[PATCH v3 2/2] macsec: Netlink support of XPN cipher suites (IEEE 802.1AEbw)

From: Era Mayflower
Date: Mon Mar 09 2020 - 06:47:27 EST


Netlink support of extended packet number cipher suites,
allows adding and updating XPN macsec interfaces.

Added support in:
* Creating interfaces with GCM-AES-XPN-128 and GCM-AES-XPN-256 suites.
* Setting and getting 64bit packet numbers with of SAs.
* Setting (only on SA creation) and getting ssci of SAs.
* Setting salt when installing a SAK.

Added 2 cipher suite identifiers according to 802.1AE-2018 table 14-1:
* MACSEC_CIPHER_ID_GCM_AES_XPN_128
* MACSEC_CIPHER_ID_GCM_AES_XPN_256

In addition, added 2 new netlink attribute types:
* MACSEC_SA_ATTR_SSCI
* MACSEC_SA_ATTR_SALT

Depends on: macsec: Support XPN frame handling - IEEE 802.1AEbw.

Signed-off-by: Era Mayflower <mayflowerera@xxxxxxxxx>
---
drivers/net/macsec.c | 161 ++++++++++++++++++++++++++++++---
include/net/macsec.h | 3 +
include/uapi/linux/if_macsec.h | 8 +-
3 files changed, 157 insertions(+), 15 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index de9578daa..7083ee157 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -240,11 +240,13 @@ static struct macsec_cb *macsec_skb_cb(struct sk_buff *skb)
#define MACSEC_PORT_ES (htons(0x0001))
#define MACSEC_PORT_SCB (0x0000)
#define MACSEC_UNDEF_SCI ((__force sci_t)0xffffffffffffffffULL)
+#define MACSEC_UNDEF_SSCI ((__force ssci_t)0xffffffff)

#define MACSEC_GCM_AES_128_SAK_LEN 16
#define MACSEC_GCM_AES_256_SAK_LEN 32

#define DEFAULT_SAK_LEN MACSEC_GCM_AES_128_SAK_LEN
+#define DEFAULT_XPN false
#define DEFAULT_SEND_SCI true
#define DEFAULT_ENCRYPT false
#define DEFAULT_ENCODING_SA 0
@@ -1306,6 +1308,7 @@ static int init_rx_sa(struct macsec_rx_sa *rx_sa, char *sak, int key_len,
return PTR_ERR(rx_sa->key.tfm);
}

+ rx_sa->ssci = MACSEC_UNDEF_SSCI;
rx_sa->active = false;
rx_sa->next_pn = 1;
refcount_set(&rx_sa->refcnt, 1);
@@ -1404,6 +1407,7 @@ static int init_tx_sa(struct macsec_tx_sa *tx_sa, char *sak, int key_len,
return PTR_ERR(tx_sa->key.tfm);
}

+ tx_sa->ssci = MACSEC_UNDEF_SSCI;
tx_sa->active = false;
refcount_set(&tx_sa->refcnt, 1);
spin_lock_init(&tx_sa->lock);
@@ -1447,6 +1451,16 @@ static int nla_put_sci(struct sk_buff *skb, int attrtype, sci_t value,
return nla_put_u64_64bit(skb, attrtype, (__force u64)value, padattr);
}

+static ssci_t nla_get_ssci(const struct nlattr *nla)
+{
+ return (__force ssci_t)nla_get_u32(nla);
+}
+
+static int nla_put_ssci(struct sk_buff *skb, int attrtype, ssci_t value)
+{
+ return nla_put_u32(skb, attrtype, (__force u64)value);
+}
+
static struct macsec_tx_sa *get_txsa_from_nl(struct net *net,
struct nlattr **attrs,
struct nlattr **tb_sa,
@@ -1562,11 +1576,14 @@ static const struct nla_policy macsec_genl_rxsc_policy[NUM_MACSEC_RXSC_ATTR] = {
static const struct nla_policy macsec_genl_sa_policy[NUM_MACSEC_SA_ATTR] = {
[MACSEC_SA_ATTR_AN] = { .type = NLA_U8 },
[MACSEC_SA_ATTR_ACTIVE] = { .type = NLA_U8 },
- [MACSEC_SA_ATTR_PN] = { .type = NLA_U32 },
+ [MACSEC_SA_ATTR_PN] = { .type = NLA_MIN_LEN, .len = 4 },
[MACSEC_SA_ATTR_KEYID] = { .type = NLA_BINARY,
.len = MACSEC_KEYID_LEN, },
[MACSEC_SA_ATTR_KEY] = { .type = NLA_BINARY,
.len = MACSEC_MAX_KEY_LEN, },
+ [MACSEC_SA_ATTR_SSCI] = { .type = NLA_U32 },
+ [MACSEC_SA_ATTR_SALT] = { .type = NLA_BINARY,
+ .len = MACSEC_SALT_LEN, },
};

