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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
7c657876 ACM |
2 | /* |
3 | * net/dccp/minisocks.c | |
4 | * | |
5 | * An implementation of the DCCP protocol | |
6 | * Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
7c657876 ACM |
7 | */ |
8 | ||
7c657876 | 9 | #include <linux/dccp.h> |
5a0e3ad6 | 10 | #include <linux/gfp.h> |
8a73cd09 | 11 | #include <linux/kernel.h> |
7c657876 ACM |
12 | #include <linux/skbuff.h> |
13 | #include <linux/timer.h> | |
14 | ||
15 | #include <net/sock.h> | |
16 | #include <net/xfrm.h> | |
17 | #include <net/inet_timewait_sock.h> | |
18 | ||
ae31c339 | 19 | #include "ackvec.h" |
7c657876 ACM |
20 | #include "ccid.h" |
21 | #include "dccp.h" | |
afe00251 | 22 | #include "feat.h" |
7c657876 | 23 | |
64cf1e5d ACM |
24 | struct inet_timewait_death_row dccp_death_row = { |
25 | .sysctl_max_tw_buckets = NR_FILE * 2, | |
64cf1e5d | 26 | .hashinfo = &dccp_hashinfo, |
64cf1e5d ACM |
27 | }; |
28 | ||
f21e68ca ACM |
29 | EXPORT_SYMBOL_GPL(dccp_death_row); |
30 | ||
7c657876 ACM |
31 | void dccp_time_wait(struct sock *sk, int state, int timeo) |
32 | { | |
789f558c | 33 | struct inet_timewait_sock *tw; |
7c657876 | 34 | |
789f558c | 35 | tw = inet_twsk_alloc(sk, &dccp_death_row, state); |
64cf1e5d ACM |
36 | |
37 | if (tw != NULL) { | |
38 | const struct inet_connection_sock *icsk = inet_csk(sk); | |
39 | const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1); | |
dfd56b8b | 40 | #if IS_ENABLED(CONFIG_IPV6) |
3df80d93 | 41 | if (tw->tw_family == PF_INET6) { |
efe4208f ED |
42 | tw->tw_v6_daddr = sk->sk_v6_daddr; |
43 | tw->tw_v6_rcv_saddr = sk->sk_v6_rcv_saddr; | |
9fe516ba | 44 | tw->tw_ipv6only = sk->sk_ipv6only; |
3df80d93 ACM |
45 | } |
46 | #endif | |
64cf1e5d ACM |
47 | |
48 | /* Get the TIME_WAIT timeout firing. */ | |
49 | if (timeo < rto) | |
50 | timeo = rto; | |
51 | ||
64cf1e5d ACM |
52 | if (state == DCCP_TIME_WAIT) |
53 | timeo = DCCP_TIMEWAIT_LEN; | |
54 | ||
cfac7f83 ED |
55 | /* tw_timer is pinned, so we need to make sure BH are disabled |
56 | * in following section, otherwise timer handler could run before | |
57 | * we complete the initialization. | |
58 | */ | |
59 | local_bh_disable(); | |
789f558c | 60 | inet_twsk_schedule(tw, timeo); |
ec94c269 ED |
61 | /* Linkage updates. |
62 | * Note that access to tw after this point is illegal. | |
63 | */ | |
64 | inet_twsk_hashdance(tw, sk, &dccp_hashinfo); | |
cfac7f83 | 65 | local_bh_enable(); |
64cf1e5d ACM |
66 | } else { |
67 | /* Sorry, if we're out of memory, just CLOSE this | |
68 | * socket up. We've got bigger problems than | |
69 | * non-graceful socket closings. | |
70 | */ | |
59348b19 | 71 | DCCP_WARN("time wait bucket table overflow\n"); |
64cf1e5d ACM |
72 | } |
73 | ||
74 | dccp_done(sk); | |
7c657876 ACM |
75 | } |
76 | ||
54105f98 | 77 | struct sock *dccp_create_openreq_child(const struct sock *sk, |
7c657876 ACM |
78 | const struct request_sock *req, |
79 | const struct sk_buff *skb) | |
80 | { | |
81 | /* | |
82 | * Step 3: Process LISTEN state | |
83 | * | |
d83ca5ac GR |
84 | * (* Generate a new socket and switch to that socket *) |
85 | * Set S := new socket for this port pair | |
7c657876 | 86 | */ |
e56c57d0 | 87 | struct sock *newsk = inet_csk_clone_lock(sk, req, GFP_ATOMIC); |
7c657876 ACM |
88 | |
89 | if (newsk != NULL) { | |
192b27ff | 90 | struct dccp_request_sock *dreq = dccp_rsk(req); |
99c72ce0 | 91 | struct inet_connection_sock *newicsk = inet_csk(newsk); |
7c657876 ACM |
92 | struct dccp_sock *newdp = dccp_sk(newsk); |
93 | ||
b4d4f7c7 GR |
94 | newdp->dccps_role = DCCP_ROLE_SERVER; |
95 | newdp->dccps_hc_rx_ackvec = NULL; | |
b637487e TLSC |
