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->inet_saddr,
66 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
68 inet->inet_sport, usin->sin_port, sk, 1);
72 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
77 if (inet->opt == NULL || !inet->opt->srr)
80 if (inet->inet_saddr == 0)
81 inet->inet_saddr = rt->rt_src;
82 inet->inet_rcv_saddr = inet->inet_saddr;
84 inet->inet_dport = usin->sin_port;
85 inet->inet_daddr = daddr;
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->inet_sport,
102 inet->inet_dport, sk);
106 /* OK, now commit destination to socket. */
107 sk_setup_caps(sk, &rt->u.dst);
109 dp->dccps_iss = secure_dccp_sequence_number(inet->inet_saddr,
113 inet->inet_id = dp->dccps_iss ^ jiffies;
115 err = dccp_connect(sk);
123 * This unhashes the socket and releases the local port, if necessary.
125 dccp_set_state(sk, DCCP_CLOSED);
127 sk->sk_route_caps = 0;
128 inet->inet_dport = 0;
132 EXPORT_SYMBOL_GPL(dccp_v4_connect);
135 * This routine does path mtu discovery as defined in RFC1191.
137 static inline void dccp_do_pmtu_discovery(struct sock *sk,
138 const struct iphdr *iph,
141 struct dst_entry *dst;
142 const struct inet_sock *inet = inet_sk(sk);
143 const struct dccp_sock *dp = dccp_sk(sk);
145 /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs
146 * send out by Linux are always < 576bytes so they should go through
149 if (sk->sk_state == DCCP_LISTEN)
152 /* We don't check in the destentry if pmtu discovery is forbidden
153 * on this route. We just assume that no packet_to_big packets
154 * are send back when pmtu discovery is not active.
155 * There is a small race when the user changes this flag in the
156 * route, but I think that's acceptable.
158 if ((dst = __sk_dst_check(sk, 0)) == NULL)
161 dst->ops->update_pmtu(dst, mtu);
163 /* Something is about to be wrong... Remember soft error
164 * for the case, if this connection will not able to recover.
166 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
167 sk->sk_err_soft = EMSGSIZE;
171 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
172 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
173 dccp_sync_mss(sk, mtu);
176 * From RFC 4340, sec. 14.1:
178 * DCCP-Sync packets are the best choice for upward
179 * probing, since DCCP-Sync probes do not risk application
182 dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC);
183 } /* else let the usual retransmit timer handle it */
187 * This routine is called by the ICMP module when it gets some sort of error
188 * condition. If err < 0 then the socket should be closed and the error
189 * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code.
190 * After adjustment header points to the first 8 bytes of the tcp header. We
191 * need to find the appropriate port.
193 * The locking strategy used here is very "optimistic". When someone else
194 * accesses the socket the ICMP is just dropped and for some paths there is no
195 * check at all. A more general error queue to queue errors for later handling
196 * is probably better.
198 static void dccp_v4_err(struct sk_buff *skb, u32 info)
200 const struct iphdr *iph = (struct iphdr *)skb->data;
201 const u8 offset = iph->ihl << 2;
202 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset);
203 struct dccp_sock *dp;
204 struct inet_sock *inet;
205 const int type = icmp_hdr(skb)->type;
206 const int code = icmp_hdr(skb)->code;
210 struct net *net = dev_net(skb->dev);
212 if (skb->len < offset + sizeof(*dh) ||
213 skb->len < offset + __dccp_basic_hdr_len(dh)) {
214 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
218 sk = inet_lookup(net, &dccp_hashinfo,
219 iph->daddr, dh->dccph_dport,
220 iph->saddr, dh->dccph_sport, inet_iif(skb));
222 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
226 if (sk->sk_state == DCCP_TIME_WAIT) {
227 inet_twsk_put(inet_twsk(sk));
232 /* If too many ICMPs get dropped on busy
233 * servers this needs to be solved differently.
