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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * Implementation of the Transmission Control Protocol(TCP). | |
7 | * | |
1da177e4 LT |
8 | * IPv4 specific functions |
9 | * | |
10 | * | |
11 | * code split from: | |
12 | * linux/ipv4/tcp.c | |
13 | * linux/ipv4/tcp_input.c | |
14 | * linux/ipv4/tcp_output.c | |
15 | * | |
16 | * See tcp.c for author information | |
17 | * | |
18 | * This program is free software; you can redistribute it and/or | |
19 | * modify it under the terms of the GNU General Public License | |
20 | * as published by the Free Software Foundation; either version | |
21 | * 2 of the License, or (at your option) any later version. | |
22 | */ | |
23 | ||
24 | /* | |
25 | * Changes: | |
26 | * David S. Miller : New socket lookup architecture. | |
27 | * This code is dedicated to John Dyson. | |
28 | * David S. Miller : Change semantics of established hash, | |
29 | * half is devoted to TIME_WAIT sockets | |
30 | * and the rest go in the other half. | |
31 | * Andi Kleen : Add support for syncookies and fixed | |
32 | * some bugs: ip options weren't passed to | |
33 | * the TCP layer, missed a check for an | |
34 | * ACK bit. | |
35 | * Andi Kleen : Implemented fast path mtu discovery. | |
36 | * Fixed many serious bugs in the | |
60236fdd | 37 | * request_sock handling and moved |
1da177e4 LT |
38 | * most of it into the af independent code. |
39 | * Added tail drop and some other bugfixes. | |
caa20d9a | 40 | * Added new listen semantics. |
1da177e4 LT |
41 | * Mike McLagan : Routing by source |
42 | * Juan Jose Ciarlante: ip_dynaddr bits | |
43 | * Andi Kleen: various fixes. | |
44 | * Vitaly E. Lavrov : Transparent proxy revived after year | |
45 | * coma. | |
46 | * Andi Kleen : Fix new listen. | |
47 | * Andi Kleen : Fix accept error reporting. | |
48 | * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which | |
49 | * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind | |
50 | * a single port at the same time. | |
51 | */ | |
52 | ||
afd46503 | 53 | #define pr_fmt(fmt) "TCP: " fmt |
1da177e4 | 54 | |
eb4dea58 | 55 | #include <linux/bottom_half.h> |
1da177e4 LT |
56 | #include <linux/types.h> |
57 | #include <linux/fcntl.h> | |
58 | #include <linux/module.h> | |
59 | #include <linux/random.h> | |
60 | #include <linux/cache.h> | |
61 | #include <linux/jhash.h> | |
62 | #include <linux/init.h> | |
63 | #include <linux/times.h> | |
5a0e3ad6 | 64 | #include <linux/slab.h> |
1da177e4 | 65 | |
457c4cbc | 66 | #include <net/net_namespace.h> |
1da177e4 | 67 | #include <net/icmp.h> |
304a1618 | 68 | #include <net/inet_hashtables.h> |
1da177e4 | 69 | #include <net/tcp.h> |
20380731 | 70 | #include <net/transp_v6.h> |
1da177e4 LT |
71 | #include <net/ipv6.h> |
72 | #include <net/inet_common.h> | |
6d6ee43e | 73 | #include <net/timewait_sock.h> |
1da177e4 | 74 | #include <net/xfrm.h> |
6e5714ea | 75 | #include <net/secure_seq.h> |
076bb0c8 | 76 | #include <net/busy_poll.h> |
1da177e4 LT |
77 | |
78 | #include <linux/inet.h> | |
79 | #include <linux/ipv6.h> | |
80 | #include <linux/stddef.h> | |
81 | #include <linux/proc_fs.h> | |
82 | #include <linux/seq_file.h> | |
83 | ||
cf80e0e4 | 84 | #include <crypto/hash.h> |
cfb6eeb4 YH |
85 | #include <linux/scatterlist.h> |
86 | ||
ab32ea5d | 87 | int sysctl_tcp_low_latency __read_mostly; |
1da177e4 | 88 | |
cfb6eeb4 | 89 | #ifdef CONFIG_TCP_MD5SIG |
a915da9b | 90 | static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, |
318cf7aa | 91 | __be32 daddr, __be32 saddr, const struct tcphdr *th); |
cfb6eeb4 YH |
92 | #endif |
93 | ||
5caea4ea | 94 | struct inet_hashinfo tcp_hashinfo; |
4bc2f18b | 95 | EXPORT_SYMBOL(tcp_hashinfo); |
1da177e4 | 96 | |
95a22cae | 97 | static u32 tcp_v4_init_sequence(const struct sk_buff *skb, u32 *tsoff) |
1da177e4 | 98 | { |
eddc9ec5 ACM |
99 | return secure_tcp_sequence_number(ip_hdr(skb)->daddr, |
100 | ip_hdr(skb)->saddr, | |
aa8223c7 | 101 | tcp_hdr(skb)->dest, |
95a22cae | 102 | tcp_hdr(skb)->source, tsoff); |
1da177e4 LT |
103 | } |
104 | ||
6d6ee43e ACM |
105 | int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) |
106 | { | |
107 | const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw); | |
108 | struct tcp_sock *tp = tcp_sk(sk); | |
109 | ||
110 | /* With PAWS, it is safe from the viewpoint | |
111 | of data integrity. Even without PAWS it is safe provided sequence | |
112 | spaces do not overlap i.e. at data rates <= 80Mbit/sec. | |
113 | ||
114 | Actually, the idea is close to VJ's one, only timestamp cache is | |
115 | held not per host, but per port pair and TW bucket is used as state | |
116 | holder. | |
117 | ||
118 | If TW bucket has been already destroyed we fall back to VJ's scheme | |
119 | and use initial timestamp retrieved from peer table. | |
120 | */ | |
121 | if (tcptw->tw_ts_recent_stamp && | |
56ab6b93 | 122 | (!twp || (sock_net(sk)->ipv4.sysctl_tcp_tw_reuse && |
9d729f72 | 123 | get_seconds() - tcptw->tw_ts_recent_stamp > 1))) { |
6d6ee43e ACM |
124 | tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2; |
125 | if (tp->write_seq == 0) | |
126 | tp->write_seq = 1; | |
127 | tp->rx_opt.ts_recent = tcptw->tw_ts_recent; | |
128 | tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; | |
129 | sock_hold(sktw); | |
130 | return 1; | |
131 | } | |
132 | ||
133 | return 0; | |
134 | } | |
6d6ee43e ACM |
135 | EXPORT_SYMBOL_GPL(tcp_twsk_unique); |
136 | ||
1da177e4 LT |
137 | /* This will initiate an outgoing connection. */ |
138 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
139 | { | |
2d7192d6 | 140 | struct sockaddr_in *usin = (struct sockaddr_in *)uaddr; |
1da177e4 LT |
141 | struct inet_sock *inet = inet_sk(sk); |
142 | struct tcp_sock *tp = tcp_sk(sk); | |
dca8b089 | 143 | __be16 orig_sport, orig_dport; |
bada8adc | 144 | __be32 daddr, nexthop; |
da905bd1 | 145 | struct flowi4 *fl4; |
2d7192d6 | 146 | struct rtable *rt; |
1da177e4 | 147 | int err; |
00355fa5 | 148 | u32 seq; |
f6d8bd05 | 149 | struct ip_options_rcu *inet_opt; |
1946e672 | 150 | struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; |
1da177e4 LT |
151 | |
152 | if (addr_len < sizeof(struct sockaddr_in)) | |
153 | return -EINVAL; | |
154 | ||
155 | if (usin->sin_family != AF_INET) | |
156 | return -EAFNOSUPPORT; | |
157 | ||
158 | nexthop = daddr = usin->sin_addr.s_addr; | |
f6d8bd05 | 159 | inet_opt = rcu_dereference_protected(inet->inet_opt, |
1e1d04e6 | 160 | lockdep_sock_is_held(sk)); |
f6d8bd05 | 161 | if (inet_opt && inet_opt->opt.srr) { |
1da177e4 LT |
162 | if (!daddr) |
163 | return -EINVAL; | |
f6d8bd05 | 164 | nexthop = inet_opt->opt.faddr; |
1da177e4 LT |
165 | } |
166 | ||
dca8b089 DM |
167 | orig_sport = inet->inet_sport; |
168 | orig_dport = usin->sin_port; | |
da905bd1 DM |
169 | fl4 = &inet->cork.fl.u.ip4; |
170 | rt = ip_route_connect(fl4, nexthop, inet->inet_saddr, | |
b23dd4fe DM |
171 | RT_CONN_FLAGS(sk), sk->sk_bound_dev_if, |
172 | IPPROTO_TCP, | |
0e0d44ab | 173 | orig_sport, orig_dport, sk); |
b23dd4fe DM |
174 | if (IS_ERR(rt)) { |
175 | err = PTR_ERR(rt); | |
176 | if (err == -ENETUNREACH) | |
f1d8cba6 | 177 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
b23dd4fe | 178 | return err; |
584bdf8c | 179 | } |
1da177e4 LT |
180 | |
181 | if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { | |
182 | ip_rt_put(rt); | |
183 | return -ENETUNREACH; | |
184 | } | |
185 | ||
f6d8bd05 | 186 | if (!inet_opt || !inet_opt->opt.srr) |
da905bd1 | 187 | daddr = fl4->daddr; |
1da177e4 | 188 | |
c720c7e8 | 189 | if (!inet->inet_saddr) |
da905bd1 | 190 | inet->inet_saddr = fl4->saddr; |
d1e559d0 | 191 | sk_rcv_saddr_set(sk, inet->inet_saddr); |
1da177e4 | 192 | |
c720c7e8 | 193 | if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) { |
1da177e4 LT |
194 | /* Reset inherited state */ |
195 | tp->rx_opt.ts_recent = 0; | |
196 | tp->rx_opt.ts_recent_stamp = 0; | |
ee995283 PE |
197 | if (likely(!tp->repair)) |
198 | tp->write_seq = 0; | |
1da177e4 LT |
199 | } |
200 | ||
1946e672 | 201 | if (tcp_death_row->sysctl_tw_recycle && |
81166dd6 DM |
202 | !tp->rx_opt.ts_recent_stamp && fl4->daddr == daddr) |
203 | tcp_fetch_timewait_stamp(sk, &rt->dst); | |
1da177e4 | 204 | |
c720c7e8 | 205 | inet->inet_dport = usin->sin_port; |
d1e559d0 | 206 | sk_daddr_set(sk, daddr); |
1da177e4 | 207 | |
d83d8461 | 208 | inet_csk(sk)->icsk_ext_hdr_len = 0; |
f6d8bd05 ED |
209 | if (inet_opt) |
210 | inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen; | |
1da177e4 | 211 | |
bee7ca9e | 212 | tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT; |
1da177e4 LT |
213 | |
214 | /* Socket identity is still unknown (sport may be zero). | |
215 | * However we set state to SYN-SENT and not releasing socket | |
216 | * lock select source port, enter ourselves into the hash tables and | |
217 | * complete initialization after this. | |
218 | */ | |
219 | tcp_set_state(sk, TCP_SYN_SENT); | |
1946e672 | 220 | err = inet_hash_connect(tcp_death_row, sk); |
1da177e4 LT |
221 | if (err) |
222 | goto failure; | |
223 | ||
877d1f62 | 224 | sk_set_txhash(sk); |
9e7ceb06 | 225 | |
da905bd1 | 226 | rt = ip_route_newports(fl4, rt, orig_sport, orig_dport, |
b23dd4fe DM |
227 | inet->inet_sport, inet->inet_dport, sk); |
228 | if (IS_ERR(rt)) { | |
229 | err = PTR_ERR(rt); | |
230 | rt = NULL; | |
1da177e4 | 231 | goto failure; |
b23dd4fe | 232 | } |
1da177e4 | 233 | /* OK, now commit destination to socket. */ |
bcd76111 | 234 | sk->sk_gso_type = SKB_GSO_TCPV4; |
d8d1f30b | 235 | sk_setup_caps(sk, &rt->dst); |
19f6d3f3 | 236 | rt = NULL; |
1da177e4 | 237 | |
00355fa5 AK |
238 | if (likely(!tp->repair)) { |
239 | seq = secure_tcp_sequence_number(inet->inet_saddr, | |
240 | inet->inet_daddr, | |
241 | inet->inet_sport, | |
242 | usin->sin_port, | |
243 | &tp->tsoffset); | |
244 | if (!tp->write_seq) | |
245 | tp->write_seq = seq; | |
246 | } | |
1da177e4 | 247 | |
c720c7e8 | 248 | inet->inet_id = tp->write_seq ^ jiffies; |
1da177e4 | 249 | |
19f6d3f3 WW |
250 | if (tcp_fastopen_defer_connect(sk, &err)) |
251 | return err; | |
252 | if (err) | |
253 | goto failure; | |
254 | ||
2b916477 | 255 | err = tcp_connect(sk); |
ee995283 | 256 | |
1da177e4 LT |
257 | if (err) |
258 | goto failure; | |
259 | ||
260 | return 0; | |
261 | ||
262 | failure: | |
7174259e ACM |
263 | /* |
264 | * This unhashes the socket and releases the local port, | |
265 | * if necessary. | |
266 | */ | |
1da177e4 LT |
267 | tcp_set_state(sk, TCP_CLOSE); |
268 | ip_rt_put(rt); | |
269 | sk->sk_route_caps = 0; | |
c720c7e8 | 270 | inet->inet_dport = 0; |
1da177e4 LT |
271 | return err; |
272 | } | |
4bc2f18b | 273 | EXPORT_SYMBOL(tcp_v4_connect); |
1da177e4 | 274 | |
1da177e4 | 275 | /* |
563d34d0 ED |
276 | * This routine reacts to ICMP_FRAG_NEEDED mtu indications as defined in RFC1191. |
277 | * It can be called through tcp_release_cb() if socket was owned by user | |
278 | * at the time tcp_v4_err() was called to handle ICMP message. | |
1da177e4 | 279 | */ |
4fab9071 | 280 | void tcp_v4_mtu_reduced(struct sock *sk) |
1da177e4 | 281 | { |
1da177e4 | 282 | struct inet_sock *inet = inet_sk(sk); |
02b2faaf ED |
283 | struct dst_entry *dst; |
284 | u32 mtu; | |
1da177e4 | 285 | |
02b2faaf ED |
286 | if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) |
287 | return; | |
288 | mtu = tcp_sk(sk)->mtu_info; | |
80d0a69f DM |
289 | dst = inet_csk_update_pmtu(sk, mtu); |
290 | if (!dst) | |
1da177e4 LT |
291 | return; |
292 | ||
1da177e4 LT |
293 | /* Something is about to be wrong... Remember soft error |
294 | * for the case, if this connection will not able to recover. | |
295 | */ | |
296 | if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst)) | |
297 | sk->sk_err_soft = EMSGSIZE; | |
298 | ||
299 | mtu = dst_mtu(dst); | |
300 | ||
301 | if (inet->pmtudisc != IP_PMTUDISC_DONT && | |
482fc609 | 302 | ip_sk_accept_pmtu(sk) && |
d83d8461 | 303 | inet_csk(sk)->icsk_pmtu_cookie > mtu) { |
1da177e4 LT |
304 | tcp_sync_mss(sk, mtu); |
305 | ||
306 | /* Resend the TCP packet because it's | |
307 | * clear that the old packet has been | |
308 | * dropped. This is the new "fast" path mtu | |
309 | * discovery. | |
310 | */ | |
311 | tcp_simple_retransmit(sk); | |
312 | } /* else let the usual retransmit timer handle it */ | |
313 | } | |
4fab9071 | 314 | EXPORT_SYMBOL(tcp_v4_mtu_reduced); |
1da177e4 | 315 | |
55be7a9c DM |
316 | static void do_redirect(struct sk_buff *skb, struct sock *sk) |
317 | { | |
