Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
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 | * | |
1da177e4 LT |
9 | * IPv4 specific functions |
10 | * | |
1da177e4 LT |
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 | |
1da177e4 LT |
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 | |
60236fdd | 32 | * request_sock handling and moved |
1da177e4 LT |
33 | * most of it into the af independent code. |
34 | * Added tail drop and some other bugfixes. | |
caa20d9a | 35 | * Added new listen semantics. |
1da177e4 LT |
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 | ||
afd46503 | 48 | #define pr_fmt(fmt) "TCP: " fmt |
1da177e4 | 49 | |
eb4dea58 | 50 | #include <linux/bottom_half.h> |
1da177e4 LT |
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> | |
5a0e3ad6 | 59 | #include <linux/slab.h> |
1da177e4 | 60 | |
457c4cbc | 61 | #include <net/net_namespace.h> |
1da177e4 | 62 | #include <net/icmp.h> |
304a1618 | 63 | #include <net/inet_hashtables.h> |
1da177e4 | 64 | #include <net/tcp.h> |
20380731 | 65 | #include <net/transp_v6.h> |
1da177e4 LT |
66 | #include <net/ipv6.h> |
67 | #include <net/inet_common.h> | |
6d6ee43e | 68 | #include <net/timewait_sock.h> |
1da177e4 | 69 | #include <net/xfrm.h> |
6e5714ea | 70 | #include <net/secure_seq.h> |
076bb0c8 | 71 | #include <net/busy_poll.h> |
1da177e4 LT |
72 | |
73 | #include <linux/inet.h> | |
74 | #include <linux/ipv6.h> | |
75 | #include <linux/stddef.h> | |
76 | #include <linux/proc_fs.h> | |
77 | #include <linux/seq_file.h> | |
6797318e | 78 | #include <linux/inetdevice.h> |
951cf368 | 79 | #include <linux/btf_ids.h> |
1da177e4 | 80 | |
cf80e0e4 | 81 | #include <crypto/hash.h> |
cfb6eeb4 YH |
82 | #include <linux/scatterlist.h> |
83 | ||
c24b14c4 SL |
84 | #include <trace/events/tcp.h> |
85 | ||
cfb6eeb4 | 86 | #ifdef CONFIG_TCP_MD5SIG |
a915da9b | 87 | static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, |
318cf7aa | 88 | __be32 daddr, __be32 saddr, const struct tcphdr *th); |
cfb6eeb4 YH |
89 | #endif |
90 | ||
5caea4ea | 91 | struct inet_hashinfo tcp_hashinfo; |
4bc2f18b | 92 | EXPORT_SYMBOL(tcp_hashinfo); |
1da177e4 | 93 | |
37ba017d ED |
94 | static DEFINE_PER_CPU(struct sock *, ipv4_tcp_sk); |
95 | ||
84b114b9 | 96 | static u32 tcp_v4_init_seq(const struct sk_buff *skb) |
1da177e4 | 97 | { |
84b114b9 ED |
98 | return secure_tcp_seq(ip_hdr(skb)->daddr, |
99 | ip_hdr(skb)->saddr, | |
100 | tcp_hdr(skb)->dest, | |
101 | tcp_hdr(skb)->source); | |
102 | } | |
103 | ||
5d2ed052 | 104 | static u32 tcp_v4_init_ts_off(const struct net *net, const struct sk_buff *skb) |
84b114b9 | 105 | { |
5d2ed052 | 106 | return secure_tcp_ts_off(net, ip_hdr(skb)->daddr, ip_hdr(skb)->saddr); |
1da177e4 LT |
107 | } |
108 | ||
6d6ee43e ACM |
109 | int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) |
110 | { | |
cbfc6495 | 111 | int reuse = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_tw_reuse); |
79e9fed4 | 112 | const struct inet_timewait_sock *tw = inet_twsk(sktw); |
6d6ee43e ACM |
113 | const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw); |
114 | struct tcp_sock *tp = tcp_sk(sk); | |
79e9fed4 MŻ |
115 | |
116 | if (reuse == 2) { | |
117 | /* Still does not detect *everything* that goes through | |
118 | * lo, since we require a loopback src or dst address | |
119 | * or direct binding to 'lo' interface. | |
120 | */ | |
121 | bool loopback = false; | |
122 | if (tw->tw_bound_dev_if == LOOPBACK_IFINDEX) | |
123 | loopback = true; | |
124 | #if IS_ENABLED(CONFIG_IPV6) | |
125 | if (tw->tw_family == AF_INET6) { | |
126 | if (ipv6_addr_loopback(&tw->tw_v6_daddr) || | |
be2644aa | 127 | ipv6_addr_v4mapped_loopback(&tw->tw_v6_daddr) || |
79e9fed4 | 128 | ipv6_addr_loopback(&tw->tw_v6_rcv_saddr) || |
be2644aa | 129 | ipv6_addr_v4mapped_loopback(&tw->tw_v6_rcv_saddr)) |
79e9fed4 MŻ |
130 | loopback = true; |
131 | } else | |
132 | #endif | |
133 | { | |
134 | if (ipv4_is_loopback(tw->tw_daddr) || | |
135 | ipv4_is_loopback(tw->tw_rcv_saddr)) | |
136 | loopback = true; | |
137 | } | |
138 | if (!loopback) | |
139 | reuse = 0; | |
140 | } | |
6d6ee43e ACM |
141 | |
142 | /* With PAWS, it is safe from the viewpoint | |
143 | of data integrity. Even without PAWS it is safe provided sequence | |
144 | spaces do not overlap i.e. at data rates <= 80Mbit/sec. | |
145 | ||
146 | Actually, the idea is close to VJ's one, only timestamp cache is | |
147 | held not per host, but per port pair and TW bucket is used as state | |
148 | holder. | |
149 | ||
150 | If TW bucket has been already destroyed we fall back to VJ's scheme | |
151 | and use initial timestamp retrieved from peer table. | |
152 | */ | |
153 | if (tcptw->tw_ts_recent_stamp && | |
cca9bab1 AB |
154 | (!twp || (reuse && time_after32(ktime_get_seconds(), |
155 | tcptw->tw_ts_recent_stamp)))) { | |
21684dc4 SB |
156 | /* In case of repair and re-using TIME-WAIT sockets we still |
157 | * want to be sure that it is safe as above but honor the | |
158 | * sequence numbers and time stamps set as part of the repair | |
159 | * process. | |
160 | * | |
161 | * Without this check re-using a TIME-WAIT socket with TCP | |
162 | * repair would accumulate a -1 on the repair assigned | |
163 | * sequence number. The first time it is reused the sequence | |
164 | * is -1, the second time -2, etc. This fixes that issue | |
165 | * without appearing to create any others. | |
166 | */ | |
167 | if (likely(!tp->repair)) { | |
0f317464 ED |
168 | u32 seq = tcptw->tw_snd_nxt + 65535 + 2; |
169 | ||
170 | if (!seq) | |
171 | seq = 1; | |
172 | WRITE_ONCE(tp->write_seq, seq); | |
21684dc4 SB |
173 | tp->rx_opt.ts_recent = tcptw->tw_ts_recent; |
174 | tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; | |
175 | } | |
6d6ee43e ACM |
176 | sock_hold(sktw); |
177 | return 1; | |
178 | } | |
179 | ||
180 | return 0; | |
181 | } | |
6d6ee43e ACM |
182 | EXPORT_SYMBOL_GPL(tcp_twsk_unique); |
183 | ||
d74bad4e AI |
184 | static int tcp_v4_pre_connect(struct sock *sk, struct sockaddr *uaddr, |
185 | int addr_len) | |
186 | { | |
187 | /* This check is replicated from tcp_v4_connect() and intended to | |
188 | * prevent BPF program called below from accessing bytes that are out | |
189 | * of the bound specified by user in addr_len. | |
190 | */ | |
191 | if (addr_len < sizeof(struct sockaddr_in)) | |
192 | return -EINVAL; | |
193 | ||
194 | sock_owned_by_me(sk); | |
195 | ||
196 | return BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr); | |
197 | } | |
198 | ||
1da177e4 LT |
199 | /* This will initiate an outgoing connection. */ |
200 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
201 | { | |
2d7192d6 | 202 | struct sockaddr_in *usin = (struct sockaddr_in *)uaddr; |
08eaef90 | 203 | struct inet_timewait_death_row *tcp_death_row; |
1da177e4 LT |
204 | struct inet_sock *inet = inet_sk(sk); |
205 | struct tcp_sock *tp = tcp_sk(sk); | |
08eaef90 KI |
206 | struct ip_options_rcu *inet_opt; |
207 | struct net *net = sock_net(sk); | |
dca8b089 | 208 | __be16 orig_sport, orig_dport; |
8c5dae4c | 209 | __be32 daddr, nexthop; |
da905bd1 | 210 | struct flowi4 *fl4; |
2d7192d6 | 211 | struct rtable *rt; |
1da177e4 LT |
212 | int err; |
213 | ||
214 | if (addr_len < sizeof(struct sockaddr_in)) | |
215 | return -EINVAL; | |
216 | ||
217 | if (usin->sin_family != AF_INET) | |
218 | return -EAFNOSUPPORT; | |
219 | ||
220 | nexthop = daddr = usin->sin_addr.s_addr; | |
f6d8bd05 | 221 | inet_opt = rcu_dereference_protected(inet->inet_opt, |
1e1d04e6 | 222 | lockdep_sock_is_held(sk)); |
f6d8bd05 | 223 | if (inet_opt && inet_opt->opt.srr) { |
1da177e4 LT |
224 | if (!daddr) |
225 | return -EINVAL; | |
f6d8bd05 | 226 | nexthop = inet_opt->opt.faddr; |
1da177e4 LT |
227 | } |
228 | ||
dca8b089 DM |
229 | orig_sport = inet->inet_sport; |
230 | orig_dport = usin->sin_port; | |
da905bd1 DM |
231 | fl4 = &inet->cork.fl.u.ip4; |
232 | rt = ip_route_connect(fl4, nexthop, inet->inet_saddr, | |
67e1e2f4 GN |
233 | sk->sk_bound_dev_if, IPPROTO_TCP, orig_sport, |
234 | orig_dport, sk); | |
b23dd4fe DM |
235 | if (IS_ERR(rt)) { |
236 | err = PTR_ERR(rt); | |
237 | if (err == -ENETUNREACH) | |
08eaef90 | 238 | IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); |
b23dd4fe | 239 | return err; |
584bdf8c | 240 | } |
1da177e4 LT |
241 | |
242 | if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { | |
243 | ip_rt_put(rt); | |
244 | return -ENETUNREACH; | |
245 | } | |
246 | ||
f6d8bd05 | 247 | if (!inet_opt || !inet_opt->opt.srr) |
da905bd1 | 248 | daddr = fl4->daddr; |
1da177e4 | 249 | |
4461568a KI |
250 | tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; |
251 | ||
28044fc1 | 252 | if (!inet->inet_saddr) { |
8c5dae4c | 253 | err = inet_bhash2_update_saddr(sk, &fl4->saddr, AF_INET); |
28044fc1 | 254 | if (err) { |
28044fc1 JK |
255 | ip_rt_put(rt); |
256 | return err; | |
257 | } | |
8c5dae4c KI |
258 | } else { |
259 | sk_rcv_saddr_set(sk, inet->inet_saddr); | |
28044fc1 JK |
260 | } |
261 | ||
c720c7e8 | 262 | if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) { |
1da177e4 LT |
263 | /* Reset inherited state */ |
264 | tp->rx_opt.ts_recent = 0; | |
265 | tp->rx_opt.ts_recent_stamp = 0; | |
ee995283 | 266 | if (likely(!tp->repair)) |
0f317464 | 267 | WRITE_ONCE(tp->write_seq, 0); |
1da177e4 LT |
268 | } |
269 | ||
c720c7e8 | 270 | inet->inet_dport = usin->sin_port; |
d1e559d0 | 271 | sk_daddr_set(sk, daddr); |
1da177e4 | 272 | |
d83d8461 | 273 | inet_csk(sk)->icsk_ext_hdr_len = 0; |
f6d8bd05 ED |
274 | if (inet_opt) |
275 | inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen; | |
1da177e4 | 276 | |
bee7ca9e | 277 | tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT; |
1da177e4 LT |
278 | |
279 | /* Socket identity is still unknown (sport may be zero). | |
280 | * However we set state to SYN-SENT and not releasing socket | |
281 | * lock select source port, enter ourselves into the hash tables and | |
282 | * complete initialization after this. | |
283 | */ | |
284 | tcp_set_state(sk, TCP_SYN_SENT); | |
1946e672 | 285 | err = inet_hash_connect(tcp_death_row, sk); |
1da177e4 LT |
286 | if (err) |
287 | goto failure; | |
288 | ||
877d1f62 | 289 | sk_set_txhash(sk); |
9e7ceb06 | 290 | |
da905bd1 | 291 | rt = ip_route_newports(fl4, rt, orig_sport, orig_dport, |
b23dd4fe DM |
292 | inet->inet_sport, inet->inet_dport, sk); |
293 | if (IS_ERR(rt)) { | |
294 | err = PTR_ERR(rt); | |
295 | rt = NULL; | |
1da177e4 | 296 | goto failure; |
b23dd4fe | 297 | } |
1da177e4 | 298 | /* OK, now commit destination to socket. */ |
bcd76111 | 299 | sk->sk_gso_type = SKB_GSO_TCPV4; |
d8d1f30b | 300 | sk_setup_caps(sk, &rt->dst); |
19f6d3f3 | 301 | rt = NULL; |
1da177e4 | 302 | |
00355fa5 | 303 | if (likely(!tp->repair)) { |
00355fa5 | 304 | if (!tp->write_seq) |
0f317464 ED |
305 | WRITE_ONCE(tp->write_seq, |
306 | secure_tcp_seq(inet->inet_saddr, | |
307 | inet->inet_daddr, | |
308 | inet->inet_sport, | |
309 | usin->sin_port)); | |
08eaef90 | 310 | tp->tsoffset = secure_tcp_ts_off(net, inet->inet_saddr, |
84b114b9 | 311 | inet->inet_daddr); |
00355fa5 | 312 | } |
1da177e4 | 313 | |
7e3cf084 | 314 | inet->inet_id = get_random_u16(); |
1da177e4 | 315 | |
19f6d3f3 WW |
316 | if (tcp_fastopen_defer_connect(sk, &err)) |
317 | return err; | |
318 | if (err) | |
319 | goto failure; | |
320 | ||
2b916477 | 321 | err = tcp_connect(sk); |
ee995283 | 322 | |
1da177e4 LT |
323 | if (err) |
324 | goto failure; | |
325 | ||
326 | return 0; | |
327 | ||
328 | failure: | |
7174259e ACM |
329 | /* |
330 | * This unhashes the socket and releases the local port, | |
331 | * if necessary. | |
332 | */ | |
1da177e4 | 333 | tcp_set_state(sk, TCP_CLOSE); |
e0833d1f | 334 | inet_bhash2_reset_saddr(sk); |
1da177e4 LT |
335 | ip_rt_put(rt); |
336 | sk->sk_route_caps = 0; | |
c720c7e8 | 337 | inet->inet_dport = 0; |
1da177e4 LT |
338 | return err; |
339 | } | |
4bc2f18b | 340 | EXPORT_SYMBOL(tcp_v4_connect); |
1da177e4 | 341 | |
1da177e4 | 342 | /* |
563d34d0 ED |
343 | * This routine reacts to ICMP_FRAG_NEEDED mtu indications as defined in RFC1191. |
344 | * It can be called through tcp_release_cb() if socket was owned by user | |
345 | * at the time tcp_v4_err() was called to handle ICMP message. | |
1da177e4 | 346 | */ |
4fab9071 | 347 | void tcp_v4_mtu_reduced(struct sock *sk) |
1da177e4 | 348 | { |
1da177e4 | 349 | struct inet_sock *inet = inet_sk(sk); |
02b2faaf ED |
350 | struct dst_entry *dst; |
351 | u32 mtu; | |
1da177e4 | 352 | |
02b2faaf ED |
353 | if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) |
354 | return; | |
561022ac | 355 | mtu = READ_ONCE(tcp_sk(sk)->mtu_info); |
80d0a69f DM |
356 | dst = inet_csk_update_pmtu(sk, mtu); |
357 | if (!dst) | |
1da177e4 LT |
358 | return; |
359 | ||
1da177e4 LT |
360 | /* Something is about to be wrong... Remember soft error |
361 | * for the case, if this connection will not able to recover. | |
362 | */ | |
363 | if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst)) | |
364 | sk->sk_err_soft = EMSGSIZE; | |
365 | ||
366 | mtu = dst_mtu(dst); | |
367 | ||
368 | if (inet->pmtudisc != IP_PMTUDISC_DONT && | |
482fc609 | 369 | ip_sk_accept_pmtu(sk) && |
d83d8461 | 370 | inet_csk(sk)->icsk_pmtu_cookie > mtu) { |
1da177e4 LT |
371 | tcp_sync_mss(sk, mtu); |
372 | ||
373 | /* Resend the TCP packet because it's | |
374 | * clear that the old packet has been | |
375 | * dropped. This is the new "fast" path mtu | |
376 | * discovery. | |
377 | */ | |
378 | tcp_simple_retransmit(sk); | |
379 | } /* else let the usual retransmit timer handle it */ | |
380 | } | |
4fab9071 | 381 | EXPORT_SYMBOL(tcp_v4_mtu_reduced); |
1da177e4 | 382 | |
55be7a9c DM |
383 | static void do_redirect(struct sk_buff *skb, struct sock *sk) |
384 | { | |
385 | struct dst_entry *dst = __sk_dst_check(sk, 0); | |
386 | ||
1ed5c48f | 387 | if (dst) |
6700c270 | 388 | dst->ops->redirect(dst, sk, skb); |
55be7a9c DM |
389 | } |
390 | ||
26e37360 ED |
391 | |
392 | /* handle ICMP messages on TCP_NEW_SYN_RECV request sockets */ | |
9cf74903 | 393 | void tcp_req_err(struct sock *sk, u32 seq, bool abort) |
26e37360 ED |
394 | { |
395 | struct request_sock *req = inet_reqsk(sk); | |
396 | struct net *net = sock_net(sk); | |
397 | ||
398 | /* ICMPs are not backlogged, hence we cannot get | |
399 | * an established socket here. | |
400 | */ | |
26e37360 | 401 | if (seq != tcp_rsk(req)->snt_isn) { |
02a1d6e7 | 402 | __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); |
9cf74903 | 403 | } else if (abort) { |
26e37360 ED |
404 | /* |
405 | * Still in SYN_RECV, just remove it silently. | |
406 | * There is no good way to pass the error to the newly | |
407 | * created socket, and POSIX does not want network | |
408 | * errors returned from accept(). | |
409 | */ | |
c6973669 | 410 | inet_csk_reqsk_queue_drop(req->rsk_listener, req); |
9caad864 | 411 | tcp_listendrop(req->rsk_listener); |
26e37360 | 412 | } |
ef84d8ce | 413 | reqsk_put(req); |
26e37360 ED |
414 | } |
415 | EXPORT_SYMBOL(tcp_req_err); | |
416 | ||
f7456642 | 417 | /* TCP-LD (RFC 6069) logic */ |
d2924569 | 418 | void tcp_ld_RTO_revert(struct sock *sk, u32 seq) |
f7456642 ED |
419 | { |
420 | struct inet_connection_sock *icsk = inet_csk(sk); | |
421 | struct tcp_sock *tp = tcp_sk(sk); | |
422 | struct sk_buff *skb; | |
423 | s32 remaining; | |
424 | u32 delta_us; | |
425 | ||
426 | if (sock_owned_by_user(sk)) | |
427 | return; | |
428 | ||
429 | if (seq != tp->snd_una || !icsk->icsk_retransmits || | |
430 | !icsk->icsk_backoff) | |
431 | return; | |
432 | ||
433 | skb = tcp_rtx_queue_head(sk); | |
434 | if (WARN_ON_ONCE(!skb)) | |
435 | return; | |
436 | ||
437 | icsk->icsk_backoff--; | |
438 | icsk->icsk_rto = tp->srtt_us ? __tcp_set_rto(tp) : TCP_TIMEOUT_INIT; | |
439 | icsk->icsk_rto = inet_csk_rto_backoff(icsk, TCP_RTO_MAX); | |
440 | ||
441 | tcp_mstamp_refresh(tp); | |
442 | delta_us = (u32)(tp->tcp_mstamp - tcp_skb_timestamp_us(skb)); | |
443 | remaining = icsk->icsk_rto - usecs_to_jiffies(delta_us); | |
444 | ||
445 | if (remaining > 0) { | |
446 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, | |
447 | remaining, TCP_RTO_MAX); | |
448 | } else { | |
449 | /* RTO revert clocked out retransmission. | |
450 | * Will retransmit now. | |
451 | */ | |
452 | tcp_retransmit_timer(sk); | |
453 | } | |
454 | } | |
d2924569 | 455 | EXPORT_SYMBOL(tcp_ld_RTO_revert); |
f7456642 | 456 | |
1da177e4 LT |
457 | /* |
458 | * This routine is called by the ICMP module when it gets some | |
459 | * sort of error condition. If err < 0 then the socket should | |
460 | * be closed and the error returned to the user. If err > 0 | |
461 | * it's just the icmp type << 8 | icmp code. After adjustment | |
462 | * header points to the first 8 bytes of the tcp header. We need | |
463 | * to find the appropriate port. | |
464 | * | |
465 | * The locking strategy used here is very "optimistic". When | |
466 | * someone else accesses the socket the ICMP is just dropped | |
467 | * and for some paths there is no check at all. | |
