// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * drivers/net/macsec.c - MACsec device
 *
 * Copyright (c) 2015 Sabrina Dubroca <sd@queasysnail.net>
 */

#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/module.h>
#include <crypto/aead.h>
#include <linux/etherdevice.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/refcount.h>
#include <net/genetlink.h>
#include <net/sock.h>
#include <net/gro_cells.h>
#include <net/macsec.h>
#include <linux/phy.h>
#include <linux/byteorder/generic.h>
#include <linux/if_arp.h>

#include <uapi/linux/if_macsec.h>

#define MACSEC_SCI_LEN 8

/* SecTAG length = macsec_eth_header without the optional SCI */
#define MACSEC_TAG_LEN 6

struct macsec_eth_header {
        struct ethhdr eth;
        /* SecTAG */
        u8  tci_an;
#if defined(__LITTLE_ENDIAN_BITFIELD)
        u8  short_length:6,
                  unused:2;
#elif defined(__BIG_ENDIAN_BITFIELD)
        u8        unused:2,
            short_length:6;
#else
#error  "Please fix <asm/byteorder.h>"
#endif
        __be32 packet_number;
        u8 secure_channel_id[8]; /* optional */
} __packed;

#define MACSEC_TCI_VERSION 0x80
#define MACSEC_TCI_ES      0x40 /* end station */
#define MACSEC_TCI_SC      0x20 /* SCI present */
#define MACSEC_TCI_SCB     0x10 /* epon */
#define MACSEC_TCI_E       0x08 /* encryption */
#define MACSEC_TCI_C       0x04 /* changed text */
#define MACSEC_AN_MASK     0x03 /* association number */
#define MACSEC_TCI_CONFID  (MACSEC_TCI_E | MACSEC_TCI_C)

/* minimum secure data length deemed "not short", see IEEE 802.1AE-2006 9.7 */
#define MIN_NON_SHORT_LEN 48

#define GCM_AES_IV_LEN 12
#define DEFAULT_ICV_LEN 16

#define for_each_rxsc(secy, sc)                         \
        for (sc = rcu_dereference_bh(secy->rx_sc);      \
             sc;                                        \
             sc = rcu_dereference_bh(sc->next))
#define for_each_rxsc_rtnl(secy, sc)                    \
        for (sc = rtnl_dereference(secy->rx_sc);        \
             sc;                                        \
             sc = rtnl_dereference(sc->next))

#define pn_same_half(pn1, pn2) (!(((pn1) >> 31) ^ ((pn2) >> 31)))

struct gcm_iv_xpn {
        union {
                u8 short_secure_channel_id[4];
                ssci_t ssci;
        };
        __be64 pn;
} __packed;

struct gcm_iv {
        union {
                u8 secure_channel_id[8];
                sci_t sci;
        };
        __be32 pn;
};

#define MACSEC_VALIDATE_DEFAULT MACSEC_VALIDATE_STRICT

struct pcpu_secy_stats {
        struct macsec_dev_stats stats;
        struct u64_stats_sync syncp;
};

/**
 * struct macsec_dev - private data
 * @secy: SecY config
 * @real_dev: pointer to underlying netdevice
 * @dev_tracker: refcount tracker for @real_dev reference
 * @stats: MACsec device stats
 * @secys: linked list of SecY's on the underlying device
 * @gro_cells: pointer to the Generic Receive Offload cell
 * @offload: status of offloading on the MACsec device
 */
struct macsec_dev {
        struct macsec_secy secy;
        struct net_device *real_dev;
        netdevice_tracker dev_tracker;
        struct pcpu_secy_stats __percpu *stats;
        struct list_head secys;
        struct gro_cells gro_cells;
        enum macsec_offload offload;
};

/**
 * struct macsec_rxh_data - rx_handler private argument
 * @secys: linked list of SecY's on this underlying device
 */
struct macsec_rxh_data {
        struct list_head secys;
};

static struct macsec_dev *macsec_priv(const struct net_device *dev)
{
        return (struct macsec_dev *)netdev_priv(dev);
}

static struct macsec_rxh_data *macsec_data_rcu(const struct net_device *dev)
{
        return rcu_dereference_bh(dev->rx_handler_data);
}

static struct macsec_rxh_data *macsec_data_rtnl(const struct net_device *dev)
{
        return rtnl_dereference(dev->rx_handler_data);
}

struct macsec_cb {
        struct aead_request *req;
        union {
                struct macsec_tx_sa *tx_sa;
                struct macsec_rx_sa *rx_sa;
        };
        u8 assoc_num;
        bool valid;
        bool has_sci;
};

static struct macsec_rx_sa *macsec_rxsa_get(struct macsec_rx_sa __rcu *ptr)
{
        struct macsec_rx_sa *sa = rcu_dereference_bh(ptr);

        if (!sa || !sa->active)
                return NULL;

        if (!refcount_inc_not_zero(&sa->refcnt))
                return NULL;

        return sa;
}

static struct macsec_rx_sa *macsec_active_rxsa_get(struct macsec_rx_sc *rx_sc)
{
        struct macsec_rx_sa *sa = NULL;
        int an;

        for (an = 0; an < MACSEC_NUM_AN; an++)  {
                sa = macsec_rxsa_get(rx_sc->sa[an]);
                if (sa)
                        break;
        }
        return sa;
}

static void free_rx_sc_rcu(struct rcu_head *head)
{
        struct macsec_rx_sc *rx_sc = container_of(head, struct macsec_rx_sc, rcu_head);

        free_percpu(rx_sc->stats);
        kfree(rx_sc);
}

static struct macsec_rx_sc *macsec_rxsc_get(struct macsec_rx_sc *sc)
{
        return refcount_inc_not_zero(&sc->refcnt) ? sc : NULL;
}

static void macsec_rxsc_put(struct macsec_rx_sc *sc)
{
        if (refcount_dec_and_test(&sc->refcnt))
                call_rcu(&sc->rcu_head, free_rx_sc_rcu);
}

static void free_rxsa(struct rcu_head *head)
{
        struct macsec_rx_sa *sa = container_of(head, struct macsec_rx_sa, rcu);

        crypto_free_aead(sa->key.tfm);
        free_percpu(sa->stats);
        kfree(sa);
}

static void macsec_rxsa_put(struct macsec_rx_sa *sa)
{
        if (refcount_dec_and_test(&sa->refcnt))
                call_rcu(&sa->rcu, free_rxsa);
}

static struct macsec_tx_sa *macsec_txsa_get(struct macsec_tx_sa __rcu *ptr)
{
        struct macsec_tx_sa *sa = rcu_dereference_bh(ptr);

        if (!sa || !sa->active)
                return NULL;

        if (!refcount_inc_not_zero(&sa->refcnt))
                return NULL;

        return sa;
}

static void free_txsa(struct rcu_head *head)
{
        struct macsec_tx_sa *sa = container_of(head, struct macsec_tx_sa, rcu);

        crypto_free_aead(sa->key.tfm);
        free_percpu(sa->stats);
        kfree(sa);
}

static void macsec_txsa_put(struct macsec_tx_sa *sa)
{
        if (refcount_dec_and_test(&sa->refcnt))
                call_rcu(&sa->rcu, free_txsa);
}

static struct macsec_cb *macsec_skb_cb(struct sk_buff *skb)
{
        BUILD_BUG_ON(sizeof(struct macsec_cb) > sizeof(skb->cb));
        return (struct macsec_cb *)skb->cb;
}

#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
#define MACSEC_XPN_MAX_REPLAY_WINDOW (((1 << 30) - 1))

static bool send_sci(const struct macsec_secy *secy)
{
        const struct macsec_tx_sc *tx_sc = &secy->tx_sc;

        return tx_sc->send_sci ||
                (secy->n_rx_sc > 1 && !tx_sc->end_station && !tx_sc->scb);
}

static sci_t make_sci(const u8 *addr, __be16 port)
{
        sci_t sci;

        memcpy(&sci, addr, ETH_ALEN);
        memcpy(((char *)&sci) + ETH_ALEN, &port, sizeof(port));

        return sci;
}

static sci_t macsec_frame_sci(struct macsec_eth_header *hdr, bool sci_present)
{
        sci_t sci;

        if (sci_present)
                memcpy(&sci, hdr->secure_channel_id,
                       sizeof(hdr->secure_channel_id));
        else
                sci = make_sci(hdr->eth.h_source, MACSEC_PORT_ES);

        return sci;
}

static unsigned int macsec_sectag_len(bool sci_present)
{
        return MACSEC_TAG_LEN + (sci_present ? MACSEC_SCI_LEN : 0);
}

static unsigned int macsec_hdr_len(bool sci_present)
{
        return macsec_sectag_len(sci_present) + ETH_HLEN;
}

static unsigned int macsec_extra_len(bool sci_present)
{
        return macsec_sectag_len(sci_present) + sizeof(__be16);
}

