ethtool/SOURCES/0026-ethtool-Improve-compatibility-between-netlink-and-io.patch

From f16bc54fe82b9129d6852273d02e044b9cb28789 Mon Sep 17 00:00:00 2001
From: Ido Schimmel <idosch@nvidia.com>
Date: Mon, 9 Nov 2020 14:29:59 +0100
Subject: [PATCH 26/26] ethtool: Improve compatibility between netlink and
 ioctl interfaces

With the ioctl interface, when autoneg is enabled, but without
specifying speed, duplex or link modes, the advertised link modes are
set to the supported link modes by the ethtool user space utility.

This does not happen when using the netlink interface. Fix this
incompatibility problem by having ethtool query the supported link modes
from the kernel and advertise all the "real" ones when only "autoneg on"
is specified.

Before:

Settings for eth0:
	Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Full
	Supported pause frame use: No
	Supports auto-negotiation: Yes
	Supported FEC modes: Not reported
	Advertised link modes:  100baseT/Half 100baseT/Full
	Advertised pause frame use: No
	Advertised auto-negotiation: Yes
	Advertised FEC modes: Not reported
	Speed: 1000Mb/s
	Duplex: Full
	Auto-negotiation: on
	Port: Twisted Pair
	PHYAD: 0
	Transceiver: internal
	MDI-X: off (auto)
	Supports Wake-on: umbg
	Wake-on: d
        Current message level: 0x00000007 (7)
                               drv probe link
	Link detected: yes

After:

Settings for eth0:
	Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Full
	Supported pause frame use: No
	Supports auto-negotiation: Yes
	Supported FEC modes: Not reported
	Advertised link modes:  10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Full
	Advertised pause frame use: No
	Advertised auto-negotiation: Yes
	Advertised FEC modes: Not reported
	Speed: 1000Mb/s
	Duplex: Full
	Auto-negotiation: on
	Port: Twisted Pair
	PHYAD: 0
	Transceiver: internal
	MDI-X: on (auto)
	Supports Wake-on: umbg
	Wake-on: d
        Current message level: 0x00000007 (7)
                               drv probe link
	Link detected: yes

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
(cherry picked from commit 124a3c06d1c34b125d84a9eb312fddd365bb7bf6)
---
 netlink/settings.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)

diff --git a/netlink/settings.c b/netlink/settings.c
index fac192e2fbb7..01c1d38d323f 100644
--- a/netlink/settings.c
+++ b/netlink/settings.c
@@ -1113,6 +1113,93 @@ static const struct param_parser sset_params[] = {
  */
 #define SSET_MAX_MSGS 4
 