468 | * A more general error queue to queue errors for later handling | |
469 | * is probably better. | |
470 | * | |
471 | */ | |
472 | ||
a12daf13 | 473 | int tcp_v4_err(struct sk_buff *skb, u32 info) |
1da177e4 | 474 | { |
a12daf13 ED |
475 | const struct iphdr *iph = (const struct iphdr *)skb->data; |
476 | struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2)); | |
1da177e4 LT |
477 | struct tcp_sock *tp; |
478 | struct inet_sock *inet; | |
a12daf13 ED |
479 | const int type = icmp_hdr(skb)->type; |
480 | const int code = icmp_hdr(skb)->code; | |
1da177e4 | 481 | struct sock *sk; |
0a672f74 | 482 | struct request_sock *fastopen; |
9a568de4 | 483 | u32 seq, snd_una; |
1da177e4 | 484 | int err; |
a12daf13 | 485 | struct net *net = dev_net(skb->dev); |
1da177e4 | 486 | |
4461568a KI |
487 | sk = __inet_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, |
488 | iph->daddr, th->dest, iph->saddr, | |
489 | ntohs(th->source), inet_iif(skb), 0); | |
1da177e4 | 490 | if (!sk) { |
5d3848bc | 491 | __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); |
32bbd879 | 492 | return -ENOENT; |
1da177e4 LT |
493 | } |
494 | if (sk->sk_state == TCP_TIME_WAIT) { | |
9469c7b4 | 495 | inet_twsk_put(inet_twsk(sk)); |
32bbd879 | 496 | return 0; |
1da177e4 | 497 | } |
26e37360 | 498 | seq = ntohl(th->seq); |
32bbd879 SB |
499 | if (sk->sk_state == TCP_NEW_SYN_RECV) { |
500 | tcp_req_err(sk, seq, type == ICMP_PARAMETERPROB || | |
501 | type == ICMP_TIME_EXCEEDED || | |
502 | (type == ICMP_DEST_UNREACH && | |
503 | (code == ICMP_NET_UNREACH || | |
504 | code == ICMP_HOST_UNREACH))); | |
505 | return 0; | |
506 | } | |
1da177e4 LT |
507 | |
508 | bh_lock_sock(sk); | |
509 | /* If too many ICMPs get dropped on busy | |
510 | * servers this needs to be solved differently. | |
563d34d0 ED |
511 | * We do take care of PMTU discovery (RFC1191) special case : |
512 | * we can receive locally generated ICMP messages while socket is held. | |
1da177e4 | 513 | */ |
b74aa930 ED |
514 | if (sock_owned_by_user(sk)) { |
515 | if (!(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)) | |
02a1d6e7 | 516 | __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); |
b74aa930 | 517 | } |
1da177e4 LT |
518 | if (sk->sk_state == TCP_CLOSE) |
519 | goto out; | |
520 | ||
020e71a3 ED |
521 | if (static_branch_unlikely(&ip4_min_ttl)) { |
522 | /* min_ttl can be changed concurrently from do_ip_setsockopt() */ | |
523 | if (unlikely(iph->ttl < READ_ONCE(inet_sk(sk)->min_ttl))) { | |
524 | __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); | |
525 | goto out; | |
526 | } | |
97e3ecd1 | 527 | } |
528 | ||
1da177e4 | 529 | tp = tcp_sk(sk); |
0a672f74 | 530 | /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */ |
d983ea6f | 531 | fastopen = rcu_dereference(tp->fastopen_rsk); |
0a672f74 | 532 | snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una; |
1da177e4 | 533 | if (sk->sk_state != TCP_LISTEN && |
0a672f74 | 534 | !between(seq, snd_una, tp->snd_nxt)) { |
02a1d6e7 | 535 | __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); |
1da177e4 LT |
536 | goto out; |
537 | } | |
538 | ||
539 | switch (type) { | |
55be7a9c | 540 | case ICMP_REDIRECT: |
45caeaa5 | 541 | if (!sock_owned_by_user(sk)) |
a12daf13 | 542 | do_redirect(skb, sk); |
55be7a9c | 543 | goto out; |
1da177e4 LT |
544 | case ICMP_SOURCE_QUENCH: |
545 | /* Just silently ignore these. */ | |
546 | goto out; | |
547 | case ICMP_PARAMETERPROB: | |
548 | err = EPROTO; | |
549 | break; | |
550 | case ICMP_DEST_UNREACH: | |
551 | if (code > NR_ICMP_UNREACH) | |
552 | goto out; | |
553 | ||
554 | if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ | |
0d4f0608 ED |
555 | /* We are not interested in TCP_LISTEN and open_requests |
556 | * (SYN-ACKs send out by Linux are always <576bytes so | |
557 | * they should go through unfragmented). | |
558 | */ | |
559 | if (sk->sk_state == TCP_LISTEN) | |
560 | goto out; | |
561 | ||
561022ac | 562 | WRITE_ONCE(tp->mtu_info, info); |
144d56e9 | 563 | if (!sock_owned_by_user(sk)) { |
563d34d0 | 564 | tcp_v4_mtu_reduced(sk); |
144d56e9 | 565 | } else { |
7aa5470c | 566 | if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, &sk->sk_tsq_flags)) |
144d56e9 ED |
567 | sock_hold(sk); |
568 | } | |
1da177e4 LT |
569 | goto out; |
570 | } | |
571 | ||
572 | err = icmp_err_convert[code].errno; | |
f7456642 ED |
573 | /* check if this ICMP message allows revert of backoff. |
574 | * (see RFC 6069) | |
575 | */ | |
576 | if (!fastopen && | |
577 | (code == ICMP_NET_UNREACH || code == ICMP_HOST_UNREACH)) | |
578 | tcp_ld_RTO_revert(sk, seq); | |
1da177e4 LT |
579 | break; |
580 | case ICMP_TIME_EXCEEDED: | |
581 | err = EHOSTUNREACH; | |
582 | break; | |
583 | default: | |
584 | goto out; | |
585 | } | |
586 | ||
587 | switch (sk->sk_state) { | |
1da177e4 | 588 | case TCP_SYN_SENT: |
0a672f74 YC |
589 | case TCP_SYN_RECV: |
590 | /* Only in fast or simultaneous open. If a fast open socket is | |
2bdcc73c | 591 | * already accepted it is treated as a connected one below. |
0a672f74 | 592 | */ |
51456b29 | 593 | if (fastopen && !fastopen->sk) |
0a672f74 YC |
594 | break; |
595 | ||
a12daf13 | 596 | ip_icmp_error(sk, skb, err, th->dest, info, (u8 *)th); |
45af29ca | 597 | |
1da177e4 | 598 | if (!sock_owned_by_user(sk)) { |
1da177e4 LT |
599 | sk->sk_err = err; |
600 | ||
e3ae2365 | 601 | sk_error_report(sk); |
1da177e4 LT |
602 | |
603 | tcp_done(sk); | |
604 | } else { | |
605 | sk->sk_err_soft = err; | |
606 | } | |
607 | goto out; | |
608 | } | |
609 | ||
610 | /* If we've already connected we will keep trying | |
611 | * until we time out, or the user gives up. | |
612 | * | |
613 | * rfc1122 4.2.3.9 allows to consider as hard errors | |
614 | * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, | |
615 | * but it is obsoleted by pmtu discovery). | |
616 | * | |
617 | * Note, that in modern internet, where routing is unreliable | |
618 | * and in each dark corner broken firewalls sit, sending random | |
619 | * errors ordered by their masters even this two messages finally lose | |
620 | * their original sense (even Linux sends invalid PORT_UNREACHs) | |
621 | * | |
622 | * Now we are in compliance with RFCs. | |
623 | * --ANK (980905) | |
624 | */ | |
625 | ||
626 | inet = inet_sk(sk); | |
627 | if (!sock_owned_by_user(sk) && inet->recverr) { | |
628 | sk->sk_err = err; | |
e3ae2365 | 629 | sk_error_report(sk); |
1da177e4 LT |
630 | } else { /* Only an error on timeout */ |
631 | sk->sk_err_soft = err; | |
632 | } | |
633 | ||
634 | out: | |
635 | bh_unlock_sock(sk); | |
636 | sock_put(sk); | |
32bbd879 | 637 | return 0; |
1da177e4 LT |
638 | } |
639 | ||
28850dc7 | 640 | void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr) |
1da177e4 | 641 | { |
aa8223c7 | 642 | struct tcphdr *th = tcp_hdr(skb); |
1da177e4 | 643 | |
98be9b12 ED |
644 | th->check = ~tcp_v4_check(skb->len, saddr, daddr, 0); |
645 | skb->csum_start = skb_transport_header(skb) - skb->head; | |
646 | skb->csum_offset = offsetof(struct tcphdr, check); | |
1da177e4 LT |
647 | } |
648 | ||
419f9f89 | 649 | /* This routine computes an IPv4 TCP checksum. */ |
bb296246 | 650 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb) |
419f9f89 | 651 | { |
cf533ea5 | 652 | const struct inet_sock *inet = inet_sk(sk); |
419f9f89 HX |
653 | |
654 | __tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr); | |
655 | } | |
4bc2f18b | 656 | EXPORT_SYMBOL(tcp_v4_send_check); |
419f9f89 | 657 | |
1da177e4 LT |
658 | /* |
659 | * This routine will send an RST to the other tcp. | |
660 | * | |
661 | * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.) | |
662 | * for reset. | |
663 | * Answer: if a packet caused RST, it is not for a socket | |
664 | * existing in our system, if it is matched to a socket, | |
665 | * it is just duplicate segment or bug in other side's TCP. | |
666 | * So that we build reply only basing on parameters | |
667 | * arrived with segment. | |
668 | * Exception: precedence violation. We do not implement it in any case. | |
669 | */ | |
670 | ||
dc87efdb FW |
671 | #ifdef CONFIG_TCP_MD5SIG |
672 | #define OPTION_BYTES TCPOLEN_MD5SIG_ALIGNED | |
673 | #else | |
674 | #define OPTION_BYTES sizeof(__be32) | |
675 | #endif | |
676 | ||
a00e7444 | 677 | static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) |
1da177e4 | 678 | { |
cf533ea5 | 679 | const struct tcphdr *th = tcp_hdr(skb); |
cfb6eeb4 YH |
680 | struct { |
681 | struct tcphdr th; | |
dc87efdb | 682 | __be32 opt[OPTION_BYTES / sizeof(__be32)]; |
cfb6eeb4 | 683 | } rep; |
1da177e4 | 684 | struct ip_reply_arg arg; |
cfb6eeb4 | 685 | #ifdef CONFIG_TCP_MD5SIG |
e46787f0 | 686 | struct tcp_md5sig_key *key = NULL; |
658ddaaf SL |
687 | const __u8 *hash_location = NULL; |
688 | unsigned char newhash[16]; | |
689 | int genhash; | |
690 | struct sock *sk1 = NULL; | |
cfb6eeb4 | 691 | #endif |
d6fb396c | 692 | u64 transmit_time = 0; |
00483690 | 693 | struct sock *ctl_sk; |
d6fb396c | 694 | struct net *net; |
1da177e4 LT |
695 | |
696 | /* Never send a reset in response to a reset. */ | |
697 | if (th->rst) | |
698 | return; | |
699 | ||
c3658e8d ED |
700 | /* If sk not NULL, it means we did a successful lookup and incoming |
701 | * route had to be correct. prequeue might have dropped our dst. | |
702 | */ | |
703 | if (!sk && skb_rtable(skb)->rt_type != RTN_LOCAL) | |
1da177e4 LT |
704 | return; |
705 | ||
706 | /* Swap the send and the receive. */ | |
cfb6eeb4 YH |
707 | memset(&rep, 0, sizeof(rep)); |
708 | rep.th.dest = th->source; | |
709 | rep.th.source = th->dest; | |
710 | rep.th.doff = sizeof(struct tcphdr) / 4; | |
711 | rep.th.rst = 1; | |
1da177e4 LT |
712 | |
713 | if (th->ack) { | |
cfb6eeb4 | 714 | rep.th.seq = th->ack_seq; |
1da177e4 | 715 | } else { |
cfb6eeb4 YH |
716 | rep.th.ack = 1; |
717 | rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin + | |
718 | skb->len - (th->doff << 2)); | |
1da177e4 LT |
719 | } |
720 | ||
7174259e | 721 | memset(&arg, 0, sizeof(arg)); |
cfb6eeb4 YH |
722 | arg.iov[0].iov_base = (unsigned char *)&rep; |
723 | arg.iov[0].iov_len = sizeof(rep.th); | |
724 | ||
0f85feae | 725 | net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); |
cfb6eeb4 | 726 | #ifdef CONFIG_TCP_MD5SIG |
3b24d854 | 727 | rcu_read_lock(); |
658ddaaf | 728 | hash_location = tcp_parse_md5sig_option(th); |
271c3b9b | 729 | if (sk && sk_fullsock(sk)) { |
cea97609 | 730 | const union tcp_md5_addr *addr; |
dea53bb8 | 731 | int l3index; |
cea97609 | 732 | |
dea53bb8 DA |
733 | /* sdif set, means packet ingressed via a device |
734 | * in an L3 domain and inet_iif is set to it. | |
735 | */ | |
736 | l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; | |
cea97609 | 737 | addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; |
dea53bb8 | 738 | key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); |
e46787f0 | 739 | } else if (hash_location) { |
cea97609 | 740 | const union tcp_md5_addr *addr; |
534322ca DA |
741 | int sdif = tcp_v4_sdif(skb); |
742 | int dif = inet_iif(skb); | |
dea53bb8 | 743 | int l3index; |
cea97609 | 744 | |
658ddaaf SL |
745 | /* |
746 | * active side is lost. Try to find listening socket through | |
747 | * source port, and then find md5 key through listening socket. | |
748 | * we are not loose security here: | |
749 | * Incoming packet is checked with md5 hash with finding key, | |
750 | * no RST generated if md5 hash doesn't match. | |
751 | */ | |
4461568a KI |
752 | sk1 = __inet_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo, |
753 | NULL, 0, ip_hdr(skb)->saddr, | |
da5e3630 | 754 | th->source, ip_hdr(skb)->daddr, |
534322ca | 755 | ntohs(th->source), dif, sdif); |
658ddaaf SL |
756 | /* don't send rst if it can't find key */ |
757 | if (!sk1) | |
3b24d854 ED |
758 | goto out; |
759 | ||
dea53bb8 DA |
760 | /* sdif set, means packet ingressed via a device |
761 | * in an L3 domain and dif is set to it. | |
762 | */ | |
763 | l3index = sdif ? dif : 0; | |
cea97609 | 764 | addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; |
dea53bb8 | 765 | key = tcp_md5_do_lookup(sk1, l3index, addr, AF_INET); |
658ddaaf | 766 | if (!key) |
3b24d854 ED |
767 | goto out; |
768 | ||
658ddaaf | 769 | |
39f8e58e | 770 | genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb); |
658ddaaf | 771 | if (genhash || memcmp(hash_location, newhash, 16) != 0) |
3b24d854 ED |
772 | goto out; |
773 | ||
658ddaaf SL |
774 | } |
775 | ||
cfb6eeb4 YH |
776 | if (key) { |
777 | rep.opt[0] = htonl((TCPOPT_NOP << 24) | | |
778 | (TCPOPT_NOP << 16) | | |
779 | (TCPOPT_MD5SIG << 8) | | |
780 | TCPOLEN_MD5SIG); | |
781 | /* Update length and the length the header thinks exists */ | |
782 | arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; | |
783 | rep.th.doff = arg.iov[0].iov_len / 4; | |
784 | ||
49a72dfb | 785 | tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1], |
78e645cb IJ |
786 | key, ip_hdr(skb)->saddr, |
787 | ip_hdr(skb)->daddr, &rep.th); | |
cfb6eeb4 YH |
788 | } |
789 | #endif | |
dc87efdb FW |
790 | /* Can't co-exist with TCPMD5, hence check rep.opt[0] */ |
791 | if (rep.opt[0] == 0) { | |
792 | __be32 mrst = mptcp_reset_option(skb); | |
793 | ||
794 | if (mrst) { | |
795 | rep.opt[0] = mrst; | |
796 | arg.iov[0].iov_len += sizeof(mrst); | |
797 | rep.th.doff = arg.iov[0].iov_len / 4; | |
798 | } | |
799 | } | |
800 | ||
eddc9ec5 ACM |
801 | arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, |
802 | ip_hdr(skb)->saddr, /* XXX */ | |
52cd5750 | 803 | arg.iov[0].iov_len, IPPROTO_TCP, 0); |
1da177e4 | 804 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; |
271c3b9b FW |
805 | arg.flags = (sk && inet_sk_transparent(sk)) ? IP_REPLY_ARG_NOSRCCHECK : 0; |
806 | ||
e2446eaa | 807 | /* When socket is gone, all binding information is lost. |
4c675258 AK |
808 | * routing might fail in this case. No choice here, if we choose to force |
809 | * input interface, we will misroute in case of asymmetric route. | |
e2446eaa | 810 | */ |
c24b14c4 | 811 | if (sk) { |
4c675258 | 812 | arg.bound_dev_if = sk->sk_bound_dev_if; |
5c487bb9 SL |
813 | if (sk_fullsock(sk)) |
814 | trace_tcp_send_reset(sk, skb); | |
c24b14c4 | 815 | } |
1da177e4 | 816 | |
271c3b9b FW |
817 | BUILD_BUG_ON(offsetof(struct sock, sk_bound_dev_if) != |
818 | offsetof(struct inet_timewait_sock, tw_bound_dev_if)); | |
819 | ||
66b13d99 | 820 | arg.tos = ip_hdr(skb)->tos; |
e2d118a1 | 821 | arg.uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL); |
47dcc20a | 822 | local_bh_disable(); |
37ba017d ED |
823 | ctl_sk = this_cpu_read(ipv4_tcp_sk); |
824 | sock_net_set(ctl_sk, net); | |
a842fe14 | 825 | if (sk) { |
00483690 JM |
826 | ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ? |
827 | inet_twsk(sk)->tw_mark : sk->sk_mark; | |
f6c0f5d2 ED |
828 | ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ? |
829 | inet_twsk(sk)->tw_priority : sk->sk_priority; | |
d6fb396c | 830 | transmit_time = tcp_transmit_time(sk); |
e22aa148 | 831 | xfrm_sk_clone_policy(ctl_sk, sk); |
a842fe14 | 832 | } |
00483690 | 833 | ip_send_unicast_reply(ctl_sk, |
bdbbb852 | 834 | skb, &TCP_SKB_CB(skb)->header.h4.opt, |
24a2d43d | 835 | ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, |
d6fb396c ED |
836 | &arg, arg.iov[0].iov_len, |
837 | transmit_time); | |
1da177e4 | 838 | |
00483690 | 839 | ctl_sk->sk_mark = 0; |
e22aa148 | 840 | xfrm_sk_free_policy(ctl_sk); |
37ba017d | 841 | sock_net_set(ctl_sk, &init_net); |
90bbcc60 ED |
842 | __TCP_INC_STATS(net, TCP_MIB_OUTSEGS); |
843 | __TCP_INC_STATS(net, TCP_MIB_OUTRSTS); | |
47dcc20a | 844 | local_bh_enable(); |
658ddaaf SL |
845 | |
846 | #ifdef CONFIG_TCP_MD5SIG | |
3b24d854 ED |
847 | out: |
848 | rcu_read_unlock(); | |
658ddaaf | 849 | #endif |
1da177e4 LT |
850 | } |
851 | ||
852 | /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states | |
853 | outside socket context is ugly, certainly. What can I do? | |
854 | */ | |
855 | ||
e2d118a1 | 856 | static void tcp_v4_send_ack(const struct sock *sk, |
e62a123b | 857 | struct sk_buff *skb, u32 seq, u32 ack, |
ee684b6f | 858 | u32 win, u32 tsval, u32 tsecr, int oif, |
88ef4a5a | 859 | struct tcp_md5sig_key *key, |
66b13d99 | 860 | int reply_flags, u8 tos) |
1da177e4 | 861 | { |
cf533ea5 | 862 | const struct tcphdr *th = tcp_hdr(skb); |
1da177e4 LT |
863 | struct { |
864 | struct tcphdr th; | |
714e85be | 865 | __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2) |
cfb6eeb4 | 866 | #ifdef CONFIG_TCP_MD5SIG |
714e85be | 867 | + (TCPOLEN_MD5SIG_ALIGNED >> 2) |
cfb6eeb4 YH |
868 | #endif |
869 | ]; | |
1da177e4 | 870 | } rep; |
e2d118a1 | 871 | struct net *net = sock_net(sk); |
1da177e4 | 872 | struct ip_reply_arg arg; |
00483690 | 873 | struct sock *ctl_sk; |
d6fb396c | 874 | u64 transmit_time; |
1da177e4 LT |
875 | |
876 | memset(&rep.th, 0, sizeof(struct tcphdr)); | |
7174259e | 877 | memset(&arg, 0, sizeof(arg)); |
1da177e4 LT |
878 | |
879 | arg.iov[0].iov_base = (unsigned char *)&rep; | |
880 | arg.iov[0].iov_len = sizeof(rep.th); | |
