root/drivers/net/geneve.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * GENEVE: Generic Network Virtualization Encapsulation
 *
 * Copyright (c) 2015 Red Hat, Inc.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/ethtool.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/etherdevice.h>
#include <linux/hash.h>
#include <net/ipv6_stubs.h>
#include <net/dst_metadata.h>
#include <net/gro_cells.h>
#include <net/rtnetlink.h>
#include <net/geneve.h>
#include <net/gro.h>
#include <net/netdev_lock.h>
#include <net/protocol.h>

#define GENEVE_NETDEV_VER       "0.6"

#define GENEVE_N_VID            (1u << 24)
#define GENEVE_VID_MASK         (GENEVE_N_VID - 1)

#define VNI_HASH_BITS           10
#define VNI_HASH_SIZE           (1<<VNI_HASH_BITS)

static bool log_ecn_error = true;
module_param(log_ecn_error, bool, 0644);
MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");

#define GENEVE_VER 0
#define GENEVE_BASE_HLEN (sizeof(struct udphdr) + sizeof(struct genevehdr))
#define GENEVE_IPV4_HLEN (ETH_HLEN + sizeof(struct iphdr) + GENEVE_BASE_HLEN)
#define GENEVE_IPV6_HLEN (ETH_HLEN + sizeof(struct ipv6hdr) + GENEVE_BASE_HLEN)

#define GENEVE_OPT_NETDEV_CLASS         0x100
#define GENEVE_OPT_GRO_HINT_SIZE        8
#define GENEVE_OPT_GRO_HINT_TYPE        1
#define GENEVE_OPT_GRO_HINT_LEN         1

struct geneve_opt_gro_hint {
        u8      inner_proto_id:2,
                nested_is_v6:1;
        u8      nested_nh_offset;
        u8      nested_tp_offset;
        u8      nested_hdr_len;
};

struct geneve_skb_cb {
        unsigned int    gro_hint_len;
        struct geneve_opt_gro_hint gro_hint;
};

#define GENEVE_SKB_CB(__skb)    ((struct geneve_skb_cb *)&((__skb)->cb[0]))

/* per-network namespace private data for this module */
struct geneve_net {
        struct list_head        geneve_list;
        /* sock_list is protected by rtnl lock */
        struct list_head        sock_list;
};

static unsigned int geneve_net_id;

struct geneve_dev_node {
        struct hlist_node hlist;
        struct geneve_dev *geneve;
};

struct geneve_config {
        bool                    collect_md;
        bool                    use_udp6_rx_checksums;
        bool                    ttl_inherit;
        bool                    gro_hint;
        enum ifla_geneve_df     df;
        bool                    inner_proto_inherit;
        u16                     port_min;
        u16                     port_max;

        /* Must be last --ends in a flexible-array member. */
        struct ip_tunnel_info   info;
};

/* Pseudo network device */
struct geneve_dev {
        struct geneve_dev_node hlist4;  /* vni hash table for IPv4 socket */
#if IS_ENABLED(CONFIG_IPV6)
        struct geneve_dev_node hlist6;  /* vni hash table for IPv6 socket */
#endif
        struct net         *net;        /* netns for packet i/o */
        struct net_device  *dev;        /* netdev for geneve tunnel */
        struct geneve_sock __rcu *sock4;        /* IPv4 socket used for geneve tunnel */
#if IS_ENABLED(CONFIG_IPV6)
        struct geneve_sock __rcu *sock6;        /* IPv6 socket used for geneve tunnel */
#endif
        struct list_head   next;        /* geneve's per namespace list */
        struct gro_cells   gro_cells;
        struct geneve_config cfg;
};

struct geneve_sock {
        bool                    collect_md;
        bool                    gro_hint;
        struct list_head        list;
        struct socket           *sock;
        struct rcu_head         rcu;
        int                     refcnt;
        struct hlist_head       vni_list[VNI_HASH_SIZE];
};

static const __be16 proto_id_map[] = { htons(ETH_P_TEB),
                                       htons(ETH_P_IPV6),
                                       htons(ETH_P_IP) };

static int proto_to_id(__be16 proto)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(proto_id_map); i++)
                if (proto_id_map[i] == proto)
                        return i;

        return -1;
}

static inline __u32 geneve_net_vni_hash(u8 vni[3])
{
        __u32 vnid;

        vnid = (vni[0] << 16) | (vni[1] << 8) | vni[2];
        return hash_32(vnid, VNI_HASH_BITS);
}

static __be64 vni_to_tunnel_id(const __u8 *vni)
{
#ifdef __BIG_ENDIAN
        return (vni[0] << 16) | (vni[1] << 8) | vni[2];
#else
        return (__force __be64)(((__force u64)vni[0] << 40) |
                                ((__force u64)vni[1] << 48) |
                                ((__force u64)vni[2] << 56));
#endif
}

/* Convert 64 bit tunnel ID to 24 bit VNI. */
static void tunnel_id_to_vni(__be64 tun_id, __u8 *vni)
{
#ifdef __BIG_ENDIAN
        vni[0] = (__force __u8)(tun_id >> 16);
        vni[1] = (__force __u8)(tun_id >> 8);
        vni[2] = (__force __u8)tun_id;
#else
        vni[0] = (__force __u8)((__force u64)tun_id >> 40);
        vni[1] = (__force __u8)((__force u64)tun_id >> 48);
        vni[2] = (__force __u8)((__force u64)tun_id >> 56);
#endif
}

static bool eq_tun_id_and_vni(u8 *tun_id, u8 *vni)
{
        return !memcmp(vni, &tun_id[5], 3);
}

static sa_family_t geneve_get_sk_family(struct geneve_sock *gs)
{
        return gs->sock->sk->sk_family;
}

static struct geneve_dev *geneve_lookup(struct geneve_sock *gs,
                                        __be32 addr, u8 vni[])
{
        struct hlist_head *vni_list_head;
        struct geneve_dev_node *node;
        __u32 hash;

        /* Find the device for this VNI */
        hash = geneve_net_vni_hash(vni);
        vni_list_head = &gs->vni_list[hash];
        hlist_for_each_entry_rcu(node, vni_list_head, hlist) {
                if (eq_tun_id_and_vni((u8 *)&node->geneve->cfg.info.key.tun_id, vni) &&
                    addr == node->geneve->cfg.info.key.u.ipv4.dst)
                        return node->geneve;
        }
        return NULL;
}

#if IS_ENABLED(CONFIG_IPV6)
static struct geneve_dev *geneve6_lookup(struct geneve_sock *gs,
                                         struct in6_addr addr6, u8 vni[])
{
        struct hlist_head *vni_list_head;
        struct geneve_dev_node *node;
        __u32 hash;

        /* Find the device for this VNI */
        hash = geneve_net_vni_hash(vni);
        vni_list_head = &gs->vni_list[hash];
        hlist_for_each_entry_rcu(node, vni_list_head, hlist) {
                if (eq_tun_id_and_vni((u8 *)&node->geneve->cfg.info.key.tun_id, vni) &&
                    ipv6_addr_equal(&addr6, &node->geneve->cfg.info.key.u.ipv6.dst))
                        return node->geneve;
        }
        return NULL;
}
#endif

static inline struct genevehdr *geneve_hdr(const struct sk_buff *skb)
{
        return (struct genevehdr *)(udp_hdr(skb) + 1);
}

static struct geneve_dev *geneve_lookup_skb(struct geneve_sock *gs,
                                            struct sk_buff *skb)
{
        static u8 zero_vni[3];
        u8 *vni;

        if (geneve_get_sk_family(gs) == AF_INET) {
                struct iphdr *iph;
                __be32 addr;

                iph = ip_hdr(skb); /* outer IP header... */

                if (gs->collect_md) {
                        vni = zero_vni;
                        addr = 0;
                } else {
                        vni = geneve_hdr(skb)->vni;
                        addr = iph->saddr;
                }

                return geneve_lookup(gs, addr, vni);
#if IS_ENABLED(CONFIG_IPV6)
        } else if (geneve_get_sk_family(gs) == AF_INET6) {
                static struct in6_addr zero_addr6;
                struct ipv6hdr *ip6h;
                struct in6_addr addr6;

                ip6h = ipv6_hdr(skb); /* outer IPv6 header... */

                if (gs->collect_md) {
                        vni = zero_vni;
                        addr6 = zero_addr6;
                } else {
                        vni = geneve_hdr(skb)->vni;
                        addr6 = ip6h->saddr;
                }

                return geneve6_lookup(gs, addr6, vni);
#endif
        }
        return NULL;
}

/* geneve receive/decap routine */
static void geneve_rx(struct geneve_dev *geneve, struct geneve_sock *gs,
                      struct sk_buff *skb, const struct genevehdr *gnvh)
{
        struct metadata_dst *tun_dst = NULL;
        unsigned int len;
        int nh, err = 0;
        void *oiph;

        if (ip_tunnel_collect_metadata() || gs->collect_md) {
                IP_TUNNEL_DECLARE_FLAGS(flags) = { };

                __set_bit(IP_TUNNEL_KEY_BIT, flags);
                __assign_bit(IP_TUNNEL_OAM_BIT, flags, gnvh->oam);
                __assign_bit(IP_TUNNEL_CRIT_OPT_BIT, flags, gnvh->critical);

                tun_dst = udp_tun_rx_dst(skb, geneve_get_sk_family(gs), flags,
                                         vni_to_tunnel_id(gnvh->vni),
                                         gnvh->opt_len * 4);
                if (!tun_dst) {
                        dev_dstats_rx_dropped(geneve->dev);
                        goto drop;
                }
                /* Update tunnel dst according to Geneve options. */
                ip_tunnel_flags_zero(flags);
                __set_bit(IP_TUNNEL_GENEVE_OPT_BIT, flags);
                ip_tunnel_info_opts_set(&tun_dst->u.tun_info,
                                        gnvh->options, gnvh->opt_len * 4,
                                        flags);
        } else {
                /* Drop packets w/ critical options,
                 * since we don't support any...
                 */
                if (gnvh->critical) {
                        DEV_STATS_INC(geneve->dev, rx_frame_errors);
                        DEV_STATS_INC(geneve->dev, rx_errors);
                        goto drop;
                }
        }

        if (tun_dst)
                skb_dst_set(skb, &tun_dst->dst);

        if (gnvh->proto_type == htons(ETH_P_TEB)) {
                skb_reset_mac_header(skb);
                skb->protocol = eth_type_trans(skb, geneve->dev);
                skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);

                /* Ignore packet loops (and multicast echo) */
                if (ether_addr_equal(eth_hdr(skb)->h_source,
                                     geneve->dev->dev_addr)) {
                        DEV_STATS_INC(geneve->dev, rx_errors);
                        goto drop;
                }
        } else {
                skb_reset_mac_header(skb);
                skb->dev = geneve->dev;
                skb->pkt_type = PACKET_HOST;
        }

        /* Save offset of outer header relative to skb->head,
         * because we are going to reset the network header to the inner header
         * and might change skb->head.
         */
        nh = skb_network_header(skb) - skb->head;

        skb_reset_network_header(skb);

        if (!pskb_inet_may_pull(skb)) {
                DEV_STATS_INC(geneve->dev, rx_length_errors);
                DEV_STATS_INC(geneve->dev, rx_errors);
                goto drop;
        }