96 | newdp->dccps_hc_rx_ccid = NULL; |
97 | newdp->dccps_hc_tx_ccid = NULL; | |
b4d4f7c7 | 98 | newdp->dccps_service_list = NULL; |
d9ea761f LZ |
99 | newdp->dccps_hc_rx_ccid = NULL; |
100 | newdp->dccps_hc_tx_ccid = NULL; | |
b4d4f7c7 GR |
101 | newdp->dccps_service = dreq->dreq_service; |
102 | newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo; | |
103 | newdp->dccps_timestamp_time = dreq->dreq_timestamp_time; | |
104 | newicsk->icsk_rto = DCCP_TIMEOUT_INIT; | |
7c657876 | 105 | |
ac75773c | 106 | INIT_LIST_HEAD(&newdp->dccps_featneg); |
7c657876 ACM |
107 | /* |
108 | * Step 3: Process LISTEN state | |
109 | * | |
d83ca5ac GR |
110 | * Choose S.ISS (initial seqno) or set from Init Cookies |
111 | * Initialize S.GAR := S.ISS | |
0b53d460 GR |
112 | * Set S.ISR, S.GSR from packet (or Init Cookies) |
113 | * | |
114 | * Setting AWL/AWH and SWL/SWH happens as part of the feature | |
115 | * activation below, as these windows all depend on the local | |
116 | * and remote Sequence Window feature values (7.5.2). | |
03ace394 | 117 | */ |
f541fb7e SJ |
118 | newdp->dccps_iss = dreq->dreq_iss; |
119 | newdp->dccps_gss = dreq->dreq_gss; | |
0b53d460 | 120 | newdp->dccps_gar = newdp->dccps_iss; |
f541fb7e SJ |
121 | newdp->dccps_isr = dreq->dreq_isr; |
122 | newdp->dccps_gsr = dreq->dreq_gsr; | |
03ace394 | 123 | |
192b27ff | 124 | /* |
0b53d460 | 125 | * Activate features: initialise CCIDs, sequence windows etc. |
192b27ff GR |
126 | */ |
127 | if (dccp_feat_activate_values(newsk, &dreq->dreq_featneg)) { | |
94352d45 | 128 | sk_free_unlock_clone(newsk); |
192b27ff GR |
129 | return NULL; |
130 | } | |
7c657876 ACM |
131 | dccp_init_xmit_timers(newsk); |
132 | ||
aa62d76b | 133 | __DCCP_INC_STATS(DCCP_MIB_PASSIVEOPENS); |
7c657876 ACM |
134 | } |
135 | return newsk; | |
136 | } | |
137 | ||
f21e68ca ACM |
138 | EXPORT_SYMBOL_GPL(dccp_create_openreq_child); |
139 | ||
8109b02b | 140 | /* |
7c657876 ACM |
141 | * Process an incoming packet for RESPOND sockets represented |
142 | * as an request_sock. | |
143 | */ | |
144 | struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb, | |
52452c54 | 145 | struct request_sock *req) |
7c657876 ACM |
146 | { |
147 | struct sock *child = NULL; | |
8109616e | 148 | struct dccp_request_sock *dreq = dccp_rsk(req); |
5e0724d0 | 149 | bool own_req; |
7c657876 | 150 | |
62f8f4d9 ED |
151 | /* TCP/DCCP listeners became lockless. |
152 | * DCCP stores complex state in its request_sock, so we need | |
153 | * a protection for them, now this code runs without being protected | |
154 | * by the parent (listener) lock. | |
155 | */ | |
156 | spin_lock_bh(&dreq->dreq_lock); | |
157 | ||
7c657876 ACM |
158 | /* Check for retransmitted REQUEST */ |
159 | if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) { | |
7c657876 | 160 | |
f541fb7e | 161 | if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_gsr)) { |
7c657876 | 162 | dccp_pr_debug("Retransmitted REQUEST\n"); |
f541fb7e | 163 | dreq->dreq_gsr = DCCP_SKB_CB(skb)->dccpd_seq; |
e11d9d30 GR |
164 | /* |
165 | * Send another RESPONSE packet | |
166 | * To protect against Request floods, increment retrans | |
167 | * counter (backoff, monitored by dccp_response_timer). | |
168 | */ | |
e6c022a4 | 169 | inet_rtx_syn_ack(sk, req); |
7c657876 ACM |
170 | } |
171 | /* Network Duplicate, discard packet */ | |
62f8f4d9 | 172 | goto out; |
7c657876 ACM |
173 | } |
174 | ||
175 | DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR; | |
176 | ||
177 | if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK && | |
178 | dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK) | |
179 | goto drop; | |
180 | ||
181 | /* Invalid ACK */ | |
f541fb7e SJ |
