root/net/ethtool/tunnels.c
// SPDX-License-Identifier: GPL-2.0-only

#include <linux/ethtool_netlink.h>
#include <net/udp_tunnel.h>
#include <net/vxlan.h>

#include "bitset.h"
#include "common.h"
#include "netlink.h"

const struct nla_policy ethnl_tunnel_info_get_policy[] = {
        [ETHTOOL_A_TUNNEL_INFO_HEADER]          =
                NLA_POLICY_NESTED(ethnl_header_policy),
};

static_assert(ETHTOOL_UDP_TUNNEL_TYPE_VXLAN == ilog2(UDP_TUNNEL_TYPE_VXLAN));
static_assert(ETHTOOL_UDP_TUNNEL_TYPE_GENEVE == ilog2(UDP_TUNNEL_TYPE_GENEVE));
static_assert(ETHTOOL_UDP_TUNNEL_TYPE_VXLAN_GPE ==
              ilog2(UDP_TUNNEL_TYPE_VXLAN_GPE));

static ssize_t ethnl_udp_table_reply_size(unsigned int types, bool compact)
{
        ssize_t size;

        size = ethnl_bitset32_size(&types, NULL, __ETHTOOL_UDP_TUNNEL_TYPE_CNT,
                                   udp_tunnel_type_names, compact);
        if (size < 0)
                return size;

        return size +
                nla_total_size(0) + /* _UDP_TABLE */
                nla_total_size(sizeof(u32)); /* _UDP_TABLE_SIZE */
}

static ssize_t
ethnl_tunnel_info_reply_size(const struct ethnl_req_info *req_base,
                             struct netlink_ext_ack *extack)
{
        bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
        const struct udp_tunnel_nic_info *info;
        unsigned int i;
        ssize_t ret;
        size_t size;

        info = req_base->dev->udp_tunnel_nic_info;
        if (!info) {
                NL_SET_ERR_MSG(extack,
                               "device does not report tunnel offload info");
                return -EOPNOTSUPP;
        }

        size =  nla_total_size(0); /* _INFO_UDP_PORTS */

        for (i = 0; i < UDP_TUNNEL_NIC_MAX_TABLES; i++) {
                if (!info->tables[i].n_entries)
                        break;

                ret = ethnl_udp_table_reply_size(info->tables[i].tunnel_types,
                                                 compact);
                if (ret < 0)
                        return ret;
                size += ret;

                size += udp_tunnel_nic_dump_size(req_base->dev, i);
        }

        if (info->flags & UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN) {
                ret = ethnl_udp_table_reply_size(0, compact);
                if (ret < 0)
                        return ret;
                size += ret;

                size += nla_total_size(0) +              /* _TABLE_ENTRY */
                        nla_total_size(sizeof(__be16)) + /* _ENTRY_PORT */
                        nla_total_size(sizeof(u32));     /* _ENTRY_TYPE */
        }

        return size;
}

static int
ethnl_tunnel_info_fill_reply(const struct ethnl_req_info *req_base,
                             struct sk_buff *skb)
{
        bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
        const struct udp_tunnel_nic_info *info;
        struct nlattr *ports, *table, *entry;
        unsigned int i;

        info = req_base->dev->udp_tunnel_nic_info;
        if (!info)
                return -EOPNOTSUPP;

        ports = nla_nest_start(skb, ETHTOOL_A_TUNNEL_INFO_UDP_PORTS);
        if (!ports)
                return -EMSGSIZE;

        for (i = 0; i < UDP_TUNNEL_NIC_MAX_TABLES; i++) {
                if (!info->tables[i].n_entries)
                        break;

                table = nla_nest_start(skb, ETHTOOL_A_TUNNEL_UDP_TABLE);
                if (!table)
                        goto err_cancel_ports;

                if (nla_put_u32(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_SIZE,
                                info->tables[i].n_entries))
                        goto err_cancel_table;

                if (ethnl_put_bitset32(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_TYPES,
                                       &info->tables[i].tunnel_types, NULL,
                                       __ETHTOOL_UDP_TUNNEL_TYPE_CNT,
                                       udp_tunnel_type_names, compact))
                        goto err_cancel_table;

                if (udp_tunnel_nic_dump_write(req_base->dev, i, skb))
                        goto err_cancel_table;

                nla_nest_end(skb, table);
        }

        if (info->flags & UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN) {
                u32 zero = 0;

                table = nla_nest_start(skb, ETHTOOL_A_TUNNEL_UDP_TABLE);
                if (!table)
                        goto err_cancel_ports;

                if (nla_put_u32(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_SIZE, 1))
                        goto err_cancel_table;

                if (ethnl_put_bitset32(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_TYPES,
                                       &zero, NULL,
                                       __ETHTOOL_UDP_TUNNEL_TYPE_CNT,
                                       udp_tunnel_type_names, compact))
                        goto err_cancel_table;

