Commit | Line | Data |
---|---|---|
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> |
1a2449a8 | 75 | #include <net/netdma.h> |
6e5714ea | 76 | #include <net/secure_seq.h> |
d1a4c0b3 | 77 | #include <net/tcp_memcontrol.h> |
1da177e4 LT |
78 | |
79 | #include <linux/inet.h> | |
80 | #include <linux/ipv6.h> | |
81 | #include <linux/stddef.h> | |
82 | #include <linux/proc_fs.h> | |
83 | #include <linux/seq_file.h> | |
84 | ||
cfb6eeb4 YH |
85 | #include <linux/crypto.h> |
86 | #include <linux/scatterlist.h> | |
87 | ||
ab32ea5d BH |
88 | int sysctl_tcp_tw_reuse __read_mostly; |
89 | int sysctl_tcp_low_latency __read_mostly; | |
4bc2f18b | 90 | EXPORT_SYMBOL(sysctl_tcp_low_latency); |
1da177e4 | 91 | |
1da177e4 | 92 | |
cfb6eeb4 | 93 | #ifdef CONFIG_TCP_MD5SIG |
a915da9b | 94 | static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, |
318cf7aa | 95 | __be32 daddr, __be32 saddr, const struct tcphdr *th); |
cfb6eeb4 YH |
96 | #endif |
97 | ||
5caea4ea | 98 | struct inet_hashinfo tcp_hashinfo; |
4bc2f18b | 99 | EXPORT_SYMBOL(tcp_hashinfo); |
1da177e4 | 100 | |
cf533ea5 | 101 | static inline __u32 tcp_v4_init_sequence(const struct sk_buff *skb) |
1da177e4 | 102 | { |
eddc9ec5 ACM |
103 | return secure_tcp_sequence_number(ip_hdr(skb)->daddr, |
104 | ip_hdr(skb)->saddr, | |
aa8223c7 ACM |
105 | tcp_hdr(skb)->dest, |
106 | tcp_hdr(skb)->source); | |
1da177e4 LT |
107 | } |
108 | ||
6d6ee43e ACM |
109 | int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) |
110 | { | |
111 | const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw); | |
112 | struct tcp_sock *tp = tcp_sk(sk); | |
113 | ||
114 | /* With PAWS, it is safe from the viewpoint | |
115 | of data integrity. Even without PAWS it is safe provided sequence | |
116 | spaces do not overlap i.e. at data rates <= 80Mbit/sec. | |
117 | ||
118 | Actually, the idea is close to VJ's one, only timestamp cache is | |
119 | held not per host, but per port pair and TW bucket is used as state | |
120 | holder. | |
121 | ||
122 | If TW bucket has been already destroyed we fall back to VJ's scheme | |
123 | and use initial timestamp retrieved from peer table. | |
124 | */ | |
125 | if (tcptw->tw_ts_recent_stamp && | |
126 | (twp == NULL || (sysctl_tcp_tw_reuse && | |
9d729f72 | 127 | get_seconds() - tcptw->tw_ts_recent_stamp > 1))) { |
6d6ee43e ACM |
128 | tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2; |
129 | if (tp->write_seq == 0) | |
130 | tp->write_seq = 1; | |
131 | tp->rx_opt.ts_recent = tcptw->tw_ts_recent; | |
132 | tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; | |
133 | sock_hold(sktw); | |
134 | return 1; | |
135 | } | |
136 | ||
137 | return 0; | |
138 | } | |
6d6ee43e ACM |
139 | EXPORT_SYMBOL_GPL(tcp_twsk_unique); |
140 | ||
ee995283 PE |
141 | static int tcp_repair_connect(struct sock *sk) |
142 | { | |
143 | tcp_connect_init(sk); | |
144 | tcp_finish_connect(sk, NULL); | |
145 | ||
146 | return 0; | |
147 | } | |
148 | ||
1da177e4 LT |
149 | /* This will initiate an outgoing connection. */ |
150 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
151 | { | |
2d7192d6 | 152 | struct sockaddr_in *usin = (struct sockaddr_in *)uaddr; |
1da177e4 LT |
153 | struct inet_sock *inet = inet_sk(sk); |
154 | struct tcp_sock *tp = tcp_sk(sk); | |
dca8b089 | 155 | __be16 orig_sport, orig_dport; |
bada8adc | 156 | __be32 daddr, nexthop; |
da905bd1 | 157 | struct flowi4 *fl4; |
2d7192d6 | 158 | struct rtable *rt; |
1da177e4 | 159 | int err; |
f6d8bd05 | 160 | struct ip_options_rcu *inet_opt; |
1da177e4 LT |
161 | |
162 | if (addr_len < sizeof(struct sockaddr_in)) | |
163 | return -EINVAL; | |
164 | ||
165 | if (usin->sin_family != AF_INET) | |
166 | return -EAFNOSUPPORT; | |
167 | ||
168 | nexthop = daddr = usin->sin_addr.s_addr; | |
f6d8bd05 ED |
169 | inet_opt = rcu_dereference_protected(inet->inet_opt, |
170 | sock_owned_by_user(sk)); | |
171 | if (inet_opt && inet_opt->opt.srr) { | |
1da177e4 LT |
172 | if (!daddr) |
173 | return -EINVAL; | |
f6d8bd05 | 174 | nexthop = inet_opt->opt.faddr; |
1da177e4 LT |
175 | } |
176 | ||
dca8b089 DM |
177 | orig_sport = inet->inet_sport; |
178 | orig_dport = usin->sin_port; | |
da905bd1 DM |
179 | fl4 = &inet->cork.fl.u.ip4; |
180 | rt = ip_route_connect(fl4, nexthop, inet->inet_saddr, | |
b23dd4fe DM |
181 | RT_CONN_FLAGS(sk), sk->sk_bound_dev_if, |
182 | IPPROTO_TCP, | |
183 | orig_sport, orig_dport, sk, true); | |
184 | if (IS_ERR(rt)) { | |
185 | err = PTR_ERR(rt); | |
186 | if (err == -ENETUNREACH) | |
7c73a6fa | 187 | IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
b23dd4fe | 188 | return err; |
584bdf8c | 189 | } |
1da177e4 LT |
190 | |
191 | if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { | |
192 | ip_rt_put(rt); | |
193 | return -ENETUNREACH; | |
194 | } | |
195 | ||
f6d8bd05 | 196 | if (!inet_opt || !inet_opt->opt.srr) |
da905bd1 | 197 | daddr = fl4->daddr; |
1da177e4 | 198 | |
c720c7e8 | 199 | if (!inet->inet_saddr) |
da905bd1 | 200 | inet->inet_saddr = fl4->saddr; |
c720c7e8 | 201 | inet->inet_rcv_saddr = inet->inet_saddr; |
1da177e4 | 202 | |
c720c7e8 | 203 | if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) { |
1da177e4 LT |
204 | /* Reset inherited state */ |
205 | tp->rx_opt.ts_recent = 0; | |
206 | tp->rx_opt.ts_recent_stamp = 0; | |
ee995283 PE |
207 | if (likely(!tp->repair)) |
208 | tp->write_seq = 0; | |
1da177e4 LT |
209 | } |
210 | ||
295ff7ed | 211 | if (tcp_death_row.sysctl_tw_recycle && |
81166dd6 DM |
212 | !tp->rx_opt.ts_recent_stamp && fl4->daddr == daddr) |
213 | tcp_fetch_timewait_stamp(sk, &rt->dst); | |
1da177e4 | 214 | |
c720c7e8 ED |
215 | inet->inet_dport = usin->sin_port; |
216 | inet->inet_daddr = daddr; | |
1da177e4 | 217 | |
d83d8461 | 218 | inet_csk(sk)->icsk_ext_hdr_len = 0; |
f6d8bd05 ED |
219 | if (inet_opt) |
220 | inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen; | |
1da177e4 | 221 | |
bee7ca9e | 222 | tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT; |
1da177e4 LT |
223 | |
224 | /* Socket identity is still unknown (sport may be zero). | |
225 | * However we set state to SYN-SENT and not releasing socket | |
226 | * lock select source port, enter ourselves into the hash tables and | |
227 | * complete initialization after this. | |
228 | */ | |
229 | tcp_set_state(sk, TCP_SYN_SENT); | |
a7f5e7f1 | 230 | err = inet_hash_connect(&tcp_death_row, sk); |
1da177e4 LT |
231 | if (err) |
232 | goto failure; | |
233 | ||
da905bd1 | 234 | rt = ip_route_newports(fl4, rt, orig_sport, orig_dport, |
b23dd4fe DM |
235 | inet->inet_sport, inet->inet_dport, sk); |
236 | if (IS_ERR(rt)) { | |
237 | err = PTR_ERR(rt); | |
238 | rt = NULL; | |
1da177e4 | 239 | goto failure; |
b23dd4fe | 240 | } |
1da177e4 | 241 | /* OK, now commit destination to socket. */ |
bcd76111 | 242 | sk->sk_gso_type = SKB_GSO_TCPV4; |
d8d1f30b | 243 | sk_setup_caps(sk, &rt->dst); |
1da177e4 | 244 | |
ee995283 | 245 | if (!tp->write_seq && likely(!tp->repair)) |
c720c7e8 ED |
246 | tp->write_seq = secure_tcp_sequence_number(inet->inet_saddr, |
247 | inet->inet_daddr, | |
248 | inet->inet_sport, | |
1da177e4 LT |
249 | usin->sin_port); |
250 | ||
c720c7e8 | 251 | inet->inet_id = tp->write_seq ^ jiffies; |
1da177e4 | 252 | |
ee995283 PE |
253 | if (likely(!tp->repair)) |
254 | err = tcp_connect(sk); | |
255 | else | |
256 | err = tcp_repair_connect(sk); | |
257 | ||
1da177e4 LT |
258 | rt = NULL; |
259 | if (err) | |
260 | goto failure; | |
261 | ||
262 | return 0; | |
263 | ||
264 | failure: | |
7174259e ACM |
265 | /* |
266 | * This unhashes the socket and releases the local port, | |
267 | * if necessary. | |
268 | */ | |
1da177e4 LT |
269 | tcp_set_state(sk, TCP_CLOSE); |
270 | ip_rt_put(rt); | |
271 | sk->sk_route_caps = 0; | |
c720c7e8 | 272 | inet->inet_dport = 0; |
1da177e4 LT |
273 | return err; |
274 | } | |
4bc2f18b | 275 | EXPORT_SYMBOL(tcp_v4_connect); |
1da177e4 | 276 | |
1da177e4 LT |
277 | /* |
278 | * This routine does path mtu discovery as defined in RFC1191. | |
279 | */ | |
b71d1d42 | 280 | static void do_pmtu_discovery(struct sock *sk, const struct iphdr *iph, u32 mtu) |
1da177e4 LT |
281 | { |
282 | struct dst_entry *dst; | |
283 | struct inet_sock *inet = inet_sk(sk); | |
1da177e4 LT |
284 | |
285 | /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs | |
286 | * send out by Linux are always <576bytes so they should go through | |
287 | * unfragmented). | |
288 | */ | |
289 | if (sk->sk_state == TCP_LISTEN) | |
290 | return; | |
291 | ||
80d0a69f DM |
292 | dst = inet_csk_update_pmtu(sk, mtu); |
293 | if (!dst) | |
1da177e4 LT |
294 | return; |
295 | ||
1da177e4 LT |
296 | /* Something is about to be wrong... Remember soft error |
297 | * for the case, if this connection will not able to recover. | |
298 | */ | |
299 | if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst)) | |
300 | sk->sk_err_soft = EMSGSIZE; | |
301 | ||
302 | mtu = dst_mtu(dst); | |
303 | ||
304 | if (inet->pmtudisc != IP_PMTUDISC_DONT && | |
d83d8461 | 305 | inet_csk(sk)->icsk_pmtu_cookie > mtu) { |
1da177e4 LT |
306 | tcp_sync_mss(sk, mtu); |
307 | ||
308 | /* Resend the TCP packet because it's | |
309 | * clear that the old packet has been | |
310 | * dropped. This is the new "fast" path mtu | |
311 | * discovery. | |
312 | */ | |
313 | tcp_simple_retransmit(sk); | |
314 | } /* else let the usual retransmit timer handle it */ | |
315 | } | |
316 | ||
55be7a9c DM |
317 | static void do_redirect(struct sk_buff *skb, struct sock *sk) |
318 | { | |
319 | struct dst_entry *dst = __sk_dst_check(sk, 0); | |
320 | ||
1ed5c48f | 321 | if (dst) |
6700c270 | 322 | dst->ops->redirect(dst, sk, skb); |
55be7a9c DM |
323 | } |
324 | ||
1da177e4 LT |
325 | /* |
326 | * This routine is called by the ICMP module when it gets some | |
327 | * sort of error condition. If err < 0 then the socket should | |
328 | * be closed and the error returned to the user. If err > 0 | |
329 | * it's just the icmp type << 8 | icmp code. After adjustment | |
330 | * header points to the first 8 bytes of the tcp header. We need | |
331 | * to find the appropriate port. | |
332 | * | |
333 | * The locking strategy used here is very "optimistic". When | |
334 | * someone else accesses the socket the ICMP is just dropped | |
335 | * and for some paths there is no check at all. | |
336 | * A more general error queue to queue errors for later handling | |
337 | * is probably better. | |
338 | * | |
339 | */ | |
340 | ||
4d1a2d9e | 341 | void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) |
1da177e4 | 342 | { |
b71d1d42 | 343 | const struct iphdr *iph = (const struct iphdr *)icmp_skb->data; |
4d1a2d9e | 344 | struct tcphdr *th = (struct tcphdr *)(icmp_skb->data + (iph->ihl << 2)); |
f1ecd5d9 | 345 | struct inet_connection_sock *icsk; |
1da177e4 LT |
346 | struct tcp_sock *tp; |
347 | struct inet_sock *inet; | |
4d1a2d9e DL |
348 | const int type = icmp_hdr(icmp_skb)->type; |
349 | const int code = icmp_hdr(icmp_skb)->code; | |
1da177e4 | 350 | struct sock *sk; |
f1ecd5d9 | 351 | struct sk_buff *skb; |
1da177e4 | 352 | __u32 seq; |
f1ecd5d9 | 353 | __u32 remaining; |
1da177e4 | 354 | int err; |
4d1a2d9e | 355 | struct net *net = dev_net(icmp_skb->dev); |
1da177e4 | 356 | |
4d1a2d9e | 357 | if (icmp_skb->len < (iph->ihl << 2) + 8) { |
dcfc23ca | 358 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
359 | return; |
360 | } | |
361 | ||
fd54d716 | 362 | sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest, |
4d1a2d9e | 363 | iph->saddr, th->source, inet_iif(icmp_skb)); |
1da177e4 | 364 | if (!sk) { |
dcfc23ca | 365 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
366 | return; |
367 | } | |
368 | if (sk->sk_state == TCP_TIME_WAIT) { | |
9469c7b4 | 369 | inet_twsk_put(inet_twsk(sk)); |
1da177e4 LT |
370 | return; |
371 | } | |
372 | ||
373 | bh_lock_sock(sk); | |
374 | /* If too many ICMPs get dropped on busy | |
375 | * servers this needs to be solved differently. | |
376 | */ | |
377 | if (sock_owned_by_user(sk)) | |
de0744af | 378 | NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); |
1da177e4 LT |
379 | |
380 | if (sk->sk_state == TCP_CLOSE) | |
381 | goto out; | |
382 | ||
97e3ecd1 | 383 | if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { |
384 | NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP); | |
385 | goto out; | |
386 | } | |
387 | ||
f1ecd5d9 | 388 | icsk = inet_csk(sk); |
1da177e4 LT |
389 | tp = tcp_sk(sk); |
390 | seq = ntohl(th->seq); | |
391 | if (sk->sk_state != TCP_LISTEN && | |
392 | !between(seq, tp->snd_una, tp->snd_nxt)) { | |
de0744af | 393 | NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); |
