m4/websockets.m4

   1 # Macro to check if websockets support was enabled. This macro also
   2 # takes care of detecting older versions of libwebsockets (lacking
   3 # pkg-config support, no per-context userdata) and propagating this
   4 # information to config.h and the compilation process.
   5 #
   6
   7 AC_DEFUN([CHECK_WEBSOCKETS],
   8 [
   9 AC_LANG_PUSH([C])
  10 AC_ARG_ENABLE(websockets,
  11               [  --enable-websockets     enable websockets support],
  12               [enable_websockets=$enableval], [enable_websockets=auto])
  13
  14 # Check if we have properly packaged libwebsockets (json-c is now mandatory
  15 # and already has been tested for).
  16 if test "$enable_websockets" != "no"; then
  17     PKG_CHECK_MODULES(WEBSOCKETS, [libwebsockets],
  18                       [have_websockets=yes], [have_websockets=no])
  19     if test "$have_websockets" = "yes"; then
  20         WEBSOCKETS_CFLAGS="`pkg-config --cflags libwebsockets`"
  21         # Check for a couple of recent features we need to adopt to.
  22         saved_CFLAGS="$CFLAGS"
  23         saved_LDFLAGS="$LDFLAGS"
  24         saved_LIBS="$LIBS"
  25         # Note that (at least with autoconf 2.69 and gcc 4.7.2), setting
  26         # LD_AS_NEEDED to 1 breaks AC_LINK_IFELSE. That macro generates
  27         # the compilation command so that the libraries are specified
  28         # before the generated C source so all referenced/tested symbols
  29         # from any of the libraries end up being undefined. This fools
  30         # AC_LINK_IFELSE to consider the test a failure and select the
  31         # else branch.
  32         # rpmbuild always sets LD_AS_NEEDED to 1. To work around this save
  33         # and restore LD_AS_NEEDED for the duration of the AC_LINK_IFELSE
  34         # tests.
  35         saved_LD_AS_NEEDED="$LD_AS_NEEDED"
  36         unset LD_AS_NEEDED
  37         CFLAGS="`pkg-config --cflags libwebsockets`"
  38         LIBS="`pkg-config --libs libwebsockets`"
  39
  40         # Check for new context creation API.
  41         AC_MSG_CHECKING([for WEBSOCKETS new context creation API])
  42         AC_LINK_IFELSE(
  43            [AC_LANG_PROGRAM(
  44                  [[#include <stdlib.h>
  45                    #include <libwebsockets.h>]],
  46                  [[struct libwebsocket_context *ctx;
  47                    ctx = libwebsocket_create_context(NULL);]])],
  48             [websockets_cci=yes],
  49             [websockets_cci=no])
  50         AC_MSG_RESULT([$websockets_cci])
  51
  52         # Check for new libwebsockets_get_internal_extensions.
  53         AC_MSG_CHECKING([for WEBSOCKETS internal extension query API])
  54         AC_LINK_IFELSE(
  55            [AC_LANG_PROGRAM(
  56                  [[#include <stdlib.h>
  57                    #include <libwebsockets.h>]],
  58                  [[struct libwebsocket_extension *ext;
  59                    ext = libwebsocket_get_internal_extensions();]])],
  60             [websockets_query_ext=yes],
  61             [websockets_query_ext=no])
  62         AC_MSG_RESULT([$websockets_query_ext])
  63
  64         # Check for newer lws_set_log_level API.
  65         # Note that we cheat heavily here: instead of rolling a proper
  66         # test, we blindly assume gcc, turn on the -Werror flag (to catch
  67         # calls with a mismatching function pointer) and hope that we will
  68         # not get false negatives because of other warnings.
  69         no_werror_CFLAGS="$CFLAGS"
  70         CFLAGS="$CFLAGS -Werror"
  71         AC_MSG_CHECKING([for WEBSOCKETS updated logging API.])
  72         AC_LINK_IFELSE(
  73            [AC_LANG_PROGRAM(
  74                  [[#include <stdlib.h>
  75                    #include <libwebsockets.h>
  76                    static void logger(int level, const char *line) {
  77                        return;
  78                    }]],
  79                  [[lws_set_log_level(LLL_INFO, logger);]])],
  80             [websockets_log_with_level=yes],
  81             [websockets_log_with_level=no])
  82         AC_MSG_RESULT([$websockets_log_with_level])
  83
  84         # Check whether we have libwebsocket_close_and_free_session.
