[Bug 1178] Use prior FORCE_DNSRETRY behavior as needed at runtime

bk: 4a04167bFWfrklNf0eFXgvUT6oZSew

diff --git a/ChangeLog b/ChangeLog
index 6fdc947de5d04168f33aeb4d852801db608cbc8b..66c266efa10e3347cf68dde583f3f50b002a3478 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+---
+
+* [Bug 1178] Use prior FORCE_DNSRETRY behavior as needed at runtime
+
 ---
 (4.2.4p7-RC5) 2009/05/02 Released by Harlan Stenn <stenn@ntp.org>
 

diff --git a/ntpd/ntp_intres.c b/ntpd/ntp_intres.c
index 2a4b51fef7c92ad18d35f8c2aad2c6cd7fd85192..ffa7e14d1bcd67892ee335b935ab6c9fb5f72e7b 100644 (file)
--- a/ntpd/ntp_intres.c
+++ b/ntpd/ntp_intres.c
@@ -15,11 +15,6 @@
  * might go about autoconfiguring an NTP distribution network.
  *
  */
- /*
- * For special situations define the FORCE_DNSRETRY Macro
- * to force retries even if it fails the lookup.
- * Use with extreme caution since it will then retry forever.
- */
 
 #ifdef HAVE_CONFIG_H
 # include <config.h>
@@ -463,8 +458,10 @@ findhostaddr(
        struct conf_entry *entry
        )
 {
+       static int eai_again_seen = 0;
        struct addrinfo *addr;
        struct addrinfo hints;
+       int again;
        int error;
 
        checkparent();          /* make sure our guy is still running */
@@ -475,17 +472,14 @@ findhostaddr(
                return 1;
        }
 
-        if (entry->ce_name == NULL && SOCKNUL(&entry->peer_store)) {
+       if (entry->ce_name == NULL && SOCKNUL(&entry->peer_store)) {
                msyslog(LOG_ERR, "findhostaddr: both ce_name and ce_peeraddr are undefined!");
                return 0;
        }
 
        if (entry->ce_name) {
-#ifdef DEBUG
-               if (debug > 2)
-                       msyslog(LOG_INFO, "findhostaddr: Resolving <%s>",
-                               entry->ce_name);
-#endif /* DEBUG */
+               DPRINTF(2, ("findhostaddr: Resolving <%s>\n",
+                       entry->ce_name);
 
                memset(&hints, 0, sizeof(hints));
                hints.ai_family = AF_UNSPEC;
@@ -508,68 +502,72 @@ findhostaddr(
                                entry->ce_config.v6_flag = 1;
                        }
                }
-               else if (error == EAI_NONAME)
-               {
-                       msyslog(LOG_ERR, "host name not found: %s", entry->ce_name);
-               }
        } else {
-#ifdef DEBUG
-               if (debug > 2)
-                       msyslog(LOG_INFO, "findhostaddr: Resolving %s>",
-                               stoa(&entry->peer_store));
-#endif
+               DPRINTF(2, ("findhostaddr: Resolving <%s>\n",
+                       stoa(&entry->peer_store)));
+
                entry->ce_name = emalloc(MAXHOSTNAMELEN);
                error = getnameinfo((const struct sockaddr *)&entry->peer_store,
                                   SOCKLEN(&entry->peer_store),
                                   (char *)&entry->ce_name, MAXHOSTNAMELEN,
                                   NULL, 0, 0);
        }
-#ifdef DEBUG
-       if (debug > 2)
-               printf("intres: got error status of: %d\n", error);
-#endif
 
-       /*
-        * If the resolver failed, see if the failure is
-        * temporary. If so, return success.
-        */
-       if (error != 0) {
-               switch (error)
-               {
+       if (0 == error) {
+
+               /* again is our return value, for success it is 1 */
+               again = 1;
+
+               DPRINTF(2, ("findhostaddr: %s resolved.\n", 
+                       (entry->ce_name) ? "name" : "address"));
+       } else {
+               /*
+                * If the resolver failed, see if the failure is
+                * temporary. If so, return success.
+                */
+               again = 0;
+
+               switch (error) {
+
+               case EAI_FAIL:
+                       again = 1;
+                       break
+
                case EAI_AGAIN:
-                       return (1);
+                       again = 1;
+                       eai_again_seen = 1;
+                       break;
+
                case EAI_NONAME:
-#ifndef FORCE_DNSRETRY
-                       return (0);
-#else
-                       return (1);
-#endif
 #if defined(EAI_NODATA) && (EAI_NODATA != EAI_NONAME)
                case EAI_NODATA:
 #endif
-               case EAI_FAIL:
+                       msyslog(LOG_ERR, "host name not found %s%s: %s",
+                               (EAI_NONAME == error) ? "EAI_NONAME" : "EAI_NODATA",
+                               (eai_again_seen) ? " (permanent)" : "",
+                               entry->ce_name);
+                       again = !eai_again_seen;
+                       break;
+
 #ifdef EAI_SYSTEM
-               case EAI_SYSTEM:
-                       return (1);
+               case EAI_SYSTEM
+                       /* 
+                        * EAI_SYSTEM means the real error is in errno.  We should be more
+                        * discriminating about which errno values require retrying, but
+                        * this matches existing behavior.
+                        */
+                       again = 1;
+                       DPRINTF(1, ("intres: EAI_SYSTEM errno %d (%s) means try again, right?\n"
+                               errno, strerror(errno)));
+                       break;
 #endif
-               default:
-                       return (0);
                }
-       }
 
-       if (entry->ce_name) {
-#ifdef DEBUG
-               if (debug > 2)
-                       msyslog(LOG_INFO, "findhostaddr: name resolved.");
-#endif
-
-#ifdef DEBUG
-               if (debug > 2)
-                       msyslog(LOG_INFO, "findhostaddr: address resolved.");
-#endif
+               /* do this here to avoid perturbing errno earlier */
+               DPRINTF(2, ("intres: got error status of: %d\n", error));
        }
-                  
-       return (1);
+
+       return again;
 }