1da177e4 LT |
394 | goto out; |
395 | } | |
396 | ||
397 | switch (type) { | |
55be7a9c DM |
398 | case ICMP_REDIRECT: |
399 | do_redirect(icmp_skb, sk); | |
400 | goto out; | |
1da177e4 LT |
401 | case ICMP_SOURCE_QUENCH: |
402 | /* Just silently ignore these. */ | |
403 | goto out; | |
404 | case ICMP_PARAMETERPROB: | |
405 | err = EPROTO; | |
406 | break; | |
407 | case ICMP_DEST_UNREACH: | |
408 | if (code > NR_ICMP_UNREACH) | |
409 | goto out; | |
410 | ||
411 | if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ | |
412 | if (!sock_owned_by_user(sk)) | |
413 | do_pmtu_discovery(sk, iph, info); | |
414 | goto out; | |
415 | } | |
416 | ||
417 | err = icmp_err_convert[code].errno; | |
f1ecd5d9 DL |
418 | /* check if icmp_skb allows revert of backoff |
419 | * (see draft-zimmermann-tcp-lcd) */ | |
420 | if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH) | |
421 | break; | |
422 | if (seq != tp->snd_una || !icsk->icsk_retransmits || | |
423 | !icsk->icsk_backoff) | |
424 | break; | |
425 | ||
8f49c270 DM |
426 | if (sock_owned_by_user(sk)) |
427 | break; | |
428 | ||
f1ecd5d9 | 429 | icsk->icsk_backoff--; |
9ad7c049 JC |
430 | inet_csk(sk)->icsk_rto = (tp->srtt ? __tcp_set_rto(tp) : |
431 | TCP_TIMEOUT_INIT) << icsk->icsk_backoff; | |
f1ecd5d9 DL |
432 | tcp_bound_rto(sk); |
433 | ||
434 | skb = tcp_write_queue_head(sk); | |
435 | BUG_ON(!skb); | |
436 | ||
437 | remaining = icsk->icsk_rto - min(icsk->icsk_rto, | |
438 | tcp_time_stamp - TCP_SKB_CB(skb)->when); | |
439 | ||
440 | if (remaining) { | |
441 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, | |
442 | remaining, TCP_RTO_MAX); | |
f1ecd5d9 DL |
443 | } else { |
444 | /* RTO revert clocked out retransmission. | |
445 | * Will retransmit now */ | |
446 | tcp_retransmit_timer(sk); | |
447 | } | |
448 | ||
1da177e4 LT |
449 | break; |
450 | case ICMP_TIME_EXCEEDED: | |
451 | err = EHOSTUNREACH; | |
452 | break; | |
453 | default: | |
454 | goto out; | |
455 | } | |
456 | ||
457 | switch (sk->sk_state) { | |
60236fdd | 458 | struct request_sock *req, **prev; |
1da177e4 LT |
459 | case TCP_LISTEN: |
460 | if (sock_owned_by_user(sk)) | |
461 | goto out; | |
462 | ||
463c84b9 ACM |
463 | req = inet_csk_search_req(sk, &prev, th->dest, |
464 | iph->daddr, iph->saddr); | |
1da177e4 LT |
465 | if (!req) |
466 | goto out; | |
467 | ||
468 | /* ICMPs are not backlogged, hence we cannot get | |
469 | an established socket here. | |
470 | */ | |
547b792c | 471 | WARN_ON(req->sk); |
1da177e4 | 472 | |
2e6599cb | 473 | if (seq != tcp_rsk(req)->snt_isn) { |
de0744af | 474 | NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); |
1da177e4 LT |
475 | goto out; |
476 | } | |
477 | ||
478 | /* | |
479 | * Still in SYN_RECV, just remove it silently. | |
480 | * There is no good way to pass the error to the newly | |
481 | * created socket, and POSIX does not want network | |
482 | * errors returned from accept(). | |
483 | */ | |
463c84b9 | 484 | inet_csk_reqsk_queue_drop(sk, req, prev); |
1da177e4 LT |
485 | goto out; |
486 | ||
487 | case TCP_SYN_SENT: | |
488 | case TCP_SYN_RECV: /* Cannot happen. | |
489 | It can f.e. if SYNs crossed. | |
490 | */ | |
491 | if (!sock_owned_by_user(sk)) { | |
1da177e4 LT |
492 | sk->sk_err = err; |
493 | ||
494 | sk->sk_error_report(sk); | |
495 | ||
496 | tcp_done(sk); | |
497 | } else { | |
498 | sk->sk_err_soft = err; | |
499 | } | |
500 | goto out; | |
501 | } | |
502 | ||
503 | /* If we've already connected we will keep trying | |
504 | * until we time out, or the user gives up. | |
505 | * | |
506 | * rfc1122 4.2.3.9 allows to consider as hard errors | |
507 | * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, | |
508 | * but it is obsoleted by pmtu discovery). | |
509 | * | |
510 | * Note, that in modern internet, where routing is unreliable | |
511 | * and in each dark corner broken firewalls sit, sending random | |
512 | * errors ordered by their masters even this two messages finally lose | |
513 | * their original sense (even Linux sends invalid PORT_UNREACHs) | |
514 | * | |
515 | * Now we are in compliance with RFCs. | |
516 | * --ANK (980905) | |
517 | */ | |
518 | ||
519 | inet = inet_sk(sk); | |
520 | if (!sock_owned_by_user(sk) && inet->recverr) { | |
521 | sk->sk_err = err; | |
522 | sk->sk_error_report(sk); | |
523 | } else { /* Only an error on timeout */ | |
524 | sk->sk_err_soft = err; | |
525 | } | |
526 | ||
527 | out: | |
528 | bh_unlock_sock(sk); | |
529 | sock_put(sk); | |
530 | } | |
531 | ||
419f9f89 HX |
532 | static void __tcp_v4_send_check(struct sk_buff *skb, |
533 | __be32 saddr, __be32 daddr) | |
1da177e4 | 534 | { |
aa8223c7 | 535 | struct tcphdr *th = tcp_hdr(skb); |
1da177e4 | 536 | |
84fa7933 | 537 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
419f9f89 | 538 | th->check = ~tcp_v4_check(skb->len, saddr, daddr, 0); |
663ead3b | 539 | skb->csum_start = skb_transport_header(skb) - skb->head; |
ff1dcadb | 540 | skb->csum_offset = offsetof(struct tcphdr, check); |
1da177e4 | 541 | } else { |
419f9f89 | 542 | th->check = tcp_v4_check(skb->len, saddr, daddr, |
07f0757a | 543 | csum_partial(th, |
1da177e4 LT |
544 | th->doff << 2, |
545 | skb->csum)); | |
546 | } | |
547 | } | |
548 | ||
419f9f89 | 549 | /* This routine computes an IPv4 TCP checksum. */ |
bb296246 | 550 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb) |
419f9f89 | 551 | { |
cf533ea5 | 552 | const struct inet_sock *inet = inet_sk(sk); |
419f9f89 HX |
553 | |
554 | __tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr); | |
555 | } | |
4bc2f18b | 556 | EXPORT_SYMBOL(tcp_v4_send_check); |
419f9f89 | 557 | |
a430a43d HX |
558 | int tcp_v4_gso_send_check(struct sk_buff *skb) |
559 | { | |
eddc9ec5 | 560 | const struct iphdr *iph; |
a430a43d HX |
561 | struct tcphdr *th; |
562 | ||
563 | if (!pskb_may_pull(skb, sizeof(*th))) | |
564 | return -EINVAL; | |
565 | ||
eddc9ec5 | 566 | iph = ip_hdr(skb); |
aa8223c7 | 567 | th = tcp_hdr(skb); |
a430a43d HX |
568 | |
569 | th->check = 0; | |
84fa7933 | 570 | skb->ip_summed = CHECKSUM_PARTIAL; |
419f9f89 | 571 | __tcp_v4_send_check(skb, iph->saddr, iph->daddr); |
a430a43d HX |
572 | return 0; |
573 | } | |
574 | ||
1da177e4 LT |
575 | /* |
576 | * This routine will send an RST to the other tcp. | |
577 | * | |
578 | * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.) | |
579 | * for reset. | |
580 | * Answer: if a packet caused RST, it is not for a socket | |
581 | * existing in our system, if it is matched to a socket, | |
582 | * it is just duplicate segment or bug in other side's TCP. | |
583 | * So that we build reply only basing on parameters | |
584 | * arrived with segment. | |
585 | * Exception: precedence violation. We do not implement it in any case. | |
586 | */ | |
587 | ||
cfb6eeb4 | 588 | static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 589 | { |
cf533ea5 | 590 | const struct tcphdr *th = tcp_hdr(skb); |
cfb6eeb4 YH |
591 | struct { |
592 | struct tcphdr th; | |
593 | #ifdef CONFIG_TCP_MD5SIG | |
714e85be | 594 | __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)]; |
cfb6eeb4 YH |
595 | #endif |
596 | } rep; | |
1da177e4 | 597 | struct ip_reply_arg arg; |
cfb6eeb4 YH |
598 | #ifdef CONFIG_TCP_MD5SIG |
599 | struct tcp_md5sig_key *key; | |
658ddaaf SL |
600 | const __u8 *hash_location = NULL; |
601 | unsigned char newhash[16]; | |
602 | int genhash; | |
603 | struct sock *sk1 = NULL; | |
cfb6eeb4 | 604 | #endif |
a86b1e30 | 605 | struct net *net; |
1da177e4 LT |
606 | |
607 | /* Never send a reset in response to a reset. */ | |
608 | if (th->rst) | |
609 | return; | |
610 | ||
511c3f92 | 611 | if (skb_rtable(skb)->rt_type != RTN_LOCAL) |
1da177e4 LT |
612 | return; |
613 | ||
614 | /* Swap the send and the receive. */ | |
cfb6eeb4 YH |
615 | memset(&rep, 0, sizeof(rep)); |
616 | rep.th.dest = th->source; | |
617 | rep.th.source = th->dest; | |
618 | rep.th.doff = sizeof(struct tcphdr) / 4; | |
619 | rep.th.rst = 1; | |
1da177e4 LT |
620 | |
621 | if (th->ack) { | |
cfb6eeb4 | 622 | rep.th.seq = th->ack_seq; |
1da177e4 | 623 | } else { |
cfb6eeb4 YH |
624 | rep.th.ack = 1; |
625 | rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin + | |
626 | skb->len - (th->doff << 2)); | |
1da177e4 LT |
627 | } |
628 | ||
7174259e | 629 | memset(&arg, 0, sizeof(arg)); |
cfb6eeb4 YH |
630 | arg.iov[0].iov_base = (unsigned char *)&rep; |
631 | arg.iov[0].iov_len = sizeof(rep.th); | |
632 | ||
633 | #ifdef CONFIG_TCP_MD5SIG | |
658ddaaf SL |
634 | hash_location = tcp_parse_md5sig_option(th); |
635 | if (!sk && hash_location) { | |
636 | /* | |
637 | * active side is lost. Try to find listening socket through | |
638 | * source port, and then find md5 key through listening socket. | |
639 | * we are not loose security here: | |
640 | * Incoming packet is checked with md5 hash with finding key, | |
641 | * no RST generated if md5 hash doesn't match. | |
642 | */ | |
643 | sk1 = __inet_lookup_listener(dev_net(skb_dst(skb)->dev), | |
644 | &tcp_hashinfo, ip_hdr(skb)->daddr, | |
645 | ntohs(th->source), inet_iif(skb)); | |
646 | /* don't send rst if it can't find key */ | |
647 | if (!sk1) | |
648 | return; | |
649 | rcu_read_lock(); | |
650 | key = tcp_md5_do_lookup(sk1, (union tcp_md5_addr *) | |
651 | &ip_hdr(skb)->saddr, AF_INET); | |
652 | if (!key) | |
653 | goto release_sk1; | |
654 | ||
655 | genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, NULL, skb); | |
656 | if (genhash || memcmp(hash_location, newhash, 16) != 0) | |
657 | goto release_sk1; | |
658 | } else { | |
659 | key = sk ? tcp_md5_do_lookup(sk, (union tcp_md5_addr *) | |
660 | &ip_hdr(skb)->saddr, | |
661 | AF_INET) : NULL; | |
662 | } | |
663 | ||
cfb6eeb4 YH |
664 | if (key) { |
665 | rep.opt[0] = htonl((TCPOPT_NOP << 24) | | |
666 | (TCPOPT_NOP << 16) | | |
667 | (TCPOPT_MD5SIG << 8) | | |
668 | TCPOLEN_MD5SIG); | |
669 | /* Update length and the length the header thinks exists */ | |
670 | arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; | |
671 | rep.th.doff = arg.iov[0].iov_len / 4; | |
672 | ||
49a72dfb | 673 | tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1], |
78e645cb IJ |
674 | key, ip_hdr(skb)->saddr, |
675 | ip_hdr(skb)->daddr, &rep.th); | |
cfb6eeb4 YH |
676 | } |
677 | #endif | |
eddc9ec5 ACM |
678 | arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, |
679 | ip_hdr(skb)->saddr, /* XXX */ | |
52cd5750 | 680 | arg.iov[0].iov_len, IPPROTO_TCP, 0); |
1da177e4 | 681 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; |
88ef4a5a | 682 | arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0; |
e2446eaa SL |
683 | /* When socket is gone, all binding information is lost. |
684 | * routing might fail in this case. using iif for oif to | |
685 | * make sure we can deliver it | |
686 | */ | |
687 | arg.bound_dev_if = sk ? sk->sk_bound_dev_if : inet_iif(skb); | |
1da177e4 | 688 | |
adf30907 | 689 | net = dev_net(skb_dst(skb)->dev); |
66b13d99 | 690 | arg.tos = ip_hdr(skb)->tos; |
70e73416 DM |
691 | ip_send_unicast_reply(net->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr, |
692 | ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len); | |
1da177e4 | 693 | |
63231bdd PE |
694 | TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS); |
695 | TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS); | |
658ddaaf SL |
696 | |
697 | #ifdef CONFIG_TCP_MD5SIG | |
698 | release_sk1: | |
699 | if (sk1) { | |
700 | rcu_read_unlock(); | |
701 | sock_put(sk1); | |
702 | } | |
703 | #endif | |
1da177e4 LT |
704 | } |
705 | ||
706 | /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states | |
707 | outside socket context is ugly, certainly. What can I do? | |
708 | */ | |
709 | ||
9501f972 YH |
710 | static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack, |
711 | u32 win, u32 ts, int oif, | |
88ef4a5a | 712 | struct tcp_md5sig_key *key, |
66b13d99 | 713 | int reply_flags, u8 tos) |
1da177e4 | 714 | { |
cf533ea5 | 715 | const struct tcphdr *th = tcp_hdr(skb); |
1da177e4 LT |
716 | struct { |
717 | struct tcphdr th; | |
714e85be | 718 | __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2) |
cfb6eeb4 | 719 | #ifdef CONFIG_TCP_MD5SIG |
714e85be | 720 | + (TCPOLEN_MD5SIG_ALIGNED >> 2) |
cfb6eeb4 YH |
721 | #endif |
722 | ]; | |
1da177e4 LT |
723 | } rep; |
724 | struct ip_reply_arg arg; | |
adf30907 | 725 | struct net *net = dev_net(skb_dst(skb)->dev); |
1da177e4 LT |
726 | |
727 | memset(&rep.th, 0, sizeof(struct tcphdr)); | |
7174259e | 728 | memset(&arg, 0, sizeof(arg)); |
1da177e4 LT |
729 | |
730 | arg.iov[0].iov_base = (unsigned char *)&rep; | |
