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/icmp.h>
15 #include <linux/module.h>
16 #include <linux/skbuff.h>
17 #include <linux/random.h>
20 #include <net/inet_common.h>
21 #include <net/inet_hashtables.h>
22 #include <net/inet_sock.h>
23 #include <net/protocol.h>
25 #include <net/timewait_sock.h>
26 #include <net/tcp_states.h>
35 * The per-net dccp.v4_ctl_sk socket is used for responding to
36 * the Out-of-the-blue (OOTB) packets. A control sock will be created
37 * for this socket at the initialization time.
40 int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
42 struct inet_sock *inet = inet_sk(sk);
43 struct dccp_sock *dp = dccp_sk(sk);
44 const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
46 __be32 daddr, nexthop;
50 dp->dccps_role = DCCP_ROLE_CLIENT;
52 if (addr_len < sizeof(struct sockaddr_in))
55 if (usin->sin_family != AF_INET)
58 nexthop = daddr = usin->sin_addr.s_addr;
59 if (inet->opt != NULL && inet->opt->srr) {
62 nexthop = inet->opt->faddr;
65 tmp = ip_route_connect(&rt, nexthop, inet->saddr,
66 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
68 inet->sport, usin->sin_port, sk, 1);
72 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
77 if (inet->opt == NULL || !inet->opt->srr)
81 inet->saddr = rt->rt_src;
82 inet->rcv_saddr = inet->saddr;
84 inet->dport = usin->sin_port;
87 inet_csk(sk)->icsk_ext_hdr_len = 0;
88 if (inet->opt != NULL)
89 inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
91 * Socket identity is still unknown (sport may be zero).
92 * However we set state to DCCP_REQUESTING and not releasing socket
93 * lock select source port, enter ourselves into the hash tables and
94 * complete initialization after this.
96 dccp_set_state(sk, DCCP_REQUESTING);
97 err = inet_hash_connect(&dccp_death_row, sk);
101 err = ip_route_newports(&rt, IPPROTO_DCCP, inet->sport, inet->dport,
106 /* OK, now commit destination to socket. */
107 sk_setup_caps(sk, &rt->u.dst);
109 dp->dccps_iss = secure_dccp_sequence_number(inet->saddr, inet->daddr,
110 inet->sport, inet->dport);
111 inet->id = dp->dccps_iss ^ jiffies;
113 err = dccp_connect(sk);
121 * This unhashes the socket and releases the local port, if necessary.
123 dccp_set_state(sk, DCCP_CLOSED);
125 sk->sk_route_caps = 0;
130 EXPORT_SYMBOL_GPL(dccp_v4_connect);
133 * This routine does path mtu discovery as defined in RFC1191.
135 static inline void dccp_do_pmtu_discovery(struct sock *sk,
136 const struct iphdr *iph,
139 struct dst_entry *dst;
140 const struct inet_sock *inet = inet_sk(sk);
141 const struct dccp_sock *dp = dccp_sk(sk);
143 /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs
144 * send out by Linux are always < 576bytes so they should go through
147 if (sk->sk_state == DCCP_LISTEN)
150 /* We don't check in the destentry if pmtu discovery is forbidden
151 * on this route. We just assume that no packet_to_big packets
152 * are send back when pmtu discovery is not active.
153 * There is a small race when the user changes this flag in the
154 * route, but I think that's acceptable.
156 if ((dst = __sk_dst_check(sk, 0)) == NULL)
159 dst->ops->update_pmtu(dst, mtu);
161 /* Something is about to be wrong... Remember soft error
162 * for the case, if this connection will not able to recover.
164 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
165 sk->sk_err_soft = EMSGSIZE;
169 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
170 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
171 dccp_sync_mss(sk, mtu);
174 * From RFC 4340, sec. 14.1:
176 * DCCP-Sync packets are the best choice for upward
177 * probing, since DCCP-Sync probes do not risk application
180 dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC);
181 } /* else let the usual retransmit timer handle it */
185 * This routine is called by the ICMP module when it gets some sort of error
186 * condition. If err < 0 then the socket should be closed and the error
187 * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code.
188 * After adjustment header points to the first 8 bytes of the tcp header. We
189 * need to find the appropriate port.
