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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * Implementation of the Transmission Control Protocol(TCP). | |
7 | * | |
1da177e4 LT |
8 | * IPv4 specific functions |
9 | * | |
10 | * | |
11 | * code split from: | |
12 | * linux/ipv4/tcp.c | |
13 | * linux/ipv4/tcp_input.c | |
14 | * linux/ipv4/tcp_output.c | |
15 | * | |
16 | * See tcp.c for author information | |
17 | * | |
18 | * This program is free software; you can redistribute it and/or | |
19 | * modify it under the terms of the GNU General Public License | |
20 | * as published by the Free Software Foundation; either version | |
21 | * 2 of the License, or (at your option) any later version. | |
22 | */ | |
23 | ||
24 | /* | |
25 | * Changes: | |
26 | * David S. Miller : New socket lookup architecture. | |
27 | * This code is dedicated to John Dyson. | |
28 | * David S. Miller : Change semantics of established hash, | |
29 | * half is devoted to TIME_WAIT sockets | |
30 | * and the rest go in the other half. | |
31 | * Andi Kleen : Add support for syncookies and fixed | |
32 | * some bugs: ip options weren't passed to | |
33 | * the TCP layer, missed a check for an | |
34 | * ACK bit. | |
35 | * Andi Kleen : Implemented fast path mtu discovery. | |
36 | * Fixed many serious bugs in the | |
60236fdd | 37 | * request_sock handling and moved |
1da177e4 LT |
38 | * most of it into the af independent code. |
39 | * Added tail drop and some other bugfixes. | |
caa20d9a | 40 | * Added new listen semantics. |
1da177e4 LT |
41 | * Mike McLagan : Routing by source |
42 | * Juan Jose Ciarlante: ip_dynaddr bits | |
43 | * Andi Kleen: various fixes. | |
44 | * Vitaly E. Lavrov : Transparent proxy revived after year | |
45 | * coma. | |
46 | * Andi Kleen : Fix new listen. | |
47 | * Andi Kleen : Fix accept error reporting. | |
48 | * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which | |
49 | * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind | |
50 | * a single port at the same time. | |
51 | */ | |
52 | ||
1da177e4 | 53 | |
eb4dea58 | 54 | #include <linux/bottom_half.h> |
1da177e4 LT |
55 | #include <linux/types.h> |
56 | #include <linux/fcntl.h> | |
57 | #include <linux/module.h> | |
58 | #include <linux/random.h> | |
59 | #include <linux/cache.h> | |
60 | #include <linux/jhash.h> | |
61 | #include <linux/init.h> | |
62 | #include <linux/times.h> | |
5a0e3ad6 | 63 | #include <linux/slab.h> |
1da177e4 | 64 | |
457c4cbc | 65 | #include <net/net_namespace.h> |
1da177e4 | 66 | #include <net/icmp.h> |
304a1618 | 67 | #include <net/inet_hashtables.h> |
1da177e4 | 68 | #include <net/tcp.h> |
20380731 | 69 | #include <net/transp_v6.h> |
1da177e4 LT |
70 | #include <net/ipv6.h> |
71 | #include <net/inet_common.h> | |
6d6ee43e | 72 | #include <net/timewait_sock.h> |
1da177e4 | 73 | #include <net/xfrm.h> |
1a2449a8 | 74 | #include <net/netdma.h> |
1da177e4 LT |
75 | |
76 | #include <linux/inet.h> | |
77 | #include <linux/ipv6.h> | |
78 | #include <linux/stddef.h> | |
79 | #include <linux/proc_fs.h> | |
80 | #include <linux/seq_file.h> | |
81 | ||
cfb6eeb4 YH |
82 | #include <linux/crypto.h> |
83 | #include <linux/scatterlist.h> | |
84 | ||
ab32ea5d BH |
85 | int sysctl_tcp_tw_reuse __read_mostly; |
86 | int sysctl_tcp_low_latency __read_mostly; | |
4bc2f18b | 87 | EXPORT_SYMBOL(sysctl_tcp_low_latency); |
1da177e4 | 88 | |
1da177e4 | 89 | |
cfb6eeb4 | 90 | #ifdef CONFIG_TCP_MD5SIG |
7174259e ACM |
91 | static struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk, |
92 | __be32 addr); | |
49a72dfb AL |
93 | static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key, |
94 | __be32 daddr, __be32 saddr, struct tcphdr *th); | |
9501f972 YH |
95 | #else |
96 | static inline | |
97 | struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr) | |
98 | { | |
99 | return NULL; | |
100 | } | |
cfb6eeb4 YH |
101 | #endif |
102 | ||
5caea4ea | 103 | struct inet_hashinfo tcp_hashinfo; |
4bc2f18b | 104 | EXPORT_SYMBOL(tcp_hashinfo); |
1da177e4 | 105 | |
a94f723d | 106 | static inline __u32 tcp_v4_init_sequence(struct sk_buff *skb) |
1da177e4 | 107 | { |
eddc9ec5 ACM |
108 | return secure_tcp_sequence_number(ip_hdr(skb)->daddr, |
109 | ip_hdr(skb)->saddr, | |
aa8223c7 ACM |
110 | tcp_hdr(skb)->dest, |
111 | tcp_hdr(skb)->source); | |
1da177e4 LT |
112 | } |
113 | ||
6d6ee43e ACM |
114 | int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) |
115 | { | |
116 | const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw); | |
117 | struct tcp_sock *tp = tcp_sk(sk); | |
118 | ||
119 | /* With PAWS, it is safe from the viewpoint | |
120 | of data integrity. Even without PAWS it is safe provided sequence | |
121 | spaces do not overlap i.e. at data rates <= 80Mbit/sec. | |
122 | ||
123 | Actually, the idea is close to VJ's one, only timestamp cache is | |
124 | held not per host, but per port pair and TW bucket is used as state | |
125 | holder. | |
126 | ||
127 | If TW bucket has been already destroyed we fall back to VJ's scheme | |
128 | and use initial timestamp retrieved from peer table. | |
129 | */ | |
130 | if (tcptw->tw_ts_recent_stamp && | |
131 | (twp == NULL || (sysctl_tcp_tw_reuse && | |
9d729f72 | 132 | get_seconds() - tcptw->tw_ts_recent_stamp > 1))) { |
6d6ee43e ACM |
133 | tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2; |
134 | if (tp->write_seq == 0) | |
135 | tp->write_seq = 1; | |
136 | tp->rx_opt.ts_recent = tcptw->tw_ts_recent; | |
137 | tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; | |
138 | sock_hold(sktw); | |
139 | return 1; | |
140 | } | |
141 | ||
142 | return 0; | |
143 | } | |
6d6ee43e ACM |
144 | EXPORT_SYMBOL_GPL(tcp_twsk_unique); |
145 | ||
1da177e4 LT |
146 | /* This will initiate an outgoing connection. */ |
147 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) | |
148 | { | |
2d7192d6 | 149 | struct sockaddr_in *usin = (struct sockaddr_in *)uaddr; |
1da177e4 LT |
150 | struct inet_sock *inet = inet_sk(sk); |
151 | struct tcp_sock *tp = tcp_sk(sk); | |
dca8b089 | 152 | __be16 orig_sport, orig_dport; |
bada8adc | 153 | __be32 daddr, nexthop; |
da905bd1 | 154 | struct flowi4 *fl4; |
2d7192d6 | 155 | struct rtable *rt; |
1da177e4 | 156 | int err; |
f6d8bd05 | 157 | struct ip_options_rcu *inet_opt; |
1da177e4 LT |
158 | |
159 | if (addr_len < sizeof(struct sockaddr_in)) | |
160 | return -EINVAL; | |
161 | ||
162 | if (usin->sin_family != AF_INET) | |
163 | return -EAFNOSUPPORT; | |
164 | ||
165 | nexthop = daddr = usin->sin_addr.s_addr; | |
f6d8bd05 ED |
166 | inet_opt = rcu_dereference_protected(inet->inet_opt, |
167 | sock_owned_by_user(sk)); | |
168 | if (inet_opt && inet_opt->opt.srr) { | |
1da177e4 LT |
169 | if (!daddr) |
170 | return -EINVAL; | |
f6d8bd05 | 171 | nexthop = inet_opt->opt.faddr; |
1da177e4 LT |
172 | } |
173 | ||
dca8b089 DM |
174 | orig_sport = inet->inet_sport; |
175 | orig_dport = usin->sin_port; | |
da905bd1 DM |
176 | fl4 = &inet->cork.fl.u.ip4; |
177 | rt = ip_route_connect(fl4, nexthop, inet->inet_saddr, | |
b23dd4fe DM |
178 | RT_CONN_FLAGS(sk), sk->sk_bound_dev_if, |
179 | IPPROTO_TCP, | |
180 | orig_sport, orig_dport, sk, true); | |
181 | if (IS_ERR(rt)) { | |
182 | err = PTR_ERR(rt); | |
183 | if (err == -ENETUNREACH) | |
7c73a6fa | 184 | IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
b23dd4fe | 185 | return err; |
584bdf8c | 186 | } |
1da177e4 LT |
187 | |
188 | if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { | |
189 | ip_rt_put(rt); | |
190 | return -ENETUNREACH; | |
191 | } | |
192 | ||
f6d8bd05 | 193 | if (!inet_opt || !inet_opt->opt.srr) |
da905bd1 | 194 | daddr = fl4->daddr; |
1da177e4 | 195 | |
c720c7e8 | 196 | if (!inet->inet_saddr) |
da905bd1 | 197 | inet->inet_saddr = fl4->saddr; |
c720c7e8 | 198 | inet->inet_rcv_saddr = inet->inet_saddr; |
1da177e4 | 199 | |
c720c7e8 | 200 | if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) { |
1da177e4 LT |
201 | /* Reset inherited state */ |
202 | tp->rx_opt.ts_recent = 0; | |
203 | tp->rx_opt.ts_recent_stamp = 0; | |
204 | tp->write_seq = 0; | |
205 | } | |
206 | ||
295ff7ed | 207 | if (tcp_death_row.sysctl_tw_recycle && |
da905bd1 | 208 | !tp->rx_opt.ts_recent_stamp && fl4->daddr == daddr) { |
1da177e4 | 209 | struct inet_peer *peer = rt_get_peer(rt); |
7174259e ACM |
210 | /* |
211 | * VJ's idea. We save last timestamp seen from | |
212 | * the destination in peer table, when entering state | |
213 | * TIME-WAIT * and initialize rx_opt.ts_recent from it, | |
214 | * when trying new connection. | |
1da177e4 | 215 | */ |
317fe0e6 ED |
216 | if (peer) { |
217 | inet_peer_refcheck(peer); | |
218 | if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) { | |
219 | tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp; | |
220 | tp->rx_opt.ts_recent = peer->tcp_ts; | |
221 | } | |
1da177e4 LT |
222 | } |
223 | } | |
224 | ||
c720c7e8 ED |
225 | inet->inet_dport = usin->sin_port; |
226 | inet->inet_daddr = daddr; | |
1da177e4 | 227 | |
d83d8461 | 228 | inet_csk(sk)->icsk_ext_hdr_len = 0; |
f6d8bd05 ED |
229 | if (inet_opt) |
230 | inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen; | |
1da177e4 | 231 | |
bee7ca9e | 232 | tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT; |
1da177e4 LT |
233 | |
234 | /* Socket identity is still unknown (sport may be zero). | |
235 | * However we set state to SYN-SENT and not releasing socket | |
236 | * lock select source port, enter ourselves into the hash tables and | |
237 | * complete initialization after this. | |
238 | */ | |
239 | tcp_set_state(sk, TCP_SYN_SENT); | |
a7f5e7f1 | 240 | err = inet_hash_connect(&tcp_death_row, sk); |
1da177e4 LT |
241 | if (err) |
242 | goto failure; | |
243 | ||
da905bd1 | 244 | rt = ip_route_newports(fl4, rt, orig_sport, orig_dport, |
b23dd4fe DM |
245 | inet->inet_sport, inet->inet_dport, sk); |
246 | if (IS_ERR(rt)) { | |
247 | err = PTR_ERR(rt); | |
248 | rt = NULL; | |
1da177e4 | 249 | goto failure; |
b23dd4fe | 250 | } |
1da177e4 | 251 | /* OK, now commit destination to socket. */ |
bcd76111 | 252 | sk->sk_gso_type = SKB_GSO_TCPV4; |
d8d1f30b | 253 | sk_setup_caps(sk, &rt->dst); |
1da177e4 LT |
254 | |
255 | if (!tp->write_seq) | |
c720c7e8 ED |
256 | tp->write_seq = secure_tcp_sequence_number(inet->inet_saddr, |
257 | inet->inet_daddr, | |
258 | inet->inet_sport, | |
1da177e4 LT |
259 | usin->sin_port); |
260 | ||
c720c7e8 | 261 | inet->inet_id = tp->write_seq ^ jiffies; |
1da177e4 LT |
262 | |
263 | err = tcp_connect(sk); | |
264 | rt = NULL; | |
265 | if (err) | |
266 | goto failure; | |
267 | ||
268 | return 0; | |
269 | ||
270 | failure: | |
7174259e ACM |
271 | /* |
272 | * This unhashes the socket and releases the local port, | |
273 | * if necessary. | |
274 | */ | |
1da177e4 LT |
275 | tcp_set_state(sk, TCP_CLOSE); |
276 | ip_rt_put(rt); | |
277 | sk->sk_route_caps = 0; | |
c720c7e8 | 278 | inet->inet_dport = 0; |
1da177e4 LT |
279 | return err; |
280 | } | |
4bc2f18b | 281 | EXPORT_SYMBOL(tcp_v4_connect); |
1da177e4 | 282 | |
1da177e4 LT |
283 | /* |
284 | * This routine does path mtu discovery as defined in RFC1191. | |
285 | */ | |
b71d1d42 | 286 | static void do_pmtu_discovery(struct sock *sk, const struct iphdr *iph, u32 mtu) |
1da177e4 LT |
287 | { |
288 | struct dst_entry *dst; | |
289 | struct inet_sock *inet = inet_sk(sk); | |
1da177e4 LT |
290 | |
291 | /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs | |
292 | * send out by Linux are always <576bytes so they should go through | |
293 | * unfragmented). | |
294 | */ | |
295 | if (sk->sk_state == TCP_LISTEN) | |
296 | return; | |
297 | ||
298 | /* We don't check in the destentry if pmtu discovery is forbidden | |
299 | * on this route. We just assume that no packet_to_big packets | |
300 | * are send back when pmtu discovery is not active. | |
e905a9ed | 301 | * There is a small race when the user changes this flag in the |
1da177e4 LT |
302 | * route, but I think that's acceptable. |
303 | */ | |
304 | if ((dst = __sk_dst_check(sk, 0)) == NULL) | |
305 | return; | |
306 | ||
307 | dst->ops->update_pmtu(dst, mtu); | |
308 | ||
309 | /* Something is about to be wrong... Remember soft error | |
310 | * for the case, if this connection will not able to recover. | |
311 | */ | |
312 | if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst)) | |
313 | sk->sk_err_soft = EMSGSIZE; | |
314 | ||
315 | mtu = dst_mtu(dst); | |
316 | ||
317 | if (inet->pmtudisc != IP_PMTUDISC_DONT && | |
d83d8461 | 318 | inet_csk(sk)->icsk_pmtu_cookie > mtu) { |
1da177e4 LT |
319 | tcp_sync_mss(sk, mtu); |
320 | ||
321 | /* Resend the TCP packet because it's | |
322 | * clear that the old packet has been | |
323 | * dropped. This is the new "fast" path mtu | |
324 | * discovery. | |
325 | */ | |
