1 // SPDX-License-Identifier: GPL-2.0
2 /* Multipath TCP
3 *
4 * Copyright (c) 2021, Red Hat.
5 */
6
7 #define pr_fmt(fmt) "MPTCP: " fmt
8
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <net/sock.h>
12 #include <net/protocol.h>
13 #include <net/tcp.h>
14 #include <net/mptcp.h>
15 #include "protocol.h"
16
__mptcp_tcp_fallback(struct mptcp_sock * msk)17 static struct sock *__mptcp_tcp_fallback(struct mptcp_sock *msk)
18 {
19 sock_owned_by_me((const struct sock *)msk);
20
21 if (likely(!__mptcp_check_fallback(msk)))
22 return NULL;
23
24 return msk->first;
25 }
26
sockopt_seq_reset(const struct sock * sk)27 static u32 sockopt_seq_reset(const struct sock *sk)
28 {
29 sock_owned_by_me(sk);
30
31 /* Highbits contain state. Allows to distinguish sockopt_seq
32 * of listener and established:
33 * s0 = new_listener()
34 * sockopt(s0) - seq is 1
35 * s1 = accept(s0) - s1 inherits seq 1 if listener sk (s0)
36 * sockopt(s0) - seq increments to 2 on s0
37 * sockopt(s1) // seq increments to 2 on s1 (different option)
38 * new ssk completes join, inherits options from s0 // seq 2
39 * Needs sync from mptcp join logic, but ssk->seq == msk->seq
40 *
41 * Set High order bits to sk_state so ssk->seq == msk->seq test
42 * will fail.
43 */
44
45 return (u32)sk->sk_state << 24u;
46 }
47
sockopt_seq_inc(struct mptcp_sock * msk)48 static void sockopt_seq_inc(struct mptcp_sock *msk)
49 {
50 u32 seq = (msk->setsockopt_seq + 1) & 0x00ffffff;
51
52 msk->setsockopt_seq = sockopt_seq_reset((struct sock *)msk) + seq;
53 }
54
mptcp_get_int_option(struct mptcp_sock * msk,sockptr_t optval,unsigned int optlen,int * val)55 static int mptcp_get_int_option(struct mptcp_sock *msk, sockptr_t optval,
56 unsigned int optlen, int *val)
57 {
58 if (optlen < sizeof(int))
59 return -EINVAL;
60
61 if (copy_from_sockptr(val, optval, sizeof(*val)))
62 return -EFAULT;
63
64 return 0;
65 }
66
mptcp_sol_socket_sync_intval(struct mptcp_sock * msk,int optname,int val)67 static void mptcp_sol_socket_sync_intval(struct mptcp_sock *msk, int optname, int val)
68 {
69 struct mptcp_subflow_context *subflow;
70 struct sock *sk = (struct sock *)msk;
71
72 lock_sock(sk);
73 sockopt_seq_inc(msk);
74
75 mptcp_for_each_subflow(msk, subflow) {
76 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
77 bool slow = lock_sock_fast(ssk);
78
79 switch (optname) {
80 case SO_DEBUG:
81 sock_valbool_flag(ssk, SOCK_DBG, !!val);
82 break;
83 case SO_KEEPALIVE:
84 if (ssk->sk_prot->keepalive)
85 ssk->sk_prot->keepalive(ssk, !!val);
86 sock_valbool_flag(ssk, SOCK_KEEPOPEN, !!val);
87 break;
88 case SO_PRIORITY:
89 ssk->sk_priority = val;
90 break;
91 case SO_SNDBUF:
92 case SO_SNDBUFFORCE:
93 ssk->sk_userlocks |= SOCK_SNDBUF_LOCK;
94 WRITE_ONCE(ssk->sk_sndbuf, sk->sk_sndbuf);
95 break;
96 case SO_RCVBUF:
97 case SO_RCVBUFFORCE:
98 ssk->sk_userlocks |= SOCK_RCVBUF_LOCK;
99 WRITE_ONCE(ssk->sk_rcvbuf, sk->sk_rcvbuf);
100 break;
101 case SO_MARK:
102 if (READ_ONCE(ssk->sk_mark) != sk->sk_mark) {
