Add utility to get/set the software write protect flag

Makefile.am

@@ -9,11 +9,11 @@ LDADD = lib/libiscsi.la
 XSLTPROC = /usr/bin/xsltproc
 
 # Manpages
-man1_MANS = doc/iscsi-inq.1 doc/iscsi-ls.1
+man1_MANS = doc/iscsi-inq.1 doc/iscsi-ls.1 doc/iscsi-swp.1
 
 EXTRA_DIST = autogen.sh COPYING LICENCE-GPL-2.txt LICENCE-LGPL-2.1.txt \
 	     packaging/RPM/libiscsi.spec.in packaging/RPM/makerpms.sh \
-	     doc/iscsi-inq.1.xml doc/iscsi-ls.1.xml
+	     doc/iscsi-inq.1.xml doc/iscsi-ls.1.xml doc/iscsi-swp.1.xml
 
 # Simplify conditions below by declaring variables as empty
 
@@ -50,9 +50,11 @@ lib_libiscsi_la_LDFLAGS = \
 
 # libiscsi utilities
 
-bin_PROGRAMS += bin/iscsi-inq bin/iscsi-ls bin/iscsi-readcapacity16
+bin_PROGRAMS += bin/iscsi-inq bin/iscsi-ls bin/iscsi-readcapacity16 \
+	bin/iscsi-swp
 bin_iscsi_inq_SOURCES = src/iscsi-inq.c
 bin_iscsi_ls_SOURCES = src/iscsi-ls.c
+bin_iscsi_swp_SOURCES = src/iscsi-swp.c
 bin_iscsi_readcapacity16_SOURCES = src/iscsi-readcapacity16.c
 
 # Other examples
@@ -387,3 +389,7 @@ doc/iscsi-ls.1: doc/iscsi-ls.1.xml
 
 doc/iscsi-inq.1: doc/iscsi-inq.1.xml
 	-test -z "$(XSLTPROC)" || $(XSLTPROC) -o $@ http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl $<
+
+doc/iscsi-swp.1: doc/iscsi-swp.1.xml
+	-test -z "$(XSLTPROC)" || $(XSLTPROC) -o $@ http://docbook.sourceforge.net/release/xsl/current/manpages/docbook.xsl $<
+

doc/iscsi-swp.1.xml

@@ -0,0 +1,146 @@
+<?xml version="1.0" encoding="iso-8859-1"?>
+<!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
+<refentry id="iscsi-swp.1">
+
+<refmeta>
+	<refentrytitle>iscsi-swp</refentrytitle>
+	<manvolnum>1</manvolnum>
+	<refmiscinfo class="source">iscsi-swp</refmiscinfo>
+	<refmiscinfo class="manual">iscsi-swp: get/set software write protect</refmiscinfo>
+</refmeta>
+
+
+<refnamediv>
+	<refname>iscsi-swp</refname>
+        <refpurpose>Utility to get/set software write protect on an iSCSI LUN</refpurpose>
+</refnamediv>
+
+<refsynopsisdiv>
+	<cmdsynopsis>
+		<command>iscsi-swp [ OPTIONS ] &lt;ISCSI-PORTAL&gt;</command>
+	</cmdsynopsis>
+	
+	<cmdsynopsis>
+		<command>iscsi-ls</command>
+		<arg choice="opt">-i --initiator-name=&lt;IQN&gt;</arg>
+		<arg choice="opt">-s --swp {on|off}</arg>
+		<arg choice="opt">-d --debug=&lt;INTEGER&gt;</arg>
+		<arg choice="opt">-? --help</arg>
+		<arg choice="opt">--usage</arg>
+	</cmdsynopsis>
+	
+</refsynopsisdiv>
+
+  <refsect1><title>DESCRIPTION</title>
+    <para>
+      iscsi-swp is a utility to get or set the software write protect on an iSCSI LUN.
+    </para>
+  </refsect1>
+
+  <refsect1><title>ISCSI PORTAL URL FORMAT</title>
+    <para>
+      iSCSI portal format is 'iscsi://[&lt;username&gt;[%&lt;password&gt;]@]&lt;host&gt;[:&lt;port&gt;]'
+    </para>
+
+    <para>
+      Username and password are only required if the target requires CHAP
+      authentication. Optionally you can specify the username and password via
+      the environment variables LIBISCSI_CHAP_USERNAME and
+      LIBISCSI_CHAP_PASSWORD.
+    </para>
+
+    <para>
+      Host can be specified either as a hostname, an IPv4 address or an
+      IPv6 address.
+
+      Examples:
+      <screen format="linespecific">
+	iscsi://192.0.2.1
+	iscsi://[2001:DB8::1]:3261
+	iscsi://ronnie%password@iscsi.example.com
+      </screen>
+    </para>
+    
+    <para>
+      Port is the TCP port on the target to connect to. Default is 3260.
+    </para>
+  </refsect1>
+
+  <refsect1>
+    <title>OPTIONS</title>
+
+    <variablelist>
+
+      <varlistentry><term>-i --initiator-name=&lt;IQN&gt;</term>
+        <listitem>
+          <para>
+            This specifies the initiator-name that iscsi-ls will use when
+	    logging in to the target.
+	  </para>
+	  <para>
+	    The default name is
+	    'iqn.2007-10.com.github:sahlberg:libiscsi:iscsi-ls' but you can use
+	    this argument to override this. This is mainly needed for cases
+	    where the target is configured with access-control to only
+	    allow discovery logins from known initiator-names.
+	  </para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry><term>-s --swp {on|off}</term>
+        <listitem>
+          <para>
+	    By default iscsi-swp will only print the current setting of
+	    the software write protect bit. By using this argument
+	    iscsi-swp will also try to set/clear the flag on the target LUN.
+	  </para>
+	  <screen format="linespecific">
+iscsi-swp iscsi://127.0.0.1/iqn.ronnie.test/1
+SWP:0
+
+iscsi-swp iscsi://127.0.0.1/iqn.ronnie.test/1 --swp on
+SWP:0
+Turning SWP ON
+
+iscsi-swp iscsi://127.0.0.1/iqn.ronnie.test/1 --swp off
+SWP:0
+Turning SWP OFF
+	  </screen>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry><term>-d --debug=&lt;INTEGER&gt;</term>
+        <listitem>
+          <para>
+	    Debug level.
+	  </para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry><term>-? --help</term>
+        <listitem>
+          <para>
+	    Display basic help text.
+	  </para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry><term>--usage</term>
+        <listitem>
+          <para>
+	    Display basic usage text.
+	  </para>
+        </listitem>
+      </varlistentry>
+
+    </variablelist>
+  </refsect1>
+
+  <refsect1><title>SEE ALSO</title>
+    <para>
+      iscsi-inq(1), iscsi-ls(1)
+      <ulink url="http://github.com/sahlberg/libiscsi"/>
+    </para>
+  </refsect1>
+
+</refentry>

