Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / net / dccp / minisocks.c
blob37ccbe62eb1af3f9dffbf63323c008cc96cd8ea1
1 /*
2 * net/dccp/minisocks.c
4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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.
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>
19 #include <net/sock.h>
20 #include <net/xfrm.h>
21 #include <net/inet_timewait_sock.h>
23 #include "ackvec.h"
24 #include "ccid.h"
25 #include "dccp.h"
26 #include "feat.h"
28 struct inet_timewait_death_row dccp_death_row = {
29 .sysctl_max_tw_buckets = NR_FILE * 2,
30 .hashinfo = &dccp_hashinfo,
33 EXPORT_SYMBOL_GPL(dccp_death_row);
35 void dccp_time_wait(struct sock *sk, int state, int timeo)
37 struct inet_timewait_sock *tw;
39 tw = inet_twsk_alloc(sk, &dccp_death_row, state);
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;
50 #endif
52 /* Get the TIME_WAIT timeout firing. */
53 if (timeo < rto)
54 timeo = rto;
56 tw->tw_timeout = DCCP_TIMEWAIT_LEN;
57 if (state == DCCP_TIME_WAIT)
58 timeo = DCCP_TIMEWAIT_LEN;
60 /* tw_timer is pinned, so we need to make sure BH are disabled
61 * in following section, otherwise timer handler could run before
62 * we complete the initialization.
64 local_bh_disable();
65 inet_twsk_schedule(tw, timeo);
66 /* Linkage updates.
67 * Note that access to tw after this point is illegal.
69 inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
70 local_bh_enable();
71 } else {
72 /* Sorry, if we're out of memory, just CLOSE this
73 * socket up. We've got bigger problems than
74 * non-graceful socket closings.
76 DCCP_WARN("time wait bucket table overflow\n");
79 dccp_done(sk);
82 struct sock *dccp_create_openreq_child(const struct sock *sk,
83 const struct request_sock *req,
84 const struct sk_buff *skb)
87 * Step 3: Process LISTEN state
89 * (* Generate a new socket and switch to that socket *)
90 * Set S := new socket for this port pair
92 struct sock *newsk = inet_csk_clone_lock(sk, req, GFP_ATOMIC);
94 if (newsk != NULL) {
95 struct dccp_request_sock *dreq = dccp_rsk(req);
96 struct inet_connection_sock *newicsk = inet_csk(newsk);
97 struct dccp_sock *newdp = dccp_sk(newsk);
99 newdp->dccps_role = DCCP_ROLE_SERVER;
100 newdp->dccps_hc_rx_ackvec = NULL;
101 newdp->dccps_service_list = NULL;
102 newdp->dccps_service = dreq->dreq_service;
103 newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
104 newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
105 newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
107 INIT_LIST_HEAD(&newdp->dccps_featneg);
109 * Step 3: Process LISTEN state
111 * Choose S.ISS (initial seqno) or set from Init Cookies
112 * Initialize S.GAR := S.ISS
113 * Set S.ISR, S.GSR from packet (or Init Cookies)
115 * Setting AWL/AWH and SWL/SWH happens as part of the feature
116 * activation below, as these windows all depend on the local
117 * and remote Sequence Window feature values (7.5.2).
119 newdp->dccps_iss = dreq->dreq_iss;
120 newdp->dccps_gss = dreq->dreq_gss;
121 newdp->dccps_gar = newdp->dccps_iss;
122 newdp->dccps_isr = dreq->dreq_isr;
123 newdp->dccps_gsr = dreq->dreq_gsr;
126 * Activate features: initialise CCIDs, sequence windows etc.
128 if (dccp_feat_activate_values(newsk, &dreq->dreq_featneg)) {
129 sk_free_unlock_clone(newsk);
130 return NULL;
132 dccp_init_xmit_timers(newsk);
134 __DCCP_INC_STATS(DCCP_MIB_PASSIVEOPENS);
136 return newsk;
139 EXPORT_SYMBOL_GPL(dccp_create_openreq_child);
142 * Process an incoming packet for RESPOND sockets represented
143 * as an request_sock.
145 struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,
146 struct request_sock *req)
148 struct sock *child = NULL;
149 struct dccp_request_sock *dreq = dccp_rsk(req);
150 bool own_req;
152 /* TCP/DCCP listeners became lockless.
153 * DCCP stores complex state in its request_sock, so we need
154 * a protection for them, now this code runs without being protected
155 * by the parent (listener) lock.
157 spin_lock_bh(&dreq->dreq_lock);
159 /* Check for retransmitted REQUEST */
160 if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
162 if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_gsr)) {
163 dccp_pr_debug("Retransmitted REQUEST\n");
164 dreq->dreq_gsr = DCCP_SKB_CB(skb)->dccpd_seq;
166 * Send another RESPONSE packet
167 * To protect against Request floods, increment retrans
168 * counter (backoff, monitored by dccp_response_timer).
170 inet_rtx_syn_ack(sk, req);
172 /* Network Duplicate, discard packet */
173 goto out;
176 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
178 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK &&
179 dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK)
180 goto drop;
182 /* Invalid ACK */
183 if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
184 dreq->dreq_iss, dreq->dreq_gss)) {
185 dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "
186 "dreq_iss=%llu, dreq_gss=%llu\n",
187 (unsigned long long)
188 DCCP_SKB_CB(skb)->dccpd_ack_seq,
189 (unsigned long long) dreq->dreq_iss,
190 (unsigned long long) dreq->dreq_gss);
191 goto drop;
194 if (dccp_parse_options(sk, dreq, skb))
195 goto drop;
197 child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL,
198 req, &own_req);
199 if (child) {
200 child = inet_csk_complete_hashdance(sk, child, req, own_req);
201 goto out;
204 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
205 drop:
206 if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)
207 req->rsk_ops->send_reset(sk, skb);
209 inet_csk_reqsk_queue_drop(sk, req);
210 out:
211 spin_unlock_bh(&dreq->dreq_lock);
212 return child;
215 EXPORT_SYMBOL_GPL(dccp_check_req);
218 * Queue segment on the new socket if the new socket is active,
219 * otherwise we just shortcircuit this and continue with
220 * the new socket.
222 int dccp_child_process(struct sock *parent, struct sock *child,
223 struct sk_buff *skb)
225 int ret = 0;
226 const int state = child->sk_state;
228 if (!sock_owned_by_user(child)) {
229 ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb),
230 skb->len);
232 /* Wakeup parent, send SIGIO */
233 if (state == DCCP_RESPOND && child->sk_state != state)
234 parent->sk_data_ready(parent);
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.
240 __sk_add_backlog(child, skb);
243 bh_unlock_sock(child);
244 sock_put(child);
245 return ret;
248 EXPORT_SYMBOL_GPL(dccp_child_process);
250 void dccp_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
251 struct request_sock *rsk)
253 DCCP_BUG("DCCP-ACK packets are never sent in LISTEN/RESPOND state");
256 EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack);
258 int dccp_reqsk_init(struct request_sock *req,
259 struct dccp_sock const *dp, struct sk_buff const *skb)
261 struct dccp_request_sock *dreq = dccp_rsk(req);
263 spin_lock_init(&dreq->dreq_lock);
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;
269 /* inherit feature negotiation options from listening socket */
270 return dccp_feat_clone_list(&dp->dccps_featneg, &dreq->dreq_featneg);
273 EXPORT_SYMBOL_GPL(dccp_reqsk_init);