Upstream: the "transparent" parameter of proxy_bind and friends.

This parameter lets binding the proxy connection to a non-local address.
Upstream will see the connection as coming from that address.
When used with $remote_addr, upstream will accept the connection from real
client address.

Example:

    proxy_bind $remote_addr transparent;

1 files changed, 38 insertions, 0 deletions

diff --git a/auto/unix b/auto/unix
index 8c0e8135c..e6396ef2a 100755
--- a/auto/unix
+++ b/auto/unix
@@ -329,6 +329,44 @@ ngx_feature_test="setsockopt(0, SOL_SOCKET, SO_ACCEPTFILTER, NULL, 0)"
 . auto/feature
 
 
+# NetBSD bind to any address for transparent proxying
+
+ngx_feature="SO_BINDANY"
+ngx_feature_name="NGX_HAVE_TRANSPARENT_PROXY"
+ngx_feature_run=no
+ngx_feature_incs="#include <sys/socket.h>"
+ngx_feature_path=
+ngx_feature_libs=
+ngx_feature_test="setsockopt(0, SOL_SOCKET, SO_BINDANY, NULL, 0)"
+. auto/feature
+
+
+# Linux transparent proxying
+
+ngx_feature="IP_TRANSPARENT"
+ngx_feature_name="NGX_HAVE_TRANSPARENT_PROXY"
+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_TRANSPARENT, NULL, 0)"
+. auto/feature
+
+
+# FreeBSD bind to any address for transparent proxying
+
+ngx_feature="IP_BINDANY"
+ngx_feature_name="NGX_HAVE_TRANSPARENT_PROXY"
+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_BINDANY, NULL, 0)"
+. auto/feature
+
+
 # BSD way to get IPv4 datagram destination address
 
 ngx_feature="IP_RECVDSTADDR"