blob: 31737cdf156a5e657760278c557cbb861d2961f7 [file] [log] [blame]
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001/*
2 * DCCP over IPv6
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -08003 * Linux INET6 implementation
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08004 *
5 * Based on net/dccp6/ipv6.c
6 *
7 * Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
14
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080015#include <linux/module.h>
16#include <linux/random.h>
17#include <linux/xfrm.h>
18
19#include <net/addrconf.h>
20#include <net/inet_common.h>
21#include <net/inet_hashtables.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020022#include <net/inet_sock.h>
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080023#include <net/inet6_connection_sock.h>
24#include <net/inet6_hashtables.h>
25#include <net/ip6_route.h>
26#include <net/ipv6.h>
27#include <net/protocol.h>
28#include <net/transp_v6.h>
David S. Milleraa0e4e42006-01-06 22:55:39 -080029#include <net/ip6_checksum.h>
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080030#include <net/xfrm.h>
31
32#include "dccp.h"
33#include "ipv6.h"
Ian McDonald4b79f0a2006-07-23 23:33:28 -070034#include "feat.h"
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080035
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080036/* Socket used for sending RSTs and ACKs */
37static struct socket *dccp_v6_ctl_socket;
38
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080039static struct inet_connection_sock_af_ops dccp_ipv6_mapped;
40static struct inet_connection_sock_af_ops dccp_ipv6_af_ops;
41
42static int dccp_v6_get_port(struct sock *sk, unsigned short snum)
43{
44 return inet_csk_get_port(&dccp_hashinfo, sk, snum,
45 inet6_csk_bind_conflict);
46}
47
48static void dccp_v6_hash(struct sock *sk)
49{
50 if (sk->sk_state != DCCP_CLOSED) {
51 if (inet_csk(sk)->icsk_af_ops == &dccp_ipv6_mapped) {
Arnaldo Carvalho de Meloc985ed72006-03-20 21:23:39 -080052 dccp_hash(sk);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080053 return;
54 }
55 local_bh_disable();
56 __inet6_hash(&dccp_hashinfo, sk);
57 local_bh_enable();
58 }
59}
60
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -020061/* add pseudo-header to DCCP checksum stored in skb->csum */
Al Viro868c86b2006-11-14 21:35:48 -080062static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb,
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -020063 struct in6_addr *saddr,
64 struct in6_addr *daddr)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080065{
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -020066 return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum);
67}
68
69static inline void dccp_v6_send_check(struct sock *sk, int unused_value,
70 struct sk_buff *skb)
71{
72 struct ipv6_pinfo *np = inet6_sk(sk);
73 struct dccp_hdr *dh = dccp_hdr(skb);
74
75 dccp_csum_outgoing(skb);
76 dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &np->daddr);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080077}
78
Al Viro7d533f92006-11-14 21:51:36 -080079static inline __u32 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr,
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -020080 __be16 sport, __be16 dport )
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080081{
Gerrit Renkerd7f73652006-11-13 13:34:38 -020082 return secure_tcpv6_sequence_number(saddr, daddr, sport, dport);
83}
84
85static inline __u32 dccp_v6_init_sequence(struct sk_buff *skb)
86{
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -070087 return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
88 ipv6_hdr(skb)->saddr.s6_addr32,
Gerrit Renkerd7f73652006-11-13 13:34:38 -020089 dccp_hdr(skb)->dccph_dport,
90 dccp_hdr(skb)->dccph_sport );
91
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080092}
93
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080094static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
Andrea Bittau60fe62e2006-03-20 19:23:32 -080095 int type, int code, int offset, __be32 info)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -080096{
97 struct ipv6hdr *hdr = (struct ipv6hdr *)skb->data;
98 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset);
99 struct ipv6_pinfo *np;
100 struct sock *sk;
101 int err;
102 __u64 seq;
103
104 sk = inet6_lookup(&dccp_hashinfo, &hdr->daddr, dh->dccph_dport,
YOSHIFUJI Hideakif2776ff2006-11-21 17:41:56 -0800105 &hdr->saddr, dh->dccph_sport, inet6_iif(skb));
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800106
107 if (sk == NULL) {
108 ICMP6_INC_STATS_BH(__in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
109 return;
110 }
111
112 if (sk->sk_state == DCCP_TIME_WAIT) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700113 inet_twsk_put(inet_twsk(sk));
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800114 return;
115 }
116
117 bh_lock_sock(sk);
118 if (sock_owned_by_user(sk))
119 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
120
121 if (sk->sk_state == DCCP_CLOSED)
122 goto out;
123
124 np = inet6_sk(sk);
125
126 if (type == ICMPV6_PKT_TOOBIG) {
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800127 struct dst_entry *dst = NULL;
128
129 if (sock_owned_by_user(sk))
130 goto out;
131 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
132 goto out;
133
134 /* icmp should have updated the destination cache entry */
135 dst = __sk_dst_check(sk, np->dst_cookie);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800136 if (dst == NULL) {
137 struct inet_sock *inet = inet_sk(sk);
138 struct flowi fl;
139
140 /* BUGGG_FUTURE: Again, it is not clear how
141 to handle rthdr case. Ignore this complexity
142 for now.