103 ssk->sk_mark = sk->sk_mark;
104 sk_dst_reset(ssk);
105 }
106 break;
107 case SO_INCOMING_CPU:
108 WRITE_ONCE(ssk->sk_incoming_cpu, val);
109 break;
110 }
111
112 subflow->setsockopt_seq = msk->setsockopt_seq;
113 unlock_sock_fast(ssk, slow);
114 }
115
116 release_sock(sk);
117 }
118
mptcp_sol_socket_intval(struct mptcp_sock * msk,int optname,int val)119 static int mptcp_sol_socket_intval(struct mptcp_sock *msk, int optname, int val)
120 {
121 sockptr_t optval = KERNEL_SOCKPTR(&val);
122 struct sock *sk = (struct sock *)msk;
123 int ret;
124
125 ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname,
126 optval, sizeof(val));
127 if (ret)
128 return ret;
129
130 mptcp_sol_socket_sync_intval(msk, optname, val);
131 return 0;
132 }
133
mptcp_so_incoming_cpu(struct mptcp_sock * msk,int val)134 static void mptcp_so_incoming_cpu(struct mptcp_sock *msk, int val)
135 {
136 struct sock *sk = (struct sock *)msk;
137
138 WRITE_ONCE(sk->sk_incoming_cpu, val);
139
140 mptcp_sol_socket_sync_intval(msk, SO_INCOMING_CPU, val);
141 }
142
mptcp_setsockopt_sol_socket_tstamp(struct mptcp_sock * msk,int optname,int val)143 static int mptcp_setsockopt_sol_socket_tstamp(struct mptcp_sock *msk, int optname, int val)
144 {
145 sockptr_t optval = KERNEL_SOCKPTR(&val);
146 struct mptcp_subflow_context *subflow;
147 struct sock *sk = (struct sock *)msk;
148 int ret;
149
150 ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname,
151 optval, sizeof(val));
152 if (ret)
153 return ret;
154
155 lock_sock(sk);
156 mptcp_for_each_subflow(msk, subflow) {
157 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
158 bool slow = lock_sock_fast(ssk);
159
160 sock_set_timestamp(sk, optname, !!val);
161 unlock_sock_fast(ssk, slow);
162 }
163
164 release_sock(sk);
165 return 0;
166 }
167
mptcp_setsockopt_sol_socket_int(struct mptcp_sock * msk,int optname,sockptr_t optval,unsigned int optlen)168 static int mptcp_setsockopt_sol_socket_int(struct mptcp_sock *msk, int optname,
169 sockptr_t optval,
170 unsigned int optlen)
171 {
172 int val, ret;
173
174 ret = mptcp_get_int_option(msk, optval, optlen, &val);
175 if (ret)
176 return ret;
177
178 switch (optname) {
179 case SO_KEEPALIVE:
180 mptcp_sol_socket_sync_intval(msk, optname, val);
181 return 0;
182 case SO_DEBUG:
183 case SO_MARK:
184 case SO_PRIORITY:
185 case SO_SNDBUF:
186 case SO_SNDBUFFORCE:
187 case SO_RCVBUF:
188 case SO_RCVBUFFORCE:
189 return mptcp_sol_socket_intval(msk, optname, val);
190 case SO_INCOMING_CPU:
191 mptcp_so_incoming_cpu(msk, val);
192 return 0;
193 case SO_TIMESTAMP_OLD:
194 case SO_TIMESTAMP_NEW:
195 case SO_TIMESTAMPNS_OLD:
196 case SO_TIMESTAMPNS_NEW:
197 return mptcp_setsockopt_sol_socket_tstamp(msk, optname, val);
198 }
199
200 return -ENOPROTOOPT;
201 }
202
mptcp_setsockopt_sol_socket_timestamping(struct mptcp_sock * msk,int optname,sockptr_t optval,unsigned int optlen)203 static int mptcp_setsockopt_sol_socket_timestamping(struct mptcp_sock *msk,
204 int optname,
205 sockptr_t optval,