/* Fill SecTAG according to IEEE 802.1AE-2006 10.5.3 */
static void macsec_fill_sectag(struct macsec_eth_header *h,
                               const struct macsec_secy *secy, u32 pn,
                               bool sci_present)
{
        const struct macsec_tx_sc *tx_sc = &secy->tx_sc;

        memset(&h->tci_an, 0, macsec_sectag_len(sci_present));
        h->eth.h_proto = htons(ETH_P_MACSEC);

        if (sci_present) {
                h->tci_an |= MACSEC_TCI_SC;
                memcpy(&h->secure_channel_id, &secy->sci,
                       sizeof(h->secure_channel_id));
        } else {
                if (tx_sc->end_station)
                        h->tci_an |= MACSEC_TCI_ES;
                if (tx_sc->scb)
                        h->tci_an |= MACSEC_TCI_SCB;
        }

        h->packet_number = htonl(pn);

        /* with GCM, C/E clear for !encrypt, both set for encrypt */
        if (tx_sc->encrypt)
                h->tci_an |= MACSEC_TCI_CONFID;
        else if (secy->icv_len != DEFAULT_ICV_LEN)
                h->tci_an |= MACSEC_TCI_C;

        h->tci_an |= tx_sc->encoding_sa;
}

static void macsec_set_shortlen(struct macsec_eth_header *h, size_t data_len)
{
        if (data_len < MIN_NON_SHORT_LEN)
                h->short_length = data_len;
}

/* Checks if a MACsec interface is being offloaded to an hardware engine */
static bool macsec_is_offloaded(struct macsec_dev *macsec)
{
        if (macsec->offload == MACSEC_OFFLOAD_MAC ||
            macsec->offload == MACSEC_OFFLOAD_PHY)
                return true;

        return false;
}

/* Checks if underlying layers implement MACsec offloading functions. */
static bool macsec_check_offload(enum macsec_offload offload,
                                 struct macsec_dev *macsec)
{
        if (!macsec || !macsec->real_dev)
                return false;

        if (offload == MACSEC_OFFLOAD_PHY)
                return macsec->real_dev->phydev &&
                       macsec->real_dev->phydev->macsec_ops;
        else if (offload == MACSEC_OFFLOAD_MAC)
                return macsec->real_dev->features & NETIF_F_HW_MACSEC &&
                       macsec->real_dev->macsec_ops;

        return false;
}

static const struct macsec_ops *__macsec_get_ops(enum macsec_offload offload,
                                                 struct macsec_dev *macsec,
                                                 struct macsec_context *ctx)
{
        if (ctx) {
                memset(ctx, 0, sizeof(*ctx));
                ctx->offload = offload;

                if (offload == MACSEC_OFFLOAD_PHY)
                        ctx->phydev = macsec->real_dev->phydev;
                else if (offload == MACSEC_OFFLOAD_MAC)
                        ctx->netdev = macsec->real_dev;
        }

        if (offload == MACSEC_OFFLOAD_PHY)
                return macsec->real_dev->phydev->macsec_ops;
        else
                return macsec->real_dev->macsec_ops;
}

/* Returns a pointer to the MACsec ops struct if any and updates the MACsec
 * context device reference if provided.
 */
static const struct macsec_ops *macsec_get_ops(struct macsec_dev *macsec,
                                               struct macsec_context *ctx)
{
        if (!macsec_check_offload(macsec->offload, macsec))
                return NULL;

        return __macsec_get_ops(macsec->offload, macsec, ctx);
}

/* validate MACsec packet according to IEEE 802.1AE-2018 9.12 */
static bool macsec_validate_skb(struct sk_buff *skb, u16 icv_len, bool xpn)
{
        struct macsec_eth_header *h = (struct macsec_eth_header *)skb->data;
        int len = skb->len - 2 * ETH_ALEN;
        int extra_len = macsec_extra_len(!!(h->tci_an & MACSEC_TCI_SC)) + icv_len;

        /* a) It comprises at least 17 octets */
        if (skb->len <= 16)
                return false;

        /* b) MACsec EtherType: already checked */

        /* c) V bit is clear */
        if (h->tci_an & MACSEC_TCI_VERSION)
                return false;

        /* d) ES or SCB => !SC */
        if ((h->tci_an & MACSEC_TCI_ES || h->tci_an & MACSEC_TCI_SCB) &&
            (h->tci_an & MACSEC_TCI_SC))
                return false;

        /* e) Bits 7 and 8 of octet 4 of the SecTAG are clear */
        if (h->unused)
                return false;

        /* rx.pn != 0 if not XPN (figure 10-5 with 802.11AEbw-2013 amendment) */
        if (!h->packet_number && !xpn)
                return false;

        /* length check, f) g) h) i) */
        if (h->short_length)
                return len == extra_len + h->short_length;
        return len >= extra_len + MIN_NON_SHORT_LEN;
}

#define MACSEC_NEEDED_HEADROOM (macsec_extra_len(true))
#define MACSEC_NEEDED_TAILROOM MACSEC_STD_ICV_LEN

static void macsec_fill_iv_xpn(unsigned char *iv, ssci_t ssci, u64 pn,
                               salt_t salt)
{
        struct gcm_iv_xpn *gcm_iv = (struct gcm_iv_xpn *)iv;

        gcm_iv->ssci = ssci ^ salt.ssci;
        gcm_iv->pn = cpu_to_be64(pn) ^ salt.pn;
}

static void macsec_fill_iv(unsigned char *iv, sci_t sci, u32 pn)
{
        struct gcm_iv *gcm_iv = (struct gcm_iv *)iv;

        gcm_iv->sci = sci;
        gcm_iv->pn = htonl(pn);
}

static struct macsec_eth_header *macsec_ethhdr(struct sk_buff *skb)
{
        return (struct macsec_eth_header *)skb_mac_header(skb);
}

static void __macsec_pn_wrapped(struct macsec_secy *secy,
                                struct macsec_tx_sa *tx_sa)
{
        pr_debug("PN wrapped, transitioning to !oper\n");
        tx_sa->active = false;
        if (secy->protect_frames)
                secy->operational = false;
}

void macsec_pn_wrapped(struct macsec_secy *secy, struct macsec_tx_sa *tx_sa)
{
        spin_lock_bh(&tx_sa->lock);
        __macsec_pn_wrapped(secy, tx_sa);
        spin_unlock_bh(&tx_sa->lock);
}
EXPORT_SYMBOL_GPL(macsec_pn_wrapped);

static pn_t tx_sa_update_pn(struct macsec_tx_sa *tx_sa,
                            struct macsec_secy *secy)
{
        pn_t pn;

        spin_lock_bh(&tx_sa->lock);

        pn = tx_sa->next_pn_halves;
        if (secy->xpn)
                tx_sa->next_pn++;
        else
                tx_sa->next_pn_halves.lower++;

        if (tx_sa->next_pn == 0)
                __macsec_pn_wrapped(secy, tx_sa);
        spin_unlock_bh(&tx_sa->lock);

        return pn;
}

static void macsec_encrypt_finish(struct sk_buff *skb, struct net_device *dev)
{
        struct macsec_dev *macsec = netdev_priv(dev);

        skb->dev = macsec->real_dev;
        skb_reset_mac_header(skb);
        skb->protocol = eth_hdr(skb)->h_proto;
}

static unsigned int macsec_msdu_len(struct sk_buff *skb)
{
        struct macsec_dev *macsec = macsec_priv(skb->dev);
        struct macsec_secy *secy = &macsec->secy;
        bool sci_present = macsec_skb_cb(skb)->has_sci;

