netdevsim: add dummy macsec offload

When the kernel is compiled with MACsec support, add the
NETIF_F_HW_MACSEC feature to netdevsim devices and implement
macsec_ops.

To allow easy testing of failure from the device, support is limited
to 3 SecY's per netdevsim device, and 1 RXSC per SecY.

v2:
- nsim_macsec_add_secy, return -ENOSPC if secy_count isn't full but
we can't find an empty slot (Simon Horman)
- add sci_to_cpu to make sparse happy (Simon Horman)
- remove set but not used secy variable (kernel test robot and
Simon Horman)

Signed-off-by: Sabrina Dubroca <[e-mail]>
Reviewed-by: Simon Horman <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/netdevsim/Makefile

···
 ifneq ($(CONFIG_PSAMPLE),)
 netdevsim-objs += psample.o
 endif
+
+ifneq ($(CONFIG_MACSEC),)
+netdevsim-objs += macsec.o
+endif

drivers/net/netdevsim/macsec.c

···
+// SPDX-License-Identifier: GPL-2.0
+
+#include <net/macsec.h>
+#include "netdevsim.h"
+
+static inline u64 sci_to_cpu(sci_t sci)
+{
+	return be64_to_cpu((__force __be64)sci);
+}
+
+static int nsim_macsec_find_secy(struct netdevsim *ns, sci_t sci)
+{
+	int i;
+
+	for (i = 0; i < NSIM_MACSEC_MAX_SECY_COUNT; i++) {
+		if (ns->macsec.nsim_secy[i].sci == sci)
+			return i;
+	}
+
+	return -1;
+}
+
+static int nsim_macsec_find_rxsc(struct nsim_secy *ns_secy, sci_t sci)
+{
+	int i;
+
+	for (i = 0; i < NSIM_MACSEC_MAX_RXSC_COUNT; i++) {
+		if (ns_secy->nsim_rxsc[i].sci == sci)
+			return i;
+	}
+
+	return -1;
+}
+
+static int nsim_macsec_add_secy(struct macsec_context *ctx)
+{
+	struct netdevsim *ns = netdev_priv(ctx->netdev);
+	int idx;
+
+	if (ns->macsec.nsim_secy_count == NSIM_MACSEC_MAX_SECY_COUNT)
+		return -ENOSPC;
+
+	for (idx = 0; idx < NSIM_MACSEC_MAX_SECY_COUNT; idx++) {
+		if (!ns->macsec.nsim_secy[idx].used)
+			break;
+	}
+
+	if (idx == NSIM_MACSEC_MAX_SECY_COUNT) {
+		netdev_err(ctx->netdev, "%s: nsim_secy_count not full but all SecYs used\n",
+			   __func__);
+		return -ENOSPC;
+	}
+
+	netdev_dbg(ctx->netdev, "%s: adding new secy with sci %08llx at index %d\n",
+		   __func__, sci_to_cpu(ctx->secy->sci), idx);
+	ns->macsec.nsim_secy[idx].used = true;
+	ns->macsec.nsim_secy[idx].nsim_rxsc_count = 0;
+	ns->macsec.nsim_secy[idx].sci = ctx->secy->sci;
+	ns->macsec.nsim_secy_count++;
+
+	return 0;
+}
+
+static int nsim_macsec_upd_secy(struct macsec_context *ctx)
+{
+	struct netdevsim *ns = netdev_priv(ctx->netdev);
+	int idx;
+
+	idx = nsim_macsec_find_secy(ns, ctx->secy->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in secy table\n",
+			   __func__, sci_to_cpu(ctx->secy->sci));
+		return -ENOENT;
+	}
+
+	netdev_dbg(ctx->netdev, "%s: updating secy with sci %08llx at index %d\n",
+		   __func__, sci_to_cpu(ctx->secy->sci), idx);
+
+	return 0;
+}
+
+static int nsim_macsec_del_secy(struct macsec_context *ctx)
+{
+	struct netdevsim *ns = netdev_priv(ctx->netdev);
+	int idx;
+
+	idx = nsim_macsec_find_secy(ns, ctx->secy->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in secy table\n",
+			   __func__, sci_to_cpu(ctx->secy->sci));
+		return -ENOENT;
+	}
+
+	netdev_dbg(ctx->netdev, "%s: removing SecY with SCI %08llx at index %d\n",
+		   __func__, sci_to_cpu(ctx->secy->sci), idx);
+
+	ns->macsec.nsim_secy[idx].used = false;
+	memset(&ns->macsec.nsim_secy[idx], 0, sizeof(ns->macsec.nsim_secy[idx]));
+	ns->macsec.nsim_secy_count--;
+
+	return 0;
+}
+
+static int nsim_macsec_add_rxsc(struct macsec_context *ctx)
+{
