backport mod_deflate to lighttpd 1.4 (fixes #1824, fixes #2753)

lots of fixes and improvements

limitations: see comments at top of mod_deflate.c

missing functionality: encode streaming response
  (module currently requires response be collected before being sent)

potential functionality: addition of compressed file cache would
  allow mod_deflate to fully supplant mod_compress in lighttpd 1.4.x

x-ref:
  "Adding mod_deflate to 1.4.xx"
  https://redmine.lighttpd.net/issues/1824
  "mod_deflate backport compile error if ENABLE_MMAP not defined"
  https://redmine.lighttpd.net/issues/2753

github: closes #67

configure.ac

@@ -871,7 +871,7 @@ AC_OUTPUT
 
 
 do_build="mod_cgi mod_fastcgi mod_extforward mod_proxy mod_evhost mod_simple_vhost mod_access mod_alias mod_setenv mod_usertrack mod_auth mod_status mod_accesslog"
-do_build="$do_build mod_rrdtool mod_secdownload mod_expire mod_compress mod_dirlisting mod_indexfile mod_userdir mod_webdav mod_staticfile mod_scgi mod_flv_streaming mod_ssi"
+do_build="$do_build mod_rrdtool mod_secdownload mod_expire mod_compress mod_dirlisting mod_indexfile mod_userdir mod_webdav mod_staticfile mod_scgi mod_flv_streaming mod_ssi mod_deflate"
 
 plugins="mod_rewrite mod_redirect mod_trigger_b4_dl"
 features="regex-conditionals"

src/CMakeLists.txt

@@ -567,6 +567,7 @@ if(NOT WIN32)
 endif()
 add_and_install_library(mod_cml "mod_cml.c;mod_cml_lua.c;mod_cml_funcs.c")
 add_and_install_library(mod_compress mod_compress.c)
+add_and_install_library(mod_deflate mod_deflate.c)
 add_and_install_library(mod_dirlisting mod_dirlisting.c)
 add_and_install_library(mod_evasive mod_evasive.c)
 add_and_install_library(mod_evhost mod_evhost.c)
@@ -683,8 +684,10 @@ target_link_libraries(mod_authn_ldap ${L_MOD_AUTHN_LDAP})
 if(HAVE_ZLIB_H)
 	if(HAVE_BZLIB_H)
 		target_link_libraries(mod_compress ${ZLIB_LIBRARY} bz2)
+		target_link_libraries(mod_deflate ${ZLIB_LIBRARY} bz2)
 	else()
 		target_link_libraries(mod_compress ${ZLIB_LIBRARY})
+		target_link_libraries(mod_deflate ${ZLIB_LIBRARY})
 	endif()
 endif()
 

src/Makefile.am

@@ -257,6 +257,11 @@ mod_compress_la_SOURCES = mod_compress.c
 mod_compress_la_LDFLAGS = $(common_module_ldflags)
 mod_compress_la_LIBADD = $(Z_LIB) $(BZ_LIB) $(common_libadd)
 
+lib_LTLIBRARIES += mod_deflate.la
+mod_deflate_la_SOURCES = mod_deflate.c
+mod_deflate_la_LDFLAGS = $(common_module_ldflags)
+mod_deflate_la_LIBADD = $(Z_LIB) $(BZ_LIB) $(common_libadd)
+
 lib_LTLIBRARIES += mod_auth.la
 mod_auth_la_SOURCES = mod_auth.c
 mod_auth_la_LDFLAGS = $(common_module_ldflags)
@@ -338,6 +343,7 @@ lighttpd_SOURCES = \
   mod_cgi.c \
   mod_cml.c mod_cml_lua.c mod_cml_funcs.c \
   mod_compress.c \
+  mod_deflate.c \
   mod_dirlisting.c \
   mod_evasive.c \
   mod_expire.c \

