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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,
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070030 .hashinfo = &dccp_hashinfo,
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070031};
32
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -080033EXPORT_SYMBOL_GPL(dccp_death_row);
34
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070035void dccp_time_wait(struct sock *sk, int state, int timeo)
36{
Eric Dumazet789f5582015-04-12 18:51:09 -070037 struct inet_timewait_sock *tw;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070038
Eric Dumazet789f5582015-04-12 18:51:09 -070039 tw = inet_twsk_alloc(sk, &dccp_death_row, state);
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070040
41 if (tw != NULL) {
42 const struct inet_connection_sock *icsk = inet_csk(sk);
43 const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
Eric Dumazetdfd56b82011-12-10 09:48:31 +000044#if IS_ENABLED(CONFIG_IPV6)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080045 if (tw->tw_family == PF_INET6) {
Eric Dumazetefe42082013-10-03 15:42:29 -070046 tw->tw_v6_daddr = sk->sk_v6_daddr;
47 tw->tw_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
Eric Dumazet9fe516b2014-06-27 08:36:16 -070048 tw->tw_ipv6only = sk->sk_ipv6only;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080049 }
50#endif
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070051 /* Linkage updates. */
52 __inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
53
54 /* Get the TIME_WAIT timeout firing. */
55 if (timeo < rto)
56 timeo = rto;
57
58 tw->tw_timeout = DCCP_TIMEWAIT_LEN;
59 if (state == DCCP_TIME_WAIT)
60 timeo = DCCP_TIMEWAIT_LEN;
61
Eric Dumazet789f5582015-04-12 18:51:09 -070062 inet_twsk_schedule(tw, timeo);
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070063 inet_twsk_put(tw);
64 } else {
65 /* Sorry, if we're out of memory, just CLOSE this
66 * socket up. We've got bigger problems than
67 * non-graceful socket closings.
68 */
Gerrit Renker59348b12006-11-20 18:39:23 -020069 DCCP_WARN("time wait bucket table overflow\n");
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -070070 }
71
72 dccp_done(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070073}
74
75struct sock *dccp_create_openreq_child(struct sock *sk,
76 const struct request_sock *req,
77 const struct sk_buff *skb)
78{
79 /*
80 * Step 3: Process LISTEN state
81 *
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -020082 * (* Generate a new socket and switch to that socket *)
83 * Set S := new socket for this port pair
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070084 */
Eric Dumazete56c57d2011-11-08 17:07:07 -050085 struct sock *newsk = inet_csk_clone_lock(sk, req, GFP_ATOMIC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070086
87 if (newsk != NULL) {
Gerrit Renker192b27f2008-12-08 01:15:55 -080088 struct dccp_request_sock *dreq = dccp_rsk(req);
Gerrit Renker99c72ce2007-03-06 14:24:44 -080089 struct inet_connection_sock *newicsk = inet_csk(newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070090 struct dccp_sock *newdp = dccp_sk(newsk);
91
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -020092 newdp->dccps_role = DCCP_ROLE_SERVER;
93 newdp->dccps_hc_rx_ackvec = NULL;
94 newdp->dccps_service_list = NULL;
95 newdp->dccps_service = dreq->dreq_service;
96 newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
97 newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
98 newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070099
Gerrit Renkerac757732008-11-04 23:55:49 -0800100 INIT_LIST_HEAD(&newdp->dccps_featneg);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700101 /*
102 * Step 3: Process LISTEN state
103 *
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200104 * Choose S.ISS (initial seqno) or set from Init Cookies
105 * Initialize S.GAR := S.ISS
Gerrit Renker0b53d462010-10-11 20:35:40 +0200106 * Set S.ISR, S.GSR from packet (or Init Cookies)
107 *
108 * Setting AWL/AWH and SWL/SWH happens as part of the feature
109 * activation below, as these windows all depend on the local
110 * and remote Sequence Window feature values (7.5.2).
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700111 */
Samuel Jerof541fb72012-02-26 18:22:02 -0700112 newdp->dccps_iss = dreq->dreq_iss;
113 newdp->dccps_gss = dreq->dreq_gss;
Gerrit Renker0b53d462010-10-11 20:35:40 +0200114 newdp->dccps_gar = newdp->dccps_iss;
Samuel Jerof541fb72012-02-26 18:22:02 -0700115 newdp->dccps_isr = dreq->dreq_isr;
116 newdp->dccps_gsr = dreq->dreq_gsr;
Gerrit Renkerbe4c7982008-06-11 11:19:10 +0100117
Arnaldo Carvalho de Melo03ace392005-08-21 05:36:45 -0300118 /*
Gerrit Renker0b53d462010-10-11 20:35:40 +0200119 * Activate features: initialise CCIDs, sequence windows etc.
Gerrit Renker192b27f2008-12-08 01:15:55 -0800120 */
121 if (dccp_feat_activate_values(newsk, &dreq->dreq_featneg)) {
122 /* It is still raw copy of parent, so invalidate
123 * destructor and make plain sk_free() */
124 newsk->sk_destruct = NULL;
125 sk_free(newsk);
126 return NULL;
127 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700128 dccp_init_xmit_timers(newsk);
129
130 DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);
131 }
132 return newsk;
133}
134
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800135EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
136
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200137/*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700138 * Process an incoming packet for RESPOND sockets represented
139 * as an request_sock.