                entry = nla_nest_start(skb, ETHTOOL_A_TUNNEL_UDP_TABLE_ENTRY);
                if (!entry)
                        goto err_cancel_entry;

                if (nla_put_be16(skb, ETHTOOL_A_TUNNEL_UDP_ENTRY_PORT,
                                 htons(IANA_VXLAN_UDP_PORT)) ||
                    nla_put_u32(skb, ETHTOOL_A_TUNNEL_UDP_ENTRY_TYPE,
                                ilog2(UDP_TUNNEL_TYPE_VXLAN)))
                        goto err_cancel_entry;

                nla_nest_end(skb, entry);
                nla_nest_end(skb, table);
        }

        nla_nest_end(skb, ports);

        return 0;

err_cancel_entry:
        nla_nest_cancel(skb, entry);
err_cancel_table:
        nla_nest_cancel(skb, table);
err_cancel_ports:
        nla_nest_cancel(skb, ports);
        return -EMSGSIZE;
}

int ethnl_tunnel_info_doit(struct sk_buff *skb, struct genl_info *info)
{
        struct ethnl_req_info req_info = {};
        struct nlattr **tb = info->attrs;
        struct sk_buff *rskb;
        void *reply_payload;
        int reply_len;
        int ret;

        ret = ethnl_parse_header_dev_get(&req_info,
                                         tb[ETHTOOL_A_TUNNEL_INFO_HEADER],
                                         genl_info_net(info), info->extack,
                                         true);
        if (ret < 0)
                return ret;

        rtnl_lock();
        ret = ethnl_tunnel_info_reply_size(&req_info, info->extack);
        if (ret < 0)
                goto err_unlock_rtnl;
        reply_len = ret + ethnl_reply_header_size();

        rskb = ethnl_reply_init(reply_len, req_info.dev,
                                ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY,
                                ETHTOOL_A_TUNNEL_INFO_HEADER,
                                info, &reply_payload);
        if (!rskb) {
                ret = -ENOMEM;
                goto err_unlock_rtnl;
        }

        ret = ethnl_tunnel_info_fill_reply(&req_info, rskb);
        if (ret)
                goto err_free_msg;
        rtnl_unlock();
        ethnl_parse_header_dev_put(&req_info);
        genlmsg_end(rskb, reply_payload);

        return genlmsg_reply(rskb, info);

err_free_msg:
        nlmsg_free(rskb);
err_unlock_rtnl:
        rtnl_unlock();
        ethnl_parse_header_dev_put(&req_info);
        return ret;
}

struct ethnl_tunnel_info_dump_ctx {
        struct ethnl_req_info   req_info;
        unsigned long           ifindex;
};

int ethnl_tunnel_info_start(struct netlink_callback *cb)
{
        const struct genl_dumpit_info *info = genl_dumpit_info(cb);
        struct ethnl_tunnel_info_dump_ctx *ctx = (void *)cb->ctx;
        struct nlattr **tb = info->info.attrs;
        int ret;

        BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));

        memset(ctx, 0, sizeof(*ctx));

        ret = ethnl_parse_header_dev_get(&ctx->req_info,
                                         tb[ETHTOOL_A_TUNNEL_INFO_HEADER],
                                         sock_net(cb->skb->sk), cb->extack,
                                         false);
        if (ctx->req_info.dev) {
                ethnl_parse_header_dev_put(&ctx->req_info);
                ctx->req_info.dev = NULL;
        }

        return ret;
}

int ethnl_tunnel_info_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
{
        struct ethnl_tunnel_info_dump_ctx *ctx = (void *)cb->ctx;
        struct net *net = sock_net(skb->sk);
        struct net_device *dev;
        int ret = 0;
        void *ehdr;

        rtnl_lock();
        for_each_netdev_dump(net, dev, ctx->ifindex) {
                ehdr = ethnl_dump_put(skb, cb,
                                      ETHTOOL_MSG_TUNNEL_INFO_GET_REPLY);
                if (!ehdr) {
                        ret = -EMSGSIZE;
                        break;
                }

                ret = ethnl_fill_reply_header(skb, dev,
                                              ETHTOOL_A_TUNNEL_INFO_HEADER);
                if (ret < 0) {
                        genlmsg_cancel(skb, ehdr);
                        break;
                }

                ctx->req_info.dev = dev;
                ret = ethnl_tunnel_info_fill_reply(&ctx->req_info, skb);
                ctx->req_info.dev = NULL;
                if (ret < 0) {
                        genlmsg_cancel(skb, ehdr);
                        if (ret == -EOPNOTSUPP)
                                continue;
                        break;
                }
                genlmsg_end(skb, ehdr);
        }
        rtnl_unlock();

        if (ret == -EMSGSIZE && skb->len)
                return skb->len;
        return ret;
}