From cc685733a58293f2a186d98e20842ada10419076 Mon Sep 17 00:00:00 2001
From: Vladislav Bolkhovitin <vst@vlnb.net>
Date: Wed, 14 May 2008 17:20:20 +0000
Subject: [PATCH] Interface versioning between iSCSI-SCST kernel and user space
 parts, iscsi_u.h renamed to iscsi_scst.h. Property svn:ignore adjusted
 accordingly. Docs updated.

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@371 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 iscsi-scst/Makefile                           | 19 +++++++----
 iscsi-scst/README                             |  6 ++++
 .../include/{iscsi_u.h => iscsi_scst.h}       | 34 ++++++++++---------
 iscsi-scst/include/iscsi_scst_ver.h           | 16 +++++++++
 iscsi-scst/kernel/config.c                    | 31 ++++++++++++++++-
 iscsi-scst/kernel/event.c                     |  2 +-
 iscsi-scst/kernel/iscsi.h                     |  2 +-
 iscsi-scst/usr/ctldev.c                       | 23 +++++++++----
 iscsi-scst/usr/iscsi_scstd.c                  |  4 +--
 iscsi-scst/usr/iscsid.h                       |  2 +-
 10 files changed, 102 insertions(+), 37 deletions(-)
 rename iscsi-scst/include/{iscsi_u.h => iscsi_scst.h} (74%)
 create mode 100644 iscsi-scst/include/iscsi_scst_ver.h

diff --git a/iscsi-scst/Makefile b/iscsi-scst/Makefile
index 9f4797595..245ae74d9 100644
--- a/iscsi-scst/Makefile
+++ b/iscsi-scst/Makefile
@@ -1,11 +1,9 @@
 #
-# Makefile for the Linux kernel device drivers.
+# Makefile for iSCSI-SCST
 #
 # Note! Dependencies are done automagically by 'make dep', which also
 # removes any old dependencies. DON'T put your own dependencies here
 # unless it's something special (not a .c file).
-#
-# Note 2! The CFLAGS definitions are now in the main makefile.
 
 SCST_DIR := $(shell pwd)/../scst/src
 SUBDIRS := $(shell pwd)
@@ -21,7 +19,7 @@ else
   KDIR ?= /lib/modules/$(KVER)/build
 endif
 
-all: progs mods
+all: include/iscsi_scst_itf_ver.h progs mods
 
 mods: Modules.symvers Module.symvers
 	$(MAKE) -C $(KDIR) SUBDIRS=$(shell pwd)/kernel modules
@@ -29,9 +27,15 @@ mods: Modules.symvers Module.symvers
 progs:
 	$(MAKE) -C usr
 
-install: all kernel/iscsi-scst.ko usr/iscsi-scstd usr/iscsi-scst-adm
+include/iscsi_scst_itf_ver.h: include/iscsi_scst.h
+	echo "/* Autogenerated, don't edit */" >include/iscsi_scst_itf_ver.h
+	echo "" >>include/iscsi_scst_itf_ver.h
+	echo -n "#define ISCSI_SCST_INTERFACE_VERSION " >>include/iscsi_scst_itf_ver.h
+	echo "\"`sha1sum include/iscsi_scst.h|awk '{printf $$1}'`\"" >>include/iscsi_scst_itf_ver.h
+
+install: all
 	@install -vD usr/iscsi-scstd $(DISTDIR)/usr/local/sbin/iscsi-scstd
-	@install -vD usr/iscsi-scst-adm $(DISTDIR)/usr/local/sbin/iscsi-scst-adm
+	-@install -vD usr/iscsi-scst-adm $(DISTDIR)/usr/local/sbin/iscsi-scst-adm
 	if [ -f /etc/debian_version ]; then \
 		install -vD -m 755 etc/initd/initd.debian $(DISTDIR)/etc/init.d/iscsi-scst; \
 	elif [ -f /etc/redhat-release ]; then \
@@ -70,7 +74,8 @@ clean:
 	$(MAKE) -C usr clean
 	$(MAKE) -C $(KDIR) SUBDIRS=$(shell pwd)/kernel clean
 	rm -f kernel/Modules.symvers kernel/Module.symvers \
-		kernel/Module.markers kernel/modules.order
+		kernel/Module.markers kernel/modules.order \
+		include/iscsi_scst_itf_ver.h
 
 extraclean: clean
 
diff --git a/iscsi-scst/README b/iscsi-scst/README
index 07742bc32..16bd66433 100644
--- a/iscsi-scst/README
+++ b/iscsi-scst/README
@@ -32,6 +32,12 @@ Installation
 Basically as in README-IET, where file names are changed as specified
 above.
 