206 unsigned int optlen)
207 {
208 struct mptcp_subflow_context *subflow;
209 struct sock *sk = (struct sock *)msk;
210 struct so_timestamping timestamping;
211 int ret;
212
213 if (optlen == sizeof(timestamping)) {
214 if (copy_from_sockptr(×tamping, optval,
215 sizeof(timestamping)))
216 return -EFAULT;
217 } else if (optlen == sizeof(int)) {
218 memset(×tamping, 0, sizeof(timestamping));
219
220 if (copy_from_sockptr(×tamping.flags, optval, sizeof(int)))
221 return -EFAULT;
222 } else {
223 return -EINVAL;
224 }
225
226 ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname,
227 KERNEL_SOCKPTR(×tamping),
228 sizeof(timestamping));
229 if (ret)
230 return ret;
231
232 lock_sock(sk);
233
234 mptcp_for_each_subflow(msk, subflow) {
235 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
236 bool slow = lock_sock_fast(ssk);
237
238 sock_set_timestamping(sk, optname, timestamping);
239 unlock_sock_fast(ssk, slow);
240 }
241
242 release_sock(sk);
243
244 return 0;
245 }
246
mptcp_setsockopt_sol_socket_linger(struct mptcp_sock * msk,sockptr_t optval,unsigned int optlen)247 static int mptcp_setsockopt_sol_socket_linger(struct mptcp_sock *msk, sockptr_t optval,
248 unsigned int optlen)
249 {
250 struct mptcp_subflow_context *subflow;
251 struct sock *sk = (struct sock *)msk;
252 struct linger ling;
253 sockptr_t kopt;
254 int ret;
255
256 if (optlen < sizeof(ling))
257 return -EINVAL;
258
259 if (copy_from_sockptr(&ling, optval, sizeof(ling)))
260 return -EFAULT;
261
262 kopt = KERNEL_SOCKPTR(&ling);
263 ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, SO_LINGER, kopt, sizeof(ling));
264 if (ret)
265 return ret;
266
267 lock_sock(sk);
268 sockopt_seq_inc(msk);
269 mptcp_for_each_subflow(msk, subflow) {
270 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
271 bool slow = lock_sock_fast(ssk);
272
273 if (!ling.l_onoff) {
274 sock_reset_flag(ssk, SOCK_LINGER);
275 } else {
276 ssk->sk_lingertime = sk->sk_lingertime;
277 sock_set_flag(ssk, SOCK_LINGER);
278 }
279
280 subflow->setsockopt_seq = msk->setsockopt_seq;
281 unlock_sock_fast(ssk, slow);
282 }
283
284 release_sock(sk);
285 return 0;
286 }
287
mptcp_setsockopt_sol_socket(struct mptcp_sock * msk,int optname,sockptr_t optval,unsigned int optlen)288 static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname,
289 sockptr_t optval, unsigned int optlen)
290 {
291 struct sock *sk = (struct sock *)msk;
292 struct socket *ssock;
293 int ret;
294
295 switch (optname) {
296 case SO_REUSEPORT:
297 case SO_REUSEADDR:
298 case SO_BINDTODEVICE:
299 case SO_BINDTOIFINDEX:
300 lock_sock(sk);
301 ssock = __mptcp_nmpc_socket(msk);
302 if (!ssock) {
303 release_sock(sk);
304 return -EINVAL;
305 }
306
307 ret = sock_setsockopt(ssock, SOL_SOCKET, optname, optval, optlen);
308 if (ret == 0) {
309 if (optname == SO_REUSEPORT)
310 sk->sk_reuseport = ssock->sk->sk_reuseport;
311 else if (optname == SO_REUSEADDR)
312 sk->sk_reuse = ssock->sk->sk_reuse;
313 else if (optname == SO_BINDTODEVICE)