191 * The locking strategy used here is very "optimistic". When someone else
192 * accesses the socket the ICMP is just dropped and for some paths there is no
193 * check at all. A more general error queue to queue errors for later handling
194 * is probably better.
196 static void dccp_v4_err(struct sk_buff *skb, u32 info)
198 const struct iphdr *iph = (struct iphdr *)skb->data;
199 const u8 offset = iph->ihl << 2;
200 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset);
201 struct dccp_sock *dp;
202 struct inet_sock *inet;
203 const int type = icmp_hdr(skb)->type;
204 const int code = icmp_hdr(skb)->code;
208 struct net *net = dev_net(skb->dev);
210 if (skb->len < offset + sizeof(*dh) ||
211 skb->len < offset + __dccp_basic_hdr_len(dh)) {
212 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
216 sk = inet_lookup(net, &dccp_hashinfo,
217 iph->daddr, dh->dccph_dport,
218 iph->saddr, dh->dccph_sport, inet_iif(skb));
220 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
224 if (sk->sk_state == DCCP_TIME_WAIT) {
225 inet_twsk_put(inet_twsk(sk));
230 /* If too many ICMPs get dropped on busy
231 * servers this needs to be solved differently.
233 if (sock_owned_by_user(sk))
234 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
236 if (sk->sk_state == DCCP_CLOSED)
240 seq = dccp_hdr_seq(dh);
241 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
242 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
243 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
248 case ICMP_SOURCE_QUENCH:
249 /* Just silently ignore these. */
251 case ICMP_PARAMETERPROB:
254 case ICMP_DEST_UNREACH:
255 if (code > NR_ICMP_UNREACH)
258 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
259 if (!sock_owned_by_user(sk))
260 dccp_do_pmtu_discovery(sk, iph, info);
264 err = icmp_err_convert[code].errno;
266 case ICMP_TIME_EXCEEDED:
273 switch (sk->sk_state) {
274 struct request_sock *req , **prev;
276 if (sock_owned_by_user(sk))
278 req = inet_csk_search_req(sk, &prev, dh->dccph_dport,
279 iph->daddr, iph->saddr);
284 * ICMPs are not backlogged, hence we cannot get an established
289 if (seq != dccp_rsk(req)->dreq_iss) {
290 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
294 * Still in RESPOND, just remove it silently.
295 * There is no good way to pass the error to the newly
296 * created socket, and POSIX does not want network
297 * errors returned from accept().
299 inet_csk_reqsk_queue_drop(sk, req, prev);
302 case DCCP_REQUESTING:
304 if (!sock_owned_by_user(sk)) {
305 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
308 sk->sk_error_report(sk);
312 sk->sk_err_soft = err;
316 /* If we've already connected we will keep trying
317 * until we time out, or the user gives up.
319 * rfc1122 4.2.3.9 allows to consider as hard errors
320 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
321 * but it is obsoleted by pmtu discovery).
323 * Note, that in modern internet, where routing is unreliable
324 * and in each dark corner broken firewalls sit, sending random
325 * errors ordered by their masters even this two messages finally lose
326 * their original sense (even Linux sends invalid PORT_UNREACHs)
328 * Now we are in compliance with RFCs.
333 if (!sock_owned_by_user(sk) && inet->recverr) {
335 sk->sk_error_report(sk);
336 } else /* Only an error on timeout */
337 sk->sk_err_soft = err;
343 static inline __sum16 dccp_v4_csum_finish(struct sk_buff *skb,
344 __be32 src, __be32 dst)
346 return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum);
349 void dccp_v4_send_check(struct sock *sk, int unused, struct sk_buff *skb)
351 const struct inet_sock *inet = inet_sk(sk);
352 struct dccp_hdr *dh = dccp_hdr(skb);
354 dccp_csum_outgoing(skb);
355 dh->dccph_checksum = dccp_v4_csum_finish(skb, inet->saddr, inet->daddr);
358 EXPORT_SYMBOL_GPL(dccp_v4_send_check);
360 static inline u64 dccp_v4_init_sequence(const struct sk_buff *skb)
362 return secure_dccp_sequence_number(ip_hdr(skb)->daddr,
364 dccp_hdr(skb)->dccph_dport,
365 dccp_hdr(skb)->dccph_sport);
369 * The three way handshake has completed - we got a valid ACK or DATAACK -
370 * now create the new socket.