        /* Get the outer header. */
        oiph = skb->head + nh;

        if (geneve_get_sk_family(gs) == AF_INET)
                err = IP_ECN_decapsulate(oiph, skb);
#if IS_ENABLED(CONFIG_IPV6)
        else
                err = IP6_ECN_decapsulate(oiph, skb);
#endif

        if (unlikely(err)) {
                if (log_ecn_error) {
                        if (geneve_get_sk_family(gs) == AF_INET)
                                net_info_ratelimited("non-ECT from %pI4 "
                                                     "with TOS=%#x\n",
                                                     &((struct iphdr *)oiph)->saddr,
                                                     ((struct iphdr *)oiph)->tos);
#if IS_ENABLED(CONFIG_IPV6)
                        else
                                net_info_ratelimited("non-ECT from %pI6\n",
                                                     &((struct ipv6hdr *)oiph)->saddr);
#endif
                }
                if (err > 1) {
                        DEV_STATS_INC(geneve->dev, rx_frame_errors);
                        DEV_STATS_INC(geneve->dev, rx_errors);
                        goto drop;
                }
        }

        /* Skip the additional GRO stage when hints are in use. */
        len = skb->len;
        if (skb->encapsulation)
                err = netif_rx(skb);
        else
                err = gro_cells_receive(&geneve->gro_cells, skb);
        if (likely(err == NET_RX_SUCCESS))
                dev_dstats_rx_add(geneve->dev, len);

        return;
drop:
        /* Consume bad packet */
        kfree_skb(skb);
}

/* Setup stats when device is created */
static int geneve_init(struct net_device *dev)
{
        struct geneve_dev *geneve = netdev_priv(dev);
        int err;

        err = gro_cells_init(&geneve->gro_cells, dev);
        if (err)
                return err;

        err = dst_cache_init(&geneve->cfg.info.dst_cache, GFP_KERNEL);
        if (err) {
                gro_cells_destroy(&geneve->gro_cells);
                return err;
        }
        netdev_lockdep_set_classes(dev);
        return 0;
}

static void geneve_uninit(struct net_device *dev)
{
        struct geneve_dev *geneve = netdev_priv(dev);

        dst_cache_destroy(&geneve->cfg.info.dst_cache);
        gro_cells_destroy(&geneve->gro_cells);
}

static int geneve_hlen(const struct genevehdr *gh)
{
        return sizeof(*gh) + gh->opt_len * 4;
}

/*
 * Look for GRO hint in the genenve options; if not found or does not pass basic
 * sanitization return 0, otherwise the offset WRT the geneve hdr start.
 */
static unsigned int
geneve_opt_gro_hint_off(const struct genevehdr *gh, __be16 *type,
                        unsigned int *gh_len)
{
        struct geneve_opt *opt = (void *)(gh + 1);
        unsigned int id, opt_len = gh->opt_len;
        struct geneve_opt_gro_hint *gro_hint;

        while (opt_len >= (GENEVE_OPT_GRO_HINT_SIZE >> 2)) {
                if (opt->opt_class == htons(GENEVE_OPT_NETDEV_CLASS) &&
                    opt->type == GENEVE_OPT_GRO_HINT_TYPE &&
                    opt->length == GENEVE_OPT_GRO_HINT_LEN)
                        goto found;

                /* check for bad opt len */
                if (opt->length + 1 >= opt_len)
                        return 0;

                /* next opt */
                opt_len -= opt->length + 1;
                opt = ((void *)opt) + ((opt->length + 1) << 2);
        }
        return 0;

found:
        gro_hint = (struct geneve_opt_gro_hint *)opt->opt_data;

        /*
         * Sanitize the hinted hdrs: the nested transport is UDP and must fit
         * the overall hinted hdr size.
         */
        if (gro_hint->nested_tp_offset + sizeof(struct udphdr) >
            gro_hint->nested_hdr_len)
                return 0;

        if (gro_hint->nested_nh_offset +
            (gro_hint->nested_is_v6 ? sizeof(struct ipv6hdr) :
                                      sizeof(struct iphdr)) >
            gro_hint->nested_tp_offset)
                return 0;

        /* Allow only supported L2. */
        id = gro_hint->inner_proto_id;
        if (id >= ARRAY_SIZE(proto_id_map))
                return 0;

        *type = proto_id_map[id];
        *gh_len += gro_hint->nested_hdr_len;

        return (void *)gro_hint - (void *)gh;
}

static const struct geneve_opt_gro_hint *
geneve_opt_gro_hint(const struct genevehdr *gh, unsigned int hint_off)
{
        return (const struct geneve_opt_gro_hint *)((void *)gh + hint_off);
}

static unsigned int
geneve_sk_gro_hint_off(const struct sock *sk, const struct genevehdr *gh,
                       __be16 *type, unsigned int *gh_len)
{
        const struct geneve_sock *gs = rcu_dereference_sk_user_data(sk);

        if (!gs || !gs->gro_hint)
                return 0;
        return geneve_opt_gro_hint_off(gh, type, gh_len);
}

/* Validate the packet headers pointed by data WRT the provided hint */
static bool
geneve_opt_gro_hint_validate(void *data,
                             const struct geneve_opt_gro_hint *gro_hint)
{
        void *nested_nh = data + gro_hint->nested_nh_offset;
        struct iphdr *iph;

        if (gro_hint->nested_is_v6) {
                struct ipv6hdr *ipv6h = nested_nh;
                struct ipv6_opt_hdr *opth;
                int offset, len;

                if (ipv6h->nexthdr == IPPROTO_UDP)
                        return true;

                offset = sizeof(*ipv6h) + gro_hint->nested_nh_offset;
                while (offset + sizeof(*opth) <= gro_hint->nested_tp_offset) {
                        opth = data + offset;

                        len = ipv6_optlen(opth);
                        if (len + offset > gro_hint->nested_tp_offset)
                                return false;
                        if (opth->nexthdr == IPPROTO_UDP)
                                return true;

                        offset += len;
                }
                return false;
        }

        iph = nested_nh;
        if (*(u8 *)iph != 0x45 || ip_is_fragment(iph) ||
            iph->protocol != IPPROTO_UDP || ip_fast_csum((u8 *)iph, 5))
                return false;

        return true;
}

/*
 * Validate the skb headers following the specified geneve hdr vs the
 * provided hint, including nested L4 checksum.
 * The caller already ensured that the relevant amount of data is available
 * in the linear part.
 */
static bool
geneve_opt_gro_hint_validate_csum(const struct sk_buff *skb,
                                  const struct genevehdr *gh,
                                  const struct geneve_opt_gro_hint *gro_hint)
{
        unsigned int plen, gh_len = geneve_hlen(gh);
        void *nested = (void *)gh + gh_len;
        struct udphdr *nested_uh;
        unsigned int nested_len;
        struct ipv6hdr *ipv6h;
        struct iphdr *iph;
        __wsum csum, psum;

        if (!geneve_opt_gro_hint_validate(nested, gro_hint))
                return false;

        /* Use GRO hints with nested csum only if the outer header has csum. */
        nested_uh = nested + gro_hint->nested_tp_offset;
        if (!nested_uh->check || skb->ip_summed == CHECKSUM_PARTIAL)
                return true;

        if (!NAPI_GRO_CB(skb)->csum_valid)
                return false;

        /* Compute the complete checksum up to the nested transport. */
        plen = gh_len + gro_hint->nested_tp_offset;
        csum = csum_sub(NAPI_GRO_CB(skb)->csum, csum_partial(gh, plen, 0));
        nested_len = skb_gro_len(skb) - plen;

        /* Compute the nested pseudo header csum. */
        ipv6h = nested + gro_hint->nested_nh_offset;
        iph = (struct iphdr *)ipv6h;
        psum = gro_hint->nested_is_v6 ?
               ~csum_unfold(csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
                                            nested_len, IPPROTO_UDP, 0)) :
               csum_tcpudp_nofold(iph->saddr, iph->daddr,
                                  nested_len, IPPROTO_UDP, 0);

        return !csum_fold(csum_add(psum, csum));
}

static int geneve_post_decap_hint(const struct sock *sk, struct sk_buff *skb,
                                  unsigned int gh_len,
                                  struct genevehdr **geneveh)
{
        const struct geneve_opt_gro_hint *gro_hint;
        unsigned int len, total_len, hint_off;
        struct ipv6hdr *ipv6h;
        struct iphdr *iph;
        struct udphdr *uh;
        __be16 p;

        hint_off = geneve_sk_gro_hint_off(sk, *geneveh, &p, &len);
        if (!hint_off)
                return 0;

        if (!skb_is_gso(skb))
                return 0;

        gro_hint = geneve_opt_gro_hint(*geneveh, hint_off);
        if (unlikely(!pskb_may_pull(skb, gro_hint->nested_hdr_len)))
                return -ENOMEM;

        *geneveh = geneve_hdr(skb);
        gro_hint = geneve_opt_gro_hint(*geneveh, hint_off);

        /*
         * Validate hints from untrusted source before accessing
         * the headers; csum will be checked later by the nested
         * protocol rx path.
         */
        if (unlikely(skb_shinfo(skb)->gso_type & SKB_GSO_DODGY &&
                     !geneve_opt_gro_hint_validate(skb->data, gro_hint)))
                return -EINVAL;

        ipv6h = (void *)skb->data + gro_hint->nested_nh_offset;
        iph = (struct iphdr *)ipv6h;
        total_len = skb->len - gro_hint->nested_nh_offset;
        if (total_len > GRO_LEGACY_MAX_SIZE)
                return -E2BIG;

        /*
         * After stripping the outer encap, the packet still carries a
         * tunnel encapsulation: the nested one.
         */
        skb->encapsulation = 1;

        /* GSO expect a valid transpor header, move it to the current one. */
        skb_set_transport_header(skb, gro_hint->nested_tp_offset);

        /* Adjust the nested IP{6} hdr to actual GSO len. */
        if (gro_hint->nested_is_v6) {
                ipv6h->payload_len = htons(total_len - sizeof(*ipv6h));
        } else {
                __be16 old_len = iph->tot_len;

                iph->tot_len = htons(total_len);

                /* For IPv4 additionally adjust the nested csum. */
                csum_replace2(&iph->check, old_len, iph->tot_len);
                ip_send_check(iph);
        }

        /* Adjust the nested UDP header len and checksum. */
        uh = udp_hdr(skb);
        uh->len = htons(skb->len - gro_hint->nested_tp_offset);
        if (uh->check) {
                len = skb->len - gro_hint->nested_nh_offset;
                skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
                if (gro_hint->nested_is_v6)
                        uh->check = ~udp_v6_check(len, &ipv6h->saddr,
                                                  &ipv6h->daddr, 0);
                else
                        uh->check = ~udp_v4_check(len, iph->saddr,
                                                  iph->daddr, 0);
        } else {
                skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL;
        }
        return 0;
}

/* Callback from net/ipv4/udp.c to receive packets */
static int geneve_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
{
        struct genevehdr *geneveh;
        struct geneve_dev *geneve;
        struct geneve_sock *gs;
        __be16 inner_proto;
        int opts_len;

