1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * INET An implementation of the TCP/IP protocol suite for the LINUX |
4 | * operating system. INET is implemented using the BSD Socket |
5 | * interface as the means of communication with the user level. |
6 | * |
7 | * Implementation of the Transmission Control Protocol(TCP). |
8 | * |
9 | * IPv4 specific functions |
10 | * |
11 | * code split from: |
12 | * linux/ipv4/tcp.c |
13 | * linux/ipv4/tcp_input.c |
14 | * linux/ipv4/tcp_output.c |
15 | * |
16 | * See tcp.c for author information |
17 | */ |
18 | |
19 | /* |
20 | * Changes: |
21 | * David S. Miller : New socket lookup architecture. |
22 | * This code is dedicated to John Dyson. |
23 | * David S. Miller : Change semantics of established hash, |
24 | * half is devoted to TIME_WAIT sockets |
25 | * and the rest go in the other half. |
26 | * Andi Kleen : Add support for syncookies and fixed |
27 | * some bugs: ip options weren't passed to |
28 | * the TCP layer, missed a check for an |
29 | * ACK bit. |
30 | * Andi Kleen : Implemented fast path mtu discovery. |
31 | * Fixed many serious bugs in the |
32 | * request_sock handling and moved |
33 | * most of it into the af independent code. |
34 | * Added tail drop and some other bugfixes. |
35 | * Added new listen semantics. |
36 | * Mike McLagan : Routing by source |
37 | * Juan Jose Ciarlante: ip_dynaddr bits |
38 | * Andi Kleen: various fixes. |
39 | * Vitaly E. Lavrov : Transparent proxy revived after year |
40 | * coma. |
41 | * Andi Kleen : Fix new listen. |
42 | * Andi Kleen : Fix accept error reporting. |
43 | * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which |
44 | * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind |
45 | * a single port at the same time. |
46 | */ |
47 | |
48 | #define pr_fmt(fmt) "TCP: " fmt |
49 | |
50 | #include <linux/bottom_half.h> |
51 | #include <linux/types.h> |
52 | #include <linux/fcntl.h> |
53 | #include <linux/module.h> |
54 | #include <linux/random.h> |
55 | #include <linux/cache.h> |
56 | #include <linux/jhash.h> |
57 | #include <linux/init.h> |
58 | #include <linux/times.h> |
59 | #include <linux/slab.h> |
60 | #include <linux/sched.h> |
61 | |
62 | #include <net/net_namespace.h> |
63 | #include <net/icmp.h> |
64 | #include <net/inet_hashtables.h> |
65 | #include <net/tcp.h> |
66 | #include <net/transp_v6.h> |
67 | #include <net/ipv6.h> |
68 | #include <net/inet_common.h> |
69 | #include <net/timewait_sock.h> |
70 | #include <net/xfrm.h> |
71 | #include <net/secure_seq.h> |
72 | #include <net/busy_poll.h> |
73 | |
74 | #include <linux/inet.h> |
75 | #include <linux/ipv6.h> |
76 | #include <linux/stddef.h> |
77 | #include <linux/proc_fs.h> |
78 | #include <linux/seq_file.h> |
79 | #include <linux/inetdevice.h> |
80 | #include <linux/btf_ids.h> |
81 | |
82 | #include <crypto/hash.h> |
83 | #include <linux/scatterlist.h> |
84 | |
85 | #include <trace/events/tcp.h> |
86 | |
87 | #ifdef CONFIG_TCP_MD5SIG |
88 | static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, |
89 | __be32 daddr, __be32 saddr, const struct tcphdr *th); |
90 | #endif |
91 | |
92 | struct inet_hashinfo tcp_hashinfo; |
93 | EXPORT_SYMBOL(tcp_hashinfo); |
94 | |
95 | static DEFINE_PER_CPU(struct sock *, ipv4_tcp_sk); |
96 | |
97 | static u32 tcp_v4_init_seq(const struct sk_buff *skb) |
98 | { |
99 | return secure_tcp_seq(saddr: ip_hdr(skb)->daddr, |
100 | daddr: ip_hdr(skb)->saddr, |
101 | sport: tcp_hdr(skb)->dest, |
102 | dport: tcp_hdr(skb)->source); |
103 | } |
104 | |
105 | static u32 tcp_v4_init_ts_off(const struct net *net, const struct sk_buff *skb) |
106 | { |
107 | return secure_tcp_ts_off(net, saddr: ip_hdr(skb)->daddr, daddr: ip_hdr(skb)->saddr); |
108 | } |
109 | |
110 | int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) |
111 | { |
112 | int reuse = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_tw_reuse); |
113 | const struct inet_timewait_sock *tw = inet_twsk(sk: sktw); |
114 | const struct tcp_timewait_sock *tcptw = tcp_twsk(sk: sktw); |
115 | struct tcp_sock *tp = tcp_sk(sk); |
116 | |
117 | if (reuse == 2) { |
118 | /* Still does not detect *everything* that goes through |
119 | * lo, since we require a loopback src or dst address |
120 | * or direct binding to 'lo' interface. |
121 | */ |
122 | bool loopback = false; |
123 | if (tw->tw_bound_dev_if == LOOPBACK_IFINDEX) |
124 | loopback = true; |
125 | #if IS_ENABLED(CONFIG_IPV6) |
126 | if (tw->tw_family == AF_INET6) { |
127 | if (ipv6_addr_loopback(a: &tw->tw_v6_daddr) || |
128 | ipv6_addr_v4mapped_loopback(a: &tw->tw_v6_daddr) || |
129 | ipv6_addr_loopback(a: &tw->tw_v6_rcv_saddr) || |
130 | ipv6_addr_v4mapped_loopback(a: &tw->tw_v6_rcv_saddr)) |
131 | loopback = true; |
132 | } else |
133 | #endif |
134 | { |
135 | if (ipv4_is_loopback(addr: tw->tw_daddr) || |
136 | ipv4_is_loopback(addr: tw->tw_rcv_saddr)) |
137 | loopback = true; |
138 | } |
139 | if (!loopback) |
140 | reuse = 0; |
141 | } |
142 | |
143 | /* With PAWS, it is safe from the viewpoint |
144 | of data integrity. Even without PAWS it is safe provided sequence |
145 | spaces do not overlap i.e. at data rates <= 80Mbit/sec. |
146 | |
147 | Actually, the idea is close to VJ's one, only timestamp cache is |
148 | held not per host, but per port pair and TW bucket is used as state |
149 | holder. |
150 | |
151 | If TW bucket has been already destroyed we fall back to VJ's scheme |
152 | and use initial timestamp retrieved from peer table. |
153 | */ |
154 | if (tcptw->tw_ts_recent_stamp && |
155 | (!twp || (reuse && time_after32(ktime_get_seconds(), |
156 | tcptw->tw_ts_recent_stamp)))) { |
157 | /* In case of repair and re-using TIME-WAIT sockets we still |
158 | * want to be sure that it is safe as above but honor the |
159 | * sequence numbers and time stamps set as part of the repair |
160 | * process. |
161 | * |
162 | * Without this check re-using a TIME-WAIT socket with TCP |
163 | * repair would accumulate a -1 on the repair assigned |
164 | * sequence number. The first time it is reused the sequence |
165 | * is -1, the second time -2, etc. This fixes that issue |
166 | * without appearing to create any others. |
167 | */ |
168 | if (likely(!tp->repair)) { |
169 | u32 seq = tcptw->tw_snd_nxt + 65535 + 2; |
170 | |
171 | if (!seq) |
172 | seq = 1; |
173 | WRITE_ONCE(tp->write_seq, seq); |
174 | tp->rx_opt.ts_recent = tcptw->tw_ts_recent; |
175 | tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; |
176 | } |
177 | sock_hold(sk: sktw); |
178 | return 1; |
179 | } |
180 | |
181 | return 0; |
182 | } |
183 | EXPORT_SYMBOL_GPL(tcp_twsk_unique); |
184 | |
185 | static int tcp_v4_pre_connect(struct sock *sk, struct sockaddr *uaddr, |
186 | int addr_len) |
187 | { |
188 | /* This check is replicated from tcp_v4_connect() and intended to |
189 | * prevent BPF program called below from accessing bytes that are out |
190 | * of the bound specified by user in addr_len. |
191 | */ |
192 | if (addr_len < sizeof(struct sockaddr_in)) |
193 | return -EINVAL; |
194 | |
195 | sock_owned_by_me(sk); |
196 | |
197 | return BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr, &addr_len); |
198 | } |
199 | |
200 | /* This will initiate an outgoing connection. */ |
201 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) |
202 | { |
203 | struct sockaddr_in *usin = (struct sockaddr_in *)uaddr; |
204 | struct inet_timewait_death_row *tcp_death_row; |
205 | struct inet_sock *inet = inet_sk(sk); |
206 | struct tcp_sock *tp = tcp_sk(sk); |
207 | struct ip_options_rcu *inet_opt; |
208 | struct net *net = sock_net(sk); |
209 | __be16 orig_sport, orig_dport; |
210 | __be32 daddr, nexthop; |
211 | struct flowi4 *fl4; |
212 | struct rtable *rt; |
213 | int err; |
214 | |
215 | if (addr_len < sizeof(struct sockaddr_in)) |
216 | return -EINVAL; |
217 | |
218 | if (usin->sin_family != AF_INET) |
219 | return -EAFNOSUPPORT; |
220 | |
221 | nexthop = daddr = usin->sin_addr.s_addr; |
222 | inet_opt = rcu_dereference_protected(inet->inet_opt, |
223 | lockdep_sock_is_held(sk)); |
224 | if (inet_opt && inet_opt->opt.srr) { |
225 | if (!daddr) |
226 | return -EINVAL; |
227 | nexthop = inet_opt->opt.faddr; |
228 | } |
229 | |
230 | orig_sport = inet->inet_sport; |
231 | orig_dport = usin->sin_port; |
232 | fl4 = &inet->cork.fl.u.ip4; |
233 | rt = ip_route_connect(fl4, dst: nexthop, src: inet->inet_saddr, |
234 | oif: sk->sk_bound_dev_if, IPPROTO_TCP, sport: orig_sport, |
235 | dport: orig_dport, sk); |
236 | if (IS_ERR(ptr: rt)) { |
237 | err = PTR_ERR(ptr: rt); |
238 | if (err == -ENETUNREACH) |
239 | IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); |
240 | return err; |
241 | } |
242 | |
243 | if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { |
244 | ip_rt_put(rt); |
245 | return -ENETUNREACH; |
246 | } |
247 | |
248 | if (!inet_opt || !inet_opt->opt.srr) |
249 | daddr = fl4->daddr; |
250 | |
251 | tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; |
252 | |
253 | if (!inet->inet_saddr) { |
254 | err = inet_bhash2_update_saddr(sk, saddr: &fl4->saddr, AF_INET); |
255 | if (err) { |
256 | ip_rt_put(rt); |
257 | return err; |
258 | } |
259 | } else { |
260 | sk_rcv_saddr_set(sk, addr: inet->inet_saddr); |
261 | } |
262 | |
263 | if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) { |
264 | /* Reset inherited state */ |
265 | tp->rx_opt.ts_recent = 0; |
266 | tp->rx_opt.ts_recent_stamp = 0; |
267 | if (likely(!tp->repair)) |
268 | WRITE_ONCE(tp->write_seq, 0); |
269 | } |
270 | |
271 | inet->inet_dport = usin->sin_port; |
272 | sk_daddr_set(sk, addr: daddr); |
273 | |
274 | inet_csk(sk)->icsk_ext_hdr_len = 0; |
275 | if (inet_opt) |
276 | inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen; |
277 | |
278 | tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT; |
279 | |
280 | /* Socket identity is still unknown (sport may be zero). |
281 | * However we set state to SYN-SENT and not releasing socket |
282 | * lock select source port, enter ourselves into the hash tables and |
283 | * complete initialization after this. |
284 | */ |
285 | tcp_set_state(sk, state: TCP_SYN_SENT); |
286 | err = inet_hash_connect(death_row: tcp_death_row, sk); |
287 | if (err) |
288 | goto failure; |
289 | |
290 | sk_set_txhash(sk); |
291 | |
292 | rt = ip_route_newports(fl4, rt, orig_sport, orig_dport, |
293 | sport: inet->inet_sport, dport: inet->inet_dport, sk); |
294 | if (IS_ERR(ptr: rt)) { |
295 | err = PTR_ERR(ptr: rt); |
296 | rt = NULL; |
297 | goto failure; |
298 | } |
299 | tp->tcp_usec_ts = dst_tcp_usec_ts(dst: &rt->dst); |
300 | /* OK, now commit destination to socket. */ |
301 | sk->sk_gso_type = SKB_GSO_TCPV4; |
302 | sk_setup_caps(sk, dst: &rt->dst); |
303 | rt = NULL; |
304 | |
305 | if (likely(!tp->repair)) { |
306 | if (!tp->write_seq) |
307 | WRITE_ONCE(tp->write_seq, |
308 | secure_tcp_seq(inet->inet_saddr, |
309 | inet->inet_daddr, |
310 | inet->inet_sport, |
311 | usin->sin_port)); |
312 | WRITE_ONCE(tp->tsoffset, |
313 | secure_tcp_ts_off(net, inet->inet_saddr, |
314 | inet->inet_daddr)); |
315 | } |
316 | |
317 | atomic_set(v: &inet->inet_id, i: get_random_u16()); |
318 | |
319 | if (tcp_fastopen_defer_connect(sk, err: &err)) |
320 | return err; |
321 | if (err) |
322 | goto failure; |
323 | |
324 | err = tcp_connect(sk); |
325 | |
326 | if (err) |
327 | goto failure; |
328 | |
329 | return 0; |
330 | |
331 | failure: |
332 | /* |
333 | * This unhashes the socket and releases the local port, |
334 | * if necessary. |
335 | */ |
336 | tcp_set_state(sk, state: TCP_CLOSE); |
337 | inet_bhash2_reset_saddr(sk); |
338 | ip_rt_put(rt); |
339 | sk->sk_route_caps = 0; |
340 | inet->inet_dport = 0; |
341 | return err; |
342 | } |
343 | EXPORT_SYMBOL(tcp_v4_connect); |
344 | |
345 | /* |
346 | * This routine reacts to ICMP_FRAG_NEEDED mtu indications as defined in RFC1191. |
347 | * It can be called through tcp_release_cb() if socket was owned by user |
348 | * at the time tcp_v4_err() was called to handle ICMP message. |
349 | */ |
350 | void tcp_v4_mtu_reduced(struct sock *sk) |
351 | { |
352 | struct inet_sock *inet = inet_sk(sk); |
353 | struct dst_entry *dst; |
354 | u32 mtu; |
355 | |
356 | if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) |
357 | return; |
358 | mtu = READ_ONCE(tcp_sk(sk)->mtu_info); |
359 | dst = inet_csk_update_pmtu(sk, mtu); |
360 | if (!dst) |
361 | return; |
362 | |
363 | /* Something is about to be wrong... Remember soft error |
364 | * for the case, if this connection will not able to recover. |
365 | */ |
366 | if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst)) |
367 | WRITE_ONCE(sk->sk_err_soft, EMSGSIZE); |
368 | |
369 | mtu = dst_mtu(dst); |
370 | |
371 | if (inet->pmtudisc != IP_PMTUDISC_DONT && |
372 | ip_sk_accept_pmtu(sk) && |
373 | inet_csk(sk)->icsk_pmtu_cookie > mtu) { |
374 | tcp_sync_mss(sk, pmtu: mtu); |
375 | |
376 | /* Resend the TCP packet because it's |
377 | * clear that the old packet has been |
378 | * dropped. This is the new "fast" path mtu |
379 | * discovery. |
380 | */ |
381 | tcp_simple_retransmit(sk); |
382 | } /* else let the usual retransmit timer handle it */ |
383 | } |
384 | EXPORT_SYMBOL(tcp_v4_mtu_reduced); |
385 | |
386 | static void do_redirect(struct sk_buff *skb, struct sock *sk) |
387 | { |
388 | struct dst_entry *dst = __sk_dst_check(sk, cookie: 0); |
389 | |
390 | if (dst) |
391 | dst->ops->redirect(dst, sk, skb); |
392 | } |
393 | |
394 | |
395 | /* handle ICMP messages on TCP_NEW_SYN_RECV request sockets */ |
396 | void tcp_req_err(struct sock *sk, u32 seq, bool abort) |
397 | { |
398 | struct request_sock *req = inet_reqsk(sk); |
399 | struct net *net = sock_net(sk); |
400 | |
401 | /* ICMPs are not backlogged, hence we cannot get |
402 | * an established socket here. |
403 | */ |
404 | if (seq != tcp_rsk(req)->snt_isn) { |
405 | __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); |
406 | } else if (abort) { |
407 | /* |
408 | * Still in SYN_RECV, just remove it silently. |
409 | * There is no good way to pass the error to the newly |
410 | * created socket, and POSIX does not want network |
411 | * errors returned from accept(). |
412 | */ |
413 | inet_csk_reqsk_queue_drop(sk: req->rsk_listener, req); |
414 | tcp_listendrop(sk: req->rsk_listener); |
415 | } |
416 | reqsk_put(req); |
417 | } |
418 | EXPORT_SYMBOL(tcp_req_err); |
419 | |
420 | /* TCP-LD (RFC 6069) logic */ |
421 | void tcp_ld_RTO_revert(struct sock *sk, u32 seq) |
422 | { |
423 | struct inet_connection_sock *icsk = inet_csk(sk); |
424 | struct tcp_sock *tp = tcp_sk(sk); |
425 | struct sk_buff *skb; |
426 | s32 remaining; |
427 | u32 delta_us; |
428 | |
429 | if (sock_owned_by_user(sk)) |
430 | return; |
431 | |
432 | if (seq != tp->snd_una || !icsk->icsk_retransmits || |
433 | !icsk->icsk_backoff) |
434 | return; |
435 | |
436 | skb = tcp_rtx_queue_head(sk); |
437 | if (WARN_ON_ONCE(!skb)) |
438 | return; |
439 | |
440 | icsk->icsk_backoff--; |
441 | icsk->icsk_rto = tp->srtt_us ? __tcp_set_rto(tp) : TCP_TIMEOUT_INIT; |
442 | icsk->icsk_rto = inet_csk_rto_backoff(icsk, TCP_RTO_MAX); |
443 | |
444 | tcp_mstamp_refresh(tp); |
445 | delta_us = (u32)(tp->tcp_mstamp - tcp_skb_timestamp_us(skb)); |
446 | remaining = icsk->icsk_rto - usecs_to_jiffies(u: delta_us); |
447 | |
448 | if (remaining > 0) { |
449 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
450 | when: remaining, TCP_RTO_MAX); |
451 | } else { |
452 | /* RTO revert clocked out retransmission. |
453 | * Will retransmit now. |
454 | */ |
455 | tcp_retransmit_timer(sk); |
456 | } |
457 | } |
458 | EXPORT_SYMBOL(tcp_ld_RTO_revert); |
459 | |
460 | /* |
461 | * This routine is called by the ICMP module when it gets some |
