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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) {
Gerrit Renker192b27f2008-12-08 01:15:55 -0800105 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);
108
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200109 newdp->dccps_role = DCCP_ROLE_SERVER;
110 newdp->dccps_hc_rx_ackvec = NULL;
111 newdp->dccps_service_list = NULL;
112 newdp->dccps_service = dreq->dreq_service;
113 newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
114 newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
115 newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700116
Gerrit Renkerac757732008-11-04 23:55:49 -0800117 INIT_LIST_HEAD(&newdp->dccps_featneg);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700118 /*
119 * Step 3: Process LISTEN state
120 *
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200121 * Choose S.ISS (initial seqno) or set from Init Cookies
122 * Initialize S.GAR := S.ISS
123 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700124 */
Gerrit Renkerbe4c7982008-06-11 11:19:10 +0100125 newdp->dccps_gar = newdp->dccps_iss = dreq->dreq_iss;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700126 dccp_update_gss(newsk, dreq->dreq_iss);
127
Gerrit Renkerbe4c7982008-06-11 11:19:10 +0100128 newdp->dccps_isr = dreq->dreq_isr;
129 dccp_update_gsr(newsk, dreq->dreq_isr);
130
Arnaldo Carvalho de Melo03ace392005-08-21 05:36:45 -0300131 /*
132 * SWL and AWL are initially adjusted so that they are not less than
133 * the initial Sequence Numbers received and sent, respectively:
134 * SWL := max(GSR + 1 - floor(W/4), ISR),
135 * AWL := max(GSS - W' + 1, ISS).
136 * These adjustments MUST be applied only at the beginning of the
137 * connection.
138 */
139 dccp_set_seqno(&newdp->dccps_swl,
140 max48(newdp->dccps_swl, newdp->dccps_isr));
141 dccp_set_seqno(&newdp->dccps_awl,
142 max48(newdp->dccps_awl, newdp->dccps_iss));
143
Gerrit Renker192b27f2008-12-08 01:15:55 -0800144 /*
145 * Activate features after initialising the sequence numbers,
146 * since CCID initialisation may depend on GSS, ISR, ISS etc.
147 */
148 if (dccp_feat_activate_values(newsk, &dreq->dreq_featneg)) {
149 /* It is still raw copy of parent, so invalidate
150 * destructor and make plain sk_free() */
151 newsk->sk_destruct = NULL;
152 sk_free(newsk);
153 return NULL;
154 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700155 dccp_init_xmit_timers(newsk);
156
157 DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);
158 }
159 return newsk;
160}
161
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800162EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
163
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200164/*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700165 * Process an incoming packet for RESPOND sockets represented
166 * as an request_sock.
167 */
168struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
169 struct request_sock *req,
170 struct request_sock **prev)
171{
172 struct sock *child = NULL;
Gerrit Renker81096162007-12-13 12:31:26 -0200173 struct dccp_request_sock *dreq = dccp_rsk(req);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700174
175 /* Check for retransmitted REQUEST */
176 if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700177
Gerrit Renkere11d9d32006-11-13 13:12:07 -0200178 if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_isr)) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700179 dccp_pr_debug("Retransmitted REQUEST\n");
Gerrit Renkere11d9d32006-11-13 13:12:07 -0200180 dreq->dreq_isr = DCCP_SKB_CB(skb)->dccpd_seq;
181 /*
182 * Send another RESPONSE packet
183 * To protect against Request floods, increment retrans
184 * counter (backoff, monitored by dccp_response_timer).
185 */
186 req->retrans++;
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000187 req->rsk_ops->rtx_syn_ack(sk, req, NULL);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700188 }
189 /* Network Duplicate, discard packet */
190 return NULL;
191 }
192
193 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
194
195 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK &&
196 dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK)
197 goto drop;
198
199 /* Invalid ACK */
Gerrit Renker81096162007-12-13 12:31:26 -0200200 if (DCCP_SKB_CB(skb)->dccpd_ack_seq != dreq->dreq_iss) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300201 dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "
202 "dreq_iss=%llu\n",
David S. Millerf6ccf552005-08-09 20:27:14 -0700203 (unsigned long long)
204 DCCP_SKB_CB(skb)->dccpd_ack_seq,
Gerrit Renker81096162007-12-13 12:31:26 -0200205 (unsigned long long) dreq->dreq_iss);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700206 goto drop;
207 }
208
Gerrit Renker81096162007-12-13 12:31:26 -0200209 if (dccp_parse_options(sk, dreq, skb))
210 goto drop;
211
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800212 child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700213 if (child == NULL)
214 goto listen_overflow;
215
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700216 inet_csk_reqsk_queue_unlink(sk, req, prev);
217 inet_csk_reqsk_queue_removed(sk, req);
218 inet_csk_reqsk_queue_add(sk, req, child);
219out:
220 return child;
221listen_overflow:
222 dccp_pr_debug("listen_overflow!\n");
223 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
224drop:
225 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800226 req->rsk_ops->send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700227
228 inet_csk_reqsk_queue_drop(sk, req, prev);
229 goto out;
230}
231
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800232EXPORT_SYMBOL_GPL(dccp_check_req);
233
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700234/*
235 * Queue segment on the new socket if the new socket is active,
236 * otherwise we just shortcircuit this and continue with
237 * the new socket.
238 */
239int dccp_child_process(struct sock *parent, struct sock *child,
240 struct sk_buff *skb)
241{
242 int ret = 0;
243 const int state = child->sk_state;
244
245 if (!sock_owned_by_user(child)) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300246 ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb),
247 skb->len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700248
249 /* Wakeup parent, send SIGIO */
250 if (state == DCCP_RESPOND && child->sk_state != state)
251 parent->sk_data_ready(parent, 0);
252 } else {
253 /* Alas, it is possible again, because we do lookup
254 * in main socket hash table and lock on listening
255 * socket does not protect us more.
256 */
257 sk_add_backlog(child, skb);
258 }
259
260 bh_unlock_sock(child);
261 sock_put(child);
262 return ret;
263}
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800264
265EXPORT_SYMBOL_GPL(dccp_child_process);
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200266
Gui Jianfeng6edafaa2008-08-06 23:50:04 -0700267void dccp_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
268 struct request_sock *rsk)
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200269{
Gerrit Renker59348b12006-11-20 18:39:23 -0200270 DCCP_BUG("DCCP-ACK packets are never sent in LISTEN/RESPOND state");
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200271}
272
273EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack);
Gerrit Renkercf557922006-11-10 16:08:37 -0200274
Gerrit Renkerac757732008-11-04 23:55:49 -0800275int dccp_reqsk_init(struct request_sock *req,
276 struct dccp_sock const *dp, struct sk_buff const *skb)
Gerrit Renkercf557922006-11-10 16:08:37 -0200277{
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200278 struct dccp_request_sock *dreq = dccp_rsk(req);
279
280 inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
Gerrit Renker944f7502008-10-19 23:36:47 -0700281 inet_rsk(req)->loc_port = dccp_hdr(skb)->dccph_dport;
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200282 inet_rsk(req)->acked = 0;
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200283 dreq->dreq_timestamp_echo = 0;
Gerrit Renkerac757732008-11-04 23:55:49 -0800284
285 /* inherit feature negotiation options from listening socket */
286 return dccp_feat_clone_list(&dp->dccps_featneg, &dreq->dreq_featneg);
Gerrit Renkercf557922006-11-10 16:08:37 -0200287}
288
289EXPORT_SYMBOL_GPL(dccp_reqsk_init);