static const struct nla_policy macsec_genl_offload_policy[NUM_MACSEC_OFFLOAD_ATTR] = {
@@ -1639,7 +1656,8 @@ 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] && nla_get_u32(attrs[MACSEC_SA_ATTR_PN]) == 0)
+ if (attrs[MACSEC_SA_ATTR_PN] &&
+ *(u64 *)nla_data(attrs[MACSEC_SA_ATTR_PN]) == 0)
return false;

if (attrs[MACSEC_SA_ATTR_ACTIVE]) {
@@ -1661,6 +1679,7 @@ 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;
@@ -1693,6 +1712,29 @@ 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 (secy->xpn) {
+ if (!tb_sa[MACSEC_SA_ATTR_SSCI] || !tb_sa[MACSEC_SA_ATTR_SALT]) {
+ rtnl_unlock();
+ return -EINVAL;
+ }
+
+ if (nla_len(tb_sa[MACSEC_SA_ATTR_SALT]) != MACSEC_SALT_LEN) {
+ pr_notice("macsec: nl: add_rxsa: bad salt length: %d != %d\n",
+ nla_len(tb_sa[MACSEC_SA_ATTR_SALT]),
+ MACSEC_SA_ATTR_SALT);
+ rtnl_unlock();
+ return -EINVAL;
+ }
+ }
+
rx_sa = rtnl_dereference(rx_sc->sa[assoc_num]);
if (rx_sa) {
rtnl_unlock();
@@ -1715,7 +1757,7 @@ static int macsec_add_rxsa(struct sk_buff *skb, struct genl_info *info)

if (tb_sa[MACSEC_SA_ATTR_PN]) {
spin_lock_bh(&rx_sa->lock);
- rx_sa->next_pn_halves.lower = nla_get_u32(tb_sa[MACSEC_SA_ATTR_PN]);
+ rx_sa->next_pn = nla_get_u64(tb_sa[MACSEC_SA_ATTR_PN]);
spin_unlock_bh(&rx_sa->lock);
}

@@ -1745,6 +1787,12 @@ static int macsec_add_rxsa(struct sk_buff *skb, struct genl_info *info)
goto cleanup;
}

+ if (secy->xpn) {
+ rx_sa->ssci = nla_get_ssci(tb_sa[MACSEC_SA_ATTR_SSCI]);
+ nla_memcpy(rx_sa->key.salt.bytes, tb_sa[MACSEC_SA_ATTR_SALT],
+ MACSEC_SALT_LEN);
+ }
+
nla_memcpy(rx_sa->key.id, tb_sa[MACSEC_SA_ATTR_KEYID], MACSEC_KEYID_LEN);
rcu_assign_pointer(rx_sc->sa[assoc_num], rx_sa);

@@ -1869,6 +1917,7 @@ 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;
@@ -1901,6 +1950,29 @@ 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);
+ rtnl_unlock();
+ return -EINVAL;
+ }
+
+ if (secy->xpn) {
+ if (!tb_sa[MACSEC_SA_ATTR_SSCI] || !tb_sa[MACSEC_SA_ATTR_SALT]) {
+ rtnl_unlock();
+ return -EINVAL;
+ }
+
+ if (nla_len(tb_sa[MACSEC_SA_ATTR_SALT]) != MACSEC_SALT_LEN) {
+ pr_notice("macsec: nl: add_txsa: bad salt length: %d != %d\n",
+ nla_len(tb_sa[MACSEC_SA_ATTR_SALT]),
+ MACSEC_SA_ATTR_SALT);
+ rtnl_unlock();
+ return -EINVAL;
+ }
+ }
+
tx_sa = rtnl_dereference(tx_sc->sa[assoc_num]);
if (tx_sa) {
rtnl_unlock();
@@ -1922,7 +1994,7 @@ static int macsec_add_txsa(struct sk_buff *skb, struct genl_info *info)
}

spin_lock_bh(&tx_sa->lock);
- tx_sa->next_pn_halves.lower = nla_get_u32(tb_sa[MACSEC_SA_ATTR_PN]);
+ tx_sa->next_pn = nla_get_u64(tb_sa[MACSEC_SA_ATTR_PN]);
spin_unlock_bh(&tx_sa->lock);

if (tb_sa[MACSEC_SA_ATTR_ACTIVE])
@@ -1953,6 +2025,12 @@ static int macsec_add_txsa(struct sk_buff *skb, struct genl_info *info)
goto cleanup;
}