314 sk->sk_bound_dev_if = ssock->sk->sk_bound_dev_if;
315 else if (optname == SO_BINDTOIFINDEX)
316 sk->sk_bound_dev_if = ssock->sk->sk_bound_dev_if;
317 }
318 release_sock(sk);
319 return ret;
320 case SO_KEEPALIVE:
321 case SO_PRIORITY:
322 case SO_SNDBUF:
323 case SO_SNDBUFFORCE:
324 case SO_RCVBUF:
325 case SO_RCVBUFFORCE:
326 case SO_MARK:
327 case SO_INCOMING_CPU:
328 case SO_DEBUG:
329 case SO_TIMESTAMP_OLD:
330 case SO_TIMESTAMP_NEW:
331 case SO_TIMESTAMPNS_OLD:
332 case SO_TIMESTAMPNS_NEW:
333 return mptcp_setsockopt_sol_socket_int(msk, optname, optval,
334 optlen);
335 case SO_TIMESTAMPING_OLD:
336 case SO_TIMESTAMPING_NEW:
337 return mptcp_setsockopt_sol_socket_timestamping(msk, optname,
338 optval, optlen);
339 case SO_LINGER:
340 return mptcp_setsockopt_sol_socket_linger(msk, optval, optlen);
341 case SO_RCVLOWAT:
342 case SO_RCVTIMEO_OLD:
343 case SO_RCVTIMEO_NEW:
344 case SO_BUSY_POLL:
345 case SO_PREFER_BUSY_POLL:
346 case SO_BUSY_POLL_BUDGET:
347 /* No need to copy: only relevant for msk */
348 return sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, optval, optlen);
349 case SO_NO_CHECK:
350 case SO_DONTROUTE:
351 case SO_BROADCAST:
352 case SO_BSDCOMPAT:
353 case SO_PASSCRED:
354 case SO_PASSSEC:
355 case SO_RXQ_OVFL:
356 case SO_WIFI_STATUS:
357 case SO_NOFCS:
358 case SO_SELECT_ERR_QUEUE:
359 return 0;
360 }
361
362 /* SO_OOBINLINE is not supported, let's avoid the related mess
363 * SO_ATTACH_FILTER, SO_ATTACH_BPF, SO_ATTACH_REUSEPORT_CBPF,
364 * SO_DETACH_REUSEPORT_BPF, SO_DETACH_FILTER, SO_LOCK_FILTER,
365 * we must be careful with subflows
366 *
367 * SO_ATTACH_REUSEPORT_EBPF is not supported, at it checks
368 * explicitly the sk_protocol field
369 *
370 * SO_PEEK_OFF is unsupported, as it is for plain TCP
371 * SO_MAX_PACING_RATE is unsupported, we must be careful with subflows
372 * SO_CNX_ADVICE is currently unsupported, could possibly be relevant,
373 * but likely needs careful design
374 *
375 * SO_ZEROCOPY is currently unsupported, TODO in sndmsg
376 * SO_TXTIME is currently unsupported
377 */
378
379 return -EOPNOTSUPP;
380 }
381
mptcp_setsockopt_v6(struct mptcp_sock * msk,int optname,sockptr_t optval,unsigned int optlen)382 static int mptcp_setsockopt_v6(struct mptcp_sock *msk, int optname,
383 sockptr_t optval, unsigned int optlen)
384 {
385 struct sock *sk = (struct sock *)msk;
386 int ret = -EOPNOTSUPP;
387 struct socket *ssock;
388
389 switch (optname) {
390 case IPV6_V6ONLY:
391 lock_sock(sk);
392 ssock = __mptcp_nmpc_socket(msk);
393 if (!ssock) {
394 release_sock(sk);
395 return -EINVAL;
396 }
397
398 ret = tcp_setsockopt(ssock->sk, SOL_IPV6, optname, optval, optlen);
399 if (ret == 0)
400 sk->sk_ipv6only = ssock->sk->sk_ipv6only;
401
402 release_sock(sk);
403 break;
404 }
405
406 return ret;
407 }
408
mptcp_supported_sockopt(int level,int optname)409 static bool mptcp_supported_sockopt(int level, int optname)
410 {
411 if (level == SOL_IP) {
412 switch (optname) {
