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13#include <linux/dccp.h>
14#include <linux/gfp.h>
15#include <linux/kernel.h>
16#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
23#include "ackvec.h"
24#include "ccid.h"
25#include "dccp.h"
26#include "feat.h"
27
28struct inet_timewait_death_row dccp_death_row = {
29 .sysctl_max_tw_buckets = NR_FILE * 2,
30 .hashinfo = &dccp_hashinfo,
31};
32
33EXPORT_SYMBOL_GPL(dccp_death_row);
34
35void dccp_time_wait(struct sock *sk, int state, int timeo)
36{
37 struct inet_timewait_sock *tw;
38
39 tw = inet_twsk_alloc(sk, &dccp_death_row, state);
40
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);
44#if IS_ENABLED(CONFIG_IPV6)
45 if (tw->tw_family == PF_INET6) {
46 tw->tw_v6_daddr = sk->sk_v6_daddr;
47 tw->tw_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
48 tw->tw_ipv6only = sk->sk_ipv6only;
49 }
50#endif
51
52
53 if (timeo < rto)
54 timeo = rto;
55
56 tw->tw_timeout = DCCP_TIMEWAIT_LEN;
57 if (state == DCCP_TIME_WAIT)
58 timeo = DCCP_TIMEWAIT_LEN;
59
60 inet_twsk_schedule(tw, timeo);
61
62 __inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
63 inet_twsk_put(tw);
64 } else {
65
66
67
68
69 DCCP_WARN("time wait bucket table overflow\n");
70 }
71
72 dccp_done(sk);
73}
74
75struct sock *dccp_create_openreq_child(const struct sock *sk,
76 const struct request_sock *req,
77 const struct sk_buff *skb)
78{
79
80
81
82
83
84
85 struct sock *newsk = inet_csk_clone_lock(sk, req, GFP_ATOMIC);
86
87 if (newsk != NULL) {
88 struct dccp_request_sock *dreq = dccp_rsk(req);
89 struct inet_connection_sock *newicsk = inet_csk(newsk);
90 struct dccp_sock *newdp = dccp_sk(newsk);
91
92 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;
99
100 INIT_LIST_HEAD(&newdp->dccps_featneg);
101
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110
111
112 newdp->dccps_iss = dreq->dreq_iss;
113 newdp->dccps_gss = dreq->dreq_gss;
114 newdp->dccps_gar = newdp->dccps_iss;
115 newdp->dccps_isr = dreq->dreq_isr;
116 newdp->dccps_gsr = dreq->dreq_gsr;
117
118
119
120
121 if (dccp_feat_activate_values(newsk, &dreq->dreq_featneg)) {
122
123
124 newsk->sk_destruct = NULL;
125 sk_free(newsk);
126 return NULL;
127 }
128 dccp_init_xmit_timers(newsk);
129
130 DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);
131 }
132 return newsk;
133}
134
135EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
136
137
138
139
140
141struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
142 struct request_sock *req)
143{
144 struct sock *child = NULL;
145 struct dccp_request_sock *dreq = dccp_rsk(req);
146 bool own_req;
147
148
149 if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
150
151 if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_gsr)) {
152 dccp_pr_debug("Retransmitted REQUEST\n");
153 dreq->dreq_gsr = DCCP_SKB_CB(skb)->dccpd_seq;
154
155
156
157
158
159 inet_rtx_syn_ack(sk, req);
160 }
161
162 return NULL;
163 }
164
165 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
166
167 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK &&
168 dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK)
169 goto drop;
170
171
172 if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
173 dreq->dreq_iss, dreq->dreq_gss)) {
174 dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "
175 "dreq_iss=%llu, dreq_gss=%llu\n",
176 (unsigned long long)
177 DCCP_SKB_CB(skb)->dccpd_ack_seq,
178 (unsigned long long) dreq->dreq_iss,
179 (unsigned long long) dreq->dreq_gss);
180 goto drop;
181 }
182
183 if (dccp_parse_options(sk, dreq, skb))
184 goto drop;
185
186 child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL,
187 req, &own_req);
188 if (!child)
189 goto listen_overflow;
190
191 return inet_csk_complete_hashdance(sk, child, req, own_req);
192
193listen_overflow:
194 dccp_pr_debug("listen_overflow!\n");
195 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
196drop:
197 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)
198 req->rsk_ops->send_reset(sk, skb);
199
200 inet_csk_reqsk_queue_drop(sk, req);
201 return NULL;
202}
203
204EXPORT_SYMBOL_GPL(dccp_check_req);
205
206
207
208
209
210
211int dccp_child_process(struct sock *parent, struct sock *child,
212 struct sk_buff *skb)
213{
214 int ret = 0;
215 const int state = child->sk_state;
216
217 if (!sock_owned_by_user(child)) {
218 ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb),
219 skb->len);
220
221
222 if (state == DCCP_RESPOND && child->sk_state != state)
223 parent->sk_data_ready(parent);
224 } else {
225
226
227
228
229 __sk_add_backlog(child, skb);
230 }
231
232 bh_unlock_sock(child);
233 sock_put(child);
234 return ret;
235}
236
237EXPORT_SYMBOL_GPL(dccp_child_process);
238
239void dccp_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
240 struct request_sock *rsk)
241{
242 DCCP_BUG("DCCP-ACK packets are never sent in LISTEN/RESPOND state");
243}
244
245EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack);
246
247int dccp_reqsk_init(struct request_sock *req,
248 struct dccp_sock const *dp, struct sk_buff const *skb)
249{
250 struct dccp_request_sock *dreq = dccp_rsk(req);
251
252 inet_rsk(req)->ir_rmt_port = dccp_hdr(skb)->dccph_sport;
253 inet_rsk(req)->ir_num = ntohs(dccp_hdr(skb)->dccph_dport);
254 inet_rsk(req)->acked = 0;
255 dreq->dreq_timestamp_echo = 0;
256
257
258 return dccp_feat_clone_list(&dp->dccps_featneg, &dreq->dreq_featneg);
259}
260
261EXPORT_SYMBOL_GPL(dccp_reqsk_init);
262