462 | * sort of error condition. If err < 0 then the socket should |
463 | * be closed and the error returned to the user. If err > 0 |
464 | * it's just the icmp type << 8 | icmp code. After adjustment |
465 | * header points to the first 8 bytes of the tcp header. We need |
466 | * to find the appropriate port. |
467 | * |
468 | * The locking strategy used here is very "optimistic". When |
469 | * someone else accesses the socket the ICMP is just dropped |
470 | * and for some paths there is no check at all. |
471 | * A more general error queue to queue errors for later handling |
472 | * is probably better. |
473 | * |
474 | */ |
475 | |
476 | int tcp_v4_err(struct sk_buff *skb, u32 info) |
477 | { |
478 | const struct iphdr *iph = (const struct iphdr *)skb->data; |
479 | struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2)); |
480 | struct tcp_sock *tp; |
481 | const int type = icmp_hdr(skb)->type; |
482 | const int code = icmp_hdr(skb)->code; |
483 | struct sock *sk; |
484 | struct request_sock *fastopen; |
485 | u32 seq, snd_una; |
486 | int err; |
487 | struct net *net = dev_net(dev: skb->dev); |
488 | |
489 | sk = __inet_lookup_established(net, hashinfo: net->ipv4.tcp_death_row.hashinfo, |
490 | saddr: iph->daddr, sport: th->dest, daddr: iph->saddr, |
491 | ntohs(th->source), dif: inet_iif(skb), sdif: 0); |
492 | if (!sk) { |
493 | __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); |
494 | return -ENOENT; |
495 | } |
496 | if (sk->sk_state == TCP_TIME_WAIT) { |
497 | /* To increase the counter of ignored icmps for TCP-AO */ |
498 | tcp_ao_ignore_icmp(sk, AF_INET, type, code); |
499 | inet_twsk_put(tw: inet_twsk(sk)); |
500 | return 0; |
501 | } |
502 | seq = ntohl(th->seq); |
503 | if (sk->sk_state == TCP_NEW_SYN_RECV) { |
504 | tcp_req_err(sk, seq, type == ICMP_PARAMETERPROB || |
505 | type == ICMP_TIME_EXCEEDED || |
506 | (type == ICMP_DEST_UNREACH && |
507 | (code == ICMP_NET_UNREACH || |
508 | code == ICMP_HOST_UNREACH))); |
509 | return 0; |
510 | } |
511 | |
512 | if (tcp_ao_ignore_icmp(sk, AF_INET, type, code)) { |
513 | sock_put(sk); |
514 | return 0; |
515 | } |
516 | |
517 | bh_lock_sock(sk); |
518 | /* If too many ICMPs get dropped on busy |
519 | * servers this needs to be solved differently. |
520 | * We do take care of PMTU discovery (RFC1191) special case : |
521 | * we can receive locally generated ICMP messages while socket is held. |
522 | */ |
523 | if (sock_owned_by_user(sk)) { |
524 | if (!(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)) |
525 | __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); |
526 | } |
527 | if (sk->sk_state == TCP_CLOSE) |
528 | goto out; |
529 | |
530 | if (static_branch_unlikely(&ip4_min_ttl)) { |
531 | /* min_ttl can be changed concurrently from do_ip_setsockopt() */ |
532 | if (unlikely(iph->ttl < READ_ONCE(inet_sk(sk)->min_ttl))) { |
533 | __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); |
534 | goto out; |
535 | } |
536 | } |
537 | |
538 | tp = tcp_sk(sk); |
539 | /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */ |
540 | fastopen = rcu_dereference(tp->fastopen_rsk); |
541 | snd_una = fastopen ? tcp_rsk(req: fastopen)->snt_isn : tp->snd_una; |
542 | if (sk->sk_state != TCP_LISTEN && |
543 | !between(seq1: seq, seq2: snd_una, seq3: tp->snd_nxt)) { |
544 | __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); |
545 | goto out; |
546 | } |
547 | |
548 | switch (type) { |
549 | case ICMP_REDIRECT: |
550 | if (!sock_owned_by_user(sk)) |
551 | do_redirect(skb, sk); |
552 | goto out; |
553 | case ICMP_SOURCE_QUENCH: |
554 | /* Just silently ignore these. */ |
555 | goto out; |
556 | case ICMP_PARAMETERPROB: |
557 | err = EPROTO; |
558 | break; |
559 | case ICMP_DEST_UNREACH: |
560 | if (code > NR_ICMP_UNREACH) |
561 | goto out; |
562 | |
563 | if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ |
564 | /* We are not interested in TCP_LISTEN and open_requests |
565 | * (SYN-ACKs send out by Linux are always <576bytes so |
566 | * they should go through unfragmented). |
567 | */ |
568 | if (sk->sk_state == TCP_LISTEN) |
569 | goto out; |
570 | |
571 | WRITE_ONCE(tp->mtu_info, info); |
572 | if (!sock_owned_by_user(sk)) { |
573 | tcp_v4_mtu_reduced(sk); |
574 | } else { |
575 | if (!test_and_set_bit(nr: TCP_MTU_REDUCED_DEFERRED, addr: &sk->sk_tsq_flags)) |
576 | sock_hold(sk); |
577 | } |
578 | goto out; |
579 | } |
580 | |
581 | err = icmp_err_convert[code].errno; |
582 | /* check if this ICMP message allows revert of backoff. |
583 | * (see RFC 6069) |
584 | */ |
585 | if (!fastopen && |
586 | (code == ICMP_NET_UNREACH || code == ICMP_HOST_UNREACH)) |
587 | tcp_ld_RTO_revert(sk, seq); |
588 | break; |
589 | case ICMP_TIME_EXCEEDED: |
590 | err = EHOSTUNREACH; |
591 | break; |
592 | default: |
593 | goto out; |
594 | } |
595 | |
596 | switch (sk->sk_state) { |
597 | case TCP_SYN_SENT: |
598 | case TCP_SYN_RECV: |
599 | /* Only in fast or simultaneous open. If a fast open socket is |
600 | * already accepted it is treated as a connected one below. |
601 | */ |
602 | if (fastopen && !fastopen->sk) |
603 | break; |
604 | |
605 | ip_icmp_error(sk, skb, err, port: th->dest, info, payload: (u8 *)th); |
606 | |
607 | if (!sock_owned_by_user(sk)) { |
608 | WRITE_ONCE(sk->sk_err, err); |
609 | |
610 | sk_error_report(sk); |
611 | |
612 | tcp_done(sk); |
613 | } else { |
614 | WRITE_ONCE(sk->sk_err_soft, err); |
615 | } |
616 | goto out; |
617 | } |
618 | |
619 | /* If we've already connected we will keep trying |
620 | * until we time out, or the user gives up. |
621 | * |
622 | * rfc1122 4.2.3.9 allows to consider as hard errors |
623 | * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, |
624 | * but it is obsoleted by pmtu discovery). |
625 | * |
626 | * Note, that in modern internet, where routing is unreliable |
627 | * and in each dark corner broken firewalls sit, sending random |
628 | * errors ordered by their masters even this two messages finally lose |
629 | * their original sense (even Linux sends invalid PORT_UNREACHs) |
630 | * |
631 | * Now we are in compliance with RFCs. |
632 | * --ANK (980905) |
633 | */ |
634 | |
635 | if (!sock_owned_by_user(sk) && |
636 | inet_test_bit(RECVERR, sk)) { |
637 | WRITE_ONCE(sk->sk_err, err); |
638 | sk_error_report(sk); |
639 | } else { /* Only an error on timeout */ |
640 | WRITE_ONCE(sk->sk_err_soft, err); |
641 | } |
642 | |
643 | out: |
644 | bh_unlock_sock(sk); |
645 | sock_put(sk); |
646 | return 0; |
647 | } |
648 | |
649 | void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr) |
650 | { |
651 | struct tcphdr *th = tcp_hdr(skb); |
652 | |
653 | th->check = ~tcp_v4_check(len: skb->len, saddr, daddr, base: 0); |
654 | skb->csum_start = skb_transport_header(skb) - skb->head; |
655 | skb->csum_offset = offsetof(struct tcphdr, check); |
656 | } |
657 | |
658 | /* This routine computes an IPv4 TCP checksum. */ |
659 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb) |
660 | { |
661 | const struct inet_sock *inet = inet_sk(sk); |
662 | |
663 | __tcp_v4_send_check(skb, saddr: inet->inet_saddr, daddr: inet->inet_daddr); |
664 | } |
665 | EXPORT_SYMBOL(tcp_v4_send_check); |
666 | |
667 | #define REPLY_OPTIONS_LEN (MAX_TCP_OPTION_SPACE / sizeof(__be32)) |
668 | |
669 | static bool tcp_v4_ao_sign_reset(const struct sock *sk, struct sk_buff *skb, |
670 | const struct tcp_ao_hdr *aoh, |
671 | struct ip_reply_arg *arg, struct tcphdr *reply, |
672 | __be32 reply_options[REPLY_OPTIONS_LEN]) |
673 | { |
674 | #ifdef CONFIG_TCP_AO |
675 | int sdif = tcp_v4_sdif(skb); |
676 | int dif = inet_iif(skb); |
677 | int l3index = sdif ? dif : 0; |
678 | bool allocated_traffic_key; |
679 | struct tcp_ao_key *key; |
680 | char *traffic_key; |
681 | bool drop = true; |
682 | u32 ao_sne = 0; |
683 | u8 keyid; |
684 | |
685 | rcu_read_lock(); |
686 | if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, ntohl(reply->seq), |
687 | key: &key, traffic_key: &traffic_key, allocated_traffic_key: &allocated_traffic_key, |
688 | keyid: &keyid, sne: &ao_sne)) |
689 | goto out; |
690 | |
691 | reply_options[0] = htonl((TCPOPT_AO << 24) | (tcp_ao_len(key) << 16) | |
692 | (aoh->rnext_keyid << 8) | keyid); |
693 | arg->iov[0].iov_len += round_up(tcp_ao_len(key), 4); |
694 | reply->doff = arg->iov[0].iov_len / 4; |
695 | |
696 | if (tcp_ao_hash_hdr(AF_INET, ao_hash: (char *)&reply_options[1], |
697 | key, tkey: traffic_key, |
698 | daddr: (union tcp_ao_addr *)&ip_hdr(skb)->saddr, |
699 | saddr: (union tcp_ao_addr *)&ip_hdr(skb)->daddr, |
700 | th: reply, sne: ao_sne)) |
701 | goto out; |
702 | drop = false; |
703 | out: |
704 | rcu_read_unlock(); |
705 | if (allocated_traffic_key) |
706 | kfree(objp: traffic_key); |
707 | return drop; |
708 | #else |
709 | return true; |
710 | #endif |
711 | } |
712 | |
713 | /* |
714 | * This routine will send an RST to the other tcp. |
715 | * |
716 | * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.) |
717 | * for reset. |
718 | * Answer: if a packet caused RST, it is not for a socket |
719 | * existing in our system, if it is matched to a socket, |
720 | * it is just duplicate segment or bug in other side's TCP. |
721 | * So that we build reply only basing on parameters |
722 | * arrived with segment. |
723 | * Exception: precedence violation. We do not implement it in any case. |
724 | */ |
725 | |
726 | static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) |
727 | { |
728 | const struct tcphdr *th = tcp_hdr(skb); |
729 | struct { |
730 | struct tcphdr th; |
731 | __be32 opt[REPLY_OPTIONS_LEN]; |
732 | } rep; |
733 | const __u8 *md5_hash_location = NULL; |
734 | const struct tcp_ao_hdr *aoh; |
735 | struct ip_reply_arg arg; |
736 | #ifdef CONFIG_TCP_MD5SIG |
737 | struct tcp_md5sig_key *key = NULL; |
738 | unsigned char newhash[16]; |
739 | struct sock *sk1 = NULL; |
740 | int genhash; |
741 | #endif |
742 | u64 transmit_time = 0; |
743 | struct sock *ctl_sk; |
744 | struct net *net; |
745 | u32 txhash = 0; |
746 | |
747 | /* Never send a reset in response to a reset. */ |
748 | if (th->rst) |
749 | return; |
750 | |
751 | /* If sk not NULL, it means we did a successful lookup and incoming |
752 | * route had to be correct. prequeue might have dropped our dst. |
753 | */ |
754 | if (!sk && skb_rtable(skb)->rt_type != RTN_LOCAL) |
755 | return; |
756 | |
757 | /* Swap the send and the receive. */ |
758 | memset(&rep, 0, sizeof(rep)); |
759 | rep.th.dest = th->source; |
760 | rep.th.source = th->dest; |
761 | rep.th.doff = sizeof(struct tcphdr) / 4; |
762 | rep.th.rst = 1; |
763 | |
764 | if (th->ack) { |
765 | rep.th.seq = th->ack_seq; |
766 | } else { |
767 | rep.th.ack = 1; |
768 | rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin + |
769 | skb->len - (th->doff << 2)); |
770 | } |
771 | |
772 | memset(&arg, 0, sizeof(arg)); |
773 | arg.iov[0].iov_base = (unsigned char *)&rep; |
774 | arg.iov[0].iov_len = sizeof(rep.th); |
775 | |
776 | net = sk ? sock_net(sk) : dev_net(dev: skb_dst(skb)->dev); |
777 | |
778 | /* Invalid TCP option size or twice included auth */ |
779 | if (tcp_parse_auth_options(th: tcp_hdr(skb), md5_hash: &md5_hash_location, aoh: &aoh)) |
780 | return; |
781 | |
782 | if (aoh && tcp_v4_ao_sign_reset(sk, skb, aoh, arg: &arg, reply: &rep.th, reply_options: rep.opt)) |
783 | return; |
784 | |
785 | #ifdef CONFIG_TCP_MD5SIG |
786 | rcu_read_lock(); |
787 | if (sk && sk_fullsock(sk)) { |
788 | const union tcp_md5_addr *addr; |
789 | int l3index; |
790 | |
791 | /* sdif set, means packet ingressed via a device |
792 | * in an L3 domain and inet_iif is set to it. |
793 | */ |
794 | l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; |
795 | addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; |
796 | key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); |
797 | } else if (md5_hash_location) { |
798 | const union tcp_md5_addr *addr; |
799 | int sdif = tcp_v4_sdif(skb); |
800 | int dif = inet_iif(skb); |
801 | int l3index; |
802 | |
803 | /* |
804 | * active side is lost. Try to find listening socket through |
805 | * source port, and then find md5 key through listening socket. |
806 | * we are not loose security here: |
807 | * Incoming packet is checked with md5 hash with finding key, |
808 | * no RST generated if md5 hash doesn't match. |
809 | */ |
810 | sk1 = __inet_lookup_listener(net, hashinfo: net->ipv4.tcp_death_row.hashinfo, |
811 | NULL, doff: 0, saddr: ip_hdr(skb)->saddr, |
812 | sport: th->source, daddr: ip_hdr(skb)->daddr, |
813 | ntohs(th->source), dif, sdif); |
814 | /* don't send rst if it can't find key */ |
815 | if (!sk1) |
816 | goto out; |
817 | |
818 | /* sdif set, means packet ingressed via a device |
819 | * in an L3 domain and dif is set to it. |
820 | */ |
821 | l3index = sdif ? dif : 0; |
822 | addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; |
823 | key = tcp_md5_do_lookup(sk: sk1, l3index, addr, AF_INET); |
824 | if (!key) |
825 | goto out; |
826 | |
827 | |
828 | genhash = tcp_v4_md5_hash_skb(md5_hash: newhash, key, NULL, skb); |
829 | if (genhash || memcmp(p: md5_hash_location, q: newhash, size: 16) != 0) |
830 | goto out; |
831 | |
832 | } |
833 | |
834 | if (key) { |
835 | rep.opt[0] = htonl((TCPOPT_NOP << 24) | |
836 | (TCPOPT_NOP << 16) | |
837 | (TCPOPT_MD5SIG << 8) | |
838 | TCPOLEN_MD5SIG); |
839 | /* Update length and the length the header thinks exists */ |
840 | arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; |
841 | rep.th.doff = arg.iov[0].iov_len / 4; |
842 | |
843 | tcp_v4_md5_hash_hdr(md5_hash: (__u8 *) &rep.opt[1], |
844 | key, daddr: ip_hdr(skb)->saddr, |
845 | saddr: ip_hdr(skb)->daddr, th: &rep.th); |
846 | } |
847 | #endif |
848 | /* Can't co-exist with TCPMD5, hence check rep.opt[0] */ |
849 | if (rep.opt[0] == 0) { |
850 | __be32 mrst = mptcp_reset_option(skb); |
851 | |
852 | if (mrst) { |
853 | rep.opt[0] = mrst; |
854 | arg.iov[0].iov_len += sizeof(mrst); |
855 | rep.th.doff = arg.iov[0].iov_len / 4; |
856 | } |
857 | } |
858 | |
859 | arg.csum = csum_tcpudp_nofold(saddr: ip_hdr(skb)->daddr, |
860 | daddr: ip_hdr(skb)->saddr, /* XXX */ |
861 | len: arg.iov[0].iov_len, IPPROTO_TCP, sum: 0); |
862 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; |
863 | arg.flags = (sk && inet_sk_transparent(sk)) ? IP_REPLY_ARG_NOSRCCHECK : 0; |
864 | |
865 | /* When socket is gone, all binding information is lost. |
866 | * routing might fail in this case. No choice here, if we choose to force |
867 | * input interface, we will misroute in case of asymmetric route. |
868 | */ |
869 | if (sk) { |
870 | arg.bound_dev_if = sk->sk_bound_dev_if; |
871 | if (sk_fullsock(sk)) |
872 | trace_tcp_send_reset(sk, skb); |
873 | } |
874 | |
875 | BUILD_BUG_ON(offsetof(struct sock, sk_bound_dev_if) != |
876 | offsetof(struct inet_timewait_sock, tw_bound_dev_if)); |
877 | |
878 | arg.tos = ip_hdr(skb)->tos; |
879 | arg.uid = sock_net_uid(net, sk: sk && sk_fullsock(sk) ? sk : NULL); |
880 | local_bh_disable(); |
881 | ctl_sk = this_cpu_read(ipv4_tcp_sk); |
882 | sock_net_set(sk: ctl_sk, net); |
883 | if (sk) { |
884 | ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ? |
885 | inet_twsk(sk)->tw_mark : sk->sk_mark; |
886 | ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ? |
887 | inet_twsk(sk)->tw_priority : READ_ONCE(sk->sk_priority); |
888 | transmit_time = tcp_transmit_time(sk); |
889 | xfrm_sk_clone_policy(sk: ctl_sk, osk: sk); |
890 | txhash = (sk->sk_state == TCP_TIME_WAIT) ? |
891 | inet_twsk(sk)->tw_txhash : sk->sk_txhash; |
892 | } else { |
893 | ctl_sk->sk_mark = 0; |
894 | ctl_sk->sk_priority = 0; |
895 | } |
896 | ip_send_unicast_reply(sk: ctl_sk, |
897 | skb, sopt: &TCP_SKB_CB(skb)->header.h4.opt, |
