xref: /xnu-11417.140.69/bsd/netinet/mptcp_var.h (revision 43a90889846e00bfb5cf1d255cdc0a701a1e05a4)
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28 
29 #ifndef _NETINET_MPTCP_VAR_H_
30 #define _NETINET_MPTCP_VAR_H_
31 
32 #ifdef PRIVATE
33 #include <netinet/in.h>
34 #include <netinet/tcp.h>
35 #endif
36 
37 #ifdef BSD_KERNEL_PRIVATE
38 #include <sys/queue.h>
39 #include <sys/protosw.h>
40 #include <kern/locks.h>
41 #include <mach/boolean.h>
42 #include <netinet/mp_pcb.h>
43 #include <netinet/tcp_var.h>
44 #include <os/log.h>
45 #include <libkern/crypto/sha1.h>
46 #include <libkern/crypto/sha2.h>
47 
48 struct mpt_itf_info {
49 	uint32_t ifindex;
50 	uint32_t has_v4_conn:1,
51 	    has_v6_conn:1,
52 	    has_nat64_conn:1,
53 	    no_mptcp_support:1;
54 };
55 
56 /*
57  * MPTCP Session
58  *
59  * This is an extension to the multipath PCB specific for MPTCP, protected by
60  * the per-PCB mpp_lock (also the socket's lock);
61  */
62 struct mptses {
63 	struct mppcb    *mpte_mppcb;            /* back ptr to multipath PCB */
64 	struct mptcb    *mpte_mptcb;            /* ptr to MPTCP PCB */
65 	TAILQ_HEAD(, mptopt) mpte_sopts;        /* list of socket options */
66 	TAILQ_HEAD(, mptsub) mpte_subflows;     /* list of subflows */
67 #define MPTCP_MAX_NUM_SUBFLOWS 256
68 	uint16_t        mpte_numflows;          /* # of subflows in list */
69 	uint16_t        mpte_nummpcapflows;     /* # of MP_CAP subflows */
70 	sae_associd_t   mpte_associd;           /* MPTCP association ID */
71 	sae_connid_t    mpte_connid_last;       /* last used connection ID */
72 
73 	uint64_t        mpte_time_target;
74 	thread_call_t   mpte_time_thread;
75 	thread_call_t   mpte_stop_urgency;
76 
77 	uint32_t        mpte_last_cellicon_set;
78 	uint32_t        mpte_cellicon_increments;
79 
80 	union {
81 		/* Source address of initial subflow */
82 		struct sockaddr _mpte_src;
83 		struct sockaddr_in _mpte_src_v4;
84 		struct sockaddr_in6 _mpte_src_v6;
85 	} mpte_u_src;
86 #define mpte_src mpte_u_src._mpte_src
87 #define __mpte_src_v4 mpte_u_src._mpte_src_v4
88 #define __mpte_src_v6 mpte_u_src._mpte_src_v6
89 	union {
90 		/* Destination address of initial subflow */
91 		struct sockaddr _mpte_dst;
92 		struct sockaddr_in _mpte_dst_v4;
93 		struct sockaddr_in6 _mpte_dst_v6;
94 	} mpte_u_dst;
95 #define mpte_dst mpte_u_dst._mpte_dst
96 #define __mpte_dst_v4 mpte_u_dst._mpte_dst_v4
97 #define __mpte_dst_v6 mpte_u_dst._mpte_dst_v6
98 
99 	struct sockaddr_in      mpte_sub_dst_v4;
100 	struct sockaddr_in6     mpte_sub_dst_v6;
101 	uint8_t         sub_dst_addr_id_v4;
102 	uint8_t         sub_dst_addr_id_v6;
103 
104 	uint16_t        mpte_alternate_port;    /* Alternate port for subflow establishment (network-byte-order) */
105 
106 	int mpte_epid;
107 	uuid_t mpte_euuid;
108 
109 	struct mptsub   *mpte_active_sub;       /* ptr to last active subf */
110 	uint16_t mpte_flags;                    /* per mptcp session flags */
111 #define MPTE_SND_REM_ADDR       0x01            /* Send Remove_addr option */
112 #define MPTE_SVCTYPE_CHECKED    0x02            /* Did entitlement-check for service-type */
113 #define MPTE_FIRSTPARTY         0x04            /* First-party app used multipath_extended entitlement */
114 #define MPTE_ACCESS_GRANTED     0x08            /* Access to cellular has been granted for this connection */
115 #define MPTE_FORCE_ENABLE       0x10            /* For MPTCP regardless of heuristics to detect middleboxes */
116 #define MPTE_IN_WORKLOOP        0x20            /* Are we currently inside the workloop ? */
117 #define MPTE_WORKLOOP_RELAUNCH  0x40            /* Another event got queued, we should restart the workloop */
118 #define MPTE_UNICAST_IP         0x80            /* New subflows are only being established towards the unicast IP in the ADD_ADDR */
119 #define MPTE_CELL_PROHIBITED    0x100           /* Cell access has been prohibited based on signal quality */
120 #define MPTE_FORCE_V0           0x200           /* Force MPTCP to use version 0 regradless of tcp cache */
121 #define MPTE_FORCE_V1           0x400           /* Force MPTCP to use version 1 regradless of tcp cache */
122 #define MPTE_ITFINFO_INIT       0x800           /* Set when the itfinfo has been initialized */
123 	uint8_t mpte_svctype;                   /* MPTCP Service type */
124 	uint8_t mpte_lost_aid;                  /* storing lost address id */
125 	uint8_t mpte_addrid_last;               /* storing address id parm */