ee684b6f | 881 | if (tsecr) { |
cfb6eeb4 YH |
882 | rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
883 | (TCPOPT_TIMESTAMP << 8) | | |
884 | TCPOLEN_TIMESTAMP); | |
ee684b6f AV |
885 | rep.opt[1] = htonl(tsval); |
886 | rep.opt[2] = htonl(tsecr); | |
cb48cfe8 | 887 | arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED; |
1da177e4 LT |
888 | } |
889 | ||
890 | /* Swap the send and the receive. */ | |
891 | rep.th.dest = th->source; | |
892 | rep.th.source = th->dest; | |
893 | rep.th.doff = arg.iov[0].iov_len / 4; | |
894 | rep.th.seq = htonl(seq); | |
895 | rep.th.ack_seq = htonl(ack); | |
896 | rep.th.ack = 1; | |
897 | rep.th.window = htons(win); | |
898 | ||
cfb6eeb4 | 899 | #ifdef CONFIG_TCP_MD5SIG |
cfb6eeb4 | 900 | if (key) { |
ee684b6f | 901 | int offset = (tsecr) ? 3 : 0; |
cfb6eeb4 YH |
902 | |
903 | rep.opt[offset++] = htonl((TCPOPT_NOP << 24) | | |
904 | (TCPOPT_NOP << 16) | | |
905 | (TCPOPT_MD5SIG << 8) | | |
906 | TCPOLEN_MD5SIG); | |
907 | arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; | |
908 | rep.th.doff = arg.iov[0].iov_len/4; | |
909 | ||
49a72dfb | 910 | tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset], |
90b7e112 AL |
911 | key, ip_hdr(skb)->saddr, |
912 | ip_hdr(skb)->daddr, &rep.th); | |
cfb6eeb4 YH |
913 | } |
914 | #endif | |
88ef4a5a | 915 | arg.flags = reply_flags; |
eddc9ec5 ACM |
916 | arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, |
917 | ip_hdr(skb)->saddr, /* XXX */ | |
1da177e4 LT |
918 | arg.iov[0].iov_len, IPPROTO_TCP, 0); |
919 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; | |
9501f972 YH |
920 | if (oif) |
921 | arg.bound_dev_if = oif; | |
66b13d99 | 922 | arg.tos = tos; |
e2d118a1 | 923 | arg.uid = sock_net_uid(net, sk_fullsock(sk) ? sk : NULL); |
47dcc20a | 924 | local_bh_disable(); |
37ba017d ED |
925 | ctl_sk = this_cpu_read(ipv4_tcp_sk); |
926 | sock_net_set(ctl_sk, net); | |
a842fe14 ED |
927 | ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ? |
928 | inet_twsk(sk)->tw_mark : sk->sk_mark; | |
f6c0f5d2 ED |
929 | ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ? |
930 | inet_twsk(sk)->tw_priority : sk->sk_priority; | |
d6fb396c | 931 | transmit_time = tcp_transmit_time(sk); |
00483690 | 932 | ip_send_unicast_reply(ctl_sk, |
bdbbb852 | 933 | skb, &TCP_SKB_CB(skb)->header.h4.opt, |
24a2d43d | 934 | ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, |
d6fb396c ED |
935 | &arg, arg.iov[0].iov_len, |
936 | transmit_time); | |
1da177e4 | 937 | |
00483690 | 938 | ctl_sk->sk_mark = 0; |
37ba017d | 939 | sock_net_set(ctl_sk, &init_net); |
90bbcc60 | 940 | __TCP_INC_STATS(net, TCP_MIB_OUTSEGS); |
47dcc20a | 941 | local_bh_enable(); |
1da177e4 LT |
942 | } |
943 | ||
944 | static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) | |
945 | { | |
8feaf0c0 | 946 | struct inet_timewait_sock *tw = inet_twsk(sk); |
cfb6eeb4 | 947 | struct tcp_timewait_sock *tcptw = tcp_twsk(sk); |
1da177e4 | 948 | |
e2d118a1 | 949 | tcp_v4_send_ack(sk, skb, |
e62a123b | 950 | tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, |
7174259e | 951 | tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, |
9a568de4 | 952 | tcp_time_stamp_raw() + tcptw->tw_ts_offset, |
9501f972 YH |
953 | tcptw->tw_ts_recent, |
954 | tw->tw_bound_dev_if, | |
88ef4a5a | 955 | tcp_twsk_md5_key(tcptw), |
66b13d99 ED |
956 | tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0, |
957 | tw->tw_tos | |
9501f972 | 958 | ); |
1da177e4 | 959 | |
8feaf0c0 | 960 | inet_twsk_put(tw); |
1da177e4 LT |
961 | } |
962 | ||
a00e7444 | 963 | static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, |
7174259e | 964 | struct request_sock *req) |
1da177e4 | 965 | { |
cea97609 | 966 | const union tcp_md5_addr *addr; |
dea53bb8 | 967 | int l3index; |
cea97609 | 968 | |
168a8f58 JC |
969 | /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV |
970 | * sk->sk_state == TCP_SYN_RECV -> for Fast Open. | |
971 | */ | |
e62a123b ED |
972 | u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 : |
973 | tcp_sk(sk)->snd_nxt; | |
974 | ||
20a2b49f ED |
975 | /* RFC 7323 2.3 |
976 | * The window field (SEG.WND) of every outgoing segment, with the | |
977 | * exception of <SYN> segments, MUST be right-shifted by | |
978 | * Rcv.Wind.Shift bits: | |
979 | */ | |
cea97609 | 980 | addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; |
dea53bb8 | 981 | l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; |
e2d118a1 | 982 | tcp_v4_send_ack(sk, skb, seq, |
20a2b49f ED |
983 | tcp_rsk(req)->rcv_nxt, |
984 | req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale, | |
9a568de4 | 985 | tcp_time_stamp_raw() + tcp_rsk(req)->ts_off, |
9501f972 YH |
986 | req->ts_recent, |
987 | 0, | |
dea53bb8 | 988 | tcp_md5_do_lookup(sk, l3index, addr, AF_INET), |
66b13d99 ED |
989 | inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0, |
990 | ip_hdr(skb)->tos); | |
1da177e4 LT |
991 | } |
992 | ||
1da177e4 | 993 | /* |
9bf1d83e | 994 | * Send a SYN-ACK after having received a SYN. |
60236fdd | 995 | * This still operates on a request_sock only, not on a big |
1da177e4 LT |
996 | * socket. |
997 | */ | |
0f935dbe | 998 | static int tcp_v4_send_synack(const struct sock *sk, struct dst_entry *dst, |
d6274bd8 | 999 | struct flowi *fl, |
72659ecc | 1000 | struct request_sock *req, |
ca6fb065 | 1001 | struct tcp_fastopen_cookie *foc, |
331fca43 MKL |
1002 | enum tcp_synack_type synack_type, |
1003 | struct sk_buff *syn_skb) | |
1da177e4 | 1004 | { |
2e6599cb | 1005 | const struct inet_request_sock *ireq = inet_rsk(req); |
6bd023f3 | 1006 | struct flowi4 fl4; |
1da177e4 | 1007 | int err = -1; |
d41db5af | 1008 | struct sk_buff *skb; |
ac8f1710 | 1009 | u8 tos; |
1da177e4 LT |
1010 | |
1011 | /* First, grab a route. */ | |
ba3f7f04 | 1012 | if (!dst && (dst = inet_csk_route_req(sk, &fl4, req)) == NULL) |
fd80eb94 | 1013 | return -1; |
1da177e4 | 1014 | |
331fca43 | 1015 | skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb); |
1da177e4 LT |
1016 | |
1017 | if (skb) { | |
634fb979 | 1018 | __tcp_v4_send_check(skb, ireq->ir_loc_addr, ireq->ir_rmt_addr); |
1da177e4 | 1019 | |
870e3a63 | 1020 | tos = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ? |
8ef44b6f WW |
1021 | (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) | |
1022 | (inet_sk(sk)->tos & INET_ECN_MASK) : | |
407c85c7 AD |
1023 | inet_sk(sk)->tos; |
1024 | ||
1025 | if (!INET_ECN_is_capable(tos) && | |
1026 | tcp_bpf_ca_needs_ecn((struct sock *)req)) | |
1027 | tos |= INET_ECN_ECT_0; | |
1028 | ||
2ab2ddd3 | 1029 | rcu_read_lock(); |
634fb979 ED |
1030 | err = ip_build_and_send_pkt(skb, sk, ireq->ir_loc_addr, |
1031 | ireq->ir_rmt_addr, | |
de033b7d | 1032 | rcu_dereference(ireq->ireq_opt), |
861602b5 | 1033 | tos); |
2ab2ddd3 | 1034 | rcu_read_unlock(); |
b9df3cb8 | 1035 | err = net_xmit_eval(err); |
1da177e4 LT |
1036 | } |
1037 | ||
1da177e4 LT |
1038 | return err; |
1039 | } | |
1040 | ||
1041 | /* | |
60236fdd | 1042 | * IPv4 request_sock destructor. |
1da177e4 | 1043 | */ |
60236fdd | 1044 | static void tcp_v4_reqsk_destructor(struct request_sock *req) |
1da177e4 | 1045 | { |
c92e8c02 | 1046 | kfree(rcu_dereference_protected(inet_rsk(req)->ireq_opt, 1)); |
1da177e4 LT |
1047 | } |
1048 | ||
cfb6eeb4 YH |
1049 | #ifdef CONFIG_TCP_MD5SIG |
1050 | /* | |
1051 | * RFC2385 MD5 checksumming requires a mapping of | |
1052 | * IP address->MD5 Key. | |
1053 | * We need to maintain these in the sk structure. | |
1054 | */ | |
1055 | ||
459837b5 | 1056 | DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_md5_needed, HZ); |
6015c71e ED |
1057 | EXPORT_SYMBOL(tcp_md5_needed); |
1058 | ||
86f1e3a8 LC |
1059 | static bool better_md5_match(struct tcp_md5sig_key *old, struct tcp_md5sig_key *new) |
1060 | { | |
1061 | if (!old) | |
1062 | return true; | |
1063 | ||
1064 | /* l3index always overrides non-l3index */ | |
1065 | if (old->l3index && new->l3index == 0) | |
1066 | return false; | |
1067 | if (old->l3index == 0 && new->l3index) | |
1068 | return true; | |
1069 | ||
1070 | return old->prefixlen < new->prefixlen; | |
1071 | } | |
1072 | ||
cfb6eeb4 | 1073 | /* Find the Key structure for an address. */ |
dea53bb8 | 1074 | struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, |
6015c71e ED |
1075 | const union tcp_md5_addr *addr, |
1076 | int family) | |
cfb6eeb4 | 1077 | { |
fd3a154a | 1078 | const struct tcp_sock *tp = tcp_sk(sk); |
a915da9b | 1079 | struct tcp_md5sig_key *key; |
fd3a154a | 1080 | const struct tcp_md5sig_info *md5sig; |
6797318e ID |
1081 | __be32 mask; |
1082 | struct tcp_md5sig_key *best_match = NULL; | |
1083 | bool match; | |
cfb6eeb4 | 1084 | |
a8afca03 ED |
1085 | /* caller either holds rcu_read_lock() or socket lock */ |
1086 | md5sig = rcu_dereference_check(tp->md5sig_info, | |
1e1d04e6 | 1087 | lockdep_sock_is_held(sk)); |
a8afca03 | 1088 | if (!md5sig) |
cfb6eeb4 | 1089 | return NULL; |
083a0326 | 1090 | |
c8b91770 AG |
1091 | hlist_for_each_entry_rcu(key, &md5sig->head, node, |
1092 | lockdep_sock_is_held(sk)) { | |
a915da9b ED |
1093 | if (key->family != family) |
1094 | continue; | |
a76c2315 | 1095 | if (key->flags & TCP_MD5SIG_FLAG_IFINDEX && key->l3index != l3index) |
dea53bb8 | 1096 | continue; |
6797318e ID |
1097 | if (family == AF_INET) { |
1098 | mask = inet_make_mask(key->prefixlen); | |
1099 | match = (key->addr.a4.s_addr & mask) == | |
1100 | (addr->a4.s_addr & mask); | |
1101 | #if IS_ENABLED(CONFIG_IPV6) | |
1102 | } else if (family == AF_INET6) { | |
1103 | match = ipv6_prefix_equal(&key->addr.a6, &addr->a6, | |
1104 | key->prefixlen); | |
1105 | #endif | |
1106 | } else { | |
1107 | match = false; | |
1108 | } | |
1109 | ||
86f1e3a8 | 1110 | if (match && better_md5_match(best_match, key)) |
6797318e ID |
1111 | best_match = key; |
1112 | } | |
1113 | return best_match; | |
1114 | } | |
6015c71e | 1115 | EXPORT_SYMBOL(__tcp_md5_do_lookup); |
6797318e | 1116 | |
e8f37d57 WF |
1117 | static struct tcp_md5sig_key *tcp_md5_do_lookup_exact(const struct sock *sk, |
1118 | const union tcp_md5_addr *addr, | |
dea53bb8 | 1119 | int family, u8 prefixlen, |
a76c2315 | 1120 | int l3index, u8 flags) |
6797318e ID |
1121 | { |
1122 | const struct tcp_sock *tp = tcp_sk(sk); | |
1123 | struct tcp_md5sig_key *key; | |
1124 | unsigned int size = sizeof(struct in_addr); | |
1125 | const struct tcp_md5sig_info *md5sig; | |
1126 | ||
1127 | /* caller either holds rcu_read_lock() or socket lock */ | |
1128 | md5sig = rcu_dereference_check(tp->md5sig_info, | |
1129 | lockdep_sock_is_held(sk)); | |
1130 | if (!md5sig) | |
1131 | return NULL; | |
1132 | #if IS_ENABLED(CONFIG_IPV6) | |
1133 | if (family == AF_INET6) | |
1134 | size = sizeof(struct in6_addr); | |
1135 | #endif | |
c8b91770 AG |
1136 | hlist_for_each_entry_rcu(key, &md5sig->head, node, |
1137 | lockdep_sock_is_held(sk)) { | |
6797318e ID |
1138 | if (key->family != family) |
1139 | continue; | |
a76c2315 LC |
1140 | if ((key->flags & TCP_MD5SIG_FLAG_IFINDEX) != (flags & TCP_MD5SIG_FLAG_IFINDEX)) |
1141 | continue; | |
86f1e3a8 | 1142 | if (key->l3index != l3index) |
dea53bb8 | 1143 | continue; |
6797318e ID |
1144 | if (!memcmp(&key->addr, addr, size) && |
1145 | key->prefixlen == prefixlen) | |
a915da9b | 1146 | return key; |
cfb6eeb4 YH |
1147 | } |
1148 | return NULL; | |
1149 | } | |
1150 | ||
b83e3deb | 1151 | struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, |
fd3a154a | 1152 | const struct sock *addr_sk) |
cfb6eeb4 | 1153 | { |
b52e6921 | 1154 | const union tcp_md5_addr *addr; |
dea53bb8 | 1155 | int l3index; |
a915da9b | 1156 | |
dea53bb8 DA |
1157 | l3index = l3mdev_master_ifindex_by_index(sock_net(sk), |
1158 | addr_sk->sk_bound_dev_if); | |
b52e6921 | 1159 | addr = (const union tcp_md5_addr *)&addr_sk->sk_daddr; |
dea53bb8 | 1160 | return tcp_md5_do_lookup(sk, l3index, addr, AF_INET); |
cfb6eeb4 | 1161 | } |
cfb6eeb4 YH |
1162 | EXPORT_SYMBOL(tcp_v4_md5_lookup); |
1163 | ||
f62c7517 DS |
1164 | static int tcp_md5sig_info_add(struct sock *sk, gfp_t gfp) |
1165 | { | |
1166 | struct tcp_sock *tp = tcp_sk(sk); | |
1167 | struct tcp_md5sig_info *md5sig; | |
1168 | ||
f62c7517 DS |
1169 | md5sig = kmalloc(sizeof(*md5sig), gfp); |
1170 | if (!md5sig) | |
1171 | return -ENOMEM; | |
1172 | ||
1173 | sk_gso_disable(sk); | |
1174 | INIT_HLIST_HEAD(&md5sig->head); | |
1175 | rcu_assign_pointer(tp->md5sig_info, md5sig); | |
1176 | return 0; | |
1177 | } | |
1178 | ||
cfb6eeb4 | 1179 | /* This can be called on a newly created socket, from other files */ |
459837b5 DS |
1180 | static int __tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
1181 | int family, u8 prefixlen, int l3index, u8 flags, | |
1182 | const u8 *newkey, u8 newkeylen, gfp_t gfp) | |
cfb6eeb4 YH |
1183 | { |
1184 | /* Add Key to the list */ | |
b0a713e9 | 1185 | struct tcp_md5sig_key *key; |
cfb6eeb4 | 1186 | struct tcp_sock *tp = tcp_sk(sk); |
a915da9b | 1187 | struct tcp_md5sig_info *md5sig; |
cfb6eeb4 | 1188 | |
a76c2315 | 1189 | key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen, l3index, flags); |
cfb6eeb4 | 1190 | if (key) { |
e6ced831 ED |
1191 | /* Pre-existing entry - just update that one. |
1192 | * Note that the key might be used concurrently. | |
1193 | * data_race() is telling kcsan that we do not care of | |
1194 | * key mismatches, since changing MD5 key on live flows | |
1195 | * can lead to packet drops. | |
1196 | */ | |
1197 | data_race(memcpy(key->key, newkey, newkeylen)); | |
6a2febec | 1198 | |
e6ced831 ED |
1199 | /* Pairs with READ_ONCE() in tcp_md5_hash_key(). |
1200 | * Also note that a reader could catch new key->keylen value | |
1201 | * but old key->key[], this is the reason we use __GFP_ZERO | |
1202 | * at sock_kmalloc() time below these lines. | |
1203 | */ | |
1204 | WRITE_ONCE(key->keylen, newkeylen); | |
6a2febec | 1205 | |
a915da9b ED |
1206 | return 0; |
1207 | } | |
260fcbeb | 1208 | |
a8afca03 | 1209 | md5sig = rcu_dereference_protected(tp->md5sig_info, |
1e1d04e6 | 1210 | lockdep_sock_is_held(sk)); |
cfb6eeb4 | 1211 | |
e6ced831 | 1212 | key = sock_kmalloc(sk, sizeof(*key), gfp | __GFP_ZERO); |
a915da9b ED |
1213 | if (!key) |
1214 | return -ENOMEM; | |
71cea17e | 1215 | if (!tcp_alloc_md5sig_pool()) { |
5f3d9cb2 | 1216 | sock_kfree_s(sk, key, sizeof(*key)); |
a915da9b | 1217 | return -ENOMEM; |
cfb6eeb4 | 1218 | } |
a915da9b ED |
1219 | |
1220 | memcpy(key->key, newkey, newkeylen); | |
1221 | key->keylen = newkeylen; | |
1222 | key->family = family; | |
6797318e | 1223 | key->prefixlen = prefixlen; |
dea53bb8 | 1224 | key->l3index = l3index; |
a76c2315 | 1225 | key->flags = flags; |
a915da9b | 1226 | memcpy(&key->addr, addr, |
3a2cd89b | 1227 | (IS_ENABLED(CONFIG_IPV6) && family == AF_INET6) ? sizeof(struct in6_addr) : |
1228 | sizeof(struct in_addr)); | |
a915da9b | 1229 | hlist_add_head_rcu(&key->node, &md5sig->head); |
cfb6eeb4 YH |
1230 | return 0; |
1231 | } | |
459837b5 DS |
1232 | |
1233 | int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, | |
1234 | int family, u8 prefixlen, int l3index, u8 flags, | |
1235 | const u8 *newkey, u8 newkeylen) | |
1236 | { | |
1237 | struct tcp_sock *tp = tcp_sk(sk); | |
1238 | ||
1239 | if (!rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk))) { | |
1240 | if (tcp_md5sig_info_add(sk, GFP_KERNEL)) | |
1241 | return -ENOMEM; | |
1242 | ||
1243 | if (!static_branch_inc(&tcp_md5_needed.key)) { | |
1244 | struct tcp_md5sig_info *md5sig; | |
1245 | ||
1246 | md5sig = rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk)); | |
1247 | rcu_assign_pointer(tp->md5sig_info, NULL); | |
55fb80d5 | 1248 | kfree_rcu(md5sig, rcu); |
459837b5 DS |
1249 | return -EUSERS; |
1250 | } | |
1251 | } | |
1252 | ||
1253 | return __tcp_md5_do_add(sk, addr, family, prefixlen, l3index, flags, | |
1254 | newkey, newkeylen, GFP_KERNEL); | |
1255 | } | |
a915da9b | 1256 | EXPORT_SYMBOL(tcp_md5_do_add); |
cfb6eeb4 | 1257 | |
459837b5 DS |
1258 | int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr, |
1259 | int family, u8 prefixlen, int l3index, | |
1260 | struct tcp_md5sig_key *key) | |
1261 | { | |
1262 | struct tcp_sock *tp = tcp_sk(sk); | |
1263 | ||
1264 | if (!rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk))) { | |
1265 | if (tcp_md5sig_info_add(sk, sk_gfp_mask(sk, GFP_ATOMIC))) | |
1266 | return -ENOMEM; | |
1267 | ||
1268 | if (!static_key_fast_inc_not_disabled(&tcp_md5_needed.key.key)) { | |
1269 | struct tcp_md5sig_info *md5sig; | |
1270 | ||
1271 | md5sig = rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk)); | |
1272 | net_warn_ratelimited("Too many TCP-MD5 keys in the system\n"); | |
1273 | rcu_assign_pointer(tp->md5sig_info, NULL); | |
55fb80d5 | 1274 | kfree_rcu(md5sig, rcu); |
459837b5 DS |
1275 | return -EUSERS; |
1276 | } | |
1277 | } | |
1278 | ||
1279 | return __tcp_md5_do_add(sk, addr, family, prefixlen, l3index, | |
1280 | key->flags, key->key, key->keylen, | |
1281 | sk_gfp_mask(sk, GFP_ATOMIC)); | |
1282 | } | |
1283 | EXPORT_SYMBOL(tcp_md5_key_copy); | |
1284 | ||
