Stream: UDP proxy.

auto/options

@@ -479,8 +479,8 @@ cat << END
   --without-mail_imap_module         disable ngx_mail_imap_module
   --without-mail_smtp_module         disable ngx_mail_smtp_module
 
-  --with-stream                      enable TCP proxy module
-  --with-stream=dynamic              enable dynamic TCP proxy module
+  --with-stream                      enable TCP/UDP proxy module
+  --with-stream=dynamic              enable dynamic TCP/UDP proxy module
   --with-stream_ssl_module           enable ngx_stream_ssl_module
   --without-stream_limit_conn_module disable ngx_stream_limit_conn_module
   --without-stream_access_module     disable ngx_stream_access_module

auto/sources

@@ -165,6 +165,7 @@ UNIX_SRCS="$CORE_SRCS $EVENT_SRCS \
             src/os/unix/ngx_udp_recv.c \
             src/os/unix/ngx_send.c \
             src/os/unix/ngx_writev_chain.c \
+            src/os/unix/ngx_udp_send.c \
             src/os/unix/ngx_channel.c \
             src/os/unix/ngx_shmem.c \
             src/os/unix/ngx_process.c \

auto/unix

@@ -329,6 +329,45 @@ ngx_feature_test="setsockopt(0, SOL_SOCKET, SO_ACCEPTFILTER, NULL, 0)"
 . auto/feature
 
 
+# BSD way to get IPv4 datagram destination address
+
+ngx_feature="IP_RECVDSTADDR"
+ngx_feature_name="NGX_HAVE_IP_RECVDSTADDR"
+ngx_feature_run=no
+ngx_feature_incs="#include <sys/socket.h>
+                  #include <netinet/in.h>"
+ngx_feature_path=
+ngx_feature_libs=
+ngx_feature_test="setsockopt(0, IPPROTO_IP, IP_RECVDSTADDR, NULL, 0)"
+. auto/feature
+
+
+# Linux way to get IPv4 datagram destination address
+
+ngx_feature="IP_PKTINFO"
+ngx_feature_name="NGX_HAVE_IP_PKTINFO"
+ngx_feature_run=no
+ngx_feature_incs="#include <sys/socket.h>
+                  #include <netinet/in.h>"
+ngx_feature_path=
+ngx_feature_libs=
+ngx_feature_test="setsockopt(0, IPPROTO_IP, IP_PKTINFO, NULL, 0)"
+. auto/feature
+
+
+# RFC 3542 way to get IPv6 datagram destination address
+
+ngx_feature="IPV6_RECVPKTINFO"
+ngx_feature_name="NGX_HAVE_IPV6_RECVPKTINFO"
+ngx_feature_run=no
+ngx_feature_incs="#include <sys/socket.h>
+                  #include <netinet/in.h>"
+ngx_feature_path=
+ngx_feature_libs=
+ngx_feature_test="setsockopt(0, IPPROTO_IPV6, IPV6_RECVPKTINFO, NULL, 0)"
+. auto/feature
+
+
 ngx_feature="TCP_DEFER_ACCEPT"
 ngx_feature_name="NGX_HAVE_DEFERRED_ACCEPT"
 ngx_feature_run=no

src/core/ngx_connection.c

@@ -566,6 +566,11 @@ ngx_open_listening_sockets(ngx_cycle_t *cycle)
             }
 #endif
 
+            if (ls[i].type != SOCK_STREAM) {
+                ls[i].fd = s;
+                continue;
+            }
+
             if (listen(s, ls[i].backlog) == -1) {
                 err = ngx_socket_errno;
 
@@ -865,6 +870,67 @@ ngx_configure_listening_sockets(ngx_cycle_t *cycle)
 #endif
 
 #endif /* NGX_HAVE_DEFERRED_ACCEPT */
+
+#if (NGX_HAVE_IP_RECVDSTADDR)
+
+        if (ls[i].wildcard
+            && ls[i].type == SOCK_DGRAM
+            && ls[i].sockaddr->sa_family == AF_INET)
+        {
+            value = 1;
+
+            if (setsockopt(ls[i].fd, IPPROTO_IP, IP_RECVDSTADDR,
+                           (const void *) &value, sizeof(int))
+                == -1)
+            {
+                ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
+                              "setsockopt(IP_RECVDSTADDR) "
+                              "for %V failed, ignored",
+                              &ls[i].addr_text);
+            }
+        }
+
+#elif (NGX_HAVE_IP_PKTINFO)
+
+        if (ls[i].wildcard
+            && ls[i].type == SOCK_DGRAM
+            && ls[i].sockaddr->sa_family == AF_INET)
+        {
+            value = 1;
+
+            if (setsockopt(ls[i].fd, IPPROTO_IP, IP_PKTINFO,
+                           (const void *) &value, sizeof(int))
+                == -1)
+            {
+                ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
+                              "setsockopt(IP_PKTINFO) "
+                              "for %V failed, ignored",
+                              &ls[i].addr_text);
+            }
+        }
+
+#endif
+
+#if (NGX_HAVE_INET6 && NGX_HAVE_IPV6_RECVPKTINFO)
+
+        if (ls[i].wildcard
+            && ls[i].type == SOCK_DGRAM
+            && ls[i].sockaddr->sa_family == AF_INET6)
+        {
+            value = 1;
+
+            if (setsockopt(ls[i].fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
+                           (const void *) &value, sizeof(int))
+                == -1)
+            {
+                ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_socket_errno,
+                              "setsockopt(IPV6_RECVPKTINFO) "
+                              "for %V failed, ignored",
+                              &ls[i].addr_text);
+            }
+        }
+
+#endif
     }
 
     return;
@@ -978,7 +1044,7 @@ ngx_get_connection(ngx_socket_t s, ngx_log_t *log)
     ngx_cycle->free_connections = c->data;
     ngx_cycle->free_connection_n--;
 