        /* Need UDP and Geneve header to be present */
        if (unlikely(!pskb_may_pull(skb, GENEVE_BASE_HLEN)))
                goto drop;

        /* Return packets with reserved bits set */
        geneveh = geneve_hdr(skb);
        if (unlikely(geneveh->ver != GENEVE_VER))
                goto drop;

        gs = rcu_dereference_sk_user_data(sk);
        if (!gs)
                goto drop;

        geneve = geneve_lookup_skb(gs, skb);
        if (!geneve)
                goto drop;

        inner_proto = geneveh->proto_type;

        if (unlikely((!geneve->cfg.inner_proto_inherit &&
                      inner_proto != htons(ETH_P_TEB)))) {
                dev_dstats_rx_dropped(geneve->dev);
                goto drop;
        }

        opts_len = geneveh->opt_len * 4;
        if (iptunnel_pull_header(skb, GENEVE_BASE_HLEN + opts_len, inner_proto,
                                 !net_eq(geneve->net, dev_net(geneve->dev)))) {
                dev_dstats_rx_dropped(geneve->dev);
                goto drop;
        }

        /*
         * After hint processing, the transport header points to the inner one
         * and we can't use anymore on geneve_hdr().
         */
        geneveh = geneve_hdr(skb);
        if (geneve_post_decap_hint(sk, skb, sizeof(struct genevehdr) +
                                   opts_len, &geneveh)) {
                DEV_STATS_INC(geneve->dev, rx_errors);
                goto drop;
        }

        geneve_rx(geneve, gs, skb, geneveh);
        return 0;

drop:
        /* Consume bad packet */
        kfree_skb(skb);
        return 0;
}

/* Callback from net/ipv{4,6}/udp.c to check that we have a tunnel for errors */
static int geneve_udp_encap_err_lookup(struct sock *sk, struct sk_buff *skb)
{
        struct genevehdr *geneveh;
        struct geneve_sock *gs;
        u8 zero_vni[3] = { 0 };
        u8 *vni = zero_vni;

        if (!pskb_may_pull(skb, skb_transport_offset(skb) + GENEVE_BASE_HLEN))
                return -EINVAL;

        geneveh = geneve_hdr(skb);
        if (geneveh->ver != GENEVE_VER)
                return -EINVAL;

        if (geneveh->proto_type != htons(ETH_P_TEB))
                return -EINVAL;

        gs = rcu_dereference_sk_user_data(sk);
        if (!gs)
                return -ENOENT;

        if (geneve_get_sk_family(gs) == AF_INET) {
                struct iphdr *iph = ip_hdr(skb);
                __be32 addr4 = 0;

                if (!gs->collect_md) {
                        vni = geneve_hdr(skb)->vni;
                        addr4 = iph->daddr;
                }

                return geneve_lookup(gs, addr4, vni) ? 0 : -ENOENT;
        }

#if IS_ENABLED(CONFIG_IPV6)
        if (geneve_get_sk_family(gs) == AF_INET6) {
                struct ipv6hdr *ip6h = ipv6_hdr(skb);
                struct in6_addr addr6;

                memset(&addr6, 0, sizeof(struct in6_addr));

                if (!gs->collect_md) {
                        vni = geneve_hdr(skb)->vni;
                        addr6 = ip6h->daddr;
                }

                return geneve6_lookup(gs, addr6, vni) ? 0 : -ENOENT;
        }
#endif

        return -EPFNOSUPPORT;
}

static struct socket *geneve_create_sock(struct net *net, bool ipv6,
                                         __be16 port, bool ipv6_rx_csum)
{
        struct socket *sock;
        struct udp_port_cfg udp_conf;
        int err;

        memset(&udp_conf, 0, sizeof(udp_conf));

        if (ipv6) {
                udp_conf.family = AF_INET6;
                udp_conf.ipv6_v6only = 1;
                udp_conf.use_udp6_rx_checksums = ipv6_rx_csum;
        } else {
                udp_conf.family = AF_INET;
                udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
        }

        udp_conf.local_udp_port = port;

        /* Open UDP socket */
        err = udp_sock_create(net, &udp_conf, &sock);
        if (err < 0)
                return ERR_PTR(err);

        udp_allow_gso(sock->sk);
        return sock;
}

static bool geneve_hdr_match(struct sk_buff *skb,
                             const struct genevehdr *gh,
                             const struct genevehdr *gh2,
                             unsigned int hint_off)
{
        const struct geneve_opt_gro_hint *gro_hint;
        void *nested, *nested2, *nh, *nh2;
        struct udphdr *udp, *udp2;
        unsigned int gh_len;

        /* Match the geneve hdr and options */
        if (gh->opt_len != gh2->opt_len)
                return false;

        gh_len = geneve_hlen(gh);
        if (memcmp(gh, gh2, gh_len))
                return false;

        if (!hint_off)
                return true;

        /*
         * When gro is present consider the nested headers as part
         * of the geneve options
         */
        nested = (void *)gh + gh_len;
        nested2 = (void *)gh2 + gh_len;
        gro_hint = geneve_opt_gro_hint(gh, hint_off);
        if (!memcmp(nested, nested2, gro_hint->nested_hdr_len))
                return true;

        /*
         * The nested headers differ; the packets can still belong to
         * the same flow when IPs/proto/ports match; if so flushing is
         * required.
         */
        nh = nested + gro_hint->nested_nh_offset;
        nh2 = nested2 + gro_hint->nested_nh_offset;
        if (gro_hint->nested_is_v6) {
                struct ipv6hdr *iph = nh, *iph2 = nh2;
                unsigned int nested_nlen;
                __be32 first_word;

                first_word = *(__be32 *)iph ^ *(__be32 *)iph2;
                if ((first_word & htonl(0xF00FFFFF)) ||
                    !ipv6_addr_equal(&iph->saddr, &iph2->saddr) ||
                    !ipv6_addr_equal(&iph->daddr, &iph2->daddr) ||
                    iph->nexthdr != iph2->nexthdr)
                        return false;

                nested_nlen = gro_hint->nested_tp_offset -
                              gro_hint->nested_nh_offset;
                if (nested_nlen > sizeof(struct ipv6hdr) &&
                    (memcmp(iph + 1, iph2 + 1,
                            nested_nlen - sizeof(struct ipv6hdr))))
                        return false;
        } else {
                struct iphdr *iph = nh, *iph2 = nh2;

                if ((iph->protocol ^ iph2->protocol) |
                    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
                    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr))
                        return false;
        }

        udp = nested + gro_hint->nested_tp_offset;
        udp2 = nested2 + gro_hint->nested_tp_offset;
        if (udp->source != udp2->source || udp->dest != udp2->dest ||
            udp->check != udp2->check)
                return false;

        NAPI_GRO_CB(skb)->flush = 1;
        return true;
}

static struct sk_buff *geneve_gro_receive(struct sock *sk,
                                          struct list_head *head,
                                          struct sk_buff *skb)
{
        unsigned int hlen, gh_len, off_gnv, hint_off;
        const struct geneve_opt_gro_hint *gro_hint;
        const struct packet_offload *ptype;
        struct genevehdr *gh, *gh2;
        struct sk_buff *pp = NULL;
        struct sk_buff *p;
        int flush = 1;
        __be16 type;

        off_gnv = skb_gro_offset(skb);
        hlen = off_gnv + sizeof(*gh);
        gh = skb_gro_header(skb, hlen, off_gnv);
        if (unlikely(!gh))
                goto out;

        if (gh->ver != GENEVE_VER || gh->oam)
                goto out;
        gh_len = geneve_hlen(gh);
        type = gh->proto_type;

        hlen = off_gnv + gh_len;
        if (!skb_gro_may_pull(skb, hlen)) {
                gh = skb_gro_header_slow(skb, hlen, off_gnv);
                if (unlikely(!gh))
                        goto out;
        }

        /* The GRO hint/nested hdr could use a different ethernet type. */
        hint_off = geneve_sk_gro_hint_off(sk, gh, &type, &gh_len);
        if (hint_off) {

                /*
                 * If the hint is present, and nested hdr validation fails, do
                 * not attempt plain GRO: it will ignore inner hdrs and cause
                 * OoO.
                 */
                gh = skb_gro_header(skb, off_gnv + gh_len, off_gnv);
                if (unlikely(!gh))
                        goto out;

                gro_hint = geneve_opt_gro_hint(gh, hint_off);
                if (!geneve_opt_gro_hint_validate_csum(skb, gh, gro_hint))
                        goto out;
        }

        list_for_each_entry(p, head, list) {
                if (!NAPI_GRO_CB(p)->same_flow)
                        continue;

                gh2 = (struct genevehdr *)(p->data + off_gnv);
                if (!geneve_hdr_match(skb, gh, gh2, hint_off)) {
                        NAPI_GRO_CB(p)->same_flow = 0;
                        continue;
                }
        }

        skb_gro_pull(skb, gh_len);
        skb_gro_postpull_rcsum(skb, gh, gh_len);
        if (likely(type == htons(ETH_P_TEB)))
                return call_gro_receive(eth_gro_receive, head, skb);

        ptype = gro_find_receive_by_type(type);
        if (!ptype)
                goto out;

        pp = call_gro_receive(ptype->callbacks.gro_receive, head, skb);
        flush = 0;

out:
        skb_gro_flush_final(skb, pp, flush);

        return pp;
}

static int geneve_gro_complete(struct sock *sk, struct sk_buff *skb,
                               int nhoff)
{
        struct genevehdr *gh;
        struct packet_offload *ptype;
        __be16 type;
        int gh_len;
        int err = -ENOSYS;

        gh = (struct genevehdr *)(skb->data + nhoff);
        gh_len = geneve_hlen(gh);
        type = gh->proto_type;
        geneve_opt_gro_hint_off(gh, &type, &gh_len);

        /* since skb->encapsulation is set, eth_gro_complete() sets the inner mac header */
        if (likely(type == htons(ETH_P_TEB)))
                return eth_gro_complete(skb, nhoff + gh_len);

        ptype = gro_find_complete_by_type(type);
        if (ptype)
                err = ptype->callbacks.gro_complete(skb, nhoff + gh_len);

        skb_set_inner_mac_header(skb, nhoff + gh_len);

        return err;
}

/* Create new listen socket if needed */
static struct geneve_sock *geneve_socket_create(struct net *net, __be16 port,
                                                bool ipv6, bool ipv6_rx_csum)
{
        struct geneve_net *gn = net_generic(net, geneve_net_id);
        struct geneve_sock *gs;
        struct socket *sock;
        struct udp_tunnel_sock_cfg tunnel_cfg;
        int h;

        gs = kzalloc_obj(*gs);
        if (!gs)
                return ERR_PTR(-ENOMEM);

        sock = geneve_create_sock(net, ipv6, port, ipv6_rx_csum);
        if (IS_ERR(sock)) {
                kfree(gs);
                return ERR_CAST(sock);
        }

        gs->sock = sock;
        gs->refcnt = 1;
        for (h = 0; h < VNI_HASH_SIZE; ++h)
                INIT_HLIST_HEAD(&gs->vni_list[h]);