6797318e | 1285 | int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family, |
a76c2315 | 1286 | u8 prefixlen, int l3index, u8 flags) |
cfb6eeb4 | 1287 | { |
a915da9b ED |
1288 | struct tcp_md5sig_key *key; |
1289 | ||
a76c2315 | 1290 | key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen, l3index, flags); |
a915da9b ED |
1291 | if (!key) |
1292 | return -ENOENT; | |
1293 | hlist_del_rcu(&key->node); | |
5f3d9cb2 | 1294 | atomic_sub(sizeof(*key), &sk->sk_omem_alloc); |
a915da9b | 1295 | kfree_rcu(key, rcu); |
a915da9b | 1296 | return 0; |
cfb6eeb4 | 1297 | } |
a915da9b | 1298 | EXPORT_SYMBOL(tcp_md5_do_del); |
cfb6eeb4 | 1299 | |
e0683e70 | 1300 | static void tcp_clear_md5_list(struct sock *sk) |
cfb6eeb4 YH |
1301 | { |
1302 | struct tcp_sock *tp = tcp_sk(sk); | |
a915da9b | 1303 | struct tcp_md5sig_key *key; |
b67bfe0d | 1304 | struct hlist_node *n; |
a8afca03 | 1305 | struct tcp_md5sig_info *md5sig; |
cfb6eeb4 | 1306 | |
a8afca03 ED |
1307 | md5sig = rcu_dereference_protected(tp->md5sig_info, 1); |
1308 | ||
b67bfe0d | 1309 | hlist_for_each_entry_safe(key, n, &md5sig->head, node) { |
a915da9b | 1310 | hlist_del_rcu(&key->node); |
5f3d9cb2 | 1311 | atomic_sub(sizeof(*key), &sk->sk_omem_alloc); |
a915da9b | 1312 | kfree_rcu(key, rcu); |
cfb6eeb4 YH |
1313 | } |
1314 | } | |
1315 | ||
8917a777 | 1316 | static int tcp_v4_parse_md5_keys(struct sock *sk, int optname, |
d4c19c49 | 1317 | sockptr_t optval, int optlen) |
cfb6eeb4 YH |
1318 | { |
1319 | struct tcp_md5sig cmd; | |
1320 | struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr; | |
cea97609 | 1321 | const union tcp_md5_addr *addr; |
8917a777 | 1322 | u8 prefixlen = 32; |
dea53bb8 | 1323 | int l3index = 0; |
a76c2315 | 1324 | u8 flags; |
cfb6eeb4 YH |
1325 | |
1326 | if (optlen < sizeof(cmd)) | |
1327 | return -EINVAL; | |
1328 | ||
d4c19c49 | 1329 | if (copy_from_sockptr(&cmd, optval, sizeof(cmd))) |
cfb6eeb4 YH |
1330 | return -EFAULT; |
1331 | ||
1332 | if (sin->sin_family != AF_INET) | |
1333 | return -EINVAL; | |
1334 | ||
a76c2315 LC |
1335 | flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX; |
1336 | ||
8917a777 ID |
1337 | if (optname == TCP_MD5SIG_EXT && |
1338 | cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) { | |
1339 | prefixlen = cmd.tcpm_prefixlen; | |
1340 | if (prefixlen > 32) | |
1341 | return -EINVAL; | |
1342 | } | |
1343 | ||
a76c2315 | 1344 | if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex && |
6b102db5 DA |
1345 | cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) { |
1346 | struct net_device *dev; | |
1347 | ||
1348 | rcu_read_lock(); | |
1349 | dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex); | |
1350 | if (dev && netif_is_l3_master(dev)) | |
1351 | l3index = dev->ifindex; | |
1352 | ||
1353 | rcu_read_unlock(); | |
1354 | ||
1355 | /* ok to reference set/not set outside of rcu; | |
1356 | * right now device MUST be an L3 master | |
1357 | */ | |
1358 | if (!dev || !l3index) | |
1359 | return -EINVAL; | |
1360 | } | |
1361 | ||
cea97609 DA |
1362 | addr = (union tcp_md5_addr *)&sin->sin_addr.s_addr; |
1363 | ||
64a124ed | 1364 | if (!cmd.tcpm_keylen) |
a76c2315 | 1365 | return tcp_md5_do_del(sk, addr, AF_INET, prefixlen, l3index, flags); |
cfb6eeb4 YH |
1366 | |
1367 | if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) | |
1368 | return -EINVAL; | |
1369 | ||
a76c2315 | 1370 | return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, flags, |
459837b5 | 1371 | cmd.tcpm_key, cmd.tcpm_keylen); |
cfb6eeb4 YH |
1372 | } |
1373 | ||
19689e38 ED |
1374 | static int tcp_v4_md5_hash_headers(struct tcp_md5sig_pool *hp, |
1375 | __be32 daddr, __be32 saddr, | |
1376 | const struct tcphdr *th, int nbytes) | |
cfb6eeb4 | 1377 | { |
cfb6eeb4 | 1378 | struct tcp4_pseudohdr *bp; |
49a72dfb | 1379 | struct scatterlist sg; |
19689e38 | 1380 | struct tcphdr *_th; |
cfb6eeb4 | 1381 | |
19689e38 | 1382 | bp = hp->scratch; |
cfb6eeb4 YH |
1383 | bp->saddr = saddr; |
1384 | bp->daddr = daddr; | |
1385 | bp->pad = 0; | |
076fb722 | 1386 | bp->protocol = IPPROTO_TCP; |
49a72dfb | 1387 | bp->len = cpu_to_be16(nbytes); |
c7da57a1 | 1388 | |
19689e38 ED |
1389 | _th = (struct tcphdr *)(bp + 1); |
1390 | memcpy(_th, th, sizeof(*th)); | |
1391 | _th->check = 0; | |
1392 | ||
1393 | sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th)); | |
1394 | ahash_request_set_crypt(hp->md5_req, &sg, NULL, | |
1395 | sizeof(*bp) + sizeof(*th)); | |
cf80e0e4 | 1396 | return crypto_ahash_update(hp->md5_req); |
49a72dfb AL |
1397 | } |
1398 | ||
a915da9b | 1399 | static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, |
318cf7aa | 1400 | __be32 daddr, __be32 saddr, const struct tcphdr *th) |
49a72dfb AL |
1401 | { |
1402 | struct tcp_md5sig_pool *hp; | |
cf80e0e4 | 1403 | struct ahash_request *req; |
49a72dfb AL |
1404 | |
1405 | hp = tcp_get_md5sig_pool(); | |
1406 | if (!hp) | |
1407 | goto clear_hash_noput; | |
cf80e0e4 | 1408 | req = hp->md5_req; |
49a72dfb | 1409 | |
cf80e0e4 | 1410 | if (crypto_ahash_init(req)) |
49a72dfb | 1411 | goto clear_hash; |
19689e38 | 1412 | if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2)) |
49a72dfb AL |
1413 | goto clear_hash; |
1414 | if (tcp_md5_hash_key(hp, key)) | |
1415 | goto clear_hash; | |
cf80e0e4 HX |
1416 | ahash_request_set_crypt(req, NULL, md5_hash, 0); |
1417 | if (crypto_ahash_final(req)) | |
cfb6eeb4 YH |
1418 | goto clear_hash; |
1419 | ||
cfb6eeb4 | 1420 | tcp_put_md5sig_pool(); |
cfb6eeb4 | 1421 | return 0; |
49a72dfb | 1422 | |
cfb6eeb4 YH |
1423 | clear_hash: |
1424 | tcp_put_md5sig_pool(); | |
1425 | clear_hash_noput: | |
1426 | memset(md5_hash, 0, 16); | |
49a72dfb | 1427 | return 1; |
cfb6eeb4 YH |
1428 | } |
1429 | ||
39f8e58e ED |
1430 | int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, |
1431 | const struct sock *sk, | |
318cf7aa | 1432 | const struct sk_buff *skb) |
cfb6eeb4 | 1433 | { |
49a72dfb | 1434 | struct tcp_md5sig_pool *hp; |
cf80e0e4 | 1435 | struct ahash_request *req; |
318cf7aa | 1436 | const struct tcphdr *th = tcp_hdr(skb); |
cfb6eeb4 YH |
1437 | __be32 saddr, daddr; |
1438 | ||
39f8e58e ED |
1439 | if (sk) { /* valid for establish/request sockets */ |
1440 | saddr = sk->sk_rcv_saddr; | |
1441 | daddr = sk->sk_daddr; | |
cfb6eeb4 | 1442 | } else { |
49a72dfb AL |
1443 | const struct iphdr *iph = ip_hdr(skb); |
1444 | saddr = iph->saddr; | |
1445 | daddr = iph->daddr; | |
cfb6eeb4 | 1446 | } |
49a72dfb AL |
1447 | |
1448 | hp = tcp_get_md5sig_pool(); | |
1449 | if (!hp) | |
1450 | goto clear_hash_noput; | |
cf80e0e4 | 1451 | req = hp->md5_req; |
49a72dfb | 1452 | |
cf80e0e4 | 1453 | if (crypto_ahash_init(req)) |
49a72dfb AL |
1454 | goto clear_hash; |
1455 | ||
19689e38 | 1456 | if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, skb->len)) |
49a72dfb AL |
1457 | goto clear_hash; |
1458 | if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2)) | |
1459 | goto clear_hash; | |
1460 | if (tcp_md5_hash_key(hp, key)) | |
1461 | goto clear_hash; | |
cf80e0e4 HX |
1462 | ahash_request_set_crypt(req, NULL, md5_hash, 0); |
1463 | if (crypto_ahash_final(req)) | |
49a72dfb AL |
1464 | goto clear_hash; |
1465 | ||
1466 | tcp_put_md5sig_pool(); | |
1467 | return 0; | |
1468 | ||
1469 | clear_hash: | |
1470 | tcp_put_md5sig_pool(); | |
1471 | clear_hash_noput: | |
1472 | memset(md5_hash, 0, 16); | |
1473 | return 1; | |
cfb6eeb4 | 1474 | } |
49a72dfb | 1475 | EXPORT_SYMBOL(tcp_v4_md5_hash_skb); |
cfb6eeb4 | 1476 | |
ba8e275a ED |
1477 | #endif |
1478 | ||
b40cf18e ED |
1479 | static void tcp_v4_init_req(struct request_sock *req, |
1480 | const struct sock *sk_listener, | |
16bea70a OP |
1481 | struct sk_buff *skb) |
1482 | { | |
1483 | struct inet_request_sock *ireq = inet_rsk(req); | |
c92e8c02 | 1484 | struct net *net = sock_net(sk_listener); |
16bea70a | 1485 | |
08d2cc3b ED |
1486 | sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr); |
1487 | sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr); | |
c92e8c02 | 1488 | RCU_INIT_POINTER(ireq->ireq_opt, tcp_v4_save_options(net, skb)); |
16bea70a OP |
1489 | } |
1490 | ||
f964629e | 1491 | static struct dst_entry *tcp_v4_route_req(const struct sock *sk, |
7ea851d1 | 1492 | struct sk_buff *skb, |
f964629e | 1493 | struct flowi *fl, |
7ea851d1 | 1494 | struct request_sock *req) |
d94e0417 | 1495 | { |
7ea851d1 FW |
1496 | tcp_v4_init_req(req, sk, skb); |
1497 | ||
1498 | if (security_inet_conn_request(sk, skb, req)) | |
1499 | return NULL; | |
1500 | ||
4396e461 | 1501 | return inet_csk_route_req(sk, &fl->u.ip4, req); |
d94e0417 OP |
1502 | } |
1503 | ||
72a3effa | 1504 | struct request_sock_ops tcp_request_sock_ops __read_mostly = { |
1da177e4 | 1505 | .family = PF_INET, |
2e6599cb | 1506 | .obj_size = sizeof(struct tcp_request_sock), |
5db92c99 | 1507 | .rtx_syn_ack = tcp_rtx_synack, |
60236fdd ACM |
1508 | .send_ack = tcp_v4_reqsk_send_ack, |
1509 | .destructor = tcp_v4_reqsk_destructor, | |
1da177e4 | 1510 | .send_reset = tcp_v4_send_reset, |
688d1945 | 1511 | .syn_ack_timeout = tcp_syn_ack_timeout, |
1da177e4 LT |
1512 | }; |
1513 | ||
35b2c321 | 1514 | const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = { |
2aec4a29 | 1515 | .mss_clamp = TCP_MSS_DEFAULT, |
16bea70a | 1516 | #ifdef CONFIG_TCP_MD5SIG |
fd3a154a | 1517 | .req_md5_lookup = tcp_v4_md5_lookup, |
e3afe7b7 | 1518 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
b6332e6c | 1519 | #endif |
fb7b37a7 OP |
1520 | #ifdef CONFIG_SYN_COOKIES |
1521 | .cookie_init_seq = cookie_v4_init_sequence, | |
1522 | #endif | |
d94e0417 | 1523 | .route_req = tcp_v4_route_req, |
84b114b9 ED |
1524 | .init_seq = tcp_v4_init_seq, |
1525 | .init_ts_off = tcp_v4_init_ts_off, | |
d6274bd8 | 1526 | .send_synack = tcp_v4_send_synack, |
16bea70a | 1527 | }; |
cfb6eeb4 | 1528 | |
1da177e4 LT |
1529 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) |
1530 | { | |
1da177e4 | 1531 | /* Never answer to SYNs send to broadcast or multicast */ |
511c3f92 | 1532 | if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) |
1da177e4 LT |
1533 | goto drop; |
1534 | ||
1fb6f159 OP |
1535 | return tcp_conn_request(&tcp_request_sock_ops, |
1536 | &tcp_request_sock_ipv4_ops, sk, skb); | |
1da177e4 | 1537 | |
1da177e4 | 1538 | drop: |
9caad864 | 1539 | tcp_listendrop(sk); |
1da177e4 LT |
1540 | return 0; |
1541 | } | |
4bc2f18b | 1542 | EXPORT_SYMBOL(tcp_v4_conn_request); |
1da177e4 LT |
1543 | |
1544 | ||
1545 | /* | |
1546 | * The three way handshake has completed - we got a valid synack - | |
1547 | * now create the new socket. | |
1548 | */ | |
0c27171e | 1549 | struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, |
60236fdd | 1550 | struct request_sock *req, |
5e0724d0 ED |
1551 | struct dst_entry *dst, |
1552 | struct request_sock *req_unhash, | |
1553 | bool *own_req) | |
1da177e4 | 1554 | { |
2e6599cb | 1555 | struct inet_request_sock *ireq; |
01770a16 | 1556 | bool found_dup_sk = false; |
1da177e4 LT |
1557 | struct inet_sock *newinet; |
1558 | struct tcp_sock *newtp; | |
1559 | struct sock *newsk; | |
cfb6eeb4 | 1560 | #ifdef CONFIG_TCP_MD5SIG |
cea97609 | 1561 | const union tcp_md5_addr *addr; |
cfb6eeb4 | 1562 | struct tcp_md5sig_key *key; |
dea53bb8 | 1563 | int l3index; |
cfb6eeb4 | 1564 | #endif |
f6d8bd05 | 1565 | struct ip_options_rcu *inet_opt; |
1da177e4 LT |
1566 | |
1567 | if (sk_acceptq_is_full(sk)) | |
1568 | goto exit_overflow; | |
1569 | ||
1da177e4 LT |
1570 | newsk = tcp_create_openreq_child(sk, req, skb); |
1571 | if (!newsk) | |
093d2823 | 1572 | goto exit_nonewsk; |
1da177e4 | 1573 | |
bcd76111 | 1574 | newsk->sk_gso_type = SKB_GSO_TCPV4; |
fae6ef87 | 1575 | inet_sk_rx_dst_set(newsk, skb); |
1da177e4 LT |
1576 | |
1577 | newtp = tcp_sk(newsk); | |
1578 | newinet = inet_sk(newsk); | |
2e6599cb | 1579 | ireq = inet_rsk(req); |
d1e559d0 ED |
1580 | sk_daddr_set(newsk, ireq->ir_rmt_addr); |
1581 | sk_rcv_saddr_set(newsk, ireq->ir_loc_addr); | |
6dd9a14e | 1582 | newsk->sk_bound_dev_if = ireq->ir_iif; |
c92e8c02 ED |
1583 | newinet->inet_saddr = ireq->ir_loc_addr; |
1584 | inet_opt = rcu_dereference(ireq->ireq_opt); | |
1585 | RCU_INIT_POINTER(newinet->inet_opt, inet_opt); | |
463c84b9 | 1586 | newinet->mc_index = inet_iif(skb); |
eddc9ec5 | 1587 | newinet->mc_ttl = ip_hdr(skb)->ttl; |
4c507d28 | 1588 | newinet->rcv_tos = ip_hdr(skb)->tos; |
d83d8461 | 1589 | inet_csk(newsk)->icsk_ext_hdr_len = 0; |
f6d8bd05 ED |
1590 | if (inet_opt) |
1591 | inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen; | |
7e3cf084 | 1592 | newinet->inet_id = get_random_u16(); |
1da177e4 | 1593 | |
8ef44b6f WW |
1594 | /* Set ToS of the new socket based upon the value of incoming SYN. |
1595 | * ECT bits are set later in tcp_init_transfer(). | |
1596 | */ | |
870e3a63 | 1597 | if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)) |
ac8f1710 WW |
1598 | newinet->tos = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK; |
1599 | ||
dfd25fff ED |
1600 | if (!dst) { |
1601 | dst = inet_csk_route_child_sock(sk, newsk, req); | |
1602 | if (!dst) | |
1603 | goto put_and_exit; | |
1604 | } else { | |
1605 | /* syncookie case : see end of cookie_v4_check() */ | |
1606 | } | |
0e734419 DM |
1607 | sk_setup_caps(newsk, dst); |
1608 | ||
81164413 DB |
1609 | tcp_ca_openreq_child(newsk, dst); |
1610 | ||
1da177e4 | 1611 | tcp_sync_mss(newsk, dst_mtu(dst)); |
3541f9e8 | 1612 | newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst)); |
f5fff5dc | 1613 | |
1da177e4 LT |
1614 | tcp_initialize_rcv_mss(newsk); |
1615 | ||
cfb6eeb4 | 1616 | #ifdef CONFIG_TCP_MD5SIG |
dea53bb8 | 1617 | l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif); |
cfb6eeb4 | 1618 | /* Copy over the MD5 key from the original socket */ |
cea97609 | 1619 | addr = (union tcp_md5_addr *)&newinet->inet_daddr; |
dea53bb8 | 1620 | key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); |
00db4124 | 1621 | if (key) { |
b389d1af DS |
1622 | if (tcp_md5_key_copy(newsk, addr, AF_INET, 32, l3index, key)) |
1623 | goto put_and_exit; | |
aba54656 | 1624 | sk_gso_disable(newsk); |
cfb6eeb4 YH |
1625 | } |
1626 | #endif | |
1627 | ||
0e734419 DM |
1628 | if (__inet_inherit_port(sk, newsk) < 0) |
1629 | goto put_and_exit; | |
01770a16 RD |
1630 | *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), |
1631 | &found_dup_sk); | |
c92e8c02 | 1632 | if (likely(*own_req)) { |
49a496c9 | 1633 | tcp_move_syn(newtp, req); |
c92e8c02 ED |
1634 | ireq->ireq_opt = NULL; |
1635 | } else { | |
c89dffc7 KI |
1636 | newinet->inet_opt = NULL; |
1637 | ||
01770a16 RD |
1638 | if (!req_unhash && found_dup_sk) { |
1639 | /* This code path should only be executed in the | |
1640 | * syncookie case only | |
1641 | */ | |
1642 | bh_unlock_sock(newsk); | |
1643 | sock_put(newsk); | |
1644 | newsk = NULL; | |
01770a16 | 1645 | } |
c92e8c02 | 1646 | } |
1da177e4 LT |
1647 | return newsk; |
1648 | ||
1649 | exit_overflow: | |
c10d9310 | 1650 | NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); |
093d2823 BS |
1651 | exit_nonewsk: |
1652 | dst_release(dst); | |
1da177e4 | 1653 | exit: |
9caad864 | 1654 | tcp_listendrop(sk); |
1da177e4 | 1655 | return NULL; |
0e734419 | 1656 | put_and_exit: |
c92e8c02 | 1657 | newinet->inet_opt = NULL; |
e337e24d CP |
1658 | inet_csk_prepare_forced_close(newsk); |
1659 | tcp_done(newsk); | |
0e734419 | 1660 | goto exit; |
1da177e4 | 1661 | } |
4bc2f18b | 1662 | EXPORT_SYMBOL(tcp_v4_syn_recv_sock); |
1da177e4 | 1663 | |
079096f1 | 1664 | static struct sock *tcp_v4_cookie_check(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 1665 | { |
079096f1 | 1666 | #ifdef CONFIG_SYN_COOKIES |
52452c54 | 1667 | const struct tcphdr *th = tcp_hdr(skb); |
1da177e4 | 1668 | |
af9b4738 | 1669 | if (!th->syn) |
461b74c3 | 1670 | sk = cookie_v4_check(sk, skb); |
1da177e4 LT |
1671 | #endif |
1672 | return sk; | |
1673 | } | |
1674 | ||
9349d600 PP |
1675 | u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph, |
1676 | struct tcphdr *th, u32 *cookie) | |
1677 | { | |
1678 | u16 mss = 0; | |
1679 | #ifdef CONFIG_SYN_COOKIES | |
1680 | mss = tcp_get_syncookie_mss(&tcp_request_sock_ops, | |
1681 | &tcp_request_sock_ipv4_ops, sk, th); | |
1682 | if (mss) { | |
1683 | *cookie = __cookie_v4_init_sequence(iph, th, &mss); | |
1684 | tcp_synq_overflow(sk); | |
1685 | } | |
1686 | #endif | |
1687 | return mss; | |
1688 | } | |
1689 | ||
bbd807df BV |
1690 | INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *, |
1691 | u32)); | |
1da177e4 | 1692 | /* The socket must have it's spinlock held when we get |
e994b2f0 | 1693 | * here, unless it is a TCP_LISTEN socket. |
1da177e4 LT |
1694 | * |
1695 | * We have a potential double-lock case here, so even when | |
1696 | * doing backlog processing we use the BH locking scheme. | |
1697 | * This is because we cannot sleep with the original spinlock | |
1698 | * held. | |
1699 | */ | |
1700 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) | |
1701 | { | |
8eba65fa | 1702 | enum skb_drop_reason reason; |
cfb6eeb4 | 1703 | struct sock *rsk; |
cfb6eeb4 | 1704 | |