126 
127 #define MPTE_ITFINFO_SIZE       4
128 	uint32_t        mpte_itfinfo_size;
129 	struct mpt_itf_info     _mpte_itfinfo[MPTE_ITFINFO_SIZE];
130 	struct mpt_itf_info     *mpte_itfinfo __counted_by(mpte_itfinfo_size);
131 
132 	struct mbuf             *mpte_reinjectq;
133 
134 	/* The below is used for stats */
135 	uint32_t        mpte_subflow_switches;  /* Number of subflow-switches in sending */
136 	uint32_t        mpte_used_cell:1,
137 	    mpte_used_wifi:1,
138 	    mpte_initial_cell:1,
139 	    mpte_triggered_cell,
140 	    mpte_handshake_success:1,
141 	    mpte_last_added_addr_is_v4:1;
142 
143 	struct mptcp_itf_stats  mpte_itfstats[MPTCP_ITFSTATS_SIZE];
144 	uint64_t                mpte_init_txbytes __attribute__((aligned(8)));
145 	uint64_t                mpte_init_rxbytes __attribute__((aligned(8)));
146 };
147 
148 static inline struct socket *
mptetoso(struct mptses * mpte)149 mptetoso(struct mptses *mpte)
150 {
151 	return mpte->mpte_mppcb->mpp_socket;
152 }
153 
154 static inline struct mptses *
mptompte(struct mppcb * mp)155 mptompte(struct mppcb *mp)
156 {
157 	return (struct mptses *)mp->mpp_pcbe;
158 }
159 
160 static inline struct mptses *
mpsotompte(struct socket * so)161 mpsotompte(struct socket *so)
162 {
163 	return mptompte(mpsotomppcb(so));
164 }
165 
166 static inline boolean_t
mpp_try_lock(struct mppcb * mp)167 mpp_try_lock(struct mppcb *mp)
168 {
169 	if (!lck_mtx_try_lock(&mp->mpp_lock)) {
170 		return false;
171 	}
172 
173 	VERIFY(!(mp->mpp_flags & MPP_INSIDE_OUTPUT));
174 	VERIFY(!(mp->mpp_flags & MPP_INSIDE_INPUT));
175 	VERIFY(!(mp->mpp_flags & MPP_INSIDE_SETGETOPT));
176 
177 	return true;
178 }
179 
180 static inline void
mpp_lock(struct mppcb * mp)181 mpp_lock(struct mppcb *mp)
182 {
183 	lck_mtx_lock(&mp->mpp_lock);
184 	VERIFY(!(mp->mpp_flags & MPP_INSIDE_OUTPUT));
185 	VERIFY(!(mp->mpp_flags & MPP_INSIDE_INPUT));
186 	VERIFY(!(mp->mpp_flags & MPP_INSIDE_SETGETOPT));
187 }
188 
189 static inline void
mpp_unlock(struct mppcb * mp)190 mpp_unlock(struct mppcb *mp)
191 {
192 	VERIFY(!(mp->mpp_flags & MPP_INSIDE_OUTPUT));
193 	VERIFY(!(mp->mpp_flags & MPP_INSIDE_INPUT));
194 	VERIFY(!(mp->mpp_flags & MPP_INSIDE_SETGETOPT));
195 	lck_mtx_unlock(&mp->mpp_lock);
196 }
197 
198 static inline lck_mtx_t *
mpp_getlock(struct mppcb * mp,int flags)199 mpp_getlock(struct mppcb *mp, int flags)
200 {
201 	if (flags & PR_F_WILLUNLOCK) {
202 		VERIFY(!(mp->mpp_flags & MPP_INSIDE_OUTPUT));
203 		VERIFY(!(mp->mpp_flags & MPP_INSIDE_INPUT));
204 		VERIFY(!(mp->mpp_flags & MPP_INSIDE_SETGETOPT));
205 	}
206 
207 	return &mp->mpp_lock;
208 }
209 
210 static inline int
mptcp_subflow_cwnd_space(struct socket * so)211 mptcp_subflow_cwnd_space(struct socket *so)
212 {
213 	struct tcpcb *tp = sototcpcb(so);
214 	int cwnd = (int)(MIN(tp->snd_wnd, tp->snd_cwnd) - (so->so_snd.sb_cc));
215 
216 	return MIN(cwnd, sbspace(&so->so_snd));
217 }
218 
219 static inline bool
mptcp_subflows_need_backup_flag(struct mptses * mpte)220 mptcp_subflows_need_backup_flag(struct mptses *mpte)
221 {
222 	return mpte->mpte_svctype < MPTCP_SVCTYPE_AGGREGATE ||
223 	       mpte->mpte_svctype == MPTCP_SVCTYPE_PURE_HANDOVER;
224 }
225 
226 /*
227  * MPTCP socket options
228  */
229 struct mptopt {
230 	TAILQ_ENTRY(mptopt)     mpo_entry;      /* glue to other options */
231 	uint32_t                mpo_flags;      /* see flags below */
232 	int                     mpo_level;      /* sopt_level */
233 	int                     mpo_name;       /* sopt_name */
234 	int                     mpo_intval;     /* sopt_val */
235 };
236 
237 #define MPOF_ATTACHED           0x1     /* attached to MP socket */
238 #define MPOF_SUBFLOW_OK         0x2     /* can be issued on subflow socket */
239 #define MPOF_INTERIM            0x4     /* has not been issued on any subflow */
240 
241 /*
242  * MPTCP subflow
243  */
244 struct mptsub {
245 	TAILQ_ENTRY(mptsub)   mpts_entry;     /* glue to peer subflows */
246 	uint32_t              mpts_refcnt;    /* reference count */
247 	uint32_t              mpts_flags;     /* see flags below */
248 	uint32_t              mpts_evctl;     /* subflow control events */
249 	sae_connid_t          mpts_connid;    /* subflow connection ID */
250 	int                   mpts_oldintval; /* sopt_val before sosetopt  */
251 	struct mptses         *mpts_mpte;     /* back ptr to MPTCP session */
252 	struct socket         *mpts_socket;   /* subflow socket */