        return skb->len - macsec_hdr_len(sci_present) - secy->icv_len;
}

static void macsec_count_tx(struct sk_buff *skb, struct macsec_tx_sc *tx_sc,
                            struct macsec_tx_sa *tx_sa)
{
        unsigned int msdu_len = macsec_msdu_len(skb);
        struct pcpu_tx_sc_stats *txsc_stats = this_cpu_ptr(tx_sc->stats);

        u64_stats_update_begin(&txsc_stats->syncp);
        if (tx_sc->encrypt) {
                txsc_stats->stats.OutOctetsEncrypted += msdu_len;
                txsc_stats->stats.OutPktsEncrypted++;
                this_cpu_inc(tx_sa->stats->OutPktsEncrypted);
        } else {
                txsc_stats->stats.OutOctetsProtected += msdu_len;
                txsc_stats->stats.OutPktsProtected++;
                this_cpu_inc(tx_sa->stats->OutPktsProtected);
        }
        u64_stats_update_end(&txsc_stats->syncp);
}

static void count_tx(struct net_device *dev, int ret, int len)
{
        if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
                struct pcpu_sw_netstats *stats = this_cpu_ptr(dev->tstats);

                u64_stats_update_begin(&stats->syncp);
                u64_stats_inc(&stats->tx_packets);
                u64_stats_add(&stats->tx_bytes, len);
                u64_stats_update_end(&stats->syncp);
        }
}

static void macsec_encrypt_done(struct crypto_async_request *base, int err)
{
        struct sk_buff *skb = base->data;
        struct net_device *dev = skb->dev;
        struct macsec_dev *macsec = macsec_priv(dev);
        struct macsec_tx_sa *sa = macsec_skb_cb(skb)->tx_sa;
        int len, ret;

        aead_request_free(macsec_skb_cb(skb)->req);

        rcu_read_lock_bh();
        macsec_count_tx(skb, &macsec->secy.tx_sc, macsec_skb_cb(skb)->tx_sa);
        /* packet is encrypted/protected so tx_bytes must be calculated */
        len = macsec_msdu_len(skb) + 2 * ETH_ALEN;
        macsec_encrypt_finish(skb, dev);
        ret = dev_queue_xmit(skb);
        count_tx(dev, ret, len);
        rcu_read_unlock_bh();

        macsec_txsa_put(sa);
        dev_put(dev);
}

static struct aead_request *macsec_alloc_req(struct crypto_aead *tfm,
                                             unsigned char **iv,
                                             struct scatterlist **sg,
                                             int num_frags)
{
        size_t size, iv_offset, sg_offset;
        struct aead_request *req;
        void *tmp;

        size = sizeof(struct aead_request) + crypto_aead_reqsize(tfm);
        iv_offset = size;
        size += GCM_AES_IV_LEN;

        size = ALIGN(size, __alignof__(struct scatterlist));
        sg_offset = size;
        size += sizeof(struct scatterlist) * num_frags;

        tmp = kmalloc(size, GFP_ATOMIC);
        if (!tmp)
                return NULL;

        *iv = (unsigned char *)(tmp + iv_offset);
        *sg = (struct scatterlist *)(tmp + sg_offset);
        req = tmp;

        aead_request_set_tfm(req, tfm);

        return req;
}

static struct sk_buff *macsec_encrypt(struct sk_buff *skb,
                                      struct net_device *dev)
{
        int ret;
        struct scatterlist *sg;
        struct sk_buff *trailer;
        unsigned char *iv;
        struct ethhdr *eth;
        struct macsec_eth_header *hh;
        size_t unprotected_len;
        struct aead_request *req;
        struct macsec_secy *secy;
        struct macsec_tx_sc *tx_sc;
        struct macsec_tx_sa *tx_sa;
        struct macsec_dev *macsec = macsec_priv(dev);
        bool sci_present;
        pn_t pn;

        secy = &macsec->secy;
        tx_sc = &secy->tx_sc;

        /* 10.5.1 TX SA assignment */
        tx_sa = macsec_txsa_get(tx_sc->sa[tx_sc->encoding_sa]);
        if (!tx_sa) {
                secy->operational = false;
                kfree_skb(skb);
                return ERR_PTR(-EINVAL);
        }

        if (unlikely(skb_headroom(skb) < MACSEC_NEEDED_HEADROOM ||
                     skb_tailroom(skb) < MACSEC_NEEDED_TAILROOM)) {
                struct sk_buff *nskb = skb_copy_expand(skb,
                                                       MACSEC_NEEDED_HEADROOM,
                                                       MACSEC_NEEDED_TAILROOM,
                                                       GFP_ATOMIC);
                if (likely(nskb)) {
                        consume_skb(skb);
                        skb = nskb;
                } else {
                        macsec_txsa_put(tx_sa);
                        kfree_skb(skb);
                        return ERR_PTR(-ENOMEM);
                }
        } else {
                skb = skb_unshare(skb, GFP_ATOMIC);
                if (!skb) {
                        macsec_txsa_put(tx_sa);
                        return ERR_PTR(-ENOMEM);
                }
        }

        unprotected_len = skb->len;
        eth = eth_hdr(skb);
        sci_present = send_sci(secy);
        hh = skb_push(skb, macsec_extra_len(sci_present));
        memmove(hh, eth, 2 * ETH_ALEN);

        pn = tx_sa_update_pn(tx_sa, secy);
        if (pn.full64 == 0) {
                macsec_txsa_put(tx_sa);
                kfree_skb(skb);
                return ERR_PTR(-ENOLINK);
        }
        macsec_fill_sectag(hh, secy, pn.lower, sci_present);
        macsec_set_shortlen(hh, unprotected_len - 2 * ETH_ALEN);

        skb_put(skb, secy->icv_len);

        if (skb->len - ETH_HLEN > macsec_priv(dev)->real_dev->mtu) {
                struct pcpu_secy_stats *secy_stats = this_cpu_ptr(macsec->stats);

                u64_stats_update_begin(&secy_stats->syncp);
                secy_stats->stats.OutPktsTooLong++;
                u64_stats_update_end(&secy_stats->syncp);

                macsec_txsa_put(tx_sa);
                kfree_skb(skb);
                return ERR_PTR(-EINVAL);
        }

        ret = skb_cow_data(skb, 0, &trailer);
        if (unlikely(ret < 0)) {
                macsec_txsa_put(tx_sa);
                kfree_skb(skb);
                return ERR_PTR(ret);
        }

        req = macsec_alloc_req(tx_sa->key.tfm, &iv, &sg, ret);
        if (!req) {
                macsec_txsa_put(tx_sa);
                kfree_skb(skb);
                return ERR_PTR(-ENOMEM);
        }

        if (secy->xpn)
                macsec_fill_iv_xpn(iv, tx_sa->ssci, pn.full64, tx_sa->key.salt);
        else
                macsec_fill_iv(iv, secy->sci, pn.lower);

        sg_init_table(sg, ret);
        ret = skb_to_sgvec(skb, sg, 0, skb->len);
        if (unlikely(ret < 0)) {
                aead_request_free(req);
                macsec_txsa_put(tx_sa);
                kfree_skb(skb);
                return ERR_PTR(ret);
        }

        if (tx_sc->encrypt) {
                int len = skb->len - macsec_hdr_len(sci_present) -
                          secy->icv_len;
                aead_request_set_crypt(req, sg, sg, len, iv);
                aead_request_set_ad(req, macsec_hdr_len(sci_present));
        } else {
                aead_request_set_crypt(req, sg, sg, 0, iv);
                aead_request_set_ad(req, skb->len - secy->icv_len);
        }

        macsec_skb_cb(skb)->req = req;
        macsec_skb_cb(skb)->tx_sa = tx_sa;
        macsec_skb_cb(skb)->has_sci = sci_present;
        aead_request_set_callback(req, 0, macsec_encrypt_done, skb);

        dev_hold(skb->dev);
        ret = crypto_aead_encrypt(req);
        if (ret == -EINPROGRESS) {
                return ERR_PTR(ret);
        } else if (ret != 0) {
                dev_put(skb->dev);
                kfree_skb(skb);
                aead_request_free(req);
                macsec_txsa_put(tx_sa);
                return ERR_PTR(-EINVAL);
        }

        dev_put(skb->dev);
        aead_request_free(req);
        macsec_txsa_put(tx_sa);

        return skb;
}

static bool macsec_post_decrypt(struct sk_buff *skb, struct macsec_secy *secy, u32 pn)
{
        struct macsec_rx_sa *rx_sa = macsec_skb_cb(skb)->rx_sa;
        struct pcpu_rx_sc_stats *rxsc_stats = this_cpu_ptr(rx_sa->sc->stats);
        struct macsec_eth_header *hdr = macsec_ethhdr(skb);
        u32 lowest_pn = 0;

        spin_lock(&rx_sa->lock);
        if (rx_sa->next_pn_halves.lower >= secy->replay_window)
                lowest_pn = rx_sa->next_pn_halves.lower - secy->replay_window;

