From b6782dd7c8a733b0d7ffcb148de3f350355f3ff1 Mon Sep 17 00:00:00 2001
From: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Date: Wed, 13 Apr 2011 21:35:51 +1000
Subject: [PATCH] TCP KEEPALIVE support

Add tcp keeplaive support on platforms that support these socket options.
Set default to fail the socket after 120 seconds
---
 configure.ac    | 10 ++++++++++
 include/iscsi.h |  6 +++++-
 lib/socket.c    | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 8eff907..1108fdd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -64,6 +64,16 @@ if test x"$libiscsi_cv_HAVE_SOCK_SIN_LEN" = x"yes"; then
     AC_DEFINE(HAVE_SOCK_SIN_LEN,1,[Whether the sockaddr_in struct has a sin_len property])
 fi
 
+AC_CACHE_CHECK([for tcp keepalive],libiscsi_cv_HAVE_TCP_KEEPALIVE,[
+AC_TRY_COMPILE([#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>],
+[int foo = TCP_KEEPCNT + TCP_KEEPIDLE + TCP_KEEPINTVL],
+libiscsi_cv_HAVE_TCP_KEEPALIVE=yes,libiscsi_cv_HAVE_TCP_KEEPALIVE=no)])
+if test x"$libiscsi_cv_HAVE_TCP_KEEPALIVE" = x"yes"; then
+    AC_DEFINE(HAVE_TCP_KEEPALIVE,1,[Whether we have support for tcp keepalive socket options])
+fi
+
 AC_MSG_CHECKING(whether libpopt is available)
 ac_save_CFLAGS="$CFLAGS"
 ac_save_LIBS="$LIBS"
diff --git a/include/iscsi.h b/include/iscsi.h
index afd9acf..c86dbe3 100644
--- a/include/iscsi.h
+++ b/include/iscsi.h
@@ -54,7 +54,11 @@ int iscsi_service(struct iscsi_context *iscsi, int revents);
  */
 int iscsi_queue_length(struct iscsi_context *iscsi);
 
-
+/*
+ * To set tcp keepalive for the session
+ * ONLY available on platforms with tcp keepalive socket options
+ */
+int iscsi_set_tcp_keepalive(struct iscsi_context *iscsi, int idle, int count, int interval);
 
 
 
diff --git a/lib/socket.c b/lib/socket.c
index b54d882..30d6ecf 100644
--- a/lib/socket.c
+++ b/lib/socket.c
@@ -23,7 +23,9 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <sys/socket.h>
 #include <netinet/in.h>
+#include <netinet/tcp.h>
 #include <poll.h>
 #include <sys/ioctl.h>
 #include <arpa/inet.h>
@@ -411,6 +413,9 @@ iscsi_service(struct iscsi_context *iscsi, int revents)
 			return -1;
 		}
 
+#ifdef HAVE_TCP_KEEPALIVE
+		iscsi_set_tcp_keepalive(iscsi, 30, 3, 30);
+#endif
 		iscsi->is_connected = 1;
 		iscsi->socket_status_cb(iscsi, SCSI_STATUS_GOOD, NULL,
 					iscsi->connect_data);
@@ -476,3 +481,37 @@ iscsi_free_iscsi_inqueue(struct iscsi_in_pdu *inqueue)
 	      inqueue = next;
 	}
 }
+
+#ifdef HAVE_TCP_KEEPALIVE
+int iscsi_set_tcp_keepalive(struct iscsi_context *iscsi, int idle, int count, int interval)
+{
+	int value;
+
+	value =1;
+	if (setsockopt(iscsi->fd, SOL_SOCKET, SO_KEEPALIVE, &value, sizeof(value)) != 0) {
+		iscsi_set_error(iscsi, "TCP: Failed to set socket option SO_KEEPALIVE. Error %s(%d)", strerror(errno), errno);
+		return -1;
+	}
+
+	value = count;
+	if (setsockopt(iscsi->fd, SOL_TCP, TCP_KEEPCNT, &value, sizeof(value)) != 0) {
+		iscsi_set_error(iscsi, "TCP: Failed to set tcp keepalive count. Error %s(%d)", strerror(errno), errno);
+		return -1;
+	}
+
+	value = interval;
+	if (setsockopt(iscsi->fd, SOL_TCP, TCP_KEEPINTVL, &value, sizeof(value)) != 0) {
+		iscsi_set_error(iscsi, "TCP: Failed to set tcp keepalive interval. Error %s(%d)", strerror(errno), errno);
+		return -1;
+	}
+
+	value = idle;
+	if (setsockopt(iscsi->fd, SOL_TCP, TCP_KEEPIDLE, &value, sizeof(value)) != 0) {
+		iscsi_set_error(iscsi, "TCP: Failed to set tcp keepalive idle. Error %s(%d)", strerror(errno), errno);
+		return -1;
+	}
+
+	return 0;
+}
+
+#endif