182 | if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, |
183 | dreq->dreq_iss, dreq->dreq_gss)) { | |
7690af3f | 184 | dccp_pr_debug("Invalid ACK number: ack_seq=%llu, " |
f541fb7e | 185 | "dreq_iss=%llu, dreq_gss=%llu\n", |
f6ccf554 DM |
186 | (unsigned long long) |
187 | DCCP_SKB_CB(skb)->dccpd_ack_seq, | |
f541fb7e SJ |
188 | (unsigned long long) dreq->dreq_iss, |
189 | (unsigned long long) dreq->dreq_gss); | |
7c657876 ACM |
190 | goto drop; |
191 | } | |
192 | ||
8109616e GR |
193 | if (dccp_parse_options(sk, dreq, skb)) |
194 | goto drop; | |
195 | ||
5e0724d0 ED |
196 | child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL, |
197 | req, &own_req); | |
62f8f4d9 ED |
198 | if (child) { |
199 | child = inet_csk_complete_hashdance(sk, child, req, own_req); | |
200 | goto out; | |
201 | } | |
5e0724d0 | 202 | |
7c657876 ACM |
203 | DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY; |
204 | drop: | |
205 | if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET) | |
cfb6eeb4 | 206 | req->rsk_ops->send_reset(sk, skb); |
7c657876 | 207 | |
52452c54 | 208 | inet_csk_reqsk_queue_drop(sk, req); |
62f8f4d9 ED |
209 | out: |
210 | spin_unlock_bh(&dreq->dreq_lock); | |
211 | return child; | |
7c657876 ACM |
212 | } |
213 | ||
f21e68ca ACM |
214 | EXPORT_SYMBOL_GPL(dccp_check_req); |
215 | ||
7c657876 ACM |
216 | /* |
217 | * Queue segment on the new socket if the new socket is active, | |
218 | * otherwise we just shortcircuit this and continue with | |
219 | * the new socket. | |
220 | */ | |
221 | int dccp_child_process(struct sock *parent, struct sock *child, | |
222 | struct sk_buff *skb) | |
3283ff2e | 223 | __releases(child) |
7c657876 ACM |
224 | { |
225 | int ret = 0; | |
226 | const int state = child->sk_state; | |
227 | ||
228 | if (!sock_owned_by_user(child)) { | |
7690af3f ACM |
229 | ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb), |
230 | skb->len); | |
7c657876 ACM |
231 | |
232 | /* Wakeup parent, send SIGIO */ | |
233 | if (state == DCCP_RESPOND && child->sk_state != state) | |
676d2369 | 234 | parent->sk_data_ready(parent); |
7c657876 ACM |
235 | } else { |
236 | /* Alas, it is possible again, because we do lookup | |
237 | * in main socket hash table and lock on listening | |
238 | * socket does not protect us more. | |
239 | */ | |
a3a858ff | 240 | __sk_add_backlog(child, skb); |
7c657876 ACM |
241 | } |
242 | ||
243 | bh_unlock_sock(child); | |
244 | sock_put(child); | |
245 | return ret; | |
246 | } | |
f21e68ca ACM |
247 | |
248 | EXPORT_SYMBOL_GPL(dccp_child_process); | |
8a73cd09 | 249 | |
a00e7444 | 250 | void dccp_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, |
6edafaaf | 251 | struct request_sock *rsk) |
8a73cd09 | 252 | { |
59348b19 | 253 | DCCP_BUG("DCCP-ACK packets are never sent in LISTEN/RESPOND state"); |
8a73cd09 GR |
254 | } |
255 | ||
256 | EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack); | |
cf557926 | 257 | |
ac75773c GR |
258 | int dccp_reqsk_init(struct request_sock *req, |
259 | struct dccp_sock const *dp, struct sk_buff const *skb) | |
cf557926 | 260 | { |
b4d4f7c7 GR |
261 | struct dccp_request_sock *dreq = dccp_rsk(req); |
262 | ||
62f8f4d9 | 263 | spin_lock_init(&dreq->dreq_lock); |
b44084c2 ED |
264 | inet_rsk(req)->ir_rmt_port = dccp_hdr(skb)->dccph_sport; |
265 | inet_rsk(req)->ir_num = ntohs(dccp_hdr(skb)->dccph_dport); | |
266 | inet_rsk(req)->acked = 0; | |
267 | dreq->dreq_timestamp_echo = 0; | |
ac75773c GR |
268 | |
269 | /* inherit feature negotiation options from listening socket */ | |
270 | return dccp_feat_clone_list(&dp->dccps_featneg, &dreq->dreq_featneg); | |
cf557926 GR |
271 | } |
272 | ||
273 | EXPORT_SYMBOL_GPL(dccp_reqsk_init); |