tlsdated: support config files

The config file is a list of key/value pairs, separated by whitespace.

Signed-off-by: Elly Fong-Jones <ellyjones@chromium.org>

CHANGELOG

@@ -11,6 +11,7 @@
   Don't hardfail if DEFAULT_RTC_DEVICE cannot be opened, even if desired
   Support -j to add jitter to tlsdated time checks.
   Exponential backoff when tls connections fail.
+  Add config file support (have a look at man/tlsdated.conf.5)
 0.0.4 Wed 7 Nov, 2012
   Fixup CHANGELOG and properly tag
     Version Numbers Are Free! Hooray!

Makefile.am

@@ -57,12 +57,16 @@ certdir =  @TLSDATE_CA_ROOTS@
 cert_DATA = ca-roots/tlsdate-ca-roots.conf
 EXTRA_DIST+= $(cert_DATA)
 
+confdir = @TLSDATE_CONF_DIR@
+conf_DATA = etc/tlsdated.conf
+EXTRA_DIST+= $(conf_DATA)
 
 # Our documentation
 man_MANS+= man/tlsdate.1
 man_MANS+= man/tlsdated.1
 man_MANS+= man/tlsdate-helper.1
 man_MANS+= man/tlsdate-routeup.1
+man_MANS+= man/tlsdated.conf.5
 EXTRA_DIST+= $(man_MANS)
 
 .PHONY: debian_orig git-tag git-push git-tag-debian deb really-clean valgrind_test
@@ -110,6 +114,7 @@ src/configmake.h: ${top_srcdir}/Makefile.in
 	@{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
 	  echo '#define TLSDATE_CONFIG "$(sysconfdir)/ca-roots/"'; \
 	  echo '#define TLSDATE_CERTFILE "$(sysconfdir)/tlsdate/ca-roots/tlsdate-ca-roots.conf"'; \
+	  echo '#define TLSDATE_CONF_DIR "$(sysconfdir)/tlsdate/"'; \
 	  echo '#define TLSDATE_HELPER "$(bindir)/tlsdate-helper"'; \
 	  echo '#define TLSDATE "$(bindir)/tlsdate"'; \
 	  echo '#define TLSDATED "$(bindir)/tlsdated"'; \

configure.ac

@@ -34,6 +34,10 @@ dnl Build up the directory we will use to install certs
 TLSDATE_CA_ROOTS="${sysconfdir}/$PACKAGE_NAME/ca-roots"
 AC_SUBST([TLSDATE_CA_ROOTS])
 
+dnl Place we install our config file
+TLSDATE_CONF_DIR="${sysconfdir}/$PACKAGE_NAME/"
+AC_SUBST([TLSDATE_CONF_DIR])
+
 dnl Required headers
 dnl First check to see if openssl is installed
 AC_CHECK_HEADERS([openssl/ssl.h], ,[AC_MSG_ERROR([OpenSSL is not installed, openssl/sslh is missing])])

etc/tlsdated.conf

@@ -0,0 +1,23 @@
+# tlsdated example config file
+# for boolean options, "yes" enables them, any other value disables them.
+# see tlsdated.conf(5) for details about the options
+
+base-path                          /var/cache/tlsdated
+dry-run                            no
+jitter                             0
+max-tries                          10
+min-steady-state-interval          86400
+should-load-disk                   yes
+should-netlink                     yes
+should-save-disk                   yes
+should-sync-hwclock                yes
+steady-state-interval              86400
+subprocess-tries                   10
+subprocess-wait-between-tries      3
+verbose                            yes
+wait-between-tries                 10
+
+# Host configuration.
+host www.ptb.de
+port 443
+proxy none

man/tlsdated.1

@@ -48,6 +48,8 @@ add up to n seconds of jitter to steady-state fetches
 be verbose
 .IP "\-h"
 print help message
+.IP "\-f [/path/to/config/file]"
+use alternate config file
 .IP "[tlsdate command]"
 arguments to be passed to tlsdate at launch time
 