+ if (secy->xpn) {
+ tx_sa->ssci = nla_get_ssci(tb_sa[MACSEC_SA_ATTR_SSCI]);
+ nla_memcpy(tx_sa->key.salt.bytes, tb_sa[MACSEC_SA_ATTR_SALT],
+ MACSEC_SALT_LEN);
+ }
+
nla_memcpy(tx_sa->key.id, tb_sa[MACSEC_SA_ATTR_KEYID], MACSEC_KEYID_LEN);
rcu_assign_pointer(tx_sc->sa[assoc_num], tx_sa);

@@ -2159,7 +2237,9 @@ static bool validate_upd_sa(struct nlattr **attrs)
{
if (!attrs[MACSEC_SA_ATTR_AN] ||
attrs[MACSEC_SA_ATTR_KEY] ||
- attrs[MACSEC_SA_ATTR_KEYID])
+ attrs[MACSEC_SA_ATTR_KEYID] ||
+ attrs[MACSEC_SA_ATTR_SSCI] ||
+ attrs[MACSEC_SA_ATTR_SALT])
return false;

if (nla_get_u8(attrs[MACSEC_SA_ATTR_AN]) >= MACSEC_NUM_AN)
@@ -2209,9 +2289,19 @@ static int macsec_upd_txsa(struct sk_buff *skb, struct genl_info *info)
}

if (tb_sa[MACSEC_SA_ATTR_PN]) {
+ int pn_len;
+
+ 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);
+ rtnl_unlock();
+ return -EINVAL;
+ }
+
spin_lock_bh(&tx_sa->lock);
prev_pn = tx_sa->next_pn_halves;
- tx_sa->next_pn_halves.lower = nla_get_u32(tb_sa[MACSEC_SA_ATTR_PN]);
+ tx_sa->next_pn = nla_get_u64(tb_sa[MACSEC_SA_ATTR_PN]);
spin_unlock_bh(&tx_sa->lock);
}

@@ -2295,9 +2385,19 @@ static int macsec_upd_rxsa(struct sk_buff *skb, struct genl_info *info)
}

if (tb_sa[MACSEC_SA_ATTR_PN]) {
+ int pn_len;
+
+ 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);
+ rtnl_unlock();
+ return -EINVAL;
+ }
+
spin_lock_bh(&rx_sa->lock);
prev_pn = rx_sa->next_pn_halves;
- rx_sa->next_pn_halves.lower = nla_get_u32(tb_sa[MACSEC_SA_ATTR_PN]);
+ rx_sa->next_pn = nla_get_u64(tb_sa[MACSEC_SA_ATTR_PN]);
spin_unlock_bh(&rx_sa->lock);
}

@@ -2744,10 +2844,10 @@ static int nla_put_secy(struct macsec_secy *secy, struct sk_buff *skb)

switch (secy->key_len) {
case MACSEC_GCM_AES_128_SAK_LEN:
- csid = MACSEC_DEFAULT_CIPHER_ID;
+ csid = secy->xpn ? MACSEC_CIPHER_ID_GCM_AES_XPN_128 : MACSEC_DEFAULT_CIPHER_ID;
break;
case MACSEC_GCM_AES_256_SAK_LEN:
- csid = MACSEC_CIPHER_ID_GCM_AES_256;
+ csid = secy->xpn ? MACSEC_CIPHER_ID_GCM_AES_XPN_256 : MACSEC_CIPHER_ID_GCM_AES_256;
break;
default:
goto cancel;
@@ -2838,6 +2938,8 @@ dump_secy(struct macsec_secy *secy, struct net_device *dev,
for (i = 0, j = 1; i < MACSEC_NUM_AN; i++) {
struct macsec_tx_sa *tx_sa = rtnl_dereference(tx_sc->sa[i]);
struct nlattr *txsa_nest;
+ u64 pn;
+ int pn_len;

if (!tx_sa)
continue;
@@ -2848,9 +2950,18 @@ dump_secy(struct macsec_secy *secy, struct net_device *dev,
goto nla_put_failure;
}