235 if (sock_owned_by_user(sk))
236 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
238 if (sk->sk_state == DCCP_CLOSED)
242 seq = dccp_hdr_seq(dh);
243 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
244 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
245 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
250 case ICMP_SOURCE_QUENCH:
251 /* Just silently ignore these. */
253 case ICMP_PARAMETERPROB:
256 case ICMP_DEST_UNREACH:
257 if (code > NR_ICMP_UNREACH)
260 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
261 if (!sock_owned_by_user(sk))
262 dccp_do_pmtu_discovery(sk, iph, info);
266 err = icmp_err_convert[code].errno;
268 case ICMP_TIME_EXCEEDED:
275 switch (sk->sk_state) {
276 struct request_sock *req , **prev;
278 if (sock_owned_by_user(sk))
280 req = inet_csk_search_req(sk, &prev, dh->dccph_dport,
281 iph->daddr, iph->saddr);
286 * ICMPs are not backlogged, hence we cannot get an established
291 if (seq != dccp_rsk(req)->dreq_iss) {
292 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
296 * Still in RESPOND, just remove it silently.
297 * There is no good way to pass the error to the newly
298 * created socket, and POSIX does not want network
299 * errors returned from accept().
301 inet_csk_reqsk_queue_drop(sk, req, prev);
304 case DCCP_REQUESTING:
306 if (!sock_owned_by_user(sk)) {
307 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
310 sk->sk_error_report(sk);
314 sk->sk_err_soft = err;
318 /* If we've already connected we will keep trying
319 * until we time out, or the user gives up.
321 * rfc1122 4.2.3.9 allows to consider as hard errors
322 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
323 * but it is obsoleted by pmtu discovery).
325 * Note, that in modern internet, where routing is unreliable
326 * and in each dark corner broken firewalls sit, sending random
327 * errors ordered by their masters even this two messages finally lose
328 * their original sense (even Linux sends invalid PORT_UNREACHs)
330 * Now we are in compliance with RFCs.
335 if (!sock_owned_by_user(sk) && inet->recverr) {
337 sk->sk_error_report(sk);
338 } else /* Only an error on timeout */
339 sk->sk_err_soft = err;
345 static inline __sum16 dccp_v4_csum_finish(struct sk_buff *skb,
346 __be32 src, __be32 dst)
348 return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum);
351 void dccp_v4_send_check(struct sock *sk, int unused, struct sk_buff *skb)
353 const struct inet_sock *inet = inet_sk(sk);
354 struct dccp_hdr *dh = dccp_hdr(skb);
356 dccp_csum_outgoing(skb);
357 dh->dccph_checksum = dccp_v4_csum_finish(skb,
362 EXPORT_SYMBOL_GPL(dccp_v4_send_check);
364 static inline u64 dccp_v4_init_sequence(const struct sk_buff *skb)
366 return secure_dccp_sequence_number(ip_hdr(skb)->daddr,
368 dccp_hdr(skb)->dccph_dport,
369 dccp_hdr(skb)->dccph_sport);
373 * The three way handshake has completed - we got a valid ACK or DATAACK -
374 * now create the new socket.
