Initial commit, passes a first test for reader.get().

.gitignore

+Makefile
+Makefile.in
+.deps/
+.libs/
+*.o
+*.lo
+*.la
+*.gcda
+*.gcno
+*~
+*.[1-9]
+.dirstamp
+
+/aclocal.m4
+/ar-lib
+/autom4te.cache/
+/compile
+/config.guess
+/config.h
+/config.h.in
+/config.log
+/config.status
+/config.sub
+/configure
+/depcomp
+/install-sh
+/libtool
+/ltmain.sh
+/missing
+/stamp-h1
+/test-driver
+/m4/
+
+/src/vcc_if.c
+/src/vcc_if.h
+/src/vmod_*rst
+
+/src/tests/*.log
+/src/tests/*.trs
+/src/test-suite.log
+
+/src/coverage

CONTRIBUTING.rst

+CONTRIBUTING
+============
+
+To contribute code or documentation, submit a pull request at the
+`source repository website
+<https://code.uplex.de/uplex-varnish/libvmod-file>`_.
+
+If you have a problem or discover a bug, you can post an `issue
+<https://code.uplex.de/uplex-varnish/libvmod-file/issues>`_ at
+the website. You can also write to <varnish-support@uplex.de>.
+
+For developers
+--------------
+
+The VMOD source code is in C, and compilation has been tested with gcc
+and clang. The code MUST always compile successfully with both of
+them.
+
+The build specifies C99 conformance for C sources (``-std=c99``). All
+compiler warnings are turned on, and all warnings are considered
+errors (``-Werror -Wall -Wextra``).  The code MUST always build
+without warnings or errors under these constraints.
+
+By default, ``CFLAGS`` is set to ``-g -O2``, so that symbols are
+included in the shared library, and optimization is at level
+``O2``. To change or disable these options, set ``CFLAGS`` explicitly
+before calling ``configure`` (it may be set to the empty string).
+
+For development/debugging cycles, the ``configure`` option
+``--enable-debugging`` is recommended (off by default). This will turn
+off optimizations and function inlining, so that a debugger will step
+through the code as expected.
+
+Experience has shown that adding ``-ggdb3`` to ``CFLAGS`` is
+beneficial if you need to examine the VMOD with the gdb debugger. The
+shared object for a VMOD is loaded from a directory relative to the
+Varnish home directory (by default ``/usr/local/var/$INSTANCE`` for
+development builds). A debugger needs to locate the shared object from
+that relative path to load its symbols, so the Varnish home directory
+should be the current working directory when the debugger is run. For
+example::
+
+  # To run gdb and examine a coredump
+  $ cd /usr/local/var/myinstance
+  $ gdb /usr/local/sbin/varnishd /path/to/coredump
+
+By default, the VMOD is built with the stack protector enabled
+(compile option ``-fstack-protector``), but it can be disabled with
+the ``configure`` option ``--disable-stack-protector``.

COPYING

+See LICENSE for details.
+

INSTALL.rst

+INSTALLATION
+============
+
+Building from source
+~~~~~~~~~~~~~~~~~~~~
+
+The VMOD is built against a Varnish installation, and the autotools
+use ``pkg-config(1)`` to locate the necessary header files and other
+resources. This sequence will install the VMOD::
+
+  > ./autogen.sh	# for builds from the git repo
+  > ./configure
+  > make
+  > make check		# to run unit tests in src/tests/*.vtc
+  > make distcheck	# run check and prepare a distribution tarball
+  > sudo make install
+
+See `CONTRIBUTING.rst <CONTRIBUTING.rst>`_ for notes about building
+from source.
+
+If you have installed Varnish in non-standard directories, call
+``autogen.sh`` and ``configure`` with the ``PKG_CONFIG_PATH``
+environment variable set to include the paths where the ``.pc`` file
+can be located for ``varnishapi``. For example, when varnishd
+configure was called with ``--prefix=$PREFIX``, use::
+
+  > PKG_CONFIG_PATH=${PREFIX}/lib/pkgconfig
+  > export PKG_CONFIG_PATH
+
+By default, the vmod ``configure`` script installs the vmod in
+the same directory as Varnish, determined via ``pkg-config(1)``. The
+vmod installation directory can be overridden by passing the
+``VMOD_DIR`` variable to ``configure``.
+
+Other files such as the man-page are installed in the locations
+determined by ``configure``, which inherits its default ``--prefix``
+setting from Varnish.