man/tlsdated.conf.5

@@ -0,0 +1,65 @@
+.\" Process this file with
+.\" groff -man -Tascii foo.1
+.\"
+.TH TLSDATED 5 "JANUARY 2013" "File Formats and Conversions"
+.SH NAME
+tlsdated.conf \- tlsdated config file
+.SH SYNTAX
+\fBtlsdated.conf\fR is the configuration file for the \fBtlsdated(1)\fR daemon.
+The config file is formatted as a list of key-value pairs, one per line,
+separated by whitespace. Whitespace inside values is preserved, so
+.RS
+foo   bar baz quxx
+.RE
+represents the key \fBfoo\fR mapping to the value \fBbar baz quxx\fR. Empty
+lines and lines beginning with \fB#\fR are ignored; leading whitespace on lines
+is stripped. For boolean options, the value \fByes\fR or no value at all
+indicates that the option should be switched on, and all other values indicate
+that the option should be switched off. \fINote that trailing whitespace is
+preserved in values.\fR
+.SH OPTIONS
+.IP argv (string)
+Add an argument to the subprocess's argument vector. Use this option multiple
+times for multiple arguments.
+.IP base-path (string)
+Sets the path to tlsdated's cache directory.
+.IP dry-run (bool)
+If enabled, don't actually adjust the system time.
+.IP jitter (int)
+Add or subtract up to this many seconds from the steady-state interval when
+checking. This helps prevent correlation between sequential checks and smooth
+load on time hosts.
+.IP max-tries (int)
+How many times to try running the tlsdate subprocess.
+.IP min-steady-state-interval (int)
+Do not check more than once this many seconds when in steady state.
+.IP should-load-disk (bool)
+If enabled, try loading the current timestamp out of the cache directory.
+.IP should-netlink (bool)
+If enabled, use a netlink socket to get network events; otherwise, read network
+events from stdin.
+.IP should-save-disk (bool)
+If enabled, save the current timestamp to the cache directory every so often and
+at exit.
+.IP should-sync-hwclock (bool)
+If enabled, set the hwclock to the fetched time.
+.IP steady-state-interval (int)
+Check at least once this many seconds when in steady state.
+.IP subprocess-tries (int)
+How many times to try waiting for the subprocess.
+.IP subprocess-wait-between-tries (int)
+How many seconds to wait between each attempt to wait for the subprocess.
+.IP verbose (bool)
+If enabled, tlsdated will be annoyingly verbose in syslog and on stdout.
+.IP wait-between-tries (int)
+How long to wait between runs of the subprocess.
+.SH BUGS
+It's likely! Let us know by contacting jacob@appelbaum.net
+
+Note that
+.B tlsdated(1)
+is still in Alpha, and may not work as expected.
+.SH AUTHOR
+Jacob Appelbaum <jacob at appelbaum dot net>
+.SH "SEE ALSO"
+.B tlsdated(1),

src/conf-unittest.c

@@ -0,0 +1,79 @@
+/*
+ * conf-unittest.c - config parser unit tests
+ * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "conf.h"
+#include "test_harness.h"
+
+FILE *fopenstr(const char *str) {
+  /* strlen(str) instead of strlen(str) + 1 because files shouldn't appear
+   * null-terminated. Cast away constness because we're in read mode, but the
+   * fmemopen prototype has no way to express that. */
+  return fmemopen((char *)str, strlen(str), "r");
+}
+
+TEST(parse_empty) {
+  /* can't do a truly empty file - fmemopen() combusts */
+  FILE *f = fopenstr("\n");
+  ASSERT_NE(NULL, f);
+  struct conf_entry *e = conf_parse(f);
+  EXPECT_NULL(e);
+  conf_free(e);
+}
+
+TEST(parse_basic) {
+  FILE *f = fopenstr("foo bar\nbaz quxx\n");
+  ASSERT_NE(NULL, f);
+  struct conf_entry *e = conf_parse(f);
+  ASSERT_NE(NULL, e);
+  EXPECT_STREQ(e->key, "foo");
+  EXPECT_STREQ(e->value, "bar");
+  ASSERT_NE(NULL, e->next);
+  EXPECT_STREQ(e->next->key, "baz");
+  EXPECT_STREQ(e->next->value, "quxx");
+  ASSERT_NULL(e->next->next);
+  conf_free(e);
+}
+
+TEST(parse_novalue) {
+  FILE *f = fopenstr("abcdef\n");
+  ASSERT_NE(NULL, f);
+  struct conf_entry *e = conf_parse(f);
+  ASSERT_NE(NULL, e);
+  EXPECT_STREQ(e->key, "abcdef");
+  EXPECT_NULL(e->value);
+  EXPECT_NULL(e->next);
+  conf_free(e);
+}
+
+TEST(parse_whitespace) {
+  FILE *f = fopenstr("         fribble		  grotz  \n");
+  ASSERT_NE(NULL, f);
+  struct conf_entry *e = conf_parse(f);
+  ASSERT_NE(NULL, e);
+  EXPECT_STREQ(e->key, "fribble");
+  EXPECT_STREQ(e->value, "grotz  ");
+  EXPECT_NULL(e->next);
+  conf_free(e);
+}
+
+TEST(parse_comment) {
+  FILE *f = fopenstr("#foo bar\nbaz quxx\n");
+  ASSERT_NE(NULL, f);
+  struct conf_entry *e = conf_parse(f);
+  ASSERT_NE(NULL, e);
+  EXPECT_STREQ(e->key, "baz");
+  EXPECT_STREQ(e->value, "quxx");
+  EXPECT_NULL(e->next);
+  conf_free(e);
+}
+
+TEST_HARNESS_MAIN

