commit ba675ed25a26fd425ffd19b02cf18babf4291b4f

Author: Mark Wielaard <mark@klomp.org>

Date:   Thu May 5 23:59:57 2022 +0200

    debuginfod: Try without MHD_USE_DUAL_STACK if MHD_start_daemon fails

    On a systems that have ipv6 disabled debuginfod doesn't start up

    anymore because libhttpd MHD_USE_DUAL_STACK only works if it can

    open an ipv6 socket. If MHD_start_daemon with MHD_USE_DUAL_STACK

    fails try again without that flag set.

    https://sourceware.org/bugzilla/show_bug.cgi?id=29122

    Signed-off-by: Mark Wielaard <mark@klomp.org>

diff --git a/debuginfod/debuginfod.cxx b/debuginfod/debuginfod.cxx

index 4aaf41c0..c02540f1 100644

--- a/debuginfod/debuginfod.cxx

+++ b/debuginfod/debuginfod.cxx

@@ -3899,40 +3899,67 @@ main (int argc, char *argv[])

         }

     }

-  // Start httpd server threads.  Use a single dual-homed pool.

-  MHD_Daemon *d46 = MHD_start_daemon ((connection_pool ? 0 : MHD_USE_THREAD_PER_CONNECTION)

+  unsigned int mhd_flags = ((connection_pool

+			     ? 0 : MHD_USE_THREAD_PER_CONNECTION)

 #if MHD_VERSION >= 0x00095300

-                                     | MHD_USE_INTERNAL_POLLING_THREAD

+			    | MHD_USE_INTERNAL_POLLING_THREAD

 #else

-                                     | MHD_USE_SELECT_INTERNALLY

+			    | MHD_USE_SELECT_INTERNALLY

 #endif

+			    | MHD_USE_DUAL_STACK

 #ifdef MHD_USE_EPOLL

-                                     | MHD_USE_EPOLL

+			    | MHD_USE_EPOLL

 #endif

-                                     | MHD_USE_DUAL_STACK

 #if MHD_VERSION >= 0x00095200

-                                     | MHD_USE_ITC

+			    | MHD_USE_ITC

 #endif

-                                     | MHD_USE_DEBUG, /* report errors to stderr */

-                                     http_port,

-                                     NULL, NULL, /* default accept policy */

-                                     handler_cb, NULL, /* handler callback */

-                                     MHD_OPTION_EXTERNAL_LOGGER, error_cb, NULL,

-                                     (connection_pool ? MHD_OPTION_THREAD_POOL_SIZE : MHD_OPTION_END),

-                                     (connection_pool ? (int)connection_pool : MHD_OPTION_END),

-                                     MHD_OPTION_END);

+			    | MHD_USE_DEBUG); /* report errors to stderr */

+  // Start httpd server threads.  Use a single dual-homed pool.

+  MHD_Daemon *d46 = MHD_start_daemon (mhd_flags, http_port,

+				      NULL, NULL, /* default accept policy */

+				      handler_cb, NULL, /* handler callback */

+				      MHD_OPTION_EXTERNAL_LOGGER,

+				      error_cb, NULL,

+				      (connection_pool

+				       ? MHD_OPTION_THREAD_POOL_SIZE

+				       : MHD_OPTION_END),

+				      (connection_pool

+				       ? (int)connection_pool

+				       : MHD_OPTION_END),

+				      MHD_OPTION_END);

+

+  MHD_Daemon *d4 = NULL;

   if (d46 == NULL)

     {

-      sqlite3 *database = db;

-      sqlite3 *databaseq = dbq;

-      db = dbq = 0; // for signal_handler not to freak

-      sqlite3_close (databaseq);

-      sqlite3_close (database);

-      error (EXIT_FAILURE, 0, "cannot start http server at port %d", http_port);

-    }

+      // Cannot use dual_stack, use ipv4 only

+      mhd_flags &= ~(MHD_USE_DUAL_STACK);

+      d4 = MHD_start_daemon (mhd_flags, http_port,

+			     NULL, NULL, /* default accept policy */

+			     handler_cb, NULL, /* handler callback */

+			     MHD_OPTION_EXTERNAL_LOGGER,

+			     error_cb, NULL,

+			     (connection_pool

+			      ? MHD_OPTION_THREAD_POOL_SIZE

+			      : MHD_OPTION_END),

+			     (connection_pool

+			      ? (int)connection_pool

+			      : MHD_OPTION_END),

+			     MHD_OPTION_END);

+      if (d4 == NULL)

+	{

+	  sqlite3 *database = db;

+	  sqlite3 *databaseq = dbq;

+	  db = dbq = 0; // for signal_handler not to freak

+	  sqlite3_close (databaseq);

+	  sqlite3_close (database);

+	  error (EXIT_FAILURE, 0, "cannot start http server at port %d",

+		 http_port);

+	}

-  obatched(clog) << "started http server on IPv4 IPv6 "

+    }

+  obatched(clog) << "started http server on"

+                 << (d4 != NULL ? " IPv4 " : " IPv4 IPv6 ")

                  << "port=" << http_port << endl;

   // add maxigroom sql if -G given

@@ -4053,6 +4080,7 @@ main (int argc, char *argv[])

   /* Stop all the web service threads. */

   if (d46) MHD_stop_daemon (d46);

+  if (d4) MHD_stop_daemon (d4);

   if (! passive_p)

     {