Commit eda7acdd authored by Peter Krystad's avatar Peter Krystad Committed by David S. Miller
Browse files

mptcp: Handle MPTCP TCP options 



Add hooks to parse and format the MP_CAPABLE option.

This option is handled according to MPTCP version 0 (RFC6824).
MPTCP version 1 MP_CAPABLE (RFC6824bis/RFC8684) will be added later in
coordination with related code changes.

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 avatarDavide Caratti <dcaratti@redhat.com>
Signed-off-by: default avatarDavide Caratti <dcaratti@redhat.com>
Signed-off-by: default avatarPeter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: default avatarChristoph Paasch <cpaasch@apple.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f870fa0b

include/linux/tcp.h

+18 −0
Original line number Diff line number Diff line
@@ -78,6 +78,16 @@ struct tcp_sack_block { 
#define TCP_SACK_SEEN     (1 << 0)   /*1 = peer is SACK capable, */

#define TCP_DSACK_SEEN    (1 << 2)   /*1 = DSACK was received from peer*/



#if IS_ENABLED(CONFIG_MPTCP)

struct mptcp_options_received {

	u64	sndr_key;

	u64	rcvr_key;

	u8	mp_capable : 1,

		mp_join : 1,

		dss : 1;

};

#endif



struct tcp_options_received {

/*	PAWS/RTTM data	*/

	int	ts_recent_stamp;/* Time we stored ts_recent (for aging) */
@@ -95,6 +105,9 @@ struct tcp_options_received { 
	u8	num_sacks;	/* Number of SACK blocks		*/

	u16	user_mss;	/* mss requested by user in ioctl	*/

	u16	mss_clamp;	/* Maximal mss, negotiated at connection setup */

#if IS_ENABLED(CONFIG_MPTCP)

	struct mptcp_options_received	mptcp;

#endif

};



static inline void tcp_clear_options(struct tcp_options_received *rx_opt)
@@ -104,6 +117,11 @@ static inline void tcp_clear_options(struct tcp_options_received *rx_opt) 
#if IS_ENABLED(CONFIG_SMC)

	rx_opt->smc_ok = 0;

#endif

#if IS_ENABLED(CONFIG_MPTCP)

	rx_opt->mptcp.mp_capable = 0;

	rx_opt->mptcp.mp_join = 0;

	rx_opt->mptcp.dss = 0;

#endif

}



/* This is the max number of SACKS that we'll generate and process. It's safe

include/net/mptcp.h

+18 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#define __NET_MPTCP_H



#include <linux/skbuff.h>

#include <linux/tcp.h>

#include <linux/types.h>



/* MPTCP sk_buff extension data */
@@ -26,10 +27,22 @@ struct mptcp_ext { 
	/* one byte hole */

};



struct mptcp_out_options {

#if IS_ENABLED(CONFIG_MPTCP)

	u16 suboptions;

	u64 sndr_key;

	u64 rcvr_key;

#endif

};



#ifdef CONFIG_MPTCP



void mptcp_init(void);



void mptcp_parse_option(const unsigned char *ptr, int opsize,

			struct tcp_options_received *opt_rx);

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



/* move the skb extension owership, with the assumption that 'to' is

 * newly allocated

 */
@@ -76,6 +89,11 @@ static inline void mptcp_init(void) 
{

}



static inline void mptcp_parse_option(const unsigned char *ptr, int opsize,

				      struct tcp_options_received *opt_rx)

{

}



static inline void mptcp_skb_ext_move(struct sk_buff *to,

				      const struct sk_buff *from)

{

net/ipv4/tcp_input.c

+5 −0
Original line number Diff line number Diff line
@@ -79,6 +79,7 @@ 
#include <trace/events/tcp.h>

#include <linux/jump_label_ratelimit.h>

#include <net/busy_poll.h>

#include <net/mptcp.h>



int sysctl_tcp_max_orphans __read_mostly = NR_FILE;
@@ -3924,6 +3925,10 @@ void tcp_parse_options(const struct net *net, 
				 */

				break;

#endif

			case TCPOPT_MPTCP:

				mptcp_parse_option(ptr, opsize, opt_rx);

				break;



			case TCPOPT_FASTOPEN:

				tcp_parse_fastopen_option(

					opsize - TCPOLEN_FASTOPEN_BASE,

net/ipv4/tcp_output.c

+13 −0
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ 
#define pr_fmt(fmt) "TCP: " fmt



#include <net/tcp.h>

#include <net/mptcp.h>



#include <linux/compiler.h>

#include <linux/gfp.h>
@@ -414,6 +415,7 @@ static inline bool tcp_urg_mode(const struct tcp_sock *tp) 
#define OPTION_WSCALE		(1 << 3)

#define OPTION_FAST_OPEN_COOKIE	(1 << 8)

#define OPTION_SMC		(1 << 9)

#define OPTION_MPTCP		(1 << 10)



static void smc_options_write(__be32 *ptr, u16 *options)

{
@@ -439,8 +441,17 @@ struct tcp_out_options { 
	__u8 *hash_location;	/* temporary pointer, overloaded */

	__u32 tsval, tsecr;	/* need to include OPTION_TS */

	struct tcp_fastopen_cookie *fastopen_cookie;	/* Fast open cookie */

	struct mptcp_out_options mptcp;

};



static void mptcp_options_write(__be32 *ptr, struct tcp_out_options *opts)

{

#if IS_ENABLED(CONFIG_MPTCP)

	if (unlikely(OPTION_MPTCP & opts->options))

		mptcp_write_options(ptr, &opts->mptcp);

#endif

}



/* Write previously computed TCP options to the packet.

 *

 * Beware: Something in the Internet is very sensitive to the ordering of
@@ -549,6 +560,8 @@ static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp, 
	}



	smc_options_write(ptr, &options);



	mptcp_options_write(ptr, opts);

}



static void smc_set_option(const struct tcp_sock *tp,

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
 
mptcp-y := protocol.o options.o

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