372 * This is the equivalent of TCP's tcp_v4_syn_recv_sock
374 struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
375 struct request_sock *req,
376 struct dst_entry *dst)
378 struct inet_request_sock *ireq;
379 struct inet_sock *newinet;
382 if (sk_acceptq_is_full(sk))
385 if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
388 newsk = dccp_create_openreq_child(sk, req, skb);
392 sk_setup_caps(newsk, dst);
394 newinet = inet_sk(newsk);
395 ireq = inet_rsk(req);
396 newinet->daddr = ireq->rmt_addr;
397 newinet->rcv_saddr = ireq->loc_addr;
398 newinet->saddr = ireq->loc_addr;
399 newinet->opt = ireq->opt;
401 newinet->mc_index = inet_iif(skb);
402 newinet->mc_ttl = ip_hdr(skb)->ttl;
403 newinet->id = jiffies;
405 dccp_sync_mss(newsk, dst_mtu(dst));
407 __inet_hash_nolisten(newsk);
408 __inet_inherit_port(sk, newsk);
413 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
415 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
420 EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock);
422 static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
424 const struct dccp_hdr *dh = dccp_hdr(skb);
425 const struct iphdr *iph = ip_hdr(skb);
427 struct request_sock **prev;
428 /* Find possible connection requests. */
429 struct request_sock *req = inet_csk_search_req(sk, &prev,
431 iph->saddr, iph->daddr);
433 return dccp_check_req(sk, skb, req, prev);
435 nsk = inet_lookup_established(sock_net(sk), &dccp_hashinfo,
436 iph->saddr, dh->dccph_sport,
437 iph->daddr, dh->dccph_dport,
440 if (nsk->sk_state != DCCP_TIME_WAIT) {
444 inet_twsk_put(inet_twsk(nsk));
451 static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk,
455 struct flowi fl = { .oif = skb_rtable(skb)->rt_iif,
457 { .daddr = ip_hdr(skb)->saddr,
458 .saddr = ip_hdr(skb)->daddr,
459 .tos = RT_CONN_FLAGS(sk) } },
460 .proto = sk->sk_protocol,
462 { .sport = dccp_hdr(skb)->dccph_dport,
463 .dport = dccp_hdr(skb)->dccph_sport }
467 security_skb_classify_flow(skb, &fl);
468 if (ip_route_output_flow(net, &rt, &fl, sk, 0)) {
469 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
476 static int dccp_v4_send_response(struct sock *sk, struct request_sock *req)
480 struct dst_entry *dst;
482 dst = inet_csk_route_req(sk, req);
486 skb = dccp_make_response(sk, dst, req);
488 const struct inet_request_sock *ireq = inet_rsk(req);
489 struct dccp_hdr *dh = dccp_hdr(skb);
491 dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr,
493 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
496 err = net_xmit_eval(err);
504 static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
507 const struct iphdr *rxiph;
509 struct dst_entry *dst;
510 struct net *net = dev_net(skb_dst(rxskb)->dev);
511 struct sock *ctl_sk = net->dccp.v4_ctl_sk;
513 /* Never send a reset in response to a reset. */
514 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
517 if (skb_rtable(rxskb)->rt_type != RTN_LOCAL)
520 dst = dccp_v4_route_skb(net, ctl_sk, rxskb);
524 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
528 rxiph = ip_hdr(rxskb);
529 dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
531 skb_dst_set(skb, dst_clone(dst));
533 bh_lock_sock(ctl_sk);
534 err = ip_build_and_send_pkt(skb, ctl_sk,
535 rxiph->daddr, rxiph->saddr, NULL);
536 bh_unlock_sock(ctl_sk);
538 if (net_xmit_eval(err) == 0) {
539 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
540 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
546 static void dccp_v4_reqsk_destructor(struct request_sock *req)
548 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
549 kfree(inet_rsk(req)->opt);
552 static struct request_sock_ops dccp_request_sock_ops __read_mostly = {
554 .obj_size = sizeof(struct dccp_request_sock),
555 .rtx_syn_ack = dccp_v4_send_response,
556 .send_ack = dccp_reqsk_send_ack,
557 .destructor = dccp_v4_reqsk_destructor,
558 .send_reset = dccp_v4_ctl_send_reset,
561 int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
563 struct inet_request_sock *ireq;
564 struct request_sock *req;
565 struct dccp_request_sock *dreq;
566 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
567 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
569 /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
570 if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
571 return 0; /* discard, don't send a reset here */
573 if (dccp_bad_service_code(sk, service)) {
574 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
578 * TW buckets are converted to open requests without
579 * limitations, they conserve resources and peer is
580 * evidently real one.
