From: des <des@d4fa192b-c00b-0410-8231-f00ffab90ce4>
Date: Wed, 23 Jan 2008 20:23:20 +0000 (+0000)
Subject: Improve readability, such as it is.
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f771aa1da6797e25966bfb9f14df79a5fd9a8031;p=varnish

Improve readability, such as it is.

Allow the user to disable specific acceptor mechanisms (e.g. do not
use epoll even though it is available).

Don't look for kqueue on systems where we know it doesn't work.

Bail if no acceptor mechanism was found.

Bail if no curses or ncurses was found.

Warn the user if SO_{RCV,SND}TIMEO are non-functional.


git-svn-id: svn+ssh://projects.linpro.no/svn/varnish/trunk@2382 d4fa192b-c00b-0410-8231-f00ffab90ce4
---

diff --git a/varnish-cache/configure.ac b/varnish-cache/configure.ac
index 3b503bc6..dde05bad 100644
--- a/varnish-cache/configure.ac
+++ b/varnish-cache/configure.ac
@@ -43,6 +43,11 @@ CURSES_LIBS="${LIBS}"
 LIBS="${save_LIBS}"
 AC_SUBST(CURSES_LIBS)
 
+# people tend to forget about curses until the build breaks
+if test "$ac_cv_search_initscr" = no; then
+	AC_MSG_ERROR([curses or ncurses is required])
+fi
+
 save_LIBS="${LIBS}"
 LIBS=""
 AC_SEARCH_LIBS(pthread_create, [thr pthread c_r])
@@ -125,12 +130,71 @@ LIBS="${LIBS} ${RT_LIBS}"
 AC_CHECK_FUNCS([clock_gettime])
 LIBS="${save_LIBS}"
 
-# Check which mechanism to use for the acceptor
-AC_CHECK_FUNCS([kqueue])
-AC_CHECK_FUNCS([epoll_ctl])
-AC_CHECK_FUNCS([poll])
+# Check which mechanism to use for the acceptor.  We look for kqueue
+# only on platforms on which we know that it works, because there are
+# platforms where a simple AC_CHECK_FUNCS([kqueue]) would succeed but
+# the build would fail.  We also allow the user to disable mechanisms
+# he doesn't want to use.
+
+# --enable-kqueue
+AC_ARG_ENABLE(kqueue,
+    AS_HELP_STRING([--enable-kqueue],
+	[use kqueue if available (default is YES)]),
+    ,
+    [enable_kqueue=yes])
+
+if test "$enable_kqueue" = yes; then
+	case $host in
+	*-*-freebsd*)
+		AC_CHECK_FUNCS([kqueue])
+		;;
+	*-*-bsd*)
+		# No other BSD has a sufficiently recent implementation
+		AC_MSG_WARN([won't look for kqueue() on $host])
+		ac_cv_func_kqueue=no
+		;;
+	esac
+else
+	ac_cv_func_kqueue=no
+fi
+
+# --enable-epoll
+AC_ARG_ENABLE(epoll,
+    AS_HELP_STRING([--enable-epoll],
+	[use epoll if available (default is YES)]),
+    ,
+    [enable_epoll=yes])
+
+if test "$enable_epoll" = yes; then
+	AC_CHECK_FUNCS([epoll_ctl])
+else
+	ac_cv_func_epoll_ctl=no
+fi
+
+# --enable-poll
+AC_ARG_ENABLE(poll,
+    AS_HELP_STRING([--enable-poll],
+	[use poll if available (default is YES)]),
+    ,
+    [enable_poll=yes])
+
+if test "$enable_poll" = yes; then
+	AC_CHECK_FUNCS([poll])
+else
+	ac_cv_func_poll=no
+fi
+
+if test "$ac_cv_func_kqueue" != yes &&
+   test "$ac_cv_func_epoll_ctl" != yes &&
+   test "$ac_cv_func_poll" != yes; then
+	AC_MSG_ERROR([no usable acceptor mechanism])
+fi
+
+# Solaris defines SO_{RCV,SND}TIMEO, but does not implement them.
+# Varnish will build and run without these, but connections will not
+# time out, which may leave Varnish vulnerable to denail-of-service
+# attacks which would not be possible on other platforms.
 
-# Solaris defines SO_{RCV,SND}TIMEO, but does not implement them
 AC_CACHE_CHECK([whether SO_RCVTIMEO works],
   [ac_cv_so_rcvtimeo_works],
   [AC_RUN_IFELSE(
@@ -169,6 +233,11 @@ if test "$ac_cv_so_sndtimeo_works" = yes; then
    AC_DEFINE([SO_SNDTIMEO_WORKS], [1], [Define if SO_SNDTIMEO works])
 fi
 
+if test "$ac_cv_so_rcvtimeo_works" = no ||
+   test "$ac_cv_so_sndtimeo_works" = no; then
+	AC_MSG_WARN([connection timeouts will not work])
+fi
+
 # Run-time directory
 VARNISH_STATE_DIR='${localstatedir}/varnish'
 AC_SUBST(VARNISH_STATE_DIR)
@@ -182,21 +251,32 @@ DEVELOPER_CFLAGS="-Wall -Wstrict-prototypes -Wmissing-prototypes -Wpointer-arith
 # Additional flags for GCC 4
 EXTRA_DEVELOPER_CFLAGS="-Wextra -Wno-missing-field-initializers -Wno-sign-compare"
 
+# --enable-developer-warnings
 AC_ARG_ENABLE(developer-warnings,
 	AS_HELP_STRING([--enable-developer-warnings],[enable strict warnings (default is NO)]),
 	CFLAGS="${CFLAGS} ${DEVELOPER_CFLAGS}")
+
+# --enable-debugging-symbols
 AC_ARG_ENABLE(debugging-symbols,
 	AS_HELP_STRING([--enable-debugging-symbols],[enable debugging symbols (default is NO)]),
 	CFLAGS="${CFLAGS} -O0 -g -fno-inline")
+
+# --enable-diagnostics
 AC_ARG_ENABLE(diagnostics,
 	AS_HELP_STRING([--enable-diagnostics],[enable run-time diagnostics (default is NO)]),
 	CFLAGS="${CFLAGS} -DDIAGNOSTICS")
+
+# --enable-extra-developer-warnings
 AC_ARG_ENABLE(extra-developer-warnings,
 	AS_HELP_STRING([--enable-extra-developer-warnings],[enable even stricter warnings (default is NO)]),
 	CFLAGS="${CFLAGS} ${EXTRA_DEVELOPER_CFLAGS}")
+
+# --enable-stack-protector
 AC_ARG_ENABLE(stack-protector,
 	AS_HELP_STRING([--enable-stack-protector],[enable stack protector (default is NO)]),
 	CFLAGS="${CFLAGS} -fstack-protector-all")
+
+# --enable-werror
 AC_ARG_ENABLE(werror,
 	AS_HELP_STRING([--enable-werror],[use -Werror (default is NO)]),
 	CFLAGS="${CFLAGS} -Werror")