143 */
144 memset(&fl, 0, sizeof(fl));
145 fl.proto = IPPROTO_DCCP;
146 ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
147 ipv6_addr_copy(&fl.fl6_src, &np->saddr);
148 fl.oif = sk->sk_bound_dev_if;
149 fl.fl_ip_dport = inet->dport;
150 fl.fl_ip_sport = inet->sport;
Venkat Yekkiralabeb8d132006-08-04 23:12:42 -0700151 security_sk_classify_flow(sk, &fl);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800152
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800153 err = ip6_dst_lookup(sk, &dst, &fl);
154 if (err) {
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800155 sk->sk_err_soft = -err;
156 goto out;
157 }
158
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800159 err = xfrm_lookup(&dst, &fl, sk, 0);
160 if (err < 0) {
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800161 sk->sk_err_soft = -err;
162 goto out;
163 }
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800164 } else
165 dst_hold(dst);
166
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800167 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800168 dccp_sync_mss(sk, dst_mtu(dst));
169 } /* else let the usual retransmit timer handle it */
170 dst_release(dst);
171 goto out;
172 }
173
174 icmpv6_err_convert(type, code, &err);
175
176 seq = DCCP_SKB_CB(skb)->dccpd_seq;
177 /* Might be for an request_sock */
178 switch (sk->sk_state) {
179 struct request_sock *req, **prev;
180 case DCCP_LISTEN:
181 if (sock_owned_by_user(sk))
182 goto out;
183
184 req = inet6_csk_search_req(sk, &prev, dh->dccph_dport,
185 &hdr->daddr, &hdr->saddr,
186 inet6_iif(skb));
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800187 if (req == NULL)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800188 goto out;
189
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800190 /*
191 * ICMPs are not backlogged, hence we cannot get an established
192 * socket here.
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800193 */
194 BUG_TRAP(req->sk == NULL);
195
196 if (seq != dccp_rsk(req)->dreq_iss) {
197 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
198 goto out;
199 }
200
201 inet_csk_reqsk_queue_drop(sk, req, prev);
202 goto out;
203
204 case DCCP_REQUESTING:
205 case DCCP_RESPOND: /* Cannot happen.
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800206 It can, it SYNs are crossed. --ANK */
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800207 if (!sock_owned_by_user(sk)) {
208 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
209 sk->sk_err = err;
210 /*
211 * Wake people up to see the error
212 * (see connect in sock.c)
213 */
214 sk->sk_error_report(sk);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800215 dccp_done(sk);
216 } else
217 sk->sk_err_soft = err;
218 goto out;
219 }
220
221 if (!sock_owned_by_user(sk) && np->recverr) {
222 sk->sk_err = err;
223 sk->sk_error_report(sk);
224 } else
225 sk->sk_err_soft = err;
226
227out:
228 bh_unlock_sock(sk);
229 sock_put(sk);
230}
231
232
233static int dccp_v6_send_response(struct sock *sk, struct request_sock *req,
234 struct dst_entry *dst)
235{
236 struct inet6_request_sock *ireq6 = inet6_rsk(req);
237 struct ipv6_pinfo *np = inet6_sk(sk);
238 struct sk_buff *skb;
239 struct ipv6_txoptions *opt = NULL;
240 struct in6_addr *final_p = NULL, final;
241 struct flowi fl;
242 int err = -1;
243
244 memset(&fl, 0, sizeof(fl));
245 fl.proto = IPPROTO_DCCP;
246 ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
247 ipv6_addr_copy(&fl.fl6_src, &ireq6->loc_addr);
248 fl.fl6_flowlabel = 0;
249 fl.oif = ireq6->iif;
250 fl.fl_ip_dport = inet_rsk(req)->rmt_port;
251 fl.fl_ip_sport = inet_sk(sk)->sport;
Venkat Yekkirala4237c752006-07-24 23:32:50 -0700252 security_req_classify_flow(req, &fl);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800253
254 if (dst == NULL) {
255 opt = np->opt;
256 if (opt == NULL &&
257 np->rxopt.bits.osrcrt == 2 &&
258 ireq6->pktopts) {
259 struct sk_buff *pktopts = ireq6->pktopts;
260 struct inet6_skb_parm *rxopt = IP6CB(pktopts);
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800261
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800262 if (rxopt->srcrt)
263 opt = ipv6_invert_rthdr(sk,
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700264 (struct ipv6_rt_hdr *)(skb_network_header(pktopts) +
265 rxopt->srcrt));
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800266 }
267
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800268 if (opt != NULL && opt->srcrt != NULL) {
269 const struct rt0_hdr *rt0 = (struct rt0_hdr *)opt->srcrt;
270
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800271 ipv6_addr_copy(&final, &fl.fl6_dst);
272 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
273 final_p = &final;
274 }
275
276 err = ip6_dst_lookup(sk, &dst, &fl);
277 if (err)
278 goto done;
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800279
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800280 if (final_p)
281 ipv6_addr_copy(&fl.fl6_dst, final_p);
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800282
283 err = xfrm_lookup(&dst, &fl, sk, 0);
284 if (err < 0)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800285 goto done;
286 }
287
288 skb = dccp_make_response(sk, dst, req);
289 if (skb != NULL) {
290 struct dccp_hdr *dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800291
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200292 dh->dccph_checksum = dccp_v6_csum_finish(skb,
293 &ireq6->loc_addr,
294 &ireq6->rmt_addr);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800295 ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
296 err = ip6_xmit(sk, skb, &fl, opt, 0);
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200297 err = net_xmit_eval(err);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800298 }
299
300done:
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800301 if (opt != NULL && opt != np->opt)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800302 sock_kfree_s(sk, opt, opt->tot_len);
David S. Miller0cbd7822006-01-31 17:53:37 -0800303 dst_release(dst);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800304 return err;
305}
306
307static void dccp_v6_reqsk_destructor(struct request_sock *req)
308{
309 if (inet6_rsk(req)->pktopts != NULL)
310 kfree_skb(inet6_rsk(req)->pktopts);
311}
312
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800313static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800314{
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800315 struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700316 struct ipv6hdr *rxip6h;
Arnaldo Carvalho de Melo118b2c92006-03-20 22:31:09 -0800317 const u32 dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800318 sizeof(struct dccp_hdr_ext) +
319 sizeof(struct dccp_hdr_reset);
320 struct sk_buff *skb;
321 struct flowi fl;
Gerrit Renker09dbc382006-11-14 12:57:34 -0200322 u64 seqno = 0;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800323
324 if (rxdh->dccph_type == DCCP_PKT_RESET)
325 return;
326
327 if (!ipv6_unicast_destination(rxskb))
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800328 return;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800329
Arnaldo Carvalho de Melo118b2c92006-03-20 22:31:09 -0800330 skb = alloc_skb(dccp_v6_ctl_socket->sk->sk_prot->max_header,
331 GFP_ATOMIC);
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800332 if (skb == NULL)
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200333 return;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800334
