Commit 702c2f64 authored by Florian Westphal's avatar Florian Westphal Committed by David S. Miller
Browse files

mptcp: netlink: allow userspace-driven subflow establishment 



This allows userspace to tell kernel to add a new subflow to an existing
mptcp connection.

Userspace provides the token to identify the mptcp-level connection
that needs a change in active subflows and the local and remote
addresses of the new or the to-be-removed subflow.

MPTCP_PM_CMD_SUBFLOW_CREATE requires the following parameters:
{ token, { loc_id, family, loc_addr4 | loc_addr6 }, { family, rem_addr4 |
rem_addr6, rem_port }

MPTCP_PM_CMD_SUBFLOW_DESTROY requires the following parameters:
{ token, { family, loc_addr4 | loc_addr6, loc_port }, { family, rem_addr4 |
rem_addr6, rem_port }

Acked-by: default avatarPaolo Abeni <pabeni@redhat.com>
Co-developed-by: default avatarKishen Maloor <kishen.maloor@intel.com>
Signed-off-by: default avatarKishen Maloor <kishen.maloor@intel.com>
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ecd2a77d

include/uapi/linux/mptcp.h

+3 −0
Original line number Diff line number Diff line
@@ -57,6 +57,7 @@ enum { 
	MPTCP_PM_ATTR_SUBFLOWS,				/* u32 */

	MPTCP_PM_ATTR_TOKEN,				/* u32 */

	MPTCP_PM_ATTR_LOC_ID,				/* u8 */

	MPTCP_PM_ATTR_ADDR_REMOTE,			/* nested address */



	__MPTCP_PM_ATTR_MAX

};
@@ -97,6 +98,8 @@ enum { 
	MPTCP_PM_CMD_SET_FLAGS,

	MPTCP_PM_CMD_ANNOUNCE,

	MPTCP_PM_CMD_REMOVE,

	MPTCP_PM_CMD_SUBFLOW_CREATE,

	MPTCP_PM_CMD_SUBFLOW_DESTROY,



	__MPTCP_PM_CMD_AFTER_LAST

};

net/mptcp/pm_netlink.c

+22 −0
Original line number Diff line number Diff line
@@ -1096,6 +1096,8 @@ static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = { 
	[MPTCP_PM_ATTR_SUBFLOWS]	= { .type	= NLA_U32,	},

	[MPTCP_PM_ATTR_TOKEN]		= { .type	= NLA_U32,	},

	[MPTCP_PM_ATTR_LOC_ID]		= { .type	= NLA_U8,	},

	[MPTCP_PM_ATTR_ADDR_REMOTE]	=

					NLA_POLICY_NESTED(mptcp_pm_addr_policy),

};



void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
@@ -1205,6 +1207,16 @@ static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[], 
	return err;

}



int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,

			struct mptcp_addr_info *addr)

{

	struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];



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



	return mptcp_pm_parse_pm_addr_attr(tb, attr, info, addr, true);

}



int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,

			 bool require_family,

			 struct mptcp_pm_addr_entry *entry)
@@ -2210,6 +2222,16 @@ static const struct genl_small_ops mptcp_pm_ops[] = { 
		.doit   = mptcp_nl_cmd_remove,

		.flags  = GENL_ADMIN_PERM,

	},

	{

		.cmd    = MPTCP_PM_CMD_SUBFLOW_CREATE,

		.doit   = mptcp_nl_cmd_sf_create,

		.flags  = GENL_ADMIN_PERM,

	},

	{

		.cmd    = MPTCP_PM_CMD_SUBFLOW_DESTROY,

		.doit   = mptcp_nl_cmd_sf_destroy,

		.flags  = GENL_ADMIN_PERM,

	},

};



static struct genl_family mptcp_genl_family __ro_after_init = {

net/mptcp/pm_userspace.c

+185 −0
Original line number Diff line number Diff line
@@ -242,3 +242,188 @@ int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info) 
	sock_put((struct sock *)msk);

	return err;

}



int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)

{

	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];

	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];

	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];

	struct mptcp_addr_info addr_r;

	struct mptcp_addr_info addr_l;

	struct mptcp_sock *msk;

	int err = -EINVAL;

	struct sock *sk;

	u32 token_val;



	if (!laddr || !raddr || !token) {

		GENL_SET_ERR_MSG(info, "missing required inputs");

		return err;