326 | tcp_simple_retransmit(sk); | |
327 | } /* else let the usual retransmit timer handle it */ | |
328 | } | |
329 | ||
330 | /* | |
331 | * This routine is called by the ICMP module when it gets some | |
332 | * sort of error condition. If err < 0 then the socket should | |
333 | * be closed and the error returned to the user. If err > 0 | |
334 | * it's just the icmp type << 8 | icmp code. After adjustment | |
335 | * header points to the first 8 bytes of the tcp header. We need | |
336 | * to find the appropriate port. | |
337 | * | |
338 | * The locking strategy used here is very "optimistic". When | |
339 | * someone else accesses the socket the ICMP is just dropped | |
340 | * and for some paths there is no check at all. | |
341 | * A more general error queue to queue errors for later handling | |
342 | * is probably better. | |
343 | * | |
344 | */ | |
345 | ||
4d1a2d9e | 346 | void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) |
1da177e4 | 347 | { |
b71d1d42 | 348 | const struct iphdr *iph = (const struct iphdr *)icmp_skb->data; |
4d1a2d9e | 349 | struct tcphdr *th = (struct tcphdr *)(icmp_skb->data + (iph->ihl << 2)); |
f1ecd5d9 | 350 | struct inet_connection_sock *icsk; |
1da177e4 LT |
351 | struct tcp_sock *tp; |
352 | struct inet_sock *inet; | |
4d1a2d9e DL |
353 | const int type = icmp_hdr(icmp_skb)->type; |
354 | const int code = icmp_hdr(icmp_skb)->code; | |
1da177e4 | 355 | struct sock *sk; |
f1ecd5d9 | 356 | struct sk_buff *skb; |
1da177e4 | 357 | __u32 seq; |
f1ecd5d9 | 358 | __u32 remaining; |
1da177e4 | 359 | int err; |
4d1a2d9e | 360 | struct net *net = dev_net(icmp_skb->dev); |
1da177e4 | 361 | |
4d1a2d9e | 362 | if (icmp_skb->len < (iph->ihl << 2) + 8) { |
dcfc23ca | 363 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
364 | return; |
365 | } | |
366 | ||
fd54d716 | 367 | sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest, |
4d1a2d9e | 368 | iph->saddr, th->source, inet_iif(icmp_skb)); |
1da177e4 | 369 | if (!sk) { |
dcfc23ca | 370 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
371 | return; |
372 | } | |
373 | if (sk->sk_state == TCP_TIME_WAIT) { | |
9469c7b4 | 374 | inet_twsk_put(inet_twsk(sk)); |
1da177e4 LT |
375 | return; |
376 | } | |
377 | ||
378 | bh_lock_sock(sk); | |
379 | /* If too many ICMPs get dropped on busy | |
380 | * servers this needs to be solved differently. | |
381 | */ | |
382 | if (sock_owned_by_user(sk)) | |
de0744af | 383 | NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); |
1da177e4 LT |
384 | |
385 | if (sk->sk_state == TCP_CLOSE) | |
386 | goto out; | |
387 | ||
97e3ecd1 | 388 | if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { |
389 | NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP); | |
390 | goto out; | |
391 | } | |
392 | ||
f1ecd5d9 | 393 | icsk = inet_csk(sk); |
1da177e4 LT |
394 | tp = tcp_sk(sk); |
395 | seq = ntohl(th->seq); | |
396 | if (sk->sk_state != TCP_LISTEN && | |
397 | !between(seq, tp->snd_una, tp->snd_nxt)) { | |
de0744af | 398 | NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); |
1da177e4 LT |
399 | goto out; |
400 | } | |
401 | ||
402 | switch (type) { | |
403 | case ICMP_SOURCE_QUENCH: | |
404 | /* Just silently ignore these. */ | |
405 | goto out; | |
406 | case ICMP_PARAMETERPROB: | |
407 | err = EPROTO; | |
408 | break; | |
409 | case ICMP_DEST_UNREACH: | |
410 | if (code > NR_ICMP_UNREACH) | |
411 | goto out; | |
412 | ||
413 | if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ | |
414 | if (!sock_owned_by_user(sk)) | |
415 | do_pmtu_discovery(sk, iph, info); | |
416 | goto out; | |
417 | } | |
418 | ||
419 | err = icmp_err_convert[code].errno; | |
f1ecd5d9 DL |
420 | /* check if icmp_skb allows revert of backoff |
421 | * (see draft-zimmermann-tcp-lcd) */ | |
422 | if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH) | |
423 | break; | |
424 | if (seq != tp->snd_una || !icsk->icsk_retransmits || | |
425 | !icsk->icsk_backoff) | |
426 | break; | |
427 | ||
8f49c270 DM |
428 | if (sock_owned_by_user(sk)) |
429 | break; | |
430 | ||
f1ecd5d9 DL |
431 | icsk->icsk_backoff--; |
432 | inet_csk(sk)->icsk_rto = __tcp_set_rto(tp) << | |
433 | icsk->icsk_backoff; | |
434 | tcp_bound_rto(sk); | |
435 | ||
436 | skb = tcp_write_queue_head(sk); | |
437 | BUG_ON(!skb); | |
438 | ||
439 | remaining = icsk->icsk_rto - min(icsk->icsk_rto, | |
440 | tcp_time_stamp - TCP_SKB_CB(skb)->when); | |
441 | ||
442 | if (remaining) { | |
443 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, | |
444 | remaining, TCP_RTO_MAX); | |
f1ecd5d9 DL |
445 | } else { |
446 | /* RTO revert clocked out retransmission. | |
447 | * Will retransmit now */ | |
448 | tcp_retransmit_timer(sk); | |
449 | } | |
450 | ||
1da177e4 LT |
451 | break; |
452 | case ICMP_TIME_EXCEEDED: | |
453 | err = EHOSTUNREACH; | |
454 | break; | |
455 | default: | |
456 | goto out; | |
457 | } | |
458 | ||
459 | switch (sk->sk_state) { | |
60236fdd | 460 | struct request_sock *req, **prev; |
1da177e4 LT |
461 | case TCP_LISTEN: |
462 | if (sock_owned_by_user(sk)) | |
463 | goto out; | |
464 | ||
463c84b9 ACM |
465 | req = inet_csk_search_req(sk, &prev, th->dest, |
466 | iph->daddr, iph->saddr); | |
1da177e4 LT |
467 | if (!req) |
468 | goto out; | |
469 | ||
470 | /* ICMPs are not backlogged, hence we cannot get | |
471 | an established socket here. | |
472 | */ | |
547b792c | 473 | WARN_ON(req->sk); |
1da177e4 | 474 | |
2e6599cb | 475 | if (seq != tcp_rsk(req)->snt_isn) { |
de0744af | 476 | NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); |
1da177e4 LT |
477 | goto out; |
478 | } | |
479 | ||
480 | /* | |
481 | * Still in SYN_RECV, just remove it silently. | |
482 | * There is no good way to pass the error to the newly | |
483 | * created socket, and POSIX does not want network | |
484 | * errors returned from accept(). | |
485 | */ | |
463c84b9 | 486 | inet_csk_reqsk_queue_drop(sk, req, prev); |
1da177e4 LT |
487 | goto out; |
488 | ||
489 | case TCP_SYN_SENT: | |
490 | case TCP_SYN_RECV: /* Cannot happen. | |
491 | It can f.e. if SYNs crossed. | |
492 | */ | |
493 | if (!sock_owned_by_user(sk)) { | |
1da177e4 LT |
494 | sk->sk_err = err; |
495 | ||
496 | sk->sk_error_report(sk); | |
497 | ||
498 | tcp_done(sk); | |
499 | } else { | |
500 | sk->sk_err_soft = err; | |
501 | } | |
502 | goto out; | |
503 | } | |
504 | ||
505 | /* If we've already connected we will keep trying | |
506 | * until we time out, or the user gives up. | |
507 | * | |
508 | * rfc1122 4.2.3.9 allows to consider as hard errors | |
509 | * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, | |
510 | * but it is obsoleted by pmtu discovery). | |
511 | * | |
512 | * Note, that in modern internet, where routing is unreliable | |
513 | * and in each dark corner broken firewalls sit, sending random | |
514 | * errors ordered by their masters even this two messages finally lose | |
515 | * their original sense (even Linux sends invalid PORT_UNREACHs) | |
516 | * | |
517 | * Now we are in compliance with RFCs. | |
518 | * --ANK (980905) | |
519 | */ | |
520 | ||
521 | inet = inet_sk(sk); | |
522 | if (!sock_owned_by_user(sk) && inet->recverr) { | |
523 | sk->sk_err = err; | |
524 | sk->sk_error_report(sk); | |
525 | } else { /* Only an error on timeout */ | |
526 | sk->sk_err_soft = err; | |
527 | } | |
528 | ||
529 | out: | |
530 | bh_unlock_sock(sk); | |
531 | sock_put(sk); | |
532 | } | |
533 | ||
419f9f89 HX |
534 | static void __tcp_v4_send_check(struct sk_buff *skb, |
535 | __be32 saddr, __be32 daddr) | |
1da177e4 | 536 | { |
aa8223c7 | 537 | struct tcphdr *th = tcp_hdr(skb); |
1da177e4 | 538 | |
84fa7933 | 539 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
419f9f89 | 540 | th->check = ~tcp_v4_check(skb->len, saddr, daddr, 0); |
663ead3b | 541 | skb->csum_start = skb_transport_header(skb) - skb->head; |
ff1dcadb | 542 | skb->csum_offset = offsetof(struct tcphdr, check); |
1da177e4 | 543 | } else { |
419f9f89 | 544 | th->check = tcp_v4_check(skb->len, saddr, daddr, |
07f0757a | 545 | csum_partial(th, |
1da177e4 LT |
546 | th->doff << 2, |
547 | skb->csum)); | |
548 | } | |
549 | } | |
550 | ||
419f9f89 | 551 | /* This routine computes an IPv4 TCP checksum. */ |
bb296246 | 552 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb) |
419f9f89 HX |
553 | { |
554 | struct inet_sock *inet = inet_sk(sk); | |
555 | ||
556 | __tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr); | |
557 | } | |
4bc2f18b | 558 | EXPORT_SYMBOL(tcp_v4_send_check); |
419f9f89 | 559 | |
a430a43d HX |
560 | int tcp_v4_gso_send_check(struct sk_buff *skb) |
561 | { | |
eddc9ec5 | 562 | const struct iphdr *iph; |
a430a43d HX |
563 | struct tcphdr *th; |
564 | ||
565 | if (!pskb_may_pull(skb, sizeof(*th))) | |
566 | return -EINVAL; | |
567 | ||
eddc9ec5 | 568 | iph = ip_hdr(skb); |
aa8223c7 | 569 | th = tcp_hdr(skb); |
a430a43d HX |
570 | |
571 | th->check = 0; | |
84fa7933 | 572 | skb->ip_summed = CHECKSUM_PARTIAL; |
419f9f89 | 573 | __tcp_v4_send_check(skb, iph->saddr, iph->daddr); |
a430a43d HX |
574 | return 0; |
575 | } | |
576 | ||
1da177e4 LT |
577 | /* |
578 | * This routine will send an RST to the other tcp. | |
579 | * | |
580 | * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.) | |
581 | * for reset. | |
582 | * Answer: if a packet caused RST, it is not for a socket | |
583 | * existing in our system, if it is matched to a socket, | |
584 | * it is just duplicate segment or bug in other side's TCP. | |
585 | * So that we build reply only basing on parameters | |
586 | * arrived with segment. | |
587 | * Exception: precedence violation. We do not implement it in any case. | |
588 | */ | |
589 | ||
cfb6eeb4 | 590 | static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 591 | { |
aa8223c7 | 592 | struct tcphdr *th = tcp_hdr(skb); |
cfb6eeb4 YH |
593 | struct { |
594 | struct tcphdr th; | |
595 | #ifdef CONFIG_TCP_MD5SIG | |
714e85be | 596 | __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)]; |
cfb6eeb4 YH |
597 | #endif |
598 | } rep; | |
1da177e4 | 599 | struct ip_reply_arg arg; |
cfb6eeb4 YH |
600 | #ifdef CONFIG_TCP_MD5SIG |
601 | struct tcp_md5sig_key *key; | |
602 | #endif | |
a86b1e30 | 603 | struct net *net; |
1da177e4 LT |
604 | |
605 | /* Never send a reset in response to a reset. */ | |
606 | if (th->rst) | |
607 | return; | |
608 | ||
511c3f92 | 609 | if (skb_rtable(skb)->rt_type != RTN_LOCAL) |
1da177e4 LT |
610 | return; |
611 | ||
612 | /* Swap the send and the receive. */ | |
cfb6eeb4 YH |
613 | memset(&rep, 0, sizeof(rep)); |
614 | rep.th.dest = th->source; | |
615 | rep.th.source = th->dest; | |
616 | rep.th.doff = sizeof(struct tcphdr) / 4; | |
617 | rep.th.rst = 1; | |
1da177e4 LT |
618 | |
619 | if (th->ack) { | |
cfb6eeb4 | 620 | rep.th.seq = th->ack_seq; |
1da177e4 | 621 | } else { |
cfb6eeb4 YH |
622 | rep.th.ack = 1; |
623 | rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin + | |
624 | skb->len - (th->doff << 2)); | |
1da177e4 LT |
625 | } |
626 | ||
7174259e | 627 | memset(&arg, 0, sizeof(arg)); |
cfb6eeb4 YH |
628 | arg.iov[0].iov_base = (unsigned char *)&rep; |
629 | arg.iov[0].iov_len = sizeof(rep.th); | |
630 | ||
631 | #ifdef CONFIG_TCP_MD5SIG | |
eddc9ec5 | 632 | key = sk ? tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr) : NULL; |
cfb6eeb4 YH |
633 | if (key) { |
634 | rep.opt[0] = htonl((TCPOPT_NOP << 24) | | |
635 | (TCPOPT_NOP << 16) | | |
636 | (TCPOPT_MD5SIG << 8) | | |
637 | TCPOLEN_MD5SIG); | |
638 | /* Update length and the length the header thinks exists */ | |
639 | arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; | |
640 | rep.th.doff = arg.iov[0].iov_len / 4; | |
641 | ||
49a72dfb | 642 | tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1], |
78e645cb IJ |
643 | key, ip_hdr(skb)->saddr, |
644 | ip_hdr(skb)->daddr, &rep.th); | |
cfb6eeb4 YH |
645 | } |
646 | #endif | |
eddc9ec5 ACM |
647 | arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, |
648 | ip_hdr(skb)->saddr, /* XXX */ | |
52cd5750 | 649 | arg.iov[0].iov_len, IPPROTO_TCP, 0); |
1da177e4 | 650 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; |
88ef4a5a | 651 | arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0; |
1da177e4 | 652 | |
adf30907 | 653 | net = dev_net(skb_dst(skb)->dev); |
0a5ebb80 | 654 | ip_send_reply(net->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr, |
7feb49c8 | 655 | &arg, arg.iov[0].iov_len); |
1da177e4 | 656 | |
63231bdd PE |
657 | TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS); |
658 | TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS); | |
1da177e4 LT |
659 | } |
660 | ||
661 | /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states | |
662 | outside socket context is ugly, certainly. What can I do? | |
663 | */ | |
664 | ||
9501f972 YH |