        /* Now perform replay protection check again
         * (see IEEE 802.1AE-2006 figure 10-5)
         */
        if (secy->replay_protect && pn < lowest_pn &&
            (!secy->xpn || pn_same_half(pn, lowest_pn))) {
                spin_unlock(&rx_sa->lock);
                u64_stats_update_begin(&rxsc_stats->syncp);
                rxsc_stats->stats.InPktsLate++;
                u64_stats_update_end(&rxsc_stats->syncp);
                secy->netdev->stats.rx_dropped++;
                return false;
        }

        if (secy->validate_frames != MACSEC_VALIDATE_DISABLED) {
                unsigned int msdu_len = macsec_msdu_len(skb);
                u64_stats_update_begin(&rxsc_stats->syncp);
                if (hdr->tci_an & MACSEC_TCI_E)
                        rxsc_stats->stats.InOctetsDecrypted += msdu_len;
                else
                        rxsc_stats->stats.InOctetsValidated += msdu_len;
                u64_stats_update_end(&rxsc_stats->syncp);
        }

        if (!macsec_skb_cb(skb)->valid) {
                spin_unlock(&rx_sa->lock);

                /* 10.6.5 */
                if (hdr->tci_an & MACSEC_TCI_C ||
                    secy->validate_frames == MACSEC_VALIDATE_STRICT) {
                        u64_stats_update_begin(&rxsc_stats->syncp);
                        rxsc_stats->stats.InPktsNotValid++;
                        u64_stats_update_end(&rxsc_stats->syncp);
                        this_cpu_inc(rx_sa->stats->InPktsNotValid);
                        secy->netdev->stats.rx_errors++;
                        return false;
                }

                u64_stats_update_begin(&rxsc_stats->syncp);
                if (secy->validate_frames == MACSEC_VALIDATE_CHECK) {
                        rxsc_stats->stats.InPktsInvalid++;
                        this_cpu_inc(rx_sa->stats->InPktsInvalid);
                } else if (pn < lowest_pn) {
                        rxsc_stats->stats.InPktsDelayed++;
                } else {
                        rxsc_stats->stats.InPktsUnchecked++;
                }
                u64_stats_update_end(&rxsc_stats->syncp);
        } else {
                u64_stats_update_begin(&rxsc_stats->syncp);
                if (pn < lowest_pn) {
                        rxsc_stats->stats.InPktsDelayed++;
                } else {
                        rxsc_stats->stats.InPktsOK++;
                        this_cpu_inc(rx_sa->stats->InPktsOK);
                }
                u64_stats_update_end(&rxsc_stats->syncp);

                // Instead of "pn >=" - to support pn overflow in xpn
                if (pn + 1 > rx_sa->next_pn_halves.lower) {
                        rx_sa->next_pn_halves.lower = pn + 1;
                } else if (secy->xpn &&
                           !pn_same_half(pn, rx_sa->next_pn_halves.lower)) {
                        rx_sa->next_pn_halves.upper++;
                        rx_sa->next_pn_halves.lower = pn + 1;
                }

                spin_unlock(&rx_sa->lock);
        }

        return true;
}

static void macsec_reset_skb(struct sk_buff *skb, struct net_device *dev)
{
        skb->pkt_type = PACKET_HOST;
        skb->protocol = eth_type_trans(skb, dev);

        skb_reset_network_header(skb);
        if (!skb_transport_header_was_set(skb))
                skb_reset_transport_header(skb);
        skb_reset_mac_len(skb);
}

static void macsec_finalize_skb(struct sk_buff *skb, u8 icv_len, u8 hdr_len)
{
        skb->ip_summed = CHECKSUM_NONE;
        memmove(skb->data + hdr_len, skb->data, 2 * ETH_ALEN);
        skb_pull(skb, hdr_len);
        pskb_trim_unique(skb, skb->len - icv_len);
}

static void count_rx(struct net_device *dev, int len)
{
        struct pcpu_sw_netstats *stats = this_cpu_ptr(dev->tstats);

        u64_stats_update_begin(&stats->syncp);
        u64_stats_inc(&stats->rx_packets);
        u64_stats_add(&stats->rx_bytes, len);
        u64_stats_update_end(&stats->syncp);
}

static void macsec_decrypt_done(struct crypto_async_request *base, int err)
{
        struct sk_buff *skb = base->data;
        struct net_device *dev = skb->dev;
        struct macsec_dev *macsec = macsec_priv(dev);
        struct macsec_rx_sa *rx_sa = macsec_skb_cb(skb)->rx_sa;
        struct macsec_rx_sc *rx_sc = rx_sa->sc;
        int len;
        u32 pn;

        aead_request_free(macsec_skb_cb(skb)->req);

        if (!err)
                macsec_skb_cb(skb)->valid = true;

        rcu_read_lock_bh();
        pn = ntohl(macsec_ethhdr(skb)->packet_number);
        if (!macsec_post_decrypt(skb, &macsec->secy, pn)) {
                rcu_read_unlock_bh();
                kfree_skb(skb);
                goto out;
        }

        macsec_finalize_skb(skb, macsec->secy.icv_len,
                            macsec_extra_len(macsec_skb_cb(skb)->has_sci));
        len = skb->len;
        macsec_reset_skb(skb, macsec->secy.netdev);

        if (gro_cells_receive(&macsec->gro_cells, skb) == NET_RX_SUCCESS)
                count_rx(dev, len);

        rcu_read_unlock_bh();

out:
        macsec_rxsa_put(rx_sa);
        macsec_rxsc_put(rx_sc);
        dev_put(dev);
}

static struct sk_buff *macsec_decrypt(struct sk_buff *skb,
                                      struct net_device *dev,
                                      struct macsec_rx_sa *rx_sa,
                                      sci_t sci,
                                      struct macsec_secy *secy)
{
        int ret;
        struct scatterlist *sg;
        struct sk_buff *trailer;
        unsigned char *iv;
        struct aead_request *req;
        struct macsec_eth_header *hdr;
        u32 hdr_pn;
        u16 icv_len = secy->icv_len;

        macsec_skb_cb(skb)->valid = false;
        skb = skb_share_check(skb, GFP_ATOMIC);
        if (!skb)
                return ERR_PTR(-ENOMEM);

        ret = skb_cow_data(skb, 0, &trailer);
        if (unlikely(ret < 0)) {
                kfree_skb(skb);
                return ERR_PTR(ret);
        }
        req = macsec_alloc_req(rx_sa->key.tfm, &iv, &sg, ret);
        if (!req) {
                kfree_skb(skb);
                return ERR_PTR(-ENOMEM);
        }

        hdr = (struct macsec_eth_header *)skb->data;
        hdr_pn = ntohl(hdr->packet_number);

        if (secy->xpn) {
                pn_t recovered_pn = rx_sa->next_pn_halves;

                recovered_pn.lower = hdr_pn;
                if (hdr_pn < rx_sa->next_pn_halves.lower &&
                    !pn_same_half(hdr_pn, rx_sa->next_pn_halves.lower))
                        recovered_pn.upper++;

                macsec_fill_iv_xpn(iv, rx_sa->ssci, recovered_pn.full64,
                                   rx_sa->key.salt);
        } else {
                macsec_fill_iv(iv, sci, hdr_pn);
        }

        sg_init_table(sg, ret);
        ret = skb_to_sgvec(skb, sg, 0, skb->len);
        if (unlikely(ret < 0)) {
                aead_request_free(req);
                kfree_skb(skb);
                return ERR_PTR(ret);
        }

        if (hdr->tci_an & MACSEC_TCI_E) {
                /* confidentiality: ethernet + macsec header
                 * authenticated, encrypted payload
                 */
                int len = skb->len - macsec_hdr_len(macsec_skb_cb(skb)->has_sci);