+If during compilation you see message like "*** No rule to make target
+`xxx.h', needed by `yyy.o'.  Stop.", then your autogenerated
+dependencies don't match your compiler configuration anymore. You should
+run "make extraclean" to remove them. On the next compilation they will
+be regenerated.
+
 If you experience problems during kernel module load or running, check
 your system and/or kernel logs (or run dmesg command for the few most
 recent kernel messages).
diff --git a/iscsi-scst/include/iscsi_u.h b/iscsi-scst/include/iscsi_scst.h
similarity index 74%
rename from iscsi-scst/include/iscsi_u.h
rename to iscsi-scst/include/iscsi_scst.h
index 1badfbac8..4a1c9a7a9 100644
--- a/iscsi-scst/include/iscsi_u.h
+++ b/iscsi-scst/include/iscsi_scst.h
@@ -13,21 +13,22 @@
  *  GNU General Public License for more details.
  */
 
-#ifndef _ISCSI_U_H
-#define _ISCSI_U_H
+#ifndef _ISCSI_SCST_U_H
+#define _ISCSI_SCST_U_H
 
 #ifndef __KERNEL__
 #include <sys/uio.h>
 #endif
 
-#define ISCSI_VERSION_STRING	"0.9.6/0.4.15r148"
+#include "iscsi_scst_ver.h"
+#include "iscsi_scst_itf_ver.h"
 
 /* The maximum length of 223 bytes in the RFC. */
-#define ISCSI_NAME_LEN	256
+#define ISCSI_NAME_LEN		256
 
 #define ISCSI_LISTEN_PORT	3260
 
-#define SCSI_ID_LEN	24
+#define SCSI_ID_LEN		24
 
 #ifndef aligned_u64
 #define aligned_u64 uint64_t __attribute__((aligned(8)))
@@ -47,7 +48,7 @@ struct session_info {
 	u32 exp_cmd_sn;
 };
 
-#define DIGEST_ALL	(DIGEST_NONE | DIGEST_CRC32C)
+#define DIGEST_ALL		(DIGEST_NONE | DIGEST_CRC32C)
 #define DIGEST_NONE		(1 << 0)
 #define DIGEST_CRC32C           (1 << 1)
 
@@ -126,16 +127,17 @@ struct iscsi_event {
 
 #define NETLINK_ISCSI_SCST	25
 
-#define ADD_TARGET _IOW('i', 0, struct target_info)
-#define DEL_TARGET _IOW('i', 1, struct target_info)
-#define ADD_SESSION _IOW('i', 2, struct session_info)
-#define DEL_SESSION _IOW('i', 3, struct session_info)
-#define GET_SESSION_INFO _IOWR('i', 4, struct session_info)
-#define ADD_CONN _IOW('i', 5, struct conn_info)
-#define DEL_CONN _IOW('i', 6, struct conn_info)
-#define GET_CONN_INFO _IOWR('i', 7, struct conn_info)
-#define ISCSI_PARAM_SET _IOW('i', 8, struct iscsi_param_info)
-#define ISCSI_PARAM_GET _IOWR('i', 9, struct iscsi_param_info)
+#define REGISTER_USERD		_IOW('s', 0, const char*)
+#define ADD_TARGET		_IOW('s', 1, struct target_info)
+#define DEL_TARGET		_IOW('s', 2, struct target_info)
+#define ADD_SESSION		_IOW('s', 3, struct session_info)
+#define DEL_SESSION		_IOW('s', 4, struct session_info)
+#define GET_SESSION_INFO	_IOWR('s', 5, struct session_info)
+#define ADD_CONN		_IOW('s', 6, struct conn_info)
+#define DEL_CONN		_IOW('s', 7, struct conn_info)
+#define GET_CONN_INFO		_IOWR('s', 8, struct conn_info)
+#define ISCSI_PARAM_SET		_IOW('s', 9, struct iscsi_param_info)
+#define ISCSI_PARAM_GET		_IOWR('s', 10, struct iscsi_param_info)
 
 static inline int iscsi_is_key_declarative(int key)
 {
diff --git a/iscsi-scst/include/iscsi_scst_ver.h b/iscsi-scst/include/iscsi_scst_ver.h
new file mode 100644
index 000000000..e1599925d
--- /dev/null
+++ b/iscsi-scst/include/iscsi_scst_ver.h
@@ -0,0 +1,16 @@
+/*
+ *  Copyright (C) 2007 Vladislav Bolkhovitin
+ *  Copyright (C) 2007 CMS Distribution Limited
+ * 
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation, version 2
+ *  of the License.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *  GNU General Public License for more details.
+ */
+
+#define ISCSI_VERSION_STRING	"0.9.6/0.4.15r148"
diff --git a/iscsi-scst/kernel/config.c b/iscsi-scst/kernel/config.c
index 8fb0a6220..29001383a 100644
--- a/iscsi-scst/kernel/config.c
+++ b/iscsi-scst/kernel/config.c
@@ -369,12 +369,40 @@ static int add_target(unsigned long ptr)
 	return err;
 }
 
+static int iscsi_check_version(unsigned long arg)
+{
+	char ver[sizeof(ISCSI_SCST_INTERFACE_VERSION)+1];
+	int res;
+
+	res = copy_from_user(ver, (void*)arg, sizeof(ver));
+	if (res < 0) {
+		PRINT_ERROR("%s", "Unable to get version string");
+		goto out;
+	}
+	ver[sizeof(ver)-1] = '\0';
+
+	if (strcmp(ver, ISCSI_SCST_INTERFACE_VERSION) != 0) {
+		PRINT_ERROR("Incorrect version of user space %s (needed %s)",
+			ver, ISCSI_SCST_INTERFACE_VERSION);
+		res = -EINVAL;
+		goto out;
+	}
+
+out:
+	return res;
+}
+
 static long ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct iscsi_target *target = NULL;
 	long err;
 	u32 id;
 