Arnaldo Carvalho de Melo118b2c92006-03-20 22:31:09 -0800335 skb_reserve(skb, dccp_v6_ctl_socket->sk->sk_prot->max_header);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800336
Gerrit Renker9b420782006-11-10 11:22:32 -0200337 dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800338
339 /* Swap the send and the receive. */
340 dh->dccph_type = DCCP_PKT_RESET;
341 dh->dccph_sport = rxdh->dccph_dport;
342 dh->dccph_dport = rxdh->dccph_sport;
343 dh->dccph_doff = dccp_hdr_reset_len / 4;
344 dh->dccph_x = 1;
345 dccp_hdr_reset(skb)->dccph_reset_code =
346 DCCP_SKB_CB(rxskb)->dccpd_reset_code;
347
Gerrit Renker0e64e942006-10-24 16:17:51 -0700348 /* See "8.3.1. Abnormal Termination" in RFC 4340 */
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800349 if (DCCP_SKB_CB(rxskb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
350 dccp_set_seqno(&seqno, DCCP_SKB_CB(rxskb)->dccpd_ack_seq + 1);
351
352 dccp_hdr_set_seq(dh, seqno);
Gerrit Renker09dbc382006-11-14 12:57:34 -0200353 dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), DCCP_SKB_CB(rxskb)->dccpd_seq);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800354
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200355 dccp_csum_outgoing(skb);
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700356 rxip6h = ipv6_hdr(rxskb);
357 dh->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
358 &rxip6h->daddr);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200359
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800360 memset(&fl, 0, sizeof(fl));
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700361 ipv6_addr_copy(&fl.fl6_dst, &rxip6h->saddr);
362 ipv6_addr_copy(&fl.fl6_src, &rxip6h->daddr);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200363
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800364 fl.proto = IPPROTO_DCCP;
365 fl.oif = inet6_iif(rxskb);
366 fl.fl_ip_dport = dh->dccph_dport;
367 fl.fl_ip_sport = dh->dccph_sport;
Venkat Yekkiralabeb8d132006-08-04 23:12:42 -0700368 security_skb_classify_flow(rxskb, &fl);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800369
370 /* sk = NULL, but it is safe for now. RST socket required. */
371 if (!ip6_dst_lookup(NULL, &skb->dst, &fl)) {
372 if (xfrm_lookup(&skb->dst, &fl, NULL, 0) >= 0) {
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800373 ip6_xmit(dccp_v6_ctl_socket->sk, skb, &fl, NULL, 0);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800374 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
375 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
376 return;
377 }
378 }
379
380 kfree_skb(skb);
381}
382
Gerrit Renker73c9e022006-11-10 13:01:31 -0200383static struct request_sock_ops dccp6_request_sock_ops = {
384 .family = AF_INET6,
385 .obj_size = sizeof(struct dccp6_request_sock),
386 .rtx_syn_ack = dccp_v6_send_response,
387 .send_ack = dccp_reqsk_send_ack,
388 .destructor = dccp_v6_reqsk_destructor,
389 .send_reset = dccp_v6_ctl_send_reset,
390};
391
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800392static struct sock *dccp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
393{
394 const struct dccp_hdr *dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700395 const struct ipv6hdr *iph = ipv6_hdr(skb);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800396 struct sock *nsk;
397 struct request_sock **prev;
398 /* Find possible connection requests. */
399 struct request_sock *req = inet6_csk_search_req(sk, &prev,
400 dh->dccph_sport,
401 &iph->saddr,
402 &iph->daddr,
403 inet6_iif(skb));
404 if (req != NULL)
405 return dccp_check_req(sk, skb, req, prev);
406
407 nsk = __inet6_lookup_established(&dccp_hashinfo,
408 &iph->saddr, dh->dccph_sport,
409 &iph->daddr, ntohs(dh->dccph_dport),
410 inet6_iif(skb));
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800411 if (nsk != NULL) {
412 if (nsk->sk_state != DCCP_TIME_WAIT) {
413 bh_lock_sock(nsk);
414 return nsk;
415 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700416 inet_twsk_put(inet_twsk(nsk));
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800417 return NULL;
418 }
419
420 return sk;
421}
422
423static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
424{
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800425 struct request_sock *req;
426 struct dccp_request_sock *dreq;
427 struct inet6_request_sock *ireq6;
428 struct ipv6_pinfo *np = inet6_sk(sk);
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200429 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800430 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
431 __u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
432
433 if (skb->protocol == htons(ETH_P_IP))
434 return dccp_v4_conn_request(sk, skb);
435
436 if (!ipv6_unicast_destination(skb))
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800437 goto drop;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800438
439 if (dccp_bad_service_code(sk, service)) {
440 reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
441 goto drop;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200442 }
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800443 /*
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800444 * There are no SYN attacks on IPv6, yet...
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800445 */
446 if (inet_csk_reqsk_queue_is_full(sk))
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800447 goto drop;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800448
449 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
450 goto drop;
451
Gerrit Renker82709532006-10-11 16:26:54 +0100452 req = inet6_reqsk_alloc(&dccp6_request_sock_ops);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800453 if (req == NULL)
454 goto drop;
455
Gerrit Renkercf557922006-11-10 16:08:37 -0200456 if (dccp_parse_options(sk, skb))
457 goto drop_and_free;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800458
Gerrit Renkercf557922006-11-10 16:08:37 -0200459 dccp_reqsk_init(req, skb);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800460
Venkat Yekkirala4237c752006-07-24 23:32:50 -0700461 if (security_inet_conn_request(sk, skb, req))
462 goto drop_and_free;
463
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800464 ireq6 = inet6_rsk(req);
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700465 ipv6_addr_copy(&ireq6->rmt_addr, &ipv6_hdr(skb)->saddr);
466 ipv6_addr_copy(&ireq6->loc_addr, &ipv6_hdr(skb)->daddr);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800467 ireq6->pktopts = NULL;
468
469 if (ipv6_opt_accepted(sk, skb) ||
470 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
471 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
472 atomic_inc(&skb->users);
473 ireq6->pktopts = skb;
474 }
475 ireq6->iif = sk->sk_bound_dev_if;
476
477 /* So that link locals have meaning */
478 if (!sk->sk_bound_dev_if &&
479 ipv6_addr_type(&ireq6->rmt_addr) & IPV6_ADDR_LINKLOCAL)
480 ireq6->iif = inet6_iif(skb);
481
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800482 /*
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800483 * Step 3: Process LISTEN state
484 *
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200485 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800486 *
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200487 * In fact we defer setting S.GSR, S.SWL, S.SWH to
488 * dccp_create_openreq_child.
