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Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001/*
2 * net/dccp/minisocks.c
3 *
4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070013#include <linux/dccp.h>
Gerrit Renker8a73cd02006-11-10 12:32:01 -020014#include <linux/kernel.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070015#include <linux/skbuff.h>
16#include <linux/timer.h>
17
18#include <net/sock.h>
19#include <net/xfrm.h>
20#include <net/inet_timewait_sock.h>
21
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070022#include "ackvec.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070023#include "ccid.h"
24#include "dccp.h"
Andrea Bittauafe00252006-03-20 17:43:56 -080025#include "feat.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070026
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070027struct inet_timewait_death_row dccp_death_row = {
28 .sysctl_max_tw_buckets = NR_FILE * 2,
29 .period = DCCP_TIMEWAIT_LEN / INET_TWDR_TWKILL_SLOTS,
Milind Arun Choudhary4ef8d0a2007-04-26 01:37:44 -070030 .death_lock = __SPIN_LOCK_UNLOCKED(dccp_death_row.death_lock),
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070031 .hashinfo = &dccp_hashinfo,
32 .tw_timer = TIMER_INITIALIZER(inet_twdr_hangman, 0,
33 (unsigned long)&dccp_death_row),
34 .twkill_work = __WORK_INITIALIZER(dccp_death_row.twkill_work,
David Howellsc4028952006-11-22 14:57:56 +000035 inet_twdr_twkill_work),
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070036/* Short-time timewait calendar */
37
38 .twcal_hand = -1,
39 .twcal_timer = TIMER_INITIALIZER(inet_twdr_twcal_tick, 0,
40 (unsigned long)&dccp_death_row),
41};
42
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -080043EXPORT_SYMBOL_GPL(dccp_death_row);
44
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070045void dccp_time_wait(struct sock *sk, int state, int timeo)
46{
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070047 struct inet_timewait_sock *tw = NULL;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070048
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070049 if (dccp_death_row.tw_count < dccp_death_row.sysctl_max_tw_buckets)
50 tw = inet_twsk_alloc(sk, state);
51
52 if (tw != NULL) {
53 const struct inet_connection_sock *icsk = inet_csk(sk);
54 const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080055#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
56 if (tw->tw_family == PF_INET6) {
57 const struct ipv6_pinfo *np = inet6_sk(sk);
58 struct inet6_timewait_sock *tw6;
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070059
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080060 tw->tw_ipv6_offset = inet6_tw_offset(sk->sk_prot);
61 tw6 = inet6_twsk((struct sock *)tw);
62 ipv6_addr_copy(&tw6->tw_v6_daddr, &np->daddr);
63 ipv6_addr_copy(&tw6->tw_v6_rcv_saddr, &np->rcv_saddr);
64 tw->tw_ipv6only = np->ipv6only;
65 }
66#endif
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070067 /* Linkage updates. */
68 __inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
69
70 /* Get the TIME_WAIT timeout firing. */
71 if (timeo < rto)
72 timeo = rto;
73
74 tw->tw_timeout = DCCP_TIMEWAIT_LEN;
75 if (state == DCCP_TIME_WAIT)
76 timeo = DCCP_TIMEWAIT_LEN;
77
78 inet_twsk_schedule(tw, &dccp_death_row, timeo,
79 DCCP_TIMEWAIT_LEN);
80 inet_twsk_put(tw);
81 } else {
82 /* Sorry, if we're out of memory, just CLOSE this
83 * socket up. We've got bigger problems than
84 * non-graceful socket closings.
