Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | |
3 | * operating system. INET is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * Implementation of the Transmission Control Protocol(TCP). | |
7 | * | |
1da177e4 LT |
8 | * IPv4 specific functions |
9 | * | |
10 | * | |
11 | * code split from: | |
12 | * linux/ipv4/tcp.c | |
13 | * linux/ipv4/tcp_input.c | |
14 | * linux/ipv4/tcp_output.c | |
15 | * | |
16 | * See tcp.c for author information | |
17 | * | |
18 | * This program is free software; you can redistribute it and/or | |
19 | * modify it under the terms of the GNU General Public License | |
20 | * as published by the Free Software Foundation; either version | |
21 | * 2 of the License, or (at your option) any later version. | |
22 | */ | |
23 | ||
24 | /* | |
25 | * Changes: | |
26 | * David S. Miller : New socket lookup architecture. | |
27 | * This code is dedicated to John Dyson. | |
28 | * David S. Miller : Change semantics of established hash, | |
29 | * half is devoted to TIME_WAIT sockets | |
30 | * and the rest go in the other half. | |
31 | * Andi Kleen : Add support for syncookies and fixed | |
32 | * some bugs: ip options weren't passed to | |
33 | * the TCP layer, missed a check for an | |
34 | * ACK bit. | |
35 | * Andi Kleen : Implemented fast path mtu discovery. | |
36 | * Fixed many serious bugs in the | |
60236fdd | 37 | * request_sock handling and moved |
1da177e4 LT |
38 | * most of it into the af independent code. |
39 | * Added tail drop and some other bugfixes. | |
caa20d9a | 40 | * Added new listen semantics. |
1da177e4 LT |
41 | * Mike McLagan : Routing by source |
42 | * Juan Jose Ciarlante: ip_dynaddr bits | |
43 | * Andi Kleen: various fixes. | |
44 | * Vitaly E. Lavrov : Transparent proxy revived after year | |
45 | * coma. | |
46 | * Andi Kleen : Fix new listen. | |
47 | * Andi Kleen : Fix accept error reporting. | |
48 | * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which | |
49 | * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind | |
50 | * a single port at the same time. | |
51 | */ | |
52 | ||
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 | { | |
149 | struct inet_sock *inet = inet_sk(sk); | |
150 | struct tcp_sock *tp = tcp_sk(sk); | |
151 | struct sockaddr_in *usin = (struct sockaddr_in *)uaddr; | |
dca8b089 | 152 | __be16 orig_sport, orig_dport; |
1da177e4 | 153 | struct rtable *rt; |
bada8adc | 154 | __be32 daddr, nexthop; |
1da177e4 LT |
155 | int err; |
156 | ||
157 | if (addr_len < sizeof(struct sockaddr_in)) | |
158 | return -EINVAL; | |
159 | ||
160 | if (usin->sin_family != AF_INET) | |
161 | return -EAFNOSUPPORT; | |
162 | ||
163 | nexthop = daddr = usin->sin_addr.s_addr; | |
164 | if (inet->opt && inet->opt->srr) { | |
165 | if (!daddr) | |
166 | return -EINVAL; | |
167 | nexthop = inet->opt->faddr; | |
168 | } | |
169 | ||
dca8b089 DM |
170 | orig_sport = inet->inet_sport; |
171 | orig_dport = usin->sin_port; | |
b23dd4fe DM |
172 | rt = ip_route_connect(nexthop, inet->inet_saddr, |
173 | RT_CONN_FLAGS(sk), sk->sk_bound_dev_if, | |
174 | IPPROTO_TCP, | |
175 | orig_sport, orig_dport, sk, true); | |
176 | if (IS_ERR(rt)) { | |
177 | err = PTR_ERR(rt); | |
178 | if (err == -ENETUNREACH) | |
7c73a6fa | 179 | IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
b23dd4fe | 180 | return err; |
584bdf8c | 181 | } |
1da177e4 LT |
182 | |
183 | if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { | |
184 | ip_rt_put(rt); | |
185 | return -ENETUNREACH; | |
186 | } | |
187 | ||
188 | if (!inet->opt || !inet->opt->srr) | |
189 | daddr = rt->rt_dst; | |
190 | ||
c720c7e8 ED |
191 | if (!inet->inet_saddr) |
192 | inet->inet_saddr = rt->rt_src; | |
193 | inet->inet_rcv_saddr = inet->inet_saddr; | |
1da177e4 | 194 | |
c720c7e8 | 195 | if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) { |
1da177e4 LT |
196 | /* Reset inherited state */ |
197 | tp->rx_opt.ts_recent = 0; | |
198 | tp->rx_opt.ts_recent_stamp = 0; | |
199 | tp->write_seq = 0; | |
200 | } | |
201 | ||
295ff7ed | 202 | if (tcp_death_row.sysctl_tw_recycle && |
1da177e4 LT |
203 | !tp->rx_opt.ts_recent_stamp && rt->rt_dst == daddr) { |
204 | struct inet_peer *peer = rt_get_peer(rt); | |
7174259e ACM |
205 | /* |
206 | * VJ's idea. We save last timestamp seen from | |
207 | * the destination in peer table, when entering state | |
208 | * TIME-WAIT * and initialize rx_opt.ts_recent from it, | |
209 | * when trying new connection. | |
1da177e4 | 210 | */ |
317fe0e6 ED |
211 | if (peer) { |
212 | inet_peer_refcheck(peer); | |
213 | if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) { | |
214 | tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp; | |
215 | tp->rx_opt.ts_recent = peer->tcp_ts; | |
216 | } | |
1da177e4 LT |
217 | } |
218 | } | |
219 | ||
c720c7e8 ED |
220 | inet->inet_dport = usin->sin_port; |
221 | inet->inet_daddr = daddr; | |
1da177e4 | 222 | |
d83d8461 | 223 | inet_csk(sk)->icsk_ext_hdr_len = 0; |
1da177e4 | 224 | if (inet->opt) |
d83d8461 | 225 | inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen; |
1da177e4 | 226 | |
bee7ca9e | 227 | tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT; |
1da177e4 LT |
228 | |
229 | /* Socket identity is still unknown (sport may be zero). | |
230 | * However we set state to SYN-SENT and not releasing socket | |
231 | * lock select source port, enter ourselves into the hash tables and | |
232 | * complete initialization after this. | |
233 | */ | |
234 | tcp_set_state(sk, TCP_SYN_SENT); | |
a7f5e7f1 | 235 | err = inet_hash_connect(&tcp_death_row, sk); |
1da177e4 LT |
236 | if (err) |
237 | goto failure; | |
238 | ||
b23dd4fe DM |
239 | rt = ip_route_newports(rt, IPPROTO_TCP, |
240 | orig_sport, orig_dport, | |
241 | inet->inet_sport, inet->inet_dport, sk); | |
242 | if (IS_ERR(rt)) { | |
243 | err = PTR_ERR(rt); | |
244 | rt = NULL; | |
1da177e4 | 245 | goto failure; |
b23dd4fe | 246 | } |
1da177e4 | 247 | /* OK, now commit destination to socket. */ |
bcd76111 | 248 | sk->sk_gso_type = SKB_GSO_TCPV4; |
d8d1f30b | 249 | sk_setup_caps(sk, &rt->dst); |
1da177e4 LT |
250 | |
251 | if (!tp->write_seq) | |
c720c7e8 ED |
252 | tp->write_seq = secure_tcp_sequence_number(inet->inet_saddr, |
253 | inet->inet_daddr, | |
254 | inet->inet_sport, | |
1da177e4 LT |
255 | usin->sin_port); |
256 | ||
c720c7e8 | 257 | inet->inet_id = tp->write_seq ^ jiffies; |
1da177e4 LT |
258 | |
259 | err = tcp_connect(sk); | |
260 | rt = NULL; | |
261 | if (err) | |
262 | goto failure; | |
263 | ||
264 | return 0; | |
265 | ||
266 | failure: | |
7174259e ACM |
267 | /* |
268 | * This unhashes the socket and releases the local port, | |
269 | * if necessary. | |
270 | */ | |
1da177e4 LT |
271 | tcp_set_state(sk, TCP_CLOSE); |
272 | ip_rt_put(rt); | |
273 | sk->sk_route_caps = 0; | |
c720c7e8 | 274 | inet->inet_dport = 0; |
1da177e4 LT |
275 | return err; |
276 | } | |
4bc2f18b | 277 | EXPORT_SYMBOL(tcp_v4_connect); |
1da177e4 | 278 | |
1da177e4 LT |
279 | /* |
280 | * This routine does path mtu discovery as defined in RFC1191. | |
281 | */ | |
40efc6fa | 282 | static void do_pmtu_discovery(struct sock *sk, struct iphdr *iph, u32 mtu) |
1da177e4 LT |
283 | { |
284 | struct dst_entry *dst; | |
285 | struct inet_sock *inet = inet_sk(sk); | |
1da177e4 LT |
286 | |
287 | /* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs | |
288 | * send out by Linux are always <576bytes so they should go through | |
289 | * unfragmented). | |
290 | */ | |
291 | if (sk->sk_state == TCP_LISTEN) | |
292 | return; | |
293 | ||
294 | /* We don't check in the destentry if pmtu discovery is forbidden | |
295 | * on this route. We just assume that no packet_to_big packets | |
296 | * are send back when pmtu discovery is not active. | |
e905a9ed | 297 | * There is a small race when the user changes this flag in the |
1da177e4 LT |
298 | * route, but I think that's acceptable. |
299 | */ | |
300 | if ((dst = __sk_dst_check(sk, 0)) == NULL) | |
301 | return; | |
302 | ||
303 | dst->ops->update_pmtu(dst, mtu); | |
304 | ||
305 | /* Something is about to be wrong... Remember soft error | |
306 | * for the case, if this connection will not able to recover. | |
307 | */ | |
308 | if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst)) | |
309 | sk->sk_err_soft = EMSGSIZE; | |
310 | ||
311 | mtu = dst_mtu(dst); | |
312 | ||
313 | if (inet->pmtudisc != IP_PMTUDISC_DONT && | |
d83d8461 | 314 | inet_csk(sk)->icsk_pmtu_cookie > mtu) { |
1da177e4 LT |
315 | tcp_sync_mss(sk, mtu); |
316 | ||
317 | /* Resend the TCP packet because it's | |
318 | * clear that the old packet has been | |
319 | * dropped. This is the new "fast" path mtu | |
320 | * discovery. | |
321 | */ | |
322 | tcp_simple_retransmit(sk); | |
323 | } /* else let the usual retransmit timer handle it */ | |
324 | } | |
325 | ||
326 | /* | |
327 | * This routine is called by the ICMP module when it gets some | |
328 | * sort of error condition. If err < 0 then the socket should | |
329 | * be closed and the error returned to the user. If err > 0 | |
330 | * it's just the icmp type << 8 | icmp code. After adjustment | |
331 | * header points to the first 8 bytes of the tcp header. We need | |
332 | * to find the appropriate port. | |
333 | * | |
334 | * The locking strategy used here is very "optimistic". When | |
335 | * someone else accesses the socket the ICMP is just dropped | |
336 | * and for some paths there is no check at all. | |
337 | * A more general error queue to queue errors for later handling | |
338 | * is probably better. | |
339 | * | |
340 | */ | |
341 | ||
4d1a2d9e | 342 | void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) |
1da177e4 | 343 | { |
4d1a2d9e DL |
344 | struct iphdr *iph = (struct iphdr *)icmp_skb->data; |
345 | struct tcphdr *th = (struct tcphdr *)(icmp_skb->data + (iph->ihl << 2)); | |
f1ecd5d9 | 346 | struct inet_connection_sock *icsk; |
1da177e4 LT |
347 | struct tcp_sock *tp; |
348 | struct inet_sock *inet; | |
4d1a2d9e DL |
349 | const int type = icmp_hdr(icmp_skb)->type; |
350 | const int code = icmp_hdr(icmp_skb)->code; | |
1da177e4 | 351 | struct sock *sk; |
f1ecd5d9 | 352 | struct sk_buff *skb; |
1da177e4 | 353 | __u32 seq; |
f1ecd5d9 | 354 | __u32 remaining; |
1da177e4 | 355 | int err; |
4d1a2d9e | 356 | struct net *net = dev_net(icmp_skb->dev); |
1da177e4 | 357 | |
4d1a2d9e | 358 | if (icmp_skb->len < (iph->ihl << 2) + 8) { |
dcfc23ca | 359 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
360 | return; |
361 | } | |
362 | ||
fd54d716 | 363 | sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest, |
4d1a2d9e | 364 | iph->saddr, th->source, inet_iif(icmp_skb)); |
1da177e4 | 365 | if (!sk) { |
dcfc23ca | 366 | ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
1da177e4 LT |
367 | return; |
368 | } | |
369 | if (sk->sk_state == TCP_TIME_WAIT) { | |
9469c7b4 | 370 | inet_twsk_put(inet_twsk(sk)); |
1da177e4 LT |
371 | return; |
372 | } | |
373 | ||
374 | bh_lock_sock(sk); | |
375 | /* If too many ICMPs get dropped on busy | |
376 | * servers this needs to be solved differently. | |
377 | */ | |
378 | if (sock_owned_by_user(sk)) | |
de0744af | 379 | NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); |
1da177e4 LT |
380 | |
381 | if (sk->sk_state == TCP_CLOSE) | |
382 | goto out; | |
383 | ||
97e3ecd1 | 384 | if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { |
385 | NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP); | |
386 | goto out; | |
387 | } | |
388 | ||
f1ecd5d9 | 389 | icsk = inet_csk(sk); |
1da177e4 LT |
390 | tp = tcp_sk(sk); |
391 | seq = ntohl(th->seq); | |
392 | if (sk->sk_state != TCP_LISTEN && | |
393 | !between(seq, tp->snd_una, tp->snd_nxt)) { | |
de0744af | 394 | NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); |
1da177e4 LT |
395 | goto out; |
396 | } | |
397 | ||
398 | switch (type) { | |
399 | case ICMP_SOURCE_QUENCH: | |
400 | /* Just silently ignore these. */ | |
401 | goto out; | |
402 | case ICMP_PARAMETERPROB: | |
403 | err = EPROTO; | |
404 | break; | |
405 | case ICMP_DEST_UNREACH: | |
406 | if (code > NR_ICMP_UNREACH) | |
407 | goto out; | |
408 | ||
409 | if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ | |
410 | if (!sock_owned_by_user(sk)) | |
411 | do_pmtu_discovery(sk, iph, info); | |
412 | goto out; | |
413 | } | |
414 | ||
415 | err = icmp_err_convert[code].errno; | |
f1ecd5d9 DL |
416 | /* check if icmp_skb allows revert of backoff |
417 | * (see draft-zimmermann-tcp-lcd) */ | |
418 | if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH) | |
419 | break; | |
420 | if (seq != tp->snd_una || !icsk->icsk_retransmits || | |
421 | !icsk->icsk_backoff) | |
422 | break; | |
423 | ||
8f49c270 DM |
424 | if (sock_owned_by_user(sk)) |
425 | break; | |
426 | ||
f1ecd5d9 DL |
427 | icsk->icsk_backoff--; |
428 | inet_csk(sk)->icsk_rto = __tcp_set_rto(tp) << | |
429 | icsk->icsk_backoff; | |
430 | tcp_bound_rto(sk); | |
431 | ||
432 | skb = tcp_write_queue_head(sk); | |
433 | BUG_ON(!skb); | |
434 | ||
435 | remaining = icsk->icsk_rto - min(icsk->icsk_rto, | |
436 | tcp_time_stamp - TCP_SKB_CB(skb)->when); | |
437 | ||
438 | if (remaining) { | |
439 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, | |
440 | remaining, TCP_RTO_MAX); | |
f1ecd5d9 DL |
441 | } else { |
442 | /* RTO revert clocked out retransmission. | |
443 | * Will retransmit now */ | |
444 | tcp_retransmit_timer(sk); | |
445 | } | |
446 | ||
1da177e4 LT |
447 | break; |
448 | case ICMP_TIME_EXCEEDED: | |
449 | err = EHOSTUNREACH; | |
450 | break; | |
451 | default: | |
452 | goto out; | |
453 | } | |
454 | ||
455 | switch (sk->sk_state) { | |
60236fdd | 456 | struct request_sock *req, **prev; |
1da177e4 LT |
457 | case TCP_LISTEN: |
458 | if (sock_owned_by_user(sk)) | |
459 | goto out; | |
460 | ||
463c84b9 ACM |
461 | req = inet_csk_search_req(sk, &prev, th->dest, |
462 | iph->daddr, iph->saddr); | |
1da177e4 LT |
463 | if (!req) |
464 | goto out; | |
465 | ||
466 | /* ICMPs are not backlogged, hence we cannot get | |
467 | an established socket here. | |
468 | */ | |
547b792c | 469 | WARN_ON(req->sk); |
1da177e4 | 470 | |
2e6599cb | 471 | if (seq != tcp_rsk(req)->snt_isn) { |
de0744af | 472 | NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); |
1da177e4 LT |
473 | goto out; |
474 | } | |
475 | ||
476 | /* | |
477 | * Still in SYN_RECV, just remove it silently. | |
478 | * There is no good way to pass the error to the newly | |
479 | * created socket, and POSIX does not want network | |
480 | * errors returned from accept(). | |
481 | */ | |
463c84b9 | 482 | inet_csk_reqsk_queue_drop(sk, req, prev); |
1da177e4 LT |
483 | goto out; |
484 | ||
485 | case TCP_SYN_SENT: | |
486 | case TCP_SYN_RECV: /* Cannot happen. | |
487 | It can f.e. if SYNs crossed. | |
488 | */ | |
489 | if (!sock_owned_by_user(sk)) { | |
1da177e4 LT |
490 | sk->sk_err = err; |
491 | ||
492 | sk->sk_error_report(sk); | |
493 | ||
494 | tcp_done(sk); | |
495 | } else { | |
496 | sk->sk_err_soft = err; | |
497 | } | |
498 | goto out; | |
499 | } | |
500 | ||
501 | /* If we've already connected we will keep trying | |
502 | * until we time out, or the user gives up. | |
503 | * | |
504 | * rfc1122 4.2.3.9 allows to consider as hard errors | |
505 | * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, | |
506 | * but it is obsoleted by pmtu discovery). | |
507 | * | |
508 | * Note, that in modern internet, where routing is unreliable | |
509 | * and in each dark corner broken firewalls sit, sending random | |
510 | * errors ordered by their masters even this two messages finally lose | |
511 | * their original sense (even Linux sends invalid PORT_UNREACHs) | |
512 | * | |
513 | * Now we are in compliance with RFCs. | |
514 | * --ANK (980905) | |
515 | */ | |
516 | ||
517 | inet = inet_sk(sk); | |
518 | if (!sock_owned_by_user(sk) && inet->recverr) { | |
519 | sk->sk_err = err; | |
520 | sk->sk_error_report(sk); | |
521 | } else { /* Only an error on timeout */ | |
522 | sk->sk_err_soft = err; | |
523 | } | |
524 | ||
525 | out: | |
526 | bh_unlock_sock(sk); | |
527 | sock_put(sk); | |
528 | } | |
529 | ||
419f9f89 HX |
530 | static void __tcp_v4_send_check(struct sk_buff *skb, |
531 | __be32 saddr, __be32 daddr) | |
1da177e4 | 532 | { |
aa8223c7 | 533 | struct tcphdr *th = tcp_hdr(skb); |
1da177e4 | 534 | |
84fa7933 | 535 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
419f9f89 | 536 | th->check = ~tcp_v4_check(skb->len, saddr, daddr, 0); |
663ead3b | 537 | skb->csum_start = skb_transport_header(skb) - skb->head; |
ff1dcadb | 538 | skb->csum_offset = offsetof(struct tcphdr, check); |
1da177e4 | 539 | } else { |
419f9f89 | 540 | th->check = tcp_v4_check(skb->len, saddr, daddr, |
07f0757a | 541 | csum_partial(th, |
1da177e4 LT |
542 | th->doff << 2, |
543 | skb->csum)); | |
544 | } | |
545 | } | |
546 | ||
419f9f89 | 547 | /* This routine computes an IPv4 TCP checksum. */ |
bb296246 | 548 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb) |
419f9f89 HX |
549 | { |
550 | struct inet_sock *inet = inet_sk(sk); | |
551 | ||
552 | __tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr); | |
553 | } | |
4bc2f18b | 554 | EXPORT_SYMBOL(tcp_v4_send_check); |
419f9f89 | 555 | |
a430a43d HX |
556 | int tcp_v4_gso_send_check(struct sk_buff *skb) |
557 | { | |
eddc9ec5 | 558 | const struct iphdr *iph; |
a430a43d HX |
559 | struct tcphdr *th; |
560 | ||
561 | if (!pskb_may_pull(skb, sizeof(*th))) | |
562 | return -EINVAL; | |
563 | ||
eddc9ec5 | 564 | iph = ip_hdr(skb); |
aa8223c7 | 565 | th = tcp_hdr(skb); |
a430a43d HX |
566 | |
567 | th->check = 0; | |
84fa7933 | 568 | skb->ip_summed = CHECKSUM_PARTIAL; |
419f9f89 | 569 | __tcp_v4_send_check(skb, iph->saddr, iph->daddr); |
a430a43d HX |
570 | return 0; |
571 | } | |
572 | ||
1da177e4 LT |
573 | /* |
574 | * This routine will send an RST to the other tcp. | |
575 | * | |
576 | * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.) | |
577 | * for reset. | |
578 | * Answer: if a packet caused RST, it is not for a socket | |
579 | * existing in our system, if it is matched to a socket, | |
580 | * it is just duplicate segment or bug in other side's TCP. | |
581 | * So that we build reply only basing on parameters | |
582 | * arrived with segment. | |
583 | * Exception: precedence violation. We do not implement it in any case. | |
584 | */ | |
585 | ||
cfb6eeb4 | 586 | static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 587 | { |
aa8223c7 | 588 | struct tcphdr *th = tcp_hdr(skb); |
cfb6eeb4 YH |
589 | struct { |
590 | struct tcphdr th; | |
591 | #ifdef CONFIG_TCP_MD5SIG | |
714e85be | 592 | __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)]; |
cfb6eeb4 YH |
593 | #endif |
594 | } rep; | |
1da177e4 | 595 | struct ip_reply_arg arg; |
cfb6eeb4 YH |
596 | #ifdef CONFIG_TCP_MD5SIG |
597 | struct tcp_md5sig_key *key; | |
598 | #endif | |
a86b1e30 | 599 | struct net *net; |
1da177e4 LT |
600 | |
601 | /* Never send a reset in response to a reset. */ | |
602 | if (th->rst) | |
603 | return; | |
604 | ||
511c3f92 | 605 | if (skb_rtable(skb)->rt_type != RTN_LOCAL) |
1da177e4 LT |
606 | return; |
607 | ||
608 | /* Swap the send and the receive. */ | |
cfb6eeb4 YH |
609 | memset(&rep, 0, sizeof(rep)); |
610 | rep.th.dest = th->source; | |
611 | rep.th.source = th->dest; | |
612 | rep.th.doff = sizeof(struct tcphdr) / 4; | |
613 | rep.th.rst = 1; | |
1da177e4 LT |
614 | |
615 | if (th->ack) { | |
cfb6eeb4 | 616 | rep.th.seq = th->ack_seq; |
1da177e4 | 617 | } else { |
cfb6eeb4 YH |
618 | rep.th.ack = 1; |
619 | rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin + | |
620 | skb->len - (th->doff << 2)); | |
1da177e4 LT |
621 | } |
622 | ||
7174259e | 623 | memset(&arg, 0, sizeof(arg)); |
cfb6eeb4 YH |
624 | arg.iov[0].iov_base = (unsigned char *)&rep; |
625 | arg.iov[0].iov_len = sizeof(rep.th); | |
626 | ||
627 | #ifdef CONFIG_TCP_MD5SIG | |
eddc9ec5 | 628 | key = sk ? tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr) : NULL; |
cfb6eeb4 YH |
629 | if (key) { |
630 | rep.opt[0] = htonl((TCPOPT_NOP << 24) | | |
631 | (TCPOPT_NOP << 16) | | |
632 | (TCPOPT_MD5SIG << 8) | | |
633 | TCPOLEN_MD5SIG); | |
634 | /* Update length and the length the header thinks exists */ | |
635 | arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; | |
636 | rep.th.doff = arg.iov[0].iov_len / 4; | |
637 | ||
49a72dfb | 638 | tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1], |
78e645cb IJ |
639 | key, ip_hdr(skb)->saddr, |
640 | ip_hdr(skb)->daddr, &rep.th); | |
cfb6eeb4 YH |
641 | } |
642 | #endif | |
eddc9ec5 ACM |
643 | arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, |
644 | ip_hdr(skb)->saddr, /* XXX */ | |
52cd5750 | 645 | arg.iov[0].iov_len, IPPROTO_TCP, 0); |
1da177e4 | 646 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; |
88ef4a5a | 647 | arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0; |
1da177e4 | 648 | |
adf30907 | 649 | net = dev_net(skb_dst(skb)->dev); |
a86b1e30 | 650 | ip_send_reply(net->ipv4.tcp_sock, skb, |
7feb49c8 | 651 | &arg, arg.iov[0].iov_len); |
1da177e4 | 652 | |
63231bdd PE |
653 | TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS); |
654 | TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS); | |
1da177e4 LT |
655 | } |
656 | ||
657 | /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states | |
658 | outside socket context is ugly, certainly. What can I do? | |
659 | */ | |
660 | ||
9501f972 YH |
661 | static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack, |
662 | u32 win, u32 ts, int oif, | |
88ef4a5a KK |
663 | struct tcp_md5sig_key *key, |
664 | int reply_flags) | |
1da177e4 | 665 | { |
aa8223c7 | 666 | struct tcphdr *th = tcp_hdr(skb); |
1da177e4 LT |
667 | struct { |
668 | struct tcphdr th; | |
714e85be | 669 | __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2) |
cfb6eeb4 | 670 | #ifdef CONFIG_TCP_MD5SIG |
714e85be | 671 | + (TCPOLEN_MD5SIG_ALIGNED >> 2) |
cfb6eeb4 YH |
672 | #endif |
673 | ]; | |
1da177e4 LT |
674 | } rep; |
675 | struct ip_reply_arg arg; | |
adf30907 | 676 | struct net *net = dev_net(skb_dst(skb)->dev); |
1da177e4 LT |
677 | |
678 | memset(&rep.th, 0, sizeof(struct tcphdr)); | |
7174259e | 679 | memset(&arg, 0, sizeof(arg)); |
1da177e4 LT |
680 | |
681 | arg.iov[0].iov_base = (unsigned char *)&rep; | |
682 | arg.iov[0].iov_len = sizeof(rep.th); | |
683 | if (ts) { | |
cfb6eeb4 YH |
684 | rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
685 | (TCPOPT_TIMESTAMP << 8) | | |
686 | TCPOLEN_TIMESTAMP); | |
687 | rep.opt[1] = htonl(tcp_time_stamp); | |
688 | rep.opt[2] = htonl(ts); | |
cb48cfe8 | 689 | arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED; |
1da177e4 LT |
690 | } |
691 | ||
692 | /* Swap the send and the receive. */ | |
693 | rep.th.dest = th->source; | |
694 | rep.th.source = th->dest; | |
695 | rep.th.doff = arg.iov[0].iov_len / 4; | |
696 | rep.th.seq = htonl(seq); | |
697 | rep.th.ack_seq = htonl(ack); | |
698 | rep.th.ack = 1; | |
699 | rep.th.window = htons(win); | |
700 | ||
cfb6eeb4 | 701 | #ifdef CONFIG_TCP_MD5SIG |
cfb6eeb4 YH |
702 | if (key) { |
703 | int offset = (ts) ? 3 : 0; | |
704 | ||
705 | rep.opt[offset++] = htonl((TCPOPT_NOP << 24) | | |
706 | (TCPOPT_NOP << 16) | | |
707 | (TCPOPT_MD5SIG << 8) | | |
708 | TCPOLEN_MD5SIG); | |
709 | arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; | |
710 | rep.th.doff = arg.iov[0].iov_len/4; | |
711 | ||
49a72dfb | 712 | tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset], |
90b7e112 AL |
713 | key, ip_hdr(skb)->saddr, |
714 | ip_hdr(skb)->daddr, &rep.th); | |
cfb6eeb4 YH |
715 | } |
716 | #endif | |
88ef4a5a | 717 | arg.flags = reply_flags; |
eddc9ec5 ACM |
718 | arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, |
719 | ip_hdr(skb)->saddr, /* XXX */ | |
1da177e4 LT |
720 | arg.iov[0].iov_len, IPPROTO_TCP, 0); |
721 | arg.csumoffset = offsetof(struct tcphdr, check) / 2; | |
9501f972 YH |
722 | if (oif) |
723 | arg.bound_dev_if = oif; | |
1da177e4 | 724 | |
a86b1e30 | 725 | ip_send_reply(net->ipv4.tcp_sock, skb, |
7feb49c8 | 726 | &arg, arg.iov[0].iov_len); |
1da177e4 | 727 | |
63231bdd | 728 | TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS); |
1da177e4 LT |
729 | } |
730 | ||
731 | static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb) | |
732 | { | |
8feaf0c0 | 733 | struct inet_timewait_sock *tw = inet_twsk(sk); |
cfb6eeb4 | 734 | struct tcp_timewait_sock *tcptw = tcp_twsk(sk); |