731 | arg.iov[0].iov_len = sizeof(rep.th); | |
732 | if (ts) { | |
cfb6eeb4 YH |
733 | rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
734 | (TCPOPT_TIMESTAMP << 8) | | |
735 | TCPOLEN_TIMESTAMP); | |
736 | rep.opt[1] = htonl(tcp_time_stamp); | |
737 | rep.opt[2] = htonl(ts); | |
cb48cfe8 | 738 | arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED; |
1da177e4 LT |
739 | } |
740 | ||
741 | /* Swap the send and the receive. */ | |
742 | rep.th.dest = th->source; | |
743 | rep.th.source = th->dest; | |
744 | rep.th.doff = arg.iov[0].iov_len / 4; | |
745 | rep.th.seq = htonl(seq); | |
746 | rep.th.ack_seq = htonl(ack); | |
747 | rep.th.ack = 1; | |
748 | rep.th.window = htons(win); | |
749 | ||
cfb6eeb4 | 750 | #ifdef CONFIG_TCP_MD5SIG |
cfb6eeb4 YH |
751 | if (key) { |
752 | int offset = (ts) ? 3 : 0; | |
753 | ||
754 | rep.opt[offset++] = htonl((TCPOPT_NOP << 24) | | |
755 | (TCPOPT_NOP << 16) | | |
756 | (TCPOPT_MD5SIG << 8) | | |
757 | TCPOLEN_MD5SIG); | |
758 | arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; | |
759 | rep.th.doff = arg.iov[0].iov_len/4; | |
760 | ||
49a72dfb | 761 | tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset], |
90b7e112 AL |
762 | key, ip_hdr(skb)->saddr, |
763 | ip_hdr(skb)->daddr, &rep.th); | |
cfb6eeb4 YH |
764 | } |
765 | #endif | |
88ef4a5a | 766 | arg.flags = reply_flags; |
eddc9ec5 ACM |
767 | arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, |
768 | ip_hdr(skb)->saddr, /* XXX */ | |
1da177e4 LT |
769 | arg.iov[0].iov_len, IPPROTO_TCP, 0); |
770 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; | |
9501f972 YH |
771 | if (oif) |
772 | arg.bound_dev_if = oif; | |
66b13d99 | 773 | arg.tos = tos; |
70e73416 DM |
774 | ip_send_unicast_reply(net->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr, |
775 | ip_hdr(skb)->daddr, &arg, arg.iov[0].iov_len); | |
1da177e4 | 776 | |
63231bdd | 777 | TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS); |
1da177e4 LT |
778 | } |
779 | ||
780 | static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) | |
781 | { | |
8feaf0c0 | 782 | struct inet_timewait_sock *tw = inet_twsk(sk); |
cfb6eeb4 | 783 | struct tcp_timewait_sock *tcptw = tcp_twsk(sk); |
1da177e4 | 784 | |
9501f972 | 785 | tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, |
7174259e | 786 | tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, |
9501f972 YH |
787 | tcptw->tw_ts_recent, |
788 | tw->tw_bound_dev_if, | |
88ef4a5a | 789 | tcp_twsk_md5_key(tcptw), |
66b13d99 ED |
790 | tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0, |
791 | tw->tw_tos | |
9501f972 | 792 | ); |
1da177e4 | 793 | |
8feaf0c0 | 794 | inet_twsk_put(tw); |
1da177e4 LT |
795 | } |
796 | ||
6edafaaf | 797 | static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, |
7174259e | 798 | struct request_sock *req) |
1da177e4 | 799 | { |
9501f972 | 800 | tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1, |
cfb6eeb4 | 801 | tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, |
9501f972 YH |
802 | req->ts_recent, |
803 | 0, | |
a915da9b ED |
804 | tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&ip_hdr(skb)->daddr, |
805 | AF_INET), | |
66b13d99 ED |
806 | inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0, |
807 | ip_hdr(skb)->tos); | |
1da177e4 LT |
808 | } |
809 | ||
1da177e4 | 810 | /* |
9bf1d83e | 811 | * Send a SYN-ACK after having received a SYN. |
60236fdd | 812 | * This still operates on a request_sock only, not on a big |
1da177e4 LT |
813 | * socket. |
814 | */ | |
72659ecc OP |
815 | static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst, |
816 | struct request_sock *req, | |
fff32699 | 817 | struct request_values *rvp, |
7586eceb ED |
818 | u16 queue_mapping, |
819 | bool nocache) | |
1da177e4 | 820 | { |
2e6599cb | 821 | const struct inet_request_sock *ireq = inet_rsk(req); |
6bd023f3 | 822 | struct flowi4 fl4; |
1da177e4 LT |
823 | int err = -1; |
824 | struct sk_buff * skb; | |
825 | ||
826 | /* First, grab a route. */ | |
7586eceb | 827 | if (!dst && (dst = inet_csk_route_req(sk, &fl4, req, nocache)) == NULL) |
fd80eb94 | 828 | return -1; |
1da177e4 | 829 | |
e6b4d113 | 830 | skb = tcp_make_synack(sk, dst, req, rvp); |
1da177e4 LT |
831 | |
832 | if (skb) { | |
419f9f89 | 833 | __tcp_v4_send_check(skb, ireq->loc_addr, ireq->rmt_addr); |
1da177e4 | 834 | |
fff32699 | 835 | skb_set_queue_mapping(skb, queue_mapping); |
2e6599cb ACM |
836 | err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr, |
837 | ireq->rmt_addr, | |
838 | ireq->opt); | |
b9df3cb8 | 839 | err = net_xmit_eval(err); |
1da177e4 LT |
840 | } |
841 | ||
1da177e4 LT |
842 | return err; |
843 | } | |
844 | ||
72659ecc | 845 | static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req, |
e6b4d113 | 846 | struct request_values *rvp) |
fd80eb94 | 847 | { |
72659ecc | 848 | TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); |
7586eceb | 849 | return tcp_v4_send_synack(sk, NULL, req, rvp, 0, false); |
fd80eb94 DL |
850 | } |
851 | ||
1da177e4 | 852 | /* |
60236fdd | 853 | * IPv4 request_sock destructor. |
1da177e4 | 854 | */ |
60236fdd | 855 | static void tcp_v4_reqsk_destructor(struct request_sock *req) |
1da177e4 | 856 | { |
a51482bd | 857 | kfree(inet_rsk(req)->opt); |
1da177e4 LT |
858 | } |
859 | ||
946cedcc | 860 | /* |
a2a385d6 | 861 | * Return true if a syncookie should be sent |
946cedcc | 862 | */ |
a2a385d6 | 863 | bool tcp_syn_flood_action(struct sock *sk, |
946cedcc ED |
864 | const struct sk_buff *skb, |
865 | const char *proto) | |
1da177e4 | 866 | { |
946cedcc | 867 | const char *msg = "Dropping request"; |
a2a385d6 | 868 | bool want_cookie = false; |
946cedcc ED |
869 | struct listen_sock *lopt; |
870 | ||
871 | ||
1da177e4 | 872 | |
2a1d4bd4 | 873 | #ifdef CONFIG_SYN_COOKIES |
946cedcc | 874 | if (sysctl_tcp_syncookies) { |
2a1d4bd4 | 875 | msg = "Sending cookies"; |
a2a385d6 | 876 | want_cookie = true; |
946cedcc ED |
877 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDOCOOKIES); |
878 | } else | |
80e40daa | 879 | #endif |
946cedcc ED |
880 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDROP); |
881 | ||
882 | lopt = inet_csk(sk)->icsk_accept_queue.listen_opt; | |
883 | if (!lopt->synflood_warned) { | |
884 | lopt->synflood_warned = 1; | |
afd46503 | 885 | pr_info("%s: Possible SYN flooding on port %d. %s. Check SNMP counters.\n", |
946cedcc ED |
886 | proto, ntohs(tcp_hdr(skb)->dest), msg); |
887 | } | |
888 | return want_cookie; | |
2a1d4bd4 | 889 | } |
946cedcc | 890 | EXPORT_SYMBOL(tcp_syn_flood_action); |
1da177e4 LT |
891 | |
892 | /* | |
60236fdd | 893 | * Save and compile IPv4 options into the request_sock if needed. |
1da177e4 | 894 | */ |
f6d8bd05 ED |
895 | static struct ip_options_rcu *tcp_v4_save_options(struct sock *sk, |
896 | struct sk_buff *skb) | |
1da177e4 | 897 | { |
f6d8bd05 ED |
898 | const struct ip_options *opt = &(IPCB(skb)->opt); |
899 | struct ip_options_rcu *dopt = NULL; | |
1da177e4 LT |
900 | |
901 | if (opt && opt->optlen) { | |
f6d8bd05 ED |
902 | int opt_size = sizeof(*dopt) + opt->optlen; |
903 | ||
1da177e4 LT |
904 | dopt = kmalloc(opt_size, GFP_ATOMIC); |
905 | if (dopt) { | |
f6d8bd05 | 906 | if (ip_options_echo(&dopt->opt, skb)) { |
1da177e4 LT |
907 | kfree(dopt); |
908 | dopt = NULL; | |
909 | } | |
910 | } | |
911 | } | |
912 | return dopt; | |
913 | } | |
914 | ||
cfb6eeb4 YH |
915 | #ifdef CONFIG_TCP_MD5SIG |
916 | /* | |
917 | * RFC2385 MD5 checksumming requires a mapping of | |
918 | * IP address->MD5 Key. | |
919 | * We need to maintain these in the sk structure. | |
920 | */ | |
921 | ||
922 | /* Find the Key structure for an address. */ | |
a915da9b ED |
923 | struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk, |
924 | const union tcp_md5_addr *addr, | |
925 | int family) | |
cfb6eeb4 YH |
926 | { |
927 | struct tcp_sock *tp = tcp_sk(sk); | |
a915da9b ED |
928 | struct tcp_md5sig_key *key; |
929 | struct hlist_node *pos; | |
930 | unsigned int size = sizeof(struct in_addr); | |
a8afca03 | 931 | struct tcp_md5sig_info *md5sig; |
cfb6eeb4 | 932 | |
a8afca03 ED |
933 | /* caller either holds rcu_read_lock() or socket lock */ |
934 | md5sig = rcu_dereference_check(tp->md5sig_info, | |
b4fb05ea ED |
935 | sock_owned_by_user(sk) || |
936 | lockdep_is_held(&sk->sk_lock.slock)); | |
a8afca03 | 937 | if (!md5sig) |
cfb6eeb4 | 938 | return NULL; |
a915da9b ED |
939 | #if IS_ENABLED(CONFIG_IPV6) |
940 | if (family == AF_INET6) | |
941 | size = sizeof(struct in6_addr); | |
942 | #endif | |
a8afca03 | 943 | hlist_for_each_entry_rcu(key, pos, &md5sig->head, node) { |
a915da9b ED |
944 | if (key->family != family) |
945 | continue; | |
946 | if (!memcmp(&key->addr, addr, size)) | |
947 | return key; | |
cfb6eeb4 YH |
948 | } |
949 | return NULL; | |
950 | } | |
a915da9b | 951 | EXPORT_SYMBOL(tcp_md5_do_lookup); |
cfb6eeb4 YH |
952 | |
953 | struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk, | |
954 | struct sock *addr_sk) | |
955 | { | |
a915da9b ED |
956 | union tcp_md5_addr *addr; |
957 | ||
958 | addr = (union tcp_md5_addr *)&inet_sk(addr_sk)->inet_daddr; | |
959 | return tcp_md5_do_lookup(sk, addr, AF_INET); | |
cfb6eeb4 | 960 | } |
cfb6eeb4 YH |
961 | EXPORT_SYMBOL(tcp_v4_md5_lookup); |
962 | ||
f5b99bcd AB |
963 | static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk, |
964 | struct request_sock *req) | |
cfb6eeb4 | 965 | { |
a915da9b ED |
966 | union tcp_md5_addr *addr; |
967 | ||
968 | addr = (union tcp_md5_addr *)&inet_rsk(req)->rmt_addr; | |
969 | return tcp_md5_do_lookup(sk, addr, AF_INET); | |
cfb6eeb4 YH |
970 | } |
971 | ||
972 | /* This can be called on a newly created socket, from other files */ | |
a915da9b ED |
973 | int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
974 | int family, const u8 *newkey, u8 newkeylen, gfp_t gfp) | |
cfb6eeb4 YH |
975 | { |
976 | /* Add Key to the list */ | |
b0a713e9 | 977 | struct tcp_md5sig_key *key; |
cfb6eeb4 | 978 | struct tcp_sock *tp = tcp_sk(sk); |
a915da9b | 979 | struct tcp_md5sig_info *md5sig; |
cfb6eeb4 | 980 | |
a915da9b | 981 | key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET); |
cfb6eeb4 YH |
982 | if (key) { |
983 | /* Pre-existing entry - just update that one. */ | |
a915da9b | 984 | memcpy(key->key, newkey, newkeylen); |
b0a713e9 | 985 | key->keylen = newkeylen; |
a915da9b ED |
986 | return 0; |
987 | } | |
260fcbeb | 988 | |
a8afca03 ED |
989 | md5sig = rcu_dereference_protected(tp->md5sig_info, |
990 | sock_owned_by_user(sk)); | |
a915da9b ED |
991 | if (!md5sig) { |
992 | md5sig = kmalloc(sizeof(*md5sig), gfp); | |
993 | if (!md5sig) | |
cfb6eeb4 | 994 | return -ENOMEM; |
cfb6eeb4 | 995 | |
a915da9b ED |
996 | sk_nocaps_add(sk, NETIF_F_GSO_MASK); |
997 | INIT_HLIST_HEAD(&md5sig->head); | |
a8afca03 | 998 | rcu_assign_pointer(tp->md5sig_info, md5sig); |
a915da9b | 999 | } |
cfb6eeb4 | 1000 | |
5f3d9cb2 | 1001 | key = sock_kmalloc(sk, sizeof(*key), gfp); |
a915da9b ED |
1002 | if (!key) |
1003 | return -ENOMEM; | |
1004 | if (hlist_empty(&md5sig->head) && !tcp_alloc_md5sig_pool(sk)) { | |
5f3d9cb2 | 1005 | sock_kfree_s(sk, key, sizeof(*key)); |
a915da9b | 1006 | return -ENOMEM; |
cfb6eeb4 | 1007 | } |
a915da9b ED |
1008 | |
1009 | memcpy(key->key, newkey, newkeylen); | |
1010 | key->keylen = newkeylen; | |
1011 | key->family = family; | |
1012 | memcpy(&key->addr, addr, | |
1013 | (family == AF_INET6) ? sizeof(struct in6_addr) : | |
1014 | sizeof(struct in_addr)); | |
1015 | hlist_add_head_rcu(&key->node, &md5sig->head); | |
cfb6eeb4 YH |
1016 | return 0; |
1017 | } | |
a915da9b | 1018 | EXPORT_SYMBOL(tcp_md5_do_add); |
cfb6eeb4 | 1019 | |
a915da9b | 1020 | int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family) |
cfb6eeb4 YH |
1021 | { |
1022 | struct tcp_sock *tp = tcp_sk(sk); | |
a915da9b | 1023 | struct tcp_md5sig_key *key; |
a8afca03 | 1024 | struct tcp_md5sig_info *md5sig; |
a915da9b ED |
1025 | |
1026 | key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET); | |
1027 | if (!key) | |
1028 | return -ENOENT; | |
1029 | hlist_del_rcu(&key->node); | |
5f3d9cb2 | 1030 | atomic_sub(sizeof(*key), &sk->sk_omem_alloc); |
a915da9b | 1031 | kfree_rcu(key, rcu); |
a8afca03 ED |
1032 | md5sig = rcu_dereference_protected(tp->md5sig_info, |
1033 | sock_owned_by_user(sk)); | |
1034 | if (hlist_empty(&md5sig->head)) | |
a915da9b ED |
1035 | tcp_free_md5sig_pool(); |
1036 | return 0; | |
cfb6eeb4 | 1037 | } |
a915da9b | 1038 | EXPORT_SYMBOL(tcp_md5_do_del); |
cfb6eeb4 | 1039 | |
a915da9b | 1040 | void tcp_clear_md5_list(struct sock *sk) |
cfb6eeb4 YH |
1041 | { |
1042 | struct tcp_sock *tp = tcp_sk(sk); | |