582 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
583 if (inet_csk_reqsk_queue_is_full(sk))
587 * Accept backlog is full. If we have already queued enough
588 * of warm entries in syn queue, drop request. It is better than
589 * clogging syn queue with openreqs with exponentially increasing
592 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
595 req = inet_reqsk_alloc(&dccp_request_sock_ops);
599 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
602 dreq = dccp_rsk(req);
603 if (dccp_parse_options(sk, dreq, skb))
606 if (security_inet_conn_request(sk, skb, req))
609 ireq = inet_rsk(req);
610 ireq->loc_addr = ip_hdr(skb)->daddr;
611 ireq->rmt_addr = ip_hdr(skb)->saddr;
614 * Step 3: Process LISTEN state
616 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
618 * In fact we defer setting S.GSR, S.SWL, S.SWH to
619 * dccp_create_openreq_child.
621 dreq->dreq_isr = dcb->dccpd_seq;
622 dreq->dreq_iss = dccp_v4_init_sequence(skb);
623 dreq->dreq_service = service;
625 if (dccp_v4_send_response(sk, req))
628 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
634 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
638 EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
640 int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
642 struct dccp_hdr *dh = dccp_hdr(skb);
644 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
645 if (dccp_rcv_established(sk, skb, dh, skb->len))
651 * Step 3: Process LISTEN state
652 * If P.type == Request or P contains a valid Init Cookie option,
653 * (* Must scan the packet's options to check for Init
654 * Cookies. Only Init Cookies are processed here,
655 * however; other options are processed in Step 8. This
656 * scan need only be performed if the endpoint uses Init
658 * (* Generate a new socket and switch to that socket *)
659 * Set S := new socket for this port pair
661 * Choose S.ISS (initial seqno) or set from Init Cookies
662 * Initialize S.GAR := S.ISS
663 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
664 * Continue with S.state == RESPOND
665 * (* A Response packet will be generated in Step 11 *)
667 * Generate Reset(No Connection) unless P.type == Reset
668 * Drop packet and return
670 * NOTE: the check for the packet types is done in
671 * dccp_rcv_state_process
673 if (sk->sk_state == DCCP_LISTEN) {
674 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
680 if (dccp_child_process(sk, nsk, skb))
686 if (dccp_rcv_state_process(sk, skb, dh, skb->len))
691 dccp_v4_ctl_send_reset(sk, skb);
697 EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
700 * dccp_invalid_packet - check for malformed packets
701 * Implements RFC 4340, 8.5: Step 1: Check header basics
702 * Packets that fail these checks are ignored and do not receive Resets.
704 int dccp_invalid_packet(struct sk_buff *skb)
706 const struct dccp_hdr *dh;
709 if (skb->pkt_type != PACKET_HOST)
712 /* If the packet is shorter than 12 bytes, drop packet and return */
713 if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
714 DCCP_WARN("pskb_may_pull failed\n");
720 /* If P.type is not understood, drop packet and return */
721 if (dh->dccph_type >= DCCP_PKT_INVALID) {
722 DCCP_WARN("invalid packet type\n");
727 * If P.Data Offset is too small for packet type, drop packet and return
729 if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
730 DCCP_WARN("P.Data Offset(%u) too small\n", dh->dccph_doff);
734 * If P.Data Offset is too too large for packet, drop packet and return
736 if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
737 DCCP_WARN("P.Data Offset(%u) too large\n", dh->dccph_doff);
742 * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
743 * has short sequence numbers), drop packet and return
745 if ((dh->dccph_type < DCCP_PKT_DATA ||
746 dh->dccph_type > DCCP_PKT_DATAACK) && dh->dccph_x == 0) {
747 DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n",
748 dccp_packet_name(dh->dccph_type));
753 * If P.CsCov is too large for the packet size, drop packet and return.