                aead_request_set_crypt(req, sg, sg, len, iv);
                aead_request_set_ad(req, macsec_hdr_len(macsec_skb_cb(skb)->has_sci));
                skb = skb_unshare(skb, GFP_ATOMIC);
                if (!skb) {
                        aead_request_free(req);
                        return ERR_PTR(-ENOMEM);
                }
        } else {
                /* integrity only: all headers + data authenticated */
                aead_request_set_crypt(req, sg, sg, icv_len, iv);
                aead_request_set_ad(req, skb->len - icv_len);
        }

        macsec_skb_cb(skb)->req = req;
        skb->dev = dev;
        aead_request_set_callback(req, 0, macsec_decrypt_done, skb);

        dev_hold(dev);
        ret = crypto_aead_decrypt(req);
        if (ret == -EINPROGRESS) {
                return ERR_PTR(ret);
        } else if (ret != 0) {
                /* decryption/authentication failed
                 * 10.6 if validateFrames is disabled, deliver anyway
                 */
                if (ret != -EBADMSG) {
                        kfree_skb(skb);
                        skb = ERR_PTR(ret);
                }
        } else {
                macsec_skb_cb(skb)->valid = true;
        }
        dev_put(dev);

        aead_request_free(req);

        return skb;
}

static struct macsec_rx_sc *find_rx_sc(struct macsec_secy *secy, sci_t sci)
{
        struct macsec_rx_sc *rx_sc;

        for_each_rxsc(secy, rx_sc) {
                if (rx_sc->sci == sci)
                        return rx_sc;
        }

        return NULL;
}

static struct macsec_rx_sc *find_rx_sc_rtnl(struct macsec_secy *secy, sci_t sci)
{
        struct macsec_rx_sc *rx_sc;

        for_each_rxsc_rtnl(secy, rx_sc) {
                if (rx_sc->sci == sci)
                        return rx_sc;
        }

        return NULL;
}

static enum rx_handler_result handle_not_macsec(struct sk_buff *skb)
{
        /* Deliver to the uncontrolled port by default */
        enum rx_handler_result ret = RX_HANDLER_PASS;
        struct ethhdr *hdr = eth_hdr(skb);
        struct macsec_rxh_data *rxd;
        struct macsec_dev *macsec;

        rcu_read_lock();
        rxd = macsec_data_rcu(skb->dev);

        list_for_each_entry_rcu(macsec, &rxd->secys, secys) {
                struct sk_buff *nskb;
                struct pcpu_secy_stats *secy_stats = this_cpu_ptr(macsec->stats);
                struct net_device *ndev = macsec->secy.netdev;

                /* If h/w offloading is enabled, HW decodes frames and strips
                 * the SecTAG, so we have to deduce which port to deliver to.
                 */
                if (macsec_is_offloaded(macsec) && netif_running(ndev)) {
                        if (ether_addr_equal_64bits(hdr->h_dest,
                                                    ndev->dev_addr)) {
                                /* exact match, divert skb to this port */
                                skb->dev = ndev;
                                skb->pkt_type = PACKET_HOST;
                                ret = RX_HANDLER_ANOTHER;
                                goto out;
                        } else if (is_multicast_ether_addr_64bits(
                                           hdr->h_dest)) {
                                /* multicast frame, deliver on this port too */
                                nskb = skb_clone(skb, GFP_ATOMIC);
                                if (!nskb)
                                        break;

                                nskb->dev = ndev;
                                if (ether_addr_equal_64bits(hdr->h_dest,
                                                            ndev->broadcast))
                                        nskb->pkt_type = PACKET_BROADCAST;
                                else
                                        nskb->pkt_type = PACKET_MULTICAST;

                                __netif_rx(nskb);
                        }
                        continue;
                }

                /* 10.6 If the management control validateFrames is not
                 * Strict, frames without a SecTAG are received, counted, and
                 * delivered to the Controlled Port
                 */
                if (macsec->secy.validate_frames == MACSEC_VALIDATE_STRICT) {
                        u64_stats_update_begin(&secy_stats->syncp);
                        secy_stats->stats.InPktsNoTag++;
                        u64_stats_update_end(&secy_stats->syncp);
                        macsec->secy.netdev->stats.rx_dropped++;
                        continue;
                }

                /* deliver on this port */
                nskb = skb_clone(skb, GFP_ATOMIC);
                if (!nskb)
                        break;

                nskb->dev = ndev;

                if (__netif_rx(nskb) == NET_RX_SUCCESS) {
                        u64_stats_update_begin(&secy_stats->syncp);
                        secy_stats->stats.InPktsUntagged++;
                        u64_stats_update_end(&secy_stats->syncp);
                }
        }

out:
        rcu_read_unlock();
        return ret;
}

static rx_handler_result_t macsec_handle_frame(struct sk_buff **pskb)
{
        struct sk_buff *skb = *pskb;
        struct net_device *dev = skb->dev;
        struct macsec_eth_header *hdr;
        struct macsec_secy *secy = NULL;
        struct macsec_rx_sc *rx_sc;
        struct macsec_rx_sa *rx_sa;
        struct macsec_rxh_data *rxd;
        struct macsec_dev *macsec;
        unsigned int len;
        sci_t sci;
        u32 hdr_pn;
        bool cbit;
        struct pcpu_rx_sc_stats *rxsc_stats;
        struct pcpu_secy_stats *secy_stats;
        bool pulled_sci;
        int ret;

        if (skb_headroom(skb) < ETH_HLEN)
                goto drop_direct;

        hdr = macsec_ethhdr(skb);
        if (hdr->eth.h_proto != htons(ETH_P_MACSEC))
                return handle_not_macsec(skb);

        skb = skb_unshare(skb, GFP_ATOMIC);
        *pskb = skb;
        if (!skb)
                return RX_HANDLER_CONSUMED;

        pulled_sci = pskb_may_pull(skb, macsec_extra_len(true));
        if (!pulled_sci) {
                if (!pskb_may_pull(skb, macsec_extra_len(false)))
                        goto drop_direct;
        }

        hdr = macsec_ethhdr(skb);

        /* Frames with a SecTAG that has the TCI E bit set but the C
         * bit clear are discarded, as this reserved encoding is used
         * to identify frames with a SecTAG that are not to be
         * delivered to the Controlled Port.
         */
        if ((hdr->tci_an & (MACSEC_TCI_C | MACSEC_TCI_E)) == MACSEC_TCI_E)
                return RX_HANDLER_PASS;

        /* now, pull the extra length */
        if (hdr->tci_an & MACSEC_TCI_SC) {
                if (!pulled_sci)
                        goto drop_direct;
        }

        /* ethernet header is part of crypto processing */
        skb_push(skb, ETH_HLEN);

        macsec_skb_cb(skb)->has_sci = !!(hdr->tci_an & MACSEC_TCI_SC);
        macsec_skb_cb(skb)->assoc_num = hdr->tci_an & MACSEC_AN_MASK;
        sci = macsec_frame_sci(hdr, macsec_skb_cb(skb)->has_sci);

        rcu_read_lock();
        rxd = macsec_data_rcu(skb->dev);

        list_for_each_entry_rcu(macsec, &rxd->secys, secys) {
                struct macsec_rx_sc *sc = find_rx_sc(&macsec->secy, sci);

                sc = sc ? macsec_rxsc_get(sc) : NULL;

                if (sc) {
                        secy = &macsec->secy;
                        rx_sc = sc;
                        break;
                }
        }

        if (!secy)
                goto nosci;

        dev = secy->netdev;
        macsec = macsec_priv(dev);
        secy_stats = this_cpu_ptr(macsec->stats);
        rxsc_stats = this_cpu_ptr(rx_sc->stats);

        if (!macsec_validate_skb(skb, secy->icv_len, secy->xpn)) {
                u64_stats_update_begin(&secy_stats->syncp);
                secy_stats->stats.InPktsBadTag++;
                u64_stats_update_end(&secy_stats->syncp);
                secy->netdev->stats.rx_errors++;
                goto drop_nosa;
        }

        rx_sa = macsec_rxsa_get(rx_sc->sa[macsec_skb_cb(skb)->assoc_num]);
        if (!rx_sa) {
                /* 10.6.1 if the SA is not in use */