1da177e4 | 1705 | if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ |
8f905c0e ED |
1706 | struct dst_entry *dst; |
1707 | ||
1708 | dst = rcu_dereference_protected(sk->sk_rx_dst, | |
1709 | lockdep_sock_is_held(sk)); | |
404e0a8b | 1710 | |
bdeab991 | 1711 | sock_rps_save_rxhash(sk, skb); |
3d97379a | 1712 | sk_mark_napi_id(sk, skb); |
404e0a8b | 1713 | if (dst) { |
0c0a5ef8 | 1714 | if (sk->sk_rx_dst_ifindex != skb->skb_iif || |
bbd807df BV |
1715 | !INDIRECT_CALL_1(dst->ops->check, ipv4_dst_check, |
1716 | dst, 0)) { | |
8f905c0e | 1717 | RCU_INIT_POINTER(sk->sk_rx_dst, NULL); |
92101b3b | 1718 | dst_release(dst); |
92101b3b DM |
1719 | } |
1720 | } | |
3d97d88e | 1721 | tcp_rcv_established(sk, skb); |
1da177e4 LT |
1722 | return 0; |
1723 | } | |
1724 | ||
8eba65fa | 1725 | reason = SKB_DROP_REASON_NOT_SPECIFIED; |
12e25e10 | 1726 | if (tcp_checksum_complete(skb)) |
1da177e4 LT |
1727 | goto csum_err; |
1728 | ||
1729 | if (sk->sk_state == TCP_LISTEN) { | |
079096f1 ED |
1730 | struct sock *nsk = tcp_v4_cookie_check(sk, skb); |
1731 | ||
1da177e4 LT |
1732 | if (!nsk) |
1733 | goto discard; | |
1da177e4 | 1734 | if (nsk != sk) { |
cfb6eeb4 YH |
1735 | if (tcp_child_process(sk, nsk, skb)) { |
1736 | rsk = nsk; | |
1da177e4 | 1737 | goto reset; |
cfb6eeb4 | 1738 | } |
1da177e4 LT |
1739 | return 0; |
1740 | } | |
ca55158c | 1741 | } else |
bdeab991 | 1742 | sock_rps_save_rxhash(sk, skb); |
ca55158c | 1743 | |
72ab4a86 | 1744 | if (tcp_rcv_state_process(sk, skb)) { |
cfb6eeb4 | 1745 | rsk = sk; |
1da177e4 | 1746 | goto reset; |
cfb6eeb4 | 1747 | } |
1da177e4 LT |
1748 | return 0; |
1749 | ||
1750 | reset: | |
cfb6eeb4 | 1751 | tcp_v4_send_reset(rsk, skb); |
1da177e4 | 1752 | discard: |
8eba65fa | 1753 | kfree_skb_reason(skb, reason); |
1da177e4 LT |
1754 | /* Be careful here. If this function gets more complicated and |
1755 | * gcc suffers from register pressure on the x86, sk (in %ebx) | |
1756 | * might be destroyed here. This current version compiles correctly, | |
1757 | * but you have been warned. | |
1758 | */ | |
1759 | return 0; | |
1760 | ||
1761 | csum_err: | |
8eba65fa | 1762 | reason = SKB_DROP_REASON_TCP_CSUM; |
709c0314 | 1763 | trace_tcp_bad_csum(skb); |
c10d9310 ED |
1764 | TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); |
1765 | TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); | |
1da177e4 LT |
1766 | goto discard; |
1767 | } | |
4bc2f18b | 1768 | EXPORT_SYMBOL(tcp_v4_do_rcv); |
1da177e4 | 1769 | |
7487449c | 1770 | int tcp_v4_early_demux(struct sk_buff *skb) |
41063e9d | 1771 | { |
4461568a | 1772 | struct net *net = dev_net(skb->dev); |
41063e9d DM |
1773 | const struct iphdr *iph; |
1774 | const struct tcphdr *th; | |
1775 | struct sock *sk; | |
41063e9d | 1776 | |
41063e9d | 1777 | if (skb->pkt_type != PACKET_HOST) |
7487449c | 1778 | return 0; |
41063e9d | 1779 | |
45f00f99 | 1780 | if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr))) |
7487449c | 1781 | return 0; |
41063e9d DM |
1782 | |
1783 | iph = ip_hdr(skb); | |
45f00f99 | 1784 | th = tcp_hdr(skb); |
41063e9d DM |
1785 | |
1786 | if (th->doff < sizeof(struct tcphdr) / 4) | |
7487449c | 1787 | return 0; |
41063e9d | 1788 | |
4461568a | 1789 | sk = __inet_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, |
41063e9d | 1790 | iph->saddr, th->source, |
7011d085 | 1791 | iph->daddr, ntohs(th->dest), |
3fa6f616 | 1792 | skb->skb_iif, inet_sdif(skb)); |
41063e9d DM |
1793 | if (sk) { |
1794 | skb->sk = sk; | |
1795 | skb->destructor = sock_edemux; | |
f7e4eb03 | 1796 | if (sk_fullsock(sk)) { |
8f905c0e | 1797 | struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst); |
505fbcf0 | 1798 | |
41063e9d DM |
1799 | if (dst) |
1800 | dst = dst_check(dst, 0); | |
92101b3b | 1801 | if (dst && |
0c0a5ef8 | 1802 | sk->sk_rx_dst_ifindex == skb->skb_iif) |
92101b3b | 1803 | skb_dst_set_noref(skb, dst); |
41063e9d DM |
1804 | } |
1805 | } | |
7487449c | 1806 | return 0; |
41063e9d DM |
1807 | } |
1808 | ||
7a26dc9e MD |
1809 | bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb, |
1810 | enum skb_drop_reason *reason) | |
c9c33212 | 1811 | { |
d519f350 | 1812 | u32 limit, tail_gso_size, tail_gso_segs; |
4f693b55 ED |
1813 | struct skb_shared_info *shinfo; |
1814 | const struct tcphdr *th; | |
1815 | struct tcphdr *thtail; | |
1816 | struct sk_buff *tail; | |
1817 | unsigned int hdrlen; | |
1818 | bool fragstolen; | |
1819 | u32 gso_segs; | |
b160c285 | 1820 | u32 gso_size; |
4f693b55 | 1821 | int delta; |
c9c33212 ED |
1822 | |
1823 | /* In case all data was pulled from skb frags (in __pskb_pull_tail()), | |
1824 | * we can fix skb->truesize to its real value to avoid future drops. | |
1825 | * This is valid because skb is not yet charged to the socket. | |
1826 | * It has been noticed pure SACK packets were sometimes dropped | |
1827 | * (if cooked by drivers without copybreak feature). | |
1828 | */ | |
60b1af33 | 1829 | skb_condense(skb); |
c9c33212 | 1830 | |
ade9628e ED |
1831 | skb_dst_drop(skb); |
1832 | ||
4f693b55 ED |
1833 | if (unlikely(tcp_checksum_complete(skb))) { |
1834 | bh_unlock_sock(sk); | |
709c0314 | 1835 | trace_tcp_bad_csum(skb); |
7a26dc9e | 1836 | *reason = SKB_DROP_REASON_TCP_CSUM; |
4f693b55 ED |
1837 | __TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); |
1838 | __TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); | |
1839 | return true; | |
1840 | } | |
1841 | ||
1842 | /* Attempt coalescing to last skb in backlog, even if we are | |
1843 | * above the limits. | |
1844 | * This is okay because skb capacity is limited to MAX_SKB_FRAGS. | |
1845 | */ | |
1846 | th = (const struct tcphdr *)skb->data; | |
1847 | hdrlen = th->doff * 4; | |
4f693b55 ED |
1848 | |
1849 | tail = sk->sk_backlog.tail; | |
1850 | if (!tail) | |
1851 | goto no_coalesce; | |
1852 | thtail = (struct tcphdr *)tail->data; | |
1853 | ||
1854 | if (TCP_SKB_CB(tail)->end_seq != TCP_SKB_CB(skb)->seq || | |
1855 | TCP_SKB_CB(tail)->ip_dsfield != TCP_SKB_CB(skb)->ip_dsfield || | |
1856 | ((TCP_SKB_CB(tail)->tcp_flags | | |
ca2fe295 ED |
1857 | TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_SYN | TCPHDR_RST | TCPHDR_URG)) || |
1858 | !((TCP_SKB_CB(tail)->tcp_flags & | |
1859 | TCP_SKB_CB(skb)->tcp_flags) & TCPHDR_ACK) || | |
4f693b55 ED |
1860 | ((TCP_SKB_CB(tail)->tcp_flags ^ |
1861 | TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_ECE | TCPHDR_CWR)) || | |
1862 | #ifdef CONFIG_TLS_DEVICE | |
1863 | tail->decrypted != skb->decrypted || | |
1864 | #endif | |
1865 | thtail->doff != th->doff || | |
1866 | memcmp(thtail + 1, th + 1, hdrlen - sizeof(*th))) | |
1867 | goto no_coalesce; | |
1868 | ||
1869 | __skb_pull(skb, hdrlen); | |
b160c285 ED |
1870 | |
1871 | shinfo = skb_shinfo(skb); | |
1872 | gso_size = shinfo->gso_size ?: skb->len; | |
1873 | gso_segs = shinfo->gso_segs ?: 1; | |
1874 | ||
1875 | shinfo = skb_shinfo(tail); | |
1876 | tail_gso_size = shinfo->gso_size ?: (tail->len - hdrlen); | |
1877 | tail_gso_segs = shinfo->gso_segs ?: 1; | |
1878 | ||
4f693b55 | 1879 | if (skb_try_coalesce(tail, skb, &fragstolen, &delta)) { |
4f693b55 ED |
1880 | TCP_SKB_CB(tail)->end_seq = TCP_SKB_CB(skb)->end_seq; |
1881 | ||
86bccd03 | 1882 | if (likely(!before(TCP_SKB_CB(skb)->ack_seq, TCP_SKB_CB(tail)->ack_seq))) { |
4f693b55 | 1883 | TCP_SKB_CB(tail)->ack_seq = TCP_SKB_CB(skb)->ack_seq; |
86bccd03 ED |
1884 | thtail->window = th->window; |
1885 | } | |
4f693b55 | 1886 | |
ca2fe295 ED |
1887 | /* We have to update both TCP_SKB_CB(tail)->tcp_flags and |
1888 | * thtail->fin, so that the fast path in tcp_rcv_established() | |
1889 | * is not entered if we append a packet with a FIN. | |
1890 | * SYN, RST, URG are not present. | |
1891 | * ACK is set on both packets. | |
1892 | * PSH : we do not really care in TCP stack, | |
1893 | * at least for 'GRO' packets. | |
1894 | */ | |
1895 | thtail->fin |= th->fin; | |
4f693b55 ED |
1896 | TCP_SKB_CB(tail)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags; |
1897 | ||
1898 | if (TCP_SKB_CB(skb)->has_rxtstamp) { | |
1899 | TCP_SKB_CB(tail)->has_rxtstamp = true; | |
1900 | tail->tstamp = skb->tstamp; | |
1901 | skb_hwtstamps(tail)->hwtstamp = skb_hwtstamps(skb)->hwtstamp; | |
1902 | } | |
1903 | ||
1904 | /* Not as strict as GRO. We only need to carry mss max value */ | |
b160c285 ED |
1905 | shinfo->gso_size = max(gso_size, tail_gso_size); |
1906 | shinfo->gso_segs = min_t(u32, gso_segs + tail_gso_segs, 0xFFFF); | |
4f693b55 ED |
1907 | |
1908 | sk->sk_backlog.len += delta; | |
1909 | __NET_INC_STATS(sock_net(sk), | |
1910 | LINUX_MIB_TCPBACKLOGCOALESCE); | |
1911 | kfree_skb_partial(skb, fragstolen); | |
1912 | return false; | |
1913 | } | |
1914 | __skb_push(skb, hdrlen); | |
1915 | ||
1916 | no_coalesce: | |
ec791d81 LW |
1917 | limit = (u32)READ_ONCE(sk->sk_rcvbuf) + (u32)(READ_ONCE(sk->sk_sndbuf) >> 1); |
1918 | ||
4f693b55 ED |
1919 | /* Only socket owner can try to collapse/prune rx queues |
1920 | * to reduce memory overhead, so add a little headroom here. | |
1921 | * Few sockets backlog are possibly concurrently non empty. | |
1922 | */ | |
ec791d81 | 1923 | limit += 64 * 1024; |
4f693b55 | 1924 | |
c9c33212 ED |
1925 | if (unlikely(sk_add_backlog(sk, skb, limit))) { |
1926 | bh_unlock_sock(sk); | |
7a26dc9e | 1927 | *reason = SKB_DROP_REASON_SOCKET_BACKLOG; |
c9c33212 ED |
1928 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPBACKLOGDROP); |
1929 | return true; | |
1930 | } | |
1931 | return false; | |
1932 | } | |
1933 | EXPORT_SYMBOL(tcp_add_backlog); | |
1934 | ||
ac6e7800 ED |
1935 | int tcp_filter(struct sock *sk, struct sk_buff *skb) |
1936 | { | |
1937 | struct tcphdr *th = (struct tcphdr *)skb->data; | |
ac6e7800 | 1938 | |
f2feaefd | 1939 | return sk_filter_trim_cap(sk, skb, th->doff * 4); |
ac6e7800 ED |
1940 | } |
1941 | EXPORT_SYMBOL(tcp_filter); | |
1942 | ||
eeea10b8 ED |
1943 | static void tcp_v4_restore_cb(struct sk_buff *skb) |
1944 | { | |
1945 | memmove(IPCB(skb), &TCP_SKB_CB(skb)->header.h4, | |
1946 | sizeof(struct inet_skb_parm)); | |
1947 | } | |
1948 | ||
1949 | static void tcp_v4_fill_cb(struct sk_buff *skb, const struct iphdr *iph, | |
1950 | const struct tcphdr *th) | |
1951 | { | |
1952 | /* This is tricky : We move IPCB at its correct location into TCP_SKB_CB() | |
1953 | * barrier() makes sure compiler wont play fool^Waliasing games. | |
1954 | */ | |
1955 | memmove(&TCP_SKB_CB(skb)->header.h4, IPCB(skb), | |
1956 | sizeof(struct inet_skb_parm)); | |
1957 | barrier(); | |
1958 | ||
1959 | TCP_SKB_CB(skb)->seq = ntohl(th->seq); | |
1960 | TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + | |
1961 | skb->len - th->doff * 4); | |
1962 | TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); | |
1963 | TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th); | |
1964 | TCP_SKB_CB(skb)->tcp_tw_isn = 0; | |
1965 | TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph); | |
1966 | TCP_SKB_CB(skb)->sacked = 0; | |
1967 | TCP_SKB_CB(skb)->has_rxtstamp = | |
1968 | skb->tstamp || skb_hwtstamps(skb)->hwtstamp; | |
1969 | } | |
1970 | ||
1da177e4 LT |
1971 | /* |
1972 | * From tcp_input.c | |
1973 | */ | |
1974 | ||
1975 | int tcp_v4_rcv(struct sk_buff *skb) | |
1976 | { | |
3b24d854 | 1977 | struct net *net = dev_net(skb->dev); |
643b622b | 1978 | enum skb_drop_reason drop_reason; |
3fa6f616 | 1979 | int sdif = inet_sdif(skb); |
534322ca | 1980 | int dif = inet_iif(skb); |
eddc9ec5 | 1981 | const struct iphdr *iph; |
cf533ea5 | 1982 | const struct tcphdr *th; |
3b24d854 | 1983 | bool refcounted; |
1da177e4 LT |
1984 | struct sock *sk; |
1985 | int ret; | |
1986 | ||
85125597 | 1987 | drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; |
1da177e4 LT |
1988 | if (skb->pkt_type != PACKET_HOST) |
1989 | goto discard_it; | |
1990 | ||
1991 | /* Count it even if it's bad */ | |
90bbcc60 | 1992 | __TCP_INC_STATS(net, TCP_MIB_INSEGS); |
1da177e4 LT |
1993 | |
1994 | if (!pskb_may_pull(skb, sizeof(struct tcphdr))) | |
1995 | goto discard_it; | |
1996 | ||
ea1627c2 | 1997 | th = (const struct tcphdr *)skb->data; |
1da177e4 | 1998 | |
85125597 MD |
1999 | if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) { |
2000 | drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL; | |
1da177e4 | 2001 | goto bad_packet; |
85125597 | 2002 | } |
1da177e4 LT |
2003 | if (!pskb_may_pull(skb, th->doff * 4)) |
2004 | goto discard_it; | |
2005 | ||
2006 | /* An explanation is required here, I think. | |
2007 | * Packet length and doff are validated by header prediction, | |
caa20d9a | 2008 | * provided case of th->doff==0 is eliminated. |
1da177e4 | 2009 | * So, we defer the checks. */ |
ed70fcfc TH |
2010 | |
2011 | if (skb_checksum_init(skb, IPPROTO_TCP, inet_compute_pseudo)) | |
6a5dc9e5 | 2012 | goto csum_error; |
1da177e4 | 2013 | |
ea1627c2 | 2014 | th = (const struct tcphdr *)skb->data; |
eddc9ec5 | 2015 | iph = ip_hdr(skb); |
4bdc3d66 | 2016 | lookup: |
4461568a KI |
2017 | sk = __inet_lookup_skb(net->ipv4.tcp_death_row.hashinfo, |
2018 | skb, __tcp_hdrlen(th), th->source, | |
3fa6f616 | 2019 | th->dest, sdif, &refcounted); |
1da177e4 LT |
2020 | if (!sk) |
2021 | goto no_tcp_socket; | |
2022 | ||
bb134d5d ED |
2023 | process: |
2024 | if (sk->sk_state == TCP_TIME_WAIT) | |
2025 | goto do_time_wait; | |
2026 | ||
079096f1 ED |
2027 | if (sk->sk_state == TCP_NEW_SYN_RECV) { |
2028 | struct request_sock *req = inet_reqsk(sk); | |
e0f9759f | 2029 | bool req_stolen = false; |
7716682c | 2030 | struct sock *nsk; |
079096f1 ED |
2031 | |
2032 | sk = req->rsk_listener; | |
6f0012e3 ED |
2033 | if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) |
2034 | drop_reason = SKB_DROP_REASON_XFRM_POLICY; | |
2035 | else | |
2036 | drop_reason = tcp_inbound_md5_hash(sk, skb, | |
1330b6ef JK |
2037 | &iph->saddr, &iph->daddr, |
2038 | AF_INET, dif, sdif); | |
2039 | if (unlikely(drop_reason)) { | |
e65c332d | 2040 | sk_drops_add(sk, skb); |
72923555 ED |
2041 | reqsk_put(req); |
2042 | goto discard_it; | |
2043 | } | |
4fd44a98 FL |
2044 | if (tcp_checksum_complete(skb)) { |
2045 | reqsk_put(req); | |
2046 | goto csum_error; | |
2047 | } | |
7716682c | 2048 | if (unlikely(sk->sk_state != TCP_LISTEN)) { |
d4f2c86b KI |
2049 | nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb); |
2050 | if (!nsk) { | |
2051 | inet_csk_reqsk_queue_drop_and_put(sk, req); | |
2052 | goto lookup; | |
2053 | } | |
2054 | sk = nsk; | |
2055 | /* reuseport_migrate_sock() has already held one sk_refcnt | |
2056 | * before returning. | |
2057 | */ | |
2058 | } else { | |
2059 | /* We own a reference on the listener, increase it again | |
2060 | * as we might lose it too soon. | |
2061 | */ | |
2062 | sock_hold(sk); | |
4bdc3d66 | 2063 | } |
3b24d854 | 2064 | refcounted = true; |
1f3b359f | 2065 | nsk = NULL; |
eeea10b8 ED |
2066 | if (!tcp_filter(sk, skb)) { |
2067 | th = (const struct tcphdr *)skb->data; | |
2068 | iph = ip_hdr(skb); | |
2069 | tcp_v4_fill_cb(skb, iph, th); | |
e0f9759f | 2070 | nsk = tcp_check_req(sk, skb, req, false, &req_stolen); |
255f9034 MD |
2071 | } else { |
2072 | drop_reason = SKB_DROP_REASON_SOCKET_FILTER; | |
eeea10b8 | 2073 | } |
079096f1 ED |
2074 | if (!nsk) { |
2075 | reqsk_put(req); | |
e0f9759f ED |
2076 | if (req_stolen) { |
2077 | /* Another cpu got exclusive access to req | |
2078 | * and created a full blown socket. | |
2079 | * Try to feed this packet to this socket | |
2080 | * instead of discarding it. | |
2081 | */ | |
2082 | tcp_v4_restore_cb(skb); | |
2083 | sock_put(sk); | |
2084 | goto lookup; | |
2085 | } | |
7716682c | 2086 | goto discard_and_relse; |
079096f1 | 2087 | } |
6f0012e3 | 2088 | nf_reset_ct(skb); |
079096f1 | 2089 | if (nsk == sk) { |
079096f1 | 2090 | reqsk_put(req); |
eeea10b8 | 2091 | tcp_v4_restore_cb(skb); |
079096f1 ED |
2092 | } else if (tcp_child_process(sk, nsk, skb)) { |
2093 | tcp_v4_send_reset(nsk, skb); | |
7716682c | 2094 | goto discard_and_relse; |
079096f1 | 2095 | } else { |
7716682c | 2096 | sock_put(sk); |
079096f1 ED |
2097 | return 0; |
2098 | } | |
2099 | } | |
14834c4f | 2100 | |
020e71a3 ED |
2101 | if (static_branch_unlikely(&ip4_min_ttl)) { |
2102 | /* min_ttl can be changed concurrently from do_ip_setsockopt() */ | |
2103 | if (unlikely(iph->ttl < READ_ONCE(inet_sk(sk)->min_ttl))) { | |
2104 | __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); | |
2105 | goto discard_and_relse; | |
2106 | } | |
6cce09f8 | 2107 | } |
d218d111 | 2108 | |
255f9034 MD |
2109 | if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) { |
2110 | drop_reason = SKB_DROP_REASON_XFRM_POLICY; | |
1da177e4 | 2111 | goto discard_and_relse; |
255f9034 | 2112 | } |
9ea88a15 | 2113 | |
1330b6ef JK |
2114 | drop_reason = tcp_inbound_md5_hash(sk, skb, &iph->saddr, |
2115 | &iph->daddr, AF_INET, dif, sdif); | |
2116 | if (drop_reason) | |
9ea88a15 | 2117 | goto discard_and_relse; |
9ea88a15 | 2118 | |
895b5c9f | 2119 | nf_reset_ct(skb); |
1da177e4 | 2120 | |
85125597 | 2121 | if (tcp_filter(sk, skb)) { |
364df53c | 2122 | drop_reason = SKB_DROP_REASON_SOCKET_FILTER; |