1da177e4 | 735 | |
9501f972 | 736 | tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, |
7174259e | 737 | tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, |
9501f972 YH |
738 | tcptw->tw_ts_recent, |
739 | tw->tw_bound_dev_if, | |
88ef4a5a KK |
740 | tcp_twsk_md5_key(tcptw), |
741 | tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0 | |
9501f972 | 742 | ); |
1da177e4 | 743 | |
8feaf0c0 | 744 | inet_twsk_put(tw); |
1da177e4 LT |
745 | } |
746 | ||
6edafaaf | 747 | static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, |
7174259e | 748 | struct request_sock *req) |
1da177e4 | 749 | { |
9501f972 | 750 | tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1, |
cfb6eeb4 | 751 | tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd, |
9501f972 YH |
752 | req->ts_recent, |
753 | 0, | |
88ef4a5a KK |
754 | tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr), |
755 | inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0); | |
1da177e4 LT |
756 | } |
757 | ||
1da177e4 | 758 | /* |
9bf1d83e | 759 | * Send a SYN-ACK after having received a SYN. |
60236fdd | 760 | * This still operates on a request_sock only, not on a big |
1da177e4 LT |
761 | * socket. |
762 | */ | |
72659ecc OP |
763 | static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst, |
764 | struct request_sock *req, | |
765 | struct request_values *rvp) | |
1da177e4 | 766 | { |
2e6599cb | 767 | const struct inet_request_sock *ireq = inet_rsk(req); |
1da177e4 LT |
768 | int err = -1; |
769 | struct sk_buff * skb; | |
770 | ||
771 | /* First, grab a route. */ | |
463c84b9 | 772 | if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL) |
fd80eb94 | 773 | return -1; |
1da177e4 | 774 | |
e6b4d113 | 775 | skb = tcp_make_synack(sk, dst, req, rvp); |
1da177e4 LT |
776 | |
777 | if (skb) { | |
419f9f89 | 778 | __tcp_v4_send_check(skb, ireq->loc_addr, ireq->rmt_addr); |
1da177e4 | 779 | |
2e6599cb ACM |
780 | err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr, |
781 | ireq->rmt_addr, | |
782 | ireq->opt); | |
b9df3cb8 | 783 | err = net_xmit_eval(err); |
1da177e4 LT |
784 | } |
785 | ||
1da177e4 LT |
786 | dst_release(dst); |
787 | return err; | |
788 | } | |
789 | ||
72659ecc | 790 | static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req, |
e6b4d113 | 791 | struct request_values *rvp) |
fd80eb94 | 792 | { |
72659ecc OP |
793 | TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS); |
794 | return tcp_v4_send_synack(sk, NULL, req, rvp); | |
fd80eb94 DL |
795 | } |
796 | ||
1da177e4 | 797 | /* |
60236fdd | 798 | * IPv4 request_sock destructor. |
1da177e4 | 799 | */ |
60236fdd | 800 | static void tcp_v4_reqsk_destructor(struct request_sock *req) |
1da177e4 | 801 | { |
a51482bd | 802 | kfree(inet_rsk(req)->opt); |
1da177e4 LT |
803 | } |
804 | ||
2a1d4bd4 | 805 | static void syn_flood_warning(const struct sk_buff *skb) |
1da177e4 | 806 | { |
2a1d4bd4 | 807 | const char *msg; |
1da177e4 | 808 | |
2a1d4bd4 FW |
809 | #ifdef CONFIG_SYN_COOKIES |
810 | if (sysctl_tcp_syncookies) | |
811 | msg = "Sending cookies"; | |
812 | else | |
80e40daa | 813 | #endif |
2a1d4bd4 FW |
814 | msg = "Dropping request"; |
815 | ||
816 | pr_info("TCP: Possible SYN flooding on port %d. %s.\n", | |
817 | ntohs(tcp_hdr(skb)->dest), msg); | |
818 | } | |
1da177e4 LT |
819 | |
820 | /* | |
60236fdd | 821 | * Save and compile IPv4 options into the request_sock if needed. |
1da177e4 | 822 | */ |
40efc6fa SH |
823 | static struct ip_options *tcp_v4_save_options(struct sock *sk, |
824 | struct sk_buff *skb) | |
1da177e4 LT |
825 | { |
826 | struct ip_options *opt = &(IPCB(skb)->opt); | |
827 | struct ip_options *dopt = NULL; | |
828 | ||
829 | if (opt && opt->optlen) { | |
830 | int opt_size = optlength(opt); | |
831 | dopt = kmalloc(opt_size, GFP_ATOMIC); | |
832 | if (dopt) { | |
833 | if (ip_options_echo(dopt, skb)) { | |
834 | kfree(dopt); | |
835 | dopt = NULL; | |
836 | } | |
837 | } | |
838 | } | |
839 | return dopt; | |
840 | } | |
841 | ||
cfb6eeb4 YH |
842 | #ifdef CONFIG_TCP_MD5SIG |
843 | /* | |
844 | * RFC2385 MD5 checksumming requires a mapping of | |
845 | * IP address->MD5 Key. | |
846 | * We need to maintain these in the sk structure. | |
847 | */ | |
848 | ||
849 | /* Find the Key structure for an address. */ | |
7174259e ACM |
850 | static struct tcp_md5sig_key * |
851 | tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr) | |
cfb6eeb4 YH |
852 | { |
853 | struct tcp_sock *tp = tcp_sk(sk); | |
854 | int i; | |
855 | ||
856 | if (!tp->md5sig_info || !tp->md5sig_info->entries4) | |
857 | return NULL; | |
858 | for (i = 0; i < tp->md5sig_info->entries4; i++) { | |
859 | if (tp->md5sig_info->keys4[i].addr == addr) | |
f8ab18d2 | 860 | return &tp->md5sig_info->keys4[i].base; |
cfb6eeb4 YH |
861 | } |
862 | return NULL; | |
863 | } | |
864 | ||
865 | struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk, | |
866 | struct sock *addr_sk) | |
867 | { | |
c720c7e8 | 868 | return tcp_v4_md5_do_lookup(sk, inet_sk(addr_sk)->inet_daddr); |
cfb6eeb4 | 869 | } |
cfb6eeb4 YH |
870 | EXPORT_SYMBOL(tcp_v4_md5_lookup); |
871 | ||
f5b99bcd AB |
872 | static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk, |
873 | struct request_sock *req) | |
cfb6eeb4 YH |
874 | { |
875 | return tcp_v4_md5_do_lookup(sk, inet_rsk(req)->rmt_addr); | |
876 | } | |
877 | ||
878 | /* This can be called on a newly created socket, from other files */ | |
879 | int tcp_v4_md5_do_add(struct sock *sk, __be32 addr, | |
880 | u8 *newkey, u8 newkeylen) | |
881 | { | |
882 | /* Add Key to the list */ | |
b0a713e9 | 883 | struct tcp_md5sig_key *key; |
cfb6eeb4 YH |
884 | struct tcp_sock *tp = tcp_sk(sk); |
885 | struct tcp4_md5sig_key *keys; | |
886 | ||
b0a713e9 | 887 | key = tcp_v4_md5_do_lookup(sk, addr); |
cfb6eeb4 YH |
888 | if (key) { |
889 | /* Pre-existing entry - just update that one. */ | |
b0a713e9 MD |
890 | kfree(key->key); |
891 | key->key = newkey; | |
892 | key->keylen = newkeylen; | |
cfb6eeb4 | 893 | } else { |
f6685938 ACM |
894 | struct tcp_md5sig_info *md5sig; |
895 | ||
cfb6eeb4 | 896 | if (!tp->md5sig_info) { |
f6685938 ACM |
897 | tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info), |
898 | GFP_ATOMIC); | |
cfb6eeb4 YH |
899 | if (!tp->md5sig_info) { |
900 | kfree(newkey); | |
901 | return -ENOMEM; | |
902 | } | |
a465419b | 903 | sk_nocaps_add(sk, NETIF_F_GSO_MASK); |
cfb6eeb4 | 904 | } |
aa133076 | 905 | if (tcp_alloc_md5sig_pool(sk) == NULL) { |
cfb6eeb4 YH |
906 | kfree(newkey); |
907 | return -ENOMEM; | |
908 | } | |
f6685938 ACM |
909 | md5sig = tp->md5sig_info; |
910 | ||
911 | if (md5sig->alloced4 == md5sig->entries4) { | |
912 | keys = kmalloc((sizeof(*keys) * | |
e905a9ed | 913 | (md5sig->entries4 + 1)), GFP_ATOMIC); |
cfb6eeb4 YH |
914 | if (!keys) { |
915 | kfree(newkey); | |
916 | tcp_free_md5sig_pool(); | |
917 | return -ENOMEM; | |
918 | } | |
919 | ||
f6685938 ACM |
920 | if (md5sig->entries4) |
921 | memcpy(keys, md5sig->keys4, | |
922 | sizeof(*keys) * md5sig->entries4); | |
cfb6eeb4 YH |
923 | |
924 | /* Free old key list, and reference new one */ | |
a80cc20d | 925 | kfree(md5sig->keys4); |
f6685938 ACM |
926 | md5sig->keys4 = keys; |
927 | md5sig->alloced4++; | |
cfb6eeb4 | 928 | } |
f6685938 | 929 | md5sig->entries4++; |
f8ab18d2 DM |
930 | md5sig->keys4[md5sig->entries4 - 1].addr = addr; |
931 | md5sig->keys4[md5sig->entries4 - 1].base.key = newkey; | |
932 | md5sig->keys4[md5sig->entries4 - 1].base.keylen = newkeylen; | |
cfb6eeb4 YH |
933 | } |
934 | return 0; | |
935 | } | |
cfb6eeb4 YH |
936 | EXPORT_SYMBOL(tcp_v4_md5_do_add); |
937 | ||
938 | static int tcp_v4_md5_add_func(struct sock *sk, struct sock *addr_sk, | |
939 | u8 *newkey, u8 newkeylen) | |
940 | { | |
c720c7e8 | 941 | return tcp_v4_md5_do_add(sk, inet_sk(addr_sk)->inet_daddr, |
cfb6eeb4 YH |
942 | newkey, newkeylen); |
943 | } | |
944 | ||
945 | int tcp_v4_md5_do_del(struct sock *sk, __be32 addr) | |
946 | { | |
947 | struct tcp_sock *tp = tcp_sk(sk); | |
948 | int i; | |
949 | ||
950 | for (i = 0; i < tp->md5sig_info->entries4; i++) { | |
951 | if (tp->md5sig_info->keys4[i].addr == addr) { | |
952 | /* Free the key */ | |
f8ab18d2 | 953 | kfree(tp->md5sig_info->keys4[i].base.key); |
cfb6eeb4 YH |
954 | tp->md5sig_info->entries4--; |
955 | ||
956 | if (tp->md5sig_info->entries4 == 0) { | |
957 | kfree(tp->md5sig_info->keys4); | |
958 | tp->md5sig_info->keys4 = NULL; | |
8228a18d | 959 | tp->md5sig_info->alloced4 = 0; |
7174259e | 960 | } else if (tp->md5sig_info->entries4 != i) { |
cfb6eeb4 | 961 | /* Need to do some manipulation */ |
354faf09 YH |
962 | memmove(&tp->md5sig_info->keys4[i], |
963 | &tp->md5sig_info->keys4[i+1], | |
964 | (tp->md5sig_info->entries4 - i) * | |
965 | sizeof(struct tcp4_md5sig_key)); | |
cfb6eeb4 YH |
966 | } |
967 | tcp_free_md5sig_pool(); | |
968 | return 0; | |
969 | } | |
970 | } | |
971 | return -ENOENT; | |
972 | } | |
cfb6eeb4 YH |
973 | EXPORT_SYMBOL(tcp_v4_md5_do_del); |
974 | ||
7174259e | 975 | static void tcp_v4_clear_md5_list(struct sock *sk) |
cfb6eeb4 YH |
976 | { |
977 | struct tcp_sock *tp = tcp_sk(sk); | |
978 | ||
979 | /* Free each key, then the set of key keys, | |
980 | * the crypto element, and then decrement our | |
981 | * hold on the last resort crypto. | |
982 | */ | |
983 | if (tp->md5sig_info->entries4) { | |
984 | int i; | |
985 | for (i = 0; i < tp->md5sig_info->entries4; i++) | |
f8ab18d2 | 986 | kfree(tp->md5sig_info->keys4[i].base.key); |
cfb6eeb4 YH |
987 | tp->md5sig_info->entries4 = 0; |
988 | tcp_free_md5sig_pool(); | |
989 | } | |
990 | if (tp->md5sig_info->keys4) { | |
991 | kfree(tp->md5sig_info->keys4); | |
992 | tp->md5sig_info->keys4 = NULL; | |
993 | tp->md5sig_info->alloced4 = 0; | |
994 | } | |
995 | } | |
996 | ||
7174259e ACM |
997 | static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval, |
998 | int optlen) | |
cfb6eeb4 YH |
999 | { |
1000 | struct tcp_md5sig cmd; | |
1001 | struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr; | |
1002 | u8 *newkey; | |
1003 | ||
1004 | if (optlen < sizeof(cmd)) | |
1005 | return -EINVAL; | |
1006 | ||
7174259e | 1007 | if (copy_from_user(&cmd, optval, sizeof(cmd))) |
cfb6eeb4 YH |
1008 | return -EFAULT; |
1009 | ||
1010 | if (sin->sin_family != AF_INET) | |
1011 | return -EINVAL; | |
1012 | ||
1013 | if (!cmd.tcpm_key || !cmd.tcpm_keylen) { | |
1014 | if (!tcp_sk(sk)->md5sig_info) | |
1015 | return -ENOENT; | |
1016 | return tcp_v4_md5_do_del(sk, sin->sin_addr.s_addr); | |
1017 | } | |
1018 | ||
1019 | if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) | |
1020 | return -EINVAL; | |
1021 | ||
1022 | if (!tcp_sk(sk)->md5sig_info) { | |
1023 | struct tcp_sock *tp = tcp_sk(sk); | |
aa133076 | 1024 | struct tcp_md5sig_info *p; |
cfb6eeb4 | 1025 | |
aa133076 | 1026 | p = kzalloc(sizeof(*p), sk->sk_allocation); |
cfb6eeb4 YH |
1027 | if (!p) |
1028 | return -EINVAL; | |
1029 | ||
1030 | tp->md5sig_info = p; | |
a465419b | 1031 | sk_nocaps_add(sk, NETIF_F_GSO_MASK); |
cfb6eeb4 YH |
1032 | } |
1033 | ||
aa133076 | 1034 | newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, sk->sk_allocation); |
cfb6eeb4 YH |
1035 | if (!newkey) |
1036 | return -ENOMEM; | |
cfb6eeb4 YH |
1037 | return tcp_v4_md5_do_add(sk, sin->sin_addr.s_addr, |
1038 | newkey, cmd.tcpm_keylen); | |
1039 | } | |
1040 | ||
49a72dfb AL |
1041 | static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp, |
1042 | __be32 daddr, __be32 saddr, int nbytes) | |
cfb6eeb4 | 1043 | { |
cfb6eeb4 | 1044 | struct tcp4_pseudohdr *bp; |
49a72dfb | 1045 | struct scatterlist sg; |
cfb6eeb4 YH |
1046 | |
1047 | bp = &hp->md5_blk.ip4; | |
cfb6eeb4 YH |
1048 | |
1049 | /* | |
49a72dfb | 1050 | * 1. the TCP pseudo-header (in the order: source IP address, |
cfb6eeb4 YH |
1051 | * destination IP address, zero-padded protocol number, and |
1052 | * segment length) | |
1053 | */ | |
1054 | bp->saddr = saddr; | |
1055 | bp->daddr = daddr; | |
1056 | bp->pad = 0; | |
076fb722 | 1057 | bp->protocol = IPPROTO_TCP; |
49a72dfb | 1058 | bp->len = cpu_to_be16(nbytes); |
c7da57a1 | 1059 | |
49a72dfb AL |
1060 | sg_init_one(&sg, bp, sizeof(*bp)); |
1061 | return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp)); | |