318 | struct dst_entry *dst = __sk_dst_check(sk, 0); | |
319 | ||
1ed5c48f | 320 | if (dst) |
6700c270 | 321 | dst->ops->redirect(dst, sk, skb); |
55be7a9c DM |
322 | } |
323 | ||
26e37360 ED |
324 | |
325 | /* handle ICMP messages on TCP_NEW_SYN_RECV request sockets */ | |
9cf74903 | 326 | void tcp_req_err(struct sock *sk, u32 seq, bool abort) |
26e37360 ED |
327 | { |
328 | struct request_sock *req = inet_reqsk(sk); | |
329 | struct net *net = sock_net(sk); | |
330 | ||
331 | /* ICMPs are not backlogged, hence we cannot get | |
332 | * an established socket here. | |
333 | */ | |
26e37360 | 334 | if (seq != tcp_rsk(req)->snt_isn) { |
02a1d6e7 | 335 | __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); |
9cf74903 | 336 | } else if (abort) { |
26e37360 ED |
337 | /* |
338 | * Still in SYN_RECV, just remove it silently. | |
339 | * There is no good way to pass the error to the newly | |
340 | * created socket, and POSIX does not want network | |
341 | * errors returned from accept(). | |
342 | */ | |
c6973669 | 343 | inet_csk_reqsk_queue_drop(req->rsk_listener, req); |
9caad864 | 344 | tcp_listendrop(req->rsk_listener); |
26e37360 | 345 | } |
ef84d8ce | 346 | reqsk_put(req); |
26e37360 ED |
347 | } |
348 | EXPORT_SYMBOL(tcp_req_err); | |
349 | ||
1da177e4 LT |
350 | /* |
351 | * This routine is called by the ICMP module when it gets some | |
352 | * sort of error condition. If err < 0 then the socket should | |
353 | * be closed and the error returned to the user. If err > 0 | |
354 | * it's just the icmp type << 8 | icmp code. After adjustment | |
355 | * header points to the first 8 bytes of the tcp header. We need | |
356 | * to find the appropriate port. | |
357 | * | |
358 | * The locking strategy used here is very "optimistic". When | |
359 | * someone else accesses the socket the ICMP is just dropped | |
360 | * and for some paths there is no check at all. | |
361 | * A more general error queue to queue errors for later handling | |
362 | * is probably better. | |
363 | * | |
364 | */ | |
365 | ||
4d1a2d9e | 366 | void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) |
1da177e4 | 367 | { |
b71d1d42 | 368 | const struct iphdr *iph = (const struct iphdr *)icmp_skb->data; |
4d1a2d9e | 369 | struct tcphdr *th = (struct tcphdr *)(icmp_skb->data + (iph->ihl << 2)); |
f1ecd5d9 | 370 | struct inet_connection_sock *icsk; |
1da177e4 LT |
371 | struct tcp_sock *tp; |
372 | struct inet_sock *inet; | |
4d1a2d9e DL |
373 | const int type = icmp_hdr(icmp_skb)->type; |
374 | const int code = icmp_hdr(icmp_skb)->code; | |
1da177e4 | 375 | struct sock *sk; |
f1ecd5d9 | 376 | struct sk_buff *skb; |
0a672f74 YC |
377 | struct request_sock *fastopen; |
378 | __u32 seq, snd_una; | |
f1ecd5d9 | 379 | __u32 remaining; |
1da177e4 | 380 | int err; |
4d1a2d9e | 381 | struct net *net = dev_net(icmp_skb->dev); |
1da177e4 | 382 | |
26e37360 ED |
383 | sk = __inet_lookup_established(net, &tcp_hashinfo, iph->daddr, |
384 | th->dest, iph->saddr, ntohs(th->source), | |
385 | inet_iif(icmp_skb)); | |
1da177e4 | 386 | if (!sk) { |
5d3848bc | 387 | __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
388 | return; |
389 | } | |
390 | if (sk->sk_state == TCP_TIME_WAIT) { | |
9469c7b4 | 391 | inet_twsk_put(inet_twsk(sk)); |
1da177e4 LT |
392 | return; |
393 | } | |
26e37360 ED |
394 | seq = ntohl(th->seq); |
395 | if (sk->sk_state == TCP_NEW_SYN_RECV) | |
9cf74903 ED |
396 | return tcp_req_err(sk, seq, |
397 | type == ICMP_PARAMETERPROB || | |
398 | type == ICMP_TIME_EXCEEDED || | |
399 | (type == ICMP_DEST_UNREACH && | |
400 | (code == ICMP_NET_UNREACH || | |
401 | code == ICMP_HOST_UNREACH))); | |
1da177e4 LT |
402 | |
403 | bh_lock_sock(sk); | |
404 | /* If too many ICMPs get dropped on busy | |
405 | * servers this needs to be solved differently. | |
563d34d0 ED |
406 | * We do take care of PMTU discovery (RFC1191) special case : |
407 | * we can receive locally generated ICMP messages while socket is held. | |
1da177e4 | 408 | */ |
b74aa930 ED |
409 | if (sock_owned_by_user(sk)) { |
410 | if (!(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)) | |
02a1d6e7 | 411 | __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); |
b74aa930 | 412 | } |
1da177e4 LT |
413 | if (sk->sk_state == TCP_CLOSE) |
414 | goto out; | |
415 | ||
97e3ecd1 | 416 | if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { |
02a1d6e7 | 417 | __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); |
97e3ecd1 | 418 | goto out; |
419 | } | |
420 | ||
f1ecd5d9 | 421 | icsk = inet_csk(sk); |
1da177e4 | 422 | tp = tcp_sk(sk); |
0a672f74 YC |
423 | /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */ |
424 | fastopen = tp->fastopen_rsk; | |
425 | snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una; | |
1da177e4 | 426 | if (sk->sk_state != TCP_LISTEN && |
0a672f74 | 427 | !between(seq, snd_una, tp->snd_nxt)) { |
02a1d6e7 | 428 | __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); |
1da177e4 LT |
429 | goto out; |
430 | } | |
431 | ||
432 | switch (type) { | |
55be7a9c | 433 | case ICMP_REDIRECT: |
45caeaa5 JM |
434 | if (!sock_owned_by_user(sk)) |
435 | do_redirect(icmp_skb, sk); | |
55be7a9c | 436 | goto out; |
1da177e4 LT |
437 | case ICMP_SOURCE_QUENCH: |
438 | /* Just silently ignore these. */ | |
439 | goto out; | |
440 | case ICMP_PARAMETERPROB: | |
441 | err = EPROTO; | |
442 | break; | |
443 | case ICMP_DEST_UNREACH: | |
444 | if (code > NR_ICMP_UNREACH) | |
445 | goto out; | |
446 | ||
447 | if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ | |
0d4f0608 ED |
448 | /* We are not interested in TCP_LISTEN and open_requests |
449 | * (SYN-ACKs send out by Linux are always <576bytes so | |
450 | * they should go through unfragmented). | |
451 | */ | |
452 | if (sk->sk_state == TCP_LISTEN) | |
453 | goto out; | |
454 | ||
563d34d0 | 455 | tp->mtu_info = info; |
144d56e9 | 456 | if (!sock_owned_by_user(sk)) { |
563d34d0 | 457 | tcp_v4_mtu_reduced(sk); |
144d56e9 | 458 | } else { |
7aa5470c | 459 | if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, &sk->sk_tsq_flags)) |
144d56e9 ED |
460 | sock_hold(sk); |
461 | } | |
1da177e4 LT |
462 | goto out; |
463 | } | |
464 | ||
465 | err = icmp_err_convert[code].errno; | |
f1ecd5d9 DL |
466 | /* check if icmp_skb allows revert of backoff |
467 | * (see draft-zimmermann-tcp-lcd) */ | |
468 | if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH) | |
469 | break; | |
470 | if (seq != tp->snd_una || !icsk->icsk_retransmits || | |
0a672f74 | 471 | !icsk->icsk_backoff || fastopen) |
f1ecd5d9 DL |
472 | break; |
473 | ||
8f49c270 DM |
474 | if (sock_owned_by_user(sk)) |
475 | break; | |
476 | ||
f1ecd5d9 | 477 | icsk->icsk_backoff--; |
fcdd1cf4 ED |
478 | icsk->icsk_rto = tp->srtt_us ? __tcp_set_rto(tp) : |
479 | TCP_TIMEOUT_INIT; | |
480 | icsk->icsk_rto = inet_csk_rto_backoff(icsk, TCP_RTO_MAX); | |
f1ecd5d9 DL |
481 | |
482 | skb = tcp_write_queue_head(sk); | |
483 | BUG_ON(!skb); | |
484 | ||
7faee5c0 ED |
485 | remaining = icsk->icsk_rto - |
486 | min(icsk->icsk_rto, | |
487 | tcp_time_stamp - tcp_skb_timestamp(skb)); | |
f1ecd5d9 DL |
488 | |
489 | if (remaining) { | |
490 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, | |
491 | remaining, TCP_RTO_MAX); | |
f1ecd5d9 DL |
492 | } else { |
493 | /* RTO revert clocked out retransmission. | |
494 | * Will retransmit now */ | |
495 | tcp_retransmit_timer(sk); | |
496 | } | |
497 | ||
1da177e4 LT |
498 | break; |
499 | case ICMP_TIME_EXCEEDED: | |
500 | err = EHOSTUNREACH; | |
501 | break; | |
502 | default: | |
503 | goto out; | |
504 | } | |
505 | ||
506 | switch (sk->sk_state) { | |
1da177e4 | 507 | case TCP_SYN_SENT: |
0a672f74 YC |
508 | case TCP_SYN_RECV: |
509 | /* Only in fast or simultaneous open. If a fast open socket is | |
510 | * is already accepted it is treated as a connected one below. | |
511 | */ | |
51456b29 | 512 | if (fastopen && !fastopen->sk) |
0a672f74 YC |
513 | break; |
514 | ||
1da177e4 | 515 | if (!sock_owned_by_user(sk)) { |
1da177e4 LT |
516 | sk->sk_err = err; |
517 | ||
518 | sk->sk_error_report(sk); | |
519 | ||
520 | tcp_done(sk); | |
521 | } else { | |
522 | sk->sk_err_soft = err; | |
523 | } | |
524 | goto out; | |
525 | } | |
526 | ||
527 | /* If we've already connected we will keep trying | |
528 | * until we time out, or the user gives up. | |
529 | * | |
530 | * rfc1122 4.2.3.9 allows to consider as hard errors | |
531 | * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, | |
532 | * but it is obsoleted by pmtu discovery). | |
533 | * | |
534 | * Note, that in modern internet, where routing is unreliable | |
535 | * and in each dark corner broken firewalls sit, sending random | |
536 | * errors ordered by their masters even this two messages finally lose | |
537 | * their original sense (even Linux sends invalid PORT_UNREACHs) | |
538 | * | |
539 | * Now we are in compliance with RFCs. | |
540 | * --ANK (980905) | |
541 | */ | |
542 | ||
543 | inet = inet_sk(sk); | |
544 | if (!sock_owned_by_user(sk) && inet->recverr) { | |
545 | sk->sk_err = err; | |
546 | sk->sk_error_report(sk); | |
547 | } else { /* Only an error on timeout */ | |
548 | sk->sk_err_soft = err; | |
549 | } | |
550 | ||
551 | out: | |
552 | bh_unlock_sock(sk); | |
553 | sock_put(sk); | |
554 | } | |
555 | ||
28850dc7 | 556 | void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr) |
1da177e4 | 557 | { |
aa8223c7 | 558 | struct tcphdr *th = tcp_hdr(skb); |
1da177e4 | 559 | |
84fa7933 | 560 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
419f9f89 | 561 | th->check = ~tcp_v4_check(skb->len, saddr, daddr, 0); |
663ead3b | 562 | skb->csum_start = skb_transport_header(skb) - skb->head; |
ff1dcadb | 563 | skb->csum_offset = offsetof(struct tcphdr, check); |
1da177e4 | 564 | } else { |
419f9f89 | 565 | th->check = tcp_v4_check(skb->len, saddr, daddr, |
07f0757a | 566 | csum_partial(th, |
1da177e4 LT |
567 | th->doff << 2, |
568 | skb->csum)); | |
569 | } | |
570 | } | |
571 | ||
419f9f89 | 572 | /* This routine computes an IPv4 TCP checksum. */ |
bb296246 | 573 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb) |
419f9f89 | 574 | { |
cf533ea5 | 575 | const struct inet_sock *inet = inet_sk(sk); |
419f9f89 HX |
576 | |
577 | __tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr); | |
578 | } | |
4bc2f18b | 579 | EXPORT_SYMBOL(tcp_v4_send_check); |
419f9f89 | 580 | |
1da177e4 LT |
581 | /* |
582 | * This routine will send an RST to the other tcp. | |
583 | * | |
584 | * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.) | |
585 | * for reset. | |
586 | * Answer: if a packet caused RST, it is not for a socket | |
587 | * existing in our system, if it is matched to a socket, | |
588 | * it is just duplicate segment or bug in other side's TCP. | |
589 | * So that we build reply only basing on parameters | |
590 | * arrived with segment. | |
591 | * Exception: precedence violation. We do not implement it in any case. | |
592 | */ | |
593 | ||
a00e7444 | 594 | static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) |
1da177e4 | 595 | { |
cf533ea5 | 596 | const struct tcphdr *th = tcp_hdr(skb); |
cfb6eeb4 YH |
597 | struct { |
598 | struct tcphdr th; | |
599 | #ifdef CONFIG_TCP_MD5SIG | |
714e85be | 600 | __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)]; |
cfb6eeb4 YH |
601 | #endif |
602 | } rep; | |
1da177e4 | 603 | struct ip_reply_arg arg; |
cfb6eeb4 | 604 | #ifdef CONFIG_TCP_MD5SIG |
e46787f0 | 605 | struct tcp_md5sig_key *key = NULL; |
658ddaaf SL |
606 | const __u8 *hash_location = NULL; |
607 | unsigned char newhash[16]; | |
608 | int genhash; | |
609 | struct sock *sk1 = NULL; | |
cfb6eeb4 | 610 | #endif |
a86b1e30 | 611 | struct net *net; |
1da177e4 LT |
612 | |
613 | /* Never send a reset in response to a reset. */ | |
614 | if (th->rst) | |
615 | return; | |
616 | ||
c3658e8d ED |
617 | /* If sk not NULL, it means we did a successful lookup and incoming |
618 | * route had to be correct. prequeue might have dropped our dst. | |
619 | */ | |
620 | if (!sk && skb_rtable(skb)->rt_type != RTN_LOCAL) | |
1da177e4 LT |
621 | return; |
622 | ||
623 | /* Swap the send and the receive. */ | |
cfb6eeb4 YH |
624 | memset(&rep, 0, sizeof(rep)); |
625 | rep.th.dest = th->source; | |
626 | rep.th.source = th->dest; | |
627 | rep.th.doff = sizeof(struct tcphdr) / 4; | |
628 | rep.th.rst = 1; | |
1da177e4 LT |
629 | |
630 | if (th->ack) { | |
cfb6eeb4 | 631 | rep.th.seq = th->ack_seq; |
1da177e4 | 632 | } else { |