-    if (ngx_cycle->files) {
+    if (ngx_cycle->files && ngx_cycle->files[s] == NULL) {
         ngx_cycle->files[s] = c;
     }
 
@@ -1019,7 +1085,7 @@ ngx_free_connection(ngx_connection_t *c)
     ngx_cycle->free_connections = c;
     ngx_cycle->free_connection_n++;
 
-    if (ngx_cycle->files) {
+    if (ngx_cycle->files && ngx_cycle->files[c->fd] == c) {
         ngx_cycle->files[c->fd] = NULL;
     }
 }
@@ -1045,16 +1111,18 @@ ngx_close_connection(ngx_connection_t *c)
         ngx_del_timer(c->write);
     }
 
-    if (ngx_del_conn) {
-        ngx_del_conn(c, NGX_CLOSE_EVENT);
+    if (!c->shared) {
+        if (ngx_del_conn) {
+            ngx_del_conn(c, NGX_CLOSE_EVENT);
 
-    } else {
-        if (c->read->active || c->read->disabled) {
-            ngx_del_event(c->read, NGX_READ_EVENT, NGX_CLOSE_EVENT);
-        }
+        } else {
+            if (c->read->active || c->read->disabled) {
+                ngx_del_event(c->read, NGX_READ_EVENT, NGX_CLOSE_EVENT);
+            }
 
-        if (c->write->active || c->write->disabled) {
-            ngx_del_event(c->write, NGX_WRITE_EVENT, NGX_CLOSE_EVENT);
+            if (c->write->active || c->write->disabled) {
+                ngx_del_event(c->write, NGX_WRITE_EVENT, NGX_CLOSE_EVENT);
+            }
         }
     }
 
@@ -1078,6 +1146,10 @@ ngx_close_connection(ngx_connection_t *c)
     fd = c->fd;
     c->fd = (ngx_socket_t) -1;
 
+    if (c->shared) {
+        return;
+    }
+
     if (ngx_close_socket(fd) == -1) {
 
         err = ngx_socket_errno;

src/core/ngx_connection.h

@@ -64,6 +64,7 @@ struct ngx_listening_s {
     unsigned            nonblocking:1;
     unsigned            shared:1;    /* shared between threads or processes */
     unsigned            addr_ntop:1;
+    unsigned            wildcard:1;
 
 #if (NGX_HAVE_INET6 && defined IPV6_V6ONLY)
     unsigned            ipv6only:1;
@@ -141,6 +142,8 @@ struct ngx_connection_s {
 
     ngx_pool_t         *pool;
 
+    int                 type;
+
     struct sockaddr    *sockaddr;
     socklen_t           socklen;
     ngx_str_t           addr_text;
@@ -174,6 +177,7 @@ struct ngx_connection_s {
     unsigned            idle:1;
     unsigned            reusable:1;
     unsigned            close:1;
+    unsigned            shared:1;
 
     unsigned            sendfile:1;
     unsigned            sndlowat:1;

src/event/ngx_event.c

@@ -746,6 +746,7 @@ ngx_event_process_init(ngx_cycle_t *cycle)
             return NGX_ERROR;
         }
 
+        c->type = ls[i].type;
         c->log = &ls[i].log;
 
         c->listening = &ls[i];
@@ -818,7 +819,8 @@ ngx_event_process_init(ngx_cycle_t *cycle)
 
 #else
 
-        rev->handler = ngx_event_accept;
+        rev->handler = (c->type == SOCK_STREAM) ? ngx_event_accept
+                                                : ngx_event_recvmsg;
 
         if (ngx_use_accept_mutex
 #if (NGX_HAVE_REUSEPORT)

src/event/ngx_event.h

@@ -418,6 +418,7 @@ extern ngx_os_io_t  ngx_io;
 #define ngx_udp_recv         ngx_io.udp_recv
 #define ngx_send             ngx_io.send
 #define ngx_send_chain       ngx_io.send_chain
+#define ngx_udp_send         ngx_io.udp_send
 
 
 #define NGX_EVENT_MODULE      0x544E5645  /* "EVNT" */
@@ -491,6 +492,9 @@ extern ngx_module_t           ngx_event_core_module;
 
 
 void ngx_event_accept(ngx_event_t *ev);
+#if !(NGX_WIN32)
+void ngx_event_recvmsg(ngx_event_t *ev);
+#endif
 ngx_int_t ngx_trylock_accept_mutex(ngx_cycle_t *cycle);
 u_char *ngx_accept_log_error(ngx_log_t *log, u_char *buf, size_t len);