a915da9b ED |
1043 | struct tcp_md5sig_key *key; |
1044 | struct hlist_node *pos, *n; | |
a8afca03 | 1045 | struct tcp_md5sig_info *md5sig; |
cfb6eeb4 | 1046 | |
a8afca03 ED |
1047 | md5sig = rcu_dereference_protected(tp->md5sig_info, 1); |
1048 | ||
1049 | if (!hlist_empty(&md5sig->head)) | |
cfb6eeb4 | 1050 | tcp_free_md5sig_pool(); |
a8afca03 | 1051 | hlist_for_each_entry_safe(key, pos, n, &md5sig->head, node) { |
a915da9b | 1052 | hlist_del_rcu(&key->node); |
5f3d9cb2 | 1053 | atomic_sub(sizeof(*key), &sk->sk_omem_alloc); |
a915da9b | 1054 | kfree_rcu(key, rcu); |
cfb6eeb4 YH |
1055 | } |
1056 | } | |
1057 | ||
7174259e ACM |
1058 | static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval, |
1059 | int optlen) | |
cfb6eeb4 YH |
1060 | { |
1061 | struct tcp_md5sig cmd; | |
1062 | struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr; | |
cfb6eeb4 YH |
1063 | |
1064 | if (optlen < sizeof(cmd)) | |
1065 | return -EINVAL; | |
1066 | ||
7174259e | 1067 | if (copy_from_user(&cmd, optval, sizeof(cmd))) |
cfb6eeb4 YH |
1068 | return -EFAULT; |
1069 | ||
1070 | if (sin->sin_family != AF_INET) | |
1071 | return -EINVAL; | |
1072 | ||
a8afca03 | 1073 | if (!cmd.tcpm_key || !cmd.tcpm_keylen) |
a915da9b ED |
1074 | return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr, |
1075 | AF_INET); | |
cfb6eeb4 YH |
1076 | |
1077 | if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) | |
1078 | return -EINVAL; | |
1079 | ||
a915da9b ED |
1080 | return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr, |
1081 | AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, | |
1082 | GFP_KERNEL); | |
cfb6eeb4 YH |
1083 | } |
1084 | ||
49a72dfb AL |
1085 | static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp, |
1086 | __be32 daddr, __be32 saddr, int nbytes) | |
cfb6eeb4 | 1087 | { |
cfb6eeb4 | 1088 | struct tcp4_pseudohdr *bp; |
49a72dfb | 1089 | struct scatterlist sg; |
cfb6eeb4 YH |
1090 | |
1091 | bp = &hp->md5_blk.ip4; | |
cfb6eeb4 YH |
1092 | |
1093 | /* | |
49a72dfb | 1094 | * 1. the TCP pseudo-header (in the order: source IP address, |
cfb6eeb4 YH |
1095 | * destination IP address, zero-padded protocol number, and |
1096 | * segment length) | |
1097 | */ | |
1098 | bp->saddr = saddr; | |
1099 | bp->daddr = daddr; | |
1100 | bp->pad = 0; | |
076fb722 | 1101 | bp->protocol = IPPROTO_TCP; |
49a72dfb | 1102 | bp->len = cpu_to_be16(nbytes); |
c7da57a1 | 1103 | |
49a72dfb AL |
1104 | sg_init_one(&sg, bp, sizeof(*bp)); |
1105 | return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp)); | |
1106 | } | |
1107 | ||
a915da9b | 1108 | static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, |
318cf7aa | 1109 | __be32 daddr, __be32 saddr, const struct tcphdr *th) |
49a72dfb AL |
1110 | { |
1111 | struct tcp_md5sig_pool *hp; | |
1112 | struct hash_desc *desc; | |
1113 | ||
1114 | hp = tcp_get_md5sig_pool(); | |
1115 | if (!hp) | |
1116 | goto clear_hash_noput; | |
1117 | desc = &hp->md5_desc; | |
1118 | ||
1119 | if (crypto_hash_init(desc)) | |
1120 | goto clear_hash; | |
1121 | if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2)) | |
1122 | goto clear_hash; | |
1123 | if (tcp_md5_hash_header(hp, th)) | |
1124 | goto clear_hash; | |
1125 | if (tcp_md5_hash_key(hp, key)) | |
1126 | goto clear_hash; | |
1127 | if (crypto_hash_final(desc, md5_hash)) | |
cfb6eeb4 YH |
1128 | goto clear_hash; |
1129 | ||
cfb6eeb4 | 1130 | tcp_put_md5sig_pool(); |
cfb6eeb4 | 1131 | return 0; |
49a72dfb | 1132 | |
cfb6eeb4 YH |
1133 | clear_hash: |
1134 | tcp_put_md5sig_pool(); | |
1135 | clear_hash_noput: | |
1136 | memset(md5_hash, 0, 16); | |
49a72dfb | 1137 | return 1; |
cfb6eeb4 YH |
1138 | } |
1139 | ||
49a72dfb | 1140 | int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key, |
318cf7aa ED |
1141 | const struct sock *sk, const struct request_sock *req, |
1142 | const struct sk_buff *skb) | |
cfb6eeb4 | 1143 | { |
49a72dfb AL |
1144 | struct tcp_md5sig_pool *hp; |
1145 | struct hash_desc *desc; | |
318cf7aa | 1146 | const struct tcphdr *th = tcp_hdr(skb); |
cfb6eeb4 YH |
1147 | __be32 saddr, daddr; |
1148 | ||
1149 | if (sk) { | |
c720c7e8 ED |
1150 | saddr = inet_sk(sk)->inet_saddr; |
1151 | daddr = inet_sk(sk)->inet_daddr; | |
49a72dfb AL |
1152 | } else if (req) { |
1153 | saddr = inet_rsk(req)->loc_addr; | |
1154 | daddr = inet_rsk(req)->rmt_addr; | |
cfb6eeb4 | 1155 | } else { |
49a72dfb AL |
1156 | const struct iphdr *iph = ip_hdr(skb); |
1157 | saddr = iph->saddr; | |
1158 | daddr = iph->daddr; | |
cfb6eeb4 | 1159 | } |
49a72dfb AL |
1160 | |
1161 | hp = tcp_get_md5sig_pool(); | |
1162 | if (!hp) | |
1163 | goto clear_hash_noput; | |
1164 | desc = &hp->md5_desc; | |
1165 | ||
1166 | if (crypto_hash_init(desc)) | |
1167 | goto clear_hash; | |
1168 | ||
1169 | if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, skb->len)) | |
1170 | goto clear_hash; | |
1171 | if (tcp_md5_hash_header(hp, th)) | |
1172 | goto clear_hash; | |
1173 | if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2)) | |
1174 | goto clear_hash; | |
1175 | if (tcp_md5_hash_key(hp, key)) | |
1176 | goto clear_hash; | |
1177 | if (crypto_hash_final(desc, md5_hash)) | |
1178 | goto clear_hash; | |
1179 | ||
1180 | tcp_put_md5sig_pool(); | |
1181 | return 0; | |
1182 | ||
1183 | clear_hash: | |
1184 | tcp_put_md5sig_pool(); | |
1185 | clear_hash_noput: | |
1186 | memset(md5_hash, 0, 16); | |
1187 | return 1; | |
cfb6eeb4 | 1188 | } |
49a72dfb | 1189 | EXPORT_SYMBOL(tcp_v4_md5_hash_skb); |
cfb6eeb4 | 1190 | |
a2a385d6 | 1191 | static bool tcp_v4_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb) |
cfb6eeb4 YH |
1192 | { |
1193 | /* | |
1194 | * This gets called for each TCP segment that arrives | |
1195 | * so we want to be efficient. | |
1196 | * We have 3 drop cases: | |
1197 | * o No MD5 hash and one expected. | |
1198 | * o MD5 hash and we're not expecting one. | |
1199 | * o MD5 hash and its wrong. | |
1200 | */ | |
cf533ea5 | 1201 | const __u8 *hash_location = NULL; |
cfb6eeb4 | 1202 | struct tcp_md5sig_key *hash_expected; |
eddc9ec5 | 1203 | const struct iphdr *iph = ip_hdr(skb); |
cf533ea5 | 1204 | const struct tcphdr *th = tcp_hdr(skb); |
cfb6eeb4 | 1205 | int genhash; |
cfb6eeb4 YH |
1206 | unsigned char newhash[16]; |
1207 | ||
a915da9b ED |
1208 | hash_expected = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&iph->saddr, |
1209 | AF_INET); | |
7d5d5525 | 1210 | hash_location = tcp_parse_md5sig_option(th); |
cfb6eeb4 | 1211 | |
cfb6eeb4 YH |
1212 | /* We've parsed the options - do we have a hash? */ |
1213 | if (!hash_expected && !hash_location) | |
a2a385d6 | 1214 | return false; |
cfb6eeb4 YH |
1215 | |
1216 | if (hash_expected && !hash_location) { | |
785957d3 | 1217 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); |
a2a385d6 | 1218 | return true; |
cfb6eeb4 YH |
1219 | } |
1220 | ||
1221 | if (!hash_expected && hash_location) { | |
785957d3 | 1222 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); |
a2a385d6 | 1223 | return true; |
cfb6eeb4 YH |
1224 | } |
1225 | ||
1226 | /* Okay, so this is hash_expected and hash_location - | |
1227 | * so we need to calculate the checksum. | |
1228 | */ | |
49a72dfb AL |
1229 | genhash = tcp_v4_md5_hash_skb(newhash, |
1230 | hash_expected, | |
1231 | NULL, NULL, skb); | |
cfb6eeb4 YH |
1232 | |
1233 | if (genhash || memcmp(hash_location, newhash, 16) != 0) { | |
e87cc472 JP |
1234 | net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n", |
1235 | &iph->saddr, ntohs(th->source), | |
1236 | &iph->daddr, ntohs(th->dest), | |
1237 | genhash ? " tcp_v4_calc_md5_hash failed" | |
1238 | : ""); | |
a2a385d6 | 1239 | return true; |
cfb6eeb4 | 1240 | } |
a2a385d6 | 1241 | return false; |
cfb6eeb4 YH |
1242 | } |
1243 | ||
1244 | #endif | |
1245 | ||
72a3effa | 1246 | struct request_sock_ops tcp_request_sock_ops __read_mostly = { |
1da177e4 | 1247 | .family = PF_INET, |
2e6599cb | 1248 | .obj_size = sizeof(struct tcp_request_sock), |
72659ecc | 1249 | .rtx_syn_ack = tcp_v4_rtx_synack, |
60236fdd ACM |
1250 | .send_ack = tcp_v4_reqsk_send_ack, |
1251 | .destructor = tcp_v4_reqsk_destructor, | |
1da177e4 | 1252 | .send_reset = tcp_v4_send_reset, |
72659ecc | 1253 | .syn_ack_timeout = tcp_syn_ack_timeout, |
1da177e4 LT |
1254 | }; |
1255 | ||
cfb6eeb4 | 1256 | #ifdef CONFIG_TCP_MD5SIG |
b2e4b3de | 1257 | static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = { |
cfb6eeb4 | 1258 | .md5_lookup = tcp_v4_reqsk_md5_lookup, |
e3afe7b7 | 1259 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
cfb6eeb4 | 1260 | }; |
b6332e6c | 1261 | #endif |
cfb6eeb4 | 1262 | |
1da177e4 LT |
1263 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) |
1264 | { | |
4957faad | 1265 | struct tcp_extend_values tmp_ext; |
1da177e4 | 1266 | struct tcp_options_received tmp_opt; |
cf533ea5 | 1267 | const u8 *hash_location; |
60236fdd | 1268 | struct request_sock *req; |
e6b4d113 | 1269 | struct inet_request_sock *ireq; |
4957faad | 1270 | struct tcp_sock *tp = tcp_sk(sk); |
e6b4d113 | 1271 | struct dst_entry *dst = NULL; |
eddc9ec5 ACM |
1272 | __be32 saddr = ip_hdr(skb)->saddr; |
1273 | __be32 daddr = ip_hdr(skb)->daddr; | |
1da177e4 | 1274 | __u32 isn = TCP_SKB_CB(skb)->when; |
a2a385d6 | 1275 | bool want_cookie = false; |
1da177e4 LT |
1276 | |
1277 | /* Never answer to SYNs send to broadcast or multicast */ | |
511c3f92 | 1278 | if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) |
1da177e4 LT |
1279 | goto drop; |
1280 | ||
1281 | /* TW buckets are converted to open requests without | |
1282 | * limitations, they conserve resources and peer is | |
1283 | * evidently real one. | |
1284 | */ | |
463c84b9 | 1285 | if (inet_csk_reqsk_queue_is_full(sk) && !isn) { |
946cedcc ED |
1286 | want_cookie = tcp_syn_flood_action(sk, skb, "TCP"); |
1287 | if (!want_cookie) | |
1288 | goto drop; | |
1da177e4 LT |
1289 | } |
1290 | ||
1291 | /* Accept backlog is full. If we have already queued enough | |
1292 | * of warm entries in syn queue, drop request. It is better than | |
1293 | * clogging syn queue with openreqs with exponentially increasing | |
1294 | * timeout. | |
1295 | */ | |
463c84b9 | 1296 | if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) |
1da177e4 LT |
1297 | goto drop; |
1298 | ||
ce4a7d0d | 1299 | req = inet_reqsk_alloc(&tcp_request_sock_ops); |
1da177e4 LT |
1300 | if (!req) |
1301 | goto drop; | |
1302 | ||
cfb6eeb4 YH |
1303 | #ifdef CONFIG_TCP_MD5SIG |
1304 | tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops; | |
1305 | #endif | |
1306 | ||
1da177e4 | 1307 | tcp_clear_options(&tmp_opt); |
bee7ca9e | 1308 | tmp_opt.mss_clamp = TCP_MSS_DEFAULT; |
4957faad | 1309 | tmp_opt.user_mss = tp->rx_opt.user_mss; |
bb5b7c11 | 1310 | tcp_parse_options(skb, &tmp_opt, &hash_location, 0); |
4957faad WAS |
1311 | |
1312 | if (tmp_opt.cookie_plus > 0 && | |
1313 | tmp_opt.saw_tstamp && | |
1314 | !tp->rx_opt.cookie_out_never && | |
1315 | (sysctl_tcp_cookie_size > 0 || | |
1316 | (tp->cookie_values != NULL && | |
1317 | tp->cookie_values->cookie_desired > 0))) { | |
1318 | u8 *c; | |
1319 | u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS]; | |
1320 | int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE; | |
1321 | ||
1322 | if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0) | |
1323 | goto drop_and_release; | |
1324 | ||
1325 | /* Secret recipe starts with IP addresses */ | |
0eae88f3 ED |
1326 | *mess++ ^= (__force u32)daddr; |
1327 | *mess++ ^= (__force u32)saddr; | |
1da177e4 | 1328 | |
4957faad WAS |
1329 | /* plus variable length Initiator Cookie */ |
1330 | c = (u8 *)mess; | |
1331 | while (l-- > 0) | |
1332 | *c++ ^= *hash_location++; | |
1333 | ||
a2a385d6 | 1334 | want_cookie = false; /* not our kind of cookie */ |
4957faad WAS |
1335 | tmp_ext.cookie_out_never = 0; /* false */ |
1336 | tmp_ext.cookie_plus = tmp_opt.cookie_plus; | |
1337 | } else if (!tp->rx_opt.cookie_in_always) { | |
1338 | /* redundant indications, but ensure initialization. */ | |
1339 | tmp_ext.cookie_out_never = 1; /* true */ | |
1340 | tmp_ext.cookie_plus = 0; | |
1341 | } else { | |
1342 | goto drop_and_release; | |
1343 | } | |
1344 | tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always; | |
1da177e4 | 1345 | |
4dfc2817 | 1346 | if (want_cookie && !tmp_opt.saw_tstamp) |
1da177e4 | 1347 | tcp_clear_options(&tmp_opt); |
1da177e4 | 1348 | |
1da177e4 | 1349 | tmp_opt.tstamp_ok = tmp_opt.saw_tstamp; |
1da177e4 LT |
1350 | tcp_openreq_init(req, &tmp_opt, skb); |
1351 | ||
bb5b7c11 DM |
1352 | ireq = inet_rsk(req); |
1353 | ireq->loc_addr = daddr; | |
1354 | ireq->rmt_addr = saddr; | |