665 | static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack, |
666 | u32 win, u32 ts, int oif, | |
88ef4a5a KK |
667 | struct tcp_md5sig_key *key, |
668 | int reply_flags) | |
1da177e4 | 669 | { |
aa8223c7 | 670 | struct tcphdr *th = tcp_hdr(skb); |
1da177e4 LT |
671 | struct { |
672 | struct tcphdr th; | |
714e85be | 673 | __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2) |
cfb6eeb4 | 674 | #ifdef CONFIG_TCP_MD5SIG |
714e85be | 675 | + (TCPOLEN_MD5SIG_ALIGNED >> 2) |
cfb6eeb4 YH |
676 | #endif |
677 | ]; | |
1da177e4 LT |
678 | } rep; |
679 | struct ip_reply_arg arg; | |
adf30907 | 680 | struct net *net = dev_net(skb_dst(skb)->dev); |
1da177e4 LT |
681 | |
682 | memset(&rep.th, 0, sizeof(struct tcphdr)); | |
7174259e | 683 | memset(&arg, 0, sizeof(arg)); |
1da177e4 LT |
684 | |
685 | arg.iov[0].iov_base = (unsigned char *)&rep; | |
686 | arg.iov[0].iov_len = sizeof(rep.th); | |
687 | if (ts) { | |
cfb6eeb4 YH |
688 | rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
689 | (TCPOPT_TIMESTAMP << 8) | | |
690 | TCPOLEN_TIMESTAMP); | |
691 | rep.opt[1] = htonl(tcp_time_stamp); | |
692 | rep.opt[2] = htonl(ts); | |
cb48cfe8 | 693 | arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED; |
1da177e4 LT |
694 | } |
695 | ||
696 | /* Swap the send and the receive. */ | |
697 | rep.th.dest = th->source; | |
698 | rep.th.source = th->dest; | |
699 | rep.th.doff = arg.iov[0].iov_len / 4; | |
700 | rep.th.seq = htonl(seq); | |
701 | rep.th.ack_seq = htonl(ack); | |
702 | rep.th.ack = 1; | |
703 | rep.th.window = htons(win); | |
704 | ||
cfb6eeb4 | 705 | #ifdef CONFIG_TCP_MD5SIG |
cfb6eeb4 YH |
706 | if (key) { |
707 | int offset = (ts) ? 3 : 0; | |
708 | ||
709 | rep.opt[offset++] = htonl((TCPOPT_NOP << 24) | | |
710 | (TCPOPT_NOP << 16) | | |
711 | (TCPOPT_MD5SIG << 8) | | |
712 | TCPOLEN_MD5SIG); | |
713 | arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; | |
714 | rep.th.doff = arg.iov[0].iov_len/4; | |
715 | ||
49a72dfb | 716 | tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset], |
90b7e112 AL |
717 | key, ip_hdr(skb)->saddr, |
718 | ip_hdr(skb)->daddr, &rep.th); | |
cfb6eeb4 YH |
719 | } |
720 | #endif | |
88ef4a5a | 721 | arg.flags = reply_flags; |
eddc9ec5 ACM |
722 | arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, |
723 | ip_hdr(skb)->saddr, /* XXX */ | |
1da177e4 LT |
724 | arg.iov[0].iov_len, IPPROTO_TCP, 0); |
725 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; | |
9501f972 YH |
726 | if (oif) |
727 | arg.bound_dev_if = oif; | |
1da177e4 | 728 | |
0a5ebb80 | 729 | ip_send_reply(net->ipv4.tcp_sock, skb, ip_hdr(skb)->saddr, |
7feb49c8 | 730 | &arg, arg.iov[0].iov_len); |
1da177e4 | 731 | |
63231bdd | 732 | TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS); |
1da177e4 LT |
733 | } |
734 | ||
735 | static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) | |
736 | { | |
8feaf0c0 | 737 | struct inet_timewait_sock *tw = inet_twsk(sk); |
cfb6eeb4 | 738 | struct tcp_timewait_sock *tcptw = tcp_twsk(sk); |
1da177e4 | 739 | |
9501f972 | 740 | tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, |
7174259e | 741 | tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, |
9501f972 YH |
742 | tcptw->tw_ts_recent, |
743 | tw->tw_bound_dev_if, | |
88ef4a5a KK |
744 | tcp_twsk_md5_key(tcptw), |
745 | tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0 | |
9501f972 | 746 | ); |
1da177e4 | 747 | |
8feaf0c0 | 748 | inet_twsk_put(tw); |
1da177e4 LT |
749 | } |
750 | ||
6edafaaf | 751 | static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, |
7174259e | 752 | struct request_sock *req) |
1da177e4 | 753 | { |
9501f972 | 754 | tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1, |
cfb6eeb4 | 755 | tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, |
9501f972 YH |
756 | req->ts_recent, |
757 | 0, | |
88ef4a5a KK |
758 | tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr), |
759 | inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0); | |
1da177e4 LT |
760 | } |
761 | ||
1da177e4 | 762 | /* |
9bf1d83e | 763 | * Send a SYN-ACK after having received a SYN. |
60236fdd | 764 | * This still operates on a request_sock only, not on a big |
1da177e4 LT |
765 | * socket. |
766 | */ | |
72659ecc OP |
767 | static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst, |
768 | struct request_sock *req, | |
769 | struct request_values *rvp) | |
1da177e4 | 770 | { |
2e6599cb | 771 | const struct inet_request_sock *ireq = inet_rsk(req); |
6bd023f3 | 772 | struct flowi4 fl4; |
1da177e4 LT |
773 | int err = -1; |
774 | struct sk_buff * skb; | |
775 | ||
776 | /* First, grab a route. */ | |
6bd023f3 | 777 | if (!dst && (dst = inet_csk_route_req(sk, &fl4, req)) == NULL) |
fd80eb94 | 778 | return -1; |
1da177e4 | 779 | |
e6b4d113 | 780 | skb = tcp_make_synack(sk, dst, req, rvp); |
1da177e4 LT |
781 | |
782 | if (skb) { | |
419f9f89 | 783 | __tcp_v4_send_check(skb, ireq->loc_addr, ireq->rmt_addr); |
1da177e4 | 784 | |
2e6599cb ACM |
785 | err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr, |
786 | ireq->rmt_addr, | |
787 | ireq->opt); | |
b9df3cb8 | 788 | err = net_xmit_eval(err); |
1da177e4 LT |
789 | } |
790 | ||
1da177e4 LT |
791 | dst_release(dst); |
792 | return err; | |
793 | } | |
794 | ||
72659ecc | 795 | static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req, |
e6b4d113 | 796 | struct request_values *rvp) |
fd80eb94 | 797 | { |
72659ecc OP |
798 | TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); |
799 | return tcp_v4_send_synack(sk, NULL, req, rvp); | |
fd80eb94 DL |
800 | } |
801 | ||
1da177e4 | 802 | /* |
60236fdd | 803 | * IPv4 request_sock destructor. |
1da177e4 | 804 | */ |
60236fdd | 805 | static void tcp_v4_reqsk_destructor(struct request_sock *req) |
1da177e4 | 806 | { |
a51482bd | 807 | kfree(inet_rsk(req)->opt); |
1da177e4 LT |
808 | } |
809 | ||
2a1d4bd4 | 810 | static void syn_flood_warning(const struct sk_buff *skb) |
1da177e4 | 811 | { |
2a1d4bd4 | 812 | const char *msg; |
1da177e4 | 813 | |
2a1d4bd4 FW |
814 | #ifdef CONFIG_SYN_COOKIES |
815 | if (sysctl_tcp_syncookies) | |
816 | msg = "Sending cookies"; | |
817 | else | |
80e40daa | 818 | #endif |
2a1d4bd4 FW |
819 | msg = "Dropping request"; |
820 | ||
821 | pr_info("TCP: Possible SYN flooding on port %d. %s.\n", | |
822 | ntohs(tcp_hdr(skb)->dest), msg); | |
823 | } | |
1da177e4 LT |
824 | |
825 | /* | |
60236fdd | 826 | * Save and compile IPv4 options into the request_sock if needed. |
1da177e4 | 827 | */ |
f6d8bd05 ED |
828 | static struct ip_options_rcu *tcp_v4_save_options(struct sock *sk, |
829 | struct sk_buff *skb) | |
1da177e4 | 830 | { |
f6d8bd05 ED |
831 | const struct ip_options *opt = &(IPCB(skb)->opt); |
832 | struct ip_options_rcu *dopt = NULL; | |
1da177e4 LT |
833 | |
834 | if (opt && opt->optlen) { | |
f6d8bd05 ED |
835 | int opt_size = sizeof(*dopt) + opt->optlen; |
836 | ||
1da177e4 LT |
837 | dopt = kmalloc(opt_size, GFP_ATOMIC); |
838 | if (dopt) { | |
f6d8bd05 | 839 | if (ip_options_echo(&dopt->opt, skb)) { |
1da177e4 LT |
840 | kfree(dopt); |
841 | dopt = NULL; | |
842 | } | |
843 | } | |
844 | } | |
845 | return dopt; | |
846 | } | |
847 | ||
cfb6eeb4 YH |
848 | #ifdef CONFIG_TCP_MD5SIG |
849 | /* | |
850 | * RFC2385 MD5 checksumming requires a mapping of | |
851 | * IP address->MD5 Key. | |
852 | * We need to maintain these in the sk structure. | |
853 | */ | |
854 | ||
855 | /* Find the Key structure for an address. */ | |
7174259e ACM |
856 | static struct tcp_md5sig_key * |
857 | tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr) | |
cfb6eeb4 YH |
858 | { |
859 | struct tcp_sock *tp = tcp_sk(sk); | |
860 | int i; | |
861 | ||
862 | if (!tp->md5sig_info || !tp->md5sig_info->entries4) | |
863 | return NULL; | |
864 | for (i = 0; i < tp->md5sig_info->entries4; i++) { | |
865 | if (tp->md5sig_info->keys4[i].addr == addr) | |
f8ab18d2 | 866 | return &tp->md5sig_info->keys4[i].base; |
cfb6eeb4 YH |
867 | } |
868 | return NULL; | |
869 | } | |
870 | ||
871 | struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk, | |
872 | struct sock *addr_sk) | |
873 | { | |
c720c7e8 | 874 | return tcp_v4_md5_do_lookup(sk, inet_sk(addr_sk)->inet_daddr); |
cfb6eeb4 | 875 | } |
cfb6eeb4 YH |
876 | EXPORT_SYMBOL(tcp_v4_md5_lookup); |
877 | ||
f5b99bcd AB |
878 | static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk, |
879 | struct request_sock *req) | |
cfb6eeb4 YH |
880 | { |
881 | return tcp_v4_md5_do_lookup(sk, inet_rsk(req)->rmt_addr); | |
882 | } | |
883 | ||
884 | /* This can be called on a newly created socket, from other files */ | |
885 | int tcp_v4_md5_do_add(struct sock *sk, __be32 addr, | |
886 | u8 *newkey, u8 newkeylen) | |
887 | { | |
888 | /* Add Key to the list */ | |
b0a713e9 | 889 | struct tcp_md5sig_key *key; |
cfb6eeb4 YH |
890 | struct tcp_sock *tp = tcp_sk(sk); |
891 | struct tcp4_md5sig_key *keys; | |
892 | ||
b0a713e9 | 893 | key = tcp_v4_md5_do_lookup(sk, addr); |
cfb6eeb4 YH |
894 | if (key) { |
895 | /* Pre-existing entry - just update that one. */ | |
b0a713e9 MD |
896 | kfree(key->key); |
897 | key->key = newkey; | |
898 | key->keylen = newkeylen; | |
cfb6eeb4 | 899 | } else { |
f6685938 ACM |
900 | struct tcp_md5sig_info *md5sig; |
901 | ||
cfb6eeb4 | 902 | if (!tp->md5sig_info) { |
f6685938 ACM |
903 | tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), |
904 | GFP_ATOMIC); | |
cfb6eeb4 YH |
905 | if (!tp->md5sig_info) { |
906 | kfree(newkey); | |
907 | return -ENOMEM; | |
908 | } | |
a465419b | 909 | sk_nocaps_add(sk, NETIF_F_GSO_MASK); |
cfb6eeb4 | 910 | } |
aa133076 | 911 | if (tcp_alloc_md5sig_pool(sk) == NULL) { |
cfb6eeb4 YH |
912 | kfree(newkey); |
913 | return -ENOMEM; | |
914 | } | |
f6685938 ACM |
915 | md5sig = tp->md5sig_info; |
916 | ||
917 | if (md5sig->alloced4 == md5sig->entries4) { | |
918 | keys = kmalloc((sizeof(*keys) * | |
e905a9ed | 919 | (md5sig->entries4 + 1)), GFP_ATOMIC); |
cfb6eeb4 YH |
920 | if (!keys) { |
921 | kfree(newkey); | |
922 | tcp_free_md5sig_pool(); | |
923 | return -ENOMEM; | |
924 | } | |
925 | ||
f6685938 ACM |
926 | if (md5sig->entries4) |
927 | memcpy(keys, md5sig->keys4, | |
928 | sizeof(*keys) * md5sig->entries4); | |
cfb6eeb4 YH |
929 | |
930 | /* Free old key list, and reference new one */ | |
a80cc20d | 931 | kfree(md5sig->keys4); |
f6685938 ACM |
932 | md5sig->keys4 = keys; |
933 | md5sig->alloced4++; | |
cfb6eeb4 | 934 | } |
f6685938 | 935 | md5sig->entries4++; |
f8ab18d2 DM |
936 | md5sig->keys4[md5sig->entries4 - 1].addr = addr; |
937 | md5sig->keys4[md5sig->entries4 - 1].base.key = newkey; | |
938 | md5sig->keys4[md5sig->entries4 - 1].base.keylen = newkeylen; | |
cfb6eeb4 YH |
939 | } |
940 | return 0; | |
941 | } | |
cfb6eeb4 YH |
942 | EXPORT_SYMBOL(tcp_v4_md5_do_add); |
943 | ||
944 | static int tcp_v4_md5_add_func(struct sock *sk, struct sock *addr_sk, | |
945 | u8 *newkey, u8 newkeylen) | |
946 | { | |
c720c7e8 | 947 | return tcp_v4_md5_do_add(sk, inet_sk(addr_sk)->inet_daddr, |
cfb6eeb4 YH |
948 | newkey, newkeylen); |
949 | } | |
950 | ||
951 | int tcp_v4_md5_do_del(struct sock *sk, __be32 addr) | |
952 | { | |
953 | struct tcp_sock *tp = tcp_sk(sk); | |
954 | int i; | |
955 | ||
956 | for (i = 0; i < tp->md5sig_info->entries4; i++) { | |
957 | if (tp->md5sig_info->keys4[i].addr == addr) { | |
958 | /* Free the key */ | |
f8ab18d2 | 959 | kfree(tp->md5sig_info->keys4[i].base.key); |
cfb6eeb4 YH |
960 | tp->md5sig_info->entries4--; |
961 | ||
962 | if (tp->md5sig_info->entries4 == 0) { | |
963 | kfree(tp->md5sig_info->keys4); | |
964 | tp->md5sig_info->keys4 = NULL; | |
8228a18d | 965 | tp->md5sig_info->alloced4 = 0; |
7174259e | 966 | } else if (tp->md5sig_info->entries4 != i) { |
cfb6eeb4 | 967 | /* Need to do some manipulation */ |
354faf09 YH |
968 | memmove(&tp->md5sig_info->keys4[i], |
969 | &tp->md5sig_info->keys4[i+1], | |
970 | (tp->md5sig_info->entries4 - i) * | |
971 | sizeof(struct tcp4_md5sig_key)); | |
cfb6eeb4 YH |
972 | } |
973 | tcp_free_md5sig_pool(); | |
974 | return 0; | |
975 | } | |
976 | } | |
977 | return -ENOENT; | |
978 | } | |
cfb6eeb4 YH |
979 | EXPORT_SYMBOL(tcp_v4_md5_do_del); |
980 | ||
7174259e | 981 | static void tcp_v4_clear_md5_list(struct sock *sk) |
cfb6eeb4 YH |
982 | { |
983 | struct tcp_sock *tp = tcp_sk(sk); | |
984 | ||
985 | /* Free each key, then the set of key keys, | |
986 | * the crypto element, and then decrement our | |
987 | * hold on the last resort crypto. | |
988 | */ | |
989 | if (tp->md5sig_info->entries4) { | |
990 | int i; | |
991 | for (i = 0; i < tp->md5sig_info->entries4; i++) | |
f8ab18d2 | 992 | kfree(tp->md5sig_info->keys4[i].base.key); |
cfb6eeb4 YH |
993 | tp->md5sig_info->entries4 = 0; |
994 | tcp_free_md5sig_pool(); | |
995 | } | |
996 | if (tp->md5sig_info->keys4) { | |