LICENSE

+Copyright (c) 2018 UPLEX Nils Goroll Systemoptimierung
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+1. Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.

Makefile.am

+ACLOCAL_AMFLAGS = -I m4 -I ${VARNISHAPI_DATAROOTDIR}/aclocal
+
+SUBDIRS = src
+
+DISTCHECK_CONFIGURE_FLAGS = \
+	VMOD_DIR='$${libdir}/varnish/vmods'
+
+coverage:
+	$(MAKE) $(AM_MAKEFLAGS) -C src coverage
+
+EXTRA_DIST = README.rst LICENSE COPYING CONTRIBUTING.rst INSTALL.rst
+
+doc_DATA = README.rst LICENSE COPYING CONTRIBUTING.rst INSTALL.rst
+
+README.rst: src/vmod_file.vcc
+	$(MAKE) $(AM_MAKEFLAGS) -C src vmod_file.man.rst
+	cp src/vmod_file.man.rst README.rst
+
+%.1 %.2 %.3 %.4 %.5 %.6 %.7 %.8 %.9:
+if HAVE_RST2MAN
+	${RST2MAN} $< $@
+else
+	@echo "========================================"
+	@echo "You need rst2man installed to make dist"
+	@echo "========================================"
+	@false
+endif

README.rst

+..
+.. NB:  This file is machine generated, DO NOT EDIT!
+..
+.. Edit vmod.vcc and run make instead
+..
+
+.. role:: ref(emphasis)
+
+=========
+VMOD file
+=========
+
+-----------------------------------------------------------------
+Varnish Module for reading files that may be updated at intervals
+-----------------------------------------------------------------
+
+:Manual section: 3
+
+
+SYNOPSIS
+========
+
+::
+
+  import file;
+
+  # VMOD version
+  STRING file.version()
+
+DESCRIPTION
+===========
+
+VMOD file is a Varnish module for reading the contents of a file and
+caching its contents, returning the contents for use in the Varnish
+Configuration Language (VCL), and checking if the file has changed
+after specified time intervals elapse. If the file has changed, then
+the new contents are read and cached, and are then available in VCL.
+
+XXX ...
+
+.. _file.reader():
+
+new xreader = file.reader(STRING name, DURATION ttl=120)
+--------------------------------------------------------
+
+XXX ...
+
+.. _xreader.get():
+
+STRING xreader.get()
+--------------------
+
+Retrieves the contents of file specified in the constructor. If the
+``ttl`` has elapsed, then ``.get()`` checks if the file has changed;
+if so, the new contents of the file are read, cached and returned. If
+the ``ttl`` has not elapsed, or if the file is unchanged, then the
+cached contents are returned.
+
+XXX ...
+
+.. _file.version():
+
+STRING version()
+----------------
+
+Return the version string for this VMOD.
+
+Example::
+
+  std.log("Using VMOD file version: " + file.version());
+
+ERRORS
+======
+
+XXX ...
+
+REQUIREMENTS
+============
+
+The VMOD requires the Varnish master branch. See the source repository for
+versions that are compatible with released Varnish versions.
+
+XXX ...
+
+INSTALLATION
+============
+
+See `INSTALL.rst <INSTALL.rst>`_ in the source repository.
+
+LIMITATIONS
+===========
+
+XXX ...
+
+SEE ALSO
+========
+
+* varnishd(1)
+* vcl(7)
+
+COPYRIGHT
+=========
+
+::
+
+  Copyright (c) 2019 UPLEX Nils Goroll Systemoptimierung
+  All rights reserved
+ 
+  Author: Geoffrey Simmons <geoffrey.simmons@uplex.de>
+ 
+  See LICENSE
+ 