253 	struct sockaddr       *mpts_src;      /* source address */
254 
255 	union {
256 		/* destination address */
257 		struct sockaddr         _mpts_dst;
258 		struct sockaddr_in      _mpts_dst_v4;
259 		struct sockaddr_in6     _mpts_dst_v6;
260 	} mpts_u_dst;
261 #define mpts_dst mpts_u_dst._mpts_dst
262 #define __mpts_dst_v4 mpts_u_dst._mpts_dst_v4
263 #define __mpts_dst_v6 mpts_u_dst._mpts_dst_v6
264 	u_int32_t               mpts_rel_seq;   /* running count of subflow # */
265 	u_int32_t               mpts_iss;       /* Initial sequence number, taking TFO into account */
266 	u_int32_t               mpts_ifscope;   /* scoped to the interface */
267 	uint32_t                mpts_probesoon; /* send probe after probeto */
268 	uint32_t                mpts_probecnt;  /* number of probes sent */
269 	uint32_t                mpts_maxseg;    /* cached value of t_maxseg */
270 };
271 
272 /*
273  * Valid values for mpts_flags.  In particular:
274  *
275  *    - MP_CAPABLE means that the connection is successfully established as
276  *	MPTCP and data transfer may occur, but is not yet ready for multipath-
277  *	related semantics until MP_READY.  I.e. if this is on the first subflow,
278  *	it causes the MPTCP socket to transition to a connected state, except
279  *	that additional subflows will not be established; they will be marked
280  *	with PENDING and will be processed when the first subflow is marked
281  *	with MP_READY.
282  *
283  *    - MP_READY implies that an MP_CAPABLE connection has been confirmed as
284  *	an MPTCP connection.  See notes above.
285  *
286  *    - MP_DEGRADED implies that the connection has lost its MPTCP capabilities
287  *	but data transfer on the MPTCP socket is unaffected.  Any existing
288  *	PENDING subflows will be disconnected, and further attempts to connect
289  *	additional subflows will be rejected.
290  *
291  * Note that these are per-subflow flags.  The setting and clearing of MP_READY
292  * reflects the state of the MPTCP connection with regards to its multipath
293  * semantics, via the MPTCPF_JOIN_READY flag.  Until that flag is set (meaning
294  * until at least a subflow is marked with MP_READY), further connectx(2)
295  * attempts to join will be queued.  When the flag is cleared (after it has
296  * been set), further connectx(2) will fail (and existing queued ones will be
297  * aborted) and the MPTCP connection loses all of its multipath semantics.
298  *
299  * Keep in sync with bsd/dev/dtrace/scripts/mptcp.d.
300  */
301 #define MPTSF_CONNECTING        0x00000002      /* connection was attempted */
302 #define MPTSF_CONNECT_PENDING   0x00000004      /* will connect when MPTCP is ready */
303 #define MPTSF_CONNECTED         0x00000008      /* connection is established */
304 #define MPTSF_DISCONNECTING     0x00000010      /* disconnection was attempted */
305 #define MPTSF_DISCONNECTED      0x00000020      /* has been disconnected */
306 #define MPTSF_MP_CAPABLE        0x00000040      /* connected as a MPTCP subflow */
307 #define MPTSF_MP_READY          0x00000080      /* MPTCP has been confirmed */
308 #define MPTSF_MP_DEGRADED       0x00000100      /* has lost its MPTCP capabilities */
309 #define MPTSF_PREFERRED         0x00000200      /* primary/preferred subflow */
310 #define MPTSF_SOPT_OLDVAL       0x00000400      /* old option value is valid */
311 #define MPTSF_SOPT_INPROG       0x00000800      /* sosetopt in progress */
312 #define MPTSF_FAILINGOVER       0x00001000      /* subflow not used for output */
313 #define MPTSF_ACTIVE            0x00002000      /* subflow currently in use */
314 #define MPTSF_MPCAP_CTRSET      0x00004000      /* mpcap counter */
315 #define MPTSF_CLOSED            0x00008000      /* soclose_locked has been called on this subflow */
316 #define MPTSF_TFO_REQD          0x00010000      /* TFO requested */
317 #define MPTSF_CLOSE_REQD        0x00020000      /* A close has been requested from NECP */
318 #define MPTSF_INITIAL_SUB       0x00040000      /* This is the initial subflow */
319 #define MPTSF_READ_STALL        0x00080000      /* A read-stall has been detected */
320 #define MPTSF_WRITE_STALL       0x00100000      /* A write-stall has been detected */
321 #define MPTSF_FULLY_ESTABLISHED 0x00200000      /* Subflow is fully established and it has been confirmed
322 	                                         * whether or not it supports MPTCP.
