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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
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"
25
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070026struct inet_timewait_death_row dccp_death_row = {
27 .sysctl_max_tw_buckets = NR_FILE * 2,
28 .period = DCCP_TIMEWAIT_LEN / INET_TWDR_TWKILL_SLOTS,
29 .death_lock = SPIN_LOCK_UNLOCKED,
30 .hashinfo = &dccp_hashinfo,
31 .tw_timer = TIMER_INITIALIZER(inet_twdr_hangman, 0,
32 (unsigned long)&dccp_death_row),
33 .twkill_work = __WORK_INITIALIZER(dccp_death_row.twkill_work,
34 inet_twdr_twkill_work,
35 &dccp_death_row),
36/* 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 Melo7c657872005-08-09 20:14:34 -070043void dccp_time_wait(struct sock *sk, int state, int timeo)
44{
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070045 struct inet_timewait_sock *tw = NULL;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070046
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070047 if (dccp_death_row.tw_count < dccp_death_row.sysctl_max_tw_buckets)
48 tw = inet_twsk_alloc(sk, state);
49
50 if (tw != NULL) {
51 const struct inet_connection_sock *icsk = inet_csk(sk);
52 const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
53
54 /* Linkage updates. */
55 __inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
56
57 /* Get the TIME_WAIT timeout firing. */
58 if (timeo < rto)
59 timeo = rto;
60
61 tw->tw_timeout = DCCP_TIMEWAIT_LEN;
62 if (state == DCCP_TIME_WAIT)
63 timeo = DCCP_TIMEWAIT_LEN;
64
65 inet_twsk_schedule(tw, &dccp_death_row, timeo,
66 DCCP_TIMEWAIT_LEN);
67 inet_twsk_put(tw);
68 } else {
69 /* Sorry, if we're out of memory, just CLOSE this
70 * socket up. We've got bigger problems than
71 * non-graceful socket closings.
72 */
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -030073 LIMIT_NETDEBUG(KERN_INFO "DCCP: time wait bucket "
74 "table overflow\n");
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070075 }
76
77 dccp_done(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070078}
79
80struct sock *dccp_create_openreq_child(struct sock *sk,
81 const struct request_sock *req,
82 const struct sk_buff *skb)
83{
84 /*
85 * Step 3: Process LISTEN state
86 *
87 * // Generate a new socket and switch to that socket
88 * Set S := new socket for this port pair
89 */
90 struct sock *newsk = inet_csk_clone(sk, req, GFP_ATOMIC);
91
92 if (newsk != NULL) {
93 const struct dccp_request_sock *dreq = dccp_rsk(req);
94 struct inet_connection_sock *newicsk = inet_csk(sk);
95 struct dccp_sock *newdp = dccp_sk(newsk);
96
Arnaldo Carvalho de Melo67e6b622005-09-16 16:58:40 -070097 newdp->dccps_role = DCCP_ROLE_SERVER;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070098 newdp->dccps_hc_rx_ackvec = NULL;
Arnaldo Carvalho de Melo67e6b622005-09-16 16:58:40 -070099 newdp->dccps_service_list = NULL;
100 newdp->dccps_service = dreq->dreq_service;
101 newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
Arnaldo Carvalho de Melob0e56782005-09-09 02:38:35 -0300102 do_gettimeofday(&newdp->dccps_epoch);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700103
104 if (newdp->dccps_options.dccpo_send_ack_vector) {
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700105 newdp->dccps_hc_rx_ackvec =
106 dccp_ackvec_alloc(DCCP_MAX_ACKVEC_LEN,
107 GFP_ATOMIC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700108 /*
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300109 * XXX: We're using the same CCIDs set on the parent,
110 * i.e. sk_clone copied the master sock and left the
111 * CCID pointers for this child, that is why we do the
112 * __ccid_get calls.