1355 | ireq->no_srccheck = inet_sk(sk)->transparent; | |
1356 | ireq->opt = tcp_v4_save_options(sk, skb); | |
1357 | ||
284904aa | 1358 | if (security_inet_conn_request(sk, skb, req)) |
bb5b7c11 | 1359 | goto drop_and_free; |
284904aa | 1360 | |
172d69e6 | 1361 | if (!want_cookie || tmp_opt.tstamp_ok) |
bd14b1b2 | 1362 | TCP_ECN_create_request(req, skb); |
1da177e4 LT |
1363 | |
1364 | if (want_cookie) { | |
1da177e4 | 1365 | isn = cookie_v4_init_sequence(sk, skb, &req->mss); |
172d69e6 | 1366 | req->cookie_ts = tmp_opt.tstamp_ok; |
1da177e4 | 1367 | } else if (!isn) { |
6bd023f3 | 1368 | struct flowi4 fl4; |
1da177e4 LT |
1369 | |
1370 | /* VJ's idea. We save last timestamp seen | |
1371 | * from the destination in peer table, when entering | |
1372 | * state TIME-WAIT, and check against it before | |
1373 | * accepting new connection request. | |
1374 | * | |
1375 | * If "isn" is not zero, this request hit alive | |
1376 | * timewait bucket, so that all the necessary checks | |
1377 | * are made in the function processing timewait state. | |
1378 | */ | |
1379 | if (tmp_opt.saw_tstamp && | |
295ff7ed | 1380 | tcp_death_row.sysctl_tw_recycle && |
7586eceb | 1381 | (dst = inet_csk_route_req(sk, &fl4, req, want_cookie)) != NULL && |
81166dd6 DM |
1382 | fl4.daddr == saddr) { |
1383 | if (!tcp_peer_is_proven(req, dst, true)) { | |
de0744af | 1384 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED); |
7cd04fa7 | 1385 | goto drop_and_release; |
1da177e4 LT |
1386 | } |
1387 | } | |
1388 | /* Kill the following clause, if you dislike this way. */ | |
1389 | else if (!sysctl_tcp_syncookies && | |
463c84b9 | 1390 | (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) < |
1da177e4 | 1391 | (sysctl_max_syn_backlog >> 2)) && |
81166dd6 | 1392 | !tcp_peer_is_proven(req, dst, false)) { |
1da177e4 LT |
1393 | /* Without syncookies last quarter of |
1394 | * backlog is filled with destinations, | |
1395 | * proven to be alive. | |
1396 | * It means that we continue to communicate | |
1397 | * to destinations, already remembered | |
1398 | * to the moment of synflood. | |
1399 | */ | |
afd46503 | 1400 | LIMIT_NETDEBUG(KERN_DEBUG pr_fmt("drop open request from %pI4/%u\n"), |
673d57e7 | 1401 | &saddr, ntohs(tcp_hdr(skb)->source)); |
7cd04fa7 | 1402 | goto drop_and_release; |
1da177e4 LT |
1403 | } |
1404 | ||
a94f723d | 1405 | isn = tcp_v4_init_sequence(skb); |
1da177e4 | 1406 | } |
2e6599cb | 1407 | tcp_rsk(req)->snt_isn = isn; |
9ad7c049 | 1408 | tcp_rsk(req)->snt_synack = tcp_time_stamp; |
1da177e4 | 1409 | |
72659ecc | 1410 | if (tcp_v4_send_synack(sk, dst, req, |
fff32699 | 1411 | (struct request_values *)&tmp_ext, |
7586eceb ED |
1412 | skb_get_queue_mapping(skb), |
1413 | want_cookie) || | |
4957faad | 1414 | want_cookie) |
1da177e4 LT |
1415 | goto drop_and_free; |
1416 | ||
7cd04fa7 | 1417 | inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); |
1da177e4 LT |
1418 | return 0; |
1419 | ||
7cd04fa7 DL |
1420 | drop_and_release: |
1421 | dst_release(dst); | |
1da177e4 | 1422 | drop_and_free: |
60236fdd | 1423 | reqsk_free(req); |
1da177e4 | 1424 | drop: |
1da177e4 LT |
1425 | return 0; |
1426 | } | |
4bc2f18b | 1427 | EXPORT_SYMBOL(tcp_v4_conn_request); |
1da177e4 LT |
1428 | |
1429 | ||
1430 | /* | |
1431 | * The three way handshake has completed - we got a valid synack - | |
1432 | * now create the new socket. | |
1433 | */ | |
1434 | struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, | |
60236fdd | 1435 | struct request_sock *req, |
1da177e4 LT |
1436 | struct dst_entry *dst) |
1437 | { | |
2e6599cb | 1438 | struct inet_request_sock *ireq; |
1da177e4 LT |
1439 | struct inet_sock *newinet; |
1440 | struct tcp_sock *newtp; | |
1441 | struct sock *newsk; | |
cfb6eeb4 YH |
1442 | #ifdef CONFIG_TCP_MD5SIG |
1443 | struct tcp_md5sig_key *key; | |
1444 | #endif | |
f6d8bd05 | 1445 | struct ip_options_rcu *inet_opt; |
1da177e4 LT |
1446 | |
1447 | if (sk_acceptq_is_full(sk)) | |
1448 | goto exit_overflow; | |
1449 | ||
1da177e4 LT |
1450 | newsk = tcp_create_openreq_child(sk, req, skb); |
1451 | if (!newsk) | |
093d2823 | 1452 | goto exit_nonewsk; |
1da177e4 | 1453 | |
bcd76111 | 1454 | newsk->sk_gso_type = SKB_GSO_TCPV4; |
1da177e4 LT |
1455 | |
1456 | newtp = tcp_sk(newsk); | |
1457 | newinet = inet_sk(newsk); | |
2e6599cb | 1458 | ireq = inet_rsk(req); |
c720c7e8 ED |
1459 | newinet->inet_daddr = ireq->rmt_addr; |
1460 | newinet->inet_rcv_saddr = ireq->loc_addr; | |
1461 | newinet->inet_saddr = ireq->loc_addr; | |
f6d8bd05 ED |
1462 | inet_opt = ireq->opt; |
1463 | rcu_assign_pointer(newinet->inet_opt, inet_opt); | |
2e6599cb | 1464 | ireq->opt = NULL; |
463c84b9 | 1465 | newinet->mc_index = inet_iif(skb); |
eddc9ec5 | 1466 | newinet->mc_ttl = ip_hdr(skb)->ttl; |
4c507d28 | 1467 | newinet->rcv_tos = ip_hdr(skb)->tos; |
d83d8461 | 1468 | inet_csk(newsk)->icsk_ext_hdr_len = 0; |
f6d8bd05 ED |
1469 | if (inet_opt) |
1470 | inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen; | |
c720c7e8 | 1471 | newinet->inet_id = newtp->write_seq ^ jiffies; |
1da177e4 | 1472 | |
dfd25fff ED |
1473 | if (!dst) { |
1474 | dst = inet_csk_route_child_sock(sk, newsk, req); | |
1475 | if (!dst) | |
1476 | goto put_and_exit; | |
1477 | } else { | |
1478 | /* syncookie case : see end of cookie_v4_check() */ | |
1479 | } | |
0e734419 DM |
1480 | sk_setup_caps(newsk, dst); |
1481 | ||
5d424d5a | 1482 | tcp_mtup_init(newsk); |
1da177e4 | 1483 | tcp_sync_mss(newsk, dst_mtu(dst)); |
0dbaee3b | 1484 | newtp->advmss = dst_metric_advmss(dst); |
f5fff5dc TQ |
1485 | if (tcp_sk(sk)->rx_opt.user_mss && |
1486 | tcp_sk(sk)->rx_opt.user_mss < newtp->advmss) | |
1487 | newtp->advmss = tcp_sk(sk)->rx_opt.user_mss; | |
1488 | ||
1da177e4 | 1489 | tcp_initialize_rcv_mss(newsk); |
9ad7c049 JC |
1490 | if (tcp_rsk(req)->snt_synack) |
1491 | tcp_valid_rtt_meas(newsk, | |
1492 | tcp_time_stamp - tcp_rsk(req)->snt_synack); | |
1493 | newtp->total_retrans = req->retrans; | |
1da177e4 | 1494 | |
cfb6eeb4 YH |
1495 | #ifdef CONFIG_TCP_MD5SIG |
1496 | /* Copy over the MD5 key from the original socket */ | |
a915da9b ED |
1497 | key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&newinet->inet_daddr, |
1498 | AF_INET); | |
c720c7e8 | 1499 | if (key != NULL) { |
cfb6eeb4 YH |
1500 | /* |
1501 | * We're using one, so create a matching key | |
1502 | * on the newsk structure. If we fail to get | |
1503 | * memory, then we end up not copying the key | |
1504 | * across. Shucks. | |
1505 | */ | |
a915da9b ED |
1506 | tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newinet->inet_daddr, |
1507 | AF_INET, key->key, key->keylen, GFP_ATOMIC); | |
a465419b | 1508 | sk_nocaps_add(newsk, NETIF_F_GSO_MASK); |
cfb6eeb4 YH |
1509 | } |
1510 | #endif | |
1511 | ||
0e734419 DM |
1512 | if (__inet_inherit_port(sk, newsk) < 0) |
1513 | goto put_and_exit; | |
9327f705 | 1514 | __inet_hash_nolisten(newsk, NULL); |
1da177e4 LT |
1515 | |
1516 | return newsk; | |
1517 | ||
1518 | exit_overflow: | |
de0744af | 1519 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); |
093d2823 BS |
1520 | exit_nonewsk: |
1521 | dst_release(dst); | |
1da177e4 | 1522 | exit: |
de0744af | 1523 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); |
1da177e4 | 1524 | return NULL; |
0e734419 | 1525 | put_and_exit: |
709e8697 | 1526 | tcp_clear_xmit_timers(newsk); |
d8a6e65f | 1527 | tcp_cleanup_congestion_control(newsk); |
918eb399 | 1528 | bh_unlock_sock(newsk); |
0e734419 DM |
1529 | sock_put(newsk); |
1530 | goto exit; | |
1da177e4 | 1531 | } |
4bc2f18b | 1532 | EXPORT_SYMBOL(tcp_v4_syn_recv_sock); |
1da177e4 LT |
1533 | |
1534 | static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb) | |
1535 | { | |
aa8223c7 | 1536 | struct tcphdr *th = tcp_hdr(skb); |
eddc9ec5 | 1537 | const struct iphdr *iph = ip_hdr(skb); |
1da177e4 | 1538 | struct sock *nsk; |
60236fdd | 1539 | struct request_sock **prev; |
1da177e4 | 1540 | /* Find possible connection requests. */ |
463c84b9 ACM |
1541 | struct request_sock *req = inet_csk_search_req(sk, &prev, th->source, |
1542 | iph->saddr, iph->daddr); | |
1da177e4 LT |
1543 | if (req) |
1544 | return tcp_check_req(sk, skb, req, prev); | |
1545 | ||
3b1e0a65 | 1546 | nsk = inet_lookup_established(sock_net(sk), &tcp_hashinfo, iph->saddr, |
c67499c0 | 1547 | th->source, iph->daddr, th->dest, inet_iif(skb)); |
1da177e4 LT |
1548 | |
1549 | if (nsk) { | |
1550 | if (nsk->sk_state != TCP_TIME_WAIT) { | |
1551 | bh_lock_sock(nsk); | |
1552 | return nsk; | |
1553 | } | |
9469c7b4 | 1554 | inet_twsk_put(inet_twsk(nsk)); |
1da177e4 LT |
1555 | return NULL; |
1556 | } | |
1557 | ||
1558 | #ifdef CONFIG_SYN_COOKIES | |
af9b4738 | 1559 | if (!th->syn) |
1da177e4 LT |
1560 | sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt)); |
1561 | #endif | |
1562 | return sk; | |
1563 | } | |
1564 | ||
b51655b9 | 1565 | static __sum16 tcp_v4_checksum_init(struct sk_buff *skb) |
1da177e4 | 1566 | { |
eddc9ec5 ACM |
1567 | const struct iphdr *iph = ip_hdr(skb); |
1568 | ||
84fa7933 | 1569 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
eddc9ec5 ACM |
1570 | if (!tcp_v4_check(skb->len, iph->saddr, |
1571 | iph->daddr, skb->csum)) { | |
fb286bb2 | 1572 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
1da177e4 | 1573 | return 0; |
fb286bb2 | 1574 | } |
1da177e4 | 1575 | } |
fb286bb2 | 1576 | |
eddc9ec5 | 1577 | skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, |
fb286bb2 HX |
1578 | skb->len, IPPROTO_TCP, 0); |
1579 | ||
1da177e4 | 1580 | if (skb->len <= 76) { |
fb286bb2 | 1581 | return __skb_checksum_complete(skb); |
1da177e4 LT |
1582 | } |
1583 | return 0; | |
1584 | } | |
1585 | ||
1586 | ||
1587 | /* The socket must have it's spinlock held when we get | |
1588 | * here. | |
1589 | * | |
1590 | * We have a potential double-lock case here, so even when | |
1591 | * doing backlog processing we use the BH locking scheme. | |
1592 | * This is because we cannot sleep with the original spinlock | |
1593 | * held. | |
1594 | */ | |
1595 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) | |
1596 | { | |
cfb6eeb4 YH |
1597 | struct sock *rsk; |
1598 | #ifdef CONFIG_TCP_MD5SIG | |
1599 | /* | |
1600 | * We really want to reject the packet as early as possible | |
1601 | * if: | |
1602 | * o We're expecting an MD5'd packet and this is no MD5 tcp option | |
1603 | * o There is an MD5 option and we're not expecting one | |
1604 | */ | |
7174259e | 1605 | if (tcp_v4_inbound_md5_hash(sk, skb)) |
cfb6eeb4 YH |
1606 | goto discard; |
1607 | #endif | |
1608 | ||
1da177e4 | 1609 | if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ |
bdeab991 | 1610 | sock_rps_save_rxhash(sk, skb); |
aa8223c7 | 1611 | if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) { |
cfb6eeb4 | 1612 | rsk = sk; |
1da177e4 | 1613 | goto reset; |
cfb6eeb4 | 1614 | } |
1da177e4 LT |
1615 | return 0; |
1616 | } | |
1617 | ||
ab6a5bb6 | 1618 | if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb)) |
1da177e4 LT |
1619 | goto csum_err; |
1620 | ||
1621 | if (sk->sk_state == TCP_LISTEN) { | |
1622 | struct sock *nsk = tcp_v4_hnd_req(sk, skb); | |
1623 | if (!nsk) | |
1624 | goto discard; | |
1625 | ||
1626 | if (nsk != sk) { | |
bdeab991 | 1627 | sock_rps_save_rxhash(nsk, skb); |
cfb6eeb4 YH |
1628 | if (tcp_child_process(sk, nsk, skb)) { |
1629 | rsk = nsk; | |
1da177e4 | 1630 | goto reset; |
cfb6eeb4 | 1631 | } |
1da177e4 LT |
1632 | return 0; |
1633 | } | |
ca55158c | 1634 | } else |
bdeab991 | 1635 | sock_rps_save_rxhash(sk, skb); |
ca55158c | 1636 | |
aa8223c7 | 1637 | if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) { |
cfb6eeb4 | 1638 | rsk = sk; |
1da177e4 | 1639 | goto reset; |
cfb6eeb4 | 1640 | } |
1da177e4 LT |
1641 | return 0; |
1642 | ||
1643 | reset: | |
cfb6eeb4 | 1644 | tcp_v4_send_reset(rsk, skb); |
1da177e4 LT |
1645 | discard: |
1646 | kfree_skb(skb); | |
1647 | /* Be careful here. If this function gets more complicated and | |
1648 | * gcc suffers from register pressure on the x86, sk (in %ebx) | |
1649 | * might be destroyed here. This current version compiles correctly, | |
1650 | * but you have been warned. | |
1651 | */ | |
1652 | return 0; | |
1653 | ||
1654 | csum_err: | |
63231bdd | 1655 | TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS); |
1da177e4 LT |
1656 | goto discard; |
1657 | } | |
4bc2f18b | 1658 | EXPORT_SYMBOL(tcp_v4_do_rcv); |
1da177e4 | 1659 | |
160eb5a6 | 1660 | void tcp_v4_early_demux(struct sk_buff *skb) |
41063e9d DM |
1661 | { |
1662 | struct net *net = dev_net(skb->dev); | |
1663 | const struct iphdr *iph; | |
1664 | const struct tcphdr *th; | |
fd62e09b | 1665 | struct net_device *dev; |
