Commit 1b1c7a0e authored by Peter Krystad's avatar Peter Krystad Committed by David S. Miller
Browse files

mptcp: Add path manager interface 



Add enough of a path manager interface to allow sending of ADD_ADDR
when an incoming MPTCP connection is created. Capable of sending only
a single IPv4 ADD_ADDR option. The 'pm_data' element of the connection
sock will need to be expanded to handle multiple interfaces and IPv6.
Partial processing of the incoming ADD_ADDR is included so the path
manager notification of that event happens at the proper time, which
involves validating the incoming address information.

This is a skeleton interface definition for events generated by
MPTCP.

Co-developed-by: default avatarMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: default avatarMatthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Co-developed-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Co-developed-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarPeter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3df523ab

net/mptcp/Makefile

+1 −1
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

obj-$(CONFIG_MPTCP) += mptcp.o



mptcp-y := protocol.o subflow.o options.o token.o crypto.o ctrl.o
 
mptcp-y := protocol.o subflow.o options.o token.o crypto.o ctrl.o pm.o

net/mptcp/options.c

+64 −16
Original line number Diff line number Diff line
@@ -492,36 +492,35 @@ static bool mptcp_established_options_addr(struct sock *sk, 
{

	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);

	struct mptcp_sock *msk = mptcp_sk(subflow->conn);

	struct sockaddr_storage saddr;

	u8 id;

	struct mptcp_addr_info saddr;

	int len;



	id = 0;

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

	if (!mptcp_pm_should_signal(msk) ||

	    !(mptcp_pm_addr_signal(msk, remaining, &saddr)))

		return false;



	if (saddr.ss_family == AF_INET) {

		if (remaining < TCPOLEN_MPTCP_ADD_ADDR)

	len = mptcp_add_addr_len(saddr.family);

	if (remaining < len)

		return false;



	*size = len;

	opts->addr_id = saddr.id;

	if (saddr.family == AF_INET) {

		opts->suboptions |= OPTION_MPTCP_ADD_ADDR;

		opts->addr_id = id;

		opts->addr = ((struct sockaddr_in *)&saddr)->sin_addr;

		opts->addr = saddr.addr;

		opts->ahmac = add_addr_generate_hmac(msk->local_key,

						     msk->remote_key,

						     opts->addr_id,

						     &opts->addr);

		*size = TCPOLEN_MPTCP_ADD_ADDR;

	}

#if IS_ENABLED(CONFIG_MPTCP_IPV6)

	else if (saddr.ss_family == AF_INET6) {

		if (remaining < TCPOLEN_MPTCP_ADD_ADDR6)

			return false;

	else if (saddr.family == AF_INET6) {

		opts->suboptions |= OPTION_MPTCP_ADD_ADDR6;

		opts->addr_id = id;

		opts->addr6 = saddr.addr6;

		opts->ahmac = add_addr6_generate_hmac(msk->local_key,

						      msk->remote_key,

						      opts->addr_id,

						      &opts->addr6);

		opts->addr6 = ((struct sockaddr_in6 *)&saddr)->sin6_addr;

		*size = TCPOLEN_MPTCP_ADD_ADDR6;

	}

#endif

	pr_debug("addr_id=%d, ahmac=%llu", opts->addr_id, opts->ahmac);
@@ -607,10 +606,37 @@ static bool check_fully_established(struct mptcp_subflow_context *subflow, 
	return true;

}



static bool add_addr_hmac_valid(struct mptcp_sock *msk,

				struct mptcp_options_received *mp_opt)

{

	u64 hmac = 0;



	if (mp_opt->echo)

		return true;



	if (mp_opt->family == MPTCP_ADDR_IPVERSION_4)

		hmac = add_addr_generate_hmac(msk->remote_key,

					      msk->local_key,

					      mp_opt->addr_id, &mp_opt->addr);

#if IS_ENABLED(CONFIG_MPTCP_IPV6)

	else

		hmac = add_addr6_generate_hmac(msk->remote_key,

					       msk->local_key,

					       mp_opt->addr_id, &mp_opt->addr6);

#endif



	pr_debug("msk=%p, ahmac=%llu, mp_opt->ahmac=%llu\n",

		 msk, (unsigned long long)hmac,

		 (unsigned long long)mp_opt->ahmac);



	return hmac == mp_opt->ahmac;

}



void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb,

			    struct tcp_options_received *opt_rx)

