[or-cvs] r17623: {tor} Backport bug 691 fix: do not shutdown Tor servers right away (in tor/branches/tor-0_2_0-patches: . src/or)
nickm at seul.org
nickm at seul.org
Sun Dec 14 17:48:41 UTC 2008
Author: nickm
Date: 2008-12-14 12:48:37 -0500 (Sun, 14 Dec 2008)
New Revision: 17623
Modified:
tor/branches/tor-0_2_0-patches/ChangeLog
tor/branches/tor-0_2_0-patches/src/or/config.c
tor/branches/tor-0_2_0-patches/src/or/dns.c
tor/branches/tor-0_2_0-patches/src/or/main.c
tor/branches/tor-0_2_0-patches/src/or/or.h
tor/branches/tor-0_2_0-patches/src/or/router.c
Log:
Backport bug 691 fix: do not shutdown Tor servers right away if the network is down.
Modified: tor/branches/tor-0_2_0-patches/ChangeLog
===================================================================
--- tor/branches/tor-0_2_0-patches/ChangeLog 2008-12-14 17:34:47 UTC (rev 17622)
+++ tor/branches/tor-0_2_0-patches/ChangeLog 2008-12-14 17:48:37 UTC (rev 17623)
@@ -12,6 +12,10 @@
Bugfix on 0.2.0.3-alpha.
- Fix a hard-to-trigger resource leak when logging credential status.
CID 349.
+ - When we can't initialize DNS because the network is down, do not
+ automatically stop Tor from starting. Instead, we retry failed
+ dns_inits() every 10 minutes, and change the exit policy to reject *:*
+ until one succeeds. Fixes bug 691.
o Minor features:
- Report the case where all signatures in a detached set are rejected
Modified: tor/branches/tor-0_2_0-patches/src/or/config.c
===================================================================
--- tor/branches/tor-0_2_0-patches/src/or/config.c 2008-12-14 17:34:47 UTC (rev 17622)
+++ tor/branches/tor-0_2_0-patches/src/or/config.c 2008-12-14 17:48:37 UTC (rev 17623)
@@ -271,7 +271,7 @@
V(RunTesting, BOOL, "0"),
V(SafeLogging, BOOL, "1"),
V(SafeSocks, BOOL, "0"),
- V(ServerDNSAllowBrokenResolvConf, BOOL, "0"),
+ V(ServerDNSAllowBrokenResolvConf, BOOL, "1"),
V(ServerDNSAllowNonRFC953Hostnames, BOOL,"0"),
V(ServerDNSDetectHijacking, BOOL, "1"),
V(ServerDNSResolvConfFile, STRING, NULL),
Modified: tor/branches/tor-0_2_0-patches/src/or/dns.c
===================================================================
--- tor/branches/tor-0_2_0-patches/src/or/dns.c 2008-12-14 17:34:47 UTC (rev 17622)
+++ tor/branches/tor-0_2_0-patches/src/or/dns.c 2008-12-14 17:48:37 UTC (rev 17623)
@@ -33,6 +33,8 @@
/** Have we currently configured nameservers with eventdns? */
static int nameservers_configured = 0;
+/** Did our most recent attempt to configure nameservers with eventdns fail? */
+static int nameserver_config_failed = 0;
/** What was the resolv_conf fname we last used when configuring the
* nameservers? Used to check whether we need to reconfigure. */
static char *resolv_conf_fname = NULL;
@@ -214,12 +216,20 @@
tor_free(resolv_conf_fname);
resolv_conf_mtime = 0;
} else {
- if (configure_nameservers(0) < 0)
+ if (configure_nameservers(0) < 0) {
return -1;
+ }
}
return 0;
}
+/**DOCDOC*/
+int
+has_dns_init_failed(void)
+{
+ return nameserver_config_failed;
+}
+
/** Helper: Given a TTL from a DNS response, determine what TTL to give the
* OP that asked us to resolve it. */
uint32_t
@@ -1100,10 +1110,11 @@
}
/** Configure eventdns nameservers if force is true, or if the configuration
- * has changed since the last time we called this function. On Unix, this
- * reads from options->ServerDNSResolvConfFile or /etc/resolv.conf; on
- * Windows, this reads from options->ServerDNSResolvConfFile or the registry.