+ if (secy->xpn) {
+ pn = tx_sa->next_pn;
+ pn_len = MACSEC_XPN_PN_LEN;
+ } else {
+ pn = tx_sa->next_pn_halves.lower;
+ pn_len = MACSEC_DEFAULT_PN_LEN;
+ }
+
if (nla_put_u8(skb, MACSEC_SA_ATTR_AN, i) ||
- nla_put_u32(skb, MACSEC_SA_ATTR_PN, tx_sa->next_pn_halves.lower) ||
+ nla_put(skb, MACSEC_SA_ATTR_PN, pn_len, &pn) ||
nla_put(skb, MACSEC_SA_ATTR_KEYID, MACSEC_KEYID_LEN, tx_sa->key.id) ||
+ (secy->xpn && nla_put_ssci(skb, MACSEC_SA_ATTR_SSCI, tx_sa->ssci)) ||
nla_put_u8(skb, MACSEC_SA_ATTR_ACTIVE, tx_sa->active)) {
nla_nest_cancel(skb, txsa_nest);
nla_nest_cancel(skb, txsa_list);
@@ -2923,6 +3034,8 @@ dump_secy(struct macsec_secy *secy, struct net_device *dev,
for (i = 0, k = 1; i < MACSEC_NUM_AN; i++) {
struct macsec_rx_sa *rx_sa = rtnl_dereference(rx_sc->sa[i]);
struct nlattr *rxsa_nest;
+ u64 pn;
+ int pn_len;

if (!rx_sa)
continue;
@@ -2952,9 +3065,18 @@ dump_secy(struct macsec_secy *secy, struct net_device *dev,
}
nla_nest_end(skb, attr);

+ if (secy->xpn) {
+ pn = rx_sa->next_pn;
+ pn_len = MACSEC_XPN_PN_LEN;
+ } else {
+ pn = rx_sa->next_pn_halves.lower;
+ pn_len = MACSEC_DEFAULT_PN_LEN;
+ }
+
if (nla_put_u8(skb, MACSEC_SA_ATTR_AN, i) ||
- nla_put_u32(skb, MACSEC_SA_ATTR_PN, rx_sa->next_pn_halves.lower) ||
+ nla_put(skb, MACSEC_SA_ATTR_PN, pn_len, &pn) ||
nla_put(skb, MACSEC_SA_ATTR_KEYID, MACSEC_KEYID_LEN, rx_sa->key.id) ||
+ (secy->xpn && nla_put_ssci(skb, MACSEC_SA_ATTR_SSCI, rx_sa->ssci)) ||
nla_put_u8(skb, MACSEC_SA_ATTR_ACTIVE, rx_sa->active)) {
nla_nest_cancel(skb, rxsa_nest);
nla_nest_cancel(skb, rxsc_nest);
@@ -3483,9 +3605,19 @@ static int macsec_changelink_common(struct net_device *dev,
case MACSEC_CIPHER_ID_GCM_AES_128:
case MACSEC_DEFAULT_CIPHER_ID:
secy->key_len = MACSEC_GCM_AES_128_SAK_LEN;
+ secy->xpn = false;
break;
case MACSEC_CIPHER_ID_GCM_AES_256:
secy->key_len = MACSEC_GCM_AES_256_SAK_LEN;
+ secy->xpn = false;
+ break;
+ case MACSEC_CIPHER_ID_GCM_AES_XPN_128:
+ secy->key_len = MACSEC_GCM_AES_128_SAK_LEN;
+ secy->xpn = true;
+ break;
+ case MACSEC_CIPHER_ID_GCM_AES_XPN_256:
+ secy->key_len = MACSEC_GCM_AES_256_SAK_LEN;
+ secy->xpn = true;
break;
default:
return -EINVAL;
@@ -3680,6 +3812,7 @@ static int macsec_add_dev(struct net_device *dev, sci_t sci, u8 icv_len)
secy->validate_frames = MACSEC_VALIDATE_DEFAULT;
secy->protect_frames = true;
secy->replay_protect = false;
+ secy->xpn = DEFAULT_XPN;