413 /* should work fine */
414 case IP_FREEBIND:
415 case IP_TRANSPARENT:
416
417 /* the following are control cmsg related */
418 case IP_PKTINFO:
419 case IP_RECVTTL:
420 case IP_RECVTOS:
421 case IP_RECVOPTS:
422 case IP_RETOPTS:
423 case IP_PASSSEC:
424 case IP_RECVORIGDSTADDR:
425 case IP_CHECKSUM:
426 case IP_RECVFRAGSIZE:
427
428 /* common stuff that need some love */
429 case IP_TOS:
430 case IP_TTL:
431 case IP_BIND_ADDRESS_NO_PORT:
432 case IP_MTU_DISCOVER:
433 case IP_RECVERR:
434
435 /* possibly less common may deserve some love */
436 case IP_MINTTL:
437
438 /* the following is apparently a no-op for plain TCP */
439 case IP_RECVERR_RFC4884:
440 return true;
441 }
442
443 /* IP_OPTIONS is not supported, needs subflow care */
444 /* IP_HDRINCL, IP_NODEFRAG are not supported, RAW specific */
445 /* IP_MULTICAST_TTL, IP_MULTICAST_LOOP, IP_UNICAST_IF,
446 * IP_ADD_MEMBERSHIP, IP_ADD_SOURCE_MEMBERSHIP, IP_DROP_MEMBERSHIP,
447 * IP_DROP_SOURCE_MEMBERSHIP, IP_BLOCK_SOURCE, IP_UNBLOCK_SOURCE,
448 * MCAST_JOIN_GROUP, MCAST_LEAVE_GROUP MCAST_JOIN_SOURCE_GROUP,
449 * MCAST_LEAVE_SOURCE_GROUP, MCAST_BLOCK_SOURCE, MCAST_UNBLOCK_SOURCE,
450 * MCAST_MSFILTER, IP_MULTICAST_ALL are not supported, better not deal
451 * with mcast stuff
452 */
453 /* IP_IPSEC_POLICY, IP_XFRM_POLICY are nut supported, unrelated here */
454 return false;
455 }
456 if (level == SOL_IPV6) {
457 switch (optname) {
458 case IPV6_V6ONLY:
459
460 /* the following are control cmsg related */
461 case IPV6_RECVPKTINFO:
462 case IPV6_2292PKTINFO:
463 case IPV6_RECVHOPLIMIT:
464 case IPV6_2292HOPLIMIT:
465 case IPV6_RECVRTHDR:
466 case IPV6_2292RTHDR:
467 case IPV6_RECVHOPOPTS:
468 case IPV6_2292HOPOPTS:
469 case IPV6_RECVDSTOPTS:
470 case IPV6_2292DSTOPTS:
471 case IPV6_RECVTCLASS:
472 case IPV6_FLOWINFO:
473 case IPV6_RECVPATHMTU:
474 case IPV6_RECVORIGDSTADDR:
475 case IPV6_RECVFRAGSIZE:
476
477 /* the following ones need some love but are quite common */
478 case IPV6_TCLASS:
479 case IPV6_TRANSPARENT:
480 case IPV6_FREEBIND:
481 case IPV6_PKTINFO:
482 case IPV6_2292PKTOPTIONS:
483 case IPV6_UNICAST_HOPS:
484 case IPV6_MTU_DISCOVER:
485 case IPV6_MTU:
486 case IPV6_RECVERR:
487 case IPV6_FLOWINFO_SEND:
488 case IPV6_FLOWLABEL_MGR:
489 case IPV6_MINHOPCOUNT:
490 case IPV6_DONTFRAG:
491 case IPV6_AUTOFLOWLABEL:
492
493 /* the following one is a no-op for plain TCP */
494 case IPV6_RECVERR_RFC4884:
495 return true;
496 }
497
498 /* IPV6_HOPOPTS, IPV6_RTHDRDSTOPTS, IPV6_RTHDR, IPV6_DSTOPTS are
499 * not supported
500 */
501 /* IPV6_MULTICAST_HOPS, IPV6_MULTICAST_LOOP, IPV6_UNICAST_IF,
502 * IPV6_MULTICAST_IF, IPV6_ADDRFORM,
503 * IPV6_ADD_MEMBERSHIP, IPV6_DROP_MEMBERSHIP, IPV6_JOIN_ANYCAST,
504 * IPV6_LEAVE_ANYCAST, IPV6_MULTICAST_ALL, MCAST_JOIN_GROUP, MCAST_LEAVE_GROUP,
505 * MCAST_JOIN_SOURCE_GROUP, MCAST_LEAVE_SOURCE_GROUP,
506 * MCAST_BLOCK_SOURCE, MCAST_UNBLOCK_SOURCE, MCAST_MSFILTER
507 * are not supported better not deal with mcast
508 */