754 * This must come _before_ checksumming (not as RFC 4340 suggests).
756 cscov = dccp_csum_coverage(skb);
757 if (cscov > skb->len) {
758 DCCP_WARN("P.CsCov %u exceeds packet length %d\n",
759 dh->dccph_cscov, skb->len);
763 /* If header checksum is incorrect, drop packet and return.
764 * (This step is completed in the AF-dependent functions.) */
765 skb->csum = skb_checksum(skb, 0, cscov, 0);
770 EXPORT_SYMBOL_GPL(dccp_invalid_packet);
772 /* this is called when real data arrives */
773 static int dccp_v4_rcv(struct sk_buff *skb)
775 const struct dccp_hdr *dh;
776 const struct iphdr *iph;
780 /* Step 1: Check header basics */
782 if (dccp_invalid_packet(skb))
786 /* Step 1: If header checksum is incorrect, drop packet and return */
787 if (dccp_v4_csum_finish(skb, iph->saddr, iph->daddr)) {
788 DCCP_WARN("dropped packet with invalid checksum\n");
794 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
795 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
797 dccp_pr_debug("%8.8s src=%pI4@%-5d dst=%pI4@%-5d seq=%llu",
798 dccp_packet_name(dh->dccph_type),
799 &iph->saddr, ntohs(dh->dccph_sport),
800 &iph->daddr, ntohs(dh->dccph_dport),
801 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
803 if (dccp_packet_without_ack(skb)) {
804 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
805 dccp_pr_debug_cat("\n");
807 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
808 dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long)
809 DCCP_SKB_CB(skb)->dccpd_ack_seq);
813 * Look up flow ID in table and get corresponding socket */
814 sk = __inet_lookup_skb(&dccp_hashinfo, skb,
815 dh->dccph_sport, dh->dccph_dport);
821 dccp_pr_debug("failed to look up flow ID in table and "
822 "get corresponding socket\n");
828 * ... or S.state == TIMEWAIT,
829 * Generate Reset(No Connection) unless P.type == Reset
830 * Drop packet and return
832 if (sk->sk_state == DCCP_TIME_WAIT) {
833 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
834 inet_twsk_put(inet_twsk(sk));
839 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
840 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
841 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
843 min_cov = dccp_sk(sk)->dccps_pcrlen;
844 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
845 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
846 dh->dccph_cscov, min_cov);
847 /* FIXME: "Such packets SHOULD be reported using Data Dropped
848 * options (Section 11.7) with Drop Code 0, Protocol
850 goto discard_and_relse;
853 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
854 goto discard_and_relse;
857 return sk_receive_skb(sk, skb, 1);
860 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
865 * Generate Reset(No Connection) unless P.type == Reset
866 * Drop packet and return
868 if (dh->dccph_type != DCCP_PKT_RESET) {
869 DCCP_SKB_CB(skb)->dccpd_reset_code =
870 DCCP_RESET_CODE_NO_CONNECTION;
871 dccp_v4_ctl_send_reset(sk, skb);
883 static struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
884 .queue_xmit = ip_queue_xmit,
885 .send_check = dccp_v4_send_check,
886 .rebuild_header = inet_sk_rebuild_header,
887 .conn_request = dccp_v4_conn_request,
888 .syn_recv_sock = dccp_v4_request_recv_sock,
889 .net_header_len = sizeof(struct iphdr),
890 .setsockopt = ip_setsockopt,
891 .getsockopt = ip_getsockopt,
892 .addr2sockaddr = inet_csk_addr2sockaddr,
893 .sockaddr_len = sizeof(struct sockaddr_in),
894 .bind_conflict = inet_csk_bind_conflict,
896 .compat_setsockopt = compat_ip_setsockopt,
897 .compat_getsockopt = compat_ip_getsockopt,
901 static int dccp_v4_init_sock(struct sock *sk)
903 static __u8 dccp_v4_ctl_sock_initialized;
904 int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized);
907 if (unlikely(!dccp_v4_ctl_sock_initialized))
