[or-cvs] r8255: Make it possible to change nameserver options while Tor is r (in tor/trunk: . doc src/or)

nickm at seul.org nickm at seul.org
Mon Aug 28 03:15:56 UTC 2006


Author: nickm
Date: 2006-08-27 23:15:55 -0400 (Sun, 27 Aug 2006)
New Revision: 8255

Modified:
   tor/trunk/
   tor/trunk/doc/TODO
   tor/trunk/src/or/config.c
   tor/trunk/src/or/dns.c
   tor/trunk/src/or/eventdns.c
   tor/trunk/src/or/main.c
   tor/trunk/src/or/or.h
Log:
 r8608 at Kushana:  nickm | 2006-08-27 16:57:47 -0400
 Make it possible to change nameserver options while Tor is running.



Property changes on: tor/trunk
___________________________________________________________________
Name: svk:merge
   - 17f730b7-d419-0410-b50f-85ee4b70197a:/local/or/tor/trunk:8290
1f724f9b-111a-0410-b636-93f1a77c1813:/local/or/tor/trunk:8207
96637b51-b116-0410-a10e-9941ebb49b64:/tor/branches/spec:7005
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/eventdns:8607
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/mmap:7030
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/oo-connections:6950
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/trans-ap:7315
c95137ef-5f19-0410-b913-86e773d04f59:/tor/trunk:8576
   + 17f730b7-d419-0410-b50f-85ee4b70197a:/local/or/tor/trunk:8290
1f724f9b-111a-0410-b636-93f1a77c1813:/local/or/tor/trunk:8207
96637b51-b116-0410-a10e-9941ebb49b64:/tor/branches/spec:7005
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/eventdns:8608
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/mmap:7030
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/oo-connections:6950
c95137ef-5f19-0410-b913-86e773d04f59:/tor/branches/trans-ap:7315
c95137ef-5f19-0410-b913-86e773d04f59:/tor/trunk:8576

Modified: tor/trunk/doc/TODO
===================================================================
--- tor/trunk/doc/TODO	2006-08-28 03:15:50 UTC (rev 8254)
+++ tor/trunk/doc/TODO	2006-08-28 03:15:55 UTC (rev 8255)
@@ -100,7 +100,8 @@
         reload.
       o Fail when we have no configured nameservers!
       o Make it the default on platforms where it works.
-      - Make resolv.conf (or local equivalent) get checked on reload,
+      - Document SearchDomains, ResolvConf options
+      o Make resolv.conf (or local equivalent) get checked on reload,
         settable while running, etc.
       - Add ipv6 support; make API closer to getaddrinfo().  (i.e., allow a
         single AAAA/A query, return cname as well)

Modified: tor/trunk/src/or/config.c
===================================================================
--- tor/trunk/src/or/config.c	2006-08-28 03:15:50 UTC (rev 8254)
+++ tor/trunk/src/or/config.c	2006-08-28 03:15:55 UTC (rev 8255)
@@ -802,8 +802,13 @@
           inform_testing_reachability();
       }
       cpuworkers_rotate();
-      dnsworkers_rotate();
+      dns_reset();
     }
+#ifdef USE_EVENTDNS
+    else {
+      dns_reset();
+    }
+#endif
   }
 
   /* Check if we need to parse and add the EntryNodes config option. */
@@ -2555,6 +2560,7 @@
   if (!opt_streq(old_options->DataDirectory, new_options->DataDirectory) ||
       old_options->NumCpus != new_options->NumCpus ||
       old_options->ORPort != new_options->ORPort ||
+      old_options->SearchDomains != new_options->SearchDomains ||
       old_options->SafeLogging != new_options->SafeLogging ||
       !config_lines_eq(old_options->Logs, new_options->Logs))
     return 1;

Modified: tor/trunk/src/or/dns.c
===================================================================
--- tor/trunk/src/or/dns.c	2006-08-28 03:15:50 UTC (rev 8254)
+++ tor/trunk/src/or/dns.c	2006-08-28 03:15:55 UTC (rev 8255)
@@ -101,20 +101,28 @@
 static void send_resolved_cell(edge_connection_t *conn, uint8_t answer_type);
 static int launch_resolve(edge_connection_t *exitconn);
 #ifndef USE_EVENTDNS
+static void dnsworkers_rotate(void);
 static int dnsworker_main(void *data);
 static int spawn_dnsworker(void);
 static int spawn_enough_dnsworkers(void);
 #else
-static int configure_nameservers(void);
+static int configure_nameservers(int force);
 #endif
 #ifdef DEBUG_DNS_CACHE
 static void _assert_cache_ok(void);
 #define assert_cache_ok() _assert_cache_ok()
 #else
-#define assert_cache_ok() do {} while(0)
+#define assert_cache_ok() do {} while (0)
 #endif
 static void assert_resolve_ok(cached_resolve_t *resolve);
 