997 | kfree(tp->md5sig_info->keys4); | |
998 | tp->md5sig_info->keys4 = NULL; | |
999 | tp->md5sig_info->alloced4 = 0; | |
1000 | } | |
1001 | } | |
1002 | ||
7174259e ACM |
1003 | static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval, |
1004 | int optlen) | |
cfb6eeb4 YH |
1005 | { |
1006 | struct tcp_md5sig cmd; | |
1007 | struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr; | |
1008 | u8 *newkey; | |
1009 | ||
1010 | if (optlen < sizeof(cmd)) | |
1011 | return -EINVAL; | |
1012 | ||
7174259e | 1013 | if (copy_from_user(&cmd, optval, sizeof(cmd))) |
cfb6eeb4 YH |
1014 | return -EFAULT; |
1015 | ||
1016 | if (sin->sin_family != AF_INET) | |
1017 | return -EINVAL; | |
1018 | ||
1019 | if (!cmd.tcpm_key || !cmd.tcpm_keylen) { | |
1020 | if (!tcp_sk(sk)->md5sig_info) | |
1021 | return -ENOENT; | |
1022 | return tcp_v4_md5_do_del(sk, sin->sin_addr.s_addr); | |
1023 | } | |
1024 | ||
1025 | if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) | |
1026 | return -EINVAL; | |
1027 | ||
1028 | if (!tcp_sk(sk)->md5sig_info) { | |
1029 | struct tcp_sock *tp = tcp_sk(sk); | |
aa133076 | 1030 | struct tcp_md5sig_info *p; |
cfb6eeb4 | 1031 | |
aa133076 | 1032 | p = kzalloc(sizeof(*p), sk->sk_allocation); |
cfb6eeb4 YH |
1033 | if (!p) |
1034 | return -EINVAL; | |
1035 | ||
1036 | tp->md5sig_info = p; | |
a465419b | 1037 | sk_nocaps_add(sk, NETIF_F_GSO_MASK); |
cfb6eeb4 YH |
1038 | } |
1039 | ||
aa133076 | 1040 | newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, sk->sk_allocation); |
cfb6eeb4 YH |
1041 | if (!newkey) |
1042 | return -ENOMEM; | |
cfb6eeb4 YH |
1043 | return tcp_v4_md5_do_add(sk, sin->sin_addr.s_addr, |
1044 | newkey, cmd.tcpm_keylen); | |
1045 | } | |
1046 | ||
49a72dfb AL |
1047 | static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp, |
1048 | __be32 daddr, __be32 saddr, int nbytes) | |
cfb6eeb4 | 1049 | { |
cfb6eeb4 | 1050 | struct tcp4_pseudohdr *bp; |
49a72dfb | 1051 | struct scatterlist sg; |
cfb6eeb4 YH |
1052 | |
1053 | bp = &hp->md5_blk.ip4; | |
cfb6eeb4 YH |
1054 | |
1055 | /* | |
49a72dfb | 1056 | * 1. the TCP pseudo-header (in the order: source IP address, |
cfb6eeb4 YH |
1057 | * destination IP address, zero-padded protocol number, and |
1058 | * segment length) | |
1059 | */ | |
1060 | bp->saddr = saddr; | |
1061 | bp->daddr = daddr; | |
1062 | bp->pad = 0; | |
076fb722 | 1063 | bp->protocol = IPPROTO_TCP; |
49a72dfb | 1064 | bp->len = cpu_to_be16(nbytes); |
c7da57a1 | 1065 | |
49a72dfb AL |
1066 | sg_init_one(&sg, bp, sizeof(*bp)); |
1067 | return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp)); | |
1068 | } | |
1069 | ||
1070 | static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key, | |
1071 | __be32 daddr, __be32 saddr, struct tcphdr *th) | |
1072 | { | |
1073 | struct tcp_md5sig_pool *hp; | |
1074 | struct hash_desc *desc; | |
1075 | ||
1076 | hp = tcp_get_md5sig_pool(); | |
1077 | if (!hp) | |
1078 | goto clear_hash_noput; | |
1079 | desc = &hp->md5_desc; | |
1080 | ||
1081 | if (crypto_hash_init(desc)) | |
1082 | goto clear_hash; | |
1083 | if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2)) | |
1084 | goto clear_hash; | |
1085 | if (tcp_md5_hash_header(hp, th)) | |
1086 | goto clear_hash; | |
1087 | if (tcp_md5_hash_key(hp, key)) | |
1088 | goto clear_hash; | |
1089 | if (crypto_hash_final(desc, md5_hash)) | |
cfb6eeb4 YH |
1090 | goto clear_hash; |
1091 | ||
cfb6eeb4 | 1092 | tcp_put_md5sig_pool(); |
cfb6eeb4 | 1093 | return 0; |
49a72dfb | 1094 | |
cfb6eeb4 YH |
1095 | clear_hash: |
1096 | tcp_put_md5sig_pool(); | |
1097 | clear_hash_noput: | |
1098 | memset(md5_hash, 0, 16); | |
49a72dfb | 1099 | return 1; |
cfb6eeb4 YH |
1100 | } |
1101 | ||
49a72dfb AL |
1102 | int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key, |
1103 | struct sock *sk, struct request_sock *req, | |
1104 | struct sk_buff *skb) | |
cfb6eeb4 | 1105 | { |
49a72dfb AL |
1106 | struct tcp_md5sig_pool *hp; |
1107 | struct hash_desc *desc; | |
1108 | struct tcphdr *th = tcp_hdr(skb); | |
cfb6eeb4 YH |
1109 | __be32 saddr, daddr; |
1110 | ||
1111 | if (sk) { | |
c720c7e8 ED |
1112 | saddr = inet_sk(sk)->inet_saddr; |
1113 | daddr = inet_sk(sk)->inet_daddr; | |
49a72dfb AL |
1114 | } else if (req) { |
1115 | saddr = inet_rsk(req)->loc_addr; | |
1116 | daddr = inet_rsk(req)->rmt_addr; | |
cfb6eeb4 | 1117 | } else { |
49a72dfb AL |
1118 | const struct iphdr *iph = ip_hdr(skb); |
1119 | saddr = iph->saddr; | |
1120 | daddr = iph->daddr; | |
cfb6eeb4 | 1121 | } |
49a72dfb AL |
1122 | |
1123 | hp = tcp_get_md5sig_pool(); | |
1124 | if (!hp) | |
1125 | goto clear_hash_noput; | |
1126 | desc = &hp->md5_desc; | |
1127 | ||
1128 | if (crypto_hash_init(desc)) | |
1129 | goto clear_hash; | |
1130 | ||
1131 | if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, skb->len)) | |
1132 | goto clear_hash; | |
1133 | if (tcp_md5_hash_header(hp, th)) | |
1134 | goto clear_hash; | |
1135 | if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2)) | |
1136 | goto clear_hash; | |
1137 | if (tcp_md5_hash_key(hp, key)) | |
1138 | goto clear_hash; | |
1139 | if (crypto_hash_final(desc, md5_hash)) | |
1140 | goto clear_hash; | |
1141 | ||
1142 | tcp_put_md5sig_pool(); | |
1143 | return 0; | |
1144 | ||
1145 | clear_hash: | |
1146 | tcp_put_md5sig_pool(); | |
1147 | clear_hash_noput: | |
1148 | memset(md5_hash, 0, 16); | |
1149 | return 1; | |
cfb6eeb4 | 1150 | } |
49a72dfb | 1151 | EXPORT_SYMBOL(tcp_v4_md5_hash_skb); |
cfb6eeb4 | 1152 | |
7174259e | 1153 | static int tcp_v4_inbound_md5_hash(struct sock *sk, struct sk_buff *skb) |
cfb6eeb4 YH |
1154 | { |
1155 | /* | |
1156 | * This gets called for each TCP segment that arrives | |
1157 | * so we want to be efficient. | |
1158 | * We have 3 drop cases: | |
1159 | * o No MD5 hash and one expected. | |
1160 | * o MD5 hash and we're not expecting one. | |
1161 | * o MD5 hash and its wrong. | |
1162 | */ | |
1163 | __u8 *hash_location = NULL; | |
1164 | struct tcp_md5sig_key *hash_expected; | |
eddc9ec5 | 1165 | const struct iphdr *iph = ip_hdr(skb); |
aa8223c7 | 1166 | struct tcphdr *th = tcp_hdr(skb); |
cfb6eeb4 | 1167 | int genhash; |
cfb6eeb4 YH |
1168 | unsigned char newhash[16]; |
1169 | ||
1170 | hash_expected = tcp_v4_md5_do_lookup(sk, iph->saddr); | |
7d5d5525 | 1171 | hash_location = tcp_parse_md5sig_option(th); |
cfb6eeb4 | 1172 | |
cfb6eeb4 YH |
1173 | /* We've parsed the options - do we have a hash? */ |
1174 | if (!hash_expected && !hash_location) | |
1175 | return 0; | |
1176 | ||
1177 | if (hash_expected && !hash_location) { | |
785957d3 | 1178 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); |
cfb6eeb4 YH |
1179 | return 1; |
1180 | } | |
1181 | ||
1182 | if (!hash_expected && hash_location) { | |
785957d3 | 1183 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); |
cfb6eeb4 YH |
1184 | return 1; |
1185 | } | |
1186 | ||
1187 | /* Okay, so this is hash_expected and hash_location - | |
1188 | * so we need to calculate the checksum. | |
1189 | */ | |
49a72dfb AL |
1190 | genhash = tcp_v4_md5_hash_skb(newhash, |
1191 | hash_expected, | |
1192 | NULL, NULL, skb); | |
cfb6eeb4 YH |
1193 | |
1194 | if (genhash || memcmp(hash_location, newhash, 16) != 0) { | |
1195 | if (net_ratelimit()) { | |
673d57e7 HH |
1196 | printk(KERN_INFO "MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n", |
1197 | &iph->saddr, ntohs(th->source), | |
1198 | &iph->daddr, ntohs(th->dest), | |
cfb6eeb4 | 1199 | genhash ? " tcp_v4_calc_md5_hash failed" : ""); |
cfb6eeb4 YH |
1200 | } |
1201 | return 1; | |
1202 | } | |
1203 | return 0; | |
1204 | } | |
1205 | ||
1206 | #endif | |
1207 | ||
72a3effa | 1208 | struct request_sock_ops tcp_request_sock_ops __read_mostly = { |
1da177e4 | 1209 | .family = PF_INET, |
2e6599cb | 1210 | .obj_size = sizeof(struct tcp_request_sock), |
72659ecc | 1211 | .rtx_syn_ack = tcp_v4_rtx_synack, |
60236fdd ACM |
1212 | .send_ack = tcp_v4_reqsk_send_ack, |
1213 | .destructor = tcp_v4_reqsk_destructor, | |
1da177e4 | 1214 | .send_reset = tcp_v4_send_reset, |
72659ecc | 1215 | .syn_ack_timeout = tcp_syn_ack_timeout, |
1da177e4 LT |
1216 | }; |
1217 | ||
cfb6eeb4 | 1218 | #ifdef CONFIG_TCP_MD5SIG |
b2e4b3de | 1219 | static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = { |
cfb6eeb4 | 1220 | .md5_lookup = tcp_v4_reqsk_md5_lookup, |
e3afe7b7 | 1221 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
cfb6eeb4 | 1222 | }; |
b6332e6c | 1223 | #endif |
cfb6eeb4 | 1224 | |
1da177e4 LT |
1225 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) |
1226 | { | |
4957faad | 1227 | struct tcp_extend_values tmp_ext; |
1da177e4 | 1228 | struct tcp_options_received tmp_opt; |
4957faad | 1229 | u8 *hash_location; |
60236fdd | 1230 | struct request_sock *req; |
e6b4d113 | 1231 | struct inet_request_sock *ireq; |
4957faad | 1232 | struct tcp_sock *tp = tcp_sk(sk); |
e6b4d113 | 1233 | struct dst_entry *dst = NULL; |
eddc9ec5 ACM |
1234 | __be32 saddr = ip_hdr(skb)->saddr; |
1235 | __be32 daddr = ip_hdr(skb)->daddr; | |
1da177e4 | 1236 | __u32 isn = TCP_SKB_CB(skb)->when; |
1da177e4 LT |
1237 | #ifdef CONFIG_SYN_COOKIES |
1238 | int want_cookie = 0; | |
1239 | #else | |
1240 | #define want_cookie 0 /* Argh, why doesn't gcc optimize this :( */ | |
1241 | #endif | |
1242 | ||
1243 | /* Never answer to SYNs send to broadcast or multicast */ | |
511c3f92 | 1244 | if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) |
1da177e4 LT |
1245 | goto drop; |
1246 | ||
1247 | /* TW buckets are converted to open requests without | |
1248 | * limitations, they conserve resources and peer is | |
1249 | * evidently real one. | |
1250 | */ | |
463c84b9 | 1251 | if (inet_csk_reqsk_queue_is_full(sk) && !isn) { |
2a1d4bd4 FW |
1252 | if (net_ratelimit()) |
1253 | syn_flood_warning(skb); | |
1da177e4 LT |
1254 | #ifdef CONFIG_SYN_COOKIES |
1255 | if (sysctl_tcp_syncookies) { | |
1256 | want_cookie = 1; | |
1257 | } else | |
1258 | #endif | |
1259 | goto drop; | |
1260 | } | |
1261 | ||
1262 | /* Accept backlog is full. If we have already queued enough | |
1263 | * of warm entries in syn queue, drop request. It is better than | |
1264 | * clogging syn queue with openreqs with exponentially increasing | |
1265 | * timeout. | |
1266 | */ | |
463c84b9 | 1267 | if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) |
1da177e4 LT |
1268 | goto drop; |
1269 | ||
ce4a7d0d | 1270 | req = inet_reqsk_alloc(&tcp_request_sock_ops); |
1da177e4 LT |
1271 | if (!req) |
1272 | goto drop; | |
1273 | ||
cfb6eeb4 YH |
1274 | #ifdef CONFIG_TCP_MD5SIG |
1275 | tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops; | |
1276 | #endif | |
1277 | ||
1da177e4 | 1278 | tcp_clear_options(&tmp_opt); |
bee7ca9e | 1279 | tmp_opt.mss_clamp = TCP_MSS_DEFAULT; |
4957faad | 1280 | tmp_opt.user_mss = tp->rx_opt.user_mss; |
bb5b7c11 | 1281 | tcp_parse_options(skb, &tmp_opt, &hash_location, 0); |
4957faad WAS |
1282 | |
1283 | if (tmp_opt.cookie_plus > 0 && | |
1284 | tmp_opt.saw_tstamp && | |
1285 | !tp->rx_opt.cookie_out_never && | |
1286 | (sysctl_tcp_cookie_size > 0 || | |
1287 | (tp->cookie_values != NULL && | |
1288 | tp->cookie_values->cookie_desired > 0))) { | |
1289 | u8 *c; | |
1290 | u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS]; | |
1291 | int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE; | |
1292 | ||
1293 | if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0) | |
1294 | goto drop_and_release; | |
1295 | ||
1296 | /* Secret recipe starts with IP addresses */ | |
0eae88f3 ED |
1297 | *mess++ ^= (__force u32)daddr; |
1298 | *mess++ ^= (__force u32)saddr; | |
1da177e4 | 1299 | |
4957faad WAS |
1300 | /* plus variable length Initiator Cookie */ |
1301 | c = (u8 *)mess; | |
1302 | while (l-- > 0) | |
1303 | *c++ ^= *hash_location++; | |
1304 | ||
1305 | #ifdef CONFIG_SYN_COOKIES | |
1306 | want_cookie = 0; /* not our kind of cookie */ | |
1307 | #endif | |
1308 | tmp_ext.cookie_out_never = 0; /* false */ | |
1309 | tmp_ext.cookie_plus = tmp_opt.cookie_plus; | |
1310 | } else if (!tp->rx_opt.cookie_in_always) { | |
1311 | /* redundant indications, but ensure initialization. */ | |
1312 | tmp_ext.cookie_out_never = 1; /* true */ | |
1313 | tmp_ext.cookie_plus = 0; | |
1314 | } else { | |
1315 | goto drop_and_release; | |
1316 | } | |
1317 | tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always; | |
1da177e4 | 1318 | |
4dfc2817 | 1319 | if (want_cookie && !tmp_opt.saw_tstamp) |
1da177e4 | 1320 | tcp_clear_options(&tmp_opt); |
1da177e4 | 1321 | |
1da177e4 | 1322 | tmp_opt.tstamp_ok = tmp_opt.saw_tstamp; |
1da177e4 LT |
1323 | tcp_openreq_init(req, &tmp_opt, skb); |
1324 | ||
bb5b7c11 DM |
1325 | ireq = inet_rsk(req); |
1326 | ireq->loc_addr = daddr; | |
1327 | ireq->rmt_addr = saddr; | |
1328 | ireq->no_srccheck = inet_sk(sk)->transparent; | |
