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[pv_ops_mirror.git] / net / dccp / minisocks.c
blob9045438d6b36953cd26b0b2edb12226336838745
1 /*
2 * net/dccp/minisocks.c
4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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.
13 #include <linux/dccp.h>
14 #include <linux/skbuff.h>
15 #include <linux/timer.h>
17 #include <net/sock.h>
18 #include <net/xfrm.h>
19 #include <net/inet_timewait_sock.h>
21 #include "ackvec.h"
22 #include "ccid.h"
23 #include "dccp.h"
24 #include "feat.h"
26 struct 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 */
38 .twcal_hand = -1,
39 .twcal_timer = TIMER_INITIALIZER(inet_twdr_twcal_tick, 0,
40 (unsigned long)&dccp_death_row),
43 EXPORT_SYMBOL_GPL(dccp_death_row);
45 void dccp_time_wait(struct sock *sk, int state, int timeo)
47 struct inet_timewait_sock *tw = NULL;
49 if (dccp_death_row.tw_count < dccp_death_row.sysctl_max_tw_buckets)
50 tw = inet_twsk_alloc(sk, state);
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);
55 #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;
60 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;
66 #endif
67 /* Linkage updates. */
68 __inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
70 /* Get the TIME_WAIT timeout firing. */
71 if (timeo < rto)
72 timeo = rto;
74 tw->tw_timeout = DCCP_TIMEWAIT_LEN;
75 if (state == DCCP_TIME_WAIT)
76 timeo = DCCP_TIMEWAIT_LEN;
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.
86 LIMIT_NETDEBUG(KERN_INFO "DCCP: time wait bucket "
87 "table overflow\n");
90 dccp_done(sk);
93 struct sock *dccp_create_openreq_child(struct sock *sk,
94 const struct request_sock *req,
95 const struct sk_buff *skb)
98 * Step 3: Process LISTEN state
100 * // Generate a new socket and switch to that socket
101 * Set S := new socket for this port pair
103 struct sock *newsk = inet_csk_clone(sk, req, GFP_ATOMIC);
105 if (newsk != NULL) {
106 const struct dccp_request_sock *dreq = dccp_rsk(req);
107 struct inet_connection_sock *newicsk = inet_csk(sk);
108 struct dccp_sock *newdp = dccp_sk(newsk);
109 struct dccp_minisock *newdmsk = dccp_msk(newsk);
111 newdp->dccps_role = DCCP_ROLE_SERVER;
112 newdp->dccps_hc_rx_ackvec = NULL;
113 newdp->dccps_service_list = NULL;
114 newdp->dccps_service = dreq->dreq_service;
115 newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
116 do_gettimeofday(&newdp->dccps_epoch);
118 if (dccp_feat_clone(sk, newsk))
119 goto out_free;
121 if (newdmsk->dccpms_send_ack_vector) {
122 newdp->dccps_hc_rx_ackvec =
123 dccp_ackvec_alloc(GFP_ATOMIC);
124 if (unlikely(newdp->dccps_hc_rx_ackvec == NULL))
125 goto out_free;
128 newdp->dccps_hc_rx_ccid =
129 ccid_hc_rx_new(newdmsk->dccpms_rx_ccid,
130 newsk, GFP_ATOMIC);
131 newdp->dccps_hc_tx_ccid =
132 ccid_hc_tx_new(newdmsk->dccpms_tx_ccid,
133 newsk, GFP_ATOMIC);
134 if (unlikely(newdp->dccps_hc_rx_ccid == NULL ||
135 newdp->dccps_hc_tx_ccid == NULL)) {
136 dccp_ackvec_free(newdp->dccps_hc_rx_ackvec);
137 ccid_hc_rx_delete(newdp->dccps_hc_rx_ccid, newsk);
138 ccid_hc_tx_delete(newdp->dccps_hc_tx_ccid, newsk);
139 out_free:
140 /* It is still raw copy of parent, so invalidate
141 * destructor and make plain sk_free() */
142 newsk->sk_destruct = NULL;
143 sk_free(newsk);
144 return NULL;
148 * Step 3: Process LISTEN state
150 * Choose S.ISS (initial seqno) or set from Init Cookie
151 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init
152 * Cookie
155 /* See dccp_v4_conn_request */
156 newdmsk->dccpms_sequence_window = req->rcv_wnd;
158 newdp->dccps_gar = newdp->dccps_isr = dreq->dreq_isr;
159 dccp_update_gsr(newsk, dreq->dreq_isr);
161 newdp->dccps_iss = dreq->dreq_iss;
162 dccp_update_gss(newsk, dreq->dreq_iss);
165 * SWL and AWL are initially adjusted so that they are not less than
166 * the initial Sequence Numbers received and sent, respectively:
167 * SWL := max(GSR + 1 - floor(W/4), ISR),
168 * AWL := max(GSS - W' + 1, ISS).
