Make it possible to set (via iscsi.conf(5)) and query (via iscsictl -v)

initiator iSCSI offload.  Pass maximum data segment size supported by
chosen offload module to iscsid(8), and make iscsid(8) not try to negotiate
anything larger than that.

MFC after:	1 month
Sponsored by:	The FreeBSD Foundation

5 files changed, 21 insertions, 3 deletions

diff --git a/usr.bin/iscsictl/iscsi.conf.5 b/usr.bin/iscsictl/iscsi.conf.5
index 0343385..c0c326a 100644
--- a/usr.bin/iscsictl/iscsi.conf.5
+++ b/usr.bin/iscsictl/iscsi.conf.5
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd December 17, 2013
+.Dd February 4, 2015
 .Dt ISCSI.CONF 5
 .Os
 .Sh NAME
@@ -110,6 +110,8 @@ flag of
 The following are not specified in the
 .Sy RFC 3720
 .Bl -tag -width sockbufsize
+.It Cm offload
+Name of selected iSCSI hardware offload driver.
 .It Cm port
 The iSCSI port used by the iSCSI protocol, defaults to 3260.
 .It Cm tags
diff --git a/usr.bin/iscsictl/iscsictl.c b/usr.bin/iscsictl/iscsictl.c
index a27e32b..e6abf93 100644
--- a/usr.bin/iscsictl/iscsictl.c
+++ b/usr.bin/iscsictl/iscsictl.c
@@ -327,6 +327,9 @@ conf_from_target(struct iscsi_session_conf *conf,
 		conf->isc_discovery = 1;
 	if (targ->t_protocol == PROTOCOL_ISER)
 		conf->isc_iser = 1;
+	if (targ->t_offload != NULL)
+		strlcpy(conf->isc_offload, targ->t_offload,
+		    sizeof(conf->isc_offload));
 	if (targ->t_header_digest == DIGEST_CRC32C)
 		conf->isc_header_digest = ISCSI_DIGEST_CRC32C;
 	else
@@ -517,6 +520,7 @@ kernel_list(int iscsi_fd, const struct target *targ __unused,
 			    state->iss_immediate_data ? "Yes" : "No");
 			printf("iSER (RDMA):      %s\n",
 			    conf->isc_iser ? "Yes" : "No");
+			printf("Offload driver:   %s\n", state->iss_offload);
 			printf("Device nodes:     ");
 			print_periphs(state->iss_id);
 			printf("\n\n");
diff --git a/usr.bin/iscsictl/iscsictl.h b/usr.bin/iscsictl/iscsictl.h
index e8d4768..727e8ae 100644
--- a/usr.bin/iscsictl/iscsictl.h
+++ b/usr.bin/iscsictl/iscsictl.h
@@ -72,6 +72,7 @@ struct target {
 	int			t_auth_method;
 	int			t_session_type;
 	int			t_protocol;
+	char			*t_offload;
 	char			*t_user;
 	char			*t_secret;
 	char			*t_mutual_user;
diff --git a/usr.bin/iscsictl/parse.y b/usr.bin/iscsictl/parse.y
index e6343f8..7beb53e 100644
--- a/usr.bin/iscsictl/parse.y
+++ b/usr.bin/iscsictl/parse.y
@@ -57,8 +57,8 @@ extern void	yyrestart(FILE *);
 
 %token AUTH_METHOD HEADER_DIGEST DATA_DIGEST TARGET_NAME TARGET_ADDRESS
 %token INITIATOR_NAME INITIATOR_ADDRESS INITIATOR_ALIAS USER SECRET
-%token MUTUAL_USER MUTUAL_SECRET SEMICOLON SESSION_TYPE PROTOCOL IGNORED
-%token EQUALS OPENING_BRACKET CLOSING_BRACKET
+%token MUTUAL_USER MUTUAL_SECRET SEMICOLON SESSION_TYPE PROTOCOL OFFLOAD
+%token IGNORED EQUALS OPENING_BRACKET CLOSING_BRACKET
 
 %union
 {
@@ -117,6 +117,8 @@ target_entry:
 	|
 	session_type
 	|
+	offload
+	|
 	protocol
 	|
 	ignored
@@ -250,6 +252,14 @@ session_type:	SESSION_TYPE EQUALS STR
 	}
 	;
 
+offload:	OFFLOAD EQUALS STR
+	{
+		if (target->t_offload != NULL)
+			errx(1, "duplicated offload at line %d", lineno);
+		target->t_offload = $3;
+	}
+	;
+
 protocol:	PROTOCOL EQUALS STR
 	{
 		if (target->t_protocol != PROTOCOL_UNSPECIFIED)
diff --git a/usr.bin/iscsictl/token.l b/usr.bin/iscsictl/token.l
index 06af167..8cf2fec 100644
--- a/usr.bin/iscsictl/token.l
+++ b/usr.bin/iscsictl/token.l
@@ -63,6 +63,7 @@ tgtChapSecret		{ return MUTUAL_SECRET; }
 AuthMethod		{ return AUTH_METHOD; }
 SessionType		{ return SESSION_TYPE; }
 protocol		{ return PROTOCOL; }
+offload			{ return OFFLOAD; }
 port			{ return IGNORED; }
 MaxConnections		{ return IGNORED; }
 TargetAlias		{ return IGNORED; }