        /* Initialize the geneve udp offloads structure */
        udp_tunnel_notify_add_rx_port(gs->sock, UDP_TUNNEL_TYPE_GENEVE);

        /* Mark socket as an encapsulation socket */
        memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
        tunnel_cfg.sk_user_data = gs;
        tunnel_cfg.encap_type = 1;
        tunnel_cfg.gro_receive = geneve_gro_receive;
        tunnel_cfg.gro_complete = geneve_gro_complete;
        tunnel_cfg.encap_rcv = geneve_udp_encap_recv;
        tunnel_cfg.encap_err_lookup = geneve_udp_encap_err_lookup;
        tunnel_cfg.encap_destroy = NULL;
        setup_udp_tunnel_sock(net, sock, &tunnel_cfg);
        list_add(&gs->list, &gn->sock_list);
        return gs;
}

static void __geneve_sock_release(struct geneve_sock *gs)
{
        if (!gs || --gs->refcnt)
                return;

        list_del(&gs->list);
        udp_tunnel_notify_del_rx_port(gs->sock, UDP_TUNNEL_TYPE_GENEVE);
        udp_tunnel_sock_release(gs->sock);
        kfree_rcu(gs, rcu);
}

static void geneve_sock_release(struct geneve_dev *geneve)
{
        struct geneve_sock *gs4 = rtnl_dereference(geneve->sock4);
#if IS_ENABLED(CONFIG_IPV6)
        struct geneve_sock *gs6 = rtnl_dereference(geneve->sock6);

        rcu_assign_pointer(geneve->sock6, NULL);
#endif

        rcu_assign_pointer(geneve->sock4, NULL);
        synchronize_net();

        __geneve_sock_release(gs4);
#if IS_ENABLED(CONFIG_IPV6)
        __geneve_sock_release(gs6);
#endif
}

static struct geneve_sock *geneve_find_sock(struct geneve_net *gn,
                                            sa_family_t family,
                                            __be16 dst_port,
                                            bool gro_hint)
{
        struct geneve_sock *gs;

        list_for_each_entry(gs, &gn->sock_list, list) {
                if (inet_sk(gs->sock->sk)->inet_sport == dst_port &&
                    geneve_get_sk_family(gs) == family &&
                    gs->gro_hint == gro_hint) {
                        return gs;
                }
        }
        return NULL;
}

static int geneve_sock_add(struct geneve_dev *geneve, bool ipv6)
{
        struct net *net = geneve->net;
        struct geneve_net *gn = net_generic(net, geneve_net_id);
        bool gro_hint = geneve->cfg.gro_hint;
        struct geneve_dev_node *node;
        struct geneve_sock *gs;
        __u8 vni[3];
        __u32 hash;

        gs = geneve_find_sock(gn, ipv6 ? AF_INET6 : AF_INET,
                              geneve->cfg.info.key.tp_dst, gro_hint);
        if (gs) {
                gs->refcnt++;
                goto out;
        }

        gs = geneve_socket_create(net, geneve->cfg.info.key.tp_dst, ipv6,
                                  geneve->cfg.use_udp6_rx_checksums);
        if (IS_ERR(gs))
                return PTR_ERR(gs);

out:
        gs->collect_md = geneve->cfg.collect_md;
        gs->gro_hint = gro_hint;
#if IS_ENABLED(CONFIG_IPV6)
        if (ipv6) {
                rcu_assign_pointer(geneve->sock6, gs);
                node = &geneve->hlist6;
        } else
#endif
        {
                rcu_assign_pointer(geneve->sock4, gs);
                node = &geneve->hlist4;
        }
        node->geneve = geneve;

        tunnel_id_to_vni(geneve->cfg.info.key.tun_id, vni);
        hash = geneve_net_vni_hash(vni);
        hlist_add_head_rcu(&node->hlist, &gs->vni_list[hash]);
        return 0;
}

static int geneve_open(struct net_device *dev)
{
        struct geneve_dev *geneve = netdev_priv(dev);
        bool metadata = geneve->cfg.collect_md;
        bool ipv4, ipv6;
        int ret = 0;

        ipv6 = geneve->cfg.info.mode & IP_TUNNEL_INFO_IPV6 || metadata;
        ipv4 = !ipv6 || metadata;
#if IS_ENABLED(CONFIG_IPV6)
        if (ipv6) {
                ret = geneve_sock_add(geneve, true);
                if (ret < 0 && ret != -EAFNOSUPPORT)
                        ipv4 = false;
        }
#endif
        if (ipv4)
                ret = geneve_sock_add(geneve, false);
        if (ret < 0)
                geneve_sock_release(geneve);

        return ret;
}

static int geneve_stop(struct net_device *dev)
{
        struct geneve_dev *geneve = netdev_priv(dev);

        hlist_del_init_rcu(&geneve->hlist4.hlist);
#if IS_ENABLED(CONFIG_IPV6)
        hlist_del_init_rcu(&geneve->hlist6.hlist);
#endif
        geneve_sock_release(geneve);
        return 0;
}

static void geneve_build_header(struct genevehdr *geneveh,
                                const struct ip_tunnel_info *info,
                                __be16 inner_proto)
{
        geneveh->ver = GENEVE_VER;
        geneveh->opt_len = info->options_len / 4;
        geneveh->oam = test_bit(IP_TUNNEL_OAM_BIT, info->key.tun_flags);
        geneveh->critical = test_bit(IP_TUNNEL_CRIT_OPT_BIT,
                                     info->key.tun_flags);
        geneveh->rsvd1 = 0;
        tunnel_id_to_vni(info->key.tun_id, geneveh->vni);
        geneveh->proto_type = inner_proto;
        geneveh->rsvd2 = 0;

        if (test_bit(IP_TUNNEL_GENEVE_OPT_BIT, info->key.tun_flags))
                ip_tunnel_info_opts_get(geneveh->options, info);
}

static int geneve_build_gro_hint_opt(const struct geneve_dev *geneve,
                                     struct sk_buff *skb)
{
        struct geneve_skb_cb *cb = GENEVE_SKB_CB(skb);
        struct geneve_opt_gro_hint *hint;
        unsigned int nhlen;
        bool nested_is_v6;
        int id;

        BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct geneve_skb_cb));
        cb->gro_hint_len = 0;

        /* Try to add the GRO hint only in case of double encap. */
        if (!geneve->cfg.gro_hint || !skb->encapsulation)
                return 0;

        /*
         * The nested headers must fit the geneve opt len fields and the
         * nested encap must carry a nested transport (UDP) header.
         */
        nhlen = skb_inner_mac_header(skb) - skb->data;
        if (nhlen > 255 || !skb_transport_header_was_set(skb) ||
            skb->inner_protocol_type != ENCAP_TYPE_ETHER ||
            (skb_transport_offset(skb) + sizeof(struct udphdr) > nhlen))
                return 0;

        id = proto_to_id(skb->inner_protocol);
        if (id < 0)
                return 0;

        nested_is_v6 = skb->protocol == htons(ETH_P_IPV6);
        if (nested_is_v6) {
                int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
                u8 proto = ipv6_hdr(skb)->nexthdr;
                __be16 foff;

                if (ipv6_skip_exthdr(skb, start, &proto, &foff) < 0 ||
                    proto != IPPROTO_UDP)
                        return 0;
        } else {
                if (ip_hdr(skb)->protocol != IPPROTO_UDP)
                        return 0;
        }

        hint = &cb->gro_hint;
        memset(hint, 0, sizeof(*hint));
        hint->inner_proto_id = id;
        hint->nested_is_v6 = skb->protocol == htons(ETH_P_IPV6);
        hint->nested_nh_offset = skb_network_offset(skb);
        hint->nested_tp_offset = skb_transport_offset(skb);
        hint->nested_hdr_len = nhlen;
        cb->gro_hint_len = GENEVE_OPT_GRO_HINT_SIZE;
        return GENEVE_OPT_GRO_HINT_SIZE;
}

static void geneve_put_gro_hint_opt(struct genevehdr *gnvh, int opt_size,
                                    const struct geneve_opt_gro_hint *hint)
{
        struct geneve_opt *gro_opt;

        /* geneve_build_header() did not took in account the GRO hint. */
        gnvh->opt_len = (opt_size + GENEVE_OPT_GRO_HINT_SIZE) >> 2;

        gro_opt = (void *)(gnvh + 1) + opt_size;
        memset(gro_opt, 0, sizeof(*gro_opt));

        gro_opt->opt_class = htons(GENEVE_OPT_NETDEV_CLASS);
        gro_opt->type = GENEVE_OPT_GRO_HINT_TYPE;
        gro_opt->length = GENEVE_OPT_GRO_HINT_LEN;
        memcpy(gro_opt + 1, hint, sizeof(*hint));
}

static int geneve_build_skb(struct dst_entry *dst, struct sk_buff *skb,
                            const struct ip_tunnel_info *info,
                            const struct geneve_dev *geneve, int ip_hdr_len)
{
        bool udp_sum = test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
        bool inner_proto_inherit = geneve->cfg.inner_proto_inherit;
        bool xnet = !net_eq(geneve->net, dev_net(geneve->dev));
        struct geneve_skb_cb *cb = GENEVE_SKB_CB(skb);
        struct genevehdr *gnvh;
        __be16 inner_proto;
        bool double_encap;
        int min_headroom;
        int opt_size;
        int err;

        skb_reset_mac_header(skb);
        skb_scrub_packet(skb, xnet);

        opt_size =  info->options_len + cb->gro_hint_len;
        min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len +
                       GENEVE_BASE_HLEN + opt_size + ip_hdr_len;
        err = skb_cow_head(skb, min_headroom);
        if (unlikely(err))
                goto free_dst;

        double_encap = udp_tunnel_handle_partial(skb);
        err = udp_tunnel_handle_offloads(skb, udp_sum);
        if (err)
                goto free_dst;

        gnvh = __skb_push(skb, sizeof(*gnvh) + opt_size);
        inner_proto = inner_proto_inherit ? skb->protocol : htons(ETH_P_TEB);
        geneve_build_header(gnvh, info, inner_proto);

        if (cb->gro_hint_len)
                geneve_put_gro_hint_opt(gnvh, info->options_len, &cb->gro_hint);

        udp_tunnel_set_inner_protocol(skb, double_encap, inner_proto);
        return 0;

free_dst:
        dst_release(dst);
        return err;
}

static u8 geneve_get_dsfield(struct sk_buff *skb, struct net_device *dev,
                             const struct ip_tunnel_info *info,
                             bool *use_cache)
{
        struct geneve_dev *geneve = netdev_priv(dev);
        u8 dsfield;

        dsfield = info->key.tos;
        if (dsfield == 1 && !geneve->cfg.collect_md) {
                dsfield = ip_tunnel_get_dsfield(ip_hdr(skb), skb);
                *use_cache = false;
        }

        return dsfield;
}

static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
                           struct geneve_dev *geneve,
                           const struct ip_tunnel_info *info)
{
        struct geneve_sock *gs4 = rcu_dereference(geneve->sock4);
        const struct ip_tunnel_key *key = &info->key;
        struct rtable *rt;
        bool use_cache;
        __u8 tos, ttl;
        __be16 df = 0;
        __be32 saddr;
        __be16 sport;
        int err;

        if (skb_vlan_inet_prepare(skb, geneve->cfg.inner_proto_inherit))
                return -EINVAL;

        if (!gs4)
                return -EIO;

        use_cache = ip_tunnel_dst_cache_usable(skb, info);
        tos = geneve_get_dsfield(skb, dev, info, &use_cache);
        sport = udp_flow_src_port(geneve->net, skb,
                                  geneve->cfg.port_min,
                                  geneve->cfg.port_max, true);

        rt = udp_tunnel_dst_lookup(skb, dev, geneve->net, 0, &saddr,
                                   &info->key,
                                   sport, geneve->cfg.info.key.tp_dst, tos,
                                   use_cache ?
                                   (struct dst_cache *)&info->dst_cache : NULL);
        if (IS_ERR(rt))
                return PTR_ERR(rt);

        err = skb_tunnel_check_pmtu(skb, &rt->dst,
                                    GENEVE_IPV4_HLEN + info->options_len +
                                    geneve_build_gro_hint_opt(geneve, skb),
                                    netif_is_any_bridge_port(dev));
        if (err < 0) {
                dst_release(&rt->dst);
                return err;
        } else if (err) {
                struct ip_tunnel_info *info;

                info = skb_tunnel_info(skb);
                if (info) {
                        struct ip_tunnel_info *unclone;