323 	                                         * No need for further middlebox-detection.
324 	                                         */
325 #define MPTSF_CELLICON_SET      0x00400000      /* This subflow set the cellicon */
326 
327 /*
328  * MPTCP states
329  * Keep in sync with bsd/dev/dtrace/scripts/mptcp.d
330  */
331 typedef enum mptcp_state {
332 	MPTCPS_CLOSED           = 0,    /* closed */
333 	MPTCPS_LISTEN           = 1,    /* not yet implemented */
334 	MPTCPS_ESTABLISHED      = 2,    /* MPTCP connection established */
335 	MPTCPS_CLOSE_WAIT       = 3,    /* rcvd DFIN, waiting for close */
336 	MPTCPS_FIN_WAIT_1       = 4,    /* have closed, sent DFIN */
337 	MPTCPS_CLOSING          = 5,    /* closed xchd DFIN, waiting DFIN ACK */
338 	MPTCPS_LAST_ACK         = 6,    /* had DFIN and close; await DFIN ACK */
339 	MPTCPS_FIN_WAIT_2       = 7,    /* have closed, DFIN is acked */
340 	MPTCPS_TIME_WAIT        = 8,    /* in 2*MSL quiet wait after close */
341 	MPTCPS_TERMINATE        = 9,    /* terminal state */
342 } mptcp_state_t;
343 
344 /*
345  * WiFi Quality states from MPTCP's perspective
346  */
347 typedef enum mptcp_wifi_quality {
348 	MPTCP_WIFI_QUALITY_GOOD,
349 	MPTCP_WIFI_QUALITY_BAD,
350 	MPTCP_WIFI_QUALITY_UNSURE,
351 } mptcp_wifi_quality_t;
352 
353 typedef u_int64_t       mptcp_key_t;
354 typedef u_int32_t       mptcp_token_t;
355 typedef u_int8_t        mptcp_addr_id;
356 
357 
358 /* Address ID list */
359 struct mptcp_subf_auth_entry {
360 	LIST_ENTRY(mptcp_subf_auth_entry) msae_next;
361 	u_int32_t       msae_laddr_rand;        /* Local nonce */
362 	u_int32_t       msae_raddr_rand;        /* Remote nonce */
363 	mptcp_addr_id   msae_laddr_id;          /* Local addr ID */
364 	mptcp_addr_id   msae_raddr_id;          /* Remote addr ID */
365 };
366 
367 /*
368  * MPTCP Protocol Control Block
369  *
370  * Protected by per-MPTCP mpt_lock.
371  * Keep in sync with bsd/dev/dtrace/scripts/mptcp.d.
372  */
373 struct mptcb {
374 	struct mptses  *mpt_mpte;               /* back ptr to MPTCP session */
375 	mptcp_state_t   mpt_state;              /* MPTCP state */
376 	uint32_t        mpt_flags;              /* see flags below */
377 	uint8_t         mpt_version;            /* MPTCP proto version */
378 	u_short         mpt_softerror;          /* error not yet reported */
379 	/*
380 	 * Authentication and metadata invariants
381 	 */
382 	mptcp_key_t     mpt_localkey;           /* in network byte order */
383 	mptcp_key_t     mpt_remotekey;          /* in network byte order */
384 	mptcp_token_t   mpt_localtoken;         /* HMAC SHA1 of local key */
385 	mptcp_token_t   mpt_remotetoken;        /* HMAC SHA1 of remote key */
386 
387 	/*
388 	 * Timer vars for scenarios where subflow level acks arrive, but
389 	 * Data ACKs do not.