+	struct netdevsim *ns = netdev_priv(ctx->netdev);
+	struct nsim_secy *secy;
+	int idx;
+
+	idx = nsim_macsec_find_secy(ns, ctx->secy->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in secy table\n",
+			   __func__, sci_to_cpu(ctx->secy->sci));
+		return -ENOENT;
+	}
+	secy = &ns->macsec.nsim_secy[idx];
+
+	if (secy->nsim_rxsc_count == NSIM_MACSEC_MAX_RXSC_COUNT)
+		return -ENOSPC;
+
+	for (idx = 0; idx < NSIM_MACSEC_MAX_RXSC_COUNT; idx++) {
+		if (!secy->nsim_rxsc[idx].used)
+			break;
+	}
+
+	if (idx == NSIM_MACSEC_MAX_RXSC_COUNT)
+		netdev_err(ctx->netdev, "%s: nsim_rxsc_count not full but all RXSCs used\n",
+			   __func__);
+
+	netdev_dbg(ctx->netdev, "%s: adding new rxsc with sci %08llx at index %d\n",
+		   __func__, sci_to_cpu(ctx->rx_sc->sci), idx);
+	secy->nsim_rxsc[idx].used = true;
+	secy->nsim_rxsc[idx].sci = ctx->rx_sc->sci;
+	secy->nsim_rxsc_count++;
+
+	return 0;
+}
+
+static int nsim_macsec_upd_rxsc(struct macsec_context *ctx)
+{
+	struct netdevsim *ns = netdev_priv(ctx->netdev);
+	struct nsim_secy *secy;
+	int idx;
+
+	idx = nsim_macsec_find_secy(ns, ctx->secy->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in secy table\n",
+			   __func__, sci_to_cpu(ctx->secy->sci));
+		return -ENOENT;
+	}
+	secy = &ns->macsec.nsim_secy[idx];
+
+	idx = nsim_macsec_find_rxsc(secy, ctx->rx_sc->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in RXSC table\n",
+			   __func__, sci_to_cpu(ctx->rx_sc->sci));
+		return -ENOENT;
+	}
+
+	netdev_dbg(ctx->netdev, "%s: updating RXSC with sci %08llx at index %d\n",
+		   __func__, sci_to_cpu(ctx->rx_sc->sci), idx);
+
+	return 0;
+}
+
+static int nsim_macsec_del_rxsc(struct macsec_context *ctx)
+{
+	struct netdevsim *ns = netdev_priv(ctx->netdev);
+	struct nsim_secy *secy;
+	int idx;
+
+	idx = nsim_macsec_find_secy(ns, ctx->secy->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in secy table\n",
+			   __func__, sci_to_cpu(ctx->secy->sci));
+		return -ENOENT;
+	}
+	secy = &ns->macsec.nsim_secy[idx];
+
+	idx = nsim_macsec_find_rxsc(secy, ctx->rx_sc->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in RXSC table\n",
+			   __func__, sci_to_cpu(ctx->rx_sc->sci));
+		return -ENOENT;
+	}
+
+	netdev_dbg(ctx->netdev, "%s: removing RXSC with sci %08llx at index %d\n",
+		   __func__, sci_to_cpu(ctx->rx_sc->sci), idx);
+
+	secy->nsim_rxsc[idx].used = false;
+	memset(&secy->nsim_rxsc[idx], 0, sizeof(secy->nsim_rxsc[idx]));
+	secy->nsim_rxsc_count--;
+
+	return 0;
+}
+
+static int nsim_macsec_add_rxsa(struct macsec_context *ctx)
+{
+	struct netdevsim *ns = netdev_priv(ctx->netdev);
+	struct nsim_secy *secy;
+	int idx;
+
+	idx = nsim_macsec_find_secy(ns, ctx->secy->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in secy table\n",
+			   __func__, sci_to_cpu(ctx->secy->sci));
+		return -ENOENT;
+	}
+	secy = &ns->macsec.nsim_secy[idx];
+
+	idx = nsim_macsec_find_rxsc(secy, ctx->sa.rx_sa->sc->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in RXSC table\n",
+			   __func__, sci_to_cpu(ctx->sa.rx_sa->sc->sci));
+		return -ENOENT;
+	}
+
+	netdev_dbg(ctx->netdev, "%s: RXSC with sci %08llx, AN %u\n",
+		   __func__, sci_to_cpu(ctx->sa.rx_sa->sc->sci), ctx->sa.assoc_num);
+
+	return 0;
+}
+
+static int nsim_macsec_upd_rxsa(struct macsec_context *ctx)
+{
+	struct netdevsim *ns = netdev_priv(ctx->netdev);
+	struct nsim_secy *secy;
+	int idx;
+
+	idx = nsim_macsec_find_secy(ns, ctx->secy->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in secy table\n",
