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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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/gfp.h>
Gerrit Renker8a73cd02006-11-10 12:32:01 -020015#include <linux/kernel.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070016#include <linux/skbuff.h>
17#include <linux/timer.h>
18
19#include <net/sock.h>
20#include <net/xfrm.h>
21#include <net/inet_timewait_sock.h>
22
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070023#include "ackvec.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070024#include "ccid.h"
25#include "dccp.h"
Andrea Bittauafe00252006-03-20 17:43:56 -080026#include "feat.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070027
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070028struct inet_timewait_death_row dccp_death_row = {
29 .sysctl_max_tw_buckets = NR_FILE * 2,
30 .period = DCCP_TIMEWAIT_LEN / INET_TWDR_TWKILL_SLOTS,
Milind Arun Choudhary4ef8d0a2007-04-26 01:37:44 -070031 .death_lock = __SPIN_LOCK_UNLOCKED(dccp_death_row.death_lock),
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070032 .hashinfo = &dccp_hashinfo,
33 .tw_timer = TIMER_INITIALIZER(inet_twdr_hangman, 0,
34 (unsigned long)&dccp_death_row),
35 .twkill_work = __WORK_INITIALIZER(dccp_death_row.twkill_work,
David Howellsc4028952006-11-22 14:57:56 +000036 inet_twdr_twkill_work),
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070037/* 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);
Eric Dumazetdfd56b82011-12-10 09:48:31 +000056#if IS_ENABLED(CONFIG_IPV6)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080057 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);
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +000063 tw6->tw_v6_daddr = np->daddr;
64 tw6->tw_v6_rcv_saddr = np->rcv_saddr;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080065 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 */
Gerrit Renker59348b12006-11-20 18:39:23 -020087 DCCP_WARN("time wait bucket table overflow\n");
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070088 }
89
90 dccp_done(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070091}
92
93struct sock *dccp_create_openreq_child(struct sock *sk,
94 const struct request_sock *req,
95 const struct sk_buff *skb)
96{
97 /*
98 * Step 3: Process LISTEN state
99 *
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200100 * (* Generate a new socket and switch to that socket *)
101 * Set S := new socket for this port pair
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700102 */
Eric Dumazete56c57d2011-11-08 17:07:07 -0500103 struct sock *newsk = inet_csk_clone_lock(sk, req, GFP_ATOMIC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700104
105 if (newsk != NULL) {
Gerrit Renker192b27f2008-12-08 01:15:55 -0800106 struct dccp_request_sock *dreq = dccp_rsk(req);
Gerrit Renker99c72ce2007-03-06 14:24:44 -0800107 struct inet_connection_sock *newicsk = inet_csk(newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700108 struct dccp_sock *newdp = dccp_sk(newsk);
109
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200110 newdp->dccps_role = DCCP_ROLE_SERVER;
111 newdp->dccps_hc_rx_ackvec = NULL;
112 newdp->dccps_service_list = NULL;
113 newdp->dccps_service = dreq->dreq_service;
114 newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
115 newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
116 newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700117
Gerrit Renkerac757732008-11-04 23:55:49 -0800118 INIT_LIST_HEAD(&newdp->dccps_featneg);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700119 /*
120 * Step 3: Process LISTEN state
121 *
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200122 * Choose S.ISS (initial seqno) or set from Init Cookies
123 * Initialize S.GAR := S.ISS
Gerrit Renker0b53d462010-10-11 20:35:40 +0200124 * Set S.ISR, S.GSR from packet (or Init Cookies)
125 *
126 * Setting AWL/AWH and SWL/SWH happens as part of the feature
127 * activation below, as these windows all depend on the local
128 * and remote Sequence Window feature values (7.5.2).
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700129 */
Samuel Jerof541fb72012-02-26 18:22:02 -0700130 newdp->dccps_iss = dreq->dreq_iss;
131 newdp->dccps_gss = dreq->dreq_gss;
Gerrit Renker0b53d462010-10-11 20:35:40 +0200132 newdp->dccps_gar = newdp->dccps_iss;
Samuel Jerof541fb72012-02-26 18:22:02 -0700133 newdp->dccps_isr = dreq->dreq_isr;
134 newdp->dccps_gsr = dreq->dreq_gsr;
Gerrit Renkerbe4c7982008-06-11 11:19:10 +0100135
Arnaldo Carvalho de Melo03ace392005-08-21 05:36:45 -0300136 /*
Gerrit Renker0b53d462010-10-11 20:35:40 +0200137 * Activate features: initialise CCIDs, sequence windows etc.
Gerrit Renker192b27f2008-12-08 01:15:55 -0800138 */
139 if (dccp_feat_activate_values(newsk, &dreq->dreq_featneg)) {
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;
145 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700146 dccp_init_xmit_timers(newsk);
147
148 DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);
149 }
150 return newsk;
151}
152
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800153EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
154
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200155/*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700156 * Process an incoming packet for RESPOND sockets represented
157 * as an request_sock.
