[RFC PATCH ethtool-next 2/6] ethtool: Add ability to control transceiver modules' low power mode

@@ -39,7 +39,7 @@ ethtool_SOURCES += \
 		  netlink/eee.c netlink/tsinfo.c netlink/fec.c \
 		  netlink/stats.c \
 		  netlink/desc-ethtool.c netlink/desc-genlctrl.c \
-		  netlink/module-eeprom.c \
+		  netlink/module-eeprom.c netlink/module.c \
 		  netlink/desc-rtnl.c netlink/cable_test.c netlink/tunnels.c \
 		  uapi/linux/ethtool_netlink.h \
 		  uapi/linux/netlink.h uapi/linux/genetlink.h \

@@ -475,6 +475,13 @@ ethtool \- query or control network driver and hardware settings
 .HP
 .B ethtool \-\-show\-tunnels
 .I devname
+.HP
+.B ethtool \-\-show\-module
+.I devname
+.HP
+.B ethtool \-\-set\-module
+.I devname
+.B2 low-power on off
 .
 .\" Adjust lines (i.e. full justification) and hyphenate.
 .ad

@@ -1458,6 +1465,14 @@ Show tunnel-related device capabilities and state.
 List UDP ports kernel has programmed the device to parse as VxLAN,
 or GENEVE tunnels.
 .RE
+.TP
+.B \-\-set\-module
+Set the transceiver module's parameters.
+.RS 4
+.TP
+.A2 low-power on off
+Enable / disable forcing of low power mode by the host.
+.RE
 .SH BUGS
 Not supported (in part or whole) on all network drivers.
 .SH AUTHOR

@@ -6020,6 +6020,17 @@ static const struct option args[] = {
 		.nlfunc	= nl_gtunnels,
 		.help	= "Show NIC tunnel offload information",
 	},
+	{
+		.opts	= "--show-module",
+		.nlfunc	= nl_gmodule,
+		.help	= "Show transceiver module settings",
+	},
+	{
+		.opts	= "--set-module",
+		.nlfunc	= nl_smodule,
+		.help	= "Set transceiver module settings",
+		.xhelp	= "		[ low-power on|off ]\n"
+	},
 	{
 		.opts	= "-h|--help",
 		.no_dev	= true,

@@ -374,6 +374,12 @@ const struct pretty_nla_desc __module_eeprom_desc[] = {
 	NLATTR_DESC_BINARY(ETHTOOL_A_MODULE_EEPROM_DATA)
 };
 
+static const struct pretty_nla_desc __module_desc[] = {
+	NLATTR_DESC_INVALID(ETHTOOL_A_MODULE_UNSPEC),
+	NLATTR_DESC_NESTED(ETHTOOL_A_MODULE_HEADER, header),
+	NLATTR_DESC_BOOL(ETHTOOL_A_MODULE_LOW_POWER_ENABLED),
+};
+
 const struct pretty_nlmsg_desc ethnl_umsg_desc[] = {
 	NLMSG_DESC_INVALID(ETHTOOL_MSG_USER_NONE),
 	NLMSG_DESC(ETHTOOL_MSG_STRSET_GET, strset),

@@ -408,6 +414,8 @@ const struct pretty_nlmsg_desc ethnl_umsg_desc[] = {
 	NLMSG_DESC(ETHTOOL_MSG_FEC_SET, fec),
 	NLMSG_DESC(ETHTOOL_MSG_STATS_GET, stats),
 	NLMSG_DESC(ETHTOOL_MSG_MODULE_EEPROM_GET, module_eeprom),
+	NLMSG_DESC(ETHTOOL_MSG_MODULE_GET, module),
+	NLMSG_DESC(ETHTOOL_MSG_MODULE_SET, module),
 };
 
 const unsigned int ethnl_umsg_n_desc = ARRAY_SIZE(ethnl_umsg_desc);

