This patch adds a method to manage the resource limit which was

introduced by the fix for ISC-Bugs #41845. This patch was developed

in-house. ISC did not express any interest in incorporating this patch

into their code since they consider the limit to be a mitigating

solution.

--- old/includes/omapip/omapip.h	Tue May 24 17:01:08 2016

+++ new/includes/omapip/omapip.h	Tue May 24 17:01:08 2016

@@ -468,6 +468,9 @@

 extern omapi_object_type_t *omapi_object_types;

+#if defined (sun)

+void omapi_set_max_fd_value (void);

+#endif

 void omapi_type_relinquish (void);

 isc_result_t omapi_init (void);

 isc_result_t omapi_object_type_register (omapi_object_type_t **,

--- old/omapip/listener.c	Tue May 24 17:01:08 2016

+++ new/omapip/listener.c	Tue May 24 17:01:08 2016

@@ -41,6 +41,10 @@

 trace_type_t *trace_listener_accept;

 #endif

+#if defined (sun)

+static int conn_limit = MAX_FD_VALUE; /* max number of open sockets allowed */

+#endif

+

 OMAPI_OBJECT_ALLOC (omapi_listener,

 		    omapi_listener_object_t, omapi_type_listener)

@@ -210,6 +214,35 @@

 	return l -> socket;

 }

+#if defined (sun)

+/* If OMAPI_CONN_LIMIT environment variable is set, obtain value. */

+const char *fname = "omapi_set_max_fd_value";

+void omapi_set_max_fd_value (void)

+{

+	const char *env;

+	char *end = NULL;

+	int envval = conn_limit;

+

+	env = getenv("OMAPI_CONN_LIMIT");

+	if (env != NULL) {

+		errno = 0;

+		envval = (int)strtol(env, &end, 10);

+		if (errno != 0 || env == end || *end != '\0' || envval < 0) {

+			(void) log_error("%s: \"%s\" is not a valid connection "

+					"limit value\n", fname, env);

+			errno = 0;

+		} else {

+			conn_limit = envval;

+		}

+	}

+	(void) log_debug("%s: conn_limit = %d%s\n", fname, conn_limit,

+			(conn_limit == MAX_FD_VALUE) ? " (default)" :

+			(conn_limit == 0) ? " (unlimited)" : "");

+

+	return;

+}

+#endif

+

 /* Reader callback for a listener object.   Accept an incoming connection. */

 isc_result_t omapi_accept (omapi_object_t *h)

 {

@@ -234,7 +267,13 @@

 		return ISC_R_UNEXPECTED;

 	}

+#if !defined (sun)

 	if ((MAX_FD_VALUE != 0) && (socket > MAX_FD_VALUE)) {

+#else

+	if ((conn_limit != 0) && (socket > conn_limit)) {

+		(void) log_debug("omapi_accept: No more available "

+		    "sockets - closing latest.\n");

+#endif

 		close(socket);

 		return (ISC_R_NORESOURCES);

 	}

--- old/server/dhcpd.c	Tue May 24 17:01:08 2016

+++ new/server/dhcpd.c	Tue May 24 17:01:08 2016

@@ -363,6 +363,10 @@

 		path_dhcpd_conf = s;

 	}

+#if defined (sun)

+	omapi_set_max_fd_value ();

+#endif

+

 #ifdef DHCPv6

         if (local_family == AF_INET6) {

                 /* DHCPv6: override DHCPv4 lease and pid filenames */