1329 | ireq->opt = tcp_v4_save_options(sk, skb); | |
1330 | ||
284904aa | 1331 | if (security_inet_conn_request(sk, skb, req)) |
bb5b7c11 | 1332 | goto drop_and_free; |
284904aa | 1333 | |
172d69e6 | 1334 | if (!want_cookie || tmp_opt.tstamp_ok) |
aa8223c7 | 1335 | TCP_ECN_create_request(req, tcp_hdr(skb)); |
1da177e4 LT |
1336 | |
1337 | if (want_cookie) { | |
1da177e4 | 1338 | isn = cookie_v4_init_sequence(sk, skb, &req->mss); |
172d69e6 | 1339 | req->cookie_ts = tmp_opt.tstamp_ok; |
1da177e4 LT |
1340 | } else if (!isn) { |
1341 | struct inet_peer *peer = NULL; | |
6bd023f3 | 1342 | struct flowi4 fl4; |
1da177e4 LT |
1343 | |
1344 | /* VJ's idea. We save last timestamp seen | |
1345 | * from the destination in peer table, when entering | |
1346 | * state TIME-WAIT, and check against it before | |
1347 | * accepting new connection request. | |
1348 | * | |
1349 | * If "isn" is not zero, this request hit alive | |
1350 | * timewait bucket, so that all the necessary checks | |
1351 | * are made in the function processing timewait state. | |
1352 | */ | |
1353 | if (tmp_opt.saw_tstamp && | |
295ff7ed | 1354 | tcp_death_row.sysctl_tw_recycle && |
6bd023f3 | 1355 | (dst = inet_csk_route_req(sk, &fl4, req)) != NULL && |
1da177e4 | 1356 | (peer = rt_get_peer((struct rtable *)dst)) != NULL && |
7a71ed89 | 1357 | peer->daddr.addr.a4 == saddr) { |
317fe0e6 | 1358 | inet_peer_refcheck(peer); |
2c1409a0 | 1359 | if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL && |
1da177e4 LT |
1360 | (s32)(peer->tcp_ts - req->ts_recent) > |
1361 | TCP_PAWS_WINDOW) { | |
de0744af | 1362 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED); |
7cd04fa7 | 1363 | goto drop_and_release; |
1da177e4 LT |
1364 | } |
1365 | } | |
1366 | /* Kill the following clause, if you dislike this way. */ | |
1367 | else if (!sysctl_tcp_syncookies && | |
463c84b9 | 1368 | (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) < |
1da177e4 LT |
1369 | (sysctl_max_syn_backlog >> 2)) && |
1370 | (!peer || !peer->tcp_ts_stamp) && | |
1371 | (!dst || !dst_metric(dst, RTAX_RTT))) { | |
1372 | /* Without syncookies last quarter of | |
1373 | * backlog is filled with destinations, | |
1374 | * proven to be alive. | |
1375 | * It means that we continue to communicate | |
1376 | * to destinations, already remembered | |
1377 | * to the moment of synflood. | |
1378 | */ | |
673d57e7 HH |
1379 | LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI4/%u\n", |
1380 | &saddr, ntohs(tcp_hdr(skb)->source)); | |
7cd04fa7 | 1381 | goto drop_and_release; |
1da177e4 LT |
1382 | } |
1383 | ||
a94f723d | 1384 | isn = tcp_v4_init_sequence(skb); |
1da177e4 | 1385 | } |
2e6599cb | 1386 | tcp_rsk(req)->snt_isn = isn; |
1da177e4 | 1387 | |
72659ecc OP |
1388 | if (tcp_v4_send_synack(sk, dst, req, |
1389 | (struct request_values *)&tmp_ext) || | |
4957faad | 1390 | want_cookie) |
1da177e4 LT |
1391 | goto drop_and_free; |
1392 | ||
7cd04fa7 | 1393 | inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); |
1da177e4 LT |
1394 | return 0; |
1395 | ||
7cd04fa7 DL |
1396 | drop_and_release: |
1397 | dst_release(dst); | |
1da177e4 | 1398 | drop_and_free: |
60236fdd | 1399 | reqsk_free(req); |
1da177e4 | 1400 | drop: |
1da177e4 LT |
1401 | return 0; |
1402 | } | |
4bc2f18b | 1403 | EXPORT_SYMBOL(tcp_v4_conn_request); |
1da177e4 LT |
1404 | |
1405 | ||
1406 | /* | |
1407 | * The three way handshake has completed - we got a valid synack - | |
1408 | * now create the new socket. | |
1409 | */ | |
1410 | struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, | |
60236fdd | 1411 | struct request_sock *req, |
1da177e4 LT |
1412 | struct dst_entry *dst) |
1413 | { | |
2e6599cb | 1414 | struct inet_request_sock *ireq; |
1da177e4 LT |
1415 | struct inet_sock *newinet; |
1416 | struct tcp_sock *newtp; | |
1417 | struct sock *newsk; | |
cfb6eeb4 YH |
1418 | #ifdef CONFIG_TCP_MD5SIG |
1419 | struct tcp_md5sig_key *key; | |
1420 | #endif | |
f6d8bd05 | 1421 | struct ip_options_rcu *inet_opt; |
1da177e4 LT |
1422 | |
1423 | if (sk_acceptq_is_full(sk)) | |
1424 | goto exit_overflow; | |
1425 | ||
1da177e4 LT |
1426 | newsk = tcp_create_openreq_child(sk, req, skb); |
1427 | if (!newsk) | |
093d2823 | 1428 | goto exit_nonewsk; |
1da177e4 | 1429 | |
bcd76111 | 1430 | newsk->sk_gso_type = SKB_GSO_TCPV4; |
1da177e4 LT |
1431 | |
1432 | newtp = tcp_sk(newsk); | |
1433 | newinet = inet_sk(newsk); | |
2e6599cb | 1434 | ireq = inet_rsk(req); |
c720c7e8 ED |
1435 | newinet->inet_daddr = ireq->rmt_addr; |
1436 | newinet->inet_rcv_saddr = ireq->loc_addr; | |
1437 | newinet->inet_saddr = ireq->loc_addr; | |
f6d8bd05 ED |
1438 | inet_opt = ireq->opt; |
1439 | rcu_assign_pointer(newinet->inet_opt, inet_opt); | |
2e6599cb | 1440 | ireq->opt = NULL; |
463c84b9 | 1441 | newinet->mc_index = inet_iif(skb); |
eddc9ec5 | 1442 | newinet->mc_ttl = ip_hdr(skb)->ttl; |
d83d8461 | 1443 | inet_csk(newsk)->icsk_ext_hdr_len = 0; |
f6d8bd05 ED |
1444 | if (inet_opt) |
1445 | inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen; | |
c720c7e8 | 1446 | newinet->inet_id = newtp->write_seq ^ jiffies; |
1da177e4 | 1447 | |
0e734419 DM |
1448 | if (!dst && (dst = inet_csk_route_child_sock(sk, newsk, req)) == NULL) |
1449 | goto put_and_exit; | |
1450 | ||
1451 | sk_setup_caps(newsk, dst); | |
1452 | ||
5d424d5a | 1453 | tcp_mtup_init(newsk); |
1da177e4 | 1454 | tcp_sync_mss(newsk, dst_mtu(dst)); |
0dbaee3b | 1455 | newtp->advmss = dst_metric_advmss(dst); |
f5fff5dc TQ |
1456 | if (tcp_sk(sk)->rx_opt.user_mss && |
1457 | tcp_sk(sk)->rx_opt.user_mss < newtp->advmss) | |
1458 | newtp->advmss = tcp_sk(sk)->rx_opt.user_mss; | |
1459 | ||
1da177e4 LT |
1460 | tcp_initialize_rcv_mss(newsk); |
1461 | ||
cfb6eeb4 YH |
1462 | #ifdef CONFIG_TCP_MD5SIG |
1463 | /* Copy over the MD5 key from the original socket */ | |
c720c7e8 ED |
1464 | key = tcp_v4_md5_do_lookup(sk, newinet->inet_daddr); |
1465 | if (key != NULL) { | |
cfb6eeb4 YH |
1466 | /* |
1467 | * We're using one, so create a matching key | |
1468 | * on the newsk structure. If we fail to get | |
1469 | * memory, then we end up not copying the key | |
1470 | * across. Shucks. | |
1471 | */ | |
f6685938 ACM |
1472 | char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC); |
1473 | if (newkey != NULL) | |
c720c7e8 | 1474 | tcp_v4_md5_do_add(newsk, newinet->inet_daddr, |
cfb6eeb4 | 1475 | newkey, key->keylen); |
a465419b | 1476 | sk_nocaps_add(newsk, NETIF_F_GSO_MASK); |
cfb6eeb4 YH |
1477 | } |
1478 | #endif | |
1479 | ||
0e734419 DM |
1480 | if (__inet_inherit_port(sk, newsk) < 0) |
1481 | goto put_and_exit; | |
9327f705 | 1482 | __inet_hash_nolisten(newsk, NULL); |
1da177e4 LT |
1483 | |
1484 | return newsk; | |
1485 | ||
1486 | exit_overflow: | |
de0744af | 1487 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); |
093d2823 BS |
1488 | exit_nonewsk: |
1489 | dst_release(dst); | |
1da177e4 | 1490 | exit: |
de0744af | 1491 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); |
1da177e4 | 1492 | return NULL; |
0e734419 DM |
1493 | put_and_exit: |
1494 | sock_put(newsk); | |
1495 | goto exit; | |
1da177e4 | 1496 | } |
4bc2f18b | 1497 | EXPORT_SYMBOL(tcp_v4_syn_recv_sock); |
1da177e4 LT |
1498 | |
1499 | static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb) | |
1500 | { | |
aa8223c7 | 1501 | struct tcphdr *th = tcp_hdr(skb); |
eddc9ec5 | 1502 | const struct iphdr *iph = ip_hdr(skb); |
1da177e4 | 1503 | struct sock *nsk; |
60236fdd | 1504 | struct request_sock **prev; |
1da177e4 | 1505 | /* Find possible connection requests. */ |
463c84b9 ACM |
1506 | struct request_sock *req = inet_csk_search_req(sk, &prev, th->source, |
1507 | iph->saddr, iph->daddr); | |
1da177e4 LT |
1508 | if (req) |
1509 | return tcp_check_req(sk, skb, req, prev); | |
1510 | ||
3b1e0a65 | 1511 | nsk = inet_lookup_established(sock_net(sk), &tcp_hashinfo, iph->saddr, |
c67499c0 | 1512 | th->source, iph->daddr, th->dest, inet_iif(skb)); |
1da177e4 LT |
1513 | |
1514 | if (nsk) { | |
1515 | if (nsk->sk_state != TCP_TIME_WAIT) { | |
1516 | bh_lock_sock(nsk); | |
1517 | return nsk; | |
1518 | } | |
9469c7b4 | 1519 | inet_twsk_put(inet_twsk(nsk)); |
1da177e4 LT |
1520 | return NULL; |
1521 | } | |
1522 | ||
1523 | #ifdef CONFIG_SYN_COOKIES | |
af9b4738 | 1524 | if (!th->syn) |
1da177e4 LT |
1525 | sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt)); |
1526 | #endif | |
1527 | return sk; | |
1528 | } | |
1529 | ||
b51655b9 | 1530 | static __sum16 tcp_v4_checksum_init(struct sk_buff *skb) |
1da177e4 | 1531 | { |
eddc9ec5 ACM |
1532 | const struct iphdr *iph = ip_hdr(skb); |
1533 | ||
84fa7933 | 1534 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
eddc9ec5 ACM |
1535 | if (!tcp_v4_check(skb->len, iph->saddr, |
1536 | iph->daddr, skb->csum)) { | |
fb286bb2 | 1537 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
1da177e4 | 1538 | return 0; |
fb286bb2 | 1539 | } |
1da177e4 | 1540 | } |
fb286bb2 | 1541 | |
eddc9ec5 | 1542 | skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, |
fb286bb2 HX |
1543 | skb->len, IPPROTO_TCP, 0); |
1544 | ||
1da177e4 | 1545 | if (skb->len <= 76) { |
fb286bb2 | 1546 | return __skb_checksum_complete(skb); |
1da177e4 LT |
1547 | } |
1548 | return 0; | |
1549 | } | |
1550 | ||
1551 | ||
1552 | /* The socket must have it's spinlock held when we get | |
1553 | * here. | |
1554 | * | |
1555 | * We have a potential double-lock case here, so even when | |
1556 | * doing backlog processing we use the BH locking scheme. | |
1557 | * This is because we cannot sleep with the original spinlock | |
1558 | * held. | |
1559 | */ | |
1560 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) | |
1561 | { | |
cfb6eeb4 YH |
1562 | struct sock *rsk; |
1563 | #ifdef CONFIG_TCP_MD5SIG | |
1564 | /* | |
1565 | * We really want to reject the packet as early as possible | |
1566 | * if: | |
1567 | * o We're expecting an MD5'd packet and this is no MD5 tcp option | |
1568 | * o There is an MD5 option and we're not expecting one | |
1569 | */ | |
7174259e | 1570 | if (tcp_v4_inbound_md5_hash(sk, skb)) |
cfb6eeb4 YH |
1571 | goto discard; |
1572 | #endif | |
1573 | ||
1da177e4 | 1574 | if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ |
ca55158c | 1575 | sock_rps_save_rxhash(sk, skb->rxhash); |
aa8223c7 | 1576 | if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) { |
cfb6eeb4 | 1577 | rsk = sk; |
1da177e4 | 1578 | goto reset; |
cfb6eeb4 | 1579 | } |
1da177e4 LT |
1580 | return 0; |
1581 | } | |
1582 | ||
ab6a5bb6 | 1583 | if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb)) |
1da177e4 LT |
1584 | goto csum_err; |
1585 | ||
1586 | if (sk->sk_state == TCP_LISTEN) { | |
1587 | struct sock *nsk = tcp_v4_hnd_req(sk, skb); | |
1588 | if (!nsk) | |
1589 | goto discard; | |
1590 | ||
1591 | if (nsk != sk) { | |
cfb6eeb4 YH |
1592 | if (tcp_child_process(sk, nsk, skb)) { |
1593 | rsk = nsk; | |
1da177e4 | 1594 | goto reset; |
cfb6eeb4 | 1595 | } |
1da177e4 LT |
1596 | return 0; |
1597 | } | |
ca55158c ED |
1598 | } else |
1599 | sock_rps_save_rxhash(sk, skb->rxhash); | |
1600 | ||
aa8223c7 | 1601 | if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) { |
cfb6eeb4 | 1602 | rsk = sk; |
1da177e4 | 1603 | goto reset; |
cfb6eeb4 | 1604 | } |
1da177e4 LT |
1605 | return 0; |
1606 | ||
1607 | reset: | |
cfb6eeb4 | 1608 | tcp_v4_send_reset(rsk, skb); |
1da177e4 LT |
1609 | discard: |
1610 | kfree_skb(skb); | |
1611 | /* Be careful here. If this function gets more complicated and | |
1612 | * gcc suffers from register pressure on the x86, sk (in %ebx) | |
1613 | * might be destroyed here. This current version compiles correctly, | |
1614 | * but you have been warned. | |
1615 | */ | |
1616 | return 0; | |
1617 | ||
1618 | csum_err: | |
63231bdd | 1619 | TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS); |
1da177e4 LT |
1620 | goto discard; |
1621 | } | |
4bc2f18b | 1622 | EXPORT_SYMBOL(tcp_v4_do_rcv); |
1da177e4 LT |
1623 | |
1624 | /* | |
1625 | * From tcp_input.c | |
1626 | */ | |
1627 | ||
1628 | int tcp_v4_rcv(struct sk_buff *skb) | |
1629 | { | |
eddc9ec5 | 1630 | const struct iphdr *iph; |
1da177e4 LT |
1631 | struct tcphdr *th; |
1632 | struct sock *sk; | |
1633 | int ret; | |
a86b1e30 | 1634 | struct net *net = dev_net(skb->dev); |
1da177e4 LT |
1635 | |
1636 | if (skb->pkt_type != PACKET_HOST) | |
1637 | goto discard_it; | |
1638 | ||
1639 | /* Count it even if it's bad */ | |
63231bdd | 1640 | TCP_INC_STATS_BH(net, TCP_MIB_INSEGS); |
1da177e4 LT |
1641 | |
1642 | if (!pskb_may_pull(skb, sizeof(struct tcphdr))) | |
1643 | goto discard_it; | |
1644 | ||
aa8223c7 | 1645 | th = tcp_hdr(skb); |
1da177e4 LT |
1646 | |
1647 | if (th->doff < sizeof(struct tcphdr) / 4) | |
1648 | goto bad_packet; | |
1649 | if (!pskb_may_pull(skb, th->doff * 4)) | |