898 | daddr: ip_hdr(skb)->saddr, saddr: ip_hdr(skb)->daddr, |
899 | arg: &arg, len: arg.iov[0].iov_len, |
900 | transmit_time, txhash); |
901 | |
902 | xfrm_sk_free_policy(sk: ctl_sk); |
903 | sock_net_set(sk: ctl_sk, net: &init_net); |
904 | __TCP_INC_STATS(net, TCP_MIB_OUTSEGS); |
905 | __TCP_INC_STATS(net, TCP_MIB_OUTRSTS); |
906 | local_bh_enable(); |
907 | |
908 | #ifdef CONFIG_TCP_MD5SIG |
909 | out: |
910 | rcu_read_unlock(); |
911 | #endif |
912 | } |
913 | |
914 | /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states |
915 | outside socket context is ugly, certainly. What can I do? |
916 | */ |
917 | |
918 | static void tcp_v4_send_ack(const struct sock *sk, |
919 | struct sk_buff *skb, u32 seq, u32 ack, |
920 | u32 win, u32 tsval, u32 tsecr, int oif, |
921 | struct tcp_key *key, |
922 | int reply_flags, u8 tos, u32 txhash) |
923 | { |
924 | const struct tcphdr *th = tcp_hdr(skb); |
925 | struct { |
926 | struct tcphdr th; |
927 | __be32 opt[(MAX_TCP_OPTION_SPACE >> 2)]; |
928 | } rep; |
929 | struct net *net = sock_net(sk); |
930 | struct ip_reply_arg arg; |
931 | struct sock *ctl_sk; |
932 | u64 transmit_time; |
933 | |
934 | memset(&rep.th, 0, sizeof(struct tcphdr)); |
935 | memset(&arg, 0, sizeof(arg)); |
936 | |
937 | arg.iov[0].iov_base = (unsigned char *)&rep; |
938 | arg.iov[0].iov_len = sizeof(rep.th); |
939 | if (tsecr) { |
940 | rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
941 | (TCPOPT_TIMESTAMP << 8) | |
942 | TCPOLEN_TIMESTAMP); |
943 | rep.opt[1] = htonl(tsval); |
944 | rep.opt[2] = htonl(tsecr); |
945 | arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED; |
946 | } |
947 | |
948 | /* Swap the send and the receive. */ |
949 | rep.th.dest = th->source; |
950 | rep.th.source = th->dest; |
951 | rep.th.doff = arg.iov[0].iov_len / 4; |
952 | rep.th.seq = htonl(seq); |
953 | rep.th.ack_seq = htonl(ack); |
954 | rep.th.ack = 1; |
955 | rep.th.window = htons(win); |
956 | |
957 | #ifdef CONFIG_TCP_MD5SIG |
958 | if (tcp_key_is_md5(key)) { |
959 | int offset = (tsecr) ? 3 : 0; |
960 | |
961 | rep.opt[offset++] = htonl((TCPOPT_NOP << 24) | |
962 | (TCPOPT_NOP << 16) | |
963 | (TCPOPT_MD5SIG << 8) | |
964 | TCPOLEN_MD5SIG); |
965 | arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; |
966 | rep.th.doff = arg.iov[0].iov_len/4; |
967 | |
968 | tcp_v4_md5_hash_hdr(md5_hash: (__u8 *) &rep.opt[offset], |
969 | key: key->md5_key, daddr: ip_hdr(skb)->saddr, |
970 | saddr: ip_hdr(skb)->daddr, th: &rep.th); |
971 | } |
972 | #endif |
973 | #ifdef CONFIG_TCP_AO |
974 | if (tcp_key_is_ao(key)) { |
975 | int offset = (tsecr) ? 3 : 0; |
976 | |
977 | rep.opt[offset++] = htonl((TCPOPT_AO << 24) | |
978 | (tcp_ao_len(key->ao_key) << 16) | |
979 | (key->ao_key->sndid << 8) | |
980 | key->rcv_next); |
981 | arg.iov[0].iov_len += round_up(tcp_ao_len(key->ao_key), 4); |
982 | rep.th.doff = arg.iov[0].iov_len / 4; |
983 | |
984 | tcp_ao_hash_hdr(AF_INET, ao_hash: (char *)&rep.opt[offset], |
985 | key: key->ao_key, tkey: key->traffic_key, |
986 | daddr: (union tcp_ao_addr *)&ip_hdr(skb)->saddr, |
987 | saddr: (union tcp_ao_addr *)&ip_hdr(skb)->daddr, |
988 | th: &rep.th, sne: key->sne); |
989 | } |
990 | #endif |
991 | arg.flags = reply_flags; |
992 | arg.csum = csum_tcpudp_nofold(saddr: ip_hdr(skb)->daddr, |
993 | daddr: ip_hdr(skb)->saddr, /* XXX */ |
994 | len: arg.iov[0].iov_len, IPPROTO_TCP, sum: 0); |
995 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; |
996 | if (oif) |
997 | arg.bound_dev_if = oif; |
998 | arg.tos = tos; |
999 | arg.uid = sock_net_uid(net, sk: sk_fullsock(sk) ? sk : NULL); |
1000 | local_bh_disable(); |
1001 | ctl_sk = this_cpu_read(ipv4_tcp_sk); |
1002 | sock_net_set(sk: ctl_sk, net); |
1003 | ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ? |
1004 | inet_twsk(sk)->tw_mark : READ_ONCE(sk->sk_mark); |
1005 | ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ? |
1006 | inet_twsk(sk)->tw_priority : READ_ONCE(sk->sk_priority); |
1007 | transmit_time = tcp_transmit_time(sk); |
1008 | ip_send_unicast_reply(sk: ctl_sk, |
1009 | skb, sopt: &TCP_SKB_CB(skb)->header.h4.opt, |
1010 | daddr: ip_hdr(skb)->saddr, saddr: ip_hdr(skb)->daddr, |
1011 | arg: &arg, len: arg.iov[0].iov_len, |
1012 | transmit_time, txhash); |
1013 | |
1014 | sock_net_set(sk: ctl_sk, net: &init_net); |
1015 | __TCP_INC_STATS(net, TCP_MIB_OUTSEGS); |
1016 | local_bh_enable(); |
1017 | } |
1018 | |
1019 | static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) |
1020 | { |
1021 | struct inet_timewait_sock *tw = inet_twsk(sk); |
1022 | struct tcp_timewait_sock *tcptw = tcp_twsk(sk); |
1023 | struct tcp_key key = {}; |
1024 | #ifdef CONFIG_TCP_AO |
1025 | struct tcp_ao_info *ao_info; |
1026 | |
1027 | if (static_branch_unlikely(&tcp_ao_needed.key)) { |
1028 | /* FIXME: the segment to-be-acked is not verified yet */ |
1029 | ao_info = rcu_dereference(tcptw->ao_info); |
1030 | if (ao_info) { |
1031 | const struct tcp_ao_hdr *aoh; |
1032 | |
1033 | if (tcp_parse_auth_options(th: tcp_hdr(skb), NULL, aoh: &aoh)) { |
1034 | inet_twsk_put(tw); |
1035 | return; |
1036 | } |
1037 | |
1038 | if (aoh) |
1039 | key.ao_key = tcp_ao_established_key(ao: ao_info, sndid: aoh->rnext_keyid, rcvid: -1); |
1040 | } |
1041 | } |
1042 | if (key.ao_key) { |
1043 | struct tcp_ao_key *rnext_key; |
1044 | |
1045 | key.traffic_key = snd_other_key(key: key.ao_key); |
1046 | key.sne = READ_ONCE(ao_info->snd_sne); |
1047 | rnext_key = READ_ONCE(ao_info->rnext_key); |
1048 | key.rcv_next = rnext_key->rcvid; |
1049 | key.type = TCP_KEY_AO; |
1050 | #else |
1051 | if (0) { |
1052 | #endif |
1053 | #ifdef CONFIG_TCP_MD5SIG |
1054 | } else if (static_branch_unlikely(&tcp_md5_needed.key)) { |
1055 | key.md5_key = tcp_twsk_md5_key(tcptw); |
1056 | if (key.md5_key) |
1057 | key.type = TCP_KEY_MD5; |
1058 | #endif |
1059 | } |
1060 | |
1061 | tcp_v4_send_ack(sk, skb, |
1062 | seq: tcptw->tw_snd_nxt, ack: tcptw->tw_rcv_nxt, |
1063 | win: tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, |
1064 | tsval: tcp_tw_tsval(tcptw), |
1065 | tsecr: tcptw->tw_ts_recent, |
1066 | oif: tw->tw_bound_dev_if, key: &key, |
1067 | reply_flags: tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0, |
1068 | tos: tw->tw_tos, |
1069 | txhash: tw->tw_txhash); |
1070 | |
1071 | inet_twsk_put(tw); |
1072 | } |
1073 | |
1074 | static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, |
1075 | struct request_sock *req) |
1076 | { |
1077 | struct tcp_key key = {}; |
1078 | |
1079 | /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV |
1080 | * sk->sk_state == TCP_SYN_RECV -> for Fast Open. |
1081 | */ |
1082 | u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 : |
1083 | tcp_sk(sk)->snd_nxt; |
1084 | |
1085 | #ifdef CONFIG_TCP_AO |
1086 | if (static_branch_unlikely(&tcp_ao_needed.key) && |
1087 | tcp_rsk_used_ao(req)) { |
1088 | const union tcp_md5_addr *addr; |
1089 | const struct tcp_ao_hdr *aoh; |
1090 | int l3index; |
1091 | |
1092 | /* Invalid TCP option size or twice included auth */ |
1093 | if (tcp_parse_auth_options(th: tcp_hdr(skb), NULL, aoh: &aoh)) |
1094 | return; |
1095 | if (!aoh) |
1096 | return; |
1097 | |
1098 | addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; |
1099 | l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; |
1100 | key.ao_key = tcp_ao_do_lookup(sk, l3index, addr, AF_INET, |
1101 | sndid: aoh->rnext_keyid, rcvid: -1); |
1102 | if (unlikely(!key.ao_key)) { |
1103 | /* Send ACK with any matching MKT for the peer */ |
1104 | key.ao_key = tcp_ao_do_lookup(sk, l3index, addr, AF_INET, sndid: -1, rcvid: -1); |
1105 | /* Matching key disappeared (user removed the key?) |
1106 | * let the handshake timeout. |
1107 | */ |
1108 | if (!key.ao_key) { |
1109 | net_info_ratelimited("TCP-AO key for (%pI4, %d)->(%pI4, %d) suddenly disappeared, won't ACK new connection\n" , |
1110 | addr, |
1111 | ntohs(tcp_hdr(skb)->source), |
1112 | &ip_hdr(skb)->daddr, |
1113 | ntohs(tcp_hdr(skb)->dest)); |
1114 | return; |
1115 | } |
1116 | } |
1117 | key.traffic_key = kmalloc(size: tcp_ao_digest_size(key: key.ao_key), GFP_ATOMIC); |
1118 | if (!key.traffic_key) |
1119 | return; |
1120 | |
1121 | key.type = TCP_KEY_AO; |
1122 | key.rcv_next = aoh->keyid; |
1123 | tcp_v4_ao_calc_key_rsk(mkt: key.ao_key, key: key.traffic_key, req); |
1124 | #else |
1125 | if (0) { |
1126 | #endif |
1127 | #ifdef CONFIG_TCP_MD5SIG |
1128 | } else if (static_branch_unlikely(&tcp_md5_needed.key)) { |
1129 | const union tcp_md5_addr *addr; |
1130 | int l3index; |
1131 | |
1132 | addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; |
1133 | l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; |
1134 | key.md5_key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); |
1135 | if (key.md5_key) |
1136 | key.type = TCP_KEY_MD5; |
1137 | #endif |
1138 | } |
1139 | |
1140 | /* RFC 7323 2.3 |
1141 | * The window field (SEG.WND) of every outgoing segment, with the |
1142 | * exception of <SYN> segments, MUST be right-shifted by |
1143 | * Rcv.Wind.Shift bits: |
1144 | */ |
1145 | tcp_v4_send_ack(sk, skb, seq, |
1146 | ack: tcp_rsk(req)->rcv_nxt, |
1147 | win: req->rsk_rcv_wnd >> inet_rsk(sk: req)->rcv_wscale, |
1148 | tsval: tcp_rsk_tsval(treq: tcp_rsk(req)), |
1149 | READ_ONCE(req->ts_recent), |
1150 | oif: 0, key: &key, |
1151 | reply_flags: inet_rsk(sk: req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0, |
1152 | tos: ip_hdr(skb)->tos, |
1153 | READ_ONCE(tcp_rsk(req)->txhash)); |
1154 | if (tcp_key_is_ao(key: &key)) |
1155 | kfree(objp: key.traffic_key); |
1156 | } |
1157 | |
1158 | /* |
1159 | * Send a SYN-ACK after having received a SYN. |
1160 | * This still operates on a request_sock only, not on a big |
1161 | * socket. |
1162 | */ |
1163 | static int tcp_v4_send_synack(const struct sock *sk, struct dst_entry *dst, |
1164 | struct flowi *fl, |
1165 | struct request_sock *req, |
1166 | struct tcp_fastopen_cookie *foc, |
1167 | enum tcp_synack_type synack_type, |
1168 | struct sk_buff *syn_skb) |
1169 | { |
1170 | const struct inet_request_sock *ireq = inet_rsk(sk: req); |
1171 | struct flowi4 fl4; |
1172 | int err = -1; |
1173 | struct sk_buff *skb; |
1174 | u8 tos; |
1175 | |
1176 | /* First, grab a route. */ |
1177 | if (!dst && (dst = inet_csk_route_req(sk, fl4: &fl4, req)) == NULL) |
1178 | return -1; |
1179 | |
1180 | skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb); |
1181 | |
1182 | if (skb) { |
1183 | __tcp_v4_send_check(skb, saddr: ireq->ir_loc_addr, daddr: ireq->ir_rmt_addr); |
1184 | |
1185 | tos = READ_ONCE(inet_sk(sk)->tos); |
1186 | |
1187 | if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)) |
1188 | tos = (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) | |
1189 | (tos & INET_ECN_MASK); |
1190 | |
1191 | if (!INET_ECN_is_capable(dsfield: tos) && |
1192 | tcp_bpf_ca_needs_ecn(sk: (struct sock *)req)) |
1193 | tos |= INET_ECN_ECT_0; |
1194 | |
1195 | rcu_read_lock(); |
1196 | err = ip_build_and_send_pkt(skb, sk, saddr: ireq->ir_loc_addr, |
1197 | daddr: ireq->ir_rmt_addr, |
1198 | rcu_dereference(ireq->ireq_opt), |
1199 | tos); |
1200 | rcu_read_unlock(); |
1201 | err = net_xmit_eval(err); |
1202 | } |
1203 | |
1204 | return err; |
1205 | } |
1206 | |
1207 | /* |
1208 | * IPv4 request_sock destructor. |
1209 | */ |
1210 | static void tcp_v4_reqsk_destructor(struct request_sock *req) |
1211 | { |
1212 | kfree(rcu_dereference_protected(inet_rsk(req)->ireq_opt, 1)); |
1213 | } |
1214 | |
1215 | #ifdef CONFIG_TCP_MD5SIG |
1216 | /* |
1217 | * RFC2385 MD5 checksumming requires a mapping of |
1218 | * IP address->MD5 Key. |
1219 | * We need to maintain these in the sk structure. |
1220 | */ |
1221 | |
1222 | DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_md5_needed, HZ); |
1223 | EXPORT_SYMBOL(tcp_md5_needed); |
1224 | |
1225 | static bool better_md5_match(struct tcp_md5sig_key *old, struct tcp_md5sig_key *new) |
1226 | { |
1227 | if (!old) |
1228 | return true; |
1229 | |
1230 | /* l3index always overrides non-l3index */ |
1231 | if (old->l3index && new->l3index == 0) |
1232 | return false; |
1233 | if (old->l3index == 0 && new->l3index) |
1234 | return true; |
1235 | |
1236 | return old->prefixlen < new->prefixlen; |
1237 | } |
1238 | |
1239 | /* Find the Key structure for an address. */ |
1240 | struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, |
1241 | const union tcp_md5_addr *addr, |
1242 | int family, bool any_l3index) |
1243 | { |
1244 | const struct tcp_sock *tp = tcp_sk(sk); |
1245 | struct tcp_md5sig_key *key; |
1246 | const struct tcp_md5sig_info *md5sig; |
1247 | __be32 mask; |
1248 | struct tcp_md5sig_key *best_match = NULL; |
1249 | bool match; |
1250 | |
1251 | /* caller either holds rcu_read_lock() or socket lock */ |
1252 | md5sig = rcu_dereference_check(tp->md5sig_info, |
1253 | lockdep_sock_is_held(sk)); |
1254 | if (!md5sig) |
1255 | return NULL; |
1256 | |
1257 | hlist_for_each_entry_rcu(key, &md5sig->head, node, |
1258 | lockdep_sock_is_held(sk)) { |
1259 | if (key->family != family) |
1260 | continue; |
1261 | if (!any_l3index && key->flags & TCP_MD5SIG_FLAG_IFINDEX && |
1262 | key->l3index != l3index) |
1263 | continue; |
1264 | if (family == AF_INET) { |
1265 | mask = inet_make_mask(logmask: key->prefixlen); |
1266 | match = (key->addr.a4.s_addr & mask) == |
1267 | (addr->a4.s_addr & mask); |
1268 | #if IS_ENABLED(CONFIG_IPV6) |
1269 | } else if (family == AF_INET6) { |
1270 | match = ipv6_prefix_equal(addr1: &key->addr.a6, addr2: &addr->a6, |
1271 | prefixlen: key->prefixlen); |
1272 | #endif |
1273 | } else { |
1274 | match = false; |
1275 | } |
1276 | |
1277 | if (match && better_md5_match(old: best_match, new: key)) |
1278 | best_match = key; |
1279 | } |
1280 | return best_match; |
1281 | } |
1282 | EXPORT_SYMBOL(__tcp_md5_do_lookup); |
1283 | |
1284 | static struct tcp_md5sig_key *tcp_md5_do_lookup_exact(const struct sock *sk, |
1285 | const union tcp_md5_addr *addr, |
1286 | int family, u8 prefixlen, |
1287 | int l3index, u8 flags) |
1288 | { |
1289 | const struct tcp_sock *tp = tcp_sk(sk); |
1290 | struct tcp_md5sig_key *key; |
1291 | unsigned int size = sizeof(struct in_addr); |
1292 | const struct tcp_md5sig_info *md5sig; |
1293 | |
1294 | /* caller either holds rcu_read_lock() or socket lock */ |
1295 | md5sig = rcu_dereference_check(tp->md5sig_info, |
1296 | lockdep_sock_is_held(sk)); |
1297 | if (!md5sig) |
1298 | return NULL; |
1299 | #if IS_ENABLED(CONFIG_IPV6) |
1300 | if (family == AF_INET6) |
1301 | size = sizeof(struct in6_addr); |
1302 | #endif |
1303 | hlist_for_each_entry_rcu(key, &md5sig->head, node, |
1304 | lockdep_sock_is_held(sk)) { |
1305 | if (key->family != family) |
1306 | continue; |
1307 | if ((key->flags & TCP_MD5SIG_FLAG_IFINDEX) != (flags & TCP_MD5SIG_FLAG_IFINDEX)) |
1308 | continue; |
1309 | if (key->l3index != l3index) |
1310 | continue; |
1311 | if (!memcmp(p: &key->addr, q: addr, size) && |
1312 | key->prefixlen == prefixlen) |
1313 | return key; |
1314 | } |
1315 | return NULL; |
1316 | } |
1317 | |
1318 | struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, |
1319 | const struct sock *addr_sk) |
1320 | { |
1321 | const union tcp_md5_addr *addr; |
1322 | int l3index; |
1323 | |
1324 | l3index = l3mdev_master_ifindex_by_index(net: sock_net(sk), |
1325 | ifindex: addr_sk->sk_bound_dev_if); |
1326 | addr = (const union tcp_md5_addr *)&addr_sk->sk_daddr; |
1327 | return tcp_md5_do_lookup(sk, l3index, addr, AF_INET); |
1328 | } |
1329 | EXPORT_SYMBOL(tcp_v4_md5_lookup); |
1330 | |
1331 | static int tcp_md5sig_info_add(struct sock *sk, gfp_t gfp) |
1332 | { |
1333 | struct tcp_sock *tp = tcp_sk(sk); |
1334 | struct tcp_md5sig_info *md5sig; |
1335 | |
1336 | md5sig = kmalloc(size: sizeof(*md5sig), flags: gfp); |