autogen.sh

+#!/bin/sh
+
+warn() {
+	echo "WARNING: $@" 1>&2
+}
+
+case `uname -s` in
+Darwin)
+	LIBTOOLIZE=glibtoolize
+	;;
+FreeBSD)
+	LIBTOOLIZE=libtoolize
+	;;
+Linux)
+	LIBTOOLIZE=libtoolize
+	;;
+SunOS)
+	LIBTOOLIZE=libtoolize
+	;;
+*)
+	warn "unrecognized platform:" `uname -s`
+	LIBTOOLIZE=libtoolize
+esac
+
+automake_version=`automake --version | tr ' ' '\n' | egrep '^[0-9]\.[0-9a-z.-]+'`
+if [ -z "$automake_version" ] ; then
+	warn "unable to determine automake version"
+else
+	case $automake_version in
+		0.*|1.[0-8]|1.[0-8][.-]*)
+			warn "automake ($automake_version) detected; 1.9 or newer recommended"
+			;;
+		*)
+			;;
+	esac
+fi
+
+# check for varnishapi.m4 in custom paths
+dataroot=$(pkg-config --variable=datarootdir varnishapi 2>/dev/null)
+if [ -z "$dataroot" ] ; then
+	cat >&2 <<'EOF'
+Package varnishapi was not found in the pkg-config search path.
+Perhaps you should add the directory containing `varnishapi.pc'
+to the PKG_CONFIG_PATH environment variable
+EOF
+	exit 1
+fi
+set -ex
+aclocal -I m4 -I ${dataroot}/aclocal
+$LIBTOOLIZE --copy --force
+autoheader
+automake --add-missing --copy --foreign
+autoconf

configure.ac

+AC_PREREQ(2.68)
+AC_COPYRIGHT([Copyright (c) 2019 UPLEX - Nils Goroll Systemoptimierung])
+AC_INIT([libvmod-file], [trunk], [varnish-support@uplex.de], [vmod-file])
+AC_CONFIG_MACRO_DIR([m4])
+AC_CONFIG_SRCDIR(src/vmod_file.vcc)
+AM_CONFIG_HEADER(config.h)
+AC_CANONICAL_SYSTEM
+AC_LANG(C)
+
+AM_INIT_AUTOMAKE([1.12 -Wall -Werror foreign parallel-tests])
+AM_SILENT_RULES([yes])
+AM_PROG_AR
+
+LT_PREREQ([2.2.6])
+LT_INIT([dlopen disable-static])
+
+AC_PROG_CC
+AC_PROG_CC_STDC
+if test "x$ac_cv_prog_cc_c99" = xno; then
+	AC_MSG_ERROR([Could not find a C99 compatible compiler])
+fi
+AC_PROG_CPP
+
+AX_PTHREAD(,[AC_MSG_ERROR([Could not configure pthreads support])])
+
+LIBS="$PTHREAD_LIBS $LIBS"
+CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+CC="$PTHREAD_CC"
+
+AC_ARG_WITH([rst2man],
+	AS_HELP_STRING(
+		[--with-rst2man=PATH],
+		[Location of rst2man (auto)]),