41063e9d | 1666 | struct sock *sk; |
41063e9d | 1667 | |
41063e9d | 1668 | if (skb->pkt_type != PACKET_HOST) |
160eb5a6 | 1669 | return; |
41063e9d DM |
1670 | |
1671 | if (!pskb_may_pull(skb, ip_hdrlen(skb) + sizeof(struct tcphdr))) | |
160eb5a6 | 1672 | return; |
41063e9d DM |
1673 | |
1674 | iph = ip_hdr(skb); | |
1675 | th = (struct tcphdr *) ((char *)iph + ip_hdrlen(skb)); | |
1676 | ||
1677 | if (th->doff < sizeof(struct tcphdr) / 4) | |
160eb5a6 | 1678 | return; |
41063e9d DM |
1679 | |
1680 | if (!pskb_may_pull(skb, ip_hdrlen(skb) + th->doff * 4)) | |
160eb5a6 | 1681 | return; |
41063e9d | 1682 | |
fd62e09b | 1683 | dev = skb->dev; |
41063e9d DM |
1684 | sk = __inet_lookup_established(net, &tcp_hashinfo, |
1685 | iph->saddr, th->source, | |
7011d085 | 1686 | iph->daddr, ntohs(th->dest), |
fd62e09b | 1687 | dev->ifindex); |
41063e9d DM |
1688 | if (sk) { |
1689 | skb->sk = sk; | |
1690 | skb->destructor = sock_edemux; | |
1691 | if (sk->sk_state != TCP_TIME_WAIT) { | |
1692 | struct dst_entry *dst = sk->sk_rx_dst; | |
1693 | if (dst) | |
1694 | dst = dst_check(dst, 0); | |
1695 | if (dst) { | |
fd62e09b DM |
1696 | struct rtable *rt = (struct rtable *) dst; |
1697 | ||
160eb5a6 | 1698 | if (rt->rt_iif == dev->ifindex) |
fd62e09b | 1699 | skb_dst_set_noref(skb, dst); |
41063e9d DM |
1700 | } |
1701 | } | |
1702 | } | |
41063e9d DM |
1703 | } |
1704 | ||
1da177e4 LT |
1705 | /* |
1706 | * From tcp_input.c | |
1707 | */ | |
1708 | ||
1709 | int tcp_v4_rcv(struct sk_buff *skb) | |
1710 | { | |
eddc9ec5 | 1711 | const struct iphdr *iph; |
cf533ea5 | 1712 | const struct tcphdr *th; |
1da177e4 LT |
1713 | struct sock *sk; |
1714 | int ret; | |
a86b1e30 | 1715 | struct net *net = dev_net(skb->dev); |
1da177e4 LT |
1716 | |
1717 | if (skb->pkt_type != PACKET_HOST) | |
1718 | goto discard_it; | |
1719 | ||
1720 | /* Count it even if it's bad */ | |
63231bdd | 1721 | TCP_INC_STATS_BH(net, TCP_MIB_INSEGS); |
1da177e4 LT |
1722 | |
1723 | if (!pskb_may_pull(skb, sizeof(struct tcphdr))) | |
1724 | goto discard_it; | |
1725 | ||
aa8223c7 | 1726 | th = tcp_hdr(skb); |
1da177e4 LT |
1727 | |
1728 | if (th->doff < sizeof(struct tcphdr) / 4) | |
1729 | goto bad_packet; | |
1730 | if (!pskb_may_pull(skb, th->doff * 4)) | |
1731 | goto discard_it; | |
1732 | ||
1733 | /* An explanation is required here, I think. | |
1734 | * Packet length and doff are validated by header prediction, | |
caa20d9a | 1735 | * provided case of th->doff==0 is eliminated. |
1da177e4 | 1736 | * So, we defer the checks. */ |
60476372 | 1737 | if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb)) |
1da177e4 LT |
1738 | goto bad_packet; |
1739 | ||
aa8223c7 | 1740 | th = tcp_hdr(skb); |
eddc9ec5 | 1741 | iph = ip_hdr(skb); |
1da177e4 LT |
1742 | TCP_SKB_CB(skb)->seq = ntohl(th->seq); |
1743 | TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + | |
1744 | skb->len - th->doff * 4); | |
1745 | TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); | |
1746 | TCP_SKB_CB(skb)->when = 0; | |
b82d1bb4 | 1747 | TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph); |
1da177e4 LT |
1748 | TCP_SKB_CB(skb)->sacked = 0; |
1749 | ||
9a1f27c4 | 1750 | sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest); |
1da177e4 LT |
1751 | if (!sk) |
1752 | goto no_tcp_socket; | |
1753 | ||
bb134d5d ED |
1754 | process: |
1755 | if (sk->sk_state == TCP_TIME_WAIT) | |
1756 | goto do_time_wait; | |
1757 | ||
6cce09f8 ED |
1758 | if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { |
1759 | NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP); | |
d218d111 | 1760 | goto discard_and_relse; |
6cce09f8 | 1761 | } |
d218d111 | 1762 | |
1da177e4 LT |
1763 | if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) |
1764 | goto discard_and_relse; | |
b59c2701 | 1765 | nf_reset(skb); |
1da177e4 | 1766 | |
fda9ef5d | 1767 | if (sk_filter(sk, skb)) |
1da177e4 LT |
1768 | goto discard_and_relse; |
1769 | ||
1770 | skb->dev = NULL; | |
1771 | ||
c6366184 | 1772 | bh_lock_sock_nested(sk); |
1da177e4 LT |
1773 | ret = 0; |
1774 | if (!sock_owned_by_user(sk)) { | |
1a2449a8 CL |
1775 | #ifdef CONFIG_NET_DMA |
1776 | struct tcp_sock *tp = tcp_sk(sk); | |
1777 | if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) | |
a2bd1140 | 1778 | tp->ucopy.dma_chan = net_dma_find_channel(); |
1a2449a8 | 1779 | if (tp->ucopy.dma_chan) |
1da177e4 | 1780 | ret = tcp_v4_do_rcv(sk, skb); |
1a2449a8 CL |
1781 | else |
1782 | #endif | |
1783 | { | |
1784 | if (!tcp_prequeue(sk, skb)) | |
ae8d7f88 | 1785 | ret = tcp_v4_do_rcv(sk, skb); |
1a2449a8 | 1786 | } |
da882c1f ED |
1787 | } else if (unlikely(sk_add_backlog(sk, skb, |
1788 | sk->sk_rcvbuf + sk->sk_sndbuf))) { | |
6b03a53a | 1789 | bh_unlock_sock(sk); |
6cce09f8 | 1790 | NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP); |
6b03a53a ZY |
1791 | goto discard_and_relse; |
1792 | } | |
1da177e4 LT |
1793 | bh_unlock_sock(sk); |
1794 | ||
1795 | sock_put(sk); | |
1796 | ||
1797 | return ret; | |
1798 | ||
1799 | no_tcp_socket: | |
1800 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) | |
1801 | goto discard_it; | |
1802 | ||
1803 | if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) { | |
1804 | bad_packet: | |
63231bdd | 1805 | TCP_INC_STATS_BH(net, TCP_MIB_INERRS); |
1da177e4 | 1806 | } else { |
cfb6eeb4 | 1807 | tcp_v4_send_reset(NULL, skb); |
1da177e4 LT |
1808 | } |
1809 | ||
1810 | discard_it: | |
1811 | /* Discard frame. */ | |
1812 | kfree_skb(skb); | |
e905a9ed | 1813 | return 0; |
1da177e4 LT |
1814 | |
1815 | discard_and_relse: | |
1816 | sock_put(sk); | |
1817 | goto discard_it; | |
1818 | ||
1819 | do_time_wait: | |
1820 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { | |
9469c7b4 | 1821 | inet_twsk_put(inet_twsk(sk)); |
1da177e4 LT |
1822 | goto discard_it; |
1823 | } | |
1824 | ||
1825 | if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) { | |
63231bdd | 1826 | TCP_INC_STATS_BH(net, TCP_MIB_INERRS); |
9469c7b4 | 1827 | inet_twsk_put(inet_twsk(sk)); |
1da177e4 LT |
1828 | goto discard_it; |
1829 | } | |
9469c7b4 | 1830 | switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { |
1da177e4 | 1831 | case TCP_TW_SYN: { |
c346dca1 | 1832 | struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev), |
c67499c0 | 1833 | &tcp_hashinfo, |
eddc9ec5 | 1834 | iph->daddr, th->dest, |
463c84b9 | 1835 | inet_iif(skb)); |
1da177e4 | 1836 | if (sk2) { |
9469c7b4 YH |
1837 | inet_twsk_deschedule(inet_twsk(sk), &tcp_death_row); |
1838 | inet_twsk_put(inet_twsk(sk)); | |
1da177e4 LT |
1839 | sk = sk2; |
1840 | goto process; | |
1841 | } | |
1842 | /* Fall through to ACK */ | |
1843 | } | |
1844 | case TCP_TW_ACK: | |
1845 | tcp_v4_timewait_ack(sk, skb); | |
1846 | break; | |
1847 | case TCP_TW_RST: | |
1848 | goto no_tcp_socket; | |
1849 | case TCP_TW_SUCCESS:; | |
1850 | } | |
1851 | goto discard_it; | |
1852 | } | |
1853 | ||
ccb7c410 DM |
1854 | static struct timewait_sock_ops tcp_timewait_sock_ops = { |
1855 | .twsk_obj_size = sizeof(struct tcp_timewait_sock), | |
1856 | .twsk_unique = tcp_twsk_unique, | |
1857 | .twsk_destructor= tcp_twsk_destructor, | |
ccb7c410 | 1858 | }; |
1da177e4 | 1859 | |
3b401a81 | 1860 | const struct inet_connection_sock_af_ops ipv4_specific = { |
543d9cfe ACM |
1861 | .queue_xmit = ip_queue_xmit, |
1862 | .send_check = tcp_v4_send_check, | |
1863 | .rebuild_header = inet_sk_rebuild_header, | |
1864 | .conn_request = tcp_v4_conn_request, | |
1865 | .syn_recv_sock = tcp_v4_syn_recv_sock, | |
543d9cfe ACM |
1866 | .net_header_len = sizeof(struct iphdr), |
1867 | .setsockopt = ip_setsockopt, | |
1868 | .getsockopt = ip_getsockopt, | |
1869 | .addr2sockaddr = inet_csk_addr2sockaddr, | |
1870 | .sockaddr_len = sizeof(struct sockaddr_in), | |
ab1e0a13 | 1871 | .bind_conflict = inet_csk_bind_conflict, |
3fdadf7d | 1872 | #ifdef CONFIG_COMPAT |
543d9cfe ACM |
1873 | .compat_setsockopt = compat_ip_setsockopt, |
1874 | .compat_getsockopt = compat_ip_getsockopt, | |
3fdadf7d | 1875 | #endif |
1da177e4 | 1876 | }; |
4bc2f18b | 1877 | EXPORT_SYMBOL(ipv4_specific); |
1da177e4 | 1878 | |
cfb6eeb4 | 1879 | #ifdef CONFIG_TCP_MD5SIG |
b2e4b3de | 1880 | static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = { |
cfb6eeb4 | 1881 | .md5_lookup = tcp_v4_md5_lookup, |
49a72dfb | 1882 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
cfb6eeb4 | 1883 | .md5_parse = tcp_v4_parse_md5_keys, |
cfb6eeb4 | 1884 | }; |
b6332e6c | 1885 | #endif |
cfb6eeb4 | 1886 | |
1da177e4 LT |
1887 | /* NOTE: A lot of things set to zero explicitly by call to |
1888 | * sk_alloc() so need not be done here. | |
1889 | */ | |
1890 | static int tcp_v4_init_sock(struct sock *sk) | |
1891 | { | |
6687e988 | 1892 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 | 1893 | |
900f65d3 | 1894 | tcp_init_sock(sk); |
1da177e4 | 1895 | |
8292a17a | 1896 | icsk->icsk_af_ops = &ipv4_specific; |
900f65d3 | 1897 | |
cfb6eeb4 | 1898 | #ifdef CONFIG_TCP_MD5SIG |
ac807fa8 | 1899 | tcp_sk(sk)->af_specific = &tcp_sock_ipv4_specific; |
cfb6eeb4 | 1900 | #endif |
1da177e4 | 1901 | |
1da177e4 LT |
1902 | return 0; |
1903 | } | |
1904 | ||
7d06b2e0 | 1905 | void tcp_v4_destroy_sock(struct sock *sk) |
1da177e4 LT |
1906 | { |
1907 | struct tcp_sock *tp = tcp_sk(sk); | |
1908 | ||
1909 | tcp_clear_xmit_timers(sk); | |
1910 | ||
6687e988 | 1911 | tcp_cleanup_congestion_control(sk); |
317a76f9 | 1912 | |
1da177e4 | 1913 | /* Cleanup up the write buffer. */ |
fe067e8a | 1914 | tcp_write_queue_purge(sk); |
1da177e4 LT |
1915 | |
1916 | /* Cleans up our, hopefully empty, out_of_order_queue. */ | |
e905a9ed | 1917 | __skb_queue_purge(&tp->out_of_order_queue); |
1da177e4 | 1918 | |
cfb6eeb4 YH |
1919 | #ifdef CONFIG_TCP_MD5SIG |
1920 | /* Clean up the MD5 key list, if any */ | |
1921 | if (tp->md5sig_info) { | |
a915da9b | 1922 | tcp_clear_md5_list(sk); |
a8afca03 | 1923 | kfree_rcu(tp->md5sig_info, rcu); |
cfb6eeb4 YH |
1924 | tp->md5sig_info = NULL; |
1925 | } | |
1926 | #endif | |
1927 | ||
1a2449a8 CL |
1928 | #ifdef CONFIG_NET_DMA |
1929 | /* Cleans up our sk_async_wait_queue */ | |
e905a9ed | 1930 | __skb_queue_purge(&sk->sk_async_wait_queue); |
1a2449a8 CL |
1931 | #endif |
1932 | ||
1da177e4 LT |
1933 | /* Clean prequeue, it must be empty really */ |
1934 | __skb_queue_purge(&tp->ucopy.prequeue); | |
1935 | ||
1936 | /* Clean up a referenced TCP bind bucket. */ | |
463c84b9 | 1937 | if (inet_csk(sk)->icsk_bind_hash) |
ab1e0a13 | 1938 | inet_put_port(sk); |
1da177e4 LT |
1939 | |
1940 | /* | |
1941 | * If sendmsg cached page exists, toss it. | |
1942 | */ | |
1943 | if (sk->sk_sndmsg_page) { | |
1944 | __free_page(sk->sk_sndmsg_page); | |
1945 | sk->sk_sndmsg_page = NULL; | |
1946 | } | |
1947 | ||
435cf559 WAS |
1948 | /* TCP Cookie Transactions */ |
1949 | if (tp->cookie_values != NULL) { | |
1950 | kref_put(&tp->cookie_values->kref, | |
1951 | tcp_cookie_values_release); | |
1952 | tp->cookie_values = NULL; | |
1953 | } | |
1954 | ||
180d8cd9 | 1955 | sk_sockets_allocated_dec(sk); |
d1a4c0b3 | 1956 | sock_release_memcg(sk); |
1da177e4 | 1957 | } |
1da177e4 LT |
1958 | EXPORT_SYMBOL(tcp_v4_destroy_sock); |
1959 | ||
1960 | #ifdef CONFIG_PROC_FS | |
1961 | /* Proc filesystem TCP sock list dumping. */ | |
1962 | ||
3ab5aee7 | 1963 | static inline struct inet_timewait_sock *tw_head(struct hlist_nulls_head *head) |
1da177e4 | 1964 | { |
3ab5aee7 | 1965 | return hlist_nulls_empty(head) ? NULL : |
8feaf0c0 | 1966 | list_entry(head->first, struct inet_timewait_sock, tw_node); |
1da177e4 LT |
1967 | } |
1968 | ||
8feaf0c0 | 1969 | static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw) |
1da177e4 | 1970 | { |
3ab5aee7 ED |
1971 | return !is_a_nulls(tw->tw_node.next) ? |
1972 | hlist_nulls_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL; | |
1da177e4 LT |
1973 | } |
1974 | ||
a8b690f9 TH |
1975 | /* |
1976 | * Get next listener socket follow cur. If cur is NULL, get first socket | |
1977 | * starting from bucket given in st->bucket; when st->bucket is zero the | |
1978 | * very first socket in the hash table is returned. | |
1979 | */ | |
1da177e4 LT |
1980 | static void *listening_get_next(struct seq_file *seq, void *cur) |
1981 | { | |
463c84b9 | 1982 | struct inet_connection_sock *icsk; |
c25eb3bf | 1983 | struct hlist_nulls_node *node; |
1da177e4 | 1984 | struct sock *sk = cur; |
5caea4ea | 1985 | struct inet_listen_hashbucket *ilb; |
5799de0b | 1986 | struct tcp_iter_state *st = seq->private; |
a4146b1b | 1987 | struct net *net = seq_file_net(seq); |
1da177e4 LT |
1988 | |
1989 | if (!sk) { | |
a8b690f9 | 1990 | ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