85 */
Gerrit Renker59348b12006-11-20 18:39:23 -020086 DCCP_WARN("time wait bucket table overflow\n");
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070087 }
88
89 dccp_done(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070090}
91
92struct sock *dccp_create_openreq_child(struct sock *sk,
93 const struct request_sock *req,
94 const struct sk_buff *skb)
95{
96 /*
97 * Step 3: Process LISTEN state
98 *
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -020099 * (* Generate a new socket and switch to that socket *)
100 * Set S := new socket for this port pair
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700101 */
102 struct sock *newsk = inet_csk_clone(sk, req, GFP_ATOMIC);
103
104 if (newsk != NULL) {
105 const struct dccp_request_sock *dreq = dccp_rsk(req);
Gerrit Renker99c72ce2007-03-06 14:24:44 -0800106 struct inet_connection_sock *newicsk = inet_csk(newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700107 struct dccp_sock *newdp = dccp_sk(newsk);
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800108 struct dccp_minisock *newdmsk = dccp_msk(newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700109
Arnaldo Carvalho de Melo67e6b622005-09-16 16:58:40 -0700110 newdp->dccps_role = DCCP_ROLE_SERVER;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700111 newdp->dccps_hc_rx_ackvec = NULL;
Arnaldo Carvalho de Melo67e6b622005-09-16 16:58:40 -0700112 newdp->dccps_service_list = NULL;
113 newdp->dccps_service = dreq->dreq_service;
114 newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
Arnaldo Carvalho de Melob0e56782005-09-09 02:38:35 -0300115 do_gettimeofday(&newdp->dccps_epoch);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700116
Andrea Bittauafe00252006-03-20 17:43:56 -0800117 if (dccp_feat_clone(sk, newsk))
118 goto out_free;
119
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800120 if (newdmsk->dccpms_send_ack_vector) {
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700121 newdp->dccps_hc_rx_ackvec =
Arnaldo Carvalho de Melo7400d782006-03-20 17:15:42 -0800122 dccp_ackvec_alloc(GFP_ATOMIC);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700123 if (unlikely(newdp->dccps_hc_rx_ackvec == NULL))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700124 goto out_free;
125 }
126
Arnaldo Carvalho de Melo91f0ebf2006-03-20 19:21:44 -0800127 newdp->dccps_hc_rx_ccid =
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800128 ccid_hc_rx_new(newdmsk->dccpms_rx_ccid,
Arnaldo Carvalho de Melo91f0ebf2006-03-20 19:21:44 -0800129 newsk, GFP_ATOMIC);
130 newdp->dccps_hc_tx_ccid =
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800131 ccid_hc_tx_new(newdmsk->dccpms_tx_ccid,
Arnaldo Carvalho de Melo91f0ebf2006-03-20 19:21:44 -0800132 newsk, GFP_ATOMIC);
133 if (unlikely(newdp->dccps_hc_rx_ccid == NULL ||
134 newdp->dccps_hc_tx_ccid == NULL)) {
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700135 dccp_ackvec_free(newdp->dccps_hc_rx_ackvec);
Arnaldo Carvalho de Melo91f0ebf2006-03-20 19:21:44 -0800136 ccid_hc_rx_delete(newdp->dccps_hc_rx_ccid, newsk);
137 ccid_hc_tx_delete(newdp->dccps_hc_tx_ccid, newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700138out_free:
139 /* It is still raw copy of parent, so invalidate
140 * destructor and make plain sk_free() */
141 newsk->sk_destruct = NULL;
142 sk_free(newsk);
143 return NULL;
144 }
145
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700146 /*
147 * Step 3: Process LISTEN state
148 *
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200149 * Choose S.ISS (initial seqno) or set from Init Cookies
150 * Initialize S.GAR := S.ISS
151 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700152 */
153
154 /* See dccp_v4_conn_request */
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800155 newdmsk->dccpms_sequence_window = req->rcv_wnd;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700156
157 newdp->dccps_gar = newdp->dccps_isr = dreq->dreq_isr;
158 dccp_update_gsr(newsk, dreq->dreq_isr);
159
160 newdp->dccps_iss = dreq->dreq_iss;
161 dccp_update_gss(newsk, dreq->dreq_iss);
162
Arnaldo Carvalho de Melo03ace392005-08-21 05:36:45 -0300163 /*
164 * SWL and AWL are initially adjusted so that they are not less than
165 * the initial Sequence Numbers received and sent, respectively:
166 * SWL := max(GSR + 1 - floor(W/4), ISR),
167 * AWL := max(GSS - W' + 1, ISS).
168 * These adjustments MUST be applied only at the beginning of the
169 * connection.
170 */
171 dccp_set_seqno(&newdp->dccps_swl,
172 max48(newdp->dccps_swl, newdp->dccps_isr));
173 dccp_set_seqno(&newdp->dccps_awl,
174 max48(newdp->dccps_awl, newdp->dccps_iss));
175
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700176 dccp_init_xmit_timers(newsk);
177
178 DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);
179 }
180 return newsk;
181}
182
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800183EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
184
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200185/*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700186 * Process an incoming packet for RESPOND sockets represented
187 * as an request_sock.