1da177e4 | 2123 | goto discard_and_relse; |
85125597 | 2124 | } |
ac6e7800 ED |
2125 | th = (const struct tcphdr *)skb->data; |
2126 | iph = ip_hdr(skb); | |
eeea10b8 | 2127 | tcp_v4_fill_cb(skb, iph, th); |
1da177e4 LT |
2128 | |
2129 | skb->dev = NULL; | |
2130 | ||
e994b2f0 ED |
2131 | if (sk->sk_state == TCP_LISTEN) { |
2132 | ret = tcp_v4_do_rcv(sk, skb); | |
2133 | goto put_and_return; | |
2134 | } | |
2135 | ||
2136 | sk_incoming_cpu_update(sk); | |
2137 | ||
c6366184 | 2138 | bh_lock_sock_nested(sk); |
a44d6eac | 2139 | tcp_segs_in(tcp_sk(sk), skb); |
1da177e4 LT |
2140 | ret = 0; |
2141 | if (!sock_owned_by_user(sk)) { | |
e7942d06 | 2142 | ret = tcp_v4_do_rcv(sk, skb); |
8b27dae5 | 2143 | } else { |
7a26dc9e | 2144 | if (tcp_add_backlog(sk, skb, &drop_reason)) |
8b27dae5 | 2145 | goto discard_and_relse; |
6b03a53a | 2146 | } |
1da177e4 LT |
2147 | bh_unlock_sock(sk); |
2148 | ||
e994b2f0 | 2149 | put_and_return: |
3b24d854 ED |
2150 | if (refcounted) |
2151 | sock_put(sk); | |
1da177e4 LT |
2152 | |
2153 | return ret; | |
2154 | ||
2155 | no_tcp_socket: | |
85125597 | 2156 | drop_reason = SKB_DROP_REASON_NO_SOCKET; |
1da177e4 LT |
2157 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) |
2158 | goto discard_it; | |
2159 | ||
eeea10b8 ED |
2160 | tcp_v4_fill_cb(skb, iph, th); |
2161 | ||
12e25e10 | 2162 | if (tcp_checksum_complete(skb)) { |
6a5dc9e5 | 2163 | csum_error: |
85125597 | 2164 | drop_reason = SKB_DROP_REASON_TCP_CSUM; |
709c0314 | 2165 | trace_tcp_bad_csum(skb); |
90bbcc60 | 2166 | __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); |
1da177e4 | 2167 | bad_packet: |
90bbcc60 | 2168 | __TCP_INC_STATS(net, TCP_MIB_INERRS); |
1da177e4 | 2169 | } else { |
cfb6eeb4 | 2170 | tcp_v4_send_reset(NULL, skb); |
1da177e4 LT |
2171 | } |
2172 | ||
2173 | discard_it: | |
f8319dfd | 2174 | SKB_DR_OR(drop_reason, NOT_SPECIFIED); |
1da177e4 | 2175 | /* Discard frame. */ |
85125597 | 2176 | kfree_skb_reason(skb, drop_reason); |
e905a9ed | 2177 | return 0; |
1da177e4 LT |
2178 | |
2179 | discard_and_relse: | |
532182cd | 2180 | sk_drops_add(sk, skb); |
3b24d854 ED |
2181 | if (refcounted) |
2182 | sock_put(sk); | |
1da177e4 LT |
2183 | goto discard_it; |
2184 | ||
2185 | do_time_wait: | |
2186 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { | |
255f9034 | 2187 | drop_reason = SKB_DROP_REASON_XFRM_POLICY; |
9469c7b4 | 2188 | inet_twsk_put(inet_twsk(sk)); |
1da177e4 LT |
2189 | goto discard_it; |
2190 | } | |
2191 | ||
eeea10b8 ED |
2192 | tcp_v4_fill_cb(skb, iph, th); |
2193 | ||
6a5dc9e5 ED |
2194 | if (tcp_checksum_complete(skb)) { |
2195 | inet_twsk_put(inet_twsk(sk)); | |
2196 | goto csum_error; | |
1da177e4 | 2197 | } |
9469c7b4 | 2198 | switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { |
1da177e4 | 2199 | case TCP_TW_SYN: { |
4461568a KI |
2200 | struct sock *sk2 = inet_lookup_listener(net, |
2201 | net->ipv4.tcp_death_row.hashinfo, | |
2202 | skb, __tcp_hdrlen(th), | |
da5e3630 | 2203 | iph->saddr, th->source, |
eddc9ec5 | 2204 | iph->daddr, th->dest, |
3fa6f616 DA |
2205 | inet_iif(skb), |
2206 | sdif); | |
1da177e4 | 2207 | if (sk2) { |
dbe7faa4 | 2208 | inet_twsk_deschedule_put(inet_twsk(sk)); |
1da177e4 | 2209 | sk = sk2; |
eeea10b8 | 2210 | tcp_v4_restore_cb(skb); |
3b24d854 | 2211 | refcounted = false; |
1da177e4 LT |
2212 | goto process; |
2213 | } | |
1da177e4 | 2214 | } |
fcfd6dfa | 2215 | /* to ACK */ |
a8eceea8 | 2216 | fallthrough; |
1da177e4 LT |
2217 | case TCP_TW_ACK: |
2218 | tcp_v4_timewait_ack(sk, skb); | |
2219 | break; | |
2220 | case TCP_TW_RST: | |
271c3b9b FW |
2221 | tcp_v4_send_reset(sk, skb); |
2222 | inet_twsk_deschedule_put(inet_twsk(sk)); | |
2223 | goto discard_it; | |
1da177e4 LT |
2224 | case TCP_TW_SUCCESS:; |
2225 | } | |
2226 | goto discard_it; | |
2227 | } | |
2228 | ||
ccb7c410 DM |
2229 | static struct timewait_sock_ops tcp_timewait_sock_ops = { |
2230 | .twsk_obj_size = sizeof(struct tcp_timewait_sock), | |
2231 | .twsk_unique = tcp_twsk_unique, | |
2232 | .twsk_destructor= tcp_twsk_destructor, | |
ccb7c410 | 2233 | }; |
1da177e4 | 2234 | |
63d02d15 | 2235 | void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb) |
5d299f3d ED |
2236 | { |
2237 | struct dst_entry *dst = skb_dst(skb); | |
2238 | ||
5037e9ef | 2239 | if (dst && dst_hold_safe(dst)) { |
8f905c0e | 2240 | rcu_assign_pointer(sk->sk_rx_dst, dst); |
0c0a5ef8 | 2241 | sk->sk_rx_dst_ifindex = skb->skb_iif; |
ca777eff | 2242 | } |
5d299f3d | 2243 | } |
63d02d15 | 2244 | EXPORT_SYMBOL(inet_sk_rx_dst_set); |
5d299f3d | 2245 | |
3b401a81 | 2246 | const struct inet_connection_sock_af_ops ipv4_specific = { |
543d9cfe ACM |
2247 | .queue_xmit = ip_queue_xmit, |
2248 | .send_check = tcp_v4_send_check, | |
2249 | .rebuild_header = inet_sk_rebuild_header, | |
5d299f3d | 2250 | .sk_rx_dst_set = inet_sk_rx_dst_set, |
543d9cfe ACM |
2251 | .conn_request = tcp_v4_conn_request, |
2252 | .syn_recv_sock = tcp_v4_syn_recv_sock, | |
543d9cfe ACM |
2253 | .net_header_len = sizeof(struct iphdr), |
2254 | .setsockopt = ip_setsockopt, | |
2255 | .getsockopt = ip_getsockopt, | |
2256 | .addr2sockaddr = inet_csk_addr2sockaddr, | |
2257 | .sockaddr_len = sizeof(struct sockaddr_in), | |
4fab9071 | 2258 | .mtu_reduced = tcp_v4_mtu_reduced, |
1da177e4 | 2259 | }; |
4bc2f18b | 2260 | EXPORT_SYMBOL(ipv4_specific); |
1da177e4 | 2261 | |
cfb6eeb4 | 2262 | #ifdef CONFIG_TCP_MD5SIG |
b2e4b3de | 2263 | static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = { |
cfb6eeb4 | 2264 | .md5_lookup = tcp_v4_md5_lookup, |
49a72dfb | 2265 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
cfb6eeb4 | 2266 | .md5_parse = tcp_v4_parse_md5_keys, |
cfb6eeb4 | 2267 | }; |
b6332e6c | 2268 | #endif |
cfb6eeb4 | 2269 | |
1da177e4 LT |
2270 | /* NOTE: A lot of things set to zero explicitly by call to |
2271 | * sk_alloc() so need not be done here. | |
2272 | */ | |
2273 | static int tcp_v4_init_sock(struct sock *sk) | |
2274 | { | |
6687e988 | 2275 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 | 2276 | |
900f65d3 | 2277 | tcp_init_sock(sk); |
1da177e4 | 2278 | |
8292a17a | 2279 | icsk->icsk_af_ops = &ipv4_specific; |
900f65d3 | 2280 | |
cfb6eeb4 | 2281 | #ifdef CONFIG_TCP_MD5SIG |
ac807fa8 | 2282 | tcp_sk(sk)->af_specific = &tcp_sock_ipv4_specific; |
cfb6eeb4 | 2283 | #endif |
1da177e4 | 2284 | |
1da177e4 LT |
2285 | return 0; |
2286 | } | |
2287 | ||
7d06b2e0 | 2288 | void tcp_v4_destroy_sock(struct sock *sk) |
1da177e4 LT |
2289 | { |
2290 | struct tcp_sock *tp = tcp_sk(sk); | |
2291 | ||
e1a4aa50 SL |
2292 | trace_tcp_destroy_sock(sk); |
2293 | ||
1da177e4 LT |
2294 | tcp_clear_xmit_timers(sk); |
2295 | ||
6687e988 | 2296 | tcp_cleanup_congestion_control(sk); |
317a76f9 | 2297 | |
734942cc DW |
2298 | tcp_cleanup_ulp(sk); |
2299 | ||
1da177e4 | 2300 | /* Cleanup up the write buffer. */ |
fe067e8a | 2301 | tcp_write_queue_purge(sk); |
1da177e4 | 2302 | |
cf1ef3f0 WW |
2303 | /* Check if we want to disable active TFO */ |
2304 | tcp_fastopen_active_disable_ofo_check(sk); | |
2305 | ||
1da177e4 | 2306 | /* Cleans up our, hopefully empty, out_of_order_queue. */ |
9f5afeae | 2307 | skb_rbtree_purge(&tp->out_of_order_queue); |
1da177e4 | 2308 | |
cfb6eeb4 YH |
2309 | #ifdef CONFIG_TCP_MD5SIG |
2310 | /* Clean up the MD5 key list, if any */ | |
2311 | if (tp->md5sig_info) { | |
a915da9b | 2312 | tcp_clear_md5_list(sk); |
fb7df5e4 | 2313 | kfree_rcu(rcu_dereference_protected(tp->md5sig_info, 1), rcu); |
cfb6eeb4 | 2314 | tp->md5sig_info = NULL; |
459837b5 | 2315 | static_branch_slow_dec_deferred(&tcp_md5_needed); |
cfb6eeb4 YH |
2316 | } |
2317 | #endif | |
1a2449a8 | 2318 | |
1da177e4 | 2319 | /* Clean up a referenced TCP bind bucket. */ |
463c84b9 | 2320 | if (inet_csk(sk)->icsk_bind_hash) |
ab1e0a13 | 2321 | inet_put_port(sk); |
1da177e4 | 2322 | |
d983ea6f | 2323 | BUG_ON(rcu_access_pointer(tp->fastopen_rsk)); |
435cf559 | 2324 | |
cf60af03 YC |
2325 | /* If socket is aborted during connect operation */ |
2326 | tcp_free_fastopen_req(tp); | |
1fba70e5 | 2327 | tcp_fastopen_destroy_cipher(sk); |
cd8ae852 | 2328 | tcp_saved_syn_free(tp); |
cf60af03 | 2329 | |
180d8cd9 | 2330 | sk_sockets_allocated_dec(sk); |
1da177e4 | 2331 | } |
1da177e4 LT |
2332 | EXPORT_SYMBOL(tcp_v4_destroy_sock); |
2333 | ||
2334 | #ifdef CONFIG_PROC_FS | |
2335 | /* Proc filesystem TCP sock list dumping. */ | |
2336 | ||
ad2d6137 MKL |
2337 | static unsigned short seq_file_family(const struct seq_file *seq); |
2338 | ||
2339 | static bool seq_sk_match(struct seq_file *seq, const struct sock *sk) | |
2340 | { | |
2341 | unsigned short family = seq_file_family(seq); | |
2342 | ||
2343 | /* AF_UNSPEC is used as a match all */ | |
2344 | return ((family == AF_UNSPEC || family == sk->sk_family) && | |
2345 | net_eq(sock_net(sk), seq_file_net(seq))); | |
2346 | } | |
2347 | ||
b72acf45 MKL |
2348 | /* Find a non empty bucket (starting from st->bucket) |
2349 | * and return the first sk from it. | |
a8b690f9 | 2350 | */ |
b72acf45 | 2351 | static void *listening_get_first(struct seq_file *seq) |
1da177e4 | 2352 | { |
4461568a | 2353 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
5799de0b | 2354 | struct tcp_iter_state *st = seq->private; |
1da177e4 | 2355 | |
b72acf45 | 2356 | st->offset = 0; |
4461568a | 2357 | for (; st->bucket <= hinfo->lhash2_mask; st->bucket++) { |
05c0b357 | 2358 | struct inet_listen_hashbucket *ilb2; |
cae3873c | 2359 | struct hlist_nulls_node *node; |
b72acf45 | 2360 | struct sock *sk; |
b08d4d3b | 2361 | |
4461568a | 2362 | ilb2 = &hinfo->lhash2[st->bucket]; |
cae3873c | 2363 | if (hlist_nulls_empty(&ilb2->nulls_head)) |
b72acf45 MKL |
2364 | continue; |
2365 | ||
05c0b357 | 2366 | spin_lock(&ilb2->lock); |
cae3873c | 2367 | sk_nulls_for_each(sk, node, &ilb2->nulls_head) { |
b72acf45 MKL |
2368 | if (seq_sk_match(seq, sk)) |
2369 | return sk; | |
2370 | } | |
05c0b357 | 2371 | spin_unlock(&ilb2->lock); |
1da177e4 | 2372 | } |
b72acf45 MKL |
2373 | |
2374 | return NULL; | |
2375 | } | |
2376 | ||
2377 | /* Find the next sk of "cur" within the same bucket (i.e. st->bucket). | |
2378 | * If "cur" is the last one in the st->bucket, | |
2379 | * call listening_get_first() to return the first sk of the next | |
2380 | * non empty bucket. | |
a8b690f9 | 2381 | */ |
1da177e4 LT |
2382 | static void *listening_get_next(struct seq_file *seq, void *cur) |
2383 | { | |
5799de0b | 2384 | struct tcp_iter_state *st = seq->private; |
05c0b357 | 2385 | struct inet_listen_hashbucket *ilb2; |
cae3873c | 2386 | struct hlist_nulls_node *node; |
4461568a | 2387 | struct inet_hashinfo *hinfo; |
3b24d854 | 2388 | struct sock *sk = cur; |
1da177e4 | 2389 | |
1da177e4 | 2390 | ++st->num; |
a8b690f9 | 2391 | ++st->offset; |
1da177e4 | 2392 | |
cae3873c MKL |
2393 | sk = sk_nulls_next(sk); |
2394 | sk_nulls_for_each_from(sk, node) { | |
ad2d6137 | 2395 | if (seq_sk_match(seq, sk)) |
3b24d854 | 2396 | return sk; |
1da177e4 | 2397 | } |
b72acf45 | 2398 | |
4461568a KI |
2399 | hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
2400 | ilb2 = &hinfo->lhash2[st->bucket]; | |
05c0b357 | 2401 | spin_unlock(&ilb2->lock); |
b72acf45 MKL |
2402 | ++st->bucket; |
2403 | return listening_get_first(seq); | |
1da177e4 LT |
2404 | } |
2405 | ||
2406 | static void *listening_get_idx(struct seq_file *seq, loff_t *pos) | |
2407 | { | |
a8b690f9 TH |
2408 | struct tcp_iter_state *st = seq->private; |
2409 | void *rc; | |
2410 | ||
2411 | st->bucket = 0; | |
2412 | st->offset = 0; | |
b72acf45 | 2413 | rc = listening_get_first(seq); |
1da177e4 LT |
2414 | |
2415 | while (rc && *pos) { | |
2416 | rc = listening_get_next(seq, rc); | |
2417 | --*pos; | |
2418 | } | |
2419 | return rc; | |
2420 | } | |
2421 | ||
4461568a KI |
2422 | static inline bool empty_bucket(struct inet_hashinfo *hinfo, |
2423 | const struct tcp_iter_state *st) | |
6eac5604 | 2424 | { |
4461568a | 2425 | return hlist_nulls_empty(&hinfo->ehash[st->bucket].chain); |
6eac5604 AK |
2426 | } |
2427 | ||
a8b690f9 TH |
2428 | /* |
2429 | * Get first established socket starting from bucket given in st->bucket. | |
2430 | * If st->bucket is zero, the very first socket in the hash is returned. | |
2431 | */ | |
1da177e4 LT |
2432 | static void *established_get_first(struct seq_file *seq) |
2433 | { | |
4461568a | 2434 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
5799de0b | 2435 | struct tcp_iter_state *st = seq->private; |
b08d4d3b | 2436 | |
a8b690f9 | 2437 | st->offset = 0; |
4461568a | 2438 | for (; st->bucket <= hinfo->ehash_mask; ++st->bucket) { |
1da177e4 | 2439 | struct sock *sk; |
3ab5aee7 | 2440 | struct hlist_nulls_node *node; |
4461568a | 2441 | spinlock_t *lock = inet_ehash_lockp(hinfo, st->bucket); |
1da177e4 | 2442 | |
6eac5604 | 2443 | /* Lockless fast path for the common case of empty buckets */ |
4461568a | 2444 | if (empty_bucket(hinfo, st)) |
6eac5604 AK |
2445 | continue; |
2446 | ||
9db66bdc | 2447 | spin_lock_bh(lock); |
4461568a | 2448 | sk_nulls_for_each(sk, node, &hinfo->ehash[st->bucket].chain) { |
ad2d6137 MKL |
2449 | if (seq_sk_match(seq, sk)) |
2450 | return sk; | |
1da177e4 | 2451 | } |
9db66bdc | 2452 | spin_unlock_bh(lock); |
1da177e4 | 2453 | } |
ad2d6137 MKL |
2454 | |
2455 | return NULL; | |
1da177e4 LT |
2456 | } |
2457 | ||
2458 | static void *established_get_next(struct seq_file *seq, void *cur) | |
2459 | { | |
4461568a | 2460 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
5799de0b | 2461 | struct tcp_iter_state *st = seq->private; |
08eaef90 KI |
2462 | struct hlist_nulls_node *node; |
2463 | struct sock *sk = cur; | |
b08d4d3b | 2464 | |
1da177e4 | 2465 | ++st->num; |
a8b690f9 | 2466 | ++st->offset; |
1da177e4 | 2467 | |
05dbc7b5 | 2468 | sk = sk_nulls_next(sk); |
1da177e4 | 2469 | |
3ab5aee7 | 2470 | sk_nulls_for_each_from(sk, node) { |
ad2d6137 | 2471 | if (seq_sk_match(seq, sk)) |
05dbc7b5 | 2472 | return sk; |
1da177e4 LT |
2473 | } |
2474 | ||
4461568a | 2475 | spin_unlock_bh(inet_ehash_lockp(hinfo, st->bucket)); |
05dbc7b5 ED |
2476 | ++st->bucket; |
2477 | return established_get_first(seq); | |
1da177e4 LT |
2478 | } |
2479 | ||
2480 | static void *established_get_idx(struct seq_file *seq, loff_t pos) | |
2481 | { | |
a8b690f9 TH |
2482 | struct tcp_iter_state *st = seq->private; |
2483 | void *rc; | |
2484 | ||
2485 | st->bucket = 0; | |
2486 | rc = established_get_first(seq); | |
1da177e4 LT |
2487 | |
2488 | while (rc && pos) { | |
2489 | rc = established_get_next(seq, rc); | |
2490 | --pos; | |
7174259e | 2491 | } |
1da177e4 LT |
2492 | return rc; |
2493 | } | |
2494 | ||
2495 | static void *tcp_get_idx(struct seq_file *seq, loff_t pos) | |
2496 | { | |
2497 | void *rc; | |
5799de0b | 2498 | struct tcp_iter_state *st = seq->private; |
1da177e4 | 2499 | |
1da177e4 LT |
2500 | st->state = TCP_SEQ_STATE_LISTENING; |
2501 | rc = listening_get_idx(seq, &pos); | |
2502 | ||
2503 | if (!rc) { | |
1da177e4 LT |
2504 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2505 | rc = established_get_idx(seq, pos); | |
2506 | } | |
2507 | ||
2508 | return rc; | |
2509 | } | |
2510 | ||
a8b690f9 TH |
2511 | static void *tcp_seek_last_pos(struct seq_file *seq) |
2512 | { | |
4461568a | 2513 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
a8b690f9 | 2514 | struct tcp_iter_state *st = seq->private; |
525e2f9f | 2515 | int bucket = st->bucket; |
a8b690f9 TH |
2516 | int offset = st->offset; |
2517 | int orig_num = st->num; | |
2518 | void *rc = NULL; | |
2519 | ||
2520 | switch (st->state) { | |
a8b690f9 | 2521 | case TCP_SEQ_STATE_LISTENING: |
4461568a | 2522 | if (st->bucket > hinfo->lhash2_mask) |
a8b690f9 | 2523 | break; |
b72acf45 | 2524 | rc = listening_get_first(seq); |
525e2f9f | 2525 | while (offset-- && rc && bucket == st->bucket) |
a8b690f9 TH |
2526 | rc = listening_get_next(seq, rc); |
2527 | if (rc) | |
2528 | break; | |
2529 | st->bucket = 0; | |
05dbc7b5 | 2530 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
a8eceea8 | 2531 | fallthrough; |
a8b690f9 | 2532 | case TCP_SEQ_STATE_ESTABLISHED: |
4461568a | 2533 | if (st->bucket > hinfo->ehash_mask) |
a8b690f9 TH |
2534 | break; |
2535 | rc = established_get_first(seq); | |
525e2f9f | 2536 | while (offset-- && rc && bucket == st->bucket) |
a8b690f9 TH |
2537 | rc = established_get_next(seq, rc); |
2538 | } | |
2539 | ||
2540 | st->num = orig_num; | |
2541 | ||
2542 | return rc; | |
2543 | } | |
2544 | ||
37d849bb | 2545 | void *tcp_seq_start(struct seq_file *seq, loff_t *pos) |
1da177e4 | 2546 | { |
5799de0b | 2547 | struct tcp_iter_state *st = seq->private; |
a8b690f9 TH |
2548 | void *rc; |
2549 | ||
2550 | if (*pos && *pos == st->last_pos) { | |
2551 | rc = tcp_seek_last_pos(seq); | |
2552 | if (rc) | |
2553 | goto out; | |
2554 | } | |
2555 | ||
1da177e4 LT |
2556 | st->state = TCP_SEQ_STATE_LISTENING; |
2557 | st->num = 0; | |
a8b690f9 TH |
2558 | st->bucket = 0; |
2559 | st->offset = 0; | |
2560 | rc = *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
2561 | ||
2562 | out: | |
2563 | st->last_pos = *pos; | |