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800489 */
490 dreq = dccp_rsk(req);
491 dreq->dreq_isr = dcb->dccpd_seq;
Gerrit Renker865e9022006-11-13 13:31:50 -0200492 dreq->dreq_iss = dccp_v6_init_sequence(skb);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800493 dreq->dreq_service = service;
494
495 if (dccp_v6_send_response(sk, req, NULL))
496 goto drop_and_free;
497
498 inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
499 return 0;
500
501drop_and_free:
502 reqsk_free(req);
503drop:
504 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
505 dcb->dccpd_reset_code = reset_code;
506 return -1;
507}
508
509static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
510 struct sk_buff *skb,
511 struct request_sock *req,
512 struct dst_entry *dst)
513{
514 struct inet6_request_sock *ireq6 = inet6_rsk(req);
515 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
516 struct inet_sock *newinet;
517 struct dccp_sock *newdp;
518 struct dccp6_sock *newdp6;
519 struct sock *newsk;
520 struct ipv6_txoptions *opt;
521
522 if (skb->protocol == htons(ETH_P_IP)) {
523 /*
524 * v6 mapped
525 */
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800526 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst);
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800527 if (newsk == NULL)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800528 return NULL;
529
530 newdp6 = (struct dccp6_sock *)newsk;
531 newdp = dccp_sk(newsk);
532 newinet = inet_sk(newsk);
533 newinet->pinet6 = &newdp6->inet6;
534 newnp = inet6_sk(newsk);
535
536 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
537
538 ipv6_addr_set(&newnp->daddr, 0, 0, htonl(0x0000FFFF),
539 newinet->daddr);
540
541 ipv6_addr_set(&newnp->saddr, 0, 0, htonl(0x0000FFFF),
542 newinet->saddr);
543
544 ipv6_addr_copy(&newnp->rcv_saddr, &newnp->saddr);
545
546 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
547 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
548 newnp->pktoptions = NULL;
549 newnp->opt = NULL;
550 newnp->mcast_oif = inet6_iif(skb);
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700551 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800552
553 /*
554 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
555 * here, dccp_create_openreq_child now does this for us, see the comment in
556 * that function for the gory details. -acme
557 */
558
559 /* It is tricky place. Until this moment IPv4 tcp
560 worked with IPv6 icsk.icsk_af_ops.
561 Sync it now.
562 */
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800563 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800564
565 return newsk;
566 }
567
568 opt = np->opt;
569
570 if (sk_acceptq_is_full(sk))
571 goto out_overflow;
572
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800573 if (np->rxopt.bits.osrcrt == 2 && opt == NULL && ireq6->pktopts) {
574 const struct inet6_skb_parm *rxopt = IP6CB(ireq6->pktopts);
575
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800576 if (rxopt->srcrt)
577 opt = ipv6_invert_rthdr(sk,
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700578 (struct ipv6_rt_hdr *)(skb_network_header(ireq6->pktopts) +
579 rxopt->srcrt));
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800580 }
581
582 if (dst == NULL) {
583 struct in6_addr *final_p = NULL, final;
584 struct flowi fl;
585
586 memset(&fl, 0, sizeof(fl));
587 fl.proto = IPPROTO_DCCP;
588 ipv6_addr_copy(&fl.fl6_dst, &ireq6->rmt_addr);
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800589 if (opt != NULL && opt->srcrt != NULL) {
590 const struct rt0_hdr *rt0 = (struct rt0_hdr *)opt->srcrt;
591
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800592 ipv6_addr_copy(&final, &fl.fl6_dst);
593 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
594 final_p = &final;
595 }
596 ipv6_addr_copy(&fl.fl6_src, &ireq6->loc_addr);
597 fl.oif = sk->sk_bound_dev_if;
598 fl.fl_ip_dport = inet_rsk(req)->rmt_port;
599 fl.fl_ip_sport = inet_sk(sk)->sport;
Venkat Yekkiralabeb8d132006-08-04 23:12:42 -0700600 security_sk_classify_flow(sk, &fl);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800601
602 if (ip6_dst_lookup(sk, &dst, &fl))
603 goto out;
604
605 if (final_p)
606 ipv6_addr_copy(&fl.fl6_dst, final_p);
607
608 if ((xfrm_lookup(&dst, &fl, sk, 0)) < 0)
609 goto out;
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800610 }
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800611
612 newsk = dccp_create_openreq_child(sk, req, skb);
613 if (newsk == NULL)
614 goto out;
615
616 /*
617 * No need to charge this sock to the relevant IPv6 refcnt debug socks
618 * count here, dccp_create_openreq_child now does this for us, see the
619 * comment in that function for the gory details. -acme
620 */
621
YOSHIFUJI Hideaki8e1ef0a2006-08-29 17:15:09 -0700622 __ip6_dst_store(newsk, dst, NULL, NULL);
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800623 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
624 NETIF_F_TSO);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800625 newdp6 = (struct dccp6_sock *)newsk;
626 newinet = inet_sk(newsk);
627 newinet->pinet6 = &newdp6->inet6;
628 newdp = dccp_sk(newsk);
629 newnp = inet6_sk(newsk);
630
631 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
632
633 ipv6_addr_copy(&newnp->daddr, &ireq6->rmt_addr);
634 ipv6_addr_copy(&newnp->saddr, &ireq6->loc_addr);
635 ipv6_addr_copy(&newnp->rcv_saddr, &ireq6->loc_addr);
636 newsk->sk_bound_dev_if = ireq6->iif;
637
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800638 /* Now IPv6 options...