  85         AC_MSG_CHECKING([for WEBSOCKETS close_and_free_session API])
  86         AC_LINK_IFELSE(
  87            [AC_LANG_PROGRAM(
  88                  [[#include <stdlib.h>
  89                    #include <libwebsockets.h>]],
  90                  [[libwebsocket_close_and_free_session(NULL, NULL, 0);]])],
  91             [websockets_close_session=yes],
  92             [websockets_close_session=no])
  93         AC_MSG_RESULT([$websockets_close_session])
  94
  95         # Check for LWS_CALLBACK_FILTER_HTTP_CONNECTION.
  96         AC_MSG_CHECKING([for WEBSOCKETS LWS_CALLBACK_FILTER_HTTP_CONNECTION])
  97         AC_LINK_IFELSE(
  98            [AC_LANG_PROGRAM(
  99                  [[#include <stdlib.h>
 100                    #include <libwebsockets.h>]],
 101                  [[int foo = LWS_CALLBACK_FILTER_HTTP_CONNECTION;]])],
 102             [websockets_filter_http_connection=yes],
 103             [websockets_filter_http_connection=no])
 104         AC_MSG_RESULT([$websockets_filter_http_connection])
 105
 106         # Check for LWS_CALLBACK_CHANGE_MODE_POLL_FD.
 107         AC_MSG_CHECKING([for WEBSOCKETS LWS_CALLBACK_CHANGE_MODE_POLL_FD])
 108         AC_LINK_IFELSE(
 109            [AC_LANG_PROGRAM(
 110                  [[#include <stdlib.h>
 111                    #include <libwebsockets.h>]],
 112                  [[int foo = LWS_CALLBACK_CHANGE_MODE_POLL_FD;]])],
 113             [websockets_change_poll=yes],
 114             [websockets_change_poll=no])
 115         AC_MSG_RESULT([$websockets_change_poll])
 116
 117         # Check the signature of libwebsockets_serve_http_file to see if
 118         # it takes an extra (other_headers) argument.
 119         AC_MSG_CHECKING([for WEBSOCKETS libwebsockets_serve_http_file other_headers argument])
 120         AC_LINK_IFELSE(
 121            [AC_LANG_PROGRAM(
 122                  [[#include <stdlib.h>
 123                    #include <libwebsockets.h>]],
 124                  [[return libwebsockets_serve_http_file(NULL, NULL, "", "", "");]])],
 125             [websockets_serve_file_extraarg=yes],
 126             [websockets_serve_file_extraarg=no])
 127         AC_MSG_RESULT([$websockets_serve_file_extraarg])
 128
 129         CFLAGS="$saved_CFLAGS"
 130         LDFLAGS="$saved_LDFLAGS"
 131         LIBS="$saved_LIBS"
 132         if test -n "$saved_LD_AS_NEEDED"; then
 133             export LD_AS_NEEDED="$saved_LD_AS_NEEDED"
 134         fi
 135     else
 136         WEBSOCKETS_CFLAGS=""
 137     fi
 138
 139     # Check for older websockets.
 140     if test "$have_websockets" = "no"; then
 141         saved_LDFLAGS="$LDFLAGS"
 142         saved_LIBS="$LIBS"
 143         LIBS="-lwebsockets"
 144         AC_MSG_CHECKING([for WEBSOCKETS without pkg-config support])
 145         AC_LINK_IFELSE(
 146            [AC_LANG_PROGRAM(
 147                  [[#include <stdlib.h>
 148                    #include <libwebsockets.h>]],
 149                  [[struct libwebsocket_context *ctx;
 150                    ctx = libwebsocket_create_context(0, NULL, NULL, NULL,
 151                                                      NULL, NULL, NULL,
 152                                                      -1, -1, 0, NULL);]])],
 153             [have_websockets=yes;old_websockets=no],
 154             [have_websockets=no])
 155         AC_MSG_RESULT([$have_websockets])
 156     fi
 157
 158     # Check if we have a really old libwebsockets, still without
 159     # per-context user data.