376 * This is the equivalent of TCP's tcp_v4_syn_recv_sock
378 struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
379 struct request_sock *req,
380 struct dst_entry *dst)
382 struct inet_request_sock *ireq;
383 struct inet_sock *newinet;
386 if (sk_acceptq_is_full(sk))
389 if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
392 newsk = dccp_create_openreq_child(sk, req, skb);
396 sk_setup_caps(newsk, dst);
398 newinet = inet_sk(newsk);
399 ireq = inet_rsk(req);
400 newinet->inet_daddr = ireq->rmt_addr;
401 newinet->inet_rcv_saddr = ireq->loc_addr;
402 newinet->inet_saddr = ireq->loc_addr;
403 newinet->opt = ireq->opt;
405 newinet->mc_index = inet_iif(skb);
406 newinet->mc_ttl = ip_hdr(skb)->ttl;
407 newinet->inet_id = jiffies;
409 dccp_sync_mss(newsk, dst_mtu(dst));
411 __inet_hash_nolisten(newsk);
412 __inet_inherit_port(sk, newsk);
417 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
419 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
424 EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock);
426 static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
428 const struct dccp_hdr *dh = dccp_hdr(skb);
429 const struct iphdr *iph = ip_hdr(skb);
431 struct request_sock **prev;
432 /* Find possible connection requests. */
433 struct request_sock *req = inet_csk_search_req(sk, &prev,
435 iph->saddr, iph->daddr);
437 return dccp_check_req(sk, skb, req, prev);
439 nsk = inet_lookup_established(sock_net(sk), &dccp_hashinfo,
440 iph->saddr, dh->dccph_sport,
441 iph->daddr, dh->dccph_dport,
444 if (nsk->sk_state != DCCP_TIME_WAIT) {
448 inet_twsk_put(inet_twsk(nsk));
455 static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk,
459 struct flowi fl = { .oif = skb_rtable(skb)->rt_iif,
461 { .daddr = ip_hdr(skb)->saddr,
462 .saddr = ip_hdr(skb)->daddr,
463 .tos = RT_CONN_FLAGS(sk) } },
464 .proto = sk->sk_protocol,
466 { .sport = dccp_hdr(skb)->dccph_dport,
467 .dport = dccp_hdr(skb)->dccph_sport }
471 security_skb_classify_flow(skb, &fl);
472 if (ip_route_output_flow(net, &rt, &fl, sk, 0)) {
473 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
480 static int dccp_v4_send_response(struct sock *sk, struct request_sock *req)
484 struct dst_entry *dst;
486 dst = inet_csk_route_req(sk, req);
490 skb = dccp_make_response(sk, dst, req);
492 const struct inet_request_sock *ireq = inet_rsk(req);
493 struct dccp_hdr *dh = dccp_hdr(skb);
495 dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr,
497 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
500 err = net_xmit_eval(err);
508 static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
511 const struct iphdr *rxiph;
513 struct dst_entry *dst;
514 struct net *net = dev_net(skb_dst(rxskb)->dev);
515 struct sock *ctl_sk = net->dccp.v4_ctl_sk;
517 /* Never send a reset in response to a reset. */
518 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
521 if (skb_rtable(rxskb)->rt_type != RTN_LOCAL)
524 dst = dccp_v4_route_skb(net, ctl_sk, rxskb);
528 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
532 rxiph = ip_hdr(rxskb);
533 dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
535 skb_dst_set(skb, dst_clone(dst));
537 bh_lock_sock(ctl_sk);
538 err = ip_build_and_send_pkt(skb, ctl_sk,
539 rxiph->daddr, rxiph->saddr, NULL);
540 bh_unlock_sock(ctl_sk);
542 if (net_xmit_eval(err) == 0) {
543 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
544 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
550 static void dccp_v4_reqsk_destructor(struct request_sock *req)
552 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
553 kfree(inet_rsk(req)->opt);
556 static struct request_sock_ops dccp_request_sock_ops __read_mostly = {
558 .obj_size = sizeof(struct dccp_request_sock),
559 .rtx_syn_ack = dccp_v4_send_response,
560 .send_ack = dccp_reqsk_send_ack,
561 .destructor = dccp_v4_reqsk_destructor,
562 .send_reset = dccp_v4_ctl_send_reset,
565 int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
567 struct inet_request_sock *ireq;
568 struct request_sock *req;
569 struct dccp_request_sock *dreq;
570 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
571 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
573 /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
574 if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
575 return 0; /* discard, don't send a reset here */
577 if (dccp_bad_service_code(sk, service)) {
578 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
582 * TW buckets are converted to open requests without
583 * limitations, they conserve resources and peer is
584 * evidently real one.