5caea4ea | 1991 | spin_lock_bh(&ilb->lock); |
c25eb3bf | 1992 | sk = sk_nulls_head(&ilb->head); |
a8b690f9 | 1993 | st->offset = 0; |
1da177e4 LT |
1994 | goto get_sk; |
1995 | } | |
5caea4ea | 1996 | ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
1da177e4 | 1997 | ++st->num; |
a8b690f9 | 1998 | ++st->offset; |
1da177e4 LT |
1999 | |
2000 | if (st->state == TCP_SEQ_STATE_OPENREQ) { | |
60236fdd | 2001 | struct request_sock *req = cur; |
1da177e4 | 2002 | |
72a3effa | 2003 | icsk = inet_csk(st->syn_wait_sk); |
1da177e4 LT |
2004 | req = req->dl_next; |
2005 | while (1) { | |
2006 | while (req) { | |
bdccc4ca | 2007 | if (req->rsk_ops->family == st->family) { |
1da177e4 LT |
2008 | cur = req; |
2009 | goto out; | |
2010 | } | |
2011 | req = req->dl_next; | |
2012 | } | |
72a3effa | 2013 | if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries) |
1da177e4 LT |
2014 | break; |
2015 | get_req: | |
463c84b9 | 2016 | req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket]; |
1da177e4 | 2017 | } |
1bde5ac4 | 2018 | sk = sk_nulls_next(st->syn_wait_sk); |
1da177e4 | 2019 | st->state = TCP_SEQ_STATE_LISTENING; |
463c84b9 | 2020 | read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
1da177e4 | 2021 | } else { |
e905a9ed | 2022 | icsk = inet_csk(sk); |
463c84b9 ACM |
2023 | read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
2024 | if (reqsk_queue_len(&icsk->icsk_accept_queue)) | |
1da177e4 | 2025 | goto start_req; |
463c84b9 | 2026 | read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
1bde5ac4 | 2027 | sk = sk_nulls_next(sk); |
1da177e4 LT |
2028 | } |
2029 | get_sk: | |
c25eb3bf | 2030 | sk_nulls_for_each_from(sk, node) { |
8475ef9f PE |
2031 | if (!net_eq(sock_net(sk), net)) |
2032 | continue; | |
2033 | if (sk->sk_family == st->family) { | |
1da177e4 LT |
2034 | cur = sk; |
2035 | goto out; | |
2036 | } | |
e905a9ed | 2037 | icsk = inet_csk(sk); |
463c84b9 ACM |
2038 | read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
2039 | if (reqsk_queue_len(&icsk->icsk_accept_queue)) { | |
1da177e4 LT |
2040 | start_req: |
2041 | st->uid = sock_i_uid(sk); | |
2042 | st->syn_wait_sk = sk; | |
2043 | st->state = TCP_SEQ_STATE_OPENREQ; | |
2044 | st->sbucket = 0; | |
2045 | goto get_req; | |
2046 | } | |
463c84b9 | 2047 | read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
1da177e4 | 2048 | } |
5caea4ea | 2049 | spin_unlock_bh(&ilb->lock); |
a8b690f9 | 2050 | st->offset = 0; |
0f7ff927 | 2051 | if (++st->bucket < INET_LHTABLE_SIZE) { |
5caea4ea ED |
2052 | ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
2053 | spin_lock_bh(&ilb->lock); | |
c25eb3bf | 2054 | sk = sk_nulls_head(&ilb->head); |
1da177e4 LT |
2055 | goto get_sk; |
2056 | } | |
2057 | cur = NULL; | |
2058 | out: | |
2059 | return cur; | |
2060 | } | |
2061 | ||
2062 | static void *listening_get_idx(struct seq_file *seq, loff_t *pos) | |
2063 | { | |
a8b690f9 TH |
2064 | struct tcp_iter_state *st = seq->private; |
2065 | void *rc; | |
2066 | ||
2067 | st->bucket = 0; | |
2068 | st->offset = 0; | |
2069 | rc = listening_get_next(seq, NULL); | |
1da177e4 LT |
2070 | |
2071 | while (rc && *pos) { | |
2072 | rc = listening_get_next(seq, rc); | |
2073 | --*pos; | |
2074 | } | |
2075 | return rc; | |
2076 | } | |
2077 | ||
a2a385d6 | 2078 | static inline bool empty_bucket(struct tcp_iter_state *st) |
6eac5604 | 2079 | { |
3ab5aee7 ED |
2080 | return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain) && |
2081 | hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].twchain); | |
6eac5604 AK |
2082 | } |
2083 | ||
a8b690f9 TH |
2084 | /* |
2085 | * Get first established socket starting from bucket given in st->bucket. | |
2086 | * If st->bucket is zero, the very first socket in the hash is returned. | |
2087 | */ | |
1da177e4 LT |
2088 | static void *established_get_first(struct seq_file *seq) |
2089 | { | |
5799de0b | 2090 | struct tcp_iter_state *st = seq->private; |
a4146b1b | 2091 | struct net *net = seq_file_net(seq); |
1da177e4 LT |
2092 | void *rc = NULL; |
2093 | ||
a8b690f9 TH |
2094 | st->offset = 0; |
2095 | for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) { | |
1da177e4 | 2096 | struct sock *sk; |
3ab5aee7 | 2097 | struct hlist_nulls_node *node; |
8feaf0c0 | 2098 | struct inet_timewait_sock *tw; |
9db66bdc | 2099 | spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket); |
1da177e4 | 2100 | |
6eac5604 AK |
2101 | /* Lockless fast path for the common case of empty buckets */ |
2102 | if (empty_bucket(st)) | |
2103 | continue; | |
2104 | ||
9db66bdc | 2105 | spin_lock_bh(lock); |
3ab5aee7 | 2106 | sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) { |
f40c8174 | 2107 | if (sk->sk_family != st->family || |
878628fb | 2108 | !net_eq(sock_net(sk), net)) { |
1da177e4 LT |
2109 | continue; |
2110 | } | |
2111 | rc = sk; | |
2112 | goto out; | |
2113 | } | |
2114 | st->state = TCP_SEQ_STATE_TIME_WAIT; | |
8feaf0c0 | 2115 | inet_twsk_for_each(tw, node, |
dbca9b27 | 2116 | &tcp_hashinfo.ehash[st->bucket].twchain) { |
28518fc1 | 2117 | if (tw->tw_family != st->family || |
878628fb | 2118 | !net_eq(twsk_net(tw), net)) { |
1da177e4 LT |
2119 | continue; |
2120 | } | |
2121 | rc = tw; | |
2122 | goto out; | |
2123 | } | |
9db66bdc | 2124 | spin_unlock_bh(lock); |
1da177e4 LT |
2125 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2126 | } | |
2127 | out: | |
2128 | return rc; | |
2129 | } | |
2130 | ||
2131 | static void *established_get_next(struct seq_file *seq, void *cur) | |
2132 | { | |
2133 | struct sock *sk = cur; | |
8feaf0c0 | 2134 | struct inet_timewait_sock *tw; |
3ab5aee7 | 2135 | struct hlist_nulls_node *node; |
5799de0b | 2136 | struct tcp_iter_state *st = seq->private; |
a4146b1b | 2137 | struct net *net = seq_file_net(seq); |
1da177e4 LT |
2138 | |
2139 | ++st->num; | |
a8b690f9 | 2140 | ++st->offset; |
1da177e4 LT |
2141 | |
2142 | if (st->state == TCP_SEQ_STATE_TIME_WAIT) { | |
2143 | tw = cur; | |
2144 | tw = tw_next(tw); | |
2145 | get_tw: | |
878628fb | 2146 | while (tw && (tw->tw_family != st->family || !net_eq(twsk_net(tw), net))) { |
1da177e4 LT |
2147 | tw = tw_next(tw); |
2148 | } | |
2149 | if (tw) { | |
2150 | cur = tw; | |
2151 | goto out; | |
2152 | } | |
9db66bdc | 2153 | spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); |
1da177e4 LT |
2154 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2155 | ||
6eac5604 | 2156 | /* Look for next non empty bucket */ |
a8b690f9 | 2157 | st->offset = 0; |
f373b53b | 2158 | while (++st->bucket <= tcp_hashinfo.ehash_mask && |
6eac5604 AK |
2159 | empty_bucket(st)) |
2160 | ; | |
f373b53b | 2161 | if (st->bucket > tcp_hashinfo.ehash_mask) |
6eac5604 AK |
2162 | return NULL; |
2163 | ||
9db66bdc | 2164 | spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); |
3ab5aee7 | 2165 | sk = sk_nulls_head(&tcp_hashinfo.ehash[st->bucket].chain); |
1da177e4 | 2166 | } else |
3ab5aee7 | 2167 | sk = sk_nulls_next(sk); |
1da177e4 | 2168 | |
3ab5aee7 | 2169 | sk_nulls_for_each_from(sk, node) { |
878628fb | 2170 | if (sk->sk_family == st->family && net_eq(sock_net(sk), net)) |
1da177e4 LT |
2171 | goto found; |
2172 | } | |
2173 | ||
2174 | st->state = TCP_SEQ_STATE_TIME_WAIT; | |
dbca9b27 | 2175 | tw = tw_head(&tcp_hashinfo.ehash[st->bucket].twchain); |
1da177e4 LT |
2176 | goto get_tw; |
2177 | found: | |
2178 | cur = sk; | |
2179 | out: | |
2180 | return cur; | |
2181 | } | |
2182 | ||
2183 | static void *established_get_idx(struct seq_file *seq, loff_t pos) | |
2184 | { | |
a8b690f9 TH |
2185 | struct tcp_iter_state *st = seq->private; |
2186 | void *rc; | |
2187 | ||
2188 | st->bucket = 0; | |
2189 | rc = established_get_first(seq); | |
1da177e4 LT |
2190 | |
2191 | while (rc && pos) { | |
2192 | rc = established_get_next(seq, rc); | |
2193 | --pos; | |
7174259e | 2194 | } |
1da177e4 LT |
2195 | return rc; |
2196 | } | |
2197 | ||
2198 | static void *tcp_get_idx(struct seq_file *seq, loff_t pos) | |
2199 | { | |
2200 | void *rc; | |
5799de0b | 2201 | struct tcp_iter_state *st = seq->private; |
1da177e4 | 2202 | |
1da177e4 LT |
2203 | st->state = TCP_SEQ_STATE_LISTENING; |
2204 | rc = listening_get_idx(seq, &pos); | |
2205 | ||
2206 | if (!rc) { | |
1da177e4 LT |
2207 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2208 | rc = established_get_idx(seq, pos); | |
2209 | } | |
2210 | ||
2211 | return rc; | |
2212 | } | |
2213 | ||
a8b690f9 TH |
2214 | static void *tcp_seek_last_pos(struct seq_file *seq) |
2215 | { | |
2216 | struct tcp_iter_state *st = seq->private; | |
2217 | int offset = st->offset; | |
2218 | int orig_num = st->num; | |
2219 | void *rc = NULL; | |
2220 | ||
2221 | switch (st->state) { | |
2222 | case TCP_SEQ_STATE_OPENREQ: | |
2223 | case TCP_SEQ_STATE_LISTENING: | |
2224 | if (st->bucket >= INET_LHTABLE_SIZE) | |
2225 | break; | |
2226 | st->state = TCP_SEQ_STATE_LISTENING; | |
2227 | rc = listening_get_next(seq, NULL); | |
2228 | while (offset-- && rc) | |
2229 | rc = listening_get_next(seq, rc); | |
2230 | if (rc) | |
2231 | break; | |
2232 | st->bucket = 0; | |
2233 | /* Fallthrough */ | |
2234 | case TCP_SEQ_STATE_ESTABLISHED: | |
2235 | case TCP_SEQ_STATE_TIME_WAIT: | |
2236 | st->state = TCP_SEQ_STATE_ESTABLISHED; | |
2237 | if (st->bucket > tcp_hashinfo.ehash_mask) | |
2238 | break; | |
2239 | rc = established_get_first(seq); | |
2240 | while (offset-- && rc) | |
2241 | rc = established_get_next(seq, rc); | |
2242 | } | |
2243 | ||
2244 | st->num = orig_num; | |
2245 | ||
2246 | return rc; | |
2247 | } | |
2248 | ||
1da177e4 LT |
2249 | static void *tcp_seq_start(struct seq_file *seq, loff_t *pos) |
2250 | { | |
5799de0b | 2251 | struct tcp_iter_state *st = seq->private; |
a8b690f9 TH |
2252 | void *rc; |
2253 | ||
2254 | if (*pos && *pos == st->last_pos) { | |
2255 | rc = tcp_seek_last_pos(seq); | |
2256 | if (rc) | |
2257 | goto out; | |
2258 | } | |
2259 | ||
1da177e4 LT |
2260 | st->state = TCP_SEQ_STATE_LISTENING; |
2261 | st->num = 0; | |
a8b690f9 TH |
2262 | st->bucket = 0; |
2263 | st->offset = 0; | |
2264 | rc = *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
2265 | ||
2266 | out: | |
2267 | st->last_pos = *pos; | |
2268 | return rc; | |
1da177e4 LT |
2269 | } |
2270 | ||
2271 | static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2272 | { | |
a8b690f9 | 2273 | struct tcp_iter_state *st = seq->private; |
1da177e4 | 2274 | void *rc = NULL; |
1da177e4 LT |
2275 | |
2276 | if (v == SEQ_START_TOKEN) { | |
2277 | rc = tcp_get_idx(seq, 0); | |
2278 | goto out; | |
2279 | } | |
1da177e4 LT |
2280 | |
2281 | switch (st->state) { | |
2282 | case TCP_SEQ_STATE_OPENREQ: | |
2283 | case TCP_SEQ_STATE_LISTENING: | |
2284 | rc = listening_get_next(seq, v); | |
2285 | if (!rc) { | |
1da177e4 | 2286 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
a8b690f9 TH |
2287 | st->bucket = 0; |
2288 | st->offset = 0; | |
1da177e4 LT |
2289 | rc = established_get_first(seq); |
2290 | } | |
2291 | break; | |
2292 | case TCP_SEQ_STATE_ESTABLISHED: | |
2293 | case TCP_SEQ_STATE_TIME_WAIT: | |
2294 | rc = established_get_next(seq, v); | |
2295 | break; | |
2296 | } | |
2297 | out: | |
2298 | ++*pos; | |
a8b690f9 | 2299 | st->last_pos = *pos; |
1da177e4 LT |
2300 | return rc; |
2301 | } | |
2302 | ||
2303 | static void tcp_seq_stop(struct seq_file *seq, void *v) | |
2304 | { | |
5799de0b | 2305 | struct tcp_iter_state *st = seq->private; |
1da177e4 LT |
2306 | |
2307 | switch (st->state) { | |
2308 | case TCP_SEQ_STATE_OPENREQ: | |
2309 | if (v) { | |
463c84b9 ACM |
2310 | struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk); |
2311 | read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); | |
1da177e4 LT |
2312 | } |
2313 | case TCP_SEQ_STATE_LISTENING: | |
2314 | if (v != SEQ_START_TOKEN) | |
5caea4ea | 2315 | spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock); |
1da177e4 LT |
2316 | break; |
2317 | case TCP_SEQ_STATE_TIME_WAIT: | |
2318 | case TCP_SEQ_STATE_ESTABLISHED: | |
2319 | if (v) | |
9db66bdc | 2320 | spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); |
1da177e4 LT |
2321 | break; |
2322 | } | |
2323 | } | |
2324 | ||
73cb88ec | 2325 | int tcp_seq_open(struct inode *inode, struct file *file) |
1da177e4 LT |
2326 | { |
2327 | struct tcp_seq_afinfo *afinfo = PDE(inode)->data; | |
1da177e4 | 2328 | struct tcp_iter_state *s; |
52d6f3f1 | 2329 | int err; |
1da177e4 | 2330 | |
52d6f3f1 DL |
2331 | err = seq_open_net(inode, file, &afinfo->seq_ops, |
2332 | sizeof(struct tcp_iter_state)); | |
2333 | if (err < 0) | |
2334 | return err; | |
f40c8174 | 2335 | |
