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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
Gerrit Renker451bc042007-10-04 14:43:42 -070045void dccp_minisock_init(struct dccp_minisock *dmsk)
46{
47 dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window;
48 dmsk->dccpms_rx_ccid = sysctl_dccp_feat_rx_ccid;
49 dmsk->dccpms_tx_ccid = sysctl_dccp_feat_tx_ccid;
50 dmsk->dccpms_ack_ratio = sysctl_dccp_feat_ack_ratio;
51 dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector;
52 dmsk->dccpms_send_ndp_count = sysctl_dccp_feat_send_ndp_count;
53}
54
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070055void dccp_time_wait(struct sock *sk, int state, int timeo)
56{
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070057 struct inet_timewait_sock *tw = NULL;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070058
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070059 if (dccp_death_row.tw_count < dccp_death_row.sysctl_max_tw_buckets)
60 tw = inet_twsk_alloc(sk, state);
61
62 if (tw != NULL) {
63 const struct inet_connection_sock *icsk = inet_csk(sk);
64 const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080065#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
66 if (tw->tw_family == PF_INET6) {
67 const struct ipv6_pinfo *np = inet6_sk(sk);
68 struct inet6_timewait_sock *tw6;
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070069
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080070 tw->tw_ipv6_offset = inet6_tw_offset(sk->sk_prot);
71 tw6 = inet6_twsk((struct sock *)tw);
72 ipv6_addr_copy(&tw6->tw_v6_daddr, &np->daddr);
73 ipv6_addr_copy(&tw6->tw_v6_rcv_saddr, &np->rcv_saddr);
74 tw->tw_ipv6only = np->ipv6only;
75 }
76#endif
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070077 /* Linkage updates. */
78 __inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
79
80 /* Get the TIME_WAIT timeout firing. */
81 if (timeo < rto)
82 timeo = rto;
83
84 tw->tw_timeout = DCCP_TIMEWAIT_LEN;
85 if (state == DCCP_TIME_WAIT)
86 timeo = DCCP_TIMEWAIT_LEN;
87
88 inet_twsk_schedule(tw, &dccp_death_row, timeo,
89 DCCP_TIMEWAIT_LEN);
90 inet_twsk_put(tw);
91 } else {
92 /* Sorry, if we're out of memory, just CLOSE this
93 * socket up. We've got bigger problems than
94 * non-graceful socket closings.
95 */
Gerrit Renker59348b12006-11-20 18:39:23 -020096 DCCP_WARN("time wait bucket table overflow\n");
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070097 }
98
99 dccp_done(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700100}
101
102struct sock *dccp_create_openreq_child(struct sock *sk,
103 const struct request_sock *req,
104 const struct sk_buff *skb)
105{
106 /*
107 * Step 3: Process LISTEN state
108 *
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200109 * (* Generate a new socket and switch to that socket *)
110 * Set S := new socket for this port pair
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700111 */
112 struct sock *newsk = inet_csk_clone(sk, req, GFP_ATOMIC);
113
114 if (newsk != NULL) {
115 const struct dccp_request_sock *dreq = dccp_rsk(req);
Gerrit Renker99c72ce2007-03-06 14:24:44 -0800116 struct inet_connection_sock *newicsk = inet_csk(newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700117 struct dccp_sock *newdp = dccp_sk(newsk);
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800118 struct dccp_minisock *newdmsk = dccp_msk(newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700119
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200120 newdp->dccps_role = DCCP_ROLE_SERVER;
121 newdp->dccps_hc_rx_ackvec = NULL;
122 newdp->dccps_service_list = NULL;
123 newdp->dccps_service = dreq->dreq_service;
124 newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