586 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
587 if (inet_csk_reqsk_queue_is_full(sk))
591 * Accept backlog is full. If we have already queued enough
592 * of warm entries in syn queue, drop request. It is better than
593 * clogging syn queue with openreqs with exponentially increasing
596 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
599 req = inet_reqsk_alloc(&dccp_request_sock_ops);
603 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
606 dreq = dccp_rsk(req);
607 if (dccp_parse_options(sk, dreq, skb))
610 if (security_inet_conn_request(sk, skb, req))
613 ireq = inet_rsk(req);
614 ireq->loc_addr = ip_hdr(skb)->daddr;
615 ireq->rmt_addr = ip_hdr(skb)->saddr;
618 * Step 3: Process LISTEN state
620 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
622 * In fact we defer setting S.GSR, S.SWL, S.SWH to
623 * dccp_create_openreq_child.
625 dreq->dreq_isr = dcb->dccpd_seq;
626 dreq->dreq_iss = dccp_v4_init_sequence(skb);
627 dreq->dreq_service = service;
629 if (dccp_v4_send_response(sk, req))
632 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
638 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
642 EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
644 int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
646 struct dccp_hdr *dh = dccp_hdr(skb);
648 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
649 if (dccp_rcv_established(sk, skb, dh, skb->len))
655 * Step 3: Process LISTEN state
656 * If P.type == Request or P contains a valid Init Cookie option,
657 * (* Must scan the packet's options to check for Init
658 * Cookies. Only Init Cookies are processed here,
659 * however; other options are processed in Step 8. This
660 * scan need only be performed if the endpoint uses Init
662 * (* Generate a new socket and switch to that socket *)
663 * Set S := new socket for this port pair
665 * Choose S.ISS (initial seqno) or set from Init Cookies
666 * Initialize S.GAR := S.ISS
667 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
668 * Continue with S.state == RESPOND
669 * (* A Response packet will be generated in Step 11 *)
671 * Generate Reset(No Connection) unless P.type == Reset
672 * Drop packet and return
674 * NOTE: the check for the packet types is done in
675 * dccp_rcv_state_process
677 if (sk->sk_state == DCCP_LISTEN) {
678 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
684 if (dccp_child_process(sk, nsk, skb))
690 if (dccp_rcv_state_process(sk, skb, dh, skb->len))
695 dccp_v4_ctl_send_reset(sk, skb);
701 EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
704 * dccp_invalid_packet - check for malformed packets
705 * Implements RFC 4340, 8.5: Step 1: Check header basics
706 * Packets that fail these checks are ignored and do not receive Resets.
708 int dccp_invalid_packet(struct sk_buff *skb)
710 const struct dccp_hdr *dh;
713 if (skb->pkt_type != PACKET_HOST)
716 /* If the packet is shorter than 12 bytes, drop packet and return */
717 if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
718 DCCP_WARN("pskb_may_pull failed\n");
724 /* If P.type is not understood, drop packet and return */
725 if (dh->dccph_type >= DCCP_PKT_INVALID) {
726 DCCP_WARN("invalid packet type\n");
731 * If P.Data Offset is too small for packet type, drop packet and return
733 if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
734 DCCP_WARN("P.Data Offset(%u) too small\n", dh->dccph_doff);
738 * If P.Data Offset is too too large for packet, drop packet and return
740 if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
741 DCCP_WARN("P.Data Offset(%u) too large\n", dh->dccph_doff);
746 * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
747 * has short sequence numbers), drop packet and return
749 if ((dh->dccph_type < DCCP_PKT_DATA ||
750 dh->dccph_type > DCCP_PKT_DATAACK) && dh->dccph_x == 0) {
751 DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n",
752 dccp_packet_name(dh->dccph_type));
757 * If P.CsCov is too large for the packet size, drop packet and return.
758 * This must come _before_ checksumming (not as RFC 4340 suggests).
760 cscov = dccp_csum_coverage(skb);
761 if (cscov > skb->len) {
762 DCCP_WARN("P.CsCov %u exceeds packet length %d\n",
763 dh->dccph_cscov, skb->len);
767 /* If header checksum is incorrect, drop packet and return.