cfb6eeb4 YH |
633 | rep.th.ack = 1; |
634 | rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin + | |
635 | skb->len - (th->doff << 2)); | |
1da177e4 LT |
636 | } |
637 | ||
7174259e | 638 | memset(&arg, 0, sizeof(arg)); |
cfb6eeb4 YH |
639 | arg.iov[0].iov_base = (unsigned char *)&rep; |
640 | arg.iov[0].iov_len = sizeof(rep.th); | |
641 | ||
0f85feae | 642 | net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); |
cfb6eeb4 | 643 | #ifdef CONFIG_TCP_MD5SIG |
3b24d854 | 644 | rcu_read_lock(); |
658ddaaf | 645 | hash_location = tcp_parse_md5sig_option(th); |
271c3b9b | 646 | if (sk && sk_fullsock(sk)) { |
e46787f0 FW |
647 | key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *) |
648 | &ip_hdr(skb)->saddr, AF_INET); | |
649 | } else if (hash_location) { | |
658ddaaf SL |
650 | /* |
651 | * active side is lost. Try to find listening socket through | |
652 | * source port, and then find md5 key through listening socket. | |
653 | * we are not loose security here: | |
654 | * Incoming packet is checked with md5 hash with finding key, | |
655 | * no RST generated if md5 hash doesn't match. | |
656 | */ | |
a583636a CG |
657 | sk1 = __inet_lookup_listener(net, &tcp_hashinfo, NULL, 0, |
658 | ip_hdr(skb)->saddr, | |
da5e3630 | 659 | th->source, ip_hdr(skb)->daddr, |
658ddaaf SL |
660 | ntohs(th->source), inet_iif(skb)); |
661 | /* don't send rst if it can't find key */ | |
662 | if (!sk1) | |
3b24d854 ED |
663 | goto out; |
664 | ||
658ddaaf SL |
665 | key = tcp_md5_do_lookup(sk1, (union tcp_md5_addr *) |
666 | &ip_hdr(skb)->saddr, AF_INET); | |
667 | if (!key) | |
3b24d854 ED |
668 | goto out; |
669 | ||
658ddaaf | 670 | |
39f8e58e | 671 | genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb); |
658ddaaf | 672 | if (genhash || memcmp(hash_location, newhash, 16) != 0) |
3b24d854 ED |
673 | goto out; |
674 | ||
658ddaaf SL |
675 | } |
676 | ||
cfb6eeb4 YH |
677 | if (key) { |
678 | rep.opt[0] = htonl((TCPOPT_NOP << 24) | | |
679 | (TCPOPT_NOP << 16) | | |
680 | (TCPOPT_MD5SIG << 8) | | |
681 | TCPOLEN_MD5SIG); | |
682 | /* Update length and the length the header thinks exists */ | |
683 | arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; | |
684 | rep.th.doff = arg.iov[0].iov_len / 4; | |
685 | ||
49a72dfb | 686 | tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1], |
78e645cb IJ |
687 | key, ip_hdr(skb)->saddr, |
688 | ip_hdr(skb)->daddr, &rep.th); | |
cfb6eeb4 YH |
689 | } |
690 | #endif | |
eddc9ec5 ACM |
691 | arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, |
692 | ip_hdr(skb)->saddr, /* XXX */ | |
52cd5750 | 693 | arg.iov[0].iov_len, IPPROTO_TCP, 0); |
1da177e4 | 694 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; |
271c3b9b FW |
695 | arg.flags = (sk && inet_sk_transparent(sk)) ? IP_REPLY_ARG_NOSRCCHECK : 0; |
696 | ||
e2446eaa | 697 | /* When socket is gone, all binding information is lost. |
4c675258 AK |
698 | * routing might fail in this case. No choice here, if we choose to force |
699 | * input interface, we will misroute in case of asymmetric route. | |
e2446eaa | 700 | */ |
4c675258 AK |
701 | if (sk) |
702 | arg.bound_dev_if = sk->sk_bound_dev_if; | |
1da177e4 | 703 | |
271c3b9b FW |
704 | BUILD_BUG_ON(offsetof(struct sock, sk_bound_dev_if) != |
705 | offsetof(struct inet_timewait_sock, tw_bound_dev_if)); | |
706 | ||
66b13d99 | 707 | arg.tos = ip_hdr(skb)->tos; |
e2d118a1 | 708 | arg.uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL); |
47dcc20a | 709 | local_bh_disable(); |
bdbbb852 ED |
710 | ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk), |
711 | skb, &TCP_SKB_CB(skb)->header.h4.opt, | |
24a2d43d ED |
712 | ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, |
713 | &arg, arg.iov[0].iov_len); | |
1da177e4 | 714 | |
90bbcc60 ED |
715 | __TCP_INC_STATS(net, TCP_MIB_OUTSEGS); |
716 | __TCP_INC_STATS(net, TCP_MIB_OUTRSTS); | |
47dcc20a | 717 | local_bh_enable(); |
658ddaaf SL |
718 | |
719 | #ifdef CONFIG_TCP_MD5SIG | |
3b24d854 ED |
720 | out: |
721 | rcu_read_unlock(); | |
658ddaaf | 722 | #endif |
1da177e4 LT |
723 | } |
724 | ||
725 | /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states | |
726 | outside socket context is ugly, certainly. What can I do? | |
727 | */ | |
728 | ||
e2d118a1 | 729 | static void tcp_v4_send_ack(const struct sock *sk, |
e62a123b | 730 | struct sk_buff *skb, u32 seq, u32 ack, |
ee684b6f | 731 | u32 win, u32 tsval, u32 tsecr, int oif, |
88ef4a5a | 732 | struct tcp_md5sig_key *key, |
66b13d99 | 733 | int reply_flags, u8 tos) |
1da177e4 | 734 | { |
cf533ea5 | 735 | const struct tcphdr *th = tcp_hdr(skb); |
1da177e4 LT |
736 | struct { |
737 | struct tcphdr th; | |
714e85be | 738 | __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2) |
cfb6eeb4 | 739 | #ifdef CONFIG_TCP_MD5SIG |
714e85be | 740 | + (TCPOLEN_MD5SIG_ALIGNED >> 2) |
cfb6eeb4 YH |
741 | #endif |
742 | ]; | |
1da177e4 | 743 | } rep; |
e2d118a1 | 744 | struct net *net = sock_net(sk); |
1da177e4 LT |
745 | struct ip_reply_arg arg; |
746 | ||
747 | memset(&rep.th, 0, sizeof(struct tcphdr)); | |
7174259e | 748 | memset(&arg, 0, sizeof(arg)); |
1da177e4 LT |
749 | |
750 | arg.iov[0].iov_base = (unsigned char *)&rep; | |
751 | arg.iov[0].iov_len = sizeof(rep.th); | |
ee684b6f | 752 | if (tsecr) { |
cfb6eeb4 YH |
753 | rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
754 | (TCPOPT_TIMESTAMP << 8) | | |
755 | TCPOLEN_TIMESTAMP); | |
ee684b6f AV |
756 | rep.opt[1] = htonl(tsval); |
757 | rep.opt[2] = htonl(tsecr); | |
cb48cfe8 | 758 | arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED; |
1da177e4 LT |
759 | } |
760 | ||
761 | /* Swap the send and the receive. */ | |
762 | rep.th.dest = th->source; | |
763 | rep.th.source = th->dest; | |
764 | rep.th.doff = arg.iov[0].iov_len / 4; | |
765 | rep.th.seq = htonl(seq); | |
766 | rep.th.ack_seq = htonl(ack); | |
767 | rep.th.ack = 1; | |
768 | rep.th.window = htons(win); | |
769 | ||
cfb6eeb4 | 770 | #ifdef CONFIG_TCP_MD5SIG |
cfb6eeb4 | 771 | if (key) { |
ee684b6f | 772 | int offset = (tsecr) ? 3 : 0; |
cfb6eeb4 YH |
773 | |
774 | rep.opt[offset++] = htonl((TCPOPT_NOP << 24) | | |
775 | (TCPOPT_NOP << 16) | | |
776 | (TCPOPT_MD5SIG << 8) | | |
777 | TCPOLEN_MD5SIG); | |
778 | arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; | |
779 | rep.th.doff = arg.iov[0].iov_len/4; | |
780 | ||
49a72dfb | 781 | tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset], |
90b7e112 AL |
782 | key, ip_hdr(skb)->saddr, |
783 | ip_hdr(skb)->daddr, &rep.th); | |
cfb6eeb4 YH |
784 | } |
785 | #endif | |
88ef4a5a | 786 | arg.flags = reply_flags; |
eddc9ec5 ACM |
787 | arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, |
788 | ip_hdr(skb)->saddr, /* XXX */ | |
1da177e4 LT |
789 | arg.iov[0].iov_len, IPPROTO_TCP, 0); |
790 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; | |
9501f972 YH |
791 | if (oif) |
792 | arg.bound_dev_if = oif; | |
66b13d99 | 793 | arg.tos = tos; |
e2d118a1 | 794 | arg.uid = sock_net_uid(net, sk_fullsock(sk) ? sk : NULL); |
47dcc20a | 795 | local_bh_disable(); |
bdbbb852 ED |
796 | ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk), |
797 | skb, &TCP_SKB_CB(skb)->header.h4.opt, | |
24a2d43d ED |
798 | ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, |
799 | &arg, arg.iov[0].iov_len); | |
1da177e4 | 800 | |
90bbcc60 | 801 | __TCP_INC_STATS(net, TCP_MIB_OUTSEGS); |
47dcc20a | 802 | local_bh_enable(); |
1da177e4 LT |
803 | } |
804 | ||
805 | static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) | |
806 | { | |
8feaf0c0 | 807 | struct inet_timewait_sock *tw = inet_twsk(sk); |
cfb6eeb4 | 808 | struct tcp_timewait_sock *tcptw = tcp_twsk(sk); |
1da177e4 | 809 | |
e2d118a1 | 810 | tcp_v4_send_ack(sk, skb, |
e62a123b | 811 | tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, |
7174259e | 812 | tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, |
ee684b6f | 813 | tcp_time_stamp + tcptw->tw_ts_offset, |
9501f972 YH |
814 | tcptw->tw_ts_recent, |
815 | tw->tw_bound_dev_if, | |
88ef4a5a | 816 | tcp_twsk_md5_key(tcptw), |
66b13d99 ED |
817 | tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0, |
818 | tw->tw_tos | |
9501f972 | 819 | ); |
1da177e4 | 820 | |
8feaf0c0 | 821 | inet_twsk_put(tw); |
1da177e4 LT |
822 | } |
823 | ||
a00e7444 | 824 | static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, |
7174259e | 825 | struct request_sock *req) |
1da177e4 | 826 | { |
168a8f58 JC |
827 | /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV |
828 | * sk->sk_state == TCP_SYN_RECV -> for Fast Open. | |
829 | */ | |
e62a123b ED |
830 | u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 : |
831 | tcp_sk(sk)->snd_nxt; | |
832 | ||
20a2b49f ED |
833 | /* RFC 7323 2.3 |
834 | * The window field (SEG.WND) of every outgoing segment, with the | |
835 | * exception of <SYN> segments, MUST be right-shifted by | |
836 | * Rcv.Wind.Shift bits: | |
837 | */ | |
e2d118a1 | 838 | tcp_v4_send_ack(sk, skb, seq, |
20a2b49f ED |
839 | tcp_rsk(req)->rcv_nxt, |
840 | req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale, | |
95a22cae | 841 | tcp_time_stamp + tcp_rsk(req)->ts_off, |
9501f972 YH |
842 | req->ts_recent, |
843 | 0, | |
a915da9b ED |
844 | tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&ip_hdr(skb)->daddr, |
845 | AF_INET), | |
66b13d99 ED |
846 | inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0, |
847 | ip_hdr(skb)->tos); | |
1da177e4 LT |
848 | } |
849 | ||
1da177e4 | 850 | /* |
9bf1d83e | 851 | * Send a SYN-ACK after having received a SYN. |
60236fdd | 852 | * This still operates on a request_sock only, not on a big |
1da177e4 LT |
853 | * socket. |
854 | */ | |
0f935dbe | 855 | static int tcp_v4_send_synack(const struct sock *sk, struct dst_entry *dst, |
d6274bd8 | 856 | struct flowi *fl, |
72659ecc | 857 | struct request_sock *req, |
ca6fb065 | 858 | struct tcp_fastopen_cookie *foc, |
b3d05147 | 859 | enum tcp_synack_type synack_type) |
1da177e4 | 860 | { |
2e6599cb | 861 | const struct inet_request_sock *ireq = inet_rsk(req); |
6bd023f3 | 862 | struct flowi4 fl4; |
1da177e4 | 863 | int err = -1; |
d41db5af | 864 | struct sk_buff *skb; |
1da177e4 LT |
865 | |
866 | /* First, grab a route. */ | |
ba3f7f04 | 867 | if (!dst && (dst = inet_csk_route_req(sk, &fl4, req)) == NULL) |
fd80eb94 | 868 | return -1; |
1da177e4 | 869 | |
b3d05147 | 870 | skb = tcp_make_synack(sk, dst, req, foc, synack_type); |
1da177e4 LT |
871 | |
872 | if (skb) { | |
634fb979 | 873 | __tcp_v4_send_check(skb, ireq->ir_loc_addr, ireq->ir_rmt_addr); |
1da177e4 | 874 | |
634fb979 ED |
875 | err = ip_build_and_send_pkt(skb, sk, ireq->ir_loc_addr, |
876 | ireq->ir_rmt_addr, | |
2e6599cb | 877 | ireq->opt); |
b9df3cb8 | 878 | err = net_xmit_eval(err); |
1da177e4 LT |
879 | } |
880 | ||
1da177e4 LT |
881 | return err; |
882 | } | |
883 | ||
884 | /* | |
60236fdd | 885 | * IPv4 request_sock destructor. |
1da177e4 | 886 | */ |
60236fdd | 887 | static void tcp_v4_reqsk_destructor(struct request_sock *req) |
1da177e4 | 888 | { |
a51482bd | 889 | kfree(inet_rsk(req)->opt); |
1da177e4 LT |
890 | } |
891 | ||
cfb6eeb4 YH |
892 | #ifdef CONFIG_TCP_MD5SIG |
893 | /* | |
894 | * RFC2385 MD5 checksumming requires a mapping of | |
895 | * IP address->MD5 Key. | |
896 | * We need to maintain these in the sk structure. | |
897 | */ | |
898 | ||
899 | /* Find the Key structure for an address. */ | |
b83e3deb | 900 | struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk, |
a915da9b ED |
901 | const union tcp_md5_addr *addr, |
902 | int family) | |
cfb6eeb4 | 903 | { |
fd3a154a | 904 | const struct tcp_sock *tp = tcp_sk(sk); |
a915da9b | 905 | struct tcp_md5sig_key *key; |
a915da9b | 906 | unsigned int size = sizeof(struct in_addr); |
fd3a154a | 907 | const struct tcp_md5sig_info *md5sig; |
cfb6eeb4 | 908 | |
a8afca03 ED |
909 | /* caller either holds rcu_read_lock() or socket lock */ |
910 | md5sig = rcu_dereference_check(tp->md5sig_info, | |
1e1d04e6 | 911 | lockdep_sock_is_held(sk)); |
a8afca03 | 912 | if (!md5sig) |
cfb6eeb4 | 913 | return NULL; |
a915da9b ED |
914 | #if IS_ENABLED(CONFIG_IPV6) |
915 | if (family == AF_INET6) | |
916 | size = sizeof(struct in6_addr); | |
917 | #endif | |
b67bfe0d | 918 | hlist_for_each_entry_rcu(key, &md5sig->head, node) { |
a915da9b ED |
919 | if (key->family != family) |
920 | continue; | |
921 | if (!memcmp(&key->addr, addr, size)) | |
922 | return key; | |
cfb6eeb4 YH |
923 | } |
924 | return NULL; | |
925 | } | |
a915da9b | 926 | EXPORT_SYMBOL(tcp_md5_do_lookup); |