509 /* IPV6_ROUTER_ALERT, IPV6_ROUTER_ALERT_ISOLATE are not supported, since are evil */
510
511 /* IPV6_IPSEC_POLICY, IPV6_XFRM_POLICY are not supported */
512 /* IPV6_ADDR_PREFERENCES is not supported, we must be careful with subflows */
513 return false;
514 }
515 if (level == SOL_TCP) {
516 switch (optname) {
517 /* the following are no-op or should work just fine */
518 case TCP_THIN_DUPACK:
519 case TCP_DEFER_ACCEPT:
520
521 /* the following need some love */
522 case TCP_MAXSEG:
523 case TCP_NODELAY:
524 case TCP_THIN_LINEAR_TIMEOUTS:
525 case TCP_CONGESTION:
526 case TCP_ULP:
527 case TCP_CORK:
528 case TCP_KEEPIDLE:
529 case TCP_KEEPINTVL:
530 case TCP_KEEPCNT:
531 case TCP_SYNCNT:
532 case TCP_SAVE_SYN:
533 case TCP_LINGER2:
534 case TCP_WINDOW_CLAMP:
535 case TCP_QUICKACK:
536 case TCP_USER_TIMEOUT:
537 case TCP_TIMESTAMP:
538 case TCP_NOTSENT_LOWAT:
539 case TCP_TX_DELAY:
540 return true;
541 }
542
543 /* TCP_MD5SIG, TCP_MD5SIG_EXT are not supported, MD5 is not compatible with MPTCP */
544
545 /* TCP_REPAIR, TCP_REPAIR_QUEUE, TCP_QUEUE_SEQ, TCP_REPAIR_OPTIONS,
546 * TCP_REPAIR_WINDOW are not supported, better avoid this mess
547 */
548 /* TCP_FASTOPEN_KEY, TCP_FASTOPEN TCP_FASTOPEN_CONNECT, TCP_FASTOPEN_NO_COOKIE,
549 * are not supported fastopen is currently unsupported
550 */
551 /* TCP_INQ is currently unsupported, needs some recvmsg work */
552 }
553 return false;
554 }
555
mptcp_setsockopt_sol_tcp_congestion(struct mptcp_sock * msk,sockptr_t optval,unsigned int optlen)556 static int mptcp_setsockopt_sol_tcp_congestion(struct mptcp_sock *msk, sockptr_t optval,
557 unsigned int optlen)
558 {
559 struct mptcp_subflow_context *subflow;
560 struct sock *sk = (struct sock *)msk;
561 char name[TCP_CA_NAME_MAX];
562 bool cap_net_admin;
563 int ret;
564
565 if (optlen < 1)
566 return -EINVAL;
567
568 ret = strncpy_from_sockptr(name, optval,
569 min_t(long, TCP_CA_NAME_MAX - 1, optlen));
570 if (ret < 0)
571 return -EFAULT;
572
573 name[ret] = 0;
574
575 cap_net_admin = ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN);
576
577 ret = 0;
578 lock_sock(sk);
579 sockopt_seq_inc(msk);
580 mptcp_for_each_subflow(msk, subflow) {
581 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
582 int err;
583
584 lock_sock(ssk);
585 err = tcp_set_congestion_control(ssk, name, true, cap_net_admin);
586 if (err < 0 && ret == 0)
587 ret = err;
588 subflow->setsockopt_seq = msk->setsockopt_seq;
589 release_sock(ssk);
590 }
591
592 if (ret == 0)
593 strcpy(msk->ca_name, name);
594
595 release_sock(sk);
596 return ret;
597 }
598
mptcp_setsockopt_sol_tcp(struct mptcp_sock * msk,int optname,sockptr_t optval,unsigned int optlen)599 static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
600 sockptr_t optval, unsigned int optlen)
601 {
602 switch (optname) {
603 case TCP_ULP:
604 return -EOPNOTSUPP;
605 case TCP_CONGESTION:
606 return mptcp_setsockopt_sol_tcp_congestion(msk, optval, optlen);
607 }
608
609 return -EOPNOTSUPP;
610 }
611