390 	 */
391 	int             mpt_rxtshift;           /* num of consecutive retrans */
392 	uint64_t        mpt_rxtstart;           /* time at which rxt started */
393 	uint64_t        mpt_rtseq;              /* seq # being tracked */
394 	uint64_t        mpt_timewait;           /* timewait */
395 	uint32_t        mpt_timer_vals;         /* timer related values */
396 	/*
397 	 * Sending side
398 	 */
399 	uint64_t        mpt_snduna;             /* DSN of last unacked byte */
400 	uint64_t        mpt_sndnxt;             /* DSN of next byte to send */
401 	uint64_t        mpt_sndmax;             /* DSN of max byte sent */
402 	uint64_t        mpt_local_idsn;         /* First byte's DSN */
403 	uint32_t        mpt_sndwnd;
404 	uint64_t        mpt_sndwl1;
405 	uint64_t        mpt_sndwl2;
406 	/*
407 	 * Receiving side
408 	 */
409 	uint64_t        mpt_rcvnxt;             /* Next expected DSN */
410 	uint64_t        mpt_remote_idsn;        /* Peer's IDSN */
411 	uint64_t        mpt_rcvadv;
412 	uint32_t        mpt_rcvwnd;
413 	LIST_HEAD(, mptcp_subf_auth_entry) mpt_subauth_list; /* address IDs */
414 	/*
415 	 * Fastclose
416 	 */
417 	uint64_t        mpt_dsn_at_csum_fail;   /* MPFail Opt DSN */
418 	uint32_t        mpt_ssn_at_csum_fail;   /* MPFail Subflow Seq */
419 	/*
420 	 * Zombie handling
421 	 */
422 #define MPT_GC_TICKS            (30)
423 #define MPT_GC_TICKS_FAST       (10)
424 	int32_t         mpt_gc_ticks;           /* Used for zombie deletion */
425 
426 	uint32_t        mpt_notsent_lowat;      /* TCP_NOTSENT_LOWAT support */
427 
428 	struct tsegqe_head      mpt_segq;
429 	uint32_t        mpt_reassqlen;          /* length of reassembly queue */
430 };
431 
432 /* valid values for mpt_flags (see also notes on mpts_flags above) */
433 #define MPTCPF_CHECKSUM                 0x001   /* checksum DSS option */
434 #define MPTCPF_FALLBACK_TO_TCP          0x002   /* Fallback to TCP */
435 #define MPTCPF_JOIN_READY               0x004   /* Ready to start 2 or more subflows */
436 #define MPTCPF_RECVD_MPFAIL             0x008   /* Received MP_FAIL option */
437 #define MPTCPF_SND_64BITDSN             0x010   /* Send full 64-bit DSN */
438 #define MPTCPF_SND_64BITACK             0x020   /* Send 64-bit ACK response */
439 #define MPTCPF_RCVD_64BITACK            0x040   /* Received 64-bit Data ACK */
440 #define MPTCPF_POST_FALLBACK_SYNC       0x080   /* Post fallback resend data */
441 #define MPTCPF_FALLBACK_HEURISTIC       0x100   /* Send SYN without MP_CAPABLE due to heuristic */
442 #define MPTCPF_HEURISTIC_TRAC           0x200   /* Tracked this connection in the heuristics as a failure */
443 #define MPTCPF_REASS_INPROG             0x400   /* Reassembly is in progress */
444 
445 /* valid values for mpt_timer_vals */
446 #define MPTT_REXMT              0x01    /* Starting Retransmit Timer */
447 #define MPTT_TW                 0x02    /* Starting Timewait Timer */
448 #define MPTT_FASTCLOSE          0x04    /* Starting Fastclose wait timer */
449 
450 /* events for close FSM */
451 #define MPCE_CLOSE              0x1
452 #define MPCE_RECV_DATA_ACK      0x2
453 #define MPCE_RECV_DATA_FIN      0x4
454 
455 /* mptcb manipulation */
456 static inline struct mptcb *
tptomptp(struct tcpcb * tp)457 tptomptp(struct tcpcb *tp)
458 {
459 	return tp->t_mptcb;
460 }
461 
462 /*
463  * MPTCP control block and state structures are allocated along with
464  * the MP protocol control block; the folllowing represents the layout.
465  */
466 struct mpp_mtp {
467 	struct mppcb            mpp;            /* Multipath PCB */
468 	struct mptses           mpp_ses;        /* MPTCP session */
469 	struct mptcb            mtcb;           /* MPTCP PCB */
470 };
471 
472 #ifdef SYSCTL_DECL
473 SYSCTL_DECL(_net_inet_mptcp);
474 #endif /* SYSCTL_DECL */
475 
476 extern struct mppcbinfo mtcbinfo;
477 extern struct pr_usrreqs mptcp_usrreqs;
478 extern os_log_t mptcp_log_handle;
479 
480 /* Encryption algorithm related definitions */
481 #define HMAC_TRUNCATED_SYNACK          8
482 #define HMAC_TRUNCATED_ACK         20
483 #define HMAC_TRUNCATED_ADD_ADDR         8
484 
485 /* Mask to obtain 32-bit portion of data sequence number */
486 #define MPTCP_DATASEQ_LOW32_MASK        (0xffffffff)
487 #define MPTCP_DATASEQ_LOW32(seq)        (seq & MPTCP_DATASEQ_LOW32_MASK)
488 
489 /* Mask to obtain upper 32-bit portion of data sequence number */
490 #define MPTCP_DATASEQ_HIGH32_MASK       (0xffffffff00000000)
491 #define MPTCP_DATASEQ_HIGH32(seq)       (seq & MPTCP_DATASEQ_HIGH32_MASK)
492 
493 /* Mask to obtain 32-bit portion of data ack */
494 #define MPTCP_DATAACK_LOW32_MASK        (0xffffffff)
495 #define MPTCP_DATAACK_LOW32(ack)        (ack & MPTCP_DATAACK_LOW32_MASK)
496 
497 /*
498  * x is the 64-bit data sequence number, y the 32-bit data seq number to be
499  * extended. z is y extended to the appropriate 64-bit value.