188 */
189struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
190 struct request_sock *req,
191 struct request_sock **prev)
192{
193 struct sock *child = NULL;
194
195 /* Check for retransmitted REQUEST */
196 if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
Gerrit Renkere11d9d32006-11-13 13:12:07 -0200197 struct dccp_request_sock *dreq = dccp_rsk(req);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700198
Gerrit Renkere11d9d32006-11-13 13:12:07 -0200199 if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_isr)) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700200 dccp_pr_debug("Retransmitted REQUEST\n");
Gerrit Renkere11d9d32006-11-13 13:12:07 -0200201 dreq->dreq_isr = DCCP_SKB_CB(skb)->dccpd_seq;
202 /*
203 * Send another RESPONSE packet
204 * To protect against Request floods, increment retrans
205 * counter (backoff, monitored by dccp_response_timer).
206 */
207 req->retrans++;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700208 req->rsk_ops->rtx_syn_ack(sk, req, NULL);
209 }
210 /* Network Duplicate, discard packet */
211 return NULL;
212 }
213
214 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
215
216 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK &&
217 dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK)
218 goto drop;
219
220 /* Invalid ACK */
221 if (DCCP_SKB_CB(skb)->dccpd_ack_seq != dccp_rsk(req)->dreq_iss) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300222 dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "
223 "dreq_iss=%llu\n",
David S. Millerf6ccf552005-08-09 20:27:14 -0700224 (unsigned long long)
225 DCCP_SKB_CB(skb)->dccpd_ack_seq,
226 (unsigned long long)
227 dccp_rsk(req)->dreq_iss);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700228 goto drop;
229 }
230
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800231 child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700232 if (child == NULL)
233 goto listen_overflow;
234
235 /* FIXME: deal with options */
236
237 inet_csk_reqsk_queue_unlink(sk, req, prev);
238 inet_csk_reqsk_queue_removed(sk, req);
239 inet_csk_reqsk_queue_add(sk, req, child);
240out:
241 return child;
242listen_overflow:
243 dccp_pr_debug("listen_overflow!\n");
244 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
245drop:
246 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800247 req->rsk_ops->send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700248
249 inet_csk_reqsk_queue_drop(sk, req, prev);
250 goto out;
251}
252
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800253EXPORT_SYMBOL_GPL(dccp_check_req);
254
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700255/*
256 * Queue segment on the new socket if the new socket is active,
257 * otherwise we just shortcircuit this and continue with
258 * the new socket.
259 */
260int dccp_child_process(struct sock *parent, struct sock *child,
261 struct sk_buff *skb)
262{
263 int ret = 0;
264 const int state = child->sk_state;
265
266 if (!sock_owned_by_user(child)) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300267 ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb),
268 skb->len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700269
270 /* Wakeup parent, send SIGIO */
271 if (state == DCCP_RESPOND && child->sk_state != state)
272 parent->sk_data_ready(parent, 0);
273 } else {
274 /* Alas, it is possible again, because we do lookup
275 * in main socket hash table and lock on listening
276 * socket does not protect us more.
277 */
278 sk_add_backlog(child, skb);
279 }
280
281 bh_unlock_sock(child);
282 sock_put(child);
283 return ret;
284}
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800285
286EXPORT_SYMBOL_GPL(dccp_child_process);
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200287
288void dccp_reqsk_send_ack(struct sk_buff *skb, struct request_sock *rsk)
289{
Gerrit Renker59348b12006-11-20 18:39:23 -0200290 DCCP_BUG("DCCP-ACK packets are never sent in LISTEN/RESPOND state");
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200291}
292
293EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack);
Gerrit Renkercf557922006-11-10 16:08:37 -0200294
295void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb)
296{
297 inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
298 inet_rsk(req)->acked = 0;
Gerrit Renkerafb0a342006-11-13 13:25:41 -0200299 req->rcv_wnd = sysctl_dccp_feat_sequence_window;
Gerrit Renkercf557922006-11-10 16:08:37 -0200300}
301
302EXPORT_SYMBOL_GPL(dccp_reqsk_init);