+static int linkmodes_reply_advert_all_cb(const struct nlmsghdr *nlhdr,
+					 void *data)
+{
+	const struct nlattr *tb[ETHTOOL_A_LINKMODES_MAX + 1] = {};
+	DECLARE_ATTR_TB_INFO(tb);
+	struct nl_msg_buff *req_msgbuff = data;
+	const struct nlattr *ours_attr;
+	struct nlattr *req_bitset;
+	uint32_t *supported_modes;
+	unsigned int modes_count;
+	unsigned int i;
+	int ret;
+
+	ret = mnl_attr_parse(nlhdr, GENL_HDRLEN, attr_cb, &tb_info);
+	if (ret < 0)
+		return MNL_CB_ERROR;
+	ours_attr = tb[ETHTOOL_A_LINKMODES_OURS];
+	if (!ours_attr)
+		return MNL_CB_ERROR;
+	modes_count = bitset_get_count(tb[ETHTOOL_A_LINKMODES_OURS], &ret);
+	if (ret < 0)
+		return MNL_CB_ERROR;
+	supported_modes = get_compact_bitset_mask(tb[ETHTOOL_A_LINKMODES_OURS]);
+	if (!supported_modes)
+		return MNL_CB_ERROR;
+
+	/* keep only "real" link modes */
+	for (i = 0; i < modes_count; i++)
+		if (!lm_class_match(i, LM_CLASS_REAL))
+			supported_modes[i / 32] &= ~((uint32_t)1 << (i % 32));
+
+	req_bitset = ethnla_nest_start(req_msgbuff, ETHTOOL_A_LINKMODES_OURS);
+	if (!req_bitset)
+		return MNL_CB_ERROR;
+
+	if (ethnla_put_u32(req_msgbuff, ETHTOOL_A_BITSET_SIZE, modes_count) ||
+	    ethnla_put(req_msgbuff, ETHTOOL_A_BITSET_VALUE,
+		       DIV_ROUND_UP(modes_count, 32) * sizeof(uint32_t),
+		       supported_modes) ||
+	    ethnla_put(req_msgbuff, ETHTOOL_A_BITSET_MASK,
+		       DIV_ROUND_UP(modes_count, 32) * sizeof(uint32_t),
+		       supported_modes)) {
+		ethnla_nest_cancel(req_msgbuff, req_bitset);
+		return MNL_CB_ERROR;
+	}
+
+	ethnla_nest_end(req_msgbuff, req_bitset);
+	return MNL_CB_OK;
+}
+
+/* For compatibility reasons with ioctl-based ethtool, when "autoneg on" is
+ * specified without "advertise", "speed" and "duplex", we need to query the
+ * supported link modes from the kernel and advertise all the "real" ones.
+ */
+static int nl_sset_compat_linkmodes(struct nl_context *nlctx,
+				    struct nl_msg_buff *msgbuff)
+{
+	const struct nlattr *tb[ETHTOOL_A_LINKMODES_MAX + 1] = {};
+	DECLARE_ATTR_TB_INFO(tb);
+	struct nl_socket *nlsk = nlctx->ethnl_socket;
+	int ret;
+
+	ret = mnl_attr_parse(msgbuff->nlhdr, GENL_HDRLEN, attr_cb, &tb_info);
+	if (ret < 0)
+		return ret;
+	if (!tb[ETHTOOL_A_LINKMODES_AUTONEG] || tb[ETHTOOL_A_LINKMODES_OURS] ||
+	    tb[ETHTOOL_A_LINKMODES_SPEED] || tb[ETHTOOL_A_LINKMODES_DUPLEX])
+		return 0;
+	if (!mnl_attr_get_u8(tb[ETHTOOL_A_LINKMODES_AUTONEG]))
+		return 0;
+
+	/* all conditions satisfied, create ETHTOOL_A_LINKMODES_OURS */
+	if (netlink_cmd_check(nlctx->ctx, ETHTOOL_MSG_LINKMODES_GET, false) ||
+	    netlink_cmd_check(nlctx->ctx, ETHTOOL_MSG_LINKMODES_SET, false))
+		return -EOPNOTSUPP;
+	ret = nlsock_prep_get_request(nlsk, ETHTOOL_MSG_LINKMODES_GET,
+				      ETHTOOL_A_LINKMODES_HEADER,
+				      ETHTOOL_FLAG_COMPACT_BITSETS);
+	if (ret < 0)
+		return ret;
+	ret = nlsock_sendmsg(nlsk, NULL);
+	if (ret < 0)
+		return ret;
+	return nlsock_process_reply(nlsk, linkmodes_reply_advert_all_cb,
+				    msgbuff);
+}
+
 int nl_sset(struct cmd_context *ctx)
 {
 	struct nl_msg_buff *msgbuffs[SSET_MAX_MSGS] = {};
@@ -1134,6 +1221,11 @@ int nl_sset(struct cmd_context *ctx)
 	for (i = 0; i < SSET_MAX_MSGS && msgbuffs[i]; i++) {
 		struct nl_socket *nlsk = nlctx->ethnl_socket;
 
+		if (msgbuffs[i]->genlhdr->cmd == ETHTOOL_MSG_LINKMODES_SET) {
+			ret = nl_sset_compat_linkmodes(nlctx, msgbuffs[i]);
+			if (ret < 0)
+				goto out_free;
+		}
 		ret = nlsock_sendmsg(nlsk, msgbuffs[i]);
 		if (ret < 0)
 			goto out_free;
-- 
2.26.2