1062 | } | |
1063 | ||
1064 | static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key, | |
1065 | __be32 daddr, __be32 saddr, struct tcphdr *th) | |
1066 | { | |
1067 | struct tcp_md5sig_pool *hp; | |
1068 | struct hash_desc *desc; | |
1069 | ||
1070 | hp = tcp_get_md5sig_pool(); | |
1071 | if (!hp) | |
1072 | goto clear_hash_noput; | |
1073 | desc = &hp->md5_desc; | |
1074 | ||
1075 | if (crypto_hash_init(desc)) | |
1076 | goto clear_hash; | |
1077 | if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2)) | |
1078 | goto clear_hash; | |
1079 | if (tcp_md5_hash_header(hp, th)) | |
1080 | goto clear_hash; | |
1081 | if (tcp_md5_hash_key(hp, key)) | |
1082 | goto clear_hash; | |
1083 | if (crypto_hash_final(desc, md5_hash)) | |
cfb6eeb4 YH |
1084 | goto clear_hash; |
1085 | ||
cfb6eeb4 | 1086 | tcp_put_md5sig_pool(); |
cfb6eeb4 | 1087 | return 0; |
49a72dfb | 1088 | |
cfb6eeb4 YH |
1089 | clear_hash: |
1090 | tcp_put_md5sig_pool(); | |
1091 | clear_hash_noput: | |
1092 | memset(md5_hash, 0, 16); | |
49a72dfb | 1093 | return 1; |
cfb6eeb4 YH |
1094 | } |
1095 | ||
49a72dfb AL |
1096 | int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key, |
1097 | struct sock *sk, struct request_sock *req, | |
1098 | struct sk_buff *skb) | |
cfb6eeb4 | 1099 | { |
49a72dfb AL |
1100 | struct tcp_md5sig_pool *hp; |
1101 | struct hash_desc *desc; | |
1102 | struct tcphdr *th = tcp_hdr(skb); | |
cfb6eeb4 YH |
1103 | __be32 saddr, daddr; |
1104 | ||
1105 | if (sk) { | |
c720c7e8 ED |
1106 | saddr = inet_sk(sk)->inet_saddr; |
1107 | daddr = inet_sk(sk)->inet_daddr; | |
49a72dfb AL |
1108 | } else if (req) { |
1109 | saddr = inet_rsk(req)->loc_addr; | |
1110 | daddr = inet_rsk(req)->rmt_addr; | |
cfb6eeb4 | 1111 | } else { |
49a72dfb AL |
1112 | const struct iphdr *iph = ip_hdr(skb); |
1113 | saddr = iph->saddr; | |
1114 | daddr = iph->daddr; | |
cfb6eeb4 | 1115 | } |
49a72dfb AL |
1116 | |
1117 | hp = tcp_get_md5sig_pool(); | |
1118 | if (!hp) | |
1119 | goto clear_hash_noput; | |
1120 | desc = &hp->md5_desc; | |
1121 | ||
1122 | if (crypto_hash_init(desc)) | |
1123 | goto clear_hash; | |
1124 | ||
1125 | if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, skb->len)) | |
1126 | goto clear_hash; | |
1127 | if (tcp_md5_hash_header(hp, th)) | |
1128 | goto clear_hash; | |
1129 | if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2)) | |
1130 | goto clear_hash; | |
1131 | if (tcp_md5_hash_key(hp, key)) | |
1132 | goto clear_hash; | |
1133 | if (crypto_hash_final(desc, md5_hash)) | |
1134 | goto clear_hash; | |
1135 | ||
1136 | tcp_put_md5sig_pool(); | |
1137 | return 0; | |
1138 | ||
1139 | clear_hash: | |
1140 | tcp_put_md5sig_pool(); | |
1141 | clear_hash_noput: | |
1142 | memset(md5_hash, 0, 16); | |
1143 | return 1; | |
cfb6eeb4 | 1144 | } |
49a72dfb | 1145 | EXPORT_SYMBOL(tcp_v4_md5_hash_skb); |
cfb6eeb4 | 1146 | |
7174259e | 1147 | static int tcp_v4_inbound_md5_hash(struct sock *sk, struct sk_buff *skb) |
cfb6eeb4 YH |
1148 | { |
1149 | /* | |
1150 | * This gets called for each TCP segment that arrives | |
1151 | * so we want to be efficient. | |
1152 | * We have 3 drop cases: | |
1153 | * o No MD5 hash and one expected. | |
1154 | * o MD5 hash and we're not expecting one. | |
1155 | * o MD5 hash and its wrong. | |
1156 | */ | |
1157 | __u8 *hash_location = NULL; | |
1158 | struct tcp_md5sig_key *hash_expected; | |
eddc9ec5 | 1159 | const struct iphdr *iph = ip_hdr(skb); |
aa8223c7 | 1160 | struct tcphdr *th = tcp_hdr(skb); |
cfb6eeb4 | 1161 | int genhash; |
cfb6eeb4 YH |
1162 | unsigned char newhash[16]; |
1163 | ||
1164 | hash_expected = tcp_v4_md5_do_lookup(sk, iph->saddr); | |
7d5d5525 | 1165 | hash_location = tcp_parse_md5sig_option(th); |
cfb6eeb4 | 1166 | |
cfb6eeb4 YH |
1167 | /* We've parsed the options - do we have a hash? */ |
1168 | if (!hash_expected && !hash_location) | |
1169 | return 0; | |
1170 | ||
1171 | if (hash_expected && !hash_location) { | |
785957d3 | 1172 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); |
cfb6eeb4 YH |
1173 | return 1; |
1174 | } | |
1175 | ||
1176 | if (!hash_expected && hash_location) { | |
785957d3 | 1177 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); |
cfb6eeb4 YH |
1178 | return 1; |
1179 | } | |
1180 | ||
1181 | /* Okay, so this is hash_expected and hash_location - | |
1182 | * so we need to calculate the checksum. | |
1183 | */ | |
49a72dfb AL |
1184 | genhash = tcp_v4_md5_hash_skb(newhash, |
1185 | hash_expected, | |
1186 | NULL, NULL, skb); | |
cfb6eeb4 YH |
1187 | |
1188 | if (genhash || memcmp(hash_location, newhash, 16) != 0) { | |
1189 | if (net_ratelimit()) { | |
673d57e7 HH |
1190 | printk(KERN_INFO "MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n", |
1191 | &iph->saddr, ntohs(th->source), | |
1192 | &iph->daddr, ntohs(th->dest), | |
cfb6eeb4 | 1193 | genhash ? " tcp_v4_calc_md5_hash failed" : ""); |
cfb6eeb4 YH |
1194 | } |
1195 | return 1; | |
1196 | } | |
1197 | return 0; | |
1198 | } | |
1199 | ||
1200 | #endif | |
1201 | ||
72a3effa | 1202 | struct request_sock_ops tcp_request_sock_ops __read_mostly = { |
1da177e4 | 1203 | .family = PF_INET, |
2e6599cb | 1204 | .obj_size = sizeof(struct tcp_request_sock), |
72659ecc | 1205 | .rtx_syn_ack = tcp_v4_rtx_synack, |
60236fdd ACM |
1206 | .send_ack = tcp_v4_reqsk_send_ack, |
1207 | .destructor = tcp_v4_reqsk_destructor, | |
1da177e4 | 1208 | .send_reset = tcp_v4_send_reset, |
72659ecc | 1209 | .syn_ack_timeout = tcp_syn_ack_timeout, |
1da177e4 LT |
1210 | }; |
1211 | ||
cfb6eeb4 | 1212 | #ifdef CONFIG_TCP_MD5SIG |
b2e4b3de | 1213 | static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = { |
cfb6eeb4 | 1214 | .md5_lookup = tcp_v4_reqsk_md5_lookup, |
e3afe7b7 | 1215 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
cfb6eeb4 | 1216 | }; |
b6332e6c | 1217 | #endif |
cfb6eeb4 | 1218 | |
1da177e4 LT |
1219 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) |
1220 | { | |
4957faad | 1221 | struct tcp_extend_values tmp_ext; |
1da177e4 | 1222 | struct tcp_options_received tmp_opt; |
4957faad | 1223 | u8 *hash_location; |
60236fdd | 1224 | struct request_sock *req; |
e6b4d113 | 1225 | struct inet_request_sock *ireq; |
4957faad | 1226 | struct tcp_sock *tp = tcp_sk(sk); |
e6b4d113 | 1227 | struct dst_entry *dst = NULL; |
eddc9ec5 ACM |
1228 | __be32 saddr = ip_hdr(skb)->saddr; |
1229 | __be32 daddr = ip_hdr(skb)->daddr; | |
1da177e4 | 1230 | __u32 isn = TCP_SKB_CB(skb)->when; |
1da177e4 LT |
1231 | #ifdef CONFIG_SYN_COOKIES |
1232 | int want_cookie = 0; | |
1233 | #else | |
1234 | #define want_cookie 0 /* Argh, why doesn't gcc optimize this :( */ | |
1235 | #endif | |
1236 | ||
1237 | /* Never answer to SYNs send to broadcast or multicast */ | |
511c3f92 | 1238 | if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) |
1da177e4 LT |
1239 | goto drop; |
1240 | ||
1241 | /* TW buckets are converted to open requests without | |
1242 | * limitations, they conserve resources and peer is | |
1243 | * evidently real one. | |
1244 | */ | |
463c84b9 | 1245 | if (inet_csk_reqsk_queue_is_full(sk) && !isn) { |
2a1d4bd4 FW |
1246 | if (net_ratelimit()) |
1247 | syn_flood_warning(skb); | |
1da177e4 LT |
1248 | #ifdef CONFIG_SYN_COOKIES |
1249 | if (sysctl_tcp_syncookies) { | |
1250 | want_cookie = 1; | |
1251 | } else | |
1252 | #endif | |
1253 | goto drop; | |
1254 | } | |
1255 | ||
1256 | /* Accept backlog is full. If we have already queued enough | |
1257 | * of warm entries in syn queue, drop request. It is better than | |
1258 | * clogging syn queue with openreqs with exponentially increasing | |
1259 | * timeout. | |
1260 | */ | |
463c84b9 | 1261 | if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) |
1da177e4 LT |
1262 | goto drop; |
1263 | ||
ce4a7d0d | 1264 | req = inet_reqsk_alloc(&tcp_request_sock_ops); |
1da177e4 LT |
1265 | if (!req) |
1266 | goto drop; | |
1267 | ||
cfb6eeb4 YH |
1268 | #ifdef CONFIG_TCP_MD5SIG |
1269 | tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops; | |
1270 | #endif | |
1271 | ||
1da177e4 | 1272 | tcp_clear_options(&tmp_opt); |
bee7ca9e | 1273 | tmp_opt.mss_clamp = TCP_MSS_DEFAULT; |
4957faad | 1274 | tmp_opt.user_mss = tp->rx_opt.user_mss; |
bb5b7c11 | 1275 | tcp_parse_options(skb, &tmp_opt, &hash_location, 0); |
4957faad WAS |
1276 | |
1277 | if (tmp_opt.cookie_plus > 0 && | |
1278 | tmp_opt.saw_tstamp && | |
1279 | !tp->rx_opt.cookie_out_never && | |
1280 | (sysctl_tcp_cookie_size > 0 || | |
1281 | (tp->cookie_values != NULL && | |
1282 | tp->cookie_values->cookie_desired > 0))) { | |
1283 | u8 *c; | |
1284 | u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS]; | |
1285 | int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE; | |
1286 | ||
1287 | if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0) | |
1288 | goto drop_and_release; | |
1289 | ||
1290 | /* Secret recipe starts with IP addresses */ | |
0eae88f3 ED |
1291 | *mess++ ^= (__force u32)daddr; |
1292 | *mess++ ^= (__force u32)saddr; | |
1da177e4 | 1293 | |
4957faad WAS |
1294 | /* plus variable length Initiator Cookie */ |
1295 | c = (u8 *)mess; | |
1296 | while (l-- > 0) | |
1297 | *c++ ^= *hash_location++; | |
1298 | ||
1299 | #ifdef CONFIG_SYN_COOKIES | |
1300 | want_cookie = 0; /* not our kind of cookie */ | |
1301 | #endif | |
1302 | tmp_ext.cookie_out_never = 0; /* false */ | |
1303 | tmp_ext.cookie_plus = tmp_opt.cookie_plus; | |
1304 | } else if (!tp->rx_opt.cookie_in_always) { | |
1305 | /* redundant indications, but ensure initialization. */ | |
1306 | tmp_ext.cookie_out_never = 1; /* true */ | |
1307 | tmp_ext.cookie_plus = 0; | |
1308 | } else { | |
1309 | goto drop_and_release; | |
1310 | } | |
1311 | tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always; | |
1da177e4 | 1312 | |
4dfc2817 | 1313 | if (want_cookie && !tmp_opt.saw_tstamp) |
1da177e4 | 1314 | tcp_clear_options(&tmp_opt); |
1da177e4 | 1315 | |
1da177e4 | 1316 | tmp_opt.tstamp_ok = tmp_opt.saw_tstamp; |
1da177e4 LT |
1317 | tcp_openreq_init(req, &tmp_opt, skb); |
1318 | ||
bb5b7c11 DM |
1319 | ireq = inet_rsk(req); |
1320 | ireq->loc_addr = daddr; | |
1321 | ireq->rmt_addr = saddr; | |
1322 | ireq->no_srccheck = inet_sk(sk)->transparent; | |
1323 | ireq->opt = tcp_v4_save_options(sk, skb); | |
1324 | ||
284904aa | 1325 | if (security_inet_conn_request(sk, skb, req)) |
bb5b7c11 | 1326 | goto drop_and_free; |
284904aa | 1327 | |
172d69e6 | 1328 | if (!want_cookie || tmp_opt.tstamp_ok) |
aa8223c7 | 1329 | TCP_ECN_create_request(req, tcp_hdr(skb)); |
1da177e4 LT |
1330 | |
1331 | if (want_cookie) { | |
1da177e4 | 1332 | isn = cookie_v4_init_sequence(sk, skb, &req->mss); |
172d69e6 | 1333 | req->cookie_ts = tmp_opt.tstamp_ok; |
1da177e4 LT |
1334 | } else if (!isn) { |
1335 | struct inet_peer *peer = NULL; | |
1336 | ||
1337 | /* VJ's idea. We save last timestamp seen | |
1338 | * from the destination in peer table, when entering | |
1339 | * state TIME-WAIT, and check against it before | |
1340 | * accepting new connection request. | |
1341 | * | |
1342 | * If "isn" is not zero, this request hit alive | |
1343 | * timewait bucket, so that all the necessary checks | |
1344 | * are made in the function processing timewait state. | |
1345 | */ | |
1346 | if (tmp_opt.saw_tstamp && | |
295ff7ed | 1347 | tcp_death_row.sysctl_tw_recycle && |
bb5b7c11 | 1348 | (dst = inet_csk_route_req(sk, req)) != NULL && |
1da177e4 | 1349 | (peer = rt_get_peer((struct rtable *)dst)) != NULL && |
7a71ed89 | 1350 | peer->daddr.addr.a4 == saddr) { |
317fe0e6 | 1351 | inet_peer_refcheck(peer); |
2c1409a0 | 1352 | if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL && |
1da177e4 LT |
1353 | (s32)(peer->tcp_ts - req->ts_recent) > |
1354 | TCP_PAWS_WINDOW) { | |
de0744af | 1355 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED); |
7cd04fa7 | 1356 | goto drop_and_release; |
1da177e4 LT |
1357 | } |
1358 | } | |
1359 | /* Kill the following clause, if you dislike this way. */ | |
1360 | else if (!sysctl_tcp_syncookies && | |
463c84b9 | 1361 | (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) < |
1da177e4 LT |
1362 | (sysctl_max_syn_backlog >> 2)) && |
1363 | (!peer || !peer->tcp_ts_stamp) && | |