1337 | if (!md5sig) |
1338 | return -ENOMEM; |
1339 | |
1340 | sk_gso_disable(sk); |
1341 | INIT_HLIST_HEAD(&md5sig->head); |
1342 | rcu_assign_pointer(tp->md5sig_info, md5sig); |
1343 | return 0; |
1344 | } |
1345 | |
1346 | /* This can be called on a newly created socket, from other files */ |
1347 | static int __tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
1348 | int family, u8 prefixlen, int l3index, u8 flags, |
1349 | const u8 *newkey, u8 newkeylen, gfp_t gfp) |
1350 | { |
1351 | /* Add Key to the list */ |
1352 | struct tcp_md5sig_key *key; |
1353 | struct tcp_sock *tp = tcp_sk(sk); |
1354 | struct tcp_md5sig_info *md5sig; |
1355 | |
1356 | key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen, l3index, flags); |
1357 | if (key) { |
1358 | /* Pre-existing entry - just update that one. |
1359 | * Note that the key might be used concurrently. |
1360 | * data_race() is telling kcsan that we do not care of |
1361 | * key mismatches, since changing MD5 key on live flows |
1362 | * can lead to packet drops. |
1363 | */ |
1364 | data_race(memcpy(key->key, newkey, newkeylen)); |
1365 | |
1366 | /* Pairs with READ_ONCE() in tcp_md5_hash_key(). |
1367 | * Also note that a reader could catch new key->keylen value |
1368 | * but old key->key[], this is the reason we use __GFP_ZERO |
1369 | * at sock_kmalloc() time below these lines. |
1370 | */ |
1371 | WRITE_ONCE(key->keylen, newkeylen); |
1372 | |
1373 | return 0; |
1374 | } |
1375 | |
1376 | md5sig = rcu_dereference_protected(tp->md5sig_info, |
1377 | lockdep_sock_is_held(sk)); |
1378 | |
1379 | key = sock_kmalloc(sk, size: sizeof(*key), priority: gfp | __GFP_ZERO); |
1380 | if (!key) |
1381 | return -ENOMEM; |
1382 | |
1383 | memcpy(key->key, newkey, newkeylen); |
1384 | key->keylen = newkeylen; |
1385 | key->family = family; |
1386 | key->prefixlen = prefixlen; |
1387 | key->l3index = l3index; |
1388 | key->flags = flags; |
1389 | memcpy(&key->addr, addr, |
1390 | (IS_ENABLED(CONFIG_IPV6) && family == AF_INET6) ? sizeof(struct in6_addr) : |
1391 | sizeof(struct in_addr)); |
1392 | hlist_add_head_rcu(n: &key->node, h: &md5sig->head); |
1393 | return 0; |
1394 | } |
1395 | |
1396 | int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
1397 | int family, u8 prefixlen, int l3index, u8 flags, |
1398 | const u8 *newkey, u8 newkeylen) |
1399 | { |
1400 | struct tcp_sock *tp = tcp_sk(sk); |
1401 | |
1402 | if (!rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk))) { |
1403 | if (tcp_md5_alloc_sigpool()) |
1404 | return -ENOMEM; |
1405 | |
1406 | if (tcp_md5sig_info_add(sk, GFP_KERNEL)) { |
1407 | tcp_md5_release_sigpool(); |
1408 | return -ENOMEM; |
1409 | } |
1410 | |
1411 | if (!static_branch_inc(&tcp_md5_needed.key)) { |
1412 | struct tcp_md5sig_info *md5sig; |
1413 | |
1414 | md5sig = rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk)); |
1415 | rcu_assign_pointer(tp->md5sig_info, NULL); |
1416 | kfree_rcu(md5sig, rcu); |
1417 | tcp_md5_release_sigpool(); |
1418 | return -EUSERS; |
1419 | } |
1420 | } |
1421 | |
1422 | return __tcp_md5_do_add(sk, addr, family, prefixlen, l3index, flags, |
1423 | newkey, newkeylen, GFP_KERNEL); |
1424 | } |
1425 | EXPORT_SYMBOL(tcp_md5_do_add); |
1426 | |
1427 | int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr, |
1428 | int family, u8 prefixlen, int l3index, |
1429 | struct tcp_md5sig_key *key) |
1430 | { |
1431 | struct tcp_sock *tp = tcp_sk(sk); |
1432 | |
1433 | if (!rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk))) { |
1434 | tcp_md5_add_sigpool(); |
1435 | |
1436 | if (tcp_md5sig_info_add(sk, gfp: sk_gfp_mask(sk, GFP_ATOMIC))) { |
1437 | tcp_md5_release_sigpool(); |
1438 | return -ENOMEM; |
1439 | } |
1440 | |
1441 | if (!static_key_fast_inc_not_disabled(key: &tcp_md5_needed.key.key)) { |
1442 | struct tcp_md5sig_info *md5sig; |
1443 | |
1444 | md5sig = rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk)); |
1445 | net_warn_ratelimited("Too many TCP-MD5 keys in the system\n" ); |
1446 | rcu_assign_pointer(tp->md5sig_info, NULL); |
1447 | kfree_rcu(md5sig, rcu); |
1448 | tcp_md5_release_sigpool(); |
1449 | return -EUSERS; |
1450 | } |
1451 | } |
1452 | |
1453 | return __tcp_md5_do_add(sk, addr, family, prefixlen, l3index, |
1454 | flags: key->flags, newkey: key->key, newkeylen: key->keylen, |
1455 | gfp: sk_gfp_mask(sk, GFP_ATOMIC)); |
1456 | } |
1457 | EXPORT_SYMBOL(tcp_md5_key_copy); |
1458 | |
1459 | int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family, |
1460 | u8 prefixlen, int l3index, u8 flags) |
1461 | { |
1462 | struct tcp_md5sig_key *key; |
1463 | |
1464 | key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen, l3index, flags); |
1465 | if (!key) |
1466 | return -ENOENT; |
1467 | hlist_del_rcu(n: &key->node); |
1468 | atomic_sub(i: sizeof(*key), v: &sk->sk_omem_alloc); |
1469 | kfree_rcu(key, rcu); |
1470 | return 0; |
1471 | } |
1472 | EXPORT_SYMBOL(tcp_md5_do_del); |
1473 | |
1474 | void tcp_clear_md5_list(struct sock *sk) |
1475 | { |
1476 | struct tcp_sock *tp = tcp_sk(sk); |
1477 | struct tcp_md5sig_key *key; |
1478 | struct hlist_node *n; |
1479 | struct tcp_md5sig_info *md5sig; |
1480 | |
1481 | md5sig = rcu_dereference_protected(tp->md5sig_info, 1); |
1482 | |
1483 | hlist_for_each_entry_safe(key, n, &md5sig->head, node) { |
1484 | hlist_del_rcu(n: &key->node); |
1485 | atomic_sub(i: sizeof(*key), v: &sk->sk_omem_alloc); |
1486 | kfree_rcu(key, rcu); |
1487 | } |
1488 | } |
1489 | |
1490 | static int tcp_v4_parse_md5_keys(struct sock *sk, int optname, |
1491 | sockptr_t optval, int optlen) |
1492 | { |
1493 | struct tcp_md5sig cmd; |
1494 | struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr; |
1495 | const union tcp_md5_addr *addr; |
1496 | u8 prefixlen = 32; |
1497 | int l3index = 0; |
1498 | bool l3flag; |
1499 | u8 flags; |
1500 | |
1501 | if (optlen < sizeof(cmd)) |
1502 | return -EINVAL; |
1503 | |
1504 | if (copy_from_sockptr(dst: &cmd, src: optval, size: sizeof(cmd))) |
1505 | return -EFAULT; |
1506 | |
1507 | if (sin->sin_family != AF_INET) |
1508 | return -EINVAL; |
1509 | |
1510 | flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX; |
1511 | l3flag = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX; |
1512 | |
1513 | if (optname == TCP_MD5SIG_EXT && |
1514 | cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) { |
1515 | prefixlen = cmd.tcpm_prefixlen; |
1516 | if (prefixlen > 32) |
1517 | return -EINVAL; |
1518 | } |
1519 | |
1520 | if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex && |
1521 | cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) { |
1522 | struct net_device *dev; |
1523 | |
1524 | rcu_read_lock(); |
1525 | dev = dev_get_by_index_rcu(net: sock_net(sk), ifindex: cmd.tcpm_ifindex); |
1526 | if (dev && netif_is_l3_master(dev)) |
1527 | l3index = dev->ifindex; |
1528 | |
1529 | rcu_read_unlock(); |
1530 | |
1531 | /* ok to reference set/not set outside of rcu; |
1532 | * right now device MUST be an L3 master |
1533 | */ |
1534 | if (!dev || !l3index) |
1535 | return -EINVAL; |
1536 | } |
1537 | |
1538 | addr = (union tcp_md5_addr *)&sin->sin_addr.s_addr; |
1539 | |
1540 | if (!cmd.tcpm_keylen) |
1541 | return tcp_md5_do_del(sk, addr, AF_INET, prefixlen, l3index, flags); |
1542 | |
1543 | if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) |
1544 | return -EINVAL; |
1545 | |
1546 | /* Don't allow keys for peers that have a matching TCP-AO key. |
1547 | * See the comment in tcp_ao_add_cmd() |
1548 | */ |
1549 | if (tcp_ao_required(sk, saddr: addr, AF_INET, l3index: l3flag ? l3index : -1, stat_inc: false)) |
1550 | return -EKEYREJECTED; |
1551 | |
1552 | return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, flags, |
1553 | cmd.tcpm_key, cmd.tcpm_keylen); |
1554 | } |
1555 | |
1556 | static int (struct tcp_sigpool *hp, |
1557 | __be32 daddr, __be32 saddr, |
1558 | const struct tcphdr *th, int nbytes) |
1559 | { |
1560 | struct tcp4_pseudohdr *bp; |
1561 | struct scatterlist sg; |
1562 | struct tcphdr *_th; |
1563 | |
1564 | bp = hp->scratch; |
1565 | bp->saddr = saddr; |
1566 | bp->daddr = daddr; |
1567 | bp->pad = 0; |
1568 | bp->protocol = IPPROTO_TCP; |
1569 | bp->len = cpu_to_be16(nbytes); |
1570 | |
1571 | _th = (struct tcphdr *)(bp + 1); |
1572 | memcpy(_th, th, sizeof(*th)); |
1573 | _th->check = 0; |
1574 | |
1575 | sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th)); |
1576 | ahash_request_set_crypt(req: hp->req, src: &sg, NULL, |
1577 | nbytes: sizeof(*bp) + sizeof(*th)); |
1578 | return crypto_ahash_update(req: hp->req); |
1579 | } |
1580 | |
1581 | static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, |
1582 | __be32 daddr, __be32 saddr, const struct tcphdr *th) |
1583 | { |
1584 | struct tcp_sigpool hp; |
1585 | |
1586 | if (tcp_sigpool_start(id: tcp_md5_sigpool_id, c: &hp)) |
1587 | goto clear_hash_nostart; |
1588 | |
1589 | if (crypto_ahash_init(req: hp.req)) |
1590 | goto clear_hash; |
1591 | if (tcp_v4_md5_hash_headers(hp: &hp, daddr, saddr, th, nbytes: th->doff << 2)) |
1592 | goto clear_hash; |
1593 | if (tcp_md5_hash_key(hp: &hp, key)) |
1594 | goto clear_hash; |
1595 | ahash_request_set_crypt(req: hp.req, NULL, result: md5_hash, nbytes: 0); |
1596 | if (crypto_ahash_final(req: hp.req)) |
1597 | goto clear_hash; |
1598 | |
1599 | tcp_sigpool_end(c: &hp); |
1600 | return 0; |
1601 | |
1602 | clear_hash: |
1603 | tcp_sigpool_end(c: &hp); |
1604 | clear_hash_nostart: |
1605 | memset(md5_hash, 0, 16); |
1606 | return 1; |
1607 | } |
1608 | |
1609 | int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, |
1610 | const struct sock *sk, |
1611 | const struct sk_buff *skb) |
1612 | { |
1613 | const struct tcphdr *th = tcp_hdr(skb); |
1614 | struct tcp_sigpool hp; |
1615 | __be32 saddr, daddr; |
1616 | |
1617 | if (sk) { /* valid for establish/request sockets */ |
1618 | saddr = sk->sk_rcv_saddr; |
1619 | daddr = sk->sk_daddr; |
1620 | } else { |
1621 | const struct iphdr *iph = ip_hdr(skb); |
1622 | saddr = iph->saddr; |
1623 | daddr = iph->daddr; |
1624 | } |
1625 | |
1626 | if (tcp_sigpool_start(id: tcp_md5_sigpool_id, c: &hp)) |
1627 | goto clear_hash_nostart; |
1628 | |
1629 | if (crypto_ahash_init(req: hp.req)) |
1630 | goto clear_hash; |
1631 | |
1632 | if (tcp_v4_md5_hash_headers(hp: &hp, daddr, saddr, th, nbytes: skb->len)) |
1633 | goto clear_hash; |
1634 | if (tcp_sigpool_hash_skb_data(hp: &hp, skb, header_len: th->doff << 2)) |
1635 | goto clear_hash; |
1636 | if (tcp_md5_hash_key(hp: &hp, key)) |
1637 | goto clear_hash; |
1638 | ahash_request_set_crypt(req: hp.req, NULL, result: md5_hash, nbytes: 0); |
1639 | if (crypto_ahash_final(req: hp.req)) |
1640 | goto clear_hash; |
1641 | |
1642 | tcp_sigpool_end(c: &hp); |
1643 | return 0; |
1644 | |
1645 | clear_hash: |
1646 | tcp_sigpool_end(c: &hp); |
1647 | clear_hash_nostart: |
1648 | memset(md5_hash, 0, 16); |
1649 | return 1; |
1650 | } |
1651 | EXPORT_SYMBOL(tcp_v4_md5_hash_skb); |
1652 | |
1653 | #endif |
1654 | |
1655 | static void tcp_v4_init_req(struct request_sock *req, |
1656 | const struct sock *sk_listener, |
1657 | struct sk_buff *skb) |
1658 | { |
1659 | struct inet_request_sock *ireq = inet_rsk(sk: req); |
1660 | struct net *net = sock_net(sk: sk_listener); |
1661 | |
1662 | sk_rcv_saddr_set(sk: req_to_sk(req), addr: ip_hdr(skb)->daddr); |
1663 | sk_daddr_set(sk: req_to_sk(req), addr: ip_hdr(skb)->saddr); |
1664 | RCU_INIT_POINTER(ireq->ireq_opt, tcp_v4_save_options(net, skb)); |
1665 | } |
1666 | |
1667 | static struct dst_entry *tcp_v4_route_req(const struct sock *sk, |
1668 | struct sk_buff *skb, |
1669 | struct flowi *fl, |
1670 | struct request_sock *req) |
1671 | { |
1672 | tcp_v4_init_req(req, sk_listener: sk, skb); |
1673 | |
1674 | if (security_inet_conn_request(sk, skb, req)) |
1675 | return NULL; |
1676 | |
1677 | return inet_csk_route_req(sk, fl4: &fl->u.ip4, req); |
1678 | } |
1679 | |
1680 | struct request_sock_ops tcp_request_sock_ops __read_mostly = { |
1681 | .family = PF_INET, |
1682 | .obj_size = sizeof(struct tcp_request_sock), |
1683 | .rtx_syn_ack = tcp_rtx_synack, |
1684 | .send_ack = tcp_v4_reqsk_send_ack, |
1685 | .destructor = tcp_v4_reqsk_destructor, |
1686 | .send_reset = tcp_v4_send_reset, |
1687 | .syn_ack_timeout = tcp_syn_ack_timeout, |
1688 | }; |
1689 | |
1690 | const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = { |
1691 | .mss_clamp = TCP_MSS_DEFAULT, |
1692 | #ifdef CONFIG_TCP_MD5SIG |
1693 | .req_md5_lookup = tcp_v4_md5_lookup, |
1694 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
1695 | #endif |
1696 | #ifdef CONFIG_TCP_AO |
1697 | .ao_lookup = tcp_v4_ao_lookup_rsk, |
1698 | .ao_calc_key = tcp_v4_ao_calc_key_rsk, |
1699 | .ao_synack_hash = tcp_v4_ao_synack_hash, |
1700 | #endif |
1701 | #ifdef CONFIG_SYN_COOKIES |
1702 | .cookie_init_seq = cookie_v4_init_sequence, |
1703 | #endif |
1704 | .route_req = tcp_v4_route_req, |
1705 | .init_seq = tcp_v4_init_seq, |
1706 | .init_ts_off = tcp_v4_init_ts_off, |
1707 | .send_synack = tcp_v4_send_synack, |
1708 | }; |
1709 | |
1710 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) |
1711 | { |
1712 | /* Never answer to SYNs send to broadcast or multicast */ |
1713 | if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) |
1714 | goto drop; |
1715 | |
1716 | return tcp_conn_request(rsk_ops: &tcp_request_sock_ops, |
1717 | af_ops: &tcp_request_sock_ipv4_ops, sk, skb); |
1718 | |
1719 | drop: |
1720 | tcp_listendrop(sk); |
1721 | return 0; |
1722 | } |
1723 | EXPORT_SYMBOL(tcp_v4_conn_request); |
1724 | |
1725 | |
1726 | /* |
1727 | * The three way handshake has completed - we got a valid synack - |
1728 | * now create the new socket. |
1729 | */ |
1730 | struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, |
1731 | struct request_sock *req, |
1732 | struct dst_entry *dst, |
1733 | struct request_sock *req_unhash, |
1734 | bool *own_req) |
1735 | { |
1736 | struct inet_request_sock *ireq; |
1737 | bool found_dup_sk = false; |
1738 | struct inet_sock *newinet; |
1739 | struct tcp_sock *newtp; |
1740 | struct sock *newsk; |
1741 | #ifdef CONFIG_TCP_MD5SIG |
1742 | const union tcp_md5_addr *addr; |
1743 | struct tcp_md5sig_key *key; |
1744 | int l3index; |
1745 | #endif |
1746 | struct ip_options_rcu *inet_opt; |
1747 | |
1748 | if (sk_acceptq_is_full(sk)) |
1749 | goto exit_overflow; |
1750 | |
1751 | newsk = tcp_create_openreq_child(sk, req, skb); |
1752 | if (!newsk) |
1753 | goto exit_nonewsk; |
1754 | |
1755 | newsk->sk_gso_type = SKB_GSO_TCPV4; |
1756 | inet_sk_rx_dst_set(sk: newsk, skb); |
1757 | |
1758 | newtp = tcp_sk(newsk); |
1759 | newinet = inet_sk(newsk); |
1760 | ireq = inet_rsk(sk: req); |
1761 | sk_daddr_set(sk: newsk, addr: ireq->ir_rmt_addr); |
1762 | sk_rcv_saddr_set(sk: newsk, addr: ireq->ir_loc_addr); |
1763 | newsk->sk_bound_dev_if = ireq->ir_iif; |
1764 | newinet->inet_saddr = ireq->ir_loc_addr; |
1765 | inet_opt = rcu_dereference(ireq->ireq_opt); |
1766 | RCU_INIT_POINTER(newinet->inet_opt, inet_opt); |
1767 | newinet->mc_index = inet_iif(skb); |
1768 | newinet->mc_ttl = ip_hdr(skb)->ttl; |
1769 | newinet->rcv_tos = ip_hdr(skb)->tos; |
1770 | inet_csk(sk: newsk)->icsk_ext_hdr_len = 0; |
1771 | if (inet_opt) |
1772 | inet_csk(sk: newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen; |
1773 | atomic_set(v: &newinet->inet_id, i: get_random_u16()); |
1774 | |
1775 | /* Set ToS of the new socket based upon the value of incoming SYN. |
1776 | * ECT bits are set later in tcp_init_transfer(). |
1777 | */ |
1778 | if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)) |
1779 | newinet->tos = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK; |
1780 | |
1781 | if (!dst) { |
1782 | dst = inet_csk_route_child_sock(sk, newsk, req); |