500  * This algorithm is based on the fact that subflow level window sizes are
501  * at the maximum 2**30 (in reality, they are a lot lesser). A high throughput
502  * application sending on a large number of subflows can in theory have very
503  * large MPTCP level send and receive windows. In which case, 64 bit DSNs
504  * must be sent in place of 32 bit DSNs on wire. For us, with 2 subflows at
505  * 512K each, sequence wraparound detection can be done by checking whether
506  * the 32-bit value obtained on wire is 2**31 bytes apart from the stored
507  * lower 32-bits of the Data Sequence Number. Bogus DSNs are dropped by
508  * comparing against rwnd. Bogus DSNs within rwnd cannot be protected against
509  * and are as weak as bogus TCP sequence numbers.
510  */
511 #define MPTCP_EXTEND_DSN(x, y, z) {                                     \
512 	if ((MPTCP_DATASEQ_LOW32(x) > y) &&                             \
513 	    ((((u_int32_t)MPTCP_DATASEQ_LOW32(x)) - (u_int32_t)y) >=    \
514 	    (u_int32_t)(1U << 31))) {                                    \
515 	/* \
516 	 * y wrapped around and x and y are 2**31 bytes  apart \
517 	 */                                                             \
518 	        z = MPTCP_DATASEQ_HIGH32(x) + 0x100000000;              \
519 	        z |= y;                                                 \
520 	} else if ((MPTCP_DATASEQ_LOW32(x) < y) &&                      \
521 	    (((u_int32_t)y -                                            \
522 	    ((u_int32_t)MPTCP_DATASEQ_LOW32(x))) >=                     \
523 	    (u_int32_t)(1U << 31))) {                                    \
524 	/* \
525 	 * x wrapped around and x and y are 2**31 apart \
526 	 */                                                             \
527 	        z = MPTCP_DATASEQ_HIGH32(x) - 0x100000000;              \
528 	        z |= y;                                                 \
529 	} else {                                                        \
530 	        z = MPTCP_DATASEQ_HIGH32(x) | y;                        \
531 	}                                                               \
532 }
533 
534 extern int mptcp_enable;        /* Multipath TCP */
535 extern int mptcp_mpcap_retries; /* Multipath TCP retries */
536 extern int mptcp_join_retries;  /* Multipath TCP Join retries */
537 extern int mptcp_dss_csum;      /* Multipath DSS Option checksum */
538 extern int mptcp_fail_thresh;   /* Multipath failover thresh of retransmits */
539 extern int mptcp_subflow_keeptime; /* Multipath subflow TCP_KEEPALIVE opt */
540 extern int mptcp_developer_mode;        /* Allow aggregation mode */
541 extern uint32_t mptcp_cellicon_refcount;
542 extern uint32_t mptcp_enable_v1;
543 
544 #define MPTCP_CELLICON_TOGGLE_RATE      (5 * TCP_RETRANSHZ) /* Only toggle every 5 seconds */
545 
546 extern int tcp_jack_rxmt;       /* Join ACK retransmission value in msecs */
547 
548 extern int mptcp_reass_total_qlen;
549 
550 __BEGIN_DECLS
551 extern void mptcp_init(struct protosw *, struct domain *);
552 extern int mptcp_ctloutput(struct socket *, struct sockopt *);
553 extern int mptcp_session_create(struct mppcb *);
554 extern boolean_t mptcp_ok_to_create_subflows(struct mptcb *mp_tp);
555 extern void mptcp_check_subflows_and_add(struct mptses *mpte);
556 extern void mptcp_check_subflows_and_remove(struct mptses *mpte);
557 extern void mptcpstats_inc_switch(struct mptses *mpte, const struct mptsub *mpts);
558 extern void mptcpstats_update(struct mptcp_itf_stats *stats __counted_by(stats_count), uint16_t stats_count, const struct mptsub *mpts);
559 extern int mptcpstats_get_index_by_ifindex(struct mptcp_itf_stats *stats __counted_by(stats_count), uint16_t stats_count, u_short ifindex, boolean_t create);
560 extern struct mptses *mptcp_drop(struct mptses *mpte, struct mptcb *mp_tp, u_short errno);
561 extern struct mptses *mptcp_close(struct mptses *, struct mptcb *);
562 extern int mptcp_lock(struct socket *, int, void *);
563 extern int mptcp_unlock(struct socket *, int, void *);
564 extern lck_mtx_t *mptcp_getlock(struct socket *, int);