cfb6eeb4 | 927 | |
b83e3deb | 928 | struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, |
fd3a154a | 929 | const struct sock *addr_sk) |
cfb6eeb4 | 930 | { |
b52e6921 | 931 | const union tcp_md5_addr *addr; |
a915da9b | 932 | |
b52e6921 | 933 | addr = (const union tcp_md5_addr *)&addr_sk->sk_daddr; |
a915da9b | 934 | return tcp_md5_do_lookup(sk, addr, AF_INET); |
cfb6eeb4 | 935 | } |
cfb6eeb4 YH |
936 | EXPORT_SYMBOL(tcp_v4_md5_lookup); |
937 | ||
cfb6eeb4 | 938 | /* This can be called on a newly created socket, from other files */ |
a915da9b ED |
939 | int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
940 | int family, const u8 *newkey, u8 newkeylen, gfp_t gfp) | |
cfb6eeb4 YH |
941 | { |
942 | /* Add Key to the list */ | |
b0a713e9 | 943 | struct tcp_md5sig_key *key; |
cfb6eeb4 | 944 | struct tcp_sock *tp = tcp_sk(sk); |
a915da9b | 945 | struct tcp_md5sig_info *md5sig; |
cfb6eeb4 | 946 | |
c0353c7b | 947 | key = tcp_md5_do_lookup(sk, addr, family); |
cfb6eeb4 YH |
948 | if (key) { |
949 | /* Pre-existing entry - just update that one. */ | |
a915da9b | 950 | memcpy(key->key, newkey, newkeylen); |
b0a713e9 | 951 | key->keylen = newkeylen; |
a915da9b ED |
952 | return 0; |
953 | } | |
260fcbeb | 954 | |
a8afca03 | 955 | md5sig = rcu_dereference_protected(tp->md5sig_info, |
1e1d04e6 | 956 | lockdep_sock_is_held(sk)); |
a915da9b ED |
957 | if (!md5sig) { |
958 | md5sig = kmalloc(sizeof(*md5sig), gfp); | |
959 | if (!md5sig) | |
cfb6eeb4 | 960 | return -ENOMEM; |
cfb6eeb4 | 961 | |
a915da9b ED |
962 | sk_nocaps_add(sk, NETIF_F_GSO_MASK); |
963 | INIT_HLIST_HEAD(&md5sig->head); | |
a8afca03 | 964 | rcu_assign_pointer(tp->md5sig_info, md5sig); |
a915da9b | 965 | } |
cfb6eeb4 | 966 | |
5f3d9cb2 | 967 | key = sock_kmalloc(sk, sizeof(*key), gfp); |
a915da9b ED |
968 | if (!key) |
969 | return -ENOMEM; | |
71cea17e | 970 | if (!tcp_alloc_md5sig_pool()) { |
5f3d9cb2 | 971 | sock_kfree_s(sk, key, sizeof(*key)); |
a915da9b | 972 | return -ENOMEM; |
cfb6eeb4 | 973 | } |
a915da9b ED |
974 | |
975 | memcpy(key->key, newkey, newkeylen); | |
976 | key->keylen = newkeylen; | |
977 | key->family = family; | |
978 | memcpy(&key->addr, addr, | |
979 | (family == AF_INET6) ? sizeof(struct in6_addr) : | |
980 | sizeof(struct in_addr)); | |
981 | hlist_add_head_rcu(&key->node, &md5sig->head); | |
cfb6eeb4 YH |
982 | return 0; |
983 | } | |
a915da9b | 984 | EXPORT_SYMBOL(tcp_md5_do_add); |
cfb6eeb4 | 985 | |
a915da9b | 986 | int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family) |
cfb6eeb4 | 987 | { |
a915da9b ED |
988 | struct tcp_md5sig_key *key; |
989 | ||
c0353c7b | 990 | key = tcp_md5_do_lookup(sk, addr, family); |
a915da9b ED |
991 | if (!key) |
992 | return -ENOENT; | |
993 | hlist_del_rcu(&key->node); | |
5f3d9cb2 | 994 | atomic_sub(sizeof(*key), &sk->sk_omem_alloc); |
a915da9b | 995 | kfree_rcu(key, rcu); |
a915da9b | 996 | return 0; |
cfb6eeb4 | 997 | } |
a915da9b | 998 | EXPORT_SYMBOL(tcp_md5_do_del); |
cfb6eeb4 | 999 | |
e0683e70 | 1000 | static void tcp_clear_md5_list(struct sock *sk) |
cfb6eeb4 YH |
1001 | { |
1002 | struct tcp_sock *tp = tcp_sk(sk); | |
a915da9b | 1003 | struct tcp_md5sig_key *key; |
b67bfe0d | 1004 | struct hlist_node *n; |
a8afca03 | 1005 | struct tcp_md5sig_info *md5sig; |
cfb6eeb4 | 1006 | |
a8afca03 ED |
1007 | md5sig = rcu_dereference_protected(tp->md5sig_info, 1); |
1008 | ||
b67bfe0d | 1009 | hlist_for_each_entry_safe(key, n, &md5sig->head, node) { |
a915da9b | 1010 | hlist_del_rcu(&key->node); |
5f3d9cb2 | 1011 | atomic_sub(sizeof(*key), &sk->sk_omem_alloc); |
a915da9b | 1012 | kfree_rcu(key, rcu); |
cfb6eeb4 YH |
1013 | } |
1014 | } | |
1015 | ||
7174259e ACM |
1016 | static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval, |
1017 | int optlen) | |
cfb6eeb4 YH |
1018 | { |
1019 | struct tcp_md5sig cmd; | |
1020 | struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr; | |
cfb6eeb4 YH |
1021 | |
1022 | if (optlen < sizeof(cmd)) | |
1023 | return -EINVAL; | |
1024 | ||
7174259e | 1025 | if (copy_from_user(&cmd, optval, sizeof(cmd))) |
cfb6eeb4 YH |
1026 | return -EFAULT; |
1027 | ||
1028 | if (sin->sin_family != AF_INET) | |
1029 | return -EINVAL; | |
1030 | ||
64a124ed | 1031 | if (!cmd.tcpm_keylen) |
a915da9b ED |
1032 | return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr, |
1033 | AF_INET); | |
cfb6eeb4 YH |
1034 | |
1035 | if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) | |
1036 | return -EINVAL; | |
1037 | ||
a915da9b ED |
1038 | return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr, |
1039 | AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, | |
1040 | GFP_KERNEL); | |
cfb6eeb4 YH |
1041 | } |
1042 | ||
19689e38 ED |
1043 | static int tcp_v4_md5_hash_headers(struct tcp_md5sig_pool *hp, |
1044 | __be32 daddr, __be32 saddr, | |
1045 | const struct tcphdr *th, int nbytes) | |
cfb6eeb4 | 1046 | { |
cfb6eeb4 | 1047 | struct tcp4_pseudohdr *bp; |
49a72dfb | 1048 | struct scatterlist sg; |
19689e38 | 1049 | struct tcphdr *_th; |
cfb6eeb4 | 1050 | |
19689e38 | 1051 | bp = hp->scratch; |
cfb6eeb4 YH |
1052 | bp->saddr = saddr; |
1053 | bp->daddr = daddr; | |
1054 | bp->pad = 0; | |
076fb722 | 1055 | bp->protocol = IPPROTO_TCP; |
49a72dfb | 1056 | bp->len = cpu_to_be16(nbytes); |
c7da57a1 | 1057 | |
19689e38 ED |
1058 | _th = (struct tcphdr *)(bp + 1); |
1059 | memcpy(_th, th, sizeof(*th)); | |
1060 | _th->check = 0; | |
1061 | ||
1062 | sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th)); | |
1063 | ahash_request_set_crypt(hp->md5_req, &sg, NULL, | |
1064 | sizeof(*bp) + sizeof(*th)); | |
cf80e0e4 | 1065 | return crypto_ahash_update(hp->md5_req); |
49a72dfb AL |
1066 | } |
1067 | ||
a915da9b | 1068 | static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, |
318cf7aa | 1069 | __be32 daddr, __be32 saddr, const struct tcphdr *th) |
49a72dfb AL |
1070 | { |
1071 | struct tcp_md5sig_pool *hp; | |
cf80e0e4 | 1072 | struct ahash_request *req; |
49a72dfb AL |
1073 | |
1074 | hp = tcp_get_md5sig_pool(); | |
1075 | if (!hp) | |
1076 | goto clear_hash_noput; | |
cf80e0e4 | 1077 | req = hp->md5_req; |
49a72dfb | 1078 | |
cf80e0e4 | 1079 | if (crypto_ahash_init(req)) |
49a72dfb | 1080 | goto clear_hash; |
19689e38 | 1081 | if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2)) |
49a72dfb AL |
1082 | goto clear_hash; |
1083 | if (tcp_md5_hash_key(hp, key)) | |
1084 | goto clear_hash; | |
cf80e0e4 HX |
1085 | ahash_request_set_crypt(req, NULL, md5_hash, 0); |
1086 | if (crypto_ahash_final(req)) | |
cfb6eeb4 YH |
1087 | goto clear_hash; |
1088 | ||
cfb6eeb4 | 1089 | tcp_put_md5sig_pool(); |
cfb6eeb4 | 1090 | return 0; |
49a72dfb | 1091 | |
cfb6eeb4 YH |
1092 | clear_hash: |
1093 | tcp_put_md5sig_pool(); | |
1094 | clear_hash_noput: | |
1095 | memset(md5_hash, 0, 16); | |
49a72dfb | 1096 | return 1; |
cfb6eeb4 YH |
1097 | } |
1098 | ||
39f8e58e ED |
1099 | int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, |
1100 | const struct sock *sk, | |
318cf7aa | 1101 | const struct sk_buff *skb) |
cfb6eeb4 | 1102 | { |
49a72dfb | 1103 | struct tcp_md5sig_pool *hp; |
cf80e0e4 | 1104 | struct ahash_request *req; |
318cf7aa | 1105 | const struct tcphdr *th = tcp_hdr(skb); |
cfb6eeb4 YH |
1106 | __be32 saddr, daddr; |
1107 | ||
39f8e58e ED |
1108 | if (sk) { /* valid for establish/request sockets */ |
1109 | saddr = sk->sk_rcv_saddr; | |
1110 | daddr = sk->sk_daddr; | |
cfb6eeb4 | 1111 | } else { |
49a72dfb AL |
1112 | const struct iphdr *iph = ip_hdr(skb); |
1113 | saddr = iph->saddr; | |
1114 | daddr = iph->daddr; | |
cfb6eeb4 | 1115 | } |
49a72dfb AL |
1116 | |
1117 | hp = tcp_get_md5sig_pool(); | |
1118 | if (!hp) | |
1119 | goto clear_hash_noput; | |
cf80e0e4 | 1120 | req = hp->md5_req; |
49a72dfb | 1121 | |
cf80e0e4 | 1122 | if (crypto_ahash_init(req)) |
49a72dfb AL |
1123 | goto clear_hash; |
1124 | ||
19689e38 | 1125 | if (tcp_v4_md5_hash_headers(hp, daddr, saddr, th, skb->len)) |
49a72dfb AL |
1126 | goto clear_hash; |
1127 | if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2)) | |
1128 | goto clear_hash; | |
1129 | if (tcp_md5_hash_key(hp, key)) | |
1130 | goto clear_hash; | |
cf80e0e4 HX |
1131 | ahash_request_set_crypt(req, NULL, md5_hash, 0); |
1132 | if (crypto_ahash_final(req)) | |
49a72dfb AL |
1133 | goto clear_hash; |
1134 | ||
1135 | tcp_put_md5sig_pool(); | |
1136 | return 0; | |
1137 | ||
1138 | clear_hash: | |
1139 | tcp_put_md5sig_pool(); | |
1140 | clear_hash_noput: | |
1141 | memset(md5_hash, 0, 16); | |
1142 | return 1; | |
cfb6eeb4 | 1143 | } |
49a72dfb | 1144 | EXPORT_SYMBOL(tcp_v4_md5_hash_skb); |
cfb6eeb4 | 1145 | |
ba8e275a ED |
1146 | #endif |
1147 | ||
ff74e23f | 1148 | /* Called with rcu_read_lock() */ |
ba8e275a | 1149 | static bool tcp_v4_inbound_md5_hash(const struct sock *sk, |
ff74e23f | 1150 | const struct sk_buff *skb) |
cfb6eeb4 | 1151 | { |
ba8e275a | 1152 | #ifdef CONFIG_TCP_MD5SIG |
cfb6eeb4 YH |
1153 | /* |
1154 | * This gets called for each TCP segment that arrives | |
1155 | * so we want to be efficient. | |
1156 | * We have 3 drop cases: | |
1157 | * o No MD5 hash and one expected. | |
1158 | * o MD5 hash and we're not expecting one. | |
1159 | * o MD5 hash and its wrong. | |
1160 | */ | |
cf533ea5 | 1161 | const __u8 *hash_location = NULL; |
cfb6eeb4 | 1162 | struct tcp_md5sig_key *hash_expected; |
eddc9ec5 | 1163 | const struct iphdr *iph = ip_hdr(skb); |
cf533ea5 | 1164 | const struct tcphdr *th = tcp_hdr(skb); |
cfb6eeb4 | 1165 | int genhash; |
cfb6eeb4 YH |
1166 | unsigned char newhash[16]; |
1167 | ||
a915da9b ED |
1168 | hash_expected = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&iph->saddr, |
1169 | AF_INET); | |
7d5d5525 | 1170 | hash_location = tcp_parse_md5sig_option(th); |
cfb6eeb4 | 1171 | |
cfb6eeb4 YH |
1172 | /* We've parsed the options - do we have a hash? */ |
1173 | if (!hash_expected && !hash_location) | |
a2a385d6 | 1174 | return false; |
cfb6eeb4 YH |
1175 | |
1176 | if (hash_expected && !hash_location) { | |
c10d9310 | 1177 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); |
a2a385d6 | 1178 | return true; |
cfb6eeb4 YH |
1179 | } |
1180 | ||
1181 | if (!hash_expected && hash_location) { | |
c10d9310 | 1182 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); |
a2a385d6 | 1183 | return true; |
cfb6eeb4 YH |
1184 | } |
1185 | ||
1186 | /* Okay, so this is hash_expected and hash_location - | |
1187 | * so we need to calculate the checksum. | |
1188 | */ | |
49a72dfb AL |
1189 | genhash = tcp_v4_md5_hash_skb(newhash, |
1190 | hash_expected, | |
39f8e58e | 1191 | NULL, skb); |
cfb6eeb4 YH |
1192 | |
1193 | if (genhash || memcmp(hash_location, newhash, 16) != 0) { | |
72145a68 | 1194 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE); |
e87cc472 JP |
1195 | net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n", |
1196 | &iph->saddr, ntohs(th->source), | |
1197 | &iph->daddr, ntohs(th->dest), | |
1198 | genhash ? " tcp_v4_calc_md5_hash failed" | |
1199 | : ""); | |
a2a385d6 | 1200 | return true; |
cfb6eeb4 | 1201 | } |
a2a385d6 | 1202 | return false; |
cfb6eeb4 | 1203 | #endif |
ba8e275a ED |
1204 | return false; |
1205 | } | |
cfb6eeb4 | 1206 | |
b40cf18e ED |
1207 | static void tcp_v4_init_req(struct request_sock *req, |
1208 | const struct sock *sk_listener, | |
16bea70a OP |
1209 | struct sk_buff *skb) |
1210 | { | |
1211 | struct inet_request_sock *ireq = inet_rsk(req); | |
1212 | ||
08d2cc3b ED |
1213 | sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr); |
1214 | sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr); | |
16bea70a OP |
1215 | ireq->opt = tcp_v4_save_options(skb); |
1216 | } | |
1217 | ||
f964629e ED |
1218 | static struct dst_entry *tcp_v4_route_req(const struct sock *sk, |
1219 | struct flowi *fl, | |
d94e0417 OP |
1220 | const struct request_sock *req, |
1221 | bool *strict) | |
1222 | { | |
1223 | struct dst_entry *dst = inet_csk_route_req(sk, &fl->u.ip4, req); | |
1224 | ||
1225 | if (strict) { | |
1226 | if (fl->u.ip4.daddr == inet_rsk(req)->ir_rmt_addr) | |
1227 | *strict = true; | |
1228 | else | |
1229 | *strict = false; | |
1230 | } | |
1231 | ||
1232 | return dst; | |
1233 | } | |
1234 | ||
72a3effa | 1235 | struct request_sock_ops tcp_request_sock_ops __read_mostly = { |
1da177e4 | 1236 | .family = PF_INET, |
2e6599cb | 1237 | .obj_size = sizeof(struct tcp_request_sock), |
5db92c99 | 1238 | .rtx_syn_ack = tcp_rtx_synack, |
60236fdd ACM |
1239 | .send_ack = tcp_v4_reqsk_send_ack, |