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800639
640 First: no IPv4 options.
641 */
642 newinet->opt = NULL;
643
644 /* Clone RX bits */
645 newnp->rxopt.all = np->rxopt.all;
646
647 /* Clone pktoptions received with SYN */
648 newnp->pktoptions = NULL;
649 if (ireq6->pktopts != NULL) {
650 newnp->pktoptions = skb_clone(ireq6->pktopts, GFP_ATOMIC);
651 kfree_skb(ireq6->pktopts);
652 ireq6->pktopts = NULL;
653 if (newnp->pktoptions)
654 skb_set_owner_r(newnp->pktoptions, newsk);
655 }
656 newnp->opt = NULL;
657 newnp->mcast_oif = inet6_iif(skb);
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700658 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800659
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800660 /*
661 * Clone native IPv6 options from listening socket (if any)
662 *
663 * Yes, keeping reference count would be much more clever, but we make
664 * one more one thing there: reattach optmem to newsk.
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800665 */
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800666 if (opt != NULL) {
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800667 newnp->opt = ipv6_dup_options(newsk, opt);
668 if (opt != np->opt)
669 sock_kfree_s(sk, opt, opt->tot_len);
670 }
671
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800672 inet_csk(newsk)->icsk_ext_hdr_len = 0;
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800673 if (newnp->opt != NULL)
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800674 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
675 newnp->opt->opt_flen);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800676
677 dccp_sync_mss(newsk, dst_mtu(dst));
678
679 newinet->daddr = newinet->saddr = newinet->rcv_saddr = LOOPBACK4_IPV6;
680
681 __inet6_hash(&dccp_hashinfo, newsk);
682 inet_inherit_port(&dccp_hashinfo, sk, newsk);
683
684 return newsk;
685
686out_overflow:
687 NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
688out:
689 NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800690 if (opt != NULL && opt != np->opt)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800691 sock_kfree_s(sk, opt, opt->tot_len);
692 dst_release(dst);
693 return NULL;
694}
695
696/* The socket must have it's spinlock held when we get
697 * here.
698 *
699 * We have a potential double-lock case here, so even when
700 * doing backlog processing we use the BH locking scheme.
701 * This is because we cannot sleep with the original spinlock
702 * held.
703 */
704static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
705{
706 struct ipv6_pinfo *np = inet6_sk(sk);
707 struct sk_buff *opt_skb = NULL;
708
709 /* Imagine: socket is IPv6. IPv4 packet arrives,
710 goes to IPv4 receive handler and backlogged.
711 From backlog it always goes here. Kerboom...
712 Fortunately, dccp_rcv_established and rcv_established
713 handle them correctly, but it is not case with
714 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
715 */
716
717 if (skb->protocol == htons(ETH_P_IP))
718 return dccp_v4_do_rcv(sk, skb);
719
Dmitry Mishinfda9ef52006-08-31 15:28:39 -0700720 if (sk_filter(sk, skb))
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800721 goto discard;
722
723 /*
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800724 * socket locking is here for SMP purposes as backlog rcv is currently
725 * called with bh processing disabled.
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800726 */
727
728 /* Do Stevens' IPV6_PKTOPTIONS.
729
730 Yes, guys, it is the only place in our code, where we
731 may make it not affecting IPv4.
732 The rest of code is protocol independent,
733 and I do not like idea to uglify IPv4.
734
735 Actually, all the idea behind IPV6_PKTOPTIONS
736 looks not very well thought. For now we latch
737 options, received in the last packet, enqueued
738 by tcp. Feel free to propose better solution.
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900739 --ANK (980728)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800740 */
741 if (np->rxopt.all)
Gerrit Renker89e7e572006-11-10 11:13:33 -0200742 /*
743 * FIXME: Add handling of IPV6_PKTOPTIONS skb. See the comments below
744 * (wrt ipv6_pktopions) and net/ipv6/tcp_ipv6.c for an example.
745 */
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800746 opt_skb = skb_clone(skb, GFP_ATOMIC);
747
748 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
749 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
750 goto reset;
David S. Millerfd169f12006-10-20 19:44:17 -0700751 if (opt_skb) {
Gerrit Renker89e7e572006-11-10 11:13:33 -0200752 /* XXX This is where we would goto ipv6_pktoptions. */
David S. Millerfd169f12006-10-20 19:44:17 -0700753 __kfree_skb(opt_skb);
754 }
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800755 return 0;
756 }
757
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200758 /*
759 * Step 3: Process LISTEN state
760 * If S.state == LISTEN,
761 * If P.type == Request or P contains a valid Init Cookie option,
762 * (* Must scan the packet's options to check for Init
763 * Cookies. Only Init Cookies are processed here,
764 * however; other options are processed in Step 8. This
765 * scan need only be performed if the endpoint uses Init
766 * Cookies *)
767 * (* Generate a new socket and switch to that socket *)
768 * Set S := new socket for this port pair
769 * S.state = RESPOND
770 * Choose S.ISS (initial seqno) or set from Init Cookies
771 * Initialize S.GAR := S.ISS
772 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
773 * Continue with S.state == RESPOND
774 * (* A Response packet will be generated in Step 11 *)
775 * Otherwise,
776 * Generate Reset(No Connection) unless P.type == Reset
777 * Drop packet and return
778 *
779 * NOTE: the check for the packet types is done in
780 * dccp_rcv_state_process
781 */
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800782 if (sk->sk_state == DCCP_LISTEN) {
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800783 struct sock *nsk = dccp_v6_hnd_req(sk, skb);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800784
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800785 if (nsk == NULL)
786 goto discard;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800787 /*
788 * Queue it on the new socket if the new socket is active,
789 * otherwise we just shortcircuit this and continue with
790 * the new socket..