908 dccp_v4_ctl_sock_initialized = 1;
909 inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops;
915 static struct timewait_sock_ops dccp_timewait_sock_ops = {
916 .twsk_obj_size = sizeof(struct inet_timewait_sock),
919 static struct proto dccp_v4_prot = {
921 .owner = THIS_MODULE,
923 .connect = dccp_v4_connect,
924 .disconnect = dccp_disconnect,
926 .init = dccp_v4_init_sock,
927 .setsockopt = dccp_setsockopt,
928 .getsockopt = dccp_getsockopt,
929 .sendmsg = dccp_sendmsg,
930 .recvmsg = dccp_recvmsg,
931 .backlog_rcv = dccp_v4_do_rcv,
933 .unhash = inet_unhash,
934 .accept = inet_csk_accept,
935 .get_port = inet_csk_get_port,
936 .shutdown = dccp_shutdown,
937 .destroy = dccp_destroy_sock,
938 .orphan_count = &dccp_orphan_count,
939 .max_header = MAX_DCCP_HEADER,
940 .obj_size = sizeof(struct dccp_sock),
941 .slab_flags = SLAB_DESTROY_BY_RCU,
942 .rsk_prot = &dccp_request_sock_ops,
943 .twsk_prot = &dccp_timewait_sock_ops,
944 .h.hashinfo = &dccp_hashinfo,
946 .compat_setsockopt = compat_dccp_setsockopt,
947 .compat_getsockopt = compat_dccp_getsockopt,
951 static struct net_protocol dccp_v4_protocol = {
952 .handler = dccp_v4_rcv,
953 .err_handler = dccp_v4_err,
958 static const struct proto_ops inet_dccp_ops = {
960 .owner = THIS_MODULE,
961 .release = inet_release,
963 .connect = inet_stream_connect,
964 .socketpair = sock_no_socketpair,
965 .accept = inet_accept,
966 .getname = inet_getname,
967 /* FIXME: work on tcp_poll to rename it to inet_csk_poll */
970 /* FIXME: work on inet_listen to rename it to sock_common_listen */
971 .listen = inet_dccp_listen,
972 .shutdown = inet_shutdown,
973 .setsockopt = sock_common_setsockopt,
974 .getsockopt = sock_common_getsockopt,
975 .sendmsg = inet_sendmsg,
976 .recvmsg = sock_common_recvmsg,
977 .mmap = sock_no_mmap,
978 .sendpage = sock_no_sendpage,
980 .compat_setsockopt = compat_sock_common_setsockopt,
981 .compat_getsockopt = compat_sock_common_getsockopt,
985 static struct inet_protosw dccp_v4_protosw = {
987 .protocol = IPPROTO_DCCP,
988 .prot = &dccp_v4_prot,
989 .ops = &inet_dccp_ops,
992 .flags = INET_PROTOSW_ICSK,
995 static int dccp_v4_init_net(struct net *net)
999 err = inet_ctl_sock_create(&net->dccp.v4_ctl_sk, PF_INET,
1000 SOCK_DCCP, IPPROTO_DCCP, net);
1004 static void dccp_v4_exit_net(struct net *net)
1006 inet_ctl_sock_destroy(net->dccp.v4_ctl_sk);
1009 static struct pernet_operations dccp_v4_ops = {
1010 .init = dccp_v4_init_net,
1011 .exit = dccp_v4_exit_net,
1014 static int __init dccp_v4_init(void)
1016 int err = proto_register(&dccp_v4_prot, 1);
1021 err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1023 goto out_proto_unregister;
1025 inet_register_protosw(&dccp_v4_protosw);
1027 err = register_pernet_subsys(&dccp_v4_ops);
1029 goto out_destroy_ctl_sock;
1032 out_destroy_ctl_sock:
1033 inet_unregister_protosw(&dccp_v4_protosw);
1034 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1035 out_proto_unregister:
1036 proto_unregister(&dccp_v4_prot);
1040 static void __exit dccp_v4_exit(void)
1042 unregister_pernet_subsys(&dccp_v4_ops);
1043 inet_unregister_protosw(&dccp_v4_protosw);
1044 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1045 proto_unregister(&dccp_v4_prot);
1048 module_init(dccp_v4_init);
1049 module_exit(dccp_v4_exit);
1052 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1053 * values directly, Also cover the case where the protocol is not specified,
1054 * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
1056 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 33, 6);
1057 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 0, 6);
1058 MODULE_LICENSE("GPL");
1059 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1060 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");