+	[RST2MAN="$withval"],
+	AC_CHECK_PROGS(RST2MAN, [rst2man rst2man.py], []))
+AM_CONDITIONAL(HAVE_RST2MAN, [test "x$RST2MAN" != "xno"])
+
+AC_ARG_WITH([lcov],
+	AS_HELP_STRING(
+		[--with-lcov=PATH],
+		[Location of lcov to generate coverage data (auto)]),
+	[LCOV="$withval"],
+	AC_CHECK_PROGS(LCOV, [lcov], []))
+AM_CONDITIONAL(HAVE_LCOV, [test -n "$LCOV"])
+
+AC_ARG_WITH([genhtml],
+	AS_HELP_STRING(
+		[--with-genhtml=PATH],
+		[Location of genhtml to generate coverage reports (auto)]),
+	[GENHTML="$withval"],
+	AC_CHECK_PROGS(GENHTML, [genhtml], []))
+AM_CONDITIONAL(HAVE_GENHTML, [test -n "$GENHTML"])
+
+m4_ifndef([VARNISH_PREREQ], AC_MSG_ERROR([Need varnish.m4 -- see README.rst]))
+
+VARNISH_PREREQ([trunk])
+VARNISH_VMODS([file])
+
+VMOD_TESTS="$(cd $srcdir/src && echo tests/*.vtc)"
+AC_SUBST(VMOD_TESTS)
+
+PKG_CHECK_VAR([LIBVARNISHAPI_LIBDIR], [varnishapi], [libdir])
+AC_SUBST([VARNISH_LIBRARY_PATH],
+	[$LIBVARNISHAPI_LIBDIR:$LIBVARNISHAPI_LIBDIR/varnish])
+
+# Checks for C sources
+# XXX
+
+# --enable-stack-protector
+AC_ARG_ENABLE(stack-protector,
+	AS_HELP_STRING([--enable-stack-protector],[enable stack protector (default is YES)]),
+	[],
+	[enable_stack_protector=yes])
+
+if test "x$enable_stack_protector" != "xno"; then
+	AX_CHECK_COMPILE_FLAG([-fstack-protector],
+		AX_CHECK_LINK_FLAG([-fstack-protector],
+			[CFLAGS="${CFLAGS} -fstack-protector"], [], []),
+		[], [])
+fi
+
+# --enable-debugging
+AC_ARG_ENABLE(debugging,
+	AS_HELP_STRING([--enable-debugging],[enable debugging (default is NO)]),
+	[],
+	[enable_debugging=no])
+
+# AC_PROG_CC sets CFLAGS to '-g -O2' unless already set, so there's no
+# need to add -g. Disable or change by explicitly setting CFLAGS. If
+# this option is enabled, then -Og or -O0 becomes the last
+# optimization option, and hence takes precedence.
+if test "x$enable_debugging" != "xno"; then
+	CFLAGS="${CFLAGS} -fno-inline"
+	AX_CHECK_COMPILE_FLAG([-Og],
+		[CFLAGS="${CFLAGS} -O0 -Og"],
+		[CFLAGS="${CFLAGS} -O0"],
+		[])
+fi
+
+AC_CONFIG_FILES([
+	Makefile
+	src/Makefile
+])
+AC_OUTPUT