                /* If validateFrames is Strict or the C bit in the
                 * SecTAG is set, discard
                 */
                struct macsec_rx_sa *active_rx_sa = macsec_active_rxsa_get(rx_sc);
                if (hdr->tci_an & MACSEC_TCI_C ||
                    secy->validate_frames == MACSEC_VALIDATE_STRICT) {
                        u64_stats_update_begin(&rxsc_stats->syncp);
                        rxsc_stats->stats.InPktsNotUsingSA++;
                        u64_stats_update_end(&rxsc_stats->syncp);
                        secy->netdev->stats.rx_errors++;
                        if (active_rx_sa)
                                this_cpu_inc(active_rx_sa->stats->InPktsNotUsingSA);
                        goto drop_nosa;
                }

                /* not Strict, the frame (with the SecTAG and ICV
                 * removed) is delivered to the Controlled Port.
                 */
                u64_stats_update_begin(&rxsc_stats->syncp);
                rxsc_stats->stats.InPktsUnusedSA++;
                u64_stats_update_end(&rxsc_stats->syncp);
                if (active_rx_sa)
                        this_cpu_inc(active_rx_sa->stats->InPktsUnusedSA);
                goto deliver;
        }

        /* First, PN check to avoid decrypting obviously wrong packets */
        hdr_pn = ntohl(hdr->packet_number);
        if (secy->replay_protect) {
                bool late;

                spin_lock(&rx_sa->lock);
                late = rx_sa->next_pn_halves.lower >= secy->replay_window &&
                       hdr_pn < (rx_sa->next_pn_halves.lower - secy->replay_window);

                if (secy->xpn)
                        late = late && pn_same_half(rx_sa->next_pn_halves.lower, hdr_pn);
                spin_unlock(&rx_sa->lock);

                if (late) {
                        u64_stats_update_begin(&rxsc_stats->syncp);
                        rxsc_stats->stats.InPktsLate++;
                        u64_stats_update_end(&rxsc_stats->syncp);
                        macsec->secy.netdev->stats.rx_dropped++;
                        goto drop;
                }
        }

        macsec_skb_cb(skb)->rx_sa = rx_sa;

        /* Disabled && !changed text => skip validation */
        if (hdr->tci_an & MACSEC_TCI_C ||
            secy->validate_frames != MACSEC_VALIDATE_DISABLED)
                skb = macsec_decrypt(skb, dev, rx_sa, sci, secy);

        if (IS_ERR(skb)) {
                /* the decrypt callback needs the reference */
                if (PTR_ERR(skb) != -EINPROGRESS) {
                        macsec_rxsa_put(rx_sa);
                        macsec_rxsc_put(rx_sc);
                }
                rcu_read_unlock();
                *pskb = NULL;
                return RX_HANDLER_CONSUMED;
        }

        if (!macsec_post_decrypt(skb, secy, hdr_pn))
                goto drop;

deliver:
        macsec_finalize_skb(skb, secy->icv_len,
                            macsec_extra_len(macsec_skb_cb(skb)->has_sci));
        len = skb->len;
        macsec_reset_skb(skb, secy->netdev);

        if (rx_sa)
                macsec_rxsa_put(rx_sa);
        macsec_rxsc_put(rx_sc);

        skb_orphan(skb);
        ret = gro_cells_receive(&macsec->gro_cells, skb);
        if (ret == NET_RX_SUCCESS)
                count_rx(dev, len);
        else
                macsec->secy.netdev->stats.rx_dropped++;

        rcu_read_unlock();

        *pskb = NULL;
        return RX_HANDLER_CONSUMED;

drop:
        macsec_rxsa_put(rx_sa);
drop_nosa:
        macsec_rxsc_put(rx_sc);
        rcu_read_unlock();
drop_direct:
        kfree_skb(skb);
        *pskb = NULL;
        return RX_HANDLER_CONSUMED;

nosci:
        /* 10.6.1 if the SC is not found */
        cbit = !!(hdr->tci_an & MACSEC_TCI_C);
        if (!cbit)
                macsec_finalize_skb(skb, DEFAULT_ICV_LEN,
                                    macsec_extra_len(macsec_skb_cb(skb)->has_sci));

        list_for_each_entry_rcu(macsec, &rxd->secys, secys) {
                struct sk_buff *nskb;

                secy_stats = this_cpu_ptr(macsec->stats);

                /* If validateFrames is Strict or the C bit in the
                 * SecTAG is set, discard
                 */
                if (cbit ||
                    macsec->secy.validate_frames == MACSEC_VALIDATE_STRICT) {
                        u64_stats_update_begin(&secy_stats->syncp);
                        secy_stats->stats.InPktsNoSCI++;
                        u64_stats_update_end(&secy_stats->syncp);
                        macsec->secy.netdev->stats.rx_errors++;
                        continue;
                }

                /* not strict, the frame (with the SecTAG and ICV
                 * removed) is delivered to the Controlled Port.
                 */
                nskb = skb_clone(skb, GFP_ATOMIC);
                if (!nskb)
                        break;

                macsec_reset_skb(nskb, macsec->secy.netdev);

                ret = __netif_rx(nskb);
                if (ret == NET_RX_SUCCESS) {
                        u64_stats_update_begin(&secy_stats->syncp);
                        secy_stats->stats.InPktsUnknownSCI++;
                        u64_stats_update_end(&secy_stats->syncp);
                } else {
                        macsec->secy.netdev->stats.rx_dropped++;
                }
        }

        rcu_read_unlock();
        *pskb = skb;
        return RX_HANDLER_PASS;
}

static struct crypto_aead *macsec_alloc_tfm(char *key, int key_len, int icv_len)
{
        struct crypto_aead *tfm;
        int ret;

        /* Pick a sync gcm(aes) cipher to ensure order is preserved. */
        tfm = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);

        if (IS_ERR(tfm))
                return tfm;

        ret = crypto_aead_setkey(tfm, key, key_len);
        if (ret < 0)
                goto fail;

        ret = crypto_aead_setauthsize(tfm, icv_len);
        if (ret < 0)
                goto fail;

        return tfm;
fail:
        crypto_free_aead(tfm);
        return ERR_PTR(ret);
}

static int init_rx_sa(struct macsec_rx_sa *rx_sa, char *sak, int key_len,
                      int icv_len)
{
        rx_sa->stats = alloc_percpu(struct macsec_rx_sa_stats);
        if (!rx_sa->stats)
                return -ENOMEM;

        rx_sa->key.tfm = macsec_alloc_tfm(sak, key_len, icv_len);
        if (IS_ERR(rx_sa->key.tfm)) {
                free_percpu(rx_sa->stats);
                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);
        spin_lock_init(&rx_sa->lock);

        return 0;
}

static void clear_rx_sa(struct macsec_rx_sa *rx_sa)
{
        rx_sa->active = false;

        macsec_rxsa_put(rx_sa);
}

static void free_rx_sc(struct macsec_rx_sc *rx_sc)
{
        int i;

        for (i = 0; i < MACSEC_NUM_AN; i++) {
                struct macsec_rx_sa *sa = rtnl_dereference(rx_sc->sa[i]);

                RCU_INIT_POINTER(rx_sc->sa[i], NULL);
                if (sa)
                        clear_rx_sa(sa);
        }

        macsec_rxsc_put(rx_sc);
}

static struct macsec_rx_sc *del_rx_sc(struct macsec_secy *secy, sci_t sci)
{
        struct macsec_rx_sc *rx_sc, __rcu **rx_scp;

        for (rx_scp = &secy->rx_sc, rx_sc = rtnl_dereference(*rx_scp);
             rx_sc;
             rx_scp = &rx_sc->next, rx_sc = rtnl_dereference(*rx_scp)) {
                if (rx_sc->sci == sci) {
                        if (rx_sc->active)
                                secy->n_rx_sc--;
                        rcu_assign_pointer(*rx_scp, rx_sc->next);
                        return rx_sc;
                }
        }

        return NULL;
}

static struct macsec_rx_sc *create_rx_sc(struct net_device *dev, sci_t sci,
                                         bool active)
{
        struct macsec_rx_sc *rx_sc;
        struct macsec_dev *macsec;
        struct net_device *real_dev = macsec_priv(dev)->real_dev;
        struct macsec_rxh_data *rxd = macsec_data_rtnl(real_dev);
        struct macsec_secy *secy;

        list_for_each_entry(macsec, &rxd->secys, secys) {
                if (find_rx_sc_rtnl(&macsec->secy, sci))
                        return ERR_PTR(-EEXIST);
        }