src/SConscript

@@ -98,6 +98,7 @@ modules = {
 	'mod_expire' : { 'src' : [ 'mod_expire.c' ] },
 	'mod_status' : { 'src' : [ 'mod_status.c' ] },
 	'mod_compress' : { 'src' : [ 'mod_compress.c' ], 'lib' : [ env['LIBZ'], env['LIBBZ2'] ] },
+	'mod_deflate' : { 'src' : [ 'mod_deflate.c' ], 'lib' : [ env['LIBZ'], env['LIBBZ2'] ] },
 	'mod_redirect' : { 'src' : [ 'mod_redirect.c' ], 'lib' : [ env['LIBPCRE'] ] },
 	'mod_rewrite' : { 'src' : [ 'mod_rewrite.c' ], 'lib' : [ env['LIBPCRE'] ] },
 	'mod_auth' : { 'src' : [ 'mod_auth.c' ] },

src/connections.c

@@ -441,6 +441,16 @@ static int connection_handle_write_prepare(server *srv, connection *con) {
 		break;
 	}
 
+	/* Allow filter plugins to change response headers before they are written. */
+	switch(plugins_call_handle_response_start(srv, con)) {
+	case HANDLER_GO_ON:
+	case HANDLER_FINISHED:
+		break;
+	default:
+		log_error_write(srv, __FILE__, __LINE__, "s", "response_start plugin failed");
+		return -1;
+	}
+
 	if (con->file_finished) {
 		/* we have all the content and chunked encoding is not used, set a content-length */
 

src/plugin.c

@@ -40,6 +40,7 @@ typedef enum {
 	PLUGIN_FUNC_HANDLE_SIGHUP,
 	PLUGIN_FUNC_HANDLE_SUBREQUEST,
 	PLUGIN_FUNC_HANDLE_SUBREQUEST_START,
+	PLUGIN_FUNC_HANDLE_RESPONSE_START,
 	PLUGIN_FUNC_HANDLE_DOCROOT,
 	PLUGIN_FUNC_HANDLE_PHYSICAL,
 	PLUGIN_FUNC_CONNECTION_RESET,
@@ -332,6 +333,7 @@ PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_REQUEST_DONE, handle_request_done)
 PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_CONNECTION_CLOSE, handle_connection_close)
 PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_SUBREQUEST, handle_subrequest)
 PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_SUBREQUEST_START, handle_subrequest_start)
+PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_RESPONSE_START, handle_response_start)
 PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_DOCROOT, handle_docroot)
 PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_PHYSICAL, handle_physical)
 PLUGIN_TO_SLOT(PLUGIN_FUNC_CONNECTION_RESET, connection_reset)
@@ -462,6 +464,7 @@ handler_t plugins_call_init(server *srv) {
 		PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_SIGHUP, handle_sighup);
 		PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_SUBREQUEST, handle_subrequest);
 		PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_SUBREQUEST_START, handle_subrequest_start);
+		PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_RESPONSE_START, handle_response_start);
 		PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_DOCROOT, handle_docroot);
 		PLUGIN_TO_SLOT(PLUGIN_FUNC_HANDLE_PHYSICAL, handle_physical);
 		PLUGIN_TO_SLOT(PLUGIN_FUNC_CONNECTION_RESET, connection_reset);

src/plugin.h

@@ -53,6 +53,7 @@ typedef struct {
 											    * has to be found
 											    */
 	handler_t (* handle_subrequest)      (server *srv, connection *con, void *p_d);    /* */
+	handler_t (* handle_response_start)  (server *srv, connection *con, void *p_d);    /* before response headers are written */
 	handler_t (* connection_reset)       (server *srv, connection *con, void *p_d);    /* */
 	void *data;
 
@@ -67,6 +68,7 @@ handler_t plugins_call_handle_uri_raw(server *srv, connection *con);
 handler_t plugins_call_handle_uri_clean(server *srv, connection *con);
 handler_t plugins_call_handle_subrequest_start(server *srv, connection *con);
 handler_t plugins_call_handle_subrequest(server *srv, connection *con);
+handler_t plugins_call_handle_response_start(server *srv, connection *con);
 handler_t plugins_call_handle_request_done(server *srv, connection *con);
 handler_t plugins_call_handle_docroot(server *srv, connection *con);
 handler_t plugins_call_handle_physical(server *srv, connection *con);