52d6f3f1 | 2336 | s = ((struct seq_file *)file->private_data)->private; |
1da177e4 | 2337 | s->family = afinfo->family; |
a8b690f9 | 2338 | s->last_pos = 0; |
f40c8174 DL |
2339 | return 0; |
2340 | } | |
73cb88ec | 2341 | EXPORT_SYMBOL(tcp_seq_open); |
f40c8174 | 2342 | |
6f8b13bc | 2343 | int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo) |
1da177e4 LT |
2344 | { |
2345 | int rc = 0; | |
2346 | struct proc_dir_entry *p; | |
2347 | ||
9427c4b3 DL |
2348 | afinfo->seq_ops.start = tcp_seq_start; |
2349 | afinfo->seq_ops.next = tcp_seq_next; | |
2350 | afinfo->seq_ops.stop = tcp_seq_stop; | |
2351 | ||
84841c3c | 2352 | p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, |
73cb88ec | 2353 | afinfo->seq_fops, afinfo); |
84841c3c | 2354 | if (!p) |
1da177e4 LT |
2355 | rc = -ENOMEM; |
2356 | return rc; | |
2357 | } | |
4bc2f18b | 2358 | EXPORT_SYMBOL(tcp_proc_register); |
1da177e4 | 2359 | |
6f8b13bc | 2360 | void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo) |
1da177e4 | 2361 | { |
6f8b13bc | 2362 | proc_net_remove(net, afinfo->name); |
1da177e4 | 2363 | } |
4bc2f18b | 2364 | EXPORT_SYMBOL(tcp_proc_unregister); |
1da177e4 | 2365 | |
cf533ea5 | 2366 | static void get_openreq4(const struct sock *sk, const struct request_sock *req, |
5e659e4c | 2367 | struct seq_file *f, int i, int uid, int *len) |
1da177e4 | 2368 | { |
2e6599cb | 2369 | const struct inet_request_sock *ireq = inet_rsk(req); |
1da177e4 LT |
2370 | int ttd = req->expires - jiffies; |
2371 | ||
5e659e4c | 2372 | seq_printf(f, "%4d: %08X:%04X %08X:%04X" |
71338aa7 | 2373 | " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %pK%n", |
1da177e4 | 2374 | i, |
2e6599cb | 2375 | ireq->loc_addr, |
c720c7e8 | 2376 | ntohs(inet_sk(sk)->inet_sport), |
2e6599cb ACM |
2377 | ireq->rmt_addr, |
2378 | ntohs(ireq->rmt_port), | |
1da177e4 LT |
2379 | TCP_SYN_RECV, |
2380 | 0, 0, /* could print option size, but that is af dependent. */ | |
2381 | 1, /* timers active (only the expire timer) */ | |
2382 | jiffies_to_clock_t(ttd), | |
2383 | req->retrans, | |
2384 | uid, | |
2385 | 0, /* non standard timer */ | |
2386 | 0, /* open_requests have no inode */ | |
2387 | atomic_read(&sk->sk_refcnt), | |
5e659e4c PE |
2388 | req, |
2389 | len); | |
1da177e4 LT |
2390 | } |
2391 | ||
5e659e4c | 2392 | static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len) |
1da177e4 LT |
2393 | { |
2394 | int timer_active; | |
2395 | unsigned long timer_expires; | |
cf533ea5 | 2396 | const struct tcp_sock *tp = tcp_sk(sk); |
cf4c6bf8 | 2397 | const struct inet_connection_sock *icsk = inet_csk(sk); |
cf533ea5 | 2398 | const struct inet_sock *inet = inet_sk(sk); |
c720c7e8 ED |
2399 | __be32 dest = inet->inet_daddr; |
2400 | __be32 src = inet->inet_rcv_saddr; | |
2401 | __u16 destp = ntohs(inet->inet_dport); | |
2402 | __u16 srcp = ntohs(inet->inet_sport); | |
49d09007 | 2403 | int rx_queue; |
1da177e4 | 2404 | |
463c84b9 | 2405 | if (icsk->icsk_pending == ICSK_TIME_RETRANS) { |
1da177e4 | 2406 | timer_active = 1; |
463c84b9 ACM |
2407 | timer_expires = icsk->icsk_timeout; |
2408 | } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { | |
1da177e4 | 2409 | timer_active = 4; |
463c84b9 | 2410 | timer_expires = icsk->icsk_timeout; |
cf4c6bf8 | 2411 | } else if (timer_pending(&sk->sk_timer)) { |
1da177e4 | 2412 | timer_active = 2; |
cf4c6bf8 | 2413 | timer_expires = sk->sk_timer.expires; |
1da177e4 LT |
2414 | } else { |
2415 | timer_active = 0; | |
2416 | timer_expires = jiffies; | |
2417 | } | |
2418 | ||
49d09007 ED |
2419 | if (sk->sk_state == TCP_LISTEN) |
2420 | rx_queue = sk->sk_ack_backlog; | |
2421 | else | |
2422 | /* | |
2423 | * because we dont lock socket, we might find a transient negative value | |
2424 | */ | |
2425 | rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0); | |
2426 | ||
5e659e4c | 2427 | seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX " |
71338aa7 | 2428 | "%08X %5d %8d %lu %d %pK %lu %lu %u %u %d%n", |
cf4c6bf8 | 2429 | i, src, srcp, dest, destp, sk->sk_state, |
47da8ee6 | 2430 | tp->write_seq - tp->snd_una, |
49d09007 | 2431 | rx_queue, |
1da177e4 LT |
2432 | timer_active, |
2433 | jiffies_to_clock_t(timer_expires - jiffies), | |
463c84b9 | 2434 | icsk->icsk_retransmits, |
cf4c6bf8 | 2435 | sock_i_uid(sk), |
6687e988 | 2436 | icsk->icsk_probes_out, |
cf4c6bf8 IJ |
2437 | sock_i_ino(sk), |
2438 | atomic_read(&sk->sk_refcnt), sk, | |
7be87351 SH |
2439 | jiffies_to_clock_t(icsk->icsk_rto), |
2440 | jiffies_to_clock_t(icsk->icsk_ack.ato), | |
463c84b9 | 2441 | (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong, |
1da177e4 | 2442 | tp->snd_cwnd, |
0b6a05c1 | 2443 | tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh, |
5e659e4c | 2444 | len); |
1da177e4 LT |
2445 | } |
2446 | ||
cf533ea5 | 2447 | static void get_timewait4_sock(const struct inet_timewait_sock *tw, |
5e659e4c | 2448 | struct seq_file *f, int i, int *len) |
1da177e4 | 2449 | { |
23f33c2d | 2450 | __be32 dest, src; |
1da177e4 LT |
2451 | __u16 destp, srcp; |
2452 | int ttd = tw->tw_ttd - jiffies; | |
2453 | ||
2454 | if (ttd < 0) | |
2455 | ttd = 0; | |
2456 | ||
2457 | dest = tw->tw_daddr; | |
2458 | src = tw->tw_rcv_saddr; | |
2459 | destp = ntohs(tw->tw_dport); | |
2460 | srcp = ntohs(tw->tw_sport); | |
2461 | ||
5e659e4c | 2462 | seq_printf(f, "%4d: %08X:%04X %08X:%04X" |
71338aa7 | 2463 | " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK%n", |
1da177e4 LT |
2464 | i, src, srcp, dest, destp, tw->tw_substate, 0, 0, |
2465 | 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0, | |
5e659e4c | 2466 | atomic_read(&tw->tw_refcnt), tw, len); |
1da177e4 LT |
2467 | } |
2468 | ||
2469 | #define TMPSZ 150 | |
2470 | ||
2471 | static int tcp4_seq_show(struct seq_file *seq, void *v) | |
2472 | { | |
5799de0b | 2473 | struct tcp_iter_state *st; |
5e659e4c | 2474 | int len; |
1da177e4 LT |
2475 | |
2476 | if (v == SEQ_START_TOKEN) { | |
2477 | seq_printf(seq, "%-*s\n", TMPSZ - 1, | |
2478 | " sl local_address rem_address st tx_queue " | |
2479 | "rx_queue tr tm->when retrnsmt uid timeout " | |
2480 | "inode"); | |
2481 | goto out; | |
2482 | } | |
2483 | st = seq->private; | |
2484 | ||
2485 | switch (st->state) { | |
2486 | case TCP_SEQ_STATE_LISTENING: | |
2487 | case TCP_SEQ_STATE_ESTABLISHED: | |
5e659e4c | 2488 | get_tcp4_sock(v, seq, st->num, &len); |
1da177e4 LT |
2489 | break; |
2490 | case TCP_SEQ_STATE_OPENREQ: | |
5e659e4c | 2491 | get_openreq4(st->syn_wait_sk, v, seq, st->num, st->uid, &len); |
1da177e4 LT |
2492 | break; |
2493 | case TCP_SEQ_STATE_TIME_WAIT: | |
5e659e4c | 2494 | get_timewait4_sock(v, seq, st->num, &len); |
1da177e4 LT |
2495 | break; |
2496 | } | |
5e659e4c | 2497 | seq_printf(seq, "%*s\n", TMPSZ - 1 - len, ""); |
1da177e4 LT |
2498 | out: |
2499 | return 0; | |
2500 | } | |
2501 | ||
73cb88ec AV |
2502 | static const struct file_operations tcp_afinfo_seq_fops = { |
2503 | .owner = THIS_MODULE, | |
2504 | .open = tcp_seq_open, | |
2505 | .read = seq_read, | |
2506 | .llseek = seq_lseek, | |
2507 | .release = seq_release_net | |
2508 | }; | |
2509 | ||
1da177e4 | 2510 | static struct tcp_seq_afinfo tcp4_seq_afinfo = { |
1da177e4 LT |
2511 | .name = "tcp", |
2512 | .family = AF_INET, | |
73cb88ec | 2513 | .seq_fops = &tcp_afinfo_seq_fops, |
9427c4b3 DL |
2514 | .seq_ops = { |
2515 | .show = tcp4_seq_show, | |
2516 | }, | |
1da177e4 LT |
2517 | }; |
2518 | ||
2c8c1e72 | 2519 | static int __net_init tcp4_proc_init_net(struct net *net) |
757764f6 PE |
2520 | { |
2521 | return tcp_proc_register(net, &tcp4_seq_afinfo); | |
2522 | } | |
2523 | ||
2c8c1e72 | 2524 | static void __net_exit tcp4_proc_exit_net(struct net *net) |
757764f6 PE |
2525 | { |
2526 | tcp_proc_unregister(net, &tcp4_seq_afinfo); | |
2527 | } | |
2528 | ||
2529 | static struct pernet_operations tcp4_net_ops = { | |
2530 | .init = tcp4_proc_init_net, | |
2531 | .exit = tcp4_proc_exit_net, | |
2532 | }; | |
2533 | ||
1da177e4 LT |
2534 | int __init tcp4_proc_init(void) |
2535 | { | |
757764f6 | 2536 | return register_pernet_subsys(&tcp4_net_ops); |
1da177e4 LT |
2537 | } |
2538 | ||
2539 | void tcp4_proc_exit(void) | |
2540 | { | |
757764f6 | 2541 | unregister_pernet_subsys(&tcp4_net_ops); |
1da177e4 LT |
2542 | } |
2543 | #endif /* CONFIG_PROC_FS */ | |
2544 | ||
bf296b12 HX |
2545 | struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb) |
2546 | { | |
b71d1d42 | 2547 | const struct iphdr *iph = skb_gro_network_header(skb); |
bf296b12 HX |
2548 | |
2549 | switch (skb->ip_summed) { | |
2550 | case CHECKSUM_COMPLETE: | |
86911732 | 2551 | if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr, |
bf296b12 HX |
2552 | skb->csum)) { |
2553 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
2554 | break; | |
2555 | } | |
2556 | ||
2557 | /* fall through */ | |
2558 | case CHECKSUM_NONE: | |
2559 | NAPI_GRO_CB(skb)->flush = 1; | |
2560 | return NULL; | |
2561 | } | |
2562 | ||
2563 | return tcp_gro_receive(head, skb); | |
2564 | } | |
bf296b12 HX |
2565 | |
2566 | int tcp4_gro_complete(struct sk_buff *skb) | |
2567 | { | |
b71d1d42 | 2568 | const struct iphdr *iph = ip_hdr(skb); |
bf296b12 HX |
2569 | struct tcphdr *th = tcp_hdr(skb); |
2570 | ||
2571 | th->check = ~tcp_v4_check(skb->len - skb_transport_offset(skb), | |
2572 | iph->saddr, iph->daddr, 0); | |
2573 | skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; | |
2574 | ||
2575 | return tcp_gro_complete(skb); | |
2576 | } | |
bf296b12 | 2577 | |
1da177e4 LT |
2578 | struct proto tcp_prot = { |
2579 | .name = "TCP", | |
2580 | .owner = THIS_MODULE, | |
2581 | .close = tcp_close, | |
2582 | .connect = tcp_v4_connect, | |
2583 | .disconnect = tcp_disconnect, | |
463c84b9 | 2584 | .accept = inet_csk_accept, |
1da177e4 LT |
2585 | .ioctl = tcp_ioctl, |
2586 | .init = tcp_v4_init_sock, | |
2587 | .destroy = tcp_v4_destroy_sock, | |
2588 | .shutdown = tcp_shutdown, | |
2589 | .setsockopt = tcp_setsockopt, | |
2590 | .getsockopt = tcp_getsockopt, | |
1da177e4 | 2591 | .recvmsg = tcp_recvmsg, |
7ba42910 CG |
2592 | .sendmsg = tcp_sendmsg, |
2593 | .sendpage = tcp_sendpage, | |
1da177e4 | 2594 | .backlog_rcv = tcp_v4_do_rcv, |
46d3ceab | 2595 | .release_cb = tcp_release_cb, |
ab1e0a13 ACM |
2596 | .hash = inet_hash, |
2597 | .unhash = inet_unhash, | |
2598 | .get_port = inet_csk_get_port, | |
1da177e4 LT |
2599 | .enter_memory_pressure = tcp_enter_memory_pressure, |
2600 | .sockets_allocated = &tcp_sockets_allocated, | |
0a5578cf | 2601 | .orphan_count = &tcp_orphan_count, |
1da177e4 LT |
2602 | .memory_allocated = &tcp_memory_allocated, |
2603 | .memory_pressure = &tcp_memory_pressure, | |
1da177e4 LT |
2604 | .sysctl_wmem = sysctl_tcp_wmem, |
2605 | .sysctl_rmem = sysctl_tcp_rmem, | |
2606 | .max_header = MAX_TCP_HEADER, | |
2607 | .obj_size = sizeof(struct tcp_sock), | |
3ab5aee7 | 2608 | .slab_flags = SLAB_DESTROY_BY_RCU, |
6d6ee43e | 2609 | .twsk_prot = &tcp_timewait_sock_ops, |
60236fdd | 2610 | .rsk_prot = &tcp_request_sock_ops, |
39d8cda7 | 2611 | .h.hashinfo = &tcp_hashinfo, |
7ba42910 | 2612 | .no_autobind = true, |
543d9cfe ACM |
2613 | #ifdef CONFIG_COMPAT |
2614 | .compat_setsockopt = compat_tcp_setsockopt, | |
2615 | .compat_getsockopt = compat_tcp_getsockopt, | |
2616 | #endif | |
d1a4c0b3 GC |
2617 | #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM |
2618 | .init_cgroup = tcp_init_cgroup, | |
2619 | .destroy_cgroup = tcp_destroy_cgroup, | |
2620 | .proto_cgroup = tcp_proto_cgroup, | |
2621 | #endif | |
1da177e4 | 2622 | }; |
4bc2f18b | 2623 | EXPORT_SYMBOL(tcp_prot); |
1da177e4 | 2624 | |
046ee902 DL |
2625 | static int __net_init tcp_sk_init(struct net *net) |
2626 | { | |
2627 | return inet_ctl_sock_create(&net->ipv4.tcp_sock, | |
2628 | PF_INET, SOCK_RAW, IPPROTO_TCP, net); | |
2629 | } | |
2630 | ||
2631 | static void __net_exit tcp_sk_exit(struct net *net) | |
2632 | { | |
2633 | inet_ctl_sock_destroy(net->ipv4.tcp_sock); | |
b099ce26 EB |
2634 | } |
2635 | ||
2636 | static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list) | |
2637 | { | |
2638 | inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET); | |
046ee902 DL |
2639 | } |
2640 | ||
2641 | static struct pernet_operations __net_initdata tcp_sk_ops = { | |
b099ce26 EB |
2642 | .init = tcp_sk_init, |
2643 | .exit = tcp_sk_exit, | |
2644 | .exit_batch = tcp_sk_exit_batch, | |
046ee902 DL |
2645 | }; |
2646 | ||
9b0f976f | 2647 | void __init tcp_v4_init(void) |
1da177e4 | 2648 | { |
5caea4ea | 2649 | inet_hashinfo_init(&tcp_hashinfo); |
6a1b3054 | 2650 | if (register_pernet_subsys(&tcp_sk_ops)) |
1da177e4 | 2651 | panic("Failed to create the TCP control socket.\n"); |
1da177e4 | 2652 | } |