1364 | (!dst || !dst_metric(dst, RTAX_RTT))) { | |
1365 | /* Without syncookies last quarter of | |
1366 | * backlog is filled with destinations, | |
1367 | * proven to be alive. | |
1368 | * It means that we continue to communicate | |
1369 | * to destinations, already remembered | |
1370 | * to the moment of synflood. | |
1371 | */ | |
673d57e7 HH |
1372 | LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open request from %pI4/%u\n", |
1373 | &saddr, ntohs(tcp_hdr(skb)->source)); | |
7cd04fa7 | 1374 | goto drop_and_release; |
1da177e4 LT |
1375 | } |
1376 | ||
a94f723d | 1377 | isn = tcp_v4_init_sequence(skb); |
1da177e4 | 1378 | } |
2e6599cb | 1379 | tcp_rsk(req)->snt_isn = isn; |
1da177e4 | 1380 | |
72659ecc OP |
1381 | if (tcp_v4_send_synack(sk, dst, req, |
1382 | (struct request_values *)&tmp_ext) || | |
4957faad | 1383 | want_cookie) |
1da177e4 LT |
1384 | goto drop_and_free; |
1385 | ||
7cd04fa7 | 1386 | inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT); |
1da177e4 LT |
1387 | return 0; |
1388 | ||
7cd04fa7 DL |
1389 | drop_and_release: |
1390 | dst_release(dst); | |
1da177e4 | 1391 | drop_and_free: |
60236fdd | 1392 | reqsk_free(req); |
1da177e4 | 1393 | drop: |
1da177e4 LT |
1394 | return 0; |
1395 | } | |
4bc2f18b | 1396 | EXPORT_SYMBOL(tcp_v4_conn_request); |
1da177e4 LT |
1397 | |
1398 | ||
1399 | /* | |
1400 | * The three way handshake has completed - we got a valid synack - | |
1401 | * now create the new socket. | |
1402 | */ | |
1403 | struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, | |
60236fdd | 1404 | struct request_sock *req, |
1da177e4 LT |
1405 | struct dst_entry *dst) |
1406 | { | |
2e6599cb | 1407 | struct inet_request_sock *ireq; |
1da177e4 LT |
1408 | struct inet_sock *newinet; |
1409 | struct tcp_sock *newtp; | |
1410 | struct sock *newsk; | |
cfb6eeb4 YH |
1411 | #ifdef CONFIG_TCP_MD5SIG |
1412 | struct tcp_md5sig_key *key; | |
1413 | #endif | |
1da177e4 LT |
1414 | |
1415 | if (sk_acceptq_is_full(sk)) | |
1416 | goto exit_overflow; | |
1417 | ||
463c84b9 | 1418 | if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL) |
1da177e4 LT |
1419 | goto exit; |
1420 | ||
1421 | newsk = tcp_create_openreq_child(sk, req, skb); | |
1422 | if (!newsk) | |
093d2823 | 1423 | goto exit_nonewsk; |
1da177e4 | 1424 | |
bcd76111 | 1425 | newsk->sk_gso_type = SKB_GSO_TCPV4; |
6cbb0df7 | 1426 | sk_setup_caps(newsk, dst); |
1da177e4 LT |
1427 | |
1428 | newtp = tcp_sk(newsk); | |
1429 | newinet = inet_sk(newsk); | |
2e6599cb | 1430 | ireq = inet_rsk(req); |
c720c7e8 ED |
1431 | newinet->inet_daddr = ireq->rmt_addr; |
1432 | newinet->inet_rcv_saddr = ireq->loc_addr; | |
1433 | newinet->inet_saddr = ireq->loc_addr; | |
2e6599cb ACM |
1434 | newinet->opt = ireq->opt; |
1435 | ireq->opt = NULL; | |
463c84b9 | 1436 | newinet->mc_index = inet_iif(skb); |
eddc9ec5 | 1437 | newinet->mc_ttl = ip_hdr(skb)->ttl; |
d83d8461 | 1438 | inet_csk(newsk)->icsk_ext_hdr_len = 0; |
1da177e4 | 1439 | if (newinet->opt) |
d83d8461 | 1440 | inet_csk(newsk)->icsk_ext_hdr_len = newinet->opt->optlen; |
c720c7e8 | 1441 | newinet->inet_id = newtp->write_seq ^ jiffies; |
1da177e4 | 1442 | |
5d424d5a | 1443 | tcp_mtup_init(newsk); |
1da177e4 | 1444 | tcp_sync_mss(newsk, dst_mtu(dst)); |
0dbaee3b | 1445 | newtp->advmss = dst_metric_advmss(dst); |
f5fff5dc TQ |
1446 | if (tcp_sk(sk)->rx_opt.user_mss && |
1447 | tcp_sk(sk)->rx_opt.user_mss < newtp->advmss) | |
1448 | newtp->advmss = tcp_sk(sk)->rx_opt.user_mss; | |
1449 | ||
1da177e4 LT |
1450 | tcp_initialize_rcv_mss(newsk); |
1451 | ||
cfb6eeb4 YH |
1452 | #ifdef CONFIG_TCP_MD5SIG |
1453 | /* Copy over the MD5 key from the original socket */ | |
c720c7e8 ED |
1454 | key = tcp_v4_md5_do_lookup(sk, newinet->inet_daddr); |
1455 | if (key != NULL) { | |
cfb6eeb4 YH |
1456 | /* |
1457 | * We're using one, so create a matching key | |
1458 | * on the newsk structure. If we fail to get | |
1459 | * memory, then we end up not copying the key | |
1460 | * across. Shucks. | |
1461 | */ | |
f6685938 ACM |
1462 | char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC); |
1463 | if (newkey != NULL) | |
c720c7e8 | 1464 | tcp_v4_md5_do_add(newsk, newinet->inet_daddr, |
cfb6eeb4 | 1465 | newkey, key->keylen); |
a465419b | 1466 | sk_nocaps_add(newsk, NETIF_F_GSO_MASK); |
cfb6eeb4 YH |
1467 | } |
1468 | #endif | |
1469 | ||
093d2823 BS |
1470 | if (__inet_inherit_port(sk, newsk) < 0) { |
1471 | sock_put(newsk); | |
1472 | goto exit; | |
1473 | } | |
9327f705 | 1474 | __inet_hash_nolisten(newsk, NULL); |
1da177e4 LT |
1475 | |
1476 | return newsk; | |
1477 | ||
1478 | exit_overflow: | |
de0744af | 1479 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); |
093d2823 BS |
1480 | exit_nonewsk: |
1481 | dst_release(dst); | |
1da177e4 | 1482 | exit: |
de0744af | 1483 | NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); |
1da177e4 LT |
1484 | return NULL; |
1485 | } | |
4bc2f18b | 1486 | EXPORT_SYMBOL(tcp_v4_syn_recv_sock); |
1da177e4 LT |
1487 | |
1488 | static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb) | |
1489 | { | |
aa8223c7 | 1490 | struct tcphdr *th = tcp_hdr(skb); |
eddc9ec5 | 1491 | const struct iphdr *iph = ip_hdr(skb); |
1da177e4 | 1492 | struct sock *nsk; |
60236fdd | 1493 | struct request_sock **prev; |
1da177e4 | 1494 | /* Find possible connection requests. */ |
463c84b9 ACM |
1495 | struct request_sock *req = inet_csk_search_req(sk, &prev, th->source, |
1496 | iph->saddr, iph->daddr); | |
1da177e4 LT |
1497 | if (req) |
1498 | return tcp_check_req(sk, skb, req, prev); | |
1499 | ||
3b1e0a65 | 1500 | nsk = inet_lookup_established(sock_net(sk), &tcp_hashinfo, iph->saddr, |
c67499c0 | 1501 | th->source, iph->daddr, th->dest, inet_iif(skb)); |
1da177e4 LT |
1502 | |
1503 | if (nsk) { | |
1504 | if (nsk->sk_state != TCP_TIME_WAIT) { | |
1505 | bh_lock_sock(nsk); | |
1506 | return nsk; | |
1507 | } | |
9469c7b4 | 1508 | inet_twsk_put(inet_twsk(nsk)); |
1da177e4 LT |
1509 | return NULL; |
1510 | } | |
1511 | ||
1512 | #ifdef CONFIG_SYN_COOKIES | |
af9b4738 | 1513 | if (!th->syn) |
1da177e4 LT |
1514 | sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt)); |
1515 | #endif | |
1516 | return sk; | |
1517 | } | |
1518 | ||
b51655b9 | 1519 | static __sum16 tcp_v4_checksum_init(struct sk_buff *skb) |
1da177e4 | 1520 | { |
eddc9ec5 ACM |
1521 | const struct iphdr *iph = ip_hdr(skb); |
1522 | ||
84fa7933 | 1523 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
eddc9ec5 ACM |
1524 | if (!tcp_v4_check(skb->len, iph->saddr, |
1525 | iph->daddr, skb->csum)) { | |
fb286bb2 | 1526 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
1da177e4 | 1527 | return 0; |
fb286bb2 | 1528 | } |
1da177e4 | 1529 | } |
fb286bb2 | 1530 | |
eddc9ec5 | 1531 | skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, |
fb286bb2 HX |
1532 | skb->len, IPPROTO_TCP, 0); |
1533 | ||
1da177e4 | 1534 | if (skb->len <= 76) { |
fb286bb2 | 1535 | return __skb_checksum_complete(skb); |
1da177e4 LT |
1536 | } |
1537 | return 0; | |
1538 | } | |
1539 | ||
1540 | ||
1541 | /* The socket must have it's spinlock held when we get | |
1542 | * here. | |
1543 | * | |
1544 | * We have a potential double-lock case here, so even when | |
1545 | * doing backlog processing we use the BH locking scheme. | |
1546 | * This is because we cannot sleep with the original spinlock | |
1547 | * held. | |
1548 | */ | |
1549 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) | |
1550 | { | |
cfb6eeb4 YH |
1551 | struct sock *rsk; |
1552 | #ifdef CONFIG_TCP_MD5SIG | |
1553 | /* | |
1554 | * We really want to reject the packet as early as possible | |
1555 | * if: | |
1556 | * o We're expecting an MD5'd packet and this is no MD5 tcp option | |
1557 | * o There is an MD5 option and we're not expecting one | |
1558 | */ | |
7174259e | 1559 | if (tcp_v4_inbound_md5_hash(sk, skb)) |
cfb6eeb4 YH |
1560 | goto discard; |
1561 | #endif | |
1562 | ||
1da177e4 | 1563 | if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ |
ca55158c | 1564 | sock_rps_save_rxhash(sk, skb->rxhash); |
aa8223c7 | 1565 | if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) { |
cfb6eeb4 | 1566 | rsk = sk; |
1da177e4 | 1567 | goto reset; |
cfb6eeb4 | 1568 | } |
1da177e4 LT |
1569 | return 0; |
1570 | } | |
1571 | ||
ab6a5bb6 | 1572 | if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb)) |
1da177e4 LT |
1573 | goto csum_err; |
1574 | ||
1575 | if (sk->sk_state == TCP_LISTEN) { | |
1576 | struct sock *nsk = tcp_v4_hnd_req(sk, skb); | |
1577 | if (!nsk) | |
1578 | goto discard; | |
1579 | ||
1580 | if (nsk != sk) { | |
cfb6eeb4 YH |
1581 | if (tcp_child_process(sk, nsk, skb)) { |
1582 | rsk = nsk; | |
1da177e4 | 1583 | goto reset; |
cfb6eeb4 | 1584 | } |
1da177e4 LT |
1585 | return 0; |
1586 | } | |
ca55158c ED |
1587 | } else |
1588 | sock_rps_save_rxhash(sk, skb->rxhash); | |
1589 | ||
aa8223c7 | 1590 | if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) { |
cfb6eeb4 | 1591 | rsk = sk; |
1da177e4 | 1592 | goto reset; |
cfb6eeb4 | 1593 | } |
1da177e4 LT |
1594 | return 0; |
1595 | ||
1596 | reset: | |
cfb6eeb4 | 1597 | tcp_v4_send_reset(rsk, skb); |
1da177e4 LT |
1598 | discard: |
1599 | kfree_skb(skb); | |
1600 | /* Be careful here. If this function gets more complicated and | |
1601 | * gcc suffers from register pressure on the x86, sk (in %ebx) | |
1602 | * might be destroyed here. This current version compiles correctly, | |
1603 | * but you have been warned. | |
1604 | */ | |
1605 | return 0; | |
1606 | ||
1607 | csum_err: | |
63231bdd | 1608 | TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS); |
1da177e4 LT |
1609 | goto discard; |
1610 | } | |
4bc2f18b | 1611 | EXPORT_SYMBOL(tcp_v4_do_rcv); |
1da177e4 LT |
1612 | |
1613 | /* | |
1614 | * From tcp_input.c | |
1615 | */ | |
1616 | ||
1617 | int tcp_v4_rcv(struct sk_buff *skb) | |
1618 | { | |
eddc9ec5 | 1619 | const struct iphdr *iph; |
1da177e4 LT |
1620 | struct tcphdr *th; |
1621 | struct sock *sk; | |
1622 | int ret; | |
a86b1e30 | 1623 | struct net *net = dev_net(skb->dev); |
1da177e4 LT |
1624 | |
1625 | if (skb->pkt_type != PACKET_HOST) | |
1626 | goto discard_it; | |
1627 | ||
1628 | /* Count it even if it's bad */ | |
63231bdd | 1629 | TCP_INC_STATS_BH(net, TCP_MIB_INSEGS); |
1da177e4 LT |
1630 | |
1631 | if (!pskb_may_pull(skb, sizeof(struct tcphdr))) | |
1632 | goto discard_it; | |
1633 | ||
aa8223c7 | 1634 | th = tcp_hdr(skb); |
1da177e4 LT |
1635 | |
1636 | if (th->doff < sizeof(struct tcphdr) / 4) | |
1637 | goto bad_packet; | |
1638 | if (!pskb_may_pull(skb, th->doff * 4)) | |
1639 | goto discard_it; | |
1640 | ||
1641 | /* An explanation is required here, I think. | |
1642 | * Packet length and doff are validated by header prediction, | |
caa20d9a | 1643 | * provided case of th->doff==0 is eliminated. |
1da177e4 | 1644 | * So, we defer the checks. */ |
60476372 | 1645 | if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb)) |
1da177e4 LT |
1646 | goto bad_packet; |
1647 | ||
aa8223c7 | 1648 | th = tcp_hdr(skb); |
eddc9ec5 | 1649 | iph = ip_hdr(skb); |
1da177e4 LT |
1650 | TCP_SKB_CB(skb)->seq = ntohl(th->seq); |
1651 | TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + | |
1652 | skb->len - th->doff * 4); | |
1653 | TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); | |
1654 | TCP_SKB_CB(skb)->when = 0; | |
eddc9ec5 | 1655 | TCP_SKB_CB(skb)->flags = iph->tos; |
1da177e4 LT |
1656 | TCP_SKB_CB(skb)->sacked = 0; |
1657 | ||
9a1f27c4 | 1658 | sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest); |
1da177e4 LT |
1659 | if (!sk) |
1660 | goto no_tcp_socket; | |
1661 | ||
bb134d5d ED |
1662 | process: |
1663 | if (sk->sk_state == TCP_TIME_WAIT) | |
1664 | goto do_time_wait; | |
1665 | ||
6cce09f8 ED |
1666 | if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { |
1667 | NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP); | |
d218d111 | 1668 | goto discard_and_relse; |
6cce09f8 | 1669 | } |
d218d111 | 1670 | |
1da177e4 LT |
1671 | if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) |
1672 | goto discard_and_relse; | |
b59c2701 | 1673 | nf_reset(skb); |
1da177e4 | 1674 | |
fda9ef5d | 1675 | if (sk_filter(sk, skb)) |
1da177e4 LT |
1676 | goto discard_and_relse; |
1677 | ||