169 * These adjustments MUST be applied only at the beginning of the
170 * connection.
172 dccp_set_seqno(&newdp->dccps_swl,
173 max48(newdp->dccps_swl, newdp->dccps_isr));
174 dccp_set_seqno(&newdp->dccps_awl,
175 max48(newdp->dccps_awl, newdp->dccps_iss));
177 dccp_init_xmit_timers(newsk);
179 DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);
181 return newsk;
184 EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
187 * Process an incoming packet for RESPOND sockets represented
188 * as an request_sock.
190 struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
191 struct request_sock *req,
192 struct request_sock **prev)
194 struct sock *child = NULL;
196 /* Check for retransmitted REQUEST */
197 if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
198 if (after48(DCCP_SKB_CB(skb)->dccpd_seq,
199 dccp_rsk(req)->dreq_isr)) {
200 struct dccp_request_sock *dreq = dccp_rsk(req);
202 dccp_pr_debug("Retransmitted REQUEST\n");
203 /* Send another RESPONSE packet */
204 dccp_set_seqno(&dreq->dreq_iss, dreq->dreq_iss + 1);
205 dccp_set_seqno(&dreq->dreq_isr,
206 DCCP_SKB_CB(skb)->dccpd_seq);
207 req->rsk_ops->rtx_syn_ack(sk, req, NULL);
209 /* Network Duplicate, discard packet */
210 return NULL;
213 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
215 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK &&
216 dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK)
217 goto drop;
219 /* Invalid ACK */
220 if (DCCP_SKB_CB(skb)->dccpd_ack_seq != dccp_rsk(req)->dreq_iss) {
221 dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "
222 "dreq_iss=%llu\n",
223 (unsigned long long)
224 DCCP_SKB_CB(skb)->dccpd_ack_seq,
225 (unsigned long long)
226 dccp_rsk(req)->dreq_iss);
227 goto drop;
230 child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
231 if (child == NULL)
232 goto listen_overflow;
234 /* FIXME: deal with options */
236 inet_csk_reqsk_queue_unlink(sk, req, prev);
237 inet_csk_reqsk_queue_removed(sk, req);
238 inet_csk_reqsk_queue_add(sk, req, child);
239 out:
240 return child;
241 listen_overflow:
242 dccp_pr_debug("listen_overflow!\n");
243 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
244 drop:
245 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)
246 req->rsk_ops->send_reset(skb);
248 inet_csk_reqsk_queue_drop(sk, req, prev);
249 goto out;
252 EXPORT_SYMBOL_GPL(dccp_check_req);
255 * Queue segment on the new socket if the new socket is active,
256 * otherwise we just shortcircuit this and continue with
257 * the new socket.
259 int dccp_child_process(struct sock *parent, struct sock *child,
260 struct sk_buff *skb)
262 int ret = 0;
263 const int state = child->sk_state;
265 if (!sock_owned_by_user(child)) {
266 ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb),
267 skb->len);
269 /* Wakeup parent, send SIGIO */
270 if (state == DCCP_RESPOND && child->sk_state != state)
271 parent->sk_data_ready(parent, 0);
272 } else {
273 /* Alas, it is possible again, because we do lookup
274 * in main socket hash table and lock on listening
275 * socket does not protect us more.
277 sk_add_backlog(child, skb);
280 bh_unlock_sock(child);
281 sock_put(child);
282 return ret;
285 EXPORT_SYMBOL_GPL(dccp_child_process);