125 newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
126 newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700127
Andrea Bittauafe00252006-03-20 17:43:56 -0800128 if (dccp_feat_clone(sk, newsk))
129 goto out_free;
130
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800131 if (newdmsk->dccpms_send_ack_vector) {
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700132 newdp->dccps_hc_rx_ackvec =
Arnaldo Carvalho de Melo7400d782006-03-20 17:15:42 -0800133 dccp_ackvec_alloc(GFP_ATOMIC);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700134 if (unlikely(newdp->dccps_hc_rx_ackvec == NULL))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700135 goto out_free;
136 }
137
Arnaldo Carvalho de Melo91f0ebf2006-03-20 19:21:44 -0800138 newdp->dccps_hc_rx_ccid =
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800139 ccid_hc_rx_new(newdmsk->dccpms_rx_ccid,
Arnaldo Carvalho de Melo91f0ebf2006-03-20 19:21:44 -0800140 newsk, GFP_ATOMIC);
141 newdp->dccps_hc_tx_ccid =
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800142 ccid_hc_tx_new(newdmsk->dccpms_tx_ccid,
Arnaldo Carvalho de Melo91f0ebf2006-03-20 19:21:44 -0800143 newsk, GFP_ATOMIC);
144 if (unlikely(newdp->dccps_hc_rx_ccid == NULL ||
145 newdp->dccps_hc_tx_ccid == NULL)) {
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700146 dccp_ackvec_free(newdp->dccps_hc_rx_ackvec);
Arnaldo Carvalho de Melo91f0ebf2006-03-20 19:21:44 -0800147 ccid_hc_rx_delete(newdp->dccps_hc_rx_ccid, newsk);
148 ccid_hc_tx_delete(newdp->dccps_hc_tx_ccid, newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700149out_free:
150 /* It is still raw copy of parent, so invalidate
151 * destructor and make plain sk_free() */
152 newsk->sk_destruct = NULL;
153 sk_free(newsk);
154 return NULL;
155 }
156
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700157 /*
158 * Step 3: Process LISTEN state
159 *
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200160 * Choose S.ISS (initial seqno) or set from Init Cookies
161 * Initialize S.GAR := S.ISS
162 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700163 */
164
165 /* See dccp_v4_conn_request */
Arnaldo Carvalho de Meloa4bf3902006-03-20 22:50:58 -0800166 newdmsk->dccpms_sequence_window = req->rcv_wnd;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700167
Gerrit Renkerbe4c7982008-06-11 11:19:10 +0100168 newdp->dccps_gar = newdp->dccps_iss = dreq->dreq_iss;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700169 dccp_update_gss(newsk, dreq->dreq_iss);
170
Gerrit Renkerbe4c7982008-06-11 11:19:10 +0100171 newdp->dccps_isr = dreq->dreq_isr;
172 dccp_update_gsr(newsk, dreq->dreq_isr);
173
Arnaldo Carvalho de Melo03ace392005-08-21 05:36:45 -0300174 /*
175 * SWL and AWL are initially adjusted so that they are not less than
176 * the initial Sequence Numbers received and sent, respectively:
177 * SWL := max(GSR + 1 - floor(W/4), ISR),
178 * AWL := max(GSS - W' + 1, ISS).
179 * These adjustments MUST be applied only at the beginning of the
180 * connection.
181 */
182 dccp_set_seqno(&newdp->dccps_swl,
183 max48(newdp->dccps_swl, newdp->dccps_isr));
184 dccp_set_seqno(&newdp->dccps_awl,
185 max48(newdp->dccps_awl, newdp->dccps_iss));
186
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700187 dccp_init_xmit_timers(newsk);
188
189 DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);
190 }
191 return newsk;
192}
193
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800194EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
195
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200196/*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700197 * Process an incoming packet for RESPOND sockets represented
198 * as an request_sock.