src/iscsi-swp.c

@@ -0,0 +1,251 @@
+/* 
+   Copyright (C) 2013 by Ronnie Sahlberg <ronniesahlberg@gmail.com>
+   
+   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; either version 2 of the License, or
+   (at your option) any later version.
+   
+   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.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef HAVE_POLL_H
+#include <poll.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <getopt.h>
+#include "iscsi.h"
+#include "scsi-lowlevel.h"
+
+#ifndef discard_const
+#define discard_const(ptr) ((void *)((intptr_t)(ptr)))
+#endif
+
+const char *initiator = "iqn.2007-10.com.github:sahlberg:libiscsi:iscsi-swp";
+
+
+void print_usage(void)
+{
+	fprintf(stderr, "Usage: iscsi-swp [-?] [-?|--help] [--usage] [-i|--initiator-name=iqn-name]\n"
+			"\t\t[-s|--swp {on|off}] <iscsi-url>\n");
+}
+
+void print_help(void)
+{
+	fprintf(stderr, "Usage: iscsi-swp [OPTION...] <iscsi-url>\n");
+	fprintf(stderr, "  -i, --initiator-name=iqn-name     Initiatorname to use\n");
+	fprintf(stderr, "  -s, --swp={on|off}                Turn software write protect on/off\n");
+	fprintf(stderr, "  -d, --debug=integer               debug level (0=disabled)\n");
+	fprintf(stderr, "\n");
+	fprintf(stderr, "Help options:\n");
+	fprintf(stderr, "  -?, --help                        Show this help message\n");
+	fprintf(stderr, "      --usage                       Display brief usage message\n");
+	fprintf(stderr, "\n");
+	fprintf(stderr, "iSCSI URL format : %s\n", ISCSI_URL_SYNTAX);
+	fprintf(stderr, "\n");
+	fprintf(stderr, "<host> is either of:\n");
+	fprintf(stderr, "  \"hostname\"       iscsi.example\n");
+	fprintf(stderr, "  \"ipv4-address\"   10.1.1.27\n");
+	fprintf(stderr, "  \"ipv6-address\"   [fce0::1]\n");
+}
+
+int main(int argc, char *argv[])
+{
+	struct iscsi_context *iscsi;
+	const char *url = NULL;
+	struct iscsi_url *iscsi_url = NULL;
+	int show_help = 0, show_usage = 0, debug = 0;
+	int c;
+	int ret = 0;
+	int swp = 0;
+	struct scsi_task *sense_task = NULL;
+	struct scsi_task *select_task = NULL;
+	struct scsi_mode_sense *ms;
+	struct scsi_mode_page *mp;
+
+	static struct option long_options[] = {
+		{"help",           no_argument,          NULL,        'h'},
+		{"usage",          no_argument,          NULL,        'u'},
+		{"debug",          no_argument,          NULL,        'd'},
+		{"initiator_name", required_argument,    NULL,        'i'},
+		{"swp",            required_argument,    NULL,        's'},
+		{0, 0, 0, 0}
+	};
+	int option_index;
+
+	while ((c = getopt_long(argc, argv, "h?udi:s:", long_options,
+			&option_index)) != -1) {
+		switch (c) {
+		case 'h':
+		case '?':
+			show_help = 1;
+			break;
+		case 'u':
+			show_usage = 1;
+			break;
+		case 'd':
+			debug = 1;
+			break;
+		case 'i':
+			initiator = optarg;
+			break;
+		case 's':
+			if (!strcmp(optarg, "on") || !strcmp(optarg, "ON")) {
+				swp = 1;
+			}
+			if (!strcmp(optarg, "off") || !strcmp(optarg, "OFF")) {
+				swp = 2;
+			}
+			break;
+		default:
+			fprintf(stderr, "Unrecognized option '%c'\n\n", c);