1678 | skb->dev = NULL; | |
1679 | ||
c6366184 | 1680 | bh_lock_sock_nested(sk); |
1da177e4 LT |
1681 | ret = 0; |
1682 | if (!sock_owned_by_user(sk)) { | |
1a2449a8 CL |
1683 | #ifdef CONFIG_NET_DMA |
1684 | struct tcp_sock *tp = tcp_sk(sk); | |
1685 | if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list) | |
f67b4599 | 1686 | tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY); |
1a2449a8 | 1687 | if (tp->ucopy.dma_chan) |
1da177e4 | 1688 | ret = tcp_v4_do_rcv(sk, skb); |
1a2449a8 CL |
1689 | else |
1690 | #endif | |
1691 | { | |
1692 | if (!tcp_prequeue(sk, skb)) | |
ae8d7f88 | 1693 | ret = tcp_v4_do_rcv(sk, skb); |
1a2449a8 | 1694 | } |
6cce09f8 | 1695 | } else if (unlikely(sk_add_backlog(sk, skb))) { |
6b03a53a | 1696 | bh_unlock_sock(sk); |
6cce09f8 | 1697 | NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP); |
6b03a53a ZY |
1698 | goto discard_and_relse; |
1699 | } | |
1da177e4 LT |
1700 | bh_unlock_sock(sk); |
1701 | ||
1702 | sock_put(sk); | |
1703 | ||
1704 | return ret; | |
1705 | ||
1706 | no_tcp_socket: | |
1707 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) | |
1708 | goto discard_it; | |
1709 | ||
1710 | if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) { | |
1711 | bad_packet: | |
63231bdd | 1712 | TCP_INC_STATS_BH(net, TCP_MIB_INERRS); |
1da177e4 | 1713 | } else { |
cfb6eeb4 | 1714 | tcp_v4_send_reset(NULL, skb); |
1da177e4 LT |
1715 | } |
1716 | ||
1717 | discard_it: | |
1718 | /* Discard frame. */ | |
1719 | kfree_skb(skb); | |
e905a9ed | 1720 | return 0; |
1da177e4 LT |
1721 | |
1722 | discard_and_relse: | |
1723 | sock_put(sk); | |
1724 | goto discard_it; | |
1725 | ||
1726 | do_time_wait: | |
1727 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { | |
9469c7b4 | 1728 | inet_twsk_put(inet_twsk(sk)); |
1da177e4 LT |
1729 | goto discard_it; |
1730 | } | |
1731 | ||
1732 | if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) { | |
63231bdd | 1733 | TCP_INC_STATS_BH(net, TCP_MIB_INERRS); |
9469c7b4 | 1734 | inet_twsk_put(inet_twsk(sk)); |
1da177e4 LT |
1735 | goto discard_it; |
1736 | } | |
9469c7b4 | 1737 | switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { |
1da177e4 | 1738 | case TCP_TW_SYN: { |
c346dca1 | 1739 | struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev), |
c67499c0 | 1740 | &tcp_hashinfo, |
eddc9ec5 | 1741 | iph->daddr, th->dest, |
463c84b9 | 1742 | inet_iif(skb)); |
1da177e4 | 1743 | if (sk2) { |
9469c7b4 YH |
1744 | inet_twsk_deschedule(inet_twsk(sk), &tcp_death_row); |
1745 | inet_twsk_put(inet_twsk(sk)); | |
1da177e4 LT |
1746 | sk = sk2; |
1747 | goto process; | |
1748 | } | |
1749 | /* Fall through to ACK */ | |
1750 | } | |
1751 | case TCP_TW_ACK: | |
1752 | tcp_v4_timewait_ack(sk, skb); | |
1753 | break; | |
1754 | case TCP_TW_RST: | |
1755 | goto no_tcp_socket; | |
1756 | case TCP_TW_SUCCESS:; | |
1757 | } | |
1758 | goto discard_it; | |
1759 | } | |
1760 | ||
3f419d2d | 1761 | struct inet_peer *tcp_v4_get_peer(struct sock *sk, bool *release_it) |
1da177e4 | 1762 | { |
3f419d2d | 1763 | struct rtable *rt = (struct rtable *) __sk_dst_get(sk); |
1da177e4 | 1764 | struct inet_sock *inet = inet_sk(sk); |
3f419d2d | 1765 | struct inet_peer *peer; |
1da177e4 | 1766 | |
c720c7e8 | 1767 | if (!rt || rt->rt_dst != inet->inet_daddr) { |
b534ecf1 | 1768 | peer = inet_getpeer_v4(inet->inet_daddr, 1); |
3f419d2d | 1769 | *release_it = true; |
1da177e4 LT |
1770 | } else { |
1771 | if (!rt->peer) | |
1772 | rt_bind_peer(rt, 1); | |
1773 | peer = rt->peer; | |
3f419d2d | 1774 | *release_it = false; |
1da177e4 LT |
1775 | } |
1776 | ||
3f419d2d | 1777 | return peer; |
1da177e4 | 1778 | } |
3f419d2d | 1779 | EXPORT_SYMBOL(tcp_v4_get_peer); |
1da177e4 | 1780 | |
ccb7c410 | 1781 | void *tcp_v4_tw_get_peer(struct sock *sk) |
1da177e4 | 1782 | { |
ccb7c410 | 1783 | struct inet_timewait_sock *tw = inet_twsk(sk); |
1da177e4 | 1784 | |
ccb7c410 | 1785 | return inet_getpeer_v4(tw->tw_daddr, 1); |
1da177e4 | 1786 | } |
ccb7c410 DM |
1787 | EXPORT_SYMBOL(tcp_v4_tw_get_peer); |
1788 | ||
1789 | static struct timewait_sock_ops tcp_timewait_sock_ops = { | |
1790 | .twsk_obj_size = sizeof(struct tcp_timewait_sock), | |
1791 | .twsk_unique = tcp_twsk_unique, | |
1792 | .twsk_destructor= tcp_twsk_destructor, | |
1793 | .twsk_getpeer = tcp_v4_tw_get_peer, | |
1794 | }; | |
1da177e4 | 1795 | |
3b401a81 | 1796 | const struct inet_connection_sock_af_ops ipv4_specific = { |
543d9cfe ACM |
1797 | .queue_xmit = ip_queue_xmit, |
1798 | .send_check = tcp_v4_send_check, | |
1799 | .rebuild_header = inet_sk_rebuild_header, | |
1800 | .conn_request = tcp_v4_conn_request, | |
1801 | .syn_recv_sock = tcp_v4_syn_recv_sock, | |
3f419d2d | 1802 | .get_peer = tcp_v4_get_peer, |
543d9cfe ACM |
1803 | .net_header_len = sizeof(struct iphdr), |
1804 | .setsockopt = ip_setsockopt, | |
1805 | .getsockopt = ip_getsockopt, | |
1806 | .addr2sockaddr = inet_csk_addr2sockaddr, | |
1807 | .sockaddr_len = sizeof(struct sockaddr_in), | |
ab1e0a13 | 1808 | .bind_conflict = inet_csk_bind_conflict, |
3fdadf7d | 1809 | #ifdef CONFIG_COMPAT |
543d9cfe ACM |
1810 | .compat_setsockopt = compat_ip_setsockopt, |
1811 | .compat_getsockopt = compat_ip_getsockopt, | |
3fdadf7d | 1812 | #endif |
1da177e4 | 1813 | }; |
4bc2f18b | 1814 | EXPORT_SYMBOL(ipv4_specific); |
1da177e4 | 1815 | |
cfb6eeb4 | 1816 | #ifdef CONFIG_TCP_MD5SIG |
b2e4b3de | 1817 | static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = { |
cfb6eeb4 | 1818 | .md5_lookup = tcp_v4_md5_lookup, |
49a72dfb | 1819 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
cfb6eeb4 YH |
1820 | .md5_add = tcp_v4_md5_add_func, |
1821 | .md5_parse = tcp_v4_parse_md5_keys, | |
cfb6eeb4 | 1822 | }; |
b6332e6c | 1823 | #endif |
cfb6eeb4 | 1824 | |
1da177e4 LT |
1825 | /* NOTE: A lot of things set to zero explicitly by call to |
1826 | * sk_alloc() so need not be done here. | |
1827 | */ | |
1828 | static int tcp_v4_init_sock(struct sock *sk) | |
1829 | { | |
6687e988 | 1830 | struct inet_connection_sock *icsk = inet_csk(sk); |
1da177e4 LT |
1831 | struct tcp_sock *tp = tcp_sk(sk); |
1832 | ||
1833 | skb_queue_head_init(&tp->out_of_order_queue); | |
1834 | tcp_init_xmit_timers(sk); | |
1835 | tcp_prequeue_init(tp); | |
1836 | ||
6687e988 | 1837 | icsk->icsk_rto = TCP_TIMEOUT_INIT; |
1da177e4 LT |
1838 | tp->mdev = TCP_TIMEOUT_INIT; |
1839 | ||
1840 | /* So many TCP implementations out there (incorrectly) count the | |
1841 | * initial SYN frame in their delayed-ACK and congestion control | |
1842 | * algorithms that we must have the following bandaid to talk | |
1843 | * efficiently to them. -DaveM | |
1844 | */ | |
1845 | tp->snd_cwnd = 2; | |
1846 | ||
1847 | /* See draft-stevens-tcpca-spec-01 for discussion of the | |
1848 | * initialization of these values. | |
1849 | */ | |
0b6a05c1 | 1850 | tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; |
1da177e4 | 1851 | tp->snd_cwnd_clamp = ~0; |
bee7ca9e | 1852 | tp->mss_cache = TCP_MSS_DEFAULT; |
1da177e4 LT |
1853 | |
1854 | tp->reordering = sysctl_tcp_reordering; | |
6687e988 | 1855 | icsk->icsk_ca_ops = &tcp_init_congestion_ops; |
1da177e4 LT |
1856 | |
1857 | sk->sk_state = TCP_CLOSE; | |
1858 | ||
1859 | sk->sk_write_space = sk_stream_write_space; | |
1860 | sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); | |
1861 | ||
8292a17a | 1862 | icsk->icsk_af_ops = &ipv4_specific; |
d83d8461 | 1863 | icsk->icsk_sync_mss = tcp_sync_mss; |
cfb6eeb4 YH |
1864 | #ifdef CONFIG_TCP_MD5SIG |
1865 | tp->af_specific = &tcp_sock_ipv4_specific; | |
1866 | #endif | |
1da177e4 | 1867 | |
435cf559 WAS |
1868 | /* TCP Cookie Transactions */ |
1869 | if (sysctl_tcp_cookie_size > 0) { | |
1870 | /* Default, cookies without s_data_payload. */ | |
1871 | tp->cookie_values = | |
1872 | kzalloc(sizeof(*tp->cookie_values), | |
1873 | sk->sk_allocation); | |
1874 | if (tp->cookie_values != NULL) | |
1875 | kref_init(&tp->cookie_values->kref); | |
1876 | } | |
1877 | /* Presumed zeroed, in order of appearance: | |
1878 | * cookie_in_always, cookie_out_never, | |
1879 | * s_data_constant, s_data_in, s_data_out | |
1880 | */ | |
1da177e4 LT |
1881 | sk->sk_sndbuf = sysctl_tcp_wmem[1]; |
1882 | sk->sk_rcvbuf = sysctl_tcp_rmem[1]; | |
1883 | ||
eb4dea58 | 1884 | local_bh_disable(); |
1748376b | 1885 | percpu_counter_inc(&tcp_sockets_allocated); |
eb4dea58 | 1886 | local_bh_enable(); |
1da177e4 LT |
1887 | |
1888 | return 0; | |
1889 | } | |
1890 | ||
7d06b2e0 | 1891 | void tcp_v4_destroy_sock(struct sock *sk) |
1da177e4 LT |
1892 | { |
1893 | struct tcp_sock *tp = tcp_sk(sk); | |
1894 | ||
1895 | tcp_clear_xmit_timers(sk); | |
1896 | ||
6687e988 | 1897 | tcp_cleanup_congestion_control(sk); |
317a76f9 | 1898 | |
1da177e4 | 1899 | /* Cleanup up the write buffer. */ |
fe067e8a | 1900 | tcp_write_queue_purge(sk); |
1da177e4 LT |
1901 | |
1902 | /* Cleans up our, hopefully empty, out_of_order_queue. */ | |
e905a9ed | 1903 | __skb_queue_purge(&tp->out_of_order_queue); |
1da177e4 | 1904 | |
cfb6eeb4 YH |
1905 | #ifdef CONFIG_TCP_MD5SIG |
1906 | /* Clean up the MD5 key list, if any */ | |
1907 | if (tp->md5sig_info) { | |
1908 | tcp_v4_clear_md5_list(sk); | |
1909 | kfree(tp->md5sig_info); | |
1910 | tp->md5sig_info = NULL; | |
1911 | } | |
1912 | #endif | |
1913 | ||
1a2449a8 CL |
1914 | #ifdef CONFIG_NET_DMA |
1915 | /* Cleans up our sk_async_wait_queue */ | |
e905a9ed | 1916 | __skb_queue_purge(&sk->sk_async_wait_queue); |
1a2449a8 CL |
1917 | #endif |
1918 | ||
1da177e4 LT |
1919 | /* Clean prequeue, it must be empty really */ |
1920 | __skb_queue_purge(&tp->ucopy.prequeue); | |
1921 | ||
1922 | /* Clean up a referenced TCP bind bucket. */ | |
463c84b9 | 1923 | if (inet_csk(sk)->icsk_bind_hash) |
ab1e0a13 | 1924 | inet_put_port(sk); |
1da177e4 LT |
1925 | |
1926 | /* | |
1927 | * If sendmsg cached page exists, toss it. | |
1928 | */ | |
1929 | if (sk->sk_sndmsg_page) { | |
1930 | __free_page(sk->sk_sndmsg_page); | |
1931 | sk->sk_sndmsg_page = NULL; | |
1932 | } | |
1933 | ||
435cf559 WAS |
1934 | /* TCP Cookie Transactions */ |
1935 | if (tp->cookie_values != NULL) { | |
1936 | kref_put(&tp->cookie_values->kref, | |
1937 | tcp_cookie_values_release); | |
1938 | tp->cookie_values = NULL; | |
1939 | } | |
1940 | ||
1748376b | 1941 | percpu_counter_dec(&tcp_sockets_allocated); |
1da177e4 | 1942 | } |
1da177e4 LT |
1943 | EXPORT_SYMBOL(tcp_v4_destroy_sock); |
1944 | ||
1945 | #ifdef CONFIG_PROC_FS | |
1946 | /* Proc filesystem TCP sock list dumping. */ | |
1947 | ||
3ab5aee7 | 1948 | static inline struct inet_timewait_sock *tw_head(struct hlist_nulls_head *head) |
1da177e4 | 1949 | { |
3ab5aee7 | 1950 | return hlist_nulls_empty(head) ? NULL : |
8feaf0c0 | 1951 | list_entry(head->first, struct inet_timewait_sock, tw_node); |
1da177e4 LT |
1952 | } |
1953 | ||
8feaf0c0 | 1954 | static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw) |
1da177e4 | 1955 | { |
3ab5aee7 ED |
1956 | return !is_a_nulls(tw->tw_node.next) ? |
1957 | hlist_nulls_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL; | |
1da177e4 LT |
1958 | } |
1959 | ||
a8b690f9 TH |
1960 | /* |
1961 | * Get next listener socket follow cur. If cur is NULL, get first socket | |
1962 | * starting from bucket given in st->bucket; when st->bucket is zero the | |
1963 | * very first socket in the hash table is returned. | |
1964 | */ | |
1da177e4 LT |
1965 | static void *listening_get_next(struct seq_file *seq, void *cur) |
1966 | { | |
463c84b9 | 1967 | struct inet_connection_sock *icsk; |
c25eb3bf | 1968 | struct hlist_nulls_node *node; |
1da177e4 | 1969 | struct sock *sk = cur; |
5caea4ea | 1970 | struct inet_listen_hashbucket *ilb; |
5799de0b | 1971 | struct tcp_iter_state *st = seq->private; |
a4146b1b | 1972 | struct net *net = seq_file_net(seq); |
1da177e4 LT |
1973 | |
1974 | if (!sk) { | |
a8b690f9 | 1975 | ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
5caea4ea | 1976 | spin_lock_bh(&ilb->lock); |
c25eb3bf | 1977 | sk = sk_nulls_head(&ilb->head); |
a8b690f9 | 1978 | st->offset = 0; |
1da177e4 LT |
1979 | goto get_sk; |
1980 | } | |
5caea4ea | 1981 | ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
1da177e4 | 1982 | ++st->num; |
a8b690f9 | 1983 | ++st->offset; |