{

	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);

	struct mptcp_sock *msk = mptcp_sk(subflow->conn);

	struct mptcp_options_received *mp_opt;

	struct mptcp_ext *mpext;
@@ -618,6 +644,26 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, 
	if (!check_fully_established(subflow, skb, mp_opt))

		return;



	if (mp_opt->add_addr && add_addr_hmac_valid(msk, mp_opt)) {

		struct mptcp_addr_info addr;



		addr.port = htons(mp_opt->port);

		addr.id = mp_opt->addr_id;

		if (mp_opt->family == MPTCP_ADDR_IPVERSION_4) {

			addr.family = AF_INET;

			addr.addr = mp_opt->addr;

		}

#if IS_ENABLED(CONFIG_MPTCP_IPV6)

		else if (mp_opt->family == MPTCP_ADDR_IPVERSION_6) {

			addr.family = AF_INET6;

			addr.addr6 = mp_opt->addr6;

		}

#endif

		if (!mp_opt->echo)

			mptcp_pm_add_addr_received(msk, &addr);

		mp_opt->add_addr = 0;

	}



	if (!mp_opt->dss)

		return;
@@ -654,6 +700,8 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, 
	}



	mpext->data_fin = mp_opt->data_fin;



	mptcp_pm_fully_established(msk);

}



void mptcp_write_options(__be32 *ptr, struct mptcp_out_options *opts)

net/mptcp/pm.c

0 → 100644
+113 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Multipath TCP

 *

 * Copyright (c) 2019, Intel Corporation.

 */

#include <linux/kernel.h>

#include <net/tcp.h>

#include <net/mptcp.h>

#include "protocol.h"



static struct workqueue_struct *pm_wq;



/* path manager command handlers */



int mptcp_pm_announce_addr(struct mptcp_sock *msk,

			   const struct mptcp_addr_info *addr)

{

	return -ENOTSUPP;

}



int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id)

{

	return -ENOTSUPP;

}



int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 remote_id)

{

	return -ENOTSUPP;

}



/* path manager event handlers */



void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side)

{

	struct mptcp_pm_data *pm = &msk->pm;



	pr_debug("msk=%p, token=%u side=%d", msk, msk->token, server_side);



	WRITE_ONCE(pm->server_side, server_side);

}



bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)

{

	pr_debug("msk=%p", msk);

	return false;

}



void mptcp_pm_fully_established(struct mptcp_sock *msk)

{

	pr_debug("msk=%p", msk);

}



void mptcp_pm_connection_closed(struct mptcp_sock *msk)

{

	pr_debug("msk=%p", msk);

}



void mptcp_pm_subflow_established(struct mptcp_sock *msk,

				  struct mptcp_subflow_context *subflow)

{

	pr_debug("msk=%p", msk);

}



void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id)

{

	pr_debug("msk=%p", msk);

}



void mptcp_pm_add_addr_received(struct mptcp_sock *msk,

				const struct mptcp_addr_info *addr)

{

	pr_debug("msk=%p, remote_id=%d", msk, addr->id);

}



/* path manager helpers */



bool mptcp_pm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,

			  struct mptcp_addr_info *saddr)

{

	return false;

}



int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)

{

	return 0;

}



static void pm_worker(struct work_struct *work)

{

}



void mptcp_pm_data_init(struct mptcp_sock *msk)

{

	msk->pm.add_addr_signaled = 0;

	msk->pm.add_addr_accepted = 0;

	msk->pm.local_addr_used = 0;

	msk->pm.subflows = 0;

	WRITE_ONCE(msk->pm.work_pending, false);

	WRITE_ONCE(msk->pm.addr_signal, false);

	WRITE_ONCE(msk->pm.accept_addr, false);

	WRITE_ONCE(msk->pm.accept_subflow, false);

	msk->pm.status = 0;



	spin_lock_init(&msk->pm.lock);

	INIT_WORK(&msk->pm.work, pm_worker);

}



void mptcp_pm_init(void)

{

	pm_wq = alloc_workqueue("pm_wq", WQ_UNBOUND | WQ_MEM_RECLAIM, 8);

	if (!pm_wq)

		panic("Failed to allocate workqueue");

}

net/mptcp/protocol.c

+5 −0
Original line number Diff line number Diff line
@@ -703,6 +703,8 @@ static int __mptcp_init_sock(struct sock *sk) 
	msk->first = NULL;

	inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss;



	mptcp_pm_data_init(msk);



	return 0;