mptcp_setsockopt(struct sock * sk,int level,int optname,sockptr_t optval,unsigned int optlen)612 int mptcp_setsockopt(struct sock *sk, int level, int optname,
613 sockptr_t optval, unsigned int optlen)
614 {
615 struct mptcp_sock *msk = mptcp_sk(sk);
616 struct sock *ssk;
617
618 pr_debug("msk=%p", msk);
619
620 if (level == SOL_SOCKET)
621 return mptcp_setsockopt_sol_socket(msk, optname, optval, optlen);
622
623 if (!mptcp_supported_sockopt(level, optname))
624 return -ENOPROTOOPT;
625
626 /* @@ the meaning of setsockopt() when the socket is connected and
627 * there are multiple subflows is not yet defined. It is up to the
628 * MPTCP-level socket to configure the subflows until the subflow
629 * is in TCP fallback, when TCP socket options are passed through
630 * to the one remaining subflow.
631 */
632 lock_sock(sk);
633 ssk = __mptcp_tcp_fallback(msk);
634 release_sock(sk);
635 if (ssk)
636 return tcp_setsockopt(ssk, level, optname, optval, optlen);
637
638 if (level == SOL_IPV6)
639 return mptcp_setsockopt_v6(msk, optname, optval, optlen);
640
641 if (level == SOL_TCP)
642 return mptcp_setsockopt_sol_tcp(msk, optname, optval, optlen);
643
644 return -EOPNOTSUPP;
645 }
646
mptcp_getsockopt_first_sf_only(struct mptcp_sock * msk,int level,int optname,char __user * optval,int __user * optlen)647 static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int optname,
648 char __user *optval, int __user *optlen)
649 {
650 struct sock *sk = (struct sock *)msk;
651 struct socket *ssock;
652 int ret = -EINVAL;
653 struct sock *ssk;
654
655 lock_sock(sk);
656 ssk = msk->first;
657 if (ssk) {
658 ret = tcp_getsockopt(ssk, level, optname, optval, optlen);
659 goto out;
660 }
661
662 ssock = __mptcp_nmpc_socket(msk);
663 if (!ssock)
664 goto out;
665
666 ret = tcp_getsockopt(ssock->sk, level, optname, optval, optlen);
667
668 out:
669 release_sock(sk);
670 return ret;
671 }
672
mptcp_getsockopt_sol_tcp(struct mptcp_sock * msk,int optname,char __user * optval,int __user * optlen)673 static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname,
674 char __user *optval, int __user *optlen)
675 {
676 switch (optname) {
677 case TCP_ULP:
678 case TCP_CONGESTION:
679 case TCP_INFO:
680 case TCP_CC_INFO:
681 return mptcp_getsockopt_first_sf_only(msk, SOL_TCP, optname,
682 optval, optlen);
683 }
684 return -EOPNOTSUPP;
685 }
686
mptcp_getsockopt(struct sock * sk,int level,int optname,char __user * optval,int __user * option)687 int mptcp_getsockopt(struct sock *sk, int level, int optname,
688 char __user *optval, int __user *option)
689 {
690 struct mptcp_sock *msk = mptcp_sk(sk);
691 struct sock *ssk;
692
693 pr_debug("msk=%p", msk);
694
695 /* @@ the meaning of setsockopt() when the socket is connected and
696 * there are multiple subflows is not yet defined. It is up to the
697 * MPTCP-level socket to configure the subflows until the subflow
698 * is in TCP fallback, when socket options are passed through
699 * to the one remaining subflow.