565 extern void mptcp_subflow_workloop(struct mptses *);
566 
567 extern void mptcp_sched_create_subflows(struct mptses *);
568 
569 extern void mptcp_finish_usrclosed(struct mptses *mpte);
570 extern struct mptopt *mptcp_sopt_alloc(void);
571 extern const char *mptcp_sopt2str(int, int);
572 extern void mptcp_sopt_free(struct mptopt *);
573 extern void mptcp_sopt_insert(struct mptses *, struct mptopt *);
574 extern void mptcp_sopt_remove(struct mptses *, struct mptopt *);
575 extern struct mptopt *mptcp_sopt_find(struct mptses *, struct sockopt *);
576 
577 extern int mptcp_subflow_add(struct mptses *, struct sockaddr *,
578     struct sockaddr *, uint32_t, sae_connid_t *);
579 extern void mptcp_subflow_del(struct mptses *, struct mptsub *);
580 
581 extern void mptcp_handle_input(struct socket *so);
582 #define MPTCP_SUBOUT_PROBING    0x01
583 extern int mptcp_subflow_output(struct mptses *mpte, struct mptsub *mpts, int flags);
584 extern void mptcp_clean_reinjectq(struct mptses *mpte);
585 extern void mptcp_subflow_shutdown(struct mptses *, struct mptsub *);
586 extern void mptcp_subflow_disconnect(struct mptses *, struct mptsub *);
587 extern int mptcp_subflow_sosetopt(struct mptses *, struct mptsub *,
588     struct mptopt *);
589 extern int mptcp_subflow_sogetopt(struct mptses *, struct socket *,
590     struct mptopt *);
591 
592 extern void mptcp_input(struct mptses *, struct mbuf *);
593 extern boolean_t mptcp_can_send_more(struct mptcb *mp_tp, boolean_t ignore_reinject);
594 extern int mptcp_output(struct mptses *);
595 extern void mptcp_close_fsm(struct mptcb *, uint32_t);
596 
597 extern void mptcp_hmac_sha1(mptcp_key_t, mptcp_key_t, u_int32_t, u_int32_t,
598     u_char sha_digest[SHA1_RESULTLEN]);
599 extern void mptcp_hmac_sha256(mptcp_key_t, mptcp_key_t, u_char* __sized_by(msglen), uint16_t msglen,
600     u_char sha_digest[SHA256_DIGEST_LENGTH]);
601 extern void mptcp_get_mpjoin_hmac(mptcp_addr_id, struct mptcb *, u_char * __sized_by(digest_len), uint8_t digest_len);
602 extern void mptcp_get_rands(mptcp_addr_id, struct mptcb *, u_int32_t *,
603     u_int32_t *);
604 extern void mptcp_set_raddr_rand(mptcp_addr_id, struct mptcb *, mptcp_addr_id,
605     u_int32_t);
606 extern int mptcp_init_remote_parms(struct mptcb *);
607 extern boolean_t mptcp_ok_to_keepalive(struct mptcb *);
608 extern void mptcp_insert_dsn(struct mppcb *, struct mbuf *);
609 extern void mptcp_output_getm_dsnmap32(struct socket *so, int off,
610     uint32_t *dsn, uint32_t *relseq,
611     uint16_t *data_len, uint16_t *dss_csum);
612 extern void mptcp_output_getm_dsnmap64(struct socket *so, int off,
613     uint64_t *dsn, uint32_t *relseq,
614     uint16_t *data_len, uint16_t *dss_csum);
615 extern void mptcp_output_getm_data_level_details(struct socket *so, int off,
616     uint16_t *data_len, uint16_t *dss_csum);
617 extern void mptcp_act_on_txfail(struct socket *);
618 extern struct mptsub *mptcp_get_subflow(struct mptses *mpte, struct mptsub **preferred);
619 extern int mptcp_get_map_for_dsn(struct socket *so, uint64_t dsn_fail, uint32_t *tcp_seq);
620 extern int32_t mptcp_adj_sendlen(struct socket *so, int32_t off);
621 extern void mptcp_sbrcv_grow(struct mptcb *mp_tp);
622 extern int32_t mptcp_sbspace(struct mptcb *);
623 extern void mptcp_notify_mpready(struct socket *);
624 extern void mptcp_notify_mpfail(struct socket *);
625 extern void mptcp_notify_close(struct socket *);
626 extern boolean_t mptcp_no_rto_spike(struct socket*);
627 extern int mptcp_set_notsent_lowat(struct mptses *mpte, int optval);
628 extern u_int32_t mptcp_get_notsent_lowat(struct mptses *mpte);
629 extern int mptcp_notsent_lowat_check(struct socket *so);
630 extern void mptcp_ask_symptoms(struct mptses *mpte);
631 extern void mptcp_control_register(void);
632 extern mptcp_wifi_quality_t mptcp_wifi_quality_for_session(struct mptses *mpte);
633 extern boolean_t symptoms_is_wifi_lossy(void);
634 extern void mptcp_session_necp_cb(void *, int, uint32_t, uint32_t, bool *);
635 extern struct sockaddr *mptcp_get_session_dst(struct mptses *mpte,