@@ -447,6 +455,8 @@ const struct pretty_nlmsg_desc ethnl_kmsg_desc[] = {
 	NLMSG_DESC(ETHTOOL_MSG_FEC_NTF, fec),
 	NLMSG_DESC(ETHTOOL_MSG_STATS_GET_REPLY, stats),
 	NLMSG_DESC(ETHTOOL_MSG_MODULE_EEPROM_GET_REPLY, module_eeprom),
+	NLMSG_DESC(ETHTOOL_MSG_MODULE_GET_REPLY, module),
+	NLMSG_DESC(ETHTOOL_MSG_MODULE_NTF, module),
 };
 
 const unsigned int ethnl_kmsg_n_desc = ARRAY_SIZE(ethnl_kmsg_desc);

@@ -43,6 +43,8 @@ int nl_gfec(struct cmd_context *ctx);
 int nl_sfec(struct cmd_context *ctx);
 bool nl_gstats_chk(struct cmd_context *ctx);
 int nl_gstats(struct cmd_context *ctx);
+int nl_gmodule(struct cmd_context *ctx);
+int nl_smodule(struct cmd_context *ctx);
 int nl_monitor(struct cmd_context *ctx);
 int nl_getmodule(struct cmd_context *ctx);
 

@@ -99,6 +101,8 @@ static inline void nl_monitor_usage(void)
 #define nl_gstats_chk		NULL
 #define nl_gstats		NULL
 #define nl_getmodule		NULL
+#define nl_gmodule		NULL
+#define nl_smodule		NULL
 
 #endif /* ETHTOOL_ENABLE_NETLINK */
 

@@ -0,0 +1,139 @@
+/*
+ * module.c - netlink implementation of module commands
+ *
+ * Implementation of "ethtool --show-module <dev>" and
+ * "ethtool --set-module <dev> ..."
+ */
+
+#include <errno.h>
+#include <ctype.h>
+#include <inttypes.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "../internal.h"
+#include "../common.h"
+#include "netlink.h"
+#include "parser.h"
+
+/* MODULE_GET */
+
+int module_reply_cb(const struct nlmsghdr *nlhdr, void *data)
+{
+	const struct nlattr *tb[ETHTOOL_A_MODULE_MAX + 1] = {};
+	struct nl_context *nlctx = data;
+	DECLARE_ATTR_TB_INFO(tb);
+	bool silent;
+	int err_ret;
+	int ret;
+
+	silent = nlctx->is_dump || nlctx->is_monitor;
+	err_ret = silent ? MNL_CB_OK : MNL_CB_ERROR;
+	ret = mnl_attr_parse(nlhdr, GENL_HDRLEN, attr_cb, &tb_info);
+	if (ret < 0)
+		return err_ret;
+	nlctx->devname = get_dev_name(tb[ETHTOOL_A_MODULE_HEADER]);
+	if (!dev_ok(nlctx))
+		return err_ret;
+
+	if (silent)
+		print_nl();
+
+	open_json_object(NULL);
+
+	print_string(PRINT_ANY, "ifname", "Module parameters for %s:\n",
+		     nlctx->devname);
+
+	if (tb[ETHTOOL_A_MODULE_LOW_POWER_ENABLED]) {
+		bool low_power;
+
+		low_power =
+			mnl_attr_get_u8(tb[ETHTOOL_A_MODULE_LOW_POWER_ENABLED]);
+		print_bool(PRINT_ANY, "low-power", "low-power %s\n", low_power);
+	}
+
+	close_json_object();
+
+	return MNL_CB_OK;
+}
+
+int nl_gmodule(struct cmd_context *ctx)
+{
+	struct nl_context *nlctx = ctx->nlctx;
+	struct nl_socket *nlsk;
+	int ret;
+
+	if (netlink_cmd_check(ctx, ETHTOOL_MSG_MODULE_GET, true))
+		return -EOPNOTSUPP;
+	if (ctx->argc > 0) {
+		fprintf(stderr, "ethtool: unexpected parameter '%s'\n",
+			*ctx->argp);
+		return 1;
+	}
+
+	nlsk = nlctx->ethnl_socket;
+	ret = nlsock_prep_get_request(nlsk, ETHTOOL_MSG_MODULE_GET,
+				      ETHTOOL_A_MODULE_HEADER, 0);
+	if (ret < 0)
+		return ret;
+
+	new_json_obj(ctx->json);
+	ret = nlsock_send_get_request(nlsk, module_reply_cb);
+	delete_json_obj();
+	return ret;
+}
+
+/* MODULE_SET */
+
+static const struct param_parser smodule_params[] = {
+	{
+		.arg		= "low-power",
+		.type		= ETHTOOL_A_MODULE_LOW_POWER_ENABLED,
+		.handler	= nl_parse_u8bool,
+		.min_argc	= 1,
+	},
+	{}
+};
+
+int nl_smodule(struct cmd_context *ctx)
+{
+	struct nl_context *nlctx = ctx->nlctx;
+	struct nl_msg_buff *msgbuff;
+	struct nl_socket *nlsk;
+	int ret;
+
+	if (netlink_cmd_check(ctx, ETHTOOL_MSG_MODULE_SET, false))
+		return -EOPNOTSUPP;
+	if (!ctx->argc) {
+		fprintf(stderr, "ethtool (--set-module): parameters missing\n");
+		return 1;
+	}
+
+	nlctx->cmd = "--set-module";
+	nlctx->argp = ctx->argp;
+	nlctx->argc = ctx->argc;
+	nlctx->devname = ctx->devname;
+	nlsk = nlctx->ethnl_socket;
+	msgbuff = &nlsk->msgbuff;
+
+	ret = msg_init(nlctx, msgbuff, ETHTOOL_MSG_MODULE_SET,
+		       NLM_F_REQUEST | NLM_F_ACK);
+	if (ret < 0)
+		return 2;
+	if (ethnla_fill_header(msgbuff, ETHTOOL_A_MODULE_HEADER,
+			       ctx->devname, 0))
+		return -EMSGSIZE;
+
+	ret = nl_parser(nlctx, smodule_params, NULL, PARSER_GROUP_NONE, NULL);
+	if (ret < 0)
+		return 1;
+
+	ret = nlsock_sendmsg(nlsk, NULL);
+	if (ret < 0)
+		return 83;
+	ret = nlsock_process_reply(nlsk, nomsg_reply_cb, nlctx);
+	if (ret == 0)
+		return 0;
+	else
+		return nlctx->exit_code ?: 83;
+}