src/.dir-locals.el

+((nil . ((indent-tabs-mode . t)))
+ (c-mode . ((c-file-style . "BSD"))))

src/Makefile.am

+AUTOMAKE_OPTIONS = subdir-objects
+
+AM_CFLAGS = $(VARNISHAPI_CFLAGS) -Wall -Werror -Wextra -std=c99
+AM_LDFLAGS = $(VARNISHAPI_LIBS) -ldl
+
+vmod_LTLIBRARIES = libvmod_file.la
+
+libvmod_file_la_SOURCES = \
+	vmod_file.c
+
+nodist_libvmod_file_la_SOURCES = \
+	vcc_if.c \
+	vcc_if.h
+
+vmod_file.lo: $(nodist_libvmod_file_la_SOURCES)
+
+dist_man_MANS = vmod_file.3
+
+vcc_if.h vmod_file.rst vmod_file.man.rst: vcc_if.c
+
+vcc_if.c: vmod_file.vcc
+	$(AM_V_VMODTOOL) $(PYTHON) $(VMODTOOL) -o vcc_if $(srcdir)/vmod_file.vcc
+
+vmod_file.3: vmod_file.man.rst
+	$(AM_V_GEN) $(RST2MAN) vmod_file.man.rst vmod_file.3
+
+AM_TESTS_ENVIRONMENT = \
+	PATH="$(VMOD_TEST_PATH)" \
+	LD_LIBRARY_PATH="$(VARNISH_LIBRARY_PATH)"
+TEST_EXTENSIONS = .vtc
+VTC_LOG_COMPILER = varnishtest -v
+AM_VTC_LOG_FLAGS = -Dvmod_file="$(VMOD_FILE)"
+TESTS = @VMOD_TESTS@
+
+# To test an individual VTC test named test.vtc:
+# $ cd src/
+# $ make check TESTS=tests/test.vtc
+
+gcov: clean
+	$(AM_V_at)$(MAKE) $(AM_MAKEFLAGS) CC=gcc \
+		CFLAGS="${AM_CFLAGS} --coverage -fno-inline -g -O0" check
+
+# Set QUIET=-q for non-verbose builds, otherwise set to empty.
+QUIET_0 = -q
+QUIET_ = $(QUIET_@AM_DEFAULT_V@)
+QUIET = $(QUIET_@AM_V@)
+
+coverage/lcov.info: gcov
+if HAVE_LCOV
+	$(AM_V_at)@mkdir $(builddir)/coverage
+	$(AM_V_GEN) $(LCOV) $(QUIET) -c -d . -o  $(builddir)/coverage/lcov.info
+else
+	@echo "================================================="
+	@echo "You need lcov installed to generate coverage data"
+	@echo "================================================="
+	@false
+endif
+
+coverage: coverage/lcov.info
+if HAVE_GENHTML
+	$(AM_V_GEN) $(GENHTML) $(QUIET) $(builddir)/coverage/lcov.info \
+		-o  $(builddir)/coverage
+else
+	@echo "======================================================="
+	@echo "You need genhtml installed to generate coverage reports"
+	@echo "======================================================="
+	@false
+endif
+
+EXTRA_DIST = \
+	vmod_file.vcc \
+	$(VMOD_TESTS)
+
+CLEANFILES = \
+	$(builddir)/vcc_if.c \
+	$(builddir)/vcc_if.h \
+	$(builddir)/vmod_file.rst \
+	$(builddir)/vmod_file.man.rst \
+	$(builddir)/vmod_file.3 \
+	$(builddir)/*.gcda \
+	$(builddir)/*.gcno
+
+clean-local:
+	@rm -rf $(builddir)/coverage

src/tests/00basic.vtc

+# looks like -*- vcl -*-
+
+varnishtest "vcl.use and .discard, and version strings"
+
+varnish v1 -vcl {
+	import ${vmod_file};
+	backend b { .host = "${bad_ip}"; }
+} -start
+
+varnish v1 -vcl {backend b { .host = "${bad_ip}"; }}
+
+varnish v1 -cli "vcl.list"
+varnish v1 -cli "vcl.use vcl1"
+
+varnish v1 -cli "vcl.use vcl2"
+varnish v1 -cli "vcl.use vcl1"
+
+varnish v1 -cli "vcl.show vcl1"
+varnish v1 -cli "vcl.use vcl2"
+varnish v1 -cli "vcl.discard vcl1"
+varnish v1 -cli "vcl.list"
+
+varnish v1 -vcl {
+	import ${vmod_file};
+	backend b { .host = "${bad_ip}"; }
+
+	sub vcl_recv {
+		return(synth(200));
+	}
+
+	sub vcl_synth {
+		set resp.http.x-version = file.version();
+		if (!resp.http.x-version) {
+			set resp.status = 500;
+		}
+		return(deliver);
+	}
+}
+
+client c1 {
+	txreq -url "/"
+	rxresp
+	expect resp.status == 200
+	expect resp.http.x-version ~ "^.+$"
+} -run

src/tests/get.vtc

+# looks like -*- vcl -*-
+
+varnishtest "reader constructor and .get()"
+
+shell {echo "foo bar baz quux" > ${tmpdir}/file}
+
+varnish v1 -vcl+backend {
+	import ${vmod_file};
+	backend b { .host = "${bad_ip}"; }
+
+	sub vcl_init {
+		new rdr = file.reader("${tmpdir}/file");
+	}
+
+	sub vcl_recv {
+		return (synth(200));
+	}
+
+	sub vcl_synth {
+		set resp.http.Get = rdr.get();
+		return (deliver);
+	}
+} -start
+
+client c1 {
+	txreq
+	rxresp
+	expect resp.status == 200
+	expect resp.http.Get == "foo bar baz quux"
+} -run

