngx_

} else {
if (s->connection->type == SOCK_DGRAM) {
- if (pscf->responses == NGX_MAX_INT32_VALUE) {
+
+ if (pscf->responses == NGX_MAX_INT32_VALUE
+ || (u->responses >= pscf->responses * u->requests))
+ {

/*
* successfully terminate timed out UDP session
- * with unspecified number of responses
+ * if expected number of responses was received
*/

handler = c->log->handler;
@@ -1692,6 +1703,14 @@ ngx_stream_proxy_test_finalize(ngx_strea

if (c->type == SOCK_DGRAM) {

+ if (pscf->requests && u->requests < pscf->requests) {
+ return NGX_DECLINED;
+ }
+
+ if (pscf->requests) {
+ ngx_delete_udp_connection(c);
+ }
+
if (pscf->responses == NGX_MAX_INT32_VALUE
|| u->responses < pscf->responses * u->requests)
{
@@ -1943,6 +1962,7 @@ ngx_stream_proxy_create_srv_conf(ngx_con
conf->buffer_size = NGX_CONF_UNSET_SIZE;
conf->upload_rate = NGX_CONF_UNSET_SIZE;
conf->download_rate = NGX_CONF_UNSET_SIZE;
+ conf->requests = NGX_CONF_UNSET_UINT;
conf->responses = NGX_CONF_UNSET_UINT;
conf->next_upstream_tries = NGX_CONF_UNSET_UINT;
conf->next_upstream = NGX_CONF_UNSET;
@@ -1987,6 +2007,9 @@ ngx_stream_proxy_merge_srv_conf(ngx_conf
ngx_conf_merge_size_value(conf->download_rate,
prev->download_rate, 0);

+ ngx_conf_merge_uint_value(conf->requests,
+ prev->requests, 0);
+
ngx_conf_merge_uint_value(conf->responses,
prev->responses, NGX_MAX_INT32_VALUE);