140 */
141struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
Eric Dumazet52452c52015-03-19 19:04:19 -0700142 struct request_sock *req)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700143{
144 struct sock *child = NULL;
Gerrit Renker81096162007-12-13 12:31:26 -0200145 struct dccp_request_sock *dreq = dccp_rsk(req);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700146
147 /* Check for retransmitted REQUEST */
148 if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700149
Samuel Jerof541fb72012-02-26 18:22:02 -0700150 if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_gsr)) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700151 dccp_pr_debug("Retransmitted REQUEST\n");
Samuel Jerof541fb72012-02-26 18:22:02 -0700152 dreq->dreq_gsr = DCCP_SKB_CB(skb)->dccpd_seq;
Gerrit Renkere11d9d32006-11-13 13:12:07 -0200153 /*
154 * Send another RESPONSE packet
155 * To protect against Request floods, increment retrans
156 * counter (backoff, monitored by dccp_response_timer).
157 */
Eric Dumazete6c022a2012-10-27 23:16:46 +0000158 inet_rtx_syn_ack(sk, req);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700159 }
160 /* Network Duplicate, discard packet */
161 return NULL;
162 }
163
164 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
165
166 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK &&
167 dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK)
168 goto drop;
169
170 /* Invalid ACK */
Samuel Jerof541fb72012-02-26 18:22:02 -0700171 if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
172 dreq->dreq_iss, dreq->dreq_gss)) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300173 dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "
Samuel Jerof541fb72012-02-26 18:22:02 -0700174 "dreq_iss=%llu, dreq_gss=%llu\n",
David S. Millerf6ccf552005-08-09 20:27:14 -0700175 (unsigned long long)
176 DCCP_SKB_CB(skb)->dccpd_ack_seq,
Samuel Jerof541fb72012-02-26 18:22:02 -0700177 (unsigned long long) dreq->dreq_iss,
178 (unsigned long long) dreq->dreq_gss);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700179 goto drop;
180 }
181
Gerrit Renker81096162007-12-13 12:31:26 -0200182 if (dccp_parse_options(sk, dreq, skb))
183 goto drop;
184
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800185 child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700186 if (child == NULL)
187 goto listen_overflow;
188
Eric Dumazet52452c52015-03-19 19:04:19 -0700189 inet_csk_reqsk_queue_unlink(sk, req);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700190 inet_csk_reqsk_queue_removed(sk, req);
191 inet_csk_reqsk_queue_add(sk, req, child);
192out:
193 return child;
194listen_overflow:
195 dccp_pr_debug("listen_overflow!\n");
196 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
197drop:
198 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800199 req->rsk_ops->send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700200
Eric Dumazet52452c52015-03-19 19:04:19 -0700201 inet_csk_reqsk_queue_drop(sk, req);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700202 goto out;
203}
204
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800205EXPORT_SYMBOL_GPL(dccp_check_req);
206
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700207/*
208 * Queue segment on the new socket if the new socket is active,
209 * otherwise we just shortcircuit this and continue with
210 * the new socket.
211 */
212int dccp_child_process(struct sock *parent, struct sock *child,
213 struct sk_buff *skb)
214{
215 int ret = 0;
216 const int state = child->sk_state;
217
218 if (!sock_owned_by_user(child)) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300219 ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb),
220 skb->len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700221
222 /* Wakeup parent, send SIGIO */
223 if (state == DCCP_RESPOND && child->sk_state != state)
David S. Miller676d2362014-04-11 16:15:36 -0400224 parent->sk_data_ready(parent);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700225 } else {
226 /* Alas, it is possible again, because we do lookup
227 * in main socket hash table and lock on listening
228 * socket does not protect us more.
229 */
Zhu Yia3a858f2010-03-04 18:01:47 +0000230 __sk_add_backlog(child, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700231 }
232
233 bh_unlock_sock(child);
234 sock_put(child);
235 return ret;
236}
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800237
238EXPORT_SYMBOL_GPL(dccp_child_process);
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200239
Gui Jianfeng6edafaa2008-08-06 23:50:04 -0700240void dccp_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
241 struct request_sock *rsk)
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200242{
Gerrit Renker59348b12006-11-20 18:39:23 -0200243 DCCP_BUG("DCCP-ACK packets are never sent in LISTEN/RESPOND state");
Gerrit Renker8a73cd02006-11-10 12:32:01 -0200244}
245
246EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack);
Gerrit Renkercf557922006-11-10 16:08:37 -0200247
Gerrit Renkerac757732008-11-04 23:55:49 -0800248int dccp_reqsk_init(struct request_sock *req,
249 struct dccp_sock const *dp, struct sk_buff const *skb)
Gerrit Renkercf557922006-11-10 16:08:37 -0200250{
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200251 struct dccp_request_sock *dreq = dccp_rsk(req);
252
Eric Dumazetb44084c2013-10-10 00:04:37 -0700253 inet_rsk(req)->ir_rmt_port = dccp_hdr(skb)->dccph_sport;
254 inet_rsk(req)->ir_num = ntohs(dccp_hdr(skb)->dccph_dport);
255 inet_rsk(req)->acked = 0;
256 dreq->dreq_timestamp_echo = 0;
Gerrit Renkerac757732008-11-04 23:55:49 -0800257
258 /* inherit feature negotiation options from listening socket */
259 return dccp_feat_clone_list(&dp->dccps_featneg, &dreq->dreq_featneg);
Gerrit Renkercf557922006-11-10 16:08:37 -0200260}
261
262EXPORT_SYMBOL_GPL(dccp_reqsk_init);