secy->sci = sci;
secy->tx_sc.active = true;
@@ -3809,6 +3942,8 @@ static int macsec_validate_attr(struct nlattr *tb[], struct nlattr *data[],
switch (csid) {
case MACSEC_CIPHER_ID_GCM_AES_128:
case MACSEC_CIPHER_ID_GCM_AES_256:
+ case MACSEC_CIPHER_ID_GCM_AES_XPN_128:
+ case MACSEC_CIPHER_ID_GCM_AES_XPN_256:
case MACSEC_DEFAULT_CIPHER_ID:
if (icv_len < MACSEC_MIN_ICV_LEN ||
icv_len > MACSEC_STD_ICV_LEN)
@@ -3882,10 +4017,10 @@ static int macsec_fill_info(struct sk_buff *skb,

switch (secy->key_len) {
case MACSEC_GCM_AES_128_SAK_LEN:
- csid = MACSEC_DEFAULT_CIPHER_ID;
+ csid = secy->xpn ? MACSEC_CIPHER_ID_GCM_AES_XPN_128 : MACSEC_DEFAULT_CIPHER_ID;
break;
case MACSEC_GCM_AES_256_SAK_LEN:
- csid = MACSEC_CIPHER_ID_GCM_AES_256;
+ csid = secy->xpn ? MACSEC_CIPHER_ID_GCM_AES_XPN_256 : MACSEC_CIPHER_ID_GCM_AES_256;
break;
default:
goto nla_put_failure;
diff --git a/include/net/macsec.h b/include/net/macsec.h
index 43cd54e17..2e4780dbf 100644
--- a/include/net/macsec.h
+++ b/include/net/macsec.h
@@ -11,6 +11,9 @@
#include <uapi/linux/if_link.h>
#include <uapi/linux/if_macsec.h>

+#define MACSEC_DEFAULT_PN_LEN 4
+#define MACSEC_XPN_PN_LEN 8
+
#define MACSEC_SALT_LEN 12
#define MACSEC_NUM_AN 4 /* 2 bits for the association number */

diff --git a/include/uapi/linux/if_macsec.h b/include/uapi/linux/if_macsec.h
index 1d63c43c3..3af2aa069 100644
--- a/include/uapi/linux/if_macsec.h
+++ b/include/uapi/linux/if_macsec.h
@@ -22,9 +22,11 @@

#define MACSEC_KEYID_LEN 16

-/* cipher IDs as per IEEE802.1AEbn-2011 */
+/* cipher IDs as per IEEE802.1AE-2018 (Table 14-1) */
#define MACSEC_CIPHER_ID_GCM_AES_128 0x0080C20001000001ULL
#define MACSEC_CIPHER_ID_GCM_AES_256 0x0080C20001000002ULL
+#define MACSEC_CIPHER_ID_GCM_AES_XPN_128 0x0080C20001000003ULL
+#define MACSEC_CIPHER_ID_GCM_AES_XPN_256 0x0080C20001000004ULL

/* deprecated cipher ID for GCM-AES-128 */
#define MACSEC_DEFAULT_CIPHER_ID 0x0080020001000001ULL
@@ -88,11 +90,13 @@ enum macsec_sa_attrs {
MACSEC_SA_ATTR_UNSPEC,
MACSEC_SA_ATTR_AN, /* config/dump, u8 0..3 */
MACSEC_SA_ATTR_ACTIVE, /* config/dump, u8 0..1 */
- MACSEC_SA_ATTR_PN, /* config/dump, u32 */
+ MACSEC_SA_ATTR_PN, /* config/dump, u32/u64 (u64 if XPN) */
MACSEC_SA_ATTR_KEY, /* config, data */
MACSEC_SA_ATTR_KEYID, /* config/dump, 128-bit */
MACSEC_SA_ATTR_STATS, /* dump, nested, macsec_sa_stats_attr */
MACSEC_SA_ATTR_PAD,
+ MACSEC_SA_ATTR_SSCI, /* config/dump, u32 - XPN only */
+ MACSEC_SA_ATTR_SALT, /* config, 96-bit - XPN only */
__MACSEC_SA_ATTR_END,
NUM_MACSEC_SA_ATTR = __MACSEC_SA_ATTR_END,
MACSEC_SA_ATTR_MAX = __MACSEC_SA_ATTR_END - 1,
--
2.20.1