 160     if test "$old_websockets" != "no"; then
 161         AC_MSG_CHECKING([for really old WEBSOCKETS])
 162         AC_LINK_IFELSE(
 163             [AC_LANG_PROGRAM(
 164                  [[#include <stdlib.h>
 165                    #include <libwebsockets.h>]],
 166                  [[struct libwebsocket_context *ctx;
 167                    ctx = libwebsocket_create_context(0, NULL, NULL, NULL,
 168                                                      NULL, NULL,
 169                                                      -1, -1, 0);]])],
 170             [have_websockets=yes;old_websockets=yes],
 171             [old_websockets=no])
 172         AC_MSG_RESULT([$old_websockets])
 173     fi
 174
 175     WEBSOCKETS_LIBS="-lwebsockets"
 176     if test "$old_websockets" = "yes"; then
 177         WEBSOCKETS_CFLAGS="$WEBSOCKETS_CFLAGS -DWEBSOCKETS_OLD"
 178     fi
 179     if test "$websockets_cci" = "yes"; then
 180         WEBSOCKETS_CFLAGS="$WEBSOCKETS_CFLAGS -DWEBSOCKETS_CONTEXT_INFO"
 181     fi
 182     if test "$websockets_query_ext" = "yes"; then
 183         WEBSOCKETS_CFLAGS="$WEBSOCKETS_CFLAGS -DWEBSOCKETS_QUERY_EXTENSIONS"
 184     fi
 185     if test "$websockets_log_with_level" = "yes"; then
 186         WEBSOCKETS_CFLAGS="$WEBSOCKETS_CFLAGS -DWEBSOCKETS_LOG_WITH_LEVEL"
 187     fi
 188     if test "$websockets_close_session" = "yes"; then
 189         WEBSOCKETS_CFLAGS="$WEBSOCKETS_CFLAGS -DWEBSOCKETS_CLOSE_SESSION"
 190     fi
 191     if test "$websockets_filter_http_connection" = "yes"; then
 192         WEBSOCKETS_CFLAGS="$WEBSOCKETS_CFLAGS -DWEBSOCKETS_FILTER_HTTP_CONNECTION"
 193     fi
 194     if test "$websockets_change_poll" = "yes"; then
 195         WEBSOCKETS_CFLAGS="$WEBSOCKETS_CFLAGS -DWEBSOCKETS_CHANGE_MODE_POLL_FD"
 196     fi
 197     if test "$websockets_serve_file_extraarg" = "yes"; then
 198         WEBSOCKETS_CFLAGS="$WEBSOCKETS_CFLAGS -DWEBSOCKETS_SERVE_FILE_EXTRAARG"
 199     fi
 200
 201     LDFLAGS="$saved_LDFLAGS"
 202     LIBS="$saved_LIBS"
 203 else
 204     AC_MSG_NOTICE([libwebsockets support is disabled.])
 205 fi
 206
 207 # Bail out if we lack mandatory support.
 208 if test "$enable_websockets" = "yes" -a "$have_websockets" = "no"; then
 209     AC_MSG_ERROR([libwebsockets development libraries not found.])
 210 fi
 211
 212 # Enable if found and autosupport requested.
 213 if test "$enable_websockets" = "auto"; then
 214     enable_websockets=$have_websockets
 215 fi
 216
 217 # If enabled, set up our autoconf variables accordingly.
 218 if test "$enable_websockets" = "yes"; then
 219     AC_DEFINE([WEBSOCKETS_ENABLED], 1, [Enable websockets support ?])
 220     if test "$old_websockets" = "yes"; then
 221         AC_DEFINE([WEBSOCKETS_OLD], 1, [No per-context userdata ?])
 222     fi
 223 fi
 224
 225 # Finally substitute everything.
 226 AM_CONDITIONAL(WEBSOCKETS_ENABLED, [test "$enable_websockets" = "yes"])
 227 AM_CONDITIONAL(WEBSOCKETS_OLD, [test "$old_websockets" = "yes"])
 228 AC_SUBST(WEBSOCKETS_ENABLED)
 229 AC_SUBST(WEBSOCKETS_CFLAGS)
 230 AC_SUBST(WEBSOCKETS_LIBS)
 231 AC_SUBST(WEBSOCKETS_OLD)
 232
 233 AC_LANG_POP
 234 ])