                        unclone = skb_tunnel_info_unclone(skb);
                        if (unlikely(!unclone)) {
                                dst_release(&rt->dst);
                                return -ENOMEM;
                        }

                        unclone->key.u.ipv4.dst = saddr;
                        unclone->key.u.ipv4.src = info->key.u.ipv4.dst;
                }

                if (!pskb_may_pull(skb, ETH_HLEN)) {
                        dst_release(&rt->dst);
                        return -EINVAL;
                }

                skb->protocol = eth_type_trans(skb, geneve->dev);
                __netif_rx(skb);
                dst_release(&rt->dst);
                return -EMSGSIZE;
        }

        tos = ip_tunnel_ecn_encap(tos, ip_hdr(skb), skb);
        if (geneve->cfg.collect_md) {
                ttl = key->ttl;

                df = test_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, key->tun_flags) ?
                     htons(IP_DF) : 0;
        } else {
                if (geneve->cfg.ttl_inherit)
                        ttl = ip_tunnel_get_ttl(ip_hdr(skb), skb);
                else
                        ttl = key->ttl;
                ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);

                if (geneve->cfg.df == GENEVE_DF_SET) {
                        df = htons(IP_DF);
                } else if (geneve->cfg.df == GENEVE_DF_INHERIT) {
                        struct ethhdr *eth = skb_eth_hdr(skb);

                        if (ntohs(eth->h_proto) == ETH_P_IPV6) {
                                df = htons(IP_DF);
                        } else if (ntohs(eth->h_proto) == ETH_P_IP) {
                                struct iphdr *iph = ip_hdr(skb);

                                if (iph->frag_off & htons(IP_DF))
                                        df = htons(IP_DF);
                        }
                }
        }

        err = geneve_build_skb(&rt->dst, skb, info, geneve,
                               sizeof(struct iphdr));
        if (unlikely(err))
                return err;

        udp_tunnel_xmit_skb(rt, gs4->sock->sk, skb, saddr, info->key.u.ipv4.dst,
                            tos, ttl, df, sport, geneve->cfg.info.key.tp_dst,
                            !net_eq(geneve->net, dev_net(geneve->dev)),
                            !test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags),
                            0);
        return 0;
}

#if IS_ENABLED(CONFIG_IPV6)
static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
                            struct geneve_dev *geneve,
                            const struct ip_tunnel_info *info)
{
        struct geneve_sock *gs6 = rcu_dereference(geneve->sock6);
        const struct ip_tunnel_key *key = &info->key;
        struct dst_entry *dst = NULL;
        struct in6_addr saddr;
        bool use_cache;
        __u8 prio, ttl;
        __be16 sport;
        int err;

        if (skb_vlan_inet_prepare(skb, geneve->cfg.inner_proto_inherit))
                return -EINVAL;

        if (!gs6)
                return -EIO;

        use_cache = ip_tunnel_dst_cache_usable(skb, info);
        prio = geneve_get_dsfield(skb, dev, info, &use_cache);
        sport = udp_flow_src_port(geneve->net, skb,
                                  geneve->cfg.port_min,
                                  geneve->cfg.port_max, true);

        dst = udp_tunnel6_dst_lookup(skb, dev, geneve->net, gs6->sock, 0,
                                     &saddr, key, sport,
                                     geneve->cfg.info.key.tp_dst, prio,
                                     use_cache ?
                                     (struct dst_cache *)&info->dst_cache : NULL);
        if (IS_ERR(dst))
                return PTR_ERR(dst);

        err = skb_tunnel_check_pmtu(skb, dst,
                                    GENEVE_IPV6_HLEN + info->options_len +
                                    geneve_build_gro_hint_opt(geneve, skb),
                                    netif_is_any_bridge_port(dev));
        if (err < 0) {
                dst_release(dst);
                return err;
        } else if (err) {
                struct ip_tunnel_info *info = skb_tunnel_info(skb);

                if (info) {
                        struct ip_tunnel_info *unclone;

                        unclone = skb_tunnel_info_unclone(skb);
                        if (unlikely(!unclone)) {
                                dst_release(dst);
                                return -ENOMEM;
                        }

                        unclone->key.u.ipv6.dst = saddr;
                        unclone->key.u.ipv6.src = info->key.u.ipv6.dst;
                }

                if (!pskb_may_pull(skb, ETH_HLEN)) {
                        dst_release(dst);
                        return -EINVAL;
                }

                skb->protocol = eth_type_trans(skb, geneve->dev);
                __netif_rx(skb);
                dst_release(dst);
                return -EMSGSIZE;
        }

        prio = ip_tunnel_ecn_encap(prio, ip_hdr(skb), skb);
        if (geneve->cfg.collect_md) {
                ttl = key->ttl;
        } else {
                if (geneve->cfg.ttl_inherit)
                        ttl = ip_tunnel_get_ttl(ip_hdr(skb), skb);
                else
                        ttl = key->ttl;
                ttl = ttl ? : ip6_dst_hoplimit(dst);
        }
        err = geneve_build_skb(dst, skb, info, geneve, sizeof(struct ipv6hdr));
        if (unlikely(err))
                return err;

        udp_tunnel6_xmit_skb(dst, gs6->sock->sk, skb, dev,
                             &saddr, &key->u.ipv6.dst, prio, ttl,
                             info->key.label, sport, geneve->cfg.info.key.tp_dst,
                             !test_bit(IP_TUNNEL_CSUM_BIT,
                                       info->key.tun_flags),
                             0);
        return 0;
}
#endif

static netdev_tx_t geneve_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct geneve_dev *geneve = netdev_priv(dev);
        struct ip_tunnel_info *info = NULL;
        int err;

        if (geneve->cfg.collect_md) {
                info = skb_tunnel_info(skb);
                if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
                        netdev_dbg(dev, "no tunnel metadata\n");
                        dev_kfree_skb(skb);
                        dev_dstats_tx_dropped(dev);
                        return NETDEV_TX_OK;
                }
        } else {
                info = &geneve->cfg.info;
        }

        rcu_read_lock();
#if IS_ENABLED(CONFIG_IPV6)
        if (info->mode & IP_TUNNEL_INFO_IPV6)
                err = geneve6_xmit_skb(skb, dev, geneve, info);
        else
#endif
                err = geneve_xmit_skb(skb, dev, geneve, info);
        rcu_read_unlock();

        if (likely(!err))
                return NETDEV_TX_OK;

        if (err != -EMSGSIZE)
                dev_kfree_skb(skb);

        if (err == -ELOOP)
                DEV_STATS_INC(dev, collisions);
        else if (err == -ENETUNREACH)
                DEV_STATS_INC(dev, tx_carrier_errors);

        DEV_STATS_INC(dev, tx_errors);
        return NETDEV_TX_OK;
}

static int geneve_change_mtu(struct net_device *dev, int new_mtu)
{
        if (new_mtu > dev->max_mtu)
                new_mtu = dev->max_mtu;
        else if (new_mtu < dev->min_mtu)
                new_mtu = dev->min_mtu;

        WRITE_ONCE(dev->mtu, new_mtu);
        return 0;
}

static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
{
        struct ip_tunnel_info *info = skb_tunnel_info(skb);
        struct geneve_dev *geneve = netdev_priv(dev);
        __be16 sport;

        if (ip_tunnel_info_af(info) == AF_INET) {
                struct rtable *rt;
                struct geneve_sock *gs4 = rcu_dereference(geneve->sock4);
                bool use_cache;
                __be32 saddr;
                u8 tos;

                if (!gs4)
                        return -EIO;

                use_cache = ip_tunnel_dst_cache_usable(skb, info);
                tos = geneve_get_dsfield(skb, dev, info, &use_cache);
                sport = udp_flow_src_port(geneve->net, skb,
                                          geneve->cfg.port_min,
                                          geneve->cfg.port_max, true);

                rt = udp_tunnel_dst_lookup(skb, dev, geneve->net, 0, &saddr,
                                           &info->key,
                                           sport, geneve->cfg.info.key.tp_dst,
                                           tos,
                                           use_cache ? &info->dst_cache : NULL);
                if (IS_ERR(rt))
                        return PTR_ERR(rt);

                ip_rt_put(rt);
                info->key.u.ipv4.src = saddr;
#if IS_ENABLED(CONFIG_IPV6)
        } else if (ip_tunnel_info_af(info) == AF_INET6) {
                struct dst_entry *dst;
                struct geneve_sock *gs6 = rcu_dereference(geneve->sock6);
                struct in6_addr saddr;
                bool use_cache;
                u8 prio;

                if (!gs6)
                        return -EIO;

                use_cache = ip_tunnel_dst_cache_usable(skb, info);
                prio = geneve_get_dsfield(skb, dev, info, &use_cache);
                sport = udp_flow_src_port(geneve->net, skb,
                                          geneve->cfg.port_min,
                                          geneve->cfg.port_max, true);

                dst = udp_tunnel6_dst_lookup(skb, dev, geneve->net, gs6->sock, 0,
                                             &saddr, &info->key, sport,
                                             geneve->cfg.info.key.tp_dst, prio,
                                             use_cache ? &info->dst_cache : NULL);
                if (IS_ERR(dst))
                        return PTR_ERR(dst);

                dst_release(dst);
                info->key.u.ipv6.src = saddr;
#endif
        } else {
                return -EINVAL;
        }

        info->key.tp_src = sport;
        info->key.tp_dst = geneve->cfg.info.key.tp_dst;
        return 0;
}

static const struct net_device_ops geneve_netdev_ops = {
        .ndo_init               = geneve_init,
        .ndo_uninit             = geneve_uninit,
        .ndo_open               = geneve_open,
        .ndo_stop               = geneve_stop,
        .ndo_start_xmit         = geneve_xmit,
        .ndo_change_mtu         = geneve_change_mtu,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_set_mac_address    = eth_mac_addr,
        .ndo_fill_metadata_dst  = geneve_fill_metadata_dst,
};

static void geneve_get_drvinfo(struct net_device *dev,
                               struct ethtool_drvinfo *drvinfo)
{
        strscpy(drvinfo->version, GENEVE_NETDEV_VER, sizeof(drvinfo->version));
        strscpy(drvinfo->driver, "geneve", sizeof(drvinfo->driver));
}

static const struct ethtool_ops geneve_ethtool_ops = {
        .get_drvinfo    = geneve_get_drvinfo,
        .get_link       = ethtool_op_get_link,
};