src/vmod_file.c

+/*-
+ * Copyright (c) 2018 UPLEX Nils Goroll Systemoptimierung
+ * All rights reserved
+ *
+ * Author: Geoffrey Simmons <geoffrey.simmons@uplex.de>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/* for strdup() */
+#define _POSIX_C_SOURCE 200809L
+
+#include "config.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "cache/cache.h"
+#include "vcl.h"
+
+#include "vcc_if.h"
+
+#define VFAIL(ctx, fmt, ...) \
+        VRT_fail((ctx), "vmod file failure: " fmt, __VA_ARGS__)
+
+struct file_info {
+	unsigned	magic;
+#define FILE_INFO_MAGIC 0x46ebec3d
+	struct timespec	mtime;
+	dev_t		dev;
+	ino_t		ino;
+};
+
+struct VPFX(file_reader) {
+	unsigned		magic;
+#define FILE_READER_MAGIC 0x08d18e5b
+	struct file_info	*info;
+	char			*vcl_name;
+	char			*path;
+	char			*addr;
+	size_t			len;
+	VCL_DURATION		ttl;
+	VCL_TIME		t_expire;
+};
+
+static inline int
+do_stat(VRT_CTX, struct VPFX(file_reader) *rdr, struct stat *st,
+	const char *method)
+{
+	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
+	CHECK_OBJ_NOTNULL(rdr, FILE_READER_MAGIC);
+	AN(st);
+	
+	errno = 0;
+	if (stat(rdr->path, st) != 0) {
+		VFAIL(ctx, "%s.%s(): cannot read info about %s: %s",
+		      rdr->vcl_name, method,  rdr->path, vstrerror(errno));
+		return (-1);
+	}
+
+	if (!S_ISREG(st->st_mode)) {
+		VFAIL(ctx, "%s.%s(): %s is not a regular file", rdr->vcl_name,
+		      method, rdr->path);
+		return (-1);
+	}
+	return (0);
+}
+
+static int
+update_map(VRT_CTX, struct VPFX(file_reader) *rdr, struct stat *st,
+	   const char *method)
+{
+	struct file_info *info;
+	int fd;
+	void *addr;
+
+	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
+	CHECK_OBJ_NOTNULL(rdr, FILE_READER_MAGIC);
+	CHECK_OBJ_NOTNULL(rdr->info, FILE_INFO_MAGIC);
+	AN(st);
+	info = rdr->info;
+
+	errno = 0;
+	if ((fd = open(rdr->path, O_RDWR)) < 0) {
+		VFAIL(ctx, "%s.%s(): cannot open %s: %s", rdr->vcl_name, method,
+		      rdr->path, vstrerror(errno));
+		return (-1);
+	}
+
+	errno = 0;
+	if ((addr = mmap(NULL, st->st_size + 1, PROT_READ|PROT_WRITE,
+			 MAP_PRIVATE, fd, 0)) == MAP_FAILED) {
+		VFAIL(ctx, "%s.%s(): could not map %s: %s", rdr->vcl_name,
+		      method, rdr->path, vstrerror(errno));
+		closefd(&fd);
+		return (-1);
+	}
+	closefd(&fd);
+
+	/*
+	 * Add a terminating null byte, so that the mapped file can be
+	 * used as a VCL_STRING or a C string.
+	 */
+	*((char *)(addr + st->st_size)) = '\0';
+
+	info->mtime.tv_sec = st->st_mtim.tv_sec;
+	info->mtime.tv_nsec = st->st_mtim.tv_nsec;
+	info->dev = st->st_dev;
+	info->ino = st->st_ino;
+
+	rdr->addr = addr;
+	rdr->len = st->st_size + 1;
+	return (0);
+}
+
+VCL_VOID
+vmod_reader__init(VRT_CTX, struct VPFX(file_reader) **rdrp,
+		  const char *vcl_name, struct vmod_priv *priv,
+		  VCL_STRING name, VCL_DURATION ttl)
+{
+	struct VPFX(file_reader) *rdr;
+	struct file_info *info;
+	struct stat st;