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From:   Era Mayflower <mayflowerera@gmail.com>
To:     davem@davemloft.net, kuba@kernel.org
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        mayflowerera@gmail.com
Subject: [PATCH v2] macsec: Support 32bit PN netlink attribute for XPN links
Date:   Thu, 10 Sep 2020 09:56:09 +0000
Message-Id: <20200910095609.17999-1-mayflowerera@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Allow using 32bit netlink attribute for packet number when creating or
updating SA in an XPN link.
Now utilities like iproute2's `ip` do not have to know the link type
(XPN or not) when setting the packet number field of an SA.

Signed-off-by: Era Mayflower <mayflowerera@gmail.com>
---
 drivers/net/macsec.c | 95 ++++++++++++++++++++++++++++++++------------
 1 file changed, 69 insertions(+), 26 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index e56547bfdac9..7d3c3a38ea81 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -1691,8 +1691,7 @@ static bool validate_add_rxsa(struct nlattr **attrs)
 	if (nla_get_u8(attrs[MACSEC_SA_ATTR_AN]) >= MACSEC_NUM_AN)
 		return false;
 
-	if (attrs[MACSEC_SA_ATTR_PN] &&
-	    *(u64 *)nla_data(attrs[MACSEC_SA_ATTR_PN]) == 0)
+	if (attrs[MACSEC_SA_ATTR_PN] && nla_get_u64(attrs[MACSEC_SA_ATTR_PN]) == 0)
 		return false;
 
 	if (attrs[MACSEC_SA_ATTR_ACTIVE]) {
@@ -1714,7 +1713,6 @@ static int macsec_add_rxsa(struct sk_buff *skb, struct genl_info *info)
 	struct macsec_rx_sc *rx_sc;
 	struct macsec_rx_sa *rx_sa;
 	unsigned char assoc_num;
-	int pn_len;
 	struct nlattr *tb_rxsc[MACSEC_RXSC_ATTR_MAX + 1];
 	struct nlattr *tb_sa[MACSEC_SA_ATTR_MAX + 1];
 	int err;
@@ -1747,12 +1745,26 @@ static int macsec_add_rxsa(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 	}
 
-	pn_len = secy->xpn ? MACSEC_XPN_PN_LEN : MACSEC_DEFAULT_PN_LEN;
-	if (nla_len(tb_sa[MACSEC_SA_ATTR_PN]) != pn_len) {
-		pr_notice("macsec: nl: add_rxsa: bad pn length: %d != %d\n",
-			  nla_len(tb_sa[MACSEC_SA_ATTR_PN]), pn_len);
-		rtnl_unlock();
-		return -EINVAL;
+	if (tb_sa[MACSEC_SA_ATTR_PN]) {
+		switch (nla_len(tb_sa[MACSEC_SA_ATTR_PN])) {
+		case MACSEC_DEFAULT_PN_LEN:
+			break;
+
+		case MACSEC_XPN_PN_LEN:
+			if (secy->xpn)
+				break;
+
+			pr_notice("macsec: nl: add_rxsa: pn length on non-xpn links must be %d\n",
+				  MACSEC_DEFAULT_PN_LEN);
+			rtnl_unlock();
+			return -EINVAL;
+
+		default:
+			pr_notice("macsec: nl: add_rxsa: pn length must be %d or %d\n",
+				  MACSEC_DEFAULT_PN_LEN, MACSEC_XPN_PN_LEN);
+			rtnl_unlock();
+			return -EINVAL;
+		}
 	}
 
 	if (secy->xpn) {
@@ -1934,7 +1946,7 @@ static bool validate_add_txsa(struct nlattr **attrs)
 	if (nla_get_u8(attrs[MACSEC_SA_ATTR_AN]) >= MACSEC_NUM_AN)
 		return false;
 
-	if (nla_get_u32(attrs[MACSEC_SA_ATTR_PN]) == 0)
+	if (nla_get_u64(attrs[MACSEC_SA_ATTR_PN]) == 0)
 		return false;
 
 	if (attrs[MACSEC_SA_ATTR_ACTIVE]) {
@@ -1956,7 +1968,6 @@ static int macsec_add_txsa(struct sk_buff *skb, struct genl_info *info)
 	struct macsec_tx_sc *tx_sc;
 	struct macsec_tx_sa *tx_sa;
 	unsigned char assoc_num;
-	int pn_len;
 	struct nlattr *tb_sa[MACSEC_SA_ATTR_MAX + 1];
 	bool was_operational;
 	int err;
@@ -1989,10 +2000,22 @@ static int macsec_add_txsa(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 	}
 