1783 | if (!dst) |
1784 | goto put_and_exit; |
1785 | } else { |
1786 | /* syncookie case : see end of cookie_v4_check() */ |
1787 | } |
1788 | sk_setup_caps(sk: newsk, dst); |
1789 | |
1790 | tcp_ca_openreq_child(sk: newsk, dst); |
1791 | |
1792 | tcp_sync_mss(sk: newsk, pmtu: dst_mtu(dst)); |
1793 | newtp->advmss = tcp_mss_clamp(tcp_sk(sk), mss: dst_metric_advmss(dst)); |
1794 | |
1795 | tcp_initialize_rcv_mss(sk: newsk); |
1796 | |
1797 | #ifdef CONFIG_TCP_MD5SIG |
1798 | l3index = l3mdev_master_ifindex_by_index(net: sock_net(sk), ifindex: ireq->ir_iif); |
1799 | /* Copy over the MD5 key from the original socket */ |
1800 | addr = (union tcp_md5_addr *)&newinet->inet_daddr; |
1801 | key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); |
1802 | if (key && !tcp_rsk_used_ao(req)) { |
1803 | if (tcp_md5_key_copy(newsk, addr, AF_INET, 32, l3index, key)) |
1804 | goto put_and_exit; |
1805 | sk_gso_disable(sk: newsk); |
1806 | } |
1807 | #endif |
1808 | #ifdef CONFIG_TCP_AO |
1809 | if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET)) |
1810 | goto put_and_exit; /* OOM, release back memory */ |
1811 | #endif |
1812 | |
1813 | if (__inet_inherit_port(sk, child: newsk) < 0) |
1814 | goto put_and_exit; |
1815 | *own_req = inet_ehash_nolisten(sk: newsk, osk: req_to_sk(req: req_unhash), |
1816 | found_dup_sk: &found_dup_sk); |
1817 | if (likely(*own_req)) { |
1818 | tcp_move_syn(tp: newtp, req); |
1819 | ireq->ireq_opt = NULL; |
1820 | } else { |
1821 | newinet->inet_opt = NULL; |
1822 | |
1823 | if (!req_unhash && found_dup_sk) { |
1824 | /* This code path should only be executed in the |
1825 | * syncookie case only |
1826 | */ |
1827 | bh_unlock_sock(newsk); |
1828 | sock_put(sk: newsk); |
1829 | newsk = NULL; |
1830 | } |
1831 | } |
1832 | return newsk; |
1833 | |
1834 | exit_overflow: |
1835 | NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); |
1836 | exit_nonewsk: |
1837 | dst_release(dst); |
1838 | exit: |
1839 | tcp_listendrop(sk); |
1840 | return NULL; |
1841 | put_and_exit: |
1842 | newinet->inet_opt = NULL; |
1843 | inet_csk_prepare_forced_close(sk: newsk); |
1844 | tcp_done(sk: newsk); |
1845 | goto exit; |
1846 | } |
1847 | EXPORT_SYMBOL(tcp_v4_syn_recv_sock); |
1848 | |
1849 | static struct sock *tcp_v4_cookie_check(struct sock *sk, struct sk_buff *skb) |
1850 | { |
1851 | #ifdef CONFIG_SYN_COOKIES |
1852 | const struct tcphdr *th = tcp_hdr(skb); |
1853 | |
1854 | if (!th->syn) |
1855 | sk = cookie_v4_check(sk, skb); |
1856 | #endif |
1857 | return sk; |
1858 | } |
1859 | |
1860 | u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph, |
1861 | struct tcphdr *th, u32 *cookie) |
1862 | { |
1863 | u16 mss = 0; |
1864 | #ifdef CONFIG_SYN_COOKIES |
1865 | mss = tcp_get_syncookie_mss(rsk_ops: &tcp_request_sock_ops, |
1866 | af_ops: &tcp_request_sock_ipv4_ops, sk, th); |
1867 | if (mss) { |
1868 | *cookie = __cookie_v4_init_sequence(iph, th, mssp: &mss); |
1869 | tcp_synq_overflow(sk); |
1870 | } |
1871 | #endif |
1872 | return mss; |
1873 | } |
1874 | |
1875 | INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *, |
1876 | u32)); |
1877 | /* The socket must have it's spinlock held when we get |
1878 | * here, unless it is a TCP_LISTEN socket. |
1879 | * |
1880 | * We have a potential double-lock case here, so even when |
1881 | * doing backlog processing we use the BH locking scheme. |
1882 | * This is because we cannot sleep with the original spinlock |
1883 | * held. |
1884 | */ |
1885 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) |
1886 | { |
1887 | enum skb_drop_reason reason; |
1888 | struct sock *rsk; |
1889 | |
1890 | if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ |
1891 | struct dst_entry *dst; |
1892 | |
1893 | dst = rcu_dereference_protected(sk->sk_rx_dst, |
1894 | lockdep_sock_is_held(sk)); |
1895 | |
1896 | sock_rps_save_rxhash(sk, skb); |
1897 | sk_mark_napi_id(sk, skb); |
1898 | if (dst) { |
1899 | if (sk->sk_rx_dst_ifindex != skb->skb_iif || |
1900 | !INDIRECT_CALL_1(dst->ops->check, ipv4_dst_check, |
1901 | dst, 0)) { |
1902 | RCU_INIT_POINTER(sk->sk_rx_dst, NULL); |
1903 | dst_release(dst); |
1904 | } |
1905 | } |
1906 | tcp_rcv_established(sk, skb); |
1907 | return 0; |
1908 | } |
1909 | |
1910 | reason = SKB_DROP_REASON_NOT_SPECIFIED; |
1911 | if (tcp_checksum_complete(skb)) |
1912 | goto csum_err; |
1913 | |
1914 | if (sk->sk_state == TCP_LISTEN) { |
1915 | struct sock *nsk = tcp_v4_cookie_check(sk, skb); |
1916 | |
1917 | if (!nsk) |
1918 | goto discard; |
1919 | if (nsk != sk) { |
1920 | if (tcp_child_process(parent: sk, child: nsk, skb)) { |
1921 | rsk = nsk; |
1922 | goto reset; |
1923 | } |
1924 | return 0; |
1925 | } |
1926 | } else |
1927 | sock_rps_save_rxhash(sk, skb); |
1928 | |
1929 | if (tcp_rcv_state_process(sk, skb)) { |
1930 | rsk = sk; |
1931 | goto reset; |
1932 | } |
1933 | return 0; |
1934 | |
1935 | reset: |
1936 | tcp_v4_send_reset(sk: rsk, skb); |
1937 | discard: |
1938 | kfree_skb_reason(skb, reason); |
1939 | /* Be careful here. If this function gets more complicated and |
1940 | * gcc suffers from register pressure on the x86, sk (in %ebx) |
1941 | * might be destroyed here. This current version compiles correctly, |
1942 | * but you have been warned. |
1943 | */ |
1944 | return 0; |
1945 | |
1946 | csum_err: |
1947 | reason = SKB_DROP_REASON_TCP_CSUM; |
1948 | trace_tcp_bad_csum(skb); |
1949 | TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); |
1950 | TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); |
1951 | goto discard; |
1952 | } |
1953 | EXPORT_SYMBOL(tcp_v4_do_rcv); |
1954 | |
1955 | int tcp_v4_early_demux(struct sk_buff *skb) |
1956 | { |
1957 | struct net *net = dev_net(dev: skb->dev); |
1958 | const struct iphdr *iph; |
1959 | const struct tcphdr *th; |
1960 | struct sock *sk; |
1961 | |
1962 | if (skb->pkt_type != PACKET_HOST) |
1963 | return 0; |
1964 | |
1965 | if (!pskb_may_pull(skb, len: skb_transport_offset(skb) + sizeof(struct tcphdr))) |
1966 | return 0; |
1967 | |
1968 | iph = ip_hdr(skb); |
1969 | th = tcp_hdr(skb); |
1970 | |
1971 | if (th->doff < sizeof(struct tcphdr) / 4) |
1972 | return 0; |
1973 | |
1974 | sk = __inet_lookup_established(net, hashinfo: net->ipv4.tcp_death_row.hashinfo, |
1975 | saddr: iph->saddr, sport: th->source, |
1976 | daddr: iph->daddr, ntohs(th->dest), |
1977 | dif: skb->skb_iif, sdif: inet_sdif(skb)); |
1978 | if (sk) { |
1979 | skb->sk = sk; |
1980 | skb->destructor = sock_edemux; |
1981 | if (sk_fullsock(sk)) { |
1982 | struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst); |
1983 | |
1984 | if (dst) |
1985 | dst = dst_check(dst, cookie: 0); |
1986 | if (dst && |
1987 | sk->sk_rx_dst_ifindex == skb->skb_iif) |
1988 | skb_dst_set_noref(skb, dst); |
1989 | } |
1990 | } |
1991 | return 0; |
1992 | } |
1993 | |
1994 | bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb, |
1995 | enum skb_drop_reason *reason) |
1996 | { |
1997 | u32 limit, tail_gso_size, tail_gso_segs; |
1998 | struct skb_shared_info *shinfo; |
1999 | const struct tcphdr *th; |
2000 | struct tcphdr *thtail; |
2001 | struct sk_buff *tail; |
2002 | unsigned int hdrlen; |
2003 | bool fragstolen; |
2004 | u32 gso_segs; |
2005 | u32 gso_size; |
2006 | int delta; |
2007 | |
2008 | /* In case all data was pulled from skb frags (in __pskb_pull_tail()), |
2009 | * we can fix skb->truesize to its real value to avoid future drops. |
2010 | * This is valid because skb is not yet charged to the socket. |
2011 | * It has been noticed pure SACK packets were sometimes dropped |
2012 | * (if cooked by drivers without copybreak feature). |
2013 | */ |
2014 | skb_condense(skb); |
2015 | |
2016 | skb_dst_drop(skb); |
2017 | |
2018 | if (unlikely(tcp_checksum_complete(skb))) { |
2019 | bh_unlock_sock(sk); |
2020 | trace_tcp_bad_csum(skb); |
2021 | *reason = SKB_DROP_REASON_TCP_CSUM; |
2022 | __TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); |
2023 | __TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); |
2024 | return true; |
2025 | } |
2026 | |
2027 | /* Attempt coalescing to last skb in backlog, even if we are |
2028 | * above the limits. |
2029 | * This is okay because skb capacity is limited to MAX_SKB_FRAGS. |
2030 | */ |
2031 | th = (const struct tcphdr *)skb->data; |
2032 | hdrlen = th->doff * 4; |
2033 | |
2034 | tail = sk->sk_backlog.tail; |
2035 | if (!tail) |
2036 | goto no_coalesce; |
2037 | thtail = (struct tcphdr *)tail->data; |
2038 | |
2039 | if (TCP_SKB_CB(tail)->end_seq != TCP_SKB_CB(skb)->seq || |
2040 | TCP_SKB_CB(tail)->ip_dsfield != TCP_SKB_CB(skb)->ip_dsfield || |
2041 | ((TCP_SKB_CB(tail)->tcp_flags | |
2042 | TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_SYN | TCPHDR_RST | TCPHDR_URG)) || |
2043 | !((TCP_SKB_CB(tail)->tcp_flags & |
2044 | TCP_SKB_CB(skb)->tcp_flags) & TCPHDR_ACK) || |
2045 | ((TCP_SKB_CB(tail)->tcp_flags ^ |
2046 | TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_ECE | TCPHDR_CWR)) || |
2047 | #ifdef CONFIG_TLS_DEVICE |
2048 | tail->decrypted != skb->decrypted || |
2049 | #endif |
2050 | !mptcp_skb_can_collapse(to: tail, from: skb) || |
2051 | thtail->doff != th->doff || |
2052 | memcmp(p: thtail + 1, q: th + 1, size: hdrlen - sizeof(*th))) |
2053 | goto no_coalesce; |
2054 | |
2055 | __skb_pull(skb, len: hdrlen); |
2056 | |
2057 | shinfo = skb_shinfo(skb); |
2058 | gso_size = shinfo->gso_size ?: skb->len; |
2059 | gso_segs = shinfo->gso_segs ?: 1; |
2060 | |
2061 | shinfo = skb_shinfo(tail); |
2062 | tail_gso_size = shinfo->gso_size ?: (tail->len - hdrlen); |
2063 | tail_gso_segs = shinfo->gso_segs ?: 1; |
2064 | |
2065 | if (skb_try_coalesce(to: tail, from: skb, fragstolen: &fragstolen, delta_truesize: &delta)) { |
2066 | TCP_SKB_CB(tail)->end_seq = TCP_SKB_CB(skb)->end_seq; |
2067 | |
2068 | if (likely(!before(TCP_SKB_CB(skb)->ack_seq, TCP_SKB_CB(tail)->ack_seq))) { |
2069 | TCP_SKB_CB(tail)->ack_seq = TCP_SKB_CB(skb)->ack_seq; |
2070 | thtail->window = th->window; |
2071 | } |
2072 | |
2073 | /* We have to update both TCP_SKB_CB(tail)->tcp_flags and |
2074 | * thtail->fin, so that the fast path in tcp_rcv_established() |
2075 | * is not entered if we append a packet with a FIN. |
2076 | * SYN, RST, URG are not present. |
2077 | * ACK is set on both packets. |
2078 | * PSH : we do not really care in TCP stack, |
2079 | * at least for 'GRO' packets. |
2080 | */ |
2081 | thtail->fin |= th->fin; |
2082 | TCP_SKB_CB(tail)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags; |
2083 | |
2084 | if (TCP_SKB_CB(skb)->has_rxtstamp) { |
2085 | TCP_SKB_CB(tail)->has_rxtstamp = true; |
2086 | tail->tstamp = skb->tstamp; |
2087 | skb_hwtstamps(skb: tail)->hwtstamp = skb_hwtstamps(skb)->hwtstamp; |
2088 | } |
2089 | |
2090 | /* Not as strict as GRO. We only need to carry mss max value */ |
2091 | shinfo->gso_size = max(gso_size, tail_gso_size); |
2092 | shinfo->gso_segs = min_t(u32, gso_segs + tail_gso_segs, 0xFFFF); |
2093 | |
2094 | sk->sk_backlog.len += delta; |
2095 | __NET_INC_STATS(sock_net(sk), |
2096 | LINUX_MIB_TCPBACKLOGCOALESCE); |
2097 | kfree_skb_partial(skb, head_stolen: fragstolen); |
2098 | return false; |
2099 | } |
2100 | __skb_push(skb, len: hdrlen); |
2101 | |
2102 | no_coalesce: |
2103 | limit = (u32)READ_ONCE(sk->sk_rcvbuf) + (u32)(READ_ONCE(sk->sk_sndbuf) >> 1); |
2104 | |
2105 | /* Only socket owner can try to collapse/prune rx queues |
2106 | * to reduce memory overhead, so add a little headroom here. |
2107 | * Few sockets backlog are possibly concurrently non empty. |
2108 | */ |
2109 | limit += 64 * 1024; |
2110 | |
2111 | if (unlikely(sk_add_backlog(sk, skb, limit))) { |
2112 | bh_unlock_sock(sk); |
2113 | *reason = SKB_DROP_REASON_SOCKET_BACKLOG; |
2114 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPBACKLOGDROP); |
2115 | return true; |
2116 | } |
2117 | return false; |
2118 | } |
2119 | EXPORT_SYMBOL(tcp_add_backlog); |
2120 | |
2121 | int tcp_filter(struct sock *sk, struct sk_buff *skb) |
2122 | { |
2123 | struct tcphdr *th = (struct tcphdr *)skb->data; |
2124 | |
2125 | return sk_filter_trim_cap(sk, skb, cap: th->doff * 4); |
2126 | } |
2127 | EXPORT_SYMBOL(tcp_filter); |
2128 | |
2129 | static void tcp_v4_restore_cb(struct sk_buff *skb) |
2130 | { |
2131 | memmove(IPCB(skb), &TCP_SKB_CB(skb)->header.h4, |
2132 | sizeof(struct inet_skb_parm)); |
2133 | } |
2134 | |
2135 | static void tcp_v4_fill_cb(struct sk_buff *skb, const struct iphdr *iph, |
2136 | const struct tcphdr *th) |
2137 | { |
2138 | /* This is tricky : We move IPCB at its correct location into TCP_SKB_CB() |
2139 | * barrier() makes sure compiler wont play fool^Waliasing games. |
2140 | */ |
2141 | memmove(&TCP_SKB_CB(skb)->header.h4, IPCB(skb), |
2142 | sizeof(struct inet_skb_parm)); |
2143 | barrier(); |
2144 | |
2145 | TCP_SKB_CB(skb)->seq = ntohl(th->seq); |
2146 | TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + |
2147 | skb->len - th->doff * 4); |
2148 | TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); |
2149 | TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th); |
2150 | TCP_SKB_CB(skb)->tcp_tw_isn = 0; |
2151 | TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph); |
2152 | TCP_SKB_CB(skb)->sacked = 0; |
2153 | TCP_SKB_CB(skb)->has_rxtstamp = |
2154 | skb->tstamp || skb_hwtstamps(skb)->hwtstamp; |
2155 | } |
2156 | |
2157 | /* |
2158 | * From tcp_input.c |
2159 | */ |
2160 | |
2161 | int tcp_v4_rcv(struct sk_buff *skb) |
2162 | { |
2163 | struct net *net = dev_net(dev: skb->dev); |
2164 | enum skb_drop_reason drop_reason; |
2165 | int sdif = inet_sdif(skb); |
2166 | int dif = inet_iif(skb); |
2167 | const struct iphdr *iph; |
2168 | const struct tcphdr *th; |
2169 | bool refcounted; |
2170 | struct sock *sk; |
2171 | int ret; |
2172 | |
2173 | drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; |
2174 | if (skb->pkt_type != PACKET_HOST) |
2175 | goto discard_it; |
2176 | |
2177 | /* Count it even if it's bad */ |
2178 | __TCP_INC_STATS(net, TCP_MIB_INSEGS); |
2179 | |
2180 | if (!pskb_may_pull(skb, len: sizeof(struct tcphdr))) |
2181 | goto discard_it; |
2182 | |
2183 | th = (const struct tcphdr *)skb->data; |
2184 | |
2185 | if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) { |
2186 | drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL; |
2187 | goto bad_packet; |
2188 | } |
2189 | if (!pskb_may_pull(skb, len: th->doff * 4)) |
2190 | goto discard_it; |
2191 | |
2192 | /* An explanation is required here, I think. |
2193 | * Packet length and doff are validated by header prediction, |
2194 | * provided case of th->doff==0 is eliminated. |
2195 | * So, we defer the checks. */ |
2196 | |
2197 | if (skb_checksum_init(skb, IPPROTO_TCP, inet_compute_pseudo)) |
2198 | goto csum_error; |
2199 | |
2200 | th = (const struct tcphdr *)skb->data; |
2201 | iph = ip_hdr(skb); |
2202 | lookup: |
2203 | sk = __inet_lookup_skb(hashinfo: net->ipv4.tcp_death_row.hashinfo, |
2204 | skb, doff: __tcp_hdrlen(th), sport: th->source, |
2205 | dport: th->dest, sdif, refcounted: &refcounted); |
2206 | if (!sk) |
2207 | goto no_tcp_socket; |
2208 | |
2209 | process: |
2210 | if (sk->sk_state == TCP_TIME_WAIT) |
2211 | goto do_time_wait; |
2212 | |
2213 | if (sk->sk_state == TCP_NEW_SYN_RECV) { |
2214 | struct request_sock *req = inet_reqsk(sk); |
2215 | bool req_stolen = false; |
2216 | struct sock *nsk; |
2217 | |
2218 | sk = req->rsk_listener; |
2219 | if (!xfrm4_policy_check(sk, dir: XFRM_POLICY_IN, skb)) |
2220 | drop_reason = SKB_DROP_REASON_XFRM_POLICY; |
2221 | else |
2222 | drop_reason = tcp_inbound_hash(sk, req, skb, |
2223 | saddr: &iph->saddr, daddr: &iph->daddr, |
2224 | AF_INET, dif, sdif); |
2225 | if (unlikely(drop_reason)) { |
2226 | sk_drops_add(sk, skb); |