src/conf.c

@@ -0,0 +1,86 @@
+/* conf.c - config file parser */
+
+#define _GNU_SOURCE /* strchrnul */
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "conf.h"
+
+void strip_newlines(char *line)
+{
+  *strchrnul(line, '\n') = '\0';
+  *strchrnul(line, '\r') = '\0';
+}
+
+char *eat_whitespace(char *line)
+{
+  while (isspace(*line))
+    line++;
+  return line;
+}
+
+int is_ignored_line(char *line)
+{
+  return !*line || *line == '#';
+}
+
+struct conf_entry *conf_parse(FILE *f)
+{
+  struct conf_entry *head = NULL;
+  struct conf_entry *tail = NULL;
+  char buf[CONF_MAX_LINE];
+
+  while (fgets(buf, sizeof(buf), f)) {
+    struct conf_entry *e;
+    char *start = buf;
+    char *key;
+    char *val;
+
+    strip_newlines(start);
+    start = eat_whitespace(start);
+    if (is_ignored_line(start))
+      continue;
+
+    key = strtok(start, " \t");
+    val = strtok(NULL, "");
+    if (val)
+      val = eat_whitespace(val);
+    e = malloc(sizeof *e);
+    if (!e)
+      goto fail;
+    e->next = NULL;
+    e->key = strdup(key);
+    e->value = val ? strdup(val) : NULL;
+    if (!e->key || (val && !e->value)) {
+      free(e->key);
+      free(e->value);
+      goto fail;
+    }
+    if (!head) {
+      head = e;
+      tail = e;
+    } else {
+      tail->next = e;
+      tail = e;
+    }
+  }
+
+  return head;
+fail:
+  conf_free(head);
+  return NULL;
+}
+
+void conf_free(struct conf_entry *e)
+{
+  struct conf_entry *n;
+  while (e) {
+    n = e->next;
+    free(e->key);
+    free(e->value);
+    free(e);
+    e = n;
+  }
+}

src/conf.h

@@ -0,0 +1,19 @@
+/* conf.h - config file parser */
+
+#ifndef CONF_H
+#define CONF_H
+
+#include <stdio.h>
+
+#define CONF_MAX_LINE 16384
+
+struct conf_entry {
+	struct conf_entry *next;
+	char *key;
+	char *value;
+};
+
+struct conf_entry *conf_parse(FILE *f);
+void conf_free(struct conf_entry *e);
+
+#endif /* !CONF_H */

src/include.am

@@ -9,6 +9,11 @@ bin_PROGRAMS+= src/tlsdate-helper
 bin_PROGRAMS+= src/tlsdated
 bin_PROGRAMS+= src/tlsdate-dbus-announce
 
+src_conf_unittest_SOURCES = src/conf.c
+src_conf_unittest_SOURCES+= src/conf-unittest.c
+check_PROGRAMS+= src/conf_unittest
+noinst_PROGRAMS+= src/conf_unittest
+
 src_tlsdate_routeup_CFLAGS = -DROUTEUP_MAIN
 src_tlsdate_routeup_SOURCES = src/routeup.c
 src_tlsdate_routeup_SOURCES+= src/util.c
@@ -23,7 +28,8 @@ src_tlsdate_helper_SOURCES+= src/util.c
 
 src_tlsdated_CFLAGS = -DTLSDATED_MAIN
 src_tlsdated_LDADD = -lcrypto
-src_tlsdated_SOURCES = src/routeup.c
+src_tlsdated_SOURCES = src/conf.c
+src_tlsdated_SOURCES+= src/routeup.c
 src_tlsdated_SOURCES+= src/tlsdated.c
 src_tlsdated_SOURCES+= src/util.c
 

src/tlsdate.h

@@ -20,13 +20,15 @@
 
 #define DEFAULT_HOST "www.ptb.de"
 #define DEFAULT_PORT "443"
+#define DEFAULT_PROXY "none"
 #define DEFAULT_PROTOCOL "tlsv1"
 #define DEFAULT_CERTDIR "/etc/ssl/certs"
 #define DEFAULT_CERTFILE TLSDATE_CERTFILE
 #define DEFAULT_DAEMON_CACHEDIR "/var/cache/tlsdated"
 #define DEFAULT_DAEMON_TMPSUFFIX ".new"
 #define DEFAULT_TLSDATE TLSDATE
 #define DEFAULT_RTC_DEVICE "/dev/rtc"
+#define DEFAULT_CONF_FILE TLSDATE_CONF_DIR "tlsdated.conf"
 
 /* tlsdated magic numbers */
 #define MAX_TRIES 10