+#ifdef USE_EVENTDNS
+/* DOCDOC */
+static int nameservers_configured = 0;
+static char *resolv_conf_fname = NULL;
+static time_t resolv_conf_mtime = 0;
+#endif
+
 /** Hash table of cached_resolve objects. */
 static HT_HEAD(cache_map, cached_resolve_t) cache_root;
 
@@ -164,14 +172,37 @@
 dns_init(void)
 {
   init_cache_map();
-  dnsworkers_rotate();
 #ifdef USE_EVENTDNS
   if (server_mode(get_options()))
-    return configure_nameservers();
+    return configure_nameservers(1);
+#else
+  dnsworkers_rotate();
 #endif
   return 0;
 }
 
+/* DOCDOC */
+void
+dns_reset(void)
+{
+#ifdef USE_EVENTDNS
+  or_options_t *options = get_options();
+  if (! server_mode(options)) {
+    eventdns_clear_nameservers_and_suspend();
+    eventdns_search_clear();
+    nameservers_configured = 0;
+    tor_free(resolv_conf_fname);
+    resolv_conf_mtime = 0;
+  } else {
+    if (configure_nameservers(0) < 0)
+      /* XXXX */
+      return;
+  }
+#else
+  dnsworkers_rotate();
+#endif
+}
+
 uint32_t
 dns_clip_ttl(uint32_t ttl)
 {
@@ -910,7 +941,7 @@
 /** Close and re-open all idle dnsworkers; schedule busy ones to be closed
  * and re-opened once they're no longer busy.
  **/
-void
+static void
 dnsworkers_rotate(void)
 {
   connection_t *dnsconn;
@@ -1162,10 +1193,6 @@
       return 0;
   }
 }
-void
-dnsworkers_rotate(void)
-{
-}
 int
 connection_dns_finished_flushing(connection_t *conn)
 {
@@ -1187,26 +1214,37 @@
   tor_assert(0);
   return 0;
 }
-static int nameservers_configured = 0;
 
 /* DOCDOC */
 static int
-configure_nameservers(void)
+configure_nameservers(int force)
 {
   or_options_t *options;
   const char *conf_fname;
   struct stat st;
-  if (nameservers_configured)
-    return 0;
   options = get_options();
-  eventdns_set_log_fn(eventdns_log_cb);
-
   conf_fname = options->ResolvConf;
 #ifndef MS_WINDOWS
-  if (!conf_fname) conf_fname = "/etc/resolv.conf";
+  if (!conf_fname)
+    conf_fname = "/etc/resolv.conf";
 #endif
 
+  eventdns_set_log_fn(eventdns_log_cb);
   if (conf_fname) {
+    if (stat(conf_fname, &st)) {
+      log_warn(LD_EXIT, "Unable to stat resolver configuration in '%s'",
+               conf_fname);
+      return -1;
+    }
+    if (!force && resolv_conf_fname && !strcmp(conf_fname,resolv_conf_fname)
+        && st.st_mtime == resolv_conf_mtime) {
+      log_info(LD_EXIT, "No change to '%s'", conf_fname);
+      return 0;
+    }
+    if (nameservers_configured) {
+      eventdns_search_clear();
+      eventdns_clear_nameservers_and_suspend();
+    }
     log_info(LD_EXIT, "Parsing resolver configuration in '%s'", conf_fname);
     if (eventdns_resolv_conf_parse(DNS_OPTIONS_ALL, conf_fname))
       return -1;
@@ -1214,9 +1252,18 @@
       log_warn(LD_EXIT, "Unable to find any nameservers in '%s'.", conf_fname);
       return -1;
     }
+    tor_free(resolv_conf_fname);
+    resolv_conf_fname = tor_strdup(resolv_conf_fname);
+    resolv_conf_mtime = st.st_mtime;
+    if (nameservers_configured)
+      eventdns_resume();
   }
 #ifdef MS_WINDOWS
   else {
+    if (nameservers_configured) {
+      eventdns_search_clear();
+      eventdns_clear_nameservers_and_suspend();
+    }
     if (eventdns_config_windows_nameservers())
       return -1;
     if (eventdns_count_nameservers() == 0) {
@@ -1225,6 +1272,10 @@
                "ResolvConf file in your torrc?");
       return -1;
     }
+    if (nameservers_configured)
+      eventdns_resume();
+    tor_free(resolv_conf_fname);
+    resolv_conf_mtime = 0;
   }
 #endif
 
