From bd6bb4939714bf8bf9cf180ffd4ff55cd876d643 Mon Sep 17 00:00:00 2001
From: Richard Scheffenegger <rscheff@FreeBSD.org>
Date: Fri, 25 Feb 2022 10:33:59 +0100
Subject: iscsi: per-session timeouts and rapid teardown of session on
 reconnect

Add per-Session configurable ping (SCSI NOP) and login timeouts.

Remove the torn down, old iSCSI session quickly, when performing a reconnect.

Reviewed By: trasz
Sponsored by:        NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D34198
---
 usr.sbin/iscsid/iscsid.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

(limited to 'usr.sbin/iscsid')

diff --git a/usr.sbin/iscsid/iscsid.c b/usr.sbin/iscsid/iscsid.c
index 2689c4a2b455..ebfcfa34dd6d 100644
--- a/usr.sbin/iscsid/iscsid.c
+++ b/usr.sbin/iscsid/iscsid.c
@@ -38,9 +38,11 @@ __FBSDID("$FreeBSD$");
 #include <sys/param.h>
 #include <sys/linker.h>
 #include <sys/socket.h>
+#include <sys/sysctl.h>
 #include <sys/capsicum.h>
 #include <sys/wait.h>
 #include <netinet/in.h>
+#include <netinet/tcp.h>
 #include <assert.h>
 #include <capsicum_helpers.h>
 #include <errno.h>
@@ -383,6 +385,32 @@ connection_new(int iscsi_fd, const struct iscsi_daemon_request *request)
 				    from_addr);
 		}
 	}
+	/*
+	 * Reduce TCP SYN_SENT timeout while
+	 * no connectivity exists, to allow
+	 * rapid reuse of the available slots.
+	 */
+	int keepinit = 0;
+	if (conn->conn_conf.isc_login_timeout > 0) {
+		keepinit = conn->conn_conf.isc_login_timeout;
+		log_debugx("session specific LoginTimeout at %d sec",
+			keepinit);
+	}
+	if (conn->conn_conf.isc_login_timeout == -1) {
+		char value[8];
+		size_t size = sizeof(value);
+		sysctlbyname("kern.iscsi.login_timeout", &value, &size,
+			NULL, 0);
+		keepinit = strtol(value, NULL, 10);
+		log_debugx("global login_timeout at %d sec", keepinit);
+	}
+	if (keepinit > 0) {
+		if (setsockopt(conn->conn.conn_socket,
+		    IPPROTO_TCP, TCP_KEEPINIT,
+		    &keepinit, sizeof(keepinit)) == -1)
+			log_warnx("setsockopt(TCP_KEEPINIT) "
+			    "failed for %s", to_addr);
+	}
 	if (from_ai != NULL) {
 		error = bind(conn->conn.conn_socket, from_ai->ai_addr,
 		    from_ai->ai_addrlen);
-- 
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