791 */
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200792 if (nsk != sk) {
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800793 if (dccp_child_process(sk, nsk, skb))
794 goto reset;
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800795 if (opt_skb != NULL)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800796 __kfree_skb(opt_skb);
797 return 0;
798 }
799 }
800
801 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
802 goto reset;
David S. Millerfd169f12006-10-20 19:44:17 -0700803 if (opt_skb) {
Gerrit Renker89e7e572006-11-10 11:13:33 -0200804 /* XXX This is where we would goto ipv6_pktoptions. */
David S. Millerfd169f12006-10-20 19:44:17 -0700805 __kfree_skb(opt_skb);
806 }
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800807 return 0;
808
809reset:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800810 dccp_v6_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800811discard:
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800812 if (opt_skb != NULL)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800813 __kfree_skb(opt_skb);
814 kfree_skb(skb);
815 return 0;
816}
817
Patrick McHardy951dbc82006-01-06 23:02:34 -0800818static int dccp_v6_rcv(struct sk_buff **pskb)
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800819{
820 const struct dccp_hdr *dh;
821 struct sk_buff *skb = *pskb;
822 struct sock *sk;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200823 int min_cov;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800824
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200825 /* Step 1: Check header basics */
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800826
827 if (dccp_invalid_packet(skb))
828 goto discard_it;
829
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200830 /* Step 1: If header checksum is incorrect, drop packet and return. */
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700831 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
832 &ipv6_hdr(skb)->daddr)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200833 DCCP_WARN("dropped packet with invalid checksum\n");
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200834 goto discard_it;
835 }
836
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800837 dh = dccp_hdr(skb);
838
839 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(skb);
840 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
841
842 if (dccp_packet_without_ack(skb))
843 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
844 else
845 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
846
847 /* Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200848 * Look up flow ID in table and get corresponding socket */
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700849 sk = __inet6_lookup(&dccp_hashinfo, &ipv6_hdr(skb)->saddr,
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800850 dh->dccph_sport,
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700851 &ipv6_hdr(skb)->daddr, ntohs(dh->dccph_dport),
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800852 inet6_iif(skb));
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800853 /*
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800854 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200855 * If no socket ...
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800856 */
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200857 if (sk == NULL) {
858 dccp_pr_debug("failed to look up flow ID in table and "
859 "get corresponding socket\n");
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800860 goto no_dccp_socket;
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200861 }
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800862
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -0800863 /*
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800864 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200865 * ... or S.state == TIMEWAIT,
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800866 * Generate Reset(No Connection) unless P.type == Reset
867 * Drop packet and return
868 */
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200869 if (sk->sk_state == DCCP_TIME_WAIT) {
870 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
871 inet_twsk_put(inet_twsk(sk));
872 goto no_dccp_socket;
873 }
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800874
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200875 /*
876 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200877 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
878 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200879 */
880 min_cov = dccp_sk(sk)->dccps_pcrlen;
881 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
882 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
883 dh->dccph_cscov, min_cov);
884 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
885 goto discard_and_relse;
886 }
887
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800888 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
889 goto discard_and_relse;
890
Arnaldo Carvalho de Melo58a5a7b2006-11-16 14:06:06 -0200891 return sk_receive_skb(sk, skb, 1) ? -1 : 0;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800892
893no_dccp_socket:
894 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
895 goto discard_it;
896 /*
897 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200898 * If no socket ...
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800899 * Generate Reset(No Connection) unless P.type == Reset
900 * Drop packet and return
901 */
902 if (dh->dccph_type != DCCP_PKT_RESET) {
903 DCCP_SKB_CB(skb)->dccpd_reset_code =
904 DCCP_RESET_CODE_NO_CONNECTION;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800905 dccp_v6_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800906 }
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200907
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800908discard_it:
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800909 kfree_skb(skb);
910 return 0;
911
912discard_and_relse:
913 sock_put(sk);
914 goto discard_it;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -0800915}
916
Gerrit Renker73c9e022006-11-10 13:01:31 -0200917static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
918 int addr_len)
919{
920 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
921 struct inet_connection_sock *icsk = inet_csk(sk);
922 struct inet_sock *inet = inet_sk(sk);
923 struct ipv6_pinfo *np = inet6_sk(sk);
924 struct dccp_sock *dp = dccp_sk(sk);
925 struct in6_addr *saddr = NULL, *final_p = NULL, final;
926 struct flowi fl;
927 struct dst_entry *dst;
928 int addr_type;
929 int err;
930
931 dp->dccps_role = DCCP_ROLE_CLIENT;
932
933 if (addr_len < SIN6_LEN_RFC2133)
934 return -EINVAL;
935
936 if (usin->sin6_family != AF_INET6)
937 return -EAFNOSUPPORT;
938
939 memset(&fl, 0, sizeof(fl));
940
941 if (np->sndflow) {
942 fl.fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
943 IP6_ECN_flow_init(fl.fl6_flowlabel);
944 if (fl.fl6_flowlabel & IPV6_FLOWLABEL_MASK) {
945 struct ip6_flowlabel *flowlabel;
946 flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
947 if (flowlabel == NULL)
948 return -EINVAL;
949 ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
950 fl6_sock_release(flowlabel);
951 }
952 }
953 /*
954 * connect() to INADDR_ANY means loopback (BSD'ism).
955 */
956 if (ipv6_addr_any(&usin->sin6_addr))
957 usin->sin6_addr.s6_addr[15] = 1;
958
959 addr_type = ipv6_addr_type(&usin->sin6_addr);
960
961 if (addr_type & IPV6_ADDR_MULTICAST)
962 return -ENETUNREACH;
963
964 if (addr_type & IPV6_ADDR_LINKLOCAL) {
965 if (addr_len >= sizeof(struct sockaddr_in6) &&
966 usin->sin6_scope_id) {
967 /* If interface is set while binding, indices
968 * must coincide.