+			print_help();
+			exit(0);
+		}
+	}
+
+	if (show_help != 0) {
+		print_help();
+		exit(0);
+	}
+
+	if (show_usage != 0) {
+		print_usage();
+		exit(0);
+	}
+
+	iscsi = iscsi_create_context(initiator);
+	if (iscsi == NULL) {
+		fprintf(stderr, "Failed to create context\n");
+		exit(10);
+	}
+
+	if (debug > 0) {
+		iscsi_set_log_level(iscsi, debug);
+		iscsi_set_log_fn(iscsi, iscsi_log_to_stderr);
+	}
+
+	url = strdup(argv[optind]);
+	if (url == NULL) {
+		fprintf(stderr, "You must specify the URL\n");
+		print_usage();
+		ret = 10;
+		goto finished;
+	}
+	iscsi_url = iscsi_parse_full_url(iscsi, url);
+	
+	free(discard_const(url));
+
+	if (iscsi_url == NULL) {
+		fprintf(stderr, "Failed to parse URL: %s\n", 
+			iscsi_get_error(iscsi));
+		ret = 10;
+		goto finished;
+	}
+
+	iscsi_set_targetname(iscsi, iscsi_url->target);
+	iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL);
+	iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
+
+	if (iscsi_url->user != NULL) {
+		if (iscsi_set_initiator_username_pwd(iscsi, iscsi_url->user, iscsi_url->passwd) != 0) {
+			fprintf(stderr, "Failed to set initiator username and password\n");
+			ret = 10;
+			goto finished;
+		}
+	}
+
+	if (iscsi_full_connect_sync(iscsi, iscsi_url->portal, iscsi_url->lun) != 0) {
+		fprintf(stderr, "Login Failed. %s\n", iscsi_get_error(iscsi));
+		ret = 10;
+		goto finished;
+	}
+
+
+	sense_task = iscsi_modesense6_sync(iscsi, iscsi_url->lun,
+		0, SCSI_MODESENSE_PC_CURRENT,
+		SCSI_MODESENSE_PAGECODE_CONTROL,
+		0, 255);
+	if (sense_task == NULL) {
+		printf("Failed to send MODE_SENSE6 command: %s\n",
+			iscsi_get_error(iscsi));
+		ret = 10;
+		goto finished;
+	}
+	if (sense_task->status != SCSI_STATUS_GOOD) {
+		printf("MODE_SENSE6 failed: %s\n",
+			iscsi_get_error(iscsi));
+		ret = 10;
+		goto finished;
+	}
+	ms = scsi_datain_unmarshall(sense_task);
+	if (ms == NULL) {
+		printf("failed to unmarshall mode sense datain blob\n");
+		ret = 10;
+		goto finished;
+	}
+	mp = scsi_modesense_get_page(ms, SCSI_MODESENSE_PAGECODE_CONTROL, 0);
+	if (mp == NULL) {
+		printf("failed to read control mode page\n");
+		ret = 10;
+		goto finished;
+	}
+
+	printf("SWP:%d\n", mp->control.swp);
+
+	switch (swp) {
+	case 1:
+		mp->control.swp = 1;
+		break;
+	case 2:
+		mp->control.swp = 0;
+		break;
+	default:
+		goto finished;
+	}
+
+	printf("Turning SWP %s\n", (swp == 1) ? "ON" : "OFF"); 
+	select_task = iscsi_modeselect6_sync(iscsi, iscsi_url->lun,
+		    1, 0, mp);
+	if (select_task == NULL) {
+		printf("Failed to send MODE_SELECT6 command: %s\n",
+			iscsi_get_error(iscsi));
+		ret = 10;
+		goto finished;
+	}
+	if (select_task->status != SCSI_STATUS_GOOD) {
+		printf("MODE_SELECT6 failed: %s\n",
+			iscsi_get_error(iscsi));
+		ret = 10;
+		goto finished;
+	}
+
+
+finished:
+	if (sense_task != NULL) {
+		scsi_free_scsi_task(sense_task);
+	}
+	if (select_task != NULL) {
+		scsi_free_scsi_task(select_task);
+	}
+	if (iscsi_url != NULL) {
+		iscsi_destroy_url(iscsi_url);
+	}
+	iscsi_logout_sync(iscsi);
+	iscsi_destroy_context(iscsi);
+	return ret;
+}
+