blob: c0349e5b055158d041f2d4ea61da50f090d94f30 [file] [log] [blame]
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
13#include <linux/config.h>
14#include <linux/dccp.h>
15#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,
30 .death_lock = SPIN_LOCK_UNLOCKED,
31 .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,
35 inet_twdr_twkill_work,
36 &dccp_death_row),
37/* Short-time timewait calendar */
38
39 .twcal_hand = -1,
40 .twcal_timer = TIMER_INITIALIZER(inet_twdr_twcal_tick, 0,
41 (unsigned long)&dccp_death_row),
42};
43
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -080044EXPORT_SYMBOL_GPL(dccp_death_row);
45
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070046void dccp_time_wait(struct sock *sk, int state, int timeo)
47{
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070048 struct inet_timewait_sock *tw = NULL;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070049
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070050 if (dccp_death_row.tw_count < dccp_death_row.sysctl_max_tw_buckets)
51 tw = inet_twsk_alloc(sk, state);
52
53 if (tw != NULL) {
54 const struct inet_connection_sock *icsk = inet_csk(sk);
55 const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080056#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
57 if (tw->tw_family == PF_INET6) {
58 const struct ipv6_pinfo *np = inet6_sk(sk);
59 struct inet6_timewait_sock *tw6;
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070060
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080061 tw->tw_ipv6_offset = inet6_tw_offset(sk->sk_prot);
62 tw6 = inet6_twsk((struct sock *)tw);
63 ipv6_addr_copy(&tw6->tw_v6_daddr, &np->daddr);
64 ipv6_addr_copy(&tw6->tw_v6_rcv_saddr, &np->rcv_saddr);
65 tw->tw_ipv6only = np->ipv6only;
66 }
67#endif
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070068 /* Linkage updates. */
69 __inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
70
71 /* Get the TIME_WAIT timeout firing. */
72 if (timeo < rto)
73 timeo = rto;
74
75 tw->tw_timeout = DCCP_TIMEWAIT_LEN;
76 if (state == DCCP_TIME_WAIT)
77 timeo = DCCP_TIMEWAIT_LEN;
78
79 inet_twsk_schedule(tw, &dccp_death_row, timeo,
80 DCCP_TIMEWAIT_LEN);
81 inet_twsk_put(tw);
82 } else {
83 /* Sorry, if we're out of memory, just CLOSE this
84 * socket up. We've got bigger problems than
85 * non-graceful socket closings.
86 */
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -030087 LIMIT_NETDEBUG(KERN_INFO "DCCP: time wait bucket "
88 "table overflow\n");
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070089 }
90
91 dccp_done(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070092}
93
94struct sock *dccp_create_openreq_child(struct sock *sk,
95 const struct request_sock *req,
96 const struct sk_buff *skb)
97{
98 /*
99 * Step 3: Process LISTEN state
100 *
101 * // Generate a new socket and switch to that socket
102 * Set S := new socket for this port pair
103 */
104 struct sock *newsk = inet_csk_clone(sk, req, GFP_ATOMIC);
105
106 if (newsk != NULL) {
107 const struct dccp_request_sock *dreq = dccp_rsk(req);
108 struct inet_connection_sock *newicsk = inet_csk(sk);
109 struct dccp_sock *newdp = dccp_sk(newsk);
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800110 struct dccp_minisock *newdmsk = dccp_msk(newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700111
Arnaldo Carvalho de Melo67e6b622005-09-16 16:58:40 -0700112 newdp->dccps_role = DCCP_ROLE_SERVER;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700113 newdp->dccps_hc_rx_ackvec = NULL;
Arnaldo Carvalho de Melo67e6b622005-09-16 16:58:40 -0700114 newdp->dccps_service_list = NULL;
115 newdp->dccps_service = dreq->dreq_service;
116 newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
Arnaldo Carvalho de Melob0e56782005-09-09 02:38:35 -0300117 do_gettimeofday(&newdp->dccps_epoch);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700118
Andrea Bittauafe00252006-03-20 17:43:56 -0800119 if (dccp_feat_clone(sk, newsk))
120 goto out_free;
121
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800122 if (newdmsk->dccpms_send_ack_vector) {