969 */
970 if (sk->sk_bound_dev_if &&
971 sk->sk_bound_dev_if != usin->sin6_scope_id)
972 return -EINVAL;
973
974 sk->sk_bound_dev_if = usin->sin6_scope_id;
975 }
976
977 /* Connect to link-local address requires an interface */
978 if (!sk->sk_bound_dev_if)
979 return -EINVAL;
980 }
981
982 ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
983 np->flow_label = fl.fl6_flowlabel;
984
985 /*
986 * DCCP over IPv4
987 */
988 if (addr_type == IPV6_ADDR_MAPPED) {
989 u32 exthdrlen = icsk->icsk_ext_hdr_len;
990 struct sockaddr_in sin;
991
992 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
993
994 if (__ipv6_only_sock(sk))
995 return -ENETUNREACH;
996
997 sin.sin_family = AF_INET;
998 sin.sin_port = usin->sin6_port;
999 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
1000
1001 icsk->icsk_af_ops = &dccp_ipv6_mapped;
1002 sk->sk_backlog_rcv = dccp_v4_do_rcv;
1003
1004 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
1005 if (err) {
1006 icsk->icsk_ext_hdr_len = exthdrlen;
1007 icsk->icsk_af_ops = &dccp_ipv6_af_ops;
1008 sk->sk_backlog_rcv = dccp_v6_do_rcv;
1009 goto failure;
1010 } else {
1011 ipv6_addr_set(&np->saddr, 0, 0, htonl(0x0000FFFF),
1012 inet->saddr);
1013 ipv6_addr_set(&np->rcv_saddr, 0, 0, htonl(0x0000FFFF),
1014 inet->rcv_saddr);
1015 }
1016
1017 return err;
1018 }
1019
1020 if (!ipv6_addr_any(&np->rcv_saddr))
1021 saddr = &np->rcv_saddr;
1022
1023 fl.proto = IPPROTO_DCCP;
1024 ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
1025 ipv6_addr_copy(&fl.fl6_src, saddr ? saddr : &np->saddr);
1026 fl.oif = sk->sk_bound_dev_if;
1027 fl.fl_ip_dport = usin->sin6_port;
1028 fl.fl_ip_sport = inet->sport;
1029 security_sk_classify_flow(sk, &fl);
1030
1031 if (np->opt != NULL && np->opt->srcrt != NULL) {
1032 const struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
1033
1034 ipv6_addr_copy(&final, &fl.fl6_dst);
1035 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
1036 final_p = &final;
1037 }
1038
1039 err = ip6_dst_lookup(sk, &dst, &fl);
1040 if (err)
1041 goto failure;
1042
1043 if (final_p)
1044 ipv6_addr_copy(&fl.fl6_dst, final_p);
1045
David S. Miller14e50e52007-05-24 18:17:54 -07001046 err = __xfrm_lookup(&dst, &fl, sk, 1);
1047 if (err < 0) {
1048 if (err == -EREMOTE)
1049 err = ip6_dst_blackhole(sk, &dst, &fl);
1050 if (err < 0)
1051 goto failure;
1052 }
Gerrit Renker73c9e022006-11-10 13:01:31 -02001053
1054 if (saddr == NULL) {
1055 saddr = &fl.fl6_src;
1056 ipv6_addr_copy(&np->rcv_saddr, saddr);
1057 }
1058
1059 /* set the source address */
1060 ipv6_addr_copy(&np->saddr, saddr);
1061 inet->rcv_saddr = LOOPBACK4_IPV6;
1062
1063 __ip6_dst_store(sk, dst, NULL, NULL);
1064
1065 icsk->icsk_ext_hdr_len = 0;
1066 if (np->opt != NULL)
1067 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
1068 np->opt->opt_nflen);
1069
1070 inet->dport = usin->sin6_port;
1071
1072 dccp_set_state(sk, DCCP_REQUESTING);
1073 err = inet6_hash_connect(&dccp_death_row, sk);
1074 if (err)
1075 goto late_failure;
Gerrit Renkerd7f73652006-11-13 13:34:38 -02001076
1077 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
1078 np->daddr.s6_addr32,
1079 inet->sport, inet->dport);
Gerrit Renker73c9e022006-11-10 13:01:31 -02001080 err = dccp_connect(sk);
1081 if (err)
1082 goto late_failure;
1083
1084 return 0;
1085
1086late_failure:
1087 dccp_set_state(sk, DCCP_CLOSED);
1088 __sk_dst_reset(sk);
1089failure:
1090 inet->dport = 0;
1091 sk->sk_route_caps = 0;
1092 return err;
1093}
1094
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001095static struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001096 .queue_xmit = inet6_csk_xmit,
1097 .send_check = dccp_v6_send_check,
1098 .rebuild_header = inet6_sk_rebuild_header,
1099 .conn_request = dccp_v6_conn_request,
1100 .syn_recv_sock = dccp_v6_request_recv_sock,
1101 .net_header_len = sizeof(struct ipv6hdr),
1102 .setsockopt = ipv6_setsockopt,
1103 .getsockopt = ipv6_getsockopt,
1104 .addr2sockaddr = inet6_csk_addr2sockaddr,
1105 .sockaddr_len = sizeof(struct sockaddr_in6),
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001106#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001107 .compat_setsockopt = compat_ipv6_setsockopt,
1108 .compat_getsockopt = compat_ipv6_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001109#endif
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001110};
1111
1112/*
1113 * DCCP over IPv4 via INET6 API
1114 */
1115static struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001116 .queue_xmit = ip_queue_xmit,
1117 .send_check = dccp_v4_send_check,
1118 .rebuild_header = inet_sk_rebuild_header,
1119 .conn_request = dccp_v6_conn_request,
1120 .syn_recv_sock = dccp_v6_request_recv_sock,
1121 .net_header_len = sizeof(struct iphdr),
1122 .setsockopt = ipv6_setsockopt,
1123 .getsockopt = ipv6_getsockopt,
1124 .addr2sockaddr = inet6_csk_addr2sockaddr,
1125 .sockaddr_len = sizeof(struct sockaddr_in6),
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001126#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001127 .compat_setsockopt = compat_ipv6_setsockopt,
1128 .compat_getsockopt = compat_ipv6_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001129#endif
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001130};
1131
1132/* NOTE: A lot of things set to zero explicitly by call to
1133 * sk_alloc() so need not be done here.