1240 | .destructor = tcp_v4_reqsk_destructor, | |
1da177e4 | 1241 | .send_reset = tcp_v4_send_reset, |
688d1945 | 1242 | .syn_ack_timeout = tcp_syn_ack_timeout, |
1da177e4 LT |
1243 | }; |
1244 | ||
b2e4b3de | 1245 | static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = { |
2aec4a29 | 1246 | .mss_clamp = TCP_MSS_DEFAULT, |
16bea70a | 1247 | #ifdef CONFIG_TCP_MD5SIG |
fd3a154a | 1248 | .req_md5_lookup = tcp_v4_md5_lookup, |
e3afe7b7 | 1249 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
b6332e6c | 1250 | #endif |
16bea70a | 1251 | .init_req = tcp_v4_init_req, |
fb7b37a7 OP |
1252 | #ifdef CONFIG_SYN_COOKIES |
1253 | .cookie_init_seq = cookie_v4_init_sequence, | |
1254 | #endif | |
d94e0417 | 1255 | .route_req = tcp_v4_route_req, |
936b8bdb | 1256 | .init_seq = tcp_v4_init_sequence, |
d6274bd8 | 1257 | .send_synack = tcp_v4_send_synack, |
16bea70a | 1258 | }; |
cfb6eeb4 | 1259 | |
1da177e4 LT |
1260 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) |
1261 | { | |
1da177e4 | 1262 | /* Never answer to SYNs send to broadcast or multicast */ |
511c3f92 | 1263 | if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) |
1da177e4 LT |
1264 | goto drop; |
1265 | ||
1fb6f159 OP |
1266 | return tcp_conn_request(&tcp_request_sock_ops, |
1267 | &tcp_request_sock_ipv4_ops, sk, skb); | |
1da177e4 | 1268 | |
1da177e4 | 1269 | drop: |
9caad864 | 1270 | tcp_listendrop(sk); |
1da177e4 LT |
1271 | return 0; |
1272 | } | |
4bc2f18b | 1273 | EXPORT_SYMBOL(tcp_v4_conn_request); |
1da177e4 LT |
1274 | |
1275 | ||
1276 | /* | |
1277 | * The three way handshake has completed - we got a valid synack - | |
1278 | * now create the new socket. | |
1279 | */ | |
0c27171e | 1280 | struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, |
60236fdd | 1281 | struct request_sock *req, |
5e0724d0 ED |
1282 | struct dst_entry *dst, |
1283 | struct request_sock *req_unhash, | |
1284 | bool *own_req) | |
1da177e4 | 1285 | { |
2e6599cb | 1286 | struct inet_request_sock *ireq; |
1da177e4 LT |
1287 | struct inet_sock *newinet; |
1288 | struct tcp_sock *newtp; | |
1289 | struct sock *newsk; | |
cfb6eeb4 YH |
1290 | #ifdef CONFIG_TCP_MD5SIG |
1291 | struct tcp_md5sig_key *key; | |
1292 | #endif | |
f6d8bd05 | 1293 | struct ip_options_rcu *inet_opt; |
1da177e4 LT |
1294 | |
1295 | if (sk_acceptq_is_full(sk)) | |
1296 | goto exit_overflow; | |
1297 | ||
1da177e4 LT |
1298 | newsk = tcp_create_openreq_child(sk, req, skb); |
1299 | if (!newsk) | |
093d2823 | 1300 | goto exit_nonewsk; |
1da177e4 | 1301 | |
bcd76111 | 1302 | newsk->sk_gso_type = SKB_GSO_TCPV4; |
fae6ef87 | 1303 | inet_sk_rx_dst_set(newsk, skb); |
1da177e4 LT |
1304 | |
1305 | newtp = tcp_sk(newsk); | |
1306 | newinet = inet_sk(newsk); | |
2e6599cb | 1307 | ireq = inet_rsk(req); |
d1e559d0 ED |
1308 | sk_daddr_set(newsk, ireq->ir_rmt_addr); |
1309 | sk_rcv_saddr_set(newsk, ireq->ir_loc_addr); | |
6dd9a14e | 1310 | newsk->sk_bound_dev_if = ireq->ir_iif; |
634fb979 | 1311 | newinet->inet_saddr = ireq->ir_loc_addr; |
f6d8bd05 ED |
1312 | inet_opt = ireq->opt; |
1313 | rcu_assign_pointer(newinet->inet_opt, inet_opt); | |
2e6599cb | 1314 | ireq->opt = NULL; |
463c84b9 | 1315 | newinet->mc_index = inet_iif(skb); |
eddc9ec5 | 1316 | newinet->mc_ttl = ip_hdr(skb)->ttl; |
4c507d28 | 1317 | newinet->rcv_tos = ip_hdr(skb)->tos; |
d83d8461 | 1318 | inet_csk(newsk)->icsk_ext_hdr_len = 0; |
f6d8bd05 ED |
1319 | if (inet_opt) |
1320 | inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen; | |
c720c7e8 | 1321 | newinet->inet_id = newtp->write_seq ^ jiffies; |
1da177e4 | 1322 | |
dfd25fff ED |
1323 | if (!dst) { |
1324 | dst = inet_csk_route_child_sock(sk, newsk, req); | |
1325 | if (!dst) | |
1326 | goto put_and_exit; | |
1327 | } else { | |
1328 | /* syncookie case : see end of cookie_v4_check() */ | |
1329 | } | |
0e734419 DM |
1330 | sk_setup_caps(newsk, dst); |
1331 | ||
81164413 DB |
1332 | tcp_ca_openreq_child(newsk, dst); |
1333 | ||
1da177e4 | 1334 | tcp_sync_mss(newsk, dst_mtu(dst)); |
3541f9e8 | 1335 | newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst)); |
f5fff5dc | 1336 | |
1da177e4 LT |
1337 | tcp_initialize_rcv_mss(newsk); |
1338 | ||
cfb6eeb4 YH |
1339 | #ifdef CONFIG_TCP_MD5SIG |
1340 | /* Copy over the MD5 key from the original socket */ | |
a915da9b ED |
1341 | key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&newinet->inet_daddr, |
1342 | AF_INET); | |
00db4124 | 1343 | if (key) { |
cfb6eeb4 YH |
1344 | /* |
1345 | * We're using one, so create a matching key | |
1346 | * on the newsk structure. If we fail to get | |
1347 | * memory, then we end up not copying the key | |
1348 | * across. Shucks. | |
1349 | */ | |
a915da9b ED |
1350 | tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newinet->inet_daddr, |
1351 | AF_INET, key->key, key->keylen, GFP_ATOMIC); | |
a465419b | 1352 | sk_nocaps_add(newsk, NETIF_F_GSO_MASK); |
cfb6eeb4 YH |
1353 | } |
1354 | #endif | |
1355 | ||
0e734419 DM |
1356 | if (__inet_inherit_port(sk, newsk) < 0) |
1357 | goto put_and_exit; | |
5e0724d0 | 1358 | *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash)); |
805c4bc0 | 1359 | if (*own_req) |
49a496c9 | 1360 | tcp_move_syn(newtp, req); |
1da177e4 LT |
1361 | |
1362 | return newsk; | |
1363 | ||
1364 | exit_overflow: | |
c10d9310 | 1365 | NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); |
093d2823 BS |
1366 | exit_nonewsk: |
1367 | dst_release(dst); | |
1da177e4 | 1368 | exit: |
9caad864 | 1369 | tcp_listendrop(sk); |
1da177e4 | 1370 | return NULL; |
0e734419 | 1371 | put_and_exit: |
e337e24d CP |
1372 | inet_csk_prepare_forced_close(newsk); |
1373 | tcp_done(newsk); | |
0e734419 | 1374 | goto exit; |
1da177e4 | 1375 | } |
4bc2f18b | 1376 | EXPORT_SYMBOL(tcp_v4_syn_recv_sock); |
1da177e4 | 1377 | |
079096f1 | 1378 | static struct sock *tcp_v4_cookie_check(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 1379 | { |
079096f1 | 1380 | #ifdef CONFIG_SYN_COOKIES |
52452c54 | 1381 | const struct tcphdr *th = tcp_hdr(skb); |
1da177e4 | 1382 | |
af9b4738 | 1383 | if (!th->syn) |
461b74c3 | 1384 | sk = cookie_v4_check(sk, skb); |
1da177e4 LT |
1385 | #endif |
1386 | return sk; | |
1387 | } | |
1388 | ||
1da177e4 | 1389 | /* The socket must have it's spinlock held when we get |
e994b2f0 | 1390 | * here, unless it is a TCP_LISTEN socket. |
1da177e4 LT |
1391 | * |
1392 | * We have a potential double-lock case here, so even when | |
1393 | * doing backlog processing we use the BH locking scheme. | |
1394 | * This is because we cannot sleep with the original spinlock | |
1395 | * held. | |
1396 | */ | |
1397 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) | |
1398 | { | |
cfb6eeb4 | 1399 | struct sock *rsk; |
cfb6eeb4 | 1400 | |
1da177e4 | 1401 | if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ |
404e0a8b ED |
1402 | struct dst_entry *dst = sk->sk_rx_dst; |
1403 | ||
bdeab991 | 1404 | sock_rps_save_rxhash(sk, skb); |
3d97379a | 1405 | sk_mark_napi_id(sk, skb); |
404e0a8b | 1406 | if (dst) { |
505fbcf0 | 1407 | if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif || |
51456b29 | 1408 | !dst->ops->check(dst, 0)) { |
92101b3b DM |
1409 | dst_release(dst); |
1410 | sk->sk_rx_dst = NULL; | |
1411 | } | |
1412 | } | |
c995ae22 | 1413 | tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len); |
1da177e4 LT |
1414 | return 0; |
1415 | } | |
1416 | ||
12e25e10 | 1417 | if (tcp_checksum_complete(skb)) |
1da177e4 LT |
1418 | goto csum_err; |
1419 | ||
1420 | if (sk->sk_state == TCP_LISTEN) { | |
079096f1 ED |
1421 | struct sock *nsk = tcp_v4_cookie_check(sk, skb); |
1422 | ||
1da177e4 LT |
1423 | if (!nsk) |
1424 | goto discard; | |
1da177e4 | 1425 | if (nsk != sk) { |
bdeab991 | 1426 | sock_rps_save_rxhash(nsk, skb); |
38cb5245 | 1427 | sk_mark_napi_id(nsk, skb); |
cfb6eeb4 YH |
1428 | if (tcp_child_process(sk, nsk, skb)) { |
1429 | rsk = nsk; | |
1da177e4 | 1430 | goto reset; |
cfb6eeb4 | 1431 | } |
1da177e4 LT |
1432 | return 0; |
1433 | } | |
ca55158c | 1434 | } else |
bdeab991 | 1435 | sock_rps_save_rxhash(sk, skb); |
ca55158c | 1436 | |
72ab4a86 | 1437 | if (tcp_rcv_state_process(sk, skb)) { |
cfb6eeb4 | 1438 | rsk = sk; |
1da177e4 | 1439 | goto reset; |
cfb6eeb4 | 1440 | } |
1da177e4 LT |
1441 | return 0; |
1442 | ||
1443 | reset: | |
cfb6eeb4 | 1444 | tcp_v4_send_reset(rsk, skb); |
1da177e4 LT |
1445 | discard: |
1446 | kfree_skb(skb); | |
1447 | /* Be careful here. If this function gets more complicated and | |
1448 | * gcc suffers from register pressure on the x86, sk (in %ebx) | |
1449 | * might be destroyed here. This current version compiles correctly, | |
1450 | * but you have been warned. | |
1451 | */ | |
1452 | return 0; | |
1453 | ||
1454 | csum_err: | |
c10d9310 ED |
1455 | TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); |
1456 | TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); | |
1da177e4 LT |
1457 | goto discard; |
1458 | } | |
4bc2f18b | 1459 | EXPORT_SYMBOL(tcp_v4_do_rcv); |
1da177e4 | 1460 | |
160eb5a6 | 1461 | void tcp_v4_early_demux(struct sk_buff *skb) |
41063e9d | 1462 | { |
41063e9d DM |
1463 | const struct iphdr *iph; |
1464 | const struct tcphdr *th; | |
1465 | struct sock *sk; | |
41063e9d | 1466 | |
41063e9d | 1467 | if (skb->pkt_type != PACKET_HOST) |
160eb5a6 | 1468 | return; |
41063e9d | 1469 | |
45f00f99 | 1470 | if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr))) |
160eb5a6 | 1471 | return; |
41063e9d DM |
1472 | |
1473 | iph = ip_hdr(skb); | |
45f00f99 | 1474 | th = tcp_hdr(skb); |
41063e9d DM |
1475 | |
1476 | if (th->doff < sizeof(struct tcphdr) / 4) | |
160eb5a6 | 1477 | return; |
41063e9d | 1478 | |
45f00f99 | 1479 | sk = __inet_lookup_established(dev_net(skb->dev), &tcp_hashinfo, |
41063e9d | 1480 | iph->saddr, th->source, |
7011d085 | 1481 | iph->daddr, ntohs(th->dest), |
9cb429d6 | 1482 | skb->skb_iif); |
41063e9d DM |
1483 | if (sk) { |
1484 | skb->sk = sk; | |
1485 | skb->destructor = sock_edemux; | |
f7e4eb03 | 1486 | if (sk_fullsock(sk)) { |
d0c294c5 | 1487 | struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst); |
505fbcf0 | 1488 | |
41063e9d DM |
1489 | if (dst) |
1490 | dst = dst_check(dst, 0); | |
92101b3b | 1491 | if (dst && |
505fbcf0 | 1492 | inet_sk(sk)->rx_dst_ifindex == skb->skb_iif) |
92101b3b | 1493 | skb_dst_set_noref(skb, dst); |
41063e9d DM |
1494 | } |
1495 | } | |
41063e9d DM |
1496 | } |
1497 | ||
b2fb4f54 ED |
1498 | /* Packet is added to VJ-style prequeue for processing in process |
1499 | * context, if a reader task is waiting. Apparently, this exciting | |
1500 | * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93) | |
1501 | * failed somewhere. Latency? Burstiness? Well, at least now we will | |
1502 | * see, why it failed. 8)8) --ANK | |
1503 | * | |
1504 | */ | |
1505 | bool tcp_prequeue(struct sock *sk, struct sk_buff *skb) | |
1506 | { | |
1507 | struct tcp_sock *tp = tcp_sk(sk); | |
1508 | ||
1509 | if (sysctl_tcp_low_latency || !tp->ucopy.task) | |
1510 | return false; | |
1511 | ||
1512 | if (skb->len <= tcp_hdrlen(skb) && | |
1513 | skb_queue_len(&tp->ucopy.prequeue) == 0) | |
1514 | return false; | |
1515 | ||
ca777eff ED |
1516 | /* Before escaping RCU protected region, we need to take care of skb |
1517 | * dst. Prequeue is only enabled for established sockets. | |
1518 | * For such sockets, we might need the skb dst only to set sk->sk_rx_dst | |
1519 | * Instead of doing full sk_rx_dst validity here, let's perform | |
1520 | * an optimistic check. | |
1521 | */ | |
1522 | if (likely(sk->sk_rx_dst)) | |
1523 | skb_dst_drop(skb); | |
1524 | else | |
5037e9ef | 1525 | skb_dst_force_safe(skb); |
ca777eff | 1526 | |
b2fb4f54 ED |
1527 | __skb_queue_tail(&tp->ucopy.prequeue, skb); |
1528 | tp->ucopy.memory += skb->truesize; | |
0cef6a4c ED |
1529 | if (skb_queue_len(&tp->ucopy.prequeue) >= 32 || |
1530 | tp->ucopy.memory + atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) { | |
b2fb4f54 ED |
1531 | struct sk_buff *skb1; |
1532 | ||
1533 | BUG_ON(sock_owned_by_user(sk)); | |
0cef6a4c ED |
1534 | __NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPPREQUEUEDROPPED, |
1535 | skb_queue_len(&tp->ucopy.prequeue)); | |
b2fb4f54 | 1536 | |
0cef6a4c | 1537 | while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) |
b2fb4f54 | 1538 | sk_backlog_rcv(sk, skb1); |
b2fb4f54 ED |
1539 | |
1540 | tp->ucopy.memory = 0; | |
1541 | } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) { | |
1542 | wake_up_interruptible_sync_poll(sk_sleep(sk), | |
1543 | POLLIN | POLLRDNORM | POLLRDBAND); | |