}
@@ -1055,6 +1057,8 @@ void mptcp_finish_connect(struct sock *ssk) 
	WRITE_ONCE(msk->write_seq, subflow->idsn + 1);

	WRITE_ONCE(msk->ack_seq, ack_seq);

	WRITE_ONCE(msk->can_ack, 1);



	mptcp_pm_new_connection(msk, 0);

}



static void mptcp_sock_graft(struct sock *sk, struct socket *parent)
@@ -1377,6 +1381,7 @@ void mptcp_proto_init(void) 
	mptcp_prot.h.hashinfo = tcp_prot.h.hashinfo;



	mptcp_subflow_init();

	mptcp_pm_init();



	if (proto_register(&mptcp_prot, 1) != 0)

		panic("Failed to register MPTCP proto.\n");

net/mptcp/protocol.h

+79 −0
Original line number Diff line number Diff line
@@ -84,6 +84,50 @@ static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field) 
		     ((nib & 0xF) << 8) | field);

}



#define MPTCP_PM_MAX_ADDR	4



struct mptcp_addr_info {

	sa_family_t		family;

	__be16			port;

	u8			id;

	union {

		struct in_addr addr;

#if IS_ENABLED(CONFIG_MPTCP_IPV6)

		struct in6_addr addr6;

#endif

	};

};



enum mptcp_pm_status {

	MPTCP_PM_ADD_ADDR_RECEIVED,

	MPTCP_PM_ESTABLISHED,

	MPTCP_PM_SUBFLOW_ESTABLISHED,

};



struct mptcp_pm_data {

	struct mptcp_addr_info local;

	struct mptcp_addr_info remote;



	spinlock_t	lock;		/*protects the whole PM data */



	bool		addr_signal;

	bool		server_side;

	bool		work_pending;

	bool		accept_addr;

	bool		accept_subflow;

	u8		add_addr_signaled;

	u8		add_addr_accepted;

	u8		local_addr_used;

	u8		subflows;

	u8		add_addr_signal_max;

	u8		add_addr_accept_max;

	u8		local_addr_max;

	u8		subflows_max;

	u8		status;



	struct		work_struct work;

};



/* MPTCP connection sock */

struct mptcp_sock {

	/* inet_connection_sock must be the first member */
@@ -100,6 +144,7 @@ struct mptcp_sock { 
	struct skb_ext	*cached_ext;	/* for the next sendmsg */

	struct socket	*subflow; /* outgoing connect/listener/!mp_capable */

	struct sock	*first;

	struct mptcp_pm_data	pm;

};



#define mptcp_for_each_subflow(__msk, __subflow)			\
@@ -116,6 +161,7 @@ struct mptcp_subflow_request_sock { 
		mp_join : 1,

		backup : 1,

		remote_key_valid : 1;

	u8	local_id;

	u64	local_key;

	u64	remote_key;

	u64	idsn;
@@ -246,6 +292,39 @@ static inline void mptcp_crypto_key_gen_sha(u64 *key, u32 *token, u64 *idsn) 


void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);



void mptcp_pm_init(void);

void mptcp_pm_data_init(struct mptcp_sock *msk);

void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side);

void mptcp_pm_fully_established(struct mptcp_sock *msk);

bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);

void mptcp_pm_connection_closed(struct mptcp_sock *msk);

void mptcp_pm_subflow_established(struct mptcp_sock *msk,

				  struct mptcp_subflow_context *subflow);

void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id);

void mptcp_pm_add_addr_received(struct mptcp_sock *msk,

				const struct mptcp_addr_info *addr);



int mptcp_pm_announce_addr(struct mptcp_sock *msk,

			   const struct mptcp_addr_info *addr);

int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);

int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 remote_id);



static inline bool mptcp_pm_should_signal(struct mptcp_sock *msk)

{

	return READ_ONCE(msk->pm.addr_signal);

}



static inline unsigned int mptcp_add_addr_len(int family)

{

	if (family == AF_INET)

		return TCPOLEN_MPTCP_ADD_ADDR;

	return TCPOLEN_MPTCP_ADD_ADDR6;

}



bool mptcp_pm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,

			  struct mptcp_addr_info *saddr);

int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);



static inline struct mptcp_ext *mptcp_get_ext(struct sk_buff *skb)

{

	return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);

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