2564 | return rc; | |
1da177e4 | 2565 | } |
37d849bb | 2566 | EXPORT_SYMBOL(tcp_seq_start); |
1da177e4 | 2567 | |
37d849bb | 2568 | void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
1da177e4 | 2569 | { |
a8b690f9 | 2570 | struct tcp_iter_state *st = seq->private; |
1da177e4 | 2571 | void *rc = NULL; |
1da177e4 LT |
2572 | |
2573 | if (v == SEQ_START_TOKEN) { | |
2574 | rc = tcp_get_idx(seq, 0); | |
2575 | goto out; | |
2576 | } | |
1da177e4 LT |
2577 | |
2578 | switch (st->state) { | |
1da177e4 LT |
2579 | case TCP_SEQ_STATE_LISTENING: |
2580 | rc = listening_get_next(seq, v); | |
2581 | if (!rc) { | |
1da177e4 | 2582 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
a8b690f9 TH |
2583 | st->bucket = 0; |
2584 | st->offset = 0; | |
1da177e4 LT |
2585 | rc = established_get_first(seq); |
2586 | } | |
2587 | break; | |
2588 | case TCP_SEQ_STATE_ESTABLISHED: | |
1da177e4 LT |
2589 | rc = established_get_next(seq, v); |
2590 | break; | |
2591 | } | |
2592 | out: | |
2593 | ++*pos; | |
a8b690f9 | 2594 | st->last_pos = *pos; |
1da177e4 LT |
2595 | return rc; |
2596 | } | |
37d849bb | 2597 | EXPORT_SYMBOL(tcp_seq_next); |
1da177e4 | 2598 | |
37d849bb | 2599 | void tcp_seq_stop(struct seq_file *seq, void *v) |
1da177e4 | 2600 | { |
4461568a | 2601 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
5799de0b | 2602 | struct tcp_iter_state *st = seq->private; |
1da177e4 LT |
2603 | |
2604 | switch (st->state) { | |
1da177e4 LT |
2605 | case TCP_SEQ_STATE_LISTENING: |
2606 | if (v != SEQ_START_TOKEN) | |
4461568a | 2607 | spin_unlock(&hinfo->lhash2[st->bucket].lock); |
1da177e4 | 2608 | break; |
1da177e4 LT |
2609 | case TCP_SEQ_STATE_ESTABLISHED: |
2610 | if (v) | |
4461568a | 2611 | spin_unlock_bh(inet_ehash_lockp(hinfo, st->bucket)); |
1da177e4 LT |
2612 | break; |
2613 | } | |
2614 | } | |
37d849bb | 2615 | EXPORT_SYMBOL(tcp_seq_stop); |
1da177e4 | 2616 | |
d4f06873 | 2617 | static void get_openreq4(const struct request_sock *req, |
aa3a0c8c | 2618 | struct seq_file *f, int i) |
1da177e4 | 2619 | { |
2e6599cb | 2620 | const struct inet_request_sock *ireq = inet_rsk(req); |
fa76ce73 | 2621 | long delta = req->rsk_timer.expires - jiffies; |
1da177e4 | 2622 | |
5e659e4c | 2623 | seq_printf(f, "%4d: %08X:%04X %08X:%04X" |
652586df | 2624 | " %02X %08X:%08X %02X:%08lX %08X %5u %8d %u %d %pK", |
1da177e4 | 2625 | i, |
634fb979 | 2626 | ireq->ir_loc_addr, |
d4f06873 | 2627 | ireq->ir_num, |
634fb979 ED |
2628 | ireq->ir_rmt_addr, |
2629 | ntohs(ireq->ir_rmt_port), | |
1da177e4 LT |
2630 | TCP_SYN_RECV, |
2631 | 0, 0, /* could print option size, but that is af dependent. */ | |
2632 | 1, /* timers active (only the expire timer) */ | |
a399a805 | 2633 | jiffies_delta_to_clock_t(delta), |
e6c022a4 | 2634 | req->num_timeout, |
aa3a0c8c ED |
2635 | from_kuid_munged(seq_user_ns(f), |
2636 | sock_i_uid(req->rsk_listener)), | |
1da177e4 LT |
2637 | 0, /* non standard timer */ |
2638 | 0, /* open_requests have no inode */ | |
d4f06873 | 2639 | 0, |
652586df | 2640 | req); |
1da177e4 LT |
2641 | } |
2642 | ||
652586df | 2643 | static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i) |
1da177e4 LT |
2644 | { |
2645 | int timer_active; | |
2646 | unsigned long timer_expires; | |
cf533ea5 | 2647 | const struct tcp_sock *tp = tcp_sk(sk); |
cf4c6bf8 | 2648 | const struct inet_connection_sock *icsk = inet_csk(sk); |
cf533ea5 | 2649 | const struct inet_sock *inet = inet_sk(sk); |
0536fcc0 | 2650 | const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq; |
c720c7e8 ED |
2651 | __be32 dest = inet->inet_daddr; |
2652 | __be32 src = inet->inet_rcv_saddr; | |
2653 | __u16 destp = ntohs(inet->inet_dport); | |
2654 | __u16 srcp = ntohs(inet->inet_sport); | |
49d09007 | 2655 | int rx_queue; |
00fd38d9 | 2656 | int state; |
1da177e4 | 2657 | |
6ba8a3b1 | 2658 | if (icsk->icsk_pending == ICSK_TIME_RETRANS || |
57dde7f7 | 2659 | icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || |
6ba8a3b1 | 2660 | icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { |
1da177e4 | 2661 | timer_active = 1; |
463c84b9 ACM |
2662 | timer_expires = icsk->icsk_timeout; |
2663 | } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { | |
1da177e4 | 2664 | timer_active = 4; |
463c84b9 | 2665 | timer_expires = icsk->icsk_timeout; |
cf4c6bf8 | 2666 | } else if (timer_pending(&sk->sk_timer)) { |
1da177e4 | 2667 | timer_active = 2; |
cf4c6bf8 | 2668 | timer_expires = sk->sk_timer.expires; |
1da177e4 LT |
2669 | } else { |
2670 | timer_active = 0; | |
2671 | timer_expires = jiffies; | |
2672 | } | |
2673 | ||
986ffdfd | 2674 | state = inet_sk_state_load(sk); |
00fd38d9 | 2675 | if (state == TCP_LISTEN) |
288efe86 | 2676 | rx_queue = READ_ONCE(sk->sk_ack_backlog); |
49d09007 | 2677 | else |
00fd38d9 ED |
2678 | /* Because we don't lock the socket, |
2679 | * we might find a transient negative value. | |
49d09007 | 2680 | */ |
dba7d9b8 | 2681 | rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) - |
7db48e98 | 2682 | READ_ONCE(tp->copied_seq), 0); |
49d09007 | 2683 | |
5e659e4c | 2684 | seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX " |
652586df | 2685 | "%08X %5u %8d %lu %d %pK %lu %lu %u %u %d", |
00fd38d9 | 2686 | i, src, srcp, dest, destp, state, |
0f317464 | 2687 | READ_ONCE(tp->write_seq) - tp->snd_una, |
49d09007 | 2688 | rx_queue, |
1da177e4 | 2689 | timer_active, |
a399a805 | 2690 | jiffies_delta_to_clock_t(timer_expires - jiffies), |
463c84b9 | 2691 | icsk->icsk_retransmits, |
a7cb5a49 | 2692 | from_kuid_munged(seq_user_ns(f), sock_i_uid(sk)), |
6687e988 | 2693 | icsk->icsk_probes_out, |
cf4c6bf8 | 2694 | sock_i_ino(sk), |
41c6d650 | 2695 | refcount_read(&sk->sk_refcnt), sk, |
7be87351 SH |
2696 | jiffies_to_clock_t(icsk->icsk_rto), |
2697 | jiffies_to_clock_t(icsk->icsk_ack.ato), | |
31954cd8 | 2698 | (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sk), |
40570375 | 2699 | tcp_snd_cwnd(tp), |
00fd38d9 ED |
2700 | state == TCP_LISTEN ? |
2701 | fastopenq->max_qlen : | |
652586df | 2702 | (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)); |
1da177e4 LT |
2703 | } |
2704 | ||
cf533ea5 | 2705 | static void get_timewait4_sock(const struct inet_timewait_sock *tw, |
652586df | 2706 | struct seq_file *f, int i) |
1da177e4 | 2707 | { |
789f558c | 2708 | long delta = tw->tw_timer.expires - jiffies; |
23f33c2d | 2709 | __be32 dest, src; |
1da177e4 | 2710 | __u16 destp, srcp; |
1da177e4 LT |
2711 | |
2712 | dest = tw->tw_daddr; | |
2713 | src = tw->tw_rcv_saddr; | |
2714 | destp = ntohs(tw->tw_dport); | |
2715 | srcp = ntohs(tw->tw_sport); | |
2716 | ||
5e659e4c | 2717 | seq_printf(f, "%4d: %08X:%04X %08X:%04X" |
652586df | 2718 | " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK", |
1da177e4 | 2719 | i, src, srcp, dest, destp, tw->tw_substate, 0, 0, |
a399a805 | 2720 | 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0, |
41c6d650 | 2721 | refcount_read(&tw->tw_refcnt), tw); |
1da177e4 LT |
2722 | } |
2723 | ||
2724 | #define TMPSZ 150 | |
2725 | ||
2726 | static int tcp4_seq_show(struct seq_file *seq, void *v) | |
2727 | { | |
5799de0b | 2728 | struct tcp_iter_state *st; |
05dbc7b5 | 2729 | struct sock *sk = v; |
1da177e4 | 2730 | |
652586df | 2731 | seq_setwidth(seq, TMPSZ - 1); |
1da177e4 | 2732 | if (v == SEQ_START_TOKEN) { |
652586df | 2733 | seq_puts(seq, " sl local_address rem_address st tx_queue " |
1da177e4 LT |
2734 | "rx_queue tr tm->when retrnsmt uid timeout " |
2735 | "inode"); | |
2736 | goto out; | |
2737 | } | |
2738 | st = seq->private; | |
2739 | ||
079096f1 ED |
2740 | if (sk->sk_state == TCP_TIME_WAIT) |
2741 | get_timewait4_sock(v, seq, st->num); | |
2742 | else if (sk->sk_state == TCP_NEW_SYN_RECV) | |
aa3a0c8c | 2743 | get_openreq4(v, seq, st->num); |
079096f1 ED |
2744 | else |
2745 | get_tcp4_sock(v, seq, st->num); | |
1da177e4 | 2746 | out: |
652586df | 2747 | seq_pad(seq, '\n'); |
1da177e4 LT |
2748 | return 0; |
2749 | } | |
2750 | ||
52d87d5f | 2751 | #ifdef CONFIG_BPF_SYSCALL |
04c7820b MKL |
2752 | struct bpf_tcp_iter_state { |
2753 | struct tcp_iter_state state; | |
2754 | unsigned int cur_sk; | |
2755 | unsigned int end_sk; | |
2756 | unsigned int max_sk; | |
2757 | struct sock **batch; | |
2758 | bool st_bucket_done; | |
2759 | }; | |
2760 | ||
52d87d5f YS |
2761 | struct bpf_iter__tcp { |
2762 | __bpf_md_ptr(struct bpf_iter_meta *, meta); | |
2763 | __bpf_md_ptr(struct sock_common *, sk_common); | |
2764 | uid_t uid __aligned(8); | |
2765 | }; | |
2766 | ||
2767 | static int tcp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta, | |
2768 | struct sock_common *sk_common, uid_t uid) | |
2769 | { | |
2770 | struct bpf_iter__tcp ctx; | |
2771 | ||
2772 | meta->seq_num--; /* skip SEQ_START_TOKEN */ | |
2773 | ctx.meta = meta; | |
2774 | ctx.sk_common = sk_common; | |
2775 | ctx.uid = uid; | |
2776 | return bpf_iter_run_prog(prog, &ctx); | |
2777 | } | |
2778 | ||
04c7820b MKL |
2779 | static void bpf_iter_tcp_put_batch(struct bpf_tcp_iter_state *iter) |
2780 | { | |
2781 | while (iter->cur_sk < iter->end_sk) | |
2782 | sock_put(iter->batch[iter->cur_sk++]); | |
2783 | } | |
2784 | ||
2785 | static int bpf_iter_tcp_realloc_batch(struct bpf_tcp_iter_state *iter, | |
2786 | unsigned int new_batch_sz) | |
2787 | { | |
2788 | struct sock **new_batch; | |
2789 | ||
2790 | new_batch = kvmalloc(sizeof(*new_batch) * new_batch_sz, | |
2791 | GFP_USER | __GFP_NOWARN); | |
2792 | if (!new_batch) | |
2793 | return -ENOMEM; | |
2794 | ||
2795 | bpf_iter_tcp_put_batch(iter); | |
2796 | kvfree(iter->batch); | |
2797 | iter->batch = new_batch; | |
2798 | iter->max_sk = new_batch_sz; | |
2799 | ||
2800 | return 0; | |
2801 | } | |
2802 | ||
2803 | static unsigned int bpf_iter_tcp_listening_batch(struct seq_file *seq, | |
2804 | struct sock *start_sk) | |
2805 | { | |
4461568a | 2806 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
04c7820b MKL |
2807 | struct bpf_tcp_iter_state *iter = seq->private; |
2808 | struct tcp_iter_state *st = &iter->state; | |
cae3873c | 2809 | struct hlist_nulls_node *node; |
04c7820b MKL |
2810 | unsigned int expected = 1; |
2811 | struct sock *sk; | |
2812 | ||
2813 | sock_hold(start_sk); | |
2814 | iter->batch[iter->end_sk++] = start_sk; | |
2815 | ||
cae3873c MKL |
2816 | sk = sk_nulls_next(start_sk); |
2817 | sk_nulls_for_each_from(sk, node) { | |
04c7820b MKL |
2818 | if (seq_sk_match(seq, sk)) { |
2819 | if (iter->end_sk < iter->max_sk) { | |
2820 | sock_hold(sk); | |
2821 | iter->batch[iter->end_sk++] = sk; | |
2822 | } | |
2823 | expected++; | |
2824 | } | |
2825 | } | |
4461568a | 2826 | spin_unlock(&hinfo->lhash2[st->bucket].lock); |
04c7820b MKL |
2827 | |
2828 | return expected; | |
2829 | } | |
2830 | ||
2831 | static unsigned int bpf_iter_tcp_established_batch(struct seq_file *seq, | |
2832 | struct sock *start_sk) | |
2833 | { | |
4461568a | 2834 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
04c7820b MKL |
2835 | struct bpf_tcp_iter_state *iter = seq->private; |
2836 | struct tcp_iter_state *st = &iter->state; | |
2837 | struct hlist_nulls_node *node; | |
2838 | unsigned int expected = 1; | |
2839 | struct sock *sk; | |
2840 | ||
2841 | sock_hold(start_sk); | |
2842 | iter->batch[iter->end_sk++] = start_sk; | |
2843 | ||
2844 | sk = sk_nulls_next(start_sk); | |
2845 | sk_nulls_for_each_from(sk, node) { | |
2846 | if (seq_sk_match(seq, sk)) { | |
2847 | if (iter->end_sk < iter->max_sk) { | |
2848 | sock_hold(sk); | |
2849 | iter->batch[iter->end_sk++] = sk; | |
2850 | } | |
2851 | expected++; | |
2852 | } | |
2853 | } | |
4461568a | 2854 | spin_unlock_bh(inet_ehash_lockp(hinfo, st->bucket)); |
04c7820b MKL |
2855 | |
2856 | return expected; | |
2857 | } | |
2858 | ||
2859 | static struct sock *bpf_iter_tcp_batch(struct seq_file *seq) | |
2860 | { | |
4461568a | 2861 | struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
04c7820b MKL |
2862 | struct bpf_tcp_iter_state *iter = seq->private; |
2863 | struct tcp_iter_state *st = &iter->state; | |
2864 | unsigned int expected; | |
2865 | bool resized = false; | |
2866 | struct sock *sk; | |
2867 | ||
2868 | /* The st->bucket is done. Directly advance to the next | |
2869 | * bucket instead of having the tcp_seek_last_pos() to skip | |
2870 | * one by one in the current bucket and eventually find out | |
2871 | * it has to advance to the next bucket. | |
2872 | */ | |
2873 | if (iter->st_bucket_done) { | |
2874 | st->offset = 0; | |
2875 | st->bucket++; | |
2876 | if (st->state == TCP_SEQ_STATE_LISTENING && | |
4461568a | 2877 | st->bucket > hinfo->lhash2_mask) { |
04c7820b MKL |
2878 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2879 | st->bucket = 0; | |
2880 | } | |
2881 | } | |
2882 | ||
2883 | again: | |
2884 | /* Get a new batch */ | |
2885 | iter->cur_sk = 0; | |
2886 | iter->end_sk = 0; | |
2887 | iter->st_bucket_done = false; | |
2888 | ||
2889 | sk = tcp_seek_last_pos(seq); | |
2890 | if (!sk) | |
2891 | return NULL; /* Done */ | |
2892 | ||
2893 | if (st->state == TCP_SEQ_STATE_LISTENING) | |
2894 | expected = bpf_iter_tcp_listening_batch(seq, sk); | |
2895 | else | |
2896 | expected = bpf_iter_tcp_established_batch(seq, sk); | |
2897 | ||
2898 | if (iter->end_sk == expected) { | |
2899 | iter->st_bucket_done = true; | |
2900 | return sk; | |
2901 | } | |
2902 | ||
2903 | if (!resized && !bpf_iter_tcp_realloc_batch(iter, expected * 3 / 2)) { | |
2904 | resized = true; | |
2905 | goto again; | |
2906 | } | |
2907 | ||
2908 | return sk; | |
2909 | } | |
2910 | ||
2911 | static void *bpf_iter_tcp_seq_start(struct seq_file *seq, loff_t *pos) | |
2912 | { | |
2913 | /* bpf iter does not support lseek, so it always | |
2914 | * continue from where it was stop()-ped. | |
2915 | */ | |
2916 | if (*pos) | |
2917 | return bpf_iter_tcp_batch(seq); | |
2918 | ||
2919 | return SEQ_START_TOKEN; | |
2920 | } | |
2921 | ||
2922 | static void *bpf_iter_tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2923 | { | |
2924 | struct bpf_tcp_iter_state *iter = seq->private; | |
2925 | struct tcp_iter_state *st = &iter->state; | |
2926 | struct sock *sk; | |
2927 | ||
2928 | /* Whenever seq_next() is called, the iter->cur_sk is | |
2929 | * done with seq_show(), so advance to the next sk in | |
2930 | * the batch. | |
2931 | */ | |
2932 | if (iter->cur_sk < iter->end_sk) { | |
2933 | /* Keeping st->num consistent in tcp_iter_state. | |
2934 | * bpf_iter_tcp does not use st->num. | |
2935 | * meta.seq_num is used instead. | |
2936 | */ | |
2937 | st->num++; | |
2938 | /* Move st->offset to the next sk in the bucket such that | |
2939 | * the future start() will resume at st->offset in | |
2940 | * st->bucket. See tcp_seek_last_pos(). | |
2941 | */ | |
2942 | st->offset++; | |
2943 | sock_put(iter->batch[iter->cur_sk++]); | |
2944 | } | |
2945 | ||
2946 | if (iter->cur_sk < iter->end_sk) | |
2947 | sk = iter->batch[iter->cur_sk]; | |
2948 | else | |
2949 | sk = bpf_iter_tcp_batch(seq); | |
2950 | ||
2951 | ++*pos; | |
2952 | /* Keeping st->last_pos consistent in tcp_iter_state. | |
2953 | * bpf iter does not do lseek, so st->last_pos always equals to *pos. | |
2954 | */ | |
2955 | st->last_pos = *pos; | |
2956 | return sk; | |
2957 | } | |
2958 | ||
52d87d5f YS |
2959 | static int bpf_iter_tcp_seq_show(struct seq_file *seq, void *v) |
2960 | { | |
2961 | struct bpf_iter_meta meta; | |
2962 | struct bpf_prog *prog; | |
2963 | struct sock *sk = v; | |
04c7820b | 2964 | bool slow; |
52d87d5f | 2965 | uid_t uid; |
04c7820b | 2966 | int ret; |
52d87d5f YS |
2967 | |
2968 | if (v == SEQ_START_TOKEN) | |
2969 | return 0; | |
2970 | ||
04c7820b MKL |
2971 | if (sk_fullsock(sk)) |
2972 | slow = lock_sock_fast(sk); | |
2973 | ||
2974 | if (unlikely(sk_unhashed(sk))) { | |
2975 | ret = SEQ_SKIP; | |
2976 | goto unlock; | |
2977 | } | |
2978 | ||
52d87d5f YS |
2979 | if (sk->sk_state == TCP_TIME_WAIT) { |
2980 | uid = 0; | |
2981 | } else if (sk->sk_state == TCP_NEW_SYN_RECV) { | |
2982 | const struct request_sock *req = v; | |
2983 | ||
2984 | uid = from_kuid_munged(seq_user_ns(seq), | |
2985 | sock_i_uid(req->rsk_listener)); | |
2986 | } else { | |
2987 | uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)); | |
2988 | } | |
2989 | ||
2990 | meta.seq = seq; | |
2991 | prog = bpf_iter_get_info(&meta, false); | |
04c7820b MKL |
2992 | ret = tcp_prog_seq_show(prog, &meta, v, uid); |
2993 | ||
2994 | unlock: | |
2995 | if (sk_fullsock(sk)) | |
2996 | unlock_sock_fast(sk, slow); | |
2997 | return ret; | |
2998 | ||
52d87d5f YS |
2999 | } |
3000 | ||
3001 | static void bpf_iter_tcp_seq_stop(struct seq_file *seq, void *v) | |
3002 | { | |
04c7820b | 3003 | struct bpf_tcp_iter_state *iter = seq->private; |
52d87d5f YS |
3004 | struct bpf_iter_meta meta; |
3005 | struct bpf_prog *prog; | |
3006 | ||
3007 | if (!v) { | |
3008 | meta.seq = seq; | |
3009 | prog = bpf_iter_get_info(&meta, true); | |
3010 | if (prog) | |
3011 | (void)tcp_prog_seq_show(prog, &meta, v, 0); | |
3012 | } | |
3013 | ||
04c7820b MKL |
3014 | if (iter->cur_sk < iter->end_sk) { |
