From c054f90f029915679db24d61559a7bdde1a9414b Mon Sep 17 00:00:00 2001
From: Roger Dingledine <arma@torproject.org>
Date: Wed, 6 Feb 2008 12:46:17 +0000
Subject: [PATCH] New config option ServerDNSAllowBrokenResolvConf to start a
 relay even when the local resolv.conf file is missing, broken, or contains
 only unusable nameservers.

Now I can run a local network on my laptop when I'm on an airplane.


svn:r13402
---
 src/or/config.c |  3 ++-
 src/or/dns.c    | 10 +++++-----
 src/or/or.h     |  4 ++++
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/or/config.c b/src/or/config.c
index cca9a3c402..522e0c06fc 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -265,6 +265,7 @@ static config_var_t _option_vars[] = {
   V(RunTesting,                  BOOL,     "0"),
   V(SafeLogging,                 BOOL,     "1"),
   V(SafeSocks,                   BOOL,     "0"),
+  V(ServerDNSAllowBrokenResolvConf, BOOL,  "0"),
   V(ServerDNSAllowNonRFC953Hostnames, BOOL,"0"),
   V(ServerDNSDetectHijacking,    BOOL,     "1"),
   V(ServerDNSResolvConfFile,     STRING,   NULL),
@@ -3252,7 +3253,7 @@ options_validate(or_options_t *old_options, or_options_t *options,
 
   if (options->V3AuthVoteDelay + options->V3AuthDistDelay >=
       options->V3AuthVotingInterval/2) {
-    REJECT("V3AuthVoteDelay and V3AuthDistDelay must be no more than half "
+    REJECT("V3AuthVoteDelay plus V3AuthDistDelay must be less than half "
            "V3AuthVotingInterval");
   }
   if (options->V3AuthVoteDelay < MIN_VOTE_SECONDS)
diff --git a/src/or/dns.c b/src/or/dns.c
index 79af4f0607..e1a56e4c1f 100644
--- a/src/or/dns.c
+++ b/src/or/dns.c
@@ -1108,7 +1108,7 @@ configure_nameservers(int force)
     if (stat(conf_fname, &st)) {
       log_warn(LD_EXIT, "Unable to stat resolver configuration in '%s': %s",
                conf_fname, strerror(errno));
-      return -1;
+      return options->ServerDNSAllowBrokenResolvConf ? 0 : -1;
     }
     if (!force && resolv_conf_fname && !strcmp(conf_fname,resolv_conf_fname)
         && st.st_mtime == resolv_conf_mtime) {
@@ -1123,11 +1123,11 @@ configure_nameservers(int force)
     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 -1;
+      return options->ServerDNSAllowBrokenResolvConf ? 0 : -1;
     }
     if (evdns_count_nameservers() == 0) {
       log_warn(LD_EXIT, "Unable to find any nameservers in '%s'.", conf_fname);
-      return -1;
+      return options->ServerDNSAllowBrokenResolvConf ? 0 : -1;
     }
     tor_free(resolv_conf_fname);
     resolv_conf_fname = tor_strdup(conf_fname);
@@ -1143,13 +1143,13 @@ configure_nameservers(int force)
     }
     if (evdns_config_windows_nameservers())  {
       log_warn(LD_EXIT,"Could not config nameservers.");
-      return -1;
+      return options->ServerDNSAllowBrokenResolvConf ? 0 : -1;
     }
     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 -1;
+      return options->ServerDNSAllowBrokenResolvConf ? 0 : -1;
     }
     if (nameservers_configured)
       evdns_resume();
diff --git a/src/or/or.h b/src/or/or.h
index 9ec57784fd..c2c4c0c560 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -2291,6 +2291,10 @@ typedef struct {
   char *ServerDNSResolvConfFile; /**< If provided, we configure our internal
                      * resolver from the file here rather than from
                      * /etc/resolv.conf (Unix) or the registry (Windows). */
+  /** Boolean: if set, we start even if our resolv.conf file is missing
+   * or broken. */
+  int ServerDNSAllowBrokenResolvConf;
+
   smartlist_t *ServerDNSTestAddresses; /**< A list of addresses that definitely
                                         * should be resolveable. Used for
                                         * testing our DNS server. */