/* Info for udev, that this is a virtual tunnel endpoint */
static const struct device_type geneve_type = {
        .name = "geneve",
};

/* Calls the ndo_udp_tunnel_add of the caller in order to
 * supply the listening GENEVE udp ports. Callers are expected
 * to implement the ndo_udp_tunnel_add.
 */
static void geneve_offload_rx_ports(struct net_device *dev, bool push)
{
        struct net *net = dev_net(dev);
        struct geneve_net *gn = net_generic(net, geneve_net_id);
        struct geneve_sock *gs;

        ASSERT_RTNL();

        list_for_each_entry(gs, &gn->sock_list, list) {
                if (push) {
                        udp_tunnel_push_rx_port(dev, gs->sock,
                                                UDP_TUNNEL_TYPE_GENEVE);
                } else {
                        udp_tunnel_drop_rx_port(dev, gs->sock,
                                                UDP_TUNNEL_TYPE_GENEVE);
                }
        }
}

/* Initialize the device structure. */
static void geneve_setup(struct net_device *dev)
{
        ether_setup(dev);

        dev->netdev_ops = &geneve_netdev_ops;
        dev->ethtool_ops = &geneve_ethtool_ops;
        dev->needs_free_netdev = true;

        SET_NETDEV_DEVTYPE(dev, &geneve_type);

        dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
        dev->features    |= NETIF_F_RXCSUM;
        dev->features    |= NETIF_F_GSO_SOFTWARE;

        /* Partial features are disabled by default. */
        dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
        dev->hw_features |= NETIF_F_RXCSUM;
        dev->hw_features |= NETIF_F_GSO_SOFTWARE;
        dev->hw_features |= UDP_TUNNEL_PARTIAL_FEATURES;
        dev->hw_features |= NETIF_F_GSO_PARTIAL;

        dev->hw_enc_features = dev->hw_features;
        dev->gso_partial_features = UDP_TUNNEL_PARTIAL_FEATURES;
        dev->mangleid_features = NETIF_F_GSO_PARTIAL;

        dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS;
        /* MTU range: 68 - (something less than 65535) */
        dev->min_mtu = ETH_MIN_MTU;
        /* The max_mtu calculation does not take account of GENEVE
         * options, to avoid excluding potentially valid
         * configurations. This will be further reduced by IPvX hdr size.
         */
        dev->max_mtu = IP_MAX_MTU - GENEVE_BASE_HLEN - dev->hard_header_len;

        netif_keep_dst(dev);
        dev->priv_flags &= ~IFF_TX_SKB_SHARING;
        dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
        dev->lltx = true;
        eth_hw_addr_random(dev);
}

static const struct nla_policy geneve_policy[IFLA_GENEVE_MAX + 1] = {
        [IFLA_GENEVE_UNSPEC]            = { .strict_start_type = IFLA_GENEVE_INNER_PROTO_INHERIT },
        [IFLA_GENEVE_ID]                = { .type = NLA_U32 },
        [IFLA_GENEVE_REMOTE]            = { .len = sizeof_field(struct iphdr, daddr) },
        [IFLA_GENEVE_REMOTE6]           = { .len = sizeof(struct in6_addr) },
        [IFLA_GENEVE_TTL]               = { .type = NLA_U8 },
        [IFLA_GENEVE_TOS]               = { .type = NLA_U8 },
        [IFLA_GENEVE_LABEL]             = { .type = NLA_U32 },
        [IFLA_GENEVE_PORT]              = { .type = NLA_U16 },
        [IFLA_GENEVE_COLLECT_METADATA]  = { .type = NLA_FLAG },
        [IFLA_GENEVE_UDP_CSUM]          = { .type = NLA_U8 },
        [IFLA_GENEVE_UDP_ZERO_CSUM6_TX] = { .type = NLA_U8 },
        [IFLA_GENEVE_UDP_ZERO_CSUM6_RX] = { .type = NLA_U8 },
        [IFLA_GENEVE_TTL_INHERIT]       = { .type = NLA_U8 },
        [IFLA_GENEVE_DF]                = { .type = NLA_U8 },
        [IFLA_GENEVE_INNER_PROTO_INHERIT]       = { .type = NLA_FLAG },
        [IFLA_GENEVE_PORT_RANGE]        = NLA_POLICY_EXACT_LEN(sizeof(struct ifla_geneve_port_range)),
        [IFLA_GENEVE_GRO_HINT]          = { .type = NLA_FLAG },
};

static int geneve_validate(struct nlattr *tb[], struct nlattr *data[],
                           struct netlink_ext_ack *extack)
{
        if (tb[IFLA_ADDRESS]) {
                if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
                        NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_ADDRESS],
                                            "Provided link layer address is not Ethernet");
                        return -EINVAL;
                }

                if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
                        NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_ADDRESS],
                                            "Provided Ethernet address is not unicast");
                        return -EADDRNOTAVAIL;
                }
        }

        if (!data) {
                NL_SET_ERR_MSG(extack,
                               "Not enough attributes provided to perform the operation");
                return -EINVAL;
        }

        if (data[IFLA_GENEVE_ID]) {
                __u32 vni =  nla_get_u32(data[IFLA_GENEVE_ID]);

                if (vni >= GENEVE_N_VID) {
                        NL_SET_ERR_MSG_ATTR(extack, data[IFLA_GENEVE_ID],
                                            "Geneve ID must be lower than 16777216");
                        return -ERANGE;
                }
        }

        if (data[IFLA_GENEVE_DF]) {
                enum ifla_geneve_df df = nla_get_u8(data[IFLA_GENEVE_DF]);

                if (df < 0 || df > GENEVE_DF_MAX) {
                        NL_SET_ERR_MSG_ATTR(extack, data[IFLA_GENEVE_DF],
                                            "Invalid DF attribute");
                        return -EINVAL;
                }
        }

        if (data[IFLA_GENEVE_PORT_RANGE]) {
                const struct ifla_geneve_port_range *p;

                p = nla_data(data[IFLA_GENEVE_PORT_RANGE]);
                if (ntohs(p->high) < ntohs(p->low)) {
                        NL_SET_ERR_MSG_ATTR(extack, data[IFLA_GENEVE_PORT_RANGE],
                                            "Invalid source port range");
                        return -EINVAL;
                }
        }

        return 0;
}

static struct geneve_dev *geneve_find_dev(struct geneve_net *gn,
                                          const struct ip_tunnel_info *info,
                                          bool *tun_on_same_port,
                                          bool *tun_collect_md)
{
        struct geneve_dev *geneve, *t = NULL;

        *tun_on_same_port = false;
        *tun_collect_md = false;
        list_for_each_entry(geneve, &gn->geneve_list, next) {
                if (info->key.tp_dst == geneve->cfg.info.key.tp_dst) {
                        *tun_collect_md = geneve->cfg.collect_md;
                        *tun_on_same_port = true;
                }
                if (info->key.tun_id == geneve->cfg.info.key.tun_id &&
                    info->key.tp_dst == geneve->cfg.info.key.tp_dst &&
                    !memcmp(&info->key.u, &geneve->cfg.info.key.u, sizeof(info->key.u)))
                        t = geneve;
        }
        return t;
}

static bool is_tnl_info_zero(const struct ip_tunnel_info *info)
{
        return !(info->key.tun_id || info->key.tos ||
                 !ip_tunnel_flags_empty(info->key.tun_flags) ||
                 info->key.ttl || info->key.label || info->key.tp_src ||
                 memchr_inv(&info->key.u, 0, sizeof(info->key.u)));
}

static bool geneve_dst_addr_equal(struct ip_tunnel_info *a,
                                  struct ip_tunnel_info *b)
{
        if (ip_tunnel_info_af(a) == AF_INET)
                return a->key.u.ipv4.dst == b->key.u.ipv4.dst;
        else
                return ipv6_addr_equal(&a->key.u.ipv6.dst, &b->key.u.ipv6.dst);
}

static int geneve_configure(struct net *net, struct net_device *dev,
                            struct netlink_ext_ack *extack,
                            const struct geneve_config *cfg)
{
        struct geneve_net *gn = net_generic(net, geneve_net_id);
        struct geneve_dev *t, *geneve = netdev_priv(dev);
        const struct ip_tunnel_info *info = &cfg->info;
        bool tun_collect_md, tun_on_same_port;
        int err, encap_len;

        if (cfg->collect_md && !is_tnl_info_zero(info)) {
                NL_SET_ERR_MSG(extack,
                               "Device is externally controlled, so attributes (VNI, Port, and so on) must not be specified");
                return -EINVAL;
        }

        geneve->net = net;
        geneve->dev = dev;

        t = geneve_find_dev(gn, info, &tun_on_same_port, &tun_collect_md);
        if (t)
                return -EBUSY;

        /* make enough headroom for basic scenario */
        encap_len = GENEVE_BASE_HLEN + ETH_HLEN;
        if (!cfg->collect_md && ip_tunnel_info_af(info) == AF_INET) {
                encap_len += sizeof(struct iphdr);
                dev->max_mtu -= sizeof(struct iphdr);
        } else {
                encap_len += sizeof(struct ipv6hdr);
                dev->max_mtu -= sizeof(struct ipv6hdr);
        }
        dev->needed_headroom = encap_len + ETH_HLEN;

        if (cfg->collect_md) {
                if (tun_on_same_port) {
                        NL_SET_ERR_MSG(extack,
                                       "There can be only one externally controlled device on a destination port");
                        return -EPERM;
                }
        } else {
                if (tun_collect_md) {
                        NL_SET_ERR_MSG(extack,
                                       "There already exists an externally controlled device on this destination port");
                        return -EPERM;
                }
        }

        dst_cache_reset(&geneve->cfg.info.dst_cache);
        memcpy(&geneve->cfg, cfg, sizeof(*cfg));

        if (geneve->cfg.inner_proto_inherit) {
                dev->header_ops = NULL;
                dev->type = ARPHRD_NONE;
                dev->hard_header_len = 0;
                dev->addr_len = 0;
                dev->flags = IFF_POINTOPOINT | IFF_NOARP;
        }

        err = register_netdevice(dev);
        if (err)
                return err;

        list_add(&geneve->next, &gn->geneve_list);
        return 0;
}

static void init_tnl_info(struct ip_tunnel_info *info, __u16 dst_port)
{
        memset(info, 0, sizeof(*info));
        info->key.tp_dst = htons(dst_port);
}

static int geneve_nl2info(struct nlattr *tb[], struct nlattr *data[],
                          struct netlink_ext_ack *extack,
                          struct geneve_config *cfg, bool changelink)
{
        struct ip_tunnel_info *info = &cfg->info;
        int attrtype;