2227 | reqsk_put(req); |
2228 | goto discard_it; |
2229 | } |
2230 | if (tcp_checksum_complete(skb)) { |
2231 | reqsk_put(req); |
2232 | goto csum_error; |
2233 | } |
2234 | if (unlikely(sk->sk_state != TCP_LISTEN)) { |
2235 | nsk = reuseport_migrate_sock(sk, migrating_sk: req_to_sk(req), skb); |
2236 | if (!nsk) { |
2237 | inet_csk_reqsk_queue_drop_and_put(sk, req); |
2238 | goto lookup; |
2239 | } |
2240 | sk = nsk; |
2241 | /* reuseport_migrate_sock() has already held one sk_refcnt |
2242 | * before returning. |
2243 | */ |
2244 | } else { |
2245 | /* We own a reference on the listener, increase it again |
2246 | * as we might lose it too soon. |
2247 | */ |
2248 | sock_hold(sk); |
2249 | } |
2250 | refcounted = true; |
2251 | nsk = NULL; |
2252 | if (!tcp_filter(sk, skb)) { |
2253 | th = (const struct tcphdr *)skb->data; |
2254 | iph = ip_hdr(skb); |
2255 | tcp_v4_fill_cb(skb, iph, th); |
2256 | nsk = tcp_check_req(sk, skb, req, fastopen: false, lost_race: &req_stolen); |
2257 | } else { |
2258 | drop_reason = SKB_DROP_REASON_SOCKET_FILTER; |
2259 | } |
2260 | if (!nsk) { |
2261 | reqsk_put(req); |
2262 | if (req_stolen) { |
2263 | /* Another cpu got exclusive access to req |
2264 | * and created a full blown socket. |
2265 | * Try to feed this packet to this socket |
2266 | * instead of discarding it. |
2267 | */ |
2268 | tcp_v4_restore_cb(skb); |
2269 | sock_put(sk); |
2270 | goto lookup; |
2271 | } |
2272 | goto discard_and_relse; |
2273 | } |
2274 | nf_reset_ct(skb); |
2275 | if (nsk == sk) { |
2276 | reqsk_put(req); |
2277 | tcp_v4_restore_cb(skb); |
2278 | } else if (tcp_child_process(parent: sk, child: nsk, skb)) { |
2279 | tcp_v4_send_reset(sk: nsk, skb); |
2280 | goto discard_and_relse; |
2281 | } else { |
2282 | sock_put(sk); |
2283 | return 0; |
2284 | } |
2285 | } |
2286 | |
2287 | if (static_branch_unlikely(&ip4_min_ttl)) { |
2288 | /* min_ttl can be changed concurrently from do_ip_setsockopt() */ |
2289 | if (unlikely(iph->ttl < READ_ONCE(inet_sk(sk)->min_ttl))) { |
2290 | __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); |
2291 | drop_reason = SKB_DROP_REASON_TCP_MINTTL; |
2292 | goto discard_and_relse; |
2293 | } |
2294 | } |
2295 | |
2296 | if (!xfrm4_policy_check(sk, dir: XFRM_POLICY_IN, skb)) { |
2297 | drop_reason = SKB_DROP_REASON_XFRM_POLICY; |
2298 | goto discard_and_relse; |
2299 | } |
2300 | |
2301 | drop_reason = tcp_inbound_hash(sk, NULL, skb, saddr: &iph->saddr, daddr: &iph->daddr, |
2302 | AF_INET, dif, sdif); |
2303 | if (drop_reason) |
2304 | goto discard_and_relse; |
2305 | |
2306 | nf_reset_ct(skb); |
2307 | |
2308 | if (tcp_filter(sk, skb)) { |
2309 | drop_reason = SKB_DROP_REASON_SOCKET_FILTER; |
2310 | goto discard_and_relse; |
2311 | } |
2312 | th = (const struct tcphdr *)skb->data; |
2313 | iph = ip_hdr(skb); |
2314 | tcp_v4_fill_cb(skb, iph, th); |
2315 | |
2316 | skb->dev = NULL; |
2317 | |
2318 | if (sk->sk_state == TCP_LISTEN) { |
2319 | ret = tcp_v4_do_rcv(sk, skb); |
2320 | goto put_and_return; |
2321 | } |
2322 | |
2323 | sk_incoming_cpu_update(sk); |
2324 | |
2325 | bh_lock_sock_nested(sk); |
2326 | tcp_segs_in(tcp_sk(sk), skb); |
2327 | ret = 0; |
2328 | if (!sock_owned_by_user(sk)) { |
2329 | ret = tcp_v4_do_rcv(sk, skb); |
2330 | } else { |
2331 | if (tcp_add_backlog(sk, skb, &drop_reason)) |
2332 | goto discard_and_relse; |
2333 | } |
2334 | bh_unlock_sock(sk); |
2335 | |
2336 | put_and_return: |
2337 | if (refcounted) |
2338 | sock_put(sk); |
2339 | |
2340 | return ret; |
2341 | |
2342 | no_tcp_socket: |
2343 | drop_reason = SKB_DROP_REASON_NO_SOCKET; |
2344 | if (!xfrm4_policy_check(NULL, dir: XFRM_POLICY_IN, skb)) |
2345 | goto discard_it; |
2346 | |
2347 | tcp_v4_fill_cb(skb, iph, th); |
2348 | |
2349 | if (tcp_checksum_complete(skb)) { |
2350 | csum_error: |
2351 | drop_reason = SKB_DROP_REASON_TCP_CSUM; |
2352 | trace_tcp_bad_csum(skb); |
2353 | __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); |
2354 | bad_packet: |
2355 | __TCP_INC_STATS(net, TCP_MIB_INERRS); |
2356 | } else { |
2357 | tcp_v4_send_reset(NULL, skb); |
2358 | } |
2359 | |
2360 | discard_it: |
2361 | SKB_DR_OR(drop_reason, NOT_SPECIFIED); |
2362 | /* Discard frame. */ |
2363 | kfree_skb_reason(skb, reason: drop_reason); |
2364 | return 0; |
2365 | |
2366 | discard_and_relse: |
2367 | sk_drops_add(sk, skb); |
2368 | if (refcounted) |
2369 | sock_put(sk); |
2370 | goto discard_it; |
2371 | |
2372 | do_time_wait: |
2373 | if (!xfrm4_policy_check(NULL, dir: XFRM_POLICY_IN, skb)) { |
2374 | drop_reason = SKB_DROP_REASON_XFRM_POLICY; |
2375 | inet_twsk_put(tw: inet_twsk(sk)); |
2376 | goto discard_it; |
2377 | } |
2378 | |
2379 | tcp_v4_fill_cb(skb, iph, th); |
2380 | |
2381 | if (tcp_checksum_complete(skb)) { |
2382 | inet_twsk_put(tw: inet_twsk(sk)); |
2383 | goto csum_error; |
2384 | } |
2385 | switch (tcp_timewait_state_process(tw: inet_twsk(sk), skb, th)) { |
2386 | case TCP_TW_SYN: { |
2387 | struct sock *sk2 = inet_lookup_listener(net, |
2388 | hashinfo: net->ipv4.tcp_death_row.hashinfo, |
2389 | skb, doff: __tcp_hdrlen(th), |
2390 | saddr: iph->saddr, sport: th->source, |
2391 | daddr: iph->daddr, dport: th->dest, |
2392 | dif: inet_iif(skb), |
2393 | sdif); |
2394 | if (sk2) { |
2395 | inet_twsk_deschedule_put(tw: inet_twsk(sk)); |
2396 | sk = sk2; |
2397 | tcp_v4_restore_cb(skb); |
2398 | refcounted = false; |
2399 | goto process; |
2400 | } |
2401 | } |
2402 | /* to ACK */ |
2403 | fallthrough; |
2404 | case TCP_TW_ACK: |
2405 | tcp_v4_timewait_ack(sk, skb); |
2406 | break; |
2407 | case TCP_TW_RST: |
2408 | tcp_v4_send_reset(sk, skb); |
2409 | inet_twsk_deschedule_put(tw: inet_twsk(sk)); |
2410 | goto discard_it; |
2411 | case TCP_TW_SUCCESS:; |
2412 | } |
2413 | goto discard_it; |
2414 | } |
2415 | |
2416 | static struct timewait_sock_ops tcp_timewait_sock_ops = { |
2417 | .twsk_obj_size = sizeof(struct tcp_timewait_sock), |
2418 | .twsk_unique = tcp_twsk_unique, |
2419 | .twsk_destructor= tcp_twsk_destructor, |
2420 | }; |
2421 | |
2422 | void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb) |
2423 | { |
2424 | struct dst_entry *dst = skb_dst(skb); |
2425 | |
2426 | if (dst && dst_hold_safe(dst)) { |
2427 | rcu_assign_pointer(sk->sk_rx_dst, dst); |
2428 | sk->sk_rx_dst_ifindex = skb->skb_iif; |
2429 | } |
2430 | } |
2431 | EXPORT_SYMBOL(inet_sk_rx_dst_set); |
2432 | |
2433 | const struct inet_connection_sock_af_ops ipv4_specific = { |
2434 | .queue_xmit = ip_queue_xmit, |
2435 | .send_check = tcp_v4_send_check, |
2436 | .rebuild_header = inet_sk_rebuild_header, |
2437 | .sk_rx_dst_set = inet_sk_rx_dst_set, |
2438 | .conn_request = tcp_v4_conn_request, |
2439 | .syn_recv_sock = tcp_v4_syn_recv_sock, |
2440 | .net_header_len = sizeof(struct iphdr), |
2441 | .setsockopt = ip_setsockopt, |
2442 | .getsockopt = ip_getsockopt, |
2443 | .addr2sockaddr = inet_csk_addr2sockaddr, |
2444 | .sockaddr_len = sizeof(struct sockaddr_in), |
2445 | .mtu_reduced = tcp_v4_mtu_reduced, |
2446 | }; |
2447 | EXPORT_SYMBOL(ipv4_specific); |
2448 | |
2449 | #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) |
2450 | static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = { |
2451 | #ifdef CONFIG_TCP_MD5SIG |
2452 | .md5_lookup = tcp_v4_md5_lookup, |
2453 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
2454 | .md5_parse = tcp_v4_parse_md5_keys, |
2455 | #endif |
2456 | #ifdef CONFIG_TCP_AO |
2457 | .ao_lookup = tcp_v4_ao_lookup, |
2458 | .calc_ao_hash = tcp_v4_ao_hash_skb, |
2459 | .ao_parse = tcp_v4_parse_ao, |
2460 | .ao_calc_key_sk = tcp_v4_ao_calc_key_sk, |
2461 | #endif |
2462 | }; |
2463 | #endif |
2464 | |
2465 | /* NOTE: A lot of things set to zero explicitly by call to |
2466 | * sk_alloc() so need not be done here. |
2467 | */ |
2468 | static int tcp_v4_init_sock(struct sock *sk) |
2469 | { |
2470 | struct inet_connection_sock *icsk = inet_csk(sk); |
2471 | |
2472 | tcp_init_sock(sk); |
2473 | |
2474 | icsk->icsk_af_ops = &ipv4_specific; |
2475 | |
2476 | #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) |
2477 | tcp_sk(sk)->af_specific = &tcp_sock_ipv4_specific; |
2478 | #endif |
2479 | |
2480 | return 0; |
2481 | } |
2482 | |
2483 | #ifdef CONFIG_TCP_MD5SIG |
2484 | static void tcp_md5sig_info_free_rcu(struct rcu_head *head) |
2485 | { |
2486 | struct tcp_md5sig_info *md5sig; |
2487 | |
2488 | md5sig = container_of(head, struct tcp_md5sig_info, rcu); |
2489 | kfree(objp: md5sig); |
2490 | static_branch_slow_dec_deferred(&tcp_md5_needed); |
2491 | tcp_md5_release_sigpool(); |
2492 | } |
2493 | #endif |
2494 | |
2495 | void tcp_v4_destroy_sock(struct sock *sk) |
2496 | { |
2497 | struct tcp_sock *tp = tcp_sk(sk); |
2498 | |
2499 | trace_tcp_destroy_sock(sk); |
2500 | |
2501 | tcp_clear_xmit_timers(sk); |
2502 | |
2503 | tcp_cleanup_congestion_control(sk); |
2504 | |
2505 | tcp_cleanup_ulp(sk); |
2506 | |
2507 | /* Cleanup up the write buffer. */ |
2508 | tcp_write_queue_purge(sk); |
2509 | |
2510 | /* Check if we want to disable active TFO */ |
2511 | tcp_fastopen_active_disable_ofo_check(sk); |
2512 | |
2513 | /* Cleans up our, hopefully empty, out_of_order_queue. */ |
2514 | skb_rbtree_purge(root: &tp->out_of_order_queue); |
2515 | |
2516 | #ifdef CONFIG_TCP_MD5SIG |
2517 | /* Clean up the MD5 key list, if any */ |
2518 | if (tp->md5sig_info) { |
2519 | struct tcp_md5sig_info *md5sig; |
2520 | |
2521 | md5sig = rcu_dereference_protected(tp->md5sig_info, 1); |
2522 | tcp_clear_md5_list(sk); |
2523 | call_rcu(head: &md5sig->rcu, func: tcp_md5sig_info_free_rcu); |
2524 | rcu_assign_pointer(tp->md5sig_info, NULL); |
2525 | } |
2526 | #endif |
2527 | tcp_ao_destroy_sock(sk, twsk: false); |
2528 | |
2529 | /* Clean up a referenced TCP bind bucket. */ |
2530 | if (inet_csk(sk)->icsk_bind_hash) |
2531 | inet_put_port(sk); |
2532 | |
2533 | BUG_ON(rcu_access_pointer(tp->fastopen_rsk)); |
2534 | |
2535 | /* If socket is aborted during connect operation */ |
2536 | tcp_free_fastopen_req(tp); |
2537 | tcp_fastopen_destroy_cipher(sk); |
2538 | tcp_saved_syn_free(tp); |
2539 | |
2540 | sk_sockets_allocated_dec(sk); |
2541 | } |
2542 | EXPORT_SYMBOL(tcp_v4_destroy_sock); |
2543 | |
2544 | #ifdef CONFIG_PROC_FS |
2545 | /* Proc filesystem TCP sock list dumping. */ |
2546 | |
2547 | static unsigned short seq_file_family(const struct seq_file *seq); |
2548 | |
2549 | static bool seq_sk_match(struct seq_file *seq, const struct sock *sk) |
2550 | { |
2551 | unsigned short family = seq_file_family(seq); |
2552 | |
2553 | /* AF_UNSPEC is used as a match all */ |
2554 | return ((family == AF_UNSPEC || family == sk->sk_family) && |
2555 | net_eq(net1: sock_net(sk), net2: seq_file_net(seq))); |
2556 | } |
2557 | |
2558 | /* Find a non empty bucket (starting from st->bucket) |
2559 | * and return the first sk from it. |
2560 | */ |
2561 | static void *listening_get_first(struct seq_file *seq) |
2562 | { |
2563 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
2564 | struct tcp_iter_state *st = seq->private; |
2565 | |
2566 | st->offset = 0; |
2567 | for (; st->bucket <= hinfo->lhash2_mask; st->bucket++) { |
2568 | struct inet_listen_hashbucket *ilb2; |
2569 | struct hlist_nulls_node *node; |
2570 | struct sock *sk; |
2571 | |
2572 | ilb2 = &hinfo->lhash2[st->bucket]; |
2573 | if (hlist_nulls_empty(h: &ilb2->nulls_head)) |
2574 | continue; |
2575 | |
2576 | spin_lock(lock: &ilb2->lock); |
2577 | sk_nulls_for_each(sk, node, &ilb2->nulls_head) { |
2578 | if (seq_sk_match(seq, sk)) |
2579 | return sk; |
2580 | } |
2581 | spin_unlock(lock: &ilb2->lock); |
2582 | } |
2583 | |
2584 | return NULL; |
2585 | } |
2586 | |
2587 | /* Find the next sk of "cur" within the same bucket (i.e. st->bucket). |
2588 | * If "cur" is the last one in the st->bucket, |
2589 | * call listening_get_first() to return the first sk of the next |
2590 | * non empty bucket. |
2591 | */ |
2592 | static void *listening_get_next(struct seq_file *seq, void *cur) |
2593 | { |
2594 | struct tcp_iter_state *st = seq->private; |
2595 | struct inet_listen_hashbucket *ilb2; |
2596 | struct hlist_nulls_node *node; |
2597 | struct inet_hashinfo *hinfo; |
2598 | struct sock *sk = cur; |
2599 | |
2600 | ++st->num; |
2601 | ++st->offset; |
2602 | |
2603 | sk = sk_nulls_next(sk); |
2604 | sk_nulls_for_each_from(sk, node) { |
2605 | if (seq_sk_match(seq, sk)) |
2606 | return sk; |
2607 | } |
2608 | |
2609 | hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
2610 | ilb2 = &hinfo->lhash2[st->bucket]; |
2611 | spin_unlock(lock: &ilb2->lock); |
2612 | ++st->bucket; |
2613 | return listening_get_first(seq); |
2614 | } |
2615 | |
2616 | static void *listening_get_idx(struct seq_file *seq, loff_t *pos) |
2617 | { |
2618 | struct tcp_iter_state *st = seq->private; |
2619 | void *rc; |
2620 | |
2621 | st->bucket = 0; |
2622 | st->offset = 0; |
2623 | rc = listening_get_first(seq); |
2624 | |
2625 | while (rc && *pos) { |
2626 | rc = listening_get_next(seq, cur: rc); |
2627 | --*pos; |
2628 | } |
2629 | return rc; |
2630 | } |
2631 | |
2632 | static inline bool empty_bucket(struct inet_hashinfo *hinfo, |
2633 | const struct tcp_iter_state *st) |
2634 | { |
2635 | return hlist_nulls_empty(h: &hinfo->ehash[st->bucket].chain); |
2636 | } |
2637 | |
2638 | /* |
2639 | * Get first established socket starting from bucket given in st->bucket. |
2640 | * If st->bucket is zero, the very first socket in the hash is returned. |
2641 | */ |
2642 | static void *established_get_first(struct seq_file *seq) |
2643 | { |
2644 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
2645 | struct tcp_iter_state *st = seq->private; |
2646 | |
2647 | st->offset = 0; |
2648 | for (; st->bucket <= hinfo->ehash_mask; ++st->bucket) { |
2649 | struct sock *sk; |
2650 | struct hlist_nulls_node *node; |
2651 | spinlock_t *lock = inet_ehash_lockp(hashinfo: hinfo, hash: st->bucket); |
2652 | |
2653 | cond_resched(); |
2654 | |
2655 | /* Lockless fast path for the common case of empty buckets */ |
2656 | if (empty_bucket(hinfo, st)) |
2657 | continue; |
2658 | |
2659 | spin_lock_bh(lock); |
2660 | sk_nulls_for_each(sk, node, &hinfo->ehash[st->bucket].chain) { |
2661 | if (seq_sk_match(seq, sk)) |
2662 | return sk; |
2663 | } |
2664 | spin_unlock_bh(lock); |
2665 | } |
2666 | |
2667 | return NULL; |
2668 | } |
2669 | |
2670 | static void *established_get_next(struct seq_file *seq, void *cur) |
2671 | { |
2672 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
2673 | struct tcp_iter_state *st = seq->private; |
2674 | struct hlist_nulls_node *node; |
2675 | struct sock *sk = cur; |
2676 | |
2677 | ++st->num; |
2678 | ++st->offset; |
2679 | |
2680 | sk = sk_nulls_next(sk); |
2681 | |
2682 | sk_nulls_for_each_from(sk, node) { |
2683 | if (seq_sk_match(seq, sk)) |
2684 | return sk; |
2685 | } |
2686 | |
2687 | spin_unlock_bh(lock: inet_ehash_lockp(hashinfo: hinfo, hash: st->bucket)); |
2688 | ++st->bucket; |
2689 | return established_get_first(seq); |
2690 | } |
2691 | |
2692 | static void *established_get_idx(struct seq_file *seq, loff_t pos) |
2693 | { |
2694 | struct tcp_iter_state *st = seq->private; |
2695 | void *rc; |
2696 | |
2697 | st->bucket = 0; |
2698 | rc = established_get_first(seq); |
2699 | |
2700 | while (rc && pos) { |
2701 | rc = established_get_next(seq, cur: rc); |
2702 | --pos; |
2703 | } |
2704 | return rc; |
2705 | } |
2706 | |
2707 | static void *tcp_get_idx(struct seq_file *seq, loff_t pos) |
2708 | { |
2709 | void *rc; |
2710 | struct tcp_iter_state *st = seq->private; |
2711 | |
2712 | st->state = TCP_SEQ_STATE_LISTENING; |
2713 | rc = listening_get_idx(seq, pos: &pos); |
2714 | |
2715 | if (!rc) { |
2716 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2717 | rc = established_get_idx(seq, pos); |
2718 | } |