+			   __func__, sci_to_cpu(ctx->secy->sci));
+		return -ENOENT;
+	}
+	secy = &ns->macsec.nsim_secy[idx];
+
+	idx = nsim_macsec_find_rxsc(secy, ctx->sa.rx_sa->sc->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in RXSC table\n",
+			   __func__, sci_to_cpu(ctx->sa.rx_sa->sc->sci));
+		return -ENOENT;
+	}
+
+	netdev_dbg(ctx->netdev, "%s: RXSC with sci %08llx, AN %u\n",
+		   __func__, sci_to_cpu(ctx->sa.rx_sa->sc->sci), ctx->sa.assoc_num);
+
+	return 0;
+}
+
+static int nsim_macsec_del_rxsa(struct macsec_context *ctx)
+{
+	struct netdevsim *ns = netdev_priv(ctx->netdev);
+	struct nsim_secy *secy;
+	int idx;
+
+	idx = nsim_macsec_find_secy(ns, ctx->secy->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in secy table\n",
+			   __func__, sci_to_cpu(ctx->secy->sci));
+		return -ENOENT;
+	}
+	secy = &ns->macsec.nsim_secy[idx];
+
+	idx = nsim_macsec_find_rxsc(secy, ctx->sa.rx_sa->sc->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in RXSC table\n",
+			   __func__, sci_to_cpu(ctx->sa.rx_sa->sc->sci));
+		return -ENOENT;
+	}
+
+	netdev_dbg(ctx->netdev, "%s: RXSC with sci %08llx, AN %u\n",
+		   __func__, sci_to_cpu(ctx->sa.rx_sa->sc->sci), ctx->sa.assoc_num);
+
+	return 0;
+}
+
+static int nsim_macsec_add_txsa(struct macsec_context *ctx)
+{
+	struct netdevsim *ns = netdev_priv(ctx->netdev);
+	int idx;
+
+	idx = nsim_macsec_find_secy(ns, ctx->secy->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in secy table\n",
+			   __func__, sci_to_cpu(ctx->secy->sci));
+		return -ENOENT;
+	}
+
+	netdev_dbg(ctx->netdev, "%s: SECY with sci %08llx, AN %u\n",
+		   __func__, sci_to_cpu(ctx->secy->sci), ctx->sa.assoc_num);
+
+	return 0;
+}
+
+static int nsim_macsec_upd_txsa(struct macsec_context *ctx)
+{
+	struct netdevsim *ns = netdev_priv(ctx->netdev);
+	int idx;
+
+	idx = nsim_macsec_find_secy(ns, ctx->secy->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in secy table\n",
+			   __func__, sci_to_cpu(ctx->secy->sci));
+		return -ENOENT;
+	}
+
+	netdev_dbg(ctx->netdev, "%s: SECY with sci %08llx, AN %u\n",
+		   __func__, sci_to_cpu(ctx->secy->sci), ctx->sa.assoc_num);
+
+	return 0;
+}
+
+static int nsim_macsec_del_txsa(struct macsec_context *ctx)
+{
+	struct netdevsim *ns = netdev_priv(ctx->netdev);
+	int idx;
+
+	idx = nsim_macsec_find_secy(ns, ctx->secy->sci);
+	if (idx < 0) {
+		netdev_err(ctx->netdev, "%s: sci %08llx not found in secy table\n",
+			   __func__, sci_to_cpu(ctx->secy->sci));
+		return -ENOENT;
+	}
+
+	netdev_dbg(ctx->netdev, "%s: SECY with sci %08llx, AN %u\n",
+		   __func__, sci_to_cpu(ctx->secy->sci), ctx->sa.assoc_num);
+
+	return 0;
+}
+
+static const struct macsec_ops nsim_macsec_ops = {
+	.mdo_add_secy = nsim_macsec_add_secy,
+	.mdo_upd_secy = nsim_macsec_upd_secy,
+	.mdo_del_secy = nsim_macsec_del_secy,
+	.mdo_add_rxsc = nsim_macsec_add_rxsc,
+	.mdo_upd_rxsc = nsim_macsec_upd_rxsc,
+	.mdo_del_rxsc = nsim_macsec_del_rxsc,
+	.mdo_add_rxsa = nsim_macsec_add_rxsa,
+	.mdo_upd_rxsa = nsim_macsec_upd_rxsa,
+	.mdo_del_rxsa = nsim_macsec_del_rxsa,
+	.mdo_add_txsa = nsim_macsec_add_txsa,
+	.mdo_upd_txsa = nsim_macsec_upd_txsa,
+	.mdo_del_txsa = nsim_macsec_del_txsa,
+};
+
+void nsim_macsec_init(struct netdevsim *ns)
+{
+	ns->netdev->macsec_ops = &nsim_macsec_ops;
+	ns->netdev->features |= NETIF_F_HW_MACSEC;
+	memset(&ns->macsec, 0, sizeof(ns->macsec));
+}
+
+void nsim_macsec_teardown(struct netdevsim *ns)
+{
+}