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700113 */
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700114 if (unlikely(newdp->dccps_hc_rx_ackvec == NULL))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700115 goto out_free;
116 }
117
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300118 if (unlikely(ccid_hc_rx_init(newdp->dccps_hc_rx_ccid,
119 newsk) != 0 ||
120 ccid_hc_tx_init(newdp->dccps_hc_tx_ccid,
121 newsk) != 0)) {
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700122 dccp_ackvec_free(newdp->dccps_hc_rx_ackvec);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700123 ccid_hc_rx_exit(newdp->dccps_hc_rx_ccid, newsk);
124 ccid_hc_tx_exit(newdp->dccps_hc_tx_ccid, newsk);
125out_free:
126 /* It is still raw copy of parent, so invalidate
127 * destructor and make plain sk_free() */
128 newsk->sk_destruct = NULL;
129 sk_free(newsk);
130 return NULL;
131 }
132
133 __ccid_get(newdp->dccps_hc_rx_ccid);
134 __ccid_get(newdp->dccps_hc_tx_ccid);
135
136 /*
137 * Step 3: Process LISTEN state
138 *
139 * Choose S.ISS (initial seqno) or set from Init Cookie
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300140 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init
141 * Cookie
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700142 */
143
144 /* See dccp_v4_conn_request */
145 newdp->dccps_options.dccpo_sequence_window = req->rcv_wnd;
146
147 newdp->dccps_gar = newdp->dccps_isr = dreq->dreq_isr;
148 dccp_update_gsr(newsk, dreq->dreq_isr);
149
150 newdp->dccps_iss = dreq->dreq_iss;
151 dccp_update_gss(newsk, dreq->dreq_iss);
152
Arnaldo Carvalho de Melo03ace392005-08-21 05:36:45 -0300153 /*
154 * SWL and AWL are initially adjusted so that they are not less than
155 * the initial Sequence Numbers received and sent, respectively:
156 * SWL := max(GSR + 1 - floor(W/4), ISR),
157 * AWL := max(GSS - W' + 1, ISS).
158 * These adjustments MUST be applied only at the beginning of the
159 * connection.
160 */
161 dccp_set_seqno(&newdp->dccps_swl,
162 max48(newdp->dccps_swl, newdp->dccps_isr));
163 dccp_set_seqno(&newdp->dccps_awl,
164 max48(newdp->dccps_awl, newdp->dccps_iss));
165
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700166 dccp_init_xmit_timers(newsk);
167
168 DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);
169 }
170 return newsk;
171}
172
173/*
174 * Process an incoming packet for RESPOND sockets represented
175 * as an request_sock.
176 */
177struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
178 struct request_sock *req,
179 struct request_sock **prev)
180{
181 struct sock *child = NULL;
182
183 /* Check for retransmitted REQUEST */
184 if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300185 if (after48(DCCP_SKB_CB(skb)->dccpd_seq,
186 dccp_rsk(req)->dreq_isr)) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700187 struct dccp_request_sock *dreq = dccp_rsk(req);
188
189 dccp_pr_debug("Retransmitted REQUEST\n");
190 /* Send another RESPONSE packet */
191 dccp_set_seqno(&dreq->dreq_iss, dreq->dreq_iss + 1);
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300192 dccp_set_seqno(&dreq->dreq_isr,
193 DCCP_SKB_CB(skb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700194 req->rsk_ops->rtx_syn_ack(sk, req, NULL);
195 }
196 /* Network Duplicate, discard packet */
197 return NULL;
198 }
199
200 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
201
202 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK &&
203 dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK)
204 goto drop;
205
206 /* Invalid ACK */
207 if (DCCP_SKB_CB(skb)->dccpd_ack_seq != dccp_rsk(req)->dreq_iss) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300208 dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "
209 "dreq_iss=%llu\n",
David S. Millerf6ccf552005-08-09 20:27:14 -0700210 (unsigned long long)
211 DCCP_SKB_CB(skb)->dccpd_ack_seq,
212 (unsigned long long)
213 dccp_rsk(req)->dreq_iss);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700214 goto drop;
215 }
216
217 child = dccp_v4_request_recv_sock(sk, skb, req, NULL);
218 if (child == NULL)
219 goto listen_overflow;
220
221 /* FIXME: deal with options */
222
223 inet_csk_reqsk_queue_unlink(sk, req, prev);
224 inet_csk_reqsk_queue_removed(sk, req);
225 inet_csk_reqsk_queue_add(sk, req, child);
226out:
227 return child;
228listen_overflow:
229 dccp_pr_debug("listen_overflow!\n");
230 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
231drop:
232 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)
233 req->rsk_ops->send_reset(skb);
234
235 inet_csk_reqsk_queue_drop(sk, req, prev);
236 goto out;
237}
238
239/*
240 * Queue segment on the new socket if the new socket is active,
241 * otherwise we just shortcircuit this and continue with
242 * the new socket.
243 */
244int dccp_child_process(struct sock *parent, struct sock *child,
245 struct sk_buff *skb)
246{
247 int ret = 0;
248 const int state = child->sk_state;
249
250 if (!sock_owned_by_user(child)) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300251 ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb),
252 skb->len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700253
254 /* Wakeup parent, send SIGIO */
255 if (state == DCCP_RESPOND && child->sk_state != state)
256 parent->sk_data_ready(parent, 0);
257 } else {
258 /* Alas, it is possible again, because we do lookup
259 * in main socket hash table and lock on listening
260 * socket does not protect us more.
261 */
262 sk_add_backlog(child, skb);
263 }
264
265 bh_unlock_sock(child);
266 sock_put(child);
267 return ret;
268}