        if (data[IFLA_GENEVE_REMOTE] && data[IFLA_GENEVE_REMOTE6]) {
                NL_SET_ERR_MSG(extack,
                               "Cannot specify both IPv4 and IPv6 Remote addresses");
                return -EINVAL;
        }

        if (data[IFLA_GENEVE_REMOTE]) {
                if (changelink && (ip_tunnel_info_af(info) == AF_INET6)) {
                        attrtype = IFLA_GENEVE_REMOTE;
                        goto change_notsup;
                }

                info->key.u.ipv4.dst =
                        nla_get_in_addr(data[IFLA_GENEVE_REMOTE]);

                if (ipv4_is_multicast(info->key.u.ipv4.dst)) {
                        NL_SET_ERR_MSG_ATTR(extack, data[IFLA_GENEVE_REMOTE],
                                            "Remote IPv4 address cannot be Multicast");
                        return -EINVAL;
                }
        }

        if (data[IFLA_GENEVE_REMOTE6]) {
#if IS_ENABLED(CONFIG_IPV6)
                if (changelink && (ip_tunnel_info_af(info) == AF_INET)) {
                        attrtype = IFLA_GENEVE_REMOTE6;
                        goto change_notsup;
                }

                info->mode = IP_TUNNEL_INFO_IPV6;
                info->key.u.ipv6.dst =
                        nla_get_in6_addr(data[IFLA_GENEVE_REMOTE6]);

                if (ipv6_addr_type(&info->key.u.ipv6.dst) &
                    IPV6_ADDR_LINKLOCAL) {
                        NL_SET_ERR_MSG_ATTR(extack, data[IFLA_GENEVE_REMOTE6],
                                            "Remote IPv6 address cannot be link-local");
                        return -EINVAL;
                }
                if (ipv6_addr_is_multicast(&info->key.u.ipv6.dst)) {
                        NL_SET_ERR_MSG_ATTR(extack, data[IFLA_GENEVE_REMOTE6],
                                            "Remote IPv6 address cannot be Multicast");
                        return -EINVAL;
                }
                __set_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
                cfg->use_udp6_rx_checksums = true;
#else
                NL_SET_ERR_MSG_ATTR(extack, data[IFLA_GENEVE_REMOTE6],
                                    "IPv6 support not enabled in the kernel");
                return -EPFNOSUPPORT;
#endif
        }

        if (data[IFLA_GENEVE_ID]) {
                __u32 vni;
                __u8 tvni[3];
                __be64 tunid;

                vni = nla_get_u32(data[IFLA_GENEVE_ID]);
                tvni[0] = (vni & 0x00ff0000) >> 16;
                tvni[1] = (vni & 0x0000ff00) >> 8;
                tvni[2] =  vni & 0x000000ff;

                tunid = vni_to_tunnel_id(tvni);
                if (changelink && (tunid != info->key.tun_id)) {
                        attrtype = IFLA_GENEVE_ID;
                        goto change_notsup;
                }
                info->key.tun_id = tunid;
        }

        if (data[IFLA_GENEVE_TTL_INHERIT]) {
                if (nla_get_u8(data[IFLA_GENEVE_TTL_INHERIT]))
                        cfg->ttl_inherit = true;
                else
                        cfg->ttl_inherit = false;
        } else if (data[IFLA_GENEVE_TTL]) {
                info->key.ttl = nla_get_u8(data[IFLA_GENEVE_TTL]);
                cfg->ttl_inherit = false;
        }

        if (data[IFLA_GENEVE_TOS])
                info->key.tos = nla_get_u8(data[IFLA_GENEVE_TOS]);

        if (data[IFLA_GENEVE_DF])
                cfg->df = nla_get_u8(data[IFLA_GENEVE_DF]);

        if (data[IFLA_GENEVE_LABEL]) {
                info->key.label = nla_get_be32(data[IFLA_GENEVE_LABEL]) &
                                  IPV6_FLOWLABEL_MASK;
                if (info->key.label && (!(info->mode & IP_TUNNEL_INFO_IPV6))) {
                        NL_SET_ERR_MSG_ATTR(extack, data[IFLA_GENEVE_LABEL],
                                            "Label attribute only applies for IPv6 Geneve devices");
                        return -EINVAL;
                }
        }

        if (data[IFLA_GENEVE_PORT]) {
                if (changelink) {
                        attrtype = IFLA_GENEVE_PORT;
                        goto change_notsup;
                }
                info->key.tp_dst = nla_get_be16(data[IFLA_GENEVE_PORT]);
        }

        if (data[IFLA_GENEVE_PORT_RANGE]) {
                const struct ifla_geneve_port_range *p;

                if (changelink) {
                        attrtype = IFLA_GENEVE_PORT_RANGE;
                        goto change_notsup;
                }
                p = nla_data(data[IFLA_GENEVE_PORT_RANGE]);
                cfg->port_min = ntohs(p->low);
                cfg->port_max = ntohs(p->high);
        }

        if (data[IFLA_GENEVE_COLLECT_METADATA]) {
                if (changelink) {
                        attrtype = IFLA_GENEVE_COLLECT_METADATA;
                        goto change_notsup;
                }
                cfg->collect_md = true;
        }

        if (data[IFLA_GENEVE_UDP_CSUM]) {
                if (changelink) {
                        attrtype = IFLA_GENEVE_UDP_CSUM;
                        goto change_notsup;
                }
                if (nla_get_u8(data[IFLA_GENEVE_UDP_CSUM]))
                        __set_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
        }

        if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX]) {
#if IS_ENABLED(CONFIG_IPV6)
                if (changelink) {
                        attrtype = IFLA_GENEVE_UDP_ZERO_CSUM6_TX;
                        goto change_notsup;
                }
                if (nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX]))
                        __clear_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
#else
                NL_SET_ERR_MSG_ATTR(extack, data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX],
                                    "IPv6 support not enabled in the kernel");
                return -EPFNOSUPPORT;
#endif
        }

        if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX]) {
#if IS_ENABLED(CONFIG_IPV6)
                if (changelink) {
                        attrtype = IFLA_GENEVE_UDP_ZERO_CSUM6_RX;
                        goto change_notsup;
                }
                if (nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX]))
                        cfg->use_udp6_rx_checksums = false;
#else
                NL_SET_ERR_MSG_ATTR(extack, data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX],
                                    "IPv6 support not enabled in the kernel");
                return -EPFNOSUPPORT;
#endif
        }

        if (data[IFLA_GENEVE_INNER_PROTO_INHERIT]) {
                if (changelink) {
                        attrtype = IFLA_GENEVE_INNER_PROTO_INHERIT;
                        goto change_notsup;
                }
                cfg->inner_proto_inherit = true;
        }

        if (data[IFLA_GENEVE_GRO_HINT]) {
                if (changelink) {
                        attrtype = IFLA_GENEVE_GRO_HINT;
                        goto change_notsup;
                }
                cfg->gro_hint = true;
        }

        return 0;
change_notsup:
        NL_SET_ERR_MSG_ATTR(extack, data[attrtype],
                            "Changing VNI, Port, endpoint IP address family, external, inner_proto_inherit, gro_hint and UDP checksum attributes are not supported");
        return -EOPNOTSUPP;
}

static void geneve_link_config(struct net_device *dev,
                               struct ip_tunnel_info *info, struct nlattr *tb[])
{
        struct geneve_dev *geneve = netdev_priv(dev);
        int ldev_mtu = 0;

        if (tb[IFLA_MTU]) {
                geneve_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
                return;
        }

        switch (ip_tunnel_info_af(info)) {
        case AF_INET: {
                struct flowi4 fl4 = { .daddr = info->key.u.ipv4.dst };
                struct rtable *rt = ip_route_output_key(geneve->net, &fl4);

                if (!IS_ERR(rt) && rt->dst.dev) {
                        ldev_mtu = rt->dst.dev->mtu - GENEVE_IPV4_HLEN;
                        ip_rt_put(rt);
                }
                break;
        }
#if IS_ENABLED(CONFIG_IPV6)
        case AF_INET6: {
                struct rt6_info *rt;

                if (!__in6_dev_get(dev))
                        break;

                rt = rt6_lookup(geneve->net, &info->key.u.ipv6.dst, NULL, 0,
                                NULL, 0);

                if (rt && rt->dst.dev)
                        ldev_mtu = rt->dst.dev->mtu - GENEVE_IPV6_HLEN;
                ip6_rt_put(rt);
                break;
        }
#endif
        }

        if (ldev_mtu <= 0)
                return;

        geneve_change_mtu(dev, ldev_mtu - info->options_len);
}

static int geneve_newlink(struct net_device *dev,
                          struct rtnl_newlink_params *params,
                          struct netlink_ext_ack *extack)
{
        struct net *link_net = rtnl_newlink_link_net(params);
        struct nlattr **data = params->data;
        struct nlattr **tb = params->tb;
        struct geneve_config cfg = {
                .df = GENEVE_DF_UNSET,
                .use_udp6_rx_checksums = false,
                .ttl_inherit = false,
                .collect_md = false,
                .port_min = 1,
                .port_max = USHRT_MAX,
        };
        int err;

        init_tnl_info(&cfg.info, GENEVE_UDP_PORT);
        err = geneve_nl2info(tb, data, extack, &cfg, false);
        if (err)
                return err;

        err = geneve_configure(link_net, dev, extack, &cfg);
        if (err)
                return err;

        geneve_link_config(dev, &cfg.info, tb);

        return 0;
}

/* Quiesces the geneve device data path for both TX and RX.
 *
 * On transmit geneve checks for non-NULL geneve_sock before it proceeds.
 * So, if we set that socket to NULL under RCU and wait for synchronize_net()
 * to complete for the existing set of in-flight packets to be transmitted,
 * then we would have quiesced the transmit data path. All the future packets
 * will get dropped until we unquiesce the data path.
 *
 * On receive geneve dereference the geneve_sock stashed in the socket. So,
 * if we set that to NULL under RCU and wait for synchronize_net() to
 * complete, then we would have quiesced the receive data path.
 */
static void geneve_quiesce(struct geneve_dev *geneve, struct geneve_sock **gs4,
                           struct geneve_sock **gs6)
{
        *gs4 = rtnl_dereference(geneve->sock4);
        rcu_assign_pointer(geneve->sock4, NULL);
        if (*gs4)
                rcu_assign_sk_user_data((*gs4)->sock->sk, NULL);
#if IS_ENABLED(CONFIG_IPV6)
        *gs6 = rtnl_dereference(geneve->sock6);
        rcu_assign_pointer(geneve->sock6, NULL);
        if (*gs6)
                rcu_assign_sk_user_data((*gs6)->sock->sk, NULL);
#else
        *gs6 = NULL;
#endif
        synchronize_net();
}