636     boolean_t has_v6, boolean_t has_v4);
637 extern void mptcp_set_restrictions(struct socket *mp_so);
638 extern void mptcp_clear_cellicon(void);
639 extern void mptcp_unset_cellicon(struct mptses *mpte, struct mptsub *mpts, uint32_t val);
640 extern void mptcp_reset_rexmit_state(struct tcpcb *tp);
641 extern void mptcp_reset_keepalive(struct tcpcb *tp);
642 extern int mptcp_validate_csum(struct tcpcb *tp, struct mbuf *m, uint64_t dsn,
643     uint32_t sseq, uint16_t dlen, uint16_t csum, int dfin);
644 __END_DECLS
645 
646 #endif /* BSD_KERNEL_PRIVATE */
647 #ifdef PRIVATE
648 
649 typedef struct mptcp_flow {
650 	uint64_t                flow_len;
651 	uint64_t                flow_tcpci_offset;
652 	uint32_t                flow_flags;
653 	sae_connid_t            flow_cid;
654 	struct sockaddr_storage flow_src;
655 	struct sockaddr_storage flow_dst;
656 	uint32_t                flow_relseq;    /* last subflow rel seq# */
657 	int32_t                 flow_soerror;   /* subflow level error */
658 	uint32_t                flow_probecnt;  /* number of probes sent */
659 	conninfo_tcp_t          flow_ci;        /* must be the last field */
660 } mptcp_flow_t;
661 
662 typedef struct conninfo_mptcp {
663 	uint64_t        mptcpci_len;
664 	uint64_t        mptcpci_flow_offset;    /* offsetof first flow */
665 	uint64_t        mptcpci_nflows;         /* number of subflows */
666 	uint32_t        mptcpci_state;          /* MPTCP level state */
667 	uint32_t        mptcpci_mpte_flags;     /* Session flags */
668 	uint32_t        mptcpci_flags;          /* MPTCB flags */
669 	uint32_t        mptcpci_ltoken;         /* local token */
670 	uint32_t        mptcpci_rtoken;         /* remote token */
671 	uint32_t        mptcpci_notsent_lowat;  /* NOTSENT_LOWAT */
672 
673 	/* Send side */
674 	uint64_t        mptcpci_snduna;         /* DSN of last unacked byte */
675 	uint64_t        mptcpci_sndnxt;         /* DSN of next byte to send */
676 	uint64_t        mptcpci_sndmax;         /* DSN of max byte sent */
677 	uint64_t        mptcpci_lidsn;          /* Local IDSN */
678 	uint32_t        mptcpci_sndwnd;         /* Send window snapshot */
679 
680 	/* Receive side */
681 	uint64_t        mptcpci_rcvnxt;         /* Next expected DSN */
682 	uint64_t        mptcpci_rcvatmark;      /* Session level rcvnxt */
683 	uint64_t        mptcpci_ridsn;          /* Peer's IDSN */
684 	uint32_t        mptcpci_rcvwnd;         /* Receive window */
685 
686 	uint8_t         mptcpci_mpte_addrid;    /* last addr id */
687 
688 	mptcp_flow_t    mptcpci_flows[1];
689 } conninfo_mptcp_t;
690 
691 /* Use SymptomsD notifications of wifi and cell status in subflow selection */
692 #define MPTCP_KERN_CTL_NAME    "com.apple.network.advisory"
693 typedef struct symptoms_advisory {
694 	union {
695 		uint32_t        sa_nwk_status_int;
696 		struct {
697 			union {
698 #define SYMPTOMS_ADVISORY_NOCOMMENT     0x0000
699 #define SYMPTOMS_ADVISORY_USEAPP        0xFFFF /* Very ugly workaround to avoid breaking backwards compatibility - ToDo: Fix it in +1 */
700 				uint16_t        sa_nwk_status;
701 				struct {
702 #define SYMPTOMS_ADVISORY_WIFI_BAD     0x01
703 #define SYMPTOMS_ADVISORY_WIFI_OK      0x02
704 					uint8_t sa_wifi_status;
705 #define SYMPTOMS_ADVISORY_CELL_BAD     0x01
706 #define SYMPTOMS_ADVISORY_CELL_OK      0x02
707 					uint8_t sa_cell_status;
708 				};
709 			};
710 			uint16_t        sa_unused;
711 		};
712 	};
713 } symptoms_advisory_t;
714 
715 #define MPTCP_TARGET_BASED_RSSI_THRESHOLD -75
716 struct mptcp_symptoms_answer {
717 	struct symptoms_advisory advisory;
718 	uuid_t  uuid;
719 	int32_t rssi;
720 };
721 
722 struct mptcp_symptoms_ask_uuid {
723 	uint32_t        cmd;
724 #define MPTCP_SYMPTOMS_ASK_UUID         1
725 	uuid_t          uuid;
726 	uint32_t        priority;
727 #define MPTCP_SYMPTOMS_UNKNOWN          0
728 #define MPTCP_SYMPTOMS_BACKGROUND       1
729 #define MPTCP_SYMPTOMS_FOREGROUND       2
730 };
731 
732 struct kev_mptcp_data {
733 	int value;
734 };
735 
736 #endif /* PRIVATE */
737 #endif /* _NETINET_MPTCP_VAR_H_ */
738