768 * (This step is completed in the AF-dependent functions.) */
769 skb->csum = skb_checksum(skb, 0, cscov, 0);
774 EXPORT_SYMBOL_GPL(dccp_invalid_packet);
776 /* this is called when real data arrives */
777 static int dccp_v4_rcv(struct sk_buff *skb)
779 const struct dccp_hdr *dh;
780 const struct iphdr *iph;
784 /* Step 1: Check header basics */
786 if (dccp_invalid_packet(skb))
790 /* Step 1: If header checksum is incorrect, drop packet and return */
791 if (dccp_v4_csum_finish(skb, iph->saddr, iph->daddr)) {
792 DCCP_WARN("dropped packet with invalid checksum\n");
798 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
799 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
801 dccp_pr_debug("%8.8s src=%pI4@%-5d dst=%pI4@%-5d seq=%llu",
802 dccp_packet_name(dh->dccph_type),
803 &iph->saddr, ntohs(dh->dccph_sport),
804 &iph->daddr, ntohs(dh->dccph_dport),
805 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
807 if (dccp_packet_without_ack(skb)) {
808 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
809 dccp_pr_debug_cat("\n");
811 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
812 dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long)
813 DCCP_SKB_CB(skb)->dccpd_ack_seq);
817 * Look up flow ID in table and get corresponding socket */
818 sk = __inet_lookup_skb(&dccp_hashinfo, skb,
819 dh->dccph_sport, dh->dccph_dport);
825 dccp_pr_debug("failed to look up flow ID in table and "
826 "get corresponding socket\n");
832 * ... or S.state == TIMEWAIT,
833 * Generate Reset(No Connection) unless P.type == Reset
834 * Drop packet and return
836 if (sk->sk_state == DCCP_TIME_WAIT) {
837 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
838 inet_twsk_put(inet_twsk(sk));
843 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
844 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
845 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
847 min_cov = dccp_sk(sk)->dccps_pcrlen;
848 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
849 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
850 dh->dccph_cscov, min_cov);
851 /* FIXME: "Such packets SHOULD be reported using Data Dropped
852 * options (Section 11.7) with Drop Code 0, Protocol
854 goto discard_and_relse;
857 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
858 goto discard_and_relse;
861 return sk_receive_skb(sk, skb, 1);
864 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
869 * Generate Reset(No Connection) unless P.type == Reset
870 * Drop packet and return
872 if (dh->dccph_type != DCCP_PKT_RESET) {
873 DCCP_SKB_CB(skb)->dccpd_reset_code =
874 DCCP_RESET_CODE_NO_CONNECTION;
875 dccp_v4_ctl_send_reset(sk, skb);
887 static const struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
888 .queue_xmit = ip_queue_xmit,
889 .send_check = dccp_v4_send_check,
890 .rebuild_header = inet_sk_rebuild_header,
891 .conn_request = dccp_v4_conn_request,
892 .syn_recv_sock = dccp_v4_request_recv_sock,
893 .net_header_len = sizeof(struct iphdr),
894 .setsockopt = ip_setsockopt,
895 .getsockopt = ip_getsockopt,
896 .addr2sockaddr = inet_csk_addr2sockaddr,
897 .sockaddr_len = sizeof(struct sockaddr_in),
898 .bind_conflict = inet_csk_bind_conflict,
900 .compat_setsockopt = compat_ip_setsockopt,
901 .compat_getsockopt = compat_ip_getsockopt,
905 static int dccp_v4_init_sock(struct sock *sk)
907 static __u8 dccp_v4_ctl_sock_initialized;
908 int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized);
911 if (unlikely(!dccp_v4_ctl_sock_initialized))
912 dccp_v4_ctl_sock_initialized = 1;
913 inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops;
919 static struct timewait_sock_ops dccp_timewait_sock_ops = {