1544 | if (!inet_csk_ack_scheduled(sk)) | |
1545 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, | |
1546 | (3 * tcp_rto_min(sk)) / 4, | |
1547 | TCP_RTO_MAX); | |
1548 | } | |
1549 | return true; | |
1550 | } | |
1551 | EXPORT_SYMBOL(tcp_prequeue); | |
1552 | ||
c9c33212 ED |
1553 | bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb) |
1554 | { | |
1555 | u32 limit = sk->sk_rcvbuf + sk->sk_sndbuf; | |
1556 | ||
1557 | /* Only socket owner can try to collapse/prune rx queues | |
1558 | * to reduce memory overhead, so add a little headroom here. | |
1559 | * Few sockets backlog are possibly concurrently non empty. | |
1560 | */ | |
1561 | limit += 64*1024; | |
1562 | ||
1563 | /* In case all data was pulled from skb frags (in __pskb_pull_tail()), | |
1564 | * we can fix skb->truesize to its real value to avoid future drops. | |
1565 | * This is valid because skb is not yet charged to the socket. | |
1566 | * It has been noticed pure SACK packets were sometimes dropped | |
1567 | * (if cooked by drivers without copybreak feature). | |
1568 | */ | |
60b1af33 | 1569 | skb_condense(skb); |
c9c33212 ED |
1570 | |
1571 | if (unlikely(sk_add_backlog(sk, skb, limit))) { | |
1572 | bh_unlock_sock(sk); | |
1573 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPBACKLOGDROP); | |
1574 | return true; | |
1575 | } | |
1576 | return false; | |
1577 | } | |
1578 | EXPORT_SYMBOL(tcp_add_backlog); | |
1579 | ||
ac6e7800 ED |
1580 | int tcp_filter(struct sock *sk, struct sk_buff *skb) |
1581 | { | |
1582 | struct tcphdr *th = (struct tcphdr *)skb->data; | |
1583 | unsigned int eaten = skb->len; | |
1584 | int err; | |
1585 | ||
1586 | err = sk_filter_trim_cap(sk, skb, th->doff * 4); | |
1587 | if (!err) { | |
1588 | eaten -= skb->len; | |
1589 | TCP_SKB_CB(skb)->end_seq -= eaten; | |
1590 | } | |
1591 | return err; | |
1592 | } | |
1593 | EXPORT_SYMBOL(tcp_filter); | |
1594 | ||
1da177e4 LT |
1595 | /* |
1596 | * From tcp_input.c | |
1597 | */ | |
1598 | ||
1599 | int tcp_v4_rcv(struct sk_buff *skb) | |
1600 | { | |
3b24d854 | 1601 | struct net *net = dev_net(skb->dev); |
eddc9ec5 | 1602 | const struct iphdr *iph; |
cf533ea5 | 1603 | const struct tcphdr *th; |
3b24d854 | 1604 | bool refcounted; |
1da177e4 LT |
1605 | struct sock *sk; |
1606 | int ret; | |
1607 | ||
1608 | if (skb->pkt_type != PACKET_HOST) | |
1609 | goto discard_it; | |
1610 | ||
1611 | /* Count it even if it's bad */ | |
90bbcc60 | 1612 | __TCP_INC_STATS(net, TCP_MIB_INSEGS); |
1da177e4 LT |
1613 | |
1614 | if (!pskb_may_pull(skb, sizeof(struct tcphdr))) | |
1615 | goto discard_it; | |
1616 | ||
ea1627c2 | 1617 | th = (const struct tcphdr *)skb->data; |
1da177e4 | 1618 | |
ea1627c2 | 1619 | if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) |
1da177e4 LT |
1620 | goto bad_packet; |
1621 | if (!pskb_may_pull(skb, th->doff * 4)) | |
1622 | goto discard_it; | |
1623 | ||
1624 | /* An explanation is required here, I think. | |
1625 | * Packet length and doff are validated by header prediction, | |
caa20d9a | 1626 | * provided case of th->doff==0 is eliminated. |
1da177e4 | 1627 | * So, we defer the checks. */ |
ed70fcfc TH |
1628 | |
1629 | if (skb_checksum_init(skb, IPPROTO_TCP, inet_compute_pseudo)) | |
6a5dc9e5 | 1630 | goto csum_error; |
1da177e4 | 1631 | |
ea1627c2 | 1632 | th = (const struct tcphdr *)skb->data; |
eddc9ec5 | 1633 | iph = ip_hdr(skb); |
971f10ec ED |
1634 | /* This is tricky : We move IPCB at its correct location into TCP_SKB_CB() |
1635 | * barrier() makes sure compiler wont play fool^Waliasing games. | |
1636 | */ | |
1637 | memmove(&TCP_SKB_CB(skb)->header.h4, IPCB(skb), | |
1638 | sizeof(struct inet_skb_parm)); | |
1639 | barrier(); | |
1640 | ||
1da177e4 LT |
1641 | TCP_SKB_CB(skb)->seq = ntohl(th->seq); |
1642 | TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + | |
1643 | skb->len - th->doff * 4); | |
1644 | TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); | |
e11ecddf | 1645 | TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th); |
04317daf | 1646 | TCP_SKB_CB(skb)->tcp_tw_isn = 0; |
b82d1bb4 | 1647 | TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph); |
1da177e4 LT |
1648 | TCP_SKB_CB(skb)->sacked = 0; |
1649 | ||
4bdc3d66 | 1650 | lookup: |
a583636a | 1651 | sk = __inet_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th), th->source, |
3b24d854 | 1652 | th->dest, &refcounted); |
1da177e4 LT |
1653 | if (!sk) |
1654 | goto no_tcp_socket; | |
1655 | ||
bb134d5d ED |
1656 | process: |
1657 | if (sk->sk_state == TCP_TIME_WAIT) | |
1658 | goto do_time_wait; | |
1659 | ||
079096f1 ED |
1660 | if (sk->sk_state == TCP_NEW_SYN_RECV) { |
1661 | struct request_sock *req = inet_reqsk(sk); | |
7716682c | 1662 | struct sock *nsk; |
079096f1 ED |
1663 | |
1664 | sk = req->rsk_listener; | |
72923555 | 1665 | if (unlikely(tcp_v4_inbound_md5_hash(sk, skb))) { |
e65c332d | 1666 | sk_drops_add(sk, skb); |
72923555 ED |
1667 | reqsk_put(req); |
1668 | goto discard_it; | |
1669 | } | |
7716682c | 1670 | if (unlikely(sk->sk_state != TCP_LISTEN)) { |
f03f2e15 | 1671 | inet_csk_reqsk_queue_drop_and_put(sk, req); |
4bdc3d66 ED |
1672 | goto lookup; |
1673 | } | |
3b24d854 ED |
1674 | /* We own a reference on the listener, increase it again |
1675 | * as we might lose it too soon. | |
1676 | */ | |
7716682c | 1677 | sock_hold(sk); |
3b24d854 | 1678 | refcounted = true; |
7716682c | 1679 | nsk = tcp_check_req(sk, skb, req, false); |
079096f1 ED |
1680 | if (!nsk) { |
1681 | reqsk_put(req); | |
7716682c | 1682 | goto discard_and_relse; |
079096f1 ED |
1683 | } |
1684 | if (nsk == sk) { | |
079096f1 ED |
1685 | reqsk_put(req); |
1686 | } else if (tcp_child_process(sk, nsk, skb)) { | |
1687 | tcp_v4_send_reset(nsk, skb); | |
7716682c | 1688 | goto discard_and_relse; |
079096f1 | 1689 | } else { |
7716682c | 1690 | sock_put(sk); |
079096f1 ED |
1691 | return 0; |
1692 | } | |
1693 | } | |
6cce09f8 | 1694 | if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { |
02a1d6e7 | 1695 | __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); |
d218d111 | 1696 | goto discard_and_relse; |
6cce09f8 | 1697 | } |
d218d111 | 1698 | |
1da177e4 LT |
1699 | if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) |
1700 | goto discard_and_relse; | |
9ea88a15 | 1701 | |
9ea88a15 DP |
1702 | if (tcp_v4_inbound_md5_hash(sk, skb)) |
1703 | goto discard_and_relse; | |
9ea88a15 | 1704 | |
b59c2701 | 1705 | nf_reset(skb); |
1da177e4 | 1706 | |
ac6e7800 | 1707 | if (tcp_filter(sk, skb)) |
1da177e4 | 1708 | goto discard_and_relse; |
ac6e7800 ED |
1709 | th = (const struct tcphdr *)skb->data; |
1710 | iph = ip_hdr(skb); | |
1da177e4 LT |
1711 | |
1712 | skb->dev = NULL; | |
1713 | ||
e994b2f0 ED |
1714 | if (sk->sk_state == TCP_LISTEN) { |
1715 | ret = tcp_v4_do_rcv(sk, skb); | |
1716 | goto put_and_return; | |
1717 | } | |
1718 | ||
1719 | sk_incoming_cpu_update(sk); | |
1720 | ||
c6366184 | 1721 | bh_lock_sock_nested(sk); |
a44d6eac | 1722 | tcp_segs_in(tcp_sk(sk), skb); |
1da177e4 LT |
1723 | ret = 0; |
1724 | if (!sock_owned_by_user(sk)) { | |
7bced397 | 1725 | if (!tcp_prequeue(sk, skb)) |
1da177e4 | 1726 | ret = tcp_v4_do_rcv(sk, skb); |
c9c33212 | 1727 | } else if (tcp_add_backlog(sk, skb)) { |
6b03a53a ZY |
1728 | goto discard_and_relse; |
1729 | } | |
1da177e4 LT |
1730 | bh_unlock_sock(sk); |
1731 | ||
e994b2f0 | 1732 | put_and_return: |
3b24d854 ED |
1733 | if (refcounted) |
1734 | sock_put(sk); | |
1da177e4 LT |
1735 | |
1736 | return ret; | |
1737 | ||
1738 | no_tcp_socket: | |
1739 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) | |
1740 | goto discard_it; | |
1741 | ||
12e25e10 | 1742 | if (tcp_checksum_complete(skb)) { |
6a5dc9e5 | 1743 | csum_error: |
90bbcc60 | 1744 | __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); |
1da177e4 | 1745 | bad_packet: |
90bbcc60 | 1746 | __TCP_INC_STATS(net, TCP_MIB_INERRS); |
1da177e4 | 1747 | } else { |
cfb6eeb4 | 1748 | tcp_v4_send_reset(NULL, skb); |
1da177e4 LT |
1749 | } |
1750 | ||
1751 | discard_it: | |
1752 | /* Discard frame. */ | |
1753 | kfree_skb(skb); | |
e905a9ed | 1754 | return 0; |
1da177e4 LT |
1755 | |
1756 | discard_and_relse: | |
532182cd | 1757 | sk_drops_add(sk, skb); |
3b24d854 ED |
1758 | if (refcounted) |
1759 | sock_put(sk); | |
1da177e4 LT |
1760 | goto discard_it; |
1761 | ||
1762 | do_time_wait: | |
1763 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { | |
9469c7b4 | 1764 | inet_twsk_put(inet_twsk(sk)); |
1da177e4 LT |
1765 | goto discard_it; |
1766 | } | |
1767 | ||
6a5dc9e5 ED |
1768 | if (tcp_checksum_complete(skb)) { |
1769 | inet_twsk_put(inet_twsk(sk)); | |
1770 | goto csum_error; | |
1da177e4 | 1771 | } |
9469c7b4 | 1772 | switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { |
1da177e4 | 1773 | case TCP_TW_SYN: { |
c346dca1 | 1774 | struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev), |
a583636a CG |
1775 | &tcp_hashinfo, skb, |
1776 | __tcp_hdrlen(th), | |
da5e3630 | 1777 | iph->saddr, th->source, |
eddc9ec5 | 1778 | iph->daddr, th->dest, |
463c84b9 | 1779 | inet_iif(skb)); |
1da177e4 | 1780 | if (sk2) { |
dbe7faa4 | 1781 | inet_twsk_deschedule_put(inet_twsk(sk)); |
1da177e4 | 1782 | sk = sk2; |
3b24d854 | 1783 | refcounted = false; |
1da177e4 LT |
1784 | goto process; |
1785 | } | |
1786 | /* Fall through to ACK */ | |
1787 | } | |
1788 | case TCP_TW_ACK: | |
1789 | tcp_v4_timewait_ack(sk, skb); | |
1790 | break; | |
1791 | case TCP_TW_RST: | |
271c3b9b FW |
1792 | tcp_v4_send_reset(sk, skb); |
1793 | inet_twsk_deschedule_put(inet_twsk(sk)); | |
1794 | goto discard_it; | |
1da177e4 LT |
1795 | case TCP_TW_SUCCESS:; |
1796 | } | |
1797 | goto discard_it; | |
1798 | } | |
1799 | ||
ccb7c410 DM |
1800 | static struct timewait_sock_ops tcp_timewait_sock_ops = { |
1801 | .twsk_obj_size = sizeof(struct tcp_timewait_sock), | |
1802 | .twsk_unique = tcp_twsk_unique, | |
1803 | .twsk_destructor= tcp_twsk_destructor, | |
ccb7c410 | 1804 | }; |
1da177e4 | 1805 | |
63d02d15 | 1806 | void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb) |
5d299f3d ED |
1807 | { |
1808 | struct dst_entry *dst = skb_dst(skb); | |
1809 | ||
5037e9ef | 1810 | if (dst && dst_hold_safe(dst)) { |
ca777eff ED |
1811 | sk->sk_rx_dst = dst; |
1812 | inet_sk(sk)->rx_dst_ifindex = skb->skb_iif; | |
1813 | } | |
5d299f3d | 1814 | } |
63d02d15 | 1815 | EXPORT_SYMBOL(inet_sk_rx_dst_set); |
5d299f3d | 1816 | |
3b401a81 | 1817 | const struct inet_connection_sock_af_ops ipv4_specific = { |
543d9cfe ACM |
1818 | .queue_xmit = ip_queue_xmit, |
1819 | .send_check = tcp_v4_send_check, | |
1820 | .rebuild_header = inet_sk_rebuild_header, | |
5d299f3d | 1821 | .sk_rx_dst_set = inet_sk_rx_dst_set, |
543d9cfe ACM |
1822 | .conn_request = tcp_v4_conn_request, |
1823 | .syn_recv_sock = tcp_v4_syn_recv_sock, | |
543d9cfe ACM |
1824 | .net_header_len = sizeof(struct iphdr), |
1825 | .setsockopt = ip_setsockopt, | |
1826 | .getsockopt = ip_getsockopt, | |
1827 | .addr2sockaddr = inet_csk_addr2sockaddr, | |
1828 | .sockaddr_len = sizeof(struct sockaddr_in), | |
3fdadf7d | 1829 | #ifdef CONFIG_COMPAT |
543d9cfe ACM |
1830 | .compat_setsockopt = compat_ip_setsockopt, |
1831 | .compat_getsockopt = compat_ip_getsockopt, | |
3fdadf7d | 1832 | #endif |
4fab9071 | 1833 | .mtu_reduced = tcp_v4_mtu_reduced, |
1da177e4 | 1834 | }; |
4bc2f18b | 1835 | EXPORT_SYMBOL(ipv4_specific); |
1da177e4 | 1836 | |
cfb6eeb4 | 1837 | #ifdef CONFIG_TCP_MD5SIG |
b2e4b3de | 1838 | static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = { |
cfb6eeb4 | 1839 | .md5_lookup = tcp_v4_md5_lookup, |
49a72dfb | 1840 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
cfb6eeb4 | 1841 | .md5_parse = tcp_v4_parse_md5_keys, |
cfb6eeb4 | 1842 | }; |
b6332e6c | 1843 | #endif |
cfb6eeb4 | 1844 | |
1da177e4 LT |
1845 | /* NOTE: A lot of things set to zero explicitly by call to |
1846 | * sk_alloc() so need not be done here. | |
1847 | */ | |
1848 | static int tcp_v4_init_sock(struct sock *sk) | |
1849 | { | |
6687e988 | 1850 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 | 1851 | |
900f65d3 | 1852 | tcp_init_sock(sk); |
1da177e4 | 1853 | |
8292a17a | 1854 | icsk->icsk_af_ops = &ipv4_specific; |
900f65d3 | 1855 | |
cfb6eeb4 | 1856 | #ifdef CONFIG_TCP_MD5SIG |
ac807fa8 | 1857 | tcp_sk(sk)->af_specific = &tcp_sock_ipv4_specific; |
cfb6eeb4 | 1858 | #endif |
1da177e4 | 1859 | |
1da177e4 LT |
1860 | return 0; |
1861 | } | |
1862 | ||
7d06b2e0 | 1863 | void tcp_v4_destroy_sock(struct sock *sk) |
1da177e4 LT |