158 */
159struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
160 struct request_sock *req,
161 struct request_sock **prev)
162{
163 struct sock *child = NULL;
Gerrit Renker81096162007-12-13 12:31:26 -0200164 struct dccp_request_sock *dreq = dccp_rsk(req);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700165
166 /* Check for retransmitted REQUEST */
167 if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700168
Samuel Jerof541fb72012-02-26 18:22:02 -0700169 if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_gsr)) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700170 dccp_pr_debug("Retransmitted REQUEST\n");
Samuel Jerof541fb72012-02-26 18:22:02 -0700171 dreq->dreq_gsr = DCCP_SKB_CB(skb)->dccpd_seq;
Gerrit Renkere11d9d32006-11-13 13:12:07 -0200172 /*
173 * Send another RESPONSE packet
174 * To protect against Request floods, increment retrans
175 * counter (backoff, monitored by dccp_response_timer).
176 */
Eric Dumazete6c022a2012-10-27 23:16:46 +0000177 inet_rtx_syn_ack(sk, req);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700178 }
179 /* Network Duplicate, discard packet */
180 return NULL;
181 }
182
183 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
184
185 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK &&
186 dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK)
187 goto drop;
188
189 /* Invalid ACK */
Samuel Jerof541fb72012-02-26 18:22:02 -0700190 if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
191 dreq->dreq_iss, dreq->dreq_gss)) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300192 dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "
Samuel Jerof541fb72012-02-26 18:22:02 -0700193 "dreq_iss=%llu, dreq_gss=%llu\n",
David S. Millerf6ccf552005-08-09 20:27:14 -0700194 (unsigned long long)
195 DCCP_SKB_CB(skb)->dccpd_ack_seq,
Samuel Jerof541fb72012-02-26 18:22:02 -0700196 (unsigned long long) dreq->dreq_iss,
197 (unsigned long long) dreq->dreq_gss);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700198 goto drop;
199 }
200
Gerrit Renker81096162007-12-13 12:31:26 -0200201 if (dccp_parse_options(sk, dreq, skb))
202 goto drop;
203
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800204 child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700205 if (child == NULL)
206 goto listen_overflow;
207
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700208 inet_csk_reqsk_queue_unlink(sk, req, prev);
209 inet_csk_reqsk_queue_removed(sk, req);
210 inet_csk_reqsk_queue_add(sk, req, child);
211out:
212 return child;
213listen_overflow:
214 dccp_pr_debug("listen_overflow!\n");
215 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
216drop:
217 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800218 req->rsk_ops->send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700219
220 inet_csk_reqsk_queue_drop(sk, req, prev);
221 goto out;
222}
223
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800224EXPORT_SYMBOL_GPL(dccp_check_req);
225
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700226/*
227 * Queue segment on the new socket if the new socket is active,
228 * otherwise we just shortcircuit this and continue with
229 * the new socket.
230 */
231int dccp_child_process(struct sock *parent, struct sock *child,
232 struct sk_buff *skb)
233{
234 int ret = 0;
235 const int state = child->sk_state;
236
237 if (!sock_owned_by_user(child)) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300238 ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb),
239 skb->len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700240
241 /* Wakeup parent, send SIGIO */
242 if (state == DCCP_RESPOND && child->sk_state != state)
243 parent->sk_data_ready(parent, 0);
244 } else {
245 /* Alas, it is possible again, because we do lookup
246 * in main socket hash table and lock on listening
247 * socket does not protect us more.
248 */
Zhu Yia3a858f2010-03-04 18:01:47 +0000249 __sk_add_backlog(child, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700250 }
251
252 bh_unlock_sock(child);
253 sock_put(child);
254 return ret;
255}
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800256
257EXPORT_SYMBOL_GPL(dccp_child_process);
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200258
Gui Jianfeng6edafaa2008-08-06 23:50:04 -0700259void dccp_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
260 struct request_sock *rsk)
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200261{
Gerrit Renker59348b12006-11-20 18:39:23 -0200262 DCCP_BUG("DCCP-ACK packets are never sent in LISTEN/RESPOND state");
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200263}
264
265EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack);
Gerrit Renkercf557922006-11-10 16:08:37 -0200266
Gerrit Renkerac757732008-11-04 23:55:49 -0800267int dccp_reqsk_init(struct request_sock *req,
268 struct dccp_sock const *dp, struct sk_buff const *skb)
Gerrit Renkercf557922006-11-10 16:08:37 -0200269{
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200270 struct dccp_request_sock *dreq = dccp_rsk(req);
271
272 inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
Gerrit Renker944f7502008-10-19 23:36:47 -0700273 inet_rsk(req)->loc_port = dccp_hdr(skb)->dccph_dport;
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200274 inet_rsk(req)->acked = 0;
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200275 dreq->dreq_timestamp_echo = 0;
Gerrit Renkerac757732008-11-04 23:55:49 -0800276
277 /* inherit feature negotiation options from listening socket */
278 return dccp_feat_clone_list(&dp->dccps_featneg, &dreq->dreq_featneg);
Gerrit Renkercf557922006-11-10 16:08:37 -0200279}
280
281EXPORT_SYMBOL_GPL(dccp_reqsk_init);