920 .twsk_obj_size = sizeof(struct inet_timewait_sock),
923 static struct proto dccp_v4_prot = {
925 .owner = THIS_MODULE,
927 .connect = dccp_v4_connect,
928 .disconnect = dccp_disconnect,
930 .init = dccp_v4_init_sock,
931 .setsockopt = dccp_setsockopt,
932 .getsockopt = dccp_getsockopt,
933 .sendmsg = dccp_sendmsg,
934 .recvmsg = dccp_recvmsg,
935 .backlog_rcv = dccp_v4_do_rcv,
937 .unhash = inet_unhash,
938 .accept = inet_csk_accept,
939 .get_port = inet_csk_get_port,
940 .shutdown = dccp_shutdown,
941 .destroy = dccp_destroy_sock,
942 .orphan_count = &dccp_orphan_count,
943 .max_header = MAX_DCCP_HEADER,
944 .obj_size = sizeof(struct dccp_sock),
945 .slab_flags = SLAB_DESTROY_BY_RCU,
946 .rsk_prot = &dccp_request_sock_ops,
947 .twsk_prot = &dccp_timewait_sock_ops,
948 .h.hashinfo = &dccp_hashinfo,
950 .compat_setsockopt = compat_dccp_setsockopt,
951 .compat_getsockopt = compat_dccp_getsockopt,
955 static const struct net_protocol dccp_v4_protocol = {
956 .handler = dccp_v4_rcv,
957 .err_handler = dccp_v4_err,
962 static const struct proto_ops inet_dccp_ops = {
964 .owner = THIS_MODULE,
965 .release = inet_release,
967 .connect = inet_stream_connect,
968 .socketpair = sock_no_socketpair,
969 .accept = inet_accept,
970 .getname = inet_getname,
971 /* FIXME: work on tcp_poll to rename it to inet_csk_poll */
974 /* FIXME: work on inet_listen to rename it to sock_common_listen */
975 .listen = inet_dccp_listen,
976 .shutdown = inet_shutdown,
977 .setsockopt = sock_common_setsockopt,
978 .getsockopt = sock_common_getsockopt,
979 .sendmsg = inet_sendmsg,
980 .recvmsg = sock_common_recvmsg,
981 .mmap = sock_no_mmap,
982 .sendpage = sock_no_sendpage,
984 .compat_setsockopt = compat_sock_common_setsockopt,
985 .compat_getsockopt = compat_sock_common_getsockopt,
989 static struct inet_protosw dccp_v4_protosw = {
991 .protocol = IPPROTO_DCCP,
992 .prot = &dccp_v4_prot,
993 .ops = &inet_dccp_ops,
995 .flags = INET_PROTOSW_ICSK,
998 static int dccp_v4_init_net(struct net *net)
1002 err = inet_ctl_sock_create(&net->dccp.v4_ctl_sk, PF_INET,
1003 SOCK_DCCP, IPPROTO_DCCP, net);
1007 static void dccp_v4_exit_net(struct net *net)
1009 inet_ctl_sock_destroy(net->dccp.v4_ctl_sk);
1012 static struct pernet_operations dccp_v4_ops = {
1013 .init = dccp_v4_init_net,
1014 .exit = dccp_v4_exit_net,
1017 static int __init dccp_v4_init(void)
1019 int err = proto_register(&dccp_v4_prot, 1);
1024 err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1026 goto out_proto_unregister;
1028 inet_register_protosw(&dccp_v4_protosw);
1030 err = register_pernet_subsys(&dccp_v4_ops);
1032 goto out_destroy_ctl_sock;
1035 out_destroy_ctl_sock:
1036 inet_unregister_protosw(&dccp_v4_protosw);
1037 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1038 out_proto_unregister:
1039 proto_unregister(&dccp_v4_prot);
1043 static void __exit dccp_v4_exit(void)
1045 unregister_pernet_subsys(&dccp_v4_ops);
1046 inet_unregister_protosw(&dccp_v4_protosw);
1047 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1048 proto_unregister(&dccp_v4_prot);
1051 module_init(dccp_v4_init);
1052 module_exit(dccp_v4_exit);
1055 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1056 * values directly, Also cover the case where the protocol is not specified,
1057 * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
1059 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 33, 6);
1060 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 0, 6);
1061 MODULE_LICENSE("GPL");
1062 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1063 MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");