-	pn_len = secy->xpn ? MACSEC_XPN_PN_LEN : MACSEC_DEFAULT_PN_LEN;
-	if (nla_len(tb_sa[MACSEC_SA_ATTR_PN]) != pn_len) {
-		pr_notice("macsec: nl: add_txsa: bad pn length: %d != %d\n",
-			  nla_len(tb_sa[MACSEC_SA_ATTR_PN]), pn_len);
+	switch (nla_len(tb_sa[MACSEC_SA_ATTR_PN])) {
+	case MACSEC_DEFAULT_PN_LEN:
+		break;
+
+	case MACSEC_XPN_PN_LEN:
+		if (secy->xpn)
+			break;
+
+		pr_notice("macsec: nl: add_txsa: pn length on non-xpn links must be %d\n",
+			  MACSEC_DEFAULT_PN_LEN);
+		rtnl_unlock();
+		return -EINVAL;
+
+	default:
+		pr_notice("macsec: nl: add_txsa: pn length must be %d or %d\n",
+			  MACSEC_DEFAULT_PN_LEN, MACSEC_XPN_PN_LEN);
 		rtnl_unlock();
 		return -EINVAL;
 	}
@@ -2288,7 +2311,7 @@ static bool validate_upd_sa(struct nlattr **attrs)
 	if (nla_get_u8(attrs[MACSEC_SA_ATTR_AN]) >= MACSEC_NUM_AN)
 		return false;
 
-	if (attrs[MACSEC_SA_ATTR_PN] && nla_get_u32(attrs[MACSEC_SA_ATTR_PN]) == 0)
+	if (attrs[MACSEC_SA_ATTR_PN] && nla_get_u64(attrs[MACSEC_SA_ATTR_PN]) == 0)
 		return false;
 
 	if (attrs[MACSEC_SA_ATTR_ACTIVE]) {
@@ -2332,12 +2355,22 @@ static int macsec_upd_txsa(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	if (tb_sa[MACSEC_SA_ATTR_PN]) {
-		int pn_len;
+		switch (nla_len(tb_sa[MACSEC_SA_ATTR_PN])) {
+		case MACSEC_DEFAULT_PN_LEN:
+			break;
+
+		case MACSEC_XPN_PN_LEN:
+			if (secy->xpn)
+				break;
+
+			pr_notice("macsec: nl: upd_txsa: pn length on non-xpn links must be %d\n",
+				  MACSEC_DEFAULT_PN_LEN);
+			rtnl_unlock();
+			return -EINVAL;
 
-		pn_len = secy->xpn ? MACSEC_XPN_PN_LEN : MACSEC_DEFAULT_PN_LEN;
-		if (nla_len(tb_sa[MACSEC_SA_ATTR_PN]) != pn_len) {
-			pr_notice("macsec: nl: upd_txsa: bad pn length: %d != %d\n",
-				  nla_len(tb_sa[MACSEC_SA_ATTR_PN]), pn_len);
+		default:
+			pr_notice("macsec: nl: upd_txsa: pn length must be %d or %d\n",
+				  MACSEC_DEFAULT_PN_LEN, MACSEC_XPN_PN_LEN);
 			rtnl_unlock();
 			return -EINVAL;
 		}
@@ -2429,12 +2462,22 @@ static int macsec_upd_rxsa(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	if (tb_sa[MACSEC_SA_ATTR_PN]) {
-		int pn_len;
+		switch (nla_len(tb_sa[MACSEC_SA_ATTR_PN])) {
+		case MACSEC_DEFAULT_PN_LEN:
+			break;
+
+		case MACSEC_XPN_PN_LEN:
+			if (secy->xpn)
+				break;
 
-		pn_len = secy->xpn ? MACSEC_XPN_PN_LEN : MACSEC_DEFAULT_PN_LEN;
-		if (nla_len(tb_sa[MACSEC_SA_ATTR_PN]) != pn_len) {
-			pr_notice("macsec: nl: upd_rxsa: bad pn length: %d != %d\n",
-				  nla_len(tb_sa[MACSEC_SA_ATTR_PN]), pn_len);
+			pr_notice("macsec: nl: upd_rxsa: pn length on non-xpn links must be %d\n",
+				  MACSEC_DEFAULT_PN_LEN);
+			rtnl_unlock();
+			return -EINVAL;
+
+		default:
+			pr_notice("macsec: nl: upd_rxsa: pn length must be %d or %d\n",
+				  MACSEC_DEFAULT_PN_LEN, MACSEC_XPN_PN_LEN);
 			rtnl_unlock();
 			return -EINVAL;
 		}

base-commit: bc7d17d55762421b98089f5f7496e48cab89de50
-- 
2.20.1