+	if (cmd == REGISTER_USERD) {
+		err = iscsi_check_version(arg);
+		goto out;
+	}
+
 	if ((err = get_user(id, (u32 *) arg)) != 0)
 		goto out;
 
@@ -441,10 +469,11 @@ static long ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case GET_CONN_INFO:
 		err = get_conn_info(target, arg);
 		break;
-	
+
 	default:
 		PRINT_ERROR("invalid ioctl cmd %x", cmd);
 		err = -EINVAL;
+		break;
 	}
 
 	mutex_unlock(&target->target_mutex);
diff --git a/iscsi-scst/kernel/event.c b/iscsi-scst/kernel/event.c
index 5e2cb2037..480bc9c4d 100644
--- a/iscsi-scst/kernel/event.c
+++ b/iscsi-scst/kernel/event.c
@@ -18,7 +18,7 @@
  */
 
 #include <net/tcp.h>
-#include "iscsi_u.h"
+#include "iscsi_scst.h"
 #include "iscsi.h"
 
 static struct sock *nl;
diff --git a/iscsi-scst/kernel/iscsi.h b/iscsi-scst/kernel/iscsi.h
index e0368e114..cb3c039d1 100644
--- a/iscsi-scst/kernel/iscsi.h
+++ b/iscsi-scst/kernel/iscsi.h
@@ -26,7 +26,7 @@
 #include <scst.h>
 
 #include "iscsi_hdr.h"
-#include "iscsi_u.h"
+#include "iscsi_scst.h"
 
 #include "iscsi_dbg.h"
 
diff --git a/iscsi-scst/usr/ctldev.c b/iscsi-scst/usr/ctldev.c
index 41929d644..34417ac43 100644
--- a/iscsi-scst/usr/ctldev.c
+++ b/iscsi-scst/usr/ctldev.c
@@ -40,11 +40,12 @@ static int ctrdev_open(void)
 	char devname[256];
 	char buf[256];
 	int devn;
-	int ctlfd;
+	int ctlfd = -1;
+	int err;
 
 	if (!(f = fopen("/proc/devices", "r"))) {
 		perror("Cannot open control path to the driver\n");
-		return -1;
+		goto out;
 	}
 
 	devn = 0;
@@ -63,24 +64,32 @@ static int ctrdev_open(void)
 
 	fclose(f);
 	if (!devn) {
-		printf
-		    ("cannot find iscsictl in /proc/devices - "
+		printf("cannot find iscsictl in /proc/devices - "
 		     "make sure the module is loaded\n");
-		return -1;
+		goto out;
 	}
 
 	unlink(CTL_DEVICE);
 	if (mknod(CTL_DEVICE, (S_IFCHR | 0600), (devn << 8))) {
 		printf("cannot create %s %d\n", CTL_DEVICE, errno);
-		return -1;
+		goto out;
 	}
 
 	ctlfd = open(CTL_DEVICE, O_RDWR);
 	if (ctlfd < 0) {
 		printf("cannot open %s %d\n", CTL_DEVICE, errno);
-		return -1;
+		goto out;
 	}
 
+	err = ioctl(ctlfd, REGISTER_USERD, ISCSI_SCST_INTERFACE_VERSION);
+	if (err < 0) {
+		log_error("Unable to register: %s\n", strerror(errno));
+		close(ctlfd);
+		ctlfd = -1;
+		goto out;
+	}
+
+out:
 	return ctlfd;
 }
 
diff --git a/iscsi-scst/usr/iscsi_scstd.c b/iscsi-scst/usr/iscsi_scstd.c
index 2ff27476b..66c07a29a 100644
--- a/iscsi-scst/usr/iscsi_scstd.c
+++ b/iscsi-scst/usr/iscsi_scstd.c
@@ -573,10 +573,8 @@ int main(int argc, char **argv)
 		exit(-1);
 	};
 
-	if ((ctrl_fd = ki->ctldev_open()) < 0) {
-		perror("ctldev fd\n");
+	if ((ctrl_fd = ki->ctldev_open()) < 0)
 		exit(-1);
-	}
 
 	if ((ipc_fd = iscsi_adm_request_listen()) < 0) {
 		perror("ipc fd\n");
diff --git a/iscsi-scst/usr/iscsid.h b/iscsi-scst/usr/iscsid.h
index 9ecaa2bcc..0aaffc582 100644
--- a/iscsi-scst/usr/iscsid.h
+++ b/iscsi-scst/usr/iscsid.h
@@ -22,7 +22,7 @@
 
 #include "types.h"
 #include "iscsi_hdr.h"
-#include "iscsi_u.h"
+#include "iscsi_scst.h"
 #include "param.h"
 #include "config.h"
 #include "misc.h"