700 */
701 lock_sock(sk);
702 ssk = __mptcp_tcp_fallback(msk);
703 release_sock(sk);
704 if (ssk)
705 return tcp_getsockopt(ssk, level, optname, optval, option);
706
707 if (level == SOL_TCP)
708 return mptcp_getsockopt_sol_tcp(msk, optname, optval, option);
709 return -EOPNOTSUPP;
710 }
711
sync_socket_options(struct mptcp_sock * msk,struct sock * ssk)712 static void sync_socket_options(struct mptcp_sock *msk, struct sock *ssk)
713 {
714 static const unsigned int tx_rx_locks = SOCK_RCVBUF_LOCK | SOCK_SNDBUF_LOCK;
715 struct sock *sk = (struct sock *)msk;
716
717 if (ssk->sk_prot->keepalive) {
718 if (sock_flag(sk, SOCK_KEEPOPEN))
719 ssk->sk_prot->keepalive(ssk, 1);
720 else
721 ssk->sk_prot->keepalive(ssk, 0);
722 }
723
724 ssk->sk_priority = sk->sk_priority;
725 ssk->sk_bound_dev_if = sk->sk_bound_dev_if;
726 ssk->sk_incoming_cpu = sk->sk_incoming_cpu;
727
728 if (sk->sk_userlocks & tx_rx_locks) {
729 ssk->sk_userlocks |= sk->sk_userlocks & tx_rx_locks;
730 if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
731 WRITE_ONCE(ssk->sk_sndbuf, sk->sk_sndbuf);
732 if (sk->sk_userlocks & SOCK_RCVBUF_LOCK)
733 WRITE_ONCE(ssk->sk_rcvbuf, sk->sk_rcvbuf);
734 }
735
736 if (sock_flag(sk, SOCK_LINGER)) {
737 ssk->sk_lingertime = sk->sk_lingertime;
738 sock_set_flag(ssk, SOCK_LINGER);
739 } else {
740 sock_reset_flag(ssk, SOCK_LINGER);
741 }
742
743 if (sk->sk_mark != ssk->sk_mark) {
744 ssk->sk_mark = sk->sk_mark;
745 sk_dst_reset(ssk);
746 }
747
748 sock_valbool_flag(ssk, SOCK_DBG, sock_flag(sk, SOCK_DBG));
749
750 if (inet_csk(sk)->icsk_ca_ops != inet_csk(ssk)->icsk_ca_ops)
751 tcp_set_congestion_control(ssk, msk->ca_name, false, true);
752 }
753
__mptcp_sockopt_sync(struct mptcp_sock * msk,struct sock * ssk)754 static void __mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk)
755 {
756 bool slow = lock_sock_fast(ssk);
757
758 sync_socket_options(msk, ssk);
759
760 unlock_sock_fast(ssk, slow);
761 }
762
mptcp_sockopt_sync(struct mptcp_sock * msk,struct sock * ssk)763 void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk)
764 {
765 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
766
767 msk_owned_by_me(msk);
768
769 if (READ_ONCE(subflow->setsockopt_seq) != msk->setsockopt_seq) {
770 __mptcp_sockopt_sync(msk, ssk);
771
772 subflow->setsockopt_seq = msk->setsockopt_seq;
773 }
774 }
775
mptcp_sockopt_sync_all(struct mptcp_sock * msk)776 void mptcp_sockopt_sync_all(struct mptcp_sock *msk)
777 {
778 struct mptcp_subflow_context *subflow;
779 struct sock *sk = (struct sock *)msk;
780 u32 seq;
781
782 seq = sockopt_seq_reset(sk);
783
784 mptcp_for_each_subflow(msk, subflow) {
785 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
786 u32 sseq = READ_ONCE(subflow->setsockopt_seq);
787
788 if (sseq != msk->setsockopt_seq) {
789 __mptcp_sockopt_sync(msk, ssk);
790 WRITE_ONCE(subflow->setsockopt_seq, seq);
791 } else if (sseq != seq) {
792 WRITE_ONCE(subflow->setsockopt_seq, seq);
793 }
794
795 cond_resched();
796 }
797
798 msk->setsockopt_seq = seq;
799 }
800