1650 | goto discard_it; | |
1651 | ||
1652 | /* An explanation is required here, I think. | |
1653 | * Packet length and doff are validated by header prediction, | |
caa20d9a | 1654 | * provided case of th->doff==0 is eliminated. |
1da177e4 | 1655 | * So, we defer the checks. */ |
60476372 | 1656 | if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb)) |
1da177e4 LT |
1657 | goto bad_packet; |
1658 | ||
aa8223c7 | 1659 | th = tcp_hdr(skb); |
eddc9ec5 | 1660 | iph = ip_hdr(skb); |
1da177e4 LT |
1661 | TCP_SKB_CB(skb)->seq = ntohl(th->seq); |
1662 | TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + | |
1663 | skb->len - th->doff * 4); | |
1664 | TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); | |
1665 | TCP_SKB_CB(skb)->when = 0; | |
eddc9ec5 | 1666 | TCP_SKB_CB(skb)->flags = iph->tos; |
1da177e4 LT |
1667 | TCP_SKB_CB(skb)->sacked = 0; |
1668 | ||
9a1f27c4 | 1669 | sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest); |
1da177e4 LT |
1670 | if (!sk) |
1671 | goto no_tcp_socket; | |
1672 | ||
bb134d5d ED |
1673 | process: |
1674 | if (sk->sk_state == TCP_TIME_WAIT) | |
1675 | goto do_time_wait; | |
1676 | ||
6cce09f8 ED |
1677 | if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { |
1678 | NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP); | |
d218d111 | 1679 | goto discard_and_relse; |
6cce09f8 | 1680 | } |
d218d111 | 1681 | |
1da177e4 LT |
1682 | if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) |
1683 | goto discard_and_relse; | |
b59c2701 | 1684 | nf_reset(skb); |
1da177e4 | 1685 | |
fda9ef5d | 1686 | if (sk_filter(sk, skb)) |
1da177e4 LT |
1687 | goto discard_and_relse; |
1688 | ||
1689 | skb->dev = NULL; | |
1690 | ||
c6366184 | 1691 | bh_lock_sock_nested(sk); |
1da177e4 LT |
1692 | ret = 0; |
1693 | if (!sock_owned_by_user(sk)) { | |
1a2449a8 CL |
1694 | #ifdef CONFIG_NET_DMA |
1695 | struct tcp_sock *tp = tcp_sk(sk); | |
1696 | if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) | |
f67b4599 | 1697 | tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY); |
1a2449a8 | 1698 | if (tp->ucopy.dma_chan) |
1da177e4 | 1699 | ret = tcp_v4_do_rcv(sk, skb); |
1a2449a8 CL |
1700 | else |
1701 | #endif | |
1702 | { | |
1703 | if (!tcp_prequeue(sk, skb)) | |
ae8d7f88 | 1704 | ret = tcp_v4_do_rcv(sk, skb); |
1a2449a8 | 1705 | } |
6cce09f8 | 1706 | } else if (unlikely(sk_add_backlog(sk, skb))) { |
6b03a53a | 1707 | bh_unlock_sock(sk); |
6cce09f8 | 1708 | NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP); |
6b03a53a ZY |
1709 | goto discard_and_relse; |
1710 | } | |
1da177e4 LT |
1711 | bh_unlock_sock(sk); |
1712 | ||
1713 | sock_put(sk); | |
1714 | ||
1715 | return ret; | |
1716 | ||
1717 | no_tcp_socket: | |
1718 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) | |
1719 | goto discard_it; | |
1720 | ||
1721 | if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) { | |
1722 | bad_packet: | |
63231bdd | 1723 | TCP_INC_STATS_BH(net, TCP_MIB_INERRS); |
1da177e4 | 1724 | } else { |
cfb6eeb4 | 1725 | tcp_v4_send_reset(NULL, skb); |
1da177e4 LT |
1726 | } |
1727 | ||
1728 | discard_it: | |
1729 | /* Discard frame. */ | |
1730 | kfree_skb(skb); | |
e905a9ed | 1731 | return 0; |
1da177e4 LT |
1732 | |
1733 | discard_and_relse: | |
1734 | sock_put(sk); | |
1735 | goto discard_it; | |
1736 | ||
1737 | do_time_wait: | |
1738 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { | |
9469c7b4 | 1739 | inet_twsk_put(inet_twsk(sk)); |
1da177e4 LT |
1740 | goto discard_it; |
1741 | } | |
1742 | ||
1743 | if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) { | |
63231bdd | 1744 | TCP_INC_STATS_BH(net, TCP_MIB_INERRS); |
9469c7b4 | 1745 | inet_twsk_put(inet_twsk(sk)); |
1da177e4 LT |
1746 | goto discard_it; |
1747 | } | |
9469c7b4 | 1748 | switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { |
1da177e4 | 1749 | case TCP_TW_SYN: { |
c346dca1 | 1750 | struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev), |
c67499c0 | 1751 | &tcp_hashinfo, |
eddc9ec5 | 1752 | iph->daddr, th->dest, |
463c84b9 | 1753 | inet_iif(skb)); |
1da177e4 | 1754 | if (sk2) { |
9469c7b4 YH |
1755 | inet_twsk_deschedule(inet_twsk(sk), &tcp_death_row); |
1756 | inet_twsk_put(inet_twsk(sk)); | |
1da177e4 LT |
1757 | sk = sk2; |
1758 | goto process; | |
1759 | } | |
1760 | /* Fall through to ACK */ | |
1761 | } | |
1762 | case TCP_TW_ACK: | |
1763 | tcp_v4_timewait_ack(sk, skb); | |
1764 | break; | |
1765 | case TCP_TW_RST: | |
1766 | goto no_tcp_socket; | |
1767 | case TCP_TW_SUCCESS:; | |
1768 | } | |
1769 | goto discard_it; | |
1770 | } | |
1771 | ||
3f419d2d | 1772 | struct inet_peer *tcp_v4_get_peer(struct sock *sk, bool *release_it) |
1da177e4 | 1773 | { |
3f419d2d | 1774 | struct rtable *rt = (struct rtable *) __sk_dst_get(sk); |
1da177e4 | 1775 | struct inet_sock *inet = inet_sk(sk); |
3f419d2d | 1776 | struct inet_peer *peer; |
1da177e4 | 1777 | |
c5216cc7 DM |
1778 | if (!rt || |
1779 | inet->cork.fl.u.ip4.daddr != inet->inet_daddr) { | |
b534ecf1 | 1780 | peer = inet_getpeer_v4(inet->inet_daddr, 1); |
3f419d2d | 1781 | *release_it = true; |
1da177e4 LT |
1782 | } else { |
1783 | if (!rt->peer) | |
1784 | rt_bind_peer(rt, 1); | |
1785 | peer = rt->peer; | |
3f419d2d | 1786 | *release_it = false; |
1da177e4 LT |
1787 | } |
1788 | ||
3f419d2d | 1789 | return peer; |
1da177e4 | 1790 | } |
3f419d2d | 1791 | EXPORT_SYMBOL(tcp_v4_get_peer); |
1da177e4 | 1792 | |
ccb7c410 | 1793 | void *tcp_v4_tw_get_peer(struct sock *sk) |
1da177e4 | 1794 | { |
ccb7c410 | 1795 | struct inet_timewait_sock *tw = inet_twsk(sk); |
1da177e4 | 1796 | |
ccb7c410 | 1797 | return inet_getpeer_v4(tw->tw_daddr, 1); |
1da177e4 | 1798 | } |
ccb7c410 DM |
1799 | EXPORT_SYMBOL(tcp_v4_tw_get_peer); |
1800 | ||
1801 | static struct timewait_sock_ops tcp_timewait_sock_ops = { | |
1802 | .twsk_obj_size = sizeof(struct tcp_timewait_sock), | |
1803 | .twsk_unique = tcp_twsk_unique, | |
1804 | .twsk_destructor= tcp_twsk_destructor, | |
1805 | .twsk_getpeer = tcp_v4_tw_get_peer, | |
1806 | }; | |
1da177e4 | 1807 | |
3b401a81 | 1808 | const struct inet_connection_sock_af_ops ipv4_specific = { |
543d9cfe ACM |
1809 | .queue_xmit = ip_queue_xmit, |
1810 | .send_check = tcp_v4_send_check, | |
1811 | .rebuild_header = inet_sk_rebuild_header, | |
1812 | .conn_request = tcp_v4_conn_request, | |
1813 | .syn_recv_sock = tcp_v4_syn_recv_sock, | |
3f419d2d | 1814 | .get_peer = tcp_v4_get_peer, |
543d9cfe ACM |
1815 | .net_header_len = sizeof(struct iphdr), |
1816 | .setsockopt = ip_setsockopt, | |
1817 | .getsockopt = ip_getsockopt, | |
1818 | .addr2sockaddr = inet_csk_addr2sockaddr, | |
1819 | .sockaddr_len = sizeof(struct sockaddr_in), | |
ab1e0a13 | 1820 | .bind_conflict = inet_csk_bind_conflict, |
3fdadf7d | 1821 | #ifdef CONFIG_COMPAT |
543d9cfe ACM |
1822 | .compat_setsockopt = compat_ip_setsockopt, |
1823 | .compat_getsockopt = compat_ip_getsockopt, | |
3fdadf7d | 1824 | #endif |
1da177e4 | 1825 | }; |
4bc2f18b | 1826 | EXPORT_SYMBOL(ipv4_specific); |
1da177e4 | 1827 | |
cfb6eeb4 | 1828 | #ifdef CONFIG_TCP_MD5SIG |
b2e4b3de | 1829 | static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = { |
cfb6eeb4 | 1830 | .md5_lookup = tcp_v4_md5_lookup, |
49a72dfb | 1831 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
cfb6eeb4 YH |
1832 | .md5_add = tcp_v4_md5_add_func, |
1833 | .md5_parse = tcp_v4_parse_md5_keys, | |
cfb6eeb4 | 1834 | }; |
b6332e6c | 1835 | #endif |
cfb6eeb4 | 1836 | |
1da177e4 LT |
1837 | /* NOTE: A lot of things set to zero explicitly by call to |
1838 | * sk_alloc() so need not be done here. | |
1839 | */ | |
1840 | static int tcp_v4_init_sock(struct sock *sk) | |
1841 | { | |
6687e988 | 1842 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 LT |
1843 | struct tcp_sock *tp = tcp_sk(sk); |
1844 | ||
1845 | skb_queue_head_init(&tp->out_of_order_queue); | |
1846 | tcp_init_xmit_timers(sk); | |
1847 | tcp_prequeue_init(tp); | |
1848 | ||
6687e988 | 1849 | icsk->icsk_rto = TCP_TIMEOUT_INIT; |
1da177e4 LT |
1850 | tp->mdev = TCP_TIMEOUT_INIT; |
1851 | ||
1852 | /* So many TCP implementations out there (incorrectly) count the | |
1853 | * initial SYN frame in their delayed-ACK and congestion control | |
1854 | * algorithms that we must have the following bandaid to talk | |
1855 | * efficiently to them. -DaveM | |
1856 | */ | |
1857 | tp->snd_cwnd = 2; | |
1858 | ||
1859 | /* See draft-stevens-tcpca-spec-01 for discussion of the | |
1860 | * initialization of these values. | |
1861 | */ | |
0b6a05c1 | 1862 | tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; |
1da177e4 | 1863 | tp->snd_cwnd_clamp = ~0; |
bee7ca9e | 1864 | tp->mss_cache = TCP_MSS_DEFAULT; |
1da177e4 LT |
1865 | |
1866 | tp->reordering = sysctl_tcp_reordering; | |
6687e988 | 1867 | icsk->icsk_ca_ops = &tcp_init_congestion_ops; |
1da177e4 LT |
1868 | |
1869 | sk->sk_state = TCP_CLOSE; | |
1870 | ||
1871 | sk->sk_write_space = sk_stream_write_space; | |
1872 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
1873 | ||
8292a17a | 1874 | icsk->icsk_af_ops = &ipv4_specific; |
d83d8461 | 1875 | icsk->icsk_sync_mss = tcp_sync_mss; |
cfb6eeb4 YH |
1876 | #ifdef CONFIG_TCP_MD5SIG |
1877 | tp->af_specific = &tcp_sock_ipv4_specific; | |
1878 | #endif | |
1da177e4 | 1879 | |
435cf559 WAS |
1880 | /* TCP Cookie Transactions */ |
1881 | if (sysctl_tcp_cookie_size > 0) { | |
1882 | /* Default, cookies without s_data_payload. */ | |
1883 | tp->cookie_values = | |
1884 | kzalloc(sizeof(*tp->cookie_values), | |
1885 | sk->sk_allocation); | |
1886 | if (tp->cookie_values != NULL) | |
1887 | kref_init(&tp->cookie_values->kref); | |
1888 | } | |
1889 | /* Presumed zeroed, in order of appearance: | |
1890 | * cookie_in_always, cookie_out_never, | |
1891 | * s_data_constant, s_data_in, s_data_out | |
1892 | */ | |
1da177e4 LT |
1893 | sk->sk_sndbuf = sysctl_tcp_wmem[1]; |
1894 | sk->sk_rcvbuf = sysctl_tcp_rmem[1]; | |
1895 | ||
eb4dea58 | 1896 | local_bh_disable(); |
1748376b | 1897 | percpu_counter_inc(&tcp_sockets_allocated); |
eb4dea58 | 1898 | local_bh_enable(); |
1da177e4 LT |
1899 | |
1900 | return 0; | |
1901 | } | |
1902 | ||
7d06b2e0 | 1903 | void tcp_v4_destroy_sock(struct sock *sk) |
1da177e4 LT |
1904 | { |
1905 | struct tcp_sock *tp = tcp_sk(sk); | |
1906 | ||
1907 | tcp_clear_xmit_timers(sk); | |
1908 | ||
6687e988 | 1909 | tcp_cleanup_congestion_control(sk); |
317a76f9 | 1910 | |
1da177e4 | 1911 | /* Cleanup up the write buffer. */ |
fe067e8a | 1912 | tcp_write_queue_purge(sk); |
1da177e4 LT |
1913 | |
1914 | /* Cleans up our, hopefully empty, out_of_order_queue. */ | |
e905a9ed | 1915 | __skb_queue_purge(&tp->out_of_order_queue); |
1da177e4 | 1916 | |
cfb6eeb4 YH |
1917 | #ifdef CONFIG_TCP_MD5SIG |
1918 | /* Clean up the MD5 key list, if any */ | |
1919 | if (tp->md5sig_info) { | |
1920 | tcp_v4_clear_md5_list(sk); | |
1921 | kfree(tp->md5sig_info); | |
1922 | tp->md5sig_info = NULL; | |
1923 | } | |
1924 | #endif | |
1925 | ||
1a2449a8 CL |
1926 | #ifdef CONFIG_NET_DMA |
1927 | /* Cleans up our sk_async_wait_queue */ | |
e905a9ed | 1928 | __skb_queue_purge(&sk->sk_async_wait_queue); |
1a2449a8 CL |
1929 | #endif |
1930 | ||
1da177e4 LT |
1931 | /* Clean prequeue, it must be empty really */ |
1932 | __skb_queue_purge(&tp->ucopy.prequeue); | |
1933 | ||
1934 | /* Clean up a referenced TCP bind bucket. */ | |
463c84b9 | 1935 | if (inet_csk(sk)->icsk_bind_hash) |
ab1e0a13 | 1936 | inet_put_port(sk); |
1da177e4 LT |
1937 | |
1938 | /* | |
1939 | * If sendmsg cached page exists, toss it. | |
1940 | */ | |
1941 | if (sk->sk_sndmsg_page) { | |
1942 | __free_page(sk->sk_sndmsg_page); | |
1943 | sk->sk_sndmsg_page = NULL; | |
1944 | } | |
1945 | ||
435cf559 WAS |
1946 | /* TCP Cookie Transactions */ |
1947 | if (tp->cookie_values != NULL) { | |
1948 | kref_put(&tp->cookie_values->kref, | |
1949 | tcp_cookie_values_release); | |
1950 | tp->cookie_values = NULL; | |
1951 | } | |
1952 | ||
1748376b | 1953 | percpu_counter_dec(&tcp_sockets_allocated); |
1da177e4 | 1954 | } |
1da177e4 LT |
1955 | EXPORT_SYMBOL(tcp_v4_destroy_sock); |
1956 | ||
1957 | #ifdef CONFIG_PROC_FS | |
1958 | /* Proc filesystem TCP sock list dumping. */ | |
1959 | ||
3ab5aee7 | 1960 | static inline struct inet_timewait_sock *tw_head(struct hlist_nulls_head *head) |
1da177e4 | 1961 | { |
3ab5aee7 | 1962 | return hlist_nulls_empty(head) ? NULL : |
8feaf0c0 | 1963 | list_entry(head->first, struct inet_timewait_sock, tw_node); |
1da177e4 LT |
1964 | } |
1965 | ||
8feaf0c0 | 1966 | static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw) |
1da177e4 | 1967 | { |
3ab5aee7 ED |
1968 | return !is_a_nulls(tw->tw_node.next) ? |
1969 | hlist_nulls_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL; | |
1da177e4 LT |
1970 | } |
1971 | ||
a8b690f9 TH |
1972 | /* |