- * Return 0 on success or -1 on failure. */
+ * has changed since the last time we called this function, or if we failed on
+ * our last attempt. On Unix, this reads from /etc/resolv.conf or
+ * options->ServerDNSResolvConfFile; on Windows, this reads from
+ * options->ServerDNSResolvConfFile or the registry. Return 0 on success or
+ * -1 on failure. */
static int
configure_nameservers(int force)
{
@@ -1123,7 +1134,7 @@
if (stat(conf_fname, &st)) {
log_warn(LD_EXIT, "Unable to stat resolver configuration in '%s': %s",
conf_fname, strerror(errno));
- return options->ServerDNSAllowBrokenResolvConf ? 0 : -1;
+ goto err;
}
if (!force && resolv_conf_fname && !strcmp(conf_fname,resolv_conf_fname)
&& st.st_mtime == resolv_conf_mtime) {
@@ -1138,11 +1149,11 @@
if ((r = evdns_resolv_conf_parse(DNS_OPTIONS_ALL, conf_fname))) {
log_warn(LD_EXIT, "Unable to parse '%s', or no nameservers in '%s' (%d)",
conf_fname, conf_fname, r);
- return options->ServerDNSAllowBrokenResolvConf ? 0 : -1;
+ goto err;
}
if (evdns_count_nameservers() == 0) {
log_warn(LD_EXIT, "Unable to find any nameservers in '%s'.", conf_fname);
- return options->ServerDNSAllowBrokenResolvConf ? 0 : -1;
+ goto err;
}
tor_free(resolv_conf_fname);
resolv_conf_fname = tor_strdup(conf_fname);
@@ -1158,13 +1169,12 @@
}
if (evdns_config_windows_nameservers()) {
log_warn(LD_EXIT,"Could not config nameservers.");
- return options->ServerDNSAllowBrokenResolvConf ? 0 : -1;
+ goto err;
}
if (evdns_count_nameservers() == 0) {
log_warn(LD_EXIT, "Unable to find any platform nameservers in "
- "your Windows configuration. Perhaps you should list a "
- "ServerDNSResolvConfFile file in your torrc?");
- return options->ServerDNSAllowBrokenResolvConf ? 0 : -1;
+ "your Windows configuration.");
+ goto err;
}
if (nameservers_configured)
evdns_resume();
@@ -1184,7 +1194,18 @@
dns_servers_relaunch_checks();
nameservers_configured = 1;
+ if (nameserver_config_failed) {
+ nameserver_config_failed = 0;
+ mark_my_descriptor_dirty();
+ }
return 0;
+ err:
+ nameservers_configured = 0;
+ if (! nameserver_config_failed) {
+ nameserver_config_failed = 1;
+ mark_my_descriptor_dirty();
+ }
+ return -1;
}
/** For eventdns: Called when we get an answer for a request we launched.
@@ -1275,8 +1296,9 @@
if (!nameservers_configured) {
log_warn(LD_EXIT, "(Harmless.) Nameservers not configured, but resolve "
"launched. Configuring.");
- if (configure_nameservers(1) < 0)
+ if (configure_nameservers(1) < 0) {
return -1;
+ }
}
r = parse_inaddr_arpa_address(exitconn->_base.address, &in);
Modified: tor/branches/tor-0_2_0-patches/src/or/main.c
===================================================================
--- tor/branches/tor-0_2_0-patches/src/or/main.c 2008-12-14 17:34:47 UTC (rev 17622)
+++ tor/branches/tor-0_2_0-patches/src/or/main.c 2008-12-14 17:48:37 UTC (rev 17623)
@@ -832,6 +832,7 @@
static time_t time_to_clean_caches = 0;
static time_t time_to_recheck_bandwidth = 0;
static time_t time_to_check_for_expired_networkstatus = 0;
+ static time_t time_to_retry_dns_init = 0;
or_options_t *options = get_options();
int i;
int have_dir_info;
@@ -994,6 +995,14 @@
time_to_clean_caches = now + CLEAN_CACHES_INTERVAL;
}
+#define RETRY_DNS_INTERVAL (10*60)
+ /* If we're a server and initializing dns failed, retry periodically. */
+ if (time_to_retry_dns_init < now) {
+ time_to_retry_dns_init = now + RETRY_DNS_INTERVAL;
+ if (server_mode(options) && has_dns_init_failed())
+ dns_init();
+ }
+
/** How often do we check whether part of our router info has changed in a way
* that would require an upload? */
#define CHECK_DESCRIPTOR_INTERVAL (60)
@@ -1377,8 +1386,13 @@
/* initialize dns resolve map, spawn workers if needed */
if (dns_init() < 0) {
- log_err(LD_GENERAL,"Error initializing dns subsystem; exiting");
- return -1;
+ if (get_options()->ServerDNSAllowBrokenResolvConf)
+ log_warn(LD_GENERAL, "Couldn't set up any working nameservers. "
+ "Network not up yet? Will try again soon.");
+ else {
+ log_err(LD_GENERAL,"Error initializing dns subsystem; exiting. To "
+ "retry instead, set the ServerDNSAllowBrokenResolvConf option.");
+ }
}
handle_signals(1);
Modified: tor/branches/tor-0_2_0-patches/src/or/or.h
===================================================================
--- tor/branches/tor-0_2_0-patches/src/or/or.h 2008-12-14 17:34:47 UTC (rev 17622)
+++ tor/branches/tor-0_2_0-patches/src/or/or.h 2008-12-14 17:48:37 UTC (rev 17623)
@@ -3244,6 +3244,7 @@
/********************************* dns.c ***************************/
int dns_init(void);
+int has_dns_init_failed(void);
void dns_free_all(void);
uint32_t dns_clip_ttl(uint32_t ttl);
int dns_reset(void);
Modified: tor/branches/tor-0_2_0-patches/src/or/router.c
===================================================================
--- tor/branches/tor-0_2_0-patches/src/or/router.c 2008-12-14 17:34:47 UTC (rev 17622)
+++ tor/branches/tor-0_2_0-patches/src/or/router.c 2008-12-14 17:48:37 UTC (rev 17623)
@@ -1717,7 +1717,7 @@
}
/* Write the exit policy to the end of 's'. */
- if (dns_seems_to_be_broken() ||
+ if (dns_seems_to_be_broken() || has_dns_init_failed() ||
!router->exit_policy || !smartlist_len(router->exit_policy)) {
/* DNS is screwed up; don't claim to be an exit. */
strlcat(s+written, "reject *:*\n", maxlen-written);
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