1da177e4 LT |
1984 | |
1985 | if (st->state == TCP_SEQ_STATE_OPENREQ) { | |
60236fdd | 1986 | struct request_sock *req = cur; |
1da177e4 | 1987 | |
72a3effa | 1988 | icsk = inet_csk(st->syn_wait_sk); |
1da177e4 LT |
1989 | req = req->dl_next; |
1990 | while (1) { | |
1991 | while (req) { | |
bdccc4ca | 1992 | if (req->rsk_ops->family == st->family) { |
1da177e4 LT |
1993 | cur = req; |
1994 | goto out; | |
1995 | } | |
1996 | req = req->dl_next; | |
1997 | } | |
72a3effa | 1998 | if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries) |
1da177e4 LT |
1999 | break; |
2000 | get_req: | |
463c84b9 | 2001 | req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket]; |
1da177e4 | 2002 | } |
1bde5ac4 | 2003 | sk = sk_nulls_next(st->syn_wait_sk); |
1da177e4 | 2004 | st->state = TCP_SEQ_STATE_LISTENING; |
463c84b9 | 2005 | read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
1da177e4 | 2006 | } else { |
e905a9ed | 2007 | icsk = inet_csk(sk); |
463c84b9 ACM |
2008 | read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
2009 | if (reqsk_queue_len(&icsk->icsk_accept_queue)) | |
1da177e4 | 2010 | goto start_req; |
463c84b9 | 2011 | read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
1bde5ac4 | 2012 | sk = sk_nulls_next(sk); |
1da177e4 LT |
2013 | } |
2014 | get_sk: | |
c25eb3bf | 2015 | sk_nulls_for_each_from(sk, node) { |
8475ef9f PE |
2016 | if (!net_eq(sock_net(sk), net)) |
2017 | continue; | |
2018 | if (sk->sk_family == st->family) { | |
1da177e4 LT |
2019 | cur = sk; |
2020 | goto out; | |
2021 | } | |
e905a9ed | 2022 | icsk = inet_csk(sk); |
463c84b9 ACM |
2023 | read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
2024 | if (reqsk_queue_len(&icsk->icsk_accept_queue)) { | |
1da177e4 LT |
2025 | start_req: |
2026 | st->uid = sock_i_uid(sk); | |
2027 | st->syn_wait_sk = sk; | |
2028 | st->state = TCP_SEQ_STATE_OPENREQ; | |
2029 | st->sbucket = 0; | |
2030 | goto get_req; | |
2031 | } | |
463c84b9 | 2032 | read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); |
1da177e4 | 2033 | } |
5caea4ea | 2034 | spin_unlock_bh(&ilb->lock); |
a8b690f9 | 2035 | st->offset = 0; |
0f7ff927 | 2036 | if (++st->bucket < INET_LHTABLE_SIZE) { |
5caea4ea ED |
2037 | ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
2038 | spin_lock_bh(&ilb->lock); | |
c25eb3bf | 2039 | sk = sk_nulls_head(&ilb->head); |
1da177e4 LT |
2040 | goto get_sk; |
2041 | } | |
2042 | cur = NULL; | |
2043 | out: | |
2044 | return cur; | |
2045 | } | |
2046 | ||
2047 | static void *listening_get_idx(struct seq_file *seq, loff_t *pos) | |
2048 | { | |
a8b690f9 TH |
2049 | struct tcp_iter_state *st = seq->private; |
2050 | void *rc; | |
2051 | ||
2052 | st->bucket = 0; | |
2053 | st->offset = 0; | |
2054 | rc = listening_get_next(seq, NULL); | |
1da177e4 LT |
2055 | |
2056 | while (rc && *pos) { | |
2057 | rc = listening_get_next(seq, rc); | |
2058 | --*pos; | |
2059 | } | |
2060 | return rc; | |
2061 | } | |
2062 | ||
6eac5604 AK |
2063 | static inline int empty_bucket(struct tcp_iter_state *st) |
2064 | { | |
3ab5aee7 ED |
2065 | return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain) && |
2066 | hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].twchain); | |
6eac5604 AK |
2067 | } |
2068 | ||
a8b690f9 TH |
2069 | /* |
2070 | * Get first established socket starting from bucket given in st->bucket. | |
2071 | * If st->bucket is zero, the very first socket in the hash is returned. | |
2072 | */ | |
1da177e4 LT |
2073 | static void *established_get_first(struct seq_file *seq) |
2074 | { | |
5799de0b | 2075 | struct tcp_iter_state *st = seq->private; |
a4146b1b | 2076 | struct net *net = seq_file_net(seq); |
1da177e4 LT |
2077 | void *rc = NULL; |
2078 | ||
a8b690f9 TH |
2079 | st->offset = 0; |
2080 | for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) { | |
1da177e4 | 2081 | struct sock *sk; |
3ab5aee7 | 2082 | struct hlist_nulls_node *node; |
8feaf0c0 | 2083 | struct inet_timewait_sock *tw; |
9db66bdc | 2084 | spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket); |
1da177e4 | 2085 | |
6eac5604 AK |
2086 | /* Lockless fast path for the common case of empty buckets */ |
2087 | if (empty_bucket(st)) | |
2088 | continue; | |
2089 | ||
9db66bdc | 2090 | spin_lock_bh(lock); |
3ab5aee7 | 2091 | sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) { |
f40c8174 | 2092 | if (sk->sk_family != st->family || |
878628fb | 2093 | !net_eq(sock_net(sk), net)) { |
1da177e4 LT |
2094 | continue; |
2095 | } | |
2096 | rc = sk; | |
2097 | goto out; | |
2098 | } | |
2099 | st->state = TCP_SEQ_STATE_TIME_WAIT; | |
8feaf0c0 | 2100 | inet_twsk_for_each(tw, node, |
dbca9b27 | 2101 | &tcp_hashinfo.ehash[st->bucket].twchain) { |
28518fc1 | 2102 | if (tw->tw_family != st->family || |
878628fb | 2103 | !net_eq(twsk_net(tw), net)) { |
1da177e4 LT |
2104 | continue; |
2105 | } | |
2106 | rc = tw; | |
2107 | goto out; | |
2108 | } | |
9db66bdc | 2109 | spin_unlock_bh(lock); |
1da177e4 LT |
2110 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2111 | } | |
2112 | out: | |
2113 | return rc; | |
2114 | } | |
2115 | ||
2116 | static void *established_get_next(struct seq_file *seq, void *cur) | |
2117 | { | |
2118 | struct sock *sk = cur; | |
8feaf0c0 | 2119 | struct inet_timewait_sock *tw; |
3ab5aee7 | 2120 | struct hlist_nulls_node *node; |
5799de0b | 2121 | struct tcp_iter_state *st = seq->private; |
a4146b1b | 2122 | struct net *net = seq_file_net(seq); |
1da177e4 LT |
2123 | |
2124 | ++st->num; | |
a8b690f9 | 2125 | ++st->offset; |
1da177e4 LT |
2126 | |
2127 | if (st->state == TCP_SEQ_STATE_TIME_WAIT) { | |
2128 | tw = cur; | |
2129 | tw = tw_next(tw); | |
2130 | get_tw: | |
878628fb | 2131 | while (tw && (tw->tw_family != st->family || !net_eq(twsk_net(tw), net))) { |
1da177e4 LT |
2132 | tw = tw_next(tw); |
2133 | } | |
2134 | if (tw) { | |
2135 | cur = tw; | |
2136 | goto out; | |
2137 | } | |
9db66bdc | 2138 | spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); |
1da177e4 LT |
2139 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2140 | ||
6eac5604 | 2141 | /* Look for next non empty bucket */ |
a8b690f9 | 2142 | st->offset = 0; |
f373b53b | 2143 | while (++st->bucket <= tcp_hashinfo.ehash_mask && |
6eac5604 AK |
2144 | empty_bucket(st)) |
2145 | ; | |
f373b53b | 2146 | if (st->bucket > tcp_hashinfo.ehash_mask) |
6eac5604 AK |
2147 | return NULL; |
2148 | ||
9db66bdc | 2149 | spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); |
3ab5aee7 | 2150 | sk = sk_nulls_head(&tcp_hashinfo.ehash[st->bucket].chain); |
1da177e4 | 2151 | } else |
3ab5aee7 | 2152 | sk = sk_nulls_next(sk); |
1da177e4 | 2153 | |
3ab5aee7 | 2154 | sk_nulls_for_each_from(sk, node) { |
878628fb | 2155 | if (sk->sk_family == st->family && net_eq(sock_net(sk), net)) |
1da177e4 LT |
2156 | goto found; |
2157 | } | |
2158 | ||
2159 | st->state = TCP_SEQ_STATE_TIME_WAIT; | |
dbca9b27 | 2160 | tw = tw_head(&tcp_hashinfo.ehash[st->bucket].twchain); |
1da177e4 LT |
2161 | goto get_tw; |
2162 | found: | |
2163 | cur = sk; | |
2164 | out: | |
2165 | return cur; | |
2166 | } | |
2167 | ||
2168 | static void *established_get_idx(struct seq_file *seq, loff_t pos) | |
2169 | { | |
a8b690f9 TH |
2170 | struct tcp_iter_state *st = seq->private; |
2171 | void *rc; | |
2172 | ||
2173 | st->bucket = 0; | |
2174 | rc = established_get_first(seq); | |
1da177e4 LT |
2175 | |
2176 | while (rc && pos) { | |
2177 | rc = established_get_next(seq, rc); | |
2178 | --pos; | |
7174259e | 2179 | } |
1da177e4 LT |
2180 | return rc; |
2181 | } | |
2182 | ||
2183 | static void *tcp_get_idx(struct seq_file *seq, loff_t pos) | |
2184 | { | |
2185 | void *rc; | |
5799de0b | 2186 | struct tcp_iter_state *st = seq->private; |
1da177e4 | 2187 | |
1da177e4 LT |
2188 | st->state = TCP_SEQ_STATE_LISTENING; |
2189 | rc = listening_get_idx(seq, &pos); | |
2190 | ||
2191 | if (!rc) { | |
1da177e4 LT |
2192 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
2193 | rc = established_get_idx(seq, pos); | |
2194 | } | |
2195 | ||
2196 | return rc; | |
2197 | } | |
2198 | ||
a8b690f9 TH |
2199 | static void *tcp_seek_last_pos(struct seq_file *seq) |
2200 | { | |
2201 | struct tcp_iter_state *st = seq->private; | |
2202 | int offset = st->offset; | |
2203 | int orig_num = st->num; | |
2204 | void *rc = NULL; | |
2205 | ||
2206 | switch (st->state) { | |
2207 | case TCP_SEQ_STATE_OPENREQ: | |
2208 | case TCP_SEQ_STATE_LISTENING: | |
2209 | if (st->bucket >= INET_LHTABLE_SIZE) | |
2210 | break; | |
2211 | st->state = TCP_SEQ_STATE_LISTENING; | |
2212 | rc = listening_get_next(seq, NULL); | |
2213 | while (offset-- && rc) | |
2214 | rc = listening_get_next(seq, rc); | |
2215 | if (rc) | |
2216 | break; | |
2217 | st->bucket = 0; | |
2218 | /* Fallthrough */ | |
2219 | case TCP_SEQ_STATE_ESTABLISHED: | |
2220 | case TCP_SEQ_STATE_TIME_WAIT: | |
2221 | st->state = TCP_SEQ_STATE_ESTABLISHED; | |
2222 | if (st->bucket > tcp_hashinfo.ehash_mask) | |
2223 | break; | |
2224 | rc = established_get_first(seq); | |
2225 | while (offset-- && rc) | |
2226 | rc = established_get_next(seq, rc); | |
2227 | } | |
2228 | ||
2229 | st->num = orig_num; | |
2230 | ||
2231 | return rc; | |
2232 | } | |
2233 | ||
1da177e4 LT |
2234 | static void *tcp_seq_start(struct seq_file *seq, loff_t *pos) |
2235 | { | |
5799de0b | 2236 | struct tcp_iter_state *st = seq->private; |
a8b690f9 TH |
2237 | void *rc; |
2238 | ||
2239 | if (*pos && *pos == st->last_pos) { | |
2240 | rc = tcp_seek_last_pos(seq); | |
2241 | if (rc) | |
2242 | goto out; | |
2243 | } | |
2244 | ||
1da177e4 LT |
2245 | st->state = TCP_SEQ_STATE_LISTENING; |
2246 | st->num = 0; | |
a8b690f9 TH |
2247 | st->bucket = 0; |
2248 | st->offset = 0; | |
2249 | rc = *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
2250 | ||
2251 | out: | |
2252 | st->last_pos = *pos; | |
2253 | return rc; | |
1da177e4 LT |
2254 | } |
2255 | ||
2256 | static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2257 | { | |
a8b690f9 | 2258 | struct tcp_iter_state *st = seq->private; |
1da177e4 | 2259 | void *rc = NULL; |
1da177e4 LT |
2260 | |
2261 | if (v == SEQ_START_TOKEN) { | |
2262 | rc = tcp_get_idx(seq, 0); | |
2263 | goto out; | |
2264 | } | |
1da177e4 LT |
2265 | |
2266 | switch (st->state) { | |
2267 | case TCP_SEQ_STATE_OPENREQ: | |
2268 | case TCP_SEQ_STATE_LISTENING: | |
2269 | rc = listening_get_next(seq, v); | |
2270 | if (!rc) { | |
1da177e4 | 2271 | st->state = TCP_SEQ_STATE_ESTABLISHED; |
a8b690f9 TH |
2272 | st->bucket = 0; |
2273 | st->offset = 0; | |
1da177e4 LT |
2274 | rc = established_get_first(seq); |
2275 | } | |
2276 | break; | |
2277 | case TCP_SEQ_STATE_ESTABLISHED: | |
2278 | case TCP_SEQ_STATE_TIME_WAIT: | |
2279 | rc = established_get_next(seq, v); | |
2280 | break; | |
2281 | } | |
2282 | out: | |
2283 | ++*pos; | |
a8b690f9 | 2284 | st->last_pos = *pos; |
1da177e4 LT |
2285 | return rc; |
2286 | } | |
2287 | ||
2288 | static void tcp_seq_stop(struct seq_file *seq, void *v) | |
2289 | { | |
5799de0b | 2290 | struct tcp_iter_state *st = seq->private; |
1da177e4 LT |
2291 | |
2292 | switch (st->state) { | |
2293 | case TCP_SEQ_STATE_OPENREQ: | |
2294 | if (v) { | |
463c84b9 ACM |
2295 | struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk); |
2296 | read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); | |
1da177e4 LT |
2297 | } |
2298 | case TCP_SEQ_STATE_LISTENING: | |
2299 | if (v != SEQ_START_TOKEN) | |
5caea4ea | 2300 | spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock); |
1da177e4 LT |
2301 | break; |
2302 | case TCP_SEQ_STATE_TIME_WAIT: | |
2303 | case TCP_SEQ_STATE_ESTABLISHED: | |
2304 | if (v) | |
9db66bdc | 2305 | spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); |
1da177e4 LT |
2306 | break; |
2307 | } | |
2308 | } | |
2309 | ||
2310 | static int tcp_seq_open(struct inode *inode, struct file *file) | |
2311 | { | |
2312 | struct tcp_seq_afinfo *afinfo = PDE(inode)->data; | |
1da177e4 | 2313 | struct tcp_iter_state *s; |
52d6f3f1 | 2314 | int err; |
1da177e4 | 2315 | |
52d6f3f1 DL |
2316 | err = seq_open_net(inode, file, &afinfo->seq_ops, |
2317 | sizeof(struct tcp_iter_state)); | |
2318 | if (err < 0) | |
2319 | return err; | |
f40c8174 | 2320 | |