1973 | * Get next listener socket follow cur. If cur is NULL, get first socket | |
1974 | * starting from bucket given in st->bucket; when st->bucket is zero the | |
1975 | * very first socket in the hash table is returned. | |
1976 | */ | |
1da177e4 LT |
1977 | static void *listening_get_next(struct seq_file *seq, void *cur) |
1978 | { | |
463c84b9 | 1979 | struct inet_connection_sock *icsk; |
c25eb3bf | 1980 | struct hlist_nulls_node *node; |
1da177e4 | 1981 | struct sock *sk = cur; |
5caea4ea | 1982 | struct inet_listen_hashbucket *ilb; |
5799de0b | 1983 | struct tcp_iter_state *st = seq->private; |
a4146b1b | 1984 | struct net *net = seq_file_net(seq); |
1da177e4 LT |
1985 | |
1986 | if (!sk) { | |
a8b690f9 | 1987 | ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
5caea4ea | 1988 | spin_lock_bh(&ilb->lock); |
c25eb3bf | 1989 | sk = sk_nulls_head(&ilb->head); |
a8b690f9 | 1990 | st->offset = 0; |
1da177e4 LT |
1991 | goto get_sk; |
1992 | } | |
5caea4ea | 1993 | ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
1da177e4 | 1994 | ++st->num; |
a8b690f9 | 1995 | ++st->offset; |
1da177e4 LT |
1996 | |
1997 | if (st->state == TCP_SEQ_STATE_OPENREQ) { | |
60236fdd | 1998 | struct request_sock *req = cur; |
1da177e4 | 1999 | |
72a3effa | 2000 | icsk = inet_csk(st->syn_wait_sk); |
1da177e4 LT |
2001 | req = req->dl_next; |
2002 | while (1) { | |
2003 | while (req) { | |
bdccc4ca | 2004 | if (req->rsk_ops->family == st->family) { |
1da177e4 LT |
2005 | cur = req; |
2006 | goto out; | |
2007 | } | |
2008 | req = req->dl_next; | |
2009 | } | |
72a3effa | 2010 | if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries) |
1da177e4 LT |
2011 | break; |
2012 | get_req: | |
463c84b9 | 2013 | req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket]; |
1da177e4 | 2014 | } |
1bde5ac4 | 2015 | sk = sk_nulls_next(st->syn_wait_sk); |
1da177e4 | 2016 | st->state = TCP_SEQ_STATE_LISTENING; |
463c84b9 | 2017 | read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
1da177e4 | 2018 | } else { |
e905a9ed | 2019 | icsk = inet_csk(sk); |
463c84b9 ACM |
2020 | read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
2021 | if (reqsk_queue_len(&icsk->icsk_accept_queue)) | |
1da177e4 | 2022 | goto start_req; |
463c84b9 | 2023 | read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
1bde5ac4 | 2024 | sk = sk_nulls_next(sk); |
1da177e4 LT |
2025 | } |
2026 | get_sk: | |
c25eb3bf | 2027 | sk_nulls_for_each_from(sk, node) { |
8475ef9f PE |
2028 | if (!net_eq(sock_net(sk), net)) |
2029 | continue; | |
2030 | if (sk->sk_family == st->family) { | |
1da177e4 LT |
2031 | cur = sk; |
2032 | goto out; | |
2033 | } | |
e905a9ed | 2034 | icsk = inet_csk(sk); |
463c84b9 ACM |
2035 | read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
2036 | if (reqsk_queue_len(&icsk->icsk_accept_queue)) { | |
1da177e4 LT |
2037 | start_req: |
2038 | st->uid = sock_i_uid(sk); | |
2039 | st->syn_wait_sk = sk; | |
2040 | st->state = TCP_SEQ_STATE_OPENREQ; | |
2041 | st->sbucket = 0; | |
2042 | goto get_req; | |
2043 | } | |
463c84b9 | 2044 | read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
1da177e4 | 2045 | } |
5caea4ea | 2046 | spin_unlock_bh(&ilb->lock); |
a8b690f9 | 2047 | st->offset = 0; |
0f7ff927 | 2048 | if (++st->bucket < INET_LHTABLE_SIZE) { |
5caea4ea ED |
2049 | ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
2050 | spin_lock_bh(&ilb->lock); | |
c25eb3bf | 2051 | sk = sk_nulls_head(&ilb->head); |
1da177e4 LT |
2052 | goto get_sk; |
2053 | } | |
2054 | cur = NULL; | |
2055 | out: | |
2056 | return cur; | |
2057 | } | |
2058 | ||
2059 | static void *listening_get_idx(struct seq_file *seq, loff_t *pos) | |
2060 | { | |
a8b690f9 TH |
2061 | struct tcp_iter_state *st = seq->private; |
2062 | void *rc; | |
2063 | ||
2064 | st->bucket = 0; | |
2065 | st->offset = 0; | |
2066 | rc = listening_get_next(seq, NULL); | |
1da177e4 LT |
2067 | |
2068 | while (rc && *pos) { | |
2069 | rc = listening_get_next(seq, rc); | |
2070 | --*pos; | |
2071 | } | |
2072 | return rc; | |
2073 | } | |
2074 | ||
6eac5604 AK |
2075 | static inline int empty_bucket(struct tcp_iter_state *st) |
2076 | { | |
3ab5aee7 ED |
2077 | return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain) && |
2078 | hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].twchain); | |
6eac5604 AK |
2079 | } |
2080 | ||
a8b690f9 TH |
2081 | /* |
2082 | * Get first established socket starting from bucket given in st->bucket. | |
2083 | * If st->bucket is zero, the very first socket in the hash is returned. | |
2084 | */ | |
1da177e4 LT |
2085 | static void *established_get_first(struct seq_file *seq) |
2086 | { | |
5799de0b | 2087 | struct tcp_iter_state *st = seq->private; |
a4146b1b | 2088 | struct net *net = seq_file_net(seq); |
1da177e4 LT |
2089 | void *rc = NULL; |
2090 | ||
a8b690f9 TH |
2091 | st->offset = 0; |
2092 | for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) { | |
1da177e4 | 2093 | struct sock *sk; |
3ab5aee7 | 2094 | struct hlist_nulls_node *node; |
8feaf0c0 | 2095 | struct inet_timewait_sock *tw; |
9db66bdc | 2096 | spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket); |
1da177e4 | 2097 | |
6eac5604 AK |
2098 | /* Lockless fast path for the common case of empty buckets */ |
2099 | if (empty_bucket(st)) | |
2100 | continue; | |
2101 | ||
9db66bdc | 2102 | spin_lock_bh(lock); |
3ab5aee7 | 2103 | sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) { |
f40c8174 | 2104 | if (sk->sk_family != st->family || |
878628fb | 2105 | !net_eq(sock_net(sk), net)) { |
1da177e4 LT |
2106 | continue; |
2107 | } | |
2108 | rc = sk; | |
2109 | goto out; | |
2110 | } | |
2111 | st->state = TCP_SEQ_STATE_TIME_WAIT; | |
8feaf0c0 | 2112 | inet_twsk_for_each(tw, node, |
dbca9b27 | 2113 | &tcp_hashinfo.ehash[st->bucket].twchain) { |
28518fc1 | 2114 | if (tw->tw_family != st->family || |
878628fb | 2115 | !net_eq(twsk_net(tw), net)) { |
1da177e4 LT |
2116 | continue; |
2117 | } | |
2118 | rc = tw; | |
2119 | goto out; | |
2120 | } | |
9db66bdc | 2121 | spin_unlock_bh(lock); |
1da177e4 LT |
2122 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2123 | } | |
2124 | out: | |
2125 | return rc; | |
2126 | } | |
2127 | ||
2128 | static void *established_get_next(struct seq_file *seq, void *cur) | |
2129 | { | |
2130 | struct sock *sk = cur; | |
8feaf0c0 | 2131 | struct inet_timewait_sock *tw; |
3ab5aee7 | 2132 | struct hlist_nulls_node *node; |
5799de0b | 2133 | struct tcp_iter_state *st = seq->private; |
a4146b1b | 2134 | struct net *net = seq_file_net(seq); |
1da177e4 LT |
2135 | |
2136 | ++st->num; | |
a8b690f9 | 2137 | ++st->offset; |
1da177e4 LT |
2138 | |
2139 | if (st->state == TCP_SEQ_STATE_TIME_WAIT) { | |
2140 | tw = cur; | |
2141 | tw = tw_next(tw); | |
2142 | get_tw: | |
878628fb | 2143 | while (tw && (tw->tw_family != st->family || !net_eq(twsk_net(tw), net))) { |
1da177e4 LT |
2144 | tw = tw_next(tw); |
2145 | } | |
2146 | if (tw) { | |
2147 | cur = tw; | |
2148 | goto out; | |
2149 | } | |
9db66bdc | 2150 | spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); |
1da177e4 LT |
2151 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2152 | ||
6eac5604 | 2153 | /* Look for next non empty bucket */ |
a8b690f9 | 2154 | st->offset = 0; |
f373b53b | 2155 | while (++st->bucket <= tcp_hashinfo.ehash_mask && |
6eac5604 AK |
2156 | empty_bucket(st)) |
2157 | ; | |
f373b53b | 2158 | if (st->bucket > tcp_hashinfo.ehash_mask) |
6eac5604 AK |
2159 | return NULL; |
2160 | ||
9db66bdc | 2161 | spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); |
3ab5aee7 | 2162 | sk = sk_nulls_head(&tcp_hashinfo.ehash[st->bucket].chain); |
1da177e4 | 2163 | } else |
3ab5aee7 | 2164 | sk = sk_nulls_next(sk); |
1da177e4 | 2165 | |
3ab5aee7 | 2166 | sk_nulls_for_each_from(sk, node) { |
878628fb | 2167 | if (sk->sk_family == st->family && net_eq(sock_net(sk), net)) |
1da177e4 LT |
2168 | goto found; |
2169 | } | |
2170 | ||
2171 | st->state = TCP_SEQ_STATE_TIME_WAIT; | |
dbca9b27 | 2172 | tw = tw_head(&tcp_hashinfo.ehash[st->bucket].twchain); |
1da177e4 LT |
2173 | goto get_tw; |
2174 | found: | |
2175 | cur = sk; | |
2176 | out: | |
2177 | return cur; | |
2178 | } | |
2179 | ||
2180 | static void *established_get_idx(struct seq_file *seq, loff_t pos) | |
2181 | { | |
a8b690f9 TH |
2182 | struct tcp_iter_state *st = seq->private; |
2183 | void *rc; | |
2184 | ||
2185 | st->bucket = 0; | |
2186 | rc = established_get_first(seq); | |
1da177e4 LT |
2187 | |
2188 | while (rc && pos) { | |
2189 | rc = established_get_next(seq, rc); | |
2190 | --pos; | |
7174259e | 2191 | } |
1da177e4 LT |
2192 | return rc; |
2193 | } | |
2194 | ||
2195 | static void *tcp_get_idx(struct seq_file *seq, loff_t pos) | |
2196 | { | |
2197 | void *rc; | |
5799de0b | 2198 | struct tcp_iter_state *st = seq->private; |
1da177e4 | 2199 | |
1da177e4 LT |
2200 | st->state = TCP_SEQ_STATE_LISTENING; |
2201 | rc = listening_get_idx(seq, &pos); | |
2202 | ||
2203 | if (!rc) { | |
1da177e4 LT |
2204 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2205 | rc = established_get_idx(seq, pos); | |
2206 | } | |
2207 | ||
2208 | return rc; | |
2209 | } | |
2210 | ||
a8b690f9 TH |
2211 | static void *tcp_seek_last_pos(struct seq_file *seq) |
2212 | { | |
2213 | struct tcp_iter_state *st = seq->private; | |
2214 | int offset = st->offset; | |
2215 | int orig_num = st->num; | |
2216 | void *rc = NULL; | |
2217 | ||
2218 | switch (st->state) { | |
2219 | case TCP_SEQ_STATE_OPENREQ: | |
2220 | case TCP_SEQ_STATE_LISTENING: | |
2221 | if (st->bucket >= INET_LHTABLE_SIZE) | |
2222 | break; | |
2223 | st->state = TCP_SEQ_STATE_LISTENING; | |
2224 | rc = listening_get_next(seq, NULL); | |
2225 | while (offset-- && rc) | |
2226 | rc = listening_get_next(seq, rc); | |
2227 | if (rc) | |
2228 | break; | |
2229 | st->bucket = 0; | |
2230 | /* Fallthrough */ | |
2231 | case TCP_SEQ_STATE_ESTABLISHED: | |
2232 | case TCP_SEQ_STATE_TIME_WAIT: | |
2233 | st->state = TCP_SEQ_STATE_ESTABLISHED; | |
2234 | if (st->bucket > tcp_hashinfo.ehash_mask) | |
2235 | break; | |
2236 | rc = established_get_first(seq); | |
2237 | while (offset-- && rc) | |
2238 | rc = established_get_next(seq, rc); | |
2239 | } | |
2240 | ||
2241 | st->num = orig_num; | |
2242 | ||
2243 | return rc; | |
2244 | } | |
2245 | ||
1da177e4 LT |
2246 | static void *tcp_seq_start(struct seq_file *seq, loff_t *pos) |
2247 | { | |
5799de0b | 2248 | struct tcp_iter_state *st = seq->private; |
a8b690f9 TH |
2249 | void *rc; |
2250 | ||
2251 | if (*pos && *pos == st->last_pos) { | |
2252 | rc = tcp_seek_last_pos(seq); | |
2253 | if (rc) | |
2254 | goto out; | |
2255 | } | |
2256 | ||
1da177e4 LT |
2257 | st->state = TCP_SEQ_STATE_LISTENING; |
2258 | st->num = 0; | |
a8b690f9 TH |
2259 | st->bucket = 0; |
2260 | st->offset = 0; | |
2261 | rc = *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
2262 | ||
2263 | out: | |
2264 | st->last_pos = *pos; | |
2265 | return rc; | |
1da177e4 LT |
2266 | } |
2267 | ||
2268 | static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2269 | { | |
a8b690f9 | 2270 | struct tcp_iter_state *st = seq->private; |
1da177e4 | 2271 | void *rc = NULL; |
1da177e4 LT |
2272 | |
2273 | if (v == SEQ_START_TOKEN) { | |
2274 | rc = tcp_get_idx(seq, 0); | |
2275 | goto out; | |
2276 | } | |
1da177e4 LT |
2277 | |
2278 | switch (st->state) { | |
2279 | case TCP_SEQ_STATE_OPENREQ: | |
2280 | case TCP_SEQ_STATE_LISTENING: | |
2281 | rc = listening_get_next(seq, v); | |
2282 | if (!rc) { | |
1da177e4 | 2283 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
a8b690f9 TH |
2284 | st->bucket = 0; |
2285 | st->offset = 0; | |
1da177e4 LT |
2286 | rc = established_get_first(seq); |
2287 | } | |
2288 | break; | |
2289 | case TCP_SEQ_STATE_ESTABLISHED: | |
2290 | case TCP_SEQ_STATE_TIME_WAIT: | |
2291 | rc = established_get_next(seq, v); | |
2292 | break; | |
2293 | } | |
2294 | out: | |
2295 | ++*pos; | |
a8b690f9 | 2296 | st->last_pos = *pos; |
1da177e4 LT |
2297 | return rc; |
2298 | } | |
2299 | ||
2300 | static void tcp_seq_stop(struct seq_file *seq, void *v) | |
2301 | { | |
5799de0b | 2302 | struct tcp_iter_state *st = seq->private; |
1da177e4 LT |
2303 | |
2304 | switch (st->state) { | |
2305 | case TCP_SEQ_STATE_OPENREQ: | |
2306 | if (v) { | |
463c84b9 ACM |
2307 | struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk); |
2308 | read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); | |
1da177e4 LT |
2309 | } |
2310 | case TCP_SEQ_STATE_LISTENING: | |
2311 | if (v != SEQ_START_TOKEN) | |
5caea4ea | 2312 | spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock); |
1da177e4 LT |
2313 | break; |
2314 | case TCP_SEQ_STATE_TIME_WAIT: | |
2315 | case TCP_SEQ_STATE_ESTABLISHED: | |
2316 | if (v) | |
9db66bdc | 2317 | spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); |