3015 | bpf_iter_tcp_put_batch(iter); | |
3016 | iter->st_bucket_done = false; | |
3017 | } | |
52d87d5f YS |
3018 | } |
3019 | ||
3020 | static const struct seq_operations bpf_iter_tcp_seq_ops = { | |
3021 | .show = bpf_iter_tcp_seq_show, | |
04c7820b MKL |
3022 | .start = bpf_iter_tcp_seq_start, |
3023 | .next = bpf_iter_tcp_seq_next, | |
52d87d5f YS |
3024 | .stop = bpf_iter_tcp_seq_stop, |
3025 | }; | |
3026 | #endif | |
ad2d6137 MKL |
3027 | static unsigned short seq_file_family(const struct seq_file *seq) |
3028 | { | |
62001372 | 3029 | const struct tcp_seq_afinfo *afinfo; |
ad2d6137 | 3030 | |
62001372 | 3031 | #ifdef CONFIG_BPF_SYSCALL |
ad2d6137 | 3032 | /* Iterated from bpf_iter. Let the bpf prog to filter instead. */ |
62001372 | 3033 | if (seq->op == &bpf_iter_tcp_seq_ops) |
ad2d6137 | 3034 | return AF_UNSPEC; |
52d87d5f YS |
3035 | #endif |
3036 | ||
ad2d6137 | 3037 | /* Iterated from proc fs */ |
359745d7 | 3038 | afinfo = pde_data(file_inode(seq->file)); |
ad2d6137 MKL |
3039 | return afinfo->family; |
3040 | } | |
52d87d5f | 3041 | |
37d849bb CH |
3042 | static const struct seq_operations tcp4_seq_ops = { |
3043 | .show = tcp4_seq_show, | |
3044 | .start = tcp_seq_start, | |
3045 | .next = tcp_seq_next, | |
3046 | .stop = tcp_seq_stop, | |
3047 | }; | |
3048 | ||
1da177e4 | 3049 | static struct tcp_seq_afinfo tcp4_seq_afinfo = { |
1da177e4 | 3050 | .family = AF_INET, |
1da177e4 LT |
3051 | }; |
3052 | ||
2c8c1e72 | 3053 | static int __net_init tcp4_proc_init_net(struct net *net) |
757764f6 | 3054 | { |
c3506372 CH |
3055 | if (!proc_create_net_data("tcp", 0444, net->proc_net, &tcp4_seq_ops, |
3056 | sizeof(struct tcp_iter_state), &tcp4_seq_afinfo)) | |
37d849bb CH |
3057 | return -ENOMEM; |
3058 | return 0; | |
757764f6 PE |
3059 | } |
3060 | ||
2c8c1e72 | 3061 | static void __net_exit tcp4_proc_exit_net(struct net *net) |
757764f6 | 3062 | { |
37d849bb | 3063 | remove_proc_entry("tcp", net->proc_net); |
757764f6 PE |
3064 | } |
3065 | ||
3066 | static struct pernet_operations tcp4_net_ops = { | |
3067 | .init = tcp4_proc_init_net, | |
3068 | .exit = tcp4_proc_exit_net, | |
3069 | }; | |
3070 | ||
1da177e4 LT |
3071 | int __init tcp4_proc_init(void) |
3072 | { | |
757764f6 | 3073 | return register_pernet_subsys(&tcp4_net_ops); |
1da177e4 LT |
3074 | } |
3075 | ||
3076 | void tcp4_proc_exit(void) | |
3077 | { | |
757764f6 | 3078 | unregister_pernet_subsys(&tcp4_net_ops); |
1da177e4 LT |
3079 | } |
3080 | #endif /* CONFIG_PROC_FS */ | |
3081 | ||
d3cd4924 ED |
3082 | /* @wake is one when sk_stream_write_space() calls us. |
3083 | * This sends EPOLLOUT only if notsent_bytes is half the limit. | |
3084 | * This mimics the strategy used in sock_def_write_space(). | |
3085 | */ | |
3086 | bool tcp_stream_memory_free(const struct sock *sk, int wake) | |
3087 | { | |
3088 | const struct tcp_sock *tp = tcp_sk(sk); | |
3089 | u32 notsent_bytes = READ_ONCE(tp->write_seq) - | |
3090 | READ_ONCE(tp->snd_nxt); | |
3091 | ||
3092 | return (notsent_bytes << wake) < tcp_notsent_lowat(tp); | |
3093 | } | |
3094 | EXPORT_SYMBOL(tcp_stream_memory_free); | |
3095 | ||
1da177e4 LT |
3096 | struct proto tcp_prot = { |
3097 | .name = "TCP", | |
3098 | .owner = THIS_MODULE, | |
3099 | .close = tcp_close, | |
d74bad4e | 3100 | .pre_connect = tcp_v4_pre_connect, |
1da177e4 LT |
3101 | .connect = tcp_v4_connect, |
3102 | .disconnect = tcp_disconnect, | |
463c84b9 | 3103 | .accept = inet_csk_accept, |
1da177e4 LT |
3104 | .ioctl = tcp_ioctl, |
3105 | .init = tcp_v4_init_sock, | |
3106 | .destroy = tcp_v4_destroy_sock, | |
3107 | .shutdown = tcp_shutdown, | |
3108 | .setsockopt = tcp_setsockopt, | |
3109 | .getsockopt = tcp_getsockopt, | |
9cacf81f | 3110 | .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt, |
4b9d07a4 | 3111 | .keepalive = tcp_set_keepalive, |
1da177e4 | 3112 | .recvmsg = tcp_recvmsg, |
7ba42910 CG |
3113 | .sendmsg = tcp_sendmsg, |
3114 | .sendpage = tcp_sendpage, | |
1da177e4 | 3115 | .backlog_rcv = tcp_v4_do_rcv, |
46d3ceab | 3116 | .release_cb = tcp_release_cb, |
ab1e0a13 ACM |
3117 | .hash = inet_hash, |
3118 | .unhash = inet_unhash, | |
3119 | .get_port = inet_csk_get_port, | |
91a760b2 | 3120 | .put_port = inet_put_port, |
8a59f9d1 CW |
3121 | #ifdef CONFIG_BPF_SYSCALL |
3122 | .psock_update_sk_prot = tcp_bpf_update_proto, | |
3123 | #endif | |
1da177e4 | 3124 | .enter_memory_pressure = tcp_enter_memory_pressure, |
06044751 | 3125 | .leave_memory_pressure = tcp_leave_memory_pressure, |
c9bee3b7 | 3126 | .stream_memory_free = tcp_stream_memory_free, |
1da177e4 | 3127 | .sockets_allocated = &tcp_sockets_allocated, |
0a5578cf | 3128 | .orphan_count = &tcp_orphan_count, |
0defbb0a | 3129 | |
1da177e4 | 3130 | .memory_allocated = &tcp_memory_allocated, |
0defbb0a ED |
3131 | .per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc, |
3132 | ||
1da177e4 | 3133 | .memory_pressure = &tcp_memory_pressure, |
a4fe34bf | 3134 | .sysctl_mem = sysctl_tcp_mem, |
356d1833 ED |
3135 | .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem), |
3136 | .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem), | |
1da177e4 LT |
3137 | .max_header = MAX_TCP_HEADER, |
3138 | .obj_size = sizeof(struct tcp_sock), | |
5f0d5a3a | 3139 | .slab_flags = SLAB_TYPESAFE_BY_RCU, |
6d6ee43e | 3140 | .twsk_prot = &tcp_timewait_sock_ops, |
60236fdd | 3141 | .rsk_prot = &tcp_request_sock_ops, |
429e42c1 | 3142 | .h.hashinfo = NULL, |
7ba42910 | 3143 | .no_autobind = true, |
c1e64e29 | 3144 | .diag_destroy = tcp_abort, |
1da177e4 | 3145 | }; |
4bc2f18b | 3146 | EXPORT_SYMBOL(tcp_prot); |
1da177e4 | 3147 | |
bdbbb852 ED |
3148 | static void __net_exit tcp_sk_exit(struct net *net) |
3149 | { | |
b506bc97 | 3150 | if (net->ipv4.tcp_congestion_control) |
0baf26b0 MKL |
3151 | bpf_module_put(net->ipv4.tcp_congestion_control, |
3152 | net->ipv4.tcp_congestion_control->owner); | |
bdbbb852 ED |
3153 | } |
3154 | ||
d1e5e640 | 3155 | static void __net_init tcp_set_hashinfo(struct net *net) |
046ee902 | 3156 | { |
d1e5e640 KI |
3157 | struct inet_hashinfo *hinfo; |
3158 | unsigned int ehash_entries; | |
3159 | struct net *old_net; | |
3160 | ||
3161 | if (net_eq(net, &init_net)) | |
3162 | goto fallback; | |
3163 | ||
3164 | old_net = current->nsproxy->net_ns; | |
3165 | ehash_entries = READ_ONCE(old_net->ipv4.sysctl_tcp_child_ehash_entries); | |
3166 | if (!ehash_entries) | |
3167 | goto fallback; | |
3168 | ||
3169 | ehash_entries = roundup_pow_of_two(ehash_entries); | |
3170 | hinfo = inet_pernet_hashinfo_alloc(&tcp_hashinfo, ehash_entries); | |
3171 | if (!hinfo) { | |
3172 | pr_warn("Failed to allocate TCP ehash (entries: %u) " | |
3173 | "for a netns, fallback to the global one\n", | |
3174 | ehash_entries); | |
3175 | fallback: | |
3176 | hinfo = &tcp_hashinfo; | |
3177 | ehash_entries = tcp_hashinfo.ehash_mask + 1; | |
3178 | } | |
3179 | ||
3180 | net->ipv4.tcp_death_row.hashinfo = hinfo; | |
3181 | net->ipv4.tcp_death_row.sysctl_max_tw_buckets = ehash_entries / 2; | |
3182 | net->ipv4.sysctl_max_syn_backlog = max(128U, ehash_entries / 128); | |
3183 | } | |
49213555 | 3184 | |
d1e5e640 KI |
3185 | static int __net_init tcp_sk_init(struct net *net) |
3186 | { | |
5d134f1c | 3187 | net->ipv4.sysctl_tcp_ecn = 2; |
49213555 DB |
3188 | net->ipv4.sysctl_tcp_ecn_fallback = 1; |
3189 | ||
b0f9ca53 | 3190 | net->ipv4.sysctl_tcp_base_mss = TCP_BASE_MSS; |
5f3e2bf0 | 3191 | net->ipv4.sysctl_tcp_min_snd_mss = TCP_MIN_SND_MSS; |
6b58e0a5 | 3192 | net->ipv4.sysctl_tcp_probe_threshold = TCP_PROBE_THRESHOLD; |
05cbc0db | 3193 | net->ipv4.sysctl_tcp_probe_interval = TCP_PROBE_INTERVAL; |
c04b79b6 | 3194 | net->ipv4.sysctl_tcp_mtu_probe_floor = TCP_MIN_SND_MSS; |
046ee902 | 3195 | |
13b287e8 | 3196 | net->ipv4.sysctl_tcp_keepalive_time = TCP_KEEPALIVE_TIME; |
9bd6861b | 3197 | net->ipv4.sysctl_tcp_keepalive_probes = TCP_KEEPALIVE_PROBES; |
b840d15d | 3198 | net->ipv4.sysctl_tcp_keepalive_intvl = TCP_KEEPALIVE_INTVL; |
13b287e8 | 3199 | |
6fa25166 | 3200 | net->ipv4.sysctl_tcp_syn_retries = TCP_SYN_RETRIES; |
7c083ecb | 3201 | net->ipv4.sysctl_tcp_synack_retries = TCP_SYNACK_RETRIES; |
0aca737d | 3202 | net->ipv4.sysctl_tcp_syncookies = 1; |
1043e25f | 3203 | net->ipv4.sysctl_tcp_reordering = TCP_FASTRETRANS_THRESH; |
ae5c3f40 | 3204 | net->ipv4.sysctl_tcp_retries1 = TCP_RETR1; |
c6214a97 | 3205 | net->ipv4.sysctl_tcp_retries2 = TCP_RETR2; |
c402d9be | 3206 | net->ipv4.sysctl_tcp_orphan_retries = 0; |
1e579caa | 3207 | net->ipv4.sysctl_tcp_fin_timeout = TCP_FIN_TIMEOUT; |
4979f2d9 | 3208 | net->ipv4.sysctl_tcp_notsent_lowat = UINT_MAX; |
79e9fed4 | 3209 | net->ipv4.sysctl_tcp_tw_reuse = 2; |
65e6d901 | 3210 | net->ipv4.sysctl_tcp_no_ssthresh_metrics_save = 1; |
12ed8244 | 3211 | |
e9bd0cca | 3212 | refcount_set(&net->ipv4.tcp_death_row.tw_refcount, 1); |
d1e5e640 | 3213 | tcp_set_hashinfo(net); |
1946e672 | 3214 | |
f9301034 | 3215 | net->ipv4.sysctl_tcp_sack = 1; |
9bb37ef0 | 3216 | net->ipv4.sysctl_tcp_window_scaling = 1; |
5d2ed052 | 3217 | net->ipv4.sysctl_tcp_timestamps = 1; |
2ae21cf5 | 3218 | net->ipv4.sysctl_tcp_early_retrans = 3; |
e20223f1 | 3219 | net->ipv4.sysctl_tcp_recovery = TCP_RACK_LOSS_DETECTION; |
b510f0d2 | 3220 | net->ipv4.sysctl_tcp_slow_start_after_idle = 1; /* By default, RFC2861 behavior. */ |
e0a1e5b5 | 3221 | net->ipv4.sysctl_tcp_retrans_collapse = 1; |
c6e21803 | 3222 | net->ipv4.sysctl_tcp_max_reordering = 300; |
6496f6bd | 3223 | net->ipv4.sysctl_tcp_dsack = 1; |
0c12654a | 3224 | net->ipv4.sysctl_tcp_app_win = 31; |
94f0893e | 3225 | net->ipv4.sysctl_tcp_adv_win_scale = 1; |
af9b69a7 | 3226 | net->ipv4.sysctl_tcp_frto = 2; |
4540c0cf | 3227 | net->ipv4.sysctl_tcp_moderate_rcvbuf = 1; |
d06a9904 ED |
3228 | /* This limits the percentage of the congestion window which we |
3229 | * will allow a single TSO frame to consume. Building TSO frames | |
3230 | * which are too large can cause TCP streams to be bursty. | |
3231 | */ | |
3232 | net->ipv4.sysctl_tcp_tso_win_divisor = 3; | |
c73e5807 ED |
3233 | /* Default TSQ limit of 16 TSO segments */ |
3234 | net->ipv4.sysctl_tcp_limit_output_bytes = 16 * 65536; | |
79e3602c ED |
3235 | |
3236 | /* rfc5961 challenge ack rate limiting, per net-ns, disabled by default. */ | |
3237 | net->ipv4.sysctl_tcp_challenge_ack_limit = INT_MAX; | |
3238 | ||
26e9596e | 3239 | net->ipv4.sysctl_tcp_min_tso_segs = 2; |
65466904 | 3240 | net->ipv4.sysctl_tcp_tso_rtt_log = 9; /* 2^9 = 512 usec */ |
bd239704 | 3241 | net->ipv4.sysctl_tcp_min_rtt_wlen = 300; |
790f00e1 | 3242 | net->ipv4.sysctl_tcp_autocorking = 1; |
4170ba6b | 3243 | net->ipv4.sysctl_tcp_invalid_ratelimit = HZ/2; |
23a7102a | 3244 | net->ipv4.sysctl_tcp_pacing_ss_ratio = 200; |
c26e91f8 | 3245 | net->ipv4.sysctl_tcp_pacing_ca_ratio = 120; |
356d1833 ED |
3246 | if (net != &init_net) { |
3247 | memcpy(net->ipv4.sysctl_tcp_rmem, | |
3248 | init_net.ipv4.sysctl_tcp_rmem, | |
3249 | sizeof(init_net.ipv4.sysctl_tcp_rmem)); | |
3250 | memcpy(net->ipv4.sysctl_tcp_wmem, | |
3251 | init_net.ipv4.sysctl_tcp_wmem, | |
3252 | sizeof(init_net.ipv4.sysctl_tcp_wmem)); | |
3253 | } | |
6d82aa24 | 3254 | net->ipv4.sysctl_tcp_comp_sack_delay_ns = NSEC_PER_MSEC; |
a70437cc | 3255 | net->ipv4.sysctl_tcp_comp_sack_slack_ns = 100 * NSEC_PER_USEC; |
9c21d2fc | 3256 | net->ipv4.sysctl_tcp_comp_sack_nr = 44; |
e1cfcbe8 | 3257 | net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE; |
213ad73d | 3258 | net->ipv4.sysctl_tcp_fastopen_blackhole_timeout = 0; |
3733be14 | 3259 | atomic_set(&net->ipv4.tfo_active_disable_times, 0); |
e1cfcbe8 | 3260 | |
bd456f28 MAQ |
3261 | /* Set default values for PLB */ |
3262 | net->ipv4.sysctl_tcp_plb_enabled = 0; /* Disabled by default */ | |
3263 | net->ipv4.sysctl_tcp_plb_idle_rehash_rounds = 3; | |
3264 | net->ipv4.sysctl_tcp_plb_rehash_rounds = 12; | |
3265 | net->ipv4.sysctl_tcp_plb_suspend_rto_sec = 60; | |
3266 | /* Default congestion threshold for PLB to mark a round is 50% */ | |
1a91bb7c | 3267 | net->ipv4.sysctl_tcp_plb_cong_thresh = (1 << TCP_PLB_SCALE) / 2; |
bd456f28 | 3268 | |
6670e152 SH |
3269 | /* Reno is always built in */ |
3270 | if (!net_eq(net, &init_net) && | |
0baf26b0 MKL |
3271 | bpf_try_module_get(init_net.ipv4.tcp_congestion_control, |
3272 | init_net.ipv4.tcp_congestion_control->owner)) | |
6670e152 SH |
3273 | net->ipv4.tcp_congestion_control = init_net.ipv4.tcp_congestion_control; |
3274 | else | |
3275 | net->ipv4.tcp_congestion_control = &tcp_reno; | |
3276 | ||
49213555 | 3277 | return 0; |
b099ce26 EB |
3278 | } |
3279 | ||
3280 | static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list) | |
3281 | { | |
43713848 HY |
3282 | struct net *net; |
3283 | ||
edc12f03 | 3284 | tcp_twsk_purge(net_exit_list, AF_INET); |
04c494e6 | 3285 | |
e9bd0cca | 3286 | list_for_each_entry(net, net_exit_list, exit_list) { |
d1e5e640 | 3287 | inet_pernet_hashinfo_free(net->ipv4.tcp_death_row.hashinfo); |
e9bd0cca | 3288 | WARN_ON_ONCE(!refcount_dec_and_test(&net->ipv4.tcp_death_row.tw_refcount)); |
43713848 | 3289 | tcp_fastopen_ctx_destroy(net); |
e9bd0cca | 3290 | } |
046ee902 DL |
3291 | } |
3292 | ||
3293 | static struct pernet_operations __net_initdata tcp_sk_ops = { | |
b099ce26 EB |
3294 | .init = tcp_sk_init, |
3295 | .exit = tcp_sk_exit, | |
3296 | .exit_batch = tcp_sk_exit_batch, | |
046ee902 DL |
3297 | }; |
3298 | ||
52d87d5f YS |
3299 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
3300 | DEFINE_BPF_ITER_FUNC(tcp, struct bpf_iter_meta *meta, | |
3301 | struct sock_common *sk_common, uid_t uid) | |
3302 | ||
04c7820b MKL |
3303 | #define INIT_BATCH_SZ 16 |
3304 | ||
f9c79272 | 3305 | static int bpf_iter_init_tcp(void *priv_data, struct bpf_iter_aux_info *aux) |
52d87d5f | 3306 | { |
04c7820b MKL |
3307 | struct bpf_tcp_iter_state *iter = priv_data; |
3308 | int err; | |
52d87d5f | 3309 | |
04c7820b MKL |
3310 | err = bpf_iter_init_seq_net(priv_data, aux); |
3311 | if (err) | |
3312 | return err; | |
52d87d5f | 3313 | |
04c7820b MKL |
3314 | err = bpf_iter_tcp_realloc_batch(iter, INIT_BATCH_SZ); |
3315 | if (err) { | |
3316 | bpf_iter_fini_seq_net(priv_data); | |
3317 | return err; | |
3318 | } | |
3319 | ||
3320 | return 0; | |
52d87d5f YS |
3321 | } |
3322 | ||
3323 | static void bpf_iter_fini_tcp(void *priv_data) | |
3324 | { | |
04c7820b | 3325 | struct bpf_tcp_iter_state *iter = priv_data; |
52d87d5f | 3326 | |
52d87d5f | 3327 | bpf_iter_fini_seq_net(priv_data); |
04c7820b | 3328 | kvfree(iter->batch); |
52d87d5f YS |
3329 | } |
3330 | ||
14fc6bd6 | 3331 | static const struct bpf_iter_seq_info tcp_seq_info = { |
52d87d5f YS |
3332 | .seq_ops = &bpf_iter_tcp_seq_ops, |
3333 | .init_seq_private = bpf_iter_init_tcp, | |
3334 | .fini_seq_private = bpf_iter_fini_tcp, | |
04c7820b | 3335 | .seq_priv_size = sizeof(struct bpf_tcp_iter_state), |
14fc6bd6 YS |
3336 | }; |
3337 | ||
3cee6fb8 MKL |
3338 | static const struct bpf_func_proto * |
3339 | bpf_iter_tcp_get_func_proto(enum bpf_func_id func_id, | |
3340 | const struct bpf_prog *prog) | |
3341 | { | |
3342 | switch (func_id) { | |
3343 | case BPF_FUNC_setsockopt: | |
3344 | return &bpf_sk_setsockopt_proto; | |
3345 | case BPF_FUNC_getsockopt: | |
3346 | return &bpf_sk_getsockopt_proto; | |
3347 | default: | |
3348 | return NULL; | |
3349 | } | |
3350 | } | |
3351 | ||
14fc6bd6 YS |
3352 | static struct bpf_iter_reg tcp_reg_info = { |
3353 | .target = "tcp", | |
52d87d5f YS |
3354 | .ctx_arg_info_size = 1, |
3355 | .ctx_arg_info = { | |
3356 | { offsetof(struct bpf_iter__tcp, sk_common), | |
3357 | PTR_TO_BTF_ID_OR_NULL }, | |
3358 | }, | |
3cee6fb8 | 3359 | .get_func_proto = bpf_iter_tcp_get_func_proto, |
14fc6bd6 | 3360 | .seq_info = &tcp_seq_info, |
52d87d5f YS |
3361 | }; |
3362 | ||
3363 | static void __init bpf_iter_register(void) | |
3364 | { | |
951cf368 | 3365 | tcp_reg_info.ctx_arg_info[0].btf_id = btf_sock_ids[BTF_SOCK_TYPE_SOCK_COMMON]; |
52d87d5f YS |
3366 | if (bpf_iter_reg_target(&tcp_reg_info)) |
3367 | pr_warn("Warning: could not register bpf iterator tcp\n"); | |
3368 | } | |
3369 | ||
3370 | #endif | |
3371 | ||
9b0f976f | 3372 | void __init tcp_v4_init(void) |
1da177e4 | 3373 | { |
37ba017d ED |
3374 | int cpu, res; |
3375 | ||
3376 | for_each_possible_cpu(cpu) { | |
3377 | struct sock *sk; | |
3378 | ||
3379 | res = inet_ctl_sock_create(&sk, PF_INET, SOCK_RAW, | |
3380 | IPPROTO_TCP, &init_net); | |
3381 | if (res) | |
3382 | panic("Failed to create the TCP control socket.\n"); | |
3383 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
3384 | ||
3385 | /* Please enforce IP_DF and IPID==0 for RST and | |
3386 | * ACK sent in SYN-RECV and TIME-WAIT state. | |
3387 | */ | |
3388 | inet_sk(sk)->pmtudisc = IP_PMTUDISC_DO; | |
3389 | ||
3390 | per_cpu(ipv4_tcp_sk, cpu) = sk; | |
3391 | } | |
6a1b3054 | 3392 | if (register_pernet_subsys(&tcp_sk_ops)) |
1da177e4 | 3393 | panic("Failed to create the TCP control socket.\n"); |
52d87d5f YS |
3394 | |
3395 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) | |
3396 | bpf_iter_register(); | |
3397 | #endif | |
1da177e4 | 3398 | } |