199 */
200struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
201 struct request_sock *req,
202 struct request_sock **prev)
203{
204 struct sock *child = NULL;
Gerrit Renker81096162007-12-13 12:31:26 -0200205 struct dccp_request_sock *dreq = dccp_rsk(req);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700206
207 /* Check for retransmitted REQUEST */
208 if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700209
Gerrit Renkere11d9d32006-11-13 13:12:07 -0200210 if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_isr)) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700211 dccp_pr_debug("Retransmitted REQUEST\n");
Gerrit Renkere11d9d32006-11-13 13:12:07 -0200212 dreq->dreq_isr = DCCP_SKB_CB(skb)->dccpd_seq;
213 /*
214 * Send another RESPONSE packet
215 * To protect against Request floods, increment retrans
216 * counter (backoff, monitored by dccp_response_timer).
217 */
218 req->retrans++;
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800219 req->rsk_ops->rtx_syn_ack(sk, req);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700220 }
221 /* Network Duplicate, discard packet */
222 return NULL;
223 }
224
225 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
226
227 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK &&
228 dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK)
229 goto drop;
230
231 /* Invalid ACK */
Gerrit Renker81096162007-12-13 12:31:26 -0200232 if (DCCP_SKB_CB(skb)->dccpd_ack_seq != dreq->dreq_iss) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300233 dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "
234 "dreq_iss=%llu\n",
David S. Millerf6ccf552005-08-09 20:27:14 -0700235 (unsigned long long)
236 DCCP_SKB_CB(skb)->dccpd_ack_seq,
Gerrit Renker81096162007-12-13 12:31:26 -0200237 (unsigned long long) dreq->dreq_iss);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700238 goto drop;
239 }
240
Gerrit Renker81096162007-12-13 12:31:26 -0200241 if (dccp_parse_options(sk, dreq, skb))
242 goto drop;
243
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800244 child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700245 if (child == NULL)
246 goto listen_overflow;
247
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700248 inet_csk_reqsk_queue_unlink(sk, req, prev);
249 inet_csk_reqsk_queue_removed(sk, req);
250 inet_csk_reqsk_queue_add(sk, req, child);
251out:
252 return child;
253listen_overflow:
254 dccp_pr_debug("listen_overflow!\n");
255 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
256drop:
257 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800258 req->rsk_ops->send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700259
260 inet_csk_reqsk_queue_drop(sk, req, prev);
261 goto out;
262}
263
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800264EXPORT_SYMBOL_GPL(dccp_check_req);
265
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700266/*
267 * Queue segment on the new socket if the new socket is active,
268 * otherwise we just shortcircuit this and continue with
269 * the new socket.
270 */
271int dccp_child_process(struct sock *parent, struct sock *child,
272 struct sk_buff *skb)
273{
274 int ret = 0;
275 const int state = child->sk_state;
276
277 if (!sock_owned_by_user(child)) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300278 ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb),
279 skb->len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700280
281 /* Wakeup parent, send SIGIO */
282 if (state == DCCP_RESPOND && child->sk_state != state)
283 parent->sk_data_ready(parent, 0);
284 } else {
285 /* Alas, it is possible again, because we do lookup
286 * in main socket hash table and lock on listening
287 * socket does not protect us more.
288 */
289 sk_add_backlog(child, skb);
290 }
291
292 bh_unlock_sock(child);
293 sock_put(child);
294 return ret;
295}
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800296
297EXPORT_SYMBOL_GPL(dccp_child_process);
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200298
299void dccp_reqsk_send_ack(struct sk_buff *skb, struct request_sock *rsk)
300{
Gerrit Renker59348b12006-11-20 18:39:23 -0200301 DCCP_BUG("DCCP-ACK packets are never sent in LISTEN/RESPOND state");
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200302}
303
304EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack);
Gerrit Renkercf557922006-11-10 16:08:37 -0200305
306void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb)
307{
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200308 struct dccp_request_sock *dreq = dccp_rsk(req);
309
310 inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
311 inet_rsk(req)->acked = 0;
312 req->rcv_wnd = sysctl_dccp_feat_sequence_window;
313 dreq->dreq_timestamp_echo = 0;
Gerrit Renkercf557922006-11-10 16:08:37 -0200314}
315
316EXPORT_SYMBOL_GPL(dccp_reqsk_init);