@@ -1275,7 +1326,7 @@
   int r;
   int options = get_options()->SearchDomains ? 0 : DNS_QUERY_NO_SEARCH;
   if (!nameservers_configured)
-    if (configure_nameservers() < 0)
+    if (configure_nameservers(1) < 0)
       return -1;
   log_info(LD_EXIT, "Launching eventdns request for %s",
            escaped_safe_str(exitconn->_base.address));
@@ -1338,3 +1389,4 @@
                              _compare_cached_resolves_by_expiry);
 }
 #endif
+

Modified: tor/trunk/src/or/eventdns.c
===================================================================
--- tor/trunk/src/or/eventdns.c	2006-08-28 03:15:50 UTC (rev 8254)
+++ tor/trunk/src/or/eventdns.c	2006-08-28 03:15:55 UTC (rev 8255)
@@ -553,7 +553,7 @@
 	global_good_nameservers--;
 	assert(global_good_nameservers >= 0);
 	if (global_good_nameservers == 0) {
-		log("All nameservers have failed");
+		log(1,"All nameservers have failed");
 	}
 
 	ns->state = 0;
@@ -561,8 +561,8 @@
 
 	evtimer_set(&ns->timeout_event, nameserver_prod_callback, ns);
 	if (evtimer_add(&ns->timeout_event, (struct timeval *) &global_nameserver_timeouts[0]) < 0) {
-          log("Error from libevent when adding timer event for %s",
-              debug_ntoa(ns->address));
+		log(1,"Error from libevent when adding timer event for %s",
+		    debug_ntoa(ns->address));
           // ???? Do more?
         }
 
@@ -910,7 +910,7 @@
 			}
                         // XXXX do something sane with malformed A answers.
 			addrcount = datalength >> 2;  // each IP address is 4 bytes
-			addrtocopy = MIN(MAX_ADDRS - reply.data.a.addrcount, addrcount);
+			addrtocopy = MIN(MAX_ADDRS - reply.data.a.addrcount, (unsigned)addrcount);
 			ttl_r = MIN(ttl_r, ttl);
 			// we only bother with the first four addresses.
 			if (j + 4*addrtocopy > length) return -1;
@@ -1390,7 +1390,6 @@
 	return 0;
 }
 
-
 // exported function
 int
 eventdns_resume(void)

Modified: tor/trunk/src/or/main.c
===================================================================
--- tor/trunk/src/or/main.c	2006-08-28 03:15:50 UTC (rev 8254)
+++ tor/trunk/src/or/main.c	2006-08-28 03:15:55 UTC (rev 8255)
@@ -1081,7 +1081,7 @@
     /* Restart cpuworker and dnsworker processes, so they get up-to-date
      * configuration options. */
     cpuworkers_rotate();
-    dnsworkers_rotate();
+    dns_reset();
 #if 0
     /* Write out a fresh descriptor, but leave old one on failure. */
     router_rebuild_descriptor(1);

Modified: tor/trunk/src/or/or.h
===================================================================
--- tor/trunk/src/or/or.h	2006-08-28 03:15:50 UTC (rev 8254)
+++ tor/trunk/src/or/or.h	2006-08-28 03:15:55 UTC (rev 8255)
@@ -710,7 +710,6 @@
                        * circuit? */
   int deliver_window; /**< How many more relay cells can end at me? */
 
-
   /** Nickname of planned exit node -- used with .exit support. */
   char *chosen_exit_name;
 
@@ -2133,7 +2132,7 @@
 int connection_dns_finished_flushing(connection_t *conn);
 int connection_dns_reached_eof(connection_t *conn);
 int connection_dns_process_inbuf(connection_t *conn);
-void dnsworkers_rotate(void);
+void dns_reset(void);
 void connection_dns_remove(edge_connection_t *conn);
 void assert_connection_edge_not_dns_pending(edge_connection_t *conn);
 void assert_all_pending_dns_resolves_ok(void);



More information about the tor-commits mailing list