@@ -71,6 +71,10 @@ static struct {
 		.cmd	= ETHTOOL_MSG_FEC_NTF,
 		.cb	= fec_reply_cb,
 	},
+	{
+		.cmd	= ETHTOOL_MSG_MODULE_NTF,
+		.cb	= module_reply_cb,
+	},
 };
 
 static void clear_filter(struct nl_context *nlctx)

@@ -91,6 +91,7 @@ int cable_test_ntf_cb(const struct nlmsghdr *nlhdr, void *data);
 int cable_test_tdr_reply_cb(const struct nlmsghdr *nlhdr, void *data);
 int cable_test_tdr_ntf_cb(const struct nlmsghdr *nlhdr, void *data);
 int fec_reply_cb(const struct nlmsghdr *nlhdr, void *data);
+int module_reply_cb(const struct nlmsghdr *nlhdr, void *data);
 
 /* dump helpers */
 

@@ -1137,6 +1137,26 @@ _ethtool_test()
 	fi
 }
 
+# Completion for ethtool --set-module
+_ethtool_set_module()
+{
+	local -A settings=(
+		[low-power]=1
+	)
+
+	if [ "${settings[$prev]+set}" ]; then
+		COMPREPLY=( $( compgen -W 'on off' -- "$cur" ) )
+		return
+	fi
+
+	# Remove settings which have been seen
+	local word
+	for word in "${words[@]:3:${#words[@]}-4}"; do
+		unset "settings[$word]"
+	done
+
+	COMPREPLY=( $( compgen -W "${!settings[*]}" -- "$cur" ) )
+}
 
 # Complete any ethtool command
 _ethtool()

@@ -1189,6 +1209,8 @@ _ethtool()
 		[--show-time-stamping]=devname
 		[--statistics]=devname
 		[--test]=test
+		[--set-module]=set_module
+		[--show-module]=devname
 	)
 	local -A other_funcs=(
 		[--config-ntuple]=config_nfc