1864 | { |
1865 | struct tcp_sock *tp = tcp_sk(sk); | |
1866 | ||
1867 | tcp_clear_xmit_timers(sk); | |
1868 | ||
6687e988 | 1869 | tcp_cleanup_congestion_control(sk); |
317a76f9 | 1870 | |
1da177e4 | 1871 | /* Cleanup up the write buffer. */ |
fe067e8a | 1872 | tcp_write_queue_purge(sk); |
1da177e4 LT |
1873 | |
1874 | /* Cleans up our, hopefully empty, out_of_order_queue. */ | |
9f5afeae | 1875 | skb_rbtree_purge(&tp->out_of_order_queue); |
1da177e4 | 1876 | |
cfb6eeb4 YH |
1877 | #ifdef CONFIG_TCP_MD5SIG |
1878 | /* Clean up the MD5 key list, if any */ | |
1879 | if (tp->md5sig_info) { | |
a915da9b | 1880 | tcp_clear_md5_list(sk); |
a8afca03 | 1881 | kfree_rcu(tp->md5sig_info, rcu); |
cfb6eeb4 YH |
1882 | tp->md5sig_info = NULL; |
1883 | } | |
1884 | #endif | |
1a2449a8 | 1885 | |
1da177e4 LT |
1886 | /* Clean prequeue, it must be empty really */ |
1887 | __skb_queue_purge(&tp->ucopy.prequeue); | |
1888 | ||
1889 | /* Clean up a referenced TCP bind bucket. */ | |
463c84b9 | 1890 | if (inet_csk(sk)->icsk_bind_hash) |
ab1e0a13 | 1891 | inet_put_port(sk); |
1da177e4 | 1892 | |
00db4124 | 1893 | BUG_ON(tp->fastopen_rsk); |
435cf559 | 1894 | |
cf60af03 YC |
1895 | /* If socket is aborted during connect operation */ |
1896 | tcp_free_fastopen_req(tp); | |
cd8ae852 | 1897 | tcp_saved_syn_free(tp); |
cf60af03 | 1898 | |
180d8cd9 | 1899 | sk_sockets_allocated_dec(sk); |
1da177e4 | 1900 | } |
1da177e4 LT |
1901 | EXPORT_SYMBOL(tcp_v4_destroy_sock); |
1902 | ||
1903 | #ifdef CONFIG_PROC_FS | |
1904 | /* Proc filesystem TCP sock list dumping. */ | |
1905 | ||
a8b690f9 TH |
1906 | /* |
1907 | * Get next listener socket follow cur. If cur is NULL, get first socket | |
1908 | * starting from bucket given in st->bucket; when st->bucket is zero the | |
1909 | * very first socket in the hash table is returned. | |
1910 | */ | |
1da177e4 LT |
1911 | static void *listening_get_next(struct seq_file *seq, void *cur) |
1912 | { | |
5799de0b | 1913 | struct tcp_iter_state *st = seq->private; |
a4146b1b | 1914 | struct net *net = seq_file_net(seq); |
3b24d854 | 1915 | struct inet_listen_hashbucket *ilb; |
3b24d854 | 1916 | struct sock *sk = cur; |
1da177e4 LT |
1917 | |
1918 | if (!sk) { | |
3b24d854 | 1919 | get_head: |
a8b690f9 | 1920 | ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
9652dc2e | 1921 | spin_lock(&ilb->lock); |
3b24d854 | 1922 | sk = sk_head(&ilb->head); |
a8b690f9 | 1923 | st->offset = 0; |
1da177e4 LT |
1924 | goto get_sk; |
1925 | } | |
5caea4ea | 1926 | ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
1da177e4 | 1927 | ++st->num; |
a8b690f9 | 1928 | ++st->offset; |
1da177e4 | 1929 | |
3b24d854 | 1930 | sk = sk_next(sk); |
1da177e4 | 1931 | get_sk: |
3b24d854 | 1932 | sk_for_each_from(sk) { |
8475ef9f PE |
1933 | if (!net_eq(sock_net(sk), net)) |
1934 | continue; | |
3b24d854 ED |
1935 | if (sk->sk_family == st->family) |
1936 | return sk; | |
1da177e4 | 1937 | } |
9652dc2e | 1938 | spin_unlock(&ilb->lock); |
a8b690f9 | 1939 | st->offset = 0; |
3b24d854 ED |
1940 | if (++st->bucket < INET_LHTABLE_SIZE) |
1941 | goto get_head; | |
1942 | return NULL; | |
1da177e4 LT |
1943 | } |
1944 | ||
1945 | static void *listening_get_idx(struct seq_file *seq, loff_t *pos) | |
1946 | { | |
a8b690f9 TH |
1947 | struct tcp_iter_state *st = seq->private; |
1948 | void *rc; | |
1949 | ||
1950 | st->bucket = 0; | |
1951 | st->offset = 0; | |
1952 | rc = listening_get_next(seq, NULL); | |
1da177e4 LT |
1953 | |
1954 | while (rc && *pos) { | |
1955 | rc = listening_get_next(seq, rc); | |
1956 | --*pos; | |
1957 | } | |
1958 | return rc; | |
1959 | } | |
1960 | ||
05dbc7b5 | 1961 | static inline bool empty_bucket(const struct tcp_iter_state *st) |
6eac5604 | 1962 | { |
05dbc7b5 | 1963 | return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain); |
6eac5604 AK |
1964 | } |
1965 | ||
a8b690f9 TH |
1966 | /* |
1967 | * Get first established socket starting from bucket given in st->bucket. | |
1968 | * If st->bucket is zero, the very first socket in the hash is returned. | |
1969 | */ | |
1da177e4 LT |
1970 | static void *established_get_first(struct seq_file *seq) |
1971 | { | |
5799de0b | 1972 | struct tcp_iter_state *st = seq->private; |
a4146b1b | 1973 | struct net *net = seq_file_net(seq); |
1da177e4 LT |
1974 | void *rc = NULL; |
1975 | ||
a8b690f9 TH |
1976 | st->offset = 0; |
1977 | for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) { | |
1da177e4 | 1978 | struct sock *sk; |
3ab5aee7 | 1979 | struct hlist_nulls_node *node; |
9db66bdc | 1980 | spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket); |
1da177e4 | 1981 | |
6eac5604 AK |
1982 | /* Lockless fast path for the common case of empty buckets */ |
1983 | if (empty_bucket(st)) | |
1984 | continue; | |
1985 | ||
9db66bdc | 1986 | spin_lock_bh(lock); |
3ab5aee7 | 1987 | sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) { |
f40c8174 | 1988 | if (sk->sk_family != st->family || |
878628fb | 1989 | !net_eq(sock_net(sk), net)) { |
1da177e4 LT |
1990 | continue; |
1991 | } | |
1992 | rc = sk; | |
1993 | goto out; | |
1994 | } | |
9db66bdc | 1995 | spin_unlock_bh(lock); |
1da177e4 LT |
1996 | } |
1997 | out: | |
1998 | return rc; | |
1999 | } | |
2000 | ||
2001 | static void *established_get_next(struct seq_file *seq, void *cur) | |
2002 | { | |
2003 | struct sock *sk = cur; | |
3ab5aee7 | 2004 | struct hlist_nulls_node *node; |
5799de0b | 2005 | struct tcp_iter_state *st = seq->private; |
a4146b1b | 2006 | struct net *net = seq_file_net(seq); |
1da177e4 LT |
2007 | |
2008 | ++st->num; | |
a8b690f9 | 2009 | ++st->offset; |
1da177e4 | 2010 | |
05dbc7b5 | 2011 | sk = sk_nulls_next(sk); |
1da177e4 | 2012 | |
3ab5aee7 | 2013 | sk_nulls_for_each_from(sk, node) { |
878628fb | 2014 | if (sk->sk_family == st->family && net_eq(sock_net(sk), net)) |
05dbc7b5 | 2015 | return sk; |
1da177e4 LT |
2016 | } |
2017 | ||
05dbc7b5 ED |
2018 | spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); |
2019 | ++st->bucket; | |
2020 | return established_get_first(seq); | |
1da177e4 LT |
2021 | } |
2022 | ||
2023 | static void *established_get_idx(struct seq_file *seq, loff_t pos) | |
2024 | { | |
a8b690f9 TH |
2025 | struct tcp_iter_state *st = seq->private; |
2026 | void *rc; | |
2027 | ||
2028 | st->bucket = 0; | |
2029 | rc = established_get_first(seq); | |
1da177e4 LT |
2030 | |
2031 | while (rc && pos) { | |
2032 | rc = established_get_next(seq, rc); | |
2033 | --pos; | |
7174259e | 2034 | } |
1da177e4 LT |
2035 | return rc; |
2036 | } | |
2037 | ||
2038 | static void *tcp_get_idx(struct seq_file *seq, loff_t pos) | |
2039 | { | |
2040 | void *rc; | |
5799de0b | 2041 | struct tcp_iter_state *st = seq->private; |
1da177e4 | 2042 | |
1da177e4 LT |
2043 | st->state = TCP_SEQ_STATE_LISTENING; |
2044 | rc = listening_get_idx(seq, &pos); | |
2045 | ||
2046 | if (!rc) { | |
1da177e4 LT |
2047 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2048 | rc = established_get_idx(seq, pos); | |
2049 | } | |
2050 | ||
2051 | return rc; | |
2052 | } | |
2053 | ||
a8b690f9 TH |
2054 | static void *tcp_seek_last_pos(struct seq_file *seq) |
2055 | { | |
2056 | struct tcp_iter_state *st = seq->private; | |
2057 | int offset = st->offset; | |
2058 | int orig_num = st->num; | |
2059 | void *rc = NULL; | |
2060 | ||
2061 | switch (st->state) { | |
a8b690f9 TH |
2062 | case TCP_SEQ_STATE_LISTENING: |
2063 | if (st->bucket >= INET_LHTABLE_SIZE) | |
2064 | break; | |
2065 | st->state = TCP_SEQ_STATE_LISTENING; | |
2066 | rc = listening_get_next(seq, NULL); | |
2067 | while (offset-- && rc) | |
2068 | rc = listening_get_next(seq, rc); | |
2069 | if (rc) | |
2070 | break; | |
2071 | st->bucket = 0; | |
05dbc7b5 | 2072 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
a8b690f9 TH |
2073 | /* Fallthrough */ |
2074 | case TCP_SEQ_STATE_ESTABLISHED: | |
a8b690f9 TH |
2075 | if (st->bucket > tcp_hashinfo.ehash_mask) |
2076 | break; | |
2077 | rc = established_get_first(seq); | |
2078 | while (offset-- && rc) | |
2079 | rc = established_get_next(seq, rc); | |
2080 | } | |
2081 | ||
2082 | st->num = orig_num; | |
2083 | ||
2084 | return rc; | |
2085 | } | |
2086 | ||
1da177e4 LT |
2087 | static void *tcp_seq_start(struct seq_file *seq, loff_t *pos) |
2088 | { | |
5799de0b | 2089 | struct tcp_iter_state *st = seq->private; |
a8b690f9 TH |
2090 | void *rc; |
2091 | ||
2092 | if (*pos && *pos == st->last_pos) { | |
2093 | rc = tcp_seek_last_pos(seq); | |
2094 | if (rc) | |
2095 | goto out; | |
2096 | } | |
2097 | ||
1da177e4 LT |
2098 | st->state = TCP_SEQ_STATE_LISTENING; |
2099 | st->num = 0; | |
a8b690f9 TH |
2100 | st->bucket = 0; |
2101 | st->offset = 0; | |
2102 | rc = *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
2103 | ||
2104 | out: | |
2105 | st->last_pos = *pos; | |
2106 | return rc; | |
1da177e4 LT |
2107 | } |
2108 | ||
2109 | static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2110 | { | |
a8b690f9 | 2111 | struct tcp_iter_state *st = seq->private; |
1da177e4 | 2112 | void *rc = NULL; |
1da177e4 LT |
2113 | |
2114 | if (v == SEQ_START_TOKEN) { | |
2115 | rc = tcp_get_idx(seq, 0); | |
2116 | goto out; | |
2117 | } | |
1da177e4 LT |
2118 | |
2119 | switch (st->state) { | |
1da177e4 LT |
2120 | case TCP_SEQ_STATE_LISTENING: |
2121 | rc = listening_get_next(seq, v); | |
2122 | if (!rc) { | |
1da177e4 | 2123 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
a8b690f9 TH |
2124 | st->bucket = 0; |
2125 | st->offset = 0; | |
1da177e4 LT |
2126 | rc = established_get_first(seq); |
2127 | } | |
2128 | break; | |
2129 | case TCP_SEQ_STATE_ESTABLISHED: | |
1da177e4 LT |
2130 | rc = established_get_next(seq, v); |
2131 | break; | |
2132 | } | |
2133 | out: | |
2134 | ++*pos; | |
a8b690f9 | 2135 | st->last_pos = *pos; |
1da177e4 LT |
2136 | return rc; |
2137 | } | |
2138 | ||
2139 | static void tcp_seq_stop(struct seq_file *seq, void *v) | |
2140 | { | |
5799de0b | 2141 | struct tcp_iter_state *st = seq->private; |
1da177e4 LT |
2142 | |
2143 | switch (st->state) { | |
1da177e4 LT |
2144 | case TCP_SEQ_STATE_LISTENING: |
2145 | if (v != SEQ_START_TOKEN) | |
9652dc2e | 2146 | spin_unlock(&tcp_hashinfo.listening_hash[st->bucket].lock); |
1da177e4 | 2147 | break; |
1da177e4 LT |
2148 | case TCP_SEQ_STATE_ESTABLISHED: |
2149 | if (v) | |
9db66bdc | 2150 | spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); |
1da177e4 LT |
2151 | break; |
2152 | } | |
2153 | } | |
2154 | ||
73cb88ec | 2155 | int tcp_seq_open(struct inode *inode, struct file *file) |
1da177e4 | 2156 | { |
d9dda78b | 2157 | struct tcp_seq_afinfo *afinfo = PDE_DATA(inode); |
1da177e4 | 2158 | struct tcp_iter_state *s; |
52d6f3f1 | 2159 | int err; |
1da177e4 | 2160 | |
52d6f3f1 DL |
2161 | err = seq_open_net(inode, file, &afinfo->seq_ops, |
2162 | sizeof(struct tcp_iter_state)); | |
2163 | if (err < 0) | |
2164 | return err; | |
f40c8174 | 2165 | |
52d6f3f1 | 2166 | s = ((struct seq_file *)file->private_data)->private; |
1da177e4 | 2167 | s->family = afinfo->family; |
688d1945 | 2168 | s->last_pos = 0; |
f40c8174 DL |
2169 | return 0; |
2170 | } | |
73cb88ec | 2171 | EXPORT_SYMBOL(tcp_seq_open); |
f40c8174 | 2172 | |
6f8b13bc | 2173 | int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo) |
1da177e4 LT |
2174 | { |
2175 | int rc = 0; | |
2176 | struct proc_dir_entry *p; | |
2177 | ||
9427c4b3 DL |
2178 | afinfo->seq_ops.start = tcp_seq_start; |
2179 | afinfo->seq_ops.next = tcp_seq_next; | |
2180 | afinfo->seq_ops.stop = tcp_seq_stop; | |
2181 | ||
84841c3c | 2182 | p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, |
73cb88ec | 2183 | afinfo->seq_fops, afinfo); |
84841c3c | 2184 | if (!p) |
1da177e4 LT |
2185 | rc = -ENOMEM; |
2186 | return rc; | |
2187 | } | |
4bc2f18b | 2188 | EXPORT_SYMBOL(tcp_proc_register); |
1da177e4 | 2189 | |
6f8b13bc | 2190 | void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo) |
1da177e4 | 2191 | { |
ece31ffd | 2192 | remove_proc_entry(afinfo->name, net->proc_net); |
1da177e4 | 2193 | } |
4bc2f18b | 2194 | EXPORT_SYMBOL(tcp_proc_unregister); |
1da177e4 | 2195 | |
d4f06873 | 2196 | static void get_openreq4(const struct request_sock *req, |
aa3a0c8c | 2197 | struct seq_file *f, int i) |
1da177e4 | 2198 | { |
2e6599cb | 2199 | const struct inet_request_sock *ireq = inet_rsk(req); |
fa76ce73 | 2200 | long delta = req->rsk_timer.expires - jiffies; |
1da177e4 | 2201 | |
5e659e4c | 2202 | seq_printf(f, "%4d: %08X:%04X %08X:%04X" |
652586df | 2203 | " %02X %08X:%08X %02X:%08lX %08X %5u %8d %u %d %pK", |