1da177e4 LT |
2318 | break; |
2319 | } | |
2320 | } | |
2321 | ||
2322 | static int tcp_seq_open(struct inode *inode, struct file *file) | |
2323 | { | |
2324 | struct tcp_seq_afinfo *afinfo = PDE(inode)->data; | |
1da177e4 | 2325 | struct tcp_iter_state *s; |
52d6f3f1 | 2326 | int err; |
1da177e4 | 2327 | |
52d6f3f1 DL |
2328 | err = seq_open_net(inode, file, &afinfo->seq_ops, |
2329 | sizeof(struct tcp_iter_state)); | |
2330 | if (err < 0) | |
2331 | return err; | |
f40c8174 | 2332 | |
52d6f3f1 | 2333 | s = ((struct seq_file *)file->private_data)->private; |
1da177e4 | 2334 | s->family = afinfo->family; |
a8b690f9 | 2335 | s->last_pos = 0; |
f40c8174 DL |
2336 | return 0; |
2337 | } | |
2338 | ||
6f8b13bc | 2339 | int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo) |
1da177e4 LT |
2340 | { |
2341 | int rc = 0; | |
2342 | struct proc_dir_entry *p; | |
2343 | ||
68fcadd1 DL |
2344 | afinfo->seq_fops.open = tcp_seq_open; |
2345 | afinfo->seq_fops.read = seq_read; | |
2346 | afinfo->seq_fops.llseek = seq_lseek; | |
2347 | afinfo->seq_fops.release = seq_release_net; | |
7174259e | 2348 | |
9427c4b3 DL |
2349 | afinfo->seq_ops.start = tcp_seq_start; |
2350 | afinfo->seq_ops.next = tcp_seq_next; | |
2351 | afinfo->seq_ops.stop = tcp_seq_stop; | |
2352 | ||
84841c3c DL |
2353 | p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, |
2354 | &afinfo->seq_fops, afinfo); | |
2355 | if (!p) | |
1da177e4 LT |
2356 | rc = -ENOMEM; |
2357 | return rc; | |
2358 | } | |
4bc2f18b | 2359 | EXPORT_SYMBOL(tcp_proc_register); |
1da177e4 | 2360 | |
6f8b13bc | 2361 | void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo) |
1da177e4 | 2362 | { |
6f8b13bc | 2363 | proc_net_remove(net, afinfo->name); |
1da177e4 | 2364 | } |
4bc2f18b | 2365 | EXPORT_SYMBOL(tcp_proc_unregister); |
1da177e4 | 2366 | |
60236fdd | 2367 | static void get_openreq4(struct sock *sk, struct request_sock *req, |
5e659e4c | 2368 | struct seq_file *f, int i, int uid, int *len) |
1da177e4 | 2369 | { |
2e6599cb | 2370 | const struct inet_request_sock *ireq = inet_rsk(req); |
1da177e4 LT |
2371 | int ttd = req->expires - jiffies; |
2372 | ||
5e659e4c PE |
2373 | seq_printf(f, "%4d: %08X:%04X %08X:%04X" |
2374 | " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p%n", | |
1da177e4 | 2375 | i, |
2e6599cb | 2376 | ireq->loc_addr, |
c720c7e8 | 2377 | ntohs(inet_sk(sk)->inet_sport), |
2e6599cb ACM |
2378 | ireq->rmt_addr, |
2379 | ntohs(ireq->rmt_port), | |
1da177e4 LT |
2380 | TCP_SYN_RECV, |
2381 | 0, 0, /* could print option size, but that is af dependent. */ | |
2382 | 1, /* timers active (only the expire timer) */ | |
2383 | jiffies_to_clock_t(ttd), | |
2384 | req->retrans, | |
2385 | uid, | |
2386 | 0, /* non standard timer */ | |
2387 | 0, /* open_requests have no inode */ | |
2388 | atomic_read(&sk->sk_refcnt), | |
5e659e4c PE |
2389 | req, |
2390 | len); | |
1da177e4 LT |
2391 | } |
2392 | ||
5e659e4c | 2393 | static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len) |
1da177e4 LT |
2394 | { |
2395 | int timer_active; | |
2396 | unsigned long timer_expires; | |
cf4c6bf8 IJ |
2397 | struct tcp_sock *tp = tcp_sk(sk); |
2398 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
2399 | struct inet_sock *inet = inet_sk(sk); | |
c720c7e8 ED |
2400 | __be32 dest = inet->inet_daddr; |
2401 | __be32 src = inet->inet_rcv_saddr; | |
2402 | __u16 destp = ntohs(inet->inet_dport); | |
2403 | __u16 srcp = ntohs(inet->inet_sport); | |
49d09007 | 2404 | int rx_queue; |
1da177e4 | 2405 | |
463c84b9 | 2406 | if (icsk->icsk_pending == ICSK_TIME_RETRANS) { |
1da177e4 | 2407 | timer_active = 1; |
463c84b9 ACM |
2408 | timer_expires = icsk->icsk_timeout; |
2409 | } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { | |
1da177e4 | 2410 | timer_active = 4; |
463c84b9 | 2411 | timer_expires = icsk->icsk_timeout; |
cf4c6bf8 | 2412 | } else if (timer_pending(&sk->sk_timer)) { |
1da177e4 | 2413 | timer_active = 2; |
cf4c6bf8 | 2414 | timer_expires = sk->sk_timer.expires; |
1da177e4 LT |
2415 | } else { |
2416 | timer_active = 0; | |
2417 | timer_expires = jiffies; | |
2418 | } | |
2419 | ||
49d09007 ED |
2420 | if (sk->sk_state == TCP_LISTEN) |
2421 | rx_queue = sk->sk_ack_backlog; | |
2422 | else | |
2423 | /* | |
2424 | * because we dont lock socket, we might find a transient negative value | |
2425 | */ | |
2426 | rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0); | |
2427 | ||
5e659e4c | 2428 | seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX " |
7be87351 | 2429 | "%08X %5d %8d %lu %d %p %lu %lu %u %u %d%n", |
cf4c6bf8 | 2430 | i, src, srcp, dest, destp, sk->sk_state, |
47da8ee6 | 2431 | tp->write_seq - tp->snd_una, |
49d09007 | 2432 | rx_queue, |
1da177e4 LT |
2433 | timer_active, |
2434 | jiffies_to_clock_t(timer_expires - jiffies), | |
463c84b9 | 2435 | icsk->icsk_retransmits, |
cf4c6bf8 | 2436 | sock_i_uid(sk), |
6687e988 | 2437 | icsk->icsk_probes_out, |
cf4c6bf8 IJ |
2438 | sock_i_ino(sk), |
2439 | atomic_read(&sk->sk_refcnt), sk, | |
7be87351 SH |
2440 | jiffies_to_clock_t(icsk->icsk_rto), |
2441 | jiffies_to_clock_t(icsk->icsk_ack.ato), | |
463c84b9 | 2442 | (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong, |
1da177e4 | 2443 | tp->snd_cwnd, |
0b6a05c1 | 2444 | tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh, |
5e659e4c | 2445 | len); |
1da177e4 LT |
2446 | } |
2447 | ||
7174259e | 2448 | static void get_timewait4_sock(struct inet_timewait_sock *tw, |
5e659e4c | 2449 | struct seq_file *f, int i, int *len) |
1da177e4 | 2450 | { |
23f33c2d | 2451 | __be32 dest, src; |
1da177e4 LT |
2452 | __u16 destp, srcp; |
2453 | int ttd = tw->tw_ttd - jiffies; | |
2454 | ||
2455 | if (ttd < 0) | |
2456 | ttd = 0; | |
2457 | ||
2458 | dest = tw->tw_daddr; | |
2459 | src = tw->tw_rcv_saddr; | |
2460 | destp = ntohs(tw->tw_dport); | |
2461 | srcp = ntohs(tw->tw_sport); | |
2462 | ||
5e659e4c PE |
2463 | seq_printf(f, "%4d: %08X:%04X %08X:%04X" |
2464 | " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p%n", | |
1da177e4 LT |
2465 | i, src, srcp, dest, destp, tw->tw_substate, 0, 0, |
2466 | 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0, | |
5e659e4c | 2467 | atomic_read(&tw->tw_refcnt), tw, len); |
1da177e4 LT |
2468 | } |
2469 | ||
2470 | #define TMPSZ 150 | |
2471 | ||
2472 | static int tcp4_seq_show(struct seq_file *seq, void *v) | |
2473 | { | |
5799de0b | 2474 | struct tcp_iter_state *st; |
5e659e4c | 2475 | int len; |
1da177e4 LT |
2476 | |
2477 | if (v == SEQ_START_TOKEN) { | |
2478 | seq_printf(seq, "%-*s\n", TMPSZ - 1, | |
2479 | " sl local_address rem_address st tx_queue " | |
2480 | "rx_queue tr tm->when retrnsmt uid timeout " | |
2481 | "inode"); | |
2482 | goto out; | |
2483 | } | |
2484 | st = seq->private; | |
2485 | ||
2486 | switch (st->state) { | |
2487 | case TCP_SEQ_STATE_LISTENING: | |
2488 | case TCP_SEQ_STATE_ESTABLISHED: | |
5e659e4c | 2489 | get_tcp4_sock(v, seq, st->num, &len); |
1da177e4 LT |
2490 | break; |
2491 | case TCP_SEQ_STATE_OPENREQ: | |
5e659e4c | 2492 | get_openreq4(st->syn_wait_sk, v, seq, st->num, st->uid, &len); |
1da177e4 LT |
2493 | break; |
2494 | case TCP_SEQ_STATE_TIME_WAIT: | |
5e659e4c | 2495 | get_timewait4_sock(v, seq, st->num, &len); |
1da177e4 LT |
2496 | break; |
2497 | } | |
5e659e4c | 2498 | seq_printf(seq, "%*s\n", TMPSZ - 1 - len, ""); |
1da177e4 LT |
2499 | out: |
2500 | return 0; | |
2501 | } | |
2502 | ||
1da177e4 | 2503 | static struct tcp_seq_afinfo tcp4_seq_afinfo = { |
1da177e4 LT |
2504 | .name = "tcp", |
2505 | .family = AF_INET, | |
5f4472c5 DL |
2506 | .seq_fops = { |
2507 | .owner = THIS_MODULE, | |
2508 | }, | |
9427c4b3 DL |
2509 | .seq_ops = { |
2510 | .show = tcp4_seq_show, | |
2511 | }, | |
1da177e4 LT |
2512 | }; |
2513 | ||
2c8c1e72 | 2514 | static int __net_init tcp4_proc_init_net(struct net *net) |
757764f6 PE |
2515 | { |
2516 | return tcp_proc_register(net, &tcp4_seq_afinfo); | |
2517 | } | |
2518 | ||
2c8c1e72 | 2519 | static void __net_exit tcp4_proc_exit_net(struct net *net) |
757764f6 PE |
2520 | { |
2521 | tcp_proc_unregister(net, &tcp4_seq_afinfo); | |
2522 | } | |
2523 | ||
2524 | static struct pernet_operations tcp4_net_ops = { | |
2525 | .init = tcp4_proc_init_net, | |
2526 | .exit = tcp4_proc_exit_net, | |
2527 | }; | |
2528 | ||
1da177e4 LT |
2529 | int __init tcp4_proc_init(void) |
2530 | { | |
757764f6 | 2531 | return register_pernet_subsys(&tcp4_net_ops); |
1da177e4 LT |
2532 | } |
2533 | ||
2534 | void tcp4_proc_exit(void) | |
2535 | { | |
757764f6 | 2536 | unregister_pernet_subsys(&tcp4_net_ops); |
1da177e4 LT |
2537 | } |
2538 | #endif /* CONFIG_PROC_FS */ | |
2539 | ||
bf296b12 HX |
2540 | struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb) |
2541 | { | |
b71d1d42 | 2542 | const struct iphdr *iph = skb_gro_network_header(skb); |
bf296b12 HX |
2543 | |
2544 | switch (skb->ip_summed) { | |
2545 | case CHECKSUM_COMPLETE: | |
86911732 | 2546 | if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr, |
bf296b12 HX |
2547 | skb->csum)) { |
2548 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
2549 | break; | |
2550 | } | |
2551 | ||
2552 | /* fall through */ | |
2553 | case CHECKSUM_NONE: | |
2554 | NAPI_GRO_CB(skb)->flush = 1; | |
2555 | return NULL; | |
2556 | } | |
2557 | ||
2558 | return tcp_gro_receive(head, skb); | |
2559 | } | |
bf296b12 HX |
2560 | |
2561 | int tcp4_gro_complete(struct sk_buff *skb) | |
2562 | { | |
b71d1d42 | 2563 | const struct iphdr *iph = ip_hdr(skb); |
bf296b12 HX |
2564 | struct tcphdr *th = tcp_hdr(skb); |
2565 | ||
2566 | th->check = ~tcp_v4_check(skb->len - skb_transport_offset(skb), | |
2567 | iph->saddr, iph->daddr, 0); | |
2568 | skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; | |
2569 | ||
2570 | return tcp_gro_complete(skb); | |
2571 | } | |
bf296b12 | 2572 | |
1da177e4 LT |
2573 | struct proto tcp_prot = { |
2574 | .name = "TCP", | |
2575 | .owner = THIS_MODULE, | |
2576 | .close = tcp_close, | |
2577 | .connect = tcp_v4_connect, | |
2578 | .disconnect = tcp_disconnect, | |
463c84b9 | 2579 | .accept = inet_csk_accept, |
1da177e4 LT |
2580 | .ioctl = tcp_ioctl, |
2581 | .init = tcp_v4_init_sock, | |
2582 | .destroy = tcp_v4_destroy_sock, | |
2583 | .shutdown = tcp_shutdown, | |
2584 | .setsockopt = tcp_setsockopt, | |
2585 | .getsockopt = tcp_getsockopt, | |
1da177e4 | 2586 | .recvmsg = tcp_recvmsg, |
7ba42910 CG |
2587 | .sendmsg = tcp_sendmsg, |
2588 | .sendpage = tcp_sendpage, | |
1da177e4 | 2589 | .backlog_rcv = tcp_v4_do_rcv, |
ab1e0a13 ACM |
2590 | .hash = inet_hash, |
2591 | .unhash = inet_unhash, | |
2592 | .get_port = inet_csk_get_port, | |
1da177e4 LT |
2593 | .enter_memory_pressure = tcp_enter_memory_pressure, |
2594 | .sockets_allocated = &tcp_sockets_allocated, | |
0a5578cf | 2595 | .orphan_count = &tcp_orphan_count, |
1da177e4 LT |
2596 | .memory_allocated = &tcp_memory_allocated, |
2597 | .memory_pressure = &tcp_memory_pressure, | |
2598 | .sysctl_mem = sysctl_tcp_mem, | |
2599 | .sysctl_wmem = sysctl_tcp_wmem, | |
2600 | .sysctl_rmem = sysctl_tcp_rmem, | |
2601 | .max_header = MAX_TCP_HEADER, | |
2602 | .obj_size = sizeof(struct tcp_sock), | |
3ab5aee7 | 2603 | .slab_flags = SLAB_DESTROY_BY_RCU, |
6d6ee43e | 2604 | .twsk_prot = &tcp_timewait_sock_ops, |
60236fdd | 2605 | .rsk_prot = &tcp_request_sock_ops, |
39d8cda7 | 2606 | .h.hashinfo = &tcp_hashinfo, |
7ba42910 | 2607 | .no_autobind = true, |
543d9cfe ACM |
2608 | #ifdef CONFIG_COMPAT |
2609 | .compat_setsockopt = compat_tcp_setsockopt, | |
2610 | .compat_getsockopt = compat_tcp_getsockopt, | |
2611 | #endif | |
1da177e4 | 2612 | }; |
4bc2f18b | 2613 | EXPORT_SYMBOL(tcp_prot); |
1da177e4 | 2614 | |
046ee902 DL |
2615 | |
2616 | static int __net_init tcp_sk_init(struct net *net) | |
2617 | { | |
2618 | return inet_ctl_sock_create(&net->ipv4.tcp_sock, | |
2619 | PF_INET, SOCK_RAW, IPPROTO_TCP, net); | |
2620 | } | |
2621 | ||
2622 | static void __net_exit tcp_sk_exit(struct net *net) | |
2623 | { | |
2624 | inet_ctl_sock_destroy(net->ipv4.tcp_sock); | |
b099ce26 EB |
2625 | } |
2626 | ||
2627 | static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list) | |
2628 | { | |
2629 | inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET); | |
046ee902 DL |
2630 | } |
2631 | ||
2632 | static struct pernet_operations __net_initdata tcp_sk_ops = { | |
b099ce26 EB |
2633 | .init = tcp_sk_init, |
2634 | .exit = tcp_sk_exit, | |
2635 | .exit_batch = tcp_sk_exit_batch, | |
046ee902 DL |
2636 | }; |
2637 | ||
9b0f976f | 2638 | void __init tcp_v4_init(void) |
1da177e4 | 2639 | { |
5caea4ea | 2640 | inet_hashinfo_init(&tcp_hashinfo); |
6a1b3054 | 2641 | if (register_pernet_subsys(&tcp_sk_ops)) |
1da177e4 | 2642 | panic("Failed to create the TCP control socket.\n"); |
1da177e4 | 2643 | } |