52d6f3f1 | 2321 | s = ((struct seq_file *)file->private_data)->private; |
1da177e4 | 2322 | s->family = afinfo->family; |
a8b690f9 | 2323 | s->last_pos = 0; |
f40c8174 DL |
2324 | return 0; |
2325 | } | |
2326 | ||
6f8b13bc | 2327 | int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo) |
1da177e4 LT |
2328 | { |
2329 | int rc = 0; | |
2330 | struct proc_dir_entry *p; | |
2331 | ||
68fcadd1 DL |
2332 | afinfo->seq_fops.open = tcp_seq_open; |
2333 | afinfo->seq_fops.read = seq_read; | |
2334 | afinfo->seq_fops.llseek = seq_lseek; | |
2335 | afinfo->seq_fops.release = seq_release_net; | |
7174259e | 2336 | |
9427c4b3 DL |
2337 | afinfo->seq_ops.start = tcp_seq_start; |
2338 | afinfo->seq_ops.next = tcp_seq_next; | |
2339 | afinfo->seq_ops.stop = tcp_seq_stop; | |
2340 | ||
84841c3c DL |
2341 | p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, |
2342 | &afinfo->seq_fops, afinfo); | |
2343 | if (!p) | |
1da177e4 LT |
2344 | rc = -ENOMEM; |
2345 | return rc; | |
2346 | } | |
4bc2f18b | 2347 | EXPORT_SYMBOL(tcp_proc_register); |
1da177e4 | 2348 | |
6f8b13bc | 2349 | void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo) |
1da177e4 | 2350 | { |
6f8b13bc | 2351 | proc_net_remove(net, afinfo->name); |
1da177e4 | 2352 | } |
4bc2f18b | 2353 | EXPORT_SYMBOL(tcp_proc_unregister); |
1da177e4 | 2354 | |
60236fdd | 2355 | static void get_openreq4(struct sock *sk, struct request_sock *req, |
5e659e4c | 2356 | struct seq_file *f, int i, int uid, int *len) |
1da177e4 | 2357 | { |
2e6599cb | 2358 | const struct inet_request_sock *ireq = inet_rsk(req); |
1da177e4 LT |
2359 | int ttd = req->expires - jiffies; |
2360 | ||
5e659e4c PE |
2361 | seq_printf(f, "%4d: %08X:%04X %08X:%04X" |
2362 | " %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p%n", | |
1da177e4 | 2363 | i, |
2e6599cb | 2364 | ireq->loc_addr, |
c720c7e8 | 2365 | ntohs(inet_sk(sk)->inet_sport), |
2e6599cb ACM |
2366 | ireq->rmt_addr, |
2367 | ntohs(ireq->rmt_port), | |
1da177e4 LT |
2368 | TCP_SYN_RECV, |
2369 | 0, 0, /* could print option size, but that is af dependent. */ | |
2370 | 1, /* timers active (only the expire timer) */ | |
2371 | jiffies_to_clock_t(ttd), | |
2372 | req->retrans, | |
2373 | uid, | |
2374 | 0, /* non standard timer */ | |
2375 | 0, /* open_requests have no inode */ | |
2376 | atomic_read(&sk->sk_refcnt), | |
5e659e4c PE |
2377 | req, |
2378 | len); | |
1da177e4 LT |
2379 | } |
2380 | ||
5e659e4c | 2381 | static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len) |
1da177e4 LT |
2382 | { |
2383 | int timer_active; | |
2384 | unsigned long timer_expires; | |
cf4c6bf8 IJ |
2385 | struct tcp_sock *tp = tcp_sk(sk); |
2386 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
2387 | struct inet_sock *inet = inet_sk(sk); | |
c720c7e8 ED |
2388 | __be32 dest = inet->inet_daddr; |
2389 | __be32 src = inet->inet_rcv_saddr; | |
2390 | __u16 destp = ntohs(inet->inet_dport); | |
2391 | __u16 srcp = ntohs(inet->inet_sport); | |
49d09007 | 2392 | int rx_queue; |
1da177e4 | 2393 | |
463c84b9 | 2394 | if (icsk->icsk_pending == ICSK_TIME_RETRANS) { |
1da177e4 | 2395 | timer_active = 1; |
463c84b9 ACM |
2396 | timer_expires = icsk->icsk_timeout; |
2397 | } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { | |
1da177e4 | 2398 | timer_active = 4; |
463c84b9 | 2399 | timer_expires = icsk->icsk_timeout; |
cf4c6bf8 | 2400 | } else if (timer_pending(&sk->sk_timer)) { |
1da177e4 | 2401 | timer_active = 2; |
cf4c6bf8 | 2402 | timer_expires = sk->sk_timer.expires; |
1da177e4 LT |
2403 | } else { |
2404 | timer_active = 0; | |
2405 | timer_expires = jiffies; | |
2406 | } | |
2407 | ||
49d09007 ED |
2408 | if (sk->sk_state == TCP_LISTEN) |
2409 | rx_queue = sk->sk_ack_backlog; | |
2410 | else | |
2411 | /* | |
2412 | * because we dont lock socket, we might find a transient negative value | |
2413 | */ | |
2414 | rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0); | |
2415 | ||
5e659e4c | 2416 | seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX " |
7be87351 | 2417 | "%08X %5d %8d %lu %d %p %lu %lu %u %u %d%n", |
cf4c6bf8 | 2418 | i, src, srcp, dest, destp, sk->sk_state, |
47da8ee6 | 2419 | tp->write_seq - tp->snd_una, |
49d09007 | 2420 | rx_queue, |
1da177e4 LT |
2421 | timer_active, |
2422 | jiffies_to_clock_t(timer_expires - jiffies), | |
463c84b9 | 2423 | icsk->icsk_retransmits, |
cf4c6bf8 | 2424 | sock_i_uid(sk), |
6687e988 | 2425 | icsk->icsk_probes_out, |
cf4c6bf8 IJ |
2426 | sock_i_ino(sk), |
2427 | atomic_read(&sk->sk_refcnt), sk, | |
7be87351 SH |
2428 | jiffies_to_clock_t(icsk->icsk_rto), |
2429 | jiffies_to_clock_t(icsk->icsk_ack.ato), | |
463c84b9 | 2430 | (icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong, |
1da177e4 | 2431 | tp->snd_cwnd, |
0b6a05c1 | 2432 | tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh, |
5e659e4c | 2433 | len); |
1da177e4 LT |
2434 | } |
2435 | ||
7174259e | 2436 | static void get_timewait4_sock(struct inet_timewait_sock *tw, |
5e659e4c | 2437 | struct seq_file *f, int i, int *len) |
1da177e4 | 2438 | { |
23f33c2d | 2439 | __be32 dest, src; |
1da177e4 LT |
2440 | __u16 destp, srcp; |
2441 | int ttd = tw->tw_ttd - jiffies; | |
2442 | ||
2443 | if (ttd < 0) | |
2444 | ttd = 0; | |
2445 | ||
2446 | dest = tw->tw_daddr; | |
2447 | src = tw->tw_rcv_saddr; | |
2448 | destp = ntohs(tw->tw_dport); | |
2449 | srcp = ntohs(tw->tw_sport); | |
2450 | ||
5e659e4c PE |
2451 | seq_printf(f, "%4d: %08X:%04X %08X:%04X" |
2452 | " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p%n", | |
1da177e4 LT |
2453 | i, src, srcp, dest, destp, tw->tw_substate, 0, 0, |
2454 | 3, jiffies_to_clock_t(ttd), 0, 0, 0, 0, | |
5e659e4c | 2455 | atomic_read(&tw->tw_refcnt), tw, len); |
1da177e4 LT |
2456 | } |
2457 | ||
2458 | #define TMPSZ 150 | |
2459 | ||
2460 | static int tcp4_seq_show(struct seq_file *seq, void *v) | |
2461 | { | |
5799de0b | 2462 | struct tcp_iter_state *st; |
5e659e4c | 2463 | int len; |
1da177e4 LT |
2464 | |
2465 | if (v == SEQ_START_TOKEN) { | |
2466 | seq_printf(seq, "%-*s\n", TMPSZ - 1, | |
2467 | " sl local_address rem_address st tx_queue " | |
2468 | "rx_queue tr tm->when retrnsmt uid timeout " | |
2469 | "inode"); | |
2470 | goto out; | |
2471 | } | |
2472 | st = seq->private; | |
2473 | ||
2474 | switch (st->state) { | |
2475 | case TCP_SEQ_STATE_LISTENING: | |
2476 | case TCP_SEQ_STATE_ESTABLISHED: | |
5e659e4c | 2477 | get_tcp4_sock(v, seq, st->num, &len); |
1da177e4 LT |
2478 | break; |
2479 | case TCP_SEQ_STATE_OPENREQ: | |
5e659e4c | 2480 | get_openreq4(st->syn_wait_sk, v, seq, st->num, st->uid, &len); |
1da177e4 LT |
2481 | break; |
2482 | case TCP_SEQ_STATE_TIME_WAIT: | |
5e659e4c | 2483 | get_timewait4_sock(v, seq, st->num, &len); |
1da177e4 LT |
2484 | break; |
2485 | } | |
5e659e4c | 2486 | seq_printf(seq, "%*s\n", TMPSZ - 1 - len, ""); |
1da177e4 LT |
2487 | out: |
2488 | return 0; | |
2489 | } | |
2490 | ||
1da177e4 | 2491 | static struct tcp_seq_afinfo tcp4_seq_afinfo = { |
1da177e4 LT |
2492 | .name = "tcp", |
2493 | .family = AF_INET, | |
5f4472c5 DL |
2494 | .seq_fops = { |
2495 | .owner = THIS_MODULE, | |
2496 | }, | |
9427c4b3 DL |
2497 | .seq_ops = { |
2498 | .show = tcp4_seq_show, | |
2499 | }, | |
1da177e4 LT |
2500 | }; |
2501 | ||
2c8c1e72 | 2502 | static int __net_init tcp4_proc_init_net(struct net *net) |
757764f6 PE |
2503 | { |
2504 | return tcp_proc_register(net, &tcp4_seq_afinfo); | |
2505 | } | |
2506 | ||
2c8c1e72 | 2507 | static void __net_exit tcp4_proc_exit_net(struct net *net) |
757764f6 PE |
2508 | { |
2509 | tcp_proc_unregister(net, &tcp4_seq_afinfo); | |
2510 | } | |
2511 | ||
2512 | static struct pernet_operations tcp4_net_ops = { | |
2513 | .init = tcp4_proc_init_net, | |
2514 | .exit = tcp4_proc_exit_net, | |
2515 | }; | |
2516 | ||
1da177e4 LT |
2517 | int __init tcp4_proc_init(void) |
2518 | { | |
757764f6 | 2519 | return register_pernet_subsys(&tcp4_net_ops); |
1da177e4 LT |
2520 | } |
2521 | ||
2522 | void tcp4_proc_exit(void) | |
2523 | { | |
757764f6 | 2524 | unregister_pernet_subsys(&tcp4_net_ops); |
1da177e4 LT |
2525 | } |
2526 | #endif /* CONFIG_PROC_FS */ | |
2527 | ||
bf296b12 HX |
2528 | struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb) |
2529 | { | |
36e7b1b8 | 2530 | struct iphdr *iph = skb_gro_network_header(skb); |
bf296b12 HX |
2531 | |
2532 | switch (skb->ip_summed) { | |
2533 | case CHECKSUM_COMPLETE: | |
86911732 | 2534 | if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr, |
bf296b12 HX |
2535 | skb->csum)) { |
2536 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
2537 | break; | |
2538 | } | |
2539 | ||
2540 | /* fall through */ | |
2541 | case CHECKSUM_NONE: | |
2542 | NAPI_GRO_CB(skb)->flush = 1; | |
2543 | return NULL; | |
2544 | } | |
2545 | ||
2546 | return tcp_gro_receive(head, skb); | |
2547 | } | |
bf296b12 HX |
2548 | |
2549 | int tcp4_gro_complete(struct sk_buff *skb) | |
2550 | { | |
2551 | struct iphdr *iph = ip_hdr(skb); | |
2552 | struct tcphdr *th = tcp_hdr(skb); | |
2553 | ||
2554 | th->check = ~tcp_v4_check(skb->len - skb_transport_offset(skb), | |
2555 | iph->saddr, iph->daddr, 0); | |
2556 | skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; | |
2557 | ||
2558 | return tcp_gro_complete(skb); | |
2559 | } | |
bf296b12 | 2560 | |
1da177e4 LT |
2561 | struct proto tcp_prot = { |
2562 | .name = "TCP", | |
2563 | .owner = THIS_MODULE, | |
2564 | .close = tcp_close, | |
2565 | .connect = tcp_v4_connect, | |
2566 | .disconnect = tcp_disconnect, | |
463c84b9 | 2567 | .accept = inet_csk_accept, |
1da177e4 LT |
2568 | .ioctl = tcp_ioctl, |
2569 | .init = tcp_v4_init_sock, | |
2570 | .destroy = tcp_v4_destroy_sock, | |
2571 | .shutdown = tcp_shutdown, | |
2572 | .setsockopt = tcp_setsockopt, | |
2573 | .getsockopt = tcp_getsockopt, | |
1da177e4 | 2574 | .recvmsg = tcp_recvmsg, |
7ba42910 CG |
2575 | .sendmsg = tcp_sendmsg, |
2576 | .sendpage = tcp_sendpage, | |
1da177e4 | 2577 | .backlog_rcv = tcp_v4_do_rcv, |
ab1e0a13 ACM |
2578 | .hash = inet_hash, |
2579 | .unhash = inet_unhash, | |
2580 | .get_port = inet_csk_get_port, | |
1da177e4 LT |
2581 | .enter_memory_pressure = tcp_enter_memory_pressure, |
2582 | .sockets_allocated = &tcp_sockets_allocated, | |
0a5578cf | 2583 | .orphan_count = &tcp_orphan_count, |
1da177e4 LT |
2584 | .memory_allocated = &tcp_memory_allocated, |
2585 | .memory_pressure = &tcp_memory_pressure, | |
2586 | .sysctl_mem = sysctl_tcp_mem, | |
2587 | .sysctl_wmem = sysctl_tcp_wmem, | |
2588 | .sysctl_rmem = sysctl_tcp_rmem, | |
2589 | .max_header = MAX_TCP_HEADER, | |
2590 | .obj_size = sizeof(struct tcp_sock), | |
3ab5aee7 | 2591 | .slab_flags = SLAB_DESTROY_BY_RCU, |
6d6ee43e | 2592 | .twsk_prot = &tcp_timewait_sock_ops, |
60236fdd | 2593 | .rsk_prot = &tcp_request_sock_ops, |
39d8cda7 | 2594 | .h.hashinfo = &tcp_hashinfo, |
7ba42910 | 2595 | .no_autobind = true, |
543d9cfe ACM |
2596 | #ifdef CONFIG_COMPAT |
2597 | .compat_setsockopt = compat_tcp_setsockopt, | |
2598 | .compat_getsockopt = compat_tcp_getsockopt, | |
2599 | #endif | |
1da177e4 | 2600 | }; |
4bc2f18b | 2601 | EXPORT_SYMBOL(tcp_prot); |
1da177e4 | 2602 | |
046ee902 DL |
2603 | |
2604 | static int __net_init tcp_sk_init(struct net *net) | |
2605 | { | |
2606 | return inet_ctl_sock_create(&net->ipv4.tcp_sock, | |
2607 | PF_INET, SOCK_RAW, IPPROTO_TCP, net); | |
2608 | } | |
2609 | ||
2610 | static void __net_exit tcp_sk_exit(struct net *net) | |
2611 | { | |
2612 | inet_ctl_sock_destroy(net->ipv4.tcp_sock); | |
b099ce26 EB |
2613 | } |
2614 | ||
2615 | static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list) | |
2616 | { | |
2617 | inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET); | |
046ee902 DL |
2618 | } |
2619 | ||
2620 | static struct pernet_operations __net_initdata tcp_sk_ops = { | |
b099ce26 EB |
2621 | .init = tcp_sk_init, |
2622 | .exit = tcp_sk_exit, | |
2623 | .exit_batch = tcp_sk_exit_batch, | |
046ee902 DL |
2624 | }; |
2625 | ||
9b0f976f | 2626 | void __init tcp_v4_init(void) |
1da177e4 | 2627 | { |
5caea4ea | 2628 | inet_hashinfo_init(&tcp_hashinfo); |
6a1b3054 | 2629 | if (register_pernet_subsys(&tcp_sk_ops)) |
1da177e4 | 2630 | panic("Failed to create the TCP control socket.\n"); |
1da177e4 | 2631 | } |