drivers/net/netdevsim/netdev.c

···
 	if (err)
 		goto err_utn_destroy;
 
+	nsim_macsec_init(ns);
 	nsim_ipsec_init(ns);
 
 	err = register_netdevice(ns->netdev);
···
 
 err_ipsec_teardown:
 	nsim_ipsec_teardown(ns);
+	nsim_macsec_teardown(ns);
 	nsim_bpf_uninit(ns);
 err_utn_destroy:
 	rtnl_unlock();
···
 	rtnl_lock();
 	unregister_netdevice(dev);
 	if (nsim_dev_port_is_pf(ns->nsim_dev_port)) {
+		nsim_macsec_teardown(ns);
 		nsim_ipsec_teardown(ns);
 		nsim_bpf_uninit(ns);
 	}

drivers/net/netdevsim/netdevsim.h

···
 #include <net/devlink.h>
 #include <net/udp_tunnel.h>
 #include <net/xdp.h>
+#include <net/macsec.h>
 
 #define DRV_NAME	"netdevsim"
 
···
 	u32 count;
 	u32 tx;
 	u32 ok;
+};
+
+#define NSIM_MACSEC_MAX_SECY_COUNT 3
+#define NSIM_MACSEC_MAX_RXSC_COUNT 1
+struct nsim_rxsc {
+	sci_t sci;
+	bool used;
+};
+
+struct nsim_secy {
+	sci_t sci;
+	struct nsim_rxsc nsim_rxsc[NSIM_MACSEC_MAX_RXSC_COUNT];
+	u8 nsim_rxsc_count;
+	bool used;
+};
+
+struct nsim_macsec {
+	struct nsim_secy nsim_secy[NSIM_MACSEC_MAX_SECY_COUNT];
+	u8 nsim_secy_count;
 };
 
 struct nsim_ethtool_pauseparam {
···
 
 	bool bpf_map_accept;
 	struct nsim_ipsec ipsec;
+	struct nsim_macsec macsec;
 	struct {
 		u32 inject_error;
 		u32 sleep;
···
 static inline bool nsim_ipsec_tx(struct netdevsim *ns, struct sk_buff *skb)
 {
 	return true;
+}
+#endif
+
+#if IS_ENABLED(CONFIG_MACSEC)
+void nsim_macsec_init(struct netdevsim *ns);
+void nsim_macsec_teardown(struct netdevsim *ns);
+#else
+static inline void nsim_macsec_init(struct netdevsim *ns)
+{
+}
+
+static inline void nsim_macsec_teardown(struct netdevsim *ns)
+{
 }
 #endif