1134 */
1135static int dccp_v6_init_sock(struct sock *sk)
1136{
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -08001137 static __u8 dccp_v6_ctl_sock_initialized;
1138 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001139
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -08001140 if (err == 0) {
1141 if (unlikely(!dccp_v6_ctl_sock_initialized))
1142 dccp_v6_ctl_sock_initialized = 1;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001143 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -08001144 }
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001145
1146 return err;
1147}
1148
1149static int dccp_v6_destroy_sock(struct sock *sk)
1150{
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -08001151 dccp_destroy_sock(sk);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001152 return inet6_destroy_sock(sk);
1153}
1154
Gerrit Renker73c9e022006-11-10 13:01:31 -02001155static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1156 .twsk_obj_size = sizeof(struct dccp6_timewait_sock),
1157};
1158
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001159static struct proto dccp_v6_prot = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001160 .name = "DCCPv6",
1161 .owner = THIS_MODULE,
1162 .close = dccp_close,
1163 .connect = dccp_v6_connect,
1164 .disconnect = dccp_disconnect,
1165 .ioctl = dccp_ioctl,
1166 .init = dccp_v6_init_sock,
1167 .setsockopt = dccp_setsockopt,
1168 .getsockopt = dccp_getsockopt,
1169 .sendmsg = dccp_sendmsg,
1170 .recvmsg = dccp_recvmsg,
1171 .backlog_rcv = dccp_v6_do_rcv,
1172 .hash = dccp_v6_hash,
1173 .unhash = dccp_unhash,
1174 .accept = inet_csk_accept,
1175 .get_port = dccp_v6_get_port,
1176 .shutdown = dccp_shutdown,
1177 .destroy = dccp_v6_destroy_sock,
1178 .orphan_count = &dccp_orphan_count,
1179 .max_header = MAX_DCCP_HEADER,
1180 .obj_size = sizeof(struct dccp6_sock),
1181 .rsk_prot = &dccp6_request_sock_ops,
1182 .twsk_prot = &dccp6_timewait_sock_ops,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001183#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001184 .compat_setsockopt = compat_dccp_setsockopt,
1185 .compat_getsockopt = compat_dccp_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001186#endif
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001187};
1188
1189static struct inet6_protocol dccp_v6_protocol = {
Arnaldo Carvalho de Melo45329e72006-03-20 22:01:29 -08001190 .handler = dccp_v6_rcv,
1191 .err_handler = dccp_v6_err,
1192 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001193};
1194
1195static struct proto_ops inet6_dccp_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001196 .family = PF_INET6,
1197 .owner = THIS_MODULE,
1198 .release = inet6_release,
1199 .bind = inet6_bind,
1200 .connect = inet_stream_connect,
1201 .socketpair = sock_no_socketpair,
1202 .accept = inet_accept,
1203 .getname = inet6_getname,
1204 .poll = dccp_poll,
1205 .ioctl = inet6_ioctl,
1206 .listen = inet_dccp_listen,
1207 .shutdown = inet_shutdown,
1208 .setsockopt = sock_common_setsockopt,
1209 .getsockopt = sock_common_getsockopt,
1210 .sendmsg = inet_sendmsg,
1211 .recvmsg = sock_common_recvmsg,
1212 .mmap = sock_no_mmap,
1213 .sendpage = sock_no_sendpage,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001214#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001215 .compat_setsockopt = compat_sock_common_setsockopt,
1216 .compat_getsockopt = compat_sock_common_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001217#endif
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001218};
1219
1220static struct inet_protosw dccp_v6_protosw = {
1221 .type = SOCK_DCCP,
1222 .protocol = IPPROTO_DCCP,
1223 .prot = &dccp_v6_prot,
1224 .ops = &inet6_dccp_ops,
1225 .capability = -1,
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -08001226 .flags = INET_PROTOSW_ICSK,
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001227};
1228
1229static int __init dccp_v6_init(void)
1230{
1231 int err = proto_register(&dccp_v6_prot, 1);
1232
1233 if (err != 0)
1234 goto out;
1235
1236 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1237 if (err != 0)
1238 goto out_unregister_proto;
1239
1240 inet6_register_protosw(&dccp_v6_protosw);
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -08001241
Arnaldo Carvalho de Meloc4d93902006-03-20 22:01:03 -08001242 err = inet_csk_ctl_sock_create(&dccp_v6_ctl_socket, PF_INET6,
1243 SOCK_DCCP, IPPROTO_DCCP);
1244 if (err != 0)
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -08001245 goto out_unregister_protosw;
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001246out:
1247 return err;
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -08001248out_unregister_protosw:
1249 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1250 inet6_unregister_protosw(&dccp_v6_protosw);
Arnaldo Carvalho de Melo3df80d92005-12-13 23:24:53 -08001251out_unregister_proto:
1252 proto_unregister(&dccp_v6_prot);
1253 goto out;
1254}
1255
1256static void __exit dccp_v6_exit(void)
1257{
1258 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1259 inet6_unregister_protosw(&dccp_v6_protosw);
1260 proto_unregister(&dccp_v6_prot);
1261}
1262
1263module_init(dccp_v6_init);
1264module_exit(dccp_v6_exit);
1265
1266/*
1267 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1268 * values directly, Also cover the case where the protocol is not specified,
1269 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1270 */
1271MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-33-type-6");
1272MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-0-type-6");
1273MODULE_LICENSE("GPL");
1274MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1275MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");