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;
}