/* Resumes the geneve device data path for both TX and RX. */
static void geneve_unquiesce(struct geneve_dev *geneve, struct geneve_sock *gs4,
                             struct geneve_sock __maybe_unused *gs6)
{
        rcu_assign_pointer(geneve->sock4, gs4);
        if (gs4)
                rcu_assign_sk_user_data(gs4->sock->sk, gs4);
#if IS_ENABLED(CONFIG_IPV6)
        rcu_assign_pointer(geneve->sock6, gs6);
        if (gs6)
                rcu_assign_sk_user_data(gs6->sock->sk, gs6);
#endif
        synchronize_net();
}

static int geneve_changelink(struct net_device *dev, struct nlattr *tb[],
                             struct nlattr *data[],
                             struct netlink_ext_ack *extack)
{
        struct geneve_dev *geneve = netdev_priv(dev);
        struct geneve_sock *gs4, *gs6;
        struct geneve_config cfg;
        int err;

        /* If the geneve device is configured for metadata (or externally
         * controlled, for example, OVS), then nothing can be changed.
         */
        if (geneve->cfg.collect_md)
                return -EOPNOTSUPP;

        /* Start with the existing info. */
        memcpy(&cfg, &geneve->cfg, sizeof(cfg));
        err = geneve_nl2info(tb, data, extack, &cfg, true);
        if (err)
                return err;

        if (!geneve_dst_addr_equal(&geneve->cfg.info, &cfg.info)) {
                dst_cache_reset(&cfg.info.dst_cache);
                geneve_link_config(dev, &cfg.info, tb);
        }

        geneve_quiesce(geneve, &gs4, &gs6);
        memcpy(&geneve->cfg, &cfg, sizeof(cfg));
        geneve_unquiesce(geneve, gs4, gs6);

        return 0;
}

static void geneve_dellink(struct net_device *dev, struct list_head *head)
{
        struct geneve_dev *geneve = netdev_priv(dev);

        list_del(&geneve->next);
        unregister_netdevice_queue(dev, head);
}

static size_t geneve_get_size(const struct net_device *dev)
{
        return nla_total_size(sizeof(__u32)) +  /* IFLA_GENEVE_ID */
                nla_total_size(sizeof(struct in6_addr)) + /* IFLA_GENEVE_REMOTE{6} */
                nla_total_size(sizeof(__u8)) +  /* IFLA_GENEVE_TTL */
                nla_total_size(sizeof(__u8)) +  /* IFLA_GENEVE_TOS */
                nla_total_size(sizeof(__u8)) +  /* IFLA_GENEVE_DF */
                nla_total_size(sizeof(__be32)) +  /* IFLA_GENEVE_LABEL */
                nla_total_size(sizeof(__be16)) +  /* IFLA_GENEVE_PORT */
                nla_total_size(0) +      /* IFLA_GENEVE_COLLECT_METADATA */
                nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_CSUM */
                nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_ZERO_CSUM6_TX */
                nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_ZERO_CSUM6_RX */
                nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_TTL_INHERIT */
                nla_total_size(0) +      /* IFLA_GENEVE_INNER_PROTO_INHERIT */
                nla_total_size(sizeof(struct ifla_geneve_port_range)) + /* IFLA_GENEVE_PORT_RANGE */
                nla_total_size(0) +      /* IFLA_GENEVE_GRO_HINT */
                0;
}

static int geneve_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
        struct geneve_dev *geneve = netdev_priv(dev);
        struct ip_tunnel_info *info = &geneve->cfg.info;
        bool ttl_inherit = geneve->cfg.ttl_inherit;
        bool metadata = geneve->cfg.collect_md;
        struct ifla_geneve_port_range ports = {
                .low    = htons(geneve->cfg.port_min),
                .high   = htons(geneve->cfg.port_max),
        };
        __u8 tmp_vni[3];
        __u32 vni;

        tunnel_id_to_vni(info->key.tun_id, tmp_vni);
        vni = (tmp_vni[0] << 16) | (tmp_vni[1] << 8) | tmp_vni[2];
        if (nla_put_u32(skb, IFLA_GENEVE_ID, vni))
                goto nla_put_failure;

        if (!metadata && ip_tunnel_info_af(info) == AF_INET) {
                if (nla_put_in_addr(skb, IFLA_GENEVE_REMOTE,
                                    info->key.u.ipv4.dst))
                        goto nla_put_failure;
                if (nla_put_u8(skb, IFLA_GENEVE_UDP_CSUM,
                               test_bit(IP_TUNNEL_CSUM_BIT,
                                        info->key.tun_flags)))
                        goto nla_put_failure;

#if IS_ENABLED(CONFIG_IPV6)
        } else if (!metadata) {
                if (nla_put_in6_addr(skb, IFLA_GENEVE_REMOTE6,
                                     &info->key.u.ipv6.dst))
                        goto nla_put_failure;
                if (nla_put_u8(skb, IFLA_GENEVE_UDP_ZERO_CSUM6_TX,
                               !test_bit(IP_TUNNEL_CSUM_BIT,
                                         info->key.tun_flags)))
                        goto nla_put_failure;
#endif
        }

        if (nla_put_u8(skb, IFLA_GENEVE_TTL, info->key.ttl) ||
            nla_put_u8(skb, IFLA_GENEVE_TOS, info->key.tos) ||
            nla_put_be32(skb, IFLA_GENEVE_LABEL, info->key.label))
                goto nla_put_failure;

        if (nla_put_u8(skb, IFLA_GENEVE_DF, geneve->cfg.df))
                goto nla_put_failure;

        if (nla_put_be16(skb, IFLA_GENEVE_PORT, info->key.tp_dst))
                goto nla_put_failure;

        if (metadata && nla_put_flag(skb, IFLA_GENEVE_COLLECT_METADATA))
                goto nla_put_failure;

#if IS_ENABLED(CONFIG_IPV6)
        if (nla_put_u8(skb, IFLA_GENEVE_UDP_ZERO_CSUM6_RX,
                       !geneve->cfg.use_udp6_rx_checksums))
                goto nla_put_failure;
#endif

        if (nla_put_u8(skb, IFLA_GENEVE_TTL_INHERIT, ttl_inherit))
                goto nla_put_failure;

        if (geneve->cfg.inner_proto_inherit &&
            nla_put_flag(skb, IFLA_GENEVE_INNER_PROTO_INHERIT))
                goto nla_put_failure;

        if (nla_put(skb, IFLA_GENEVE_PORT_RANGE, sizeof(ports), &ports))
                goto nla_put_failure;

        if (geneve->cfg.gro_hint &&
            nla_put_flag(skb, IFLA_GENEVE_GRO_HINT))
                goto nla_put_failure;

        return 0;

nla_put_failure:
        return -EMSGSIZE;
}

static struct rtnl_link_ops geneve_link_ops __read_mostly = {
        .kind           = "geneve",
        .maxtype        = IFLA_GENEVE_MAX,
        .policy         = geneve_policy,
        .priv_size      = sizeof(struct geneve_dev),
        .setup          = geneve_setup,
        .validate       = geneve_validate,
        .newlink        = geneve_newlink,
        .changelink     = geneve_changelink,
        .dellink        = geneve_dellink,
        .get_size       = geneve_get_size,
        .fill_info      = geneve_fill_info,
};

struct net_device *geneve_dev_create_fb(struct net *net, const char *name,
                                        u8 name_assign_type, u16 dst_port)
{
        struct nlattr *tb[IFLA_MAX + 1];
        struct net_device *dev;
        LIST_HEAD(list_kill);
        int err;
        struct geneve_config cfg = {
                .df = GENEVE_DF_UNSET,
                .use_udp6_rx_checksums = true,
                .ttl_inherit = false,
                .collect_md = true,
                .port_min = 1,
                .port_max = USHRT_MAX,
        };

        memset(tb, 0, sizeof(tb));
        dev = rtnl_create_link(net, name, name_assign_type,
                               &geneve_link_ops, tb, NULL);
        if (IS_ERR(dev))
                return dev;

        init_tnl_info(&cfg.info, dst_port);
        err = geneve_configure(net, dev, NULL, &cfg);
        if (err) {
                free_netdev(dev);
                return ERR_PTR(err);
        }

        /* openvswitch users expect packet sizes to be unrestricted,
         * so set the largest MTU we can.
         */
        err = geneve_change_mtu(dev, IP_MAX_MTU);
        if (err)
                goto err;

        err = rtnl_configure_link(dev, NULL, 0, NULL);
        if (err < 0)
                goto err;

        return dev;
err:
        geneve_dellink(dev, &list_kill);
        unregister_netdevice_many(&list_kill);
        return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(geneve_dev_create_fb);

static int geneve_netdevice_event(struct notifier_block *unused,
                                  unsigned long event, void *ptr)
{
        struct net_device *dev = netdev_notifier_info_to_dev(ptr);

        if (event == NETDEV_UDP_TUNNEL_PUSH_INFO)
                geneve_offload_rx_ports(dev, true);
        else if (event == NETDEV_UDP_TUNNEL_DROP_INFO)
                geneve_offload_rx_ports(dev, false);

        return NOTIFY_DONE;
}

static struct notifier_block geneve_notifier_block __read_mostly = {
        .notifier_call = geneve_netdevice_event,
};

static __net_init int geneve_init_net(struct net *net)
{
        struct geneve_net *gn = net_generic(net, geneve_net_id);

        INIT_LIST_HEAD(&gn->geneve_list);
        INIT_LIST_HEAD(&gn->sock_list);
        return 0;
}

static void __net_exit geneve_exit_rtnl_net(struct net *net,
                                            struct list_head *dev_to_kill)
{
        struct geneve_net *gn = net_generic(net, geneve_net_id);
        struct geneve_dev *geneve, *next;

        list_for_each_entry_safe(geneve, next, &gn->geneve_list, next)
                geneve_dellink(geneve->dev, dev_to_kill);
}

static void __net_exit geneve_exit_net(struct net *net)
{
        const struct geneve_net *gn = net_generic(net, geneve_net_id);

        WARN_ON_ONCE(!list_empty(&gn->sock_list));
}

static struct pernet_operations geneve_net_ops = {
        .init = geneve_init_net,
        .exit_rtnl = geneve_exit_rtnl_net,
        .exit = geneve_exit_net,
        .id   = &geneve_net_id,
        .size = sizeof(struct geneve_net),
};

static int __init geneve_init_module(void)
{
        int rc;

        rc = register_pernet_subsys(&geneve_net_ops);
        if (rc)
                goto out1;

        rc = register_netdevice_notifier(&geneve_notifier_block);
        if (rc)
                goto out2;

        rc = rtnl_link_register(&geneve_link_ops);
        if (rc)
                goto out3;

        return 0;
out3:
        unregister_netdevice_notifier(&geneve_notifier_block);
out2:
        unregister_pernet_subsys(&geneve_net_ops);
out1:
        return rc;
}
late_initcall(geneve_init_module);

static void __exit geneve_cleanup_module(void)
{
        rtnl_link_unregister(&geneve_link_ops);
        unregister_netdevice_notifier(&geneve_notifier_block);
        unregister_pernet_subsys(&geneve_net_ops);
}
module_exit(geneve_cleanup_module);

MODULE_LICENSE("GPL");
MODULE_VERSION(GENEVE_NETDEV_VER);
MODULE_AUTHOR("John W. Linville <linville@tuxdriver.com>");
MODULE_DESCRIPTION("Interface driver for GENEVE encapsulated traffic");
MODULE_ALIAS_RTNL_LINK("geneve");