        rx_sc = kzalloc(sizeof(*rx_sc), GFP_KERNEL);
        if (!rx_sc)
                return ERR_PTR(-ENOMEM);

        rx_sc->stats = netdev_alloc_pcpu_stats(struct pcpu_rx_sc_stats);
        if (!rx_sc->stats) {
                kfree(rx_sc);
                return ERR_PTR(-ENOMEM);
        }

        rx_sc->sci = sci;
        rx_sc->active = active;
        refcount_set(&rx_sc->refcnt, 1);

        secy = &macsec_priv(dev)->secy;
        rcu_assign_pointer(rx_sc->next, secy->rx_sc);
        rcu_assign_pointer(secy->rx_sc, rx_sc);

        if (rx_sc->active)
                secy->n_rx_sc++;

        return rx_sc;
}

static int init_tx_sa(struct macsec_tx_sa *tx_sa, char *sak, int key_len,
                      int icv_len)
{
        tx_sa->stats = alloc_percpu(struct macsec_tx_sa_stats);
        if (!tx_sa->stats)
                return -ENOMEM;

        tx_sa->key.tfm = macsec_alloc_tfm(sak, key_len, icv_len);
        if (IS_ERR(tx_sa->key.tfm)) {
                free_percpu(tx_sa->stats);
                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);

        return 0;
}

static void clear_tx_sa(struct macsec_tx_sa *tx_sa)
{
        tx_sa->active = false;

        macsec_txsa_put(tx_sa);
}

static struct genl_family macsec_fam;

static struct net_device *get_dev_from_nl(struct net *net,
                                          struct nlattr **attrs)
{
        int ifindex = nla_get_u32(attrs[MACSEC_ATTR_IFINDEX]);
        struct net_device *dev;

        dev = __dev_get_by_index(net, ifindex);
        if (!dev)
                return ERR_PTR(-ENODEV);

        if (!netif_is_macsec(dev))
                return ERR_PTR(-ENODEV);

        return dev;
}

static enum macsec_offload nla_get_offload(const struct nlattr *nla)
{
        return (__force enum macsec_offload)nla_get_u8(nla);
}

static sci_t nla_get_sci(const struct nlattr *nla)
{
        return (__force sci_t)nla_get_u64(nla);
}

static int nla_put_sci(struct sk_buff *skb, int attrtype, sci_t value,
                       int padattr)
{
        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,
                                             struct net_device **devp,
                                             struct macsec_secy **secyp,
                                             struct macsec_tx_sc **scp,
                                             u8 *assoc_num)
{
        struct net_device *dev;
        struct macsec_secy *secy;
        struct macsec_tx_sc *tx_sc;
        struct macsec_tx_sa *tx_sa;

        if (!tb_sa[MACSEC_SA_ATTR_AN])
                return ERR_PTR(-EINVAL);

        *assoc_num = nla_get_u8(tb_sa[MACSEC_SA_ATTR_AN]);

        dev = get_dev_from_nl(net, attrs);
        if (IS_ERR(dev))
                return ERR_CAST(dev);

        if (*assoc_num >= MACSEC_NUM_AN)
                return ERR_PTR(-EINVAL);

        secy = &macsec_priv(dev)->secy;
        tx_sc = &secy->tx_sc;

        tx_sa = rtnl_dereference(tx_sc->sa[*assoc_num]);
        if (!tx_sa)
                return ERR_PTR(-ENODEV);

        *devp = dev;
        *scp = tx_sc;
        *secyp = secy;
        return tx_sa;
}

static struct macsec_rx_sc *get_rxsc_from_nl(struct net *net,
                                             struct nlattr **attrs,
                                             struct nlattr **tb_rxsc,
                                             struct net_device **devp,
                                             struct macsec_secy **secyp)
{
        struct net_device *dev;
        struct macsec_secy *secy;
        struct macsec_rx_sc *rx_sc;
        sci_t sci;

        dev = get_dev_from_nl(net, attrs);
        if (IS_ERR(dev))
                return ERR_CAST(dev);

        secy = &macsec_priv(dev)->secy;

        if (!tb_rxsc[MACSEC_RXSC_ATTR_SCI])
                return ERR_PTR(-EINVAL);

        sci = nla_get_sci(tb_rxsc[MACSEC_RXSC_ATTR_SCI]);
        rx_sc = find_rx_sc_rtnl(secy, sci);
        if (!rx_sc)
                return ERR_PTR(-ENODEV);

        *secyp = secy;
        *devp = dev;

        return rx_sc;
}

static struct macsec_rx_sa *get_rxsa_from_nl(struct net *net,
                                             struct nlattr **attrs,
                                             struct nlattr **tb_rxsc,
                                             struct nlattr **tb_sa,
                                             struct net_device **devp,
                                             struct macsec_secy **secyp,
                                             struct macsec_rx_sc **scp,
                                             u8 *assoc_num)
{
        struct macsec_rx_sc *rx_sc;
        struct macsec_rx_sa *rx_sa;

        if (!tb_sa[MACSEC_SA_ATTR_AN])
                return ERR_PTR(-EINVAL);

        *assoc_num = nla_get_u8(tb_sa[MACSEC_SA_ATTR_AN]);
        if (*assoc_num >= MACSEC_NUM_AN)
                return ERR_PTR(-EINVAL);

        rx_sc = get_rxsc_from_nl(net, attrs, tb_rxsc, devp, secyp);
        if (IS_ERR(rx_sc))
                return ERR_CAST(rx_sc);

        rx_sa = rtnl_dereference(rx_sc->sa[*assoc_num]);
        if (!rx_sa)
                return ERR_PTR(-ENODEV);

        *scp = rx_sc;
        return rx_sa;
}

static const struct nla_policy macsec_genl_policy[NUM_MACSEC_ATTR] = {
        [MACSEC_ATTR_IFINDEX] = { .type = NLA_U32 },
        [MACSEC_ATTR_RXSC_CONFIG] = { .type = NLA_NESTED },
        [MACSEC_ATTR_SA_CONFIG] = { .type = NLA_NESTED },
        [MACSEC_ATTR_OFFLOAD] = { .type = NLA_NESTED },
};

static const struct nla_policy macsec_genl_rxsc_policy[NUM_MACSEC_RXSC_ATTR] = {
        [MACSEC_RXSC_ATTR_SCI] = { .type = NLA_U64 },
        [MACSEC_RXSC_ATTR_ACTIVE] = { .type = NLA_U8 },
};

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] = NLA_POLICY_MIN_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] = {
        [MACSEC_OFFLOAD_ATTR_TYPE] = { .type = NLA_U8 },
};

/* Offloads an operation to a device driver */
static int macsec_offload(int (* const func)(struct macsec_context *),
                          struct macsec_context *ctx)
{
        int ret;

        if (unlikely(!func))
                return 0;

        if (ctx->offload == MACSEC_OFFLOAD_PHY)
                mutex_lock(&ctx->phydev->lock);

        /* Phase I: prepare. The drive should fail here if there are going to be
         * issues in the commit phase.
         */
        ctx->prepare = true;
        ret = (*func)(ctx);
        if (ret)
                goto phy_unlock;