1da177e4 | 2204 | i, |
634fb979 | 2205 | ireq->ir_loc_addr, |
d4f06873 | 2206 | ireq->ir_num, |
634fb979 ED |
2207 | ireq->ir_rmt_addr, |
2208 | ntohs(ireq->ir_rmt_port), | |
1da177e4 LT |
2209 | TCP_SYN_RECV, |
2210 | 0, 0, /* could print option size, but that is af dependent. */ | |
2211 | 1, /* timers active (only the expire timer) */ | |
a399a805 | 2212 | jiffies_delta_to_clock_t(delta), |
e6c022a4 | 2213 | req->num_timeout, |
aa3a0c8c ED |
2214 | from_kuid_munged(seq_user_ns(f), |
2215 | sock_i_uid(req->rsk_listener)), | |
1da177e4 LT |
2216 | 0, /* non standard timer */ |
2217 | 0, /* open_requests have no inode */ | |
d4f06873 | 2218 | 0, |
652586df | 2219 | req); |
1da177e4 LT |
2220 | } |
2221 | ||
652586df | 2222 | static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i) |
1da177e4 LT |
2223 | { |
2224 | int timer_active; | |
2225 | unsigned long timer_expires; | |
cf533ea5 | 2226 | const struct tcp_sock *tp = tcp_sk(sk); |
cf4c6bf8 | 2227 | const struct inet_connection_sock *icsk = inet_csk(sk); |
cf533ea5 | 2228 | const struct inet_sock *inet = inet_sk(sk); |
0536fcc0 | 2229 | const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq; |
c720c7e8 ED |
2230 | __be32 dest = inet->inet_daddr; |
2231 | __be32 src = inet->inet_rcv_saddr; | |
2232 | __u16 destp = ntohs(inet->inet_dport); | |
2233 | __u16 srcp = ntohs(inet->inet_sport); | |
49d09007 | 2234 | int rx_queue; |
00fd38d9 | 2235 | int state; |
1da177e4 | 2236 | |
6ba8a3b1 | 2237 | if (icsk->icsk_pending == ICSK_TIME_RETRANS || |
57dde7f7 | 2238 | icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || |
6ba8a3b1 | 2239 | icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { |
1da177e4 | 2240 | timer_active = 1; |
463c84b9 ACM |
2241 | timer_expires = icsk->icsk_timeout; |
2242 | } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { | |
1da177e4 | 2243 | timer_active = 4; |
463c84b9 | 2244 | timer_expires = icsk->icsk_timeout; |
cf4c6bf8 | 2245 | } else if (timer_pending(&sk->sk_timer)) { |
1da177e4 | 2246 | timer_active = 2; |
cf4c6bf8 | 2247 | timer_expires = sk->sk_timer.expires; |
1da177e4 LT |
2248 | } else { |
2249 | timer_active = 0; | |
2250 | timer_expires = jiffies; | |
2251 | } | |
2252 | ||
00fd38d9 ED |
2253 | state = sk_state_load(sk); |
2254 | if (state == TCP_LISTEN) | |
49d09007 ED |
2255 | rx_queue = sk->sk_ack_backlog; |
2256 | else | |
00fd38d9 ED |
2257 | /* Because we don't lock the socket, |
2258 | * we might find a transient negative value. | |
49d09007 ED |
2259 | */ |
2260 | rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0); | |
2261 | ||
5e659e4c | 2262 | seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX " |
652586df | 2263 | "%08X %5u %8d %lu %d %pK %lu %lu %u %u %d", |
00fd38d9 | 2264 | i, src, srcp, dest, destp, state, |
47da8ee6 | 2265 | tp->write_seq - tp->snd_una, |
49d09007 | 2266 | rx_queue, |
1da177e4 | 2267 | timer_active, |
a399a805 | 2268 | jiffies_delta_to_clock_t(timer_expires - jiffies), |
463c84b9 | 2269 | icsk->icsk_retransmits, |
a7cb5a49 | 2270 | from_kuid_munged(seq_user_ns(f), sock_i_uid(sk)), |
6687e988 | 2271 | icsk->icsk_probes_out, |
cf4c6bf8 IJ |
2272 | sock_i_ino(sk), |
2273 | atomic_read(&sk->sk_refcnt), sk, | |
7be87351 SH |
2274 | jiffies_to_clock_t(icsk->icsk_rto), |
2275 | jiffies_to_clock_t(icsk->icsk_ack.ato), | |
463c84b9 | 2276 | (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong, |
1da177e4 | 2277 | tp->snd_cwnd, |
00fd38d9 ED |
2278 | state == TCP_LISTEN ? |
2279 | fastopenq->max_qlen : | |
652586df | 2280 | (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)); |
1da177e4 LT |
2281 | } |
2282 | ||
cf533ea5 | 2283 | static void get_timewait4_sock(const struct inet_timewait_sock *tw, |
652586df | 2284 | struct seq_file *f, int i) |
1da177e4 | 2285 | { |
789f558c | 2286 | long delta = tw->tw_timer.expires - jiffies; |
23f33c2d | 2287 | __be32 dest, src; |
1da177e4 | 2288 | __u16 destp, srcp; |
1da177e4 LT |
2289 | |
2290 | dest = tw->tw_daddr; | |
2291 | src = tw->tw_rcv_saddr; | |
2292 | destp = ntohs(tw->tw_dport); | |
2293 | srcp = ntohs(tw->tw_sport); | |
2294 | ||
5e659e4c | 2295 | seq_printf(f, "%4d: %08X:%04X %08X:%04X" |
652586df | 2296 | " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK", |
1da177e4 | 2297 | i, src, srcp, dest, destp, tw->tw_substate, 0, 0, |
a399a805 | 2298 | 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0, |
652586df | 2299 | atomic_read(&tw->tw_refcnt), tw); |
1da177e4 LT |
2300 | } |
2301 | ||
2302 | #define TMPSZ 150 | |
2303 | ||
2304 | static int tcp4_seq_show(struct seq_file *seq, void *v) | |
2305 | { | |
5799de0b | 2306 | struct tcp_iter_state *st; |
05dbc7b5 | 2307 | struct sock *sk = v; |
1da177e4 | 2308 | |
652586df | 2309 | seq_setwidth(seq, TMPSZ - 1); |
1da177e4 | 2310 | if (v == SEQ_START_TOKEN) { |
652586df | 2311 | seq_puts(seq, " sl local_address rem_address st tx_queue " |
1da177e4 LT |
2312 | "rx_queue tr tm->when retrnsmt uid timeout " |
2313 | "inode"); | |
2314 | goto out; | |
2315 | } | |
2316 | st = seq->private; | |
2317 | ||
079096f1 ED |
2318 | if (sk->sk_state == TCP_TIME_WAIT) |
2319 | get_timewait4_sock(v, seq, st->num); | |
2320 | else if (sk->sk_state == TCP_NEW_SYN_RECV) | |
aa3a0c8c | 2321 | get_openreq4(v, seq, st->num); |
079096f1 ED |
2322 | else |
2323 | get_tcp4_sock(v, seq, st->num); | |
1da177e4 | 2324 | out: |
652586df | 2325 | seq_pad(seq, '\n'); |
1da177e4 LT |
2326 | return 0; |
2327 | } | |
2328 | ||
73cb88ec AV |
2329 | static const struct file_operations tcp_afinfo_seq_fops = { |
2330 | .owner = THIS_MODULE, | |
2331 | .open = tcp_seq_open, | |
2332 | .read = seq_read, | |
2333 | .llseek = seq_lseek, | |
2334 | .release = seq_release_net | |
2335 | }; | |
2336 | ||
1da177e4 | 2337 | static struct tcp_seq_afinfo tcp4_seq_afinfo = { |
1da177e4 LT |
2338 | .name = "tcp", |
2339 | .family = AF_INET, | |
73cb88ec | 2340 | .seq_fops = &tcp_afinfo_seq_fops, |
9427c4b3 DL |
2341 | .seq_ops = { |
2342 | .show = tcp4_seq_show, | |
2343 | }, | |
1da177e4 LT |
2344 | }; |
2345 | ||
2c8c1e72 | 2346 | static int __net_init tcp4_proc_init_net(struct net *net) |
757764f6 PE |
2347 | { |
2348 | return tcp_proc_register(net, &tcp4_seq_afinfo); | |
2349 | } | |
2350 | ||
2c8c1e72 | 2351 | static void __net_exit tcp4_proc_exit_net(struct net *net) |
757764f6 PE |
2352 | { |
2353 | tcp_proc_unregister(net, &tcp4_seq_afinfo); | |
2354 | } | |
2355 | ||
2356 | static struct pernet_operations tcp4_net_ops = { | |
2357 | .init = tcp4_proc_init_net, | |
2358 | .exit = tcp4_proc_exit_net, | |
2359 | }; | |
2360 | ||
1da177e4 LT |
2361 | int __init tcp4_proc_init(void) |
2362 | { | |
757764f6 | 2363 | return register_pernet_subsys(&tcp4_net_ops); |
1da177e4 LT |
2364 | } |
2365 | ||
2366 | void tcp4_proc_exit(void) | |
2367 | { | |
757764f6 | 2368 | unregister_pernet_subsys(&tcp4_net_ops); |
1da177e4 LT |
2369 | } |
2370 | #endif /* CONFIG_PROC_FS */ | |
2371 | ||
2372 | struct proto tcp_prot = { | |
2373 | .name = "TCP", | |
2374 | .owner = THIS_MODULE, | |
2375 | .close = tcp_close, | |
2376 | .connect = tcp_v4_connect, | |
2377 | .disconnect = tcp_disconnect, | |
463c84b9 | 2378 | .accept = inet_csk_accept, |
1da177e4 LT |
2379 | .ioctl = tcp_ioctl, |
2380 | .init = tcp_v4_init_sock, | |
2381 | .destroy = tcp_v4_destroy_sock, | |
2382 | .shutdown = tcp_shutdown, | |
2383 | .setsockopt = tcp_setsockopt, | |
2384 | .getsockopt = tcp_getsockopt, | |
4b9d07a4 | 2385 | .keepalive = tcp_set_keepalive, |
1da177e4 | 2386 | .recvmsg = tcp_recvmsg, |
7ba42910 CG |
2387 | .sendmsg = tcp_sendmsg, |
2388 | .sendpage = tcp_sendpage, | |
1da177e4 | 2389 | .backlog_rcv = tcp_v4_do_rcv, |
46d3ceab | 2390 | .release_cb = tcp_release_cb, |
ab1e0a13 ACM |
2391 | .hash = inet_hash, |
2392 | .unhash = inet_unhash, | |
2393 | .get_port = inet_csk_get_port, | |
1da177e4 | 2394 | .enter_memory_pressure = tcp_enter_memory_pressure, |
c9bee3b7 | 2395 | .stream_memory_free = tcp_stream_memory_free, |
1da177e4 | 2396 | .sockets_allocated = &tcp_sockets_allocated, |
0a5578cf | 2397 | .orphan_count = &tcp_orphan_count, |
1da177e4 LT |
2398 | .memory_allocated = &tcp_memory_allocated, |
2399 | .memory_pressure = &tcp_memory_pressure, | |
a4fe34bf | 2400 | .sysctl_mem = sysctl_tcp_mem, |
1da177e4 LT |
2401 | .sysctl_wmem = sysctl_tcp_wmem, |
2402 | .sysctl_rmem = sysctl_tcp_rmem, | |
2403 | .max_header = MAX_TCP_HEADER, | |
2404 | .obj_size = sizeof(struct tcp_sock), | |
3ab5aee7 | 2405 | .slab_flags = SLAB_DESTROY_BY_RCU, |
6d6ee43e | 2406 | .twsk_prot = &tcp_timewait_sock_ops, |
60236fdd | 2407 | .rsk_prot = &tcp_request_sock_ops, |
39d8cda7 | 2408 | .h.hashinfo = &tcp_hashinfo, |
7ba42910 | 2409 | .no_autobind = true, |
543d9cfe ACM |
2410 | #ifdef CONFIG_COMPAT |
2411 | .compat_setsockopt = compat_tcp_setsockopt, | |
2412 | .compat_getsockopt = compat_tcp_getsockopt, | |
d1a4c0b3 | 2413 | #endif |
c1e64e29 | 2414 | .diag_destroy = tcp_abort, |
1da177e4 | 2415 | }; |
4bc2f18b | 2416 | EXPORT_SYMBOL(tcp_prot); |
1da177e4 | 2417 | |
bdbbb852 ED |
2418 | static void __net_exit tcp_sk_exit(struct net *net) |
2419 | { | |
2420 | int cpu; | |
2421 | ||
2422 | for_each_possible_cpu(cpu) | |
2423 | inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.tcp_sk, cpu)); | |
2424 | free_percpu(net->ipv4.tcp_sk); | |
2425 | } | |
2426 | ||
046ee902 DL |
2427 | static int __net_init tcp_sk_init(struct net *net) |
2428 | { | |
fee83d09 | 2429 | int res, cpu, cnt; |
bdbbb852 ED |
2430 | |
2431 | net->ipv4.tcp_sk = alloc_percpu(struct sock *); | |
2432 | if (!net->ipv4.tcp_sk) | |
2433 | return -ENOMEM; | |
2434 | ||
2435 | for_each_possible_cpu(cpu) { | |
2436 | struct sock *sk; | |
2437 | ||
2438 | res = inet_ctl_sock_create(&sk, PF_INET, SOCK_RAW, | |
2439 | IPPROTO_TCP, net); | |
2440 | if (res) | |
2441 | goto fail; | |
a9d6532b | 2442 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); |
bdbbb852 ED |
2443 | *per_cpu_ptr(net->ipv4.tcp_sk, cpu) = sk; |
2444 | } | |
49213555 | 2445 | |
5d134f1c | 2446 | net->ipv4.sysctl_tcp_ecn = 2; |
49213555 DB |
2447 | net->ipv4.sysctl_tcp_ecn_fallback = 1; |
2448 | ||
b0f9ca53 | 2449 | net->ipv4.sysctl_tcp_base_mss = TCP_BASE_MSS; |
6b58e0a5 | 2450 | net->ipv4.sysctl_tcp_probe_threshold = TCP_PROBE_THRESHOLD; |
05cbc0db | 2451 | net->ipv4.sysctl_tcp_probe_interval = TCP_PROBE_INTERVAL; |
046ee902 | 2452 | |
13b287e8 | 2453 | net->ipv4.sysctl_tcp_keepalive_time = TCP_KEEPALIVE_TIME; |
9bd6861b | 2454 | net->ipv4.sysctl_tcp_keepalive_probes = TCP_KEEPALIVE_PROBES; |
b840d15d | 2455 | net->ipv4.sysctl_tcp_keepalive_intvl = TCP_KEEPALIVE_INTVL; |
13b287e8 | 2456 | |
6fa25166 | 2457 | net->ipv4.sysctl_tcp_syn_retries = TCP_SYN_RETRIES; |
7c083ecb | 2458 | net->ipv4.sysctl_tcp_synack_retries = TCP_SYNACK_RETRIES; |
0aca737d | 2459 | net->ipv4.sysctl_tcp_syncookies = 1; |
1043e25f | 2460 | net->ipv4.sysctl_tcp_reordering = TCP_FASTRETRANS_THRESH; |
ae5c3f40 | 2461 | net->ipv4.sysctl_tcp_retries1 = TCP_RETR1; |
c6214a97 | 2462 | net->ipv4.sysctl_tcp_retries2 = TCP_RETR2; |
c402d9be | 2463 | net->ipv4.sysctl_tcp_orphan_retries = 0; |
1e579caa | 2464 | net->ipv4.sysctl_tcp_fin_timeout = TCP_FIN_TIMEOUT; |
4979f2d9 | 2465 | net->ipv4.sysctl_tcp_notsent_lowat = UINT_MAX; |
56ab6b93 | 2466 | net->ipv4.sysctl_tcp_tw_reuse = 0; |
12ed8244 | 2467 | |
fee83d09 | 2468 | cnt = tcp_hashinfo.ehash_mask + 1; |
1946e672 | 2469 | net->ipv4.tcp_death_row.sysctl_tw_recycle = 0; |
fee83d09 | 2470 | net->ipv4.tcp_death_row.sysctl_max_tw_buckets = (cnt + 1) / 2; |
1946e672 HY |
2471 | net->ipv4.tcp_death_row.hashinfo = &tcp_hashinfo; |
2472 | ||
fee83d09 HY |
2473 | net->ipv4.sysctl_max_syn_backlog = max(128, cnt / 256); |
2474 | ||
49213555 | 2475 | return 0; |
bdbbb852 ED |
2476 | fail: |
2477 | tcp_sk_exit(net); | |
2478 | ||
2479 | return res; | |
b099ce26 EB |
2480 | } |
2481 | ||
2482 | static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list) | |
2483 | { | |
1946e672 | 2484 | inet_twsk_purge(&tcp_hashinfo, AF_INET); |
046ee902 DL |
2485 | } |
2486 | ||
2487 | static struct pernet_operations __net_initdata tcp_sk_ops = { | |
b099ce26 EB |
2488 | .init = tcp_sk_init, |
2489 | .exit = tcp_sk_exit, | |
2490 | .exit_batch = tcp_sk_exit_batch, | |
046ee902 DL |
2491 | }; |
2492 | ||
9b0f976f | 2493 | void __init tcp_v4_init(void) |
1da177e4 | 2494 | { |
6a1b3054 | 2495 | if (register_pernet_subsys(&tcp_sk_ops)) |
1da177e4 | 2496 | panic("Failed to create the TCP control socket.\n"); |
1da177e4 | 2497 | } |