2719 | |
2720 | return rc; |
2721 | } |
2722 | |
2723 | static void *tcp_seek_last_pos(struct seq_file *seq) |
2724 | { |
2725 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
2726 | struct tcp_iter_state *st = seq->private; |
2727 | int bucket = st->bucket; |
2728 | int offset = st->offset; |
2729 | int orig_num = st->num; |
2730 | void *rc = NULL; |
2731 | |
2732 | switch (st->state) { |
2733 | case TCP_SEQ_STATE_LISTENING: |
2734 | if (st->bucket > hinfo->lhash2_mask) |
2735 | break; |
2736 | rc = listening_get_first(seq); |
2737 | while (offset-- && rc && bucket == st->bucket) |
2738 | rc = listening_get_next(seq, cur: rc); |
2739 | if (rc) |
2740 | break; |
2741 | st->bucket = 0; |
2742 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2743 | fallthrough; |
2744 | case TCP_SEQ_STATE_ESTABLISHED: |
2745 | if (st->bucket > hinfo->ehash_mask) |
2746 | break; |
2747 | rc = established_get_first(seq); |
2748 | while (offset-- && rc && bucket == st->bucket) |
2749 | rc = established_get_next(seq, cur: rc); |
2750 | } |
2751 | |
2752 | st->num = orig_num; |
2753 | |
2754 | return rc; |
2755 | } |
2756 | |
2757 | void *tcp_seq_start(struct seq_file *seq, loff_t *pos) |
2758 | { |
2759 | struct tcp_iter_state *st = seq->private; |
2760 | void *rc; |
2761 | |
2762 | if (*pos && *pos == st->last_pos) { |
2763 | rc = tcp_seek_last_pos(seq); |
2764 | if (rc) |
2765 | goto out; |
2766 | } |
2767 | |
2768 | st->state = TCP_SEQ_STATE_LISTENING; |
2769 | st->num = 0; |
2770 | st->bucket = 0; |
2771 | st->offset = 0; |
2772 | rc = *pos ? tcp_get_idx(seq, pos: *pos - 1) : SEQ_START_TOKEN; |
2773 | |
2774 | out: |
2775 | st->last_pos = *pos; |
2776 | return rc; |
2777 | } |
2778 | EXPORT_SYMBOL(tcp_seq_start); |
2779 | |
2780 | void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
2781 | { |
2782 | struct tcp_iter_state *st = seq->private; |
2783 | void *rc = NULL; |
2784 | |
2785 | if (v == SEQ_START_TOKEN) { |
2786 | rc = tcp_get_idx(seq, pos: 0); |
2787 | goto out; |
2788 | } |
2789 | |
2790 | switch (st->state) { |
2791 | case TCP_SEQ_STATE_LISTENING: |
2792 | rc = listening_get_next(seq, cur: v); |
2793 | if (!rc) { |
2794 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2795 | st->bucket = 0; |
2796 | st->offset = 0; |
2797 | rc = established_get_first(seq); |
2798 | } |
2799 | break; |
2800 | case TCP_SEQ_STATE_ESTABLISHED: |
2801 | rc = established_get_next(seq, cur: v); |
2802 | break; |
2803 | } |
2804 | out: |
2805 | ++*pos; |
2806 | st->last_pos = *pos; |
2807 | return rc; |
2808 | } |
2809 | EXPORT_SYMBOL(tcp_seq_next); |
2810 | |
2811 | void tcp_seq_stop(struct seq_file *seq, void *v) |
2812 | { |
2813 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
2814 | struct tcp_iter_state *st = seq->private; |
2815 | |
2816 | switch (st->state) { |
2817 | case TCP_SEQ_STATE_LISTENING: |
2818 | if (v != SEQ_START_TOKEN) |
2819 | spin_unlock(lock: &hinfo->lhash2[st->bucket].lock); |
2820 | break; |
2821 | case TCP_SEQ_STATE_ESTABLISHED: |
2822 | if (v) |
2823 | spin_unlock_bh(lock: inet_ehash_lockp(hashinfo: hinfo, hash: st->bucket)); |
2824 | break; |
2825 | } |
2826 | } |
2827 | EXPORT_SYMBOL(tcp_seq_stop); |
2828 | |
2829 | static void get_openreq4(const struct request_sock *req, |
2830 | struct seq_file *f, int i) |
2831 | { |
2832 | const struct inet_request_sock *ireq = inet_rsk(sk: req); |
2833 | long delta = req->rsk_timer.expires - jiffies; |
2834 | |
2835 | seq_printf(m: f, fmt: "%4d: %08X:%04X %08X:%04X" |
2836 | " %02X %08X:%08X %02X:%08lX %08X %5u %8d %u %d %pK" , |
2837 | i, |
2838 | ireq->ir_loc_addr, |
2839 | ireq->ir_num, |
2840 | ireq->ir_rmt_addr, |
2841 | ntohs(ireq->ir_rmt_port), |
2842 | TCP_SYN_RECV, |
2843 | 0, 0, /* could print option size, but that is af dependent. */ |
2844 | 1, /* timers active (only the expire timer) */ |
2845 | jiffies_delta_to_clock_t(delta), |
2846 | req->num_timeout, |
2847 | from_kuid_munged(to: seq_user_ns(seq: f), |
2848 | uid: sock_i_uid(sk: req->rsk_listener)), |
2849 | 0, /* non standard timer */ |
2850 | 0, /* open_requests have no inode */ |
2851 | 0, |
2852 | req); |
2853 | } |
2854 | |
2855 | static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i) |
2856 | { |
2857 | int timer_active; |
2858 | unsigned long timer_expires; |
2859 | const struct tcp_sock *tp = tcp_sk(sk); |
2860 | const struct inet_connection_sock *icsk = inet_csk(sk); |
2861 | const struct inet_sock *inet = inet_sk(sk); |
2862 | const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq; |
2863 | __be32 dest = inet->inet_daddr; |
2864 | __be32 src = inet->inet_rcv_saddr; |
2865 | __u16 destp = ntohs(inet->inet_dport); |
2866 | __u16 srcp = ntohs(inet->inet_sport); |
2867 | int rx_queue; |
2868 | int state; |
2869 | |
2870 | if (icsk->icsk_pending == ICSK_TIME_RETRANS || |
2871 | icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || |
2872 | icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { |
2873 | timer_active = 1; |
2874 | timer_expires = icsk->icsk_timeout; |
2875 | } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { |
2876 | timer_active = 4; |
2877 | timer_expires = icsk->icsk_timeout; |
2878 | } else if (timer_pending(timer: &sk->sk_timer)) { |
2879 | timer_active = 2; |
2880 | timer_expires = sk->sk_timer.expires; |
2881 | } else { |
2882 | timer_active = 0; |
2883 | timer_expires = jiffies; |
2884 | } |
2885 | |
2886 | state = inet_sk_state_load(sk); |
2887 | if (state == TCP_LISTEN) |
2888 | rx_queue = READ_ONCE(sk->sk_ack_backlog); |
2889 | else |
2890 | /* Because we don't lock the socket, |
2891 | * we might find a transient negative value. |
2892 | */ |
2893 | rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) - |
2894 | READ_ONCE(tp->copied_seq), 0); |
2895 | |
2896 | seq_printf(m: f, fmt: "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX " |
2897 | "%08X %5u %8d %lu %d %pK %lu %lu %u %u %d" , |
2898 | i, src, srcp, dest, destp, state, |
2899 | READ_ONCE(tp->write_seq) - tp->snd_una, |
2900 | rx_queue, |
2901 | timer_active, |
2902 | jiffies_delta_to_clock_t(delta: timer_expires - jiffies), |
2903 | icsk->icsk_retransmits, |
2904 | from_kuid_munged(to: seq_user_ns(seq: f), uid: sock_i_uid(sk)), |
2905 | icsk->icsk_probes_out, |
2906 | sock_i_ino(sk), |
2907 | refcount_read(r: &sk->sk_refcnt), sk, |
2908 | jiffies_to_clock_t(x: icsk->icsk_rto), |
2909 | jiffies_to_clock_t(x: icsk->icsk_ack.ato), |
2910 | (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sk), |
2911 | tcp_snd_cwnd(tp), |
2912 | state == TCP_LISTEN ? |
2913 | fastopenq->max_qlen : |
2914 | (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)); |
2915 | } |
2916 | |
2917 | static void get_timewait4_sock(const struct inet_timewait_sock *tw, |
2918 | struct seq_file *f, int i) |
2919 | { |
2920 | long delta = tw->tw_timer.expires - jiffies; |
2921 | __be32 dest, src; |
2922 | __u16 destp, srcp; |
2923 | |
2924 | dest = tw->tw_daddr; |
2925 | src = tw->tw_rcv_saddr; |
2926 | destp = ntohs(tw->tw_dport); |
2927 | srcp = ntohs(tw->tw_sport); |
2928 | |
2929 | seq_printf(m: f, fmt: "%4d: %08X:%04X %08X:%04X" |
2930 | " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK" , |
2931 | i, src, srcp, dest, destp, tw->tw_substate, 0, 0, |
2932 | 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0, |
2933 | refcount_read(r: &tw->tw_refcnt), tw); |
2934 | } |
2935 | |
2936 | #define TMPSZ 150 |
2937 | |
2938 | static int tcp4_seq_show(struct seq_file *seq, void *v) |
2939 | { |
2940 | struct tcp_iter_state *st; |
2941 | struct sock *sk = v; |
2942 | |
2943 | seq_setwidth(m: seq, TMPSZ - 1); |
2944 | if (v == SEQ_START_TOKEN) { |
2945 | seq_puts(m: seq, s: " sl local_address rem_address st tx_queue " |
2946 | "rx_queue tr tm->when retrnsmt uid timeout " |
2947 | "inode" ); |
2948 | goto out; |
2949 | } |
2950 | st = seq->private; |
2951 | |
2952 | if (sk->sk_state == TCP_TIME_WAIT) |
2953 | get_timewait4_sock(tw: v, f: seq, i: st->num); |
2954 | else if (sk->sk_state == TCP_NEW_SYN_RECV) |
2955 | get_openreq4(req: v, f: seq, i: st->num); |
2956 | else |
2957 | get_tcp4_sock(sk: v, f: seq, i: st->num); |
2958 | out: |
2959 | seq_pad(m: seq, c: '\n'); |
2960 | return 0; |
2961 | } |
2962 | |
2963 | #ifdef CONFIG_BPF_SYSCALL |
2964 | struct bpf_tcp_iter_state { |
2965 | struct tcp_iter_state state; |
2966 | unsigned int cur_sk; |
2967 | unsigned int end_sk; |
2968 | unsigned int max_sk; |
2969 | struct sock **batch; |
2970 | bool st_bucket_done; |
2971 | }; |
2972 | |
2973 | struct bpf_iter__tcp { |
2974 | __bpf_md_ptr(struct bpf_iter_meta *, meta); |
2975 | __bpf_md_ptr(struct sock_common *, sk_common); |
2976 | uid_t uid __aligned(8); |
2977 | }; |
2978 | |
2979 | static int tcp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta, |
2980 | struct sock_common *sk_common, uid_t uid) |
2981 | { |
2982 | struct bpf_iter__tcp ctx; |
2983 | |
2984 | meta->seq_num--; /* skip SEQ_START_TOKEN */ |
2985 | ctx.meta = meta; |
2986 | ctx.sk_common = sk_common; |
2987 | ctx.uid = uid; |
2988 | return bpf_iter_run_prog(prog, ctx: &ctx); |
2989 | } |
2990 | |
2991 | static void bpf_iter_tcp_put_batch(struct bpf_tcp_iter_state *iter) |
2992 | { |
2993 | while (iter->cur_sk < iter->end_sk) |
2994 | sock_gen_put(sk: iter->batch[iter->cur_sk++]); |
2995 | } |
2996 | |
2997 | static int bpf_iter_tcp_realloc_batch(struct bpf_tcp_iter_state *iter, |
2998 | unsigned int new_batch_sz) |
2999 | { |
3000 | struct sock **new_batch; |
3001 | |
3002 | new_batch = kvmalloc(size: sizeof(*new_batch) * new_batch_sz, |
3003 | GFP_USER | __GFP_NOWARN); |
3004 | if (!new_batch) |
3005 | return -ENOMEM; |
3006 | |
3007 | bpf_iter_tcp_put_batch(iter); |
3008 | kvfree(addr: iter->batch); |
3009 | iter->batch = new_batch; |
3010 | iter->max_sk = new_batch_sz; |
3011 | |
3012 | return 0; |
3013 | } |
3014 | |
3015 | static unsigned int bpf_iter_tcp_listening_batch(struct seq_file *seq, |
3016 | struct sock *start_sk) |
3017 | { |
3018 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
3019 | struct bpf_tcp_iter_state *iter = seq->private; |
3020 | struct tcp_iter_state *st = &iter->state; |
3021 | struct hlist_nulls_node *node; |
3022 | unsigned int expected = 1; |
3023 | struct sock *sk; |
3024 | |
3025 | sock_hold(sk: start_sk); |
3026 | iter->batch[iter->end_sk++] = start_sk; |
3027 | |
3028 | sk = sk_nulls_next(sk: start_sk); |
3029 | sk_nulls_for_each_from(sk, node) { |
3030 | if (seq_sk_match(seq, sk)) { |
3031 | if (iter->end_sk < iter->max_sk) { |
3032 | sock_hold(sk); |
3033 | iter->batch[iter->end_sk++] = sk; |
3034 | } |
3035 | expected++; |
3036 | } |
3037 | } |
3038 | spin_unlock(lock: &hinfo->lhash2[st->bucket].lock); |
3039 | |
3040 | return expected; |
3041 | } |
3042 | |
3043 | static unsigned int bpf_iter_tcp_established_batch(struct seq_file *seq, |
3044 | struct sock *start_sk) |
3045 | { |
3046 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
3047 | struct bpf_tcp_iter_state *iter = seq->private; |
3048 | struct tcp_iter_state *st = &iter->state; |
3049 | struct hlist_nulls_node *node; |
3050 | unsigned int expected = 1; |
3051 | struct sock *sk; |
3052 | |
3053 | sock_hold(sk: start_sk); |
3054 | iter->batch[iter->end_sk++] = start_sk; |
3055 | |
3056 | sk = sk_nulls_next(sk: start_sk); |
3057 | sk_nulls_for_each_from(sk, node) { |
3058 | if (seq_sk_match(seq, sk)) { |
3059 | if (iter->end_sk < iter->max_sk) { |
3060 | sock_hold(sk); |
3061 | iter->batch[iter->end_sk++] = sk; |
3062 | } |
3063 | expected++; |
3064 | } |
3065 | } |
3066 | spin_unlock_bh(lock: inet_ehash_lockp(hashinfo: hinfo, hash: st->bucket)); |
3067 | |
3068 | return expected; |
3069 | } |
3070 | |
3071 | static struct sock *bpf_iter_tcp_batch(struct seq_file *seq) |
3072 | { |
3073 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
3074 | struct bpf_tcp_iter_state *iter = seq->private; |
3075 | struct tcp_iter_state *st = &iter->state; |
3076 | unsigned int expected; |
3077 | bool resized = false; |
3078 | struct sock *sk; |
3079 | |
3080 | /* The st->bucket is done. Directly advance to the next |
3081 | * bucket instead of having the tcp_seek_last_pos() to skip |
3082 | * one by one in the current bucket and eventually find out |
3083 | * it has to advance to the next bucket. |
3084 | */ |
3085 | if (iter->st_bucket_done) { |
3086 | st->offset = 0; |
3087 | st->bucket++; |
3088 | if (st->state == TCP_SEQ_STATE_LISTENING && |
3089 | st->bucket > hinfo->lhash2_mask) { |
3090 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
3091 | st->bucket = 0; |
3092 | } |
3093 | } |
3094 | |
3095 | again: |
3096 | /* Get a new batch */ |
3097 | iter->cur_sk = 0; |
3098 | iter->end_sk = 0; |
3099 | iter->st_bucket_done = false; |
3100 | |
3101 | sk = tcp_seek_last_pos(seq); |
3102 | if (!sk) |
3103 | return NULL; /* Done */ |
3104 | |
3105 | if (st->state == TCP_SEQ_STATE_LISTENING) |
3106 | expected = bpf_iter_tcp_listening_batch(seq, start_sk: sk); |
3107 | else |
3108 | expected = bpf_iter_tcp_established_batch(seq, start_sk: sk); |
3109 | |
3110 | if (iter->end_sk == expected) { |
3111 | iter->st_bucket_done = true; |
3112 | return sk; |
3113 | } |
3114 | |
3115 | if (!resized && !bpf_iter_tcp_realloc_batch(iter, new_batch_sz: expected * 3 / 2)) { |
3116 | resized = true; |
3117 | goto again; |
3118 | } |
3119 | |
3120 | return sk; |
3121 | } |
3122 | |
3123 | static void *bpf_iter_tcp_seq_start(struct seq_file *seq, loff_t *pos) |
3124 | { |
3125 | /* bpf iter does not support lseek, so it always |
3126 | * continue from where it was stop()-ped. |
3127 | */ |
3128 | if (*pos) |
3129 | return bpf_iter_tcp_batch(seq); |
3130 | |
3131 | return SEQ_START_TOKEN; |
3132 | } |
3133 | |
3134 | static void *bpf_iter_tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
3135 | { |
3136 | struct bpf_tcp_iter_state *iter = seq->private; |
3137 | struct tcp_iter_state *st = &iter->state; |
3138 | struct sock *sk; |
3139 | |
3140 | /* Whenever seq_next() is called, the iter->cur_sk is |
3141 | * done with seq_show(), so advance to the next sk in |
3142 | * the batch. |
3143 | */ |
3144 | if (iter->cur_sk < iter->end_sk) { |
3145 | /* Keeping st->num consistent in tcp_iter_state. |
3146 | * bpf_iter_tcp does not use st->num. |
3147 | * meta.seq_num is used instead. |
3148 | */ |
3149 | st->num++; |
3150 | /* Move st->offset to the next sk in the bucket such that |
3151 | * the future start() will resume at st->offset in |
3152 | * st->bucket. See tcp_seek_last_pos(). |
3153 | */ |
3154 | st->offset++; |
3155 | sock_gen_put(sk: iter->batch[iter->cur_sk++]); |
3156 | } |
3157 | |
3158 | if (iter->cur_sk < iter->end_sk) |
3159 | sk = iter->batch[iter->cur_sk]; |
3160 | else |
3161 | sk = bpf_iter_tcp_batch(seq); |
3162 | |
3163 | ++*pos; |
3164 | /* Keeping st->last_pos consistent in tcp_iter_state. |
3165 | * bpf iter does not do lseek, so st->last_pos always equals to *pos. |
3166 | */ |
3167 | st->last_pos = *pos; |
3168 | return sk; |
3169 | } |
3170 | |
3171 | static int bpf_iter_tcp_seq_show(struct seq_file *seq, void *v) |
3172 | { |
3173 | struct bpf_iter_meta meta; |
3174 | struct bpf_prog *prog; |
3175 | struct sock *sk = v; |
3176 | uid_t uid; |
3177 | int ret; |
3178 | |
3179 | if (v == SEQ_START_TOKEN) |
3180 | return 0; |
3181 | |
3182 | if (sk_fullsock(sk)) |
3183 | lock_sock(sk); |
3184 | |
3185 | if (unlikely(sk_unhashed(sk))) { |
3186 | ret = SEQ_SKIP; |
3187 | goto unlock; |
3188 | } |
3189 | |
3190 | if (sk->sk_state == TCP_TIME_WAIT) { |
3191 | uid = 0; |
3192 | } else if (sk->sk_state == TCP_NEW_SYN_RECV) { |
3193 | const struct request_sock *req = v; |
3194 | |
3195 | uid = from_kuid_munged(to: seq_user_ns(seq), |
3196 | uid: sock_i_uid(sk: req->rsk_listener)); |
3197 | } else { |