	}



	token_val = nla_get_u32(token);



	msk = mptcp_token_get_sock(genl_info_net(info), token_val);

	if (!msk) {

		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");

		return err;

	}



	if (!mptcp_pm_is_userspace(msk)) {

		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");

		goto create_err;

	}



	err = mptcp_pm_parse_addr(laddr, info, &addr_l);

	if (err < 0) {

		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");

		goto create_err;

	}



	if (addr_l.id == 0) {

		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "missing local addr id");

		goto create_err;

	}



	err = mptcp_pm_parse_addr(raddr, info, &addr_r);

	if (err < 0) {

		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");

		goto create_err;

	}



	sk = &msk->sk.icsk_inet.sk;

	lock_sock(sk);



	err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);



	release_sock(sk);



 create_err:

	sock_put((struct sock *)msk);

	return err;

}



static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,

				      const struct mptcp_addr_info *local,

				      const struct mptcp_addr_info *remote)

{

	struct sock *sk = &msk->sk.icsk_inet.sk;

	struct mptcp_subflow_context *subflow;

	struct sock *found = NULL;



	if (local->family != remote->family)

		return NULL;



	lock_sock(sk);



	mptcp_for_each_subflow(msk, subflow) {

		const struct inet_sock *issk;

		struct sock *ssk;



		ssk = mptcp_subflow_tcp_sock(subflow);



		if (local->family != ssk->sk_family)

			continue;



		issk = inet_sk(ssk);



		switch (ssk->sk_family) {

		case AF_INET:

			if (issk->inet_saddr != local->addr.s_addr ||

			    issk->inet_daddr != remote->addr.s_addr)

				continue;

			break;

#if IS_ENABLED(CONFIG_MPTCP_IPV6)

		case AF_INET6: {

			const struct ipv6_pinfo *pinfo = inet6_sk(ssk);



			if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||

			    !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))

				continue;

			break;

		}

#endif

		default:

			continue;

		}



		if (issk->inet_sport == local->port &&

		    issk->inet_dport == remote->port) {

			found = ssk;

			goto found;

		}

	}



found:

	release_sock(sk);



	return found;

}



int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)

{

	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];

	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];

	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];

	struct mptcp_addr_info addr_l;

	struct mptcp_addr_info addr_r;

	struct mptcp_sock *msk;

	struct sock *sk, *ssk;

	int err = -EINVAL;

	u32 token_val;



	if (!laddr || !raddr || !token) {

		GENL_SET_ERR_MSG(info, "missing required inputs");

		return err;

	}



	token_val = nla_get_u32(token);



	msk = mptcp_token_get_sock(genl_info_net(info), token_val);

	if (!msk) {

		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");

		return err;

	}



	if (!mptcp_pm_is_userspace(msk)) {

		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");

		goto destroy_err;

	}



	err = mptcp_pm_parse_addr(laddr, info, &addr_l);

	if (err < 0) {

		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");

		goto destroy_err;

	}



	err = mptcp_pm_parse_addr(raddr, info, &addr_r);

	if (err < 0) {

		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");

		goto destroy_err;

	}



	if (addr_l.family != addr_r.family) {

		GENL_SET_ERR_MSG(info, "address families do not match");

		goto destroy_err;

	}



	if (!addr_l.port || !addr_r.port) {

		GENL_SET_ERR_MSG(info, "missing local or remote port");

		goto destroy_err;

	}



	sk = &msk->sk.icsk_inet.sk;

	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);

	if (ssk) {

		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);



		mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);

		mptcp_close_ssk(sk, ssk, subflow);

		err = 0;

	} else {

		err = -ESRCH;

	}



 destroy_err:

	sock_put((struct sock *)msk);

	return err;

}

net/mptcp/protocol.h

+4 −0
Original line number Diff line number Diff line
@@ -756,6 +756,8 @@ u16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum); 
void __init mptcp_pm_init(void);

void mptcp_pm_data_init(struct mptcp_sock *msk);

void mptcp_pm_data_reset(struct mptcp_sock *msk);

int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,

			struct mptcp_addr_info *addr);

int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,

			 bool require_family,

			 struct mptcp_pm_addr_entry *entry);
@@ -809,6 +811,8 @@ int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk, 
void mptcp_free_local_addr_list(struct mptcp_sock *msk);

int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info);

int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info);

int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info);

int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info);



void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,

		 const struct sock *ssk, gfp_t gfp);