        /* Phase II: commit. This step cannot fail. */
        ctx->prepare = false;
        ret = (*func)(ctx);
        /* This should never happen: commit is not allowed to fail */
        if (unlikely(ret))
                WARN(1, "MACsec offloading commit failed (%d)\n", ret);

phy_unlock:
        if (ctx->offload == MACSEC_OFFLOAD_PHY)
                mutex_unlock(&ctx->phydev->lock);

        return ret;
}

static int parse_sa_config(struct nlattr **attrs, struct nlattr **tb_sa)
{
        if (!attrs[MACSEC_ATTR_SA_CONFIG])
                return -EINVAL;

        if (nla_parse_nested_deprecated(tb_sa, MACSEC_SA_ATTR_MAX, attrs[MACSEC_ATTR_SA_CONFIG], macsec_genl_sa_policy, NULL))
                return -EINVAL;

        return 0;
}

static int parse_rxsc_config(struct nlattr **attrs, struct nlattr **tb_rxsc)
{
        if (!attrs[MACSEC_ATTR_RXSC_CONFIG])
                return -EINVAL;

        if (nla_parse_nested_deprecated(tb_rxsc, MACSEC_RXSC_ATTR_MAX, attrs[MACSEC_ATTR_RXSC_CONFIG], macsec_genl_rxsc_policy, NULL))
                return -EINVAL;

        return 0;
}

static bool validate_add_rxsa(struct nlattr **attrs)
{
        if (!attrs[MACSEC_SA_ATTR_AN] ||
            !attrs[MACSEC_SA_ATTR_KEY] ||
            !attrs[MACSEC_SA_ATTR_KEYID])
                return false;

        if (nla_get_u8(attrs[MACSEC_SA_ATTR_AN]) >= MACSEC_NUM_AN)
                return false;

        if (attrs[MACSEC_SA_ATTR_PN] &&
            nla_get_u64(attrs[MACSEC_SA_ATTR_PN]) == 0)
                return false;

        if (attrs[MACSEC_SA_ATTR_ACTIVE]) {
                if (nla_get_u8(attrs[MACSEC_SA_ATTR_ACTIVE]) > 1)
                        return false;
        }

        if (nla_len(attrs[MACSEC_SA_ATTR_KEYID]) != MACSEC_KEYID_LEN)
                return false;

        return true;
}

static int macsec_add_rxsa(struct sk_buff *skb, struct genl_info *info)
{
        struct net_device *dev;
        struct nlattr **attrs = info->attrs;
        struct macsec_secy *secy;
        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;

        if (!attrs[MACSEC_ATTR_IFINDEX])
                return -EINVAL;

        if (parse_sa_config(attrs, tb_sa))
                return -EINVAL;

        if (parse_rxsc_config(attrs, tb_rxsc))
                return -EINVAL;

        if (!validate_add_rxsa(tb_sa))
                return -EINVAL;

        rtnl_lock();
        rx_sc = get_rxsc_from_nl(genl_info_net(info), attrs, tb_rxsc, &dev, &secy);
        if (IS_ERR(rx_sc)) {
                rtnl_unlock();
                return PTR_ERR(rx_sc);
        }

        assoc_num = nla_get_u8(tb_sa[MACSEC_SA_ATTR_AN]);

        if (nla_len(tb_sa[MACSEC_SA_ATTR_KEY]) != secy->key_len) {
                pr_notice("macsec: nl: add_rxsa: bad key length: %d != %d\n",
                          nla_len(tb_sa[MACSEC_SA_ATTR_KEY]), secy->key_len);
                rtnl_unlock();
                return -EINVAL;
        }

        pn_len = secy->xpn ? MACSEC_XPN_PN_LEN : MACSEC_DEFAULT_PN_LEN;
        if (tb_sa[MACSEC_SA_ATTR_PN] &&
            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_SALT_LEN);
                        rtnl_unlock();
                        return -EINVAL;
                }
        }

        rx_sa = rtnl_dereference(rx_sc->sa[assoc_num]);
        if (rx_sa) {
                rtnl_unlock();
                return -EBUSY;
        }

        rx_sa = kmalloc(sizeof(*rx_sa), GFP_KERNEL);
        if (!rx_sa) {
                rtnl_unlock();
                return -ENOMEM;
        }

        err = init_rx_sa(rx_sa, nla_data(tb_sa[MACSEC_SA_ATTR_KEY]),
                         secy->key_len, secy->icv_len);
        if (err < 0) {
                kfree(rx_sa);
                rtnl_unlock();
                return err;
        }

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

        if (tb_sa[MACSEC_SA_ATTR_ACTIVE])
                rx_sa->active = !!nla_get_u8(tb_sa[MACSEC_SA_ATTR_ACTIVE]);

        rx_sa->sc = rx_sc;

        /* If h/w offloading is available, propagate to the device */
        if (macsec_is_offloaded(netdev_priv(dev))) {
                const struct macsec_ops *ops;
                struct macsec_context ctx;

                ops = macsec_get_ops(netdev_priv(dev), &ctx);
                if (!ops) {
                        err = -EOPNOTSUPP;
                        goto cleanup;
                }

                ctx.sa.assoc_num = assoc_num;
                ctx.sa.rx_sa = rx_sa;
                ctx.secy = secy;
                memcpy(ctx.sa.key, nla_data(tb_sa[MACSEC_SA_ATTR_KEY]),
                       secy->key_len);

                err = macsec_offload(ops->mdo_add_rxsa, &ctx);
                memzero_explicit(ctx.sa.key, secy->key_len);
                if (err)
                        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);

        rtnl_unlock();

        return 0;

cleanup:
        macsec_rxsa_put(rx_sa);
        rtnl_unlock();
        return err;
}

static bool validate_add_rxsc(struct nlattr **attrs)
{
        if (!attrs[MACSEC_RXSC_ATTR_SCI])
                return false;

        if (attrs[MACSEC_RXSC_ATTR_ACTIVE]) {
                if (nla_get_u8(attrs[MACSEC_RXSC_ATTR_ACTIVE]) > 1)
                        return false;
        }

        return true;
}

static int macsec_add_rxsc(struct sk_buff *skb, struct genl_info *info)
{
        struct net_device *dev;
        sci_t sci = MACSEC_UNDEF_SCI;
        struct nlattr **attrs = info->attrs;
        struct macsec_rx_sc *rx_sc;
        struct nlattr *tb_rxsc[MACSEC_RXSC_ATTR_MAX + 1];
        struct macsec_secy *secy;
        bool active = true;
        int ret;

        if (!attrs[MACSEC_ATTR_IFINDEX])
                return -EINVAL;

        if (parse_rxsc_config(attrs, tb_rxsc))
                return -EINVAL;

        if (!validate_add_rxsc(tb_rxsc))
                return -EINVAL;

        rtnl_lock();
        dev = get_dev_from_nl(genl_info_net(info), attrs);
        if (IS_ERR(dev)) {
                rtnl_unlock();
                return PTR_ERR(dev);
        }

        secy = &macsec_priv(dev)->secy;
        sci = nla_get_sci(tb_rxsc[MACSEC_RXSC_ATTR_SCI]);

        if (tb_rxsc[MACSEC_RXSC_ATTR_ACTIVE])
                active = nla_get_u8(tb_rxsc[MACSEC_RXSC_ATTR_ACTIVE]);

        rx_sc = create_rx_sc(dev, sci, active);
        if (IS_ERR(rx_sc)) {
                rtnl_unlock();
                return PTR_ERR(rx_sc);
        }

        if (macsec_is_offloaded(netdev_priv(dev))) {
                const struct macsec_ops *ops;
                struct macsec_context ctx;

                ops = macsec_get_ops(netdev_priv(dev), &ctx);
                if (!ops) {
                        ret = -EOPNOTSUPP;
                        goto cleanup;
                }

                ctx.rx_sc = rx_sc;
                ctx.secy = secy;

                ret = macsec_offload(ops->mdo_add_rxsc, &ctx);
                if (ret)
                        goto cleanup;
        }

        rtnl_unlock();

        return 0;

cleanup:
        del_rx_sc(secy, sci);
        free_rx_sc(rx_sc);
        rtnl_unlock();
        return ret;
}

static bool validate_add_txsa(struct nlattr **attrs)
{
        if (!attrs[MACSEC_SA_ATTR_AN] ||
            !attrs[MACSEC_SA_ATTR_PN] ||
            !attrs[MACSEC_SA_ATTR_KEY] ||
            !attrs[MACSEC_SA_ATTR_KEYID])
                return false;

        if (nla_get_u8(attrs[MACSEC_SA_ATTR_AN]) >= MACSEC_NUM_AN)
                return false;

        if (nla_get_u64(attrs[MACSEC_SA_ATTR_PN]) == 0)
                return false;

        if (attrs[MACSEC_SA_ATTR_ACTIVE]) {
                if (nla_get_u8(attrs[MACSEC_SA_ATTR_ACTIVE]) > 1)
                        return false;
        }

        if (nla_len(attrs[MACSEC_SA_ATTR_KEYID]) != MACSEC_KEYID_LEN)
                return false;

        return true;
}

static int macsec_add_txsa(struct sk_buff *skb, struct genl_info *info)
{
        struct net_device *dev;
        struct nlattr **attrs = info->attrs;
        struct macsec_secy *secy;
        struct macsec_tx_sc *tx_sc;
        struct macsec_tx_sa *tx_sa;