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700123 newdp->dccps_hc_rx_ackvec =
Arnaldo Carvalho de Melo7400d782006-03-20 17:15:42 -0800124 dccp_ackvec_alloc(GFP_ATOMIC);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700125 if (unlikely(newdp->dccps_hc_rx_ackvec == NULL))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700126 goto out_free;
127 }
128
Arnaldo Carvalho de Melo91f0ebf2006-03-20 19:21:44 -0800129 newdp->dccps_hc_rx_ccid =
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800130 ccid_hc_rx_new(newdmsk->dccpms_rx_ccid,
Arnaldo Carvalho de Melo91f0ebf2006-03-20 19:21:44 -0800131 newsk, GFP_ATOMIC);
132 newdp->dccps_hc_tx_ccid =
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800133 ccid_hc_tx_new(newdmsk->dccpms_tx_ccid,
Arnaldo Carvalho de Melo91f0ebf2006-03-20 19:21:44 -0800134 newsk, GFP_ATOMIC);
135 if (unlikely(newdp->dccps_hc_rx_ccid == NULL ||
136 newdp->dccps_hc_tx_ccid == NULL)) {
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700137 dccp_ackvec_free(newdp->dccps_hc_rx_ackvec);
Arnaldo Carvalho de Melo91f0ebf2006-03-20 19:21:44 -0800138 ccid_hc_rx_delete(newdp->dccps_hc_rx_ccid, newsk);
139 ccid_hc_tx_delete(newdp->dccps_hc_tx_ccid, newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700140out_free:
141 /* It is still raw copy of parent, so invalidate
142 * destructor and make plain sk_free() */
143 newsk->sk_destruct = NULL;
144 sk_free(newsk);
145 return NULL;
146 }
147
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700148 /*
149 * Step 3: Process LISTEN state
150 *
151 * Choose S.ISS (initial seqno) or set from Init Cookie
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300152 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init
153 * Cookie
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700154 */
155
156 /* See dccp_v4_conn_request */
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800157 newdmsk->dccpms_sequence_window = req->rcv_wnd;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700158
159 newdp->dccps_gar = newdp->dccps_isr = dreq->dreq_isr;
160 dccp_update_gsr(newsk, dreq->dreq_isr);
161
162 newdp->dccps_iss = dreq->dreq_iss;
163 dccp_update_gss(newsk, dreq->dreq_iss);
164
Arnaldo Carvalho de Melo03ace392005-08-21 05:36:45 -0300165 /*
166 * SWL and AWL are initially adjusted so that they are not less than
167 * the initial Sequence Numbers received and sent, respectively:
168 * SWL := max(GSR + 1 - floor(W/4), ISR),
169 * AWL := max(GSS - W' + 1, ISS).
170 * These adjustments MUST be applied only at the beginning of the
171 * connection.
172 */
173 dccp_set_seqno(&newdp->dccps_swl,
174 max48(newdp->dccps_swl, newdp->dccps_isr));
175 dccp_set_seqno(&newdp->dccps_awl,
176 max48(newdp->dccps_awl, newdp->dccps_iss));
177
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700178 dccp_init_xmit_timers(newsk);
179
180 DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);
181 }
182 return newsk;
183}
184
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800185EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
186
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700187/*
188 * Process an incoming packet for RESPOND sockets represented
189 * as an request_sock.
190 */
191struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
192 struct request_sock *req,
193 struct request_sock **prev)
194{
195 struct sock *child = NULL;
196
197 /* Check for retransmitted REQUEST */
198 if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300199 if (after48(DCCP_SKB_CB(skb)->dccpd_seq,
200 dccp_rsk(req)->dreq_isr)) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700201 struct dccp_request_sock *dreq = dccp_rsk(req);
202
203 dccp_pr_debug("Retransmitted REQUEST\n");
204 /* Send another RESPONSE packet */
205 dccp_set_seqno(&dreq->dreq_iss, dreq->dreq_iss + 1);
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300206 dccp_set_seqno(&dreq->dreq_isr,
207 DCCP_SKB_CB(skb)->dccpd_seq);
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)
247 req->rsk_ops->send_reset(skb);
248
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);