3198 | uid = from_kuid_munged(to: seq_user_ns(seq), uid: sock_i_uid(sk)); |
3199 | } |
3200 | |
3201 | meta.seq = seq; |
3202 | prog = bpf_iter_get_info(meta: &meta, in_stop: false); |
3203 | ret = tcp_prog_seq_show(prog, meta: &meta, sk_common: v, uid); |
3204 | |
3205 | unlock: |
3206 | if (sk_fullsock(sk)) |
3207 | release_sock(sk); |
3208 | return ret; |
3209 | |
3210 | } |
3211 | |
3212 | static void bpf_iter_tcp_seq_stop(struct seq_file *seq, void *v) |
3213 | { |
3214 | struct bpf_tcp_iter_state *iter = seq->private; |
3215 | struct bpf_iter_meta meta; |
3216 | struct bpf_prog *prog; |
3217 | |
3218 | if (!v) { |
3219 | meta.seq = seq; |
3220 | prog = bpf_iter_get_info(meta: &meta, in_stop: true); |
3221 | if (prog) |
3222 | (void)tcp_prog_seq_show(prog, meta: &meta, sk_common: v, uid: 0); |
3223 | } |
3224 | |
3225 | if (iter->cur_sk < iter->end_sk) { |
3226 | bpf_iter_tcp_put_batch(iter); |
3227 | iter->st_bucket_done = false; |
3228 | } |
3229 | } |
3230 | |
3231 | static const struct seq_operations bpf_iter_tcp_seq_ops = { |
3232 | .show = bpf_iter_tcp_seq_show, |
3233 | .start = bpf_iter_tcp_seq_start, |
3234 | .next = bpf_iter_tcp_seq_next, |
3235 | .stop = bpf_iter_tcp_seq_stop, |
3236 | }; |
3237 | #endif |
3238 | static unsigned short seq_file_family(const struct seq_file *seq) |
3239 | { |
3240 | const struct tcp_seq_afinfo *afinfo; |
3241 | |
3242 | #ifdef CONFIG_BPF_SYSCALL |
3243 | /* Iterated from bpf_iter. Let the bpf prog to filter instead. */ |
3244 | if (seq->op == &bpf_iter_tcp_seq_ops) |
3245 | return AF_UNSPEC; |
3246 | #endif |
3247 | |
3248 | /* Iterated from proc fs */ |
3249 | afinfo = pde_data(inode: file_inode(f: seq->file)); |
3250 | return afinfo->family; |
3251 | } |
3252 | |
3253 | static const struct seq_operations tcp4_seq_ops = { |
3254 | .show = tcp4_seq_show, |
3255 | .start = tcp_seq_start, |
3256 | .next = tcp_seq_next, |
3257 | .stop = tcp_seq_stop, |
3258 | }; |
3259 | |
3260 | static struct tcp_seq_afinfo tcp4_seq_afinfo = { |
3261 | .family = AF_INET, |
3262 | }; |
3263 | |
3264 | static int __net_init tcp4_proc_init_net(struct net *net) |
3265 | { |
3266 | if (!proc_create_net_data(name: "tcp" , mode: 0444, parent: net->proc_net, ops: &tcp4_seq_ops, |
3267 | state_size: sizeof(struct tcp_iter_state), data: &tcp4_seq_afinfo)) |
3268 | return -ENOMEM; |
3269 | return 0; |
3270 | } |
3271 | |
3272 | static void __net_exit tcp4_proc_exit_net(struct net *net) |
3273 | { |
3274 | remove_proc_entry("tcp" , net->proc_net); |
3275 | } |
3276 | |
3277 | static struct pernet_operations tcp4_net_ops = { |
3278 | .init = tcp4_proc_init_net, |
3279 | .exit = tcp4_proc_exit_net, |
3280 | }; |
3281 | |
3282 | int __init tcp4_proc_init(void) |
3283 | { |
3284 | return register_pernet_subsys(&tcp4_net_ops); |
3285 | } |
3286 | |
3287 | void tcp4_proc_exit(void) |
3288 | { |
3289 | unregister_pernet_subsys(&tcp4_net_ops); |
3290 | } |
3291 | #endif /* CONFIG_PROC_FS */ |
3292 | |
3293 | /* @wake is one when sk_stream_write_space() calls us. |
3294 | * This sends EPOLLOUT only if notsent_bytes is half the limit. |
3295 | * This mimics the strategy used in sock_def_write_space(). |
3296 | */ |
3297 | bool tcp_stream_memory_free(const struct sock *sk, int wake) |
3298 | { |
3299 | const struct tcp_sock *tp = tcp_sk(sk); |
3300 | u32 notsent_bytes = READ_ONCE(tp->write_seq) - |
3301 | READ_ONCE(tp->snd_nxt); |
3302 | |
3303 | return (notsent_bytes << wake) < tcp_notsent_lowat(tp); |
3304 | } |
3305 | EXPORT_SYMBOL(tcp_stream_memory_free); |
3306 | |
3307 | struct proto tcp_prot = { |
3308 | .name = "TCP" , |
3309 | .owner = THIS_MODULE, |
3310 | .close = tcp_close, |
3311 | .pre_connect = tcp_v4_pre_connect, |
3312 | .connect = tcp_v4_connect, |
3313 | .disconnect = tcp_disconnect, |
3314 | .accept = inet_csk_accept, |
3315 | .ioctl = tcp_ioctl, |
3316 | .init = tcp_v4_init_sock, |
3317 | .destroy = tcp_v4_destroy_sock, |
3318 | .shutdown = tcp_shutdown, |
3319 | .setsockopt = tcp_setsockopt, |
3320 | .getsockopt = tcp_getsockopt, |
3321 | .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt, |
3322 | .keepalive = tcp_set_keepalive, |
3323 | .recvmsg = tcp_recvmsg, |
3324 | .sendmsg = tcp_sendmsg, |
3325 | .splice_eof = tcp_splice_eof, |
3326 | .backlog_rcv = tcp_v4_do_rcv, |
3327 | .release_cb = tcp_release_cb, |
3328 | .hash = inet_hash, |
3329 | .unhash = inet_unhash, |
3330 | .get_port = inet_csk_get_port, |
3331 | .put_port = inet_put_port, |
3332 | #ifdef CONFIG_BPF_SYSCALL |
3333 | .psock_update_sk_prot = tcp_bpf_update_proto, |
3334 | #endif |
3335 | .enter_memory_pressure = tcp_enter_memory_pressure, |
3336 | .leave_memory_pressure = tcp_leave_memory_pressure, |
3337 | .stream_memory_free = tcp_stream_memory_free, |
3338 | .sockets_allocated = &tcp_sockets_allocated, |
3339 | .orphan_count = &tcp_orphan_count, |
3340 | |
3341 | .memory_allocated = &tcp_memory_allocated, |
3342 | .per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc, |
3343 | |
3344 | .memory_pressure = &tcp_memory_pressure, |
3345 | .sysctl_mem = sysctl_tcp_mem, |
3346 | .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem), |
3347 | .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem), |
3348 | .max_header = MAX_TCP_HEADER, |
3349 | .obj_size = sizeof(struct tcp_sock), |
3350 | .slab_flags = SLAB_TYPESAFE_BY_RCU, |
3351 | .twsk_prot = &tcp_timewait_sock_ops, |
3352 | .rsk_prot = &tcp_request_sock_ops, |
3353 | .h.hashinfo = NULL, |
3354 | .no_autobind = true, |
3355 | .diag_destroy = tcp_abort, |
3356 | }; |
3357 | EXPORT_SYMBOL(tcp_prot); |
3358 | |
3359 | static void __net_exit tcp_sk_exit(struct net *net) |
3360 | { |
3361 | if (net->ipv4.tcp_congestion_control) |
3362 | bpf_module_put(data: net->ipv4.tcp_congestion_control, |
3363 | owner: net->ipv4.tcp_congestion_control->owner); |
3364 | } |
3365 | |
3366 | static void __net_init tcp_set_hashinfo(struct net *net) |
3367 | { |
3368 | struct inet_hashinfo *hinfo; |
3369 | unsigned int ehash_entries; |
3370 | struct net *old_net; |
3371 | |
3372 | if (net_eq(net1: net, net2: &init_net)) |
3373 | goto fallback; |
3374 | |
3375 | old_net = current->nsproxy->net_ns; |
3376 | ehash_entries = READ_ONCE(old_net->ipv4.sysctl_tcp_child_ehash_entries); |
3377 | if (!ehash_entries) |
3378 | goto fallback; |
3379 | |
3380 | ehash_entries = roundup_pow_of_two(ehash_entries); |
3381 | hinfo = inet_pernet_hashinfo_alloc(hashinfo: &tcp_hashinfo, ehash_entries); |
3382 | if (!hinfo) { |
3383 | pr_warn("Failed to allocate TCP ehash (entries: %u) " |
3384 | "for a netns, fallback to the global one\n" , |
3385 | ehash_entries); |
3386 | fallback: |
3387 | hinfo = &tcp_hashinfo; |
3388 | ehash_entries = tcp_hashinfo.ehash_mask + 1; |
3389 | } |
3390 | |
3391 | net->ipv4.tcp_death_row.hashinfo = hinfo; |
3392 | net->ipv4.tcp_death_row.sysctl_max_tw_buckets = ehash_entries / 2; |
3393 | net->ipv4.sysctl_max_syn_backlog = max(128U, ehash_entries / 128); |
3394 | } |
3395 | |
3396 | static int __net_init tcp_sk_init(struct net *net) |
3397 | { |
3398 | net->ipv4.sysctl_tcp_ecn = 2; |
3399 | net->ipv4.sysctl_tcp_ecn_fallback = 1; |
3400 | |
3401 | net->ipv4.sysctl_tcp_base_mss = TCP_BASE_MSS; |
3402 | net->ipv4.sysctl_tcp_min_snd_mss = TCP_MIN_SND_MSS; |
3403 | net->ipv4.sysctl_tcp_probe_threshold = TCP_PROBE_THRESHOLD; |
3404 | net->ipv4.sysctl_tcp_probe_interval = TCP_PROBE_INTERVAL; |
3405 | net->ipv4.sysctl_tcp_mtu_probe_floor = TCP_MIN_SND_MSS; |
3406 | |
3407 | net->ipv4.sysctl_tcp_keepalive_time = TCP_KEEPALIVE_TIME; |
3408 | net->ipv4.sysctl_tcp_keepalive_probes = TCP_KEEPALIVE_PROBES; |
3409 | net->ipv4.sysctl_tcp_keepalive_intvl = TCP_KEEPALIVE_INTVL; |
3410 | |
3411 | net->ipv4.sysctl_tcp_syn_retries = TCP_SYN_RETRIES; |
3412 | net->ipv4.sysctl_tcp_synack_retries = TCP_SYNACK_RETRIES; |
3413 | net->ipv4.sysctl_tcp_syncookies = 1; |
3414 | net->ipv4.sysctl_tcp_reordering = TCP_FASTRETRANS_THRESH; |
3415 | net->ipv4.sysctl_tcp_retries1 = TCP_RETR1; |
3416 | net->ipv4.sysctl_tcp_retries2 = TCP_RETR2; |
3417 | net->ipv4.sysctl_tcp_orphan_retries = 0; |
3418 | net->ipv4.sysctl_tcp_fin_timeout = TCP_FIN_TIMEOUT; |
3419 | net->ipv4.sysctl_tcp_notsent_lowat = UINT_MAX; |
3420 | net->ipv4.sysctl_tcp_tw_reuse = 2; |
3421 | net->ipv4.sysctl_tcp_no_ssthresh_metrics_save = 1; |
3422 | |
3423 | refcount_set(r: &net->ipv4.tcp_death_row.tw_refcount, n: 1); |
3424 | tcp_set_hashinfo(net); |
3425 | |
3426 | net->ipv4.sysctl_tcp_sack = 1; |
3427 | net->ipv4.sysctl_tcp_window_scaling = 1; |
3428 | net->ipv4.sysctl_tcp_timestamps = 1; |
3429 | net->ipv4.sysctl_tcp_early_retrans = 3; |
3430 | net->ipv4.sysctl_tcp_recovery = TCP_RACK_LOSS_DETECTION; |
3431 | net->ipv4.sysctl_tcp_slow_start_after_idle = 1; /* By default, RFC2861 behavior. */ |
3432 | net->ipv4.sysctl_tcp_retrans_collapse = 1; |
3433 | net->ipv4.sysctl_tcp_max_reordering = 300; |
3434 | net->ipv4.sysctl_tcp_dsack = 1; |
3435 | net->ipv4.sysctl_tcp_app_win = 31; |
3436 | net->ipv4.sysctl_tcp_adv_win_scale = 1; |
3437 | net->ipv4.sysctl_tcp_frto = 2; |
3438 | net->ipv4.sysctl_tcp_moderate_rcvbuf = 1; |
3439 | /* This limits the percentage of the congestion window which we |
3440 | * will allow a single TSO frame to consume. Building TSO frames |
3441 | * which are too large can cause TCP streams to be bursty. |
3442 | */ |
3443 | net->ipv4.sysctl_tcp_tso_win_divisor = 3; |
3444 | /* Default TSQ limit of 16 TSO segments */ |
3445 | net->ipv4.sysctl_tcp_limit_output_bytes = 16 * 65536; |
3446 | |
3447 | /* rfc5961 challenge ack rate limiting, per net-ns, disabled by default. */ |
3448 | net->ipv4.sysctl_tcp_challenge_ack_limit = INT_MAX; |
3449 | |
3450 | net->ipv4.sysctl_tcp_min_tso_segs = 2; |
3451 | net->ipv4.sysctl_tcp_tso_rtt_log = 9; /* 2^9 = 512 usec */ |
3452 | net->ipv4.sysctl_tcp_min_rtt_wlen = 300; |
3453 | net->ipv4.sysctl_tcp_autocorking = 1; |
3454 | net->ipv4.sysctl_tcp_invalid_ratelimit = HZ/2; |
3455 | net->ipv4.sysctl_tcp_pacing_ss_ratio = 200; |
3456 | net->ipv4.sysctl_tcp_pacing_ca_ratio = 120; |
3457 | if (net != &init_net) { |
3458 | memcpy(net->ipv4.sysctl_tcp_rmem, |
3459 | init_net.ipv4.sysctl_tcp_rmem, |
3460 | sizeof(init_net.ipv4.sysctl_tcp_rmem)); |
3461 | memcpy(net->ipv4.sysctl_tcp_wmem, |
3462 | init_net.ipv4.sysctl_tcp_wmem, |
3463 | sizeof(init_net.ipv4.sysctl_tcp_wmem)); |
3464 | } |
3465 | net->ipv4.sysctl_tcp_comp_sack_delay_ns = NSEC_PER_MSEC; |
3466 | net->ipv4.sysctl_tcp_comp_sack_slack_ns = 100 * NSEC_PER_USEC; |
3467 | net->ipv4.sysctl_tcp_comp_sack_nr = 44; |
3468 | net->ipv4.sysctl_tcp_backlog_ack_defer = 1; |
3469 | net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE; |
3470 | net->ipv4.sysctl_tcp_fastopen_blackhole_timeout = 0; |
3471 | atomic_set(v: &net->ipv4.tfo_active_disable_times, i: 0); |
3472 | |
3473 | /* Set default values for PLB */ |
3474 | net->ipv4.sysctl_tcp_plb_enabled = 0; /* Disabled by default */ |
3475 | net->ipv4.sysctl_tcp_plb_idle_rehash_rounds = 3; |
3476 | net->ipv4.sysctl_tcp_plb_rehash_rounds = 12; |
3477 | net->ipv4.sysctl_tcp_plb_suspend_rto_sec = 60; |
3478 | /* Default congestion threshold for PLB to mark a round is 50% */ |
3479 | net->ipv4.sysctl_tcp_plb_cong_thresh = (1 << TCP_PLB_SCALE) / 2; |
3480 | |
3481 | /* Reno is always built in */ |
3482 | if (!net_eq(net1: net, net2: &init_net) && |
3483 | bpf_try_module_get(data: init_net.ipv4.tcp_congestion_control, |
3484 | owner: init_net.ipv4.tcp_congestion_control->owner)) |
3485 | net->ipv4.tcp_congestion_control = init_net.ipv4.tcp_congestion_control; |
3486 | else |
3487 | net->ipv4.tcp_congestion_control = &tcp_reno; |
3488 | |
3489 | net->ipv4.sysctl_tcp_syn_linear_timeouts = 4; |
3490 | net->ipv4.sysctl_tcp_shrink_window = 0; |
3491 | |
3492 | net->ipv4.sysctl_tcp_pingpong_thresh = 1; |
3493 | |
3494 | return 0; |
3495 | } |
3496 | |
3497 | static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list) |
3498 | { |
3499 | struct net *net; |
3500 | |
3501 | tcp_twsk_purge(net_exit_list, AF_INET); |
3502 | |
3503 | list_for_each_entry(net, net_exit_list, exit_list) { |
3504 | inet_pernet_hashinfo_free(hashinfo: net->ipv4.tcp_death_row.hashinfo); |
3505 | WARN_ON_ONCE(!refcount_dec_and_test(&net->ipv4.tcp_death_row.tw_refcount)); |
3506 | tcp_fastopen_ctx_destroy(net); |
3507 | } |
3508 | } |
3509 | |
3510 | static struct pernet_operations __net_initdata tcp_sk_ops = { |
3511 | .init = tcp_sk_init, |
3512 | .exit = tcp_sk_exit, |
3513 | .exit_batch = tcp_sk_exit_batch, |
3514 | }; |
3515 | |
3516 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
3517 | DEFINE_BPF_ITER_FUNC(tcp, struct bpf_iter_meta *meta, |
3518 | struct sock_common *sk_common, uid_t uid) |
3519 | |
3520 | #define INIT_BATCH_SZ 16 |
3521 | |
3522 | static int bpf_iter_init_tcp(void *priv_data, struct bpf_iter_aux_info *aux) |
3523 | { |
3524 | struct bpf_tcp_iter_state *iter = priv_data; |
3525 | int err; |
3526 | |
3527 | err = bpf_iter_init_seq_net(priv_data, aux); |
3528 | if (err) |
3529 | return err; |
3530 | |
3531 | err = bpf_iter_tcp_realloc_batch(iter, INIT_BATCH_SZ); |
3532 | if (err) { |
3533 | bpf_iter_fini_seq_net(priv_data); |
3534 | return err; |
3535 | } |
3536 | |
3537 | return 0; |
3538 | } |
3539 | |
3540 | static void bpf_iter_fini_tcp(void *priv_data) |
3541 | { |
3542 | struct bpf_tcp_iter_state *iter = priv_data; |
3543 | |
3544 | bpf_iter_fini_seq_net(priv_data); |
3545 | kvfree(addr: iter->batch); |
3546 | } |
3547 | |
3548 | static const struct bpf_iter_seq_info tcp_seq_info = { |
3549 | .seq_ops = &bpf_iter_tcp_seq_ops, |
3550 | .init_seq_private = bpf_iter_init_tcp, |
3551 | .fini_seq_private = bpf_iter_fini_tcp, |
3552 | .seq_priv_size = sizeof(struct bpf_tcp_iter_state), |
3553 | }; |
3554 | |
3555 | static const struct bpf_func_proto * |
3556 | bpf_iter_tcp_get_func_proto(enum bpf_func_id func_id, |
3557 | const struct bpf_prog *prog) |
3558 | { |
3559 | switch (func_id) { |
3560 | case BPF_FUNC_setsockopt: |
3561 | return &bpf_sk_setsockopt_proto; |
3562 | case BPF_FUNC_getsockopt: |
3563 | return &bpf_sk_getsockopt_proto; |
3564 | default: |
3565 | return NULL; |
3566 | } |
3567 | } |
3568 | |
3569 | static struct bpf_iter_reg tcp_reg_info = { |
3570 | .target = "tcp" , |
3571 | .ctx_arg_info_size = 1, |
3572 | .ctx_arg_info = { |
3573 | { offsetof(struct bpf_iter__tcp, sk_common), |
3574 | PTR_TO_BTF_ID_OR_NULL | PTR_TRUSTED }, |
3575 | }, |
3576 | .get_func_proto = bpf_iter_tcp_get_func_proto, |
3577 | .seq_info = &tcp_seq_info, |
3578 | }; |
3579 | |
3580 | static void __init bpf_iter_register(void) |
3581 | { |
3582 | tcp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON]; |
3583 | if (bpf_iter_reg_target(reg_info: &tcp_reg_info)) |
3584 | pr_warn("Warning: could not register bpf iterator tcp\n" ); |
3585 | } |
3586 | |
3587 | #endif |
3588 | |
3589 | void __init tcp_v4_init(void) |
3590 | { |
3591 | int cpu, res; |
3592 | |
3593 | for_each_possible_cpu(cpu) { |
3594 | struct sock *sk; |
3595 | |
3596 | res = inet_ctl_sock_create(sk: &sk, PF_INET, type: SOCK_RAW, |
3597 | IPPROTO_TCP, net: &init_net); |
3598 | if (res) |
3599 | panic(fmt: "Failed to create the TCP control socket.\n" ); |
3600 | sock_set_flag(sk, flag: SOCK_USE_WRITE_QUEUE); |
3601 | |
3602 | /* Please enforce IP_DF and IPID==0 for RST and |
3603 | * ACK sent in SYN-RECV and TIME-WAIT state. |
3604 | */ |
3605 | inet_sk(sk)->pmtudisc = IP_PMTUDISC_DO; |
3606 | |
3607 | per_cpu(ipv4_tcp_sk, cpu) = sk; |
3608 | } |
3609 | if (register_pernet_subsys(&tcp_sk_ops)) |
3610 | panic(fmt: "Failed to create the TCP control socket.\n" ); |
3611 | |
3612 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
3613 | bpf_iter_register(); |
3614 | #endif |
3615 | } |
3616 | |